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 void merror(const char *fmt, ...) 59 { 60 va_list arglist; 61 62 fprintf(stderr, "ERROR: "); 63 64 va_start(arglist, fmt); 65 vfprintf(stderr, fmt, arglist); 66 va_end(arglist); 67 } 68 69 static int is_vmlinux(const char *modname) 70 { 71 const char *myname; 72 73 if ((myname = strrchr(modname, '/'))) 74 myname++; 75 else 76 myname = modname; 77 78 return strcmp(myname, "vmlinux") == 0; 79 } 80 81 void *do_nofail(void *ptr, const char *expr) 82 { 83 if (!ptr) { 84 fatal("modpost: Memory allocation failure: %s.\n", expr); 85 } 86 return ptr; 87 } 88 89 /* A list of all modules we processed */ 90 91 static struct module *modules; 92 93 static struct module *find_module(char *modname) 94 { 95 struct module *mod; 96 97 for (mod = modules; mod; mod = mod->next) 98 if (strcmp(mod->name, modname) == 0) 99 break; 100 return mod; 101 } 102 103 static struct module *new_module(char *modname) 104 { 105 struct module *mod; 106 char *p, *s; 107 108 mod = NOFAIL(malloc(sizeof(*mod))); 109 memset(mod, 0, sizeof(*mod)); 110 p = NOFAIL(strdup(modname)); 111 112 /* strip trailing .o */ 113 if ((s = strrchr(p, '.')) != NULL) 114 if (strcmp(s, ".o") == 0) 115 *s = '\0'; 116 117 /* add to list */ 118 mod->name = p; 119 mod->gpl_compatible = -1; 120 mod->next = modules; 121 modules = mod; 122 123 return mod; 124 } 125 126 /* A hash of all exported symbols, 127 * struct symbol is also used for lists of unresolved symbols */ 128 129 #define SYMBOL_HASH_SIZE 1024 130 131 struct symbol { 132 struct symbol *next; 133 struct module *module; 134 unsigned int crc; 135 int crc_valid; 136 unsigned int weak:1; 137 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */ 138 unsigned int kernel:1; /* 1 if symbol is from kernel 139 * (only for external modules) **/ 140 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */ 141 enum export export; /* Type of export */ 142 char name[0]; 143 }; 144 145 static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 146 147 /* This is based on the hash agorithm from gdbm, via tdb */ 148 static inline unsigned int tdb_hash(const char *name) 149 { 150 unsigned value; /* Used to compute the hash value. */ 151 unsigned i; /* Used to cycle through random values. */ 152 153 /* Set the initial value from the key size. */ 154 for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++) 155 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 156 157 return (1103515243 * value + 12345); 158 } 159 160 /** 161 * Allocate a new symbols for use in the hash of exported symbols or 162 * the list of unresolved symbols per module 163 **/ 164 static struct symbol *alloc_symbol(const char *name, unsigned int weak, 165 struct symbol *next) 166 { 167 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 168 169 memset(s, 0, sizeof(*s)); 170 strcpy(s->name, name); 171 s->weak = weak; 172 s->next = next; 173 return s; 174 } 175 176 /* For the hash of exported symbols */ 177 static struct symbol *new_symbol(const char *name, struct module *module, 178 enum export export) 179 { 180 unsigned int hash; 181 struct symbol *new; 182 183 hash = tdb_hash(name) % SYMBOL_HASH_SIZE; 184 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]); 185 new->module = module; 186 new->export = export; 187 return new; 188 } 189 190 static struct symbol *find_symbol(const char *name) 191 { 192 struct symbol *s; 193 194 /* For our purposes, .foo matches foo. PPC64 needs this. */ 195 if (name[0] == '.') 196 name++; 197 198 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s=s->next) { 199 if (strcmp(s->name, name) == 0) 200 return s; 201 } 202 return NULL; 203 } 204 205 static struct { 206 const char *str; 207 enum export export; 208 } export_list[] = { 209 { .str = "EXPORT_SYMBOL", .export = export_plain }, 210 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused }, 211 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl }, 212 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl }, 213 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future }, 214 { .str = "(unknown)", .export = export_unknown }, 215 }; 216 217 218 static const char *export_str(enum export ex) 219 { 220 return export_list[ex].str; 221 } 222 223 static enum export export_no(const char * s) 224 { 225 int i; 226 if (!s) 227 return export_unknown; 228 for (i = 0; export_list[i].export != export_unknown; i++) { 229 if (strcmp(export_list[i].str, s) == 0) 230 return export_list[i].export; 231 } 232 return export_unknown; 233 } 234 235 static enum export export_from_sec(struct elf_info *elf, Elf_Section sec) 236 { 237 if (sec == elf->export_sec) 238 return export_plain; 239 else if (sec == elf->export_unused_sec) 240 return export_unused; 241 else if (sec == elf->export_gpl_sec) 242 return export_gpl; 243 else if (sec == elf->export_unused_gpl_sec) 244 return export_unused_gpl; 245 else if (sec == elf->export_gpl_future_sec) 246 return export_gpl_future; 247 else 248 return export_unknown; 249 } 250 251 /** 252 * Add an exported symbol - it may have already been added without a 253 * CRC, in this case just update the CRC 254 **/ 255 static struct symbol *sym_add_exported(const char *name, struct module *mod, 256 enum export export) 257 { 258 struct symbol *s = find_symbol(name); 259 260 if (!s) { 261 s = new_symbol(name, mod, export); 262 } else { 263 if (!s->preloaded) { 264 warn("%s: '%s' exported twice. Previous export " 265 "was in %s%s\n", mod->name, name, 266 s->module->name, 267 is_vmlinux(s->module->name) ?"":".ko"); 268 } 269 } 270 s->preloaded = 0; 271 s->vmlinux = is_vmlinux(mod->name); 272 s->kernel = 0; 273 s->export = export; 274 return s; 275 } 276 277 static void sym_update_crc(const char *name, struct module *mod, 278 unsigned int crc, enum export export) 279 { 280 struct symbol *s = find_symbol(name); 281 282 if (!s) 283 s = new_symbol(name, mod, export); 284 s->crc = crc; 285 s->crc_valid = 1; 286 } 287 288 void *grab_file(const char *filename, unsigned long *size) 289 { 290 struct stat st; 291 void *map; 292 int fd; 293 294 fd = open(filename, O_RDONLY); 295 if (fd < 0 || fstat(fd, &st) != 0) 296 return NULL; 297 298 *size = st.st_size; 299 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 300 close(fd); 301 302 if (map == MAP_FAILED) 303 return NULL; 304 return map; 305 } 306 307 /** 308 * Return a copy of the next line in a mmap'ed file. 309 * spaces in the beginning of the line is trimmed away. 310 * Return a pointer to a static buffer. 311 **/ 312 char* get_next_line(unsigned long *pos, void *file, unsigned long size) 313 { 314 static char line[4096]; 315 int skip = 1; 316 size_t len = 0; 317 signed char *p = (signed char *)file + *pos; 318 char *s = line; 319 320 for (; *pos < size ; (*pos)++) 321 { 322 if (skip && isspace(*p)) { 323 p++; 324 continue; 325 } 326 skip = 0; 327 if (*p != '\n' && (*pos < size)) { 328 len++; 329 *s++ = *p++; 330 if (len > 4095) 331 break; /* Too long, stop */ 332 } else { 333 /* End of string */ 334 *s = '\0'; 335 return line; 336 } 337 } 338 /* End of buffer */ 339 return NULL; 340 } 341 342 void release_file(void *file, unsigned long size) 343 { 344 munmap(file, size); 345 } 346 347 static int parse_elf(struct elf_info *info, const char *filename) 348 { 349 unsigned int i; 350 Elf_Ehdr *hdr; 351 Elf_Shdr *sechdrs; 352 Elf_Sym *sym; 353 354 hdr = grab_file(filename, &info->size); 355 if (!hdr) { 356 perror(filename); 357 exit(1); 358 } 359 info->hdr = hdr; 360 if (info->size < sizeof(*hdr)) { 361 /* file too small, assume this is an empty .o file */ 362 return 0; 363 } 364 /* Is this a valid ELF file? */ 365 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 366 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 367 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 368 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 369 /* Not an ELF file - silently ignore it */ 370 return 0; 371 } 372 /* Fix endianness in ELF header */ 373 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 374 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 375 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 376 hdr->e_machine = TO_NATIVE(hdr->e_machine); 377 sechdrs = (void *)hdr + hdr->e_shoff; 378 info->sechdrs = sechdrs; 379 380 /* Fix endianness in section headers */ 381 for (i = 0; i < hdr->e_shnum; i++) { 382 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 383 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 384 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 385 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 386 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 387 } 388 /* Find symbol table. */ 389 for (i = 1; i < hdr->e_shnum; i++) { 390 const char *secstrings 391 = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; 392 const char *secname; 393 394 if (sechdrs[i].sh_offset > info->size) { 395 fatal("%s is truncated. sechdrs[i].sh_offset=%u > sizeof(*hrd)=%ul\n", filename, (unsigned int)sechdrs[i].sh_offset, sizeof(*hdr)); 396 return 0; 397 } 398 secname = secstrings + sechdrs[i].sh_name; 399 if (strcmp(secname, ".modinfo") == 0) { 400 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 401 info->modinfo_len = sechdrs[i].sh_size; 402 } else if (strcmp(secname, "__ksymtab") == 0) 403 info->export_sec = i; 404 else if (strcmp(secname, "__ksymtab_unused") == 0) 405 info->export_unused_sec = i; 406 else if (strcmp(secname, "__ksymtab_gpl") == 0) 407 info->export_gpl_sec = i; 408 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0) 409 info->export_unused_gpl_sec = i; 410 else if (strcmp(secname, "__ksymtab_gpl_future") == 0) 411 info->export_gpl_future_sec = i; 412 413 if (sechdrs[i].sh_type != SHT_SYMTAB) 414 continue; 415 416 info->symtab_start = (void *)hdr + sechdrs[i].sh_offset; 417 info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset 418 + sechdrs[i].sh_size; 419 info->strtab = (void *)hdr + 420 sechdrs[sechdrs[i].sh_link].sh_offset; 421 } 422 if (!info->symtab_start) { 423 fatal("%s has no symtab?\n", filename); 424 } 425 /* Fix endianness in symbols */ 426 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 427 sym->st_shndx = TO_NATIVE(sym->st_shndx); 428 sym->st_name = TO_NATIVE(sym->st_name); 429 sym->st_value = TO_NATIVE(sym->st_value); 430 sym->st_size = TO_NATIVE(sym->st_size); 431 } 432 return 1; 433 } 434 435 static void parse_elf_finish(struct elf_info *info) 436 { 437 release_file(info->hdr, info->size); 438 } 439 440 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_" 441 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_" 442 443 static void handle_modversions(struct module *mod, struct elf_info *info, 444 Elf_Sym *sym, const char *symname) 445 { 446 unsigned int crc; 447 enum export export = export_from_sec(info, sym->st_shndx); 448 449 switch (sym->st_shndx) { 450 case SHN_COMMON: 451 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 