| 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" |
| 22 | #include "elf-vxworks.h" |
| 23 | #include "objalloc.h" |
| 24 | #include "elf/i386.h" |
| 25 | #include "elf/x86-64.h" |
| 26 | |
| 27 | /* The name of the dynamic interpreter. This is put in the .interp |
| 28 | section. */ |
| 29 | |
| 30 | #define ELF32_DYNAMIC_INTERPRETER "/usr/lib/libc.so.1" |
| 31 | #define ELF64_DYNAMIC_INTERPRETER "/lib/ld64.so.1" |
| 32 | #define ELFX32_DYNAMIC_INTERPRETER "/lib/ldx32.so.1" |
| 33 | |
| 34 | bfd_boolean |
| 35 | _bfd_x86_elf_mkobject (bfd *abfd) |
| 36 | { |
| 37 | return bfd_elf_allocate_object (abfd, |
| 38 | sizeof (struct elf_x86_obj_tdata), |
| 39 | get_elf_backend_data (abfd)->target_id); |
| 40 | } |
| 41 | |
| 42 | /* _TLS_MODULE_BASE_ needs to be treated especially when linking |
| 43 | executables. Rather than setting it to the beginning of the TLS |
| 44 | section, we have to set it to the end. This function may be called |
| 45 | multiple times, it is idempotent. */ |
| 46 | |
| 47 | void |
| 48 | _bfd_x86_elf_set_tls_module_base (struct bfd_link_info *info) |
| 49 | { |
| 50 | struct elf_x86_link_hash_table *htab; |
| 51 | struct bfd_link_hash_entry *base; |
| 52 | const struct elf_backend_data *bed; |
| 53 | |
| 54 | if (!bfd_link_executable (info)) |
| 55 | return; |
| 56 | |
| 57 | bed = get_elf_backend_data (info->output_bfd); |
| 58 | htab = elf_x86_hash_table (info, bed->target_id); |
| 59 | if (htab == NULL) |
| 60 | return; |
| 61 | |
| 62 | base = htab->tls_module_base; |
| 63 | if (base == NULL) |
| 64 | return; |
| 65 | |
| 66 | base->u.def.value = htab->elf.tls_size; |
| 67 | } |
| 68 | |
| 69 | /* Return the base VMA address which should be subtracted from real addresses |
| 70 | when resolving @dtpoff relocation. |
| 71 | This is PT_TLS segment p_vaddr. */ |
| 72 | |
| 73 | bfd_vma |
| 74 | _bfd_x86_elf_dtpoff_base (struct bfd_link_info *info) |
| 75 | { |
| 76 | /* If tls_sec is NULL, we should have signalled an error already. */ |
| 77 | if (elf_hash_table (info)->tls_sec == NULL) |
| 78 | return 0; |
| 79 | return elf_hash_table (info)->tls_sec->vma; |
| 80 | } |
| 81 | |
| 82 | /* 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 | |
| 239 | static void |
| 240 | elf_x86_link_hash_table_free (bfd *obfd) |
| 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 | |
| 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; |
| 280 | ret->sizeof_reloc = sizeof (Elf64_External_Rela); |
| 281 | ret->pointer_r_type = R_X86_64_64; |
| 282 | ret->dynamic_interpreter = ELF64_DYNAMIC_INTERPRETER; |
| 283 | ret->dynamic_interpreter_size = sizeof ELF64_DYNAMIC_INTERPRETER; |
| 284 | ret->tls_get_addr = "__tls_get_addr"; |
| 285 | } |
| 286 | else |
| 287 | #endif |
| 288 | { |
| 289 | ret->r_info = elf32_r_info; |
| 290 | ret->r_sym = elf32_r_sym; |
| 291 | if (bed->target_id == X86_64_ELF_DATA) |
| 292 | { |
| 293 | ret->sizeof_reloc = sizeof (Elf32_External_Rela); |
| 294 | ret->pointer_r_type = R_X86_64_32; |
| 295 | ret->dynamic_interpreter = ELFX32_DYNAMIC_INTERPRETER; |
| 296 | ret->dynamic_interpreter_size |
| 297 | = sizeof ELFX32_DYNAMIC_INTERPRETER; |
| 298 | ret->tls_get_addr = "__tls_get_addr"; |
| 299 | } |
| 300 | else |
| 301 | { |
| 302 | ret->sizeof_reloc = sizeof (Elf32_External_Rel); |
| 303 | ret->pointer_r_type = R_386_32; |
| 304 | ret->dynamic_interpreter = ELF32_DYNAMIC_INTERPRETER; |
| 305 | ret->dynamic_interpreter_size |
| 306 | = sizeof ELF32_DYNAMIC_INTERPRETER; |
| 307 | ret->tls_get_addr = "___tls_get_addr"; |
| 308 | } |
| 309 | } |
| 310 | |
| 311 | ret->loc_hash_table = htab_try_create (1024, |
| 312 | _bfd_x86_elf_local_htab_hash, |
| 313 | _bfd_x86_elf_local_htab_eq, |
| 314 | NULL); |
| 315 | ret->loc_hash_memory = objalloc_create (); |
| 316 | if (!ret->loc_hash_table || !ret->loc_hash_memory) |
| 317 | { |
| 318 | elf_x86_link_hash_table_free (abfd); |
| 319 | return NULL; |
| 320 | } |
| 321 | ret->elf.root.hash_table_free = elf_x86_link_hash_table_free; |
| 322 | |
| 323 | return &ret->elf.root; |
| 324 | } |
| 325 | |
| 326 | /* Sort relocs into address order. */ |
| 327 | |
| 328 | int |
| 329 | _bfd_x86_elf_compare_relocs (const void *ap, const void *bp) |
| 330 | { |
| 331 | const arelent *a = * (const arelent **) ap; |
| 332 | const arelent *b = * (const arelent **) bp; |
| 333 | |
| 334 | if (a->address > b->address) |
| 335 | return 1; |
| 336 | else if (a->address < b->address) |
| 337 | return -1; |
| 338 | else |
| 339 | return 0; |
| 340 | } |
| 341 | |
| 342 | bfd_boolean |
| 343 | _bfd_x86_elf_link_check_relocs (bfd *abfd, struct bfd_link_info *info) |
| 344 | { |
| 345 | if (!bfd_link_relocatable (info)) |
| 346 | { |
| 347 | /* Check for __tls_get_addr reference. */ |
| 348 | struct elf_x86_link_hash_table *htab; |
| 349 | const struct elf_backend_data *bed = get_elf_backend_data (abfd); |
| 350 | htab = elf_x86_hash_table (info, bed->target_id); |
| 351 | if (htab) |
| 352 | { |
| 353 | struct elf_link_hash_entry *h |
| 354 | = elf_link_hash_lookup (elf_hash_table (info), |
| 355 | htab->tls_get_addr, |
| 356 | FALSE, FALSE, FALSE); |
| 357 | if (h != NULL) |
| 358 | ((struct elf_x86_link_hash_entry *) h)->tls_get_addr = 1; |
| 359 | } |
| 360 | } |
| 361 | |
| 362 | /* Invoke the regular ELF backend linker to do all the work. */ |
| 363 | return _bfd_elf_link_check_relocs (abfd, info); |
| 364 | } |
| 365 | |
| 366 | bfd_boolean |
| 367 | _bfd_x86_elf_always_size_sections (bfd *output_bfd, |
| 368 | struct bfd_link_info *info) |
| 369 | { |
| 370 | asection *tls_sec = elf_hash_table (info)->tls_sec; |
| 371 | |
| 372 | if (tls_sec) |
| 373 | { |
| 374 | struct elf_link_hash_entry *tlsbase; |
| 375 | |
