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 __attribute__((unused)); 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 static uint8_t get_symbol_flags(const struct symbol *sym) 248 { 249 return sym->is_gpl_only ? KSYM_FLAG_GPL_ONLY : 0; 250 } 251 252 /* For the hash of exported symbols */ 253 static void hash_add_symbol(struct symbol *sym) 254 { 255 hash_add(symbol_hashtable, &sym->hnode, hash_str(sym->name)); 256 } 257 258 static void sym_add_unresolved(const char *name, struct module *mod, bool weak) 259 { 260 struct symbol *sym; 261 262 sym = alloc_symbol(name); 263 sym->weak = weak; 264 265 list_add_tail(&sym->list, &mod->unresolved_symbols); 266 } 267 268 static struct symbol *sym_find_with_module(const char *name, struct module *mod) 269 { 270 struct symbol *s; 271 272 /* For our purposes, .foo matches foo. PPC64 needs this. */ 273 if (name[0] == '.') 274 name++; 275 276 hash_for_each_possible(symbol_hashtable, s, hnode, hash_str(name)) { 277 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) 278 return s; 279 } 280 return NULL; 281 } 282 283 static struct symbol *find_symbol(const char *name) 284 { 285 return sym_find_with_module(name, NULL); 286 } 287 288 struct namespace_list { 289 struct list_head list; 290 char namespace[]; 291 }; 292 293 static bool contains_namespace(struct list_head *head, const char *namespace) 294 { 295 struct namespace_list *list; 296 297 /* 298 * The default namespace is null string "", which is always implicitly 299 * contained. 300 */ 301 if (!namespace[0]) 302 return true; 303 304 list_for_each_entry(list, head, list) { 305 if (!strcmp(list->namespace, namespace)) 306 return true; 307 } 308 309 return false; 310 } 311 312 static void add_namespace(struct list_head *head, const char *namespace) 313 { 314 struct namespace_list *ns_entry; 315 316 if (!contains_namespace(head, namespace)) { 317 ns_entry = xmalloc(sizeof(*ns_entry) + strlen(namespace) + 1); 318 strcpy(ns_entry->namespace, namespace); 319 list_add_tail(&ns_entry->list, head); 320 } 321 } 322 323 static void *sym_get_data_by_offset(const struct elf_info *info, 324 unsigned int secindex, unsigned long offset) 325 { 326 Elf_Shdr *sechdr = &info->sechdrs[secindex]; 327 328 return (void *)info->hdr + sechdr->sh_offset + offset; 329 } 330 331 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) 332 { 333 return sym_get_data_by_offset(info, get_secindex(info, sym), 334 sym->st_value); 335 } 336 337 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) 338 { 339 return sym_get_data_by_offset(info, info->secindex_strings, 340 sechdr->sh_name); 341 } 342 343 static const char *sec_name(const struct elf_info *info, unsigned int secindex) 344 { 345 /* 346 * If sym->st_shndx is a special section index, there is no 347 * corresponding section header. 348 * Return "" if the index is out of range of info->sechdrs[] array. 349 */ 350 if (secindex >= info->num_sections) 351 return ""; 352 353 return sech_name(info, &info->sechdrs[secindex]); 354 } 355 356 static struct symbol *sym_add_exported(const char *name, struct module *mod, 357 bool gpl_only, const char *namespace) 358 { 359 struct symbol *s = find_symbol(name); 360 361 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { 362 error("%s: '%s' exported twice. Previous export was in %s%s\n", 363 mod->name, name, s->module->name, 364 s->module->is_vmlinux ? "" : ".ko"); 365 } 366 367 s = alloc_symbol(name); 368 s->module = mod; 369 s->is_gpl_only = gpl_only; 370 s->namespace = xstrdup(namespace); 371 list_add_tail(&s->list, &mod->exported_symbols); 372 hash_add_symbol(s); 373 374 return s; 375 } 376 377 static void sym_set_crc(struct symbol *sym, unsigned int crc) 378 { 379 sym->crc = crc; 380 sym->crc_valid = true; 381 } 382 383 static void *grab_file(const char *filename, size_t *size) 384 { 385 struct stat st; 386 void *map = MAP_FAILED; 387 int fd; 388 389 fd = open(filename, O_RDONLY); 390 if (fd < 0) 391 return NULL; 392 if (fstat(fd, &st)) 393 goto failed; 394 395 *size = st.st_size; 396 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 397 398 failed: 399 close(fd); 400 if (map == MAP_FAILED) 401 return NULL; 402 return map; 403 } 404 405 static void release_file(void *file, size_t size) 406 { 407 munmap(file, size); 408 } 409 410 static int parse_elf(struct elf_info *info, const char *filename) 411 { 412 unsigned int i; 413 Elf_Ehdr *hdr; 414 Elf_Shdr *sechdrs; 415 Elf_Sym *sym; 416 const char *secstrings; 417 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 418 419 hdr = grab_file(filename, &info->size); 420 if (!hdr) { 421 if (ignore_missing_files) { 422 fprintf(stderr, "%s: %s (ignored)\n", filename, 423 strerror(errno)); 424 return 0; 425 } 426 perror(filename); 427 exit(1); 428 } 429 info->hdr = hdr; 430 if (info->size < sizeof(*hdr)) { 431 /* file too small, assume this is an empty .o file */ 432 return 0; 433 } 434 /* Is this a valid ELF file? */ 435 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 436 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 437 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 438 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 439 /* Not an ELF file - silently ignore it */ 440 return 0; 441 } 442 443 switch (hdr->e_ident[EI_DATA]) { 444 case ELFDATA2LSB: 445 target_is_big_endian = false; 446 break; 447 case ELFDATA2MSB: 448 target_is_big_endian = true; 449 break; 450 default: 451 fatal("target endian is unknown\n"); 452 } 453 454 /* Fix endianness in ELF header */ 455 hdr->e_type = TO_NATIVE(hdr->e_type); 456 hdr->e_machine = TO_NATIVE(hdr->e_machine); 457 hdr->e_version = TO_NATIVE(hdr->e_version); 458 hdr->e_entry = TO_NATIVE(hdr->e_entry); 459 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 460 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 461 hdr->e_flags = TO_NATIVE(hdr->e_flags); 462 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 463 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 464 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 465 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 466 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 467 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 468 sechdrs = (void *)hdr + hdr->e_shoff; 469 info->sechdrs = sechdrs; 470 471 /* modpost only works for relocatable objects */ 472 if (hdr->e_type != ET_REL) 473 fatal("%s: not relocatable object.", filename); 474 475 /* Check if file offset is correct */ 476 if (hdr->e_shoff > info->size) 477 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", 478 (unsigned long)hdr->e_shoff, filename, info->size); 479 480 if (hdr->e_shnum == SHN_UNDEF) { 481 /* 482 * There are more than 64k sections, 483 * read count from .sh_size. 484 */ 485 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 486 } 487 else { 488 info->num_sections = hdr->e_shnum; 489 } 490 if (hdr->e_shstrndx == SHN_XINDEX) { 491 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 492 } 493 else { 494 info->secindex_strings = hdr->e_shstrndx; 495 } 496 497 /* Fix endianness in section headers */ 498 for (i = 0; i < info->num_sections; i++) { 499 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 500 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 501 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 502 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 503 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 504 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 505 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 506 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 