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 /* If the supplied symbol has a valid name, return it */ 1011 if (is_valid_name(elf, sym)) 1012 return sym; 1013 1014 /* 1015 * Strive to find a better symbol name, but the resulting name may not 1016 * match the symbol referenced in the original code. 1017 */ 1018 return symsearch_find_nearest(elf, addr, get_secindex(elf, sym), 1019 true, 20); 1020 } 1021 1022 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1023 { 1024 if (secndx >= elf->num_sections) 1025 return false; 1026 1027 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1028 } 1029 1030 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1031 const struct sectioncheck* const mismatch, 1032 Elf_Sym *tsym, 1033 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1034 const char *tosec, Elf_Addr taddr) 1035 { 1036 Elf_Sym *from; 1037 const char *tosym; 1038 const char *fromsym; 1039 1040 from = find_fromsym(elf, faddr, fsecndx); 1041 fromsym = sym_name(elf, from); 1042 1043 tsym = find_tosym(elf, taddr, tsym); 1044 tosym = sym_name(elf, tsym); 1045 1046 /* check whitelist - we may ignore it */ 1047 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1048 return; 1049 1050 sec_mismatch_count++; 1051 1052 warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n", 1053 modname, fromsym, 1054 (unsigned int)(faddr - (from ? from->st_value : 0)), 1055 fromsec, tosym, tosec); 1056 1057 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1058 if (match(tosec, mismatch->bad_tosec)) 1059 fatal("The relocation at %s+0x%lx references\n" 1060 "section \"%s\" which is black-listed.\n" 1061 "Something is seriously wrong and should be fixed.\n" 1062 "You might get more information about where this is\n" 1063 "coming from by using scripts/check_extable.sh %s\n", 1064 fromsec, (long)faddr, tosec, modname); 1065 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1066 warn("The relocation at %s+0x%lx references\n" 1067 "section \"%s\" which is not in the list of\n" 1068 "authorized sections. If you're adding a new section\n" 1069 "and/or if this reference is valid, add \"%s\" to the\n" 1070 "list of authorized sections to jump to on fault.\n" 1071 "This can be achieved by adding \"%s\" to\n" 1072 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1073 fromsec, (long)faddr, tosec, tosec, tosec); 1074 else 1075 error("%s+0x%lx references non-executable section '%s'\n", 1076 fromsec, (long)faddr, tosec); 1077 } 1078 } 1079 1080 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1081 Elf_Addr faddr, const char *secname, 1082 Elf_Sym *sym) 1083 { 1084 static const char *prefix = "__export_symbol_"; 1085 const char *label_name, *name, *data; 1086 Elf_Sym *label; 1087 struct symbol *s; 1088 bool is_gpl; 1089 1090 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1091 label_name = sym_name(elf, label); 1092 1093 if (!strstarts(label_name, prefix)) { 1094 error("%s: .export_symbol section contains strange symbol '%s'\n", 1095 mod->name, label_name); 1096 return; 1097 } 1098 1099 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1100 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1101 error("%s: local symbol '%s' was exported\n", mod->name, 1102 label_name + strlen(prefix)); 1103 return; 1104 } 1105 1106 name = sym_name(elf, sym); 1107 if (strcmp(label_name + strlen(prefix), name)) { 1108 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1109 mod->name, name); 1110 return; 1111 } 1112 1113 data = sym_get_data(elf, label); /* license */ 1114 if (!strcmp(data, "GPL")) { 1115 is_gpl = true; 1116 } else if (!strcmp(data, "")) { 1117 is_gpl = false; 1118 } else { 1119 error("%s: unknown license '%s' was specified for '%s'\n", 1120 mod->name, data, name); 1121 return; 1122 } 1123 1124 data += strlen(data) + 1; /* namespace */ 1125 s = sym_add_exported(name, mod, is_gpl, data); 1126 1127 /* 1128 * We need to be aware whether we are exporting a function or 1129 * a data on some architectures. 