1 /* Postprocess module symbol versions 2 * 3 * Copyright 2003 Kai Germaschewski 4 * Copyright 2002-2004 Rusty Russell, IBM Corporation 5 * Copyright 2006-2008 Sam Ravnborg 6 * Based in part on module-init-tools/depmod.c,file2alias 7 * 8 * This software may be used and distributed according to the terms 9 * of the GNU General Public License, incorporated herein by reference. 10 * 11 * Usage: modpost vmlinux module1.o module2.o ... 12 */ 13 14 #define _GNU_SOURCE 15 #include <elf.h> 16 #include <fnmatch.h> 17 #include <stdio.h> 18 #include <ctype.h> 19 #include <string.h> 20 #include <limits.h> 21 #include <stdbool.h> 22 #include <errno.h> 23 #include "modpost.h" 24 #include "../../include/linux/license.h" 25 26 static bool module_enabled; 27 /* Are we using CONFIG_MODVERSIONS? */ 28 static bool modversions; 29 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 30 static bool all_versions; 31 /* If we are modposting external module set to 1 */ 32 static bool external_module; 33 /* Only warn about unresolved symbols */ 34 static bool warn_unresolved; 35 36 static int sec_mismatch_count; 37 static bool sec_mismatch_warn_only = true; 38 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */ 39 static bool trim_unused_exports; 40 41 /* ignore missing files */ 42 static bool ignore_missing_files; 43 /* If set to 1, only warn (instead of error) about missing ns imports */ 44 static bool allow_missing_ns_imports; 45 46 static bool error_occurred; 47 48 static bool extra_warn; 49 50 /* 51 * Cut off the warnings when there are too many. This typically occurs when 52 * vmlinux is missing. ('make modules' without building vmlinux.) 53 */ 54 #define MAX_UNRESOLVED_REPORTS 10 55 static unsigned int nr_unresolved; 56 57 /* In kernel, this size is defined in linux/module.h; 58 * here we use Elf_Addr instead of long for covering cross-compile 59 */ 60 61 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) 62 63 void modpost_log(enum loglevel loglevel, const char *fmt, ...) 64 { 65 va_list arglist; 66 67 switch (loglevel) { 68 case LOG_WARN: 69 fprintf(stderr, "WARNING: "); 70 break; 71 case LOG_ERROR: 72 fprintf(stderr, "ERROR: "); 73 break; 74 case LOG_FATAL: 75 fprintf(stderr, "FATAL: "); 76 break; 77 default: /* invalid loglevel, ignore */ 78 break; 79 } 80 81 fprintf(stderr, "modpost: "); 82 83 va_start(arglist, fmt); 84 vfprintf(stderr, fmt, arglist); 85 va_end(arglist); 86 87 if (loglevel == LOG_FATAL) 88 exit(1); 89 if (loglevel == LOG_ERROR) 90 error_occurred = true; 91 } 92 93 void __attribute__((alias("modpost_log"))) 94 modpost_log_noret(enum loglevel loglevel, const char *fmt, ...); 95 96 static inline bool strends(const char *str, const char *postfix) 97 { 98 if (strlen(str) < strlen(postfix)) 99 return false; 100 101 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; 102 } 103 104 void *do_nofail(void *ptr, const char *expr) 105 { 106 if (!ptr) 107 fatal("Memory allocation failure: %s.\n", expr); 108 109 return ptr; 110 } 111 112 char *read_text_file(const char *filename) 113 { 114 struct stat st; 115 size_t nbytes; 116 int fd; 117 char *buf; 118 119 fd = open(filename, O_RDONLY); 120 if (fd < 0) { 121 perror(filename); 122 exit(1); 123 } 124 125 if (fstat(fd, &st) < 0) { 126 perror(filename); 127 exit(1); 128 } 129 130 buf = NOFAIL(malloc(st.st_size + 1)); 131 132 nbytes = st.st_size; 133 134 while (nbytes) { 135 ssize_t bytes_read; 136 137 bytes_read = read(fd, buf, nbytes); 138 if (bytes_read < 0) { 139 perror(filename); 140 exit(1); 141 } 142 143 nbytes -= bytes_read; 144 } 145 buf[st.st_size] = '\0'; 146 147 close(fd); 148 149 return buf; 150 } 151 152 char *get_line(char **stringp) 153 { 154 char *orig = *stringp, *next; 155 156 /* do not return the unwanted extra line at EOF */ 157 if (!orig || *orig == '\0') 158 return NULL; 159 160 /* don't use strsep here, it is not available everywhere */ 161 next = strchr(orig, '\n'); 162 if (next) 163 *next++ = '\0'; 164 165 *stringp = next; 166 167 return orig; 168 } 169 170 /* A list of all modules we processed */ 171 LIST_HEAD(modules); 172 173 static struct module *find_module(const char *modname) 174 { 175 struct module *mod; 176 177 list_for_each_entry(mod, &modules, list) { 178 if (strcmp(mod->name, modname) == 0) 179 return mod; 180 } 181 return NULL; 182 } 183 184 static struct module *new_module(const char *name, size_t namelen) 185 { 186 struct module *mod; 187 188 mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1)); 189 memset(mod, 0, sizeof(*mod)); 190 191 INIT_LIST_HEAD(&mod->exported_symbols); 192 INIT_LIST_HEAD(&mod->unresolved_symbols); 193 INIT_LIST_HEAD(&mod->missing_namespaces); 194 INIT_LIST_HEAD(&mod->imported_namespaces); 195 196 memcpy(mod->name, name, namelen); 197 mod->name[namelen] = '\0'; 198 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0); 199 200 /* 201 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE() 202 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue 203 * modpost will exit wiht error anyway. 204 */ 205 mod->is_gpl_compatible = true; 206 207 list_add_tail(&mod->list, &modules); 208 209 return mod; 210 } 211 212 /* A hash of all exported symbols, 213 * struct symbol is also used for lists of unresolved symbols */ 214 215 #define SYMBOL_HASH_SIZE 1024 216 217 struct symbol { 218 struct symbol *next; 219 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */ 220 struct module *module; 221 char *namespace; 222 unsigned int crc; 223 bool crc_valid; 224 bool weak; 225 bool is_func; 226 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ 227 bool used; /* there exists a user of this symbol */ 228 char name[]; 229 }; 230 231 static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 232 233 /* This is based on the hash algorithm from gdbm, via tdb */ 234 static inline unsigned int tdb_hash(const char *name) 235 { 236 unsigned value; /* Used to compute the hash value. */ 237 unsigned i; /* Used to cycle through random values. */ 238 239 /* Set the initial value from the key size. */ 240 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++) 241 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 242 243 return (1103515243 * value + 12345); 244 } 245 246 /** 247 * Allocate a new symbols for use in the hash of exported symbols or 248 * the list of unresolved symbols per module 249 **/ 250 static struct symbol *alloc_symbol(const char *name) 251 { 252 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 253 254 memset(s, 0, sizeof(*s)); 255 strcpy(s->name, name); 256 257 return s; 258 } 259 260 /* For the hash of exported symbols */ 261 static void hash_add_symbol(struct symbol *sym) 262 { 263 unsigned int hash; 264 265 hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE; 266 sym->next = symbolhash[hash]; 267 symbolhash[hash] = sym; 268 } 269 270 static void sym_add_unresolved(const char *name, struct module *mod, bool weak) 271 { 272 struct symbol *sym; 273 274 sym = alloc_symbol(name); 275 sym->weak = weak; 276 277 list_add_tail(&sym->list, &mod->unresolved_symbols); 278 } 279 280 static struct symbol *sym_find_with_module(const char *name, struct module *mod) 281 { 282 struct symbol *s; 283 284 /* For our purposes, .foo matches foo. PPC64 needs this. */ 285 if (name[0] == '.') 286 name++; 287 288 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) { 289 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) 290 return s; 291 } 292 return NULL; 293 } 294 295 static struct symbol *find_symbol(const char *name) 296 { 297 return sym_find_with_module(name, NULL); 298 } 299 300 struct namespace_list { 301 struct list_head list; 302 char namespace[]; 303 }; 304 305 static bool contains_namespace(struct list_head *head, const char *namespace) 306 { 307 struct namespace_list *list; 308 309 /* 310 * The default namespace is null string "", which is always implicitly 311 * contained. 