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 <stdio.h> 16 #include <ctype.h> 17 #include <string.h> 18 #include "modpost.h" 19 #include "../../include/generated/autoconf.h" 20 #include "../../include/linux/license.h" 21 22 /* Some toolchains use a `_' prefix for all user symbols. */ 23 #ifdef CONFIG_SYMBOL_PREFIX 24 #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX 25 #else 26 #define MODULE_SYMBOL_PREFIX "" 27 #endif 28 29 30 /* Are we using CONFIG_MODVERSIONS? */ 31 int modversions = 0; 32 /* Warn about undefined symbols? (do so if we have vmlinux) */ 33 int have_vmlinux = 0; 34 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 35 static int all_versions = 0; 36 /* If we are modposting external module set to 1 */ 37 static int external_module = 0; 38 /* Warn about section mismatch in vmlinux if set to 1 */ 39 static int vmlinux_section_warnings = 1; 40 /* Only warn about unresolved symbols */ 41 static int warn_unresolved = 0; 42 /* How a symbol is exported */ 43 static int sec_mismatch_count = 0; 44 static int sec_mismatch_verbose = 1; 45 46 enum export { 47 export_plain, export_unused, export_gpl, 48 export_unused_gpl, export_gpl_future, export_unknown 49 }; 50 51 #define PRINTF __attribute__ ((format (printf, 1, 2))) 52 53 PRINTF void fatal(const char *fmt, ...) 54 { 55 va_list arglist; 56 57 fprintf(stderr, "FATAL: "); 58 59 va_start(arglist, fmt); 60 vfprintf(stderr, fmt, arglist); 61 va_end(arglist); 62 63 exit(1); 64 } 65 66 PRINTF void warn(const char *fmt, ...) 67 { 68 va_list arglist; 69 70 fprintf(stderr, "WARNING: "); 71 72 va_start(arglist, fmt); 73 vfprintf(stderr, fmt, arglist); 74 va_end(arglist); 75 } 76 77 PRINTF void merror(const char *fmt, ...) 78 { 79 va_list arglist; 80 81 fprintf(stderr, "ERROR: "); 82 83 va_start(arglist, fmt); 84 vfprintf(stderr, fmt, arglist); 85 va_end(arglist); 86 } 87 88 static int is_vmlinux(const char *modname) 89 { 90 const char *myname; 91 92 myname = strrchr(modname, '/'); 93 if (myname) 94 myname++; 95 else 96 myname = modname; 97 98 return (strcmp(myname, "vmlinux") == 0) || 99 (strcmp(myname, "vmlinux.o") == 0); 100 } 101 102 void *do_nofail(void *ptr, const char *expr) 103 { 104 if (!ptr) 105 fatal("modpost: Memory allocation failure: %s.\n", expr); 106 107 return ptr; 108 } 109 110 /* A list of all modules we processed */ 111 static struct module *modules; 112 113 static struct module *find_module(char *modname) 114 { 115 struct module *mod; 116 117 for (mod = modules; mod; mod = mod->next) 118 if (strcmp(mod->name, modname) == 0) 119 break; 120 return mod; 121 } 122 123 static struct module *new_module(char *modname) 124 { 125 struct module *mod; 126 char *p, *s; 127 128 mod = NOFAIL(malloc(sizeof(*mod))); 129 memset(mod, 0, sizeof(*mod)); 130 p = NOFAIL(strdup(modname)); 131 132 /* strip trailing .o */ 133 s = strrchr(p, '.'); 134 if (s != NULL) 135 if (strcmp(s, ".o") == 0) 136 *s = '\0'; 137 138 /* add to list */ 139 mod->name = p; 140 mod->gpl_compatible = -1; 141 mod->next = modules; 142 modules = mod; 143 144 return mod; 145 } 146 147 /* A hash of all exported symbols, 148 * struct symbol is also used for lists of unresolved symbols */ 149 150 #define SYMBOL_HASH_SIZE 1024 151 152 struct symbol { 153 struct symbol *next; 154 struct module *module; 155 unsigned int crc; 156 int crc_valid; 157 unsigned int weak:1; 158 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */ 159 unsigned int kernel:1; /* 1 if symbol is from kernel 160 * (only for external modules) **/ 161 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */ 162 enum export export; /* Type of export */ 163 char name[0]; 164 }; 165 166 static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 167 168 /* This is based on the hash agorithm from gdbm, via tdb */ 169 static inline unsigned int tdb_hash(const char *name) 170 { 171 unsigned value; /* Used to compute the hash value. */ 172 unsigned i; /* Used to cycle through random values. */ 173 174 /* Set the initial value from the key size. */ 175 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++) 176 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 177 178 return (1103515243 * value + 12345); 179 } 180 181 /** 182 * Allocate a new symbols for use in the hash of exported symbols or 183 * the list of unresolved symbols per module 184 **/ 185 static struct symbol *alloc_symbol(const char *name, unsigned int weak, 186 struct symbol *next) 187 { 188 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 189 190 memset(s, 0, sizeof(*s)); 191 strcpy(s->name, name); 192 s->weak = weak; 193 s->next = next; 194 return s; 195 } 196 197 /* For the hash of exported symbols */ 198 static struct symbol *new_symbol(const char *name, struct module *module, 199 enum export export) 200 { 201 unsigned int hash; 202 struct symbol *new; 203 204 hash = tdb_hash(name) % SYMBOL_HASH_SIZE; 205 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]); 206 new->module = module; 207 new->export = export; 208 return new; 209 } 210 211 static struct symbol *find_symbol(const char *name) 212 { 213 struct symbol *s; 214 215 /* For our purposes, .foo matches foo. PPC64 needs this. */ 216 if (name[0] == '.') 217 name++; 218 219 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) { 220 if (strcmp(s->name, name) == 0) 221 return s; 222 } 223 return NULL; 224 } 225 226 static struct { 227 const char *str; 228 enum export export; 229 } export_list[] = { 230 { .str = "EXPORT_SYMBOL", .export = export_plain }, 231 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused }, 232 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl }, 233 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl }, 234 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future }, 235 { .str = "(unknown)", .export = export_unknown }, 236 }; 237 238 239 static const char *export_str(enum export ex) 240 { 241 return export_list[ex].str; 242 } 243 244 static enum export export_no(const char *s) 245 { 246 int i; 247 248 if (!s) 249 return export_unknown; 250 for (i = 0; export_list[i].export != export_unknown; i++) { 251 if (strcmp(export_list[i].str, s) == 0) 252 return export_list[i].export; 253 } 254 return export_unknown; 255 } 256 257 static enum export export_from_sec(struct elf_info *elf, unsigned int sec) 258 { 259 if (sec == elf->export_sec) 260 return export_plain; 261 else if (sec == elf->export_unused_sec) 262 return export_unused; 263 else if (sec == elf->export_gpl_sec) 264 return export_gpl; 265 else if (sec == elf->export_unused_gpl_sec) 266 return export_unused_gpl; 267 else if (sec == elf->export_gpl_future_sec) 268 return export_gpl_future; 269 else 270 return export_unknown; 271 } 272 273 /** 274 * Add an exported symbol - it may have already been added without a 275 * CRC, in this case just update the CRC 276 **/ 277 static struct symbol *sym_add_exported(const char *name, struct module *mod, 278 enum export export) 279 { 280 struct symbol *s = find_symbol(name); 281 282 if (!s) { 283 s = new_symbol(name, mod, export); 284 } else { 285 if (!s->preloaded) { 286 warn("%s: '%s' exported twice. Previous export " 287 "was in %s%s\n", mod->name, name, 288 s->module->name, 289 is_vmlinux(s->module->name) ?"":".ko"); 290 } else { 291 /* In case Modules.symvers was out of date */ 292 s->module = mod; 293 } 294 } 295 s->preloaded = 0; 296 s->vmlinux = is_vmlinux(mod->name); 297 s->kernel = 0; 298 s->export = export; 299 return s; 300 } 301 302 static void sym_update_crc(const char *name, struct module *mod, 303 unsigned int crc, enum export export) 304 { 305 struct symbol *s = find_symbol(name); 306 307 if (!s) 308 s = new_symbol(name, mod, export); 309 s->crc = crc; 310 s->crc_valid = 1; 311 } 312 313 void *grab_file(const char *filename, unsigned long *size) 314 { 315 struct stat st; 316 void *map; 317 int fd; 318 319 fd = open(filename, O_RDONLY); 320 if (fd < 0 || fstat(fd, &st) != 0) 321 return NULL; 322 323 *size = st.st_size; 324 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 325 close(fd); 326 327 if (map == MAP_FAILED) 328 return NULL; 329 return map; 330 } 331 332 /** 333 * Return a copy of the next line in a mmap'ed file. 334 * spaces in the beginning of the line is trimmed away. 335 * Return a pointer to a static buffer. 