| 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 | /* Allocate space in .plt, .got and associated reloc sections for |
| 83 | dynamic relocs. */ |
| 84 | |
| 85 | static bfd_boolean |
| 86 | elf_x86_allocate_dynrelocs (struct elf_link_hash_entry *h, |
| 87 | void *inf) |
| 88 | { |
| 89 | struct bfd_link_info *info; |
| 90 | struct elf_x86_link_hash_table *htab; |
| 91 | struct elf_x86_link_hash_entry *eh; |
| 92 | struct elf_dyn_relocs *p; |
| 93 | unsigned int plt_entry_size; |
| 94 | bfd_boolean resolved_to_zero; |
| 95 | const struct elf_backend_data *bed; |
| 96 | |
| 97 | if (h->root.type == bfd_link_hash_indirect) |
| 98 | return TRUE; |
| 99 | |
| 100 | eh = (struct elf_x86_link_hash_entry *) h; |
| 101 | |
| 102 | info = (struct bfd_link_info *) inf; |
| 103 | bed = get_elf_backend_data (info->output_bfd); |
| 104 | htab = elf_x86_hash_table (info, bed->target_id); |
| 105 | if (htab == NULL) |
| 106 | return FALSE; |
| 107 | |
| 108 | plt_entry_size = htab->plt.plt_entry_size; |
| 109 | |
| 110 | resolved_to_zero = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, |
| 111 | bed->target_id, |
| 112 | eh->has_got_reloc, |
| 113 | eh); |
| 114 | |
| 115 | /* Clear the reference count of function pointer relocations if |
| 116 | symbol isn't a normal function. */ |
| 117 | if (h->type != STT_FUNC) |
| 118 | eh->func_pointer_refcount = 0; |
| 119 | |
| 120 | /* We can't use the GOT PLT if pointer equality is needed since |
| 121 | finish_dynamic_symbol won't clear symbol value and the dynamic |
| 122 | linker won't update the GOT slot. We will get into an infinite |
| 123 | loop at run-time. */ |
| 124 | if (htab->plt_got != NULL |
| 125 | && h->type != STT_GNU_IFUNC |
| 126 | && !h->pointer_equality_needed |
| 127 | && h->plt.refcount > 0 |
| 128 | && h->got.refcount > 0) |
| 129 | { |
| 130 | /* Don't use the regular PLT if there are both GOT and GOTPLT |
| 131 | reloctions. */ |
| 132 | h->plt.offset = (bfd_vma) -1; |
| 133 | |
| 134 | /* Use the GOT PLT. */ |
| 135 | eh->plt_got.refcount = 1; |
| 136 | } |
| 137 | |
| 138 | /* Since STT_GNU_IFUNC symbol must go through PLT, we handle it |
| 139 | here if it is defined and referenced in a non-shared object. */ |
| 140 | if (h->type == STT_GNU_IFUNC |
| 141 | && h->def_regular) |
| 142 | { |
| 143 | if (_bfd_elf_allocate_ifunc_dyn_relocs (info, h, &eh->dyn_relocs, |
| 144 | &htab->readonly_dynrelocs_against_ifunc, |
| 145 | plt_entry_size, |
| 146 | (htab->plt.has_plt0 |
| 147 | * plt_entry_size), |
| 148 | htab->got_entry_size, |
| 149 | TRUE)) |
| 150 | { |
| 151 | asection *s = htab->plt_second; |
| 152 | if (h->plt.offset != (bfd_vma) -1 && s != NULL) |
| 153 | { |
| 154 | /* Use the second PLT section if it is created. */ |
| 155 | eh->plt_second.offset = s->size; |
| 156 | |
| 157 | /* Make room for this entry in the second PLT section. */ |
| 158 | s->size += htab->non_lazy_plt->plt_entry_size; |
| 159 | } |
| 160 | |
| 161 | return TRUE; |
| 162 | } |
| 163 | else |
| 164 | return FALSE; |
| 165 | } |
| 166 | /* Don't create the PLT entry if there are only function pointer |
| 167 | relocations which can be resolved at run-time. */ |
| 168 | else if (htab->elf.dynamic_sections_created |
| 169 | && (h->plt.refcount > eh->func_pointer_refcount |
| 170 | || eh->plt_got.refcount > 0)) |
| 171 | { |
| 172 | bfd_boolean use_plt_got = eh->plt_got.refcount > 0; |
| 173 | |
| 174 | /* Clear the reference count of function pointer relocations |
| 175 | if PLT is used. */ |
| 176 | eh->func_pointer_refcount = 0; |
| 177 | |
| 178 | /* Make sure this symbol is output as a dynamic symbol. |
| 179 | Undefined weak syms won't yet be marked as dynamic. */ |
| 180 | if (h->dynindx == -1 |
| 181 | && !h->forced_local |
| 182 | && !resolved_to_zero |
| 183 | && h->root.type == bfd_link_hash_undefweak) |
| 184 | { |
| 185 | if (! bfd_elf_link_record_dynamic_symbol (info, h)) |
| 186 | return FALSE; |
| 187 | } |
| 188 | |
| 189 | if (bfd_link_pic (info) |
| 190 | || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h)) |
| 191 | { |
| 192 | asection *s = htab->elf.splt; |
| 193 | asection *second_s = htab->plt_second; |
| 194 | asection *got_s = htab->plt_got; |
| 195 | |
| 196 | /* If this is the first .plt entry, make room for the special |
| 197 | first entry. The .plt section is used by prelink to undo |
| 198 | prelinking for dynamic relocations. */ |
| 199 | if (s->size == 0) |
| 200 | s->size = htab->plt.has_plt0 * plt_entry_size; |
| 201 | |
| 202 | if (use_plt_got) |
| 203 | eh->plt_got.offset = got_s->size; |
| 204 | else |
| 205 | { |
| 206 | h->plt.offset = s->size; |
| 207 | if (second_s) |
| 208 | eh->plt_second.offset = second_s->size; |
| 209 | } |
| 210 | |
| 211 | /* If this symbol is not defined in a regular file, and we are |
| 212 | not generating a shared library, then set the symbol to this |
| 213 | location in the .plt. This is required to make function |
| 214 | pointers compare as equal between the normal executable and |
| 215 | the shared library. */ |
| 216 | if (! bfd_link_pic (info) |
| 217 | && !h->def_regular) |
| 218 | { |
| 219 | if (use_plt_got) |
| 220 | { |
| 221 | /* We need to make a call to the entry of the GOT PLT |
| 222 | instead of regular PLT entry. */ |
| 223 | h->root.u.def.section = got_s; |
| 224 | h->root.u.def.value = eh->plt_got.offset; |
| 225 | } |
| 226 | else |
| 227 | { |
| 228 | if (second_s) |
| 229 | { |
| 230 | /* We need to make a call to the entry of the |
| 231 | second PLT instead of regular PLT entry. */ |
| 232 | h->root.u.def.section = second_s; |
| 233 | h->root.u.def.value = eh->plt_second.offset; |
| 234 | } |
| 235 | else |
| 236 | { |
| 237 | h->root.u.def.section = s; |
| 238 | h->root.u.def.value = h->plt.offset; |
| 239 | } |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | /* Make room for this entry. */ |
| 244 | if (use_plt_got) |
| 245 | got_s->size += htab->non_lazy_plt->plt_entry_size; |
| 246 | else |
| 247 | { |
| 248 | s->size += plt_entry_size; |
| 249 | if (second_s) |
| 250 | second_s->size += htab->non_lazy_plt->plt_entry_size; |
| 251 | |
| 252 | /* We also need to make an entry in the .got.plt section, |
| 253 | which will be placed in the .got section by the linker |
| 254 | script. */ |
| 255 | htab->elf.sgotplt->size += htab->got_entry_size; |
| 256 | |
| 257 | /* There should be no PLT relocation against resolved |
| 258 | undefined weak symbol in executable. */ |
| 259 | if (!resolved_to_zero) |
| 260 | { |
| 261 | /* We also need to make an entry in the .rel.plt |
| 262 | section. */ |
| 263 | htab->elf.srelplt->size += htab->sizeof_reloc; |
| 264 | htab->elf.srelplt->reloc_count++; |
| 265 | } |
| 266 | } |
| 267 | |
| 268 | if (htab->is_vxworks && !bfd_link_pic (info)) |
| 269 | { |
| 270 | /* VxWorks has a second set of relocations for each PLT entry |
| 271 | in executables. They go in a separate relocation section, |
| 272 | which is processed by the kernel loader. */ |
| 273 | |
| 274 | /* There are two relocations for the initial PLT entry: an |
| 275 | R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 4 and an |
| 276 | R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 8. */ |
| 277 | |
| 278 | asection *srelplt2 = htab->srelplt2; |
| 279 | if (h->plt.offset == plt_entry_size) |
| 280 | srelplt2->size += (htab->sizeof_reloc * 2); |
| 281 | |
| 282 | /* There are two extra relocations for each subsequent PLT entry: |
| 283 | an R_386_32 relocation for the GOT entry, and an R_386_32 |
| 284 | relocation for the PLT entry. */ |
| 285 | |
| 286 | srelplt2->size += (htab->sizeof_reloc * 2); |
| 287 | } |
| 288 | } |
| 289 | else |
| 290 | { |
| 291 | eh->plt_got.offset = (bfd_vma) -1; |
| 292 | h->plt.offset = (bfd_vma) -1; |
| 293 | h->needs_plt = 0; |
| 294 | } |
| 295 | } |
| 296 | else |
| 297 | { |
| 298 | eh->plt_got.offset = (bfd_vma) -1; |
| 299 | h->plt.offset = (bfd_vma) -1; |
| 300 | h->needs_plt = 0; |
| 301 | } |
| 302 | |
| 303 | eh->tlsdesc_got = (bfd_vma) -1; |
| 304 | |
| 305 | /* For i386, if R_386_TLS_{IE_32,IE,GOTIE} symbol is now local to the |
| 306 | binary, make it a R_386_TLS_LE_32 requiring no TLS entry. For |
| 307 | x86-64, if R_X86_64_GOTTPOFF symbol is now local to the binary, |
| 308 | make it a R_X86_64_TPOFF32 requiring no GOT entry. */ |
| 309 | if (h->got.refcount > 0 |
| 310 | && bfd_link_executable (info) |
| 311 | && h->dynindx == -1 |
| 312 | && (elf_x86_hash_entry (h)->tls_type & GOT_TLS_IE)) |
| 313 | h->got.offset = (bfd_vma) -1; |
| 314 | else if (h->got.refcount > 0) |
| 315 | { |
| 316 | asection *s; |
| 317 | bfd_boolean dyn; |
| 318 | int tls_type = elf_x86_hash_entry (h)->tls_type; |
| 319 | |
| 320 | /* Make sure this symbol is output as a dynamic symbol. |
| 321 | Undefined weak syms won't yet be marked as dynamic. */ |
| 322 | if (h->dynindx == -1 |
| 323 | && !h->forced_local |
| 324 | && !resolved_to_zero |
| 325 | && h->root.type == bfd_link_hash_undefweak) |
| 326 | { |
| 327 | if (! bfd_elf_link_record_dynamic_symbol (info, h)) |
| 328 | return FALSE; |
| 329 | } |
| 330 | |
| 331 | s = htab->elf.sgot; |
| 332 | if (GOT_TLS_GDESC_P (tls_type)) |
| 333 | { |
| 334 | eh->tlsdesc_got = htab->elf.sgotplt->size |
| 335 | - elf_x86_compute_jump_table_size (htab); |
| 336 | htab->elf.sgotplt->size += 2 * htab->got_entry_size; |
| 337 | h->got.offset = (bfd_vma) -2; |
| 338 | } |
| 339 | if (! GOT_TLS_GDESC_P (tls_type) |
| 340 | || GOT_TLS_GD_P (tls_type)) |
| 341 | { |
| 342 | h->got.offset = s->size; |
| 343 | s->size += htab->got_entry_size; |
| 344 | /* R_386_TLS_GD and R_X86_64_TLSGD need 2 consecutive GOT |
| 345 | slots. */ |
| 346 | if (GOT_TLS_GD_P (tls_type) || tls_type == GOT_TLS_IE_BOTH) |
| 347 | s->size += htab->got_entry_size; |
| 348 | } |
| 349 | dyn = htab->elf.dynamic_sections_created; |
| 350 | /* R_386_TLS_IE_32 needs one dynamic relocation, |
| 351 | R_386_TLS_IE resp. R_386_TLS_GOTIE needs one dynamic relocation, |
| 352 | (but if both R_386_TLS_IE_32 and R_386_TLS_IE is present, we |
| 353 | need two), R_386_TLS_GD and R_X86_64_TLSGD need one if local |
| 354 | symbol and two if global. No dynamic relocation against |
| 355 | resolved undefined weak symbol in executable. */ |
| 356 | if (tls_type == GOT_TLS_IE_BOTH) |
| 357 | htab->elf.srelgot->size += 2 * htab->sizeof_reloc; |
| 358 | else if ((GOT_TLS_GD_P (tls_type) && h->dynindx == -1) |
| 359 | || (tls_type & GOT_TLS_IE)) |
| 360 | htab->elf.srelgot->size += htab->sizeof_reloc; |
| 361 | else if (GOT_TLS_GD_P (tls_type)) |
| 362 | htab->elf.srelgot->size += 2 * htab->sizeof_reloc; |
| 363 | else if (! GOT_TLS_GDESC_P (tls_type) |
| 364 | && ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT |
| 365 | && !resolved_to_zero) |
| 366 | || h->root.type != bfd_link_hash_undefweak) |
