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 #include "modpost.h" 24 #include "../../include/linux/license.h" 25 26 static bool module_enabled; 27 /* Are we using CONFIG_MODVERSIONS? */ 28 static bool modversions; 29 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 30 static bool all_versions; 31 /* If we are modposting external module set to 1 */ 32 static bool external_module; 33 /* Only warn about unresolved symbols */ 34 static bool warn_unresolved; 35 36 static int sec_mismatch_count; 37 static bool sec_mismatch_warn_only = true; 38 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */ 39 static bool trim_unused_exports; 40 41 /* ignore missing files */ 42 static bool ignore_missing_files; 43 /* If set to 1, only warn (instead of error) about missing ns imports */ 44 static bool allow_missing_ns_imports; 45 46 static bool error_occurred; 47 48 static bool extra_warn; 49 50 /* 51 * Cut off the warnings when there are too many. This typically occurs when 52 * vmlinux is missing. ('make modules' without building vmlinux.) 53 */ 54 #define MAX_UNRESOLVED_REPORTS 10 55 static unsigned int nr_unresolved; 56 57 /* In kernel, this size is defined in linux/module.h; 58 * here we use Elf_Addr instead of long for covering cross-compile 59 */ 60 61 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) 62 63 void modpost_log(enum loglevel loglevel, const char *fmt, ...) 64 { 65 va_list arglist; 66 67 switch (loglevel) { 68 case LOG_WARN: 69 fprintf(stderr, "WARNING: "); 70 break; 71 case LOG_ERROR: 72 fprintf(stderr, "ERROR: "); 73 error_occurred = true; 74 break; 75 default: /* invalid loglevel, ignore */ 76 break; 77 } 78 79 fprintf(stderr, "modpost: "); 80 81 va_start(arglist, fmt); 82 vfprintf(stderr, fmt, arglist); 83 va_end(arglist); 84 } 85 86 static inline bool strends(const char *str, const char *postfix) 87 { 88 if (strlen(str) < strlen(postfix)) 89 return false; 90 91 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; 92 } 93 94 void *do_nofail(void *ptr, const char *expr) 95 { 96 if (!ptr) 97 fatal("Memory allocation failure: %s.\n", expr); 98 99 return ptr; 100 } 101 102 char *read_text_file(const char *filename) 103 { 104 struct stat st; 105 size_t nbytes; 106 int fd; 107 char *buf; 108 109 fd = open(filename, O_RDONLY); 110 if (fd < 0) { 111 perror(filename); 112 exit(1); 113 } 114 115 if (fstat(fd, &st) < 0) { 116 perror(filename); 117 exit(1); 118 } 119 120 buf = NOFAIL(malloc(st.st_size + 1)); 121 122 nbytes = st.st_size; 123 124 while (nbytes) { 125 ssize_t bytes_read; 126 127 bytes_read = read(fd, buf, nbytes); 128 if (bytes_read < 0) { 129 perror(filename); 130 exit(1); 131 } 132 133 nbytes -= bytes_read; 134 } 135 buf[st.st_size] = '\0'; 136 137 close(fd); 138 139 return buf; 140 } 141 142 char *get_line(char **stringp) 143 { 144 char *orig = *stringp, *next; 145 146 /* do not return the unwanted extra line at EOF */ 147 if (!orig || *orig == '\0') 148 return NULL; 149 150 /* don't use strsep here, it is not available everywhere */ 151 next = strchr(orig, '\n'); 152 if (next) 153 *next++ = '\0'; 154 155 *stringp = next; 156 157 return orig; 158 } 159 160 /* A list of all modules we processed */ 161 LIST_HEAD(modules); 162 163 static struct module *find_module(const char *modname) 164 { 165 struct module *mod; 166 167 list_for_each_entry(mod, &modules, list) { 168 if (strcmp(mod->name, modname) == 0) 169 return mod; 170 } 171 return NULL; 172 } 173 174 static struct module *new_module(const char *name, size_t namelen) 175 { 176 struct module *mod; 177 178 mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1)); 179 memset(mod, 0, sizeof(*mod)); 180 181 INIT_LIST_HEAD(&mod->exported_symbols); 182 INIT_LIST_HEAD(&mod->unresolved_symbols); 183 INIT_LIST_HEAD(&mod->missing_namespaces); 184 INIT_LIST_HEAD(&mod->imported_namespaces); 185 186 memcpy(mod->name, name, namelen); 187 mod->name[namelen] = '\0'; 188 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0); 189 190 /* 191 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE() 192 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue 193 * modpost will exit wiht error anyway. 194 */ 195 mod->is_gpl_compatible = true; 196 197 list_add_tail(&mod->list, &modules); 198 199 return mod; 200 } 201 202 /* A hash of all exported symbols, 203 * struct symbol is also used for lists of unresolved symbols */ 204 205 #define SYMBOL_HASH_SIZE 1024 206 207 struct symbol { 208 struct symbol *next; 209 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */ 210 struct module *module; 211 char *namespace; 212 unsigned int crc; 213 bool crc_valid; 214 bool weak; 215 bool is_func; 216 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ 217 bool used; /* there exists a user of this symbol */ 218 char name[]; 219 }; 220 221 static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 222 223 /* This is based on the hash algorithm from gdbm, via tdb */ 224 static inline unsigned int tdb_hash(const char *name) 225 { 226 unsigned value; /* Used to compute the hash value. */ 227 unsigned i; /* Used to cycle through random values. */ 228 229 /* Set the initial value from the key size. */ 230 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++) 231 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 232 233 return (1103515243 * value + 12345); 234 } 235 236 /** 237 * Allocate a new symbols for use in the hash of exported symbols or 238 * the list of unresolved symbols per module 239 **/ 240 static struct symbol *alloc_symbol(const char *name) 241 { 242 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 243 244 memset(s, 0, sizeof(*s)); 245 strcpy(s->name, name); 246 247 return s; 248 } 249 250 /* For the hash of exported symbols */ 251 static void hash_add_symbol(struct symbol *sym) 252 { 253 unsigned int hash; 254 255 hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE; 256 sym->next = symbolhash[hash]; 257 symbolhash[hash] = sym; 258 } 259 260 static void sym_add_unresolved(const char *name, struct module *mod, bool weak) 261 { 262 struct symbol *sym; 263 264 sym = alloc_symbol(name); 265 sym->weak = weak; 266 267 list_add_tail(&sym->list, &mod->unresolved_symbols); 268 } 269 270 static struct symbol *sym_find_with_module(const char *name, struct module *mod) 271 { 272 struct symbol *s; 273 274 /* For our purposes, .foo matches foo. PPC64 needs this. */ 275 if (name[0] == '.') 276 name++; 277 278 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) { 279 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) 280 return s; 281 } 282 return NULL; 283 } 284 285 static struct symbol *find_symbol(const char *name) 286 { 287 return sym_find_with_module(name, NULL); 288 } 289 290 struct namespace_list { 291 struct list_head list; 292 char namespace[]; 293 }; 294 295 static bool contains_namespace(struct list_head *head, const char *namespace) 296 { 297 struct namespace_list *list; 298 299 /* 300 * The default namespace is null string "", which is always implicitly 301 * contained. 