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 ".GCC.command.line", /* record-gcc-switches, non mn10300 */ 825 ".mdebug*", /* alpha, score, mips etc. */ 826 ".pdr", /* alpha, score, mips etc. */ 827 ".stab*", 828 ".note*", 829 ".got*", 830 ".toc*", 831 ".xt.prop", /* xtensa */ 832 ".xt.lit", /* xtensa */ 833 NULL 834 }; 835 836 /* 837 * This is used to find sections missing the SHF_ALLOC flag. 838 * The cause of this is often a section specified in assembler 839 * without "ax" / "aw". 840 */ 841 static void check_section(const char *modname, struct elf_info *elf, 842 Elf_Shdr *sechdr) 843 { 844 const char *sec = sech_name(elf, sechdr); 845 846 if (sechdr->sh_type == SHT_PROGBITS && 847 !(sechdr->sh_flags & SHF_ALLOC) && 848 !match(sec, section_white_list)) { 849 warn("%s (%s): unexpected non-allocatable section.\n" 850 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 851 "Note that for example <linux/init.h> contains\n" 852 "section definitions for use in .S files.\n\n", 853 modname, sec); 854 } 855 } 856 857 858 859 #define ALL_INIT_DATA_SECTIONS \ 860 ".init.setup$", ".init.rodata$", \ 861 ".cpuinit.rodata$", ".meminit.rodata$", \ 862 ".init.data$", ".cpuinit.data$", ".meminit.data$" 863 #define ALL_EXIT_DATA_SECTIONS \ 864 ".exit.data$", ".cpuexit.data$", ".memexit.data$" 865 866 #define ALL_INIT_TEXT_SECTIONS \ 867 ".init.text$", ".cpuinit.text$", ".meminit.text$" 868 #define ALL_EXIT_TEXT_SECTIONS \ 869 ".exit.text$", ".cpuexit.text$", ".memexit.text$" 870 871 #define ALL_PCI_INIT_SECTIONS \ 872 ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \ 873 ".pci_fixup_enable$", ".pci_fixup_resume$", \ 874 ".pci_fixup_resume_early$", ".pci_fixup_suspend$" 875 876 #define ALL_XXXINIT_SECTIONS CPU_INIT_SECTIONS, MEM_INIT_SECTIONS 877 #define ALL_XXXEXIT_SECTIONS CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS 878 879 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 880 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS 881 882 #define DATA_SECTIONS ".data$", ".data.rel$" 883 #define TEXT_SECTIONS ".text$" 884 885 #define INIT_SECTIONS ".init.*" 886 #define CPU_INIT_SECTIONS ".cpuinit.*" 887 #define MEM_INIT_SECTIONS ".meminit.*" 888 889 #define EXIT_SECTIONS ".exit.*" 890 #define CPU_EXIT_SECTIONS ".cpuexit.*" 891 #define MEM_EXIT_SECTIONS ".memexit.*" 892 893 /* init data sections */ 894 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL }; 895 896 /* all init sections */ 897 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL }; 898 899 /* All init and exit sections (code + data) */ 900 static const char *init_exit_sections[] = 901 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }; 902 903 /* data section */ 904 static const char *data_sections[] = { DATA_SECTIONS, NULL }; 905 906 907 /* symbols in .data that may refer to init/exit sections */ 908 #define DEFAULT_SYMBOL_WHITE_LIST \ 909 "*driver", \ 910 "*_template", /* scsi uses *_template a lot */ \ 911 "*_timer", /* arm uses ops structures named _timer a lot */ \ 912 "*_sht", /* scsi also used *_sht to some extent */ \ 913 "*_ops", \ 914 "*_probe", \ 915 "*_probe_one", \ 916 "*_console" 917 918 static const char *head_sections[] = { ".head.text*", NULL }; 919 static const char *linker_symbols[] = 920 { "__init_begin", "_sinittext", "_einittext", NULL }; 921 922 enum mismatch { 923 TEXT_TO_ANY_INIT, 924 DATA_TO_ANY_INIT, 925 TEXT_TO_ANY_EXIT, 926 DATA_TO_ANY_EXIT, 927 XXXINIT_TO_SOME_INIT, 928 XXXEXIT_TO_SOME_EXIT, 