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 break; 74 case LOG_FATAL: 75 fprintf(stderr, "FATAL: "); 76 break; 77 default: /* invalid loglevel, ignore */ 78 break; 79 } 80 81 fprintf(stderr, "modpost: "); 82 83 va_start(arglist, fmt); 84 vfprintf(stderr, fmt, arglist); 85 va_end(arglist); 86 87 if (loglevel == LOG_FATAL) 88 exit(1); 89 if (loglevel == LOG_ERROR) 90 error_occurred = true; 91 } 92 93 void __attribute__((alias("modpost_log"))) 94 modpost_log_noret(enum loglevel loglevel, const char *fmt, ...); 95 96 static inline bool strends(const char *str, const char *postfix) 97 { 98 if (strlen(str) < strlen(postfix)) 99 return false; 100 101 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; 102 } 103 104 void *do_nofail(void *ptr, const char *expr) 105 { 106 if (!ptr) 107 fatal("Memory allocation failure: %s.\n", expr); 108 109 return ptr; 110 } 111 112 char *read_text_file(const char *filename) 113 { 114 struct stat st; 115 size_t nbytes; 116 int fd; 117 char *buf; 118 119 fd = open(filename, O_RDONLY); 120 if (fd < 0) { 121 perror(filename); 122 exit(1); 123 } 124 125 if (fstat(fd, &st) < 0) { 126 perror(filename); 127 exit(1); 128 } 129 130 buf = NOFAIL(malloc(st.st_size + 1)); 131 132 nbytes = st.st_size; 133 134 while (nbytes) { 135 ssize_t bytes_read; 136 137 bytes_read = read(fd, buf, nbytes); 138 if (bytes_read < 0) { 139 perror(filename); 140 exit(1); 141 } 142 143 nbytes -= bytes_read; 144 } 145 buf[st.st_size] = '\0'; 146 147 close(fd); 148 149 return buf; 150 } 151 152 char *get_line(char **stringp) 153 { 154 char *orig = *stringp, *next; 155 156 /* do not return the unwanted extra line at EOF */ 157 if (!orig || *orig == '\0') 158 return NULL; 159 160 /* don't use strsep here, it is not available everywhere */ 161 next = strchr(orig, '\n'); 162 if (next) 163 *next++ = '\0'; 164 165 *stringp = next; 166 167 return orig; 168 } 169 170 /* A list of all modules we processed */ 171 LIST_HEAD(modules); 172 173 static struct module *find_module(const char *modname) 174 { 175 struct module *mod; 176 177 list_for_each_entry(mod, &modules, list) { 178 if (strcmp(mod->name, modname) == 0) 179 return mod; 180 } 181 return NULL; 182 } 183 184 static struct module *new_module(const char *name, size_t namelen) 185 { 186 struct module *mod; 187 188 mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1)); 189 memset(mod, 0, sizeof(*mod)); 190 191 INIT_LIST_HEAD(&mod->exported_symbols); 192 INIT_LIST_HEAD(&mod->unresolved_symbols); 193 INIT_LIST_HEAD(&mod->missing_namespaces); 194 INIT_LIST_HEAD(&mod->imported_namespaces); 195 196 memcpy(mod->name, name, namelen); 197 mod->name[namelen] = '\0'; 198 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0); 199 200 /* 201 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE() 202 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue 203 * modpost will exit wiht error anyway. 204 */ 205 mod->is_gpl_compatible = true; 206 207 list_add_tail(&mod->list, &modules); 208 209 return mod; 210 } 211 212 /* A hash of all exported symbols, 213 * struct symbol is also used for lists of unresolved symbols */ 214 215 #define SYMBOL_HASH_SIZE 1024 216 217 struct symbol { 218 struct symbol *next; 219 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */ 220 struct module *module; 221 char *namespace; 222 unsigned int crc; 223 bool crc_valid; 224 bool weak; 225 bool is_func; 226 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ 227 bool used; /* there exists a user of this symbol */ 228 char name[]; 229 }; 230 231 static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 232 233 /* This is based on the hash algorithm from gdbm, via tdb */ 234 static inline unsigned int tdb_hash(const char *name) 235 { 236 unsigned value; /* Used to compute the hash value. */ 237 unsigned i; /* Used to cycle through random values. */ 238 239 /* Set the initial value from the key size. */ 240 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++) 241 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 242 243 return (1103515243 * value + 12345); 244 } 245 246 /** 247 * Allocate a new symbols for use in the hash of exported symbols or 248 * the list of unresolved symbols per module 249 **/ 250 static struct symbol *alloc_symbol(const char *name) 251 { 252 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 253 254 memset(s, 0, sizeof(*s)); 255 strcpy(s->name, name); 256 257 return s; 258 } 259 260 /* For the hash of exported symbols */ 261 static void hash_add_symbol(struct symbol *sym) 262 { 263 unsigned int hash; 264 265 hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE; 266 sym->next = symbolhash[hash]; 267 symbolhash[hash] = sym; 268 } 269 270 static void sym_add_unresolved(const char *name, struct module *mod, bool weak) 271 { 272 struct symbol *sym; 273 274 sym = alloc_symbol(name); 275 sym->weak = weak; 276 277 list_add_tail(&sym->list, &mod->unresolved_symbols); 278 } 279 280 static struct symbol *sym_find_with_module(const char *name, struct module *mod) 281 { 282 struct symbol *s; 283 284 /* For our purposes, .foo matches foo. PPC64 needs this. */ 285 if (name[0] == '.') 286 name++; 287 288 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) { 289 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) 290 return s; 291 } 292 return NULL; 293 } 294 295 static struct symbol *find_symbol(const char *name) 296 { 297 return sym_find_with_module(name, NULL); 298 } 299 300 struct namespace_list { 301 struct list_head list; 302 char namespace[]; 303 }; 304 305 static bool contains_namespace(struct list_head *head, const char *namespace) 306 { 307 struct namespace_list *list; 308 309 /* 310 * The default namespace is null string "", which is always implicitly 311 * contained. 312 */ 313 if (!namespace[0]) 314 return true; 315 316 list_for_each_entry(list, head, list) { 317 if (!strcmp(list->namespace, namespace)) 318 return true; 319 } 320 321 return false; 322 } 323 324 static void add_namespace(struct list_head *head, const char *namespace) 325 { 326 struct namespace_list *ns_entry; 327 328 if (!contains_namespace(head, namespace)) { 329 ns_entry = NOFAIL(malloc(sizeof(*ns_entry) + 330 strlen(namespace) + 1)); 331 strcpy(ns_entry->namespace, namespace); 332 list_add_tail(&ns_entry->list, head); 333 } 334 } 335 336 static void *sym_get_data_by_offset(const struct elf_info *info, 337 unsigned int secindex, unsigned long offset) 338 { 339 Elf_Shdr *sechdr = &info->sechdrs[secindex]; 340 341 return (void *)info->hdr + sechdr->sh_offset + offset; 342 } 343 344 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) 345 { 346 return sym_get_data_by_offset(info, get_secindex(info, sym), 347 sym->st_value); 348 } 349 350 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) 351 { 352 return sym_get_data_by_offset(info, info->secindex_strings, 353 sechdr->sh_name); 354 } 355 356 static const char *sec_name(const struct elf_info *info, unsigned int secindex) 357 { 358 /* 359 * If sym->st_shndx is a special section index, there is no 360 * corresponding section header. 361 * Return "" if the index is out of range of info->sechdrs[] array. 