| 1 | /* .eh_frame section optimization. |
| 2 | Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007 |
| 3 | Free Software Foundation, Inc. |
| 4 | Written by Jakub Jelinek <jakub@redhat.com>. |
| 5 | |
| 6 | This file is part of BFD, the Binary File Descriptor library. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 3 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software |
| 20 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| 21 | MA 02110-1301, USA. */ |
| 22 | |
| 23 | #include "sysdep.h" |
| 24 | #include "bfd.h" |
| 25 | #include "libbfd.h" |
| 26 | #include "elf-bfd.h" |
| 27 | #include "elf/dwarf2.h" |
| 28 | |
| 29 | #define EH_FRAME_HDR_SIZE 8 |
| 30 | |
| 31 | struct cie |
| 32 | { |
| 33 | unsigned int length; |
| 34 | unsigned int hash; |
| 35 | unsigned char version; |
| 36 | unsigned char local_personality; |
| 37 | char augmentation[20]; |
| 38 | bfd_vma code_align; |
| 39 | bfd_signed_vma data_align; |
| 40 | bfd_vma ra_column; |
| 41 | bfd_vma augmentation_size; |
| 42 | union { |
| 43 | struct elf_link_hash_entry *h; |
| 44 | bfd_vma val; |
| 45 | } personality; |
| 46 | asection *output_sec; |
| 47 | struct eh_cie_fde *cie_inf; |
| 48 | unsigned char per_encoding; |
| 49 | unsigned char lsda_encoding; |
| 50 | unsigned char fde_encoding; |
| 51 | unsigned char initial_insn_length; |
| 52 | unsigned char make_relative; |
| 53 | unsigned char make_lsda_relative; |
| 54 | unsigned char initial_instructions[50]; |
| 55 | }; |
| 56 | |
| 57 | |
| 58 | |
| 59 | /* If *ITER hasn't reached END yet, read the next byte into *RESULT and |
| 60 | move onto the next byte. Return true on success. */ |
| 61 | |
| 62 | static inline bfd_boolean |
| 63 | read_byte (bfd_byte **iter, bfd_byte *end, unsigned char *result) |
| 64 | { |
| 65 | if (*iter >= end) |
| 66 | return FALSE; |
| 67 | *result = *((*iter)++); |
| 68 | return TRUE; |
| 69 | } |
| 70 | |
| 71 | /* Move *ITER over LENGTH bytes, or up to END, whichever is closer. |
| 72 | Return true it was possible to move LENGTH bytes. */ |
| 73 | |
| 74 | static inline bfd_boolean |
| 75 | skip_bytes (bfd_byte **iter, bfd_byte *end, bfd_size_type length) |
| 76 | { |
| 77 | if ((bfd_size_type) (end - *iter) < length) |
| 78 | { |
| 79 | *iter = end; |
| 80 | return FALSE; |
| 81 | } |
| 82 | *iter += length; |
| 83 | return TRUE; |
| 84 | } |
| 85 | |
| 86 | /* Move *ITER over an leb128, stopping at END. Return true if the end |
| 87 | of the leb128 was found. */ |
| 88 | |
| 89 | static bfd_boolean |
| 90 | skip_leb128 (bfd_byte **iter, bfd_byte *end) |
| 91 | { |
| 92 | unsigned char byte; |
| 93 | do |
| 94 | if (!read_byte (iter, end, &byte)) |
| 95 | return FALSE; |
| 96 | while (byte & 0x80); |
| 97 | return TRUE; |
| 98 | } |
| 99 | |
| 100 | /* Like skip_leb128, but treat the leb128 as an unsigned value and |
| 101 | store it in *VALUE. */ |
| 102 | |
| 103 | static bfd_boolean |
| 104 | read_uleb128 (bfd_byte **iter, bfd_byte *end, bfd_vma *value) |
| 105 | { |
| 106 | bfd_byte *start, *p; |
| 107 | |
| 108 | start = *iter; |
| 109 | if (!skip_leb128 (iter, end)) |
| 110 | return FALSE; |
| 111 | |
| 112 | p = *iter; |
| 113 | *value = *--p; |
| 114 | while (p > start) |
| 115 | *value = (*value << 7) | (*--p & 0x7f); |
| 116 | |
| 117 | return TRUE; |
| 118 | } |
| 119 | |
| 120 | /* Like read_uleb128, but for signed values. */ |
| 121 | |
| 122 | static bfd_boolean |
| 123 | read_sleb128 (bfd_byte **iter, bfd_byte *end, bfd_signed_vma *value) |
| 124 | { |
| 125 | bfd_byte *start, *p; |
| 126 | |
| 127 | start = *iter; |
| 128 | if (!skip_leb128 (iter, end)) |
| 129 | return FALSE; |
| 130 | |
| 131 | p = *iter; |
| 132 | *value = ((*--p & 0x7f) ^ 0x40) - 0x40; |
| 133 | while (p > start) |
| 134 | *value = (*value << 7) | (*--p & 0x7f); |
| 135 | |
| 136 | return TRUE; |
| 137 | } |
| 138 | |
| 139 | /* Return 0 if either encoding is variable width, or not yet known to bfd. */ |
| 140 | |
| 141 | static |
| 142 | int get_DW_EH_PE_width (int encoding, int ptr_size) |
| 143 | { |
| 144 | /* DW_EH_PE_ values of 0x60 and 0x70 weren't defined at the time .eh_frame |
| 145 | was added to bfd. */ |
| 146 | if ((encoding & 0x60) == 0x60) |
| 147 | return 0; |
| 148 | |
| 149 | switch (encoding & 7) |
| 150 | { |
| 151 | case DW_EH_PE_udata2: return 2; |
| 152 | case DW_EH_PE_udata4: return 4; |
| 153 | case DW_EH_PE_udata8: return 8; |
| 154 | case DW_EH_PE_absptr: return ptr_size; |
| 155 | default: |
| 156 | break; |
| 157 | } |
| 158 | |
| 159 | return 0; |
| 160 | } |
| 161 | |
| 162 | #define get_DW_EH_PE_signed(encoding) (((encoding) & DW_EH_PE_signed) != 0) |
| 163 | |
| 164 | /* Read a width sized value from memory. */ |
| 165 | |
| 166 | static bfd_vma |
| 167 | read_value (bfd *abfd, bfd_byte *buf, int width, int is_signed) |
| 168 | { |
| 169 | bfd_vma value; |
| 170 | |
| 171 | switch (width) |
| 172 | { |
| 173 | case 2: |
| 174 | if (is_signed) |
| 175 | value = bfd_get_signed_16 (abfd, buf); |
| 176 | else |
| 177 | value = bfd_get_16 (abfd, buf); |
| 178 | break; |
| 179 | case 4: |
| 180 | if (is_signed) |
| 181 | value = bfd_get_signed_32 (abfd, buf); |
| 182 | else |
| 183 | value = bfd_get_32 (abfd, buf); |
| 184 | break; |
| 185 | case 8: |
| 186 | if (is_signed) |
| 187 | value = bfd_get_signed_64 (abfd, buf); |
| 188 | else |
| 189 | value = bfd_get_64 (abfd, buf); |
| 190 | break; |
| 191 | default: |
| 192 | BFD_FAIL (); |
| 193 | return 0; |
| 194 | } |
| 195 | |
| 196 | return value; |
| 197 | } |
| 198 | |
| 199 | /* Store a width sized value to memory. */ |
| 200 | |
| 201 | static void |
| 202 | write_value (bfd *abfd, bfd_byte *buf, bfd_vma value, int width) |
| 203 | { |
| 204 | switch (width) |
| 205 | { |
| 206 | case 2: bfd_put_16 (abfd, value, buf); break; |
| 207 | case 4: bfd_put_32 (abfd, value, buf); break; |
| 208 | case 8: bfd_put_64 (abfd, value, buf); break; |
| 209 | default: BFD_FAIL (); |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | /* Return one if C1 and C2 CIEs can be merged. */ |
| 214 | |
| 215 | static int |
| 216 | cie_eq (const void *e1, const void *e2) |
| 217 | { |
| 218 | const struct cie *c1 = e1; |
| 219 | const struct cie *c2 = e2; |
| 220 | |
| 221 | if (c1->hash == c2->hash |
| 222 | && c1->length == c2->length |
| 223 | && c1->version == c2->version |
| 224 | && c1->local_personality == c2->local_personality |
| 225 | && strcmp (c1->augmentation, c2->augmentation) == 0 |
| 226 | && strcmp (c1->augmentation, "eh") != 0 |
| 227 | && c1->code_align == c2->code_align |
| 228 | && c1->data_align == c2->data_align |
| 229 | && c1->ra_column == c2->ra_column |
| 230 | && c1->augmentation_size == c2->augmentation_size |
| 231 | && memcmp (&c1->personality, &c2->personality, |
| 232 | sizeof (c1->personality)) == 0 |
| 233 | && c1->output_sec == c2->output_sec |
| 234 | && c1->per_encoding == c2->per_encoding |
| 235 | && c1->lsda_encoding == c2->lsda_encoding |
| 236 | && c1->fde_encoding == c2->fde_encoding |
| 237 | && c1->initial_insn_length == c2->initial_insn_length |
| 238 | && memcmp (c1->initial_instructions, |
