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 __attribute__((format(printf, 2, 3))) 64 modpost_log(enum loglevel loglevel, const char *fmt, ...) 65 { 66 va_list arglist; 67 68 switch (loglevel) { 69 case LOG_WARN: 70 fprintf(stderr, "WARNING: "); 71 break; 72 case LOG_ERROR: 73 fprintf(stderr, "ERROR: "); 74 break; 75 case LOG_FATAL: 76 fprintf(stderr, "FATAL: "); 77 break; 78 default: /* invalid loglevel, ignore */ 79 break; 80 } 81 82 fprintf(stderr, "modpost: "); 83 84 va_start(arglist, fmt); 85 vfprintf(stderr, fmt, arglist); 86 va_end(arglist); 87 88 if (loglevel == LOG_FATAL) 89 exit(1); 90 if (loglevel == LOG_ERROR) 91 error_occurred = true; 92 } 93 94 static inline bool strends(const char *str, const char *postfix) 95 { 96 if (strlen(str) < strlen(postfix)) 97 return false; 98 99 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; 100 } 101 102 void *do_nofail(void *ptr, const char *expr) 103 { 104 if (!ptr) 105 fatal("Memory allocation failure: %s.\n", expr); 106 107 return ptr; 108 } 109 110 char *read_text_file(const char *filename) 111 { 112 struct stat st; 113 size_t nbytes; 114 int fd; 115 char *buf; 116 117 fd = open(filename, O_RDONLY); 118 if (fd < 0) { 119 perror(filename); 120 exit(1); 121 } 122 123 if (fstat(fd, &st) < 0) { 124 perror(filename); 125 exit(1); 126 } 127 128 buf = NOFAIL(malloc(st.st_size + 1)); 129 130 nbytes = st.st_size; 131 132 while (nbytes) { 133 ssize_t bytes_read; 134 135 bytes_read = read(fd, buf, nbytes); 136 if (bytes_read < 0) { 137 perror(filename); 138 exit(1); 139 } 140 141 nbytes -= bytes_read; 142 } 143 buf[st.st_size] = '\0'; 144 145 close(fd); 146 147 return buf; 148 } 149 150 char *get_line(char **stringp) 151 { 152 char *orig = *stringp, *next; 153 154 /* do not return the unwanted extra line at EOF */ 155 if (!orig || *orig == '\0') 156 return NULL; 157 158 /* don't use strsep here, it is not available everywhere */ 159 next = strchr(orig, '\n'); 160 if (next) 161 *next++ = '\0'; 162 163 *stringp = next; 164 165 return orig; 166 } 167 168 /* A list of all modules we processed */ 169 LIST_HEAD(modules); 170 171 static struct module *find_module(const char *modname) 172 { 173 struct module *mod; 174 175 list_for_each_entry(mod, &modules, list) { 176 if (strcmp(mod->name, modname) == 0) 177 return mod; 178 } 179 return NULL; 180 } 181 182 static struct module *new_module(const char *name, size_t namelen) 183 { 184 struct module *mod; 185 186 mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1)); 187 memset(mod, 0, sizeof(*mod)); 188 189 INIT_LIST_HEAD(&mod->exported_symbols); 190 INIT_LIST_HEAD(&mod->unresolved_symbols); 191 INIT_LIST_HEAD(&mod->missing_namespaces); 192 INIT_LIST_HEAD(&mod->imported_namespaces); 193 194 memcpy(mod->name, name, namelen); 195 mod->name[namelen] = '\0'; 196 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0); 197 198 /* 199 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE() 200 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue 201 * modpost will exit wiht error anyway. 202 */ 203 mod->is_gpl_compatible = true; 204 205 list_add_tail(&mod->list, &modules); 206 207 return mod; 208 } 209 210 /* A hash of all exported symbols, 211 * struct symbol is also used for lists of unresolved symbols */ 212 213 #define SYMBOL_HASH_SIZE 1024 214 215 struct symbol { 216 struct symbol *next; 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 struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 230 231 /* This is based on the hash algorithm from gdbm, via tdb */ 232 static inline unsigned int tdb_hash(const char *name) 233 { 234 unsigned value; /* Used to compute the hash value. */ 235 unsigned i; /* Used to cycle through random values. */ 236 237 /* Set the initial value from the key size. */ 238 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++) 239 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 240 241 return (1103515243 * value + 12345); 242 } 243 244 /** 245 * Allocate a new symbols for use in the hash of exported symbols or 246 * the list of unresolved symbols per module 247 **/ 248 static struct symbol *alloc_symbol(const char *name) 249 { 250 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 251 252 memset(s, 0, sizeof(*s)); 253 strcpy(s->name, name); 254 255 return s; 256 } 257 258 /* For the hash of exported symbols */ 259 static void hash_add_symbol(struct symbol *sym) 260 { 261 unsigned int hash; 262 263 hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE; 264 sym->next = symbolhash[hash]; 265 symbolhash[hash] = sym; 266 } 267 268 static void sym_add_unresolved(const char *name, struct module *mod, bool weak) 269 { 270 struct symbol *sym; 271 272 sym = alloc_symbol(name); 273 sym->weak = weak; 274 275 list_add_tail(&sym->list, &mod->unresolved_symbols); 276 } 277 278 static struct symbol *sym_find_with_module(const char *name, struct module *mod) 279 { 280 struct symbol *s; 281 282 /* For our purposes, .foo matches foo. PPC64 needs this. */ 283 if (name[0] == '.') 284 name++; 285 286 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) { 287 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) 288 return s; 289 } 290 return NULL; 291 } 292 293 static struct symbol *find_symbol(const char *name) 294 { 295 return sym_find_with_module(name, NULL); 296 } 297 298 struct namespace_list { 299 struct list_head list; 300 char namespace[]; 301 }; 302 303 static bool contains_namespace(struct list_head *head, const char *namespace) 304 { 305 struct namespace_list *list; 306 307 /* 308 * The default namespace is null string "", which is always implicitly 309 * contained. 310 */ 311 if (!namespace[0]) 312 return true; 313 314 list_for_each_entry(list, head, list) { 315 if (!strcmp(list->namespace, namespace)) 316 return true; 317 } 318 319 return false; 320 } 321 322 static void add_namespace(struct list_head *head, const char *namespace) 323 { 324 struct namespace_list *ns_entry; 325 326 if (!contains_namespace(head, namespace)) { 327 ns_entry = NOFAIL(malloc(sizeof(*ns_entry) + 328 strlen(namespace) + 1)); 329 strcpy(ns_entry->namespace, namespace); 330 list_add_tail(&ns_entry->list, head); 331 } 332 } 333 334 static void *sym_get_data_by_offset(const struct elf_info *info, 335 unsigned int secindex, unsigned long offset) 336 { 337 Elf_Shdr *sechdr = &info->sechdrs[secindex]; 338 339 return (void *)info->hdr + sechdr->sh_offset + offset; 340 } 341 342 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) 343 { 344 return sym_get_data_by_offset(info, get_secindex(info, sym), 345 sym->st_value); 346 } 347 348 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) 349 { 350 return sym_get_data_by_offset(info, info->secindex_strings, 351 sechdr->sh_name); 352 } 353 354 static const char *sec_name(const struct elf_info *info, unsigned int secindex) 355 { 356 /* 357 * If sym->st_shndx is a special section index, there is no 358 * corresponding section header. 359 * Return "" if the index is out of range of info->sechdrs[] array. 