1 /* Postprocess module symbol versions 2 * 3 * Copyright 2003 Kai Germaschewski 4 * Copyright 2002-2004 Rusty Russell, IBM Corporation 5 * Copyright 2006-2008 Sam Ravnborg 6 * Based in part on module-init-tools/depmod.c,file2alias 7 * 8 * This software may be used and distributed according to the terms 9 * of the GNU General Public License, incorporated herein by reference. 10 * 11 * Usage: modpost vmlinux module1.o module2.o ... 12 */ 13 14 #define _GNU_SOURCE 15 #include <elf.h> 16 #include <fnmatch.h> 17 #include <stdio.h> 18 #include <ctype.h> 19 #include <string.h> 20 #include <limits.h> 21 #include <stdbool.h> 22 #include <errno.h> 23 #include "modpost.h" 24 #include "../../include/linux/license.h" 25 26 static bool module_enabled; 27 /* Are we using CONFIG_MODVERSIONS? */ 28 static bool modversions; 29 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 30 static bool all_versions; 31 /* If we are modposting external module set to 1 */ 32 static bool external_module; 33 /* Only warn about unresolved symbols */ 34 static bool warn_unresolved; 35 36 static int sec_mismatch_count; 37 static bool sec_mismatch_warn_only = true; 38 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */ 39 static bool trim_unused_exports; 40 41 /* ignore missing files */ 42 static bool ignore_missing_files; 43 /* If set to 1, only warn (instead of error) about missing ns imports */ 44 static bool allow_missing_ns_imports; 45 46 static bool error_occurred; 47 48 static bool extra_warn; 49 50 /* 51 * Cut off the warnings when there are too many. This typically occurs when 52 * vmlinux is missing. ('make modules' without building vmlinux.) 53 */ 54 #define MAX_UNRESOLVED_REPORTS 10 55 static unsigned int nr_unresolved; 56 57 /* In kernel, this size is defined in linux/module.h; 58 * here we use Elf_Addr instead of long for covering cross-compile 59 */ 60 61 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) 62 63 void __attribute__((format(printf, 2, 3))) 64 modpost_log(enum loglevel loglevel, const char *fmt, ...) 65 { 66 va_list arglist; 67 68 switch (loglevel) { 69 case LOG_WARN: 70 fprintf(stderr, "WARNING: "); 71 break; 72 case LOG_ERROR: 73 fprintf(stderr, "ERROR: "); 74 break; 75 case LOG_FATAL: 76 fprintf(stderr, "FATAL: "); 77 break; 78 default: /* invalid loglevel, ignore */ 79 break; 80 } 81 82 fprintf(stderr, "modpost: "); 83 84 va_start(arglist, fmt); 85 vfprintf(stderr, fmt, arglist); 86 va_end(arglist); 87 88 if (loglevel == LOG_FATAL) 89 exit(1); 90 if (loglevel == LOG_ERROR) 91 error_occurred = true; 92 } 93 94 static inline bool strends(const char *str, const char *postfix) 95 { 96 if (strlen(str) < strlen(postfix)) 97 return false; 98 99 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; 100 } 101 102 void *do_nofail(void *ptr, const char *expr) 103 { 104 if (!ptr) 105 fatal("Memory allocation failure: %s.\n", expr); 106 107 return ptr; 108 } 109 110 char *read_text_file(const char *filename) 111 { 112 struct stat st; 113 size_t nbytes; 114 int fd; 115 char *buf; 116 117 fd = open(filename, O_RDONLY); 118 if (fd < 0) { 119 perror(filename); 120 exit(1); 121 } 122 123 if (fstat(fd, &st) < 0) { 124 perror(filename); 125 exit(1); 126 } 127 128 buf = NOFAIL(malloc(st.st_size + 1)); 129 130 nbytes = st.st_size; 131 132 while (nbytes) { 133 ssize_t bytes_read; 134 135 bytes_read = read(fd, buf, nbytes); 136 if (bytes_read < 0) { 137 perror(filename); 138 exit(1); 139 } 140 141 nbytes -= bytes_read; 142 } 143 buf[st.st_size] = '\0'; 144 145 close(fd); 146 147 return buf; 148 } 149 150 char *get_line(char **stringp) 151 { 152 char *orig = *stringp, *next; 153 154 /* do not return the unwanted extra line at EOF */ 155 if (!orig || *orig == '\0') 156 return NULL; 157 158 /* don't use strsep here, it is not available everywhere */ 159 next = strchr(orig, '\n'); 160 if (next) 161 *next++ = '\0'; 162 163 *stringp = next; 164 165 return orig; 166 } 167 168 /* A list of all modules we processed */ 169 LIST_HEAD(modules); 170 171 static struct module *find_module(const char *modname) 172 { 173 struct module *mod; 174 175 list_for_each_entry(mod, &modules, list) { 176 if (strcmp(mod->name, modname) == 0) 177 return mod; 178 } 179 return NULL; 180 } 181 182 static struct module *new_module(const char *name, size_t namelen) 183 { 184 struct module *mod; 185 186 mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1)); 187 memset(mod, 0, sizeof(*mod)); 188 189 INIT_LIST_HEAD(&mod->exported_symbols); 190 INIT_LIST_HEAD(&mod->unresolved_symbols); 191 INIT_LIST_HEAD(&mod->missing_namespaces); 192 INIT_LIST_HEAD(&mod->imported_namespaces); 193 194 memcpy(mod->name, name, namelen); 195 mod->name[namelen] = '\0'; 196 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0); 197 198 /* 199 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE() 200 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue 201 * modpost will exit wiht error anyway. 202 */ 203 mod->is_gpl_compatible = true; 204 205 list_add_tail(&mod->list, &modules); 206 207 return mod; 208 } 209 210 /* A hash of all exported symbols, 211 * struct symbol is also used for lists of unresolved symbols */ 212 213 #define SYMBOL_HASH_SIZE 1024 214 215 struct symbol { 216 struct symbol *next; 217 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */ 218 struct module *module; 219 char *namespace; 220 unsigned int crc; 221 bool crc_valid; 222 bool weak; 223 bool is_func; 224 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ 225 bool used; /* there exists a user of this symbol */ 226 char name[]; 227 }; 228 229 static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 230 231 /* This is based on the hash algorithm from gdbm, via tdb */ 232 static inline unsigned int tdb_hash(const char *name) 233 { 234 unsigned value; /* Used to compute the hash value. */ 235 unsigned i; /* Used to cycle through random values. */ 236 237 /* Set the initial value from the key size. */ 238 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++) 239 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 240 241 return (1103515243 * value + 12345); 242 } 243 244 /** 245 * Allocate a new symbols for use in the hash of exported symbols or 246 * the list of unresolved symbols per module 247 **/ 248 static struct symbol *alloc_symbol(const char *name) 249 { 250 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 251 252 memset(s, 0, sizeof(*s)); 253 strcpy(s->name, name); 254 255 return s; 256 } 257 258 /* For the hash of exported symbols */ 259 static void hash_add_symbol(struct symbol *sym) 260 { 261 unsigned int hash; 262 263 hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE; 264 sym->next = symbolhash[hash]; 265 symbolhash[hash] = sym; 266 } 267 268 static void sym_add_unresolved(const char *name, struct module *mod, bool weak) 269 { 270 struct symbol *sym; 271 272 sym = alloc_symbol(name); 273 sym->weak = weak; 274 275 list_add_tail(&sym->list, &mod->unresolved_symbols); 276 } 277 278 static struct symbol *sym_find_with_module(const char *name, struct module *mod) 279 { 280 struct symbol *s; 281 282 /* For our purposes, .foo matches foo. PPC64 needs this. */ 283 if (name[0] == '.') 284 name++; 285 286 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) { 287 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) 288 return s; 289 } 290 return NULL; 291 } 292 293 static struct symbol *find_symbol(const char *name) 294 { 295 return sym_find_with_module(name, NULL); 296 } 297 298 struct namespace_list { 299 struct list_head list; 300 char namespace[]; 301 }; 302 303 static bool contains_namespace(struct list_head *head, const char *namespace) 304 { 305 struct namespace_list *list; 306 307 /* 308 * The default namespace is null string "", which is always implicitly 309 * contained. 