| 376 | tlsbase = elf_link_hash_lookup (elf_hash_table (info), |
| 377 | "_TLS_MODULE_BASE_", |
| 378 | FALSE, FALSE, FALSE); |
| 379 | |
| 380 | if (tlsbase && tlsbase->type == STT_TLS) |
| 381 | { |
| 382 | struct elf_x86_link_hash_table *htab; |
| 383 | struct bfd_link_hash_entry *bh = NULL; |
| 384 | const struct elf_backend_data *bed |
| 385 | = get_elf_backend_data (output_bfd); |
| 386 | |
| 387 | htab = elf_x86_hash_table (info, bed->target_id); |
| 388 | if (htab == NULL) |
| 389 | return FALSE; |
| 390 | |
| 391 | if (!(_bfd_generic_link_add_one_symbol |
| 392 | (info, output_bfd, "_TLS_MODULE_BASE_", BSF_LOCAL, |
| 393 | tls_sec, 0, NULL, FALSE, |
| 394 | bed->collect, &bh))) |
| 395 | return FALSE; |
| 396 | |
| 397 | htab->tls_module_base = bh; |
| 398 | |
| 399 | tlsbase = (struct elf_link_hash_entry *)bh; |
| 400 | tlsbase->def_regular = 1; |
| 401 | tlsbase->other = STV_HIDDEN; |
| 402 | tlsbase->root.linker_def = 1; |
| 403 | (*bed->elf_backend_hide_symbol) (info, tlsbase, TRUE); |
| 404 | } |
| 405 | } |
| 406 | |
| 407 | return TRUE; |
| 408 | } |
| 409 | |
| 410 | void |
| 411 | _bfd_x86_elf_merge_symbol_attribute (struct elf_link_hash_entry *h, |
| 412 | const Elf_Internal_Sym *isym, |
| 413 | bfd_boolean definition, |
| 414 | bfd_boolean dynamic ATTRIBUTE_UNUSED) |
| 415 | { |
| 416 | if (definition) |
| 417 | { |
| 418 | struct elf_x86_link_hash_entry *eh |
| 419 | = (struct elf_x86_link_hash_entry *) h; |
| 420 | eh->def_protected = (ELF_ST_VISIBILITY (isym->st_other) |
| 421 | == STV_PROTECTED); |
| 422 | } |
| 423 | } |
| 424 | |
| 425 | /* Copy the extra info we tack onto an elf_link_hash_entry. */ |
| 426 | |
| 427 | void |
| 428 | _bfd_x86_elf_copy_indirect_symbol (struct bfd_link_info *info, |
| 429 | struct elf_link_hash_entry *dir, |
| 430 | struct elf_link_hash_entry *ind) |
| 431 | { |
| 432 | struct elf_x86_link_hash_entry *edir, *eind; |
| 433 | |
| 434 | edir = (struct elf_x86_link_hash_entry *) dir; |
| 435 | eind = (struct elf_x86_link_hash_entry *) ind; |
| 436 | |
| 437 | if (eind->dyn_relocs != NULL) |
| 438 | { |
| 439 | if (edir->dyn_relocs != NULL) |
| 440 | { |
| 441 | struct elf_dyn_relocs **pp; |
| 442 | struct elf_dyn_relocs *p; |
| 443 | |
| 444 | /* Add reloc counts against the indirect sym to the direct sym |
| 445 | list. Merge any entries against the same section. */ |
| 446 | for (pp = &eind->dyn_relocs; (p = *pp) != NULL; ) |
| 447 | { |
| 448 | struct elf_dyn_relocs *q; |
| 449 | |
| 450 | for (q = edir->dyn_relocs; q != NULL; q = q->next) |
| 451 | if (q->sec == p->sec) |
| 452 | { |
| 453 | q->pc_count += p->pc_count; |
| 454 | q->count += p->count; |
| 455 | *pp = p->next; |
| 456 | break; |
| 457 | } |
| 458 | if (q == NULL) |
| 459 | pp = &p->next; |
| 460 | } |
| 461 | *pp = edir->dyn_relocs; |
| 462 | } |
| 463 | |
| 464 | edir->dyn_relocs = eind->dyn_relocs; |
| 465 | eind->dyn_relocs = NULL; |
| 466 | } |
| 467 | |
| 468 | if (ind->root.type == bfd_link_hash_indirect |
| 469 | && dir->got.refcount <= 0) |
| 470 | { |
| 471 | edir->tls_type = eind->tls_type; |
| 472 | eind->tls_type = GOT_UNKNOWN; |
| 473 | } |
| 474 | |
| 475 | /* Copy gotoff_ref so that elf_i386_adjust_dynamic_symbol will |
| 476 | generate a R_386_COPY reloc. */ |
| 477 | edir->gotoff_ref |= eind->gotoff_ref; |
| 478 | |
| 479 | edir->has_got_reloc |= eind->has_got_reloc; |
| 480 | edir->has_non_got_reloc |= eind->has_non_got_reloc; |
| 481 | |
| 482 | if (ELIMINATE_COPY_RELOCS |
| 483 | && ind->root.type != bfd_link_hash_indirect |
| 484 | && dir->dynamic_adjusted) |
| 485 | { |
| 486 | /* If called to transfer flags for a weakdef during processing |
| 487 | of elf_adjust_dynamic_symbol, don't copy non_got_ref. |
| 488 | We clear it ourselves for ELIMINATE_COPY_RELOCS. */ |
| 489 | if (dir->versioned != versioned_hidden) |
| 490 | dir->ref_dynamic |= ind->ref_dynamic; |
| 491 | dir->ref_regular |= ind->ref_regular; |
| 492 | dir->ref_regular_nonweak |= ind->ref_regular_nonweak; |
| 493 | dir->needs_plt |= ind->needs_plt; |
| 494 | dir->pointer_equality_needed |= ind->pointer_equality_needed; |
| 495 | } |
| 496 | else |
| 497 | { |
| 498 | if (eind->func_pointer_refcount > 0) |
| 499 | { |
| 500 | edir->func_pointer_refcount += eind->func_pointer_refcount; |
| 501 | eind->func_pointer_refcount = 0; |
| 502 | } |
| 503 | |
| 504 | _bfd_elf_link_hash_copy_indirect (info, dir, ind); |
| 505 | } |
| 506 | } |
| 507 | |
| 508 | /* Remove undefined weak symbol from the dynamic symbol table if it |
| 509 | is resolved to 0. */ |
| 510 | |
| 511 | bfd_boolean |
| 512 | _bfd_x86_elf_fixup_symbol (struct bfd_link_info *info, |
| 513 | struct elf_link_hash_entry *h) |
| 514 | { |
| 515 | if (h->dynindx != -1) |
| 516 | { |
| 517 | const struct elf_backend_data *bed |
| 518 | = get_elf_backend_data (info->output_bfd); |
| 519 | if (UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, |
| 520 | bed->target_id, |
| 521 | elf_x86_hash_entry (h)->has_got_reloc, |
| 522 | elf_x86_hash_entry (h))) |
| 523 | { |
| 524 | h->dynindx = -1; |
| 525 | _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr, |
| 526 | h->dynstr_index); |
| 527 | } |
| 528 | } |
| 529 | return TRUE; |
| 530 | } |
| 531 | |
| 532 | /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */ |
| 533 | |
| 534 | bfd_boolean |
| 535 | _bfd_x86_elf_hash_symbol (struct elf_link_hash_entry *h) |
| 536 | { |
| 537 | if (h->plt.offset != (bfd_vma) -1 |
| 538 | && !h->def_regular |
| 539 | && !h->pointer_equality_needed) |
| 540 | return FALSE; |
| 541 | |
| 542 | return _bfd_elf_hash_symbol (h); |
| 543 | } |
| 544 | |
| 545 | /* Adjust a symbol defined by a dynamic object and referenced by a |