360 */ 361 if (secindex >= info->num_sections) 362 return ""; 363 364 return sech_name(info, &info->sechdrs[secindex]); 365 } 366 367 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) 368 369 static struct symbol *sym_add_exported(const char *name, struct module *mod, 370 bool gpl_only, const char *namespace) 371 { 372 struct symbol *s = find_symbol(name); 373 374 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { 375 error("%s: '%s' exported twice. Previous export was in %s%s\n", 376 mod->name, name, s->module->name, 377 s->module->is_vmlinux ? "" : ".ko"); 378 } 379 380 s = alloc_symbol(name); 381 s->module = mod; 382 s->is_gpl_only = gpl_only; 383 s->namespace = NOFAIL(strdup(namespace)); 384 list_add_tail(&s->list, &mod->exported_symbols); 385 hash_add_symbol(s); 386 387 return s; 388 } 389 390 static void sym_set_crc(struct symbol *sym, unsigned int crc) 391 { 392 sym->crc = crc; 393 sym->crc_valid = true; 394 } 395 396 static void *grab_file(const char *filename, size_t *size) 397 { 398 struct stat st; 399 void *map = MAP_FAILED; 400 int fd; 401 402 fd = open(filename, O_RDONLY); 403 if (fd < 0) 404 return NULL; 405 if (fstat(fd, &st)) 406 goto failed; 407 408 *size = st.st_size; 409 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 410 411 failed: 412 close(fd); 413 if (map == MAP_FAILED) 414 return NULL; 415 return map; 416 } 417 418 static void release_file(void *file, size_t size) 419 { 420 munmap(file, size); 421 } 422 423 static int parse_elf(struct elf_info *info, const char *filename) 424 { 425 unsigned int i; 426 Elf_Ehdr *hdr; 427 Elf_Shdr *sechdrs; 428 Elf_Sym *sym; 429 const char *secstrings; 430 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 431 432 hdr = grab_file(filename, &info->size); 433 if (!hdr) { 434 if (ignore_missing_files) { 435 fprintf(stderr, "%s: %s (ignored)\n", filename, 436 strerror(errno)); 437 return 0; 438 } 439 perror(filename); 440 exit(1); 441 } 442 info->hdr = hdr; 443 if (info->size < sizeof(*hdr)) { 444 /* file too small, assume this is an empty .o file */ 445 return 0; 446 } 447 /* Is this a valid ELF file? */ 448 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 449 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 450 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 451 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 452 /* Not an ELF file - silently ignore it */ 453 return 0; 454 } 455 /* Fix endianness in ELF header */ 456 hdr->e_type = TO_NATIVE(hdr->e_type); 457 hdr->e_machine = TO_NATIVE(hdr->e_machine); 458 hdr->e_version = TO_NATIVE(hdr->e_version); 459 hdr->e_entry = TO_NATIVE(hdr->e_entry); 460 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 461 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 462 hdr->e_flags = TO_NATIVE(hdr->e_flags); 463 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 464 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 465 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 466 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 467 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 468 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 469 sechdrs = (void *)hdr + hdr->e_shoff; 470 info->sechdrs = sechdrs; 471 472 /* modpost only works for relocatable objects */ 473 if (hdr->e_type != ET_REL) 474 fatal("%s: not relocatable object.", filename); 475 476 /* Check if file offset is correct */ 477 if (hdr->e_shoff > info->size) { 478 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", 479 (unsigned long)hdr->e_shoff, filename, info->size); 480 return 0; 481 } 482 483 if (hdr->e_shnum == SHN_UNDEF) { 484 /* 485 * There are more than 64k sections, 486 * read count from .sh_size. 487 */ 488 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 489 } 490 else { 491 info->num_sections = hdr->e_shnum; 492 } 493 if (hdr->e_shstrndx == SHN_XINDEX) { 494 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 495 } 496 else { 497 info->secindex_strings = hdr->e_shstrndx; 498 } 499 500 /* Fix endianness in section headers */ 501 for (i = 0; i < info->num_sections; i++) { 502 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 503 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 504 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 505 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 506 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 507 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 508 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 509 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 510 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 511 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 512 } 513 /* Find symbol table. */ 514 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 515 for (i = 1; i < info->num_sections; i++) { 516 const char *secname; 517 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 518 519 if (!nobits && sechdrs[i].sh_offset > info->size) { 520 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n", 521 filename, (unsigned long)sechdrs[i].sh_offset, 522 sizeof(*hdr)); 523 return 0; 524 } 525 secname = secstrings + sechdrs[i].sh_name; 526 if (strcmp(secname, ".modinfo") == 0) { 527 if (nobits) 528 fatal("%s has NOBITS .modinfo\n", filename); 529 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 530 info->modinfo_len = sechdrs[i].sh_size; 531 } else if (!strcmp(secname, ".export_symbol")) { 532 info->export_symbol_secndx = i; 533 } 534 535 if (sechdrs[i].sh_type == SHT_SYMTAB) { 536 unsigned int sh_link_idx; 537 symtab_idx = i; 538 info->symtab_start = (void *)hdr + 539 sechdrs[i].sh_offset; 540 info->symtab_stop = (void *)hdr + 541 sechdrs[i].sh_offset + sechdrs[i].sh_size; 542 sh_link_idx = sechdrs[i].sh_link; 543 info->strtab = (void *)hdr + 544 sechdrs[sh_link_idx].sh_offset; 545 } 546 547 /* 32bit section no. table? ("more than 64k sections") */ 548 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 549 symtab_shndx_idx = i; 550 info->symtab_shndx_start = (void *)hdr + 551 sechdrs[i].sh_offset; 552 info->symtab_shndx_stop = (void *)hdr + 553 sechdrs[i].sh_offset + sechdrs[i].sh_size; 554 } 555 } 556 if (!info->symtab_start) 557 fatal("%s has no symtab?\n", filename); 558 559 /* Fix endianness in symbols */ 560 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 561 sym->st_shndx = TO_NATIVE(sym->st_shndx); 562 sym->st_name = TO_NATIVE(sym->st_name); 563 sym->st_value = TO_NATIVE(sym->st_value); 564 sym->st_size = TO_NATIVE(sym->st_size); 565 } 566 567 if (symtab_shndx_idx != ~0U) { 568 Elf32_Word *p; 569 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 570 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 571 filename, sechdrs[symtab_shndx_idx].sh_link, 572 symtab_idx); 573 /* Fix endianness */ 574 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 575 p++) 576 *p = TO_NATIVE(*p); 577 } 578 579 symsearch_init(info); 580 581 return 1; 582 } 583 584 static void parse_elf_finish(struct elf_info *info) 585 { 586 symsearch_finish(info); 587 release_file(info->hdr, info->size); 588 } 589 590 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 591 { 592 /* ignore __this_module, it will be resolved shortly */ 593 if (strcmp(symname, "__this_module") == 0) 594 return 1; 595 /* ignore global offset table */ 596 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 597 return 1; 598 if (info->hdr->e_machine == EM_PPC) 599 /* Special register function linked on all modules during final link of .ko */ 600 if (strstarts(symname, "_restgpr_") || 601 strstarts(symname, "_savegpr_") || 602 strstarts(symname, "_rest32gpr_") || 603 strstarts(symname, "_save32gpr_") || 604 strstarts(symname, "_restvr_") || 605 strstarts(symname, "_savevr_")) 606 return 1; 607 if (info->hdr->e_machine == EM_PPC64) 608 /* Special register function linked on all modules during final link of .ko */ 609 if (strstarts(symname, "_restgpr0_") || 610 strstarts(symname, "_savegpr0_") || 611 strstarts(symname, "_restvr_") || 612 strstarts(symname, "_savevr_") || 613 strcmp(symname, ".TOC.") == 0) 614 return 1; 615 616 if (info->hdr->e_machine == EM_S390) 617 /* Expoline thunks are linked on all kernel modules during final link of .ko */ 618 if (strstarts(symname, "__s390_indirect_jump_r")) 619 return 1; 620 /* Do not ignore this symbol */ 621 return 0; 622 } 623 624 static void handle_symbol(struct