1 /* Postprocess module symbol versions 2 * 3 * Copyright 2003 Kai Germaschewski 4 * Copyright 2002-2004 Rusty Russell, IBM Corporation 5 * Copyright 2006-2008 Sam Ravnborg 6 * Based in part on module-init-tools/depmod.c,file2alias 7 * 8 * This software may be used and distributed according to the terms 9 * of the GNU General Public License, incorporated herein by reference. 10 * 11 * Usage: modpost vmlinux module1.o module2.o ... 12 */ 13 14 #define _GNU_SOURCE 15 #include <stdio.h> 16 #include <ctype.h> 17 #include <string.h> 18 #include "modpost.h" 19 #include "../../include/generated/autoconf.h" 20 #include "../../include/linux/license.h" 21 22 /* Some toolchains use a `_' prefix for all user symbols. */ 23 #ifdef CONFIG_SYMBOL_PREFIX 24 #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX 25 #else 26 #define MODULE_SYMBOL_PREFIX "" 27 #endif 28 29 30 /* Are we using CONFIG_MODVERSIONS? */ 31 int modversions = 0; 32 /* Warn about undefined symbols? (do so if we have vmlinux) */ 33 int have_vmlinux = 0; 34 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 35 static int all_versions = 0; 36 /* If we are modposting external module set to 1 */ 37 static int external_module = 0; 38 /* Warn about section mismatch in vmlinux if set to 1 */ 39 static int vmlinux_section_warnings = 1; 40 /* Only warn about unresolved symbols */ 41 static int warn_unresolved = 0; 42 /* How a symbol is exported */ 43 static int sec_mismatch_count = 0; 44 static int sec_mismatch_verbose = 1; 45 46 enum export { 47 export_plain, export_unused, export_gpl, 48 export_unused_gpl, export_gpl_future, export_unknown 49 }; 50 51 #define PRINTF __attribute__ ((format (printf, 1, 2))) 52 53 PRINTF void fatal(const char *fmt, ...) 54 { 55 va_list arglist; 56 57 fprintf(stderr, "FATAL: "); 58 59 va_start(arglist, fmt); 60 vfprintf(stderr, fmt, arglist); 61 va_end(arglist); 62 63 exit(1); 64 } 65 66 PRINTF void warn(const char *fmt, ...) 67 { 68 va_list arglist; 69 70 fprintf(stderr, "WARNING: "); 71 72 va_start(arglist, fmt); 73 vfprintf(stderr, fmt, arglist); 74 va_end(arglist); 75 } 76 77 PRINTF void merror(const char *fmt, ...) 78 { 79 va_list arglist; 80 81 fprintf(stderr, "ERROR: "); 82 83 va_start(arglist, fmt); 84 vfprintf(stderr, fmt, arglist); 85 va_end(arglist); 86 } 87 88 static int is_vmlinux(const char *modname) 89 { 90 const char *myname; 91 92 myname = strrchr(modname, '/'); 93 if (myname) 94 myname++; 95 else 96 myname = modname; 97 98 return (strcmp(myname, "vmlinux") == 0) || 99 (strcmp(myname, "vmlinux.o") == 0); 100 } 101 102 void *do_nofail(void *ptr, const char *expr) 103 { 104 if (!ptr) 105 fatal("modpost: Memory allocation failure: %s.\n", expr); 106 107 return ptr; 108 } 109 110 /* A list of all modules we processed */ 111 static struct module *modules; 112 113 static struct module *find_module(char *modname) 114 { 115 struct module *mod; 116 117 for (mod = modules; mod; mod = mod->next) 118 if (strcmp(mod->name, modname) == 0) 119 break; 120 return mod; 121 } 122 123 static struct module *new_module(char *modname) 124 { 125 struct module *mod; 126 char *p, *s; 127 128 mod = NOFAIL(malloc(sizeof(*mod))); 129 memset(mod, 0, sizeof(*mod)); 130 p = NOFAIL(strdup(modname)); 131 132 /* strip trailing .o */ 133 s = strrchr(p, '.'); 134 if (s != NULL) 135 if (strcmp(s, ".o") == 0) { 136 *s = '\0'; 137 mod->is_dot_o = 1; 138 } 139 140 /* add to list */ 141 mod->name = p; 142 mod->gpl_compatible = -1; 143 mod->next = modules; 144 modules = mod; 145 146 return mod; 147 } 148 149 /* A hash of all exported symbols, 150 * struct symbol is also used for lists of unresolved symbols */ 151 152 #define SYMBOL_HASH_SIZE 1024 153 154 struct symbol { 155 struct symbol *next; 156 struct module *module; 157 unsigned int crc; 158 int crc_valid; 159 unsigned int weak:1; 160 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */ 161 unsigned int kernel:1; /* 1 if symbol is from kernel 162 * (only for external modules) **/ 163 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */ 164 enum export export; /* Type of export */ 165 char name[0]; 166 }; 167 168 static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 169 170 /* This is based on the hash agorithm from gdbm, via tdb */ 171 static inline unsigned int tdb_hash(const char *name) 172 { 173 unsigned value; /* Used to compute the hash value. */ 174 unsigned i; /* Used to cycle through random values. */ 175 176 /* Set the initial value from the key size. */ 177 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++) 178 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 179 180 return (1103515243 * value + 12345); 181 } 182 183 /** 184 * Allocate a new symbols for use in the hash of exported symbols or 185 * the list of unresolved symbols per module 186 **/ 187 static struct symbol *alloc_symbol(const char *name, unsigned int weak, 188 struct symbol *next) 189 { 190 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 191 192 memset(s, 0, sizeof(*s)); 193 strcpy(s->name, name); 194 s->weak = weak; 195 s->next = next; 196 return s; 197 } 198 199 /* For the hash of exported symbols */ 200 static struct symbol *new_symbol(const char *name, struct module *module, 201 enum export export) 202 { 203 unsigned int hash; 204 struct symbol *new; 205 206 hash = tdb_hash(name) % SYMBOL_HASH_SIZE; 207 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]); 208 new->module = module; 209 new->export = export; 210 return new; 211 } 212 213 static struct symbol *find_symbol(const char *name) 214 { 215 struct symbol *s; 216 217 /* For our purposes, .foo matches foo. PPC64 needs this. */ 218 if (name[0] == '.') 219 name++; 220 221 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) { 222 if (strcmp(s->name, name) == 0) 223 return s; 224 } 225 return NULL; 226 } 227 228 static struct { 229 const char *str; 230 enum export export; 231 } export_list[] = { 232 { .str = "EXPORT_SYMBOL", .export = export_plain }, 233 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused }, 234 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl }, 235 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl }, 236 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future }, 237 { .str = "(unknown)", .export = export_unknown }, 238 }; 239 240 241 static const char *export_str(enum export ex) 242 { 243 return export_list[ex].str; 244 } 245 246 static enum export export_no(const char *s) 247 { 248 int i; 249 250 if (!s) 251 return export_unknown; 252 for (i = 0; export_list[i].export != export_unknown; i++) { 253 if (strcmp(export_list[i].str, s) == 0) 254 return export_list[i].export; 255 } 256 return export_unknown; 257 } 258 259 static const char *sec_name(struct elf_info *elf, int secindex); 260 261 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) 262 263 static enum export export_from_secname(struct elf_info *elf, unsigned int sec) 264 { 265 const char *secname = sec_name(elf, sec); 266 267 if (strstarts(secname, "___ksymtab+")) 268 return export_plain; 269 else if (strstarts(secname, "___ksymtab_unused+")) 270 return export_unused; 271 else if (strstarts(secname, "___ksymtab_gpl+")) 272 return export_gpl; 273 else if (strstarts(secname, "___ksymtab_unused_gpl+")) 274 return export_unused_gpl; 275 else if (strstarts(secname, "___ksymtab_gpl_future+")) 276 return export_gpl_future; 277 else 278 return export_unknown; 279 } 280 281 static enum export export_from_sec(struct elf_info *elf, unsigned int sec) 282 { 283 if (sec == elf->export_sec) 284 return export_plain; 285 else if (sec == elf->export_unused_sec) 286 return export_unused; 287 else if (sec == elf->export_gpl_sec) 288 return export_gpl; 289 else if (sec == elf->export_unused_gpl_sec) 290 return export_unused_gpl; 291 else if (sec == elf->export_gpl_future_sec) 292 return export_gpl_future; 293 else 294 return export_unknown; 295 } 296 297 /** 298 * Add an exported symbol - it