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 sections */ 1019 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 1020 match(tosec, PATTERNS(ALL_XXXINIT_SECTIONS, ALL_XXXEXIT_SECTIONS)) && 1021 match(fromsym, PATTERNS("*driver"))) 1022 return 0; 1023 1024 /* 1025 * symbols in data sections must not refer to .exit.*, but there are 1026 * quite a few offenders, so hide these unless for W=1 builds until 1027 * these are fixed. 1028 */ 1029 if (!extra_warn && 1030 match(fromsec, PATTERNS(DATA_SECTIONS)) && 1031 match(tosec, PATTERNS(EXIT_SECTIONS)) && 1032 match(fromsym, PATTERNS("*driver"))) 1033 return 0; 1034 1035 /* Check for pattern 3 */ 1036 if (strstarts(fromsec, ".head.text") && 1037 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 1038 return 0; 1039 1040 /* Check for pattern 4 */ 1041 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 1042 return 0; 1043 1044 /* Check for pattern 5 */ 1045 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 1046 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 1047 match(fromsym, PATTERNS("*.constprop.*"))) 1048 return 0; 1049 1050 return 1; 1051 } 1052 1053 /* 1054 * If there's no name there, ignore it; likewise, ignore it if it's 1055 * one of the magic symbols emitted used by current tools. 1056 * 1057 * Otherwise if find_symbols_between() returns those symbols, they'll 1058 * fail the whitelist tests and cause lots of false alarms ... fixable 1059 * only by merging __exit and __init sections into __text, bloating 1060 * the kernel (which is especially evil on embedded platforms). 1061 */ 1062 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 1063 { 1064 const char *name = elf->strtab + sym->st_name; 1065 1066 if (!name || !strlen(name)) 1067 return 0; 1068 return !is_mapping_symbol(name); 1069 } 1070 1071 /* Look up the nearest symbol based on the section and the address */ 1072 static Elf_Sym *find_nearest_sym(struct elf_info *elf, Elf_Addr addr, 1073 unsigned int secndx, bool allow_negative, 1074 Elf_Addr min_distance) 1075 { 1076 Elf_Sym *sym; 1077 Elf_Sym *near = NULL; 1078 Elf_Addr sym_addr, distance; 1079 bool is_arm = (elf->hdr->e_machine == EM_ARM); 1080 1081 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1082 if (get_secindex(elf, sym) != secndx) 1083 continue; 1084 if (!is_valid_name(elf, sym)) 1085 continue; 1086 1087 sym_addr = sym->st_value; 1088 1089 /* 1090 * For ARM Thumb instruction, the bit 0 of st_value is set 1091 * if the symbol is STT_FUNC type. Mask it to get the address. 1092 */ 1093 if (is_arm && ELF_ST_TYPE(sym->st_info) == STT_FUNC) 1094 sym_addr &= ~1; 1095 1096 if (addr >= sym_addr) 1097 distance = addr - sym_addr; 1098 else if (allow_negative) 1099 distance = sym_addr - addr; 1100 else 1101 continue; 1102 1103 if (distance <= min_distance) { 1104 min_distance = distance; 1105 near = sym; 1106 } 1107 1108 if (min_distance == 0) 1109 break; 1110 } 1111 return near; 1112 } 1113 1114 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 1115 unsigned int secndx) 1116 { 1117 return find_nearest_sym(elf, addr, secndx, false, ~0); 1118 } 1119 1120 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 1121 { 1122 /* If the supplied symbol has a valid name, return it */ 1123 if (is_valid_name(elf, sym)) 1124 return sym; 1125 1126 /* 1127 * Strive to find a better symbol name, but the resulting name may not 1128 * match the symbol referenced in the original code. 1129 */ 1130 return find_nearest_sym(elf, addr, get_secindex(elf, sym), true, 20); 1131 } 1132 1133 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1134 { 1135 if (secndx >= elf->num_sections) 1136 return false; 1137 1138 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1139 } 1140 1141 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1142 const struct sectioncheck* const mismatch, 1143 Elf_Sym *tsym, 1144 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1145 const char *tosec, Elf_Addr taddr) 1146 { 1147 Elf_Sym *from; 1148 const char *tosym; 1149 const char *fromsym; 1150 1151 from = find_fromsym(elf, faddr, fsecndx); 1152 fromsym = sym_name(elf, from); 1153 1154 tsym = find_tosym(elf, taddr, tsym); 1155 tosym = sym_name(elf, tsym); 1156 1157 /* check whitelist - we may ignore it */ 1158 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1159 return; 1160 1161 sec_mismatch_count++; 1162 1163 warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n", 1164 modname, fromsym, (unsigned int)(faddr - from->st_value), fromsec, tosym, tosec); 1165 1166 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1167 if (match(tosec, mismatch->bad_tosec)) 1168 fatal("The relocation at %s+0x%lx references\n" 1169 "section \"%s\" which is black-listed.