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 const char *sec_name(struct elf_info *elf, int secindex); 258 259 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) 260 261 static enum export export_from_secname(struct elf_info *elf, unsigned int sec) 262 { 263 const char *secname = sec_name(elf, sec); 264 265 if (strstarts(secname, "___ksymtab+")) 266 return export_plain; 267 else if (strstarts(secname, "___ksymtab_unused+")) 268 return export_unused; 269 else if (strstarts(secname, "___ksymtab_gpl+")) 270 return export_gpl; 271 else if (strstarts(secname, "___ksymtab_unused_gpl+")) 272 return export_unused_gpl; 273 else if (strstarts(secname, "___ksymtab_gpl_future+")) 274 return export_gpl_future; 275 else 276 return export_unknown; 277 } 278 279 static enum export export_from_sec(struct elf_info *elf, unsigned int sec) 280 { 281 if (sec == elf->export_sec) 282 return export_plain; 283 else if (sec == elf->export_unused_sec) 284 return export_unused; 285 else if (sec == elf->export_gpl_sec) 286 return export_gpl; 287 else if (sec == elf->export_unused_gpl_sec) 288 return export_unused_gpl; 289 else if (sec == elf->export_gpl_future_sec) 290 return export_gpl_future; 291 else 292 return export_unknown; 293 } 294 295 /** 296 * Add an exported symbol - it may have already been added without a 297 * CRC, in this case just update the CRC 298 **/ 299 static struct symbol *sym_add_exported(const char *name, struct module *mod, 300 enum export export) 301 { 302 struct symbol *s = find_symbol(name); 303 304 if (!s) { 305 s = new_symbol(name, mod, export); 306 } else { 307 if (!s->preloaded) { 308 warn("%s: '%s' exported twice. Previous export " 309 "was in %s%s\n", mod->name, name, 310 s->module->name, 311 is_vmlinux(s->module->name) ?"":".ko"); 312 } else { 313 /* In case Modules.symvers was out of date */ 314 s->module = mod; 315 } 316 } 317 s->preloaded = 0; 318 s->vmlinux = is_vmlinux(mod->name); 319 s->kernel = 0; 320 s->export = export; 321 return s; 322 } 323 324 static void sym_update_crc(const char *name, struct module *mod, 325 unsigned int crc, enum export export) 326 { 327 struct symbol *s = find_symbol(name); 328 329 if (!s) 330 s = new_symbol(name, mod, export); 331 s->crc = crc; 332 s->crc_valid = 1; 333 } 334 335 void *grab_file(const char *filename, unsigned long *size) 336 { 337 struct stat st; 338 void *map; 339 int fd; 340 341 fd = open(filename, O_RDONLY); 342 if (fd < 0 || fstat(fd, &st) != 0) 343 return NULL; 344 345 *size = st.st_size; 346 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 347 close(fd); 348 349 if (map == MAP_FAILED) 350 return NULL; 351 return map; 352 } 353 354 /** 355 * Return a copy of the next line in a mmap'ed file. 356 * spaces in the beginning of the line is trimmed away. 357 * Return a pointer to a static buffer. 358 **/ 359 char *get_next_line(unsigned long *pos, void *file, unsigned long size) 360 { 361 static char line[4096]; 362 int skip = 1; 363 size_t len = 0; 364 signed char *p = (signed char *)file + *pos; 365 char *s = line; 366 367 for (; *pos < size ; (*pos)++) { 368 if (skip && isspace(*p)) { 369 p++; 370 continue; 371 } 372 skip = 0; 373 if (*p != '\n' && (*pos < size)) { 374 len++; 375 *s++ = *p++; 376 if (len > 4095) 377 break; /* Too long, stop */ 378 } else { 379 /* End of string */ 380 *s = '\0'; 381 return line; 382 } 383 } 384 /* End of buffer */ 385 return NULL; 386 } 387 388 void release_file(void *file, unsigned long size) 389 { 390 munmap(file, size); 391 } 392 393 static int parse_elf(struct elf_info *info, const char *filename) 394 { 395 unsigned int i; 396 Elf_Ehdr *hdr; 397 Elf_Shdr *sechdrs; 398 Elf_Sym *sym; 399 const char *secstrings; 400 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 401 402 hdr = grab_file(filename, &info->size); 403 if (!hdr) { 404 perror(filename); 405 exit(1); 406 } 407 info->hdr = hdr; 408 if (info->size < sizeof(*hdr)) { 409 /* file too small, assume this is an empty .o file */ 410 return 0; 411 } 412 /* Is this a valid ELF file? */ 413 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 414 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 415 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 416 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 417 /* Not an ELF file - silently ignore it */ 418 return 0; 419 } 420 /* Fix endianness in ELF header */ 421 hdr->e_type = TO_NATIVE(hdr->e_type); 422 hdr->e_machine = TO_NATIVE(hdr->e_machine); 423 hdr->e_version = TO_NATIVE(hdr->e_version); 424 hdr->e_entry = TO_NATIVE(hdr->e_entry); 425 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 426 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 427 hdr->e_flags = TO_NATIVE(hdr->e_flags); 428 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 429 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 430 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 431 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 432 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 433 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 434 sechdrs = (void *)hdr + hdr->e_shoff; 435 info->sechdrs = sechdrs; 436 437 /* Check if file offset is correct */ 438 if (hdr->e_shoff > info->size) { 439 fatal("section header offset=%lu in file '%s' is bigger than " 440 "filesize=%lu\n", (unsigned long)hdr->e_shoff, 441 filename, info->size); 442 return 0; 443 } 444 445 if (hdr->e_shnum == SHN_UNDEF) { 446 /* 447 * There are more than 64k sections, 448 * read count from .sh_size. 449 */ 450 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 451 } 452 else { 453 info->num_sections = hdr->e_shnum; 454 } 455 if (hdr->e_shstrndx == SHN_XINDEX) { 456 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 457 } 458 else { 459 info->secindex_strings = hdr->e_shstrndx; 460 } 461 462 /* Fix endianness in section headers */ 463 for (i = 0; i < info->num_sections; i++) { 464 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 465 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 466 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 467 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 468 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 469 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 470 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 471 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 472 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 473 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 474 } 475 /* Find symbol table. */ 476 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 477 for (i = 1; i < info->num_sections; i++) { 478 const char *secname; 479 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 480 481 if (!nobits && sechdrs[i].sh_offset > info->size) { 482 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > " 483 "sizeof(*hrd)=%zu\n", filename, 484 (unsigned long)sechdrs[i].sh_offset, 485 sizeof(*hdr)); 486 return 0; 487 } 488 secname = secstrings + sechdrs[i].sh_name; 489 if (strcmp(secname, ".modinfo") == 0) { 490 if (nobits) 491 fatal("%s has NOBITS .modinfo\n", filename); 492 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 493 info->modinfo_len = sechdrs[i].sh_size; 494 } else if (strcmp(secname, "__ksymtab") == 0) 495 info->export_sec = i; 496 else if (strcmp(secname, "__ksymtab_unused") == 0) 497 info->export_unused_sec = i; 498 else if (strcmp(secname, "__ksymtab_gpl") == 0) 499 info->export_gpl_sec = i; 500 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0) 501 info->export_unused_gpl_sec = i; 502 else if (strcmp(secname, "__ksymtab_gpl_future") == 0) 503 info->export_gpl_future_sec = i; 504 505 if (sechdrs[i].sh_type == SHT_SYMTAB) { 506 unsigned int sh_link_idx; 507 symtab_idx = i; 508 info->symtab_start = (void *)hdr + 509 sechdrs[i].sh_offset; 510 info->symtab_stop = (void *)hdr + 511 sechdrs[i].sh_offset + sechdrs[i].sh_size; 512 sh_link_idx = sechdrs[i].sh_link; 513 info->strtab = (void *)hdr + 514 sechdrs[sh_link_idx].sh_offset; 515 } 516 517 /* 32bit section no. table? ("more than 64k sections") */ 518 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 519 symtab_shndx_idx = i; 520 info->symtab_shndx_start = (void *)hdr + 521 sechdrs[i].sh_offset; 522 info->symtab_shndx_stop = (void *)hdr + 523 sechdrs[i].sh_offset + sechdrs[i].sh_size; 524 } 525 } 526 if (!info->symtab_start) 527 fatal("%s has no symtab?\n", filename); 528 529 /* Fix endianness in symbols */ 530 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 531 sym->st_shndx = TO_NATIVE(sym->st_shndx); 532 sym->st_name = TO_NATIVE(sym->st_name); 533 sym->st_value = TO_NATIVE(sym->st_value); 534 sym->st_size = TO_NATIVE(sym->st_size); 535 } 536 537 if (symtab_shndx_idx != ~0U) { 538 Elf32_Word *p; 539 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 540 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 541 filename, sechdrs[symtab_shndx_idx].sh_link, 542 symtab_idx); 543 /* Fix endianness */ 544 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 545 p++) 546 *p = TO_NATIVE(*p); 547 } 548 549 return 1; 550 } 551 552 static void parse_elf_finish(struct elf_info *info) 553 { 554 release_file(info->hdr, info->size); 555 } 556 557 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 558 { 559 /* ignore __this_module, it will be resolved shortly */ 560 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0) 561 return 1; 562 /* ignore global offset table */ 563 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 564 return 1; 565 if (info->hdr->e_machine == EM_PPC) 566 /* Special register function linked on all modules during final link of .ko */ 567 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 || 568 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 || 569 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 || 570 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0) 571 return 1; 572 if (info->hdr->e_machine == EM_PPC64) 573 /* Special register function linked on all modules during final link of .ko */ 574 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 || 575 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0) 576 return 1; 577 /* Do not ignore this symbol */ 578 return 0; 579 } 580 581 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_" 582 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_" 583 584 static void handle_modversions(struct module *mod, struct elf_info *info, 585 Elf_Sym *sym, const char *symname) 586 { 587 unsigned int crc; 588 enum export export; 589 590 if (!is_vmlinux(mod->name) && strncmp(symname, "__ksymtab", 9) == 0) 591 export = export_from_secname(info, get_secindex(info, sym)); 592 else 593 export = export_from_sec(info, get_secindex(info, sym)); 594 595 switch (sym->st_shndx) { 596 case SHN_COMMON: 597 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 598 break; 599 case SHN_ABS: 600 /* CRC'd symbol */ 601 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { 602 crc = (unsigned int) sym->st_value; 603 sym_update_crc(symname + strlen(CRC_PFX), mod, crc, 604 export); 605 } 606 break; 607 case SHN_UNDEF: 608 /* undefined symbol */ 609 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 610 ELF_ST_BIND(sym->st_info) != STB_WEAK) 611 break; 612 if (ignore_undef_symbol(info, symname)) 613 break; 614 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */ 615 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER) 616 /* add compatibility with older glibc */ 617 #ifndef STT_SPARC_REGISTER 618 #define STT_SPARC_REGISTER STT_REGISTER 619 #endif 620 if (info->hdr->e_machine == EM_SPARC || 621 info->hdr->e_machine == EM_SPARCV9) { 622 /* Ignore register directives. */ 623 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 624 break; 625 if (symname[0] == '.') { 626 char *munged = strdup(symname); 627 munged[0] = '_'; 628 munged[1] = toupper(munged[1]); 629 symname = munged; 630 } 631 } 632 #endif 633 634 if (memcmp(symname, MODULE_SYMBOL_PREFIX, 635 strlen(MODULE_SYMBOL_PREFIX)) == 0) { 636 mod->unres = 637 alloc_symbol(symname + 638 strlen(MODULE_SYMBOL_PREFIX), 639 ELF_ST_BIND(sym->st_info) == STB_WEAK, 640 mod->unres); 641 } 642 break; 643 default: 644 /* All exported symbols */ 645 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) { 646 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod, 647 export); 648 } 649 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0) 650 mod->has_init = 1; 651 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0) 652 mod->has_cleanup = 1; 653 break; 654 } 655 } 656 657 /** 658 * Parse tag=value strings from .modinfo section 659 **/ 660 static char *next_string(char *string, unsigned long *secsize) 661 { 662 /* Skip non-zero chars */ 663 while (string[0]) { 664 string++; 665 if ((*secsize)-- <= 1) 666 return NULL; 667 } 668 669 /* Skip any zero padding. */ 670 while (!string[0]) { 671 string++; 672 if ((*secsize)-- <= 1) 673 return NULL; 674 } 675 return string; 676 } 677 678 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len, 679 const char *tag, char *info) 680 { 681 char *p; 682 unsigned int taglen = strlen(tag); 683 unsigned long size = modinfo_len; 684 685 if (info) { 686 size -= info - (char *)modinfo; 687 modinfo = next_string(info, &size); 688 } 689 690 for (p = modinfo; p; p = next_string(p, &size)) { 691 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 692 return p + taglen + 1; 693 } 694 return NULL; 695 } 696 697 static char *get_modinfo(void *modinfo, unsigned long modinfo_len, 698 const char *tag) 699 700 { 701 return get_next_modinfo(modinfo, modinfo_len, tag, NULL); 702 } 703 704 /** 705 * Test if string s ends in string sub 706 * return 0 if match 707 **/ 708 static int strrcmp(const char *s, const char *sub) 709 { 710 int slen, sublen; 711 712 if (!s || !sub) 713 return 1; 714 715 slen = strlen(s); 716 sublen = strlen(sub); 717 718 if ((slen == 0) || (sublen == 0)) 719 return 1; 720 721 if (sublen > slen) 722 return 1; 723 724 return memcmp(s + slen - sublen, sub, sublen); 725 } 726 727 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 728 { 729 if (sym) 730 return elf->strtab + sym->st_name; 731 else 732 return "(unknown)"; 733 } 734 735 static const char *sec_name(struct elf_info *elf, int secindex) 736 { 737 Elf_Shdr *sechdrs = elf->sechdrs; 738 return (void *)elf->hdr + 739 elf->sechdrs[elf->secindex_strings].sh_offset + 740 sechdrs[secindex].sh_name; 741 } 742 743 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr) 744 { 745 return (void *)elf->hdr + 746 elf->sechdrs[elf->secindex_strings].sh_offset + 747 sechdr->sh_name; 748 } 749 750 /* if sym is empty or point to a string 751 * like ".