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 /* Warn about section mismatch in vmlinux if set to 1 */ 27 static int vmlinux_section_warnings = 1; 28 /* Only warn about unresolved symbols */ 29 static int warn_unresolved = 0; 30 /* How a symbol is exported */ 31 enum export { 32 export_plain, export_unused, export_gpl, 33 export_unused_gpl, export_gpl_future, export_unknown 34 }; 35 36 void fatal(const char *fmt, ...) 37 { 38 va_list arglist; 39 40 fprintf(stderr, "FATAL: "); 41 42 va_start(arglist, fmt); 43 vfprintf(stderr, fmt, arglist); 44 va_end(arglist); 45 46 exit(1); 47 } 48 49 void warn(const char *fmt, ...) 50 { 51 va_list arglist; 52 53 fprintf(stderr, "WARNING: "); 54 55 va_start(arglist, fmt); 56 vfprintf(stderr, fmt, arglist); 57 va_end(arglist); 58 } 59 60 void merror(const char *fmt, ...) 61 { 62 va_list arglist; 63 64 fprintf(stderr, "ERROR: "); 65 66 va_start(arglist, fmt); 67 vfprintf(stderr, fmt, arglist); 68 va_end(arglist); 69 } 70 71 static int is_vmlinux(const char *modname) 72 { 73 const char *myname; 74 75 if ((myname = strrchr(modname, '/'))) 76 myname++; 77 else 78 myname = modname; 79 80 return (strcmp(myname, "vmlinux") == 0) || 81 (strcmp(myname, "vmlinux.o") == 0); 82 } 83 84 void *do_nofail(void *ptr, const char *expr) 85 { 86 if (!ptr) { 87 fatal("modpost: Memory allocation failure: %s.\n", expr); 88 } 89 return ptr; 90 } 91 92 /* A list of all modules we processed */ 93 94 static struct module *modules; 95 96 static struct module *find_module(char *modname) 97 { 98 struct module *mod; 99 100 for (mod = modules; mod; mod = mod->next) 101 if (strcmp(mod->name, modname) == 0) 102 break; 103 return mod; 104 } 105 106 static struct module *new_module(char *modname) 107 { 108 struct module *mod; 109 char *p, *s; 110 111 mod = NOFAIL(malloc(sizeof(*mod))); 112 memset(mod, 0, sizeof(*mod)); 113 p = NOFAIL(strdup(modname)); 114 115 /* strip trailing .o */ 116 if ((s = strrchr(p, '.')) != NULL) 117 if (strcmp(s, ".o") == 0) 118 *s = '\0'; 119 120 /* add to list */ 121 mod->name = p; 122 mod->gpl_compatible = -1; 123 mod->next = modules; 124 modules = mod; 125 126 return mod; 127 } 128 129 /* A hash of all exported symbols, 130 * struct symbol is also used for lists of unresolved symbols */ 131 132 #define SYMBOL_HASH_SIZE 1024 133 134 struct symbol { 135 struct symbol *next; 136 struct module *module; 137 unsigned int crc; 138 int crc_valid; 139 unsigned int weak:1; 140 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */ 141 unsigned int kernel:1; /* 1 if symbol is from kernel 142 * (only for external modules) **/ 143 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */ 144 enum export export; /* Type of export */ 145 char name[0]; 146 }; 147 148 static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 149 150 /* This is based on the hash agorithm from gdbm, via tdb */ 151 static inline unsigned int tdb_hash(const char *name) 152 { 153 unsigned value; /* Used to compute the hash value. */ 154 unsigned i; /* Used to cycle through random values. */ 155 156 /* Set the initial value from the key size. */ 157 for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++) 158 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 159 160 return (1103515243 * value + 12345); 161 } 162 163 /** 164 * Allocate a new symbols for use in the hash of exported symbols or 165 * the list of unresolved symbols per module 166 **/ 167 static struct symbol *alloc_symbol(const char *name, unsigned int weak, 168 struct symbol *next) 169 { 170 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 171 172 memset(s, 0, sizeof(*s)); 173 strcpy(s->name, name); 174 s->weak = weak; 175 s->next = next; 176 return s; 177 } 178 179 /* For the hash of exported symbols */ 180 static struct symbol *new_symbol(const char *name, struct module *module, 181 enum export export) 182 { 183 unsigned int hash; 184 struct symbol *new; 185 186 hash = tdb_hash(name) % SYMBOL_HASH_SIZE; 187 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]); 188 new->module = module; 189 new->export = export; 190 return new; 191 } 192 193 static struct symbol *find_symbol(const char *name) 194 { 195 struct symbol *s; 196 197 /* For our purposes, .foo matches foo. PPC64 needs this. */ 198 if (name[0] == '.') 199 name++; 200 201 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s=s->next) { 202 if (strcmp(s->name, name) == 0) 203 return s; 204 } 205 return NULL; 206 } 207 208 static struct { 209 const char *str; 210 enum export export; 211 } export_list[] = { 212 { .str = "EXPORT_SYMBOL", .export = export_plain }, 213 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused }, 214 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl }, 215 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl }, 216 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future }, 217 { .str = "(unknown)", .export = export_unknown }, 218 }; 219 220 221 static const char *export_str(enum export ex) 222 { 223 return export_list[ex].str; 224 } 225 226 static enum export export_no(const char * s) 227 { 228 int i; 229 if (!s) 230 return export_unknown; 231 for (i = 0; export_list[i].export != export_unknown; i++) { 232 if (strcmp(export_list[i].str, s) == 0) 233 return export_list[i].export; 234 } 235 return export_unknown; 236 } 237 238 static enum export export_from_sec(struct elf_info *elf, Elf_Section sec) 239 { 240 if (sec == elf->export_sec) 241 return export_plain; 242 else if (sec == elf->export_unused_sec) 243 return export_unused; 244 else if (sec == elf->export_gpl_sec) 245 return export_gpl; 246 else if (sec == elf->export_unused_gpl_sec) 247 return export_unused_gpl; 248 else if (sec == elf->export_gpl_future_sec) 249 return export_gpl_future; 250 else 251 return export_unknown; 252 } 253 254 /** 255 * Add an exported symbol - it may have already been added without a 256 * CRC, in this case just update the CRC 257 **/ 258 