1 /* Postprocess module symbol versions 2 * 3 * Copyright 2003 Kai Germaschewski 4 * Copyright 2002-2004 Rusty Russell, IBM Corporation 5 * Copyright 2006-2008 Sam Ravnborg 6 * Based in part on module-init-tools/depmod.c,file2alias 7 * 8 * This software may be used and distributed according to the terms 9 * of the GNU General Public License, incorporated herein by reference. 10 * 11 * Usage: modpost vmlinux module1.o module2.o ... 12 */ 13 14 #define _GNU_SOURCE 15 #include <elf.h> 16 #include <fnmatch.h> 17 #include <stdio.h> 18 #include <ctype.h> 19 #include <string.h> 20 #include <limits.h> 21 #include <stdbool.h> 22 #include <errno.h> 23 24 #include <hash.h> 25 #include <hashtable.h> 26 #include <list.h> 27 #include <xalloc.h> 28 #include "modpost.h" 29 #include "../../include/linux/license.h" 30 31 #define MODULE_NS_PREFIX "module:" 32 33 static bool module_enabled; 34 /* Are we using CONFIG_MODVERSIONS? */ 35 static bool modversions; 36 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 37 static bool all_versions; 38 /* Is CONFIG_BASIC_MODVERSIONS set? */ 39 static bool basic_modversions; 40 /* Is CONFIG_EXTENDED_MODVERSIONS set? */ 41 static bool extended_modversions; 42 /* If we are modposting external module set to 1 */ 43 static bool external_module; 44 /* Only warn about unresolved symbols */ 45 static bool warn_unresolved; 46 47 static int sec_mismatch_count; 48 static bool sec_mismatch_warn_only = true; 49 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */ 50 static bool trim_unused_exports; 51 52 /* ignore missing files */ 53 static bool ignore_missing_files; 54 /* If set to 1, only warn (instead of error) about missing ns imports */ 55 static bool allow_missing_ns_imports; 56 57 static bool error_occurred; 58 59 static bool extra_warn; 60 61 bool target_is_big_endian; 62 bool host_is_big_endian; 63 64 /* 65 * Cut off the warnings when there are too many. This typically occurs when 66 * vmlinux is missing. ('make modules' without building vmlinux.) 67 */ 68 #define MAX_UNRESOLVED_REPORTS 10 69 static unsigned int nr_unresolved; 70 71 /* In kernel, this size is defined in linux/module.h; 72 * here we use Elf_Addr instead of long for covering cross-compile 73 */ 74 75 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) 76 77 void modpost_log(bool is_error, const char *fmt, ...) 78 { 79 va_list arglist; 80 81 if (is_error) { 82 fprintf(stderr, "ERROR: "); 83 error_occurred = true; 84 } else { 85 fprintf(stderr, "WARNING: "); 86 } 87 88 fprintf(stderr, "modpost: "); 89 90 va_start(arglist, fmt); 91 vfprintf(stderr, fmt, arglist); 92 va_end(arglist); 93 } 94 95 static inline bool strends(const char *str, const char *postfix) 96 { 97 if (strlen(str) < strlen(postfix)) 98 return false; 99 100 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; 101 } 102 103 /** 104 * get_basename - return the last part of a pathname. 105 * 106 * @path: path to extract the filename from. 107 */ 108 const char *get_basename(const char *path) 109 { 110 const char *tail = strrchr(path, '/'); 111 112 return tail ? tail + 1 : path; 113 } 114 115 char *read_text_file(const char *filename) 116 { 117 struct stat st; 118 size_t nbytes; 119 int fd; 120 char *buf; 121 122 fd = open(filename, O_RDONLY); 123 if (fd < 0) { 124 perror(filename); 125 exit(1); 126 } 127 128 if (fstat(fd, &st) < 0) { 129 perror(filename); 130 exit(1); 131 } 132 133 buf = xmalloc(st.st_size + 1); 134 135 nbytes = st.st_size; 136 137 while (nbytes) { 138 ssize_t bytes_read; 139 140 bytes_read = read(fd, buf, nbytes); 141 if (bytes_read < 0) { 142 perror(filename); 143 exit(1); 144 } 145 146 nbytes -= bytes_read; 147 } 148 buf[st.st_size] = '\0'; 149 150 close(fd); 151 152 return buf; 153 } 154 155 char *get_line(char **stringp) 156 { 157 char *orig = *stringp, *next; 158 159 /* do not return the unwanted extra line at EOF */ 160 if (!orig || *orig == '\0') 161 return NULL; 162 163 /* don't use strsep here, it is not available everywhere */ 164 next = strchr(orig, '\n'); 165 if (next) 166 *next++ = '\0'; 167 168 *stringp = next; 169 170 return orig; 171 } 172 173 /* A list of all modules we processed */ 174 LIST_HEAD(modules); 175 176 static struct module *find_module(const char *filename, const char *modname) 177 { 178 struct module *mod; 179 180 list_for_each_entry(mod, &modules, list) { 181 if (!strcmp(mod->dump_file, filename) && 182 !strcmp(mod->name, modname)) 183 return mod; 184 } 185 return NULL; 186 } 187 188 static struct module *new_module(const char *name, size_t namelen) 189 { 190 struct module *mod; 191 192 mod = xmalloc(sizeof(*mod) + namelen + 1); 193 memset(mod, 0, sizeof(*mod)); 194 195 INIT_LIST_HEAD(&mod->exported_symbols); 196 INIT_LIST_HEAD(&mod->unresolved_symbols); 197 INIT_LIST_HEAD(&mod->missing_namespaces); 198 INIT_LIST_HEAD(&mod->imported_namespaces); 199 INIT_LIST_HEAD(&mod->aliases); 200 201 memcpy(mod->name, name, namelen); 202 mod->name[namelen] = '\0'; 203 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0); 204 205 /* 206 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE() 207 * is missing, do not check the use for EXPORT_SYMBOL_GPL() because 208 * modpost will exit with an error anyway. 209 */ 210 mod->is_gpl_compatible = true; 211 212 list_add_tail(&mod->list, &modules); 213 214 return mod; 215 } 216 217 struct symbol { 218 struct hlist_node hnode;/* link to hash table */ 219 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */ 220 struct module *module; 221 char *namespace; 222 unsigned int crc; 223 bool crc_valid; 224 bool weak; 225 bool is_func; 226 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ 227 bool used; /* there exists a user of this symbol */ 228 char name[]; 229 }; 230 231 static HASHTABLE_DEFINE(symbol_hashtable, 1U << 10); 232 233 /** 234 * Allocate a new symbols for use in the hash of exported symbols or 235 * the list of unresolved symbols per module 236 **/ 237 static struct symbol *alloc_symbol(const char *name) 238 { 239 struct symbol *s = xmalloc(sizeof(*s) + strlen(name) + 1); 240 241 memset(s, 0, sizeof(*s)); 242 strcpy(s->name, name); 243 244 return s; 245 } 246 247 /* For the hash of exported symbols */ 248 static void hash_add_symbol(struct symbol *sym) 249 { 250 hash_add(symbol_hashtable, &sym->hnode, hash_str(sym->name)); 251 } 252 253 static void sym_add_unresolved(const char *name, struct module *mod, bool weak) 254 { 255 struct symbol *sym; 256 257 sym = alloc_symbol(name); 258 sym->weak = weak; 259 260 list_add_tail(&sym->list, &mod->unresolved_symbols); 261 } 262 263 static struct symbol *sym_find_with_module(const char *name, struct module *mod) 264 { 265 struct symbol *s; 266 267 /* For our purposes, .foo matches foo. PPC64 needs this. */ 268 if (name[0] == '.') 269 name++; 270 271 hash_for_each_possible(symbol_hashtable, s, hnode, hash_str(name)) { 272 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) 273 return s; 274 } 275 return NULL; 276 } 277 278 static struct symbol *find_symbol(const char *name) 279 { 280 return sym_find_with_module(name, NULL); 281 } 282 283 struct namespace_list { 284 struct list_head list; 285 char namespace[]; 286 }; 287 288 static bool contains_namespace(struct list_head *head, const char *namespace) 289 { 290 struct namespace_list *list; 291 292 /* 293 * The default namespace is null string "", which is always implicitly 294 * contained. 295 */ 296 if (!namespace[0]) 297 return true; 298 299 list_for_each_entry(list, head, list) { 300 if (!strcmp(list->namespace, namespace)) 301 return true; 302 } 303 304 return false; 305 } 306 307 static void add_namespace(struct list_head *head, const char *namespace) 308 { 309 struct namespace_list *ns_entry; 310 311 if (!contains_namespace(head, namespace)) { 312 ns_entry = xmalloc(sizeof(*ns_entry) + strlen(namespace) + 1); 313 strcpy(ns_entry->namespace, namespace); 314 list_add_tail(&ns_entry->list, head); 315 } 316 } 317 318 static void *sym_get_data_by_offset(const struct elf_info *info, 319 unsigned int secindex, unsigned long offset) 320 { 321 Elf_Shdr *sechdr = &info->sechdrs[secindex]; 322 323 return (void *)info->hdr + sechdr->sh_offset + offset; 324 } 325 326 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) 327 { 328 return sym_get_data_by_offset(info, get_secindex(info, sym), 329 sym->st_value); 330 } 331 332 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) 333 { 334 return sym_get_data_by_offset(info, info->secindex_strings, 335 sechdr->sh_name); 336 } 337 338 static const char *sec_name(const struct elf_info *info, unsigned int secindex) 339 { 340 /* 341 * If sym->st_shndx is a special section index, there is no 342 * corresponding section header. 