310 */ 311 if (!namespace[0]) 312 return true; 313 314 list_for_each_entry(list, head, list) { 315 if (!strcmp(list->namespace, namespace)) 316 return true; 317 } 318 319 return false; 320 } 321 322 static void add_namespace(struct list_head *head, const char *namespace) 323 { 324 struct namespace_list *ns_entry; 325 326 if (!contains_namespace(head, namespace)) { 327 ns_entry = NOFAIL(malloc(sizeof(*ns_entry) + 328 strlen(namespace) + 1)); 329 strcpy(ns_entry->namespace, namespace); 330 list_add_tail(&ns_entry->list, head); 331 } 332 } 333 334 static void *sym_get_data_by_offset(const struct elf_info *info, 335 unsigned int secindex, unsigned long offset) 336 { 337 Elf_Shdr *sechdr = &info->sechdrs[secindex]; 338 339 return (void *)info->hdr + sechdr->sh_offset + offset; 340 } 341 342 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) 343 { 344 return sym_get_data_by_offset(info, get_secindex(info, sym), 345 sym->st_value); 346 } 347 348 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) 349 { 350 return sym_get_data_by_offset(info, info->secindex_strings, 351 sechdr->sh_name); 352 } 353 354 static const char *sec_name(const struct elf_info *info, unsigned int secindex) 355 { 356 /* 357 * If sym->st_shndx is a special section index, there is no 358 * corresponding section header. 359 * Return "" if the index is out of range of info->sechdrs[] array. 360 */ 361 if (secindex >= info->num_sections) 362 return ""; 363 364 return sech_name(info, &info->sechdrs[secindex]); 365 } 366 367 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) 368 369 static struct symbol *sym_add_exported(const char *name, struct module *mod, 370 bool gpl_only, const char *namespace) 371 { 372 struct symbol *s = find_symbol(name); 373 374 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { 375 error("%s: '%s' exported twice. Previous export was in %s%s\n", 376 mod->name, name, s->module->name, 377 s->module->is_vmlinux ? "" : ".ko"); 378 } 379 380 s = alloc_symbol(name); 381 s->module = mod; 382 s->is_gpl_only = gpl_only; 383 s->namespace = NOFAIL(strdup(namespace)); 384 list_add_tail(&s->list, &mod->exported_symbols); 385 hash_add_symbol(s); 386 387 return s; 388 } 389 390 static void sym_set_crc(struct symbol *sym, unsigned int crc) 391 { 392 sym->crc = crc; 393 sym->crc_valid = true; 394 } 395 396 static void *grab_file(const char *filename, size_t *size) 397 { 398 struct stat st; 399 void *map = MAP_FAILED; 400 int fd; 401 402 fd = open(filename, O_RDONLY); 403 if (fd < 0) 404 return NULL; 405 if (fstat(fd, &st)) 406 goto failed; 407 408 *size = st.st_size; 409 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 410 411 failed: 412 close(fd); 413 if (map == MAP_FAILED) 414 return NULL; 415 return map; 416 } 417 418 static void release_file(void *file, size_t size) 419 { 420 munmap(file, size); 421 } 422 423 static int parse_elf(struct elf_info *info, const char *filename) 424 { 425 unsigned int i; 426 Elf_Ehdr *hdr; 427 Elf_Shdr *sechdrs; 428 Elf_Sym *sym; 429 const char *secstrings; 430 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 431 432 hdr = grab_file(filename, &info->size); 433 if (!hdr) { 434 if (ignore_missing_files) { 435 fprintf(stderr, "%s: %s (ignored)\n", filename, 436 strerror(errno)); 437 return 0; 438 } 439 perror(filename); 440 exit(1); 441 } 442 info->hdr = hdr; 443 if (info->size < sizeof(*hdr)) { 444 /* file too small, assume this is an empty .o file */ 445 return 0; 446 } 447 /* Is this a valid ELF file? */ 448 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 449 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 450 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 451 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 452 /* Not an ELF file - silently ignore it */ 453 return 0; 454 } 455 /* Fix endianness in ELF header */ 456 hdr->e_type = TO_NATIVE(hdr->e_type); 457 hdr->e_machine = TO_NATIVE(hdr->e_machine); 458 hdr->e_version = TO_NATIVE(hdr->e_version); 459 hdr->e_entry = TO_NATIVE(hdr->e_entry); 460 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 461 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 462 hdr->e_flags = TO_NATIVE(hdr->e_flags); 463 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 464 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 465 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 466 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 467 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 468 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 469 sechdrs = (void *)hdr + hdr->e_shoff; 470 info->sechdrs = sechdrs; 471 472 /* modpost only works for relocatable objects */ 473 if (hdr->e_type != ET_REL) 474 fatal("%s: not relocatable object.", filename); 475 476 /* Check if file offset is correct */ 477 if (hdr->e_shoff > info->size) { 478 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", 479 (unsigned long)hdr->e_shoff, filename, info->size); 480 return 0; 481 } 482 483 if (hdr->e_shnum == SHN_UNDEF) { 484 /* 485 * There are more than 64k sections, 486 * read count from .sh_size. 487 */ 488 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 489 } 490 else { 491 info->num_sections = hdr->e_shnum; 492 } 493 if (hdr->e_shstrndx == SHN_XINDEX) { 494 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 495 } 496 else { 497 info->secindex_strings = hdr->e_shstrndx; 498 } 499 500 /* Fix endianness in section headers */ 501 for (i = 0; i < info->num_sections; i++) { 502 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 503 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 504 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 505 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 506 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 507 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 508 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 509 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 510 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 511 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 512 } 513 /* Find symbol table. */ 514 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 515 for (i = 1; i < info->num_sections; i++) { 516 const char *secname; 517 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 518 519 if (!nobits && sechdrs[i].sh_offset > info->size) { 520 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n", 521 filename, (unsigned long)sechdrs[i].sh_offset, 522 sizeof(*hdr)); 523 return 0; 524 } 525 secname = secstrings + sechdrs[i].sh_name; 526 if (strcmp(secname, ".modinfo") == 0) { 527 if (nobits) 528 fatal("%s has NOBITS .modinfo\n", filename); 529 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 530 info->modinfo_len = sechdrs[i].sh_size; 531 } else if (!strcmp(secname, ".export_symbol")) { 532 info->export_symbol_secndx = i; 533 } 534 535 if (sechdrs[i].sh_type == SHT_SYMTAB) { 536 unsigned int sh_link_idx; 537 symtab_idx = i; 538 info->symtab_start = (void *)hdr + 539 sechdrs[i].sh_offset; 540 info->symtab_stop = (void *)hdr + 541 sechdrs[i].sh_offset + sechdrs[i].sh_size; 542 sh_link_idx = sechdrs[i].sh_link; 543 info->strtab = (void *)hdr + 544 sechdrs[sh_link_idx].sh_offset; 545 } 546 547 /* 32bit section no. table? ("more than 64k sections") */ 548 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 549 symtab_shndx_idx = i; 550 info->symtab_shndx_start = (void *)hdr + 551 sechdrs[i].sh_offset; 552 info->symtab_shndx_stop = (void *)hdr + 553 sechdrs[i].sh_offset + sechdrs[i].sh_size; 554 } 555 } 556 if (!info->symtab_start) 557 fatal("%s has no symtab?