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#include "modpost.h" 24#include "../../include/linux/license.h" 25#include "../../include/linux/module_symbol.h" 26 27static bool module_enabled; 28/* Are we using CONFIG_MODVERSIONS? */ 29static bool modversions; 30/* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 31static bool all_versions; 32/* If we are modposting external module set to 1 */ 33static bool external_module; 34/* Only warn about unresolved symbols */ 35static bool warn_unresolved; 36 37static int sec_mismatch_count; 38static bool sec_mismatch_warn_only = true; 39/* Trim EXPORT_SYMBOLs that are unused by in-tree modules */ 40static bool trim_unused_exports; 41 42/* ignore missing files */ 43static bool ignore_missing_files; 44/* If set to 1, only warn (instead of error) about missing ns imports */ 45static bool allow_missing_ns_imports; 46 47static bool error_occurred; 48 49static bool extra_warn; 50 51/* 52 * Cut off the warnings when there are too many. This typically occurs when 53 * vmlinux is missing. ('make modules' without building vmlinux.) 54 */ 55#define MAX_UNRESOLVED_REPORTS 10 56static unsigned int nr_unresolved; 57 58/* In kernel, this size is defined in linux/module.h; 59 * here we use Elf_Addr instead of long for covering cross-compile 60 */ 61 62#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) 63 64void __attribute__((format(printf, 2, 3))) 65modpost_log(enum loglevel loglevel, const char *fmt, ...) 66{ 67 va_list arglist; 68 69 switch (loglevel) { 70 case LOG_WARN: 71 fprintf(stderr, "WARNING: "); 72 break; 73 case LOG_ERROR: 74 fprintf(stderr, "ERROR: "); 75 break; 76 case LOG_FATAL: 77 fprintf(stderr, "FATAL: "); 78 break; 79 default: /* invalid loglevel, ignore */ 80 break; 81 } 82 83 fprintf(stderr, "modpost: "); 84 85 va_start(arglist, fmt); 86 vfprintf(stderr, fmt, arglist); 87 va_end(arglist); 88 89 if (loglevel == LOG_FATAL) 90 exit(1); 91 if (loglevel == LOG_ERROR) 92 error_occurred = true; 93} 94 95static inline bool strends(const char *str, const char *postfix) 96{ 97 if (strlen(str) < strlen(postfix)) 98 return false; 99 100 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; 101} 102 103void *do_nofail(void *ptr, const char *expr) 104{ 105 if (!ptr) 106 fatal("Memory allocation failure: %s.\n", expr); 107 108 return ptr; 109} 110 111char *read_text_file(const char *filename) 112{ 113 struct stat st; 114 size_t nbytes; 115 int fd; 116 char *buf; 117 118 fd = open(filename, O_RDONLY); 119 if (fd < 0) { 120 perror(filename); 121 exit(1); 122 } 123 124 if (fstat(fd, &st) < 0) { 125 perror(filename); 126 exit(1); 127 } 128 129 buf = NOFAIL(malloc(st.st_size + 1)); 130 131 nbytes = st.st_size; 132 133 while (nbytes) { 134 ssize_t bytes_read; 135 136 bytes_read = read(fd, buf, nbytes); 137 if (bytes_read < 0) { 138 perror(filename); 139 exit(1); 140 } 141 142 nbytes -= bytes_read; 143 } 144 buf[st.st_size] = '\0'; 145 146 close(fd); 147 148 return buf; 149} 150 151char *get_line(char **stringp) 152{ 153 char *orig = *stringp, *next; 154 155 /* do not return the unwanted extra line at EOF */ 156 if (!orig || *orig == '\0') 157 return NULL; 158 159 /* don't use strsep here, it is not available everywhere */ 160 next = strchr(orig, '\n'); 161 if (next) 162 *next++ = '\0'; 163 164 *stringp = next; 165 166 return orig; 167} 168 169/* A list of all modules we processed */ 170LIST_HEAD(modules); 171 172static struct module *find_module(const char *modname) 173{ 174 struct module *mod; 175 176 list_for_each_entry(mod, &modules, list) { 177 if (strcmp(mod->name, modname) == 0) 178 return mod; 179 } 180 return NULL; 181} 182 183static struct module *new_module(const char *name, size_t namelen) 184{ 185 struct module *mod; 186 187 mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1)); 188 memset(mod, 0, sizeof(*mod)); 189 190 INIT_LIST_HEAD(&mod->exported_symbols); 191 INIT_LIST_HEAD(&mod->unresolved_symbols); 192 INIT_LIST_HEAD(&mod->missing_namespaces); 193 INIT_LIST_HEAD(&mod->imported_namespaces); 194 195 memcpy(mod->name, name, namelen); 196 mod->name[namelen] = '\0'; 197 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0); 198 199 /* 200 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE() 201 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue 202 * modpost will exit wiht error anyway. 203 */ 204 mod->is_gpl_compatible = true; 205 206 list_add_tail(&mod->list, &modules); 207 208 return mod; 209} 210 211/* A hash of all exported symbols, 212 * struct symbol is also used for lists of unresolved symbols */ 213 214#define SYMBOL_HASH_SIZE 1024 215 216struct symbol { 217 struct symbol *next; 218 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */ 219 struct module *module; 220 char *namespace; 221 unsigned int crc; 222 bool crc_valid; 223 bool weak; 224 bool is_func; 225 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ 226 bool used; /* there exists a user of this symbol */ 227 char name[]; 228}; 229 230static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 231 232/* This is based on the hash algorithm from gdbm, via tdb */ 233static inline unsigned int tdb_hash(const char *name) 234{ 235 unsigned value; /* Used to compute the hash value. */ 236 unsigned i; /* Used to cycle through random values. */ 237 238 /* Set the initial value from the key size. */ 239 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++) 240 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 241 242 return (1103515243 * value + 12345); 243} 244 245/** 246 * Allocate a new symbols for use in the hash of exported symbols or 247 * the list of unresolved symbols per module 248 **/ 249static struct symbol *alloc_symbol(const char *name) 250{ 251 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 252 253 memset(s, 0, sizeof(*s)); 254 strcpy(s->name, name); 255 256 return s; 257} 258 259/* For the hash of exported symbols */ 260static void hash_add_symbol(struct symbol *sym) 261{ 262 unsigned int hash; 263 264 hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE; 265 sym->next = symbolhash[hash]; 266 symbolhash[hash] = sym; 267} 268 269static void sym_add_unresolved(const char *name, struct module *mod, bool weak) 270{ 271 struct symbol *sym; 272 273 sym = alloc_symbol(name); 274 sym->weak = weak; 275 276 list_add_tail(&sym->list, &mod->unresolved_symbols); 277} 278 279static struct symbol *sym_find_with_module(const char *name, struct module *mod) 280{ 281 struct symbol *s; 282 283 /* For our purposes, .foo matches foo. PPC64 needs this. */ 284 if (name[0] == '.') 285 name++; 286 287 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) { 288 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) 289 return s; 290 } 291 return NULL; 292} 293 294static struct symbol *find_symbol(const char *name) 295{ 296 return sym_find_with_module(name, NULL); 297} 298 299struct namespace_list { 300 struct list_head list; 301 char namespace[]; 302}; 303 304static bool contains_namespace(struct list_head *head, const char *namespace) 305{ 306 struct namespace_list *list; 307 308 /* 309 * The default namespace is null string "", which is always implicitly 310 * contained. 311 */ 312 if (!namespace[0]) 313 return true; 314 315 list_for_each_entry(list, head, list) { 316 if (!strcmp(list->namespace, namespace)) 317 return true; 318 } 319 320 return false; 321} 322 323static void add_namespace(struct list_head *head, const char *namespace) 324{ 325 struct namespace_list *ns_entry; 326 327 if (!contains_namespace(head, namespace)) { 328 ns_entry = NOFAIL(malloc(sizeof(*ns_entry) + 329 strlen(namespace) + 1)); 330 strcpy(ns_entry->namespace, namespace); 331 list_add_tail(&ns_entry->list, head); 332 } 333} 334 335static void *sym_get_data_by_offset(const struct elf_info *info, 336 unsigned int secindex, unsigned long offset) 337{ 338 Elf_Shdr *sechdr = &info->sechdrs[secindex]; 339 340 return (void *)info->hdr + sechdr->sh_offset + offset; 341} 342 343void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) 344{ 345 return sym_get_data_by_offset(info, get_secindex(info, sym), 346 sym->st_value); 347} 348 349static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) 350{ 351 return sym_get_data_by_offset(info, info->secindex_strings, 352 sechdr->sh_name); 353} 354 355static const char *sec_name(const struct elf_info *info, unsigned int secindex) 356{ 357 /* 358 * If sym->st_shndx is a special section index, there is no 359 * corresponding section header. 