302 */ 303 if (!namespace[0]) 304 return true; 305 306 list_for_each_entry(list, head, list) { 307 if (!strcmp(list->namespace, namespace)) 308 return true; 309 } 310 311 return false; 312 } 313 314 static void add_namespace(struct list_head *head, const char *namespace) 315 { 316 struct namespace_list *ns_entry; 317 318 if (!contains_namespace(head, namespace)) { 319 ns_entry = NOFAIL(malloc(sizeof(*ns_entry) + 320 strlen(namespace) + 1)); 321 strcpy(ns_entry->namespace, namespace); 322 list_add_tail(&ns_entry->list, head); 323 } 324 } 325 326 static void *sym_get_data_by_offset(const struct elf_info *info, 327 unsigned int secindex, unsigned long offset) 328 { 329 Elf_Shdr *sechdr = &info->sechdrs[secindex]; 330 331 return (void *)info->hdr + sechdr->sh_offset + offset; 332 } 333 334 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) 335 { 336 return sym_get_data_by_offset(info, get_secindex(info, sym), 337 sym->st_value); 338 } 339 340 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) 341 { 342 return sym_get_data_by_offset(info, info->secindex_strings, 343 sechdr->sh_name); 344 } 345 346 static const char *sec_name(const struct elf_info *info, unsigned int secindex) 347 { 348 /* 349 * If sym->st_shndx is a special section index, there is no 350 * corresponding section header. 351 * Return "" if the index is out of range of info->sechdrs[] array. 352 */ 353 if (secindex >= info->num_sections) 354 return ""; 355 356 return sech_name(info, &info->sechdrs[secindex]); 357 } 358 359 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) 360 361 static struct symbol *sym_add_exported(const char *name, struct module *mod, 362 bool gpl_only, const char *namespace) 363 { 364 struct symbol *s = find_symbol(name); 365 366 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { 367 error("%s: '%s' exported twice. Previous export was in %s%s\n", 368 mod->name, name, s->module->name, 369 s->module->is_vmlinux ? "" : ".ko"); 370 } 371 372 s = alloc_symbol(name); 373 s->module = mod; 374 s->is_gpl_only = gpl_only; 375 s->namespace = NOFAIL(strdup(namespace)); 376 list_add_tail(&s->list, &mod->exported_symbols); 377 hash_add_symbol(s); 378 379 return s; 380 } 381 382 static void sym_set_crc(struct symbol *sym, unsigned int crc) 383 { 384 sym->crc = crc; 385 sym->crc_valid = true; 386 } 387 388 static void *grab_file(const char *filename, size_t *size) 389 { 390 struct stat st; 391 void *map = MAP_FAILED; 392 int fd; 393 394 fd = open(filename, O_RDONLY); 395 if (fd < 0) 396 return NULL; 397 if (fstat(fd, &st)) 398 goto failed; 399 400 *size = st.st_size; 401 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 402 403 failed: 404 close(fd); 405 if (map == MAP_FAILED) 406 return NULL; 407 return map; 408 } 409 410 static void release_file(void *file, size_t size) 411 { 412 munmap(file, size); 413 } 414 415 static int parse_elf(struct elf_info *info, const char *filename) 416 { 417 unsigned int i; 418 Elf_Ehdr *hdr; 419 Elf_Shdr *sechdrs; 420 Elf_Sym *sym; 421 const char *secstrings; 422 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 423 424 hdr = grab_file(filename, &info->size); 425 if (!hdr) { 426 if (ignore_missing_files) { 427 fprintf(stderr, "%s: %s (ignored)\n", filename, 428 strerror(errno)); 429 return 0; 430 } 431 perror(filename); 432 exit(1); 433 } 434 info->hdr = hdr; 435 if (info->size < sizeof(*hdr)) { 436 /* file too small, assume this is an empty .o file */ 437 return 0; 438 } 439 /* Is this a valid ELF file? */ 440 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 441 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 442 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 443 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 444 /* Not an ELF file - silently ignore it */ 445 return 0; 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 } 523 524 if (sechdrs[i].sh_type == SHT_SYMTAB) { 525 unsigned int sh_link_idx; 526 symtab_idx = i; 527 info->symtab_start = (void *)hdr + 528 sechdrs[i].sh_offset; 529 info->symtab_stop = (void *)hdr + 530 sechdrs[i].sh_offset + sechdrs[i].sh_size; 531 sh_link_idx = sechdrs[i].sh_link; 532 info->strtab = (void *)hdr + 533 sechdrs[sh_link_idx].sh_offset; 534 } 535 536 /* 32bit section no. table? ("more than 64k sections") */ 537 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 538 symtab_shndx_idx = i; 539 info->symtab_shndx_start = (void *)hdr + 540 sechdrs[i].sh_offset; 541 info->symtab_shndx_stop = (void *)hdr + 542 sechdrs[i].sh_offset + sechdrs[i].sh_size; 543 } 544 } 545 if (!info->symtab_start) 546 fatal("%s has no symtab?\n", filename); 547 548 /* Fix endianness in symbols */ 549 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 550 sym->st_shndx = TO_NATIVE(sym->st_shndx); 551 sym->st_name = TO_NATIVE(sym->st_name); 552 sym->st_value = TO_NATIVE(sym->st_value); 553 sym->st_size = TO_NATIVE(sym->st_size); 554 } 555 556 if (symtab_shndx_idx != ~0U) { 557 Elf32_Word *p; 558 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 559 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 560 filename, sechdrs[symtab_shndx_idx].sh_link, 561 symtab_idx); 562 /* Fix endianness */ 563 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 564 p++) 565 *p = TO_NATIVE(*p); 566 } 567 568 symsearch_init(info); 569 570 return 1; 571 } 572 573 static void parse_elf_finish(struct elf_info *info) 574 { 575 symsearch_finish(info); 576 release_file(info->hdr, info->size); 577 } 578 579 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 580 { 581 /* ignore __this_module, it will be resolved shortly */ 582 if (strcmp(symname, "__this_module") == 0) 583 return 1; 584 /* ignore global offset table */ 585 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 586 return 1; 587 if (info->hdr->e_machine == EM_PPC) 588 /* Special register function linked on all modules during final link of .ko */ 589 if (strstarts(symname, "_restgpr_") || 590 strstarts(symname, "_savegpr_") || 591 strstarts(symname, "_rest32gpr_") || 592 strstarts(symname, "_save32gpr_") || 593 strstarts(symname, "_restvr_") || 594 strstarts(symname, "_savevr_")) 595 return 1; 596 if (info->hdr->e_machine == EM_PPC64) 597 /* Special register function linked on all modules during final link of .ko */ 598 if (strstarts(symname, "_restgpr0_") || 599 strstarts(symname, "_savegpr0_") || 600 strstarts(symname, "_restvr_") || 601 strstarts(symname, "_savevr_") || 602 strcmp(symname, ".TOC.") == 0) 603 return 1; 604 /* Do not ignore this symbol */ 605 return 0; 606 } 607 608 static void handle_symbol(struct module *mod, struct elf_info *info, 609 const Elf_Sym *sym, const char *symname) 610 { 611 switch (sym->st_shndx) { 612 case SHN_COMMON: 613 if (strstarts(symname, "__gnu_lto_")) { 614 /* Should warn here, but modpost runs before the linker */ 615 } else 616 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 617 break; 618 case SHN_UNDEF: 619 /* undefined symbol */ 620 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 621 ELF_ST_BIND(sym->st_info) != STB_WEAK) 622 break; 623 if (ignore_undef_symbol(info, symname)) 624 break; 625 if (info->hdr->e_machine == EM_SPARC || 626 info->hdr->e_machine == EM_SPARCV9) { 627 /* Ignore register directives. */ 628 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 629 break; 630 if (symname[0] == '.') { 631 char *munged = NOFAIL(strdup(symname)); 632 munged[0] = '_'; 633 munged[1] = toupper(munged[1]); 634 symname = munged; 635 } 636 } 637 638 sym_add_unresolved(symname, mod, 639 ELF_ST_BIND(sym->st_info) == STB_WEAK); 640 break; 641 