362 */ 363 if (secindex >= info->num_sections) 364 return ""; 365 366 return sech_name(info, &info->sechdrs[secindex]); 367 } 368 369 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) 370 371 static struct symbol *sym_add_exported(const char *name, struct module *mod, 372 bool gpl_only, const char *namespace) 373 { 374 struct symbol *s = find_symbol(name); 375 376 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { 377 error("%s: '%s' exported twice. Previous export was in %s%s\n", 378 mod->name, name, s->module->name, 379 s->module->is_vmlinux ? "" : ".ko"); 380 } 381 382 s = alloc_symbol(name); 383 s->module = mod; 384 s->is_gpl_only = gpl_only; 385 s->namespace = NOFAIL(strdup(namespace)); 386 list_add_tail(&s->list, &mod->exported_symbols); 387 hash_add_symbol(s); 388 389 return s; 390 } 391 392 static void sym_set_crc(struct symbol *sym, unsigned int crc) 393 { 394 sym->crc = crc; 395 sym->crc_valid = true; 396 } 397 398 static void *grab_file(const char *filename, size_t *size) 399 { 400 struct stat st; 401 void *map = MAP_FAILED; 402 int fd; 403 404 fd = open(filename, O_RDONLY); 405 if (fd < 0) 406 return NULL; 407 if (fstat(fd, &st)) 408 goto failed; 409 410 *size = st.st_size; 411 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 412 413 failed: 414 close(fd); 415 if (map == MAP_FAILED) 416 return NULL; 417 return map; 418 } 419 420 static void release_file(void *file, size_t size) 421 { 422 munmap(file, size); 423 } 424 425 static int parse_elf(struct elf_info *info, const char *filename) 426 { 427 unsigned int i; 428 Elf_Ehdr *hdr; 429 Elf_Shdr *sechdrs; 430 Elf_Sym *sym; 431 const char *secstrings; 432 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 433 434 hdr = grab_file(filename, &info->size); 435 if (!hdr) { 436 if (ignore_missing_files) { 437 fprintf(stderr, "%s: %s (ignored)\n", filename, 438 strerror(errno)); 439 return 0; 440 } 441 perror(filename); 442 exit(1); 443 } 444 info->hdr = hdr; 445 if (info->size < sizeof(*hdr)) { 446 /* file too small, assume this is an empty .o file */ 447 return 0; 448 } 449 /* Is this a valid ELF file? */ 450 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 451 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 452 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 453 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 454 /* Not an ELF file - silently ignore it */ 455 return 0; 456 } 457 /* Fix endianness in ELF header */ 458 hdr->e_type = TO_NATIVE(hdr->e_type); 459 hdr->e_machine = TO_NATIVE(hdr->e_machine); 460 hdr->e_version = TO_NATIVE(hdr->e_version); 461 hdr->e_entry = TO_NATIVE(hdr->e_entry); 462 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 463 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 464 hdr->e_flags = TO_NATIVE(hdr->e_flags); 465 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 466 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 467 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 468 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 469 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 470 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 471 sechdrs = (void *)hdr + hdr->e_shoff; 472 info->sechdrs = sechdrs; 473 474 /* modpost only works for relocatable objects */ 475 if (hdr->e_type != ET_REL) 476 fatal("%s: not relocatable object.", filename); 477 478 /* Check if file offset is correct */ 479 if (hdr->e_shoff > info->size) { 480 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", 481 (unsigned long)hdr->e_shoff, filename, info->size); 482 return 0; 483 } 484 485 if (hdr->e_shnum == SHN_UNDEF) { 486 /* 487 * There are more than 64k sections, 488 * read count from .sh_size. 489 */ 490 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 491 } 492 else { 493 info->num_sections = hdr->e_shnum; 494 } 495 if (hdr->e_shstrndx == SHN_XINDEX) { 496 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 497 } 498 else { 499 info->secindex_strings = hdr->e_shstrndx; 500 } 501 502 /* Fix endianness in section headers */ 503 for (i = 0; i < info->num_sections; i++) { 504 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 505 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 506 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 507 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 508 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 509 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 510 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 511 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 512 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 513 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 514 } 515 /* Find symbol table. */ 516 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 517 for (i = 1; i < info->num_sections; i++) { 518 const char *secname; 519 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 520 521 if (!nobits && sechdrs[i].sh_offset > info->size) { 522 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n", 523 filename, (unsigned long)sechdrs[i].sh_offset, 524 sizeof(*hdr)); 525 return 0; 526 } 527 secname = secstrings + sechdrs[i].sh_name; 528 if (strcmp(secname, ".modinfo") == 0) { 529 if (nobits) 530 fatal("%s has NOBITS .modinfo\n", filename); 531 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 532 info->modinfo_len = sechdrs[i].sh_size; 533 } else if (!strcmp(secname, ".export_symbol")) { 534 info->export_symbol_secndx = i; 535 } 536 537 if (sechdrs[i].sh_type == SHT_SYMTAB) { 538 unsigned int sh_link_idx; 539 symtab_idx = i; 540 info->symtab_start = (void *)hdr + 541 sechdrs[i].sh_offset; 542 info->symtab_stop = (void *)hdr + 543 sechdrs[i].sh_offset + sechdrs[i].sh_size; 544 sh_link_idx = sechdrs[i].sh_link; 545 info->strtab = (void *)hdr + 546 sechdrs[sh_link_idx].sh_offset; 547 } 548 549 /* 32bit section no. table? ("more than 64k sections") */ 550 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 551 symtab_shndx_idx = i; 552 info->symtab_shndx_start = (void *)hdr + 553 sechdrs[i].sh_offset; 554 info->symtab_shndx_stop = (void *)hdr + 555 sechdrs[i].sh_offset + sechdrs[i].sh_size; 556 } 557 } 558 if (!info->symtab_start) 559 fatal("%s has no symtab?\n", filename); 560 561 /* Fix endianness in symbols */ 562 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 563 sym->st_shndx = TO_NATIVE(sym->st_shndx); 564 sym->st_name = TO_NATIVE(sym->st_name); 565 sym->st_value = TO_NATIVE(sym->st_value); 566 sym->st_size = TO_NATIVE(sym->st_size); 567 } 568 569 if (symtab_shndx_idx != ~0U) { 570 Elf32_Word *p; 571 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 572 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 573 filename, sechdrs[symtab_shndx_idx].sh_link, 574 symtab_idx); 575 /* Fix endianness */ 576 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 577 p++) 578 *p = TO_NATIVE(*p); 579 } 580 581 symsearch_init(info); 582 583 return 1; 584 } 585 586 static void parse_elf_finish(struct elf_info *info) 587 { 588 symsearch_finish(info); 589 release_file(info->hdr, info->size); 590 } 591 592 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 593 { 594 /* ignore __this_module, it will be resolved shortly */ 595 if (strcmp(symname, "__this_module") == 0) 596 return 1; 597 /* ignore global offset table */ 598 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 599 return 1; 600 if (info->hdr->e_machine == EM_PPC) 601 /* Special register function linked on all modules during final link of .ko */ 602 if (strstarts(symname, "_restgpr_") || 603 strstarts(symname, "_savegpr_") || 604 strstarts(symname, "_rest32gpr_") || 605 strstarts(symname, "_save32gpr_") || 606 strstarts(symname, "_restvr_") || 607 strstarts(symname, "_savevr_")) 608 return 1; 609 if (info->hdr->e_machine == EM_PPC64) 610 /* Special register function linked on all modules during final link of .ko */ 611 if (strstarts(symname, "_restgpr0_") || 612 strstarts(symname, "_savegpr0_") || 613 strstarts(symname, "_restvr_") || 614 strstarts(symname, "_savevr_") || 615 strcmp(symname, ".TOC.") == 0) 616 return 1; 617 618 if (info->hdr->e_machine == EM_S390) 619 /* Expoline thunks are linked on all kernel modules during final link of .ko */ 620 if (strstarts(symname, "__s390_indirect_jump_r")) 621 return 1; 622 /* Do not ignore this symbol */ 623 return 0; 624 } 625 626 static void handle_symbol(struct module *mod, struct elf_info *info, 627 const Elf_Sym *sym, const char *symname) 628 { 629 switch (sym->st_shndx) { 630 case SHN_COMMON: 631 if (strstarts(symname, "__gnu_lto_")) { 632 /* Should warn here, but modpost runs before the linker */ 633 } else 634 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 635 break; 636 case SHN_UNDEF: 637 /* undefined symbol */ 638 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 639 ELF_ST_BIND(sym->st_info) != STB_WEAK) 640 break; 641 if (ignore_undef_symbol(info, symname)) 642 break; 643 if (info->hdr->e_machine == EM_SPARC || 644 info->hdr->e_machine == EM_SPARCV9) { 645 /* Ignore register directives. */ 646 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 647 break; 648 if (symname[0] == '.') { 649 char *munged = NOFAIL(strdup(symname)); 650 munged[0] = '_'; 651 munged[1] = toupper(munged[1]); 652 symname = munged; 653 } 654 } 655 656 sym_add_unresolved(symname, mod, 657 ELF_ST_BIND(sym->st_info) == STB_WEAK); 658 break; 659 default: 660 if (strcmp(symname, "init_module") == 0) 661 mod->has_init = true; 662 if (strcmp(symname, "cleanup_module") == 0) 663 mod->has_cleanup = true; 664 break; 665 } 666 } 667 668 /** 669 * Parse tag=value strings from .modinfo section 670 **/ 671 static char *next_string(char *string, unsigned long *secsize) 672 { 673 /* Skip non-zero chars */ 674 while (string[0]) { 675 string++; 676 if ((*secsize)-- <= 1) 677 return NULL; 678 } 679 680 /* Skip any zero padding. */ 681 while (!string[0]) { 682 string++; 683 if ((*secsize)-- <= 1) 684 return NULL; 685 } 686 return string; 687 } 688 689 static char *get_next_modinfo(struct elf_info *info, const char *tag, 690 char *prev) 691 { 692 char *p; 693 unsigned int taglen = strlen(tag); 694 char *modinfo = info->modinfo; 695 unsigned long size = info->modinfo_len; 696 697 if (prev) { 698 size -= prev - modinfo; 699 modinfo = next_string(prev, &size); 700 } 701 702 for (p = modinfo; p; p = next_string(p, &size)) { 703 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 704 return p + taglen + 1; 705 } 706 return NULL; 707 } 708 709 static char *get_modinfo(struct elf_info *info, const char *tag) 710 711 { 712 return get_next_modinfo(info, tag, NULL); 713 } 714 715 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 716 { 717 if (sym) 718 return elf->strtab + sym->st_name; 719 else 720 return "(unknown)"; 721 } 722 723 /* 724 * Check whether the 'string' argument matches one of the 'patterns', 725 * an array of shell wildcard patterns (glob). 726 * 727 * Return true is there is a match. 728 */ 729 static bool match(const char *string, const char *const patterns[]) 730 { 731 const char *pattern; 732 733 while ((pattern = *patterns++)) { 734 if (!fnmatch(pattern, string, 0)) 735 return true; 736 } 737 738 return false; 739 } 740 741 /* useful to pass patterns to match() directly */ 742 #define PATTERNS(...) \ 743 ({ \ 744 static const char *const patterns[] = {__VA_ARGS__, NULL}; \ 745 patterns; \ 746 }) 747 748 /* sections that we do not want to do full section mismatch check on */ 749 static const char *const section_white_list[] = 750 { 751 ".comment*", 752 ".debug*", 753 ".zdebug*", /* Compressed debug sections. */ 754 ".GCC.command.line", /* record-gcc-switches */ 755 ".mdebug*", /* alpha, score, mips etc. */ 756 ".pdr", /* alpha, score, mips etc. */ 757 ".stab*", 758 ".note*", 759 ".got*", 760 ".toc*", 761 ".xt.prop", /* xtensa */ 762 ".xt.lit", /* xtensa */ 763 ".arcextmap*", /* arc */ 764 ".gnu.linkonce.arcext*", /* arc : modules */ 765 ".cmem*", /* EZchip */ 766 ".fmt_slot*", /* EZchip */ 767 ".gnu.lto*", 768 ".discard.*", 769 ".llvm.call-graph-profile", /* call graph */ 770 NULL 771 }; 772 773 /* 774 * This is used to find sections missing the SHF_ALLOC flag. 775 * The cause of this is often a section specified in assembler 776 * without "ax" / "aw". 777 */ 778 static void check_section(const char *modname, struct elf_info *elf, 779 Elf_Shdr *sechdr) 780 { 781 const char *sec = sech_name(elf, sechdr); 782 783 if (sechdr->sh_type == SHT_PROGBITS && 784 !(sechdr->sh_flags & SHF_ALLOC) && 785 !match(sec, section_white_list)) { 786 warn("%s (%s): unexpected non-allocatable section.\n" 787 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 788 "Note that for example <linux/init.h> contains\n" 789 "section definitions for use in .S files.\n\n", 790 modname, sec); 791 } 792 } 793 794 795 796 #define ALL_INIT_DATA_SECTIONS \ 797 ".init.setup", ".init.rodata", ".meminit.rodata", \ 798 ".init.data", ".meminit.data" 799 800 #define ALL_PCI_INIT_SECTIONS \ 801 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 802 ".pci_fixup_enable", ".pci_fixup_resume", \ 803 ".pci_fixup_resume_early", ".pci_fixup_suspend" 804 805 #define ALL_XXXINIT_SECTIONS ".meminit.*" 806 807 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 808 #define ALL_EXIT_SECTIONS ".exit.*" 809 810 #define DATA_SECTIONS ".data", ".data.rel" 811 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ 812 ".kprobes.text", ".cpuidle.text", ".noinstr.text" 813 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ 814 ".fixup", ".entry.text", ".exception.text", \ 815 ".coldtext", ".softirqentry.text" 816 817 #define INIT_SECTIONS ".init.*" 818 819 #define ALL_TEXT_SECTIONS ".init.text", ".meminit.text", ".exit.text", \ 820 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 821 822 enum mismatch { 823 TEXTDATA_TO_ANY_INIT_EXIT, 824 XXXINIT_TO_SOME_INIT, 825 ANY_INIT_TO_ANY_EXIT, 826 ANY_EXIT_TO_ANY_INIT, 827 EXTABLE_TO_NON_TEXT, 828 }; 829 830 /** 831 * Describe how to match sections on different criteria: 832 * 833 * @fromsec: Array of sections to be matched. 834 * 835 * @bad_tosec: Relocations applied to a section in @fromsec to a section in 836 * this array is forbidden (black-list). Can be empty. 837 * 838 * @good_tosec: Relocations applied to a section in @fromsec must be 839 * targeting sections in this array (white-list). Can be empty. 840 * 841 * @mismatch: Type of mismatch. 842 */ 843 struct sectioncheck { 844 const char *fromsec[20]; 845 const char *bad_tosec[20]; 846 const char *good_tosec[20]; 847 enum mismatch mismatch; 848 }; 849 850 static const struct sectioncheck sectioncheck[] = { 851 /* Do not reference init/exit code/data from 852 * normal code and data 853 */ 854 { 855 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 856 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }, 857 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT, 858 }, 859 /* Do not reference init code/data from meminit code/data */ 860 { 861 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 862 .bad_tosec = { INIT_SECTIONS, NULL }, 863 .mismatch = XXXINIT_TO_SOME_INIT, 864 }, 865 /* Do not use exit code/data from init code */ 866 { 867 .fromsec = { ALL_INIT_SECTIONS, NULL }, 868 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 869 .mismatch = ANY_INIT_TO_ANY_EXIT, 870 }, 871 /* Do not use init code/data from exit code */ 872 { 873 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 874 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 875 .mismatch = ANY_EXIT_TO_ANY_INIT, 876 }, 877 { 878 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 879 .bad_tosec = { INIT_SECTIONS, NULL }, 880 .mismatch = ANY_INIT_TO_ANY_EXIT, 881 }, 882 { 883 .fromsec = { "__ex_table", NULL }, 884 /* If you're adding any new black-listed sections in here, consider 885 * adding a special 'printer' for them in scripts/check_extable. 