static struct symbol *sym_add_exported(const char *name, struct module *mod, 259 enum export export) 260 { 261 struct symbol *s = find_symbol(name); 262 263 if (!s) { 264 s = new_symbol(name, mod, export); 265 } else { 266 if (!s->preloaded) { 267 warn("%s: '%s' exported twice. Previous export " 268 "was in %s%s\n", mod->name, name, 269 s->module->name, 270 is_vmlinux(s->module->name) ?"":".ko"); 271 } 272 } 273 s->preloaded = 0; 274 s->vmlinux = is_vmlinux(mod->name); 275 s->kernel = 0; 276 s->export = export; 277 return s; 278 } 279 280 static void sym_update_crc(const char *name, struct module *mod, 281 unsigned int crc, enum export export) 282 { 283 struct symbol *s = find_symbol(name); 284 285 if (!s) 286 s = new_symbol(name, mod, export); 287 s->crc = crc; 288 s->crc_valid = 1; 289 } 290 291 void *grab_file(const char *filename, unsigned long *size) 292 { 293 struct stat st; 294 void *map; 295 int fd; 296 297 fd = open(filename, O_RDONLY); 298 if (fd < 0 || fstat(fd, &st) != 0) 299 return NULL; 300 301 *size = st.st_size; 302 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 303 close(fd); 304 305 if (map == MAP_FAILED) 306 return NULL; 307 return map; 308 } 309 310 /** 311 * Return a copy of the next line in a mmap'ed file. 312 * spaces in the beginning of the line is trimmed away. 313 * Return a pointer to a static buffer. 314 **/ 315 char* get_next_line(unsigned long *pos, void *file, unsigned long size) 316 { 317 static char line[4096]; 318 int skip = 1; 319 size_t len = 0; 320 signed char *p = (signed char *)file + *pos; 321 char *s = line; 322 323 for (; *pos < size ; (*pos)++) 324 { 325 if (skip && isspace(*p)) { 326 p++; 327 continue; 328 } 329 skip = 0; 330 if (*p != '\n' && (*pos < size)) { 331 len++; 332 *s++ = *p++; 333 if (len > 4095) 334 break; /* Too long, stop */ 335 } else { 336 /* End of string */ 337 *s = '\0'; 338 return line; 339 } 340 } 341 /* End of buffer */ 342 return NULL; 343 } 344 345 void release_file(void *file, unsigned long size) 346 { 347 munmap(file, size); 348 } 349 350 static int parse_elf(struct elf_info *info, const char *filename) 351 { 352 unsigned int i; 353 Elf_Ehdr *hdr; 354 Elf_Shdr *sechdrs; 355 Elf_Sym *sym; 356 357 hdr = grab_file(filename, &info->size); 358 if (!hdr) { 359 perror(filename); 360 exit(1); 361 } 362 info->hdr = hdr; 363 if (info->size < sizeof(*hdr)) { 364 /* file too small, assume this is an empty .o file */ 365 return 0; 366 } 367 /* Is this a valid ELF file? */ 368 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 369 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 370 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 371 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 372 /* Not an ELF file - silently ignore it */ 373 return 0; 374 } 375 /* Fix endianness in ELF header */ 376 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 377 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 378 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 379 hdr->e_machine = TO_NATIVE(hdr->e_machine); 380 hdr->e_type = TO_NATIVE(hdr->e_type); 381 sechdrs = (void *)hdr + hdr->e_shoff; 382 info->sechdrs = sechdrs; 383 384 /* Fix endianness in section headers */ 385 for (i = 0; i < hdr->e_shnum; i++) { 386 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 387 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 388 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 389 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 390 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 391 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 392 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 393 } 394 /* Find symbol table. */ 395 for (i = 1; i < hdr->e_shnum; i++) { 396 const char *secstrings 397 = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; 398 const char *secname; 399 400 if (sechdrs[i].sh_offset > info->size) { 401 fatal("%s is truncated. sechdrs[i].sh_offset=%u > sizeof(*hrd)=%ul\n", filename, (unsigned int)sechdrs[i].sh_offset, sizeof(*hdr)); 402 return 0; 403 } 404 secname = secstrings + sechdrs[i].sh_name; 405 if (strcmp(secname, ".modinfo") == 0) { 406 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 407 info->modinfo_len = sechdrs[i].sh_size; 408 } else if (strcmp(secname, "__ksymtab") == 0) 409 info->export_sec = i; 410 else if (strcmp(secname, "__ksymtab_unused") == 0) 411 info->export_unused_sec = i; 412 else if (strcmp(secname, "__ksymtab_gpl") == 0) 413 info->export_gpl_sec = i; 414 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0) 415 info->export_unused_gpl_sec = i; 416 else if (strcmp(secname, "__ksymtab_gpl_future") == 0) 417 info->export_gpl_future_sec = i; 418 419 if (sechdrs[i].sh_type != SHT_SYMTAB) 420 continue; 421 422 info->symtab_start = (void *)hdr + sechdrs[i].sh_offset; 423 info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset 424 + sechdrs[i].sh_size; 425 info->strtab = (void *)hdr + 426 sechdrs[sechdrs[i].sh_link].sh_offset; 427 } 428 if (!info->symtab_start) { 429 fatal("%s has no symtab?