default: 642 if (strcmp(symname, "init_module") == 0) 643 mod->has_init = true; 644 if (strcmp(symname, "cleanup_module") == 0) 645 mod->has_cleanup = true; 646 break; 647 } 648 } 649 650 /** 651 * Parse tag=value strings from .modinfo section 652 **/ 653 static char *next_string(char *string, unsigned long *secsize) 654 { 655 /* Skip non-zero chars */ 656 while (string[0]) { 657 string++; 658 if ((*secsize)-- <= 1) 659 return NULL; 660 } 661 662 /* Skip any zero padding. */ 663 while (!string[0]) { 664 string++; 665 if ((*secsize)-- <= 1) 666 return NULL; 667 } 668 return string; 669 } 670 671 static char *get_next_modinfo(struct elf_info *info, const char *tag, 672 char *prev) 673 { 674 char *p; 675 unsigned int taglen = strlen(tag); 676 char *modinfo = info->modinfo; 677 unsigned long size = info->modinfo_len; 678 679 if (prev) { 680 size -= prev - modinfo; 681 modinfo = next_string(prev, &size); 682 } 683 684 for (p = modinfo; p; p = next_string(p, &size)) { 685 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 686 return p + taglen + 1; 687 } 688 return NULL; 689 } 690 691 static char *get_modinfo(struct elf_info *info, const char *tag) 692 693 { 694 return get_next_modinfo(info, tag, NULL); 695 } 696 697 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 698 { 699 if (sym) 700 return elf->strtab + sym->st_name; 701 else 702 return "(unknown)"; 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", ".meminit.rodata", \ 780 ".init.data", ".meminit.data" 781 782 #define ALL_PCI_INIT_SECTIONS \ 783 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 784 ".pci_fixup_enable", ".pci_fixup_resume", \ 785 ".pci_fixup_resume_early", ".pci_fixup_suspend" 786 787 #define ALL_XXXINIT_SECTIONS ".meminit.*" 788 789 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 790 #define ALL_EXIT_SECTIONS ".exit.*" 791 792 #define DATA_SECTIONS ".data", ".data.rel" 793 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ 794 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \ 795 ".ltext", ".ltext.*" 796 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ 797 ".fixup", ".entry.text", ".exception.text", \ 798 ".coldtext", ".softirqentry.text" 799 800 #define INIT_SECTIONS ".init.*" 801 802 #define ALL_TEXT_SECTIONS ".init.text", ".meminit.text", ".exit.text", \ 803 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 804 805 enum mismatch { 806 TEXTDATA_TO_ANY_INIT_EXIT, 807 XXXINIT_TO_SOME_INIT, 808 ANY_INIT_TO_ANY_EXIT, 809 ANY_EXIT_TO_ANY_INIT, 810 EXTABLE_TO_NON_TEXT, 811 }; 812 813 /** 814 * Describe how to match sections on different criteria: 815 * 816 * @fromsec: Array of sections to be matched. 817 * 818 * @bad_tosec: Relocations applied to a section in @fromsec to a section in 819 * this array is forbidden (black-list). Can be empty. 820 * 821 * @good_tosec: Relocations applied to a section in @fromsec must be 822 * targeting sections in this array (white-list). Can be empty. 823 * 824 * @mismatch: Type of mismatch. 825 */ 826 struct sectioncheck { 827 const char *fromsec[20]; 828 const char *bad_tosec[20]; 829 const char *good_tosec[20]; 830 enum mismatch mismatch; 831 }; 832 833 static const struct sectioncheck sectioncheck[] = { 834 /* Do not reference init/exit code/data from 835 * normal code and data 836 */ 837 { 838 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 839 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }, 840 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT, 841 }, 842 /* Do not reference init code/data from meminit code/data */ 843 { 844 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 845 .bad_tosec = { INIT_SECTIONS, NULL }, 846 .mismatch = XXXINIT_TO_SOME_INIT, 847 }, 848 /* Do not use exit code/data from init code */ 849 { 850 .fromsec = { ALL_INIT_SECTIONS, NULL }, 851 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 852 .mismatch = ANY_INIT_TO_ANY_EXIT, 853 }, 854 /* Do not use init code/data from exit code */ 855 { 856 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 857 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 858 .mismatch = ANY_EXIT_TO_ANY_INIT, 859 }, 860 { 861 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 862 .bad_tosec = { INIT_SECTIONS, NULL }, 863 .mismatch = ANY_INIT_TO_ANY_EXIT, 864 }, 865 { 866 .fromsec = { "__ex_table", NULL }, 867 /* If you're adding any new black-listed sections in here, consider 868 * adding a special 'printer' for them in scripts/check_extable. 869 */ 870 .bad_tosec = { ".altinstr_replacement", NULL }, 871 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 872 .mismatch = EXTABLE_TO_NON_TEXT, 873 } 874 }; 875 876 static const struct sectioncheck *section_mismatch( 877 const char *fromsec, const char *tosec) 878 { 879 int i; 880 881 /* 882 * The target section could be the SHT_NUL section when we're 883 * handling relocations to un-resolved symbols, trying to match it 884 * doesn't make much sense and causes build failures on parisc 885 * architectures. 886 */ 887 if (*tosec == '\0') 888 return NULL; 889 890 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 891 const struct sectioncheck *check = §ioncheck[i]; 892 893 if (match(fromsec, check->fromsec)) { 894 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 895 return check; 896 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 897 return check; 898 } 899 } 900 return NULL; 901 } 902 903 /** 904 * Whitelist to allow certain references to pass with no warning. 905 * 906 * Pattern 1: 907 * If a module parameter is declared __initdata and permissions=0 908 * then this is legal despite the warning generated. 909 * We cannot see value of permissions here, so just ignore 910 * this pattern. 911 * The pattern is identified by: 912 * tosec = .init.data 913 * fromsec = .data* 914 * atsym =__param* 915 * 916 * Pattern 1a: 917 * module_param_call() ops can refer to __init set function if permissions=0 918 * The pattern is identified by: 919 * tosec = .init.text 920 * fromsec = .data* 921 * atsym = __param_ops_* 922 * 923 * Pattern 3: 924 * Whitelist all references from .head.text to any init section 925 * 926 * Pattern 4: 927 * Some symbols belong to init section but still it is ok to reference 928 * these from non-init sections as these symbols don't have any memory 929 * allocated for them and symbol address and value are same. So even 930 * if init section is freed, its ok to reference those symbols. 931 * For ex. symbols marking the init section boundaries. 932 * This pattern is identified by 933 * refsymname = __init_begin, _sinittext, _einittext 934 * 935 * Pattern 5: 936 * GCC may optimize static inlines when fed constant arg(s) resulting 937 * in functions like cpumask_empty() -- generating an associated symbol 938 * cpumask_empty.constprop.3 that appears in the audit. If the const that 939 * is passed in comes from __init, like say nmi_ipi_mask, we get a 940 * meaningless section warning. May need to add isra symbols too... 941 * This pattern is identified by 942 * tosec = init section 943 * fromsec = text section 944 * refsymname = *.constprop.