[0-9]+" then return 1. 752 * This is the optional prefix added by ld to some sections 753 */ 754 static int number_prefix(const char *sym) 755 { 756 if (*sym++ == '\0') 757 return 1; 758 if (*sym != '.') 759 return 0; 760 do { 761 char c = *sym++; 762 if (c < '0' || c > '9') 763 return 0; 764 } while (*sym); 765 return 1; 766 } 767 768 /* The pattern is an array of simple patterns. 769 * "foo" will match an exact string equal to "foo" 770 * "*foo" will match a string that ends with "foo" 771 * "foo*" will match a string that begins with "foo" 772 * "foo$" will match a string equal to "foo" or "foo.1" 773 * where the '1' can be any number including several digits. 774 * The $ syntax is for sections where ld append a dot number 775 * to make section name unique. 776 */ 777 static int match(const char *sym, const char * const pat[]) 778 { 779 const char *p; 780 while (*pat) { 781 p = *pat++; 782 const char *endp = p + strlen(p) - 1; 783 784 /* "*foo" */ 785 if (*p == '*') { 786 if (strrcmp(sym, p + 1) == 0) 787 return 1; 788 } 789 /* "foo*" */ 790 else if (*endp == '*') { 791 if (strncmp(sym, p, strlen(p) - 1) == 0) 792 return 1; 793 } 794 /* "foo$" */ 795 else if (*endp == '$') { 796 if (strncmp(sym, p, strlen(p) - 1) == 0) { 797 if (number_prefix(sym + strlen(p) - 1)) 798 return 1; 799 } 800 } 801 /* no wildcards */ 802 else { 803 if (strcmp(p, sym) == 0) 804 return 1; 805 } 806 } 807 /* no match */ 808 return 0; 809 } 810 811 /* sections that we do not want to do full section mismatch check on */ 812 static const char *section_white_list[] = 813 { 814 ".comment*", 815 ".debug*", 816 ".zdebug*", /* Compressed debug sections. */ 817 ".GCC-command-line", /* mn10300 */ 818 ".mdebug*", /* alpha, score, mips etc. */ 819 ".pdr", /* alpha, score, mips etc. */ 820 ".stab*", 821 ".note*", 822 ".got*", 823 ".toc*", 824 NULL 825 }; 826 827 /* 828 * This is used to find sections missing the SHF_ALLOC flag. 829 * The cause of this is often a section specified in assembler 830 * without "ax" / "aw". 831 */ 832 static void check_section(const char *modname, struct elf_info *elf, 833 Elf_Shdr *sechdr) 834 { 835 const char *sec = sech_name(elf, sechdr); 836 837 if (sechdr->sh_type == SHT_PROGBITS && 838 !(sechdr->sh_flags & SHF_ALLOC) && 839 !match(sec, section_white_list)) { 840 warn("%s (%s): unexpected non-allocatable section.\n" 841 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 842 "Note that for example <linux/init.h> contains\n" 843 "section definitions for use in .S files.\n\n", 844 modname, sec); 845 } 846 } 847 848 849 850 #define ALL_INIT_DATA_SECTIONS \ 851 ".init.setup$", ".init.rodata$", \ 852 ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$" \ 853 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$" 854 #define ALL_EXIT_DATA_SECTIONS \ 855 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$" 856 857 #define ALL_INIT_TEXT_SECTIONS \ 858 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$" 859 #define ALL_EXIT_TEXT_SECTIONS \ 860 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$" 861 862 #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \ 863 MEM_INIT_SECTIONS 864 #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \ 865 MEM_EXIT_SECTIONS 866 867 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 868 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS 869 870 #define DATA_SECTIONS ".data$", ".data.rel$" 871 #define TEXT_SECTIONS ".text$" 872 873 #define INIT_SECTIONS ".init.*" 874 #define DEV_INIT_SECTIONS ".devinit.*" 875 #define CPU_INIT_SECTIONS ".cpuinit.*" 876 #define MEM_INIT_SECTIONS ".meminit.*" 877 878 #define EXIT_SECTIONS ".exit.*" 879 #define DEV_EXIT_SECTIONS ".devexit.*" 880 #define CPU_EXIT_SECTIONS ".cpuexit.*" 881 #define MEM_EXIT_SECTIONS ".memexit.*" 882 883 /* init data sections */ 884 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL }; 885 886 /* all init sections */ 887 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL }; 888 889 /* All init and exit sections (code + data) */ 890 static const char *init_exit_sections[] = 891 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }; 892 893 /* data section */ 894 static const char *data_sections[] = { DATA_SECTIONS, NULL }; 895 896 897 /* symbols in .data that may refer to init/exit sections */ 898 #define DEFAULT_SYMBOL_WHITE_LIST \ 899 "*driver", \ 900 "*_template", /* scsi uses *_template a lot */ \ 901 "*_timer", /* arm uses ops structures named _timer a lot */ \ 902 "*_sht", /* scsi also used *_sht to some extent */ \ 903 "*_ops", \ 904 "*_probe", \ 905 "*_probe_one", \ 906 "*_console" 907 908 static const char *head_sections[] = { ".head.text*", NULL }; 909 static const char *linker_symbols[] = 910 { "__init_begin", "_sinittext", "_einittext", NULL }; 911 912 enum mismatch { 913 TEXT_TO_ANY_INIT, 914 DATA_TO_ANY_INIT, 915 TEXT_TO_ANY_EXIT, 916 DATA_TO_ANY_EXIT, 917 XXXINIT_TO_SOME_INIT, 918 XXXEXIT_TO_SOME_EXIT, 919 ANY_INIT_TO_ANY_EXIT, 920 ANY_EXIT_TO_ANY_INIT, 921 EXPORT_TO_INIT_EXIT, 922 }; 923 924 struct sectioncheck { 925 const char *fromsec[20]; 926 const char *tosec[20]; 927 enum mismatch mismatch; 928 const char *symbol_white_list[20]; 929 }; 930 931 const struct sectioncheck sectioncheck[] = { 932 /* Do not reference init/exit code/data from 933 * normal code and data 934 */ 935 { 936 .fromsec = { TEXT_SECTIONS, NULL }, 937 .tosec = { ALL_INIT_SECTIONS, NULL }, 938 .mismatch = TEXT_TO_ANY_INIT, 939 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 940 }, 941 { 942 .fromsec = { DATA_SECTIONS, NULL }, 943 .tosec = { ALL_XXXINIT_SECTIONS, NULL }, 944 .mismatch = DATA_TO_ANY_INIT, 945 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 946 }, 947 { 948 .fromsec = { DATA_SECTIONS, NULL }, 949 .tosec = { INIT_SECTIONS, NULL }, 950 .mismatch = DATA_TO_ANY_INIT, 951 .symbol_white_list = { 952 "*_template", "*_timer", "*_sht", "*_ops", 953 "*_probe", "*_probe_one", "*_console", NULL 954 }, 955 }, 956 { 957 .fromsec = { TEXT_SECTIONS, NULL }, 958 .tosec = { ALL_EXIT_SECTIONS, NULL }, 959 .mismatch = TEXT_TO_ANY_EXIT, 960 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 961 }, 962 { 963 .fromsec = { DATA_SECTIONS, NULL }, 964 .tosec = { ALL_EXIT_SECTIONS, NULL }, 965 .mismatch = DATA_TO_ANY_EXIT, 966 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 967 }, 968 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */ 969 { 970 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 971 .tosec = { INIT_SECTIONS, NULL }, 972 .mismatch = XXXINIT_TO_SOME_INIT, 973 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 974 }, 975 /* Do not reference cpuinit