1 /* Postprocess module symbol versions 2 * 3 * Copyright 2003 Kai Germaschewski 4 * Copyright 2002-2004 Rusty Russell, IBM Corporation 5 * Copyright 2006-2008 Sam Ravnborg 6 * Based in part on module-init-tools/depmod.c,file2alias 7 * 8 * This software may be used and distributed according to the terms 9 * of the GNU General Public License, incorporated herein by reference. 10 * 11 * Usage: modpost vmlinux module1.o module2.o ... 12 */ 13 14 #define _GNU_SOURCE 15 #include <elf.h> 16 #include <fnmatch.h> 17 #include <stdio.h> 18 #include <ctype.h> 19 #include <string.h> 20 #include <limits.h> 21 #include <stdbool.h> 22 #include <errno.h> 23 24 #include <hash.h> 25 #include <hashtable.h> 26 #include <list.h> 27 #include <xalloc.h> 28 #include "modpost.h" 29 #include "../../include/linux/license.h" 30 31 #define MODULE_NS_PREFIX "module:" 32 33 static bool module_enabled; 34 /* Are we using CONFIG_MODVERSIONS? */ 35 static bool modversions; 36 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 37 static bool all_versions; 38 /* Is CONFIG_BASIC_MODVERSIONS set? */ 39 static bool basic_modversions; 40 /* Is CONFIG_EXTENDED_MODVERSIONS set? */ 41 static bool extended_modversions; 42 /* If we are modposting external module set to 1 */ 43 static bool external_module; 44 /* Only warn about unresolved symbols */ 45 static bool warn_unresolved; 46 47 static int sec_mismatch_count; 48 static bool sec_mismatch_warn_only = true; 49 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */ 50 static bool trim_unused_exports; 51 52 /* ignore missing files */ 53 static bool ignore_missing_files; 54 /* If set to 1, only warn (instead of error) about missing ns imports */ 55 static bool allow_missing_ns_imports; 56 57 static bool error_occurred; 58 59 static bool extra_warn __attribute__((unused)); 60 61 bool target_is_big_endian; 62 bool host_is_big_endian; 63 64 /* 65 * Cut off the warnings when there are too many. This typically occurs when 66 * vmlinux is missing. ('make modules' without building vmlinux.) 67 */ 68 #define MAX_UNRESOLVED_REPORTS 10 69 static unsigned int nr_unresolved; 70 71 /* In kernel, this size is defined in linux/module.h; 72 * here we use Elf_Addr instead of long for covering cross-compile 73 */ 74 75 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) 76 77 void modpost_log(bool is_error, struct module *mod, 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 if (mod) 91 fprintf(stderr, "%s%s: ", mod->name, mod->is_vmlinux ? "" : ".ko"); 92 93 va_start(arglist, fmt); 94 vfprintf(stderr, fmt, arglist); 95 va_end(arglist); 96 } 97 98 #define mod_warn(mod, fmt, args...) modpost_log(false, mod, fmt, ##args) 99 #define mod_error(mod, fmt, args...) modpost_log(true, mod, fmt, ##args) 100 101 static inline bool strends(const char *str, const char *postfix) 102 { 103 if (strlen(str) < strlen(postfix)) 104 return false; 105 106 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; 107 } 108 109 /** 110 * get_basename - return the last part of a pathname. 111 * 112 * @path: path to extract the filename from. 113 */ 114 const char *get_basename(const char *path) 115 { 116 const char *tail = strrchr(path, '/'); 117 118 return tail ? tail + 1 : path; 119 } 120 121 char *read_text_file(const char *filename) 122 { 123 struct stat st; 124 size_t nbytes; 125 int fd; 126 char *buf; 127 128 fd = open(filename, O_RDONLY); 129 if (fd < 0) { 130 perror(filename); 131 exit(1); 132 } 133 134 if (fstat(fd, &st) < 0) { 135 perror(filename); 136 exit(1); 137 } 138 139 buf = xmalloc(st.st_size + 1); 140 141 nbytes = st.st_size; 142 143 while (nbytes) { 144 ssize_t bytes_read; 145 146 bytes_read = read(fd, buf, nbytes); 147 if (bytes_read < 0) { 148 perror(filename); 149 exit(1); 150 } 151 152 nbytes -= bytes_read; 153 } 154 buf[st.st_size] = '\0'; 155 156 close(fd); 157 158 return buf; 159 } 160 161 char *get_line(char **stringp) 162 { 163 char *orig = *stringp, *next; 164 165 /* do not return the unwanted extra line at EOF */ 166 if (!orig || *orig == '\0') 167 return NULL; 168 169 /* don't use strsep here, it is not available everywhere */ 170 next = strchr(orig, '\n'); 171 if (next) 172 *next++ = '\0'; 173 174 *stringp = next; 175 176 return orig; 177 } 178 179 /* A list of all modules we processed */ 180 LIST_HEAD(modules); 181 182 static struct module *find_module(const char *filename, const char *modname) 183 { 184 struct module *mod; 185 186 list_for_each_entry(mod, &modules, list) { 187 if (!strcmp(mod->dump_file, filename) && 188 !strcmp(mod->name, modname)) 189 return mod; 190 } 191 return NULL; 192 } 193 194 static struct module *new_module(const char *name, size_t namelen) 195 { 196 struct module *mod; 197 198 mod = xmalloc(sizeof(*mod) + namelen + 1); 199 memset(mod, 0, sizeof(*mod)); 200 201 INIT_LIST_HEAD(&mod->exported_symbols); 202 INIT_LIST_HEAD(&mod->unresolved_symbols); 203 INIT_LIST_HEAD(&mod->missing_namespaces); 204 INIT_LIST_HEAD(&mod->imported_namespaces); 205 INIT_LIST_HEAD(&mod->aliases); 206 207 memcpy(mod->name, name, namelen); 208 mod->name[namelen] = '\0'; 209 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0); 210 211 /* 212 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE() 213 * is missing, do not check the use for EXPORT_SYMBOL_GPL() because 214 * modpost will exit with an error anyway. 215 */ 216 mod->is_gpl_compatible = true; 217 218 list_add_tail(&mod->list, &modules); 219 220 return mod; 221 } 222 223 struct symbol { 224 struct hlist_node hnode;/* link to hash table */ 225 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */ 226 struct module *module; 227 char *namespace; 228 unsigned int crc; 229 bool crc_valid; 230 bool weak; 231 bool is_func; 232 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ 233 bool used; /* there exists a user of this symbol */ 234 char name[]; 235 }; 236 237 static HASHTABLE_DEFINE(symbol_hashtable, 1U << 10); 238 239 /** 240 * Allocate a new symbols for use in the hash of exported symbols or 241 * the list of unresolved symbols per module 242 **/ 243 static struct symbol *alloc_symbol(const char *name) 244 { 245 struct symbol *s = xmalloc(sizeof(*s) + strlen(name) + 1); 246 247 memset(s, 0, sizeof(*s)); 248 strcpy(s->name, name); 249 250 return s; 251 } 252 253 static uint8_t get_symbol_flags(const struct symbol *sym) 254 { 255 return sym->is_gpl_only ? KSYM_FLAG_GPL_ONLY : 0; 256 } 257 258 /* For the hash of exported symbols */ 259 static void hash_add_symbol(struct symbol *sym) 260 { 261 hash_add(symbol_hashtable, &sym->hnode, hash_str(sym->name)); 262 } 263 264 static void sym_add_unresolved(const char *name, struct module *mod, bool weak) 265 { 266 struct symbol *sym; 267 268 sym = alloc_symbol(name); 269 sym->weak = weak; 270 271 list_add_tail(&sym->list, &mod->unresolved_symbols); 272 } 273 274 static struct symbol *sym_find_with_module(const char *name, struct module *mod) 275 { 276 struct symbol *s; 277 278 /* For our purposes, .foo matches foo. PPC64 needs this. */ 279 if (name[0] == '.') 280 name++; 281 282 hash_for_each_possible(symbol_hashtable, s, hnode, hash_str(name)) { 283 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) 284 return s; 285 } 286 return NULL; 287 } 288 289 static struct symbol *find_symbol(const char *name) 290 { 291 return sym_find_with_module(name, NULL); 292 } 293 294 struct namespace_list { 295 struct list_head list; 296 char namespace[]; 297 }; 298 299 static bool contains_namespace(struct list_head *head, const char *namespace) 300 { 301 struct namespace_list *list; 302 303 /* 304 * The default namespace is null string "", which is always implicitly 305 * contained. 306 */ 307 if (!namespace[0]) 308 return true; 309 310 list_for_each_entry(list, head, list) { 311 if (!strcmp(list->namespace, namespace)) 312 return true; 313 } 314 315 return false; 316 } 317 318 static void add_namespace(struct list_head *head, const char *namespace) 319 { 320 struct namespace_list *ns_entry; 321 322 if (!contains_namespace(head, namespace)) { 323 ns_entry = xmalloc(sizeof(*ns_entry) + strlen(namespace) + 1); 324 strcpy(ns_entry->namespace, namespace); 325 list_add_tail(&ns_entry->list, head); 326 } 327 } 328 329 static void *sym_get_data_by_offset(const struct elf_info *info, 330 unsigned int secindex, unsigned long offset) 331 { 332 Elf_Shdr *sechdr = &info->sechdrs[secindex]; 333 334 return (void *)info->hdr + sechdr->sh_offset + offset; 335 } 336 337 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) 338 { 339 return sym_get_data_by_offset(info, get_secindex(info, sym), 340 sym->st_value); 341 } 342 343 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) 344 { 345 return sym_get_data_by_offset(info, info->secindex_strings, 346 sechdr->sh_name); 347 } 348 349 static const char *sec_name(const struct elf_info *info, unsigned int secindex) 350 { 351 /* 352 * If sym->st_shndx is a special section index, there is no 353 * corresponding section header. 