* 945 * 946 **/ 947 static int secref_whitelist(const char *fromsec, const char *fromsym, 948 const char *tosec, const char *tosym) 949 { 950 /* Check for pattern 1 */ 951 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 952 match(fromsec, PATTERNS(DATA_SECTIONS)) && 953 strstarts(fromsym, "__param")) 954 return 0; 955 956 /* Check for pattern 1a */ 957 if (strcmp(tosec, ".init.text") == 0 && 958 match(fromsec, PATTERNS(DATA_SECTIONS)) && 959 strstarts(fromsym, "__param_ops_")) 960 return 0; 961 962 /* symbols in data sections that may refer to any init/exit sections */ 963 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 964 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 965 match(fromsym, PATTERNS("*_ops", "*_probe", "*_console"))) 966 return 0; 967 968 /* 969 * symbols in data sections must not refer to .exit.*, but there are 970 * quite a few offenders, so hide these unless for W=1 builds until 971 * these are fixed. 972 */ 973 if (!extra_warn && 974 match(fromsec, PATTERNS(DATA_SECTIONS)) && 975 match(tosec, PATTERNS(ALL_EXIT_SECTIONS)) && 976 match(fromsym, PATTERNS("*driver"))) 977 return 0; 978 979 /* Check for pattern 3 */ 980 if (strstarts(fromsec, ".head.text") && 981 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 982 return 0; 983 984 /* Check for pattern 4 */ 985 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 986 return 0; 987 988 /* Check for pattern 5 */ 989 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 990 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 991 match(fromsym, PATTERNS("*.constprop.*"))) 992 return 0; 993 994 return 1; 995 } 996 997 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 998 unsigned int secndx) 999 { 1000 return symsearch_find_nearest(elf, addr, secndx, false, ~0); 1001 } 1002 1003 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 1004 { 1005 Elf_Sym *new_sym; 1006 1007 /* If the supplied symbol has a valid name, return it */ 1008 if (is_valid_name(elf, sym)) 1009 return sym; 1010 1011 /* 1012 * Strive to find a better symbol name, but the resulting name may not 1013 * match the symbol referenced in the original code. 1014 */ 1015 new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym), 1016 true, 20); 1017 return new_sym ? new_sym : sym; 1018 } 1019 1020 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1021 { 1022 if (secndx >= elf->num_sections) 1023 return false; 1024 1025 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1026 } 1027 1028 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1029 const struct sectioncheck* const mismatch, 1030 Elf_Sym *tsym, 1031 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1032 const char *tosec, Elf_Addr taddr) 1033 { 1034 Elf_Sym *from; 1035 const char *tosym; 1036 const char *fromsym; 1037 1038 from = find_fromsym(elf, faddr, fsecndx); 1039 fromsym = sym_name(elf, from); 1040 1041 tsym = find_tosym(elf, taddr, tsym); 1042 tosym = sym_name(elf, tsym); 1043 1044 /* check whitelist - we may ignore it */ 1045 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1046 return; 1047 1048 sec_mismatch_count++; 1049 1050 warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n", 1051 modname, fromsym, 1052 (unsigned int)(faddr - (from ? from->st_value : 0)), 1053 fromsec, tosym, tosec); 1054 1055 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1056 if (match(tosec, mismatch->bad_tosec)) 1057 fatal("The relocation at %s+0x%lx references\n" 1058 "section \"%s\" which is black-listed.\n" 1059 "Something is seriously wrong and should be fixed.\n" 1060 "You might get more information about where this is\n" 1061 "coming from by using scripts/check_extable.sh %s\n", 1062 fromsec, (long)faddr, tosec, modname); 1063 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1064 warn("The relocation at %s+0x%lx references\n" 1065 "section \"%s\" which is not in the list of\n" 1066 "authorized sections. If you're adding a new section\n" 1067 "and/or if this reference is valid, add \"%s\" to the\n" 1068 "list of authorized sections to jump to on fault.\n" 1069 "This can be achieved by adding \"%s\" to\n" 1070 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1071 fromsec, (long)faddr, tosec, tosec, tosec); 1072 else 1073 error("%s+0x%lx references non-executable section '%s'\n", 1074 fromsec, (long)faddr, tosec); 1075 } 1076 } 1077 1078 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1079 Elf_Addr faddr, const char *secname, 1080 Elf_Sym *sym) 1081 { 1082 static const char *prefix = "__export_symbol_"; 1083 const char *label_name, *name, *data; 1084 Elf_Sym *label; 1085 struct symbol *s; 1086 bool is_gpl; 1087 1088 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1089 label_name = sym_name(elf, label); 1090 1091 if (!strstarts(label_name, prefix)) { 1092 error("%s: .export_symbol section contains strange symbol '%s'\n", 1093 mod->name, label_name); 1094 return; 1095 } 1096 1097 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1098 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1099 error("%s: local symbol '%s' was exported\n", mod->name, 1100 label_name + strlen(prefix)); 1101 return; 1102 } 1103 1104 name = sym_name(elf, sym); 1105 if (strcmp(label_name + strlen(prefix), name)) { 1106 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1107 mod->name, name); 1108 return; 1109 } 1110 1111 data = sym_get_data(elf, label); /* license */ 1112 if (!strcmp(data, "GPL")) { 1113 is_gpl = true; 1114 } else if (!strcmp(data, "")) { 1115 is_gpl = false; 1116 } else { 1117 error("%s: unknown license '%s' was specified for '%s'\n", 1118 mod->name, data, name); 1119 return; 1120 } 1121 1122 data += strlen(data) + 1; /* namespace */ 1123 s = sym_add_exported(name, mod, is_gpl, data); 1124 1125 /* 1126 * We need to be aware whether we are exporting a function or 1127 * a data on some architectures. 1128 */ 1129 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1130 1131 /* 1132 * For parisc64, symbols prefixed $$ from the library have the symbol type 1133 * STT_LOPROC. They should be handled as functions too. 1134 */ 1135 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1136 elf->hdr->e_machine == EM_PARISC && 1137 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1138 s->is_func = true; 1139 1140 if (match(secname, PATTERNS(ALL_INIT_SECTIONS))) 1141 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1142 mod->name, name); 1143 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS))) 1144 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1145 mod->name, name); 1146 } 1147 1148 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1149 Elf_Sym *sym, 1150 unsigned int fsecndx, const char *fromsec, 1151 Elf_Addr faddr, Elf_Addr taddr) 1152 { 1153 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1154 const struct sectioncheck *mismatch; 1155 1156 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1157 check_export_symbol(mod, elf, faddr, tosec, sym); 1158 return; 1159 } 1160 1161 mismatch = section_mismatch(fromsec, tosec); 1162 if (!mismatch) 1163 return; 1164 1165 default_mismatch_handler(mod->name, elf, mismatch, sym, 1166 fsecndx, fromsec, faddr, 1167 tosec, taddr); 1168 } 1169 1170 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1171 { 1172 switch (r_type) { 1173 case R_386_32: 1174 return TO_NATIVE(*location); 1175 case R_386_PC32: 1176 return TO_NATIVE(*location) + 4; 1177 } 1178 1179 return (Elf_Addr)(-1); 1180 } 1181 1182 #ifndef R_ARM_CALL 1183 #define R_ARM_CALL 