Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame^] | 1 | /* Compare relevant content of two ELF files. |
| 2 | Copyright (C) 2005 Red Hat, Inc. |
| 3 | Written by Ulrich Drepper <drepper@redhat.com>, 2005. |
| 4 | |
| 5 | This program is Open Source software; you can redistribute it and/or |
| 6 | modify it under the terms of the Open Software License version 1.0 as |
| 7 | published by the Open Source Initiative. |
| 8 | |
| 9 | You should have received a copy of the Open Software License along |
| 10 | with this program; if not, you may obtain a copy of the Open Software |
| 11 | License version 1.0 from http://www.opensource.org/licenses/osl.php or |
| 12 | by writing the Open Source Initiative c/o Lawrence Rosen, Esq., |
| 13 | 3001 King Ranch Road, Ukiah, CA 95482. */ |
| 14 | |
| 15 | #ifdef HAVE_CONFIG_H |
| 16 | # include <config.h> |
| 17 | #endif |
| 18 | |
| 19 | #include <argp.h> |
| 20 | #include <assert.h> |
| 21 | #include <errno.h> |
| 22 | #include <error.h> |
| 23 | #include <fcntl.h> |
| 24 | #include <libintl.h> |
| 25 | #include <stdbool.h> |
| 26 | #include <stdio.h> |
| 27 | #include <stdlib.h> |
| 28 | #include <string.h> |
| 29 | #include <unistd.h> |
| 30 | |
| 31 | #include "../libelf/elf-knowledge.h" |
| 32 | #include "../libebl/libeblP.h" |
| 33 | |
| 34 | |
| 35 | /* Prototypes of local functions. */ |
| 36 | static Elf *open_file (const char *fname, int *fdp, Ebl **eblp); |
| 37 | static bool search_for_copy_reloc (Ebl *ebl, size_t scnndx, int symndx); |
| 38 | static int regioncompare (const void *p1, const void *p2); |
| 39 | |
| 40 | |
| 41 | /* Name and version of program. */ |
| 42 | static void print_version (FILE *stream, struct argp_state *state); |
| 43 | void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version; |
| 44 | |
| 45 | /* Bug report address. */ |
| 46 | const char *argp_program_bug_address = PACKAGE_BUGREPORT; |
| 47 | |
| 48 | /* Values for the parameters which have no short form. */ |
| 49 | #define OPT_GAPS 0x100 |
| 50 | |
| 51 | /* Definitions of arguments for argp functions. */ |
| 52 | static const struct argp_option options[] = |
| 53 | { |
| 54 | { NULL, 0, NULL, 0, N_("Control options:"), 0 }, |
| 55 | { "gaps", OPT_GAPS, "ACTION", 0, N_("Control treatment of gaps in loadable segments [ignore|match] (default: ignore)"), 0 }, |
| 56 | { "quiet", 'q', NULL, 0, N_("Output nothing; yield exit status only"), 0 }, |
| 57 | |
| 58 | { NULL, 0, NULL, 0, N_("Miscellaneous:"), 0 }, |
| 59 | { NULL, 0, NULL, 0, NULL, 0 } |
| 60 | }; |
| 61 | |
| 62 | /* Short description of program. */ |
| 63 | static const char doc[] = N_("\ |
| 64 | Compare relevant parts of two ELF files for equality."); |
| 65 | |
| 66 | /* Strings for arguments in help texts. */ |
| 67 | static const char args_doc[] = N_("FILE1 FILE2"); |
| 68 | |
| 69 | /* Prototype for option handler. */ |
| 70 | static error_t parse_opt (int key, char *arg, struct argp_state *state); |
| 71 | |
| 72 | /* Data structure to communicate with argp functions. */ |
| 73 | static struct argp argp = |