may have already been added without a 299 * CRC, in this case just update the CRC 300 **/ 301 static struct symbol *sym_add_exported(const char *name, struct module *mod, 302 enum export export) 303 { 304 struct symbol *s = find_symbol(name); 305 306 if (!s) { 307 s = new_symbol(name, mod, export); 308 } else { 309 if (!s->preloaded) { 310 warn("%s: '%s' exported twice. Previous export " 311 "was in %s%s\n", mod->name, name, 312 s->module->name, 313 is_vmlinux(s->module->name) ?"":".ko"); 314 } else { 315 /* In case Modules.symvers was out of date */ 316 s->module = mod; 317 } 318 } 319 s->preloaded = 0; 320 s->vmlinux = is_vmlinux(mod->name); 321 s->kernel = 0; 322 s->export = export; 323 return s; 324 } 325 326 static void sym_update_crc(const char *name, struct module *mod, 327 unsigned int crc, enum export export) 328 { 329 struct symbol *s = find_symbol(name); 330 331 if (!s) 332 s = new_symbol(name, mod, export); 333 s->crc = crc; 334 s->crc_valid = 1; 335 } 336 337 void *grab_file(const char *filename, unsigned long *size) 338 { 339 struct stat st; 340 void *map = MAP_FAILED; 341 int fd; 342 343 fd = open(filename, O_RDONLY); 344 if (fd < 0) 345 return NULL; 346 if (fstat(fd, &st)) 347 goto failed; 348 349 *size = st.st_size; 350 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 351 352 failed: 353 close(fd); 354 if (map == MAP_FAILED) 355 return NULL; 356 return map; 357 } 358 359 /** 360 * Return a copy of the next line in a mmap'ed file. 361 * spaces in the beginning of the line is trimmed away. 362 * Return a pointer to a static buffer. 363 **/ 364 char *get_next_line(unsigned long *pos, void *file, unsigned long size) 365 { 366 static char line[4096]; 367 int skip = 1; 368 size_t len = 0; 369 signed char *p = (signed char *)file + *pos; 370 char *s = line; 371 372 for (; *pos < size ; (*pos)++) { 373 if (skip && isspace(*p)) { 374 p++; 375 continue; 376 } 377 skip = 0; 378 if (*p != '\n' && (*pos < size)) { 379 len++; 380 *s++ = *p++; 381 if (len > 4095) 382 break; /* Too long, stop */ 383 } else { 384 /* End of string */ 385 *s = '\0'; 386 return line; 387 } 388 } 389 /* End of buffer */ 390 return NULL; 391 } 392 393 void release_file(void *file, unsigned long size) 394 { 395 munmap(file, size); 396 } 397 398 static int parse_elf(struct elf_info *info, const char *filename) 399 { 400 unsigned int i; 401 Elf_Ehdr *hdr; 402 Elf_Shdr *sechdrs; 403 Elf_Sym *sym; 404 const char *secstrings; 405 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 406 407 hdr = grab_file(filename, &info->size); 408 if (!hdr) { 409 perror(filename); 410 exit(1); 411 } 412 info->hdr = hdr; 413 if (info->size < sizeof(*hdr)) { 414 /* file too small, assume this is an empty .o file */ 415 return 0; 416 } 417 /* Is this a valid ELF file? */ 418 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 419 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 420 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 421 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 422 /* Not an ELF file - silently ignore it */ 423 return 0; 424 } 425 /* Fix endianness in ELF header */ 426 hdr->e_type = TO_NATIVE(hdr->e_type); 427 hdr->e_machine = TO_NATIVE(hdr->e_machine); 428 hdr->e_version = TO_NATIVE(hdr->e_version); 429 hdr->e_entry = TO_NATIVE(hdr->e_entry); 430 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 431 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 432 hdr->e_flags = TO_NATIVE(hdr->e_flags); 433 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 434 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 435 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 436 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 437 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 438 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 439 sechdrs = (void *)hdr + hdr->e_shoff; 440 info->sechdrs = sechdrs; 441 442 /* Check if file offset is correct */ 443 if (hdr->e_shoff > info->size) { 444 fatal("section header offset=%lu in file '%s' is bigger than " 445 "filesize=%lu\n", (unsigned long)hdr->e_shoff, 446 filename, info->size); 447 return 0; 448 } 449 450 if (hdr->e_shnum == SHN_UNDEF) { 451 /* 452 * There are more than 64k sections, 453 * read count from .sh_size. 454 */ 455 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 456 } 457 else { 458 info->num_sections = hdr->e_shnum; 459 } 460 if (hdr->e_shstrndx == SHN_XINDEX) { 461 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 462 } 463 else { 464 info->secindex_strings = hdr->e_shstrndx; 465 } 466 467 /* Fix endianness in section headers */ 468 for (i = 0; i < info->num_sections; i++) { 469 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 470 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 471 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 472 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 473 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 474 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 475 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 476 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 477 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 478 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 479 } 480 /* Find symbol table. */ 481 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 482 for (i = 1; i < info->num_sections; i++) { 483 const char *secname; 484 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 485 486 if (!nobits && sechdrs[i].sh_offset > info->size) { 487 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > " 488 "sizeof(*hrd)=%zu\n", filename, 489 (unsigned long)sechdrs[i].sh_offset, 490 sizeof(*hdr)); 491 return 0; 492 } 493 secname = secstrings + sechdrs[i].sh_name; 494 if (strcmp(secname, ".modinfo") == 0) { 495 if (nobits) 496 fatal("%s has NOBITS .modinfo\n", filename); 497 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 498 info->modinfo_len = sechdrs[i].sh_size; 499 } else if (strcmp(secname, "__ksymtab") == 0) 500 info->export_sec = i; 501 else if (strcmp(secname, "__ksymtab_unused") == 0) 502 info->export_unused_sec = i; 503 else if (strcmp(secname, "__ksymtab_gpl") == 0) 504 info->export_gpl_sec = i; 505 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0) 506 info->export_unused_gpl_sec = i; 507 else if (strcmp(secname, "__ksymtab_gpl_future") == 0) 508 info->export_gpl_future_sec = i; 509 510 if (sechdrs[i].sh_type == SHT_SYMTAB) { 511 unsigned int sh_link_idx; 512 symtab_idx = i; 513 info->symtab_start = (void *)hdr + 514 sechdrs[i].sh_offset; 515 info->symtab_stop = (void *)hdr + 516 sechdrs[i].sh_offset + sechdrs[i].sh_size; 517 sh_link_idx = sechdrs[i].sh_link; 518 info->strtab = (void *)hdr + 519 sechdrs[sh_link_idx].sh_offset; 520 } 521 522 /* 32bit section no. table? ("more than 64k sections") */ 523 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 524 symtab_shndx_idx = i; 525 info->symtab_shndx_start = (void *)hdr + 526 sechdrs[i].sh_offset; 527 info->symtab_shndx_stop = (void *)hdr + 528 sechdrs[i].sh_offset + sechdrs[i].sh_size; 529 } 530 } 531 if (!info->symtab_start) 532 fatal("%s has no symtab?