343 * Return "" if the index is out of range of info->sechdrs[] array. 344 */ 345 if (secindex >= info->num_sections) 346 return ""; 347 348 return sech_name(info, &info->sechdrs[secindex]); 349 } 350 351 static struct symbol *sym_add_exported(const char *name, struct module *mod, 352 bool gpl_only, const char *namespace) 353 { 354 struct symbol *s = find_symbol(name); 355 356 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { 357 error("%s: '%s' exported twice. Previous export was in %s%s\n", 358 mod->name, name, s->module->name, 359 s->module->is_vmlinux ? "" : ".ko"); 360 } 361 362 s = alloc_symbol(name); 363 s->module = mod; 364 s->is_gpl_only = gpl_only; 365 s->namespace = xstrdup(namespace); 366 list_add_tail(&s->list, &mod->exported_symbols); 367 hash_add_symbol(s); 368 369 return s; 370 } 371 372 static void sym_set_crc(struct symbol *sym, unsigned int crc) 373 { 374 sym->crc = crc; 375 sym->crc_valid = true; 376 } 377 378 static void *grab_file(const char *filename, size_t *size) 379 { 380 struct stat st; 381 void *map = MAP_FAILED; 382 int fd; 383 384 fd = open(filename, O_RDONLY); 385 if (fd < 0) 386 return NULL; 387 if (fstat(fd, &st)) 388 goto failed; 389 390 *size = st.st_size; 391 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 392 393 failed: 394 close(fd); 395 if (map == MAP_FAILED) 396 return NULL; 397 return map; 398 } 399 400 static void release_file(void *file, size_t size) 401 { 402 munmap(file, size); 403 } 404 405 static int parse_elf(struct elf_info *info, const char *filename) 406 { 407 unsigned int i; 408 Elf_Ehdr *hdr; 409 Elf_Shdr *sechdrs; 410 Elf_Sym *sym; 411 const char *secstrings; 412 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 413 414 hdr = grab_file(filename, &info->size); 415 if (!hdr) { 416 if (ignore_missing_files) { 417 fprintf(stderr, "%s: %s (ignored)\n", filename, 418 strerror(errno)); 419 return 0; 420 } 421 perror(filename); 422 exit(1); 423 } 424 info->hdr = hdr; 425 if (info->size < sizeof(*hdr)) { 426 /* file too small, assume this is an empty .o file */ 427 return 0; 428 } 429 /* Is this a valid ELF file? */ 430 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 431 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 432 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 433 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 434 /* Not an ELF file - silently ignore it */ 435 return 0; 436 } 437 438 switch (hdr->e_ident[EI_DATA]) { 439 case ELFDATA2LSB: 440 target_is_big_endian = false; 441 break; 442 case ELFDATA2MSB: 443 target_is_big_endian = true; 444 break; 445 default: 446 fatal("target endian is unknown\n"); 447 } 448 449 /* Fix endianness in ELF header */ 450 hdr->e_type = TO_NATIVE(hdr->e_type); 451 hdr->e_machine = TO_NATIVE(hdr->e_machine); 452 hdr->e_version = TO_NATIVE(hdr->e_version); 453 hdr->e_entry = TO_NATIVE(hdr->e_entry); 454 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 455 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 456 hdr->e_flags = TO_NATIVE(hdr->e_flags); 457 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 458 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 459 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 460 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 461 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 462 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 463 sechdrs = (void *)hdr + hdr->e_shoff; 464 info->sechdrs = sechdrs; 465 466 /* modpost only works for relocatable objects */ 467 if (hdr->e_type != ET_REL) 468 fatal("%s: not relocatable object.", filename); 469 470 /* Check if file offset is correct */ 471 if (hdr->e_shoff > info->size) 472 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", 473 (unsigned long)hdr->e_shoff, filename, info->size); 474 475 if (hdr->e_shnum == SHN_UNDEF) { 476 /* 477 * There are more than 64k sections, 478 * read count from .sh_size. 479 */ 480 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 481 } 482 else { 483 info->num_sections = hdr->e_shnum; 484 } 485 if (hdr->e_shstrndx == SHN_XINDEX) { 486 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 487 } 488 else { 489 info->secindex_strings = hdr->e_shstrndx; 490 } 491 492 /* Fix endianness in section headers */ 493 for (i = 0; i < info->num_sections; i++) { 494 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 495 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 496 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 497 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 498 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 499 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 500 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 501 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 502 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 503 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 504 } 505 /* Find symbol table. */ 506 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 507 for (i = 1; i < info->num_sections; i++) { 508 const char *secname; 509 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 510 511 if (!nobits && sechdrs[i].sh_offset > info->size) 512 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n", 513 filename, (unsigned long)sechdrs[i].sh_offset, 514 sizeof(*hdr)); 515 516 secname = secstrings + sechdrs[i].sh_name; 517 if (strcmp(secname, ".modinfo") == 0) { 518 if (nobits) 519 fatal("%s has NOBITS .modinfo\n", filename); 520 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 521 info->modinfo_len = sechdrs[i].sh_size; 522 } else if (!strcmp(secname, ".export_symbol")) { 523 info->export_symbol_secndx = i; 524 } else if (!strcmp(secname, ".no_trim_symbol")) { 525 info->no_trim_symbol = (void *)hdr + sechdrs[i].sh_offset; 526 info->no_trim_symbol_len = sechdrs[i].sh_size; 527 } 528 529 if (sechdrs[i].sh_type == SHT_SYMTAB) { 530 unsigned int sh_link_idx; 531 symtab_idx = i; 532 info->symtab_start = (void *)hdr + 533 sechdrs[i].sh_offset; 534 info->symtab_stop = (void *)hdr + 535 sechdrs[i].sh_offset + sechdrs[i].sh_size; 536 sh_link_idx = sechdrs[i].sh_link; 537 info->strtab = (void *)hdr + 538 sechdrs[sh_link_idx].sh_offset; 539 } 540 541 /* 32bit section no. table? ("more than 64k sections") */ 542 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 543 symtab_shndx_idx = i; 544 info->symtab_shndx_start = (void *)hdr + 545 sechdrs[i].sh_offset; 546 info->symtab_shndx_stop = (void *)hdr + 547 sechdrs[i].sh_offset + sechdrs[i].sh_size; 548 } 549 } 550 if (!info->symtab_start) 551 fatal("%s has no symtab?\n", filename); 552 553 /* Fix endianness in symbols */ 554 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 555 sym->st_shndx = TO_NATIVE(sym->st_shndx); 556 sym->st_name = TO_NATIVE(sym->st_name); 557 sym->st_value = TO_NATIVE(sym->st_value); 558 sym->st_size = TO_NATIVE(sym->st_size); 559 } 560 561 if (symtab_shndx_idx != ~0U) { 562 Elf32_Word *p; 563 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 564 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 565 filename, sechdrs[symtab_shndx_idx].sh_link, 566 symtab_idx); 567 /* Fix endianness */ 568 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 569 p++) 570 *p = TO_NATIVE(*p); 571 } 572 573 symsearch_init(info); 574 575 return 1; 576 } 577 578 static void parse_elf_finish(struct elf_info *info) 579 { 580 symsearch_finish(info); 581 release_file(info->hdr, info->size); 582 } 583 584 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 585 { 586 /* ignore __this_module, it will be resolved shortly */ 587 if (strcmp(symname, "__this_module") == 0) 588 return 1; 589 /* ignore global offset table */ 590 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 591 return 1; 592 if (info->hdr->e_machine == EM_PPC) 593 /* Special register function linked on all modules during final link of .ko */ 594 if (strstarts(symname, "_restgpr_") || 595 strstarts(symname, "_savegpr_") || 596 strstarts(symname, "_rest32gpr_") || 597 strstarts(symname, "_save32gpr_") || 598 