360 * Return "" if the index is out of range of info->sechdrs[] array. 361 */ 362 if (secindex >= info->num_sections) 363 return ""; 364 365 return sech_name(info, &info->sechdrs[secindex]); 366} 367 368#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) 369 370static struct symbol *sym_add_exported(const char *name, struct module *mod, 371 bool gpl_only, const char *namespace) 372{ 373 struct symbol *s = find_symbol(name); 374 375 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { 376 error("%s: '%s' exported twice. Previous export was in %s%s\n", 377 mod->name, name, s->module->name, 378 s->module->is_vmlinux ? "" : ".ko"); 379 } 380 381 s = alloc_symbol(name); 382 s->module = mod; 383 s->is_gpl_only = gpl_only; 384 s->namespace = NOFAIL(strdup(namespace)); 385 list_add_tail(&s->list, &mod->exported_symbols); 386 hash_add_symbol(s); 387 388 return s; 389} 390 391static void sym_set_crc(struct symbol *sym, unsigned int crc) 392{ 393 sym->crc = crc; 394 sym->crc_valid = true; 395} 396 397static void *grab_file(const char *filename, size_t *size) 398{ 399 struct stat st; 400 void *map = MAP_FAILED; 401 int fd; 402 403 fd = open(filename, O_RDONLY); 404 if (fd < 0) 405 return NULL; 406 if (fstat(fd, &st)) 407 goto failed; 408 409 *size = st.st_size; 410 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 411 412failed: 413 close(fd); 414 if (map == MAP_FAILED) 415 return NULL; 416 return map; 417} 418 419static void release_file(void *file, size_t size) 420{ 421 munmap(file, size); 422} 423 424static int parse_elf(struct elf_info *info, const char *filename) 425{ 426 unsigned int i; 427 Elf_Ehdr *hdr; 428 Elf_Shdr *sechdrs; 429 Elf_Sym *sym; 430 const char *secstrings; 431 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 432 433 hdr = grab_file(filename, &info->size); 434 if (!hdr) { 435 if (ignore_missing_files) { 436 fprintf(stderr, "%s: %s (ignored)\n", filename, 437 strerror(errno)); 438 return 0; 439 } 440 perror(filename); 441 exit(1); 442 } 443 info->hdr = hdr; 444 if (info->size < sizeof(*hdr)) { 445 /* file too small, assume this is an empty .o file */ 446 return 0; 447 } 448 /* Is this a valid ELF file? */ 449 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 450 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 451 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 452 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 453 /* Not an ELF file - silently ignore it */ 454 return 0; 455 } 456 /* Fix endianness in ELF header */ 457 hdr->e_type = TO_NATIVE(hdr->e_type); 458 hdr->e_machine = TO_NATIVE(hdr->e_machine); 459 hdr->e_version = TO_NATIVE(hdr->e_version); 460 hdr->e_entry = TO_NATIVE(hdr->e_entry); 461 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 462 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 463 hdr->e_flags = TO_NATIVE(hdr->e_flags); 464 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 465 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 466 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 467 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 468 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 469 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 470 sechdrs = (void *)hdr + hdr->e_shoff; 471 info->sechdrs = sechdrs; 472 473 /* modpost only works for relocatable objects */ 474 if (hdr->e_type != ET_REL) 475 fatal("%s: not relocatable object.", filename); 476 477 /* Check if file offset is correct */ 478 if (hdr->e_shoff > info->size) { 479 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", 480 (unsigned long)hdr->e_shoff, filename, info->size); 481 return 0; 482 } 483 484 if (hdr->e_shnum == SHN_UNDEF) { 485 /* 486 * There are more than 64k sections, 487 * read count from .sh_size. 488 */ 489 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 490 } 491 else { 492 info->num_sections = hdr->e_shnum; 493 } 494 if (hdr->e_shstrndx == SHN_XINDEX) { 495 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 496 } 497 else { 498 info->secindex_strings = hdr->e_shstrndx; 499 } 500 501 /* Fix endianness in section headers */ 502 for (i = 0; i < info->num_sections; i++) { 503 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 504 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 505 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 506 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 507 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 508 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 509 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 510 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 511 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 512 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 513 } 514 /* Find symbol table. */ 515 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 516 for (i = 1; i < info->num_sections; i++) { 517 const char *secname; 518 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 519 520 if (!nobits && sechdrs[i].sh_offset > info->size) { 521 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n", 522 filename, (unsigned long)sechdrs[i].sh_offset, 523 sizeof(*hdr)); 524 return 0; 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 } 535 536 if (sechdrs[i].sh_type == SHT_SYMTAB) { 537 unsigned int sh_link_idx; 538 symtab_idx = i; 539 info->symtab_start = (void *)hdr + 540 sechdrs[i].sh_offset; 541 info->symtab_stop = (void *)hdr + 542 sechdrs[i].sh_offset + sechdrs[i].sh_size; 543 sh_link_idx = sechdrs[i].sh_link; 544 info->strtab = (void *)hdr + 545 sechdrs[sh_link_idx].sh_offset; 546 } 547 548 /* 32bit section no. table? ("more than 64k sections") */ 549 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 550 symtab_shndx_idx = i; 551 info->symtab_shndx_start = (void *)hdr + 552 sechdrs[i].sh_offset; 553 info->symtab_shndx_stop = (void *)hdr + 554 sechdrs[i].sh_offset + sechdrs[i].sh_size; 555 } 556 } 557 if (!info->symtab_start) 558 fatal("%s has no symtab?\n", filename); 559 560 /* Fix endianness in symbols */ 561 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 562 sym->st_shndx = TO_NATIVE(sym->st_shndx); 563 sym->st_name = TO_NATIVE(sym->st_name); 564 sym->st_value = TO_NATIVE(sym->st_value); 565 sym->st_size = TO_NATIVE(sym->st_size); 566 } 567 568 if (symtab_shndx_idx != ~0U) { 569 Elf32_Word *p; 570 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 571 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 572 filename, sechdrs[symtab_shndx_idx].sh_link, 573 symtab_idx); 574 /* Fix endianness */ 575 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 576 p++) 577 *p = TO_NATIVE(*p); 578 } 579 580 return 1; 581} 582 583static void parse_elf_finish(struct elf_info *info) 584{ 585 release_file(info->hdr, info->size); 586} 587 588static int ignore_undef_symbol(struct elf_info *info, const char *symname) 589{ 590 /* ignore __this_module, it will be resolved shortly */ 591 if (strcmp(symname, "__this_module") == 0) 592 return 1; 593 /* ignore global offset table */ 594 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 595 return 1; 596 if (info->hdr->e_machine == EM_PPC) 597 /* Special register function linked on all modules during final link of .ko */ 598 if (strstarts(symname, "_restgpr_") || 599 strstarts(symname, "_savegpr_") || 600 strstarts(symname, "_rest32gpr_") || 601 strstarts(symname, "_save32gpr_") || 602 strstarts(symname, "_restvr_") || 603 strstarts(symname, "_savevr_")) 604 return 1; 605 if (info->hdr->e_machine == EM_PPC64) 606 /* Special register function linked on all modules during final link of .ko */ 607 if (strstarts(symname, "_restgpr0_") || 608 strstarts(symname, "_savegpr0_") || 609 strstarts(symname, "_restvr_") || 610 strstarts(symname, "_savevr_") || 611 strcmp(symname, ".TOC.") == 0) 612 return 1; 613 614 if (info->hdr->e_machine == EM_S390) 615 /* Expoline thunks are linked on all kernel modules during final link of .ko */ 616 if (strstarts(symname, "__s390_indirect_jump_r")) 617 return 1; 618 /* Do not ignore this symbol */ 619 return 0; 620} 621 622static void handle_symbol(struct module *mod, struct elf_info *info, 623 const Elf_Sym *sym, const char *symname) 624{ 625 switch (sym->st_shndx) { 626 case SHN_COMMON: 627 if (strstarts(symname, "__gnu_lto_")) { 628 /* Should warn here, but modpost runs before the linker */ 629 } else 630 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 631 break; 632 case SHN_UNDEF: 633 /* undefined symbol */ 634 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 635 ELF_ST_BIND(sym->st_info) != STB_WEAK) 636 break; 637 if (ignore_undef_symbol(info, symname)) 638 break; 639 if (info->hdr->e_machine == EM_SPARC || 640 info->hdr->e_machine == EM_SPARCV9) { 641 /* Ignore register directives. */ 642 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 643 break; 644 if (symname[0] == '.') { 645 char *munged = NOFAIL(strdup(symname)); 646 munged[0] = '_'; 647 munged[1] = toupper(munged[1]); 648 symname = munged; 649 } 650 } 651 652 sym_add_unresolved(symname, mod, 653 ELF_ST_BIND(sym->st_info) == STB_WEAK); 654 break; 655 default: 656 if (strcmp(symname, "init_module") == 0) 657 mod->has_init = true; 658 if (strcmp(symname, "cleanup_module") == 0) 659 mod->has_cleanup = true; 660 break; 661 } 662} 663 664/** 665 * Parse tag=value strings from .modinfo section 666 **/ 667static char *next_string(char *string, unsigned long *secsize) 668{ 669 /* Skip non-zero chars */ 670 while (string[0]) { 671 string++; 672 if ((*secsize)-- <= 1) 673 return NULL; 674 } 675 676 /* Skip any zero padding. */ 677 while (!string[0]) { 678 string++; 679 if ((*secsize)-- <= 1) 680 return NULL; 681 } 682 return string; 683} 684 685static char *get_next_modinfo(struct elf_info *info, const char *tag, 686 char *prev) 687{ 688 char *p; 689 unsigned int taglen = strlen(tag); 690 char *modinfo = info->modinfo; 691 unsigned long size = info->modinfo_len; 692 693 if (prev) { 694 size -= prev - modinfo; 695 modinfo = next_string(prev, &size); 696 } 697 698 for (p = modinfo; p; p = next_string(p, &size)) { 699 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 700 return p + taglen + 1; 701 } 702 return NULL; 703} 704 705static char *get_modinfo(struct elf_info *info, const char *tag) 706 707{ 708 return get_next_modinfo(info, tag, NULL); 709} 710 711static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 712{ 713 if (sym) 714 return elf->strtab + sym->st_name; 715 else 716 return "(unknown)"; 717} 718 719/* 720 * Check whether the 'string' argument matches one of the 'patterns', 721 * an array of shell wildcard patterns (glob). 722 * 723 * Return true is there is a match. 724 */ 725static bool match(const char *string, const char *const patterns[]) 726{ 727 const char *pattern; 728 729 while ((pattern = *patterns++)) { 730 if (!fnmatch(pattern, string, 0)) 731 return true; 732 } 733 734 return false; 735} 736 737/* useful to pass patterns to match() directly */ 738#define PATTERNS(...) \ 739 ({ \ 740 static const char *const patterns[] = {__VA_ARGS__, NULL}; \ 741 patterns; \ 742 }) 743 744/* sections that we do not want to do full section mismatch check on */ 745static const char *const section_white_list[] = 746{ 747 ".comment*", 748 ".debug*", 749 ".zdebug*", /* Compressed debug sections. */ 750 ".GCC.command.line", /* record-gcc-switches */ 751 ".mdebug*", /* alpha, score, mips etc. */ 752 ".pdr", /* alpha, score, mips etc. */ 753 ".stab*", 754 ".note*", 755 ".got*", 756 ".toc*", 757 ".xt.prop", /* xtensa */ 758 ".xt.lit", /* xtensa */ 759 ".arcextmap*", /* arc */ 760 ".gnu.linkonce.arcext*", /* arc : modules */ 761 ".cmem*", /* EZchip */ 762 ".fmt_slot*", /* EZchip */ 763 ".gnu.lto*", 764 ".discard.*", 765 ".llvm.call-graph-profile", /* call graph */ 766 NULL 767}; 768 769/* 770 * This is used to find sections missing the SHF_ALLOC flag. 771 * The cause of this is often a section specified in assembler 772 * without "ax" / "aw". 773 */ 774static void check_section(const char *modname, struct elf_info *elf, 775 Elf_Shdr *sechdr) 776{ 777 const char *sec = sech_name(elf, sechdr); 778 779 if (sechdr->sh_type == SHT_PROGBITS && 780 !(sechdr->sh_flags & SHF_ALLOC) && 781 !match(sec, section_white_list)) { 782 warn("%s (%s): unexpected non-allocatable section.\n" 783 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 784 "Note that for example <linux/init.h> contains\n" 785 "section definitions for use in .S files.\n\n", 786 modname, sec); 787 } 788} 789 790 791 792#define ALL_INIT_DATA_SECTIONS \ 793 ".init.setup", ".init.rodata", ".meminit.rodata", \ 794 ".init.data", ".meminit.data" 795#define ALL_EXIT_DATA_SECTIONS \ 796 ".exit.data", ".memexit.data" 797 798#define ALL_INIT_TEXT_SECTIONS \ 799 ".init.text", ".meminit.text" 800#define ALL_EXIT_TEXT_SECTIONS \ 801 ".exit.text" 802 803#define ALL_PCI_INIT_SECTIONS \ 804 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 805 ".pci_fixup_enable", ".pci_fixup_resume", \ 806 ".pci_fixup_resume_early", ".pci_fixup_suspend" 807 808#define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS 809 810#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 811#define ALL_EXIT_SECTIONS EXIT_SECTIONS 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" 820 821#define INIT_SECTIONS ".init.*" 822#define MEM_INIT_SECTIONS ".meminit.*" 823 824#define EXIT_SECTIONS ".exit.*" 825 826#define ALL_TEXT_SECTIONS ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \ 827 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 828 829enum mismatch { 830 TEXT_TO_ANY_INIT, 831 DATA_TO_ANY_INIT, 832 TEXTDATA_TO_ANY_EXIT, 833 XXXINIT_TO_SOME_INIT, 834 ANY_INIT_TO_ANY_EXIT, 835 ANY_EXIT_TO_ANY_INIT, 836 EXTABLE_TO_NON_TEXT, 837}; 838 839/** 840 * Describe how to match sections on different criteria: 841 * 842 * @fromsec: Array of sections to be matched. 843 * 844 * @bad_tosec: Relocations applied to a section in @fromsec to a section in 845 * this array is forbidden (black-list). Can be empty. 846 * 847 * @good_tosec: Relocations applied to a section in @fromsec must be 848 * targeting sections in this array (white-list). Can be empty. 849 * 850 * @mismatch: Type of mismatch. 851 */ 852struct sectioncheck { 853 const char *fromsec[20]; 854 const char *bad_tosec[20]; 855 const char *good_tosec[20]; 856 enum mismatch mismatch; 857}; 858 859static const struct sectioncheck sectioncheck[] = { 860/* Do not reference init/exit code/data from 861 * normal code and data 862 */ 863{ 864 .fromsec = { TEXT_SECTIONS, NULL }, 865 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 866 .mismatch = TEXT_TO_ANY_INIT, 867}, 868{ 869 .fromsec = { DATA_SECTIONS, NULL }, 870 .bad_tosec = { ALL_XXXINIT_SECTIONS, INIT_SECTIONS, NULL }, 871 .mismatch = DATA_TO_ANY_INIT, 872}, 873{ 874 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 875 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 876 .mismatch = TEXTDATA_TO_ANY_EXIT, 877}, 878/* Do not reference init code/data from meminit code/data */ 879{ 880 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 881 .bad_tosec = { INIT_SECTIONS, NULL }, 882 .mismatch = XXXINIT_TO_SOME_INIT, 883}, 884/* Do not use exit code/data from init code */ 885{ 886 .fromsec = { ALL_INIT_SECTIONS, NULL }, 887 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 888 .mismatch = ANY_INIT_TO_ANY_EXIT, 889}, 890/* Do not use init code/data from exit code */ 891{ 892 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 893 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 894 .mismatch = ANY_EXIT_TO_ANY_INIT, 895}, 896{ 897 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 898 .bad_tosec = { INIT_SECTIONS, NULL }, 899 .mismatch = ANY_INIT_TO_ANY_EXIT, 900}, 901{ 902 .fromsec = { "__ex_table", NULL }, 903 /* If you're adding any new black-listed sections in here, consider 904 * adding a special 'printer' for them in scripts/check_extable. 