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 24 #include <hash.h> 25 #include <hashtable.h> 26 #include <list.h> 27 #include <xalloc.h> 28 #include "modpost.h" 29 #include "../../include/linux/license.h" 30 31 #define MODULE_NS_PREFIX "module:" 32 33 static bool module_enabled; 34 /* Are we using CONFIG_MODVERSIONS? */ 35 static bool modversions; 36 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 37 static bool all_versions; 38 /* Is CONFIG_BASIC_MODVERSIONS set? */ 39 static bool basic_modversions; 40 /* Is CONFIG_EXTENDED_MODVERSIONS set? */ 41 static bool extended_modversions; 42 /* If we are modposting external module set to 1 */ 43 static bool external_module; 44 /* Only warn about unresolved symbols */ 45 static bool warn_unresolved; 46 47 static int sec_mismatch_count; 48 static bool sec_mismatch_warn_only = true; 49 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */ 50 static bool trim_unused_exports; 51 52 /* ignore missing files */ 53 static bool ignore_missing_files; 54 /* If set to 1, only warn (instead of error) about missing ns imports */ 55 static bool allow_missing_ns_imports; 56 57 static bool error_occurred; 58 59 static bool extra_warn; 60 61 bool target_is_big_endian; 62 bool host_is_big_endian; 63 64 /* 65 * Cut off the warnings when there are too many. This typically occurs when 66 * vmlinux is missing. ('make modules' without building vmlinux.) 67 */ 68 #define MAX_UNRESOLVED_REPORTS 10 69 static unsigned int nr_unresolved; 70 71 /* In kernel, this size is defined in linux/module.h; 72 * here we use Elf_Addr instead of long for covering cross-compile 73 */ 74 75 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) 76 77 void modpost_log(bool is_error, const char *fmt, ...) 78 { 79 va_list arglist; 80 81 if (is_error) { 82 fprintf(stderr, "ERROR: "); 83 error_occurred = true; 84 } else { 85 fprintf(stderr, "WARNING: "); 86 } 87 88 fprintf(stderr, "modpost: "); 89 90 va_start(arglist, fmt); 91 vfprintf(stderr, fmt, arglist); 92 va_end(arglist); 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 /** 104 * get_basename - return the last part of a pathname. 105 * 106 * @path: path to extract the filename from. 107 */ 108 const char *get_basename(const char *path) 109 { 110 const char *tail = strrchr(path, '/'); 111 112 return tail ? tail + 1 : path; 113 } 114 115 char *read_text_file(const char *filename) 116 { 117 struct stat st; 118 size_t nbytes; 119 int fd; 120 char *buf; 121 122 fd = open(filename, O_RDONLY); 123 if (fd < 0) { 124 perror(filename); 125 exit(1); 126 } 127 128 if (fstat(fd, &st) < 0) { 129 perror(filename); 130 exit(1); 131 } 132 133 buf = xmalloc(st.st_size + 1); 134 135 nbytes = st.st_size; 136 137 while (nbytes) { 138 ssize_t bytes_read; 139 140 bytes_read = read(fd, buf, nbytes); 141 if (bytes_read < 0) { 142 perror(filename); 143 exit(1); 144 } 145 146 nbytes -= bytes_read; 147 } 148 buf[st.st_size] = '\0'; 149 150 close(fd); 151 152 return buf; 153 } 154 155 char *get_line(char **stringp) 156 { 157 char *orig = *stringp, *next; 158 159 /* do not return the unwanted extra line at EOF */ 160 if (!orig || *orig == '\0') 161 return NULL; 162 163 /* don't use strsep here, it is not available everywhere */ 164 next = strchr(orig, '\n'); 165 if (next) 166 *next++ = '\0'; 167 168 *stringp = next; 169 170 return orig; 171 } 172 173 /* A list of all modules we processed */ 174 LIST_HEAD(modules); 175 176 static struct module *find_module(const char *filename, const char *modname) 177 { 178 struct module *mod; 179 180 list_for_each_entry(mod, &modules, list) { 181 if (!strcmp(mod->dump_file, filename) && 182 !strcmp(mod->name, modname)) 183 return mod; 184 } 185 return NULL; 186 } 187 188 static struct module *new_module(const char *name, size_t namelen) 189 { 190 struct module *mod; 191 192 mod = xmalloc(sizeof(*mod) + namelen + 1); 193 memset(mod, 0, sizeof(*mod)); 194 195 INIT_LIST_HEAD(&mod->exported_symbols); 196 INIT_LIST_HEAD(&mod->unresolved_symbols); 197 INIT_LIST_HEAD(&mod->missing_namespaces); 198 INIT_LIST_HEAD(&mod->imported_namespaces); 199 INIT_LIST_HEAD(&mod->aliases); 200 201 memcpy(mod->name, name, namelen); 202 mod->name[namelen] = '\0'; 203 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0); 204 205 /* 206 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE() 207 * is missing, do not check the use for EXPORT_SYMBOL_GPL() because 208 * modpost will exit with an error anyway. 209 */ 210 mod->is_gpl_compatible = true; 211 212 list_add_tail(&mod->list, &modules); 213 214 return mod; 215 } 216 217 struct symbol { 218 struct hlist_node hnode;/* link to hash table */ 219 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */ 220 struct module *module; 221 char *namespace; 222 unsigned int crc; 223 bool crc_valid; 224 bool weak; 225 bool is_func; 226 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ 227 bool used; /* there exists a user of this symbol */ 228 char name[]; 229 }; 230 231 static HASHTABLE_DEFINE(symbol_hashtable, 1U << 10); 232 233 /** 234 * Allocate a new symbols for use in the hash of exported symbols or 235 * the list of unresolved symbols per module 236 **/ 237 static struct symbol *alloc_symbol(const char *name) 238 { 239 struct symbol *s = xmalloc(sizeof(*s) + strlen(name) + 1); 240 241 memset(s, 0, sizeof(*s)); 242 strcpy(s->name, name); 243 244 return s; 245 } 246 247 /* For the hash of exported symbols */ 248 static void hash_add_symbol(struct symbol *sym) 249 { 250 hash_add(symbol_hashtable, &sym->hnode, hash_str(sym->name)); 251 } 252 253 static void sym_add_unresolved(const char *name, struct module *mod, bool weak) 254 { 255 struct symbol *sym; 256 257 sym = alloc_symbol(name); 258 sym->weak = weak; 259 260 list_add_tail(&sym->list, &mod->unresolved_symbols); 261 } 262 263 static struct symbol *sym_find_with_module(const char *name, struct module *mod) 264 { 265 struct symbol *s; 266 267 /* For our purposes, .foo matches foo. PPC64 needs this. */ 268 if (name[0] == '.') 269 name++; 270 271 hash_for_each_possible(symbol_hashtable, s, hnode, hash_str(name)) { 272 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) 273 return s; 274 } 275 return NULL; 276 } 277 278 static struct symbol *find_symbol(const char *name) 279 { 280 return sym_find_with_module(name, NULL); 281 } 282 283 struct namespace_list { 284 struct list_head list; 285 char namespace[]; 286 }; 287 288 static bool contains_namespace(struct list_head *head, const char *namespace) 289 { 290 struct namespace_list *list; 291 292 /* 293 * The default namespace is null string "", which is always implicitly 294 * contained. 295 */ 296 if (!namespace[0]) 297 return true; 298 299 list_for_each_entry(list, head, list) { 300 if (!strcmp(list->namespace, namespace)) 301 return true; 302 } 303 304 return false; 305 } 306 307 static void add_namespace(struct list_head *head, const char *namespace) 308 { 309 struct namespace_list *ns_entry; 310 311 if (!contains_namespace(head, namespace)) { 312 ns_entry = xmalloc(sizeof(*ns_entry) + strlen(namespace) + 1); 313 strcpy(ns_entry->namespace, namespace); 314 list_add_tail(&ns_entry->list, head); 315 } 316 } 317 318 static void *sym_get_data_by_offset(const struct elf_info *info, 319 unsigned int secindex, unsigned long offset) 320 { 321 Elf_Shdr *sechdr = &info->sechdrs[secindex]; 322 323 return (void *)info->hdr + sechdr->sh_offset + offset; 324 } 325 326 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) 327 { 328 return sym_get_data_by_offset(info, get_secindex(info, sym), 329 sym->st_value); 330 } 331 332 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) 333 { 334 return sym_get_data_by_offset(info, info->secindex_strings, 335 sechdr->sh_name); 336 } 337 338 static const char *sec_name(const struct elf_info *info, unsigned int secindex) 339 { 340 /* 341 * If sym->st_shndx is a special section index, there is no 342 * corresponding section header. 343 * Return "" if the index is out of range of info->sechdrs[] array. 