452 break; 453 case SHN_ABS: 454 /* CRC'd symbol */ 455 if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { 456 crc = (unsigned int) sym->st_value; 457 sym_update_crc(symname + strlen(CRC_PFX), mod, crc, 458 export); 459 } 460 break; 461 case SHN_UNDEF: 462 /* undefined symbol */ 463 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 464 ELF_ST_BIND(sym->st_info) != STB_WEAK) 465 break; 466 /* ignore global offset table */ 467 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 468 break; 469 /* ignore __this_module, it will be resolved shortly */ 470 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0) 471 break; 472 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */ 473 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER) 474 /* add compatibility with older glibc */ 475 #ifndef STT_SPARC_REGISTER 476 #define STT_SPARC_REGISTER STT_REGISTER 477 #endif 478 if (info->hdr->e_machine == EM_SPARC || 479 info->hdr->e_machine == EM_SPARCV9) { 480 /* Ignore register directives. */ 481 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 482 break; 483 if (symname[0] == '.') { 484 char *munged = strdup(symname); 485 munged[0] = '_'; 486 munged[1] = toupper(munged[1]); 487 symname = munged; 488 } 489 } 490 #endif 491 492 if (memcmp(symname, MODULE_SYMBOL_PREFIX, 493 strlen(MODULE_SYMBOL_PREFIX)) == 0) 494 mod->unres = alloc_symbol(symname + 495 strlen(MODULE_SYMBOL_PREFIX), 496 ELF_ST_BIND(sym->st_info) == STB_WEAK, 497 mod->unres); 498 break; 499 default: 500 /* All exported symbols */ 501 if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) { 502 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod, 503 export); 504 } 505 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0) 506 mod->has_init = 1; 507 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0) 508 mod->has_cleanup = 1; 509 break; 510 } 511 } 512 513 /** 514 * Parse tag=value strings from .modinfo section 515 **/ 516 static char *next_string(char *string, unsigned long *secsize) 517 { 518 /* Skip non-zero chars */ 519 while (string[0]) { 520 string++; 521 if ((*secsize)-- <= 1) 522 return NULL; 523 } 524 525 /* Skip any zero padding. */ 526 while (!string[0]) { 527 string++; 528 if ((*secsize)-- <= 1) 529 return NULL; 530 } 531 return string; 532 } 533 534 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len, 535 const char *tag, char *info) 536 { 537 char *p; 538 unsigned int taglen = strlen(tag); 539 unsigned long size = modinfo_len; 540 541 if (info) { 542 size -= info - (char *)modinfo; 543 modinfo = next_string(info, &size); 544 } 545 546 for (p = modinfo; p; p = next_string(p, &size)) { 547 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 548 return p + taglen + 1; 549 } 550 return NULL; 551 } 552 553 static char *get_modinfo(void *modinfo, unsigned long modinfo_len, 554 const char *tag) 555 556 { 557 return get_next_modinfo(modinfo, modinfo_len, tag, NULL); 558 } 559 560 /** 561 * Test if string s ends in string sub 562 * return 0 if match 563 **/ 564 static int strrcmp(const char *s, const char *sub) 565 { 566 int slen, sublen; 567 568 if (!s || !sub) 569 return 1; 570 571 slen = strlen(s); 572 sublen = strlen(sub); 573 574 if ((slen == 0) || (sublen == 0)) 575 return 1; 576 577 if (sublen > slen) 578 return 1; 579 580 return memcmp(s + slen - sublen, sub, sublen); 581 } 582 583 /** 584 * Whitelist to allow certain references to pass with no warning. 585 * Pattern 1: 586 * If a module parameter is declared __initdata and permissions=0 587 * then this is legal despite the warning generated. 588 * We cannot see value of permissions here, so just ignore 589 * this pattern. 590 * The pattern is identified by: 591 * tosec = .init.data 592 * fromsec = .data* 593 * atsym =__param* 594 * 595 * Pattern 2: 596 * Many drivers utilise a *driver container with references to 597 * add, remove, probe functions etc. 598 * These functions may often be marked __init and we do not want to 599 * warn here. 600 * the pattern is identified by: 601 * tosec = .init.text | .exit.text | .init.data 602 * fromsec = .data 603 * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one, *_console 604 * 605 * Pattern 3: 606 * Whitelist all references from .pci_fixup* section to .init.text 607 * This is part of the PCI init when built-in 608 * 609 * Pattern 4: 610 * Whitelist all refereces from .text.head to .init.data 611 * Whitelist all refereces from .text.head to .init.text 612 * 613 * Pattern 5: 614 * Some symbols belong to init section but still it is ok to reference 615 * these from non-init sections as these symbols don't have any memory 616 * allocated for them and symbol address and value are same. So even 617 * if init section is freed, its ok to reference those symbols. 618 * For ex. symbols marking the init section boundaries. 