Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1 | /* Discard section not used at runtime from object files. |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 2 | Copyright (C) 2000-2012, 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 Ulrich Drepper <drepper@redhat.com>, 2000. |
| 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 | #ifdef HAVE_CONFIG_H |
| 20 | # include <config.h> |
| 21 | #endif |
| 22 | |
| 23 | #include <argp.h> |
| 24 | #include <assert.h> |
| 25 | #include <byteswap.h> |
| 26 | #include <endian.h> |
| 27 | #include <error.h> |
| 28 | #include <fcntl.h> |
| 29 | #include <gelf.h> |
| 30 | #include <libelf.h> |
| 31 | #include <libintl.h> |
| 32 | #include <locale.h> |
| 33 | #include <mcheck.h> |
| 34 | #include <stdbool.h> |
| 35 | #include <stdio.h> |
| 36 | #include <stdio_ext.h> |
| 37 | #include <stdlib.h> |
| 38 | #include <string.h> |
| 39 | #include <unistd.h> |
| 40 | #include <sys/param.h> |
| 41 | #include <sys/stat.h> |
| 42 | #include <sys/time.h> |
| 43 | |
| 44 | #include <elf-knowledge.h> |
| 45 | #include <libebl.h> |
| 46 | #include <system.h> |
| 47 | |
| 48 | typedef uint8_t GElf_Byte; |
| 49 | |
| 50 | /* Name and version of program. */ |
| 51 | static void print_version (FILE *stream, struct argp_state *state); |
| 52 | ARGP_PROGRAM_VERSION_HOOK_DEF = print_version; |
| 53 | |
| 54 | /* Bug report address. */ |
| 55 | ARGP_PROGRAM_BUG_ADDRESS_DEF = PACKAGE_BUGREPORT; |
| 56 | |
| 57 | |
| 58 | /* Values for the parameters which have no short form. */ |
| 59 | #define OPT_REMOVE_COMMENT 0x100 |
| 60 | #define OPT_PERMISSIVE 0x101 |
| 61 | #define OPT_STRIP_SECTIONS 0x102 |
| 62 | #define OPT_RELOC_DEBUG 0x103 |
| 63 | |
| 64 | |
| 65 | /* Definitions of arguments for argp functions. */ |
| 66 | static const struct argp_option options[] = |
| 67 | { |
| 68 | { NULL, 0, NULL, 0, N_("Output selection:"), 0 }, |
| 69 | { "output", 'o', "FILE", 0, N_("Place stripped output into FILE"), 0 }, |
| 70 | { NULL, 'f', "FILE", 0, N_("Extract the removed sections into FILE"), 0 }, |
| 71 | { NULL, 'F', "FILE", 0, N_("Embed name FILE instead of -f argument"), 0 }, |
| 72 | |
| 73 | { NULL, 0, NULL, 0, N_("Output options:"), 0 }, |
| 74 | { "strip-all", 's', NULL, OPTION_HIDDEN, NULL, 0 }, |
| 75 | { "strip-debug", 'g', NULL, 0, N_("Remove all debugging symbols"), 0 }, |
| 76 | { NULL, 'd', NULL, OPTION_ALIAS, NULL, 0 }, |
| 77 | { NULL, 'S', NULL, OPTION_ALIAS, NULL, 0 }, |
| 78 | { "strip-sections", OPT_STRIP_SECTIONS, NULL, 0, |
| 79 | N_("Remove section headers (not recommended)"), 0 }, |
| 80 | { "preserve-dates", 'p', NULL, 0, |
| 81 | N_("Copy modified/access timestamps to the output"), 0 }, |
| 82 | { "reloc-debug-sections", OPT_RELOC_DEBUG, NULL, 0, |
| 83 | N_("Resolve all trivial relocations between debug sections if the removed sections are placed in a debug file (only relevant for ET_REL files, operation is not reversable, needs -f)"), 0 }, |
| 84 | { "remove-comment", OPT_REMOVE_COMMENT, NULL, 0, |
| 85 | N_("Remove .comment section"), 0 }, |
| 86 | { "remove-section", 'R', "SECTION", OPTION_HIDDEN, NULL, 0 }, |
| 87 | { "permissive", OPT_PERMISSIVE, NULL, 0, |
| 88 | N_("Relax a few rules to handle slightly broken ELF files"), 0 }, |
| 89 | { NULL, 0, NULL, 0, NULL, 0 } |
| 90 | }; |
| 91 | |
| 92 | /* Short description of program. */ |
| 93 | static const char doc[] = N_("Discard symbols from object files."); |
| 94 | |
| 95 | /* Strings for arguments in help texts. */ |
| 96 | static const char args_doc[] = N_("[FILE...]"); |
| 97 | |
| 98 | /* Prototype for option handler. */ |
| 99 | static error_t parse_opt (int key, char *arg, struct argp_state *state); |
| 100 | |
| 101 | /* Data structure to communicate with argp functions. */ |
| 102 | static struct argp argp = |
| 103 | { |
| 104 | options, parse_opt, args_doc, doc, NULL, NULL, NULL |
| 105 | }; |
| 106 | |
| 107 | |
| 108 | /* Print symbols in file named FNAME. */ |
| 109 | static int process_file (const char *fname); |
| 110 | |
| 111 | /* Handle one ELF file. */ |
| 112 | static int handle_elf (int fd, Elf *elf, const char *prefix, |
| 113 | const char *fname, mode_t mode, struct timeval tvp[2]); |
| 114 | |
| 115 | /* Handle all files contained in the archive. */ |
| 116 | static int handle_ar (int fd, Elf *elf, const char *prefix, const char *fname, |
| 117 | struct timeval tvp[2]); |
| 118 | |
| 119 | #define INTERNAL_ERROR(fname) \ |
| 120 | error (EXIT_FAILURE, 0, gettext ("%s: INTERNAL ERROR %d (%s-%s): %s"), \ |
| 121 | fname, __LINE__, PACKAGE_VERSION, __DATE__, elf_errmsg (-1)) |
| 122 | |
| 123 | |
| 124 | /* Name of the output file. */ |
| 125 | static const char *output_fname; |
| 126 | |
| 127 | /* Name of the debug output file. */ |
| 128 | static const char *debug_fname; |
| 129 | |
| 130 | /* Name to pretend the debug output file has. */ |
| 131 | static const char *debug_fname_embed; |
| 132 | |
| 133 | /* If true output files shall have same date as the input file. */ |
| 134 | static bool preserve_dates; |
| 135 | |
| 136 | /* If true .comment sections will be removed. */ |
| 137 | static bool remove_comment; |
| 138 | |
| 139 | /* If true remove all debug sections. */ |
| 140 | static bool remove_debug; |
| 141 | |
| 142 | /* If true remove all section headers. */ |
| 143 | static bool remove_shdrs; |
| 144 | |
| 145 | /* If true relax some ELF rules for input files. */ |
| 146 | static bool permissive; |
| 147 | |
| 148 | /* If true perform relocations between debug sections. */ |
| 149 | static bool reloc_debug; |
| 150 | |
| 151 | |
| 152 | int |
| 153 | main (int argc, char *argv[]) |
| 154 | { |
| 155 | int remaining; |
| 156 | int result = 0; |
| 157 | |
| 158 | /* Make memory leak detection possible. */ |
| 159 | mtrace (); |
| 160 | |
| 161 | /* We use no threads here which can interfere with handling a stream. */ |
| 162 | __fsetlocking (stdin, FSETLOCKING_BYCALLER); |
| 163 | __fsetlocking (stdout, FSETLOCKING_BYCALLER); |
| 164 | __fsetlocking (stderr, FSETLOCKING_BYCALLER); |
| 165 | |
| 166 | /* Set locale. */ |
| 167 | setlocale (LC_ALL, ""); |
| 168 | |
| 169 | /* Make sure the message catalog can be found. */ |
| 170 | bindtextdomain (PACKAGE_TARNAME, LOCALEDIR); |
| 171 | |
| 172 | /* Initialize the message catalog. */ |
| 173 | textdomain (PACKAGE_TARNAME); |
| 174 | |
| 175 | /* Parse and process arguments. */ |
| 176 | if (argp_parse (&argp, argc, argv, 0, &remaining, NULL) != 0) |
| 177 | return EXIT_FAILURE; |
| 178 | |
| 179 | if (reloc_debug && debug_fname == NULL) |
| 180 | error (EXIT_FAILURE, 0, |
| 181 | gettext ("--reloc-debug-sections used without -f")); |
| 182 | |
| 183 | /* Tell the library which version we are expecting. */ |
| 184 | elf_version (EV_CURRENT); |
| 185 | |
| 186 | if (remaining == argc) |
| 187 | /* The user didn't specify a name so we use a.out. */ |
| 188 | result = process_file ("a.out"); |
| 189 | else |
| 190 | { |
| 191 | /* If we have seen the '-o' or '-f' option there must be exactly one |
| 192 | input file. */ |
| 193 | if ((output_fname != NULL || debug_fname != NULL) |
| 194 | && remaining + 1 < argc) |
| 195 | error (EXIT_FAILURE, 0, gettext ("\ |
| 196 | Only one input file allowed together with '-o' and '-f'")); |
| 197 | |
| 198 | /* Process all the remaining files. */ |
| 199 | do |
| 200 | result |= process_file (argv[remaining]); |
| 201 | while (++remaining < argc); |
| 202 | } |
| 203 | |
| 204 | return result; |
| 205 | } |
| 206 | |
| 207 | |
| 208 | /* Print the version information. */ |
| 209 | static void |
| 210 | print_version (FILE *stream, struct argp_state *state __attribute__ ((unused))) |
| 211 | { |
| 212 | fprintf (stream, "strip (%s) %s\n", PACKAGE_NAME, PACKAGE_VERSION); |
| 213 | fprintf (stream, gettext ("\ |
| 214 | Copyright (C) %s Red Hat, Inc.\n\ |
| 215 | This is free software; see the source for copying conditions. There is NO\n\ |
| 216 | warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\ |
| 217 | "), "2012"); |
| 218 | fprintf (stream, gettext ("Written by %s.\n"), "Ulrich Drepper"); |
| 219 | } |
| 220 | |
| 221 | |
| 222 | /* Handle program arguments. */ |
| 223 | static error_t |
| 224 | parse_opt (int key, char *arg, struct argp_state *state) |
| 225 | { |
| 226 | switch (key) |
| 227 | { |
| 228 | case 'f': |
| 229 | if (debug_fname != NULL) |
| 230 | { |
| 231 | error (0, 0, gettext ("-f option specified twice")); |
| 232 | return EINVAL; |
| 233 | } |
| 234 | debug_fname = arg; |
| 235 | break; |
| 236 | |
| 237 | case 'F': |
| 238 | if (debug_fname_embed != NULL) |
| 239 | { |
| 240 | error (0, 0, gettext ("-F option specified twice")); |
| 241 | return EINVAL; |
| 242 | } |
| 243 | debug_fname_embed = arg; |
| 244 | break; |
| 245 | |
| 246 | case 'o': |
| 247 | if (output_fname != NULL) |
| 248 | { |
| 249 | error (0, 0, gettext ("-o option specified twice")); |
| 250 | return EINVAL; |
| 251 | } |
| 252 | output_fname = arg; |
| 253 | break; |
| 254 | |
| 255 | case 'p': |
| 256 | preserve_dates = true; |
| 257 | break; |
| 258 | |
| 259 | case OPT_RELOC_DEBUG: |
| 260 | reloc_debug = true; |
| 261 | break; |
| 262 | |
| 263 | case OPT_REMOVE_COMMENT: |
| 264 | remove_comment = true; |
| 265 | break; |
| 266 | |
| 267 | case 'R': |
| 268 | if (!strcmp (arg, ".comment")) |
| 269 | remove_comment = true; |
| 270 | else |
| 271 | { |
| 272 | argp_error (state, |
| 273 | gettext ("-R option supports only .comment section")); |
| 274 | return EINVAL; |
| 275 | } |
| 276 | break; |
| 277 | |
| 278 | case 'g': |
| 279 | case 'd': |
| 280 | case 'S': |
| 281 | remove_debug = true; |
| 282 | break; |
| 283 | |
| 284 | case OPT_STRIP_SECTIONS: |
| 285 | remove_shdrs = true; |
| 286 | break; |
| 287 | |
| 288 | case OPT_PERMISSIVE: |
| 289 | permissive = true; |
| 290 | break; |
| 291 | |
| 292 | case 's': /* Ignored for compatibility. */ |
| 293 | break; |
| 294 | |
| 295 | default: |
| 296 | return ARGP_ERR_UNKNOWN; |
| 297 | } |
| 298 | return 0; |
| 299 | } |
| 300 | |
| 301 | |
| 302 | static int |
| 303 | process_file (const char *fname) |
| 304 | { |
| 305 | /* If we have to preserve the modify and access timestamps get them |
| 306 | now. We cannot use fstat() after opening the file since the open |
