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 <hashtable.h> 25 #include <list.h> 26 #include <xalloc.h> 27 #include "modpost.h" 28 #include "../../include/linux/license.h" 29 30 static bool module_enabled; 31 /* Are we using CONFIG_MODVERSIONS? */ 32 static bool modversions; 33 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 34 static bool all_versions; 35 /* If we are modposting external module set to 1 */ 36 static bool external_module; 37 /* Only warn about unresolved symbols */ 38 static bool warn_unresolved; 39 40 static int sec_mismatch_count; 41 static bool sec_mismatch_warn_only = true; 42 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */ 43 static bool trim_unused_exports; 44 45 /* ignore missing files */ 46 static bool ignore_missing_files; 47 /* If set to 1, only warn (instead of error) about missing ns imports */ 48 static bool allow_missing_ns_imports; 49 50 static bool error_occurred; 51 52 static bool extra_warn; 53 54 bool target_is_big_endian; 55 bool host_is_big_endian; 56 57 /* 58 * Cut off the warnings when there are too many. This typically occurs when 59 * vmlinux is missing. ('make modules' without building vmlinux.) 60 */ 61 #define MAX_UNRESOLVED_REPORTS 10 62 static unsigned int nr_unresolved; 63 64 /* In kernel, this size is defined in linux/module.h; 65 * here we use Elf_Addr instead of long for covering cross-compile 66 */ 67 68 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) 69 modpost_log(bool is_error,const char * fmt,...)70 void modpost_log(bool is_error, const char *fmt, ...) 71 { 72 va_list arglist; 73 74 if (is_error) { 75 fprintf(stderr, "ERROR: "); 76 error_occurred = true; 77 } else { 78 fprintf(stderr, "WARNING: "); 79 } 80 81 fprintf(stderr, "modpost: "); 82 83 va_start(arglist, fmt); 84 vfprintf(stderr, fmt, arglist); 85 va_end(arglist); 86 } 87 strends(const char * str,const char * postfix)88 static inline bool strends(const char *str, const char *postfix) 89 { 90 if (strlen(str) < strlen(postfix)) 91 return false; 92 93 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; 94 } 95 read_text_file(const char * filename)96 char *read_text_file(const char *filename) 97 { 98 struct stat st; 99 size_t nbytes; 100 int fd; 101 char *buf; 102 103 fd = open(filename, O_RDONLY); 104 if (fd < 0) { 105 perror(filename); 106 exit(1); 107 } 108 109 if (fstat(fd, &st) < 0) { 110 perror(filename); 111 exit(1); 112 } 113 114 buf = xmalloc(st.st_size + 1); 115 116 nbytes = st.st_size; 117 118 while (nbytes) { 119 ssize_t bytes_read; 120 121 bytes_read = read(fd, buf, nbytes); 122 if (bytes_read < 0) { 123 perror(filename); 124 exit(1); 125 } 126 127 nbytes -= bytes_read; 128 } 129 buf[st.st_size] = '\0'; 130 131 close(fd); 132 133 return buf; 134 } 135 get_line(char ** stringp)136 char *get_line(char **stringp) 137 { 138 char *orig = *stringp, *next; 139 140 /* do not return the unwanted extra line at EOF */ 141 if (!orig || *orig == '\0') 142 return NULL; 143 144 /* don't use strsep here, it is not available everywhere */ 145 next = strchr(orig, '\n'); 146 if (next) 147 *next++ = '\0'; 148 149 *stringp = next; 150 151 return orig; 152 } 153 154 /* A list of all modules we processed */ 155 LIST_HEAD(modules); 156 find_module(const char * modname)157 static struct module *find_module(const char *modname) 158 { 159 struct module *mod; 160 161 list_for_each_entry(mod, &modules, list) { 162 if (strcmp(mod->name, modname) == 0) 163 return mod; 164 } 165 return NULL; 166 } 167 new_module(const char * name,size_t namelen)168 static struct module *new_module(const char *name, size_t namelen) 169 { 170 struct module *mod; 171 172 mod = xmalloc(sizeof(*mod) + namelen + 1); 173 memset(mod, 0, sizeof(*mod)); 174 175 INIT_LIST_HEAD(&mod->exported_symbols); 176 INIT_LIST_HEAD(&mod->unresolved_symbols); 177 INIT_LIST_HEAD(&mod->missing_namespaces); 178 INIT_LIST_HEAD(&mod->imported_namespaces); 179 180 memcpy(mod->name, name, namelen); 181 mod->name[namelen] = '\0'; 182 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0); 183 184 /* 185 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE() 186 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue 187 * modpost will exit wiht error anyway. 188 */ 189 mod->is_gpl_compatible = true; 190 191 list_add_tail(&mod->list, &modules); 192 193 return mod; 194 } 195 196 struct symbol { 197 struct hlist_node hnode;/* link to hash table */ 198 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */ 199 struct module *module; 200 char *namespace; 201 unsigned int crc; 202 bool crc_valid; 203 bool weak; 204 bool is_func; 205 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ 206 bool used; /* there exists a user of this symbol */ 207 char name[]; 208 }; 209 210 static HASHTABLE_DEFINE(symbol_hashtable, 1U << 10); 211 212 /* This is based on the hash algorithm from gdbm, via tdb */ tdb_hash(const char * name)213 static inline unsigned int tdb_hash(const char *name) 214 { 215 unsigned value; /* Used to compute the hash value. */ 216 unsigned i; /* Used to cycle through random values. */ 217 218 /* Set the initial value from the key size. */ 219 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++) 220 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 221 222 return (1103515243 * value + 12345); 223 } 224 225 /** 226 * Allocate a new symbols for use in the hash of exported symbols or 227 * the list of unresolved symbols per module 228 **/ alloc_symbol(const char * name)229 static struct symbol *alloc_symbol(const char *name) 230 { 231 struct symbol *s = xmalloc(sizeof(*s) + strlen(name) + 1); 232 233 memset(s, 0, sizeof(*s)); 234 strcpy(s->name, name); 235 236 return s; 237 } 238 239 /* For the hash of exported symbols */ hash_add_symbol(struct symbol * sym)240 static void hash_add_symbol(struct symbol *sym) 241 { 242 hash_add(symbol_hashtable, &sym->hnode, tdb_hash(sym->name)); 243 } 244 sym_add_unresolved(const char * name,struct module * mod,bool weak)245 static void sym_add_unresolved(const char *name, struct module *mod, bool weak) 246 { 247 struct symbol *sym; 248 249 sym = alloc_symbol(name); 250 sym->weak = weak; 251 252 list_add_tail(&sym->list, &mod->unresolved_symbols); 253 } 254 sym_find_with_module(const char * name,struct module * mod)255 static struct symbol *sym_find_with_module(const char *name, struct module *mod) 256 { 257 struct symbol *s; 258 259 /* For our purposes, .foo matches foo. PPC64 needs this. */ 260 if (name[0] == '.') 261 name++; 262 263 hash_for_each_possible(symbol_hashtable, s, hnode, tdb_hash(name)) { 264 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) 265 return s; 266 } 267 return NULL; 268 } 269 find_symbol(const char * name)270 static struct symbol *find_symbol(const char *name) 271 { 272 return sym_find_with_module(name, NULL); 273 } 274 275 struct namespace_list { 276 struct list_head list; 277 char namespace[]; 278 }; 279 contains_namespace(struct list_head * head,const char * namespace)280 static bool contains_namespace(struct list_head *head, const char *namespace) 281 { 282 struct namespace_list *list; 283 284 /* 285 * The default namespace is null string "", which is always implicitly 286 * contained. 287 */ 288 if (!namespace[0]) 289 return true; 290 291 list_for_each_entry(list, head, list) { 292 if (!strcmp(list->namespace, namespace)) 293 return true; 294 } 295 296 return false; 297 } 298 add_namespace(struct list_head * head,const char * namespace)299 static void add_namespace(struct list_head *head, const char *namespace) 300 { 301 struct namespace_list *ns_entry; 302 303 if (!contains_namespace(head, namespace)) { 304 ns_entry = xmalloc(sizeof(*ns_entry) + strlen(namespace) + 1); 305 strcpy(ns_entry->namespace, namespace); 306 list_add_tail(&ns_entry->list, head); 307 } 308 } 309 sym_get_data_by_offset(const struct elf_info * info,unsigned int secindex,unsigned long offset)310 static void *sym_get_data_by_offset(const struct elf_info *info, 311 unsigned int secindex, unsigned long offset) 312 { 313 Elf_Shdr *sechdr = &info->sechdrs[secindex]; 314 315 return (void *)info->hdr + sechdr->sh_offset + offset; 316 } 317 sym_get_data(const struct elf_info * info,const Elf_Sym * sym)318 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) 319 { 320 return sym_get_data_by_offset(info, get_secindex(info, sym), 321 sym->st_value); 322 } 323 sech_name(const struct elf_info * info,Elf_Shdr * sechdr)324 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) 325 { 326 return sym_get_data_by_offset(info, info->secindex_strings, 327 sechdr->sh_name); 328 } 329 sec_name(const struct elf_info * info,unsigned int secindex)330 static const char *sec_name(const struct elf_info *info, unsigned int secindex) 331 { 332 /* 333 * If sym->st_shndx is a special section index, there is no 334 * corresponding section header. 