354 * Return "" if the index is out of range of info->sechdrs[] array. 355 */ 356 if (secindex >= info->num_sections) 357 return ""; 358 359 return sech_name(info, &info->sechdrs[secindex]); 360 } 361 362 static struct symbol *sym_add_exported(const char *name, struct module *mod, 363 bool gpl_only, const char *namespace) 364 { 365 struct symbol *s = find_symbol(name); 366 367 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { 368 mod_error(mod, "symbol '%s' exported twice. Previous export was in %s%s\n", 369 name, s->module->name, s->module->is_vmlinux ? "" : ".ko"); 370 } 371 372 s = alloc_symbol(name); 373 s->module = mod; 374 s->is_gpl_only = gpl_only; 375 s->namespace = xstrdup(namespace); 376 list_add_tail(&s->list, &mod->exported_symbols); 377 hash_add_symbol(s); 378 379 return s; 380 } 381 382 static void sym_set_crc(struct symbol *sym, unsigned int crc) 383 { 384 sym->crc = crc; 385 sym->crc_valid = true; 386 } 387 388 static void *grab_file(const char *filename, size_t *size) 389 { 390 struct stat st; 391 void *map = MAP_FAILED; 392 int fd; 393 394 fd = open(filename, O_RDONLY); 395 if (fd < 0) 396 return NULL; 397 if (fstat(fd, &st)) 398 goto failed; 399 400 *size = st.st_size; 401 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 402 403 failed: 404 close(fd); 405 if (map == MAP_FAILED) 406 return NULL; 407 return map; 408 } 409 410 static void release_file(void *file, size_t size) 411 { 412 munmap(file, size); 413 } 414 415 static int parse_elf(struct elf_info *info, const char *filename) 416 { 417 unsigned int i; 418 Elf_Ehdr *hdr; 419 Elf_Shdr *sechdrs; 420 Elf_Sym *sym; 421 const char *secstrings; 422 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 423 424 hdr = grab_file(filename, &info->size); 425 if (!hdr) { 426 if (ignore_missing_files) { 427 fprintf(stderr, "%s: %s (ignored)\n", filename, 428 strerror(errno)); 429 return 0; 430 } 431 perror(filename); 432 exit(1); 433 } 434 info->hdr = hdr; 435 if (info->size < sizeof(*hdr)) { 436 /* file too small, assume this is an empty .o file */ 437 return 0; 438 } 439 /* Is this a valid ELF file? */ 440 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 441 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 442 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 443 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 444 /* Not an ELF file - silently ignore it */ 445 return 0; 446 } 447 448 switch (hdr->e_ident[EI_DATA]) { 449 case ELFDATA2LSB: 450 target_is_big_endian = false; 451 break; 452 case ELFDATA2MSB: 453 target_is_big_endian = true; 454 break; 455 default: 456 fatal("target endian is unknown\n"); 457 } 458 459 /* Fix endianness in ELF header */ 460 hdr->e_type = TO_NATIVE(hdr->e_type); 461 hdr->e_machine = TO_NATIVE(hdr->e_machine); 462 hdr->e_version = TO_NATIVE(hdr->e_version); 463 hdr->e_entry = TO_NATIVE(hdr->e_entry); 464 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 465 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 466 hdr->e_flags = TO_NATIVE(hdr->e_flags); 467 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 468 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 469 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 470 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 471 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 472 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 473 sechdrs = (void *)hdr + hdr->e_shoff; 474 info->sechdrs = sechdrs; 475 476 /* modpost only works for relocatable objects */ 477 if (hdr->e_type != ET_REL) 478 fatal("%s: not relocatable object.", filename); 479 480 /* Check if file offset is correct */ 481 if (hdr->e_shoff > info->size) 482 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", 483 (unsigned long)hdr->e_shoff, filename, info->size); 484 485 if (hdr->e_shnum == SHN_UNDEF) { 486 /* 487 * There are more than 64k sections, 488 * read count from .sh_size. 489 */ 490 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 491 } 492 else { 493 info->num_sections = hdr->e_shnum; 494 } 495 if (hdr->e_shstrndx == SHN_XINDEX) { 496 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 497 } 498 else { 499 info->secindex_strings = hdr->e_shstrndx; 500 } 501 502 /* Fix endianness in section headers */ 503 for (i = 0; i < info->num_sections; i++) { 504 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 505 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 506 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 507 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 508 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 509 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 510 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 511 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 512 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 513 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 514 } 515 /* Find symbol table. */ 516 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 517 for (i = 1; i < info->num_sections; i++) { 518 const char *secname; 519 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 520 521 if (!nobits && sechdrs[i].sh_offset > info->size) 522 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n", 523 filename, (unsigned long)sechdrs[i].sh_offset, 524 sizeof(*hdr)); 525 526 secname = secstrings + sechdrs[i].sh_name; 527 if (strcmp(secname, ".modinfo") == 0) { 528 if (nobits) 529 fatal("%s has NOBITS .modinfo\n", filename); 530 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 531 info->modinfo_len = sechdrs[i].sh_size; 532 } else if (!strcmp(secname, ".export_symbol")) { 533 info->export_symbol_secndx = i; 534 } else if (!strcmp(secname, ".no_trim_symbol")) { 535 info->no_trim_symbol = (void *)hdr + sechdrs[i].sh_offset; 536 info->no_trim_symbol_len = sechdrs[i].sh_size; 537 } 538 539 if (sechdrs[i].sh_type == SHT_SYMTAB) { 540 unsigned int sh_link_idx; 541 symtab_idx = i; 542 info->symtab_start = (void *)hdr + 543 sechdrs[i].sh_offset; 544 info->symtab_stop = (void *)hdr + 545 sechdrs[i].sh_offset + sechdrs[i].sh_size; 546 sh_link_idx = sechdrs[i].sh_link; 547 info->strtab = (void *)hdr + 548 sechdrs[sh_link_idx].sh_offset; 549 } 550 551 /* 32bit section no. table? ("more than 64k sections") */ 552 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 553 symtab_shndx_idx = i; 554 info->symtab_shndx_start = (void *)hdr + 555 sechdrs[i].sh_offset; 556 info->symtab_shndx_stop = (void *)hdr + 557 sechdrs[i].sh_offset + sechdrs[i].sh_size; 558 } 559 } 560 if (!info->symtab_start) 561 fatal("%s has no symtab?\n", filename); 562 563 /* Fix endianness in symbols */ 564 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 565 sym->st_shndx = TO_NATIVE(sym->st_shndx); 566 sym->st_name = TO_NATIVE(sym->st_name); 567 sym->st_value = TO_NATIVE(sym->st_value); 568 sym->st_size = TO_NATIVE(sym->st_size); 569 } 570 571 if (symtab_shndx_idx != ~0U) { 572 Elf32_Word *p; 573 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 574 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 575 filename, sechdrs[symtab_shndx_idx].sh_link, 576 symtab_idx); 577 /* Fix endianness */ 578 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 579 p++) 580 *p = TO_NATIVE(*p); 581 } 582 583 symsearch_init(info); 584 585 return 1; 586 } 587 588 static void parse_elf_finish(struct elf_info *info) 589 { 590 symsearch_finish(info); 591 release_file(info->hdr, info->size); 592 } 593 594 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 595 { 596 /* ignore __this_module, it will be resolved shortly */ 597 if (strcmp(symname, "__this_module") == 0) 598 return 1; 599 /* ignore global offset table */ 600 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 601 return 1; 602 if (info->hdr->e_machine == EM_PPC) 603 /* Special register function linked on all modules during final link of .ko */ 604 if (strstarts(symname, "_restgpr_") || 605 strstarts(symname, "_savegpr_") || 606 strstarts(symname, "_rest32gpr_") || 607 strstarts(symname, "_save32gpr_") || 608 strstarts(symname, "_restvr_") || 609 