code/data from meminit code/data */ 976 { 977 .fromsec = { MEM_INIT_SECTIONS, NULL }, 978 .tosec = { CPU_INIT_SECTIONS, NULL }, 979 .mismatch = XXXINIT_TO_SOME_INIT, 980 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 981 }, 982 /* Do not reference meminit code/data from cpuinit code/data */ 983 { 984 .fromsec = { CPU_INIT_SECTIONS, NULL }, 985 .tosec = { MEM_INIT_SECTIONS, NULL }, 986 .mismatch = XXXINIT_TO_SOME_INIT, 987 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 988 }, 989 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */ 990 { 991 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL }, 992 .tosec = { EXIT_SECTIONS, NULL }, 993 .mismatch = XXXEXIT_TO_SOME_EXIT, 994 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 995 }, 996 /* Do not reference cpuexit code/data from memexit code/data */ 997 { 998 .fromsec = { MEM_EXIT_SECTIONS, NULL }, 999 .tosec = { CPU_EXIT_SECTIONS, NULL }, 1000 .mismatch = XXXEXIT_TO_SOME_EXIT, 1001 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1002 }, 1003 /* Do not reference memexit code/data from cpuexit code/data */ 1004 { 1005 .fromsec = { CPU_EXIT_SECTIONS, NULL }, 1006 .tosec = { MEM_EXIT_SECTIONS, NULL }, 1007 .mismatch = XXXEXIT_TO_SOME_EXIT, 1008 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1009 }, 1010 /* Do not use exit code/data from init code */ 1011 { 1012 .fromsec = { ALL_INIT_SECTIONS, NULL }, 1013 .tosec = { ALL_EXIT_SECTIONS, NULL }, 1014 .mismatch = ANY_INIT_TO_ANY_EXIT, 1015 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1016 }, 1017 /* Do not use init code/data from exit code */ 1018 { 1019 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 1020 .tosec = { ALL_INIT_SECTIONS, NULL }, 1021 .mismatch = ANY_EXIT_TO_ANY_INIT, 1022 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1023 }, 1024 /* Do not export init/exit functions or data */ 1025 { 1026 .fromsec = { "__ksymtab*", NULL }, 1027 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL }, 1028 .mismatch = EXPORT_TO_INIT_EXIT, 1029 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1030 } 1031 }; 1032 1033 static const struct sectioncheck *section_mismatch( 1034 const char *fromsec, const char *tosec) 1035 { 1036 int i; 1037 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck); 1038 const struct sectioncheck *check = §ioncheck[0]; 1039 1040 for (i = 0; i < elems; i++) { 1041 if (match(fromsec, check->fromsec) && 1042 match(tosec, check->tosec)) 1043 return check; 1044 check++; 1045 } 1046 return NULL; 1047 } 1048 1049 /** 1050 * Whitelist to allow certain references to pass with no warning. 1051 * 1052 * Pattern 1: 1053 * If a module parameter is declared __initdata and permissions=0 1054 * then this is legal despite the warning generated. 1055 * We cannot see value of permissions here, so just ignore 1056 * this pattern. 1057 * The pattern is identified by: 1058 * tosec = .init.data 1059 * fromsec = .data* 1060 * atsym =__param* 1061 * 1062 * Pattern 1a: 1063 * module_param_call() ops can refer to __init set function if permissions=0 1064 * The pattern is identified by: 1065 * tosec = .init.text 1066 * fromsec = .data* 1067 * atsym = __param_ops_* 1068 * 1069 * Pattern 2: 1070 * Many drivers utilise a *driver container with references to 1071 * add, remove, probe functions etc. 1072 * These functions may often be marked __devinit and we do not want to 1073 * warn here. 1074 * the pattern is identified by: 1075 * tosec = init or exit section 1076 * fromsec = data section 1077 * atsym = *driver, *_template, *_sht, *_ops, *_probe, 1078 * *probe_one, *_console, *_timer 1079 * 1080 * Pattern 3: 1081 * Whitelist all references from .head.text to any init section 1082 * 1083 * Pattern 4: 1084 * Some symbols belong to init section but still it is ok to reference 1085 * these from non-init sections as these symbols don't have any memory 1086 * allocated for them and symbol address and value are same. So even 1087 * if init section is freed, its ok to reference those symbols. 1088 * For ex. symbols marking the init section boundaries. 1089 * This pattern is identified by 1090 * refsymname = __init_begin, _sinittext, _einittext 1091 * 1092 **/ 1093 static int secref_whitelist(const struct sectioncheck *mismatch, 1094 const char *fromsec, const char *fromsym, 1095 const char *tosec, const char *tosym) 1096 { 1097 /* Check for pattern 1 */ 1098 if (match(tosec, init_data_sections) && 1099 match(fromsec, data_sections) && 1100 (strncmp(fromsym, "__param", strlen("__param")) == 0)) 1101 return 0; 1102 1103 /* Check for pattern 1a */ 1104 if (strcmp(tosec, ".init.text") == 0 && 1105 match(fromsec, data_sections) && 1106 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0)) 1107 return 0; 1108 1109 /* Check for pattern 2 */ 1110 if (match(tosec, init_exit_sections) && 1111 match(fromsec, data_sections) && 1112 match(fromsym, mismatch->symbol_white_list)) 1113 return 0; 1114 1115 /* Check for pattern 3 */ 1116 if (match(fromsec, head_sections) && 1117 match(tosec, init_sections)) 1118 return 0; 1119 1120 /* Check for pattern 4 */ 1121 if (match(tosym, linker_symbols)) 1122 return 0; 1123 1124 return 1; 1125 } 1126 1127 /** 1128 * Find symbol based on relocation record info. 1129 * In some cases the symbol supplied is a valid symbol so 1130 * return refsym. If st_name != 0 we assume this is a valid symbol. 1131 * In other cases the symbol needs to be looked up in the symbol table 1132 * based on section and address. 1133 * **/ 1134 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr, 1135 Elf_Sym *relsym) 1136 { 1137 Elf_Sym *sym; 1138 Elf_Sym *near = NULL; 1139 Elf64_Sword distance = 20; 1140 Elf64_Sword d; 1141 unsigned int relsym_secindex; 1142 1143 if (relsym->st_name != 0) 1144 return relsym; 1145 1146 relsym_secindex = get_secindex(elf, relsym); 1147 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1148 if (get_secindex(elf, sym) != relsym_secindex) 1149 continue; 1150 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) 1151 continue; 1152 if (sym->st_value == addr) 1153 return sym; 1154 /* Find a symbol nearby - addr are maybe negative */ 1155 d = sym->st_value - addr; 1156 if (d < 0) 1157 d = addr - sym->st_value; 1158 if (d < distance) { 1159 distance = d; 1160 near = sym; 1161 } 1162 } 1163 /* We need a close match */ 1164 if (distance < 20) 1165 return near; 1166 else 1167 return NULL; 1168 } 1169 1170 static inline int is_arm_mapping_symbol(const char *str) 1171 { 1172 return str[0] == '$' && strchr("atd", str[1]) 1173 && (str[2] == '\0' || str[2] == '.'); 1174 } 1175 1176 /* 1177 * If there's no name there, ignore it; likewise, ignore it if it's 1178 * one of the magic symbols emitted used by current ARM tools. 1179 * 1180 * Otherwise if find_symbols_between() returns those symbols, they'll 1181 * fail the whitelist tests and cause lots of false alarms ... fixable 1182 * only by merging __exit and __init sections into __text, bloating 1183 * the kernel (which is especially evil on embedded platforms). 