| 307 | would change the access time. */ |
| 308 | struct stat64 pre_st; |
| 309 | struct timeval tv[2]; |
| 310 | again: |
| 311 | if (preserve_dates) |
| 312 | { |
| 313 | if (stat64 (fname, &pre_st) != 0) |
| 314 | { |
| 315 | error (0, errno, gettext ("cannot stat input file '%s'"), fname); |
| 316 | return 1; |
| 317 | } |
| 318 | |
| 319 | /* If we have to preserve the timestamp, we need it in the |
| 320 | format utimes() understands. */ |
| 321 | TIMESPEC_TO_TIMEVAL (&tv[0], &pre_st.st_atim); |
| 322 | TIMESPEC_TO_TIMEVAL (&tv[1], &pre_st.st_mtim); |
| 323 | } |
| 324 | |
| 325 | /* Open the file. */ |
| 326 | int fd = open (fname, output_fname == NULL ? O_RDWR : O_RDONLY); |
| 327 | if (fd == -1) |
| 328 | { |
| 329 | error (0, errno, gettext ("while opening '%s'"), fname); |
| 330 | return 1; |
| 331 | } |
| 332 | |
| 333 | /* We always use fstat() even if we called stat() before. This is |
| 334 | done to make sure the information returned by stat() is for the |
| 335 | same file. */ |
| 336 | struct stat64 st; |
| 337 | if (fstat64 (fd, &st) != 0) |
| 338 | { |
| 339 | error (0, errno, gettext ("cannot stat input file '%s'"), fname); |
| 340 | return 1; |
| 341 | } |
| 342 | /* Paranoid mode on. */ |
| 343 | if (preserve_dates |
| 344 | && (st.st_ino != pre_st.st_ino || st.st_dev != pre_st.st_dev)) |
| 345 | { |
| 346 | /* We detected a race. Try again. */ |
| 347 | close (fd); |
| 348 | goto again; |
| 349 | } |
| 350 | |
| 351 | /* Now get the ELF descriptor. */ |
| 352 | Elf *elf = elf_begin (fd, output_fname == NULL ? ELF_C_RDWR : ELF_C_READ, |
| 353 | NULL); |
| 354 | int result; |
| 355 | switch (elf_kind (elf)) |
| 356 | { |
| 357 | case ELF_K_ELF: |
| 358 | result = handle_elf (fd, elf, NULL, fname, st.st_mode & ACCESSPERMS, |
| 359 | preserve_dates ? tv : NULL); |
| 360 | break; |
| 361 | |
| 362 | case ELF_K_AR: |
| 363 | /* It is not possible to strip the content of an archive direct |
| 364 | the output to a specific file. */ |
| 365 | if (unlikely (output_fname != NULL || debug_fname != NULL)) |
| 366 | { |
| 367 | error (0, 0, gettext ("%s: cannot use -o or -f when stripping archive"), |
| 368 | fname); |
| 369 | result = 1; |
| 370 | } |
| 371 | else |
| 372 | result = handle_ar (fd, elf, NULL, fname, preserve_dates ? tv : NULL); |
| 373 | break; |
| 374 | |
| 375 | default: |
| 376 | error (0, 0, gettext ("%s: File format not recognized"), fname); |
| 377 | result = 1; |
| 378 | break; |
| 379 | } |
| 380 | |
| 381 | if (unlikely (elf_end (elf) != 0)) |
| 382 | INTERNAL_ERROR (fname); |
| 383 | |
| 384 | close (fd); |
| 385 | |
| 386 | return result; |
| 387 | } |
| 388 | |
| 389 | |
| 390 | /* Maximum size of array allocated on stack. */ |
| 391 | #define MAX_STACK_ALLOC (400 * 1024) |
| 392 | |
| 393 | static int |
| 394 | handle_elf (int fd, Elf *elf, const char *prefix, const char *fname, |
| 395 | mode_t mode, struct timeval tvp[2]) |
| 396 | { |
| 397 | size_t prefix_len = prefix == NULL ? 0 : strlen (prefix); |
| 398 | size_t fname_len = strlen (fname) + 1; |
| 399 | char *fullname = alloca (prefix_len + 1 + fname_len); |
| 400 | char *cp = fullname; |
| 401 | Elf *debugelf = NULL; |
| 402 | char *tmp_debug_fname = NULL; |
| 403 | int result = 0; |
| 404 | size_t shdridx = 0; |
| 405 | size_t shstrndx; |
| 406 | struct shdr_info |
| 407 | { |
| 408 | Elf_Scn *scn; |
| 409 | GElf_Shdr shdr; |
| 410 | Elf_Data *data; |
| 411 | Elf_Data *debug_data; |
| 412 | const char *name; |
| 413 | Elf32_Word idx; /* Index in new file. */ |
| 414 | Elf32_Word old_sh_link; /* Original value of shdr.sh_link. */ |
| 415 | Elf32_Word symtab_idx; |
| 416 | Elf32_Word version_idx; |
| 417 | Elf32_Word group_idx; |
| 418 | Elf32_Word group_cnt; |
| 419 | Elf_Scn *newscn; |
| 420 | struct Ebl_Strent *se; |
| 421 | Elf32_Word *newsymidx; |
| 422 | } *shdr_info = NULL; |
| 423 | Elf_Scn *scn; |
| 424 | size_t cnt; |
| 425 | size_t idx; |
| 426 | bool changes; |
| 427 | GElf_Ehdr newehdr_mem; |
| 428 | GElf_Ehdr *newehdr; |
| 429 | GElf_Ehdr debugehdr_mem; |
| 430 | GElf_Ehdr *debugehdr; |
| 431 | struct Ebl_Strtab *shst = NULL; |
| 432 | Elf_Data debuglink_crc_data; |
| 433 | bool any_symtab_changes = false; |
| 434 | Elf_Data *shstrtab_data = NULL; |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 435 | void *debuglink_buf = NULL; |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 436 | |
| 437 | /* Create the full name of the file. */ |
| 438 | if (prefix != NULL) |
| 439 | { |
| 440 | cp = mempcpy (cp, prefix, prefix_len); |
| 441 | *cp++ = ':'; |
| 442 | } |
| 443 | memcpy (cp, fname, fname_len); |
| 444 | |
| 445 | /* If we are not replacing the input file open a new file here. */ |
| 446 | if (output_fname != NULL) |
| 447 | { |
| 448 | fd = open (output_fname, O_RDWR | O_CREAT, mode); |
| 449 | if (unlikely (fd == -1)) |
| 450 | { |
| 451 | error (0, errno, gettext ("cannot open '%s'"), output_fname); |
| 452 | return 1; |
| 453 | } |
| 454 | } |
| 455 | |
| 456 | int debug_fd = -1; |
| 457 | |
| 458 | /* Get the EBL handling. Removing all debugging symbols with the -g |
| 459 | option or resolving all relocations between debug sections with |
| 460 | the --reloc-debug-sections option are currently the only reasons |
| 461 | we need EBL so don't open the backend unless necessary. */ |
| 462 | Ebl *ebl = NULL; |
| 463 | if (remove_debug || reloc_debug) |
| 464 | { |
| 465 | ebl = ebl_openbackend (elf); |
| 466 | if (ebl == NULL) |
| 467 | { |
| 468 | error (0, errno, gettext ("cannot open EBL backend")); |
| 469 | result = 1; |
| 470 | goto fail; |
| 471 | } |
| 472 | } |
| 473 | |
| 474 | /* Open the additional file the debug information will be stored in. */ |
| 475 | if (debug_fname != NULL) |
| 476 | { |
| 477 | /* Create a temporary file name. We do not want to overwrite |
| 478 | the debug file if the file would not contain any |
| 479 | information. */ |
| 480 | size_t debug_fname_len = strlen (debug_fname); |
| 481 | tmp_debug_fname = (char *) alloca (debug_fname_len + sizeof (".XXXXXX")); |
| 482 | strcpy (mempcpy (tmp_debug_fname, debug_fname, debug_fname_len), |
| 483 | ".XXXXXX"); |
| 484 | |
| 485 | debug_fd = mkstemp (tmp_debug_fname); |
| 486 | if (unlikely (debug_fd == -1)) |
| 487 | { |
| 488 | error (0, errno, gettext ("cannot open '%s'"), debug_fname); |
| 489 | result = 1; |
| 490 | goto fail; |
| 491 | } |
| 492 | } |
| 493 | |
| 494 | /* Get the information from the old file. */ |
| 495 | GElf_Ehdr ehdr_mem; |
| 496 | GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem); |
| 497 | if (ehdr == NULL) |
| 498 | INTERNAL_ERROR (fname); |
| 499 | |
| 500 | /* Get the section header string table index. */ |
| 501 | if (unlikely (elf_getshdrstrndx (elf, &shstrndx) < 0)) |
| 502 | error (EXIT_FAILURE, 0, |
| 503 | gettext ("cannot get section header string table index")); |
| 504 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 505 | /* Get the number of phdrs in the old file. */ |
| 506 | size_t phnum; |
| 507 | if (elf_getphdrnum (elf, &phnum) != 0) |
| 508 | error (EXIT_FAILURE, 0, gettext ("cannot get number of phdrs")); |
| 509 | |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 510 | /* We now create a new ELF descriptor for the same file. We |
| 511 | construct it almost exactly in the same way with some information |
| 512 | dropped. */ |
| 513 | Elf *newelf; |
| 514 | if (output_fname != NULL) |
| 515 | newelf = elf_begin (fd, ELF_C_WRITE_MMAP, NULL); |
| 516 | else |
| 517 | newelf = elf_clone (elf, ELF_C_EMPTY); |
| 518 | |
| 519 | if (unlikely (gelf_newehdr (newelf, gelf_getclass (elf)) == 0) |
| 520 | || (ehdr->e_type != ET_REL |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 521 | && unlikely (gelf_newphdr (newelf, phnum) == 0))) |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 522 | { |
| 523 | error (0, 0, gettext ("cannot create new file '%s': %s"), |
| 524 | output_fname, elf_errmsg (-1)); |
| 525 | goto fail; |
| 526 | } |
| 527 | |
| 528 | /* Copy over the old program header if needed. */ |
| 529 | if (ehdr->e_type != ET_REL) |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 530 | for (cnt = 0; cnt < phnum; ++cnt) |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 531 | { |
| 532 | GElf_Phdr phdr_mem; |
| 533 | GElf_Phdr *phdr = gelf_getphdr (elf, cnt, &phdr_mem); |
| 534 | if (phdr == NULL |
| 535 | || unlikely (gelf_update_phdr (newelf, cnt, phdr) == 0)) |
| 536 | INTERNAL_ERROR (fname); |
| 537 | } |
| 538 | |
| 539 | if (debug_fname != NULL) |
| 540 | { |
| 541 | /* Also create an ELF descriptor for the debug file */ |
| 542 | debugelf = elf_begin (debug_fd, ELF_C_WRITE_MMAP, NULL); |
| 543 | if (unlikely (gelf_newehdr (debugelf, gelf_getclass (elf)) == 0) |
| 544 | || (ehdr->e_type != ET_REL |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 545 | && unlikely (gelf_newphdr (debugelf, phnum) == 0))) |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 546 | { |
| 547 | error (0, 0, gettext ("cannot create new file '%s': %s"), |
| 548 | debug_fname, elf_errmsg (-1)); |
| 549 | goto fail_close; |
| 550 | } |
| 551 | |
| 552 | /* Copy over the old program header if needed. */ |
| 553 | if (ehdr->e_type != ET_REL) |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 554 | for (cnt = 0; cnt < phnum; ++cnt) |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 555 | { |
| 556 | GElf_Phdr phdr_mem; |
| 557 | GElf_Phdr *phdr = gelf_getphdr (elf, cnt, &phdr_mem); |
| 558 | if (phdr == NULL |
| 559 | || unlikely (gelf_update_phdr (debugelf, cnt, phdr) == 0)) |
| 560 | INTERNAL_ERROR (fname); |
| 561 | } |
| 562 | } |
| 563 | |
| 564 | /* Number of sections. */ |
| 565 | size_t shnum; |
| 566 | if (unlikely (elf_getshdrnum (elf, &shnum) < 0)) |
| 567 | { |
| 568 | error (0, 0, gettext ("cannot determine number of sections: %s"), |
| 569 | elf_errmsg (-1)); |
| 570 | goto fail_close; |
| 571 | } |
| 572 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 573 | if (shstrndx >= shnum) |
| 574 | goto illformed; |
| 575 | |
| 576 | #define elf_assert(test) do { if (!(test)) goto illformed; } while (0) |
| 577 | |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 578 | /* Storage for section information. We leave room for two more |