| 239 | c2->initial_instructions, |
| 240 | c1->initial_insn_length) == 0) |
| 241 | return 1; |
| 242 | |
| 243 | return 0; |
| 244 | } |
| 245 | |
| 246 | static hashval_t |
| 247 | cie_hash (const void *e) |
| 248 | { |
| 249 | const struct cie *c = e; |
| 250 | return c->hash; |
| 251 | } |
| 252 | |
| 253 | static hashval_t |
| 254 | cie_compute_hash (struct cie *c) |
| 255 | { |
| 256 | hashval_t h = 0; |
| 257 | h = iterative_hash_object (c->length, h); |
| 258 | h = iterative_hash_object (c->version, h); |
| 259 | h = iterative_hash (c->augmentation, strlen (c->augmentation) + 1, h); |
| 260 | h = iterative_hash_object (c->code_align, h); |
| 261 | h = iterative_hash_object (c->data_align, h); |
| 262 | h = iterative_hash_object (c->ra_column, h); |
| 263 | h = iterative_hash_object (c->augmentation_size, h); |
| 264 | h = iterative_hash_object (c->personality, h); |
| 265 | h = iterative_hash_object (c->output_sec, h); |
| 266 | h = iterative_hash_object (c->per_encoding, h); |
| 267 | h = iterative_hash_object (c->lsda_encoding, h); |
| 268 | h = iterative_hash_object (c->fde_encoding, h); |
| 269 | h = iterative_hash_object (c->initial_insn_length, h); |
| 270 | h = iterative_hash (c->initial_instructions, c->initial_insn_length, h); |
| 271 | c->hash = h; |
| 272 | return h; |
| 273 | } |
| 274 | |
| 275 | /* Return the number of extra bytes that we'll be inserting into |
| 276 | ENTRY's augmentation string. */ |
| 277 | |
| 278 | static INLINE unsigned int |
| 279 | extra_augmentation_string_bytes (struct eh_cie_fde *entry) |
| 280 | { |
| 281 | unsigned int size = 0; |
| 282 | if (entry->cie) |
| 283 | { |
| 284 | if (entry->add_augmentation_size) |
| 285 | size++; |
| 286 | if (entry->add_fde_encoding) |
| 287 | size++; |
| 288 | } |
| 289 | return size; |
| 290 | } |
| 291 | |
| 292 | /* Likewise ENTRY's augmentation data. */ |
| 293 | |
| 294 | static INLINE unsigned int |
| 295 | extra_augmentation_data_bytes (struct eh_cie_fde *entry) |
| 296 | { |
| 297 | unsigned int size = 0; |
| 298 | if (entry->cie) |
| 299 | { |
| 300 | if (entry->add_augmentation_size) |
| 301 | size++; |
| 302 | if (entry->add_fde_encoding) |
| 303 | size++; |
| 304 | } |
| 305 | else |
| 306 | { |
| 307 | if (entry->cie_inf->add_augmentation_size) |
| 308 | size++; |
| 309 | } |
| 310 | return size; |
| 311 | } |
| 312 | |
| 313 | /* Return the size that ENTRY will have in the output. ALIGNMENT is the |
| 314 | required alignment of ENTRY in bytes. */ |
| 315 | |
| 316 | static unsigned int |
| 317 | size_of_output_cie_fde (struct eh_cie_fde *entry, unsigned int alignment) |
| 318 | { |
| 319 | if (entry->removed) |
| 320 | return 0; |
| 321 | if (entry->size == 4) |
| 322 | return 4; |
| 323 | return (entry->size |
| 324 | + extra_augmentation_string_bytes (entry) |
| 325 | + extra_augmentation_data_bytes (entry) |
| 326 | + alignment - 1) & -alignment; |
| 327 | } |
| 328 | |
| 329 | /* Assume that the bytes between *ITER and END are CFA instructions. |
| 330 | Try to move *ITER past the first instruction and return true on |
| 331 | success. ENCODED_PTR_WIDTH gives the width of pointer entries. */ |
| 332 | |
| 333 | static bfd_boolean |
| 334 | skip_cfa_op (bfd_byte **iter, bfd_byte *end, unsigned int encoded_ptr_width) |
| 335 | { |
| 336 | bfd_byte op; |
| 337 | bfd_vma length; |
| 338 | |
| 339 | if (!read_byte (iter, end, &op)) |
| 340 | return FALSE; |
| 341 | |
| 342 | switch (op & 0xc0 ? op & 0xc0 : op) |
| 343 | { |
| 344 | case DW_CFA_nop: |
| 345 | case DW_CFA_advance_loc: |
| 346 | case DW_CFA_restore: |
| 347 | case DW_CFA_remember_state: |
| 348 | case DW_CFA_restore_state: |
| 349 | case DW_CFA_GNU_window_save: |
| 350 | /* No arguments. */ |
| 351 | return TRUE; |
| 352 | |
| 353 | case DW_CFA_offset: |
| 354 | case DW_CFA_restore_extended: |
| 355 | case DW_CFA_undefined: |
| 356 | case DW_CFA_same_value: |
| 357 | case DW_CFA_def_cfa_register: |
| 358 | case DW_CFA_def_cfa_offset: |
| 359 | case DW_CFA_def_cfa_offset_sf: |
| 360 | case DW_CFA_GNU_args_size: |
| 361 | /* One leb128 argument. */ |
| 362 | return skip_leb128 (iter, end); |
| 363 | |
| 364 | case DW_CFA_val_offset: |
| 365 | case DW_CFA_val_offset_sf: |
| 366 | case DW_CFA_offset_extended: |
| 367 | case DW_CFA_register: |
| 368 | case DW_CFA_def_cfa: |
| 369 | case DW_CFA_offset_extended_sf: |
| 370 | case DW_CFA_GNU_negative_offset_extended: |
| 371 | case DW_CFA_def_cfa_sf: |
| 372 | /* Two leb128 arguments. */ |
| 373 | return (skip_leb128 (iter, end) |
| 374 | && skip_leb128 (iter, end)); |
| 375 | |
| 376 | case DW_CFA_def_cfa_expression: |
| 377 | /* A variable-length argument. */ |
| 378 | return (read_uleb128 (iter, end, &length) |
| 379 | && skip_bytes (iter, end, length)); |
| 380 | |
| 381 | case DW_CFA_expression: |
| 382 | case DW_CFA_val_expression: |
| 383 | /* A leb128 followed by a variable-length argument. */ |
| 384 | return (skip_leb128 (iter, end) |
| 385 | && read_uleb128 (iter, end, &length) |
| 386 | && skip_bytes (iter, end, length)); |
| 387 | |
| 388 | case DW_CFA_set_loc: |
| 389 | return skip_bytes (iter, end, encoded_ptr_width); |
| 390 | |
| 391 | case DW_CFA_advance_loc1: |
| 392 | return skip_bytes (iter, end, 1); |
| 393 | |
| 394 | case DW_CFA_advance_loc2: |
| 395 | return skip_bytes (iter, end, 2); |
| 396 | |
| 397 | case DW_CFA_advance_loc4: |
| 398 | return skip_bytes (iter, end, 4); |
| 399 | |
| 400 | case DW_CFA_MIPS_advance_loc8: |
| 401 | return skip_bytes (iter, end, 8); |
| 402 | |
| 403 | default: |
| 404 | return FALSE; |
| 405 | } |
| 406 | } |
| 407 | |
| 408 | /* Try to interpret the bytes between BUF and END as CFA instructions. |
| 409 | If every byte makes sense, return a pointer to the first DW_CFA_nop |
| 410 | padding byte, or END if there is no padding. Return null otherwise. |
| 411 | ENCODED_PTR_WIDTH is as for skip_cfa_op. */ |
| 412 | |
| 413 | static bfd_byte * |
| 414 | skip_non_nops (bfd_byte *buf, bfd_byte *end, unsigned int encoded_ptr_width, |
| 415 | unsigned int *set_loc_count) |
| 416 | { |
| 417 | bfd_byte *last; |
| 418 | |
| 419 | last = buf; |
| 420 | while (buf < end) |
| 421 | if (*buf == DW_CFA_nop) |
| 422 | buf++; |
| 423 | else |
| 424 | { |
| 425 | if (*buf == DW_CFA_set_loc) |
| 426 | ++*set_loc_count; |
| 427 | if (!skip_cfa_op (&buf, end, encoded_ptr_width)) |
| 428 | return 0; |
| 429 | last = buf; |
| 430 | } |
| 431 | return last; |
| 432 | } |
| 433 | |
| 434 | /* This function is called for each input file before the .eh_frame |
| 435 | section is relocated. It discards duplicate CIEs and FDEs for discarded |
| 436 | functions. The function returns TRUE iff any entries have been |
| 437 | deleted. */ |
| 438 | |
| 439 | bfd_boolean |
| 440 | _bfd_elf_discard_section_eh_frame |
| 441 | (bfd *abfd, struct bfd_link_info *info, asection *sec, |
| 442 | bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *), |
| 443 | struct elf_reloc_cookie *cookie) |
| 444 | { |
| 445 | #define REQUIRE(COND) \ |
| 446 | do \ |
| 447 | if (!(COND)) \ |
| 448 | goto free_no_table; \ |
| 449 | while (0) |
| 450 | |
| 451 | bfd_byte *ehbuf = NULL, *buf; |