336 **/ 337 char *get_next_line(unsigned long *pos, void *file, unsigned long size) 338 { 339 static char line[4096]; 340 int skip = 1; 341 size_t len = 0; 342 signed char *p = (signed char *)file + *pos; 343 char *s = line; 344 345 for (; *pos < size ; (*pos)++) { 346 if (skip && isspace(*p)) { 347 p++; 348 continue; 349 } 350 skip = 0; 351 if (*p != '\n' && (*pos < size)) { 352 len++; 353 *s++ = *p++; 354 if (len > 4095) 355 break; /* Too long, stop */ 356 } else { 357 /* End of string */ 358 *s = '\0'; 359 return line; 360 } 361 } 362 /* End of buffer */ 363 return NULL; 364 } 365 366 void release_file(void *file, unsigned long size) 367 { 368 munmap(file, size); 369 } 370 371 static int parse_elf(struct elf_info *info, const char *filename) 372 { 373 unsigned int i; 374 Elf_Ehdr *hdr; 375 Elf_Shdr *sechdrs; 376 Elf_Sym *sym; 377 const char *secstrings; 378 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 379 380 hdr = grab_file(filename, &info->size); 381 if (!hdr) { 382 perror(filename); 383 exit(1); 384 } 385 info->hdr = hdr; 386 if (info->size < sizeof(*hdr)) { 387 /* file too small, assume this is an empty .o file */ 388 return 0; 389 } 390 /* Is this a valid ELF file? */ 391 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 392 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 393 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 394 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 395 /* Not an ELF file - silently ignore it */ 396 return 0; 397 } 398 /* Fix endianness in ELF header */ 399 hdr->e_type = TO_NATIVE(hdr->e_type); 400 hdr->e_machine = TO_NATIVE(hdr->e_machine); 401 hdr->e_version = TO_NATIVE(hdr->e_version); 402 hdr->e_entry = TO_NATIVE(hdr->e_entry); 403 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 404 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 405 hdr->e_flags = TO_NATIVE(hdr->e_flags); 406 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 407 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 408 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 409 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 410 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 411 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 412 sechdrs = (void *)hdr + hdr->e_shoff; 413 info->sechdrs = sechdrs; 414 415 /* Check if file offset is correct */ 416 if (hdr->e_shoff > info->size) { 417 fatal("section header offset=%lu in file '%s' is bigger than " 418 "filesize=%lu\n", (unsigned long)hdr->e_shoff, 419 filename, info->size); 420 return 0; 421 } 422 423 if (hdr->e_shnum == SHN_UNDEF) { 424 /* 425 * There are more than 64k sections, 426 * read count from .sh_size. 427 */ 428 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 429 } 430 else { 431 info->num_sections = hdr->e_shnum; 432 } 433 if (hdr->e_shstrndx == SHN_XINDEX) { 434 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 435 } 436 else { 437 info->secindex_strings = hdr->e_shstrndx; 438 } 439 440 /* Fix endianness in section headers */ 441 for (i = 0; i < info->num_sections; i++) { 442 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 443 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 444 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 445 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 446 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 447 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 448 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 449 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 450 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 451 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 452 } 453 /* Find symbol table. */ 454 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 455 for (i = 1; i < info->num_sections; i++) { 456 const char *secname; 457 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 458 459 if (!nobits && sechdrs[i].sh_offset > info->size) { 460 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > " 461 "sizeof(*hrd)=%zu\n", filename, 462 (unsigned long)sechdrs[i].sh_offset, 463 sizeof(*hdr)); 464 return 0; 465 } 466 secname = secstrings + sechdrs[i].sh_name; 467 if (strcmp(secname, ".modinfo") == 0) { 468 if (nobits) 469 fatal("%s has NOBITS .modinfo\n", filename); 470 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 471 info->modinfo_len = sechdrs[i].sh_size; 472 } else if (strcmp(secname, "__ksymtab") == 0) 473 info->export_sec = i; 474 else if (strcmp(secname, "__ksymtab_unused") == 0) 475 info->export_unused_sec = i; 476 else if (strcmp(secname, "__ksymtab_gpl") == 0) 477 info->export_gpl_sec = i; 478 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0) 479 info->export_unused_gpl_sec = i; 480 else if (strcmp(secname, "__ksymtab_gpl_future") == 0) 481 info->export_gpl_future_sec = i; 482 483 if (sechdrs[i].sh_type == SHT_SYMTAB) { 484 unsigned int sh_link_idx; 485 symtab_idx = i; 486 info->symtab_start = (void *)hdr + 487 sechdrs[i].sh_offset; 488 info->symtab_stop = (void *)hdr + 489 sechdrs[i].sh_offset + sechdrs[i].sh_size; 490 sh_link_idx = sechdrs[i].sh_link; 491 info->strtab = (void *)hdr + 492 sechdrs[sh_link_idx].sh_offset; 493 } 494 495 /* 32bit section no. table? ("more than 64k sections") */ 496 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 497 symtab_shndx_idx = i; 498 info->symtab_shndx_start = (void *)hdr + 499 sechdrs[i].sh_offset; 500 info->symtab_shndx_stop = (void *)hdr + 501 sechdrs[i].sh_offset + sechdrs[i].sh_size; 502 } 503 } 504 if (!info->symtab_start) 505 fatal("%s has no symtab?\n", filename); 506 507 /* Fix endianness in symbols */ 508 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 509 sym->st_shndx = TO_NATIVE(sym->st_shndx); 510 sym->st_name = TO_NATIVE(sym->st_name); 511 sym->st_value = TO_NATIVE(sym->st_value); 512 sym->st_size = TO_NATIVE(sym->st_size); 513 } 514 515 if (symtab_shndx_idx != ~0U) { 516 Elf32_Word *p; 517 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 518 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 519 filename, sechdrs[symtab_shndx_idx].sh_link, 520 symtab_idx); 521 /* Fix endianness */ 522 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 523 p++) 524 *p = TO_NATIVE(*p); 525 } 526 527 return 1; 528 } 529 530 static void parse_elf_finish(struct elf_info *info) 531 { 532 release_file(info->hdr, info->size); 533 } 534 535 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 536 { 537 /* ignore __this_module, it will be resolved shortly */ 538 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0) 539 return 1; 540 /* ignore global offset table */ 541 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 542 return 1; 543 if (info->hdr->e_machine == EM_PPC) 544 /* Special register function linked on all modules during final link of .ko */ 545 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 || 546 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 || 547 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 || 548 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0) 549 return 1; 550 if (info->hdr->e_machine == EM_PPC64) 551 /* Special