module *mod, struct elf_info *info, 625 const Elf_Sym *sym, const char *symname) 626 { 627 switch (sym->st_shndx) { 628 case SHN_COMMON: 629 if (strstarts(symname, "__gnu_lto_")) { 630 /* Should warn here, but modpost runs before the linker */ 631 } else 632 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 633 break; 634 case SHN_UNDEF: 635 /* undefined symbol */ 636 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 637 ELF_ST_BIND(sym->st_info) != STB_WEAK) 638 break; 639 if (ignore_undef_symbol(info, symname)) 640 break; 641 if (info->hdr->e_machine == EM_SPARC || 642 info->hdr->e_machine == EM_SPARCV9) { 643 /* Ignore register directives. */ 644 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 645 break; 646 if (symname[0] == '.') { 647 char *munged = NOFAIL(strdup(symname)); 648 munged[0] = '_'; 649 munged[1] = toupper(munged[1]); 650 symname = munged; 651 } 652 } 653 654 sym_add_unresolved(symname, mod, 655 ELF_ST_BIND(sym->st_info) == STB_WEAK); 656 break; 657 default: 658 if (strcmp(symname, "init_module") == 0) 659 mod->has_init = true; 660 if (strcmp(symname, "cleanup_module") == 0) 661 mod->has_cleanup = true; 662 break; 663 } 664 } 665 666 /** 667 * Parse tag=value strings from .modinfo section 668 **/ 669 static char *next_string(char *string, unsigned long *secsize) 670 { 671 /* Skip non-zero chars */ 672 while (string[0]) { 673 string++; 674 if ((*secsize)-- <= 1) 675 return NULL; 676 } 677 678 /* Skip any zero padding. */ 679 while (!string[0]) { 680 string++; 681 if ((*secsize)-- <= 1) 682 return NULL; 683 } 684 return string; 685 } 686 687 static char *get_next_modinfo(struct elf_info *info, const char *tag, 688 char *prev) 689 { 690 char *p; 691 unsigned int taglen = strlen(tag); 692 char *modinfo = info->modinfo; 693 unsigned long size = info->modinfo_len; 694 695 if (prev) { 696 size -= prev - modinfo; 697 modinfo = next_string(prev, &size); 698 } 699 700 for (p = modinfo; p; p = next_string(p, &size)) { 701 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 702 return p + taglen + 1; 703 } 704 return NULL; 705 } 706 707 static char *get_modinfo(struct elf_info *info, const char *tag) 708 709 { 710 return get_next_modinfo(info, tag, NULL); 711 } 712 713 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 714 { 715 if (sym) 716 return elf->strtab + sym->st_name; 717 else 718 return "(unknown)"; 719 } 720 721 /* 722 * Check whether the 'string' argument matches one of the 'patterns', 723 * an array of shell wildcard patterns (glob). 724 * 725 * Return true is there is a match. 726 */ 727 static bool match(const char *string, const char *const patterns[]) 728 { 729 const char *pattern; 730 731 while ((pattern = *patterns++)) { 732 if (!fnmatch(pattern, string, 0)) 733 return true; 734 } 735 736 return false; 737 } 738 739 /* useful to pass patterns to match() directly */ 740 #define PATTERNS(...) \ 741 ({ \ 742 static const char *const patterns[] = {__VA_ARGS__, NULL}; \ 743 patterns; \ 744 }) 745 746 /* sections that we do not want to do full section mismatch check on */ 747 static const char *const section_white_list[] = 748 { 749 ".comment*", 750 ".debug*", 751 ".zdebug*", /* Compressed debug sections. */ 752 ".GCC.command.line", /* record-gcc-switches */ 753 ".mdebug*", /* alpha, score, mips etc. */ 754 ".pdr", /* alpha, score, mips etc. */ 755 ".stab*", 756 ".note*", 757 ".got*", 758 ".toc*", 759 ".xt.prop", /* xtensa */ 760 ".xt.lit", /* xtensa */ 761 ".arcextmap*", /* arc */ 762 ".gnu.linkonce.arcext*", /* arc : modules */ 763 ".cmem*", /* EZchip */ 764 ".fmt_slot*", /* EZchip */ 765 ".gnu.lto*", 766 ".discard.*", 767 ".llvm.call-graph-profile", /* call graph */ 768 NULL 769 }; 770 771 /* 772 * This is used to find sections missing the SHF_ALLOC flag. 773 * The cause of this is often a section specified in assembler 774 * without "ax" / "aw". 775 */ 776 static void check_section(const char *modname, struct elf_info *elf, 777 Elf_Shdr *sechdr) 778 { 779 const char *sec = sech_name(elf, sechdr); 780 781 if (sechdr->sh_type == SHT_PROGBITS && 782 !(sechdr->sh_flags & SHF_ALLOC) && 783 !match(sec, section_white_list)) { 784 warn("%s (%s): unexpected non-allocatable section.\n" 785 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 786 "Note that for example <linux/init.h> contains\n" 787 "section definitions for use in .S files.\n\n", 788 modname, sec); 789 } 790 } 791 792 793 794 #define ALL_INIT_DATA_SECTIONS \ 795 ".init.setup", ".init.rodata", ".meminit.rodata", \ 796 ".init.data", ".meminit.data" 797 798 #define ALL_PCI_INIT_SECTIONS \ 799 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 800 ".pci_fixup_enable", ".pci_fixup_resume", \ 801 ".pci_fixup_resume_early", ".pci_fixup_suspend" 802 803 #define ALL_XXXINIT_SECTIONS ".meminit.*" 804 805 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 806 #define ALL_EXIT_SECTIONS ".exit.*" 807 808 #define DATA_SECTIONS ".data", ".data.rel" 809 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ 810 ".kprobes.text", ".cpuidle.text", ".noinstr.text" 811 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ 812 ".fixup", ".entry.text", ".exception.text", \ 813 ".coldtext", ".softirqentry.text" 814 815 #define INIT_SECTIONS ".init.*" 816 817 #define ALL_TEXT_SECTIONS ".init.text", ".meminit.text", ".exit.text", \ 818 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 819 820 enum mismatch { 821 TEXTDATA_TO_ANY_INIT_EXIT, 822 XXXINIT_TO_SOME_INIT, 823 ANY_INIT_TO_ANY_EXIT, 824 ANY_EXIT_TO_ANY_INIT, 825 EXTABLE_TO_NON_TEXT, 826 }; 827 828 /** 829 * Describe how to match sections on different criteria: 830 * 831 * @fromsec: Array of sections to be matched. 832 * 833 * @bad_tosec: Relocations applied to a section in @fromsec to a section in 834 * this array is forbidden (black-list). Can be empty. 835 * 836 * @good_tosec: Relocations applied to a section in @fromsec must be 837 * targeting sections in this array (white-list). Can be empty. 838 * 839 * @mismatch: Type of mismatch. 840 */ 841 struct sectioncheck { 842 const char *fromsec[20]; 843 const char *bad_tosec[20]; 844 const char *good_tosec[20]; 845 enum mismatch mismatch; 846 }; 847 848 static const struct sectioncheck sectioncheck[] = { 849 /* Do not reference init/exit code/data from 850 * normal code and data 851 */ 852 { 853 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 854 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }, 855 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT, 856 }, 857 /* Do not reference init code/data from meminit code/data */ 858 { 859 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 860 .bad_tosec = { INIT_SECTIONS, NULL }, 861 .mismatch = XXXINIT_TO_SOME_INIT, 862 }, 863 /* Do not use exit code/data from init code */ 864 { 865 .fromsec = { ALL_INIT_SECTIONS, NULL }, 866 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 867 .mismatch = ANY_INIT_TO_ANY_EXIT, 868 }, 869 /* Do not use init code/data from exit code */ 870 { 871 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 872 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 873 .mismatch = ANY_EXIT_TO_ANY_INIT, 874 }, 875 { 876 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 877 .bad_tosec = { INIT_SECTIONS, NULL }, 878 .mismatch = ANY_INIT_TO_ANY_EXIT, 879 }, 880 { 881 .fromsec = { "__ex_table", NULL }, 882 /* If you're adding any new black-listed sections in here, consider 883 * adding a special 'printer' for them in scripts/check_extable. 