344 */ 345 if (secindex >= info->num_sections) 346 return ""; 347 348 return sech_name(info, &info->sechdrs[secindex]); 349 } 350 351 static struct symbol *sym_add_exported(const char *name, struct module *mod, 352 bool gpl_only, const char *namespace) 353 { 354 struct symbol *s = find_symbol(name); 355 356 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { 357 error("%s: '%s' exported twice. Previous export was in %s%s\n", 358 mod->name, name, s->module->name, 359 s->module->is_vmlinux ? "" : ".ko"); 360 } 361 362 s = alloc_symbol(name); 363 s->module = mod; 364 s->is_gpl_only = gpl_only; 365 s->namespace = xstrdup(namespace); 366 list_add_tail(&s->list, &mod->exported_symbols); 367 hash_add_symbol(s); 368 369 return s; 370 } 371 372 static void sym_set_crc(struct symbol *sym, unsigned int crc) 373 { 374 sym->crc = crc; 375 sym->crc_valid = true; 376 } 377 378 static void *grab_file(const char *filename, size_t *size) 379 { 380 struct stat st; 381 void *map = MAP_FAILED; 382 int fd; 383 384 fd = open(filename, O_RDONLY); 385 if (fd < 0) 386 return NULL; 387 if (fstat(fd, &st)) 388 goto failed; 389 390 *size = st.st_size; 391 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 392 393 failed: 394 close(fd); 395 if (map == MAP_FAILED) 396 return NULL; 397 return map; 398 } 399 400 static void release_file(void *file, size_t size) 401 { 402 munmap(file, size); 403 } 404 405 static int parse_elf(struct elf_info *info, const char *filename) 406 { 407 unsigned int i; 408 Elf_Ehdr *hdr; 409 Elf_Shdr *sechdrs; 410 Elf_Sym *sym; 411 const char *secstrings; 412 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 413 414 hdr = grab_file(filename, &info->size); 415 if (!hdr) { 416 if (ignore_missing_files) { 417 fprintf(stderr, "%s: %s (ignored)\n", filename, 418 strerror(errno)); 419 return 0; 420 } 421 perror(filename); 422 exit(1); 423 } 424 info->hdr = hdr; 425 if (info->size < sizeof(*hdr)) { 426 /* file too small, assume this is an empty .o file */ 427 return 0; 428 } 429 /* Is this a valid ELF file? */ 430 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 431 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 432 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 433 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 434 /* Not an ELF file - silently ignore it */ 435 return 0; 436 } 437 438 switch (hdr->e_ident[EI_DATA]) { 439 case ELFDATA2LSB: 440 target_is_big_endian = false; 441 break; 442 case ELFDATA2MSB: 443 target_is_big_endian = true; 444 break; 445 default: 446 fatal("target endian is unknown\n"); 447 } 448 449 /* Fix endianness in ELF header */ 450 hdr->e_type = TO_NATIVE(hdr->e_type); 451 hdr->e_machine = TO_NATIVE(hdr->e_machine); 452 hdr->e_version = TO_NATIVE(hdr->e_version); 453 hdr->e_entry = TO_NATIVE(hdr->e_entry); 454 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 455 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 456 hdr->e_flags = TO_NATIVE(hdr->e_flags); 457 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 458 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 459 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 460 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 461 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 462 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 463 sechdrs = (void *)hdr + hdr->e_shoff; 464 info->sechdrs = sechdrs; 465 466 /* modpost only works for relocatable objects */ 467 if (hdr->e_type != ET_REL) 468 fatal("%s: not relocatable object.", filename); 469 470 /* Check if file offset is correct */ 471 if (hdr->e_shoff > info->size) 472 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", 473 (unsigned long)hdr->e_shoff, filename, info->size); 474 475 if (hdr->e_shnum == SHN_UNDEF) { 476 /* 477 * There are more than 64k sections, 478 * read count from .sh_size. 479 */ 480 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 481 } 482 else { 483 info->num_sections = hdr->e_shnum; 484 } 485 if (hdr->e_shstrndx == SHN_XINDEX) { 486 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 487 } 488 else { 489 info->secindex_strings = hdr->e_shstrndx; 490 } 491 492 /* Fix endianness in section headers */ 493 for (i = 0; i < info->num_sections; i++) { 494 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 495 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 496 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 497 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 498 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 499 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 500 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 501 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 502 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 503 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 504 } 505 /* Find symbol table. */ 506 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 507 for (i = 1; i < info->num_sections; i++) { 508 const char *secname; 509 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 510 511 if (!nobits && sechdrs[i].sh_offset > info->size) 512 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n", 513 filename, (unsigned long)sechdrs[i].sh_offset, 514 sizeof(*hdr)); 515 516 secname = secstrings + sechdrs[i].sh_name; 517 if (strcmp(secname, ".modinfo") == 0) { 518 if (nobits) 519 fatal("%s has NOBITS .modinfo\n", filename); 520 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 521 info->modinfo_len = sechdrs[i].sh_size; 522 } else if (!strcmp(secname, ".export_symbol")) { 523 info->export_symbol_secndx = i; 524 } else if (!strcmp(secname, ".no_trim_symbol")) { 525 info->no_trim_symbol = (void *)hdr + sechdrs[i].sh_offset; 526 info->no_trim_symbol_len = sechdrs[i].sh_size; 527 } 528 529 if (sechdrs[i].sh_type == SHT_SYMTAB) { 530 unsigned int sh_link_idx; 531 symtab_idx = i; 532 info->symtab_start = (void *)hdr + 533 sechdrs[i].sh_offset; 534 info->symtab_stop = (void *)hdr + 535 sechdrs[i].sh_offset + sechdrs[i].sh_size; 536 sh_link_idx = sechdrs[i].sh_link; 537 info->strtab = (void *)hdr + 538 sechdrs[sh_link_idx].sh_offset; 539 } 540 541 /* 32bit section no. table? ("more than 64k sections") */ 542 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 543 symtab_shndx_idx = i; 544 info->symtab_shndx_start = (void *)hdr + 545 sechdrs[i].sh_offset; 546 info->symtab_shndx_stop = (void *)hdr + 547 sechdrs[i].sh_offset + sechdrs[i].sh_size; 548 } 549 } 550 if (!info->symtab_start) 551 fatal("%s has no symtab?\n", filename); 552 553 /* Fix endianness in symbols */ 554 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 555 sym->st_shndx = TO_NATIVE(sym->st_shndx); 556 sym->st_name = TO_NATIVE(sym->st_name); 557 sym->st_value = TO_NATIVE(sym->st_value); 558 sym->st_size = TO_NATIVE(sym->st_size); 559 } 560 561 if (symtab_shndx_idx != ~0U) { 562 Elf32_Word *p; 563 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 564 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 565 filename, sechdrs[symtab_shndx_idx].sh_link, 566 symtab_idx); 567 /* Fix endianness */ 568 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 569 p++) 570 *p = TO_NATIVE(*p); 571 } 572 573 symsearch_init(info); 574 575 return 1; 576 } 577 578 static void parse_elf_finish(struct elf_info *info) 579 { 580 symsearch_finish(info); 581 release_file(info->hdr, info->size); 582 } 583 584 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 585 { 586 /* ignore __this_module, it will be resolved shortly */ 587 if (strcmp(symname, "__this_module") == 0) 588 return 1; 589 /* ignore global offset table */ 590 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 591 return 1; 592 if (info->hdr->e_machine == EM_PPC) 593 /* Special register function linked on all modules during final link of .ko */ 594 if (strstarts(symname, "_restgpr_") || 595 strstarts(symname, "_savegpr_") || 596 strstarts(symname, "_rest32gpr_") || 597 strstarts(symname, "_save32gpr_") || 598 strstarts(symname, "_restvr_") || 599 strstarts(symname, "_savevr_")) 600 return 1; 601 if (info->hdr->e_machine == EM_PPC64) 602 /* Special register function linked on all modules during final link of .ko */ 603 if (strstarts(symname, "_restgpr0_") || 604 strstarts(symname, "_savegpr0_") || 605 strstarts(symname, "_restgpr1_") || 606 strstarts(symname, "_savegpr1_") || 607 strstarts(symname, "_restfpr_") || 608 strstarts(symname, "_savefpr_") || 609 strstarts(symname, "_restvr_") || 610 strstarts(symname, "_savevr_") || 611 strcmp(symname, ".TOC.") == 0) 612 return 1; 613 614 /* ignore linker-created section bounds variables */ 615 if (strstarts(symname, "__start_") || strstarts(symname, "__stop_")) 616 return 1; 617 618 /* 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 = xstrdup(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 return sym ? elf->strtab + sym->st_name : ""; 714 } 715 716 /* 717 * Check whether the 'string' argument matches one of the 'patterns', 718 * an array of shell wildcard patterns (glob). 