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 #include "../../include/linux/module_symbol.h" 26 27 static bool module_enabled; 28 /* Are we using CONFIG_MODVERSIONS? */ 29 static bool modversions; 30 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 31 static bool all_versions; 32 /* If we are modposting external module set to 1 */ 33 static bool external_module; 34 /* Only warn about unresolved symbols */ 35 static bool warn_unresolved; 36 37 static int sec_mismatch_count; 38 static bool sec_mismatch_warn_only = true; 39 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */ 40 static bool trim_unused_exports; 41 42 /* ignore missing files */ 43 static bool ignore_missing_files; 44 /* If set to 1, only warn (instead of error) about missing ns imports */ 45 static bool allow_missing_ns_imports; 46 47 static bool error_occurred; 48 49 static bool extra_warn; 50 51 /* 52 * Cut off the warnings when there are too many. This typically occurs when 53 * vmlinux is missing. ('make modules' without building vmlinux.) 54 */ 55 #define MAX_UNRESOLVED_REPORTS 10 56 static unsigned int nr_unresolved; 57 58 /* In kernel, this size is defined in linux/module.h; 59 * here we use Elf_Addr instead of long for covering cross-compile 60 */ 61 62 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) 63 64 void __attribute__((format(printf, 2, 3))) 65 modpost_log(enum loglevel loglevel, const char *fmt, ...) 66 { 67 va_list arglist; 68 69 switch (loglevel) { 70 case LOG_WARN: 71 fprintf(stderr, "WARNING: "); 72 break; 73 case LOG_ERROR: 74 fprintf(stderr, "ERROR: "); 75 break; 76 case LOG_FATAL: 77 fprintf(stderr, "FATAL: "); 78 break; 79 default: /* invalid loglevel, ignore */ 80 break; 81 } 82 83 fprintf(stderr, "modpost: "); 84 85 va_start(arglist, fmt); 86 vfprintf(stderr, fmt, arglist); 87 va_end(arglist); 88 89 if (loglevel == LOG_FATAL) 90 exit(1); 91 if (loglevel == LOG_ERROR) 92 error_occurred = true; 93 } 94 95 static inline bool strends(const char *str, const char *postfix) 96 { 97 if (strlen(str) < strlen(postfix)) 98 return false; 99 100 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; 101 } 102 103 void *do_nofail(void *ptr, const char *expr) 104 { 105 if (!ptr) 106 fatal("Memory allocation failure: %s.\n", expr); 107 108 return ptr; 109 } 110 111 char *read_text_file(const char *filename) 112 { 113 struct stat st; 114 size_t nbytes; 115 int fd; 116 char *buf; 117 118 fd = open(filename, O_RDONLY); 119 if (fd < 0) { 120 perror(filename); 121 exit(1); 122 } 123 124 if (fstat(fd, &st) < 0) { 125 perror(filename); 126 exit(1); 127 } 128 129 buf = NOFAIL(malloc(st.st_size + 1)); 130 131 nbytes = st.st_size; 132 133 while (nbytes) { 134 ssize_t bytes_read; 135 136 bytes_read = read(fd, buf, nbytes); 137 if (bytes_read < 0) { 138 perror(filename); 139 exit(1); 140 } 141 142 nbytes -= bytes_read; 143 } 144 buf[st.st_size] = '\0'; 145 146 close(fd); 147 148 return buf; 149 } 150 151 char *get_line(char **stringp) 152 { 153 char *orig = *stringp, *next; 154 155 /* do not return the unwanted extra line at EOF */ 156 if (!orig || *orig == '\0') 157 return NULL; 158 159 /* don't use strsep here, it is not available everywhere */ 160 next = strchr(orig, '\n'); 161 if (next) 162 *next++ = '\0'; 163 164 *stringp = next; 165 166 return orig; 167 } 168 169 /* A list of all modules we processed */ 170 LIST_HEAD(modules); 171 172 static struct module *find_module(const char *modname) 173 { 174 struct module *mod; 175 176 list_for_each_entry(mod, &modules, list) { 177 if (strcmp(mod->name, modname) == 0) 178 return mod; 179 } 180 return NULL; 181 } 182 183 static struct module *new_module(const char *name, size_t namelen) 184 { 185 struct module *mod; 186 187 mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1)); 188 memset(mod, 0, sizeof(*mod)); 189 190 INIT_LIST_HEAD(&mod->exported_symbols); 191 INIT_LIST_HEAD(&mod->unresolved_symbols); 192 INIT_LIST_HEAD(&mod->missing_namespaces); 193 INIT_LIST_HEAD(&mod->imported_namespaces); 194 195 memcpy(mod->name, name, namelen); 196 mod->name[namelen] = '\0'; 197 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0); 198 199 /* 200 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE() 201 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue 202 * modpost will exit wiht error anyway. 203 */ 204 mod->is_gpl_compatible = true; 205 206 list_add_tail(&mod->list, &modules); 207 208 return mod; 209 } 210 211 /* A hash of all exported symbols, 212 * struct symbol is also used for lists of unresolved symbols */ 213 214 #define SYMBOL_HASH_SIZE 1024 215 216 struct symbol { 217 struct symbol *next; 218 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */ 219 struct module *module; 220 char *namespace; 221 unsigned int crc; 222 bool crc_valid; 223 bool weak; 224 bool is_func; 225 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ 226 bool used; /* there exists a user of this symbol */ 227 char name[]; 228 }; 229 230 static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 231 232 /* This is based on the hash algorithm from gdbm, via tdb */ 233 static inline unsigned int tdb_hash(const char *name) 234 { 235 unsigned value; /* Used to compute the hash value. */ 236 unsigned i; /* Used to cycle through random values. */ 237 238 /* Set the initial value from the key size. */ 239 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++) 240 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 241 242 return (1103515243 * value + 12345); 243 } 244 245 /** 246 * Allocate a new symbols for use in the hash of exported symbols or 247 * the list of unresolved symbols per module 248 **/ 249 static struct symbol *alloc_symbol(const char *name) 250 { 251 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 252 253 memset(s, 0, sizeof(*s)); 254 strcpy(s->name, name); 255 256 return s; 257 } 258 259 /* For the hash of exported symbols */ 260 static void hash_add_symbol(struct symbol *sym) 261 { 262 unsigned int hash; 263 264 hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE; 265 sym->next = symbolhash[hash]; 266 symbolhash[hash] = sym; 267 } 268 269 static void sym_add_unresolved(const char *name, struct module *mod, bool weak) 270 { 271 struct symbol *sym; 272 273 sym = alloc_symbol(name); 274 sym->weak = weak; 275 276 list_add_tail(&sym->list, &mod->unresolved_symbols); 277 } 278 279 static struct symbol *sym_find_with_module(const char *name, struct module *mod) 280 { 281 struct symbol *s; 282 283 /* For our purposes, .foo matches foo. PPC64 needs this. */ 284 if (name[0] == '.') 285 name++; 286 287 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) { 288 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) 289 return s; 290 } 291 return NULL; 292 } 293 294 static struct symbol *find_symbol(const char *name) 295 { 296 return sym_find_with_module(name, NULL); 297 } 298 299 struct namespace_list { 300 struct list_head list; 301 char namespace[]; 302 }; 303 304 static bool contains_namespace(struct list_head *head, const char *namespace) 305 { 306 struct namespace_list *list; 307 308 /* 309 * The default namespace is null string "", which is always implicitly 310 * contained. 311 */ 312 if (!namespace[0]) 313 return true; 314 315 list_for_each_entry(list, head, list) { 316 if (!strcmp(list->namespace, namespace)) 317 return true; 318 } 319 320 return false; 321 } 322 323 static void add_namespace(struct list_head *head, const char *namespace) 324 { 325 struct namespace_list *ns_entry; 326 327 if (!contains_namespace(head, namespace)) { 328 ns_entry = NOFAIL(malloc(sizeof(*ns_entry) + 329 strlen(namespace) + 1)); 330 strcpy(ns_entry->namespace, namespace); 331 list_add_tail(&ns_entry->list, head); 332 } 333 } 334 335 static void *sym_get_data_by_offset(const struct elf_info *info, 336 unsigned int secindex, unsigned long offset) 337 { 338 Elf_Shdr *sechdr = &info->sechdrs[secindex]; 339 340 return (void *)info->hdr + sechdr->sh_offset + offset; 341 } 342 343 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) 344 { 345 return sym_get_data_by_offset(info, get_secindex(info, sym), 346 sym->st_value); 347 } 348 349 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) 350 { 351 return sym_get_data_by_offset(info, info->secindex_strings, 352 sechdr->sh_name); 353 } 354 355 static const char *sec_name(const struct elf_info *info, unsigned int secindex) 356 { 357 /* 358 * If sym->st_shndx is a special section index, there is no 359 * corresponding section header. 