1130 */ 1131 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1132 1133 /* 1134 * For parisc64, symbols prefixed $$ from the library have the symbol type 1135 * STT_LOPROC. They should be handled as functions too. 1136 */ 1137 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1138 elf->hdr->e_machine == EM_PARISC && 1139 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1140 s->is_func = true; 1141 1142 if (match(secname, PATTERNS(ALL_INIT_SECTIONS))) 1143 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1144 mod->name, name); 1145 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS))) 1146 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1147 mod->name, name); 1148 } 1149 1150 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1151 Elf_Sym *sym, 1152 unsigned int fsecndx, const char *fromsec, 1153 Elf_Addr faddr, Elf_Addr taddr) 1154 { 1155 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1156 const struct sectioncheck *mismatch; 1157 1158 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1159 check_export_symbol(mod, elf, faddr, tosec, sym); 1160 return; 1161 } 1162 1163 mismatch = section_mismatch(fromsec, tosec); 1164 if (!mismatch) 1165 return; 1166 1167 default_mismatch_handler(mod->name, elf, mismatch, sym, 1168 fsecndx, fromsec, faddr, 1169 tosec, taddr); 1170 } 1171 1172 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1173 { 1174 switch (r_type) { 1175 case R_386_32: 1176 return TO_NATIVE(*location); 1177 case R_386_PC32: 1178 return TO_NATIVE(*location) + 4; 1179 } 1180 1181 return (Elf_Addr)(-1); 1182 } 1183 1184 #ifndef R_ARM_CALL 1185 #define R_ARM_CALL 28 1186 #endif 1187 #ifndef R_ARM_JUMP24 1188 #define R_ARM_JUMP24 29 1189 #endif 1190 1191 #ifndef R_ARM_THM_CALL 1192 #define R_ARM_THM_CALL 10 1193 #endif 1194 #ifndef R_ARM_THM_JUMP24 1195 #define R_ARM_THM_JUMP24 30 1196 #endif 1197 1198 #ifndef R_ARM_MOVW_ABS_NC 1199 #define R_ARM_MOVW_ABS_NC 43 1200 #endif 1201 1202 #ifndef R_ARM_MOVT_ABS 1203 #define R_ARM_MOVT_ABS 44 1204 #endif 1205 1206 #ifndef R_ARM_THM_MOVW_ABS_NC 1207 #define R_ARM_THM_MOVW_ABS_NC 47 1208 #endif 1209 1210 #ifndef R_ARM_THM_MOVT_ABS 1211 #define R_ARM_THM_MOVT_ABS 48 1212 #endif 1213 1214 #ifndef R_ARM_THM_JUMP19 1215 #define R_ARM_THM_JUMP19 51 1216 #endif 1217 1218 static int32_t sign_extend32(int32_t value, int index) 1219 { 1220 uint8_t shift = 31 - index; 1221 1222 return (int32_t)(value << shift) >> shift; 1223 } 1224 1225 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1226 { 1227 uint32_t inst, upper, lower, sign, j1, j2; 1228 int32_t offset; 1229 1230 switch (r_type) { 1231 case R_ARM_ABS32: 1232 case R_ARM_REL32: 1233 inst = TO_NATIVE(*(uint32_t *)loc); 1234 return inst + sym->st_value; 1235 case R_ARM_MOVW_ABS_NC: 1236 case R_ARM_MOVT_ABS: 1237 inst = TO_NATIVE(*(uint32_t *)loc); 1238 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1239 15); 1240 return offset + sym->st_value; 1241 case R_ARM_PC24: 1242 case R_ARM_CALL: 1243 case R_ARM_JUMP24: 1244 inst = TO_NATIVE(*(uint32_t *)loc); 1245 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1246 return offset + sym->st_value + 8; 1247 case R_ARM_THM_MOVW_ABS_NC: 1248 case R_ARM_THM_MOVT_ABS: 1249 upper = TO_NATIVE(*(uint16_t *)loc); 1250 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1251 offset = sign_extend32(((upper & 0x000f) << 12) | 1252 ((upper & 0x0400) << 1) | 1253 ((lower & 0x7000) >> 4) | 1254 (lower & 0x00ff), 1255 15); 1256 return offset + sym->st_value; 1257 case R_ARM_THM_JUMP19: 1258 /* 1259 * Encoding T3: 1260 * S = upper[10] 1261 * imm6 = upper[5:0] 1262 * J1 = lower[13] 1263 * J2 = lower[11] 1264 * imm11 = lower[10:0] 1265 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1266 */ 1267 upper = TO_NATIVE(*(uint16_t *)loc); 1268 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1269 1270 sign = (upper >> 10) & 1; 1271 j1 = (lower >> 13) & 1; 1272 j2 = (lower >> 11) & 1; 1273 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1274 ((upper & 0x03f) << 12) | 1275 ((lower & 0x07ff) << 1), 1276 20); 1277 return offset + sym->st_value + 4; 1278 case R_ARM_THM_CALL: 1279 case R_ARM_THM_JUMP24: 1280 /* 1281 * Encoding T4: 1282 * S = upper[10] 1283 * imm10 = upper[9:0] 1284 * J1 = lower[13] 1285 * J2 = lower[11] 1286 * imm11 = lower[10:0] 1287 * I1 = NOT(J1 XOR S) 1288 * I2 = NOT(J2 XOR S) 1289 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1290 */ 1291 upper = TO_NATIVE(*(uint16_t *)loc); 1292 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1293 1294 sign = (upper >> 10) & 1; 1295 j1 = (lower >> 13) & 1; 1296 j2 = (lower >> 11) & 1; 1297 offset = sign_extend32((sign << 24) | 1298 ((~(j1 ^ sign) & 1) << 23) | 1299 ((~(j2 ^ sign) & 1) << 22) | 1300 ((upper & 0x03ff) << 12) | 1301 ((lower & 0x07ff) << 1), 1302 24); 1303 return offset + sym->st_value + 4; 1304 } 1305 1306 return (Elf_Addr)(-1); 1307 } 1308 1309 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1310 { 1311 uint32_t inst; 1312 1313 inst = TO_NATIVE(*location); 1314 switch (r_type) { 1315 case R_MIPS_LO16: 1316 return inst & 0xffff; 1317 case R_MIPS_26: 1318 return (inst & 0x03ffffff) << 2; 1319 case R_MIPS_32: 1320 return inst; 1321 } 1322 return (Elf_Addr)(-1); 1323 } 1324 1325 #ifndef EM_RISCV 1326 #define EM_RISCV 243 1327 #endif 1328 1329 #ifndef R_RISCV_SUB32 1330 #define R_RISCV_SUB32 39 1331 #endif 1332 1333 #ifndef EM_LOONGARCH 1334 #define EM_LOONGARCH 258 1335 #endif 1336 1337 #ifndef R_LARCH_SUB32 1338 #define R_LARCH_SUB32 55 1339 #endif 1340 1341 #ifndef R_LARCH_RELAX 1342 #define R_LARCH_RELAX 100 1343 #endif 1344 1345 #ifndef R_LARCH_ALIGN 1346 #define R_LARCH_ALIGN 102 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_Sym *tsym; 1387 Elf_Addr taddr, r_offset; 1388 unsigned int r_type, r_sym; 1389 1390 r_offset = TO_NATIVE(rela->r_offset); 1391 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1392 1393 tsym = elf->symtab_start + r_sym; 1394 taddr = tsym->st_value + TO_NATIVE(rela->r_addend); 1395 1396 switch (elf->hdr->e_machine) { 1397 case EM_RISCV: 1398 if (!strcmp("__ex_table", fromsec) && 1399 r_type == R_RISCV_SUB32) 1400 continue; 1401 break; 1402 case EM_LOONGARCH: 1403 switch (r_type) { 1404 case R_LARCH_SUB32: 1405 if (!strcmp("__ex_table", fromsec)) 1406 continue; 1407 break; 1408 case R_LARCH_RELAX: 1409 case R_LARCH_ALIGN: 1410 /* These relocs do not refer to symbols */ 1411 continue; 1412 } 1413 break; 1414 } 1415 1416 check_section_mismatch(mod, elf, tsym, 1417 fsecndx, fromsec, r_offset, taddr); 1418 } 1419 } 1420 1421 static void section_rel(struct module *mod, struct elf_info *elf, 1422 unsigned int fsecndx, const char *fromsec, 1423 const Elf_Rel *start, const Elf_Rel *stop) 1424 { 1425 const Elf_Rel *rel; 1426 1427 for (rel = start; rel < stop; rel++) { 1428 Elf_Sym *tsym; 1429 Elf_Addr taddr, r_offset; 1430 unsigned int r_type, r_sym; 1431 void *loc; 1432 1433 r_offset = TO_NATIVE(rel->r_offset); 1434 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1435 1436 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1437 tsym = elf->symtab_start + r_sym; 1438 1439 switch (elf->hdr->e_machine) { 1440 case EM_386: 1441 taddr = addend_386_rel(loc, r_type); 1442 break; 1443 case EM_ARM: 1444 taddr = addend_arm_rel(loc, tsym, r_type); 1445 break; 1446 case EM_MIPS: 1447 taddr = addend_mips_rel(loc, r_type); 1448 break; 1449 default: 1450 fatal("Please add code to calculate addend for this architecture\n"); 1451 } 1452 1453 check_section_mismatch(mod, elf, tsym, 1454 fsecndx, fromsec, r_offset, taddr); 1455 } 1456 } 1457 1458 /** 1459 * A module includes a number of sections that are discarded 1460 * either when loaded or when used as built-in. 1461 * For loaded modules all functions marked __init and all data 1462 * marked __initdata will be discarded when the module has been initialized. 1463 * Likewise for modules used built-in the sections marked __exit 1464 * are discarded because __exit marked function are supposed to be called 1465 * only when a module is unloaded which never happens for built-in modules. 