619 * This pattern is identified by 620 * refsymname = __init_begin, _sinittext, _einittext 621 * 622 * Pattern 6: 623 * During the early init phase we have references from .init.text to 624 * .text we have an intended section mismatch - do not warn about it. 625 * See kernel_init() in init/main.c 626 * tosec = .init.text 627 * fromsec = .text 628 * atsym = kernel_init 629 * 630 * Pattern 7: 631 * Logos used in drivers/video/logo reside in __initdata but the 632 * funtion that references them are EXPORT_SYMBOL() so cannot be 633 * marker __init. So we whitelist them here. 634 * The pattern is: 635 * tosec = .init.data 636 * fromsec = .text* 637 * refsymname = logo_ 638 * 639 * Pattern 8: 640 * Symbols contained in .paravirtprobe may safely reference .init.text. 641 * The pattern is: 642 * tosec = .init.text 643 * fromsec = .paravirtprobe 644 * 645 **/ 646 static int secref_whitelist(const char *modname, const char *tosec, 647 const char *fromsec, const char *atsym, 648 const char *refsymname) 649 { 650 int f1 = 1, f2 = 1; 651 const char **s; 652 const char *pat2sym[] = { 653 "driver", 654 "_template", /* scsi uses *_template a lot */ 655 "_sht", /* scsi also used *_sht to some extent */ 656 "_ops", 657 "_probe", 658 "_probe_one", 659 "_console", 660 "apic_es7000", 661 NULL 662 }; 663 664 const char *pat3refsym[] = { 665 "__init_begin", 666 "_sinittext", 667 "_einittext", 668 NULL 669 }; 670 671 /* Check for pattern 1 */ 672 if (strcmp(tosec, ".init.data") != 0) 673 f1 = 0; 674 if (strncmp(fromsec, ".data", strlen(".data")) != 0) 675 f1 = 0; 676 if (strncmp(atsym, "__param", strlen("__param")) != 0) 677 f1 = 0; 678 679 if (f1) 680 return f1; 681 682 /* Check for pattern 2 */ 683 if ((strcmp(tosec, ".init.text") != 0) && 684 (strcmp(tosec, ".exit.text") != 0) && 685 (strcmp(tosec, ".init.data") != 0)) 686 f2 = 0; 687 if (strcmp(fromsec, ".data") != 0) 688 f2 = 0; 689 690 for (s = pat2sym; *s; s++) 691 if (strrcmp(atsym, *s) == 0) 692 f1 = 1; 693 if (f1 && f2) 694 return 1; 695 696 /* Check for pattern 3 */ 697 if ((strncmp(fromsec, ".pci_fixup", strlen(".pci_fixup")) == 0) && 698 (strcmp(tosec, ".init.text") == 0)) 699 return 1; 700 701 /* Check for pattern 4 */ 702 if ((strcmp(fromsec, ".text.head") == 0) && 703 ((strcmp(tosec, ".init.data") == 0) || 704 (strcmp(tosec, ".init.text") == 0))) 705 return 1; 706 707 /* Check for pattern 5 */ 708 for (s = pat3refsym; *s; s++) 709 if (strcmp(refsymname, *s) == 0) 710 return 1; 711 712 /* Check for pattern 6 */ 713 if ((strcmp(tosec, ".init.text") == 0) && 714 (strcmp(fromsec, ".text") == 0) && 715 (strcmp(refsymname, "kernel_init") == 0)) 716 return 1; 717 718 /* Check for pattern 7 */ 719 if ((strcmp(tosec, ".init.data") == 0) && 720 (strncmp(fromsec, ".text", strlen(".text")) == 0) && 721 (strncmp(refsymname, "logo_", strlen("logo_")) == 0)) 722 return 1; 723 724 /* Check for pattern 8 */ 725 if ((strcmp(tosec, ".init.text") == 0) && 726 (strcmp(fromsec, ".paravirtprobe") == 0)) 727 return 1; 728 729 return 0; 730 } 731 732 /** 733 * Find symbol based on relocation record info. 734 * In some cases the symbol supplied is a valid symbol so 735 * return refsym. If st_name != 0 we assume this is a valid symbol. 736 * In other cases the symbol needs to be looked up in the symbol table 737 * based on section and address. 738 * **/ 739 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr, 740 Elf_Sym *relsym) 741 { 742 Elf_Sym *sym; 743 744 if (relsym->st_name != 0) 745 return relsym; 746 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 747 if (sym->st_shndx != relsym->st_shndx) 748 continue; 749 if (sym->st_value == addr) 750 return sym; 751 } 752 return NULL; 753 } 754 755 static inline int is_arm_mapping_symbol(const char *str) 756 { 757 return str[0] == '$' && strchr("atd", str[1]) 758 && (str[2] == '\0' || str[2] == '.'); 759 } 760 761 /* 762 * If there's no name there, ignore it; likewise, ignore it if it's 763 * one of the magic symbols emitted used by current ARM tools. 764 * 765 * Otherwise if find_symbols_between() returns those symbols, they'll 766 * fail the whitelist tests and cause lots of false alarms ... fixable 767 * only by merging __exit and __init sections into __text, bloating 768 * the kernel (which is especially evil on embedded platforms). 769 */ 770 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 771 { 772 const char *name = elf->strtab + sym->st_name; 773 774 if (!name || !strlen(name)) 775 return 0; 776 return !is_arm_mapping_symbol(name); 777 } 778 779 /* 780 * Find symbols before or equal addr and after addr - in the section sec. 781 * If we find two symbols with equal offset prefer one with a valid name. 782 * The ELF format may have a better way to detect what type of symbol 783 * it is, but this works for now. 784 **/ 785 static void find_symbols_between(struct elf_info *elf, Elf_Addr addr, 786 const char *sec, 787 Elf_Sym **before, Elf_Sym **after) 788 { 789 Elf_Sym *sym; 790 Elf_Ehdr *hdr = elf->hdr; 791 Elf_Addr beforediff = ~0; 792 Elf_Addr afterdiff = ~0; 793 const char *secstrings = (void *)hdr + 794 elf->sechdrs[hdr->e_shstrndx].sh_offset; 795 796 *before = NULL; 797 *after = NULL; 798 799 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 800 const char *symsec; 801 802 if (sym->st_shndx >= SHN_LORESERVE) 803 continue; 804 symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name; 805 if (strcmp(symsec, sec) != 0) 806 continue; 807 if (!is_valid_name(elf, sym)) 808 continue; 809 if (sym->st_value <= addr) { 810 if ((addr - sym->st_value) < beforediff) { 811 beforediff = addr - sym->st_value; 812 *before = sym; 813 } 814 else if ((addr - sym->st_value) == beforediff) { 815 *before = sym; 816 } 817 } 818 else 819 { 820 if ((sym->st_value - addr) < afterdiff) { 821 afterdiff = sym->st_value - addr; 822 *after = sym; 823 } 824 else if ((sym->st_value - addr) == afterdiff) { 825 *after = sym; 826 } 827 } 828 } 829 } 830 831 /** 832 * Print a warning about a section mismatch. 833 * Try to find symbols near it so user can find it. 834 * Check whitelist before warning - it may be a false positive. 