507 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 508 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 509 } 510 /* Find symbol table. */ 511 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 512 for (i = 1; i < info->num_sections; i++) { 513 const char *secname; 514 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 515 516 if (!nobits && sechdrs[i].sh_offset > info->size) 517 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n", 518 filename, (unsigned long)sechdrs[i].sh_offset, 519 sizeof(*hdr)); 520 521 secname = secstrings + sechdrs[i].sh_name; 522 if (strcmp(secname, ".modinfo") == 0) { 523 if (nobits) 524 fatal("%s has NOBITS .modinfo\n", filename); 525 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 526 info->modinfo_len = sechdrs[i].sh_size; 527 } else if (!strcmp(secname, ".export_symbol")) { 528 info->export_symbol_secndx = i; 529 } else if (!strcmp(secname, ".no_trim_symbol")) { 530 info->no_trim_symbol = (void *)hdr + sechdrs[i].sh_offset; 531 info->no_trim_symbol_len = sechdrs[i].sh_size; 532 } 533 534 if (sechdrs[i].sh_type == SHT_SYMTAB) { 535 unsigned int sh_link_idx; 536 symtab_idx = i; 537 info->symtab_start = (void *)hdr + 538 sechdrs[i].sh_offset; 539 info->symtab_stop = (void *)hdr + 540 sechdrs[i].sh_offset + sechdrs[i].sh_size; 541 sh_link_idx = sechdrs[i].sh_link; 542 info->strtab = (void *)hdr + 543 sechdrs[sh_link_idx].sh_offset; 544 } 545 546 /* 32bit section no. table? ("more than 64k sections") */ 547 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 548 symtab_shndx_idx = i; 549 info->symtab_shndx_start = (void *)hdr + 550 sechdrs[i].sh_offset; 551 info->symtab_shndx_stop = (void *)hdr + 552 sechdrs[i].sh_offset + sechdrs[i].sh_size; 553 } 554 } 555 if (!info->symtab_start) 556 fatal("%s has no symtab?\n", filename); 557 558 /* Fix endianness in symbols */ 559 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 560 sym->st_shndx = TO_NATIVE(sym->st_shndx); 561 sym->st_name = TO_NATIVE(sym->st_name); 562 sym->st_value = TO_NATIVE(sym->st_value); 563 sym->st_size = TO_NATIVE(sym->st_size); 564 } 565 566 if (symtab_shndx_idx != ~0U) { 567 Elf32_Word *p; 568 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 569 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 570 filename, sechdrs[symtab_shndx_idx].sh_link, 571 symtab_idx); 572 /* Fix endianness */ 573 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 574 p++) 575 *p = TO_NATIVE(*p); 576 } 577 578 symsearch_init(info); 579 580 return 1; 581 } 582 583 static void parse_elf_finish(struct elf_info *info) 584 { 585 symsearch_finish(info); 586 release_file(info->hdr, info->size); 587 } 588 589 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 590 { 591 /* ignore __this_module, it will be resolved shortly */ 592 if (strcmp(symname, "__this_module") == 0) 593 return 1; 594 /* ignore global offset table */ 595 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 596 return 1; 597 if (info->hdr->e_machine == EM_PPC) 598 /* Special register function linked on all modules during final link of .ko */ 599 if (strstarts(symname, "_restgpr_") || 600 strstarts(symname, "_savegpr_") || 601 strstarts(symname, "_rest32gpr_") || 602 strstarts(symname, "_save32gpr_") || 603 strstarts(symname, "_restvr_") || 604 strstarts(symname, "_savevr_")) 605 return 1; 606 if (info->hdr->e_machine == EM_PPC64) 607 /* Special register function linked on all modules during final link of .ko */ 608 if (strstarts(symname, "_restgpr0_") || 609 strstarts(symname, "_savegpr0_") || 610 strstarts(symname, "_restgpr1_") || 611 strstarts(symname, "_savegpr1_") || 612 strstarts(symname, "_restfpr_") || 613 strstarts(symname, "_savefpr_") || 614 strstarts(symname, "_restvr_") || 615 strstarts(symname, "_savevr_") || 616 strcmp(symname, ".TOC.") == 0) 617 return 1; 618 619 /* ignore linker-created section bounds variables */ 620 if (strstarts(symname, "__start_") || strstarts(symname, "__stop_")) 621 return 1; 622 623 /* Do not ignore this symbol */ 624 return 0; 625 } 626 627 static void handle_symbol(struct module *mod, struct elf_info *info, 628 const Elf_Sym *sym, const char *symname) 629 { 630 switch (sym->st_shndx) { 631 case SHN_COMMON: 632 if (strstarts(symname, "__gnu_lto_")) { 633 /* Should warn here, but modpost runs before the linker */ 634 } else 635 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 636 break; 637 case SHN_UNDEF: 638 /* undefined symbol */ 639 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 640 ELF_ST_BIND(sym->st_info) != STB_WEAK) 641 break; 642 if (ignore_undef_symbol(info, symname)) 643 break; 644 if (info->hdr->e_machine == EM_SPARC || 645 info->hdr->e_machine == EM_SPARCV9) { 646 /* Ignore register directives. */ 647 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 648 break; 649 if (symname[0] == '.') { 650 char *munged = xstrdup(symname); 651 munged[0] = '_'; 652 munged[1] = toupper(munged[1]); 653 symname = munged; 654 } 655 } 656 657 sym_add_unresolved(symname, mod, 658 ELF_ST_BIND(sym->st_info) == STB_WEAK); 659 break; 660 default: 661 if (strcmp(symname, "init_module") == 0) 662 mod->has_init = true; 663 if (strcmp(symname, "cleanup_module") == 0) 664 mod->has_cleanup = true; 665 break; 666 } 667 } 668 669 /** 670 * Parse tag=value strings from .modinfo section 671 **/ 672 static char *next_string(char *string, unsigned long *secsize) 673 { 674 /* Skip non-zero chars */ 675 while (string[0]) { 676 string++; 677 if ((*secsize)-- <= 1) 678 return NULL; 679 } 680 681 /* Skip any zero padding. */ 682 while (!string[0]) { 683 string++; 684 if ((*secsize)-- <= 1) 685 return NULL; 686 } 687 return string; 688 } 689 690 static char *get_next_modinfo(struct elf_info *info, const char *tag, 691 char *prev) 692 { 693 char *p; 694 unsigned int taglen = strlen(tag); 695 char *modinfo = info->modinfo; 696 unsigned long size = info->modinfo_len; 697 698 if (prev) { 699 size -= prev - modinfo; 700 modinfo = next_string(prev, &size); 701 } 702 703 for (p = modinfo; p; p = next_string(p, &size)) { 704 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 705 return p + taglen + 1; 706 } 707 return NULL; 708 } 709 710 static char *get_modinfo(struct elf_info *info, const char *tag) 711 712 { 713 return get_next_modinfo(info, tag, NULL); 714 } 715 716 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 717 { 718 return sym ? elf->strtab + sym->st_name : ""; 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 "__llvm_covfun", 769 "__llvm_covmap", 770 ".klp.symid", /* objtool --klp-symids */ 771 NULL 772 }; 773 774 /* 775 * This is used to find sections missing the SHF_ALLOC flag. 776 * The cause of this is often a section specified in assembler 777 * without "ax" / "aw". 778 */ 779 static void check_section(const char *modname, struct elf_info *elf, 780 Elf_Shdr *sechdr) 781 { 782 const char *sec = sech_name(elf, sechdr); 783 784 if (sechdr->sh_type == SHT_PROGBITS && 785 !(sechdr->sh_flags & SHF_ALLOC) && 786 !match(sec, section_white_list)) { 787 warn("%s (%s): unexpected non-allocatable section.\n" 788 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 789 "Note that for example <linux/init.h> contains\n" 790 "section definitions for use in .S files.\n\n", 791 modname, sec); 792 } 793 } 794 795 796 797 #define ALL_INIT_DATA_SECTIONS \ 798 ".init.setup", ".init.rodata", ".init.data" 799 800 #define ALL_PCI_INIT_SECTIONS \ 801 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 802 ".pci_fixup_enable", ".pci_fixup_resume", \ 803 ".pci_fixup_resume_early", ".pci_fixup_suspend" 804 805 #define ALL_INIT_SECTIONS ".init.