| 546 | regular object. The current definition is in some section of the |
| 547 | dynamic object, but we're not including those sections. We have to |
| 548 | change the definition to something the rest of the link can |
| 549 | understand. */ |
| 550 | |
| 551 | bfd_boolean |
| 552 | _bfd_x86_elf_adjust_dynamic_symbol (struct bfd_link_info *info, |
| 553 | struct elf_link_hash_entry *h) |
| 554 | { |
| 555 | struct elf_x86_link_hash_table *htab; |
| 556 | asection *s, *srel; |
| 557 | struct elf_x86_link_hash_entry *eh; |
| 558 | struct elf_dyn_relocs *p; |
| 559 | const struct elf_backend_data *bed |
| 560 | = get_elf_backend_data (info->output_bfd); |
| 561 | |
| 562 | /* STT_GNU_IFUNC symbol must go through PLT. */ |
| 563 | if (h->type == STT_GNU_IFUNC) |
| 564 | { |
| 565 | /* All local STT_GNU_IFUNC references must be treate as local |
| 566 | calls via local PLT. */ |
| 567 | if (h->ref_regular |
| 568 | && SYMBOL_CALLS_LOCAL (info, h)) |
| 569 | { |
| 570 | bfd_size_type pc_count = 0, count = 0; |
| 571 | struct elf_dyn_relocs **pp; |
| 572 | |
| 573 | eh = (struct elf_x86_link_hash_entry *) h; |
| 574 | for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) |
| 575 | { |
| 576 | pc_count += p->pc_count; |
| 577 | p->count -= p->pc_count; |
| 578 | p->pc_count = 0; |
| 579 | count += p->count; |
| 580 | if (p->count == 0) |
| 581 | *pp = p->next; |
| 582 | else |
| 583 | pp = &p->next; |
| 584 | } |
| 585 | |
| 586 | if (pc_count || count) |
| 587 | { |
| 588 | h->non_got_ref = 1; |
| 589 | if (pc_count) |
| 590 | { |
| 591 | /* Increment PLT reference count only for PC-relative |
| 592 | references. */ |
| 593 | h->needs_plt = 1; |
| 594 | if (h->plt.refcount <= 0) |
| 595 | h->plt.refcount = 1; |
| 596 | else |
| 597 | h->plt.refcount += 1; |
| 598 | } |
| 599 | } |
| 600 | } |
| 601 | |
| 602 | if (h->plt.refcount <= 0) |
| 603 | { |
| 604 | h->plt.offset = (bfd_vma) -1; |
| 605 | h->needs_plt = 0; |
| 606 | } |
| 607 | return TRUE; |
| 608 | } |
| 609 | |
| 610 | /* If this is a function, put it in the procedure linkage table. We |
| 611 | will fill in the contents of the procedure linkage table later, |
| 612 | when we know the address of the .got section. */ |
| 613 | if (h->type == STT_FUNC |
| 614 | || h->needs_plt) |
| 615 | { |
| 616 | if (h->plt.refcount <= 0 |
| 617 | || SYMBOL_CALLS_LOCAL (info, h) |
| 618 | || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT |
| 619 | && h->root.type == bfd_link_hash_undefweak)) |
| 620 | { |
| 621 | /* This case can occur if we saw a PLT32 reloc in an input |
| 622 | file, but the symbol was never referred to by a dynamic |
| 623 | object, or if all references were garbage collected. In |
| 624 | such a case, we don't actually need to build a procedure |
| 625 | linkage table, and we can just do a PC32 reloc instead. */ |
| 626 | h->plt.offset = (bfd_vma) -1; |
| 627 | h->needs_plt = 0; |
| 628 | } |
| 629 | |
| 630 | return TRUE; |
| 631 | } |
| 632 | else |
| 633 | /* It's possible that we incorrectly decided a .plt reloc was needed |
| 634 | * for an R_386_PC32/R_X86_64_PC32 reloc to a non-function sym in |
| 635 | check_relocs. We can't decide accurately between function and |
| 636 | non-function syms in check-relocs; Objects loaded later in |
| 637 | the link may change h->type. So fix it now. */ |
| 638 | h->plt.offset = (bfd_vma) -1; |
| 639 | |
| 640 | eh = (struct elf_x86_link_hash_entry *) h; |
| 641 | |
| 642 | /* If this is a weak symbol, and there is a real definition, the |
| 643 | processor independent code will have arranged for us to see the |
| 644 | real definition first, and we can just use the same value. */ |
| 645 | if (h->u.weakdef != NULL) |
| 646 | { |
| 647 | BFD_ASSERT (h->u.weakdef->root.type == bfd_link_hash_defined |
| 648 | || h->u.weakdef->root.type == bfd_link_hash_defweak); |
| 649 | h->root.u.def.section = h->u.weakdef->root.u.def.section; |
| 650 | h->root.u.def.value = h->u.weakdef->root.u.def.value; |
| 651 | if (ELIMINATE_COPY_RELOCS |
| 652 | || info->nocopyreloc |
| 653 | || SYMBOL_NO_COPYRELOC (info, eh)) |
| 654 | { |
| 655 | /* NB: needs_copy is always 0 for i386. */ |
| 656 | h->non_got_ref = h->u.weakdef->non_got_ref; |
| 657 | eh->needs_copy = h->u.weakdef->needs_copy; |
| 658 | } |
| 659 | return TRUE; |
| 660 | } |
| 661 | |
| 662 | /* This is a reference to a symbol defined by a dynamic object which |
| 663 | is not a function. */ |
| 664 | |
| 665 | /* If we are creating a shared library, we must presume that the |
| 666 | only references to the symbol are via the global offset table. |
| 667 | For such cases we need not do anything here; the relocations will |
| 668 | be handled correctly by relocate_section. */ |
| 669 | if (!bfd_link_executable (info)) |
| 670 | return TRUE; |
| 671 | |
| 672 | /* If there are no references to this symbol that do not use the |
| 673 | GOT nor R_386_GOTOFF relocation, we don't need to generate a copy |
| 674 | reloc. NB: gotoff_ref is always 0 for x86-64. */ |
| 675 | if (!h->non_got_ref && !eh->gotoff_ref) |
| 676 | return TRUE; |
| 677 | |
| 678 | /* If -z nocopyreloc was given, we won't generate them either. */ |
| 679 | if (info->nocopyreloc || SYMBOL_NO_COPYRELOC (info, eh)) |
| 680 | { |
| 681 | h->non_got_ref = 0; |
| 682 | return TRUE; |
| 683 | } |
| 684 | |
| 685 | htab = elf_x86_hash_table (info, bed->target_id); |
| 686 | if (htab == NULL) |
| 687 | return FALSE; |
| 688 | |
| 689 | /* If there aren't any dynamic relocs in read-only sections nor |
| 690 | R_386_GOTOFF relocation, then we can keep the dynamic relocs and |
| 691 | avoid the copy reloc. This doesn't work on VxWorks, where we can |
| 692 | not have dynamic relocations (other than copy and jump slot |
