1 /* Postprocess module symbol versions 2 * 3 * Copyright 2003 Kai Germaschewski 4 * Copyright 2002-2004 Rusty Russell, IBM Corporation 5 * Copyright 2006-2008 Sam Ravnborg 6 * Based in part on module-init-tools/depmod.c,file2alias 7 * 8 * This software may be used and distributed according to the terms 9 * of the GNU General Public License, incorporated herein by reference. 10 * 11 * Usage: modpost vmlinux module1.o module2.o ... 12 */ 13 14 #define _GNU_SOURCE 15 #include <elf.h> 16 #include <fnmatch.h> 17 #include <stdio.h> 18 #include <ctype.h> 19 #include <string.h> 20 #include <limits.h> 21 #include <stdbool.h> 22 #include <errno.h> 23 #include "modpost.h" 24 #include "../../include/linux/license.h" 25 #include "../../include/linux/module_symbol.h" 26 27 static bool module_enabled; 28 /* Are we using CONFIG_MODVERSIONS? */ 29 static bool modversions; 30 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 31 static bool all_versions; 32 /* If we are modposting external module set to 1 */ 33 static bool external_module; 34 /* Only warn about unresolved symbols */ 35 static bool warn_unresolved; 36 37 static int sec_mismatch_count; 38 static bool sec_mismatch_warn_only = true; 39 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */ 40 static bool trim_unused_exports; 41 42 /* ignore missing files */ 43 static bool ignore_missing_files; 44 /* If set to 1, only warn (instead of error) about missing ns imports */ 45 static bool allow_missing_ns_imports; 46 47 static bool error_occurred; 48 49 static bool extra_warn; 50 51 /* 52 * Cut off the warnings when there are too many. This typically occurs when 53 * vmlinux is missing. ('make modules' without building vmlinux.) 54 */ 55 #define MAX_UNRESOLVED_REPORTS 10 56 static unsigned int nr_unresolved; 57 58 /* In kernel, this size is defined in linux/module.h; 59 * here we use Elf_Addr instead of long for covering cross-compile 60 */ 61 62 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) 63 64 void __attribute__((format(printf, 2, 3))) 65 modpost_log(enum loglevel loglevel, const char *fmt, ...) 66 { 67 va_list arglist; 68 69 switch (loglevel) { 70 case LOG_WARN: 71 fprintf(stderr, "WARNING: "); 72 break; 73 case LOG_ERROR: 74 fprintf(stderr, "ERROR: "); 75 break; 76 case LOG_FATAL: 77 fprintf(stderr, "FATAL: "); 78 break; 79 default: /* invalid loglevel, ignore */ 80 break; 81 } 82 83 fprintf(stderr, "modpost: "); 84 85 va_start(arglist, fmt); 86 vfprintf(stderr, fmt, arglist); 87 va_end(arglist); 88 89 if (loglevel == LOG_FATAL) 90 exit(1); 91 if (loglevel == LOG_ERROR) 92 error_occurred = true; 93 } 94 95 static inline bool strends(const char *str, const char *postfix) 96 { 97 if (strlen(str) < strlen(postfix)) 98 return false; 99 100 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; 101 } 102 103 void *do_nofail(void *ptr, const char *expr) 104 { 105 if (!ptr) 106 fatal("Memory allocation failure: %s.\n", expr); 107 108 return ptr; 109 } 110 111 char *read_text_file(const char *filename) 112 { 113 struct stat st; 114 size_t nbytes; 115 int fd; 116 char *buf; 117 118 fd = open(filename, O_RDONLY); 119 if (fd < 0) { 120 perror(filename); 121 exit(1); 122 } 123 124 if (fstat(fd, &st) < 0) { 125 perror(filename); 126 exit(1); 127 } 128 129 buf = NOFAIL(malloc(st.st_size + 1)); 130 131 nbytes = st.st_size; 132 133 while (nbytes) { 134 ssize_t bytes_read; 135 136 bytes_read = read(fd, buf, nbytes); 137 if (bytes_read < 0) { 138 perror(filename); 139 exit(1); 140 } 141 142 nbytes -= bytes_read; 143 } 144 buf[st.st_size] = '\0'; 145 146 close(fd); 147 148 return buf; 149 } 150 151 char *get_line(char **stringp) 152 { 153 char *orig = *stringp, *next; 154 155 /* do not return the unwanted extra line at EOF */ 156 if (!orig || *orig == '\0') 157 return NULL; 158 159 /* don't use strsep here, it is not available everywhere */ 160 next = strchr(orig, '\n'); 161 if (next) 162 *next++ = '\0'; 163 164 *stringp = next; 165 166 return orig; 167 } 168 169 /* A list of all modules we processed */ 170 LIST_HEAD(modules); 171 172 static struct module *find_module(const char *modname) 173 { 174 struct module *mod; 175 176 list_for_each_entry(mod, &modules, list) { 177 if (strcmp(mod->name, modname) == 0) 178 return mod; 179 } 180 return NULL; 181 } 182 183 static struct module *new_module(const char *name, size_t namelen) 184 { 185 struct module *mod; 186 187 mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1)); 188 memset(mod, 0, sizeof(*mod)); 189 190 INIT_LIST_HEAD(&mod->exported_symbols); 191 INIT_LIST_HEAD(&mod->unresolved_symbols); 192 INIT_LIST_HEAD(&mod->missing_namespaces); 193 INIT_LIST_HEAD(&mod->imported_namespaces); 194 195 memcpy(mod->name, name, namelen); 196 mod->name[namelen] = '\0'; 197 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0); 198 199 /* 200 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE() 201 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue 202 * modpost will exit wiht error anyway. 203 */ 204 mod->is_gpl_compatible = true; 205 206 list_add_tail(&mod->list, &modules); 207 208 return mod; 209 } 210 211 /* A hash of all exported symbols, 212 * struct symbol is also used for lists of unresolved symbols */ 213 214 #define SYMBOL_HASH_SIZE 1024 215 216 struct symbol { 217 struct symbol *next; 218 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */ 219 struct module *module; 220 char *namespace; 221 unsigned int crc; 222 bool crc_valid; 223 bool weak; 224 bool is_func; 225 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ 226 bool used; /* there exists a user of this symbol */ 227 char name[]; 228 }; 229 230 static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 231 232 /* This is based on the hash algorithm from gdbm, via tdb */ 233 static inline unsigned int tdb_hash(const char *name) 234 { 235 unsigned value; /* Used to compute the hash value. */ 236 unsigned i; /* Used to cycle through random values. */ 237 238 /* Set the initial value from the key size. */ 239 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++) 240 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 241 242 return (1103515243 * value + 12345); 243 } 244 245 /** 246 * Allocate a new symbols for use in the hash of exported symbols or 247 * the list of unresolved symbols per module 248 **/ 249 static struct symbol *alloc_symbol(const char *name) 250 { 251 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 252 253 memset(s, 0, sizeof(*s)); 254 strcpy(s->name, name); 255 256 return s; 257 } 258 259 /* For the hash of exported symbols */ 260 static void hash_add_symbol(struct symbol *sym) 261 { 262 unsigned int hash; 263 264 hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE; 265 sym->next = symbolhash[hash]; 266 symbolhash[hash] = sym; 267 } 268 269 static void sym_add_unresolved(const char *name, struct module *mod, bool weak) 270 { 271 struct symbol *sym; 272 273 sym = alloc_symbol(name); 274 sym->weak = weak; 275 276 list_add_tail(&sym->list, &mod->unresolved_symbols); 277 } 278 279 static struct symbol *sym_find_with_module(const char *name, struct module *mod) 280 { 281 struct symbol *s; 282 283 /* For our purposes, .foo matches foo. PPC64 needs this. */ 284 if (name[0] == '.') 285 name++; 286 287 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) { 288 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) 289 return s; 290 } 291 return NULL; 292 } 293 294 static struct symbol *find_symbol(const char *name) 295 { 296 return sym_find_with_module(name, NULL); 297 } 298 299 struct namespace_list { 300 struct list_head list; 301 char namespace[]; 302 }; 303 304 static bool contains_namespace(struct list_head *head, const char *namespace) 305 { 306 struct namespace_list *list; 307 308 /* 309 * The default namespace is null string "", which is always implicitly 310 * contained. 