strstarts(symname, "_restvr_") || 599 strstarts(symname, "_savevr_")) 600 return 1; 601 if (info->hdr->e_machine == EM_PPC64) 602 /* Special register function linked on all modules during final link of .ko */ 603 if (strstarts(symname, "_restgpr0_") || 604 strstarts(symname, "_savegpr0_") || 605 strstarts(symname, "_restvr_") || 606 strstarts(symname, "_savevr_") || 607 strcmp(symname, ".TOC.") == 0) 608 return 1; 609 610 /* ignore linker-created section bounds variables */ 611 if (strstarts(symname, "__start_") || strstarts(symname, "__stop_")) 612 return 1; 613 614 /* Do not ignore this symbol */ 615 return 0; 616 } 617 618 static void handle_symbol(struct module *mod, struct elf_info *info, 619 const Elf_Sym *sym, const char *symname) 620 { 621 switch (sym->st_shndx) { 622 case SHN_COMMON: 623 if (strstarts(symname, "__gnu_lto_")) { 624 /* Should warn here, but modpost runs before the linker */ 625 } else 626 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 627 break; 628 case SHN_UNDEF: 629 /* undefined symbol */ 630 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 631 ELF_ST_BIND(sym->st_info) != STB_WEAK) 632 break; 633 if (ignore_undef_symbol(info, symname)) 634 break; 635 if (info->hdr->e_machine == EM_SPARC || 636 info->hdr->e_machine == EM_SPARCV9) { 637 /* Ignore register directives. */ 638 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 639 break; 640 if (symname[0] == '.') { 641 char *munged = xstrdup(symname); 642 munged[0] = '_'; 643 munged[1] = toupper(munged[1]); 644 symname = munged; 645 } 646 } 647 648 sym_add_unresolved(symname, mod, 649 ELF_ST_BIND(sym->st_info) == STB_WEAK); 650 break; 651 default: 652 if (strcmp(symname, "init_module") == 0) 653 mod->has_init = true; 654 if (strcmp(symname, "cleanup_module") == 0) 655 mod->has_cleanup = true; 656 break; 657 } 658 } 659 660 /** 661 * Parse tag=value strings from .modinfo section 662 **/ 663 static char *next_string(char *string, unsigned long *secsize) 664 { 665 /* Skip non-zero chars */ 666 while (string[0]) { 667 string++; 668 if ((*secsize)-- <= 1) 669 return NULL; 670 } 671 672 /* Skip any zero padding. */ 673 while (!string[0]) { 674 string++; 675 if ((*secsize)-- <= 1) 676 return NULL; 677 } 678 return string; 679 } 680 681 static char *get_next_modinfo(struct elf_info *info, const char *tag, 682 char *prev) 683 { 684 char *p; 685 unsigned int taglen = strlen(tag); 686 char *modinfo = info->modinfo; 687 unsigned long size = info->modinfo_len; 688 689 if (prev) { 690 size -= prev - modinfo; 691 modinfo = next_string(prev, &size); 692 } 693 694 for (p = modinfo; p; p = next_string(p, &size)) { 695 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 696 return p + taglen + 1; 697 } 698 return NULL; 699 } 700 701 static char *get_modinfo(struct elf_info *info, const char *tag) 702 703 { 704 return get_next_modinfo(info, tag, NULL); 705 } 706 707 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 708 { 709 return sym ? elf->strtab + sym->st_name : ""; 710 } 711 712 /* 713 * Check whether the 'string' argument matches one of the 'patterns', 714 * an array of shell wildcard patterns (glob). 715 * 716 * Return true is there is a match. 717 */ 718 static bool match(const char *string, const char *const patterns[]) 719 { 720 const char *pattern; 721 722 while ((pattern = *patterns++)) { 723 if (!fnmatch(pattern, string, 0)) 724 return true; 725 } 726 727 return false; 728 } 729 730 /* useful to pass patterns to match() directly */ 731 #define PATTERNS(...) \ 732 ({ \ 733 static const char *const patterns[] = {__VA_ARGS__, NULL}; \ 734 patterns; \ 735 }) 736 737 /* sections that we do not want to do full section mismatch check on */ 738 static const char *const section_white_list[] = 739 { 740 ".comment*", 741 ".debug*", 742 ".zdebug*", /* Compressed debug sections. */ 743 ".GCC.command.line", /* record-gcc-switches */ 744 ".mdebug*", /* alpha, score, mips etc. */ 745 ".pdr", /* alpha, score, mips etc. */ 746 ".stab*", 747 ".note*", 748 ".got*", 749 ".toc*", 750 ".xt.prop", /* xtensa */ 751 ".xt.lit", /* xtensa */ 752 ".arcextmap*", /* arc */ 753 ".gnu.linkonce.arcext*", /* arc : modules */ 754 ".cmem*", /* EZchip */ 755 ".fmt_slot*", /* EZchip */ 756 ".gnu.lto*", 757 ".discard.*", 758 ".llvm.call-graph-profile", /* call graph */ 759 NULL 760 }; 761 762 /* 763 * This is used to find sections missing the SHF_ALLOC flag. 764 * The cause of this is often a section specified in assembler 765 * without "ax" / "aw". 766 */ 767 static void check_section(const char *modname, struct elf_info *elf, 768 Elf_Shdr *sechdr) 769 { 770 const char *sec = sech_name(elf, sechdr); 771 772 if (sechdr->sh_type == SHT_PROGBITS && 773 !(sechdr->sh_flags & SHF_ALLOC) && 774 !match(sec, section_white_list)) { 775 warn("%s (%s): unexpected non-allocatable section.\n" 776 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 777 "Note that for example <linux/init.h> contains\n" 778 "section definitions for use in .S files.\n\n", 779 modname, sec); 780 } 781 } 782 783 784 785 #define ALL_INIT_DATA_SECTIONS \ 786 ".init.setup", ".init.rodata", ".init.data" 787 788 #define ALL_PCI_INIT_SECTIONS \ 789 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 790 ".pci_fixup_enable", ".pci_fixup_resume", \ 791 ".pci_fixup_resume_early", ".pci_fixup_suspend" 792 793 #define ALL_INIT_SECTIONS ".init.*" 794 #define ALL_EXIT_SECTIONS ".exit.*" 795 796 #define DATA_SECTIONS ".data", ".data.rel" 797 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ 798 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \ 799 ".ltext", ".ltext.*" 800 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ 801 ".fixup", ".entry.text", ".exception.text", \ 802 ".coldtext", ".softirqentry.text", ".irqentry.text" 803 804 #define ALL_TEXT_SECTIONS ".init.text", ".exit.text", \ 805 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 806 807 enum mismatch { 808 TEXTDATA_TO_ANY_INIT_EXIT, 809 XXXINIT_TO_SOME_INIT, 810 ANY_INIT_TO_ANY_EXIT, 811 ANY_EXIT_TO_ANY_INIT, 812 EXTABLE_TO_NON_TEXT, 813 }; 814 815 /** 816 * Describe how to match sections on different criteria: 817 * 818 * @fromsec: Array of sections to be matched. 819 * 820 * @bad_tosec: Relocations applied to a section in @fromsec to a section in 821 * this array is forbidden (black-list). Can be empty. 822 * 823 * @good_tosec: Relocations applied to a section in @fromsec must be 824 * targeting sections in this array (white-list). Can be empty. 825 * 826 * @mismatch: Type of mismatch. 827 */ 828 struct sectioncheck { 829 const char *fromsec[20]; 830 const char *bad_tosec[20]; 831 const char *good_tosec[20]; 832 enum mismatch mismatch; 833 }; 834 835 static const struct sectioncheck sectioncheck[] = { 836 /* Do not reference init/exit code/data from 837 * normal code and data 838 */ 839 { 840 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 841 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }, 842 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT, 843 }, 844 /* Do not use exit code/data from init code */ 845 { 846 .fromsec = { ALL_INIT_SECTIONS, NULL }, 847 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 848 .mismatch = ANY_INIT_TO_ANY_EXIT, 849 }, 850 /* Do not use init code/data from exit code */ 851 { 852 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 853 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 854 .mismatch = ANY_EXIT_TO_ANY_INIT, 855 }, 856 { 857 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 858 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 859 .mismatch = ANY_INIT_TO_ANY_EXIT, 860 }, 861 { 862 .fromsec = { "__ex_table", NULL }, 863 /* If you're adding any new black-listed sections in here, consider 864 * adding a special 'printer' for them in scripts/check_extable. 865 */ 866 .bad_tosec = { ".altinstr_replacement", NULL }, 867 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 868 .mismatch = EXTABLE_TO_NON_TEXT, 869 } 870 }; 871 872 static const struct sectioncheck *section_mismatch( 873 const char *fromsec, const char *tosec) 874 { 875 int i; 876 877 /* 878 * The target section could be the SHT_NUL section when we're 879 * handling relocations to un-resolved symbols, trying to match it 880 * doesn't make much sense and causes build failures on parisc 881 * architectures. 