strstarts(symname, "_savevr_")) 610 return 1; 611 if (info->hdr->e_machine == EM_PPC64) 612 /* Special register function linked on all modules during final link of .ko */ 613 if (strstarts(symname, "_restgpr0_") || 614 strstarts(symname, "_savegpr0_") || 615 strstarts(symname, "_restgpr1_") || 616 strstarts(symname, "_savegpr1_") || 617 strstarts(symname, "_restfpr_") || 618 strstarts(symname, "_savefpr_") || 619 strstarts(symname, "_restvr_") || 620 strstarts(symname, "_savevr_") || 621 strcmp(symname, ".TOC.") == 0) 622 return 1; 623 624 /* ignore linker-created section bounds variables */ 625 if (strstarts(symname, "__start_") || strstarts(symname, "__stop_")) 626 return 1; 627 628 /* Do not ignore this symbol */ 629 return 0; 630 } 631 632 static void handle_symbol(struct module *mod, struct elf_info *info, 633 const Elf_Sym *sym, const char *symname) 634 { 635 switch (sym->st_shndx) { 636 case SHN_COMMON: 637 if (strstarts(symname, "__gnu_lto_")) { 638 /* Should warn here, but modpost runs before the linker */ 639 } else 640 mod_warn(mod, "'%s' is COMMON symbol\n", symname); 641 break; 642 case SHN_UNDEF: 643 /* undefined symbol */ 644 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 645 ELF_ST_BIND(sym->st_info) != STB_WEAK) 646 break; 647 if (ignore_undef_symbol(info, symname)) 648 break; 649 if (info->hdr->e_machine == EM_SPARC || 650 info->hdr->e_machine == EM_SPARCV9) { 651 /* Ignore register directives. */ 652 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 653 break; 654 if (symname[0] == '.') { 655 char *munged = xstrdup(symname); 656 munged[0] = '_'; 657 munged[1] = toupper(munged[1]); 658 symname = munged; 659 } 660 } 661 662 sym_add_unresolved(symname, mod, 663 ELF_ST_BIND(sym->st_info) == STB_WEAK); 664 break; 665 default: 666 if (strcmp(symname, "init_module") == 0) 667 mod->has_init = true; 668 if (strcmp(symname, "cleanup_module") == 0) 669 mod->has_cleanup = true; 670 break; 671 } 672 } 673 674 /** 675 * Parse tag=value strings from .modinfo section 676 **/ 677 static char *next_string(char *string, unsigned long *secsize) 678 { 679 /* Skip non-zero chars */ 680 while (string[0]) { 681 string++; 682 if ((*secsize)-- <= 1) 683 return NULL; 684 } 685 686 /* Skip any zero padding. */ 687 while (!string[0]) { 688 string++; 689 if ((*secsize)-- <= 1) 690 return NULL; 691 } 692 return string; 693 } 694 695 static char *get_next_modinfo(struct elf_info *info, const char *tag, 696 char *prev) 697 { 698 char *p; 699 unsigned int taglen = strlen(tag); 700 char *modinfo = info->modinfo; 701 unsigned long size = info->modinfo_len; 702 703 if (prev) { 704 size -= prev - modinfo; 705 modinfo = next_string(prev, &size); 706 } 707 708 for (p = modinfo; p; p = next_string(p, &size)) { 709 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 710 return p + taglen + 1; 711 } 712 return NULL; 713 } 714 715 static char *get_modinfo(struct elf_info *info, const char *tag) 716 717 { 718 return get_next_modinfo(info, tag, NULL); 719 } 720 721 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 722 { 723 return sym ? elf->strtab + sym->st_name : ""; 724 } 725 726 /* 727 * Check whether the 'string' argument matches one of the 'patterns', 728 * an array of shell wildcard patterns (glob). 729 * 730 * Return true is there is a match. 731 */ 732 static bool match(const char *string, const char *const patterns[]) 733 { 734 const char *pattern; 735 736 while ((pattern = *patterns++)) { 737 if (!fnmatch(pattern, string, 0)) 738 return true; 739 } 740 741 return false; 742 } 743 744 /* useful to pass patterns to match() directly */ 745 #define PATTERNS(...) \ 746 ({ \ 747 static const char *const patterns[] = {__VA_ARGS__, NULL}; \ 748 patterns; \ 749 }) 750 751 /* sections that we do not want to do full section mismatch check on */ 752 static const char *const section_white_list[] = 753 { 754 ".comment*", 755 ".debug*", 756 ".zdebug*", /* Compressed debug sections. */ 757 ".GCC.command.line", /* record-gcc-switches */ 758 ".mdebug*", /* alpha, score, mips etc. */ 759 ".pdr", /* alpha, score, mips etc. */ 760 ".stab*", 761 ".note*", 762 ".got*", 763 ".toc*", 764 ".xt.prop", /* xtensa */ 765 ".xt.lit", /* xtensa */ 766 ".arcextmap*", /* arc */ 767 ".gnu.linkonce.arcext*", /* arc : modules */ 768 ".cmem*", /* EZchip */ 769 ".fmt_slot*", /* EZchip */ 770 ".gnu.lto*", 771 ".discard.*", 772 ".llvm.call-graph-profile", /* call graph */ 773 "__llvm_covfun", 774 "__llvm_covmap", 775 ".klp.symid", /* objtool --klp-symids */ 776 NULL 777 }; 778 779 /* 780 * This is used to find sections missing the SHF_ALLOC flag. 781 * The cause of this is often a section specified in assembler 782 * without "ax" / "aw". 783 */ 784 static void check_section(struct module *mod, struct elf_info *elf, 785 Elf_Shdr *sechdr) 786 { 787 const char *sec = sech_name(elf, sechdr); 788 789 if (sechdr->sh_type == SHT_PROGBITS && 790 !(sechdr->sh_flags & SHF_ALLOC) && 791 !match(sec, section_white_list)) { 792 mod_warn(mod, "unexpected non-allocatable section '%s'.\n" 793 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 794 "Note that for example <linux/init.h> contains\n" 795 "section definitions for use in .S files.\n\n", 796 sec); 797 } 798 } 799 800 801 802 #define ALL_INIT_DATA_SECTIONS \ 803 ".init.setup", ".init.rodata", ".init.data" 804 805 #define ALL_PCI_INIT_SECTIONS \ 806 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 807 ".pci_fixup_enable", ".pci_fixup_resume", \ 808 ".pci_fixup_resume_early", ".pci_fixup_suspend" 809 810 #define ALL_INIT_SECTIONS ".init.*" 811 #define ALL_EXIT_SECTIONS ".exit.*" 812 813 #define DATA_SECTIONS ".data", ".data.rel" 814 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ 815 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \ 816 ".ltext", ".ltext.*" 817 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ 818 ".fixup", ".entry.text", ".exception.text", \ 819 ".coldtext", ".softirqentry.text", ".irqentry.text" 820 821 #define ALL_TEXT_SECTIONS ".init.text", ".exit.text", \ 822 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 823 824 enum mismatch { 825 TEXTDATA_TO_ANY_INIT_EXIT, 826 XXXINIT_TO_SOME_INIT, 827 ANY_INIT_TO_ANY_EXIT, 828 ANY_EXIT_TO_ANY_INIT, 829 EXTABLE_TO_NON_TEXT, 830 }; 831 832 /** 833 * Describe how to match sections on different criteria: 834 * 835 * @fromsec: Array of sections to be matched. 836 * 837 * @bad_tosec: Relocations applied to a section in @fromsec to a section in 838 * this array is forbidden (black-list). Can be empty. 839 * 840 * @good_tosec: Relocations applied to a section in @fromsec must be 841 * targeting sections in this array (white-list). Can be empty. 842 * 843 * @mismatch: Type of mismatch. 844 */ 845 struct sectioncheck { 846 const char *fromsec[20]; 847 const char *bad_tosec[20]; 848 const char *good_tosec[20]; 849 enum mismatch mismatch; 850 }; 851 852 static const struct sectioncheck sectioncheck[] = { 853 /* Do not reference init/exit code/data from 854 * normal code and data 855 */ 856 { 857 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 858 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }, 859 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT, 860 }, 861 /* Do not use exit code/data from init code */ 862 { 863 .fromsec = { ALL_INIT_SECTIONS, NULL }, 864 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 865 .mismatch = ANY_INIT_TO_ANY_EXIT, 866 }, 867 /* Do not use init code/data from exit code */ 868 { 869 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 870 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 871 .mismatch = ANY_EXIT_TO_ANY_INIT, 872 }, 873 { 874 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 875 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 876 .mismatch = ANY_INIT_TO_ANY_EXIT, 877 }, 878 { 879 .fromsec = { "__ex_table", NULL }, 880 /* If you're adding any new black-listed sections in here, consider 881 * adding a special 'printer' for them in scripts/check_extable. 882 */ 883 .bad_tosec = { ".altinstr_replacement", NULL }, 884 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 885 .mismatch = EXTABLE_TO_NON_TEXT, 886 } 887 }; 888 889 static const struct sectioncheck *section_mismatch( 890 const char *fromsec, const char *tosec) 891 { 892 int i; 893 894 /* 895 * The target section could be the SHT_NUL section when we're 896 * handling relocations to un-resolved symbols, trying to match it 897 * doesn't make much sense and causes build failures on parisc 898 * architectures. 