1 /* Postprocess module symbol versions 2 * 3 * Copyright 2003 Kai Germaschewski 4 * Copyright 2002-2004 Rusty Russell, IBM Corporation 5 * Copyright 2006 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 #include <ctype.h> 15 #include "modpost.h" 16 #include "../../include/linux/license.h" 17 18 /* Are we using CONFIG_MODVERSIONS? */ 19 int modversions = 0; 20 /* Warn about undefined symbols? (do so if we have vmlinux) */ 21 int have_vmlinux = 0; 22 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 23 static int all_versions = 0; 24 /* If we are modposting external module set to 1 */ 25 static int external_module = 0; 26 /* Only warn about unresolved symbols */ 27 static int warn_unresolved = 0; 28 /* How a symbol is exported */ 29 enum export { 30 export_plain, export_unused, export_gpl, 31 export_unused_gpl, export_gpl_future, export_unknown 32 }; 33 34 void fatal(const char *fmt, ...) 35 { 36 va_list arglist; 37 38 fprintf(stderr, "FATAL: "); 39 40 va_start(arglist, fmt); 41 vfprintf(stderr, fmt, arglist); 42 va_end(arglist); 43 44 exit(1); 45 } 46 47 void warn(const char *fmt, ...) 48 { 49 va_list arglist; 50 51 fprintf(stderr, "WARNING: "); 52 53 va_start(arglist, fmt); 54 vfprintf(stderr, fmt, arglist); 55 va_end(arglist); 56 } 57 58 static int is_vmlinux(const char *modname) 59 { 60 const char *myname; 61 62 if ((myname = strrchr(modname, '/'))) 63 myname++; 64 else 65 myname = modname; 66 67 return strcmp(myname, "vmlinux") == 0; 68 } 69 70 void *do_nofail(void *ptr, const char *expr) 71 { 72 if (!ptr) { 73 fatal("modpost: Memory allocation failure: %s.\n", expr); 74 } 75 return ptr; 76 } 77 78 /* A list of all modules we processed */ 79 80 static struct module *modules; 81 82 static struct module *find_module(char *modname) 83 { 84 struct module *mod; 85 86 for (mod = modules; mod; mod = mod->next) 87 if (strcmp(mod->name, modname) == 0) 88 break; 89 return mod; 90 } 91 92 static struct module *new_module(char *modname) 93 { 94 struct module *mod; 95 char *p, *s; 96 97 mod = NOFAIL(malloc(sizeof(*mod))); 98 memset(mod, 0, sizeof(*mod)); 99 p = NOFAIL(strdup(modname)); 100 101 /* strip trailing .o */ 102 if ((s = strrchr(p, '.')) != NULL) 103 if (strcmp(s, ".o") == 0) 104 *s = '\0'; 105 106 /* add to list */ 107 mod->name = p; 108 mod->gpl_compatible = -1; 109 mod->next = modules; 110 modules = mod; 111 112 return mod; 113 } 114 115 /* A hash of all exported symbols, 116 * struct symbol is also used for lists of unresolved symbols */ 117 118 #define SYMBOL_HASH_SIZE 1024 119 120 struct symbol { 121 struct symbol *next; 122 struct module *module; 123 unsigned int crc; 124 int crc_valid; 125 unsigned int weak:1; 126 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */ 127 unsigned int kernel:1; /* 1 if symbol is from kernel 128 * (only for external modules) **/ 129 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */ 130 enum export export; /* Type of export */ 131 char name[0]; 132 }; 133 134 static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 135 136 /* This is based on the hash agorithm from gdbm, via tdb */ 137 static inline unsigned int tdb_hash(const char *name) 138 { 139 unsigned value; /* Used to compute the hash value. */ 140 unsigned i; /* Used to cycle through random values. */ 141 142 /* Set the initial value from the key size. */ 143 for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++) 144 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 145 146 return (1103515243 * value + 12345); 147 } 148 149 /** 150 * Allocate a new symbols for use in the hash of exported symbols or 151 * the list of unresolved symbols per module 152 **/ 153 static struct symbol *alloc_symbol(const char *name, unsigned int weak, 154 struct symbol *next) 155 { 156 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 157 158 memset(s, 0, sizeof(*s)); 159 strcpy(s->name, name); 160 s->weak = weak; 161 s->next = next; 162 return s; 163 } 164 165 /* For the hash of exported symbols */ 166 static struct symbol *new_symbol(const char *name, struct module *module, 167 enum export export) 168 { 169 unsigned int hash; 170 struct symbol *new; 171 172 hash = tdb_hash(name) % SYMBOL_HASH_SIZE; 173 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]); 174 new->module = module; 175 new->export = export; 176 return new; 177 } 178 179 static struct symbol *find_symbol(const char *name) 180 { 181 struct symbol *s; 182 183 /* For our purposes, .foo matches foo. PPC64 needs this. */ 184 if (name[0] == '.') 