335 * Return "" if the index is out of range of info->sechdrs[] array. 336 */ 337 if (secindex >= info->num_sections) 338 return ""; 339 340 return sech_name(info, &info->sechdrs[secindex]); 341 } 342 343 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) 344 sym_add_exported(const char * name,struct module * mod,bool gpl_only,const char * namespace)345 static struct symbol *sym_add_exported(const char *name, struct module *mod, 346 bool gpl_only, const char *namespace) 347 { 348 struct symbol *s = find_symbol(name); 349 350 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { 351 error("%s: '%s' exported twice. Previous export was in %s%s\n", 352 mod->name, name, s->module->name, 353 s->module->is_vmlinux ? "" : ".ko"); 354 } 355 356 s = alloc_symbol(name); 357 s->module = mod; 358 s->is_gpl_only = gpl_only; 359 s->namespace = xstrdup(namespace); 360 list_add_tail(&s->list, &mod->exported_symbols); 361 hash_add_symbol(s); 362 363 return s; 364 } 365 sym_set_crc(struct symbol * sym,unsigned int crc)366 static void sym_set_crc(struct symbol *sym, unsigned int crc) 367 { 368 sym->crc = crc; 369 sym->crc_valid = true; 370 } 371 grab_file(const char * filename,size_t * size)372 static void *grab_file(const char *filename, size_t *size) 373 { 374 struct stat st; 375 void *map = MAP_FAILED; 376 int fd; 377 378 fd = open(filename, O_RDONLY); 379 if (fd < 0) 380 return NULL; 381 if (fstat(fd, &st)) 382 goto failed; 383 384 *size = st.st_size; 385 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 386 387 failed: 388 close(fd); 389 if (map == MAP_FAILED) 390 return NULL; 391 return map; 392 } 393 release_file(void * file,size_t size)394 static void release_file(void *file, size_t size) 395 { 396 munmap(file, size); 397 } 398 parse_elf(struct elf_info * info,const char * filename)399 static int parse_elf(struct elf_info *info, const char *filename) 400 { 401 unsigned int i; 402 Elf_Ehdr *hdr; 403 Elf_Shdr *sechdrs; 404 Elf_Sym *sym; 405 const char *secstrings; 406 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 407 408 hdr = grab_file(filename, &info->size); 409 if (!hdr) { 410 if (ignore_missing_files) { 411 fprintf(stderr, "%s: %s (ignored)\n", filename, 412 strerror(errno)); 413 return 0; 414 } 415 perror(filename); 416 exit(1); 417 } 418 info->hdr = hdr; 419 if (info->size < sizeof(*hdr)) { 420 /* file too small, assume this is an empty .o file */ 421 return 0; 422 } 423 /* Is this a valid ELF file? */ 424 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 425 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 426 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 427 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 428 /* Not an ELF file - silently ignore it */ 429 return 0; 430 } 431 432 switch (hdr->e_ident[EI_DATA]) { 433 case ELFDATA2LSB: 434 target_is_big_endian = false; 435 break; 436 case ELFDATA2MSB: 437 target_is_big_endian = true; 438 break; 439 default: 440 fatal("target endian is unknown\n"); 441 } 442 443 /* Fix endianness in ELF header */ 444 hdr->e_type = TO_NATIVE(hdr->e_type); 445 hdr->e_machine = TO_NATIVE(hdr->e_machine); 446 hdr->e_version = TO_NATIVE(hdr->e_version); 447 hdr->e_entry = TO_NATIVE(hdr->e_entry); 448 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 449 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 450 hdr->e_flags = TO_NATIVE(hdr->e_flags); 451 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 452 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 453 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 454 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 455 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 456 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 457 sechdrs = (void *)hdr + hdr->e_shoff; 458 info->sechdrs = sechdrs; 459 460 /* modpost only works for relocatable objects */ 461 if (hdr->e_type != ET_REL) 462 fatal("%s: not relocatable object.", filename); 463 464 /* Check if file offset is correct */ 465 if (hdr->e_shoff > info->size) 466 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", 467 (unsigned long)hdr->e_shoff, filename, info->size); 468 469 if (hdr->e_shnum == SHN_UNDEF) { 470 /* 471 * There are more than 64k sections, 472 * read count from .sh_size. 473 */ 474 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 475 } 476 else { 477 info->num_sections = hdr->e_shnum; 478 } 479 if (hdr->e_shstrndx == SHN_XINDEX) { 480 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 481 } 482 else { 483 info->secindex_strings = hdr->e_shstrndx; 484 } 485 486 /* Fix endianness in section headers */ 487 for (i = 0; i < info->num_sections; i++) { 488 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 489 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 490 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 491 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 492 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 493 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 494 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 495 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 496 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 497 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 498 } 499 /* Find symbol table. */ 500 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 501 for (i = 1; i < info->num_sections; i++) { 502 const char *secname; 503 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 504 505 if (!nobits && sechdrs[i].sh_offset > info->size) 506 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n", 507 filename, (unsigned long)sechdrs[i].sh_offset, 508 sizeof(*hdr)); 509 510 secname = secstrings + sechdrs[i].sh_name; 511 if (strcmp(secname, ".modinfo") == 0) { 512 if (nobits) 513 fatal("%s has NOBITS .modinfo\n", filename); 514 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 515 info->modinfo_len = sechdrs[i].sh_size; 516 } else if (!strcmp(secname, ".export_symbol")) { 517 info->export_symbol_secndx = i; 518 } 519 520 if (sechdrs[i].sh_type == SHT_SYMTAB) { 521 unsigned int sh_link_idx; 522 symtab_idx = i; 523 info->symtab_start = (void *)hdr + 524 sechdrs[i].sh_offset; 525 info->symtab_stop = (void *)hdr + 526 sechdrs[i].sh_offset + sechdrs[i].sh_size; 527 sh_link_idx = sechdrs[i].sh_link; 528 info->strtab = (void *)hdr + 529 sechdrs[sh_link_idx].sh_offset; 530 } 531 532 /* 32bit section no. table? ("more than 64k sections") */ 533 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 534 symtab_shndx_idx = i; 535 info->symtab_shndx_start = (void *)hdr + 536 sechdrs[i].sh_offset; 537 info->symtab_shndx_stop = (void *)hdr + 538 sechdrs[i].sh_offset + sechdrs[i].sh_size; 539 } 540 } 541 if (!info->symtab_start) 542 fatal("%s has no symtab?