*" 806 #define ALL_EXIT_SECTIONS ".exit.*" 807 808 #define DATA_SECTIONS ".data", ".data.rel" 809 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ 810 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \ 811 ".ltext", ".ltext.*" 812 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ 813 ".fixup", ".entry.text", ".exception.text", \ 814 ".coldtext", ".softirqentry.text", ".irqentry.text" 815 816 #define ALL_TEXT_SECTIONS ".init.text", ".exit.text", \ 817 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 818 819 enum mismatch { 820 TEXTDATA_TO_ANY_INIT_EXIT, 821 XXXINIT_TO_SOME_INIT, 822 ANY_INIT_TO_ANY_EXIT, 823 ANY_EXIT_TO_ANY_INIT, 824 EXTABLE_TO_NON_TEXT, 825 }; 826 827 /** 828 * Describe how to match sections on different criteria: 829 * 830 * @fromsec: Array of sections to be matched. 831 * 832 * @bad_tosec: Relocations applied to a section in @fromsec to a section in 833 * this array is forbidden (black-list). Can be empty. 834 * 835 * @good_tosec: Relocations applied to a section in @fromsec must be 836 * targeting sections in this array (white-list). Can be empty. 837 * 838 * @mismatch: Type of mismatch. 839 */ 840 struct sectioncheck { 841 const char *fromsec[20]; 842 const char *bad_tosec[20]; 843 const char *good_tosec[20]; 844 enum mismatch mismatch; 845 }; 846 847 static const struct sectioncheck sectioncheck[] = { 848 /* Do not reference init/exit code/data from 849 * normal code and data 850 */ 851 { 852 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 853 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }, 854 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT, 855 }, 856 /* Do not use exit code/data from init code */ 857 { 858 .fromsec = { ALL_INIT_SECTIONS, NULL }, 859 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 860 .mismatch = ANY_INIT_TO_ANY_EXIT, 861 }, 862 /* Do not use init code/data from exit code */ 863 { 864 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 865 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 866 .mismatch = ANY_EXIT_TO_ANY_INIT, 867 }, 868 { 869 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 870 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 871 .mismatch = ANY_INIT_TO_ANY_EXIT, 872 }, 873 { 874 .fromsec = { "__ex_table", NULL }, 875 /* If you're adding any new black-listed sections in here, consider 876 * adding a special 'printer' for them in scripts/check_extable. 877 */ 878 .bad_tosec = { ".altinstr_replacement", NULL }, 879 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 880 .mismatch = EXTABLE_TO_NON_TEXT, 881 } 882 }; 883 884 static const struct sectioncheck *section_mismatch( 885 const char *fromsec, const char *tosec) 886 { 887 int i; 888 889 /* 890 * The target section could be the SHT_NUL section when we're 891 * handling relocations to un-resolved symbols, trying to match it 892 * doesn't make much sense and causes build failures on parisc 893 * architectures. 894 */ 895 if (*tosec == '\0') 896 return NULL; 897 898 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 899 const struct sectioncheck *check = §ioncheck[i]; 900 901 if (match(fromsec, check->fromsec)) { 902 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 903 return check; 904 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 905 return check; 906 } 907 } 908 return NULL; 909 } 910 911 /** 912 * Whitelist to allow certain references to pass with no warning. 913 * 914 * Pattern 1: 915 * If a module parameter is declared __initdata and permissions=0 916 * then this is legal despite the warning generated. 917 * We cannot see value of permissions here, so just ignore 918 * this pattern. 919 * The pattern is identified by: 920 * tosec = .init.data 921 * fromsec = .data* 922 * atsym =__param* 923 * 924 * Pattern 1a: 925 * module_param_call() ops can refer to __init set function if permissions=0 926 * The pattern is identified by: 927 * tosec = .init.text 928 * fromsec = .data* 929 * atsym = __param_ops_* 930 * 931 * Pattern 3: 932 * Whitelist all references from .head.text to any init section 933 * 934 * Pattern 4: 935 * Some symbols belong to init section but still it is ok to reference 936 * these from non-init sections as these symbols don't have any memory 937 * allocated for them and symbol address and value are same. So even 938 * if init section is freed, its ok to reference those symbols. 939 * For ex. symbols marking the init section boundaries. 940 * This pattern is identified by 941 * refsymname = __init_begin, _sinittext, _einittext 942 * 943 * Pattern 5: 944 * GCC may optimize static inlines when fed constant arg(s) resulting 945 * in functions like cpumask_empty() -- generating an associated symbol 946 * cpumask_empty.constprop.3 that appears in the audit. If the const that 947 * is passed in comes from __init, like say nmi_ipi_mask, we get a 948 * meaningless section warning. May need to add isra symbols too... 949 * This pattern is identified by 950 * tosec = init section 951 * fromsec = text section 952 * refsymname = *.constprop.* 953 * 954 **/ 955 static int secref_whitelist(const char *fromsec, const char *fromsym, 956 const char *tosec, const char *tosym) 957 { 958 /* Check for pattern 1 */ 959 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 960 match(fromsec, PATTERNS(DATA_SECTIONS)) && 961 strstarts(fromsym, "__param")) 962 return 0; 963 964 /* Check for pattern 1a */ 965 if (strcmp(tosec, ".init.text") == 0 && 966 match(fromsec, PATTERNS(DATA_SECTIONS)) && 967 strstarts(fromsym, "__param_ops_")) 968 return 0; 969 970 /* symbols in data sections that may refer to any init/exit sections */ 971 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 972 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 973 match(fromsym, PATTERNS("*_ops", "*_ops.llvm.*", "*_console"))) 974 return 0; 975 976 /* Check for pattern 3 */ 977 if (strstarts(fromsec, ".head.text") && 978 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 979 return 0; 980 981 /* Check for pattern 4 */ 982 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 983 return 0; 984 985 /* Check for pattern 5 */ 986 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 987 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 988 match(fromsym, PATTERNS("*.constprop.*"))) 989 return 0; 990 991 return 1; 992 } 993 994 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 995 unsigned int secndx) 996 { 997 return symsearch_find_nearest(elf, addr, secndx, false, ~0); 998 } 999 1000 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 1001 { 1002 Elf_Sym *new_sym; 1003 1004 /* If the supplied symbol has a valid name, return it */ 1005 if (is_valid_name(elf, sym)) 1006 return sym; 1007 1008 /* 1009 * Strive to find a better symbol name, but the resulting name may not 1010 * match the symbol referenced in the original code. 1011 */ 1012 new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym), 1013 true, 20); 1014 return new_sym ? new_sym : sym; 1015 } 1016 1017 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1018 { 1019 if (secndx >= elf->num_sections) 1020 return false; 1021 1022 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1023 } 1024 1025 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1026 const struct sectioncheck* const mismatch, 1027 Elf_Sym *tsym, 1028 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1029 const char *tosec, Elf_Addr taddr) 1030 { 1031 Elf_Sym *from; 1032 const char *tosym; 1033 const char *fromsym; 1034 char taddr_str[16]; 1035 1036 from = find_fromsym(elf, faddr, fsecndx); 1037 fromsym = sym_name(elf, from); 1038 1039 tsym = find_tosym(elf, taddr, tsym); 1040 tosym = sym_name(elf, tsym); 1041 1042 /* check whitelist - we may ignore it */ 1043 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1044 return; 1045 1046 sec_mismatch_count++; 1047 1048 if (!tosym[0]) 1049 snprintf(taddr_str, sizeof(taddr_str), "0x%x", (unsigned int)taddr); 1050 1051 /* 1052 * The format for the reference source: <symbol_name>+<offset> or <address> 1053 * The format for the reference destination: <symbol_name> or <address> 1054 */ 1055 warn("%s: section mismatch in reference: %s%s0x%x (section: %s) -> %s (section: %s)\n", 1056 modname, fromsym, fromsym[0] ? "+" : "", 1057 (unsigned int)(faddr - (fromsym[0] ? from->st_value : 0)), 1058 fromsec, tosym[0] ? tosym : taddr_str, tosec); 1059 1060 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1061 if (match(tosec, mismatch->bad_tosec)) 1062 fatal("The relocation at %s+0x%lx references\n" 1063 "section \"%s\" which is black-listed.