311 */ 312 if (!namespace[0]) 313 return true; 314 315 list_for_each_entry(list, head, list) { 316 if (!strcmp(list->namespace, namespace)) 317 return true; 318 } 319 320 return false; 321 } 322 323 static void add_namespace(struct list_head *head, const char *namespace) 324 { 325 struct namespace_list *ns_entry; 326 327 if (!contains_namespace(head, namespace)) { 328 ns_entry = NOFAIL(malloc(sizeof(*ns_entry) + 329 strlen(namespace) + 1)); 330 strcpy(ns_entry->namespace, namespace); 331 list_add_tail(&ns_entry->list, head); 332 } 333 } 334 335 static void *sym_get_data_by_offset(const struct elf_info *info, 336 unsigned int secindex, unsigned long offset) 337 { 338 Elf_Shdr *sechdr = &info->sechdrs[secindex]; 339 340 return (void *)info->hdr + sechdr->sh_offset + offset; 341 } 342 343 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) 344 { 345 return sym_get_data_by_offset(info, get_secindex(info, sym), 346 sym->st_value); 347 } 348 349 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) 350 { 351 return sym_get_data_by_offset(info, info->secindex_strings, 352 sechdr->sh_name); 353 } 354 355 static const char *sec_name(const struct elf_info *info, unsigned int secindex) 356 { 357 /* 358 * If sym->st_shndx is a special section index, there is no 359 * corresponding section header. 360 * Return "" if the index is out of range of info->sechdrs[] array. 361 */ 362 if (secindex >= info->num_sections) 363 return ""; 364 365 return sech_name(info, &info->sechdrs[secindex]); 366 } 367 368 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) 369 370 static struct symbol *sym_add_exported(const char *name, struct module *mod, 371 bool gpl_only, const char *namespace) 372 { 373 struct symbol *s = find_symbol(name); 374 375 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { 376 error("%s: '%s' exported twice. Previous export was in %s%s\n", 377 mod->name, name, s->module->name, 378 s->module->is_vmlinux ? "" : ".ko"); 379 } 380 381 s = alloc_symbol(name); 382 s->module = mod; 383 s->is_gpl_only = gpl_only; 384 s->namespace = NOFAIL(strdup(namespace)); 385 list_add_tail(&s->list, &mod->exported_symbols); 386 hash_add_symbol(s); 387 388 return s; 389 } 390 391 static void sym_set_crc(struct symbol *sym, unsigned int crc) 392 { 393 sym->crc = crc; 394 sym->crc_valid = true; 395 } 396 397 static void *grab_file(const char *filename, size_t *size) 398 { 399 struct stat st; 400 void *map = MAP_FAILED; 401 int fd; 402 403 fd = open(filename, O_RDONLY); 404 if (fd < 0) 405 return NULL; 406 if (fstat(fd, &st)) 407 goto failed; 408 409 *size = st.st_size; 410 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 411 412 failed: 413 close(fd); 414 if (map == MAP_FAILED) 415 return NULL; 416 return map; 417 } 418 419 static void release_file(void *file, size_t size) 420 { 421 munmap(file, size); 422 } 423 424 static int parse_elf(struct elf_info *info, const char *filename) 425 { 426 unsigned int i; 427 Elf_Ehdr *hdr; 428 Elf_Shdr *sechdrs; 429 Elf_Sym *sym; 430 const char *secstrings; 431 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 432 433 hdr = grab_file(filename, &info->size); 434 if (!hdr) { 435 if (ignore_missing_files) { 436 fprintf(stderr, "%s: %s (ignored)\n", filename, 437 strerror(errno)); 438 return 0; 439 } 440 perror(filename); 441 exit(1); 442 } 443 info->hdr = hdr; 444 if (info->size < sizeof(*hdr)) { 445 /* file too small, assume this is an empty .o file */ 446 return 0; 447 } 448 /* Is this a valid ELF file? */ 449 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 450 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 451 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 452 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 453 /* Not an ELF file - silently ignore it */ 454 return 0; 455 } 456 /* Fix endianness in ELF header */ 457 hdr->e_type = TO_NATIVE(hdr->e_type); 458 hdr->e_machine = TO_NATIVE(hdr->e_machine); 459 hdr->e_version = TO_NATIVE(hdr->e_version); 460 hdr->e_entry = TO_NATIVE(hdr->e_entry); 461 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 462 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 463 hdr->e_flags = TO_NATIVE(hdr->e_flags); 464 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 465 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 466 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 467 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 468 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 469 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 470 sechdrs = (void *)hdr + hdr->e_shoff; 471 info->sechdrs = sechdrs; 472 473 /* modpost only works for relocatable objects */ 474 if (hdr->e_type != ET_REL) 475 fatal("%s: not relocatable object.", filename); 476 477 /* Check if file offset is correct */ 478 if (hdr->e_shoff > info->size) { 479 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", 480 (unsigned long)hdr->e_shoff, filename, info->size); 481 return 0; 482 } 483 484 if (hdr->e_shnum == SHN_UNDEF) { 485 /* 486 * There are more than 64k sections, 487 * read count from .sh_size. 488 */ 489 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 490 } 491 else { 492 info->num_sections = hdr->e_shnum; 493 } 494 if (hdr->e_shstrndx == SHN_XINDEX) { 495 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 496 } 497 else { 498 info->secindex_strings = hdr->e_shstrndx; 499 } 500 501 /* Fix endianness in section headers */ 502 for (i = 0; i < info->num_sections; i++) { 503 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 504 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 505 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 506 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 507 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 508 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 509 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 510 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 511 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 512 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 513 } 514 /* Find symbol table. */ 515 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 516 for (i = 1; i < info->num_sections; i++) { 517 const char *secname; 518 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 519 520 if (!nobits && sechdrs[i].sh_offset > info->size) { 521 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n", 522 filename, (unsigned long)sechdrs[i].sh_offset, 523 sizeof(*hdr)); 524 return 0; 525 } 526 secname = secstrings + sechdrs[i].sh_name; 527 if (strcmp(secname, ".modinfo") == 0) { 528 if (nobits) 529 fatal("%s has NOBITS .modinfo\n", filename); 530 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 531 info->modinfo_len = sechdrs[i].sh_size; 532 } else if (!strcmp(secname, ".export_symbol")) { 533 info->export_symbol_secndx = i; 534 } 535 536 if (sechdrs[i].sh_type == SHT_SYMTAB) { 537 unsigned int sh_link_idx; 538 symtab_idx = i; 539 info->symtab_start = (void *)hdr + 540 sechdrs[i].sh_offset; 541 info->symtab_stop = (void *)hdr + 542 sechdrs[i].sh_offset + sechdrs[i].sh_size; 543 sh_link_idx = sechdrs[i].sh_link; 544 info->strtab = (void *)hdr + 545 sechdrs[sh_link_idx].sh_offset; 546 } 547 548 /* 32bit section no. table? ("more than 64k sections") */ 549 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 550 symtab_shndx_idx = i; 551 info->symtab_shndx_start = (void *)hdr + 552 sechdrs[i].sh_offset; 553 info->symtab_shndx_stop = (void *)hdr + 554 sechdrs[i].sh_offset + sechdrs[i].sh_size; 555 } 556 } 557 if (!info->symtab_start) 558 fatal("%s has no symtab?\n", filename); 559 560 /* Fix endianness in symbols */ 561 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 562 sym->st_shndx = TO_NATIVE(sym->st_shndx); 563 sym->st_name = TO_NATIVE(sym->st_name); 564 sym->st_value = TO_NATIVE(sym->st_value); 565 sym->st_size = TO_NATIVE(sym->st_size); 566 } 567 568 if (symtab_shndx_idx != ~0U) { 569 Elf32_Word *p; 570 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 571 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 572 filename, sechdrs[symtab_shndx_idx].sh_link, 573 symtab_idx); 574 /* Fix endianness */ 575 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 576 p++) 577 *p = TO_NATIVE(*p); 578 } 579 580 return 1; 581 } 582 583 static void parse_elf_finish(struct elf_info *info) 584 { 585 release_file(info->hdr, info->size); 586 } 587 588 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 589 { 590 /* ignore __this_module, it will be resolved shortly */ 591 if (strcmp(symname, "__this_module") == 0) 592 return 1; 593 /* ignore global offset table */ 594 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 595 return 1; 596 if (info->hdr->e_machine == EM_PPC) 597 /* Special register function linked on all modules during final link of .ko */ 598 if (strstarts(symname, "_restgpr_") || 599 