884 */ 885 .bad_tosec = { ".altinstr_replacement", NULL }, 886 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 887 .mismatch = EXTABLE_TO_NON_TEXT, 888 } 889 }; 890 891 static const struct sectioncheck *section_mismatch( 892 const char *fromsec, const char *tosec) 893 { 894 int i; 895 896 /* 897 * The target section could be the SHT_NUL section when we're 898 * handling relocations to un-resolved symbols, trying to match it 899 * doesn't make much sense and causes build failures on parisc 900 * architectures. 901 */ 902 if (*tosec == '\0') 903 return NULL; 904 905 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 906 const struct sectioncheck *check = §ioncheck[i]; 907 908 if (match(fromsec, check->fromsec)) { 909 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 910 return check; 911 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 912 return check; 913 } 914 } 915 return NULL; 916 } 917 918 /** 919 * Whitelist to allow certain references to pass with no warning. 920 * 921 * Pattern 1: 922 * If a module parameter is declared __initdata and permissions=0 923 * then this is legal despite the warning generated. 924 * We cannot see value of permissions here, so just ignore 925 * this pattern. 926 * The pattern is identified by: 927 * tosec = .init.data 928 * fromsec = .data* 929 * atsym =__param* 930 * 931 * Pattern 1a: 932 * module_param_call() ops can refer to __init set function if permissions=0 933 * The pattern is identified by: 934 * tosec = .init.text 935 * fromsec = .data* 936 * atsym = __param_ops_* 937 * 938 * Pattern 3: 939 * Whitelist all references from .head.text to any init section 940 * 941 * Pattern 4: 942 * Some symbols belong to init section but still it is ok to reference 943 * these from non-init sections as these symbols don't have any memory 944 * allocated for them and symbol address and value are same. So even 945 * if init section is freed, its ok to reference those symbols. 946 * For ex. symbols marking the init section boundaries. 947 * This pattern is identified by 948 * refsymname = __init_begin, _sinittext, _einittext 949 * 950 * Pattern 5: 951 * GCC may optimize static inlines when fed constant arg(s) resulting 952 * in functions like cpumask_empty() -- generating an associated symbol 953 * cpumask_empty.constprop.3 that appears in the audit. If the const that 954 * is passed in comes from __init, like say nmi_ipi_mask, we get a 955 * meaningless section warning. May need to add isra symbols too... 956 * This pattern is identified by 957 * tosec = init section 958 * fromsec = text section 959 * refsymname = *.constprop.* 960 * 961 **/ 962 static int secref_whitelist(const char *fromsec, const char *fromsym, 963 const char *tosec, const char *tosym) 964 { 965 /* Check for pattern 1 */ 966 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 967 match(fromsec, PATTERNS(DATA_SECTIONS)) && 968 strstarts(fromsym, "__param")) 969 return 0; 970 971 /* Check for pattern 1a */ 972 if (strcmp(tosec, ".init.text") == 0 && 973 match(fromsec, PATTERNS(DATA_SECTIONS)) && 974 strstarts(fromsym, "__param_ops_")) 975 return 0; 976 977 /* symbols in data sections that may refer to any init/exit sections */ 978 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 979 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 980 match(fromsym, PATTERNS("*_ops", "*_probe", "*_console"))) 981 return 0; 982 983 /* 984 * symbols in data sections must not refer to .exit.*, but there are 985 * quite a few offenders, so hide these unless for W=1 builds until 986 * these are fixed. 987 */ 988 if (!extra_warn && 989 match(fromsec, PATTERNS(DATA_SECTIONS)) && 990 match(tosec, PATTERNS(ALL_EXIT_SECTIONS)) && 991 match(fromsym, PATTERNS("*driver"))) 992 return 0; 993 994 /* Check for pattern 3 */ 995 if (strstarts(fromsec, ".head.text") && 996 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 997 return 0; 998 999 /* Check for pattern 4 */ 1000 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 1001 return 0; 1002 1003 /* Check for pattern 5 */ 1004 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 1005 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 1006 match(fromsym, PATTERNS("*.constprop.*"))) 1007 return 0; 1008 1009 return 1; 1010 } 1011 1012 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 1013 unsigned int secndx) 1014 { 1015 return symsearch_find_nearest(elf, addr, secndx, false, ~0); 1016 } 1017 1018 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 1019 { 1020 /* If the supplied symbol has a valid name, return it */ 1021 if (is_valid_name(elf, sym)) 1022 return sym; 1023 1024 /* 1025 * Strive to find a better symbol name, but the resulting name may not 1026 * match the symbol referenced in the original code. 1027 */ 1028 return symsearch_find_nearest(elf, addr, get_secindex(elf, sym), 1029 true, 20); 1030 } 1031 1032 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1033 { 1034 if (secndx >= elf->num_sections) 1035 return false; 1036 1037 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1038 } 1039 1040 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1041 const struct sectioncheck* const mismatch, 1042 Elf_Sym *tsym, 1043 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1044 const char *tosec, Elf_Addr taddr) 1045 { 1046 Elf_Sym *from; 1047 const char *tosym; 1048 const char *fromsym; 1049 1050 from = find_fromsym(elf, faddr, fsecndx); 1051 fromsym = sym_name(elf, from); 1052 1053 tsym = find_tosym(elf, taddr, tsym); 1054 tosym = sym_name(elf, tsym); 1055 1056 /* check whitelist - we may ignore it */ 1057 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1058 return; 1059 1060 sec_mismatch_count++; 1061 1062 warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n", 1063 modname, fromsym, (unsigned int)(faddr - from->st_value), fromsec, tosym, tosec); 1064 1065 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1066 if (match(tosec, mismatch->bad_tosec)) 1067 fatal("The relocation at %s+0x%lx references\n" 1068 "section \"%s\" which is black-listed.\n" 1069 "Something is seriously wrong and should be fixed.\n" 1070 "You might get more information about where this is\n" 1071 "coming from by using scripts/check_extable.sh %s\n", 1072 fromsec, (long)faddr, tosec, modname); 1073 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1074 warn("The relocation at %s+0x%lx references\n" 1075 "section \"%s\" which is not in the list of\n" 1076 "authorized sections. If you're adding a new section\n" 1077 "and/or if this reference is valid, add \"%s\" to the\n" 1078 "list of authorized sections to jump to on fault.\n" 1079 "This can be achieved by adding \"%s\" to\n" 1080 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1081 fromsec, (long)faddr, tosec, tosec, tosec); 1082 else 1083 error("%s+0x%lx references non-executable section '%s'\n", 1084 fromsec, (long)faddr, tosec); 1085 } 1086 } 1087 1088 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1089 Elf_Addr faddr, const char *secname, 1090 Elf_Sym *sym) 1091 { 1092 static const char *prefix = "__export_symbol_"; 1093 const char *label_name, *name, *data; 1094 Elf_Sym *label; 1095 struct symbol *s; 1096 bool is_gpl; 1097 1098 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1099 label_name = sym_name(elf, label); 1100 1101 if (!strstarts(label_name, prefix)) { 1102 error("%s: .export_symbol section contains strange symbol '%s'\n", 1103 mod->name, label_name); 1104 return; 1105 } 1106 1107 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1108 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1109 error("%s: local symbol '%s' was exported\n", mod->name, 1110 label_name + strlen(prefix)); 1111 return; 1112 } 1113 1114 name = sym_name(elf, sym); 1115 if (strcmp(label_name + strlen(prefix), name)) { 1116 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1117 mod->name, name); 1118 return; 1119 } 1120 1121 data = sym_get_data(elf, label); /* license */ 1122 if (!strcmp(data, "GPL")) { 1123 is_gpl = true; 1124 } else if (!strcmp(data, "")) { 1125 is_gpl = false; 1126 } else { 1127 error("%s: unknown license '%s' was specified for '%s'\n", 1128 mod->name, data, name); 1129 return; 1130 } 1131 1132 data += strlen(data) + 1; /* namespace */ 1133 s = sym_add_exported(name, mod, is_gpl, data); 1134 1135 /* 1136 * We need to be aware whether we are exporting a function or 1137 * a data on some architectures. 