312 */ 313 if (!namespace[0]) 314 return true; 315 316 list_for_each_entry(list, head, list) { 317 if (!strcmp(list->namespace, namespace)) 318 return true; 319 } 320 321 return false; 322 } 323 324 static void add_namespace(struct list_head *head, const char *namespace) 325 { 326 struct namespace_list *ns_entry; 327 328 if (!contains_namespace(head, namespace)) { 329 ns_entry = NOFAIL(malloc(sizeof(*ns_entry) + 330 strlen(namespace) + 1)); 331 strcpy(ns_entry->namespace, namespace); 332 list_add_tail(&ns_entry->list, head); 333 } 334 } 335 336 static void *sym_get_data_by_offset(const struct elf_info *info, 337 unsigned int secindex, unsigned long offset) 338 { 339 Elf_Shdr *sechdr = &info->sechdrs[secindex]; 340 341 return (void *)info->hdr + sechdr->sh_offset + offset; 342 } 343 344 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) 345 { 346 return sym_get_data_by_offset(info, get_secindex(info, sym), 347 sym->st_value); 348 } 349 350 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) 351 { 352 return sym_get_data_by_offset(info, info->secindex_strings, 353 sechdr->sh_name); 354 } 355 356 static const char *sec_name(const struct elf_info *info, unsigned int secindex) 357 { 358 /* 359 * If sym->st_shndx is a special section index, there is no 360 * corresponding section header. 361 * Return "" if the index is out of range of info->sechdrs[] array. 362 */ 363 if (secindex >= info->num_sections) 364 return ""; 365 366 return sech_name(info, &info->sechdrs[secindex]); 367 } 368 369 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) 370 371 static struct symbol *sym_add_exported(const char *name, struct module *mod, 372 bool gpl_only, const char *namespace) 373 { 374 struct symbol *s = find_symbol(name); 375 376 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { 377 error("%s: '%s' exported twice. Previous export was in %s%s\n", 378 mod->name, name, s->module->name, 379 s->module->is_vmlinux ? "" : ".ko"); 380 } 381 382 s = alloc_symbol(name); 383 s->module = mod; 384 s->is_gpl_only = gpl_only; 385 s->namespace = NOFAIL(strdup(namespace)); 386 list_add_tail(&s->list, &mod->exported_symbols); 387 hash_add_symbol(s); 388 389 return s; 390 } 391 392 static void sym_set_crc(struct symbol *sym, unsigned int crc) 393 { 394 sym->crc = crc; 395 sym->crc_valid = true; 396 } 397 398 static void *grab_file(const char *filename, size_t *size) 399 { 400 struct stat st; 401 void *map = MAP_FAILED; 402 int fd; 403 404 fd = open(filename, O_RDONLY); 405 if (fd < 0) 406 return NULL; 407 if (fstat(fd, &st)) 408 goto failed; 409 410 *size = st.st_size; 411 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 412 413 failed: 414 close(fd); 415 if (map == MAP_FAILED) 416 return NULL; 417 return map; 418 } 419 420 static void release_file(void *file, size_t size) 421 { 422 munmap(file, size); 423 } 424 425 static int parse_elf(struct elf_info *info, const char *filename) 426 { 427 unsigned int i; 428 Elf_Ehdr *hdr; 429 Elf_Shdr *sechdrs; 430 Elf_Sym *sym; 431 const char *secstrings; 432 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 433 434 hdr = grab_file(filename, &info->size); 435 if (!hdr) { 436 if (ignore_missing_files) { 437 fprintf(stderr, "%s: %s (ignored)\n", filename, 438 strerror(errno)); 439 return 0; 440 } 441 perror(filename); 442 exit(1); 443 } 444 info->hdr = hdr; 445 if (info->size < sizeof(*hdr)) { 446 /* file too small, assume this is an empty .o file */ 447 return 0; 448 } 449 /* Is this a valid ELF file? */ 450 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 451 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 452 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 453 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 454 /* Not an ELF file - silently ignore it */ 455 return 0; 456 } 457 /* Fix endianness in ELF header */ 458 hdr->e_type = TO_NATIVE(hdr->e_type); 459 hdr->e_machine = TO_NATIVE(hdr->e_machine); 460 hdr->e_version = TO_NATIVE(hdr->e_version); 461 hdr->e_entry = TO_NATIVE(hdr->e_entry); 462 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 463 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 464 hdr->e_flags = TO_NATIVE(hdr->e_flags); 465 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 466 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 467 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 468 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 469 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 470 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 471 sechdrs = (void *)hdr + hdr->e_shoff; 472 info->sechdrs = sechdrs; 473 474 /* modpost only works for relocatable objects */ 475 if (hdr->e_type != ET_REL) 476 fatal("%s: not relocatable object.", filename); 477 478 /* Check if file offset is correct */ 479 if (hdr->e_shoff > info->size) 480 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", 481 (unsigned long)hdr->e_shoff, filename, info->size); 482 483 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)); 523 524 secname = secstrings + sechdrs[i].sh_name; 525 if (strcmp(secname, ".modinfo") == 0) { 526 if (nobits) 527 fatal("%s has NOBITS .modinfo\n", filename); 528 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 529 info->modinfo_len = sechdrs[i].sh_size; 530 } else if (!strcmp(secname, ".export_symbol")) { 531 info->export_symbol_secndx = i; 532 } 533 534 if (sechdrs[i].sh_type == SHT_SYMTAB) { 535 unsigned int sh_link_idx; 536 symtab_idx = i; 537 info->symtab_start = (void *)hdr + 538 sechdrs[i].sh_offset; 539 info->symtab_stop = (void *)hdr + 540 sechdrs[i].sh_offset + sechdrs[i].sh_size; 541 sh_link_idx = sechdrs[i].sh_link; 542 info->strtab = (void *)hdr + 543 sechdrs[sh_link_idx].sh_offset; 544 } 545 546 /* 32bit section no. table? ("more than 64k sections") */ 547 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 548 symtab_shndx_idx = i; 549 info->symtab_shndx_start = (void *)hdr + 550 sechdrs[i].sh_offset; 551 info->symtab_shndx_stop = (void *)hdr + 552 sechdrs[i].sh_offset + sechdrs[i].sh_size; 553 } 554 } 555 if (!info->symtab_start) 556 fatal("%s has no symtab?\n", filename); 557 558 /* Fix endianness in symbols */ 559 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 560 sym->st_shndx = TO_NATIVE(sym->st_shndx); 561 sym->st_name = TO_NATIVE(sym->st_name); 562 sym->st_value = TO_NATIVE(sym->st_value); 563 sym->st_size = TO_NATIVE(sym->st_size); 564 } 565 566 if (symtab_shndx_idx != ~0U) { 567 Elf32_Word *p; 568 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 569 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 570 filename, sechdrs[symtab_shndx_idx].sh_link, 571 symtab_idx); 572 /* Fix endianness */ 573 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 574 p++) 575 *p = TO_NATIVE(*p); 576 } 577 578 symsearch_init(info); 579 580 return 1; 581 } 582 583 static void parse_elf_finish(struct elf_info *info) 584 { 585 symsearch_finish(info); 586 release_file(info->hdr, info->size); 587 } 588 589 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 590 { 591 /* ignore __this_module, it will be resolved shortly */ 592 if (strcmp(symname, "__this_module") == 0) 593 return 1; 594 /* ignore global offset table */ 595 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 596 return 1; 597 if (info->hdr->e_machine == EM_PPC) 598 /* Special register function linked on all modules during final link of .ko */ 599 if (strstarts(symname, "_restgpr_") || 600 strstarts(symname, "_savegpr_") || 601 strstarts(symname, "_rest32gpr_") || 602 strstarts(symname, "_save32gpr_") || 603 strstarts(symname, "_restvr_") || 604 strstarts(symname, "_savevr_")) 605 return 1; 606 if (info->hdr->e_machine == EM_PPC64) 607 /* Special register function linked on all modules during final link of .ko */ 608 if (strstarts(symname, "_restgpr0_") || 609 