1 /* Postprocess module symbol versions 2 * 3 * Copyright 2003 Kai Germaschewski 4 * Copyright 2002-2004 Rusty Russell, IBM Corporation 5 * Copyright 2006-2008 Sam Ravnborg 6 * Based in part on module-init-tools/depmod.c,file2alias 7 * 8 * This software may be used and distributed according to the terms 9 * of the GNU General Public License, incorporated herein by reference. 10 * 11 * Usage: modpost vmlinux module1.o module2.o ... 12 */ 13 14 #define _GNU_SOURCE 15 #include <elf.h> 16 #include <fnmatch.h> 17 #include <stdio.h> 18 #include <ctype.h> 19 #include <string.h> 20 #include <limits.h> 21 #include <stdbool.h> 22 #include <errno.h> 23 24 #include <hash.h> 25 #include <hashtable.h> 26 #include <list.h> 27 #include <xalloc.h> 28 #include "modpost.h" 29 #include "../../include/linux/license.h" 30 31 static bool module_enabled; 32 /* Are we using CONFIG_MODVERSIONS? */ 33 static bool modversions; 34 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 35 static bool all_versions; 36 /* Is CONFIG_BASIC_MODVERSIONS set? */ 37 static bool basic_modversions; 38 /* Is CONFIG_EXTENDED_MODVERSIONS set? */ 39 static bool extended_modversions; 40 /* If we are modposting external module set to 1 */ 41 static bool external_module; 42 /* Only warn about unresolved symbols */ 43 static bool warn_unresolved; 44 45 static int sec_mismatch_count; 46 static bool sec_mismatch_warn_only = true; 47 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */ 48 static bool trim_unused_exports; 49 50 /* ignore missing files */ 51 static bool ignore_missing_files; 52 /* If set to 1, only warn (instead of error) about missing ns imports */ 53 static bool allow_missing_ns_imports; 54 55 static bool error_occurred; 56 57 static bool extra_warn; 58 59 bool target_is_big_endian; 60 bool host_is_big_endian; 61 62 /* 63 * Cut off the warnings when there are too many. This typically occurs when 64 * vmlinux is missing. ('make modules' without building vmlinux.) 65 */ 66 #define MAX_UNRESOLVED_REPORTS 10 67 static unsigned int nr_unresolved; 68 69 /* In kernel, this size is defined in linux/module.h; 70 * here we use Elf_Addr instead of long for covering cross-compile 71 */ 72 73 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) 74 75 void modpost_log(bool is_error, const char *fmt, ...) 76 { 77 va_list arglist; 78 79 if (is_error) { 80 fprintf(stderr, "ERROR: "); 81 error_occurred = true; 82 } else { 83 fprintf(stderr, "WARNING: "); 84 } 85 86 fprintf(stderr, "modpost: "); 87 88 va_start(arglist, fmt); 89 vfprintf(stderr, fmt, arglist); 90 va_end(arglist); 91 } 92 93 static inline bool strends(const char *str, const char *postfix) 94 { 95 if (strlen(str) < strlen(postfix)) 96 return false; 97 98 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; 99 } 100 101 /** 102 * get_basename - return the last part of a pathname. 103 * 104 * @path: path to extract the filename from. 105 */ 106 const char *get_basename(const char *path) 107 { 108 const char *tail = strrchr(path, '/'); 109 110 return tail ? tail + 1 : path; 111 } 112 113 char *read_text_file(const char *filename) 114 { 115 struct stat st; 116 size_t nbytes; 117 int fd; 118 char *buf; 119 120 fd = open(filename, O_RDONLY); 121 if (fd < 0) { 122 perror(filename); 123 exit(1); 124 } 125 126 if (fstat(fd, &st) < 0) { 127 perror(filename); 128 exit(1); 129 } 130 131 buf = xmalloc(st.st_size + 1); 132 133 nbytes = st.st_size; 134 135 while (nbytes) { 136 ssize_t bytes_read; 137 138 bytes_read = read(fd, buf, nbytes); 139 if (bytes_read < 0) { 140 perror(filename); 141 exit(1); 142 } 143 144 nbytes -= bytes_read; 145 } 146 buf[st.st_size] = '\0'; 147 148 close(fd); 149 150 return buf; 151 } 152 153 char *get_line(char **stringp) 154 { 155 char *orig = *stringp, *next; 156 157 /* do not return the unwanted extra line at EOF */ 158 if (!orig || *orig == '\0') 159 return NULL; 160 161 /* don't use strsep here, it is not available everywhere */ 162 next = strchr(orig, '\n'); 163 if (next) 164 *next++ = '\0'; 165 166 *stringp = next; 167 168 return orig; 169 } 170 171 /* A list of all modules we processed */ 172 LIST_HEAD(modules); 173 174 static struct module *find_module(const char *filename, const char *modname) 175 { 176 struct module *mod; 177 178 list_for_each_entry(mod, &modules, list) { 179 if (!strcmp(mod->dump_file, filename) && 180 !strcmp(mod->name, modname)) 181 return mod; 182 } 183 return NULL; 184 } 185 186 static struct module *new_module(const char *name, size_t namelen) 187 { 188 struct module *mod; 189 190 mod = xmalloc(sizeof(*mod) + namelen + 1); 191 memset(mod, 0, sizeof(*mod)); 192 193 INIT_LIST_HEAD(&mod->exported_symbols); 194 INIT_LIST_HEAD(&mod->unresolved_symbols); 195 INIT_LIST_HEAD(&mod->missing_namespaces); 196 INIT_LIST_HEAD(&mod->imported_namespaces); 197 INIT_LIST_HEAD(&mod->aliases); 198 199 memcpy(mod->name, name, namelen); 200 mod->name[namelen] = '\0'; 201 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0); 202 203 /* 204 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE() 205 * is missing, do not check the use for EXPORT_SYMBOL_GPL() because 206 * modpost will exit with an error anyway. 207 */ 208 mod->is_gpl_compatible = true; 209 210 list_add_tail(&mod->list, &modules); 211 212 return mod; 213 } 214 215 struct symbol { 216 struct hlist_node hnode;/* link to hash table */ 217 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */ 218 struct module *module; 219 char *namespace; 220 unsigned int crc; 221 bool crc_valid; 222 bool weak; 223 bool is_func; 224 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ 225 bool used; /* there exists a user of this symbol */ 226 char name[]; 227 }; 228 229 static HASHTABLE_DEFINE(symbol_hashtable, 1U << 10); 230 231 /** 232 * Allocate a new symbols for use in the hash of exported symbols or 233 * the list of unresolved symbols per module 234 **/ 235 static struct symbol *alloc_symbol(const char *name) 236 { 237 struct symbol *s = xmalloc(sizeof(*s) + strlen(name) + 1); 238 239 memset(s, 0, sizeof(*s)); 240 strcpy(s->name, name); 241 242 return s; 243 } 244 245 /* For the hash of exported symbols */ 246 static void hash_add_symbol(struct symbol *sym) 247 { 248 hash_add(symbol_hashtable, &sym->hnode, hash_str(sym->name)); 249 } 250 251 static void sym_add_unresolved(const char *name, struct module *mod, bool weak) 252 { 253 struct symbol *sym; 254 255 sym = alloc_symbol(name); 256 sym->weak = weak; 257 258 list_add_tail(&sym->list, &mod->unresolved_symbols); 259 } 260 261 static struct symbol *sym_find_with_module(const char *name, struct module *mod) 262 { 263 struct symbol *s; 264 265 /* For our purposes, .foo matches foo. PPC64 needs this. */ 266 if (name[0] == '.') 267 name++; 268 269 hash_for_each_possible(symbol_hashtable, s, hnode, hash_str(name)) { 270 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) 271 return s; 272 } 273 return NULL; 274 } 275 276 static struct symbol *find_symbol(const char *name) 277 { 278 return sym_find_with_module(name, NULL); 279 } 280 281 struct namespace_list { 282 struct list_head list; 283 char namespace[]; 284 }; 285 286 static bool contains_namespace(struct list_head *head, const char *namespace) 287 { 288 struct namespace_list *list; 289 290 /* 291 * The default namespace is null string "", which is always implicitly 292 * contained. 293 */ 294 if (!namespace[0]) 295 return true; 296 297 list_for_each_entry(list, head, list) { 298 if (!strcmp(list->namespace, namespace)) 299 return true; 300 } 301 302 return false; 303 } 304 305 static void add_namespace(struct list_head *head, const char *namespace) 306 { 307 struct namespace_list *ns_entry; 308 309 if (!contains_namespace(head, namespace)) { 310 ns_entry = xmalloc(sizeof(*ns_entry) + strlen(namespace) + 1); 311 strcpy(ns_entry->namespace, namespace); 312 list_add_tail(&ns_entry->list, head); 313 } 314 } 315 316 static void *sym_get_data_by_offset(const struct elf_info *info, 317 unsigned int secindex, unsigned long offset) 318 { 319 Elf_Shdr *sechdr = &info->sechdrs[secindex]; 320 321 return (void *)info->hdr + sechdr->sh_offset + offset; 322 } 323 324 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) 325 { 326 return sym_get_data_by_offset(info, get_secindex(info, sym), 327 sym->st_value); 328 } 329 330 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) 331 { 332 return sym_get_data_by_offset(info, info->secindex_strings, 333 sechdr->sh_name); 334 } 335 336 static const char *sec_name(const struct elf_info *info, unsigned int secindex) 337 { 338 /* 339 * If sym->st_shndx is a special section index, there is no 340 * corresponding section header. 