360 * Return "" if the index is out of range of info->sechdrs[] array. 361 */ 362 if (secindex >= info->num_sections) 363 return ""; 364 365 return sech_name(info, &info->sechdrs[secindex]); 366 } 367 368 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) 369 370 static struct symbol *sym_add_exported(const char *name, struct module *mod, 371 bool gpl_only, const char *namespace) 372 { 373 struct symbol *s = find_symbol(name); 374 375 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { 376 error("%s: '%s' exported twice. Previous export was in %s%s\n", 377 mod->name, name, s->module->name, 378 s->module->is_vmlinux ? "" : ".ko"); 379 } 380 381 s = alloc_symbol(name); 382 s->module = mod; 383 s->is_gpl_only = gpl_only; 384 s->namespace = NOFAIL(strdup(namespace)); 385 list_add_tail(&s->list, &mod->exported_symbols); 386 hash_add_symbol(s); 387 388 return s; 389 } 390 391 static void sym_set_crc(struct symbol *sym, unsigned int crc) 392 { 393 sym->crc = crc; 394 sym->crc_valid = true; 395 } 396 397 static void *grab_file(const char *filename, size_t *size) 398 { 399 struct stat st; 400 void *map = MAP_FAILED; 401 int fd; 402 403 fd = open(filename, O_RDONLY); 404 if (fd < 0) 405 return NULL; 406 if (fstat(fd, &st)) 407 goto failed; 408 409 *size = st.st_size; 410 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 411 412 failed: 413 close(fd); 414 if (map == MAP_FAILED) 415 return NULL; 416 return map; 417 } 418 419 static void release_file(void *file, size_t size) 420 { 421 munmap(file, size); 422 } 423 424 static int parse_elf(struct elf_info *info, const char *filename) 425 { 426 unsigned int i; 427 Elf_Ehdr *hdr; 428 Elf_Shdr *sechdrs; 429 Elf_Sym *sym; 430 const char *secstrings; 431 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 432 433 hdr = grab_file(filename, &info->size); 434 if (!hdr) { 435 if (ignore_missing_files) { 436 fprintf(stderr, "%s: %s (ignored)\n", filename, 437 strerror(errno)); 438 return 0; 439 } 440 perror(filename); 441 exit(1); 442 } 443 info->hdr = hdr; 444 if (info->size < sizeof(*hdr)) { 445 /* file too small, assume this is an empty .o file */ 446 return 0; 447 } 448 /* Is this a valid ELF file? */ 449 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 450 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 451 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 452 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 453 /* Not an ELF file - silently ignore it */ 454 return 0; 455 } 456 /* Fix endianness in ELF header */ 457 hdr->e_type = TO_NATIVE(hdr->e_type); 458 hdr->e_machine = TO_NATIVE(hdr->e_machine); 459 hdr->e_version = TO_NATIVE(hdr->e_version); 460 hdr->e_entry = TO_NATIVE(hdr->e_entry); 461 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 462 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 463 hdr->e_flags = TO_NATIVE(hdr->e_flags); 464 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 465 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 466 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 467 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 468 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 469 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 470 sechdrs = (void *)hdr + hdr->e_shoff; 471 info->sechdrs = sechdrs; 472 473 /* modpost only works for relocatable objects */ 474 if (hdr->e_type != ET_REL) 475 fatal("%s: not relocatable object.", filename); 476 477 /* Check if file offset is correct */ 478 if (hdr->e_shoff > info->size) { 479 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", 480 (unsigned long)hdr->e_shoff, filename, info->size); 481 return 0; 482 } 483 484 if (hdr->e_shnum == SHN_UNDEF) { 485 /* 486 * There are more than 64k sections, 487 * read count from .sh_size. 488 */ 489 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 490 } 491 else { 492 info->num_sections = hdr->e_shnum; 493 } 494 if (hdr->e_shstrndx == SHN_XINDEX) { 495 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 496 } 497 else { 498 info->secindex_strings = hdr->e_shstrndx; 499 } 500 501 /* Fix endianness in section headers */ 502 for (i = 0; i < info->num_sections; i++) { 503 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 504 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 505 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 506 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 507 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 508 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 509 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 510 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 511 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 512 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 513 } 514 /* Find symbol table. */ 515 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 516 for (i = 1; i < info->num_sections; i++) { 517 const char *secname; 518 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 519 520 if (!nobits && sechdrs[i].sh_offset > info->size) { 521 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n", 522 filename, (unsigned long)sechdrs[i].sh_offset, 523 sizeof(*hdr)); 524 return 0; 525 } 526 secname = secstrings + sechdrs[i].sh_name; 527 if (strcmp(secname, ".modinfo") == 0) { 528 if (nobits) 529 fatal("%s has NOBITS .modinfo\n", filename); 530 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 531 info->modinfo_len = sechdrs[i].sh_size; 532 } else if (!strcmp(secname, ".export_symbol")) { 533 info->export_symbol_secndx = i; 534 } 535 536 if (sechdrs[i].sh_type == SHT_SYMTAB) { 537 unsigned int sh_link_idx; 538 symtab_idx = i; 539 info->symtab_start = (void *)hdr + 540 sechdrs[i].sh_offset; 541 info->symtab_stop = (void *)hdr + 542 sechdrs[i].sh_offset + sechdrs[i].sh_size; 543 sh_link_idx = sechdrs[i].sh_link; 544 info->strtab = (void *)hdr + 545 sechdrs[sh_link_idx].sh_offset; 546 } 547 548 /* 32bit section no. table? ("more than 64k sections") */ 549 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 550 symtab_shndx_idx = i; 551 info->symtab_shndx_start = (void *)hdr + 552 sechdrs[i].sh_offset; 553 info->symtab_shndx_stop = (void *)hdr + 554 sechdrs[i].sh_offset + sechdrs[i].sh_size; 555 } 556 } 557 if (!info->symtab_start) 558 fatal("%s has no symtab?\n", filename); 559 560 /* Fix endianness in symbols */ 561 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 562 sym->st_shndx = TO_NATIVE(sym->st_shndx); 563 sym->st_name = TO_NATIVE(sym->st_name); 564 sym->st_value = TO_NATIVE(sym->st_value); 565 sym->st_size = TO_NATIVE(sym->st_size); 566 } 567 568 if (symtab_shndx_idx != ~0U) { 569 Elf32_Word *p; 570 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 571 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 572 filename, sechdrs[symtab_shndx_idx].sh_link, 573 symtab_idx); 574 /* Fix endianness */ 575 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 576 p++) 577 *p = TO_NATIVE(*p); 578 } 579 580 return 1; 581 } 582 583 static void parse_elf_finish(struct elf_info *info) 584 { 585 release_file(info->hdr, info->size); 586 } 587 588 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 589 { 590 /* ignore __this_module, it will be resolved shortly */ 591 if (strcmp(symname, "__this_module") == 0) 592 return 1; 593 /* ignore global offset table */ 594 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 595 return 1; 596 if (info->hdr->e_machine == EM_PPC) 597 /* Special register function linked on all modules during final link of .ko */ 598 if (strstarts(symname, "_restgpr_") || 599 strstarts(symname, "_savegpr_") || 600 strstarts(symname, "_rest32gpr_") || 601 strstarts(symname, "_save32gpr_") || 602 strstarts(symname, "_restvr_") || 603 strstarts(symname, "_savevr_")) 604 return 1; 605 if (info->hdr->e_machine == EM_PPC64) 606 /* Special register function linked on all modules during final link of .ko */ 607 if (strstarts(symname, "_restgpr0_") || 608 strstarts(symname, "_savegpr0_") || 609 