899 */ 900 if (*tosec == '\0') 901 return NULL; 902 903 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 904 const struct sectioncheck *check = §ioncheck[i]; 905 906 if (match(fromsec, check->fromsec)) { 907 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 908 return check; 909 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 910 return check; 911 } 912 } 913 return NULL; 914 } 915 916 /** 917 * Whitelist to allow certain references to pass with no warning. 918 * 919 * Pattern 1: 920 * If a module parameter is declared __initdata and permissions=0 921 * then this is legal despite the warning generated. 922 * We cannot see value of permissions here, so just ignore 923 * this pattern. 924 * The pattern is identified by: 925 * tosec = .init.data 926 * fromsec = .data* 927 * atsym =__param* 928 * 929 * Pattern 1a: 930 * module_param_call() ops can refer to __init set function if permissions=0 931 * The pattern is identified by: 932 * tosec = .init.text 933 * fromsec = .data* 934 * atsym = __param_ops_* 935 * 936 * Pattern 3: 937 * Whitelist all references from .head.text to any init section 938 * 939 * Pattern 4: 940 * Some symbols belong to init section but still it is ok to reference 941 * these from non-init sections as these symbols don't have any memory 942 * allocated for them and symbol address and value are same. So even 943 * if init section is freed, its ok to reference those symbols. 944 * For ex. symbols marking the init section boundaries. 945 * This pattern is identified by 946 * refsymname = __init_begin, _sinittext, _einittext 947 * 948 * Pattern 5: 949 * GCC may optimize static inlines when fed constant arg(s) resulting 950 * in functions like cpumask_empty() -- generating an associated symbol 951 * cpumask_empty.constprop.3 that appears in the audit. If the const that 952 * is passed in comes from __init, like say nmi_ipi_mask, we get a 953 * meaningless section warning. May need to add isra symbols too... 954 * This pattern is identified by 955 * tosec = init section 956 * fromsec = text section 957 * refsymname = *.constprop.* 958 * 959 **/ 960 static int secref_whitelist(const char *fromsec, const char *fromsym, 961 const char *tosec, const char *tosym) 962 { 963 /* Check for pattern 1 */ 964 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 965 match(fromsec, PATTERNS(DATA_SECTIONS)) && 966 strstarts(fromsym, "__param")) 967 return 0; 968 969 /* Check for pattern 1a */ 970 if (strcmp(tosec, ".init.text") == 0 && 971 match(fromsec, PATTERNS(DATA_SECTIONS)) && 972 strstarts(fromsym, "__param_ops_")) 973 return 0; 974 975 /* symbols in data sections that may refer to any init/exit sections */ 976 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 977 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 978 match(fromsym, PATTERNS("*_ops", "*_ops.llvm.*", "*_console"))) 979 return 0; 980 981 /* Check for pattern 3 */ 982 if (strstarts(fromsec, ".head.text") && 983 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 984 return 0; 985 986 /* Check for pattern 4 */ 987 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 988 return 0; 989 990 /* Check for pattern 5 */ 991 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 992 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 993 match(fromsym, PATTERNS("*.constprop.*"))) 994 return 0; 995 996 return 1; 997 } 998 999 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 1000 unsigned int secndx) 1001 { 1002 return symsearch_find_nearest(elf, addr, secndx, false, ~0); 1003 } 1004 1005 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 1006 { 1007 Elf_Sym *new_sym; 1008 1009 /* If the supplied symbol has a valid name, return it */ 1010 if (is_valid_name(elf, sym)) 1011 return sym; 1012 1013 /* 1014 * Strive to find a better symbol name, but the resulting name may not 1015 * match the symbol referenced in the original code. 1016 */ 1017 new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym), 1018 true, 20); 1019 return new_sym ? new_sym : sym; 1020 } 1021 1022 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1023 { 1024 if (secndx >= elf->num_sections) 1025 return false; 1026 1027 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1028 } 1029 1030 static void default_mismatch_handler(struct module *mod, struct elf_info *elf, 1031 const struct sectioncheck* const mismatch, 1032 Elf_Sym *tsym, 1033 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1034 const char *tosec, Elf_Addr taddr) 1035 { 1036 Elf_Sym *from; 1037 const char *tosym; 1038 const char *fromsym; 1039 char taddr_str[16]; 1040 1041 from = find_fromsym(elf, faddr, fsecndx); 1042 fromsym = sym_name(elf, from); 1043 1044 tsym = find_tosym(elf, taddr, tsym); 1045 tosym = sym_name(elf, tsym); 1046 1047 /* check whitelist - we may ignore it */ 1048 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1049 return; 1050 1051 sec_mismatch_count++; 1052 1053 if (!tosym[0]) 1054 snprintf(taddr_str, sizeof(taddr_str), "0x%x", (unsigned int)taddr); 1055 1056 /* 1057 * The format for the reference source: <symbol_name>+<offset> or <address> 1058 * The format for the reference destination: <symbol_name> or <address> 1059 */ 1060 mod_warn(mod, "section mismatch in reference: %s%s0x%x (section: %s) -> %s (section: %s)\n", 1061 fromsym, fromsym[0] ? "+" : "", 1062 (unsigned int)(faddr - (fromsym[0] ? from->st_value : 0)), 1063 fromsec, tosym[0] ? tosym : taddr_str, tosec); 1064 1065 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1066 if (match(tosec, mismatch->bad_tosec)) 1067 fatal("The relocation at %s+0x%lx references\n" 1068 "section \"%s\" which is black-listed.\n" 1069 "Something is seriously wrong and should be fixed.\n" 1070 "You might get more information about where this is\n" 1071 "coming from by using scripts/check_extable.sh %s\n", 1072 fromsec, (long)faddr, tosec, mod->name); 1073 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1074 warn("The relocation at %s+0x%lx references\n" 1075 "section \"%s\" which is not in the list of\n" 1076 "authorized sections. If you're adding a new section\n" 1077 "and/or if this reference is valid, add \"%s\" to the\n" 1078 "list of authorized sections to jump to on fault.\n" 1079 "This can be achieved by adding \"%s\" to\n" 1080 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1081 fromsec, (long)faddr, tosec, tosec, tosec); 1082 else 1083 error("%s+0x%lx references non-executable section '%s'\n", 1084 fromsec, (long)faddr, tosec); 1085 } 1086 } 1087 1088 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1089 Elf_Addr faddr, const char *secname, 1090 Elf_Sym *sym) 1091 { 1092 static const char *prefix = "__export_symbol_"; 1093 const char *label_name, *name, *data; 1094 Elf_Sym *label; 1095 struct symbol *s; 1096 bool is_gpl; 1097 1098 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1099 label_name = sym_name(elf, label); 1100 1101 if (!strstarts(label_name, prefix)) { 1102 mod_error(mod, ".export_symbol section contains strange symbol '%s'\n", 1103 label_name); 1104 return; 1105 } 1106 1107 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1108 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1109 mod_error(mod, "local symbol '%s' was exported\n", 1110 label_name + strlen(prefix)); 1111 return; 1112 } 1113 1114 name = sym_name(elf, sym); 1115 if (strcmp(label_name + strlen(prefix), name)) { 1116 mod_error(mod, ".export_symbol section references '%s', but it does not seem to be an export symbol\n", 1117 name); 1118 return; 1119 } 1120 1121 data = sym_get_data(elf, label); /* license */ 1122 if (!strcmp(data, "GPL")) { 1123 is_gpl = true; 1124 } else if (!strcmp(data, "")) { 1125 is_gpl = false; 1126 } else { 1127 mod_error(mod, "unknown license '%s' was specified for '%s'\n", 1128 data, name); 1129 return; 1130 } 1131 1132 data += strlen(data) + 1; /* namespace */ 1133 s = sym_add_exported(name, mod, is_gpl, data); 1134 1135 /* 1136 * We need to be aware whether we are exporting a function or 1137 * a data on some architectures. 1138 */ 1139 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1140 1141 /* 1142 * For parisc64, symbols prefixed $$ from the library have the symbol type 1143 * STT_LOPROC. They should be handled as functions too. 1144 */ 1145 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1146 elf->hdr->e_machine == EM_PARISC && 1147 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1148 s->is_func = true; 1149 1150 if (match(secname, PATTERNS(ALL_INIT_SECTIONS))) 1151 mod_warn(mod, "EXPORT_SYMBOL used for init symbol '%s'. Remove __init or EXPORT_SYMBOL.