| 452 | bfd_byte *last_fde; |
| 453 | struct eh_cie_fde *ent, *this_inf; |
| 454 | unsigned int hdr_length, hdr_id; |
| 455 | struct extended_cie |
| 456 | { |
| 457 | struct cie cie; |
| 458 | unsigned int offset; |
| 459 | unsigned int usage_count; |
| 460 | unsigned int entry; |
| 461 | } *ecies = NULL, *ecie; |
| 462 | unsigned int ecie_count = 0, ecie_alloced = 0; |
| 463 | struct cie *cie; |
| 464 | struct elf_link_hash_table *htab; |
| 465 | struct eh_frame_hdr_info *hdr_info; |
| 466 | struct eh_frame_sec_info *sec_info = NULL; |
| 467 | unsigned int offset; |
| 468 | unsigned int ptr_size; |
| 469 | unsigned int entry_alloced; |
| 470 | |
| 471 | if (sec->size == 0) |
| 472 | { |
| 473 | /* This file does not contain .eh_frame information. */ |
| 474 | return FALSE; |
| 475 | } |
| 476 | |
| 477 | if (bfd_is_abs_section (sec->output_section)) |
| 478 | { |
| 479 | /* At least one of the sections is being discarded from the |
| 480 | link, so we should just ignore them. */ |
| 481 | return FALSE; |
| 482 | } |
| 483 | |
| 484 | htab = elf_hash_table (info); |
| 485 | hdr_info = &htab->eh_info; |
| 486 | |
| 487 | if (hdr_info->cies == NULL && !info->relocatable) |
| 488 | hdr_info->cies = htab_try_create (1, cie_hash, cie_eq, free); |
| 489 | |
| 490 | /* Read the frame unwind information from abfd. */ |
| 491 | |
| 492 | REQUIRE (bfd_malloc_and_get_section (abfd, sec, &ehbuf)); |
| 493 | |
| 494 | if (sec->size >= 4 |
| 495 | && bfd_get_32 (abfd, ehbuf) == 0 |
| 496 | && cookie->rel == cookie->relend) |
| 497 | { |
| 498 | /* Empty .eh_frame section. */ |
| 499 | free (ehbuf); |
| 500 | return FALSE; |
| 501 | } |
| 502 | |
| 503 | /* If .eh_frame section size doesn't fit into int, we cannot handle |
| 504 | it (it would need to use 64-bit .eh_frame format anyway). */ |
| 505 | REQUIRE (sec->size == (unsigned int) sec->size); |
| 506 | |
| 507 | ptr_size = (get_elf_backend_data (abfd) |
| 508 | ->elf_backend_eh_frame_address_size (abfd, sec)); |
| 509 | REQUIRE (ptr_size != 0); |
| 510 | |
| 511 | buf = ehbuf; |
| 512 | sec_info = bfd_zmalloc (sizeof (struct eh_frame_sec_info) |
| 513 | + 99 * sizeof (struct eh_cie_fde)); |
| 514 | REQUIRE (sec_info); |
| 515 | |
| 516 | entry_alloced = 100; |
| 517 | |
| 518 | #define ENSURE_NO_RELOCS(buf) \ |
| 519 | REQUIRE (!(cookie->rel < cookie->relend \ |
| 520 | && (cookie->rel->r_offset \ |
| 521 | < (bfd_size_type) ((buf) - ehbuf)) \ |
| 522 | && cookie->rel->r_info != 0)) |
| 523 | |
| 524 | #define SKIP_RELOCS(buf) \ |
| 525 | while (cookie->rel < cookie->relend \ |
| 526 | && (cookie->rel->r_offset \ |
| 527 | < (bfd_size_type) ((buf) - ehbuf))) \ |
| 528 | cookie->rel++ |
| 529 | |
| 530 | #define GET_RELOC(buf) \ |
| 531 | ((cookie->rel < cookie->relend \ |
| 532 | && (cookie->rel->r_offset \ |
| 533 | == (bfd_size_type) ((buf) - ehbuf))) \ |
| 534 | ? cookie->rel : NULL) |
| 535 | |
| 536 | for (;;) |
| 537 | { |
| 538 | char *aug; |
| 539 | bfd_byte *start, *end, *insns, *insns_end; |
| 540 | bfd_size_type length; |
| 541 | unsigned int set_loc_count; |
| 542 | |
| 543 | if (sec_info->count == entry_alloced) |
| 544 | { |
| 545 | sec_info = bfd_realloc (sec_info, |
| 546 | sizeof (struct eh_frame_sec_info) |
| 547 | + ((entry_alloced + 99) |
| 548 | * sizeof (struct eh_cie_fde))); |
| 549 | REQUIRE (sec_info); |
| 550 | |
| 551 | memset (&sec_info->entry[entry_alloced], 0, |
| 552 | 100 * sizeof (struct eh_cie_fde)); |
| 553 | entry_alloced += 100; |
| 554 | } |
| 555 | |
| 556 | this_inf = sec_info->entry + sec_info->count; |
| 557 | last_fde = buf; |
| 558 | |
| 559 | if ((bfd_size_type) (buf - ehbuf) == sec->size) |
| 560 | break; |
| 561 | |
| 562 | /* Read the length of the entry. */ |
| 563 | REQUIRE (skip_bytes (&buf, ehbuf + sec->size, 4)); |
| 564 | hdr_length = bfd_get_32 (abfd, buf - 4); |
| 565 | |
| 566 | /* 64-bit .eh_frame is not supported. */ |
| 567 | REQUIRE (hdr_length != 0xffffffff); |
| 568 | |
| 569 | /* The CIE/FDE must be fully contained in this input section. */ |
| 570 | REQUIRE ((bfd_size_type) (buf - ehbuf) + hdr_length <= sec->size); |
| 571 | end = buf + hdr_length; |
| 572 | |
| 573 | this_inf->offset = last_fde - ehbuf; |
| 574 | this_inf->size = 4 + hdr_length; |
| 575 | |
| 576 | if (hdr_length == 0) |
| 577 | { |
| 578 | /* A zero-length CIE should only be found at the end of |
| 579 | the section. */ |
| 580 | REQUIRE ((bfd_size_type) (buf - ehbuf) == sec->size); |
| 581 | ENSURE_NO_RELOCS (buf); |
| 582 | sec_info->count++; |
| 583 | break; |
| 584 | } |
| 585 | |
| 586 | REQUIRE (skip_bytes (&buf, end, 4)); |
| 587 | hdr_id = bfd_get_32 (abfd, buf - 4); |
| 588 | |
| 589 | if (hdr_id == 0) |
| 590 | { |
| 591 | unsigned int initial_insn_length; |
| 592 | |
| 593 | /* CIE */ |
| 594 | this_inf->cie = 1; |
| 595 | |
| 596 | if (ecie_count == ecie_alloced) |
| 597 | { |
| 598 | ecies = bfd_realloc (ecies, |
| 599 | (ecie_alloced + 20) * sizeof (*ecies)); |
| 600 | REQUIRE (ecies); |
| 601 | memset (&ecies[ecie_alloced], 0, 20 * sizeof (*ecies)); |
| 602 | ecie_alloced += 20; |
| 603 | } |
| 604 | |
| 605 | cie = &ecies[ecie_count].cie; |
| 606 | ecies[ecie_count].offset = this_inf->offset; |
| 607 | ecies[ecie_count++].entry = sec_info->count; |
| 608 | cie->length = hdr_length; |
| 609 | start = buf; |
| 610 | REQUIRE (read_byte (&buf, end, &cie->version)); |
| 611 | |
| 612 | /* Cannot handle unknown versions. */ |
| 613 | REQUIRE (cie->version == 1 || cie->version == 3); |
| 614 | REQUIRE (strlen ((char *) buf) < sizeof (cie->augmentation)); |
| 615 | |
| 616 | strcpy (cie->augmentation, (char *) buf); |
| 617 | buf = (bfd_byte *) strchr ((char *) buf, '\0') + 1; |
| 618 | ENSURE_NO_RELOCS (buf); |
| 619 | if (buf[0] == 'e' && buf[1] == 'h') |
| 620 | { |
| 621 | /* GCC < 3.0 .eh_frame CIE */ |
| 622 | /* We cannot merge "eh" CIEs because __EXCEPTION_TABLE__ |
| 623 | is private to each CIE, so we don't need it for anything. |
| 624 | Just skip it. */ |
| 625 | REQUIRE (skip_bytes (&buf, end, ptr_size)); |
| 626 | SKIP_RELOCS (buf); |
| 627 | } |
| 628 | REQUIRE (read_uleb128 (&buf, end, &cie->code_align)); |
| 629 | REQUIRE (read_sleb128 (&buf, end, &cie->data_align)); |
| 630 | if (cie->version == 1) |
| 631 | { |
| 632 | REQUIRE (buf < end); |
| 633 | cie->ra_column = *buf++; |
| 634 | } |
| 635 | else |
| 636 | REQUIRE (read_uleb128 (&buf, end, &cie->ra_column)); |
| 637 | ENSURE_NO_RELOCS (buf); |
| 638 | cie->lsda_encoding = DW_EH_PE_omit; |
| 639 | cie->fde_encoding = DW_EH_PE_omit; |
| 640 | cie->per_encoding = DW_EH_PE_omit; |
| 641 | aug = cie->augmentation; |
| 642 | if (aug[0] != 'e' || aug[1] != 'h') |
| 643 | { |
| 644 | if (*aug == 'z') |
| 645 | { |
| 646 | aug++; |
| 647 | REQUIRE (read_uleb128 (&buf, end, &cie->augmentation_size)); |
| 648 | ENSURE_NO_RELOCS (buf); |
| 649 | } |
| 650 | |
| 651 | while (*aug != '\0') |
| 652 | switch (*aug++) |
| 653 | { |
| 654 | case 'L': |
| 655 | REQUIRE (read_byte (&buf, end, &cie->lsda_encoding)); |
| 656 | ENSURE_NO_RELOCS (buf); |
| 657 | REQUIRE (get_DW_EH_PE_width (cie->lsda_encoding, ptr_size)); |
| 658 | break; |
