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 * 586 * Pattern 0: 587 * Do not warn if funtion/data are marked with __init_refok/__initdata_refok. 588 * The pattern is identified by: 589 * fromsec = .text.init.refok | .data.init.refok 590 * 591 * Pattern 1: 592 * If a module parameter is declared __initdata and permissions=0 593 * then this is legal despite the warning generated. 594 * We cannot see value of permissions here, so just ignore 595 * this pattern. 596 * The pattern is identified by: 597 * tosec = .init.data 598 * fromsec = .data* 599 * atsym =__param* 600 * 601 * Pattern 2: 602 * Many drivers utilise a *driver container with references to 603 * add, remove, probe functions etc. 604 * These functions may often be marked __init and we do not want to 605 * warn here. 606 * the pattern is identified by: 607 * tosec = .init.text | .exit.text | .init.data 608 * fromsec = .data 609 * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one, *_console 610 * 611 * Pattern 3: 612 * Whitelist all references from .pci_fixup* section to .init.text 613 * This is part of the PCI init when built-in 614 * 615 * Pattern 4: 616 * Whitelist all refereces from .text.head to .init.data 617 * Whitelist all refereces from .text.head to .init.text 618 * 619 * Pattern 5: 620 * Some symbols belong to init section but still it is ok to reference 621 * these from non-init sections as these symbols don't have any memory 622 * allocated for them and symbol address and value are same. So even 623 * if init section is freed, its ok to reference those symbols. 624 * For ex. symbols marking the init section boundaries. 625 * This pattern is identified by 626 * refsymname = __init_begin, _sinittext, _einittext 627 * 628 * Pattern 7: 629 * Logos used in drivers/video/logo reside in __initdata but the 630 * funtion that references them are EXPORT_SYMBOL() so cannot be 631 * marker __init. So we whitelist them here. 632 * The pattern is: 633 * tosec = .init.data 634 * fromsec = .text* 635 * refsymname = logo_ 636 * 637 * Pattern 8: 638 * Symbols contained in .paravirtprobe may safely reference .init.text. 639 * The pattern is: 640 * tosec = .init.text 641 * fromsec = .paravirtprobe 642 * 643 * Pattern 10: 644 * ia64 has machvec table for each platform and 645 * powerpc has a machine desc table for each platform. 646 * It is mixture of function pointers of .init.text and .text. 647 * fromsec = .machvec | .machine.desc 648 **/ 649 static int secref_whitelist(const char *modname, const char *tosec, 650 const char *fromsec, const char *atsym, 651 const char *refsymname) 652 { 653 int f1 = 1, f2 = 1; 654 const char **s; 655 const char *pat2sym[] = { 656 "driver", 657 "_template", /* scsi uses *_template a lot */ 658 "_sht", /* scsi also used *_sht to some extent */ 659 "_ops", 660 "_probe", 661 "_probe_one", 662 "_console", 663 "apic_es7000", 664 NULL 665 }; 666 667 const char *pat3refsym[] = { 668 "__init_begin", 669 "_sinittext", 670 "_einittext", 671 NULL 672 }; 673 674 /* Check for pattern 0 */ 675 if ((strcmp(fromsec, ".text.init.refok") == 0) || 676 (strcmp(fromsec, ".data.init.refok") == 0)) 677 return 1; 678 679 /* Check for pattern 1 */ 680 if (strcmp(tosec, ".init.data") != 0) 681 f1 = 0; 682 if (strncmp(fromsec, ".data", strlen(".data")) != 0) 683 f1 = 0; 684 if (strncmp(atsym, "__param", strlen("__param")) != 0) 685 f1 = 0; 686 687 if (f1) 688 return f1; 689 690 /* Check for pattern 2 */ 691 if ((strcmp(tosec, ".init.text") != 0) && 692 (strcmp(tosec, ".exit.text") != 0) && 693 (strcmp(tosec, ".init.data") != 0)) 694 f2 = 0; 695 if (strcmp(fromsec, ".data") != 0) 696 f2 = 0; 697 698 for (s = pat2sym; *s; s++) 699 if (strrcmp(atsym, *s) == 0) 700 f1 = 1; 701 if (f1 && f2) 702 return 1; 703 704 /* Check for pattern 3 */ 705 if ((strncmp(fromsec, ".pci_fixup", strlen(".pci_fixup")) == 0) && 706 (strcmp(tosec, ".init.text") == 0)) 707 return 1; 708 709 /* Check for pattern 4 */ 710 if ((strcmp(fromsec, ".text.head") == 0) && 711 ((strcmp(tosec, ".init.data") == 0) || 712 (strcmp(tosec, ".init.text") == 0))) 713 return 1; 714 715 /* Check for pattern 5 */ 716 for (s = pat3refsym; *s; s++) 717 if (strcmp(refsymname, *s) == 0) 718 return 1; 719 720 /* Check for pattern 7 */ 721 if ((strcmp(tosec, ".init.data") == 0) && 722 (strncmp(fromsec, ".text", strlen(".text")) == 0) && 723 (strncmp(refsymname, "logo_", strlen("logo_")) == 0)) 724 return 1; 725 726 /* Check for pattern 8 */ 727 if ((strcmp(tosec, ".init.text") == 0) && 728 (strcmp(fromsec, ".paravirtprobe") == 0)) 729 return 1; 730 731 /* Check for pattern 10 */ 732 if ((strcmp(fromsec, ".machvec") == 0) || 733 (strcmp(fromsec, ".machine.desc") == 0)) 734 return 1; 735 736 return 0; 737 } 738 739 /** 740 * Find symbol based on relocation record info. 741 * In some cases the symbol supplied is a valid symbol so 742 * return refsym. If st_name != 0 we assume this is a valid symbol. 743 * In other cases the symbol needs to be looked up in the symbol table 744 * based on section and address. 745 * **/ 746 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr, 747 Elf_Sym *relsym) 748 { 749 Elf_Sym *sym; 750 751 if (relsym->st_name != 0) 752 return relsym; 753 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 754 if (sym->st_shndx != relsym->st_shndx) 755 continue; 756 if (sym->st_value == addr) 757 return sym; 758 } 759 return NULL; 760 } 761 762 static inline int is_arm_mapping_symbol(const char *str) 763 { 764 return str[0] == '$' && strchr("atd", str[1]) 765 && (str[2] == '\0' || str[2] == '.'); 766 } 767 768 /* 769 * If there's no name there, ignore it; likewise, ignore it if it's 770 * one of the magic symbols emitted used by current ARM tools. 771 * 772 * Otherwise if find_symbols_between() returns those symbols, they'll 773 * fail the whitelist tests and cause lots of false alarms ... fixable 774 * only by merging __exit and __init sections into __text, bloating 775 * the kernel (which is especially evil on embedded platforms). 776 */ 777 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 778 { 779 const char *name = elf->strtab + sym->st_name; 780 781 if (!name || !strlen(name)) 782 return 0; 783 return !is_arm_mapping_symbol(name); 784 } 785 786 /* 787 * Find symbols before or equal addr and after addr - in the section sec. 788 * If we find two symbols with equal offset prefer one with a valid name. 789 * The ELF format may have a better way to detect what type of symbol 790 * it is, but this works for now. 791 **/ 792 static void find_symbols_between(struct elf_info *elf, Elf_Addr addr, 793 const char *sec, 794 Elf_Sym **before, Elf_Sym **after) 795 { 796 Elf_Sym *sym; 797 Elf_Ehdr *hdr = elf->hdr; 798 Elf_Addr beforediff = ~0; 799 Elf_Addr afterdiff = ~0; 800 const char *secstrings = (void *)hdr + 801 elf->sechdrs[hdr->e_shstrndx].sh_offset; 802 803 *before = NULL; 804 *after = NULL; 805 806 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 807 const char *symsec; 808 809 if (sym->st_shndx >= SHN_LORESERVE) 810 continue; 811 symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name; 812 if (strcmp(symsec, sec) != 0) 813 continue; 814 if (!is_valid_name(elf, sym)) 815 continue; 816 if (sym->st_value <= addr) { 817 if ((addr - sym->st_value) < beforediff) { 818 beforediff = addr - sym->st_value; 819 *before = sym; 820 } 821 else if ((addr - sym->st_value) == beforediff) { 822 *before = sym; 823 } 824 } 825 else 826 { 827 if ((sym->st_value - addr) < afterdiff) { 828 afterdiff = sym->st_value - addr; 829 *after = sym; 830 } 831 else if ((sym->st_value - addr) == afterdiff) { 832 *after = sym; 833 } 834 } 835 } 836 } 837 838 /** 839 * Print a warning about a section mismatch. 