| 693 | relocations) in an executable. */ |
| 694 | if (ELIMINATE_COPY_RELOCS |
| 695 | && (bed->target_id == X86_64_ELF_DATA |
| 696 | || (!eh->gotoff_ref |
| 697 | && !htab->is_vxworks))) |
| 698 | { |
| 699 | for (p = eh->dyn_relocs; p != NULL; p = p->next) |
| 700 | { |
| 701 | s = p->sec->output_section; |
| 702 | if (s != NULL && (s->flags & SEC_READONLY) != 0) |
| 703 | break; |
| 704 | } |
| 705 | |
| 706 | /* If we didn't find any dynamic relocs in read-only sections, |
| 707 | then we'll be keeping the dynamic relocs and avoiding the copy |
| 708 | reloc. */ |
| 709 | if (p == NULL) |
| 710 | { |
| 711 | h->non_got_ref = 0; |
| 712 | return TRUE; |
| 713 | } |
| 714 | } |
| 715 | |
| 716 | /* We must allocate the symbol in our .dynbss section, which will |
| 717 | become part of the .bss section of the executable. There will be |
| 718 | an entry for this symbol in the .dynsym section. The dynamic |
| 719 | object will contain position independent code, so all references |
| 720 | from the dynamic object to this symbol will go through the global |
| 721 | offset table. The dynamic linker will use the .dynsym entry to |
| 722 | determine the address it must put in the global offset table, so |
| 723 | both the dynamic object and the regular object will refer to the |
| 724 | same memory location for the variable. */ |
| 725 | |
| 726 | /* We must generate a R_386_COPY/R_X86_64_COPY reloc to tell the |
| 727 | dynamic linker to copy the initial value out of the dynamic object |
| 728 | and into the runtime process image. */ |
| 729 | if ((h->root.u.def.section->flags & SEC_READONLY) != 0) |
| 730 | { |
| 731 | s = htab->elf.sdynrelro; |
| 732 | srel = htab->elf.sreldynrelro; |
| 733 | } |
| 734 | else |
| 735 | { |
| 736 | s = htab->elf.sdynbss; |
| 737 | srel = htab->elf.srelbss; |
| 738 | } |
| 739 | if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0) |
| 740 | { |
| 741 | srel->size += htab->sizeof_reloc; |
| 742 | h->needs_copy = 1; |
| 743 | } |
| 744 | |
| 745 | return _bfd_elf_adjust_dynamic_copy (info, h, s); |
| 746 | } |
| 747 | |
| 748 | /* Return the section that should be marked against GC for a given |
| 749 | relocation. */ |
| 750 | |
| 751 | asection * |
| 752 | _bfd_x86_elf_gc_mark_hook (asection *sec, |
| 753 | struct bfd_link_info *info, |
| 754 | Elf_Internal_Rela *rel, |
| 755 | struct elf_link_hash_entry *h, |
| 756 | Elf_Internal_Sym *sym) |
| 757 | { |
| 758 | /* Compiler should optimize this out. */ |
| 759 | if (((unsigned int) R_X86_64_GNU_VTINHERIT |
| 760 | != (unsigned int) R_386_GNU_VTINHERIT) |
| 761 | || ((unsigned int) R_X86_64_GNU_VTENTRY |
| 762 | != (unsigned int) R_386_GNU_VTENTRY)) |
| 763 | abort (); |
| 764 | |
| 765 | if (h != NULL) |
| 766 | switch (ELF32_R_TYPE (rel->r_info)) |
| 767 | { |
| 768 | case R_X86_64_GNU_VTINHERIT: |
| 769 | case R_X86_64_GNU_VTENTRY: |
| 770 | return NULL; |
| 771 | } |
| 772 | |
| 773 | return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym); |
| 774 | } |
| 775 | |
| 776 | static bfd_vma |
| 777 | elf_i386_get_plt_got_vma (struct elf_x86_plt *plt_p ATTRIBUTE_UNUSED, |
| 778 | bfd_vma off, |
| 779 | bfd_vma offset ATTRIBUTE_UNUSED, |
| 780 | bfd_vma got_addr) |
| 781 | { |
| 782 | return got_addr + off; |
| 783 | } |
| 784 | |
| 785 | static bfd_vma |
| 786 | elf_x86_64_get_plt_got_vma (struct elf_x86_plt *plt_p, |
| 787 | bfd_vma off, |
| 788 | bfd_vma offset, |
| 789 | bfd_vma got_addr ATTRIBUTE_UNUSED) |
| 790 | { |
| 791 | return plt_p->sec->vma + offset + off + plt_p->plt_got_insn_size; |
| 792 | } |
| 793 | |
| 794 | static bfd_boolean |
| 795 | elf_i386_valid_plt_reloc_p (unsigned int type) |
| 796 | { |
| 797 | return (type == R_386_JUMP_SLOT |
| 798 | || type == R_386_GLOB_DAT |
| 799 | || type == R_386_IRELATIVE); |
| 800 | } |
| 801 | |
| 802 | static bfd_boolean |
| 803 | elf_x86_64_valid_plt_reloc_p (unsigned int type) |
| 804 | { |
| 805 | return (type == R_X86_64_JUMP_SLOT |
| 806 | || type == R_X86_64_GLOB_DAT |
| 807 | || type == R_X86_64_IRELATIVE); |
| 808 | } |
| 809 | |
| 810 | long |
| 811 | _bfd_x86_elf_get_synthetic_symtab (bfd *abfd, |
| 812 | long count, |
| 813 | long relsize, |
| 814 | bfd_vma got_addr, |
| 815 | struct elf_x86_plt plts[], |
| 816 | asymbol **dynsyms, |
| 817 | asymbol **ret) |
| 818 | { |
| 819 | long size, i, n, len; |
| 820 | int j; |
| 821 | unsigned int plt_got_offset, plt_entry_size; |
| 822 | asymbol *s; |
| 823 | bfd_byte *plt_contents; |
| 824 | long dynrelcount; |
| 825 | arelent **dynrelbuf, *p; |
| 826 | char *names; |
| 827 | const struct elf_backend_data *bed; |
| 828 | bfd_vma (*get_plt_got_vma) (struct elf_x86_plt *, bfd_vma, bfd_vma, |
| 829 | bfd_vma); |
| 830 | bfd_boolean (*valid_plt_reloc_p) (unsigned int); |
| 831 | |
| 832 | if (count == 0) |
| 833 | return -1; |
| 834 | |
| 835 | dynrelbuf = (arelent **) bfd_malloc (relsize); |
| 836 | if (dynrelbuf == NULL) |
| 837 | return -1; |
| 838 | |
| 839 | dynrelcount = bfd_canonicalize_dynamic_reloc (abfd, dynrelbuf, |
| 840 | dynsyms); |
| 841 | |
| 842 | /* Sort the relocs by address. */ |
| 843 | qsort (dynrelbuf, dynrelcount, sizeof (arelent *), |
| 844 | _bfd_x86_elf_compare_relocs); |
| 845 | |
| 846 | size = count * sizeof (asymbol); |
| 847 | |
| 848 | /* Allocate space for @plt suffixes. */ |
| 849 | n = 0; |
| 850 | for (i = 0; i < dynrelcount; i++) |
| 851 | { |
| 852 | p = dynrelbuf[i]; |
| 853 | size += strlen ((*p->sym_ptr_ptr)->name) + sizeof ("@plt"); |
| 854 | if (p->addend != 0) |
| 855 | size += sizeof ("+0x") - 1 + 8 + 8 * ABI_64_P (abfd); |
| 856 | } |
| 857 | |
| 858 | s = *ret = (asymbol *) bfd_zmalloc (size); |
| 859 | if (s == NULL) |
| 860 | goto bad_return; |