719 * 720 * Return true is there is a match. 721 */ 722 static bool match(const char *string, const char *const patterns[]) 723 { 724 const char *pattern; 725 726 while ((pattern = *patterns++)) { 727 if (!fnmatch(pattern, string, 0)) 728 return true; 729 } 730 731 return false; 732 } 733 734 /* useful to pass patterns to match() directly */ 735 #define PATTERNS(...) \ 736 ({ \ 737 static const char *const patterns[] = {__VA_ARGS__, NULL}; \ 738 patterns; \ 739 }) 740 741 /* sections that we do not want to do full section mismatch check on */ 742 static const char *const section_white_list[] = 743 { 744 ".comment*", 745 ".debug*", 746 ".zdebug*", /* Compressed debug sections. */ 747 ".GCC.command.line", /* record-gcc-switches */ 748 ".mdebug*", /* alpha, score, mips etc. */ 749 ".pdr", /* alpha, score, mips etc. */ 750 ".stab*", 751 ".note*", 752 ".got*", 753 ".toc*", 754 ".xt.prop", /* xtensa */ 755 ".xt.lit", /* xtensa */ 756 ".arcextmap*", /* arc */ 757 ".gnu.linkonce.arcext*", /* arc : modules */ 758 ".cmem*", /* EZchip */ 759 ".fmt_slot*", /* EZchip */ 760 ".gnu.lto*", 761 ".discard.*", 762 ".llvm.call-graph-profile", /* call graph */ 763 NULL 764 }; 765 766 /* 767 * This is used to find sections missing the SHF_ALLOC flag. 768 * The cause of this is often a section specified in assembler 769 * without "ax" / "aw". 770 */ 771 static void check_section(const char *modname, struct elf_info *elf, 772 Elf_Shdr *sechdr) 773 { 774 const char *sec = sech_name(elf, sechdr); 775 776 if (sechdr->sh_type == SHT_PROGBITS && 777 !(sechdr->sh_flags & SHF_ALLOC) && 778 !match(sec, section_white_list)) { 779 warn("%s (%s): unexpected non-allocatable section.\n" 780 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 781 "Note that for example <linux/init.h> contains\n" 782 "section definitions for use in .S files.\n\n", 783 modname, sec); 784 } 785 } 786 787 788 789 #define ALL_INIT_DATA_SECTIONS \ 790 ".init.setup", ".init.rodata", ".init.data" 791 792 #define ALL_PCI_INIT_SECTIONS \ 793 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 794 ".pci_fixup_enable", ".pci_fixup_resume", \ 795 ".pci_fixup_resume_early", ".pci_fixup_suspend" 796 797 #define ALL_INIT_SECTIONS ".init.*" 798 #define ALL_EXIT_SECTIONS ".exit.*" 799 800 #define DATA_SECTIONS ".data", ".data.rel" 801 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ 802 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \ 803 ".ltext", ".ltext.*" 804 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ 805 ".fixup", ".entry.text", ".exception.text", \ 806 ".coldtext", ".softirqentry.text", ".irqentry.text" 807 808 #define ALL_TEXT_SECTIONS ".init.text", ".exit.text", \ 809 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 810 811 enum mismatch { 812 TEXTDATA_TO_ANY_INIT_EXIT, 813 XXXINIT_TO_SOME_INIT, 814 ANY_INIT_TO_ANY_EXIT, 815 ANY_EXIT_TO_ANY_INIT, 816 EXTABLE_TO_NON_TEXT, 817 }; 818 819 /** 820 * Describe how to match sections on different criteria: 821 * 822 * @fromsec: Array of sections to be matched. 823 * 824 * @bad_tosec: Relocations applied to a section in @fromsec to a section in 825 * this array is forbidden (black-list). Can be empty. 826 * 827 * @good_tosec: Relocations applied to a section in @fromsec must be 828 * targeting sections in this array (white-list). Can be empty. 829 * 830 * @mismatch: Type of mismatch. 831 */ 832 struct sectioncheck { 833 const char *fromsec[20]; 834 const char *bad_tosec[20]; 835 const char *good_tosec[20]; 836 enum mismatch mismatch; 837 }; 838 839 static const struct sectioncheck sectioncheck[] = { 840 /* Do not reference init/exit code/data from 841 * normal code and data 842 */ 843 { 844 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 845 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }, 846 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT, 847 }, 848 /* Do not use exit code/data from init code */ 849 { 850 .fromsec = { ALL_INIT_SECTIONS, NULL }, 851 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 852 .mismatch = ANY_INIT_TO_ANY_EXIT, 853 }, 854 /* Do not use init code/data from exit code */ 855 { 856 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 857 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 858 .mismatch = ANY_EXIT_TO_ANY_INIT, 859 }, 860 { 861 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 862 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 863 .mismatch = ANY_INIT_TO_ANY_EXIT, 864 }, 865 { 866 .fromsec = { "__ex_table", NULL }, 867 /* If you're adding any new black-listed sections in here, consider 868 * adding a special 'printer' for them in scripts/check_extable. 869 */ 870 .bad_tosec = { ".altinstr_replacement", NULL }, 871 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 872 .mismatch = EXTABLE_TO_NON_TEXT, 873 } 874 }; 875 876 static const struct sectioncheck *section_mismatch( 877 const char *fromsec, const char *tosec) 878 { 879 int i; 880 881 /* 882 * The target section could be the SHT_NUL section when we're 883 * handling relocations to un-resolved symbols, trying to match it 884 * doesn't make much sense and causes build failures on parisc 885 * architectures. 886 */ 887 if (*tosec == '\0') 888 return NULL; 889 890 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 891 const struct sectioncheck *check = §ioncheck[i]; 892 893 if (match(fromsec, check->fromsec)) { 894 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 895 return check; 896 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 897 return check; 898 } 899 } 900 return NULL; 901 } 902 903 /** 904 * Whitelist to allow certain references to pass with no warning. 905 * 906 * Pattern 1: 907 * If a module parameter is declared __initdata and permissions=0 908 * then this is legal despite the warning generated. 909 * We cannot see value of permissions here, so just ignore 910 * this pattern. 911 * The pattern is identified by: 912 * tosec = .init.data 913 * fromsec = .data* 914 * atsym =__param* 915 * 916 * Pattern 1a: 917 * module_param_call() ops can refer to __init set function if permissions=0 918 * The pattern is identified by: 919 * tosec = .init.text 920 * fromsec = .data* 921 * atsym = __param_ops_* 922 * 923 * Pattern 3: 924 * Whitelist all references from .head.text to any init section 925 * 926 * Pattern 4: 927 * Some symbols belong to init section but still it is ok to reference 928 * these from non-init sections as these symbols don't have any memory 929 * allocated for them and symbol address and value are same. So even 930 * if init section is freed, its ok to reference those symbols. 931 * For ex. symbols marking the init section boundaries. 932 * This pattern is identified by 933 * refsymname = __init_begin, _sinittext, _einittext 934 * 935 * Pattern 5: 936 * GCC may optimize static inlines when fed constant arg(s) resulting 937 * in functions like cpumask_empty() -- generating an associated symbol 938 * cpumask_empty.constprop.3 that appears in the audit. If the const that 939 * is passed in comes from __init, like say nmi_ipi_mask, we get a 940 * meaningless section warning. May need to add isra symbols too... 941 * This pattern is identified by 942 * tosec = init section 943 * fromsec = text section 944 * refsymname = *.constprop.