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 NULL 766 }; 767 768 /* 769 * This is used to find sections missing the SHF_ALLOC flag. 770 * The cause of this is often a section specified in assembler 771 * without "ax" / "aw". 772 */ 773 static void check_section(const char *modname, struct elf_info *elf, 774 Elf_Shdr *sechdr) 775 { 776 const char *sec = sech_name(elf, sechdr); 777 778 if (sechdr->sh_type == SHT_PROGBITS && 779 !(sechdr->sh_flags & SHF_ALLOC) && 780 !match(sec, section_white_list)) { 781 warn("%s (%s): unexpected non-allocatable section.\n" 782 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 783 "Note that for example <linux/init.h> contains\n" 784 "section definitions for use in .S files.\n\n", 785 modname, sec); 786 } 787 } 788 789 790 791 #define ALL_INIT_DATA_SECTIONS \ 792 ".init.setup", ".init.rodata", ".meminit.rodata", \ 793 ".init.data", ".meminit.data" 794 #define ALL_EXIT_DATA_SECTIONS \ 795 ".exit.data", ".memexit.data" 796 797 #define ALL_INIT_TEXT_SECTIONS \ 798 ".init.text", ".meminit.text" 799 #define ALL_EXIT_TEXT_SECTIONS \ 800 ".exit.text", ".memexit.text" 801 802 #define ALL_PCI_INIT_SECTIONS \ 803 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 804 ".pci_fixup_enable", ".pci_fixup_resume", \ 805 ".pci_fixup_resume_early", ".pci_fixup_suspend" 806 807 #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS 808 #define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS 809 810 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 811 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS 812 813 #define DATA_SECTIONS ".data", ".data.rel" 814 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ 815 ".kprobes.text", ".cpuidle.text", ".noinstr.text" 816 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ 817 ".fixup", ".entry.text", ".exception.text", \ 818 ".coldtext", ".softirqentry.text" 819 820 #define INIT_SECTIONS ".init.*" 821 #define MEM_INIT_SECTIONS ".meminit.*" 822 823 #define EXIT_SECTIONS ".exit.*" 824 #define MEM_EXIT_SECTIONS ".memexit.*" 825 826 #define ALL_TEXT_SECTIONS ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \ 827 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 828 829 enum mismatch { 830 TEXT_TO_ANY_INIT, 831 DATA_TO_ANY_INIT, 832 TEXTDATA_TO_ANY_EXIT, 833 XXXINIT_TO_SOME_INIT, 834 XXXEXIT_TO_SOME_EXIT, 835 ANY_INIT_TO_ANY_EXIT, 836 ANY_EXIT_TO_ANY_INIT, 837 EXTABLE_TO_NON_TEXT, 838 }; 839 840 /** 841 * Describe how to match sections on different criteria: 842 * 843 * @fromsec: Array of sections to be matched. 844 * 845 * @bad_tosec: Relocations applied to a section in @fromsec to a section in 846 * this array is forbidden (black-list). Can be empty. 847 * 848 * @good_tosec: Relocations applied to a section in @fromsec must be 849 * targeting sections in this array (white-list). Can be empty. 850 * 851 * @mismatch: Type of mismatch. 852 */ 853 struct sectioncheck { 854 const char *fromsec[20]; 855 const char *bad_tosec[20]; 856 const char *good_tosec[20]; 857 enum mismatch mismatch; 858 }; 859 860 static const struct sectioncheck sectioncheck[] = { 861 /* Do not reference init/exit code/data from 862 * normal code and data 863 */ 864 { 865 .fromsec = { TEXT_SECTIONS, NULL }, 866 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 867 .mismatch = TEXT_TO_ANY_INIT, 868 }, 869 { 870 .fromsec = { DATA_SECTIONS, NULL }, 871 .bad_tosec = { ALL_XXXINIT_SECTIONS, INIT_SECTIONS, NULL }, 872 .mismatch = DATA_TO_ANY_INIT, 873 }, 874 { 875 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 876 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 877 .mismatch = TEXTDATA_TO_ANY_EXIT, 878 }, 879 /* Do not reference init code/data from meminit code/data */ 880 { 881 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 882 .bad_tosec = { INIT_SECTIONS, NULL }, 883 .mismatch = XXXINIT_TO_SOME_INIT, 884 }, 885 /* Do not reference exit code/data from memexit code/data */ 886 { 887 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL }, 888 .bad_tosec = { EXIT_SECTIONS, NULL }, 889 .mismatch = XXXEXIT_TO_SOME_EXIT, 890 }, 891 /* Do not use exit code/data from init code */ 892 { 893 .fromsec = { ALL_INIT_SECTIONS, NULL }, 894 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 895 .mismatch = ANY_INIT_TO_ANY_EXIT, 896 }, 897 /* Do not use init code/data from exit code */ 898 { 899 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 900 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 901 .mismatch = ANY_EXIT_TO_ANY_INIT, 902 }, 903 { 904 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 905 .bad_tosec = { INIT_SECTIONS, NULL }, 906 .mismatch = ANY_INIT_TO_ANY_EXIT, 907 }, 908 { 909 .fromsec = { "__ex_table", NULL }, 910 /* If you're adding any new black-listed sections in here, consider 911 * adding a special 'printer' for them in scripts/check_extable. 912 */ 913 .bad_tosec = { ".altinstr_replacement", NULL }, 914 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 915 .mismatch = EXTABLE_TO_NON_TEXT, 916 } 917 }; 918 919 static const struct sectioncheck *section_mismatch( 920 const char *fromsec, const char *tosec) 921 { 922 int i; 923 924 /* 925 * The target section could be the SHT_NUL section when we're 926 * handling relocations to un-resolved symbols, trying to match it 927 * doesn't make much sense and causes build failures on parisc 928 * architectures. 929 */ 930 if (*tosec == '\0') 931 return NULL; 932 933 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 934 const struct sectioncheck *check = §ioncheck[i]; 935 936 if (match(fromsec, check->fromsec)) { 937 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 938 return check; 939 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 940 return check; 941 } 942 } 943 return NULL; 944 } 945 946 /** 947 * Whitelist to allow certain references to pass with no warning. 