28 1184 #endif 1185 #ifndef R_ARM_JUMP24 1186 #define R_ARM_JUMP24 29 1187 #endif 1188 1189 #ifndef R_ARM_THM_CALL 1190 #define R_ARM_THM_CALL 10 1191 #endif 1192 #ifndef R_ARM_THM_JUMP24 1193 #define R_ARM_THM_JUMP24 30 1194 #endif 1195 1196 #ifndef R_ARM_MOVW_ABS_NC 1197 #define R_ARM_MOVW_ABS_NC 43 1198 #endif 1199 1200 #ifndef R_ARM_MOVT_ABS 1201 #define R_ARM_MOVT_ABS 44 1202 #endif 1203 1204 #ifndef R_ARM_THM_MOVW_ABS_NC 1205 #define R_ARM_THM_MOVW_ABS_NC 47 1206 #endif 1207 1208 #ifndef R_ARM_THM_MOVT_ABS 1209 #define R_ARM_THM_MOVT_ABS 48 1210 #endif 1211 1212 #ifndef R_ARM_THM_JUMP19 1213 #define R_ARM_THM_JUMP19 51 1214 #endif 1215 1216 static int32_t sign_extend32(int32_t value, int index) 1217 { 1218 uint8_t shift = 31 - index; 1219 1220 return (int32_t)(value << shift) >> shift; 1221 } 1222 1223 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1224 { 1225 uint32_t inst, upper, lower, sign, j1, j2; 1226 int32_t offset; 1227 1228 switch (r_type) { 1229 case R_ARM_ABS32: 1230 case R_ARM_REL32: 1231 inst = TO_NATIVE(*(uint32_t *)loc); 1232 return inst + sym->st_value; 1233 case R_ARM_MOVW_ABS_NC: 1234 case R_ARM_MOVT_ABS: 1235 inst = TO_NATIVE(*(uint32_t *)loc); 1236 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1237 15); 1238 return offset + sym->st_value; 1239 case R_ARM_PC24: 1240 case R_ARM_CALL: 1241 case R_ARM_JUMP24: 1242 inst = TO_NATIVE(*(uint32_t *)loc); 1243 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1244 return offset + sym->st_value + 8; 1245 case R_ARM_THM_MOVW_ABS_NC: 1246 case R_ARM_THM_MOVT_ABS: 1247 upper = TO_NATIVE(*(uint16_t *)loc); 1248 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1249 offset = sign_extend32(((upper & 0x000f) << 12) | 1250 ((upper & 0x0400) << 1) | 1251 ((lower & 0x7000) >> 4) | 1252 (lower & 0x00ff), 1253 15); 1254 return offset + sym->st_value; 1255 case R_ARM_THM_JUMP19: 1256 /* 1257 * Encoding T3: 1258 * S = upper[10] 1259 * imm6 = upper[5:0] 1260 * J1 = lower[13] 1261 * J2 = lower[11] 1262 * imm11 = lower[10:0] 1263 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1264 */ 1265 upper = TO_NATIVE(*(uint16_t *)loc); 1266 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1267 1268 sign = (upper >> 10) & 1; 1269 j1 = (lower >> 13) & 1; 1270 j2 = (lower >> 11) & 1; 1271 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1272 ((upper & 0x03f) << 12) | 1273 ((lower & 0x07ff) << 1), 1274 20); 1275 return offset + sym->st_value + 4; 1276 case R_ARM_THM_CALL: 1277 case R_ARM_THM_JUMP24: 1278 /* 1279 * Encoding T4: 1280 * S = upper[10] 1281 * imm10 = upper[9:0] 1282 * J1 = lower[13] 1283 * J2 = lower[11] 1284 * imm11 = lower[10:0] 1285 * I1 = NOT(J1 XOR S) 1286 * I2 = NOT(J2 XOR S) 1287 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1288 */ 1289 upper = TO_NATIVE(*(uint16_t *)loc); 1290 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1291 1292 sign = (upper >> 10) & 1; 1293 j1 = (lower >> 13) & 1; 1294 j2 = (lower >> 11) & 1; 1295 offset = sign_extend32((sign << 24) | 1296 ((~(j1 ^ sign) & 1) << 23) | 1297 ((~(j2 ^ sign) & 1) << 22) | 1298 ((upper & 0x03ff) << 12) | 1299 ((lower & 0x07ff) << 1), 1300 24); 1301 return offset + sym->st_value + 4; 1302 } 1303 1304 return (Elf_Addr)(-1); 1305 } 1306 1307 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1308 { 1309 uint32_t inst; 1310 1311 inst = TO_NATIVE(*location); 1312 switch (r_type) { 1313 case R_MIPS_LO16: 1314 return inst & 0xffff; 1315 case R_MIPS_26: 1316 return (inst & 0x03ffffff) << 2; 1317 case R_MIPS_32: 1318 return inst; 1319 } 1320 return (Elf_Addr)(-1); 1321 } 1322 1323 #ifndef EM_RISCV 1324 #define EM_RISCV 243 1325 #endif 1326 1327 #ifndef R_RISCV_SUB32 1328 #define R_RISCV_SUB32 39 1329 #endif 1330 1331 #ifndef EM_LOONGARCH 1332 #define EM_LOONGARCH 258 1333 #endif 1334 1335 #ifndef R_LARCH_SUB32 1336 #define R_LARCH_SUB32 55 1337 #endif 1338 1339 #ifndef R_LARCH_RELAX 1340 #define R_LARCH_RELAX 100 1341 #endif 1342 1343 #ifndef R_LARCH_ALIGN 1344 #define R_LARCH_ALIGN 102 1345 #endif 1346 1347 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1348 unsigned int *r_type, unsigned int *r_sym) 1349 { 1350 typedef struct { 1351 Elf64_Word r_sym; /* Symbol index */ 1352 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1353 unsigned char r_type3; /* 3rd relocation type */ 1354 unsigned char r_type2; /* 2nd relocation type */ 1355 unsigned char r_type; /* 1st relocation type */ 1356 } Elf64_Mips_R_Info; 1357 1358 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1359 1360 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1361 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1362 1363 *r_type = mips64_r_info->r_type; 1364 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1365 return; 1366 } 1367 1368 if (is_64bit) 1369 r_info = TO_NATIVE((Elf64_Xword)r_info); 1370 else 1371 r_info = TO_NATIVE((Elf32_Word)r_info); 1372 1373 *r_type = ELF_R_TYPE(r_info); 1374 *r_sym = ELF_R_SYM(r_info); 1375 } 1376 1377 static void section_rela(struct module *mod, struct elf_info *elf, 1378 unsigned int fsecndx, const char *fromsec, 1379 const Elf_Rela *start, const Elf_Rela *stop) 1380 { 1381 const Elf_Rela *rela; 1382 1383 for (rela = start; rela < stop; rela++) { 1384 Elf_Sym *tsym; 1385 Elf_Addr taddr, r_offset; 1386 unsigned int r_type, r_sym; 1387 1388 r_offset = TO_NATIVE(rela->r_offset); 1389 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1390 1391 tsym = elf->symtab_start + r_sym; 1392 taddr = tsym->st_value + TO_NATIVE(rela->r_addend); 1393 1394 switch (elf->hdr->e_machine) { 1395 case EM_RISCV: 1396 if (!strcmp("__ex_table", fromsec) && 1397 r_type == R_RISCV_SUB32) 1398 continue; 1399 break; 1400 case EM_LOONGARCH: 1401 switch (r_type) { 1402 case R_LARCH_SUB32: 1403 if (!strcmp("__ex_table", fromsec)) 1404 continue; 1405 break; 1406 case R_LARCH_RELAX: 1407 case R_LARCH_ALIGN: 1408 /* These relocs do not refer to symbols */ 1409 continue; 1410 } 1411 break; 1412 } 1413 1414 check_section_mismatch(mod, elf, tsym, 1415 fsecndx, fromsec, r_offset, taddr); 1416 } 1417 } 1418 1419 static void section_rel(struct module *mod, struct elf_info *elf, 1420 unsigned int fsecndx, const char *fromsec, 1421 const Elf_Rel *start, const Elf_Rel *stop) 1422 { 1423 const Elf_Rel *rel; 1424 1425 for (rel = start; rel < stop; rel++) { 1426 Elf_Sym *tsym; 1427 Elf_Addr taddr, r_offset; 1428 unsigned int r_type, r_sym; 1429 void *loc; 1430 1431 r_offset = TO_NATIVE(rel->r_offset); 1432 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1433 1434 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1435 tsym = elf->symtab_start + r_sym; 1436 1437 switch (elf->hdr->e_machine) { 1438 case EM_386: 1439 taddr = addend_386_rel(loc, r_type); 1440 break; 1441 case EM_ARM: 1442 taddr = addend_arm_rel(loc, tsym, r_type); 1443 break; 1444 case EM_MIPS: 1445 taddr = addend_mips_rel(loc, r_type); 1446 break; 1447 default: 1448 fatal("Please add code to calculate addend for this architecture\n"); 1449 } 1450 1451 check_section_mismatch(mod, elf, tsym, 1452 fsecndx, fromsec, r_offset, taddr); 1453 } 1454 } 1455 1456 /** 1457 * A module includes a number of sections that are discarded 1458 * either when loaded or when used as built-in. 1459 * For loaded modules all functions marked __init and all data 1460 * marked __initdata will be discarded when the module has been initialized. 