| 74 | { |
| 75 | options, parse_opt, args_doc, doc, NULL, NULL, NULL |
| 76 | }; |
| 77 | |
| 78 | |
| 79 | /* How to treat gaps in loadable segments. */ |
| 80 | static enum |
| 81 | { |
| 82 | gaps_ignore = 0, |
| 83 | gaps_match |
| 84 | } |
| 85 | gaps; |
| 86 | |
| 87 | /* Structure to hold information about used regions. */ |
| 88 | struct region |
| 89 | { |
| 90 | GElf_Addr from; |
| 91 | GElf_Addr to; |
| 92 | struct region *next; |
| 93 | }; |
| 94 | |
| 95 | /* Nonzero if only exit status is wanted. */ |
| 96 | static bool quiet; |
| 97 | |
| 98 | |
| 99 | int |
| 100 | main (int argc, char *argv[]) |
| 101 | { |
| 102 | /* Set locale. */ |
| 103 | (void) setlocale (LC_ALL, ""); |
| 104 | |
| 105 | /* Make sure the message catalog can be found. */ |
| 106 | (void) bindtextdomain (PACKAGE, LOCALEDIR); |
| 107 | |
| 108 | /* Initialize the message catalog. */ |
| 109 | (void) textdomain (PACKAGE); |
| 110 | |
| 111 | /* Parse and process arguments. */ |
| 112 | int remaining; |
| 113 | (void) argp_parse (&argp, argc, argv, 0, &remaining, NULL); |
| 114 | |
| 115 | /* We expect exactly two non-option parameters. */ |
| 116 | if (remaining + 2 != argc) |
| 117 | { |
| 118 | fputs (gettext ("Invalid number of parameters.\n"), stderr); |
| 119 | argp_help (&argp, stderr, ARGP_HELP_SEE, program_invocation_short_name); |
| 120 | exit (1); |
| 121 | } |
| 122 | |
| 123 | /* Comparing the files is done in two phases: |
| 124 | 1. compare all sections. Sections which are irrelevant (i.e., if |
| 125 | strip would remove them) are ignored. Some section types are |
| 126 | handled special. |
| 127 | 2. all parts of the loadable segments which are not parts of any |
| 128 | section is compared according to the rules of the --gaps option. |
| 129 | */ |
| 130 | int result = 0; |
| 131 | elf_version (EV_CURRENT); |
| 132 | |
| 133 | const char *const fname1 = argv[remaining]; |
| 134 | int fd1; |
| 135 | Ebl *ebl1; |
| 136 | Elf *elf1 = open_file (fname1, &fd1, &ebl1); |
| 137 | |
| 138 | const char *const fname2 = argv[remaining + 1]; |
| 139 | int fd2; |
| 140 | Ebl *ebl2; |
| 141 | Elf *elf2 = open_file (fname2, &fd2, &ebl2); |
| 142 | |
| 143 | GElf_Ehdr ehdr1_mem; |
| 144 | GElf_Ehdr *ehdr1 = gelf_getehdr (elf1, &ehdr1_mem); |
| 145 | if (ehdr1 == NULL) |
| 146 | error (EXIT_FAILURE, 0, gettext ("cannot get ELF header of \"%s\": %s"), |
| 147 | fname1, elf_errmsg (-1)); |
| 148 | GElf_Ehdr ehdr2_mem; |
| 149 | GElf_Ehdr *ehdr2 = gelf_getehdr (elf2, &ehdr2_mem); |
| 150 | if (ehdr2 == NULL) |
| 151 | error (EXIT_FAILURE, 0, gettext ("cannot get ELF header of \"%s\": %s"), |
| 152 | fname2, elf_errmsg (-1)); |
| 153 | |
| 154 | /* Compare the ELF headers. */ |
| 155 | if (memcmp (ehdr1->e_ident, ehdr2->e_ident, EI_NIDENT) != 0 |
| 156 | || ehdr1->e_type != ehdr2->e_type |
| 157 | || ehdr1->e_machine != ehdr2->e_machine |
| 158 | || ehdr1->e_version != ehdr2->e_version |
| 159 | || ehdr1->e_entry != ehdr2->e_entry |
| 160 | || ehdr1->e_phoff != ehdr2->e_phoff |
| 161 | || ehdr1->e_flags != ehdr2->e_flags |