341 * Return "" if the index is out of range of info->sechdrs[] array. 342 */ 343 if (secindex >= info->num_sections) 344 return ""; 345 346 return sech_name(info, &info->sechdrs[secindex]); 347 } 348 349 static struct symbol *sym_add_exported(const char *name, struct module *mod, 350 bool gpl_only, const char *namespace) 351 { 352 struct symbol *s = find_symbol(name); 353 354 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { 355 error("%s: '%s' exported twice. Previous export was in %s%s\n", 356 mod->name, name, s->module->name, 357 s->module->is_vmlinux ? "" : ".ko"); 358 } 359 360 s = alloc_symbol(name); 361 s->module = mod; 362 s->is_gpl_only = gpl_only; 363 s->namespace = xstrdup(namespace); 364 list_add_tail(&s->list, &mod->exported_symbols); 365 hash_add_symbol(s); 366 367 return s; 368 } 369 370 static void sym_set_crc(struct symbol *sym, unsigned int crc) 371 { 372 sym->crc = crc; 373 sym->crc_valid = true; 374 } 375 376 static void *grab_file(const char *filename, size_t *size) 377 { 378 struct stat st; 379 void *map = MAP_FAILED; 380 int fd; 381 382 fd = open(filename, O_RDONLY); 383 if (fd < 0) 384 return NULL; 385 if (fstat(fd, &st)) 386 goto failed; 387 388 *size = st.st_size; 389 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 390 391 failed: 392 close(fd); 393 if (map == MAP_FAILED) 394 return NULL; 395 return map; 396 } 397 398 static void release_file(void *file, size_t size) 399 { 400 munmap(file, size); 401 } 402 403 static int parse_elf(struct elf_info *info, const char *filename) 404 { 405 unsigned int i; 406 Elf_Ehdr *hdr; 407 Elf_Shdr *sechdrs; 408 Elf_Sym *sym; 409 const char *secstrings; 410 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 411 412 hdr = grab_file(filename, &info->size); 413 if (!hdr) { 414 if (ignore_missing_files) { 415 fprintf(stderr, "%s: %s (ignored)\n", filename, 416 strerror(errno)); 417 return 0; 418 } 419 perror(filename); 420 exit(1); 421 } 422 info->hdr = hdr; 423 if (info->size < sizeof(*hdr)) { 424 /* file too small, assume this is an empty .o file */ 425 return 0; 426 } 427 /* Is this a valid ELF file? */ 428 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 429 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 430 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 431 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 432 /* Not an ELF file - silently ignore it */ 433 return 0; 434 } 435 436 switch (hdr->e_ident[EI_DATA]) { 437 case ELFDATA2LSB: 438 target_is_big_endian = false; 439 break; 440 case ELFDATA2MSB: 441 target_is_big_endian = true; 442 break; 443 default: 444 fatal("target endian is unknown\n"); 445 } 446 447 /* Fix endianness in ELF header */ 448 hdr->e_type = TO_NATIVE(hdr->e_type); 449 hdr->e_machine = TO_NATIVE(hdr->e_machine); 450 hdr->e_version = TO_NATIVE(hdr->e_version); 451 hdr->e_entry = TO_NATIVE(hdr->e_entry); 452 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 453 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 454 hdr->e_flags = TO_NATIVE(hdr->e_flags); 455 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 456 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 457 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 458 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 459 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 460 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 461 sechdrs = (void *)hdr + hdr->e_shoff; 462 info->sechdrs = sechdrs; 463 464 /* modpost only works for relocatable objects */ 465 if (hdr->e_type != ET_REL) 466 fatal("%s: not relocatable object.", filename); 467 468 /* Check if file offset is correct */ 469 if (hdr->e_shoff > info->size) 470 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", 471 (unsigned long)hdr->e_shoff, filename, info->size); 472 473 if (hdr->e_shnum == SHN_UNDEF) { 474 /* 475 * There are more than 64k sections, 476 * read count from .sh_size. 477 */ 478 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 479 } 480 else { 481 info->num_sections = hdr->e_shnum; 482 } 483 if (hdr->e_shstrndx == SHN_XINDEX) { 484 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 485 } 486 else { 487 info->secindex_strings = hdr->e_shstrndx; 488 } 489 490 /* Fix endianness in section headers */ 491 for (i = 0; i < info->num_sections; i++) { 492 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 493 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 494 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 495 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 496 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 497 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 498 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 499 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 500 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 501 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 502 } 503 /* Find symbol table. */ 504 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 505 for (i = 1; i < info->num_sections; i++) { 506 const char *secname; 507 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 508 509 if (!nobits && sechdrs[i].sh_offset > info->size) 510 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n", 511 filename, (unsigned long)sechdrs[i].sh_offset, 512 sizeof(*hdr)); 513 514 secname = secstrings + sechdrs[i].sh_name; 515 if (strcmp(secname, ".modinfo") == 0) { 516 if (nobits) 517 fatal("%s has NOBITS .modinfo\n", filename); 518 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 519 info->modinfo_len = sechdrs[i].sh_size; 520 } else if (!strcmp(secname, ".export_symbol")) { 521 info->export_symbol_secndx = i; 522 } else if (!strcmp(secname, ".no_trim_symbol")) { 523 info->no_trim_symbol = (void *)hdr + sechdrs[i].sh_offset; 524 info->no_trim_symbol_len = sechdrs[i].sh_size; 525 } 526 527 if (sechdrs[i].sh_type == SHT_SYMTAB) { 528 unsigned int sh_link_idx; 529 symtab_idx = i; 530 info->symtab_start = (void *)hdr + 531 sechdrs[i].sh_offset; 532 info->symtab_stop = (void *)hdr + 533 sechdrs[i].sh_offset + sechdrs[i].sh_size; 534 sh_link_idx = sechdrs[i].sh_link; 535 info->strtab = (void *)hdr + 536 sechdrs[sh_link_idx].sh_offset; 537 } 538 539 /* 32bit section no. table? ("more than 64k sections") */ 540 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 541 symtab_shndx_idx = i; 542 info->symtab_shndx_start = (void *)hdr + 543 sechdrs[i].sh_offset; 544 info->symtab_shndx_stop = (void *)hdr + 545 sechdrs[i].sh_offset + sechdrs[i].sh_size; 546 } 547 } 548 if (!info->symtab_start) 549 fatal("%s has no symtab?