\n", filename); 430 } 431 /* Fix endianness in symbols */ 432 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 433 sym->st_shndx = TO_NATIVE(sym->st_shndx); 434 sym->st_name = TO_NATIVE(sym->st_name); 435 sym->st_value = TO_NATIVE(sym->st_value); 436 sym->st_size = TO_NATIVE(sym->st_size); 437 } 438 return 1; 439 } 440 441 static void parse_elf_finish(struct elf_info *info) 442 { 443 release_file(info->hdr, info->size); 444 } 445 446 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_" 447 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_" 448 449 static void handle_modversions(struct module *mod, struct elf_info *info, 450 Elf_Sym *sym, const char *symname) 451 { 452 unsigned int crc; 453 enum export export = export_from_sec(info, sym->st_shndx); 454 455 switch (sym->st_shndx) { 456 case SHN_COMMON: 457 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 458 break; 459 case SHN_ABS: 460 /* CRC'd symbol */ 461 if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { 462 crc = (unsigned int) sym->st_value; 463 sym_update_crc(symname + strlen(CRC_PFX), mod, crc, 464 export); 465 } 466 break; 467 case SHN_UNDEF: 468 /* undefined symbol */ 469 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 470 ELF_ST_BIND(sym->st_info) != STB_WEAK) 471 break; 472 /* ignore global offset table */ 473 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 474 break; 475 /* ignore __this_module, it will be resolved shortly */ 476 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0) 477 break; 478 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */ 479 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER) 480 /* add compatibility with older glibc */ 481 #ifndef STT_SPARC_REGISTER 482 #define STT_SPARC_REGISTER STT_REGISTER 483 #endif 484 if (info->hdr->e_machine == EM_SPARC || 485 info->hdr->e_machine == EM_SPARCV9) { 486 /* Ignore register directives. */ 487 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 488 break; 489 if (symname[0] == '.') { 490 char *munged = strdup(symname); 491 munged[0] = '_'; 492 munged[1] = toupper(munged[1]); 493 symname = munged; 494 } 495 } 496 #endif 497 498 if (memcmp(symname, MODULE_SYMBOL_PREFIX, 499 strlen(MODULE_SYMBOL_PREFIX)) == 0) 500 mod->unres = alloc_symbol(symname + 501 strlen(MODULE_SYMBOL_PREFIX), 502 ELF_ST_BIND(sym->st_info) == STB_WEAK, 503 mod->unres); 504 break; 505 default: 506 /* All exported symbols */ 507 if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) { 508 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod, 509 export); 510 } 511 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0) 512 mod->has_init = 1; 513 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0) 514 mod->has_cleanup = 1; 515 break; 516 } 517 } 518 519 /** 520 * Parse tag=value strings from .modinfo section 521 **/ 522 static char *next_string(char *string, unsigned long *secsize) 523 { 524 /* Skip non-zero chars */ 525 while (string[0]) { 526 string++; 527 if ((*secsize)-- <= 1) 528 return NULL; 529 } 530 531 /* Skip any zero padding. */ 532 while (!string[0]) { 533 string++; 534 if ((*secsize)-- <= 1) 535 return NULL; 536 } 537 return string; 538 } 539 540 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len, 541 const char *tag, char *info) 542 { 543 char *p; 544 unsigned int taglen = strlen(tag); 545 unsigned long size = modinfo_len; 546 547 if (info) { 548 size -= info - (char *)modinfo; 549 modinfo = next_string(info, &size); 550 } 551 552 for (p = modinfo; p; p = next_string(p, &size)) { 553 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 554 return p + taglen + 1; 555 } 556 return NULL; 557 } 558 559 static char *get_modinfo(void *modinfo, unsigned long modinfo_len, 560 const char *tag) 561 562 { 563 return get_next_modinfo(modinfo, modinfo_len, tag, NULL); 564 } 565 566 /** 567 * Test if string s ends in string sub 568 * return 0 if match 569 **/ 570 static int strrcmp(const char *s, const char *sub) 571 { 572 int slen, sublen; 573 574 if (!s || !sub) 575 return 1; 576 577 slen = strlen(s); 578 sublen = strlen(sub); 579 580 if ((slen == 0) || (sublen == 0)) 581 return 1; 582 583 if (sublen > slen) 584 return 1; 585 586 return memcmp(s + slen - sublen, sub, sublen); 587 } 588 589 /* 590 * Functions used only during module init is marked __init and is stored in 591 * a .init.text section. Likewise data is marked __initdata and stored in 592 * a .init.data section. 593 * If this section is one of these sections return 1 594 * See include/linux/init.h for the details 595 */ 596 static int init_section(const char *name) 597 { 598 if (strcmp(name, ".init") == 0) 599 return 1; 600 if (strncmp(name, ".init.", strlen(".init.")) == 0) 601 return 1; 602 return 0; 603 } 604 605 /* 606 * Functions used only during module exit is marked __exit and is stored in 607 * a .exit.text section. Likewise data is marked __exitdata and stored in 608 * a .exit.data section. 609 * If this section is one of these sections return 1 610 * See include/linux/init.h for the details 611 **/ 612 static int exit_section(const char *name) 613 { 614 if (strcmp(name, ".exit.text") == 0) 615 return 1; 616 if (strcmp(name, ".exit.data") == 0) 617 return 1; 618 return 0; 619 620 } 621 622 /* 623 * Data sections are named like this: 624 * .data | .data.rel | .data.rel.* 625 * Return 1 if the specified section is a data section 626 */ 627 static int data_section(const char *name) 628 { 629 if ((strcmp(name, ".data") == 0) || 630 (strcmp(name, ".data.rel") == 0) || 631 (strncmp(name, ".data.rel.", strlen(".data.rel.")) == 0)) 632 return 1; 633 else 634 return 0; 635 } 636 637 /** 638 * Whitelist to allow certain references to pass with no warning. 639 * 640 * Pattern 0: 641 * Do not warn if funtion/data are marked with __init_refok/__initdata_refok. 642 * The pattern is identified by: 643 * fromsec = .text.init.refok* | .data.init.refok* 644 * 645 * Pattern 1: 646 * If a module parameter is declared __initdata and permissions=0 647 * then this is legal despite the warning generated. 648 * We cannot see value of permissions here, so just ignore 649 * this pattern. 650 * The pattern is identified by: 651 * tosec = .init.data 652 * fromsec = .data* 653 * atsym =__param* 654 * 655 * Pattern 2: 656 * Many drivers utilise a *driver container with references to 657 * add, remove, probe functions etc. 658 * These functions may often be marked __init and we do not want to 659 * warn here. 660 * the pattern is identified by: 661 * tosec = init or exit section 662 * fromsec = data section 663 * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one, *_console, *_timer 664 * 665 * Pattern 3: 666 * Whitelist all refereces from .text.head to .init.data 667 * Whitelist all refereces from .text.head to .init.text 668 * 669 * Pattern 4: 670 * Some symbols belong to init section but still it is ok to reference 671 * these from non-init sections as these symbols don't have any memory 672 * allocated for them and symbol address and value are same. So even 673 * if init section is freed, its ok to reference those symbols. 