840 * Try to find symbols near it so user can find it. 841 * Check whitelist before warning - it may be a false positive. 842 **/ 843 static void warn_sec_mismatch(const char *modname, const char *fromsec, 844 struct elf_info *elf, Elf_Sym *sym, Elf_Rela r) 845 { 846 const char *refsymname = ""; 847 Elf_Sym *before, *after; 848 Elf_Sym *refsym; 849 Elf_Ehdr *hdr = elf->hdr; 850 Elf_Shdr *sechdrs = elf->sechdrs; 851 const char *secstrings = (void *)hdr + 852 sechdrs[hdr->e_shstrndx].sh_offset; 853 const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name; 854 855 find_symbols_between(elf, r.r_offset, fromsec, &before, &after); 856 857 refsym = find_elf_symbol(elf, r.r_addend, sym); 858 if (refsym && strlen(elf->strtab + refsym->st_name)) 859 refsymname = elf->strtab + refsym->st_name; 860 861 /* check whitelist - we may ignore it */ 862 if (before && 863 secref_whitelist(modname, secname, fromsec, 864 elf->strtab + before->st_name, refsymname)) 865 return; 866 867 /* fromsec whitelist - without a valid 'before' 868 * powerpc has a GOT table in .got2 section */ 869 if (strcmp(fromsec, ".got2") == 0) 870 return; 871 872 if (before && after) { 873 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " 874 "(between '%s' and '%s')\n", 875 modname, fromsec, (unsigned long long)r.r_offset, 876 secname, refsymname, 877 elf->strtab + before->st_name, 878 elf->strtab + after->st_name); 879 } else if (before) { 880 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " 881 "(after '%s')\n", 882 modname, fromsec, (unsigned long long)r.r_offset, 883 secname, refsymname, 884 elf->strtab + before->st_name); 885 } else if (after) { 886 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " 887 "before '%s' (at offset -0x%llx)\n", 888 modname, fromsec, (unsigned long long)r.r_offset, 889 secname, refsymname, 890 elf->strtab + after->st_name); 891 } else { 892 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s\n", 893 modname, fromsec, (unsigned long long)r.r_offset, 894 secname, refsymname); 895 } 896 } 897 898 /** 899 * A module includes a number of sections that are discarded 900 * either when loaded or when used as built-in. 901 * For loaded modules all functions marked __init and all data 902 * marked __initdata will be discarded when the module has been intialized. 903 * Likewise for modules used built-in the sections marked __exit 904 * are discarded because __exit marked function are supposed to be called 905 * only when a moduel is unloaded which never happes for built-in modules. 906 * The check_sec_ref() function traverses all relocation records 907 * to find all references to a section that reference a section that will 908 * be discarded and warns about it. 909 **/ 910 static void check_sec_ref(struct module *mod, const char *modname, 911 struct elf_info *elf, 912 int section(const char*), 913 int section_ref_ok(const char *)) 914 { 915 int i; 916 Elf_Sym *sym; 917 Elf_Ehdr *hdr = elf->hdr; 918 Elf_Shdr *sechdrs = elf->sechdrs; 919 const char *secstrings = (void *)hdr + 920 sechdrs[hdr->e_shstrndx].sh_offset; 921 922 /* Walk through all sections */ 923 for (i = 0; i < hdr->e_shnum; i++) { 924 const char *name = secstrings + sechdrs[i].sh_name; 925 const char *secname; 926 Elf_Rela r; 927 unsigned int r_sym; 928 /* We want to process only relocation sections and not .init */ 929 if (sechdrs[i].sh_type == SHT_RELA) { 930 Elf_Rela *rela; 931 Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset; 932 Elf_Rela *stop = (void*)start + sechdrs[i].sh_size; 933 name += strlen(".rela"); 934 if (section_ref_ok(name)) 935 continue; 936 937 for (rela = start; rela < stop; rela++) { 938 r.r_offset = TO_NATIVE(rela->r_offset); 939 #if KERNEL_ELFCLASS == ELFCLASS64 940 if (hdr->e_machine == EM_MIPS) { 941 r_sym = ELF64_MIPS_R_SYM(rela->r_info); 942 r_sym = TO_NATIVE(r_sym); 943 } else { 944 r.r_info = TO_NATIVE(rela->r_info); 945 r_sym = ELF_R_SYM(r.r_info); 946 } 947 #else 948 r.r_info = TO_NATIVE(rela->r_info); 949 r_sym = ELF_R_SYM(r.r_info); 950 #endif 951 r.r_addend = TO_NATIVE(rela->r_addend); 952 sym = elf->symtab_start + r_sym; 953 /* Skip special sections */ 954 if (sym->st_shndx >= SHN_LORESERVE) 955 continue; 956 957 secname = secstrings + 958 sechdrs[sym->st_shndx].sh_name; 959 if (section(secname)) 960 warn_sec_mismatch(modname, name, 961 elf, sym, r); 962 } 963 } else if (sechdrs[i].sh_type == SHT_REL) { 964 Elf_Rel *rel; 965 Elf_Rel *start = (void *)hdr + sechdrs[i].sh_offset; 966 Elf_Rel *stop = (void*)start + sechdrs[i].sh_size; 967 name += strlen(".rel"); 968 if (section_ref_ok(name)) 969 continue; 970 971 for (rel = start; rel < stop; rel++) { 972 r.r_offset = TO_NATIVE(rel->r_offset); 973 #if KERNEL_ELFCLASS == ELFCLASS64 974 if (hdr->e_machine == EM_MIPS) { 975 r_sym = ELF64_MIPS_R_SYM(rel->r_info); 976 r_sym = TO_NATIVE(r_sym); 977 } else { 978 r.r_info = TO_NATIVE(rel->r_info); 979 r_sym = ELF_R_SYM(r.r_info); 980 } 981 #else 982 r.r_info = TO_NATIVE(rel->r_info); 983 r_sym = ELF_R_SYM(r.r_info); 984 #endif 985 r.r_addend = 0; 986 sym = elf->symtab_start + r_sym; 987 /* Skip special sections */ 988 if (sym->st_shndx >= SHN_LORESERVE) 989 continue; 990 991 secname = secstrings + 992 sechdrs[sym->st_shndx].sh_name; 993 if (section(secname)) 994 warn_sec_mismatch(modname, name, 995 elf, sym, r); 996 } 997 } 998 } 999 } 1000 1001 /** 1002 * Functions used only during module init is marked __init and is stored in 1003 * a .init.text section. Likewise data is marked __initdata and stored in 1004 * a .init.data section. 1005 * If this section is one of these sections return 1 1006 * See include/linux/init.h for the details 1007 **/ 1008 static int init_section(const char *name) 1009 { 1010 if (strcmp(name, ".init") == 0) 1011 return 1; 1012 if (strncmp(name, ".init.", strlen(".init.")) == 0) 1013 return 1; 1014 return 0; 1015 } 1016 1017 /** 1018 * Identify sections from which references to a .init section is OK. 1019 * 1020 * Unfortunately references to read only data that referenced .init 1021 * sections had to be excluded. Almost all of these are false 1022 * positives, they are created by gcc. The downside of excluding rodata 1023 * is that there really are some user references from rodata to 1024 * init code, e.g. drivers/video/vgacon.c: 1025 * 1026 * const struct consw vga_con = { 1027 * con_startup: vgacon_startup, 1028 * 1029 * where vgacon_startup is __init. If you want to wade through the false 1030 * positives, take out the check for rodata. 1031 **/ 1032 static int init_section_ref_ok(const char *name) 1033 { 1034 const char **s; 1035 /* Absolute section names */ 1036 const char *namelist1[] = { 1037 ".init", 1038 ".opd", /* see comment [OPD] at exit_section_ref_ok() */ 1039 ".toc1", /* used by ppc64 */ 1040 ".stab", 1041 ".data.rel.ro", /* used by parisc64 */ 1042 ".parainstructions", 1043 ".text.lock", 1044 "__bug_table", /* used by powerpc for BUG() */ 1045 ".pci_fixup_header", 1046 ".pci_fixup_final", 1047 ".pdr", 1048 "__param", 1049 "__ex_table", 1050 ".fixup", 1051 ".smp_locks", 1052 ".plt", /* seen on ARCH=um build on x86_64. Harmless */ 1053 "__ftr_fixup", /* powerpc cpu feature fixup */ 1054 "__fw_ftr_fixup", /* powerpc firmware feature fixup */ 