929 ANY_INIT_TO_ANY_EXIT, 930 ANY_EXIT_TO_ANY_INIT, 931 EXPORT_TO_INIT_EXIT, 932 }; 933 934 struct sectioncheck { 935 const char *fromsec[20]; 936 const char *tosec[20]; 937 enum mismatch mismatch; 938 const char *symbol_white_list[20]; 939 }; 940 941 const struct sectioncheck sectioncheck[] = { 942 /* Do not reference init/exit code/data from 943 * normal code and data 944 */ 945 { 946 .fromsec = { TEXT_SECTIONS, NULL }, 947 .tosec = { ALL_INIT_SECTIONS, NULL }, 948 .mismatch = TEXT_TO_ANY_INIT, 949 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 950 }, 951 { 952 .fromsec = { DATA_SECTIONS, NULL }, 953 .tosec = { ALL_XXXINIT_SECTIONS, NULL }, 954 .mismatch = DATA_TO_ANY_INIT, 955 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 956 }, 957 { 958 .fromsec = { DATA_SECTIONS, NULL }, 959 .tosec = { INIT_SECTIONS, NULL }, 960 .mismatch = DATA_TO_ANY_INIT, 961 .symbol_white_list = { 962 "*_template", "*_timer", "*_sht", "*_ops", 963 "*_probe", "*_probe_one", "*_console", NULL 964 }, 965 }, 966 { 967 .fromsec = { TEXT_SECTIONS, NULL }, 968 .tosec = { ALL_EXIT_SECTIONS, NULL }, 969 .mismatch = TEXT_TO_ANY_EXIT, 970 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 971 }, 972 { 973 .fromsec = { DATA_SECTIONS, NULL }, 974 .tosec = { ALL_EXIT_SECTIONS, NULL }, 975 .mismatch = DATA_TO_ANY_EXIT, 976 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 977 }, 978 /* Do not reference init code/data from cpuinit/meminit code/data */ 979 { 980 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 981 .tosec = { INIT_SECTIONS, NULL }, 982 .mismatch = XXXINIT_TO_SOME_INIT, 983 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 984 }, 985 /* Do not reference cpuinit code/data from meminit code/data */ 986 { 987 .fromsec = { MEM_INIT_SECTIONS, NULL }, 988 .tosec = { CPU_INIT_SECTIONS, NULL }, 989 .mismatch = XXXINIT_TO_SOME_INIT, 990 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 991 }, 992 /* Do not reference meminit code/data from cpuinit code/data */ 993 { 994 .fromsec = { CPU_INIT_SECTIONS, NULL }, 995 .tosec = { MEM_INIT_SECTIONS, NULL }, 996 .mismatch = XXXINIT_TO_SOME_INIT, 997 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 998 }, 999 /* Do not reference exit code/data from cpuexit/memexit code/data */ 1000 { 1001 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL }, 1002 .tosec = { EXIT_SECTIONS, NULL }, 1003 .mismatch = XXXEXIT_TO_SOME_EXIT, 1004 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1005 }, 1006 /* Do not reference cpuexit code/data from memexit code/data */ 1007 { 1008 .fromsec = { MEM_EXIT_SECTIONS, NULL }, 1009 .tosec = { CPU_EXIT_SECTIONS, NULL }, 1010 .mismatch = XXXEXIT_TO_SOME_EXIT, 1011 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1012 }, 1013 /* Do not reference memexit code/data from cpuexit code/data */ 1014 { 1015 .fromsec = { CPU_EXIT_SECTIONS, NULL }, 1016 .tosec = { MEM_EXIT_SECTIONS, NULL }, 1017 .mismatch = XXXEXIT_TO_SOME_EXIT, 1018 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1019 }, 1020 /* Do not use exit code/data from init code */ 1021 { 1022 .fromsec = { ALL_INIT_SECTIONS, NULL }, 1023 .tosec = { ALL_EXIT_SECTIONS, NULL }, 1024 .mismatch = ANY_INIT_TO_ANY_EXIT, 1025 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1026 }, 1027 /* Do not use init code/data from exit code */ 1028 { 1029 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 1030 .tosec = { ALL_INIT_SECTIONS, NULL }, 1031 .mismatch = ANY_EXIT_TO_ANY_INIT, 