| 367 | && (bfd_link_pic (info) |
| 368 | || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h))) |
| 369 | htab->elf.srelgot->size += htab->sizeof_reloc; |
| 370 | if (GOT_TLS_GDESC_P (tls_type)) |
| 371 | { |
| 372 | htab->elf.srelplt->size += htab->sizeof_reloc; |
| 373 | if (bed->target_id == X86_64_ELF_DATA) |
| 374 | htab->tlsdesc_plt = (bfd_vma) -1; |
| 375 | } |
| 376 | } |
| 377 | else |
| 378 | h->got.offset = (bfd_vma) -1; |
| 379 | |
| 380 | if (eh->dyn_relocs == NULL) |
| 381 | return TRUE; |
| 382 | |
| 383 | /* In the shared -Bsymbolic case, discard space allocated for |
| 384 | dynamic pc-relative relocs against symbols which turn out to be |
| 385 | defined in regular objects. For the normal shared case, discard |
| 386 | space for pc-relative relocs that have become local due to symbol |
| 387 | visibility changes. */ |
| 388 | |
| 389 | if (bfd_link_pic (info)) |
| 390 | { |
| 391 | /* Relocs that use pc_count are those that appear on a call |
| 392 | insn, or certain REL relocs that can generated via assembly. |
| 393 | We want calls to protected symbols to resolve directly to the |
| 394 | function rather than going via the plt. If people want |
| 395 | function pointer comparisons to work as expected then they |
| 396 | should avoid writing weird assembly. */ |
| 397 | if (SYMBOL_CALLS_LOCAL (info, h)) |
| 398 | { |
| 399 | struct elf_dyn_relocs **pp; |
| 400 | |
| 401 | for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) |
| 402 | { |
| 403 | p->count -= p->pc_count; |
| 404 | p->pc_count = 0; |
| 405 | if (p->count == 0) |
| 406 | *pp = p->next; |
| 407 | else |
| 408 | pp = &p->next; |
| 409 | } |
| 410 | } |
| 411 | |
| 412 | if (htab->is_vxworks) |
| 413 | { |
| 414 | struct elf_dyn_relocs **pp; |
| 415 | for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) |
| 416 | { |
| 417 | if (strcmp (p->sec->output_section->name, ".tls_vars") == 0) |
| 418 | *pp = p->next; |
| 419 | else |
| 420 | pp = &p->next; |
| 421 | } |
| 422 | } |
| 423 | |
| 424 | /* Also discard relocs on undefined weak syms with non-default |
| 425 | visibility or in PIE. */ |
| 426 | if (eh->dyn_relocs != NULL) |
| 427 | { |
| 428 | if (h->root.type == bfd_link_hash_undefweak) |
| 429 | { |
| 430 | /* Undefined weak symbol is never bound locally in shared |
| 431 | library. */ |
| 432 | if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT |
| 433 | || resolved_to_zero) |
| 434 | { |
| 435 | if (bed->target_id == I386_ELF_DATA |
| 436 | && h->non_got_ref) |
| 437 | { |
| 438 | /* Keep dynamic non-GOT/non-PLT relocation so |
| 439 | that we can branch to 0 without PLT. */ |
| 440 | struct elf_dyn_relocs **pp; |
| 441 | |
| 442 | for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) |
| 443 | if (p->pc_count == 0) |
| 444 | *pp = p->next; |
| 445 | else |
| 446 | { |
| 447 | /* Remove non-R_386_PC32 relocation. */ |
| 448 | p->count = p->pc_count; |
| 449 | pp = &p->next; |
| 450 | } |
| 451 | |
| 452 | /* Make sure undefined weak symbols are output |
| 453 | as dynamic symbols in PIEs for dynamic non-GOT |
| 454 | non-PLT reloations. */ |
| 455 | if (eh->dyn_relocs != NULL |
| 456 | && !bfd_elf_link_record_dynamic_symbol (info, h)) |
| 457 | return FALSE; |
| 458 | } |
| 459 | else |
| 460 | eh->dyn_relocs = NULL; |
| 461 | } |
| 462 | else if (h->dynindx == -1 |
| 463 | && !h->forced_local |
| 464 | && !bfd_elf_link_record_dynamic_symbol (info, h)) |
| 465 | return FALSE; |
| 466 | } |
| 467 | else if (bfd_link_executable (info) |
| 468 | && (h->needs_copy || eh->needs_copy) |
| 469 | && h->def_dynamic |
| 470 | && !h->def_regular) |
| 471 | { |
| 472 | /* NB: needs_copy is set only for x86-64. For PIE, |
| 473 | discard space for pc-relative relocs against symbols |
| 474 | which turn out to need copy relocs. */ |
| 475 | struct elf_dyn_relocs **pp; |
| 476 | |
| 477 | for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) |
| 478 | { |
| 479 | if (p->pc_count != 0) |
| 480 | *pp = p->next; |
| 481 | else |
| 482 | pp = &p->next; |
| 483 | } |
| 484 | } |
| 485 | } |
| 486 | } |
| 487 | else if (ELIMINATE_COPY_RELOCS) |
| 488 | { |
| 489 | /* For the non-shared case, discard space for relocs against |
| 490 | symbols which turn out to need copy relocs or are not |
| 491 | dynamic. Keep dynamic relocations for run-time function |
| 492 | pointer initialization. */ |
| 493 | |
| 494 | if ((!h->non_got_ref |
| 495 | || eh->func_pointer_refcount > 0 |
| 496 | || (h->root.type == bfd_link_hash_undefweak |
| 497 | && !resolved_to_zero)) |
| 498 | && ((h->def_dynamic |
| 499 | && !h->def_regular) |
| 500 | || (htab->elf.dynamic_sections_created |
| 501 | && (h->root.type == bfd_link_hash_undefweak |
| 502 | || h->root.type == bfd_link_hash_undefined)))) |
| 503 | { |
| 504 | /* Make sure this symbol is output as a dynamic symbol. |
| 505 | Undefined weak syms won't yet be marked as dynamic. */ |
| 506 | if (h->dynindx == -1 |
| 507 | && !h->forced_local |
| 508 | && !resolved_to_zero |
| 509 | && h->root.type == bfd_link_hash_undefweak |
| 510 | && ! bfd_elf_link_record_dynamic_symbol (info, h)) |
| 511 | return FALSE; |
| 512 | |
| 513 | /* If that succeeded, we know we'll be keeping all the |
| 514 | relocs. */ |
| 515 | if (h->dynindx != -1) |
| 516 | goto keep; |
| 517 | } |
| 518 | |
| 519 | eh->dyn_relocs = NULL; |
| 520 | eh->func_pointer_refcount = 0; |
| 521 | |
| 522 | keep: ; |
| 523 | } |
| 524 | |
| 525 | /* Finally, allocate space. */ |
| 526 | for (p = eh->dyn_relocs; p != NULL; p = p->next) |
| 527 | { |
| 528 | asection *sreloc; |
| 529 | |
| 530 | sreloc = elf_section_data (p->sec)->sreloc; |
| 531 | |
| 532 | BFD_ASSERT (sreloc != NULL); |
| 533 | sreloc->size += p->count * htab->sizeof_reloc; |
| 534 | } |
| 535 | |
| 536 | return TRUE; |
| 537 | } |
| 538 | |
| 539 | /* Find any dynamic relocs that apply to read-only sections. */ |
| 540 | |
| 541 | bfd_boolean |
| 542 | _bfd_x86_elf_readonly_dynrelocs (struct elf_link_hash_entry *h, |
| 543 | void *inf) |
| 544 | { |
| 545 | struct elf_x86_link_hash_entry *eh; |
| 546 | struct elf_dyn_relocs *p; |
| 547 | |
| 548 | /* Skip local IFUNC symbols. */ |
| 549 | if (h->forced_local && h->type == STT_GNU_IFUNC) |
| 550 | return TRUE; |
| 551 | |
| 552 | eh = (struct elf_x86_link_hash_entry *) h; |
| 553 | for (p = eh->dyn_relocs; p != NULL; p = p->next) |
| 554 | { |
| 555 | asection *s = p->sec->output_section; |
| 556 | |
| 557 | if (s != NULL && (s->flags & SEC_READONLY) != 0) |
| 558 | { |
| 559 | struct bfd_link_info *info = (struct bfd_link_info *) inf; |
| 560 | |
| 561 | info->flags |= DF_TEXTREL; |
| 562 | |
| 563 | if ((info->warn_shared_textrel && bfd_link_pic (info)) |
| 564 | || info->error_textrel) |
| 565 | /* xgettext:c-format */ |
| 566 | info->callbacks->einfo (_("%P: %B: warning: relocation against `%s' in readonly section `%A'\n"), |
| 567 | p->sec->owner, h->root.root.string, |
| 568 | p->sec); |
| 569 | |
| 570 | /* Not an error, just cut short the traversal. */ |
| 571 | return FALSE; |
| 572 | } |
| 573 | } |
| 574 | return TRUE; |
| 575 | } |
| 576 | |
| 577 | /* Allocate space in .plt, .got and associated reloc sections for |
| 578 | local dynamic relocs. */ |
| 579 | |
| 580 | static bfd_boolean |
| 581 | elf_x86_allocate_local_dynreloc (void **slot, void *inf) |
| 582 | { |
| 583 | struct elf_link_hash_entry *h |
| 584 | = (struct elf_link_hash_entry *) *slot; |
| 585 | |
| 586 | if (h->type != STT_GNU_IFUNC |
| 587 | || !h->def_regular |
| 588 | || !h->ref_regular |
| 589 | || !h->forced_local |
| 590 | || h->root.type != bfd_link_hash_defined) |
| 591 | abort (); |
| 592 | |
| 593 | return elf_x86_allocate_dynrelocs (h, inf); |
| 594 | } |
| 595 | |
| 596 | /* Find and/or create a hash entry for local symbol. */ |
| 597 | |
| 598 | struct elf_link_hash_entry * |
| 599 | _bfd_elf_x86_get_local_sym_hash (struct elf_x86_link_hash_table *htab, |
| 600 | bfd *abfd, const Elf_Internal_Rela *rel, |
| 601 | bfd_boolean create) |
| 602 | { |
| 603 | struct elf_x86_link_hash_entry e, *ret; |
| 604 | asection *sec = abfd->sections; |
| 605 | hashval_t h = ELF_LOCAL_SYMBOL_HASH (sec->id, |
| 606 | htab->r_sym (rel->r_info)); |
| 607 | void **slot; |
| 608 | |
| 609 | e.elf.indx = sec->id; |
| 610 | e.elf.dynstr_index = htab->r_sym (rel->r_info); |
| 611 | slot = htab_find_slot_with_hash (htab->loc_hash_table, &e, h, |
| 612 | create ? INSERT : NO_INSERT); |
| 613 | |
| 614 | if (!slot) |
| 615 | return NULL; |
| 616 | |
| 617 | if (*slot) |
| 618 | { |
| 619 | ret = (struct elf_x86_link_hash_entry *) *slot; |
| 620 | return &ret->elf; |
| 621 | } |
| 622 | |
| 623 | ret = (struct elf_x86_link_hash_entry *) |
| 624 | objalloc_alloc ((struct objalloc *) htab->loc_hash_memory, |
| 625 | sizeof (struct elf_x86_link_hash_entry)); |
| 626 | if (ret) |
| 627 | { |
| 628 | memset (ret, 0, sizeof (*ret)); |
| 629 | ret->elf.indx = sec->id; |
| 630 | ret->elf.dynstr_index = htab->r_sym (rel->r_info); |
| 631 | ret->elf.dynindx = -1; |
| 632 | ret->plt_got.offset = (bfd_vma) -1; |
| 633 | *slot = ret; |
| 634 | } |
| 635 | return &ret->elf; |
| 636 | } |
| 637 | |
| 638 | /* Create an entry in a x86 ELF linker hash table. NB: THIS MUST BE IN |
| 639 | SYNC WITH _bfd_elf_link_hash_newfunc. */ |
| 640 | |
| 641 | struct bfd_hash_entry * |
| 642 | _bfd_x86_elf_link_hash_newfunc (struct bfd_hash_entry *entry, |
| 643 | struct bfd_hash_table *table, |
| 644 | const char *string) |
| 645 | { |
| 646 | /* Allocate the structure if it has not already been allocated by a |
| 647 | subclass. */ |
| 648 | if (entry == NULL) |
| 649 | { |
| 650 | entry = (struct bfd_hash_entry *) |
| 651 | bfd_hash_allocate (table, |
| 652 | sizeof (struct elf_x86_link_hash_entry)); |
| 653 | if (entry == NULL) |
| 654 | return entry; |
| 655 | } |
| 656 | |
| 657 | /* Call the allocation method of the superclass. */ |
| 658 | entry = _bfd_link_hash_newfunc (entry, table, string); |
| 659 | if (entry != NULL) |
| 660 | { |
| 661 | struct elf_x86_link_hash_entry *eh |
| 662 | = (struct elf_x86_link_hash_entry *) entry; |
| 663 | struct elf_link_hash_table *htab |
| 664 | = (struct elf_link_hash_table *) table; |
| 665 | |
| 666 | memset (&eh->elf.size, 0, |
| 667 | (sizeof (struct elf_x86_link_hash_entry) |
| 668 | - offsetof (struct elf_link_hash_entry, size))); |
| 669 | /* Set local fields. */ |
| 670 | eh->elf.indx = -1; |
| 671 | eh->elf.dynindx = -1; |
| 672 | eh->elf.got = htab->init_got_refcount; |
| 673 | eh->elf.plt = htab->init_plt_refcount; |
| 674 | /* Assume that we have been called by a non-ELF symbol reader. |
| 675 | This flag is then reset by the code which reads an ELF input |
| 676 | file. This ensures that a symbol created by a non-ELF symbol |
| 677 | reader will have the flag set correctly. */ |