1466 * The check_sec_ref() function traverses all relocation records 1467 * to find all references to a section that reference a section that will 1468 * be discarded and warns about it. 1469 **/ 1470 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1471 { 1472 int i; 1473 1474 /* Walk through all sections */ 1475 for (i = 0; i < elf->num_sections; i++) { 1476 Elf_Shdr *sechdr = &elf->sechdrs[i]; 1477 1478 check_section(mod->name, elf, sechdr); 1479 /* We want to process only relocation sections and not .init */ 1480 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) { 1481 /* section to which the relocation applies */ 1482 unsigned int secndx = sechdr->sh_info; 1483 const char *secname = sec_name(elf, secndx); 1484 const void *start, *stop; 1485 1486 /* If the section is known good, skip it */ 1487 if (match(secname, section_white_list)) 1488 continue; 1489 1490 start = sym_get_data_by_offset(elf, i, 0); 1491 stop = start + sechdr->sh_size; 1492 1493 if (sechdr->sh_type == SHT_RELA) 1494 section_rela(mod, elf, secndx, secname, 1495 start, stop); 1496 else 1497 section_rel(mod, elf, secndx, secname, 1498 start, stop); 1499 } 1500 } 1501 } 1502 1503 static char *remove_dot(char *s) 1504 { 1505 size_t n = strcspn(s, "."); 1506 1507 if (n && s[n]) { 1508 size_t m = strspn(s + n + 1, "0123456789"); 1509 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1510 s[n] = 0; 1511 } 1512 return s; 1513 } 1514 1515 /* 1516 * The CRCs are recorded in .*.cmd files in the form of: 1517 * #SYMVER <name> <crc> 1518 */ 1519 static void extract_crcs_for_object(const char *object, struct module *mod) 1520 { 1521 char cmd_file[PATH_MAX]; 1522 char *buf, *p; 1523 const char *base; 1524 int dirlen, ret; 1525 1526 base = strrchr(object, '/'); 1527 if (base) { 1528 base++; 1529 dirlen = base - object; 1530 } else { 1531 dirlen = 0; 1532 base = object; 1533 } 1534 1535 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1536 dirlen, object, base); 1537 if (ret >= sizeof(cmd_file)) { 1538 error("%s: too long path was truncated\n", cmd_file); 1539 return; 1540 } 1541 1542 buf = read_text_file(cmd_file); 1543 p = buf; 1544 1545 while ((p = strstr(p, "\n#SYMVER "))) { 1546 char *name; 1547 size_t namelen; 1548 unsigned int crc; 1549 struct symbol *sym; 1550 1551 name = p + strlen("\n#SYMVER "); 1552 1553 p = strchr(name, ' '); 1554 if (!p) 1555 break; 1556 1557 namelen = p - name; 1558 p++; 1559 1560 if (!isdigit(*p)) 1561 continue; /* skip this line */ 1562 1563 crc = strtoul(p, &p, 0); 1564 if (*p != '\n') 1565 continue; /* skip this line */ 1566 1567 name[namelen] = '\0'; 1568 1569 /* 1570 * sym_find_with_module() may return NULL here. 1571 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1572 * Since commit e1327a127703, genksyms calculates CRCs of all 1573 * symbols, including trimmed ones. Ignore orphan CRCs. 1574 */ 1575 sym = sym_find_with_module(name, mod); 1576 if (sym) 1577 sym_set_crc(sym, crc); 1578 } 1579 1580 free(buf); 1581 } 1582 1583 /* 1584 * The symbol versions (CRC) are recorded in the .*.cmd files. 1585 * Parse them to retrieve CRCs for the current module. 1586 */ 1587 static void mod_set_crcs(struct module *mod) 1588 { 1589 char objlist[PATH_MAX]; 1590 char *buf, *p, *obj; 1591 int ret; 1592 1593 if (mod->is_vmlinux) { 1594 strcpy(objlist, ".vmlinux.objs"); 1595 } else { 1596 /* objects for a module are listed in the *.mod file. */ 1597 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1598 if (ret >= sizeof(objlist)) { 1599 error("%s: too long path was truncated\n", objlist); 1600 return; 1601 } 1602 } 1603 1604 buf = read_text_file(objlist); 1605 p = buf; 1606 1607 while ((obj = strsep(&p, "\n")) && obj[0]) 1608 extract_crcs_for_object(obj, mod); 1609 1610 free(buf); 1611 } 1612 1613 static void read_symbols(const char *modname) 1614 { 1615 const char *symname; 1616 char *version; 1617 char *license; 1618 char *namespace; 1619 struct module *mod; 1620 struct elf_info info = { }; 1621 Elf_Sym *sym; 1622 1623 if (!parse_elf(&info, modname)) 1624 return; 1625 1626 if (!strends(modname, ".o")) { 1627 error("%s: filename must be suffixed with .o\n", modname); 1628 return; 1629 } 1630 1631 /* strip trailing .o */ 1632 mod = new_module(modname, strlen(modname) - strlen(".o")); 1633 1634 if (!mod->is_vmlinux) { 1635 license = get_modinfo(&info, "license"); 1636 if (!license) 1637 error("missing MODULE_LICENSE() in %s\n", modname); 1638 while (license) { 1639 if (!license_is_gpl_compatible(license)) { 1640 mod->is_gpl_compatible = false; 1641 break; 1642 } 1643 license = get_next_modinfo(&info, "license", license); 1644 } 1645 1646 namespace = get_modinfo(&info, "import_ns"); 1647 while (namespace) { 1648 add_namespace(&mod->imported_namespaces, namespace); 