strstarts(symname, "_savegpr_") || 600 strstarts(symname, "_rest32gpr_") || 601 strstarts(symname, "_save32gpr_") || 602 strstarts(symname, "_restvr_") || 603 strstarts(symname, "_savevr_")) 604 return 1; 605 if (info->hdr->e_machine == EM_PPC64) 606 /* Special register function linked on all modules during final link of .ko */ 607 if (strstarts(symname, "_restgpr0_") || 608 strstarts(symname, "_savegpr0_") || 609 strstarts(symname, "_restvr_") || 610 strstarts(symname, "_savevr_") || 611 strcmp(symname, ".TOC.") == 0) 612 return 1; 613 614 if (info->hdr->e_machine == EM_S390) 615 /* Expoline thunks are linked on all kernel modules during final link of .ko */ 616 if (strstarts(symname, "__s390_indirect_jump_r")) 617 return 1; 618 /* Do not ignore this symbol */ 619 return 0; 620 } 621 622 static void handle_symbol(struct module *mod, struct elf_info *info, 623 const Elf_Sym *sym, const char *symname) 624 { 625 switch (sym->st_shndx) { 626 case SHN_COMMON: 627 if (strstarts(symname, "__gnu_lto_")) { 628 /* Should warn here, but modpost runs before the linker */ 629 } else 630 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 631 break; 632 case SHN_UNDEF: 633 /* undefined symbol */ 634 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 635 ELF_ST_BIND(sym->st_info) != STB_WEAK) 636 break; 637 if (ignore_undef_symbol(info, symname)) 638 break; 639 if (info->hdr->e_machine == EM_SPARC || 640 info->hdr->e_machine == EM_SPARCV9) { 641 /* Ignore register directives. */ 642 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 643 break; 644 if (symname[0] == '.') { 645 char *munged = NOFAIL(strdup(symname)); 646 munged[0] = '_'; 647 munged[1] = toupper(munged[1]); 648 symname = munged; 649 } 650 } 651 652 sym_add_unresolved(symname, mod, 653 ELF_ST_BIND(sym->st_info) == STB_WEAK); 654 break; 655 default: 656 if (strcmp(symname, "init_module") == 0) 657 mod->has_init = true; 658 if (strcmp(symname, "cleanup_module") == 0) 659 mod->has_cleanup = true; 660 break; 661 } 662 } 663 664 /** 665 * Parse tag=value strings from .modinfo section 666 **/ 667 static char *next_string(char *string, unsigned long *secsize) 668 { 669 /* Skip non-zero chars */ 670 while (string[0]) { 671 string++; 672 if ((*secsize)-- <= 1) 673 return NULL; 674 } 675 676 /* Skip any zero padding. */ 677 while (!string[0]) { 678 string++; 679 if ((*secsize)-- <= 1) 680 return NULL; 681 } 682 return string; 683 } 684 685 static char *get_next_modinfo(struct elf_info *info, const char *tag, 686 char *prev) 687 { 688 char *p; 689 unsigned int taglen = strlen(tag); 690 char *modinfo = info->modinfo; 691 unsigned long size = info->modinfo_len; 692 693 if (prev) { 694 size -= prev - modinfo; 695 modinfo = next_string(prev, &size); 696 } 697 698 for (p = modinfo; p; p = next_string(p, &size)) { 699 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 700 return p + taglen + 1; 701 } 702 return NULL; 703 } 704 705 static char *get_modinfo(struct elf_info *info, const char *tag) 706 707 { 708 return get_next_modinfo(info, tag, NULL); 709 } 710 711 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 712 { 713 if (sym) 714 return elf->strtab + sym->st_name; 715 else 716 return "(unknown)"; 717 } 718 719 /* 720 * Check whether the 'string' argument matches one of the 'patterns', 721 * an array of shell wildcard patterns (glob). 722 * 723 * Return true is there is a match. 724 */ 725 static bool match(const char *string, const char *const patterns[]) 726 { 727 const char *pattern; 728 729 while ((pattern = *patterns++)) { 730 if (!fnmatch(pattern, string, 0)) 731 return true; 732 } 733 734 return false; 735 } 736 737 /* useful to pass patterns to match() directly */ 738 #define PATTERNS(...) \ 739 ({ \ 740 static const char *const patterns[] = {__VA_ARGS__, NULL}; \ 741 patterns; \ 742 }) 743 744 /* sections that we do not want to do full section mismatch check on */ 745 static const char *const section_white_list[] = 746 { 747 ".comment*", 748 ".debug*", 749 ".zdebug*", /* Compressed debug sections. */ 750 ".GCC.command.line", /* record-gcc-switches */ 751 ".mdebug*", /* alpha, score, mips etc. */ 752 ".pdr", /* alpha, score, mips etc. */ 753 ".stab*", 754 ".note*", 755 ".got*", 756 ".toc*", 757 ".xt.prop", /* xtensa */ 758 ".xt.lit", /* xtensa */ 759 ".arcextmap*", /* arc */ 760 ".gnu.linkonce.arcext*", /* arc : modules */ 761 ".cmem*", /* EZchip */ 762 ".fmt_slot*", /* EZchip */ 763 ".gnu.lto*", 764 ".discard.*", 765 ".llvm.call-graph-profile", /* call graph */ 766 NULL 767 }; 768 769 /* 770 * This is used to find sections missing the SHF_ALLOC flag. 771 * The cause of this is often a section specified in assembler 772 * without "ax" / "aw". 773 */ 774 static void check_section(const char *modname, struct elf_info *elf, 775 Elf_Shdr *sechdr) 776 { 777 const char *sec = sech_name(elf, sechdr); 778 779 if (sechdr->sh_type == SHT_PROGBITS && 780 !(sechdr->sh_flags & SHF_ALLOC) && 781 !match(sec, section_white_list)) { 782 warn("%s (%s): unexpected non-allocatable section.\n" 783 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 784 "Note that for example <linux/init.h> contains\n" 785 "section definitions for use in .S files.\n\n", 786 modname, sec); 787 } 788 } 789 790 791 792 #define ALL_INIT_DATA_SECTIONS \ 793 ".init.setup", ".init.rodata", ".meminit.rodata", \ 794 ".init.data", ".meminit.data" 795 #define ALL_EXIT_DATA_SECTIONS \ 796 ".exit.data", ".memexit.data" 797 798 #define ALL_INIT_TEXT_SECTIONS \ 799 ".init.text", ".meminit.text" 800 #define ALL_EXIT_TEXT_SECTIONS \ 801 ".exit.text", ".memexit.text" 802 803 #define ALL_PCI_INIT_SECTIONS \ 804 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 805 ".pci_fixup_enable", ".pci_fixup_resume", \ 806 ".pci_fixup_resume_early", ".pci_fixup_suspend" 807 808 #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS 809 #define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS 810 811 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 812 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS 813 814 #define DATA_SECTIONS ".data", ".data.rel" 815 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ 816 ".kprobes.text", ".cpuidle.text", ".noinstr.text" 817 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ 818 ".fixup", ".entry.text", ".exception.text", \ 819 ".coldtext", ".softirqentry.text" 820 821 #define INIT_SECTIONS ".init.*" 822 #define MEM_INIT_SECTIONS ".meminit.*" 823 824 #define EXIT_SECTIONS ".exit.*" 825 #define MEM_EXIT_SECTIONS ".memexit.*" 826 827 #define ALL_TEXT_SECTIONS ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \ 828 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 829 830 enum mismatch { 831 TEXT_TO_ANY_INIT, 832 DATA_TO_ANY_INIT, 833 TEXTDATA_TO_ANY_EXIT, 834 XXXINIT_TO_SOME_INIT, 835 XXXEXIT_TO_SOME_EXIT, 836 ANY_INIT_TO_ANY_EXIT, 837 ANY_EXIT_TO_ANY_INIT, 838 EXTABLE_TO_NON_TEXT, 839 }; 840 841 /** 842 * Describe how to match sections on different criteria: 843 * 844 * @fromsec: Array of sections to be matched. 845 * 846 * @bad_tosec: Relocations applied to a section in @fromsec to a section in 847 * this array is forbidden (black-list). Can be empty. 848 * 849 * @good_tosec: Relocations applied to a section in @fromsec must be 850 * targeting sections in this array (white-list). Can be empty. 851 * 852 * @mismatch: Type of mismatch. 853 */ 854 struct sectioncheck { 855 const char *fromsec[20]; 856 const char *bad_tosec[20]; 857 const char *good_tosec[20]; 858 enum mismatch mismatch; 859 }; 860 861 static const struct sectioncheck sectioncheck[] = { 862 /* Do not reference init/exit code/data from 863 * normal code and data 864 */ 865 { 866 .fromsec = { TEXT_SECTIONS, NULL }, 867 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 868 .mismatch = TEXT_TO_ANY_INIT, 869 }, 870 { 871 .fromsec = { DATA_SECTIONS, NULL }, 872 .bad_tosec = { ALL_XXXINIT_SECTIONS, INIT_SECTIONS, NULL }, 873 .mismatch = DATA_TO_ANY_INIT, 874 }, 875 { 876 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 877 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 878 .mismatch = TEXTDATA_TO_ANY_EXIT, 879 }, 880 /* Do not reference init code/data from meminit code/data */ 881 { 882 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 883 .bad_tosec = { INIT_SECTIONS, NULL }, 884 .mismatch = XXXINIT_TO_SOME_INIT, 885 }, 886 /* Do not reference exit code/data from memexit code/data */ 887 { 888 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL }, 889 .bad_tosec = { EXIT_SECTIONS, NULL }, 890 .mismatch = XXXEXIT_TO_SOME_EXIT, 891 }, 892 /* Do not use exit code/data from init code */ 893 { 894 .fromsec = { ALL_INIT_SECTIONS, NULL }, 895 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 896 .mismatch = ANY_INIT_TO_ANY_EXIT, 897 }, 898 /* Do not use init code/data from exit code */ 899 { 900 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 901 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 902 .mismatch = ANY_EXIT_TO_ANY_INIT, 903 }, 904 { 905 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 906 .bad_tosec = { INIT_SECTIONS, NULL }, 907 .mismatch = ANY_INIT_TO_ANY_EXIT, 908 }, 909 { 910 .fromsec = { "__ex_table", NULL }, 911 /* If you're adding any new black-listed sections in here, consider 912 * adding a special 'printer' for them in scripts/check_extable. 