* 945 * 946 **/ 947 static int secref_whitelist(const char *fromsec, const char *fromsym, 948 const char *tosec, const char *tosym) 949 { 950 /* Check for pattern 1 */ 951 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 952 match(fromsec, PATTERNS(DATA_SECTIONS)) && 953 strstarts(fromsym, "__param")) 954 return 0; 955 956 /* Check for pattern 1a */ 957 if (strcmp(tosec, ".init.text") == 0 && 958 match(fromsec, PATTERNS(DATA_SECTIONS)) && 959 strstarts(fromsym, "__param_ops_")) 960 return 0; 961 962 /* symbols in data sections that may refer to any init/exit sections */ 963 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 964 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 965 match(fromsym, PATTERNS("*_ops", "*_console"))) 966 return 0; 967 968 /* Check for pattern 3 */ 969 if (strstarts(fromsec, ".head.text") && 970 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 971 return 0; 972 973 /* Check for pattern 4 */ 974 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 975 return 0; 976 977 /* Check for pattern 5 */ 978 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 979 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 980 match(fromsym, PATTERNS("*.constprop.*"))) 981 return 0; 982 983 return 1; 984 } 985 986 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 987 unsigned int secndx) 988 { 989 return symsearch_find_nearest(elf, addr, secndx, false, ~0); 990 } 991 992 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 993 { 994 Elf_Sym *new_sym; 995 996 /* If the supplied symbol has a valid name, return it */ 997 if (is_valid_name(elf, sym)) 998 return sym; 999 1000 /* 1001 * Strive to find a better symbol name, but the resulting name may not 1002 * match the symbol referenced in the original code. 1003 */ 1004 new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym), 1005 true, 20); 1006 return new_sym ? new_sym : sym; 1007 } 1008 1009 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1010 { 1011 if (secndx >= elf->num_sections) 1012 return false; 1013 1014 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1015 } 1016 1017 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1018 const struct sectioncheck* const mismatch, 1019 Elf_Sym *tsym, 1020 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1021 const char *tosec, Elf_Addr taddr) 1022 { 1023 Elf_Sym *from; 1024 const char *tosym; 1025 const char *fromsym; 1026 char taddr_str[16]; 1027 1028 from = find_fromsym(elf, faddr, fsecndx); 1029 fromsym = sym_name(elf, from); 1030 1031 tsym = find_tosym(elf, taddr, tsym); 1032 tosym = sym_name(elf, tsym); 1033 1034 /* check whitelist - we may ignore it */ 1035 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1036 return; 1037 1038 sec_mismatch_count++; 1039 1040 if (!tosym[0]) 1041 snprintf(taddr_str, sizeof(taddr_str), "0x%x", (unsigned int)taddr); 1042 1043 /* 1044 * The format for the reference source: <symbol_name>+<offset> or <address> 1045 * The format for the reference destination: <symbol_name> or <address> 1046 */ 1047 warn("%s: section mismatch in reference: %s%s0x%x (section: %s) -> %s (section: %s)\n", 1048 modname, fromsym, fromsym[0] ? "+" : "", 1049 (unsigned int)(faddr - (fromsym[0] ? from->st_value : 0)), 1050 fromsec, tosym[0] ? tosym : taddr_str, tosec); 1051 1052 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1053 if (match(tosec, mismatch->bad_tosec)) 1054 fatal("The relocation at %s+0x%lx references\n" 1055 "section \"%s\" which is black-listed.\n" 1056 "Something is seriously wrong and should be fixed.\n" 1057 "You might get more information about where this is\n" 1058 "coming from by using scripts/check_extable.sh %s\n", 1059 fromsec, (long)faddr, tosec, modname); 1060 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1061 warn("The relocation at %s+0x%lx references\n" 1062 "section \"%s\" which is not in the list of\n" 1063 "authorized sections. If you're adding a new section\n" 1064 "and/or if this reference is valid, add \"%s\" to the\n" 1065 "list of authorized sections to jump to on fault.\n" 1066 "This can be achieved by adding \"%s\" to\n" 1067 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1068 fromsec, (long)faddr, tosec, tosec, tosec); 1069 else 1070 error("%s+0x%lx references non-executable section '%s'\n", 1071 fromsec, (long)faddr, tosec); 1072 } 1073 } 1074 1075 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1076 Elf_Addr faddr, const char *secname, 1077 Elf_Sym *sym) 1078 { 1079 static const char *prefix = "__export_symbol_"; 1080 const char *label_name, *name, *data; 1081 Elf_Sym *label; 1082 struct symbol *s; 1083 bool is_gpl; 1084 1085 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1086 label_name = sym_name(elf, label); 1087 1088 if (!strstarts(label_name, prefix)) { 1089 error("%s: .export_symbol section contains strange symbol '%s'\n", 1090 mod->name, label_name); 1091 return; 1092 } 1093 1094 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1095 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1096 error("%s: local symbol '%s' was exported\n", mod->name, 1097 label_name + strlen(prefix)); 1098 return; 1099 } 1100 1101 name = sym_name(elf, sym); 1102 if (strcmp(label_name + strlen(prefix), name)) { 1103 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1104 mod->name, name); 1105 return; 1106 } 1107 1108 data = sym_get_data(elf, label); /* license */ 1109 if (!strcmp(data, "GPL")) { 1110 is_gpl = true; 1111 } else if (!strcmp(data, "")) { 1112 is_gpl = false; 1113 } else { 1114 error("%s: unknown license '%s' was specified for '%s'\n", 1115 mod->name, data, name); 1116 return; 1117 } 1118 1119 data += strlen(data) + 1; /* namespace */ 1120 s = sym_add_exported(name, mod, is_gpl, data); 1121 1122 /* 1123 * We need to be aware whether we are exporting a function or 1124 * a data on some architectures. 1125 */ 1126 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1127 1128 /* 1129 * For parisc64, symbols prefixed $$ from the library have the symbol type 1130 * STT_LOPROC. They should be handled as functions too. 1131 */ 1132 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1133 elf->hdr->e_machine == EM_PARISC && 1134 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1135 s->is_func = true; 1136 1137 if (match(secname, PATTERNS(ALL_INIT_SECTIONS))) 1138 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1139 mod->name, name); 1140 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS))) 1141 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1142 mod->name, name); 1143 } 1144 1145 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1146 Elf_Sym *sym, 1147 unsigned int fsecndx, const char *fromsec, 1148 Elf_Addr faddr, Elf_Addr taddr) 1149 { 1150 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1151 const struct sectioncheck *mismatch; 1152 1153 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1154 check_export_symbol(mod, elf, faddr, tosec, sym); 1155 return; 1156 } 1157 1158 mismatch = section_mismatch(fromsec, tosec); 1159 if (!mismatch) 1160 return; 1161 1162 default_mismatch_handler(mod->name, elf, mismatch, sym, 1163 fsecndx, fromsec, faddr, 1164 tosec, taddr); 1165 } 1166 1167 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1168 { 1169 switch (r_type) { 1170 case R_386_32: 1171 return get_unaligned_native(location); 1172 case R_386_PC32: 1173 return get_unaligned_native(location) + 4; 1174 } 1175 1176 return (Elf_Addr)(-1); 1177 } 1178 1179 static int32_t sign_extend32(int32_t value, int index) 1180 { 1181 uint8_t shift = 31 - index; 1182 1183 return (int32_t)(value << shift) >> shift; 1184 } 1185 1186 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1187 { 1188 uint32_t inst, upper, lower, sign, j1, j2; 1189 int32_t offset; 