| 659 | case 'R': |
| 660 | REQUIRE (read_byte (&buf, end, &cie->fde_encoding)); |
| 661 | ENSURE_NO_RELOCS (buf); |
| 662 | REQUIRE (get_DW_EH_PE_width (cie->fde_encoding, ptr_size)); |
| 663 | break; |
| 664 | case 'S': |
| 665 | break; |
| 666 | case 'P': |
| 667 | { |
| 668 | int per_width; |
| 669 | |
| 670 | REQUIRE (read_byte (&buf, end, &cie->per_encoding)); |
| 671 | per_width = get_DW_EH_PE_width (cie->per_encoding, |
| 672 | ptr_size); |
| 673 | REQUIRE (per_width); |
| 674 | if ((cie->per_encoding & 0xf0) == DW_EH_PE_aligned) |
| 675 | { |
| 676 | length = -(buf - ehbuf) & (per_width - 1); |
| 677 | REQUIRE (skip_bytes (&buf, end, length)); |
| 678 | } |
| 679 | ENSURE_NO_RELOCS (buf); |
| 680 | /* Ensure we have a reloc here. */ |
| 681 | if (GET_RELOC (buf) != NULL) |
| 682 | { |
| 683 | unsigned long r_symndx; |
| 684 | |
| 685 | #ifdef BFD64 |
| 686 | if (ptr_size == 8) |
| 687 | r_symndx = ELF64_R_SYM (cookie->rel->r_info); |
| 688 | else |
| 689 | #endif |
| 690 | r_symndx = ELF32_R_SYM (cookie->rel->r_info); |
| 691 | if (r_symndx >= cookie->locsymcount |
| 692 | || ELF_ST_BIND (cookie->locsyms[r_symndx] |
| 693 | .st_info) != STB_LOCAL) |
| 694 | { |
| 695 | struct elf_link_hash_entry *h; |
| 696 | |
| 697 | r_symndx -= cookie->extsymoff; |
| 698 | h = cookie->sym_hashes[r_symndx]; |
| 699 | |
| 700 | while (h->root.type == bfd_link_hash_indirect |
| 701 | || h->root.type == bfd_link_hash_warning) |
| 702 | h = (struct elf_link_hash_entry *) |
| 703 | h->root.u.i.link; |
| 704 | |
| 705 | cie->personality.h = h; |
| 706 | } |
| 707 | else |
| 708 | { |
| 709 | Elf_Internal_Sym *sym; |
| 710 | asection *sym_sec; |
| 711 | bfd_vma val; |
| 712 | |
| 713 | sym = &cookie->locsyms[r_symndx]; |
| 714 | sym_sec = (bfd_section_from_elf_index |
| 715 | (abfd, sym->st_shndx)); |
| 716 | if (sym_sec != NULL) |
| 717 | { |
| 718 | if (sym_sec->kept_section != NULL) |
| 719 | sym_sec = sym_sec->kept_section; |
| 720 | if (sym_sec->output_section != NULL) |
| 721 | { |
| 722 | val = (sym->st_value |
| 723 | + sym_sec->output_offset |
| 724 | + sym_sec->output_section->vma); |
| 725 | cie->personality.val = val; |
| 726 | cie->local_personality = 1; |
| 727 | } |
| 728 | } |
| 729 | } |
| 730 | |
| 731 | /* Cope with MIPS-style composite relocations. */ |
| 732 | do |
| 733 | cookie->rel++; |
| 734 | while (GET_RELOC (buf) != NULL); |
| 735 | } |
| 736 | REQUIRE (skip_bytes (&buf, end, per_width)); |
| 737 | REQUIRE (cie->local_personality || cie->personality.h); |
| 738 | } |
| 739 | break; |
| 740 | default: |
| 741 | /* Unrecognized augmentation. Better bail out. */ |
| 742 | goto free_no_table; |
| 743 | } |
| 744 | } |
| 745 | |
| 746 | /* For shared libraries, try to get rid of as many RELATIVE relocs |
| 747 | as possible. */ |
| 748 | if (info->shared |
| 749 | && (get_elf_backend_data (abfd) |
| 750 | ->elf_backend_can_make_relative_eh_frame |
| 751 | (abfd, info, sec))) |
| 752 | { |
| 753 | if ((cie->fde_encoding & 0xf0) == DW_EH_PE_absptr) |
| 754 | cie->make_relative = 1; |
| 755 | /* If the CIE doesn't already have an 'R' entry, it's fairly |
| 756 | easy to add one, provided that there's no aligned data |
| 757 | after the augmentation string. */ |
| 758 | else if (cie->fde_encoding == DW_EH_PE_omit |
| 759 | && (cie->per_encoding & 0xf0) != DW_EH_PE_aligned) |
| 760 | { |
| 761 | if (*cie->augmentation == 0) |
| 762 | this_inf->add_augmentation_size = 1; |
| 763 | this_inf->add_fde_encoding = 1; |
| 764 | cie->make_relative = 1; |
| 765 | } |
| 766 | } |
| 767 | |
| 768 | if (info->shared |
| 769 | && (get_elf_backend_data (abfd) |
| 770 | ->elf_backend_can_make_lsda_relative_eh_frame |
| 771 | (abfd, info, sec)) |
| 772 | && (cie->lsda_encoding & 0xf0) == DW_EH_PE_absptr) |
| 773 | cie->make_lsda_relative = 1; |
| 774 | |
| 775 | /* If FDE encoding was not specified, it defaults to |
| 776 | DW_EH_absptr. */ |
| 777 | if (cie->fde_encoding == DW_EH_PE_omit) |
| 778 | cie->fde_encoding = DW_EH_PE_absptr; |
| 779 | |
| 780 | initial_insn_length = end - buf; |
| 781 | if (initial_insn_length <= sizeof (cie->initial_instructions)) |
| 782 | { |
| 783 | cie->initial_insn_length = initial_insn_length; |
| 784 | memcpy (cie->initial_instructions, buf, initial_insn_length); |
| 785 | } |
| 786 | insns = buf; |
| 787 | buf += initial_insn_length; |
| 788 | ENSURE_NO_RELOCS (buf); |
| 789 | } |
| 790 | else |
| 791 | { |
| 792 | /* Find the corresponding CIE. */ |
| 793 | unsigned int cie_offset = this_inf->offset + 4 - hdr_id; |
| 794 | for (ecie = ecies; ecie < ecies + ecie_count; ++ecie) |
| 795 | if (cie_offset == ecie->offset) |
| 796 | break; |
| 797 | |
| 798 | /* Ensure this FDE references one of the CIEs in this input |
| 799 | section. */ |
| 800 | REQUIRE (ecie != ecies + ecie_count); |
| 801 | cie = &ecie->cie; |
| 802 | |
| 803 | ENSURE_NO_RELOCS (buf); |
| 804 | REQUIRE (GET_RELOC (buf)); |
| 805 | |
| 806 | if ((*reloc_symbol_deleted_p) (buf - ehbuf, cookie)) |
| 807 | /* This is a FDE against a discarded section. It should |
| 808 | be deleted. */ |
| 809 | this_inf->removed = 1; |
| 810 | else |
| 811 | { |
| 812 | if (info->shared |
| 813 | && (((cie->fde_encoding & 0xf0) == DW_EH_PE_absptr |
| 814 | && cie->make_relative == 0) |
| 815 | || (cie->fde_encoding & 0xf0) == DW_EH_PE_aligned)) |
| 816 | { |
| 817 | /* If a shared library uses absolute pointers |
| 818 | which we cannot turn into PC relative, |
| 819 | don't create the binary search table, |
| 820 | since it is affected by runtime relocations. */ |
| 821 | hdr_info->table = FALSE; |
| 822 | (*info->callbacks->einfo) |
| 823 | (_("%P: fde encoding in %B(%A) prevents .eh_frame_hdr" |
| 824 | " table being created.\n"), abfd, sec); |
| 825 | } |
| 826 | ecie->usage_count++; |
| 827 | hdr_info->fde_count++; |
| 828 | this_inf->cie_inf = (void *) (ecie - ecies); |
| 829 | } |
| 830 | |
| 831 | /* Skip the initial location and address range. */ |
| 832 | start = buf; |
| 833 | length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size); |
| 834 | REQUIRE (skip_bytes (&buf, end, 2 * length)); |
| 835 | |
| 836 | /* Skip the augmentation size, if present. */ |
| 837 | if (cie->augmentation[0] == 'z') |
| 838 | REQUIRE (read_uleb128 (&buf, end, &length)); |
| 839 | else |
| 840 | length = 0; |
| 841 | |
| 842 | /* Of the supported augmentation characters above, only 'L' |
| 843 | adds augmentation data to the FDE. This code would need to |
| 844 | be adjusted if any future augmentations do the same thing. */ |
| 845 | if (cie->lsda_encoding != DW_EH_PE_omit) |
| 846 | { |
| 847 | this_inf->lsda_offset = buf - start; |
| 848 | /* If there's no 'z' augmentation, we don't know where the |
| 849 | CFA insns begin. Assume no padding. */ |
| 850 | if (cie->augmentation[0] != 'z') |
| 851 | length = end - buf; |
| 852 | } |
| 853 | |
| 854 | /* Skip over the augmentation data. */ |
| 855 | REQUIRE (skip_bytes (&buf, end, length)); |
| 856 | insns = buf; |
| 857 | |
| 858 | buf = last_fde + 4 + hdr_length; |
| 859 | SKIP_RELOCS (buf); |
| 860 | } |
| 861 | |