\n", filename); 558 559 /* Fix endianness in symbols */ 560 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 561 sym->st_shndx = TO_NATIVE(sym->st_shndx); 562 sym->st_name = TO_NATIVE(sym->st_name); 563 sym->st_value = TO_NATIVE(sym->st_value); 564 sym->st_size = TO_NATIVE(sym->st_size); 565 } 566 567 if (symtab_shndx_idx != ~0U) { 568 Elf32_Word *p; 569 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 570 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 571 filename, sechdrs[symtab_shndx_idx].sh_link, 572 symtab_idx); 573 /* Fix endianness */ 574 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 575 p++) 576 *p = TO_NATIVE(*p); 577 } 578 579 symsearch_init(info); 580 581 return 1; 582 } 583 584 static void parse_elf_finish(struct elf_info *info) 585 { 586 symsearch_finish(info); 587 release_file(info->hdr, info->size); 588 } 589 590 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 591 { 592 /* ignore __this_module, it will be resolved shortly */ 593 if (strcmp(symname, "__this_module") == 0) 594 return 1; 595 /* ignore global offset table */ 596 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 597 return 1; 598 if (info->hdr->e_machine == EM_PPC) 599 /* Special register function linked on all modules during final link of .ko */ 600 if (strstarts(symname, "_restgpr_") || 601 strstarts(symname, "_savegpr_") || 602 strstarts(symname, "_rest32gpr_") || 603 strstarts(symname, "_save32gpr_") || 604 strstarts(symname, "_restvr_") || 605 strstarts(symname, "_savevr_")) 606 return 1; 607 if (info->hdr->e_machine == EM_PPC64) 608 /* Special register function linked on all modules during final link of .ko */ 609 if (strstarts(symname, "_restgpr0_") || 610 strstarts(symname, "_savegpr0_") || 611 strstarts(symname, "_restvr_") || 612 strstarts(symname, "_savevr_") || 613 strcmp(symname, ".TOC.") == 0) 614 return 1; 615 616 if (info->hdr->e_machine == EM_S390) 617 /* Expoline thunks are linked on all kernel modules during final link of .ko */ 618 if (strstarts(symname, "__s390_indirect_jump_r")) 619 return 1; 620 /* Do not ignore this symbol */ 621 return 0; 622 } 623 624 static void handle_symbol(struct module *mod, struct elf_info *info, 625 const Elf_Sym *sym, const char *symname) 626 { 627 switch (sym->st_shndx) { 628 case SHN_COMMON: 629 if (strstarts(symname, "__gnu_lto_")) { 630 /* Should warn here, but modpost runs before the linker */ 631 } else 632 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 633 break; 634 case SHN_UNDEF: 635 /* undefined symbol */ 636 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 637 ELF_ST_BIND(sym->st_info) != STB_WEAK) 638 break; 639 if (ignore_undef_symbol(info, symname)) 640 break; 641 if (info->hdr->e_machine == EM_SPARC || 642 info->hdr->e_machine == EM_SPARCV9) { 643 /* Ignore register directives. */ 644 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 645 break; 646 if (symname[0] == '.') { 647 char *munged = NOFAIL(strdup(symname)); 648 munged[0] = '_'; 649 munged[1] = toupper(munged[1]); 650 symname = munged; 651 } 652 } 653 654 sym_add_unresolved(symname, mod, 655 ELF_ST_BIND(sym->st_info) == STB_WEAK); 656 break; 657 default: 658 if (strcmp(symname, "init_module") == 0) 659 mod->has_init = true; 660 if (strcmp(symname, "cleanup_module") == 0) 661 mod->has_cleanup = true; 662 break; 663 } 664 } 665 666 /** 667 * Parse tag=value strings from .modinfo section 668 **/ 669 static char *next_string(char *string, unsigned long *secsize) 670 { 671 /* Skip non-zero chars */ 672 while (string[0]) { 673 string++; 674 if ((*secsize)-- <= 1) 675 return NULL; 676 } 677 678 /* Skip any zero padding. */ 679 while (!string[0]) { 680 string++; 681 if ((*secsize)-- <= 1) 682 return NULL; 683 } 684 return string; 685 } 686 687 static char *get_next_modinfo(struct elf_info *info, const char *tag, 688 char *prev) 689 { 690 char *p; 691 unsigned int taglen = strlen(tag); 692 char *modinfo = info->modinfo; 693 unsigned long size = info->modinfo_len; 694 695 if (prev) { 696 size -= prev - modinfo; 697 modinfo = next_string(prev, &size); 698 } 699 700 for (p = modinfo; p; p = next_string(p, &size)) { 701 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 702 return p + taglen + 1; 703 } 704 return NULL; 705 } 706 707 static char *get_modinfo(struct elf_info *info, const char *tag) 708 709 { 710 return get_next_modinfo(info, tag, NULL); 711 } 712 713 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 714 { 715 if (sym) 716 return elf->strtab + sym->st_name; 717 else 718 return "(unknown)"; 719 } 720 721 /* 722 * Check whether the 'string' argument matches one of the 'patterns', 723 * an array of shell wildcard patterns (glob). 724 * 725 * Return true is there is a match. 726 */ 727 static bool match(const char *string, const char *const patterns[]) 728 { 729 const char *pattern; 730 731 while ((pattern = *patterns++)) { 732 if (!fnmatch(pattern, string, 0)) 733 return true; 734 } 735 736 return false; 737 } 738 739 /* useful to pass patterns to match() directly */ 740 #define PATTERNS(...) \ 741 ({ \ 742 static const char *const patterns[] = {__VA_ARGS__, NULL}; \ 743 patterns; \ 744 }) 745 746 /* sections that we do not want to do full section mismatch check on */ 747 static const char *const section_white_list[] = 748 { 749 ".comment*", 750 ".debug*", 751 ".zdebug*", /* Compressed debug sections. */ 752 ".GCC.command.line", /* record-gcc-switches */ 753 ".mdebug*", /* alpha, score, mips etc. */ 754 ".pdr", /* alpha, score, mips etc. */ 755 ".stab*", 756 ".note*", 757 ".got*", 758 ".toc*", 759 ".xt.prop", /* xtensa */ 760 ".xt.lit", /* xtensa */ 761 ".arcextmap*", /* arc */ 762 ".gnu.linkonce.arcext*", /* arc : modules */ 763 ".cmem*", /* EZchip */ 764 ".fmt_slot*", /* EZchip */ 765 ".gnu.lto*", 766 ".discard.*", 767 ".llvm.call-graph-profile", /* call graph */ 768 NULL 769 }; 770 771 /* 772 * This is used to find sections missing the SHF_ALLOC flag. 773 * The cause of this is often a section specified in assembler 774 * without "ax" / "aw". 775 */ 776 static void check_section(const char *modname, struct elf_info *elf, 777 Elf_Shdr *sechdr) 778 { 779 const char *sec = sech_name(elf, sechdr); 780 781 if (sechdr->sh_type == SHT_PROGBITS && 782 !(sechdr->sh_flags & SHF_ALLOC) && 783 !match(sec, section_white_list)) { 784 warn("%s (%s): unexpected non-allocatable section.\n" 785 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 786 "Note that for example <linux/init.h> contains\n" 787 "section definitions for use in .S files.\n\n", 788 modname, sec); 789 } 790 } 791 792 793 794 #define ALL_INIT_DATA_SECTIONS \ 795 ".init.setup", ".init.rodata", ".meminit.rodata", \ 796 ".init.data", ".meminit.data" 797 #define ALL_EXIT_DATA_SECTIONS \ 798 ".exit.data", ".memexit.data" 799 800 #define ALL_INIT_TEXT_SECTIONS \ 801 ".init.text", ".meminit.text" 802 #define ALL_EXIT_TEXT_SECTIONS \ 803 ".exit.text" 804 805 #define ALL_PCI_INIT_SECTIONS \ 806 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 807 ".pci_fixup_enable", ".pci_fixup_resume", \ 808 ".pci_fixup_resume_early", ".pci_fixup_suspend" 809 810 #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS 811 812 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 813 #define ALL_EXIT_SECTIONS EXIT_SECTIONS 814 815 #define DATA_SECTIONS ".data", ".data.rel" 816 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ 817 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \ 818 ".ltext", ".ltext.*" 819 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ 820 ".fixup", ".entry.text", ".exception.text", \ 821 ".coldtext", ".softirqentry.text" 822 823 #define INIT_SECTIONS ".init.*" 824 #define MEM_INIT_SECTIONS ".meminit.*" 825 826 #define EXIT_SECTIONS ".exit.*" 827 828 #define ALL_TEXT_SECTIONS ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \ 829 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 830 831 enum mismatch { 832 TEXT_TO_ANY_INIT, 833 DATA_TO_ANY_INIT, 834 TEXTDATA_TO_ANY_EXIT, 835 XXXINIT_TO_SOME_INIT, 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 use exit code/data from init code */ 887 { 888 .fromsec = { ALL_INIT_SECTIONS, NULL }, 889 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 890 .mismatch = ANY_INIT_TO_ANY_EXIT, 891 }, 892 /* Do not use init code/data from exit code */ 893 { 894 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 895 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 896 .mismatch = ANY_EXIT_TO_ANY_INIT, 897 }, 898 { 899 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 900 .bad_tosec = { INIT_SECTIONS, NULL }, 901 .mismatch = ANY_INIT_TO_ANY_EXIT, 902 }, 903 { 904 .fromsec = { "__ex_table", NULL }, 905 /* If you're adding any new black-listed sections in here, consider 906 * adding a special 'printer' for them in scripts/check_extable. 