\n" 1064 "Something is seriously wrong and should be fixed.\n" 1065 "You might get more information about where this is\n" 1066 "coming from by using scripts/check_extable.sh %s\n", 1067 fromsec, (long)faddr, tosec, modname); 1068 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1069 warn("The relocation at %s+0x%lx references\n" 1070 "section \"%s\" which is not in the list of\n" 1071 "authorized sections. If you're adding a new section\n" 1072 "and/or if this reference is valid, add \"%s\" to the\n" 1073 "list of authorized sections to jump to on fault.\n" 1074 "This can be achieved by adding \"%s\" to\n" 1075 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1076 fromsec, (long)faddr, tosec, tosec, tosec); 1077 else 1078 error("%s+0x%lx references non-executable section '%s'\n", 1079 fromsec, (long)faddr, tosec); 1080 } 1081 } 1082 1083 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1084 Elf_Addr faddr, const char *secname, 1085 Elf_Sym *sym) 1086 { 1087 static const char *prefix = "__export_symbol_"; 1088 const char *label_name, *name, *data; 1089 Elf_Sym *label; 1090 struct symbol *s; 1091 bool is_gpl; 1092 1093 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1094 label_name = sym_name(elf, label); 1095 1096 if (!strstarts(label_name, prefix)) { 1097 error("%s: .export_symbol section contains strange symbol '%s'\n", 1098 mod->name, label_name); 1099 return; 1100 } 1101 1102 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1103 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1104 error("%s: local symbol '%s' was exported\n", mod->name, 1105 label_name + strlen(prefix)); 1106 return; 1107 } 1108 1109 name = sym_name(elf, sym); 1110 if (strcmp(label_name + strlen(prefix), name)) { 1111 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1112 mod->name, name); 1113 return; 1114 } 1115 1116 data = sym_get_data(elf, label); /* license */ 1117 if (!strcmp(data, "GPL")) { 1118 is_gpl = true; 1119 } else if (!strcmp(data, "")) { 1120 is_gpl = false; 1121 } else { 1122 error("%s: unknown license '%s' was specified for '%s'\n", 1123 mod->name, data, name); 1124 return; 1125 } 1126 1127 data += strlen(data) + 1; /* namespace */ 1128 s = sym_add_exported(name, mod, is_gpl, data); 1129 1130 /* 1131 * We need to be aware whether we are exporting a function or 1132 * a data on some architectures. 1133 */ 1134 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1135 1136 /* 1137 * For parisc64, symbols prefixed $$ from the library have the symbol type 1138 * STT_LOPROC. They should be handled as functions too. 1139 */ 1140 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1141 elf->hdr->e_machine == EM_PARISC && 1142 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1143 s->is_func = true; 1144 1145 if (match(secname, PATTERNS(ALL_INIT_SECTIONS))) 1146 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1147 mod->name, name); 1148 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS))) 1149 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1150 mod->name, name); 1151 } 1152 1153 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1154 Elf_Sym *sym, 1155 unsigned int fsecndx, const char *fromsec, 1156 Elf_Addr faddr, Elf_Addr taddr) 1157 { 1158 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1159 const struct sectioncheck *mismatch; 1160 1161 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1162 check_export_symbol(mod, elf, faddr, tosec, sym); 1163 return; 1164 } 1165 1166 mismatch = section_mismatch(fromsec, tosec); 1167 if (!mismatch) 1168 return; 1169 1170 default_mismatch_handler(mod->name, elf, mismatch, sym, 1171 fsecndx, fromsec, faddr, 1172 tosec, taddr); 1173 } 1174 1175 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1176 { 1177 switch (r_type) { 1178 case R_386_32: 1179 return get_unaligned_native(location); 1180 case R_386_PC32: 1181 return get_unaligned_native(location) + 4; 1182 } 1183 1184 return (Elf_Addr)(-1); 1185 } 1186 1187 static int32_t sign_extend32(int32_t value, int index) 1188 { 1189 uint8_t shift = 31 - index; 1190 1191 return (int32_t)(value << shift) >> shift; 1192 } 1193 1194 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1195 { 1196 uint32_t inst, upper, lower, sign, j1, j2; 1197 int32_t offset; 1198 1199 switch (r_type) { 1200 case R_ARM_ABS32: 1201 case R_ARM_REL32: 1202 inst = get_unaligned_native((uint32_t *)loc); 1203 return inst + sym->st_value; 1204 case R_ARM_MOVW_ABS_NC: 1205 case R_ARM_MOVT_ABS: 1206 inst = get_unaligned_native((uint32_t *)loc); 1207 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1208 15); 1209 return offset + sym->st_value; 1210 case R_ARM_PC24: 1211 case R_ARM_CALL: 1212 case R_ARM_JUMP24: 1213 inst = get_unaligned_native((uint32_t *)loc); 1214 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1215 return offset + sym->st_value + 8; 1216 case R_ARM_THM_MOVW_ABS_NC: 1217 case R_ARM_THM_MOVT_ABS: 1218 upper = get_unaligned_native((uint16_t *)loc); 1219 lower = get_unaligned_native((uint16_t *)loc + 1); 1220 offset = sign_extend32(((upper & 0x000f) << 12) | 1221 ((upper & 0x0400) << 1) | 1222 ((lower & 0x7000) >> 4) | 1223 (lower & 0x00ff), 1224 15); 1225 return offset + sym->st_value; 1226 case R_ARM_THM_JUMP19: 1227 /* 1228 * Encoding T3: 1229 * S = upper[10] 1230 * imm6 = upper[5:0] 1231 * J1 = lower[13] 1232 * J2 = lower[11] 1233 * imm11 = lower[10:0] 1234 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1235 */ 1236 upper = get_unaligned_native((uint16_t *)loc); 1237 lower = get_unaligned_native((uint16_t *)loc + 1); 1238 1239 sign = (upper >> 10) & 1; 1240 j1 = (lower >> 13) & 1; 1241 j2 = (lower >> 11) & 1; 1242 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1243 ((upper & 0x03f) << 12) | 1244 ((lower & 0x07ff) << 1), 1245 20); 1246 return offset + sym->st_value + 4; 1247 case R_ARM_THM_PC22: 1248 case R_ARM_THM_JUMP24: 1249 /* 1250 * Encoding T4: 1251 * S = upper[10] 1252 * imm10 = upper[9:0] 1253 * J1 = lower[13] 1254 * J2 = lower[11] 1255 * imm11 = lower[10:0] 1256 * I1 = NOT(J1 XOR S) 1257 * I2 = NOT(J2 XOR S) 1258 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1259 */ 1260 upper = get_unaligned_native((uint16_t *)loc); 1261 lower = get_unaligned_native((uint16_t *)loc + 1); 1262 1263 sign = (upper >> 10) & 1; 1264 j1 = (lower >> 13) & 1; 1265 j2 = (lower >> 11) & 1; 1266 offset = sign_extend32((sign << 24) | 1267 ((~(j1 ^ sign) & 1) << 23) | 1268 ((~(j2 ^ sign) & 1) << 22) | 1269 ((upper & 0x03ff) << 12) | 1270 ((lower & 0x07ff) << 1), 1271 24); 1272 return offset + sym->st_value + 4; 1273 } 1274 1275 return (Elf_Addr)(-1); 1276 } 1277 1278 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1279 { 1280 uint32_t inst; 1281 1282 inst = get_unaligned_native(location); 1283 switch (r_type) { 1284 case R_MIPS_LO16: 1285 return inst & 0xffff; 1286 case R_MIPS_26: 1287 return (inst & 0x03ffffff) << 2; 1288 case R_MIPS_32: 1289 return inst; 1290 } 1291 return (Elf_Addr)(-1); 1292 } 1293 1294 #ifndef EM_RISCV 1295 #define EM_RISCV 243 1296 #endif 1297 1298 #ifndef R_RISCV_SUB32 1299 #define R_RISCV_SUB32 39 1300 #endif 1301 1302 #ifndef EM_LOONGARCH 1303 #define EM_LOONGARCH 258 1304 #endif 1305 1306 #ifndef R_LARCH_SUB32 1307 #define R_LARCH_SUB32 55 1308 #endif 1309 1310 #ifndef R_LARCH_RELAX 1311 #define R_LARCH_RELAX 100 1312 #endif 1313 1314 #ifndef R_LARCH_ALIGN 1315 #define R_LARCH_ALIGN 102 1316 #endif 1317 1318 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1319 unsigned int *r_type, unsigned int *r_sym) 1320 { 1321 typedef struct { 1322 Elf64_Word r_sym; /* Symbol index */ 1323 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1324 unsigned char r_type3; /* 3rd relocation type */ 1325 unsigned char r_type2; /* 2nd relocation type */ 1326 unsigned char r_type; /* 1st relocation type */ 1327 } Elf64_Mips_R_Info; 1328 1329 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1330 1331 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1332 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1333 1334 *r_type = mips64_r_info->r_type; 1335 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1336 return; 1337 } 1338 1339 if (is_64bit) 1340 r_info = TO_NATIVE((Elf64_Xword)r_info); 1341 else 1342 r_info = TO_NATIVE((Elf32_Word)r_info); 1343 1344 *r_type = ELF_R_TYPE(r_info); 1345 *r_sym = ELF_R_SYM(r_info); 1346 } 1347 1348 static void section_rela(struct module *mod, struct elf_info *elf, 1349 unsigned int fsecndx, const char *fromsec, 1350 const Elf_Rela *start, const Elf_Rela *stop) 1351 { 1352 const Elf_Rela *rela; 1353 1354 for (rela = start; rela < stop; rela++) { 1355 Elf_Sym *tsym; 1356 Elf_Addr taddr, r_offset; 1357 unsigned int r_type, r_sym; 1358 1359 r_offset = TO_NATIVE(rela->r_offset); 1360 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1361 1362 tsym = elf->symtab_start + r_sym; 1363 taddr = tsym->st_value + TO_NATIVE(rela->r_addend); 1364 1365 switch (elf->hdr->e_machine) { 1366 case EM_RISCV: 1367 if (!strcmp("__ex_table", fromsec) && 1368 r_type == R_RISCV_SUB32) 1369 continue; 1370 break; 1371 case EM_LOONGARCH: 1372 switch (r_type) { 1373 case R_LARCH_SUB32: 1374 if (!strcmp("__ex_table", fromsec)) 1375 continue; 1376 break; 1377 case R_LARCH_RELAX: 1378 case R_LARCH_ALIGN: 1379 /* These relocs do not refer to symbols */ 1380 continue; 1381 } 1382 break; 1383 } 1384 1385 check_section_mismatch(mod, elf, tsym, 1386 fsecndx, fromsec, r_offset, taddr); 1387 } 1388 } 1389 1390 static void section_rel(struct module *mod, struct elf_info *elf, 1391 unsigned int fsecndx, const char *fromsec, 1392 const Elf_Rel *start, const Elf_Rel *stop) 1393 { 1394 const Elf_Rel *rel; 1395 1396 for (rel = start; rel < stop; rel++) { 1397 Elf_Sym *tsym; 1398 Elf_Addr taddr, r_offset; 1399 unsigned int r_type, r_sym; 1400 void *loc; 1401 1402 r_offset = TO_NATIVE(rel->r_offset); 1403 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1404 1405 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1406 tsym = elf->symtab_start + r_sym; 1407 1408 switch (elf->hdr->e_machine) { 1409 case EM_386: 1410 taddr = addend_386_rel(loc, r_type); 1411 break; 1412 case EM_ARM: 1413 taddr = addend_arm_rel(loc, tsym, r_type); 1414 break; 1415 case EM_MIPS: 1416 taddr = addend_mips_rel(loc, r_type); 1417 break; 1418 default: 1419 fatal("Please add code to calculate addend for this architecture\n"); 1420 } 1421 1422 check_section_mismatch(mod, elf, tsym, 1423 fsecndx, fromsec, r_offset, taddr); 1424 } 1425 } 1426 1427 /** 1428 * A module includes a number of sections that are discarded 1429 * either when loaded or when used as built-in. 1430 * For loaded modules all functions marked __init and all data 1431 * marked __initdata will be discarded when the module has been initialized. 1432 * Likewise for modules used built-in the sections marked __exit 1433 * are discarded because __exit marked function are supposed to be called 1434 * only when a module is unloaded which never happens for built-in modules. 1435 * The check_sec_ref() function traverses all relocation records 1436 * to find all references to a section that reference a section that will 1437 * be discarded and warns about it. 1438 **/ 1439 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1440 { 1441 int i; 1442 1443 /* Walk through all sections */ 1444 for (i = 0; i < elf->num_sections; i++) { 1445 Elf_Shdr *sechdr = &elf->sechdrs[i]; 1446 1447 check_section(mod->name, elf, sechdr); 1448 /* We want to process only relocation sections and not .init */ 1449 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) { 1450 /* section to which the relocation applies */ 1451 unsigned int secndx = sechdr->sh_info; 1452 const char *secname = sec_name(elf, secndx); 1453 const void *start, *stop; 1454 1455 /* If the section is known good, skip it */ 1456 if (match(secname, section_white_list)) 1457 continue; 1458 1459 start = sym_get_data_by_offset(elf, i, 0); 1460 stop = start + sechdr->sh_size; 1461 1462 if (sechdr->sh_type == SHT_RELA) 1463 section_rela(mod, elf, secndx, secname, 1464 start, stop); 1465 else 1466 section_rel(mod, elf, secndx, secname, 1467 start, stop); 1468 } 1469 } 1470 } 1471 1472 static char *remove_dot(char *s) 1473 { 1474 size_t n = strcspn(s, "."); 1475 1476 if (n && s[n]) { 1477 size_t m = strspn(s + n + 1, "0123456789"); 1478 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1479 s[n] = 0; 1480 } 1481 return s; 1482 } 1483 1484 /* 1485 * The CRCs are recorded in .*.cmd files in the form of: 1486 * #SYMVER <name> <crc> 1487 */ 1488 static void extract_crcs_for_object(const char *object, struct module *mod) 1489 { 1490 char cmd_file[PATH_MAX]; 1491 char *buf, *p; 1492 const char *base; 1493 int dirlen, baselen_without_suffix, ret; 1494 1495 base = get_basename(object); 1496 dirlen = base - object; 1497 1498 baselen_without_suffix = strlen(object) - dirlen - strlen(".o"); 1499 1500 /* 1501 * When CONFIG_LTO_CLANG_THIN_DIST=y, the ELF is *.thinlto-native.o 1502 * but the symbol CRCs are recorded in *.o.cmd file. 1503 */ 1504 if (strends(object, ".thinlto-native.o")) 1505 baselen_without_suffix -= strlen(".thinlto-native"); 1506 1507 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%.*s.o.cmd", 1508 dirlen, object, baselen_without_suffix, base); 1509 if (ret >= sizeof(cmd_file)) { 1510 error("%s: too long path was truncated\n", cmd_file); 1511 return; 1512 } 1513 1514 buf = read_text_file(cmd_file); 1515 p = buf; 1516 1517 while ((p = strstr(p, "\n#SYMVER "))) { 1518 char *name; 1519 size_t namelen; 1520 unsigned int crc; 1521 struct symbol *sym; 1522 1523 name = p + strlen("\n#SYMVER "); 1524 1525 p = strchr(name, ' '); 1526 if (!p) 1527 break; 1528 1529 namelen = p - name; 1530 p++; 1531 1532 if (!isdigit(*p)) 1533 continue; /* skip this line */ 1534 1535 crc = strtoul(p, &p, 0); 1536 if (*p != '\n') 1537 continue; /* skip this line */ 1538 1539 name[namelen] = '\0'; 1540 1541 /* 1542 * sym_find_with_module() may return NULL here. 1543 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1544 * Since commit e1327a127703, genksyms calculates CRCs of all 1545 * symbols, including trimmed ones. Ignore orphan CRCs. 1546 */ 1547 sym = sym_find_with_module(name, mod); 1548 if (sym) 1549 sym_set_crc(sym, crc); 1550 } 1551 1552 free(buf); 1553 } 1554 1555 /* 1556 * The symbol versions (CRC) are recorded in the .