\n", filename); 550 551 /* Fix endianness in symbols */ 552 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 553 sym->st_shndx = TO_NATIVE(sym->st_shndx); 554 sym->st_name = TO_NATIVE(sym->st_name); 555 sym->st_value = TO_NATIVE(sym->st_value); 556 sym->st_size = TO_NATIVE(sym->st_size); 557 } 558 559 if (symtab_shndx_idx != ~0U) { 560 Elf32_Word *p; 561 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 562 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 563 filename, sechdrs[symtab_shndx_idx].sh_link, 564 symtab_idx); 565 /* Fix endianness */ 566 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 567 p++) 568 *p = TO_NATIVE(*p); 569 } 570 571 symsearch_init(info); 572 573 return 1; 574 } 575 576 static void parse_elf_finish(struct elf_info *info) 577 { 578 symsearch_finish(info); 579 release_file(info->hdr, info->size); 580 } 581 582 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 583 { 584 /* ignore __this_module, it will be resolved shortly */ 585 if (strcmp(symname, "__this_module") == 0) 586 return 1; 587 /* ignore global offset table */ 588 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 589 return 1; 590 if (info->hdr->e_machine == EM_PPC) 591 /* Special register function linked on all modules during final link of .ko */ 592 if (strstarts(symname, "_restgpr_") || 593 strstarts(symname, "_savegpr_") || 594 strstarts(symname, "_rest32gpr_") || 595 strstarts(symname, "_save32gpr_") || 596 strstarts(symname, "_restvr_") || 597 strstarts(symname, "_savevr_")) 598 return 1; 599 if (info->hdr->e_machine == EM_PPC64) 600 /* Special register function linked on all modules during final link of .ko */ 601 if (strstarts(symname, "_restgpr0_") || 602 strstarts(symname, "_savegpr0_") || 603 strstarts(symname, "_restvr_") || 604 strstarts(symname, "_savevr_") || 605 strcmp(symname, ".TOC.") == 0) 606 return 1; 607 /* Do not ignore this symbol */ 608 return 0; 609 } 610 611 static void handle_symbol(struct module *mod, struct elf_info *info, 612 const Elf_Sym *sym, const char *symname) 613 { 614 switch (sym->st_shndx) { 615 case SHN_COMMON: 616 if (strstarts(symname, "__gnu_lto_")) { 617 /* Should warn here, but modpost runs before the linker */ 618 } else 619 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 620 break; 621 case SHN_UNDEF: 622 /* undefined symbol */ 623 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 624 ELF_ST_BIND(sym->st_info) != STB_WEAK) 625 break; 626 if (ignore_undef_symbol(info, symname)) 627 break; 628 if (info->hdr->e_machine == EM_SPARC || 629 info->hdr->e_machine == EM_SPARCV9) { 630 /* Ignore register directives. */ 631 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 632 break; 633 if (symname[0] == '.') { 634 char *munged = xstrdup(symname); 635 munged[0] = '_'; 636 munged[1] = toupper(munged[1]); 637 symname = munged; 638 } 639 } 640 641 sym_add_unresolved(symname, mod, 642 ELF_ST_BIND(sym->st_info) == STB_WEAK); 643 break; 644 default: 645 if (strcmp(symname, "init_module") == 0) 646 mod->has_init = true; 647 if (strcmp(symname, "cleanup_module") == 0) 648 mod->has_cleanup = true; 649 break; 650 } 651 } 652 653 /** 654 * Parse tag=value strings from .modinfo section 655 **/ 656 static char *next_string(char *string, unsigned long *secsize) 657 { 658 /* Skip non-zero chars */ 659 while (string[0]) { 660 string++; 661 if ((*secsize)-- <= 1) 662 return NULL; 663 } 664 665 /* Skip any zero padding. */ 666 while (!string[0]) { 667 string++; 668 if ((*secsize)-- <= 1) 669 return NULL; 670 } 671 return string; 672 } 673 674 static char *get_next_modinfo(struct elf_info *info, const char *tag, 675 char *prev) 676 { 677 char *p; 678 unsigned int taglen = strlen(tag); 679 char *modinfo = info->modinfo; 680 unsigned long size = info->modinfo_len; 681 682 if (prev) { 683 size -= prev - modinfo; 684 modinfo = next_string(prev, &size); 685 } 686 687 for (p = modinfo; p; p = next_string(p, &size)) { 688 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 689 return p + taglen + 1; 690 } 691 return NULL; 692 } 693 694 static char *get_modinfo(struct elf_info *info, const char *tag) 695 696 { 697 return get_next_modinfo(info, tag, NULL); 698 } 699 700 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 701 { 702 return sym ? elf->strtab + sym->st_name : ""; 703 } 704 705 /* 706 * Check whether the 'string' argument matches one of the 'patterns', 707 * an array of shell wildcard patterns (glob). 708 * 709 * Return true is there is a match. 710 */ 711 static bool match(const char *string, const char *const patterns[]) 712 { 713 const char *pattern; 714 715 while ((pattern = *patterns++)) { 716 if (!fnmatch(pattern, string, 0)) 717 return true; 718 } 719 720 return false; 721 } 722 723 /* useful to pass patterns to match() directly */ 724 #define PATTERNS(...) \ 725 ({ \ 726 static const char *const patterns[] = {__VA_ARGS__, NULL}; \ 727 patterns; \ 728 }) 729 730 /* sections that we do not want to do full section mismatch check on */ 731 static const char *const section_white_list[] = 732 { 733 ".comment*", 734 ".debug*", 735 ".zdebug*", /* Compressed debug sections. */ 736 ".GCC.command.line", /* record-gcc-switches */ 737 ".mdebug*", /* alpha, score, mips etc. */ 738 ".pdr", /* alpha, score, mips etc. */ 739 ".stab*", 740 ".note*", 741 ".got*", 742 ".toc*", 743 ".xt.prop", /* xtensa */ 744 ".xt.lit", /* xtensa */ 745 ".arcextmap*", /* arc */ 746 ".gnu.linkonce.arcext*", /* arc : modules */ 747 ".cmem*", /* EZchip */ 748 ".fmt_slot*", /* EZchip */ 749 ".gnu.lto*", 750 ".discard.*", 751 ".llvm.call-graph-profile", /* call graph */ 752 NULL 753 }; 754 755 /* 756 * This is used to find sections missing the SHF_ALLOC flag. 757 * The cause of this is often a section specified in assembler 758 * without "ax" / "aw". 759 */ 760 static void check_section(const char *modname, struct elf_info *elf, 761 Elf_Shdr *sechdr) 762 { 763 const char *sec = sech_name(elf, sechdr); 764 765 if (sechdr->sh_type == SHT_PROGBITS && 766 !(sechdr->sh_flags & SHF_ALLOC) && 767 !match(sec, section_white_list)) { 768 warn("%s (%s): unexpected non-allocatable section.\n" 769 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 770 "Note that for example <linux/init.h> contains\n" 771 "section definitions for use in .S files.\n\n", 772 modname, sec); 773 } 774 } 775 776 777 778 #define ALL_INIT_DATA_SECTIONS \ 779 ".init.setup", ".init.rodata", ".init.data" 780 781 #define ALL_PCI_INIT_SECTIONS \ 782 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 783 ".pci_fixup_enable", ".pci_fixup_resume", \ 784 ".pci_fixup_resume_early", ".pci_fixup_suspend" 785 786 #define ALL_INIT_SECTIONS ".init.*" 787 #define ALL_EXIT_SECTIONS ".exit.*" 788 789 #define DATA_SECTIONS ".data", ".data.rel" 790 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ 791 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \ 792 ".ltext", ".ltext.*" 793 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ 794 ".fixup", ".entry.text", ".exception.text", \ 795 ".coldtext", ".softirqentry.text", ".irqentry.text" 796 797 #define ALL_TEXT_SECTIONS ".init.text", ".exit.text", \ 798 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 799 800 enum mismatch { 801 TEXTDATA_TO_ANY_INIT_EXIT, 802 XXXINIT_TO_SOME_INIT, 803 ANY_INIT_TO_ANY_EXIT, 804 ANY_EXIT_TO_ANY_INIT, 805 EXTABLE_TO_NON_TEXT, 806 }; 807 808 /** 809 * Describe how to match sections on different criteria: 810 * 811 * @fromsec: Array of sections to be matched. 812 * 813 * @bad_tosec: Relocations applied to a section in @fromsec to a section in 814 * this array is forbidden (black-list). Can be empty. 815 * 816 * @good_tosec: Relocations applied to a section in @fromsec must be 817 * targeting sections in this array (white-list). Can be empty. 818 * 819 * @mismatch: Type of mismatch. 820 */ 821 struct sectioncheck { 822 const char *fromsec[20]; 823 const char *bad_tosec[20]; 824 const char *good_tosec[20]; 825 enum mismatch mismatch; 826 }; 827 828 static const struct sectioncheck sectioncheck[] = { 829 /* Do not reference init/exit code/data from 830 * normal code and data 831 */ 832 { 833 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 834 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }, 835 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT, 836 }, 837 /* Do not use exit code/data from init code */ 838 { 839 .fromsec = { ALL_INIT_SECTIONS, NULL }, 840 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 841 .mismatch = ANY_INIT_TO_ANY_EXIT, 842 }, 843 /* Do not use init code/data from exit code */ 844 { 845 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 846 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 847 .mismatch = ANY_EXIT_TO_ANY_INIT, 848 }, 849 { 850 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 851 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 852 .mismatch = ANY_INIT_TO_ANY_EXIT, 853 }, 854 { 855 .fromsec = { "__ex_table", NULL }, 856 /* If you're adding any new black-listed sections in here, consider 857 * adding a special 'printer' for them in scripts/check_extable. 