1649 namespace = get_next_modinfo(&info, "import_ns", 1650 namespace); 1651 } 1652 } 1653 1654 if (extra_warn && !get_modinfo(&info, "description")) 1655 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1656 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1657 symname = remove_dot(info.strtab + sym->st_name); 1658 1659 handle_symbol(mod, &info, sym, symname); 1660 handle_moddevtable(mod, &info, sym, symname); 1661 } 1662 1663 check_sec_ref(mod, &info); 1664 1665 if (!mod->is_vmlinux) { 1666 version = get_modinfo(&info, "version"); 1667 if (version || all_versions) 1668 get_src_version(mod->name, mod->srcversion, 1669 sizeof(mod->srcversion) - 1); 1670 } 1671 1672 parse_elf_finish(&info); 1673 1674 if (modversions) { 1675 /* 1676 * Our trick to get versioning for module struct etc. - it's 1677 * never passed as an argument to an exported function, so 1678 * the automatic versioning doesn't pick it up, but it's really 1679 * important anyhow. 1680 */ 1681 sym_add_unresolved("module_layout", mod, false); 1682 1683 mod_set_crcs(mod); 1684 } 1685 } 1686 1687 static void read_symbols_from_files(const char *filename) 1688 { 1689 FILE *in = stdin; 1690 char fname[PATH_MAX]; 1691 1692 in = fopen(filename, "r"); 1693 if (!in) 1694 fatal("Can't open filenames file %s: %m", filename); 1695 1696 while (fgets(fname, PATH_MAX, in) != NULL) { 1697 if (strends(fname, "\n")) 1698 fname[strlen(fname)-1] = '\0'; 1699 read_symbols(fname); 1700 } 1701 1702 fclose(in); 1703 } 1704 1705 #define SZ 500 1706 1707 /* We first write the generated file into memory using the 1708 * following helper, then compare to the file on disk and 1709 * only update the later if anything changed */ 1710 1711 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1712 const char *fmt, ...) 1713 { 1714 char tmp[SZ]; 1715 int len; 1716 va_list ap; 1717 1718 va_start(ap, fmt); 1719 len = vsnprintf(tmp, SZ, fmt, ap); 1720 buf_write(buf, tmp, len); 1721 va_end(ap); 1722 } 1723 1724 void buf_write(struct buffer *buf, const char *s, int len) 1725 { 1726 if (buf->size - buf->pos < len) { 1727 buf->size += len + SZ; 1728 buf->p = NOFAIL(realloc(buf->p, buf->size)); 1729 } 1730 strncpy(buf->p + buf->pos, s, len); 1731 buf->pos += len; 1732 } 1733 1734 static void check_exports(struct module *mod) 1735 { 1736 struct symbol *s, *exp; 1737 1738 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1739 const char *basename; 1740 exp = find_symbol(s->name); 1741 if (!exp) { 1742 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1743 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, 1744 "\"%s\" [%s.ko] undefined!\n", 1745 s->name, mod->name); 1746 continue; 1747 } 1748 if (exp->module == mod) { 1749 error("\"%s\" [%s.ko] was exported without definition\n", 1750 s->name, mod->name); 1751 continue; 1752 } 1753 1754 exp->used = true; 1755 s->module = exp->module; 1756 s->crc_valid = exp->crc_valid; 1757 s->crc = exp->crc; 1758 1759 basename = strrchr(mod->name, '/'); 1760 if (basename) 1761 basename++; 1762 else 1763 basename = mod->name; 1764 1765 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1766 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, 1767 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1768 basename, exp->name, exp->namespace); 1769 add_namespace(&mod->missing_namespaces, exp->namespace); 1770 } 1771 1772 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1773 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1774 basename, exp->name); 1775 } 1776 } 1777 1778 static void handle_white_list_exports(const char *white_list) 1779 { 1780 char *buf, *p, *name; 1781 1782 buf = read_text_file(white_list); 1783 p = buf; 1784 1785 while ((name = strsep(&p, "\n"))) { 1786 struct symbol *sym = find_symbol(name); 1787 1788 if (sym) 1789 sym->used = true; 1790 } 1791 1792 free(buf); 1793 } 1794 1795 static void check_modname_len(struct module *mod) 1796 { 1797 const char *mod_name; 1798 1799 mod_name = strrchr(mod->name, '/'); 1800 if (mod_name == NULL) 1801 mod_name = mod->name; 1802 else 1803 mod_name++; 1804 if (strlen(mod_name) >= MODULE_NAME_LEN) 1805 error("module name is too long [%s.ko]\n", mod->name); 1806 } 1807 1808 /** 1809 * Header for the generated file 1810 **/ 1811 static void add_header(struct buffer *b, struct module *mod) 1812 { 1813 buf_printf(b, "#include <linux/module.h>\n"); 1814 /* 1815 * Include build-salt.h after module.h in order to 1816 * inherit the definitions. 