948 * 949 * Pattern 1: 950 * If a module parameter is declared __initdata and permissions=0 951 * then this is legal despite the warning generated. 952 * We cannot see value of permissions here, so just ignore 953 * this pattern. 954 * The pattern is identified by: 955 * tosec = .init.data 956 * fromsec = .data* 957 * atsym =__param* 958 * 959 * Pattern 1a: 960 * module_param_call() ops can refer to __init set function if permissions=0 961 * The pattern is identified by: 962 * tosec = .init.text 963 * fromsec = .data* 964 * atsym = __param_ops_* 965 * 966 * Pattern 3: 967 * Whitelist all references from .head.text to any init section 968 * 969 * Pattern 4: 970 * Some symbols belong to init section but still it is ok to reference 971 * these from non-init sections as these symbols don't have any memory 972 * allocated for them and symbol address and value are same. So even 973 * if init section is freed, its ok to reference those symbols. 974 * For ex. symbols marking the init section boundaries. 975 * This pattern is identified by 976 * refsymname = __init_begin, _sinittext, _einittext 977 * 978 * Pattern 5: 979 * GCC may optimize static inlines when fed constant arg(s) resulting 980 * in functions like cpumask_empty() -- generating an associated symbol 981 * cpumask_empty.constprop.3 that appears in the audit. If the const that 982 * is passed in comes from __init, like say nmi_ipi_mask, we get a 983 * meaningless section warning. May need to add isra symbols too... 984 * This pattern is identified by 985 * tosec = init section 986 * fromsec = text section 987 * refsymname = *.constprop.* 988 * 989 **/ 990 static int secref_whitelist(const char *fromsec, const char *fromsym, 991 const char *tosec, const char *tosym) 992 { 993 /* Check for pattern 1 */ 994 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 995 match(fromsec, PATTERNS(DATA_SECTIONS)) && 996 strstarts(fromsym, "__param")) 997 return 0; 998 999 /* Check for pattern 1a */ 1000 if (strcmp(tosec, ".init.text") == 0 && 1001 match(fromsec, PATTERNS(DATA_SECTIONS)) && 1002 strstarts(fromsym, "__param_ops_")) 1003 return 0; 1004 1005 /* symbols in data sections that may refer to any init/exit sections */ 1006 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 1007 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 1008 match(fromsym, PATTERNS("*_template", // scsi uses *_template a lot 1009 "*_timer", // arm uses ops structures named _timer a lot 1010 "*_sht", // scsi also used *_sht to some extent 1011 "*_ops", 1012 "*_probe", 1013 "*_probe_one", 1014 "*_console"))) 1015 return 0; 1016 1017 /* symbols in data sections that may refer to meminit/exit sections */ 1018 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 1019 match(tosec, PATTERNS(ALL_XXXINIT_SECTIONS, ALL_EXIT_SECTIONS)) && 1020 match(fromsym, PATTERNS("*driver"))) 1021 return 0; 1022 1023 /* Check for pattern 3 */ 1024 if (strstarts(fromsec, ".head.text") && 1025 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 1026 return 0; 1027 1028 /* Check for pattern 4 */ 1029 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 1030 return 0; 1031 1032 /* Check for pattern 5 */ 1033 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 1034 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 1035 match(fromsym, PATTERNS("*.constprop.*"))) 1036 return 0; 1037 1038 return 1; 1039 } 1040 1041 /* 1042 * If there's no name there, ignore it; likewise, ignore it if it's 1043 * one of the magic symbols emitted used by current tools. 1044 * 1045 * Otherwise if find_symbols_between() returns those symbols, they'll 1046 * fail the whitelist tests and cause lots of false alarms ... fixable 1047 * only by merging __exit and __init sections into __text, bloating 1048 * the kernel (which is especially evil on embedded platforms). 1049 */ 1050 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 1051 { 1052 const char *name = elf->strtab + sym->st_name; 1053 1054 if (!name || !strlen(name)) 1055 return 0; 1056 return !is_mapping_symbol(name); 1057 } 1058 1059 /* Look up the nearest symbol based on the section and the address */ 1060 static Elf_Sym *find_nearest_sym(struct elf_info *elf, Elf_Addr addr, 1061 unsigned int secndx, bool allow_negative, 1062 Elf_Addr min_distance) 1063 { 1064 Elf_Sym *sym; 1065 Elf_Sym *near = NULL; 1066 Elf_Addr sym_addr, distance; 1067 bool is_arm = (elf->hdr->e_machine == EM_ARM); 1068 1069 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1070 if (get_secindex(elf, sym) != secndx) 1071 continue; 1072 if (!is_valid_name(elf, sym)) 1073 continue; 1074 1075 sym_addr = sym->st_value; 1076 1077 /* 1078 * For ARM Thumb instruction, the bit 0 of st_value is set 1079 * if the symbol is STT_FUNC type. Mask it to get the address. 