| 579 | entries since we unconditionally create a section header string |
| 580 | table. Maybe some weird tool created an ELF file without one. |
| 581 | The other one is used for the debug link section. */ |
| 582 | if ((shnum + 2) * sizeof (struct shdr_info) > MAX_STACK_ALLOC) |
| 583 | shdr_info = (struct shdr_info *) xcalloc (shnum + 2, |
| 584 | sizeof (struct shdr_info)); |
| 585 | else |
| 586 | { |
| 587 | shdr_info = (struct shdr_info *) alloca ((shnum + 2) |
| 588 | * sizeof (struct shdr_info)); |
| 589 | memset (shdr_info, '\0', (shnum + 2) * sizeof (struct shdr_info)); |
| 590 | } |
| 591 | |
| 592 | /* Prepare section information data structure. */ |
| 593 | scn = NULL; |
| 594 | cnt = 1; |
| 595 | while ((scn = elf_nextscn (elf, scn)) != NULL) |
| 596 | { |
| 597 | /* This should always be true (i.e., there should not be any |
| 598 | holes in the numbering). */ |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 599 | elf_assert (elf_ndxscn (scn) == cnt); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 600 | |
| 601 | shdr_info[cnt].scn = scn; |
| 602 | |
| 603 | /* Get the header. */ |
| 604 | if (gelf_getshdr (scn, &shdr_info[cnt].shdr) == NULL) |
| 605 | INTERNAL_ERROR (fname); |
| 606 | |
| 607 | /* Get the name of the section. */ |
| 608 | shdr_info[cnt].name = elf_strptr (elf, shstrndx, |
| 609 | shdr_info[cnt].shdr.sh_name); |
| 610 | if (shdr_info[cnt].name == NULL) |
| 611 | { |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 612 | illformed: |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 613 | error (0, 0, gettext ("illformed file '%s'"), fname); |
| 614 | goto fail_close; |
| 615 | } |
| 616 | |
| 617 | /* Mark them as present but not yet investigated. */ |
| 618 | shdr_info[cnt].idx = 1; |
| 619 | |
| 620 | /* Remember the shdr.sh_link value. */ |
| 621 | shdr_info[cnt].old_sh_link = shdr_info[cnt].shdr.sh_link; |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 622 | if (shdr_info[cnt].old_sh_link >= shnum) |
| 623 | goto illformed; |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 624 | |
| 625 | /* Sections in files other than relocatable object files which |
| 626 | are not loaded can be freely moved by us. In relocatable |
| 627 | object files everything can be moved. */ |
| 628 | if (ehdr->e_type == ET_REL |
| 629 | || (shdr_info[cnt].shdr.sh_flags & SHF_ALLOC) == 0) |
| 630 | shdr_info[cnt].shdr.sh_offset = 0; |
| 631 | |
| 632 | /* If this is an extended section index table store an |
| 633 | appropriate reference. */ |
| 634 | if (unlikely (shdr_info[cnt].shdr.sh_type == SHT_SYMTAB_SHNDX)) |
| 635 | { |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 636 | elf_assert (shdr_info[shdr_info[cnt].shdr.sh_link].symtab_idx == 0); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 637 | shdr_info[shdr_info[cnt].shdr.sh_link].symtab_idx = cnt; |
| 638 | } |
| 639 | else if (unlikely (shdr_info[cnt].shdr.sh_type == SHT_GROUP)) |
| 640 | { |
| 641 | /* Cross-reference the sections contained in the section |
| 642 | group. */ |
| 643 | shdr_info[cnt].data = elf_getdata (shdr_info[cnt].scn, NULL); |
| 644 | if (shdr_info[cnt].data == NULL) |
| 645 | INTERNAL_ERROR (fname); |
| 646 | |
| 647 | /* XXX Fix for unaligned access. */ |
| 648 | Elf32_Word *grpref = (Elf32_Word *) shdr_info[cnt].data->d_buf; |
| 649 | size_t inner; |
| 650 | for (inner = 1; |
| 651 | inner < shdr_info[cnt].data->d_size / sizeof (Elf32_Word); |
| 652 | ++inner) |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 653 | { |
| 654 | if (grpref[inner] < shnum) |
| 655 | shdr_info[grpref[inner]].group_idx = cnt; |
| 656 | else |
| 657 | goto illformed; |
| 658 | } |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 659 | |
| 660 | if (inner == 1 || (inner == 2 && (grpref[0] & GRP_COMDAT) == 0)) |
| 661 | /* If the section group contains only one element and this |
| 662 | is n COMDAT section we can drop it right away. */ |
| 663 | shdr_info[cnt].idx = 0; |
| 664 | else |
| 665 | shdr_info[cnt].group_cnt = inner - 1; |
| 666 | } |
| 667 | else if (unlikely (shdr_info[cnt].shdr.sh_type == SHT_GNU_versym)) |
| 668 | { |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 669 | elf_assert (shdr_info[shdr_info[cnt].shdr.sh_link].version_idx == 0); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 670 | shdr_info[shdr_info[cnt].shdr.sh_link].version_idx = cnt; |
| 671 | } |
| 672 | |
| 673 | /* If this section is part of a group make sure it is not |
| 674 | discarded right away. */ |
| 675 | if ((shdr_info[cnt].shdr.sh_flags & SHF_GROUP) != 0) |
| 676 | { |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 677 | elf_assert (shdr_info[cnt].group_idx != 0); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 678 | |
| 679 | if (shdr_info[shdr_info[cnt].group_idx].idx == 0) |
| 680 | { |
| 681 | /* The section group section will be removed. */ |
| 682 | shdr_info[cnt].group_idx = 0; |
| 683 | shdr_info[cnt].shdr.sh_flags &= ~SHF_GROUP; |
| 684 | } |
| 685 | } |
| 686 | |
| 687 | /* Increment the counter. */ |
| 688 | ++cnt; |
| 689 | } |
| 690 | |
| 691 | /* Now determine which sections can go away. The general rule is that |
| 692 | all sections which are not used at runtime are stripped out. But |
| 693 | there are a few exceptions: |
| 694 | |
| 695 | - special sections named ".comment" and ".note" are kept |
| 696 | - OS or architecture specific sections are kept since we might not |
| 697 | know how to handle them |
| 698 | - if a section is referred to from a section which is not removed |
| 699 | in the sh_link or sh_info element it cannot be removed either |
| 700 | */ |
| 701 | for (cnt = 1; cnt < shnum; ++cnt) |
| 702 | /* Check whether the section can be removed. */ |
| 703 | if (remove_shdrs ? !(shdr_info[cnt].shdr.sh_flags & SHF_ALLOC) |
| 704 | : ebl_section_strip_p (ebl, ehdr, &shdr_info[cnt].shdr, |
| 705 | shdr_info[cnt].name, remove_comment, |
| 706 | remove_debug)) |
| 707 | { |
| 708 | /* For now assume this section will be removed. */ |
| 709 | shdr_info[cnt].idx = 0; |
| 710 | |
| 711 | idx = shdr_info[cnt].group_idx; |
| 712 | while (idx != 0) |
| 713 | { |
| 714 | /* The section group data is already loaded. */ |
| 715 | assert (shdr_info[idx].data != NULL); |
| 716 | |
| 717 | /* If the references section group is a normal section |
| 718 | group and has one element remaining, or if it is an |
| 719 | empty COMDAT section group it is removed. */ |
| 720 | bool is_comdat = (((Elf32_Word *) shdr_info[idx].data->d_buf)[0] |
| 721 | & GRP_COMDAT) != 0; |
| 722 | |
| 723 | --shdr_info[idx].group_cnt; |
| 724 | if ((!is_comdat && shdr_info[idx].group_cnt == 1) |
| 725 | || (is_comdat && shdr_info[idx].group_cnt == 0)) |
| 726 | { |
| 727 | shdr_info[idx].idx = 0; |
| 728 | /* Continue recursively. */ |
| 729 | idx = shdr_info[idx].group_idx; |
| 730 | } |
| 731 | else |
| 732 | break; |
| 733 | } |
| 734 | } |
| 735 | |
| 736 | /* Mark the SHT_NULL section as handled. */ |
| 737 | shdr_info[0].idx = 2; |
| 738 | |
| 739 | |
| 740 | /* Handle exceptions: section groups and cross-references. We might |
| 741 | have to repeat this a few times since the resetting of the flag |
| 742 | might propagate. */ |
| 743 | do |
| 744 | { |
| 745 | changes = false; |
| 746 | |
| 747 | for (cnt = 1; cnt < shnum; ++cnt) |
| 748 | { |
| 749 | if (shdr_info[cnt].idx == 0) |
| 750 | { |
| 751 | /* If a relocation section is marked as being removed make |
| 752 | sure the section it is relocating is removed, too. */ |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 753 | if (shdr_info[cnt].shdr.sh_type == SHT_REL |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 754 | || shdr_info[cnt].shdr.sh_type == SHT_RELA) |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 755 | { |
| 756 | if (shdr_info[cnt].shdr.sh_info >= shnum) |
| 757 | goto illformed; |
| 758 | else if (shdr_info[shdr_info[cnt].shdr.sh_info].idx != 0) |
| 759 | shdr_info[cnt].idx = 1; |
| 760 | } |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 761 | |
| 762 | /* If a group section is marked as being removed make |
| 763 | sure all the sections it contains are being removed, too. */ |
| 764 | if (shdr_info[cnt].shdr.sh_type == SHT_GROUP) |
| 765 | { |
| 766 | Elf32_Word *grpref; |
| 767 | grpref = (Elf32_Word *) shdr_info[cnt].data->d_buf; |
| 768 | for (size_t in = 1; |
| 769 | in < shdr_info[cnt].data->d_size / sizeof (Elf32_Word); |
| 770 | ++in) |
| 771 | if (shdr_info[grpref[in]].idx != 0) |
| 772 | { |
| 773 | shdr_info[cnt].idx = 1; |
| 774 | break; |
| 775 | } |
| 776 | } |
| 777 | } |
| 778 | |
| 779 | if (shdr_info[cnt].idx == 1) |
| 780 | { |
| 781 | /* The content of symbol tables we don't remove must not |
| 782 | reference any section which we do remove. Otherwise |
| 783 | we cannot remove the section. */ |
| 784 | if (debug_fname != NULL |
| 785 | && shdr_info[cnt].debug_data == NULL |
| 786 | && (shdr_info[cnt].shdr.sh_type == SHT_DYNSYM |
| 787 | || shdr_info[cnt].shdr.sh_type == SHT_SYMTAB)) |
| 788 | { |
| 789 | /* Make sure the data is loaded. */ |
| 790 | if (shdr_info[cnt].data == NULL) |
| 791 | { |
| 792 | shdr_info[cnt].data |
| 793 | = elf_getdata (shdr_info[cnt].scn, NULL); |
| 794 | if (shdr_info[cnt].data == NULL) |
| 795 | INTERNAL_ERROR (fname); |
| 796 | } |
| 797 | Elf_Data *symdata = shdr_info[cnt].data; |
| 798 | |
| 799 | /* If there is an extended section index table load it |
| 800 | as well. */ |
| 801 | if (shdr_info[cnt].symtab_idx != 0 |
| 802 | && shdr_info[shdr_info[cnt].symtab_idx].data == NULL) |
| 803 | { |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 804 | elf_assert (shdr_info[cnt].shdr.sh_type == SHT_SYMTAB); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 805 | |
| 806 | shdr_info[shdr_info[cnt].symtab_idx].data |
| 807 | = elf_getdata (shdr_info[shdr_info[cnt].symtab_idx].scn, |
| 808 | NULL); |
| 809 | if (shdr_info[shdr_info[cnt].symtab_idx].data == NULL) |
| 810 | INTERNAL_ERROR (fname); |
| 811 | } |
| 812 | Elf_Data *xndxdata |
| 813 | = shdr_info[shdr_info[cnt].symtab_idx].data; |
| 814 | |
| 815 | /* Go through all symbols and make sure the section they |
| 816 | reference is not removed. */ |
| 817 | size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, |
| 818 | ehdr->e_version); |