886 */ 887 .bad_tosec = { ".altinstr_replacement", NULL }, 888 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 889 .mismatch = EXTABLE_TO_NON_TEXT, 890 } 891 }; 892 893 static const struct sectioncheck *section_mismatch( 894 const char *fromsec, const char *tosec) 895 { 896 int i; 897 898 /* 899 * The target section could be the SHT_NUL section when we're 900 * handling relocations to un-resolved symbols, trying to match it 901 * doesn't make much sense and causes build failures on parisc 902 * architectures. 903 */ 904 if (*tosec == '\0') 905 return NULL; 906 907 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 908 const struct sectioncheck *check = §ioncheck[i]; 909 910 if (match(fromsec, check->fromsec)) { 911 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 912 return check; 913 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 914 return check; 915 } 916 } 917 return NULL; 918 } 919 920 /** 921 * Whitelist to allow certain references to pass with no warning. 922 * 923 * Pattern 1: 924 * If a module parameter is declared __initdata and permissions=0 925 * then this is legal despite the warning generated. 926 * We cannot see value of permissions here, so just ignore 927 * this pattern. 928 * The pattern is identified by: 929 * tosec = .init.data 930 * fromsec = .data* 931 * atsym =__param* 932 * 933 * Pattern 1a: 934 * module_param_call() ops can refer to __init set function if permissions=0 935 * The pattern is identified by: 936 * tosec = .init.text 937 * fromsec = .data* 938 * atsym = __param_ops_* 939 * 940 * Pattern 3: 941 * Whitelist all references from .head.text to any init section 942 * 943 * Pattern 4: 944 * Some symbols belong to init section but still it is ok to reference 945 * these from non-init sections as these symbols don't have any memory 946 * allocated for them and symbol address and value are same. So even 947 * if init section is freed, its ok to reference those symbols. 948 * For ex. symbols marking the init section boundaries. 949 * This pattern is identified by 950 * refsymname = __init_begin, _sinittext, _einittext 951 * 952 * Pattern 5: 953 * GCC may optimize static inlines when fed constant arg(s) resulting 954 * in functions like cpumask_empty() -- generating an associated symbol 955 * cpumask_empty.constprop.3 that appears in the audit. If the const that 956 * is passed in comes from __init, like say nmi_ipi_mask, we get a 957 * meaningless section warning. May need to add isra symbols too... 958 * This pattern is identified by 959 * tosec = init section 960 * fromsec = text section 961 * refsymname = *.constprop.* 962 * 963 **/ 964 static int secref_whitelist(const char *fromsec, const char *fromsym, 965 const char *tosec, const char *tosym) 966 { 967 /* Check for pattern 1 */ 968 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 969 match(fromsec, PATTERNS(DATA_SECTIONS)) && 970 strstarts(fromsym, "__param")) 971 return 0; 972 973 /* Check for pattern 1a */ 974 if (strcmp(tosec, ".init.text") == 0 && 975 match(fromsec, PATTERNS(DATA_SECTIONS)) && 976 strstarts(fromsym, "__param_ops_")) 977 return 0; 978 979 /* symbols in data sections that may refer to any init/exit sections */ 980 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 981 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 982 match(fromsym, PATTERNS("*_ops", "*_probe", "*_console"))) 983 return 0; 984 985 /* 986 * symbols in data sections must not refer to .exit.*, but there are 987 * quite a few offenders, so hide these unless for W=1 builds until 988 * these are fixed. 989 */ 990 if (!extra_warn && 991 match(fromsec, PATTERNS(DATA_SECTIONS)) && 992 match(tosec, PATTERNS(ALL_EXIT_SECTIONS)) && 993 match(fromsym, PATTERNS("*driver"))) 994 return 0; 995 996 /* Check for pattern 3 */ 997 if (strstarts(fromsec, ".head.text") && 998 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 999 return 0; 1000 1001 /* Check for pattern 4 */ 1002 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 1003 return 0; 1004 1005 /* Check for pattern 5 */ 1006 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 1007 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 1008 match(fromsym, PATTERNS("*.constprop.*"))) 1009 return 0; 1010 1011 return 1; 1012 } 1013 1014 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 1015 unsigned int secndx) 1016 { 1017 return symsearch_find_nearest(elf, addr, secndx, false, ~0); 1018 } 1019 1020 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 1021 { 1022 /* If the supplied symbol has a valid name, return it */ 1023 if (is_valid_name(elf, sym)) 1024 return sym; 1025 1026 /* 1027 * Strive to find a better symbol name, but the resulting name may not 1028 * match the symbol referenced in the original code. 1029 */ 1030 return symsearch_find_nearest(elf, addr, get_secindex(elf, sym), 1031 true, 20); 1032 } 1033 1034 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1035 { 1036 if (secndx >= elf->num_sections) 1037 return false; 1038 1039 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1040 } 1041 1042 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1043 const struct sectioncheck* const mismatch, 1044 Elf_Sym *tsym, 1045 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1046 const char *tosec, Elf_Addr taddr) 1047 { 1048 Elf_Sym *from; 1049 const char *tosym; 1050 const char *fromsym; 1051 1052 from = find_fromsym(elf, faddr, fsecndx); 1053 fromsym = sym_name(elf, from); 1054 1055 tsym = find_tosym(elf, taddr, tsym); 1056 tosym = sym_name(elf, tsym); 1057 1058 /* check whitelist - we may ignore it */ 1059 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1060 return; 1061 1062 sec_mismatch_count++; 1063 1064 warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n", 1065 modname, fromsym, (unsigned int)(faddr - from->st_value), fromsec, tosym, tosec); 1066 1067 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1068 if (match(tosec, mismatch->bad_tosec)) 1069 fatal("The relocation at %s+0x%lx references\n" 1070 "section \"%s\" which is black-listed.\n" 1071 "Something is seriously wrong and should be fixed.\n" 1072 "You might get more information about where this is\n" 1073 "coming from by using scripts/check_extable.sh %s\n", 1074 fromsec, (long)faddr, tosec, modname); 1075 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1076 warn("The relocation at %s+0x%lx references\n" 1077 "section \"%s\" which is not in the list of\n" 1078 "authorized sections. If you're adding a new section\n" 1079 "and/or if this reference is valid, add \"%s\" to the\n" 1080 "list of authorized sections to jump to on fault.\n" 1081 "This can be achieved by adding \"%s\" to\n" 1082 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1083 fromsec, (long)faddr, tosec, tosec, tosec); 1084 else 1085 error("%s+0x%lx references non-executable section '%s'\n", 1086 fromsec, (long)faddr, tosec); 1087 } 1088 } 1089 1090 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1091 Elf_Addr faddr, const char *secname, 1092 Elf_Sym *sym) 1093 { 1094 static const char *prefix = "__export_symbol_"; 1095 const char *label_name, *name, *data; 1096 Elf_Sym *label; 1097 struct symbol *s; 1098 bool is_gpl; 1099 1100 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1101 label_name = sym_name(elf, label); 1102 1103 if (!strstarts(label_name, prefix)) { 1104 error("%s: .export_symbol section contains strange symbol '%s'\n", 1105 mod->name, label_name); 1106 return; 1107 } 1108 1109 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1110 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1111 error("%s: local symbol '%s' was exported\n", mod->name, 1112 label_name + strlen(prefix)); 1113 return; 1114 } 1115 1116 name = sym_name(elf, sym); 1117 if (strcmp(label_name + strlen(prefix), name)) { 1118 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1119 mod->name, name); 1120 return; 1121 } 1122 1123 data = sym_get_data(elf, label); /* license */ 1124 if (!strcmp(data, "GPL")) { 1125 is_gpl = true; 1126 } else if (!strcmp(data, "")) { 1127 is_gpl = false; 1128 } else { 1129 error("%s: unknown license '%s' was specified for '%s'\n", 1130 mod->name, data, name); 1131 return; 1132 } 1133 1134 data += strlen(data) + 1; /* namespace */ 1135 s = sym_add_exported(name, mod, is_gpl, data); 1136 1137 /* 1138 * We need to be aware whether we are exporting a function or 1139 * a data on some architectures. 