1080 */ 1081 if (is_arm && ELF_ST_TYPE(sym->st_info) == STT_FUNC) 1082 sym_addr &= ~1; 1083 1084 if (addr >= sym_addr) 1085 distance = addr - sym_addr; 1086 else if (allow_negative) 1087 distance = sym_addr - addr; 1088 else 1089 continue; 1090 1091 if (distance <= min_distance) { 1092 min_distance = distance; 1093 near = sym; 1094 } 1095 1096 if (min_distance == 0) 1097 break; 1098 } 1099 return near; 1100 } 1101 1102 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 1103 unsigned int secndx) 1104 { 1105 return find_nearest_sym(elf, addr, secndx, false, ~0); 1106 } 1107 1108 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 1109 { 1110 /* If the supplied symbol has a valid name, return it */ 1111 if (is_valid_name(elf, sym)) 1112 return sym; 1113 1114 /* 1115 * Strive to find a better symbol name, but the resulting name may not 1116 * match the symbol referenced in the original code. 1117 */ 1118 return find_nearest_sym(elf, addr, get_secindex(elf, sym), true, 20); 1119 } 1120 1121 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1122 { 1123 if (secndx >= elf->num_sections) 1124 return false; 1125 1126 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1127 } 1128 1129 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1130 const struct sectioncheck* const mismatch, 1131 Elf_Sym *tsym, 1132 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1133 const char *tosec, Elf_Addr taddr) 1134 { 1135 Elf_Sym *from; 1136 const char *tosym; 1137 const char *fromsym; 1138 1139 from = find_fromsym(elf, faddr, fsecndx); 1140 fromsym = sym_name(elf, from); 1141 1142 tsym = find_tosym(elf, taddr, tsym); 1143 tosym = sym_name(elf, tsym); 1144 1145 /* check whitelist - we may ignore it */ 1146 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1147 return; 1148 1149 sec_mismatch_count++; 1150 1151 warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n", 1152 modname, fromsym, (unsigned int)(faddr - from->st_value), fromsec, tosym, tosec); 1153 1154 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1155 if (match(tosec, mismatch->bad_tosec)) 1156 fatal("The relocation at %s+0x%lx references\n" 1157 "section \"%s\" which is black-listed.\n" 1158 "Something is seriously wrong and should be fixed.\n" 1159 "You might get more information about where this is\n" 1160 "coming from by using scripts/check_extable.sh %s\n", 1161 fromsec, (long)faddr, tosec, modname); 1162 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1163 warn("The relocation at %s+0x%lx references\n" 1164 "section \"%s\" which is not in the list of\n" 1165 "authorized sections. If you're adding a new section\n" 1166 "and/or if this reference is valid, add \"%s\" to the\n" 1167 "list of authorized sections to jump to on fault.\n" 1168 "This can be achieved by adding \"%s\" to\n" 1169 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1170 fromsec, (long)faddr, tosec, tosec, tosec); 1171 else 1172 error("%s+0x%lx references non-executable section '%s'\n", 1173 fromsec, (long)faddr, tosec); 1174 } 1175 } 1176 1177 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1178 Elf_Addr faddr, const char *secname, 1179 Elf_Sym *sym) 1180 { 1181 static const char *prefix = "__export_symbol_"; 1182 const char *label_name, *name, *data; 1183 Elf_Sym *label; 1184 struct symbol *s; 1185 bool is_gpl; 1186 1187 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1188 label_name = sym_name(elf, label); 1189 1190 if (!strstarts(label_name, prefix)) { 1191 error("%s: .export_symbol section contains strange symbol '%s'\n", 1192 mod->name, label_name); 1193 return; 1194 } 1195 1196 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1197 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1198 error("%s: local symbol '%s' was exported\n", mod->name, 1199 label_name + strlen(prefix)); 1200 return; 1201 } 1202 1203 name = sym_name(elf, sym); 1204 if (strcmp(label_name + strlen(prefix), name)) { 1205 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1206 mod->name, name); 1207 return; 1208 } 1209 1210 data = sym_get_data(elf, label); /* license */ 1211 if (!strcmp(data, "GPL")) { 1212 is_gpl = true; 1213 } else if (!strcmp(data, "")) { 1214 is_gpl = false; 1215 } else { 1216 error("%s: unknown license '%s' was specified for '%s'\n", 1217 mod->name, data, name); 1218 return; 1219 } 1220 1221 data += strlen(data) + 1; /* namespace */ 1222 s = sym_add_exported(name, mod, is_gpl, data); 1223 1224 /* 1225 * We need to be aware whether we are exporting a function or 1226 * a data on some architectures. 1227 */ 1228 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1229 1230 if (match(secname, PATTERNS(INIT_SECTIONS))) 1231 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1232 mod->name, name); 1233 else if (match(secname, PATTERNS(EXIT_SECTIONS))) 1234 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1235 mod->name, name); 1236 } 1237 1238 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1239 Elf_Sym *sym, 1240 unsigned int fsecndx, const char *fromsec, 1241 Elf_Addr faddr, Elf_Addr taddr) 1242 { 1243 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1244 const struct sectioncheck *mismatch; 1245 1246 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1247 check_export_symbol(mod, elf, faddr, tosec, sym); 1248 return; 1249 } 1250 1251 mismatch = section_mismatch(fromsec, tosec); 1252 if (!mismatch) 1253 return; 1254 1255 default_mismatch_handler(mod->name, elf, mismatch, sym, 1256 fsecndx, fromsec, faddr, 1257 tosec, taddr); 1258 } 1259 1260 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1261 { 1262 switch (r_type) { 1263 case R_386_32: 1264 return TO_NATIVE(*location); 1265 case R_386_PC32: 1266 return TO_NATIVE(*location) + 4; 1267 } 1268 1269 return (Elf_Addr)(-1); 1270 } 1271 1272 #ifndef R_ARM_CALL 1273 #define R_ARM_CALL 28 1274 #endif 1275 #ifndef R_ARM_JUMP24 1276 #define R_ARM_JUMP24 29 1277 #endif 1278 1279 #ifndef R_ARM_THM_CALL 1280 #define R_ARM_THM_CALL 10 1281 #endif 1282 #ifndef R_ARM_THM_JUMP24 1283 #define R_ARM_THM_JUMP24 30 1284 #endif 1285 1286 #ifndef R_ARM_MOVW_ABS_NC 1287 #define R_ARM_MOVW_ABS_NC 43 1288 #endif 1289 1290 #ifndef R_ARM_MOVT_ABS 1291 #define R_ARM_MOVT_ABS 44 1292 #endif 1293 1294 #ifndef R_ARM_THM_MOVW_ABS_NC 1295 #define R_ARM_THM_MOVW_ABS_NC 47 1296 #endif 1297 1298 #ifndef R_ARM_THM_MOVT_ABS 1299 #define R_ARM_THM_MOVT_ABS 48 