858 */ 859 .bad_tosec = { ".altinstr_replacement", NULL }, 860 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 861 .mismatch = EXTABLE_TO_NON_TEXT, 862 } 863 }; 864 865 static const struct sectioncheck *section_mismatch( 866 const char *fromsec, const char *tosec) 867 { 868 int i; 869 870 /* 871 * The target section could be the SHT_NUL section when we're 872 * handling relocations to un-resolved symbols, trying to match it 873 * doesn't make much sense and causes build failures on parisc 874 * architectures. 875 */ 876 if (*tosec == '\0') 877 return NULL; 878 879 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 880 const struct sectioncheck *check = §ioncheck[i]; 881 882 if (match(fromsec, check->fromsec)) { 883 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 884 return check; 885 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 886 return check; 887 } 888 } 889 return NULL; 890 } 891 892 /** 893 * Whitelist to allow certain references to pass with no warning. 894 * 895 * Pattern 1: 896 * If a module parameter is declared __initdata and permissions=0 897 * then this is legal despite the warning generated. 898 * We cannot see value of permissions here, so just ignore 899 * this pattern. 900 * The pattern is identified by: 901 * tosec = .init.data 902 * fromsec = .data* 903 * atsym =__param* 904 * 905 * Pattern 1a: 906 * module_param_call() ops can refer to __init set function if permissions=0 907 * The pattern is identified by: 908 * tosec = .init.text 909 * fromsec = .data* 910 * atsym = __param_ops_* 911 * 912 * Pattern 3: 913 * Whitelist all references from .head.text to any init section 914 * 915 * Pattern 4: 916 * Some symbols belong to init section but still it is ok to reference 917 * these from non-init sections as these symbols don't have any memory 918 * allocated for them and symbol address and value are same. So even 919 * if init section is freed, its ok to reference those symbols. 920 * For ex. symbols marking the init section boundaries. 921 * This pattern is identified by 922 * refsymname = __init_begin, _sinittext, _einittext 923 * 924 * Pattern 5: 925 * GCC may optimize static inlines when fed constant arg(s) resulting 926 * in functions like cpumask_empty() -- generating an associated symbol 927 * cpumask_empty.constprop.3 that appears in the audit. If the const that 928 * is passed in comes from __init, like say nmi_ipi_mask, we get a 929 * meaningless section warning. May need to add isra symbols too... 930 * This pattern is identified by 931 * tosec = init section 932 * fromsec = text section 933 * refsymname = *.constprop.* 934 * 935 **/ 936 static int secref_whitelist(const char *fromsec, const char *fromsym, 937 const char *tosec, const char *tosym) 938 { 939 /* Check for pattern 1 */ 940 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 941 match(fromsec, PATTERNS(DATA_SECTIONS)) && 942 strstarts(fromsym, "__param")) 943 return 0; 944 945 /* Check for pattern 1a */ 946 if (strcmp(tosec, ".init.text") == 0 && 947 match(fromsec, PATTERNS(DATA_SECTIONS)) && 948 strstarts(fromsym, "__param_ops_")) 949 return 0; 950 951 /* symbols in data sections that may refer to any init/exit sections */ 952 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 953 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 954 match(fromsym, PATTERNS("*_ops", "*_probe", "*_console"))) 955 return 0; 956 957 /* Check for pattern 3 */ 958 if (strstarts(fromsec, ".head.text") && 959 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 960 return 0; 961 962 /* Check for pattern 4 */ 963 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 964 return 0; 965 966 /* Check for pattern 5 */ 967 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 968 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 969 match(fromsym, PATTERNS("*.constprop.*"))) 970 return 0; 971 972 return 1; 973 } 974 975 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 976 unsigned int secndx) 977 { 978 return symsearch_find_nearest(elf, addr, secndx, false, ~0); 979 } 980 981 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 982 { 983 Elf_Sym *new_sym; 984 985 /* If the supplied symbol has a valid name, return it */ 986 if (is_valid_name(elf, sym)) 987 return sym; 988 989 /* 990 * Strive to find a better symbol name, but the resulting name may not 991 * match the symbol referenced in the original code. 992 */ 993 new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym), 994 true, 20); 995 return new_sym ? new_sym : sym; 996 } 997 998 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 999 { 1000 if (secndx >= elf->num_sections) 1001 return false; 1002 1003 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1004 } 1005 1006 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1007 const struct sectioncheck* const mismatch, 1008 Elf_Sym *tsym, 1009 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1010 const char *tosec, Elf_Addr taddr) 1011 { 1012 Elf_Sym *from; 1013 const char *tosym; 1014 const char *fromsym; 1015 char taddr_str[16]; 1016 1017 from = find_fromsym(elf, faddr, fsecndx); 1018 fromsym = sym_name(elf, from); 1019 1020 tsym = find_tosym(elf, taddr, tsym); 1021 tosym = sym_name(elf, tsym); 1022 1023 /* check whitelist - we may ignore it */ 1024 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1025 return; 1026 1027 sec_mismatch_count++; 1028 1029 if (!tosym[0]) 1030 snprintf(taddr_str, sizeof(taddr_str), "0x%x", (unsigned int)taddr); 1031 1032 /* 1033 * The format for the reference source: <symbol_name>+<offset> or <address> 1034 * The format for the reference destination: <symbol_name> or <address> 1035 */ 1036 warn("%s: section mismatch in reference: %s%s0x%x (section: %s) -> %s (section: %s)\n", 1037 modname, fromsym, fromsym[0] ? "+" : "", 1038 (unsigned int)(faddr - (fromsym[0] ? from->st_value : 0)), 1039 fromsec, tosym[0] ? tosym : taddr_str, tosec); 1040 1041 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1042 if (match(tosec, mismatch->bad_tosec)) 1043 fatal("The relocation at %s+0x%lx references\n" 1044 "section \"%s\" which is black-listed.\n" 1045 "Something is seriously wrong and should be fixed.\n" 1046 "You might get more information about where this is\n" 1047 "coming from by using scripts/check_extable.sh %s\n", 1048 fromsec, (long)faddr, tosec, modname); 1049 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1050 warn("The relocation at %s+0x%lx references\n" 1051 "section \"%s\" which is not in the list of\n" 1052 "authorized sections. If you're adding a new section\n" 1053 "and/or if this reference is valid, add \"%s\" to the\n" 1054 "list of authorized sections to jump to on fault.\n" 1055 "This can be achieved by adding \"%s\" to\n" 1056 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1057 fromsec, (long)faddr, tosec, tosec, tosec); 1058 else 1059 error("%s+0x%lx references non-executable section '%s'\n", 1060 fromsec, (long)faddr, tosec); 1061 } 1062 } 1063 1064 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1065 Elf_Addr faddr, const char *secname, 1066 Elf_Sym *sym) 1067 { 1068 static const char *prefix = "__export_symbol_"; 1069 const char *label_name, *name, *data; 1070 Elf_Sym *label; 1071 struct symbol *s; 1072 bool is_gpl; 1073 1074 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1075 label_name = sym_name(elf, label); 1076 1077 if (!strstarts(label_name, prefix)) { 1078 error("%s: .export_symbol section contains strange symbol '%s'\n", 1079 mod->name, label_name); 1080 return; 1081 } 1082 1083 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1084 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1085 error("%s: local symbol '%s' was exported\n", mod->name, 1086 label_name + strlen(prefix)); 1087 return; 1088 } 1089 1090 name = sym_name(elf, sym); 1091 if (strcmp(label_name + strlen(prefix), name)) { 1092 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1093 mod->name, name); 1094 return; 1095 } 1096 1097 data = sym_get_data(elf, label); /* license */ 1098 if (!strcmp(data, "GPL")) { 1099 is_gpl = true; 1100 } else if (!strcmp(data, "")) { 1101 is_gpl = false; 1102 } else { 1103 error("%s: unknown license '%s' was specified for '%s'\n", 1104 mod->name, data, name); 1105 return; 1106 } 1107 1108 data += strlen(data) + 1; /* namespace */ 1109 s = sym_add_exported(name, mod, is_gpl, data); 1110 1111 /* 1112 * We need to be aware whether we are exporting a function or 1113 * a data on some architectures. 