1461 * Likewise for modules used built-in the sections marked __exit 1462 * are discarded because __exit marked function are supposed to be called 1463 * only when a module is unloaded which never happens for built-in modules. 1464 * The check_sec_ref() function traverses all relocation records 1465 * to find all references to a section that reference a section that will 1466 * be discarded and warns about it. 1467 **/ 1468 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1469 { 1470 int i; 1471 1472 /* Walk through all sections */ 1473 for (i = 0; i < elf->num_sections; i++) { 1474 Elf_Shdr *sechdr = &elf->sechdrs[i]; 1475 1476 check_section(mod->name, elf, sechdr); 1477 /* We want to process only relocation sections and not .init */ 1478 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) { 1479 /* section to which the relocation applies */ 1480 unsigned int secndx = sechdr->sh_info; 1481 const char *secname = sec_name(elf, secndx); 1482 const void *start, *stop; 1483 1484 /* If the section is known good, skip it */ 1485 if (match(secname, section_white_list)) 1486 continue; 1487 1488 start = sym_get_data_by_offset(elf, i, 0); 1489 stop = start + sechdr->sh_size; 1490 1491 if (sechdr->sh_type == SHT_RELA) 1492 section_rela(mod, elf, secndx, secname, 1493 start, stop); 1494 else 1495 section_rel(mod, elf, secndx, secname, 1496 start, stop); 1497 } 1498 } 1499 } 1500 1501 static char *remove_dot(char *s) 1502 { 1503 size_t n = strcspn(s, "."); 1504 1505 if (n && s[n]) { 1506 size_t m = strspn(s + n + 1, "0123456789"); 1507 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1508 s[n] = 0; 1509 } 1510 return s; 1511 } 1512 1513 /* 1514 * The CRCs are recorded in .*.cmd files in the form of: 1515 * #SYMVER <name> <crc> 1516 */ 1517 static void extract_crcs_for_object(const char *object, struct module *mod) 1518 { 1519 char cmd_file[PATH_MAX]; 1520 char *buf, *p; 1521 const char *base; 1522 int dirlen, ret; 1523 1524 base = strrchr(object, '/'); 1525 if (base) { 1526 base++; 1527 dirlen = base - object; 1528 } else { 1529 dirlen = 0; 1530 base = object; 1531 } 1532 1533 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1534 dirlen, object, base); 1535 if (ret >= sizeof(cmd_file)) { 1536 error("%s: too long path was truncated\n", cmd_file); 1537 return; 1538 } 1539 1540 buf = read_text_file(cmd_file); 1541 p = buf; 1542 1543 while ((p = strstr(p, "\n#SYMVER "))) { 1544 char *name; 1545 size_t namelen; 1546 unsigned int crc; 1547 struct symbol *sym; 1548 1549 name = p + strlen("\n#SYMVER "); 1550 1551 p = strchr(name, ' '); 1552 if (!p) 1553 break; 1554 1555 namelen = p - name; 1556 p++; 1557 1558 if (!isdigit(*p)) 1559 continue; /* skip this line */ 1560 1561 crc = strtoul(p, &p, 0); 1562 if (*p != '\n') 1563 continue; /* skip this line */ 1564 1565 name[namelen] = '\0'; 1566 1567 /* 1568 * sym_find_with_module() may return NULL here. 1569 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1570 * Since commit e1327a127703, genksyms calculates CRCs of all 1571 * symbols, including trimmed ones. Ignore orphan CRCs. 1572 */ 1573 sym = sym_find_with_module(name, mod); 1574 if (sym) 1575 sym_set_crc(sym, crc); 1576 } 1577 1578 free(buf); 1579 } 1580 1581 /* 1582 * The symbol versions (CRC) are recorded in the .*.cmd files. 1583 * Parse them to retrieve CRCs for the current module. 1584 */ 1585 static void mod_set_crcs(struct module *mod) 1586 { 1587 char objlist[PATH_MAX]; 1588 char *buf, *p, *obj; 1589 int ret; 1590 1591 if (mod->is_vmlinux) { 1592 strcpy(objlist, ".vmlinux.objs"); 1593 } else { 1594 /* objects for a module are listed in the *.mod file. */ 1595 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1596 if (ret >= sizeof(objlist)) { 1597 error("%s: too long path was truncated\n", objlist); 1598 return; 1599 } 1600 } 1601 1602 buf = read_text_file(objlist); 1603 p = buf; 1604 1605 while ((obj = strsep(&p, "\n")) && obj[0]) 1606 extract_crcs_for_object(obj, mod); 1607 1608 free(buf); 1609 } 1610 1611 static void read_symbols(const char *modname) 1612 { 1613 const char *symname; 1614 char *version; 1615 char *license; 1616 char *namespace; 1617 struct module *mod; 1618 struct elf_info info = { }; 1619 Elf_Sym *sym; 1620 1621 if (!parse_elf(&info, modname)) 1622 return; 1623 1624 if (!strends(modname, ".o")) { 1625 error("%s: filename must be suffixed with .o\n", modname); 1626 return; 1627 } 1628 1629 /* strip trailing .o */ 1630 mod = new_module(modname, strlen(modname) - strlen(".o")); 1631 1632 if (!mod->is_vmlinux) { 1633 license = get_modinfo(&info, "license"); 1634 if (!license) 1635 error("missing MODULE_LICENSE() in %s\n", modname); 1636 while (license) { 1637 if (!license_is_gpl_compatible(license)) { 1638 mod->is_gpl_compatible = false; 1639 break; 1640 } 1641 license = get_next_modinfo(&info, "license", license); 1642 } 1643 1644 namespace = get_modinfo(&info, "import_ns"); 1645 while (namespace) { 1646 add_namespace(&mod->imported_namespaces, namespace); 1647 namespace = get_next_modinfo(&info, "import_ns", 1648 namespace); 1649 } 1650 1651 if (extra_warn && !get_modinfo(&info, "description")) 1652 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1653 } 1654 1655 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1656 symname = remove_dot(info.strtab + sym->st_name); 1657 1658 handle_symbol(mod, &info, sym, symname); 1659 handle_moddevtable(mod, &info, sym, symname); 1660 } 1661 1662 check_sec_ref(mod, &info); 1663 1664 if (!mod->is_vmlinux) { 1665 version = get_modinfo(&info, "version"); 1666 if (version || all_versions) 1667 get_src_version(mod->name, mod->srcversion, 1668 sizeof(mod->srcversion) - 1); 1669 } 1670 1671 parse_elf_finish(&info); 1672 1673 if (modversions) { 1674 /* 1675 * Our trick to get versioning for module struct etc. - it's 1676 * never passed as an argument to an exported function, so 1677 * the automatic versioning doesn't pick it up, but it's really 1678 * important anyhow. 1679 */ 1680 sym_add_unresolved("module_layout", mod, false); 1681 1682 mod_set_crcs(mod); 1683 } 1684 } 1685 1686 static void read_symbols_from_files(const char *filename) 1687 { 1688 FILE *in = stdin; 1689 char fname[PATH_MAX]; 1690 1691 in = fopen(filename, "r"); 1692 if (!in) 1693 fatal("Can't open filenames file %s: %m", filename); 1694 1695 while (fgets(fname, PATH_MAX, in) != NULL) { 1696 if (strends(fname, "\n")) 1697 fname[strlen(fname)-1] = '\0'; 1698 read_symbols(fname); 1699 } 1700 1701 fclose(in); 1702 } 1703 1704 #define SZ 500 1705 1706 /* We first write the generated file into memory using the 1707 * following helper, then compare to the file on disk and 1708 * only update the later if anything changed */ 1709 1710 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1711 const char *fmt, ...) 