| 162 | || ehdr1->e_ehsize != ehdr2->e_ehsize |
| 163 | || ehdr1->e_phentsize != ehdr2->e_phentsize |
| 164 | || ehdr1->e_phnum != ehdr2->e_phnum |
| 165 | || ehdr1->e_shentsize != ehdr2->e_shentsize |
| 166 | || ehdr1->e_shnum != ehdr2->e_shnum |
| 167 | || ehdr1->e_shstrndx != ehdr2->e_shstrndx) |
| 168 | { |
| 169 | if (! quiet) |
| 170 | error (0, 0, gettext ("%s %s diff: ELF header"), fname1, fname2); |
| 171 | result = 1; |
| 172 | goto out; |
| 173 | } |
| 174 | |
| 175 | /* Iterate over all sections. We expect the sections in the two |
| 176 | files to match exactly. */ |
| 177 | Elf_Scn *scn1 = NULL; |
| 178 | Elf_Scn *scn2 = NULL; |
| 179 | struct region *regions = NULL; |
| 180 | size_t nregions = 0; |
| 181 | while (1) |
| 182 | { |
| 183 | GElf_Shdr shdr1_mem; |
| 184 | GElf_Shdr *shdr1; |
| 185 | const char *sname1 = NULL; |
| 186 | do |
| 187 | { |
| 188 | scn1 = elf_nextscn (elf1, scn1); |
| 189 | shdr1 = gelf_getshdr (scn1, &shdr1_mem); |
| 190 | if (shdr1 != NULL) |
| 191 | sname1 = elf_strptr (elf1, ehdr1->e_shstrndx, shdr1->sh_name); |
| 192 | } |
| 193 | while (scn1 != NULL |
| 194 | && ebl_section_strip_p (ebl1, ehdr1, shdr1, sname1, true, false)); |
| 195 | |
| 196 | GElf_Shdr shdr2_mem; |
| 197 | GElf_Shdr *shdr2; |
| 198 | const char *sname2 = NULL; |
| 199 | do |
| 200 | { |
| 201 | scn2 = elf_nextscn (elf2, scn2); |
| 202 | shdr2 = gelf_getshdr (scn2, &shdr2_mem); |
| 203 | if (shdr2 != NULL) |
| 204 | sname2 = elf_strptr (elf2, ehdr2->e_shstrndx, shdr2->sh_name); |
| 205 | } |
| 206 | while (scn2 != NULL |
| 207 | && ebl_section_strip_p (ebl2, ehdr2, shdr2, sname2, true, false)); |
| 208 | |
| 209 | if (scn1 == NULL || scn2 == NULL) |
| 210 | break; |
| 211 | |
| 212 | if (gaps != gaps_ignore && (shdr1->sh_flags & SHF_ALLOC) != 0) |
| 213 | { |
| 214 | struct region *newp = (struct region *) alloca (sizeof (*newp)); |
| 215 | newp->from = shdr1->sh_offset; |
| 216 | newp->to = shdr1->sh_offset + shdr1->sh_size; |
| 217 | newp->next = regions; |
| 218 | regions = newp; |
| 219 | |
| 220 | ++nregions; |
| 221 | } |
| 222 | |
| 223 | /* Compare the headers. We allow the name to be at a different |
| 224 | location. */ |
| 225 | if (strcmp (sname1, sname2) != 0) |
| 226 | { |
| 227 | header_mismatch: |
| 228 | error (0, 0, gettext ("%s %s differ: section header"), |
| 229 | fname1, fname2); |
| 230 | result = 1; |
| 231 | goto out; |
| 232 | } |
| 233 | |
| 234 | /* We ignore certain sections. */ |
| 235 | if (strcmp (sname1, ".gnu_debuglink") == 0 |
| 236 | || strcmp (sname1, ".gnu.prelink_undo") == 0) |
| 237 | continue; |
| 238 | |
| 239 | if (shdr1->sh_type != shdr2->sh_type |
| 240 | // XXX Any flags which should be ignored? |
| 241 | || shdr1->sh_flags != shdr2->sh_flags |
| 242 | || shdr1->sh_addr != shdr2->sh_addr |
| 243 | || shdr1->sh_offset != shdr2->sh_offset |
| 244 | || shdr1->sh_size != shdr2->sh_size |
| 245 | || shdr1->sh_link != shdr2->sh_link |
| 246 | || shdr1->sh_info != shdr2->sh_info |
| 247 | || shdr1->sh_addralign != shdr2->sh_addralign |