882 */ 883 if (*tosec == '\0') 884 return NULL; 885 886 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 887 const struct sectioncheck *check = §ioncheck[i]; 888 889 if (match(fromsec, check->fromsec)) { 890 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 891 return check; 892 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 893 return check; 894 } 895 } 896 return NULL; 897 } 898 899 /** 900 * Whitelist to allow certain references to pass with no warning. 901 * 902 * Pattern 1: 903 * If a module parameter is declared __initdata and permissions=0 904 * then this is legal despite the warning generated. 905 * We cannot see value of permissions here, so just ignore 906 * this pattern. 907 * The pattern is identified by: 908 * tosec = .init.data 909 * fromsec = .data* 910 * atsym =__param* 911 * 912 * Pattern 1a: 913 * module_param_call() ops can refer to __init set function if permissions=0 914 * The pattern is identified by: 915 * tosec = .init.text 916 * fromsec = .data* 917 * atsym = __param_ops_* 918 * 919 * Pattern 3: 920 * Whitelist all references from .head.text to any init section 921 * 922 * Pattern 4: 923 * Some symbols belong to init section but still it is ok to reference 924 * these from non-init sections as these symbols don't have any memory 925 * allocated for them and symbol address and value are same. So even 926 * if init section is freed, its ok to reference those symbols. 927 * For ex. symbols marking the init section boundaries. 928 * This pattern is identified by 929 * refsymname = __init_begin, _sinittext, _einittext 930 * 931 * Pattern 5: 932 * GCC may optimize static inlines when fed constant arg(s) resulting 933 * in functions like cpumask_empty() -- generating an associated symbol 934 * cpumask_empty.constprop.3 that appears in the audit. If the const that 935 * is passed in comes from __init, like say nmi_ipi_mask, we get a 936 * meaningless section warning. May need to add isra symbols too... 937 * This pattern is identified by 938 * tosec = init section 939 * fromsec = text section 940 * refsymname = *.constprop.* 941 * 942 **/ 943 static int secref_whitelist(const char *fromsec, const char *fromsym, 944 const char *tosec, const char *tosym) 945 { 946 /* Check for pattern 1 */ 947 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 948 match(fromsec, PATTERNS(DATA_SECTIONS)) && 949 strstarts(fromsym, "__param")) 950 return 0; 951 952 /* Check for pattern 1a */ 953 if (strcmp(tosec, ".init.text") == 0 && 954 match(fromsec, PATTERNS(DATA_SECTIONS)) && 955 strstarts(fromsym, "__param_ops_")) 956 return 0; 957 958 /* symbols in data sections that may refer to any init/exit sections */ 959 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 960 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 961 match(fromsym, PATTERNS("*_ops", "*_probe", "*_console"))) 962 return 0; 963 964 /* Check for pattern 3 */ 965 if (strstarts(fromsec, ".head.text") && 966 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 967 return 0; 968 969 /* Check for pattern 4 */ 970 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 971 return 0; 972 973 /* Check for pattern 5 */ 974 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 975 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 976 match(fromsym, PATTERNS("*.constprop.*"))) 977 return 0; 978 979 return 1; 980 } 981 982 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 983 unsigned int secndx) 984 { 985 return symsearch_find_nearest(elf, addr, secndx, false, ~0); 986 } 987 988 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 989 { 990 Elf_Sym *new_sym; 991 992 /* If the supplied symbol has a valid name, return it */ 993 if (is_valid_name(elf, sym)) 994 return sym; 995 996 /* 997 * Strive to find a better symbol name, but the resulting name may not 998 * match the symbol referenced in the original code. 999 */ 1000 new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym), 1001 true, 20); 1002 return new_sym ? new_sym : sym; 1003 } 1004 1005 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1006 { 1007 if (secndx >= elf->num_sections) 1008 return false; 1009 1010 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1011 } 1012 1013 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1014 const struct sectioncheck* const mismatch, 1015 Elf_Sym *tsym, 1016 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1017 const char *tosec, Elf_Addr taddr) 1018 { 1019 Elf_Sym *from; 1020 const char *tosym; 1021 const char *fromsym; 1022 char taddr_str[16]; 1023 1024 from = find_fromsym(elf, faddr, fsecndx); 1025 fromsym = sym_name(elf, from); 1026 1027 tsym = find_tosym(elf, taddr, tsym); 1028 tosym = sym_name(elf, tsym); 1029 1030 /* check whitelist - we may ignore it */ 1031 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1032 return; 1033 1034 sec_mismatch_count++; 1035 1036 if (!tosym[0]) 1037 snprintf(taddr_str, sizeof(taddr_str), "0x%x", (unsigned int)taddr); 1038 1039 /* 1040 * The format for the reference source: <symbol_name>+<offset> or <address> 1041 * The format for the reference destination: <symbol_name> or <address> 1042 */ 1043 warn("%s: section mismatch in reference: %s%s0x%x (section: %s) -> %s (section: %s)\n", 1044 modname, fromsym, fromsym[0] ? "+" : "", 1045 (unsigned int)(faddr - (fromsym[0] ? from->st_value : 0)), 1046 fromsec, tosym[0] ? tosym : taddr_str, tosec); 1047 1048 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1049 if (match(tosec, mismatch->bad_tosec)) 1050 fatal("The relocation at %s+0x%lx references\n" 1051 "section \"%s\" which is black-listed.\n" 1052 "Something is seriously wrong and should be fixed.\n" 1053 "You might get more information about where this is\n" 1054 "coming from by using scripts/check_extable.sh %s\n", 1055 fromsec, (long)faddr, tosec, modname); 1056 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1057 warn("The relocation at %s+0x%lx references\n" 1058 "section \"%s\" which is not in the list of\n" 1059 "authorized sections. If you're adding a new section\n" 1060 "and/or if this reference is valid, add \"%s\" to the\n" 1061 "list of authorized sections to jump to on fault.\n" 1062 "This can be achieved by adding \"%s\" to\n" 1063 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1064 fromsec, (long)faddr, tosec, tosec, tosec); 1065 else 1066 error("%s+0x%lx references non-executable section '%s'\n", 1067 fromsec, (long)faddr, tosec); 1068 } 1069 } 1070 1071 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1072 Elf_Addr faddr, const char *secname, 1073 Elf_Sym *sym) 1074 { 1075 static const char *prefix = "__export_symbol_"; 1076 const char *label_name, *name, *data; 1077 Elf_Sym *label; 1078 struct symbol *s; 1079 bool is_gpl; 1080 1081 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1082 label_name = sym_name(elf, label); 1083 1084 if (!strstarts(label_name, prefix)) { 1085 error("%s: .export_symbol section contains strange symbol '%s'\n", 1086 mod->name, label_name); 1087 return; 1088 } 1089 1090 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1091 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1092 error("%s: local symbol '%s' was exported\n", mod->name, 1093 label_name + strlen(prefix)); 1094 return; 1095 } 1096 1097 name = sym_name(elf, sym); 1098 if (strcmp(label_name + strlen(prefix), name)) { 1099 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1100 mod->name, name); 1101 return; 1102 } 1103 1104 data = sym_get_data(elf, label); /* license */ 1105 if (!strcmp(data, "GPL")) { 1106 is_gpl = true; 1107 } else if (!strcmp(data, "")) { 1108 is_gpl = false; 1109 } else { 1110 error("%s: unknown license '%s' was specified for '%s'\n", 1111 mod->name, data, name); 1112 return; 1113 } 1114 1115 data += strlen(data) + 1; /* namespace */ 1116 s = sym_add_exported(name, mod, is_gpl, data); 1117 1118 /* 1119 * We need to be aware whether we are exporting a function or 1120 * a data on some architectures. 