\n", filename); 543 544 /* Fix endianness in symbols */ 545 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 546 sym->st_shndx = TO_NATIVE(sym->st_shndx); 547 sym->st_name = TO_NATIVE(sym->st_name); 548 sym->st_value = TO_NATIVE(sym->st_value); 549 sym->st_size = TO_NATIVE(sym->st_size); 550 } 551 552 if (symtab_shndx_idx != ~0U) { 553 Elf32_Word *p; 554 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 555 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 556 filename, sechdrs[symtab_shndx_idx].sh_link, 557 symtab_idx); 558 /* Fix endianness */ 559 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 560 p++) 561 *p = TO_NATIVE(*p); 562 } 563 564 symsearch_init(info); 565 566 return 1; 567 } 568 parse_elf_finish(struct elf_info * info)569 static void parse_elf_finish(struct elf_info *info) 570 { 571 symsearch_finish(info); 572 release_file(info->hdr, info->size); 573 } 574 ignore_undef_symbol(struct elf_info * info,const char * symname)575 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 576 { 577 /* ignore __this_module, it will be resolved shortly */ 578 if (strcmp(symname, "__this_module") == 0) 579 return 1; 580 /* ignore global offset table */ 581 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 582 return 1; 583 if (info->hdr->e_machine == EM_PPC) 584 /* Special register function linked on all modules during final link of .ko */ 585 if (strstarts(symname, "_restgpr_") || 586 strstarts(symname, "_savegpr_") || 587 strstarts(symname, "_rest32gpr_") || 588 strstarts(symname, "_save32gpr_") || 589 strstarts(symname, "_restvr_") || 590 strstarts(symname, "_savevr_")) 591 return 1; 592 if (info->hdr->e_machine == EM_PPC64) 593 /* Special register function linked on all modules during final link of .ko */ 594 if (strstarts(symname, "_restgpr0_") || 595 strstarts(symname, "_savegpr0_") || 596 strstarts(symname, "_restvr_") || 597 strstarts(symname, "_savevr_") || 598 strcmp(symname, ".TOC.") == 0) 599 return 1; 600 /* Do not ignore this symbol */ 601 return 0; 602 } 603 handle_symbol(struct module * mod,struct elf_info * info,const Elf_Sym * sym,const char * symname)604 static void handle_symbol(struct module *mod, struct elf_info *info, 605 const Elf_Sym *sym, const char *symname) 606 { 607 switch (sym->st_shndx) { 608 case SHN_COMMON: 609 if (strstarts(symname, "__gnu_lto_")) { 610 /* Should warn here, but modpost runs before the linker */ 611 } else 612 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 613 break; 614 case SHN_UNDEF: 615 /* undefined symbol */ 616 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 617 ELF_ST_BIND(sym->st_info) != STB_WEAK) 618 break; 619 if (ignore_undef_symbol(info, symname)) 620 break; 621 if (info->hdr->e_machine == EM_SPARC || 622 info->hdr->e_machine == EM_SPARCV9) { 623 /* Ignore register directives. */ 624 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 625 break; 626 if (symname[0] == '.') { 627 char *munged = xstrdup(symname); 628 munged[0] = '_'; 629 munged[1] = toupper(munged[1]); 630 symname = munged; 631 } 632 } 633 634 sym_add_unresolved(symname, mod, 635 ELF_ST_BIND(sym->st_info) == STB_WEAK); 636 break; 637 default: 638 if (strcmp(symname, "init_module") == 0) 639 mod->has_init = true; 640 if (strcmp(symname, "cleanup_module") == 0) 641 mod->has_cleanup = true; 642 break; 643 } 644 } 645 646 /** 647 * Parse tag=value strings from .modinfo section 648 **/ next_string(char * string,unsigned long * secsize)649 static char *next_string(char *string, unsigned long *secsize) 650 { 651 /* Skip non-zero chars */ 652 while (string[0]) { 653 string++; 654 if ((*secsize)-- <= 1) 655 return NULL; 656 } 657 658 /* Skip any zero padding. */ 659 while (!string[0]) { 660 string++; 661 if ((*secsize)-- <= 1) 662 return NULL; 663 } 664 return string; 665 } 666 get_next_modinfo(struct elf_info * info,const char * tag,char * prev)667 static char *get_next_modinfo(struct elf_info *info, const char *tag, 668 char *prev) 669 { 670 char *p; 671 unsigned int taglen = strlen(tag); 672 char *modinfo = info->modinfo; 673 unsigned long size = info->modinfo_len; 674 675 if (prev) { 676 size -= prev - modinfo; 677 modinfo = next_string(prev, &size); 678 } 679 680 for (p = modinfo; p; p = next_string(p, &size)) { 681 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 682 return p + taglen + 1; 683 } 684 return NULL; 685 } 686 get_modinfo(struct elf_info * info,const char * tag)687 static char *get_modinfo(struct elf_info *info, const char *tag) 688 689 { 690 return get_next_modinfo(info, tag, NULL); 691 } 692 sym_name(struct elf_info * elf,Elf_Sym * sym)693 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 694 { 695 return sym ? elf->strtab + sym->st_name : ""; 696 } 697 698 /* 699 * Check whether the 'string' argument matches one of the 'patterns', 700 * an array of shell wildcard patterns (glob). 701 * 702 * Return true is there is a match. 703 */ match(const char * string,const char * const patterns[])704 static bool match(const char *string, const char *const patterns[]) 705 { 706 const char *pattern; 707 708 while ((pattern = *patterns++)) { 709 if (!fnmatch(pattern, string, 0)) 710 return true; 711 } 712 713 return false; 714 } 715 716 /* useful to pass patterns to match() directly */ 717 #define PATTERNS(...) \ 718 ({ \ 719 static const char *const patterns[] = {__VA_ARGS__, NULL}; \ 720 patterns; \ 721 }) 722 723 /* sections that we do not want to do full section mismatch check on */ 724 static const char *const section_white_list[] = 725 { 726 ".comment*", 727 ".debug*", 728 ".zdebug*", /* Compressed debug sections. */ 729 ".GCC.command.line", /* record-gcc-switches */ 730 ".mdebug*", /* alpha, score, mips etc. */ 731 ".pdr", /* alpha, score, mips etc. */ 732 ".stab*", 733 ".note*", 734 ".got*", 735 ".toc*", 736 ".xt.prop", /* xtensa */ 737 ".xt.lit", /* xtensa */ 738 ".arcextmap*", /* arc */ 739 ".gnu.linkonce.arcext*", /* arc : modules */ 740 ".cmem*", /* EZchip */ 741 ".fmt_slot*", /* EZchip */ 742 ".gnu.lto*", 743 ".discard.*", 744 ".llvm.call-graph-profile", /* call graph */ 745 NULL 746 }; 747 748 /* 749 * This is used to find sections missing the SHF_ALLOC flag. 750 * The cause of this is often a section specified in assembler 751 * without "ax" / "aw". 752 */ check_section(const char * modname,struct elf_info * elf,Elf_Shdr * sechdr)753 static void check_section(const char *modname, struct elf_info *elf, 754 Elf_Shdr *sechdr) 755 { 756 const char *sec = sech_name(elf, sechdr); 757 758 if (sechdr->sh_type == SHT_PROGBITS && 759 !(sechdr->sh_flags & SHF_ALLOC) && 760 !match(sec, section_white_list)) { 761 warn("%s (%s): unexpected non-allocatable section.\n" 762 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 763 "Note that for example <linux/init.h> contains\n" 764 "section definitions for use in .S files.\n\n", 765 modname, sec); 766 } 767 } 768 769 770 771 #define ALL_INIT_DATA_SECTIONS \ 772 ".init.setup", ".init.rodata", ".init.data" 773 774 #define ALL_PCI_INIT_SECTIONS \ 775 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 776 ".pci_fixup_enable", ".pci_fixup_resume", \ 777 ".pci_fixup_resume_early", ".pci_fixup_suspend" 778 779 #define ALL_INIT_SECTIONS ".init.*" 780 #define ALL_EXIT_SECTIONS ".exit.*" 781 782 #define DATA_SECTIONS ".data", ".data.rel" 783 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ 784 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \ 785 ".ltext", ".ltext.*" 786 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ 787 ".fixup", ".entry.text", ".exception.text", \ 788 ".coldtext", ".softirqentry.text" 789 790 #define ALL_TEXT_SECTIONS ".init.text", ".exit.text", \ 791 TEXT_SECTIONS, OTHER_TEXT_SECTIONS 792 793 enum mismatch { 794 TEXTDATA_TO_ANY_INIT_EXIT, 795 XXXINIT_TO_SOME_INIT, 796 ANY_INIT_TO_ANY_EXIT, 797 ANY_EXIT_TO_ANY_INIT, 798 EXTABLE_TO_NON_TEXT, 799 }; 800 801 /** 802 * Describe how to match sections on different criteria: 803 * 804 * @fromsec: Array of sections to be matched. 805 * 806 * @bad_tosec: Relocations applied to a section in @fromsec to a section in 807 * this array is forbidden (black-list). Can be empty. 808 * 809 * @good_tosec: Relocations applied to a section in @fromsec must be 810 * targeting sections in this array (white-list). Can be empty. 811 * 812 * @mismatch: Type of mismatch. 813 */ 814 struct sectioncheck { 815 const char *fromsec[20]; 816 const char *bad_tosec[20]; 817 const char *good_tosec[20]; 818 enum mismatch mismatch; 819 }; 820 821 static const struct sectioncheck sectioncheck[] = { 822 /* Do not reference init/exit code/data from 823 * normal code and data 824 */ 825 { 826 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 827 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }, 828 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT, 829 }, 830 /* Do not use exit code/data from init code */ 831 { 832 .fromsec = { ALL_INIT_SECTIONS, NULL }, 833 .