\n" 1170 "Something is seriously wrong and should be fixed.\n" 1171 "You might get more information about where this is\n" 1172 "coming from by using scripts/check_extable.sh %s\n", 1173 fromsec, (long)faddr, tosec, modname); 1174 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1175 warn("The relocation at %s+0x%lx references\n" 1176 "section \"%s\" which is not in the list of\n" 1177 "authorized sections. If you're adding a new section\n" 1178 "and/or if this reference is valid, add \"%s\" to the\n" 1179 "list of authorized sections to jump to on fault.\n" 1180 "This can be achieved by adding \"%s\" to\n" 1181 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1182 fromsec, (long)faddr, tosec, tosec, tosec); 1183 else 1184 error("%s+0x%lx references non-executable section '%s'\n", 1185 fromsec, (long)faddr, tosec); 1186 } 1187 } 1188 1189 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1190 Elf_Addr faddr, const char *secname, 1191 Elf_Sym *sym) 1192 { 1193 static const char *prefix = "__export_symbol_"; 1194 const char *label_name, *name, *data; 1195 Elf_Sym *label; 1196 struct symbol *s; 1197 bool is_gpl; 1198 1199 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1200 label_name = sym_name(elf, label); 1201 1202 if (!strstarts(label_name, prefix)) { 1203 error("%s: .export_symbol section contains strange symbol '%s'\n", 1204 mod->name, label_name); 1205 return; 1206 } 1207 1208 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1209 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1210 error("%s: local symbol '%s' was exported\n", mod->name, 1211 label_name + strlen(prefix)); 1212 return; 1213 } 1214 1215 name = sym_name(elf, sym); 1216 if (strcmp(label_name + strlen(prefix), name)) { 1217 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1218 mod->name, name); 1219 return; 1220 } 1221 1222 data = sym_get_data(elf, label); /* license */ 1223 if (!strcmp(data, "GPL")) { 1224 is_gpl = true; 1225 } else if (!strcmp(data, "")) { 1226 is_gpl = false; 1227 } else { 1228 error("%s: unknown license '%s' was specified for '%s'\n", 1229 mod->name, data, name); 1230 return; 1231 } 1232 1233 data += strlen(data) + 1; /* namespace */ 1234 s = sym_add_exported(name, mod, is_gpl, data); 1235 1236 /* 1237 * We need to be aware whether we are exporting a function or 1238 * a data on some architectures. 1239 */ 1240 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1241 1242 /* 1243 * For parisc64, symbols prefixed $$ from the library have the symbol type 1244 * STT_LOPROC. They should be handled as functions too. 1245 */ 1246 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1247 elf->hdr->e_machine == EM_PARISC && 1248 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1249 s->is_func = true; 1250 1251 if (match(secname, PATTERNS(INIT_SECTIONS))) 1252 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1253 mod->name, name); 1254 else if (match(secname, PATTERNS(EXIT_SECTIONS))) 1255 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1256 mod->name, name); 1257 } 1258 1259 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1260 Elf_Sym *sym, 1261 unsigned int fsecndx, const char *fromsec, 1262 Elf_Addr faddr, Elf_Addr taddr) 1263 { 1264 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1265 const struct sectioncheck *mismatch; 1266 1267 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1268 check_export_symbol(mod, elf, faddr, tosec, sym); 1269 return; 1270 } 1271 1272 mismatch = section_mismatch(fromsec, tosec); 1273 if (!mismatch) 1274 return; 1275 1276 default_mismatch_handler(mod->name, elf, mismatch, sym, 1277 fsecndx, fromsec, faddr, 1278 tosec, taddr); 1279 } 1280 1281 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1282 { 1283 switch (r_type) { 1284 case R_386_32: 1285 return TO_NATIVE(*location); 1286 case R_386_PC32: 1287 return TO_NATIVE(*location) + 4; 1288 } 1289 1290 return (Elf_Addr)(-1); 1291 } 1292 1293 #ifndef R_ARM_CALL 1294 #define R_ARM_CALL 28 1295 #endif 1296 #ifndef R_ARM_JUMP24 1297 #define R_ARM_JUMP24 29 1298 #endif 1299 1300 #ifndef R_ARM_THM_CALL 1301 #define R_ARM_THM_CALL 10 1302 #endif 1303 #ifndef R_ARM_THM_JUMP24 1304 #define R_ARM_THM_JUMP24 30 1305 #endif 1306 1307 #ifndef R_ARM_MOVW_ABS_NC 1308 #define R_ARM_MOVW_ABS_NC 43 1309 #endif 1310 1311 #ifndef R_ARM_MOVT_ABS 1312 #define R_ARM_MOVT_ABS 44 1313 #endif 1314 1315 #ifndef R_ARM_THM_MOVW_ABS_NC 1316 #define R_ARM_THM_MOVW_ABS_NC 47 1317 #endif 1318 1319 #ifndef R_ARM_THM_MOVT_ABS 1320 #define R_ARM_THM_MOVT_ABS 48 1321 #endif 1322 1323 #ifndef R_ARM_THM_JUMP19 1324 #define R_ARM_THM_JUMP19 51 1325 #endif 1326 1327 static int32_t sign_extend32(int32_t value, int