674 * For ex. symbols marking the init section boundaries. 675 * This pattern is identified by 676 * refsymname = __init_begin, _sinittext, _einittext 677 * 678 * Pattern 5: 679 * Xtensa uses literal sections for constants that are accessed PC-relative. 680 * Literal sections may safely reference their text sections. 681 * (Note that the name for the literal section omits any trailing '.text') 682 * tosec = <section>[.text] 683 * fromsec = <section>.literal 684 **/ 685 static int secref_whitelist(const char *modname, const char *tosec, 686 const char *fromsec, const char *atsym, 687 const char *refsymname) 688 { 689 int len; 690 const char **s; 691 const char *pat2sym[] = { 692 "driver", 693 "_template", /* scsi uses *_template a lot */ 694 "_timer", /* arm uses ops structures named _timer a lot */ 695 "_sht", /* scsi also used *_sht to some extent */ 696 "_ops", 697 "_probe", 698 "_probe_one", 699 "_console", 700 NULL 701 }; 702 703 const char *pat3refsym[] = { 704 "__init_begin", 705 "_sinittext", 706 "_einittext", 707 NULL 708 }; 709 710 /* Check for pattern 0 */ 711 if ((strncmp(fromsec, ".text.init.refok", strlen(".text.init.refok")) == 0) || 712 (strncmp(fromsec, ".data.init.refok", strlen(".data.init.refok")) == 0)) 713 return 1; 714 715 /* Check for pattern 1 */ 716 if ((strcmp(tosec, ".init.data") == 0) && 717 (strncmp(fromsec, ".data", strlen(".data")) == 0) && 718 (strncmp(atsym, "__param", strlen("__param")) == 0)) 719 return 1; 720 721 /* Check for pattern 2 */ 722 if ((init_section(tosec) || exit_section(tosec)) && data_section(fromsec)) 723 for (s = pat2sym; *s; s++) 724 if (strrcmp(atsym, *s) == 0) 725 return 1; 726 727 /* Check for pattern 3 */ 728 if ((strcmp(fromsec, ".text.head") == 0) && 729 ((strcmp(tosec, ".init.data") == 0) || 730 (strcmp(tosec, ".init.text") == 0))) 731 return 1; 732 733 /* Check for pattern 4 */ 734 for (s = pat3refsym; *s; s++) 735 if (strcmp(refsymname, *s) == 0) 736 return 1; 737 738 /* Check for pattern 5 */ 739 if (strrcmp(tosec, ".text") == 0) 740 len = strlen(tosec) - strlen(".text"); 741 else 742 len = strlen(tosec); 743 if ((strncmp(tosec, fromsec, len) == 0) && (strlen(fromsec) > len) && 744 (strcmp(fromsec + len, ".literal") == 0)) 745 return 1; 746 747 return 0; 748 } 749 750 /** 751 * Find symbol based on relocation record info. 752 * In some cases the symbol supplied is a valid symbol so 753 * return refsym. If st_name != 0 we assume this is a valid symbol. 754 * In other cases the symbol needs to be looked up in the symbol table 755 * based on section and address. 756 * **/ 757 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr, 758 Elf_Sym *relsym) 759 { 760 Elf_Sym *sym; 761 762 if (relsym->st_name != 0) 763 return relsym; 764 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 765 if (sym->st_shndx != relsym->st_shndx) 766 continue; 767 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) 768 continue; 769 if (sym->st_value == addr) 770 return sym; 771 } 772 return NULL; 773 } 774 775 static inline int is_arm_mapping_symbol(const char *str) 776 { 777 return str[0] == '$' && strchr("atd", str[1]) 778 && (str[2] == '\0' || str[2] == '.'); 779 } 780 781 /* 782 * If there's no name there, ignore it; likewise, ignore it if it's 783 * one of the magic symbols emitted used by current ARM tools. 784 * 785 * Otherwise if find_symbols_between() returns those symbols, they'll 786 * fail the whitelist tests and cause lots of false alarms ... fixable 787 * only by merging __exit and __init sections into __text, bloating 788 * the kernel (which is especially evil on embedded platforms). 789 */ 790 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 791 { 792 const char *name = elf->strtab + sym->st_name; 793 794 if (!name || !strlen(name)) 795 return 0; 796 return !is_arm_mapping_symbol(name); 797 } 798 799 /* 800 * Find symbols before or equal addr and after addr - in the section sec. 801 * If we find two symbols with equal offset prefer one with a valid name. 802 * The ELF format may have a better way to detect what type of symbol 803 * it is, but this works for now. 804 **/ 805 static void find_symbols_between(struct elf_info *elf, Elf_Addr addr, 806 const char *sec, 807 Elf_Sym **before, Elf_Sym **after) 808 { 809 Elf_Sym *sym; 810 Elf_Ehdr *hdr = elf->hdr; 811 Elf_Addr beforediff = ~0; 812 Elf_Addr afterdiff = ~0; 813 const char *secstrings = (void *)hdr + 814 elf->sechdrs[hdr->e_shstrndx].sh_offset; 815 816 *before = NULL; 817 *after = NULL; 818 819 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 820 const char *symsec; 821 822 if (sym->st_shndx >= SHN_LORESERVE) 823 continue; 824 symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name; 825 if (strcmp(symsec, sec) != 0) 826 continue; 827 if (!is_valid_name(elf, sym)) 828 continue; 829 if (sym->st_value <= addr) { 830 if ((addr - sym->st_value) < beforediff) { 831 beforediff = addr - sym->st_value; 832 *before = sym; 833 } 834 else if ((addr - sym->st_value) == beforediff) { 835 *before = sym; 836 } 837 } 838 else 839 { 840 if ((sym->st_value - addr) < afterdiff) { 841 afterdiff = sym->st_value - addr; 842 *after = sym; 843 } 844 else if ((sym->st_value - addr) == afterdiff) { 845 *after = sym; 846 } 847 } 848 } 849 } 850 851 /** 852 * Print a warning about a section mismatch. 853 * Try to find symbols near it so user can find it. 854 * Check whitelist before warning - it may be a false positive. 