register function linked on all modules during final link of .ko */ 552 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 || 553 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0) 554 return 1; 555 /* Do not ignore this symbol */ 556 return 0; 557 } 558 559 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_" 560 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_" 561 562 static void handle_modversions(struct module *mod, struct elf_info *info, 563 Elf_Sym *sym, const char *symname) 564 { 565 unsigned int crc; 566 enum export export = export_from_sec(info, get_secindex(info, sym)); 567 568 switch (sym->st_shndx) { 569 case SHN_COMMON: 570 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 571 break; 572 case SHN_ABS: 573 /* CRC'd symbol */ 574 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { 575 crc = (unsigned int) sym->st_value; 576 sym_update_crc(symname + strlen(CRC_PFX), mod, crc, 577 export); 578 } 579 break; 580 case SHN_UNDEF: 581 /* undefined symbol */ 582 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 583 ELF_ST_BIND(sym->st_info) != STB_WEAK) 584 break; 585 if (ignore_undef_symbol(info, symname)) 586 break; 587 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */ 588 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER) 589 /* add compatibility with older glibc */ 590 #ifndef STT_SPARC_REGISTER 591 #define STT_SPARC_REGISTER STT_REGISTER 592 #endif 593 if (info->hdr->e_machine == EM_SPARC || 594 info->hdr->e_machine == EM_SPARCV9) { 595 /* Ignore register directives. */ 596 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 597 break; 598 if (symname[0] == '.') { 599 char *munged = strdup(symname); 600 munged[0] = '_'; 601 munged[1] = toupper(munged[1]); 602 symname = munged; 603 } 604 } 605 #endif 606 607 if (memcmp(symname, MODULE_SYMBOL_PREFIX, 608 strlen(MODULE_SYMBOL_PREFIX)) == 0) { 609 mod->unres = 610 alloc_symbol(symname + 611 strlen(MODULE_SYMBOL_PREFIX), 612 ELF_ST_BIND(sym->st_info) == STB_WEAK, 613 mod->unres); 614 } 615 break; 616 default: 617 /* All exported symbols */ 618 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) { 619 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod, 620 export); 621 } 622 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0) 623 mod->has_init = 1; 624 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0) 625 mod->has_cleanup = 1; 626 break; 627 } 628 } 629 630 /** 631 * Parse tag=value strings from .modinfo section 632 **/ 633 static char *next_string(char *string, unsigned long *secsize) 634 { 635 /* Skip non-zero chars */ 636 while (string[0]) { 637 string++; 638 if ((*secsize)-- <= 1) 639 return NULL; 640 } 641 642 /* Skip any zero padding. */ 643 while (!string[0]) { 644 string++; 645 if ((*secsize)-- <= 1) 646 return NULL; 647 } 648 return string; 649 } 650 651 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len, 652 const char *tag, char *info) 653 { 654 char *p; 655 unsigned int taglen = strlen(tag); 656 unsigned long size = modinfo_len; 657 658 if (info) { 659 size -= info - (char *)modinfo; 660 modinfo = next_string(info, &size); 661 } 662 663 for (p = modinfo; p; p = next_string(p, &size)) { 664 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 665 return p + taglen + 1; 666 } 667 return NULL; 668 } 669 670 static char *get_modinfo(void *modinfo, unsigned long modinfo_len, 671 const char *tag) 672 673 { 674 return get_next_modinfo(modinfo, modinfo_len, tag, NULL); 675 } 676 677 /** 678 * Test if string s ends in string sub 679 * return 0 if match 680 **/ 681 static int strrcmp(const char *s, const char *sub) 682 { 683 int slen, sublen; 684 685 if (!s || !sub) 686 return 1; 687 688 slen = strlen(s); 689 sublen = strlen(sub); 690 691 if ((slen == 0) || (sublen == 0)) 692 return 1; 693 694 if (sublen > slen) 695 return 1; 696 697 return memcmp(s + slen - sublen, sub, sublen); 698 } 699 700 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 701 { 702 if (sym) 703 return elf->strtab + sym->st_name; 704 else 705 return "(unknown)"; 706 } 707 708 static const char *sec_name(struct elf_info *elf, int secindex) 709 { 710 Elf_Shdr *sechdrs = elf->sechdrs; 711 return (void *)elf->hdr + 712 elf->sechdrs[elf->secindex_strings].sh_offset + 713 sechdrs[secindex].sh_name; 714 } 715 716 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr) 717 { 718 return (void *)elf->hdr + 719 elf->sechdrs[elf->secindex_strings].sh_offset + 720 sechdr->sh_name; 721 } 722 723 /* if sym is empty or point to a string 724 * like ".[0-9]+" then return 1. 725 * This is the optional prefix added by ld to some sections 726 */ 727 static int number_prefix(const char *sym) 728 { 729 if (*sym++ == '\0') 730 return 1; 731 if (*sym != '.') 732 return 0; 733 do { 734 char c = *sym++; 735 if (c < '0' || c > '9') 736 return 0; 737 } while (*sym); 738 return 1; 739 } 740 741 /* The pattern is an array of simple patterns. 742 * "foo" will match an exact string equal to "foo" 743 * "*foo" will match a string that ends with "foo" 744 * "foo*" will match a string that begins with "foo" 745 * "foo$" will match a string equal to "foo" or "foo.1" 746 * where the '1' can be any number including several digits. 747 * The $ syntax is for sections where ld append a dot number 748 * to make section name unique. 749 */ 750 static int match(const char *sym, const char * const pat[]) 751 { 752 const char *p; 753 while (*pat) { 754 p = *pat++; 755 const char *endp = p + strlen(p) - 1; 756 757 /* "*foo" */ 758 if (*p == '*') { 759 if (strrcmp(sym, p + 1) == 0) 760 return 1; 761 } 762 /* "foo*" */ 763 else if (*endp == '*') { 764 if (strncmp(sym, p, strlen(p) - 1) == 0) 765 return 1; 766 } 767 /* "foo$" */ 768 else if (*endp == '$') { 769 if (strncmp(sym, p, strlen(p) - 1) == 0) { 770 if (number_prefix(sym + strlen(p) - 1)) 771 return 1; 772 } 773 } 774 /* no wildcards */ 775 else { 776 if (strcmp(p, sym) == 0) 777 return 1; 778 } 779 } 780 /* no match */ 781 return 0; 782 } 783 784 /* sections that we do not want to do full section mismatch check on */ 785 static const char *section_white_list[] = 786 { 787 ".comment*", 788 ".debug*", 789 ".zdebug*", /* Compressed debug sections. */ 790 ".GCC-command-line", /* mn10300 */ 791 ".mdebug*", /* alpha, score, mips etc. */ 792 ".pdr", /* alpha, score, mips etc. */ 793 ".stab*", 794 ".note*", 795 ".got*", 796 ".toc*", 797 NULL 798 }; 799 800 /* 801 * This is used to find sections missing the SHF_ALLOC flag. 802 * The cause of this is often a section specified in assembler 803 * without "ax" / "aw". 804 */ 805 static void check_section(const char *modname, struct elf_info *elf, 806 Elf_Shdr *sechdr) 807 { 808 const char *sec = sech_name(elf, sechdr); 809 810 if (sechdr->sh_type == SHT_PROGBITS && 811 !(sechdr->sh_flags & SHF_ALLOC) && 812 !match(sec, section_white_list)) { 813 warn("%s (%s): unexpected non-allocatable section.\n" 814 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 815 "Note that for example <linux/init.h> contains\n" 816 "section definitions for use in .S files.\n\n", 817 modname, sec); 818 } 819 } 820 821 822 823 #define ALL_INIT_DATA_SECTIONS \ 824 ".init.setup$", ".init.rodata$", \ 825 ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$" \ 826 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$" 827 #define ALL_EXIT_DATA_SECTIONS \ 828 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$" 829 830 #define ALL_INIT_TEXT_SECTIONS \ 831 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$" 832 #define ALL_EXIT_TEXT_SECTIONS \ 833 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$" 834 835 #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \ 836 MEM_INIT_SECTIONS 837 #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \ 838 MEM_EXIT_SECTIONS 839 840 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 841 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS 842 843 #define DATA_SECTIONS ".data$", ".data.rel$" 844 #define TEXT_SECTIONS ".text$" 845 846 #define INIT_SECTIONS ".init.