| 1 | /* |
| 2 | * bin-info.c |
| 3 | * |
| 4 | * Babeltrace - Executable and Shared Object Debug Info Reader |
| 5 | * |
| 6 | * Copyright 2015 Antoine Busque <abusque@efficios.com> |
| 7 | * |
| 8 | * Author: Antoine Busque <abusque@efficios.com> |
| 9 | * |
| 10 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 11 | * of this software and associated documentation files (the "Software"), to deal |
| 12 | * in the Software without restriction, including without limitation the rights |
| 13 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 14 | * copies of the Software, and to permit persons to whom the Software is |
| 15 | * furnished to do so, subject to the following conditions: |
| 16 | * |
| 17 | * The above copyright notice and this permission notice shall be included in |
| 18 | * all copies or substantial portions of the Software. |
| 19 | * |
| 20 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 21 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 22 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 23 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 24 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 25 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| 26 | * SOFTWARE. |
| 27 | */ |
| 28 | |
| 29 | #define BT_LOG_TAG "PLUGIN-CTF-LTTNG-UTILS-DEBUG-INFO-FLT-BIN-INFO" |
| 30 | #include "logging.h" |
| 31 | |
| 32 | #include <dwarf.h> |
| 33 | #include <errno.h> |
| 34 | #include <fcntl.h> |
| 35 | #include <inttypes.h> |
| 36 | #include <libgen.h> |
| 37 | #include <math.h> |
| 38 | #include <stdio.h> |
| 39 | #include <stdlib.h> |
| 40 | #include <string.h> |
| 41 | #include <unistd.h> |
| 42 | |
| 43 | #include <glib.h> |
| 44 | |
| 45 | #include <babeltrace/common-internal.h> |
| 46 | |
| 47 | #include "bin-info.h" |
| 48 | #include "crc32.h" |
| 49 | #include "dwarf.h" |
| 50 | #include "utils.h" |
| 51 | |
| 52 | /* |
| 53 | * An address printed in hex is at most 20 bytes (16 for 64-bits + |
| 54 | * leading 0x + optional leading '+' if addr is an offset + null |
| 55 | * character). |
| 56 | */ |
| 57 | #define ADDR_STR_LEN 20 |
| 58 | #define BUILD_ID_NOTE_NAME "GNU" |
| 59 | |
| 60 | BT_HIDDEN |
| 61 | int bin_info_init(void) |
| 62 | { |
| 63 | int ret = 0; |
| 64 | |
| 65 | if (elf_version(EV_CURRENT) == EV_NONE) { |
| 66 | BT_LOGD("ELF library initialization failed: %s.", |
| 67 | elf_errmsg(-1)); |
| 68 | ret = -1; |
| 69 | } |
| 70 | |
| 71 | return ret; |
| 72 | } |
| 73 | |
| 74 | BT_HIDDEN |
| 75 | struct bin_info *bin_info_create(struct bt_fd_cache *fdc, const char *path, |
| 76 | uint64_t low_addr, uint64_t memsz, bool is_pic, |
| 77 | const char *debug_info_dir, const char *target_prefix) |
| 78 | { |
| 79 | struct bin_info *bin = NULL; |
| 80 | |
| 81 | BT_ASSERT(fdc); |
| 82 | |
| 83 | if (!path) { |
| 84 | goto error; |
| 85 | } |
| 86 | |
| 87 | bin = g_new0(struct bin_info, 1); |
| 88 | if (!bin) { |
| 89 | goto error; |
| 90 | } |
| 91 | |
| 92 | if (target_prefix) { |
| 93 | bin->elf_path = g_build_filename(target_prefix, path, NULL); |
| 94 | } else { |
| 95 | bin->elf_path = g_strdup(path); |
| 96 | } |
| 97 | |
| 98 | if (!bin->elf_path) { |
| 99 | goto error; |
| 100 | } |
| 101 | |
| 102 | if (debug_info_dir) { |
| 103 | bin->debug_info_dir = g_strdup(debug_info_dir); |
| 104 | if (!bin->debug_info_dir) { |
| 105 | goto error; |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | bin->is_pic = is_pic; |
| 110 | bin->memsz = memsz; |
| 111 | bin->low_addr = low_addr; |
| 112 | bin->high_addr = bin->low_addr + bin->memsz; |
| 113 | bin->build_id = NULL; |
| 114 | bin->build_id_len = 0; |
| 115 | bin->file_build_id_matches = false; |
| 116 | bin->fd_cache = fdc; |
| 117 | |
| 118 | return bin; |
| 119 | |
| 120 | error: |
| 121 | bin_info_destroy(bin); |
| 122 | return NULL; |
| 123 | } |
| 124 | |
| 125 | BT_HIDDEN |
| 126 | void bin_info_destroy(struct bin_info *bin) |
| 127 | { |
| 128 | if (!bin) { |
| 129 | return; |
| 130 | } |
| 131 | |
| 132 | dwarf_end(bin->dwarf_info); |
| 133 | |
| 134 | g_free(bin->debug_info_dir); |
| 135 | g_free(bin->elf_path); |
| 136 | g_free(bin->dwarf_path); |
| 137 | g_free(bin->build_id); |
| 138 | g_free(bin->dbg_link_filename); |
| 139 | |
| 140 | elf_end(bin->elf_file); |
| 141 | |
| 142 | bt_fd_cache_put_handle(bin->fd_cache, bin->elf_handle); |
| 143 | bt_fd_cache_put_handle(bin->fd_cache, bin->dwarf_handle); |
| 144 | |
| 145 | g_free(bin); |
| 146 | } |
| 147 | |
| 148 | /** |
| 149 | * Initialize the ELF file for a given executable. |
| 150 | * |
| 151 | * @param bin bin_info instance |
| 152 | * @returns 0 on success, negative value on error. |
| 153 | */ |
| 154 | static |
| 155 | int bin_info_set_elf_file(struct bin_info *bin) |
| 156 | { |
| 157 | struct bt_fd_cache_handle *elf_handle = NULL; |
| 158 | Elf *elf_file = NULL; |
| 159 | |
| 160 | if (!bin) { |
| 161 | goto error; |
| 162 | } |
| 163 | |
| 164 | elf_handle = bt_fd_cache_get_handle(bin->fd_cache, bin->elf_path); |
| 165 | if (!elf_handle) { |
| 166 | BT_LOGD("Failed to open %s", bin->elf_path); |
| 167 | goto error; |
| 168 | } |
| 169 | bin->elf_handle = elf_handle; |
| 170 | |
| 171 | elf_file = elf_begin(bt_fd_cache_handle_get_fd(bin->elf_handle), |
| 172 | ELF_C_READ, NULL); |
| 173 | if (!elf_file) { |
| 174 | BT_LOGE("elf_begin failed: %s", elf_errmsg(-1)); |
| 175 | goto error; |
| 176 | } |
| 177 | |
| 178 | bin->elf_file = elf_file; |
| 179 | |
| 180 | if (elf_kind(elf_file) != ELF_K_ELF) { |
| 181 | BT_LOGE("Error: %s is not an ELF object", bin->elf_path); |
| 182 | goto error; |
| 183 | } |
| 184 | |
| 185 | return 0; |
| 186 | |
| 187 | error: |
| 188 | bt_fd_cache_put_handle(bin->fd_cache, elf_handle); |
| 189 | elf_end(elf_file); |
| 190 | return -1; |
| 191 | } |
| 192 | |
| 193 | /** |
| 194 | * From a note section data struct, check if it is a build id note. |
| 195 | * |
| 196 | * @param note_data Pointer to a note section |
| 197 | * |
| 198 | * @returns 1 on match, 0 if `buf` does not contain a |
