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; 604 605 if (info->hdr->e_machine == EM_S390) 606 /* Expoline thunks are linked on all kernel modules during final link of .ko */ 607 if (strstarts(symname, "__s390_indirect_jump_r")) 608 return 1; 609 /* Do not ignore this symbol */ 610 return 0; 611 } 612 613 static void handle_symbol(struct module *mod, struct elf_info *info, 614 const Elf_Sym *sym, const char *symname) 615 { 616 switch (sym->st_shndx) { 617 case SHN_COMMON: 618 if (strstarts(symname, "__gnu_lto_")) { 619 /* Should warn here, but modpost runs before the linker */ 620 } else 621 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 622 break; 623 case SHN_UNDEF: 624 /* undefined symbol */ 625 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 626 ELF_ST_BIND(sym->st_info) != STB_WEAK) 627 break; 628 if (ignore_undef_symbol(info, symname)) 629 break; 630 if (info->hdr->e_machine == EM_SPARC || 631 info->hdr->e_machine == EM_SPARCV9) { 632 /* Ignore register directives. */ 633 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 634 break; 635 if (symname[0] == '.') { 636 char *munged = NOFAIL(strdup(symname)); 637 munged[0] = '_'; 638 munged[1] = toupper(munged[1]); 639 symname = munged; 640 } 641 } 642 643 sym_add_unresolved(symname, mod, 644 ELF_ST_BIND(sym->st_info) == STB_WEAK); 645 break; 646 default: 647 if (strcmp(symname, "init_module") == 0) 648 mod->has_init = true; 649 if (strcmp(symname, "cleanup_module") == 0) 650 mod->has_cleanup = true; 651 break; 652 } 653 } 654 655 /** 656 * Parse tag=value strings from .modinfo section 657 **/ 658 static char *next_string(char *string, unsigned long *secsize) 659 { 660 /* Skip non-zero chars */ 661 while (string[0]) { 662 string++; 663 if ((*secsize)-- <= 1) 664 return NULL; 665 } 666 667 /* Skip any zero padding. */ 668 while (!string[0]) { 669 string++; 670 if ((*secsize)-- <= 1) 671 return NULL; 672 } 673 return string; 674 } 675 676 static char *get_next_modinfo(struct elf_info *info, const char *tag, 677 char *prev) 678 { 679 char *p; 680 unsigned int taglen = strlen(tag); 681 char *modinfo = info->modinfo; 682 unsigned long size = info->modinfo_len; 683 684 if (prev) { 685 size -= prev - modinfo; 686 modinfo = next_string(prev, &size); 687 } 688 689 for (p = modinfo; p; p = next_string(p, &size)) { 690 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 691 return p + taglen + 1; 692 } 693 return NULL; 694 } 695 696 static char *get_modinfo(struct elf_info *info, const char *tag) 697 698 { 699 return get_next_modinfo(info, tag, NULL); 700 } 701 702 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 703 { 704 if (sym) 705 return elf->strtab + sym->st_name; 706 else 707 return "(unknown)"; 708 } 709 710 /* 711 * Check whether the 'string' argument matches one of the 'patterns', 712 * an array of shell wildcard patterns (glob). 713 * 714 * Return true is there is a match. 715 */ 716 static bool match(const char *string, const char *const patterns[]) 717 { 718 const char *pattern; 719 720 while ((pattern = *patterns++)) { 721 if (!fnmatch(pattern, string, 0)) 722 return true; 723 } 724 725 return false; 726 } 727 728 /* useful to pass patterns to match() directly */ 729 #define PATTERNS(...) \ 730 ({ \ 731 static const char *const patterns[] = {__VA_ARGS__, NULL}; \ 732 patterns; \ 733 }) 734 735 /* sections that we do not want to do full section mismatch check on */ 736 static const char *const section_white_list[] = 737 { 738 ".comment*", 739 ".debug*", 740 ".zdebug*", /* Compressed debug sections. */ 741 ".GCC.command.line", /* record-gcc-switches */ 742 ".mdebug*", /* alpha, score, mips etc. */ 743 ".pdr", /* alpha, score, mips etc. */ 744 ".stab*", 745 ".note*", 746 ".got*", 747 ".toc*", 748 ".xt.prop", /* xtensa */ 749 ".xt.lit", /* xtensa */ 750 ".arcextmap*", /* arc */ 751 ".gnu.linkonce.arcext*", /* arc : modules */ 752 ".cmem*", /* EZchip */ 753 ".fmt_slot*", /* EZchip */ 754 ".gnu.lto*", 755 ".discard.*", 756 ".llvm.call-graph-profile", /* call graph */ 757 NULL 758 }; 759 760 /* 761 * This is used to find sections missing the SHF_ALLOC flag. 762 * The cause of this is often a section specified in assembler 763 * without "ax" / "aw". 764 */ 765 static void check_section(const char *modname, struct elf_info *elf, 766 Elf_Shdr *sechdr) 767 { 768 const char *sec = sech_name(elf, sechdr); 769 770 if (sechdr->sh_type == SHT_PROGBITS && 771 !(sechdr->sh_flags & SHF_ALLOC) && 772 !match(sec, section_white_list)) { 773 warn("%s (%s): unexpected non-allocatable section.\n" 774 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 775 "Note that for example <linux/init.h> contains\n" 776 "section definitions for use in .S files.\n\n", 777 modname, sec); 778 } 779 } 780 781 782 783 #define ALL_INIT_DATA_SECTIONS \ 784 ".init.setup", ".init.rodata", ".meminit.rodata", \ 785 ".init.data", ".meminit.data" 786 787 #define ALL_PCI_INIT_SECTIONS \ 788 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 789 ".pci_fixup_enable", ".pci_fixup_resume", \ 790 ".pci_fixup_resume_early", ".pci_fixup_suspend" 791 792 #define ALL_XXXINIT_SECTIONS ".meminit.*" 793 794 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 795 #define ALL_EXIT_SECTIONS ".exit.*" 796 797 #define DATA_SECTIONS ".data", ".data.rel" 798 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ 799 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \ 800 ".ltext", ".ltext.*" 801 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ 802 ".fixup", ".entry.text", ".exception.text", \ 803 ".coldtext", ".softirqentry.text" 804 805 #define INIT_SECTIONS ".init.*" 806 807 #define ALL_TEXT_SECTIONS ".init.text", ".meminit.text", ".exit.text", \ 808 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 809 810 enum mismatch { 811 TEXTDATA_TO_ANY_INIT_EXIT, 812 XXXINIT_TO_SOME_INIT, 813 ANY_INIT_TO_ANY_EXIT, 814 ANY_EXIT_TO_ANY_INIT, 815 EXTABLE_TO_NON_TEXT, 816 }; 817 818 /** 819 * Describe how to match sections on different criteria: 820 * 821 * @fromsec: Array of sections to be matched. 