913 */ 914 .bad_tosec = { ".altinstr_replacement", NULL }, 915 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 916 .mismatch = EXTABLE_TO_NON_TEXT, 917 } 918 }; 919 920 static const struct sectioncheck *section_mismatch( 921 const char *fromsec, const char *tosec) 922 { 923 int i; 924 925 /* 926 * The target section could be the SHT_NUL section when we're 927 * handling relocations to un-resolved symbols, trying to match it 928 * doesn't make much sense and causes build failures on parisc 929 * architectures. 930 */ 931 if (*tosec == '\0') 932 return NULL; 933 934 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 935 const struct sectioncheck *check = §ioncheck[i]; 936 937 if (match(fromsec, check->fromsec)) { 938 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 939 return check; 940 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 941 return check; 942 } 943 } 944 return NULL; 945 } 946 947 /** 948 * Whitelist to allow certain references to pass with no warning. 949 * 950 * Pattern 1: 951 * If a module parameter is declared __initdata and permissions=0 952 * then this is legal despite the warning generated. 953 * We cannot see value of permissions here, so just ignore 954 * this pattern. 955 * The pattern is identified by: 956 * tosec = .init.data 957 * fromsec = .data* 958 * atsym =__param* 959 * 960 * Pattern 1a: 961 * module_param_call() ops can refer to __init set function if permissions=0 962 * The pattern is identified by: 963 * tosec = .init.text 964 * fromsec = .data* 965 * atsym = __param_ops_* 966 * 967 * Pattern 3: 968 * Whitelist all references from .head.text to any init section 969 * 970 * Pattern 4: 971 * Some symbols belong to init section but still it is ok to reference 972 * these from non-init sections as these symbols don't have any memory 973 * allocated for them and symbol address and value are same. So even 974 * if init section is freed, its ok to reference those symbols. 975 * For ex. symbols marking the init section boundaries. 976 * This pattern is identified by 977 * refsymname = __init_begin, _sinittext, _einittext 978 * 979 * Pattern 5: 980 * GCC may optimize static inlines when fed constant arg(s) resulting 981 * in functions like cpumask_empty() -- generating an associated symbol 982 * cpumask_empty.constprop.3 that appears in the audit. If the const that 983 * is passed in comes from __init, like say nmi_ipi_mask, we get a 984 * meaningless section warning. May need to add isra symbols too... 985 * This pattern is identified by 986 * tosec = init section 987 * fromsec = text section 988 * refsymname = *.constprop.* 989 * 990 **/ 991 static int secref_whitelist(const char *fromsec, const char *fromsym, 992 const char *tosec, const char *tosym) 993 { 994 /* Check for pattern 1 */ 995 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 996 match(fromsec, PATTERNS(DATA_SECTIONS)) && 997 strstarts(fromsym, "__param")) 998 return 0; 999 1000 /* Check for pattern 1a */ 1001 if (strcmp(tosec, ".init.text") == 0 && 1002 match(fromsec, PATTERNS(DATA_SECTIONS)) && 1003 strstarts(fromsym, "__param_ops_")) 1004 return 0; 1005 1006 /* symbols in data sections that may refer to any init/exit sections */ 1007 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 1008 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 1009 match(fromsym, PATTERNS("*_template", // scsi uses *_template a lot 1010 "*_timer", // arm uses ops structures named _timer a lot 1011 "*_sht", // scsi also used *_sht to some extent 1012 "*_ops", 1013 "*_probe", 1014 "*_probe_one", 1015 "*_console"))) 1016 return 0; 1017 1018 /* symbols in data sections that may refer to meminit/exit sections */ 1019 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 1020 match(tosec, PATTERNS(ALL_XXXINIT_SECTIONS, ALL_EXIT_SECTIONS)) && 1021 match(fromsym, PATTERNS("*driver"))) 1022 return 0; 1023 1024 /* Check for pattern 3 */ 1025 if (strstarts(fromsec, ".head.text") && 1026 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 1027 return 0; 1028 1029 /* Check for pattern 4 */ 1030 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 1031 return 0; 1032 1033 /* Check for pattern 5 */ 1034 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 1035 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 1036 match(fromsym, PATTERNS("*.constprop.*"))) 1037 return 0; 1038 1039 return 1; 1040 } 1041 1042 /* 1043 * If there's no name there, ignore it; likewise, ignore it if it's 1044 * one of the magic symbols emitted used by current tools. 1045 * 1046 * Otherwise if find_symbols_between() returns those symbols, they'll 1047 * fail the whitelist tests and cause lots of false alarms ... fixable 1048 * only by merging __exit and __init sections into __text, bloating 1049 * the kernel (which is especially evil on embedded platforms). 1050 */ 1051 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 1052 { 1053 const char *name = elf->strtab + sym->st_name; 1054 1055 if (!name || !strlen(name)) 1056 return 0; 1057 return !is_mapping_symbol(name); 1058 } 1059 1060 /* Look up the nearest symbol based on the section and the address */ 1061 static Elf_Sym *find_nearest_sym(struct elf_info *elf, Elf_Addr addr, 1062 unsigned int secndx, bool allow_negative, 1063 Elf_Addr min_distance) 1064 { 1065 Elf_Sym *sym; 1066 Elf_Sym *near = NULL; 1067 Elf_Addr sym_addr, distance; 1068 bool is_arm = (elf->hdr->e_machine == EM_ARM); 1069 1070 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1071 if (get_secindex(elf, sym) != secndx) 1072 continue; 1073 if (!is_valid_name(elf, sym)) 1074 continue; 1075 1076 sym_addr = sym->st_value; 1077 1078 /* 1079 * For ARM Thumb instruction, the bit 0 of st_value is set 1080 * if the symbol is STT_FUNC type. Mask it to get the address. 1081 */ 1082 if (is_arm && ELF_ST_TYPE(sym->st_info) == STT_FUNC) 1083 sym_addr &= ~1; 1084 1085 if (addr >= sym_addr) 1086 distance = addr - sym_addr; 1087 else if (allow_negative) 1088 distance = sym_addr - addr; 1089 else 1090 continue; 1091 1092 if (distance <= min_distance) { 1093 min_distance = distance; 1094 near = sym; 1095 } 1096 1097 if (min_distance == 0) 1098 break; 1099 } 1100 return near; 1101 } 1102 1103 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 1104 unsigned int secndx) 1105 { 1106 return find_nearest_sym(elf, addr, secndx, false, ~0); 1107 } 1108 1109 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 1110 { 1111 /* If the supplied symbol has a valid name, return it */ 1112 if (is_valid_name(elf, sym)) 1113 return sym; 1114 1115 /* 1116 * Strive to find a better symbol name, but the resulting name may not 1117 * match the symbol referenced in the original code. 1118 */ 1119 return find_nearest_sym(elf, addr, get_secindex(elf, sym), true, 20); 1120 } 1121 1122 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1123 { 1124 if (secndx >= elf->num_sections) 1125 return false; 1126 1127 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1128 } 1129 1130 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1131 const struct sectioncheck* const mismatch, 1132 Elf_Sym *tsym, 1133 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1134 const char *tosec, Elf_Addr taddr) 1135 { 1136 Elf_Sym *from; 1137 const char *tosym; 1138 const char *fromsym; 1139 1140 from = find_fromsym(elf, faddr, fsecndx); 1141 fromsym = sym_name(elf, from); 1142 1143 tsym = find_tosym(elf, taddr, tsym); 1144 tosym = sym_name(elf, tsym); 1145 1146 /* check whitelist - we may ignore it */ 1147 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1148 return; 1149 1150 sec_mismatch_count++; 1151 1152 warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n", 1153 modname, fromsym, (unsigned int)(faddr - from->st_value), fromsec, tosym, tosec); 1154 1155 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1156 if (match(tosec, mismatch->bad_tosec)) 1157 fatal("The relocation at %s+0x%lx references\n" 1158 "section \"%s\" which is black-listed.