Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1 | /* Combine stripped files with separate symbols and debug information. |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 2 | Copyright (C) 2007-2012, 2014 Red Hat, Inc. |
| 3 | This file is part of elfutils. |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 4 | Written by Roland McGrath <roland@redhat.com>, 2007. |
| 5 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 6 | This file is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 3 of the License, or |
| 9 | (at your option) any later version. |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 10 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 11 | elfutils is distributed in the hope that it will be useful, but |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 12 | WITHOUT ANY WARRANTY; without even the implied warranty of |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 15 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 18 | |
| 19 | /* TODO: |
| 20 | |
| 21 | * SHX_XINDEX |
| 22 | |
| 23 | * prelink vs .debug_* linked addresses |
| 24 | |
| 25 | */ |
| 26 | |
| 27 | #ifdef HAVE_CONFIG_H |
| 28 | # include <config.h> |
| 29 | #endif |
| 30 | |
| 31 | #include <argp.h> |
| 32 | #include <assert.h> |
| 33 | #include <errno.h> |
| 34 | #include <error.h> |
| 35 | #include <fcntl.h> |
| 36 | #include <fnmatch.h> |
| 37 | #include <libintl.h> |
| 38 | #include <locale.h> |
| 39 | #include <mcheck.h> |
| 40 | #include <stdbool.h> |
| 41 | #include <stdio.h> |
| 42 | #include <stdio_ext.h> |
| 43 | #include <inttypes.h> |
| 44 | #include <stdlib.h> |
| 45 | #include <string.h> |
| 46 | #include <unistd.h> |
| 47 | #include <sys/stat.h> |
| 48 | |
| 49 | #include <gelf.h> |
| 50 | #include <libebl.h> |
| 51 | #include <libdwfl.h> |
| 52 | #include "system.h" |
| 53 | |
| 54 | #ifndef _ |
| 55 | # define _(str) gettext (str) |
| 56 | #endif |
| 57 | |
| 58 | /* Name and version of program. */ |
| 59 | static void print_version (FILE *stream, struct argp_state *state); |
| 60 | ARGP_PROGRAM_VERSION_HOOK_DEF = print_version; |
| 61 | |
| 62 | /* Bug report address. */ |
| 63 | ARGP_PROGRAM_BUG_ADDRESS_DEF = PACKAGE_BUGREPORT; |
| 64 | |
| 65 | /* Definitions of arguments for argp functions. */ |
| 66 | static const struct argp_option options[] = |
| 67 | { |
| 68 | /* Group 2 will follow group 1 from dwfl_standard_argp. */ |
| 69 | { "match-file-names", 'f', NULL, 0, |
| 70 | N_("Match MODULE against file names, not module names"), 2 }, |
| 71 | { "ignore-missing", 'i', NULL, 0, N_("Silently skip unfindable files"), 0 }, |
| 72 | |
| 73 | { NULL, 0, NULL, 0, N_("Output options:"), 0 }, |
| 74 | { "output", 'o', "FILE", 0, N_("Place output into FILE"), 0 }, |
| 75 | { "output-directory", 'd', "DIRECTORY", |
| 76 | 0, N_("Create multiple output files under DIRECTORY"), 0 }, |
| 77 | { "module-names", 'm', NULL, 0, N_("Use module rather than file names"), 0 }, |
| 78 | { "all", 'a', NULL, 0, |
| 79 | N_("Create output for modules that have no separate debug information"), |
| 80 | 0 }, |
| 81 | { "relocate", 'R', NULL, 0, |
| 82 | N_("Apply relocations to section contents in ET_REL files"), 0 }, |
| 83 | { "list-only", 'n', NULL, 0, |
| 84 | N_("Only list module and file names, build IDs"), 0 }, |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 85 | { "force", 'F', NULL, 0, |
| 86 | N_("Force combining files even if some ELF headers don't seem to match"), |
| 87 | 0 }, |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 88 | { NULL, 0, NULL, 0, NULL, 0 } |
| 89 | }; |
| 90 | |
| 91 | struct arg_info |
| 92 | { |
| 93 | const char *output_file; |
| 94 | const char *output_dir; |
| 95 | Dwfl *dwfl; |
| 96 | char **args; |
| 97 | bool list; |
| 98 | bool all; |
| 99 | bool ignore; |
| 100 | bool modnames; |
| 101 | bool match_files; |
| 102 | bool relocate; |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 103 | bool force; |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 104 | }; |
| 105 | |
| 106 | /* Handle program arguments. */ |
| 107 | static error_t |
| 108 | parse_opt (int key, char *arg, struct argp_state *state) |
| 109 | { |
| 110 | struct arg_info *info = state->input; |
| 111 | |
| 112 | switch (key) |
| 113 | { |
| 114 | case ARGP_KEY_INIT: |
| 115 | state->child_inputs[0] = &info->dwfl; |
| 116 | break; |
| 117 | |
| 118 | case 'o': |
| 119 | if (info->output_file != NULL) |
| 120 | { |
| 121 | argp_error (state, _("-o option specified twice")); |
| 122 | return EINVAL; |
| 123 | } |
| 124 | info->output_file = arg; |
| 125 | break; |
| 126 | |
| 127 | case 'd': |
| 128 | if (info->output_dir != NULL) |
| 129 | { |
| 130 | argp_error (state, _("-d option specified twice")); |
| 131 | return EINVAL; |
| 132 | } |
| 133 | info->output_dir = arg; |
| 134 | break; |
| 135 | |
| 136 | case 'm': |
| 137 | info->modnames = true; |
| 138 | break; |
| 139 | case 'f': |
| 140 | info->match_files = true; |
| 141 | break; |
| 142 | case 'a': |
| 143 | info->all = true; |
| 144 | break; |
| 145 | case 'i': |
| 146 | info->ignore = true; |
| 147 | break; |
| 148 | case 'n': |
| 149 | info->list = true; |
| 150 | break; |
| 151 | case 'R': |
| 152 | info->relocate = true; |
| 153 | break; |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 154 | case 'F': |
| 155 | info->force = true; |
| 156 | break; |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 157 | |
| 158 | case ARGP_KEY_ARGS: |
| 159 | case ARGP_KEY_NO_ARGS: |
| 160 | /* We "consume" all the arguments here. */ |
| 161 | info->args = &state->argv[state->next]; |
| 162 | |
| 163 | if (info->output_file != NULL && info->output_dir != NULL) |
| 164 | { |
| 165 | argp_error (state, _("only one of -o or -d allowed")); |
| 166 | return EINVAL; |
| 167 | } |
| 168 | |
| 169 | if (info->list && (info->dwfl == NULL |
| 170 | || info->output_dir != NULL |
| 171 | || info->output_file != NULL)) |
| 172 | { |
| 173 | argp_error (state, |
| 174 | _("-n cannot be used with explicit files or -o or -d")); |
| 175 | return EINVAL; |
| 176 | } |
| 177 | |
| 178 | if (info->output_dir != NULL) |
| 179 | { |
| 180 | struct stat64 st; |
| 181 | error_t fail = 0; |
| 182 | if (stat64 (info->output_dir, &st) < 0) |
| 183 | fail = errno; |
| 184 | else if (!S_ISDIR (st.st_mode)) |
| 185 | fail = ENOTDIR; |
| 186 | if (fail) |
| 187 | { |
| 188 | argp_failure (state, EXIT_FAILURE, fail, |
| 189 | _("output directory '%s'"), info->output_dir); |
| 190 | return fail; |
| 191 | } |
| 192 | } |
| 193 | |
| 194 | if (info->dwfl == NULL) |
| 195 | { |
| 196 | if (state->next + 2 != state->argc) |
| 197 | { |
| 198 | argp_error (state, _("exactly two file arguments are required")); |
| 199 | return EINVAL; |
| 200 | } |
| 201 | |
| 202 | if (info->ignore || info->all || info->modnames || info->relocate) |
| 203 | { |
| 204 | argp_error (state, _("\ |
| 205 | -m, -a, -R, and -i options not allowed with explicit files")); |
| 206 | return EINVAL; |
| 207 | } |
| 208 | |
| 209 | /* Bail out immediately to prevent dwfl_standard_argp's parser |
| 210 | from defaulting to "-e a.out". */ |
| 211 | return ENOSYS; |
| 212 | } |
| 213 | else if (info->output_file == NULL && info->output_dir == NULL |
| 214 | && !info->list) |
| 215 | { |
| 216 | argp_error (state, |
| 217 | _("-o or -d is required when using implicit files")); |
| 218 | return EINVAL; |
| 219 | } |
| 220 | break; |
| 221 | |
| 222 | default: |
| 223 | return ARGP_ERR_UNKNOWN; |
| 224 | } |
| 225 | return 0; |
| 226 | } |
| 227 | |
| 228 | /* Print the version information. */ |
| 229 | static void |
| 230 | print_version (FILE *stream, struct argp_state *state __attribute__ ((unused))) |
| 231 | { |
| 232 | fprintf (stream, "unstrip (%s) %s\n", PACKAGE_NAME, PACKAGE_VERSION); |
| 233 | fprintf (stream, _("\ |
| 234 | Copyright (C) %s Red Hat, Inc.\n\ |
| 235 | This is free software; see the source for copying conditions. There is NO\n\ |
| 236 | warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\ |
| 237 | "), "2012"); |
| 238 | fprintf (stream, gettext ("Written by %s.\n"), "Roland McGrath"); |
| 239 | } |
| 240 | |
| 241 | #define ELF_CHECK(call, msg) \ |
| 242 | do \ |
| 243 | { \ |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 244 | if (unlikely (!(call))) \ |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 245 | error (EXIT_FAILURE, 0, msg, elf_errmsg (-1)); \ |
| 246 | } while (0) |
| 247 | |
| 248 | /* Copy INELF to newly-created OUTELF, exit via error for any problems. */ |
| 249 | static void |
| 250 | copy_elf (Elf *outelf, Elf *inelf) |
| 251 | { |
| 252 | ELF_CHECK (gelf_newehdr (outelf, gelf_getclass (inelf)), |
| 253 | _("cannot create ELF header: %s")); |
| 254 | |
| 255 | GElf_Ehdr ehdr_mem; |
| 256 | GElf_Ehdr *ehdr = gelf_getehdr (inelf, &ehdr_mem); |
| 257 | ELF_CHECK (gelf_update_ehdr (outelf, ehdr), |
| 258 | _("cannot copy ELF header: %s")); |
| 259 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 260 | size_t phnum; |
| 261 | ELF_CHECK (elf_getphdrnum (inelf, &phnum) == 0, |
| 262 | _("cannot get number of program headers: %s")); |
| 263 | |
| 264 | if (phnum > 0) |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 265 | { |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 266 | ELF_CHECK (gelf_newphdr (outelf, phnum), |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 267 | _("cannot create program headers: %s")); |
| 268 | |
| 269 | GElf_Phdr phdr_mem; |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 270 | for (size_t i = 0; i < phnum; ++i) |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 271 | ELF_CHECK (gelf_update_phdr (outelf, i, |
| 272 | gelf_getphdr (inelf, i, &phdr_mem)), |
| 273 | _("cannot copy program header: %s")); |
| 274 | } |
| 275 | |
| 276 | Elf_Scn *scn = NULL; |
| 277 | while ((scn = elf_nextscn (inelf, scn)) != NULL) |
| 278 | { |
| 279 | Elf_Scn *newscn = elf_newscn (outelf); |
| 280 | |
| 281 | GElf_Shdr shdr_mem; |
| 282 | ELF_CHECK (gelf_update_shdr (newscn, gelf_getshdr (scn, &shdr_mem)), |
| 283 | _("cannot copy section header: %s")); |
| 284 | |
| 285 | Elf_Data *data = elf_getdata (scn, NULL); |
| 286 | ELF_CHECK (data != NULL, _("cannot get section data: %s")); |
| 287 | Elf_Data *newdata = elf_newdata (newscn); |
| 288 | ELF_CHECK (newdata != NULL, _("cannot copy section data: %s")); |
| 289 | *newdata = *data; |
| 290 | elf_flagdata (newdata, ELF_C_SET, ELF_F_DIRTY); |
| 291 | } |
| 292 | } |
| 293 | |
| 294 | /* Create directories containing PATH. */ |
| 295 | static void |
| 296 | make_directories (const char *path) |
| 297 | { |
| 298 | const char *lastslash = strrchr (path, '/'); |
| 299 | if (lastslash == NULL) |
| 300 | return; |
| 301 | |
| 302 | while (lastslash > path && lastslash[-1] == '/') |
| 303 | --lastslash; |
| 304 | if (lastslash == path) |
| 305 | return; |
| 306 | |
| 307 | char *dir = strndupa (path, lastslash - path); |
| 308 | while (mkdir (dir, 0777) < 0 && errno != EEXIST) |
| 309 | if (errno == ENOENT) |
| 310 | make_directories (dir); |
| 311 | else |
| 312 | error (EXIT_FAILURE, errno, _("cannot create directory '%s'"), dir); |
| 313 | } |
| 314 | |
| 315 | |
| 316 | /* The binutils linker leaves gratuitous section symbols in .symtab |