\n", filename); 533 534 /* Fix endianness in symbols */ 535 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 536 sym->st_shndx = TO_NATIVE(sym->st_shndx); 537 sym->st_name = TO_NATIVE(sym->st_name); 538 sym->st_value = TO_NATIVE(sym->st_value); 539 sym->st_size = TO_NATIVE(sym->st_size); 540 } 541 542 if (symtab_shndx_idx != ~0U) { 543 Elf32_Word *p; 544 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 545 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 546 filename, sechdrs[symtab_shndx_idx].sh_link, 547 symtab_idx); 548 /* Fix endianness */ 549 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 550 p++) 551 *p = TO_NATIVE(*p); 552 } 553 554 return 1; 555 } 556 557 static void parse_elf_finish(struct elf_info *info) 558 { 559 release_file(info->hdr, info->size); 560 } 561 562 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 563 { 564 /* ignore __this_module, it will be resolved shortly */ 565 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0) 566 return 1; 567 /* ignore global offset table */ 568 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 569 return 1; 570 if (info->hdr->e_machine == EM_PPC) 571 /* Special register function linked on all modules during final link of .ko */ 572 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 || 573 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 || 574 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 || 575 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0) 576 return 1; 577 if (info->hdr->e_machine == EM_PPC64) 578 /* Special register function linked on all modules during final link of .ko */ 579 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 || 580 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0) 581 return 1; 582 /* Do not ignore this symbol */ 583 return 0; 584 } 585 586 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_" 587 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_" 588 589 static void handle_modversions(struct module *mod, struct elf_info *info, 590 Elf_Sym *sym, const char *symname) 591 { 592 unsigned int crc; 593 enum export export; 594 595 if ((!is_vmlinux(mod->name) || mod->is_dot_o) && 596 strncmp(symname, "__ksymtab", 9) == 0) 597 export = export_from_secname(info, get_secindex(info, sym)); 598 else 599 export = export_from_sec(info, get_secindex(info, sym)); 600 601 switch (sym->st_shndx) { 602 case SHN_COMMON: 603 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 604 break; 605 case SHN_ABS: 606 /* CRC'd symbol */ 607 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { 608 crc = (unsigned int) sym->st_value; 609 sym_update_crc(symname + strlen(CRC_PFX), mod, crc, 610 export); 611 } 612 break; 613 case SHN_UNDEF: 614 /* undefined symbol */ 615 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 616 ELF_ST_BIND(sym->st_info) != STB_WEAK) 617 break; 618 if (ignore_undef_symbol(info, symname)) 619 break; 620 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */ 621 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER) 622 /* add compatibility with older glibc */ 623 #ifndef STT_SPARC_REGISTER 624 #define STT_SPARC_REGISTER STT_REGISTER 625 #endif 626 if (info->hdr->e_machine == EM_SPARC || 627 info->hdr->e_machine == EM_SPARCV9) { 628 /* Ignore register directives. */ 629 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 630 break; 631 if (symname[0] == '.') { 632 char *munged = strdup(symname); 633 munged[0] = '_'; 634 munged[1] = toupper(munged[1]); 635 symname = munged; 636 } 637 } 638 #endif 639 640 if (memcmp(symname, MODULE_SYMBOL_PREFIX, 641 strlen(MODULE_SYMBOL_PREFIX)) == 0) { 642 mod->unres = 643 alloc_symbol(symname + 644 strlen(MODULE_SYMBOL_PREFIX), 645 ELF_ST_BIND(sym->st_info) == STB_WEAK, 646 mod->unres); 647 } 648 break; 649 default: 650 /* All exported symbols */ 651 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) { 652 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod, 653 export); 654 } 655 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0) 656 mod->has_init = 1; 657 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0) 658 mod->has_cleanup = 1; 659 break; 660 } 661 } 662 663 /** 664 * Parse tag=value strings from .modinfo section 665 **/ 666 static char *next_string(char *string, unsigned long *secsize) 667 { 668 /* Skip non-zero chars */ 669 while (string[0]) { 670 string++; 671 if ((*secsize)-- <= 1) 672 return NULL; 673 } 674 675 /* Skip any zero padding. */ 676 while (!string[0]) { 677 string++; 678 if ((*secsize)-- <= 1) 679 return NULL; 680 } 681 return string; 682 } 683 684 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len, 685 const char *tag, char *info) 686 { 687 char *p; 688 unsigned int taglen = strlen(tag); 689 unsigned long size = modinfo_len; 690 691 if (info) { 692 size -= info - (char *)modinfo; 693 modinfo = next_string(info, &size); 694 } 695 696 for (p = modinfo; p; p = next_string(p, &size)) { 697 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 698 return p + taglen + 1; 699 } 700 return NULL; 701 } 702 703 static char *get_modinfo(void *modinfo, unsigned long modinfo_len, 704 const char *tag) 705 706 { 707 return get_next_modinfo(modinfo, modinfo_len, tag, NULL); 708 } 709 710 /** 711 * Test if string s ends in string sub 712 * return 0 if match 713 **/ 714 static int strrcmp(const char *s, const char *sub) 715 { 716 int slen, sublen; 717 718 if (!s || !sub) 719 return 1; 720 721 slen = strlen(s); 722 sublen = strlen(sub); 723 724 if ((slen == 0) || (sublen == 0)) 725 return 1; 726 727 if (sublen > slen) 728 return 1; 729 730 return memcmp(s + slen - sublen, sub, sublen); 731 } 732 733 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 734 { 735 if (sym) 736 return elf->strtab + sym->st_name; 737 else 738 return "(unknown)"; 739 } 740 741 static const char *sec_name(struct elf_info *elf, int secindex) 742 { 743 Elf_Shdr *sechdrs = elf->sechdrs; 744 return (void *)elf->hdr + 745 elf->sechdrs[elf->secindex_strings].sh_offset + 746 sechdrs[secindex].sh_name; 747 } 748 749 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr) 750 { 751 return (void *)elf->hdr + 752 elf->sechdrs[elf->secindex_strings].sh_offset + 753 sechdr->sh_name; 754 } 755 756 /* if sym is empty or point to a string 757 * like ".[0-9]+" then return 1. 758 * This is the optional prefix added by ld to some sections 759 */ 760 static int number_prefix(const char *sym) 761 { 762 if (*sym++ == '\0') 763 return 1; 764 if (*sym != '.') 765 return 0; 766 do { 767 char c = *sym++; 768 if (c < '0' || c > '9') 769 return 0; 770 } while (*sym); 771 return 1; 772 } 773 774 /* The pattern is an array of simple patterns. 775 * "foo" will match an exact string equal to "foo" 776 * "*foo" will match a string that ends with "foo" 777 * "foo*" will match a string that begins with "foo" 778 * "foo$" will match a string equal to "foo" or "foo.1" 779 * where the '1' can be any number including several digits. 780 * The $ syntax is for sections where ld append a dot number 781 * to make section name unique. 782 */ 783 static int match(const char *sym, const char * const pat[]) 784 { 785 const char *p; 786 while (*pat) { 787 p = *pat++; 788 const char *endp = p + strlen(p) - 1; 789 790 /* "*foo" */ 791 if (*p == '*') { 792 if (strrcmp(sym, p + 1) == 0) 793 return 1; 794 } 795 /* "foo*" */ 796 else if (*endp == '*') { 797 if (strncmp(sym, p, strlen(p) - 1) == 0) 798 return 1; 799 } 800 /* "foo$" */ 801 else if (*endp == '$') { 802 if (strncmp(sym, p, strlen(p) - 1) == 0) { 803 if (number_prefix(sym + strlen(p) - 1)) 804 return 1; 805 } 806 } 807 /* no wildcards */ 808 else { 809 if (strcmp(p, sym) == 0) 810 return 1; 811 } 812 } 813 /* no match */ 814 return 0; 815 } 816 817 /* sections that we do not want to do full section mismatch check on */ 818 static const char *section_white_list[] = 819 { 820 ".comment*", 821 ".debug*", 822 ".zdebug*", /* Compressed debug sections. */ 823 ".GCC-command-line", /* mn10300 */ 824 ".mdebug*", /* alpha, score, mips etc. */ 825 ".pdr", /* alpha, score, mips etc. */ 826 ".stab*", 827 ".note*", 828 ".got*", 829 ".toc*", 830 NULL 831 }; 832 833 /* 834 * This is used to find sections missing the SHF_ALLOC flag. 835 * The cause of this is often a section specified in assembler 836 * without "ax" / "aw". 837 */ 838 static void check_section(const char *modname, struct elf_info *elf, 839 Elf_Shdr *sechdr) 840 { 841 const char *sec = sech_name(elf, sechdr); 842 843 if (sechdr->sh_type == SHT_PROGBITS && 844 !(sechdr->sh_flags & SHF_ALLOC) && 845 !match(sec, section_white_list)) { 846 warn("%s (%s): unexpected non-allocatable section.