| 678 | eh->elf.non_elf = 1; |
| 679 | eh->plt_second.offset = (bfd_vma) -1; |
| 680 | eh->plt_got.offset = (bfd_vma) -1; |
| 681 | eh->tlsdesc_got = (bfd_vma) -1; |
| 682 | } |
| 683 | |
| 684 | return entry; |
| 685 | } |
| 686 | |
| 687 | /* Compute a hash of a local hash entry. We use elf_link_hash_entry |
| 688 | for local symbol so that we can handle local STT_GNU_IFUNC symbols |
| 689 | as global symbol. We reuse indx and dynstr_index for local symbol |
| 690 | hash since they aren't used by global symbols in this backend. */ |
| 691 | |
| 692 | hashval_t |
| 693 | _bfd_x86_elf_local_htab_hash (const void *ptr) |
| 694 | { |
| 695 | struct elf_link_hash_entry *h |
| 696 | = (struct elf_link_hash_entry *) ptr; |
| 697 | return ELF_LOCAL_SYMBOL_HASH (h->indx, h->dynstr_index); |
| 698 | } |
| 699 | |
| 700 | /* Compare local hash entries. */ |
| 701 | |
| 702 | int |
| 703 | _bfd_x86_elf_local_htab_eq (const void *ptr1, const void *ptr2) |
| 704 | { |
| 705 | struct elf_link_hash_entry *h1 |
| 706 | = (struct elf_link_hash_entry *) ptr1; |
| 707 | struct elf_link_hash_entry *h2 |
| 708 | = (struct elf_link_hash_entry *) ptr2; |
| 709 | |
| 710 | return h1->indx == h2->indx && h1->dynstr_index == h2->dynstr_index; |
| 711 | } |
| 712 | |
| 713 | /* Destroy an x86 ELF linker hash table. */ |
| 714 | |
| 715 | static void |
| 716 | elf_x86_link_hash_table_free (bfd *obfd) |
| 717 | { |
| 718 | struct elf_x86_link_hash_table *htab |
| 719 | = (struct elf_x86_link_hash_table *) obfd->link.hash; |
| 720 | |
| 721 | if (htab->loc_hash_table) |
| 722 | htab_delete (htab->loc_hash_table); |
| 723 | if (htab->loc_hash_memory) |
| 724 | objalloc_free ((struct objalloc *) htab->loc_hash_memory); |
| 725 | _bfd_elf_link_hash_table_free (obfd); |
| 726 | } |
| 727 | |
| 728 | static bfd_boolean |
| 729 | elf_i386_is_reloc_section (const char *secname) |
| 730 | { |
| 731 | return CONST_STRNEQ (secname, ".rel"); |
| 732 | } |
| 733 | |
| 734 | static bfd_boolean |
| 735 | elf_x86_64_is_reloc_section (const char *secname) |
| 736 | { |
| 737 | return CONST_STRNEQ (secname, ".rela"); |
| 738 | } |
| 739 | |
| 740 | /* Create an x86 ELF linker hash table. */ |
| 741 | |
| 742 | struct bfd_link_hash_table * |
| 743 | _bfd_x86_elf_link_hash_table_create (bfd *abfd) |
| 744 | { |
| 745 | struct elf_x86_link_hash_table *ret; |
| 746 | const struct elf_backend_data *bed; |
| 747 | bfd_size_type amt = sizeof (struct elf_x86_link_hash_table); |
| 748 | |
| 749 | ret = (struct elf_x86_link_hash_table *) bfd_zmalloc (amt); |
| 750 | if (ret == NULL) |
| 751 | return NULL; |
| 752 | |
| 753 | bed = get_elf_backend_data (abfd); |
| 754 | if (!_bfd_elf_link_hash_table_init (&ret->elf, abfd, |
| 755 | _bfd_x86_elf_link_hash_newfunc, |
| 756 | sizeof (struct elf_x86_link_hash_entry), |
| 757 | bed->target_id)) |
| 758 | { |
| 759 | free (ret); |
| 760 | return NULL; |
| 761 | } |
| 762 | |
| 763 | if (bed->target_id == X86_64_ELF_DATA) |
| 764 | { |
| 765 | ret->is_reloc_section = elf_x86_64_is_reloc_section; |
| 766 | ret->dt_reloc = DT_RELA; |
| 767 | ret->dt_reloc_sz = DT_RELASZ; |
| 768 | ret->dt_reloc_ent = DT_RELAENT; |
| 769 | ret->got_entry_size = 8; |
| 770 | ret->tls_get_addr = "__tls_get_addr"; |
| 771 | } |
| 772 | if (ABI_64_P (abfd)) |
| 773 | { |
| 774 | ret->sizeof_reloc = sizeof (Elf64_External_Rela); |
| 775 | ret->pointer_r_type = R_X86_64_64; |
| 776 | ret->dynamic_interpreter = ELF64_DYNAMIC_INTERPRETER; |
| 777 | ret->dynamic_interpreter_size = sizeof ELF64_DYNAMIC_INTERPRETER; |
| 778 | } |
| 779 | else |
| 780 | { |
| 781 | if (bed->target_id == X86_64_ELF_DATA) |
| 782 | { |
| 783 | ret->sizeof_reloc = sizeof (Elf32_External_Rela); |
| 784 | ret->pointer_r_type = R_X86_64_32; |
| 785 | ret->dynamic_interpreter = ELFX32_DYNAMIC_INTERPRETER; |
| 786 | ret->dynamic_interpreter_size |
| 787 | = sizeof ELFX32_DYNAMIC_INTERPRETER; |
| 788 | } |
| 789 | else |
| 790 | { |
| 791 | ret->is_reloc_section = elf_i386_is_reloc_section; |
| 792 | ret->dt_reloc = DT_REL; |
| 793 | ret->dt_reloc_sz = DT_RELSZ; |
| 794 | ret->dt_reloc_ent = DT_RELENT; |
| 795 | ret->sizeof_reloc = sizeof (Elf32_External_Rel); |
| 796 | ret->got_entry_size = 4; |
| 797 | ret->pointer_r_type = R_386_32; |
| 798 | ret->dynamic_interpreter = ELF32_DYNAMIC_INTERPRETER; |
| 799 | ret->dynamic_interpreter_size |
| 800 | = sizeof ELF32_DYNAMIC_INTERPRETER; |
| 801 | ret->tls_get_addr = "___tls_get_addr"; |
| 802 | } |
| 803 | } |
| 804 | ret->target_id = bed->target_id; |
| 805 | |
| 806 | ret->loc_hash_table = htab_try_create (1024, |
| 807 | _bfd_x86_elf_local_htab_hash, |
| 808 | _bfd_x86_elf_local_htab_eq, |
| 809 | NULL); |
| 810 | ret->loc_hash_memory = objalloc_create (); |
| 811 | if (!ret->loc_hash_table || !ret->loc_hash_memory) |
| 812 | { |
| 813 | elf_x86_link_hash_table_free (abfd); |
| 814 | return NULL; |
| 815 | } |
| 816 | ret->elf.root.hash_table_free = elf_x86_link_hash_table_free; |
| 817 | |
| 818 | return &ret->elf.root; |
| 819 | } |
| 820 | |
| 821 | /* Sort relocs into address order. */ |
| 822 | |
| 823 | int |
| 824 | _bfd_x86_elf_compare_relocs (const void *ap, const void *bp) |
| 825 | { |
| 826 | const arelent *a = * (const arelent **) ap; |
| 827 | const arelent *b = * (const arelent **) bp; |
| 828 | |
| 829 | if (a->address > b->address) |
| 830 | return 1; |
| 831 | else if (a->address < b->address) |
| 832 | return -1; |
| 833 | else |
| 834 | return 0; |
| 835 | } |
| 836 | |
| 837 | bfd_boolean |
| 838 | _bfd_x86_elf_link_check_relocs (bfd *abfd, struct bfd_link_info *info) |
| 839 | { |
| 840 | if (!bfd_link_relocatable (info)) |
| 841 | { |
| 842 | /* Check for __tls_get_addr reference. */ |
| 843 | struct elf_x86_link_hash_table *htab; |
| 844 | const struct elf_backend_data *bed = get_elf_backend_data (abfd); |
| 845 | htab = elf_x86_hash_table (info, bed->target_id); |
| 846 | if (htab) |
| 847 | { |
| 848 | struct elf_link_hash_entry *h |
| 849 | = elf_link_hash_lookup (elf_hash_table (info), |
| 850 | htab->tls_get_addr, |
| 851 | FALSE, FALSE, FALSE); |
| 852 | if (h != NULL) |
| 853 | ((struct elf_x86_link_hash_entry *) h)->tls_get_addr = 1; |
| 854 | } |
| 855 | } |
| 856 | |
| 857 | /* Invoke the regular ELF backend linker to do all the work. */ |
| 858 | return _bfd_elf_link_check_relocs (abfd, info); |
| 859 | } |
| 860 | |
| 861 | /* Set the sizes of the dynamic sections. */ |
| 862 | |
| 863 | bfd_boolean |
| 864 | _bfd_x86_elf_size_dynamic_sections (bfd *output_bfd, |
| 865 | struct bfd_link_info *info) |
| 866 | { |
| 867 | struct elf_x86_link_hash_table *htab; |
| 868 | bfd *dynobj; |
| 869 | asection *s; |
| 870 | bfd_boolean relocs; |
| 871 | bfd *ibfd; |
| 872 | const struct elf_backend_data *bed |
| 873 | = get_elf_backend_data (output_bfd); |
| 874 | |
| 875 | htab = elf_x86_hash_table (info, bed->target_id); |
| 876 | if (htab == NULL) |
| 877 | return FALSE; |
| 878 | dynobj = htab->elf.dynobj; |
| 879 | if (dynobj == NULL) |
| 880 | abort (); |
| 881 | |
| 882 | /* Set up .got offsets for local syms, and space for local dynamic |
| 883 | relocs. */ |
| 884 | for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next) |
| 885 | { |
| 886 | bfd_signed_vma *local_got; |
| 887 | bfd_signed_vma *end_local_got; |
| 888 | char *local_tls_type; |
| 889 | bfd_vma *local_tlsdesc_gotent; |
| 890 | bfd_size_type locsymcount; |
| 891 | Elf_Internal_Shdr *symtab_hdr; |
| 892 | asection *srel; |
| 893 | |
| 894 | if (! is_x86_elf (ibfd, htab)) |
| 895 | continue; |
| 896 | |
| 897 | for (s = ibfd->sections; s != NULL; s = s->next) |
| 898 | { |
| 899 | struct elf_dyn_relocs *p; |
| 900 | |
| 901 | for (p = ((struct elf_dyn_relocs *) |
| 902 | elf_section_data (s)->local_dynrel); |
| 903 | p != NULL; |
| 904 | p = p->next) |
| 905 | { |
| 906 | if (!bfd_is_abs_section (p->sec) |
| 907 | && bfd_is_abs_section (p->sec->output_section)) |
| 908 | { |
| 909 | /* Input section has been discarded, either because |
| 910 | it is a copy of a linkonce section or due to |
| 911 | linker script /DISCARD/, so we'll be discarding |
| 912 | the relocs too. */ |
| 913 | } |
| 914 | else if (htab->is_vxworks |
| 915 | && strcmp (p->sec->output_section->name, |
| 916 | ".tls_vars") == 0) |
| 917 | { |
| 918 | /* Relocations in vxworks .tls_vars sections are |
| 919 | handled specially by the loader. */ |
| 920 | } |
| 921 | else if (p->count != 0) |
| 922 | { |
| 923 | srel = elf_section_data (p->sec)->sreloc; |
| 924 | srel->size += p->count * htab->sizeof_reloc; |
| 925 | if ((p->sec->output_section->flags & SEC_READONLY) != 0 |
| 926 | && (info->flags & DF_TEXTREL) == 0) |
| 927 | { |
| 928 | info->flags |= DF_TEXTREL; |
| 929 | if ((info->warn_shared_textrel && bfd_link_pic (info)) |
| 930 | || info->error_textrel) |
| 931 | /* xgettext:c-format */ |
| 932 | info->callbacks->einfo (_("%P: %B: warning: relocation in readonly section `%A'\n"), |
| 933 | p->sec->owner, p->sec); |
| 934 | } |
| 935 | } |
| 936 | } |
| 937 | } |
| 938 | |
| 939 | local_got = elf_local_got_refcounts (ibfd); |
| 940 | if (!local_got) |
| 941 | continue; |
| 942 | |
| 943 | symtab_hdr = &elf_symtab_hdr (ibfd); |
| 944 | locsymcount = symtab_hdr->sh_info; |
| 945 | end_local_got = local_got + locsymcount; |
| 946 | local_tls_type = elf_x86_local_got_tls_type (ibfd); |
| 947 | local_tlsdesc_gotent = elf_x86_local_tlsdesc_gotent (ibfd); |
| 948 | s = htab->elf.sgot; |
| 949 | srel = htab->elf.srelgot; |
| 950 | for (; local_got < end_local_got; |
| 951 | ++local_got, ++local_tls_type, ++local_tlsdesc_gotent) |
| 952 | { |
| 953 | *local_tlsdesc_gotent = (bfd_vma) -1; |
| 954 | if (*local_got > 0) |
| 955 | { |
| 956 | if (GOT_TLS_GDESC_P (*local_tls_type)) |
| 957 | { |
| 958 | *local_tlsdesc_gotent = htab->elf.sgotplt->size |
| 959 | - elf_x86_compute_jump_table_size (htab); |
| 960 | htab->elf.sgotplt->size += 2 * htab->got_entry_size; |
| 961 | *local_got = (bfd_vma) -2; |
| 962 | } |
| 963 | if (! GOT_TLS_GDESC_P (*local_tls_type) |
| 964 | || GOT_TLS_GD_P (*local_tls_type)) |
| 965 | { |
| 966 | *local_got = s->size; |
| 967 | s->size += htab->got_entry_size; |
| 968 | if (GOT_TLS_GD_P (*local_tls_type) |
| 969 | || *local_tls_type == GOT_TLS_IE_BOTH) |
| 970 | s->size += htab->got_entry_size; |
| 971 | } |
| 972 | if (bfd_link_pic (info) |
| 973 | || GOT_TLS_GD_ANY_P (*local_tls_type) |
| 974 | || (*local_tls_type & GOT_TLS_IE)) |
| 975 | { |
| 976 | if (*local_tls_type == GOT_TLS_IE_BOTH) |
| 977 | srel->size += 2 * htab->sizeof_reloc; |
| 978 | else if (GOT_TLS_GD_P (*local_tls_type) |
| 979 | || ! GOT_TLS_GDESC_P (*local_tls_type)) |
| 980 | srel->size += htab->sizeof_reloc; |
| 981 | if (GOT_TLS_GDESC_P (*local_tls_type)) |
| 982 | { |
| 983 | htab->elf.srelplt->size += htab->sizeof_reloc; |
