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