| 199 | * valid build id note |
| 200 | */ |
| 201 | static |
| 202 | int is_build_id_note_section(Elf_Data *note_data) |
| 203 | { |
| 204 | size_t name_offset, desc_offset; |
| 205 | GElf_Nhdr note_header; |
| 206 | int ret = 0; |
| 207 | |
| 208 | /* |
| 209 | * Discard the return value as it contains the size of the note section |
| 210 | * and we don't need it. |
| 211 | */ |
| 212 | (void) gelf_getnote(note_data, 0, ¬e_header, &name_offset, |
| 213 | &desc_offset); |
| 214 | |
| 215 | /* |
| 216 | * Check the note name length. The name_sz field includes the |
| 217 | * terminating null byte. |
| 218 | */ |
| 219 | if (note_header.n_namesz != sizeof(BUILD_ID_NOTE_NAME)) { |
| 220 | goto invalid; |
| 221 | } |
| 222 | |
| 223 | /* Check the note type. */ |
| 224 | if (note_header.n_type != NT_GNU_BUILD_ID) { |
| 225 | goto invalid; |
| 226 | } |
| 227 | |
| 228 | /* Check the note name. */ |
| 229 | if (memcmp(note_data->d_buf + name_offset, BUILD_ID_NOTE_NAME, |
| 230 | note_header.n_namesz) != 0) { |
| 231 | goto invalid; |
| 232 | } |
| 233 | |
| 234 | ret = 1; |
| 235 | |
| 236 | invalid: |
| 237 | return ret; |
| 238 | } |
| 239 | |
| 240 | /** |
| 241 | * From a build id note section data struct, check if the build id it contains |
| 242 | * is identical to the build id passed as parameter. |
| 243 | * |
| 244 | * @param note_data Pointer to the file build id note section. |
| 245 | * @param build_id Pointer to a build id to compare to. |
| 246 | * @param build_id_len length of the build id. |
| 247 | * |
| 248 | * @returns 1 on match, 0 otherwise. |
| 249 | */ |
| 250 | static |
| 251 | int is_build_id_note_section_matching(Elf_Data *note_data, |
| 252 | uint8_t *build_id, size_t build_id_len) |
| 253 | { |
| 254 | size_t name_offset, desc_offset; |
| 255 | GElf_Nhdr note_header; |
| 256 | |
| 257 | if (build_id_len <= 0) { |
| 258 | goto end; |
| 259 | } |
| 260 | |
| 261 | /* |
| 262 | * Discard the return value as it contains the size of the note section |
| 263 | * and we don't need it. |
| 264 | */ |
| 265 | (void) gelf_getnote(note_data, 0, ¬e_header, &name_offset, |
| 266 | &desc_offset); |
| 267 | |
| 268 | /* |
| 269 | * Compare the binary build id with the supplied build id. |
| 270 | */ |
| 271 | if (memcmp(build_id, note_data->d_buf + desc_offset, |
| 272 | build_id_len) == 0) { |
| 273 | return 1; |
| 274 | } |
| 275 | end: |
| 276 | return 0; |
| 277 | } |
| 278 | |
| 279 | /** |
| 280 | * Checks if the build id stored in `bin` (bin->build_id) is matching the build |
| 281 | * id of the ondisk file (bin->elf_file). |
| 282 | * |
| 283 | * @param bin bin_info instance |
| 284 | * @param build_id build id to compare ot the on disk file |
| 285 | * @param build_id_len length of the build id |
| 286 | * |
| 287 | * @returns 1 on if the build id of stored in `bin` matches |
| 288 | * the build id of the ondisk file. |
| 289 | * 0 on if they are different or an error occured. |
| 290 | */ |
| 291 | static |
| 292 | int is_build_id_matching(struct bin_info *bin) |
| 293 | { |
| 294 | int ret, is_build_id, is_matching = 0; |
| 295 | Elf_Scn *curr_section = NULL, *next_section = NULL; |
| 296 | GElf_Shdr curr_section_hdr; |
| 297 | |
| 298 | if (!bin->build_id) { |
| 299 | goto error; |
| 300 | } |
| 301 | |
| 302 | /* Set ELF file if it hasn't been accessed yet. */ |
| 303 | if (!bin->elf_file) { |
| 304 | ret = bin_info_set_elf_file(bin); |
| 305 | if (ret) { |
| 306 | /* Failed to set ELF file. */ |
| 307 | goto error; |
| 308 | } |
| 309 | } |
| 310 | |
| 311 | next_section = elf_nextscn(bin->elf_file, curr_section); |
| 312 | if (!next_section) { |
| 313 | goto error; |
| 314 | } |
| 315 | |
| 316 | while (next_section) { |
| 317 | Elf_Data *note_data = NULL; |
| 318 | |
| 319 | curr_section = next_section; |
| 320 | next_section = elf_nextscn(bin->elf_file, curr_section); |
| 321 | |
| 322 | if (!gelf_getshdr(curr_section, &curr_section_hdr)) { |
| 323 | goto error; |
| 324 | } |
| 325 | |
| 326 | if (curr_section_hdr.sh_type != SHT_NOTE) { |
| 327 | continue; |
| 328 | } |
| 329 | |
| 330 | /* |
| 331 | * elf_getdata() translates the data to native byte order. |
| 332 | */ |
| 333 | note_data = elf_getdata(curr_section, NULL); |
| 334 | if (!note_data) { |
| 335 | goto error; |
| 336 | } |
| 337 | |
| 338 | /* Check if the note is of the build-id type. */ |
| 339 | is_build_id = is_build_id_note_section(note_data); |
| 340 | if (!is_build_id) { |
| 341 | continue; |
| 342 | } |
| 343 | |
| 344 | /* |
| 345 | * Compare the build id of the on-disk file and |
| 346 | * the build id recorded in the trace. |
| 347 | */ |
| 348 | is_matching = is_build_id_note_section_matching( |
| 349 | note_data, bin->build_id, bin->build_id_len); |
| 350 | if (!is_matching) { |
| 351 | break; |
| 352 | } |
| 353 | } |
| 354 | error: |
| 355 | return is_matching; |
| 356 | } |
| 357 | |
| 358 | BT_HIDDEN |
| 359 | int bin_info_set_build_id(struct bin_info *bin, uint8_t *build_id, |
| 360 | size_t build_id_len) |
| 361 | { |
| 362 | if (!bin || !build_id) { |
| 363 | goto error; |
| 364 | } |
| 365 | |
| 366 | /* Set the build id. */ |
| 367 | bin->build_id = g_new0(uint8_t, build_id_len); |
| 368 | if (!bin->build_id) { |
| 369 | goto error; |
| 370 | } |
| 371 | |
| 372 | memcpy(bin->build_id, build_id, build_id_len); |
| 373 | bin->build_id_len = build_id_len; |
| 374 | |
| 375 | /* |
| 376 | * Check if the file found on the file system has the same build id |
| 377 | * that what was recorded in the trace. |
| 378 | */ |
| 379 | bin->file_build_id_matches = is_build_id_matching(bin); |
| 380 | if (!bin->file_build_id_matches) { |
| 381 | BT_LOGD_STR("Supplied Build ID does not match Build ID of the " |
| 382 | "binary or library found on the file system."); |
| 383 | goto error; |
| 384 | } |
| 385 | |
| 386 | /* |
| 387 | * Reset the is_elf_only flag in case it had been set |
| 388 | * previously, because we might find separate debug info using |
| 389 | * the new build id information. |