1032 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1033 }, 1034 { 1035 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 1036 .tosec = { INIT_SECTIONS, NULL }, 1037 .mismatch = ANY_INIT_TO_ANY_EXIT, 1038 .symbol_white_list = { NULL }, 1039 }, 1040 /* Do not export init/exit functions or data */ 1041 { 1042 .fromsec = { "__ksymtab*", NULL }, 1043 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL }, 1044 .mismatch = EXPORT_TO_INIT_EXIT, 1045 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1046 } 1047 }; 1048 1049 static const struct sectioncheck *section_mismatch( 1050 const char *fromsec, const char *tosec) 1051 { 1052 int i; 1053 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck); 1054 const struct sectioncheck *check = §ioncheck[0]; 1055 1056 for (i = 0; i < elems; i++) { 1057 if (match(fromsec, check->fromsec) && 1058 match(tosec, check->tosec)) 1059 return check; 1060 check++; 1061 } 1062 return NULL; 1063 } 1064 1065 /** 1066 * Whitelist to allow certain references to pass with no warning. 1067 * 1068 * Pattern 1: 1069 * If a module parameter is declared __initdata and permissions=0 1070 * then this is legal despite the warning generated. 1071 * We cannot see value of permissions here, so just ignore 1072 * this pattern. 1073 * The pattern is identified by: 1074 * tosec = .init.data 1075 * fromsec = .data* 1076 * atsym =__param* 1077 * 1078 * Pattern 1a: 1079 * module_param_call() ops can refer to __init set function if permissions=0 1080 * The pattern is identified by: 1081 * tosec = .init.text 1082 * fromsec = .data* 1083 * atsym = __param_ops_* 1084 * 1085 * Pattern 2: 1086 * Many drivers utilise a *driver container with references to 1087 * add, remove, probe functions etc. 1088 * These functions may often be marked __cpuinit and we do not want to 1089 * warn here. 1090 * the pattern is identified by: 1091 * tosec = init or exit section 1092 * fromsec = data section 1093 * atsym = *driver, *_template, *_sht, *_ops, *_probe, 1094 * *probe_one, *_console, *_timer 1095 * 1096 * Pattern 3: 1097 * Whitelist all references from .head.text to any init section 1098 * 1099 * Pattern 4: 1100 * Some symbols belong to init section but still it is ok to reference 1101 * these from non-init sections as these symbols don't have any memory 1102 * allocated for them and symbol address and value are same. So even 1103 * if init section is freed, its ok to reference those symbols. 1104 * For ex. symbols marking the init section boundaries. 1105 * This pattern is identified by 1106 * refsymname = __init_begin, _sinittext, _einittext 1107 * 1108 **/ 1109 static int secref_whitelist(const struct sectioncheck *mismatch, 1110 const char *fromsec, const char *fromsym, 1111 const char *tosec, const char *tosym) 1112 { 1113 /* Check for pattern 1 */ 1114 if (match(tosec, init_data_sections) && 1115 match(fromsec, data_sections) && 1116 (strncmp(fromsym, "__param", strlen("__param")) == 0)) 1117 return 0; 1118 1119 /* Check for pattern 1a */ 1120 if (strcmp(tosec, ".init.text") == 0 && 1121 match(fromsec, data_sections) && 1122 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0)) 1123 return 0; 1124 1125 /* Check for pattern 2 */ 1126 if (match(tosec, init_exit_sections) && 1127 match(fromsec, data_sections) && 1128 match(fromsym, mismatch->symbol_white_list)) 1129 return 0; 1130 1131 /* Check for pattern 3 */ 1132 if (match(fromsec, head_sections) && 1133 match(tosec, init_sections)) 1134 return 0; 1135 1136 /* Check for pattern 4 */ 1137 if (match(tosym, linker_symbols)) 1138 return 0; 1139 1140 return 1; 1141 } 1142 1143 /** 1144 * Find symbol based on relocation record info. 1145 * In some cases the symbol supplied is a valid symbol so 1146 * return refsym. If st_name != 0 we assume this is a valid symbol. 