strstarts(symname, "_savegpr0_") || 610 strstarts(symname, "_restvr_") || 611 strstarts(symname, "_savevr_") || 612 strcmp(symname, ".TOC.") == 0) 613 return 1; 614 615 if (info->hdr->e_machine == EM_S390) 616 /* Expoline thunks are linked on all kernel modules during final link of .ko */ 617 if (strstarts(symname, "__s390_indirect_jump_r")) 618 return 1; 619 /* Do not ignore this symbol */ 620 return 0; 621 } 622 623 static void handle_symbol(struct module *mod, struct elf_info *info, 624 const Elf_Sym *sym, const char *symname) 625 { 626 switch (sym->st_shndx) { 627 case SHN_COMMON: 628 if (strstarts(symname, "__gnu_lto_")) { 629 /* Should warn here, but modpost runs before the linker */ 630 } else 631 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 632 break; 633 case SHN_UNDEF: 634 /* undefined symbol */ 635 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 636 ELF_ST_BIND(sym->st_info) != STB_WEAK) 637 break; 638 if (ignore_undef_symbol(info, symname)) 639 break; 640 if (info->hdr->e_machine == EM_SPARC || 641 info->hdr->e_machine == EM_SPARCV9) { 642 /* Ignore register directives. */ 643 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 644 break; 645 if (symname[0] == '.') { 646 char *munged = NOFAIL(strdup(symname)); 647 munged[0] = '_'; 648 munged[1] = toupper(munged[1]); 649 symname = munged; 650 } 651 } 652 653 sym_add_unresolved(symname, mod, 654 ELF_ST_BIND(sym->st_info) == STB_WEAK); 655 break; 656 default: 657 if (strcmp(symname, "init_module") == 0) 658 mod->has_init = true; 659 if (strcmp(symname, "cleanup_module") == 0) 660 mod->has_cleanup = true; 661 break; 662 } 663 } 664 665 /** 666 * Parse tag=value strings from .modinfo section 667 **/ 668 static char *next_string(char *string, unsigned long *secsize) 669 { 670 /* Skip non-zero chars */ 671 while (string[0]) { 672 string++; 673 if ((*secsize)-- <= 1) 674 return NULL; 675 } 676 677 /* Skip any zero padding. */ 678 while (!string[0]) { 679 string++; 680 if ((*secsize)-- <= 1) 681 return NULL; 682 } 683 return string; 684 } 685 686 static char *get_next_modinfo(struct elf_info *info, const char *tag, 687 char *prev) 688 { 689 char *p; 690 unsigned int taglen = strlen(tag); 691 char *modinfo = info->modinfo; 692 unsigned long size = info->modinfo_len; 693 694 if (prev) { 695 size -= prev - modinfo; 696 modinfo = next_string(prev, &size); 697 } 698 699 for (p = modinfo; p; p = next_string(p, &size)) { 700 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 701 return p + taglen + 1; 702 } 703 return NULL; 704 } 705 706 static char *get_modinfo(struct elf_info *info, const char *tag) 707 708 { 709 return get_next_modinfo(info, tag, NULL); 710 } 711 712 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 713 { 714 if (sym) 715 return elf->strtab + sym->st_name; 716 else 717 return "(unknown)"; 718 } 719 720 /* 721 * Check whether the 'string' argument matches one of the 'patterns', 722 * an array of shell wildcard patterns (glob). 723 * 724 * Return true is there is a match. 725 */ 726 static bool match(const char *string, const char *const patterns[]) 727 { 728 const char *pattern; 729 730 while ((pattern = *patterns++)) { 731 if (!fnmatch(pattern, string, 0)) 732 return true; 733 } 734 735 return false; 736 } 737 738 /* useful to pass patterns to match() directly */ 739 #define PATTERNS(...) \ 740 ({ \ 741 static const char *const patterns[] = {__VA_ARGS__, NULL}; \ 742 patterns; \ 743 }) 744 745 /* sections that we do not want to do full section mismatch check on */ 746 static const char *const section_white_list[] = 747 { 748 ".comment*", 749 ".debug*", 750 ".zdebug*", /* Compressed debug sections. */ 751 ".GCC.command.line", /* record-gcc-switches */ 752 ".mdebug*", /* alpha, score, mips etc. */ 753 ".pdr", /* alpha, score, mips etc. */ 754 ".stab*", 755 ".note*", 756 ".got*", 757 ".toc*", 758 ".xt.prop", /* xtensa */ 759 ".xt.lit", /* xtensa */ 760 ".arcextmap*", /* arc */ 761 ".gnu.linkonce.arcext*", /* arc : modules */ 762 ".cmem*", /* EZchip */ 763 ".fmt_slot*", /* EZchip */ 764 ".gnu.lto*", 765 ".discard.*", 766 ".llvm.call-graph-profile", /* call graph */ 767 NULL 768 }; 769 770 /* 771 * This is used to find sections missing the SHF_ALLOC flag. 772 * The cause of this is often a section specified in assembler 773 * without "ax" / "aw". 774 */ 775 static void check_section(const char *modname, struct elf_info *elf, 776 Elf_Shdr *sechdr) 777 { 778 const char *sec = sech_name(elf, sechdr); 779 780 if (sechdr->sh_type == SHT_PROGBITS && 781 !(sechdr->sh_flags & SHF_ALLOC) && 782 !match(sec, section_white_list)) { 783 warn("%s (%s): unexpected non-allocatable section.\n" 784 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 785 "Note that for example <linux/init.h> contains\n" 786 "section definitions for use in .S files.\n\n", 787 modname, sec); 788 } 789 } 790 791 792 793 #define ALL_INIT_DATA_SECTIONS \ 794 ".init.setup", ".init.rodata", ".meminit.rodata", \ 795 ".init.data", ".meminit.data" 796 797 #define ALL_PCI_INIT_SECTIONS \ 798 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 799 ".pci_fixup_enable", ".pci_fixup_resume", \ 800 ".pci_fixup_resume_early", ".pci_fixup_suspend" 801 802 #define ALL_XXXINIT_SECTIONS ".meminit.*" 803 804 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 805 #define ALL_EXIT_SECTIONS ".exit.*" 806 807 #define DATA_SECTIONS ".data", ".data.rel" 808 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ 809 ".kprobes.text", ".cpuidle.text", ".noinstr.text" 810 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ 811 ".fixup", ".entry.text", ".exception.text", \ 812 ".coldtext", ".softirqentry.text" 813 814 #define INIT_SECTIONS ".init.*" 815 816 #define ALL_TEXT_SECTIONS ".init.text", ".meminit.text", ".exit.text", \ 817 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 818 819 enum mismatch { 820 TEXTDATA_TO_ANY_INIT_EXIT, 821 XXXINIT_TO_SOME_INIT, 822 ANY_INIT_TO_ANY_EXIT, 823 ANY_EXIT_TO_ANY_INIT, 824 EXTABLE_TO_NON_TEXT, 825 }; 826 827 /** 828 * Describe how to match sections on different criteria: 829 * 830 * @fromsec: Array of sections to be matched. 831 * 832 * @bad_tosec: Relocations applied to a section in @fromsec to a section in 833 * this array is forbidden (black-list). Can be empty. 834 * 835 * @good_tosec: Relocations applied to a section in @fromsec must be 836 * targeting sections in this array (white-list). Can be empty. 837 * 838 * @mismatch: Type of mismatch. 839 */ 840 struct sectioncheck { 841 const char *fromsec[20]; 842 const char *bad_tosec[20]; 843 const char *good_tosec[20]; 844 enum mismatch mismatch; 845 }; 846 847 static const struct sectioncheck sectioncheck[] = { 848 /* Do not reference init/exit code/data from 849 * normal code and data 850 */ 851 { 852 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 853 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }, 854 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT, 855 }, 856 /* Do not reference init code/data from meminit code/data */ 857 { 858 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 859 .bad_tosec = { INIT_SECTIONS, NULL }, 860 .mismatch = XXXINIT_TO_SOME_INIT, 861 }, 862 /* Do not use exit code/data from init code */ 863 { 864 .fromsec = { ALL_INIT_SECTIONS, NULL }, 865 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 866 .mismatch = ANY_INIT_TO_ANY_EXIT, 867 }, 868 /* Do not use init code/data from exit code */ 869 { 870 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 871 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 872 .mismatch = ANY_EXIT_TO_ANY_INIT, 873 }, 874 { 875 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 876 .bad_tosec = { INIT_SECTIONS, NULL }, 877 .mismatch = ANY_INIT_TO_ANY_EXIT, 878 }, 879 { 880 .fromsec = { "__ex_table", NULL }, 881 /* If you're adding any new black-listed sections in here, consider 882 * adding a special 'printer' for them in scripts/check_extable. 