| 248 | || shdr1->sh_entsize != shdr2->sh_entsize) |
| 249 | goto header_mismatch; |
| 250 | |
| 251 | Elf_Data *data1 = elf_getdata (scn1, NULL); |
| 252 | if (data1 == NULL) |
| 253 | error (EXIT_FAILURE, 0, |
| 254 | gettext ("cannot get content of section %zu in \"%s\": %s"), |
| 255 | elf_ndxscn (scn1), fname1, elf_errmsg (-1)); |
| 256 | |
| 257 | Elf_Data *data2 = elf_getdata (scn2, NULL); |
| 258 | if (data2 == NULL) |
| 259 | error (EXIT_FAILURE, 0, |
| 260 | gettext ("cannot get content of section %zu in \"%s\": %s"), |
| 261 | elf_ndxscn (scn2), fname2, elf_errmsg (-1)); |
| 262 | |
| 263 | switch (shdr1->sh_type) |
| 264 | { |
| 265 | case SHT_DYNSYM: |
| 266 | case SHT_SYMTAB: |
| 267 | /* Iterate over the symbol table. We ignore the st_size |
| 268 | value of undefined symbols. */ |
| 269 | for (int ndx = 0; ndx < (int) (shdr1->sh_size / shdr1->sh_entsize); |
| 270 | ++ndx) |
| 271 | { |
| 272 | GElf_Sym sym1_mem; |
| 273 | GElf_Sym *sym1 = gelf_getsym (data1, ndx, &sym1_mem); |
| 274 | if (sym1 == NULL) |
| 275 | error (EXIT_FAILURE, 0, |
| 276 | gettext ("cannot get symbol in \"%s\": %s"), |
| 277 | fname1, elf_errmsg (-1)); |
| 278 | GElf_Sym sym2_mem; |
| 279 | GElf_Sym *sym2 = gelf_getsym (data2, ndx, &sym2_mem); |
| 280 | if (sym2 == NULL) |
| 281 | error (EXIT_FAILURE, 0, |
| 282 | gettext ("cannot get symbol in \"%s\": %s"), |
| 283 | fname2, elf_errmsg (-1)); |
| 284 | |
| 285 | const char *name1 = elf_strptr (elf1, shdr1->sh_link, |
| 286 | sym1->st_name); |
| 287 | const char *name2 = elf_strptr (elf2, shdr2->sh_link, |
| 288 | sym2->st_name); |
| 289 | if (strcmp (name1, name2) != 0 |
| 290 | || sym1->st_value != sym2->st_value |
| 291 | || (sym1->st_size != sym2->st_size |
| 292 | && sym1->st_shndx != SHN_UNDEF) |
| 293 | || sym1->st_info != sym2->st_info |
| 294 | || sym1->st_other != sym2->st_other |
| 295 | || sym1->st_shndx != sym1->st_shndx) |
| 296 | { |
| 297 | // XXX Do we want to allow reordered symbol tables? |
| 298 | if (! quiet) |
| 299 | error (0, 0, gettext ("%s %s differ: symbol table"), |
| 300 | fname1, fname2); |
| 301 | result = 1; |
| 302 | goto out; |
| 303 | } |
| 304 | |
| 305 | if (sym1->st_shndx == SHN_UNDEF |
| 306 | && sym1->st_size != sym2->st_size) |
| 307 | { |
| 308 | /* The size of the symbol in the object defining it |
| 309 | might have changed. That is OK unless the symbol |
| 310 | is used in a copy relocation. Look over the |
| 311 | sections in both files and determine which |
| 312 | relocation section uses this symbol table |
| 313 | section. Then look through the relocations to |
| 314 | see whether any copy relocation references this |
| 315 | symbol. */ |
| 316 | if (search_for_copy_reloc (ebl1, elf_ndxscn (scn1), ndx) |
| 317 | || search_for_copy_reloc (ebl2, elf_ndxscn (scn2), ndx)) |
| 318 | { |
| 319 | if (! quiet) |
| 320 | error (0, 0, gettext ("%s %s differ: symbol table"), |
| 321 | fname1, fname2); |
| 322 | result = 1; |
| 323 | goto out; |
| 324 | } |
| 325 | } |
| 326 | } |
| 327 | break; |
| 328 | |
| 329 | default: |