| 819 | |
| 820 | for (size_t inner = 0; |
| 821 | inner < shdr_info[cnt].data->d_size / elsize; |
| 822 | ++inner) |
| 823 | { |
| 824 | GElf_Sym sym_mem; |
| 825 | Elf32_Word xndx; |
| 826 | GElf_Sym *sym = gelf_getsymshndx (symdata, xndxdata, |
| 827 | inner, &sym_mem, |
| 828 | &xndx); |
| 829 | if (sym == NULL) |
| 830 | INTERNAL_ERROR (fname); |
| 831 | |
| 832 | size_t scnidx = sym->st_shndx; |
| 833 | if (scnidx == SHN_UNDEF || scnidx >= shnum |
| 834 | || (scnidx >= SHN_LORESERVE |
| 835 | && scnidx <= SHN_HIRESERVE |
| 836 | && scnidx != SHN_XINDEX) |
| 837 | /* Don't count in the section symbols. */ |
| 838 | || GELF_ST_TYPE (sym->st_info) == STT_SECTION) |
| 839 | /* This is no section index, leave it alone. */ |
| 840 | continue; |
| 841 | else if (scnidx == SHN_XINDEX) |
| 842 | scnidx = xndx; |
| 843 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 844 | if (scnidx >= shnum) |
| 845 | goto illformed; |
| 846 | |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 847 | if (shdr_info[scnidx].idx == 0) |
| 848 | /* This symbol table has a real symbol in |
| 849 | a discarded section. So preserve the |
| 850 | original table in the debug file. */ |
| 851 | shdr_info[cnt].debug_data = symdata; |
| 852 | } |
| 853 | } |
| 854 | |
| 855 | /* Cross referencing happens: |
| 856 | - for the cases the ELF specification says. That are |
| 857 | + SHT_DYNAMIC in sh_link to string table |
| 858 | + SHT_HASH in sh_link to symbol table |
| 859 | + SHT_REL and SHT_RELA in sh_link to symbol table |
| 860 | + SHT_SYMTAB and SHT_DYNSYM in sh_link to string table |
| 861 | + SHT_GROUP in sh_link to symbol table |
| 862 | + SHT_SYMTAB_SHNDX in sh_link to symbol table |
| 863 | Other (OS or architecture-specific) sections might as |
| 864 | well use this field so we process it unconditionally. |
| 865 | - references inside section groups |
| 866 | - specially marked references in sh_info if the SHF_INFO_LINK |
| 867 | flag is set |
| 868 | */ |
| 869 | |
| 870 | if (shdr_info[shdr_info[cnt].shdr.sh_link].idx == 0) |
| 871 | { |
| 872 | shdr_info[shdr_info[cnt].shdr.sh_link].idx = 1; |
| 873 | changes |= shdr_info[cnt].shdr.sh_link < cnt; |
| 874 | } |
| 875 | |
| 876 | /* Handle references through sh_info. */ |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 877 | if (SH_INFO_LINK_P (&shdr_info[cnt].shdr)) |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 878 | { |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 879 | if (shdr_info[cnt].shdr.sh_info >= shnum) |
| 880 | goto illformed; |
| 881 | else if ( shdr_info[shdr_info[cnt].shdr.sh_info].idx == 0) |
| 882 | { |
| 883 | shdr_info[shdr_info[cnt].shdr.sh_info].idx = 1; |
| 884 | changes |= shdr_info[cnt].shdr.sh_info < cnt; |
| 885 | } |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 886 | } |
| 887 | |
| 888 | /* Mark the section as investigated. */ |
| 889 | shdr_info[cnt].idx = 2; |
| 890 | } |
| 891 | |
| 892 | if (debug_fname != NULL |
| 893 | && (shdr_info[cnt].idx == 0 || shdr_info[cnt].debug_data != NULL)) |
| 894 | { |
| 895 | /* This section is being preserved in the debug file. |
| 896 | Sections it refers to must be preserved there too. |
| 897 | |
| 898 | In this pass we mark sections to be preserved in both |
| 899 | files by setting the .debug_data pointer to the original |
| 900 | file's .data pointer. Below, we'll copy the section |
| 901 | contents. */ |
| 902 | |
| 903 | inline void check_preserved (size_t i) |
| 904 | { |
| 905 | if (i != 0 && shdr_info[i].idx != 0 |
| 906 | && shdr_info[i].debug_data == NULL) |
| 907 | { |
| 908 | if (shdr_info[i].data == NULL) |
| 909 | shdr_info[i].data = elf_getdata (shdr_info[i].scn, NULL); |
| 910 | if (shdr_info[i].data == NULL) |
| 911 | INTERNAL_ERROR (fname); |
| 912 | |
| 913 | shdr_info[i].debug_data = shdr_info[i].data; |
| 914 | changes |= i < cnt; |
| 915 | } |
| 916 | } |
| 917 | |
| 918 | check_preserved (shdr_info[cnt].shdr.sh_link); |
| 919 | if (SH_INFO_LINK_P (&shdr_info[cnt].shdr)) |
| 920 | check_preserved (shdr_info[cnt].shdr.sh_info); |
| 921 | } |
| 922 | } |
| 923 | } |
| 924 | while (changes); |
| 925 | |
| 926 | /* Copy the removed sections to the debug output file. |
| 927 | The ones that are not removed in the stripped file are SHT_NOBITS. */ |
| 928 | if (debug_fname != NULL) |
| 929 | { |
| 930 | for (cnt = 1; cnt < shnum; ++cnt) |
| 931 | { |
| 932 | scn = elf_newscn (debugelf); |
| 933 | if (scn == NULL) |
| 934 | error (EXIT_FAILURE, 0, |
| 935 | gettext ("while generating output file: %s"), |
| 936 | elf_errmsg (-1)); |
| 937 | |
| 938 | bool discard_section = (shdr_info[cnt].idx > 0 |
| 939 | && shdr_info[cnt].debug_data == NULL |
| 940 | && shdr_info[cnt].shdr.sh_type != SHT_NOTE |
| 941 | && shdr_info[cnt].shdr.sh_type != SHT_GROUP |
| 942 | && cnt != ehdr->e_shstrndx); |
| 943 | |
| 944 | /* Set the section header in the new file. */ |
| 945 | GElf_Shdr debugshdr = shdr_info[cnt].shdr; |
| 946 | if (discard_section) |
| 947 | debugshdr.sh_type = SHT_NOBITS; |
| 948 | |
| 949 | if (unlikely (gelf_update_shdr (scn, &debugshdr) == 0)) |
| 950 | /* There cannot be any overflows. */ |
| 951 | INTERNAL_ERROR (fname); |
| 952 | |
| 953 | /* Get the data from the old file if necessary. */ |
| 954 | if (shdr_info[cnt].data == NULL) |
| 955 | { |
| 956 | shdr_info[cnt].data = elf_getdata (shdr_info[cnt].scn, NULL); |
| 957 | if (shdr_info[cnt].data == NULL) |
| 958 | INTERNAL_ERROR (fname); |
| 959 | } |
| 960 | |
| 961 | /* Set the data. This is done by copying from the old file. */ |
| 962 | Elf_Data *debugdata = elf_newdata (scn); |
| 963 | if (debugdata == NULL) |
| 964 | INTERNAL_ERROR (fname); |
| 965 | |
| 966 | /* Copy the structure. This data may be modified in place |
| 967 | before we write out the file. */ |
| 968 | *debugdata = *shdr_info[cnt].data; |
| 969 | if (discard_section) |
| 970 | debugdata->d_buf = NULL; |
| 971 | else if (shdr_info[cnt].debug_data != NULL |
| 972 | || shdr_info[cnt].shdr.sh_type == SHT_GROUP) |
| 973 | { |
| 974 | /* Copy the original data before it gets modified. */ |
| 975 | shdr_info[cnt].debug_data = debugdata; |
| 976 | debugdata->d_buf = memcpy (xmalloc (debugdata->d_size), |
| 977 | debugdata->d_buf, debugdata->d_size); |
| 978 | } |
| 979 | } |
| 980 | |
| 981 | /* Finish the ELF header. Fill in the fields not handled by |
| 982 | libelf from the old file. */ |
| 983 | debugehdr = gelf_getehdr (debugelf, &debugehdr_mem); |
| 984 | if (debugehdr == NULL) |
| 985 | INTERNAL_ERROR (fname); |
| 986 | |
| 987 | memcpy (debugehdr->e_ident, ehdr->e_ident, EI_NIDENT); |
| 988 | debugehdr->e_type = ehdr->e_type; |
| 989 | debugehdr->e_machine = ehdr->e_machine; |
| 990 | debugehdr->e_version = ehdr->e_version; |
| 991 | debugehdr->e_entry = ehdr->e_entry; |
| 992 | debugehdr->e_flags = ehdr->e_flags; |
| 993 | debugehdr->e_shstrndx = ehdr->e_shstrndx; |
| 994 | |
| 995 | if (unlikely (gelf_update_ehdr (debugelf, debugehdr) == 0)) |
| 996 | { |
| 997 | error (0, 0, gettext ("%s: error while creating ELF header: %s"), |
| 998 | debug_fname, elf_errmsg (-1)); |
| 999 | result = 1; |
| 1000 | goto fail_close; |
| 1001 | } |
| 1002 | } |
| 1003 | |
| 1004 | /* Mark the section header string table as unused, we will create |
| 1005 | a new one. */ |
| 1006 | shdr_info[shstrndx].idx = 0; |
| 1007 | |
| 1008 | /* We need a string table for the section headers. */ |
| 1009 | shst = ebl_strtabinit (true); |
| 1010 | if (shst == NULL) |
| 1011 | error (EXIT_FAILURE, errno, gettext ("while preparing output for '%s'"), |
| 1012 | output_fname ?: fname); |
| 1013 | |
| 1014 | /* Assign new section numbers. */ |
| 1015 | shdr_info[0].idx = 0; |
| 1016 | for (cnt = idx = 1; cnt < shnum; ++cnt) |
| 1017 | if (shdr_info[cnt].idx > 0) |
| 1018 | { |
| 1019 | shdr_info[cnt].idx = idx++; |
| 1020 | |
| 1021 | /* Create a new section. */ |
| 1022 | shdr_info[cnt].newscn = elf_newscn (newelf); |
| 1023 | if (shdr_info[cnt].newscn == NULL) |
| 1024 | error (EXIT_FAILURE, 0, gettext ("while generating output file: %s"), |
| 1025 | elf_errmsg (-1)); |
| 1026 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1027 | elf_assert (elf_ndxscn (shdr_info[cnt].newscn) == shdr_info[cnt].idx); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1028 | |
| 1029 | /* Add this name to the section header string table. */ |
| 1030 | shdr_info[cnt].se = ebl_strtabadd (shst, shdr_info[cnt].name, 0); |
| 1031 | } |
| 1032 | |
| 1033 | /* Test whether we are doing anything at all. */ |
| 1034 | if (cnt == idx) |
| 1035 | /* Nope, all removable sections are already gone. */ |
| 1036 | goto fail_close; |
| 1037 | |
| 1038 | /* Create the reference to the file with the debug info. */ |
| 1039 | if (debug_fname != NULL && !remove_shdrs) |
| 1040 | { |
| 1041 | /* Add the section header string table section name. */ |
| 1042 | shdr_info[cnt].se = ebl_strtabadd (shst, ".gnu_debuglink", 15); |
| 1043 | shdr_info[cnt].idx = idx++; |
| 1044 | |
| 1045 | /* Create the section header. */ |
| 1046 | shdr_info[cnt].shdr.sh_type = SHT_PROGBITS; |
| 1047 | shdr_info[cnt].shdr.sh_flags = 0; |
| 1048 | shdr_info[cnt].shdr.sh_addr = 0; |
| 1049 | shdr_info[cnt].shdr.sh_link = SHN_UNDEF; |
| 1050 | shdr_info[cnt].shdr.sh_info = SHN_UNDEF; |
| 1051 | shdr_info[cnt].shdr.sh_entsize = 0; |
| 1052 | shdr_info[cnt].shdr.sh_addralign = 4; |
| 1053 | /* We set the offset to zero here. Before we write the ELF file the |
| 1054 | field must have the correct value. This is done in the final |
| 1055 | loop over all section. Then we have all the information needed. */ |
| 1056 | shdr_info[cnt].shdr.sh_offset = 0; |
| 1057 | |
| 1058 | /* Create the section. */ |
| 1059 | shdr_info[cnt].newscn = elf_newscn (newelf); |
| 1060 | if (shdr_info[cnt].newscn == NULL) |
| 1061 | error (EXIT_FAILURE, 0, |
| 1062 | gettext ("while create section header section: %s"), |
| 1063 | elf_errmsg (-1)); |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1064 | elf_assert (elf_ndxscn (shdr_info[cnt].newscn) == shdr_info[cnt].idx); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1065 | |
| 1066 | shdr_info[cnt].data = elf_newdata (shdr_info[cnt].newscn); |
| 1067 | if (shdr_info[cnt].data == NULL) |
| 1068 | error (EXIT_FAILURE, 0, gettext ("cannot allocate section data: %s"), |