883 */ 884 .bad_tosec = { ".altinstr_replacement", NULL }, 885 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 886 .mismatch = EXTABLE_TO_NON_TEXT, 887 } 888 }; 889 890 static const struct sectioncheck *section_mismatch( 891 const char *fromsec, const char *tosec) 892 { 893 int i; 894 895 /* 896 * The target section could be the SHT_NUL section when we're 897 * handling relocations to un-resolved symbols, trying to match it 898 * doesn't make much sense and causes build failures on parisc 899 * architectures. 900 */ 901 if (*tosec == '\0') 902 return NULL; 903 904 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 905 const struct sectioncheck *check = §ioncheck[i]; 906 907 if (match(fromsec, check->fromsec)) { 908 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 909 return check; 910 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 911 return check; 912 } 913 } 914 return NULL; 915 } 916 917 /** 918 * Whitelist to allow certain references to pass with no warning. 919 * 920 * Pattern 1: 921 * If a module parameter is declared __initdata and permissions=0 922 * then this is legal despite the warning generated. 923 * We cannot see value of permissions here, so just ignore 924 * this pattern. 925 * The pattern is identified by: 926 * tosec = .init.data 927 * fromsec = .data* 928 * atsym =__param* 929 * 930 * Pattern 1a: 931 * module_param_call() ops can refer to __init set function if permissions=0 932 * The pattern is identified by: 933 * tosec = .init.text 934 * fromsec = .data* 935 * atsym = __param_ops_* 936 * 937 * Pattern 3: 938 * Whitelist all references from .head.text to any init section 939 * 940 * Pattern 4: 941 * Some symbols belong to init section but still it is ok to reference 942 * these from non-init sections as these symbols don't have any memory 943 * allocated for them and symbol address and value are same. So even 944 * if init section is freed, its ok to reference those symbols. 945 * For ex. symbols marking the init section boundaries. 946 * This pattern is identified by 947 * refsymname = __init_begin, _sinittext, _einittext 948 * 949 * Pattern 5: 950 * GCC may optimize static inlines when fed constant arg(s) resulting 951 * in functions like cpumask_empty() -- generating an associated symbol 952 * cpumask_empty.constprop.3 that appears in the audit. If the const that 953 * is passed in comes from __init, like say nmi_ipi_mask, we get a 954 * meaningless section warning. May need to add isra symbols too... 955 * This pattern is identified by 956 * tosec = init section 957 * fromsec = text section 958 * refsymname = *.constprop.* 959 * 960 **/ 961 static int secref_whitelist(const char *fromsec, const char *fromsym, 962 const char *tosec, const char *tosym) 963 { 964 /* Check for pattern 1 */ 965 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 966 match(fromsec, PATTERNS(DATA_SECTIONS)) && 967 strstarts(fromsym, "__param")) 968 return 0; 969 970 /* Check for pattern 1a */ 971 if (strcmp(tosec, ".init.text") == 0 && 972 match(fromsec, PATTERNS(DATA_SECTIONS)) && 973 strstarts(fromsym, "__param_ops_")) 974 return 0; 975 976 /* symbols in data sections that may refer to any init/exit sections */ 977 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 978 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 979 match(fromsym, PATTERNS("*_ops", "*_probe", "*_console"))) 980 return 0; 981 982 /* 983 * symbols in data sections must not refer to .exit.*, but there are 984 * quite a few offenders, so hide these unless for W=1 builds until 985 * these are fixed. 986 */ 987 if (!extra_warn && 988 match(fromsec, PATTERNS(DATA_SECTIONS)) && 989 match(tosec, PATTERNS(ALL_EXIT_SECTIONS)) && 990 match(fromsym, PATTERNS("*driver"))) 991 return 0; 992 993 /* Check for pattern 3 */ 994 if (strstarts(fromsec, ".head.text") && 995 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 996 return 0; 997 998 /* Check for pattern 4 */ 999 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 1000 return 0; 1001 1002 /* Check for pattern 5 */ 1003 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 1004 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 1005 match(fromsym, PATTERNS("*.constprop.*"))) 1006 return 0; 1007 1008 return 1; 1009 } 1010 1011 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 1012 unsigned int secndx) 1013 { 1014 return symsearch_find_nearest(elf, addr, secndx, false, ~0); 1015 } 1016 1017 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 1018 { 1019 /* If the supplied symbol has a valid name, return it */ 1020 if (is_valid_name(elf, sym)) 1021 return sym; 1022 1023 /* 1024 * Strive to find a better symbol name, but the resulting name may not 1025 * match the symbol referenced in the original code. 1026 */ 1027 return symsearch_find_nearest(elf, addr, get_secindex(elf, sym), 1028 true, 20); 1029 } 1030 1031 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1032 { 1033 if (secndx >= elf->num_sections) 1034 return false; 1035 1036 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1037 } 1038 1039 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1040 const struct sectioncheck* const mismatch, 1041 Elf_Sym *tsym, 1042 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1043 const char *tosec, Elf_Addr taddr) 1044 { 1045 Elf_Sym *from; 1046 const char *tosym; 1047 const char *fromsym; 1048 1049 from = find_fromsym(elf, faddr, fsecndx); 1050 fromsym = sym_name(elf, from); 1051 1052 tsym = find_tosym(elf, taddr, tsym); 1053 tosym = sym_name(elf, tsym); 1054 1055 /* check whitelist - we may ignore it */ 1056 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1057 return; 1058 1059 sec_mismatch_count++; 1060 1061 warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n", 1062 modname, fromsym, (unsigned int)(faddr - from->st_value), fromsec, tosym, tosec); 1063 1064 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1065 if (match(tosec, mismatch->bad_tosec)) 1066 fatal("The relocation at %s+0x%lx references\n" 1067 "section \"%s\" which is black-listed.\n" 1068 "Something is seriously wrong and should be fixed.\n" 1069 "You might get more information about where this is\n" 1070 "coming from by using scripts/check_extable.sh %s\n", 1071 fromsec, (long)faddr, tosec, modname); 1072 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1073 warn("The relocation at %s+0x%lx references\n" 1074 "section \"%s\" which is not in the list of\n" 1075 "authorized sections. If you're adding a new section\n" 1076 "and/or if this reference is valid, add \"%s\" to the\n" 1077 "list of authorized sections to jump to on fault.\n" 1078 "This can be achieved by adding \"%s\" to\n" 1079 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1080 fromsec, (long)faddr, tosec, tosec, tosec); 1081 else 1082 error("%s+0x%lx references non-executable section '%s'\n", 1083 fromsec, (long)faddr, tosec); 1084 } 1085 } 1086 1087 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1088 Elf_Addr faddr, const char *secname, 1089 Elf_Sym *sym) 1090 { 1091 static const char *prefix = "__export_symbol_"; 1092 const char *label_name, *name, *data; 1093 Elf_Sym *label; 1094 struct symbol *s; 1095 bool is_gpl; 1096 1097 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1098 label_name = sym_name(elf, label); 1099 1100 if (!strstarts(label_name, prefix)) { 1101 error("%s: .export_symbol section contains strange symbol '%s'\n", 1102 mod->name, label_name); 1103 return; 1104 } 1105 1106 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1107 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1108 error("%s: local symbol '%s' was exported\n", mod->name, 1109 label_name + strlen(prefix)); 1110 return; 1111 } 1112 1113 name = sym_name(elf, sym); 1114 if (strcmp(label_name + strlen(prefix), name)) { 1115 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1116 mod->name, name); 1117 return; 1118 } 1119 1120 data = sym_get_data(elf, label); /* license */ 1121 if (!strcmp(data, "GPL")) { 1122 is_gpl = true; 1123 } else if (!strcmp(data, "")) { 1124 is_gpl = false; 1125 } else { 1126 error("%s: unknown license '%s' was specified for '%s'\n", 1127 mod->name, data, name); 1128 return; 1129 } 1130 1131 data += strlen(data) + 1; /* namespace */ 1132 s = sym_add_exported(name, mod, is_gpl, data); 1133 1134 /* 1135 * We need to be aware whether we are exporting a function or 1136 * a data on some architectures. 