*" 847 #define DEV_INIT_SECTIONS ".devinit.*" 848 #define CPU_INIT_SECTIONS ".cpuinit.*" 849 #define MEM_INIT_SECTIONS ".meminit.*" 850 851 #define EXIT_SECTIONS ".exit.*" 852 #define DEV_EXIT_SECTIONS ".devexit.*" 853 #define CPU_EXIT_SECTIONS ".cpuexit.*" 854 #define MEM_EXIT_SECTIONS ".memexit.*" 855 856 /* init data sections */ 857 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL }; 858 859 /* all init sections */ 860 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL }; 861 862 /* All init and exit sections (code + data) */ 863 static const char *init_exit_sections[] = 864 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }; 865 866 /* data section */ 867 static const char *data_sections[] = { DATA_SECTIONS, NULL }; 868 869 870 /* symbols in .data that may refer to init/exit sections */ 871 #define DEFAULT_SYMBOL_WHITE_LIST \ 872 "*driver", \ 873 "*_template", /* scsi uses *_template a lot */ \ 874 "*_timer", /* arm uses ops structures named _timer a lot */ \ 875 "*_sht", /* scsi also used *_sht to some extent */ \ 876 "*_ops", \ 877 "*_probe", \ 878 "*_probe_one", \ 879 "*_console" 880 881 static const char *head_sections[] = { ".head.text*", NULL }; 882 static const char *linker_symbols[] = 883 { "__init_begin", "_sinittext", "_einittext", NULL }; 884 885 enum mismatch { 886 TEXT_TO_ANY_INIT, 887 DATA_TO_ANY_INIT, 888 TEXT_TO_ANY_EXIT, 889 DATA_TO_ANY_EXIT, 890 XXXINIT_TO_SOME_INIT, 891 XXXEXIT_TO_SOME_EXIT, 892 ANY_INIT_TO_ANY_EXIT, 893 ANY_EXIT_TO_ANY_INIT, 894 EXPORT_TO_INIT_EXIT, 895 }; 896 897 struct sectioncheck { 898 const char *fromsec[20]; 899 const char *tosec[20]; 900 enum mismatch mismatch; 901 const char *symbol_white_list[20]; 902 }; 903 904 const struct sectioncheck sectioncheck[] = { 905 /* Do not reference init/exit code/data from 906 * normal code and data 907 */ 908 { 909 .fromsec = { TEXT_SECTIONS, NULL }, 910 .tosec = { ALL_INIT_SECTIONS, NULL }, 911 .mismatch = TEXT_TO_ANY_INIT, 912 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 913 }, 914 { 915 .fromsec = { DATA_SECTIONS, NULL }, 916 .tosec = { ALL_XXXINIT_SECTIONS, NULL }, 917 .mismatch = DATA_TO_ANY_INIT, 918 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 919 }, 920 { 921 .fromsec = { DATA_SECTIONS, NULL }, 922 .tosec = { INIT_SECTIONS, NULL }, 923 .mismatch = DATA_TO_ANY_INIT, 924 .symbol_white_list = { 925 "*_template", "*_timer", "*_sht", "*_ops", 926 "*_probe", "*_probe_one", "*_console", NULL 927 }, 928 }, 929 { 930 .fromsec = { TEXT_SECTIONS, NULL }, 931 .tosec = { ALL_EXIT_SECTIONS, NULL }, 932 .mismatch = TEXT_TO_ANY_EXIT, 933 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 934 }, 935 { 936 .fromsec = { DATA_SECTIONS, NULL }, 937 .tosec = { ALL_EXIT_SECTIONS, NULL }, 938 .mismatch = DATA_TO_ANY_EXIT, 939 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 940 }, 941 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */ 942 { 943 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 944 .tosec = { INIT_SECTIONS, NULL }, 945 .mismatch = XXXINIT_TO_SOME_INIT, 946 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 947 }, 948 /* Do not reference cpuinit code/data from meminit code/data */ 949 { 950 .fromsec = { MEM_INIT_SECTIONS, NULL }, 951 .tosec = { CPU_INIT_SECTIONS, NULL }, 952 .mismatch = XXXINIT_TO_SOME_INIT, 953 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 954 }, 955 /* Do not reference meminit code/data from cpuinit code/data */ 956 { 957 .fromsec = { CPU_INIT_SECTIONS, NULL }, 958 .tosec = { MEM_INIT_SECTIONS, NULL }, 959 .mismatch = XXXINIT_TO_SOME_INIT, 960 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 961 }, 962 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */ 963 { 964 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL }, 965 .tosec = { EXIT_SECTIONS, NULL }, 966 .mismatch = XXXEXIT_TO_SOME_EXIT, 967 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 968 }, 969 /* Do not reference cpuexit code/data from memexit code/data */ 970 { 971 .fromsec = { MEM_EXIT_SECTIONS, NULL }, 972 .tosec = { CPU_EXIT_SECTIONS, NULL }, 973 .mismatch = XXXEXIT_TO_SOME_EXIT, 974 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 975 }, 976 /* Do not reference memexit code/data from cpuexit code/data */ 977 { 978 .fromsec = { CPU_EXIT_SECTIONS, NULL }, 979 .tosec = { MEM_EXIT_SECTIONS, NULL }, 980 .mismatch = XXXEXIT_TO_SOME_EXIT, 981 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 982 }, 983 /* Do not use exit code/data from init code */ 984 { 985 .fromsec = { ALL_INIT_SECTIONS, NULL }, 986 .tosec = { ALL_EXIT_SECTIONS, NULL }, 987 .mismatch = ANY_INIT_TO_ANY_EXIT, 988 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 989 }, 990 /* Do not use init code/data from exit code */ 991 { 992 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 993 .tosec = { ALL_INIT_SECTIONS, NULL }, 994 .mismatch = ANY_EXIT_TO_ANY_INIT, 995 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 996 }, 997 /* Do not export init/exit functions or data */ 998 { 999 .fromsec = { "__ksymtab*", NULL }, 1000 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL }, 1001 .mismatch = EXPORT_TO_INIT_EXIT, 1002 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1003 } 1004 }; 1005 1006 static const struct sectioncheck *section_mismatch( 1007 const char *fromsec, const char *tosec) 1008 { 1009 int i; 1010 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck); 1011 const struct sectioncheck *check = §ioncheck[0]; 1012 1013 for (i = 0; i < elems; i++) { 1014 if (match(fromsec, check->fromsec) && 1015 match(tosec, check->tosec)) 1016 return check; 1017 check++; 1018 } 1019 return NULL; 1020 } 1021 1022 /** 1023 * Whitelist to allow certain references to pass with no warning. 1024 * 1025 * Pattern 1: 1026 * If a module parameter is declared __initdata and permissions=0 1027 * then this is legal despite the warning generated. 1028 * We cannot see value of permissions here, so just ignore 1029 * this pattern. 1030 * The pattern is identified by: 1031 * tosec = .init.data 1032 * fromsec = .data* 1033 * atsym =__param* 1034 * 1035 * Pattern 1a: 1036 * module_param_call() ops can refer to __init set function if permissions=0 1037 * The pattern is identified by: 1038 * tosec = .init.text 1039 * fromsec = .data* 1040 * atsym = __param_ops_* 1041 * 1042 * Pattern 2: 1043 * Many drivers utilise a *driver container with references to 1044 * add, remove, probe functions etc. 1045 * These functions may often be marked __devinit and we do not want to 1046 * warn here. 1047 * the pattern is identified by: 1048 * tosec = init or exit section 1049 * fromsec = data section 1050 * atsym = *driver, *_template, *_sht, *_ops, *_probe, 1051 * *probe_one, *_console, *_timer 1052 * 1053 * Pattern 3: 1054 * Whitelist all references from .head.text to any init section 1055 * 1056 * Pattern 4: 1057 * Some symbols belong to init section but still it is ok to reference 1058 * these from non-init sections as these symbols don't have any memory 1059 * allocated for them and symbol address and value are same. So even 1060 * if init section is freed, its ok to reference those symbols. 1061 * For ex. symbols marking the init section boundaries. 