\n", 1152 name); 1153 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS))) 1154 mod_warn(mod, "EXPORT_SYMBOL used for exit symbol '%s'. Remove __exit or EXPORT_SYMBOL.\n", 1155 name); 1156 } 1157 1158 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1159 Elf_Sym *sym, 1160 unsigned int fsecndx, const char *fromsec, 1161 Elf_Addr faddr, Elf_Addr taddr) 1162 { 1163 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1164 const struct sectioncheck *mismatch; 1165 1166 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1167 check_export_symbol(mod, elf, faddr, tosec, sym); 1168 return; 1169 } 1170 1171 mismatch = section_mismatch(fromsec, tosec); 1172 if (!mismatch) 1173 return; 1174 1175 default_mismatch_handler(mod, elf, mismatch, sym, 1176 fsecndx, fromsec, faddr, 1177 tosec, taddr); 1178 } 1179 1180 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1181 { 1182 switch (r_type) { 1183 case R_386_32: 1184 return get_unaligned_native(location); 1185 case R_386_PC32: 1186 return get_unaligned_native(location) + 4; 1187 } 1188 1189 return (Elf_Addr)(-1); 1190 } 1191 1192 static int32_t sign_extend32(int32_t value, int index) 1193 { 1194 uint8_t shift = 31 - index; 1195 1196 return (int32_t)(value << shift) >> shift; 1197 } 1198 1199 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1200 { 1201 uint32_t inst, upper, lower, sign, j1, j2; 1202 int32_t offset; 1203 1204 switch (r_type) { 1205 case R_ARM_ABS32: 1206 case R_ARM_REL32: 1207 inst = get_unaligned_native((uint32_t *)loc); 1208 return inst + sym->st_value; 1209 case R_ARM_MOVW_ABS_NC: 1210 case R_ARM_MOVT_ABS: 1211 inst = get_unaligned_native((uint32_t *)loc); 1212 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1213 15); 1214 return offset + sym->st_value; 1215 case R_ARM_PC24: 1216 case R_ARM_CALL: 1217 case R_ARM_JUMP24: 1218 inst = get_unaligned_native((uint32_t *)loc); 1219 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1220 return offset + sym->st_value + 8; 1221 case R_ARM_THM_MOVW_ABS_NC: 1222 case R_ARM_THM_MOVT_ABS: 1223 upper = get_unaligned_native((uint16_t *)loc); 1224 lower = get_unaligned_native((uint16_t *)loc + 1); 1225 offset = sign_extend32(((upper & 0x000f) << 12) | 1226 ((upper & 0x0400) << 1) | 1227 ((lower & 0x7000) >> 4) | 1228 (lower & 0x00ff), 1229 15); 1230 return offset + sym->st_value; 1231 case R_ARM_THM_JUMP19: 1232 /* 1233 * Encoding T3: 1234 * S = upper[10] 1235 * imm6 = upper[5:0] 1236 * J1 = lower[13] 1237 * J2 = lower[11] 1238 * imm11 = lower[10:0] 1239 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1240 */ 1241 upper = get_unaligned_native((uint16_t *)loc); 1242 lower = get_unaligned_native((uint16_t *)loc + 1); 1243 1244 sign = (upper >> 10) & 1; 1245 j1 = (lower >> 13) & 1; 1246 j2 = (lower >> 11) & 1; 1247 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1248 ((upper & 0x03f) << 12) | 1249 ((lower & 0x07ff) << 1), 1250 20); 1251 return offset + sym->st_value + 4; 1252 case R_ARM_THM_PC22: 1253 case R_ARM_THM_JUMP24: 1254 /* 1255 * Encoding T4: 1256 * S = upper[10] 1257 * imm10 = upper[9:0] 1258 * J1 = lower[13] 1259 * J2 = lower[11] 1260 * imm11 = lower[10:0] 1261 * I1 = NOT(J1 XOR S) 1262 * I2 = NOT(J2 XOR S) 1263 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1264 */ 1265 upper = get_unaligned_native((uint16_t *)loc); 1266 lower = get_unaligned_native((uint16_t *)loc + 1); 1267 1268 sign = (upper >> 10) & 1; 1269 j1 = (lower >> 13) & 1; 1270 j2 = (lower >> 11) & 1; 1271 offset = sign_extend32((sign << 24) | 1272 ((~(j1 ^ sign) & 1) << 23) | 1273 ((~(j2 ^ sign) & 1) << 22) | 1274 ((upper & 0x03ff) << 12) | 1275 ((lower & 0x07ff) << 1), 1276 24); 1277 return offset + sym->st_value + 4; 1278 } 1279 1280 return (Elf_Addr)(-1); 1281 } 1282 1283 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1284 { 1285 uint32_t inst; 1286 1287 inst = get_unaligned_native(location); 1288 switch (r_type) { 1289 case R_MIPS_LO16: 1290 return inst & 0xffff; 1291 case R_MIPS_26: 1292 return (inst & 0x03ffffff) << 2; 1293 case R_MIPS_32: 1294 return inst; 1295 } 1296 return (Elf_Addr)(-1); 1297 } 1298 1299 #ifndef EM_RISCV 1300 #define EM_RISCV 243 1301 #endif 1302 1303 #ifndef R_RISCV_SUB32 1304 #define R_RISCV_SUB32 39 1305 #endif 1306 1307 #ifndef EM_LOONGARCH 1308 #define EM_LOONGARCH 258 1309 #endif 1310 1311 #ifndef R_LARCH_SUB32 1312 #define R_LARCH_SUB32 55 1313 #endif 1314 1315 #ifndef R_LARCH_RELAX 1316 #define R_LARCH_RELAX 100 1317 #endif 1318 1319 #ifndef R_LARCH_ALIGN 1320 #define R_LARCH_ALIGN 102 1321 #endif 1322 1323 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1324 unsigned int *r_type, unsigned int *r_sym) 1325 { 1326 typedef struct { 1327 Elf64_Word r_sym; /* Symbol index */ 1328 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1329 unsigned char r_type3; /* 3rd relocation type */ 1330 unsigned char r_type2; /* 2nd relocation type */ 1331 unsigned char r_type; /* 1st relocation type */ 1332 } Elf64_Mips_R_Info; 1333 1334 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1335 1336 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1337 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1338 1339 *r_type = mips64_r_info->r_type; 1340 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1341 return; 1342 } 1343 1344 if (is_64bit) 1345 r_info = TO_NATIVE((Elf64_Xword)r_info); 1346 else 1347 r_info = TO_NATIVE((Elf32_Word)r_info); 1348 1349 *r_type = ELF_R_TYPE(r_info); 1350 *r_sym = ELF_R_SYM(r_info); 1351 } 1352 1353 static void section_rela(struct module *mod, struct elf_info *elf, 1354 unsigned int fsecndx, const char *fromsec, 1355 const Elf_Rela *start, const Elf_Rela *stop) 1356 { 1357 const Elf_Rela *rela; 1358 1359 for (rela = start; rela < stop; rela++) { 1360 Elf_Sym *tsym; 1361 Elf_Addr taddr, r_offset; 1362 unsigned int r_type, r_sym; 1363 1364 r_offset = TO_NATIVE(rela->r_offset); 1365 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1366 1367 tsym = elf->symtab_start + r_sym; 1368 taddr = tsym->st_value + TO_NATIVE(rela->r_addend); 1369 1370 switch (elf->hdr->e_machine) { 1371 case EM_RISCV: 1372 if (!strcmp("__ex_table", fromsec) && 1373 r_type == R_RISCV_SUB32) 1374 continue; 1375 break; 1376 case EM_LOONGARCH: 1377 switch (r_type) { 1378 case R_LARCH_SUB32: 1379 if (!strcmp("__ex_table", fromsec)) 1380 continue; 1381 break; 1382 case R_LARCH_RELAX: 1383 case R_LARCH_ALIGN: 1384 /* These relocs do not refer to symbols */ 1385 continue; 1386 } 1387 break; 1388 } 1389 1390 check_section_mismatch(mod, elf, tsym, 1391 fsecndx, fromsec, r_offset, taddr); 1392 } 1393 } 1394 1395 static void section_rel(struct module *mod, struct elf_info *elf, 1396 unsigned int fsecndx, const char *fromsec, 1397 const Elf_Rel *start, const Elf_Rel *stop) 1398 { 1399 const Elf_Rel *rel; 1400 1401 for (rel = start; rel < stop; rel++) { 1402 Elf_Sym *tsym; 1403 Elf_Addr taddr, r_offset; 1404 unsigned int r_type, r_sym; 1405 void *loc; 1406 1407 r_offset = TO_NATIVE(rel->r_offset); 1408 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1409 1410 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1411 tsym = elf->symtab_start + r_sym; 1412 1413 switch (elf->hdr->e_machine) { 1414 case EM_386: 1415 taddr = addend_386_rel(loc, r_type); 1416 break; 1417 case EM_ARM: 1418 taddr = addend_arm_rel(loc, tsym, r_type); 1419 break; 1420 case EM_MIPS: 1421 taddr = addend_mips_rel(loc, r_type); 1422 break; 1423 default: 1424 fatal("Please add code to calculate addend for this architecture\n"); 1425 } 1426 1427 check_section_mismatch(mod, elf, tsym, 1428 fsecndx, fromsec, r_offset, taddr); 1429 } 1430 } 1431 1432 /** 1433 * A module includes a number of sections that are discarded 1434 * either when loaded or when used as built-in. 1435 * For loaded modules all functions marked __init and all data 1436 * marked __initdata will be discarded when the module has been initialized. 1437 * Likewise for modules used built-in the sections marked __exit 1438 * are discarded because __exit marked function are supposed to be called 1439 * only when a module is unloaded which never happens for built-in modules. 