1137 */ 1138 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1139 1140 /* 1141 * For parisc64, symbols prefixed $$ from the library have the symbol type 1142 * STT_LOPROC. They should be handled as functions too. 1143 */ 1144 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1145 elf->hdr->e_machine == EM_PARISC && 1146 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1147 s->is_func = true; 1148 1149 if (match(secname, PATTERNS(ALL_INIT_SECTIONS))) 1150 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1151 mod->name, name); 1152 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS))) 1153 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1154 mod->name, name); 1155 } 1156 1157 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1158 Elf_Sym *sym, 1159 unsigned int fsecndx, const char *fromsec, 1160 Elf_Addr faddr, Elf_Addr taddr) 1161 { 1162 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1163 const struct sectioncheck *mismatch; 1164 1165 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1166 check_export_symbol(mod, elf, faddr, tosec, sym); 1167 return; 1168 } 1169 1170 mismatch = section_mismatch(fromsec, tosec); 1171 if (!mismatch) 1172 return; 1173 1174 default_mismatch_handler(mod->name, elf, mismatch, sym, 1175 fsecndx, fromsec, faddr, 1176 tosec, taddr); 1177 } 1178 1179 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1180 { 1181 switch (r_type) { 1182 case R_386_32: 1183 return TO_NATIVE(*location); 1184 case R_386_PC32: 1185 return TO_NATIVE(*location) + 4; 1186 } 1187 1188 return (Elf_Addr)(-1); 1189 } 1190 1191 #ifndef R_ARM_CALL 1192 #define R_ARM_CALL 28 1193 #endif 1194 #ifndef R_ARM_JUMP24 1195 #define R_ARM_JUMP24 29 1196 #endif 1197 1198 #ifndef R_ARM_THM_CALL 1199 #define R_ARM_THM_CALL 10 1200 #endif 1201 #ifndef R_ARM_THM_JUMP24 1202 #define R_ARM_THM_JUMP24 30 1203 #endif 1204 1205 #ifndef R_ARM_MOVW_ABS_NC 1206 #define R_ARM_MOVW_ABS_NC 43 1207 #endif 1208 1209 #ifndef R_ARM_MOVT_ABS 1210 #define R_ARM_MOVT_ABS 44 1211 #endif 1212 1213 #ifndef R_ARM_THM_MOVW_ABS_NC 1214 #define R_ARM_THM_MOVW_ABS_NC 47 1215 #endif 1216 1217 #ifndef R_ARM_THM_MOVT_ABS 1218 #define R_ARM_THM_MOVT_ABS 48 1219 #endif 1220 1221 #ifndef R_ARM_THM_JUMP19 1222 #define R_ARM_THM_JUMP19 51 1223 #endif 1224 1225 static int32_t sign_extend32(int32_t value, int index) 1226 { 1227 uint8_t shift = 31 - index; 1228 1229 return (int32_t)(value << shift) >> shift; 1230 } 1231 1232 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1233 { 1234 uint32_t inst, upper, lower, sign, j1, j2; 1235 int32_t offset; 1236 1237 switch (r_type) { 1238 case R_ARM_ABS32: 1239 case R_ARM_REL32: 1240 inst = TO_NATIVE(*(uint32_t *)loc); 1241 return inst + sym->st_value; 1242 case R_ARM_MOVW_ABS_NC: 1243 case R_ARM_MOVT_ABS: 1244 inst = TO_NATIVE(*(uint32_t *)loc); 1245 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1246 15); 1247 return offset + sym->st_value; 1248 case R_ARM_PC24: 1249 case R_ARM_CALL: 1250 case R_ARM_JUMP24: 1251 inst = TO_NATIVE(*(uint32_t *)loc); 1252 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1253 return offset + sym->st_value + 8; 1254 case R_ARM_THM_MOVW_ABS_NC: 1255 case R_ARM_THM_MOVT_ABS: 1256 upper = TO_NATIVE(*(uint16_t *)loc); 1257 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1258 offset = sign_extend32(((upper & 0x000f) << 12) | 1259 ((upper & 0x0400) << 1) | 1260 ((lower & 0x7000) >> 4) | 1261 (lower & 0x00ff), 1262 15); 1263 return offset + sym->st_value; 1264 case R_ARM_THM_JUMP19: 1265 /* 1266 * Encoding T3: 1267 * S = upper[10] 1268 * imm6 = upper[5:0] 1269 * J1 = lower[13] 1270 * J2 = lower[11] 1271 * imm11 = lower[10:0] 1272 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1273 */ 1274 upper = TO_NATIVE(*(uint16_t *)loc); 1275 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1276 1277 sign = (upper >> 10) & 1; 1278 j1 = (lower >> 13) & 1; 1279 j2 = (lower >> 11) & 1; 1280 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1281 ((upper & 0x03f) << 12) | 1282 ((lower & 0x07ff) << 1), 1283 20); 1284 return offset + sym->st_value + 4; 1285 case R_ARM_THM_CALL: 1286 case R_ARM_THM_JUMP24: 1287 /* 1288 * Encoding T4: 1289 * S = upper[10] 1290 * imm10 = upper[9:0] 1291 * J1 = lower[13] 1292 * J2 = lower[11] 1293 * imm11 = lower[10:0] 1294 * I1 = NOT(J1 XOR S) 1295 * I2 = NOT(J2 XOR S) 1296 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1297 */ 1298 upper = TO_NATIVE(*(uint16_t *)loc); 1299 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1300 1301 sign = (upper >> 10) & 1; 1302 j1 = (lower >> 13) & 1; 1303 j2 = (lower >> 11) & 1; 1304 offset = sign_extend32((sign << 24) | 1305 ((~(j1 ^ sign) & 1) << 23) | 1306 ((~(j2 ^ sign) & 1) << 22) | 1307 ((upper & 0x03ff) << 12) | 1308 ((lower & 0x07ff) << 1), 1309 24); 1310 return offset + sym->st_value + 4; 1311 } 1312 1313 return (Elf_Addr)(-1); 1314 } 1315 1316 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1317 { 1318 uint32_t inst; 1319 1320 inst = TO_NATIVE(*location); 1321 switch (r_type) { 1322 case R_MIPS_LO16: 1323 return inst & 0xffff; 1324 case R_MIPS_26: 1325 return (inst & 0x03ffffff) << 2; 1326 case R_MIPS_32: 1327 return inst; 1328 } 1329 return (Elf_Addr)(-1); 1330 } 1331 1332 #ifndef EM_RISCV 1333 #define EM_RISCV 243 1334 #endif 1335 1336 #ifndef R_RISCV_SUB32 1337 #define R_RISCV_SUB32 39 1338 #endif 1339 1340 #ifndef EM_LOONGARCH 1341 #define EM_LOONGARCH 258 1342 #endif 1343 1344 #ifndef R_LARCH_SUB32 1345 #define R_LARCH_SUB32 55 1346 #endif 1347 1348 #ifndef R_LARCH_RELAX 1349 #define R_LARCH_RELAX 100 1350 #endif 1351 1352 #ifndef R_LARCH_ALIGN 1353 #define R_LARCH_ALIGN 102 1354 #endif 1355 1356 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1357 unsigned int *r_type, unsigned int *r_sym) 1358 { 1359 typedef struct { 1360 Elf64_Word r_sym; /* Symbol index */ 1361 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1362 unsigned char r_type3; /* 3rd relocation type */ 1363 unsigned char r_type2; /* 2nd relocation type */ 1364 unsigned char r_type; /* 1st relocation type */ 1365 } Elf64_Mips_R_Info; 1366 1367 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1368 1369 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1370 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1371 1372 *r_type = mips64_r_info->r_type; 1373 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1374 return; 1375 } 1376 1377 if (is_64bit) 1378 r_info = TO_NATIVE((Elf64_Xword)r_info); 1379 else 1380 r_info = TO_NATIVE((Elf32_Word)r_info); 1381 1382 *r_type = ELF_R_TYPE(r_info); 1383 *r_sym = ELF_R_SYM(r_info); 1384 } 1385 1386 static void section_rela(struct module *mod, struct elf_info *elf, 1387 unsigned int fsecndx, const char *fromsec, 1388 const Elf_Rela *start, const Elf_Rela *stop) 1389 { 1390 const Elf_Rela *rela; 1391 1392 for (rela = start; rela < stop; rela++) { 1393 Elf_Sym *tsym; 1394 Elf_Addr taddr, r_offset; 1395 unsigned int r_type, r_sym; 1396 1397 r_offset = TO_NATIVE(rela->r_offset); 1398 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1399 1400 tsym = elf->symtab_start + r_sym; 1401 taddr = tsym->st_value + TO_NATIVE(rela->r_addend); 1402 1403 switch (elf->hdr->e_machine) { 1404 case