\n" 1159 "Something is seriously wrong and should be fixed.\n" 1160 "You might get more information about where this is\n" 1161 "coming from by using scripts/check_extable.sh %s\n", 1162 fromsec, (long)faddr, tosec, modname); 1163 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1164 warn("The relocation at %s+0x%lx references\n" 1165 "section \"%s\" which is not in the list of\n" 1166 "authorized sections. If you're adding a new section\n" 1167 "and/or if this reference is valid, add \"%s\" to the\n" 1168 "list of authorized sections to jump to on fault.\n" 1169 "This can be achieved by adding \"%s\" to\n" 1170 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1171 fromsec, (long)faddr, tosec, tosec, tosec); 1172 else 1173 error("%s+0x%lx references non-executable section '%s'\n", 1174 fromsec, (long)faddr, tosec); 1175 } 1176 } 1177 1178 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1179 Elf_Addr faddr, const char *secname, 1180 Elf_Sym *sym) 1181 { 1182 static const char *prefix = "__export_symbol_"; 1183 const char *label_name, *name, *data; 1184 Elf_Sym *label; 1185 struct symbol *s; 1186 bool is_gpl; 1187 1188 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1189 label_name = sym_name(elf, label); 1190 1191 if (!strstarts(label_name, prefix)) { 1192 error("%s: .export_symbol section contains strange symbol '%s'\n", 1193 mod->name, label_name); 1194 return; 1195 } 1196 1197 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1198 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1199 error("%s: local symbol '%s' was exported\n", mod->name, 1200 label_name + strlen(prefix)); 1201 return; 1202 } 1203 1204 name = sym_name(elf, sym); 1205 if (strcmp(label_name + strlen(prefix), name)) { 1206 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1207 mod->name, name); 1208 return; 1209 } 1210 1211 data = sym_get_data(elf, label); /* license */ 1212 if (!strcmp(data, "GPL")) { 1213 is_gpl = true; 1214 } else if (!strcmp(data, "")) { 1215 is_gpl = false; 1216 } else { 1217 error("%s: unknown license '%s' was specified for '%s'\n", 1218 mod->name, data, name); 1219 return; 1220 } 1221 1222 data += strlen(data) + 1; /* namespace */ 1223 s = sym_add_exported(name, mod, is_gpl, data); 1224 1225 /* 1226 * We need to be aware whether we are exporting a function or 1227 * a data on some architectures. 1228 */ 1229 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1230 1231 /* 1232 * For parisc64, symbols prefixed $$ from the library have the symbol type 1233 * STT_LOPROC. They should be handled as functions too. 1234 */ 1235 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1236 elf->hdr->e_machine == EM_PARISC && 1237 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1238 s->is_func = true; 1239 1240 if (match(secname, PATTERNS(INIT_SECTIONS))) 1241 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1242 mod->name, name); 1243 else if (match(secname, PATTERNS(EXIT_SECTIONS))) 1244 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1245 mod->name, name); 1246 } 1247 1248 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1249 Elf_Sym *sym, 1250 unsigned int fsecndx, const char *fromsec, 1251 Elf_Addr faddr, Elf_Addr taddr) 1252 { 1253 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1254 const struct sectioncheck *mismatch; 1255 1256 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1257 check_export_symbol(mod, elf, faddr, tosec, sym); 1258 return; 1259 } 1260 1261 mismatch = section_mismatch(fromsec, tosec); 1262 if (!mismatch) 1263 return; 1264 1265 default_mismatch_handler(mod->name, elf, mismatch, sym, 1266 fsecndx, fromsec, faddr, 1267 tosec, taddr); 1268 } 1269 1270 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1271 { 1272 switch (r_type) { 1273 case R_386_32: 1274 return TO_NATIVE(*location); 1275 case R_386_PC32: 1276 return TO_NATIVE(*location) + 4; 1277 } 1278 1279 return (Elf_Addr)(-1); 1280 } 1281 1282 #ifndef R_ARM_CALL 1283 #define R_ARM_CALL 28 1284 #endif 1285 #ifndef R_ARM_JUMP24 1286 #define R_ARM_JUMP24 29 1287 #endif 1288 1289 #ifndef R_ARM_THM_CALL 1290 #define R_ARM_THM_CALL 10 1291 #endif 1292 #ifndef R_ARM_THM_JUMP24 1293 #define R_ARM_THM_JUMP24 30 1294 #endif 1295 1296 #ifndef R_ARM_MOVW_ABS_NC 1297 #define R_ARM_MOVW_ABS_NC 43 1298 #endif 1299 1300 #ifndef R_ARM_MOVT_ABS 1301 #define R_ARM_MOVT_ABS 44 1302 #endif 1303 1304 #ifndef R_ARM_THM_MOVW_ABS_NC 1305 #define R_ARM_THM_MOVW_ABS_NC 47 1306 #endif 1307 1308 #ifndef R_ARM_THM_MOVT_ABS 1309 #define R_ARM_THM_MOVT_ABS 48 1310 #endif 1311 1312 #ifndef R_ARM_THM_JUMP19 1313 #define R_ARM_THM_JUMP19 51 1314 #endif 1315 1316 static int32_t sign_extend32(int32_t value, int index) 1317 { 1318 uint8_t shift = 31 - index; 1319 1320 return (int32_t)(value << shift) >> shift; 1321 } 1322 1323 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1324 { 1325 uint32_t inst, upper, lower, sign, j1, j2; 1326 int32_t offset; 1327 1328 switch (r_type) { 1329 case R_ARM_ABS32: 1330 case R_ARM_REL32: 1331 inst = TO_NATIVE(*(uint32_t *)loc); 1332 return inst + sym->st_value; 1333 case R_ARM_MOVW_ABS_NC: 1334 case R_ARM_MOVT_ABS: 1335 inst = TO_NATIVE(*(uint32_t *)loc); 1336 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1337 15); 1338 return offset + sym->st_value; 1339 case R_ARM_PC24: 1340 case R_ARM_CALL: 1341 case R_ARM_JUMP24: 1342 inst = TO_NATIVE(*(uint32_t *)loc); 1343 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1344 return offset + sym->st_value + 8; 1345 case R_ARM_THM_MOVW_ABS_NC: 1346 case R_ARM_THM_MOVT_ABS: 1347 upper = TO_NATIVE(*(uint16_t *)loc); 1348 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1349 offset = sign_extend32(((upper & 0x000f) << 12) | 1350 ((upper & 0x0400) << 1) | 1351 ((lower & 0x7000) >> 4) | 1352 (lower & 0x00ff), 1353 15); 1354 return offset + sym->st_value; 1355 case R_ARM_THM_JUMP19: 1356 /* 1357 * Encoding T3: 1358 * S = upper[10] 1359 * imm6 = upper[5:0] 1360 * J1 = lower[13] 1361 * J2 = lower[11] 1362 * imm11 = lower[10:0] 1363 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1364 */ 1365 upper = TO_NATIVE(*(uint16_t *)loc); 1366 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1367 1368 sign = (upper >> 10) & 1; 1369 j1 = (lower >> 13) & 1; 1370 j2 = (lower >> 11) & 1; 1371 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1372 ((upper & 0x03f) << 12) | 1373 ((lower & 0x07ff) << 1), 1374 20); 1375 return offset + sym->st_value + 4; 1376 case R_ARM_THM_CALL: 1377 case R_ARM_THM_JUMP24: 1378 /* 1379 * Encoding T4: 1380 * S = upper[10] 1381 * imm10 = upper[9:0] 1382 * J1 = lower[13] 1383 * J2 = lower[11] 1384 * imm11 = lower[10:0] 1385 * I1 = NOT(J1 XOR S) 1386 * I2 = NOT(J2 XOR S) 1387 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1388 */ 1389 upper = TO_NATIVE(*(uint16_t *)loc); 1390 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1391 1392 sign = (upper >> 10) & 1; 1393 j1 = (lower >> 13) & 1; 1394 j2 = (lower >> 11) & 1; 1395 offset = sign_extend32((sign << 24) | 1396 ((~(j1 ^ sign) & 1) << 23) | 1397 ((~(j2 ^ sign) & 1) << 22) | 1398 ((upper & 0x03ff) << 12) | 1399 ((lower & 0x07ff) << 1), 1400 24); 1401 return offset + sym->st_value + 4; 1402 } 1403 1404 return (Elf_Addr)(-1); 1405 } 1406 1407 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1408 { 1409 uint32_t inst; 1410 1411 inst = TO_NATIVE(*location); 1412 switch (r_type) { 1413 case R_MIPS_LO16: 1414 return inst & 0xffff; 1415 case R_MIPS_26: 1416 return (inst & 0x03ffffff) << 2; 1417 case R_MIPS_32: 1418 return inst; 1419 } 1420 return (Elf_Addr)(-1); 1421 } 1422 1423 #ifndef EM_RISCV 1424 #define EM_RISCV 243 1425 #endif 1426 1427 #ifndef R_RISCV_SUB32 1428 #define R_RISCV_SUB32 39 1429 #endif 1430 1431 #ifndef EM_LOONGARCH 1432 #define EM_LOONGARCH 258 1433 #endif 1434 1435 #ifndef