| 984 | if (bed->target_id == X86_64_ELF_DATA) |
| 985 | htab->tlsdesc_plt = (bfd_vma) -1; |
| 986 | } |
| 987 | } |
| 988 | } |
| 989 | else |
| 990 | *local_got = (bfd_vma) -1; |
| 991 | } |
| 992 | } |
| 993 | |
| 994 | if (htab->tls_ld_or_ldm_got.refcount > 0) |
| 995 | { |
| 996 | /* Allocate 2 got entries and 1 dynamic reloc for R_386_TLS_LDM |
| 997 | or R_X86_64_TLSLD relocs. */ |
| 998 | htab->tls_ld_or_ldm_got.offset = htab->elf.sgot->size; |
| 999 | htab->elf.sgot->size += 2 * htab->got_entry_size; |
| 1000 | htab->elf.srelgot->size += htab->sizeof_reloc; |
| 1001 | } |
| 1002 | else |
| 1003 | htab->tls_ld_or_ldm_got.offset = -1; |
| 1004 | |
| 1005 | /* Allocate global sym .plt and .got entries, and space for global |
| 1006 | sym dynamic relocs. */ |
| 1007 | elf_link_hash_traverse (&htab->elf, elf_x86_allocate_dynrelocs, |
| 1008 | info); |
| 1009 | |
| 1010 | /* Allocate .plt and .got entries, and space for local symbols. */ |
| 1011 | htab_traverse (htab->loc_hash_table, elf_x86_allocate_local_dynreloc, |
| 1012 | info); |
| 1013 | |
| 1014 | /* For every jump slot reserved in the sgotplt, reloc_count is |
| 1015 | incremented. However, when we reserve space for TLS descriptors, |
| 1016 | it's not incremented, so in order to compute the space reserved |
| 1017 | for them, it suffices to multiply the reloc count by the jump |
| 1018 | slot size. |
| 1019 | |
| 1020 | PR ld/13302: We start next_irelative_index at the end of .rela.plt |
| 1021 | so that R_{386,X86_64}_IRELATIVE entries come last. */ |
| 1022 | if (htab->elf.srelplt) |
| 1023 | { |
| 1024 | htab->next_tls_desc_index = htab->elf.srelplt->reloc_count; |
| 1025 | htab->sgotplt_jump_table_size |
| 1026 | = elf_x86_compute_jump_table_size (htab); |
| 1027 | htab->next_irelative_index = htab->elf.srelplt->reloc_count - 1; |
| 1028 | } |
| 1029 | else if (htab->elf.irelplt) |
| 1030 | htab->next_irelative_index = htab->elf.irelplt->reloc_count - 1; |
| 1031 | |
| 1032 | if (htab->tlsdesc_plt) |
| 1033 | { |
| 1034 | /* NB: tlsdesc_plt is set only for x86-64. If we're not using |
| 1035 | lazy TLS relocations, don't generate the PLT and GOT entries |
| 1036 | they require. */ |
| 1037 | if ((info->flags & DF_BIND_NOW)) |
| 1038 | htab->tlsdesc_plt = 0; |
| 1039 | else |
| 1040 | { |
| 1041 | htab->tlsdesc_got = htab->elf.sgot->size; |
| 1042 | htab->elf.sgot->size += htab->got_entry_size; |
| 1043 | /* Reserve room for the initial entry. |
| 1044 | FIXME: we could probably do away with it in this case. */ |
| 1045 | if (htab->elf.splt->size == 0) |
| 1046 | htab->elf.splt->size = htab->plt.plt_entry_size; |
| 1047 | htab->tlsdesc_plt = htab->elf.splt->size; |
| 1048 | htab->elf.splt->size += htab->plt.plt_entry_size; |
| 1049 | } |
| 1050 | } |
| 1051 | |
| 1052 | if (htab->elf.sgotplt) |
| 1053 | { |
| 1054 | /* Don't allocate .got.plt section if there are no GOT nor PLT |
| 1055 | entries and there is no reference to _GLOBAL_OFFSET_TABLE_. */ |
| 1056 | if ((htab->elf.hgot == NULL |
| 1057 | || !htab->elf.hgot->ref_regular_nonweak) |
| 1058 | && (htab->elf.sgotplt->size == bed->got_header_size) |
| 1059 | && (htab->elf.splt == NULL |
| 1060 | || htab->elf.splt->size == 0) |
| 1061 | && (htab->elf.sgot == NULL |
| 1062 | || htab->elf.sgot->size == 0) |
| 1063 | && (htab->elf.iplt == NULL |
| 1064 | || htab->elf.iplt->size == 0) |
| 1065 | && (htab->elf.igotplt == NULL |
| 1066 | || htab->elf.igotplt->size == 0)) |
| 1067 | htab->elf.sgotplt->size = 0; |
| 1068 | } |
| 1069 | |
| 1070 | if (_bfd_elf_eh_frame_present (info)) |
| 1071 | { |
| 1072 | if (htab->plt_eh_frame != NULL |
| 1073 | && htab->elf.splt != NULL |
| 1074 | && htab->elf.splt->size != 0 |
| 1075 | && !bfd_is_abs_section (htab->elf.splt->output_section)) |
| 1076 | htab->plt_eh_frame->size = htab->plt.eh_frame_plt_size; |
| 1077 | |
| 1078 | if (htab->plt_got_eh_frame != NULL |
| 1079 | && htab->plt_got != NULL |
| 1080 | && htab->plt_got->size != 0 |
| 1081 | && !bfd_is_abs_section (htab->plt_got->output_section)) |
| 1082 | htab->plt_got_eh_frame->size |
| 1083 | = htab->non_lazy_plt->eh_frame_plt_size; |
| 1084 | |
| 1085 | /* Unwind info for the second PLT and .plt.got sections are |
| 1086 | identical. */ |
| 1087 | if (htab->plt_second_eh_frame != NULL |
| 1088 | && htab->plt_second != NULL |
| 1089 | && htab->plt_second->size != 0 |
| 1090 | && !bfd_is_abs_section (htab->plt_second->output_section)) |
| 1091 | htab->plt_second_eh_frame->size |
| 1092 | = htab->non_lazy_plt->eh_frame_plt_size; |
| 1093 | } |
| 1094 | |
| 1095 | /* We now have determined the sizes of the various dynamic sections. |
| 1096 | Allocate memory for them. */ |
| 1097 | relocs = FALSE; |
| 1098 | for (s = dynobj->sections; s != NULL; s = s->next) |
| 1099 | { |
| 1100 | bfd_boolean strip_section = TRUE; |
| 1101 | |
| 1102 | if ((s->flags & SEC_LINKER_CREATED) == 0) |
| 1103 | continue; |
| 1104 | |
| 1105 | if (s == htab->elf.splt |
| 1106 | || s == htab->elf.sgot) |
| 1107 | { |
| 1108 | /* Strip this section if we don't need it; see the |
| 1109 | comment below. */ |
| 1110 | /* We'd like to strip these sections if they aren't needed, but if |
| 1111 | we've exported dynamic symbols from them we must leave them. |
| 1112 | It's too late to tell BFD to get rid of the symbols. */ |
| 1113 | |
| 1114 | if (htab->elf.hplt != NULL) |
| 1115 | strip_section = FALSE; |
| 1116 | } |
| 1117 | else if (s == htab->elf.sgotplt |
| 1118 | || s == htab->elf.iplt |
| 1119 | || s == htab->elf.igotplt |
| 1120 | || s == htab->plt_second |
| 1121 | || s == htab->plt_got |
| 1122 | || s == htab->plt_eh_frame |
| 1123 | || s == htab->plt_got_eh_frame |
| 1124 | || s == htab->plt_second_eh_frame |
| 1125 | || s == htab->elf.sdynbss |
| 1126 | || s == htab->elf.sdynrelro) |
| 1127 | { |
| 1128 | /* Strip these too. */ |
| 1129 | } |
| 1130 | else if (htab->is_reloc_section (bfd_get_section_name (dynobj, s))) |
| 1131 | { |
| 1132 | if (s->size != 0 |
| 1133 | && s != htab->elf.srelplt |
| 1134 | && s != htab->srelplt2) |
| 1135 | relocs = TRUE; |
| 1136 | |
| 1137 | /* We use the reloc_count field as a counter if we need |
| 1138 | to copy relocs into the output file. */ |
| 1139 | if (s != htab->elf.srelplt) |
| 1140 | s->reloc_count = 0; |
| 1141 | } |
| 1142 | else |
| 1143 | { |
| 1144 | /* It's not one of our sections, so don't allocate space. */ |
| 1145 | continue; |
| 1146 | } |
| 1147 | |
| 1148 | if (s->size == 0) |
| 1149 | { |
| 1150 | /* If we don't need this section, strip it from the |
| 1151 | output file. This is mostly to handle .rel.bss and |
| 1152 | .rel.plt. We must create both sections in |
| 1153 | create_dynamic_sections, because they must be created |
| 1154 | before the linker maps input sections to output |
| 1155 | sections. The linker does that before |
| 1156 | adjust_dynamic_symbol is called, and it is that |
| 1157 | function which decides whether anything needs to go |
| 1158 | into these sections. */ |
| 1159 | if (strip_section) |
| 1160 | s->flags |= SEC_EXCLUDE; |
| 1161 | continue; |
| 1162 | } |
| 1163 | |
| 1164 | if ((s->flags & SEC_HAS_CONTENTS) == 0) |
| 1165 | continue; |
| 1166 | |
| 1167 | /* Allocate memory for the section contents. We use bfd_zalloc |
| 1168 | here in case unused entries are not reclaimed before the |
| 1169 | section's contents are written out. This should not happen, |
| 1170 | but this way if it does, we get a R_386_NONE or R_X86_64_NONE |
| 1171 | reloc instead of garbage. */ |
| 1172 | s->contents = (unsigned char *) bfd_zalloc (dynobj, s->size); |
| 1173 | if (s->contents == NULL) |
| 1174 | return FALSE; |
| 1175 | } |
| 1176 | |
| 1177 | if (htab->plt_eh_frame != NULL |
| 1178 | && htab->plt_eh_frame->contents != NULL) |
| 1179 | { |
| 1180 | memcpy (htab->plt_eh_frame->contents, |
| 1181 | htab->plt.eh_frame_plt, |
| 1182 | htab->plt_eh_frame->size); |
| 1183 | bfd_put_32 (dynobj, htab->elf.splt->size, |
| 1184 | htab->plt_eh_frame->contents + PLT_FDE_LEN_OFFSET); |
| 1185 | } |
| 1186 | |
| 1187 | if (htab->plt_got_eh_frame != NULL |
| 1188 | && htab->plt_got_eh_frame->contents != NULL) |
| 1189 | { |
| 1190 | memcpy (htab->plt_got_eh_frame->contents, |
| 1191 | htab->non_lazy_plt->eh_frame_plt, |
| 1192 | htab->plt_got_eh_frame->size); |
| 1193 | bfd_put_32 (dynobj, htab->plt_got->size, |
| 1194 | (htab->plt_got_eh_frame->contents |
| 1195 | + PLT_FDE_LEN_OFFSET)); |
| 1196 | } |
| 1197 | |
| 1198 | if (htab->plt_second_eh_frame != NULL |
| 1199 | && htab->plt_second_eh_frame->contents != NULL) |
| 1200 | { |
| 1201 | memcpy (htab->plt_second_eh_frame->contents, |
| 1202 | htab->non_lazy_plt->eh_frame_plt, |
| 1203 | htab->plt_second_eh_frame->size); |
| 1204 | bfd_put_32 (dynobj, htab->plt_second->size, |
| 1205 | (htab->plt_second_eh_frame->contents |
| 1206 | + PLT_FDE_LEN_OFFSET)); |
| 1207 | } |
| 1208 | |
| 1209 | if (htab->elf.dynamic_sections_created) |
| 1210 | { |
| 1211 | /* Add some entries to the .dynamic section. We fill in the |
| 1212 | values later, in elf_{i386,x86_64}_finish_dynamic_sections, |
| 1213 | but we must add the entries now so that we get the correct |
| 1214 | size for the .dynamic section. The DT_DEBUG entry is filled |
| 1215 | in by the dynamic linker and used by the debugger. */ |
| 1216 | #define add_dynamic_entry(TAG, VAL) \ |
| 1217 | _bfd_elf_add_dynamic_entry (info, TAG, VAL) |
| 1218 | |
| 1219 | if (bfd_link_executable (info)) |
| 1220 | { |
| 1221 | if (!add_dynamic_entry (DT_DEBUG, 0)) |
| 1222 | return FALSE; |
| 1223 | } |
| 1224 | |
| 1225 | if (htab->elf.splt->size != 0) |
| 1226 | { |
| 1227 | /* DT_PLTGOT is used by prelink even if there is no PLT |
| 1228 | relocation. */ |
| 1229 | if (!add_dynamic_entry (DT_PLTGOT, 0)) |
| 1230 | return FALSE; |
| 1231 | } |
| 1232 | |
| 1233 | if (htab->elf.srelplt->size != 0) |
| 1234 | { |
| 1235 | if (!add_dynamic_entry (DT_PLTRELSZ, 0) |
| 1236 | || !add_dynamic_entry (DT_PLTREL, htab->dt_reloc) |
| 1237 | || !add_dynamic_entry (DT_JMPREL, 0)) |
| 1238 | return FALSE; |
| 1239 | } |
| 1240 | |
| 1241 | if (htab->tlsdesc_plt |
| 1242 | && (!add_dynamic_entry (DT_TLSDESC_PLT, 0) |
| 1243 | || !add_dynamic_entry (DT_TLSDESC_GOT, 0))) |
| 1244 | return FALSE; |
| 1245 | |
| 1246 | if (relocs) |
| 1247 | { |
| 1248 | if (!add_dynamic_entry (htab->dt_reloc, 0) |
| 1249 | || !add_dynamic_entry (htab->dt_reloc_sz, 0) |
| 1250 | || !add_dynamic_entry (htab->dt_reloc_ent, |
| 1251 | htab->sizeof_reloc)) |
| 1252 | return FALSE; |
| 1253 | |
| 1254 | /* If any dynamic relocs apply to a read-only section, |
| 1255 | then we need a DT_TEXTREL entry. */ |
| 1256 | if ((info->flags & DF_TEXTREL) == 0) |
| 1257 | elf_link_hash_traverse (&htab->elf, |
| 1258 | _bfd_x86_elf_readonly_dynrelocs, |
| 1259 | info); |