1190 1191 switch (r_type) { 1192 case R_ARM_ABS32: 1193 case R_ARM_REL32: 1194 inst = get_unaligned_native((uint32_t *)loc); 1195 return inst + sym->st_value; 1196 case R_ARM_MOVW_ABS_NC: 1197 case R_ARM_MOVT_ABS: 1198 inst = get_unaligned_native((uint32_t *)loc); 1199 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1200 15); 1201 return offset + sym->st_value; 1202 case R_ARM_PC24: 1203 case R_ARM_CALL: 1204 case R_ARM_JUMP24: 1205 inst = get_unaligned_native((uint32_t *)loc); 1206 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1207 return offset + sym->st_value + 8; 1208 case R_ARM_THM_MOVW_ABS_NC: 1209 case R_ARM_THM_MOVT_ABS: 1210 upper = get_unaligned_native((uint16_t *)loc); 1211 lower = get_unaligned_native((uint16_t *)loc + 1); 1212 offset = sign_extend32(((upper & 0x000f) << 12) | 1213 ((upper & 0x0400) << 1) | 1214 ((lower & 0x7000) >> 4) | 1215 (lower & 0x00ff), 1216 15); 1217 return offset + sym->st_value; 1218 case R_ARM_THM_JUMP19: 1219 /* 1220 * Encoding T3: 1221 * S = upper[10] 1222 * imm6 = upper[5:0] 1223 * J1 = lower[13] 1224 * J2 = lower[11] 1225 * imm11 = lower[10:0] 1226 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1227 */ 1228 upper = get_unaligned_native((uint16_t *)loc); 1229 lower = get_unaligned_native((uint16_t *)loc + 1); 1230 1231 sign = (upper >> 10) & 1; 1232 j1 = (lower >> 13) & 1; 1233 j2 = (lower >> 11) & 1; 1234 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1235 ((upper & 0x03f) << 12) | 1236 ((lower & 0x07ff) << 1), 1237 20); 1238 return offset + sym->st_value + 4; 1239 case R_ARM_THM_PC22: 1240 case R_ARM_THM_JUMP24: 1241 /* 1242 * Encoding T4: 1243 * S = upper[10] 1244 * imm10 = upper[9:0] 1245 * J1 = lower[13] 1246 * J2 = lower[11] 1247 * imm11 = lower[10:0] 1248 * I1 = NOT(J1 XOR S) 1249 * I2 = NOT(J2 XOR S) 1250 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1251 */ 1252 upper = get_unaligned_native((uint16_t *)loc); 1253 lower = get_unaligned_native((uint16_t *)loc + 1); 1254 1255 sign = (upper >> 10) & 1; 1256 j1 = (lower >> 13) & 1; 1257 j2 = (lower >> 11) & 1; 1258 offset = sign_extend32((sign << 24) | 1259 ((~(j1 ^ sign) & 1) << 23) | 1260 ((~(j2 ^ sign) & 1) << 22) | 1261 ((upper & 0x03ff) << 12) | 1262 ((lower & 0x07ff) << 1), 1263 24); 1264 return offset + sym->st_value + 4; 1265 } 1266 1267 return (Elf_Addr)(-1); 1268 } 1269 1270 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1271 { 1272 uint32_t inst; 1273 1274 inst = get_unaligned_native(location); 1275 switch (r_type) { 1276 case R_MIPS_LO16: 1277 return inst & 0xffff; 1278 case R_MIPS_26: 1279 return (inst & 0x03ffffff) << 2; 1280 case R_MIPS_32: 1281 return inst; 1282 } 1283 return (Elf_Addr)(-1); 1284 } 1285 1286 #ifndef EM_RISCV 1287 #define EM_RISCV 243 1288 #endif 1289 1290 #ifndef R_RISCV_SUB32 1291 #define R_RISCV_SUB32 39 1292 #endif 1293 1294 #ifndef EM_LOONGARCH 1295 #define EM_LOONGARCH 258 1296 #endif 1297 1298 #ifndef R_LARCH_SUB32 1299 #define R_LARCH_SUB32 55 1300 #endif 1301 1302 #ifndef R_LARCH_RELAX 1303 #define R_LARCH_RELAX 100 1304 #endif 1305 1306 #ifndef R_LARCH_ALIGN 1307 #define R_LARCH_ALIGN 102 1308 #endif 1309 1310 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1311 unsigned int *r_type, unsigned int *r_sym) 1312 { 1313 typedef struct { 1314 Elf64_Word r_sym; /* Symbol index */ 1315 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1316 unsigned char r_type3; /* 3rd relocation type */ 1317 unsigned char r_type2; /* 2nd relocation type */ 1318 unsigned char r_type; /* 1st relocation type */ 1319 } Elf64_Mips_R_Info; 1320 1321 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1322 1323 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1324 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1325 1326 *r_type = mips64_r_info->r_type; 1327 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1328 return; 1329 } 1330 1331 if (is_64bit) 1332 r_info = TO_NATIVE((Elf64_Xword)r_info); 1333 else 1334 r_info = TO_NATIVE((Elf32_Word)r_info); 1335 1336 *r_type = ELF_R_TYPE(r_info); 1337 *r_sym = ELF_R_SYM(r_info); 1338 } 1339 1340 static void section_rela(struct module *mod, struct elf_info *elf, 1341 unsigned int fsecndx, const char *fromsec, 1342 const Elf_Rela *start, const Elf_Rela *stop) 1343 { 1344 const Elf_Rela *rela; 1345 1346 for (rela = start; rela < stop; rela++) { 1347 Elf_Sym *tsym; 1348 Elf_Addr taddr, r_offset; 1349 unsigned int r_type, r_sym; 1350 1351 r_offset = TO_NATIVE(rela->r_offset); 1352 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1353 1354 tsym = elf->symtab_start + r_sym; 1355 taddr = tsym->st_value + TO_NATIVE(rela->r_addend); 1356 1357 switch (elf->hdr->e_machine) { 1358 case EM_RISCV: 1359 if (!strcmp("__ex_table", fromsec) && 1360 r_type == R_RISCV_SUB32) 1361 continue; 1362 break; 1363 case EM_LOONGARCH: 1364 switch (r_type) { 1365 case R_LARCH_SUB32: 1366 if (!strcmp("__ex_table", fromsec)) 1367 continue; 1368 break; 1369 case R_LARCH_RELAX: 1370 case R_LARCH_ALIGN: 1371 /* These relocs do not refer to symbols */ 1372 continue; 1373 } 1374 break; 1375 } 1376 1377 check_section_mismatch(mod, elf, tsym, 1378 fsecndx, fromsec, r_offset, taddr); 1379 } 1380 } 1381 1382 static void section_rel(struct module *mod, struct elf_info *elf, 1383 unsigned int fsecndx, const char *fromsec, 1384 const Elf_Rel *start, const Elf_Rel *stop) 1385 { 1386 const Elf_Rel *rel; 1387 1388 for (rel = start; rel < stop; rel++) { 1389 Elf_Sym *tsym; 1390 Elf_Addr taddr, r_offset; 1391 unsigned int r_type, r_sym; 1392 void *loc; 1393 1394 r_offset = TO_NATIVE(rel->r_offset); 1395 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1396 1397 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1398 tsym = elf->symtab_start + r_sym; 1399 1400 switch (elf->hdr->e_machine) { 1401 case EM_386: 1402 taddr = addend_386_rel(loc, r_type); 1403 break; 1404 case EM_ARM: 1405 taddr = addend_arm_rel(loc, tsym, r_type); 1406 break; 1407 case EM_MIPS: 1408 taddr = addend_mips_rel(loc, r_type); 1409 break; 1410 default: 1411 fatal("Please add code to calculate addend for this architecture\n"); 1412 } 1413 1414 check_section_mismatch(mod, elf, tsym, 1415 fsecndx, fromsec, r_offset, taddr); 1416 } 1417 } 1418 1419 /** 1420 * A module includes a number of sections that are discarded 1421 * either when loaded or when used as built-in. 1422 * For loaded modules all functions marked __init and all data 1423 * marked __initdata will be discarded when the module has been initialized. 1424 * Likewise for modules used built-in the sections marked __exit 1425 * are discarded because __exit marked function are supposed to be called 1426 * only when a module is unloaded which never happens for built-in modules. 1427 * The check_sec_ref() function traverses all relocation records 1428 * to find all references to a section that reference a section that will 1429 * be discarded and warns about it. 1430 **/ 1431 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1432 { 1433 int i; 1434 1435 /* Walk through all sections */ 1436 for (i = 0; i < elf->num_sections; i++) { 1437 Elf_Shdr *sechdr = &elf->sechdrs[i]; 1438 1439 check_section(mod->name, elf, sechdr); 1440 /* We want to process only relocation sections and not .init */ 1441 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) { 1442 /* section to which the relocation applies */ 1443 unsigned int secndx = sechdr->sh_info; 1444 const char *secname = sec_name(elf, secndx); 1445 const void *start, *stop; 1446 1447 /* If the section is known good, skip it */ 1448 if (match(secname, section_white_list)) 1449 continue; 1450 1451 start = sym_get_data_by_offset(elf, i, 0); 1452 stop = start + sechdr->sh_size; 1453 1454 if (sechdr->sh_type == SHT_RELA) 1455 section_rela(mod, elf, secndx, secname, 1456 start, stop); 1457 else 1458 section_rel(mod, elf, secndx, secname, 1459 start, stop); 1460 } 1461 } 1462 } 1463 1464 static char *remove_dot(char *s) 1465 { 1466 size_t n = strcspn(s, "."); 1467 1468 if (n && s[n]) { 1469 size_t m = strspn(s + n + 1, "0123456789"); 1470 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1471 s[n] = 0; 1472 } 1473 return s; 1474 } 1475 1476 /* 1477 * The CRCs are recorded in .