index) 1328 { 1329 uint8_t shift = 31 - index; 1330 1331 return (int32_t)(value << shift) >> shift; 1332 } 1333 1334 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1335 { 1336 uint32_t inst, upper, lower, sign, j1, j2; 1337 int32_t offset; 1338 1339 switch (r_type) { 1340 case R_ARM_ABS32: 1341 case R_ARM_REL32: 1342 inst = TO_NATIVE(*(uint32_t *)loc); 1343 return inst + sym->st_value; 1344 case R_ARM_MOVW_ABS_NC: 1345 case R_ARM_MOVT_ABS: 1346 inst = TO_NATIVE(*(uint32_t *)loc); 1347 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1348 15); 1349 return offset + sym->st_value; 1350 case R_ARM_PC24: 1351 case R_ARM_CALL: 1352 case R_ARM_JUMP24: 1353 inst = TO_NATIVE(*(uint32_t *)loc); 1354 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1355 return offset + sym->st_value + 8; 1356 case R_ARM_THM_MOVW_ABS_NC: 1357 case R_ARM_THM_MOVT_ABS: 1358 upper = TO_NATIVE(*(uint16_t *)loc); 1359 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1360 offset = sign_extend32(((upper & 0x000f) << 12) | 1361 ((upper & 0x0400) << 1) | 1362 ((lower & 0x7000) >> 4) | 1363 (lower & 0x00ff), 1364 15); 1365 return offset + sym->st_value; 1366 case R_ARM_THM_JUMP19: 1367 /* 1368 * Encoding T3: 1369 * S = upper[10] 1370 * imm6 = upper[5:0] 1371 * J1 = lower[13] 1372 * J2 = lower[11] 1373 * imm11 = lower[10:0] 1374 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1375 */ 1376 upper = TO_NATIVE(*(uint16_t *)loc); 1377 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1378 1379 sign = (upper >> 10) & 1; 1380 j1 = (lower >> 13) & 1; 1381 j2 = (lower >> 11) & 1; 1382 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1383 ((upper & 0x03f) << 12) | 1384 ((lower & 0x07ff) << 1), 1385 20); 1386 return offset + sym->st_value + 4; 1387 case R_ARM_THM_CALL: 1388 case R_ARM_THM_JUMP24: 1389 /* 1390 * Encoding T4: 1391 * S = upper[10] 1392 * imm10 = upper[9:0] 1393 * J1 = lower[13] 1394 * J2 = lower[11] 1395 * imm11 = lower[10:0] 1396 * I1 = NOT(J1 XOR S) 1397 * I2 = NOT(J2 XOR S) 1398 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1399 */ 1400 upper = TO_NATIVE(*(uint16_t *)loc); 1401 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1402 1403 sign = (upper >> 10) & 1; 1404 j1 = (lower >> 13) & 1; 1405 j2 = (lower >> 11) & 1; 1406 offset = sign_extend32((sign << 24) | 1407 ((~(j1 ^ sign) & 1) << 23) | 1408 ((~(j2 ^ sign) & 1) << 22) | 1409 ((upper & 0x03ff) << 12) | 1410 ((lower & 0x07ff) << 1), 1411 24); 1412 return offset + sym->st_value + 4; 1413 } 1414 1415 return (Elf_Addr)(-1); 1416 } 1417 1418 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1419 { 1420 uint32_t inst; 1421 1422 inst = TO_NATIVE(*location); 1423 switch (r_type) { 1424 case R_MIPS_LO16: 1425 return inst & 0xffff; 1426 case R_MIPS_26: 1427 return (inst & 0x03ffffff) << 2; 1428 case R_MIPS_32: 1429 return inst; 1430 } 1431 return (Elf_Addr)(-1); 1432 } 1433 1434 #ifndef EM_RISCV 1435 #define EM_RISCV 243 1436 #endif 1437 1438 #ifndef R_RISCV_SUB32 1439 #define R_RISCV_SUB32 39 1440 #endif 1441 1442 #ifndef EM_LOONGARCH 1443 #define EM_LOONGARCH 258 1444 #endif 1445 1446 #ifndef R_LARCH_SUB32 1447 #define R_LARCH_SUB32 55 1448 #endif 1449 1450 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1451 unsigned int *r_type, unsigned int *r_sym) 1452 { 1453 typedef struct { 1454 Elf64_Word r_sym; /* Symbol index */ 1455 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1456 unsigned char r_type3; /* 3rd relocation type */ 1457 unsigned char r_type2; /* 2nd relocation type */ 1458 unsigned char r_type; /* 1st relocation type */ 1459 } Elf64_Mips_R_Info; 1460 1461 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1462 1463 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1464 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1465 1466 *r_type = mips64_r_info->r_type; 1467 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1468 return; 1469 } 1470 1471 if (is_64bit) { 1472 Elf64_Xword r_info64 = r_info; 1473 1474 r_info = TO_NATIVE(r_info64); 1475 } else { 1476 Elf32_Word r_info32 = r_info; 1477 1478 r_info = TO_NATIVE(r_info32); 1479 } 1480 1481 *r_type = ELF_R_TYPE(r_info); 1482 *r_sym = ELF_R_SYM(r_info); 1483 } 1484 1485 static void section_rela(struct module *mod, struct elf_info *elf, 1486 Elf_Shdr *sechdr) 1487 { 1488 Elf_Rela *rela; 1489 unsigned int fsecndx = sechdr->sh_info; 1490 const char *fromsec = sec_name(elf, fsecndx); 1491 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; 1492 Elf_Rela *stop = (void *)start + sechdr->sh_size; 1493 1494 /* if from section (name) is know good then skip it */ 1495 if (match(fromsec, section_white_list)) 1496 return; 1497 1498 for (rela = start; rela < stop; rela++) { 