855 **/ 856 static void warn_sec_mismatch(const char *modname, const char *fromsec, 857 struct elf_info *elf, Elf_Sym *sym, Elf_Rela r) 858 { 859 const char *refsymname = ""; 860 Elf_Sym *before, *after; 861 Elf_Sym *refsym; 862 Elf_Ehdr *hdr = elf->hdr; 863 Elf_Shdr *sechdrs = elf->sechdrs; 864 const char *secstrings = (void *)hdr + 865 sechdrs[hdr->e_shstrndx].sh_offset; 866 const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name; 867 868 find_symbols_between(elf, r.r_offset, fromsec, &before, &after); 869 870 refsym = find_elf_symbol(elf, r.r_addend, sym); 871 if (refsym && strlen(elf->strtab + refsym->st_name)) 872 refsymname = elf->strtab + refsym->st_name; 873 874 /* check whitelist - we may ignore it */ 875 if (secref_whitelist(modname, secname, fromsec, 876 before ? elf->strtab + before->st_name : "", 877 refsymname)) 878 return; 879 880 if (before && after) { 881 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " 882 "(between '%s' and '%s')\n", 883 modname, fromsec, (unsigned long long)r.r_offset, 884 secname, refsymname, 885 elf->strtab + before->st_name, 886 elf->strtab + after->st_name); 887 } else if (before) { 888 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " 889 "(after '%s')\n", 890 modname, fromsec, (unsigned long long)r.r_offset, 891 secname, refsymname, 892 elf->strtab + before->st_name); 893 } else if (after) { 894 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " 895 "before '%s' (at offset -0x%llx)\n", 896 modname, fromsec, (unsigned long long)r.r_offset, 897 secname, refsymname, 898 elf->strtab + after->st_name); 899 } else { 900 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s\n", 901 modname, fromsec, (unsigned long long)r.r_offset, 902 secname, refsymname); 903 } 904 } 905 906 static unsigned int *reloc_location(struct elf_info *elf, 907 int rsection, Elf_Rela *r) 908 { 909 Elf_Shdr *sechdrs = elf->sechdrs; 910 int section = sechdrs[rsection].sh_info; 911 912 return (void *)elf->hdr + sechdrs[section].sh_offset + 913 (r->r_offset - sechdrs[section].sh_addr); 914 } 915 916 static int addend_386_rel(struct elf_info *elf, int rsection, Elf_Rela *r) 917 { 918 unsigned int r_typ = ELF_R_TYPE(r->r_info); 919 unsigned int *location = reloc_location(elf, rsection, r); 920 921 switch (r_typ) { 922 case R_386_32: 923 r->r_addend = TO_NATIVE(*location); 924 break; 925 case R_386_PC32: 926 r->r_addend = TO_NATIVE(*location) + 4; 927 /* For CONFIG_RELOCATABLE=y */ 928 if (elf->hdr->e_type == ET_EXEC) 929 r->r_addend += r->r_offset; 930 break; 931 } 932 return 0; 933 } 934 935 static int addend_arm_rel(struct elf_info *elf, int rsection, Elf_Rela *r) 936 { 937 unsigned int r_typ = ELF_R_TYPE(r->r_info); 938 939 switch (r_typ) { 940 case R_ARM_ABS32: 941 /* From ARM ABI: (S + A) | T */ 942 r->r_addend = (int)(long)(elf->symtab_start + ELF_R_SYM(r->r_info)); 943 break; 944 case R_ARM_PC24: 945 /* From ARM ABI: ((S + A) | T) - P */ 946 r->r_addend = (int)(long)(elf->hdr + elf->sechdrs[rsection].sh_offset + 947 (r->r_offset - elf->sechdrs[rsection].sh_addr)); 948 break; 949 default: 950 return 1; 951 } 952 return 0; 953 } 954 955 static int addend_mips_rel(struct elf_info *elf, int rsection, Elf_Rela *r) 956 { 957 unsigned int r_typ = ELF_R_TYPE(r->r_info); 958 unsigned int *location = reloc_location(elf, rsection, r); 959 unsigned int inst; 960 961 if (r_typ == R_MIPS_HI16) 962 return 1; /* skip this */ 963 inst = TO_NATIVE(*location); 964 switch (r_typ) { 965 case R_MIPS_LO16: 966 r->r_addend = inst & 0xffff; 967 break; 968 case R_MIPS_26: 969 r->r_addend = (inst & 0x03ffffff) << 2; 970 break; 971 case R_MIPS_32: 972 r->r_addend = inst; 973 break; 974 } 975 return 0; 976 } 977 978 /** 979 * A module includes a number of sections that are discarded 980 * either when loaded or when used as built-in. 981 * For loaded modules all functions marked __init and all data 982 * marked __initdata will be discarded when the module has been intialized. 983 * Likewise for modules used built-in the sections marked __exit 984 * are discarded because __exit marked function are supposed to be called 985 * only when a moduel is unloaded which never happes for built-in modules. 986 * The check_sec_ref() function traverses all relocation records 987 * to find all references to a section that reference a section that will 988 * be discarded and warns about it. 989 **/ 990 static void check_sec_ref(struct module *mod, const char *modname, 991 struct elf_info *elf, 992 int section(const char*), 993 int section_ref_ok(const char *)) 994 { 995 int i; 996 Elf_Sym *sym; 997 Elf_Ehdr *hdr = elf->hdr; 998 Elf_Shdr *sechdrs = elf->sechdrs; 999 const char *secstrings = (void *)hdr + 1000 sechdrs[hdr->e_shstrndx].sh_offset; 1001 1002 /* Walk through all sections */ 1003 for (i = 0; i < hdr->e_shnum; i++) { 1004 const char *name = secstrings + sechdrs[i].sh_name; 1005 const char *secname; 1006 Elf_Rela r; 1007 unsigned int r_sym; 1008 /* We want to process only relocation sections and not .init */ 1009 if (sechdrs[i].sh_type == SHT_RELA) { 1010 Elf_Rela *rela; 1011 Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset; 1012 Elf_Rela *stop = (void*)start + sechdrs[i].sh_size; 1013 name += strlen(".rela"); 1014 if (section_ref_ok(name)) 1015 continue; 1016 1017 for (rela = start; rela < stop; rela++) { 1018 r.r_offset = TO_NATIVE(rela->r_offset); 1019 #if KERNEL_ELFCLASS == ELFCLASS64 1020 if (hdr->e_machine == EM_MIPS) { 1021 unsigned int r_typ; 1022 r_sym = ELF64_MIPS_R_SYM(rela->r_info); 1023 r_sym = TO_NATIVE(r_sym); 1024 r_typ = ELF64_MIPS_R_TYPE(rela->r_info); 1025 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1026 } else { 1027 r.r_info = TO_NATIVE(rela->r_info); 1028 r_sym = ELF_R_SYM(r.r_info); 1029 } 1030 #else 1031 r.r_info = TO_NATIVE(rela->r_info); 1032 r_sym = ELF_R_SYM(r.r_info); 1033 #endif 1034 r.r_addend = TO_NATIVE(rela->r_addend); 1035 sym = elf->symtab_start + r_sym; 1036 /* Skip special sections */ 1037 if (sym->st_shndx >= SHN_LORESERVE) 1038 continue; 1039 1040 secname = secstrings + 1041 sechdrs[sym->st_shndx].sh_name; 1042 if (section(secname)) 