822 * 823 * @bad_tosec: Relocations applied to a section in @fromsec to a section in 824 * this array is forbidden (black-list). Can be empty. 825 * 826 * @good_tosec: Relocations applied to a section in @fromsec must be 827 * targeting sections in this array (white-list). Can be empty. 828 * 829 * @mismatch: Type of mismatch. 830 */ 831 struct sectioncheck { 832 const char *fromsec[20]; 833 const char *bad_tosec[20]; 834 const char *good_tosec[20]; 835 enum mismatch mismatch; 836 }; 837 838 static const struct sectioncheck sectioncheck[] = { 839 /* Do not reference init/exit code/data from 840 * normal code and data 841 */ 842 { 843 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 844 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }, 845 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT, 846 }, 847 /* Do not reference init code/data from meminit code/data */ 848 { 849 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 850 .bad_tosec = { INIT_SECTIONS, NULL }, 851 .mismatch = XXXINIT_TO_SOME_INIT, 852 }, 853 /* Do not use exit code/data from init code */ 854 { 855 .fromsec = { ALL_INIT_SECTIONS, NULL }, 856 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 857 .mismatch = ANY_INIT_TO_ANY_EXIT, 858 }, 859 /* Do not use init code/data from exit code */ 860 { 861 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 862 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 863 .mismatch = ANY_EXIT_TO_ANY_INIT, 864 }, 865 { 866 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 867 .bad_tosec = { INIT_SECTIONS, NULL }, 868 .mismatch = ANY_INIT_TO_ANY_EXIT, 869 }, 870 { 871 .fromsec = { "__ex_table", NULL }, 872 /* If you're adding any new black-listed sections in here, consider 873 * adding a special 'printer' for them in scripts/check_extable. 874 */ 875 .bad_tosec = { ".altinstr_replacement", NULL }, 876 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 877 .mismatch = EXTABLE_TO_NON_TEXT, 878 } 879 }; 880 881 static const struct sectioncheck *section_mismatch( 882 const char *fromsec, const char *tosec) 883 { 884 int i; 885 886 /* 887 * The target section could be the SHT_NUL section when we're 888 * handling relocations to un-resolved symbols, trying to match it 889 * doesn't make much sense and causes build failures on parisc 890 * architectures. 891 */ 892 if (*tosec == '\0') 893 return NULL; 894 895 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 896 const struct sectioncheck *check = §ioncheck[i]; 897 898 if (match(fromsec, check->fromsec)) { 899 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 900 return check; 901 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 902 return check; 903 } 904 } 905 return NULL; 906 } 907 908 /** 909 * Whitelist to allow certain references to pass with no warning. 910 * 911 * Pattern 1: 912 * If a module parameter is declared __initdata and permissions=0 913 * then this is legal despite the warning generated. 914 * We cannot see value of permissions here, so just ignore 915 * this pattern. 916 * The pattern is identified by: 917 * tosec = .init.data 918 * fromsec = .data* 919 * atsym =__param* 920 * 921 * Pattern 1a: 922 * module_param_call() ops can refer to __init set function if permissions=0 923 * The pattern is identified by: 924 * tosec = .init.text 925 * fromsec = .data* 926 * atsym = __param_ops_* 927 * 928 * Pattern 3: 929 * Whitelist all references from .head.text to any init section 930 * 931 * Pattern 4: 932 * Some symbols belong to init section but still it is ok to reference 933 * these from non-init sections as these symbols don't have any memory 934 * allocated for them and symbol address and value are same. So even 935 * if init section is freed, its ok to reference those symbols. 936 * For ex. symbols marking the init section boundaries. 937 * This pattern is identified by 938 * refsymname = __init_begin, _sinittext, _einittext 939 * 940 * Pattern 5: 941 * GCC may optimize static inlines when fed constant arg(s) resulting 942 * in functions like cpumask_empty() -- generating an associated symbol 943 * cpumask_empty.constprop.3 that appears in the audit. If the const that 944 * is passed in comes from __init, like say nmi_ipi_mask, we get a 945 * meaningless section warning. May need to add isra symbols too... 946 * This pattern is identified by 947 * tosec = init section 948 * fromsec = text section 949 * refsymname = *.constprop.* 950 * 951 **/ 952 static int secref_whitelist(const char *fromsec, const char *fromsym, 953 const char *tosec, const char *tosym) 954 { 955 /* Check for pattern 1 */ 956 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 957 match(fromsec, PATTERNS(DATA_SECTIONS)) && 958 strstarts(fromsym, "__param")) 959 return 0; 960 961 /* Check for pattern 1a */ 962 if (strcmp(tosec, ".init.text") == 0 && 963 match(fromsec, PATTERNS(DATA_SECTIONS)) && 964 strstarts(fromsym, "__param_ops_")) 965 return 0; 966 967 /* symbols in data sections that may refer to any init/exit sections */ 968 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 969 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 970 match(fromsym, PATTERNS("*_ops", "*_probe", "*_console"))) 971 return 0; 972 973 /* 974 * symbols in data sections must not refer to .exit.*, but there are 975 * quite a few offenders, so hide these unless for W=1 builds until 976 * these are fixed. 977 */ 978 if (!extra_warn && 979 match(fromsec, PATTERNS(DATA_SECTIONS)) && 980 match(tosec, PATTERNS(ALL_EXIT_SECTIONS)) && 981 match(fromsym, PATTERNS("*driver"))) 982 return 0; 983 984 /* Check for pattern 3 */ 985 if (strstarts(fromsec, ".head.text") && 986 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 987 return 0; 988 989 /* Check for pattern 4 */ 990 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 991 return 0; 992 993 /* Check for pattern 5 */ 994 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 995 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 996 match(fromsym, PATTERNS("*.constprop.