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