1114 */ 1115 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1116 1117 /* 1118 * For parisc64, symbols prefixed $$ from the library have the symbol type 1119 * STT_LOPROC. They should be handled as functions too. 1120 */ 1121 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1122 elf->hdr->e_machine == EM_PARISC && 1123 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1124 s->is_func = true; 1125 1126 if (match(secname, PATTERNS(ALL_INIT_SECTIONS))) 1127 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1128 mod->name, name); 1129 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS))) 1130 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1131 mod->name, name); 1132 } 1133 1134 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1135 Elf_Sym *sym, 1136 unsigned int fsecndx, const char *fromsec, 1137 Elf_Addr faddr, Elf_Addr taddr) 1138 { 1139 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1140 const struct sectioncheck *mismatch; 1141 1142 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1143 check_export_symbol(mod, elf, faddr, tosec, sym); 1144 return; 1145 } 1146 1147 mismatch = section_mismatch(fromsec, tosec); 1148 if (!mismatch) 1149 return; 1150 1151 default_mismatch_handler(mod->name, elf, mismatch, sym, 1152 fsecndx, fromsec, faddr, 1153 tosec, taddr); 1154 } 1155 1156 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1157 { 1158 switch (r_type) { 1159 case R_386_32: 1160 return get_unaligned_native(location); 1161 case R_386_PC32: 1162 return get_unaligned_native(location) + 4; 1163 } 1164 1165 return (Elf_Addr)(-1); 1166 } 1167 1168 static int32_t sign_extend32(int32_t value, int index) 1169 { 1170 uint8_t shift = 31 - index; 1171 1172 return (int32_t)(value << shift) >> shift; 1173 } 1174 1175 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1176 { 1177 uint32_t inst, upper, lower, sign, j1, j2; 1178 int32_t offset; 1179 1180 switch (r_type) { 1181 case R_ARM_ABS32: 1182 case R_ARM_REL32: 1183 inst = get_unaligned_native((uint32_t *)loc); 1184 return inst + sym->st_value; 1185 case R_ARM_MOVW_ABS_NC: 1186 case R_ARM_MOVT_ABS: 1187 inst = get_unaligned_native((uint32_t *)loc); 1188 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1189 15); 1190 return offset + sym->st_value; 1191 case R_ARM_PC24: 1192 case R_ARM_CALL: 1193 case R_ARM_JUMP24: 1194 inst = get_unaligned_native((uint32_t *)loc); 1195 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1196 return offset + sym->st_value + 8; 1197 case R_ARM_THM_MOVW_ABS_NC: 1198 case R_ARM_THM_MOVT_ABS: 1199 upper = get_unaligned_native((uint16_t *)loc); 1200 lower = get_unaligned_native((uint16_t *)loc + 1); 1201 offset = sign_extend32(((upper & 0x000f) << 12) | 1202 ((upper & 0x0400) << 1) | 1203 ((lower & 0x7000) >> 4) | 1204 (lower & 0x00ff), 1205 15); 1206 return offset + sym->st_value; 1207 case R_ARM_THM_JUMP19: 1208 /* 1209 * Encoding T3: 1210 * S = upper[10] 1211 * imm6 = upper[5:0] 1212 * J1 = lower[13] 1213 * J2 = lower[11] 1214 * imm11 = lower[10:0] 1215 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1216 */ 1217 upper = get_unaligned_native((uint16_t *)loc); 1218 lower = get_unaligned_native((uint16_t *)loc + 1); 1219 1220 sign = (upper >> 10) & 1; 1221 j1 = (lower >> 13) & 1; 1222 j2 = (lower >> 11) & 1; 1223 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1224 ((upper & 0x03f) << 12) | 1225 ((lower & 0x07ff) << 1), 1226 20); 1227 return offset + sym->st_value + 4; 1228 case R_ARM_THM_PC22: 1229 case R_ARM_THM_JUMP24: 1230 /* 1231 * Encoding T4: 1232 * S = upper[10] 1233 * imm10 = upper[9:0] 1234 * J1 = lower[13] 1235 * J2 = lower[11] 1236 * imm11 = lower[10:0] 1237 * I1 = NOT(J1 XOR S) 1238 * I2 = NOT(J2 XOR S) 1239 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1240 */ 1241 upper = get_unaligned_native((uint16_t *)loc); 1242 lower = get_unaligned_native((uint16_t *)loc + 1); 1243 1244 sign = (upper >> 10) & 1; 1245 j1 = (lower >> 13) & 1; 1246 j2 = (lower >> 11) & 1; 1247 offset = sign_extend32((sign << 24) | 1248 ((~(j1 ^ sign) & 1) << 23) | 1249 ((~(j2 ^ sign) & 1) << 22) | 1250 ((upper & 0x03ff) << 12) | 1251 ((lower & 0x07ff) << 1), 1252 24); 1253 return offset + sym->st_value + 4; 1254 } 1255 1256 return (Elf_Addr)(-1); 1257 } 1258 1259 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1260 { 1261 uint32_t inst; 1262 1263 inst = get_unaligned_native(location); 1264 switch (r_type) { 1265 case R_MIPS_LO16: 1266 return inst & 0xffff; 1267 case R_MIPS_26: 1268 return (inst & 0x03ffffff) << 2; 1269 case R_MIPS_32: 1270 return inst; 1271 } 1272 return (Elf_Addr)(-1); 1273 } 1274 1275 #ifndef EM_RISCV 1276 #define EM_RISCV 243 1277 #endif 1278 1279 #ifndef R_RISCV_SUB32 1280 #define R_RISCV_SUB32 39 1281 #endif 1282 1283 #ifndef EM_LOONGARCH 1284 #define EM_LOONGARCH 258 1285 #endif 1286 1287 #ifndef R_LARCH_SUB32 1288 #define R_LARCH_SUB32 55 1289 #endif 1290 1291 #ifndef R_LARCH_RELAX 1292 #define R_LARCH_RELAX 100 1293 #endif 1294 1295 #ifndef R_LARCH_ALIGN 1296 #define R_LARCH_ALIGN 102 1297 #endif 1298 1299 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1300 unsigned int *r_type, unsigned int *r_sym) 1301 { 1302 typedef struct { 1303 Elf64_Word r_sym; /* Symbol index */ 1304 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1305 unsigned char r_type3; /* 3rd relocation type */ 1306 unsigned char r_type2; /* 2nd relocation type */ 1307 unsigned char r_type; /* 1st relocation type */ 1308 } Elf64_Mips_R_Info; 1309 1310 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1311 1312 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1313 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1314 1315 *r_type = mips64_r_info->r_type; 1316 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1317 return; 1318 } 1319 1320 if (is_64bit) 1321 r_info = TO_NATIVE((Elf64_Xword)r_info); 1322 else 1323 r_info = TO_NATIVE((Elf32_Word)r_info); 1324 1325 *r_type = ELF_R_TYPE(r_info); 1326 *r_sym = ELF_R_SYM(r_info); 1327 } 1328 1329 static void section_rela(struct module *mod, struct elf_info *elf, 1330 unsigned int fsecndx, const char *fromsec, 1331 const Elf_Rela *start, const Elf_Rela *stop) 1332 { 1333 const Elf_Rela *rela; 1334 1335 for (rela = start; rela < stop; rela++) { 1336 Elf_Sym *tsym; 1337 Elf_Addr taddr, r_offset; 1338 unsigned int r_type, r_sym; 1339 1340 r_offset = TO_NATIVE(rela->r_offset); 1341 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1342 1343 tsym = elf->symtab_start + r_sym; 1344 taddr = tsym->st_value + TO_NATIVE(rela->r_addend); 1345 1346 switch (elf->hdr->e_machine) { 1347 case EM_RISCV: 1348 if (!strcmp("__ex_table", fromsec) && 1349 r_type == R_RISCV_SUB32) 1350 continue; 1351 break; 1352 case EM_LOONGARCH: 1353 switch (r_type) { 1354 case R_LARCH_SUB32: 1355 if (!strcmp("__ex_table", fromsec)) 1356 continue; 1357 break; 1358 case R_LARCH_RELAX: 1359 case R_LARCH_ALIGN: 1360 /* These relocs do not refer to symbols */ 1361 continue; 1362 } 1363 break; 1364 } 1365 1366 check_section_mismatch(mod, elf, tsym, 1367 fsecndx, fromsec, r_offset, taddr); 1368 } 1369 } 1370 1371 static void section_rel(struct module *mod, struct elf_info *elf, 1372 unsigned int fsecndx, const char *fromsec, 1373 const Elf_Rel *start, const Elf_Rel *stop) 1374 { 1375 const Elf_Rel *rel; 1376 1377 for (rel = start; rel < stop; rel++) { 1378 Elf_Sym *tsym; 1379 Elf_Addr taddr, r_offset; 1380 unsigned int r_type, r_sym; 1381 void *loc; 1382 1383 r_offset = TO_NATIVE(rel->r_offset); 1384 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1385 1386 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1387 tsym = elf->symtab_start + r_sym; 1388 1389 switch (elf->hdr->e_machine) { 1390 case EM_386: 1391 taddr = addend_386_rel(loc, r_type); 1392 break; 1393 case EM_ARM: 1394 taddr = addend_arm_rel(loc, tsym, r_type); 1395 break; 1396 case EM_MIPS: 1397 taddr = addend_mips_rel(loc, r_type); 1398 break; 1399 default: 1400 fatal("Please add code to calculate addend for this architecture\n"); 1401 } 1402 1403 check_section_mismatch(mod, elf, tsym, 1404 fsecndx, fromsec, r_offset, taddr); 1405 } 1406 } 1407 1408 /** 1409 * A module includes a number of sections that are discarded 1410 * either when loaded or when used as built-in. 1411 * For loaded modules all functions marked __init and all data 1412 * marked __initdata will be discarded when the module has been initialized. 