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, 834 .mismatch = ANY_INIT_TO_ANY_EXIT, 835 }, 836 /* Do not use init code/data from exit code */ 837 { 838 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 839 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 840 .mismatch = ANY_EXIT_TO_ANY_INIT, 841 }, 842 { 843 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 844 .bad_tosec = { ALL_INIT_SECTIONS, NULL }, 845 .mismatch = ANY_INIT_TO_ANY_EXIT, 846 }, 847 { 848 .fromsec = { "__ex_table", NULL }, 849 /* If you're adding any new black-listed sections in here, consider 850 * adding a special 'printer' for them in scripts/check_extable. 851 */ 852 .bad_tosec = { ".altinstr_replacement", NULL }, 853 .good_tosec = {ALL_TEXT_SECTIONS , NULL}, 854 .mismatch = EXTABLE_TO_NON_TEXT, 855 } 856 }; 857 section_mismatch(const char * fromsec,const char * tosec)858 static const struct sectioncheck *section_mismatch( 859 const char *fromsec, const char *tosec) 860 { 861 int i; 862 863 /* 864 * The target section could be the SHT_NUL section when we're 865 * handling relocations to un-resolved symbols, trying to match it 866 * doesn't make much sense and causes build failures on parisc 867 * architectures. 868 */ 869 if (*tosec == '\0') 870 return NULL; 871 872 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { 873 const struct sectioncheck *check = §ioncheck[i]; 874 875 if (match(fromsec, check->fromsec)) { 876 if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) 877 return check; 878 if (check->good_tosec[0] && !match(tosec, check->good_tosec)) 879 return check; 880 } 881 } 882 return NULL; 883 } 884 885 /** 886 * Whitelist to allow certain references to pass with no warning. 887 * 888 * Pattern 1: 889 * If a module parameter is declared __initdata and permissions=0 890 * then this is legal despite the warning generated. 891 * We cannot see value of permissions here, so just ignore 892 * this pattern. 893 * The pattern is identified by: 894 * tosec = .init.data 895 * fromsec = .data* 896 * atsym =__param* 897 * 898 * Pattern 1a: 899 * module_param_call() ops can refer to __init set function if permissions=0 900 * The pattern is identified by: 901 * tosec = .init.text 902 * fromsec = .data* 903 * atsym = __param_ops_* 904 * 905 * Pattern 3: 906 * Whitelist all references from .head.text to any init section 907 * 908 * Pattern 4: 909 * Some symbols belong to init section but still it is ok to reference 910 * these from non-init sections as these symbols don't have any memory 911 * allocated for them and symbol address and value are same. So even 912 * if init section is freed, its ok to reference those symbols. 913 * For ex. symbols marking the init section boundaries. 914 * This pattern is identified by 915 * refsymname = __init_begin, _sinittext, _einittext 916 * 917 * Pattern 5: 918 * GCC may optimize static inlines when fed constant arg(s) resulting 919 * in functions like cpumask_empty() -- generating an associated symbol 920 * cpumask_empty.constprop.3 that appears in the audit. If the const that 921 * is passed in comes from __init, like say nmi_ipi_mask, we get a 922 * meaningless section warning. May need to add isra symbols too... 923 * This pattern is identified by 924 * tosec = init section 925 * fromsec = text section 926 * refsymname = *.constprop.* 927 * 928 **/ secref_whitelist(const char * fromsec,const char * fromsym,const char * tosec,const char * tosym)929 static int secref_whitelist(const char *fromsec, const char *fromsym, 930 const char *tosec, const char *tosym) 931 { 932 /* Check for pattern 1 */ 933 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) && 934 match(fromsec, PATTERNS(DATA_SECTIONS)) && 935 strstarts(fromsym, "__param")) 936 return 0; 937 938 /* Check for pattern 1a */ 939 if (strcmp(tosec, ".init.text") == 0 && 940 match(fromsec, PATTERNS(DATA_SECTIONS)) && 941 strstarts(fromsym, "__param_ops_")) 942 return 0; 943 944 /* symbols in data sections that may refer to any init/exit sections */ 945 if (match(fromsec, PATTERNS(DATA_SECTIONS)) && 946 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && 947 match(fromsym, PATTERNS("*_ops", "*_probe", "*_console"))) 948 return 0; 949 950 /* Check for pattern 3 */ 951 if (strstarts(fromsec, ".head.text") && 952 match(tosec, PATTERNS(ALL_INIT_SECTIONS))) 953 return 0; 954 955 /* Check for pattern 4 */ 956 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext"))) 957 return 0; 958 959 /* Check for pattern 5 */ 960 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && 961 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && 962 match(fromsym, PATTERNS("*.constprop.*"))) 963 return 0; 964 965 return 1; 966 } 967 find_fromsym(struct elf_info * elf,Elf_Addr addr,unsigned int secndx)968 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr, 969 unsigned int secndx) 970 { 971 return symsearch_find_nearest(elf, addr, secndx, false, ~0); 972 } 973 find_tosym(struct elf_info * elf,Elf_Addr addr,Elf_Sym * sym)974 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym) 975 { 976 Elf_Sym *new_sym; 977 978 /* If the supplied symbol has a valid name, return it */ 979 if (is_valid_name(elf, sym)) 980 return sym; 981 982 /* 983 * Strive to find a better symbol name, but the resulting name may not 984 * match the symbol referenced in the original code. 985 */ 986 new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym), 987 true, 20); 988 return new_sym ? new_sym : sym; 989 } 990 is_executable_section(struct elf_info * elf,unsigned int secndx)991 static bool is_executable_section(struct elf_info *elf, unsigned int secndx) 992 { 993 if (secndx >= elf->num_sections) 994 return false; 995 996 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0; 997 } 998 default_mismatch_handler(const char * modname,struct elf_info * elf,const struct sectioncheck * const mismatch,Elf_Sym * tsym,unsigned int fsecndx,const char * fromsec,Elf_Addr faddr,const char * tosec,Elf_Addr taddr)999 static void default_mismatch_handler(const char *modname, struct elf_info *elf, 1000 const struct sectioncheck* const mismatch, 1001 Elf_Sym *tsym, 1002 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr, 1003 const char *tosec, Elf_Addr taddr) 1004 { 1005 Elf_Sym *from; 1006 const char *tosym; 1007 const char *fromsym; 1008 char taddr_str[16]; 1009 1010 from = find_fromsym(elf, faddr, fsecndx); 1011 fromsym = sym_name(elf, from); 1012 1013 tsym = find_tosym(elf, taddr, tsym); 1014 tosym = sym_name(elf, tsym); 1015 1016 /* check whitelist - we may ignore it */ 1017 if (!secref_whitelist(fromsec, fromsym, tosec, tosym)) 1018 return; 1019 1020 sec_mismatch_count++; 1021 1022 if (!tosym[0]) 1023 snprintf(taddr_str, sizeof(taddr_str), "0x%x", (unsigned int)taddr); 1024 1025 /* 1026 * The format for the reference source: <symbol_name>+<offset> or <address> 1027 * The format for the reference destination: <symbol_name> or <address> 1028 */ 1029 warn("%s: section mismatch in reference: %s%s0x%x (section: %s) -> %s (section: %s)\n", 1030 modname, fromsym, fromsym[0] ? "+" : "", 1031 (unsigned int)(faddr - (fromsym[0] ? from->st_value : 0)), 1032 fromsec, tosym[0] ? tosym : taddr_str, tosec); 1033 1034 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { 1035 if (match(tosec, mismatch->bad_tosec)) 1036 fatal("The relocation at %s+0x%lx references\n" 1037 "section \"%s\" which is black-listed.\n" 1038 "Something is seriously wrong and should be fixed.\n" 1039 "You might get more information about where this is\n" 1040 "coming from by using scripts/check_extable.sh %s\n", 1041 fromsec, (long)faddr, tosec, modname); 1042 else if (is_executable_section(elf, get_secindex(elf, tsym))) 1043 warn("The relocation at %s+0x%lx references\n" 1044 "section \"%s\" which is not in the list of\n" 1045 "authorized sections. If you're adding a new section\n" 1046 "and/or if this reference is valid, add \"%s\" to the\n" 1047 "list of authorized sections to jump to on fault.