strstarts(symname, "_restvr_") || 610 strstarts(symname, "_savevr_") || 611 strcmp(symname, ".TOC.") == 0) 612 return 1; 613 614 if (info->hdr->e_machine == EM_S390) 615 /* Expoline thunks are linked on all kernel modules during final link of .ko */ 616 if (strstarts(symname, "__s390_indirect_jump_r")) 617 return 1; 618 /* Do not ignore this symbol */ 619 return 0; 620 } 621 622 static void handle_symbol(struct module *mod, struct elf_info *info, 623 const Elf_Sym *sym, const char *symname) 624 { 625 switch (sym->st_shndx) { 626 case SHN_COMMON: 627 if (strstarts(symname, "__gnu_lto_")) { 628 /* Should warn here, but modpost runs before the linker */ 629 } else 630 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 631 break; 632 case SHN_UNDEF: 633 /* undefined symbol */ 634 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 635 ELF_ST_BIND(sym->st_info) != STB_WEAK) 636 break; 637 if (ignore_undef_symbol(info, symname)) 638 break; 639 if (info->hdr->e_machine == EM_SPARC || 640 info->hdr->e_machine == EM_SPARCV9) { 641 /* Ignore register directives. */ 642 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 643 break; 644 if (symname[0] == '.') { 645 char *munged = NOFAIL(strdup(symname)); 646 munged[0] = '_'; 647 munged[1] = toupper(munged[1]); 648 symname = munged; 649 } 650 } 651 652 sym_add_unresolved(symname, mod, 653 ELF_ST_BIND(sym->st_info) == STB_WEAK); 654 break; 655 default: 656 if (strcmp(symname, "init_module") == 0) 657 mod->has_init = true; 658 if (strcmp(symname, "cleanup_module") == 0) 659 mod->has_cleanup = true; 660 break; 661 } 662 } 663 664 /** 665 * Parse tag=value strings from .modinfo section 666 **/ 667 static char *next_string(char *string, unsigned long *secsize) 668 { 669 /* Skip non-zero chars */ 670 while (string[0]) { 671 string++; 672 if ((*secsize)-- <= 1) 673 return NULL; 674 } 675 676 /* Skip any zero padding. */ 677 while (!string[0]) { 678 string++; 679 if ((*secsize)-- <= 1) 680 return NULL; 681 } 682 return string; 683 } 684 685 static char *get_next_modinfo(struct elf_info *info, const char *tag, 686 char *prev) 687 { 688 char *p; 689 unsigned int taglen = strlen(tag); 690 char *modinfo = info->modinfo; 691 unsigned long size = info->modinfo_len; 692 693 if (prev) { 694 size -= prev - modinfo; 695 modinfo = next_string(prev, &size); 696 } 697 698 for (p = modinfo; p; p = next_string(p, &size)) { 699 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 700 return p + taglen + 1; 701 } 702 return NULL; 703 } 704 705 static char *get_modinfo(struct elf_info *info, const char *tag) 706 707 { 708 return get_next_modinfo(info, tag, NULL); 709 } 710 711 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 712 { 713 if (sym) 714 return elf->strtab + sym->st_name; 715 else 716 return "(unknown)"; 717 } 718 719 /* 720 * Check whether the 'string' argument matches one of the 'patterns', 721 * an array of shell wildcard patterns (glob). 722 * 723 * Return true is there is a match. 724 */ 725 static bool match(const char *string, const char *const patterns[]) 726 { 727 const char *pattern; 728 729 while ((pattern = *patterns++)) { 730 if (!fnmatch(pattern, string, 0)) 731 return true; 732 } 733 734 return false; 735 } 736 737 /* useful to pass patterns to match() directly */ 738 #define PATTERNS(...) \ 739 ({ \ 740 static const char *const patterns[] = {__VA_ARGS__, NULL}; \ 741 patterns; \ 742 }) 743 744 /* sections that we do not want to do full section mismatch check on */ 745 static const char *const section_white_list[] = 746 { 747 ".comment*", 748 ".debug*", 749 ".zdebug*", /* Compressed debug sections. */ 750 ".GCC.command.line", /* record-gcc-switches */ 751 ".mdebug*", /* alpha, score, mips etc. */ 752 ".pdr", /* alpha, score, mips etc. */ 753 ".stab*", 754 ".note*", 755 ".got*", 756 ".toc*", 757 ".xt.prop", /* xtensa */ 758 ".xt.lit", /* xtensa */ 759 ".arcextmap*", /* arc */ 760 ".gnu.linkonce.arcext*", /* arc : modules */ 761 ".cmem*", /* EZchip */ 762 ".fmt_slot*", /* EZchip */ 763 ".gnu.lto*", 764 ".discard.*", 765 ".llvm.call-graph-profile", /* call graph */ 766 NULL 767 }; 768 769 /* 770 * This is used to find sections missing the SHF_ALLOC flag. 771 * The cause of this is often a section specified in assembler 772 * without "ax" / "aw". 773 */ 774 static void check_section(const char *modname, struct elf_info *elf, 775 Elf_Shdr *sechdr) 776 { 777 const char *sec = sech_name(elf, sechdr); 778 779 if (sechdr->sh_type == SHT_PROGBITS && 780 !(sechdr->sh_flags & SHF_ALLOC) && 781 !match(sec, section_white_list)) { 782 warn("%s (%s): unexpected non-allocatable section.\n" 783 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 784 "Note that for example <linux/init.h> contains\n" 785 "section definitions for use in .S files.\n\n", 786 modname, sec); 787 } 788 } 789 790 791 792 #define ALL_INIT_DATA_SECTIONS \ 793 ".init.setup", ".init.rodata", ".meminit.rodata", \ 794 ".init.data", ".meminit.data" 795 #define ALL_EXIT_DATA_SECTIONS \ 796 ".exit.data", ".memexit.data" 797 798 #define ALL_INIT_TEXT_SECTIONS \ 799 ".init.text", ".meminit.text" 800 #define ALL_EXIT_TEXT_SECTIONS \ 801 ".exit.text", ".memexit.text" 802 803 #define ALL_PCI_INIT_SECTIONS \ 804 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 805 ".pci_fixup_enable", ".pci_fixup_resume", \ 806 ".pci_fixup_resume_early", ".pci_fixup_suspend" 807 808 #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS 809 #define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS 810 811 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 812 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS 813 814 #define DATA_SECTIONS ".data", ".data.rel" 815 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ 816 ".kprobes.text", ".cpuidle.text", ".noinstr.text" 817 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ 818 ".fixup", ".entry.text", ".exception.text", \ 819 ".coldtext", ".softirqentry.text" 820 821 #define INIT_SECTIONS ".init.*" 822 #define MEM_INIT_SECTIONS ".meminit.*" 823 824 #define EXIT_SECTIONS ".exit.*" 825 #define MEM_EXIT_SECTIONS ".memexit.*" 826 827 #define ALL_TEXT_SECTIONS ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \ 828 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 829 830 enum mismatch { 831 TEXT_TO_ANY_INIT, 832 DATA_TO_ANY_INIT, 833 TEXTDATA_TO_ANY_EXIT, 834 XXXINIT_TO_SOME_INIT, 835 XXXEXIT_TO_SOME_EXIT, 836 ANY_INIT_TO_ANY_EXIT, 837 ANY_EXIT_TO_ANY_INIT, 838 EXTABLE_TO_NON_TEXT, 839 }; 840 841 /** 842 * Describe how to match sections on different criteria: 843 * 844 * @fromsec: Array of sections to be matched. 845 * 846 * @bad_tosec: Relocations applied to a section in @fromsec to a section in 847 * this array is forbidden (black-list). Can be empty. 848 * 849 * @good_tosec: Relocations applied to a section in @fromsec must be 850 * targeting sections in this array (white-list). Can be empty. 851 * 852 * @mismatch: Type of mismatch. 853 */ 854 struct sectioncheck { 855 const char *fromsec[20]; 856 const char *bad_tosec[20]; 857 const char *good_tosec[20]; 858 enum mismatch mismatch; 859 }; 860 861 static const struct sectioncheck sectioncheck[] = { 862 /* Do not reference init/exit code/data from 863 * normal code and data 864 */ 865 { 866 .fromsec = { TEXT_SECTIONS, NULL }, 867 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 868 .mismatch = TEXT_TO_ANY_INIT, 869 }, 870 { 871 .fromsec = { DATA_SECTIONS, NULL }, 872 .bad_tosec = { ALL_XXXINIT_SECTIONS, INIT_SECTIONS, NULL }, 873 .mismatch = DATA_TO_ANY_INIT, 874 }, 875 { 876 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 877 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 878 .mismatch = TEXTDATA_TO_ANY_EXIT, 879 }, 880 /* Do not reference init code/data from meminit code/data */ 881 { 882 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 883 .bad_tosec = { INIT_SECTIONS, NULL }, 884 .mismatch = XXXINIT_TO_SOME_INIT, 885 }, 886 /* Do not reference exit code/data from memexit code/data */ 887 { 888 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL }, 889 .bad_tosec = { EXIT_SECTIONS, NULL }, 890 .mismatch = XXXEXIT_TO_SOME_EXIT, 891 }, 892 /* Do not use exit code/data from init code */ 893 { 894 .fromsec = { ALL_INIT_SECTIONS, NULL }, 895 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 896 .mismatch = ANY_INIT_TO_ANY_EXIT, 897 }, 898 /* Do not use init code/data from exit code */ 899 { 900 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 901 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 902 .mismatch = ANY_EXIT_TO_ANY_INIT, 903 }, 904 { 905 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 906 .bad_tosec = { INIT_SECTIONS, NULL }, 907 .mismatch = ANY_INIT_TO_ANY_EXIT, 908 }, 909 { 910 .fromsec = { "__ex_table", NULL }, 911 /* If you're adding any new black-listed sections in here, consider 912 * adding a special 'printer' for them in scripts/check_extable. 