1499 Elf_Addr taddr, r_offset; 1500 unsigned int r_type, r_sym; 1501 1502 r_offset = TO_NATIVE(rela->r_offset); 1503 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1504 1505 taddr = TO_NATIVE(rela->r_addend); 1506 1507 switch (elf->hdr->e_machine) { 1508 case EM_RISCV: 1509 if (!strcmp("__ex_table", fromsec) && 1510 r_type == R_RISCV_SUB32) 1511 continue; 1512 break; 1513 case EM_LOONGARCH: 1514 if (!strcmp("__ex_table", fromsec) && 1515 r_type == R_LARCH_SUB32) 1516 continue; 1517 break; 1518 } 1519 1520 check_section_mismatch(mod, elf, elf->symtab_start + r_sym, 1521 fsecndx, fromsec, r_offset, taddr); 1522 } 1523 } 1524 1525 static void section_rel(struct module *mod, struct elf_info *elf, 1526 Elf_Shdr *sechdr) 1527 { 1528 Elf_Rel *rel; 1529 unsigned int fsecndx = sechdr->sh_info; 1530 const char *fromsec = sec_name(elf, fsecndx); 1531 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset; 1532 Elf_Rel *stop = (void *)start + sechdr->sh_size; 1533 1534 /* if from section (name) is know good then skip it */ 1535 if (match(fromsec, section_white_list)) 1536 return; 1537 1538 for (rel = start; rel < stop; rel++) { 1539 Elf_Sym *tsym; 1540 Elf_Addr taddr = 0, r_offset; 1541 unsigned int r_type, r_sym; 1542 void *loc; 1543 1544 r_offset = TO_NATIVE(rel->r_offset); 1545 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1546 1547 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1548 tsym = elf->symtab_start + r_sym; 1549 1550 switch (elf->hdr->e_machine) { 1551 case EM_386: 1552 taddr = addend_386_rel(loc, r_type); 1553 break; 1554 case EM_ARM: 1555 taddr = addend_arm_rel(loc, tsym, r_type); 1556 break; 1557 case EM_MIPS: 1558 taddr = addend_mips_rel(loc, r_type); 1559 break; 1560 default: 1561 fatal("Please add code to calculate addend for this architecture\n"); 1562 } 1563 1564 check_section_mismatch(mod, elf, tsym, 1565 fsecndx, fromsec, r_offset, taddr); 1566 } 1567 } 1568 1569 /** 1570 * A module includes a number of sections that are discarded 1571 * either when loaded or when used as built-in. 1572 * For loaded modules all functions marked __init and all data 1573 * marked __initdata will be discarded when the module has been initialized. 1574 * Likewise for modules used built-in the sections marked __exit 1575 * are discarded because __exit marked function are supposed to be called 1576 * only when a module is unloaded which never happens for built-in modules. 1577 * The check_sec_ref() function traverses all relocation records 1578 * to find all references to a section that reference a section that will 1579 * be discarded and warns about it. 1580 **/ 1581 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1582 { 1583 int i; 1584 Elf_Shdr *sechdrs = elf->sechdrs; 1585 1586 /* Walk through all sections */ 1587 for (i = 0; i < elf->num_sections; i++) { 1588 check_section(mod->name, elf, &elf->sechdrs[i]); 1589 /* We want to process only relocation sections and not .init */ 1590 if (sechdrs[i].sh_type == SHT_RELA) 1591 section_rela(mod, elf, &elf->sechdrs[i]); 1592 else if (sechdrs[i].sh_type == SHT_REL) 1593 section_rel(mod, elf, &elf->sechdrs[i]); 1594 } 1595 } 1596 1597 static char *remove_dot(char *s) 1598 { 1599 size_t n = strcspn(s, "."); 1600 1601 if (n && s[n]) { 1602 size_t m = strspn(s + n + 1, "0123456789"); 1603 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1604 s[n] = 0; 1605 } 1606 return s; 1607 } 1608 1609 /* 1610 * The CRCs are recorded in .*.cmd files in the form of: 1611 * #SYMVER <name> <crc> 1612 */ 1613 static void extract_crcs_for_object(const char *object, struct module *mod) 1614 { 1615 char cmd_file[PATH_MAX]; 1616 char *buf, *p; 1617 const char *base; 1618 int dirlen, ret; 1619 1620 base = strrchr(object, '/'); 1621 if (base) { 1622 base++; 1623 dirlen = base - object; 1624 } else { 1625 dirlen = 0; 1626 base = object; 1627 } 1628 1629 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1630 dirlen, object, base); 1631 if (ret >= sizeof(cmd_file)) { 1632 error("%s: too long path was truncated\n", cmd_file); 1633 return; 1634 } 1635 1636 buf = read_text_file(cmd_file); 1637 p = buf; 1638 1639 while ((p = strstr(p, "\n#SYMVER "))) { 1640 char *name; 1641 size_t namelen; 1642 unsigned int crc; 1643 struct symbol *sym; 1644 1645 name = p + strlen("\n#SYMVER "); 1646 1647 p = strchr(name, ' '); 1648 if (!p) 1649 break; 1650 1651 namelen = p - name; 1652 p++; 1653 1654 if (!isdigit(*p)) 1655 continue; /* skip this line */ 1656 1657 crc = strtoul(p, &p, 0); 1658 if (*p != '\n') 1659 continue; /* skip this line */ 1660 1661 name[namelen] = '\0'; 1662 1663 /* 1664 * sym_find_with_module() may return NULL here. 1665 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1666 * Since commit e1327a127703, genksyms calculates CRCs of all 1667 * symbols, including trimmed ones. Ignore orphan CRCs. 1668 */ 1669 sym = sym_find_with_module(name, mod); 1670 if (sym) 1671 sym_set_crc(sym, crc); 1672 } 1673 1674 free(buf); 1675 } 1676 1677 /* 1678 * The symbol versions (CRC) are recorded in the .