| 1069 | elf_errmsg (-1)); |
| 1070 | |
| 1071 | char *debug_basename = basename (debug_fname_embed ?: debug_fname); |
| 1072 | off_t crc_offset = strlen (debug_basename) + 1; |
| 1073 | /* Align to 4 byte boundary */ |
| 1074 | crc_offset = ((crc_offset - 1) & ~3) + 4; |
| 1075 | |
| 1076 | shdr_info[cnt].data->d_align = 4; |
| 1077 | shdr_info[cnt].shdr.sh_size = shdr_info[cnt].data->d_size |
| 1078 | = crc_offset + 4; |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1079 | debuglink_buf = xcalloc (1, shdr_info[cnt].data->d_size); |
| 1080 | shdr_info[cnt].data->d_buf = debuglink_buf; |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1081 | |
| 1082 | strcpy (shdr_info[cnt].data->d_buf, debug_basename); |
| 1083 | |
| 1084 | /* Cache this Elf_Data describing the CRC32 word in the section. |
| 1085 | We'll fill this in when we have written the debug file. */ |
| 1086 | debuglink_crc_data = *shdr_info[cnt].data; |
| 1087 | debuglink_crc_data.d_buf = ((char *) debuglink_crc_data.d_buf |
| 1088 | + crc_offset); |
| 1089 | debuglink_crc_data.d_size = 4; |
| 1090 | |
| 1091 | /* One more section done. */ |
| 1092 | ++cnt; |
| 1093 | } |
| 1094 | |
| 1095 | /* Index of the section header table in the shdr_info array. */ |
| 1096 | shdridx = cnt; |
| 1097 | |
| 1098 | /* Add the section header string table section name. */ |
| 1099 | shdr_info[cnt].se = ebl_strtabadd (shst, ".shstrtab", 10); |
| 1100 | shdr_info[cnt].idx = idx; |
| 1101 | |
| 1102 | /* Create the section header. */ |
| 1103 | shdr_info[cnt].shdr.sh_type = SHT_STRTAB; |
| 1104 | shdr_info[cnt].shdr.sh_flags = 0; |
| 1105 | shdr_info[cnt].shdr.sh_addr = 0; |
| 1106 | shdr_info[cnt].shdr.sh_link = SHN_UNDEF; |
| 1107 | shdr_info[cnt].shdr.sh_info = SHN_UNDEF; |
| 1108 | shdr_info[cnt].shdr.sh_entsize = 0; |
| 1109 | /* We set the offset to zero here. Before we write the ELF file the |
| 1110 | field must have the correct value. This is done in the final |
| 1111 | loop over all section. Then we have all the information needed. */ |
| 1112 | shdr_info[cnt].shdr.sh_offset = 0; |
| 1113 | shdr_info[cnt].shdr.sh_addralign = 1; |
| 1114 | |
| 1115 | /* Create the section. */ |
| 1116 | shdr_info[cnt].newscn = elf_newscn (newelf); |
| 1117 | if (shdr_info[cnt].newscn == NULL) |
| 1118 | error (EXIT_FAILURE, 0, |
| 1119 | gettext ("while create section header section: %s"), |
| 1120 | elf_errmsg (-1)); |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1121 | elf_assert (elf_ndxscn (shdr_info[cnt].newscn) == idx); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1122 | |
| 1123 | /* Finalize the string table and fill in the correct indices in the |
| 1124 | section headers. */ |
| 1125 | shstrtab_data = elf_newdata (shdr_info[cnt].newscn); |
| 1126 | if (shstrtab_data == NULL) |
| 1127 | error (EXIT_FAILURE, 0, |
| 1128 | gettext ("while create section header string table: %s"), |
| 1129 | elf_errmsg (-1)); |
| 1130 | ebl_strtabfinalize (shst, shstrtab_data); |
| 1131 | |
| 1132 | /* We have to set the section size. */ |
| 1133 | shdr_info[cnt].shdr.sh_size = shstrtab_data->d_size; |
| 1134 | |
| 1135 | /* Update the section information. */ |
| 1136 | GElf_Off lastoffset = 0; |
| 1137 | for (cnt = 1; cnt <= shdridx; ++cnt) |
| 1138 | if (shdr_info[cnt].idx > 0) |
| 1139 | { |
| 1140 | Elf_Data *newdata; |
| 1141 | |
| 1142 | scn = elf_getscn (newelf, shdr_info[cnt].idx); |
| 1143 | assert (scn != NULL); |
| 1144 | |
| 1145 | /* Update the name. */ |
| 1146 | shdr_info[cnt].shdr.sh_name = ebl_strtaboffset (shdr_info[cnt].se); |
| 1147 | |
| 1148 | /* Update the section header from the input file. Some fields |
| 1149 | might be section indeces which now have to be adjusted. */ |
| 1150 | if (shdr_info[cnt].shdr.sh_link != 0) |
| 1151 | shdr_info[cnt].shdr.sh_link = |
| 1152 | shdr_info[shdr_info[cnt].shdr.sh_link].idx; |
| 1153 | |
| 1154 | if (shdr_info[cnt].shdr.sh_type == SHT_GROUP) |
| 1155 | { |
| 1156 | assert (shdr_info[cnt].data != NULL); |
| 1157 | |
| 1158 | Elf32_Word *grpref = (Elf32_Word *) shdr_info[cnt].data->d_buf; |
| 1159 | for (size_t inner = 0; |
| 1160 | inner < shdr_info[cnt].data->d_size / sizeof (Elf32_Word); |
| 1161 | ++inner) |
| 1162 | grpref[inner] = shdr_info[grpref[inner]].idx; |
| 1163 | } |
| 1164 | |
| 1165 | /* Handle the SHT_REL, SHT_RELA, and SHF_INFO_LINK flag. */ |
| 1166 | if (SH_INFO_LINK_P (&shdr_info[cnt].shdr)) |
| 1167 | shdr_info[cnt].shdr.sh_info = |
| 1168 | shdr_info[shdr_info[cnt].shdr.sh_info].idx; |
| 1169 | |
| 1170 | /* Get the data from the old file if necessary. We already |
| 1171 | created the data for the section header string table. */ |
| 1172 | if (cnt < shnum) |
| 1173 | { |
| 1174 | if (shdr_info[cnt].data == NULL) |
| 1175 | { |
| 1176 | shdr_info[cnt].data = elf_getdata (shdr_info[cnt].scn, NULL); |
| 1177 | if (shdr_info[cnt].data == NULL) |
| 1178 | INTERNAL_ERROR (fname); |
| 1179 | } |
| 1180 | |
| 1181 | /* Set the data. This is done by copying from the old file. */ |
| 1182 | newdata = elf_newdata (scn); |
| 1183 | if (newdata == NULL) |
| 1184 | INTERNAL_ERROR (fname); |
| 1185 | |
| 1186 | /* Copy the structure. */ |
| 1187 | *newdata = *shdr_info[cnt].data; |
| 1188 | |
| 1189 | /* We know the size. */ |
| 1190 | shdr_info[cnt].shdr.sh_size = shdr_info[cnt].data->d_size; |
| 1191 | |
| 1192 | /* We have to adjust symbol tables. The st_shndx member might |
| 1193 | have to be updated. */ |
| 1194 | if (shdr_info[cnt].shdr.sh_type == SHT_DYNSYM |
| 1195 | || shdr_info[cnt].shdr.sh_type == SHT_SYMTAB) |
| 1196 | { |
| 1197 | Elf_Data *versiondata = NULL; |
| 1198 | Elf_Data *shndxdata = NULL; |
| 1199 | |
| 1200 | size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, |
| 1201 | ehdr->e_version); |
| 1202 | |
| 1203 | if (shdr_info[cnt].symtab_idx != 0) |
| 1204 | { |
| 1205 | assert (shdr_info[cnt].shdr.sh_type == SHT_SYMTAB_SHNDX); |
| 1206 | /* This section has extended section information. |
| 1207 | We have to modify that information, too. */ |
| 1208 | shndxdata = elf_getdata (shdr_info[shdr_info[cnt].symtab_idx].scn, |
| 1209 | NULL); |
| 1210 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1211 | elf_assert ((versiondata->d_size / sizeof (Elf32_Word)) |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1212 | >= shdr_info[cnt].data->d_size / elsize); |
| 1213 | } |
| 1214 | |
| 1215 | if (shdr_info[cnt].version_idx != 0) |
| 1216 | { |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1217 | elf_assert (shdr_info[cnt].shdr.sh_type == SHT_DYNSYM); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1218 | /* This section has associated version |
| 1219 | information. We have to modify that |
| 1220 | information, too. */ |
| 1221 | versiondata = elf_getdata (shdr_info[shdr_info[cnt].version_idx].scn, |
| 1222 | NULL); |
| 1223 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1224 | elf_assert ((versiondata->d_size / sizeof (GElf_Versym)) |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1225 | >= shdr_info[cnt].data->d_size / elsize); |
| 1226 | } |
| 1227 | |
| 1228 | shdr_info[cnt].newsymidx |
| 1229 | = (Elf32_Word *) xcalloc (shdr_info[cnt].data->d_size |
| 1230 | / elsize, sizeof (Elf32_Word)); |
| 1231 | |
| 1232 | bool last_was_local = true; |
| 1233 | size_t destidx; |
| 1234 | size_t inner; |
| 1235 | for (destidx = inner = 1; |
| 1236 | inner < shdr_info[cnt].data->d_size / elsize; |
| 1237 | ++inner) |
| 1238 | { |
| 1239 | Elf32_Word sec; |
| 1240 | GElf_Sym sym_mem; |
| 1241 | Elf32_Word xshndx; |
| 1242 | GElf_Sym *sym = gelf_getsymshndx (shdr_info[cnt].data, |
| 1243 | shndxdata, inner, |
| 1244 | &sym_mem, &xshndx); |
| 1245 | if (sym == NULL) |
| 1246 | INTERNAL_ERROR (fname); |
| 1247 | |
| 1248 | if (sym->st_shndx == SHN_UNDEF |
| 1249 | || (sym->st_shndx >= shnum |
| 1250 | && sym->st_shndx != SHN_XINDEX)) |
| 1251 | { |
| 1252 | /* This is no section index, leave it alone |
| 1253 | unless it is moved. */ |
| 1254 | if (destidx != inner |
| 1255 | && gelf_update_symshndx (shdr_info[cnt].data, |
| 1256 | shndxdata, |
| 1257 | destidx, sym, |
| 1258 | xshndx) == 0) |
| 1259 | INTERNAL_ERROR (fname); |
| 1260 | |
| 1261 | shdr_info[cnt].newsymidx[inner] = destidx++; |
| 1262 | |
| 1263 | if (last_was_local |
| 1264 | && GELF_ST_BIND (sym->st_info) != STB_LOCAL) |
| 1265 | { |
| 1266 | last_was_local = false; |
| 1267 | shdr_info[cnt].shdr.sh_info = destidx - 1; |
| 1268 | } |
| 1269 | |
| 1270 | continue; |
| 1271 | } |
| 1272 | |
| 1273 | /* Get the full section index, if necessary from the |
| 1274 | XINDEX table. */ |
| 1275 | if (sym->st_shndx != SHN_XINDEX) |
| 1276 | sec = shdr_info[sym->st_shndx].idx; |
| 1277 | else |
| 1278 | { |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1279 | elf_assert (shndxdata != NULL); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1280 | |
| 1281 | sec = shdr_info[xshndx].idx; |
| 1282 | } |
| 1283 | |
| 1284 | if (sec != 0) |
| 1285 | { |
| 1286 | GElf_Section nshndx; |
| 1287 | Elf32_Word nxshndx; |
| 1288 | |
| 1289 | if (sec < SHN_LORESERVE) |
| 1290 | { |
| 1291 | nshndx = sec; |
| 1292 | nxshndx = 0; |
| 1293 | } |
| 1294 | else |
| 1295 | { |
| 1296 | nshndx = SHN_XINDEX; |
| 1297 | nxshndx = sec; |
| 1298 | } |
| 1299 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1300 | elf_assert (sec < SHN_LORESERVE || shndxdata != NULL); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1301 | |
| 1302 | if ((inner != destidx || nshndx != sym->st_shndx |
| 1303 | || (shndxdata != NULL && nxshndx != xshndx)) |
| 1304 | && (sym->st_shndx = nshndx, |
| 1305 | gelf_update_symshndx (shdr_info[cnt].data, |
| 1306 | shndxdata, |
| 1307 | destidx, sym, |
| 1308 | nxshndx) == 0)) |
| 1309 | INTERNAL_ERROR (fname); |
| 1310 | |
| 1311 | shdr_info[cnt].newsymidx[inner] = destidx++; |
| 1312 | |
| 1313 | if (last_was_local |
| 1314 | && GELF_ST_BIND (sym->st_info) != STB_LOCAL) |
| 1315 | { |
| 1316 | last_was_local = false; |
| 1317 | shdr_info[cnt].shdr.sh_info = destidx - 1; |
| 1318 | } |
| 1319 | } |
| 1320 | else if (debug_fname == NULL |
| 1321 | || shdr_info[cnt].debug_data == NULL) |
| 1322 | /* This is a section or group signature symbol |
| 1323 | for a section which has been removed. */ |