1184 */ 1185 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 1186 { 1187 const char *name = elf->strtab + sym->st_name; 1188 1189 if (!name || !strlen(name)) 1190 return 0; 1191 return !is_arm_mapping_symbol(name); 1192 } 1193 1194 /* 1195 * Find symbols before or equal addr and after addr - in the section sec. 1196 * If we find two symbols with equal offset prefer one with a valid name. 1197 * The ELF format may have a better way to detect what type of symbol 1198 * it is, but this works for now. 1199 **/ 1200 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr, 1201 const char *sec) 1202 { 1203 Elf_Sym *sym; 1204 Elf_Sym *near = NULL; 1205 Elf_Addr distance = ~0; 1206 1207 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1208 const char *symsec; 1209 1210 if (is_shndx_special(sym->st_shndx)) 1211 continue; 1212 symsec = sec_name(elf, get_secindex(elf, sym)); 1213 if (strcmp(symsec, sec) != 0) 1214 continue; 1215 if (!is_valid_name(elf, sym)) 1216 continue; 1217 if (sym->st_value <= addr) { 1218 if ((addr - sym->st_value) < distance) { 1219 distance = addr - sym->st_value; 1220 near = sym; 1221 } else if ((addr - sym->st_value) == distance) { 1222 near = sym; 1223 } 1224 } 1225 } 1226 return near; 1227 } 1228 1229 /* 1230 * Convert a section name to the function/data attribute 1231 * .init.text => __init 1232 * .cpuinit.data => __cpudata 1233 * .memexitconst => __memconst 1234 * etc. 1235 * 1236 * The memory of returned value has been allocated on a heap. The user of this 1237 * method should free it after usage. 1238 */ 1239 static char *sec2annotation(const char *s) 1240 { 1241 if (match(s, init_exit_sections)) { 1242 char *p = malloc(20); 1243 char *r = p; 1244 1245 *p++ = '_'; 1246 *p++ = '_'; 1247 if (*s == '.') 1248 s++; 1249 while (*s && *s != '.') 1250 *p++ = *s++; 1251 *p = '\0'; 1252 if (*s == '.') 1253 s++; 1254 if (strstr(s, "rodata") != NULL) 1255 strcat(p, "const "); 1256 else if (strstr(s, "data") != NULL) 1257 strcat(p, "data "); 1258 else 1259 strcat(p, " "); 1260 return r; 1261 } else { 1262 return strdup(""); 1263 } 1264 } 1265 1266 static int is_function(Elf_Sym *sym) 1267 { 1268 if (sym) 1269 return ELF_ST_TYPE(sym->st_info) == STT_FUNC; 1270 else 1271 return -1; 1272 } 1273 1274 static void print_section_list(const char * const list[20]) 1275 { 1276 const char *const *s = list; 1277 1278 while (*s) { 1279 fprintf(stderr, "%s", *s); 1280 s++; 1281 if (*s) 1282 fprintf(stderr, ", "); 1283 } 1284 fprintf(stderr, "\n"); 1285 } 1286 1287 /* 1288 * Print a warning about a section mismatch. 1289 * Try to find symbols near it so user can find it. 1290 * Check whitelist before warning - it may be a false positive. 1291 */ 1292 static void report_sec_mismatch(const char *modname, 1293 const struct sectioncheck *mismatch, 1294 const char *fromsec, 1295 unsigned long long fromaddr, 1296 const char *fromsym, 1297 int from_is_func, 1298 const char *tosec, const char *tosym, 1299 int to_is_func) 1300 { 1301 const char *from, *from_p; 1302 const char *to, *to_p; 1303 char *prl_from; 1304 char *prl_to; 1305 1306 switch (from_is_func) { 1307 case 0: from = "variable"; from_p = ""; break; 1308 case 1: from = "function"; from_p = "()"; break; 1309 default: from = "(unknown reference)"; from_p = ""; break; 1310 } 1311 switch (to_is_func) { 1312 case 0: to = "variable"; to_p = ""; break; 1313 case 1: to = "function"; to_p = "()"; break; 1314 default: to = "(unknown reference)"; to_p = ""; break; 1315 } 1316 1317 sec_mismatch_count++; 1318 if (!sec_mismatch_verbose) 1319 return; 1320 1321 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s " 1322 "to the %s %s:%s%s\n", 1323 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec, 1324 tosym, to_p); 1325 1326 switch (mismatch->mismatch) { 1327 case TEXT_TO_ANY_INIT: 1328 prl_from = sec2annotation(fromsec); 1329 prl_to = sec2annotation(tosec); 1330 fprintf(stderr, 1331 "The function %s%s() references\n" 1332 "the %s %s%s%s.\n" 1333 "This is often because %s lacks a %s\n" 1334 "annotation or the annotation of %s is wrong.\n", 1335 prl_from, fromsym, 1336 to, prl_to, tosym, to_p, 1337 fromsym, prl_to, tosym); 1338 free(prl_from); 1339 free(prl_to); 1340 break; 1341 case DATA_TO_ANY_INIT: { 1342 prl_to = sec2annotation(tosec); 1343 fprintf(stderr, 1344 "The variable %s references\n" 1345 "the %s %s%s%s\n" 1346 "If the reference is valid then annotate the\n" 1347 "variable with __init* or __refdata (see linux/init.h) " 1348 "or name the variable:\n", 1349 fromsym, to, prl_to, tosym, to_p); 1350 print_section_list(mismatch->symbol_white_list); 1351 free(prl_to); 1352 break; 1353 } 1354 case TEXT_TO_ANY_EXIT: 1355 prl_to = sec2annotation(tosec); 1356 fprintf(stderr, 1357 "The function %s() references a %s in an exit section.\n" 1358 "Often the %s %s%s has valid usage outside the exit section\n" 1359 "and the fix is to remove the %sannotation of %s.\n", 1360 fromsym, to, to, tosym, to_p, prl_to, tosym); 1361 free(prl_to); 1362 break; 1363 case DATA_TO_ANY_EXIT: { 1364 prl_to = sec2annotation(tosec); 1365 fprintf(stderr, 1366 "The variable %s references\n" 1367 "the %s %s%s%s\n" 1368 "If the reference is valid then annotate the\n" 1369 "variable with __exit* (see linux/init.h) or " 1370 "name the variable:\n", 1371 fromsym, to, prl_to, tosym, to_p); 1372 print_section_list(mismatch->symbol_white_list); 1373 free(prl_to); 1374 break; 1375 } 1376 case XXXINIT_TO_SOME_INIT: 1377 case XXXEXIT_TO_SOME_EXIT: 1378 prl_from = sec2annotation(fromsec); 1379 prl_to = sec2annotation(tosec); 1380 fprintf(stderr, 1381 "The %s %s%s%s references\n" 1382 "a %s %s%s%s.\n" 1383 "If %s is only used by %s then\n" 1384 "annotate %s with a matching annotation.\n", 1385 from, prl_from, fromsym, from_p, 1386 to, prl_to, tosym, to_p, 1387 tosym, fromsym, tosym); 1388 free(prl_from); 1389 free(prl_to); 1390 break; 1391 case ANY_INIT_TO_ANY_EXIT: 1392 prl_from = sec2annotation(fromsec); 1393 prl_to = sec2annotation(tosec); 1394 fprintf(stderr, 1395 "The %s %s%s%s references\n" 1396 "a %s %s%s%s.\n" 1397 "This is often seen when error handling " 1398 "in the init function\n" 1399 "uses functionality in the exit path.\n" 1400 "The fix is often to remove the %sannotation of\n" 1401 "%s%s so it may be used outside an exit section.\n", 1402 from, prl_from, fromsym, from_p, 1403 to, prl_to, tosym, to_p, 1404 prl_to, tosym, to_p); 1405 free(prl_from); 1406 free(prl_to); 1407 break; 1408 case ANY_EXIT_TO_ANY_INIT: 1409 prl_from = sec2annotation(fromsec); 1410 prl_to = sec2annotation(tosec); 1411 fprintf(stderr, 1412 "The %s %s%s%s references\n" 1413 "a %s %s%s%s.\n" 1414 "This is often seen when error handling " 1415 "in the exit function\n" 1416 "uses functionality in the init path.\n" 1417 "The fix is often to remove the %sannotation of\n" 1418 "%s%s so it may be used outside an init section.\n", 1419 from, prl_from, fromsym, from_p, 1420 to, prl_to, tosym, to_p, 1421 prl_to, tosym, to_p); 1422 free(prl_from); 1423 free(prl_to); 1424 break; 1425 case EXPORT_TO_INIT_EXIT: 1426 prl_to = sec2annotation(tosec); 1427 fprintf(stderr, 1428 "The symbol %s is exported and annotated %s\n" 1429 "Fix this by removing the %sannotation of %s " 1430 "or drop the export.