1043 warn_sec_mismatch(modname, name, 1044 elf, sym, r); 1045 } 1046 } else if (sechdrs[i].sh_type == SHT_REL) { 1047 Elf_Rel *rel; 1048 Elf_Rel *start = (void *)hdr + sechdrs[i].sh_offset; 1049 Elf_Rel *stop = (void*)start + sechdrs[i].sh_size; 1050 name += strlen(".rel"); 1051 if (section_ref_ok(name)) 1052 continue; 1053 1054 for (rel = start; rel < stop; rel++) { 1055 r.r_offset = TO_NATIVE(rel->r_offset); 1056 #if KERNEL_ELFCLASS == ELFCLASS64 1057 if (hdr->e_machine == EM_MIPS) { 1058 unsigned int r_typ; 1059 r_sym = ELF64_MIPS_R_SYM(rel->r_info); 1060 r_sym = TO_NATIVE(r_sym); 1061 r_typ = ELF64_MIPS_R_TYPE(rel->r_info); 1062 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1063 } else { 1064 r.r_info = TO_NATIVE(rel->r_info); 1065 r_sym = ELF_R_SYM(r.r_info); 1066 } 1067 #else 1068 r.r_info = TO_NATIVE(rel->r_info); 1069 r_sym = ELF_R_SYM(r.r_info); 1070 #endif 1071 r.r_addend = 0; 1072 switch (hdr->e_machine) { 1073 case EM_386: 1074 if (addend_386_rel(elf, i, &r)) 1075 continue; 1076 break; 1077 case EM_ARM: 1078 if(addend_arm_rel(elf, i, &r)) 1079 continue; 1080 break; 1081 case EM_MIPS: 1082 if (addend_mips_rel(elf, i, &r)) 1083 continue; 1084 break; 1085 } 1086 sym = elf->symtab_start + r_sym; 1087 /* Skip special sections */ 1088 if (sym->st_shndx >= SHN_LORESERVE) 1089 continue; 1090 1091 secname = secstrings + 1092 sechdrs[sym->st_shndx].sh_name; 1093 if (section(secname)) 1094 warn_sec_mismatch(modname, name, 1095 elf, sym, r); 1096 } 1097 } 1098 } 1099 } 1100 1101 /* 1102 * Identify sections from which references to either a 1103 * .init or a .exit section is OK. 1104 * 1105 * [OPD] Keith Ownes <kaos@sgi.com> commented: 1106 * For our future {in}sanity, add a comment that this is the ppc .opd 1107 * section, not the ia64 .opd section. 1108 * ia64 .opd should not point to discarded sections. 1109 * [.rodata] like for .init.text we ignore .rodata references -same reason 1110 */ 1111 static int initexit_section_ref_ok(const char *name) 1112 { 1113 const char **s; 1114 /* Absolute section names */ 1115 const char *namelist1[] = { 1116 "__bug_table", /* used by powerpc for BUG() */ 1117 "__ex_table", 1118 ".altinstructions", 1119 ".cranges", /* used by sh64 */ 1120 ".fixup", 1121 ".machvec", /* ia64 + powerpc uses these */ 1122 ".machine.desc", 1123 ".opd", /* See comment [OPD] */ 1124 ".parainstructions", 1125 ".pdr", 1126 ".plt", /* seen on ARCH=um build on x86_64. Harmless */ 1127 ".smp_locks", 1128 ".stab", 1129 ".m68k_fixup", 1130 ".xt.prop", /* xtensa informational section */ 1131 ".xt.lit", /* xtensa informational section */ 1132 NULL 1133 }; 1134 /* Start of section names */ 1135 const char *namelist2[] = { 1136 ".debug", 1137 ".eh_frame", 1138 ".note", /* ignore ELF notes - may contain anything */ 1139 ".got", /* powerpc - global offset table */ 1140 ".toc", /* powerpc - table of contents */ 1141 NULL 1142 }; 1143 /* part of section name */ 1144 const char *namelist3 [] = { 1145 ".unwind", /* Sample: IA_64.unwind.exit.text */ 1146 NULL 1147 }; 1148 1149 for (s = namelist1; *s; s++) 1150 if (strcmp(*s, name) == 0) 1151 return 1; 1152 for (s = namelist2; *s; s++) 1153 if (strncmp(*s, name, strlen(*s)) == 0) 1154 return 1; 1155 for (s = namelist3; *s; s++) 1156 if (strstr(name, *s) != NULL) 1157 return 1; 1158 return 0; 1159 } 1160 1161 1162 /* 1163 * Identify sections from which references to a .init section is OK. 1164 * 1165 * Unfortunately references to read only data that referenced .init 1166 * sections had to be excluded. Almost all of these are false 1167 * positives, they are created by gcc. The downside of excluding rodata 1168 * is that there really are some user references from rodata to 1169 * init code, e.g. drivers/video/vgacon.c: 1170 * 1171 * const struct consw vga_con = { 1172 * con_startup: vgacon_startup, 1173 * 1174 * where vgacon_startup is __init. If you want to wade through the false 1175 * positives, take out the check for rodata. 1176 */ 1177 static int init_section_ref_ok(const char *name) 1178 { 1179 const char **s; 1180 /* Absolute section names */ 1181 const char *namelist1[] = { 1182 "__dbe_table", /* MIPS generate these */ 1183 "__ftr_fixup", /* powerpc cpu feature fixup */ 1184 "__fw_ftr_fixup", /* powerpc firmware feature fixup */ 1185 "__param", 1186 ".data.rel.ro", /* used by parisc64 */ 1187 ".init", 1188 ".text.lock", 1189 NULL 1190 }; 1191 /* Start of section names */ 1192 const char *namelist2[] = { 1193 ".init.", 1194 ".pci_fixup", 1195 ".rodata", 1196 NULL 1197 }; 1198 1199 if (initexit_section_ref_ok(name)) 1200 return 1; 1201 1202 for (s = namelist1; *s; s++) 1203 if (strcmp(*s, name) == 0) 1204 return 1; 1205 for (s = namelist2; *s; s++) 1206 if (strncmp(*s, name, strlen(*s)) == 0) 1207 return 1; 1208 1209 /* If section name ends with ".init" we allow references 1210 * as is the case with .initcallN.init, .early_param.init, .taglist.init etc 1211 */ 1212 if (strrcmp(name, ".init") == 0) 1213 return 1; 1214 return 0; 1215 } 1216 1217 /* 1218 * Identify sections from which references to a .exit section is OK. 1219 */ 1220 static int exit_section_ref_ok(const char *name) 1221 { 1222 const char **s; 1223 /* Absolute section names */ 1224 const char *namelist1[] = { 1225 ".exit.data", 1226 ".exit.text", 1227 ".exitcall.exit", 1228 ".rodata", 1229 NULL 1230 }; 1231 1232 if (initexit_section_ref_ok(name)) 1233 return 1; 1234 1235 for (s = namelist1; *s; s++) 1236 if (strcmp(*s, name) == 0) 1237 return 1; 1238 return 0; 1239 } 1240 1241 static void read_symbols(char *modname) 1242 { 1243 const char *symname; 1244 char *version; 1245 char *license; 1246 struct module *mod; 1247 struct elf_info info = { }; 1248 Elf_Sym *sym; 1249 1250 if (!parse_elf(&info, modname)) 1251 return; 1252 1253 mod = new_module(modname); 1254 1255 /* When there's no vmlinux, don't print warnings about 1256 * unresolved symbols (since there'll be too many ;) */ 1257 if (is_vmlinux(modname)) { 1258 have_vmlinux = 1; 1259 mod->skip = 1; 1260 } 1261 1262 license = get_modinfo(info.modinfo, info.modinfo_len, "license"); 1263 while (license) { 1264 if (license_is_gpl_compatible(license)) 1265 mod->gpl_compatible = 1; 1266 else { 1267 mod->gpl_compatible = 0; 1268 break; 1269 } 1270 license = get_next_modinfo(info.modinfo, info.modinfo_len, 1271 "license", license); 1272 } 1273 1274 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1275 symname = info.strtab + sym->st_name; 1276 1277 handle_modversions(mod, &info, sym, symname); 1278 handle_moddevtable(mod, &info, sym, symname); 1279 } 1280 if (is_vmlinux(modname) && vmlinux_section_warnings) { 1281 check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok); 1282 check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok); 1283 } 1284 1285 version = get_modinfo(info.modinfo, info.modinfo_len, "version"); 1286 if (version) 1287 maybe_frob_rcs_version(modname, version, info.modinfo, 1288 version - (char *)info.hdr); 1289 if (version || (all_versions && !is_vmlinux(modname))) 1290 get_src_version(modname, mod->srcversion, 1291 sizeof(mod->srcversion)-1); 1292 1293 parse_elf_finish(&info); 1294 1295 /* Our trick to get versioning for struct_module - it's 1296 * never passed as an argument to an exported function, so 1297 * the automatic versioning doesn't pick it up, but it's really 1298 * important anyhow */ 1299 if (modversions) 1300 mod->unres = alloc_symbol("struct_module", 0, mod->unres); 1301 } 1302 1303 #define SZ 500 1304 1305 /* We first write the generated file into memory using the 1306 * following helper, then compare to the file on disk and 1307 * only update the later if anything changed */ 1308 1309 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1310 const char *fmt, ...) 1311 { 1312 char tmp[SZ]; 1313 int len; 1314 va_list ap; 1315 1316 va_start(ap, fmt); 1317 len = vsnprintf(tmp, SZ, fmt, ap); 1318 buf_write(buf, tmp, len); 1319 va_end(ap); 1320 } 1321 1322 void buf_write(struct buffer *buf, const char *s, int len) 1323 { 1324 if (buf->size - buf->pos < len) { 1325 buf->size += len + SZ; 1326 buf->p = realloc(buf->p, buf->size); 1327 } 1328 strncpy(buf->p + buf->pos, s, len); 1329 buf->pos += len; 1330 } 1331 1332 static void check_for_gpl_usage(enum export exp, const char *m, const char *s) 1333 { 1334 const char *e = is_vmlinux(m) ?"":".ko"; 1335 1336 switch (exp) { 1337 case export_gpl: 1338 fatal("modpost: GPL-incompatible module %s%s " 1339 "uses GPL-only symbol '%s'\n", m, e, s); 1340 break; 1341 case export_unused_gpl: 1342 fatal("modpost: GPL-incompatible module %s%s " 1343 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); 1344 break; 1345 case export_gpl_future: 1346 warn("modpost: GPL-incompatible module %s%s " 1347 "uses future GPL-only symbol '%s'\n", m, e, s); 1348 break; 1349 case export_plain: 1350 case export_unused: 1351 case export_unknown: 1352 /* ignore */ 1353 break; 1354 } 1355 } 1356 1357 static void check_for_unused(enum export exp, const char* m, const char* s) 1358 { 1359 const char *e = is_vmlinux(m) ?"":".ko"; 1360 1361 switch (exp) { 1362 case export_unused: 1363 case export_unused_gpl: 1364 warn("modpost: module %s%s " 1365 "uses symbol '%s' marked UNUSED\n", m, e, s); 1366 break; 1367 default: 1368 /* ignore */ 1369 break; 1370 } 1371 } 1372 1373 static void check_exports(struct module *mod) 1374 { 1375 struct symbol *s, *exp; 1376 1377 for (s = mod->unres; s; s = s->next) { 1378 const char *basename; 1379 exp = find_symbol(s->name); 1380 if (!exp || exp->module == mod) 1381 continue; 1382 basename = strrchr(mod->name, '/'); 1383 if (basename) 1384 basename++; 1385 else 1386 basename = mod->name; 1387 if (!mod->gpl_compatible) 1388 check_for_gpl_usage(exp->export, basename, exp->name); 1389 check_for_unused(exp->export, basename, exp->name); 1390 } 1391 } 1392 1393 /** 1394 * Header for the generated file 1395 **/ 1396 static void add_header(struct buffer *b, struct module *mod) 1397 { 1398 buf_printf(b, "#include <linux/module.h>\n"); 1399 buf_printf(b, "#include <linux/vermagic.h>\n"); 1400 buf_printf(b, "#include <linux/compiler.h>\n"); 1401 buf_printf(b, "\n"); 1402 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1403 buf_printf(b, "\n"); 1404 buf_printf(b, "struct module __this_module\n"); 1405 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); 1406 buf_printf(b, " .name = KBUILD_MODNAME,\n"); 1407 if (mod->has_init) 1408 buf_printf(b, " .init = init_module,\n"); 1409 if (mod->has_cleanup) 1410 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1411 " .exit = cleanup_module,\n" 1412 "#endif\n"); 1413 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n"); 1414 buf_printf(b, "};\n"); 1415 } 1416 1417 /** 1418 * Record CRCs for unresolved symbols 1419 **/ 1420 static int add_versions(struct buffer *b, struct module *mod) 1421 { 1422 struct symbol *s, *exp; 1423 int err = 0; 1424 1425 for (s = mod->unres; s; s = s->next) { 1426 exp = find_symbol(s->name); 1427 if (!exp || exp->module == mod) { 1428 if (have_vmlinux && !s->weak) { 1429 if (warn_unresolved) { 1430 warn("\"%s\" [%s.ko] undefined!\n", 1431 s->name, mod->name); 1432 } else { 1433 merror("\"%s\" [%s.ko] undefined!\n", 1434 s->name, mod->name); 1435 err = 1; 1436 } 1437 } 1438 continue; 1439 } 1440 s->module = exp->module; 1441 s->crc_valid = exp->crc_valid; 1442 s->crc = exp->crc; 1443 } 1444 1445 if (!modversions) 1446 return err; 1447 1448 buf_printf(b, "\n"); 1449 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1450 buf_printf(b, "__attribute_used__\n"); 1451 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); 1452 1453 for (s = mod->unres; s; s = s->next) { 1454 if (!s->module) { 1455 continue; 1456 } 1457 if (!s->crc_valid) { 1458 warn("\"%s\" [%s.ko] has no CRC!