| 390 | */ |
| 391 | bin->is_elf_only = false; |
| 392 | |
| 393 | return 0; |
| 394 | |
| 395 | error: |
| 396 | return -1; |
| 397 | } |
| 398 | |
| 399 | BT_HIDDEN |
| 400 | int bin_info_set_debug_link(struct bin_info *bin, const char *filename, |
| 401 | uint32_t crc) |
| 402 | { |
| 403 | if (!bin || !filename) { |
| 404 | goto error; |
| 405 | } |
| 406 | |
| 407 | bin->dbg_link_filename = g_strdup(filename); |
| 408 | if (!bin->dbg_link_filename) { |
| 409 | goto error; |
| 410 | } |
| 411 | |
| 412 | bin->dbg_link_crc = crc; |
| 413 | |
| 414 | /* |
| 415 | * Reset the is_elf_only flag in case it had been set |
| 416 | * previously, because we might find separate debug info using |
| 417 | * the new build id information. |
| 418 | */ |
| 419 | bin->is_elf_only = false; |
| 420 | |
| 421 | return 0; |
| 422 | |
| 423 | error: |
| 424 | |
| 425 | return -1; |
| 426 | } |
| 427 | |
| 428 | /** |
| 429 | * Tries to read DWARF info from the location given by path, and |
| 430 | * attach it to the given bin_info instance if it exists. |
| 431 | * |
| 432 | * @param bin bin_info instance for which to set DWARF info |
| 433 | * @param path Presumed location of the DWARF info |
| 434 | * @returns 0 on success, negative value on failure |
| 435 | */ |
| 436 | static |
| 437 | int bin_info_set_dwarf_info_from_path(struct bin_info *bin, char *path) |
| 438 | { |
| 439 | int ret = 0; |
| 440 | struct bt_fd_cache_handle *dwarf_handle = NULL; |
| 441 | struct bt_dwarf_cu *cu = NULL; |
| 442 | Dwarf *dwarf_info = NULL; |
| 443 | |
| 444 | if (!bin || !path) { |
| 445 | goto error; |
| 446 | } |
| 447 | |
| 448 | dwarf_handle = bt_fd_cache_get_handle(bin->fd_cache, path); |
| 449 | if (!dwarf_handle) { |
| 450 | goto error; |
| 451 | } |
| 452 | |
| 453 | dwarf_info = dwarf_begin(bt_fd_cache_handle_get_fd(dwarf_handle), |
| 454 | DWARF_C_READ); |
| 455 | if (!dwarf_info) { |
| 456 | goto error; |
| 457 | } |
| 458 | |
| 459 | /* |
| 460 | * Check if the dwarf info has any CU. If not, the |
| 461 | * executable's object file contains no DWARF info. |
| 462 | */ |
| 463 | cu = bt_dwarf_cu_create(dwarf_info); |
| 464 | if (!cu) { |
| 465 | goto error; |
| 466 | } |
| 467 | |
| 468 | ret = bt_dwarf_cu_next(cu); |
| 469 | if (ret) { |
| 470 | goto error; |
| 471 | } |
| 472 | |
| 473 | bin->dwarf_handle = dwarf_handle; |
| 474 | bin->dwarf_path = g_strdup(path); |
| 475 | if (!bin->dwarf_path) { |
| 476 | goto error; |
| 477 | } |
| 478 | bin->dwarf_info = dwarf_info; |
| 479 | free(cu); |
| 480 | |
| 481 | return 0; |
| 482 | |
| 483 | error: |
| 484 | bt_fd_cache_put_handle(bin->fd_cache, dwarf_handle); |
| 485 | dwarf_end(dwarf_info); |
| 486 | g_free(dwarf_info); |
| 487 | free(cu); |
| 488 | |
| 489 | return -1; |
| 490 | } |
| 491 | |
| 492 | /** |
| 493 | * Try to set the dwarf_info for a given bin_info instance via the |
| 494 | * build ID method. |
| 495 | * |
| 496 | * @param bin bin_info instance for which to retrieve the |
| 497 | * DWARF info via build ID |
| 498 | * @returns 0 on success (i.e. dwarf_info set), -1 on failure |
| 499 | */ |
| 500 | static |
| 501 | int bin_info_set_dwarf_info_build_id(struct bin_info *bin) |
| 502 | { |
| 503 | int i = 0, ret = 0; |
| 504 | char *path = NULL, *build_id_prefix_dir = NULL, *build_id_file = NULL; |
| 505 | const char *dbg_dir = NULL; |
| 506 | size_t build_id_char_len, build_id_suffix_char_len, build_id_file_len; |
| 507 | |
| 508 | if (!bin || !bin->build_id) { |
| 509 | goto error; |
| 510 | } |
| 511 | |
| 512 | dbg_dir = bin->debug_info_dir ? bin->debug_info_dir : DEFAULT_DEBUG_DIR; |
| 513 | |
| 514 | /* |
| 515 | * The prefix dir is the first byte of the build id, represented in |
| 516 | * lowercase hex as two characters per byte, +1 for '\0'. |
| 517 | */ |
| 518 | build_id_prefix_dir = g_new0(gchar, BUILD_ID_PREFIX_DIR_LEN + 1); |
| 519 | if (!build_id_prefix_dir) { |
| 520 | goto error; |
| 521 | } |
| 522 | g_snprintf(build_id_prefix_dir, BUILD_ID_PREFIX_DIR_LEN + 1, "%02x", bin->build_id[0]); |
| 523 | |
| 524 | /* |
| 525 | * The build id file is the remaining bytes of the build id, |
| 526 | * represented in lowercase hex, as two characters per byte. |
| 527 | */ |
| 528 | build_id_char_len = (2 * (bin->build_id_len - 1)); |
| 529 | |
| 530 | /* To which the build id suffix is added, +1 for '\0'. */ |
| 531 | build_id_suffix_char_len = strlen(BUILD_ID_SUFFIX) + 1; |
| 532 | |
| 533 | /* |
| 534 | * The resulting filename string is the concatenation of the |
| 535 | * hex build id and the suffix. |
| 536 | */ |
| 537 | build_id_file_len = build_id_char_len + build_id_suffix_char_len; |
| 538 | build_id_file = g_new0(gchar, build_id_file_len); |
| 539 | if (!build_id_file) { |
| 540 | goto error; |
| 541 | } |
| 542 | |
| 543 | /* |
| 544 | * For each byte, starting at offset 1, append two characters |
| 545 | * in lowercase hex. |
| 546 | */ |
| 547 | for (i = 1; i < bin->build_id_len; ++i) { |
| 548 | int path_idx = 2 * (i - 1); |
| 549 | |
| 550 | g_snprintf(&build_id_file[path_idx], 3, "%02x", bin->build_id[i]); |
| 551 | } |
| 552 | /* Append the suffix to the generated string, including the '\0'. */ |
| 553 | g_snprintf(&build_id_file[build_id_char_len], build_id_suffix_char_len, |
| 554 | BUILD_ID_SUFFIX); |
| 555 | |
| 556 | path = g_build_filename(dbg_dir, BUILD_ID_SUBDIR, build_id_prefix_dir, build_id_file, NULL); |
| 557 | if (!path) { |
| 558 | goto error; |
| 559 | } |
| 560 | |
| 561 | ret = bin_info_set_dwarf_info_from_path(bin, path); |
| 562 | if (ret) { |
| 563 | goto error; |
| 564 | } |
| 565 | |
| 566 | goto end; |
| 567 | |
| 568 | error: |
| 569 | ret = -1; |
| 570 | end: |
| 571 | g_free(build_id_prefix_dir); |
| 572 | g_free(build_id_file); |
| 573 | g_free(path); |
| 574 | |
| 575 | return ret; |
| 576 | } |
| 577 | |
| 578 | /** |
| 579 | * Tests whether the file located at path exists and has the expected |
| 580 | * checksum. |
| 581 | * |
| 582 | * This predicate is used when looking up separate debug info via the |