| 861 | |
| 862 | bed = get_elf_backend_data (abfd); |
| 863 | |
| 864 | if (bed->target_id == X86_64_ELF_DATA) |
| 865 | { |
| 866 | get_plt_got_vma = elf_x86_64_get_plt_got_vma; |
| 867 | valid_plt_reloc_p = elf_x86_64_valid_plt_reloc_p; |
| 868 | } |
| 869 | else |
| 870 | { |
| 871 | get_plt_got_vma = elf_i386_get_plt_got_vma; |
| 872 | valid_plt_reloc_p = elf_i386_valid_plt_reloc_p; |
| 873 | if (got_addr) |
| 874 | { |
| 875 | /* Check .got.plt and then .got to get the _GLOBAL_OFFSET_TABLE_ |
| 876 | address. */ |
| 877 | asection *sec = bfd_get_section_by_name (abfd, ".got.plt"); |
| 878 | if (sec != NULL) |
| 879 | got_addr = sec->vma; |
| 880 | else |
| 881 | { |
| 882 | sec = bfd_get_section_by_name (abfd, ".got"); |
| 883 | if (sec != NULL) |
| 884 | got_addr = sec->vma; |
| 885 | } |
| 886 | |
| 887 | if (got_addr == (bfd_vma) -1) |
| 888 | goto bad_return; |
| 889 | } |
| 890 | } |
| 891 | |
| 892 | /* Check for each PLT section. */ |
| 893 | names = (char *) (s + count); |
| 894 | size = 0; |
| 895 | n = 0; |
| 896 | for (j = 0; plts[j].name != NULL; j++) |
| 897 | if ((plt_contents = plts[j].contents) != NULL) |
| 898 | { |
| 899 | long k; |
| 900 | bfd_vma offset; |
| 901 | asection *plt; |
| 902 | struct elf_x86_plt *plt_p = &plts[j]; |
| 903 | |
| 904 | plt_got_offset = plt_p->plt_got_offset; |
| 905 | plt_entry_size = plt_p->plt_entry_size; |
| 906 | |
| 907 | plt = plt_p->sec; |
| 908 | |
| 909 | if ((plt_p->type & plt_lazy)) |
| 910 | { |
| 911 | /* Skip PLT0 in lazy PLT. */ |
| 912 | k = 1; |
| 913 | offset = plt_entry_size; |
| 914 | } |
| 915 | else |
| 916 | { |
| 917 | k = 0; |
| 918 | offset = 0; |
| 919 | } |
| 920 | |
| 921 | /* Check each PLT entry against dynamic relocations. */ |
| 922 | for (; k < plt_p->count; k++) |
| 923 | { |
| 924 | int off; |
| 925 | bfd_vma got_vma; |
| 926 | long min, max, mid; |
| 927 | |
| 928 | /* Get the GOT offset for i386 or the PC-relative offset |
| 929 | for x86-64, a signed 32-bit integer. */ |
| 930 | off = H_GET_32 (abfd, (plt_contents + offset |
| 931 | + plt_got_offset)); |
| 932 | got_vma = get_plt_got_vma (plt_p, off, offset, got_addr); |
| 933 | |
| 934 | /* Binary search. */ |
| 935 | p = dynrelbuf[0]; |
| 936 | min = 0; |
| 937 | max = dynrelcount; |
| 938 | while ((min + 1) < max) |
| 939 | { |
| 940 | arelent *r; |
| 941 | |
| 942 | mid = (min + max) / 2; |
| 943 | r = dynrelbuf[mid]; |
| 944 | if (got_vma > r->address) |
| 945 | min = mid; |
| 946 | else if (got_vma < r->address) |
| 947 | max = mid; |
| 948 | else |
| 949 | { |
| 950 | p = r; |
| 951 | break; |
| 952 | } |
| 953 | } |
| 954 | |
| 955 | /* Skip unknown relocation. PR 17512: file: bc9d6cf5. */ |
| 956 | if (got_vma == p->address |
| 957 | && p->howto != NULL |
| 958 | && valid_plt_reloc_p (p->howto->type)) |
| 959 | { |
| 960 | *s = **p->sym_ptr_ptr; |
| 961 | /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL |
| 962 | set. Since we are defining a symbol, ensure one |
| 963 | of them is set. */ |
| 964 | if ((s->flags & BSF_LOCAL) == 0) |
| 965 | s->flags |= BSF_GLOBAL; |
| 966 | s->flags |= BSF_SYNTHETIC; |
| 967 | /* This is no longer a section symbol. */ |
| 968 | s->flags &= ~BSF_SECTION_SYM; |
| 969 | s->section = plt; |
| 970 | s->the_bfd = plt->owner; |
| 971 | s->value = offset; |
| 972 | s->udata.p = NULL; |
| 973 | s->name = names; |
| 974 | len = strlen ((*p->sym_ptr_ptr)->name); |
| 975 | memcpy (names, (*p->sym_ptr_ptr)->name, len); |
| 976 | names += len; |
| 977 | if (p->addend != 0) |
| 978 | { |
| 979 | char buf[30], *a; |
| 980 | |
| 981 | memcpy (names, "+0x", sizeof ("+0x") - 1); |
| 982 | names += sizeof ("+0x") - 1; |
| 983 | bfd_sprintf_vma (abfd, buf, p->addend); |
| 984 | for (a = buf; *a == '0'; ++a) |
| 985 | ; |
| 986 | size = strlen (a); |
| 987 | memcpy (names, a, size); |
| 988 | names += size; |
| 989 | } |
| 990 | memcpy (names, "@plt", sizeof ("@plt")); |
| 991 | names += sizeof ("@plt"); |
| 992 | n++; |
| 993 | s++; |
| 994 | } |
| 995 | offset += plt_entry_size; |
| 996 | } |
| 997 | } |
| 998 | |
| 999 | /* PLT entries with R_386_TLS_DESC relocations are skipped. */ |
| 1000 | if (n == 0) |
| 1001 | { |
| 1002 | bad_return: |
| 1003 | count = -1; |
| 1004 | } |
| 1005 | else |
| 1006 | count = n; |
| 1007 | |
| 1008 | for (j = 0; plts[j].name != NULL; j++) |
| 1009 | if (plts[j].contents != NULL) |
| 1010 | free (plts[j].contents); |
| 1011 | |
| 1012 | free (dynrelbuf); |
| 1013 | |
| 1014 | return count; |
| 1015 | } |
| 1016 | |
| 1017 | /* Parse x86 GNU properties. */ |
| 1018 | |
| 1019 | enum elf_property_kind |
| 1020 | _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type, |
| 1021 | bfd_byte *ptr, unsigned int datasz) |
| 1022 | { |
| 1023 | elf_property *prop; |
| 1024 | |
| 1025 | switch (type) |
| 1026 | { |
| 1027 | case GNU_PROPERTY_X86_ISA_1_USED: |
| 1028 | case GNU_PROPERTY_X86_ISA_1_NEEDED: |
| 1029 | case GNU_PROPERTY_X86_FEATURE_1_AND: |
| 1030 | if (datasz != 4) |
| 1031 | { |
| 1032 | _bfd_error_handler |
| 1033 | ((type == GNU_PROPERTY_X86_ISA_1_USED |
| 1034 | ? _("error: %B: <corrupt x86 ISA used size: 0x%x>") |
| 1035 | : (type == GNU_PROPERTY_X86_ISA_1_NEEDED |
| 1036 | ? _("error: %B: <corrupt x86 ISA needed size: 0x%x>") |
| 1037 | : _("error: %B: <corrupt x86 feature size: 0x%x>"))), |
| 1038 | abfd, datasz); |
| 1039 | return property_corrupt; |
| 1040 | } |
| 1041 | prop = _bfd_elf_get_property (abfd, type, datasz); |
| 1042 | /* Combine properties of the same type. */ |
| 1043 | prop->u.number |= bfd_h_get_32 (abfd, ptr); |
| 1044 | prop->pr_kind = property_number; |
| 1045 | break; |
| 1046 | |
| 1047 | default: |
| 1048 | return property_ignored; |
| 1049 | } |