EM_RISCV: 1405 if (!strcmp("__ex_table", fromsec) && 1406 r_type == R_RISCV_SUB32) 1407 continue; 1408 break; 1409 case EM_LOONGARCH: 1410 switch (r_type) { 1411 case R_LARCH_SUB32: 1412 if (!strcmp("__ex_table", fromsec)) 1413 continue; 1414 break; 1415 case R_LARCH_RELAX: 1416 case R_LARCH_ALIGN: 1417 /* These relocs do not refer to symbols */ 1418 continue; 1419 } 1420 break; 1421 } 1422 1423 check_section_mismatch(mod, elf, tsym, 1424 fsecndx, fromsec, r_offset, taddr); 1425 } 1426 } 1427 1428 static void section_rel(struct module *mod, struct elf_info *elf, 1429 unsigned int fsecndx, const char *fromsec, 1430 const Elf_Rel *start, const Elf_Rel *stop) 1431 { 1432 const Elf_Rel *rel; 1433 1434 for (rel = start; rel < stop; rel++) { 1435 Elf_Sym *tsym; 1436 Elf_Addr taddr, r_offset; 1437 unsigned int r_type, r_sym; 1438 void *loc; 1439 1440 r_offset = TO_NATIVE(rel->r_offset); 1441 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1442 1443 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1444 tsym = elf->symtab_start + r_sym; 1445 1446 switch (elf->hdr->e_machine) { 1447 case EM_386: 1448 taddr = addend_386_rel(loc, r_type); 1449 break; 1450 case EM_ARM: 1451 taddr = addend_arm_rel(loc, tsym, r_type); 1452 break; 1453 case EM_MIPS: 1454 taddr = addend_mips_rel(loc, r_type); 1455 break; 1456 default: 1457 fatal("Please add code to calculate addend for this architecture\n"); 1458 } 1459 1460 check_section_mismatch(mod, elf, tsym, 1461 fsecndx, fromsec, r_offset, taddr); 1462 } 1463 } 1464 1465 /** 1466 * A module includes a number of sections that are discarded 1467 * either when loaded or when used as built-in. 1468 * For loaded modules all functions marked __init and all data 1469 * marked __initdata will be discarded when the module has been initialized. 1470 * Likewise for modules used built-in the sections marked __exit 1471 * are discarded because __exit marked function are supposed to be called 1472 * only when a module is unloaded which never happens for built-in modules. 1473 * The check_sec_ref() function traverses all relocation records 1474 * to find all references to a section that reference a section that will 1475 * be discarded and warns about it. 1476 **/ 1477 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1478 { 1479 int i; 1480 1481 /* Walk through all sections */ 1482 for (i = 0; i < elf->num_sections; i++) { 1483 Elf_Shdr *sechdr = &elf->sechdrs[i]; 1484 1485 check_section(mod->name, elf, sechdr); 1486 /* We want to process only relocation sections and not .init */ 1487 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) { 1488 /* section to which the relocation applies */ 1489 unsigned int secndx = sechdr->sh_info; 1490 const char *secname = sec_name(elf, secndx); 1491 const void *start, *stop; 1492 1493 /* If the section is known good, skip it */ 1494 if (match(secname, section_white_list)) 1495 continue; 1496 1497 start = sym_get_data_by_offset(elf, i, 0); 1498 stop = start + sechdr->sh_size; 1499 1500 if (sechdr->sh_type == SHT_RELA) 1501 section_rela(mod, elf, secndx, secname, 1502 start, stop); 1503 else 1504 section_rel(mod, elf, secndx, secname, 1505 start, stop); 1506 } 1507 } 1508 } 1509 1510 static char *remove_dot(char *s) 1511 { 1512 size_t n = strcspn(s, "."); 1513 1514 if (n && s[n]) { 1515 size_t m = strspn(s + n + 1, "0123456789"); 1516 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1517 s[n] = 0; 1518 } 1519 return s; 1520 } 1521 1522 /* 1523 * The CRCs are recorded in .*.cmd files in the form of: 1524 * #SYMVER <name> <crc> 1525 */ 1526 static void extract_crcs_for_object(const char *object, struct module *mod) 1527 { 1528 char cmd_file[PATH_MAX]; 1529 char *buf, *p; 1530 const char *base; 1531 int dirlen, ret; 1532 1533 base = strrchr(object, '/'); 1534 if (base) { 1535 base++; 1536 dirlen = base - object; 1537 } else { 1538 dirlen = 0; 1539 base = object; 1540 } 1541 1542 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1543 dirlen, object, base); 1544 if (ret >= sizeof(cmd_file)) { 1545 error("%s: too long path was truncated\n", cmd_file); 1546 return; 1547 } 1548 1549 buf = read_text_file(cmd_file); 1550 p = buf; 1551 1552 while ((p = strstr(p, "\n#SYMVER "))) { 1553 char *name; 1554 size_t namelen; 1555 unsigned int crc; 1556 struct symbol *sym; 1557 1558 name = p + strlen("\n#SYMVER "); 1559 1560 p = strchr(name, ' '); 1561 if (!p) 1562 break; 1563 1564 namelen = p - name; 1565 p++; 1566 1567 if (!isdigit(*p)) 1568 continue; /* skip this line */ 1569 1570 crc = strtoul(p, &p, 0); 1571 if (*p != '\n') 1572 continue; /* skip this line */ 1573 1574 name[namelen] = '\0'; 1575 1576 /* 1577 * sym_find_with_module() may return NULL here. 1578 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1579 * Since commit e1327a127703, genksyms calculates CRCs of all 1580 * symbols, including trimmed ones. Ignore orphan CRCs. 1581 */ 1582 sym = sym_find_with_module(name, mod); 1583 if (sym) 1584 sym_set_crc(sym, crc); 1585 } 1586 1587 free(buf); 1588 } 1589 1590 /* 1591 * The symbol versions (CRC) are recorded in the .*.cmd files. 1592 * Parse them to retrieve CRCs for the current module. 1593 */ 1594 static void mod_set_crcs(struct module *mod) 1595 { 1596 char objlist[PATH_MAX]; 1597 char *buf, *p, *obj; 1598 int ret; 1599 1600 if (mod->is_vmlinux) { 1601 strcpy(objlist, ".vmlinux.objs"); 1602 } else { 1603 /* objects for a module are listed in the *.mod file. */ 1604 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1605 if (ret >= sizeof(objlist)) { 1606 error("%s: too long path was truncated\n", objlist); 1607 return; 1608 } 1609 } 1610 1611 buf = read_text_file(objlist); 1612 p = buf; 1613 1614 while ((obj = strsep(&p, "\n")) && obj[0]) 1615 extract_crcs_for_object(obj, mod); 1616 1617 free(buf); 1618 } 1619 1620 static void read_symbols(const char *modname) 1621 { 1622 const char *symname; 1623 char *version; 1624 char *license; 1625 char *namespace; 1626 struct module *mod; 1627 struct elf_info info = { }; 1628 Elf_Sym *sym; 1629 1630 if (!parse_elf(&info, modname)) 1631 return; 1632 1633 if (!strends(modname, ".o")) { 1634 error("%s: filename must be suffixed with .o\n", modname); 1635 return; 1636 } 1637 1638 /* strip trailing .o */ 1639 mod = new_module(modname, strlen(modname) - strlen(".o")); 1640 1641 if (!mod->is_vmlinux) { 1642 license = get_modinfo(&info, "license"); 1643 if (!license) 1644 error("missing MODULE_LICENSE() in %s\n", modname); 1645 while (license) { 1646 if (!license_is_gpl_compatible(license)) { 1647 mod->is_gpl_compatible = false; 1648 break; 1649 } 1650 license = get_next_modinfo(&info, "license", license); 1651 } 1652 1653 namespace = get_modinfo(&info, "import_ns"); 1654 while (namespace) { 1655 add_namespace(&mod->imported_namespaces, namespace); 1656 namespace = get_next_modinfo(&info, "import_ns", 1657 namespace); 1658 } 1659 } 1660 1661 if (extra_warn && !get_modinfo(&info, "description")) 1662 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1663 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1664 symname = remove_dot(info.strtab + sym->st_name); 1665 1666 handle_symbol(mod, &info, sym, symname); 1667 handle_moddevtable(mod, &info, sym, symname); 1668 } 1669 1670 check_sec_ref(mod, &info); 1671 1672 if (!mod->is_vmlinux) { 1673 version = get_modinfo(&info, "version"); 1674 if (version || all_versions) 1675 get_src_version(mod->name, mod->srcversion, 1676 sizeof(mod->srcversion) - 1); 1677 } 1678 1679 parse_elf_finish(&info); 1680 1681 if (modversions) { 1682 /* 1683 * Our trick to get versioning for module struct etc. - it's 1684 * never passed as an argument to an exported function, so 1685 * the automatic versioning doesn't pick it up, but it's really 1686 * important anyhow. 