1055 ".cranges", /* used by sh64 */ 1056 NULL 1057 }; 1058 /* Start of section names */ 1059 const char *namelist2[] = { 1060 ".init.", 1061 ".altinstructions", 1062 ".eh_frame", 1063 ".debug", 1064 ".parainstructions", 1065 ".rodata", 1066 NULL 1067 }; 1068 /* part of section name */ 1069 const char *namelist3 [] = { 1070 ".unwind", /* sample: IA_64.unwind.init.text */ 1071 NULL 1072 }; 1073 1074 for (s = namelist1; *s; s++) 1075 if (strcmp(*s, name) == 0) 1076 return 1; 1077 for (s = namelist2; *s; s++) 1078 if (strncmp(*s, name, strlen(*s)) == 0) 1079 return 1; 1080 for (s = namelist3; *s; s++) 1081 if (strstr(name, *s) != NULL) 1082 return 1; 1083 if (strrcmp(name, ".init") == 0) 1084 return 1; 1085 return 0; 1086 } 1087 1088 /* 1089 * Functions used only during module exit is marked __exit and is stored in 1090 * a .exit.text section. Likewise data is marked __exitdata and stored in 1091 * a .exit.data section. 1092 * If this section is one of these sections return 1 1093 * See include/linux/init.h for the details 1094 **/ 1095 static int exit_section(const char *name) 1096 { 1097 if (strcmp(name, ".exit.text") == 0) 1098 return 1; 1099 if (strcmp(name, ".exit.data") == 0) 1100 return 1; 1101 return 0; 1102 1103 } 1104 1105 /* 1106 * Identify sections from which references to a .exit section is OK. 1107 * 1108 * [OPD] Keith Ownes <kaos@sgi.com> commented: 1109 * For our future {in}sanity, add a comment that this is the ppc .opd 1110 * section, not the ia64 .opd section. 1111 * ia64 .opd should not point to discarded sections. 1112 * [.rodata] like for .init.text we ignore .rodata references -same reason 1113 **/ 1114 static int exit_section_ref_ok(const char *name) 1115 { 1116 const char **s; 1117 /* Absolute section names */ 1118 const char *namelist1[] = { 1119 ".exit.text", 1120 ".exit.data", 1121 ".init.text", 1122 ".rodata", 1123 ".opd", /* See comment [OPD] */ 1124 ".toc1", /* used by ppc64 */ 1125 ".altinstructions", 1126 ".pdr", 1127 "__bug_table", /* used by powerpc for BUG() */ 1128 ".exitcall.exit", 1129 ".eh_frame", 1130 ".parainstructions", 1131 ".stab", 1132 "__ex_table", 1133 ".fixup", 1134 ".smp_locks", 1135 ".plt", /* seen on ARCH=um build on x86_64. Harmless */ 1136 ".cranges", /* used by sh64 */ 1137 NULL 1138 }; 1139 /* Start of section names */ 1140 const char *namelist2[] = { 1141 ".debug", 1142 NULL 1143 }; 1144 /* part of section name */ 1145 const char *namelist3 [] = { 1146 ".unwind", /* Sample: IA_64.unwind.exit.text */ 1147 NULL 1148 }; 1149 1150 for (s = namelist1; *s; s++) 1151 if (strcmp(*s, name) == 0) 1152 return 1; 1153 for (s = namelist2; *s; s++) 1154 if (strncmp(*s, name, strlen(*s)) == 0) 1155 return 1; 1156 for (s = namelist3; *s; s++) 1157 if (strstr(name, *s) != NULL) 1158 return 1; 1159 return 0; 1160 } 1161 1162 static void read_symbols(char *modname) 1163 { 1164 const char *symname; 1165 char *version; 1166 char *license; 1167 struct module *mod; 1168 struct elf_info info = { }; 1169 Elf_Sym *sym; 1170 1171 if (!parse_elf(&info, modname)) 1172 return; 1173 1174 mod = new_module(modname); 1175 1176 /* When there's no vmlinux, don't print warnings about 1177 * unresolved symbols (since there'll be too many ;) */ 1178 if (is_vmlinux(modname)) { 1179 have_vmlinux = 1; 1180 mod->skip = 1; 1181 } 1182 1183 license = get_modinfo(info.modinfo, info.modinfo_len, "license"); 1184 while (license) { 1185 if (license_is_gpl_compatible(license)) 1186 mod->gpl_compatible = 1; 1187 else { 1188 mod->gpl_compatible = 0; 1189 break; 1190 } 1191 license = get_next_modinfo(info.modinfo, info.modinfo_len, 1192 "license", license); 1193 } 1194 1195 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1196 symname = info.strtab + sym->st_name; 1197 1198 handle_modversions(mod, &info, sym, symname); 1199 handle_moddevtable(mod, &info, sym, symname); 1200 } 1201 check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok); 1202 check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok); 1203 1204 version = get_modinfo(info.modinfo, info.modinfo_len, "version"); 1205 if (version) 1206 maybe_frob_rcs_version(modname, version, info.modinfo, 1207 version - (char *)info.hdr); 1208 if (version || (all_versions && !is_vmlinux(modname))) 1209 get_src_version(modname, mod->srcversion, 1210 sizeof(mod->srcversion)-1); 1211 1212 parse_elf_finish(&info); 1213 1214 /* Our trick to get versioning for struct_module - it's 1215 * never passed as an argument to an exported function, so 1216 * the automatic versioning doesn't pick it up, but it's really 1217 * important anyhow */ 1218 if (modversions) 1219 mod->unres = alloc_symbol("struct_module", 0, mod->unres); 1220 } 1221 1222 #define SZ 500 1223 1224 /* We first write the generated file into memory using the 1225 * following helper, then compare to the file on disk and 1226 * only update the later if anything changed */ 1227 1228 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1229 const char *fmt, ...) 1230 { 1231 char tmp[SZ]; 1232 int len; 1233 va_list ap; 1234 1235 va_start(ap, fmt); 1236 len = vsnprintf(tmp, SZ, fmt, ap); 1237 buf_write(buf, tmp, len); 1238 va_end(ap); 1239 } 1240 1241 void buf_write(struct buffer *buf, const char *s, int len) 1242 { 1243 if (buf->size - buf->pos < len) { 1244 buf->size += len + SZ; 1245 buf->p = realloc(buf->p, buf->size); 1246 } 1247 strncpy(buf->p + buf->pos, s, len); 1248 buf->pos += len; 1249 } 1250 1251 static void check_for_gpl_usage(enum export exp, const char *m, const char *s) 1252 { 1253 const char *e = is_vmlinux(m) ?"":".ko"; 1254 1255 switch (exp) { 1256 case export_gpl: 1257 fatal("modpost: GPL-incompatible module %s%s " 1258 "uses GPL-only symbol '%s'\n", m, e, s); 1259 break; 1260 case export_unused_gpl: 1261 fatal("modpost: GPL-incompatible module %s%s " 1262 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); 1263 break; 1264 case export_gpl_future: 1265 warn("modpost: GPL-incompatible module %s%s " 1266 "uses future GPL-only symbol '%s'\n", m, e, s); 1267 break; 1268 case export_plain: 1269 case export_unused: 1270 case export_unknown: 1271 /* ignore */ 1272 break; 1273 } 1274 } 1275 1276 static void check_for_unused(enum export exp, const char* m, const char* s) 1277 { 1278 const char *e = is_vmlinux(m) ?"":".ko"; 1279 1280 switch (exp) { 1281 case export_unused: 1282 case export_unused_gpl: 1283 warn("modpost: module %s%s " 1284 "uses symbol '%s' marked UNUSED\n", m, e, s); 1285 break; 1286 default: 1287 /* ignore */ 1288 break; 1289 } 1290 } 1291 1292 static void check_exports(struct module *mod) 1293 { 1294 struct symbol *s, *exp; 1295 1296 for (s = mod->unres; s; s = s->next) { 1297 const char *basename; 1298 exp = find_symbol(s->name); 1299 if (!exp || exp->module == mod) 1300 continue; 1301 basename = strrchr(mod->name, '/'); 1302 if (basename) 1303 basename++; 1304 else 1305 basename = mod->name; 1306 if (!mod->gpl_compatible) 1307 check_for_gpl_usage(exp->export, basename, exp->name); 1308 check_for_unused(exp->export, basename, exp->name); 1309 } 1310 } 1311 1312 /** 1313 * Header for the generated file 1314 **/ 1315 static void add_header(struct buffer *b, struct module *mod) 1316 { 1317 buf_printf(b, "#include <linux/module.h>\n"); 1318 buf_printf(b, "#include <linux/vermagic.h>\n"); 1319 buf_printf(b, "#include <linux/compiler.h>\n"); 1320 buf_printf(b, "\n"); 1321 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1322 buf_printf(b, "\n"); 1323 buf_printf(b, "struct