| 1260 | |
| 1261 | if ((info->flags & DF_TEXTREL) != 0) |
| 1262 | { |
| 1263 | if (htab->readonly_dynrelocs_against_ifunc) |
| 1264 | { |
| 1265 | info->callbacks->einfo |
| 1266 | (_("%P%X: read-only segment has dynamic IFUNC relocations; recompile with -fPIC\n")); |
| 1267 | bfd_set_error (bfd_error_bad_value); |
| 1268 | return FALSE; |
| 1269 | } |
| 1270 | |
| 1271 | if (!add_dynamic_entry (DT_TEXTREL, 0)) |
| 1272 | return FALSE; |
| 1273 | } |
| 1274 | } |
| 1275 | if (htab->is_vxworks |
| 1276 | && !elf_vxworks_add_dynamic_entries (output_bfd, info)) |
| 1277 | return FALSE; |
| 1278 | } |
| 1279 | #undef add_dynamic_entry |
| 1280 | |
| 1281 | return TRUE; |
| 1282 | } |
| 1283 | |
| 1284 | bfd_boolean |
| 1285 | _bfd_x86_elf_always_size_sections (bfd *output_bfd, |
| 1286 | struct bfd_link_info *info) |
| 1287 | { |
| 1288 | asection *tls_sec = elf_hash_table (info)->tls_sec; |
| 1289 | |
| 1290 | if (tls_sec) |
| 1291 | { |
| 1292 | struct elf_link_hash_entry *tlsbase; |
| 1293 | |
| 1294 | tlsbase = elf_link_hash_lookup (elf_hash_table (info), |
| 1295 | "_TLS_MODULE_BASE_", |
| 1296 | FALSE, FALSE, FALSE); |
| 1297 | |
| 1298 | if (tlsbase && tlsbase->type == STT_TLS) |
| 1299 | { |
| 1300 | struct elf_x86_link_hash_table *htab; |
| 1301 | struct bfd_link_hash_entry *bh = NULL; |
| 1302 | const struct elf_backend_data *bed |
| 1303 | = get_elf_backend_data (output_bfd); |
| 1304 | |
| 1305 | htab = elf_x86_hash_table (info, bed->target_id); |
| 1306 | if (htab == NULL) |
| 1307 | return FALSE; |
| 1308 | |
| 1309 | if (!(_bfd_generic_link_add_one_symbol |
| 1310 | (info, output_bfd, "_TLS_MODULE_BASE_", BSF_LOCAL, |
| 1311 | tls_sec, 0, NULL, FALSE, |
| 1312 | bed->collect, &bh))) |
| 1313 | return FALSE; |
| 1314 | |
| 1315 | htab->tls_module_base = bh; |
| 1316 | |
| 1317 | tlsbase = (struct elf_link_hash_entry *)bh; |
| 1318 | tlsbase->def_regular = 1; |
| 1319 | tlsbase->other = STV_HIDDEN; |
| 1320 | tlsbase->root.linker_def = 1; |
| 1321 | (*bed->elf_backend_hide_symbol) (info, tlsbase, TRUE); |
| 1322 | } |
| 1323 | } |
| 1324 | |
| 1325 | return TRUE; |
| 1326 | } |
| 1327 | |
| 1328 | void |
| 1329 | _bfd_x86_elf_merge_symbol_attribute (struct elf_link_hash_entry *h, |
| 1330 | const Elf_Internal_Sym *isym, |
| 1331 | bfd_boolean definition, |
| 1332 | bfd_boolean dynamic ATTRIBUTE_UNUSED) |
| 1333 | { |
| 1334 | if (definition) |
| 1335 | { |
| 1336 | struct elf_x86_link_hash_entry *eh |
| 1337 | = (struct elf_x86_link_hash_entry *) h; |
| 1338 | eh->def_protected = (ELF_ST_VISIBILITY (isym->st_other) |
| 1339 | == STV_PROTECTED); |
| 1340 | } |
| 1341 | } |
| 1342 | |
| 1343 | /* Copy the extra info we tack onto an elf_link_hash_entry. */ |
| 1344 | |
| 1345 | void |
| 1346 | _bfd_x86_elf_copy_indirect_symbol (struct bfd_link_info *info, |
| 1347 | struct elf_link_hash_entry *dir, |
| 1348 | struct elf_link_hash_entry *ind) |
| 1349 | { |
| 1350 | struct elf_x86_link_hash_entry *edir, *eind; |
| 1351 | |
| 1352 | edir = (struct elf_x86_link_hash_entry *) dir; |
| 1353 | eind = (struct elf_x86_link_hash_entry *) ind; |
| 1354 | |
| 1355 | if (eind->dyn_relocs != NULL) |
| 1356 | { |
| 1357 | if (edir->dyn_relocs != NULL) |
| 1358 | { |
| 1359 | struct elf_dyn_relocs **pp; |
| 1360 | struct elf_dyn_relocs *p; |
| 1361 | |
| 1362 | /* Add reloc counts against the indirect sym to the direct sym |
| 1363 | list. Merge any entries against the same section. */ |
| 1364 | for (pp = &eind->dyn_relocs; (p = *pp) != NULL; ) |
| 1365 | { |
| 1366 | struct elf_dyn_relocs *q; |
| 1367 | |
| 1368 | for (q = edir->dyn_relocs; q != NULL; q = q->next) |
| 1369 | if (q->sec == p->sec) |
| 1370 | { |
| 1371 | q->pc_count += p->pc_count; |
| 1372 | q->count += p->count; |
| 1373 | *pp = p->next; |
| 1374 | break; |
| 1375 | } |
| 1376 | if (q == NULL) |
| 1377 | pp = &p->next; |
| 1378 | } |
| 1379 | *pp = edir->dyn_relocs; |
| 1380 | } |
| 1381 | |
| 1382 | edir->dyn_relocs = eind->dyn_relocs; |
| 1383 | eind->dyn_relocs = NULL; |
| 1384 | } |
| 1385 | |
| 1386 | if (ind->root.type == bfd_link_hash_indirect |
| 1387 | && dir->got.refcount <= 0) |
| 1388 | { |
| 1389 | edir->tls_type = eind->tls_type; |
| 1390 | eind->tls_type = GOT_UNKNOWN; |
| 1391 | } |
| 1392 | |
| 1393 | /* Copy gotoff_ref so that elf_i386_adjust_dynamic_symbol will |
| 1394 | generate a R_386_COPY reloc. */ |
| 1395 | edir->gotoff_ref |= eind->gotoff_ref; |
| 1396 | |
| 1397 | edir->has_got_reloc |= eind->has_got_reloc; |
| 1398 | edir->has_non_got_reloc |= eind->has_non_got_reloc; |
| 1399 | |
| 1400 | if (ELIMINATE_COPY_RELOCS |
| 1401 | && ind->root.type != bfd_link_hash_indirect |
| 1402 | && dir->dynamic_adjusted) |
| 1403 | { |
| 1404 | /* If called to transfer flags for a weakdef during processing |
| 1405 | of elf_adjust_dynamic_symbol, don't copy non_got_ref. |
| 1406 | We clear it ourselves for ELIMINATE_COPY_RELOCS. */ |
| 1407 | if (dir->versioned != versioned_hidden) |
| 1408 | dir->ref_dynamic |= ind->ref_dynamic; |
| 1409 | dir->ref_regular |= ind->ref_regular; |
| 1410 | dir->ref_regular_nonweak |= ind->ref_regular_nonweak; |
| 1411 | dir->needs_plt |= ind->needs_plt; |
| 1412 | dir->pointer_equality_needed |= ind->pointer_equality_needed; |
| 1413 | } |
| 1414 | else |
| 1415 | { |
| 1416 | if (eind->func_pointer_refcount > 0) |
| 1417 | { |
| 1418 | edir->func_pointer_refcount += eind->func_pointer_refcount; |
| 1419 | eind->func_pointer_refcount = 0; |
| 1420 | } |
| 1421 | |
| 1422 | _bfd_elf_link_hash_copy_indirect (info, dir, ind); |
| 1423 | } |
| 1424 | } |
| 1425 | |
| 1426 | /* Remove undefined weak symbol from the dynamic symbol table if it |
| 1427 | is resolved to 0. */ |
| 1428 | |
| 1429 | bfd_boolean |
| 1430 | _bfd_x86_elf_fixup_symbol (struct bfd_link_info *info, |
| 1431 | struct elf_link_hash_entry *h) |
| 1432 | { |
| 1433 | if (h->dynindx != -1) |
| 1434 | { |
| 1435 | const struct elf_backend_data *bed |
| 1436 | = get_elf_backend_data (info->output_bfd); |
| 1437 | if (UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, |
| 1438 | bed->target_id, |
| 1439 | elf_x86_hash_entry (h)->has_got_reloc, |
| 1440 | elf_x86_hash_entry (h))) |
| 1441 | { |
| 1442 | h->dynindx = -1; |
| 1443 | _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr, |
| 1444 | h->dynstr_index); |
| 1445 | } |
| 1446 | } |
| 1447 | return TRUE; |
| 1448 | } |
| 1449 | |
| 1450 | /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */ |
| 1451 | |
| 1452 | bfd_boolean |
| 1453 | _bfd_x86_elf_hash_symbol (struct elf_link_hash_entry *h) |
| 1454 | { |
| 1455 | if (h->plt.offset != (bfd_vma) -1 |
| 1456 | && !h->def_regular |
| 1457 | && !h->pointer_equality_needed) |
| 1458 | return FALSE; |
| 1459 | |
| 1460 | return _bfd_elf_hash_symbol (h); |
| 1461 | } |
| 1462 | |
| 1463 | /* Adjust a symbol defined by a dynamic object and referenced by a |
| 1464 | regular object. The current definition is in some section of the |
| 1465 | dynamic object, but we're not including those sections. We have to |
| 1466 | change the definition to something the rest of the link can |
| 1467 | understand. */ |
| 1468 | |
| 1469 | bfd_boolean |
| 1470 | _bfd_x86_elf_adjust_dynamic_symbol (struct bfd_link_info *info, |
| 1471 | struct elf_link_hash_entry *h) |
| 1472 | { |
| 1473 | struct elf_x86_link_hash_table *htab; |
| 1474 | asection *s, *srel; |
| 1475 | struct elf_x86_link_hash_entry *eh; |
| 1476 | struct elf_dyn_relocs *p; |
| 1477 | const struct elf_backend_data *bed |
| 1478 | = get_elf_backend_data (info->output_bfd); |
| 1479 | |
| 1480 | /* STT_GNU_IFUNC symbol must go through PLT. */ |
| 1481 | if (h->type == STT_GNU_IFUNC) |
| 1482 | { |
| 1483 | /* All local STT_GNU_IFUNC references must be treate as local |
| 1484 | calls via local PLT. */ |
| 1485 | if (h->ref_regular |
| 1486 | && SYMBOL_CALLS_LOCAL (info, h)) |
| 1487 | { |
| 1488 | bfd_size_type pc_count = 0, count = 0; |
| 1489 | struct elf_dyn_relocs **pp; |
| 1490 | |
| 1491 | eh = (struct elf_x86_link_hash_entry *) h; |
| 1492 | for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) |
| 1493 | { |
| 1494 | pc_count += p->pc_count; |
| 1495 | p->count -= p->pc_count; |
| 1496 | p->pc_count = 0; |
| 1497 | count += p->count; |
| 1498 | if (p->count == 0) |
| 1499 | *pp = p->next; |
| 1500 | else |
| 1501 | pp = &p->next; |
| 1502 | } |
| 1503 | |
| 1504 | if (pc_count || count) |
| 1505 | { |
| 1506 | h->non_got_ref = 1; |
| 1507 | if (pc_count) |
| 1508 | { |
| 1509 | /* Increment PLT reference count only for PC-relative |
| 1510 | references. */ |
| 1511 | h->needs_plt = 1; |
| 1512 | if (h->plt.refcount <= 0) |
| 1513 | h->plt.refcount = 1; |
| 1514 | else |
| 1515 | h->plt.refcount += 1; |
| 1516 | } |
| 1517 | } |
| 1518 | } |
| 1519 | |
| 1520 | if (h->plt.refcount <= 0) |
| 1521 | { |
| 1522 | h->plt.offset = (bfd_vma) -1; |
| 1523 | h->needs_plt = 0; |
| 1524 | } |
| 1525 | return TRUE; |
| 1526 | } |
| 1527 | |
| 1528 | /* If this is a function, put it in the procedure linkage table. We |
| 1529 | will fill in the contents of the procedure linkage table later, |
| 1530 | when we know the address of the .got section. */ |
| 1531 | if (h->type == STT_FUNC |
| 1532 | || h->needs_plt) |
| 1533 | { |
| 1534 | if (h->plt.refcount <= 0 |
| 1535 | || SYMBOL_CALLS_LOCAL (info, h) |
| 1536 | || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT |
| 1537 | && h->root.type == bfd_link_hash_undefweak)) |
| 1538 | { |
| 1539 | /* This case can occur if we saw a PLT32 reloc in an input |
| 1540 | file, but the symbol was never referred to by a dynamic |
| 1541 | object, or if all references were garbage collected. In |
| 1542 | such a case, we don't actually need to build a procedure |
| 1543 | linkage table, and we can just do a PC32 reloc instead. */ |
| 1544 | h->plt.offset = (bfd_vma) -1; |
| 1545 | h->needs_plt = 0; |
| 1546 | } |
| 1547 | |
| 1548 | return TRUE; |
| 1549 | } |
| 1550 | else |
| 1551 | /* It's possible that we incorrectly decided a .plt reloc was needed |
| 1552 | * for an R_386_PC32/R_X86_64_PC32 reloc to a non-function sym in |
| 1553 | check_relocs. We can't decide accurately between function and |
| 1554 | non-function syms in check-relocs; Objects loaded later in |
| 1555 | the link may change h->type. So fix it now. */ |
| 1556 | h->plt.offset = (bfd_vma) -1; |
| 1557 | |
| 1558 | eh = (struct elf_x86_link_hash_entry *) h; |
| 1559 | |
| 1560 | /* If this is a weak symbol, and there is a real definition, the |
| 1561 | processor independent code will have arranged for us to see the |
| 1562 | real definition first, and we can just use the same value. */ |
| 1563 | if (h->u.weakdef != NULL) |
| 1564 | { |
| 1565 | BFD_ASSERT (h->u.weakdef->root.type == bfd_link_hash_defined |