905 */ 906 .bad_tosec = { ".altinstr_replacement", NULL }, 907 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 908 .mismatch = EXTABLE_TO_NON_TEXT, 909} 910}; 911 912static const struct sectioncheck *section_mismatch( 913 const char *fromsec, const char *tosec) 914{ 915 int i; 916 917 /* 918 * The target section could be the SHT_NUL section when we're 919 * handling relocations to un-resolved symbols, trying to match it 920 * doesn't make much sense and causes build failures on parisc 921 * architectures. 922 */ 923 if (*tosec == '\0') 924 return NULL; 925 926 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 927 const struct sectioncheck *check = §ioncheck[i]; 928 929 if (match(fromsec, check->fromsec)) { 930 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 931 return check; 932 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 933 return check; 934 } 935 } 936 return NULL; 937} 938 939/** 940 * Whitelist to allow certain references to pass with no warning. 941 * 942 * Pattern 1: 943 * If a module parameter is declared __initdata and permissions=0 944 * then this is legal despite the warning generated. 945 * We cannot see value of permissions here, so just ignore 946 * this pattern. 947 * The pattern is identified by: 948 * tosec = .init.data 949 * fromsec = .data* 950 * atsym =__param* 951 * 952 * Pattern 1a: 953 * module_param_call() ops can refer to __init set function if permissions=0 954 * The pattern is identified by: 955 * tosec = .init.text 956 * fromsec = .data* 957 * atsym = __param_ops_* 958 * 959 * Pattern 3: 960 * Whitelist all references from .head.text to any init section 961 * 962 * Pattern 4: 963 * Some symbols belong to init section but still it is ok to reference 964 * these from non-init sections as these symbols don't have any memory 965 * allocated for them and symbol address and value are same. So even 966 * if init section is freed, its ok to reference those symbols. 967 * For ex. symbols marking the init section boundaries. 968 * This pattern is identified by 969 * refsymname = __init_begin, _sinittext, _einittext 970 * 971 * Pattern 5: 972 * GCC may optimize static inlines when fed constant arg(s) resulting 973 * in functions like cpumask_empty() -- generating an associated symbol 974 * cpumask_empty.constprop.3 that appears in the audit. If the const that 975 * is passed in comes from __init, like say nmi_ipi_mask, we get a 976 * meaningless section warning. May need to add isra symbols too... 977 * This pattern is identified by 978 * tosec = init section 979 * fromsec = text section 980 * refsymname = *.constprop.* 981 * 982 **/ 983static int secref_whitelist(const char *fromsec, const char *fromsym, 984 const char *tosec, const char *tosym) 985{ 986 /* Check for pattern 1 */ 987 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 988 match(fromsec, PATTERNS(DATA_SECTIONS)) && 989 strstarts(fromsym, "__param")) 990 return 0; 991 992 /* Check for pattern 1a */ 993 if (strcmp(tosec, ".init.text") == 0 && 994 match(fromsec, PATTERNS(DATA_SECTIONS)) && 995 strstarts(fromsym, "__param_ops_")) 996 return 0; 997 998 /* symbols in data sections that may refer to any init/exit sections */ 999 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 1000 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 1001 match(fromsym, PATTERNS("*_template", // scsi uses *_template a lot 1002 "*_timer", // arm uses ops structures named _timer a lot 1003 "*_sht", // scsi also used *_sht to some extent 1004 "*_ops", 1005 "*_probe", 1006 "*_probe_one", 1007 "*_console"))) 1008 return 0; 1009 1010 /* symbols in data sections that may refer to meminit sections */ 1011 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 1012 match(tosec, PATTERNS(ALL_XXXINIT_SECTIONS)) && 1013 match(fromsym, PATTERNS("*driver"))) 1014 return 0; 1015 1016 /* 1017 * symbols in data sections must not refer to .exit.*, but there are 1018 * quite a few offenders, so hide these unless for W=1 builds until 1019 * these are fixed. 1020 */ 1021 if (!extra_warn && 1022 match(fromsec, PATTERNS(DATA_SECTIONS)) && 1023 match(tosec, PATTERNS(EXIT_SECTIONS)) && 1024 match(fromsym, PATTERNS("*driver"))) 1025 return 0; 1026 1027 /* Check for pattern 3 */ 1028 if (strstarts(fromsec, ".head.text") && 1029 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 1030 return 0; 1031 1032 /* Check for pattern 4 */ 1033 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 1034 return 0; 1035 1036 /* Check for pattern 5 */ 1037 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 1038 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 1039 match(fromsym, PATTERNS("*.constprop.*"))) 1040 return 0; 1041 1042 return 1; 1043} 1044 1045/* 1046 * If there's no name there, ignore it; likewise, ignore it if it's 1047 * one of the magic symbols emitted used by current tools. 1048 * 1049 * Otherwise if find_symbols_between() returns those symbols, they'll 1050 * fail the whitelist tests and cause lots of false alarms ... fixable 1051 * only by merging __exit and __init sections into __text, bloating 1052 * the kernel (which is especially evil on embedded platforms). 1053 */ 1054static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 1055{ 1056 const char *name = elf->strtab + sym->st_name; 1057 1058 if (!name || !strlen(name)) 1059 return 0; 1060 return !is_mapping_symbol(name); 1061} 1062 1063/* Look up the nearest symbol based on the section and the address */ 1064static Elf_Sym *find_nearest_sym(struct elf_info *elf, Elf_Addr addr, 1065 unsigned int secndx, bool allow_negative, 1066 Elf_Addr min_distance) 1067{ 1068 Elf_Sym *sym; 1069 Elf_Sym *near = NULL; 1070 Elf_Addr sym_addr, distance; 1071 bool is_arm = (elf->hdr->e_machine == EM_ARM); 1072 1073 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1074 if (get_secindex(elf, sym) != secndx) 1075 continue; 1076 if (!is_valid_name(elf, sym)) 1077 continue; 1078 1079 sym_addr = sym->st_value; 1080 1081 /* 1082 * For ARM Thumb instruction, the bit 0 of st_value is set 1083 * if the symbol is STT_FUNC type. Mask it to get the address. 1084 */ 1085 if (is_arm && ELF_ST_TYPE(sym->st_info) == STT_FUNC) 1086 sym_addr &= ~1; 1087 1088 if (addr >= sym_addr) 1089 distance = addr - sym_addr; 1090 else if (allow_negative) 1091 distance = sym_addr - addr; 1092 else 1093 continue; 1094 1095 if (distance <= min_distance) { 1096 min_distance = distance; 1097 near = sym; 1098 } 1099 1100 if (min_distance == 0) 1101 break; 1102 } 1103 return near; 1104} 1105 1106static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 1107 unsigned int secndx) 1108{ 1109 return find_nearest_sym(elf, addr, secndx, false, ~0); 1110} 1111 1112static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 1113{ 1114 /* If the supplied symbol has a valid name, return it */ 1115 if (is_valid_name(elf, sym)) 1116 return sym; 1117 1118 /* 1119 * Strive to find a better symbol name, but the resulting name may not 1120 * match the symbol referenced in the original code. 1121 */ 1122 return find_nearest_sym(elf, addr, get_secindex(elf, sym), true, 20); 1123} 1124 1125static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 1126{ 1127 if (secndx >= elf->num_sections) 1128 return false; 1129 1130 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 1131} 1132 1133static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1134 const struct sectioncheck* const mismatch, 1135 Elf_Sym *tsym, 1136 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1137 const char *tosec, Elf_Addr taddr) 1138{ 1139 Elf_Sym *from; 1140 const char *tosym; 1141 const char *fromsym; 1142 1143 from = find_fromsym(elf, faddr, fsecndx); 1144 fromsym = sym_name(elf, from); 1145 1146 tsym = find_tosym(elf, taddr, tsym); 1147 tosym = sym_name(elf, tsym); 1148 1149 /* check whitelist - we may ignore it */ 1150 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1151 return; 1152 1153 sec_mismatch_count++; 1154 1155 warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n", 1156 modname, fromsym, (unsigned int)(faddr - from->st_value), fromsec, tosym, tosec); 1157 1158 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1159 if (match(tosec, mismatch->bad_tosec)) 1160 fatal("The relocation at %s+0x%lx references\n" 1161 "section \"%s\" which is black-listed.\n" 1162 "Something is seriously wrong and should be fixed.