\n" 1048 "This can be achieved by adding \"%s\" to\n" 1049 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", 1050 fromsec, (long)faddr, tosec, tosec, tosec); 1051 else 1052 error("%s+0x%lx references non-executable section '%s'\n", 1053 fromsec, (long)faddr, tosec); 1054 } 1055 } 1056 check_export_symbol(struct module * mod,struct elf_info * elf,Elf_Addr faddr,const char * secname,Elf_Sym * sym)1057 static void check_export_symbol(struct module *mod, struct elf_info *elf, 1058 Elf_Addr faddr, const char *secname, 1059 Elf_Sym *sym) 1060 { 1061 static const char *prefix = "__export_symbol_"; 1062 const char *label_name, *name, *data; 1063 Elf_Sym *label; 1064 struct symbol *s; 1065 bool is_gpl; 1066 1067 label = find_fromsym(elf, faddr, elf->export_symbol_secndx); 1068 label_name = sym_name(elf, label); 1069 1070 if (!strstarts(label_name, prefix)) { 1071 error("%s: .export_symbol section contains strange symbol '%s'\n", 1072 mod->name, label_name); 1073 return; 1074 } 1075 1076 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 1077 ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1078 error("%s: local symbol '%s' was exported\n", mod->name, 1079 label_name + strlen(prefix)); 1080 return; 1081 } 1082 1083 name = sym_name(elf, sym); 1084 if (strcmp(label_name + strlen(prefix), name)) { 1085 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n", 1086 mod->name, name); 1087 return; 1088 } 1089 1090 data = sym_get_data(elf, label); /* license */ 1091 if (!strcmp(data, "GPL")) { 1092 is_gpl = true; 1093 } else if (!strcmp(data, "")) { 1094 is_gpl = false; 1095 } else { 1096 error("%s: unknown license '%s' was specified for '%s'\n", 1097 mod->name, data, name); 1098 return; 1099 } 1100 1101 data += strlen(data) + 1; /* namespace */ 1102 s = sym_add_exported(name, mod, is_gpl, data); 1103 1104 /* 1105 * We need to be aware whether we are exporting a function or 1106 * a data on some architectures. 1107 */ 1108 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC); 1109 1110 /* 1111 * For parisc64, symbols prefixed $$ from the library have the symbol type 1112 * STT_LOPROC. They should be handled as functions too. 1113 */ 1114 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 && 1115 elf->hdr->e_machine == EM_PARISC && 1116 ELF_ST_TYPE(sym->st_info) == STT_LOPROC) 1117 s->is_func = true; 1118 1119 if (match(secname, PATTERNS(ALL_INIT_SECTIONS))) 1120 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n", 1121 mod->name, name); 1122 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS))) 1123 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n", 1124 mod->name, name); 1125 } 1126 check_section_mismatch(struct module * mod,struct elf_info * elf,Elf_Sym * sym,unsigned int fsecndx,const char * fromsec,Elf_Addr faddr,Elf_Addr taddr)1127 static void check_section_mismatch(struct module *mod, struct elf_info *elf, 1128 Elf_Sym *sym, 1129 unsigned int fsecndx, const char *fromsec, 1130 Elf_Addr faddr, Elf_Addr taddr) 1131 { 1132 const char *tosec = sec_name(elf, get_secindex(elf, sym)); 1133 const struct sectioncheck *mismatch; 1134 1135 if (module_enabled && elf->export_symbol_secndx == fsecndx) { 1136 check_export_symbol(mod, elf, faddr, tosec, sym); 1137 return; 1138 } 1139 1140 mismatch = section_mismatch(fromsec, tosec); 1141 if (!mismatch) 1142 return; 1143 1144 default_mismatch_handler(mod->name, elf, mismatch, sym, 1145 fsecndx, fromsec, faddr, 1146 tosec, taddr); 1147 } 1148 addend_386_rel(uint32_t * location,unsigned int r_type)1149 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type) 1150 { 1151 switch (r_type) { 1152 case R_386_32: 1153 return TO_NATIVE(*location); 1154 case R_386_PC32: 1155 return TO_NATIVE(*location) + 4; 1156 } 1157 1158 return (Elf_Addr)(-1); 1159 } 1160 sign_extend32(int32_t value,int index)1161 static int32_t sign_extend32(int32_t value, int index) 1162 { 1163 uint8_t shift = 31 - index; 1164 1165 return (int32_t)(value << shift) >> shift; 1166 } 1167 addend_arm_rel(void * loc,Elf_Sym * sym,unsigned int r_type)1168 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type) 1169 { 1170 uint32_t inst, upper, lower, sign, j1, j2; 1171 int32_t offset; 1172 1173 switch (r_type) { 1174 case R_ARM_ABS32: 1175 case R_ARM_REL32: 1176 inst = TO_NATIVE(*(uint32_t *)loc); 1177 return inst + sym->st_value; 1178 case R_ARM_MOVW_ABS_NC: 1179 case R_ARM_MOVT_ABS: 1180 inst = TO_NATIVE(*(uint32_t *)loc); 1181 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff), 1182 15); 1183 return offset + sym->st_value; 1184 case R_ARM_PC24: 1185 case R_ARM_CALL: 1186 case R_ARM_JUMP24: 1187 inst = TO_NATIVE(*(uint32_t *)loc); 1188 offset = sign_extend32((inst & 0x00ffffff) << 2, 25); 1189 return offset + sym->st_value + 8; 1190 case R_ARM_THM_MOVW_ABS_NC: 1191 case R_ARM_THM_MOVT_ABS: 1192 upper = TO_NATIVE(*(uint16_t *)loc); 1193 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1194 offset = sign_extend32(((upper & 0x000f) << 12) | 1195 ((upper & 0x0400) << 1) | 1196 ((lower & 0x7000) >> 4) | 1197 (lower & 0x00ff), 1198 15); 1199 return offset + sym->st_value; 1200 case R_ARM_THM_JUMP19: 1201 /* 1202 * Encoding T3: 1203 * S = upper[10] 1204 * imm6 = upper[5:0] 1205 * J1 = lower[13] 1206 * J2 = lower[11] 1207 * imm11 = lower[10:0] 1208 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0') 1209 */ 1210 upper = TO_NATIVE(*(uint16_t *)loc); 1211 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1212 1213 sign = (upper >> 10) & 1; 1214 j1 = (lower >> 13) & 1; 1215 j2 = (lower >> 11) & 1; 1216 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) | 1217 ((upper & 0x03f) << 12) | 1218 ((lower & 0x07ff) << 1), 1219 20); 1220 return offset + sym->st_value + 4; 1221 case R_ARM_THM_PC22: 1222 case R_ARM_THM_JUMP24: 1223 /* 1224 * Encoding T4: 1225 * S = upper[10] 1226 * imm10 = upper[9:0] 1227 * J1 = lower[13] 1228 * J2 = lower[11] 1229 * imm11 = lower[10:0] 1230 * I1 = NOT(J1 XOR S) 1231 * I2 = NOT(J2 XOR S) 1232 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0') 1233 */ 1234 upper = TO_NATIVE(*(uint16_t *)loc); 1235 lower = TO_NATIVE(*((uint16_t *)loc + 1)); 1236 1237 sign = (upper >> 10) & 1; 1238 j1 = (lower >> 13) & 1; 1239 j2 = (lower >> 11) & 1; 1240 offset = sign_extend32((sign << 24) | 1241 ((~(j1 ^ sign) & 1) << 23) | 1242 ((~(j2 ^ sign) & 1) << 22) | 1243 ((upper & 0x03ff) << 12) | 1244 ((lower & 0x07ff) << 1), 1245 24); 1246 return offset + sym->st_value + 4; 1247 } 1248 1249 return (Elf_Addr)(-1); 1250 } 1251 addend_mips_rel(uint32_t * location,unsigned int r_type)1252 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 1253 { 1254 uint32_t inst; 1255 1256 inst = TO_NATIVE(*location); 1257 switch (r_type) { 1258 case R_MIPS_LO16: 1259 return inst & 0xffff; 1260 case R_MIPS_26: 1261 return (inst & 0x03ffffff) << 2; 1262 case R_MIPS_32: 1263 return inst; 1264 } 1265 return (Elf_Addr)(-1); 1266 } 1267 1268 #ifndef EM_RISCV 1269 #define EM_RISCV 243 1270 #endif 1271 1272 #ifndef R_RISCV_SUB32 1273 #define R_RISCV_SUB32 39 1274 #endif 1275 1276 #ifndef EM_LOONGARCH 1277 #define EM_LOONGARCH 258 1278 #endif 1279 1280 #ifndef R_LARCH_SUB32 1281 #define R_LARCH_SUB32 55 1282 #endif 1283 1284 #ifndef R_LARCH_RELAX 1285 #define R_LARCH_RELAX 100 1286 #endif 1287 1288 #ifndef R_LARCH_ALIGN 1289 #define R_LARCH_ALIGN 102 1290 #endif 1291 get_rel_type_and_sym(struct elf_info * elf,uint64_t r_info,unsigned int * r_type,unsigned int * r_sym)1292 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info, 1293 unsigned int *r_type, unsigned int *r_sym) 1294 { 1295 typedef struct { 1296 Elf64_Word r_sym; /* Symbol index */ 1297 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 1298 unsigned char r_type3; /* 3rd relocation type */ 1299 unsigned char r_type2; /* 2nd relocation type */ 1300 unsigned char r_type; /* 1st relocation type */ 1301 } Elf64_Mips_R_Info; 1302 1303 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64); 1304 1305 if (elf->hdr->e_machine == EM_MIPS && is_64bit) { 1306 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info; 1307 1308 *r_type = mips64_r_info->r_type; 1309 *r_sym = TO_NATIVE(mips64_r_info->r_sym); 1310 return; 1311 } 1312 1313 if (is_64bit) 1314 r_info = TO_NATIVE((Elf64_Xword)r_info); 1315 else 1316 r_info = TO_NATIVE((Elf32_Word)r_info); 1317 1318 *r_type = ELF_R_TYPE(r_info); 1319 *r_sym = ELF_R_SYM(r_info); 1320 } 1321 section_rela(struct module * mod,struct elf_info * elf,unsigned int fsecndx,const char * fromsec,const Elf_Rela * start,const Elf_Rela * stop)1322 static void section_rela(struct module *mod, struct elf_info *elf, 1323 unsigned int fsecndx, const char *fromsec, 1324 const Elf_Rela *start, const Elf_Rela *stop) 1325 { 1326 const Elf_Rela *rela; 1327 1328 for (rela = start; rela < stop; rela++) { 1329 