1712 { 1713 char tmp[SZ]; 1714 int len; 1715 va_list ap; 1716 1717 va_start(ap, fmt); 1718 len = vsnprintf(tmp, SZ, fmt, ap); 1719 buf_write(buf, tmp, len); 1720 va_end(ap); 1721 } 1722 1723 void buf_write(struct buffer *buf, const char *s, int len) 1724 { 1725 if (buf->size - buf->pos < len) { 1726 buf->size += len + SZ; 1727 buf->p = NOFAIL(realloc(buf->p, buf->size)); 1728 } 1729 strncpy(buf->p + buf->pos, s, len); 1730 buf->pos += len; 1731 } 1732 1733 static void check_exports(struct module *mod) 1734 { 1735 struct symbol *s, *exp; 1736 1737 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1738 const char *basename; 1739 exp = find_symbol(s->name); 1740 if (!exp) { 1741 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1742 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, 1743 "\"%s\" [%s.ko] undefined!\n", 1744 s->name, mod->name); 1745 continue; 1746 } 1747 if (exp->module == mod) { 1748 error("\"%s\" [%s.ko] was exported without definition\n", 1749 s->name, mod->name); 1750 continue; 1751 } 1752 1753 exp->used = true; 1754 s->module = exp->module; 1755 s->crc_valid = exp->crc_valid; 1756 s->crc = exp->crc; 1757 1758 basename = strrchr(mod->name, '/'); 1759 if (basename) 1760 basename++; 1761 else 1762 basename = mod->name; 1763 1764 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1765 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, 1766 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1767 basename, exp->name, exp->namespace); 1768 add_namespace(&mod->missing_namespaces, exp->namespace); 1769 } 1770 1771 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1772 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1773 basename, exp->name); 1774 } 1775 } 1776 1777 static void handle_white_list_exports(const char *white_list) 1778 { 1779 char *buf, *p, *name; 1780 1781 buf = read_text_file(white_list); 1782 p = buf; 1783 1784 while ((name = strsep(&p, "\n"))) { 1785 struct symbol *sym = find_symbol(name); 1786 1787 if (sym) 1788 sym->used = true; 1789 } 1790 1791 free(buf); 1792 } 1793 1794 static void check_modname_len(struct module *mod) 1795 { 1796 const char *mod_name; 1797 1798 mod_name = strrchr(mod->name, '/'); 1799 if (mod_name == NULL) 1800 mod_name = mod->name; 1801 else 1802 mod_name++; 1803 if (strlen(mod_name) >= MODULE_NAME_LEN) 1804 error("module name is too long [%s.ko]\n", mod->name); 1805 } 1806 1807 /** 1808 * Header for the generated file 1809 **/ 1810 static void add_header(struct buffer *b, struct module *mod) 1811 { 1812 buf_printf(b, "#include <linux/module.h>\n"); 1813 /* 1814 * Include build-salt.h after module.h in order to 1815 * inherit the definitions. 1816 */ 1817 buf_printf(b, "#define INCLUDE_VERMAGIC\n"); 1818 buf_printf(b, "#include <linux/build-salt.h>\n"); 1819 buf_printf(b, "#include <linux/elfnote-lto.h>\n"); 1820 buf_printf(b, "#include <linux/export-internal.h>\n"); 1821 buf_printf(b, "#include <linux/vermagic.h>\n"); 1822 buf_printf(b, "#include <linux/compiler.h>\n"); 1823 buf_printf(b, "\n"); 1824 buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n"); 1825 buf_printf(b, "#include <asm/orc_header.h>\n"); 1826 buf_printf(b, "ORC_HEADER;\n"); 1827 buf_printf(b, "#endif\n"); 1828 buf_printf(b, "\n"); 1829 buf_printf(b, "BUILD_SALT;\n"); 1830 buf_printf(b, "BUILD_LTO_INFO;\n"); 1831 buf_printf(b, "\n"); 1832 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1833 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1834 buf_printf(b, "\n"); 1835 buf_printf(b, "__visible struct module __this_module\n"); 1836 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1837 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1838 if (mod->has_init) 1839 buf_printf(b, "\t.init = init_module,\n"); 1840 if (mod->has_cleanup) 1841 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1842 "\t.exit = cleanup_module,\n" 1843 "#endif\n"); 1844 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1845 buf_printf(b, "};\n"); 1846 1847 if (!external_module) 1848 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1849 1850 buf_printf(b, 1851 "\n" 1852 "#ifdef CONFIG_MITIGATION_RETPOLINE\n" 1853 "MODULE_INFO(retpoline, \"Y\");\n" 1854 "#endif\n"); 1855 1856 if (strstarts(mod->name, "drivers/staging")) 1857 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1858 1859 if (strstarts(mod->name, "tools/testing")) 1860 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1861 } 1862 1863 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1864 { 1865 struct symbol *sym; 1866 1867 /* generate struct for exported symbols */ 1868 buf_printf(buf, "\n"); 1869 list_for_each_entry(sym, &mod->exported_symbols, list) { 1870 if (trim_unused_exports && !sym->used) 1871 continue; 1872 1873 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1874 sym->is_func ? "FUNC" : "DATA", sym->name, 1875 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1876 } 1877 1878 if (!modversions) 1879 return; 1880 1881 /* record CRCs for exported symbols */ 1882 buf_printf(buf, "\n"); 1883 list_for_each_entry(sym, &mod->exported_symbols, list) { 1884 if (trim_unused_exports && !sym->used) 1885 continue; 1886 1887 if (!sym->crc_valid) 1888 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1889 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1890 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1891 sym->name); 1892 1893 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1894 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1895 } 1896 } 1897 1898 /** 1899 * Record CRCs for unresolved symbols 1900 **/ 1901 static void add_versions(struct buffer *b, struct module *mod) 1902 { 1903 struct symbol *s; 1904 1905 if (!modversions) 1906 return; 1907 1908 buf_printf(b, "\n"); 1909 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1910 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1911 1912 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1913 if (!s->module) 1914 continue; 1915 if (!s->crc_valid) { 1916 warn("\"%s\" [%s.ko] has no CRC!\n", 1917 s->name, mod->name); 1918 continue; 1919 } 1920 if (strlen(s->name) >= MODULE_NAME_LEN) { 1921 error("too long symbol \"%s\" [%s.ko]\n", 1922 s->name, mod->name); 1923 break; 1924 } 1925 buf_printf(b, "\t{ %#8x, \"%s\" },\n", 1926 s->crc, s->name); 1927 } 1928 1929 buf_printf(b, "};\n"); 1930 } 1931 1932 static void add_depends(struct buffer *b, struct module *mod) 1933 { 1934 struct symbol *s; 1935 int first = 1; 1936 1937 /* Clear ->seen flag of modules that own symbols needed by this. */ 1938 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1939 if (s->module) 1940 s->module->seen = s->module->is_vmlinux; 1941 } 1942 1943 buf_printf(b, "\n"); 1944 buf_printf(b, "MODULE_INFO(depends, \""); 1945 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1946 const char *p; 1947 if (!s->module) 1948 continue; 1949 1950 if (s->module->seen) 1951 continue; 1952 1953 s->module->seen = true; 1954 p = strrchr(s->module->name, '/'); 1955 if (p) 1956 p++; 1957 else 1958 p = s->module->name; 1959 buf_printf(b, "%s%s", first ? "" : ",", p); 1960 first = 0; 1961 } 1962 buf_printf(b, "\");\n"); 1963 } 1964 1965 static void add_srcversion(struct buffer *b, struct module *mod) 1966 { 1967 if (mod->srcversion[0]) { 1968 buf_printf(b, "\n"); 1969 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1970 mod->srcversion); 1971 } 1972 } 1973 1974 static void write_buf(struct buffer *b, const char *fname) 1975 { 1976 FILE *file; 1977 1978 if (error_occurred) 1979 return; 1980 1981 file = fopen(fname, "w"); 1982 if (!file) { 1983 perror(fname); 1984 exit(1); 1985 } 1986 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1987 perror(fname); 1988 exit(1); 