R_LARCH_SUB32 1436 #define R_LARCH_SUB32 55 1437 #endif 1438 1439 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1440 unsigned int *r_type, unsigned int *r_sym) 1441 { 1442 typedef struct { 1443 Elf64_Word r_sym; /* Symbol index */ 1444 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1445 unsigned char r_type3; /* 3rd relocation type */ 1446 unsigned char r_type2; /* 2nd relocation type */ 1447 unsigned char r_type; /* 1st relocation type */ 1448 } Elf64_Mips_R_Info; 1449 1450 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1451 1452 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1453 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1454 1455 *r_type = mips64_r_info->r_type; 1456 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1457 return; 1458 } 1459 1460 if (is_64bit) { 1461 Elf64_Xword r_info64 = r_info; 1462 1463 r_info = TO_NATIVE(r_info64); 1464 } else { 1465 Elf32_Word r_info32 = r_info; 1466 1467 r_info = TO_NATIVE(r_info32); 1468 } 1469 1470 *r_type = ELF_R_TYPE(r_info); 1471 *r_sym = ELF_R_SYM(r_info); 1472 } 1473 1474 static void section_rela(struct module *mod, struct elf_info *elf, 1475 Elf_Shdr *sechdr) 1476 { 1477 Elf_Rela *rela; 1478 unsigned int fsecndx = sechdr->sh_info; 1479 const char *fromsec = sec_name(elf, fsecndx); 1480 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; 1481 Elf_Rela *stop = (void *)start + sechdr->sh_size; 1482 1483 /* if from section (name) is know good then skip it */ 1484 if (match(fromsec, section_white_list)) 1485 return; 1486 1487 for (rela = start; rela < stop; rela++) { 1488 Elf_Addr taddr, r_offset; 1489 unsigned int r_type, r_sym; 1490 1491 r_offset = TO_NATIVE(rela->r_offset); 1492 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1493 1494 taddr = TO_NATIVE(rela->r_addend); 1495 1496 switch (elf->hdr->e_machine) { 1497 case EM_RISCV: 1498 if (!strcmp("__ex_table", fromsec) && 1499 r_type == R_RISCV_SUB32) 1500 continue; 1501 break; 1502 case EM_LOONGARCH: 1503 if (!strcmp("__ex_table", fromsec) && 1504 r_type == R_LARCH_SUB32) 1505 continue; 1506 break; 1507 } 1508 1509 check_section_mismatch(mod, elf, elf->symtab_start + r_sym, 1510 fsecndx, fromsec, r_offset, taddr); 1511 } 1512 } 1513 1514 static void section_rel(struct module *mod, struct elf_info *elf, 1515 Elf_Shdr *sechdr) 1516 { 1517 Elf_Rel *rel; 1518 unsigned int fsecndx = sechdr->sh_info; 1519 const char *fromsec = sec_name(elf, fsecndx); 1520 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset; 1521 Elf_Rel *stop = (void *)start + sechdr->sh_size; 1522 1523 /* if from section (name) is know good then skip it */ 1524 if (match(fromsec, section_white_list)) 1525 return; 1526 1527 for (rel = start; rel < stop; rel++) { 1528 Elf_Sym *tsym; 1529 Elf_Addr taddr = 0, r_offset; 1530 unsigned int r_type, r_sym; 1531 void *loc; 1532 1533 r_offset = TO_NATIVE(rel->r_offset); 1534 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1535 1536 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1537 tsym = elf->symtab_start + r_sym; 1538 1539 switch (elf->hdr->e_machine) { 1540 case EM_386: 1541 taddr = addend_386_rel(loc, r_type); 1542 break; 1543 case EM_ARM: 1544 taddr = addend_arm_rel(loc, tsym, r_type); 1545 break; 1546 case EM_MIPS: 1547 taddr = addend_mips_rel(loc, r_type); 1548 break; 1549 default: 1550 fatal("Please add code to calculate addend for this architecture\n"); 1551 } 1552 1553 check_section_mismatch(mod, elf, tsym, 1554 fsecndx, fromsec, r_offset, taddr); 1555 } 1556 } 1557 1558 /** 1559 * A module includes a number of sections that are discarded 1560 * either when loaded or when used as built-in. 1561 * For loaded modules all functions marked __init and all data 1562 * marked __initdata will be discarded when the module has been initialized. 1563 * Likewise for modules used built-in the sections marked __exit 1564 * are discarded because __exit marked function are supposed to be called 1565 * only when a module is unloaded which never happens for built-in modules. 1566 * The check_sec_ref() function traverses all relocation records 1567 * to find all references to a section that reference a section that will 1568 * be discarded and warns about it. 1569 **/ 1570 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1571 { 1572 int i; 1573 Elf_Shdr *sechdrs = elf->sechdrs; 1574 1575 /* Walk through all sections */ 1576 for (i = 0; i < elf->num_sections; i++) { 1577 check_section(mod->name, elf, &elf->sechdrs[i]); 1578 /* We want to process only relocation sections and not .init */ 1579 if (sechdrs[i].sh_type == SHT_RELA) 1580 section_rela(mod, elf, &elf->sechdrs[i]); 1581 else if (sechdrs[i].sh_type == SHT_REL) 1582 section_rel(mod, elf, &elf->sechdrs[i]); 1583 } 1584 } 1585 1586 static char *remove_dot(char *s) 1587 { 1588 size_t n = strcspn(s, "."); 1589 1590 if (n && s[n]) { 1591 size_t m = strspn(s + n + 1, "0123456789"); 1592 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1593 s[n] = 0; 1594 } 1595 return s; 1596 } 1597 1598 /* 1599 * The CRCs are recorded in .*.cmd files in the form of: 1600 * #SYMVER <name> <crc> 1601 */ 1602 static void extract_crcs_for_object(const char *object, struct module *mod) 1603 { 1604 char cmd_file[PATH_MAX]; 1605 char *buf, *p; 1606 const char *base; 1607 int dirlen, ret; 1608 1609 base = strrchr(object, '/'); 1610 if (base) { 1611 base++; 1612 dirlen = base - object; 1613 } else { 1614 dirlen = 0; 1615 base = object; 1616 } 1617 1618 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1619 dirlen, object, base); 1620 if (ret >= sizeof(cmd_file)) { 1621 error("%s: too long path was truncated\n", cmd_file); 1622 return; 1623 } 1624 1625 buf = read_text_file(cmd_file); 1626 p = buf; 1627 1628 while ((p = strstr(p, "\n#SYMVER "))) { 1629 char *name; 1630 size_t namelen; 1631 unsigned int crc; 1632 struct symbol *sym; 1633 1634 name = p + strlen("\n#SYMVER "); 1635 1636 p = strchr(name, ' '); 1637 if (!p) 1638 break; 1639 1640 namelen = p - name; 1641 p++; 1642 1643 if (!isdigit(*p)) 1644 continue; /* skip this line */ 1645 1646 crc = strtoul(p, &p, 0); 1647 if (*p != '\n') 1648 continue; /* skip this line */ 1649 1650 name[namelen] = '\0'; 1651 1652 /* 1653 * sym_find_with_module() may return NULL here. 1654 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1655 * Since commit e1327a127703, genksyms calculates CRCs of all 1656 * symbols, including trimmed ones. Ignore orphan CRCs. 1657 */ 1658 sym = sym_find_with_module(name, mod); 1659 if (sym) 1660 sym_set_crc(sym, crc); 1661 } 1662 1663 free(buf); 1664 } 1665 1666 /* 1667 * The symbol versions (CRC) are recorded in the .*.cmd files. 1668 * Parse them to retrieve CRCs for the current module. 1669 */ 1670 static void mod_set_crcs(struct module *mod) 1671 { 1672 char objlist[PATH_MAX]; 1673 char *buf, *p, *obj; 1674 int ret; 1675 1676 if (mod->is_vmlinux) { 1677 strcpy(objlist, ".vmlinux.objs"); 1678 } else { 1679 /* objects for a module are listed in the *.mod file. */ 1680 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1681 if (ret >= sizeof(objlist)) { 1682 error("%s: too long path was truncated\n", objlist); 1683 return; 1684 } 1685 } 1686 1687 buf = read_text_file(objlist); 1688 p = buf; 1689 1690 while ((obj = strsep(&p, "\n")) && obj[0]) 1691 extract_crcs_for_object(obj, mod); 1692 1693 free(buf); 1694 } 1695 1696 static void read_symbols(const char *modname) 1697 { 1698 const char *symname; 1699 char *version; 1700 char *license; 1701 char *namespace; 1702 struct module *mod; 1703 struct elf_info info = { }; 1704 Elf_Sym *sym; 1705 1706 if (!parse_elf(&info, modname)) 1707 return; 1708 1709 if (!strends(modname, ".o")) { 1710 error("%s: filename must be suffixed with .o\n", modname); 1711 return; 1712 } 1713 1714 /* strip trailing .o */ 1715 mod = new_module(modname, strlen(modname) - strlen(".o")); 1716 1717 if (!mod->is_vmlinux) { 1718 license = get_modinfo(&info, "license"); 1719 if (!license) 1720 error("missing MODULE_LICENSE() in %s\n", modname); 1721 while (license) { 1722 if (!license_is_gpl_compatible(license)) { 1723 mod->is_gpl_compatible = false; 1724 break; 1725 } 1726 license = get_next_modinfo(&info, "license", license); 1727 } 1728 1729 namespace = get_modinfo(&info, "import_ns"); 1730 while (namespace) { 1731 add_namespace(&mod->imported_namespaces, namespace); 1732 namespace = get_next_modinfo(&info, "import_ns", 1733 namespace); 1734 } 1735 } 1736 1737 if (extra_warn && !get_modinfo(&info, "description")) 1738 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1739 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1740 symname = remove_dot(info.strtab + sym->st_name); 1741 1742 handle_symbol(mod, &info, sym, symname); 1743 handle_moddevtable(mod, &info, sym, symname); 1744 } 1745 1746 check_sec_ref(mod, &info); 1747 1748 if (!mod->is_vmlinux) { 1749 version = get_modinfo(&info, "version"); 1750 if (version || all_versions) 1751 get_src_version(mod->name, mod->srcversion, 1752 sizeof(mod->srcversion) - 1); 1753 } 1754 1755 parse_elf_finish(&info); 1756 1757 if (modversions) { 1758 /* 1759 * Our trick to get versioning for module struct etc. - it's 1760 * never passed as an argument to an exported function, so 1761 * the automatic versioning doesn't pick it up, but it's really 1762 * important anyhow. 