1413 * Likewise for modules used built-in the sections marked __exit 1414 * are discarded because __exit marked function are supposed to be called 1415 * only when a module is unloaded which never happens for built-in modules. 1416 * The check_sec_ref() function traverses all relocation records 1417 * to find all references to a section that reference a section that will 1418 * be discarded and warns about it. 1419 **/ 1420 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1421 { 1422 int i; 1423 1424 /* Walk through all sections */ 1425 for (i = 0; i < elf->num_sections; i++) { 1426 Elf_Shdr *sechdr = &elf->sechdrs[i]; 1427 1428 check_section(mod->name, elf, sechdr); 1429 /* We want to process only relocation sections and not .init */ 1430 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) { 1431 /* section to which the relocation applies */ 1432 unsigned int secndx = sechdr->sh_info; 1433 const char *secname = sec_name(elf, secndx); 1434 const void *start, *stop; 1435 1436 /* If the section is known good, skip it */ 1437 if (match(secname, section_white_list)) 1438 continue; 1439 1440 start = sym_get_data_by_offset(elf, i, 0); 1441 stop = start + sechdr->sh_size; 1442 1443 if (sechdr->sh_type == SHT_RELA) 1444 section_rela(mod, elf, secndx, secname, 1445 start, stop); 1446 else 1447 section_rel(mod, elf, secndx, secname, 1448 start, stop); 1449 } 1450 } 1451 } 1452 1453 static char *remove_dot(char *s) 1454 { 1455 size_t n = strcspn(s, "."); 1456 1457 if (n && s[n]) { 1458 size_t m = strspn(s + n + 1, "0123456789"); 1459 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1460 s[n] = 0; 1461 } 1462 return s; 1463 } 1464 1465 /* 1466 * The CRCs are recorded in .*.cmd files in the form of: 1467 * #SYMVER <name> <crc> 1468 */ 1469 static void extract_crcs_for_object(const char *object, struct module *mod) 1470 { 1471 char cmd_file[PATH_MAX]; 1472 char *buf, *p; 1473 const char *base; 1474 int dirlen, ret; 1475 1476 base = get_basename(object); 1477 dirlen = base - object; 1478 1479 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1480 dirlen, object, base); 1481 if (ret >= sizeof(cmd_file)) { 1482 error("%s: too long path was truncated\n", cmd_file); 1483 return; 1484 } 1485 1486 buf = read_text_file(cmd_file); 1487 p = buf; 1488 1489 while ((p = strstr(p, "\n#SYMVER "))) { 1490 char *name; 1491 size_t namelen; 1492 unsigned int crc; 1493 struct symbol *sym; 1494 1495 name = p + strlen("\n#SYMVER "); 1496 1497 p = strchr(name, ' '); 1498 if (!p) 1499 break; 1500 1501 namelen = p - name; 1502 p++; 1503 1504 if (!isdigit(*p)) 1505 continue; /* skip this line */ 1506 1507 crc = strtoul(p, &p, 0); 1508 if (*p != '\n') 1509 continue; /* skip this line */ 1510 1511 name[namelen] = '\0'; 1512 1513 /* 1514 * sym_find_with_module() may return NULL here. 1515 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1516 * Since commit e1327a127703, genksyms calculates CRCs of all 1517 * symbols, including trimmed ones. Ignore orphan CRCs. 1518 */ 1519 sym = sym_find_with_module(name, mod); 1520 if (sym) 1521 sym_set_crc(sym, crc); 1522 } 1523 1524 free(buf); 1525 } 1526 1527 /* 1528 * The symbol versions (CRC) are recorded in the .*.cmd files. 1529 * Parse them to retrieve CRCs for the current module. 1530 */ 1531 static void mod_set_crcs(struct module *mod) 1532 { 1533 char objlist[PATH_MAX]; 1534 char *buf, *p, *obj; 1535 int ret; 1536 1537 if (mod->is_vmlinux) { 1538 strcpy(objlist, ".vmlinux.objs"); 1539 } else { 1540 /* objects for a module are listed in the *.mod file. */ 1541 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1542 if (ret >= sizeof(objlist)) { 1543 error("%s: too long path was truncated\n", objlist); 1544 return; 1545 } 1546 } 1547 1548 buf = read_text_file(objlist); 1549 p = buf; 1550 1551 while ((obj = strsep(&p, "\n")) && obj[0]) 1552 extract_crcs_for_object(obj, mod); 1553 1554 free(buf); 1555 } 1556 1557 static void read_symbols(const char *modname) 1558 { 1559 const char *symname; 1560 char *version; 1561 char *license; 1562 char *namespace; 1563 struct module *mod; 1564 struct elf_info info = { }; 1565 Elf_Sym *sym; 1566 1567 if (!parse_elf(&info, modname)) 1568 return; 1569 1570 if (!strends(modname, ".o")) { 1571 error("%s: filename must be suffixed with .o\n", modname); 1572 return; 1573 } 1574 1575 /* strip trailing .o */ 1576 mod = new_module(modname, strlen(modname) - strlen(".o")); 1577 1578 /* save .no_trim_symbol section for later use */ 1579 if (info.no_trim_symbol_len) { 1580 mod->no_trim_symbol = xmalloc(info.no_trim_symbol_len); 1581 memcpy(mod->no_trim_symbol, info.no_trim_symbol, 1582 info.no_trim_symbol_len); 1583 mod->no_trim_symbol_len = info.no_trim_symbol_len; 1584 } 1585 1586 if (!mod->is_vmlinux) { 1587 license = get_modinfo(&info, "license"); 1588 if (!license) 1589 error("missing MODULE_LICENSE() in %s\n", modname); 1590 while (license) { 1591 if (!license_is_gpl_compatible(license)) { 1592 mod->is_gpl_compatible = false; 1593 break; 1594 } 1595 license = get_next_modinfo(&info, "license", license); 1596 } 1597 1598 namespace = get_modinfo(&info, "import_ns"); 1599 while (namespace) { 1600 add_namespace(&mod->imported_namespaces, namespace); 1601 namespace = get_next_modinfo(&info, "import_ns", 1602 namespace); 1603 } 1604 1605 if (!get_modinfo(&info, "description")) 1606 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1607 } 1608 1609 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1610 symname = remove_dot(info.strtab + sym->st_name); 1611 1612 handle_symbol(mod, &info, sym, symname); 1613 handle_moddevtable(mod, &info, sym, symname); 1614 } 1615 1616 check_sec_ref(mod, &info); 1617 1618 if (!mod->is_vmlinux) { 1619 version = get_modinfo(&info, "version"); 1620 if (version || all_versions) 1621 get_src_version(mod->name, mod->srcversion, 1622 sizeof(mod->srcversion) - 1); 1623 } 1624 1625 parse_elf_finish(&info); 1626 1627 if (modversions) { 1628 /* 1629 * Our trick to get versioning for module struct etc. - it's 1630 * never passed as an argument to an exported function, so 1631 * the automatic versioning doesn't pick it up, but it's really 1632 * important anyhow. 1633 */ 1634 sym_add_unresolved("module_layout", mod, false); 1635 1636 mod_set_crcs(mod); 1637 } 1638 } 1639 1640 static void read_symbols_from_files(const char *filename) 1641 { 1642 FILE *in = stdin; 1643 char fname[PATH_MAX]; 1644 1645 in = fopen(filename, "r"); 1646 if (!in) 1647 fatal("Can't open filenames file %s: %m", filename); 1648 1649 while (fgets(fname, PATH_MAX, in) != NULL) { 1650 if (strends(fname, "\n")) 1651 fname[strlen(fname)-1] = '\0'; 1652 read_symbols(fname); 1653 } 1654 1655 fclose(in); 1656 } 1657 1658 #define SZ 500 1659 1660 /* We first write the generated file into memory using the 1661 * following helper, then compare to the file on disk and 1662 * only update the later if anything changed */ 1663 1664 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1665 const char *fmt, ...) 1666 { 1667 char tmp[SZ]; 1668 int len; 1669 va_list ap; 1670 1671 va_start(ap, fmt); 1672 len = vsnprintf(tmp, SZ, fmt, ap); 1673 buf_write(buf, tmp, len); 1674 va_end(ap); 1675 } 1676 1677 void buf_write(struct buffer *buf, const char *s, int len) 1678 { 1679 if (buf->size - buf->pos < len) { 1680 buf->size += len + SZ; 1681 buf->p = xrealloc(buf->p, buf->size); 1682 } 1683 strncpy(buf->p + buf->pos, s, len); 1684 buf->pos += len; 1685 } 1686 1687 static void check_exports(struct module *mod) 1688 { 1689 struct symbol *s, *exp; 1690 1691 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1692 const char *basename; 1693 exp = find_symbol(s->name); 1694 if (!exp) { 1695 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1696 modpost_log(!warn_unresolved, 1697 "\"%s\" [%s.ko] undefined!