\n", 1431 tosym, prl_to, prl_to, tosym); 1432 free(prl_to); 1433 break; 1434 } 1435 fprintf(stderr, "\n"); 1436 } 1437 1438 static void check_section_mismatch(const char *modname, struct elf_info *elf, 1439 Elf_Rela *r, Elf_Sym *sym, const char *fromsec) 1440 { 1441 const char *tosec; 1442 const struct sectioncheck *mismatch; 1443 1444 tosec = sec_name(elf, get_secindex(elf, sym)); 1445 mismatch = section_mismatch(fromsec, tosec); 1446 if (mismatch) { 1447 Elf_Sym *to; 1448 Elf_Sym *from; 1449 const char *tosym; 1450 const char *fromsym; 1451 1452 from = find_elf_symbol2(elf, r->r_offset, fromsec); 1453 fromsym = sym_name(elf, from); 1454 to = find_elf_symbol(elf, r->r_addend, sym); 1455 tosym = sym_name(elf, to); 1456 1457 /* check whitelist - we may ignore it */ 1458 if (secref_whitelist(mismatch, 1459 fromsec, fromsym, tosec, tosym)) { 1460 report_sec_mismatch(modname, mismatch, 1461 fromsec, r->r_offset, fromsym, 1462 is_function(from), tosec, tosym, 1463 is_function(to)); 1464 } 1465 } 1466 } 1467 1468 static unsigned int *reloc_location(struct elf_info *elf, 1469 Elf_Shdr *sechdr, Elf_Rela *r) 1470 { 1471 Elf_Shdr *sechdrs = elf->sechdrs; 1472 int section = sechdr->sh_info; 1473 1474 return (void *)elf->hdr + sechdrs[section].sh_offset + 1475 r->r_offset; 1476 } 1477 1478 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1479 { 1480 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1481 unsigned int *location = reloc_location(elf, sechdr, r); 1482 1483 switch (r_typ) { 1484 case R_386_32: 1485 r->r_addend = TO_NATIVE(*location); 1486 break; 1487 case R_386_PC32: 1488 r->r_addend = TO_NATIVE(*location) + 4; 1489 /* For CONFIG_RELOCATABLE=y */ 1490 if (elf->hdr->e_type == ET_EXEC) 1491 r->r_addend += r->r_offset; 1492 break; 1493 } 1494 return 0; 1495 } 1496 1497 #ifndef R_ARM_CALL 1498 #define R_ARM_CALL 28 1499 #endif 1500 #ifndef R_ARM_JUMP24 1501 #define R_ARM_JUMP24 29 1502 #endif 1503 1504 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1505 { 1506 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1507 1508 switch (r_typ) { 1509 case R_ARM_ABS32: 1510 /* From ARM ABI: (S + A) | T */ 1511 r->r_addend = (int)(long) 1512 (elf->symtab_start + ELF_R_SYM(r->r_info)); 1513 break; 1514 case R_ARM_PC24: 1515 case R_ARM_CALL: 1516 case R_ARM_JUMP24: 1517 /* From ARM ABI: ((S + A) | T) - P */ 1518 r->r_addend = (int)(long)(elf->hdr + 1519 sechdr->sh_offset + 1520 (r->r_offset - sechdr->sh_addr)); 1521 break; 1522 default: 1523 return 1; 1524 } 1525 return 0; 1526 } 1527 1528 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1529 { 1530 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1531 unsigned int *location = reloc_location(elf, sechdr, r); 1532 unsigned int inst; 1533 1534 if (r_typ == R_MIPS_HI16) 1535 return 1; /* skip this */ 1536 inst = TO_NATIVE(*location); 1537 switch (r_typ) { 1538 case R_MIPS_LO16: 1539 r->r_addend = inst & 0xffff; 1540 break; 1541 case R_MIPS_26: 1542 r->r_addend = (inst & 0x03ffffff) << 2; 1543 break; 1544 case R_MIPS_32: 1545 r->r_addend = inst; 1546 break; 1547 } 1548 return 0; 1549 } 1550 1551 static void section_rela(const char *modname, struct elf_info *elf, 1552 Elf_Shdr *sechdr) 1553 { 1554 Elf_Sym *sym; 1555 Elf_Rela *rela; 1556 Elf_Rela r; 1557 unsigned int r_sym; 1558 const char *fromsec; 1559 1560 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; 1561 Elf_Rela *stop = (void *)start + sechdr->sh_size; 1562 1563 fromsec = sech_name(elf, sechdr); 1564 fromsec += strlen(".rela"); 1565 /* if from section (name) is know good then skip it */ 1566 if (match(fromsec, section_white_list)) 1567 return; 1568 1569 for (rela = start; rela < stop; rela++) { 1570 r.r_offset = TO_NATIVE(rela->r_offset); 1571 #if KERNEL_ELFCLASS == ELFCLASS64 1572 if (elf->hdr->e_machine == EM_MIPS) { 1573 unsigned int r_typ; 1574 r_sym = ELF64_MIPS_R_SYM(rela->r_info); 1575 r_sym = TO_NATIVE(r_sym); 1576 r_typ = ELF64_MIPS_R_TYPE(rela->r_info); 1577 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1578 } else { 1579 r.r_info = TO_NATIVE(rela->r_info); 1580 r_sym = ELF_R_SYM(r.r_info); 1581 } 1582 #else 1583 r.r_info = TO_NATIVE(rela->r_info); 1584 r_sym = ELF_R_SYM(r.r_info); 1585 #endif 1586 r.r_addend = TO_NATIVE(rela->r_addend); 1587 sym = elf->symtab_start + r_sym; 1588 /* Skip special sections */ 1589 if (is_shndx_special(sym->st_shndx)) 1590 continue; 1591 check_section_mismatch(modname, elf, &r, sym, fromsec); 1592 } 1593 } 1594 1595 static void section_rel(const char *modname, struct elf_info *elf, 1596 Elf_Shdr *sechdr) 1597 { 1598 Elf_Sym *sym; 1599 Elf_Rel *rel; 1600 Elf_Rela r; 1601 unsigned int r_sym; 1602 const char *fromsec; 1603 1604 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset; 1605 Elf_Rel *stop = (void *)start + sechdr->sh_size; 1606 1607 fromsec = sech_name(elf, sechdr); 1608 fromsec += strlen(".rel"); 1609 /* if from section (name) is know good then skip it */ 1610 if (match(fromsec, section_white_list)) 1611 return; 1612 1613 for (rel = start; rel < stop; rel++) { 1614 r.r_offset = TO_NATIVE(rel->r_offset); 1615 #if KERNEL_ELFCLASS == ELFCLASS64 1616 if (elf->hdr->e_machine == EM_MIPS) { 1617 unsigned int r_typ; 1618 r_sym = ELF64_MIPS_R_SYM(rel->r_info); 1619 r_sym = TO_NATIVE(r_sym); 1620 r_typ = ELF64_MIPS_R_TYPE(rel->r_info); 1621 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1622 } else { 1623 r.r_info = TO_NATIVE(rel->r_info); 1624 r_sym = ELF_R_SYM(r.r_info); 1625 } 1626 #else 1627 r.r_info = TO_NATIVE(rel->r_info); 1628 r_sym = ELF_R_SYM(r.r_info); 1629 #endif 1630 r.r_addend = 0; 1631 switch (elf->hdr->e_machine) { 1632 case EM_386: 1633 if (addend_386_rel(elf, sechdr, &r)) 1634 continue; 1635 break; 1636 case EM_ARM: 1637 if (addend_arm_rel(elf, sechdr, &r)) 1638 continue; 1639 break; 1640 case EM_MIPS: 1641 if (addend_mips_rel(elf, sechdr, &r)) 1642 continue; 1643 break; 1644 } 1645 sym = elf->symtab_start + r_sym; 1646 /* Skip special sections */ 1647 if (is_shndx_special(sym->st_shndx)) 1648 continue; 1649 check_section_mismatch(modname, elf, &r, sym, fromsec); 1650 } 1651 } 1652 1653 /** 1654 * A module includes a number of sections that are discarded 1655 * either when loaded or when used as built-in. 1656 * For loaded modules all functions marked __init and all data 1657 * marked __initdata will be discarded when the module has been initialized. 1658 * Likewise for modules used built-in the sections marked __exit 1659 * are discarded because __exit marked function are supposed to be called 1660 * only when a module is unloaded which never happens for built-in modules. 