| 862 | /* Try to interpret the CFA instructions and find the first |
| 863 | padding nop. Shrink this_inf's size so that it doesn't |
| 864 | include the padding. */ |
| 865 | length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size); |
| 866 | set_loc_count = 0; |
| 867 | insns_end = skip_non_nops (insns, end, length, &set_loc_count); |
| 868 | /* If we don't understand the CFA instructions, we can't know |
| 869 | what needs to be adjusted there. */ |
| 870 | if (insns_end == NULL |
| 871 | /* For the time being we don't support DW_CFA_set_loc in |
| 872 | CIE instructions. */ |
| 873 | || (set_loc_count && this_inf->cie)) |
| 874 | goto free_no_table; |
| 875 | this_inf->size -= end - insns_end; |
| 876 | if (insns_end != end && this_inf->cie) |
| 877 | { |
| 878 | cie->initial_insn_length -= end - insns_end; |
| 879 | cie->length -= end - insns_end; |
| 880 | } |
| 881 | if (set_loc_count |
| 882 | && ((cie->fde_encoding & 0xf0) == DW_EH_PE_pcrel |
| 883 | || cie->make_relative)) |
| 884 | { |
| 885 | unsigned int cnt; |
| 886 | bfd_byte *p; |
| 887 | |
| 888 | this_inf->set_loc = bfd_malloc ((set_loc_count + 1) |
| 889 | * sizeof (unsigned int)); |
| 890 | REQUIRE (this_inf->set_loc); |
| 891 | this_inf->set_loc[0] = set_loc_count; |
| 892 | p = insns; |
| 893 | cnt = 0; |
| 894 | while (p < end) |
| 895 | { |
| 896 | if (*p == DW_CFA_set_loc) |
| 897 | this_inf->set_loc[++cnt] = p + 1 - start; |
| 898 | REQUIRE (skip_cfa_op (&p, end, length)); |
| 899 | } |
| 900 | } |
| 901 | |
| 902 | this_inf->fde_encoding = cie->fde_encoding; |
| 903 | this_inf->lsda_encoding = cie->lsda_encoding; |
| 904 | sec_info->count++; |
| 905 | } |
| 906 | |
| 907 | elf_section_data (sec)->sec_info = sec_info; |
| 908 | sec->sec_info_type = ELF_INFO_TYPE_EH_FRAME; |
| 909 | |
| 910 | /* Look at all CIEs in this section and determine which can be |
| 911 | removed as unused, which can be merged with previous duplicate |
| 912 | CIEs and which need to be kept. */ |
| 913 | for (ecie = ecies; ecie < ecies + ecie_count; ++ecie) |
| 914 | { |
| 915 | if (ecie->usage_count == 0) |
| 916 | { |
| 917 | sec_info->entry[ecie->entry].removed = 1; |
| 918 | continue; |
| 919 | } |
| 920 | ecie->cie.output_sec = sec->output_section; |
| 921 | ecie->cie.cie_inf = sec_info->entry + ecie->entry; |
| 922 | cie_compute_hash (&ecie->cie); |
| 923 | if (hdr_info->cies != NULL) |
| 924 | { |
| 925 | void **loc = htab_find_slot_with_hash (hdr_info->cies, &ecie->cie, |
| 926 | ecie->cie.hash, INSERT); |
| 927 | if (loc != NULL) |
| 928 | { |
| 929 | if (*loc != HTAB_EMPTY_ENTRY) |
| 930 | { |
| 931 | sec_info->entry[ecie->entry].removed = 1; |
| 932 | ecie->cie.cie_inf = ((struct cie *) *loc)->cie_inf; |
| 933 | continue; |
| 934 | } |
| 935 | |
| 936 | *loc = malloc (sizeof (struct cie)); |
| 937 | if (*loc == NULL) |
| 938 | *loc = HTAB_DELETED_ENTRY; |
| 939 | else |
| 940 | memcpy (*loc, &ecie->cie, sizeof (struct cie)); |
| 941 | } |
| 942 | } |
| 943 | ecie->cie.cie_inf->make_relative = ecie->cie.make_relative; |
| 944 | ecie->cie.cie_inf->make_lsda_relative = ecie->cie.make_lsda_relative; |
| 945 | ecie->cie.cie_inf->per_encoding_relative |
| 946 | = (ecie->cie.per_encoding & 0x70) == DW_EH_PE_pcrel; |
| 947 | } |
| 948 | |
| 949 | /* Ok, now we can assign new offsets. */ |
| 950 | offset = 0; |
| 951 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) |
| 952 | if (!ent->removed) |
| 953 | { |
| 954 | if (!ent->cie) |
| 955 | { |
| 956 | ecie = ecies + (bfd_hostptr_t) ent->cie_inf; |
| 957 | ent->cie_inf = ecie->cie.cie_inf; |
| 958 | } |
| 959 | ent->new_offset = offset; |
| 960 | offset += size_of_output_cie_fde (ent, ptr_size); |
| 961 | } |
| 962 | |
| 963 | /* Resize the sec as needed. */ |
| 964 | sec->rawsize = sec->size; |
| 965 | sec->size = offset; |
| 966 | |
| 967 | free (ehbuf); |
| 968 | if (ecies) |
| 969 | free (ecies); |
| 970 | return offset != sec->rawsize; |
| 971 | |
| 972 | free_no_table: |
| 973 | (*info->callbacks->einfo) |
| 974 | (_("%P: error in %B(%A); no .eh_frame_hdr table will be created.\n"), |
| 975 | abfd, sec); |
| 976 | if (ehbuf) |
| 977 | free (ehbuf); |
| 978 | if (sec_info) |
| 979 | free (sec_info); |
| 980 | if (ecies) |
| 981 | free (ecies); |
| 982 | hdr_info->table = FALSE; |
| 983 | return FALSE; |
| 984 | |
| 985 | #undef REQUIRE |
| 986 | } |
| 987 | |
| 988 | /* This function is called for .eh_frame_hdr section after |
| 989 | _bfd_elf_discard_section_eh_frame has been called on all .eh_frame |
| 990 | input sections. It finalizes the size of .eh_frame_hdr section. */ |
| 991 | |
| 992 | bfd_boolean |
| 993 | _bfd_elf_discard_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
| 994 | { |
| 995 | struct elf_link_hash_table *htab; |
| 996 | struct eh_frame_hdr_info *hdr_info; |
| 997 | asection *sec; |
| 998 | |
| 999 | htab = elf_hash_table (info); |
| 1000 | hdr_info = &htab->eh_info; |
| 1001 | |
| 1002 | if (hdr_info->cies != NULL) |
| 1003 | { |
| 1004 | htab_delete (hdr_info->cies); |
| 1005 | hdr_info->cies = NULL; |
| 1006 | } |
| 1007 | |
| 1008 | sec = hdr_info->hdr_sec; |
| 1009 | if (sec == NULL) |
| 1010 | return FALSE; |
| 1011 | |
| 1012 | sec->size = EH_FRAME_HDR_SIZE; |
| 1013 | if (hdr_info->table) |
| 1014 | sec->size += 4 + hdr_info->fde_count * 8; |
| 1015 | |
| 1016 | elf_tdata (abfd)->eh_frame_hdr = sec; |
| 1017 | return TRUE; |
| 1018 | } |
| 1019 | |
| 1020 | /* This function is called from size_dynamic_sections. |
| 1021 | It needs to decide whether .eh_frame_hdr should be output or not, |
| 1022 | because when the dynamic symbol table has been sized it is too late |
| 1023 | to strip sections. */ |
| 1024 | |
| 1025 | bfd_boolean |
| 1026 | _bfd_elf_maybe_strip_eh_frame_hdr (struct bfd_link_info *info) |
| 1027 | { |
| 1028 | asection *o; |
| 1029 | bfd *abfd; |
| 1030 | struct elf_link_hash_table *htab; |
| 1031 | struct eh_frame_hdr_info *hdr_info; |
| 1032 | |
| 1033 | htab = elf_hash_table (info); |
| 1034 | hdr_info = &htab->eh_info; |
| 1035 | if (hdr_info->hdr_sec == NULL) |
| 1036 | return TRUE; |
| 1037 | |
| 1038 | if (bfd_is_abs_section (hdr_info->hdr_sec->output_section)) |
| 1039 | { |
| 1040 | hdr_info->hdr_sec = NULL; |
| 1041 | return TRUE; |
| 1042 | } |
| 1043 | |
| 1044 | abfd = NULL; |
| 1045 | if (info->eh_frame_hdr) |
| 1046 | for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link_next) |
| 1047 | { |
| 1048 | /* Count only sections which have at least a single CIE or FDE. |
| 1049 | There cannot be any CIE or FDE <= 8 bytes. */ |
| 1050 | o = bfd_get_section_by_name (abfd, ".eh_frame"); |
| 1051 | if (o && o->size > 8 && !bfd_is_abs_section (o->output_section)) |
| 1052 | break; |
| 1053 | } |
| 1054 | |
| 1055 | if (abfd == NULL) |
| 1056 | { |
| 1057 | hdr_info->hdr_sec->flags |= SEC_EXCLUDE; |
| 1058 | hdr_info->hdr_sec = NULL; |
| 1059 | return TRUE; |
| 1060 | } |
| 1061 | |
| 1062 | hdr_info->table = TRUE; |
| 1063 | return TRUE; |
| 1064 | } |
| 1065 | |
| 1066 | /* Adjust an address in the .eh_frame section. Given OFFSET within |
| 1067 | SEC, this returns the new offset in the adjusted .eh_frame section, |