835 **/ 836 static void warn_sec_mismatch(const char *modname, const char *fromsec, 837 struct elf_info *elf, Elf_Sym *sym, Elf_Rela r) 838 { 839 const char *refsymname = ""; 840 Elf_Sym *before, *after; 841 Elf_Sym *refsym; 842 Elf_Ehdr *hdr = elf->hdr; 843 Elf_Shdr *sechdrs = elf->sechdrs; 844 const char *secstrings = (void *)hdr + 845 sechdrs[hdr->e_shstrndx].sh_offset; 846 const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name; 847 848 find_symbols_between(elf, r.r_offset, fromsec, &before, &after); 849 850 refsym = find_elf_symbol(elf, r.r_addend, sym); 851 if (refsym && strlen(elf->strtab + refsym->st_name)) 852 refsymname = elf->strtab + refsym->st_name; 853 854 /* check whitelist - we may ignore it */ 855 if (before && 856 secref_whitelist(modname, secname, fromsec, 857 elf->strtab + before->st_name, refsymname)) 858 return; 859 860 if (before && after) { 861 warn("%s - Section mismatch: reference to %s:%s from %s " 862 "between '%s' (at offset 0x%llx) and '%s'\n", 863 modname, secname, refsymname, fromsec, 864 elf->strtab + before->st_name, 865 (long long)r.r_offset, 866 elf->strtab + after->st_name); 867 } else if (before) { 868 warn("%s - Section mismatch: reference to %s:%s from %s " 869 "after '%s' (at offset 0x%llx)\n", 870 modname, secname, refsymname, fromsec, 871 elf->strtab + before->st_name, 872 (long long)r.r_offset); 873 } else if (after) { 874 warn("%s - Section mismatch: reference to %s:%s from %s " 875 "before '%s' (at offset -0x%llx)\n", 876 modname, secname, refsymname, fromsec, 877 elf->strtab + after->st_name, 878 (long long)r.r_offset); 879 } else { 880 warn("%s - Section mismatch: reference to %s:%s from %s " 881 "(offset 0x%llx)\n", 882 modname, secname, fromsec, refsymname, 883 (long long)r.r_offset); 884 } 885 } 886 887 /** 888 * A module includes a number of sections that are discarded 889 * either when loaded or when used as built-in. 890 * For loaded modules all functions marked __init and all data 891 * marked __initdata will be discarded when the module has been intialized. 892 * Likewise for modules used built-in the sections marked __exit 893 * are discarded because __exit marked function are supposed to be called 894 * only when a moduel is unloaded which never happes for built-in modules. 895 * The check_sec_ref() function traverses all relocation records 896 * to find all references to a section that reference a section that will 897 * be discarded and warns about it. 898 **/ 899 static void check_sec_ref(struct module *mod, const char *modname, 900 struct elf_info *elf, 901 int section(const char*), 902 int section_ref_ok(const char *)) 903 { 904 int i; 905 Elf_Sym *sym; 906 Elf_Ehdr *hdr = elf->hdr; 907 Elf_Shdr *sechdrs = elf->sechdrs; 908 const char *secstrings = (void *)hdr + 909 sechdrs[hdr->e_shstrndx].sh_offset; 910 911 /* Walk through all sections */ 912 for (i = 0; i < hdr->e_shnum; i++) { 913 const char *name = secstrings + sechdrs[i].sh_name; 914 const char *secname; 915 Elf_Rela r; 916 unsigned int r_sym; 917 /* We want to process only relocation sections and not .init */ 918 if (sechdrs[i].sh_type == SHT_RELA) { 919 Elf_Rela *rela; 920 Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset; 921 Elf_Rela *stop = (void*)start + sechdrs[i].sh_size; 922 name += strlen(".rela"); 923 if (section_ref_ok(name)) 924 continue; 925 926 for (rela = start; rela < stop; rela++) { 927 r.r_offset = TO_NATIVE(rela->r_offset); 928 #if KERNEL_ELFCLASS == ELFCLASS64 929 if (hdr->e_machine == EM_MIPS) { 930 r_sym = ELF64_MIPS_R_SYM(rela->r_info); 931 r_sym = TO_NATIVE(r_sym); 932 } else { 933 r.r_info = TO_NATIVE(rela->r_info); 934 r_sym = ELF_R_SYM(r.r_info); 935 } 936 #else 937 r.r_info = TO_NATIVE(rela->r_info); 938 r_sym = ELF_R_SYM(r.r_info); 939 #endif 940 r.r_addend = TO_NATIVE(rela->r_addend); 941 sym = elf->symtab_start + r_sym; 942 /* Skip special sections */ 943 if (sym->st_shndx >= SHN_LORESERVE) 944 continue; 945 946 secname = secstrings + 947 sechdrs[sym->st_shndx].sh_name; 948 if (section(secname)) 949 warn_sec_mismatch(modname, name, 950 elf, sym, r); 951 } 952 } else if (sechdrs[i].sh_type == SHT_REL) { 953 Elf_Rel *rel; 954 Elf_Rel *start = (void *)hdr + sechdrs[i].sh_offset; 955 Elf_Rel *stop = (void*)start + sechdrs[i].sh_size; 956 name += strlen(".rel"); 957 if (section_ref_ok(name)) 958 continue; 959 960 for (rel = start; rel < stop; rel++) { 961 r.r_offset = TO_NATIVE(rel->r_offset); 962 #if KERNEL_ELFCLASS == ELFCLASS64 963 if (hdr->e_machine == EM_MIPS) { 964 r_sym = ELF64_MIPS_R_SYM(rel->r_info); 965 r_sym = TO_NATIVE(r_sym); 966 } else { 967 r.r_info = TO_NATIVE(rel->r_info); 968 r_sym = ELF_R_SYM(r.r_info); 969 } 970 #else 971 r.r_info = TO_NATIVE(rel->r_info); 972 r_sym = ELF_R_SYM(r.r_info); 973 #endif 974 r.r_addend = 0; 975 sym = elf->symtab_start + r_sym; 976 /* Skip special sections */ 977 if (sym->st_shndx >= SHN_LORESERVE) 978 continue; 979 980 secname = secstrings + 981 sechdrs[sym->st_shndx].sh_name; 982 if (section(secname)) 983 warn_sec_mismatch(modname, name, 984 elf, sym, r); 985 } 986 } 987 } 988 } 989 990 /** 991 * Functions used only during module init is marked __init and is stored in 992 * a .init.text section. Likewise data is marked __initdata and stored in 993 * a .init.data section. 