913 */ 914 .bad_tosec = { ".altinstr_replacement", NULL }, 915 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 916 .mismatch = EXTABLE_TO_NON_TEXT, 917 } 918 }; 919 920 static const struct sectioncheck *section_mismatch( 921 const char *fromsec, const char *tosec) 922 { 923 int i; 924 925 /* 926 * The target section could be the SHT_NUL section when we're 927 * handling relocations to un-resolved symbols, trying to match it 928 * doesn't make much sense and causes build failures on parisc 929 * architectures. 930 */ 931 if (*tosec == '\0') 932 return NULL; 933 934 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 935 const struct sectioncheck *check = §ioncheck[i]; 936 937 if (match(fromsec, check->fromsec)) { 938 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 939 return check; 940 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 941 return check; 942 } 943 } 944 return NULL; 945 } 946 947 /** 948 * Whitelist to allow certain references to pass with no warning. 949 * 950 * Pattern 1: 951 * If a module parameter is declared __initdata and permissions=0 952 * then this is legal despite the warning generated. 953 * We cannot see value of permissions here, so just ignore 954 * this pattern. 955 * The pattern is identified by: 956 * tosec = .init.data 957 * fromsec = .data* 958 * atsym =__param* 959 * 960 * Pattern 1a: 961 * module_param_call() ops can refer to __init set function if permissions=0 962 * The pattern is identified by: 963 * tosec = .init.text 964 * fromsec = .data* 965 * atsym = __param_ops_* 966 * 967 * Pattern 3: 968 * Whitelist all references from .head.text to any init section 969 * 970 * Pattern 4: 971 * Some symbols belong to init section but still it is ok to reference 972 * these from non-init sections as these symbols don't have any memory 973 * allocated for them and symbol address and value are same. So even 974 * if init section is freed, its ok to reference those symbols. 975 * For ex. symbols marking the init section boundaries. 976 * This pattern is identified by 977 * refsymname = __init_begin, _sinittext, _einittext 978 * 979 * Pattern 5: 980 * GCC may optimize static inlines when fed constant arg(s) resulting 981 * in functions like cpumask_empty() -- generating an associated symbol 982 * cpumask_empty.constprop.3 that appears in the audit. If the const that 983 * is passed in comes from __init, like say nmi_ipi_mask, we get a 984 * meaningless section warning. May need to add isra symbols too... 985 * This pattern is identified by 986 * tosec = init section 987 * fromsec = text section 988 * refsymname = *.constprop.* 989 * 990 **/ 991 static int secref_whitelist(const char *fromsec, const char *fromsym, 992 const char *tosec, const char *tosym) 993 { 994 /* Check for pattern 1 */ 995 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 996 match(fromsec, PATTERNS(DATA_SECTIONS)) && 997 strstarts(fromsym, "__param")) 998 return 0; 999 1000 /* Check for pattern 1a */ 1001 if (strcmp(tosec, ".init.text") == 0 && 1002 match(fromsec, PATTERNS(DATA_SECTIONS)) && 1003 strstarts(fromsym, "__param_ops_")) 1004 return 0; 1005 1006 /* symbols in data sections that may refer to any init/exit sections */ 1007 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 1008 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 1009 match(fromsym, PATTERNS("*_template", // scsi uses *_template a lot 1010 "*_timer", // arm uses ops structures named _timer a lot 1011 "*_sht", // scsi also used *_sht to some extent 1012 "*_ops", 1013 "*_probe", 1014 "*_probe_one", 1015 "*_console"))) 1016 return 0; 1017 1018 /* symbols in data sections that may refer to meminit/exit sections */ 1019 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 1020 match(tosec, PATTERNS(ALL_XXXINIT_SECTIONS, ALL_EXIT_SECTIONS)) && 1021 match(fromsym, PATTERNS("*driver"))) 1022 return 0; 1023 1024 /* Check for pattern 3 */ 1025 if (strstarts(fromsec, ".head.text") && 1026 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 1027 return 0; 1028 1029 /* Check for pattern 4 */ 1030 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 1031 return 0; 1032 1033 /* Check for pattern 5 */ 1034 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 1035 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 1036 match(fromsym, PATTERNS("*.constprop.*"))) 1037 return 0; 1038 1039 return 1; 1040 } 1041 1042 /* 1043 * If there's no name there, ignore it; likewise, ignore it if it's 1044 * one of the magic symbols emitted used by current tools. 1045 * 1046 * Otherwise if find_symbols_between() returns those symbols, they'll 1047 * fail the whitelist tests and cause lots of false alarms ... fixable 1048 * only by merging __exit and __init sections into __text, bloating 1049 * the kernel (which is especially evil on embedded platforms). 1050 */ 1051 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 1052 { 1053 const char *name = elf->strtab + sym->st_name; 1054 1055 if (!name || !strlen(name)) 1056 return 0; 1057 return !is_mapping_symbol(name); 1058 } 1059 1060 /* Look up the nearest symbol based on the section and the address */ 1061 static Elf_Sym *find_nearest_sym(struct elf_info *elf, Elf_Addr addr, 1062 unsigned int secndx, bool allow_negative, 1063 Elf_Addr min_distance) 1064 { 1065 Elf_Sym *sym; 1066 Elf_Sym *near = NULL; 1067 Elf_Addr sym_addr, distance; 1068 bool is_arm = (elf->hdr->e_machine == EM_ARM); 1069 1070 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1071 if (get_secindex(elf, sym) != secndx) 1072 continue; 1073 if (!is_valid_name(elf, sym)) 1074 continue; 1075 1076 sym_addr = sym->st_value; 1077 1078 /* 1079 * For ARM Thumb instruction, the bit 0 of st_value is set 1080 * if the symbol is STT_FUNC type. Mask it to get the address. 1081 */ 1082 if (is_arm && ELF_ST_TYPE(sym->st_info) == STT_FUNC) 1083 sym_addr &= ~1; 1084 1085 if (addr >= sym_addr) 1086 distance = addr - sym_addr; 1087 else if (allow_negative) 1088 distance = sym_addr - addr; 1089 else 1090 continue; 1091 1092 if (distance <= min_distance) { 1093 min_distance = distance; 1094 near = sym; 1095 } 1096 1097 if (min_distance == 0) 1098 break; 1099 } 1100 return near; 1101 } 1102 1103 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 1104 unsigned int secndx) 1105 { 1106 return find_nearest_sym(elf, addr, secndx, false, ~0); 1107 } 1108 1109 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 1110 { 1111 /* If the supplied symbol has a valid name, return it */ 1112 if (is_valid_name(elf, sym)) 1113 return sym; 1114 1115 /* 1116 * Strive to find a better symbol name, but the resulting name may not 1117 * match the symbol referenced in the original code. 1118 */ 1119 return find_nearest_sym(elf, addr, get_secindex(elf, sym), true, 20); 1120 } 1121 1122 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1123 { 1124 if (secndx >= elf->num_sections) 1125 return false; 1126 1127 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1128 } 1129 1130 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1131 const struct sectioncheck* const mismatch, 1132 Elf_Sym *tsym, 1133 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1134 const char *tosec, Elf_Addr taddr) 1135 { 1136 Elf_Sym *from; 1137 const char *tosym; 1138 const char *fromsym; 1139 1140 from = find_fromsym(elf, faddr, fsecndx); 1141 fromsym = sym_name(elf, from); 1142 1143 tsym = find_tosym(elf, taddr, tsym); 1144 tosym = sym_name(elf, tsym); 1145 1146 /* check whitelist - we may ignore it */ 1147 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1148 return; 1149 1150 sec_mismatch_count++; 1151 1152 warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n", 1153 modname, fromsym, (unsigned int)(faddr - from->st_value), fromsec, tosym, tosec); 1154 1155 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1156 if (match(tosec, mismatch->bad_tosec)) 1157 fatal("The relocation at %s+0x%lx references\n" 1158 "section \"%s\" which is black-listed.