| 1050 | |
| 1051 | return property_number; |
| 1052 | } |
| 1053 | |
| 1054 | /* Merge x86 GNU property BPROP with APROP. If APROP isn't NULL, |
| 1055 | return TRUE if APROP is updated. Otherwise, return TRUE if BPROP |
| 1056 | should be merged with ABFD. */ |
| 1057 | |
| 1058 | bfd_boolean |
| 1059 | _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info, |
| 1060 | bfd *abfd ATTRIBUTE_UNUSED, |
| 1061 | elf_property *aprop, |
| 1062 | elf_property *bprop) |
| 1063 | { |
| 1064 | unsigned int number, features; |
| 1065 | bfd_boolean updated = FALSE; |
| 1066 | unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type; |
| 1067 | |
| 1068 | switch (pr_type) |
| 1069 | { |
| 1070 | case GNU_PROPERTY_X86_ISA_1_USED: |
| 1071 | case GNU_PROPERTY_X86_ISA_1_NEEDED: |
| 1072 | if (aprop != NULL && bprop != NULL) |
| 1073 | { |
| 1074 | number = aprop->u.number; |
| 1075 | aprop->u.number = number | bprop->u.number; |
| 1076 | updated = number != (unsigned int) aprop->u.number; |
| 1077 | } |
| 1078 | else |
| 1079 | { |
| 1080 | /* Return TRUE if APROP is NULL to indicate that BPROP should |
| 1081 | be added to ABFD. */ |
| 1082 | updated = aprop == NULL; |
| 1083 | } |
| 1084 | break; |
| 1085 | |
| 1086 | case GNU_PROPERTY_X86_FEATURE_1_AND: |
| 1087 | /* Only one of APROP and BPROP can be NULL: |
| 1088 | 1. APROP & BPROP when both APROP and BPROP aren't NULL. |
| 1089 | 2. If APROP is NULL, remove x86 feature. |
| 1090 | 3. Otherwise, do nothing. |
| 1091 | */ |
| 1092 | if (aprop != NULL && bprop != NULL) |
| 1093 | { |
| 1094 | features = 0; |
| 1095 | if (info->ibt) |
| 1096 | features = GNU_PROPERTY_X86_FEATURE_1_IBT; |
| 1097 | if (info->shstk) |
| 1098 | features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK; |
| 1099 | number = aprop->u.number; |
| 1100 | /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and |
| 1101 | GNU_PROPERTY_X86_FEATURE_1_SHSTK. */ |
| 1102 | aprop->u.number = (number & bprop->u.number) | features; |
| 1103 | updated = number != (unsigned int) aprop->u.number; |
| 1104 | /* Remove the property if all feature bits are cleared. */ |
| 1105 | if (aprop->u.number == 0) |
| 1106 | aprop->pr_kind = property_remove; |
| 1107 | } |
| 1108 | else |
| 1109 | { |
| 1110 | features = 0; |
| 1111 | if (info->ibt) |
| 1112 | features = GNU_PROPERTY_X86_FEATURE_1_IBT; |
| 1113 | if (info->shstk) |
| 1114 | features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK; |
| 1115 | if (features) |
| 1116 | { |
| 1117 | /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and |
| 1118 | GNU_PROPERTY_X86_FEATURE_1_SHSTK. */ |
| 1119 | if (aprop != NULL) |
| 1120 | { |
| 1121 | number = aprop->u.number; |
| 1122 | aprop->u.number = number | features; |
| 1123 | updated = number != (unsigned int) aprop->u.number; |
| 1124 | } |
| 1125 | else |
| 1126 | { |
| 1127 | bprop->u.number |= features; |
| 1128 | updated = TRUE; |
| 1129 | } |
| 1130 | } |
| 1131 | else if (aprop != NULL) |
| 1132 | { |
| 1133 | aprop->pr_kind = property_remove; |
| 1134 | updated = TRUE; |
| 1135 | } |
| 1136 | } |
| 1137 | break; |
| 1138 | |
| 1139 | default: |
| 1140 | /* Never should happen. */ |
| 1141 | abort (); |
| 1142 | } |
| 1143 | |
| 1144 | return updated; |
| 1145 | } |
| 1146 | |
| 1147 | /* Set up x86 GNU properties. Return the first relocatable ELF input |
| 1148 | with GNU properties if found. Otherwise, return NULL. */ |
| 1149 | |
| 1150 | bfd * |
| 1151 | _bfd_x86_elf_link_setup_gnu_properties |
| 1152 | (struct bfd_link_info *info, |
| 1153 | struct elf_x86_plt_layout_table *plt_layout) |
| 1154 | { |
| 1155 | bfd_boolean normal_target; |
| 1156 | bfd_boolean lazy_plt; |
| 1157 | asection *sec, *pltsec; |
| 1158 | bfd *dynobj; |
| 1159 | bfd_boolean use_ibt_plt; |
| 1160 | unsigned int plt_alignment, features; |
| 1161 | struct elf_x86_link_hash_table *htab; |
| 1162 | bfd *pbfd; |
| 1163 | bfd *ebfd = NULL; |
| 1164 | elf_property *prop; |
| 1165 | const struct elf_backend_data *bed; |
| 1166 | unsigned int class_align = ABI_64_P (info->output_bfd) ? 3 : 2; |
| 1167 | unsigned int got_align; |
| 1168 | |
| 1169 | features = 0; |
| 1170 | if (info->ibt) |
| 1171 | features = GNU_PROPERTY_X86_FEATURE_1_IBT; |
| 1172 | if (info->shstk) |
| 1173 | features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK; |
| 1174 | |
| 1175 | /* Find a normal input file with GNU property note. */ |
| 1176 | for (pbfd = info->input_bfds; |
| 1177 | pbfd != NULL; |
| 1178 | pbfd = pbfd->link.next) |
| 1179 | if (bfd_get_flavour (pbfd) == bfd_target_elf_flavour |
| 1180 | && bfd_count_sections (pbfd) != 0) |
| 1181 | { |
| 1182 | ebfd = pbfd; |
| 1183 | |
| 1184 | if (elf_properties (pbfd) != NULL) |
| 1185 | break; |
| 1186 | } |
| 1187 | |
| 1188 | if (ebfd != NULL && features) |
| 1189 | { |
| 1190 | /* If features is set, add GNU_PROPERTY_X86_FEATURE_1_IBT and |
| 1191 | GNU_PROPERTY_X86_FEATURE_1_SHSTK. */ |
| 1192 | prop = _bfd_elf_get_property (ebfd, |
| 1193 | GNU_PROPERTY_X86_FEATURE_1_AND, |
| 1194 | 4); |
| 1195 | prop->u.number |= features; |
| 1196 | prop->pr_kind = property_number; |
| 1197 | |
| 1198 | /* Create the GNU property note section if needed. */ |
| 1199 | if (pbfd == NULL) |
| 1200 | { |
| 1201 | sec = bfd_make_section_with_flags (ebfd, |
| 1202 | NOTE_GNU_PROPERTY_SECTION_NAME, |
| 1203 | (SEC_ALLOC |
| 1204 | | SEC_LOAD |
| 1205 | | SEC_IN_MEMORY |
| 1206 | | SEC_READONLY |
| 1207 | | SEC_HAS_CONTENTS |
| 1208 | | SEC_DATA)); |
| 1209 | if (sec == NULL) |
| 1210 | info->callbacks->einfo (_("%F: failed to create GNU property section\n")); |
| 1211 | |
| 1212 | if (!bfd_set_section_alignment (ebfd, sec, class_align)) |
| 1213 | { |
| 1214 | error_alignment: |