1062 * This pattern is identified by 1063 * refsymname = __init_begin, _sinittext, _einittext 1064 * 1065 **/ 1066 static int secref_whitelist(const struct sectioncheck *mismatch, 1067 const char *fromsec, const char *fromsym, 1068 const char *tosec, const char *tosym) 1069 { 1070 /* Check for pattern 1 */ 1071 if (match(tosec, init_data_sections) && 1072 match(fromsec, data_sections) && 1073 (strncmp(fromsym, "__param", strlen("__param")) == 0)) 1074 return 0; 1075 1076 /* Check for pattern 1a */ 1077 if (strcmp(tosec, ".init.text") == 0 && 1078 match(fromsec, data_sections) && 1079 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0)) 1080 return 0; 1081 1082 /* Check for pattern 2 */ 1083 if (match(tosec, init_exit_sections) && 1084 match(fromsec, data_sections) && 1085 match(fromsym, mismatch->symbol_white_list)) 1086 return 0; 1087 1088 /* Check for pattern 3 */ 1089 if (match(fromsec, head_sections) && 1090 match(tosec, init_sections)) 1091 return 0; 1092 1093 /* Check for pattern 4 */ 1094 if (match(tosym, linker_symbols)) 1095 return 0; 1096 1097 return 1; 1098 } 1099 1100 /** 1101 * Find symbol based on relocation record info. 1102 * In some cases the symbol supplied is a valid symbol so 1103 * return refsym. If st_name != 0 we assume this is a valid symbol. 1104 * In other cases the symbol needs to be looked up in the symbol table 1105 * based on section and address. 1106 * **/ 1107 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr, 1108 Elf_Sym *relsym) 1109 { 1110 Elf_Sym *sym; 1111 Elf_Sym *near = NULL; 1112 Elf64_Sword distance = 20; 1113 Elf64_Sword d; 1114 unsigned int relsym_secindex; 1115 1116 if (relsym->st_name != 0) 1117 return relsym; 1118 1119 relsym_secindex = get_secindex(elf, relsym); 1120 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1121 if (get_secindex(elf, sym) != relsym_secindex) 1122 continue; 1123 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) 1124 continue; 1125 if (sym->st_value == addr) 1126 return sym; 1127 /* Find a symbol nearby - addr are maybe negative */ 1128 d = sym->st_value - addr; 1129 if (d < 0) 1130 d = addr - sym->st_value; 1131 if (d < distance) { 1132 distance = d; 1133 near = sym; 1134 } 1135 } 1136 /* We need a close match */ 1137 if (distance < 20) 1138 return near; 1139 else 1140 return NULL; 1141 } 1142 1143 static inline int is_arm_mapping_symbol(const char *str) 1144 { 1145 return str[0] == '$' && strchr("atd", str[1]) 1146 && (str[2] == '\0' || str[2] == '.'); 1147 } 1148 1149 /* 1150 * If there's no name there, ignore it; likewise, ignore it if it's 1151 * one of the magic symbols emitted used by current ARM tools. 1152 * 1153 * Otherwise if find_symbols_between() returns those symbols, they'll 1154 * fail the whitelist tests and cause lots of false alarms ... fixable 1155 * only by merging __exit and __init sections into __text, bloating 1156 * the kernel (which is especially evil on embedded platforms). 1157 */ 1158 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 1159 { 1160 const char *name = elf->strtab + sym->st_name; 1161 1162 if (!name || !strlen(name)) 1163 return 0; 1164 return !is_arm_mapping_symbol(name); 1165 } 1166 1167 /* 1168 * Find symbols before or equal addr and after addr - in the section sec. 1169 * If we find two symbols with equal offset prefer one with a valid name. 1170 * The ELF format may have a better way to detect what type of symbol 1171 * it is, but this works for now. 1172 **/ 1173 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr, 1174 const char *sec) 1175 { 1176 Elf_Sym *sym; 1177 Elf_Sym *near = NULL; 1178 Elf_Addr distance = ~0; 1179 1180 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1181 const char *symsec; 1182 1183 if (is_shndx_special(sym->st_shndx)) 1184 continue; 1185 symsec = sec_name(elf, get_secindex(elf, sym)); 1186 if (strcmp(symsec, sec) != 0) 1187 continue; 1188 if (!is_valid_name(elf, sym)) 1189 continue; 1190 if (sym->st_value <= addr) { 1191 if ((addr - sym->st_value) < distance) { 1192 distance = addr - sym->st_value; 1193 near = sym; 1194 } else if ((addr - sym->st_value) == distance) { 1195 near = sym; 1196 } 1197 } 1198 } 1199 return near; 1200 } 1201 1202 /* 1203 * Convert a section name to the function/data attribute 1204 * .init.text => __init 1205 * .cpuinit.data => __cpudata 1206 * .memexitconst => __memconst 1207 * etc. 1208 * 1209 * The memory of returned value has been allocated on a heap. The user of this 1210 * method should free it after usage. 1211 */ 1212 static char *sec2annotation(const char *s) 1213 { 1214 if (match(s, init_exit_sections)) { 1215 char *p = malloc(20); 1216 char *r = p; 1217 1218 *p++ = '_'; 1219 *p++ = '_'; 1220 if (*s == '.') 1221 s++; 1222 while (*s && *s != '.') 1223 *p++ = *s++; 1224 *p = '\0'; 1225 if (*s == '.') 1226 s++; 1227 if (strstr(s, "rodata") != NULL) 1228 strcat(p, "const "); 1229 else if (strstr(s, "data") != NULL) 1230 strcat(p, "data "); 1231 else 1232 strcat(p, " "); 1233 return r; 1234 } else { 1235 return strdup(""); 1236 } 1237 } 1238 1239 static int is_function(Elf_Sym *sym) 1240 { 1241 if (sym) 1242 return ELF_ST_TYPE(sym->st_info) == STT_FUNC; 1243 else 1244 return -1; 1245 } 1246 1247 static void print_section_list(const char * const list[20]) 1248 { 1249 const char *const *s = list; 1250 1251 while (*s) { 1252 fprintf(stderr, "%s", *s); 1253 s++; 1254 if (*s) 1255 fprintf(stderr, ", "); 1256 } 1257 fprintf(stderr, "\n"); 1258 } 1259 1260 /* 1261 * Print a warning about a section mismatch. 1262 * Try to find symbols near it so user can find it. 1263 * Check whitelist before warning - it may be a false positive. 1264 */ 1265 static void report_sec_mismatch(const char *modname, 1266 const struct sectioncheck *mismatch, 1267 const char *fromsec, 1268 unsigned long long fromaddr, 1269 const char *fromsym, 1270 int from_is_func, 1271 const char *tosec, const char *tosym, 1272 int to_is_func) 1273 { 1274 const char *from, *from_p; 1275 const char *to, *to_p; 1276 char *prl_from; 1277 char *prl_to; 1278 1279 switch (from_is_func) { 1280 case 0: from = "variable"; from_p = ""; break; 1281 case 1: from = "function"; from_p = "()"; break; 1282 default: from = "(unknown reference)"; from_p = ""; break; 1283 } 1284 switch (to_is_func) { 1285 case 0: to = "variable"; to_p = ""; break; 1286 case 1: to = "function"; to_p = "()"; break; 1287 default: to = "(unknown reference)"; to_p = ""; break; 1288 } 1289 1290 sec_mismatch_count++; 1291 if (!sec_mismatch_verbose) 1292 return; 1293 1294 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s " 1295 "to the %s %s:%s%s\n", 1296 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec, 1297 tosym, to_p); 1298 1299 switch (mismatch->mismatch) { 1300 case TEXT_TO_ANY_INIT: 1301 prl_from = sec2annotation(fromsec); 1302 prl_to = sec2annotation(tosec); 1303 fprintf(stderr, 1304 "The function %s%s() references\n" 1305 "the %s %s%s%s.\n" 1306 "This is often because %s lacks a %s\n" 1307 "annotation or the annotation of %s is wrong.\n", 1308 prl_from, fromsym, 1309 to, prl_to, tosym, to_p, 1310 fromsym, prl_to, tosym); 1311 free(prl_from); 1312 free(prl_to); 1313 break; 1314 case DATA_TO_ANY_INIT: { 1315 prl_to = sec2annotation(tosec); 1316 fprintf(stderr, 1317 "The variable %s references\n" 1318 "the %s %s%s%s\n" 1319 "If the reference is valid then annotate the\n" 1320 "variable with __init* or __refdata (see linux/init.h) " 1321 "or name the variable:\n", 1322 fromsym, to, prl_to, tosym, to_p); 1323 print_section_list(mismatch->symbol_white_list); 1324 free(prl_to); 1325 break; 1326 } 1327 case TEXT_TO_ANY_EXIT: 1328 prl_to = sec2annotation(tosec); 1329 fprintf(stderr, 1330 "The function %s() references a %s in an exit section.\n" 1331 "Often the %s %s%s has valid usage outside the exit section\n" 1332 "and the fix is to remove the %sannotation of %s.