module __this_module\n"); 1324 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); 1325 buf_printf(b, " .name = KBUILD_MODNAME,\n"); 1326 if (mod->has_init) 1327 buf_printf(b, " .init = init_module,\n"); 1328 if (mod->has_cleanup) 1329 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1330 " .exit = cleanup_module,\n" 1331 "#endif\n"); 1332 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n"); 1333 buf_printf(b, "};\n"); 1334 } 1335 1336 /** 1337 * Record CRCs for unresolved symbols 1338 **/ 1339 static int add_versions(struct buffer *b, struct module *mod) 1340 { 1341 struct symbol *s, *exp; 1342 int err = 0; 1343 1344 for (s = mod->unres; s; s = s->next) { 1345 exp = find_symbol(s->name); 1346 if (!exp || exp->module == mod) { 1347 if (have_vmlinux && !s->weak) { 1348 if (warn_unresolved) { 1349 warn("\"%s\" [%s.ko] undefined!\n", 1350 s->name, mod->name); 1351 } else { 1352 merror("\"%s\" [%s.ko] undefined!\n", 1353 s->name, mod->name); 1354 err = 1; 1355 } 1356 } 1357 continue; 1358 } 1359 s->module = exp->module; 1360 s->crc_valid = exp->crc_valid; 1361 s->crc = exp->crc; 1362 } 1363 1364 if (!modversions) 1365 return err; 1366 1367 buf_printf(b, "\n"); 1368 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1369 buf_printf(b, "__attribute_used__\n"); 1370 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); 1371 1372 for (s = mod->unres; s; s = s->next) { 1373 if (!s->module) { 1374 continue; 1375 } 1376 if (!s->crc_valid) { 1377 warn("\"%s\" [%s.ko] has no CRC!\n", 1378 s->name, mod->name); 1379 continue; 1380 } 1381 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); 1382 } 1383 1384 buf_printf(b, "};\n"); 1385 1386 return err; 1387 } 1388 1389 static void add_depends(struct buffer *b, struct module *mod, 1390 struct module *modules) 1391 { 1392 struct symbol *s; 1393 struct module *m; 1394 int first = 1; 1395 1396 for (m = modules; m; m = m->next) { 1397 m->seen = is_vmlinux(m->name); 1398 } 1399 1400 buf_printf(b, "\n"); 1401 buf_printf(b, "static const char __module_depends[]\n"); 1402 buf_printf(b, "__attribute_used__\n"); 1403 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); 1404 buf_printf(b, "\"depends="); 1405 for (s = mod->unres; s; s = s->next) { 1406 const char *p; 1407 if (!s->module) 1408 continue; 1409 1410 if (s->module->seen) 1411 continue; 1412 1413 s->module->seen = 1; 1414 if ((p = strrchr(s->module->name, '/')) != NULL) 1415 p++; 1416 else 1417 p = s->module->name; 1418 buf_printf(b, "%s%s", first ? "" : ",", p); 1419 first = 0; 1420 } 1421 buf_printf(b, "\";\n"); 1422 } 1423 1424 static void add_srcversion(struct buffer *b, struct module *mod) 1425 { 1426 if (mod->srcversion[0]) { 1427 buf_printf(b, "\n"); 1428 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1429 mod->srcversion); 1430 } 1431 } 1432 1433 static void write_if_changed(struct buffer *b, const char *fname) 1434 { 1435 char *tmp; 1436 FILE *file; 1437 struct stat st; 1438 1439 file = fopen(fname, "r"); 1440 if (!file) 1441 goto write; 1442 1443 if (fstat(fileno(file), &st) < 0) 1444 goto close_write; 1445 1446 if (st.st_size != b->pos) 1447 goto close_write; 1448 1449 tmp = NOFAIL(malloc(b->pos)); 1450 if (fread(tmp, 1, b->pos, file) != b->pos) 1451 goto free_write; 1452 1453 if (memcmp(tmp, b->p, b->pos) != 0) 1454 goto free_write; 1455 1456 free(tmp); 1457 fclose(file); 1458 return; 1459 1460 free_write: 1461 free(tmp); 1462 close_write: 1463 fclose(file); 1464 write: 1465 file = fopen(fname, "w"); 1466 if (!file) { 1467 perror(fname); 1468 exit(1); 1469 } 1470 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1471 perror(fname); 1472 exit(1); 1473 } 1474 fclose(file); 1475 } 1476 1477 /* parse Module.symvers file. line format: 1478 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] 1479 **/ 1480 static void read_dump(const char *fname, unsigned int kernel) 1481 { 1482 unsigned long size, pos = 0; 1483 void *file = grab_file(fname, &size); 1484 char *line; 1485 1486 if (!file) 1487 /* No symbol versions, silently ignore */ 1488 return; 1489 1490 while ((line = get_next_line(&pos, file, size))) { 1491 char *symname, *modname, *d, *export, *end; 1492 unsigned int crc; 1493 struct module *mod; 1494 struct symbol *s; 1495 1496 if (!