| 583 | * GNU debuglink method. The expected crc can be found .gnu_debuglink |
| 584 | * section in the original ELF file, along with the filename for the |
| 585 | * file containing the debug info. |
| 586 | * |
| 587 | * @param path Full path at which to look for the debug file |
| 588 | * @param crc Expected checksum for the debug file |
| 589 | * @returns 1 if the file exists and has the correct checksum, |
| 590 | * 0 otherwise |
| 591 | */ |
| 592 | static |
| 593 | int is_valid_debug_file(struct bin_info *bin, char *path, uint32_t crc) |
| 594 | { |
| 595 | int ret = 0; |
| 596 | struct bt_fd_cache_handle *debug_handle = NULL; |
| 597 | uint32_t _crc = 0; |
| 598 | |
| 599 | if (!path) { |
| 600 | goto end; |
| 601 | } |
| 602 | |
| 603 | debug_handle = bt_fd_cache_get_handle(bin->fd_cache, path); |
| 604 | if (!debug_handle) { |
| 605 | goto end; |
| 606 | } |
| 607 | |
| 608 | ret = crc32(bt_fd_cache_handle_get_fd(debug_handle), &_crc); |
| 609 | if (ret) { |
| 610 | ret = 0; |
| 611 | goto end; |
| 612 | } |
| 613 | |
| 614 | ret = (crc == _crc); |
| 615 | |
| 616 | end: |
| 617 | bt_fd_cache_put_handle(bin->fd_cache, debug_handle); |
| 618 | return ret; |
| 619 | } |
| 620 | |
| 621 | /** |
| 622 | * Try to set the dwarf_info for a given bin_info instance via the |
| 623 | * debug-link method. |
| 624 | * |
| 625 | * @param bin bin_info instance for which to retrieve the |
| 626 | * DWARF info via debug link |
| 627 | * @returns 0 on success (i.e. dwarf_info set), -1 on failure |
| 628 | */ |
| 629 | static |
| 630 | int bin_info_set_dwarf_info_debug_link(struct bin_info *bin) |
| 631 | { |
| 632 | int ret = 0; |
| 633 | const gchar *dbg_dir = NULL; |
| 634 | gchar *bin_dir = NULL, *path = NULL; |
| 635 | |
| 636 | if (!bin || !bin->dbg_link_filename) { |
| 637 | goto error; |
| 638 | } |
| 639 | |
| 640 | dbg_dir = bin->debug_info_dir ? bin->debug_info_dir : DEFAULT_DEBUG_DIR; |
| 641 | bin_dir = g_path_get_dirname(bin->elf_path); |
| 642 | |
| 643 | /* First look in the executable's dir */ |
| 644 | path = g_build_filename(bin_dir, bin->dbg_link_filename, NULL); |
| 645 | |
| 646 | if (is_valid_debug_file(bin, path, bin->dbg_link_crc)) { |
| 647 | goto found; |
| 648 | } |
| 649 | |
| 650 | /* If not found, look in .debug subdir */ |
| 651 | g_free(path); |
| 652 | path = g_build_filename(bin_dir, DEBUG_SUBDIR, bin->dbg_link_filename, NULL); |
| 653 | |
| 654 | if (is_valid_debug_file(bin, path, bin->dbg_link_crc)) { |
| 655 | goto found; |
| 656 | } |
| 657 | |
| 658 | /* Lastly, look under the global debug directory */ |
| 659 | g_free(path); |
| 660 | |
| 661 | path = g_build_filename(dbg_dir, bin_dir, bin->dbg_link_filename, NULL); |
| 662 | if (is_valid_debug_file(bin, path, bin->dbg_link_crc)) { |
| 663 | goto found; |
| 664 | } |
| 665 | |
| 666 | error: |
| 667 | ret = -1; |
| 668 | end: |
| 669 | g_free(bin_dir); |
| 670 | g_free(path); |
| 671 | |
| 672 | return ret; |
| 673 | |
| 674 | found: |
| 675 | ret = bin_info_set_dwarf_info_from_path(bin, path); |
| 676 | if (ret) { |
| 677 | goto error; |
| 678 | } |
| 679 | |
| 680 | goto end; |
| 681 | } |
| 682 | |
| 683 | /** |
| 684 | * Initialize the DWARF info for a given executable. |
| 685 | * |
| 686 | * @param bin bin_info instance |
| 687 | * @returns 0 on success, negative value on failure |
| 688 | */ |
| 689 | static |
| 690 | int bin_info_set_dwarf_info(struct bin_info *bin) |
| 691 | { |
| 692 | int ret = 0; |
| 693 | |
| 694 | if (!bin) { |
| 695 | ret = -1; |
| 696 | goto end; |
| 697 | } |
| 698 | |
| 699 | /* First try to set the DWARF info from the ELF file */ |
| 700 | ret = bin_info_set_dwarf_info_from_path(bin, bin->elf_path); |
| 701 | if (!ret) { |
| 702 | goto end; |
| 703 | } |
| 704 | |
| 705 | /* |
| 706 | * If that fails, try to find separate debug info via build ID |
| 707 | * and debug link. |
| 708 | */ |
| 709 | ret = bin_info_set_dwarf_info_build_id(bin); |
| 710 | if (!ret) { |
| 711 | goto end; |
| 712 | } |
| 713 | |
| 714 | ret = bin_info_set_dwarf_info_debug_link(bin); |
| 715 | if (!ret) { |
| 716 | goto end; |
| 717 | } |
| 718 | |
| 719 | end: |
| 720 | return ret; |
| 721 | } |
| 722 | |
| 723 | BT_HIDDEN |
| 724 | void source_location_destroy(struct source_location *src_loc) |
| 725 | { |
| 726 | if (!src_loc) { |
| 727 | return; |
| 728 | } |
| 729 | |
| 730 | free(src_loc->filename); |
| 731 | g_free(src_loc); |
| 732 | } |
| 733 | |
| 734 | /** |
| 735 | * Append a string representation of an address offset to an existing |
| 736 | * string. |
| 737 | * |
| 738 | * On success, the out parameter `result` will contain the base string |
| 739 | * followed by the offset string of the form "+0x1234". On failure, |
| 740 | * `result` remains unchanged. |
| 741 | * |
| 742 | * @param base_str The string to which to append an offset string |
| 743 | * @param low_addr The lower virtual memory address, the base from |
| 744 | * which the offset is computed |
| 745 | * @param high_addr The higher virtual memory address |
| 746 | * @param result Out parameter, the base string followed by the |
| 747 | * offset string |
| 748 | * @returns 0 on success, -1 on failure |
| 749 | */ |
| 750 | static |
| 751 | int bin_info_append_offset_str(const char *base_str, uint64_t low_addr, |
| 752 | uint64_t high_addr, char **result) |
| 753 | { |
| 754 | uint64_t offset; |
| 755 | char *_result = NULL; |
| 756 | |
| 757 | if (!base_str || !result) { |
| 758 | goto error; |
| 759 | } |
| 760 | |
| 761 | offset = high_addr - low_addr; |
| 762 | |
| 763 | _result = g_strdup_printf("%s+%#0" PRIx64, base_str, offset); |
| 764 | if (!_result) { |
| 765 | goto error; |
| 766 | } |
| 767 | *result = _result; |
| 768 | |
| 769 | return 0; |
| 770 | |
| 771 | error: |
| 772 | free(_result); |
| 773 | return -1; |
| 774 | } |
| 775 | |
| 776 | /** |
| 777 | * Try to find the symbol closest to an address within a given ELF |
| 778 | * section. |
| 779 | * |