\n" 1163 "You might get more information about where this is\n" 1164 "coming from by using scripts/check_extable.sh %s\n", 1165 fromsec, (long)faddr, tosec, modname); 1166 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1167 warn("The relocation at %s+0x%lx references\n" 1168 "section \"%s\" which is not in the list of\n" 1169 "authorized sections. If you're adding a new section\n" 1170 "and/or if this reference is valid, add \"%s\" to the\n" 1171 "list of authorized sections to jump to on fault.\n" 1172 "This can be achieved by adding \"%s\" to\n" 1173 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1174 fromsec, (long)faddr, tosec, tosec, tosec); 1175 else 1176 error("%s+0x%lx references non-executable section '%s'\n", 1177 fromsec, (long)faddr, tosec); 1178 } 1179} 1180 1181static void check_export_symbol(struct module *mod, struct elf_info *elf, 1182 Elf_Addr faddr, const char *secname, 1183 Elf_Sym *sym) 1184{ 1185 static const char *prefix = "__export_symbol_"; 1186 const char *label_name, *name, *data; 1187 Elf_Sym *label; 1188 struct symbol *s; 1189 bool is_gpl; 1190 1191 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1192 label_name = sym_name(elf, label); 1193 1194 if (!strstarts(label_name, prefix)) { 1195 error("%s: .export_symbol section contains strange symbol '%s'\n", 1196 mod->name, label_name); 1197 return; 1198 } 1199 1200 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1201 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1202 error("%s: local symbol '%s' was exported\n", mod->name, 1203 label_name + strlen(prefix)); 1204 return; 1205 } 1206 1207 name = sym_name(elf, sym); 1208 if (strcmp(label_name + strlen(prefix), name)) { 1209 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1210 mod->name, name); 1211 return; 1212 } 1213 1214 data = sym_get_data(elf, label); /* license */ 1215 if (!strcmp(data, "GPL")) { 1216 is_gpl = true; 1217 } else if (!strcmp(data, "")) { 1218 is_gpl = false; 1219 } else { 1220 error("%s: unknown license '%s' was specified for '%s'\n", 1221 mod->name, data, name); 1222 return; 1223 } 1224 1225 data += strlen(data) + 1; /* namespace */ 1226 s = sym_add_exported(name, mod, is_gpl, data); 1227 1228 /* 1229 * We need to be aware whether we are exporting a function or 1230 * a data on some architectures. 1231 */ 1232 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1233 1234 /* 1235 * For parisc64, symbols prefixed $$ from the library have the symbol type 1236 * STT_LOPROC. They should be handled as functions too. 1237 */ 1238 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1239 elf->hdr->e_machine == EM_PARISC && 1240 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1241 s->is_func = true; 1242 1243 if (match(secname, PATTERNS(INIT_SECTIONS))) 1244 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1245 mod->name, name); 1246 else if (match(secname, PATTERNS(EXIT_SECTIONS))) 1247 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1248 mod->name, name); 1249} 1250 1251static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1252 Elf_Sym *sym, 1253 unsigned int fsecndx, const char *fromsec, 1254 Elf_Addr faddr, Elf_Addr taddr) 1255{ 1256 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1257 const struct sectioncheck *mismatch; 1258 1259 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1260 check_export_symbol(mod, elf, faddr, tosec, sym); 1261 return; 1262 } 1263 1264 mismatch = section_mismatch(fromsec, tosec); 1265 if (!mismatch) 1266 return; 1267 1268 default_mismatch_handler(mod->name, elf, mismatch, sym, 1269 fsecndx, fromsec, faddr, 1270 tosec, taddr); 1271} 1272 1273static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1274{ 1275 switch (r_type) { 1276 case R_386_32: 1277 return TO_NATIVE(*location); 1278 case R_386_PC32: 1279 return TO_NATIVE(*location) + 4; 1280 } 1281 1282 return (Elf_Addr)(-1); 1283} 1284 1285#ifndef R_ARM_CALL 1286#define R_ARM_CALL 28 1287#endif 1288#ifndef R_ARM_JUMP24 1289#define R_ARM_JUMP24 29 1290#endif 1291 1292#ifndef R_ARM_THM_CALL 1293#define R_ARM_THM_CALL 10 1294#endif 1295#ifndef R_ARM_THM_JUMP24 1296#define R_ARM_THM_JUMP24 30 1297#endif 1298 1299#ifndef R_ARM_MOVW_ABS_NC 1300#define R_ARM_MOVW_ABS_NC 43 1301#endif 1302 1303#ifndef R_ARM_MOVT_ABS 1304#define R_ARM_MOVT_ABS 44 1305#endif 1306 1307#ifndef R_ARM_THM_MOVW_ABS_NC 1308#define R_ARM_THM_MOVW_ABS_NC 47 1309#endif 1310 1311#ifndef R_ARM_THM_MOVT_ABS 1312#define R_ARM_THM_MOVT_ABS 48 1313#endif 1314 1315#ifndef R_ARM_THM_JUMP19 1316#define R_ARM_THM_JUMP19 51 1317#endif 1318 1319static int32_t sign_extend32(int32_t value, int index) 1320{ 1321 uint8_t shift = 31 - index; 1322 1323 return (int32_t)(value << shift) >> shift; 1324} 1325 1326static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1327{ 1328 uint32_t inst, upper, lower, sign, j1, j2; 1329 int32_t offset; 1330 1331 switch (r_type) { 1332 case R_ARM_ABS32: 1333 case R_ARM_REL32: 1334 inst = TO_NATIVE(*(uint32_t *)loc); 1335 return inst + sym->st_value; 1336 case R_ARM_MOVW_ABS_NC: 1337 case R_ARM_MOVT_ABS: 1338 inst = TO_NATIVE(*(uint32_t *)loc); 1339 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1340 15); 1341 return offset + sym->st_value; 1342 case R_ARM_PC24: 1343 case R_ARM_CALL: 1344 case R_ARM_JUMP24: 1345 inst = TO_NATIVE(*(uint32_t *)loc); 1346 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1347 return offset + sym->st_value + 8; 1348 case R_ARM_THM_MOVW_ABS_NC: 1349 case R_ARM_THM_MOVT_ABS: 1350 upper = TO_NATIVE(*(uint16_t *)loc); 1351 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1352 offset = sign_extend32(((upper & 0x000f) << 12) | 1353 ((upper & 0x0400) << 1) | 1354 ((lower & 0x7000) >> 4) | 1355 (lower & 0x00ff), 1356 15); 1357 return offset + sym->st_value; 1358 case R_ARM_THM_JUMP19: 1359 /* 1360 * Encoding T3: 1361 * S = upper[10] 1362 * imm6 = upper[5:0] 1363 * J1 = lower[13] 1364 * J2 = lower[11] 1365 * imm11 = lower[10:0] 1366 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1367 */ 1368 upper = TO_NATIVE(*(uint16_t *)loc); 1369 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1370 1371 sign = (upper >> 10) & 1; 1372 j1 = (lower >> 13) & 1; 1373 j2 = (lower >> 11) & 1; 1374 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1375 ((upper & 0x03f) << 12) | 1376 ((lower & 0x07ff) << 1), 1377 20); 1378 return offset + sym->st_value + 4; 1379 case R_ARM_THM_CALL: 1380 case R_ARM_THM_JUMP24: 1381 /* 1382 * Encoding T4: 1383 * S = upper[10] 1384 * imm10 = upper[9:0] 1385 * J1 = lower[13] 1386 * J2 = lower[11] 1387 * imm11 = lower[10:0] 1388 * I1 = NOT(J1 XOR S) 1389 * I2 = NOT(J2 XOR S) 1390 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1391 */ 1392 upper = TO_NATIVE(*(uint16_t *)loc); 1393 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1394 1395 sign = (upper >> 10) & 1; 1396 j1 = (lower >> 13) & 1; 1397 j2 = (lower >> 11) & 1; 1398 offset = sign_extend32((sign << 24) | 1399 ((~(j1 ^ sign) & 1) << 23) | 1400 ((~(j2 ^ sign) & 1) << 22) | 1401 ((upper & 0x03ff) << 12) | 1402 ((lower & 0x07ff) << 1), 1403 24); 1404 return offset + sym->st_value + 4; 1405 } 1406 1407 return (Elf_Addr)(-1); 1408} 1409 1410static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1411{ 1412 uint32_t inst; 1413 1414 inst = TO_NATIVE(*location); 1415 switch (r_type) { 1416 case R_MIPS_LO16: 1417 return inst & 0xffff; 1418 case R_MIPS_26: 1419 return (inst & 0x03ffffff) << 2; 1420 case R_MIPS_32: 1421 return inst; 1422 } 1423 return (Elf_Addr)(-1); 1424} 1425 1426#ifndef EM_RISCV 1427#define EM_RISCV 243 1428#endif 1429 1430#ifndef R_RISCV_SUB32 1431#define R_RISCV_SUB32 39 1432#endif 1433 1434#ifndef EM_LOONGARCH 1435#define EM_LOONGARCH 258 1436#endif 1437 1438#ifndef R_LARCH_SUB32 1439#define R_LARCH_SUB32 55 1440#endif 1441 1442static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1443 unsigned int *r_type, unsigned int *r_sym) 1444{ 1445 typedef struct { 1446 Elf64_Word r_sym; /* Symbol index */ 1447 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1448 unsigned char r_type3; /* 3rd relocation type */ 1449 unsigned char r_type2; /* 2nd relocation type */ 1450 unsigned char r_type; /* 1st relocation type */ 1451 } Elf64_Mips_R_Info; 1452 1453 