1661 * The check_sec_ref() function traverses all relocation records 1662 * to find all references to a section that reference a section that will 1663 * be discarded and warns about it. 1664 **/ 1665 static void check_sec_ref(struct module *mod, const char *modname, 1666 struct elf_info *elf) 1667 { 1668 int i; 1669 Elf_Shdr *sechdrs = elf->sechdrs; 1670 1671 /* Walk through all sections */ 1672 for (i = 0; i < elf->num_sections; i++) { 1673 check_section(modname, elf, &elf->sechdrs[i]); 1674 /* We want to process only relocation sections and not .init */ 1675 if (sechdrs[i].sh_type == SHT_RELA) 1676 section_rela(modname, elf, &elf->sechdrs[i]); 1677 else if (sechdrs[i].sh_type == SHT_REL) 1678 section_rel(modname, elf, &elf->sechdrs[i]); 1679 } 1680 } 1681 1682 static void read_symbols(char *modname) 1683 { 1684 const char *symname; 1685 char *version; 1686 char *license; 1687 struct module *mod; 1688 struct elf_info info = { }; 1689 Elf_Sym *sym; 1690 1691 if (!parse_elf(&info, modname)) 1692 return; 1693 1694 mod = new_module(modname); 1695 1696 /* When there's no vmlinux, don't print warnings about 1697 * unresolved symbols (since there'll be too many ;) */ 1698 if (is_vmlinux(modname)) { 1699 have_vmlinux = 1; 1700 mod->skip = 1; 1701 } 1702 1703 license = get_modinfo(info.modinfo, info.modinfo_len, "license"); 1704 if (info.modinfo && !license && !is_vmlinux(modname)) 1705 warn("modpost: missing MODULE_LICENSE() in %s\n" 1706 "see include/linux/module.h for " 1707 "more information\n", modname); 1708 while (license) { 1709 if (license_is_gpl_compatible(license)) 1710 mod->gpl_compatible = 1; 1711 else { 1712 mod->gpl_compatible = 0; 1713 break; 1714 } 1715 license = get_next_modinfo(info.modinfo, info.modinfo_len, 1716 "license", license); 1717 } 1718 1719 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1720 symname = info.strtab + sym->st_name; 1721 1722 handle_modversions(mod, &info, sym, symname); 1723 handle_moddevtable(mod, &info, sym, symname); 1724 } 1725 if (!is_vmlinux(modname) || 1726 (is_vmlinux(modname) && vmlinux_section_warnings)) 1727 check_sec_ref(mod, modname, &info); 1728 1729 version = get_modinfo(info.modinfo, info.modinfo_len, "version"); 1730 if (version) 1731 maybe_frob_rcs_version(modname, version, info.modinfo, 1732 version - (char *)info.hdr); 1733 if (version || (all_versions && !is_vmlinux(modname))) 1734 get_src_version(modname, mod->srcversion, 1735 sizeof(mod->srcversion)-1); 1736 1737 parse_elf_finish(&info); 1738 1739 /* Our trick to get versioning for module struct etc. - it's 1740 * never passed as an argument to an exported function, so 1741 * the automatic versioning doesn't pick it up, but it's really 1742 * important anyhow */ 1743 if (modversions) 1744 mod->unres = alloc_symbol("module_layout", 0, mod->unres); 1745 } 1746 1747 #define SZ 500 1748 1749 /* We first write the generated file into memory using the 1750 * following helper, then compare to the file on disk and 1751 * only update the later if anything changed */ 1752 1753 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1754 const char *fmt, ...) 1755 { 1756 char tmp[SZ]; 1757 int len; 1758 va_list ap; 1759 1760 va_start(ap, fmt); 1761 len = vsnprintf(tmp, SZ, fmt, ap); 1762 buf_write(buf, tmp, len); 1763 va_end(ap); 1764 } 1765 1766 void buf_write(struct buffer *buf, const char *s, int len) 1767 { 1768 if (buf->size - buf->pos < len) { 1769 buf->size += len + SZ; 1770 buf->p = realloc(buf->p, buf->size); 1771 } 1772 strncpy(buf->p + buf->pos, s, len); 1773 buf->pos += len; 1774 } 1775 1776 static void check_for_gpl_usage(enum export exp, const char *m, const char *s) 1777 { 1778 const char *e = is_vmlinux(m) ?"":".ko"; 1779 1780 switch (exp) { 1781 case export_gpl: 1782 fatal("modpost: GPL-incompatible module %s%s " 1783 "uses GPL-only symbol '%s'\n", m, e, s); 1784 break; 1785 case export_unused_gpl: 1786 fatal("modpost: GPL-incompatible module %s%s " 1787 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); 1788 break; 1789 case export_gpl_future: 1790 warn("modpost: GPL-incompatible module %s%s " 1791 "uses future GPL-only symbol '%s'\n", m, e, s); 1792 break; 1793 case export_plain: 1794 case export_unused: 1795 case export_unknown: 1796 /* ignore */ 1797 break; 1798 } 1799 } 1800 1801 static void check_for_unused(enum export exp, const char *m, const char *s) 1802 { 1803 const char *e = is_vmlinux(m) ?"":".ko"; 1804 1805 switch (exp) { 1806 case export_unused: 1807 case export_unused_gpl: 1808 warn("modpost: module %s%s " 1809 "uses symbol '%s' marked UNUSED\n", m, e, s); 1810 break; 1811 default: 1812 /* ignore */ 1813 break; 1814 } 1815 } 1816 1817 static void check_exports(struct module *mod) 1818 { 1819 struct symbol *s, *exp; 1820 1821 for (s = mod->unres; s; s = s->next) { 1822 const char *basename; 1823 exp = find_symbol(s->name); 1824 if (!exp || exp->module == mod) 1825 continue; 1826 basename = strrchr(mod->name, '/'); 1827 if (basename) 1828 basename++; 1829 else 1830 basename = mod->name; 1831 if (!mod->gpl_compatible) 1832 check_for_gpl_usage(exp->export, basename, exp->name); 1833 check_for_unused(exp->export, basename, exp->name); 1834 } 1835 } 1836 1837 /** 1838 * Header for the generated file 1839 **/ 1840 static void add_header(struct buffer *b, struct module *mod) 1841 { 1842 buf_printf(b, "#include <linux/module.h>\n"); 1843 buf_printf(b, "#include <linux/vermagic.h>\n"); 1844 buf_printf(b, "#include <linux/compiler.h>\n"); 1845 buf_printf(b, "\n"); 1846 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1847 buf_printf(b, "\n"); 1848 buf_printf(b, "struct module __this_module\n"); 1849 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); 1850 buf_printf(b, " .name = KBUILD_MODNAME,\n"); 1851 if (mod->has_init) 1852 buf_printf(b, " .init = init_module,\n"); 1853 if (mod->has_cleanup) 1854 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1855 " .exit = cleanup_module,\n" 1856 "#endif\n"); 1857 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n"); 1858 buf_printf(b, "};\n"); 1859 } 1860 1861 static void add_intree_flag(struct buffer *b, int is_intree) 1862 { 1863 if (is_intree) 1864 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1865 } 1866 1867 static void add_staging_flag(struct buffer *b, const char *name) 1868 { 1869 static const char *staging_dir = "drivers/staging"; 1870 1871 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0) 1872 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1873 } 1874 1875 /** 1876 * Record CRCs for unresolved symbols 1877 **/ 1878 static int add_versions(struct buffer *b, struct module *mod) 1879 { 1880 struct symbol *s, *exp; 1881 int err = 0; 1882 1883 for (s = mod->unres; s; s = s->next) { 1884 exp = find_symbol(s->name); 1885 if (!exp || exp->module == mod) { 1886 if (have_vmlinux && !s->weak) { 1887 if (warn_unresolved) { 1888 warn("\"%s\" [%s.ko] undefined!\n", 1889 s->name, mod->name); 1890 } else { 1891 merror("\"%s\" [%s.ko] undefined!\n", 1892 s->name, mod->name); 1893 err = 1; 1894 } 1895 } 1896 continue; 1897 } 1898 s->module = exp->module; 1899 s->crc_valid = exp->crc_valid; 1900 s->crc = exp->crc; 1901 } 1902 1903 if (!modversions) 1904 return err; 1905 1906 buf_printf(b, "\n"); 1907 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1908 buf_printf(b, "__used\n"); 1909 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); 1910 1911 for (s = mod->unres; s; s = s->next) { 1912 if (!s->module) 1913 continue; 1914 if (!s->crc_valid) { 1915 warn("\"%s\" [%s.ko] has no CRC!