| 1324 | { |
| 1325 | size_t sidx = (sym->st_shndx != SHN_XINDEX |
| 1326 | ? sym->st_shndx : xshndx); |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1327 | elf_assert (GELF_ST_TYPE (sym->st_info) == STT_SECTION |
| 1328 | || ((shdr_info[sidx].shdr.sh_type |
| 1329 | == SHT_GROUP) |
| 1330 | && (shdr_info[sidx].shdr.sh_info |
| 1331 | == inner))); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1332 | } |
| 1333 | } |
| 1334 | |
| 1335 | if (destidx != inner) |
| 1336 | { |
| 1337 | /* The size of the symbol table changed. */ |
| 1338 | shdr_info[cnt].shdr.sh_size = newdata->d_size |
| 1339 | = destidx * elsize; |
| 1340 | any_symtab_changes = true; |
| 1341 | } |
| 1342 | else |
| 1343 | { |
| 1344 | /* The symbol table didn't really change. */ |
| 1345 | free (shdr_info[cnt].newsymidx); |
| 1346 | shdr_info[cnt].newsymidx = NULL; |
| 1347 | } |
| 1348 | } |
| 1349 | } |
| 1350 | |
| 1351 | /* If we have to, compute the offset of the section. */ |
| 1352 | if (shdr_info[cnt].shdr.sh_offset == 0) |
| 1353 | shdr_info[cnt].shdr.sh_offset |
| 1354 | = ((lastoffset + shdr_info[cnt].shdr.sh_addralign - 1) |
| 1355 | & ~((GElf_Off) (shdr_info[cnt].shdr.sh_addralign - 1))); |
| 1356 | |
| 1357 | /* Set the section header in the new file. */ |
| 1358 | if (unlikely (gelf_update_shdr (scn, &shdr_info[cnt].shdr) == 0)) |
| 1359 | /* There cannot be any overflows. */ |
| 1360 | INTERNAL_ERROR (fname); |
| 1361 | |
| 1362 | /* Remember the last section written so far. */ |
| 1363 | GElf_Off filesz = (shdr_info[cnt].shdr.sh_type != SHT_NOBITS |
| 1364 | ? shdr_info[cnt].shdr.sh_size : 0); |
| 1365 | if (lastoffset < shdr_info[cnt].shdr.sh_offset + filesz) |
| 1366 | lastoffset = shdr_info[cnt].shdr.sh_offset + filesz; |
| 1367 | } |
| 1368 | |
| 1369 | /* Adjust symbol references if symbol tables changed. */ |
| 1370 | if (any_symtab_changes) |
| 1371 | /* Find all relocation sections which use this symbol table. */ |
| 1372 | for (cnt = 1; cnt <= shdridx; ++cnt) |
| 1373 | { |
| 1374 | /* Update section headers when the data size has changed. |
| 1375 | We also update the SHT_NOBITS section in the debug |
| 1376 | file so that the section headers match in sh_size. */ |
| 1377 | inline void update_section_size (const Elf_Data *newdata) |
| 1378 | { |
| 1379 | GElf_Shdr shdr_mem; |
| 1380 | GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); |
| 1381 | shdr->sh_size = newdata->d_size; |
| 1382 | (void) gelf_update_shdr (scn, shdr); |
| 1383 | if (debugelf != NULL) |
| 1384 | { |
| 1385 | /* libelf will use d_size to set sh_size. */ |
| 1386 | Elf_Data *debugdata = elf_getdata (elf_getscn (debugelf, |
| 1387 | cnt), NULL); |
| 1388 | debugdata->d_size = newdata->d_size; |
| 1389 | } |
| 1390 | } |
| 1391 | |
| 1392 | if (shdr_info[cnt].idx == 0 && debug_fname == NULL) |
| 1393 | /* Ignore sections which are discarded. When we are saving a |
| 1394 | relocation section in a separate debug file, we must fix up |
| 1395 | the symbol table references. */ |
| 1396 | continue; |
| 1397 | |
| 1398 | const Elf32_Word symtabidx = shdr_info[cnt].old_sh_link; |
| 1399 | const Elf32_Word *const newsymidx = shdr_info[symtabidx].newsymidx; |
| 1400 | switch (shdr_info[cnt].shdr.sh_type) |
| 1401 | { |
| 1402 | inline bool no_symtab_updates (void) |
| 1403 | { |
| 1404 | /* If the symbol table hasn't changed, do not do anything. */ |
| 1405 | if (shdr_info[symtabidx].newsymidx == NULL) |
| 1406 | return true; |
| 1407 | |
| 1408 | /* If the symbol table is not discarded, but additionally |
| 1409 | duplicated in the separate debug file and this section |
| 1410 | is discarded, don't adjust anything. */ |
| 1411 | return (shdr_info[cnt].idx == 0 |
| 1412 | && shdr_info[symtabidx].debug_data != NULL); |
| 1413 | } |
| 1414 | |
| 1415 | case SHT_REL: |
| 1416 | case SHT_RELA: |
| 1417 | if (no_symtab_updates ()) |
| 1418 | break; |
| 1419 | |
| 1420 | Elf_Data *d = elf_getdata (shdr_info[cnt].idx == 0 |
| 1421 | ? elf_getscn (debugelf, cnt) |
| 1422 | : elf_getscn (newelf, |
| 1423 | shdr_info[cnt].idx), |
| 1424 | NULL); |
| 1425 | assert (d != NULL); |
| 1426 | size_t nrels = (shdr_info[cnt].shdr.sh_size |
| 1427 | / shdr_info[cnt].shdr.sh_entsize); |
| 1428 | |
| 1429 | if (shdr_info[cnt].shdr.sh_type == SHT_REL) |
| 1430 | for (size_t relidx = 0; relidx < nrels; ++relidx) |
| 1431 | { |
| 1432 | GElf_Rel rel_mem; |
| 1433 | if (gelf_getrel (d, relidx, &rel_mem) == NULL) |
| 1434 | INTERNAL_ERROR (fname); |
| 1435 | |
| 1436 | size_t symidx = GELF_R_SYM (rel_mem.r_info); |
| 1437 | if (newsymidx[symidx] != symidx) |
| 1438 | { |
| 1439 | rel_mem.r_info |
| 1440 | = GELF_R_INFO (newsymidx[symidx], |
| 1441 | GELF_R_TYPE (rel_mem.r_info)); |
| 1442 | |
| 1443 | if (gelf_update_rel (d, relidx, &rel_mem) == 0) |
| 1444 | INTERNAL_ERROR (fname); |
| 1445 | } |
| 1446 | } |
| 1447 | else |
| 1448 | for (size_t relidx = 0; relidx < nrels; ++relidx) |
| 1449 | { |
| 1450 | GElf_Rela rel_mem; |
| 1451 | if (gelf_getrela (d, relidx, &rel_mem) == NULL) |
| 1452 | INTERNAL_ERROR (fname); |
| 1453 | |
| 1454 | size_t symidx = GELF_R_SYM (rel_mem.r_info); |
| 1455 | if (newsymidx[symidx] != symidx) |
| 1456 | { |
| 1457 | rel_mem.r_info |
| 1458 | = GELF_R_INFO (newsymidx[symidx], |
| 1459 | GELF_R_TYPE (rel_mem.r_info)); |
| 1460 | |
| 1461 | if (gelf_update_rela (d, relidx, &rel_mem) == 0) |
| 1462 | INTERNAL_ERROR (fname); |
| 1463 | } |
| 1464 | } |
| 1465 | break; |
| 1466 | |
| 1467 | case SHT_HASH: |
| 1468 | if (no_symtab_updates ()) |
| 1469 | break; |
| 1470 | |
| 1471 | /* We have to recompute the hash table. */ |
| 1472 | |
| 1473 | assert (shdr_info[cnt].idx > 0); |
| 1474 | |
| 1475 | /* The hash section in the new file. */ |
| 1476 | scn = elf_getscn (newelf, shdr_info[cnt].idx); |
| 1477 | |
| 1478 | /* The symbol table data. */ |
| 1479 | Elf_Data *symd = elf_getdata (elf_getscn (newelf, |
| 1480 | shdr_info[symtabidx].idx), |
| 1481 | NULL); |
| 1482 | assert (symd != NULL); |
| 1483 | |
| 1484 | /* The hash table data. */ |
| 1485 | Elf_Data *hashd = elf_getdata (scn, NULL); |
| 1486 | assert (hashd != NULL); |
| 1487 | |
| 1488 | if (shdr_info[cnt].shdr.sh_entsize == sizeof (Elf32_Word)) |
| 1489 | { |
| 1490 | /* Sane arches first. */ |
| 1491 | Elf32_Word *bucket = (Elf32_Word *) hashd->d_buf; |
| 1492 | |
| 1493 | size_t strshndx = shdr_info[symtabidx].old_sh_link; |
| 1494 | size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, |
| 1495 | ehdr->e_version); |
| 1496 | |
| 1497 | /* Adjust the nchain value. The symbol table size |
| 1498 | changed. We keep the same size for the bucket array. */ |
| 1499 | bucket[1] = symd->d_size / elsize; |
| 1500 | Elf32_Word nbucket = bucket[0]; |
| 1501 | bucket += 2; |
| 1502 | Elf32_Word *chain = bucket + nbucket; |
| 1503 | |
| 1504 | /* New size of the section. */ |
| 1505 | hashd->d_size = ((2 + symd->d_size / elsize + nbucket) |
| 1506 | * sizeof (Elf32_Word)); |
| 1507 | update_section_size (hashd); |
| 1508 | |
| 1509 | /* Clear the arrays. */ |
| 1510 | memset (bucket, '\0', |
| 1511 | (symd->d_size / elsize + nbucket) |
| 1512 | * sizeof (Elf32_Word)); |
| 1513 | |
| 1514 | for (size_t inner = shdr_info[symtabidx].shdr.sh_info; |
| 1515 | inner < symd->d_size / elsize; ++inner) |
| 1516 | { |
| 1517 | GElf_Sym sym_mem; |
| 1518 | GElf_Sym *sym = gelf_getsym (symd, inner, &sym_mem); |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1519 | elf_assert (sym != NULL); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1520 | |
| 1521 | const char *name = elf_strptr (elf, strshndx, |
| 1522 | sym->st_name); |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1523 | elf_assert (name != NULL); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1524 | size_t hidx = elf_hash (name) % nbucket; |
| 1525 | |
| 1526 | if (bucket[hidx] == 0) |
| 1527 | bucket[hidx] = inner; |
| 1528 | else |
| 1529 | { |
| 1530 | hidx = bucket[hidx]; |
| 1531 | |
| 1532 | while (chain[hidx] != 0) |
| 1533 | hidx = chain[hidx]; |
| 1534 | |
| 1535 | chain[hidx] = inner; |
| 1536 | } |
| 1537 | } |
| 1538 | } |
| 1539 | else |
| 1540 | { |
| 1541 | /* Alpha and S390 64-bit use 64-bit SHT_HASH entries. */ |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1542 | elf_assert (shdr_info[cnt].shdr.sh_entsize |
| 1543 | == sizeof (Elf64_Xword)); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1544 | |
| 1545 | Elf64_Xword *bucket = (Elf64_Xword *) hashd->d_buf; |
| 1546 | |
| 1547 | size_t strshndx = shdr_info[symtabidx].old_sh_link; |
| 1548 | size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, |
| 1549 | ehdr->e_version); |
| 1550 | |
| 1551 | /* Adjust the nchain value. The symbol table size |
| 1552 | changed. We keep the same size for the bucket array. */ |
| 1553 | bucket[1] = symd->d_size / elsize; |
| 1554 | Elf64_Xword nbucket = bucket[0]; |
| 1555 | bucket += 2; |
| 1556 | Elf64_Xword *chain = bucket + nbucket; |
| 1557 | |
| 1558 | /* New size of the section. */ |
| 1559 | hashd->d_size = ((2 + symd->d_size / elsize + nbucket) |
| 1560 | * sizeof (Elf64_Xword)); |
| 1561 | update_section_size (hashd); |
| 1562 | |
| 1563 | /* Clear the arrays. */ |
| 1564 | memset (bucket, '\0', |
| 1565 | (symd->d_size / elsize + nbucket) |
| 1566 | * sizeof (Elf64_Xword)); |
| 1567 | |
| 1568 | for (size_t inner = shdr_info[symtabidx].shdr.sh_info; |
| 1569 | inner < symd->d_size / elsize; ++inner) |
| 1570 | { |
| 1571 | GElf_Sym sym_mem; |
| 1572 | GElf_Sym *sym = gelf_getsym (symd, inner, &sym_mem); |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1573 | elf_assert (sym != NULL); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1574 | |
| 1575 | const char *name = elf_strptr (elf, strshndx, |
| 1576 | sym->st_name); |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 1577 | elf_assert (name != NULL); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1578 | size_t hidx = elf_hash (name) % nbucket; |
| 1579 | |
| 1580 | if (bucket[hidx] == 0) |
| 1581 | bucket[hidx] = inner; |
| 1582 | else |
| 1583 | { |
| 1584 | hidx = bucket[hidx]; |
| 1585 | |
| 1586 | while (chain[hidx] != 0) |
| 1587 | hidx = chain[hidx]; |
| 1588 | |
| 1589 | chain[hidx] = inner; |
| 1590 | } |
| 1591 | } |
| 1592 | } |
| 1593 | break; |