1440 * The check_sec_ref() function traverses all relocation records 1441 * to find all references to a section that reference a section that will 1442 * be discarded and warns about it. 1443 **/ 1444 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1445 { 1446 int i; 1447 1448 /* Walk through all sections */ 1449 for (i = 0; i < elf->num_sections; i++) { 1450 Elf_Shdr *sechdr = &elf->sechdrs[i]; 1451 1452 check_section(mod, elf, sechdr); 1453 /* We want to process only relocation sections and not .init */ 1454 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) { 1455 /* section to which the relocation applies */ 1456 unsigned int secndx = sechdr->sh_info; 1457 const char *secname = sec_name(elf, secndx); 1458 const void *start, *stop; 1459 1460 /* If the section is known good, skip it */ 1461 if (match(secname, section_white_list)) 1462 continue; 1463 1464 start = sym_get_data_by_offset(elf, i, 0); 1465 stop = start + sechdr->sh_size; 1466 1467 if (sechdr->sh_type == SHT_RELA) 1468 section_rela(mod, elf, secndx, secname, 1469 start, stop); 1470 else 1471 section_rel(mod, elf, secndx, secname, 1472 start, stop); 1473 } 1474 } 1475 } 1476 1477 static char *remove_dot(char *s) 1478 { 1479 size_t n = strcspn(s, "."); 1480 1481 if (n && s[n]) { 1482 size_t m = strspn(s + n + 1, "0123456789"); 1483 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1484 s[n] = 0; 1485 } 1486 return s; 1487 } 1488 1489 /* 1490 * The CRCs are recorded in .*.cmd files in the form of: 1491 * #SYMVER <name> <crc> 1492 */ 1493 static void extract_crcs_for_object(const char *object, struct module *mod) 1494 { 1495 char cmd_file[PATH_MAX]; 1496 char *buf, *p; 1497 const char *base; 1498 int dirlen, baselen_without_suffix, ret; 1499 1500 base = get_basename(object); 1501 dirlen = base - object; 1502 1503 baselen_without_suffix = strlen(object) - dirlen - strlen(".o"); 1504 1505 /* 1506 * When CONFIG_LTO_CLANG_THIN_DIST=y, the ELF is *.thinlto-native.o 1507 * but the symbol CRCs are recorded in *.o.cmd file. 1508 */ 1509 if (strends(object, ".thinlto-native.o")) 1510 baselen_without_suffix -= strlen(".thinlto-native"); 1511 1512 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%.*s.o.cmd", 1513 dirlen, object, baselen_without_suffix, base); 1514 if (ret >= sizeof(cmd_file)) { 1515 error("%s: too long path was truncated\n", cmd_file); 1516 return; 1517 } 1518 1519 buf = read_text_file(cmd_file); 1520 p = buf; 1521 1522 while ((p = strstr(p, "\n#SYMVER "))) { 1523 char *name; 1524 size_t namelen; 1525 unsigned int crc; 1526 struct symbol *sym; 1527 1528 name = p + strlen("\n#SYMVER "); 1529 1530 p = strchr(name, ' '); 1531 if (!p) 1532 break; 1533 1534 namelen = p - name; 1535 p++; 1536 1537 if (!isdigit(*p)) 1538 continue; /* skip this line */ 1539 1540 crc = strtoul(p, &p, 0); 1541 if (*p != '\n') 1542 continue; /* skip this line */ 1543 1544 name[namelen] = '\0'; 1545 1546 /* 1547 * sym_find_with_module() may return NULL here. 1548 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1549 * Since commit e1327a127703, genksyms calculates CRCs of all 1550 * symbols, including trimmed ones. Ignore orphan CRCs. 1551 */ 1552 sym = sym_find_with_module(name, mod); 1553 if (sym) 1554 sym_set_crc(sym, crc); 1555 } 1556 1557 free(buf); 1558 } 1559 1560 /* 1561 * The symbol versions (CRC) are recorded in the .*.cmd files. 1562 * Parse them to retrieve CRCs for the current module. 1563 */ 1564 static void mod_set_crcs(struct module *mod) 1565 { 1566 char objlist[PATH_MAX]; 1567 char *buf, *p, *obj; 1568 int ret; 1569 1570 if (mod->is_vmlinux) { 1571 strcpy(objlist, ".vmlinux.objs"); 1572 } else { 1573 /* objects for a module are listed in the *.mod file. */ 1574 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1575 if (ret >= sizeof(objlist)) { 1576 error("%s: too long path was truncated\n", objlist); 1577 return; 1578 } 1579 } 1580 1581 buf = read_text_file(objlist); 1582 p = buf; 1583 1584 while ((obj = strsep(&p, "\n")) && obj[0]) 1585 extract_crcs_for_object(obj, mod); 1586 1587 free(buf); 1588 } 1589 1590 static void read_symbols(const char *modname) 1591 { 1592 const char *symname; 1593 char *version; 1594 char *license; 1595 char *namespace; 1596 struct module *mod; 1597 struct elf_info info = { }; 1598 Elf_Sym *sym; 1599 1600 if (!strends(modname, ".o")) { 1601 error("%s: filename must be suffixed with .o\n", modname); 1602 return; 1603 } 1604 1605 if (!parse_elf(&info, modname)) 1606 return; 1607 1608 /* strip trailing .o */ 1609 mod = new_module(modname, strlen(modname) - strlen(".o")); 1610 1611 /* save .no_trim_symbol section for later use */ 1612 if (info.no_trim_symbol_len) { 1613 mod->no_trim_symbol = xmalloc(info.no_trim_symbol_len); 1614 memcpy(mod->no_trim_symbol, info.no_trim_symbol, 1615 info.no_trim_symbol_len); 1616 mod->no_trim_symbol_len = info.no_trim_symbol_len; 1617 } 1618 1619 if (!mod->is_vmlinux) { 1620 license = get_modinfo(&info, "license"); 1621 if (!license) 1622 mod_error(mod, "missing MODULE_LICENSE()\n"); 1623 while (license) { 1624 if (!license_is_gpl_compatible(license)) { 1625 mod->is_gpl_compatible = false; 1626 break; 1627 } 1628 license = get_next_modinfo(&info, "license", license); 1629 } 1630 1631 for (namespace = get_modinfo(&info, "import_ns"); 1632 namespace; 1633 namespace = get_next_modinfo(&info, "import_ns", namespace)) { 1634 if (strstarts(namespace, MODULE_NS_PREFIX)) 1635 mod_error(mod, "explicitly importing namespace '%s' is not allowed.\n", 1636 namespace); 1637 1638 add_namespace(&mod->imported_namespaces, namespace); 1639 } 1640 1641 if (!get_modinfo(&info, "description")) 1642 mod_warn(mod, "missing MODULE_DESCRIPTION()\n"); 1643 } 1644 1645 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1646 symname = remove_dot(info.strtab + sym->st_name); 1647 1648 handle_symbol(mod, &info, sym, symname); 1649 handle_moddevtable(mod, &info, sym, symname); 1650 } 1651 1652 check_sec_ref(mod, &info); 1653 1654 if (!mod->is_vmlinux) { 1655 version = get_modinfo(&info, "version"); 1656 if (version || all_versions) 1657 get_src_version(mod->name, mod->srcversion, 1658 sizeof(mod->srcversion) - 1); 1659 } 1660 1661 parse_elf_finish(&info); 1662 1663 if (modversions) { 1664 /* 1665 * Our trick to get versioning for module struct etc. - it's 1666 * never passed as an argument to an exported function, so 1667 * the automatic versioning doesn't pick it up, but it's really 1668 * important anyhow. 1669 */ 1670 sym_add_unresolved("module_layout", mod, false); 1671 1672 mod_set_crcs(mod); 1673 } 1674 } 1675 1676 static void read_symbols_from_files(const char *filename) 1677 { 1678 FILE *in = stdin; 1679 char fname[PATH_MAX]; 1680 1681 in = fopen(filename, "r"); 1682 if (!in) 1683 fatal("Can't open filenames file %s: %m", filename); 1684 1685 while (fgets(fname, PATH_MAX, in) != NULL) { 1686 if (strends(fname, "\n")) 1687 fname[strlen(fname)-1] = '\0'; 1688 read_symbols(fname); 1689 } 1690 1691 fclose(in); 1692 } 1693 1694 #define SZ 500 1695 1696 /* We first write the generated file into memory using the 1697 * following helper, then compare to the file on disk and 1698 * only update the later if anything changed */ 1699 1700 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1701 const char *fmt, ...) 1702 { 1703 char tmp[SZ]; 1704 int len; 1705 va_list ap; 1706 1707 va_start(ap, fmt); 1708 len = vsnprintf(tmp, SZ, fmt, ap); 1709 va_end(ap); 1710 1711 if (len < 0) { 1712 perror("vsnprintf failed"); 1713 exit(1); 1714 } 1715 if (len >= SZ) 1716 fatal("buf_printf output truncated for string %s: %d bytes needed, %d available\n", 1717 tmp, len + 1, SZ); 1718 1719 buf_write(buf, tmp, len); 1720 } 1721 1722 void buf_write(struct buffer *buf, const char *s, int len) 1723 { 1724 if (buf->size - buf->pos < len) { 1725 buf->size += len + SZ; 1726 buf->p = xrealloc(buf->p, buf->size); 1727 } 1728 strncpy(buf->p + buf->pos, s, len); 1729 buf->pos += len; 1730 } 1731 1732 /** 1733 * verify_module_namespace() - does @modname have access to this symbol's @namespace 1734 * @namespace: export symbol namespace 1735 * @modname: module name 1736 * 1737 * If @namespace is prefixed with "module:" to indicate it is a module namespace 1738 * then test if @modname matches any of the comma separated patterns. 1739 * 1740 * The patterns only support tail-glob. 1741 */ 1742 static bool verify_module_namespace(const char *namespace, const char *modname) 1743 { 1744 size_t len, modlen = strlen(modname); 1745 const char *prefix = "module:"; 1746 const char *sep; 1747 bool glob; 1748 1749 if (!strstarts(namespace, prefix)) 1750 return false; 1751 1752 for (namespace += strlen(prefix); *namespace; namespace = sep) { 1753 sep = strchrnul(namespace, ','); 1754 len = sep - namespace; 1755 1756 glob = false; 1757 if (sep[-1] == '*') { 1758 len--; 1759 glob = true; 1760 } 1761 1762 if (*sep) 1763 sep++; 1764 1765 if (strncmp(namespace, modname, len) == 0 && (glob || len == modlen)) 1766 return true; 1767 } 1768 1769 return false; 1770 } 1771 1772 static void check_exports(struct module *mod) 1773 { 1774 struct symbol *s, *exp; 1775 1776 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1777 const char *basename; 1778 exp = find_symbol(s->name); 1779 if (!exp) { 1780 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1781 modpost_log(!warn_unresolved, mod, 1782 "symbol '%s' undefined!