185 name++; 186 187 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s=s->next) { 188 if (strcmp(s->name, name) == 0) 189 return s; 190 } 191 return NULL; 192 } 193 194 static struct { 195 const char *str; 196 enum export export; 197 } export_list[] = { 198 { .str = "EXPORT_SYMBOL", .export = export_plain }, 199 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused }, 200 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl }, 201 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl }, 202 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future }, 203 { .str = "(unknown)", .export = export_unknown }, 204 }; 205 206 207 static const char *export_str(enum export ex) 208 { 209 return export_list[ex].str; 210 } 211 212 static enum export export_no(const char * s) 213 { 214 int i; 215 if (!s) 216 return export_unknown; 217 for (i = 0; export_list[i].export != export_unknown; i++) { 218 if (strcmp(export_list[i].str, s) == 0) 219 return export_list[i].export; 220 } 221 return export_unknown; 222 } 223 224 static enum export export_from_sec(struct elf_info *elf, Elf_Section sec) 225 { 226 if (sec == elf->export_sec) 227 return export_plain; 228 else if (sec == elf->export_unused_sec) 229 return export_unused; 230 else if (sec == elf->export_gpl_sec) 231 return export_gpl; 232 else if (sec == elf->export_unused_gpl_sec) 233 return export_unused_gpl; 234 else if (sec == elf->export_gpl_future_sec) 235 return export_gpl_future; 236 else 237 return export_unknown; 238 } 239 240 /** 241 * Add an exported symbol - it may have already been added without a 242 * CRC, in this case just update the CRC 243 **/ 244 static struct symbol *sym_add_exported(const char *name, struct module *mod, 245 enum export export) 246 { 247 struct symbol *s = find_symbol(name); 248 249 if (!s) { 250 s = new_symbol(name, mod, export); 251 } else { 252 if (!s->preloaded) { 253 warn("%s: '%s' exported twice. Previous export " 254 "was in %s%s\n", mod->name, name, 255 s->module->name, 256 is_vmlinux(s->module->name) ?"":".ko"); 257 } 258 } 259 s->preloaded = 0; 260 s->vmlinux = is_vmlinux(mod->name); 261 s->kernel = 0; 262 s->export = export; 263 return s; 264 } 265 266 static void sym_update_crc(const char *name, struct module *mod, 267 unsigned int crc, enum export export) 268 { 269 struct symbol *s = find_symbol(name); 270 271 if (!s) 272 s = new_symbol(name, mod, export); 273 s->crc = crc; 274 s->crc_valid = 1; 275 } 276 277 void *grab_file(const char *filename, unsigned long *size) 278 { 279 struct stat st; 280 void *map; 281 int fd; 282 283 fd = open(filename, O_RDONLY); 284 if (fd < 0 || fstat(fd, &st) != 0) 285 return NULL; 286 287 *size = st.st_size; 288 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 289 close(fd); 290 291 if (map == MAP_FAILED) 292 return NULL; 293 return map; 294 } 295 296 /** 297 * Return a copy of the next line in a mmap'ed file. 298 * spaces in the beginning of the line is trimmed away. 299 * Return a pointer to a static buffer. 300 **/ 301 char* get_next_line(unsigned long *pos, void *file, unsigned long size) 302 { 303 static char line[4096]; 304 int skip = 1; 305 size_t len = 0; 306 signed char *p = (signed char *)file + *pos; 307 char *s = line; 308 309 for (; *pos < size ; (*pos)++) 310 { 311 if (skip && isspace(*p)) { 312 p++; 313 continue; 314 } 315 skip = 0; 316 if (*p != '\n' && (*pos < size)) { 317 len++; 318 *s++ = *p++; 319 if (len > 4095) 320 break; /* Too long, stop */ 321 } else { 322 /* End of string */ 323 *s = '\0'; 324 return line; 325 } 326 } 327 /* End of buffer */ 328 return NULL; 329 } 330 331 void release_file(void *file, unsigned long size) 332 { 333 munmap(file, size); 334 } 335 336 static void parse_elf(struct elf_info *info, const char *filename) 337 { 338 unsigned int i; 339 Elf_Ehdr *hdr = info->hdr; 340 Elf_Shdr *sechdrs; 341 Elf_Sym *sym; 342 343 hdr = grab_file(filename, &info->size); 344 if (!hdr) { 345 perror(filename); 346 exit(1); 347 } 348 info->hdr = hdr; 349 if (info->size < sizeof(*hdr)) 350 goto truncated; 351 352 /* Fix endianness in ELF header */ 353 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 354 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 355 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 356 hdr->e_machine = TO_NATIVE(hdr->e_machine); 357 sechdrs = (void *)hdr + hdr->e_shoff; 358 info->sechdrs = sechdrs; 359 360 /* Fix endianness in section headers */ 361 for (i = 0; i < hdr->e_shnum; i++) { 362 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 363 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 364 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 365 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 366 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 367 } 368 /* Find symbol table. */ 369 for (i = 1; i < hdr->e_shnum; i++) { 370 const char *secstrings 371 = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; 372 const char *secname; 373 374 if (sechdrs[i].sh_offset > info->size) 375 goto truncated; 376 secname = secstrings + sechdrs[i].sh_name; 377 if (strcmp(secname, ".modinfo") == 0) { 378 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 379 info->modinfo_len = sechdrs[i].sh_size; 380 } else if (strcmp(secname, "__ksymtab") == 0) 381 info->export_sec = i; 382 else if (strcmp(secname, "__ksymtab_unused") == 0) 383 info->export_unused_sec = i; 384 else if (strcmp(secname, "__ksymtab_gpl") == 0) 385 info->export_gpl_sec = i; 386 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0) 387 info->export_unused_gpl_sec = i; 388 else if (strcmp(secname, "__ksymtab_gpl_future") == 0) 389 info->export_gpl_future_sec = i; 390 391 if (sechdrs[i].sh_type != SHT_SYMTAB) 392 continue; 393 394 info->symtab_start = (void *)hdr + sechdrs[i].sh_offset; 395 info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset 396 + sechdrs[i].sh_size; 397 info->strtab = (void *)hdr + 398 sechdrs[sechdrs[i].sh_link].sh_offset; 399 } 400 if (!info->symtab_start) { 401 fatal("%s has no symtab?