\n" 847 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 848 "Note that for example <linux/init.h> contains\n" 849 "section definitions for use in .S files.\n\n", 850 modname, sec); 851 } 852 } 853 854 855 856 #define ALL_INIT_DATA_SECTIONS \ 857 ".init.setup$", ".init.rodata$", \ 858 ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$", \ 859 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$" 860 #define ALL_EXIT_DATA_SECTIONS \ 861 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$" 862 863 #define ALL_INIT_TEXT_SECTIONS \ 864 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$" 865 #define ALL_EXIT_TEXT_SECTIONS \ 866 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$" 867 868 #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \ 869 MEM_INIT_SECTIONS 870 #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \ 871 MEM_EXIT_SECTIONS 872 873 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 874 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS 875 876 #define DATA_SECTIONS ".data$", ".data.rel$" 877 #define TEXT_SECTIONS ".text$" 878 879 #define INIT_SECTIONS ".init.*" 880 #define DEV_INIT_SECTIONS ".devinit.*" 881 #define CPU_INIT_SECTIONS ".cpuinit.*" 882 #define MEM_INIT_SECTIONS ".meminit.*" 883 884 #define EXIT_SECTIONS ".exit.*" 885 #define DEV_EXIT_SECTIONS ".devexit.*" 886 #define CPU_EXIT_SECTIONS ".cpuexit.*" 887 #define MEM_EXIT_SECTIONS ".memexit.*" 888 889 /* init data sections */ 890 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL }; 891 892 /* all init sections */ 893 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL }; 894 895 /* All init and exit sections (code + data) */ 896 static const char *init_exit_sections[] = 897 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }; 898 899 /* data section */ 900 static const char *data_sections[] = { DATA_SECTIONS, NULL }; 901 902 903 /* symbols in .data that may refer to init/exit sections */ 904 #define DEFAULT_SYMBOL_WHITE_LIST \ 905 "*driver", \ 906 "*_template", /* scsi uses *_template a lot */ \ 907 "*_timer", /* arm uses ops structures named _timer a lot */ \ 908 "*_sht", /* scsi also used *_sht to some extent */ \ 909 "*_ops", \ 910 "*_probe", \ 911 "*_probe_one", \ 912 "*_console" 913 914 static const char *head_sections[] = { ".head.text*", NULL }; 915 static const char *linker_symbols[] = 916 { "__init_begin", "_sinittext", "_einittext", NULL }; 917 918 enum mismatch { 919 TEXT_TO_ANY_INIT, 920 DATA_TO_ANY_INIT, 921 TEXT_TO_ANY_EXIT, 922 DATA_TO_ANY_EXIT, 923 XXXINIT_TO_SOME_INIT, 924 XXXEXIT_TO_SOME_EXIT, 925 ANY_INIT_TO_ANY_EXIT, 926 ANY_EXIT_TO_ANY_INIT, 927 EXPORT_TO_INIT_EXIT, 928 }; 929 930 struct sectioncheck { 931 const char *fromsec[20]; 932 const char *tosec[20]; 933 enum mismatch mismatch; 934 const char *symbol_white_list[20]; 935 }; 936 937 const struct sectioncheck sectioncheck[] = { 938 /* Do not reference init/exit code/data from 939 * normal code and data 940 */ 941 { 942 .fromsec = { TEXT_SECTIONS, NULL }, 943 .tosec = { ALL_INIT_SECTIONS, NULL }, 944 .mismatch = TEXT_TO_ANY_INIT, 945 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 946 }, 947 { 948 .fromsec = { DATA_SECTIONS, NULL }, 949 .tosec = { ALL_XXXINIT_SECTIONS, NULL }, 950 .mismatch = DATA_TO_ANY_INIT, 951 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 952 }, 953 { 954 .fromsec = { DATA_SECTIONS, NULL }, 955 .tosec = { INIT_SECTIONS, NULL }, 956 .mismatch = DATA_TO_ANY_INIT, 957 .symbol_white_list = { 958 "*_template", "*_timer", "*_sht", "*_ops", 959 "*_probe", "*_probe_one", "*_console", NULL 960 }, 961 }, 962 { 963 .fromsec = { TEXT_SECTIONS, NULL }, 964 .tosec = { ALL_EXIT_SECTIONS, NULL }, 965 .mismatch = TEXT_TO_ANY_EXIT, 966 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 967 }, 968 { 969 .fromsec = { DATA_SECTIONS, NULL }, 970 .tosec = { ALL_EXIT_SECTIONS, NULL }, 971 .mismatch = DATA_TO_ANY_EXIT, 972 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 973 }, 974 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */ 975 { 976 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 977 .tosec = { INIT_SECTIONS, NULL }, 978 .mismatch = XXXINIT_TO_SOME_INIT, 979 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 980 }, 981 /* Do not reference cpuinit code/data from meminit code/data */ 982 { 983 .fromsec = { MEM_INIT_SECTIONS, NULL }, 984 .tosec = { CPU_INIT_SECTIONS, NULL }, 985 .mismatch = XXXINIT_TO_SOME_INIT, 986 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 987 }, 988 /* Do not reference meminit code/data from cpuinit code/data */ 989 { 990 .fromsec = { CPU_INIT_SECTIONS, NULL }, 991 .tosec = { MEM_INIT_SECTIONS, NULL }, 992 .mismatch = XXXINIT_TO_SOME_INIT, 993 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 994 }, 995 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */ 996 { 997 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL }, 998 .tosec = { EXIT_SECTIONS, NULL }, 999 .mismatch = XXXEXIT_TO_SOME_EXIT, 1000 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1001 }, 1002 /* Do not reference cpuexit code/data from memexit code/data */ 1003 { 1004 .fromsec = { MEM_EXIT_SECTIONS, NULL }, 1005 .tosec = { CPU_EXIT_SECTIONS, NULL }, 1006 .mismatch = XXXEXIT_TO_SOME_EXIT, 1007 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1008 }, 1009 /* Do not reference memexit code/data from cpuexit code/data */ 1010 { 1011 .fromsec = { CPU_EXIT_SECTIONS, NULL }, 1012 .tosec = { MEM_EXIT_SECTIONS, NULL }, 1013 .mismatch = XXXEXIT_TO_SOME_EXIT, 1014 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1015 }, 1016 /* Do not use exit code/data from init code */ 1017 { 1018 .fromsec = { ALL_INIT_SECTIONS, NULL }, 1019 .tosec = { ALL_EXIT_SECTIONS, NULL }, 1020 .mismatch = ANY_INIT_TO_ANY_EXIT, 1021 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1022 }, 1023 /* Do not use init code/data from exit code */ 1024 { 1025 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 1026 .tosec = { ALL_INIT_SECTIONS, NULL }, 1027 .mismatch = ANY_EXIT_TO_ANY_INIT, 1028 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1029 }, 1030 /* Do not export init/exit functions or data */ 1031 { 1032 .fromsec = { "__ksymtab*", NULL }, 1033 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL }, 1034 .mismatch = EXPORT_TO_INIT_EXIT, 1035 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1036 } 1037 }; 1038 1039 static const struct sectioncheck *section_mismatch( 1040 const char *fromsec, const char *tosec) 1041 { 1042 int i; 1043 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck); 1044 const struct sectioncheck *check = §ioncheck[0]; 1045 1046 for (i = 0; i < elems; i++) { 1047 if (match(fromsec, check->fromsec) && 1048 match(tosec, check->tosec)) 1049 return check; 1050 check++; 1051 } 1052 return NULL; 1053 } 1054 1055 /** 1056 * Whitelist to allow certain references to pass with no warning. 1057 * 1058 * Pattern 1: 1059 * If a module parameter is declared __initdata and permissions=0 1060 * then this is legal despite the warning generated. 1061 * We cannot see value of permissions here, so just ignore 1062 * this pattern. 1063 * The pattern is identified by: 1064 * tosec = .init.data 1065 * fromsec = .data* 1066 * atsym =__param* 1067 * 1068 * Pattern 1a: 1069 * module_param_call() ops can refer to __init set function if permissions=0 1070 * The pattern is identified by: 1071 * tosec = .init.text 1072 * fromsec = .data* 1073 * atsym = __param_ops_* 1074 * 1075 * Pattern 2: 1076 * Many drivers utilise a *driver container with references to 1077 * add, remove, probe functions etc. 1078 * These functions may often be marked __devinit and we do not want to 1079 * warn here. 1080 * the pattern is identified by: 1081 * tosec = init or exit section 1082 * fromsec = data section 1083 * atsym = *driver, *_template, *_sht, *_ops, *_probe, 1084 * *probe_one, *_console, *_timer 1085 * 1086 * Pattern 3: 1087 * Whitelist all references from .head.text to any init section 1088 * 1089 * Pattern 4: 1090 * Some symbols belong to init section but still it is ok to reference 1091 * these from non-init sections as these symbols don't have any memory 1092 * allocated for them and symbol address and value are same. So even 1093 * if init section is freed, its ok to reference those symbols. 