\n", 1698 s->name, mod->name); 1699 continue; 1700 } 1701 if (exp->module == mod) { 1702 error("\"%s\" [%s.ko] was exported without definition\n", 1703 s->name, mod->name); 1704 continue; 1705 } 1706 1707 exp->used = true; 1708 s->module = exp->module; 1709 s->crc_valid = exp->crc_valid; 1710 s->crc = exp->crc; 1711 1712 basename = get_basename(mod->name); 1713 1714 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1715 modpost_log(!allow_missing_ns_imports, 1716 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1717 basename, exp->name, exp->namespace); 1718 add_namespace(&mod->missing_namespaces, exp->namespace); 1719 } 1720 1721 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1722 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1723 basename, exp->name); 1724 } 1725 } 1726 1727 static void handle_white_list_exports(const char *white_list) 1728 { 1729 char *buf, *p, *name; 1730 1731 buf = read_text_file(white_list); 1732 p = buf; 1733 1734 while ((name = strsep(&p, "\n"))) { 1735 struct symbol *sym = find_symbol(name); 1736 1737 if (sym) 1738 sym->used = true; 1739 } 1740 1741 free(buf); 1742 } 1743 1744 /* 1745 * Keep symbols recorded in the .no_trim_symbol section. This is necessary to 1746 * prevent CONFIG_TRIM_UNUSED_KSYMS from dropping EXPORT_SYMBOL because 1747 * symbol_get() relies on the symbol being present in the ksymtab for lookups. 1748 */ 1749 static void keep_no_trim_symbols(struct module *mod) 1750 { 1751 unsigned long size = mod->no_trim_symbol_len; 1752 1753 for (char *s = mod->no_trim_symbol; s; s = next_string(s , &size)) { 1754 struct symbol *sym; 1755 1756 /* 1757 * If find_symbol() returns NULL, this symbol is not provided 1758 * by any module, and symbol_get() will fail. 1759 */ 1760 sym = find_symbol(s); 1761 if (sym) 1762 sym->used = true; 1763 } 1764 } 1765 1766 static void check_modname_len(struct module *mod) 1767 { 1768 const char *mod_name; 1769 1770 mod_name = get_basename(mod->name); 1771 1772 if (strlen(mod_name) >= MODULE_NAME_LEN) 1773 error("module name is too long [%s.ko]\n", mod->name); 1774 } 1775 1776 /** 1777 * Header for the generated file 1778 **/ 1779 static void add_header(struct buffer *b, struct module *mod) 1780 { 1781 buf_printf(b, "#include <linux/module.h>\n"); 1782 buf_printf(b, "#include <linux/export-internal.h>\n"); 1783 buf_printf(b, "#include <linux/compiler.h>\n"); 1784 buf_printf(b, "\n"); 1785 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1786 buf_printf(b, "\n"); 1787 buf_printf(b, "__visible struct module __this_module\n"); 1788 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1789 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1790 if (mod->has_init) 1791 buf_printf(b, "\t.init = init_module,\n"); 1792 if (mod->has_cleanup) 1793 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1794 "\t.exit = cleanup_module,\n" 1795 "#endif\n"); 1796 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1797 buf_printf(b, "};\n"); 1798 1799 if (!external_module) 1800 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1801 1802 if (strstarts(mod->name, "drivers/staging")) 1803 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1804 1805 if (strstarts(mod->name, "tools/testing")) 1806 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1807 } 1808 1809 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1810 { 1811 struct symbol *sym; 1812 1813 /* generate struct for exported symbols */ 1814 buf_printf(buf, "\n"); 1815 list_for_each_entry(sym, &mod->exported_symbols, list) { 1816 if (trim_unused_exports && !sym->used) 1817 continue; 1818 1819 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1820 sym->is_func ? "FUNC" : "DATA", sym->name, 1821 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1822 } 1823 1824 if (!modversions) 1825 return; 1826 1827 /* record CRCs for exported symbols */ 1828 buf_printf(buf, "\n"); 1829 list_for_each_entry(sym, &mod->exported_symbols, list) { 1830 if (trim_unused_exports && !sym->used) 1831 continue; 1832 1833 if (!sym->crc_valid) 1834 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1835 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1836 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1837 sym->name); 1838 1839 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1840 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1841 } 1842 } 1843 1844 /** 1845 * Record CRCs for unresolved symbols, supporting long names 1846 */ 1847 static void add_extended_versions(struct buffer *b, struct module *mod) 1848 { 1849 struct symbol *s; 1850 1851 if (!extended_modversions) 1852 return; 1853 1854 buf_printf(b, "\n"); 1855 buf_printf(b, "static const u32 ____version_ext_crcs[]\n"); 1856 buf_printf(b, "__used __section(\"__version_ext_crcs\") = {\n"); 1857 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1858 if (!s->module) 1859 continue; 1860 if (!s->crc_valid) { 1861 warn("\"%s\" [%s.ko] has no CRC!\n", 1862 s->name, mod->name); 1863 continue; 1864 } 1865 buf_printf(b, "\t0x%08x,\n", s->crc); 1866 } 1867 buf_printf(b, "};\n"); 1868 1869 buf_printf(b, "static const char ____version_ext_names[]\n"); 1870 buf_printf(b, "__used __section(\"__version_ext_names\") =\n"); 1871 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1872 if (!s->module) 1873 continue; 1874 if (!s->crc_valid) 1875 /* 1876 * We already warned on this when producing the crc 1877 * table. 1878 * We need to skip its name too, as the indexes in 1879 * both tables need to align. 1880 */ 1881 continue; 1882 buf_printf(b, "\t\"%s\\0\"\n", s->name); 1883 } 1884 buf_printf(b, ";\n"); 1885 } 1886 1887 /** 1888 * Record CRCs for unresolved symbols 1889 **/ 1890 static void add_versions(struct buffer *b, struct module *mod) 1891 { 1892 struct symbol *s; 1893 1894 if (!basic_modversions) 1895 return; 1896 1897 buf_printf(b, "\n"); 1898 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1899 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1900 1901 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1902 if (!s->module) 1903 continue; 1904 if (!s->crc_valid) { 1905 warn("\"%s\" [%s.ko] has no CRC!\n", 1906 s->name, mod->name); 1907 continue; 1908 } 1909 if (strlen(s->name) >= MODULE_NAME_LEN) { 1910 if (extended_modversions) { 1911 /* this symbol will only be in the extended info */ 1912 continue; 1913 } else { 1914 error("too long symbol \"%s\" [%s.ko]\n", 1915 s->name, mod->name); 1916 break; 1917 } 1918 } 1919 buf_printf(b, "\t{ 0x%08x, \"%s\" },\n", 1920 s->crc, s->name); 1921 } 1922 1923 buf_printf(b, "};\n"); 1924 } 1925 1926 static void add_depends(struct buffer *b, struct module *mod) 1927 { 1928 struct symbol *s; 1929 int first = 1; 1930 1931 /* Clear ->seen flag of modules that own symbols needed by this. */ 1932 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1933 if (s->module) 1934 s->module->seen = s->module->is_vmlinux; 1935 } 1936 1937 buf_printf(b, "\n"); 1938 buf_printf(b, "MODULE_INFO(depends, \""); 1939 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1940 const char *p; 1941 if (!s->module) 1942 continue; 1943 1944 if (s->module->seen) 1945 continue; 1946 1947 s->module->seen = true; 1948 p = get_basename(s->module->name); 1949 buf_printf(b, "%s%s", first ? "" : ",", p); 1950 first = 0; 1951 } 1952 buf_printf(b, "\");\n"); 1953 } 1954 1955 static void add_srcversion(struct buffer *b, struct module *mod) 1956 { 1957 if (mod->srcversion[0]) { 1958 buf_printf(b, "\n"); 1959 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1960 mod->srcversion); 1961 } 1962 } 1963 1964 static void write_buf(struct buffer *b, const char *fname) 1965 { 1966 FILE *file; 1967 1968 if (error_occurred) 1969 return; 1970 1971 file = fopen(fname, "w"); 1972 if (!file) { 1973 perror(fname); 1974 exit(1); 1975 } 1976 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1977 perror(fname); 1978 exit(1); 