1121 */ 1122 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1123 1124 /* 1125 * For parisc64, symbols prefixed $$ from the library have the symbol type 1126 * STT_LOPROC. They should be handled as functions too. 1127 */ 1128 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1129 elf->hdr->e_machine == EM_PARISC && 1130 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1131 s->is_func = true; 1132 1133 if (match(secname, PATTERNS(ALL_INIT_SECTIONS))) 1134 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1135 mod->name, name); 1136 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS))) 1137 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1138 mod->name, name); 1139 } 1140 1141 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1142 Elf_Sym *sym, 1143 unsigned int fsecndx, const char *fromsec, 1144 Elf_Addr faddr, Elf_Addr taddr) 1145 { 1146 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1147 const struct sectioncheck *mismatch; 1148 1149 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1150 check_export_symbol(mod, elf, faddr, tosec, sym); 1151 return; 1152 } 1153 1154 mismatch = section_mismatch(fromsec, tosec); 1155 if (!mismatch) 1156 return; 1157 1158 default_mismatch_handler(mod->name, elf, mismatch, sym, 1159 fsecndx, fromsec, faddr, 1160 tosec, taddr); 1161 } 1162 1163 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1164 { 1165 switch (r_type) { 1166 case R_386_32: 1167 return get_unaligned_native(location); 1168 case R_386_PC32: 1169 return get_unaligned_native(location) + 4; 1170 } 1171 1172 return (Elf_Addr)(-1); 1173 } 1174 1175 static int32_t sign_extend32(int32_t value, int index) 1176 { 1177 uint8_t shift = 31 - index; 1178 1179 return (int32_t)(value << shift) >> shift; 1180 } 1181 1182 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1183 { 1184 uint32_t inst, upper, lower, sign, j1, j2; 1185 int32_t offset; 1186 1187 switch (r_type) { 1188 case R_ARM_ABS32: 1189 case R_ARM_REL32: 1190 inst = get_unaligned_native((uint32_t *)loc); 1191 return inst + sym->st_value; 1192 case R_ARM_MOVW_ABS_NC: 1193 case R_ARM_MOVT_ABS: 1194 inst = get_unaligned_native((uint32_t *)loc); 1195 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1196 15); 1197 return offset + sym->st_value; 1198 case R_ARM_PC24: 1199 case R_ARM_CALL: 1200 case R_ARM_JUMP24: 1201 inst = get_unaligned_native((uint32_t *)loc); 1202 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1203 return offset + sym->st_value + 8; 1204 case R_ARM_THM_MOVW_ABS_NC: 1205 case R_ARM_THM_MOVT_ABS: 1206 upper = get_unaligned_native((uint16_t *)loc); 1207 lower = get_unaligned_native((uint16_t *)loc + 1); 1208 offset = sign_extend32(((upper & 0x000f) << 12) | 1209 ((upper & 0x0400) << 1) | 1210 ((lower & 0x7000) >> 4) | 1211 (lower & 0x00ff), 1212 15); 1213 return offset + sym->st_value; 1214 case R_ARM_THM_JUMP19: 1215 /* 1216 * Encoding T3: 1217 * S = upper[10] 1218 * imm6 = upper[5:0] 1219 * J1 = lower[13] 1220 * J2 = lower[11] 1221 * imm11 = lower[10:0] 1222 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1223 */ 1224 upper = get_unaligned_native((uint16_t *)loc); 1225 lower = get_unaligned_native((uint16_t *)loc + 1); 1226 1227 sign = (upper >> 10) & 1; 1228 j1 = (lower >> 13) & 1; 1229 j2 = (lower >> 11) & 1; 1230 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1231 ((upper & 0x03f) << 12) | 1232 ((lower & 0x07ff) << 1), 1233 20); 1234 return offset + sym->st_value + 4; 1235 case R_ARM_THM_PC22: 1236 case R_ARM_THM_JUMP24: 1237 /* 1238 * Encoding T4: 1239 * S = upper[10] 1240 * imm10 = upper[9:0] 1241 * J1 = lower[13] 1242 * J2 = lower[11] 1243 * imm11 = lower[10:0] 1244 * I1 = NOT(J1 XOR S) 1245 * I2 = NOT(J2 XOR S) 1246 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1247 */ 1248 upper = get_unaligned_native((uint16_t *)loc); 1249 lower = get_unaligned_native((uint16_t *)loc + 1); 1250 1251 sign = (upper >> 10) & 1; 1252 j1 = (lower >> 13) & 1; 1253 j2 = (lower >> 11) & 1; 1254 offset = sign_extend32((sign << 24) | 1255 ((~(j1 ^ sign) & 1) << 23) | 1256 ((~(j2 ^ sign) & 1) << 22) | 1257 ((upper & 0x03ff) << 12) | 1258 ((lower & 0x07ff) << 1), 1259 24); 1260 return offset + sym->st_value + 4; 1261 } 1262 1263 return (Elf_Addr)(-1); 1264 } 1265 1266 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1267 { 1268 uint32_t inst; 1269 1270 inst = get_unaligned_native(location); 1271 switch (r_type) { 1272 case R_MIPS_LO16: 1273 return inst & 0xffff; 1274 case R_MIPS_26: 1275 return (inst & 0x03ffffff) << 2; 1276 case R_MIPS_32: 1277 return inst; 1278 } 1279 return (Elf_Addr)(-1); 1280 } 1281 1282 #ifndef EM_RISCV 1283 #define EM_RISCV 243 1284 #endif 1285 1286 #ifndef R_RISCV_SUB32 1287 #define R_RISCV_SUB32 39 1288 #endif 1289 1290 #ifndef EM_LOONGARCH 1291 #define EM_LOONGARCH 258 1292 #endif 1293 1294 #ifndef R_LARCH_SUB32 1295 #define R_LARCH_SUB32 55 1296 #endif 1297 1298 #ifndef R_LARCH_RELAX 1299 #define R_LARCH_RELAX 100 1300 #endif 1301 1302 #ifndef R_LARCH_ALIGN 1303 #define R_LARCH_ALIGN 102 1304 #endif 1305 1306 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1307 unsigned int *r_type, unsigned int *r_sym) 1308 { 1309 typedef struct { 1310 Elf64_Word r_sym; /* Symbol index */ 1311 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1312 unsigned char r_type3; /* 3rd relocation type */ 1313 unsigned char r_type2; /* 2nd relocation type */ 1314 unsigned char r_type; /* 1st relocation type */ 1315 } Elf64_Mips_R_Info; 1316 1317 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1318 1319 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1320 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1321 1322 *r_type = mips64_r_info->r_type; 1323 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1324 return; 1325 } 1326 1327 if (is_64bit) 1328 r_info = TO_NATIVE((Elf64_Xword)r_info); 1329 else 1330 r_info = TO_NATIVE((Elf32_Word)r_info); 1331 1332 *r_type = ELF_R_TYPE(r_info); 1333 *r_sym = ELF_R_SYM(r_info); 1334 } 1335 1336 static void section_rela(struct module *mod, struct elf_info *elf, 1337 unsigned int fsecndx, const char *fromsec, 1338 const Elf_Rela *start, const Elf_Rela *stop) 1339 { 1340 const Elf_Rela *rela; 1341 1342 for (rela = start; rela < stop; rela++) { 1343 Elf_Sym *tsym; 1344 Elf_Addr taddr, r_offset; 1345 unsigned int r_type, r_sym; 1346 1347 r_offset = TO_NATIVE(rela->r_offset); 1348 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1349 1350 tsym = elf->symtab_start + r_sym; 1351 taddr = tsym->st_value + TO_NATIVE(rela->r_addend); 1352 1353 switch (elf->hdr->e_machine) { 1354 case EM_RISCV: 1355 if (!strcmp("__ex_table", fromsec) && 1356 r_type == R_RISCV_SUB32) 1357 continue; 1358 break; 1359 case EM_LOONGARCH: 1360 switch (r_type) { 1361 case R_LARCH_SUB32: 1362 if (!strcmp("__ex_table", fromsec)) 1363 continue; 1364 break; 1365 case R_LARCH_RELAX: 1366 case R_LARCH_ALIGN: 1367 /* These relocs do not refer to symbols */ 1368 continue; 1369 } 1370 break; 1371 } 1372 1373 check_section_mismatch(mod, elf, tsym, 1374 fsecndx, fromsec, r_offset, taddr); 1375 } 1376 } 1377 1378 static void section_rel(struct module *mod, struct elf_info *elf, 1379 unsigned int fsecndx, const char *fromsec, 1380 const Elf_Rel *start, const Elf_Rel *stop) 1381 { 1382 const Elf_Rel *rel; 1383 1384 for (rel = start; rel < stop; rel++) { 1385 Elf_Sym *tsym; 1386 Elf_Addr taddr, r_offset; 1387 unsigned int r_type, r_sym; 1388 void *loc; 1389 1390 r_offset = TO_NATIVE(rel->r_offset); 1391 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1392 1393 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1394 tsym = elf->symtab_start + r_sym; 1395 1396 switch (elf->hdr->e_machine) { 1397 case EM_386: 1398 taddr = addend_386_rel(loc, r_type); 1399 break; 1400 case EM_ARM: 1401 taddr = addend_arm_rel(loc, tsym, r_type); 1402 break; 1403 case EM_MIPS: 1404 taddr = addend_mips_rel(loc, r_type); 1405 break; 1406 default: 1407 fatal("Please add code to calculate addend for this architecture\n"); 1408 } 1409 1410 check_section_mismatch(mod, elf, tsym, 1411 fsecndx, fromsec, r_offset, taddr); 1412 } 1413 } 1414 1415 /** 1416 * A module includes a number of sections that are discarded 1417 * either when loaded or when used as built-in. 1418 * For loaded modules all functions marked __init and all data 1419 * marked __initdata will be discarded when the module has been initialized. 1420 * Likewise for modules used built-in the sections marked __exit 1421 * are discarded because __exit marked function are supposed to be called 1422 * only when a module is unloaded which never happens for built-in modules. 