| 1215 | info->callbacks->einfo (_("%F%A: failed to align section\n"), |
| 1216 | sec); |
| 1217 | } |
| 1218 | |
| 1219 | elf_section_type (sec) = SHT_NOTE; |
| 1220 | } |
| 1221 | } |
| 1222 | |
| 1223 | pbfd = _bfd_elf_link_setup_gnu_properties (info); |
| 1224 | |
| 1225 | if (bfd_link_relocatable (info)) |
| 1226 | return pbfd; |
| 1227 | |
| 1228 | bed = get_elf_backend_data (info->output_bfd); |
| 1229 | |
| 1230 | htab = elf_x86_hash_table (info, bed->target_id); |
| 1231 | if (htab == NULL) |
| 1232 | return pbfd; |
| 1233 | |
| 1234 | htab->is_vxworks = plt_layout->is_vxworks; |
| 1235 | |
| 1236 | use_ibt_plt = info->ibtplt || info->ibt; |
| 1237 | if (!use_ibt_plt && pbfd != NULL) |
| 1238 | { |
| 1239 | /* Check if GNU_PROPERTY_X86_FEATURE_1_IBT is on. */ |
| 1240 | elf_property_list *p; |
| 1241 | |
| 1242 | /* The property list is sorted in order of type. */ |
| 1243 | for (p = elf_properties (pbfd); p; p = p->next) |
| 1244 | { |
| 1245 | if (GNU_PROPERTY_X86_FEATURE_1_AND == p->property.pr_type) |
| 1246 | { |
| 1247 | use_ibt_plt = !!(p->property.u.number |
| 1248 | & GNU_PROPERTY_X86_FEATURE_1_IBT); |
| 1249 | break; |
| 1250 | } |
| 1251 | else if (GNU_PROPERTY_X86_FEATURE_1_AND < p->property.pr_type) |
| 1252 | break; |
| 1253 | } |
| 1254 | } |
| 1255 | |
| 1256 | dynobj = htab->elf.dynobj; |
| 1257 | |
| 1258 | /* Set htab->elf.dynobj here so that there is no need to check and |
| 1259 | set it in check_relocs. */ |
| 1260 | if (dynobj == NULL) |
| 1261 | { |
| 1262 | if (pbfd != NULL) |
| 1263 | { |
| 1264 | htab->elf.dynobj = pbfd; |
| 1265 | dynobj = pbfd; |
| 1266 | } |
| 1267 | else |
| 1268 | { |
| 1269 | bfd *abfd; |
| 1270 | |
| 1271 | /* Find a normal input file to hold linker created |
| 1272 | sections. */ |
| 1273 | for (abfd = info->input_bfds; |
| 1274 | abfd != NULL; |
| 1275 | abfd = abfd->link.next) |
| 1276 | if (bfd_get_flavour (abfd) == bfd_target_elf_flavour |
| 1277 | && (abfd->flags |
| 1278 | & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0) |
| 1279 | { |
| 1280 | htab->elf.dynobj = abfd; |
| 1281 | dynobj = abfd; |
| 1282 | break; |
| 1283 | } |
| 1284 | } |
| 1285 | } |
| 1286 | |
| 1287 | /* Even when lazy binding is disabled by "-z now", the PLT0 entry may |
| 1288 | still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for |
| 1289 | canonical function address. */ |
| 1290 | htab->plt.has_plt0 = 1; |
| 1291 | normal_target = plt_layout->normal_target; |
| 1292 | |
| 1293 | if (normal_target) |
| 1294 | { |
| 1295 | if (use_ibt_plt) |
| 1296 | { |
| 1297 | htab->lazy_plt = plt_layout->lazy_ibt_plt; |
| 1298 | htab->non_lazy_plt = plt_layout->non_lazy_ibt_plt; |
| 1299 | } |
| 1300 | else |
| 1301 | { |
| 1302 | htab->lazy_plt = plt_layout->lazy_plt; |
| 1303 | htab->non_lazy_plt = plt_layout->non_lazy_plt; |
| 1304 | } |
| 1305 | } |
| 1306 | else |
| 1307 | { |
| 1308 | htab->lazy_plt = plt_layout->lazy_plt; |
| 1309 | htab->non_lazy_plt = NULL; |
| 1310 | } |
| 1311 | |
| 1312 | pltsec = htab->elf.splt; |
| 1313 | |
| 1314 | /* If the non-lazy PLT is available, use it for all PLT entries if |
| 1315 | there are no PLT0 or no .plt section. */ |
| 1316 | if (htab->non_lazy_plt != NULL |
| 1317 | && (!htab->plt.has_plt0 || pltsec == NULL)) |
| 1318 | { |
| 1319 | lazy_plt = FALSE; |
| 1320 | if (bfd_link_pic (info)) |
| 1321 | htab->plt.plt_entry = htab->non_lazy_plt->pic_plt_entry; |
| 1322 | else |
| 1323 | htab->plt.plt_entry = htab->non_lazy_plt->plt_entry; |
| 1324 | htab->plt.plt_entry_size = htab->non_lazy_plt->plt_entry_size; |
| 1325 | htab->plt.plt_got_offset = htab->non_lazy_plt->plt_got_offset; |
| 1326 | htab->plt.plt_got_insn_size |
| 1327 | = htab->non_lazy_plt->plt_got_insn_size; |
| 1328 | htab->plt.eh_frame_plt_size |
| 1329 | = htab->non_lazy_plt->eh_frame_plt_size; |
| 1330 | htab->plt.eh_frame_plt = htab->non_lazy_plt->eh_frame_plt; |
| 1331 | } |
| 1332 | else |
| 1333 | { |
| 1334 | lazy_plt = TRUE; |
| 1335 | if (bfd_link_pic (info)) |
| 1336 | { |
| 1337 | htab->plt.plt0_entry = htab->lazy_plt->pic_plt0_entry; |
| 1338 | htab->plt.plt_entry = htab->lazy_plt->pic_plt_entry; |
| 1339 | } |
| 1340 | else |
| 1341 | { |
| 1342 | htab->plt.plt0_entry = htab->lazy_plt->plt0_entry; |
| 1343 | htab->plt.plt_entry = htab->lazy_plt->plt_entry; |
| 1344 | } |
| 1345 | htab->plt.plt_entry_size = htab->lazy_plt->plt_entry_size; |
| 1346 | htab->plt.plt_got_offset = htab->lazy_plt->plt_got_offset; |
| 1347 | htab->plt.plt_got_insn_size |
| 1348 | = htab->lazy_plt->plt_got_insn_size; |
| 1349 | htab->plt.eh_frame_plt_size |
| 1350 | = htab->lazy_plt->eh_frame_plt_size; |
| 1351 | htab->plt.eh_frame_plt = htab->lazy_plt->eh_frame_plt; |
| 1352 | } |
| 1353 | |
| 1354 | /* Return if there are no normal input files. */ |
| 1355 | if (dynobj == NULL) |
| 1356 | return pbfd; |
| 1357 | |
| 1358 | if (htab->is_vxworks |
| 1359 | && !elf_vxworks_create_dynamic_sections (dynobj, info, |
| 1360 | &htab->srelplt2)) |
| 1361 | { |
| 1362 | info->callbacks->einfo (_("%F: failed to create VxWorks dynamic sections\n")); |
| 1363 | return pbfd; |
| 1364 | } |
| 1365 | |
| 1366 | /* Since create_dynamic_sections isn't always called, but GOT |
| 1367 | relocations need GOT relocations, create them here so that we |
| 1368 | don't need to do it in check_relocs. */ |
| 1369 | if (htab->elf.sgot == NULL |
| 1370 | && !_bfd_elf_create_got_section (dynobj, info)) |
| 1371 | info->callbacks->einfo (_("%F: failed to create GOT sections\n")); |
| 1372 | |
| 1373 | got_align = (bed->target_id == X86_64_ELF_DATA) ? 3 : 2; |
| 1374 | |
| 1375 | /* Align .got and .got.plt sections to their entry size. Do it here |