1138 */ 1139 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1140 1141 /* 1142 * For parisc64, symbols prefixed $$ from the library have the symbol type 1143 * STT_LOPROC. They should be handled as functions too. 1144 */ 1145 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1146 elf->hdr->e_machine == EM_PARISC && 1147 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1148 s->is_func = true; 1149 1150 if (match(secname, PATTERNS(ALL_INIT_SECTIONS))) 1151 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1152 mod->name, name); 1153 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS))) 1154 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1155 mod->name, name); 1156 } 1157 1158 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1159 Elf_Sym *sym, 1160 unsigned int fsecndx, const char *fromsec, 1161 Elf_Addr faddr, Elf_Addr taddr) 1162 { 1163 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1164 const struct sectioncheck *mismatch; 1165 1166 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1167 check_export_symbol(mod, elf, faddr, tosec, sym); 1168 return; 1169 } 1170 1171 mismatch = section_mismatch(fromsec, tosec); 1172 if (!mismatch) 1173 return; 1174 1175 default_mismatch_handler(mod->name, elf, mismatch, sym, 1176 fsecndx, fromsec, faddr, 1177 tosec, taddr); 1178 } 1179 1180 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1181 { 1182 switch (r_type) { 1183 case R_386_32: 1184 return TO_NATIVE(*location); 1185 case R_386_PC32: 1186 return TO_NATIVE(*location) + 4; 1187 } 1188 1189 return (Elf_Addr)(-1); 1190 } 1191 1192 #ifndef R_ARM_CALL 1193 #define R_ARM_CALL 28 1194 #endif 1195 #ifndef R_ARM_JUMP24 1196 #define R_ARM_JUMP24 29 1197 #endif 1198 1199 #ifndef R_ARM_THM_CALL 1200 #define R_ARM_THM_CALL 10 1201 #endif 1202 #ifndef R_ARM_THM_JUMP24 1203 #define R_ARM_THM_JUMP24 30 1204 #endif 1205 1206 #ifndef R_ARM_MOVW_ABS_NC 1207 #define R_ARM_MOVW_ABS_NC 43 1208 #endif 1209 1210 #ifndef R_ARM_MOVT_ABS 1211 #define R_ARM_MOVT_ABS 44 1212 #endif 1213 1214 #ifndef R_ARM_THM_MOVW_ABS_NC 1215 #define R_ARM_THM_MOVW_ABS_NC 47 1216 #endif 1217 1218 #ifndef R_ARM_THM_MOVT_ABS 1219 #define R_ARM_THM_MOVT_ABS 48 1220 #endif 1221 1222 #ifndef R_ARM_THM_JUMP19 1223 #define R_ARM_THM_JUMP19 51 1224 #endif 1225 1226 static int32_t sign_extend32(int32_t value, int index) 1227 { 1228 uint8_t shift = 31 - index; 1229 1230 return (int32_t)(value << shift) >> shift; 1231 } 1232 1233 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1234 { 1235 uint32_t inst, upper, lower, sign, j1, j2; 1236 int32_t offset; 1237 1238 switch (r_type) { 1239 case R_ARM_ABS32: 1240 case R_ARM_REL32: 1241 inst = TO_NATIVE(*(uint32_t *)loc); 1242 return inst + sym->st_value; 1243 case R_ARM_MOVW_ABS_NC: 1244 case R_ARM_MOVT_ABS: 1245 inst = TO_NATIVE(*(uint32_t *)loc); 1246 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1247 15); 1248 return offset + sym->st_value; 1249 case R_ARM_PC24: 1250 case R_ARM_CALL: 1251 case R_ARM_JUMP24: 1252 inst = TO_NATIVE(*(uint32_t *)loc); 1253 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1254 return offset + sym->st_value + 8; 1255 case R_ARM_THM_MOVW_ABS_NC: 1256 case R_ARM_THM_MOVT_ABS: 1257 upper = TO_NATIVE(*(uint16_t *)loc); 1258 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1259 offset = sign_extend32(((upper & 0x000f) << 12) | 1260 ((upper & 0x0400) << 1) | 1261 ((lower & 0x7000) >> 4) | 1262 (lower & 0x00ff), 1263 15); 1264 return offset + sym->st_value; 1265 case R_ARM_THM_JUMP19: 1266 /* 1267 * Encoding T3: 1268 * S = upper[10] 1269 * imm6 = upper[5:0] 1270 * J1 = lower[13] 1271 * J2 = lower[11] 1272 * imm11 = lower[10:0] 1273 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1274 */ 1275 upper = TO_NATIVE(*(uint16_t *)loc); 1276 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1277 1278 sign = (upper >> 10) & 1; 1279 j1 = (lower >> 13) & 1; 1280 j2 = (lower >> 11) & 1; 1281 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1282 ((upper & 0x03f) << 12) | 1283 ((lower & 0x07ff) << 1), 1284 20); 1285 return offset + sym->st_value + 4; 1286 case R_ARM_THM_CALL: 1287 case R_ARM_THM_JUMP24: 1288 /* 1289 * Encoding T4: 1290 * S = upper[10] 1291 * imm10 = upper[9:0] 1292 * J1 = lower[13] 1293 * J2 = lower[11] 1294 * imm11 = lower[10:0] 1295 * I1 = NOT(J1 XOR S) 1296 * I2 = NOT(J2 XOR S) 1297 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1298 */ 1299 upper = TO_NATIVE(*(uint16_t *)loc); 1300 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1301 1302 sign = (upper >> 10) & 1; 1303 j1 = (lower >> 13) & 1; 1304 j2 = (lower >> 11) & 1; 1305 offset = sign_extend32((sign << 24) | 1306 ((~(j1 ^ sign) & 1) << 23) | 1307 ((~(j2 ^ sign) & 1) << 22) | 1308 ((upper & 0x03ff) << 12) | 1309 ((lower & 0x07ff) << 1), 1310 24); 1311 return offset + sym->st_value + 4; 1312 } 1313 1314 return (Elf_Addr)(-1); 1315 } 1316 1317 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1318 { 1319 uint32_t inst; 1320 1321 inst = TO_NATIVE(*location); 1322 switch (r_type) { 1323 case R_MIPS_LO16: 1324 return inst & 0xffff; 1325 case R_MIPS_26: 1326 return (inst & 0x03ffffff) << 2; 1327 case R_MIPS_32: 1328 return inst; 1329 } 1330 return (Elf_Addr)(-1); 1331 } 1332 1333 #ifndef EM_RISCV 1334 #define EM_RISCV 243 1335 #endif 1336 1337 #ifndef R_RISCV_SUB32 1338 #define R_RISCV_SUB32 39 1339 #endif 1340 1341 #ifndef EM_LOONGARCH 1342 #define EM_LOONGARCH 258 1343 #endif 1344 1345 #ifndef R_LARCH_SUB32 1346 #define R_LARCH_SUB32 55 1347 #endif 1348 1349 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1350 unsigned int *r_type, unsigned int *r_sym) 1351 { 1352 typedef struct { 1353 Elf64_Word r_sym; /* Symbol index */ 1354 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1355 unsigned char r_type3; /* 3rd relocation type */ 1356 unsigned char r_type2; /* 2nd relocation type */ 1357 unsigned char r_type; /* 1st relocation type */ 1358 } Elf64_Mips_R_Info; 1359 1360 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1361 1362 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1363 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1364 1365 *r_type = mips64_r_info->r_type; 1366 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1367 return; 1368 } 1369 1370 if (is_64bit) 1371 r_info = TO_NATIVE((Elf64_Xword)r_info); 1372 else 1373 r_info = TO_NATIVE((Elf32_Word)r_info); 1374 1375 *r_type = ELF_R_TYPE(r_info); 1376 *r_sym = ELF_R_SYM(r_info); 1377 } 1378 1379 static void section_rela(struct module *mod, struct elf_info *elf, 1380 unsigned int fsecndx, const char *fromsec, 1381 const Elf_Rela *start, const Elf_Rela *stop) 1382 { 1383 const Elf_Rela *rela; 1384 1385 for (rela = start; rela < stop; rela++) { 1386 Elf_Addr taddr, r_offset; 1387 unsigned int r_type, r_sym; 1388 1389 r_offset = TO_NATIVE(rela->r_offset); 1390 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1391 1392 taddr = 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 if (!strcmp("__ex_table", fromsec) && 1402 r_type == R_LARCH_SUB32) 1403 continue; 1404 break; 1405 } 1406 1407 check_section_mismatch(mod, elf, elf->symtab_start + r_sym, 1408 fsecndx, fromsec, r_offset, taddr); 1409 } 