*.cmd files in the form of: 1478 * #SYMVER <name> <crc> 1479 */ 1480 static void extract_crcs_for_object(const char *object, struct module *mod) 1481 { 1482 char cmd_file[PATH_MAX]; 1483 char *buf, *p; 1484 const char *base; 1485 int dirlen, ret; 1486 1487 base = get_basename(object); 1488 dirlen = base - object; 1489 1490 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1491 dirlen, object, base); 1492 if (ret >= sizeof(cmd_file)) { 1493 error("%s: too long path was truncated\n", cmd_file); 1494 return; 1495 } 1496 1497 buf = read_text_file(cmd_file); 1498 p = buf; 1499 1500 while ((p = strstr(p, "\n#SYMVER "))) { 1501 char *name; 1502 size_t namelen; 1503 unsigned int crc; 1504 struct symbol *sym; 1505 1506 name = p + strlen("\n#SYMVER "); 1507 1508 p = strchr(name, ' '); 1509 if (!p) 1510 break; 1511 1512 namelen = p - name; 1513 p++; 1514 1515 if (!isdigit(*p)) 1516 continue; /* skip this line */ 1517 1518 crc = strtoul(p, &p, 0); 1519 if (*p != '\n') 1520 continue; /* skip this line */ 1521 1522 name[namelen] = '\0'; 1523 1524 /* 1525 * sym_find_with_module() may return NULL here. 1526 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1527 * Since commit e1327a127703, genksyms calculates CRCs of all 1528 * symbols, including trimmed ones. Ignore orphan CRCs. 1529 */ 1530 sym = sym_find_with_module(name, mod); 1531 if (sym) 1532 sym_set_crc(sym, crc); 1533 } 1534 1535 free(buf); 1536 } 1537 1538 /* 1539 * The symbol versions (CRC) are recorded in the .*.cmd files. 1540 * Parse them to retrieve CRCs for the current module. 1541 */ 1542 static void mod_set_crcs(struct module *mod) 1543 { 1544 char objlist[PATH_MAX]; 1545 char *buf, *p, *obj; 1546 int ret; 1547 1548 if (mod->is_vmlinux) { 1549 strcpy(objlist, ".vmlinux.objs"); 1550 } else { 1551 /* objects for a module are listed in the *.mod file. */ 1552 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1553 if (ret >= sizeof(objlist)) { 1554 error("%s: too long path was truncated\n", objlist); 1555 return; 1556 } 1557 } 1558 1559 buf = read_text_file(objlist); 1560 p = buf; 1561 1562 while ((obj = strsep(&p, "\n")) && obj[0]) 1563 extract_crcs_for_object(obj, mod); 1564 1565 free(buf); 1566 } 1567 1568 static void read_symbols(const char *modname) 1569 { 1570 const char *symname; 1571 char *version; 1572 char *license; 1573 char *namespace; 1574 struct module *mod; 1575 struct elf_info info = { }; 1576 Elf_Sym *sym; 1577 1578 if (!parse_elf(&info, modname)) 1579 return; 1580 1581 if (!strends(modname, ".o")) { 1582 error("%s: filename must be suffixed with .o\n", modname); 1583 return; 1584 } 1585 1586 /* strip trailing .o */ 1587 mod = new_module(modname, strlen(modname) - strlen(".o")); 1588 1589 /* save .no_trim_symbol section for later use */ 1590 if (info.no_trim_symbol_len) { 1591 mod->no_trim_symbol = xmalloc(info.no_trim_symbol_len); 1592 memcpy(mod->no_trim_symbol, info.no_trim_symbol, 1593 info.no_trim_symbol_len); 1594 mod->no_trim_symbol_len = info.no_trim_symbol_len; 1595 } 1596 1597 if (!mod->is_vmlinux) { 1598 license = get_modinfo(&info, "license"); 1599 if (!license) 1600 error("missing MODULE_LICENSE() in %s\n", modname); 1601 while (license) { 1602 if (!license_is_gpl_compatible(license)) { 1603 mod->is_gpl_compatible = false; 1604 break; 1605 } 1606 license = get_next_modinfo(&info, "license", license); 1607 } 1608 1609 for (namespace = get_modinfo(&info, "import_ns"); 1610 namespace; 1611 namespace = get_next_modinfo(&info, "import_ns", namespace)) { 1612 if (strstarts(namespace, MODULE_NS_PREFIX)) 1613 error("%s: explicitly importing namespace \"%s\" is not allowed.\n", 1614 mod->name, namespace); 1615 1616 add_namespace(&mod->imported_namespaces, namespace); 1617 } 1618 1619 if (!get_modinfo(&info, "description")) 1620 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1621 } 1622 1623 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1624 symname = remove_dot(info.strtab + sym->st_name); 1625 1626 handle_symbol(mod, &info, sym, symname); 1627 handle_moddevtable(mod, &info, sym, symname); 1628 } 1629 1630 check_sec_ref(mod, &info); 1631 1632 if (!mod->is_vmlinux) { 1633 version = get_modinfo(&info, "version"); 1634 if (version || all_versions) 1635 get_src_version(mod->name, mod->srcversion, 1636 sizeof(mod->srcversion) - 1); 1637 } 1638 1639 parse_elf_finish(&info); 1640 1641 if (modversions) { 1642 /* 1643 * Our trick to get versioning for module struct etc. - it's 1644 * never passed as an argument to an exported function, so 1645 * the automatic versioning doesn't pick it up, but it's really 1646 * important anyhow. 1647 */ 1648 sym_add_unresolved("module_layout", mod, false); 1649 1650 mod_set_crcs(mod); 1651 } 1652 } 1653 1654 static void read_symbols_from_files(const char *filename) 1655 { 1656 FILE *in = stdin; 1657 char fname[PATH_MAX]; 1658 1659 in = fopen(filename, "r"); 1660 if (!in) 1661 fatal("Can't open filenames file %s: %m", filename); 1662 1663 while (fgets(fname, PATH_MAX, in) != NULL) { 1664 if (strends(fname, "\n")) 1665 fname[strlen(fname)-1] = '\0'; 1666 read_symbols(fname); 1667 } 1668 1669 fclose(in); 1670 } 1671 1672 #define SZ 500 1673 1674 /* We first write the generated file into memory using the 1675 * following helper, then compare to the file on disk and 1676 * only update the later if anything changed */ 1677 1678 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1679 const char *fmt, ...) 1680 { 1681 char tmp[SZ]; 1682 int len; 1683 va_list ap; 1684 1685 va_start(ap, fmt); 1686 len = vsnprintf(tmp, SZ, fmt, ap); 1687 buf_write(buf, tmp, len); 1688 va_end(ap); 1689 } 1690 1691 void buf_write(struct buffer *buf, const char *s, int len) 1692 { 1693 if (buf->size - buf->pos < len) { 1694 buf->size += len + SZ; 1695 buf->p = xrealloc(buf->p, buf->size); 1696 } 1697 strncpy(buf->p + buf->pos, s, len); 1698 buf->pos += len; 1699 } 1700 1701 /** 1702 * verify_module_namespace() - does @modname have access to this symbol's @namespace 1703 * @namespace: export symbol namespace 1704 * @modname: module name 1705 * 1706 * If @namespace is prefixed with "module:" to indicate it is a module namespace 1707 * then test if @modname matches any of the comma separated patterns. 1708 * 1709 * The patterns only support tail-glob. 1710 */ 1711 static bool verify_module_namespace(const char *namespace, const char *modname) 1712 { 1713 size_t len, modlen = strlen(modname); 1714 const char *prefix = "module:"; 1715 const char *sep; 1716 bool glob; 1717 1718 if (!strstarts(namespace, prefix)) 1719 return false; 1720 1721 for (namespace += strlen(prefix); *namespace; namespace = sep) { 1722 sep = strchrnul(namespace, ','); 1723 len = sep - namespace; 1724 1725 glob = false; 1726 if (sep[-1] == '*') { 1727 len--; 1728 glob = true; 1729 } 1730 1731 if (*sep) 1732 sep++; 1733 1734 if (strncmp(namespace, modname, len) == 0 && (glob || len == modlen)) 1735 return true; 1736 } 1737 1738 return false; 1739 } 1740 1741 static void check_exports(struct module *mod) 1742 { 1743 struct symbol *s, *exp; 1744 1745 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1746 const char *basename; 1747 exp = find_symbol(s->name); 1748 if (!exp) { 1749 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1750 modpost_log(!warn_unresolved, 1751 "\"%s\" [%s.ko] undefined!