1989 } 1990 if (fclose(file) != 0) { 1991 perror(fname); 1992 exit(1); 1993 } 1994 } 1995 1996 static void write_if_changed(struct buffer *b, const char *fname) 1997 { 1998 char *tmp; 1999 FILE *file; 2000 struct stat st; 2001 2002 file = fopen(fname, "r"); 2003 if (!file) 2004 goto write; 2005 2006 if (fstat(fileno(file), &st) < 0) 2007 goto close_write; 2008 2009 if (st.st_size != b->pos) 2010 goto close_write; 2011 2012 tmp = NOFAIL(malloc(b->pos)); 2013 if (fread(tmp, 1, b->pos, file) != b->pos) 2014 goto free_write; 2015 2016 if (memcmp(tmp, b->p, b->pos) != 0) 2017 goto free_write; 2018 2019 free(tmp); 2020 fclose(file); 2021 return; 2022 2023 free_write: 2024 free(tmp); 2025 close_write: 2026 fclose(file); 2027 write: 2028 write_buf(b, fname); 2029 } 2030 2031 static void write_vmlinux_export_c_file(struct module *mod) 2032 { 2033 struct buffer buf = { }; 2034 2035 buf_printf(&buf, 2036 "#include <linux/export-internal.h>\n"); 2037 2038 add_exported_symbols(&buf, mod); 2039 write_if_changed(&buf, ".vmlinux.export.c"); 2040 free(buf.p); 2041 } 2042 2043 /* do sanity checks, and generate *.mod.c file */ 2044 static void write_mod_c_file(struct module *mod) 2045 { 2046 struct buffer buf = { }; 2047 char fname[PATH_MAX]; 2048 int ret; 2049 2050 add_header(&buf, mod); 2051 add_exported_symbols(&buf, mod); 2052 add_versions(&buf, mod); 2053 add_depends(&buf, mod); 2054 add_moddevtable(&buf, mod); 2055 add_srcversion(&buf, mod); 2056 2057 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2058 if (ret >= sizeof(fname)) { 2059 error("%s: too long path was truncated\n", fname); 2060 goto free; 2061 } 2062 2063 write_if_changed(&buf, fname); 2064 2065 free: 2066 free(buf.p); 2067 } 2068 2069 /* parse Module.symvers file. line format: 2070 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2071 **/ 2072 static void read_dump(const char *fname) 2073 { 2074 char *buf, *pos, *line; 2075 2076 buf = read_text_file(fname); 2077 if (!buf) 2078 /* No symbol versions, silently ignore */ 2079 return; 2080 2081 pos = buf; 2082 2083 while ((line = get_line(&pos))) { 2084 char *symname, *namespace, *modname, *d, *export; 2085 unsigned int crc; 2086 struct module *mod; 2087 struct symbol *s; 2088 bool gpl_only; 2089 2090 if (!(symname = strchr(line, '\t'))) 2091 goto fail; 2092 *symname++ = '\0'; 2093 if (!(modname = strchr(symname, '\t'))) 2094 goto fail; 2095 *modname++ = '\0'; 2096 if (!(export = strchr(modname, '\t'))) 2097 goto fail; 2098 *export++ = '\0'; 2099 if (!(namespace = strchr(export, '\t'))) 2100 goto fail; 2101 *namespace++ = '\0'; 2102 2103 crc = strtoul(line, &d, 16); 2104 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2105 goto fail; 2106 2107 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2108 gpl_only = true; 2109 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2110 gpl_only = false; 2111 } else { 2112 error("%s: unknown license %s. skip", symname, export); 2113 continue; 2114 } 2115 2116 mod = find_module(modname); 2117 if (!mod) { 2118 mod = new_module(modname, strlen(modname)); 2119 mod->from_dump = true; 2120 } 2121 s = sym_add_exported(symname, mod, gpl_only, namespace); 2122 sym_set_crc(s, crc); 2123 } 2124 free(buf); 2125 return; 2126 fail: 2127 free(buf); 2128 fatal("parse error in symbol dump file\n"); 2129 } 2130 2131 static void write_dump(const char *fname) 2132 { 2133 struct buffer buf = { }; 2134 struct module *mod; 2135 struct symbol *sym; 2136 2137 list_for_each_entry(mod, &modules, list) { 2138 if (mod->from_dump) 2139 continue; 2140 list_for_each_entry(sym, &mod->exported_symbols, list) { 2141 if (trim_unused_exports && !sym->used) 2142 continue; 2143 2144 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2145 sym->crc, sym->name, mod->name, 2146 sym->is_gpl_only ? "_GPL" : "", 2147 sym->namespace); 2148 } 2149 } 2150 write_buf(&buf, fname); 2151 free(buf.p); 2152 } 2153 2154 static void write_namespace_deps_files(const char *fname) 2155 { 2156 struct module *mod; 2157 struct namespace_list *ns; 2158 struct buffer ns_deps_buf = {}; 2159 2160 list_for_each_entry(mod, &modules, list) { 2161 2162 if (mod->from_dump || list_empty(&mod->missing_namespaces)) 2163 continue; 2164 2165 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2166 2167 list_for_each_entry(ns, &mod->missing_namespaces, list) 2168 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2169 2170 buf_printf(&ns_deps_buf, "\n"); 2171 } 2172 2173 write_if_changed(&ns_deps_buf, fname); 2174 free(ns_deps_buf.p); 2175 } 2176 2177 struct dump_list { 2178 struct list_head list; 2179 const char *file; 2180 }; 2181 2182 int main(int argc, char **argv) 2183 { 2184 struct module *mod; 2185 char *missing_namespace_deps = NULL; 2186 char *unused_exports_white_list = NULL; 2187 char *dump_write = NULL, *files_source = NULL; 2188 int opt; 2189 LIST_HEAD(dump_lists); 2190 struct dump_list *dl, *dl2; 2191 2192 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) { 2193 switch (opt) { 2194 case 'e': 2195 external_module = true; 2196 break; 2197 case 'i': 2198 dl = NOFAIL(malloc(sizeof(*dl))); 2199 dl->file = optarg; 2200 list_add_tail(&dl->list, &dump_lists); 2201 break; 2202 case 'M': 2203 module_enabled = true; 2204 break; 2205 case 'm': 2206 modversions = true; 2207 break; 2208 case 'n': 2209 ignore_missing_files = true; 2210 break; 2211 case 'o': 2212 dump_write = optarg; 2213 break; 2214 case 'a': 2215 all_versions = true; 2216 break; 2217 case 'T': 2218 files_source = optarg; 2219 break; 2220 case 't': 2221 trim_unused_exports = true; 2222 break; 2223 case 'u': 2224 unused_exports_white_list = optarg; 2225 break; 2226 case 'W': 2227 extra_warn = true; 2228 break; 2229 case 'w': 2230 warn_unresolved = true; 2231 break; 2232 case 'E': 2233 sec_mismatch_warn_only = false; 2234 break; 2235 case 'N': 2236 allow_missing_ns_imports = true; 2237 break; 2238 case 'd': 2239 missing_namespace_deps = optarg; 2240 break; 2241 default: 2242 exit(1); 2243 } 2244 } 2245 2246 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2247 read_dump(dl->file); 2248 list_del(&dl->list); 2249 free(dl); 2250 } 2251 2252 while (optind < argc) 2253 read_symbols(argv[optind++]); 2254 2255 if (files_source) 2256 read_symbols_from_files(files_source); 2257 2258 list_for_each_entry(mod, &modules, list) { 2259 if (mod->from_dump || mod->is_vmlinux) 2260 continue; 2261 2262 check_modname_len(mod); 2263 check_exports(mod); 2264 } 2265 2266 if (unused_exports_white_list) 2267 handle_white_list_exports(unused_exports_white_list); 2268 2269 list_for_each_entry(mod, &modules, list) { 2270 if (mod->from_dump) 2271 continue; 2272 2273 if (mod->is_vmlinux) 2274 write_vmlinux_export_c_file(mod); 2275 else 2276 write_mod_c_file(mod); 2277 } 2278 2279 if (missing_namespace_deps) 2280 write_namespace_deps_files(missing_namespace_deps); 2281 2282 if (dump_write) 2283 write_dump(dump_write); 2284 if (sec_mismatch_count && !sec_mismatch_warn_only) 2285 error("Section mismatches detected.\n" 2286 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2287 2288 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2289 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2290 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2291 2292 return error_occurred ? 1 : 0; 2293 } 2294