994 * If this section is one of these sections return 1 995 * See include/linux/init.h for the details 996 **/ 997 static int init_section(const char *name) 998 { 999 if (strcmp(name, ".init") == 0) 1000 return 1; 1001 if (strncmp(name, ".init.", strlen(".init.")) == 0) 1002 return 1; 1003 return 0; 1004 } 1005 1006 /** 1007 * Identify sections from which references to a .init section is OK. 1008 * 1009 * Unfortunately references to read only data that referenced .init 1010 * sections had to be excluded. Almost all of these are false 1011 * positives, they are created by gcc. The downside of excluding rodata 1012 * is that there really are some user references from rodata to 1013 * init code, e.g. drivers/video/vgacon.c: 1014 * 1015 * const struct consw vga_con = { 1016 * con_startup: vgacon_startup, 1017 * 1018 * where vgacon_startup is __init. If you want to wade through the false 1019 * positives, take out the check for rodata. 1020 **/ 1021 static int init_section_ref_ok(const char *name) 1022 { 1023 const char **s; 1024 /* Absolute section names */ 1025 const char *namelist1[] = { 1026 ".init", 1027 ".opd", /* see comment [OPD] at exit_section_ref_ok() */ 1028 ".toc1", /* used by ppc64 */ 1029 ".stab", 1030 ".data.rel.ro", /* used by parisc64 */ 1031 ".parainstructions", 1032 ".text.lock", 1033 "__bug_table", /* used by powerpc for BUG() */ 1034 ".pci_fixup_header", 1035 ".pci_fixup_final", 1036 ".pdr", 1037 "__param", 1038 "__ex_table", 1039 ".fixup", 1040 ".smp_locks", 1041 ".plt", /* seen on ARCH=um build on x86_64. Harmless */ 1042 "__ftr_fixup", /* powerpc cpu feature fixup */ 1043 "__fw_ftr_fixup", /* powerpc firmware feature fixup */ 1044 NULL 1045 }; 1046 /* Start of section names */ 1047 const char *namelist2[] = { 1048 ".init.", 1049 ".altinstructions", 1050 ".eh_frame", 1051 ".debug", 1052 ".parainstructions", 1053 ".rodata", 1054 NULL 1055 }; 1056 /* part of section name */ 1057 const char *namelist3 [] = { 1058 ".unwind", /* sample: IA_64.unwind.init.text */ 1059 NULL 1060 }; 1061 1062 for (s = namelist1; *s; s++) 1063 if (strcmp(*s, name) == 0) 1064 return 1; 1065 for (s = namelist2; *s; s++) 1066 if (strncmp(*s, name, strlen(*s)) == 0) 1067 return 1; 1068 for (s = namelist3; *s; s++) 1069 if (strstr(name, *s) != NULL) 1070 return 1; 1071 if (strrcmp(name, ".init") == 0) 1072 return 1; 1073 return 0; 1074 } 1075 1076 /* 1077 * Functions used only during module exit is marked __exit and is stored in 1078 * a .exit.text section. Likewise data is marked __exitdata and stored in 1079 * a .exit.data section. 1080 * If this section is one of these sections return 1 1081 * See include/linux/init.h for the details 1082 **/ 1083 static int exit_section(const char *name) 1084 { 1085 if (strcmp(name, ".exit.text") == 0) 1086 return 1; 1087 if (strcmp(name, ".exit.data") == 0) 1088 return 1; 1089 return 0; 1090 1091 } 1092 1093 /* 1094 * Identify sections from which references to a .exit section is OK. 1095 * 1096 * [OPD] Keith Ownes <kaos@sgi.com> commented: 1097 * For our future {in}sanity, add a comment that this is the ppc .opd 1098 * section, not the ia64 .opd section. 1099 * ia64 .opd should not point to discarded sections. 1100 * [.rodata] like for .init.text we ignore .rodata references -same reason 1101 **/ 1102 static int exit_section_ref_ok(const char *name) 1103 { 1104 const char **s; 1105 /* Absolute section names */ 1106 const char *namelist1[] = { 1107 ".exit.text", 1108 ".exit.data", 1109 ".init.text", 1110 ".rodata", 1111 ".opd", /* See comment [OPD] */ 1112 ".toc1", /* used by ppc64 */ 1113 ".altinstructions", 1114 ".pdr", 1115 "__bug_table", /* used by powerpc for BUG() */ 1116 ".exitcall.exit", 1117 ".eh_frame", 1118 ".parainstructions", 1119 ".stab", 1120 "__ex_table", 1121 ".fixup", 1122 ".smp_locks", 1123 ".plt", /* seen on ARCH=um build on x86_64. Harmless */ 1124 NULL 1125 }; 1126 /* Start of section names */ 1127 const char *namelist2[] = { 1128 ".debug", 1129 NULL 1130 }; 1131 /* part of section name */ 1132 const char *namelist3 [] = { 1133 ".unwind", /* Sample: IA_64.unwind.exit.text */ 1134 NULL 1135 }; 1136 1137 for (s = namelist1; *s; s++) 1138 if (strcmp(*s, name) == 0) 1139 return 1; 1140 for (s = namelist2; *s; s++) 1141 if (strncmp(*s, name, strlen(*s)) == 0) 1142 return 1; 1143 for (s = namelist3; *s; s++) 1144 if (strstr(name, *s) != NULL) 1145 return 1; 1146 return 0; 1147 } 1148 1149 static void read_symbols(char *modname) 1150 { 1151 const char *symname; 1152 char *version; 1153 char *license; 1154 struct module *mod; 1155 struct elf_info info = { }; 1156 Elf_Sym *sym; 1157 1158 if (!parse_elf(&info, modname)) 1159 return; 1160 1161 mod = new_module(modname); 1162 1163 /* When there's no vmlinux, don't print warnings about 1164 * unresolved symbols (since there'll be too many ;) */ 1165 if (is_vmlinux(modname)) { 1166 have_vmlinux = 1; 1167 mod->skip = 1; 1168 } 1169 1170 license = get_modinfo(info.modinfo, info.modinfo_len, "license"); 1171 while (license) { 1172 if (license_is_gpl_compatible(license)) 1173 mod->gpl_compatible = 1; 1174 else { 1175 mod->gpl_compatible = 0; 1176 break; 1177 } 1178 license = get_next_modinfo(info.modinfo, info.modinfo_len, 1179 "license", license); 1180 } 1181 1182 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1183 symname = info.strtab + sym->st_name; 1184 1185 handle_modversions(mod, &info, sym, symname); 1186 handle_moddevtable(mod, &info, sym, symname); 1187 } 1188 check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok); 1189 