907 */ 908 .bad_tosec = { ".altinstr_replacement", NULL }, 909 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 910 .mismatch = EXTABLE_TO_NON_TEXT, 911 } 912 }; 913 914 static const struct sectioncheck *section_mismatch( 915 const char *fromsec, const char *tosec) 916 { 917 int i; 918 919 /* 920 * The target section could be the SHT_NUL section when we're 921 * handling relocations to un-resolved symbols, trying to match it 922 * doesn't make much sense and causes build failures on parisc 923 * architectures. 924 */ 925 if (*tosec == '\0') 926 return NULL; 927 928 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 929 const struct sectioncheck *check = §ioncheck[i]; 930 931 if (match(fromsec, check->fromsec)) { 932 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 933 return check; 934 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 935 return check; 936 } 937 } 938 return NULL; 939 } 940 941 /** 942 * Whitelist to allow certain references to pass with no warning. 943 * 944 * Pattern 1: 945 * If a module parameter is declared __initdata and permissions=0 946 * then this is legal despite the warning generated. 947 * We cannot see value of permissions here, so just ignore 948 * this pattern. 949 * The pattern is identified by: 950 * tosec = .init.data 951 * fromsec = .data* 952 * atsym =__param* 953 * 954 * Pattern 1a: 955 * module_param_call() ops can refer to __init set function if permissions=0 956 * The pattern is identified by: 957 * tosec = .init.text 958 * fromsec = .data* 959 * atsym = __param_ops_* 960 * 961 * Pattern 3: 962 * Whitelist all references from .head.text to any init section 963 * 964 * Pattern 4: 965 * Some symbols belong to init section but still it is ok to reference 966 * these from non-init sections as these symbols don't have any memory 967 * allocated for them and symbol address and value are same. So even 968 * if init section is freed, its ok to reference those symbols. 969 * For ex. symbols marking the init section boundaries. 970 * This pattern is identified by 971 * refsymname = __init_begin, _sinittext, _einittext 972 * 973 * Pattern 5: 974 * GCC may optimize static inlines when fed constant arg(s) resulting 975 * in functions like cpumask_empty() -- generating an associated symbol 976 * cpumask_empty.constprop.3 that appears in the audit. If the const that 977 * is passed in comes from __init, like say nmi_ipi_mask, we get a 978 * meaningless section warning. May need to add isra symbols too... 979 * This pattern is identified by 980 * tosec = init section 981 * fromsec = text section 982 * refsymname = *.constprop.* 983 * 984 **/ 985 static int secref_whitelist(const char *fromsec, const char *fromsym, 986 const char *tosec, const char *tosym) 987 { 988 /* Check for pattern 1 */ 989 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 990 match(fromsec, PATTERNS(DATA_SECTIONS)) && 991 strstarts(fromsym, "__param")) 992 return 0; 993 994 /* Check for pattern 1a */ 995 if (strcmp(tosec, ".init.text") == 0 && 996 match(fromsec, PATTERNS(DATA_SECTIONS)) && 997 strstarts(fromsym, "__param_ops_")) 998 return 0; 999 1000 /* symbols in data sections that may refer to any init/exit sections */ 1001 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 1002 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 1003 match(fromsym, PATTERNS("*_template", // scsi uses *_template a lot 1004 "*_timer", // arm uses ops structures named _timer a lot 1005 "*_sht", // scsi also used *_sht to some extent 1006 "*_ops", 1007 "*_probe", 1008 "*_probe_one", 1009 "*_console"))) 1010 return 0; 1011 1012 /* symbols in data sections that may refer to meminit sections */ 1013 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 1014 match(tosec, PATTERNS(ALL_XXXINIT_SECTIONS)) && 1015 match(fromsym, PATTERNS("*driver"))) 1016 return 0; 1017 1018 /* 1019 * symbols in data sections must not refer to .exit.*, but there are 1020 * quite a few offenders, so hide these unless for W=1 builds until 1021 * these are fixed. 1022 */ 1023 if (!extra_warn && 1024 match(fromsec, PATTERNS(DATA_SECTIONS)) && 1025 match(tosec, PATTERNS(EXIT_SECTIONS)) && 1026 match(fromsym, PATTERNS("*driver"))) 1027 return 0; 1028 1029 /* Check for pattern 3 */ 1030 if (strstarts(fromsec, ".head.text") && 1031 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 1032 return 0; 1033 1034 /* Check for pattern 4 */ 1035 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 1036 return 0; 1037 1038 /* Check for pattern 5 */ 1039 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 1040 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 1041 match(fromsym, PATTERNS("*.constprop.*"))) 1042 return 0; 1043 1044 return 1; 1045 } 1046 1047 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 1048 unsigned int secndx) 1049 { 1050 return symsearch_find_nearest(elf, addr, secndx, false, ~0); 1051 } 1052 1053 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 1054 { 1055 Elf_Sym *new_sym; 1056 1057 /* If the supplied symbol has a valid name, return it */ 1058 if (is_valid_name(elf, sym)) 1059 return sym; 1060 1061 /* 1062 * Strive to find a better symbol name, but the resulting name may not 1063 * match the symbol referenced in the original code. 1064 */ 1065 new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym), 1066 true, 20); 1067 return new_sym ? new_sym : sym; 1068 } 1069 1070 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1071 { 1072 if (secndx >= elf->num_sections) 1073 return false; 1074 1075 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1076 } 1077 1078 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1079 const struct sectioncheck* const mismatch, 1080 Elf_Sym *tsym, 1081 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1082 const char *tosec, Elf_Addr taddr) 1083 { 1084 Elf_Sym *from; 1085 const char *tosym; 1086 const char *fromsym; 1087 1088 from = find_fromsym(elf, faddr, fsecndx); 1089 fromsym = sym_name(elf, from); 1090 1091 tsym = find_tosym(elf, taddr, tsym); 1092 tosym = sym_name(elf, tsym); 1093 1094 /* check whitelist - we may ignore it */ 1095 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1096 return; 1097 1098 sec_mismatch_count++; 1099 1100 warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n", 1101 modname, fromsym, 1102 (unsigned int)(faddr - (from ? from->st_value : 0)), 1103 fromsec, tosym, tosec); 1104 1105 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1106 if (match(tosec, mismatch->bad_tosec)) 1107 fatal("The relocation at %s+0x%lx references\n" 1108 "section \"%s\" which is black-listed.\n" 1109 "Something is seriously wrong and should be fixed.\n" 1110 "You might get more information about where this is\n" 1111 "coming from by using scripts/check_extable.sh %s\n", 1112 fromsec, (long)faddr, tosec, modname); 1113 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1114 warn("The relocation at %s+0x%lx references\n" 1115 "section \"%s\" which is not in the list of\n" 1116 "authorized sections. If you're adding a new section\n" 1117 "and/or if this reference is valid, add \"%s\" to the\n" 1118 "list of authorized sections to jump to on fault.