1817 */ 1818 buf_printf(b, "#define INCLUDE_VERMAGIC\n"); 1819 buf_printf(b, "#include <linux/build-salt.h>\n"); 1820 buf_printf(b, "#include <linux/elfnote-lto.h>\n"); 1821 buf_printf(b, "#include <linux/export-internal.h>\n"); 1822 buf_printf(b, "#include <linux/vermagic.h>\n"); 1823 buf_printf(b, "#include <linux/compiler.h>\n"); 1824 buf_printf(b, "\n"); 1825 buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n"); 1826 buf_printf(b, "#include <asm/orc_header.h>\n"); 1827 buf_printf(b, "ORC_HEADER;\n"); 1828 buf_printf(b, "#endif\n"); 1829 buf_printf(b, "\n"); 1830 buf_printf(b, "BUILD_SALT;\n"); 1831 buf_printf(b, "BUILD_LTO_INFO;\n"); 1832 buf_printf(b, "\n"); 1833 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1834 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1835 buf_printf(b, "\n"); 1836 buf_printf(b, "__visible struct module __this_module\n"); 1837 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1838 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1839 if (mod->has_init) 1840 buf_printf(b, "\t.init = init_module,\n"); 1841 if (mod->has_cleanup) 1842 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1843 "\t.exit = cleanup_module,\n" 1844 "#endif\n"); 1845 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1846 buf_printf(b, "};\n"); 1847 1848 if (!external_module) 1849 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1850 1851 buf_printf(b, 1852 "\n" 1853 "#ifdef CONFIG_MITIGATION_RETPOLINE\n" 1854 "MODULE_INFO(retpoline, \"Y\");\n" 1855 "#endif\n"); 1856 1857 if (strstarts(mod->name, "drivers/staging")) 1858 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1859 1860 if (strstarts(mod->name, "tools/testing")) 1861 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1862 } 1863 1864 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1865 { 1866 struct symbol *sym; 1867 1868 /* generate struct for exported symbols */ 1869 buf_printf(buf, "\n"); 1870 list_for_each_entry(sym, &mod->exported_symbols, list) { 1871 if (trim_unused_exports && !sym->used) 1872 continue; 1873 1874 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1875 sym->is_func ? "FUNC" : "DATA", sym->name, 1876 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1877 } 1878 1879 if (!modversions) 1880 return; 1881 1882 /* record CRCs for exported symbols */ 1883 buf_printf(buf, "\n"); 1884 list_for_each_entry(sym, &mod->exported_symbols, list) { 1885 if (trim_unused_exports && !sym->used) 1886 continue; 1887 1888 if (!sym->crc_valid) 1889 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1890 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1891 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1892 sym->name); 1893 1894 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1895 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1896 } 1897 } 1898 1899 /** 1900 * Record CRCs for unresolved symbols 1901 **/ 1902 static void add_versions(struct buffer *b, struct module *mod) 1903 { 1904 struct symbol *s; 1905 1906 if (!modversions) 1907 return; 1908 1909 buf_printf(b, "\n"); 1910 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1911 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1912 1913 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1914 if (!s->module) 1915 continue; 1916 if (!s->crc_valid) { 1917 warn("\"%s\" [%s.ko] has no CRC!