| 317 | that strip has to remove. Older linkers likewise include a |
| 318 | symbol for every section, even unallocated ones, in .dynsym. |
| 319 | Because of this, the related sections can shrink in the stripped |
| 320 | file from their original size. Older versions of strip do not |
| 321 | adjust the sh_size field in the debuginfo file's SHT_NOBITS |
| 322 | version of the section header, so it can appear larger. */ |
| 323 | static bool |
| 324 | section_can_shrink (const GElf_Shdr *shdr) |
| 325 | { |
| 326 | switch (shdr->sh_type) |
| 327 | { |
| 328 | case SHT_SYMTAB: |
| 329 | case SHT_DYNSYM: |
| 330 | case SHT_HASH: |
| 331 | case SHT_GNU_versym: |
| 332 | return true; |
| 333 | } |
| 334 | return false; |
| 335 | } |
| 336 | |
| 337 | /* See if this symbol table has a leading section symbol for every single |
| 338 | section, in order. The binutils linker produces this. While we're here, |
| 339 | update each section symbol's st_value. */ |
| 340 | static size_t |
| 341 | symtab_count_leading_section_symbols (Elf *elf, Elf_Scn *scn, size_t shnum, |
| 342 | Elf_Data *newsymdata) |
| 343 | { |
| 344 | Elf_Data *data = elf_getdata (scn, NULL); |
| 345 | Elf_Data *shndxdata = NULL; /* XXX */ |
| 346 | |
| 347 | for (size_t i = 1; i < shnum; ++i) |
| 348 | { |
| 349 | GElf_Sym sym_mem; |
| 350 | GElf_Word shndx = SHN_UNDEF; |
| 351 | GElf_Sym *sym = gelf_getsymshndx (data, shndxdata, i, &sym_mem, &shndx); |
| 352 | ELF_CHECK (sym != NULL, _("cannot get symbol table entry: %s")); |
| 353 | |
| 354 | GElf_Shdr shdr_mem; |
| 355 | GElf_Shdr *shdr = gelf_getshdr (elf_getscn (elf, i), &shdr_mem); |
| 356 | ELF_CHECK (shdr != NULL, _("cannot get section header: %s")); |
| 357 | |
| 358 | if (sym->st_shndx != SHN_XINDEX) |
| 359 | shndx = sym->st_shndx; |
| 360 | |
| 361 | if (shndx != i || GELF_ST_TYPE (sym->st_info) != STT_SECTION) |
| 362 | return i; |
| 363 | |
| 364 | sym->st_value = shdr->sh_addr; |
| 365 | if (sym->st_shndx != SHN_XINDEX) |
| 366 | shndx = SHN_UNDEF; |
| 367 | ELF_CHECK (gelf_update_symshndx (newsymdata, shndxdata, i, sym, shndx), |
| 368 | _("cannot update symbol table: %s")); |
| 369 | } |
| 370 | |
| 371 | return shnum; |
| 372 | } |
| 373 | |
| 374 | static void |
| 375 | update_shdr (Elf_Scn *outscn, GElf_Shdr *newshdr) |
| 376 | { |
| 377 | ELF_CHECK (gelf_update_shdr (outscn, newshdr), |
| 378 | _("cannot update section header: %s")); |
| 379 | } |
| 380 | |
| 381 | /* We expanded the output section, so update its header. */ |
| 382 | static void |
| 383 | update_sh_size (Elf_Scn *outscn, const Elf_Data *data) |
| 384 | { |
| 385 | GElf_Shdr shdr_mem; |
| 386 | GElf_Shdr *newshdr = gelf_getshdr (outscn, &shdr_mem); |
| 387 | ELF_CHECK (newshdr != NULL, _("cannot get section header: %s")); |
| 388 | |
| 389 | newshdr->sh_size = data->d_size; |
| 390 | |
| 391 | update_shdr (outscn, newshdr); |
| 392 | } |
| 393 | |
| 394 | /* Update relocation sections using the symbol table. */ |
| 395 | static void |
| 396 | adjust_relocs (Elf_Scn *outscn, Elf_Scn *inscn, const GElf_Shdr *shdr, |
| 397 | size_t map[], const GElf_Shdr *symshdr) |
| 398 | { |
| 399 | Elf_Data *data = elf_getdata (outscn, NULL); |
| 400 | |
| 401 | inline void adjust_reloc (GElf_Xword *info) |
| 402 | { |
| 403 | size_t ndx = GELF_R_SYM (*info); |
| 404 | if (ndx != STN_UNDEF) |
| 405 | *info = GELF_R_INFO (map[ndx - 1], GELF_R_TYPE (*info)); |
| 406 | } |
| 407 | |
| 408 | switch (shdr->sh_type) |
| 409 | { |
| 410 | case SHT_REL: |
| 411 | for (size_t i = 0; i < shdr->sh_size / shdr->sh_entsize; ++i) |
| 412 | { |
| 413 | GElf_Rel rel_mem; |
| 414 | GElf_Rel *rel = gelf_getrel (data, i, &rel_mem); |
| 415 | adjust_reloc (&rel->r_info); |
| 416 | ELF_CHECK (gelf_update_rel (data, i, rel), |
| 417 | _("cannot update relocation: %s")); |
| 418 | } |
| 419 | break; |
| 420 | |
| 421 | case SHT_RELA: |
| 422 | for (size_t i = 0; i < shdr->sh_size / shdr->sh_entsize; ++i) |
| 423 | { |
| 424 | GElf_Rela rela_mem; |
| 425 | GElf_Rela *rela = gelf_getrela (data, i, &rela_mem); |
| 426 | adjust_reloc (&rela->r_info); |
| 427 | ELF_CHECK (gelf_update_rela (data, i, rela), |
| 428 | _("cannot update relocation: %s")); |
| 429 | } |
| 430 | break; |
| 431 | |
| 432 | case SHT_GROUP: |
| 433 | { |
| 434 | GElf_Shdr shdr_mem; |
| 435 | GElf_Shdr *newshdr = gelf_getshdr (outscn, &shdr_mem); |
| 436 | ELF_CHECK (newshdr != NULL, _("cannot get section header: %s")); |
| 437 | if (newshdr->sh_info != STN_UNDEF) |
| 438 | { |
| 439 | newshdr->sh_info = map[newshdr->sh_info - 1]; |
| 440 | update_shdr (outscn, newshdr); |
| 441 | } |
| 442 | break; |
| 443 | } |
| 444 | |
| 445 | case SHT_HASH: |
| 446 | /* We must expand the table and rejigger its contents. */ |
| 447 | { |
| 448 | const size_t nsym = symshdr->sh_size / symshdr->sh_entsize; |
| 449 | const size_t onent = shdr->sh_size / shdr->sh_entsize; |
| 450 | assert (data->d_size == shdr->sh_size); |
| 451 | |
| 452 | #define CONVERT_HASH(Hash_Word) \ |
| 453 | { \ |
| 454 | const Hash_Word *const old_hash = data->d_buf; \ |
| 455 | const size_t nbucket = old_hash[0]; \ |
| 456 | const size_t nchain = old_hash[1]; \ |
| 457 | const Hash_Word *const old_bucket = &old_hash[2]; \ |
| 458 | const Hash_Word *const old_chain = &old_bucket[nbucket]; \ |
| 459 | assert (onent == 2 + nbucket + nchain); \ |
| 460 | \ |
| 461 | const size_t nent = 2 + nbucket + nsym; \ |
| 462 | Hash_Word *const new_hash = xcalloc (nent, sizeof new_hash[0]); \ |
| 463 | Hash_Word *const new_bucket = &new_hash[2]; \ |
| 464 | Hash_Word *const new_chain = &new_bucket[nbucket]; \ |
| 465 | \ |
| 466 | new_hash[0] = nbucket; \ |
| 467 | new_hash[1] = nsym; \ |
| 468 | for (size_t i = 0; i < nbucket; ++i) \ |
| 469 | if (old_bucket[i] != STN_UNDEF) \ |
| 470 | new_bucket[i] = map[old_bucket[i] - 1]; \ |
| 471 | \ |
| 472 | for (size_t i = 1; i < nchain; ++i) \ |
| 473 | if (old_chain[i] != STN_UNDEF) \ |
| 474 | new_chain[map[i - 1]] = map[old_chain[i] - 1]; \ |
| 475 | \ |
| 476 | data->d_buf = new_hash; \ |
| 477 | data->d_size = nent * sizeof new_hash[0]; \ |
| 478 | } |
| 479 | |
| 480 | switch (shdr->sh_entsize) |
| 481 | { |
| 482 | case 4: |
| 483 | CONVERT_HASH (Elf32_Word); |
| 484 | break; |
| 485 | case 8: |
| 486 | CONVERT_HASH (Elf64_Xword); |
| 487 | break; |
| 488 | default: |
| 489 | abort (); |
| 490 | } |
| 491 | |
| 492 | elf_flagdata (data, ELF_C_SET, ELF_F_DIRTY); |
| 493 | update_sh_size (outscn, data); |
| 494 | |
| 495 | #undef CONVERT_HASH |
| 496 | } |
| 497 | break; |
| 498 | |
| 499 | case SHT_GNU_versym: |
| 500 | /* We must expand the table and move its elements around. */ |
| 501 | { |
| 502 | const size_t nent = symshdr->sh_size / symshdr->sh_entsize; |
| 503 | const size_t onent = shdr->sh_size / shdr->sh_entsize; |
| 504 | assert (nent >= onent); |
| 505 | |
| 506 | /* We don't bother using gelf_update_versym because there is |
| 507 | really no conversion to be done. */ |
| 508 | assert (sizeof (Elf32_Versym) == sizeof (GElf_Versym)); |
| 509 | assert (sizeof (Elf64_Versym) == sizeof (GElf_Versym)); |
| 510 | GElf_Versym *versym = xcalloc (nent, sizeof versym[0]); |
| 511 | |
| 512 | for (size_t i = 1; i < onent; ++i) |
| 513 | { |
| 514 | GElf_Versym *v = gelf_getversym (data, i, &versym[map[i - 1]]); |
| 515 | ELF_CHECK (v != NULL, _("cannot get symbol version: %s")); |
| 516 | } |
| 517 | |
| 518 | data->d_buf = versym; |
| 519 | data->d_size = nent * shdr->sh_entsize; |
| 520 | elf_flagdata (data, ELF_C_SET, ELF_F_DIRTY); |
| 521 | update_sh_size (outscn, data); |
| 522 | } |
| 523 | break; |
| 524 | |
| 525 | default: |
| 526 | error (EXIT_FAILURE, 0, |
| 527 | _("unexpected section type in [%Zu] with sh_link to symtab"), |
| 528 | elf_ndxscn (inscn)); |
| 529 | } |
| 530 | } |
| 531 | |
| 532 | /* Adjust all the relocation sections in the file. */ |
| 533 | static void |
| 534 | adjust_all_relocs (Elf *elf, Elf_Scn *symtab, const GElf_Shdr *symshdr, |
| 535 | size_t map[]) |
| 536 | { |
| 537 | size_t new_sh_link = elf_ndxscn (symtab); |
| 538 | Elf_Scn *scn = NULL; |
| 539 | while ((scn = elf_nextscn (elf, scn)) != NULL) |
| 540 | if (scn != symtab) |
| 541 | { |
| 542 | GElf_Shdr shdr_mem; |
| 543 | GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); |
| 544 | ELF_CHECK (shdr != NULL, _("cannot get section header: %s")); |
| 545 | if (shdr->sh_type != SHT_NOBITS && shdr->sh_link == new_sh_link) |
| 546 | adjust_relocs (scn, scn, shdr, map, symshdr); |
| 547 | } |
| 548 | } |
| 549 | |
| 550 | /* The original file probably had section symbols for all of its |
| 551 | sections, even the unallocated ones. To match it as closely as |
| 552 | possible, add in section symbols for the added sections. */ |
| 553 | static Elf_Data * |
| 554 | add_new_section_symbols (Elf_Scn *old_symscn, size_t old_shnum, |
| 555 | Elf *elf, bool rel, Elf_Scn *symscn, size_t shnum) |
| 556 | { |
| 557 | const size_t added = shnum - old_shnum; |
| 558 | |
| 559 | GElf_Shdr shdr_mem; |
| 560 | GElf_Shdr *shdr = gelf_getshdr (symscn, &shdr_mem); |
| 561 | ELF_CHECK (shdr != NULL, _("cannot get section header: %s")); |
| 562 | |
| 563 | const size_t nsym = shdr->sh_size / shdr->sh_entsize; |
| 564 | size_t symndx_map[nsym - 1]; |
| 565 | |
| 566 | shdr->sh_info += added; |
| 567 | shdr->sh_size += added * shdr->sh_entsize; |
| 568 | update_shdr (symscn, shdr); |
| 569 | |
| 570 | Elf_Data *symdata = elf_getdata (symscn, NULL); |
| 571 | Elf_Data *shndxdata = NULL; /* XXX */ |
| 572 | |
| 573 | symdata->d_size = shdr->sh_size; |
| 574 | symdata->d_buf = xmalloc (symdata->d_size); |
| 575 | |
| 576 | /* Copy the existing section symbols. */ |
| 577 | Elf_Data *old_symdata = elf_getdata (old_symscn, NULL); |
| 578 | for (size_t i = 0; i < old_shnum; ++i) |
| 579 | { |
| 580 | GElf_Sym sym_mem; |
| 581 | GElf_Word shndx = SHN_UNDEF; |
| 582 | GElf_Sym *sym = gelf_getsymshndx (old_symdata, shndxdata, |
| 583 | i, &sym_mem, &shndx); |
| 584 | ELF_CHECK (gelf_update_symshndx (symdata, shndxdata, i, |
| 585 | sym, shndx), |
| 586 | _("cannot update symbol table: %s")); |
| 587 | |
| 588 | if (i > 0) |
| 589 | symndx_map[i - 1] = i; |
| 590 | } |
| 591 | |
| 592 | /* Add in the new section symbols. */ |
| 593 | for (size_t i = old_shnum; i < shnum; ++i) |
| 594 | { |
| 595 | GElf_Shdr i_shdr_mem; |
| 596 | GElf_Shdr *i_shdr = gelf_getshdr (elf_getscn (elf, i), &i_shdr_mem); |
| 597 | ELF_CHECK (i_shdr != NULL, _("cannot get section header: %s")); |
| 598 | GElf_Sym sym = |
| 599 | { |
| 600 | .st_value = rel ? 0 : i_shdr->sh_addr, |
| 601 | .st_info = GELF_ST_INFO (STB_LOCAL, STT_SECTION), |
| 602 | .st_shndx = i < SHN_LORESERVE ? i : SHN_XINDEX |
| 603 | }; |
| 604 | GElf_Word shndx = i < SHN_LORESERVE ? SHN_UNDEF : i; |
| 605 | ELF_CHECK (gelf_update_symshndx (symdata, shndxdata, i, |
| 606 | &sym, shndx), |
| 607 | _("cannot update symbol table: %s")); |
| 608 | } |
| 609 | |
| 610 | /* Now copy the rest of the existing symbols. */ |
| 611 | for (size_t i = old_shnum; i < nsym; ++i) |
| 612 | { |
| 613 | GElf_Sym sym_mem; |
| 614 | GElf_Word shndx = SHN_UNDEF; |
| 615 | GElf_Sym *sym = gelf_getsymshndx (old_symdata, shndxdata, |