| 780 | * Only function symbols are taken into account. The symbol's address |
| 781 | * must precede `addr`. A symbol with a closer address might exist |
| 782 | * after `addr` but is irrelevant because it cannot encompass `addr`. |
| 783 | * |
| 784 | * On success, if found, the out parameters `sym` and `shdr` are |
| 785 | * set. On failure or if none are found, they remain unchanged. |
| 786 | * |
| 787 | * @param scn ELF section in which to look for the address |
| 788 | * @param addr Virtual memory address for which to find the |
| 789 | * nearest function symbol |
| 790 | * @param sym Out parameter, the nearest function symbol |
| 791 | * @param shdr Out parameter, the section header for scn |
| 792 | * @returns 0 on success, -1 on failure |
| 793 | */ |
| 794 | static |
| 795 | int bin_info_get_nearest_symbol_from_section(Elf_Scn *scn, uint64_t addr, |
| 796 | GElf_Sym **sym, GElf_Shdr **shdr) |
| 797 | { |
| 798 | int i; |
| 799 | size_t symbol_count; |
| 800 | Elf_Data *data = NULL; |
| 801 | GElf_Shdr *_shdr = NULL; |
| 802 | GElf_Sym *nearest_sym = NULL; |
| 803 | |
| 804 | if (!scn || !sym || !shdr) { |
| 805 | goto error; |
| 806 | } |
| 807 | |
| 808 | _shdr = g_new0(GElf_Shdr, 1); |
| 809 | if (!_shdr) { |
| 810 | goto error; |
| 811 | } |
| 812 | |
| 813 | _shdr = gelf_getshdr(scn, _shdr); |
| 814 | if (!_shdr) { |
| 815 | goto error; |
| 816 | } |
| 817 | |
| 818 | if (_shdr->sh_type != SHT_SYMTAB) { |
| 819 | /* |
| 820 | * We are only interested in symbol table (symtab) |
| 821 | * sections, skip this one. |
| 822 | */ |
| 823 | goto end; |
| 824 | } |
| 825 | |
| 826 | data = elf_getdata(scn, NULL); |
| 827 | if (!data) { |
| 828 | goto error; |
| 829 | } |
| 830 | |
| 831 | symbol_count = _shdr->sh_size / _shdr->sh_entsize; |
| 832 | |
| 833 | for (i = 0; i < symbol_count; ++i) { |
| 834 | GElf_Sym *cur_sym = NULL; |
| 835 | |
| 836 | cur_sym = g_new0(GElf_Sym, 1); |
| 837 | if (!cur_sym) { |
| 838 | goto error; |
| 839 | } |
| 840 | cur_sym = gelf_getsym(data, i, cur_sym); |
| 841 | if (!cur_sym) { |
| 842 | goto error; |
| 843 | } |
| 844 | if (GELF_ST_TYPE(cur_sym->st_info) != STT_FUNC) { |
| 845 | /* We're only interested in the functions. */ |
| 846 | g_free(cur_sym); |
| 847 | continue; |
| 848 | } |
| 849 | |
| 850 | if (cur_sym->st_value <= addr && |
| 851 | (!nearest_sym || |
| 852 | cur_sym->st_value > nearest_sym->st_value)) { |
| 853 | g_free(nearest_sym); |
| 854 | nearest_sym = cur_sym; |
| 855 | } else { |
| 856 | g_free(cur_sym); |
| 857 | } |
| 858 | } |
| 859 | |
| 860 | end: |
| 861 | if (nearest_sym) { |
| 862 | *sym = nearest_sym; |
| 863 | *shdr = _shdr; |
| 864 | } else { |
| 865 | g_free(_shdr); |
| 866 | } |
| 867 | |
| 868 | return 0; |
| 869 | |
| 870 | error: |
| 871 | g_free(nearest_sym); |
| 872 | g_free(_shdr); |
| 873 | return -1; |
| 874 | } |
| 875 | |
| 876 | /** |
| 877 | * Get the name of the function containing a given address within an |
| 878 | * executable using ELF symbols. |
| 879 | * |
| 880 | * The function name is in fact the name of the nearest ELF symbol, |
| 881 | * followed by the offset in bytes between the address and the symbol |
| 882 | * (in hex), separated by a '+' character. |
| 883 | * |
| 884 | * If found, the out parameter `func_name` is set on success. On failure, |
| 885 | * it remains unchanged. |
| 886 | * |
| 887 | * @param bin bin_info instance for the executable containing |
| 888 | * the address |
| 889 | * @param addr Virtual memory address for which to find the |
| 890 | * function name |
| 891 | * @param func_name Out parameter, the function name |
| 892 | * @returns 0 on success, -1 on failure |
| 893 | */ |
| 894 | static |
| 895 | int bin_info_lookup_elf_function_name(struct bin_info *bin, uint64_t addr, |
| 896 | char **func_name) |
| 897 | { |
| 898 | /* |
| 899 | * TODO (possible optimisation): if an ELF has no symtab |
| 900 | * section, it has been stripped. Therefore, it would be wise |
| 901 | * to store a flag indicating the stripped status after the |
| 902 | * first iteration to prevent subsequent ones. |
| 903 | */ |
| 904 | int ret = 0; |
| 905 | Elf_Scn *scn = NULL; |
| 906 | GElf_Sym *sym = NULL; |
| 907 | GElf_Shdr *shdr = NULL; |
| 908 | char *sym_name = NULL; |
| 909 | |
| 910 | /* Set ELF file if it hasn't been accessed yet. */ |
| 911 | if (!bin->elf_file) { |
| 912 | ret = bin_info_set_elf_file(bin); |
| 913 | if (ret) { |
| 914 | /* Failed to set ELF file. */ |
| 915 | goto error; |
| 916 | } |
| 917 | } |
| 918 | |
| 919 | scn = elf_nextscn(bin->elf_file, scn); |
| 920 | if (!scn) { |
| 921 | goto error; |
| 922 | } |
| 923 | |
| 924 | while (scn && !sym) { |
| 925 | ret = bin_info_get_nearest_symbol_from_section( |
| 926 | scn, addr, &sym, &shdr); |
| 927 | if (ret) { |
| 928 | goto error; |
| 929 | } |
| 930 | |
| 931 | scn = elf_nextscn(bin->elf_file, scn); |
| 932 | } |
| 933 | |
| 934 | if (sym) { |
| 935 | sym_name = elf_strptr(bin->elf_file, shdr->sh_link, |
| 936 | sym->st_name); |
| 937 | if (!sym_name) { |
| 938 | goto error; |
| 939 | } |
| 940 | |
| 941 | ret = bin_info_append_offset_str(sym_name, sym->st_value, addr, |
| 942 | func_name); |
| 943 | if (ret) { |
| 944 | goto error; |
| 945 | } |
| 946 | } |
| 947 | |
| 948 | g_free(shdr); |
| 949 | g_free(sym); |
| 950 | return 0; |
| 951 | |
| 952 | error: |
| 953 | g_free(shdr); |
| 954 | g_free(sym); |
| 955 | return ret; |
| 956 | } |
| 957 | |
| 958 | /** |
| 959 | * Get the name of the function containing a given address within a |
| 960 | * given compile unit (CU). |
| 961 | * |
| 962 | * If found, the out parameter `func_name` is set on success. On |
| 963 | * failure, it remains unchanged. |
| 964 | * |
| 965 | * @param cu bt_dwarf_cu instance which may contain the address |
| 966 | * @param addr Virtual memory address for which to find the |
| 967 | * function name |
| 968 | * @param func_name Out parameter, the function name |
| 969 | * @returns 0 on success, -1 on failure |
| 970 | */ |
| 971 | static |