*.cmd files. 1679 * Parse them to retrieve CRCs for the current module. 1680 */ 1681 static void mod_set_crcs(struct module *mod) 1682 { 1683 char objlist[PATH_MAX]; 1684 char *buf, *p, *obj; 1685 int ret; 1686 1687 if (mod->is_vmlinux) { 1688 strcpy(objlist, ".vmlinux.objs"); 1689 } else { 1690 /* objects for a module are listed in the *.mod file. */ 1691 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1692 if (ret >= sizeof(objlist)) { 1693 error("%s: too long path was truncated\n", objlist); 1694 return; 1695 } 1696 } 1697 1698 buf = read_text_file(objlist); 1699 p = buf; 1700 1701 while ((obj = strsep(&p, "\n")) && obj[0]) 1702 extract_crcs_for_object(obj, mod); 1703 1704 free(buf); 1705 } 1706 1707 static void read_symbols(const char *modname) 1708 { 1709 const char *symname; 1710 char *version; 1711 char *license; 1712 char *namespace; 1713 struct module *mod; 1714 struct elf_info info = { }; 1715 Elf_Sym *sym; 1716 1717 if (!parse_elf(&info, modname)) 1718 return; 1719 1720 if (!strends(modname, ".o")) { 1721 error("%s: filename must be suffixed with .o\n", modname); 1722 return; 1723 } 1724 1725 /* strip trailing .o */ 1726 mod = new_module(modname, strlen(modname) - strlen(".o")); 1727 1728 if (!mod->is_vmlinux) { 1729 license = get_modinfo(&info, "license"); 1730 if (!license) 1731 error("missing MODULE_LICENSE() in %s\n", modname); 1732 while (license) { 1733 if (!license_is_gpl_compatible(license)) { 1734 mod->is_gpl_compatible = false; 1735 break; 1736 } 1737 license = get_next_modinfo(&info, "license", license); 1738 } 1739 1740 namespace = get_modinfo(&info, "import_ns"); 1741 while (namespace) { 1742 add_namespace(&mod->imported_namespaces, namespace); 1743 namespace = get_next_modinfo(&info, "import_ns", 1744 namespace); 1745 } 1746 } 1747 1748 if (extra_warn && !get_modinfo(&info, "description")) 1749 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1750 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1751 symname = remove_dot(info.strtab + sym->st_name); 1752 1753 handle_symbol(mod, &info, sym, symname); 1754 handle_moddevtable(mod, &info, sym, symname); 1755 } 1756 1757 check_sec_ref(mod, &info); 1758 1759 if (!mod->is_vmlinux) { 1760 version = get_modinfo(&info, "version"); 1761 if (version || all_versions) 1762 get_src_version(mod->name, mod->srcversion, 1763 sizeof(mod->srcversion) - 1); 1764 } 1765 1766 parse_elf_finish(&info); 1767 1768 if (modversions) { 1769 /* 1770 * Our trick to get versioning for module struct etc. - it's 1771 * never passed as an argument to an exported function, so 1772 * the automatic versioning doesn't pick it up, but it's really 1773 * important anyhow. 1774 */ 1775 sym_add_unresolved("module_layout", mod, false); 1776 1777 mod_set_crcs(mod); 1778 } 1779 } 1780 1781 static void read_symbols_from_files(const char *filename) 1782 { 1783 FILE *in = stdin; 1784 char fname[PATH_MAX]; 1785 1786 in = fopen(filename, "r"); 1787 if (!in) 1788 fatal("Can't open filenames file %s: %m", filename); 1789 1790 while (fgets(fname, PATH_MAX, in) != NULL) { 1791 if (strends(fname, "\n")) 1792 fname[strlen(fname)-1] = '\0'; 1793 read_symbols(fname); 1794 } 1795 1796 fclose(in); 1797 } 1798 1799 #define SZ 500 1800 1801 /* We first write the generated file into memory using the 1802 * following helper, then compare to the file on disk and 1803 * only update the later if anything changed */ 1804 1805 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1806 const char *fmt, ...) 1807 { 1808 char tmp[SZ]; 1809 int len; 1810 va_list ap; 1811 1812 va_start(ap, fmt); 1813 len = vsnprintf(tmp, SZ, fmt, ap); 1814 buf_write(buf, tmp, len); 1815 va_end(ap); 1816 } 1817 1818 void buf_write(struct buffer *buf, const char *s, int len) 1819 { 1820 if (buf->size - buf->pos < len) { 1821 buf->size += len + SZ; 1822 buf->p = NOFAIL(realloc(buf->p, buf->size)); 1823 } 1824 strncpy(buf->p + buf->pos, s, len); 1825 buf->pos += len; 1826 } 1827 1828 static void check_exports(struct module *mod) 1829 { 1830 struct symbol *s, *exp; 1831 1832 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1833 const char *basename; 1834 exp = find_symbol(s->name); 1835 if (!exp) { 1836 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1837 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, 1838 "\"%s\" [%s.ko] undefined!