Elf_Sym *tsym; 1330 Elf_Addr taddr, r_offset; 1331 unsigned int r_type, r_sym; 1332 1333 r_offset = TO_NATIVE(rela->r_offset); 1334 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); 1335 1336 tsym = elf->symtab_start + r_sym; 1337 taddr = tsym->st_value + TO_NATIVE(rela->r_addend); 1338 1339 switch (elf->hdr->e_machine) { 1340 case EM_RISCV: 1341 if (!strcmp("__ex_table", fromsec) && 1342 r_type == R_RISCV_SUB32) 1343 continue; 1344 break; 1345 case EM_LOONGARCH: 1346 switch (r_type) { 1347 case R_LARCH_SUB32: 1348 if (!strcmp("__ex_table", fromsec)) 1349 continue; 1350 break; 1351 case R_LARCH_RELAX: 1352 case R_LARCH_ALIGN: 1353 /* These relocs do not refer to symbols */ 1354 continue; 1355 } 1356 break; 1357 } 1358 1359 check_section_mismatch(mod, elf, tsym, 1360 fsecndx, fromsec, r_offset, taddr); 1361 } 1362 } 1363 section_rel(struct module * mod,struct elf_info * elf,unsigned int fsecndx,const char * fromsec,const Elf_Rel * start,const Elf_Rel * stop)1364 static void section_rel(struct module *mod, struct elf_info *elf, 1365 unsigned int fsecndx, const char *fromsec, 1366 const Elf_Rel *start, const Elf_Rel *stop) 1367 { 1368 const Elf_Rel *rel; 1369 1370 for (rel = start; rel < stop; rel++) { 1371 Elf_Sym *tsym; 1372 Elf_Addr taddr, r_offset; 1373 unsigned int r_type, r_sym; 1374 void *loc; 1375 1376 r_offset = TO_NATIVE(rel->r_offset); 1377 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym); 1378 1379 loc = sym_get_data_by_offset(elf, fsecndx, r_offset); 1380 tsym = elf->symtab_start + r_sym; 1381 1382 switch (elf->hdr->e_machine) { 1383 case EM_386: 1384 taddr = addend_386_rel(loc, r_type); 1385 break; 1386 case EM_ARM: 1387 taddr = addend_arm_rel(loc, tsym, r_type); 1388 break; 1389 case EM_MIPS: 1390 taddr = addend_mips_rel(loc, r_type); 1391 break; 1392 default: 1393 fatal("Please add code to calculate addend for this architecture\n"); 1394 } 1395 1396 check_section_mismatch(mod, elf, tsym, 1397 fsecndx, fromsec, r_offset, taddr); 1398 } 1399 } 1400 1401 /** 1402 * A module includes a number of sections that are discarded 1403 * either when loaded or when used as built-in. 1404 * For loaded modules all functions marked __init and all data 1405 * marked __initdata will be discarded when the module has been initialized. 1406 * Likewise for modules used built-in the sections marked __exit 1407 * are discarded because __exit marked function are supposed to be called 1408 * only when a module is unloaded which never happens for built-in modules. 1409 * The check_sec_ref() function traverses all relocation records 1410 * to find all references to a section that reference a section that will 1411 * be discarded and warns about it. 1412 **/ check_sec_ref(struct module * mod,struct elf_info * elf)1413 static void check_sec_ref(struct module *mod, struct elf_info *elf) 1414 { 1415 int i; 1416 1417 /* Walk through all sections */ 1418 for (i = 0; i < elf->num_sections; i++) { 1419 Elf_Shdr *sechdr = &elf->sechdrs[i]; 1420 1421 check_section(mod->name, elf, sechdr); 1422 /* We want to process only relocation sections and not .init */ 1423 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) { 1424 /* section to which the relocation applies */ 1425 unsigned int secndx = sechdr->sh_info; 1426 const char *secname = sec_name(elf, secndx); 1427 const void *start, *stop; 1428 1429 /* If the section is known good, skip it */ 1430 if (match(secname, section_white_list)) 1431 continue; 1432 1433 start = sym_get_data_by_offset(elf, i, 0); 1434 stop = start + sechdr->sh_size; 1435 1436 if (sechdr->sh_type == SHT_RELA) 1437 section_rela(mod, elf, secndx, secname, 1438 start, stop); 1439 else 1440 section_rel(mod, elf, secndx, secname, 1441 start, stop); 1442 } 1443 } 1444 } 1445 remove_dot(char * s)1446 static char *remove_dot(char *s) 1447 { 1448 size_t n = strcspn(s, "."); 1449 1450 if (n && s[n]) { 1451 size_t m = strspn(s + n + 1, "0123456789"); 1452 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) 1453 s[n] = 0; 1454 } 1455 return s; 1456 } 1457 1458 /* 1459 * The CRCs are recorded in .*.cmd files in the form of: 1460 * #SYMVER <name> <crc> 1461 */ extract_crcs_for_object(const char * object,struct module * mod)1462 static void extract_crcs_for_object(const char *object, struct module *mod) 1463 { 1464 char cmd_file[PATH_MAX]; 1465 char *buf, *p; 1466 const char *base; 1467 int dirlen, ret; 1468 1469 base = strrchr(object, '/'); 1470 if (base) { 1471 base++; 1472 dirlen = base - object; 1473 } else { 1474 dirlen = 0; 1475 base = object; 1476 } 1477 1478 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", 1479 dirlen, object, base); 1480 if (ret >= sizeof(cmd_file)) { 1481 error("%s: too long path was truncated\n", cmd_file); 1482 return; 1483 } 1484 1485 buf = read_text_file(cmd_file); 1486 p = buf; 1487 1488 while ((p = strstr(p, "\n#SYMVER "))) { 1489 char *name; 1490 size_t namelen; 1491 unsigned int crc; 1492 struct symbol *sym; 1493 1494 name = p + strlen("\n#SYMVER "); 1495 1496 p = strchr(name, ' '); 1497 if (!p) 1498 break; 1499 1500 namelen = p - name; 1501 p++; 1502 1503 if (!isdigit(*p)) 1504 continue; /* skip this line */ 1505 1506 crc = strtoul(p, &p, 0); 1507 if (*p != '\n') 1508 continue; /* skip this line */ 1509 1510 name[namelen] = '\0'; 1511 1512 /* 1513 * sym_find_with_module() may return NULL here. 1514 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. 1515 * Since commit e1327a127703, genksyms calculates CRCs of all 1516 * symbols, including trimmed ones. Ignore orphan CRCs. 1517 */ 1518 sym = sym_find_with_module(name, mod); 1519 if (sym) 1520 sym_set_crc(sym, crc); 1521 } 1522 1523 free(buf); 1524 } 1525 1526 /* 1527 * The symbol versions (CRC) are recorded in the .*.cmd files. 1528 * Parse them to retrieve CRCs for the current module. 1529 */ mod_set_crcs(struct module * mod)1530 static void mod_set_crcs(struct module *mod) 1531 { 1532 char objlist[PATH_MAX]; 1533 char *buf, *p, *obj; 1534 int ret; 1535 1536 if (mod->is_vmlinux) { 1537 strcpy(objlist, ".vmlinux.objs"); 1538 } else { 1539 /* objects for a module are listed in the *.mod file. */ 1540 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); 1541 if (ret >= sizeof(objlist)) { 1542 error("%s: too long path was truncated\n", objlist); 1543 return; 1544 } 1545 } 1546 1547 buf = read_text_file(objlist); 1548 p = buf; 1549 1550 while ((obj = strsep(&p, "\n")) && obj[0]) 1551 extract_crcs_for_object(obj, mod); 1552 1553 free(buf); 1554 } 1555 read_symbols(const char * modname)1556 static void read_symbols(const char *modname) 1557 { 1558 const char *symname; 1559 char *version; 1560 char *license; 1561 char *namespace; 1562 struct module *mod; 1563 struct elf_info info = { }; 1564 Elf_Sym *sym; 1565 1566 if (!parse_elf(&info, modname)) 1567 return; 1568 1569 if (!strends(modname, ".o")) { 1570 error("%s: filename must be suffixed with .o\n", modname); 1571 return; 1572 } 1573 1574 /* strip trailing .o */ 1575 mod = new_module(modname, strlen(modname) - strlen(".o")); 1576 1577 if (!mod->is_vmlinux) { 1578 license = get_modinfo(&info, "license"); 1579 if (!license) 1580 error("missing MODULE_LICENSE() in %s\n", modname); 1581 while (license) { 1582 if (!license_is_gpl_compatible(license)) { 1583 mod->is_gpl_compatible = false; 1584 break; 1585 } 1586 license = get_next_modinfo(&info, "license", license); 1587 } 1588 1589 namespace = get_modinfo(&info, "import_ns"); 1590 while (namespace) { 1591 add_namespace(&mod->imported_namespaces, namespace); 1592 namespace = get_next_modinfo(&info, "import_ns", 1593 namespace); 1594 } 1595 1596 if (extra_warn && !get_modinfo(&info, "description")) 1597 warn("missing MODULE_DESCRIPTION() in %s\n", modname); 1598 } 1599 1600 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1601 symname = remove_dot(info.strtab + sym->st_name); 1602 1603 handle_symbol(mod, &info, sym, symname); 1604 handle_moddevtable(mod, &info, sym, symname); 1605 } 1606 1607 check_sec_ref(mod, &info); 1608 1609 if (!mod->is_vmlinux) { 1610 version = get_modinfo(&info, "version"); 1611 if (version || all_versions) 1612 get_src_version(mod->name, mod->srcversion, 1613 sizeof(mod->srcversion) - 1); 1614 } 1615 1616 parse_elf_finish(&info); 1617 1618 if (modversions) { 1619 /* 1620 * Our trick to get versioning for module struct etc. - it's 1621 * never passed as an argument to an exported function, so 1622 * the automatic versioning doesn't pick it up, but it's really 1623 * important anyhow. 