1300 #endif 1301 1302 #ifndef R_ARM_THM_JUMP19 1303 #define R_ARM_THM_JUMP19 51 1304 #endif 1305 1306 static int32_t sign_extend32(int32_t value, int index) 1307 { 1308 uint8_t shift = 31 - index; 1309 1310 return (int32_t)(value << shift) >> shift; 1311 } 1312 1313 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1314 { 1315 uint32_t inst, upper, lower, sign, j1, j2; 1316 int32_t offset; 1317 1318 switch (r_type) { 1319 case R_ARM_ABS32: 1320 case R_ARM_REL32: 1321 inst = TO_NATIVE(*(uint32_t *)loc); 1322 return inst + sym->st_value; 1323 case R_ARM_MOVW_ABS_NC: 1324 case R_ARM_MOVT_ABS: 1325 inst = TO_NATIVE(*(uint32_t *)loc); 1326 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1327 15); 1328 return offset + sym->st_value; 1329 case R_ARM_PC24: 1330 case R_ARM_CALL: 1331 case R_ARM_JUMP24: 1332 inst = TO_NATIVE(*(uint32_t *)loc); 1333 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1334 return offset + sym->st_value + 8; 1335 case R_ARM_THM_MOVW_ABS_NC: 1336 case R_ARM_THM_MOVT_ABS: 1337 upper = TO_NATIVE(*(uint16_t *)loc); 1338 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1339 offset = sign_extend32(((upper & 0x000f) << 12) | 1340 ((upper & 0x0400) << 1) | 1341 ((lower & 0x7000) >> 4) | 1342 (lower & 0x00ff), 1343 15); 1344 return offset + sym->st_value; 1345 case R_ARM_THM_JUMP19: 1346 /* 1347 * Encoding T3: 1348 * S = upper[10] 1349 * imm6 = upper[5:0] 1350 * J1 = lower[13] 1351 * J2 = lower[11] 1352 * imm11 = lower[10:0] 1353 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1354 */ 1355 upper = TO_NATIVE(*(uint16_t *)loc); 1356 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1357 1358 sign = (upper >> 10) & 1; 1359 j1 = (lower >> 13) & 1; 1360 j2 = (lower >> 11) & 1; 1361 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1362 ((upper & 0x03f) << 12) | 1363 ((lower & 0x07ff) << 1), 1364 20); 1365 return offset + sym->st_value + 4; 1366 case R_ARM_THM_CALL: 1367 case R_ARM_THM_JUMP24: 1368 /* 1369 * Encoding T4: 1370 * S = upper[10] 1371 * imm10 = upper[9:0] 1372 * J1 = lower[13] 1373 * J2 = lower[11] 1374 * imm11 = lower[10:0] 1375 * I1 = NOT(J1 XOR S) 1376 * I2 = NOT(J2 XOR S) 1377 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1378 */ 1379 upper = TO_NATIVE(*(uint16_t *)loc); 1380 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1381 1382 sign = (upper >> 10) & 1; 1383 j1 = (lower >> 13) & 1; 1384 j2 = (lower >> 11) & 1; 1385 offset = sign_extend32((sign << 24) | 1386 ((~(j1 ^ sign) & 1) << 23) | 1387 ((~(j2 ^ sign) & 1) << 22) | 1388 ((upper & 0x03ff) << 12) | 1389 ((lower & 0x07ff) << 1), 1390 24); 1391 return offset + sym->st_value + 4; 1392 } 1393 1394 return (Elf_Addr)(-1); 1395 } 1396 1397 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1398 { 1399 uint32_t inst; 1400 1401 inst = TO_NATIVE(*location); 1402 switch (r_type) { 1403 case R_MIPS_LO16: 1404 return inst & 0xffff; 1405 case R_MIPS_26: 1406 return (inst & 0x03ffffff) << 2; 1407 case R_MIPS_32: 1408 return inst; 1409 } 1410 return (Elf_Addr)(-1); 1411 } 1412 1413 #ifndef EM_RISCV 1414 #define EM_RISCV 243 1415 #endif 1416 1417 #ifndef R_RISCV_SUB32 1418 #define R_RISCV_SUB32 39 1419 #endif 1420 1421 #ifndef EM_LOONGARCH 1422 #define EM_LOONGARCH 258 1423 #endif 1424 1425 #ifndef R_LARCH_SUB32 1426 #define R_LARCH_SUB32 55 1427 #endif 1428 1429 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1430 unsigned int *r_type, unsigned int *r_sym) 1431 { 1432 typedef struct { 1433 Elf64_Word r_sym; /* Symbol index */ 1434 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1435 unsigned char r_type3; /* 3rd relocation type */ 1436 unsigned char r_type2; /* 2nd relocation type */ 1437 unsigned char r_type; /* 1st relocation type */ 1438 } Elf64_Mips_R_Info; 1439 1440 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1441 1442 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1443 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1444 1445 *r_type = mips64_r_info->r_type; 1446 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1447 return; 1448 } 1449 1450 if (is_64bit) { 1451 Elf64_Xword r_info64 = r_info; 1452 1453 r_info = TO_NATIVE(r_info64); 1454 } else { 1455 Elf32_Word r_info32 = r_info; 1456 1457 r_info = TO_NATIVE(r_info32); 1458 } 1459 1460 *r_type = ELF_R_TYPE(r_info); 1461 *r_sym = ELF_R_SYM(r_info); 1462 } 1463 1464 static void section_rela(struct module *mod, struct elf_info *elf, 1465 Elf_Shdr *sechdr) 1466 { 1467 Elf_Rela *rela; 1468 unsigned int fsecndx = sechdr->sh_info; 1469 const char *fromsec = sec_name(elf, fsecndx); 1470 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; 1471 Elf_Rela *stop = (void *)start + sechdr->sh_size; 1472 1473 /* if from section (name) is know good then skip it */ 1474 if (match(fromsec, section_white_list)) 1475 return; 1476 1477 for (rela = start; rela < stop; rela++) { 1478 Elf_Addr taddr, r_offset; 1479 unsigned int r_type, r_sym; 1480 1481 r_offset = TO_NATIVE(rela->r_offset); 1482 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1483 1484 taddr = TO_NATIVE(rela->r_addend); 1485 1486 switch (elf->hdr->e_machine) { 1487 case EM_RISCV: 1488 if (!strcmp("__ex_table", fromsec) && 1489 r_type == R_RISCV_SUB32) 1490 continue; 1491 break; 1492 case EM_LOONGARCH: 1493 if (!strcmp("__ex_table", fromsec) && 1494 r_type == R_LARCH_SUB32) 1495 continue; 1496 break; 1497 } 1498 1499 check_section_mismatch(mod, elf, elf->symtab_start + r_sym, 1500 fsecndx, fromsec, r_offset, taddr); 1501 } 1502 } 1503 1504 static void section_rel(struct module *mod, struct elf_info *elf, 1505 Elf_Shdr *sechdr) 1506 { 1507 Elf_Rel *rel; 1508 unsigned int fsecndx = sechdr->sh_info; 1509 const char *fromsec = sec_name(elf, fsecndx); 1510 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset; 1511 Elf_Rel *stop = (void *)start + sechdr->sh_size; 1512 1513 /* if from section (name) is know good then skip it */ 1514 if (match(fromsec, section_white_list)) 1515 return; 1516 1517 for (rel = start; rel < stop; rel++) { 1518 Elf_Sym *tsym; 1519 Elf_Addr taddr = 0, r_offset; 1520 unsigned int r_type, r_sym; 1521 void *loc; 1522 1523 r_offset = TO_NATIVE(rel->r_offset); 1524 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1525 1526 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1527 tsym = elf->symtab_start + r_sym; 1528 1529 switch (elf->hdr->e_machine) { 1530 case EM_386: 1531 taddr = addend_386_rel(loc, r_type); 1532 break; 1533 case EM_ARM: 1534 taddr = addend_arm_rel(loc, tsym, r_type); 1535 break; 1536 case EM_MIPS: 1537 taddr = addend_mips_rel(loc, r_type); 1538 break; 1539 default: 1540 fatal("Please add code to calculate addend for this architecture\n"); 1541 } 1542 1543 check_section_mismatch(mod, elf, tsym, 1544 fsecndx, fromsec, r_offset, taddr); 1545 } 1546 } 1547 1548 /** 1549 * A module includes a number of sections that are discarded 1550 * either when loaded or when used as built-in. 1551 * For loaded modules all functions marked __init and all data 1552 * marked __initdata will be discarded when the module has been initialized. 1553 * Likewise for modules used built-in the sections marked __exit 1554 * are discarded because __exit marked function are supposed to be called 1555 * only when a module is unloaded which never happens for built-in modules. 1556 * The check_sec_ref() function traverses all relocation records 1557 * to find all references to a section that reference a section that will 1558 * be discarded and warns about it. 1559 **/ 1560 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1561 { 1562 int i; 1563 Elf_Shdr *sechdrs = elf->sechdrs; 1564 1565 /* Walk through all sections */ 1566 for (i = 0; i < elf->num_sections; i++) { 1567 check_section(mod->name, elf, &elf->sechdrs[i]); 1568 /* We want to process only relocation sections and not .init */ 1569 if (sechdrs[i].sh_type == SHT_RELA) 1570 section_rela(mod, elf, &elf->sechdrs[i]); 1571 else if (sechdrs[i].sh_type == SHT_REL) 1572 section_rel(mod, elf, &elf->sechdrs[i]); 1573 } 1574 } 1575 1576 static char *remove_dot(char *s) 1577 { 1578 size_t n = strcspn(s, "."); 1579 1580 if (n && s[n]) { 1581 size_t m = strspn(s + n + 1, "0123456789"); 1582 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1583 s[n] = 0; 1584 } 1585 return s; 1586 } 1587 1588 /* 1589 * The CRCs are recorded in .*.cmd files in the form of: 1590 * #SYMVER <name> <crc> 1591 */ 1592 static void extract_crcs_for_object(const char *object, struct module *mod) 1593 { 1594 char cmd_file[PATH_MAX]; 1595 char *buf, *p; 1596 const char *base; 1597 int dirlen, ret; 1598 1599 base = strrchr(object, '/'); 1600 if (base) { 1601 base++; 1602 dirlen = base - object; 1603 } else { 1604 dirlen = 0; 1605 base = object; 1606 } 1607 1608 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1609 dirlen, object, base); 1610 if (ret >= sizeof(cmd_file)) { 1611 error("%s: too long path was truncated\n", cmd_file); 1612 return; 1613 } 1614 1615 buf = read_text_file(cmd_file); 1616 p = buf; 1617 1618 while ((p = strstr(p, "\n#SYMVER "))) { 1619 char *name; 1620 size_t namelen; 1621 unsigned int crc; 1622 struct symbol *sym; 1623 1624 name = p + strlen("\n#SYMVER "); 1625 1626 p = strchr(name, ' '); 1627 if (!p) 1628 break; 1629 1630 namelen = p - name; 1631 p++; 1632 1633 if (!isdigit(*p)) 1634 continue; /* skip this line */ 1635 1636 crc = strtoul(p, &p, 0); 1637 if (*p != '\n') 1638 continue; /* skip this line */ 1639 1640 name[namelen] = '\0'; 1641 1642 /* 1643 * sym_find_with_module() may return NULL here. 1644 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1645 * Since commit e1327a127703, genksyms calculates CRCs of all 1646 * symbols, including trimmed ones. Ignore orphan CRCs. 1647 */ 1648 sym = sym_find_with_module(name, mod); 1649 if (sym) 1650 sym_set_crc(sym, crc); 1651 } 1652 1653 free(buf); 1654 } 1655 1656 /* 1657 * The symbol versions (CRC) are recorded in the .*.cmd files. 1658 * Parse them to retrieve CRCs for the current module. 1659 */ 1660 static void mod_set_crcs(struct module *mod) 1661 { 1662 char objlist[PATH_MAX]; 1663 char *buf, *p, *obj; 1664 int ret; 1665 1666 if (mod->is_vmlinux) { 1667 strcpy(objlist, ".vmlinux.objs"); 1668 } else { 1669 /* objects for a module are listed in the *.mod file. */ 1670 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1671 if (ret >= sizeof(objlist)) { 1672 error("%s: too long path was truncated\n", objlist); 1673 return; 1674 } 1675 } 1676 1677 buf = read_text_file(objlist); 1678 p = buf; 1679 1680 while ((obj = strsep(&p, "\n")) && obj[0]) 1681 extract_crcs_for_object(obj, mod); 1682 1683 free(buf); 1684 } 1685 1686 static void read_symbols(const char *modname) 1687 { 1688 const char *symname; 1689 char *version; 1690 char *license; 1691 char *namespace; 1692 struct module *mod; 1693 struct elf_info info = { }; 1694 Elf_Sym *sym; 1695 1696 if (!parse_elf(&info, modname)) 1697 return; 1698 1699 if (!strends(modname, ".o")) { 1700 error("%s: filename must be suffixed with .o\n", modname); 1701 return; 1702 } 1703 1704 /* strip trailing .o */ 1705 mod = new_module(modname, strlen(modname) - strlen(".o")); 1706 1707 if (!mod->is_vmlinux) { 1708 license = get_modinfo(&info, "license"); 1709 if (!license) 1710 error("missing MODULE_LICENSE() in %s\n", modname); 1711 while (license) { 1712 if (!license_is_gpl_compatible(license)) { 1713 