\n", 1839 s->name, mod->name); 1840 continue; 1841 } 1842 if (exp->module == mod) { 1843 error("\"%s\" [%s.ko] was exported without definition\n", 1844 s->name, mod->name); 1845 continue; 1846 } 1847 1848 exp->used = true; 1849 s->module = exp->module; 1850 s->crc_valid = exp->crc_valid; 1851 s->crc = exp->crc; 1852 1853 basename = strrchr(mod->name, '/'); 1854 if (basename) 1855 basename++; 1856 else 1857 basename = mod->name; 1858 1859 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1860 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, 1861 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1862 basename, exp->name, exp->namespace); 1863 add_namespace(&mod->missing_namespaces, exp->namespace); 1864 } 1865 1866 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1867 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1868 basename, exp->name); 1869 } 1870 } 1871 1872 static void handle_white_list_exports(const char *white_list) 1873 { 1874 char *buf, *p, *name; 1875 1876 buf = read_text_file(white_list); 1877 p = buf; 1878 1879 while ((name = strsep(&p, "\n"))) { 1880 struct symbol *sym = find_symbol(name); 1881 1882 if (sym) 1883 sym->used = true; 1884 } 1885 1886 free(buf); 1887 } 1888 1889 static void check_modname_len(struct module *mod) 1890 { 1891 const char *mod_name; 1892 1893 mod_name = strrchr(mod->name, '/'); 1894 if (mod_name == NULL) 1895 mod_name = mod->name; 1896 else 1897 mod_name++; 1898 if (strlen(mod_name) >= MODULE_NAME_LEN) 1899 error("module name is too long [%s.ko]\n", mod->name); 1900 } 1901 1902 /** 1903 * Header for the generated file 1904 **/ 1905 static void add_header(struct buffer *b, struct module *mod) 1906 { 1907 buf_printf(b, "#include <linux/module.h>\n"); 1908 /* 1909 * Include build-salt.h after module.h in order to 1910 * inherit the definitions. 1911 */ 1912 buf_printf(b, "#define INCLUDE_VERMAGIC\n"); 1913 buf_printf(b, "#include <linux/build-salt.h>\n"); 1914 buf_printf(b, "#include <linux/elfnote-lto.h>\n"); 1915 buf_printf(b, "#include <linux/export-internal.h>\n"); 1916 buf_printf(b, "#include <linux/vermagic.h>\n"); 1917 buf_printf(b, "#include <linux/compiler.h>\n"); 1918 buf_printf(b, "\n"); 1919 buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n"); 1920 buf_printf(b, "#include <asm/orc_header.h>\n"); 1921 buf_printf(b, "ORC_HEADER;\n"); 1922 buf_printf(b, "#endif\n"); 1923 buf_printf(b, "\n"); 1924 buf_printf(b, "BUILD_SALT;\n"); 1925 buf_printf(b, "BUILD_LTO_INFO;\n"); 1926 buf_printf(b, "\n"); 1927 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1928 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1929 buf_printf(b, "\n"); 1930 buf_printf(b, "__visible struct module __this_module\n"); 1931 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1932 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1933 if (mod->has_init) 1934 buf_printf(b, "\t.init = init_module,\n"); 1935 if (mod->has_cleanup) 1936 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1937 "\t.exit = cleanup_module,\n" 1938 "#endif\n"); 1939 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1940 buf_printf(b, "};\n"); 1941 1942 if (!external_module) 1943 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1944 1945 buf_printf(b, 1946 "\n" 1947 "#ifdef CONFIG_RETPOLINE\n" 1948 "MODULE_INFO(retpoline, \"Y\");\n" 1949 "#endif\n"); 1950 1951 if (strstarts(mod->name, "drivers/staging")) 1952 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1953 1954 if (strstarts(mod->name, "tools/testing")) 1955 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1956 } 1957 1958 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1959 { 1960 struct symbol *sym; 1961 1962 /* generate struct for exported symbols */ 1963 buf_printf(buf, "\n"); 1964 list_for_each_entry(sym, &mod->exported_symbols, list) { 1965 if (trim_unused_exports && !sym->used) 1966 continue; 1967 1968 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1969 sym->is_func ? "FUNC" : "DATA", sym->name, 1970 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1971 } 1972 1973 if (!modversions) 1974 return; 1975 1976 /* record CRCs for exported symbols */ 1977 buf_printf(buf, "\n"); 1978 list_for_each_entry(sym, &mod->exported_symbols, list) { 1979 if (trim_unused_exports && !sym->used) 1980 continue; 1981 1982 if (!sym->crc_valid) 1983 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1984 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1985 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1986 sym->name); 1987 1988 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1989 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1990 } 1991 } 1992 1993 /** 1994 * Record CRCs for unresolved symbols 1995 **/ 1996 static void add_versions(struct buffer *b, struct module *mod) 1997 { 1998 struct symbol *s; 1999 2000 if (!modversions) 2001 return; 2002 2003 buf_printf(b, "\n"); 2004 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 2005 buf_printf(b, "__used __section(\"__versions\") = {\n"); 2006 2007 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2008 if (!s->module) 2009 continue; 2010 if (!s->crc_valid) { 2011 warn("\"%s\" [%s.ko] has no CRC!