| 616 | i, &sym_mem, &shndx); |
| 617 | ELF_CHECK (gelf_update_symshndx (symdata, shndxdata, |
| 618 | i + added, sym, shndx), |
| 619 | _("cannot update symbol table: %s")); |
| 620 | |
| 621 | symndx_map[i - 1] = i + added; |
| 622 | } |
| 623 | |
| 624 | /* Adjust any relocations referring to the old symbol table. */ |
| 625 | adjust_all_relocs (elf, symscn, shdr, symndx_map); |
| 626 | |
| 627 | return symdata; |
| 628 | } |
| 629 | |
| 630 | /* This has the side effect of updating STT_SECTION symbols' values, |
| 631 | in case of prelink adjustments. */ |
| 632 | static Elf_Data * |
| 633 | check_symtab_section_symbols (Elf *elf, bool rel, Elf_Scn *scn, |
| 634 | size_t shnum, size_t shstrndx, |
| 635 | Elf_Scn *oscn, size_t oshnum, size_t oshstrndx, |
| 636 | size_t debuglink) |
| 637 | { |
| 638 | size_t n = symtab_count_leading_section_symbols (elf, oscn, oshnum, |
| 639 | elf_getdata (scn, NULL)); |
| 640 | |
| 641 | if (n == oshnum) |
| 642 | return add_new_section_symbols (oscn, n, elf, rel, scn, shnum); |
| 643 | |
| 644 | if (n == oshstrndx || (n == debuglink && n == oshstrndx - 1)) |
| 645 | return add_new_section_symbols (oscn, n, elf, rel, scn, shstrndx); |
| 646 | |
| 647 | return NULL; |
| 648 | } |
| 649 | |
| 650 | struct section |
| 651 | { |
| 652 | Elf_Scn *scn; |
| 653 | const char *name; |
| 654 | Elf_Scn *outscn; |
| 655 | struct Ebl_Strent *strent; |
| 656 | GElf_Shdr shdr; |
| 657 | }; |
| 658 | |
| 659 | static int |
| 660 | compare_alloc_sections (const struct section *s1, const struct section *s2, |
| 661 | bool rel) |
| 662 | { |
| 663 | if (!rel) |
| 664 | { |
| 665 | /* Sort by address. */ |
| 666 | if (s1->shdr.sh_addr < s2->shdr.sh_addr) |
| 667 | return -1; |
| 668 | if (s1->shdr.sh_addr > s2->shdr.sh_addr) |
| 669 | return 1; |
| 670 | } |
| 671 | |
| 672 | /* At the same address, preserve original section order. */ |
| 673 | return (ssize_t) elf_ndxscn (s1->scn) - (ssize_t) elf_ndxscn (s2->scn); |
| 674 | } |
| 675 | |
| 676 | static int |
| 677 | compare_unalloc_sections (const GElf_Shdr *shdr1, const GElf_Shdr *shdr2, |
| 678 | const char *name1, const char *name2) |
| 679 | { |
| 680 | /* Sort by sh_flags as an arbitrary ordering. */ |
| 681 | if (shdr1->sh_flags < shdr2->sh_flags) |
| 682 | return -1; |
| 683 | if (shdr1->sh_flags > shdr2->sh_flags) |
| 684 | return 1; |
| 685 | |
| 686 | /* Sort by name as last resort. */ |
| 687 | return strcmp (name1, name2); |
| 688 | } |
| 689 | |
| 690 | static int |
| 691 | compare_sections (const void *a, const void *b, bool rel) |
| 692 | { |
| 693 | const struct section *s1 = a; |
| 694 | const struct section *s2 = b; |
| 695 | |
| 696 | /* Sort all non-allocated sections last. */ |
| 697 | if ((s1->shdr.sh_flags ^ s2->shdr.sh_flags) & SHF_ALLOC) |
| 698 | return (s1->shdr.sh_flags & SHF_ALLOC) ? -1 : 1; |
| 699 | |
| 700 | return ((s1->shdr.sh_flags & SHF_ALLOC) |
| 701 | ? compare_alloc_sections (s1, s2, rel) |
| 702 | : compare_unalloc_sections (&s1->shdr, &s2->shdr, |
| 703 | s1->name, s2->name)); |
| 704 | } |
| 705 | |
| 706 | static int |
| 707 | compare_sections_rel (const void *a, const void *b) |
| 708 | { |
| 709 | return compare_sections (a, b, true); |
| 710 | } |
| 711 | |
| 712 | static int |
| 713 | compare_sections_nonrel (const void *a, const void *b) |
| 714 | { |
| 715 | return compare_sections (a, b, false); |
| 716 | } |
| 717 | |
| 718 | |
| 719 | struct symbol |
| 720 | { |
| 721 | size_t *map; |
| 722 | |
| 723 | union |
| 724 | { |
| 725 | const char *name; |
| 726 | struct Ebl_Strent *strent; |
| 727 | }; |
| 728 | union |
| 729 | { |
| 730 | struct |
| 731 | { |
| 732 | GElf_Addr value; |
| 733 | GElf_Xword size; |
| 734 | GElf_Word shndx; |
| 735 | union |
| 736 | { |
| 737 | struct |
| 738 | { |
| 739 | uint8_t info; |
| 740 | uint8_t other; |
| 741 | } info; |
| 742 | int16_t compare; |
| 743 | }; |
| 744 | }; |
| 745 | |
| 746 | /* For a symbol discarded after first sort, this matches its better's |
| 747 | map pointer. */ |
| 748 | size_t *duplicate; |
| 749 | }; |
| 750 | }; |
| 751 | |
| 752 | /* Collect input symbols into our internal form. */ |
| 753 | static void |
| 754 | collect_symbols (Elf *outelf, bool rel, Elf_Scn *symscn, Elf_Scn *strscn, |
| 755 | const size_t nent, const GElf_Addr bias, |
| 756 | const size_t scnmap[], struct symbol *table, size_t *map, |
| 757 | struct section *split_bss) |
| 758 | { |
| 759 | Elf_Data *symdata = elf_getdata (symscn, NULL); |
| 760 | Elf_Data *strdata = elf_getdata (strscn, NULL); |
| 761 | Elf_Data *shndxdata = NULL; /* XXX */ |
| 762 | |
| 763 | for (size_t i = 1; i < nent; ++i) |
| 764 | { |
| 765 | GElf_Sym sym_mem; |
| 766 | GElf_Word shndx = SHN_UNDEF; |
| 767 | GElf_Sym *sym = gelf_getsymshndx (symdata, shndxdata, i, |
| 768 | &sym_mem, &shndx); |
| 769 | ELF_CHECK (sym != NULL, _("cannot get symbol table entry: %s")); |
| 770 | if (sym->st_shndx != SHN_XINDEX) |
| 771 | shndx = sym->st_shndx; |
| 772 | |
| 773 | if (sym->st_name >= strdata->d_size) |
| 774 | error (EXIT_FAILURE, 0, |
| 775 | _("invalid string offset in symbol [%Zu]"), i); |
| 776 | |
| 777 | struct symbol *s = &table[i - 1]; |
| 778 | s->map = &map[i - 1]; |
| 779 | s->name = strdata->d_buf + sym->st_name; |
| 780 | s->value = sym->st_value + bias; |
| 781 | s->size = sym->st_size; |
| 782 | s->shndx = shndx; |
| 783 | s->info.info = sym->st_info; |
| 784 | s->info.other = sym->st_other; |
| 785 | |
| 786 | if (scnmap != NULL && shndx != SHN_UNDEF && shndx < SHN_LORESERVE) |
| 787 | s->shndx = scnmap[shndx - 1]; |
| 788 | |
| 789 | if (GELF_ST_TYPE (s->info.info) == STT_SECTION && !rel) |
| 790 | { |
| 791 | /* Update the value to match the output section. */ |
| 792 | GElf_Shdr shdr_mem; |
| 793 | GElf_Shdr *shdr = gelf_getshdr (elf_getscn (outelf, s->shndx), |
| 794 | &shdr_mem); |
| 795 | ELF_CHECK (shdr != NULL, _("cannot get section header: %s")); |
| 796 | s->value = shdr->sh_addr; |
| 797 | } |
| 798 | else if (split_bss != NULL |
| 799 | && s->value < split_bss->shdr.sh_addr |
| 800 | && s->value >= split_bss[-1].shdr.sh_addr |
| 801 | && shndx == elf_ndxscn (split_bss->outscn)) |
| 802 | /* This symbol was in .bss and was split into .dynbss. */ |
| 803 | s->shndx = elf_ndxscn (split_bss[-1].outscn); |
| 804 | } |
| 805 | } |
| 806 | |
| 807 | |
| 808 | #define CMP(value) \ |
| 809 | if (s1->value < s2->value) \ |
| 810 | return -1; \ |
| 811 | if (s1->value > s2->value) \ |
| 812 | return 1 |
| 813 | |
| 814 | /* Compare symbols with a consistent ordering, |
| 815 | but one only meaningful for equality. */ |
| 816 | static int |
| 817 | compare_symbols (const void *a, const void *b) |
| 818 | { |
| 819 | const struct symbol *s1 = a; |
| 820 | const struct symbol *s2 = b; |
| 821 | |
| 822 | CMP (value); |
| 823 | CMP (size); |
| 824 | CMP (shndx); |
| 825 | |
| 826 | return (s1->compare - s2->compare) ?: strcmp (s1->name, s2->name); |
| 827 | } |
| 828 | |
| 829 | /* Compare symbols for output order after slots have been assigned. */ |
| 830 | static int |
| 831 | compare_symbols_output (const void *a, const void *b) |
| 832 | { |
| 833 | const struct symbol *s1 = a; |
| 834 | const struct symbol *s2 = b; |
| 835 | int cmp; |
| 836 | |
| 837 | /* Sort discarded symbols last. */ |
| 838 | cmp = (s1->name == NULL) - (s2->name == NULL); |
| 839 | |
| 840 | if (cmp == 0) |
| 841 | /* Local symbols must come first. */ |
| 842 | cmp = ((GELF_ST_BIND (s2->info.info) == STB_LOCAL) |
| 843 | - (GELF_ST_BIND (s1->info.info) == STB_LOCAL)); |
| 844 | |
| 845 | if (cmp == 0) |
| 846 | /* binutils always puts section symbols first. */ |
| 847 | cmp = ((GELF_ST_TYPE (s2->info.info) == STT_SECTION) |
| 848 | - (GELF_ST_TYPE (s1->info.info) == STT_SECTION)); |
| 849 | |
| 850 | if (cmp == 0) |
| 851 | { |
| 852 | if (GELF_ST_TYPE (s1->info.info) == STT_SECTION) |
| 853 | { |
| 854 | /* binutils always puts section symbols in section index order. */ |
| 855 | CMP (shndx); |
| 856 | else |
| 857 | assert (s1 == s2); |
| 858 | } |
| 859 | |
| 860 | /* Nothing really matters, so preserve the original order. */ |
| 861 | CMP (map); |
| 862 | else |
| 863 | assert (s1 == s2); |
| 864 | } |
| 865 | |
| 866 | return cmp; |
| 867 | } |
| 868 | |
| 869 | #undef CMP |
| 870 | |
| 871 | /* Return true iff the flags, size, and name match. */ |
| 872 | static bool |
| 873 | sections_match (const struct section *sections, size_t i, |
| 874 | const GElf_Shdr *shdr, const char *name) |
| 875 | { |
| 876 | return (sections[i].shdr.sh_flags == shdr->sh_flags |
| 877 | && (sections[i].shdr.sh_size == shdr->sh_size |
| 878 | || (sections[i].shdr.sh_size < shdr->sh_size |
| 879 | && section_can_shrink (§ions[i].shdr))) |
| 880 | && !strcmp (sections[i].name, name)); |
| 881 | } |
| 882 | |
| 883 | /* Locate a matching allocated section in SECTIONS. */ |
| 884 | static struct section * |
| 885 | find_alloc_section (const GElf_Shdr *shdr, GElf_Addr bias, const char *name, |
| 886 | struct section sections[], size_t nalloc) |
| 887 | { |
| 888 | const GElf_Addr addr = shdr->sh_addr + bias; |
| 889 | size_t l = 0, u = nalloc; |
| 890 | while (l < u) |
| 891 | { |
| 892 | size_t i = (l + u) / 2; |
| 893 | if (addr < sections[i].shdr.sh_addr) |
| 894 | u = i; |
| 895 | else if (addr > sections[i].shdr.sh_addr) |
| 896 | l = i + 1; |
| 897 | else |
| 898 | { |
| 899 | /* We've found allocated sections with this address. |
| 900 | Find one with matching size, flags, and name. */ |
| 901 | while (i > 0 && sections[i - 1].shdr.sh_addr == addr) |
| 902 | --i; |
| 903 | for (; i < nalloc && sections[i].shdr.sh_addr == addr; |
| 904 | ++i) |
| 905 | if (sections_match (sections, i, shdr, name)) |
| 906 | return §ions[i]; |
| 907 | break; |
| 908 | } |
| 909 | } |
| 910 | return NULL; |
| 911 | } |
| 912 | |
| 913 | static inline const char * |
| 914 | get_section_name (size_t ndx, const GElf_Shdr *shdr, const Elf_Data *shstrtab) |
| 915 | { |
| 916 | if (shdr->sh_name >= shstrtab->d_size) |
| 917 | error (EXIT_FAILURE, 0, _("cannot read section [%Zu] name: %s"), |
| 918 | ndx, elf_errmsg (-1)); |
| 919 | return shstrtab->d_buf + shdr->sh_name; |
| 920 | } |
| 921 | |
| 922 | /* Fix things up when prelink has moved some allocated sections around |
| 923 | and the debuginfo file's section headers no longer match up. |
| 924 | This fills in SECTIONS[0..NALLOC-1].outscn or exits. |
| 925 | If there was a .bss section that was split into two sections |
| 926 | with the new one preceding it in sh_addr, we return that pointer. */ |
| 927 | static struct section * |
| 928 | find_alloc_sections_prelink (Elf *debug, Elf_Data *debug_shstrtab, |
| 929 | Elf *main, const GElf_Ehdr *main_ehdr, |
| 930 | Elf_Data *main_shstrtab, GElf_Addr bias, |
| 931 | struct section *sections, |
| 932 | size_t nalloc, size_t nsections) |
| 933 | { |
| 934 | /* Clear assignments that might have been bogus. */ |
| 935 | for (size_t i = 0; i < nalloc; ++i) |
| 936 | sections[i].outscn = NULL; |
| 937 | |
| 938 | Elf_Scn *undo = NULL; |
| 939 | for (size_t i = nalloc; i < nsections; ++i) |
| 940 | { |
| 941 | const struct section *sec = §ions[i]; |
| 942 | if (sec->shdr.sh_type == SHT_PROGBITS |