\n" 1159 "Something is seriously wrong and should be fixed.\n" 1160 "You might get more information about where this is\n" 1161 "coming from by using scripts/check_extable.sh %s\n", 1162 fromsec, (long)faddr, tosec, modname); 1163 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1164 warn("The relocation at %s+0x%lx references\n" 1165 "section \"%s\" which is not in the list of\n" 1166 "authorized sections. If you're adding a new section\n" 1167 "and/or if this reference is valid, add \"%s\" to the\n" 1168 "list of authorized sections to jump to on fault.\n" 1169 "This can be achieved by adding \"%s\" to\n" 1170 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1171 fromsec, (long)faddr, tosec, tosec, tosec); 1172 else 1173 error("%s+0x%lx references non-executable section '%s'\n", 1174 fromsec, (long)faddr, tosec); 1175 } 1176 } 1177 1178 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1179 Elf_Addr faddr, const char *secname, 1180 Elf_Sym *sym) 1181 { 1182 static const char *prefix = "__export_symbol_"; 1183 const char *label_name, *name, *data; 1184 Elf_Sym *label; 1185 struct symbol *s; 1186 bool is_gpl; 1187 1188 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1189 label_name = sym_name(elf, label); 1190 1191 if (!strstarts(label_name, prefix)) { 1192 error("%s: .export_symbol section contains strange symbol '%s'\n", 1193 mod->name, label_name); 1194 return; 1195 } 1196 1197 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1198 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1199 error("%s: local symbol '%s' was exported\n", mod->name, 1200 label_name + strlen(prefix)); 1201 return; 1202 } 1203 1204 name = sym_name(elf, sym); 1205 if (strcmp(label_name + strlen(prefix), name)) { 1206 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1207 mod->name, name); 1208 return; 1209 } 1210 1211 data = sym_get_data(elf, label); /* license */ 1212 if (!strcmp(data, "GPL")) { 1213 is_gpl = true; 1214 } else if (!strcmp(data, "")) { 1215 is_gpl = false; 1216 } else { 1217 error("%s: unknown license '%s' was specified for '%s'\n", 1218 mod->name, data, name); 1219 return; 1220 } 1221 1222 data += strlen(data) + 1; /* namespace */ 1223 s = sym_add_exported(name, mod, is_gpl, data); 1224 1225 /* 1226 * We need to be aware whether we are exporting a function or 1227 * a data on some architectures. 1228 */ 1229 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1230 1231 if (match(secname, PATTERNS(INIT_SECTIONS))) 1232 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1233 mod->name, name); 1234 else if (match(secname, PATTERNS(EXIT_SECTIONS))) 1235 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1236 mod->name, name); 1237 } 1238 1239 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1240 Elf_Sym *sym, 1241 unsigned int fsecndx, const char *fromsec, 1242 Elf_Addr faddr, Elf_Addr taddr) 1243 { 1244 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1245 const struct sectioncheck *mismatch; 1246 1247 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1248 check_export_symbol(mod, elf, faddr, tosec, sym); 1249 return; 1250 } 1251 1252 mismatch = section_mismatch(fromsec, tosec); 1253 if (!mismatch) 1254 return; 1255 1256 default_mismatch_handler(mod->name, elf, mismatch, sym, 1257 fsecndx, fromsec, faddr, 1258 tosec, taddr); 1259 } 1260 1261 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1262 { 1263 switch (r_type) { 1264 case R_386_32: 1265 return TO_NATIVE(*location); 1266 case R_386_PC32: 1267 return TO_NATIVE(*location) + 4; 1268 } 1269 1270 return (Elf_Addr)(-1); 1271 } 1272 1273 #ifndef R_ARM_CALL 1274 #define R_ARM_CALL 28 1275 #endif 1276 #ifndef R_ARM_JUMP24 1277 #define R_ARM_JUMP24 29 1278 #endif 1279 1280 #ifndef R_ARM_THM_CALL 1281 #define R_ARM_THM_CALL 10 1282 #endif 1283 #ifndef R_ARM_THM_JUMP24 1284 #define R_ARM_THM_JUMP24 30 1285 #endif 1286 1287 #ifndef R_ARM_MOVW_ABS_NC 1288 #define R_ARM_MOVW_ABS_NC 43 1289 #endif 1290 1291 #ifndef R_ARM_MOVT_ABS 1292 #define R_ARM_MOVT_ABS 44 1293 #endif 1294 1295 #ifndef R_ARM_THM_MOVW_ABS_NC 1296 #define R_ARM_THM_MOVW_ABS_NC 47 1297 #endif 1298 1299 #ifndef R_ARM_THM_MOVT_ABS 1300 #define R_ARM_THM_MOVT_ABS 48 1301 #endif 1302 1303 #ifndef R_ARM_THM_JUMP19 1304 #define R_ARM_THM_JUMP19 51 1305 #endif 1306 1307 static int32_t sign_extend32(int32_t value, int index) 1308 { 1309 uint8_t shift = 31 - index; 1310 1311 return (int32_t)(value << shift) >> shift; 1312 } 1313 1314 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1315 { 1316 uint32_t inst, upper, lower, sign, j1, j2; 1317 int32_t offset; 1318 1319 switch (r_type) { 1320 case R_ARM_ABS32: 1321 case R_ARM_REL32: 1322 inst = TO_NATIVE(*(uint32_t *)loc); 1323 return inst + sym->st_value; 1324 case R_ARM_MOVW_ABS_NC: 1325 case R_ARM_MOVT_ABS: 1326 inst = TO_NATIVE(*(uint32_t *)loc); 1327 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1328 15); 1329 return offset + sym->st_value; 1330 case R_ARM_PC24: 1331 case R_ARM_CALL: 1332 case R_ARM_JUMP24: 1333 inst = TO_NATIVE(*(uint32_t *)loc); 1334 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1335 return offset + sym->st_value + 8; 1336 case R_ARM_THM_MOVW_ABS_NC: 1337 case R_ARM_THM_MOVT_ABS: 1338 upper = TO_NATIVE(*(uint16_t *)loc); 1339 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1340 offset = sign_extend32(((upper & 0x000f) << 12) | 1341 ((upper & 0x0400) << 1) | 1342 ((lower & 0x7000) >> 4) | 1343 (lower & 0x00ff), 1344 15); 1345 return offset + sym->st_value; 1346 case R_ARM_THM_JUMP19: 1347 /* 1348 * Encoding T3: 1349 * S = upper[10] 1350 * imm6 = upper[5:0] 1351 * J1 = lower[13] 1352 * J2 = lower[11] 1353 * imm11 = lower[10:0] 1354 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1355 */ 1356 upper = TO_NATIVE(*(uint16_t *)loc); 1357 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1358 1359 sign = (upper >> 10) & 1; 1360 j1 = (lower >> 13) & 1; 1361 j2 = (lower >> 11) & 1; 1362 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1363 ((upper & 0x03f) << 12) | 1364 ((lower & 0x07ff) << 1), 1365 20); 1366 return offset + sym->st_value + 4; 1367 case R_ARM_THM_CALL: 1368 case R_ARM_THM_JUMP24: 1369 /* 1370 * Encoding T4: 1371 * S = upper[10] 1372 * imm10 = upper[9:0] 1373 * J1 = lower[13] 1374 * J2 = lower[11] 1375 * imm11 = lower[10:0] 1376 * I1 = NOT(J1 XOR S) 1377 * I2 = NOT(J2 XOR S) 1378 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1379 */ 1380 upper = TO_NATIVE(*(uint16_t *)loc); 1381 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1382 1383 sign = (upper >> 10) & 1; 1384 j1 = (lower >> 13) & 1; 1385 j2 = (lower >> 11) & 1; 1386 offset = sign_extend32((sign << 24) | 1387 ((~(j1 ^ sign) & 1) << 23) | 1388 ((~(j2 ^ sign) & 1) << 22) | 1389 ((upper & 0x03ff) << 12) | 1390 ((lower & 0x07ff) << 1), 1391 24); 1392 return offset + sym->st_value + 4; 1393 } 1394 1395 return (Elf_Addr)(-1); 1396 } 1397 1398 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1399 { 1400 uint32_t inst; 1401 1402 inst = TO_NATIVE(*location); 1403 switch (r_type) { 1404 case R_MIPS_LO16: 1405 return inst & 0xffff; 1406 case R_MIPS_26: 1407 return (inst & 0x03ffffff) << 2; 1408 case R_MIPS_32: 1409 return inst; 1410 } 1411 return (Elf_Addr)(-1); 1412 } 1413 1414 #ifndef EM_RISCV 1415 #define EM_RISCV 243 1416 #endif 1417 1418 #ifndef R_RISCV_SUB32 1419 #define R_RISCV_SUB32 39 1420 #endif 1421 1422 #ifndef EM_LOONGARCH 1423 #define EM_LOONGARCH 258 1424 #endif 1425 1426 #ifndef R_LARCH_SUB32 1427 #define R_LARCH_SUB32 55 1428 #endif 1429 1430 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1431 unsigned int *r_type, unsigned int *r_sym) 1432 { 1433 typedef struct { 1434 Elf64_Word r_sym; /* Symbol index */ 1435 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1436 unsigned char r_type3; /* 3rd relocation type */ 1437 unsigned char r_type2; /* 2nd