1147 * In other cases the symbol needs to be looked up in the symbol table 1148 * based on section and address. 1149 * **/ 1150 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr, 1151 Elf_Sym *relsym) 1152 { 1153 Elf_Sym *sym; 1154 Elf_Sym *near = NULL; 1155 Elf64_Sword distance = 20; 1156 Elf64_Sword d; 1157 unsigned int relsym_secindex; 1158 1159 if (relsym->st_name != 0) 1160 return relsym; 1161 1162 relsym_secindex = get_secindex(elf, relsym); 1163 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1164 if (get_secindex(elf, sym) != relsym_secindex) 1165 continue; 1166 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) 1167 continue; 1168 if (sym->st_value == addr) 1169 return sym; 1170 /* Find a symbol nearby - addr are maybe negative */ 1171 d = sym->st_value - addr; 1172 if (d < 0) 1173 d = addr - sym->st_value; 1174 if (d < distance) { 1175 distance = d; 1176 near = sym; 1177 } 1178 } 1179 /* We need a close match */ 1180 if (distance < 20) 1181 return near; 1182 else 1183 return NULL; 1184 } 1185 1186 static inline int is_arm_mapping_symbol(const char *str) 1187 { 1188 return str[0] == '$' && strchr("atd", str[1]) 1189 && (str[2] == '\0' || str[2] == '.'); 1190 } 1191 1192 /* 1193 * If there's no name there, ignore it; likewise, ignore it if it's 1194 * one of the magic symbols emitted used by current ARM tools. 1195 * 1196 * Otherwise if find_symbols_between() returns those symbols, they'll 1197 * fail the whitelist tests and cause lots of false alarms ... fixable 1198 * only by merging __exit and __init sections into __text, bloating 1199 * the kernel (which is especially evil on embedded platforms). 1200 */ 1201 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 1202 { 1203 const char *name = elf->strtab + sym->st_name; 1204 1205 if (!name || !strlen(name)) 1206 return 0; 1207 return !is_arm_mapping_symbol(name); 1208 } 1209 1210 /* 1211 * Find symbols before or equal addr and after addr - in the section sec. 1212 * If we find two symbols with equal offset prefer one with a valid name. 1213 * The ELF format may have a better way to detect what type of symbol 1214 * it is, but this works for now. 1215 **/ 1216 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr, 1217 const char *sec) 1218 { 1219 Elf_Sym *sym; 1220 Elf_Sym *near = NULL; 1221 Elf_Addr distance = ~0; 1222 1223 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1224 const char *symsec; 1225 1226 if (is_shndx_special(sym->st_shndx)) 1227 continue; 1228 symsec = sec_name(elf, get_secindex(elf, sym)); 1229 if (strcmp(symsec, sec) != 0) 1230 continue; 1231 if (!is_valid_name(elf, sym)) 1232 continue; 1233 if (sym->st_value <= addr) { 1234 if ((addr - sym->st_value) < distance) { 1235 distance = addr - sym->st_value; 1236 near = sym; 1237 } else if ((addr - sym->st_value) == distance) { 1238 near = sym; 1239 } 1240 } 1241 } 1242 return near; 1243 } 1244 1245 /* 1246 * Convert a section name to the function/data attribute 1247 * .init.text => __init 1248 * .cpuinit.data => __cpudata 1249 * .memexitconst => __memconst 1250 * etc. 1251 * 1252 * The memory of returned value has been allocated on a heap. The user of this 1253 * method should free it after usage. 