\n", 1752 s->name, mod->name); 1753 continue; 1754 } 1755 if (exp->module == mod) { 1756 error("\"%s\" [%s.ko] was exported without definition\n", 1757 s->name, mod->name); 1758 continue; 1759 } 1760 1761 exp->used = true; 1762 s->module = exp->module; 1763 s->crc_valid = exp->crc_valid; 1764 s->crc = exp->crc; 1765 1766 basename = get_basename(mod->name); 1767 1768 if (!verify_module_namespace(exp->namespace, basename) && 1769 !contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1770 modpost_log(!allow_missing_ns_imports, 1771 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1772 basename, exp->name, exp->namespace); 1773 add_namespace(&mod->missing_namespaces, exp->namespace); 1774 } 1775 1776 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1777 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1778 basename, exp->name); 1779 } 1780 } 1781 1782 static void handle_white_list_exports(const char *white_list) 1783 { 1784 char *buf, *p, *name; 1785 1786 buf = read_text_file(white_list); 1787 p = buf; 1788 1789 while ((name = strsep(&p, "\n"))) { 1790 struct symbol *sym = find_symbol(name); 1791 1792 if (sym) 1793 sym->used = true; 1794 } 1795 1796 free(buf); 1797 } 1798 1799 /* 1800 * Keep symbols recorded in the .no_trim_symbol section. This is necessary to 1801 * prevent CONFIG_TRIM_UNUSED_KSYMS from dropping EXPORT_SYMBOL because 1802 * symbol_get() relies on the symbol being present in the ksymtab for lookups. 1803 */ 1804 static void keep_no_trim_symbols(struct module *mod) 1805 { 1806 unsigned long size = mod->no_trim_symbol_len; 1807 1808 for (char *s = mod->no_trim_symbol; s; s = next_string(s , &size)) { 1809 struct symbol *sym; 1810 1811 /* 1812 * If find_symbol() returns NULL, this symbol is not provided 1813 * by any module, and symbol_get() will fail. 1814 */ 1815 sym = find_symbol(s); 1816 if (sym) 1817 sym->used = true; 1818 } 1819 } 1820 1821 static void check_modname_len(struct module *mod) 1822 { 1823 const char *mod_name; 1824 1825 mod_name = get_basename(mod->name); 1826 1827 if (strlen(mod_name) >= MODULE_NAME_LEN) 1828 error("module name is too long [%s.ko]\n", mod->name); 1829 } 1830 1831 /** 1832 * Header for the generated file 1833 **/ 1834 static void add_header(struct buffer *b, struct module *mod) 1835 { 1836 buf_printf(b, "#include <linux/module.h>\n"); 1837 buf_printf(b, "#include <linux/export-internal.h>\n"); 1838 buf_printf(b, "#include <linux/compiler.h>\n"); 1839 buf_printf(b, "\n"); 1840 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1841 buf_printf(b, "\n"); 1842 buf_printf(b, "__visible struct module __this_module\n"); 1843 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1844 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1845 if (mod->has_init) 1846 buf_printf(b, "\t.init = init_module,\n"); 1847 if (mod->has_cleanup) 1848 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1849 "\t.exit = cleanup_module,\n" 1850 "#endif\n"); 1851 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1852 buf_printf(b, "};\n"); 1853 1854 if (!external_module) 1855 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1856 1857 if (strstarts(mod->name, "drivers/staging")) 1858 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1859 1860 if (strstarts(mod->name, "tools/testing")) 1861 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1862 } 1863 1864 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1865 { 1866 struct symbol *sym; 1867 1868 /* generate struct for exported symbols */ 1869 buf_printf(buf, "\n"); 1870 list_for_each_entry(sym, &mod->exported_symbols, list) { 1871 if (trim_unused_exports && !sym->used) 1872 continue; 1873 1874 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1875 sym->is_func ? "FUNC" : "DATA", sym->name, 1876 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1877 } 1878 1879 if (!modversions) 1880 return; 1881 1882 /* record CRCs for exported symbols */ 1883 buf_printf(buf, "\n"); 1884 list_for_each_entry(sym, &mod->exported_symbols, list) { 1885 if (trim_unused_exports && !sym->used) 1886 continue; 1887 1888 if (!sym->crc_valid) 1889 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1890 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1891 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1892 sym->name); 1893 1894 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1895 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1896 } 1897 } 1898 1899 /** 1900 * Record CRCs for unresolved symbols, supporting long names 1901 */ 1902 static void add_extended_versions(struct buffer *b, struct module *mod) 1903 { 1904 struct symbol *s; 1905 1906 if (!extended_modversions) 1907 return; 1908 1909 buf_printf(b, "\n"); 1910 buf_printf(b, "static const u32 ____version_ext_crcs[]\n"); 1911 buf_printf(b, "__used __section(\"__version_ext_crcs\") = {\n"); 1912 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1913 if (!s->module) 1914 continue; 1915 if (!s->crc_valid) { 1916 warn("\"%s\" [%s.ko] has no CRC!\n", 1917 s->name, mod->name); 1918 continue; 1919 } 1920 buf_printf(b, "\t0x%08x,\n", s->crc); 1921 } 1922 buf_printf(b, "};\n"); 1923 1924 buf_printf(b, "static const char ____version_ext_names[]\n"); 1925 buf_printf(b, "__used __section(\"__version_ext_names\") =\n"); 1926 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1927 if (!s->module) 1928 continue; 1929 if (!s->crc_valid) 1930 /* 1931 * We already warned on this when producing the crc 1932 * table. 1933 * We need to skip its name too, as the indexes in 1934 * both tables need to align. 1935 */ 1936 continue; 1937 buf_printf(b, "\t\"%s\\0\"\n", s->name); 1938 } 1939 buf_printf(b, ";\n"); 1940 } 1941 1942 /** 1943 * Record CRCs for unresolved symbols 1944 **/ 1945 static void add_versions(struct buffer *b, struct module *mod) 1946 { 1947 struct symbol *s; 1948 1949 if (!basic_modversions) 1950 return; 1951 1952 buf_printf(b, "\n"); 1953 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1954 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1955 1956 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1957 if (!s->module) 1958 continue; 1959 if (!s->crc_valid) { 1960 warn("\"%s\" [%s.ko] has no CRC!\n", 1961 s->name, mod->name); 1962 continue; 1963 } 1964 if (strlen(s->name) >= MODULE_NAME_LEN) { 1965 if (extended_modversions) { 1966 /* this symbol will only be in the extended info */ 1967 continue; 1968 } else { 1969 error("too long symbol \"%s\" [%s.ko]\n", 1970 s->name, mod->name); 1971 break; 1972 } 1973 } 1974 buf_printf(b, "\t{ 0x%08x, \"%s\" },\n", 1975 s->crc, s->name); 1976 } 1977 1978 buf_printf(b, "};\n"); 1979 } 1980 1981 static void add_depends(struct buffer *b, struct module *mod) 1982 { 1983 struct symbol *s; 1984 int first = 1; 1985 1986 /* Clear ->seen flag of modules that own symbols needed by this. */ 1987 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1988 if (s->module) 1989 s->module->seen = s->module->is_vmlinux; 1990 } 1991 1992 buf_printf(b, "\n"); 1993 buf_printf(b, "MODULE_INFO(depends, \""); 1994 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1995 const char *p; 1996 if (!s->module) 1997 continue; 1998 1999 if (s->module->seen) 2000 continue; 2001 2002 s->module->seen = true; 2003 p = get_basename(s->module->name); 2004 buf_printf(b, "%s%s", first ? "" : ",", p); 2005 first = 0; 2006 } 2007 buf_printf(b, "\");\n"); 2008 } 2009 2010 static void add_srcversion(struct buffer *b, struct module *mod) 2011 { 2012 if (mod->srcversion[0]) { 2013 buf_printf(b, "\n"); 2014 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 2015 mod->srcversion); 2016 } 2017 } 2018 2019 static void write_buf(struct buffer *b, const char *fname) 2020 { 2021 FILE *file; 2022 2023 if (error_occurred) 2024 return; 2025 2026 file = fopen(fname, "w"); 2027 if (!file) { 2028 perror(fname); 2029 exit(1); 2030 } 2031 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2032 perror(fname); 2033 exit(1); 2034 } 2035 if (fclose(file) != 0) { 2036 perror(fname); 2037 exit(1); 2038 } 2039 } 2040 2041 static void write_if_changed(struct buffer *b, const char *fname) 2042 { 2043 char *tmp; 2044 FILE *file; 2045 struct stat st; 2046 2047 file = fopen(fname, "r"); 2048 if (!file) 2049 goto write; 2050 2051 if (fstat(fileno(file), &st) < 0) 2052 goto close_write; 2053 2054 if (st.st_size != b->pos) 2055 goto close_write; 2056 2057 tmp = xmalloc(b->pos); 2058 if (fread(tmp, 1, b->pos, file) != b->pos) 2059 goto free_write; 2060 2061 if (memcmp(tmp, b->p, b->pos) != 