*.cmd files. 1557 * Parse them to retrieve CRCs for the current module. 1558 */ 1559 static void mod_set_crcs(struct module *mod) 1560 { 1561 char objlist[PATH_MAX]; 1562 char *buf, *p, *obj; 1563 int ret; 1564 1565 if (mod->is_vmlinux) { 1566 strcpy(objlist, ".vmlinux.objs"); 1567 } else { 1568 /* objects for a module are listed in the *.mod file. */ 1569 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1570 if (ret >= sizeof(objlist)) { 1571 error("%s: too long path was truncated\n", objlist); 1572 return; 1573 } 1574 } 1575 1576 buf = read_text_file(objlist); 1577 p = buf; 1578 1579 while ((obj = strsep(&p, "\n")) && obj[0]) 1580 extract_crcs_for_object(obj, mod); 1581 1582 free(buf); 1583 } 1584 1585 static void read_symbols(const char *modname) 1586 { 1587 const char *symname; 1588 char *version; 1589 char *license; 1590 char *namespace; 1591 struct module *mod; 1592 struct elf_info info = { }; 1593 Elf_Sym *sym; 1594 1595 if (!parse_elf(&info, modname)) 1596 return; 1597 1598 if (!strends(modname, ".o")) { 1599 error("%s: filename must be suffixed with .o\n", modname); 1600 return; 1601 } 1602 1603 /* strip trailing .o */ 1604 mod = new_module(modname, strlen(modname) - strlen(".o")); 1605 1606 /* save .no_trim_symbol section for later use */ 1607 if (info.no_trim_symbol_len) { 1608 mod->no_trim_symbol = xmalloc(info.no_trim_symbol_len); 1609 memcpy(mod->no_trim_symbol, info.no_trim_symbol, 1610 info.no_trim_symbol_len); 1611 mod->no_trim_symbol_len = info.no_trim_symbol_len; 1612 } 1613 1614 if (!mod->is_vmlinux) { 1615 license = get_modinfo(&info, "license"); 1616 if (!license) 1617 error("missing MODULE_LICENSE() in %s\n", modname); 1618 while (license) { 1619 if (!license_is_gpl_compatible(license)) { 1620 mod->is_gpl_compatible = false; 1621 break; 1622 } 1623 license = get_next_modinfo(&info, "license", license); 1624 } 1625 1626 for (namespace = get_modinfo(&info, "import_ns"); 1627 namespace; 1628 namespace = get_next_modinfo(&info, "import_ns", namespace)) { 1629 if (strstarts(namespace, MODULE_NS_PREFIX)) 1630 error("%s: explicitly importing namespace \"%s\" is not allowed.\n", 1631 mod->name, namespace); 1632 1633 add_namespace(&mod->imported_namespaces, namespace); 1634 } 1635 1636 if (!get_modinfo(&info, "description")) 1637 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1638 } 1639 1640 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1641 symname = remove_dot(info.strtab + sym->st_name); 1642 1643 handle_symbol(mod, &info, sym, symname); 1644 handle_moddevtable(mod, &info, sym, symname); 1645 } 1646 1647 check_sec_ref(mod, &info); 1648 1649 if (!mod->is_vmlinux) { 1650 version = get_modinfo(&info, "version"); 1651 if (version || all_versions) 1652 get_src_version(mod->name, mod->srcversion, 1653 sizeof(mod->srcversion) - 1); 1654 } 1655 1656 parse_elf_finish(&info); 1657 1658 if (modversions) { 1659 /* 1660 * Our trick to get versioning for module struct etc. - it's 1661 * never passed as an argument to an exported function, so 1662 * the automatic versioning doesn't pick it up, but it's really 1663 * important anyhow. 1664 */ 1665 sym_add_unresolved("module_layout", mod, false); 1666 1667 mod_set_crcs(mod); 1668 } 1669 } 1670 1671 static void read_symbols_from_files(const char *filename) 1672 { 1673 FILE *in = stdin; 1674 char fname[PATH_MAX]; 1675 1676 in = fopen(filename, "r"); 1677 if (!in) 1678 fatal("Can't open filenames file %s: %m", filename); 1679 1680 while (fgets(fname, PATH_MAX, in) != NULL) { 1681 if (strends(fname, "\n")) 1682 fname[strlen(fname)-1] = '\0'; 1683 read_symbols(fname); 1684 } 1685 1686 fclose(in); 1687 } 1688 1689 #define SZ 500 1690 1691 /* We first write the generated file into memory using the 1692 * following helper, then compare to the file on disk and 1693 * only update the later if anything changed */ 1694 1695 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1696 const char *fmt, ...) 1697 { 1698 char tmp[SZ]; 1699 int len; 1700 va_list ap; 1701 1702 va_start(ap, fmt); 1703 len = vsnprintf(tmp, SZ, fmt, ap); 1704 va_end(ap); 1705 1706 if (len < 0) { 1707 perror("vsnprintf failed"); 1708 exit(1); 1709 } 1710 if (len >= SZ) 1711 fatal("buf_printf output truncated for string %s: %d bytes needed, %d available\n", 1712 tmp, len + 1, SZ); 1713 1714 buf_write(buf, tmp, len); 1715 } 1716 1717 void buf_write(struct buffer *buf, const char *s, int len) 1718 { 1719 if (buf->size - buf->pos < len) { 1720 buf->size += len + SZ; 1721 buf->p = xrealloc(buf->p, buf->size); 1722 } 1723 strncpy(buf->p + buf->pos, s, len); 1724 buf->pos += len; 1725 } 1726 1727 /** 1728 * verify_module_namespace() - does @modname have access to this symbol's @namespace 1729 * @namespace: export symbol namespace 1730 * @modname: module name 1731 * 1732 * If @namespace is prefixed with "module:" to indicate it is a module namespace 1733 * then test if @modname matches any of the comma separated patterns. 1734 * 1735 * The patterns only support tail-glob. 1736 */ 1737 static bool verify_module_namespace(const char *namespace, const char *modname) 1738 { 1739 size_t len, modlen = strlen(modname); 1740 const char *prefix = "module:"; 1741 const char *sep; 1742 bool glob; 1743 1744 if (!strstarts(namespace, prefix)) 1745 return false; 1746 1747 for (namespace += strlen(prefix); *namespace; namespace = sep) { 1748 sep = strchrnul(namespace, ','); 1749 len = sep - namespace; 1750 1751 glob = false; 1752 if (sep[-1] == '*') { 1753 len--; 1754 glob = true; 1755 } 1756 1757 if (*sep) 1758 sep++; 1759 1760 if (strncmp(namespace, modname, len) == 0 && (glob || len == modlen)) 1761 return true; 1762 } 1763 1764 return false; 1765 } 1766 1767 static void check_exports(struct module *mod) 1768 { 1769 struct symbol *s, *exp; 1770 1771 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1772 const char *basename; 1773 exp = find_symbol(s->name); 1774 if (!exp) { 1775 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1776 modpost_log(!warn_unresolved, 1777 "\"%s\" [%s.ko] undefined!\n", 1778 s->name, mod->name); 1779 continue; 1780 } 1781 if (exp->module == mod) { 1782 error("\"%s\" [%s.ko] was exported without definition\n", 1783 s->name, mod->name); 1784 continue; 1785 } 1786 1787 exp->used = true; 1788 s->module = exp->module; 1789 s->crc_valid = exp->crc_valid; 1790 s->crc = exp->crc; 1791 1792 basename = get_basename(mod->name); 1793 1794 if (!verify_module_namespace(exp->namespace, basename) && 1795 !contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1796 modpost_log(!allow_missing_ns_imports, 1797 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1798 basename, exp->name, exp->namespace); 1799 add_namespace(&mod->missing_namespaces, exp->namespace); 1800 } 1801 1802 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1803 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1804 basename, exp->name); 1805 } 1806 } 1807 1808 static void handle_white_list_exports(const char *white_list) 1809 { 1810 char *buf, *p, *name; 1811 1812 buf = read_text_file(white_list); 1813 p = buf; 1814 1815 while ((name = strsep(&p, "\n"))) { 1816 struct symbol *sym = find_symbol(name); 1817 1818 if (sym) 1819 sym->used = true; 1820 } 1821 1822 free(buf); 1823 } 1824 1825 /* 1826 * Keep symbols recorded in the .no_trim_symbol section. This is necessary to 1827 * prevent CONFIG_TRIM_UNUSED_KSYMS from dropping EXPORT_SYMBOL because 1828 * symbol_get() relies on the symbol being present in the ksymtab for lookups. 