1254 */ 1255 static char *sec2annotation(const char *s) 1256 { 1257 if (match(s, init_exit_sections)) { 1258 char *p = malloc(20); 1259 char *r = p; 1260 1261 *p++ = '_'; 1262 *p++ = '_'; 1263 if (*s == '.') 1264 s++; 1265 while (*s && *s != '.') 1266 *p++ = *s++; 1267 *p = '\0'; 1268 if (*s == '.') 1269 s++; 1270 if (strstr(s, "rodata") != NULL) 1271 strcat(p, "const "); 1272 else if (strstr(s, "data") != NULL) 1273 strcat(p, "data "); 1274 else 1275 strcat(p, " "); 1276 return r; 1277 } else { 1278 return strdup(""); 1279 } 1280 } 1281 1282 static int is_function(Elf_Sym *sym) 1283 { 1284 if (sym) 1285 return ELF_ST_TYPE(sym->st_info) == STT_FUNC; 1286 else 1287 return -1; 1288 } 1289 1290 static void print_section_list(const char * const list[20]) 1291 { 1292 const char *const *s = list; 1293 1294 while (*s) { 1295 fprintf(stderr, "%s", *s); 1296 s++; 1297 if (*s) 1298 fprintf(stderr, ", "); 1299 } 1300 fprintf(stderr, "\n"); 1301 } 1302 1303 /* 1304 * Print a warning about a section mismatch. 1305 * Try to find symbols near it so user can find it. 1306 * Check whitelist before warning - it may be a false positive. 1307 */ 1308 static void report_sec_mismatch(const char *modname, 1309 const struct sectioncheck *mismatch, 1310 const char *fromsec, 1311 unsigned long long fromaddr, 1312 const char *fromsym, 1313 int from_is_func, 1314 const char *tosec, const char *tosym, 1315 int to_is_func) 1316 { 1317 const char *from, *from_p; 1318 const char *to, *to_p; 1319 char *prl_from; 1320 char *prl_to; 1321 1322 switch (from_is_func) { 1323 case 0: from = "variable"; from_p = ""; break; 1324 case 1: from = "function"; from_p = "()"; break; 1325 default: from = "(unknown reference)"; from_p = ""; break; 1326 } 1327 switch (to_is_func) { 1328 case 0: to = "variable"; to_p = ""; break; 1329 case 1: to = "function"; to_p = "()"; break; 1330 default: to = "(unknown reference)"; to_p = ""; break; 1331 } 1332 1333 sec_mismatch_count++; 1334 if (!sec_mismatch_verbose) 1335 return; 1336 1337 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s " 1338 "to the %s %s:%s%s\n", 1339 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec, 1340 tosym, to_p); 1341 1342 switch (mismatch->mismatch) { 1343 case TEXT_TO_ANY_INIT: 1344 prl_from = sec2annotation(fromsec); 1345 prl_to = sec2annotation(tosec); 1346 fprintf(stderr, 1347 "The function %s%s() references\n" 1348 "the %s %s%s%s.\n" 1349 "This is often because %s lacks a %s\n" 1350 "annotation or the annotation of %s is wrong.\n", 1351 prl_from, fromsym, 1352 to, prl_to, tosym, to_p, 1353 fromsym, prl_to, tosym); 1354 free(prl_from); 1355 free(prl_to); 1356 break; 1357 case DATA_TO_ANY_INIT: { 1358 prl_to = sec2annotation(tosec); 1359 fprintf(stderr, 1360 "The variable %s references\n" 1361 "the %s %s%s%s\n" 1362 "If the reference is valid then annotate the\n" 1363 "variable with __init* or __refdata (see linux/init.h) " 1364 "or name the variable:\n", 1365 fromsym, to, prl_to, tosym, to_p); 1366 print_section_list(mismatch->symbol_white_list); 1367 free(prl_to); 1368 break; 1369 } 1370 case TEXT_TO_ANY_EXIT: 1371 prl_to = sec2annotation(tosec); 1372 fprintf(stderr, 1373 "The function %s() references a %s in an exit section.\n" 1374 "Often the %s %s%s has valid usage outside the exit section\n" 1375 "and the fix is to remove the %sannotation of %s.