0) 2062 goto free_write; 2063 2064 free(tmp); 2065 fclose(file); 2066 return; 2067 2068 free_write: 2069 free(tmp); 2070 close_write: 2071 fclose(file); 2072 write: 2073 write_buf(b, fname); 2074 } 2075 2076 static void write_vmlinux_export_c_file(struct module *mod) 2077 { 2078 struct buffer buf = { }; 2079 struct module_alias *alias, *next; 2080 2081 buf_printf(&buf, 2082 "#include <linux/export-internal.h>\n"); 2083 2084 add_exported_symbols(&buf, mod); 2085 2086 buf_printf(&buf, 2087 "#include <linux/module.h>\n" 2088 "#undef __MODULE_INFO_PREFIX\n" 2089 "#define __MODULE_INFO_PREFIX\n"); 2090 2091 list_for_each_entry_safe(alias, next, &mod->aliases, node) { 2092 buf_printf(&buf, "MODULE_INFO(%s.alias, \"%s\");\n", 2093 alias->builtin_modname, alias->str); 2094 list_del(&alias->node); 2095 free(alias->builtin_modname); 2096 free(alias); 2097 } 2098 2099 write_if_changed(&buf, ".vmlinux.export.c"); 2100 free(buf.p); 2101 } 2102 2103 /* do sanity checks, and generate *.mod.c file */ 2104 static void write_mod_c_file(struct module *mod) 2105 { 2106 struct buffer buf = { }; 2107 struct module_alias *alias, *next; 2108 char fname[PATH_MAX]; 2109 int ret; 2110 2111 add_header(&buf, mod); 2112 add_exported_symbols(&buf, mod); 2113 add_versions(&buf, mod); 2114 add_extended_versions(&buf, mod); 2115 add_depends(&buf, mod); 2116 2117 buf_printf(&buf, "\n"); 2118 list_for_each_entry_safe(alias, next, &mod->aliases, node) { 2119 buf_printf(&buf, "MODULE_ALIAS(\"%s\");\n", alias->str); 2120 list_del(&alias->node); 2121 free(alias); 2122 } 2123 2124 add_srcversion(&buf, mod); 2125 2126 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2127 if (ret >= sizeof(fname)) { 2128 error("%s: too long path was truncated\n", fname); 2129 goto free; 2130 } 2131 2132 write_if_changed(&buf, fname); 2133 2134 free: 2135 free(buf.p); 2136 } 2137 2138 /* parse Module.symvers file. line format: 2139 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2140 **/ 2141 static void read_dump(const char *fname) 2142 { 2143 char *buf, *pos, *line; 2144 2145 buf = read_text_file(fname); 2146 if (!buf) 2147 /* No symbol versions, silently ignore */ 2148 return; 2149 2150 pos = buf; 2151 2152 while ((line = get_line(&pos))) { 2153 char *symname, *namespace, *modname, *d, *export; 2154 unsigned int crc; 2155 struct module *mod; 2156 struct symbol *s; 2157 bool gpl_only; 2158 2159 if (!(symname = strchr(line, '\t'))) 2160 goto fail; 2161 *symname++ = '\0'; 2162 if (!(modname = strchr(symname, '\t'))) 2163 goto fail; 2164 *modname++ = '\0'; 2165 if (!(export = strchr(modname, '\t'))) 2166 goto fail; 2167 *export++ = '\0'; 2168 if (!(namespace = strchr(export, '\t'))) 2169 goto fail; 2170 *namespace++ = '\0'; 2171 2172 crc = strtoul(line, &d, 16); 2173 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2174 goto fail; 2175 2176 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2177 gpl_only = true; 2178 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2179 gpl_only = false; 2180 } else { 2181 error("%s: unknown license %s. skip", symname, export); 2182 continue; 2183 } 2184 2185 mod = find_module(fname, modname); 2186 if (!mod) { 2187 mod = new_module(modname, strlen(modname)); 2188 mod->dump_file = fname; 2189 } 2190 s = sym_add_exported(symname, mod, gpl_only, namespace); 2191 sym_set_crc(s, crc); 2192 } 2193 free(buf); 2194 return; 2195 fail: 2196 free(buf); 2197 fatal("parse error in symbol dump file\n"); 2198 } 2199 2200 static void write_dump(const char *fname) 2201 { 2202 struct buffer buf = { }; 2203 struct module *mod; 2204 struct symbol *sym; 2205 2206 list_for_each_entry(mod, &modules, list) { 2207 if (mod->dump_file) 2208 continue; 2209 list_for_each_entry(sym, &mod->exported_symbols, list) { 2210 if (trim_unused_exports && !sym->used) 2211 continue; 2212 2213 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2214 sym->crc, sym->name, mod->name, 2215 sym->is_gpl_only ? "_GPL" : "", 2216 sym->namespace); 2217 } 2218 } 2219 write_buf(&buf, fname); 2220 free(buf.p); 2221 } 2222 2223 static void write_namespace_deps_files(const char *fname) 2224 { 2225 struct module *mod; 2226 struct namespace_list *ns; 2227 struct buffer ns_deps_buf = {}; 2228 2229 list_for_each_entry(mod, &modules, list) { 2230 2231 if (mod->dump_file || list_empty(&mod->missing_namespaces)) 2232 continue; 2233 2234 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2235 2236 list_for_each_entry(ns, &mod->missing_namespaces, list) 2237 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2238 2239 buf_printf(&ns_deps_buf, "\n"); 2240 } 2241 2242 write_if_changed(&ns_deps_buf, fname); 2243 free(ns_deps_buf.p); 2244 } 2245 2246 struct dump_list { 2247 struct list_head list; 2248 const char *file; 2249 }; 2250 2251 static void check_host_endian(void) 2252 { 2253 static const union { 2254 short s; 2255 char c[2]; 2256 } endian_test = { .c = {0x01, 0x02} }; 2257 2258 switch (endian_test.s) { 2259 case 0x0102: 2260 host_is_big_endian = true; 2261 break; 2262 case 0x0201: 2263 host_is_big_endian = false; 2264 break; 2265 default: 2266 fatal("Unknown host endian\n"); 2267 } 2268 } 2269 2270 int main(int argc, char **argv) 2271 { 2272 struct module *mod; 2273 char *missing_namespace_deps = NULL; 2274 char *unused_exports_white_list = NULL; 2275 char *dump_write = NULL, *files_source = NULL; 2276 int opt; 2277 LIST_HEAD(dump_lists); 2278 struct dump_list *dl, *dl2; 2279 2280 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:xb")) != -1) { 2281 switch (opt) { 2282 case 'e': 2283 external_module = true; 2284 break; 2285 case 'i': 2286 dl = xmalloc(sizeof(*dl)); 2287 dl->file = optarg; 2288 list_add_tail(&dl->list, &dump_lists); 2289 break; 2290 case 'M': 2291 module_enabled = true; 2292 break; 2293 case 'm': 2294 modversions = true; 2295 break; 2296 case 'n': 2297 ignore_missing_files = true; 2298 break; 2299 case 'o': 2300 dump_write = optarg; 2301 break; 2302 case 'a': 2303 all_versions = true; 2304 break; 2305 case 'T': 2306 files_source = optarg; 2307 break; 2308 case 't': 2309 trim_unused_exports = true; 2310 break; 2311 case 'u': 2312 unused_exports_white_list = optarg; 2313 break; 2314 case 'W': 2315 extra_warn = true; 2316 break; 2317 case 'w': 2318 warn_unresolved = true; 2319 break; 2320 case 'E': 2321 sec_mismatch_warn_only = false; 2322 break; 2323 case 'N': 2324 allow_missing_ns_imports = true; 2325 break; 2326 case 'd': 2327 missing_namespace_deps = optarg; 2328 break; 2329 case 'b': 2330 basic_modversions = true; 2331 break; 2332 case 'x': 2333 extended_modversions = true; 2334 break; 2335 default: 2336 exit(1); 2337 } 2338 } 2339 2340 check_host_endian(); 2341 2342 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2343 read_dump(dl->file); 2344 list_del(&dl->list); 2345 free(dl); 2346 } 2347 2348 while (optind < argc) 2349 read_symbols(argv[optind++]); 2350 2351 if (files_source) 2352 read_symbols_from_files(files_source); 2353 2354 list_for_each_entry(mod, &modules, list) { 2355 keep_no_trim_symbols(mod); 2356 2357 if (mod->dump_file || mod->is_vmlinux) 2358 continue; 2359 2360 check_modname_len(mod); 2361 check_exports(mod); 2362 } 2363 2364 if (unused_exports_white_list) 2365 handle_white_list_exports(unused_exports_white_list); 2366 2367 list_for_each_entry(mod, &modules, list) { 2368 if (mod->dump_file) 2369 continue; 2370 2371 if (mod->is_vmlinux) 2372 write_vmlinux_export_c_file(mod); 2373 else 2374 write_mod_c_file(mod); 2375 } 2376 2377 if (missing_namespace_deps) 2378 write_namespace_deps_files(missing_namespace_deps); 2379 2380 if (dump_write) 2381 write_dump(dump_write); 2382 if (sec_mismatch_count && !sec_mismatch_warn_only) 2383 error("Section mismatches detected.\n" 2384 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2385 2386 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2387 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2388 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2389 2390 return error_occurred ? 1 : 0; 2391 } 2392