check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok); 1190 1191 version = get_modinfo(info.modinfo, info.modinfo_len, "version"); 1192 if (version) 1193 maybe_frob_rcs_version(modname, version, info.modinfo, 1194 version - (char *)info.hdr); 1195 if (version || (all_versions && !is_vmlinux(modname))) 1196 get_src_version(modname, mod->srcversion, 1197 sizeof(mod->srcversion)-1); 1198 1199 parse_elf_finish(&info); 1200 1201 /* Our trick to get versioning for struct_module - it's 1202 * never passed as an argument to an exported function, so 1203 * the automatic versioning doesn't pick it up, but it's really 1204 * important anyhow */ 1205 if (modversions) 1206 mod->unres = alloc_symbol("struct_module", 0, mod->unres); 1207 } 1208 1209 #define SZ 500 1210 1211 /* We first write the generated file into memory using the 1212 * following helper, then compare to the file on disk and 1213 * only update the later if anything changed */ 1214 1215 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1216 const char *fmt, ...) 1217 { 1218 char tmp[SZ]; 1219 int len; 1220 va_list ap; 1221 1222 va_start(ap, fmt); 1223 len = vsnprintf(tmp, SZ, fmt, ap); 1224 buf_write(buf, tmp, len); 1225 va_end(ap); 1226 } 1227 1228 void buf_write(struct buffer *buf, const char *s, int len) 1229 { 1230 if (buf->size - buf->pos < len) { 1231 buf->size += len + SZ; 1232 buf->p = realloc(buf->p, buf->size); 1233 } 1234 strncpy(buf->p + buf->pos, s, len); 1235 buf->pos += len; 1236 } 1237 1238 static void check_for_gpl_usage(enum export exp, const char *m, const char *s) 1239 { 1240 const char *e = is_vmlinux(m) ?"":".ko"; 1241 1242 switch (exp) { 1243 case export_gpl: 1244 fatal("modpost: GPL-incompatible module %s%s " 1245 "uses GPL-only symbol '%s'\n", m, e, s); 1246 break; 1247 case export_unused_gpl: 1248 fatal("modpost: GPL-incompatible module %s%s " 1249 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); 1250 break; 1251 case export_gpl_future: 1252 warn("modpost: GPL-incompatible module %s%s " 1253 "uses future GPL-only symbol '%s'\n", m, e, s); 1254 break; 1255 case export_plain: 1256 case export_unused: 1257 case export_unknown: 1258 /* ignore */ 1259 break; 1260 } 1261 } 1262 1263 static void check_for_unused(enum export exp, const char* m, const char* s) 1264 { 1265 const char *e = is_vmlinux(m) ?"":".ko"; 1266 1267 switch (exp) { 1268 case export_unused: 1269 case export_unused_gpl: 1270 warn("modpost: module %s%s " 1271 "uses symbol '%s' marked UNUSED\n", m, e, s); 1272 break; 1273 default: 1274 /* ignore */ 1275 break; 1276 } 1277 } 1278 1279 static void check_exports(struct module *mod) 1280 { 1281 struct symbol *s, *exp; 1282 1283 for (s = mod->unres; s; s = s->next) { 1284 const char *basename; 1285 exp = find_symbol(s->name); 1286 if (!exp || exp->module == mod) 1287 continue; 1288 basename = strrchr(mod->name, '/'); 1289 if (basename) 1290 basename++; 1291 else 1292 basename = mod->name; 1293 if (!mod->gpl_compatible) 1294 check_for_gpl_usage(exp->export, basename, exp->name); 1295 check_for_unused(exp->export, basename, exp->name); 1296 } 1297 } 1298 1299 /** 1300 * Header for the generated file 1301 **/ 1302 static void add_header(struct buffer *b, struct module *mod) 1303 { 1304 buf_printf(b, "#include <linux/module.h>\n"); 1305 buf_printf(b, "#include <linux/vermagic.h>\n"); 1306 buf_printf(b, "#include <linux/compiler.h>\n"); 1307 buf_printf(b, "\n"); 1308 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1309 buf_printf(b, "\n"); 1310 buf_printf(b, "struct module __this_module\n"); 1311 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); 1312 buf_printf(b, " .name = KBUILD_MODNAME,\n"); 1313 if (mod->has_init) 1314 buf_printf(b, " .init = init_module,\n"); 1315 if (mod->has_cleanup) 1316 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1317 " .exit = cleanup_module,\n" 1318 "#endif\n"); 1319 buf_printf(b, "};\n"); 1320 } 1321 1322 /** 1323 * Record CRCs for unresolved symbols 1324 **/ 1325 static int add_versions(struct buffer *b, struct module *mod) 1326 { 1327 struct symbol *s, *exp; 1328 int err = 0; 1329 1330 for (s = mod->unres; s; s = s->next) { 1331 exp = find_symbol(s->name); 1332 if (!exp || exp->module == mod) { 1333 if (have_vmlinux && !s->weak) { 1334 if (warn_unresolved) { 1335 warn("\"%s\" [%s.ko] undefined!\n", 1336 s->name, mod->name); 1337 } else { 1338 merror("\"%s\" [%s.ko] undefined!\n", 1339 s->name, mod->name); 1340 err = 1; 1341 } 1342 } 1343 continue; 1344 } 1345 s->module = exp->module; 1346 s->crc_valid = exp->crc_valid; 1347 s->crc = exp->crc; 1348 } 1349 1350 if (!modversions) 1351 return err; 1352 1353 buf_printf(b, "\n"); 1354 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1355 buf_printf(b, "__attribute_used__\n"); 1356 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); 1357 1358 for (s = mod->unres; s; s = s->next) { 1359 if (!s->module) { 1360 continue; 1361 } 1362 if (!s->crc_valid) { 1363 warn("\"%s\" [%s.ko] has no CRC!