| 1566 | || h->u.weakdef->root.type == bfd_link_hash_defweak); |
| 1567 | h->root.u.def.section = h->u.weakdef->root.u.def.section; |
| 1568 | h->root.u.def.value = h->u.weakdef->root.u.def.value; |
| 1569 | if (ELIMINATE_COPY_RELOCS |
| 1570 | || info->nocopyreloc |
| 1571 | || SYMBOL_NO_COPYRELOC (info, eh)) |
| 1572 | { |
| 1573 | /* NB: needs_copy is always 0 for i386. */ |
| 1574 | h->non_got_ref = h->u.weakdef->non_got_ref; |
| 1575 | eh->needs_copy = h->u.weakdef->needs_copy; |
| 1576 | } |
| 1577 | return TRUE; |
| 1578 | } |
| 1579 | |
| 1580 | /* This is a reference to a symbol defined by a dynamic object which |
| 1581 | is not a function. */ |
| 1582 | |
| 1583 | /* If we are creating a shared library, we must presume that the |
| 1584 | only references to the symbol are via the global offset table. |
| 1585 | For such cases we need not do anything here; the relocations will |
| 1586 | be handled correctly by relocate_section. */ |
| 1587 | if (!bfd_link_executable (info)) |
| 1588 | return TRUE; |
| 1589 | |
| 1590 | /* If there are no references to this symbol that do not use the |
| 1591 | GOT nor R_386_GOTOFF relocation, we don't need to generate a copy |
| 1592 | reloc. NB: gotoff_ref is always 0 for x86-64. */ |
| 1593 | if (!h->non_got_ref && !eh->gotoff_ref) |
| 1594 | return TRUE; |
| 1595 | |
| 1596 | /* If -z nocopyreloc was given, we won't generate them either. */ |
| 1597 | if (info->nocopyreloc || SYMBOL_NO_COPYRELOC (info, eh)) |
| 1598 | { |
| 1599 | h->non_got_ref = 0; |
| 1600 | return TRUE; |
| 1601 | } |
| 1602 | |
| 1603 | htab = elf_x86_hash_table (info, bed->target_id); |
| 1604 | if (htab == NULL) |
| 1605 | return FALSE; |
| 1606 | |
| 1607 | /* If there aren't any dynamic relocs in read-only sections nor |
| 1608 | R_386_GOTOFF relocation, then we can keep the dynamic relocs and |
| 1609 | avoid the copy reloc. This doesn't work on VxWorks, where we can |
| 1610 | not have dynamic relocations (other than copy and jump slot |
| 1611 | relocations) in an executable. */ |
| 1612 | if (ELIMINATE_COPY_RELOCS |
| 1613 | && (bed->target_id == X86_64_ELF_DATA |
| 1614 | || (!eh->gotoff_ref |
| 1615 | && !htab->is_vxworks))) |
| 1616 | { |
| 1617 | for (p = eh->dyn_relocs; p != NULL; p = p->next) |
| 1618 | { |
| 1619 | s = p->sec->output_section; |
| 1620 | if (s != NULL && (s->flags & SEC_READONLY) != 0) |
| 1621 | break; |
| 1622 | } |
| 1623 | |
| 1624 | /* If we didn't find any dynamic relocs in read-only sections, |
| 1625 | then we'll be keeping the dynamic relocs and avoiding the copy |
| 1626 | reloc. */ |
| 1627 | if (p == NULL) |
| 1628 | { |
| 1629 | h->non_got_ref = 0; |
| 1630 | return TRUE; |
| 1631 | } |
| 1632 | } |
| 1633 | |
| 1634 | /* We must allocate the symbol in our .dynbss section, which will |
| 1635 | become part of the .bss section of the executable. There will be |
| 1636 | an entry for this symbol in the .dynsym section. The dynamic |
| 1637 | object will contain position independent code, so all references |
| 1638 | from the dynamic object to this symbol will go through the global |
| 1639 | offset table. The dynamic linker will use the .dynsym entry to |
| 1640 | determine the address it must put in the global offset table, so |
| 1641 | both the dynamic object and the regular object will refer to the |
| 1642 | same memory location for the variable. */ |
| 1643 | |
| 1644 | /* We must generate a R_386_COPY/R_X86_64_COPY reloc to tell the |
| 1645 | dynamic linker to copy the initial value out of the dynamic object |
| 1646 | and into the runtime process image. */ |
| 1647 | if ((h->root.u.def.section->flags & SEC_READONLY) != 0) |
| 1648 | { |
| 1649 | s = htab->elf.sdynrelro; |
| 1650 | srel = htab->elf.sreldynrelro; |
| 1651 | } |
| 1652 | else |
| 1653 | { |
| 1654 | s = htab->elf.sdynbss; |
| 1655 | srel = htab->elf.srelbss; |
| 1656 | } |
| 1657 | if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0) |
| 1658 | { |
| 1659 | srel->size += htab->sizeof_reloc; |
| 1660 | h->needs_copy = 1; |
| 1661 | } |
| 1662 | |
| 1663 | return _bfd_elf_adjust_dynamic_copy (info, h, s); |
| 1664 | } |
| 1665 | |
| 1666 | /* Return TRUE if a symbol is referenced locally. It is similar to |
| 1667 | SYMBOL_REFERENCES_LOCAL, but it also checks version script. It |
| 1668 | works in check_relocs. */ |
| 1669 | |
| 1670 | bfd_boolean |
| 1671 | _bfd_x86_elf_link_symbol_references_local (struct bfd_link_info *info, |
| 1672 | struct elf_link_hash_entry *h) |
| 1673 | { |
| 1674 | struct elf_x86_link_hash_entry *eh |
| 1675 | = (struct elf_x86_link_hash_entry *) h; |
| 1676 | |
| 1677 | if (eh->local_ref > 1) |
| 1678 | return TRUE; |
| 1679 | |
| 1680 | if (eh->local_ref == 1) |
| 1681 | return FALSE; |
| 1682 | |
| 1683 | /* Unversioned symbols defined in regular objects can be forced local |
| 1684 | by linker version script. A weak undefined symbol can fored local |
| 1685 | if it has non-default visibility or "-z nodynamic-undefined-weak" |
| 1686 | is used. */ |
| 1687 | if (SYMBOL_REFERENCES_LOCAL (info, h) |
| 1688 | || ((ELF_ST_VISIBILITY (h->other) != STV_DEFAULT |
| 1689 | || info->dynamic_undefined_weak == 0) |
| 1690 | && h->root.type == bfd_link_hash_undefweak) |
| 1691 | || ((h->def_regular || ELF_COMMON_DEF_P (h)) |
| 1692 | && h->versioned == unversioned |
| 1693 | && info->version_info != NULL |
| 1694 | && bfd_hide_sym_by_version (info->version_info, |
| 1695 | h->root.root.string))) |
| 1696 | { |
| 1697 | eh->local_ref = 2; |
| 1698 | return TRUE; |
| 1699 | } |
| 1700 | |
| 1701 | eh->local_ref = 1; |
| 1702 | return FALSE; |
| 1703 | } |
| 1704 | |
| 1705 | /* Return the section that should be marked against GC for a given |
| 1706 | relocation. */ |
| 1707 | |
| 1708 | asection * |
| 1709 | _bfd_x86_elf_gc_mark_hook (asection *sec, |
| 1710 | struct bfd_link_info *info, |
| 1711 | Elf_Internal_Rela *rel, |
| 1712 | struct elf_link_hash_entry *h, |
| 1713 | Elf_Internal_Sym *sym) |
| 1714 | { |
| 1715 | /* Compiler should optimize this out. */ |
| 1716 | if (((unsigned int) R_X86_64_GNU_VTINHERIT |
| 1717 | != (unsigned int) R_386_GNU_VTINHERIT) |
| 1718 | || ((unsigned int) R_X86_64_GNU_VTENTRY |
| 1719 | != (unsigned int) R_386_GNU_VTENTRY)) |
| 1720 | abort (); |
| 1721 | |
| 1722 | if (h != NULL) |
| 1723 | switch (ELF32_R_TYPE (rel->r_info)) |
| 1724 | { |
| 1725 | case R_X86_64_GNU_VTINHERIT: |
| 1726 | case R_X86_64_GNU_VTENTRY: |
| 1727 | return NULL; |
| 1728 | } |
| 1729 | |
| 1730 | return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym); |
| 1731 | } |
| 1732 | |
| 1733 | static bfd_vma |
| 1734 | elf_i386_get_plt_got_vma (struct elf_x86_plt *plt_p ATTRIBUTE_UNUSED, |
| 1735 | bfd_vma off, |
| 1736 | bfd_vma offset ATTRIBUTE_UNUSED, |
| 1737 | bfd_vma got_addr) |
| 1738 | { |
| 1739 | return got_addr + off; |
| 1740 | } |
| 1741 | |
| 1742 | static bfd_vma |
| 1743 | elf_x86_64_get_plt_got_vma (struct elf_x86_plt *plt_p, |
| 1744 | bfd_vma off, |
| 1745 | bfd_vma offset, |
| 1746 | bfd_vma got_addr ATTRIBUTE_UNUSED) |
| 1747 | { |
| 1748 | return plt_p->sec->vma + offset + off + plt_p->plt_got_insn_size; |
| 1749 | } |
| 1750 | |
| 1751 | static bfd_boolean |
| 1752 | elf_i386_valid_plt_reloc_p (unsigned int type) |
| 1753 | { |
| 1754 | return (type == R_386_JUMP_SLOT |
| 1755 | || type == R_386_GLOB_DAT |
| 1756 | || type == R_386_IRELATIVE); |
| 1757 | } |
| 1758 | |
| 1759 | static bfd_boolean |
| 1760 | elf_x86_64_valid_plt_reloc_p (unsigned int type) |
| 1761 | { |
| 1762 | return (type == R_X86_64_JUMP_SLOT |
| 1763 | || type == R_X86_64_GLOB_DAT |
| 1764 | || type == R_X86_64_IRELATIVE); |
| 1765 | } |
| 1766 | |
| 1767 | long |
| 1768 | _bfd_x86_elf_get_synthetic_symtab (bfd *abfd, |
| 1769 | long count, |
| 1770 | long relsize, |
| 1771 | bfd_vma got_addr, |
| 1772 | struct elf_x86_plt plts[], |
| 1773 | asymbol **dynsyms, |
| 1774 | asymbol **ret) |
| 1775 | { |
| 1776 | long size, i, n, len; |
| 1777 | int j; |
| 1778 | unsigned int plt_got_offset, plt_entry_size; |
| 1779 | asymbol *s; |
| 1780 | bfd_byte *plt_contents; |
| 1781 | long dynrelcount; |
| 1782 | arelent **dynrelbuf, *p; |
| 1783 | char *names; |
| 1784 | const struct elf_backend_data *bed; |
| 1785 | bfd_vma (*get_plt_got_vma) (struct elf_x86_plt *, bfd_vma, bfd_vma, |
| 1786 | bfd_vma); |
| 1787 | bfd_boolean (*valid_plt_reloc_p) (unsigned int); |
| 1788 | |
| 1789 | if (count == 0) |
| 1790 | return -1; |
| 1791 | |
| 1792 | dynrelbuf = (arelent **) bfd_malloc (relsize); |
| 1793 | if (dynrelbuf == NULL) |
| 1794 | return -1; |
| 1795 | |
| 1796 | dynrelcount = bfd_canonicalize_dynamic_reloc (abfd, dynrelbuf, |
| 1797 | dynsyms); |
| 1798 | |
| 1799 | /* Sort the relocs by address. */ |
| 1800 | qsort (dynrelbuf, dynrelcount, sizeof (arelent *), |
| 1801 | _bfd_x86_elf_compare_relocs); |
| 1802 | |
| 1803 | size = count * sizeof (asymbol); |
| 1804 | |
| 1805 | /* Allocate space for @plt suffixes. */ |
| 1806 | n = 0; |
| 1807 | for (i = 0; i < dynrelcount; i++) |
| 1808 | { |
| 1809 | p = dynrelbuf[i]; |
| 1810 | size += strlen ((*p->sym_ptr_ptr)->name) + sizeof ("@plt"); |
| 1811 | if (p->addend != 0) |
| 1812 | size += sizeof ("+0x") - 1 + 8 + 8 * ABI_64_P (abfd); |
| 1813 | } |
| 1814 | |
| 1815 | s = *ret = (asymbol *) bfd_zmalloc (size); |
| 1816 | if (s == NULL) |
| 1817 | goto bad_return; |
| 1818 | |
| 1819 | bed = get_elf_backend_data (abfd); |
| 1820 | |
| 1821 | if (bed->target_id == X86_64_ELF_DATA) |
| 1822 | { |
| 1823 | get_plt_got_vma = elf_x86_64_get_plt_got_vma; |
| 1824 | valid_plt_reloc_p = elf_x86_64_valid_plt_reloc_p; |
| 1825 | } |
| 1826 | else |
| 1827 | { |
| 1828 | get_plt_got_vma = elf_i386_get_plt_got_vma; |
| 1829 | valid_plt_reloc_p = elf_i386_valid_plt_reloc_p; |
| 1830 | if (got_addr) |
| 1831 | { |
| 1832 | /* Check .got.plt and then .got to get the _GLOBAL_OFFSET_TABLE_ |
| 1833 | address. */ |
| 1834 | asection *sec = bfd_get_section_by_name (abfd, ".got.plt"); |
| 1835 | if (sec != NULL) |
| 1836 | got_addr = sec->vma; |
| 1837 | else |
| 1838 | { |
| 1839 | sec = bfd_get_section_by_name (abfd, ".got"); |
| 1840 | if (sec != NULL) |
| 1841 | got_addr = sec->vma; |
| 1842 | } |
| 1843 | |
| 1844 | if (got_addr == (bfd_vma) -1) |
| 1845 | goto bad_return; |
| 1846 | } |
| 1847 | } |
| 1848 | |
| 1849 | /* Check for each PLT section. */ |
| 1850 | names = (char *) (s + count); |
| 1851 | size = 0; |
| 1852 | n = 0; |
| 1853 | for (j = 0; plts[j].name != NULL; j++) |
| 1854 | if ((plt_contents = plts[j].contents) != NULL) |
| 1855 | { |
| 1856 | long k; |
| 1857 | bfd_vma offset; |
| 1858 | asection *plt; |
| 1859 | struct elf_x86_plt *plt_p = &plts[j]; |
| 1860 | |
| 1861 | plt_got_offset = plt_p->plt_got_offset; |
| 1862 | plt_entry_size = plt_p->plt_entry_size; |
| 1863 | |
| 1864 | plt = plt_p->sec; |