\n", filename); 402 } 403 /* Fix endianness in symbols */ 404 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 405 sym->st_shndx = TO_NATIVE(sym->st_shndx); 406 sym->st_name = TO_NATIVE(sym->st_name); 407 sym->st_value = TO_NATIVE(sym->st_value); 408 sym->st_size = TO_NATIVE(sym->st_size); 409 } 410 return; 411 412 truncated: 413 fatal("%s is truncated.\n", filename); 414 } 415 416 static void parse_elf_finish(struct elf_info *info) 417 { 418 release_file(info->hdr, info->size); 419 } 420 421 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_" 422 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_" 423 424 static void handle_modversions(struct module *mod, struct elf_info *info, 425 Elf_Sym *sym, const char *symname) 426 { 427 unsigned int crc; 428 enum export export = export_from_sec(info, sym->st_shndx); 429 430 switch (sym->st_shndx) { 431 case SHN_COMMON: 432 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 433 break; 434 case SHN_ABS: 435 /* CRC'd symbol */ 436 if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { 437 crc = (unsigned int) sym->st_value; 438 sym_update_crc(symname + strlen(CRC_PFX), mod, crc, 439 export); 440 } 441 break; 442 case SHN_UNDEF: 443 /* undefined symbol */ 444 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 445 ELF_ST_BIND(sym->st_info) != STB_WEAK) 446 break; 447 /* ignore global offset table */ 448 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 449 break; 450 /* ignore __this_module, it will be resolved shortly */ 451 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0) 452 break; 453 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */ 454 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER) 455 /* add compatibility with older glibc */ 456 #ifndef STT_SPARC_REGISTER 457 #define STT_SPARC_REGISTER STT_REGISTER 458 #endif 459 if (info->hdr->e_machine == EM_SPARC || 460 info->hdr->e_machine == EM_SPARCV9) { 461 /* Ignore register directives. */ 462 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 463 break; 464 if (symname[0] == '.') { 465 char *munged = strdup(symname); 466 munged[0] = '_'; 467 munged[1] = toupper(munged[1]); 468 symname = munged; 469 } 470 } 471 #endif 472 473 if (memcmp(symname, MODULE_SYMBOL_PREFIX, 474 strlen(MODULE_SYMBOL_PREFIX)) == 0) 475 mod->unres = alloc_symbol(symname + 476 strlen(MODULE_SYMBOL_PREFIX), 477 ELF_ST_BIND(sym->st_info) == STB_WEAK, 478 mod->unres); 479 break; 480 default: 481 /* All exported symbols */ 482 if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) { 483 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod, 484 export); 485 } 486 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0) 487 mod->has_init = 1; 488 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0) 489 mod->has_cleanup = 1; 490 break; 491 } 492 } 493 494 /** 495 * Parse tag=value strings from .modinfo section 496 **/ 497 static char *next_string(char *string, unsigned long *secsize) 498 { 499 /* Skip non-zero chars */ 500 while (string[0]) { 501 string++; 502 if ((*secsize)-- <= 1) 503 return NULL; 504 } 505 506 /* Skip any zero padding. */ 507 while (!string[0]) { 508 string++; 509 if ((*secsize)-- <= 1) 510 return NULL; 511 } 512 return string; 513 } 514 515 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len, 516 const char *tag, char *info) 517 { 518 char *p; 519 unsigned int taglen = strlen(tag); 520 unsigned long size = modinfo_len; 521 522 if (info) { 523 size -= info - (char *)modinfo; 524 modinfo = next_string(info, &size); 525 } 526 527 for (p = modinfo; p; p = next_string(p, &size)) { 528 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 529 return p + taglen + 1; 530 } 531 return NULL; 532 } 533 534 static char *get_modinfo(void *modinfo, unsigned long modinfo_len, 535 const char *tag) 536 537 { 538 return get_next_modinfo(modinfo, modinfo_len, tag, NULL); 539 } 540 541 /** 542 * Test if string s ends in string sub 543 * return 0 if match 544 **/ 545 static int strrcmp(const char *s, const char *sub) 546 { 547 int slen, sublen; 548 549 if (!s || !sub) 550 return 1; 551 552 slen = strlen(s); 553 sublen = strlen(sub); 554 555 if ((slen == 0) || (sublen == 0)) 556 return 1; 557 558 if (sublen > slen) 559 return 1; 560 561 return memcmp(s + slen - sublen, sub, sublen); 562 } 563 564 /** 565 * Whitelist to allow certain references to pass with no warning. 566 * Pattern 1: 567 * If a module parameter is declared __initdata and permissions=0 568 * then this is legal despite the warning generated. 569 * We cannot see value of permissions here, so just ignore 570 * this pattern. 