| 1068 | or -1 if the address refers to a CIE/FDE which has been removed |
| 1069 | or to offset with dynamic relocation which is no longer needed. */ |
| 1070 | |
| 1071 | bfd_vma |
| 1072 | _bfd_elf_eh_frame_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, |
| 1073 | struct bfd_link_info *info, |
| 1074 | asection *sec, |
| 1075 | bfd_vma offset) |
| 1076 | { |
| 1077 | struct eh_frame_sec_info *sec_info; |
| 1078 | struct elf_link_hash_table *htab; |
| 1079 | struct eh_frame_hdr_info *hdr_info; |
| 1080 | unsigned int lo, hi, mid; |
| 1081 | |
| 1082 | if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) |
| 1083 | return offset; |
| 1084 | sec_info = elf_section_data (sec)->sec_info; |
| 1085 | |
| 1086 | if (offset >= sec->rawsize) |
| 1087 | return offset - sec->rawsize + sec->size; |
| 1088 | |
| 1089 | htab = elf_hash_table (info); |
| 1090 | hdr_info = &htab->eh_info; |
| 1091 | if (hdr_info->offsets_adjusted) |
| 1092 | offset += sec->output_offset; |
| 1093 | |
| 1094 | lo = 0; |
| 1095 | hi = sec_info->count; |
| 1096 | mid = 0; |
| 1097 | while (lo < hi) |
| 1098 | { |
| 1099 | mid = (lo + hi) / 2; |
| 1100 | if (offset < sec_info->entry[mid].offset) |
| 1101 | hi = mid; |
| 1102 | else if (offset |
| 1103 | >= sec_info->entry[mid].offset + sec_info->entry[mid].size) |
| 1104 | lo = mid + 1; |
| 1105 | else |
| 1106 | break; |
| 1107 | } |
| 1108 | |
| 1109 | BFD_ASSERT (lo < hi); |
| 1110 | |
| 1111 | /* FDE or CIE was removed. */ |
| 1112 | if (sec_info->entry[mid].removed) |
| 1113 | return (bfd_vma) -1; |
| 1114 | |
| 1115 | /* If converting to DW_EH_PE_pcrel, there will be no need for run-time |
| 1116 | relocation against FDE's initial_location field. */ |
| 1117 | if (!sec_info->entry[mid].cie |
| 1118 | && sec_info->entry[mid].cie_inf->make_relative |
| 1119 | && offset == sec_info->entry[mid].offset + 8) |
| 1120 | return (bfd_vma) -2; |
| 1121 | |
| 1122 | /* If converting LSDA pointers to DW_EH_PE_pcrel, there will be no need |
| 1123 | for run-time relocation against LSDA field. */ |
| 1124 | if (!sec_info->entry[mid].cie |
| 1125 | && sec_info->entry[mid].cie_inf->make_lsda_relative |
| 1126 | && (offset == (sec_info->entry[mid].offset + 8 |
| 1127 | + sec_info->entry[mid].lsda_offset)) |
| 1128 | && (sec_info->entry[mid].cie_inf->need_lsda_relative |
| 1129 | || !hdr_info->offsets_adjusted)) |
| 1130 | { |
| 1131 | sec_info->entry[mid].cie_inf->need_lsda_relative = 1; |
| 1132 | return (bfd_vma) -2; |
| 1133 | } |
| 1134 | |
| 1135 | /* If converting to DW_EH_PE_pcrel, there will be no need for run-time |
| 1136 | relocation against DW_CFA_set_loc's arguments. */ |
| 1137 | if (sec_info->entry[mid].set_loc |
| 1138 | && (sec_info->entry[mid].cie |
| 1139 | ? sec_info->entry[mid].make_relative |
| 1140 | : sec_info->entry[mid].cie_inf->make_relative) |
| 1141 | && (offset >= sec_info->entry[mid].offset + 8 |
| 1142 | + sec_info->entry[mid].set_loc[1])) |
| 1143 | { |
| 1144 | unsigned int cnt; |
| 1145 | |
| 1146 | for (cnt = 1; cnt <= sec_info->entry[mid].set_loc[0]; cnt++) |
| 1147 | if (offset == sec_info->entry[mid].offset + 8 |
| 1148 | + sec_info->entry[mid].set_loc[cnt]) |
| 1149 | return (bfd_vma) -2; |
| 1150 | } |
| 1151 | |
| 1152 | if (hdr_info->offsets_adjusted) |
| 1153 | offset -= sec->output_offset; |
| 1154 | /* Any new augmentation bytes go before the first relocation. */ |
| 1155 | return (offset + sec_info->entry[mid].new_offset |
| 1156 | - sec_info->entry[mid].offset |
| 1157 | + extra_augmentation_string_bytes (sec_info->entry + mid) |
| 1158 | + extra_augmentation_data_bytes (sec_info->entry + mid)); |
| 1159 | } |
| 1160 | |
| 1161 | /* Write out .eh_frame section. This is called with the relocated |
| 1162 | contents. */ |
| 1163 | |
| 1164 | bfd_boolean |
| 1165 | _bfd_elf_write_section_eh_frame (bfd *abfd, |
| 1166 | struct bfd_link_info *info, |
| 1167 | asection *sec, |
| 1168 | bfd_byte *contents) |
| 1169 | { |
| 1170 | struct eh_frame_sec_info *sec_info; |
| 1171 | struct elf_link_hash_table *htab; |
| 1172 | struct eh_frame_hdr_info *hdr_info; |
| 1173 | unsigned int ptr_size; |
| 1174 | struct eh_cie_fde *ent; |
| 1175 | |
| 1176 | if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) |
| 1177 | return bfd_set_section_contents (abfd, sec->output_section, contents, |
| 1178 | sec->output_offset, sec->size); |
| 1179 | |
| 1180 | ptr_size = (get_elf_backend_data (abfd) |
| 1181 | ->elf_backend_eh_frame_address_size (abfd, sec)); |
| 1182 | BFD_ASSERT (ptr_size != 0); |
| 1183 | |
| 1184 | sec_info = elf_section_data (sec)->sec_info; |
| 1185 | htab = elf_hash_table (info); |
| 1186 | hdr_info = &htab->eh_info; |
| 1187 | |
| 1188 | /* First convert all offsets to output section offsets, so that a |
| 1189 | CIE offset is valid if the CIE is used by a FDE from some other |
| 1190 | section. This can happen when duplicate CIEs are deleted in |
| 1191 | _bfd_elf_discard_section_eh_frame. We do all sections here because |
| 1192 | this function might not be called on sections in the same order as |
| 1193 | _bfd_elf_discard_section_eh_frame. */ |
| 1194 | if (!hdr_info->offsets_adjusted) |
| 1195 | { |
| 1196 | bfd *ibfd; |
| 1197 | asection *eh; |
| 1198 | struct eh_frame_sec_info *eh_inf; |
| 1199 | |
| 1200 | for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next) |
| 1201 | { |
| 1202 | if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour |
| 1203 | || (ibfd->flags & DYNAMIC) != 0) |
| 1204 | continue; |
| 1205 | |
| 1206 | eh = bfd_get_section_by_name (ibfd, ".eh_frame"); |
| 1207 | if (eh == NULL || eh->sec_info_type != ELF_INFO_TYPE_EH_FRAME) |
| 1208 | continue; |
| 1209 | |
| 1210 | eh_inf = elf_section_data (eh)->sec_info; |
| 1211 | for (ent = eh_inf->entry; ent < eh_inf->entry + eh_inf->count; ++ent) |
| 1212 | { |
| 1213 | ent->offset += eh->output_offset; |
| 1214 | ent->new_offset += eh->output_offset; |
| 1215 | } |
| 1216 | } |
| 1217 | hdr_info->offsets_adjusted = TRUE; |
| 1218 | } |
| 1219 | |
| 1220 | if (hdr_info->table && hdr_info->array == NULL) |
| 1221 | hdr_info->array |
| 1222 | = bfd_malloc (hdr_info->fde_count * sizeof(*hdr_info->array)); |
| 1223 | if (hdr_info->array == NULL) |
| 1224 | hdr_info = NULL; |
| 1225 | |
| 1226 | /* The new offsets can be bigger or smaller than the original offsets. |
| 1227 | We therefore need to make two passes over the section: one backward |
| 1228 | pass to move entries up and one forward pass to move entries down. |
| 1229 | The two passes won't interfere with each other because entries are |
| 1230 | not reordered */ |
| 1231 | for (ent = sec_info->entry + sec_info->count; ent-- != sec_info->entry;) |
| 1232 | if (!ent->removed && ent->new_offset > ent->offset) |
| 1233 | memmove (contents + ent->new_offset - sec->output_offset, |
| 1234 | contents + ent->offset - sec->output_offset, ent->size); |
| 1235 | |
| 1236 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) |
| 1237 | if (!ent->removed && ent->new_offset < ent->offset) |
| 1238 | memmove (contents + ent->new_offset - sec->output_offset, |
| 1239 | contents + ent->offset - sec->output_offset, ent->size); |