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1454 1455 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1456 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1457 1458 *r_type = mips64_r_info->r_type; 1459 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1460 return; 1461 } 1462 1463 if (is_64bit) { 1464 Elf64_Xword r_info64 = r_info; 1465 1466 r_info = TO_NATIVE(r_info64); 1467 } else { 1468 Elf32_Word r_info32 = r_info; 1469 1470 r_info = TO_NATIVE(r_info32); 1471 } 1472 1473 *r_type = ELF_R_TYPE(r_info); 1474 *r_sym = ELF_R_SYM(r_info); 1475} 1476 1477static void section_rela(struct module *mod, struct elf_info *elf, 1478 Elf_Shdr *sechdr) 1479{ 1480 Elf_Rela *rela; 1481 unsigned int fsecndx = sechdr->sh_info; 1482 const char *fromsec = sec_name(elf, fsecndx); 1483 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; 1484 Elf_Rela *stop = (void *)start + sechdr->sh_size; 1485 1486 /* if from section (name) is know good then skip it */ 1487 if (match(fromsec, section_white_list)) 1488 return; 1489 1490 for (rela = start; rela < stop; rela++) { 1491 Elf_Sym *tsym; 1492 Elf_Addr taddr, r_offset; 1493 unsigned int r_type, r_sym; 1494 1495 r_offset = TO_NATIVE(rela->r_offset); 1496 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1497 1498 tsym = elf->symtab_start + r_sym; 1499 taddr = tsym->st_value + TO_NATIVE(rela->r_addend); 1500 1501 switch (elf->hdr->e_machine) { 1502 case EM_RISCV: 1503 if (!strcmp("__ex_table", fromsec) && 1504 r_type == R_RISCV_SUB32) 1505 continue; 1506 break; 1507 case EM_LOONGARCH: 1508 if (!strcmp("__ex_table", fromsec) && 1509 r_type == R_LARCH_SUB32) 1510 continue; 1511 break; 1512 } 1513 1514 check_section_mismatch(mod, elf, tsym, 1515 fsecndx, fromsec, r_offset, taddr); 1516 } 1517} 1518 1519static void section_rel(struct module *mod, struct elf_info *elf, 1520 Elf_Shdr *sechdr) 1521{ 1522 Elf_Rel *rel; 1523 unsigned int fsecndx = sechdr->sh_info; 1524 const char *fromsec = sec_name(elf, fsecndx); 1525 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset; 1526 Elf_Rel *stop = (void *)start + sechdr->sh_size; 1527 1528 /* if from section (name) is know good then skip it */ 1529 if (match(fromsec, section_white_list)) 1530 return; 1531 1532 for (rel = start; rel < stop; rel++) { 1533 Elf_Sym *tsym; 1534 Elf_Addr taddr = 0, r_offset; 1535 unsigned int r_type, r_sym; 1536 void *loc; 1537 1538 r_offset = TO_NATIVE(rel->r_offset); 1539 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1540 1541 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1542 tsym = elf->symtab_start + r_sym; 1543 1544 switch (elf->hdr->e_machine) { 1545 case EM_386: 1546 taddr = addend_386_rel(loc, r_type); 1547 break; 1548 case EM_ARM: 1549 taddr = addend_arm_rel(loc, tsym, r_type); 1550 break; 1551 case EM_MIPS: 1552 taddr = addend_mips_rel(loc, r_type); 1553 break; 1554 default: 1555 fatal("Please add code to calculate addend for this architecture\n"); 1556 } 1557 1558 check_section_mismatch(mod, elf, tsym, 1559 fsecndx, fromsec, r_offset, taddr); 1560 } 1561} 1562 1563/** 1564 * A module includes a number of sections that are discarded 1565 * either when loaded or when used as built-in. 1566 * For loaded modules all functions marked __init and all data 1567 * marked __initdata will be discarded when the module has been initialized. 1568 * Likewise for modules used built-in the sections marked __exit 1569 * are discarded because __exit marked function are supposed to be called 1570 * only when a module is unloaded which never happens for built-in modules. 1571 * The check_sec_ref() function traverses all relocation records 1572 * to find all references to a section that reference a section that will 1573 * be discarded and warns about it. 1574 **/ 1575static void check_sec_ref(struct module *mod, struct elf_info *elf) 1576{ 1577 int i; 1578 Elf_Shdr *sechdrs = elf->sechdrs; 1579 1580 /* Walk through all sections */ 1581 for (i = 0; i < elf->num_sections; i++) { 1582 check_section(mod->name, elf, &elf->sechdrs[i]); 1583 /* We want to process only relocation sections and not .init */ 1584 if (sechdrs[i].sh_type == SHT_RELA) 1585 section_rela(mod, elf, &elf->sechdrs[i]); 1586 else if (sechdrs[i].sh_type == SHT_REL) 1587 section_rel(mod, elf, &elf->sechdrs[i]); 1588 } 1589} 1590 1591static char *remove_dot(char *s) 1592{ 1593 size_t n = strcspn(s, "."); 1594 1595 if (n && s[n]) { 1596 size_t m = strspn(s + n + 1, "0123456789"); 1597 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1598 s[n] = 0; 1599 } 1600 return s; 1601} 1602 1603/* 1604 * The CRCs are recorded in .*.cmd files in the form of: 1605 * #SYMVER <name> <crc> 1606 */ 1607static void extract_crcs_for_object(const char *object, struct module *mod) 1608{ 1609 char cmd_file[PATH_MAX]; 1610 char *buf, *p; 1611 const char *base; 1612 int dirlen, ret; 1613 1614 base = strrchr(object, '/'); 1615 if (base) { 1616 base++; 1617 dirlen = base - object; 1618 } else { 1619 dirlen = 0; 1620 base = object; 1621 } 1622 1623 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1624 dirlen, object, base); 1625 if (ret >= sizeof(cmd_file)) { 1626 error("%s: too long path was truncated\n", cmd_file); 1627 return; 1628 } 1629 1630 buf = read_text_file(cmd_file); 1631 p = buf; 1632 1633 while ((p = strstr(p, "\n#SYMVER "))) { 1634 char *name; 1635 size_t namelen; 1636 unsigned int crc; 1637 struct symbol *sym; 1638 1639 name = p + strlen("\n#SYMVER "); 1640 1641 p = strchr(name, ' '); 1642 if (!p) 1643 break; 1644 1645 namelen = p - name; 1646 p++; 1647 1648 if (!isdigit(*p)) 1649 continue; /* skip this line */ 1650 1651 crc = strtoul(p, &p, 0); 1652 if (*p != '\n') 1653 continue; /* skip this line */ 1654 1655 name[namelen] = '\0'; 1656 1657 /* 1658 * sym_find_with_module() may return NULL here. 1659 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1660 * Since commit e1327a127703, genksyms calculates CRCs of all 1661 * symbols, including trimmed ones. Ignore orphan CRCs. 1662 */ 1663 sym = sym_find_with_module(name, mod); 1664 if (sym) 1665 sym_set_crc(sym, crc); 1666 } 1667 1668 free(buf); 1669} 1670 1671/* 1672 * The symbol versions (CRC) are recorded in the .*.cmd files. 1673 * Parse them to retrieve CRCs for the current module. 1674 */ 1675static void mod_set_crcs(struct module *mod) 1676{ 1677 char objlist[PATH_MAX]; 1678 char *buf, *p, *obj; 1679 int ret; 1680 1681 if (mod->is_vmlinux) { 1682 strcpy(objlist, ".vmlinux.objs"); 1683 } else { 1684 /* objects for a module are listed in the *.mod file. */ 1685 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1686 if (ret >= sizeof(objlist)) { 1687 error("%s: too long path was truncated\n", objlist); 1688 return; 1689 } 1690 } 1691 1692 buf = read_text_file(objlist); 1693 p = buf; 1694 1695 while ((obj = strsep(&p, "\n")) && obj[0]) 1696 extract_crcs_for_object(obj, mod); 1697 1698 free(buf); 1699} 1700 1701static void read_symbols(const char *modname) 1702{ 1703 const char *symname; 1704 char *version; 1705 char *license; 1706 char *namespace; 1707 struct module *mod; 1708 struct elf_info info = { }; 1709 Elf_Sym *sym; 1710 1711 if (!parse_elf(&info, modname)) 1712 return; 1713 1714 if (!strends(modname, ".o")) { 1715 error("%s: filename must be suffixed with .o\n", modname); 1716 return; 1717 } 1718 1719 /* strip trailing .o */ 1720 mod = new_module(modname, strlen(modname) - strlen(".o")); 1721 1722 if (!mod->is_vmlinux) { 1723 license = get_modinfo(&info, "license"); 1724 if (!license) 1725 error("missing MODULE_LICENSE() in %s\n", modname); 1726 while (license) { 1727 if (!license_is_gpl_compatible(license)) { 1728 mod->is_gpl_compatible = false; 1729 break; 1730 } 1731 license = get_next_modinfo(&info, "license", license); 1732 } 1733 1734 namespace = get_modinfo(&info, "import_ns"); 1735 while (namespace) { 1736 add_namespace(&mod->imported_namespaces, namespace); 1737 namespace = get_next_modinfo(&info, "import_ns", 1738 namespace); 1739 } 1740 } 1741 1742 if (extra_warn && !get_modinfo(&info, "description")) 1743 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1744 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1745 symname = remove_dot(info.strtab + sym->st_name); 1746 1747 handle_symbol(mod, &info, sym, symname); 1748 handle_moddevtable(mod, &info, sym, symname); 1749 } 1750 1751 check_sec_ref(mod, &info); 1752 1753 if (!mod->is_vmlinux) { 1754 version = get_modinfo(&info, "version"); 1755 if (version || all_versions) 1756 get_src_version(mod->name, mod->srcversion, 1757 sizeof(mod->srcversion) - 1); 1758 } 1759 1760 parse_elf_finish(&info); 1761 1762 if (modversions) { 1763 /* 1764 * Our trick to get versioning for module struct etc. - it's 1765 * never passed as an argument to an exported function, so 1766 * the automatic versioning doesn't pick it up, but it's really 1767 * important anyhow. 