| 972 | int bin_info_lookup_cu_function_name(struct bt_dwarf_cu *cu, uint64_t addr, |
| 973 | char **func_name) |
| 974 | { |
| 975 | int ret = 0; |
| 976 | bool found = false; |
| 977 | struct bt_dwarf_die *die = NULL; |
| 978 | |
| 979 | if (!cu || !func_name) { |
| 980 | goto error; |
| 981 | } |
| 982 | |
| 983 | die = bt_dwarf_die_create(cu); |
| 984 | if (!die) { |
| 985 | goto error; |
| 986 | } |
| 987 | |
| 988 | while (bt_dwarf_die_next(die) == 0) { |
| 989 | int tag; |
| 990 | |
| 991 | ret = bt_dwarf_die_get_tag(die, &tag); |
| 992 | if (ret) { |
| 993 | goto error; |
| 994 | } |
| 995 | |
| 996 | if (tag == DW_TAG_subprogram) { |
| 997 | ret = bt_dwarf_die_contains_addr(die, addr, &found); |
| 998 | if (ret) { |
| 999 | goto error; |
| 1000 | } |
| 1001 | |
| 1002 | if (found) { |
| 1003 | break; |
| 1004 | } |
| 1005 | } |
| 1006 | } |
| 1007 | |
| 1008 | if (found) { |
| 1009 | uint64_t low_addr = 0; |
| 1010 | char *die_name = NULL; |
| 1011 | |
| 1012 | ret = bt_dwarf_die_get_name(die, &die_name); |
| 1013 | if (ret) { |
| 1014 | goto error; |
| 1015 | } |
| 1016 | |
| 1017 | ret = dwarf_lowpc(die->dwarf_die, &low_addr); |
| 1018 | if (ret) { |
| 1019 | free(die_name); |
| 1020 | goto error; |
| 1021 | } |
| 1022 | |
| 1023 | ret = bin_info_append_offset_str(die_name, low_addr, addr, |
| 1024 | func_name); |
| 1025 | free(die_name); |
| 1026 | if (ret) { |
| 1027 | goto error; |
| 1028 | } |
| 1029 | } |
| 1030 | |
| 1031 | bt_dwarf_die_destroy(die); |
| 1032 | return 0; |
| 1033 | |
| 1034 | error: |
| 1035 | bt_dwarf_die_destroy(die); |
| 1036 | return -1; |
| 1037 | } |
| 1038 | |
| 1039 | /** |
| 1040 | * Get the name of the function containing a given address within an |
| 1041 | * executable using DWARF debug info. |
| 1042 | * |
| 1043 | * If found, the out parameter `func_name` is set on success. On |
| 1044 | * failure, it remains unchanged. |
| 1045 | * |
| 1046 | * @param bin bin_info instance for the executable containing |
| 1047 | * the address |
| 1048 | * @param addr Virtual memory address for which to find the |
| 1049 | * function name |
| 1050 | * @param func_name Out parameter, the function name |
| 1051 | * @returns 0 on success, -1 on failure |
| 1052 | */ |
| 1053 | static |
| 1054 | int bin_info_lookup_dwarf_function_name(struct bin_info *bin, uint64_t addr, |
| 1055 | char **func_name) |
| 1056 | { |
| 1057 | int ret = 0; |
| 1058 | char *_func_name = NULL; |
| 1059 | struct bt_dwarf_cu *cu = NULL; |
| 1060 | |
| 1061 | if (!bin || !func_name) { |
| 1062 | goto error; |
| 1063 | } |
| 1064 | |
| 1065 | cu = bt_dwarf_cu_create(bin->dwarf_info); |
| 1066 | if (!cu) { |
| 1067 | goto error; |
| 1068 | } |
| 1069 | |
| 1070 | while (bt_dwarf_cu_next(cu) == 0) { |
| 1071 | ret = bin_info_lookup_cu_function_name(cu, addr, &_func_name); |
| 1072 | if (ret) { |
| 1073 | goto error; |
| 1074 | } |
| 1075 | |
| 1076 | if (_func_name) { |
| 1077 | break; |
| 1078 | } |
| 1079 | } |
| 1080 | |
| 1081 | if (_func_name) { |
| 1082 | *func_name = _func_name; |
| 1083 | } else { |
| 1084 | goto error; |
| 1085 | } |
| 1086 | |
| 1087 | bt_dwarf_cu_destroy(cu); |
| 1088 | return 0; |
| 1089 | |
| 1090 | error: |
| 1091 | bt_dwarf_cu_destroy(cu); |
| 1092 | return -1; |
| 1093 | } |
| 1094 | |
| 1095 | BT_HIDDEN |
| 1096 | int bin_info_lookup_function_name(struct bin_info *bin, |
| 1097 | uint64_t addr, char **func_name) |
| 1098 | { |
| 1099 | int ret = 0; |
| 1100 | char *_func_name = NULL; |
| 1101 | |
| 1102 | if (!bin || !func_name) { |
| 1103 | goto error; |
| 1104 | } |
| 1105 | |
| 1106 | /* |
| 1107 | * If the bin_info has a build id but it does not match the build id |
| 1108 | * that was found on the file system, return an error. |
| 1109 | */ |
| 1110 | if (bin->build_id && !bin->file_build_id_matches) { |
| 1111 | goto error; |
| 1112 | } |
| 1113 | |
| 1114 | /* Set DWARF info if it hasn't been accessed yet. */ |
| 1115 | if (!bin->dwarf_info && !bin->is_elf_only) { |
| 1116 | ret = bin_info_set_dwarf_info(bin); |
| 1117 | if (ret) { |
| 1118 | BT_LOGD_STR("Failed to set bin dwarf info, falling " |
| 1119 | "back to ELF lookup."); |
| 1120 | /* Failed to set DWARF info, fallback to ELF. */ |
| 1121 | bin->is_elf_only = true; |
| 1122 | } |
| 1123 | } |
| 1124 | |
| 1125 | if (!bin_info_has_address(bin, addr)) { |
| 1126 | goto error; |
| 1127 | } |
| 1128 | |
| 1129 | /* |
| 1130 | * Addresses in ELF and DWARF are relative to base address for |
| 1131 | * PIC, so make the address argument relative too if needed. |
| 1132 | */ |
| 1133 | if (bin->is_pic) { |
| 1134 | addr -= bin->low_addr; |
| 1135 | } |
| 1136 | |
| 1137 | if (bin->is_elf_only) { |
| 1138 | ret = bin_info_lookup_elf_function_name(bin, addr, |
| 1139 | &_func_name); |
| 1140 | if (ret) { |
| 1141 | BT_LOGD("Failed to lookup function name (ELF): " |
| 1142 | "ret=%d", ret); |
| 1143 | } |
| 1144 | } else { |
| 1145 | ret = bin_info_lookup_dwarf_function_name(bin, addr, |
| 1146 | &_func_name); |
| 1147 | if (ret) { |
| 1148 | BT_LOGD("Failed to lookup function name (DWARF): " |
| 1149 | "ret=%d", ret); |
| 1150 | } |
| 1151 | } |
| 1152 | |
| 1153 | *func_name = _func_name; |
| 1154 | return 0; |
| 1155 | |
| 1156 | error: |
| 1157 | return -1; |
| 1158 | } |
| 1159 | |
| 1160 | BT_HIDDEN |
| 1161 | int bin_info_get_bin_loc(struct bin_info *bin, uint64_t addr, char **bin_loc) |
| 1162 | { |
| 1163 | gchar *_bin_loc = NULL; |
| 1164 | |
| 1165 | if (!bin || !bin_loc) { |
| 1166 | goto error; |
| 1167 | } |
| 1168 | |
| 1169 | /* |
| 1170 | * If the bin_info has a build id but it does not match the build id |
| 1171 | * that was found on the file system, return an error. |
| 1172 | */ |
| 1173 | if (bin->build_id && !bin->file_build_id_matches) { |
| 1174 | goto error; |
| 1175 | } |
| 1176 | |
| 1177 | if (bin->is_pic) { |
| 1178 | addr -= bin->low_addr; |
| 1179 | _bin_loc = g_strdup_printf("+%#0" PRIx64, addr); |
| 1180 | } else { |
| 1181 | _bin_loc = g_strdup_printf("@%#0" PRIx64, addr); |
| 1182 | } |
| 1183 | |