\n", 1916 s->name, mod->name); 1917 continue; 1918 } 1919 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); 1920 } 1921 1922 buf_printf(b, "};\n"); 1923 1924 return err; 1925 } 1926 1927 static void add_depends(struct buffer *b, struct module *mod, 1928 struct module *modules) 1929 { 1930 struct symbol *s; 1931 struct module *m; 1932 int first = 1; 1933 1934 for (m = modules; m; m = m->next) 1935 m->seen = is_vmlinux(m->name); 1936 1937 buf_printf(b, "\n"); 1938 buf_printf(b, "static const char __module_depends[]\n"); 1939 buf_printf(b, "__used\n"); 1940 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); 1941 buf_printf(b, "\"depends="); 1942 for (s = mod->unres; s; s = s->next) { 1943 const char *p; 1944 if (!s->module) 1945 continue; 1946 1947 if (s->module->seen) 1948 continue; 1949 1950 s->module->seen = 1; 1951 p = strrchr(s->module->name, '/'); 1952 if (p) 1953 p++; 1954 else 1955 p = s->module->name; 1956 buf_printf(b, "%s%s", first ? "" : ",", p); 1957 first = 0; 1958 } 1959 buf_printf(b, "\";\n"); 1960 } 1961 1962 static void add_srcversion(struct buffer *b, struct module *mod) 1963 { 1964 if (mod->srcversion[0]) { 1965 buf_printf(b, "\n"); 1966 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1967 mod->srcversion); 1968 } 1969 } 1970 1971 static void write_if_changed(struct buffer *b, const char *fname) 1972 { 1973 char *tmp; 1974 FILE *file; 1975 struct stat st; 1976 1977 file = fopen(fname, "r"); 1978 if (!file) 1979 goto write; 1980 1981 if (fstat(fileno(file), &st) < 0) 1982 goto close_write; 1983 1984 if (st.st_size != b->pos) 1985 goto close_write; 1986 1987 tmp = NOFAIL(malloc(b->pos)); 1988 if (fread(tmp, 1, b->pos, file) != b->pos) 1989 goto free_write; 1990 1991 if (memcmp(tmp, b->p, b->pos) != 0) 1992 goto free_write; 1993 1994 free(tmp); 1995 fclose(file); 1996 return; 1997 1998 free_write: 1999 free(tmp); 2000 close_write: 2001 fclose(file); 2002 write: 2003 file = fopen(fname, "w"); 2004 if (!file) { 2005 perror(fname); 2006 exit(1); 2007 } 2008 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2009 perror(fname); 2010 exit(1); 2011 } 2012 fclose(file); 2013 } 2014 2015 /* parse Module.symvers file. line format: 2016 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] 2017 **/ 2018 static void read_dump(const char *fname, unsigned int kernel) 2019 { 2020 unsigned long size, pos = 0; 2021 void *file = grab_file(fname, &size); 2022 char *line; 2023 2024 if (!file) 2025 /* No symbol versions, silently ignore */ 2026 return; 2027 2028 while ((line = get_next_line(&pos, file, size))) { 2029 char *symname, *modname, *d, *export, *end; 2030 unsigned int crc; 2031 struct module *mod; 2032 struct symbol *s; 2033 2034 if (!(symname = strchr(line, '\t'))) 2035 goto fail; 2036 *symname++ = '\0'; 2037 if (!(modname = strchr(symname, '\t'))) 2038 goto fail; 2039 *modname++ = '\0'; 2040 if ((export = strchr(modname, '\t')) != NULL) 2041 *export++ = '\0'; 2042 if (export && ((end = strchr(export, '\t')) != NULL)) 2043 *end = '\0'; 2044 crc = strtoul(line, &d, 16); 2045 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2046 goto fail; 2047 mod = find_module(modname); 2048 if (!mod) { 2049 if (is_vmlinux(modname)) 2050 have_vmlinux = 1; 2051 mod = new_module(modname); 2052 mod->skip = 1; 2053 } 2054 s = sym_add_exported(symname, mod, export_no(export)); 2055 s->kernel = kernel; 2056 s->preloaded = 1; 2057 sym_update_crc(symname, mod, crc, export_no(export)); 2058 } 2059 return; 2060 fail: 2061 fatal("parse error in symbol dump file\n"); 2062 } 2063 2064 /* For normal builds always dump all symbols. 2065 * For external modules only dump symbols 2066 * that are not read from kernel Module.symvers. 2067 **/ 2068 static int dump_sym(struct symbol *sym) 2069 { 2070 if (!external_module) 2071 return 1; 2072 if (sym->vmlinux || sym->kernel) 2073 return 0; 2074 return 1; 2075 } 2076 2077 static void write_dump(const char *fname) 2078 { 2079 struct buffer buf = { }; 2080 struct symbol *symbol; 2081 int n; 2082 2083 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { 2084 symbol = symbolhash[n]; 2085 while (symbol) { 2086 if (dump_sym(symbol)) 2087 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", 2088 symbol->crc, symbol->name, 2089 symbol->module->name, 2090 export_str(symbol->export)); 2091 symbol = symbol->next; 2092 } 2093 } 2094 write_if_changed(&buf, fname); 2095 } 2096 2097 struct ext_sym_list { 2098 struct ext_sym_list *next; 2099 const char *file; 2100 }; 2101 2102 int main(int argc, char **argv) 2103 { 2104 struct module *mod; 2105 struct buffer buf = { }; 2106 char *kernel_read = NULL, *module_read = NULL; 2107 char *dump_write = NULL; 2108 int opt; 2109 int err; 2110 struct ext_sym_list *extsym_iter; 2111 struct ext_sym_list *extsym_start = NULL; 2112 2113 while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) { 2114 switch (opt) { 2115 case 'i': 2116 kernel_read = optarg; 2117 break; 2118 case 'I': 2119 module_read = optarg; 2120 external_module = 1; 2121 break; 2122 case 'c': 2123 cross_build = 1; 2124 break; 2125 case 'e': 2126 external_module = 1; 2127 extsym_iter = 2128 NOFAIL(malloc(sizeof(*extsym_iter))); 2129 extsym_iter->next = extsym_start; 2130 extsym_iter->file = optarg; 2131 extsym_start = extsym_iter; 2132 break; 2133 case 'm': 2134 modversions = 1; 2135 break; 2136 case 'o': 2137 dump_write = optarg; 2138 break; 2139 case 'a': 2140 all_versions = 1; 2141 break; 2142 case 's': 2143 vmlinux_section_warnings = 0; 2144 break; 2145 case 'S': 2146 sec_mismatch_verbose = 0; 2147 break; 2148 case 'w': 2149 warn_unresolved = 1; 2150 break; 2151 default: 2152 exit(1); 2153 } 2154 } 2155 2156 if (kernel_read) 2157 read_dump(kernel_read, 1); 2158 if (module_read) 2159 read_dump(module_read, 0); 2160 while (extsym_start) { 2161 read_dump(extsym_start->file, 0); 2162 extsym_iter = extsym_start->next; 2163 free(extsym_start); 2164 extsym_start = extsym_iter; 2165 } 2166 2167 while (optind < argc) 2168 read_symbols(argv[optind++]); 2169 2170 for (mod = modules; mod; mod = mod->next) { 2171 if (mod->skip) 2172 continue; 2173 check_exports(mod); 2174 } 2175 2176 err = 0; 2177 2178 for (mod = modules; mod; mod = mod->next) { 2179 char fname[strlen(mod->name) + 10]; 2180 2181 if (mod->skip) 2182 continue; 2183 2184 buf.pos = 0; 2185 2186 add_header(&buf, mod); 2187 add_intree_flag(&buf, !external_module); 2188 add_staging_flag(&buf, mod->name); 2189 err |= add_versions(&buf, mod); 2190 add_depends(&buf, mod, modules); 2191 add_moddevtable(&buf, mod); 2192 add_srcversion(&buf, mod); 2193 2194 sprintf(fname, "%s.mod.c", mod->name); 2195 write_if_changed(&buf, fname); 2196 } 2197 2198 if (dump_write) 2199 write_dump(dump_write); 2200 if (sec_mismatch_count && !sec_mismatch_verbose) 2201 warn("modpost: Found %d section mismatch(es).\n" 2202 "To see full details build your kernel with:\n" 2203 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n", 2204 sec_mismatch_count); 2205 2206 return err; 2207 } 2208