\n", 1376 fromsym, to, to, tosym, to_p, prl_to, tosym); 1377 free(prl_to); 1378 break; 1379 case DATA_TO_ANY_EXIT: { 1380 prl_to = sec2annotation(tosec); 1381 fprintf(stderr, 1382 "The variable %s references\n" 1383 "the %s %s%s%s\n" 1384 "If the reference is valid then annotate the\n" 1385 "variable with __exit* (see linux/init.h) or " 1386 "name the variable:\n", 1387 fromsym, to, prl_to, tosym, to_p); 1388 print_section_list(mismatch->symbol_white_list); 1389 free(prl_to); 1390 break; 1391 } 1392 case XXXINIT_TO_SOME_INIT: 1393 case XXXEXIT_TO_SOME_EXIT: 1394 prl_from = sec2annotation(fromsec); 1395 prl_to = sec2annotation(tosec); 1396 fprintf(stderr, 1397 "The %s %s%s%s references\n" 1398 "a %s %s%s%s.\n" 1399 "If %s is only used by %s then\n" 1400 "annotate %s with a matching annotation.\n", 1401 from, prl_from, fromsym, from_p, 1402 to, prl_to, tosym, to_p, 1403 tosym, fromsym, tosym); 1404 free(prl_from); 1405 free(prl_to); 1406 break; 1407 case ANY_INIT_TO_ANY_EXIT: 1408 prl_from = sec2annotation(fromsec); 1409 prl_to = sec2annotation(tosec); 1410 fprintf(stderr, 1411 "The %s %s%s%s references\n" 1412 "a %s %s%s%s.\n" 1413 "This is often seen when error handling " 1414 "in the init function\n" 1415 "uses functionality in the exit path.\n" 1416 "The fix is often to remove the %sannotation of\n" 1417 "%s%s so it may be used outside an exit section.\n", 1418 from, prl_from, fromsym, from_p, 1419 to, prl_to, tosym, to_p, 1420 prl_to, tosym, to_p); 1421 free(prl_from); 1422 free(prl_to); 1423 break; 1424 case ANY_EXIT_TO_ANY_INIT: 1425 prl_from = sec2annotation(fromsec); 1426 prl_to = sec2annotation(tosec); 1427 fprintf(stderr, 1428 "The %s %s%s%s references\n" 1429 "a %s %s%s%s.\n" 1430 "This is often seen when error handling " 1431 "in the exit function\n" 1432 "uses functionality in the init path.\n" 1433 "The fix is often to remove the %sannotation of\n" 1434 "%s%s so it may be used outside an init section.\n", 1435 from, prl_from, fromsym, from_p, 1436 to, prl_to, tosym, to_p, 1437 prl_to, tosym, to_p); 1438 free(prl_from); 1439 free(prl_to); 1440 break; 1441 case EXPORT_TO_INIT_EXIT: 1442 prl_to = sec2annotation(tosec); 1443 fprintf(stderr, 1444 "The symbol %s is exported and annotated %s\n" 1445 "Fix this by removing the %sannotation of %s " 1446 "or drop the export.\n", 1447 tosym, prl_to, prl_to, tosym); 1448 free(prl_to); 1449 break; 1450 } 1451 fprintf(stderr, "\n"); 1452 } 1453 1454 static void check_section_mismatch(const char *modname, struct elf_info *elf, 1455 Elf_Rela *r, Elf_Sym *sym, const char *fromsec) 1456 { 1457 const char *tosec; 1458 const struct sectioncheck *mismatch; 1459 1460 tosec = sec_name(elf, get_secindex(elf, sym)); 1461 mismatch = section_mismatch(fromsec, tosec); 1462 if (mismatch) { 1463 Elf_Sym *to; 1464 Elf_Sym *from; 1465 const char *tosym; 1466 const char *fromsym; 1467 1468 from = find_elf_symbol2(elf, r->r_offset, fromsec); 1469 fromsym = sym_name(elf, from); 1470 to = find_elf_symbol(elf, r->r_addend, sym); 1471 tosym = sym_name(elf, to); 1472 1473 /* check whitelist - we may ignore it */ 1474 if (secref_whitelist(mismatch, 1475 fromsec, fromsym, tosec, tosym)) { 1476 report_sec_mismatch(modname, mismatch, 1477 fromsec, r->r_offset, fromsym, 1478 is_function(from), tosec, tosym, 1479 is_function(to)); 1480 } 1481 } 1482 } 1483 1484 static unsigned int *reloc_location(struct elf_info *elf, 1485 Elf_Shdr *sechdr, Elf_Rela *r) 1486 { 1487 Elf_Shdr *sechdrs = elf->sechdrs; 1488 int section = sechdr->sh_info; 1489 1490 return (void *)elf->hdr + sechdrs[section].sh_offset + 1491 r->r_offset; 1492 } 1493 1494 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1495 { 1496 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1497 unsigned int *location = reloc_location(elf, sechdr, r); 1498 1499 switch (r_typ) { 1500 case R_386_32: 1501 r->r_addend = TO_NATIVE(*location); 1502 break; 1503 case R_386_PC32: 1504 r->r_addend = TO_NATIVE(*location) + 4; 1505 /* For CONFIG_RELOCATABLE=y */ 1506 if (elf->hdr->e_type == ET_EXEC) 1507 r->r_addend += r->r_offset; 1508 break; 1509 } 1510 return 0; 1511 } 1512 1513 #ifndef R_ARM_CALL 1514 #define R_ARM_CALL 28 1515 #endif 1516 #ifndef R_ARM_JUMP24 1517 #define R_ARM_JUMP24 29 1518 #endif 1519 1520 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1521 { 1522 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1523 1524 switch (r_typ) { 1525 case R_ARM_ABS32: 1526 /* From ARM ABI: (S + A) | T */ 1527 r->r_addend = (int)(long) 1528 (elf->symtab_start + ELF_R_SYM(r->r_info)); 1529 break; 1530 case R_ARM_PC24: 1531 case R_ARM_CALL: 1532 case R_ARM_JUMP24: 1533 /* From ARM ABI: ((S + A) | T) - P */ 1534 r->r_addend = (int)(long)(elf->hdr + 1535 sechdr->sh_offset + 1536 (r->r_offset - sechdr->sh_addr)); 1537 break; 1538 default: 1539 return 1; 1540 } 1541 return 0; 1542 } 1543 1544 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1545 { 1546 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1547 unsigned int *location = reloc_location(elf, sechdr, r); 1548 unsigned int inst; 1549 1550 if (r_typ == R_MIPS_HI16) 1551 return 1; /* skip this */ 1552 inst = TO_NATIVE(*location); 1553 switch (r_typ) { 1554 case R_MIPS_LO16: 1555 r->r_addend = inst & 0xffff; 1556 break; 1557 case R_MIPS_26: 1558 r->r_addend = (inst & 0x03ffffff) << 2; 1559 break; 1560 case R_MIPS_32: 1561 r->r_addend = inst; 1562 break; 1563 } 1564 return 0; 1565 } 1566 1567 static void section_rela(const char *modname, struct elf_info *elf, 1568 Elf_Shdr *sechdr) 1569 { 1570 Elf_Sym *sym; 1571 Elf_Rela *rela; 1572 Elf_Rela r; 1573 unsigned int r_sym; 1574 const char *fromsec; 1575 1576 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; 1577 Elf_Rela *stop = (void *)start + sechdr->sh_size; 1578 1579 fromsec = sech_name(elf, sechdr); 1580 fromsec += strlen(".rela"); 1581 /* if from section (name) is know good then skip it */ 1582 if (match(fromsec, section_white_list)) 1583 return; 1584 1585 for (rela = start; rela < stop; rela++) { 1586 r.r_offset = TO_NATIVE(rela->r_offset); 1587 #if KERNEL_ELFCLASS == ELFCLASS64 1588 if (elf->hdr->e_machine == EM_MIPS) { 1589 unsigned int r_typ; 1590 r_sym = ELF64_MIPS_R_SYM(rela->r_info); 1591 r_sym = TO_NATIVE(r_sym); 1592 r_typ = ELF64_MIPS_R_TYPE(rela->r_info); 1593 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1594 } else { 1595 r.r_info = TO_NATIVE(rela->r_info); 1596 r_sym = ELF_R_SYM(r.r_info); 1597 } 1598 #else 1599 r.r_info = TO_NATIVE(rela->r_info); 1600 r_sym = ELF_R_SYM(r.r_info); 1601 #endif 1602 r.r_addend = TO_NATIVE(rela->r_addend); 1603 sym = elf->symtab_start + r_sym; 1604 /* Skip special sections */ 1605 if (is_shndx_special(sym->st_shndx)) 1606 continue; 1607 check_section_mismatch(modname, elf, &r, sym, fromsec); 1608 } 1609 } 1610 1611 static void section_rel(const char *modname, struct elf_info *elf, 1612 Elf_Shdr *sechdr) 1613 { 1614 Elf_Sym *sym; 1615 Elf_Rel *rel; 1616 Elf_Rela r; 1617 unsigned int r_sym; 1618 const char *fromsec; 1619 1620 