| 1376 | instead of in create_dynamic_sections so that they are always |
| 1377 | properly aligned even if create_dynamic_sections isn't called. */ |
| 1378 | sec = htab->elf.sgot; |
| 1379 | if (!bfd_set_section_alignment (dynobj, sec, got_align)) |
| 1380 | goto error_alignment; |
| 1381 | |
| 1382 | sec = htab->elf.sgotplt; |
| 1383 | if (!bfd_set_section_alignment (dynobj, sec, got_align)) |
| 1384 | goto error_alignment; |
| 1385 | |
| 1386 | /* Create the ifunc sections here so that check_relocs can be |
| 1387 | simplified. */ |
| 1388 | if (!_bfd_elf_create_ifunc_sections (dynobj, info)) |
| 1389 | info->callbacks->einfo (_("%F: failed to create ifunc sections\n")); |
| 1390 | |
| 1391 | plt_alignment = bfd_log2 (htab->plt.plt_entry_size); |
| 1392 | |
| 1393 | if (pltsec != NULL) |
| 1394 | { |
| 1395 | /* Whe creating executable, set the contents of the .interp |
| 1396 | section to the interpreter. */ |
| 1397 | if (bfd_link_executable (info) && !info->nointerp) |
| 1398 | { |
| 1399 | asection *s = bfd_get_linker_section (dynobj, ".interp"); |
| 1400 | if (s == NULL) |
| 1401 | abort (); |
| 1402 | s->size = htab->dynamic_interpreter_size; |
| 1403 | s->contents = (unsigned char *) htab->dynamic_interpreter; |
| 1404 | htab->interp = s; |
| 1405 | } |
| 1406 | |
| 1407 | /* Don't change PLT section alignment for NaCl since it uses |
| 1408 | 64-byte PLT entry and sets PLT section alignment to 32 |
| 1409 | bytes. Don't create additional PLT sections for NaCl. */ |
| 1410 | if (normal_target) |
| 1411 | { |
| 1412 | flagword pltflags = (bed->dynamic_sec_flags |
| 1413 | | SEC_ALLOC |
| 1414 | | SEC_CODE |
| 1415 | | SEC_LOAD |
| 1416 | | SEC_READONLY); |
| 1417 | unsigned int non_lazy_plt_alignment |
| 1418 | = bfd_log2 (htab->non_lazy_plt->plt_entry_size); |
| 1419 | |
| 1420 | sec = pltsec; |
| 1421 | if (!bfd_set_section_alignment (sec->owner, sec, |
| 1422 | plt_alignment)) |
| 1423 | goto error_alignment; |
| 1424 | |
| 1425 | /* Create the GOT procedure linkage table. */ |
| 1426 | sec = bfd_make_section_anyway_with_flags (dynobj, |
| 1427 | ".plt.got", |
| 1428 | pltflags); |
| 1429 | if (sec == NULL) |
| 1430 | info->callbacks->einfo (_("%F: failed to create GOT PLT section\n")); |
| 1431 | |
| 1432 | if (!bfd_set_section_alignment (dynobj, sec, |
| 1433 | non_lazy_plt_alignment)) |
| 1434 | goto error_alignment; |
| 1435 | |
| 1436 | htab->plt_got = sec; |
| 1437 | |
| 1438 | if (lazy_plt) |
| 1439 | { |
| 1440 | sec = NULL; |
| 1441 | |
| 1442 | if (use_ibt_plt) |
| 1443 | { |
| 1444 | /* Create the second PLT for Intel IBT support. IBT |
| 1445 | PLT is supported only for non-NaCl target and is |
| 1446 | is needed only for lazy binding. */ |
| 1447 | sec = bfd_make_section_anyway_with_flags (dynobj, |
| 1448 | ".plt.sec", |
| 1449 | pltflags); |
| 1450 | if (sec == NULL) |
| 1451 | info->callbacks->einfo (_("%F: failed to create IBT-enabled PLT section\n")); |
| 1452 | |
| 1453 | if (!bfd_set_section_alignment (dynobj, sec, |
| 1454 | plt_alignment)) |
| 1455 | goto error_alignment; |
| 1456 | } |
| 1457 | else if (info->bndplt && ABI_64_P (dynobj)) |
| 1458 | { |
| 1459 | /* Create the second PLT for Intel MPX support. MPX |
| 1460 | PLT is supported only for non-NaCl target in 64-bit |
| 1461 | mode and is needed only for lazy binding. */ |
| 1462 | sec = bfd_make_section_anyway_with_flags (dynobj, |
| 1463 | ".plt.sec", |
| 1464 | pltflags); |
| 1465 | if (sec == NULL) |
| 1466 | info->callbacks->einfo (_("%F: failed to create BND PLT section\n")); |
| 1467 | |
| 1468 | if (!bfd_set_section_alignment (dynobj, sec, |
| 1469 | non_lazy_plt_alignment)) |
| 1470 | goto error_alignment; |
| 1471 | } |
| 1472 | |
| 1473 | htab->plt_second = sec; |
| 1474 | } |
| 1475 | } |
| 1476 | |
| 1477 | if (!info->no_ld_generated_unwind_info) |
| 1478 | { |
| 1479 | flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY |
| 1480 | | SEC_HAS_CONTENTS | SEC_IN_MEMORY |
| 1481 | | SEC_LINKER_CREATED); |
| 1482 | |
| 1483 | sec = bfd_make_section_anyway_with_flags (dynobj, |
| 1484 | ".eh_frame", |
| 1485 | flags); |
| 1486 | if (sec == NULL) |
| 1487 | info->callbacks->einfo (_("%F: failed to create PLT .eh_frame section\n")); |
| 1488 | |
| 1489 | if (!bfd_set_section_alignment (dynobj, sec, class_align)) |
| 1490 | goto error_alignment; |
| 1491 | |
| 1492 | htab->plt_eh_frame = sec; |
| 1493 | |
| 1494 | if (htab->plt_got != NULL) |
| 1495 | { |
| 1496 | sec = bfd_make_section_anyway_with_flags (dynobj, |
| 1497 | ".eh_frame", |
| 1498 | flags); |
| 1499 | if (sec == NULL) |
| 1500 | info->callbacks->einfo (_("%F: failed to create GOT PLT .eh_frame section\n")); |
| 1501 | |
| 1502 | if (!bfd_set_section_alignment (dynobj, sec, class_align)) |
| 1503 | goto error_alignment; |
| 1504 | |
| 1505 | htab->plt_got_eh_frame = sec; |
| 1506 | } |
| 1507 | |
| 1508 | if (htab->plt_second != NULL) |
| 1509 | { |
| 1510 | sec = bfd_make_section_anyway_with_flags (dynobj, |
| 1511 | ".eh_frame", |
| 1512 | flags); |
| 1513 | if (sec == NULL) |
| 1514 | info->callbacks->einfo (_("%F: failed to create the second PLT .eh_frame section\n")); |
| 1515 | |
| 1516 | if (!bfd_set_section_alignment (dynobj, sec, class_align)) |
| 1517 | goto error_alignment; |
| 1518 | |
| 1519 | htab->plt_second_eh_frame = sec; |
| 1520 | } |
| 1521 | } |
| 1522 | } |
| 1523 | |
| 1524 | if (normal_target) |
| 1525 | { |
| 1526 | /* The .iplt section is used for IFUNC symbols in static |
| 1527 | executables. */ |
| 1528 | sec = htab->elf.iplt; |
| 1529 | if (sec != NULL |
| 1530 | && !bfd_set_section_alignment (sec->owner, sec, |
| 1531 | plt_alignment)) |
| 1532 | goto error_alignment; |
| 1533 | } |
| 1534 | |
| 1535 | return pbfd; |
| 1536 | } |