| 943 | && !(sec->shdr.sh_flags & SHF_ALLOC) |
| 944 | && !strcmp (sec->name, ".gnu.prelink_undo")) |
| 945 | { |
| 946 | undo = sec->scn; |
| 947 | break; |
| 948 | } |
| 949 | } |
| 950 | |
| 951 | /* Find the original allocated sections before prelinking. */ |
| 952 | struct section *undo_sections = NULL; |
| 953 | size_t undo_nalloc = 0; |
| 954 | if (undo != NULL) |
| 955 | { |
| 956 | Elf_Data *undodata = elf_rawdata (undo, NULL); |
| 957 | ELF_CHECK (undodata != NULL, |
| 958 | _("cannot read '.gnu.prelink_undo' section: %s")); |
| 959 | |
| 960 | union |
| 961 | { |
| 962 | Elf32_Ehdr e32; |
| 963 | Elf64_Ehdr e64; |
| 964 | } ehdr; |
| 965 | Elf_Data dst = |
| 966 | { |
| 967 | .d_buf = &ehdr, |
| 968 | .d_size = sizeof ehdr, |
| 969 | .d_type = ELF_T_EHDR, |
| 970 | .d_version = EV_CURRENT |
| 971 | }; |
| 972 | Elf_Data src = *undodata; |
| 973 | src.d_size = gelf_fsize (main, ELF_T_EHDR, 1, EV_CURRENT); |
| 974 | src.d_type = ELF_T_EHDR; |
| 975 | ELF_CHECK (gelf_xlatetom (main, &dst, &src, |
| 976 | main_ehdr->e_ident[EI_DATA]) != NULL, |
| 977 | _("cannot read '.gnu.prelink_undo' section: %s")); |
| 978 | |
| 979 | uint_fast16_t phnum; |
| 980 | uint_fast16_t shnum; |
| 981 | if (ehdr.e32.e_ident[EI_CLASS] == ELFCLASS32) |
| 982 | { |
| 983 | phnum = ehdr.e32.e_phnum; |
| 984 | shnum = ehdr.e32.e_shnum; |
| 985 | } |
| 986 | else |
| 987 | { |
| 988 | phnum = ehdr.e64.e_phnum; |
| 989 | shnum = ehdr.e64.e_shnum; |
| 990 | } |
| 991 | |
| 992 | size_t phsize = gelf_fsize (main, ELF_T_PHDR, phnum, EV_CURRENT); |
| 993 | src.d_buf += src.d_size + phsize; |
| 994 | src.d_size = gelf_fsize (main, ELF_T_SHDR, shnum - 1, EV_CURRENT); |
| 995 | src.d_type = ELF_T_SHDR; |
| 996 | if ((size_t) (src.d_buf - undodata->d_buf) > undodata->d_size |
| 997 | || undodata->d_size - (src.d_buf - undodata->d_buf) != src.d_size) |
| 998 | error (EXIT_FAILURE, 0, _("invalid contents in '%s' section"), |
| 999 | ".gnu.prelink_undo"); |
| 1000 | |
| 1001 | union |
| 1002 | { |
| 1003 | Elf32_Shdr s32[shnum - 1]; |
| 1004 | Elf64_Shdr s64[shnum - 1]; |
| 1005 | } shdr; |
| 1006 | dst.d_buf = &shdr; |
| 1007 | dst.d_size = sizeof shdr; |
| 1008 | ELF_CHECK (gelf_xlatetom (main, &dst, &src, |
| 1009 | main_ehdr->e_ident[EI_DATA]) != NULL, |
| 1010 | _("cannot read '.gnu.prelink_undo' section: %s")); |
| 1011 | |
| 1012 | undo_sections = xmalloc ((shnum - 1) * sizeof undo_sections[0]); |
| 1013 | for (size_t i = 0; i < shnum - 1; ++i) |
| 1014 | { |
| 1015 | struct section *sec = &undo_sections[undo_nalloc]; |
| 1016 | if (ehdr.e32.e_ident[EI_CLASS] == ELFCLASS32) |
| 1017 | { |
| 1018 | #define COPY(field) sec->shdr.field = shdr.s32[i].field |
| 1019 | COPY (sh_name); |
| 1020 | COPY (sh_type); |
| 1021 | COPY (sh_flags); |
| 1022 | COPY (sh_addr); |
| 1023 | COPY (sh_offset); |
| 1024 | COPY (sh_size); |
| 1025 | COPY (sh_link); |
| 1026 | COPY (sh_info); |
| 1027 | COPY (sh_addralign); |
| 1028 | COPY (sh_entsize); |
| 1029 | #undef COPY |
| 1030 | } |
| 1031 | else |
| 1032 | sec->shdr = shdr.s64[i]; |
| 1033 | if (sec->shdr.sh_flags & SHF_ALLOC) |
| 1034 | { |
| 1035 | sec->shdr.sh_addr += bias; |
| 1036 | sec->name = get_section_name (i + 1, &sec->shdr, main_shstrtab); |
| 1037 | sec->scn = elf_getscn (main, i + 1); /* Really just for ndx. */ |
| 1038 | sec->outscn = NULL; |
| 1039 | sec->strent = NULL; |
| 1040 | ++undo_nalloc; |
| 1041 | } |
| 1042 | } |
| 1043 | qsort (undo_sections, undo_nalloc, |
| 1044 | sizeof undo_sections[0], compare_sections_nonrel); |
| 1045 | } |
| 1046 | |
| 1047 | bool fail = false; |
| 1048 | inline void check_match (bool match, Elf_Scn *scn, const char *name) |
| 1049 | { |
| 1050 | if (!match) |
| 1051 | { |
| 1052 | fail = true; |
| 1053 | error (0, 0, _("cannot find matching section for [%Zu] '%s'"), |
| 1054 | elf_ndxscn (scn), name); |
| 1055 | } |
| 1056 | } |
| 1057 | |
| 1058 | Elf_Scn *scn = NULL; |
| 1059 | while ((scn = elf_nextscn (debug, scn)) != NULL) |
| 1060 | { |
| 1061 | GElf_Shdr shdr_mem; |
| 1062 | GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); |
| 1063 | ELF_CHECK (shdr != NULL, _("cannot get section header: %s")); |
| 1064 | |
| 1065 | if (!(shdr->sh_flags & SHF_ALLOC)) |
| 1066 | continue; |
| 1067 | |
| 1068 | const char *name = get_section_name (elf_ndxscn (scn), shdr, |
| 1069 | debug_shstrtab); |
| 1070 | |
| 1071 | if (undo_sections != NULL) |
| 1072 | { |
| 1073 | struct section *sec = find_alloc_section (shdr, 0, name, |
| 1074 | undo_sections, |
| 1075 | undo_nalloc); |
| 1076 | if (sec != NULL) |
| 1077 | { |
| 1078 | sec->outscn = scn; |
| 1079 | continue; |
| 1080 | } |
| 1081 | } |
| 1082 | |
| 1083 | /* If there is no prelink info, we are just here to find |
| 1084 | the sections to give error messages about. */ |
| 1085 | for (size_t i = 0; shdr != NULL && i < nalloc; ++i) |
| 1086 | if (sections[i].outscn == scn) |
| 1087 | shdr = NULL; |
| 1088 | check_match (shdr == NULL, scn, name); |
| 1089 | } |
| 1090 | |
| 1091 | if (fail) |
| 1092 | exit (EXIT_FAILURE); |
| 1093 | |
| 1094 | /* Now we have lined up output sections for each of the original sections |
| 1095 | before prelinking. Translate those to the prelinked sections. |
| 1096 | This matches what prelink's undo_sections does. */ |
| 1097 | struct section *split_bss = NULL; |
| 1098 | for (size_t i = 0; i < undo_nalloc; ++i) |
| 1099 | { |
| 1100 | const struct section *undo_sec = &undo_sections[i]; |
| 1101 | |
| 1102 | const char *name = undo_sec->name; |
| 1103 | scn = undo_sec->scn; /* This is just for elf_ndxscn. */ |
| 1104 | |
| 1105 | for (size_t j = 0; j < nalloc; ++j) |
| 1106 | { |
| 1107 | struct section *sec = §ions[j]; |
| 1108 | #define RELA_SCALED(field) \ |
| 1109 | (2 * sec->shdr.field == 3 * undo_sec->shdr.field) |
| 1110 | if (sec->outscn == NULL |
| 1111 | && sec->shdr.sh_name == undo_sec->shdr.sh_name |
| 1112 | && sec->shdr.sh_flags == undo_sec->shdr.sh_flags |
| 1113 | && sec->shdr.sh_addralign == undo_sec->shdr.sh_addralign |
| 1114 | && (((sec->shdr.sh_type == undo_sec->shdr.sh_type |
| 1115 | && sec->shdr.sh_entsize == undo_sec->shdr.sh_entsize |
| 1116 | && (sec->shdr.sh_size == undo_sec->shdr.sh_size |
| 1117 | || (sec->shdr.sh_size > undo_sec->shdr.sh_size |
| 1118 | && main_ehdr->e_type == ET_EXEC |
| 1119 | && !strcmp (sec->name, ".dynstr")))) |
| 1120 | || (sec->shdr.sh_size == undo_sec->shdr.sh_size |
| 1121 | && ((sec->shdr.sh_entsize == undo_sec->shdr.sh_entsize |
| 1122 | && undo_sec->shdr.sh_type == SHT_NOBITS) |
| 1123 | || undo_sec->shdr.sh_type == SHT_PROGBITS) |
| 1124 | && !strcmp (sec->name, ".plt"))) |
| 1125 | || (sec->shdr.sh_type == SHT_RELA |
| 1126 | && undo_sec->shdr.sh_type == SHT_REL |
| 1127 | && RELA_SCALED (sh_entsize) && RELA_SCALED (sh_size)) |
| 1128 | || (sec->shdr.sh_entsize == undo_sec->shdr.sh_entsize |
| 1129 | && (sec->shdr.sh_type == undo_sec->shdr.sh_type |
| 1130 | || (sec->shdr.sh_type == SHT_PROGBITS |
| 1131 | && undo_sec->shdr.sh_type == SHT_NOBITS)) |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1132 | && sec->shdr.sh_size <= undo_sec->shdr.sh_size |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1133 | && (!strcmp (sec->name, ".bss") |
| 1134 | || !strcmp (sec->name, ".sbss")) |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1135 | && (sec->shdr.sh_size == undo_sec->shdr.sh_size |
| 1136 | || (split_bss = sec) > sections)))) |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1137 | { |
| 1138 | sec->outscn = undo_sec->outscn; |
| 1139 | undo_sec = NULL; |
| 1140 | break; |
| 1141 | } |
| 1142 | } |
| 1143 | |
| 1144 | check_match (undo_sec == NULL, scn, name); |
| 1145 | } |
| 1146 | |
| 1147 | free (undo_sections); |
| 1148 | |
| 1149 | if (fail) |
| 1150 | exit (EXIT_FAILURE); |
| 1151 | |
| 1152 | return split_bss; |
| 1153 | } |
| 1154 | |
| 1155 | /* Create new .shstrtab contents, subroutine of copy_elided_sections. |
| 1156 | This can't be open coded there and still use variable-length auto arrays, |
| 1157 | since the end of our block would free other VLAs too. */ |
| 1158 | static Elf_Data * |
| 1159 | new_shstrtab (Elf *unstripped, size_t unstripped_shnum, |
| 1160 | Elf_Data *shstrtab, size_t unstripped_shstrndx, |
| 1161 | struct section *sections, size_t stripped_shnum, |
| 1162 | struct Ebl_Strtab *strtab) |
| 1163 | { |
| 1164 | if (strtab == NULL) |
| 1165 | return NULL; |
| 1166 | |
| 1167 | struct Ebl_Strent *unstripped_strent[unstripped_shnum - 1]; |
| 1168 | memset (unstripped_strent, 0, sizeof unstripped_strent); |
| 1169 | for (struct section *sec = sections; |
| 1170 | sec < §ions[stripped_shnum - 1]; |
| 1171 | ++sec) |
| 1172 | if (sec->outscn != NULL) |
| 1173 | { |
| 1174 | if (sec->strent == NULL) |
| 1175 | { |
| 1176 | sec->strent = ebl_strtabadd (strtab, sec->name, 0); |
| 1177 | ELF_CHECK (sec->strent != NULL, |
| 1178 | _("cannot add section name to string table: %s")); |
| 1179 | } |
| 1180 | unstripped_strent[elf_ndxscn (sec->outscn) - 1] = sec->strent; |
| 1181 | } |
| 1182 | |
| 1183 | /* Add names of sections we aren't touching. */ |
| 1184 | for (size_t i = 0; i < unstripped_shnum - 1; ++i) |
| 1185 | if (unstripped_strent[i] == NULL) |
| 1186 | { |
| 1187 | Elf_Scn *scn = elf_getscn (unstripped, i + 1); |
| 1188 | GElf_Shdr shdr_mem; |
| 1189 | GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); |
| 1190 | const char *name = get_section_name (i + 1, shdr, shstrtab); |
| 1191 | unstripped_strent[i] = ebl_strtabadd (strtab, name, 0); |
| 1192 | ELF_CHECK (unstripped_strent[i] != NULL, |
| 1193 | _("cannot add section name to string table: %s")); |
| 1194 | } |
| 1195 | else |
| 1196 | unstripped_strent[i] = NULL; |
| 1197 | |
| 1198 | /* Now finalize the string table so we can get offsets. */ |
| 1199 | Elf_Data *strtab_data = elf_getdata (elf_getscn (unstripped, |
| 1200 | unstripped_shstrndx), NULL); |
| 1201 | ELF_CHECK (elf_flagdata (strtab_data, ELF_C_SET, ELF_F_DIRTY), |
| 1202 | _("cannot update section header string table data: %s")); |
| 1203 | ebl_strtabfinalize (strtab, strtab_data); |
| 1204 | |
| 1205 | /* Update the sh_name fields of sections we aren't modifying later. */ |
| 1206 | for (size_t i = 0; i < unstripped_shnum - 1; ++i) |
| 1207 | if (unstripped_strent[i] != NULL) |
| 1208 | { |
| 1209 | Elf_Scn *scn = elf_getscn (unstripped, i + 1); |
| 1210 | GElf_Shdr shdr_mem; |
| 1211 | GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); |
| 1212 | shdr->sh_name = ebl_strtaboffset (unstripped_strent[i]); |
| 1213 | if (i + 1 == unstripped_shstrndx) |
| 1214 | shdr->sh_size = strtab_data->d_size; |
| 1215 | update_shdr (scn, shdr); |
| 1216 | } |
| 1217 | |
| 1218 | return strtab_data; |
| 1219 | } |
| 1220 | |
| 1221 | /* Fill in any SHT_NOBITS sections in UNSTRIPPED by |
| 1222 | copying their contents and sh_type from STRIPPED. */ |
| 1223 | static void |
| 1224 | copy_elided_sections (Elf *unstripped, Elf *stripped, |
| 1225 | const GElf_Ehdr *stripped_ehdr, GElf_Addr bias) |
| 1226 | { |
| 1227 | size_t unstripped_shstrndx; |
| 1228 | ELF_CHECK (elf_getshdrstrndx (unstripped, &unstripped_shstrndx) == 0, |
| 1229 | _("cannot get section header string table section index: %s")); |
| 1230 | |
| 1231 | size_t stripped_shstrndx; |