1140 */ 1141 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1142 1143 /* 1144 * For parisc64, symbols prefixed $$ from the library have the symbol type 1145 * STT_LOPROC. They should be handled as functions too. 1146 */ 1147 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1148 elf->hdr->e_machine == EM_PARISC && 1149 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1150 s->is_func = true; 1151 1152 if (match(secname, PATTERNS(ALL_INIT_SECTIONS))) 1153 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1154 mod->name, name); 1155 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS))) 1156 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1157 mod->name, name); 1158 } 1159 1160 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1161 Elf_Sym *sym, 1162 unsigned int fsecndx, const char *fromsec, 1163 Elf_Addr faddr, Elf_Addr taddr) 1164 { 1165 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1166 const struct sectioncheck *mismatch; 1167 1168 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1169 check_export_symbol(mod, elf, faddr, tosec, sym); 1170 return; 1171 } 1172 1173 mismatch = section_mismatch(fromsec, tosec); 1174 if (!mismatch) 1175 return; 1176 1177 default_mismatch_handler(mod->name, elf, mismatch, sym, 1178 fsecndx, fromsec, faddr, 1179 tosec, taddr); 1180 } 1181 1182 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1183 { 1184 switch (r_type) { 1185 case R_386_32: 1186 return TO_NATIVE(*location); 1187 case R_386_PC32: 1188 return TO_NATIVE(*location) + 4; 1189 } 1190 1191 return (Elf_Addr)(-1); 1192 } 1193 1194 #ifndef R_ARM_CALL 1195 #define R_ARM_CALL 28 1196 #endif 1197 #ifndef R_ARM_JUMP24 1198 #define R_ARM_JUMP24 29 1199 #endif 1200 1201 #ifndef R_ARM_THM_CALL 1202 #define R_ARM_THM_CALL 10 1203 #endif 1204 #ifndef R_ARM_THM_JUMP24 1205 #define R_ARM_THM_JUMP24 30 1206 #endif 1207 1208 #ifndef R_ARM_MOVW_ABS_NC 1209 #define R_ARM_MOVW_ABS_NC 43 1210 #endif 1211 1212 #ifndef R_ARM_MOVT_ABS 1213 #define R_ARM_MOVT_ABS 44 1214 #endif 1215 1216 #ifndef R_ARM_THM_MOVW_ABS_NC 1217 #define R_ARM_THM_MOVW_ABS_NC 47 1218 #endif 1219 1220 #ifndef R_ARM_THM_MOVT_ABS 1221 #define R_ARM_THM_MOVT_ABS 48 1222 #endif 1223 1224 #ifndef R_ARM_THM_JUMP19 1225 #define R_ARM_THM_JUMP19 51 1226 #endif 1227 1228 static int32_t sign_extend32(int32_t value, int index) 1229 { 1230 uint8_t shift = 31 - index; 1231 1232 return (int32_t)(value << shift) >> shift; 1233 } 1234 1235 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1236 { 1237 uint32_t inst, upper, lower, sign, j1, j2; 1238 int32_t offset; 1239 1240 switch (r_type) { 1241 case R_ARM_ABS32: 1242 case R_ARM_REL32: 1243 inst = TO_NATIVE(*(uint32_t *)loc); 1244 return inst + sym->st_value; 1245 case R_ARM_MOVW_ABS_NC: 1246 case R_ARM_MOVT_ABS: 1247 inst = TO_NATIVE(*(uint32_t *)loc); 1248 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1249 15); 1250 return offset + sym->st_value; 1251 case R_ARM_PC24: 1252 case R_ARM_CALL: 1253 case R_ARM_JUMP24: 1254 inst = TO_NATIVE(*(uint32_t *)loc); 1255 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1256 return offset + sym->st_value + 8; 1257 case R_ARM_THM_MOVW_ABS_NC: 1258 case R_ARM_THM_MOVT_ABS: 1259 upper = TO_NATIVE(*(uint16_t *)loc); 1260 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1261 offset = sign_extend32(((upper & 0x000f) << 12) | 1262 ((upper & 0x0400) << 1) | 1263 ((lower & 0x7000) >> 4) | 1264 (lower & 0x00ff), 1265 15); 1266 return offset + sym->st_value; 1267 case R_ARM_THM_JUMP19: 1268 /* 1269 * Encoding T3: 1270 * S = upper[10] 1271 * imm6 = upper[5:0] 1272 * J1 = lower[13] 1273 * J2 = lower[11] 1274 * imm11 = lower[10:0] 1275 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1276 */ 1277 upper = TO_NATIVE(*(uint16_t *)loc); 1278 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1279 1280 sign = (upper >> 10) & 1; 1281 j1 = (lower >> 13) & 1; 1282 j2 = (lower >> 11) & 1; 1283 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1284 ((upper & 0x03f) << 12) | 1285 ((lower & 0x07ff) << 1), 1286 20); 1287 return offset + sym->st_value + 4; 1288 case R_ARM_THM_CALL: 1289 case R_ARM_THM_JUMP24: 1290 /* 1291 * Encoding T4: 1292 * S = upper[10] 1293 * imm10 = upper[9:0] 1294 * J1 = lower[13] 1295 * J2 = lower[11] 1296 * imm11 = lower[10:0] 1297 * I1 = NOT(J1 XOR S) 1298 * I2 = NOT(J2 XOR S) 1299 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1300 */ 1301 upper = TO_NATIVE(*(uint16_t *)loc); 1302 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1303 1304 sign = (upper >> 10) & 1; 1305 j1 = (lower >> 13) & 1; 1306 j2 = (lower >> 11) & 1; 1307 offset = sign_extend32((sign << 24) | 1308 ((~(j1 ^ sign) & 1) << 23) | 1309 ((~(j2 ^ sign) & 1) << 22) | 1310 ((upper & 0x03ff) << 12) | 1311 ((lower & 0x07ff) << 1), 1312 24); 1313 return offset + sym->st_value + 4; 1314 } 1315 1316 return (Elf_Addr)(-1); 1317 } 1318 1319 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1320 { 1321 uint32_t inst; 1322 1323 inst = TO_NATIVE(*location); 1324 switch (r_type) { 1325 case R_MIPS_LO16: 1326 return inst & 0xffff; 1327 case R_MIPS_26: 1328 return (inst & 0x03ffffff) << 2; 1329 case R_MIPS_32: 1330 return inst; 1331 } 1332 return (Elf_Addr)(-1); 1333 } 1334 1335 #ifndef EM_RISCV 1336 #define EM_RISCV 243 1337 #endif 1338 1339 #ifndef R_RISCV_SUB32 1340 #define R_RISCV_SUB32 39 1341 #endif 1342 1343 #ifndef EM_LOONGARCH 1344 #define EM_LOONGARCH 258 1345 #endif 1346 1347 #ifndef R_LARCH_SUB32 1348 #define R_LARCH_SUB32 55 1349 #endif 1350 1351 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1352 unsigned int *r_type, unsigned int *r_sym) 1353 { 1354 typedef struct { 1355 Elf64_Word r_sym; /* Symbol index */ 1356 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1357 unsigned char r_type3; /* 3rd relocation type */ 1358 unsigned char r_type2; /* 2nd relocation type */ 1359 unsigned char r_type; /* 1st relocation type */ 1360 } Elf64_Mips_R_Info; 1361 1362 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1363 1364 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1365 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1366 1367 *r_type = mips64_r_info->r_type; 1368 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1369 return; 1370 } 1371 1372 if (is_64bit) 1373 r_info = TO_NATIVE((Elf64_Xword)r_info); 1374 else 1375 r_info = TO_NATIVE((Elf32_Word)r_info); 1376 1377 *r_type = ELF_R_TYPE(r_info); 1378 *r_sym = ELF_R_SYM(r_info); 1379 } 1380 1381 static void section_rela(struct module *mod, struct elf_info *elf, 1382 unsigned int fsecndx, const char *fromsec, 1383 const Elf_Rela *start, const Elf_Rela *stop) 1384 { 1385 const Elf_Rela *rela; 1386 1387 for (rela = start; rela < stop; rela++) { 1388 Elf_Sym *tsym; 1389 Elf_Addr taddr, r_offset; 1390 unsigned int r_type, r_sym; 1391 1392 r_offset = TO_NATIVE(rela->r_offset); 1393 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1394 1395 tsym = elf->symtab_start + r_sym; 1396 taddr = tsym->st_value + TO_NATIVE(rela->r_addend); 1397 1398 switch (elf->hdr->e_machine) { 1399 case EM_RISCV: 1400 if (!strcmp("__ex_table", fromsec) && 1401 r_type == R_RISCV_SUB32) 1402 continue; 1403 break; 1404 case EM_LOONGARCH: 1405 if (!strcmp("__ex_table", fromsec) && 1406 r_type == R_LARCH_SUB32) 