mod->is_gpl_compatible = false; 1714 break; 1715 } 1716 license = get_next_modinfo(&info, "license", license); 1717 } 1718 1719 namespace = get_modinfo(&info, "import_ns"); 1720 while (namespace) { 1721 add_namespace(&mod->imported_namespaces, namespace); 1722 namespace = get_next_modinfo(&info, "import_ns", 1723 namespace); 1724 } 1725 } 1726 1727 if (extra_warn && !get_modinfo(&info, "description")) 1728 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1729 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1730 symname = remove_dot(info.strtab + sym->st_name); 1731 1732 handle_symbol(mod, &info, sym, symname); 1733 handle_moddevtable(mod, &info, sym, symname); 1734 } 1735 1736 check_sec_ref(mod, &info); 1737 1738 if (!mod->is_vmlinux) { 1739 version = get_modinfo(&info, "version"); 1740 if (version || all_versions) 1741 get_src_version(mod->name, mod->srcversion, 1742 sizeof(mod->srcversion) - 1); 1743 } 1744 1745 parse_elf_finish(&info); 1746 1747 if (modversions) { 1748 /* 1749 * Our trick to get versioning for module struct etc. - it's 1750 * never passed as an argument to an exported function, so 1751 * the automatic versioning doesn't pick it up, but it's really 1752 * important anyhow. 1753 */ 1754 sym_add_unresolved("module_layout", mod, false); 1755 1756 mod_set_crcs(mod); 1757 } 1758 } 1759 1760 static void read_symbols_from_files(const char *filename) 1761 { 1762 FILE *in = stdin; 1763 char fname[PATH_MAX]; 1764 1765 in = fopen(filename, "r"); 1766 if (!in) 1767 fatal("Can't open filenames file %s: %m", filename); 1768 1769 while (fgets(fname, PATH_MAX, in) != NULL) { 1770 if (strends(fname, "\n")) 1771 fname[strlen(fname)-1] = '\0'; 1772 read_symbols(fname); 1773 } 1774 1775 fclose(in); 1776 } 1777 1778 #define SZ 500 1779 1780 /* We first write the generated file into memory using the 1781 * following helper, then compare to the file on disk and 1782 * only update the later if anything changed */ 1783 1784 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1785 const char *fmt, ...) 1786 { 1787 char tmp[SZ]; 1788 int len; 1789 va_list ap; 1790 1791 va_start(ap, fmt); 1792 len = vsnprintf(tmp, SZ, fmt, ap); 1793 buf_write(buf, tmp, len); 1794 va_end(ap); 1795 } 1796 1797 void buf_write(struct buffer *buf, const char *s, int len) 1798 { 1799 if (buf->size - buf->pos < len) { 1800 buf->size += len + SZ; 1801 buf->p = NOFAIL(realloc(buf->p, buf->size)); 1802 } 1803 strncpy(buf->p + buf->pos, s, len); 1804 buf->pos += len; 1805 } 1806 1807 static void check_exports(struct module *mod) 1808 { 1809 struct symbol *s, *exp; 1810 1811 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1812 const char *basename; 1813 exp = find_symbol(s->name); 1814 if (!exp) { 1815 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1816 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, 1817 "\"%s\" [%s.ko] undefined!\n", 1818 s->name, mod->name); 1819 continue; 1820 } 1821 if (exp->module == mod) { 1822 error("\"%s\" [%s.ko] was exported without definition\n", 1823 s->name, mod->name); 1824 continue; 1825 } 1826 1827 exp->used = true; 1828 s->module = exp->module; 1829 s->crc_valid = exp->crc_valid; 1830 s->crc = exp->crc; 1831 1832 basename = strrchr(mod->name, '/'); 1833 if (basename) 1834 basename++; 1835 else 1836 basename = mod->name; 1837 1838 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1839 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, 1840 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1841 basename, exp->name, exp->namespace); 1842 add_namespace(&mod->missing_namespaces, exp->namespace); 1843 } 1844 1845 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1846 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1847 basename, exp->name); 1848 } 1849 } 1850 1851 static void handle_white_list_exports(const char *white_list) 1852 { 1853 char *buf, *p, *name; 1854 1855 buf = read_text_file(white_list); 1856 p = buf; 1857 1858 while ((name = strsep(&p, "\n"))) { 1859 struct symbol *sym = find_symbol(name); 1860 1861 if (sym) 1862 sym->used = true; 1863 } 1864 1865 free(buf); 1866 } 1867 1868 static void check_modname_len(struct module *mod) 1869 { 1870 const char *mod_name; 1871 1872 mod_name = strrchr(mod->name, '/'); 1873 if (mod_name == NULL) 1874 mod_name = mod->name; 1875 else 1876 mod_name++; 1877 if (strlen(mod_name) >= MODULE_NAME_LEN) 1878 error("module name is too long [%s.ko]\n", mod->name); 1879 } 1880 1881 /** 1882 * Header for the generated file 1883 **/ 1884 static void add_header(struct buffer *b, struct module *mod) 1885 { 1886 buf_printf(b, "#include <linux/module.h>\n"); 1887 /* 1888 * Include build-salt.h after module.h in order to 1889 * inherit the definitions. 1890 */ 1891 buf_printf(b, "#define INCLUDE_VERMAGIC\n"); 1892 buf_printf(b, "#include <linux/build-salt.h>\n"); 1893 buf_printf(b, "#include <linux/elfnote-lto.h>\n"); 1894 buf_printf(b, "#include <linux/export-internal.h>\n"); 1895 buf_printf(b, "#include <linux/vermagic.h>\n"); 1896 buf_printf(b, "#include <linux/compiler.h>\n"); 1897 buf_printf(b, "\n"); 1898 buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n"); 1899 buf_printf(b, "#include <asm/orc_header.h>\n"); 1900 buf_printf(b, "ORC_HEADER;\n"); 1901 buf_printf(b, "#endif\n"); 1902 buf_printf(b, "\n"); 1903 buf_printf(b, "BUILD_SALT;\n"); 1904 buf_printf(b, "BUILD_LTO_INFO;\n"); 1905 buf_printf(b, "\n"); 1906 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1907 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1908 buf_printf(b, "\n"); 1909 buf_printf(b, "__visible struct module __this_module\n"); 1910 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1911 