1094 * For ex. symbols marking the init section boundaries. 1095 * This pattern is identified by 1096 * refsymname = __init_begin, _sinittext, _einittext 1097 * 1098 **/ 1099 static int secref_whitelist(const struct sectioncheck *mismatch, 1100 const char *fromsec, const char *fromsym, 1101 const char *tosec, const char *tosym) 1102 { 1103 /* Check for pattern 1 */ 1104 if (match(tosec, init_data_sections) && 1105 match(fromsec, data_sections) && 1106 (strncmp(fromsym, "__param", strlen("__param")) == 0)) 1107 return 0; 1108 1109 /* Check for pattern 1a */ 1110 if (strcmp(tosec, ".init.text") == 0 && 1111 match(fromsec, data_sections) && 1112 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0)) 1113 return 0; 1114 1115 /* Check for pattern 2 */ 1116 if (match(tosec, init_exit_sections) && 1117 match(fromsec, data_sections) && 1118 match(fromsym, mismatch->symbol_white_list)) 1119 return 0; 1120 1121 /* Check for pattern 3 */ 1122 if (match(fromsec, head_sections) && 1123 match(tosec, init_sections)) 1124 return 0; 1125 1126 /* Check for pattern 4 */ 1127 if (match(tosym, linker_symbols)) 1128 return 0; 1129 1130 return 1; 1131 } 1132 1133 /** 1134 * Find symbol based on relocation record info. 1135 * In some cases the symbol supplied is a valid symbol so 1136 * return refsym. If st_name != 0 we assume this is a valid symbol. 1137 * In other cases the symbol needs to be looked up in the symbol table 1138 * based on section and address. 1139 * **/ 1140 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr, 1141 Elf_Sym *relsym) 1142 { 1143 Elf_Sym *sym; 1144 Elf_Sym *near = NULL; 1145 Elf64_Sword distance = 20; 1146 Elf64_Sword d; 1147 unsigned int relsym_secindex; 1148 1149 if (relsym->st_name != 0) 1150 return relsym; 1151 1152 relsym_secindex = get_secindex(elf, relsym); 1153 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1154 if (get_secindex(elf, sym) != relsym_secindex) 1155 continue; 1156 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) 1157 continue; 1158 if (sym->st_value == addr) 1159 return sym; 1160 /* Find a symbol nearby - addr are maybe negative */ 1161 d = sym->st_value - addr; 1162 if (d < 0) 1163 d = addr - sym->st_value; 1164 if (d < distance) { 1165 distance = d; 1166 near = sym; 1167 } 1168 } 1169 /* We need a close match */ 1170 if (distance < 20) 1171 return near; 1172 else 1173 return NULL; 1174 } 1175 1176 static inline int is_arm_mapping_symbol(const char *str) 1177 { 1178 return str[0] == '$' && strchr("atd", str[1]) 1179 && (str[2] == '\0' || str[2] == '.'); 1180 } 1181 1182 /* 1183 * If there's no name there, ignore it; likewise, ignore it if it's 1184 * one of the magic symbols emitted used by current ARM tools. 1185 * 1186 * Otherwise if find_symbols_between() returns those symbols, they'll 1187 * fail the whitelist tests and cause lots of false alarms ... fixable 1188 * only by merging __exit and __init sections into __text, bloating 1189 * the kernel (which is especially evil on embedded platforms). 1190 */ 1191 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 1192 { 1193 const char *name = elf->strtab + sym->st_name; 1194 1195 if (!name || !strlen(name)) 1196 return 0; 1197 return !is_arm_mapping_symbol(name); 1198 } 1199 1200 /* 1201 * Find symbols before or equal addr and after addr - in the section sec. 1202 * If we find two symbols with equal offset prefer one with a valid name. 1203 * The ELF format may have a better way to detect what type of symbol 1204 * it is, but this works for now. 1205 **/ 1206 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr, 1207 const char *sec) 1208 { 1209 Elf_Sym *sym; 1210 Elf_Sym *near = NULL; 1211 Elf_Addr distance = ~0; 1212 1213 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1214 const char *symsec; 1215 1216 if (is_shndx_special(sym->st_shndx)) 1217 continue; 1218 symsec = sec_name(elf, get_secindex(elf, sym)); 1219 if (strcmp(symsec, sec) != 0) 1220 continue; 1221 if (!is_valid_name(elf, sym)) 1222 continue; 1223 if (sym->st_value <= addr) { 1224 if ((addr - sym->st_value) < distance) { 1225 distance = addr - sym->st_value; 1226 near = sym; 1227 } else if ((addr - sym->st_value) == distance) { 1228 near = sym; 1229 } 1230 } 1231 } 1232 return near; 1233 } 1234 1235 /* 1236 * Convert a section name to the function/data attribute 1237 * .init.text => __init 1238 * .cpuinit.data => __cpudata 1239 * .memexitconst => __memconst 1240 * etc. 1241 * 1242 * The memory of returned value has been allocated on a heap. The user of this 1243 * method should free it after usage. 1244 */ 1245 static char *sec2annotation(const char *s) 1246 { 1247 if (match(s, init_exit_sections)) { 1248 char *p = malloc(20); 1249 char *r = p; 1250 1251 *p++ = '_'; 1252 *p++ = '_'; 1253 if (*s == '.') 1254 s++; 1255 while (*s && *s != '.') 1256 *p++ = *s++; 1257 *p = '\0'; 1258 if (*s == '.') 1259 s++; 1260 if (strstr(s, "rodata") != NULL) 1261 strcat(p, "const "); 1262 else if (strstr(s, "data") != NULL) 1263 strcat(p, "data "); 1264 else 1265 strcat(p, " "); 1266 return r; 1267 } else { 1268 return strdup(""); 1269 } 1270 } 1271 1272 static int is_function(Elf_Sym *sym) 1273 { 1274 if (sym) 1275 return ELF_ST_TYPE(sym->st_info) == STT_FUNC; 1276 else 1277 return -1; 1278 } 1279 1280 static void print_section_list(const char * const list[20]) 1281 { 1282 const char *const *s = list; 1283 1284 while (*s) { 1285 fprintf(stderr, "%s", *s); 1286 s++; 1287 if (*s) 1288 fprintf(stderr, ", "); 1289 } 1290 fprintf(stderr, "\n"); 1291 } 1292 1293 /* 1294 * Print a warning about a section mismatch. 1295 * Try to find symbols near it so user can find it. 1296 * Check whitelist before warning - it may be a false positive. 1297 */ 1298 static void report_sec_mismatch(const char *modname, 1299 const struct sectioncheck *mismatch, 1300 const char *fromsec, 1301 unsigned long long fromaddr, 1302 const char *fromsym, 1303 int from_is_func, 1304 const char *tosec, const char *tosym, 1305 int to_is_func) 1306 { 1307 const char *from, *from_p; 1308 const char *to, *to_p; 1309 char *prl_from; 1310 char *prl_to; 1311 1312 switch (from_is_func) { 1313 case 0: from = "variable"; from_p = ""; break; 1314 case 1: from = "function"; from_p = "()"; break; 1315 default: from = "(unknown reference)"; from_p = ""; break; 1316 } 1317 switch (to_is_func) { 1318 case 0: to = "variable"; to_p = ""; break; 1319 case 1: to = "function"; to_p = "()"; break; 1320 default: to = "(unknown reference)"; to_p = ""; break; 1321 } 1322 1323 sec_mismatch_count++; 1324 if (!sec_mismatch_verbose) 1325 return; 1326 1327 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s " 1328 "to the %s %s:%s%s\n", 1329 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec, 1330 tosym, to_p); 1331 1332 switch (mismatch->mismatch) { 1333 case TEXT_TO_ANY_INIT: 1334 prl_from = sec2annotation(fromsec); 1335 prl_to = sec2annotation(tosec); 1336 fprintf(stderr, 1337 "The function %s%s() references\n" 1338 "the %s %s%s%s.\n" 1339 "This is often because %s lacks a %s\n" 1340 "annotation or the annotation of %s is wrong.\n", 1341 prl_from, fromsym, 1342 to, prl_to, tosym, to_p, 1343 fromsym, prl_to, tosym); 1344 free(prl_from); 1345 free(prl_to); 1346 break; 1347 case DATA_TO_ANY_INIT: { 1348 prl_to = sec2annotation(tosec); 1349 fprintf(stderr, 1350 "The variable %s references\n" 1351 "the %s %s%s%s\n" 1352 "If the reference is valid then annotate the\n" 1353 "variable with __init* or __refdata (see linux/init.h) " 1354 "or name the variable:\n", 1355 fromsym, to, prl_to, tosym, to_p); 1356 print_section_list(mismatch->symbol_white_list); 1357 free(prl_to); 1358 break; 1359 } 1360 case TEXT_TO_ANY_EXIT: 1361 prl_to = sec2annotation(tosec); 1362 fprintf(stderr, 1363 "The function %s() references a %s in an exit section.