| 1594 | |
| 1595 | case SHT_GNU_versym: |
| 1596 | /* If the symbol table changed we have to adjust the entries. */ |
| 1597 | if (no_symtab_updates ()) |
| 1598 | break; |
| 1599 | |
| 1600 | assert (shdr_info[cnt].idx > 0); |
| 1601 | |
| 1602 | /* The symbol version section in the new file. */ |
| 1603 | scn = elf_getscn (newelf, shdr_info[cnt].idx); |
| 1604 | |
| 1605 | /* The symbol table data. */ |
| 1606 | symd = elf_getdata (elf_getscn (newelf, shdr_info[symtabidx].idx), |
| 1607 | NULL); |
| 1608 | assert (symd != NULL); |
| 1609 | |
| 1610 | /* The version symbol data. */ |
| 1611 | Elf_Data *verd = elf_getdata (scn, NULL); |
| 1612 | assert (verd != NULL); |
| 1613 | |
| 1614 | /* The symbol version array. */ |
| 1615 | GElf_Half *verstab = (GElf_Half *) verd->d_buf; |
| 1616 | |
| 1617 | /* Walk through the list and */ |
| 1618 | size_t elsize = gelf_fsize (elf, verd->d_type, 1, |
| 1619 | ehdr->e_version); |
| 1620 | for (size_t inner = 1; inner < verd->d_size / elsize; ++inner) |
| 1621 | if (newsymidx[inner] != 0) |
| 1622 | /* Overwriting the same array works since the |
| 1623 | reordering can only move entries to lower indices |
| 1624 | in the array. */ |
| 1625 | verstab[newsymidx[inner]] = verstab[inner]; |
| 1626 | |
| 1627 | /* New size of the section. */ |
| 1628 | verd->d_size = gelf_fsize (newelf, verd->d_type, |
| 1629 | symd->d_size |
| 1630 | / gelf_fsize (elf, symd->d_type, 1, |
| 1631 | ehdr->e_version), |
| 1632 | ehdr->e_version); |
| 1633 | update_section_size (verd); |
| 1634 | break; |
| 1635 | |
| 1636 | case SHT_GROUP: |
| 1637 | if (no_symtab_updates ()) |
| 1638 | break; |
| 1639 | |
| 1640 | /* Yes, the symbol table changed. |
| 1641 | Update the section header of the section group. */ |
| 1642 | scn = elf_getscn (newelf, shdr_info[cnt].idx); |
| 1643 | GElf_Shdr shdr_mem; |
| 1644 | GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); |
| 1645 | assert (shdr != NULL); |
| 1646 | |
| 1647 | shdr->sh_info = newsymidx[shdr->sh_info]; |
| 1648 | |
| 1649 | (void) gelf_update_shdr (scn, shdr); |
| 1650 | break; |
| 1651 | } |
| 1652 | } |
| 1653 | |
| 1654 | /* Remove any relocations between debug sections in ET_REL |
| 1655 | for the debug file when requested. These relocations are always |
| 1656 | zero based between the unallocated sections. */ |
| 1657 | if (debug_fname != NULL && reloc_debug && ehdr->e_type == ET_REL) |
| 1658 | { |
| 1659 | scn = NULL; |
| 1660 | cnt = 0; |
| 1661 | while ((scn = elf_nextscn (debugelf, scn)) != NULL) |
| 1662 | { |
| 1663 | cnt++; |
| 1664 | /* We need the actual section and header from the debugelf |
| 1665 | not just the cached original in shdr_info because we |
| 1666 | might want to change the size. */ |
| 1667 | GElf_Shdr shdr_mem; |
| 1668 | GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); |
| 1669 | if (shdr->sh_type == SHT_REL || shdr->sh_type == SHT_RELA) |
| 1670 | { |
| 1671 | /* Make sure that this relocation section points to a |
| 1672 | section to relocate with contents, that isn't |
| 1673 | allocated and that is a debug section. */ |
| 1674 | Elf_Scn *tscn = elf_getscn (debugelf, shdr->sh_info); |
| 1675 | GElf_Shdr tshdr_mem; |
| 1676 | GElf_Shdr *tshdr = gelf_getshdr (tscn, &tshdr_mem); |
| 1677 | if (tshdr->sh_type == SHT_NOBITS |
| 1678 | || tshdr->sh_size == 0 |
| 1679 | || (tshdr->sh_flags & SHF_ALLOC) != 0) |
| 1680 | continue; |
| 1681 | |
| 1682 | const char *tname = elf_strptr (debugelf, shstrndx, |
| 1683 | tshdr->sh_name); |
| 1684 | if (! tname || ! ebl_debugscn_p (ebl, tname)) |
| 1685 | continue; |
| 1686 | |
| 1687 | /* OK, lets relocate all trivial cross debug section |
| 1688 | relocations. */ |
| 1689 | Elf_Data *reldata = elf_getdata (scn, NULL); |
| 1690 | /* We actually wanted the rawdata, but since we already |
| 1691 | accessed it earlier as elf_getdata () that won't |
| 1692 | work. But debug sections are all ELF_T_BYTE, so it |
| 1693 | doesn't really matter. */ |
| 1694 | Elf_Data *tdata = elf_getdata (tscn, NULL); |
| 1695 | if (tdata->d_type != ELF_T_BYTE) |
| 1696 | INTERNAL_ERROR (fname); |
| 1697 | |
| 1698 | /* Pick up the symbol table and shndx table to |
| 1699 | resolve relocation symbol indexes. */ |
| 1700 | Elf64_Word symt = shdr->sh_link; |
| 1701 | Elf_Data *symdata, *xndxdata; |
| 1702 | symdata = (shdr_info[symt].debug_data |
| 1703 | ?: shdr_info[symt].data); |
| 1704 | xndxdata = (shdr_info[shdr_info[symt].symtab_idx].debug_data |
| 1705 | ?: shdr_info[shdr_info[symt].symtab_idx].data); |
| 1706 | |
| 1707 | /* Apply one relocation. Returns true when trivial |
| 1708 | relocation actually done. */ |
| 1709 | bool relocate (GElf_Addr offset, const GElf_Sxword addend, |
| 1710 | bool is_rela, int rtype, int symndx) |
| 1711 | { |
| 1712 | /* R_*_NONE relocs can always just be removed. */ |
| 1713 | if (rtype == 0) |
| 1714 | return true; |
| 1715 | |
| 1716 | /* We only do simple absolute relocations. */ |
| 1717 | Elf_Type type = ebl_reloc_simple_type (ebl, rtype); |
| 1718 | if (type == ELF_T_NUM) |
| 1719 | return false; |
| 1720 | |
| 1721 | /* These are the types we can relocate. */ |
| 1722 | #define TYPES DO_TYPE (BYTE, Byte); DO_TYPE (HALF, Half); \ |
| 1723 | DO_TYPE (WORD, Word); DO_TYPE (SWORD, Sword); \ |
| 1724 | DO_TYPE (XWORD, Xword); DO_TYPE (SXWORD, Sxword) |
| 1725 | |
| 1726 | /* And only for relocations against other debug sections. */ |
| 1727 | GElf_Sym sym_mem; |
| 1728 | Elf32_Word xndx; |
| 1729 | GElf_Sym *sym = gelf_getsymshndx (symdata, xndxdata, |
| 1730 | symndx, &sym_mem, |
| 1731 | &xndx); |
| 1732 | Elf32_Word sec = (sym->st_shndx == SHN_XINDEX |
| 1733 | ? xndx : sym->st_shndx); |
| 1734 | if (ebl_debugscn_p (ebl, shdr_info[sec].name)) |
| 1735 | { |
| 1736 | size_t size; |
| 1737 | |
| 1738 | #define DO_TYPE(NAME, Name) GElf_##Name Name; |
| 1739 | union { TYPES; } tmpbuf; |
| 1740 | #undef DO_TYPE |
| 1741 | |
| 1742 | switch (type) |
| 1743 | { |
| 1744 | #define DO_TYPE(NAME, Name) \ |
| 1745 | case ELF_T_##NAME: \ |
| 1746 | size = sizeof (GElf_##Name); \ |
| 1747 | tmpbuf.Name = 0; \ |
| 1748 | break; |
| 1749 | TYPES; |
| 1750 | #undef DO_TYPE |
| 1751 | default: |
| 1752 | return false; |
| 1753 | } |
| 1754 | |
| 1755 | if (offset > tdata->d_size |
| 1756 | || tdata->d_size - offset < size) |
| 1757 | error (0, 0, gettext ("bad relocation")); |
| 1758 | |
| 1759 | /* When the symbol value is zero then for SHT_REL |
| 1760 | sections this is all that needs to be checked. |
| 1761 | The addend is contained in the original data at |
| 1762 | the offset already. So if the (section) symbol |
| 1763 | address is zero and the given addend is zero |
| 1764 | just remove the relocation, it isn't needed |
| 1765 | anymore. */ |
| 1766 | if (addend == 0 && sym->st_value == 0) |
| 1767 | return true; |
| 1768 | |
| 1769 | Elf_Data tmpdata = |
| 1770 | { |
| 1771 | .d_type = type, |
| 1772 | .d_buf = &tmpbuf, |
| 1773 | .d_size = size, |
| 1774 | .d_version = EV_CURRENT, |
| 1775 | }; |
| 1776 | Elf_Data rdata = |
| 1777 | { |
| 1778 | .d_type = type, |
| 1779 | .d_buf = tdata->d_buf + offset, |
| 1780 | .d_size = size, |
| 1781 | .d_version = EV_CURRENT, |
| 1782 | }; |
| 1783 | |
| 1784 | GElf_Addr value = sym->st_value; |
| 1785 | if (is_rela) |
| 1786 | { |
| 1787 | /* For SHT_RELA sections we just take the |
| 1788 | given addend and add it to the value. */ |
| 1789 | value += addend; |
| 1790 | } |
| 1791 | else |
| 1792 | { |
| 1793 | /* For SHT_REL sections we have to peek at |
| 1794 | what is already in the section at the given |
| 1795 | offset to get the addend. */ |
| 1796 | Elf_Data *d = gelf_xlatetom (debugelf, &tmpdata, |
| 1797 | &rdata, |
| 1798 | ehdr->e_ident[EI_DATA]); |
| 1799 | if (d == NULL) |
| 1800 | INTERNAL_ERROR (fname); |
| 1801 | assert (d == &tmpdata); |
| 1802 | } |
| 1803 | |
| 1804 | switch (type) |
| 1805 | { |
| 1806 | #define DO_TYPE(NAME, Name) \ |
| 1807 | case ELF_T_##NAME: \ |
| 1808 | tmpbuf.Name += (GElf_##Name) value; \ |
| 1809 | break; |
| 1810 | TYPES; |
| 1811 | #undef DO_TYPE |
| 1812 | default: |
| 1813 | abort (); |
| 1814 | } |
| 1815 | |
| 1816 | /* Now finally put in the new value. */ |
| 1817 | Elf_Data *s = gelf_xlatetof (debugelf, &rdata, |
| 1818 | &tmpdata, |
| 1819 | ehdr->e_ident[EI_DATA]); |
| 1820 | if (s == NULL) |
| 1821 | INTERNAL_ERROR (fname); |
| 1822 | assert (s == &rdata); |
| 1823 | |
| 1824 | return true; |
| 1825 | } |
| 1826 | return false; |
| 1827 | } |
| 1828 | |
| 1829 | size_t nrels = shdr->sh_size / shdr->sh_entsize; |
| 1830 | size_t next = 0; |
| 1831 | if (shdr->sh_type == SHT_REL) |
| 1832 | for (size_t relidx = 0; relidx < nrels; ++relidx) |
| 1833 | { |
| 1834 | GElf_Rel rel_mem; |
| 1835 | GElf_Rel *r = gelf_getrel (reldata, relidx, &rel_mem); |
| 1836 | if (! relocate (r->r_offset, 0, false, |
| 1837 | GELF_R_TYPE (r->r_info), |
| 1838 | GELF_R_SYM (r->r_info))) |
| 1839 | { |
| 1840 | if (relidx != next) |
| 1841 | gelf_update_rel (reldata, next, r); |
| 1842 | ++next; |
| 1843 | } |
| 1844 | } |
| 1845 | else |
| 1846 | for (size_t relidx = 0; relidx < nrels; ++relidx) |
| 1847 | { |
| 1848 | GElf_Rela rela_mem; |
| 1849 | GElf_Rela *r = gelf_getrela (reldata, relidx, &rela_mem); |
| 1850 | if (! relocate (r->r_offset, r->r_addend, true, |
| 1851 | GELF_R_TYPE (r->r_info), |
| 1852 | GELF_R_SYM (r->r_info))) |
| 1853 | { |
| 1854 | if (relidx != next) |
| 1855 | gelf_update_rela (reldata, next, r); |
| 1856 | ++next; |
| 1857 | } |
| 1858 | } |
| 1859 | |
| 1860 | nrels = next; |
| 1861 | shdr->sh_size = reldata->d_size = nrels * shdr->sh_entsize; |
| 1862 | gelf_update_shdr (scn, shdr); |
| 1863 | } |
| 1864 | } |
| 1865 | } |
| 1866 | |
| 1867 | /* Now that we have done all adjustments to the data, |
| 1868 | we can actually write out the debug file. */ |
| 1869 | if (debug_fname != NULL) |
| 1870 | { |
| 1871 | /* Finally write the file. */ |
| 1872 | if (unlikely (elf_update (debugelf, ELF_C_WRITE) == -1)) |
| 1873 | { |
| 1874 | error (0, 0, gettext ("while writing '%s': %s"), |
| 1875 | debug_fname, elf_errmsg (-1)); |
| 1876 | result = 1; |
| 1877 | goto fail_close; |
| 1878 | } |
| 1879 | |
| 1880 | /* Create the real output file. First rename, then change the |
| 1881 | mode. */ |