1829 */ 1830 static void keep_no_trim_symbols(struct module *mod) 1831 { 1832 unsigned long size = mod->no_trim_symbol_len; 1833 1834 for (char *s = mod->no_trim_symbol; s; s = next_string(s , &size)) { 1835 struct symbol *sym; 1836 1837 /* 1838 * If find_symbol() returns NULL, this symbol is not provided 1839 * by any module, and symbol_get() will fail. 1840 */ 1841 sym = find_symbol(s); 1842 if (sym) 1843 sym->used = true; 1844 } 1845 } 1846 1847 static void check_modname_len(struct module *mod) 1848 { 1849 const char *mod_name; 1850 1851 mod_name = get_basename(mod->name); 1852 1853 if (strlen(mod_name) >= MODULE_NAME_LEN) 1854 error("module name is too long [%s.ko]\n", mod->name); 1855 } 1856 1857 /** 1858 * Header for the generated file 1859 **/ 1860 static void add_header(struct buffer *b, struct module *mod) 1861 { 1862 buf_printf(b, "#include <linux/module.h>\n"); 1863 buf_printf(b, "#include <linux/export-internal.h>\n"); 1864 buf_printf(b, "#include <linux/compiler.h>\n"); 1865 buf_printf(b, "\n"); 1866 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1867 buf_printf(b, "\n"); 1868 buf_printf(b, "__visible struct module __this_module\n"); 1869 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1870 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1871 if (mod->has_init) 1872 buf_printf(b, "\t.init = init_module,\n"); 1873 if (mod->has_cleanup) 1874 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1875 "\t.exit = cleanup_module,\n" 1876 "#endif\n"); 1877 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1878 buf_printf(b, "};\n"); 1879 1880 if (!external_module) 1881 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1882 1883 if (strstarts(mod->name, "drivers/staging")) 1884 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1885 1886 if (strstarts(mod->name, "tools/testing")) 1887 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1888 } 1889 1890 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1891 { 1892 struct symbol *sym; 1893 1894 /* generate struct for exported symbols */ 1895 buf_printf(buf, "\n"); 1896 list_for_each_entry(sym, &mod->exported_symbols, list) { 1897 if (trim_unused_exports && !sym->used) 1898 continue; 1899 1900 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\");\n", 1901 sym->is_func ? "FUNC" : "DATA", sym->name, 1902 sym->namespace); 1903 1904 buf_printf(buf, "SYMBOL_FLAGS(%s, 0x%02x);\n", 1905 sym->name, get_symbol_flags(sym)); 1906 } 1907 1908 if (!modversions) 1909 return; 1910 1911 /* record CRCs for exported symbols */ 1912 buf_printf(buf, "\n"); 1913 list_for_each_entry(sym, &mod->exported_symbols, list) { 1914 if (trim_unused_exports && !sym->used) 1915 continue; 1916 1917 if (!sym->crc_valid) 1918 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1919 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1920 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1921 sym->name); 1922 1923 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x);\n", 1924 sym->name, sym->crc); 1925 } 1926 } 1927 1928 /** 1929 * Record CRCs for unresolved symbols, supporting long names 1930 */ 1931 static void add_extended_versions(struct buffer *b, struct module *mod) 1932 { 1933 struct symbol *s; 1934 1935 if (!extended_modversions) 1936 return; 1937 1938 buf_printf(b, "\n"); 1939 buf_printf(b, "static const u32 ____version_ext_crcs[]\n"); 1940 buf_printf(b, "__used __section(\"__version_ext_crcs\") = {\n"); 1941 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1942 if (!s->module) 1943 continue; 1944 if (!s->crc_valid) { 1945 warn("\"%s\" [%s.ko] has no CRC!\n", 1946 s->name, mod->name); 1947 continue; 1948 } 1949 buf_printf(b, "\t0x%08x,\n", s->crc); 1950 } 1951 buf_printf(b, "};\n"); 1952 1953 buf_printf(b, "static const char ____version_ext_names[]\n"); 1954 buf_printf(b, "__used __section(\"__version_ext_names\") =\n"); 1955 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1956 if (!s->module) 1957 continue; 1958 if (!s->crc_valid) 1959 /* 1960 * We already warned on this when producing the crc 1961 * table. 1962 * We need to skip its name too, as the indexes in 1963 * both tables need to align. 1964 */ 1965 continue; 1966 buf_printf(b, "\t\"%s\\0\"\n", s->name); 1967 } 1968 buf_printf(b, ";\n"); 1969 } 1970 1971 /** 1972 * Record CRCs for unresolved symbols 1973 **/ 1974 static void add_versions(struct buffer *b, struct module *mod) 1975 { 1976 struct symbol *s; 1977 1978 if (!basic_modversions) 1979 return; 1980 1981 buf_printf(b, "\n"); 1982 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1983 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1984 1985 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1986 if (!s->module) 1987 continue; 1988 if (!s->crc_valid) { 1989 warn("\"%s\" [%s.ko] has no CRC!\n", 1990 s->name, mod->name); 1991 continue; 1992 } 1993 if (strlen(s->name) >= MODULE_NAME_LEN) { 1994 if (extended_modversions) { 1995 /* this symbol will only be in the extended info */ 1996 continue; 1997 } else { 1998 error("too long symbol \"%s\" [%s.ko]\n", 1999 s->name, mod->name); 2000 break; 2001 } 2002 } 2003 buf_printf(b, "\t{ 0x%08x, \"%s\" },\n", 2004 s->crc, s->name); 2005 } 2006 2007 buf_printf(b, "};\n"); 2008 } 2009 2010 static void add_depends(struct buffer *b, struct module *mod) 2011 { 2012 struct symbol *s; 2013 int first = 1; 2014 2015 /* Clear ->seen flag of modules that own symbols needed by this. */ 2016 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2017 if (s->module) 2018 s->module->seen = s->module->is_vmlinux; 2019 } 2020 2021 buf_printf(b, "\n"); 2022 buf_printf(b, "MODULE_INFO(depends, \""); 2023 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2024 const char *p; 2025 if (!s->module) 2026 continue; 2027 2028 if (s->module->seen) 2029 continue; 2030 2031 s->module->seen = true; 2032 p = get_basename(s->module->name); 2033 buf_printf(b, "%s%s", first ? "" : ",", p); 2034 first = 0; 2035 } 2036 buf_printf(b, "\");\n"); 2037 } 2038 2039 static void add_srcversion(struct buffer *b, struct module *mod) 2040 { 2041 if (mod->srcversion[0]) { 2042 buf_printf(b, "\n"); 2043 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 2044 mod->srcversion); 2045 } 2046 } 2047 2048 static void write_buf(struct buffer *b, const char *fname) 2049 { 2050 FILE *file; 2051 2052 if (error_occurred) 2053 return; 2054 2055 file = fopen(fname, "w"); 2056 if (!file) { 2057 perror(fname); 2058 exit(1); 2059 } 2060 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2061 perror(fname); 2062 exit(1); 2063 } 2064 if (fclose(file) != 0) { 2065 perror(fname); 2066 exit(1); 2067 } 2068 } 2069 2070 static void write_if_changed(struct buffer *b, const char *fname) 2071 { 2072 char *tmp; 2073 FILE *file; 2074 struct stat st; 2075 2076 file = fopen(fname, "r"); 2077 if (!file) 2078 goto write; 2079 2080 if (fstat(fileno(file), &st) < 0) 2081 goto close_write; 2082 2083 if (st.st_size != b->pos) 2084 goto close_write; 2085 2086 tmp = xmalloc(b->pos); 2087 if (fread(tmp, 1, b->pos, file) != b->pos) 2088 goto free_write; 2089 2090 if (memcmp(tmp, b->p, b->pos) != 0) 2091 goto free_write; 2092 2093 free(tmp); 2094 fclose(file); 2095 return; 2096 2097 free_write: 2098 free(tmp); 2099 close_write: 2100 fclose(file); 2101 write: 2102 write_buf(b, fname); 2103 } 2104 2105 static void write_vmlinux_export_c_file(struct module *mod) 2106 { 2107 struct buffer buf = { }; 2108 struct module_alias *alias, *next; 2109 2110 buf_printf(&buf, 2111 "#include <linux/export-internal.h>\n"); 