| 1865 | |
| 1866 | if ((plt_p->type & plt_lazy)) |
| 1867 | { |
| 1868 | /* Skip PLT0 in lazy PLT. */ |
| 1869 | k = 1; |
| 1870 | offset = plt_entry_size; |
| 1871 | } |
| 1872 | else |
| 1873 | { |
| 1874 | k = 0; |
| 1875 | offset = 0; |
| 1876 | } |
| 1877 | |
| 1878 | /* Check each PLT entry against dynamic relocations. */ |
| 1879 | for (; k < plt_p->count; k++) |
| 1880 | { |
| 1881 | int off; |
| 1882 | bfd_vma got_vma; |
| 1883 | long min, max, mid; |
| 1884 | |
| 1885 | /* Get the GOT offset for i386 or the PC-relative offset |
| 1886 | for x86-64, a signed 32-bit integer. */ |
| 1887 | off = H_GET_32 (abfd, (plt_contents + offset |
| 1888 | + plt_got_offset)); |
| 1889 | got_vma = get_plt_got_vma (plt_p, off, offset, got_addr); |
| 1890 | |
| 1891 | /* Binary search. */ |
| 1892 | p = dynrelbuf[0]; |
| 1893 | min = 0; |
| 1894 | max = dynrelcount; |
| 1895 | while ((min + 1) < max) |
| 1896 | { |
| 1897 | arelent *r; |
| 1898 | |
| 1899 | mid = (min + max) / 2; |
| 1900 | r = dynrelbuf[mid]; |
| 1901 | if (got_vma > r->address) |
| 1902 | min = mid; |
| 1903 | else if (got_vma < r->address) |
| 1904 | max = mid; |
| 1905 | else |
| 1906 | { |
| 1907 | p = r; |
| 1908 | break; |
| 1909 | } |
| 1910 | } |
| 1911 | |
| 1912 | /* Skip unknown relocation. PR 17512: file: bc9d6cf5. */ |
| 1913 | if (got_vma == p->address |
| 1914 | && p->howto != NULL |
| 1915 | && valid_plt_reloc_p (p->howto->type)) |
| 1916 | { |
| 1917 | *s = **p->sym_ptr_ptr; |
| 1918 | /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL |
| 1919 | set. Since we are defining a symbol, ensure one |
| 1920 | of them is set. */ |
| 1921 | if ((s->flags & BSF_LOCAL) == 0) |
| 1922 | s->flags |= BSF_GLOBAL; |
| 1923 | s->flags |= BSF_SYNTHETIC; |
| 1924 | /* This is no longer a section symbol. */ |
| 1925 | s->flags &= ~BSF_SECTION_SYM; |
| 1926 | s->section = plt; |
| 1927 | s->the_bfd = plt->owner; |
| 1928 | s->value = offset; |
| 1929 | s->udata.p = NULL; |
| 1930 | s->name = names; |
| 1931 | len = strlen ((*p->sym_ptr_ptr)->name); |
| 1932 | memcpy (names, (*p->sym_ptr_ptr)->name, len); |
| 1933 | names += len; |
| 1934 | if (p->addend != 0) |
| 1935 | { |
| 1936 | char buf[30], *a; |
| 1937 | |
| 1938 | memcpy (names, "+0x", sizeof ("+0x") - 1); |
| 1939 | names += sizeof ("+0x") - 1; |
| 1940 | bfd_sprintf_vma (abfd, buf, p->addend); |
| 1941 | for (a = buf; *a == '0'; ++a) |
| 1942 | ; |
| 1943 | size = strlen (a); |
| 1944 | memcpy (names, a, size); |
| 1945 | names += size; |
| 1946 | } |
| 1947 | memcpy (names, "@plt", sizeof ("@plt")); |
| 1948 | names += sizeof ("@plt"); |
| 1949 | n++; |
| 1950 | s++; |
| 1951 | } |
| 1952 | offset += plt_entry_size; |
| 1953 | } |
| 1954 | } |
| 1955 | |
| 1956 | /* PLT entries with R_386_TLS_DESC relocations are skipped. */ |
| 1957 | if (n == 0) |
| 1958 | { |
| 1959 | bad_return: |
| 1960 | count = -1; |
| 1961 | } |
| 1962 | else |
| 1963 | count = n; |
| 1964 | |
| 1965 | for (j = 0; plts[j].name != NULL; j++) |
| 1966 | if (plts[j].contents != NULL) |
| 1967 | free (plts[j].contents); |
| 1968 | |
| 1969 | free (dynrelbuf); |
| 1970 | |
| 1971 | return count; |
| 1972 | } |
| 1973 | |
| 1974 | /* Parse x86 GNU properties. */ |
| 1975 | |
| 1976 | enum elf_property_kind |
| 1977 | _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type, |
| 1978 | bfd_byte *ptr, unsigned int datasz) |
| 1979 | { |
| 1980 | elf_property *prop; |
| 1981 | |
| 1982 | switch (type) |
| 1983 | { |
| 1984 | case GNU_PROPERTY_X86_ISA_1_USED: |
| 1985 | case GNU_PROPERTY_X86_ISA_1_NEEDED: |
| 1986 | case GNU_PROPERTY_X86_FEATURE_1_AND: |
| 1987 | if (datasz != 4) |
| 1988 | { |
| 1989 | _bfd_error_handler |
| 1990 | ((type == GNU_PROPERTY_X86_ISA_1_USED |
| 1991 | ? _("error: %B: <corrupt x86 ISA used size: 0x%x>") |
| 1992 | : (type == GNU_PROPERTY_X86_ISA_1_NEEDED |
| 1993 | ? _("error: %B: <corrupt x86 ISA needed size: 0x%x>") |
| 1994 | : _("error: %B: <corrupt x86 feature size: 0x%x>"))), |
| 1995 | abfd, datasz); |
| 1996 | return property_corrupt; |
| 1997 | } |
| 1998 | prop = _bfd_elf_get_property (abfd, type, datasz); |
| 1999 | /* Combine properties of the same type. */ |
| 2000 | prop->u.number |= bfd_h_get_32 (abfd, ptr); |
| 2001 | prop->pr_kind = property_number; |
| 2002 | break; |
| 2003 | |
| 2004 | default: |
| 2005 | return property_ignored; |
| 2006 | } |
| 2007 | |
| 2008 | return property_number; |
| 2009 | } |
| 2010 | |
| 2011 | /* Merge x86 GNU property BPROP with APROP. If APROP isn't NULL, |
| 2012 | return TRUE if APROP is updated. Otherwise, return TRUE if BPROP |
| 2013 | should be merged with ABFD. */ |
| 2014 | |
| 2015 | bfd_boolean |
| 2016 | _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info, |
| 2017 | bfd *abfd ATTRIBUTE_UNUSED, |
| 2018 | elf_property *aprop, |
| 2019 | elf_property *bprop) |
| 2020 | { |
| 2021 | unsigned int number, features; |
| 2022 | bfd_boolean updated = FALSE; |
| 2023 | unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type; |
| 2024 | |
| 2025 | switch (pr_type) |
| 2026 | { |
| 2027 | case GNU_PROPERTY_X86_ISA_1_USED: |
| 2028 | case GNU_PROPERTY_X86_ISA_1_NEEDED: |
| 2029 | if (aprop != NULL && bprop != NULL) |
| 2030 | { |
| 2031 | number = aprop->u.number; |
| 2032 | aprop->u.number = number | bprop->u.number; |
| 2033 | updated = number != (unsigned int) aprop->u.number; |
| 2034 | } |
| 2035 | else |
| 2036 | { |
| 2037 | /* Return TRUE if APROP is NULL to indicate that BPROP should |
| 2038 | be added to ABFD. */ |
| 2039 | updated = aprop == NULL; |
| 2040 | } |
| 2041 | break; |
| 2042 | |
| 2043 | case GNU_PROPERTY_X86_FEATURE_1_AND: |
| 2044 | /* Only one of APROP and BPROP can be NULL: |
| 2045 | 1. APROP & BPROP when both APROP and BPROP aren't NULL. |
| 2046 | 2. If APROP is NULL, remove x86 feature. |
| 2047 | 3. Otherwise, do nothing. |
| 2048 | */ |
| 2049 | if (aprop != NULL && bprop != NULL) |
| 2050 | { |
| 2051 | features = 0; |
| 2052 | if (info->ibt) |
| 2053 | features = GNU_PROPERTY_X86_FEATURE_1_IBT; |
| 2054 | if (info->shstk) |
| 2055 | features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK; |
| 2056 | number = aprop->u.number; |
| 2057 | /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and |
| 2058 | GNU_PROPERTY_X86_FEATURE_1_SHSTK. */ |
| 2059 | aprop->u.number = (number & bprop->u.number) | features; |
| 2060 | updated = number != (unsigned int) aprop->u.number; |
| 2061 | /* Remove the property if all feature bits are cleared. */ |
| 2062 | if (aprop->u.number == 0) |
| 2063 | aprop->pr_kind = property_remove; |
| 2064 | } |
| 2065 | else |
| 2066 | { |
| 2067 | features = 0; |
| 2068 | if (info->ibt) |
| 2069 | features = GNU_PROPERTY_X86_FEATURE_1_IBT; |
| 2070 | if (info->shstk) |
| 2071 | features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK; |
| 2072 | if (features) |
| 2073 | { |
| 2074 | /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and |
| 2075 | GNU_PROPERTY_X86_FEATURE_1_SHSTK. */ |
| 2076 | if (aprop != NULL) |
| 2077 | { |
| 2078 | number = aprop->u.number; |
| 2079 | aprop->u.number = number | features; |
| 2080 | updated = number != (unsigned int) aprop->u.number; |
| 2081 | } |
| 2082 | else |
| 2083 | { |
| 2084 | bprop->u.number |= features; |
| 2085 | updated = TRUE; |
| 2086 | } |
| 2087 | } |
| 2088 | else if (aprop != NULL) |
| 2089 | { |
| 2090 | aprop->pr_kind = property_remove; |
| 2091 | updated = TRUE; |
| 2092 | } |
| 2093 | } |
| 2094 | break; |
| 2095 | |
| 2096 | default: |
| 2097 | /* Never should happen. */ |
| 2098 | abort (); |
| 2099 | } |
| 2100 | |
| 2101 | return updated; |
| 2102 | } |
| 2103 | |
| 2104 | /* Set up x86 GNU properties. Return the first relocatable ELF input |
| 2105 | with GNU properties if found. Otherwise, return NULL. */ |
| 2106 | |
| 2107 | bfd * |
| 2108 | _bfd_x86_elf_link_setup_gnu_properties |
| 2109 | (struct bfd_link_info *info, |
| 2110 | struct elf_x86_plt_layout_table *plt_layout) |
| 2111 | { |
| 2112 | bfd_boolean normal_target; |
| 2113 | bfd_boolean lazy_plt; |
| 2114 | asection *sec, *pltsec; |
| 2115 | bfd *dynobj; |
| 2116 | bfd_boolean use_ibt_plt; |
| 2117 | unsigned int plt_alignment, features; |
| 2118 | struct elf_x86_link_hash_table *htab; |
| 2119 | bfd *pbfd; |
| 2120 | bfd *ebfd = NULL; |
| 2121 | elf_property *prop; |
| 2122 | const struct elf_backend_data *bed; |
| 2123 | unsigned int class_align = ABI_64_P (info->output_bfd) ? 3 : 2; |
| 2124 | unsigned int got_align; |
| 2125 | |
| 2126 | features = 0; |
| 2127 | if (info->ibt) |
| 2128 | features = GNU_PROPERTY_X86_FEATURE_1_IBT; |
| 2129 | if (info->shstk) |
| 2130 | features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK; |
| 2131 | |
| 2132 | /* Find a normal input file with GNU property note. */ |
| 2133 | for (pbfd = info->input_bfds; |
| 2134 | pbfd != NULL; |
| 2135 | pbfd = pbfd->link.next) |
| 2136 | if (bfd_get_flavour (pbfd) == bfd_target_elf_flavour |
| 2137 | && bfd_count_sections (pbfd) != 0) |
| 2138 | { |
| 2139 | ebfd = pbfd; |
| 2140 | |
| 2141 | if (elf_properties (pbfd) != NULL) |
| 2142 | break; |
| 2143 | } |
| 2144 | |
| 2145 | if (ebfd != NULL && features) |
| 2146 | { |
| 2147 | /* If features is set, add GNU_PROPERTY_X86_FEATURE_1_IBT and |
| 2148 | GNU_PROPERTY_X86_FEATURE_1_SHSTK. */ |
| 2149 | prop = _bfd_elf_get_property (ebfd, |
| 2150 | GNU_PROPERTY_X86_FEATURE_1_AND, |
| 2151 | 4); |
| 2152 | prop->u.number |= features; |
| 2153 | prop->pr_kind = property_number; |
| 2154 | |
| 2155 | /* Create the GNU property note section if needed. */ |
| 2156 | if (pbfd == NULL) |
| 2157 | { |
| 2158 | sec = bfd_make_section_with_flags (ebfd, |
| 2159 | NOTE_GNU_PROPERTY_SECTION_NAME, |
| 2160 | (SEC_ALLOC |
| 2161 | | SEC_LOAD |
| 2162 | | SEC_IN_MEMORY |
| 2163 | | SEC_READONLY |
| 2164 | | SEC_HAS_CONTENTS |
| 2165 | | SEC_DATA)); |
| 2166 | if (sec == NULL) |
| 2167 | info->callbacks->einfo (_("%F: failed to create GNU property section\n")); |
| 2168 | |
| 2169 | if (!bfd_set_section_alignment (ebfd, sec, class_align)) |
| 2170 | { |
| 2171 | error_alignment: |
| 2172 | info->callbacks->einfo (_("%F%A: failed to align section\n"), |
| 2173 | sec); |
| 2174 | } |
| 2175 | |
| 2176 | elf_section_type (sec) = SHT_NOTE; |
| 2177 | } |
| 2178 | } |
| 2179 | |
| 2180 | pbfd = _bfd_elf_link_setup_gnu_properties (info); |
| 2181 | |
| 2182 | bed = get_elf_backend_data (info->output_bfd); |
| 2183 | |
| 2184 | htab = elf_x86_hash_table (info, bed->target_id); |
| 2185 | if (htab == NULL) |
| 2186 | return pbfd; |
| 2187 | |
| 2188 | htab->is_vxworks = plt_layout->is_vxworks; |
| 2189 | htab->r_info = plt_layout->r_info; |
| 2190 | htab->r_sym = plt_layout->r_sym; |
| 2191 | |
| 2192 | if (bfd_link_relocatable (info)) |
| 2193 | return pbfd; |
| 2194 | |