\n", 1783 s->name); 1784 continue; 1785 } 1786 if (exp->module == mod) { 1787 mod_error(mod, "symbol '%s' was exported without definition\n", s->name); 1788 continue; 1789 } 1790 1791 exp->used = true; 1792 s->module = exp->module; 1793 s->crc_valid = exp->crc_valid; 1794 s->crc = exp->crc; 1795 1796 basename = get_basename(mod->name); 1797 1798 if (!verify_module_namespace(exp->namespace, basename) && 1799 !contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1800 modpost_log(!allow_missing_ns_imports, mod, 1801 "module uses symbol '%s' from namespace '%s', but does not import it.\n", 1802 exp->name, exp->namespace); 1803 add_namespace(&mod->missing_namespaces, exp->namespace); 1804 } 1805 1806 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1807 mod_error(mod, "GPL-incompatible module uses GPL-only symbol '%s'\n", 1808 exp->name); 1809 } 1810 } 1811 1812 static void handle_white_list_exports(const char *white_list) 1813 { 1814 char *buf, *p, *name; 1815 1816 buf = read_text_file(white_list); 1817 p = buf; 1818 1819 while ((name = strsep(&p, "\n"))) { 1820 struct symbol *sym = find_symbol(name); 1821 1822 if (sym) 1823 sym->used = true; 1824 } 1825 1826 free(buf); 1827 } 1828 1829 /* 1830 * Keep symbols recorded in the .no_trim_symbol section. This is necessary to 1831 * prevent CONFIG_TRIM_UNUSED_KSYMS from dropping EXPORT_SYMBOL because 1832 * symbol_get() relies on the symbol being present in the ksymtab for lookups. 1833 */ 1834 static void keep_no_trim_symbols(struct module *mod) 1835 { 1836 unsigned long size = mod->no_trim_symbol_len; 1837 1838 for (char *s = mod->no_trim_symbol; s; s = next_string(s , &size)) { 1839 struct symbol *sym; 1840 1841 /* 1842 * If find_symbol() returns NULL, this symbol is not provided 1843 * by any module, and symbol_get() will fail. 1844 */ 1845 sym = find_symbol(s); 1846 if (sym) 1847 sym->used = true; 1848 } 1849 } 1850 1851 static void check_modname_len(struct module *mod) 1852 { 1853 const char *mod_name; 1854 1855 mod_name = get_basename(mod->name); 1856 1857 if (strlen(mod_name) >= MODULE_NAME_LEN) 1858 mod_error(mod, "module name is too long\n"); 1859 } 1860 1861 /** 1862 * Header for the generated file 1863 **/ 1864 static void add_header(struct buffer *b, struct module *mod) 1865 { 1866 buf_printf(b, "#include <linux/module.h>\n"); 1867 buf_printf(b, "#include <linux/export-internal.h>\n"); 1868 buf_printf(b, "#include <linux/compiler.h>\n"); 1869 buf_printf(b, "\n"); 1870 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1871 buf_printf(b, "\n"); 1872 buf_printf(b, "__visible struct module __this_module\n"); 1873 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1874 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1875 if (mod->has_init) 1876 buf_printf(b, "\t.init = init_module,\n"); 1877 if (mod->has_cleanup) 1878 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1879 "\t.exit = cleanup_module,\n" 1880 "#endif\n"); 1881 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1882 buf_printf(b, "};\n"); 1883 1884 if (!external_module) 1885 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1886 1887 if (strstarts(mod->name, "drivers/staging")) 1888 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1889 1890 if (strstarts(mod->name, "tools/testing")) 1891 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1892 } 1893 1894 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1895 { 1896 struct symbol *sym; 1897 1898 /* generate struct for exported symbols */ 1899 buf_printf(buf, "\n"); 1900 list_for_each_entry(sym, &mod->exported_symbols, list) { 1901 if (trim_unused_exports && !sym->used) 1902 continue; 1903 1904 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\");\n", 1905 sym->is_func ? "FUNC" : "DATA", sym->name, 1906 sym->namespace); 1907 1908 buf_printf(buf, "SYMBOL_FLAGS(%s, 0x%02x);\n", 1909 sym->name, get_symbol_flags(sym)); 1910 } 1911 1912 if (!modversions) 1913 return; 1914 1915 /* record CRCs for exported symbols */ 1916 buf_printf(buf, "\n"); 1917 list_for_each_entry(sym, &mod->exported_symbols, list) { 1918 if (trim_unused_exports && !sym->used) 1919 continue; 1920 1921 if (!sym->crc_valid) 1922 mod_warn(mod, "EXPORT symbol '%s' version generation failed, symbol will not be versioned.\n" 1923 "Is '%s' prototyped in <asm/asm-prototypes.h>?\n", 1924 sym->name, sym->name); 1925 1926 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x);\n", 1927 sym->name, sym->crc); 1928 } 1929 } 1930 1931 /** 1932 * Record CRCs for unresolved symbols, supporting long names 1933 */ 1934 static void add_extended_versions(struct buffer *b, struct module *mod) 1935 { 1936 struct symbol *s; 1937 1938 if (!extended_modversions) 1939 return; 1940 1941 buf_printf(b, "\n"); 1942 buf_printf(b, "static const u32 ____version_ext_crcs[]\n"); 1943 buf_printf(b, "__used __section(\"__version_ext_crcs\") = {\n"); 1944 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1945 if (!s->module) 1946 continue; 1947 if (!s->crc_valid) { 1948 mod_warn(mod, "symbol '%s' has no CRC!\n", s->name); 1949 continue; 1950 } 1951 buf_printf(b, "\t0x%08x,\n", s->crc); 1952 } 1953 buf_printf(b, "};\n"); 1954 1955 buf_printf(b, "static const char ____version_ext_names[]\n"); 1956 buf_printf(b, "__used __section(\"__version_ext_names\") =\n"); 1957 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1958 if (!s->module) 1959 continue; 1960 if (!s->crc_valid) 1961 /* 1962 * We already warned on this when producing the crc 1963 * table. 1964 * We need to skip its name too, as the indexes in 1965 * both tables need to align. 1966 */ 1967 continue; 1968 buf_printf(b, "\t\"%s\\0\"\n", s->name); 1969 } 1970 buf_printf(b, ";\n"); 1971 } 1972 1973 /** 1974 * Record CRCs for unresolved symbols 1975 **/ 1976 static void add_versions(struct buffer *b, struct module *mod) 1977 { 1978 struct symbol *s; 1979 1980 if (!basic_modversions) 1981 return; 1982 1983 buf_printf(b, "\n"); 1984 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1985 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1986 1987 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1988 if (!s->module) 1989 continue; 1990 if (!s->crc_valid) { 1991 mod_warn(mod, "symbol '%s' has no CRC!\n", s->name); 1992 continue; 1993 } 1994 if (strlen(s->name) >= MODULE_NAME_LEN) { 1995 if (extended_modversions) { 1996 /* this symbol will only be in the extended info */ 1997 continue; 1998 } else { 1999 mod_error(mod, "too long symbol '%s'\n", s->name); 2000 break; 2001 } 2002 } 2003 buf_printf(b, "\t{ 0x%08x, \"%s\" },\n", 2004 s->crc, s->name); 2005 } 2006 2007 buf_printf(b, "};\n"); 2008 } 2009 2010 static void add_depends(struct buffer *b, struct module *mod) 2011 { 2012 struct symbol *s; 2013 int first = 1; 2014 2015 /* Clear ->seen flag of modules that own symbols needed by this. */ 2016 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2017 if (s->module) 2018 s->module->seen = s->module->is_vmlinux; 2019 } 2020 2021 buf_printf(b, "\n"); 2022 buf_printf(b, "MODULE_INFO(depends, \""); 2023 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2024 const char *p; 2025 if (!s->module) 2026 continue; 2027 2028 if (s->module->seen) 2029 continue; 2030 2031 s->module->seen = true; 2032 p = get_basename(s->module->name); 2033 buf_printf(b, "%s%s", first ? "" : ",", p); 2034 first = 0; 2035 } 2036 buf_printf(b, "\");\n"); 2037 } 2038 2039 static void add_srcversion(struct buffer *b, struct module *mod) 2040 { 2041 if (mod->srcversion[0]) { 2042 buf_printf(b, "\n"); 2043 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 2044 mod->srcversion); 2045 } 2046 } 2047 2048 static void write_buf(struct buffer *b, const char *fname) 2049 { 2050 FILE *file; 2051 2052 if (error_occurred) 2053 return; 2054 2055 file = fopen(fname, "w"); 2056 if (!file) { 2057 perror(fname); 2058 exit(1); 2059 } 2060 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2061 perror(fname); 2062 exit(1); 2063 } 2064 if (fclose(file) != 0) { 2065 perror(fname); 