1763 */ 1764 sym_add_unresolved("module_layout", mod, false); 1765 1766 mod_set_crcs(mod); 1767 } 1768 } 1769 1770 static void read_symbols_from_files(const char *filename) 1771 { 1772 FILE *in = stdin; 1773 char fname[PATH_MAX]; 1774 1775 in = fopen(filename, "r"); 1776 if (!in) 1777 fatal("Can't open filenames file %s: %m", filename); 1778 1779 while (fgets(fname, PATH_MAX, in) != NULL) { 1780 if (strends(fname, "\n")) 1781 fname[strlen(fname)-1] = '\0'; 1782 read_symbols(fname); 1783 } 1784 1785 fclose(in); 1786 } 1787 1788 #define SZ 500 1789 1790 /* We first write the generated file into memory using the 1791 * following helper, then compare to the file on disk and 1792 * only update the later if anything changed */ 1793 1794 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1795 const char *fmt, ...) 1796 { 1797 char tmp[SZ]; 1798 int len; 1799 va_list ap; 1800 1801 va_start(ap, fmt); 1802 len = vsnprintf(tmp, SZ, fmt, ap); 1803 buf_write(buf, tmp, len); 1804 va_end(ap); 1805 } 1806 1807 void buf_write(struct buffer *buf, const char *s, int len) 1808 { 1809 if (buf->size - buf->pos < len) { 1810 buf->size += len + SZ; 1811 buf->p = NOFAIL(realloc(buf->p, buf->size)); 1812 } 1813 strncpy(buf->p + buf->pos, s, len); 1814 buf->pos += len; 1815 } 1816 1817 static void check_exports(struct module *mod) 1818 { 1819 struct symbol *s, *exp; 1820 1821 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1822 const char *basename; 1823 exp = find_symbol(s->name); 1824 if (!exp) { 1825 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1826 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, 1827 "\"%s\" [%s.ko] undefined!\n", 1828 s->name, mod->name); 1829 continue; 1830 } 1831 if (exp->module == mod) { 1832 error("\"%s\" [%s.ko] was exported without definition\n", 1833 s->name, mod->name); 1834 continue; 1835 } 1836 1837 exp->used = true; 1838 s->module = exp->module; 1839 s->crc_valid = exp->crc_valid; 1840 s->crc = exp->crc; 1841 1842 basename = strrchr(mod->name, '/'); 1843 if (basename) 1844 basename++; 1845 else 1846 basename = mod->name; 1847 1848 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1849 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, 1850 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1851 basename, exp->name, exp->namespace); 1852 add_namespace(&mod->missing_namespaces, exp->namespace); 1853 } 1854 1855 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1856 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1857 basename, exp->name); 1858 } 1859 } 1860 1861 static void handle_white_list_exports(const char *white_list) 1862 { 1863 char *buf, *p, *name; 1864 1865 buf = read_text_file(white_list); 1866 p = buf; 1867 1868 while ((name = strsep(&p, "\n"))) { 1869 struct symbol *sym = find_symbol(name); 1870 1871 if (sym) 1872 sym->used = true; 1873 } 1874 1875 free(buf); 1876 } 1877 1878 static void check_modname_len(struct module *mod) 1879 { 1880 const char *mod_name; 1881 1882 mod_name = strrchr(mod->name, '/'); 1883 if (mod_name == NULL) 1884 mod_name = mod->name; 1885 else 1886 mod_name++; 1887 if (strlen(mod_name) >= MODULE_NAME_LEN) 1888 error("module name is too long [%s.ko]\n", mod->name); 1889 } 1890 1891 /** 1892 * Header for the generated file 1893 **/ 1894 static void add_header(struct buffer *b, struct module *mod) 1895 { 1896 buf_printf(b, "#include <linux/module.h>\n"); 1897 /* 1898 * Include build-salt.h after module.h in order to 1899 * inherit the definitions. 1900 */ 1901 buf_printf(b, "#define INCLUDE_VERMAGIC\n"); 1902 buf_printf(b, "#include <linux/build-salt.h>\n"); 1903 buf_printf(b, "#include <linux/elfnote-lto.h>\n"); 1904 buf_printf(b, "#include <linux/export-internal.h>\n"); 1905 buf_printf(b, "#include <linux/vermagic.h>\n"); 1906 buf_printf(b, "#include <linux/compiler.h>\n"); 1907 buf_printf(b, "\n"); 1908 buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n"); 1909 buf_printf(b, "#include <asm/orc_header.h>\n"); 1910 buf_printf(b, "ORC_HEADER;\n"); 1911 buf_printf(b, "#endif\n"); 1912 buf_printf(b, "\n"); 1913 buf_printf(b, "BUILD_SALT;\n"); 1914 buf_printf(b, "BUILD_LTO_INFO;\n"); 1915 buf_printf(b, "\n"); 1916 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1917 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1918 buf_printf(b, "\n"); 1919 buf_printf(b, "__visible struct module __this_module\n"); 1920 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1921 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1922 if (mod->has_init) 1923 buf_printf(b, "\t.init = init_module,\n"); 1924 if (mod->has_cleanup) 1925 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1926 "\t.exit = cleanup_module,\n" 1927 "#endif\n"); 1928 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1929 buf_printf(b, "};\n"); 1930 1931 if (!external_module) 1932 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1933 1934 buf_printf(b, 1935 "\n" 1936 "#ifdef CONFIG_RETPOLINE\n" 1937 "MODULE_INFO(retpoline, \"Y\");\n" 1938 "#endif\n"); 1939 1940 if (strstarts(mod->name, "drivers/staging")) 1941 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1942 1943 if (strstarts(mod->name, "tools/testing")) 1944 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1945 } 1946 1947 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1948 { 1949 struct symbol *sym; 1950 1951 /* generate struct for exported symbols */ 1952 buf_printf(buf, "\n"); 1953 list_for_each_entry(sym, &mod->exported_symbols, list) { 1954 if (trim_unused_exports && !sym->used) 1955 continue; 1956 1957 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1958 sym->is_func ? "FUNC" : "DATA", sym->name, 1959 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1960 } 1961 1962 if (!modversions) 1963 return; 1964 1965 /* record CRCs for exported symbols */ 1966 buf_printf(buf, "\n"); 1967 list_for_each_entry(sym, &mod->exported_symbols, list) { 1968 if (trim_unused_exports && !sym->used) 1969 continue; 1970 1971 if (!sym->crc_valid) 1972 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1973 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1974 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1975 sym->name); 1976 1977 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1978 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1979 } 1980 } 1981 1982 /** 1983 * Record CRCs for unresolved symbols 1984 **/ 1985 static void add_versions(struct buffer *b, struct module *mod) 1986 { 1987 struct symbol *s; 1988 1989 if (!modversions) 1990 return; 1991 1992 buf_printf(b, "\n"); 1993 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1994 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1995 1996 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1997 if (!s->module) 1998 continue; 1999 if (!s->crc_valid) { 2000 warn("\"%s\" [%s.ko] has no CRC!