| 1232 | ELF_CHECK (elf_getshdrstrndx (stripped, &stripped_shstrndx) == 0, |
| 1233 | _("cannot get section header string table section index: %s")); |
| 1234 | |
| 1235 | size_t unstripped_shnum; |
| 1236 | ELF_CHECK (elf_getshdrnum (unstripped, &unstripped_shnum) == 0, |
| 1237 | _("cannot get section count: %s")); |
| 1238 | |
| 1239 | size_t stripped_shnum; |
| 1240 | ELF_CHECK (elf_getshdrnum (stripped, &stripped_shnum) == 0, |
| 1241 | _("cannot get section count: %s")); |
| 1242 | |
| 1243 | if (unlikely (stripped_shnum > unstripped_shnum)) |
| 1244 | error (EXIT_FAILURE, 0, _("\ |
| 1245 | more sections in stripped file than debug file -- arguments reversed?")); |
| 1246 | |
| 1247 | /* Cache the stripped file's section details. */ |
| 1248 | struct section sections[stripped_shnum - 1]; |
| 1249 | Elf_Scn *scn = NULL; |
| 1250 | while ((scn = elf_nextscn (stripped, scn)) != NULL) |
| 1251 | { |
| 1252 | size_t i = elf_ndxscn (scn) - 1; |
| 1253 | GElf_Shdr *shdr = gelf_getshdr (scn, §ions[i].shdr); |
| 1254 | ELF_CHECK (shdr != NULL, _("cannot get section header: %s")); |
| 1255 | sections[i].name = elf_strptr (stripped, stripped_shstrndx, |
| 1256 | shdr->sh_name); |
| 1257 | if (sections[i].name == NULL) |
| 1258 | error (EXIT_FAILURE, 0, _("cannot read section [%Zu] name: %s"), |
| 1259 | elf_ndxscn (scn), elf_errmsg (-1)); |
| 1260 | sections[i].scn = scn; |
| 1261 | sections[i].outscn = NULL; |
| 1262 | sections[i].strent = NULL; |
| 1263 | } |
| 1264 | |
| 1265 | const struct section *stripped_symtab = NULL; |
| 1266 | |
| 1267 | /* Sort the sections, allocated by address and others after. */ |
| 1268 | qsort (sections, stripped_shnum - 1, sizeof sections[0], |
| 1269 | stripped_ehdr->e_type == ET_REL |
| 1270 | ? compare_sections_rel : compare_sections_nonrel); |
| 1271 | size_t nalloc = stripped_shnum - 1; |
| 1272 | while (nalloc > 0 && !(sections[nalloc - 1].shdr.sh_flags & SHF_ALLOC)) |
| 1273 | { |
| 1274 | --nalloc; |
| 1275 | if (sections[nalloc].shdr.sh_type == SHT_SYMTAB) |
| 1276 | stripped_symtab = §ions[nalloc]; |
| 1277 | } |
| 1278 | |
| 1279 | /* Locate a matching unallocated section in SECTIONS. */ |
| 1280 | inline struct section *find_unalloc_section (const GElf_Shdr *shdr, |
| 1281 | const char *name) |
| 1282 | { |
| 1283 | size_t l = nalloc, u = stripped_shnum - 1; |
| 1284 | while (l < u) |
| 1285 | { |
| 1286 | size_t i = (l + u) / 2; |
| 1287 | struct section *sec = §ions[i]; |
| 1288 | int cmp = compare_unalloc_sections (shdr, &sec->shdr, |
| 1289 | name, sec->name); |
| 1290 | if (cmp < 0) |
| 1291 | u = i; |
| 1292 | else if (cmp > 0) |
| 1293 | l = i + 1; |
| 1294 | else |
| 1295 | return sec; |
| 1296 | } |
| 1297 | return NULL; |
| 1298 | } |
| 1299 | |
| 1300 | Elf_Data *shstrtab = elf_getdata (elf_getscn (unstripped, |
| 1301 | unstripped_shstrndx), NULL); |
| 1302 | ELF_CHECK (shstrtab != NULL, |
| 1303 | _("cannot read section header string table: %s")); |
| 1304 | |
| 1305 | /* Match each debuginfo section with its corresponding stripped section. */ |
| 1306 | bool check_prelink = false; |
| 1307 | Elf_Scn *unstripped_symtab = NULL; |
| 1308 | size_t alloc_avail = 0; |
| 1309 | scn = NULL; |
| 1310 | while ((scn = elf_nextscn (unstripped, scn)) != NULL) |
| 1311 | { |
| 1312 | GElf_Shdr shdr_mem; |
| 1313 | GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); |
| 1314 | ELF_CHECK (shdr != NULL, _("cannot get section header: %s")); |
| 1315 | |
| 1316 | if (shdr->sh_type == SHT_SYMTAB) |
| 1317 | { |
| 1318 | unstripped_symtab = scn; |
| 1319 | continue; |
| 1320 | } |
| 1321 | |
| 1322 | const size_t ndx = elf_ndxscn (scn); |
| 1323 | if (ndx == unstripped_shstrndx) |
| 1324 | continue; |
| 1325 | |
| 1326 | const char *name = get_section_name (ndx, shdr, shstrtab); |
| 1327 | |
| 1328 | struct section *sec = NULL; |
| 1329 | if (shdr->sh_flags & SHF_ALLOC) |
| 1330 | { |
| 1331 | if (stripped_ehdr->e_type != ET_REL) |
| 1332 | { |
| 1333 | /* Look for the section that matches. */ |
| 1334 | sec = find_alloc_section (shdr, bias, name, sections, nalloc); |
| 1335 | if (sec == NULL) |
| 1336 | { |
| 1337 | /* We couldn't figure it out. It may be a prelink issue. */ |
| 1338 | check_prelink = true; |
| 1339 | continue; |
| 1340 | } |
| 1341 | } |
| 1342 | else |
| 1343 | { |
| 1344 | /* The sh_addr of allocated sections does not help us, |
| 1345 | but the order usually matches. */ |
| 1346 | if (likely (sections_match (sections, alloc_avail, shdr, name))) |
| 1347 | sec = §ions[alloc_avail++]; |
| 1348 | else |
| 1349 | for (size_t i = alloc_avail + 1; i < nalloc; ++i) |
| 1350 | if (sections_match (sections, i, shdr, name)) |
| 1351 | { |
| 1352 | sec = §ions[i]; |
| 1353 | break; |
| 1354 | } |
| 1355 | } |
| 1356 | } |
| 1357 | else |
| 1358 | { |
| 1359 | /* Look for the section that matches. */ |
| 1360 | sec = find_unalloc_section (shdr, name); |
| 1361 | if (sec == NULL) |
| 1362 | { |
| 1363 | /* An additional unallocated section is fine if not SHT_NOBITS. |
| 1364 | We looked it up anyway in case it's an unallocated section |
| 1365 | copied in both files (e.g. SHT_NOTE), and don't keep both. */ |
| 1366 | if (shdr->sh_type != SHT_NOBITS) |
| 1367 | continue; |
| 1368 | |
| 1369 | /* Somehow some old .debug files wound up with SHT_NOBITS |
| 1370 | .comment sections, so let those pass. */ |
| 1371 | if (!strcmp (name, ".comment")) |
| 1372 | continue; |
| 1373 | } |
| 1374 | } |
| 1375 | |
| 1376 | if (sec == NULL) |
| 1377 | error (EXIT_FAILURE, 0, |
| 1378 | _("cannot find matching section for [%Zu] '%s'"), |
| 1379 | elf_ndxscn (scn), name); |
| 1380 | |
| 1381 | sec->outscn = scn; |
| 1382 | } |
| 1383 | |
| 1384 | /* If that failed due to changes made by prelink, we take another tack. |
| 1385 | We keep track of a .bss section that was partly split into .dynbss |
| 1386 | so that collect_symbols can update symbols' st_shndx fields. */ |
| 1387 | struct section *split_bss = NULL; |
| 1388 | if (check_prelink) |
| 1389 | { |
| 1390 | Elf_Data *data = elf_getdata (elf_getscn (stripped, stripped_shstrndx), |
| 1391 | NULL); |
| 1392 | ELF_CHECK (data != NULL, |
| 1393 | _("cannot read section header string table: %s")); |
| 1394 | split_bss = find_alloc_sections_prelink (unstripped, shstrtab, |
| 1395 | stripped, stripped_ehdr, |
| 1396 | data, bias, sections, |
| 1397 | nalloc, stripped_shnum - 1); |
| 1398 | } |
| 1399 | |
| 1400 | /* Make sure each main file section has a place to go. */ |
| 1401 | const struct section *stripped_dynsym = NULL; |
| 1402 | size_t debuglink = SHN_UNDEF; |
| 1403 | size_t ndx_section[stripped_shnum - 1]; |
| 1404 | struct Ebl_Strtab *strtab = NULL; |
| 1405 | for (struct section *sec = sections; |
| 1406 | sec < §ions[stripped_shnum - 1]; |
| 1407 | ++sec) |
| 1408 | { |
| 1409 | size_t secndx = elf_ndxscn (sec->scn); |
| 1410 | |
| 1411 | if (sec->outscn == NULL) |
| 1412 | { |
| 1413 | /* We didn't find any corresponding section for this. */ |
| 1414 | |
| 1415 | if (secndx == stripped_shstrndx) |
| 1416 | { |
| 1417 | /* We only need one .shstrtab. */ |
| 1418 | ndx_section[secndx - 1] = unstripped_shstrndx; |
| 1419 | continue; |
| 1420 | } |
| 1421 | |
| 1422 | if (unstripped_symtab != NULL && sec == stripped_symtab) |
| 1423 | { |
| 1424 | /* We don't need a second symbol table. */ |
| 1425 | ndx_section[secndx - 1] = elf_ndxscn (unstripped_symtab); |
| 1426 | continue; |
| 1427 | } |
| 1428 | |
| 1429 | if (unstripped_symtab != NULL && stripped_symtab != NULL |
| 1430 | && secndx == stripped_symtab->shdr.sh_link) |
| 1431 | { |
| 1432 | /* ... nor its string table. */ |
| 1433 | GElf_Shdr shdr_mem; |
| 1434 | GElf_Shdr *shdr = gelf_getshdr (unstripped_symtab, &shdr_mem); |
| 1435 | ELF_CHECK (shdr != NULL, _("cannot get section header: %s")); |
| 1436 | ndx_section[secndx - 1] = shdr->sh_link; |
| 1437 | continue; |
| 1438 | } |
| 1439 | |
| 1440 | if (!(sec->shdr.sh_flags & SHF_ALLOC) |
| 1441 | && !strcmp (sec->name, ".gnu_debuglink")) |
| 1442 | { |
| 1443 | /* This was created by stripping. We don't want it. */ |
| 1444 | debuglink = secndx; |
| 1445 | ndx_section[secndx - 1] = SHN_UNDEF; |
| 1446 | continue; |
| 1447 | } |
| 1448 | |
| 1449 | sec->outscn = elf_newscn (unstripped); |
| 1450 | Elf_Data *newdata = elf_newdata (sec->outscn); |
| 1451 | ELF_CHECK (newdata != NULL && gelf_update_shdr (sec->outscn, |
| 1452 | &sec->shdr), |
| 1453 | _("cannot add new section: %s")); |
| 1454 | |
| 1455 | if (strtab == NULL) |
| 1456 | strtab = ebl_strtabinit (true); |
| 1457 | sec->strent = ebl_strtabadd (strtab, sec->name, 0); |
| 1458 | ELF_CHECK (sec->strent != NULL, |
| 1459 | _("cannot add section name to string table: %s")); |
| 1460 | } |
| 1461 | |
| 1462 | /* Cache the mapping of original section indices to output sections. */ |
| 1463 | ndx_section[secndx - 1] = elf_ndxscn (sec->outscn); |
| 1464 | } |
| 1465 | |
| 1466 | /* We added some sections, so we need a new shstrtab. */ |
| 1467 | Elf_Data *strtab_data = new_shstrtab (unstripped, unstripped_shnum, |
| 1468 | shstrtab, unstripped_shstrndx, |
| 1469 | sections, stripped_shnum, |
| 1470 | strtab); |
| 1471 | |
| 1472 | /* Get the updated section count. */ |
| 1473 | ELF_CHECK (elf_getshdrnum (unstripped, &unstripped_shnum) == 0, |
| 1474 | _("cannot get section count: %s")); |
| 1475 | |
| 1476 | bool placed[unstripped_shnum - 1]; |
| 1477 | memset (placed, 0, sizeof placed); |
| 1478 | |
| 1479 | /* Now update the output sections and copy in their data. */ |
| 1480 | GElf_Off offset = 0; |
| 1481 | for (const struct section *sec = sections; |
| 1482 | sec < §ions[stripped_shnum - 1]; |
| 1483 | ++sec) |
| 1484 | if (sec->outscn != NULL) |
| 1485 | { |
| 1486 | GElf_Shdr shdr_mem; |
| 1487 | GElf_Shdr *shdr = gelf_getshdr (sec->outscn, &shdr_mem); |
| 1488 | ELF_CHECK (shdr != NULL, _("cannot get section header: %s")); |
| 1489 | |
| 1490 | /* In an ET_REL file under --relocate, the sh_addr of SHF_ALLOC |
| 1491 | sections will have been set nonzero by relocation. This |
| 1492 | touched the shdrs of whichever file had the symtab. sh_addr |
| 1493 | is still zero in the corresponding shdr. The relocated |
| 1494 | address is what we want to use. */ |
| 1495 | if (stripped_ehdr->e_type != ET_REL |
| 1496 | || !(shdr_mem.sh_flags & SHF_ALLOC) |
| 1497 | || shdr_mem.sh_addr == 0) |
| 1498 | shdr_mem.sh_addr = sec->shdr.sh_addr; |
| 1499 | |
| 1500 | shdr_mem.sh_type = sec->shdr.sh_type; |
| 1501 | shdr_mem.sh_size = sec->shdr.sh_size; |
| 1502 | shdr_mem.sh_info = sec->shdr.sh_info; |
| 1503 | shdr_mem.sh_link = sec->shdr.sh_link; |
| 1504 | if (sec->shdr.sh_link != SHN_UNDEF) |
| 1505 | shdr_mem.sh_link = ndx_section[sec->shdr.sh_link - 1]; |
| 1506 | if (shdr_mem.sh_flags & SHF_INFO_LINK) |
| 1507 | shdr_mem.sh_info = ndx_section[sec->shdr.sh_info - 1]; |
| 1508 | |
| 1509 | if (strtab != NULL) |
| 1510 | shdr_mem.sh_name = ebl_strtaboffset (sec->strent); |
| 1511 | |
| 1512 | Elf_Data *indata = elf_getdata (sec->scn, NULL); |
| 1513 | ELF_CHECK (indata != NULL, _("cannot get section data: %s")); |
| 1514 | Elf_Data *outdata = elf_getdata (sec->outscn, NULL); |
| 1515 | ELF_CHECK (outdata != NULL, _("cannot copy section data: %s")); |