1624 */ 1625 sym_add_unresolved("module_layout", mod, false); 1626 1627 mod_set_crcs(mod); 1628 } 1629 } 1630 read_symbols_from_files(const char * filename)1631 static void read_symbols_from_files(const char *filename) 1632 { 1633 FILE *in = stdin; 1634 char fname[PATH_MAX]; 1635 1636 in = fopen(filename, "r"); 1637 if (!in) 1638 fatal("Can't open filenames file %s: %m", filename); 1639 1640 while (fgets(fname, PATH_MAX, in) != NULL) { 1641 if (strends(fname, "\n")) 1642 fname[strlen(fname)-1] = '\0'; 1643 read_symbols(fname); 1644 } 1645 1646 fclose(in); 1647 } 1648 1649 #define SZ 500 1650 1651 /* We first write the generated file into memory using the 1652 * following helper, then compare to the file on disk and 1653 * only update the later if anything changed */ 1654 buf_printf(struct buffer * buf,const char * fmt,...)1655 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1656 const char *fmt, ...) 1657 { 1658 char tmp[SZ]; 1659 int len; 1660 va_list ap; 1661 1662 va_start(ap, fmt); 1663 len = vsnprintf(tmp, SZ, fmt, ap); 1664 buf_write(buf, tmp, len); 1665 va_end(ap); 1666 } 1667 buf_write(struct buffer * buf,const char * s,int len)1668 void buf_write(struct buffer *buf, const char *s, int len) 1669 { 1670 if (buf->size - buf->pos < len) { 1671 buf->size += len + SZ; 1672 buf->p = xrealloc(buf->p, buf->size); 1673 } 1674 strncpy(buf->p + buf->pos, s, len); 1675 buf->pos += len; 1676 } 1677 check_exports(struct module * mod)1678 static void check_exports(struct module *mod) 1679 { 1680 struct symbol *s, *exp; 1681 1682 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1683 const char *basename; 1684 exp = find_symbol(s->name); 1685 if (!exp) { 1686 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) 1687 modpost_log(!warn_unresolved, 1688 "\"%s\" [%s.ko] undefined!\n", 1689 s->name, mod->name); 1690 continue; 1691 } 1692 if (exp->module == mod) { 1693 error("\"%s\" [%s.ko] was exported without definition\n", 1694 s->name, mod->name); 1695 continue; 1696 } 1697 1698 exp->used = true; 1699 s->module = exp->module; 1700 s->crc_valid = exp->crc_valid; 1701 s->crc = exp->crc; 1702 1703 basename = strrchr(mod->name, '/'); 1704 if (basename) 1705 basename++; 1706 else 1707 basename = mod->name; 1708 1709 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) { 1710 modpost_log(!allow_missing_ns_imports, 1711 "module %s uses symbol %s from namespace %s, but does not import it.\n", 1712 basename, exp->name, exp->namespace); 1713 add_namespace(&mod->missing_namespaces, exp->namespace); 1714 } 1715 1716 if (!mod->is_gpl_compatible && exp->is_gpl_only) 1717 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", 1718 basename, exp->name); 1719 } 1720 } 1721 handle_white_list_exports(const char * white_list)1722 static void handle_white_list_exports(const char *white_list) 1723 { 1724 char *buf, *p, *name; 1725 1726 buf = read_text_file(white_list); 1727 p = buf; 1728 1729 while ((name = strsep(&p, "\n"))) { 1730 struct symbol *sym = find_symbol(name); 1731 1732 if (sym) 1733 sym->used = true; 1734 } 1735 1736 free(buf); 1737 } 1738 check_modname_len(struct module * mod)1739 static void check_modname_len(struct module *mod) 1740 { 1741 const char *mod_name; 1742 1743 mod_name = strrchr(mod->name, '/'); 1744 if (mod_name == NULL) 1745 mod_name = mod->name; 1746 else 1747 mod_name++; 1748 if (strlen(mod_name) >= MODULE_NAME_LEN) 1749 error("module name is too long [%s.ko]\n", mod->name); 1750 } 1751 1752 /** 1753 * Header for the generated file 1754 **/ add_header(struct buffer * b,struct module * mod)1755 static void add_header(struct buffer *b, struct module *mod) 1756 { 1757 buf_printf(b, "#include <linux/module.h>\n"); 1758 buf_printf(b, "#include <linux/export-internal.h>\n"); 1759 buf_printf(b, "#include <linux/compiler.h>\n"); 1760 buf_printf(b, "\n"); 1761 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); 1762 buf_printf(b, "\n"); 1763 buf_printf(b, "__visible struct module __this_module\n"); 1764 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); 1765 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1766 if (mod->has_init) 1767 buf_printf(b, "\t.init = init_module,\n"); 1768 if (mod->has_cleanup) 1769 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1770 "\t.exit = cleanup_module,\n" 1771 "#endif\n"); 1772 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1773 buf_printf(b, "};\n"); 1774 1775 if (!external_module) 1776 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1777 1778 if (strstarts(mod->name, "drivers/staging")) 1779 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1780 1781 if (strstarts(mod->name, "tools/testing")) 1782 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); 1783 } 1784 add_exported_symbols(struct buffer * buf,struct module * mod)1785 static void add_exported_symbols(struct buffer *buf, struct module *mod) 1786 { 1787 struct symbol *sym; 1788 1789 /* generate struct for exported symbols */ 1790 buf_printf(buf, "\n"); 1791 list_for_each_entry(sym, &mod->exported_symbols, list) { 1792 if (trim_unused_exports && !sym->used) 1793 continue; 1794 1795 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n", 1796 sym->is_func ? "FUNC" : "DATA", sym->name, 1797 sym->is_gpl_only ? "_gpl" : "", sym->namespace); 1798 } 1799 1800 if (!modversions) 1801 return; 1802 1803 /* record CRCs for exported symbols */ 1804 buf_printf(buf, "\n"); 1805 list_for_each_entry(sym, &mod->exported_symbols, list) { 1806 if (trim_unused_exports && !sym->used) 1807 continue; 1808 1809 if (!sym->crc_valid) 1810 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" 1811 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", 1812 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", 1813 sym->name); 1814 1815 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", 1816 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); 1817 } 1818 } 1819 1820 /** 1821 * Record CRCs for unresolved symbols 1822 **/ add_versions(struct buffer * b,struct module * mod)1823 static void add_versions(struct buffer *b, struct module *mod) 1824 { 1825 struct symbol *s; 1826 1827 if (!modversions) 1828 return; 1829 1830 buf_printf(b, "\n"); 1831 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1832 buf_printf(b, "__used __section(\"__versions\") = {\n"); 1833 1834 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1835 if (!s->module) 1836 continue; 1837 if (!s->crc_valid) { 1838 warn("\"%s\" [%s.ko] has no CRC!\n", 1839 s->name, mod->name); 1840 continue; 1841 } 1842 if (strlen(s->name) >= MODULE_NAME_LEN) { 1843 error("too long symbol \"%s\" [%s.ko]\n", 1844 s->name, mod->name); 1845 break; 1846 } 1847 buf_printf(b, "\t{ %#8x, \"%s\" },\n", 1848 s->crc, s->name); 1849 } 1850 1851 buf_printf(b, "};\n"); 1852 } 1853 add_depends(struct buffer * b,struct module * mod)1854 static void add_depends(struct buffer *b, struct module *mod) 1855 { 1856 struct symbol *s; 1857 int first = 1; 1858 1859 /* Clear ->seen flag of modules that own symbols needed by this. */ 1860 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1861 if (s->module) 1862 s->module->seen = s->module->is_vmlinux; 1863 } 1864 1865 buf_printf(b, "\n"); 1866 buf_printf(b, "MODULE_INFO(depends, \""); 1867 list_for_each_entry(s, &mod->unresolved_symbols, list) { 1868 const char *p; 1869 if (!s->module) 1870 continue; 1871 1872 if (s->module->seen) 1873 continue; 1874 1875 s->module->seen = true; 1876 p = strrchr(s->module->name, '/'); 1877 if (p) 1878 p++; 1879 else 1880 p = s->module->name; 1881 buf_printf(b, "%s%s", first ? "" : ",", p); 1882 first = 0; 1883 } 1884 buf_printf(b, "\");\n"); 1885 } 1886 add_srcversion(struct buffer * b,struct module * mod)1887 static void add_srcversion(struct buffer *b, struct module *mod) 1888 { 1889 if (mod->srcversion[0]) { 1890 buf_printf(b, "\n"); 1891 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1892 mod->srcversion); 1893 } 1894 } 1895 write_buf(struct buffer * b,const char * fname)1896 static void write_buf(struct buffer *b, const char *fname) 1897 { 1898 FILE *file; 1899 1900 if (error_occurred) 1901 return; 1902 1903 file = fopen(fname, "w"); 1904 if (!file) { 1905 perror(fname); 1906 exit(1); 1907 } 1908 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1909 perror(fname); 1910 exit(1); 1911 } 1912 if (fclose(file) != 0) { 1913 perror(fname); 1914 exit(1); 1915 } 1916 } 1917 write_if_changed(struct buffer * b,const char * fname)1918 static void write_if_changed(struct buffer *b, const char *fname) 1919 { 1920 char *tmp; 1921 FILE *file; 1922 struct stat st; 1923 1924 file = fopen(fname, "r"); 1925 if (!file) 1926 goto write; 1927 1928 if (fstat(fileno(file), &st) < 0) 1929 goto close_write; 1930 1931 if (st.st_size != b->pos) 1932 goto close_write; 1933 1934 tmp = xmalloc(b->pos); 1935 if (fread(tmp, 1, b->pos, file) != b->pos) 1936 goto free_write; 1937 1938 if (memcmp(tmp, b->p, b->pos) != 0) 1939 goto free_write; 1940 1941 free(tmp); 1942 fclose(file); 1943 return; 1944 1945 free_write: 1946 free(tmp); 1947 close_write: 1948 fclose(file); 1949 write: 1950 write_buf(b, fname); 1951 } 1952 write_vmlinux_export_c_file(struct module * mod)1953 static void write_vmlinux_export_c_file(struct module *mod) 1954 { 1955 struct buffer buf = { }; 1956 1957 buf_printf(&buf, 1958 "#include <linux/export-internal.h>\n"); 1959 1960 add_exported_symbols(&buf, mod); 1961 write_if_changed(&buf, ".vmlinux.export.c"); 1962 free(buf.p); 1963 } 1964 1965 /* do sanity checks, and generate *.mod.c file */ write_mod_c_file(struct module * mod)1966 static void write_mod_c_file(struct module *mod) 1967 { 1968 struct buffer buf = { }; 1969 char fname[PATH_MAX]; 1970 int ret; 1971 1972 add_header(&buf, mod); 1973 add_exported_symbols(&buf, mod); 1974 add_versions(&buf, mod); 1975 add_depends(&buf, mod); 1976 add_moddevtable(&buf, mod); 1977 add_srcversion(&buf, mod); 1978 1979 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); 1980 if (ret >= sizeof(fname)) { 1981 error("%s: too long path was truncated\n", fname); 1982 goto free; 1983 } 1984 1985 write_if_changed(&buf, fname); 1986 1987 free: 1988 free(buf.p); 1989 } 1990 1991 /* parse Module.symvers file. line format: 1992 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace 1993 **/ read_dump(const char * fname)1994 static void read_dump(const char *fname) 1995 { 1996 char *buf, *pos, *line; 1997 1998 buf = read_text_file(fname); 1999 if (!buf) 2000 /* No symbol versions, silently ignore */ 2001 return; 2002 2003 pos = buf; 2004 2005 while ((line = get_line(&pos))) { 2006 char *symname, *namespace, *modname, *d, *export; 2007 unsigned int crc; 2008 struct module *mod; 2009 struct symbol *s; 2010 bool gpl_only; 2011 2012 if (!(symname = strchr(line, '\t'))) 2013 goto fail; 2014 *symname++ = '\0'; 2015 if (!(modname = strchr(symname, '\t'))) 2016 goto fail; 2017 *modname++ = '\0'; 2018 if (!(export = strchr(modname, '\t'))) 2019 goto fail; 2020 *export++ = '\0'; 2021 if (!(namespace = strchr(export, '\t'))) 2022 goto fail; 2023 *namespace++ = '\0'; 2024 2025 crc = strtoul(line, &d, 16); 2026 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2027 goto fail; 2028 2029 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { 2030 gpl_only = true; 2031 } else if (!strcmp(export, "EXPORT_SYMBOL")) { 2032 gpl_only = false; 2033 } else { 2034 error("%s: unknown license %s. skip", symname, export); 2035 continue; 2036 } 2037 2038 mod = find_module(modname); 2039 if (!mod) { 2040 mod = new_module(modname, strlen(modname)); 2041 mod->from_dump = true; 2042 } 2043 s = sym_add_exported(symname, mod, gpl_only, namespace); 2044 sym_set_crc(s, crc); 2045 } 2046 free(buf); 2047 return; 2048 fail: 2049 free(buf); 2050 fatal("parse error in symbol dump file\n"); 2051 } 2052 write_dump(const char * fname)2053 static void write_dump(const char *fname) 2054 { 2055 struct buffer buf = { }; 2056 struct module *mod; 2057 struct symbol *sym; 2058 2059 list_for_each_entry(mod, &modules, list) { 2060 if (mod->from_dump) 2061 continue; 2062 list_for_each_entry(sym, &mod->exported_symbols, list) { 2063 if (trim_unused_exports && !sym->used) 2064 continue; 2065 2066 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", 2067 sym->crc, sym->name, mod->name, 2068 sym->is_gpl_only ? "_GPL" : "", 2069 sym->namespace); 2070 } 2071 } 2072 write_buf(&buf, fname); 2073 free(buf.p); 2074 } 2075 write_namespace_deps_files(const char * fname)2076 static void write_namespace_deps_files(const char *fname) 2077 { 2078 struct module *mod; 2079 struct namespace_list *ns; 2080 struct buffer ns_deps_buf = {}; 2081 2082 list_for_each_entry(mod, &modules, list) { 2083 2084 if (mod->from_dump || list_empty(&mod->missing_namespaces)) 2085 continue; 2086 2087 buf_printf(&ns_deps_buf, "%s.ko:", mod->name); 2088 2089 list_for_each_entry(ns, &mod->missing_namespaces, list) 2090 buf_printf(&ns_deps_buf, " %s", ns->namespace); 2091 2092 buf_printf(&ns_deps_buf, "\n"); 2093 } 2094 2095 write_if_changed(&ns_deps_buf, fname); 2096 free(ns_deps_buf.p); 2097 } 2098 2099 struct dump_list { 2100 struct list_head list; 2101 const char *file; 2102 }; 2103 check_host_endian(void)2104 static void check_host_endian(void) 2105 { 2106 static const union { 2107 short s; 2108 char c[2]; 2109 } endian_test = { .c = {0x01, 0x02} }; 2110 2111 switch (endian_test.s) { 2112 case 0x0102: 2113 host_is_big_endian = true; 2114 break; 2115 case 0x0201: 2116 host_is_big_endian = false; 2117 break; 2118 default: 2119 fatal("Unknown host endian\n"); 2120 } 2121 } 2122 main(int argc,char ** argv)2123 int main(int argc, char **argv) 2124 { 2125 struct module *mod; 2126 char *missing_namespace_deps = NULL; 2127 char *unused_exports_white_list = NULL; 2128 char *dump_write = NULL, *files_source = NULL; 2129 int opt; 2130 LIST_HEAD(dump_lists); 2131 struct dump_list *dl, *dl2; 2132 2133 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) { 2134 switch (opt) { 2135 case 'e': 2136 external_module = true; 2137 break; 2138 case 'i': 2139 dl = xmalloc(sizeof(*dl)); 2140 dl->file = optarg; 2141 list_add_tail(&dl->list, &dump_lists); 2142 break; 2143 case 'M': 2144 module_enabled = true; 2145 break; 2146 case 'm': 2147 modversions = true; 2148 break; 2149 case 'n': 2150 ignore_missing_files = true; 2151 break; 2152 case 'o': 2153 dump_write = optarg; 2154 break; 2155 case 'a': 2156 all_versions = true; 2157 break; 2158 case 'T': 2159 files_source = optarg; 2160 break; 2161 case 't': 2162 trim_unused_exports = true; 2163 break; 2164 case 'u': 2165 unused_exports_white_list = optarg; 2166 break; 2167 case 'W': 2168 extra_warn = true; 2169 break; 2170 case 'w': 2171 warn_unresolved = true; 2172 break; 2173 case 'E': 2174 sec_mismatch_warn_only = false; 2175 break; 2176 case 'N': 2177 allow_missing_ns_imports = true; 2178 break; 2179 case 'd': 2180 missing_namespace_deps = optarg; 2181 break; 2182 default: 2183 exit(1); 2184 } 2185 } 2186 2187 check_host_endian(); 2188 2189 list_for_each_entry_safe(dl, dl2, &dump_lists, list) { 2190 read_dump(dl->file); 2191 list_del(&dl->list); 2192 free(dl); 2193 } 2194 2195 while (optind < argc) 2196 read_symbols(argv[optind++]); 2197 2198 if (files_source) 2199 read_symbols_from_files(files_source); 2200 2201 list_for_each_entry(mod, &modules, list) { 2202 if (mod->from_dump || mod->is_vmlinux) 2203 continue; 2204 2205 check_modname_len(mod); 2206 check_exports(mod); 2207 } 2208 2209 if (unused_exports_white_list) 2210 handle_white_list_exports(unused_exports_white_list); 2211 2212 list_for_each_entry(mod, &modules, list) { 2213 if (mod->from_dump) 2214 continue; 2215 2216 if (mod->is_vmlinux) 2217 write_vmlinux_export_c_file(mod); 2218 else 2219 write_mod_c_file(mod); 2220 } 2221 2222 if (missing_namespace_deps) 2223 write_namespace_deps_files(missing_namespace_deps); 2224 2225 if (dump_write) 2226 write_dump(dump_write); 2227 if (sec_mismatch_count && !sec_mismatch_warn_only) 2228 error("Section mismatches detected.\n" 2229 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); 2230 2231 if (nr_unresolved > MAX_UNRESOLVED_REPORTS) 2232 warn("suppressed %u unresolved symbol warnings because there were too many)\n", 2233 nr_unresolved - MAX_UNRESOLVED_REPORTS); 2234 2235 return error_occurred ? 1 : 0; 2236 } 2237