\n", 2001 s->name, mod->name); 2002 continue; 2003 } 2004 if (strlen(s->name) >= MODULE_NAME_LEN) { 2005 error("too long symbol \"%s\" [%s.ko]\n", 2006 s->name, mod->name); 2007 break; 2008 } 2009 buf_printf(b, "\t{ %#8x, \"%s\" },\n", 2010 s->crc, s->name); 2011 } 2012 2013 buf_printf(b, "};\n"); 2014 } 2015 2016 static void add_depends(struct buffer *b, struct module *mod) 2017 { 2018 struct symbol *s; 2019 int first = 1; 2020 2021 /* Clear ->seen flag of modules that own symbols needed by this. */ 2022 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2023 if (s->module) 2024 s->module->seen = s->module->is_vmlinux; 2025 } 2026 2027 buf_printf(b, "\n"); 2028 buf_printf(b, "MODULE_INFO(depends, \""); 2029 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2030 const char *p; 2031 if (!s->module) 2032 continue; 2033 2034 if (s->module->seen) 2035 continue; 2036 2037 s->module->seen = true; 2038 p = strrchr(s->module->name, '/'); 2039 if (p) 2040 p++; 2041 else 2042 p = s->module->name; 2043 buf_printf(b, "%s%s", first ? "" : ",", p); 2044 first = 0; 2045 } 2046 buf_printf(b, "\");\n"); 2047 } 2048 2049 static void add_srcversion(struct buffer *b, struct module *mod) 2050 { 2051 if (mod->srcversion[0]) { 2052 buf_printf(b, "\n"); 2053 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 2054 mod->srcversion); 2055 } 2056 } 2057 2058 static void write_buf(struct buffer *b, const char *fname) 2059 { 2060 FILE *file; 2061 2062 if (error_occurred) 2063 return; 2064 2065 file = fopen(fname, "w"); 2066 if (!file) { 2067 perror(fname); 2068 exit(1); 2069 } 2070 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2071 perror(fname); 2072 exit(1); 2073 } 2074 if (fclose(file) != 0) { 2075 perror(fname); 2076 exit(1); 2077 } 2078 } 2079 2080 static void write_if_changed(struct buffer *b, const char *fname) 2081 { 2082 char *tmp; 2083 FILE *file; 2084 struct stat st; 2085 2086 file = fopen(fname, "r"); 2087 if (!file) 2088 goto write; 2089 2090 if (fstat(fileno(file), &st) < 0) 2091 goto close_write; 2092 2093 if (st.st_size != b->pos) 2094 goto close_write; 2095 2096 tmp = NOFAIL(malloc(b->pos)); 2097 if (fread(tmp, 1, b->pos, file) != b->pos) 2098 goto free_write; 2099 2100 if (memcmp(tmp, b->p, b->pos) != 0) 2101 goto free_write; 2102 2103 free(tmp); 2104 fclose(file); 2105 return; 2106 2107 free_write: 2108 free(tmp); 2109 close_write: 2110 fclose(file); 2111 write: 2112 write_buf(b, fname); 2113 } 2114 2115 static void write_vmlinux_export_c_file(struct module *mod) 2116 { 2117 struct buffer buf = { }; 2118 2119 buf_printf(&buf, 2120 "#include <linux/export-internal.h>\n"); 2121 2122 add_exported_symbols(&buf, mod); 2123 write_if_changed(&buf, ".vmlinux.export.c"); 2124 free(buf.p); 2125 } 2126 2127 /* do sanity checks, and generate *.mod.c file */ 2128 static void write_mod_c_file(struct module *mod) 2129 { 2130 struct buffer buf = { }; 2131 char fname[PATH_MAX]; 2132 int ret; 2133 2134 add_header(&buf, mod); 2135 add_exported_symbols(&buf, mod); 2136 add_versions(&buf, mod); 2137 add_depends(&buf, mod); 2138 add_moddevtable(&buf, mod); 2139 add_srcversion(&buf, mod); 2140 2141 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2142 if (ret >= sizeof(fname)) { 2143 error("%s: too long path was truncated\n", fname); 2144 goto free; 2145 } 2146 2147 write_if_changed(&buf, fname); 2148 2149 free: 2150 free(buf.p); 2151 } 2152 2153 /* parse Module.symvers file. line format: 2154 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2155 **/ 2156 static void read_dump(const char *fname) 2157 { 2158 char *buf, *pos, *line; 2159 2160 buf = read_text_file(fname); 2161 if (!buf) 2162 /* No symbol versions, silently ignore */ 2163 return; 2164 2165 pos = buf; 2166 2167 while ((line = get_line(&pos))) { 2168 char *symname, *namespace, *modname, *d, *export; 2169 unsigned int crc; 2170 struct module *mod; 2171 struct symbol *s; 2172 bool gpl_only; 2173 2174 if (!(symname = strchr(line, '\t'))) 2175 goto fail; 2176 *symname++ = '\0'; 2177 if (!(modname = strchr(symname, '\t'))) 2178 goto fail; 2179 *modname++ = '\0'; 2180 if (!(export = strchr(modname, '\t'))) 2181 goto fail; 2182 *export++ = '\0'; 2183 if (!(namespace = strchr(export, '\t'))) 2184 goto fail; 2185 *namespace++ = '\0'; 2186 2187 crc = strtoul(line, &d, 16); 2188 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2189 goto fail; 2190 2191 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2192 gpl_only = true; 2193 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2194 gpl_only = false; 2195 } else { 2196 error("%s: unknown license %s. skip", symname, export); 2197 continue; 2198 } 2199 2200 mod = find_module(modname); 2201 if (!mod) { 2202 mod = new_module(modname, strlen(modname)); 2203 mod->from_dump = true; 2204 } 2205 s = sym_add_exported(symname, mod, gpl_only, namespace); 2206 sym_set_crc(s, crc); 2207 } 2208 free(buf); 2209 return; 2210 fail: 2211 free(buf); 2212 fatal("parse error in symbol dump file\n"); 2213 } 2214 2215 static void write_dump(const char *fname) 2216 { 2217 struct buffer buf = { }; 2218 struct module *mod; 2219 struct symbol *sym; 2220 2221 list_for_each_entry(mod, &modules, list) { 2222 if (mod->from_dump) 2223 continue; 2224 list_for_each_entry(sym, &mod->exported_symbols, list) { 2225 if (trim_unused_exports && !sym->used) 2226 continue; 2227 2228 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2229 sym->crc, sym->name, mod->name, 2230 sym->is_gpl_only ? "_GPL" : "", 2231 sym->namespace); 2232 } 2233 } 2234 write_buf(&buf, fname); 2235 free(buf.p); 2236 } 2237 2238 static void write_namespace_deps_files(const char *fname) 2239 { 2240 struct module *mod; 2241 struct namespace_list *ns; 2242 struct buffer ns_deps_buf = {}; 2243 2244 list_for_each_entry(mod, &modules, list) { 2245 2246 if (mod->from_dump || list_empty(&mod->missing_namespaces)) 2247 continue; 2248 2249 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2250 2251 list_for_each_entry(ns, &mod->missing_namespaces, list) 2252 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2253 2254 buf_printf(&ns_deps_buf, "\n"); 2255 } 2256 2257 write_if_changed(&ns_deps_buf, fname); 2258 free(ns_deps_buf.p); 2259 } 2260 2261 struct dump_list { 2262 struct list_head list; 2263 const char *file; 2264 }; 2265 2266 int main(int argc, char **argv) 2267 { 2268 struct module *mod; 2269 char *missing_namespace_deps = NULL; 2270 char *unused_exports_white_list = NULL; 2271 char *dump_write = NULL, *files_source = NULL; 2272 int opt; 2273 LIST_HEAD(dump_lists); 2274 struct dump_list *dl, *dl2; 2275 2276 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) { 2277 switch (opt) { 2278 case 'e': 2279 external_module = true; 2280 break; 2281 case 'i': 2282 dl = NOFAIL(malloc(sizeof(*dl))); 2283 dl->file = optarg; 2284 list_add_tail(&dl->list, &dump_lists); 2285 break; 2286 case 'M': 2287 module_enabled = true; 2288 break; 2289 case 'm': 2290 modversions = true; 2291 break; 2292 case 'n': 2293 ignore_missing_files = true; 2294 break; 2295 case 'o': 2296 dump_write = optarg; 2297 break; 2298 case 'a': 2299 all_versions = true; 2300 break; 2301 case 'T': 2302 files_source = optarg; 2303 break; 2304 case 't': 2305 trim_unused_exports = true; 2306 break; 2307 case 'u': 2308 unused_exports_white_list = optarg; 2309 break; 2310 case 'W': 2311 extra_warn = true; 2312 break; 2313 case 'w': 2314 warn_unresolved = true; 2315 break; 2316 case 'E': 2317 sec_mismatch_warn_only = false; 2318 break; 2319 case 'N': 2320 allow_missing_ns_imports = true; 2321 break; 2322 case 'd': 2323 missing_namespace_deps = optarg; 2324 break; 2325 default: 2326 exit(1); 2327 } 2328 } 2329 2330 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2331 read_dump(dl->file); 2332 list_del(&dl->list); 2333 free(dl); 2334 } 2335 2336 while (optind < argc) 2337 read_symbols(argv[optind++]); 2338 2339 if (files_source) 2340 read_symbols_from_files(files_source); 2341 2342 list_for_each_entry(mod, &modules, list) { 2343 if (mod->from_dump || mod->is_vmlinux) 2344 continue; 2345 2346 check_modname_len(mod); 2347 check_exports(mod); 2348 } 2349 2350 if (unused_exports_white_list) 2351 handle_white_list_exports(unused_exports_white_list); 2352 2353 list_for_each_entry(mod, &modules, list) { 2354 if (mod->from_dump) 2355 continue; 2356 2357 if (mod->is_vmlinux) 2358 write_vmlinux_export_c_file(mod); 2359 else 2360 write_mod_c_file(mod); 2361 } 2362 2363 if (missing_namespace_deps) 2364 write_namespace_deps_files(missing_namespace_deps); 2365 2366 if (dump_write) 2367 write_dump(dump_write); 2368 if (sec_mismatch_count && !sec_mismatch_warn_only) 2369 error("Section mismatches detected.\n" 2370 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2371 2372 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2373 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2374 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2375 2376 return error_occurred ? 1 : 0; 2377 } 2378