\n", 1364 s->name, mod->name); 1365 continue; 1366 } 1367 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); 1368 } 1369 1370 buf_printf(b, "};\n"); 1371 1372 return err; 1373 } 1374 1375 static void add_depends(struct buffer *b, struct module *mod, 1376 struct module *modules) 1377 { 1378 struct symbol *s; 1379 struct module *m; 1380 int first = 1; 1381 1382 for (m = modules; m; m = m->next) { 1383 m->seen = is_vmlinux(m->name); 1384 } 1385 1386 buf_printf(b, "\n"); 1387 buf_printf(b, "static const char __module_depends[]\n"); 1388 buf_printf(b, "__attribute_used__\n"); 1389 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); 1390 buf_printf(b, "\"depends="); 1391 for (s = mod->unres; s; s = s->next) { 1392 const char *p; 1393 if (!s->module) 1394 continue; 1395 1396 if (s->module->seen) 1397 continue; 1398 1399 s->module->seen = 1; 1400 if ((p = strrchr(s->module->name, '/')) != NULL) 1401 p++; 1402 else 1403 p = s->module->name; 1404 buf_printf(b, "%s%s", first ? "" : ",", p); 1405 first = 0; 1406 } 1407 buf_printf(b, "\";\n"); 1408 } 1409 1410 static void add_srcversion(struct buffer *b, struct module *mod) 1411 { 1412 if (mod->srcversion[0]) { 1413 buf_printf(b, "\n"); 1414 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1415 mod->srcversion); 1416 } 1417 } 1418 1419 static void write_if_changed(struct buffer *b, const char *fname) 1420 { 1421 char *tmp; 1422 FILE *file; 1423 struct stat st; 1424 1425 file = fopen(fname, "r"); 1426 if (!file) 1427 goto write; 1428 1429 if (fstat(fileno(file), &st) < 0) 1430 goto close_write; 1431 1432 if (st.st_size != b->pos) 1433 goto close_write; 1434 1435 tmp = NOFAIL(malloc(b->pos)); 1436 if (fread(tmp, 1, b->pos, file) != b->pos) 1437 goto free_write; 1438 1439 if (memcmp(tmp, b->p, b->pos) != 0) 1440 goto free_write; 1441 1442 free(tmp); 1443 fclose(file); 1444 return; 1445 1446 free_write: 1447 free(tmp); 1448 close_write: 1449 fclose(file); 1450 write: 1451 file = fopen(fname, "w"); 1452 if (!file) { 1453 perror(fname); 1454 exit(1); 1455 } 1456 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1457 perror(fname); 1458 exit(1); 1459 } 1460 fclose(file); 1461 } 1462 1463 /* parse Module.symvers file. line format: 1464 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] 1465 **/ 1466 static void read_dump(const char *fname, unsigned int kernel) 1467 { 1468 unsigned long size, pos = 0; 1469 void *file = grab_file(fname, &size); 1470 char *line; 1471 1472 if (!file) 1473 /* No symbol versions, silently ignore */ 1474 return; 1475 1476 while ((line = get_next_line(&pos, file, size))) { 1477 char *symname, *modname, *d, *export, *end; 1478 unsigned int crc; 1479 struct module *mod; 1480 struct symbol *s; 1481 1482 if (!(symname = strchr(line, '\t'))) 1483 goto fail; 1484 *symname++ = '\0'; 1485 if (!(modname = strchr(symname, '\t'))) 1486 goto fail; 1487 *modname++ = '\0'; 1488 if ((export = strchr(modname, '\t')) != NULL) 1489 *export++ = '\0'; 1490 if (export && ((end = strchr(export, '\t')) != NULL)) 1491 *end = '\0'; 1492 crc = strtoul(line, &d, 16); 1493 if (*symname == '\0' || *modname == '\0' || *d != '\0') 1494 goto fail; 1495 1496 if (!(mod = find_module(modname))) { 1497 if (is_vmlinux(modname)) { 1498 have_vmlinux = 1; 1499 } 1500 mod = new_module(NOFAIL(strdup(modname))); 1501 mod->skip = 1; 1502 } 1503 s = sym_add_exported(symname, mod, export_no(export)); 1504 s->kernel = kernel; 1505 s->preloaded = 1; 1506 sym_update_crc(symname, mod, crc, export_no(export)); 1507 } 1508 return; 1509 fail: 1510 fatal("parse error in symbol dump file\n"); 1511 } 1512 1513 /* For normal builds always dump all symbols. 1514 * For external modules only dump symbols 1515 * that are not read from kernel Module.symvers. 1516 **/ 1517 static int dump_sym(struct symbol *sym) 1518 { 1519 if (!external_module) 1520 return 1; 1521 if (sym->vmlinux || sym->kernel) 1522 return 0; 1523 return 1; 1524 } 1525 1526 static void write_dump(const char *fname) 1527 { 1528 struct buffer buf = { }; 1529 struct symbol *symbol; 1530 int n; 1531 1532 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { 1533 symbol = symbolhash[n]; 1534 while (symbol) { 1535 if (dump_sym(symbol)) 1536 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", 1537 symbol->crc, symbol->name, 1538 symbol->module->name, 1539 export_str(symbol->export)); 1540 symbol = symbol->next; 1541 } 1542 } 1543 write_if_changed(&buf, fname); 1544 } 1545 1546 int main(int argc, char **argv) 1547 { 1548 struct module *mod; 1549 struct buffer buf = { }; 1550 char fname[SZ]; 1551 char *kernel_read = NULL, *module_read = NULL; 1552 char *dump_write = NULL; 1553 int opt; 1554 int err; 1555 1556 while ((opt = getopt(argc, argv, "i:I:mo:aw")) != -1) { 1557 switch(opt) { 1558 case 'i': 1559 kernel_read = optarg; 1560 break; 1561 case 'I': 1562 module_read = optarg; 1563 external_module = 1; 1564 break; 1565 case 'm': 1566 modversions = 1; 1567 break; 1568 case 'o': 1569 dump_write = optarg; 1570 break; 1571 case 'a': 1572 all_versions = 1; 1573 break; 1574 case 'w': 1575 warn_unresolved = 1; 1576 break; 1577 default: 1578 exit(1); 1579 } 1580 } 1581 1582 if (kernel_read) 1583 read_dump(kernel_read, 1); 1584 if (module_read) 1585 read_dump(module_read, 0); 1586 1587 while (optind < argc) { 1588 read_symbols(argv[optind++]); 1589 } 1590 1591 for (mod = modules; mod; mod = mod->next) { 1592 if (mod->skip) 1593 continue; 1594 check_exports(mod); 1595 } 1596 1597 err = 0; 1598 1599 for (mod = modules; mod; mod = mod->next) { 1600 if (mod->skip) 1601 continue; 1602 1603 buf.pos = 0; 1604 1605 add_header(&buf, mod); 1606 err |= add_versions(&buf, mod); 1607 add_depends(&buf, mod, modules); 1608 add_moddevtable(&buf, mod); 1609 add_srcversion(&buf, mod); 1610 1611 sprintf(fname, "%s.mod.c", mod->name); 1612 write_if_changed(&buf, fname); 1613 } 1614 1615 if (dump_write) 1616 write_dump(dump_write); 1617 1618 return err; 1619 } 1620