\n", 1918 s->name, mod->name); 1919 continue; 1920 } 1921 if (strlen(s->name) >= MODULE_NAME_LEN) { 1922 error("too long symbol \"%s\" [%s.ko]\n", 1923 s->name, mod->name); 1924 break; 1925 } 1926 buf_printf(b, "\t{ %#8x, \"%s\" },\n", 1927 s->crc, s->name); 1928 } 1929 1930 buf_printf(b, "};\n"); 1931 } 1932 1933 static void add_depends(struct buffer *b, struct module *mod) 1934 { 1935 struct symbol *s; 1936 int first = 1; 1937 1938 /* Clear ->seen flag of modules that own symbols needed by this. */ 1939 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1940 if (s->module) 1941 s->module->seen = s->module->is_vmlinux; 1942 } 1943 1944 buf_printf(b, "\n"); 1945 buf_printf(b, "MODULE_INFO(depends, \""); 1946 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1947 const char *p; 1948 if (!s->module) 1949 continue; 1950 1951 if (s->module->seen) 1952 continue; 1953 1954 s->module->seen = true; 1955 p = strrchr(s->module->name, '/'); 1956 if (p) 1957 p++; 1958 else 1959 p = s->module->name; 1960 buf_printf(b, "%s%s", first ? "" : ",", p); 1961 first = 0; 1962 } 1963 buf_printf(b, "\");\n"); 1964 } 1965 1966 static void add_srcversion(struct buffer *b, struct module *mod) 1967 { 1968 if (mod->srcversion[0]) { 1969 buf_printf(b, "\n"); 1970 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1971 mod->srcversion); 1972 } 1973 } 1974 1975 static void write_buf(struct buffer *b, const char *fname) 1976 { 1977 FILE *file; 1978 1979 if (error_occurred) 1980 return; 1981 1982 file = fopen(fname, "w"); 1983 if (!file) { 1984 perror(fname); 1985 exit(1); 1986 } 1987 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1988 perror(fname); 1989 exit(1); 1990 } 1991 if (fclose(file) != 0) { 1992 perror(fname); 1993 exit(1); 1994 } 1995 } 1996 1997 static void write_if_changed(struct buffer *b, const char *fname) 1998 { 1999 char *tmp; 2000 FILE *file; 2001 struct stat st; 2002 2003 file = fopen(fname, "r"); 2004 if (!file) 2005 goto write; 2006 2007 if (fstat(fileno(file), &st) < 0) 2008 goto close_write; 2009 2010 if (st.st_size != b->pos) 2011 goto close_write; 2012 2013 tmp = NOFAIL(malloc(b->pos)); 2014 if (fread(tmp, 1, b->pos, file) != b->pos) 2015 goto free_write; 2016 2017 if (memcmp(tmp, b->p, b->pos) != 0) 2018 goto free_write; 2019 2020 free(tmp); 2021 fclose(file); 2022 return; 2023 2024 free_write: 2025 free(tmp); 2026 close_write: 2027 fclose(file); 2028 write: 2029 write_buf(b, fname); 2030 } 2031 2032 static void write_vmlinux_export_c_file(struct module *mod) 2033 { 2034 struct buffer buf = { }; 2035 2036 buf_printf(&buf, 2037 "#include <linux/export-internal.h>\n"); 2038 2039 add_exported_symbols(&buf, mod); 2040 write_if_changed(&buf, ".vmlinux.export.c"); 2041 free(buf.p); 2042 } 2043 2044 /* do sanity checks, and generate *.mod.c file */ 2045 static void write_mod_c_file(struct module *mod) 2046 { 2047 struct buffer buf = { }; 2048 char fname[PATH_MAX]; 2049 int ret; 2050 2051 add_header(&buf, mod); 2052 add_exported_symbols(&buf, mod); 2053 add_versions(&buf, mod); 2054 add_depends(&buf, mod); 2055 add_moddevtable(&buf, mod); 2056 add_srcversion(&buf, mod); 2057 2058 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2059 if (ret >= sizeof(fname)) { 2060 error("%s: too long path was truncated\n", fname); 2061 goto free; 2062 } 2063 2064 write_if_changed(&buf, fname); 2065 2066 free: 2067 free(buf.p); 2068 } 2069 2070 /* parse Module.symvers file. line format: 2071 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2072 **/ 2073 static void read_dump(const char *fname) 2074 { 2075 char *buf, *pos, *line; 2076 2077 buf = read_text_file(fname); 2078 if (!buf) 2079 /* No symbol versions, silently ignore */ 2080 return; 2081 2082 pos = buf; 2083 2084 while ((line = get_line(&pos))) { 2085 char *symname, *namespace, *modname, *d, *export; 2086 unsigned int crc; 2087 struct module *mod; 2088 struct symbol *s; 2089 bool gpl_only; 2090 2091 if (!(symname = strchr(line, '\t'))) 2092 goto fail; 2093 *symname++ = '\0'; 2094 if (!(modname = strchr(symname, '\t'))) 2095 goto fail; 2096 *modname++ = '\0'; 2097 if (!(export = strchr(modname, '\t'))) 2098 goto fail; 2099 *export++ = '\0'; 2100 if (!