| 330 | /* Compare the section content byte for byte. */ |
| 331 | assert (shdr1->sh_type == SHT_NOBITS |
| 332 | || (data1->d_buf != NULL || data1->d_size == 0)); |
| 333 | assert (shdr2->sh_type == SHT_NOBITS |
| 334 | || (data2->d_buf != NULL || data1->d_size == 0)); |
| 335 | |
| 336 | if (data1->d_size != data2->d_size |
| 337 | || (shdr1->sh_type != SHT_NOBITS |
| 338 | && memcmp (data1->d_buf, data2->d_buf, data1->d_size) != 0)) |
| 339 | { |
| 340 | if (! quiet) |
| 341 | error (0, 0, gettext ("%s %s differ: section content"), |
| 342 | fname1, fname2); |
| 343 | result = 1; |
| 344 | goto out; |
| 345 | } |
| 346 | break; |
| 347 | } |
| 348 | } |
| 349 | |
| 350 | if (scn1 != scn2) |
| 351 | { |
| 352 | if (! quiet) |
| 353 | error (0, 0, |
| 354 | gettext ("%s %s differ: unequal amount of important sections"), |
| 355 | fname1, fname2); |
| 356 | result = 1; |
| 357 | goto out; |
| 358 | } |
| 359 | |
| 360 | /* We we look at gaps, create artificial ones for the parts of the |
| 361 | program which we are not in sections. */ |
| 362 | struct region ehdr_region; |
| 363 | struct region phdr_region; |
| 364 | if (gaps != gaps_ignore) |
| 365 | { |
| 366 | ehdr_region.from = 0; |
| 367 | ehdr_region.to = ehdr1->e_ehsize; |
| 368 | ehdr_region.next = &phdr_region; |
| 369 | |
| 370 | phdr_region.from = ehdr1->e_phoff; |
| 371 | phdr_region.to = ehdr1->e_phoff + ehdr1->e_phnum * ehdr1->e_phentsize; |
| 372 | phdr_region.next = regions; |
| 373 | |
| 374 | regions = &ehdr_region; |
| 375 | nregions += 2; |
| 376 | } |
| 377 | |
| 378 | /* If we need to look at the gaps we need access to the file data. */ |
| 379 | char *raw1 = NULL; |
| 380 | size_t size1 = 0; |
| 381 | char *raw2 = NULL; |
| 382 | size_t size2 = 0; |
| 383 | struct region *regionsarr = alloca (nregions * sizeof (struct region)); |
| 384 | if (gaps != gaps_ignore) |
| 385 | { |
| 386 | raw1 = elf_rawfile (elf1, &size1); |
| 387 | if (raw1 == NULL ) |
| 388 | error (EXIT_FAILURE, 0, gettext ("cannot load data of \"%s\": %s"), |
| 389 | fname1, elf_errmsg (-1)); |
| 390 | |
| 391 | raw2 = elf_rawfile (elf2, &size2); |
| 392 | if (raw2 == NULL ) |
| 393 | error (EXIT_FAILURE, 0, gettext ("cannot load data of \"%s\": %s"), |
| 394 | fname2, elf_errmsg (-1)); |
| 395 | |
| 396 | for (size_t cnt = 0; cnt < nregions; ++cnt) |
| 397 | { |
| 398 | regionsarr[cnt] = *regions; |
| 399 | regions = regions->next; |
| 400 | } |
| 401 | |
| 402 | qsort (regionsarr, nregions, sizeof (regionsarr[0]), regioncompare); |
| 403 | } |
| 404 | |
| 405 | /* Compare the program header tables. */ |
| 406 | for (int ndx = 0; ndx < ehdr1->e_phnum; ++ndx) |
| 407 | { |
| 408 | GElf_Phdr phdr1_mem; |
| 409 | GElf_Phdr *phdr1 = gelf_getphdr (elf1, ndx, &phdr1_mem); |
| 410 | if (ehdr1 == NULL) |
| 411 | error (EXIT_FAILURE, 0, |
| 412 | gettext ("cannot get program header entry %d of \"%s\": %s"), |
| 413 | ndx, fname1, elf_errmsg (-1)); |
| 414 | GElf_Phdr phdr2_mem; |
| 415 | GElf_Phdr *phdr2 = gelf_getphdr (elf2, ndx, &phdr2_mem); |
| 416 | if (ehdr2 == NULL) |
| 417 | error (EXIT_FAILURE, 0, |