| 1240 | |
| 1241 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) |
| 1242 | { |
| 1243 | unsigned char *buf, *end; |
| 1244 | unsigned int new_size; |
| 1245 | |
| 1246 | if (ent->removed) |
| 1247 | continue; |
| 1248 | |
| 1249 | if (ent->size == 4) |
| 1250 | { |
| 1251 | /* Any terminating FDE must be at the end of the section. */ |
| 1252 | BFD_ASSERT (ent == sec_info->entry + sec_info->count - 1); |
| 1253 | continue; |
| 1254 | } |
| 1255 | |
| 1256 | buf = contents + ent->new_offset - sec->output_offset; |
| 1257 | end = buf + ent->size; |
| 1258 | new_size = size_of_output_cie_fde (ent, ptr_size); |
| 1259 | |
| 1260 | /* Update the size. It may be shrinked. */ |
| 1261 | bfd_put_32 (abfd, new_size - 4, buf); |
| 1262 | |
| 1263 | /* Filling the extra bytes with DW_CFA_nops. */ |
| 1264 | if (new_size != ent->size) |
| 1265 | memset (end, 0, new_size - ent->size); |
| 1266 | |
| 1267 | if (ent->cie) |
| 1268 | { |
| 1269 | /* CIE */ |
| 1270 | if (ent->make_relative |
| 1271 | || ent->need_lsda_relative |
| 1272 | || ent->per_encoding_relative) |
| 1273 | { |
| 1274 | char *aug; |
| 1275 | unsigned int action, extra_string, extra_data; |
| 1276 | unsigned int per_width, per_encoding; |
| 1277 | |
| 1278 | /* Need to find 'R' or 'L' augmentation's argument and modify |
| 1279 | DW_EH_PE_* value. */ |
| 1280 | action = ((ent->make_relative ? 1 : 0) |
| 1281 | | (ent->need_lsda_relative ? 2 : 0) |
| 1282 | | (ent->per_encoding_relative ? 4 : 0)); |
| 1283 | extra_string = extra_augmentation_string_bytes (ent); |
| 1284 | extra_data = extra_augmentation_data_bytes (ent); |
| 1285 | |
| 1286 | /* Skip length, id and version. */ |
| 1287 | buf += 9; |
| 1288 | aug = (char *) buf; |
| 1289 | buf += strlen (aug) + 1; |
| 1290 | skip_leb128 (&buf, end); |
| 1291 | skip_leb128 (&buf, end); |
| 1292 | skip_leb128 (&buf, end); |
| 1293 | if (*aug == 'z') |
| 1294 | { |
| 1295 | /* The uleb128 will always be a single byte for the kind |
| 1296 | of augmentation strings that we're prepared to handle. */ |
| 1297 | *buf++ += extra_data; |
| 1298 | aug++; |
| 1299 | } |
| 1300 | |
| 1301 | /* Make room for the new augmentation string and data bytes. */ |
| 1302 | memmove (buf + extra_string + extra_data, buf, end - buf); |
| 1303 | memmove (aug + extra_string, aug, buf - (bfd_byte *) aug); |
| 1304 | buf += extra_string; |
| 1305 | end += extra_string + extra_data; |
| 1306 | |
| 1307 | if (ent->add_augmentation_size) |
| 1308 | { |
| 1309 | *aug++ = 'z'; |
| 1310 | *buf++ = extra_data - 1; |
| 1311 | } |
| 1312 | if (ent->add_fde_encoding) |
| 1313 | { |
| 1314 | BFD_ASSERT (action & 1); |
| 1315 | *aug++ = 'R'; |
| 1316 | *buf++ = DW_EH_PE_pcrel; |
| 1317 | action &= ~1; |
| 1318 | } |
| 1319 | |
| 1320 | while (action) |
| 1321 | switch (*aug++) |
| 1322 | { |
| 1323 | case 'L': |
| 1324 | if (action & 2) |
| 1325 | { |
| 1326 | BFD_ASSERT (*buf == ent->lsda_encoding); |
| 1327 | *buf |= DW_EH_PE_pcrel; |
| 1328 | action &= ~2; |
| 1329 | } |
| 1330 | buf++; |
| 1331 | break; |
| 1332 | case 'P': |
| 1333 | per_encoding = *buf++; |
| 1334 | per_width = get_DW_EH_PE_width (per_encoding, ptr_size); |
| 1335 | BFD_ASSERT (per_width != 0); |
| 1336 | BFD_ASSERT (((per_encoding & 0x70) == DW_EH_PE_pcrel) |
| 1337 | == ent->per_encoding_relative); |
| 1338 | if ((per_encoding & 0xf0) == DW_EH_PE_aligned) |
| 1339 | buf = (contents |
| 1340 | + ((buf - contents + per_width - 1) |
| 1341 | & ~((bfd_size_type) per_width - 1))); |
| 1342 | if (action & 4) |
| 1343 | { |
| 1344 | bfd_vma val; |
| 1345 | |
| 1346 | val = read_value (abfd, buf, per_width, |
| 1347 | get_DW_EH_PE_signed (per_encoding)); |
| 1348 | val += ent->offset - ent->new_offset; |
| 1349 | val -= extra_string + extra_data; |
| 1350 | write_value (abfd, buf, val, per_width); |
| 1351 | action &= ~4; |
| 1352 | } |
| 1353 | buf += per_width; |
| 1354 | break; |
| 1355 | case 'R': |
| 1356 | if (action & 1) |
| 1357 | { |
| 1358 | BFD_ASSERT (*buf == ent->fde_encoding); |
| 1359 | *buf |= DW_EH_PE_pcrel; |
| 1360 | action &= ~1; |
| 1361 | } |
| 1362 | buf++; |
| 1363 | break; |
| 1364 | case 'S': |
| 1365 | break; |
| 1366 | default: |
| 1367 | BFD_FAIL (); |
| 1368 | } |
| 1369 | } |
| 1370 | } |
| 1371 | else |
| 1372 | { |
| 1373 | /* FDE */ |
| 1374 | bfd_vma value, address; |
| 1375 | unsigned int width; |
| 1376 | bfd_byte *start; |
| 1377 | |
| 1378 | /* Skip length. */ |
| 1379 | buf += 4; |
| 1380 | value = ent->new_offset + 4 - ent->cie_inf->new_offset; |
| 1381 | bfd_put_32 (abfd, value, buf); |
| 1382 | buf += 4; |
| 1383 | width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size); |
| 1384 | value = read_value (abfd, buf, width, |
| 1385 | get_DW_EH_PE_signed (ent->fde_encoding)); |
| 1386 | address = value; |
| 1387 | if (value) |
| 1388 | { |
| 1389 | switch (ent->fde_encoding & 0xf0) |
| 1390 | { |
| 1391 | case DW_EH_PE_indirect: |
| 1392 | case DW_EH_PE_textrel: |
| 1393 | BFD_ASSERT (hdr_info == NULL); |
| 1394 | break; |
| 1395 | case DW_EH_PE_datarel: |
| 1396 | { |
| 1397 | asection *got = bfd_get_section_by_name (abfd, ".got"); |
| 1398 | |
| 1399 | BFD_ASSERT (got != NULL); |
| 1400 | address += got->vma; |
| 1401 | } |
| 1402 | break; |
| 1403 | case DW_EH_PE_pcrel: |
| 1404 | value += ent->offset - ent->new_offset; |
| 1405 | address += sec->output_section->vma + ent->offset + 8; |
| 1406 | break; |
| 1407 | } |
| 1408 | if (ent->cie_inf->make_relative) |
| 1409 | value -= sec->output_section->vma + ent->new_offset + 8; |
| 1410 | write_value (abfd, buf, value, width); |
| 1411 | } |
| 1412 | |
| 1413 | start = buf; |
| 1414 | |
| 1415 | if (hdr_info) |
| 1416 | { |
| 1417 | hdr_info->array[hdr_info->array_count].initial_loc = address; |
| 1418 | hdr_info->array[hdr_info->array_count++].fde |
| 1419 | = sec->output_section->vma + ent->new_offset; |
| 1420 | } |
| 1421 | |
| 1422 | if ((ent->lsda_encoding & 0xf0) == DW_EH_PE_pcrel |
| 1423 | || ent->cie_inf->need_lsda_relative) |
| 1424 | { |
| 1425 | buf += ent->lsda_offset; |
| 1426 | width = get_DW_EH_PE_width (ent->lsda_encoding, ptr_size); |
| 1427 | value = read_value (abfd, buf, width, |
| 1428 | get_DW_EH_PE_signed (ent->lsda_encoding)); |
| 1429 | if (value) |
| 1430 | { |
| 1431 | if ((ent->lsda_encoding & 0xf0) == DW_EH_PE_pcrel) |
| 1432 | value += ent->offset - ent->new_offset; |
| 1433 | else if (ent->cie_inf->need_lsda_relative) |
| 1434 | value -= (sec->output_section->vma + ent->new_offset + 8 |
| 1435 | + ent->lsda_offset); |
| 1436 | write_value (abfd, buf, value, width); |
| 1437 | } |
| 1438 | } |
| 1439 | else if (ent->cie_inf->add_augmentation_size) |
| 1440 | { |
| 1441 | /* Skip the PC and length and insert a zero byte for the |
| 1442 | augmentation size. */ |
| 1443 | buf += width * 2; |
| 1444 | memmove (buf + 1, buf, end - buf); |
| 1445 | *buf = 0; |
| 1446 | } |
| 1447 | |
| 1448 | if (ent->set_loc) |
| 1449 | { |
| 1450 | /* Adjust DW_CFA_set_loc. */ |
| 1451 | unsigned int cnt, width; |
| 1452 | bfd_vma new_offset; |
| 1453 | |
| 1454 | width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size); |