1407 continue; 1408 break; 1409 } 1410 1411 check_section_mismatch(mod, elf, tsym, 1412 fsecndx, fromsec, r_offset, taddr); 1413 } 1414 } 1415 1416 static void section_rel(struct module *mod, struct elf_info *elf, 1417 unsigned int fsecndx, const char *fromsec, 1418 const Elf_Rel *start, const Elf_Rel *stop) 1419 { 1420 const Elf_Rel *rel; 1421 1422 for (rel = start; rel < stop; rel++) { 1423 Elf_Sym *tsym; 1424 Elf_Addr taddr = 0, r_offset; 1425 unsigned int r_type, r_sym; 1426 void *loc; 1427 1428 r_offset = TO_NATIVE(rel->r_offset); 1429 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1430 1431 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1432 tsym = elf->symtab_start + r_sym; 1433 1434 switch (elf->hdr->e_machine) { 1435 case EM_386: 1436 taddr = addend_386_rel(loc, r_type); 1437 break; 1438 case EM_ARM: 1439 taddr = addend_arm_rel(loc, tsym, r_type); 1440 break; 1441 case EM_MIPS: 1442 taddr = addend_mips_rel(loc, r_type); 1443 break; 1444 default: 1445 fatal("Please add code to calculate addend for this architecture\n"); 1446 } 1447 1448 check_section_mismatch(mod, elf, tsym, 1449 fsecndx, fromsec, r_offset, taddr); 1450 } 1451 } 1452 1453 /** 1454 * A module includes a number of sections that are discarded 1455 * either when loaded or when used as built-in. 1456 * For loaded modules all functions marked __init and all data 1457 * marked __initdata will be discarded when the module has been initialized. 1458 * Likewise for modules used built-in the sections marked __exit 1459 * are discarded because __exit marked function are supposed to be called 1460 * only when a module is unloaded which never happens for built-in modules. 1461 * The check_sec_ref() function traverses all relocation records 1462 * to find all references to a section that reference a section that will 1463 * be discarded and warns about it. 1464 **/ 1465 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1466 { 1467 int i; 1468 1469 /* Walk through all sections */ 1470 for (i = 0; i < elf->num_sections; i++) { 1471 Elf_Shdr *sechdr = &elf->sechdrs[i]; 1472 1473 check_section(mod->name, elf, sechdr); 1474 /* We want to process only relocation sections and not .init */ 1475 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) { 1476 /* section to which the relocation applies */ 1477 unsigned int secndx = sechdr->sh_info; 1478 const char *secname = sec_name(elf, secndx); 1479 const void *start, *stop; 1480 1481 /* If the section is known good, skip it */ 1482 if (match(secname, section_white_list)) 1483 continue; 1484 1485 start = sym_get_data_by_offset(elf, i, 0); 1486 stop = start + sechdr->sh_size; 1487 1488 if (sechdr->sh_type == SHT_RELA) 1489 section_rela(mod, elf, secndx, secname, 1490 start, stop); 1491 else 1492 section_rel(mod, elf, secndx, secname, 1493 start, stop); 1494 } 1495 } 1496 } 1497 1498 static char *remove_dot(char *s) 1499 { 1500 size_t n = strcspn(s, "."); 1501 1502 if (n && s[n]) { 1503 size_t m = strspn(s + n + 1, "0123456789"); 1504 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1505 s[n] = 0; 1506 } 1507 return s; 1508 } 1509 1510 /* 1511 * The CRCs are recorded in .*.cmd files in the form of: 1512 * #SYMVER <name> <crc> 1513 */ 1514 static void extract_crcs_for_object(const char *object, struct module *mod) 1515 { 1516 char cmd_file[PATH_MAX]; 1517 char *buf, *p; 1518 const char *base; 1519 int dirlen, ret; 1520 1521 base = strrchr(object, '/'); 1522 if (base) { 1523 base++; 1524 dirlen = base - object; 1525 } else { 1526 dirlen = 0; 1527 base = object; 1528 } 1529 1530 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1531 dirlen, object, base); 1532 if (ret >= sizeof(cmd_file)) { 1533 error("%s: too long path was truncated\n", cmd_file); 1534 return; 1535 } 1536 1537 buf = read_text_file(cmd_file); 1538 p = buf; 1539 1540 while ((p = strstr(p, "\n#SYMVER "))) { 1541 char *name; 1542 size_t namelen; 1543 unsigned int crc; 1544 struct symbol *sym; 1545 1546 name = p + strlen("\n#SYMVER "); 1547 1548 p = strchr(name, ' '); 1549 if (!p) 1550 break; 1551 1552 namelen = p - name; 1553 p++; 1554 1555 if (!isdigit(*p)) 1556 continue; /* skip this line */ 1557 1558 crc = strtoul(p, &p, 0); 1559 if (*p != '\n') 1560 continue; /* skip this line */ 1561 1562 name[namelen] = '\0'; 1563 1564 /* 1565 * sym_find_with_module() may return NULL here. 1566 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1567 * Since commit e1327a127703, genksyms calculates CRCs of all 1568 * symbols, including trimmed ones. Ignore orphan CRCs. 1569 */ 1570 sym = sym_find_with_module(name, mod); 1571 if (sym) 1572 sym_set_crc(sym, crc); 1573 } 1574 1575 free(buf); 1576 } 1577 1578 /* 1579 * The symbol versions (CRC) are recorded in the .*.cmd files. 1580 * Parse them to retrieve CRCs for the current module. 1581 */ 1582 static void mod_set_crcs(struct module *mod) 1583 { 1584 char objlist[PATH_MAX]; 1585 char *buf, *p, *obj; 1586 int ret; 1587 1588 if (mod->is_vmlinux) { 1589 strcpy(objlist, ".vmlinux.objs"); 1590 } else { 1591 /* objects for a module are listed in the *.mod file. */ 1592 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1593 if (ret >= sizeof(objlist)) { 1594 error("%s: too long path was truncated\n", objlist); 1595 return; 1596 } 1597 } 1598 1599 buf = read_text_file(objlist); 1600 p = buf; 1601 1602 while ((obj = strsep(&p, "\n")) && obj[0]) 1603 extract_crcs_for_object(obj, mod); 1604 1605 free(buf); 1606 } 1607 1608 static void read_symbols(const char *modname) 1609 { 1610 const char *symname; 1611 char *version; 1612 char *license; 1613 char *namespace; 1614 struct module *mod; 1615 struct elf_info info = { }; 1616 Elf_Sym *sym; 1617 1618 if (!parse_elf(&info, modname)) 1619 return; 1620 1621 if (!strends(modname, ".o")) { 1622 error("%s: filename must be suffixed with .o\n", modname); 1623 return; 1624 } 1625 1626 /* strip trailing .o */ 1627 mod = new_module(modname, strlen(modname) - strlen(".o")); 1628 1629 if (!mod->is_vmlinux) { 1630 license = get_modinfo(&info, "license"); 1631 if (!license) 1632 error("missing MODULE_LICENSE() in %s\n", modname); 1633 while (license) { 1634 if (!license_is_gpl_compatible(license)) { 1635 mod->is_gpl_compatible = false; 1636 break; 1637 } 1638 license = get_next_modinfo(&info, "license", license); 1639 } 1640 1641 namespace = get_modinfo(&info, "import_ns"); 1642 while (namespace) { 1643 add_namespace(&mod->imported_namespaces, namespace); 1644 namespace = get_next_modinfo(&info, "import_ns", 1645 namespace); 1646 } 1647 } 1648 1649 if (extra_warn && !get_modinfo(&info, "description")) 1650 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1651 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1652 symname = remove_dot(info.strtab + sym->st_name); 1653 1654 handle_symbol(mod, &info, sym, symname); 1655 handle_moddevtable(mod, &info, sym, symname); 1656 } 1657 1658 check_sec_ref(mod, &info); 1659 1660 if (!mod->is_vmlinux) { 1661 version = get_modinfo(&info, "version"); 1662 if (version || all_versions) 1663 get_src_version(mod->name, mod->srcversion, 1664 sizeof(mod->srcversion) - 1); 1665 } 1666 1667 parse_elf_finish(&info); 1668 1669 if (modversions) { 1670 /* 1671 * Our trick to get versioning for module struct etc. - it's 1672 * never passed as an argument to an exported function, so 1673 * the automatic versioning doesn't pick it up, but it's really 1674 * important anyhow. 