1410 } 1411 1412 static void section_rel(struct module *mod, struct elf_info *elf, 1413 unsigned int fsecndx, const char *fromsec, 1414 const Elf_Rel *start, const Elf_Rel *stop) 1415 { 1416 const Elf_Rel *rel; 1417 1418 for (rel = start; rel < stop; rel++) { 1419 Elf_Sym *tsym; 1420 Elf_Addr taddr = 0, r_offset; 1421 unsigned int r_type, r_sym; 1422 void *loc; 1423 1424 r_offset = TO_NATIVE(rel->r_offset); 1425 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1426 1427 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1428 tsym = elf->symtab_start + r_sym; 1429 1430 switch (elf->hdr->e_machine) { 1431 case EM_386: 1432 taddr = addend_386_rel(loc, r_type); 1433 break; 1434 case EM_ARM: 1435 taddr = addend_arm_rel(loc, tsym, r_type); 1436 break; 1437 case EM_MIPS: 1438 taddr = addend_mips_rel(loc, r_type); 1439 break; 1440 default: 1441 fatal("Please add code to calculate addend for this architecture\n"); 1442 } 1443 1444 check_section_mismatch(mod, elf, tsym, 1445 fsecndx, fromsec, r_offset, taddr); 1446 } 1447 } 1448 1449 /** 1450 * A module includes a number of sections that are discarded 1451 * either when loaded or when used as built-in. 1452 * For loaded modules all functions marked __init and all data 1453 * marked __initdata will be discarded when the module has been initialized. 1454 * Likewise for modules used built-in the sections marked __exit 1455 * are discarded because __exit marked function are supposed to be called 1456 * only when a module is unloaded which never happens for built-in modules. 1457 * The check_sec_ref() function traverses all relocation records 1458 * to find all references to a section that reference a section that will 1459 * be discarded and warns about it. 1460 **/ 1461 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1462 { 1463 int i; 1464 1465 /* Walk through all sections */ 1466 for (i = 0; i < elf->num_sections; i++) { 1467 Elf_Shdr *sechdr = &elf->sechdrs[i]; 1468 1469 check_section(mod->name, elf, sechdr); 1470 /* We want to process only relocation sections and not .init */ 1471 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) { 1472 /* section to which the relocation applies */ 1473 unsigned int secndx = sechdr->sh_info; 1474 const char *secname = sec_name(elf, secndx); 1475 const void *start, *stop; 1476 1477 /* If the section is known good, skip it */ 1478 if (match(secname, section_white_list)) 1479 continue; 1480 1481 start = sym_get_data_by_offset(elf, i, 0); 1482 stop = start + sechdr->sh_size; 1483 1484 if (sechdr->sh_type == SHT_RELA) 1485 section_rela(mod, elf, secndx, secname, 1486 start, stop); 1487 else 1488 section_rel(mod, elf, secndx, secname, 1489 start, stop); 1490 } 1491 } 1492 } 1493 1494 static char *remove_dot(char *s) 1495 { 1496 size_t n = strcspn(s, "."); 1497 1498 if (n && s[n]) { 1499 size_t m = strspn(s + n + 1, "0123456789"); 1500 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1501 s[n] = 0; 1502 } 1503 return s; 1504 } 1505 1506 /* 1507 * The CRCs are recorded in .*.cmd files in the form of: 1508 * #SYMVER <name> <crc> 1509 */ 1510 static void extract_crcs_for_object(const char *object, struct module *mod) 1511 { 1512 char cmd_file[PATH_MAX]; 1513 char *buf, *p; 1514 const char *base; 1515 int dirlen, ret; 1516 1517 base = strrchr(object, '/'); 1518 if (base) { 1519 base++; 1520 dirlen = base - object; 1521 } else { 1522 dirlen = 0; 1523 base = object; 1524 } 1525 1526 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1527 dirlen, object, base); 1528 if (ret >= sizeof(cmd_file)) { 1529 error("%s: too long path was truncated\n", cmd_file); 1530 return; 1531 } 1532 1533 buf = read_text_file(cmd_file); 1534 p = buf; 1535 1536 while ((p = strstr(p, "\n#SYMVER "))) { 1537 char *name; 1538 size_t namelen; 1539 unsigned int crc; 1540 struct symbol *sym; 1541 1542 name = p + strlen("\n#SYMVER "); 1543 1544 p = strchr(name, ' '); 1545 if (!p) 1546 break; 1547 1548 namelen = p - name; 1549 p++; 1550 1551 if (!isdigit(*p)) 1552 continue; /* skip this line */ 1553 1554 crc = strtoul(p, &p, 0); 1555 if (*p != '\n') 1556 continue; /* skip this line */ 1557 1558 name[namelen] = '\0'; 1559 1560 /* 1561 * sym_find_with_module() may return NULL here. 1562 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1563 * Since commit e1327a127703, genksyms calculates CRCs of all 1564 * symbols, including trimmed ones. Ignore orphan CRCs. 1565 */ 1566 sym = sym_find_with_module(name, mod); 1567 if (sym) 1568 sym_set_crc(sym, crc); 1569 } 1570 1571 free(buf); 1572 } 1573 1574 /* 1575 * The symbol versions (CRC) are recorded in the .*.cmd files. 1576 * Parse them to retrieve CRCs for the current module. 1577 */ 1578 static void mod_set_crcs(struct module *mod) 1579 { 1580 char objlist[PATH_MAX]; 1581 char *buf, *p, *obj; 1582 int ret; 1583 1584 if (mod->is_vmlinux) { 1585 strcpy(objlist, ".vmlinux.objs"); 1586 } else { 1587 /* objects for a module are listed in the *.mod file. */ 1588 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1589 if (ret >= sizeof(objlist)) { 1590 error("%s: too long path was truncated\n", objlist); 1591 return; 1592 } 1593 } 1594 1595 buf = read_text_file(objlist); 1596 p = buf; 1597 1598 while ((obj = strsep(&p, "\n")) && obj[0]) 1599 extract_crcs_for_object(obj, mod); 1600 1601 free(buf); 1602 } 1603 1604 static void read_symbols(const char *modname) 1605 { 1606 const char *symname; 1607 char *version; 1608 char *license; 1609 char *namespace; 1610 struct module *mod; 1611 struct elf_info info = { }; 1612 Elf_Sym *sym; 1613 1614 if (!parse_elf(&info, modname)) 1615 return; 1616 1617 if (!strends(modname, ".o")) { 1618 error("%s: filename must be suffixed with .o\n", modname); 1619 return; 1620 } 1621 1622 /* strip trailing .o */ 1623 mod = new_module(modname, strlen(modname) - strlen(".o")); 1624 1625 if (!mod->is_vmlinux) { 1626 license = get_modinfo(&info, "license"); 1627 if (!license) 1628 error("missing MODULE_LICENSE() in %s\n", modname); 1629 while (license) { 1630 if (!license_is_gpl_compatible(license)) { 1631 mod->is_gpl_compatible = false; 1632 break; 1633 } 1634 license = get_next_modinfo(&info, "license", license); 1635 } 1636 1637 namespace = get_modinfo(&info, "import_ns"); 1638 while (namespace) { 1639 add_namespace(&mod->imported_namespaces, namespace); 1640 namespace = get_next_modinfo(&info, "import_ns", 1641 namespace); 1642 } 1643 } 1644 1645 if (extra_warn && !get_modinfo(&info, "description")) 1646 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1647 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1648 symname = remove_dot(info.strtab + sym->st_name); 1649 1650 handle_symbol(mod, &info, sym, symname); 1651 handle_moddevtable(mod, &info, sym, symname); 1652 } 1653 1654 check_sec_ref(mod, &info); 1655 1656 if (!mod->is_vmlinux) { 1657 version = get_modinfo(&info, "version"); 1658 if (version || all_versions) 1659 get_src_version(mod->name, mod->srcversion, 1660 sizeof(mod->srcversion) - 1); 1661 } 1662 1663 parse_elf_finish(&info); 1664 1665 if (modversions) { 1666 /* 1667 * Our trick to get versioning for module struct etc. - it's 1668 * never passed as an argument to an exported function, so 1669 * the automatic versioning doesn't pick it up, but it's really 1670 * important anyhow. 1671 */ 1672 sym_add_unresolved("module_layout", mod, false); 1673 1674 mod_set_crcs(mod); 1675 } 1676 } 1677 1678 static void read_symbols_from_files(const char *filename) 1679 { 1680 FILE *in = stdin; 1681 char fname[PATH_MAX]; 1682 1683 in = fopen(filename, "r"); 1684 if (!in) 1685 fatal("Can't open filenames file %s: %m", filename); 1686 1687 while (fgets(fname, PATH_MAX, in) != NULL) { 1688 if (strends(fname, "\n")) 1689 fname[strlen(fname)-1] = '\0'; 1690 read_symbols(fname); 1691 } 1692 1693 fclose(in); 1694 } 1695 1696 #define SZ 500 1697 1698 /* We first write the generated file into memory using the 1699 * following helper, then compare to the file on disk and 1700 * only update the later if anything changed */ 1701 1702 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1703 const char *fmt, ...) 