\n", 2012 s->name, mod->name); 2013 continue; 2014 } 2015 if (strlen(s->name) >= MODULE_NAME_LEN) { 2016 error("too long symbol \"%s\" [%s.ko]\n", 2017 s->name, mod->name); 2018 break; 2019 } 2020 buf_printf(b, "\t{ %#8x, \"%s\" },\n", 2021 s->crc, s->name); 2022 } 2023 2024 buf_printf(b, "};\n"); 2025 } 2026 2027 static void add_depends(struct buffer *b, struct module *mod) 2028 { 2029 struct symbol *s; 2030 int first = 1; 2031 2032 /* Clear ->seen flag of modules that own symbols needed by this. */ 2033 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2034 if (s->module) 2035 s->module->seen = s->module->is_vmlinux; 2036 } 2037 2038 buf_printf(b, "\n"); 2039 buf_printf(b, "MODULE_INFO(depends, \""); 2040 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2041 const char *p; 2042 if (!s->module) 2043 continue; 2044 2045 if (s->module->seen) 2046 continue; 2047 2048 s->module->seen = true; 2049 p = strrchr(s->module->name, '/'); 2050 if (p) 2051 p++; 2052 else 2053 p = s->module->name; 2054 buf_printf(b, "%s%s", first ? "" : ",", p); 2055 first = 0; 2056 } 2057 buf_printf(b, "\");\n"); 2058 } 2059 2060 static void add_srcversion(struct buffer *b, struct module *mod) 2061 { 2062 if (mod->srcversion[0]) { 2063 buf_printf(b, "\n"); 2064 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 2065 mod->srcversion); 2066 } 2067 } 2068 2069 static void write_buf(struct buffer *b, const char *fname) 2070 { 2071 FILE *file; 2072 2073 if (error_occurred) 2074 return; 2075 2076 file = fopen(fname, "w"); 2077 if (!file) { 2078 perror(fname); 2079 exit(1); 2080 } 2081 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2082 perror(fname); 2083 exit(1); 2084 } 2085 if (fclose(file) != 0) { 2086 perror(fname); 2087 exit(1); 2088 } 2089 } 2090 2091 static void write_if_changed(struct buffer *b, const char *fname) 2092 { 2093 char *tmp; 2094 FILE *file; 2095 struct stat st; 2096 2097 file = fopen(fname, "r"); 2098 if (!file) 2099 goto write; 2100 2101 if (fstat(fileno(file), &st) < 0) 2102 goto close_write; 2103 2104 if (st.st_size != b->pos) 2105 goto close_write; 2106 2107 tmp = NOFAIL(malloc(b->pos)); 2108 if (fread(tmp, 1, b->pos, file) != b->pos) 2109 goto free_write; 2110 2111 if (memcmp(tmp, b->p, b->pos) != 0) 2112 goto free_write; 2113 2114 free(tmp); 2115 fclose(file); 2116 return; 2117 2118 free_write: 2119 free(tmp); 2120 close_write: 2121 fclose(file); 2122 write: 2123 write_buf(b, fname); 2124 } 2125 2126 static void write_vmlinux_export_c_file(struct module *mod) 2127 { 2128 struct buffer buf = { }; 2129 2130 buf_printf(&buf, 2131 "#include <linux/export-internal.h>\n"); 2132 2133 add_exported_symbols(&buf, mod); 2134 write_if_changed(&buf, ".vmlinux.export.c"); 2135 free(buf.p); 2136 } 2137 2138 /* do sanity checks, and generate *.mod.c file */ 2139 static void write_mod_c_file(struct module *mod) 2140 { 2141 struct buffer buf = { }; 2142 char fname[PATH_MAX]; 2143 int ret; 2144 2145 add_header(&buf, mod); 2146 add_exported_symbols(&buf, mod); 2147 add_versions(&buf, mod); 2148 add_depends(&buf, mod); 2149 add_moddevtable(&buf, mod); 2150 add_srcversion(&buf, mod); 2151 2152 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2153 if (ret >= sizeof(fname)) { 2154 error("%s: too long path was truncated\n", fname); 2155 goto free; 2156 } 2157 2158 write_if_changed(&buf, fname); 2159 2160 free: 2161 free(buf.p); 2162 } 2163 2164 /* parse Module.symvers file. line format: 2165 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2166 **/ 2167 static void read_dump(const char *fname) 2168 { 2169 char *buf, *pos, *line; 2170 2171 buf = read_text_file(fname); 2172 if (!buf) 2173 /* No symbol versions, silently ignore */ 2174 return; 2175 2176 pos = buf; 2177 2178 while ((line = get_line(&pos))) { 2179 char *symname, *namespace, *modname, *d, *export; 2180 unsigned int crc; 2181 struct module *mod; 2182 struct symbol *s; 2183 bool gpl_only; 2184 2185 if (!(symname = strchr(line, '\t'))) 2186 goto fail; 2187 *symname++ = '\0'; 2188 if (!(modname = strchr(symname, '\t'))) 2189 goto fail; 2190 *modname++ = '\0'; 2191 if (!(export = strchr(modname, '\t'))) 2192 goto fail; 2193 *export++ = '\0'; 2194 if (!