| 1455 | new_offset = ent->new_offset + 8 |
| 1456 | + extra_augmentation_string_bytes (ent) |
| 1457 | + extra_augmentation_data_bytes (ent); |
| 1458 | |
| 1459 | for (cnt = 1; cnt <= ent->set_loc[0]; cnt++) |
| 1460 | { |
| 1461 | bfd_vma value; |
| 1462 | buf = start + ent->set_loc[cnt]; |
| 1463 | |
| 1464 | value = read_value (abfd, buf, width, |
| 1465 | get_DW_EH_PE_signed (ent->fde_encoding)); |
| 1466 | if (!value) |
| 1467 | continue; |
| 1468 | |
| 1469 | if ((ent->fde_encoding & 0xf0) == DW_EH_PE_pcrel) |
| 1470 | value += ent->offset + 8 - new_offset; |
| 1471 | if (ent->cie_inf->make_relative) |
| 1472 | value -= sec->output_section->vma + new_offset |
| 1473 | + ent->set_loc[cnt]; |
| 1474 | write_value (abfd, buf, value, width); |
| 1475 | } |
| 1476 | } |
| 1477 | } |
| 1478 | } |
| 1479 | |
| 1480 | /* We don't align the section to its section alignment since the |
| 1481 | runtime library only expects all CIE/FDE records aligned at |
| 1482 | the pointer size. _bfd_elf_discard_section_eh_frame should |
| 1483 | have padded CIE/FDE records to multiple of pointer size with |
| 1484 | size_of_output_cie_fde. */ |
| 1485 | if ((sec->size % ptr_size) != 0) |
| 1486 | abort (); |
| 1487 | |
| 1488 | return bfd_set_section_contents (abfd, sec->output_section, |
| 1489 | contents, (file_ptr) sec->output_offset, |
| 1490 | sec->size); |
| 1491 | } |
| 1492 | |
| 1493 | /* Helper function used to sort .eh_frame_hdr search table by increasing |
| 1494 | VMA of FDE initial location. */ |
| 1495 | |
| 1496 | static int |
| 1497 | vma_compare (const void *a, const void *b) |
| 1498 | { |
| 1499 | const struct eh_frame_array_ent *p = a; |
| 1500 | const struct eh_frame_array_ent *q = b; |
| 1501 | if (p->initial_loc > q->initial_loc) |
| 1502 | return 1; |
| 1503 | if (p->initial_loc < q->initial_loc) |
| 1504 | return -1; |
| 1505 | return 0; |
| 1506 | } |
| 1507 | |
| 1508 | /* Write out .eh_frame_hdr section. This must be called after |
| 1509 | _bfd_elf_write_section_eh_frame has been called on all input |
| 1510 | .eh_frame sections. |
| 1511 | .eh_frame_hdr format: |
| 1512 | ubyte version (currently 1) |
| 1513 | ubyte eh_frame_ptr_enc (DW_EH_PE_* encoding of pointer to start of |
| 1514 | .eh_frame section) |
| 1515 | ubyte fde_count_enc (DW_EH_PE_* encoding of total FDE count |
| 1516 | number (or DW_EH_PE_omit if there is no |
| 1517 | binary search table computed)) |
| 1518 | ubyte table_enc (DW_EH_PE_* encoding of binary search table, |
| 1519 | or DW_EH_PE_omit if not present. |
| 1520 | DW_EH_PE_datarel is using address of |
| 1521 | .eh_frame_hdr section start as base) |
| 1522 | [encoded] eh_frame_ptr (pointer to start of .eh_frame section) |
| 1523 | optionally followed by: |
| 1524 | [encoded] fde_count (total number of FDEs in .eh_frame section) |
| 1525 | fde_count x [encoded] initial_loc, fde |
| 1526 | (array of encoded pairs containing |
| 1527 | FDE initial_location field and FDE address, |
| 1528 | sorted by increasing initial_loc). */ |
| 1529 | |
| 1530 | bfd_boolean |
| 1531 | _bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
| 1532 | { |
| 1533 | struct elf_link_hash_table *htab; |
| 1534 | struct eh_frame_hdr_info *hdr_info; |
| 1535 | asection *sec; |
| 1536 | bfd_byte *contents; |
| 1537 | asection *eh_frame_sec; |
| 1538 | bfd_size_type size; |
| 1539 | bfd_boolean retval; |
| 1540 | bfd_vma encoded_eh_frame; |
| 1541 | |
| 1542 | htab = elf_hash_table (info); |
| 1543 | hdr_info = &htab->eh_info; |
| 1544 | sec = hdr_info->hdr_sec; |
| 1545 | if (sec == NULL) |
| 1546 | return TRUE; |
| 1547 | |
| 1548 | size = EH_FRAME_HDR_SIZE; |
| 1549 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) |
| 1550 | size += 4 + hdr_info->fde_count * 8; |
| 1551 | contents = bfd_malloc (size); |
| 1552 | if (contents == NULL) |
| 1553 | return FALSE; |
| 1554 | |
| 1555 | eh_frame_sec = bfd_get_section_by_name (abfd, ".eh_frame"); |
| 1556 | if (eh_frame_sec == NULL) |
| 1557 | { |
| 1558 | free (contents); |
| 1559 | return FALSE; |
| 1560 | } |
| 1561 | |
| 1562 | memset (contents, 0, EH_FRAME_HDR_SIZE); |
| 1563 | contents[0] = 1; /* Version. */ |
| 1564 | contents[1] = get_elf_backend_data (abfd)->elf_backend_encode_eh_address |
| 1565 | (abfd, info, eh_frame_sec, 0, sec, 4, |
| 1566 | &encoded_eh_frame); /* .eh_frame offset. */ |
| 1567 | |
| 1568 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) |
| 1569 | { |
| 1570 | contents[2] = DW_EH_PE_udata4; /* FDE count encoding. */ |
| 1571 | contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4; /* Search table enc. */ |
| 1572 | } |
| 1573 | else |
| 1574 | { |
| 1575 | contents[2] = DW_EH_PE_omit; |
| 1576 | contents[3] = DW_EH_PE_omit; |
| 1577 | } |
| 1578 | bfd_put_32 (abfd, encoded_eh_frame, contents + 4); |
| 1579 | |
| 1580 | if (contents[2] != DW_EH_PE_omit) |
| 1581 | { |
| 1582 | unsigned int i; |
| 1583 | |
| 1584 | bfd_put_32 (abfd, hdr_info->fde_count, contents + EH_FRAME_HDR_SIZE); |
| 1585 | qsort (hdr_info->array, hdr_info->fde_count, sizeof (*hdr_info->array), |
| 1586 | vma_compare); |
| 1587 | for (i = 0; i < hdr_info->fde_count; i++) |
| 1588 | { |
| 1589 | bfd_put_32 (abfd, |
| 1590 | hdr_info->array[i].initial_loc |
| 1591 | - sec->output_section->vma, |
| 1592 | contents + EH_FRAME_HDR_SIZE + i * 8 + 4); |
| 1593 | bfd_put_32 (abfd, |
| 1594 | hdr_info->array[i].fde - sec->output_section->vma, |
| 1595 | contents + EH_FRAME_HDR_SIZE + i * 8 + 8); |
| 1596 | } |
| 1597 | } |
| 1598 | |
| 1599 | retval = bfd_set_section_contents (abfd, sec->output_section, |
| 1600 | contents, (file_ptr) sec->output_offset, |
| 1601 | sec->size); |
| 1602 | free (contents); |
| 1603 | return retval; |
| 1604 | } |
| 1605 | |
| 1606 | /* Return the width of FDE addresses. This is the default implementation. */ |
| 1607 | |
| 1608 | unsigned int |
| 1609 | _bfd_elf_eh_frame_address_size (bfd *abfd, asection *sec ATTRIBUTE_UNUSED) |
| 1610 | { |
| 1611 | return elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64 ? 8 : 4; |
| 1612 | } |
| 1613 | |
| 1614 | /* Decide whether we can use a PC-relative encoding within the given |
| 1615 | EH frame section. This is the default implementation. */ |
| 1616 | |
| 1617 | bfd_boolean |
| 1618 | _bfd_elf_can_make_relative (bfd *input_bfd ATTRIBUTE_UNUSED, |
| 1619 | struct bfd_link_info *info ATTRIBUTE_UNUSED, |
| 1620 | asection *eh_frame_section ATTRIBUTE_UNUSED) |
| 1621 | { |
| 1622 | return TRUE; |
| 1623 | } |
| 1624 | |
| 1625 | /* Select an encoding for the given address. Preference is given to |
| 1626 | PC-relative addressing modes. */ |
| 1627 | |
| 1628 | bfd_byte |
| 1629 | _bfd_elf_encode_eh_address (bfd *abfd ATTRIBUTE_UNUSED, |
| 1630 | struct bfd_link_info *info ATTRIBUTE_UNUSED, |
| 1631 | asection *osec, bfd_vma offset, |
| 1632 | asection *loc_sec, bfd_vma loc_offset, |
| 1633 | bfd_vma *encoded) |
| 1634 | { |
| 1635 | *encoded = osec->vma + offset - |
| 1636 | (loc_sec->output_section->vma + loc_sec->output_offset + loc_offset); |
| 1637 | return DW_EH_PE_pcrel | DW_EH_PE_sdata4; |
| 1638 | } |