*"))) 997 return 0; 998 999 return 1; 1000 } 1001 1002 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 1003 unsigned int secndx) 1004 { 1005 return symsearch_find_nearest(elf, addr, secndx, false, ~0); 1006 } 1007 1008 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 1009 { 1010 Elf_Sym *new_sym; 1011 1012 /* If the supplied symbol has a valid name, return it */ 1013 if (is_valid_name(elf, sym)) 1014 return sym; 1015 1016 /* 1017 * Strive to find a better symbol name, but the resulting name may not 1018 * match the symbol referenced in the original code. 1019 */ 1020 new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym), 1021 true, 20); 1022 return new_sym ? new_sym : sym; 1023 } 1024 1025 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1026 { 1027 if (secndx >= elf->num_sections) 1028 return false; 1029 1030 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1031 } 1032 1033 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1034 const struct sectioncheck* const mismatch, 1035 Elf_Sym *tsym, 1036 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1037 const char *tosec, Elf_Addr taddr) 1038 { 1039 Elf_Sym *from; 1040 const char *tosym; 1041 const char *fromsym; 1042 1043 from = find_fromsym(elf, faddr, fsecndx); 1044 fromsym = sym_name(elf, from); 1045 1046 tsym = find_tosym(elf, taddr, tsym); 1047 tosym = sym_name(elf, tsym); 1048 1049 /* check whitelist - we may ignore it */ 1050 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1051 return; 1052 1053 sec_mismatch_count++; 1054 1055 warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n", 1056 modname, fromsym, 1057 (unsigned int)(faddr - (from ? from->st_value : 0)), 1058 fromsec, tosym, tosec); 1059 1060 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1061 if (match(tosec, mismatch->bad_tosec)) 1062 fatal("The relocation at %s+0x%lx references\n" 1063 "section \"%s\" which is black-listed.\n" 1064 "Something is seriously wrong and should be fixed.\n" 1065 "You might get more information about where this is\n" 1066 "coming from by using scripts/check_extable.sh %s\n", 1067 fromsec, (long)faddr, tosec, modname); 1068 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1069 warn("The relocation at %s+0x%lx references\n" 1070 "section \"%s\" which is not in the list of\n" 1071 "authorized sections. If you're adding a new section\n" 1072 "and/or if this reference is valid, add \"%s\" to the\n" 1073 "list of authorized sections to jump to on fault.\n" 1074 "This can be achieved by adding \"%s\" to\n" 1075 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1076 fromsec, (long)faddr, tosec, tosec, tosec); 1077 else 1078 error("%s+0x%lx references non-executable section '%s'\n", 1079 fromsec, (long)faddr, tosec); 1080 } 1081 } 1082 1083 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1084 Elf_Addr faddr, const char *secname, 1085 Elf_Sym *sym) 1086 { 1087 static const char *prefix = "__export_symbol_"; 1088 const char *label_name, *name, *data; 1089 Elf_Sym *label; 1090 struct symbol *s; 1091 bool is_gpl; 1092 1093 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1094 label_name = sym_name(elf, label); 1095 1096 if (!strstarts(label_name, prefix)) { 1097 error("%s: .export_symbol section contains strange symbol '%s'\n", 1098 mod->name, label_name); 1099 return; 1100 } 1101 1102 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1103 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1104 error("%s: local symbol '%s' was exported\n", mod->name, 1105 label_name + strlen(prefix)); 1106 return; 1107 } 1108 1109 name = sym_name(elf, sym); 1110 if (strcmp(label_name + strlen(prefix), name)) { 1111 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1112 mod->name, name); 1113 return; 1114 } 1115 1116 data = sym_get_data(elf, label); /* license */ 1117 if (!strcmp(data, "GPL")) { 1118 is_gpl = true; 1119 } else if (!strcmp(data, "")) { 1120 is_gpl = false; 1121 } else { 1122 error("%s: unknown license '%s' was specified for '%s'\n", 1123 mod->name, data, name); 1124 return; 1125 } 1126 1127 data += strlen(data) + 1; /* namespace */ 1128 s = sym_add_exported(name, mod, is_gpl, data); 1129 1130 /* 1131 * We need to be aware whether we are exporting a function or 1132 * a data on some architectures. 1133 */ 1134 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1135 1136 /* 1137 * For parisc64, symbols prefixed $$ from the library have the symbol type 1138 * STT_LOPROC. They should be handled as functions too. 1139 */ 1140 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1141 elf->hdr->e_machine == EM_PARISC && 1142 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1143 s->is_func = true; 1144 1145 if (match(secname, PATTERNS(ALL_INIT_SECTIONS))) 1146 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1147 mod->name, name); 1148 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS))) 1149 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1150 mod->name, name); 1151 } 1152 1153 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1154 Elf_Sym *sym, 1155 unsigned int fsecndx, const char *fromsec, 1156 Elf_Addr faddr, Elf_Addr taddr) 1157 { 1158 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1159 const struct sectioncheck *mismatch; 1160 1161 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1162 check_export_symbol(mod, elf, faddr, tosec, sym); 1163 return; 1164 } 1165 1166 mismatch = section_mismatch(fromsec, tosec); 1167 if (!mismatch) 1168 return; 1169 1170 default_mismatch_handler(mod->name, elf, mismatch, sym, 1171 fsecndx, fromsec, faddr, 1172 tosec, taddr); 1173 } 1174 1175 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1176 { 1177 switch (r_type) { 1178 case R_386_32: 1179 return TO_NATIVE(*location); 1180 case R_386_PC32: 1181 return TO_NATIVE(*location) + 4; 1182 } 1183 1184 return (Elf_Addr)(-1); 1185 } 1186 1187 #ifndef R_ARM_CALL 1188 #define R_ARM_CALL 28 1189 #endif 1190 #ifndef R_ARM_JUMP24 1191 #define R_ARM_JUMP24 29 1192 #endif 1193 1194 #ifndef R_ARM_THM_CALL 1195 #define R_ARM_THM_CALL 10 1196 #endif 1197 #ifndef R_ARM_THM_JUMP24 1198 #define R_ARM_THM_JUMP24 30 1199 #endif 1200 1201 #ifndef R_ARM_MOVW_ABS_NC 1202 #define R_ARM_MOVW_ABS_NC 43 1203 #endif 1204 1205 #ifndef R_ARM_MOVT_ABS 1206 #define R_ARM_MOVT_ABS 44 1207 #endif 1208 1209 #ifndef R_ARM_THM_MOVW_ABS_NC 1210 #define R_ARM_THM_MOVW_ABS_NC 47 1211 #endif 1212 1213 #ifndef R_ARM_THM_MOVT_ABS 1214 #define R_ARM_THM_MOVT_ABS 48 1215 #endif 1216 1217 #ifndef R_ARM_THM_JUMP19 1218 #define R_ARM_THM_JUMP19 51 1219 #endif 1220 1221 static int32_t sign_extend32(int32_t value, int index) 1222 { 1223 uint8_t shift = 31 - index; 1224 1225 return (int32_t)(value << shift) >> shift; 1226 } 1227 1228 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1229 { 1230 uint32_t inst, upper, lower, sign, j1, j2; 1231 int32_t offset; 1232 1233 switch (r_type) { 1234 case R_ARM_ABS32: 1235 case R_ARM_REL32: 1236 inst = TO_NATIVE(*(uint32_t *)loc); 1237 return inst + sym->st_value; 1238 case R_ARM_MOVW_ABS_NC: 1239 case R_ARM_MOVT_ABS: 1240 inst = TO_NATIVE(*(uint32_t *)loc); 1241 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1242 15); 1243 return offset + sym->st_value; 1244 case R_ARM_PC24: 1245 case R_ARM_CALL: 1246 case R_ARM_JUMP24: 1247 inst = TO_NATIVE(*(uint32_t *)loc); 1248 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1249 return offset + sym->st_value + 8; 1250 case R_ARM_THM_MOVW_ABS_NC: 1251 case R_ARM_THM_MOVT_ABS: 1252 upper = TO_NATIVE(*(uint16_t *)loc); 1253 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1254 offset = sign_extend32(((upper & 0x000f) << 12) | 1255 ((upper & 0x0400) << 1) | 1256 ((lower & 0x7000) >> 4) | 1257 (lower & 0x00ff), 1258 15); 1259 return offset + sym->st_value; 1260 case R_ARM_THM_JUMP19: 1261 /* 1262 * Encoding T3: 1263 * S = upper[10] 1264 * imm6 = upper[5:0] 1265 * J1 = lower[13] 1266 * J2 = lower[11] 1267 * imm11 = lower[10:0] 1268 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1269 */ 1270 upper = TO_NATIVE(*(uint16_t *)loc); 1271 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1272 1273 sign = (upper >> 10) & 1; 1274 j1 = (lower >> 13) & 1; 1275 j2 = (lower >> 11) & 1; 1276 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1277 ((upper & 0x03f) << 12) | 1278 ((lower & 0x07ff) << 1), 1279 20); 1280 return offset + sym->st_value + 4; 1281 case R_ARM_THM_CALL: 1282 case R_ARM_THM_JUMP24: 1283 /* 1284 * Encoding T4: 1285 * S = upper[10] 1286 * imm10 = upper[9:0] 1287 * J1 = lower[13] 1288 * J2 = lower[11] 1289 * imm11 = lower[10:0] 1290 * I1 = NOT(J1 XOR S) 1291 * I2 = NOT(J2 XOR S) 1292 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1293 */ 1294 upper = TO_NATIVE(*(uint16_t *)loc); 1295 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1296 1297 sign = (upper >> 10) & 1; 1298 j1 = (lower >> 13) & 1; 1299 j2 = (lower >> 11) & 1; 1300 offset = sign_extend32((sign << 24) | 1301 ((~(j1 ^ sign) & 1) << 23) | 1302 ((~(j2 ^ sign) & 1) << 22) | 1303 ((upper & 0x03ff) << 12) | 1304 ((lower & 0x07ff) << 1), 1305 24); 1306 return offset + sym->st_value + 4; 1307 } 1308 1309 return (Elf_Addr)(-1); 1310 } 1311 1312 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1313 { 1314 uint32_t inst; 1315 1316 inst = TO_NATIVE(*location); 1317 switch (r_type) { 1318 case R_MIPS_LO16: 1319 return inst & 0xffff; 1320 case R_MIPS_26: 1321 return (inst & 0x03ffffff) << 2; 1322 case R_MIPS_32: 1323 return inst; 1324 } 1325 return (Elf_Addr)(-1); 1326 } 1327 1328 #ifndef EM_RISCV 1329 #define EM_RISCV 243 1330 #endif 1331 1332 #ifndef R_RISCV_SUB32 1333 #define R_RISCV_SUB32 39 1334 #endif 1335 1336 #ifndef EM_LOONGARCH 1337 #define EM_LOONGARCH 258 1338 #endif 1339 1340 #ifndef R_LARCH_SUB32 1341 #define R_LARCH_SUB32 55 1342 #endif 1343 1344 #ifndef R_LARCH_RELAX 1345 #define R_LARCH_RELAX 100 1346 #endif 1347 1348 #ifndef R_LARCH_ALIGN 1349 #define R_LARCH_ALIGN 102 1350 #endif 1351 1352 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1353 unsigned int *r_type, unsigned int *r_sym) 1354 { 1355 typedef struct { 1356 Elf64_Word r_sym; /* Symbol index */ 1357 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1358 unsigned char r_type3; /* 3rd relocation type */ 1359 unsigned char r_type2; /* 2nd relocation type */ 1360 unsigned char r_type; /* 1st relocation type */ 1361 } Elf64_Mips_R_Info; 1362 1363 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1364 1365 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1366 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1367 1368 *r_type = mips64_r_info->r_type; 1369 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1370 return; 1371 } 1372 1373 if (is_64bit) 1374 r_info = TO_NATIVE((Elf64_Xword)r_info); 1375 else 1376 r_info = TO_NATIVE((Elf32_Word)r_info); 1377 1378 *r_type = ELF_R_TYPE(r_info); 1379 *r_sym = ELF_R_SYM(r_info); 1380 } 1381 1382 static void section_rela(struct module *mod, struct elf_info *elf, 1383 unsigned int fsecndx, const char *fromsec, 1384 const Elf_Rela *start, const Elf_Rela *stop) 1385 { 1386 const Elf_Rela *rela; 1387 1388 for (rela = start; rela < stop; rela++) { 1389 Elf_Sym *tsym; 1390 Elf_Addr taddr, r_offset; 1391 unsigned int r_type, r_sym; 1392 1393 r_offset = TO_NATIVE(rela->r_offset); 1394 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1395 1396 tsym = elf->symtab_start + r_sym; 1397 taddr = tsym->st_value + TO_NATIVE(rela->r_addend); 1398 1399 switch (elf->hdr->e_machine) { 1400 case