1687 */ 1688 sym_add_unresolved("module_layout", mod, false); 1689 1690 mod_set_crcs(mod); 1691 } 1692 } 1693 1694 static void read_symbols_from_files(const char *filename) 1695 { 1696 FILE *in = stdin; 1697 char fname[PATH_MAX]; 1698 1699 in = fopen(filename, "r"); 1700 if (!in) 1701 fatal("Can't open filenames file %s: %m", filename); 1702 1703 while (fgets(fname, PATH_MAX, in) != NULL) { 1704 if (strends(fname, "\n")) 1705 fname[strlen(fname)-1] = '\0'; 1706 read_symbols(fname); 1707 } 1708 1709 fclose(in); 1710 } 1711 1712 #define SZ 500 1713 1714 /* We first write the generated file into memory using the 1715 * following helper, then compare to the file on disk and 1716 * only update the later if anything changed */ 1717 1718 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1719 const char *fmt, ...) 1720 { 1721 char tmp[SZ]; 1722 int len; 1723 va_list ap; 1724 1725 va_start(ap, fmt); 1726 len = vsnprintf(tmp, SZ, fmt, ap); 1727 buf_write(buf, tmp, len); 1728 va_end(ap); 1729 } 1730 1731 void buf_write(struct buffer *buf, const char *s, int len) 1732 { 1733 if (buf->size - buf->pos < len) { 1734 buf->size += len + SZ; 1735 buf->p = NOFAIL(realloc(buf->p, buf->size)); 1736 } 1737 strncpy(buf->p + buf->pos, s, len); 1738 buf->pos += len; 1739 } 1740 1741 static void check_exports(struct module *mod) 1742 { 1743 struct symbol *s, *exp; 1744 1745 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1746 const char *basename; 1747 exp = find_symbol(s->name); 1748 if (!exp) { 1749 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1750 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, 1751 "\"%s\" [%s.ko] undefined!\n", 1752 s->name, mod->name); 1753 continue; 1754 } 1755 if (exp->module == mod) { 1756 error("\"%s\" [%s.ko] was exported without definition\n", 1757 s->name, mod->name); 1758 continue; 1759 } 1760 1761 exp->used = true; 1762 s->module = exp->module; 1763 s->crc_valid = exp->crc_valid; 1764 s->crc = exp->crc; 1765 1766 basename = strrchr(mod->name, '/'); 1767 if (basename) 1768 basename++; 1769 else 1770 basename = mod->name; 1771 1772 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1773 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, 1774 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1775 basename, exp->name, exp->namespace); 1776 add_namespace(&mod->missing_namespaces, exp->namespace); 1777 } 1778 1779 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1780 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1781 basename, exp->name); 1782 } 1783 } 1784 1785 static void handle_white_list_exports(const char *white_list) 1786 { 1787 char *buf, *p, *name; 1788 1789 buf = read_text_file(white_list); 1790 p = buf; 1791 1792 while ((name = strsep(&p, "\n"))) { 1793 struct symbol *sym = find_symbol(name); 1794 1795 if (sym) 1796 sym->used = true; 1797 } 1798 1799 free(buf); 1800 } 1801 1802 static void check_modname_len(struct module *mod) 1803 { 1804 const char *mod_name; 1805 1806 mod_name = strrchr(mod->name, '/'); 1807 if (mod_name == NULL) 1808 mod_name = mod->name; 1809 else 1810 mod_name++; 1811 if (strlen(mod_name) >= MODULE_NAME_LEN) 1812 error("module name is too long [%s.ko]\n", mod->name); 1813 } 1814 1815 /** 1816 * Header for the generated file 1817 **/ 1818 static void add_header(struct buffer *b, struct module *mod) 1819 { 1820 buf_printf(b, "#include <linux/module.h>\n"); 1821 /* 1822 * Include build-salt.h after module.h in order to 1823 * inherit the definitions. 1824 */ 1825 buf_printf(b, "#define INCLUDE_VERMAGIC\n"); 1826 buf_printf(b, "#include <linux/build-salt.h>\n"); 1827 buf_printf(b, "#include <linux/elfnote-lto.h>\n"); 1828 buf_printf(b, "#include <linux/export-internal.h>\n"); 1829 buf_printf(b, "#include <linux/vermagic.h>\n"); 1830 buf_printf(b, "#include <linux/compiler.h>\n"); 1831 buf_printf(b, "\n"); 1832 buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n"); 1833 buf_printf(b, "#include <asm/orc_header.h>\n"); 1834 buf_printf(b, "ORC_HEADER;\n"); 1835 buf_printf(b, "#endif\n"); 1836 buf_printf(b, "\n"); 1837 buf_printf(b, "BUILD_SALT;\n"); 1838 buf_printf(b, "BUILD_LTO_INFO;\n"); 1839 buf_printf(b, "\n"); 1840 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1841 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1842 buf_printf(b, "\n"); 1843 buf_printf(b, "__visible struct module __this_module\n"); 1844 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1845 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1846 if (mod->has_init) 1847 buf_printf(b, "\t.init = init_module,\n"); 1848 if (mod->has_cleanup) 1849 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1850 "\t.exit = cleanup_module,\n" 1851 "#endif\n"); 1852 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1853 buf_printf(b, "};\n"); 1854 1855 if (!external_module) 1856 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1857 1858 buf_printf(b, 1859 "\n" 1860 "#ifdef CONFIG_RETPOLINE\n" 1861 "MODULE_INFO(retpoline, \"Y\");\n" 1862 "#endif\n"); 1863 1864 if (strstarts(mod->name, "drivers/staging")) 1865 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1866 1867 if (strstarts(mod->name, "tools/testing")) 1868 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1869 } 1870 1871 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1872 { 1873 struct symbol *sym; 1874 1875 /* generate struct for exported symbols */ 1876 buf_printf(buf, "\n"); 1877 list_for_each_entry(sym, &mod->exported_symbols, list) { 1878 if (trim_unused_exports && !sym->used) 1879 continue; 1880 1881 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1882 sym->is_func ? "FUNC" : "DATA", sym->name, 1883 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1884 } 1885 1886 if (!modversions) 1887 return; 1888 1889 /* record CRCs for exported symbols */ 1890 buf_printf(buf, "\n"); 1891 list_for_each_entry(sym, &mod->exported_symbols, list) { 1892 if (trim_unused_exports && !sym->used) 1893 continue; 1894 1895 if (!sym->crc_valid) 1896 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1897 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1898 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1899 sym->name); 1900 1901 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1902 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1903 } 1904 } 1905 1906 /** 1907 * Record CRCs for unresolved symbols 1908 **/ 1909 static void add_versions(struct buffer *b, struct module *mod) 1910 { 1911 struct symbol *s; 1912 1913 if (!modversions) 1914 return; 1915 1916 buf_printf(b, "\n"); 1917 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1918 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1919 1920 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1921 if (!s->module) 1922 continue; 1923 if (!s->crc_valid) { 1924 warn("\"%s\" [%s.ko] has no CRC!