571 * The pattern is identified by: 572 * tosec = .init.data 573 * fromsec = .data* 574 * atsym =__param* 575 * 576 * Pattern 2: 577 * Many drivers utilise a *driver container with references to 578 * add, remove, probe functions etc. 579 * These functions may often be marked __init and we do not want to 580 * warn here. 581 * the pattern is identified by: 582 * tosec = .init.text | .exit.text | .init.data 583 * fromsec = .data 584 * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one 585 **/ 586 static int secref_whitelist(const char *modname, const char *tosec, 587 const char *fromsec, const char *atsym) 588 { 589 int f1 = 1, f2 = 1; 590 const char **s; 591 const char *pat2sym[] = { 592 "driver", 593 "_template", /* scsi uses *_template a lot */ 594 "_sht", /* scsi also used *_sht to some extent */ 595 "_ops", 596 "_probe", 597 "_probe_one", 598 NULL 599 }; 600 601 /* Check for pattern 1 */ 602 if (strcmp(tosec, ".init.data") != 0) 603 f1 = 0; 604 if (strncmp(fromsec, ".data", strlen(".data")) != 0) 605 f1 = 0; 606 if (strncmp(atsym, "__param", strlen("__param")) != 0) 607 f1 = 0; 608 609 if (f1) 610 return f1; 611 612 /* Check for pattern 2 */ 613 if ((strcmp(tosec, ".init.text") != 0) && 614 (strcmp(tosec, ".exit.text") != 0) && 615 (strcmp(tosec, ".init.data") != 0)) 616 f2 = 0; 617 if (strcmp(fromsec, ".data") != 0) 618 f2 = 0; 619 620 for (s = pat2sym; *s; s++) 621 if (strrcmp(atsym, *s) == 0) 622 f1 = 1; 623 if (f1 && f2) 624 return 1; 625 626 /* Whitelist all references from .pci_fixup section if vmlinux */ 627 if (is_vmlinux(modname)) { 628 if ((strcmp(fromsec, ".pci_fixup") == 0) && 629 (strcmp(tosec, ".init.text") == 0)) 630 return 1; 631 } 632 return 0; 633 } 634 635 /** 636 * Find symbol based on relocation record info. 637 * In some cases the symbol supplied is a valid symbol so 638 * return refsym. If st_name != 0 we assume this is a valid symbol. 639 * In other cases the symbol needs to be looked up in the symbol table 640 * based on section and address. 641 * **/ 642 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr, 643 Elf_Sym *relsym) 644 { 645 Elf_Sym *sym; 646 647 if (relsym->st_name != 0) 648 return relsym; 649 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 650 if (sym->st_shndx != relsym->st_shndx) 651 continue; 652 if (sym->st_value == addr) 653 return sym; 654 } 655 return NULL; 656 } 657 658 /* 659 * Find symbols before or equal addr and after addr - in the section sec. 660 * If we find two symbols with equal offset prefer one with a valid name. 661 * The ELF format may have a better way to detect what type of symbol 662 * it is, but this works for now. 663 **/ 664 static void find_symbols_between(struct elf_info *elf, Elf_Addr addr, 665 const char *sec, 666 Elf_Sym **before, Elf_Sym **after) 667 { 668 Elf_Sym *sym; 669 Elf_Ehdr *hdr = elf->hdr; 670 Elf_Addr beforediff = ~0; 671 Elf_Addr afterdiff = ~0; 672 const char *secstrings = (void *)hdr + 673 elf->sechdrs[hdr->e_shstrndx].sh_offset; 674 675 *before = NULL; 676 *after = NULL; 677 678 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 679 const char *symsec; 680 681 if (sym->st_shndx >= SHN_LORESERVE) 682 continue; 683 symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name; 684 if (strcmp(symsec, sec) != 0) 685 continue; 686 if (sym->st_value <= addr) { 687 if ((addr - sym->st_value) < beforediff) { 688 beforediff = addr - sym->st_value; 689 *before = sym; 690 } 691 else if ((addr - sym->st_value) == beforediff) { 692 /* equal offset, valid name? */ 693 const char *name = elf->strtab + sym->st_name; 694 if (name && strlen(name)) 695 *before = sym; 696 } 697 } 698 else 699 { 700 if ((sym->st_value - addr) < afterdiff) { 701 afterdiff = sym->st_value - addr; 702 *after = sym; 703 } 704 else if ((sym->st_value - addr) == afterdiff) { 705 /* equal offset, valid name? */ 706 const char *name = elf->strtab + sym->st_name; 707 if (name && strlen(name)) 708 *after = sym; 709 } 710 } 711 } 712 } 713 714 /** 715 * Print a warning about a section mismatch. 716 * Try to find symbols near it so user can find it. 717 * Check whitelist before warning - it may be a false positive. 718 **/ 719 static void warn_sec_mismatch(const char *modname, const char *fromsec, 720 struct elf_info *elf, Elf_Sym *sym, Elf_Rela r) 721 { 722 const char *refsymname = ""; 723 Elf_Sym *before, *after; 724 Elf_Sym *refsym; 725 Elf_Ehdr *hdr = elf->hdr; 726 Elf_Shdr *sechdrs = elf->sechdrs; 727 const char *secstrings = (void *)hdr + 728 sechdrs[hdr->e_shstrndx].sh_offset; 729 const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name; 730 731 find_symbols_between(elf, r.r_offset, fromsec, &before, &after); 732 733 refsym = find_elf_symbol(elf, r.r_addend, sym); 734 if (refsym && strlen(elf->strtab + refsym->st_name)) 735 refsymname = elf->strtab + refsym->st_name; 736 737 /* check whitelist - we may ignore it */ 738 if (before && 739 secref_whitelist(modname, secname, fromsec, 740 elf->strtab + before->st_name)) 741 return; 742 743 if (before && after) { 744 warn("%s - Section mismatch: reference to %s:%s from %s " 745 "between '%s' (at offset 0x%llx) and '%s'\n", 746 modname, secname, refsymname, fromsec, 747 elf->strtab + before->st_name, 748 (long long)r.r_offset, 749 elf->strtab + after->st_name); 750 } else if (before) { 751 warn("%s - Section mismatch: reference to %s:%s from %s " 752 "after '%s' (at offset 0x%llx)\n", 753 modname, secname, refsymname, fromsec, 754 elf->strtab + before->st_name, 755 (long long)r.r_offset); 756 } else if (after) { 757 warn("%s - Section mismatch: reference to %s:%s from %s " 758 "before '%s' (at offset -0x%llx)\n", 759 modname, secname, refsymname, fromsec, 760 elf->strtab + after->st_name, 761 (long long)r.r_offset); 762 } else { 763 warn("%s - Section mismatch: reference to %s:%s from %s " 764 "(offset 0x%llx)\n", 765 modname, secname, fromsec, refsymname, 766 (long long)r.r_offset); 767 } 768 } 769 770 /** 771 * A module includes a number of sections that are discarded 772 * either when loaded or when used as built-in. 773 * For loaded modules all functions marked __init and all data 774 * marked __initdata will be discarded when the module has been intialized. 775 * Likewise for modules used built-in the sections marked __exit 776 * are discarded because __exit marked function are supposed to be called 777 * only when a moduel is unloaded which never happes for built-in modules. 778 * The check_sec_ref() function traverses all relocation records 779 * to find all references to a section that reference a section that will 780 * be discarded and warns about it. 781 **/ 782 static void check_sec_ref(struct module *mod, const char *modname, 783 struct elf_info *elf, 784 int section(const char*), 785 int section_ref_ok(const char *)) 786 { 787 int i; 788 Elf_Sym *sym; 789 Elf_Ehdr *hdr = elf->hdr; 790 Elf_Shdr *sechdrs = elf->sechdrs; 791 const char *secstrings = (void *)hdr + 792 sechdrs[hdr->e_shstrndx].sh_offset; 793 794 /* Walk through all sections */ 795 for (i = 0; i < hdr->e_shnum; i++) { 796 const char *name = secstrings + sechdrs[i].sh_name; 797 const char *secname; 798 Elf_Rela r; 799 unsigned int r_sym; 800 /* We want to process only relocation sections and not .init */ 801 if (sechdrs[i].sh_type == SHT_RELA) { 802 Elf_Rela *rela; 803 Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset; 804 Elf_Rela *stop = (void*)start + sechdrs[i].sh_size; 805 name += strlen(".rela"); 806 if (section_ref_ok(name)) 807 continue; 808 809 for (rela = start; rela < stop; rela++) { 810 r.r_offset = TO_NATIVE(rela->r_offset); 811 #if KERNEL_ELFCLASS == ELFCLASS64 812 if (hdr->e_machine == EM_MIPS) { 813 r_sym = ELF64_MIPS_R_SYM(rela->r_info); 814 r_sym = TO_NATIVE(r_sym); 815 } else { 816 r.r_info = TO_NATIVE(rela->r_info); 817 r_sym = ELF_R_SYM(r.r_info); 818 } 819 #else 820 r.r_info = TO_NATIVE(rela->r_info); 821 r_sym = ELF_R_SYM(r.r_info); 822 #endif 823 r.r_addend = TO_NATIVE(rela->r_addend); 824 sym = elf->symtab_start + r_sym; 825 /* Skip special sections */ 826 if (sym->st_shndx >= SHN_LORESERVE) 827 continue; 828 829 secname = secstrings + 830 sechdrs[sym->st_shndx].sh_name; 831 if (section(secname)) 832 warn_sec_mismatch(modname, name, 833 elf, sym, r); 834 } 835 } else if (sechdrs[i].sh_type == SHT_REL) { 836 Elf_Rel *rel; 837 Elf_Rel *start = (void *)hdr + sechdrs[i].sh_offset; 838 Elf_Rel *stop = (void*)start + sechdrs[i].sh_size; 839 name += strlen(".rel"); 840 if (section_ref_ok(name)) 841 continue; 842 843 for (rel = start; rel < stop; rel++) { 844 r.r_offset = TO_NATIVE(rel->r_offset); 845 #if KERNEL_ELFCLASS == ELFCLASS64 846 if (hdr->e_machine == EM_MIPS) { 847 r_sym = ELF64_MIPS_R_SYM(rel->r_info); 848 r_sym = TO_NATIVE(r_sym); 849 } else { 850 r.r_info = TO_NATIVE(rel->r_info); 851 r_sym = ELF_R_SYM(r.r_info); 852 } 853 #else 854 r.r_info = TO_NATIVE(rel->r_info); 855 r_sym = ELF_R_SYM(r.r_info); 856 #endif 857 r.r_addend = 0; 858 sym = elf->symtab_start + r_sym; 859 /* Skip special sections */ 860 if (sym->st_shndx >= SHN_LORESERVE) 861 continue; 862 863 secname = secstrings + 864 sechdrs[sym->st_shndx].sh_name; 865 if (section(secname)) 866 warn_sec_mismatch(modname, name, 867 elf, sym, r); 868 } 869 } 870 } 871 } 872 873 /** 874 * Functions used only during module init is marked __init and is stored in 875 * a .init.text section. Likewise data is marked __initdata and stored in 876 * a .init.data section. 877 * If this section is one of these sections return 1 878 * See include/linux/init.h for the details 879 **/ 880 static int init_section(const char *name) 881 { 882 if (strcmp(name, ".init") == 0) 883 return 1; 884 if (strncmp(name, ".init.", strlen(".init.")) == 0) 885 return 1; 886 return 0; 887 } 888 889 /** 890 * Identify sections from which references to a .init section is OK. 891 * 892 * Unfortunately references to read only data that referenced .init 893 * sections had to be excluded. Almost all of these are false 894 * positives, they are created by gcc. The downside of excluding rodata 895 * is that there really are some user references from rodata to 896 * init code, e.g. drivers/video/vgacon.c: 897 * 898 * const struct consw vga_con = { 899 * con_startup: vgacon_startup, 900 * 901 * where vgacon_startup is __init. If you want to wade through the false 902 * positives, take out the check for rodata. 