| 1516 | *outdata = *indata; |
| 1517 | elf_flagdata (outdata, ELF_C_SET, ELF_F_DIRTY); |
| 1518 | |
| 1519 | /* Preserve the file layout of the allocated sections. */ |
| 1520 | if (stripped_ehdr->e_type != ET_REL && (shdr_mem.sh_flags & SHF_ALLOC)) |
| 1521 | { |
| 1522 | shdr_mem.sh_offset = sec->shdr.sh_offset; |
| 1523 | placed[elf_ndxscn (sec->outscn) - 1] = true; |
| 1524 | |
| 1525 | const GElf_Off end_offset = (shdr_mem.sh_offset |
| 1526 | + (shdr_mem.sh_type == SHT_NOBITS |
| 1527 | ? 0 : shdr_mem.sh_size)); |
| 1528 | if (end_offset > offset) |
| 1529 | offset = end_offset; |
| 1530 | } |
| 1531 | |
| 1532 | update_shdr (sec->outscn, &shdr_mem); |
| 1533 | |
| 1534 | if (shdr_mem.sh_type == SHT_SYMTAB || shdr_mem.sh_type == SHT_DYNSYM) |
| 1535 | { |
| 1536 | /* We must adjust all the section indices in the symbol table. */ |
| 1537 | |
| 1538 | Elf_Data *shndxdata = NULL; /* XXX */ |
| 1539 | |
| 1540 | for (size_t i = 1; i < shdr_mem.sh_size / shdr_mem.sh_entsize; ++i) |
| 1541 | { |
| 1542 | GElf_Sym sym_mem; |
| 1543 | GElf_Word shndx = SHN_UNDEF; |
| 1544 | GElf_Sym *sym = gelf_getsymshndx (outdata, shndxdata, |
| 1545 | i, &sym_mem, &shndx); |
| 1546 | ELF_CHECK (sym != NULL, |
| 1547 | _("cannot get symbol table entry: %s")); |
| 1548 | if (sym->st_shndx != SHN_XINDEX) |
| 1549 | shndx = sym->st_shndx; |
| 1550 | |
| 1551 | if (shndx != SHN_UNDEF && shndx < SHN_LORESERVE) |
| 1552 | { |
| 1553 | if (shndx >= stripped_shnum) |
| 1554 | error (EXIT_FAILURE, 0, |
| 1555 | _("symbol [%Zu] has invalid section index"), i); |
| 1556 | |
| 1557 | shndx = ndx_section[shndx - 1]; |
| 1558 | if (shndx < SHN_LORESERVE) |
| 1559 | { |
| 1560 | sym->st_shndx = shndx; |
| 1561 | shndx = SHN_UNDEF; |
| 1562 | } |
| 1563 | else |
| 1564 | sym->st_shndx = SHN_XINDEX; |
| 1565 | |
| 1566 | ELF_CHECK (gelf_update_symshndx (outdata, shndxdata, |
| 1567 | i, sym, shndx), |
| 1568 | _("cannot update symbol table: %s")); |
| 1569 | } |
| 1570 | } |
| 1571 | |
| 1572 | if (shdr_mem.sh_type == SHT_SYMTAB) |
| 1573 | stripped_symtab = sec; |
| 1574 | if (shdr_mem.sh_type == SHT_DYNSYM) |
| 1575 | stripped_dynsym = sec; |
| 1576 | } |
| 1577 | } |
| 1578 | |
| 1579 | /* We may need to update the symbol table. */ |
| 1580 | Elf_Data *symdata = NULL; |
| 1581 | struct Ebl_Strtab *symstrtab = NULL; |
| 1582 | Elf_Data *symstrdata = NULL; |
| 1583 | if (unstripped_symtab != NULL && (stripped_symtab != NULL |
| 1584 | || check_prelink /* Section adjustments. */ |
| 1585 | || (stripped_ehdr->e_type != ET_REL |
| 1586 | && bias != 0))) |
| 1587 | { |
| 1588 | /* Merge the stripped file's symbol table into the unstripped one. */ |
| 1589 | const size_t stripped_nsym = (stripped_symtab == NULL ? 1 |
| 1590 | : (stripped_symtab->shdr.sh_size |
| 1591 | / stripped_symtab->shdr.sh_entsize)); |
| 1592 | |
| 1593 | GElf_Shdr shdr_mem; |
| 1594 | GElf_Shdr *shdr = gelf_getshdr (unstripped_symtab, &shdr_mem); |
| 1595 | ELF_CHECK (shdr != NULL, _("cannot get section header: %s")); |
| 1596 | const size_t unstripped_nsym = shdr->sh_size / shdr->sh_entsize; |
| 1597 | |
| 1598 | /* First collect all the symbols from both tables. */ |
| 1599 | |
| 1600 | const size_t total_syms = stripped_nsym - 1 + unstripped_nsym - 1; |
| 1601 | struct symbol symbols[total_syms]; |
| 1602 | size_t symndx_map[total_syms]; |
| 1603 | |
| 1604 | if (stripped_symtab != NULL) |
| 1605 | collect_symbols (unstripped, stripped_ehdr->e_type == ET_REL, |
| 1606 | stripped_symtab->scn, |
| 1607 | elf_getscn (stripped, stripped_symtab->shdr.sh_link), |
| 1608 | stripped_nsym, 0, ndx_section, |
| 1609 | symbols, symndx_map, NULL); |
| 1610 | |
| 1611 | Elf_Scn *unstripped_strtab = elf_getscn (unstripped, shdr->sh_link); |
| 1612 | collect_symbols (unstripped, stripped_ehdr->e_type == ET_REL, |
| 1613 | unstripped_symtab, unstripped_strtab, unstripped_nsym, |
| 1614 | stripped_ehdr->e_type == ET_REL ? 0 : bias, NULL, |
| 1615 | &symbols[stripped_nsym - 1], |
| 1616 | &symndx_map[stripped_nsym - 1], split_bss); |
| 1617 | |
| 1618 | /* Next, sort our array of all symbols. */ |
| 1619 | qsort (symbols, total_syms, sizeof symbols[0], compare_symbols); |
| 1620 | |
| 1621 | /* Now we can weed out the duplicates. Assign remaining symbols |
| 1622 | new slots, collecting a map from old indices to new. */ |
| 1623 | size_t nsym = 0; |
| 1624 | for (struct symbol *s = symbols; s < &symbols[total_syms]; ++s) |
| 1625 | { |
| 1626 | /* Skip a section symbol for a removed section. */ |
| 1627 | if (s->shndx == SHN_UNDEF |
| 1628 | && GELF_ST_TYPE (s->info.info) == STT_SECTION) |
| 1629 | { |
| 1630 | s->name = NULL; /* Mark as discarded. */ |
| 1631 | *s->map = STN_UNDEF; |
| 1632 | s->duplicate = NULL; |
| 1633 | continue; |
| 1634 | } |
| 1635 | |
| 1636 | struct symbol *n = s; |
| 1637 | while (n + 1 < &symbols[total_syms] && !compare_symbols (s, n + 1)) |
| 1638 | ++n; |
| 1639 | |
| 1640 | while (s < n) |
| 1641 | { |
| 1642 | /* This is a duplicate. Its twin will get the next slot. */ |
| 1643 | s->name = NULL; /* Mark as discarded. */ |
| 1644 | s->duplicate = n->map; |
| 1645 | ++s; |
| 1646 | } |
| 1647 | |
| 1648 | /* Allocate the next slot. */ |
| 1649 | *s->map = ++nsym; |
| 1650 | } |
| 1651 | |
| 1652 | /* Now we sort again, to determine the order in the output. */ |
| 1653 | qsort (symbols, total_syms, sizeof symbols[0], compare_symbols_output); |
| 1654 | |
| 1655 | if (nsym < total_syms) |
| 1656 | /* The discarded symbols are now at the end of the table. */ |
| 1657 | assert (symbols[nsym].name == NULL); |
| 1658 | |
| 1659 | /* Now a final pass updates the map with the final order, |
| 1660 | and builds up the new string table. */ |
| 1661 | symstrtab = ebl_strtabinit (true); |
| 1662 | for (size_t i = 0; i < nsym; ++i) |
| 1663 | { |
| 1664 | assert (symbols[i].name != NULL); |
| 1665 | assert (*symbols[i].map != 0); |
| 1666 | *symbols[i].map = 1 + i; |
| 1667 | symbols[i].strent = ebl_strtabadd (symstrtab, symbols[i].name, 0); |
| 1668 | } |
| 1669 | |
| 1670 | /* Scan the discarded symbols too, just to update their slots |
| 1671 | in SYMNDX_MAP to refer to their live duplicates. */ |
| 1672 | for (size_t i = nsym; i < total_syms; ++i) |
| 1673 | { |
| 1674 | assert (symbols[i].name == NULL); |
| 1675 | if (symbols[i].duplicate == NULL) |
| 1676 | assert (*symbols[i].map == STN_UNDEF); |
| 1677 | else |
| 1678 | { |
| 1679 | assert (*symbols[i].duplicate != STN_UNDEF); |
| 1680 | *symbols[i].map = *symbols[i].duplicate; |
| 1681 | } |
| 1682 | } |
| 1683 | |
| 1684 | /* Now we are ready to write the new symbol table. */ |
| 1685 | symdata = elf_getdata (unstripped_symtab, NULL); |
| 1686 | symstrdata = elf_getdata (unstripped_strtab, NULL); |
| 1687 | Elf_Data *shndxdata = NULL; /* XXX */ |
| 1688 | |
| 1689 | ebl_strtabfinalize (symstrtab, symstrdata); |
| 1690 | elf_flagdata (symstrdata, ELF_C_SET, ELF_F_DIRTY); |
| 1691 | |
| 1692 | shdr->sh_size = symdata->d_size = (1 + nsym) * shdr->sh_entsize; |
| 1693 | symdata->d_buf = xmalloc (symdata->d_size); |
| 1694 | |
| 1695 | GElf_Sym sym; |
| 1696 | memset (&sym, 0, sizeof sym); |
| 1697 | ELF_CHECK (gelf_update_symshndx (symdata, shndxdata, 0, &sym, SHN_UNDEF), |
| 1698 | _("cannot update symbol table: %s")); |
| 1699 | |
| 1700 | shdr->sh_info = 1; |
| 1701 | for (size_t i = 0; i < nsym; ++i) |
| 1702 | { |
| 1703 | struct symbol *s = &symbols[i]; |
| 1704 | |
| 1705 | /* Fill in the symbol details. */ |
| 1706 | sym.st_name = ebl_strtaboffset (s->strent); |
| 1707 | sym.st_value = s->value; /* Already biased to output address. */ |
| 1708 | sym.st_size = s->size; |
| 1709 | sym.st_shndx = s->shndx; /* Already mapped to output index. */ |
| 1710 | sym.st_info = s->info.info; |
| 1711 | sym.st_other = s->info.other; |
| 1712 | |
| 1713 | /* Keep track of the number of leading local symbols. */ |
| 1714 | if (GELF_ST_BIND (sym.st_info) == STB_LOCAL) |
| 1715 | { |
| 1716 | assert (shdr->sh_info == 1 + i); |
| 1717 | shdr->sh_info = 1 + i + 1; |
| 1718 | } |
| 1719 | |
| 1720 | ELF_CHECK (gelf_update_symshndx (symdata, shndxdata, 1 + i, |
| 1721 | &sym, SHN_UNDEF), |
| 1722 | _("cannot update symbol table: %s")); |
| 1723 | |
| 1724 | } |
| 1725 | elf_flagdata (symdata, ELF_C_SET, ELF_F_DIRTY); |
| 1726 | update_shdr (unstripped_symtab, shdr); |
| 1727 | |
| 1728 | if (stripped_symtab != NULL) |
| 1729 | { |
| 1730 | /* Adjust any relocations referring to the old symbol table. */ |
| 1731 | const size_t old_sh_link = elf_ndxscn (stripped_symtab->scn); |
| 1732 | for (const struct section *sec = sections; |
| 1733 | sec < §ions[stripped_shnum - 1]; |
| 1734 | ++sec) |
| 1735 | if (sec->outscn != NULL && sec->shdr.sh_link == old_sh_link) |
| 1736 | adjust_relocs (sec->outscn, sec->scn, &sec->shdr, |
| 1737 | symndx_map, shdr); |
| 1738 | } |
| 1739 | |
| 1740 | /* Also adjust references to the other old symbol table. */ |
| 1741 | adjust_all_relocs (unstripped, unstripped_symtab, shdr, |
| 1742 | &symndx_map[stripped_nsym - 1]); |
| 1743 | } |
| 1744 | else if (stripped_symtab != NULL && stripped_shnum != unstripped_shnum) |
| 1745 | check_symtab_section_symbols (unstripped, |
| 1746 | stripped_ehdr->e_type == ET_REL, |
| 1747 | stripped_symtab->scn, |
| 1748 | unstripped_shnum, unstripped_shstrndx, |
| 1749 | stripped_symtab->outscn, |
| 1750 | stripped_shnum, stripped_shstrndx, |
| 1751 | debuglink); |
| 1752 | |
| 1753 | if (stripped_dynsym != NULL) |
| 1754 | (void) check_symtab_section_symbols (unstripped, |
| 1755 | stripped_ehdr->e_type == ET_REL, |
| 1756 | stripped_dynsym->outscn, |
| 1757 | unstripped_shnum, |
| 1758 | unstripped_shstrndx, |
| 1759 | stripped_dynsym->scn, stripped_shnum, |
| 1760 | stripped_shstrndx, debuglink); |
| 1761 | |
| 1762 | /* We need to preserve the layout of the stripped file so the |
| 1763 | phdrs will match up. This requires us to do our own layout of |
| 1764 | the added sections. We do manual layout even for ET_REL just |
| 1765 | so we can try to match what the original probably had. */ |
| 1766 | |
| 1767 | elf_flagelf (unstripped, ELF_C_SET, ELF_F_LAYOUT); |
| 1768 | |
| 1769 | if (offset == 0) |
| 1770 | /* For ET_REL we are starting the layout from scratch. */ |
| 1771 | offset = gelf_fsize (unstripped, ELF_T_EHDR, 1, EV_CURRENT); |
| 1772 | |
| 1773 | bool skip_reloc = false; |
| 1774 | do |
| 1775 | { |
| 1776 | skip_reloc = !skip_reloc; |
| 1777 | for (size_t i = 0; i < unstripped_shnum - 1; ++i) |
| 1778 | if (!placed[i]) |
| 1779 | { |
| 1780 | scn = elf_getscn (unstripped, 1 + i); |
| 1781 | |
| 1782 | GElf_Shdr shdr_mem; |
| 1783 | GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); |
| 1784 | ELF_CHECK (shdr != NULL, _("cannot get section header: %s")); |
| 1785 | |
| 1786 | /* We must make sure we have read in the data of all sections |
| 1787 | beforehand and marked them to be written out. When we're |
| 1788 | modifying the existing file in place, we might overwrite |
| 1789 | this part of the file before we get to handling the section. */ |
| 1790 | |
| 1791 | ELF_CHECK (elf_flagdata (elf_getdata (scn, NULL), |
| 1792 | ELF_C_SET, ELF_F_DIRTY), |
| 1793 | _("cannot read section data: %s")); |