| 1882 | if (rename (tmp_debug_fname, debug_fname) != 0 |
| 1883 | || fchmod (debug_fd, mode) != 0) |
| 1884 | { |
| 1885 | error (0, errno, gettext ("while creating '%s'"), debug_fname); |
| 1886 | result = 1; |
| 1887 | goto fail_close; |
| 1888 | } |
| 1889 | |
| 1890 | /* The temporary file does not exist anymore. */ |
| 1891 | tmp_debug_fname = NULL; |
| 1892 | |
| 1893 | if (!remove_shdrs) |
| 1894 | { |
| 1895 | uint32_t debug_crc; |
| 1896 | Elf_Data debug_crc_data = |
| 1897 | { |
| 1898 | .d_type = ELF_T_WORD, |
| 1899 | .d_buf = &debug_crc, |
| 1900 | .d_size = sizeof (debug_crc), |
| 1901 | .d_version = EV_CURRENT |
| 1902 | }; |
| 1903 | |
| 1904 | /* Compute the checksum which we will add to the executable. */ |
| 1905 | if (crc32_file (debug_fd, &debug_crc) != 0) |
| 1906 | { |
| 1907 | error (0, errno, gettext ("\ |
| 1908 | while computing checksum for debug information")); |
| 1909 | unlink (debug_fname); |
| 1910 | result = 1; |
| 1911 | goto fail_close; |
| 1912 | } |
| 1913 | |
| 1914 | /* Store it in the debuglink section data. */ |
| 1915 | if (unlikely (gelf_xlatetof (newelf, &debuglink_crc_data, |
| 1916 | &debug_crc_data, ehdr->e_ident[EI_DATA]) |
| 1917 | != &debuglink_crc_data)) |
| 1918 | INTERNAL_ERROR (fname); |
| 1919 | } |
| 1920 | } |
| 1921 | |
| 1922 | /* Finally finish the ELF header. Fill in the fields not handled by |
| 1923 | libelf from the old file. */ |
| 1924 | newehdr = gelf_getehdr (newelf, &newehdr_mem); |
| 1925 | if (newehdr == NULL) |
| 1926 | INTERNAL_ERROR (fname); |
| 1927 | |
| 1928 | memcpy (newehdr->e_ident, ehdr->e_ident, EI_NIDENT); |
| 1929 | newehdr->e_type = ehdr->e_type; |
| 1930 | newehdr->e_machine = ehdr->e_machine; |
| 1931 | newehdr->e_version = ehdr->e_version; |
| 1932 | newehdr->e_entry = ehdr->e_entry; |
| 1933 | newehdr->e_flags = ehdr->e_flags; |
| 1934 | newehdr->e_phoff = ehdr->e_phoff; |
| 1935 | |
| 1936 | /* We need to position the section header table. */ |
| 1937 | const size_t offsize = gelf_fsize (elf, ELF_T_OFF, 1, EV_CURRENT); |
| 1938 | newehdr->e_shoff = ((shdr_info[shdridx].shdr.sh_offset |
| 1939 | + shdr_info[shdridx].shdr.sh_size + offsize - 1) |
| 1940 | & ~((GElf_Off) (offsize - 1))); |
| 1941 | newehdr->e_shentsize = gelf_fsize (elf, ELF_T_SHDR, 1, EV_CURRENT); |
| 1942 | |
| 1943 | /* The new section header string table index. */ |
| 1944 | if (likely (idx < SHN_HIRESERVE) && likely (idx != SHN_XINDEX)) |
| 1945 | newehdr->e_shstrndx = idx; |
| 1946 | else |
| 1947 | { |
| 1948 | /* The index does not fit in the ELF header field. */ |
| 1949 | shdr_info[0].scn = elf_getscn (elf, 0); |
| 1950 | |
| 1951 | if (gelf_getshdr (shdr_info[0].scn, &shdr_info[0].shdr) == NULL) |
| 1952 | INTERNAL_ERROR (fname); |
| 1953 | |
| 1954 | shdr_info[0].shdr.sh_link = idx; |
| 1955 | (void) gelf_update_shdr (shdr_info[0].scn, &shdr_info[0].shdr); |
| 1956 | |
| 1957 | newehdr->e_shstrndx = SHN_XINDEX; |
| 1958 | } |
| 1959 | |
| 1960 | if (gelf_update_ehdr (newelf, newehdr) == 0) |
| 1961 | { |
| 1962 | error (0, 0, gettext ("%s: error while creating ELF header: %s"), |
| 1963 | fname, elf_errmsg (-1)); |
| 1964 | return 1; |
| 1965 | } |
| 1966 | |
| 1967 | /* We have everything from the old file. */ |
| 1968 | if (elf_cntl (elf, ELF_C_FDDONE) != 0) |
| 1969 | { |
| 1970 | error (0, 0, gettext ("%s: error while reading the file: %s"), |
| 1971 | fname, elf_errmsg (-1)); |
| 1972 | return 1; |
| 1973 | } |
| 1974 | |
| 1975 | /* The ELF library better follows our layout when this is not a |
| 1976 | relocatable object file. */ |
| 1977 | elf_flagelf (newelf, ELF_C_SET, |
| 1978 | (ehdr->e_type != ET_REL ? ELF_F_LAYOUT : 0) |
| 1979 | | (permissive ? ELF_F_PERMISSIVE : 0)); |
| 1980 | |
| 1981 | /* Finally write the file. */ |
| 1982 | if (elf_update (newelf, ELF_C_WRITE) == -1) |
| 1983 | { |
| 1984 | error (0, 0, gettext ("while writing '%s': %s"), |
| 1985 | fname, elf_errmsg (-1)); |
| 1986 | result = 1; |
| 1987 | } |
| 1988 | |
| 1989 | if (remove_shdrs) |
| 1990 | { |
| 1991 | /* libelf can't cope without the section headers being properly intact. |
| 1992 | So we just let it write them normally, and then we nuke them later. */ |
| 1993 | |
| 1994 | if (newehdr->e_ident[EI_CLASS] == ELFCLASS32) |
| 1995 | { |
| 1996 | assert (offsetof (Elf32_Ehdr, e_shentsize) + sizeof (Elf32_Half) |
| 1997 | == offsetof (Elf32_Ehdr, e_shnum)); |
| 1998 | assert (offsetof (Elf32_Ehdr, e_shnum) + sizeof (Elf32_Half) |
| 1999 | == offsetof (Elf32_Ehdr, e_shstrndx)); |
| 2000 | const Elf32_Off zero_off = 0; |
| 2001 | const Elf32_Half zero[3] = { 0, 0, SHN_UNDEF }; |
| 2002 | if (pwrite_retry (fd, &zero_off, sizeof zero_off, |
| 2003 | offsetof (Elf32_Ehdr, e_shoff)) != sizeof zero_off |
| 2004 | || (pwrite_retry (fd, zero, sizeof zero, |
| 2005 | offsetof (Elf32_Ehdr, e_shentsize)) |
| 2006 | != sizeof zero) |
| 2007 | || ftruncate64 (fd, shdr_info[shdridx].shdr.sh_offset) < 0) |
| 2008 | { |
| 2009 | error (0, errno, gettext ("while writing '%s'"), |
| 2010 | fname); |
| 2011 | result = 1; |
| 2012 | } |
| 2013 | } |
| 2014 | else |
| 2015 | { |
| 2016 | assert (offsetof (Elf64_Ehdr, e_shentsize) + sizeof (Elf64_Half) |
| 2017 | == offsetof (Elf64_Ehdr, e_shnum)); |
| 2018 | assert (offsetof (Elf64_Ehdr, e_shnum) + sizeof (Elf64_Half) |
| 2019 | == offsetof (Elf64_Ehdr, e_shstrndx)); |
| 2020 | const Elf64_Off zero_off = 0; |
| 2021 | const Elf64_Half zero[3] = { 0, 0, SHN_UNDEF }; |
| 2022 | if (pwrite_retry (fd, &zero_off, sizeof zero_off, |
| 2023 | offsetof (Elf64_Ehdr, e_shoff)) != sizeof zero_off |
| 2024 | || (pwrite_retry (fd, zero, sizeof zero, |
| 2025 | offsetof (Elf64_Ehdr, e_shentsize)) |
| 2026 | != sizeof zero) |
| 2027 | || ftruncate64 (fd, shdr_info[shdridx].shdr.sh_offset) < 0) |
| 2028 | { |
| 2029 | error (0, errno, gettext ("while writing '%s'"), |
| 2030 | fname); |
| 2031 | result = 1; |
| 2032 | } |
| 2033 | } |
| 2034 | } |
| 2035 | |
| 2036 | fail_close: |
| 2037 | if (shdr_info != NULL) |
| 2038 | { |
| 2039 | /* For some sections we might have created an table to map symbol |
| 2040 | table indices. */ |
| 2041 | if (any_symtab_changes) |
| 2042 | for (cnt = 1; cnt <= shdridx; ++cnt) |
| 2043 | { |
| 2044 | free (shdr_info[cnt].newsymidx); |
| 2045 | if (shdr_info[cnt].debug_data != NULL) |
| 2046 | free (shdr_info[cnt].debug_data->d_buf); |
| 2047 | } |
| 2048 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 2049 | /* Free data we allocated for the .gnu_debuglink section. */ |
| 2050 | free (debuglink_buf); |
| 2051 | |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 2052 | /* Free the memory. */ |
| 2053 | if ((shnum + 2) * sizeof (struct shdr_info) > MAX_STACK_ALLOC) |
| 2054 | free (shdr_info); |
| 2055 | } |
| 2056 | |
| 2057 | /* Free other resources. */ |
| 2058 | if (shstrtab_data != NULL) |
| 2059 | free (shstrtab_data->d_buf); |
| 2060 | if (shst != NULL) |
| 2061 | ebl_strtabfree (shst); |
| 2062 | |
| 2063 | /* That was it. Close the descriptors. */ |
| 2064 | if (elf_end (newelf) != 0) |
| 2065 | { |
| 2066 | error (0, 0, gettext ("error while finishing '%s': %s"), fname, |
| 2067 | elf_errmsg (-1)); |
| 2068 | result = 1; |
| 2069 | } |
| 2070 | |
| 2071 | if (debugelf != NULL && elf_end (debugelf) != 0) |
| 2072 | { |
| 2073 | error (0, 0, gettext ("error while finishing '%s': %s"), debug_fname, |
| 2074 | elf_errmsg (-1)); |
| 2075 | result = 1; |
| 2076 | } |
| 2077 | |
| 2078 | fail: |
| 2079 | /* Close the EBL backend. */ |
| 2080 | if (ebl != NULL) |
| 2081 | ebl_closebackend (ebl); |
| 2082 | |
| 2083 | /* Close debug file descriptor, if opened */ |
| 2084 | if (debug_fd >= 0) |
| 2085 | { |
| 2086 | if (tmp_debug_fname != NULL) |
| 2087 | unlink (tmp_debug_fname); |
| 2088 | close (debug_fd); |
| 2089 | } |
| 2090 | |
| 2091 | /* If requested, preserve the timestamp. */ |
| 2092 | if (tvp != NULL) |
| 2093 | { |
| 2094 | if (futimes (fd, tvp) != 0) |
| 2095 | { |
| 2096 | error (0, errno, gettext ("\ |
| 2097 | cannot set access and modification date of '%s'"), |
| 2098 | output_fname ?: fname); |
| 2099 | result = 1; |
| 2100 | } |
| 2101 | } |
| 2102 | |
| 2103 | /* Close the file descriptor if we created a new file. */ |
| 2104 | if (output_fname != NULL) |
| 2105 | close (fd); |
| 2106 | |
| 2107 | return result; |
| 2108 | } |
| 2109 | |
| 2110 | |
| 2111 | static int |
| 2112 | handle_ar (int fd, Elf *elf, const char *prefix, const char *fname, |
| 2113 | struct timeval tvp[2]) |
| 2114 | { |
| 2115 | size_t prefix_len = prefix == NULL ? 0 : strlen (prefix); |
| 2116 | size_t fname_len = strlen (fname) + 1; |
| 2117 | char new_prefix[prefix_len + 1 + fname_len]; |
| 2118 | char *cp = new_prefix; |
| 2119 | |
| 2120 | /* Create the full name of the file. */ |
| 2121 | if (prefix != NULL) |
| 2122 | { |
| 2123 | cp = mempcpy (cp, prefix, prefix_len); |
| 2124 | *cp++ = ':'; |
| 2125 | } |
| 2126 | memcpy (cp, fname, fname_len); |
| 2127 | |
| 2128 | |
| 2129 | /* Process all the files contained in the archive. */ |
| 2130 | Elf *subelf; |
| 2131 | Elf_Cmd cmd = ELF_C_RDWR; |
| 2132 | int result = 0; |
| 2133 | while ((subelf = elf_begin (fd, cmd, elf)) != NULL) |
| 2134 | { |
| 2135 | /* The the header for this element. */ |
| 2136 | Elf_Arhdr *arhdr = elf_getarhdr (subelf); |
| 2137 | |
| 2138 | if (elf_kind (subelf) == ELF_K_ELF) |
| 2139 | result |= handle_elf (fd, subelf, new_prefix, arhdr->ar_name, 0, NULL); |
| 2140 | else if (elf_kind (subelf) == ELF_K_AR) |
| 2141 | result |= handle_ar (fd, subelf, new_prefix, arhdr->ar_name, NULL); |
| 2142 | |
| 2143 | /* Get next archive element. */ |
| 2144 | cmd = elf_next (subelf); |
| 2145 | if (unlikely (elf_end (subelf) != 0)) |
| 2146 | INTERNAL_ERROR (fname); |
| 2147 | } |
| 2148 | |
| 2149 | if (tvp != NULL) |
| 2150 | { |
| 2151 | if (unlikely (futimes (fd, tvp) != 0)) |
| 2152 | { |
| 2153 | error (0, errno, gettext ("\ |
| 2154 | cannot set access and modification date of '%s'"), fname); |
| 2155 | result = 1; |
| 2156 | } |
| 2157 | } |
| 2158 | |
| 2159 | if (unlikely (close (fd) != 0)) |
| 2160 | error (EXIT_FAILURE, errno, gettext ("while closing '%s'"), fname); |
| 2161 | |
| 2162 | return result; |
| 2163 | } |
| 2164 | |
| 2165 | |
| 2166 | #include "debugpred.h" |