1704 { 1705 char tmp[SZ]; 1706 int len; 1707 va_list ap; 1708 1709 va_start(ap, fmt); 1710 len = vsnprintf(tmp, SZ, fmt, ap); 1711 buf_write(buf, tmp, len); 1712 va_end(ap); 1713 } 1714 1715 void buf_write(struct buffer *buf, const char *s, int len) 1716 { 1717 if (buf->size - buf->pos < len) { 1718 buf->size += len + SZ; 1719 buf->p = NOFAIL(realloc(buf->p, buf->size)); 1720 } 1721 strncpy(buf->p + buf->pos, s, len); 1722 buf->pos += len; 1723 } 1724 1725 static void check_exports(struct module *mod) 1726 { 1727 struct symbol *s, *exp; 1728 1729 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1730 const char *basename; 1731 exp = find_symbol(s->name); 1732 if (!exp) { 1733 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1734 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, 1735 "\"%s\" [%s.ko] undefined!\n", 1736 s->name, mod->name); 1737 continue; 1738 } 1739 if (exp->module == mod) { 1740 error("\"%s\" [%s.ko] was exported without definition\n", 1741 s->name, mod->name); 1742 continue; 1743 } 1744 1745 exp->used = true; 1746 s->module = exp->module; 1747 s->crc_valid = exp->crc_valid; 1748 s->crc = exp->crc; 1749 1750 basename = strrchr(mod->name, '/'); 1751 if (basename) 1752 basename++; 1753 else 1754 basename = mod->name; 1755 1756 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1757 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, 1758 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1759 basename, exp->name, exp->namespace); 1760 add_namespace(&mod->missing_namespaces, exp->namespace); 1761 } 1762 1763 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1764 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1765 basename, exp->name); 1766 } 1767 } 1768 1769 static void handle_white_list_exports(const char *white_list) 1770 { 1771 char *buf, *p, *name; 1772 1773 buf = read_text_file(white_list); 1774 p = buf; 1775 1776 while ((name = strsep(&p, "\n"))) { 1777 struct symbol *sym = find_symbol(name); 1778 1779 if (sym) 1780 sym->used = true; 1781 } 1782 1783 free(buf); 1784 } 1785 1786 static void check_modname_len(struct module *mod) 1787 { 1788 const char *mod_name; 1789 1790 mod_name = strrchr(mod->name, '/'); 1791 if (mod_name == NULL) 1792 mod_name = mod->name; 1793 else 1794 mod_name++; 1795 if (strlen(mod_name) >= MODULE_NAME_LEN) 1796 error("module name is too long [%s.ko]\n", mod->name); 1797 } 1798 1799 /** 1800 * Header for the generated file 1801 **/ 1802 static void add_header(struct buffer *b, struct module *mod) 1803 { 1804 buf_printf(b, "#include <linux/module.h>\n"); 1805 /* 1806 * Include build-salt.h after module.h in order to 1807 * inherit the definitions. 1808 */ 1809 buf_printf(b, "#define INCLUDE_VERMAGIC\n"); 1810 buf_printf(b, "#include <linux/build-salt.h>\n"); 1811 buf_printf(b, "#include <linux/elfnote-lto.h>\n"); 1812 buf_printf(b, "#include <linux/export-internal.h>\n"); 1813 buf_printf(b, "#include <linux/vermagic.h>\n"); 1814 buf_printf(b, "#include <linux/compiler.h>\n"); 1815 buf_printf(b, "\n"); 1816 buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n"); 1817 buf_printf(b, "#include <asm/orc_header.h>\n"); 1818 buf_printf(b, "ORC_HEADER;\n"); 1819 buf_printf(b, "#endif\n"); 1820 buf_printf(b, "\n"); 1821 buf_printf(b, "BUILD_SALT;\n"); 1822 buf_printf(b, "BUILD_LTO_INFO;\n"); 1823 buf_printf(b, "\n"); 1824 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1825 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1826 buf_printf(b, "\n"); 1827 buf_printf(b, "__visible struct module __this_module\n"); 1828 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1829 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1830 if (mod->has_init) 1831 buf_printf(b, "\t.init = init_module,\n"); 1832 if (mod->has_cleanup) 1833 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1834 "\t.exit = cleanup_module,\n" 1835 "#endif\n"); 1836 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1837 buf_printf(b, "};\n"); 1838 1839 if (!external_module) 1840 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1841 1842 buf_printf(b, 1843 "\n" 1844 "#ifdef CONFIG_RETPOLINE\n" 1845 "MODULE_INFO(retpoline, \"Y\");\n" 1846 "#endif\n"); 1847 1848 if (strstarts(mod->name, "drivers/staging")) 1849 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1850 1851 if (strstarts(mod->name, "tools/testing")) 1852 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1853 } 1854 1855 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1856 { 1857 struct symbol *sym; 1858 1859 /* generate struct for exported symbols */ 1860 buf_printf(buf, "\n"); 1861 list_for_each_entry(sym, &mod->exported_symbols, list) { 1862 if (trim_unused_exports && !sym->used) 1863 continue; 1864 1865 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1866 sym->is_func ? "FUNC" : "DATA", sym->name, 1867 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1868 } 1869 1870 if (!modversions) 1871 return; 1872 1873 /* record CRCs for exported symbols */ 1874 buf_printf(buf, "\n"); 1875 list_for_each_entry(sym, &mod->exported_symbols, list) { 1876 if (trim_unused_exports && !sym->used) 1877 continue; 1878 1879 if (!sym->crc_valid) 1880 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1881 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1882 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1883 sym->name); 1884 1885 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1886 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1887 } 1888 } 1889 1890 /** 1891 * Record CRCs for unresolved symbols 1892 **/ 1893 static void add_versions(struct buffer *b, struct module *mod) 1894 { 1895 struct symbol *s; 1896 1897 if (!modversions) 1898 return; 1899 1900 buf_printf(b, "\n"); 1901 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1902 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1903 1904 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1905 if (!s->module) 1906 continue; 1907 if (!s->crc_valid) { 1908 warn("\"%s\" [%s.ko] has no CRC!\n", 1909 s->name, mod->name); 1910 continue; 1911 } 1912 if (strlen(s->name) >= MODULE_NAME_LEN) { 1913 error("too long symbol \"%s\" [%s.ko]\n", 1914 s->name, mod->name); 1915 break; 1916 } 1917 buf_printf(b, "\t{ %#8x, \"%s\" },\n", 1918 s->crc, s->name); 1919 } 1920 1921 buf_printf(b, "};\n"); 1922 } 1923 1924 static void add_depends(struct buffer *b, struct module *mod) 1925 { 1926 struct symbol *s; 1927 int first = 1; 1928 1929 /* Clear ->seen flag of modules that own symbols needed by this. */ 1930 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1931 if (s->module) 1932 s->module->seen = s->module->is_vmlinux; 1933 } 1934 1935 buf_printf(b, "\n"); 1936 buf_printf(b, "MODULE_INFO(depends, \""); 1937 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1938 const char *p; 1939 if (!s->module) 1940 continue; 1941 1942 if (s->module->seen) 1943 continue; 1944 1945 s->module->seen = true; 1946 p = strrchr(s->module->name, '/'); 1947 if (p) 1948 p++; 1949 else 1950 p = s->module->name; 1951 buf_printf(b, "%s%s", first ? "" : ",", p); 1952 first = 0; 1953 } 1954 buf_printf(b, "\");\n"); 1955 } 1956 1957 static void add_srcversion(struct buffer *b, struct module *mod) 1958 { 1959 if (mod->srcversion[0]) { 1960 buf_printf(b, "\n"); 1961 