| 1794 | |
| 1795 | if (skip_reloc |
| 1796 | && (shdr->sh_type == SHT_REL || shdr->sh_type == SHT_RELA)) |
| 1797 | continue; |
| 1798 | |
| 1799 | GElf_Off align = shdr->sh_addralign ?: 1; |
| 1800 | offset = (offset + align - 1) & -align; |
| 1801 | shdr->sh_offset = offset; |
| 1802 | if (shdr->sh_type != SHT_NOBITS) |
| 1803 | offset += shdr->sh_size; |
| 1804 | |
| 1805 | update_shdr (scn, shdr); |
| 1806 | |
| 1807 | if (unstripped_shstrndx == 1 + i) |
| 1808 | { |
| 1809 | /* Place the section headers immediately after |
| 1810 | .shstrtab, and update the ELF header. */ |
| 1811 | |
| 1812 | GElf_Ehdr ehdr_mem; |
| 1813 | GElf_Ehdr *ehdr = gelf_getehdr (unstripped, &ehdr_mem); |
| 1814 | ELF_CHECK (ehdr != NULL, _("cannot get ELF header: %s")); |
| 1815 | |
| 1816 | GElf_Off sh_align = gelf_getclass (unstripped) * 4; |
| 1817 | offset = (offset + sh_align - 1) & -sh_align; |
| 1818 | ehdr->e_shnum = unstripped_shnum; |
| 1819 | ehdr->e_shoff = offset; |
| 1820 | offset += unstripped_shnum * ehdr->e_shentsize; |
| 1821 | ELF_CHECK (gelf_update_ehdr (unstripped, ehdr), |
| 1822 | _("cannot update ELF header: %s")); |
| 1823 | } |
| 1824 | |
| 1825 | placed[i] = true; |
| 1826 | } |
| 1827 | } |
| 1828 | while (skip_reloc); |
| 1829 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1830 | size_t phnum; |
| 1831 | ELF_CHECK (elf_getphdrnum (stripped, &phnum) == 0, |
| 1832 | _("cannot get number of program headers: %s")); |
| 1833 | |
| 1834 | if (phnum > 0) |
| 1835 | ELF_CHECK (gelf_newphdr (unstripped, phnum), |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1836 | _("cannot create program headers: %s")); |
| 1837 | |
| 1838 | /* Copy each program header from the stripped file. */ |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1839 | for (size_t i = 0; i < phnum; ++i) |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1840 | { |
| 1841 | GElf_Phdr phdr_mem; |
| 1842 | GElf_Phdr *phdr = gelf_getphdr (stripped, i, &phdr_mem); |
| 1843 | ELF_CHECK (phdr != NULL, _("cannot get program header: %s")); |
| 1844 | |
| 1845 | ELF_CHECK (gelf_update_phdr (unstripped, i, phdr), |
| 1846 | _("cannot update program header: %s")); |
| 1847 | } |
| 1848 | |
| 1849 | /* Finally, write out the file. */ |
| 1850 | ELF_CHECK (elf_update (unstripped, ELF_C_WRITE) > 0, |
| 1851 | _("cannot write output file: %s")); |
| 1852 | |
| 1853 | if (strtab != NULL) |
| 1854 | { |
| 1855 | ebl_strtabfree (strtab); |
| 1856 | free (strtab_data->d_buf); |
| 1857 | } |
| 1858 | |
| 1859 | if (symdata != NULL) |
| 1860 | free (symdata->d_buf); |
| 1861 | if (symstrtab != NULL) |
| 1862 | { |
| 1863 | ebl_strtabfree (symstrtab); |
| 1864 | free (symstrdata->d_buf); |
| 1865 | } |
| 1866 | } |
| 1867 | |
| 1868 | /* Process one pair of files, already opened. */ |
| 1869 | static void |
| 1870 | handle_file (const char *output_file, bool create_dirs, |
| 1871 | Elf *stripped, const GElf_Ehdr *stripped_ehdr, |
| 1872 | Elf *unstripped) |
| 1873 | { |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1874 | size_t phnum; |
| 1875 | ELF_CHECK (elf_getphdrnum (stripped, &phnum) == 0, |
| 1876 | _("cannot get number of program headers: %s")); |
| 1877 | |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1878 | /* Determine the address bias between the debuginfo file and the main |
| 1879 | file, which may have been modified by prelinking. */ |
| 1880 | GElf_Addr bias = 0; |
| 1881 | if (unstripped != NULL) |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1882 | for (size_t i = 0; i < phnum; ++i) |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1883 | { |
| 1884 | GElf_Phdr phdr_mem; |
| 1885 | GElf_Phdr *phdr = gelf_getphdr (stripped, i, &phdr_mem); |
| 1886 | ELF_CHECK (phdr != NULL, _("cannot get program header: %s")); |
| 1887 | if (phdr->p_type == PT_LOAD) |
| 1888 | { |
| 1889 | GElf_Phdr unstripped_phdr_mem; |
| 1890 | GElf_Phdr *unstripped_phdr = gelf_getphdr (unstripped, i, |
| 1891 | &unstripped_phdr_mem); |
| 1892 | ELF_CHECK (unstripped_phdr != NULL, |
| 1893 | _("cannot get program header: %s")); |
| 1894 | bias = phdr->p_vaddr - unstripped_phdr->p_vaddr; |
| 1895 | break; |
| 1896 | } |
| 1897 | } |
| 1898 | |
| 1899 | /* One day we could adjust all the DWARF data (like prelink itself does). */ |
| 1900 | if (bias != 0) |
| 1901 | { |
| 1902 | if (output_file == NULL) |
| 1903 | error (0, 0, _("\ |
| 1904 | DWARF data not adjusted for prelinking bias; consider prelink -u")); |
| 1905 | else |
| 1906 | error (0, 0, _("\ |
| 1907 | DWARF data in '%s' not adjusted for prelinking bias; consider prelink -u"), |
| 1908 | output_file); |
| 1909 | } |
| 1910 | |
| 1911 | if (output_file == NULL) |
| 1912 | /* Modify the unstripped file in place. */ |
| 1913 | copy_elided_sections (unstripped, stripped, stripped_ehdr, bias); |
| 1914 | else |
| 1915 | { |
| 1916 | if (create_dirs) |
| 1917 | make_directories (output_file); |
| 1918 | |
| 1919 | /* Copy the unstripped file and then modify it. */ |
| 1920 | int outfd = open64 (output_file, O_RDWR | O_CREAT, |
| 1921 | stripped_ehdr->e_type == ET_REL ? 0666 : 0777); |
| 1922 | if (outfd < 0) |
| 1923 | error (EXIT_FAILURE, errno, _("cannot open '%s'"), output_file); |
| 1924 | Elf *outelf = elf_begin (outfd, ELF_C_WRITE, NULL); |
| 1925 | ELF_CHECK (outelf != NULL, _("cannot create ELF descriptor: %s")); |
| 1926 | |
| 1927 | if (unstripped == NULL) |
| 1928 | { |
| 1929 | /* Actually, we are just copying out the main file as it is. */ |
| 1930 | copy_elf (outelf, stripped); |
| 1931 | if (stripped_ehdr->e_type != ET_REL) |
| 1932 | elf_flagelf (outelf, ELF_C_SET, ELF_F_LAYOUT); |
| 1933 | ELF_CHECK (elf_update (outelf, ELF_C_WRITE) > 0, |
| 1934 | _("cannot write output file: %s")); |
| 1935 | } |
| 1936 | else |
| 1937 | { |
| 1938 | copy_elf (outelf, unstripped); |
| 1939 | copy_elided_sections (outelf, stripped, stripped_ehdr, bias); |
| 1940 | } |
| 1941 | |
| 1942 | elf_end (outelf); |
| 1943 | close (outfd); |
| 1944 | } |
| 1945 | } |
| 1946 | |
| 1947 | static int |
| 1948 | open_file (const char *file, bool writable) |
| 1949 | { |
| 1950 | int fd = open64 (file, writable ? O_RDWR : O_RDONLY); |
| 1951 | if (fd < 0) |
| 1952 | error (EXIT_FAILURE, errno, _("cannot open '%s'"), file); |
| 1953 | return fd; |
| 1954 | } |
| 1955 | |
| 1956 | /* Handle a pair of files we need to open by name. */ |
| 1957 | static void |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1958 | handle_explicit_files (const char *output_file, bool create_dirs, bool force, |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1959 | const char *stripped_file, const char *unstripped_file) |
| 1960 | { |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1961 | |
| 1962 | /* Warn, and exit if not forced to continue, if some ELF header |
| 1963 | sanity check for the stripped and unstripped files failed. */ |
| 1964 | void warn (const char *msg) |
| 1965 | { |
| 1966 | error (force ? 0 : EXIT_FAILURE, 0, "%s'%s' and '%s' %s%s.", |
| 1967 | force ? _("WARNING: ") : "", |
| 1968 | stripped_file, unstripped_file, msg, |
| 1969 | force ? "" : _(", use --force")); |
| 1970 | } |
| 1971 | |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1972 | int stripped_fd = open_file (stripped_file, false); |
| 1973 | Elf *stripped = elf_begin (stripped_fd, ELF_C_READ, NULL); |
| 1974 | GElf_Ehdr stripped_ehdr; |
| 1975 | ELF_CHECK (gelf_getehdr (stripped, &stripped_ehdr), |
| 1976 | _("cannot create ELF descriptor: %s")); |
| 1977 | |
| 1978 | int unstripped_fd = -1; |
| 1979 | Elf *unstripped = NULL; |
| 1980 | if (unstripped_file != NULL) |
| 1981 | { |
| 1982 | unstripped_fd = open_file (unstripped_file, output_file == NULL); |
| 1983 | unstripped = elf_begin (unstripped_fd, |
| 1984 | (output_file == NULL ? ELF_C_RDWR : ELF_C_READ), |
| 1985 | NULL); |
| 1986 | GElf_Ehdr unstripped_ehdr; |
| 1987 | ELF_CHECK (gelf_getehdr (unstripped, &unstripped_ehdr), |
| 1988 | _("cannot create ELF descriptor: %s")); |
| 1989 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1990 | if (memcmp (stripped_ehdr.e_ident, |
| 1991 | unstripped_ehdr.e_ident, EI_NIDENT) != 0) |
| 1992 | warn (_("ELF header identification (e_ident) different")); |
| 1993 | |
| 1994 | if (stripped_ehdr.e_type != unstripped_ehdr.e_type) |
| 1995 | warn (_("ELF header type (e_type) different")); |
| 1996 | |
| 1997 | if (stripped_ehdr.e_machine != unstripped_ehdr.e_machine) |
| 1998 | warn (_("ELF header machine type (e_machine) different")); |
| 1999 | |
| 2000 | if (stripped_ehdr.e_phnum < unstripped_ehdr.e_phnum) |
| 2001 | warn (_("stripped program header (e_phnum) smaller than unstripped")); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 2002 | } |
| 2003 | |
| 2004 | handle_file (output_file, create_dirs, stripped, &stripped_ehdr, unstripped); |
| 2005 | |
| 2006 | elf_end (stripped); |
| 2007 | close (stripped_fd); |
| 2008 | |
| 2009 | elf_end (unstripped); |
| 2010 | close (unstripped_fd); |
| 2011 | } |
| 2012 | |
| 2013 | |
| 2014 | /* Handle a pair of files opened implicitly by libdwfl for one module. */ |
| 2015 | static void |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 2016 | handle_dwfl_module (const char *output_file, bool create_dirs, bool force, |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 2017 | Dwfl_Module *mod, bool all, bool ignore, bool relocate) |
| 2018 | { |
| 2019 | GElf_Addr bias; |
| 2020 | Elf *stripped = dwfl_module_getelf (mod, &bias); |
| 2021 | if (stripped == NULL) |
| 2022 | { |
| 2023 | if (ignore) |
| 2024 | return; |
| 2025 | |
| 2026 | const char *file; |
| 2027 | const char *modname = dwfl_module_info (mod, NULL, NULL, NULL, |
| 2028 | NULL, NULL, &file, NULL); |
| 2029 | if (file == NULL) |
| 2030 | error (EXIT_FAILURE, 0, |
| 2031 | _("cannot find stripped file for module '%s': %s"), |
| 2032 | modname, dwfl_errmsg (-1)); |
| 2033 | else |
| 2034 | error (EXIT_FAILURE, 0, |
| 2035 | _("cannot open stripped file '%s' for module '%s': %s"), |
| 2036 | modname, file, dwfl_errmsg (-1)); |
| 2037 | } |
| 2038 | |
| 2039 | Elf *debug = dwarf_getelf (dwfl_module_getdwarf (mod, &bias)); |
| 2040 | if (debug == NULL && !all) |
| 2041 | { |
| 2042 | if (ignore) |
| 2043 | return; |
| 2044 | |
| 2045 | const char *file; |
| 2046 | const char *modname = dwfl_module_info (mod, NULL, NULL, NULL, |
| 2047 | NULL, NULL, NULL, &file); |
| 2048 | if (file == NULL) |
| 2049 | error (EXIT_FAILURE, 0, |
| 2050 | _("cannot find debug file for module '%s': %s"), |
| 2051 | modname, dwfl_errmsg (-1)); |
| 2052 | else |
| 2053 | error (EXIT_FAILURE, 0, |
| 2054 | _("cannot open debug file '%s' for module '%s': %s"), |
| 2055 | modname, file, dwfl_errmsg (-1)); |
| 2056 | } |
| 2057 | |
| 2058 | if (debug == stripped) |
| 2059 | { |
| 2060 | if (all) |
| 2061 | debug = NULL; |
| 2062 | else |
| 2063 | { |
| 2064 | const char *file; |
| 2065 | const char *modname = dwfl_module_info (mod, NULL, NULL, NULL, |
| 2066 | NULL, NULL, &file, NULL); |
| 2067 | error (EXIT_FAILURE, 0, _("module '%s' file '%s' is not stripped"), |
| 2068 | modname, file); |
| 2069 | } |
| 2070 | } |
| 2071 | |
| 2072 | GElf_Ehdr stripped_ehdr; |