\n", 1333 fromsym, to, to, tosym, to_p, prl_to, tosym); 1334 free(prl_to); 1335 break; 1336 case DATA_TO_ANY_EXIT: { 1337 prl_to = sec2annotation(tosec); 1338 fprintf(stderr, 1339 "The variable %s references\n" 1340 "the %s %s%s%s\n" 1341 "If the reference is valid then annotate the\n" 1342 "variable with __exit* (see linux/init.h) or " 1343 "name the variable:\n", 1344 fromsym, to, prl_to, tosym, to_p); 1345 print_section_list(mismatch->symbol_white_list); 1346 free(prl_to); 1347 break; 1348 } 1349 case XXXINIT_TO_SOME_INIT: 1350 case XXXEXIT_TO_SOME_EXIT: 1351 prl_from = sec2annotation(fromsec); 1352 prl_to = sec2annotation(tosec); 1353 fprintf(stderr, 1354 "The %s %s%s%s references\n" 1355 "a %s %s%s%s.\n" 1356 "If %s is only used by %s then\n" 1357 "annotate %s with a matching annotation.\n", 1358 from, prl_from, fromsym, from_p, 1359 to, prl_to, tosym, to_p, 1360 tosym, fromsym, tosym); 1361 free(prl_from); 1362 free(prl_to); 1363 break; 1364 case ANY_INIT_TO_ANY_EXIT: 1365 prl_from = sec2annotation(fromsec); 1366 prl_to = sec2annotation(tosec); 1367 fprintf(stderr, 1368 "The %s %s%s%s references\n" 1369 "a %s %s%s%s.\n" 1370 "This is often seen when error handling " 1371 "in the init function\n" 1372 "uses functionality in the exit path.\n" 1373 "The fix is often to remove the %sannotation of\n" 1374 "%s%s so it may be used outside an exit section.\n", 1375 from, prl_from, fromsym, from_p, 1376 to, prl_to, tosym, to_p, 1377 prl_to, tosym, to_p); 1378 free(prl_from); 1379 free(prl_to); 1380 break; 1381 case ANY_EXIT_TO_ANY_INIT: 1382 prl_from = sec2annotation(fromsec); 1383 prl_to = sec2annotation(tosec); 1384 fprintf(stderr, 1385 "The %s %s%s%s references\n" 1386 "a %s %s%s%s.\n" 1387 "This is often seen when error handling " 1388 "in the exit function\n" 1389 "uses functionality in the init path.\n" 1390 "The fix is often to remove the %sannotation of\n" 1391 "%s%s so it may be used outside an init section.\n", 1392 from, prl_from, fromsym, from_p, 1393 to, prl_to, tosym, to_p, 1394 prl_to, tosym, to_p); 1395 free(prl_from); 1396 free(prl_to); 1397 break; 1398 case EXPORT_TO_INIT_EXIT: 1399 prl_to = sec2annotation(tosec); 1400 fprintf(stderr, 1401 "The symbol %s is exported and annotated %s\n" 1402 "Fix this by removing the %sannotation of %s " 1403 "or drop the export.\n", 1404 tosym, prl_to, prl_to, tosym); 1405 free(prl_to); 1406 break; 1407 } 1408 fprintf(stderr, "\n"); 1409 } 1410 1411 static void check_section_mismatch(const char *modname, struct elf_info *elf, 1412 Elf_Rela *r, Elf_Sym *sym, const char *fromsec) 1413 { 1414 const char *tosec; 1415 const struct sectioncheck *mismatch; 1416 1417 tosec = sec_name(elf, get_secindex(elf, sym)); 1418 mismatch = section_mismatch(fromsec, tosec); 1419 if (mismatch) { 1420 Elf_Sym *to; 1421 Elf_Sym *from; 1422 const char *tosym; 1423 const char *fromsym; 1424 1425 from = find_elf_symbol2(elf, r->r_offset, fromsec); 1426 fromsym = sym_name(elf, from); 1427 to = find_elf_symbol(elf, r->r_addend, sym); 1428 tosym = sym_name(elf, to); 1429 1430 /* check whitelist - we may ignore it */ 1431 if (secref_whitelist(mismatch, 1432 fromsec, fromsym, tosec, tosym)) { 1433 report_sec_mismatch(modname, mismatch, 1434 fromsec, r->r_offset, fromsym, 1435 is_function(from), tosec, tosym, 1436 is_function(to)); 1437 } 1438 } 1439 } 1440 1441 static unsigned int *reloc_location(struct elf_info *elf, 1442 Elf_Shdr *sechdr, Elf_Rela *r) 1443 { 1444 Elf_Shdr *sechdrs = elf->sechdrs; 1445 int section = sechdr->sh_info; 1446 1447 return (void *)elf->hdr + sechdrs[section].sh_offset + 1448 r->r_offset; 1449 } 1450 1451 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1452 { 1453 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1454 unsigned int *location = reloc_location(elf, sechdr, r); 1455 1456 switch (r_typ) { 1457 case R_386_32: 1458 r->r_addend = TO_NATIVE(*location); 1459 break; 1460 case R_386_PC32: 1461 r->r_addend = TO_NATIVE(*location) + 4; 1462 /* For CONFIG_RELOCATABLE=y */ 1463 if (elf->hdr->e_type == ET_EXEC) 1464 r->r_addend += r->r_offset; 1465 break; 1466 } 1467 return 0; 1468 } 1469 1470 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1471 { 1472 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1473 1474 switch (r_typ) { 1475 case R_ARM_ABS32: 1476 /* From ARM ABI: (S + A) | T */ 1477 r->r_addend = (int)(long) 1478 (elf->symtab_start + ELF_R_SYM(r->r_info)); 1479 break; 1480 case R_ARM_PC24: 1481 /* From ARM ABI: ((S + A) | T) - P */ 1482 r->r_addend = (int)(long)(elf->hdr + 1483 sechdr->sh_offset + 1484 (r->r_offset - sechdr->sh_addr)); 1485 break; 1486 default: 1487 return 1; 1488 } 1489 return 0; 1490 } 1491 1492 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1493 { 1494 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1495 unsigned int *location = reloc_location(elf, sechdr, r); 1496 unsigned int inst; 1497 1498 if (r_typ == R_MIPS_HI16) 1499 return 1; /* skip this */ 1500 inst = TO_NATIVE(*location); 1501 switch (r_typ) { 1502 case R_MIPS_LO16: 1503 r->r_addend = inst & 0xffff; 1504 break; 1505 case R_MIPS_26: 1506 r->r_addend = (inst & 0x03ffffff) << 2; 1507 break; 1508 case R_MIPS_32: 1509 r->r_addend = inst; 1510 break; 1511 } 1512 return 0; 1513 } 1514 1515 static void section_rela(const char *modname, struct elf_info *elf, 1516 Elf_Shdr *sechdr) 1517 { 1518 Elf_Sym *sym; 1519 Elf_Rela *rela; 1520 Elf_Rela r; 1521 unsigned int r_sym; 1522 const char *fromsec; 1523 1524 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; 1525 Elf_Rela *stop = (void *)start + sechdr->sh_size; 1526 1527 fromsec = sech_name(elf, sechdr); 1528 fromsec += strlen(".rela"); 1529 /* if from section (name) is know good then skip it */ 1530 if (match(fromsec, section_white_list)) 1531 return; 1532 1533 for (rela = start; rela < stop; rela++) { 1534 r.r_offset = TO_NATIVE(rela->r_offset); 1535 #if KERNEL_ELFCLASS == ELFCLASS64 1536 if (elf->hdr->e_machine == EM_MIPS) { 1537 unsigned int r_typ; 1538 r_sym = ELF64_MIPS_R_SYM(rela->r_info); 1539 r_sym = TO_NATIVE(r_sym); 1540 r_typ = ELF64_MIPS_R_TYPE(rela->r_info); 1541 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1542 } else { 1543 r.r_info = TO_NATIVE(rela->r_info); 1544 r_sym = ELF_R_SYM(r.r_info); 1545 } 1546 #else 1547 r.r_info = TO_NATIVE(rela->r_info); 1548 r_sym = ELF_R_SYM(r.r_info); 1549 #endif 1550 r.r_addend = TO_NATIVE(rela->r_addend); 1551 sym = elf->symtab_start + r_sym; 1552 /* Skip special sections */ 1553 if (is_shndx_special(sym->st_shndx)) 1554 continue; 1555 check_section_mismatch(modname, elf, &r, sym, fromsec); 1556 } 1557 } 1558 1559 static void section_rel(const char *modname, struct elf_info *elf, 1560 Elf_Shdr *sechdr) 1561 { 1562 Elf_Sym *sym; 1563 Elf_Rel *rel; 1564 Elf_Rela r; 1565 unsigned int r_sym; 1566 const char *fromsec; 1567 1568 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset; 1569 Elf_Rel *stop = (void *)start + sechdr->sh_size; 1570 1571 fromsec = sech_name(elf, sechdr); 1572 fromsec += strlen(".rel"); 1573 /* if from section (name) is know good then skip it */ 1574 if (match(fromsec, section_white_list)) 1575 return; 1576 1577 for (rel = start; rel < stop; rel++) { 1578 r.r_offset = TO_NATIVE(rel->r_offset); 1579 #if KERNEL_ELFCLASS == ELFCLASS64 1580 if (elf->hdr->e_machine == EM_MIPS) { 1581 unsigned int r_typ; 1582 r_sym = ELF64_MIPS_R_SYM(rel->r_info); 1583 r_sym = TO_NATIVE(r_sym); 1584 r_typ = ELF64_MIPS_R_TYPE(rel->r_info); 1585 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1586 } else { 1587 r.r_info = TO_NATIVE(rel->r_info); 1588 r_sym = ELF_R_SYM(r.r_info); 1589 } 1590 #else 1591 r.r_info = TO_NATIVE(rel->r_info); 1592 r_sym = ELF_R_SYM(r.r_info); 1593 #endif 1594 r.r_addend = 0; 1595 switch (elf->hdr->e_machine) { 1596 case EM_386: 1597 if (addend_386_rel(elf, sechdr, &r)) 1598 continue; 1599 break; 1600 case EM_ARM: 1601 if (addend_arm_rel(elf, sechdr, &r)) 1602 continue; 1603 break; 1604 case EM_MIPS: 1605 if (addend_mips_rel(elf, sechdr, &r)) 1606 continue; 1607 break; 1608 } 1609 sym = elf->symtab_start + r_sym; 1610 /* Skip special sections */ 1611 if (is_shndx_special(sym->st_shndx)) 1612 continue; 1613 check_section_mismatch(modname, elf, &r, sym, fromsec); 1614 } 1615 } 1616 1617 /** 1618 * A module includes a number of sections that are discarded 1619 * either when loaded or when used as built-in. 1620 * For loaded modules all functions marked __init and all data 1621 * marked __initdata will be discarded when the module has been initialized. 