EM_RISCV: 1401 if (!strcmp("__ex_table", fromsec) && 1402 r_type == R_RISCV_SUB32) 1403 continue; 1404 break; 1405 case EM_LOONGARCH: 1406 switch (r_type) { 1407 case R_LARCH_SUB32: 1408 if (!strcmp("__ex_table", fromsec)) 1409 continue; 1410 break; 1411 case R_LARCH_RELAX: 1412 case R_LARCH_ALIGN: 1413 /* These relocs do not refer to symbols */ 1414 continue; 1415 } 1416 break; 1417 } 1418 1419 check_section_mismatch(mod, elf, tsym, 1420 fsecndx, fromsec, r_offset, taddr); 1421 } 1422 } 1423 1424 static void section_rel(struct module *mod, struct elf_info *elf, 1425 unsigned int fsecndx, const char *fromsec, 1426 const Elf_Rel *start, const Elf_Rel *stop) 1427 { 1428 const Elf_Rel *rel; 1429 1430 for (rel = start; rel < stop; rel++) { 1431 Elf_Sym *tsym; 1432 Elf_Addr taddr, r_offset; 1433 unsigned int r_type, r_sym; 1434 void *loc; 1435 1436 r_offset = TO_NATIVE(rel->r_offset); 1437 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1438 1439 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1440 tsym = elf->symtab_start + r_sym; 1441 1442 switch (elf->hdr->e_machine) { 1443 case EM_386: 1444 taddr = addend_386_rel(loc, r_type); 1445 break; 1446 case EM_ARM: 1447 taddr = addend_arm_rel(loc, tsym, r_type); 1448 break; 1449 case EM_MIPS: 1450 taddr = addend_mips_rel(loc, r_type); 1451 break; 1452 default: 1453 fatal("Please add code to calculate addend for this architecture\n"); 1454 } 1455 1456 check_section_mismatch(mod, elf, tsym, 1457 fsecndx, fromsec, r_offset, taddr); 1458 } 1459 } 1460 1461 /** 1462 * A module includes a number of sections that are discarded 1463 * either when loaded or when used as built-in. 1464 * For loaded modules all functions marked __init and all data 1465 * marked __initdata will be discarded when the module has been initialized. 1466 * Likewise for modules used built-in the sections marked __exit 1467 * are discarded because __exit marked function are supposed to be called 1468 * only when a module is unloaded which never happens for built-in modules. 1469 * The check_sec_ref() function traverses all relocation records 1470 * to find all references to a section that reference a section that will 1471 * be discarded and warns about it. 1472 **/ 1473 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1474 { 1475 int i; 1476 1477 /* Walk through all sections */ 1478 for (i = 0; i < elf->num_sections; i++) { 1479 Elf_Shdr *sechdr = &elf->sechdrs[i]; 1480 1481 check_section(mod->name, elf, sechdr); 1482 /* We want to process only relocation sections and not .init */ 1483 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) { 1484 /* section to which the relocation applies */ 1485 unsigned int secndx = sechdr->sh_info; 1486 const char *secname = sec_name(elf, secndx); 1487 const void *start, *stop; 1488 1489 /* If the section is known good, skip it */ 1490 if (match(secname, section_white_list)) 1491 continue; 1492 1493 start = sym_get_data_by_offset(elf, i, 0); 1494 stop = start + sechdr->sh_size; 1495 1496 if (sechdr->sh_type == SHT_RELA) 1497 section_rela(mod, elf, secndx, secname, 1498 start, stop); 1499 else 1500 section_rel(mod, elf, secndx, secname, 1501 start, stop); 1502 } 1503 } 1504 } 1505 1506 static char *remove_dot(char *s) 1507 { 1508 size_t n = strcspn(s, "."); 1509 1510 if (n && s[n]) { 1511 size_t m = strspn(s + n + 1, "0123456789"); 1512 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1513 s[n] = 0; 1514 } 1515 return s; 1516 } 1517 1518 /* 1519 * The CRCs are recorded in .*.cmd files in the form of: 1520 * #SYMVER <name> <crc> 1521 */ 1522 static void extract_crcs_for_object(const char *object, struct module *mod) 1523 { 1524 char cmd_file[PATH_MAX]; 1525 char *buf, *p; 1526 const char *base; 1527 int dirlen, ret; 1528 1529 base = strrchr(object, '/'); 1530 if (base) { 1531 base++; 1532 dirlen = base - object; 1533 } else { 1534 dirlen = 0; 1535 base = object; 1536 } 1537 1538 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1539 dirlen, object, base); 1540 if (ret >= sizeof(cmd_file)) { 1541 error("%s: too long path was truncated\n", cmd_file); 1542 return; 1543 } 1544 1545 buf = read_text_file(cmd_file); 1546 p = buf; 1547 1548 while ((p = strstr(p, "\n#SYMVER "))) { 1549 char *name; 1550 size_t namelen; 1551 unsigned int crc; 1552 struct symbol *sym; 1553 1554 name = p + strlen("\n#SYMVER "); 1555 1556 p = strchr(name, ' '); 1557 if (!p) 1558 break; 1559 1560 namelen = p - name; 1561 p++; 1562 1563 if (!isdigit(*p)) 1564 continue; /* skip this line */ 1565 1566 crc = strtoul(p, &p, 0); 1567 if (*p != '\n') 1568 continue; /* skip this line */ 1569 1570 name[namelen] = '\0'; 1571 1572 /* 1573 * sym_find_with_module() may return NULL here. 1574 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1575 * Since commit e1327a127703, genksyms calculates CRCs of all 1576 * symbols, including trimmed ones. Ignore orphan CRCs. 1577 */ 1578 sym = sym_find_with_module(name, mod); 1579 if (sym) 1580 sym_set_crc(sym, crc); 1581 } 1582 1583 free(buf); 1584 } 1585 1586 /* 1587 * The symbol versions (CRC) are recorded in the .*.cmd files. 1588 * Parse them to retrieve CRCs for the current module. 