\n", 1459 s->name, mod->name); 1460 continue; 1461 } 1462 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); 1463 } 1464 1465 buf_printf(b, "};\n"); 1466 1467 return err; 1468 } 1469 1470 static void add_depends(struct buffer *b, struct module *mod, 1471 struct module *modules) 1472 { 1473 struct symbol *s; 1474 struct module *m; 1475 int first = 1; 1476 1477 for (m = modules; m; m = m->next) { 1478 m->seen = is_vmlinux(m->name); 1479 } 1480 1481 buf_printf(b, "\n"); 1482 buf_printf(b, "static const char __module_depends[]\n"); 1483 buf_printf(b, "__attribute_used__\n"); 1484 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); 1485 buf_printf(b, "\"depends="); 1486 for (s = mod->unres; s; s = s->next) { 1487 const char *p; 1488 if (!s->module) 1489 continue; 1490 1491 if (s->module->seen) 1492 continue; 1493 1494 s->module->seen = 1; 1495 if ((p = strrchr(s->module->name, '/')) != NULL) 1496 p++; 1497 else 1498 p = s->module->name; 1499 buf_printf(b, "%s%s", first ? "" : ",", p); 1500 first = 0; 1501 } 1502 buf_printf(b, "\";\n"); 1503 } 1504 1505 static void add_srcversion(struct buffer *b, struct module *mod) 1506 { 1507 if (mod->srcversion[0]) { 1508 buf_printf(b, "\n"); 1509 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1510 mod->srcversion); 1511 } 1512 } 1513 1514 static void write_if_changed(struct buffer *b, const char *fname) 1515 { 1516 char *tmp; 1517 FILE *file; 1518 struct stat st; 1519 1520 file = fopen(fname, "r"); 1521 if (!file) 1522 goto write; 1523 1524 if (fstat(fileno(file), &st) < 0) 1525 goto close_write; 1526 1527 if (st.st_size != b->pos) 1528 goto close_write; 1529 1530 tmp = NOFAIL(malloc(b->pos)); 1531 if (fread(tmp, 1, b->pos, file) != b->pos) 1532 goto free_write; 1533 1534 if (memcmp(tmp, b->p, b->pos) != 0) 1535 goto free_write; 1536 1537 free(tmp); 1538 fclose(file); 1539 return; 1540 1541 free_write: 1542 free(tmp); 1543 close_write: 1544 fclose(file); 1545 write: 1546 file = fopen(fname, "w"); 1547 if (!file) { 1548 perror(fname); 1549 exit(1); 1550 } 1551 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1552 perror(fname); 1553 exit(1); 1554 } 1555 fclose(file); 1556 } 1557 1558 /* parse Module.symvers file. line format: 1559 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] 1560 **/ 1561 static void read_dump(const char *fname, unsigned int kernel) 1562 { 1563 unsigned long size, pos = 0; 1564 void *file = grab_file(fname, &size); 1565 char *line; 1566 1567 if (!file) 1568 /* No symbol versions, silently ignore */ 1569 return; 1570 1571 while ((line = get_next_line(&pos, file, size))) { 1572 char *symname, *modname, *d, *export, *end; 1573 unsigned int crc; 1574 struct module *mod; 1575 struct symbol *s; 1576 1577 if (!(symname = strchr(line, '\t'))) 1578 goto fail; 1579 *symname++ = '\0'; 1580 if (!(modname = strchr(symname, '\t'))) 1581 goto fail; 1582 *modname++ = '\0'; 1583 if ((export = strchr(modname, '\t')) != NULL) 1584 *export++ = '\0'; 1585 if (export && ((end = strchr(export, '\t')) != NULL)) 1586 *end = '\0'; 1587 crc = strtoul(line, &d, 16); 1588 if (*symname == '\0' || *modname == '\0' || *d != '\0') 1589 goto fail; 1590 1591 if (!(mod = find_module(modname))) { 1592 if (is_vmlinux(modname)) { 1593 have_vmlinux = 1; 1594 } 1595 mod = new_module(NOFAIL(strdup(modname))); 1596 mod->skip = 1; 1597 } 1598 s = sym_add_exported(symname, mod, export_no(export)); 1599 s->kernel = kernel; 1600 s->preloaded = 1; 1601 sym_update_crc(symname, mod, crc, export_no(export)); 1602 } 1603 return; 1604 fail: 1605 fatal("parse error in symbol dump file\n"); 1606 } 1607 1608 /* For normal builds always dump all symbols. 1609 * For external modules only dump symbols 1610 * that are not read from kernel Module.symvers. 1611 **/ 1612 static int dump_sym(struct symbol *sym) 1613 { 1614 if (!external_module) 1615 return 1; 1616 if (sym->vmlinux || sym->kernel) 1617 return 0; 1618 return 1; 1619 } 1620 1621 static void write_dump(const char *fname) 1622 { 1623 struct buffer buf = { }; 1624 struct symbol *symbol; 1625 int n; 1626 1627 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { 1628 symbol = symbolhash[n]; 1629 while (symbol) { 1630 if (dump_sym(symbol)) 1631 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", 1632 symbol->crc, symbol->name, 1633 symbol->module->name, 1634 export_str(symbol->export)); 1635 symbol = symbol->next; 1636 } 1637 } 1638 write_if_changed(&buf, fname); 1639 } 1640 1641 int main(int argc, char **argv) 1642 { 1643 struct module *mod; 1644 struct buffer buf = { }; 1645 char fname[SZ]; 1646 char *kernel_read = NULL, *module_read = NULL; 1647 char *dump_write = NULL; 1648 int opt; 1649 int err; 1650 1651 while ((opt = getopt(argc, argv, "i:I:mso:aw")) != -1) { 1652 switch(opt) { 1653 case 'i': 1654 kernel_read = optarg; 1655 break; 1656 case 'I': 1657 module_read = optarg; 1658 external_module = 1; 1659 break; 1660 case 'm': 1661 modversions = 1; 1662 break; 1663 case 'o': 1664 dump_write = optarg; 1665 break; 1666 case 'a': 1667 all_versions = 1; 1668 break; 1669 case 's': 1670 vmlinux_section_warnings = 0; 1671 break; 1672 case 'w': 1673 warn_unresolved = 1; 1674 break; 1675 default: 1676 exit(1); 1677 } 1678 } 1679 1680 if (kernel_read) 1681 read_dump(kernel_read, 1); 1682 if (module_read) 1683 read_dump(module_read, 0); 1684 1685 while (optind < argc) { 1686 read_symbols(argv[optind++]); 1687 } 1688 1689 for (mod = modules; mod; mod = mod->next) { 1690 if (mod->skip) 1691 continue; 1692 check_exports(mod); 1693 } 1694 1695 err = 0; 1696 1697 for (mod = modules; mod; mod = mod->next) { 1698 if (mod->skip) 1699 continue; 1700 1701 buf.pos = 0; 1702 1703 add_header(&buf, mod); 1704 err |= add_versions(&buf, mod); 1705 add_depends(&buf, mod, modules); 1706 add_moddevtable(&buf, mod); 1707 add_srcversion(&buf, mod); 1708 1709 sprintf(fname, "%s.mod.c", mod->name); 1710 write_if_changed(&buf, fname); 1711 } 1712 1713 if (dump_write) 1714 write_dump(dump_write); 1715 1716 return err; 1717 } 1718