1622 * Likewise for modules used built-in the sections marked __exit 1623 * are discarded because __exit marked function are supposed to be called 1624 * only when a module is unloaded which never happens for built-in modules. 1625 * The check_sec_ref() function traverses all relocation records 1626 * to find all references to a section that reference a section that will 1627 * be discarded and warns about it. 1628 **/ 1629 static void check_sec_ref(struct module *mod, const char *modname, 1630 struct elf_info *elf) 1631 { 1632 int i; 1633 Elf_Shdr *sechdrs = elf->sechdrs; 1634 1635 /* Walk through all sections */ 1636 for (i = 0; i < elf->num_sections; i++) { 1637 check_section(modname, elf, &elf->sechdrs[i]); 1638 /* We want to process only relocation sections and not .init */ 1639 if (sechdrs[i].sh_type == SHT_RELA) 1640 section_rela(modname, elf, &elf->sechdrs[i]); 1641 else if (sechdrs[i].sh_type == SHT_REL) 1642 section_rel(modname, elf, &elf->sechdrs[i]); 1643 } 1644 } 1645 1646 static void read_symbols(char *modname) 1647 { 1648 const char *symname; 1649 char *version; 1650 char *license; 1651 struct module *mod; 1652 struct elf_info info = { }; 1653 Elf_Sym *sym; 1654 1655 if (!parse_elf(&info, modname)) 1656 return; 1657 1658 mod = new_module(modname); 1659 1660 /* When there's no vmlinux, don't print warnings about 1661 * unresolved symbols (since there'll be too many ;) */ 1662 if (is_vmlinux(modname)) { 1663 have_vmlinux = 1; 1664 mod->skip = 1; 1665 } 1666 1667 license = get_modinfo(info.modinfo, info.modinfo_len, "license"); 1668 if (info.modinfo && !license && !is_vmlinux(modname)) 1669 warn("modpost: missing MODULE_LICENSE() in %s\n" 1670 "see include/linux/module.h for " 1671 "more information\n", modname); 1672 while (license) { 1673 if (license_is_gpl_compatible(license)) 1674 mod->gpl_compatible = 1; 1675 else { 1676 mod->gpl_compatible = 0; 1677 break; 1678 } 1679 license = get_next_modinfo(info.modinfo, info.modinfo_len, 1680 "license", license); 1681 } 1682 1683 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1684 symname = info.strtab + sym->st_name; 1685 1686 handle_modversions(mod, &info, sym, symname); 1687 handle_moddevtable(mod, &info, sym, symname); 1688 } 1689 if (!is_vmlinux(modname) || 1690 (is_vmlinux(modname) && vmlinux_section_warnings)) 1691 check_sec_ref(mod, modname, &info); 1692 1693 version = get_modinfo(info.modinfo, info.modinfo_len, "version"); 1694 if (version) 1695 maybe_frob_rcs_version(modname, version, info.modinfo, 1696 version - (char *)info.hdr); 1697 if (version || (all_versions && !is_vmlinux(modname))) 1698 get_src_version(modname, mod->srcversion, 1699 sizeof(mod->srcversion)-1); 1700 1701 parse_elf_finish(&info); 1702 1703 /* Our trick to get versioning for module struct etc. - it's 1704 * never passed as an argument to an exported function, so 1705 * the automatic versioning doesn't pick it up, but it's really 1706 * important anyhow */ 1707 if (modversions) 1708 mod->unres = alloc_symbol("module_layout", 0, mod->unres); 1709 } 1710 1711 #define SZ 500 1712 1713 /* We first write the generated file into memory using the 1714 * following helper, then compare to the file on disk and 1715 * only update the later if anything changed */ 1716 1717 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1718 const char *fmt, ...) 1719 { 1720 char tmp[SZ]; 1721 int len; 1722 va_list ap; 1723 1724 va_start(ap, fmt); 1725 len = vsnprintf(tmp, SZ, fmt, ap); 1726 buf_write(buf, tmp, len); 1727 va_end(ap); 1728 } 1729 1730 void buf_write(struct buffer *buf, const char *s, int len) 1731 { 1732 if (buf->size - buf->pos < len) { 1733 buf->size += len + SZ; 1734 buf->p = realloc(buf->p, buf->size); 1735 } 1736 strncpy(buf->p + buf->pos, s, len); 1737 buf->pos += len; 1738 } 1739 1740 static void check_for_gpl_usage(enum export exp, const char *m, const char *s) 1741 { 1742 const char *e = is_vmlinux(m) ?"":".ko"; 1743 1744 switch (exp) { 1745 case export_gpl: 1746 fatal("modpost: GPL-incompatible module %s%s " 1747 "uses GPL-only symbol '%s'\n", m, e, s); 1748 break; 1749 case export_unused_gpl: 1750 fatal("modpost: GPL-incompatible module %s%s " 1751 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); 1752 break; 1753 case export_gpl_future: 1754 warn("modpost: GPL-incompatible module %s%s " 1755 "uses future GPL-only symbol '%s'\n", m, e, s); 1756 break; 1757 case export_plain: 1758 case export_unused: 1759 case export_unknown: 1760 /* ignore */ 1761 break; 1762 } 1763 } 1764 1765 static void check_for_unused(enum export exp, const char *m, const char *s) 1766 { 1767 const char *e = is_vmlinux(m) ?"":".ko"; 1768 1769 switch (exp) { 1770 case export_unused: 1771 case export_unused_gpl: 1772 warn("modpost: module %s%s " 1773 "uses symbol '%s' marked UNUSED\n", m, e, s); 1774 break; 1775 default: 1776 /* ignore */ 1777 break; 1778 } 1779 } 1780 1781 static void check_exports(struct module *mod) 1782 { 1783 struct symbol *s, *exp; 1784 1785 for (s = mod->unres; s; s = s->next) { 1786 const char *basename; 1787 exp = find_symbol(s->name); 1788 if (!exp || exp->module == mod) 1789 continue; 1790 basename = strrchr(mod->name, '/'); 1791 if (basename) 1792 basename++; 1793 else 1794 basename = mod->name; 1795 if (!mod->gpl_compatible) 1796 check_for_gpl_usage(exp->export, basename, exp->name); 1797 check_for_unused(exp->export, basename, exp->name); 1798 } 1799 } 1800 1801 /** 1802 * Header for the generated file 1803 **/ 1804 static void add_header(struct buffer *b, struct module *mod) 1805 { 1806 buf_printf(b, "#include <linux/module.h>\n"); 1807 buf_printf(b, "#include <linux/vermagic.h>\n"); 1808 buf_printf(b, "#include <linux/compiler.h>\n"); 1809 buf_printf(b, "\n"); 1810 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1811 buf_printf(b, "\n"); 1812 buf_printf(b, "struct module __this_module\n"); 1813 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); 1814 buf_printf(b, " .name = KBUILD_MODNAME,\n"); 1815 if (mod->has_init) 1816 buf_printf(b, " .init = init_module,\n"); 1817 if (mod->has_cleanup) 1818 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1819 " .exit = cleanup_module,\n" 1820 "#endif\n"); 1821 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n"); 1822 buf_printf(b, "};\n"); 1823 } 1824 1825 static void add_staging_flag(struct buffer *b, const char *name) 1826 { 1827 static const char *staging_dir = "drivers/staging"; 1828 1829 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0) 1830 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1831 } 1832 1833 /** 1834 * Record CRCs for unresolved symbols 1835 **/ 1836 static int add_versions(struct buffer *b, struct module *mod) 1837 { 1838 struct symbol *s, *exp; 1839 int err = 0; 1840 1841 for (s = mod->unres; s; s = s->next) { 1842 exp = find_symbol(s->name); 1843 if (!exp || exp->module == mod) { 1844 if (have_vmlinux && !s->weak) { 1845 if (warn_unresolved) { 1846 warn("\"%s\" [%s.ko] undefined!