| 1184 | if (!_bin_loc) { |
| 1185 | goto error; |
| 1186 | } |
| 1187 | |
| 1188 | *bin_loc = _bin_loc; |
| 1189 | return 0; |
| 1190 | |
| 1191 | error: |
| 1192 | return -1; |
| 1193 | } |
| 1194 | |
| 1195 | /** |
| 1196 | * Predicate used to determine whether the children of a given DIE |
| 1197 | * contain a specific address. |
| 1198 | * |
| 1199 | * More specifically, the parameter `die` is expected to be a |
| 1200 | * subprogram (function) DIE, and this predicate tells whether any |
| 1201 | * subroutines are inlined within this function and would contain |
| 1202 | * `addr`. |
| 1203 | * |
| 1204 | * On success, the out parameter `contains` is set with the boolean |
| 1205 | * value indicating whether the DIE's range covers `addr`. On failure, |
| 1206 | * it remains unchanged. |
| 1207 | * |
| 1208 | * Do note that this function advances the position of `die`. If the |
| 1209 | * address is found within one of its children, `die` will be pointing |
| 1210 | * to that child upon returning from the function, allowing to extract |
| 1211 | * the information deemed necessary. |
| 1212 | * |
| 1213 | * @param die The parent DIE in whose children the address will be |
| 1214 | * looked for |
| 1215 | * @param addr The address for which to look for in the DIEs |
| 1216 | * @param contains Out parameter, true if addr is contained, |
| 1217 | * false if not |
| 1218 | * @returns Returns 0 on success, -1 on failure |
| 1219 | */ |
| 1220 | static |
| 1221 | int bin_info_child_die_has_address(struct bt_dwarf_die *die, uint64_t addr, bool *contains) |
| 1222 | { |
| 1223 | int ret = 0; |
| 1224 | bool _contains = false; |
| 1225 | |
| 1226 | if (!die) { |
| 1227 | goto error; |
| 1228 | } |
| 1229 | |
| 1230 | ret = bt_dwarf_die_child(die); |
| 1231 | if (ret) { |
| 1232 | goto error; |
| 1233 | } |
| 1234 | |
| 1235 | do { |
| 1236 | ret = bt_dwarf_die_contains_addr(die, addr, &_contains); |
| 1237 | if (ret) { |
| 1238 | goto error; |
| 1239 | } |
| 1240 | |
| 1241 | if (_contains) { |
| 1242 | /* |
| 1243 | * The address is within the range of the current DIE |
| 1244 | * or its children. |
| 1245 | */ |
| 1246 | int tag; |
| 1247 | |
| 1248 | ret = bt_dwarf_die_get_tag(die, &tag); |
| 1249 | if (ret) { |
| 1250 | goto error; |
| 1251 | } |
| 1252 | |
| 1253 | if (tag == DW_TAG_inlined_subroutine) { |
| 1254 | /* Found the tracepoint. */ |
| 1255 | goto end; |
| 1256 | } |
| 1257 | |
| 1258 | if (bt_dwarf_die_has_children(die)) { |
| 1259 | /* |
| 1260 | * Look for the address in the children DIEs. |
| 1261 | */ |
| 1262 | ret = bt_dwarf_die_child(die); |
| 1263 | if (ret) { |
| 1264 | goto error; |
| 1265 | } |
| 1266 | } |
| 1267 | } |
| 1268 | } while (bt_dwarf_die_next(die) == 0); |
| 1269 | |
| 1270 | end: |
| 1271 | *contains = _contains; |
| 1272 | return 0; |
| 1273 | |
| 1274 | error: |
| 1275 | return -1; |
| 1276 | } |
| 1277 | |
| 1278 | /** |
| 1279 | * Lookup the source location for a given address within a CU, making |
| 1280 | * the assumption that it is contained within an inline routine in a |
| 1281 | * function. |
| 1282 | * |
| 1283 | * @param cu bt_dwarf_cu instance in which to look for the address |
| 1284 | * @param addr The address for which to look for |
| 1285 | * @param src_loc Out parameter, the source location (filename and |
| 1286 | * line number) for the address |
| 1287 | * @returns 0 on success, -1 on failure |
| 1288 | */ |
| 1289 | static |
| 1290 | int bin_info_lookup_cu_src_loc_inl(struct bt_dwarf_cu *cu, uint64_t addr, |
| 1291 | struct source_location **src_loc) |
| 1292 | { |
| 1293 | int ret = 0; |
| 1294 | bool found = false; |
| 1295 | struct bt_dwarf_die *die = NULL; |
| 1296 | struct source_location *_src_loc = NULL; |
| 1297 | |
| 1298 | if (!cu || !src_loc) { |
| 1299 | goto error; |
| 1300 | } |
| 1301 | |
| 1302 | die = bt_dwarf_die_create(cu); |
| 1303 | if (!die) { |
| 1304 | goto error; |
| 1305 | } |
| 1306 | |
| 1307 | while (bt_dwarf_die_next(die) == 0) { |
| 1308 | int tag; |
| 1309 | |
| 1310 | ret = bt_dwarf_die_get_tag(die, &tag); |
| 1311 | if (ret) { |
| 1312 | goto error; |
| 1313 | } |
| 1314 | |
| 1315 | if (tag == DW_TAG_subprogram) { |
| 1316 | bool contains = false; |
| 1317 | |
| 1318 | ret = bt_dwarf_die_contains_addr(die, addr, &contains); |
| 1319 | if (ret) { |
| 1320 | goto error; |
| 1321 | } |
| 1322 | |
| 1323 | if (contains) { |
| 1324 | /* |
| 1325 | * Try to find an inlined subroutine |
| 1326 | * child of this DIE containing addr. |
| 1327 | */ |
| 1328 | ret = bin_info_child_die_has_address(die, addr, |
| 1329 | &found); |
| 1330 | if(ret) { |
| 1331 | goto error; |
| 1332 | } |
| 1333 | |
| 1334 | goto end; |
| 1335 | } |
| 1336 | } |
| 1337 | } |
| 1338 | |
| 1339 | end: |
| 1340 | if (found) { |
| 1341 | char *filename = NULL; |
| 1342 | uint64_t line_no; |
| 1343 | |
| 1344 | _src_loc = g_new0(struct source_location, 1); |
| 1345 | if (!_src_loc) { |
| 1346 | goto error; |
| 1347 | } |
| 1348 | |
| 1349 | ret = bt_dwarf_die_get_call_file(die, &filename); |
| 1350 | if (ret) { |
| 1351 | goto error; |
| 1352 | } |
| 1353 | ret = bt_dwarf_die_get_call_line(die, &line_no); |
| 1354 | if (ret) { |
| 1355 | free(filename); |
| 1356 | goto error; |
| 1357 | } |
| 1358 | |
| 1359 | _src_loc->filename = filename; |
| 1360 | _src_loc->line_no = line_no; |
| 1361 | *src_loc = _src_loc; |
| 1362 | } |
| 1363 | |
| 1364 | bt_dwarf_die_destroy(die); |
| 1365 | return 0; |
| 1366 | |
| 1367 | error: |
| 1368 | source_location_destroy(_src_loc); |
| 1369 | bt_dwarf_die_destroy(die); |
| 1370 | return -1; |
| 1371 | } |
| 1372 | |
| 1373 | /** |
| 1374 | * Lookup the source location for a given address within a CU, |
| 1375 | * assuming that it is contained within an inlined function. |
| 1376 | * |
| 1377 | * A source location can be found regardless of inlining status for |
| 1378 | * this method, but in the case of an inlined function, the returned |
| 1379 | * source location will point not to the callsite but rather to the |