1589 */ 1590 static void mod_set_crcs(struct module *mod) 1591 { 1592 char objlist[PATH_MAX]; 1593 char *buf, *p, *obj; 1594 int ret; 1595 1596 if (mod->is_vmlinux) { 1597 strcpy(objlist, ".vmlinux.objs"); 1598 } else { 1599 /* objects for a module are listed in the *.mod file. */ 1600 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1601 if (ret >= sizeof(objlist)) { 1602 error("%s: too long path was truncated\n", objlist); 1603 return; 1604 } 1605 } 1606 1607 buf = read_text_file(objlist); 1608 p = buf; 1609 1610 while ((obj = strsep(&p, "\n")) && obj[0]) 1611 extract_crcs_for_object(obj, mod); 1612 1613 free(buf); 1614 } 1615 1616 static void read_symbols(const char *modname) 1617 { 1618 const char *symname; 1619 char *version; 1620 char *license; 1621 char *namespace; 1622 struct module *mod; 1623 struct elf_info info = { }; 1624 Elf_Sym *sym; 1625 1626 if (!parse_elf(&info, modname)) 1627 return; 1628 1629 if (!strends(modname, ".o")) { 1630 error("%s: filename must be suffixed with .o\n", modname); 1631 return; 1632 } 1633 1634 /* strip trailing .o */ 1635 mod = new_module(modname, strlen(modname) - strlen(".o")); 1636 1637 if (!mod->is_vmlinux) { 1638 license = get_modinfo(&info, "license"); 1639 if (!license) 1640 error("missing MODULE_LICENSE() in %s\n", modname); 1641 while (license) { 1642 if (!license_is_gpl_compatible(license)) { 1643 mod->is_gpl_compatible = false; 1644 break; 1645 } 1646 license = get_next_modinfo(&info, "license", license); 1647 } 1648 1649 namespace = get_modinfo(&info, "import_ns"); 1650 while (namespace) { 1651 add_namespace(&mod->imported_namespaces, namespace); 1652 namespace = get_next_modinfo(&info, "import_ns", 1653 namespace); 1654 } 1655 } 1656 1657 if (extra_warn && !get_modinfo(&info, "description")) 1658 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1659 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1660 symname = remove_dot(info.strtab + sym->st_name); 1661 1662 handle_symbol(mod, &info, sym, symname); 1663 handle_moddevtable(mod, &info, sym, symname); 1664 } 1665 1666 check_sec_ref(mod, &info); 1667 1668 if (!mod->is_vmlinux) { 1669 version = get_modinfo(&info, "version"); 1670 if (version || all_versions) 1671 get_src_version(mod->name, mod->srcversion, 1672 sizeof(mod->srcversion) - 1); 1673 } 1674 1675 parse_elf_finish(&info); 1676 1677 if (modversions) { 1678 /* 1679 * Our trick to get versioning for module struct etc. - it's 1680 * never passed as an argument to an exported function, so 1681 * the automatic versioning doesn't pick it up, but it's really 1682 * important anyhow. 1683 */ 1684 sym_add_unresolved("module_layout", mod, false); 1685 1686 mod_set_crcs(mod); 1687 } 1688 } 1689 1690 static void read_symbols_from_files(const char *filename) 1691 { 1692 FILE *in = stdin; 1693 char fname[PATH_MAX]; 1694 1695 in = fopen(filename, "r"); 1696 if (!in) 1697 fatal("Can't open filenames file %s: %m", filename); 1698 1699 while (fgets(fname, PATH_MAX, in) != NULL) { 1700 if (strends(fname, "\n")) 1701 fname[strlen(fname)-1] = '\0'; 1702 read_symbols(fname); 1703 } 1704 1705 fclose(in); 1706 } 1707 1708 #define SZ 500 1709 1710 /* We first write the generated file into memory using the 1711 * following helper, then compare to the file on disk and 1712 * only update the later if anything changed */ 1713 1714 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1715 const char *fmt, ...) 1716 { 1717 char tmp[SZ]; 1718 int len; 1719 va_list ap; 1720 1721 va_start(ap, fmt); 1722 len = vsnprintf(tmp, SZ, fmt, ap); 1723 buf_write(buf, tmp, len); 1724 va_end(ap); 1725 } 1726 1727 void buf_write(struct buffer *buf, const char *s, int len) 1728 { 1729 if (buf->size - buf->pos < len) { 1730 buf->size += len + SZ; 1731 buf->p = NOFAIL(realloc(buf->p, buf->size)); 1732 } 1733 strncpy(buf->p + buf->pos, s, len); 1734 buf->pos += len; 1735 } 1736 1737 static void check_exports(struct module *mod) 1738 { 1739 struct symbol *s, *exp; 1740 1741 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1742 const char *basename; 1743 exp = find_symbol(s->name); 1744 if (!exp) { 1745 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1746 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, 1747 "\"%s\" [%s.ko] undefined!\n", 1748 s->name, mod->name); 1749 continue; 1750 } 1751 if (exp->module == mod) { 1752 error("\"%s\" [%s.ko] was exported without definition\n", 1753 s->name, mod->name); 1754 continue; 1755 } 1756 1757 exp->used = true; 1758 s->module = exp->module; 1759 s->crc_valid = exp->crc_valid; 1760 s->crc = exp->crc; 1761 1762 basename = strrchr(mod->name, '/'); 1763 if (basename) 1764 basename++; 1765 else 1766 basename = mod->name; 1767 1768 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1769 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, 1770 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1771 basename, exp->name, exp->namespace); 1772 add_namespace(&mod->missing_namespaces, exp->namespace); 1773 } 1774 1775 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1776 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1777 basename, exp->name); 1778 } 1779 } 1780 1781 static void handle_white_list_exports(const char *white_list) 1782 { 1783 char *buf, *p, *name; 1784 1785 buf = read_text_file(white_list); 1786 p = buf; 1787 1788 while ((name = strsep(&p, "\n"))) { 1789 struct symbol *sym = find_symbol(name); 1790 1791 if (sym) 1792 sym->used = true; 1793 } 1794 1795 free(buf); 1796 } 1797 1798 static void check_modname_len(struct module *mod) 1799 { 1800 const char *mod_name; 1801 1802 mod_name = strrchr(mod->name, '/'); 1803 if (mod_name == NULL) 1804 mod_name = mod->name; 1805 else 1806 mod_name++; 1807 if (strlen(mod_name) >= MODULE_NAME_LEN) 1808 error("module name is too long [%s.ko]\n", mod->name); 1809 } 1810 1811 /** 1812 * Header for the generated file 1813 **/ 1814 static void add_header(struct buffer *b, struct module *mod) 1815 { 1816 buf_printf(b, "#include <linux/module.h>\n"); 1817 /* 1818 * Include build-salt.h after module.h in order to 1819 * inherit the definitions. 