\n", 1847 s->name, mod->name); 1848 } else { 1849 merror("\"%s\" [%s.ko] undefined!\n", 1850 s->name, mod->name); 1851 err = 1; 1852 } 1853 } 1854 continue; 1855 } 1856 s->module = exp->module; 1857 s->crc_valid = exp->crc_valid; 1858 s->crc = exp->crc; 1859 } 1860 1861 if (!modversions) 1862 return err; 1863 1864 buf_printf(b, "\n"); 1865 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1866 buf_printf(b, "__used\n"); 1867 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); 1868 1869 for (s = mod->unres; s; s = s->next) { 1870 if (!s->module) 1871 continue; 1872 if (!s->crc_valid) { 1873 warn("\"%s\" [%s.ko] has no CRC!\n", 1874 s->name, mod->name); 1875 continue; 1876 } 1877 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); 1878 } 1879 1880 buf_printf(b, "};\n"); 1881 1882 return err; 1883 } 1884 1885 static void add_depends(struct buffer *b, struct module *mod, 1886 struct module *modules) 1887 { 1888 struct symbol *s; 1889 struct module *m; 1890 int first = 1; 1891 1892 for (m = modules; m; m = m->next) 1893 m->seen = is_vmlinux(m->name); 1894 1895 buf_printf(b, "\n"); 1896 buf_printf(b, "static const char __module_depends[]\n"); 1897 buf_printf(b, "__used\n"); 1898 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); 1899 buf_printf(b, "\"depends="); 1900 for (s = mod->unres; s; s = s->next) { 1901 const char *p; 1902 if (!s->module) 1903 continue; 1904 1905 if (s->module->seen) 1906 continue; 1907 1908 s->module->seen = 1; 1909 p = strrchr(s->module->name, '/'); 1910 if (p) 1911 p++; 1912 else 1913 p = s->module->name; 1914 buf_printf(b, "%s%s", first ? "" : ",", p); 1915 first = 0; 1916 } 1917 buf_printf(b, "\";\n"); 1918 } 1919 1920 static void add_srcversion(struct buffer *b, struct module *mod) 1921 { 1922 if (mod->srcversion[0]) { 1923 buf_printf(b, "\n"); 1924 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1925 mod->srcversion); 1926 } 1927 } 1928 1929 static void write_if_changed(struct buffer *b, const char *fname) 1930 { 1931 char *tmp; 1932 FILE *file; 1933 struct stat st; 1934 1935 file = fopen(fname, "r"); 1936 if (!file) 1937 goto write; 1938 1939 if (fstat(fileno(file), &st) < 0) 1940 goto close_write; 1941 1942 if (st.st_size != b->pos) 1943 goto close_write; 1944 1945 tmp = NOFAIL(malloc(b->pos)); 1946 if (fread(tmp, 1, b->pos, file) != b->pos) 1947 goto free_write; 1948 1949 if (memcmp(tmp, b->p, b->pos) != 0) 1950 goto free_write; 1951 1952 free(tmp); 1953 fclose(file); 1954 return; 1955 1956 free_write: 1957 free(tmp); 1958 close_write: 1959 fclose(file); 1960 write: 1961 file = fopen(fname, "w"); 1962 if (!file) { 1963 perror(fname); 1964 exit(1); 1965 } 1966 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1967 perror(fname); 1968 exit(1); 1969 } 1970 fclose(file); 1971 } 1972 1973 /* parse Module.symvers file. line format: 1974 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] 1975 **/ 1976 static void read_dump(const char *fname, unsigned int kernel) 1977 { 1978 unsigned long size, pos = 0; 1979 void *file = grab_file(fname, &size); 1980 char *line; 1981 1982 if (!file) 1983 /* No symbol versions, silently ignore */ 1984 return; 1985 1986 while ((line = get_next_line(&pos, file, size))) { 1987 char *symname, *modname, *d, *export, *end; 1988 unsigned int crc; 1989 struct module *mod; 1990 struct symbol *s; 1991 1992 if (!(symname = strchr(line, '\t'))) 1993 goto fail; 1994 *symname++ = '\0'; 1995 if (!(modname = strchr(symname, '\t'))) 1996 goto fail; 1997 *modname++ = '\0'; 1998 if ((export = strchr(modname, '\t')) != NULL) 1999 *export++ = '\0'; 2000 if (export && ((end = strchr(export, '\t')) != NULL)) 2001 *end = '\0'; 2002 crc = strtoul(line, &d, 16); 2003 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2004 goto fail; 2005 mod = find_module(modname); 2006 if (!mod) { 2007 if (is_vmlinux(modname)) 2008 have_vmlinux = 1; 2009 mod = new_module(modname); 2010 mod->skip = 1; 2011 } 2012 s = sym_add_exported(symname, mod, export_no(export)); 2013 s->kernel = kernel; 2014 s->preloaded = 1; 2015 sym_update_crc(symname, mod, crc, export_no(export)); 2016 } 2017 return; 2018 fail: 2019 fatal("parse error in symbol dump file\n"); 2020 } 2021 2022 /* For normal builds always dump all symbols. 2023 * For external modules only dump symbols 2024 * that are not read from kernel Module.symvers. 2025 **/ 2026 static int dump_sym(struct symbol *sym) 2027 { 2028 if (!external_module) 2029 return 1; 2030 if (sym->vmlinux || sym->kernel) 2031 return 0; 2032 return 1; 2033 } 2034 2035 static void write_dump(const char *fname) 2036 { 2037 struct buffer buf = { }; 2038 struct symbol *symbol; 2039 int n; 2040 2041 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { 2042 symbol = symbolhash[n]; 2043 while (symbol) { 2044 if (dump_sym(symbol)) 2045 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", 2046 symbol->crc, symbol->name, 2047 symbol->module->name, 2048 export_str(symbol->export)); 2049 symbol = symbol->next; 2050 } 2051 } 2052 write_if_changed(&buf, fname); 2053 } 2054 2055 struct ext_sym_list { 2056 struct ext_sym_list *next; 2057 const char *file; 2058 }; 2059 2060 int main(int argc, char **argv) 2061 { 2062 struct module *mod; 2063 struct buffer buf = { }; 2064 char *kernel_read = NULL, *module_read = NULL; 2065 char *dump_write = NULL; 2066 int opt; 2067 int err; 2068 struct ext_sym_list *extsym_iter; 2069 struct ext_sym_list *extsym_start = NULL; 2070 2071 while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) { 2072 switch (opt) { 2073 case 'i': 2074 kernel_read = optarg; 2075 break; 2076 case 'I': 2077 module_read = optarg; 2078 external_module = 1; 2079 break; 2080 case 'c': 2081 cross_build = 1; 2082 break; 2083 case 'e': 2084 external_module = 1; 2085 extsym_iter = 2086 NOFAIL(malloc(sizeof(*extsym_iter))); 2087 extsym_iter->next = extsym_start; 2088 extsym_iter->file = optarg; 2089 extsym_start = extsym_iter; 2090 break; 2091 case 'm': 2092 modversions = 1; 2093 break; 2094 case 'o': 2095 dump_write = optarg; 2096 break; 2097 case 'a': 2098 all_versions = 1; 2099 break; 2100 case 's': 2101 vmlinux_section_warnings = 0; 2102 break; 2103 case 'S': 2104 sec_mismatch_verbose = 0; 2105 break; 2106 case 'w': 2107 warn_unresolved = 1; 2108 break; 2109 default: 2110 exit(1); 2111 } 2112 } 2113 2114 if (kernel_read) 2115 read_dump(kernel_read, 1); 2116 if (module_read) 2117 read_dump(module_read, 0); 2118 while (extsym_start) { 2119 read_dump(extsym_start->file, 0); 2120 extsym_iter = extsym_start->next; 2121 free(extsym_start); 2122 extsym_start = extsym_iter; 2123 } 2124 2125 while (optind < argc) 2126 read_symbols(argv[optind++]); 2127 2128 for (mod = modules; mod; mod = mod->next) { 2129 if (mod->skip) 2130 continue; 2131 check_exports(mod); 2132 } 2133 2134 err = 0; 2135 2136 for (mod = modules; mod; mod = mod->next) { 2137 char fname[strlen(mod->name) + 10]; 2138 2139 if (mod->skip) 2140 continue; 2141 2142 buf.pos = 0; 2143 2144 add_header(&buf, mod); 2145 add_staging_flag(&buf, mod->name); 2146 err |= add_versions(&buf, mod); 2147 add_depends(&buf, mod, modules); 2148 add_moddevtable(&buf, mod); 2149 add_srcversion(&buf, mod); 2150 2151 sprintf(fname, "%s.mod.c", mod->name); 2152 write_if_changed(&buf, fname); 2153 } 2154 2155 if (dump_write) 2156 write_dump(dump_write); 2157 if (sec_mismatch_count && !sec_mismatch_verbose) 2158 warn("modpost: Found %d section mismatch(es).\n" 2159 "To see full details build your kernel with:\n" 2160 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n", 2161 sec_mismatch_count); 2162 2163 return err; 2164 } 2165