1423 * The check_sec_ref() function traverses all relocation records 1424 * to find all references to a section that reference a section that will 1425 * be discarded and warns about it. 1426 **/ 1427 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1428 { 1429 int i; 1430 1431 /* Walk through all sections */ 1432 for (i = 0; i < elf->num_sections; i++) { 1433 Elf_Shdr *sechdr = &elf->sechdrs[i]; 1434 1435 check_section(mod->name, elf, sechdr); 1436 /* We want to process only relocation sections and not .init */ 1437 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) { 1438 /* section to which the relocation applies */ 1439 unsigned int secndx = sechdr->sh_info; 1440 const char *secname = sec_name(elf, secndx); 1441 const void *start, *stop; 1442 1443 /* If the section is known good, skip it */ 1444 if (match(secname, section_white_list)) 1445 continue; 1446 1447 start = sym_get_data_by_offset(elf, i, 0); 1448 stop = start + sechdr->sh_size; 1449 1450 if (sechdr->sh_type == SHT_RELA) 1451 section_rela(mod, elf, secndx, secname, 1452 start, stop); 1453 else 1454 section_rel(mod, elf, secndx, secname, 1455 start, stop); 1456 } 1457 } 1458 } 1459 1460 static char *remove_dot(char *s) 1461 { 1462 size_t n = strcspn(s, "."); 1463 1464 if (n && s[n]) { 1465 size_t m = strspn(s + n + 1, "0123456789"); 1466 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1467 s[n] = 0; 1468 } 1469 return s; 1470 } 1471 1472 /* 1473 * The CRCs are recorded in .*.cmd files in the form of: 1474 * #SYMVER <name> <crc> 1475 */ 1476 static void extract_crcs_for_object(const char *object, struct module *mod) 1477 { 1478 char cmd_file[PATH_MAX]; 1479 char *buf, *p; 1480 const char *base; 1481 int dirlen, ret; 1482 1483 base = get_basename(object); 1484 dirlen = base - object; 1485 1486 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1487 dirlen, object, base); 1488 if (ret >= sizeof(cmd_file)) { 1489 error("%s: too long path was truncated\n", cmd_file); 1490 return; 1491 } 1492 1493 buf = read_text_file(cmd_file); 1494 p = buf; 1495 1496 while ((p = strstr(p, "\n#SYMVER "))) { 1497 char *name; 1498 size_t namelen; 1499 unsigned int crc; 1500 struct symbol *sym; 1501 1502 name = p + strlen("\n#SYMVER "); 1503 1504 p = strchr(name, ' '); 1505 if (!p) 1506 break; 1507 1508 namelen = p - name; 1509 p++; 1510 1511 if (!isdigit(*p)) 1512 continue; /* skip this line */ 1513 1514 crc = strtoul(p, &p, 0); 1515 if (*p != '\n') 1516 continue; /* skip this line */ 1517 1518 name[namelen] = '\0'; 1519 1520 /* 1521 * sym_find_with_module() may return NULL here. 1522 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1523 * Since commit e1327a127703, genksyms calculates CRCs of all 1524 * symbols, including trimmed ones. Ignore orphan CRCs. 1525 */ 1526 sym = sym_find_with_module(name, mod); 1527 if (sym) 1528 sym_set_crc(sym, crc); 1529 } 1530 1531 free(buf); 1532 } 1533 1534 /* 1535 * The symbol versions (CRC) are recorded in the .*.cmd files. 1536 * Parse them to retrieve CRCs for the current module. 1537 */ 1538 static void mod_set_crcs(struct module *mod) 1539 { 1540 char objlist[PATH_MAX]; 1541 char *buf, *p, *obj; 1542 int ret; 1543 1544 if (mod->is_vmlinux) { 1545 strcpy(objlist, ".vmlinux.objs"); 1546 } else { 1547 /* objects for a module are listed in the *.mod file. */ 1548 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1549 if (ret >= sizeof(objlist)) { 1550 error("%s: too long path was truncated\n", objlist); 1551 return; 1552 } 1553 } 1554 1555 buf = read_text_file(objlist); 1556 p = buf; 1557 1558 while ((obj = strsep(&p, "\n")) && obj[0]) 1559 extract_crcs_for_object(obj, mod); 1560 1561 free(buf); 1562 } 1563 1564 static void read_symbols(const char *modname) 1565 { 1566 const char *symname; 1567 char *version; 1568 char *license; 1569 char *namespace; 1570 struct module *mod; 1571 struct elf_info info = { }; 1572 Elf_Sym *sym; 1573 1574 if (!parse_elf(&info, modname)) 1575 return; 1576 1577 if (!strends(modname, ".o")) { 1578 error("%s: filename must be suffixed with .o\n", modname); 1579 return; 1580 } 1581 1582 /* strip trailing .o */ 1583 mod = new_module(modname, strlen(modname) - strlen(".o")); 1584 1585 /* save .no_trim_symbol section for later use */ 1586 if (info.no_trim_symbol_len) { 1587 mod->no_trim_symbol = xmalloc(info.no_trim_symbol_len); 1588 memcpy(mod->no_trim_symbol, info.no_trim_symbol, 1589 info.no_trim_symbol_len); 1590 mod->no_trim_symbol_len = info.no_trim_symbol_len; 1591 } 1592 1593 if (!mod->is_vmlinux) { 1594 license = get_modinfo(&info, "license"); 1595 if (!license) 1596 error("missing MODULE_LICENSE() in %s\n", modname); 1597 while (license) { 1598 if (!license_is_gpl_compatible(license)) { 1599 mod->is_gpl_compatible = false; 1600 break; 1601 } 1602 license = get_next_modinfo(&info, "license", license); 1603 } 1604 1605 for (namespace = get_modinfo(&info, "import_ns"); 1606 namespace; 1607 namespace = get_next_modinfo(&info, "import_ns", namespace)) { 1608 if (strstarts(namespace, MODULE_NS_PREFIX)) 1609 error("%s: explicitly importing namespace \"%s\" is not allowed.\n", 1610 mod->name, namespace); 1611 1612 add_namespace(&mod->imported_namespaces, namespace); 1613 } 1614 1615 if (!get_modinfo(&info, "description")) 1616 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1617 } 1618 1619 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1620 symname = remove_dot(info.strtab + sym->st_name); 1621 1622 handle_symbol(mod, &info, sym, symname); 1623 handle_moddevtable(mod, &info, sym, symname); 1624 } 1625 1626 check_sec_ref(mod, &info); 1627 1628 if (!mod->is_vmlinux) { 1629 version = get_modinfo(&info, "version"); 1630 if (version || all_versions) 1631 get_src_version(mod->name, mod->srcversion, 1632 sizeof(mod->srcversion) - 1); 1633 } 1634 1635 parse_elf_finish(&info); 1636 1637 if (modversions) { 1638 /* 1639 * Our trick to get versioning for module struct etc. - it's 1640 * never passed as an argument to an exported function, so 1641 * the automatic versioning doesn't pick it up, but it's really 1642 * important anyhow. 1643 */ 1644 sym_add_unresolved("module_layout", mod, false); 1645 1646 mod_set_crcs(mod); 1647 } 1648 } 1649 1650 static void read_symbols_from_files(const char *filename) 1651 { 1652 FILE *in = stdin; 1653 char fname[PATH_MAX]; 1654 1655 in = fopen(filename, "r"); 1656 if (!in) 1657 fatal("Can't open filenames file %s: %m", filename); 1658 1659 while (fgets(fname, PATH_MAX, in) != NULL) { 1660 if (strends(fname, "\n")) 1661 fname[strlen(fname)-1] = '\0'; 1662 read_symbols(fname); 1663 } 1664 1665 fclose(in); 1666 } 1667 1668 #define SZ 500 1669 1670 /* We first write the generated file into memory using the 1671 * following helper, then compare to the file on disk and 1672 * only update the later if anything changed */ 1673 1674 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1675 const char *fmt, ...) 1676 { 1677 char tmp[SZ]; 1678 int len; 1679 va_list ap; 1680 1681 va_start(ap, fmt); 1682 len = vsnprintf(tmp, SZ, fmt, ap); 1683 buf_write(buf, tmp, len); 1684 va_end(ap); 1685 } 1686 1687 void buf_write(struct buffer *buf, const char *s, int len) 1688 { 1689 if (buf->size - buf->pos < len) { 1690 buf->size += len + SZ; 1691 buf->p = xrealloc(buf->p, buf->size); 1692 } 1693 strncpy(buf->p + buf->pos, s, len); 1694 buf->pos += len; 1695 } 1696 1697 /** 1698 * verify_module_namespace() - does @modname have access to this symbol's @namespace 1699 * @namespace: export symbol namespace 1700 * @modname: module name 1701 * 1702 * If @namespace is prefixed with "module:" to indicate it is a module namespace 1703 * then test if @modname matches any of the comma separated patterns. 1704 * 1705 * The patterns only support tail-glob. 1706 */ 1707 static bool verify_module_namespace(const char *namespace, const char *modname) 1708 { 1709 size_t len, modlen = strlen(modname); 1710 const char *prefix = "module:"; 1711 const char *sep; 1712 bool glob; 1713 1714 if (!strstarts(namespace, prefix)) 1715 return false; 1716 1717 for (namespace += strlen(prefix); *namespace; namespace = sep) { 1718 sep = strchrnul(namespace, ','); 1719 len = sep - namespace; 1720 1721 glob = false; 1722 if (sep[-1] == '*') { 1723 len--; 1724 glob = true; 1725 } 1726 1727 if (*sep) 1728 sep++; 1729 1730 if (strncmp(namespace, modname, len) == 0 && (glob || len == modlen)) 1731 return true; 1732 } 1733 1734 return false; 1735 } 1736 1737 static void check_exports(struct module *mod) 1738 { 1739 struct symbol *s, *exp; 1740 1741 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1742 const char *basename; 1743 exp = find_symbol(s->name); 1744 if (!exp) { 1745 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1746 modpost_log(!warn_unresolved, 1747 "\"%s\" [%s.ko] undefined!