\n", 1925 s->name, mod->name); 1926 continue; 1927 } 1928 if (strlen(s->name) >= MODULE_NAME_LEN) { 1929 error("too long symbol \"%s\" [%s.ko]\n", 1930 s->name, mod->name); 1931 break; 1932 } 1933 buf_printf(b, "\t{ %#8x, \"%s\" },\n", 1934 s->crc, s->name); 1935 } 1936 1937 buf_printf(b, "};\n"); 1938 } 1939 1940 static void add_depends(struct buffer *b, struct module *mod) 1941 { 1942 struct symbol *s; 1943 int first = 1; 1944 1945 /* Clear ->seen flag of modules that own symbols needed by this. */ 1946 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1947 if (s->module) 1948 s->module->seen = s->module->is_vmlinux; 1949 } 1950 1951 buf_printf(b, "\n"); 1952 buf_printf(b, "MODULE_INFO(depends, \""); 1953 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1954 const char *p; 1955 if (!s->module) 1956 continue; 1957 1958 if (s->module->seen) 1959 continue; 1960 1961 s->module->seen = true; 1962 p = strrchr(s->module->name, '/'); 1963 if (p) 1964 p++; 1965 else 1966 p = s->module->name; 1967 buf_printf(b, "%s%s", first ? "" : ",", p); 1968 first = 0; 1969 } 1970 buf_printf(b, "\");\n"); 1971 } 1972 1973 static void add_srcversion(struct buffer *b, struct module *mod) 1974 { 1975 if (mod->srcversion[0]) { 1976 buf_printf(b, "\n"); 1977 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1978 mod->srcversion); 1979 } 1980 } 1981 1982 static void write_buf(struct buffer *b, const char *fname) 1983 { 1984 FILE *file; 1985 1986 if (error_occurred) 1987 return; 1988 1989 file = fopen(fname, "w"); 1990 if (!file) { 1991 perror(fname); 1992 exit(1); 1993 } 1994 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1995 perror(fname); 1996 exit(1); 1997 } 1998 if (fclose(file) != 0) { 1999 perror(fname); 2000 exit(1); 2001 } 2002 } 2003 2004 static void write_if_changed(struct buffer *b, const char *fname) 2005 { 2006 char *tmp; 2007 FILE *file; 2008 struct stat st; 2009 2010 file = fopen(fname, "r"); 2011 if (!file) 2012 goto write; 2013 2014 if (fstat(fileno(file), &st) < 0) 2015 goto close_write; 2016 2017 if (st.st_size != b->pos) 2018 goto close_write; 2019 2020 tmp = NOFAIL(malloc(b->pos)); 2021 if (fread(tmp, 1, b->pos, file) != b->pos) 2022 goto free_write; 2023 2024 if (memcmp(tmp, b->p, b->pos) != 0) 2025 goto free_write; 2026 2027 free(tmp); 2028 fclose(file); 2029 return; 2030 2031 free_write: 2032 free(tmp); 2033 close_write: 2034 fclose(file); 2035 write: 2036 write_buf(b, fname); 2037 } 2038 2039 static void write_vmlinux_export_c_file(struct module *mod) 2040 { 2041 struct buffer buf = { }; 2042 2043 buf_printf(&buf, 2044 "#include <linux/export-internal.h>\n"); 2045 2046 add_exported_symbols(&buf, mod); 2047 write_if_changed(&buf, ".vmlinux.export.c"); 2048 free(buf.p); 2049 } 2050 2051 /* do sanity checks, and generate *.mod.c file */ 2052 static void write_mod_c_file(struct module *mod) 2053 { 2054 struct buffer buf = { }; 2055 char fname[PATH_MAX]; 2056 int ret; 2057 2058 add_header(&buf, mod); 2059 add_exported_symbols(&buf, mod); 2060 add_versions(&buf, mod); 2061 add_depends(&buf, mod); 2062 add_moddevtable(&buf, mod); 2063 add_srcversion(&buf, mod); 2064 2065 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2066 if (ret >= sizeof(fname)) { 2067 error("%s: too long path was truncated\n", fname); 2068 goto free; 2069 } 2070 2071 write_if_changed(&buf, fname); 2072 2073 free: 2074 free(buf.p); 2075 } 2076 2077 /* parse Module.symvers file. line format: 2078 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2079 **/ 2080 static void read_dump(const char *fname) 2081 { 2082 char *buf, *pos, *line; 2083 2084 buf = read_text_file(fname); 2085 if (!buf) 2086 /* No symbol versions, silently ignore */ 2087 return; 2088 2089 pos = buf; 2090 2091 while ((line = get_line(&pos))) { 2092 char *symname, *namespace, *modname, *d, *export; 2093 unsigned int crc; 2094 struct module *mod; 2095 struct symbol *s; 2096 bool gpl_only; 2097 2098 if (!(symname = strchr(line, '\t'))) 2099 goto fail; 2100 *symname++ = '\0'; 2101 if (!(modname = strchr(symname, '\t'))) 2102 goto fail; 2103 *modname++ = '\0'; 2104 if (!(export = strchr(modname, '\t'))) 2105 goto fail; 2106 *export++ = '\0'; 2107 if (!(namespace = strchr(export, '\t'))) 2108 goto fail; 2109 *namespace++ = '\0'; 2110 2111 crc = strtoul(line, &d, 16); 2112 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2113 goto fail; 2114 2115 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2116 gpl_only = true; 2117 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2118 gpl_only = false; 2119 } else { 2120 error("%s: unknown license %s. skip", symname, export); 2121 continue; 2122 } 2123 2124 mod = find_module(modname); 2125 if (!mod) { 2126 mod = new_module(modname, strlen(modname)); 2127 mod->from_dump = true; 2128 } 2129 s = sym_add_exported(symname, mod, gpl_only, namespace); 2130 sym_set_crc(s, crc); 2131 } 2132 free(buf); 2133 return; 2134 fail: 2135 free(buf); 2136 fatal("parse error in symbol dump file\n"); 2137 } 2138 2139 static void write_dump(const char *fname) 2140 { 2141 struct buffer buf = { }; 2142 struct module *mod; 2143 struct symbol *sym; 2144 2145 list_for_each_entry(mod, &modules, list) { 2146 if (mod->from_dump) 2147 continue; 2148 list_for_each_entry(sym, &mod->exported_symbols, list) { 2149 if (trim_unused_exports && !sym->used) 2150 continue; 2151 2152 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2153 sym->crc, sym->name, mod->name, 2154 sym->is_gpl_only ? "_GPL" : "", 2155 sym->namespace); 2156 } 2157 } 2158 write_buf(&buf, fname); 2159 free(buf.p); 2160 } 2161 2162 static void write_namespace_deps_files(const char *fname) 2163 { 2164 struct module *mod; 2165 struct namespace_list *ns; 2166 struct buffer ns_deps_buf = {}; 2167 2168 list_for_each_entry(mod, &modules, list) { 2169 2170 if (mod->from_dump || list_empty(&mod->missing_namespaces)) 2171 continue; 2172 2173 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2174 2175 list_for_each_entry(ns, &mod->missing_namespaces, list) 2176 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2177 2178 buf_printf(&ns_deps_buf, "\n"); 2179 } 2180 2181 write_if_changed(&ns_deps_buf, fname); 2182 free(ns_deps_buf.p); 2183 } 2184 2185 struct dump_list { 2186 struct list_head list; 2187 const char *file; 2188 }; 2189 2190 int main(int argc, char **argv) 2191 { 2192 struct module *mod; 2193 char *missing_namespace_deps = NULL; 2194 char *unused_exports_white_list = NULL; 2195 char *dump_write = NULL, *files_source = NULL; 2196 int opt; 2197 LIST_HEAD(dump_lists); 2198 struct dump_list *dl, *dl2; 2199 2200 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) { 2201 switch (opt) { 2202 case 'e': 2203 external_module = true; 2204 break; 2205 case 'i': 2206 dl = NOFAIL(malloc(sizeof(*dl))); 2207 dl->file = optarg; 2208 list_add_tail(&dl->list, &dump_lists); 2209 break; 2210 case 'M': 2211 module_enabled = true; 2212 break; 2213 case 'm': 2214 modversions = true; 2215 break; 2216 case 'n': 2217 ignore_missing_files = true; 2218 break; 2219 case 'o': 2220 dump_write = optarg; 2221 break; 2222 case 'a': 2223 all_versions = true; 2224 break; 2225 case 'T': 2226 files_source = optarg; 2227 break; 2228 case 't': 2229 trim_unused_exports = true; 2230 break; 2231 case 'u': 2232 unused_exports_white_list = optarg; 2233 break; 2234 case 'W': 2235 extra_warn = true; 2236 break; 2237 case 'w': 2238 warn_unresolved = true; 2239 break; 2240 case 'E': 2241 sec_mismatch_warn_only = false; 2242 break; 2243 case 'N': 2244 allow_missing_ns_imports = true; 2245 break; 2246 case 'd': 2247 missing_namespace_deps = optarg; 2248 break; 2249 default: 2250 exit(1); 2251 } 2252 } 2253 2254 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2255 read_dump(dl->file); 2256 list_del(&dl->list); 2257 free(dl); 2258 } 2259 2260 while (optind < argc) 2261 read_symbols(argv[optind++]); 2262 2263 if (files_source) 2264 read_symbols_from_files(files_source); 2265 2266 list_for_each_entry(mod, &modules, list) { 2267 if (mod->from_dump || mod->is_vmlinux) 2268 continue; 2269 2270 check_modname_len(mod); 2271 check_exports(mod); 2272 } 2273 2274 if (unused_exports_white_list) 2275 handle_white_list_exports(unused_exports_white_list); 2276 2277 list_for_each_entry(mod, &modules, list) { 2278 if (mod->from_dump) 2279 continue; 2280 2281 if (mod->is_vmlinux) 2282 write_vmlinux_export_c_file(mod); 2283 else 2284 write_mod_c_file(mod); 2285 } 2286 2287 if (missing_namespace_deps) 2288 write_namespace_deps_files(missing_namespace_deps); 2289 2290 if (dump_write) 2291 write_dump(dump_write); 2292 if (sec_mismatch_count && !sec_mismatch_warn_only) 2293 error("Section mismatches detected.\n" 2294 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2295 2296 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2297 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2298 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2299 2300 return error_occurred ? 1 : 0; 2301 } 2302