\n" 1119 "This can be achieved by adding \"%s\" to\n" 1120 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1121 fromsec, (long)faddr, tosec, tosec, tosec); 1122 else 1123 error("%s+0x%lx references non-executable section '%s'\n", 1124 fromsec, (long)faddr, tosec); 1125 } 1126 } 1127 1128 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1129 Elf_Addr faddr, const char *secname, 1130 Elf_Sym *sym) 1131 { 1132 static const char *prefix = "__export_symbol_"; 1133 const char *label_name, *name, *data; 1134 Elf_Sym *label; 1135 struct symbol *s; 1136 bool is_gpl; 1137 1138 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1139 label_name = sym_name(elf, label); 1140 1141 if (!strstarts(label_name, prefix)) { 1142 error("%s: .export_symbol section contains strange symbol '%s'\n", 1143 mod->name, label_name); 1144 return; 1145 } 1146 1147 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1148 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1149 error("%s: local symbol '%s' was exported\n", mod->name, 1150 label_name + strlen(prefix)); 1151 return; 1152 } 1153 1154 name = sym_name(elf, sym); 1155 if (strcmp(label_name + strlen(prefix), name)) { 1156 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1157 mod->name, name); 1158 return; 1159 } 1160 1161 data = sym_get_data(elf, label); /* license */ 1162 if (!strcmp(data, "GPL")) { 1163 is_gpl = true; 1164 } else if (!strcmp(data, "")) { 1165 is_gpl = false; 1166 } else { 1167 error("%s: unknown license '%s' was specified for '%s'\n", 1168 mod->name, data, name); 1169 return; 1170 } 1171 1172 data += strlen(data) + 1; /* namespace */ 1173 s = sym_add_exported(name, mod, is_gpl, data); 1174 1175 /* 1176 * We need to be aware whether we are exporting a function or 1177 * a data on some architectures. 1178 */ 1179 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1180 1181 /* 1182 * For parisc64, symbols prefixed $$ from the library have the symbol type 1183 * STT_LOPROC. They should be handled as functions too. 1184 */ 1185 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1186 elf->hdr->e_machine == EM_PARISC && 1187 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1188 s->is_func = true; 1189 1190 if (match(secname, PATTERNS(INIT_SECTIONS))) 1191 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1192 mod->name, name); 1193 else if (match(secname, PATTERNS(EXIT_SECTIONS))) 1194 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1195 mod->name, name); 1196 } 1197 1198 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1199 Elf_Sym *sym, 1200 unsigned int fsecndx, const char *fromsec, 1201 Elf_Addr faddr, Elf_Addr taddr) 1202 { 1203 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1204 const struct sectioncheck *mismatch; 1205 1206 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1207 check_export_symbol(mod, elf, faddr, tosec, sym); 1208 return; 1209 } 1210 1211 mismatch = section_mismatch(fromsec, tosec); 1212 if (!mismatch) 1213 return; 1214 1215 default_mismatch_handler(mod->name, elf, mismatch, sym, 1216 fsecndx, fromsec, faddr, 1217 tosec, taddr); 1218 } 1219 1220 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1221 { 1222 switch (r_type) { 1223 case R_386_32: 1224 return TO_NATIVE(*location); 1225 case R_386_PC32: 1226 return TO_NATIVE(*location) + 4; 1227 } 1228 1229 return (Elf_Addr)(-1); 1230 } 1231 1232 #ifndef R_ARM_CALL 1233 #define R_ARM_CALL 28 1234 #endif 1235 #ifndef R_ARM_JUMP24 1236 #define R_ARM_JUMP24 29 1237 #endif 1238 1239 #ifndef R_ARM_THM_CALL 1240 #define R_ARM_THM_CALL 10 1241 #endif 1242 #ifndef R_ARM_THM_JUMP24 1243 #define R_ARM_THM_JUMP24 30 1244 #endif 1245 1246 #ifndef R_ARM_MOVW_ABS_NC 1247 #define R_ARM_MOVW_ABS_NC 43 1248 #endif 1249 1250 #ifndef R_ARM_MOVT_ABS 1251 #define R_ARM_MOVT_ABS 44 1252 #endif 1253 1254 #ifndef R_ARM_THM_MOVW_ABS_NC 1255 #define R_ARM_THM_MOVW_ABS_NC 47 1256 #endif 1257 1258 #ifndef R_ARM_THM_MOVT_ABS 1259 #define R_ARM_THM_MOVT_ABS 48 1260 #endif 1261 1262 #ifndef R_ARM_THM_JUMP19 1263 #define R_ARM_THM_JUMP19 51 1264 #endif 1265 1266 static int32_t sign_extend32(int32_t value, int index) 1267 { 1268 uint8_t shift = 31 - index; 1269 1270 return (int32_t)(value << shift) >> shift; 1271 } 1272 1273 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1274 { 1275 uint32_t inst, upper, lower, sign, j1, j2; 1276 int32_t offset; 1277 1278 switch (r_type) { 1279 case R_ARM_ABS32: 1280 case R_ARM_REL32: 1281 inst = TO_NATIVE(*(uint32_t *)loc); 1282 return inst + sym->st_value; 1283 case R_ARM_MOVW_ABS_NC: 1284 case R_ARM_MOVT_ABS: 1285 inst = TO_NATIVE(*(uint32_t *)loc); 1286 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1287 15); 1288 return offset + sym->st_value; 1289 case R_ARM_PC24: 1290 case R_ARM_CALL: 1291 case R_ARM_JUMP24: 1292 inst = TO_NATIVE(*(uint32_t *)loc); 1293 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1294 return offset + sym->st_value + 8; 1295 case R_ARM_THM_MOVW_ABS_NC: 1296 case R_ARM_THM_MOVT_ABS: 1297 upper = TO_NATIVE(*(uint16_t *)loc); 1298 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1299 offset = sign_extend32(((upper & 0x000f) << 12) | 1300 ((upper & 0x0400) << 1) | 1301 ((lower & 0x7000) >> 4) | 1302 (lower & 0x00ff), 1303 15); 1304 return offset + sym->st_value; 1305 case R_ARM_THM_JUMP19: 1306 /* 1307 * Encoding T3: 1308 * S = upper[10] 1309 * imm6 = upper[5:0] 1310 * J1 = lower[13] 1311 * J2 = lower[11] 1312 * imm11 = lower[10:0] 1313 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1314 */ 1315 upper = TO_NATIVE(*(uint16_t *)loc); 1316 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1317 1318 sign = (upper >> 10) & 1; 1319 j1 = (lower >> 13) & 1; 1320 j2 = (lower >> 11) & 1; 1321 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1322 ((upper & 0x03f) << 12) | 1323 ((lower & 0x07ff) << 1), 1324 20); 1325 return offset + sym->st_value + 4; 1326 case R_ARM_THM_CALL: 1327 case R_ARM_THM_JUMP24: 1328 /* 1329 * Encoding T4: 1330 * S = upper[10] 1331 * imm10 = upper[9:0] 1332 * J1 = lower[13] 1333 * J2 = lower[11] 1334 * imm11 = lower[10:0] 1335 * I1 = NOT(J1 XOR S) 1336 * I2 = NOT(J2 XOR S) 1337 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1338 */ 1339 upper = TO_NATIVE(*(uint16_t *)loc); 1340 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1341 1342 sign = (upper >> 10) & 1; 1343 j1 = (lower >> 13) & 1; 1344 j2 = (lower >> 11) & 1; 1345 offset = sign_extend32((sign << 24) | 1346 ((~(j1 ^ sign) & 1) << 23) | 1347 ((~(j2 ^ sign) & 1) << 22) | 1348 ((upper & 0x03ff) << 12) | 1349 ((lower & 0x07ff) << 1), 1350 24); 1351 return offset + sym->st_value + 4; 1352 } 1353 1354 return (Elf_Addr)(-1); 1355 } 1356 1357 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1358 { 1359 uint32_t inst; 1360 1361 inst = TO_NATIVE(*location); 1362 switch (r_type) { 1363 case R_MIPS_LO16: 1364 return inst & 0xffff; 1365 case R_MIPS_26: 1366 return (inst & 0x03ffffff) << 2; 1367 case R_MIPS_32: 1368 return inst; 1369 } 1370 return (Elf_Addr)(-1); 1371 } 1372 1373 #ifndef EM_RISCV 1374 #define EM_RISCV 243 1375 #endif 1376 1377 #ifndef R_RISCV_SUB32 1378 #define R_RISCV_SUB32 39 1379 #endif 1380 1381 #ifndef EM_LOONGARCH 1382 #define EM_LOONGARCH 258 1383 #endif 1384 1385 #ifndef R_LARCH_SUB32 1386 #define R_LARCH_SUB32 55 1387 #endif 1388 1389 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1390 unsigned int *r_type, unsigned int *r_sym) 1391 { 1392 typedef struct { 1393 Elf64_Word r_sym; /* Symbol index */ 1394 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1395 unsigned char r_type3; /* 3rd relocation type */ 1396 unsigned char r_type2; /* 2nd relocation type */ 1397 unsigned char r_type; /* 1st relocation type */ 1398 } Elf64_Mips_R_Info; 1399 1400 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1401 1402 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1403 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1404 1405 *r_type = mips64_r_info->r_type; 1406 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1407 return; 1408 } 1409 1410 if (is_64bit) { 1411 Elf64_Xword r_info64 = r_info; 1412 1413 r_info = TO_NATIVE(r_info64); 1414 } else { 1415 Elf32_Word r_info32 = r_info; 1416 1417 r_info = TO_NATIVE(r_info32); 1418 } 1419 1420 *r_type = ELF_R_TYPE(r_info); 1421 *r_sym = ELF_R_SYM(r_info); 1422 } 1423 1424 static void section_rela(struct module *mod, struct elf_info *elf, 1425 Elf_Shdr *sechdr) 1426 { 1427 Elf_Rela *rela; 1428 unsigned int fsecndx = sechdr->sh_info; 