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1962 mod->srcversion); 1963 } 1964 } 1965 1966 static void write_buf(struct buffer *b, const char *fname) 1967 { 1968 FILE *file; 1969 1970 if (error_occurred) 1971 return; 1972 1973 file = fopen(fname, "w"); 1974 if (!file) { 1975 perror(fname); 1976 exit(1); 1977 } 1978 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1979 perror(fname); 1980 exit(1); 1981 } 1982 if (fclose(file) != 0) { 1983 perror(fname); 1984 exit(1); 1985 } 1986 } 1987 1988 static void write_if_changed(struct buffer *b, const char *fname) 1989 { 1990 char *tmp; 1991 FILE *file; 1992 struct stat st; 1993 1994 file = fopen(fname, "r"); 1995 if (!file) 1996 goto write; 1997 1998 if (fstat(fileno(file), &st) < 0) 1999 goto close_write; 2000 2001 if (st.st_size != b->pos) 2002 goto close_write; 2003 2004 tmp = NOFAIL(malloc(b->pos)); 2005 if (fread(tmp, 1, b->pos, file) != b->pos) 2006 goto free_write; 2007 2008 if (memcmp(tmp, b->p, b->pos) != 0) 2009 goto free_write; 2010 2011 free(tmp); 2012 fclose(file); 2013 return; 2014 2015 free_write: 2016 free(tmp); 2017 close_write: 2018 fclose(file); 2019 write: 2020 write_buf(b, fname); 2021 } 2022 2023 static void write_vmlinux_export_c_file(struct module *mod) 2024 { 2025 struct buffer buf = { }; 2026 2027 buf_printf(&buf, 2028 "#include <linux/export-internal.h>\n"); 2029 2030 add_exported_symbols(&buf, mod); 2031 write_if_changed(&buf, ".vmlinux.export.c"); 2032 free(buf.p); 2033 } 2034 2035 /* do sanity checks, and generate *.mod.c file */ 2036 static void write_mod_c_file(struct module *mod) 2037 { 2038 struct buffer buf = { }; 2039 char fname[PATH_MAX]; 2040 int ret; 2041 2042 add_header(&buf, mod); 2043 add_exported_symbols(&buf, mod); 2044 add_versions(&buf, mod); 2045 add_depends(&buf, mod); 2046 add_moddevtable(&buf, mod); 2047 add_srcversion(&buf, mod); 2048 2049 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2050 if (ret >= sizeof(fname)) { 2051 error("%s: too long path was truncated\n", fname); 2052 goto free; 2053 } 2054 2055 write_if_changed(&buf, fname); 2056 2057 free: 2058 free(buf.p); 2059 } 2060 2061 /* parse Module.symvers file. line format: 2062 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2063 **/ 2064 static void read_dump(const char *fname) 2065 { 2066 char *buf, *pos, *line; 2067 2068 buf = read_text_file(fname); 2069 if (!buf) 2070 /* No symbol versions, silently ignore */ 2071 return; 2072 2073 pos = buf; 2074 2075 while ((line = get_line(&pos))) { 2076 char *symname, *namespace, *modname, *d, *export; 2077 unsigned int crc; 2078 struct module *mod; 2079 struct symbol *s; 2080 bool gpl_only; 2081 2082 if (!(symname = strchr(line, '\t'))) 2083 goto fail; 2084 *symname++ = '\0'; 2085 if (!(modname = strchr(symname, '\t'))) 2086 goto fail; 2087 *modname++ = '\0'; 2088 if (!(export = strchr(modname, '\t'))) 2089 goto fail; 2090 *export++ = '\0'; 2091 if (!(namespace = strchr(export, '\t'))) 2092 goto fail; 2093 *namespace++ = '\0'; 2094 2095 crc = strtoul(line, &d, 16); 2096 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2097 goto fail; 2098 2099 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2100 gpl_only = true; 2101 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2102 gpl_only = false; 2103 } else { 2104 error("%s: unknown license %s. skip", symname, export); 2105 continue; 2106 } 2107 2108 mod = find_module(modname); 2109 if (!mod) { 2110 mod = new_module(modname, strlen(modname)); 2111 mod->from_dump = true; 2112 } 2113 s = sym_add_exported(symname, mod, gpl_only, namespace); 2114 sym_set_crc(s, crc); 2115 } 2116 free(buf); 2117 return; 2118 fail: 2119 free(buf); 2120 fatal("parse error in symbol dump file\n"); 2121 } 2122 2123 static void write_dump(const char *fname) 2124 { 2125 struct buffer buf = { }; 2126 struct module *mod; 2127 struct symbol *sym; 2128 2129 list_for_each_entry(mod, &modules, list) { 2130 if (mod->from_dump) 2131 continue; 2132 list_for_each_entry(sym, &mod->exported_symbols, list) { 2133 if (trim_unused_exports && !sym->used) 2134 continue; 2135 2136 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2137 sym->crc, sym->name, mod->name, 2138 sym->is_gpl_only ? "_GPL" : "", 2139 sym->namespace); 2140 } 2141 } 2142 write_buf(&buf, fname); 2143 free(buf.p); 2144 } 2145 2146 static void write_namespace_deps_files(const char *fname) 2147 { 2148 struct module *mod; 2149 struct namespace_list *ns; 2150 struct buffer ns_deps_buf = {}; 2151 2152 list_for_each_entry(mod, &modules, list) { 2153 2154 if (mod->from_dump || list_empty(&mod->missing_namespaces)) 2155 continue; 2156 2157 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2158 2159 list_for_each_entry(ns, &mod->missing_namespaces, list) 2160 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2161 2162 buf_printf(&ns_deps_buf, "\n"); 2163 } 2164 2165 write_if_changed(&ns_deps_buf, fname); 2166 free(ns_deps_buf.p); 2167 } 2168 2169 struct dump_list { 2170 struct list_head list; 2171 const char *file; 2172 }; 2173 2174 int main(int argc, char **argv) 2175 { 2176 struct module *mod; 2177 char *missing_namespace_deps = NULL; 2178 char *unused_exports_white_list = NULL; 2179 char *dump_write = NULL, *files_source = NULL; 2180 int opt; 2181 LIST_HEAD(dump_lists); 2182 struct dump_list *dl, *dl2; 2183 2184 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) { 2185 switch (opt) { 2186 case 'e': 2187 external_module = true; 2188 break; 2189 case 'i': 2190 dl = NOFAIL(malloc(sizeof(*dl))); 2191 dl->file = optarg; 2192 list_add_tail(&dl->list, &dump_lists); 2193 break; 2194 case 'M': 2195 module_enabled = true; 2196 break; 2197 case 'm': 2198 modversions = true; 2199 break; 2200 case 'n': 2201 ignore_missing_files = true; 2202 break; 2203 case 'o': 2204 dump_write = optarg; 2205 break; 2206 case 'a': 2207 all_versions = true; 2208 break; 2209 case 'T': 2210 files_source = optarg; 2211 break; 2212 case 't': 2213 trim_unused_exports = true; 2214 break; 2215 case 'u': 2216 unused_exports_white_list = optarg; 2217 break; 2218 case 'W': 2219 extra_warn = true; 2220 break; 2221 case 'w': 2222 warn_unresolved = true; 2223 break; 2224 case 'E': 2225 sec_mismatch_warn_only = false; 2226 break; 2227 case 'N': 2228 allow_missing_ns_imports = true; 2229 break; 2230 case 'd': 2231 missing_namespace_deps = optarg; 2232 break; 2233 default: 2234 exit(1); 2235 } 2236 } 2237 2238 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2239 read_dump(dl->file); 2240 list_del(&dl->list); 2241 free(dl); 2242 } 2243 2244 while (optind < argc) 2245 read_symbols(argv[optind++]); 2246 2247 if (files_source) 2248 read_symbols_from_files(files_source); 2249 2250 list_for_each_entry(mod, &modules, list) { 2251 if (mod->from_dump || mod->is_vmlinux) 2252 continue; 2253 2254 check_modname_len(mod); 2255 check_exports(mod); 2256 } 2257 2258 if (unused_exports_white_list) 2259 handle_white_list_exports(unused_exports_white_list); 2260 2261 list_for_each_entry(mod, &modules, list) { 2262 if (mod->from_dump) 2263 continue; 2264 2265 if (mod->is_vmlinux) 2266 write_vmlinux_export_c_file(mod); 2267 else 2268 write_mod_c_file(mod); 2269 } 2270 2271 if (missing_namespace_deps) 2272 write_namespace_deps_files(missing_namespace_deps); 2273 2274 if (dump_write) 2275 write_dump(dump_write); 2276 if (sec_mismatch_count && !sec_mismatch_warn_only) 2277 error("Section mismatches detected.\n" 2278 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2279 2280 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2281 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2282 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2283 2284 return error_occurred ? 1 : 0; 2285 } 2286