| 418 | gettext ("cannot get program header entry %d of \"%s\": %s"), |
| 419 | ndx, fname2, elf_errmsg (-1)); |
| 420 | |
| 421 | if (memcmp (phdr1, phdr2, sizeof (GElf_Phdr)) != 0) |
| 422 | { |
| 423 | if (! quiet) |
| 424 | error (0, 0, gettext ("%s %s differ: program header %d"), |
| 425 | fname1, fname2, ndx); |
| 426 | result = 1; |
| 427 | goto out; |
| 428 | } |
| 429 | |
| 430 | if (gaps != gaps_ignore && phdr1->p_type == PT_LOAD) |
| 431 | { |
| 432 | size_t cnt = 0; |
| 433 | while (cnt < nregions && regionsarr[cnt].to < phdr1->p_offset) |
| 434 | ++cnt; |
| 435 | |
| 436 | GElf_Off last = phdr1->p_offset; |
| 437 | GElf_Off end = phdr1->p_offset + phdr1->p_filesz; |
| 438 | while (cnt < nregions && regionsarr[cnt].from < end) |
| 439 | { |
| 440 | if (last < regionsarr[cnt].from) |
| 441 | { |
| 442 | /* Compare the [LAST,FROM) region. */ |
| 443 | assert (gaps == gaps_match); |
| 444 | if (memcmp (raw1 + last, raw2 + last, |
| 445 | regionsarr[cnt].from - last) != 0) |
| 446 | { |
| 447 | gapmismatch: |
| 448 | if (!quiet) |
| 449 | error (0, 0, gettext ("%s %s differ: gap"), |
| 450 | fname1, fname2); |
| 451 | result = 1; |
| 452 | goto out; |
| 453 | } |
| 454 | |
| 455 | } |
| 456 | last = regionsarr[cnt].to; |
| 457 | ++cnt; |
| 458 | } |
| 459 | |
| 460 | if (cnt == nregions && last < end) |
| 461 | goto gapmismatch; |
| 462 | } |
| 463 | } |
| 464 | |
| 465 | out: |
| 466 | elf_end (elf1); |
| 467 | elf_end (elf2); |
| 468 | close (fd1); |
| 469 | close (fd2); |
| 470 | |
| 471 | return result; |
| 472 | } |
| 473 | |
| 474 | |
| 475 | /* Print the version information. */ |
| 476 | static void |
| 477 | print_version (FILE *stream, struct argp_state *state __attribute__ ((unused))) |
| 478 | { |
| 479 | fprintf (stream, "elfcmp (%s) %s\n", PACKAGE_NAME, VERSION); |
| 480 | fprintf (stream, gettext ("\ |
| 481 | Copyright (C) %s Red Hat, Inc.\n\ |
| 482 | This is free software; see the source for copying conditions. There is NO\n\ |
| 483 | warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\ |
| 484 | "), "2005"); |
| 485 | fprintf (stream, gettext ("Written by %s.\n"), "Ulrich Drepper"); |
| 486 | } |
| 487 | |
| 488 | |
| 489 | /* Handle program arguments. */ |
| 490 | static error_t |
| 491 | parse_opt (int key, char *arg, |
| 492 | struct argp_state *state __attribute__ ((unused))) |
| 493 | { |
| 494 | switch (key) |
| 495 | { |
| 496 | case 'q': |
| 497 | quiet = true; |
| 498 | break; |
| 499 | |
| 500 | case OPT_GAPS: |
| 501 | if (strcasecmp (arg, "ignore") == 0) |
| 502 | gaps = gaps_ignore; |
| 503 | else if (strcasecmp (arg, "match") == 0) |
| 504 | gaps = gaps_match; |
| 505 | else |
| 506 | { |
| 507 | fprintf (stderr, |
| 508 | gettext ("Invalid value \"%s\" for --gaps parameter."), |
| 509 | arg); |
| 510 | argp_help (&argp, stderr, ARGP_HELP_SEE, |
| 511 | program_invocation_short_name); |
| 512 | exit (1); |
| 513 | } |
| 514 | break; |
| 515 | |
| 516 | default: |
| 517 | return ARGP_ERR_UNKNOWN; |
| 518 | } |
| 519 | return 0; |
| 520 | } |
| 521 | |