(namespace = strchr(export, '\t'))) 2101 goto fail; 2102 *namespace++ = '\0'; 2103 2104 crc = strtoul(line, &d, 16); 2105 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2106 goto fail; 2107 2108 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2109 gpl_only = true; 2110 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2111 gpl_only = false; 2112 } else { 2113 error("%s: unknown license %s. skip", symname, export); 2114 continue; 2115 } 2116 2117 mod = find_module(modname); 2118 if (!mod) { 2119 mod = new_module(modname, strlen(modname)); 2120 mod->from_dump = true; 2121 } 2122 s = sym_add_exported(symname, mod, gpl_only, namespace); 2123 sym_set_crc(s, crc); 2124 } 2125 free(buf); 2126 return; 2127 fail: 2128 free(buf); 2129 fatal("parse error in symbol dump file\n"); 2130 } 2131 2132 static void write_dump(const char *fname) 2133 { 2134 struct buffer buf = { }; 2135 struct module *mod; 2136 struct symbol *sym; 2137 2138 list_for_each_entry(mod, &modules, list) { 2139 if (mod->from_dump) 2140 continue; 2141 list_for_each_entry(sym, &mod->exported_symbols, list) { 2142 if (trim_unused_exports && !sym->used) 2143 continue; 2144 2145 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2146 sym->crc, sym->name, mod->name, 2147 sym->is_gpl_only ? "_GPL" : "", 2148 sym->namespace); 2149 } 2150 } 2151 write_buf(&buf, fname); 2152 free(buf.p); 2153 } 2154 2155 static void write_namespace_deps_files(const char *fname) 2156 { 2157 struct module *mod; 2158 struct namespace_list *ns; 2159 struct buffer ns_deps_buf = {}; 2160 2161 list_for_each_entry(mod, &modules, list) { 2162 2163 if (mod->from_dump || list_empty(&mod->missing_namespaces)) 2164 continue; 2165 2166 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2167 2168 list_for_each_entry(ns, &mod->missing_namespaces, list) 2169 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2170 2171 buf_printf(&ns_deps_buf, "\n"); 2172 } 2173 2174 write_if_changed(&ns_deps_buf, fname); 2175 free(ns_deps_buf.p); 2176 } 2177 2178 struct dump_list { 2179 struct list_head list; 2180 const char *file; 2181 }; 2182 2183 int main(int argc, char **argv) 2184 { 2185 struct module *mod; 2186 char *missing_namespace_deps = NULL; 2187 char *unused_exports_white_list = NULL; 2188 char *dump_write = NULL, *files_source = NULL; 2189 int opt; 2190 LIST_HEAD(dump_lists); 2191 struct dump_list *dl, *dl2; 2192 2193 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) { 2194 switch (opt) { 2195 case 'e': 2196 external_module = true; 2197 break; 2198 case 'i': 2199 dl = NOFAIL(malloc(sizeof(*dl))); 2200 dl->file = optarg; 2201 list_add_tail(&dl->list, &dump_lists); 2202 break; 2203 case 'M': 2204 module_enabled = true; 2205 break; 2206 case 'm': 2207 modversions = true; 2208 break; 2209 case 'n': 2210 ignore_missing_files = true; 2211 break; 2212 case 'o': 2213 dump_write = optarg; 2214 break; 2215 case 'a': 2216 all_versions = true; 2217 break; 2218 case 'T': 2219 files_source = optarg; 2220 break; 2221 case 't': 2222 trim_unused_exports = true; 2223 break; 2224 case 'u': 2225 unused_exports_white_list = optarg; 2226 break; 2227 case 'W': 2228 extra_warn = true; 2229 break; 2230 case 'w': 2231 warn_unresolved = true; 2232 break; 2233 case 'E': 2234 sec_mismatch_warn_only = false; 2235 break; 2236 case 'N': 2237 allow_missing_ns_imports = true; 2238 break; 2239 case 'd': 2240 missing_namespace_deps = optarg; 2241 break; 2242 default: 2243 exit(1); 2244 } 2245 } 2246 2247 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2248 read_dump(dl->file); 2249 list_del(&dl->list); 2250 free(dl); 2251 } 2252 2253 while (optind < argc) 2254 read_symbols(argv[optind++]); 2255 2256 if (files_source) 2257 read_symbols_from_files(files_source); 2258 2259 list_for_each_entry(mod, &modules, list) { 2260 if (mod->from_dump || mod->is_vmlinux) 2261 continue; 2262 2263 check_modname_len(mod); 2264 check_exports(mod); 2265 } 2266 2267 if (unused_exports_white_list) 2268 handle_white_list_exports(unused_exports_white_list); 2269 2270 list_for_each_entry(mod, &modules, list) { 2271 if (mod->from_dump) 2272 continue; 2273 2274 if (mod->is_vmlinux) 2275 write_vmlinux_export_c_file(mod); 2276 else 2277 write_mod_c_file(mod); 2278 } 2279 2280 if (missing_namespace_deps) 2281 write_namespace_deps_files(missing_namespace_deps); 2282 2283 if (dump_write) 2284 write_dump(dump_write); 2285 if (sec_mismatch_count && !sec_mismatch_warn_only) 2286 error("Section mismatches detected.\n" 2287 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2288 2289 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2290 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2291 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2292 2293 return error_occurred ? 1 : 0; 2294 } 2295