903 **/ 904 static int init_section_ref_ok(const char *name) 905 { 906 const char **s; 907 /* Absolute section names */ 908 const char *namelist1[] = { 909 ".init", 910 ".opd", /* see comment [OPD] at exit_section_ref_ok() */ 911 ".toc1", /* used by ppc64 */ 912 ".stab", 913 ".rodata", 914 ".parainstructions", 915 ".text.lock", 916 "__bug_table", /* used by powerpc for BUG() */ 917 ".pci_fixup_header", 918 ".pci_fixup_final", 919 ".pdr", 920 "__param", 921 "__ex_table", 922 ".fixup", 923 ".smp_locks", 924 ".plt", /* seen on ARCH=um build on x86_64. Harmless */ 925 "__ftr_fixup", /* powerpc cpu feature fixup */ 926 "__fw_ftr_fixup", /* powerpc firmware feature fixup */ 927 NULL 928 }; 929 /* Start of section names */ 930 const char *namelist2[] = { 931 ".init.", 932 ".altinstructions", 933 ".eh_frame", 934 ".debug", 935 ".parainstructions", 936 NULL 937 }; 938 /* part of section name */ 939 const char *namelist3 [] = { 940 ".unwind", /* sample: IA_64.unwind.init.text */ 941 NULL 942 }; 943 944 for (s = namelist1; *s; s++) 945 if (strcmp(*s, name) == 0) 946 return 1; 947 for (s = namelist2; *s; s++) 948 if (strncmp(*s, name, strlen(*s)) == 0) 949 return 1; 950 for (s = namelist3; *s; s++) 951 if (strstr(name, *s) != NULL) 952 return 1; 953 if (strrcmp(name, ".init") == 0) 954 return 1; 955 return 0; 956 } 957 958 /* 959 * Functions used only during module exit is marked __exit and is stored in 960 * a .exit.text section. Likewise data is marked __exitdata and stored in 961 * a .exit.data section. 962 * If this section is one of these sections return 1 963 * See include/linux/init.h for the details 964 **/ 965 static int exit_section(const char *name) 966 { 967 if (strcmp(name, ".exit.text") == 0) 968 return 1; 969 if (strcmp(name, ".exit.data") == 0) 970 return 1; 971 return 0; 972 973 } 974 975 /* 976 * Identify sections from which references to a .exit section is OK. 977 * 978 * [OPD] Keith Ownes <kaos@sgi.com> commented: 979 * For our future {in}sanity, add a comment that this is the ppc .opd 980 * section, not the ia64 .opd section. 981 * ia64 .opd should not point to discarded sections. 982 * [.rodata] like for .init.text we ignore .rodata references -same reason 983 **/ 984 static int exit_section_ref_ok(const char *name) 985 { 986 const char **s; 987 /* Absolute section names */ 988 const char *namelist1[] = { 989 ".exit.text", 990 ".exit.data", 991 ".init.text", 992 ".rodata", 993 ".opd", /* See comment [OPD] */ 994 ".toc1", /* used by ppc64 */ 995 ".altinstructions", 996 ".pdr", 997 "__bug_table", /* used by powerpc for BUG() */ 998 ".exitcall.exit", 999 ".eh_frame", 1000 ".stab", 1001 "__ex_table", 1002 ".fixup", 1003 ".smp_locks", 1004 ".plt", /* seen on ARCH=um build on x86_64. Harmless */ 1005 NULL 1006 }; 1007 /* Start of section names */ 1008 const char *namelist2[] = { 1009 ".debug", 1010 NULL 1011 }; 1012 /* part of section name */ 1013 const char *namelist3 [] = { 1014 ".unwind", /* Sample: IA_64.unwind.exit.text */ 1015 NULL 1016 }; 1017 1018 for (s = namelist1; *s; s++) 1019 if (strcmp(*s, name) == 0) 1020 return 1; 1021 for (s = namelist2; *s; s++) 1022 if (strncmp(*s, name, strlen(*s)) == 0) 1023 return 1; 1024 for (s = namelist3; *s; s++) 1025 if (strstr(name, *s) != NULL) 1026 return 1; 1027 return 0; 1028 } 1029 1030 static void read_symbols(char *modname) 1031 { 1032 const char *symname; 1033 char *version; 1034 char *license; 1035 struct module *mod; 1036 struct elf_info info = { }; 1037 Elf_Sym *sym; 1038 1039 parse_elf(&info, modname); 1040 1041 mod = new_module(modname); 1042 1043 /* When there's no vmlinux, don't print warnings about 1044 * unresolved symbols (since there'll be too many ;) */ 1045 if (is_vmlinux(modname)) { 1046 have_vmlinux = 1; 1047 mod->skip = 1; 1048 } 1049 1050 license = get_modinfo(info.modinfo, info.modinfo_len, "license"); 1051 while (license) { 1052 if (license_is_gpl_compatible(license)) 1053 mod->gpl_compatible = 1; 1054 else { 1055 mod->gpl_compatible = 0; 1056 break; 1057 } 1058 license = get_next_modinfo(info.modinfo, info.modinfo_len, 1059 "license", license); 1060 } 1061 1062 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1063 symname = info.strtab + sym->st_name; 1064 1065 handle_modversions(mod, &info, sym, symname); 1066 handle_moddevtable(mod, &info, sym, symname); 1067 } 1068 check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok); 1069 check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok); 1070 1071 version = get_modinfo(info.modinfo, info.modinfo_len, "version"); 1072 if (version) 1073 maybe_frob_rcs_version(modname, version, info.modinfo, 1074 version - (char *)info.hdr); 1075 if (version || (all_versions && !is_vmlinux(modname))) 1076 get_src_version(modname, mod->srcversion, 1077 sizeof(mod->srcversion)-1); 1078 1079 parse_elf_finish(&info); 1080 1081 /* Our trick to get versioning for struct_module - it's 1082 * never passed as an argument to an exported function, so 1083 * the automatic versioning doesn't pick it up, but it's really 1084 * important anyhow */ 1085 if (modversions) 1086 mod->unres = alloc_symbol("struct_module", 0, mod->unres); 1087 } 1088 1089 #define SZ 500 1090 1091 /* We first write the generated file into memory using the 1092 * following helper, then compare to the file on disk and 1093 * only update the later if anything changed */ 1094 1095 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1096 const char *fmt, ...) 