(namespace = strchr(export, '\t'))) 2195 goto fail; 2196 *namespace++ = '\0'; 2197 2198 crc = strtoul(line, &d, 16); 2199 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2200 goto fail; 2201 2202 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2203 gpl_only = true; 2204 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2205 gpl_only = false; 2206 } else { 2207 error("%s: unknown license %s. skip", symname, export); 2208 continue; 2209 } 2210 2211 mod = find_module(modname); 2212 if (!mod) { 2213 mod = new_module(modname, strlen(modname)); 2214 mod->from_dump = true; 2215 } 2216 s = sym_add_exported(symname, mod, gpl_only, namespace); 2217 sym_set_crc(s, crc); 2218 } 2219 free(buf); 2220 return; 2221 fail: 2222 free(buf); 2223 fatal("parse error in symbol dump file\n"); 2224 } 2225 2226 static void write_dump(const char *fname) 2227 { 2228 struct buffer buf = { }; 2229 struct module *mod; 2230 struct symbol *sym; 2231 2232 list_for_each_entry(mod, &modules, list) { 2233 if (mod->from_dump) 2234 continue; 2235 list_for_each_entry(sym, &mod->exported_symbols, list) { 2236 if (trim_unused_exports && !sym->used) 2237 continue; 2238 2239 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2240 sym->crc, sym->name, mod->name, 2241 sym->is_gpl_only ? "_GPL" : "", 2242 sym->namespace); 2243 } 2244 } 2245 write_buf(&buf, fname); 2246 free(buf.p); 2247 } 2248 2249 static void write_namespace_deps_files(const char *fname) 2250 { 2251 struct module *mod; 2252 struct namespace_list *ns; 2253 struct buffer ns_deps_buf = {}; 2254 2255 list_for_each_entry(mod, &modules, list) { 2256 2257 if (mod->from_dump || list_empty(&mod->missing_namespaces)) 2258 continue; 2259 2260 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2261 2262 list_for_each_entry(ns, &mod->missing_namespaces, list) 2263 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2264 2265 buf_printf(&ns_deps_buf, "\n"); 2266 } 2267 2268 write_if_changed(&ns_deps_buf, fname); 2269 free(ns_deps_buf.p); 2270 } 2271 2272 struct dump_list { 2273 struct list_head list; 2274 const char *file; 2275 }; 2276 2277 int main(int argc, char **argv) 2278 { 2279 struct module *mod; 2280 char *missing_namespace_deps = NULL; 2281 char *unused_exports_white_list = NULL; 2282 char *dump_write = NULL, *files_source = NULL; 2283 int opt; 2284 LIST_HEAD(dump_lists); 2285 struct dump_list *dl, *dl2; 2286 2287 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) { 2288 switch (opt) { 2289 case 'e': 2290 external_module = true; 2291 break; 2292 case 'i': 2293 dl = NOFAIL(malloc(sizeof(*dl))); 2294 dl->file = optarg; 2295 list_add_tail(&dl->list, &dump_lists); 2296 break; 2297 case 'M': 2298 module_enabled = true; 2299 break; 2300 case 'm': 2301 modversions = true; 2302 break; 2303 case 'n': 2304 ignore_missing_files = true; 2305 break; 2306 case 'o': 2307 dump_write = optarg; 2308 break; 2309 case 'a': 2310 all_versions = true; 2311 break; 2312 case 'T': 2313 files_source = optarg; 2314 break; 2315 case 't': 2316 trim_unused_exports = true; 2317 break; 2318 case 'u': 2319 unused_exports_white_list = optarg; 2320 break; 2321 case 'W': 2322 extra_warn = true; 2323 break; 2324 case 'w': 2325 warn_unresolved = true; 2326 break; 2327 case 'E': 2328 sec_mismatch_warn_only = false; 2329 break; 2330 case 'N': 2331 allow_missing_ns_imports = true; 2332 break; 2333 case 'd': 2334 missing_namespace_deps = optarg; 2335 break; 2336 default: 2337 exit(1); 2338 } 2339 } 2340 2341 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2342 read_dump(dl->file); 2343 list_del(&dl->list); 2344 free(dl); 2345 } 2346 2347 while (optind < argc) 2348 read_symbols(argv[optind++]); 2349 2350 if (files_source) 2351 read_symbols_from_files(files_source); 2352 2353 list_for_each_entry(mod, &modules, list) { 2354 if (mod->from_dump || mod->is_vmlinux) 2355 continue; 2356 2357 check_modname_len(mod); 2358 check_exports(mod); 2359 } 2360 2361 if (unused_exports_white_list) 2362 handle_white_list_exports(unused_exports_white_list); 2363 2364 list_for_each_entry(mod, &modules, list) { 2365 if (mod->from_dump) 2366 continue; 2367 2368 if (mod->is_vmlinux) 2369 write_vmlinux_export_c_file(mod); 2370 else 2371 write_mod_c_file(mod); 2372 } 2373 2374 if (missing_namespace_deps) 2375 write_namespace_deps_files(missing_namespace_deps); 2376 2377 if (dump_write) 2378 write_dump(dump_write); 2379 if (sec_mismatch_count && !sec_mismatch_warn_only) 2380 error("Section mismatches detected.\n" 2381 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2382 2383 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2384 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2385 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2386 2387 return error_occurred ? 1 : 0; 2388 } 2389