1429 const char *fromsec = sec_name(elf, fsecndx); 1430 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; 1431 Elf_Rela *stop = (void *)start + sechdr->sh_size; 1432 1433 /* if from section (name) is know good then skip it */ 1434 if (match(fromsec, section_white_list)) 1435 return; 1436 1437 for (rela = start; rela < stop; rela++) { 1438 Elf_Sym *tsym; 1439 Elf_Addr taddr, r_offset; 1440 unsigned int r_type, r_sym; 1441 1442 r_offset = TO_NATIVE(rela->r_offset); 1443 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1444 1445 tsym = elf->symtab_start + r_sym; 1446 taddr = tsym->st_value + TO_NATIVE(rela->r_addend); 1447 1448 switch (elf->hdr->e_machine) { 1449 case EM_RISCV: 1450 if (!strcmp("__ex_table", fromsec) && 1451 r_type == R_RISCV_SUB32) 1452 continue; 1453 break; 1454 case EM_LOONGARCH: 1455 if (!strcmp("__ex_table", fromsec) && 1456 r_type == R_LARCH_SUB32) 1457 continue; 1458 break; 1459 } 1460 1461 check_section_mismatch(mod, elf, tsym, 1462 fsecndx, fromsec, r_offset, taddr); 1463 } 1464 } 1465 1466 static void section_rel(struct module *mod, struct elf_info *elf, 1467 Elf_Shdr *sechdr) 1468 { 1469 Elf_Rel *rel; 1470 unsigned int fsecndx = sechdr->sh_info; 1471 const char *fromsec = sec_name(elf, fsecndx); 1472 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset; 1473 Elf_Rel *stop = (void *)start + sechdr->sh_size; 1474 1475 /* if from section (name) is know good then skip it */ 1476 if (match(fromsec, section_white_list)) 1477 return; 1478 1479 for (rel = start; rel < stop; rel++) { 1480 Elf_Sym *tsym; 1481 Elf_Addr taddr = 0, r_offset; 1482 unsigned int r_type, r_sym; 1483 void *loc; 1484 1485 r_offset = TO_NATIVE(rel->r_offset); 1486 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1487 1488 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1489 tsym = elf->symtab_start + r_sym; 1490 1491 switch (elf->hdr->e_machine) { 1492 case EM_386: 1493 taddr = addend_386_rel(loc, r_type); 1494 break; 1495 case EM_ARM: 1496 taddr = addend_arm_rel(loc, tsym, r_type); 1497 break; 1498 case EM_MIPS: 1499 taddr = addend_mips_rel(loc, r_type); 1500 break; 1501 default: 1502 fatal("Please add code to calculate addend for this architecture\n"); 1503 } 1504 1505 check_section_mismatch(mod, elf, tsym, 1506 fsecndx, fromsec, r_offset, taddr); 1507 } 1508 } 1509 1510 /** 1511 * A module includes a number of sections that are discarded 1512 * either when loaded or when used as built-in. 1513 * For loaded modules all functions marked __init and all data 1514 * marked __initdata will be discarded when the module has been initialized. 1515 * Likewise for modules used built-in the sections marked __exit 1516 * are discarded because __exit marked function are supposed to be called 1517 * only when a module is unloaded which never happens for built-in modules. 1518 * The check_sec_ref() function traverses all relocation records 1519 * to find all references to a section that reference a section that will 1520 * be discarded and warns about it. 1521 **/ 1522 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1523 { 1524 int i; 1525 Elf_Shdr *sechdrs = elf->sechdrs; 1526 1527 /* Walk through all sections */ 1528 for (i = 0; i < elf->num_sections; i++) { 1529 check_section(mod->name, elf, &elf->sechdrs[i]); 1530 /* We want to process only relocation sections and not .init */ 1531 if (sechdrs[i].sh_type == SHT_RELA) 1532 section_rela(mod, elf, &elf->sechdrs[i]); 1533 else if (sechdrs[i].sh_type == SHT_REL) 1534 section_rel(mod, elf, &elf->sechdrs[i]); 1535 } 1536 } 1537 1538 static char *remove_dot(char *s) 1539 { 1540 size_t n = strcspn(s, "."); 1541 1542 if (n && s[n]) { 1543 size_t m = strspn(s + n + 1, "0123456789"); 1544 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1545 s[n] = 0; 1546 } 1547 return s; 1548 } 1549 1550 /* 1551 * The CRCs are recorded in .*.cmd files in the form of: 1552 * #SYMVER <name> <crc> 1553 */ 1554 static void extract_crcs_for_object(const char *object, struct module *mod) 1555 { 1556 char cmd_file[PATH_MAX]; 1557 char *buf, *p; 1558 const char *base; 1559 int dirlen, ret; 1560 1561 base = strrchr(object, '/'); 1562 if (base) { 1563 base++; 1564 dirlen = base - object; 1565 } else { 1566 dirlen = 0; 1567 base = object; 1568 } 1569 1570 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1571 dirlen, object, base); 1572 if (ret >= sizeof(cmd_file)) { 1573 error("%s: too long path was truncated\n", cmd_file); 1574 return; 1575 } 1576 1577 buf = read_text_file(cmd_file); 1578 p = buf; 1579 1580 while ((p = strstr(p, "\n#SYMVER "))) { 1581 char *name; 1582 size_t namelen; 1583 unsigned int crc; 1584 struct symbol *sym; 1585 1586 name = p + strlen("\n#SYMVER "); 1587 1588 p = strchr(name, ' '); 1589 if (!p) 1590 break; 1591 1592 namelen = p - name; 1593 p++; 1594 1595 if (!isdigit(*p)) 1596 continue; /* skip this line */ 1597 1598 crc = strtoul(p, &p, 0); 1599 if (*p != '\n') 1600 continue; /* skip this line */ 1601 1602 name[namelen] = '\0'; 1603 1604 /* 1605 * sym_find_with_module() may return NULL here. 1606 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1607 * Since commit e1327a127703, genksyms calculates CRCs of all 1608 * symbols, including trimmed ones. Ignore orphan CRCs. 1609 */ 1610 sym = sym_find_with_module(name, mod); 1611 if (sym) 1612 sym_set_crc(sym, crc); 1613 } 1614 1615 free(buf); 1616 } 1617 1618 /* 1619 * The symbol versions (CRC) are recorded in the .*.cmd files. 1620 * Parse them to retrieve CRCs for the current module. 1621 */ 1622 static void mod_set_crcs(struct module *mod) 1623 { 1624 char objlist[PATH_MAX]; 1625 char *buf, *p, *obj; 1626 int ret; 1627 1628 if (mod->is_vmlinux) { 1629 strcpy(objlist, ".vmlinux.objs"); 1630 } else { 1631 /* objects for a module are listed in the *.mod file. */ 1632 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1633 if (ret >= sizeof(objlist)) { 1634 error("%s: too long path was truncated\n", objlist); 1635 return; 1636 } 1637 } 1638 1639 buf = read_text_file(objlist); 1640 p = buf; 1641 1642 while ((obj = strsep(&p, "\n")) && obj[0]) 1643 extract_crcs_for_object(obj, mod); 1644 1645 free(buf); 1646 } 1647 1648 static void read_symbols(const char *modname) 1649 { 1650 const char *symname; 1651 char *version; 1652 char *license; 1653 char *namespace; 1654 struct module *mod; 1655 struct elf_info info = { }; 1656 Elf_Sym *sym; 1657 1658 if (!parse_elf(&info, modname)) 1659 return; 1660 1661 if (!strends(modname, ".o")) { 1662 error("%s: filename must be suffixed with .o\n", modname); 1663 return; 1664 } 1665 1666 /* strip trailing .o */ 1667 mod = new_module(modname, strlen(modname) - strlen(".o")); 1668 1669 if (!mod->is_vmlinux) { 1670 license = get_modinfo(&info, "license"); 1671 if (!license) 1672 error("missing MODULE_LICENSE() in %s\n", modname); 1673 while (license) { 1674 if (!license_is_gpl_compatible(license)) { 1675 mod->is_gpl_compatible = false; 1676 break; 1677 } 1678 license = get_next_modinfo(&info, "license", license); 1679 } 1680 1681 namespace = get_modinfo(&info, "import_ns"); 1682 while (namespace) { 1683 add_namespace(&mod->imported_namespaces, namespace); 1684 namespace = get_next_modinfo(&info, "import_ns", 1685 namespace); 1686 } 1687 } 1688 1689 if (extra_warn && !get_modinfo(&info, "description")) 1690 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1691 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1692 symname = remove_dot(info.strtab + sym->st_name); 1693 1694 handle_symbol(mod, &info, sym, symname); 1695 handle_moddevtable(mod, &info, sym, symname); 1696 } 1697 1698 check_sec_ref(mod, &info); 1699 1700 if (!mod->is_vmlinux) { 1701 version = get_modinfo(&info, "version"); 1702 if (version || all_versions) 1703 get_src_version(mod->name, mod->srcversion, 1704 sizeof(mod->srcversion) - 1); 1705 } 1706 1707 parse_elf_finish(&info); 1708 1709 if (modversions) { 1710 /* 1711 * Our trick to get versioning for module struct etc. - it's 1712 * never passed as an argument to an exported function, so 1713 * the automatic versioning doesn't pick it up, but it's really 1714 * important anyhow. 