relocation type */ 1438 unsigned char r_type; /* 1st relocation type */ 1439 } Elf64_Mips_R_Info; 1440 1441 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1442 1443 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1444 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1445 1446 *r_type = mips64_r_info->r_type; 1447 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1448 return; 1449 } 1450 1451 if (is_64bit) { 1452 Elf64_Xword r_info64 = r_info; 1453 1454 r_info = TO_NATIVE(r_info64); 1455 } else { 1456 Elf32_Word r_info32 = r_info; 1457 1458 r_info = TO_NATIVE(r_info32); 1459 } 1460 1461 *r_type = ELF_R_TYPE(r_info); 1462 *r_sym = ELF_R_SYM(r_info); 1463 } 1464 1465 static void section_rela(struct module *mod, struct elf_info *elf, 1466 Elf_Shdr *sechdr) 1467 { 1468 Elf_Rela *rela; 1469 unsigned int fsecndx = sechdr->sh_info; 1470 const char *fromsec = sec_name(elf, fsecndx); 1471 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; 1472 Elf_Rela *stop = (void *)start + sechdr->sh_size; 1473 1474 /* if from section (name) is know good then skip it */ 1475 if (match(fromsec, section_white_list)) 1476 return; 1477 1478 for (rela = start; rela < stop; rela++) { 1479 Elf_Addr taddr, r_offset; 1480 unsigned int r_type, r_sym; 1481 1482 r_offset = TO_NATIVE(rela->r_offset); 1483 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1484 1485 taddr = TO_NATIVE(rela->r_addend); 1486 1487 switch (elf->hdr->e_machine) { 1488 case EM_RISCV: 1489 if (!strcmp("__ex_table", fromsec) && 1490 r_type == R_RISCV_SUB32) 1491 continue; 1492 break; 1493 case EM_LOONGARCH: 1494 if (!strcmp("__ex_table", fromsec) && 1495 r_type == R_LARCH_SUB32) 1496 continue; 1497 break; 1498 } 1499 1500 check_section_mismatch(mod, elf, elf->symtab_start + r_sym, 1501 fsecndx, fromsec, r_offset, taddr); 1502 } 1503 } 1504 1505 static void section_rel(struct module *mod, struct elf_info *elf, 1506 Elf_Shdr *sechdr) 1507 { 1508 Elf_Rel *rel; 1509 unsigned int fsecndx = sechdr->sh_info; 1510 const char *fromsec = sec_name(elf, fsecndx); 1511 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset; 1512 Elf_Rel *stop = (void *)start + sechdr->sh_size; 1513 1514 /* if from section (name) is know good then skip it */ 1515 if (match(fromsec, section_white_list)) 1516 return; 1517 1518 for (rel = start; rel < stop; rel++) { 1519 Elf_Sym *tsym; 1520 Elf_Addr taddr = 0, r_offset; 1521 unsigned int r_type, r_sym; 1522 void *loc; 1523 1524 r_offset = TO_NATIVE(rel->r_offset); 1525 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1526 1527 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1528 tsym = elf->symtab_start + r_sym; 1529 1530 switch (elf->hdr->e_machine) { 1531 case EM_386: 1532 taddr = addend_386_rel(loc, r_type); 1533 break; 1534 case EM_ARM: 1535 taddr = addend_arm_rel(loc, tsym, r_type); 1536 break; 1537 case EM_MIPS: 1538 taddr = addend_mips_rel(loc, r_type); 1539 break; 1540 default: 1541 fatal("Please add code to calculate addend for this architecture\n"); 1542 } 1543 1544 check_section_mismatch(mod, elf, tsym, 1545 fsecndx, fromsec, r_offset, taddr); 1546 } 1547 } 1548 1549 /** 1550 * A module includes a number of sections that are discarded 1551 * either when loaded or when used as built-in. 1552 * For loaded modules all functions marked __init and all data 1553 * marked __initdata will be discarded when the module has been initialized. 1554 * Likewise for modules used built-in the sections marked __exit 1555 * are discarded because __exit marked function are supposed to be called 1556 * only when a module is unloaded which never happens for built-in modules. 1557 * The check_sec_ref() function traverses all relocation records 1558 * to find all references to a section that reference a section that will 1559 * be discarded and warns about it. 1560 **/ 1561 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1562 { 1563 int i; 1564 Elf_Shdr *sechdrs = elf->sechdrs; 1565 1566 /* Walk through all sections */ 1567 for (i = 0; i < elf->num_sections; i++) { 1568 check_section(mod->name, elf, &elf->sechdrs[i]); 1569 /* We want to process only relocation sections and not .init */ 1570 if (sechdrs[i].sh_type == SHT_RELA) 1571 section_rela(mod, elf, &elf->sechdrs[i]); 1572 else if (sechdrs[i].sh_type == SHT_REL) 1573 section_rel(mod, elf, &elf->sechdrs[i]); 1574 } 1575 } 1576 1577 static char *remove_dot(char *s) 1578 { 1579 size_t n = strcspn(s, "."); 1580 1581 if (n && s[n]) { 1582 size_t m = strspn(s + n + 1, "0123456789"); 1583 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1584 s[n] = 0; 1585 } 1586 return s; 1587 } 1588 1589 /* 1590 * The CRCs are recorded in .*.cmd files in the form of: 1591 * #SYMVER <name> <crc> 1592 */ 1593 static void extract_crcs_for_object(const char *object, struct module *mod) 1594 { 1595 char cmd_file[PATH_MAX]; 1596 char *buf, *p; 1597 const char *base; 1598 int dirlen, ret; 1599 1600 base = strrchr(object, '/'); 1601 if (base) { 1602 base++; 1603 dirlen = base - object; 1604 } else { 1605 dirlen = 0; 1606 base = object; 1607 } 1608 1609 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1610 dirlen, object, base); 1611 if (ret >= sizeof(cmd_file)) { 1612 error("%s: too long path was truncated\n", cmd_file); 1613 return; 1614 } 1615 1616 buf = read_text_file(cmd_file); 1617 p = buf; 1618 1619 while ((p = strstr(p, "\n#SYMVER "))) { 1620 char *name; 1621 size_t namelen; 1622 unsigned int crc; 1623 struct symbol *sym; 1624 1625 name = p + strlen("\n#SYMVER "); 1626 1627 p = strchr(name, ' '); 1628 if (!p) 1629 break; 1630 1631 namelen = p - name; 1632 p++; 1633 1634 if (!isdigit(*p)) 1635 continue; /* skip this line */ 1636 1637 crc = strtoul(p, &p, 0); 1638 if (*p != '\n') 1639 continue; /* skip this line */ 1640 1641 name[namelen] = '\0'; 1642 1643 /* 1644 * sym_find_with_module() may return NULL here. 1645 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1646 * Since commit e1327a127703, genksyms calculates CRCs of all 1647 * symbols, including trimmed ones. Ignore orphan CRCs. 1648 */ 1649 sym = sym_find_with_module(name, mod); 1650 if (sym) 1651 sym_set_crc(sym, crc); 1652 } 1653 1654 free(buf); 1655 } 1656 1657 /* 1658 * The symbol versions (CRC) are recorded in the .*.cmd files. 1659 * Parse them to retrieve CRCs for the current module. 1660 */ 1661 static void mod_set_crcs(struct module *mod) 1662 { 1663 char objlist[PATH_MAX]; 1664 char *buf, *p, *obj; 1665 int ret; 1666 1667 if (mod->is_vmlinux) { 1668 strcpy(objlist, ".vmlinux.objs"); 1669 } else { 1670 /* objects for a module are listed in the *.mod file. */ 1671 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1672 if (ret >= sizeof(objlist)) { 1673 error("%s: too long path was truncated\n", objlist); 1674 return; 1675 } 1676 } 1677 1678 buf = read_text_file(objlist); 1679 p = buf; 1680 1681 while ((obj = strsep(&p, "\n")) && obj[0]) 1682 extract_crcs_for_object(obj, mod); 1683 1684 free(buf); 1685 } 1686 1687 static void read_symbols(const char *modname) 1688 { 1689 const char *symname; 1690 char *version; 1691 char *license; 1692 char *namespace; 1693 struct module *mod; 1694 struct elf_info info = { }; 1695 Elf_Sym *sym; 1696 1697 if (!parse_elf(&info, modname)) 1698 return; 1699 1700 if (!strends(modname, ".o")) { 1701 error("%s: filename must be suffixed with .o\n", modname); 1702 return; 1703 } 1704 1705 /* strip trailing .o */ 1706 mod = new_module(modname, strlen(modname) - strlen(".o")); 1707 1708 if (!mod->is_vmlinux) { 1709 license = get_modinfo(&info, "license"); 1710 if (!license) 1711 error("missing MODULE_LICENSE() in %s\n", modname); 1712 while (license) { 1713 if (!license_is_gpl_compatible(license)) { 1714 mod->is_gpl_compatible = false; 1715 break; 1716 } 1717 license = get_next_modinfo(&info, "license", license); 1718 } 1719 1720 namespace = get_modinfo(&info, "import_ns"); 1721 while (namespace) { 1722 add_namespace(&mod->imported_namespaces, namespace); 1723 namespace = get_next_modinfo(&info, "import_ns", 1724 namespace); 1725 } 1726 } 1727 1728 if (extra_warn && !get_modinfo(&info, "description")) 1729 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1730 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1731 symname = remove_dot(info.strtab + sym->st_name); 1732 1733 handle_symbol(mod, &info, sym, symname); 1734 handle_moddevtable(mod, &info, sym, symname); 1735 } 1736 1737 check_sec_ref(mod, &info); 1738 1739 if (!mod->is_vmlinux) { 1740 version = get_modinfo(&info, "version"); 1741 if (version || all_versions) 1742 get_src_version(mod->name, mod->srcversion, 1743 sizeof(mod->srcversion) - 1); 1744 } 1745 1746 parse_elf_finish(&info); 1747 1748 if (modversions) { 1749 /* 1750 * Our trick to get versioning for module struct etc. - it's 1751 * never passed as an argument to an exported function, so 1752 * the automatic versioning doesn't pick it up, but it's really 1753 * important anyhow. 