2112 2113 add_exported_symbols(&buf, mod); 2114 2115 buf_printf(&buf, 2116 "#include <linux/module.h>\n" 2117 "#undef __MODULE_INFO_PREFIX\n" 2118 "#define __MODULE_INFO_PREFIX\n"); 2119 2120 list_for_each_entry_safe(alias, next, &mod->aliases, node) { 2121 buf_printf(&buf, "MODULE_INFO(%s.alias, \"%s\");\n", 2122 alias->builtin_modname, alias->str); 2123 list_del(&alias->node); 2124 free(alias->builtin_modname); 2125 free(alias); 2126 } 2127 2128 write_if_changed(&buf, ".vmlinux.export.c"); 2129 free(buf.p); 2130 } 2131 2132 /* do sanity checks, and generate *.mod.c file */ 2133 static void write_mod_c_file(struct module *mod) 2134 { 2135 struct buffer buf = { }; 2136 struct module_alias *alias, *next; 2137 char fname[PATH_MAX]; 2138 int ret; 2139 2140 add_header(&buf, mod); 2141 add_exported_symbols(&buf, mod); 2142 add_versions(&buf, mod); 2143 add_extended_versions(&buf, mod); 2144 add_depends(&buf, mod); 2145 2146 buf_printf(&buf, "\n"); 2147 list_for_each_entry_safe(alias, next, &mod->aliases, node) { 2148 buf_printf(&buf, "MODULE_ALIAS(\"%s\");\n", alias->str); 2149 list_del(&alias->node); 2150 free(alias); 2151 } 2152 2153 add_srcversion(&buf, mod); 2154 2155 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2156 if (ret >= sizeof(fname)) { 2157 error("%s: too long path was truncated\n", fname); 2158 goto free; 2159 } 2160 2161 write_if_changed(&buf, fname); 2162 2163 free: 2164 free(buf.p); 2165 } 2166 2167 /* parse Module.symvers file. line format: 2168 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2169 **/ 2170 static void read_dump(const char *fname) 2171 { 2172 char *buf, *pos, *line; 2173 2174 buf = read_text_file(fname); 2175 if (!buf) 2176 /* No symbol versions, silently ignore */ 2177 return; 2178 2179 pos = buf; 2180 2181 while ((line = get_line(&pos))) { 2182 char *symname, *namespace, *modname, *d, *export; 2183 unsigned int crc; 2184 struct module *mod; 2185 struct symbol *s; 2186 bool gpl_only; 2187 2188 if (!(symname = strchr(line, '\t'))) 2189 goto fail; 2190 *symname++ = '\0'; 2191 if (!(modname = strchr(symname, '\t'))) 2192 goto fail; 2193 *modname++ = '\0'; 2194 if (!(export = strchr(modname, '\t'))) 2195 goto fail; 2196 *export++ = '\0'; 2197 if (!(namespace = strchr(export, '\t'))) 2198 goto fail; 2199 *namespace++ = '\0'; 2200 2201 crc = strtoul(line, &d, 16); 2202 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2203 goto fail; 2204 2205 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2206 gpl_only = true; 2207 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2208 gpl_only = false; 2209 } else { 2210 error("%s: unknown license %s. skip", symname, export); 2211 continue; 2212 } 2213 2214 mod = find_module(fname, modname); 2215 if (!mod) { 2216 mod = new_module(modname, strlen(modname)); 2217 mod->dump_file = fname; 2218 } 2219 s = sym_add_exported(symname, mod, gpl_only, namespace); 2220 sym_set_crc(s, crc); 2221 } 2222 free(buf); 2223 return; 2224 fail: 2225 free(buf); 2226 fatal("parse error in symbol dump file\n"); 2227 } 2228 2229 static void write_dump(const char *fname) 2230 { 2231 struct buffer buf = { }; 2232 struct module *mod; 2233 struct symbol *sym; 2234 2235 list_for_each_entry(mod, &modules, list) { 2236 if (mod->dump_file) 2237 continue; 2238 list_for_each_entry(sym, &mod->exported_symbols, list) { 2239 if (trim_unused_exports && !sym->used) 2240 continue; 2241 2242 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2243 sym->crc, sym->name, mod->name, 2244 sym->is_gpl_only ? "_GPL" : "", 2245 sym->namespace); 2246 } 2247 } 2248 write_buf(&buf, fname); 2249 free(buf.p); 2250 } 2251 2252 static void write_namespace_deps_files(const char *fname) 2253 { 2254 struct module *mod; 2255 struct namespace_list *ns; 2256 struct buffer ns_deps_buf = {}; 2257 2258 list_for_each_entry(mod, &modules, list) { 2259 2260 if (mod->dump_file || list_empty(&mod->missing_namespaces)) 2261 continue; 2262 2263 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2264 2265 list_for_each_entry(ns, &mod->missing_namespaces, list) 2266 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2267 2268 buf_printf(&ns_deps_buf, "\n"); 2269 } 2270 2271 write_if_changed(&ns_deps_buf, fname); 2272 free(ns_deps_buf.p); 2273 } 2274 2275 struct dump_list { 2276 struct list_head list; 2277 const char *file; 2278 }; 2279 2280 static void check_host_endian(void) 2281 { 2282 static const union { 2283 short s; 2284 char c[2]; 2285 } endian_test = { .c = {0x01, 0x02} }; 2286 2287 switch (endian_test.s) { 2288 case 0x0102: 2289 host_is_big_endian = true; 2290 break; 2291 case 0x0201: 2292 host_is_big_endian = false; 2293 break; 2294 default: 2295 fatal("Unknown host endian\n"); 2296 } 2297 } 2298 2299 int main(int argc, char **argv) 2300 { 2301 struct module *mod; 2302 char *missing_namespace_deps = NULL; 2303 char *unused_exports_white_list = NULL; 2304 char *dump_write = NULL, *files_source = NULL; 2305 int opt; 2306 LIST_HEAD(dump_lists); 2307 struct dump_list *dl, *dl2; 2308 2309 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:xb")) != -1) { 2310 switch (opt) { 2311 case 'e': 2312 external_module = true; 2313 break; 2314 case 'i': 2315 dl = xmalloc(sizeof(*dl)); 2316 dl->file = optarg; 2317 list_add_tail(&dl->list, &dump_lists); 2318 break; 2319 case 'M': 2320 module_enabled = true; 2321 break; 2322 case 'm': 2323 modversions = true; 2324 break; 2325 case 'n': 2326 ignore_missing_files = true; 2327 break; 2328 case 'o': 2329 dump_write = optarg; 2330 break; 2331 case 'a': 2332 all_versions = true; 2333 break; 2334 case 'T': 2335 files_source = optarg; 2336 break; 2337 case 't': 2338 trim_unused_exports = true; 2339 break; 2340 case 'u': 2341 unused_exports_white_list = optarg; 2342 break; 2343 case 'W': 2344 extra_warn = true; 2345 break; 2346 case 'w': 2347 warn_unresolved = true; 2348 break; 2349 case 'E': 2350 sec_mismatch_warn_only = false; 2351 break; 2352 case 'N': 2353 allow_missing_ns_imports = true; 2354 break; 2355 case 'd': 2356 missing_namespace_deps = optarg; 2357 break; 2358 case 'b': 2359 basic_modversions = true; 2360 break; 2361 case 'x': 2362 extended_modversions = true; 2363 break; 2364 default: 2365 exit(1); 2366 } 2367 } 2368 2369 check_host_endian(); 2370 2371 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2372 read_dump(dl->file); 2373 list_del(&dl->list); 2374 free(dl); 2375 } 2376 2377 while (optind < argc) 2378 read_symbols(argv[optind++]); 2379 2380 if (files_source) 2381 read_symbols_from_files(files_source); 2382 2383 list_for_each_entry(mod, &modules, list) { 2384 keep_no_trim_symbols(mod); 2385 2386 if (mod->dump_file || mod->is_vmlinux) 2387 continue; 2388 2389 check_modname_len(mod); 2390 check_exports(mod); 2391 } 2392 2393 if (unused_exports_white_list) 2394 handle_white_list_exports(unused_exports_white_list); 2395 2396 list_for_each_entry(mod, &modules, list) { 2397 if (mod->dump_file) 2398 continue; 2399 2400 if (mod->is_vmlinux) 2401 write_vmlinux_export_c_file(mod); 2402 else 2403 write_mod_c_file(mod); 2404 } 2405 2406 if (missing_namespace_deps) 2407 write_namespace_deps_files(missing_namespace_deps); 2408 2409 if (dump_write) 2410 write_dump(dump_write); 2411 if (sec_mismatch_count && !sec_mismatch_warn_only) 2412 error("Section mismatches detected.\n" 2413 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2414 2415 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2416 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2417 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2418 2419 return error_occurred ? 1 : 0; 2420 } 2421