\n", 1748 s->name, mod->name); 1749 continue; 1750 } 1751 if (exp->module == mod) { 1752 error("\"%s\" [%s.ko] was exported without definition\n", 1753 s->name, mod->name); 1754 continue; 1755 } 1756 1757 exp->used = true; 1758 s->module = exp->module; 1759 s->crc_valid = exp->crc_valid; 1760 s->crc = exp->crc; 1761 1762 basename = get_basename(mod->name); 1763 1764 if (!verify_module_namespace(exp->namespace, basename) && 1765 !contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1766 modpost_log(!allow_missing_ns_imports, 1767 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1768 basename, exp->name, exp->namespace); 1769 add_namespace(&mod->missing_namespaces, exp->namespace); 1770 } 1771 1772 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1773 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1774 basename, exp->name); 1775 } 1776 } 1777 1778 static void handle_white_list_exports(const char *white_list) 1779 { 1780 char *buf, *p, *name; 1781 1782 buf = read_text_file(white_list); 1783 p = buf; 1784 1785 while ((name = strsep(&p, "\n"))) { 1786 struct symbol *sym = find_symbol(name); 1787 1788 if (sym) 1789 sym->used = true; 1790 } 1791 1792 free(buf); 1793 } 1794 1795 /* 1796 * Keep symbols recorded in the .no_trim_symbol section. This is necessary to 1797 * prevent CONFIG_TRIM_UNUSED_KSYMS from dropping EXPORT_SYMBOL because 1798 * symbol_get() relies on the symbol being present in the ksymtab for lookups. 1799 */ 1800 static void keep_no_trim_symbols(struct module *mod) 1801 { 1802 unsigned long size = mod->no_trim_symbol_len; 1803 1804 for (char *s = mod->no_trim_symbol; s; s = next_string(s , &size)) { 1805 struct symbol *sym; 1806 1807 /* 1808 * If find_symbol() returns NULL, this symbol is not provided 1809 * by any module, and symbol_get() will fail. 1810 */ 1811 sym = find_symbol(s); 1812 if (sym) 1813 sym->used = true; 1814 } 1815 } 1816 1817 static void check_modname_len(struct module *mod) 1818 { 1819 const char *mod_name; 1820 1821 mod_name = get_basename(mod->name); 1822 1823 if (strlen(mod_name) >= MODULE_NAME_LEN) 1824 error("module name is too long [%s.ko]\n", mod->name); 1825 } 1826 1827 /** 1828 * Header for the generated file 1829 **/ 1830 static void add_header(struct buffer *b, struct module *mod) 1831 { 1832 buf_printf(b, "#include <linux/module.h>\n"); 1833 buf_printf(b, "#include <linux/export-internal.h>\n"); 1834 buf_printf(b, "#include <linux/compiler.h>\n"); 1835 buf_printf(b, "\n"); 1836 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1837 buf_printf(b, "\n"); 1838 buf_printf(b, "__visible struct module __this_module\n"); 1839 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1840 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1841 if (mod->has_init) 1842 buf_printf(b, "\t.init = init_module,\n"); 1843 if (mod->has_cleanup) 1844 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1845 "\t.exit = cleanup_module,\n" 1846 "#endif\n"); 1847 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1848 buf_printf(b, "};\n"); 1849 1850 if (!external_module) 1851 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1852 1853 if (strstarts(mod->name, "drivers/staging")) 1854 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1855 1856 if (strstarts(mod->name, "tools/testing")) 1857 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1858 } 1859 1860 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1861 { 1862 struct symbol *sym; 1863 1864 /* generate struct for exported symbols */ 1865 buf_printf(buf, "\n"); 1866 list_for_each_entry(sym, &mod->exported_symbols, list) { 1867 if (trim_unused_exports && !sym->used) 1868 continue; 1869 1870 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1871 sym->is_func ? "FUNC" : "DATA", sym->name, 1872 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1873 } 1874 1875 if (!modversions) 1876 return; 1877 1878 /* record CRCs for exported symbols */ 1879 buf_printf(buf, "\n"); 1880 list_for_each_entry(sym, &mod->exported_symbols, list) { 1881 if (trim_unused_exports && !sym->used) 1882 continue; 1883 1884 if (!sym->crc_valid) 1885 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1886 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1887 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1888 sym->name); 1889 1890 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1891 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1892 } 1893 } 1894 1895 /** 1896 * Record CRCs for unresolved symbols, supporting long names 1897 */ 1898 static void add_extended_versions(struct buffer *b, struct module *mod) 1899 { 1900 struct symbol *s; 1901 1902 if (!extended_modversions) 1903 return; 1904 1905 buf_printf(b, "\n"); 1906 buf_printf(b, "static const u32 ____version_ext_crcs[]\n"); 1907 buf_printf(b, "__used __section(\"__version_ext_crcs\") = {\n"); 1908 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1909 if (!s->module) 1910 continue; 1911 if (!s->crc_valid) { 1912 warn("\"%s\" [%s.ko] has no CRC!\n", 1913 s->name, mod->name); 1914 continue; 1915 } 1916 buf_printf(b, "\t0x%08x,\n", s->crc); 1917 } 1918 buf_printf(b, "};\n"); 1919 1920 buf_printf(b, "static const char ____version_ext_names[]\n"); 1921 buf_printf(b, "__used __section(\"__version_ext_names\") =\n"); 1922 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1923 if (!s->module) 1924 continue; 1925 if (!s->crc_valid) 1926 /* 1927 * We already warned on this when producing the crc 1928 * table. 1929 * We need to skip its name too, as the indexes in 1930 * both tables need to align. 1931 */ 1932 continue; 1933 buf_printf(b, "\t\"%s\\0\"\n", s->name); 1934 } 1935 buf_printf(b, ";\n"); 1936 } 1937 1938 /** 1939 * Record CRCs for unresolved symbols 1940 **/ 1941 static void add_versions(struct buffer *b, struct module *mod) 1942 { 1943 struct symbol *s; 1944 1945 if (!basic_modversions) 1946 return; 1947 1948 buf_printf(b, "\n"); 1949 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1950 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1951 1952 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1953 if (!s->module) 1954 continue; 1955 if (!s->crc_valid) { 1956 warn("\"%s\" [%s.ko] has no CRC!\n", 1957 s->name, mod->name); 1958 continue; 1959 } 1960 if (strlen(s->name) >= MODULE_NAME_LEN) { 1961 if (extended_modversions) { 1962 /* this symbol will only be in the extended info */ 1963 continue; 1964 } else { 1965 error("too long symbol \"%s\" [%s.ko]\n", 1966 s->name, mod->name); 1967 break; 1968 } 1969 } 1970 buf_printf(b, "\t{ 0x%08x, \"%s\" },\n", 1971 s->crc, s->name); 1972 } 1973 1974 buf_printf(b, "};\n"); 1975 } 1976 1977 static void add_depends(struct buffer *b, struct module *mod) 1978 { 1979 struct symbol *s; 1980 int first = 1; 1981 1982 /* Clear ->seen flag of modules that own symbols needed by this. */ 1983 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1984 if (s->module) 1985 s->module->seen = s->module->is_vmlinux; 1986 } 1987 1988 buf_printf(b, "\n"); 1989 buf_printf(b, "MODULE_INFO(depends, \""); 1990 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1991 const char *p; 1992 if (!s->module) 1993 continue; 1994 1995 if (s->module->seen) 1996 continue; 1997 1998 s->module->seen = true; 1999 p = get_basename(s->module->name); 2000 buf_printf(b, "%s%s", first ? "" : ",", p); 2001 first = 0; 2002 } 2003 buf_printf(b, "\");\n"); 2004 } 2005 2006 static void add_srcversion(struct buffer *b, struct module *mod) 2007 { 2008 if (mod->srcversion[0]) { 2009 buf_printf(b, "\n"); 2010 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 2011 mod->srcversion); 2012 } 2013 } 2014 2015 static void write_buf(struct buffer *b, const char *fname) 2016 { 2017 FILE *file; 2018 2019 if (error_occurred) 2020 return; 2021 2022 file = fopen(fname, "w"); 2023 if (!file) { 2024 perror(fname); 2025 exit(1); 2026 } 2027 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2028 perror(fname); 2029 exit(1); 2030 } 2031 if (fclose(file) != 0) { 2032 perror(fname); 2033 exit(1); 2034 } 2035 } 2036 2037 static void write_if_changed(struct buffer *b, const char *fname) 2038 { 2039 char *tmp; 2040 FILE *file; 2041 