1979 } 1980 if (fclose(file) != 0) { 1981 perror(fname); 1982 exit(1); 1983 } 1984 } 1985 1986 static void write_if_changed(struct buffer *b, const char *fname) 1987 { 1988 char *tmp; 1989 FILE *file; 1990 struct stat st; 1991 1992 file = fopen(fname, "r"); 1993 if (!file) 1994 goto write; 1995 1996 if (fstat(fileno(file), &st) < 0) 1997 goto close_write; 1998 1999 if (st.st_size != b->pos) 2000 goto close_write; 2001 2002 tmp = xmalloc(b->pos); 2003 if (fread(tmp, 1, b->pos, file) != b->pos) 2004 goto free_write; 2005 2006 if (memcmp(tmp, b->p, b->pos) != 0) 2007 goto free_write; 2008 2009 free(tmp); 2010 fclose(file); 2011 return; 2012 2013 free_write: 2014 free(tmp); 2015 close_write: 2016 fclose(file); 2017 write: 2018 write_buf(b, fname); 2019 } 2020 2021 static void write_vmlinux_export_c_file(struct module *mod) 2022 { 2023 struct buffer buf = { }; 2024 2025 buf_printf(&buf, 2026 "#include <linux/export-internal.h>\n"); 2027 2028 add_exported_symbols(&buf, mod); 2029 write_if_changed(&buf, ".vmlinux.export.c"); 2030 free(buf.p); 2031 } 2032 2033 /* do sanity checks, and generate *.mod.c file */ 2034 static void write_mod_c_file(struct module *mod) 2035 { 2036 struct buffer buf = { }; 2037 struct module_alias *alias, *next; 2038 char fname[PATH_MAX]; 2039 int ret; 2040 2041 add_header(&buf, mod); 2042 add_exported_symbols(&buf, mod); 2043 add_versions(&buf, mod); 2044 add_extended_versions(&buf, mod); 2045 add_depends(&buf, mod); 2046 2047 buf_printf(&buf, "\n"); 2048 list_for_each_entry_safe(alias, next, &mod->aliases, node) { 2049 buf_printf(&buf, "MODULE_ALIAS(\"%s\");\n", alias->str); 2050 list_del(&alias->node); 2051 free(alias); 2052 } 2053 2054 add_srcversion(&buf, mod); 2055 2056 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2057 if (ret >= sizeof(fname)) { 2058 error("%s: too long path was truncated\n", fname); 2059 goto free; 2060 } 2061 2062 write_if_changed(&buf, fname); 2063 2064 free: 2065 free(buf.p); 2066 } 2067 2068 /* parse Module.symvers file. line format: 2069 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2070 **/ 2071 static void read_dump(const char *fname) 2072 { 2073 char *buf, *pos, *line; 2074 2075 buf = read_text_file(fname); 2076 if (!buf) 2077 /* No symbol versions, silently ignore */ 2078 return; 2079 2080 pos = buf; 2081 2082 while ((line = get_line(&pos))) { 2083 char *symname, *namespace, *modname, *d, *export; 2084 unsigned int crc; 2085 struct module *mod; 2086 struct symbol *s; 2087 bool gpl_only; 2088 2089 if (!(symname = strchr(line, '\t'))) 2090 goto fail; 2091 *symname++ = '\0'; 2092 if (!(modname = strchr(symname, '\t'))) 2093 goto fail; 2094 *modname++ = '\0'; 2095 if (!(export = strchr(modname, '\t'))) 2096 goto fail; 2097 *export++ = '\0'; 2098 if (!(namespace = strchr(export, '\t'))) 2099 goto fail; 2100 *namespace++ = '\0'; 2101 2102 crc = strtoul(line, &d, 16); 2103 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2104 goto fail; 2105 2106 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2107 gpl_only = true; 2108 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2109 gpl_only = false; 2110 } else { 2111 error("%s: unknown license %s. skip", symname, export); 2112 continue; 2113 } 2114 2115 mod = find_module(fname, modname); 2116 if (!mod) { 2117 mod = new_module(modname, strlen(modname)); 2118 mod->dump_file = fname; 2119 } 2120 s = sym_add_exported(symname, mod, gpl_only, namespace); 2121 sym_set_crc(s, crc); 2122 } 2123 free(buf); 2124 return; 2125 fail: 2126 free(buf); 2127 fatal("parse error in symbol dump file\n"); 2128 } 2129 2130 static void write_dump(const char *fname) 2131 { 2132 struct buffer buf = { }; 2133 struct module *mod; 2134 struct symbol *sym; 2135 2136 list_for_each_entry(mod, &modules, list) { 2137 if (mod->dump_file) 2138 continue; 2139 list_for_each_entry(sym, &mod->exported_symbols, list) { 2140 if (trim_unused_exports && !sym->used) 2141 continue; 2142 2143 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2144 sym->crc, sym->name, mod->name, 2145 sym->is_gpl_only ? "_GPL" : "", 2146 sym->namespace); 2147 } 2148 } 2149 write_buf(&buf, fname); 2150 free(buf.p); 2151 } 2152 2153 static void write_namespace_deps_files(const char *fname) 2154 { 2155 struct module *mod; 2156 struct namespace_list *ns; 2157 struct buffer ns_deps_buf = {}; 2158 2159 list_for_each_entry(mod, &modules, list) { 2160 2161 if (mod->dump_file || list_empty(&mod->missing_namespaces)) 2162 continue; 2163 2164 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2165 2166 list_for_each_entry(ns, &mod->missing_namespaces, list) 2167 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2168 2169 buf_printf(&ns_deps_buf, "\n"); 2170 } 2171 2172 write_if_changed(&ns_deps_buf, fname); 2173 free(ns_deps_buf.p); 2174 } 2175 2176 struct dump_list { 2177 struct list_head list; 2178 const char *file; 2179 }; 2180 2181 static void check_host_endian(void) 2182 { 2183 static const union { 2184 short s; 2185 char c[2]; 2186 } endian_test = { .c = {0x01, 0x02} }; 2187 2188 switch (endian_test.s) { 2189 case 0x0102: 2190 host_is_big_endian = true; 2191 break; 2192 case 0x0201: 2193 host_is_big_endian = false; 2194 break; 2195 default: 2196 fatal("Unknown host endian\n"); 2197 } 2198 } 2199 2200 int main(int argc, char **argv) 2201 { 2202 struct module *mod; 2203 char *missing_namespace_deps = NULL; 2204 char *unused_exports_white_list = NULL; 2205 char *dump_write = NULL, *files_source = NULL; 2206 int opt; 2207 LIST_HEAD(dump_lists); 2208 struct dump_list *dl, *dl2; 2209 2210 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:xb")) != -1) { 2211 switch (opt) { 2212 case 'e': 2213 external_module = true; 2214 break; 2215 case 'i': 2216 dl = xmalloc(sizeof(*dl)); 2217 dl->file = optarg; 2218 list_add_tail(&dl->list, &dump_lists); 2219 break; 2220 case 'M': 2221 module_enabled = true; 2222 break; 2223 case 'm': 2224 modversions = true; 2225 break; 2226 case 'n': 2227 ignore_missing_files = true; 2228 break; 2229 case 'o': 2230 dump_write = optarg; 2231 break; 2232 case 'a': 2233 all_versions = true; 2234 break; 2235 case 'T': 2236 files_source = optarg; 2237 break; 2238 case 't': 2239 trim_unused_exports = true; 2240 break; 2241 case 'u': 2242 unused_exports_white_list = optarg; 2243 break; 2244 case 'W': 2245 extra_warn = true; 2246 break; 2247 case 'w': 2248 warn_unresolved = true; 2249 break; 2250 case 'E': 2251 sec_mismatch_warn_only = false; 2252 break; 2253 case 'N': 2254 allow_missing_ns_imports = true; 2255 break; 2256 case 'd': 2257 missing_namespace_deps = optarg; 2258 break; 2259 case 'b': 2260 basic_modversions = true; 2261 break; 2262 case 'x': 2263 extended_modversions = true; 2264 break; 2265 default: 2266 exit(1); 2267 } 2268 } 2269 2270 check_host_endian(); 2271 2272 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2273 read_dump(dl->file); 2274 list_del(&dl->list); 2275 free(dl); 2276 } 2277 2278 while (optind < argc) 2279 read_symbols(argv[optind++]); 2280 2281 if (files_source) 2282 read_symbols_from_files(files_source); 2283 2284 list_for_each_entry(mod, &modules, list) { 2285 keep_no_trim_symbols(mod); 2286 2287 if (mod->dump_file || mod->is_vmlinux) 2288 continue; 2289 2290 check_modname_len(mod); 2291 check_exports(mod); 2292 } 2293 2294 if (unused_exports_white_list) 2295 handle_white_list_exports(unused_exports_white_list); 2296 2297 list_for_each_entry(mod, &modules, list) { 2298 if (mod->dump_file) 2299 continue; 2300 2301 if (mod->is_vmlinux) 2302 write_vmlinux_export_c_file(mod); 2303 else 2304 write_mod_c_file(mod); 2305 } 2306 2307 if (missing_namespace_deps) 2308 write_namespace_deps_files(missing_namespace_deps); 2309 2310 if (dump_write) 2311 write_dump(dump_write); 2312 if (sec_mismatch_count && !sec_mismatch_warn_only) 2313 error("Section mismatches detected.\n" 2314 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2315 2316 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2317 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2318 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2319 2320 return error_occurred ? 1 : 0; 2321 } 2322