| 522 | |
| 523 | static Elf * |
| 524 | open_file (const char *fname, int *fdp, Ebl **eblp) |
| 525 | { |
| 526 | int fd = open (fname, O_RDONLY); |
| 527 | if (unlikely (fd == -1)) |
| 528 | error (EXIT_FAILURE, errno, gettext ("cannot open \"%s\""), fname); |
| 529 | Elf *elf = elf_begin (fd, ELF_C_READ_MMAP, NULL); |
| 530 | if (elf == NULL) |
| 531 | error (EXIT_FAILURE, 0, |
| 532 | gettext ("cannot create ELF descriptor for \"%s\": %s"), |
| 533 | fname, elf_errmsg (-1)); |
| 534 | Ebl *ebl = ebl_openbackend (elf); |
| 535 | if (ebl == NULL) |
| 536 | error (EXIT_FAILURE, 0, |
| 537 | gettext ("cannot create EBL descriptor for \"%s\""), fname); |
| 538 | |
| 539 | *fdp = fd; |
| 540 | *eblp = ebl; |
| 541 | return elf; |
| 542 | } |
| 543 | |
| 544 | |
| 545 | static bool |
| 546 | search_for_copy_reloc (Ebl *ebl, size_t scnndx, int symndx) |
| 547 | { |
| 548 | Elf_Scn *scn = NULL; |
| 549 | while ((scn = elf_nextscn (ebl->elf, scn)) != NULL) |
| 550 | { |
| 551 | GElf_Shdr shdr_mem; |
| 552 | GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); |
| 553 | if (shdr == NULL) |
| 554 | error (EXIT_FAILURE, 0, |
| 555 | gettext ("cannot get section header of section %zu: %s"), |
| 556 | elf_ndxscn (scn), elf_errmsg (-1)); |
| 557 | |
| 558 | if ((shdr->sh_type != SHT_REL && shdr->sh_type != SHT_RELA) |
| 559 | || shdr->sh_link != scnndx) |
| 560 | continue; |
| 561 | |
| 562 | Elf_Data *data = elf_getdata (scn, NULL); |
| 563 | if (data == NULL) |
| 564 | error (EXIT_FAILURE, 0, |
| 565 | gettext ("cannot get content of section %zu: %s"), |
| 566 | elf_ndxscn (scn), elf_errmsg (-1)); |
| 567 | |
| 568 | if (shdr->sh_type == SHT_REL) |
| 569 | for (int ndx = 0; ndx < (int) (shdr->sh_size / shdr->sh_entsize); |
| 570 | ++ndx) |
| 571 | { |
| 572 | GElf_Rel rel_mem; |
| 573 | GElf_Rel *rel = gelf_getrel (data, ndx, &rel_mem); |
| 574 | if (rel == NULL) |
| 575 | error (EXIT_FAILURE, 0, gettext ("cannot get relocation: %s"), |
| 576 | elf_errmsg (-1)); |
| 577 | |
| 578 | if ((int) GELF_R_SYM (rel->r_info) == symndx |
| 579 | && ebl_copy_reloc_p (ebl, GELF_R_TYPE (rel->r_info))) |
| 580 | return true; |
| 581 | } |
| 582 | else |
| 583 | for (int ndx = 0; ndx < (int) (shdr->sh_size / shdr->sh_entsize); |
| 584 | ++ndx) |
| 585 | { |
| 586 | GElf_Rela rela_mem; |
| 587 | GElf_Rela *rela = gelf_getrela (data, ndx, &rela_mem); |
| 588 | if (rela == NULL) |
| 589 | error (EXIT_FAILURE, 0, gettext ("cannot get relocation: %s"), |
| 590 | elf_errmsg (-1)); |
| 591 | |
| 592 | if ((int) GELF_R_SYM (rela->r_info) == symndx |
| 593 | && ebl_copy_reloc_p (ebl, GELF_R_TYPE (rela->r_info))) |
| 594 | return true; |
| 595 | } |
| 596 | } |
| 597 | |
| 598 | return false; |
| 599 | } |
| 600 | |
| 601 | |
| 602 | static int |
| 603 | regioncompare (const void *p1, const void *p2) |
| 604 | { |
| 605 | const struct region *r1 = (const struct region *) p1; |
| 606 | const struct region *r2 = (const struct region *) p2; |
| 607 | |
| 608 | if (r1->from < r2->from) |
| 609 | return -1; |
| 610 | return 1; |
| 611 | } |