1820 */ 1821 buf_printf(b, "#define INCLUDE_VERMAGIC\n"); 1822 buf_printf(b, "#include <linux/build-salt.h>\n"); 1823 buf_printf(b, "#include <linux/elfnote-lto.h>\n"); 1824 buf_printf(b, "#include <linux/export-internal.h>\n"); 1825 buf_printf(b, "#include <linux/vermagic.h>\n"); 1826 buf_printf(b, "#include <linux/compiler.h>\n"); 1827 buf_printf(b, "\n"); 1828 buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n"); 1829 buf_printf(b, "#include <asm/orc_header.h>\n"); 1830 buf_printf(b, "ORC_HEADER;\n"); 1831 buf_printf(b, "#endif\n"); 1832 buf_printf(b, "\n"); 1833 buf_printf(b, "BUILD_SALT;\n"); 1834 buf_printf(b, "BUILD_LTO_INFO;\n"); 1835 buf_printf(b, "\n"); 1836 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1837 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1838 buf_printf(b, "\n"); 1839 buf_printf(b, "__visible struct module __this_module\n"); 1840 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1841 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1842 if (mod->has_init) 1843 buf_printf(b, "\t.init = init_module,\n"); 1844 if (mod->has_cleanup) 1845 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1846 "\t.exit = cleanup_module,\n" 1847 "#endif\n"); 1848 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1849 buf_printf(b, "};\n"); 1850 1851 if (!external_module) 1852 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1853 1854 buf_printf(b, 1855 "\n" 1856 "#ifdef CONFIG_MITIGATION_RETPOLINE\n" 1857 "MODULE_INFO(retpoline, \"Y\");\n" 1858 "#endif\n"); 1859 1860 if (strstarts(mod->name, "drivers/staging")) 1861 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1862 1863 if (strstarts(mod->name, "tools/testing")) 1864 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1865 } 1866 1867 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1868 { 1869 struct symbol *sym; 1870 1871 /* generate struct for exported symbols */ 1872 buf_printf(buf, "\n"); 1873 list_for_each_entry(sym, &mod->exported_symbols, list) { 1874 if (trim_unused_exports && !sym->used) 1875 continue; 1876 1877 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1878 sym->is_func ? "FUNC" : "DATA", sym->name, 1879 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1880 } 1881 1882 if (!modversions) 1883 return; 1884 1885 /* record CRCs for exported symbols */ 1886 buf_printf(buf, "\n"); 1887 list_for_each_entry(sym, &mod->exported_symbols, list) { 1888 if (trim_unused_exports && !sym->used) 1889 continue; 1890 1891 if (!sym->crc_valid) 1892 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1893 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1894 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1895 sym->name); 1896 1897 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1898 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1899 } 1900 } 1901 1902 /** 1903 * Record CRCs for unresolved symbols 1904 **/ 1905 static void add_versions(struct buffer *b, struct module *mod) 1906 { 1907 struct symbol *s; 1908 1909 if (!modversions) 1910 return; 1911 1912 buf_printf(b, "\n"); 1913 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1914 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1915 1916 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1917 if (!s->module) 1918 continue; 1919 if (!s->crc_valid) { 1920 warn("\"%s\" [%s.ko] has no CRC!\n", 1921 s->name, mod->name); 1922 continue; 1923 } 1924 if (strlen(s->name) >= MODULE_NAME_LEN) { 1925 error("too long symbol \"%s\" [%s.ko]\n", 1926 s->name, mod->name); 1927 break; 1928 } 1929 buf_printf(b, "\t{ %#8x, \"%s\" },\n", 1930 s->crc, s->name); 1931 } 1932 1933 buf_printf(b, "};\n"); 1934 } 1935 1936 static void add_depends(struct buffer *b, struct module *mod) 1937 { 1938 struct symbol *s; 1939 int first = 1; 1940 1941 /* Clear ->seen flag of modules that own symbols needed by this. */ 1942 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1943 if (s->module) 1944 s->module->seen = s->module->is_vmlinux; 1945 } 1946 1947 buf_printf(b, "\n"); 1948 buf_printf(b, "MODULE_INFO(depends, \""); 1949 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1950 const char *p; 1951 if (!s->module) 1952 continue; 1953 1954 if (s->module->seen) 1955 continue; 1956 1957 s->module->seen = true; 1958 p = strrchr(s->module->name, '/'); 1959 if (p) 1960 p++; 1961 else 1962 p = s->module->name; 1963 buf_printf(b, "%s%s", first ? "" : ",", p); 1964 first = 0; 1965 } 1966 buf_printf(b, "\");\n"); 1967 } 1968 1969 static void add_srcversion(struct buffer *b, struct module *mod) 1970 { 1971 if (mod->srcversion[0]) { 1972 buf_printf(b, "\n"); 1973 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1974 mod->srcversion); 1975 } 1976 } 1977 1978 static void write_buf(struct buffer *b, const char *fname) 1979 { 1980 FILE *file; 1981 1982 if (error_occurred) 1983 return; 1984 1985 file = fopen(fname, "w"); 1986 if (!file) { 1987 perror(fname); 1988 exit(1); 1989 } 1990 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1991 perror(fname); 1992 exit(1); 1993 } 1994 if (fclose(file) != 0) { 1995 perror(fname); 1996 exit(1); 1997 } 1998 } 1999 2000 static void write_if_changed(struct buffer *b, const char *fname) 2001 { 2002 char *tmp; 2003 FILE *file; 2004 struct stat st; 2005 2006 file = fopen(fname, "r"); 2007 if (!file) 2008 goto write; 2009 2010 if (fstat(fileno(file), &st) < 0) 2011 goto close_write; 2012 2013 if (st.st_size != b->pos) 2014 goto close_write; 2015 2016 tmp = NOFAIL(malloc(b->pos)); 2017 if (fread(tmp, 1, b->pos, file) != b->pos) 2018 goto free_write; 2019 2020 if (memcmp(tmp, b->p, b->pos) != 0) 2021 goto free_write; 2022 2023 free(tmp); 2024 fclose(file); 2025 return; 2026 2027 free_write: 2028 free(tmp); 2029 close_write: 2030 fclose(file); 2031 write: 2032 write_buf(b, fname); 2033 } 2034 2035 static void write_vmlinux_export_c_file(struct module *mod) 2036 { 2037 struct buffer buf = { }; 2038 2039 buf_printf(&buf, 2040 "#include <linux/export-internal.h>\n"); 2041 2042 add_exported_symbols(&buf, mod); 2043 write_if_changed(&buf, ".vmlinux.export.c"); 2044 free(buf.p); 2045 } 2046 2047 /* do sanity checks, and generate *.mod.c file */ 2048 static void write_mod_c_file(struct module *mod) 2049 { 2050 struct buffer buf = { }; 2051 char fname[PATH_MAX]; 2052 int ret; 2053 2054 add_header(&buf, mod); 2055 add_exported_symbols(&buf, mod); 2056 add_versions(&buf, mod); 2057 add_depends(&buf, mod); 2058 add_moddevtable(&buf, mod); 2059 add_srcversion(&buf, mod); 2060 2061 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2062 if (ret >= sizeof(fname)) { 2063 error("%s: too long path was truncated\n", fname); 2064 goto free; 2065 } 2066 2067 write_if_changed(&buf, fname); 2068 2069 free: 2070 free(buf.p); 2071 } 2072 2073 /* parse Module.symvers file. line format: 2074 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2075 **/ 2076 static void read_dump(const char *fname) 2077 { 2078 char *buf, *pos, *line; 2079 2080 buf = read_text_file(fname); 2081 if (!buf) 2082 /* No symbol versions, silently ignore */ 2083 return; 2084 2085 pos = buf; 2086 2087 while ((line = get_line(&pos))) { 2088 char *symname, *namespace, *modname, *d, *export; 2089 unsigned int crc; 2090 struct module *mod; 2091 struct symbol *s; 2092 bool gpl_only; 2093 2094 if (!