1768 */ 1769 sym_add_unresolved("module_layout", mod, false); 1770 1771 mod_set_crcs(mod); 1772 } 1773} 1774 1775static void read_symbols_from_files(const char *filename) 1776{ 1777 FILE *in = stdin; 1778 char fname[PATH_MAX]; 1779 1780 in = fopen(filename, "r"); 1781 if (!in) 1782 fatal("Can't open filenames file %s: %m", filename); 1783 1784 while (fgets(fname, PATH_MAX, in) != NULL) { 1785 if (strends(fname, "\n")) 1786 fname[strlen(fname)-1] = '\0'; 1787 read_symbols(fname); 1788 } 1789 1790 fclose(in); 1791} 1792 1793#define SZ 500 1794 1795/* We first write the generated file into memory using the 1796 * following helper, then compare to the file on disk and 1797 * only update the later if anything changed */ 1798 1799void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1800 const char *fmt, ...) 1801{ 1802 char tmp[SZ]; 1803 int len; 1804 va_list ap; 1805 1806 va_start(ap, fmt); 1807 len = vsnprintf(tmp, SZ, fmt, ap); 1808 buf_write(buf, tmp, len); 1809 va_end(ap); 1810} 1811 1812void buf_write(struct buffer *buf, const char *s, int len) 1813{ 1814 if (buf->size - buf->pos < len) { 1815 buf->size += len + SZ; 1816 buf->p = NOFAIL(realloc(buf->p, buf->size)); 1817 } 1818 strncpy(buf->p + buf->pos, s, len); 1819 buf->pos += len; 1820} 1821 1822static void check_exports(struct module *mod) 1823{ 1824 struct symbol *s, *exp; 1825 1826 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1827 const char *basename; 1828 exp = find_symbol(s->name); 1829 if (!exp) { 1830 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1831 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, 1832 "\"%s\" [%s.ko] undefined!\n", 1833 s->name, mod->name); 1834 continue; 1835 } 1836 if (exp->module == mod) { 1837 error("\"%s\" [%s.ko] was exported without definition\n", 1838 s->name, mod->name); 1839 continue; 1840 } 1841 1842 exp->used = true; 1843 s->module = exp->module; 1844 s->crc_valid = exp->crc_valid; 1845 s->crc = exp->crc; 1846 1847 basename = strrchr(mod->name, '/'); 1848 if (basename) 1849 basename++; 1850 else 1851 basename = mod->name; 1852 1853 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1854 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, 1855 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1856 basename, exp->name, exp->namespace); 1857 add_namespace(&mod->missing_namespaces, exp->namespace); 1858 } 1859 1860 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1861 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1862 basename, exp->name); 1863 } 1864} 1865 1866static void handle_white_list_exports(const char *white_list) 1867{ 1868 char *buf, *p, *name; 1869 1870 buf = read_text_file(white_list); 1871 p = buf; 1872 1873 while ((name = strsep(&p, "\n"))) { 1874 struct symbol *sym = find_symbol(name); 1875 1876 if (sym) 1877 sym->used = true; 1878 } 1879 1880 free(buf); 1881} 1882 1883static void check_modname_len(struct module *mod) 1884{ 1885 const char *mod_name; 1886 1887 mod_name = strrchr(mod->name, '/'); 1888 if (mod_name == NULL) 1889 mod_name = mod->name; 1890 else 1891 mod_name++; 1892 if (strlen(mod_name) >= MODULE_NAME_LEN) 1893 error("module name is too long [%s.ko]\n", mod->name); 1894} 1895 1896/** 1897 * Header for the generated file 1898 **/ 1899static void add_header(struct buffer *b, struct module *mod) 1900{ 1901 buf_printf(b, "#include <linux/module.h>\n"); 1902 /* 1903 * Include build-salt.h after module.h in order to 1904 * inherit the definitions. 1905 */ 1906 buf_printf(b, "#define INCLUDE_VERMAGIC\n"); 1907 buf_printf(b, "#include <linux/build-salt.h>\n"); 1908 buf_printf(b, "#include <linux/elfnote-lto.h>\n"); 1909 buf_printf(b, "#include <linux/export-internal.h>\n"); 1910 buf_printf(b, "#include <linux/vermagic.h>\n"); 1911 buf_printf(b, "#include <linux/compiler.h>\n"); 1912 buf_printf(b, "\n"); 1913 buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n"); 1914 buf_printf(b, "#include <asm/orc_header.h>\n"); 1915 buf_printf(b, "ORC_HEADER;\n"); 1916 buf_printf(b, "#endif\n"); 1917 buf_printf(b, "\n"); 1918 buf_printf(b, "BUILD_SALT;\n"); 1919 buf_printf(b, "BUILD_LTO_INFO;\n"); 1920 buf_printf(b, "\n"); 1921 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1922 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1923 buf_printf(b, "\n"); 1924 buf_printf(b, "__visible struct module __this_module\n"); 1925 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1926 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1927 if (mod->has_init) 1928 buf_printf(b, "\t.init = init_module,\n"); 1929 if (mod->has_cleanup) 1930 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1931 "\t.exit = cleanup_module,\n" 1932 "#endif\n"); 1933 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1934 buf_printf(b, "};\n"); 1935 1936 if (!external_module) 1937 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1938 1939 buf_printf(b, 1940 "\n" 1941 "#ifdef CONFIG_RETPOLINE\n" 1942 "MODULE_INFO(retpoline, \"Y\");\n" 1943 "#endif\n"); 1944 1945 if (strstarts(mod->name, "drivers/staging")) 1946 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1947 1948 if (strstarts(mod->name, "tools/testing")) 1949 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1950} 1951 1952static void add_exported_symbols(struct buffer *buf, struct module *mod) 1953{ 1954 struct symbol *sym; 1955 1956 /* generate struct for exported symbols */ 1957 buf_printf(buf, "\n"); 1958 list_for_each_entry(sym, &mod->exported_symbols, list) { 1959 if (trim_unused_exports && !sym->used) 1960 continue; 1961 1962 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1963 sym->is_func ? "FUNC" : "DATA", sym->name, 1964 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1965 } 1966 1967 if (!modversions) 1968 return; 1969 1970 /* record CRCs for exported symbols */ 1971 buf_printf(buf, "\n"); 1972 list_for_each_entry(sym, &mod->exported_symbols, list) { 1973 if (trim_unused_exports && !sym->used) 1974 continue; 1975 1976 if (!sym->crc_valid) 1977 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1978 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1979 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1980 sym->name); 1981 1982 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1983 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1984 } 1985} 1986 1987/** 1988 * Record CRCs for unresolved symbols 1989 **/ 1990static void add_versions(struct buffer *b, struct module *mod) 1991{ 1992 struct symbol *s; 1993 1994 if (!modversions) 1995 return; 1996 1997 buf_printf(b, "\n"); 1998 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1999 buf_printf(b, "__used __section(\"__versions\") = {\n"); 2000 2001 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2002 if (!s->module) 2003 continue; 2004 if (!s->crc_valid) { 2005 warn("\"%s\" [%s.ko] has no CRC!