1754 */ 1755 sym_add_unresolved("module_layout", mod, false); 1756 1757 mod_set_crcs(mod); 1758 } 1759 } 1760 1761 static void read_symbols_from_files(const char *filename) 1762 { 1763 FILE *in = stdin; 1764 char fname[PATH_MAX]; 1765 1766 in = fopen(filename, "r"); 1767 if (!in) 1768 fatal("Can't open filenames file %s: %m", filename); 1769 1770 while (fgets(fname, PATH_MAX, in) != NULL) { 1771 if (strends(fname, "\n")) 1772 fname[strlen(fname)-1] = '\0'; 1773 read_symbols(fname); 1774 } 1775 1776 fclose(in); 1777 } 1778 1779 #define SZ 500 1780 1781 /* We first write the generated file into memory using the 1782 * following helper, then compare to the file on disk and 1783 * only update the later if anything changed */ 1784 1785 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1786 const char *fmt, ...) 1787 { 1788 char tmp[SZ]; 1789 int len; 1790 va_list ap; 1791 1792 va_start(ap, fmt); 1793 len = vsnprintf(tmp, SZ, fmt, ap); 1794 buf_write(buf, tmp, len); 1795 va_end(ap); 1796 } 1797 1798 void buf_write(struct buffer *buf, const char *s, int len) 1799 { 1800 if (buf->size - buf->pos < len) { 1801 buf->size += len + SZ; 1802 buf->p = NOFAIL(realloc(buf->p, buf->size)); 1803 } 1804 strncpy(buf->p + buf->pos, s, len); 1805 buf->pos += len; 1806 } 1807 1808 static void check_exports(struct module *mod) 1809 { 1810 struct symbol *s, *exp; 1811 1812 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1813 const char *basename; 1814 exp = find_symbol(s->name); 1815 if (!exp) { 1816 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1817 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, 1818 "\"%s\" [%s.ko] undefined!\n", 1819 s->name, mod->name); 1820 continue; 1821 } 1822 if (exp->module == mod) { 1823 error("\"%s\" [%s.ko] was exported without definition\n", 1824 s->name, mod->name); 1825 continue; 1826 } 1827 1828 exp->used = true; 1829 s->module = exp->module; 1830 s->crc_valid = exp->crc_valid; 1831 s->crc = exp->crc; 1832 1833 basename = strrchr(mod->name, '/'); 1834 if (basename) 1835 basename++; 1836 else 1837 basename = mod->name; 1838 1839 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1840 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, 1841 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1842 basename, exp->name, exp->namespace); 1843 add_namespace(&mod->missing_namespaces, exp->namespace); 1844 } 1845 1846 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1847 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1848 basename, exp->name); 1849 } 1850 } 1851 1852 static void handle_white_list_exports(const char *white_list) 1853 { 1854 char *buf, *p, *name; 1855 1856 buf = read_text_file(white_list); 1857 p = buf; 1858 1859 while ((name = strsep(&p, "\n"))) { 1860 struct symbol *sym = find_symbol(name); 1861 1862 if (sym) 1863 sym->used = true; 1864 } 1865 1866 free(buf); 1867 } 1868 1869 static void check_modname_len(struct module *mod) 1870 { 1871 const char *mod_name; 1872 1873 mod_name = strrchr(mod->name, '/'); 1874 if (mod_name == NULL) 1875 mod_name = mod->name; 1876 else 1877 mod_name++; 1878 if (strlen(mod_name) >= MODULE_NAME_LEN) 1879 error("module name is too long [%s.ko]\n", mod->name); 1880 } 1881 1882 /** 1883 * Header for the generated file 1884 **/ 1885 static void add_header(struct buffer *b, struct module *mod) 1886 { 1887 buf_printf(b, "#include <linux/module.h>\n"); 1888 /* 1889 * Include build-salt.h after module.h in order to 1890 * inherit the definitions. 1891 */ 1892 buf_printf(b, "#define INCLUDE_VERMAGIC\n"); 1893 buf_printf(b, "#include <linux/build-salt.h>\n"); 1894 buf_printf(b, "#include <linux/elfnote-lto.h>\n"); 1895 buf_printf(b, "#include <linux/export-internal.h>\n"); 1896 buf_printf(b, "#include <linux/vermagic.h>\n"); 1897 buf_printf(b, "#include <linux/compiler.h>\n"); 1898 buf_printf(b, "\n"); 1899 buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n"); 1900 buf_printf(b, "#include <asm/orc_header.h>\n"); 1901 buf_printf(b, "ORC_HEADER;\n"); 1902 buf_printf(b, "#endif\n"); 1903 buf_printf(b, "\n"); 1904 buf_printf(b, "BUILD_SALT;\n"); 1905 buf_printf(b, "BUILD_LTO_INFO;\n"); 1906 buf_printf(b, "\n"); 1907 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1908 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1909 buf_printf(b, "\n"); 1910 buf_printf(b, "__visible struct module __this_module\n"); 1911 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1912 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1913 if (mod->has_init) 1914 buf_printf(b, "\t.init = init_module,\n"); 1915 if (mod->has_cleanup) 1916 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1917 "\t.exit = cleanup_module,\n" 1918 "#endif\n"); 1919 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1920 buf_printf(b, "};\n"); 1921 1922 if (!external_module) 1923 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1924 1925 buf_printf(b, 1926 "\n" 1927 "#ifdef CONFIG_RETPOLINE\n" 1928 "MODULE_INFO(retpoline, \"Y\");\n" 1929 "#endif\n"); 1930 1931 if (strstarts(mod->name, "drivers/staging")) 1932 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1933 1934 if (strstarts(mod->name, "tools/testing")) 1935 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1936 } 1937 1938 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1939 { 1940 struct symbol *sym; 1941 1942 /* generate struct for exported symbols */ 1943 buf_printf(buf, "\n"); 1944 list_for_each_entry(sym, &mod->exported_symbols, list) { 1945 if (trim_unused_exports && !sym->used) 1946 continue; 1947 1948 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1949 sym->is_func ? "FUNC" : "DATA", sym->name, 1950 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1951 } 1952 1953 if (!modversions) 1954 return; 1955 1956 /* record CRCs for exported symbols */ 1957 buf_printf(buf, "\n"); 1958 list_for_each_entry(sym, &mod->exported_symbols, list) { 1959 if (trim_unused_exports && !sym->used) 1960 continue; 1961 1962 if (!sym->crc_valid) 1963 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1964 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1965 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1966 sym->name); 1967 1968 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1969 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1970 } 1971 } 1972 1973 /** 1974 * Record CRCs for unresolved symbols 1975 **/ 1976 static void add_versions(struct buffer *b, struct module *mod) 1977 { 1978 struct symbol *s; 1979 1980 if (!modversions) 1981 return; 1982 1983 buf_printf(b, "\n"); 1984 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1985 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1986 1987 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1988 if (!s->module) 1989 continue; 1990 if (!s->crc_valid) { 1991 warn("\"%s\" [%s.ko] has no CRC!