| 2195 | use_ibt_plt = info->ibtplt || info->ibt; |
| 2196 | if (!use_ibt_plt && pbfd != NULL) |
| 2197 | { |
| 2198 | /* Check if GNU_PROPERTY_X86_FEATURE_1_IBT is on. */ |
| 2199 | elf_property_list *p; |
| 2200 | |
| 2201 | /* The property list is sorted in order of type. */ |
| 2202 | for (p = elf_properties (pbfd); p; p = p->next) |
| 2203 | { |
| 2204 | if (GNU_PROPERTY_X86_FEATURE_1_AND == p->property.pr_type) |
| 2205 | { |
| 2206 | use_ibt_plt = !!(p->property.u.number |
| 2207 | & GNU_PROPERTY_X86_FEATURE_1_IBT); |
| 2208 | break; |
| 2209 | } |
| 2210 | else if (GNU_PROPERTY_X86_FEATURE_1_AND < p->property.pr_type) |
| 2211 | break; |
| 2212 | } |
| 2213 | } |
| 2214 | |
| 2215 | dynobj = htab->elf.dynobj; |
| 2216 | |
| 2217 | /* Set htab->elf.dynobj here so that there is no need to check and |
| 2218 | set it in check_relocs. */ |
| 2219 | if (dynobj == NULL) |
| 2220 | { |
| 2221 | if (pbfd != NULL) |
| 2222 | { |
| 2223 | htab->elf.dynobj = pbfd; |
| 2224 | dynobj = pbfd; |
| 2225 | } |
| 2226 | else |
| 2227 | { |
| 2228 | bfd *abfd; |
| 2229 | |
| 2230 | /* Find a normal input file to hold linker created |
| 2231 | sections. */ |
| 2232 | for (abfd = info->input_bfds; |
| 2233 | abfd != NULL; |
| 2234 | abfd = abfd->link.next) |
| 2235 | if (bfd_get_flavour (abfd) == bfd_target_elf_flavour |
| 2236 | && (abfd->flags |
| 2237 | & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0) |
| 2238 | { |
| 2239 | htab->elf.dynobj = abfd; |
| 2240 | dynobj = abfd; |
| 2241 | break; |
| 2242 | } |
| 2243 | } |
| 2244 | } |
| 2245 | |
| 2246 | /* Even when lazy binding is disabled by "-z now", the PLT0 entry may |
| 2247 | still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for |
| 2248 | canonical function address. */ |
| 2249 | htab->plt.has_plt0 = 1; |
| 2250 | normal_target = plt_layout->normal_target; |
| 2251 | |
| 2252 | if (normal_target) |
| 2253 | { |
| 2254 | if (use_ibt_plt) |
| 2255 | { |
| 2256 | htab->lazy_plt = plt_layout->lazy_ibt_plt; |
| 2257 | htab->non_lazy_plt = plt_layout->non_lazy_ibt_plt; |
| 2258 | } |
| 2259 | else |
| 2260 | { |
| 2261 | htab->lazy_plt = plt_layout->lazy_plt; |
| 2262 | htab->non_lazy_plt = plt_layout->non_lazy_plt; |
| 2263 | } |
| 2264 | } |
| 2265 | else |
| 2266 | { |
| 2267 | htab->lazy_plt = plt_layout->lazy_plt; |
| 2268 | htab->non_lazy_plt = NULL; |
| 2269 | } |
| 2270 | |
| 2271 | pltsec = htab->elf.splt; |
| 2272 | |
| 2273 | /* If the non-lazy PLT is available, use it for all PLT entries if |
| 2274 | there are no PLT0 or no .plt section. */ |
| 2275 | if (htab->non_lazy_plt != NULL |
| 2276 | && (!htab->plt.has_plt0 || pltsec == NULL)) |
| 2277 | { |
| 2278 | lazy_plt = FALSE; |
| 2279 | if (bfd_link_pic (info)) |
| 2280 | htab->plt.plt_entry = htab->non_lazy_plt->pic_plt_entry; |
| 2281 | else |
| 2282 | htab->plt.plt_entry = htab->non_lazy_plt->plt_entry; |
| 2283 | htab->plt.plt_entry_size = htab->non_lazy_plt->plt_entry_size; |
| 2284 | htab->plt.plt_got_offset = htab->non_lazy_plt->plt_got_offset; |
| 2285 | htab->plt.plt_got_insn_size |
| 2286 | = htab->non_lazy_plt->plt_got_insn_size; |
| 2287 | htab->plt.eh_frame_plt_size |
| 2288 | = htab->non_lazy_plt->eh_frame_plt_size; |
| 2289 | htab->plt.eh_frame_plt = htab->non_lazy_plt->eh_frame_plt; |
| 2290 | } |
| 2291 | else |
| 2292 | { |
| 2293 | lazy_plt = TRUE; |
| 2294 | if (bfd_link_pic (info)) |
| 2295 | { |
| 2296 | htab->plt.plt0_entry = htab->lazy_plt->pic_plt0_entry; |
| 2297 | htab->plt.plt_entry = htab->lazy_plt->pic_plt_entry; |
| 2298 | } |
| 2299 | else |
| 2300 | { |
| 2301 | htab->plt.plt0_entry = htab->lazy_plt->plt0_entry; |
| 2302 | htab->plt.plt_entry = htab->lazy_plt->plt_entry; |
| 2303 | } |
| 2304 | htab->plt.plt_entry_size = htab->lazy_plt->plt_entry_size; |
| 2305 | htab->plt.plt_got_offset = htab->lazy_plt->plt_got_offset; |
| 2306 | htab->plt.plt_got_insn_size |
| 2307 | = htab->lazy_plt->plt_got_insn_size; |
| 2308 | htab->plt.eh_frame_plt_size |
| 2309 | = htab->lazy_plt->eh_frame_plt_size; |
| 2310 | htab->plt.eh_frame_plt = htab->lazy_plt->eh_frame_plt; |
| 2311 | } |
| 2312 | |
| 2313 | /* Return if there are no normal input files. */ |
| 2314 | if (dynobj == NULL) |
| 2315 | return pbfd; |
| 2316 | |
| 2317 | if (htab->is_vxworks |
| 2318 | && !elf_vxworks_create_dynamic_sections (dynobj, info, |
| 2319 | &htab->srelplt2)) |
| 2320 | { |
| 2321 | info->callbacks->einfo (_("%F: failed to create VxWorks dynamic sections\n")); |
| 2322 | return pbfd; |
| 2323 | } |
| 2324 | |
| 2325 | /* Since create_dynamic_sections isn't always called, but GOT |
| 2326 | relocations need GOT relocations, create them here so that we |
| 2327 | don't need to do it in check_relocs. */ |
| 2328 | if (htab->elf.sgot == NULL |
| 2329 | && !_bfd_elf_create_got_section (dynobj, info)) |
| 2330 | info->callbacks->einfo (_("%F: failed to create GOT sections\n")); |
| 2331 | |
| 2332 | got_align = (bed->target_id == X86_64_ELF_DATA) ? 3 : 2; |
| 2333 | |
| 2334 | /* Align .got and .got.plt sections to their entry size. Do it here |
| 2335 | instead of in create_dynamic_sections so that they are always |
| 2336 | properly aligned even if create_dynamic_sections isn't called. */ |
| 2337 | sec = htab->elf.sgot; |
| 2338 | if (!bfd_set_section_alignment (dynobj, sec, got_align)) |
| 2339 | goto error_alignment; |
| 2340 | |
| 2341 | sec = htab->elf.sgotplt; |
| 2342 | if (!bfd_set_section_alignment (dynobj, sec, got_align)) |
| 2343 | goto error_alignment; |
| 2344 | |
| 2345 | /* Create the ifunc sections here so that check_relocs can be |
| 2346 | simplified. */ |
| 2347 | if (!_bfd_elf_create_ifunc_sections (dynobj, info)) |
| 2348 | info->callbacks->einfo (_("%F: failed to create ifunc sections\n")); |
| 2349 | |
| 2350 | plt_alignment = bfd_log2 (htab->plt.plt_entry_size); |
| 2351 | |
| 2352 | if (pltsec != NULL) |
| 2353 | { |
| 2354 | /* Whe creating executable, set the contents of the .interp |
| 2355 | section to the interpreter. */ |
| 2356 | if (bfd_link_executable (info) && !info->nointerp) |
| 2357 | { |
| 2358 | asection *s = bfd_get_linker_section (dynobj, ".interp"); |
| 2359 | if (s == NULL) |
| 2360 | abort (); |
| 2361 | s->size = htab->dynamic_interpreter_size; |
| 2362 | s->contents = (unsigned char *) htab->dynamic_interpreter; |
| 2363 | htab->interp = s; |
| 2364 | } |
| 2365 | |
| 2366 | /* Don't change PLT section alignment for NaCl since it uses |
| 2367 | 64-byte PLT entry and sets PLT section alignment to 32 |
| 2368 | bytes. Don't create additional PLT sections for NaCl. */ |
| 2369 | if (normal_target) |
| 2370 | { |
| 2371 | flagword pltflags = (bed->dynamic_sec_flags |
| 2372 | | SEC_ALLOC |
| 2373 | | SEC_CODE |
| 2374 | | SEC_LOAD |
| 2375 | | SEC_READONLY); |
| 2376 | unsigned int non_lazy_plt_alignment |
| 2377 | = bfd_log2 (htab->non_lazy_plt->plt_entry_size); |
| 2378 | |
| 2379 | sec = pltsec; |
| 2380 | if (!bfd_set_section_alignment (sec->owner, sec, |
| 2381 | plt_alignment)) |
| 2382 | goto error_alignment; |
| 2383 | |
| 2384 | /* Create the GOT procedure linkage table. */ |
| 2385 | sec = bfd_make_section_anyway_with_flags (dynobj, |
| 2386 | ".plt.got", |
| 2387 | pltflags); |
| 2388 | if (sec == NULL) |
| 2389 | info->callbacks->einfo (_("%F: failed to create GOT PLT section\n")); |
| 2390 | |
| 2391 | if (!bfd_set_section_alignment (dynobj, sec, |
| 2392 | non_lazy_plt_alignment)) |
| 2393 | goto error_alignment; |
| 2394 | |
| 2395 | htab->plt_got = sec; |
| 2396 | |
| 2397 | if (lazy_plt) |
| 2398 | { |
| 2399 | sec = NULL; |
| 2400 | |
| 2401 | if (use_ibt_plt) |
| 2402 | { |
| 2403 | /* Create the second PLT for Intel IBT support. IBT |
| 2404 | PLT is supported only for non-NaCl target and is |
| 2405 | is needed only for lazy binding. */ |
| 2406 | sec = bfd_make_section_anyway_with_flags (dynobj, |
| 2407 | ".plt.sec", |
| 2408 | pltflags); |
| 2409 | if (sec == NULL) |
| 2410 | info->callbacks->einfo (_("%F: failed to create IBT-enabled PLT section\n")); |
| 2411 | |
| 2412 | if (!bfd_set_section_alignment (dynobj, sec, |
| 2413 | plt_alignment)) |
| 2414 | goto error_alignment; |
| 2415 | } |
| 2416 | else if (info->bndplt && ABI_64_P (dynobj)) |
| 2417 | { |
| 2418 | /* Create the second PLT for Intel MPX support. MPX |
| 2419 | PLT is supported only for non-NaCl target in 64-bit |
| 2420 | mode and is needed only for lazy binding. */ |
| 2421 | sec = bfd_make_section_anyway_with_flags (dynobj, |
| 2422 | ".plt.sec", |
| 2423 | pltflags); |
| 2424 | if (sec == NULL) |
| 2425 | info->callbacks->einfo (_("%F: failed to create BND PLT section\n")); |
| 2426 | |
| 2427 | if (!bfd_set_section_alignment (dynobj, sec, |
| 2428 | non_lazy_plt_alignment)) |
| 2429 | goto error_alignment; |
| 2430 | } |
| 2431 | |
| 2432 | htab->plt_second = sec; |
| 2433 | } |
| 2434 | } |
| 2435 | |
| 2436 | if (!info->no_ld_generated_unwind_info) |
| 2437 | { |
| 2438 | flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY |
| 2439 | | SEC_HAS_CONTENTS | SEC_IN_MEMORY |
| 2440 | | SEC_LINKER_CREATED); |
| 2441 | |
| 2442 | sec = bfd_make_section_anyway_with_flags (dynobj, |
| 2443 | ".eh_frame", |
| 2444 | flags); |
| 2445 | if (sec == NULL) |
| 2446 | info->callbacks->einfo (_("%F: failed to create PLT .eh_frame section\n")); |
| 2447 | |
| 2448 | if (!bfd_set_section_alignment (dynobj, sec, class_align)) |
| 2449 | goto error_alignment; |
| 2450 | |
| 2451 | htab->plt_eh_frame = sec; |
| 2452 | |
| 2453 | if (htab->plt_got != NULL) |
| 2454 | { |
| 2455 | sec = bfd_make_section_anyway_with_flags (dynobj, |
| 2456 | ".eh_frame", |
| 2457 | flags); |
| 2458 | if (sec == NULL) |
| 2459 | info->callbacks->einfo (_("%F: failed to create GOT PLT .eh_frame section\n")); |
| 2460 | |
| 2461 | if (!bfd_set_section_alignment (dynobj, sec, class_align)) |
| 2462 | goto error_alignment; |
| 2463 | |
| 2464 | htab->plt_got_eh_frame = sec; |
| 2465 | } |
| 2466 | |
| 2467 | if (htab->plt_second != NULL) |
| 2468 | { |
| 2469 | sec = bfd_make_section_anyway_with_flags (dynobj, |
| 2470 | ".eh_frame", |
| 2471 | flags); |
| 2472 | if (sec == NULL) |
| 2473 | info->callbacks->einfo (_("%F: failed to create the second PLT .eh_frame section\n")); |
| 2474 | |
| 2475 | if (!bfd_set_section_alignment (dynobj, sec, class_align)) |
| 2476 | goto error_alignment; |
| 2477 | |
| 2478 | htab->plt_second_eh_frame = sec; |
| 2479 | } |
| 2480 | } |
| 2481 | } |
| 2482 | |
| 2483 | if (normal_target) |
| 2484 | { |
| 2485 | /* The .iplt section is used for IFUNC symbols in static |
| 2486 | executables. */ |
| 2487 | sec = htab->elf.iplt; |
| 2488 | if (sec != NULL |
| 2489 | && !bfd_set_section_alignment (sec->owner, sec, |
| 2490 | plt_alignment)) |
| 2491 | goto error_alignment; |
| 2492 | } |
| 2493 | |
| 2494 | return pbfd; |
| 2495 | } |