\n" 1364 "Often the %s %s%s has valid usage outside the exit section\n" 1365 "and the fix is to remove the %sannotation of %s.\n", 1366 fromsym, to, to, tosym, to_p, prl_to, tosym); 1367 free(prl_to); 1368 break; 1369 case DATA_TO_ANY_EXIT: { 1370 prl_to = sec2annotation(tosec); 1371 fprintf(stderr, 1372 "The variable %s references\n" 1373 "the %s %s%s%s\n" 1374 "If the reference is valid then annotate the\n" 1375 "variable with __exit* (see linux/init.h) or " 1376 "name the variable:\n", 1377 fromsym, to, prl_to, tosym, to_p); 1378 print_section_list(mismatch->symbol_white_list); 1379 free(prl_to); 1380 break; 1381 } 1382 case XXXINIT_TO_SOME_INIT: 1383 case XXXEXIT_TO_SOME_EXIT: 1384 prl_from = sec2annotation(fromsec); 1385 prl_to = sec2annotation(tosec); 1386 fprintf(stderr, 1387 "The %s %s%s%s references\n" 1388 "a %s %s%s%s.\n" 1389 "If %s is only used by %s then\n" 1390 "annotate %s with a matching annotation.\n", 1391 from, prl_from, fromsym, from_p, 1392 to, prl_to, tosym, to_p, 1393 tosym, fromsym, tosym); 1394 free(prl_from); 1395 free(prl_to); 1396 break; 1397 case ANY_INIT_TO_ANY_EXIT: 1398 prl_from = sec2annotation(fromsec); 1399 prl_to = sec2annotation(tosec); 1400 fprintf(stderr, 1401 "The %s %s%s%s references\n" 1402 "a %s %s%s%s.\n" 1403 "This is often seen when error handling " 1404 "in the init function\n" 1405 "uses functionality in the exit path.\n" 1406 "The fix is often to remove the %sannotation of\n" 1407 "%s%s so it may be used outside an exit section.\n", 1408 from, prl_from, fromsym, from_p, 1409 to, prl_to, tosym, to_p, 1410 prl_to, tosym, to_p); 1411 free(prl_from); 1412 free(prl_to); 1413 break; 1414 case ANY_EXIT_TO_ANY_INIT: 1415 prl_from = sec2annotation(fromsec); 1416 prl_to = sec2annotation(tosec); 1417 fprintf(stderr, 1418 "The %s %s%s%s references\n" 1419 "a %s %s%s%s.\n" 1420 "This is often seen when error handling " 1421 "in the exit function\n" 1422 "uses functionality in the init path.\n" 1423 "The fix is often to remove the %sannotation of\n" 1424 "%s%s so it may be used outside an init section.\n", 1425 from, prl_from, fromsym, from_p, 1426 to, prl_to, tosym, to_p, 1427 prl_to, tosym, to_p); 1428 free(prl_from); 1429 free(prl_to); 1430 break; 1431 case EXPORT_TO_INIT_EXIT: 1432 prl_to = sec2annotation(tosec); 1433 fprintf(stderr, 1434 "The symbol %s is exported and annotated %s\n" 1435 "Fix this by removing the %sannotation of %s " 1436 "or drop the export.\n", 1437 tosym, prl_to, prl_to, tosym); 1438 free(prl_to); 1439 break; 1440 } 1441 fprintf(stderr, "\n"); 1442 } 1443 1444 static void check_section_mismatch(const char *modname, struct elf_info *elf, 1445 Elf_Rela *r, Elf_Sym *sym, const char *fromsec) 1446 { 1447 const char *tosec; 1448 const struct sectioncheck *mismatch; 1449 1450 tosec = sec_name(elf, get_secindex(elf, sym)); 1451 mismatch = section_mismatch(fromsec, tosec); 1452 if (mismatch) { 1453 Elf_Sym *to; 1454 Elf_Sym *from; 1455 const char *tosym; 1456 const char *fromsym; 1457 1458 from = find_elf_symbol2(elf, r->r_offset, fromsec); 1459 fromsym = sym_name(elf, from); 1460 to = find_elf_symbol(elf, r->r_addend, sym); 1461 tosym = sym_name(elf, to); 1462 1463 /* check whitelist - we may ignore it */ 1464 if (secref_whitelist(mismatch, 1465 fromsec, fromsym, tosec, tosym)) { 1466 report_sec_mismatch(modname, mismatch, 1467 fromsec, r->r_offset, fromsym, 1468 is_function(from), tosec, tosym, 1469 is_function(to)); 1470 } 1471 } 1472 } 1473 1474 static unsigned int *reloc_location(struct elf_info *elf, 1475 Elf_Shdr *sechdr, Elf_Rela *r) 1476 { 1477 Elf_Shdr *sechdrs = elf->sechdrs; 1478 int section = sechdr->sh_info; 1479 1480 return (void *)elf->hdr + sechdrs[section].sh_offset + 1481 r->r_offset; 1482 } 1483 1484 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1485 { 1486 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1487 unsigned int *location = reloc_location(elf, sechdr, r); 1488 1489 switch (r_typ) { 1490 case R_386_32: 1491 r->r_addend = TO_NATIVE(*location); 1492 break; 1493 case R_386_PC32: 1494 r->r_addend = TO_NATIVE(*location) + 4; 1495 /* For CONFIG_RELOCATABLE=y */ 1496 if (elf->hdr->e_type == ET_EXEC) 1497 r->r_addend += r->r_offset; 1498 break; 1499 } 1500 return 0; 1501 } 1502 1503 #ifndef R_ARM_CALL 1504 #define R_ARM_CALL 28 1505 #endif 1506 #ifndef R_ARM_JUMP24 1507 #define R_ARM_JUMP24 29 1508 #endif 1509 1510 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1511 { 1512 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1513 1514 switch (r_typ) { 1515 case R_ARM_ABS32: 1516 /* From ARM ABI: (S + A) | T */ 1517 r->r_addend = (int)(long) 1518 (elf->symtab_start + ELF_R_SYM(r->r_info)); 1519 break; 1520 case R_ARM_PC24: 1521 case R_ARM_CALL: 1522 case R_ARM_JUMP24: 1523 /* From ARM ABI: ((S + A) | T) - P */ 1524 r->r_addend = (int)(long)(elf->hdr + 1525 sechdr->sh_offset + 1526 (r->r_offset - sechdr->sh_addr)); 1527 break; 1528 default: 1529 return 1; 1530 } 1531 return 0; 1532 } 1533 1534 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1535 { 1536 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1537 unsigned int *location = reloc_location(elf, sechdr, r); 1538 unsigned int inst; 1539 1540 if (r_typ == R_MIPS_HI16) 1541 return 1; /* skip this */ 1542 inst = TO_NATIVE(*location); 1543 switch (r_typ) { 1544 case R_MIPS_LO16: 1545 r->r_addend = inst & 0xffff; 1546 break; 1547 case R_MIPS_26: 1548 r->r_addend = (inst & 0x03ffffff) << 2; 1549 break; 1550 case R_MIPS_32: 1551 r->r_addend = inst; 1552 break; 1553 } 1554 return 0; 1555 } 1556 1557 static void section_rela(const char *modname, struct elf_info *elf, 1558 Elf_Shdr *sechdr) 1559 { 1560 Elf_Sym *sym; 1561 Elf_Rela *rela; 1562 Elf_Rela r; 1563 unsigned int r_sym; 1564 const char *fromsec; 1565 1566 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; 1567 Elf_Rela *stop = (void *)start + sechdr->sh_size; 1568 1569 fromsec = sech_name(elf, sechdr); 1570 fromsec += strlen(".rela"); 1571 /* if from section (name) is know good then skip it */ 1572 if (match(fromsec, section_white_list)) 1573 return; 1574 1575 for (rela = start; rela < stop; rela++) { 1576 r.r_offset = TO_NATIVE(rela->r_offset); 1577 #if KERNEL_ELFCLASS == ELFCLASS64 1578 if (elf->hdr->e_machine == EM_MIPS) { 1579 unsigned int r_typ; 1580 r_sym = ELF64_MIPS_R_SYM(rela->r_info); 1581 r_sym = TO_NATIVE(r_sym); 1582 r_typ = ELF64_MIPS_R_TYPE(rela->r_info); 1583 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1584 } else { 1585 r.r_info = TO_NATIVE(rela->r_info); 1586 r_sym = ELF_R_SYM(r.r_info); 1587 } 1588 #else 1589 r.r_info = TO_NATIVE(rela->r_info); 1590 r_sym = ELF_R_SYM(r.r_info); 1591 #endif 1592 r.r_addend = TO_NATIVE(rela->r_addend); 1593 sym = elf->symtab_start + r_sym; 1594 /* Skip special sections */ 1595 if (is_shndx_special(sym->st_shndx)) 1596 continue; 1597 check_section_mismatch(modname, elf, &r, sym, fromsec); 1598 } 1599 } 1600 1601 static void section_rel(const char *modname, struct elf_info *elf, 1602 Elf_Shdr *sechdr) 1603 { 1604 Elf_Sym *sym; 1605 Elf_Rel *rel; 1606 Elf_Rela r; 1607 unsigned int r_sym; 1608 const char *fromsec; 1609 1610 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset; 1611 Elf_Rel *stop = (void *)start + sechdr->sh_size; 1612 1613 fromsec = sech_name(elf, sechdr); 1614 fromsec += strlen(".rel"); 1615 /* if from section (name) is know good then skip it */ 1616 if (match(fromsec, section_white_list)) 1617 return; 1618 1619 for (rel = start; rel < stop; rel++) { 1620 r.r_offset = TO_NATIVE(rel->r_offset); 1621 #if KERNEL_ELFCLASS == ELFCLASS64 1622 if (elf->hdr->e_machine == EM_MIPS) { 1623 unsigned int r_typ; 1624 r_sym = ELF64_MIPS_R_SYM(rel->r_info); 1625 r_sym = TO_NATIVE(r_sym); 1626 r_typ = ELF64_MIPS_R_TYPE(rel->r_info); 1627 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1628 } else { 1629 r.r_info = TO_NATIVE(rel->r_info); 1630 r_sym = ELF_R_SYM(r.r_info); 1631 } 1632 #else 1633 r.r_info = TO_NATIVE(rel->r_info); 1634 r_sym = ELF_R_SYM(r.r_info); 1635 #endif 1636 r.r_addend = 0; 1637 switch (elf->hdr->e_machine) { 1638 case EM_386: 1639 if (addend_386_rel(elf, sechdr, &r)) 1640 continue; 1641 break; 1642 case EM_ARM: 1643 if (addend_arm_rel(elf, sechdr, &r)) 1644 continue; 1645 break; 1646 case EM_MIPS: 1647 if (addend_mips_rel(elf, sechdr, &r)) 1648 continue; 1649 break; 1650 } 1651 sym = elf->symtab_start + r_sym; 1652 /* Skip special sections */ 1653 if (is_shndx_special(sym->st_shndx)) 1654 continue; 1655 check_section_mismatch(modname, elf, &r, sym, fromsec); 1656 } 1657 } 1658 1659 /** 1660 * A module includes a number of sections that are discarded 1661 * either when loaded or when used as built-in. 1662 * For loaded modules all functions marked __init and all data 1663 * marked __initdata will be discarded when the module has been initialized. 