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1912 if (mod->has_init) 1913 buf_printf(b, "\t.init = init_module,\n"); 1914 if (mod->has_cleanup) 1915 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1916 "\t.exit = cleanup_module,\n" 1917 "#endif\n"); 1918 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1919 buf_printf(b, "};\n"); 1920 1921 if (!external_module) 1922 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1923 1924 buf_printf(b, 1925 "\n" 1926 "#ifdef CONFIG_RETPOLINE\n" 1927 "MODULE_INFO(retpoline, \"Y\");\n" 1928 "#endif\n"); 1929 1930 if (strstarts(mod->name, "drivers/staging")) 1931 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1932 1933 if (strstarts(mod->name, "tools/testing")) 1934 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1935 } 1936 1937 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1938 { 1939 struct symbol *sym; 1940 1941 /* generate struct for exported symbols */ 1942 buf_printf(buf, "\n"); 1943 list_for_each_entry(sym, &mod->exported_symbols, list) { 1944 if (trim_unused_exports && !sym->used) 1945 continue; 1946 1947 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1948 sym->is_func ? "FUNC" : "DATA", sym->name, 1949 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1950 } 1951 1952 if (!modversions) 1953 return; 1954 1955 /* record CRCs for exported symbols */ 1956 buf_printf(buf, "\n"); 1957 list_for_each_entry(sym, &mod->exported_symbols, list) { 1958 if (trim_unused_exports && !sym->used) 1959 continue; 1960 1961 if (!sym->crc_valid) 1962 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1963 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1964 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1965 sym->name); 1966 1967 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1968 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1969 } 1970 } 1971 1972 /** 1973 * Record CRCs for unresolved symbols 1974 **/ 1975 static void add_versions(struct buffer *b, struct module *mod) 1976 { 1977 struct symbol *s; 1978 1979 if (!modversions) 1980 return; 1981 1982 buf_printf(b, "\n"); 1983 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1984 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1985 1986 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1987 if (!s->module) 1988 continue; 1989 if (!s->crc_valid) { 1990 warn("\"%s\" [%s.ko] has no CRC!\n", 1991 s->name, mod->name); 1992 continue; 1993 } 1994 if (strlen(s->name) >= MODULE_NAME_LEN) { 1995 error("too long symbol \"%s\" [%s.ko]\n", 1996 s->name, mod->name); 1997 break; 1998 } 1999 buf_printf(b, "\t{ %#8x, \"%s\" },\n", 2000 s->crc, s->name); 2001 } 2002 2003 buf_printf(b, "};\n"); 2004 } 2005 2006 static void add_depends(struct buffer *b, struct module *mod) 2007 { 2008 struct symbol *s; 2009 int first = 1; 2010 2011 /* Clear ->seen flag of modules that own symbols needed by this. */ 2012 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2013 if (s->module) 2014 s->module->seen = s->module->is_vmlinux; 2015 } 2016 2017 buf_printf(b, "\n"); 2018 buf_printf(b, "MODULE_INFO(depends, \""); 2019 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2020 const char *p; 2021 if (!s->module) 2022 continue; 2023 2024 if (s->module->seen) 2025 continue; 2026 2027 s->module->seen = true; 2028 p = strrchr(s->module->name, '/'); 2029 if (p) 2030 p++; 2031 else 2032 p = s->module->name; 2033 buf_printf(b, "%s%s", first ? "" : ",", p); 2034 first = 0; 2035 } 2036 buf_printf(b, "\");\n"); 2037 } 2038 2039 static void add_srcversion(struct buffer *b, struct module *mod) 2040 { 2041 if (mod->srcversion[0]) { 2042 buf_printf(b, "\n"); 2043 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 2044 mod->srcversion); 2045 } 2046 } 2047 2048 static void write_buf(struct buffer *b, const char *fname) 2049 { 2050 FILE *file; 2051 2052 if (error_occurred) 2053 return; 2054 2055 file = fopen(fname, "w"); 2056 if (!file) { 2057 perror(fname); 2058 exit(1); 2059 } 2060 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2061 perror(fname); 2062 exit(1); 2063 } 2064 if (fclose(file) != 0) { 2065 perror(fname); 2066 exit(1); 2067 } 2068 } 2069 2070 static void write_if_changed(struct buffer *b, const char *fname) 2071 { 2072 char *tmp; 2073 FILE *file; 2074 struct stat st; 2075 2076 file = fopen(fname, "r"); 2077 if (!file) 2078 goto write; 2079 2080 if (fstat(fileno(file), &st) < 0) 2081 goto close_write; 2082 2083 if (st.st_size != b->pos) 2084 goto close_write; 2085 2086 tmp = NOFAIL(malloc(b->pos)); 2087 if (fread(tmp, 1, b->pos, file) != b->pos) 2088 goto free_write; 2089 2090 if (memcmp(tmp, b->p, b->pos) != 0) 2091 goto free_write; 2092 2093 free(tmp); 2094 fclose(file); 2095 return; 2096 2097 free_write: 2098 free(tmp); 2099 close_write: 2100 fclose(file); 2101 write: 2102 write_buf(b, fname); 2103 } 2104 2105 static void write_vmlinux_export_c_file(struct module *mod) 2106 { 2107 struct buffer buf = { }; 2108 2109 buf_printf(&buf, 2110 "#include <linux/export-internal.h>\n"); 2111 2112 add_exported_symbols(&buf, mod); 2113 write_if_changed(&buf, ".vmlinux.export.c"); 2114 free(buf.p); 2115 } 2116 2117 /* do sanity checks, and generate *.mod.c file */ 2118 static void write_mod_c_file(struct module *mod) 2119 { 2120 struct buffer buf = { }; 2121 char fname[PATH_MAX]; 2122 int ret; 2123 2124 add_header(&buf, mod); 2125 add_exported_symbols(&buf, mod); 2126 add_versions(&buf, mod); 2127 add_depends(&buf, mod); 2128 add_moddevtable(&buf, mod); 2129 add_srcversion(&buf, mod); 2130 2131 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2132 if (ret >= sizeof(fname)) { 2133 error("%s: too long path was truncated\n", fname); 2134 goto free; 2135 } 2136 2137 write_if_changed(&buf, fname); 2138 2139 free: 2140 free(buf.p); 2141 } 2142 2143 /* parse Module.symvers file. line format: 2144 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2145 **/ 2146 static void read_dump(const char *fname) 2147 { 2148 char *buf, *pos, *line; 2149 2150 buf = read_text_file(fname); 2151 if (!buf) 2152 /* No symbol versions, silently ignore */ 2153 return; 2154 2155 pos = buf; 2156 2157 while ((line = get_line(&pos))) { 2158 char *symname, *namespace, *modname, *d, *export; 2159 unsigned int crc; 2160 struct module *mod; 2161 struct symbol *s; 2162 bool gpl_only; 2163 2164 if (!