1675 */ 1676 sym_add_unresolved("module_layout", mod, false); 1677 1678 mod_set_crcs(mod); 1679 } 1680 } 1681 1682 static void read_symbols_from_files(const char *filename) 1683 { 1684 FILE *in = stdin; 1685 char fname[PATH_MAX]; 1686 1687 in = fopen(filename, "r"); 1688 if (!in) 1689 fatal("Can't open filenames file %s: %m", filename); 1690 1691 while (fgets(fname, PATH_MAX, in) != NULL) { 1692 if (strends(fname, "\n")) 1693 fname[strlen(fname)-1] = '\0'; 1694 read_symbols(fname); 1695 } 1696 1697 fclose(in); 1698 } 1699 1700 #define SZ 500 1701 1702 /* We first write the generated file into memory using the 1703 * following helper, then compare to the file on disk and 1704 * only update the later if anything changed */ 1705 1706 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1707 const char *fmt, ...) 1708 { 1709 char tmp[SZ]; 1710 int len; 1711 va_list ap; 1712 1713 va_start(ap, fmt); 1714 len = vsnprintf(tmp, SZ, fmt, ap); 1715 buf_write(buf, tmp, len); 1716 va_end(ap); 1717 } 1718 1719 void buf_write(struct buffer *buf, const char *s, int len) 1720 { 1721 if (buf->size - buf->pos < len) { 1722 buf->size += len + SZ; 1723 buf->p = NOFAIL(realloc(buf->p, buf->size)); 1724 } 1725 strncpy(buf->p + buf->pos, s, len); 1726 buf->pos += len; 1727 } 1728 1729 static void check_exports(struct module *mod) 1730 { 1731 struct symbol *s, *exp; 1732 1733 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1734 const char *basename; 1735 exp = find_symbol(s->name); 1736 if (!exp) { 1737 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1738 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, 1739 "\"%s\" [%s.ko] undefined!\n", 1740 s->name, mod->name); 1741 continue; 1742 } 1743 if (exp->module == mod) { 1744 error("\"%s\" [%s.ko] was exported without definition\n", 1745 s->name, mod->name); 1746 continue; 1747 } 1748 1749 exp->used = true; 1750 s->module = exp->module; 1751 s->crc_valid = exp->crc_valid; 1752 s->crc = exp->crc; 1753 1754 basename = strrchr(mod->name, '/'); 1755 if (basename) 1756 basename++; 1757 else 1758 basename = mod->name; 1759 1760 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1761 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, 1762 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1763 basename, exp->name, exp->namespace); 1764 add_namespace(&mod->missing_namespaces, exp->namespace); 1765 } 1766 1767 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1768 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1769 basename, exp->name); 1770 } 1771 } 1772 1773 static void handle_white_list_exports(const char *white_list) 1774 { 1775 char *buf, *p, *name; 1776 1777 buf = read_text_file(white_list); 1778 p = buf; 1779 1780 while ((name = strsep(&p, "\n"))) { 1781 struct symbol *sym = find_symbol(name); 1782 1783 if (sym) 1784 sym->used = true; 1785 } 1786 1787 free(buf); 1788 } 1789 1790 static void check_modname_len(struct module *mod) 1791 { 1792 const char *mod_name; 1793 1794 mod_name = strrchr(mod->name, '/'); 1795 if (mod_name == NULL) 1796 mod_name = mod->name; 1797 else 1798 mod_name++; 1799 if (strlen(mod_name) >= MODULE_NAME_LEN) 1800 error("module name is too long [%s.ko]\n", mod->name); 1801 } 1802 1803 /** 1804 * Header for the generated file 1805 **/ 1806 static void add_header(struct buffer *b, struct module *mod) 1807 { 1808 buf_printf(b, "#include <linux/module.h>\n"); 1809 /* 1810 * Include build-salt.h after module.h in order to 1811 * inherit the definitions. 1812 */ 1813 buf_printf(b, "#define INCLUDE_VERMAGIC\n"); 1814 buf_printf(b, "#include <linux/build-salt.h>\n"); 1815 buf_printf(b, "#include <linux/elfnote-lto.h>\n"); 1816 buf_printf(b, "#include <linux/export-internal.h>\n"); 1817 buf_printf(b, "#include <linux/vermagic.h>\n"); 1818 buf_printf(b, "#include <linux/compiler.h>\n"); 1819 buf_printf(b, "\n"); 1820 buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n"); 1821 buf_printf(b, "#include <asm/orc_header.h>\n"); 1822 buf_printf(b, "ORC_HEADER;\n"); 1823 buf_printf(b, "#endif\n"); 1824 buf_printf(b, "\n"); 1825 buf_printf(b, "BUILD_SALT;\n"); 1826 buf_printf(b, "BUILD_LTO_INFO;\n"); 1827 buf_printf(b, "\n"); 1828 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1829 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1830 buf_printf(b, "\n"); 1831 buf_printf(b, "__visible struct module __this_module\n"); 1832 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1833 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1834 if (mod->has_init) 1835 buf_printf(b, "\t.init = init_module,\n"); 1836 if (mod->has_cleanup) 1837 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1838 "\t.exit = cleanup_module,\n" 1839 "#endif\n"); 1840 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1841 buf_printf(b, "};\n"); 1842 1843 if (!external_module) 1844 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1845 1846 buf_printf(b, 1847 "\n" 1848 "#ifdef CONFIG_RETPOLINE\n" 1849 "MODULE_INFO(retpoline, \"Y\");\n" 1850 "#endif\n"); 1851 1852 if (strstarts(mod->name, "drivers/staging")) 1853 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1854 1855 if (strstarts(mod->name, "tools/testing")) 1856 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1857 } 1858 1859 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1860 { 1861 struct symbol *sym; 1862 1863 /* generate struct for exported symbols */ 1864 buf_printf(buf, "\n"); 1865 list_for_each_entry(sym, &mod->exported_symbols, list) { 1866 if (trim_unused_exports && !sym->used) 1867 continue; 1868 1869 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1870 sym->is_func ? "FUNC" : "DATA", sym->name, 1871 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1872 } 1873 1874 if (!modversions) 1875 return; 1876 1877 /* record CRCs for exported symbols */ 1878 buf_printf(buf, "\n"); 1879 list_for_each_entry(sym, &mod->exported_symbols, list) { 1880 if (trim_unused_exports && !sym->used) 1881 continue; 1882 1883 if (!sym->crc_valid) 1884 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1885 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1886 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1887 sym->name); 1888 1889 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1890 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1891 } 1892 } 1893 1894 /** 1895 * Record CRCs for unresolved symbols 1896 **/ 1897 static void add_versions(struct buffer *b, struct module *mod) 1898 { 1899 struct symbol *s; 1900 1901 if (!modversions) 1902 return; 1903 1904 buf_printf(b, "\n"); 1905 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1906 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1907 1908 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1909 if (!s->module) 1910 continue; 1911 if (!s->crc_valid) { 1912 warn("\"%s\" [%s.ko] has no CRC!\n", 1913 s->name, mod->name); 1914 continue; 1915 } 1916 if (strlen(s->name) >= MODULE_NAME_LEN) { 1917 error("too long symbol \"%s\" [%s.ko]\n", 1918 s->name, mod->name); 1919 break; 1920 } 1921 buf_printf(b, "\t{ %#8x, \"%s\" },\n", 1922 s->crc, s->name); 1923 } 1924 1925 buf_printf(b, "};\n"); 1926 } 1927 1928 static void add_depends(struct buffer *b, struct module *mod) 1929 { 1930 struct symbol *s; 1931 int first = 1; 1932 1933 /* Clear ->seen flag of modules that own symbols needed by this. */ 1934 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1935 if (s->module) 1936 s->module->seen = s->module->is_vmlinux; 1937 } 1938 1939 buf_printf(b, "\n"); 1940 buf_printf(b, "MODULE_INFO(depends, \""); 1941 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1942 const char *p; 1943 if (!s->module) 1944 continue; 1945 1946 if (s->module->seen) 1947 continue; 1948 1949 s->module->seen = true; 1950 p = strrchr(s->module->name, '/'); 1951 if (p) 1952 p++; 1953 else 1954 p = s->module->name; 1955 buf_printf(b, "%s%s", first ? "" : ",", p); 1956 first = 0; 1957 } 1958 buf_printf(b, "\");\n"); 1959 } 1960 1961 static void add_srcversion(struct buffer *b, struct module *mod) 1962 { 1963 if (mod->srcversion[0]) { 