1664 * Likewise for modules used built-in the sections marked __exit 1665 * are discarded because __exit marked function are supposed to be called 1666 * only when a module is unloaded which never happens for built-in modules. 1667 * The check_sec_ref() function traverses all relocation records 1668 * to find all references to a section that reference a section that will 1669 * be discarded and warns about it. 1670 **/ 1671 static void check_sec_ref(struct module *mod, const char *modname, 1672 struct elf_info *elf) 1673 { 1674 int i; 1675 Elf_Shdr *sechdrs = elf->sechdrs; 1676 1677 /* Walk through all sections */ 1678 for (i = 0; i < elf->num_sections; i++) { 1679 check_section(modname, elf, &elf->sechdrs[i]); 1680 /* We want to process only relocation sections and not .init */ 1681 if (sechdrs[i].sh_type == SHT_RELA) 1682 section_rela(modname, elf, &elf->sechdrs[i]); 1683 else if (sechdrs[i].sh_type == SHT_REL) 1684 section_rel(modname, elf, &elf->sechdrs[i]); 1685 } 1686 } 1687 1688 static void read_symbols(char *modname) 1689 { 1690 const char *symname; 1691 char *version; 1692 char *license; 1693 struct module *mod; 1694 struct elf_info info = { }; 1695 Elf_Sym *sym; 1696 1697 if (!parse_elf(&info, modname)) 1698 return; 1699 1700 mod = new_module(modname); 1701 1702 /* When there's no vmlinux, don't print warnings about 1703 * unresolved symbols (since there'll be too many ;) */ 1704 if (is_vmlinux(modname)) { 1705 have_vmlinux = 1; 1706 mod->skip = 1; 1707 } 1708 1709 license = get_modinfo(info.modinfo, info.modinfo_len, "license"); 1710 if (info.modinfo && !license && !is_vmlinux(modname)) 1711 warn("modpost: missing MODULE_LICENSE() in %s\n" 1712 "see include/linux/module.h for " 1713 "more information\n", modname); 1714 while (license) { 1715 if (license_is_gpl_compatible(license)) 1716 mod->gpl_compatible = 1; 1717 else { 1718 mod->gpl_compatible = 0; 1719 break; 1720 } 1721 license = get_next_modinfo(info.modinfo, info.modinfo_len, 1722 "license", license); 1723 } 1724 1725 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1726 symname = info.strtab + sym->st_name; 1727 1728 handle_modversions(mod, &info, sym, symname); 1729 handle_moddevtable(mod, &info, sym, symname); 1730 } 1731 if (!is_vmlinux(modname) || 1732 (is_vmlinux(modname) && vmlinux_section_warnings)) 1733 check_sec_ref(mod, modname, &info); 1734 1735 version = get_modinfo(info.modinfo, info.modinfo_len, "version"); 1736 if (version) 1737 maybe_frob_rcs_version(modname, version, info.modinfo, 1738 version - (char *)info.hdr); 1739 if (version || (all_versions && !is_vmlinux(modname))) 1740 get_src_version(modname, mod->srcversion, 1741 sizeof(mod->srcversion)-1); 1742 1743 parse_elf_finish(&info); 1744 1745 /* Our trick to get versioning for module struct etc. - it's 1746 * never passed as an argument to an exported function, so 1747 * the automatic versioning doesn't pick it up, but it's really 1748 * important anyhow */ 1749 if (modversions) 1750 mod->unres = alloc_symbol("module_layout", 0, mod->unres); 1751 } 1752 1753 #define SZ 500 1754 1755 /* We first write the generated file into memory using the 1756 * following helper, then compare to the file on disk and 1757 * only update the later if anything changed */ 1758 1759 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1760 const char *fmt, ...) 1761 { 1762 char tmp[SZ]; 1763 int len; 1764 va_list ap; 1765 1766 va_start(ap, fmt); 1767 len = vsnprintf(tmp, SZ, fmt, ap); 1768 buf_write(buf, tmp, len); 1769 va_end(ap); 1770 } 1771 1772 void buf_write(struct buffer *buf, const char *s, int len) 1773 { 1774 if (buf->size - buf->pos < len) { 1775 buf->size += len + SZ; 1776 buf->p = realloc(buf->p, buf->size); 1777 } 1778 strncpy(buf->p + buf->pos, s, len); 1779 buf->pos += len; 1780 } 1781 1782 static void check_for_gpl_usage(enum export exp, const char *m, const char *s) 1783 { 1784 const char *e = is_vmlinux(m) ?"":".ko"; 1785 1786 switch (exp) { 1787 case export_gpl: 1788 fatal("modpost: GPL-incompatible module %s%s " 1789 "uses GPL-only symbol '%s'\n", m, e, s); 1790 break; 1791 case export_unused_gpl: 1792 fatal("modpost: GPL-incompatible module %s%s " 1793 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); 1794 break; 1795 case export_gpl_future: 1796 warn("modpost: GPL-incompatible module %s%s " 1797 "uses future GPL-only symbol '%s'\n", m, e, s); 1798 break; 1799 case export_plain: 1800 case export_unused: 1801 case export_unknown: 1802 /* ignore */ 1803 break; 1804 } 1805 } 1806 1807 static void check_for_unused(enum export exp, const char *m, const char *s) 1808 { 1809 const char *e = is_vmlinux(m) ?"":".ko"; 1810 1811 switch (exp) { 1812 case export_unused: 1813 case export_unused_gpl: 1814 warn("modpost: module %s%s " 1815 "uses symbol '%s' marked UNUSED\n", m, e, s); 1816 break; 1817 default: 1818 /* ignore */ 1819 break; 1820 } 1821 } 1822 1823 static void check_exports(struct module *mod) 1824 { 1825 struct symbol *s, *exp; 1826 1827 for (s = mod->unres; s; s = s->next) { 1828 const char *basename; 1829 exp = find_symbol(s->name); 1830 if (!exp || exp->module == mod) 1831 continue; 1832 basename = strrchr(mod->name, '/'); 1833 if (basename) 1834 basename++; 1835 else 1836 basename = mod->name; 1837 if (!mod->gpl_compatible) 1838 check_for_gpl_usage(exp->export, basename, exp->name); 1839 check_for_unused(exp->export, basename, exp->name); 1840 } 1841 } 1842 1843 /** 1844 * Header for the generated file 1845 **/ 1846 static void add_header(struct buffer *b, struct module *mod) 1847 { 1848 buf_printf(b, "#include <linux/module.h>\n"); 1849 buf_printf(b, "#include <linux/vermagic.h>\n"); 1850 buf_printf(b, "#include <linux/compiler.h>\n"); 1851 buf_printf(b, "\n"); 1852 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1853 buf_printf(b, "\n"); 1854 buf_printf(b, "struct module __this_module\n"); 1855 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); 1856 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1857 if (mod->has_init) 1858 buf_printf(b, "\t.init = init_module,\n"); 1859 if (mod->has_cleanup) 1860 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1861 "\t.exit = cleanup_module,\n" 1862 "#endif\n"); 1863 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1864 buf_printf(b, "};\n"); 1865 } 1866 1867 static void add_intree_flag(struct buffer *b, int is_intree) 1868 { 1869 if (is_intree) 1870 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1871 } 1872 1873 static void add_staging_flag(struct buffer *b, const char *name) 1874 { 1875 static const char *staging_dir = "drivers/staging"; 1876 1877 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0) 1878 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1879 } 1880 1881 /** 1882 * Record CRCs for unresolved symbols 1883 **/ 1884 static int add_versions(struct buffer *b, struct module *mod) 1885 { 1886 struct symbol *s, *exp; 1887 int err = 0; 1888 1889 for (s = mod->unres; s; s = s->next) { 1890 exp = find_symbol(s->name); 1891 if (!exp || exp->module == mod) { 1892 if (have_vmlinux && !s->weak) { 1893 if (warn_unresolved) { 1894 warn("\"%s\" [%s.ko] undefined!