| 1380 | * definition site of the inline function. |
| 1381 | * |
| 1382 | * @param cu bt_dwarf_cu instance in which to look for the address |
| 1383 | * @param addr The address for which to look for |
| 1384 | * @param src_loc Out parameter, the source location (filename and |
| 1385 | * line number) for the address. Set only if the address |
| 1386 | * is found and resolved successfully |
| 1387 | * |
| 1388 | * @returns 0 on success, -1 on failure |
| 1389 | */ |
| 1390 | static |
| 1391 | int bin_info_lookup_cu_src_loc_no_inl(struct bt_dwarf_cu *cu, uint64_t addr, |
| 1392 | struct source_location **src_loc) |
| 1393 | { |
| 1394 | struct source_location *_src_loc = NULL; |
| 1395 | struct bt_dwarf_die *die = NULL; |
| 1396 | const char *filename = NULL; |
| 1397 | Dwarf_Line *line = NULL; |
| 1398 | Dwarf_Addr line_addr; |
| 1399 | int ret, line_no; |
| 1400 | |
| 1401 | if (!cu || !src_loc) { |
| 1402 | goto error; |
| 1403 | } |
| 1404 | |
| 1405 | die = bt_dwarf_die_create(cu); |
| 1406 | if (!die) { |
| 1407 | goto error; |
| 1408 | } |
| 1409 | |
| 1410 | line = dwarf_getsrc_die(die->dwarf_die, addr); |
| 1411 | if (!line) { |
| 1412 | /* This is not an error. The caller needs to keep looking. */ |
| 1413 | goto end; |
| 1414 | } |
| 1415 | |
| 1416 | ret = dwarf_lineaddr(line, &line_addr); |
| 1417 | if (ret) { |
| 1418 | goto error; |
| 1419 | } |
| 1420 | |
| 1421 | filename = dwarf_linesrc(line, NULL, NULL); |
| 1422 | if (!filename) { |
| 1423 | goto error; |
| 1424 | } |
| 1425 | |
| 1426 | if (addr == line_addr) { |
| 1427 | _src_loc = g_new0(struct source_location, 1); |
| 1428 | if (!_src_loc) { |
| 1429 | goto error; |
| 1430 | } |
| 1431 | |
| 1432 | ret = dwarf_lineno(line, &line_no); |
| 1433 | if (ret) { |
| 1434 | goto error; |
| 1435 | } |
| 1436 | |
| 1437 | _src_loc->line_no = line_no; |
| 1438 | _src_loc->filename = g_strdup(filename); |
| 1439 | } |
| 1440 | |
| 1441 | bt_dwarf_die_destroy(die); |
| 1442 | |
| 1443 | if (_src_loc) { |
| 1444 | *src_loc = _src_loc; |
| 1445 | } |
| 1446 | |
| 1447 | end: |
| 1448 | return 0; |
| 1449 | |
| 1450 | error: |
| 1451 | source_location_destroy(_src_loc); |
| 1452 | bt_dwarf_die_destroy(die); |
| 1453 | return -1; |
| 1454 | } |
| 1455 | |
| 1456 | /** |
| 1457 | * Get the source location (file name and line number) for a given |
| 1458 | * address within a compile unit (CU). |
| 1459 | * |
| 1460 | * On success, the out parameter `src_loc` is set if found. On |
| 1461 | * failure, it remains unchanged. |
| 1462 | * |
| 1463 | * @param cu bt_dwarf_cu instance for the compile unit which |
| 1464 | * may contain the address |
| 1465 | * @param addr Virtual memory address for which to find the |
| 1466 | * source location |
| 1467 | * @param src_loc Out parameter, the source location |
| 1468 | * @returns 0 on success, -1 on failure |
| 1469 | */ |
| 1470 | static |
| 1471 | int bin_info_lookup_cu_src_loc(struct bt_dwarf_cu *cu, uint64_t addr, |
| 1472 | struct source_location **src_loc) |
| 1473 | { |
| 1474 | int ret = 0; |
| 1475 | struct source_location *_src_loc = NULL; |
| 1476 | |
| 1477 | if (!cu || !src_loc) { |
| 1478 | goto error; |
| 1479 | } |
| 1480 | |
| 1481 | ret = bin_info_lookup_cu_src_loc_inl(cu, addr, &_src_loc); |
| 1482 | if (ret) { |
| 1483 | goto error; |
| 1484 | } |
| 1485 | |
| 1486 | if (_src_loc) { |
| 1487 | goto end; |
| 1488 | } |
| 1489 | |
| 1490 | ret = bin_info_lookup_cu_src_loc_no_inl(cu, addr, &_src_loc); |
| 1491 | if (ret) { |
| 1492 | goto error; |
| 1493 | } |
| 1494 | |
| 1495 | if (_src_loc) { |
| 1496 | goto end; |
| 1497 | } |
| 1498 | |
| 1499 | end: |
| 1500 | if (_src_loc) { |
| 1501 | *src_loc = _src_loc; |
| 1502 | } |
| 1503 | |
| 1504 | return 0; |
| 1505 | |
| 1506 | error: |
| 1507 | source_location_destroy(_src_loc); |
| 1508 | return -1; |
| 1509 | } |
| 1510 | |
| 1511 | BT_HIDDEN |
| 1512 | int bin_info_lookup_source_location(struct bin_info *bin, uint64_t addr, |
| 1513 | struct source_location **src_loc) |
| 1514 | { |
| 1515 | struct bt_dwarf_cu *cu = NULL; |
| 1516 | struct source_location *_src_loc = NULL; |
| 1517 | |
| 1518 | if (!bin || !src_loc) { |
| 1519 | goto error; |
| 1520 | } |
| 1521 | |
| 1522 | /* |
| 1523 | * If the bin_info has a build id but it does not match the build id |
| 1524 | * that was found on the file system, return an error. |
| 1525 | */ |
| 1526 | if (bin->build_id && !bin->file_build_id_matches) { |
| 1527 | goto error; |
| 1528 | } |
| 1529 | |
| 1530 | /* Set DWARF info if it hasn't been accessed yet. */ |
| 1531 | if (!bin->dwarf_info && !bin->is_elf_only) { |
| 1532 | if (bin_info_set_dwarf_info(bin)) { |
| 1533 | /* Failed to set DWARF info. */ |
| 1534 | bin->is_elf_only = true; |
| 1535 | } |
| 1536 | } |
| 1537 | |
| 1538 | if (bin->is_elf_only) { |
| 1539 | /* We cannot lookup source location without DWARF info. */ |
| 1540 | goto error; |
| 1541 | } |
| 1542 | |
| 1543 | if (!bin_info_has_address(bin, addr)) { |
| 1544 | goto error; |
| 1545 | } |
| 1546 | |
| 1547 | /* |
| 1548 | * Addresses in ELF and DWARF are relative to base address for |
| 1549 | * PIC, so make the address argument relative too if needed. |
| 1550 | */ |
| 1551 | if (bin->is_pic) { |
| 1552 | addr -= bin->low_addr; |
| 1553 | } |
| 1554 | |
| 1555 | cu = bt_dwarf_cu_create(bin->dwarf_info); |
| 1556 | if (!cu) { |
| 1557 | goto error; |
| 1558 | } |
| 1559 | |
| 1560 | while (bt_dwarf_cu_next(cu) == 0) { |
| 1561 | int ret; |
| 1562 | |
| 1563 | ret = bin_info_lookup_cu_src_loc(cu, addr, &_src_loc); |
| 1564 | if (ret) { |
| 1565 | goto error; |
| 1566 | } |
| 1567 | |
| 1568 | if (_src_loc) { |
| 1569 | break; |
| 1570 | } |
| 1571 | } |
| 1572 | |
| 1573 | bt_dwarf_cu_destroy(cu); |
| 1574 | if (_src_loc) { |
| 1575 | *src_loc = _src_loc; |
| 1576 | } |
| 1577 | |
| 1578 | return 0; |
| 1579 | |
| 1580 | error: |
| 1581 | source_location_destroy(_src_loc); |
| 1582 | bt_dwarf_cu_destroy(cu); |
| 1583 | return -1; |
| 1584 | } |