1097 { 1098 char tmp[SZ]; 1099 int len; 1100 va_list ap; 1101 1102 va_start(ap, fmt); 1103 len = vsnprintf(tmp, SZ, fmt, ap); 1104 buf_write(buf, tmp, len); 1105 va_end(ap); 1106 } 1107 1108 void buf_write(struct buffer *buf, const char *s, int len) 1109 { 1110 if (buf->size - buf->pos < len) { 1111 buf->size += len + SZ; 1112 buf->p = realloc(buf->p, buf->size); 1113 } 1114 strncpy(buf->p + buf->pos, s, len); 1115 buf->pos += len; 1116 } 1117 1118 static void check_for_gpl_usage(enum export exp, const char *m, const char *s) 1119 { 1120 const char *e = is_vmlinux(m) ?"":".ko"; 1121 1122 switch (exp) { 1123 case export_gpl: 1124 fatal("modpost: GPL-incompatible module %s%s " 1125 "uses GPL-only symbol '%s'\n", m, e, s); 1126 break; 1127 case export_unused_gpl: 1128 fatal("modpost: GPL-incompatible module %s%s " 1129 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); 1130 break; 1131 case export_gpl_future: 1132 warn("modpost: GPL-incompatible module %s%s " 1133 "uses future GPL-only symbol '%s'\n", m, e, s); 1134 break; 1135 case export_plain: 1136 case export_unused: 1137 case export_unknown: 1138 /* ignore */ 1139 break; 1140 } 1141 } 1142 1143 static void check_for_unused(enum export exp, const char* m, const char* s) 1144 { 1145 const char *e = is_vmlinux(m) ?"":".ko"; 1146 1147 switch (exp) { 1148 case export_unused: 1149 case export_unused_gpl: 1150 warn("modpost: module %s%s " 1151 "uses symbol '%s' marked UNUSED\n", m, e, s); 1152 break; 1153 default: 1154 /* ignore */ 1155 break; 1156 } 1157 } 1158 1159 static void check_exports(struct module *mod) 1160 { 1161 struct symbol *s, *exp; 1162 1163 for (s = mod->unres; s; s = s->next) { 1164 const char *basename; 1165 exp = find_symbol(s->name); 1166 if (!exp || exp->module == mod) 1167 continue; 1168 basename = strrchr(mod->name, '/'); 1169 if (basename) 1170 basename++; 1171 else 1172 basename = mod->name; 1173 if (!mod->gpl_compatible) 1174 check_for_gpl_usage(exp->export, basename, exp->name); 1175 check_for_unused(exp->export, basename, exp->name); 1176 } 1177 } 1178 1179 /** 1180 * Header for the generated file 1181 **/ 1182 static void add_header(struct buffer *b, struct module *mod) 1183 { 1184 buf_printf(b, "#include <linux/module.h>\n"); 1185 buf_printf(b, "#include <linux/vermagic.h>\n"); 1186 buf_printf(b, "#include <linux/compiler.h>\n"); 1187 buf_printf(b, "\n"); 1188 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1189 buf_printf(b, "\n"); 1190 buf_printf(b, "struct module __this_module\n"); 1191 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); 1192 buf_printf(b, " .name = KBUILD_MODNAME,\n"); 1193 if (mod->has_init) 1194 buf_printf(b, " .init = init_module,\n"); 1195 if (mod->has_cleanup) 1196 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1197 " .exit = cleanup_module,\n" 1198 "#endif\n"); 1199 buf_printf(b, "};\n"); 1200 } 1201 1202 /** 1203 * Record CRCs for unresolved symbols 1204 **/ 1205 static int add_versions(struct buffer *b, struct module *mod) 1206 { 1207 struct symbol *s, *exp; 1208 int err = 0; 1209 1210 for (s = mod->unres; s; s = s->next) { 1211 exp = find_symbol(s->name); 1212 if (!exp || exp->module == mod) { 1213 if (have_vmlinux && !s->weak) { 1214 warn("\"%s\" [%s.ko] undefined!\n", 1215 s->name, mod->name); 1216 err = warn_unresolved ? 0 : 1; 1217 } 1218 continue; 1219 } 1220 s->module = exp->module; 1221 s->crc_valid = exp->crc_valid; 1222 s->crc = exp->crc; 1223 } 1224 1225 if (!modversions) 1226 return err; 1227 1228 buf_printf(b, "\n"); 1229 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1230 buf_printf(b, "__attribute_used__\n"); 1231 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); 1232 1233 for (s = mod->unres; s; s = s->next) { 1234 if (!s->module) { 1235 continue; 1236 } 1237 if (!s->crc_valid) { 1238 warn("\"%s\" [%s.ko] has no CRC!\n", 1239 s->name, mod->name); 1240 continue; 1241 } 1242 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); 1243 } 1244 1245 buf_printf(b, "};\n"); 1246 1247 return err; 1248 } 1249 1250 static void add_depends(struct buffer *b, struct module *mod, 1251 struct module *modules) 1252 { 1253 struct symbol *s; 1254 struct module *m; 1255 int first = 1; 1256 1257 for (m = modules; m; m = m->next) { 1258 m->seen = is_vmlinux(m->name); 1259 } 1260 1261 buf_printf(b, "\n"); 1262 buf_printf(b, "static const char __module_depends[]\n"); 1263 buf_printf(b, "__attribute_used__\n"); 1264 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); 1265 buf_printf(b, "\"depends="); 1266 for (s = mod->unres; s; s = s->next) { 1267 if (!s->module) 1268 continue; 1269 1270 if (s->module->seen) 1271 continue; 1272 1273 s->module->seen = 1; 1274 buf_printf(b, "%s%s", first ? "" : ",", 1275 strrchr(s->module->name, '/') + 1); 1276 first = 0; 1277 } 1278 buf_printf(b, "\";\n"); 1279 } 1280 1281 static void add_srcversion(struct buffer *b, struct module *mod) 1282 { 1283 if (mod->srcversion[0]) { 1284 buf_printf(b, "\n"); 1285 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1286 mod->srcversion); 1287 } 1288 } 1289 1290 static void write_if_changed(struct buffer *b, const char *fname) 1291 { 1292 char *tmp; 1293 FILE *file; 1294 struct stat st; 1295 1296 file = fopen(fname, "r"); 1297 if (!file) 1298 goto write; 1299 1300 if (fstat(fileno(file), &st) < 0) 1301 goto close_write; 1302 1303 if (st.st_size != b->pos) 1304 goto close_write; 1305 1306 tmp = NOFAIL(malloc(b->pos)); 1307 if (fread(tmp, 1, b->pos, file) != b->pos) 1308 goto free_write; 1309 1310 if (memcmp(tmp, b->p, b->pos) != 0) 1311 goto free_write; 1312 1313 free(tmp); 1314 fclose(file); 1315 return; 1316 1317 free_write: 1318 free(tmp); 1319 close_write: 1320 fclose(file); 1321 write: 1322 file = fopen(fname, "w"); 1323 if (!file) { 1324 perror(fname); 1325 exit(1); 1326 } 1327 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1328 perror(fname); 1329 exit(1); 1330 } 1331 fclose(file); 1332 } 1333 1334 /* parse Module.symvers file. line format: 1335 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] 1336 **/ 1337 static void read_dump(const char *fname, unsigned int kernel) 1338 { 1339 unsigned long size, pos = 0; 1340 void *file = grab_file(fname, &size); 1341 char *line; 1342 1343 if (!file) 1344 /* No symbol versions, silently ignore */ 1345 return; 1346 1347 while ((line = get_next_line(&pos, file, size))) { 1348 char *symname, *modname, *d, *export, *end; 1349 unsigned int crc; 1350 struct module *mod; 1351 struct symbol *s; 1352 1353 if (!(symname = strchr(line, '\t'))) 1354 goto fail; 1355 *symname++ = '\0'; 1356 if (!(modname = strchr(symname, '\t'))) 1357 goto fail; 1358 *modname++ = '\0'; 1359 if ((export = strchr(modname, '\t')) != NULL) 1360 *export++ = '\0'; 1361 if (export && ((end = strchr(export, '\t')) != NULL)) 1362 *end = '\0'; 1363 crc = strtoul(line, &d, 16); 1364 if (*symname == '\0' || *modname == '\0' || *d != '\0') 1365 goto fail; 1366 1367 if (!(mod = find_module(modname))) { 1368 if (is_vmlinux(modname)) { 1369 have_vmlinux = 1; 1370 } 1371 mod = new_module(NOFAIL(strdup(modname))); 1372 mod->skip = 1; 1373 } 1374 s = sym_add_exported(symname, mod, export_no(export)); 1375 s->kernel = kernel; 1376 s->preloaded = 1; 1377 sym_update_crc(symname, mod, crc, export_no(export)); 1378 } 1379 return; 1380 fail: 1381 fatal("parse error in symbol dump file\n"); 1382 } 1383 1384 /* For normal builds always dump all symbols. 1385 * For external modules only dump symbols 1386 * that are not read from kernel Module.symvers. 1387 **/ 1388 static int dump_sym(struct symbol *sym) 1389 { 1390 if (!external_module) 1391 return 1; 1392 if (sym->vmlinux || sym->kernel) 1393 return 0; 1394 return 1; 1395 } 1396 1397 static void write_dump(const char *fname) 1398 { 1399 struct buffer buf = { }; 1400 struct symbol *symbol; 1401 int n; 1402 1403 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { 1404 symbol = symbolhash[n]; 1405 while (symbol) { 1406 if (dump_sym(symbol)) 1407 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", 1408 symbol->crc, symbol->name, 1409 symbol->module->name, 1410 export_str(symbol->export)); 1411 symbol = symbol->next; 1412 } 1413 } 1414 write_if_changed(&buf, fname); 1415 } 1416 1417 int main(int argc, char **argv) 1418 { 1419 struct module *mod; 1420 struct buffer buf = { }; 1421 char fname[SZ]; 1422 char *kernel_read = NULL, *module_read = NULL; 1423 char *dump_write = NULL; 1424 int opt; 1425 int err; 1426 1427 while ((opt = getopt(argc, argv, "i:I:mo:aw")) != -1) { 1428 switch(opt) { 1429 case 'i': 1430 kernel_read = optarg; 1431 break; 1432 case 'I': 1433 module_read = optarg; 1434 external_module = 1; 1435 break; 1436 case 'm': 1437 modversions = 1; 1438 break; 1439 case 'o': 1440 dump_write = optarg; 1441 break; 1442 case 'a': 1443 all_versions = 1; 1444 break; 1445 case 'w': 1446 warn_unresolved = 1; 1447 break; 1448 default: 1449 exit(1); 1450 } 1451 } 1452 1453 if (kernel_read) 1454 read_dump(kernel_read, 1); 1455 if (module_read) 1456 read_dump(module_read, 0); 1457 1458 while (optind < argc) { 1459 read_symbols(argv[optind++]); 1460 } 1461 1462 for (mod = modules; mod; mod = mod->next) { 1463 if (mod->skip) 1464 continue; 1465 check_exports(mod); 1466 } 1467 1468 err = 0; 1469 1470 for (mod = modules; mod; mod = mod->next) { 1471 if (mod->skip) 1472 continue; 1473 1474 buf.pos = 0; 1475 1476 add_header(&buf, mod); 1477 err |= add_versions(&buf, mod); 1478 add_depends(&buf, mod, modules); 1479 add_moddevtable(&buf, mod); 1480 add_srcversion(&buf, mod); 1481 1482 sprintf(fname, "%s.mod.c", mod->name); 1483 write_if_changed(&buf, fname); 1484 } 1485 1486 if (dump_write) 1487 write_dump(dump_write); 1488 1489 return err; 1490 } 1491