\n", 1895 s->name, mod->name); 1896 } else { 1897 merror("\"%s\" [%s.ko] undefined!\n", 1898 s->name, mod->name); 1899 err = 1; 1900 } 1901 } 1902 continue; 1903 } 1904 s->module = exp->module; 1905 s->crc_valid = exp->crc_valid; 1906 s->crc = exp->crc; 1907 } 1908 1909 if (!modversions) 1910 return err; 1911 1912 buf_printf(b, "\n"); 1913 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1914 buf_printf(b, "__used\n"); 1915 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); 1916 1917 for (s = mod->unres; s; s = s->next) { 1918 if (!s->module) 1919 continue; 1920 if (!s->crc_valid) { 1921 warn("\"%s\" [%s.ko] has no CRC!\n", 1922 s->name, mod->name); 1923 continue; 1924 } 1925 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); 1926 } 1927 1928 buf_printf(b, "};\n"); 1929 1930 return err; 1931 } 1932 1933 static void add_depends(struct buffer *b, struct module *mod, 1934 struct module *modules) 1935 { 1936 struct symbol *s; 1937 struct module *m; 1938 int first = 1; 1939 1940 for (m = modules; m; m = m->next) 1941 m->seen = is_vmlinux(m->name); 1942 1943 buf_printf(b, "\n"); 1944 buf_printf(b, "static const char __module_depends[]\n"); 1945 buf_printf(b, "__used\n"); 1946 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); 1947 buf_printf(b, "\"depends="); 1948 for (s = mod->unres; s; s = s->next) { 1949 const char *p; 1950 if (!s->module) 1951 continue; 1952 1953 if (s->module->seen) 1954 continue; 1955 1956 s->module->seen = 1; 1957 p = strrchr(s->module->name, '/'); 1958 if (p) 1959 p++; 1960 else 1961 p = s->module->name; 1962 buf_printf(b, "%s%s", first ? "" : ",", p); 1963 first = 0; 1964 } 1965 buf_printf(b, "\";\n"); 1966 } 1967 1968 static void add_srcversion(struct buffer *b, struct module *mod) 1969 { 1970 if (mod->srcversion[0]) { 1971 buf_printf(b, "\n"); 1972 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1973 mod->srcversion); 1974 } 1975 } 1976 1977 static void write_if_changed(struct buffer *b, const char *fname) 1978 { 1979 char *tmp; 1980 FILE *file; 1981 struct stat st; 1982 1983 file = fopen(fname, "r"); 1984 if (!file) 1985 goto write; 1986 1987 if (fstat(fileno(file), &st) < 0) 1988 goto close_write; 1989 1990 if (st.st_size != b->pos) 1991 goto close_write; 1992 1993 tmp = NOFAIL(malloc(b->pos)); 1994 if (fread(tmp, 1, b->pos, file) != b->pos) 1995 goto free_write; 1996 1997 if (memcmp(tmp, b->p, b->pos) != 0) 1998 goto free_write; 1999 2000 free(tmp); 2001 fclose(file); 2002 return; 2003 2004 free_write: 2005 free(tmp); 2006 close_write: 2007 fclose(file); 2008 write: 2009 file = fopen(fname, "w"); 2010 if (!file) { 2011 perror(fname); 2012 exit(1); 2013 } 2014 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2015 perror(fname); 2016 exit(1); 2017 } 2018 fclose(file); 2019 } 2020 2021 /* parse Module.symvers file. line format: 2022 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] 2023 **/ 2024 static void read_dump(const char *fname, unsigned int kernel) 2025 { 2026 unsigned long size, pos = 0; 2027 void *file = grab_file(fname, &size); 2028 char *line; 2029 2030 if (!file) 2031 /* No symbol versions, silently ignore */ 2032 return; 2033 2034 while ((line = get_next_line(&pos, file, size))) { 2035 char *symname, *modname, *d, *export, *end; 2036 unsigned int crc; 2037 struct module *mod; 2038 struct symbol *s; 2039 2040 if (!(symname = strchr(line, '\t'))) 2041 goto fail; 2042 *symname++ = '\0'; 2043 if (!(modname = strchr(symname, '\t'))) 2044 goto fail; 2045 *modname++ = '\0'; 2046 if ((export = strchr(modname, '\t')) != NULL) 2047 *export++ = '\0'; 2048 if (export && ((end = strchr(export, '\t')) != NULL)) 2049 *end = '\0'; 2050 crc = strtoul(line, &d, 16); 2051 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2052 goto fail; 2053 mod = find_module(modname); 2054 if (!mod) { 2055 if (is_vmlinux(modname)) 2056 have_vmlinux = 1; 2057 mod = new_module(modname); 2058 mod->skip = 1; 2059 } 2060 s = sym_add_exported(symname, mod, export_no(export)); 2061 s->kernel = kernel; 2062 s->preloaded = 1; 2063 sym_update_crc(symname, mod, crc, export_no(export)); 2064 } 2065 return; 2066 fail: 2067 fatal("parse error in symbol dump file\n"); 2068 } 2069 2070 /* For normal builds always dump all symbols. 2071 * For external modules only dump symbols 2072 * that are not read from kernel Module.symvers. 2073 **/ 2074 static int dump_sym(struct symbol *sym) 2075 { 2076 if (!external_module) 2077 return 1; 2078 if (sym->vmlinux || sym->kernel) 2079 return 0; 2080 return 1; 2081 } 2082 2083 static void write_dump(const char *fname) 2084 { 2085 struct buffer buf = { }; 2086 struct symbol *symbol; 2087 int n; 2088 2089 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { 2090 symbol = symbolhash[n]; 2091 while (symbol) { 2092 if (dump_sym(symbol)) 2093 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", 2094 symbol->crc, symbol->name, 2095 symbol->module->name, 2096 export_str(symbol->export)); 2097 symbol = symbol->next; 2098 } 2099 } 2100 write_if_changed(&buf, fname); 2101 } 2102 2103 struct ext_sym_list { 2104 struct ext_sym_list *next; 2105 const char *file; 2106 }; 2107 2108 int main(int argc, char **argv) 2109 { 2110 struct module *mod; 2111 struct buffer buf = { }; 2112 char *kernel_read = NULL, *module_read = NULL; 2113 char *dump_write = NULL; 2114 int opt; 2115 int err; 2116 struct ext_sym_list *extsym_iter; 2117 struct ext_sym_list *extsym_start = NULL; 2118 2119 while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) { 2120 switch (opt) { 2121 case 'i': 2122 kernel_read = optarg; 2123 break; 2124 case 'I': 2125 module_read = optarg; 2126 external_module = 1; 2127 break; 2128 case 'c': 2129 cross_build = 1; 2130 break; 2131 case 'e': 2132 external_module = 1; 2133 extsym_iter = 2134 NOFAIL(malloc(sizeof(*extsym_iter))); 2135 extsym_iter->next = extsym_start; 2136 extsym_iter->file = optarg; 2137 extsym_start = extsym_iter; 2138 break; 2139 case 'm': 2140 modversions = 1; 2141 break; 2142 case 'o': 2143 dump_write = optarg; 2144 break; 2145 case 'a': 2146 all_versions = 1; 2147 break; 2148 case 's': 2149 vmlinux_section_warnings = 0; 2150 break; 2151 case 'S': 2152 sec_mismatch_verbose = 0; 2153 break; 2154 case 'w': 2155 warn_unresolved = 1; 2156 break; 2157 default: 2158 exit(1); 2159 } 2160 } 2161 2162 if (kernel_read) 2163 read_dump(kernel_read, 1); 2164 if (module_read) 2165 read_dump(module_read, 0); 2166 while (extsym_start) { 2167 read_dump(extsym_start->file, 0); 2168 extsym_iter = extsym_start->next; 2169 free(extsym_start); 2170 extsym_start = extsym_iter; 2171 } 2172 2173 while (optind < argc) 2174 read_symbols(argv[optind++]); 2175 2176 for (mod = modules; mod; mod = mod->next) { 2177 if (mod->skip) 2178 continue; 2179 check_exports(mod); 2180 } 2181 2182 err = 0; 2183 2184 for (mod = modules; mod; mod = mod->next) { 2185 char fname[strlen(mod->name) + 10]; 2186 2187 if (mod->skip) 2188 continue; 2189 2190 buf.pos = 0; 2191 2192 add_header(&buf, mod); 2193 add_intree_flag(&buf, !external_module); 2194 add_staging_flag(&buf, mod->name); 2195 err |= add_versions(&buf, mod); 2196 add_depends(&buf, mod, modules); 2197 add_moddevtable(&buf, mod); 2198 add_srcversion(&buf, mod); 2199 2200 sprintf(fname, "%s.mod.c", mod->name); 2201 write_if_changed(&buf, fname); 2202 } 2203 2204 if (dump_write) 2205 write_dump(dump_write); 2206 if (sec_mismatch_count && !sec_mismatch_verbose) 2207 warn("modpost: Found %d section mismatch(es).\n" 2208 "To see full details build your kernel with:\n" 2209 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n", 2210 sec_mismatch_count); 2211 2212 return err; 2213 } 2214