1715 */ 1716 sym_add_unresolved("module_layout", mod, false); 1717 1718 mod_set_crcs(mod); 1719 } 1720 } 1721 1722 static void read_symbols_from_files(const char *filename) 1723 { 1724 FILE *in = stdin; 1725 char fname[PATH_MAX]; 1726 1727 in = fopen(filename, "r"); 1728 if (!in) 1729 fatal("Can't open filenames file %s: %m", filename); 1730 1731 while (fgets(fname, PATH_MAX, in) != NULL) { 1732 if (strends(fname, "\n")) 1733 fname[strlen(fname)-1] = '\0'; 1734 read_symbols(fname); 1735 } 1736 1737 fclose(in); 1738 } 1739 1740 #define SZ 500 1741 1742 /* We first write the generated file into memory using the 1743 * following helper, then compare to the file on disk and 1744 * only update the later if anything changed */ 1745 1746 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1747 const char *fmt, ...) 1748 { 1749 char tmp[SZ]; 1750 int len; 1751 va_list ap; 1752 1753 va_start(ap, fmt); 1754 len = vsnprintf(tmp, SZ, fmt, ap); 1755 buf_write(buf, tmp, len); 1756 va_end(ap); 1757 } 1758 1759 void buf_write(struct buffer *buf, const char *s, int len) 1760 { 1761 if (buf->size - buf->pos < len) { 1762 buf->size += len + SZ; 1763 buf->p = NOFAIL(realloc(buf->p, buf->size)); 1764 } 1765 strncpy(buf->p + buf->pos, s, len); 1766 buf->pos += len; 1767 } 1768 1769 static void check_exports(struct module *mod) 1770 { 1771 struct symbol *s, *exp; 1772 1773 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1774 const char *basename; 1775 exp = find_symbol(s->name); 1776 if (!exp) { 1777 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1778 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, 1779 "\"%s\" [%s.ko] undefined!\n", 1780 s->name, mod->name); 1781 continue; 1782 } 1783 if (exp->module == mod) { 1784 error("\"%s\" [%s.ko] was exported without definition\n", 1785 s->name, mod->name); 1786 continue; 1787 } 1788 1789 exp->used = true; 1790 s->module = exp->module; 1791 s->crc_valid = exp->crc_valid; 1792 s->crc = exp->crc; 1793 1794 basename = strrchr(mod->name, '/'); 1795 if (basename) 1796 basename++; 1797 else 1798 basename = mod->name; 1799 1800 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1801 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, 1802 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1803 basename, exp->name, exp->namespace); 1804 add_namespace(&mod->missing_namespaces, exp->namespace); 1805 } 1806 1807 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1808 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1809 basename, exp->name); 1810 } 1811 } 1812 1813 static void handle_white_list_exports(const char *white_list) 1814 { 1815 char *buf, *p, *name; 1816 1817 buf = read_text_file(white_list); 1818 p = buf; 1819 1820 while ((name = strsep(&p, "\n"))) { 1821 struct symbol *sym = find_symbol(name); 1822 1823 if (sym) 1824 sym->used = true; 1825 } 1826 1827 free(buf); 1828 } 1829 1830 static void check_modname_len(struct module *mod) 1831 { 1832 const char *mod_name; 1833 1834 mod_name = strrchr(mod->name, '/'); 1835 if (mod_name == NULL) 1836 mod_name = mod->name; 1837 else 1838 mod_name++; 1839 if (strlen(mod_name) >= MODULE_NAME_LEN) 1840 error("module name is too long [%s.ko]\n", mod->name); 1841 } 1842 1843 /** 1844 * Header for the generated file 1845 **/ 1846 static void add_header(struct buffer *b, struct module *mod) 1847 { 1848 buf_printf(b, "#include <linux/module.h>\n"); 1849 /* 1850 * Include build-salt.h after module.h in order to 1851 * inherit the definitions. 1852 */ 1853 buf_printf(b, "#define INCLUDE_VERMAGIC\n"); 1854 buf_printf(b, "#include <linux/build-salt.h>\n"); 1855 buf_printf(b, "#include <linux/elfnote-lto.h>\n"); 1856 buf_printf(b, "#include <linux/export-internal.h>\n"); 1857 buf_printf(b, "#include <linux/vermagic.h>\n"); 1858 buf_printf(b, "#include <linux/compiler.h>\n"); 1859 buf_printf(b, "\n"); 1860 buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n"); 1861 buf_printf(b, "#include <asm/orc_header.h>\n"); 1862 buf_printf(b, "ORC_HEADER;\n"); 1863 buf_printf(b, "#endif\n"); 1864 buf_printf(b, "\n"); 1865 buf_printf(b, "BUILD_SALT;\n"); 1866 buf_printf(b, "BUILD_LTO_INFO;\n"); 1867 buf_printf(b, "\n"); 1868 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1869 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1870 buf_printf(b, "\n"); 1871 buf_printf(b, "__visible struct module __this_module\n"); 1872 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1873 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1874 if (mod->has_init) 1875 buf_printf(b, "\t.init = init_module,\n"); 1876 if (mod->has_cleanup) 1877 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1878 "\t.exit = cleanup_module,\n" 1879 "#endif\n"); 1880 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1881 buf_printf(b, "};\n"); 1882 1883 if (!external_module) 1884 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1885 1886 buf_printf(b, 1887 "\n" 1888 "#ifdef CONFIG_RETPOLINE\n" 1889 "MODULE_INFO(retpoline, \"Y\");\n" 1890 "#endif\n"); 1891 1892 if (strstarts(mod->name, "drivers/staging")) 1893 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1894 1895 if (strstarts(mod->name, "tools/testing")) 1896 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1897 } 1898 1899 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1900 { 1901 struct symbol *sym; 1902 1903 /* generate struct for exported symbols */ 1904 buf_printf(buf, "\n"); 1905 list_for_each_entry(sym, &mod->exported_symbols, list) { 1906 if (trim_unused_exports && !sym->used) 1907 continue; 1908 1909 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1910 sym->is_func ? "FUNC" : "DATA", sym->name, 1911 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1912 } 1913 1914 if (!modversions) 1915 return; 1916 1917 /* record CRCs for exported symbols */ 1918 buf_printf(buf, "\n"); 1919 list_for_each_entry(sym, &mod->exported_symbols, list) { 1920 if (trim_unused_exports && !sym->used) 1921 continue; 1922 1923 if (!sym->crc_valid) 1924 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1925 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1926 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1927 sym->name); 1928 1929 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1930 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1931 } 1932 } 1933 1934 /** 1935 * Record CRCs for unresolved symbols 1936 **/ 1937 static void add_versions(struct buffer *b, struct module *mod) 1938 { 1939 struct symbol *s; 1940 1941 if (!modversions) 1942 return; 1943 1944 buf_printf(b, "\n"); 1945 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1946 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1947 1948 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1949 if (!s->module) 1950 continue; 1951 if (!s->crc_valid) { 1952 warn("\"%s\" [%s.ko] has no CRC!