2066 exit(1); 2067 } 2068 } 2069 2070 static void write_if_changed(struct buffer *b, const char *fname) 2071 { 2072 char *tmp; 2073 FILE *file; 2074 struct stat st; 2075 2076 file = fopen(fname, "r"); 2077 if (!file) 2078 goto write; 2079 2080 if (fstat(fileno(file), &st) < 0) 2081 goto close_write; 2082 2083 if (st.st_size != b->pos) 2084 goto close_write; 2085 2086 tmp = xmalloc(b->pos); 2087 if (fread(tmp, 1, b->pos, file) != b->pos) 2088 goto free_write; 2089 2090 if (memcmp(tmp, b->p, b->pos) != 0) 2091 goto free_write; 2092 2093 free(tmp); 2094 fclose(file); 2095 return; 2096 2097 free_write: 2098 free(tmp); 2099 close_write: 2100 fclose(file); 2101 write: 2102 write_buf(b, fname); 2103 } 2104 2105 static void write_vmlinux_export_c_file(struct module *mod) 2106 { 2107 struct buffer buf = { }; 2108 struct module_alias *alias, *next; 2109 2110 buf_printf(&buf, 2111 "#include <linux/export-internal.h>\n"); 2112 2113 add_exported_symbols(&buf, mod); 2114 2115 buf_printf(&buf, 2116 "#include <linux/module.h>\n" 2117 "#undef __MODULE_INFO_PREFIX\n" 2118 "#define __MODULE_INFO_PREFIX\n"); 2119 2120 list_for_each_entry_safe(alias, next, &mod->aliases, node) { 2121 buf_printf(&buf, "MODULE_INFO(%s.alias, \"%s\");\n", 2122 alias->builtin_modname, alias->str); 2123 list_del(&alias->node); 2124 free(alias->builtin_modname); 2125 free(alias); 2126 } 2127 2128 write_if_changed(&buf, ".vmlinux.export.c"); 2129 free(buf.p); 2130 } 2131 2132 /* do sanity checks, and generate *.mod.c file */ 2133 static void write_mod_c_file(struct module *mod) 2134 { 2135 struct buffer buf = { }; 2136 struct module_alias *alias, *next; 2137 char fname[PATH_MAX]; 2138 int ret; 2139 2140 add_header(&buf, mod); 2141 add_exported_symbols(&buf, mod); 2142 add_versions(&buf, mod); 2143 add_extended_versions(&buf, mod); 2144 add_depends(&buf, mod); 2145 2146 buf_printf(&buf, "\n"); 2147 list_for_each_entry_safe(alias, next, &mod->aliases, node) { 2148 buf_printf(&buf, "MODULE_ALIAS(\"%s\");\n", alias->str); 2149 list_del(&alias->node); 2150 free(alias); 2151 } 2152 2153 add_srcversion(&buf, mod); 2154 2155 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2156 if (ret >= sizeof(fname)) { 2157 error("%s: too long path was truncated\n", fname); 2158 goto free; 2159 } 2160 2161 write_if_changed(&buf, fname); 2162 2163 free: 2164 free(buf.p); 2165 } 2166 2167 /* parse Module.symvers file. line format: 2168 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2169 **/ 2170 static void read_dump(const char *fname) 2171 { 2172 char *buf, *pos, *line; 2173 2174 buf = read_text_file(fname); 2175 if (!buf) 2176 /* No symbol versions, silently ignore */ 2177 return; 2178 2179 pos = buf; 2180 2181 while ((line = get_line(&pos))) { 2182 char *symname, *namespace, *modname, *d, *export; 2183 unsigned int crc; 2184 struct module *mod; 2185 struct symbol *s; 2186 bool gpl_only; 2187 2188 if (!(symname = strchr(line, '\t'))) 2189 goto fail; 2190 *symname++ = '\0'; 2191 if (!(modname = strchr(symname, '\t'))) 2192 goto fail; 2193 *modname++ = '\0'; 2194 if (!(export = strchr(modname, '\t'))) 2195 goto fail; 2196 *export++ = '\0'; 2197 if (!(namespace = strchr(export, '\t'))) 2198 goto fail; 2199 *namespace++ = '\0'; 2200 2201 crc = strtoul(line, &d, 16); 2202 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2203 goto fail; 2204 2205 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2206 gpl_only = true; 2207 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2208 gpl_only = false; 2209 } else { 2210 error("%s: unknown license %s. skip", symname, export); 2211 continue; 2212 } 2213 2214 mod = find_module(fname, modname); 2215 if (!mod) { 2216 mod = new_module(modname, strlen(modname)); 2217 mod->dump_file = fname; 2218 } 2219 s = sym_add_exported(symname, mod, gpl_only, namespace); 2220 sym_set_crc(s, crc); 2221 } 2222 free(buf); 2223 return; 2224 fail: 2225 free(buf); 2226 fatal("parse error in symbol dump file\n"); 2227 } 2228 2229 static void write_dump(const char *fname) 2230 { 2231 struct buffer buf = { }; 2232 struct module *mod; 2233 struct symbol *sym; 2234 2235 list_for_each_entry(mod, &modules, list) { 2236 if (mod->dump_file) 2237 continue; 2238 list_for_each_entry(sym, &mod->exported_symbols, list) { 2239 if (trim_unused_exports && !sym->used) 2240 continue; 2241 2242 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2243 sym->crc, sym->name, mod->name, 2244 sym->is_gpl_only ? "_GPL" : "", 2245 sym->namespace); 2246 } 2247 } 2248 write_buf(&buf, fname); 2249 free(buf.p); 2250 } 2251 2252 static void write_namespace_deps_files(const char *fname) 2253 { 2254 struct module *mod; 2255 struct namespace_list *ns; 2256 struct buffer ns_deps_buf = {}; 2257 2258 list_for_each_entry(mod, &modules, list) { 2259 2260 if (mod->dump_file || list_empty(&mod->missing_namespaces)) 2261 continue; 2262 2263 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2264 2265 list_for_each_entry(ns, &mod->missing_namespaces, list) 2266 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2267 2268 buf_printf(&ns_deps_buf, "\n"); 2269 } 2270 2271 write_if_changed(&ns_deps_buf, fname); 2272 free(ns_deps_buf.p); 2273 } 2274 2275 struct dump_list { 2276 struct list_head list; 2277 const char *file; 2278 }; 2279 2280 static void check_host_endian(void) 2281 { 2282 static const union { 2283 short s; 2284 char c[2]; 2285 } endian_test = { .c = {0x01, 0x02} }; 2286 2287 switch (endian_test.s) { 2288 case 0x0102: 2289 host_is_big_endian = true; 2290 break; 2291 case 0x0201: 2292 host_is_big_endian = false; 2293 break; 2294 default: 2295 fatal("Unknown host endian\n"); 2296 } 2297 } 2298 2299 int main(int argc, char **argv) 2300 { 2301 struct module *mod; 2302 char *missing_namespace_deps = NULL; 2303 char *unused_exports_white_list = NULL; 2304 char *dump_write = NULL, *files_source = NULL; 2305 int opt; 2306 LIST_HEAD(dump_lists); 2307 struct dump_list *dl, *dl2; 2308 2309 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:xb")) != -1) { 2310 switch (opt) { 2311 case 'e': 2312 external_module = true; 2313 break; 2314 case 'i': 2315 dl = xmalloc(sizeof(*dl)); 2316 dl->file = optarg; 2317 list_add_tail(&dl->list, &dump_lists); 2318 break; 2319 case 'M': 2320 module_enabled = true; 2321 break; 2322 case 'm': 2323 modversions = true; 2324 break; 2325 case 'n': 2326 ignore_missing_files = true; 2327 break; 2328 case 'o': 2329 dump_write = optarg; 2330 break; 2331 case 'a': 2332 all_versions = true; 2333 break; 2334 case 'T': 2335 files_source = optarg; 2336 break; 2337 case 't': 2338 trim_unused_exports = true; 2339 break; 2340 case 'u': 2341 unused_exports_white_list = optarg; 2342 break; 2343 case 'W': 2344 extra_warn = true; 2345 break; 2346 case 'w': 2347 warn_unresolved = true; 2348 break; 2349 case 'E': 2350 sec_mismatch_warn_only = false; 2351 break; 2352 case 'N': 2353 allow_missing_ns_imports = true; 2354 break; 2355 case 'd': 2356 missing_namespace_deps = optarg; 2357 break; 2358 case 'b': 2359 basic_modversions = true; 2360 break; 2361 case 'x': 2362 extended_modversions = true; 2363 break; 2364 default: 2365 exit(1); 2366 } 2367 } 2368 2369 check_host_endian(); 2370 2371 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2372 read_dump(dl->file); 2373 list_del(&dl->list); 2374 free(dl); 2375 } 2376 2377 while (optind < argc) 2378 read_symbols(argv[optind++]); 2379 2380 if (files_source) 2381 read_symbols_from_files(files_source); 2382 2383 list_for_each_entry(mod, &modules, list) { 2384 keep_no_trim_symbols(mod); 2385 2386 if (mod->dump_file || mod->is_vmlinux) 2387 continue; 2388 2389 check_modname_len(mod); 2390 check_exports(mod); 2391 } 2392 2393 if (unused_exports_white_list) 2394 handle_white_list_exports(unused_exports_white_list); 2395 2396 list_for_each_entry(mod, &modules, list) { 2397 if (mod->dump_file) 2398 continue; 2399 2400 if (mod->is_vmlinux) 2401 write_vmlinux_export_c_file(mod); 2402 else 2403 write_mod_c_file(mod); 2404 } 2405 2406 if (missing_namespace_deps) 2407 write_namespace_deps_files(missing_namespace_deps); 2408 2409 if (dump_write) 2410 write_dump(dump_write); 2411 if (sec_mismatch_count && !sec_mismatch_warn_only) 2412 error("Section mismatches detected.\n" 2413 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2414 2415 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2416 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2417 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2418 2419 return error_occurred ? 1 : 0; 2420 } 2421