1964 buf_printf(b, "\n"); 1965 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1966 mod->srcversion); 1967 } 1968 } 1969 1970 static void write_buf(struct buffer *b, const char *fname) 1971 { 1972 FILE *file; 1973 1974 if (error_occurred) 1975 return; 1976 1977 file = fopen(fname, "w"); 1978 if (!file) { 1979 perror(fname); 1980 exit(1); 1981 } 1982 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1983 perror(fname); 1984 exit(1); 1985 } 1986 if (fclose(file) != 0) { 1987 perror(fname); 1988 exit(1); 1989 } 1990 } 1991 1992 static void write_if_changed(struct buffer *b, const char *fname) 1993 { 1994 char *tmp; 1995 FILE *file; 1996 struct stat st; 1997 1998 file = fopen(fname, "r"); 1999 if (!file) 2000 goto write; 2001 2002 if (fstat(fileno(file), &st) < 0) 2003 goto close_write; 2004 2005 if (st.st_size != b->pos) 2006 goto close_write; 2007 2008 tmp = NOFAIL(malloc(b->pos)); 2009 if (fread(tmp, 1, b->pos, file) != b->pos) 2010 goto free_write; 2011 2012 if (memcmp(tmp, b->p, b->pos) != 0) 2013 goto free_write; 2014 2015 free(tmp); 2016 fclose(file); 2017 return; 2018 2019 free_write: 2020 free(tmp); 2021 close_write: 2022 fclose(file); 2023 write: 2024 write_buf(b, fname); 2025 } 2026 2027 static void write_vmlinux_export_c_file(struct module *mod) 2028 { 2029 struct buffer buf = { }; 2030 2031 buf_printf(&buf, 2032 "#include <linux/export-internal.h>\n"); 2033 2034 add_exported_symbols(&buf, mod); 2035 write_if_changed(&buf, ".vmlinux.export.c"); 2036 free(buf.p); 2037 } 2038 2039 /* do sanity checks, and generate *.mod.c file */ 2040 static void write_mod_c_file(struct module *mod) 2041 { 2042 struct buffer buf = { }; 2043 char fname[PATH_MAX]; 2044 int ret; 2045 2046 add_header(&buf, mod); 2047 add_exported_symbols(&buf, mod); 2048 add_versions(&buf, mod); 2049 add_depends(&buf, mod); 2050 add_moddevtable(&buf, mod); 2051 add_srcversion(&buf, mod); 2052 2053 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2054 if (ret >= sizeof(fname)) { 2055 error("%s: too long path was truncated\n", fname); 2056 goto free; 2057 } 2058 2059 write_if_changed(&buf, fname); 2060 2061 free: 2062 free(buf.p); 2063 } 2064 2065 /* parse Module.symvers file. line format: 2066 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2067 **/ 2068 static void read_dump(const char *fname) 2069 { 2070 char *buf, *pos, *line; 2071 2072 buf = read_text_file(fname); 2073 if (!buf) 2074 /* No symbol versions, silently ignore */ 2075 return; 2076 2077 pos = buf; 2078 2079 while ((line = get_line(&pos))) { 2080 char *symname, *namespace, *modname, *d, *export; 2081 unsigned int crc; 2082 struct module *mod; 2083 struct symbol *s; 2084 bool gpl_only; 2085 2086 if (!(symname = strchr(line, '\t'))) 2087 goto fail; 2088 *symname++ = '\0'; 2089 if (!(modname = strchr(symname, '\t'))) 2090 goto fail; 2091 *modname++ = '\0'; 2092 if (!(export = strchr(modname, '\t'))) 2093 goto fail; 2094 *export++ = '\0'; 2095 if (!(namespace = strchr(export, '\t'))) 2096 goto fail; 2097 *namespace++ = '\0'; 2098 2099 crc = strtoul(line, &d, 16); 2100 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2101 goto fail; 2102 2103 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2104 gpl_only = true; 2105 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2106 gpl_only = false; 2107 } else { 2108 error("%s: unknown license %s. skip", symname, export); 2109 continue; 2110 } 2111 2112 mod = find_module(modname); 2113 if (!mod) { 2114 mod = new_module(modname, strlen(modname)); 2115 mod->from_dump = true; 2116 } 2117 s = sym_add_exported(symname, mod, gpl_only, namespace); 2118 sym_set_crc(s, crc); 2119 } 2120 free(buf); 2121 return; 2122 fail: 2123 free(buf); 2124 fatal("parse error in symbol dump file\n"); 2125 } 2126 2127 static void write_dump(const char *fname) 2128 { 2129 struct buffer buf = { }; 2130 struct module *mod; 2131 struct symbol *sym; 2132 2133 list_for_each_entry(mod, &modules, list) { 2134 if (mod->from_dump) 2135 continue; 2136 list_for_each_entry(sym, &mod->exported_symbols, list) { 2137 if (trim_unused_exports && !sym->used) 2138 continue; 2139 2140 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2141 sym->crc, sym->name, mod->name, 2142 sym->is_gpl_only ? "_GPL" : "", 2143 sym->namespace); 2144 } 2145 } 2146 write_buf(&buf, fname); 2147 free(buf.p); 2148 } 2149 2150 static void write_namespace_deps_files(const char *fname) 2151 { 2152 struct module *mod; 2153 struct namespace_list *ns; 2154 struct buffer ns_deps_buf = {}; 2155 2156 list_for_each_entry(mod, &modules, list) { 2157 2158 if (mod->from_dump || list_empty(&mod->missing_namespaces)) 2159 continue; 2160 2161 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2162 2163 list_for_each_entry(ns, &mod->missing_namespaces, list) 2164 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2165 2166 buf_printf(&ns_deps_buf, "\n"); 2167 } 2168 2169 write_if_changed(&ns_deps_buf, fname); 2170 free(ns_deps_buf.p); 2171 } 2172 2173 struct dump_list { 2174 struct list_head list; 2175 const char *file; 2176 }; 2177 2178 int main(int argc, char **argv) 2179 { 2180 struct module *mod; 2181 char *missing_namespace_deps = NULL; 2182 char *unused_exports_white_list = NULL; 2183 char *dump_write = NULL, *files_source = NULL; 2184 int opt; 2185 LIST_HEAD(dump_lists); 2186 struct dump_list *dl, *dl2; 2187 2188 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) { 2189 switch (opt) { 2190 case 'e': 2191 external_module = true; 2192 break; 2193 case 'i': 2194 dl = NOFAIL(malloc(sizeof(*dl))); 2195 dl->file = optarg; 2196 list_add_tail(&dl->list, &dump_lists); 2197 break; 2198 case 'M': 2199 module_enabled = true; 2200 break; 2201 case 'm': 2202 modversions = true; 2203 break; 2204 case 'n': 2205 ignore_missing_files = true; 2206 break; 2207 case 'o': 2208 dump_write = optarg; 2209 break; 2210 case 'a': 2211 all_versions = true; 2212 break; 2213 case 'T': 2214 files_source = optarg; 2215 break; 2216 case 't': 2217 trim_unused_exports = true; 2218 break; 2219 case 'u': 2220 unused_exports_white_list = optarg; 2221 break; 2222 case 'W': 2223 extra_warn = true; 2224 break; 2225 case 'w': 2226 warn_unresolved = true; 2227 break; 2228 case 'E': 2229 sec_mismatch_warn_only = false; 2230 break; 2231 case 'N': 2232 allow_missing_ns_imports = true; 2233 break; 2234 case 'd': 2235 missing_namespace_deps = optarg; 2236 break; 2237 default: 2238 exit(1); 2239 } 2240 } 2241 2242 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2243 read_dump(dl->file); 2244 list_del(&dl->list); 2245 free(dl); 2246 } 2247 2248 while (optind < argc) 2249 read_symbols(argv[optind++]); 2250 2251 if (files_source) 2252 read_symbols_from_files(files_source); 2253 2254 list_for_each_entry(mod, &modules, list) { 2255 if (mod->from_dump || mod->is_vmlinux) 2256 continue; 2257 2258 check_modname_len(mod); 2259 check_exports(mod); 2260 } 2261 2262 if (unused_exports_white_list) 2263 handle_white_list_exports(unused_exports_white_list); 2264 2265 list_for_each_entry(mod, &modules, list) { 2266 if (mod->from_dump) 2267 continue; 2268 2269 if (mod->is_vmlinux) 2270 write_vmlinux_export_c_file(mod); 2271 else 2272 write_mod_c_file(mod); 2273 } 2274 2275 if (missing_namespace_deps) 2276 write_namespace_deps_files(missing_namespace_deps); 2277 2278 if (dump_write) 2279 write_dump(dump_write); 2280 if (sec_mismatch_count && !sec_mismatch_warn_only) 2281 error("Section mismatches detected.\n" 2282 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2283 2284 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2285 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2286 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2287 2288 return error_occurred ? 1 : 0; 2289 } 2290