(symname = strchr(line, '\t'))) 2165 goto fail; 2166 *symname++ = '\0'; 2167 if (!(modname = strchr(symname, '\t'))) 2168 goto fail; 2169 *modname++ = '\0'; 2170 if (!(export = strchr(modname, '\t'))) 2171 goto fail; 2172 *export++ = '\0'; 2173 if (!(namespace = strchr(export, '\t'))) 2174 goto fail; 2175 *namespace++ = '\0'; 2176 2177 crc = strtoul(line, &d, 16); 2178 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2179 goto fail; 2180 2181 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2182 gpl_only = true; 2183 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2184 gpl_only = false; 2185 } else { 2186 error("%s: unknown license %s. skip", symname, export); 2187 continue; 2188 } 2189 2190 mod = find_module(modname); 2191 if (!mod) { 2192 mod = new_module(modname, strlen(modname)); 2193 mod->from_dump = true; 2194 } 2195 s = sym_add_exported(symname, mod, gpl_only, namespace); 2196 sym_set_crc(s, crc); 2197 } 2198 free(buf); 2199 return; 2200 fail: 2201 free(buf); 2202 fatal("parse error in symbol dump file\n"); 2203 } 2204 2205 static void write_dump(const char *fname) 2206 { 2207 struct buffer buf = { }; 2208 struct module *mod; 2209 struct symbol *sym; 2210 2211 list_for_each_entry(mod, &modules, list) { 2212 if (mod->from_dump) 2213 continue; 2214 list_for_each_entry(sym, &mod->exported_symbols, list) { 2215 if (trim_unused_exports && !sym->used) 2216 continue; 2217 2218 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2219 sym->crc, sym->name, mod->name, 2220 sym->is_gpl_only ? "_GPL" : "", 2221 sym->namespace); 2222 } 2223 } 2224 write_buf(&buf, fname); 2225 free(buf.p); 2226 } 2227 2228 static void write_namespace_deps_files(const char *fname) 2229 { 2230 struct module *mod; 2231 struct namespace_list *ns; 2232 struct buffer ns_deps_buf = {}; 2233 2234 list_for_each_entry(mod, &modules, list) { 2235 2236 if (mod->from_dump || list_empty(&mod->missing_namespaces)) 2237 continue; 2238 2239 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2240 2241 list_for_each_entry(ns, &mod->missing_namespaces, list) 2242 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2243 2244 buf_printf(&ns_deps_buf, "\n"); 2245 } 2246 2247 write_if_changed(&ns_deps_buf, fname); 2248 free(ns_deps_buf.p); 2249 } 2250 2251 struct dump_list { 2252 struct list_head list; 2253 const char *file; 2254 }; 2255 2256 int main(int argc, char **argv) 2257 { 2258 struct module *mod; 2259 char *missing_namespace_deps = NULL; 2260 char *unused_exports_white_list = NULL; 2261 char *dump_write = NULL, *files_source = NULL; 2262 int opt; 2263 LIST_HEAD(dump_lists); 2264 struct dump_list *dl, *dl2; 2265 2266 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) { 2267 switch (opt) { 2268 case 'e': 2269 external_module = true; 2270 break; 2271 case 'i': 2272 dl = NOFAIL(malloc(sizeof(*dl))); 2273 dl->file = optarg; 2274 list_add_tail(&dl->list, &dump_lists); 2275 break; 2276 case 'M': 2277 module_enabled = true; 2278 break; 2279 case 'm': 2280 modversions = true; 2281 break; 2282 case 'n': 2283 ignore_missing_files = true; 2284 break; 2285 case 'o': 2286 dump_write = optarg; 2287 break; 2288 case 'a': 2289 all_versions = true; 2290 break; 2291 case 'T': 2292 files_source = optarg; 2293 break; 2294 case 't': 2295 trim_unused_exports = true; 2296 break; 2297 case 'u': 2298 unused_exports_white_list = optarg; 2299 break; 2300 case 'W': 2301 extra_warn = true; 2302 break; 2303 case 'w': 2304 warn_unresolved = true; 2305 break; 2306 case 'E': 2307 sec_mismatch_warn_only = false; 2308 break; 2309 case 'N': 2310 allow_missing_ns_imports = true; 2311 break; 2312 case 'd': 2313 missing_namespace_deps = optarg; 2314 break; 2315 default: 2316 exit(1); 2317 } 2318 } 2319 2320 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2321 read_dump(dl->file); 2322 list_del(&dl->list); 2323 free(dl); 2324 } 2325 2326 while (optind < argc) 2327 read_symbols(argv[optind++]); 2328 2329 if (files_source) 2330 read_symbols_from_files(files_source); 2331 2332 list_for_each_entry(mod, &modules, list) { 2333 if (mod->from_dump || mod->is_vmlinux) 2334 continue; 2335 2336 check_modname_len(mod); 2337 check_exports(mod); 2338 } 2339 2340 if (unused_exports_white_list) 2341 handle_white_list_exports(unused_exports_white_list); 2342 2343 list_for_each_entry(mod, &modules, list) { 2344 if (mod->from_dump) 2345 continue; 2346 2347 if (mod->is_vmlinux) 2348 write_vmlinux_export_c_file(mod); 2349 else 2350 write_mod_c_file(mod); 2351 } 2352 2353 if (missing_namespace_deps) 2354 write_namespace_deps_files(missing_namespace_deps); 2355 2356 if (dump_write) 2357 write_dump(dump_write); 2358 if (sec_mismatch_count && !sec_mismatch_warn_only) 2359 error("Section mismatches detected.\n" 2360 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2361 2362 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2363 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2364 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2365 2366 return error_occurred ? 1 : 0; 2367 } 2368