\n", 2006 s->name, mod->name); 2007 continue; 2008 } 2009 if (strlen(s->name) >= MODULE_NAME_LEN) { 2010 error("too long symbol \"%s\" [%s.ko]\n", 2011 s->name, mod->name); 2012 break; 2013 } 2014 buf_printf(b, "\t{ %#8x, \"%s\" },\n", 2015 s->crc, s->name); 2016 } 2017 2018 buf_printf(b, "};\n"); 2019} 2020 2021static void add_depends(struct buffer *b, struct module *mod) 2022{ 2023 struct symbol *s; 2024 int first = 1; 2025 2026 /* Clear ->seen flag of modules that own symbols needed by this. */ 2027 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2028 if (s->module) 2029 s->module->seen = s->module->is_vmlinux; 2030 } 2031 2032 buf_printf(b, "\n"); 2033 buf_printf(b, "MODULE_INFO(depends, \""); 2034 list_for_each_entry(s, &mod->unresolved_symbols, list) { 2035 const char *p; 2036 if (!s->module) 2037 continue; 2038 2039 if (s->module->seen) 2040 continue; 2041 2042 s->module->seen = true; 2043 p = strrchr(s->module->name, '/'); 2044 if (p) 2045 p++; 2046 else 2047 p = s->module->name; 2048 buf_printf(b, "%s%s", first ? "" : ",", p); 2049 first = 0; 2050 } 2051 buf_printf(b, "\");\n"); 2052} 2053 2054static void add_srcversion(struct buffer *b, struct module *mod) 2055{ 2056 if (mod->srcversion[0]) { 2057 buf_printf(b, "\n"); 2058 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 2059 mod->srcversion); 2060 } 2061} 2062 2063static void write_buf(struct buffer *b, const char *fname) 2064{ 2065 FILE *file; 2066 2067 if (error_occurred) 2068 return; 2069 2070 file = fopen(fname, "w"); 2071 if (!file) { 2072 perror(fname); 2073 exit(1); 2074 } 2075 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2076 perror(fname); 2077 exit(1); 2078 } 2079 if (fclose(file) != 0) { 2080 perror(fname); 2081 exit(1); 2082 } 2083} 2084 2085static void write_if_changed(struct buffer *b, const char *fname) 2086{ 2087 char *tmp; 2088 FILE *file; 2089 struct stat st; 2090 2091 file = fopen(fname, "r"); 2092 if (!file) 2093 goto write; 2094 2095 if (fstat(fileno(file), &st) < 0) 2096 goto close_write; 2097 2098 if (st.st_size != b->pos) 2099 goto close_write; 2100 2101 tmp = NOFAIL(malloc(b->pos)); 2102 if (fread(tmp, 1, b->pos, file) != b->pos) 2103 goto free_write; 2104 2105 if (memcmp(tmp, b->p, b->pos) != 0) 2106 goto free_write; 2107 2108 free(tmp); 2109 fclose(file); 2110 return; 2111 2112 free_write: 2113 free(tmp); 2114 close_write: 2115 fclose(file); 2116 write: 2117 write_buf(b, fname); 2118} 2119 2120static void write_vmlinux_export_c_file(struct module *mod) 2121{ 2122 struct buffer buf = { }; 2123 2124 buf_printf(&buf, 2125 "#include <linux/export-internal.h>\n"); 2126 2127 add_exported_symbols(&buf, mod); 2128 write_if_changed(&buf, ".vmlinux.export.c"); 2129 free(buf.p); 2130} 2131 2132/* do sanity checks, and generate *.mod.c file */ 2133static void write_mod_c_file(struct module *mod) 2134{ 2135 struct buffer buf = { }; 2136 char fname[PATH_MAX]; 2137 int ret; 2138 2139 add_header(&buf, mod); 2140 add_exported_symbols(&buf, mod); 2141 add_versions(&buf, mod); 2142 add_depends(&buf, mod); 2143 add_moddevtable(&buf, mod); 2144 add_srcversion(&buf, mod); 2145 2146 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 2147 if (ret >= sizeof(fname)) { 2148 error("%s: too long path was truncated\n", fname); 2149 goto free; 2150 } 2151 2152 write_if_changed(&buf, fname); 2153 2154free: 2155 free(buf.p); 2156} 2157 2158/* parse Module.symvers file. line format: 2159 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 2160 **/ 2161static void read_dump(const char *fname) 2162{ 2163 char *buf, *pos, *line; 2164 2165 buf = read_text_file(fname); 2166 if (!buf) 2167 /* No symbol versions, silently ignore */ 2168 return; 2169 2170 pos = buf; 2171 2172 while ((line = get_line(&pos))) { 2173 char *symname, *namespace, *modname, *d, *export; 2174 unsigned int crc; 2175 struct module *mod; 2176 struct symbol *s; 2177 bool gpl_only; 2178 2179 if (!(symname = strchr(line, '\t'))) 2180 goto fail; 2181 *symname++ = '\0'; 2182 if (!(modname = strchr(symname, '\t'))) 2183 goto fail; 2184 *modname++ = '\0'; 2185 if (!(export = strchr(modname, '\t'))) 2186 goto fail; 2187 *export++ = '\0'; 2188 if (!(namespace = strchr(export, '\t'))) 2189 goto fail; 2190 *namespace++ = '\0'; 2191 2192 crc = strtoul(line, &d, 16); 2193 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2194 goto fail; 2195 2196 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2197 gpl_only = true; 2198 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2199 gpl_only = false; 2200 } else { 2201 error("%s: unknown license %s. skip", symname, export); 2202 continue; 2203 } 2204 2205 mod = find_module(modname); 2206 if (!mod) { 2207 mod = new_module(modname, strlen(modname)); 2208 mod->from_dump = true; 2209 } 2210 s = sym_add_exported(symname, mod, gpl_only, namespace); 2211 sym_set_crc(s, crc); 2212 } 2213 free(buf); 2214 return; 2215fail: 2216 free(buf); 2217 fatal("parse error in symbol dump file\n"); 2218} 2219 2220static void write_dump(const char *fname) 2221{ 2222 struct buffer buf = { }; 2223 struct module *mod; 2224 struct symbol *sym; 2225 2226 list_for_each_entry(mod, &modules, list) { 2227 if (mod->from_dump) 2228 continue; 2229 list_for_each_entry(sym, &mod->exported_symbols, list) { 2230 if (trim_unused_exports && !sym->used) 2231 continue; 2232 2233 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2234 sym->crc, sym->name, mod->name, 2235 sym->is_gpl_only ? "_GPL" : "", 2236 sym->namespace); 2237 } 2238 } 2239 write_buf(&buf, fname); 2240 free(buf.p); 2241} 2242 2243static void write_namespace_deps_files(const char *fname) 2244{ 2245 struct module *mod; 2246 struct namespace_list *ns; 2247 struct buffer ns_deps_buf = {}; 2248 2249 list_for_each_entry(mod, &modules, list) { 2250 2251 if (mod->from_dump || list_empty(&mod->missing_namespaces)) 2252 continue; 2253 2254 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2255 2256 list_for_each_entry(ns, &mod->missing_namespaces, list) 2257 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2258 2259 buf_printf(&ns_deps_buf, "\n"); 2260 } 2261 2262 write_if_changed(&ns_deps_buf, fname); 2263 free(ns_deps_buf.p); 2264} 2265 2266struct dump_list { 2267 struct list_head list; 2268 const char *file; 2269}; 2270 2271int main(int argc, char **argv) 2272{ 2273 struct module *mod; 2274 char *missing_namespace_deps = NULL; 2275 char *unused_exports_white_list = NULL; 2276 char *dump_write = NULL, *files_source = NULL; 2277 int opt; 2278 LIST_HEAD(dump_lists); 2279 struct dump_list *dl, *dl2; 2280 2281 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) { 2282 switch (opt) { 2283 case 'e': 2284 external_module = true; 2285 break; 2286 case 'i': 2287 dl = NOFAIL(malloc(sizeof(*dl))); 2288 dl->file = optarg; 2289 list_add_tail(&dl->list, &dump_lists); 2290 break; 2291 case 'M': 2292 module_enabled = true; 2293 break; 2294 case 'm': 2295 modversions = true; 2296 break; 2297 case 'n': 2298 ignore_missing_files = true; 2299 break; 2300 case 'o': 2301 dump_write = optarg; 2302 break; 2303 case 'a': 2304 all_versions = true; 2305 break; 2306 case 'T': 2307 files_source = optarg; 2308 break; 2309 case 't': 2310 trim_unused_exports = true; 2311 break; 2312 case 'u': 2313 unused_exports_white_list = optarg; 2314 break; 2315 case 'W': 2316 extra_warn = true; 2317 break; 2318 case 'w': 2319 warn_unresolved = true; 2320 break; 2321 case 'E': 2322 sec_mismatch_warn_only = false; 2323 break; 2324 case 'N': 2325 allow_missing_ns_imports = true; 2326 break; 2327 case 'd': 2328 missing_namespace_deps = optarg; 2329 break; 2330 default: 2331 exit(1); 2332 } 2333 } 2334 2335 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2336 read_dump(dl->file); 2337 list_del(&dl->list); 2338 free(dl); 2339 } 2340 2341 while (optind < argc) 2342 read_symbols(argv[optind++]); 2343 2344 if (files_source) 2345 read_symbols_from_files(files_source); 2346 2347 list_for_each_entry(mod, &modules, list) { 2348 if (mod->from_dump || mod->is_vmlinux) 2349 continue; 2350 2351 check_modname_len(mod); 2352 check_exports(mod); 2353 } 2354 2355 if (unused_exports_white_list) 2356 handle_white_list_exports(unused_exports_white_list); 2357 2358 list_for_each_entry(mod, &modules, list) { 2359 if (mod->from_dump) 2360 continue; 2361 2362 if (mod->is_vmlinux) 2363 write_vmlinux_export_c_file(mod); 2364 else 2365 write_mod_c_file(mod); 2366 } 2367 2368 if (missing_namespace_deps) 2369 write_namespace_deps_files(missing_namespace_deps); 2370 2371 if (dump_write) 2372 write_dump(dump_write); 2373 if (sec_mismatch_count && !sec_mismatch_warn_only) 2374 error("Section mismatches detected.\n" 2375 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2376 2377 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2378 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2379 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2380 2381 return error_occurred ? 1 : 0; 2382} 2383