(symname = strchr(line, '\t'))) 2095 goto fail; 2096 *symname++ = '\0'; 2097 if (!(modname = strchr(symname, '\t'))) 2098 goto fail; 2099 *modname++ = '\0'; 2100 if (!(export = strchr(modname, '\t'))) 2101 goto fail; 2102 *export++ = '\0'; 2103 if (!(namespace = strchr(export, '\t'))) 2104 goto fail; 2105 *namespace++ = '\0'; 2106 2107 crc = strtoul(line, &d, 16); 2108 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2109 goto fail; 2110 2111 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2112 gpl_only = true; 2113 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2114 gpl_only = false; 2115 } else { 2116 error("%s: unknown license %s. skip", symname, export); 2117 continue; 2118 } 2119 2120 mod = find_module(modname); 2121 if (!mod) { 2122 mod = new_module(modname, strlen(modname)); 2123 mod->from_dump = true; 2124 } 2125 s = sym_add_exported(symname, mod, gpl_only, namespace); 2126 sym_set_crc(s, crc); 2127 } 2128 free(buf); 2129 return; 2130 fail: 2131 free(buf); 2132 fatal("parse error in symbol dump file\n"); 2133 } 2134 2135 static void write_dump(const char *fname) 2136 { 2137 struct buffer buf = { }; 2138 struct module *mod; 2139 struct symbol *sym; 2140 2141 list_for_each_entry(mod, &modules, list) { 2142 if (mod->from_dump) 2143 continue; 2144 list_for_each_entry(sym, &mod->exported_symbols, list) { 2145 if (trim_unused_exports && !sym->used) 2146 continue; 2147 2148 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2149 sym->crc, sym->name, mod->name, 2150 sym->is_gpl_only ? "_GPL" : "", 2151 sym->namespace); 2152 } 2153 } 2154 write_buf(&buf, fname); 2155 free(buf.p); 2156 } 2157 2158 static void write_namespace_deps_files(const char *fname) 2159 { 2160 struct module *mod; 2161 struct namespace_list *ns; 2162 struct buffer ns_deps_buf = {}; 2163 2164 list_for_each_entry(mod, &modules, list) { 2165 2166 if (mod->from_dump || list_empty(&mod->missing_namespaces)) 2167 continue; 2168 2169 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2170 2171 list_for_each_entry(ns, &mod->missing_namespaces, list) 2172 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2173 2174 buf_printf(&ns_deps_buf, "\n"); 2175 } 2176 2177 write_if_changed(&ns_deps_buf, fname); 2178 free(ns_deps_buf.p); 2179 } 2180 2181 struct dump_list { 2182 struct list_head list; 2183 const char *file; 2184 }; 2185 2186 int main(int argc, char **argv) 2187 { 2188 struct module *mod; 2189 char *missing_namespace_deps = NULL; 2190 char *unused_exports_white_list = NULL; 2191 char *dump_write = NULL, *files_source = NULL; 2192 int opt; 2193 LIST_HEAD(dump_lists); 2194 struct dump_list *dl, *dl2; 2195 2196 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) { 2197 switch (opt) { 2198 case 'e': 2199 external_module = true; 2200 break; 2201 case 'i': 2202 dl = NOFAIL(malloc(sizeof(*dl))); 2203 dl->file = optarg; 2204 list_add_tail(&dl->list, &dump_lists); 2205 break; 2206 case 'M': 2207 module_enabled = true; 2208 break; 2209 case 'm': 2210 modversions = true; 2211 break; 2212 case 'n': 2213 ignore_missing_files = true; 2214 break; 2215 case 'o': 2216 dump_write = optarg; 2217 break; 2218 case 'a': 2219 all_versions = true; 2220 break; 2221 case 'T': 2222 files_source = optarg; 2223 break; 2224 case 't': 2225 trim_unused_exports = true; 2226 break; 2227 case 'u': 2228 unused_exports_white_list = optarg; 2229 break; 2230 case 'W': 2231 extra_warn = true; 2232 break; 2233 case 'w': 2234 warn_unresolved = true; 2235 break; 2236 case 'E': 2237 sec_mismatch_warn_only = false; 2238 break; 2239 case 'N': 2240 allow_missing_ns_imports = true; 2241 break; 2242 case 'd': 2243 missing_namespace_deps = optarg; 2244 break; 2245 default: 2246 exit(1); 2247 } 2248 } 2249 2250 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2251 read_dump(dl->file); 2252 list_del(&dl->list); 2253 free(dl); 2254 } 2255 2256 while (optind < argc) 2257 read_symbols(argv[optind++]); 2258 2259 if (files_source) 2260 read_symbols_from_files(files_source); 2261 2262 list_for_each_entry(mod, &modules, list) { 2263 if (mod->from_dump || mod->is_vmlinux) 2264 continue; 2265 2266 check_modname_len(mod); 2267 check_exports(mod); 2268 } 2269 2270 if (unused_exports_white_list) 2271 handle_white_list_exports(unused_exports_white_list); 2272 2273 list_for_each_entry(mod, &modules, list) { 2274 if (mod->from_dump) 2275 continue; 2276 2277 if (mod->is_vmlinux) 2278 write_vmlinux_export_c_file(mod); 2279 else 2280 write_mod_c_file(mod); 2281 } 2282 2283 if (missing_namespace_deps) 2284 write_namespace_deps_files(missing_namespace_deps); 2285 2286 if (dump_write) 2287 write_dump(dump_write); 2288 if (sec_mismatch_count && !sec_mismatch_warn_only) 2289 error("Section mismatches detected.\n" 2290 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2291 2292 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2293 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2294 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2295 2296 return error_occurred ? 1 : 0; 2297 } 2298