(symname = strchr(line, '\t'))) 1497 goto fail; 1498 *symname++ = '\0'; 1499 if (!(modname = strchr(symname, '\t'))) 1500 goto fail; 1501 *modname++ = '\0'; 1502 if ((export = strchr(modname, '\t')) != NULL) 1503 *export++ = '\0'; 1504 if (export && ((end = strchr(export, '\t')) != NULL)) 1505 *end = '\0'; 1506 crc = strtoul(line, &d, 16); 1507 if (*symname == '\0' || *modname == '\0' || *d != '\0') 1508 goto fail; 1509 1510 if (!(mod = find_module(modname))) { 1511 if (is_vmlinux(modname)) { 1512 have_vmlinux = 1; 1513 } 1514 mod = new_module(NOFAIL(strdup(modname))); 1515 mod->skip = 1; 1516 } 1517 s = sym_add_exported(symname, mod, export_no(export)); 1518 s->kernel = kernel; 1519 s->preloaded = 1; 1520 sym_update_crc(symname, mod, crc, export_no(export)); 1521 } 1522 return; 1523 fail: 1524 fatal("parse error in symbol dump file\n"); 1525 } 1526 1527 /* For normal builds always dump all symbols. 1528 * For external modules only dump symbols 1529 * that are not read from kernel Module.symvers. 1530 **/ 1531 static int dump_sym(struct symbol *sym) 1532 { 1533 if (!external_module) 1534 return 1; 1535 if (sym->vmlinux || sym->kernel) 1536 return 0; 1537 return 1; 1538 } 1539 1540 static void write_dump(const char *fname) 1541 { 1542 struct buffer buf = { }; 1543 struct symbol *symbol; 1544 int n; 1545 1546 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { 1547 symbol = symbolhash[n]; 1548 while (symbol) { 1549 if (dump_sym(symbol)) 1550 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", 1551 symbol->crc, symbol->name, 1552 symbol->module->name, 1553 export_str(symbol->export)); 1554 symbol = symbol->next; 1555 } 1556 } 1557 write_if_changed(&buf, fname); 1558 } 1559 1560 int main(int argc, char **argv) 1561 { 1562 struct module *mod; 1563 struct buffer buf = { }; 1564 char fname[SZ]; 1565 char *kernel_read = NULL, *module_read = NULL; 1566 char *dump_write = NULL; 1567 int opt; 1568 int err; 1569 1570 while ((opt = getopt(argc, argv, "i:I:mo:aw")) != -1) { 1571 switch(opt) { 1572 case 'i': 1573 kernel_read = optarg; 1574 break; 1575 case 'I': 1576 module_read = optarg; 1577 external_module = 1; 1578 break; 1579 case 'm': 1580 modversions = 1; 1581 break; 1582 case 'o': 1583 dump_write = optarg; 1584 break; 1585 case 'a': 1586 all_versions = 1; 1587 break; 1588 case 'w': 1589 warn_unresolved = 1; 1590 break; 1591 default: 1592 exit(1); 1593 } 1594 } 1595 1596 if (kernel_read) 1597 read_dump(kernel_read, 1); 1598 if (module_read) 1599 read_dump(module_read, 0); 1600 1601 while (optind < argc) { 1602 read_symbols(argv[optind++]); 1603 } 1604 1605 for (mod = modules; mod; mod = mod->next) { 1606 if (mod->skip) 1607 continue; 1608 check_exports(mod); 1609 } 1610 1611 err = 0; 1612 1613 for (mod = modules; mod; mod = mod->next) { 1614 if (mod->skip) 1615 continue; 1616 1617 buf.pos = 0; 1618 1619 add_header(&buf, mod); 1620 err |= add_versions(&buf, mod); 1621 add_depends(&buf, mod, modules); 1622 add_moddevtable(&buf, mod); 1623 add_srcversion(&buf, mod); 1624 1625 sprintf(fname, "%s.mod.c", mod->name); 1626 write_if_changed(&buf, fname); 1627 } 1628 1629 if (dump_write) 1630 write_dump(dump_write); 1631 1632 return err; 1633 } 1634