\n", 1953 s->name, mod->name); 1954 continue; 1955 } 1956 if (strlen(s->name) >= MODULE_NAME_LEN) { 1957 error("too long symbol \"%s\" [%s.ko]\n", 1958 s->name, mod->name); 1959 break; 1960 } 1961 buf_printf(b, "\t{ %#8x, \"%s\" },\n", 1962 s->crc, s->name); 1963 } 1964 1965 buf_printf(b, "};\n"); 1966 } 1967 1968 static void add_depends(struct buffer *b, struct module *mod) 1969 { 1970 struct symbol *s; 1971 int first = 1; 1972 1973 /* Clear ->seen flag of modules that own symbols needed by this. */ 1974 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1975 if (s->module) 1976 s->module->seen = s->module->is_vmlinux; 1977 } 1978 1979 buf_printf(b, "\n"); 1980 buf_printf(b, "MODULE_INFO(depends, \""); 1981 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1982 const char *p; 1983 if (!s->module) 1984 continue; 1985 1986 if (s->module->seen) 1987 continue; 1988 1989 s->module->seen = true; 1990 p = strrchr(s->module->name, '/'); 1991 if (p) 1992 p++; 1993 else 1994 p = s->module->name; 1995 buf_printf(b, "%s%s", first ? "" : ",", p); 1996 first = 0; 1997 } 1998 buf_printf(b, "\");\n"); 1999 } 2000 2001 static void add_srcversion(struct buffer *b, struct module *mod) 2002 { 2003 if (mod->srcversion[0]) { 2004 buf_printf(b, "\n"); 2005 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 2006 mod->srcversion); 2007 } 2008 } 2009 2010 static void write_buf(struct buffer *b, const char *fname) 2011 { 2012 FILE *file; 2013 2014 if (error_occurred) 2015 return; 2016 2017 file = fopen(fname, "w"); 2018 if (!file) { 2019 perror(fname); 2020 exit(1); 2021 } 2022 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2023 perror(fname); 2024 exit(1); 2025 } 2026 if (fclose(file) != 0) { 2027 perror(fname); 2028 exit(1); 2029 } 2030 } 2031 2032 static void write_if_changed(struct buffer *b, const char *fname) 2033 { 2034 char *tmp; 2035 FILE *file; 2036 struct stat st; 2037 2038 file = fopen(fname, "r"); 2039 if (!file) 2040 goto write; 2041 2042 if (fstat(fileno(file), &st) < 0) 2043 goto close_write; 2044 2045 if (st.st_size != b->pos) 2046 goto close_write; 2047 2048 tmp = NOFAIL(malloc(b->pos)); 2049 if (fread(tmp, 1, b->pos, file) != b->pos) 2050 goto free_write; 2051 2052 if (memcmp(tmp, b->p, b->pos) != 0) 2053 goto free_write; 2054 2055 free(tmp); 2056 fclose(file); 2057 return; 2058 2059 free_write: 2060 free(tmp); 2061 close_write: 2062 fclose(file); 2063 write: 2064 write_buf(b, fname); 2065 } 2066 2067 static void write_vmlinux_export_c_file(struct module *mod) 2068 { 2069 struct buffer buf = { }; 2070 2071 buf_printf(&buf, 2072 "#include <linux/export-internal.h>\n"); 2073 2074 add_exported_symbols(&buf, mod); 2075 write_if_changed(&buf, ".vmlinux.export.c"); 2076 free(buf.p); 2077 } 2078 2079 /* do sanity checks, and generate *.mod.c file */ 2080 static void write_mod_c_file(struct module *mod) 2081 { 2082 struct buffer buf = { }; 2083 char fname[PATH_MAX]; 2084 int ret; 2085 2086 add_header(&buf, mod); 2087 add_exported_symbols(&buf, mod); 2088 add_versions(&buf, mod); 2089 add_depends(&buf, mod); 2090 add_moddevtable(&buf, mod); 2091 add_srcversion(&buf, mod); 2092 2093 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2094 if (ret >= sizeof(fname)) { 2095 error("%s: too long path was truncated\n", fname); 2096 goto free; 2097 } 2098 2099 write_if_changed(&buf, fname); 2100 2101 free: 2102 free(buf.p); 2103 } 2104 2105 /* parse Module.symvers file. line format: 2106 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2107 **/ 2108 static void read_dump(const char *fname) 2109 { 2110 char *buf, *pos, *line; 2111 2112 buf = read_text_file(fname); 2113 if (!buf) 2114 /* No symbol versions, silently ignore */ 2115 return; 2116 2117 pos = buf; 2118 2119 while ((line = get_line(&pos))) { 2120 char *symname, *namespace, *modname, *d, *export; 2121 unsigned int crc; 2122 struct module *mod; 2123 struct symbol *s; 2124 bool gpl_only; 2125 2126 if (!(symname = strchr(line, '\t'))) 2127 goto fail; 2128 *symname++ = '\0'; 2129 if (!(modname = strchr(symname, '\t'))) 2130 goto fail; 2131 *modname++ = '\0'; 2132 if (!(export = strchr(modname, '\t'))) 2133 goto fail; 2134 *export++ = '\0'; 2135 if (!(namespace = strchr(export, '\t'))) 2136 goto fail; 2137 *namespace++ = '\0'; 2138 2139 crc = strtoul(line, &d, 16); 2140 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2141 goto fail; 2142 2143 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2144 gpl_only = true; 2145 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2146 gpl_only = false; 2147 } else { 2148 error("%s: unknown license %s. skip", symname, export); 2149 continue; 2150 } 2151 2152 mod = find_module(modname); 2153 if (!mod) { 2154 mod = new_module(modname, strlen(modname)); 2155 mod->from_dump = true; 2156 } 2157 s = sym_add_exported(symname, mod, gpl_only, namespace); 2158 sym_set_crc(s, crc); 2159 } 2160 free(buf); 2161 return; 2162 fail: 2163 free(buf); 2164 fatal("parse error in symbol dump file\n"); 2165 } 2166 2167 static void write_dump(const char *fname) 2168 { 2169 struct buffer buf = { }; 2170 struct module *mod; 2171 struct symbol *sym; 2172 2173 list_for_each_entry(mod, &modules, list) { 2174 if (mod->from_dump) 2175 continue; 2176 list_for_each_entry(sym, &mod->exported_symbols, list) { 2177 if (trim_unused_exports && !sym->used) 2178 continue; 2179 2180 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2181 sym->crc, sym->name, mod->name, 2182 sym->is_gpl_only ? "_GPL" : "", 2183 sym->namespace); 2184 } 2185 } 2186 write_buf(&buf, fname); 2187 free(buf.p); 2188 } 2189 2190 static void write_namespace_deps_files(const char *fname) 2191 { 2192 struct module *mod; 2193 struct namespace_list *ns; 2194 struct buffer ns_deps_buf = {}; 2195 2196 list_for_each_entry(mod, &modules, list) { 2197 2198 if (mod->from_dump || list_empty(&mod->missing_namespaces)) 2199 continue; 2200 2201 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2202 2203 list_for_each_entry(ns, &mod->missing_namespaces, list) 2204 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2205 2206 buf_printf(&ns_deps_buf, "\n"); 2207 } 2208 2209 write_if_changed(&ns_deps_buf, fname); 2210 free(ns_deps_buf.p); 2211 } 2212 2213 struct dump_list { 2214 struct list_head list; 2215 const char *file; 2216 }; 2217 2218 int main(int argc, char **argv) 2219 { 2220 struct module *mod; 2221 char *missing_namespace_deps = NULL; 2222 char *unused_exports_white_list = NULL; 2223 char *dump_write = NULL, *files_source = NULL; 2224 int opt; 2225 LIST_HEAD(dump_lists); 2226 struct dump_list *dl, *dl2; 2227 2228 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) { 2229 switch (opt) { 2230 case 'e': 2231 external_module = true; 2232 break; 2233 case 'i': 2234 dl = NOFAIL(malloc(sizeof(*dl))); 2235 dl->file = optarg; 2236 list_add_tail(&dl->list, &dump_lists); 2237 break; 2238 case 'M': 2239 module_enabled = true; 2240 break; 2241 case 'm': 2242 modversions = true; 2243 break; 2244 case 'n': 2245 ignore_missing_files = true; 2246 break; 2247 case 'o': 2248 dump_write = optarg; 2249 break; 2250 case 'a': 2251 all_versions = true; 2252 break; 2253 case 'T': 2254 files_source = optarg; 2255 break; 2256 case 't': 2257 trim_unused_exports = true; 2258 break; 2259 case 'u': 2260 unused_exports_white_list = optarg; 2261 break; 2262 case 'W': 2263 extra_warn = true; 2264 break; 2265 case 'w': 2266 warn_unresolved = true; 2267 break; 2268 case 'E': 2269 sec_mismatch_warn_only = false; 2270 break; 2271 case 'N': 2272 allow_missing_ns_imports = true; 2273 break; 2274 case 'd': 2275 missing_namespace_deps = optarg; 2276 break; 2277 default: 2278 exit(1); 2279 } 2280 } 2281 2282 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2283 read_dump(dl->file); 2284 list_del(&dl->list); 2285 free(dl); 2286 } 2287 2288 while (optind < argc) 2289 read_symbols(argv[optind++]); 2290 2291 if (files_source) 2292 read_symbols_from_files(files_source); 2293 2294 list_for_each_entry(mod, &modules, list) { 2295 if (mod->from_dump || mod->is_vmlinux) 2296 continue; 2297 2298 check_modname_len(mod); 2299 check_exports(mod); 2300 } 2301 2302 if (unused_exports_white_list) 2303 handle_white_list_exports(unused_exports_white_list); 2304 2305 list_for_each_entry(mod, &modules, list) { 2306 if (mod->from_dump) 2307 continue; 2308 2309 if (mod->is_vmlinux) 2310 write_vmlinux_export_c_file(mod); 2311 else 2312 write_mod_c_file(mod); 2313 } 2314 2315 if (missing_namespace_deps) 2316 write_namespace_deps_files(missing_namespace_deps); 2317 2318 if (dump_write) 2319 write_dump(dump_write); 2320 if (sec_mismatch_count && !sec_mismatch_warn_only) 2321 error("Section mismatches detected.\n" 2322 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2323 2324 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2325 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2326 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2327 2328 return error_occurred ? 1 : 0; 2329 } 2330