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