| 2073 | ELF_CHECK (gelf_getehdr (stripped, &stripped_ehdr), |
| 2074 | _("cannot create ELF descriptor: %s")); |
| 2075 | |
| 2076 | if (stripped_ehdr.e_type == ET_REL) |
| 2077 | { |
| 2078 | if (!relocate) |
| 2079 | { |
| 2080 | /* We can't use the Elf handles already open, |
| 2081 | because the DWARF sections have been relocated. */ |
| 2082 | |
| 2083 | const char *stripped_file = NULL; |
| 2084 | const char *unstripped_file = NULL; |
| 2085 | (void) dwfl_module_info (mod, NULL, NULL, NULL, NULL, NULL, |
| 2086 | &stripped_file, &unstripped_file); |
| 2087 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 2088 | handle_explicit_files (output_file, create_dirs, force, |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 2089 | stripped_file, unstripped_file); |
| 2090 | return; |
| 2091 | } |
| 2092 | |
| 2093 | /* Relocation is what we want! This ensures that all sections that can |
| 2094 | get sh_addr values assigned have them, even ones not used in DWARF. |
| 2095 | They might still be used in the symbol table. */ |
| 2096 | if (dwfl_module_relocations (mod) < 0) |
| 2097 | error (EXIT_FAILURE, 0, |
| 2098 | _("cannot cache section addresses for module '%s': %s"), |
| 2099 | dwfl_module_info (mod, NULL, NULL, NULL, NULL, NULL, NULL, NULL), |
| 2100 | dwfl_errmsg (-1)); |
| 2101 | } |
| 2102 | |
| 2103 | handle_file (output_file, create_dirs, stripped, &stripped_ehdr, debug); |
| 2104 | } |
| 2105 | |
| 2106 | /* Handle one module being written to the output directory. */ |
| 2107 | static void |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 2108 | handle_output_dir_module (const char *output_dir, Dwfl_Module *mod, bool force, |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 2109 | bool all, bool ignore, bool modnames, bool relocate) |
| 2110 | { |
| 2111 | if (! modnames) |
| 2112 | { |
| 2113 | /* Make sure we've searched for the ELF file. */ |
| 2114 | GElf_Addr bias; |
| 2115 | (void) dwfl_module_getelf (mod, &bias); |
| 2116 | } |
| 2117 | |
| 2118 | const char *file; |
| 2119 | const char *name = dwfl_module_info (mod, NULL, NULL, NULL, |
| 2120 | NULL, NULL, &file, NULL); |
| 2121 | |
| 2122 | if (file == NULL && ignore) |
| 2123 | return; |
| 2124 | |
| 2125 | char *output_file; |
| 2126 | if (asprintf (&output_file, "%s/%s", output_dir, modnames ? name : file) < 0) |
| 2127 | error (EXIT_FAILURE, 0, _("memory exhausted")); |
| 2128 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 2129 | handle_dwfl_module (output_file, true, force, mod, all, ignore, relocate); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 2130 | } |
| 2131 | |
| 2132 | |
| 2133 | static void |
| 2134 | list_module (Dwfl_Module *mod) |
| 2135 | { |
| 2136 | /* Make sure we have searched for the files. */ |
| 2137 | GElf_Addr bias; |
| 2138 | bool have_elf = dwfl_module_getelf (mod, &bias) != NULL; |
| 2139 | bool have_dwarf = dwfl_module_getdwarf (mod, &bias) != NULL; |
| 2140 | |
| 2141 | const char *file; |
| 2142 | const char *debug; |
| 2143 | Dwarf_Addr start; |
| 2144 | Dwarf_Addr end; |
| 2145 | const char *name = dwfl_module_info (mod, NULL, &start, &end, |
| 2146 | NULL, NULL, &file, &debug); |
| 2147 | if (file != NULL && debug != NULL && (debug == file || !strcmp (debug, file))) |
| 2148 | debug = "."; |
| 2149 | |
| 2150 | const unsigned char *id; |
| 2151 | GElf_Addr id_vaddr; |
| 2152 | int id_len = dwfl_module_build_id (mod, &id, &id_vaddr); |
| 2153 | |
| 2154 | printf ("%#" PRIx64 "+%#" PRIx64 " ", start, end - start); |
| 2155 | |
| 2156 | if (id_len > 0) |
| 2157 | { |
| 2158 | do |
| 2159 | printf ("%02" PRIx8, *id++); |
| 2160 | while (--id_len > 0); |
| 2161 | if (id_vaddr != 0) |
| 2162 | printf ("@%#" PRIx64, id_vaddr); |
| 2163 | } |
| 2164 | else |
| 2165 | putchar ('-'); |
| 2166 | |
| 2167 | printf (" %s %s %s\n", |
| 2168 | file ?: have_elf ? "." : "-", |
| 2169 | debug ?: have_dwarf ? "." : "-", |
| 2170 | name); |
| 2171 | } |
| 2172 | |
| 2173 | |
| 2174 | struct match_module_info |
| 2175 | { |
| 2176 | char **patterns; |
| 2177 | Dwfl_Module *found; |
| 2178 | bool match_files; |
| 2179 | }; |
| 2180 | |
| 2181 | static int |
| 2182 | match_module (Dwfl_Module *mod, |
| 2183 | void **userdata __attribute__ ((unused)), |
| 2184 | const char *name, |
| 2185 | Dwarf_Addr start __attribute__ ((unused)), |
| 2186 | void *arg) |
| 2187 | { |
| 2188 | struct match_module_info *info = arg; |
| 2189 | |
| 2190 | if (info->patterns[0] == NULL) /* Match all. */ |
| 2191 | { |
| 2192 | match: |
| 2193 | info->found = mod; |
| 2194 | return DWARF_CB_ABORT; |
| 2195 | } |
| 2196 | |
| 2197 | if (info->match_files) |
| 2198 | { |
| 2199 | /* Make sure we've searched for the ELF file. */ |
| 2200 | GElf_Addr bias; |
| 2201 | (void) dwfl_module_getelf (mod, &bias); |
| 2202 | |
| 2203 | const char *file; |
| 2204 | const char *check = dwfl_module_info (mod, NULL, NULL, NULL, |
| 2205 | NULL, NULL, &file, NULL); |
| 2206 | assert (check == name); |
| 2207 | if (file == NULL) |
| 2208 | return DWARF_CB_OK; |
| 2209 | |
| 2210 | name = file; |
| 2211 | } |
| 2212 | |
| 2213 | for (char **p = info->patterns; *p != NULL; ++p) |
| 2214 | if (fnmatch (*p, name, 0) == 0) |
| 2215 | goto match; |
| 2216 | |
| 2217 | return DWARF_CB_OK; |
| 2218 | } |
| 2219 | |
| 2220 | /* Handle files opened implicitly via libdwfl. */ |
| 2221 | static void |
| 2222 | handle_implicit_modules (const struct arg_info *info) |
| 2223 | { |
| 2224 | struct match_module_info mmi = { info->args, NULL, info->match_files }; |
| 2225 | inline ptrdiff_t next (ptrdiff_t offset) |
| 2226 | { |
| 2227 | return dwfl_getmodules (info->dwfl, &match_module, &mmi, offset); |
| 2228 | } |
| 2229 | ptrdiff_t offset = next (0); |
| 2230 | if (offset == 0) |
| 2231 | error (EXIT_FAILURE, 0, _("no matching modules found")); |
| 2232 | |
| 2233 | if (info->list) |
| 2234 | do |
| 2235 | list_module (mmi.found); |
| 2236 | while ((offset = next (offset)) > 0); |
| 2237 | else if (info->output_dir == NULL) |
| 2238 | { |
| 2239 | if (next (offset) != 0) |
| 2240 | error (EXIT_FAILURE, 0, _("matched more than one module")); |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 2241 | handle_dwfl_module (info->output_file, false, info->force, mmi.found, |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 2242 | info->all, info->ignore, info->relocate); |
| 2243 | } |
| 2244 | else |
| 2245 | do |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 2246 | handle_output_dir_module (info->output_dir, mmi.found, info->force, |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 2247 | info->all, info->ignore, |
| 2248 | info->modnames, info->relocate); |
| 2249 | while ((offset = next (offset)) > 0); |
| 2250 | } |
| 2251 | |
| 2252 | int |
| 2253 | main (int argc, char **argv) |
| 2254 | { |
| 2255 | /* Make memory leak detection possible. */ |
| 2256 | mtrace (); |
| 2257 | |
| 2258 | /* We use no threads here which can interfere with handling a stream. */ |
| 2259 | __fsetlocking (stdin, FSETLOCKING_BYCALLER); |
| 2260 | __fsetlocking (stdout, FSETLOCKING_BYCALLER); |
| 2261 | __fsetlocking (stderr, FSETLOCKING_BYCALLER); |
| 2262 | |
| 2263 | /* Set locale. */ |
| 2264 | setlocale (LC_ALL, ""); |
| 2265 | |
| 2266 | /* Make sure the message catalog can be found. */ |
| 2267 | bindtextdomain (PACKAGE_TARNAME, LOCALEDIR); |
| 2268 | |
| 2269 | /* Initialize the message catalog. */ |
| 2270 | textdomain (PACKAGE_TARNAME); |
| 2271 | |
| 2272 | /* Parse and process arguments. */ |
| 2273 | const struct argp_child argp_children[] = |
| 2274 | { |
| 2275 | { |
| 2276 | .argp = dwfl_standard_argp (), |
| 2277 | .header = N_("Input selection options:"), |
| 2278 | .group = 1, |
| 2279 | }, |
| 2280 | { .argp = NULL }, |
| 2281 | }; |
| 2282 | const struct argp argp = |
| 2283 | { |
| 2284 | .options = options, |
| 2285 | .parser = parse_opt, |
| 2286 | .children = argp_children, |
| 2287 | .args_doc = N_("STRIPPED-FILE DEBUG-FILE\n[MODULE...]"), |
| 2288 | .doc = N_("\ |
| 2289 | Combine stripped files with separate symbols and debug information.\v\ |
| 2290 | The first form puts the result in DEBUG-FILE if -o was not given.\n\ |
| 2291 | \n\ |
| 2292 | MODULE arguments give file name patterns matching modules to process.\n\ |
| 2293 | With -f these match the file name of the main (stripped) file \ |
| 2294 | (slashes are never special), otherwise they match the simple module names. \ |
| 2295 | With no arguments, process all modules found.\n\ |
| 2296 | \n\ |
| 2297 | Multiple modules are written to files under OUTPUT-DIRECTORY, \ |
| 2298 | creating subdirectories as needed. \ |
| 2299 | With -m these files have simple module names, otherwise they have the \ |
| 2300 | name of the main file complete with directory underneath OUTPUT-DIRECTORY.\n\ |
| 2301 | \n\ |
| 2302 | With -n no files are written, but one line to standard output for each module:\ |
| 2303 | \n\tSTART+SIZE BUILDID FILE DEBUGFILE MODULENAME\n\ |
| 2304 | START and SIZE are hexadecimal giving the address bounds of the module. \ |
| 2305 | BUILDID is hexadecimal for the build ID bits, or - if no ID is known; \ |
| 2306 | the hexadecimal may be followed by @0xADDR giving the address where the \ |
| 2307 | ID resides if that is known. \ |
| 2308 | FILE is the file name found for the module, or - if none was found, \ |
| 2309 | or . if an ELF image is available but not from any named file. \ |
| 2310 | DEBUGFILE is the separate debuginfo file name, \ |
| 2311 | or - if no debuginfo was found, or . if FILE contains the debug information.\ |
| 2312 | ") |
| 2313 | }; |
| 2314 | |
| 2315 | int remaining; |
| 2316 | struct arg_info info = { .args = NULL }; |
| 2317 | error_t result = argp_parse (&argp, argc, argv, 0, &remaining, &info); |
| 2318 | if (result == ENOSYS) |
| 2319 | assert (info.dwfl == NULL); |
| 2320 | else if (result) |
| 2321 | return EXIT_FAILURE; |
| 2322 | assert (info.args != NULL); |
| 2323 | |
| 2324 | /* Tell the library which version we are expecting. */ |
| 2325 | elf_version (EV_CURRENT); |
| 2326 | |
| 2327 | if (info.dwfl == NULL) |
| 2328 | { |
| 2329 | assert (result == ENOSYS); |
| 2330 | |
| 2331 | if (info.output_dir != NULL) |
| 2332 | { |
| 2333 | char *file; |
| 2334 | if (asprintf (&file, "%s/%s", info.output_dir, info.args[0]) < 0) |
| 2335 | error (EXIT_FAILURE, 0, _("memory exhausted")); |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 2336 | handle_explicit_files (file, true, info.force, |
| 2337 | info.args[0], info.args[1]); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 2338 | free (file); |
| 2339 | } |
| 2340 | else |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 2341 | handle_explicit_files (info.output_file, false, info.force, |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 2342 | info.args[0], info.args[1]); |
| 2343 | } |
| 2344 | else |
| 2345 | { |
| 2346 | /* parse_opt checked this. */ |
| 2347 | assert (info.output_file != NULL || info.output_dir != NULL || info.list); |
| 2348 | |
| 2349 | handle_implicit_modules (&info); |
| 2350 | |
| 2351 | dwfl_end (info.dwfl); |
| 2352 | } |
| 2353 | |
| 2354 | return 0; |
| 2355 | } |
| 2356 | |
| 2357 | |
| 2358 | #include "debugpred.h" |