\n", 1992 s->name, mod->name); 1993 continue; 1994 } 1995 if (strlen(s->name) >= MODULE_NAME_LEN) { 1996 error("too long symbol \"%s\" [%s.ko]\n", 1997 s->name, mod->name); 1998 break; 1999 } 2000 buf_printf(b, "\t{ %#8x, \"%s\" },\n", 2001 s->crc, s->name); 2002 } 2003 2004 buf_printf(b, "};\n"); 2005 } 2006 2007 static void add_depends(struct buffer *b, struct module *mod) 2008 { 2009 struct symbol *s; 2010 int first = 1; 2011 2012 /* Clear ->seen flag of modules that own symbols needed by this. */ 2013 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2014 if (s->module) 2015 s->module->seen = s->module->is_vmlinux; 2016 } 2017 2018 buf_printf(b, "\n"); 2019 buf_printf(b, "MODULE_INFO(depends, \""); 2020 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2021 const char *p; 2022 if (!s->module) 2023 continue; 2024 2025 if (s->module->seen) 2026 continue; 2027 2028 s->module->seen = true; 2029 p = strrchr(s->module->name, '/'); 2030 if (p) 2031 p++; 2032 else 2033 p = s->module->name; 2034 buf_printf(b, "%s%s", first ? "" : ",", p); 2035 first = 0; 2036 } 2037 buf_printf(b, "\");\n"); 2038 } 2039 2040 static void add_srcversion(struct buffer *b, struct module *mod) 2041 { 2042 if (mod->srcversion[0]) { 2043 buf_printf(b, "\n"); 2044 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 2045 mod->srcversion); 2046 } 2047 } 2048 2049 static void write_buf(struct buffer *b, const char *fname) 2050 { 2051 FILE *file; 2052 2053 if (error_occurred) 2054 return; 2055 2056 file = fopen(fname, "w"); 2057 if (!file) { 2058 perror(fname); 2059 exit(1); 2060 } 2061 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2062 perror(fname); 2063 exit(1); 2064 } 2065 if (fclose(file) != 0) { 2066 perror(fname); 2067 exit(1); 2068 } 2069 } 2070 2071 static void write_if_changed(struct buffer *b, const char *fname) 2072 { 2073 char *tmp; 2074 FILE *file; 2075 struct stat st; 2076 2077 file = fopen(fname, "r"); 2078 if (!file) 2079 goto write; 2080 2081 if (fstat(fileno(file), &st) < 0) 2082 goto close_write; 2083 2084 if (st.st_size != b->pos) 2085 goto close_write; 2086 2087 tmp = NOFAIL(malloc(b->pos)); 2088 if (fread(tmp, 1, b->pos, file) != b->pos) 2089 goto free_write; 2090 2091 if (memcmp(tmp, b->p, b->pos) != 0) 2092 goto free_write; 2093 2094 free(tmp); 2095 fclose(file); 2096 return; 2097 2098 free_write: 2099 free(tmp); 2100 close_write: 2101 fclose(file); 2102 write: 2103 write_buf(b, fname); 2104 } 2105 2106 static void write_vmlinux_export_c_file(struct module *mod) 2107 { 2108 struct buffer buf = { }; 2109 2110 buf_printf(&buf, 2111 "#include <linux/export-internal.h>\n"); 2112 2113 add_exported_symbols(&buf, mod); 2114 write_if_changed(&buf, ".vmlinux.export.c"); 2115 free(buf.p); 2116 } 2117 2118 /* do sanity checks, and generate *.mod.c file */ 2119 static void write_mod_c_file(struct module *mod) 2120 { 2121 struct buffer buf = { }; 2122 char fname[PATH_MAX]; 2123 int ret; 2124 2125 add_header(&buf, mod); 2126 add_exported_symbols(&buf, mod); 2127 add_versions(&buf, mod); 2128 add_depends(&buf, mod); 2129 add_moddevtable(&buf, mod); 2130 add_srcversion(&buf, mod); 2131 2132 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2133 if (ret >= sizeof(fname)) { 2134 error("%s: too long path was truncated\n", fname); 2135 goto free; 2136 } 2137 2138 write_if_changed(&buf, fname); 2139 2140 free: 2141 free(buf.p); 2142 } 2143 2144 /* parse Module.symvers file. line format: 2145 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2146 **/ 2147 static void read_dump(const char *fname) 2148 { 2149 char *buf, *pos, *line; 2150 2151 buf = read_text_file(fname); 2152 if (!buf) 2153 /* No symbol versions, silently ignore */ 2154 return; 2155 2156 pos = buf; 2157 2158 while ((line = get_line(&pos))) { 2159 char *symname, *namespace, *modname, *d, *export; 2160 unsigned int crc; 2161 struct module *mod; 2162 struct symbol *s; 2163 bool gpl_only; 2164 2165 if (!(symname = strchr(line, '\t'))) 2166 goto fail; 2167 *symname++ = '\0'; 2168 if (!(modname = strchr(symname, '\t'))) 2169 goto fail; 2170 *modname++ = '\0'; 2171 if (!(export = strchr(modname, '\t'))) 2172 goto fail; 2173 *export++ = '\0'; 2174 if (!(namespace = strchr(export, '\t'))) 2175 goto fail; 2176 *namespace++ = '\0'; 2177 2178 crc = strtoul(line, &d, 16); 2179 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2180 goto fail; 2181 2182 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2183 gpl_only = true; 2184 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2185 gpl_only = false; 2186 } else { 2187 error("%s: unknown license %s. skip", symname, export); 2188 continue; 2189 } 2190 2191 mod = find_module(modname); 2192 if (!mod) { 2193 mod = new_module(modname, strlen(modname)); 2194 mod->from_dump = true; 2195 } 2196 s = sym_add_exported(symname, mod, gpl_only, namespace); 2197 sym_set_crc(s, crc); 2198 } 2199 free(buf); 2200 return; 2201 fail: 2202 free(buf); 2203 fatal("parse error in symbol dump file\n"); 2204 } 2205 2206 static void write_dump(const char *fname) 2207 { 2208 struct buffer buf = { }; 2209 struct module *mod; 2210 struct symbol *sym; 2211 2212 list_for_each_entry(mod, &modules, list) { 2213 if (mod->from_dump) 2214 continue; 2215 list_for_each_entry(sym, &mod->exported_symbols, list) { 2216 if (trim_unused_exports && !sym->used) 2217 continue; 2218 2219 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2220 sym->crc, sym->name, mod->name, 2221 sym->is_gpl_only ? "_GPL" : "", 2222 sym->namespace); 2223 } 2224 } 2225 write_buf(&buf, fname); 2226 free(buf.p); 2227 } 2228 2229 static void write_namespace_deps_files(const char *fname) 2230 { 2231 struct module *mod; 2232 struct namespace_list *ns; 2233 struct buffer ns_deps_buf = {}; 2234 2235 list_for_each_entry(mod, &modules, list) { 2236 2237 if (mod->from_dump || list_empty(&mod->missing_namespaces)) 2238 continue; 2239 2240 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2241 2242 list_for_each_entry(ns, &mod->missing_namespaces, list) 2243 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2244 2245 buf_printf(&ns_deps_buf, "\n"); 2246 } 2247 2248 write_if_changed(&ns_deps_buf, fname); 2249 free(ns_deps_buf.p); 2250 } 2251 2252 struct dump_list { 2253 struct list_head list; 2254 const char *file; 2255 }; 2256 2257 int main(int argc, char **argv) 2258 { 2259 struct module *mod; 2260 char *missing_namespace_deps = NULL; 2261 char *unused_exports_white_list = NULL; 2262 char *dump_write = NULL, *files_source = NULL; 2263 int opt; 2264 LIST_HEAD(dump_lists); 2265 struct dump_list *dl, *dl2; 2266 2267 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) { 2268 switch (opt) { 2269 case 'e': 2270 external_module = true; 2271 break; 2272 case 'i': 2273 dl = NOFAIL(malloc(sizeof(*dl))); 2274 dl->file = optarg; 2275 list_add_tail(&dl->list, &dump_lists); 2276 break; 2277 case 'M': 2278 module_enabled = true; 2279 break; 2280 case 'm': 2281 modversions = true; 2282 break; 2283 case 'n': 2284 ignore_missing_files = true; 2285 break; 2286 case 'o': 2287 dump_write = optarg; 2288 break; 2289 case 'a': 2290 all_versions = true; 2291 break; 2292 case 'T': 2293 files_source = optarg; 2294 break; 2295 case 't': 2296 trim_unused_exports = true; 2297 break; 2298 case 'u': 2299 unused_exports_white_list = optarg; 2300 break; 2301 case 'W': 2302 extra_warn = true; 2303 break; 2304 case 'w': 2305 warn_unresolved = true; 2306 break; 2307 case 'E': 2308 sec_mismatch_warn_only = false; 2309 break; 2310 case 'N': 2311 allow_missing_ns_imports = true; 2312 break; 2313 case 'd': 2314 missing_namespace_deps = optarg; 2315 break; 2316 default: 2317 exit(1); 2318 } 2319 } 2320 2321 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2322 read_dump(dl->file); 2323 list_del(&dl->list); 2324 free(dl); 2325 } 2326 2327 while (optind < argc) 2328 read_symbols(argv[optind++]); 2329 2330 if (files_source) 2331 read_symbols_from_files(files_source); 2332 2333 list_for_each_entry(mod, &modules, list) { 2334 if (mod->from_dump || mod->is_vmlinux) 2335 continue; 2336 2337 check_modname_len(mod); 2338 check_exports(mod); 2339 } 2340 2341 if (unused_exports_white_list) 2342 handle_white_list_exports(unused_exports_white_list); 2343 2344 list_for_each_entry(mod, &modules, list) { 2345 if (mod->from_dump) 2346 continue; 2347 2348 if (mod->is_vmlinux) 2349 write_vmlinux_export_c_file(mod); 2350 else 2351 write_mod_c_file(mod); 2352 } 2353 2354 if (missing_namespace_deps) 2355 write_namespace_deps_files(missing_namespace_deps); 2356 2357 if (dump_write) 2358 write_dump(dump_write); 2359 if (sec_mismatch_count && !sec_mismatch_warn_only) 2360 error("Section mismatches detected.\n" 2361 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2362 2363 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2364 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2365 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2366 2367 return error_occurred ? 1 : 0; 2368 } 2369