struct stat st; 2042 2043 file = fopen(fname, "r"); 2044 if (!file) 2045 goto write; 2046 2047 if (fstat(fileno(file), &st) < 0) 2048 goto close_write; 2049 2050 if (st.st_size != b->pos) 2051 goto close_write; 2052 2053 tmp = xmalloc(b->pos); 2054 if (fread(tmp, 1, b->pos, file) != b->pos) 2055 goto free_write; 2056 2057 if (memcmp(tmp, b->p, b->pos) != 0) 2058 goto free_write; 2059 2060 free(tmp); 2061 fclose(file); 2062 return; 2063 2064 free_write: 2065 free(tmp); 2066 close_write: 2067 fclose(file); 2068 write: 2069 write_buf(b, fname); 2070 } 2071 2072 static void write_vmlinux_export_c_file(struct module *mod) 2073 { 2074 struct buffer buf = { }; 2075 struct module_alias *alias, *next; 2076 2077 buf_printf(&buf, 2078 "#include <linux/export-internal.h>\n"); 2079 2080 add_exported_symbols(&buf, mod); 2081 2082 buf_printf(&buf, 2083 "#include <linux/module.h>\n" 2084 "#undef __MODULE_INFO_PREFIX\n" 2085 "#define __MODULE_INFO_PREFIX\n"); 2086 2087 list_for_each_entry_safe(alias, next, &mod->aliases, node) { 2088 buf_printf(&buf, "MODULE_INFO(%s.alias, \"%s\");\n", 2089 alias->builtin_modname, alias->str); 2090 list_del(&alias->node); 2091 free(alias->builtin_modname); 2092 free(alias); 2093 } 2094 2095 write_if_changed(&buf, ".vmlinux.export.c"); 2096 free(buf.p); 2097 } 2098 2099 /* do sanity checks, and generate *.mod.c file */ 2100 static void write_mod_c_file(struct module *mod) 2101 { 2102 struct buffer buf = { }; 2103 struct module_alias *alias, *next; 2104 char fname[PATH_MAX]; 2105 int ret; 2106 2107 add_header(&buf, mod); 2108 add_exported_symbols(&buf, mod); 2109 add_versions(&buf, mod); 2110 add_extended_versions(&buf, mod); 2111 add_depends(&buf, mod); 2112 2113 buf_printf(&buf, "\n"); 2114 list_for_each_entry_safe(alias, next, &mod->aliases, node) { 2115 buf_printf(&buf, "MODULE_ALIAS(\"%s\");\n", alias->str); 2116 list_del(&alias->node); 2117 free(alias); 2118 } 2119 2120 add_srcversion(&buf, mod); 2121 2122 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2123 if (ret >= sizeof(fname)) { 2124 error("%s: too long path was truncated\n", fname); 2125 goto free; 2126 } 2127 2128 write_if_changed(&buf, fname); 2129 2130 free: 2131 free(buf.p); 2132 } 2133 2134 /* parse Module.symvers file. line format: 2135 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2136 **/ 2137 static void read_dump(const char *fname) 2138 { 2139 char *buf, *pos, *line; 2140 2141 buf = read_text_file(fname); 2142 if (!buf) 2143 /* No symbol versions, silently ignore */ 2144 return; 2145 2146 pos = buf; 2147 2148 while ((line = get_line(&pos))) { 2149 char *symname, *namespace, *modname, *d, *export; 2150 unsigned int crc; 2151 struct module *mod; 2152 struct symbol *s; 2153 bool gpl_only; 2154 2155 if (!(symname = strchr(line, '\t'))) 2156 goto fail; 2157 *symname++ = '\0'; 2158 if (!(modname = strchr(symname, '\t'))) 2159 goto fail; 2160 *modname++ = '\0'; 2161 if (!(export = strchr(modname, '\t'))) 2162 goto fail; 2163 *export++ = '\0'; 2164 if (!(namespace = strchr(export, '\t'))) 2165 goto fail; 2166 *namespace++ = '\0'; 2167 2168 crc = strtoul(line, &d, 16); 2169 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2170 goto fail; 2171 2172 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2173 gpl_only = true; 2174 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2175 gpl_only = false; 2176 } else { 2177 error("%s: unknown license %s. skip", symname, export); 2178 continue; 2179 } 2180 2181 mod = find_module(fname, modname); 2182 if (!mod) { 2183 mod = new_module(modname, strlen(modname)); 2184 mod->dump_file = fname; 2185 } 2186 s = sym_add_exported(symname, mod, gpl_only, namespace); 2187 sym_set_crc(s, crc); 2188 } 2189 free(buf); 2190 return; 2191 fail: 2192 free(buf); 2193 fatal("parse error in symbol dump file\n"); 2194 } 2195 2196 static void write_dump(const char *fname) 2197 { 2198 struct buffer buf = { }; 2199 struct module *mod; 2200 struct symbol *sym; 2201 2202 list_for_each_entry(mod, &modules, list) { 2203 if (mod->dump_file) 2204 continue; 2205 list_for_each_entry(sym, &mod->exported_symbols, list) { 2206 if (trim_unused_exports && !sym->used) 2207 continue; 2208 2209 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2210 sym->crc, sym->name, mod->name, 2211 sym->is_gpl_only ? "_GPL" : "", 2212 sym->namespace); 2213 } 2214 } 2215 write_buf(&buf, fname); 2216 free(buf.p); 2217 } 2218 2219 static void write_namespace_deps_files(const char *fname) 2220 { 2221 struct module *mod; 2222 struct namespace_list *ns; 2223 struct buffer ns_deps_buf = {}; 2224 2225 list_for_each_entry(mod, &modules, list) { 2226 2227 if (mod->dump_file || list_empty(&mod->missing_namespaces)) 2228 continue; 2229 2230 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2231 2232 list_for_each_entry(ns, &mod->missing_namespaces, list) 2233 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2234 2235 buf_printf(&ns_deps_buf, "\n"); 2236 } 2237 2238 write_if_changed(&ns_deps_buf, fname); 2239 free(ns_deps_buf.p); 2240 } 2241 2242 struct dump_list { 2243 struct list_head list; 2244 const char *file; 2245 }; 2246 2247 static void check_host_endian(void) 2248 { 2249 static const union { 2250 short s; 2251 char c[2]; 2252 } endian_test = { .c = {0x01, 0x02} }; 2253 2254 switch (endian_test.s) { 2255 case 0x0102: 2256 host_is_big_endian = true; 2257 break; 2258 case 0x0201: 2259 host_is_big_endian = false; 2260 break; 2261 default: 2262 fatal("Unknown host endian\n"); 2263 } 2264 } 2265 2266 int main(int argc, char **argv) 2267 { 2268 struct module *mod; 2269 char *missing_namespace_deps = NULL; 2270 char *unused_exports_white_list = NULL; 2271 char *dump_write = NULL, *files_source = NULL; 2272 int opt; 2273 LIST_HEAD(dump_lists); 2274 struct dump_list *dl, *dl2; 2275 2276 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:xb")) != -1) { 2277 switch (opt) { 2278 case 'e': 2279 external_module = true; 2280 break; 2281 case 'i': 2282 dl = xmalloc(sizeof(*dl)); 2283 dl->file = optarg; 2284 list_add_tail(&dl->list, &dump_lists); 2285 break; 2286 case 'M': 2287 module_enabled = true; 2288 break; 2289 case 'm': 2290 modversions = true; 2291 break; 2292 case 'n': 2293 ignore_missing_files = true; 2294 break; 2295 case 'o': 2296 dump_write = optarg; 2297 break; 2298 case 'a': 2299 all_versions = true; 2300 break; 2301 case 'T': 2302 files_source = optarg; 2303 break; 2304 case 't': 2305 trim_unused_exports = true; 2306 break; 2307 case 'u': 2308 unused_exports_white_list = optarg; 2309 break; 2310 case 'W': 2311 extra_warn = true; 2312 break; 2313 case 'w': 2314 warn_unresolved = true; 2315 break; 2316 case 'E': 2317 sec_mismatch_warn_only = false; 2318 break; 2319 case 'N': 2320 allow_missing_ns_imports = true; 2321 break; 2322 case 'd': 2323 missing_namespace_deps = optarg; 2324 break; 2325 case 'b': 2326 basic_modversions = true; 2327 break; 2328 case 'x': 2329 extended_modversions = true; 2330 break; 2331 default: 2332 exit(1); 2333 } 2334 } 2335 2336 check_host_endian(); 2337 2338 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2339 read_dump(dl->file); 2340 list_del(&dl->list); 2341 free(dl); 2342 } 2343 2344 while (optind < argc) 2345 read_symbols(argv[optind++]); 2346 2347 if (files_source) 2348 read_symbols_from_files(files_source); 2349 2350 list_for_each_entry(mod, &modules, list) { 2351 keep_no_trim_symbols(mod); 2352 2353 if (mod->dump_file || mod->is_vmlinux) 2354 continue; 2355 2356 check_modname_len(mod); 2357 check_exports(mod); 2358 } 2359 2360 if (unused_exports_white_list) 2361 handle_white_list_exports(unused_exports_white_list); 2362 2363 list_for_each_entry(mod, &modules, list) { 2364 if (mod->dump_file) 2365 continue; 2366 2367 if (mod->is_vmlinux) 2368 write_vmlinux_export_c_file(mod); 2369 else 2370 write_mod_c_file(mod); 2371 } 2372 2373 if (missing_namespace_deps) 2374 write_namespace_deps_files(missing_namespace_deps); 2375 2376 if (dump_write) 2377 write_dump(dump_write); 2378 if (sec_mismatch_count && !sec_mismatch_warn_only) 2379 error("Section mismatches detected.\n" 2380 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2381 2382 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2383 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2384 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2385 2386 return error_occurred ? 1 : 0; 2387 } 2388