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset; 1621 Elf_Rel *stop = (void *)start + sechdr->sh_size; 1622 1623 fromsec = sech_name(elf, sechdr); 1624 fromsec += strlen(".rel"); 1625 /* if from section (name) is know good then skip it */ 1626 if (match(fromsec, section_white_list)) 1627 return; 1628 1629 for (rel = start; rel < stop; rel++) { 1630 r.r_offset = TO_NATIVE(rel->r_offset); 1631 #if KERNEL_ELFCLASS == ELFCLASS64 1632 if (elf->hdr->e_machine == EM_MIPS) { 1633 unsigned int r_typ; 1634 r_sym = ELF64_MIPS_R_SYM(rel->r_info); 1635 r_sym = TO_NATIVE(r_sym); 1636 r_typ = ELF64_MIPS_R_TYPE(rel->r_info); 1637 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1638 } else { 1639 r.r_info = TO_NATIVE(rel->r_info); 1640 r_sym = ELF_R_SYM(r.r_info); 1641 } 1642 #else 1643 r.r_info = TO_NATIVE(rel->r_info); 1644 r_sym = ELF_R_SYM(r.r_info); 1645 #endif 1646 r.r_addend = 0; 1647 switch (elf->hdr->e_machine) { 1648 case EM_386: 1649 if (addend_386_rel(elf, sechdr, &r)) 1650 continue; 1651 break; 1652 case EM_ARM: 1653 if (addend_arm_rel(elf, sechdr, &r)) 1654 continue; 1655 break; 1656 case EM_MIPS: 1657 if (addend_mips_rel(elf, sechdr, &r)) 1658 continue; 1659 break; 1660 } 1661 sym = elf->symtab_start + r_sym; 1662 /* Skip special sections */ 1663 if (is_shndx_special(sym->st_shndx)) 1664 continue; 1665 check_section_mismatch(modname, elf, &r, sym, fromsec); 1666 } 1667 } 1668 1669 /** 1670 * A module includes a number of sections that are discarded 1671 * either when loaded or when used as built-in. 1672 * For loaded modules all functions marked __init and all data 1673 * marked __initdata will be discarded when the module has been initialized. 1674 * Likewise for modules used built-in the sections marked __exit 1675 * are discarded because __exit marked function are supposed to be called 1676 * only when a module is unloaded which never happens for built-in modules. 1677 * The check_sec_ref() function traverses all relocation records 1678 * to find all references to a section that reference a section that will 1679 * be discarded and warns about it. 1680 **/ 1681 static void check_sec_ref(struct module *mod, const char *modname, 1682 struct elf_info *elf) 1683 { 1684 int i; 1685 Elf_Shdr *sechdrs = elf->sechdrs; 1686 1687 /* Walk through all sections */ 1688 for (i = 0; i < elf->num_sections; i++) { 1689 check_section(modname, elf, &elf->sechdrs[i]); 1690 /* We want to process only relocation sections and not .init */ 1691 if (sechdrs[i].sh_type == SHT_RELA) 1692 section_rela(modname, elf, &elf->sechdrs[i]); 1693 else if (sechdrs[i].sh_type == SHT_REL) 1694 section_rel(modname, elf, &elf->sechdrs[i]); 1695 } 1696 } 1697 1698 static void read_symbols(char *modname) 1699 { 1700 const char *symname; 1701 char *version; 1702 char *license; 1703 struct module *mod; 1704 struct elf_info info = { }; 1705 Elf_Sym *sym; 1706 1707 if (!parse_elf(&info, modname)) 1708 return; 1709 1710 mod = new_module(modname); 1711 1712 /* When there's no vmlinux, don't print warnings about 1713 * unresolved symbols (since there'll be too many ;) */ 1714 if (is_vmlinux(modname)) { 1715 have_vmlinux = 1; 1716 mod->skip = 1; 1717 } 1718 1719 license = get_modinfo(info.modinfo, info.modinfo_len, "license"); 1720 if (info.modinfo && !license && !is_vmlinux(modname)) 1721 warn("modpost: missing MODULE_LICENSE() in %s\n" 1722 "see include/linux/module.h for " 1723 "more information\n", modname); 1724 while (license) { 1725 if (license_is_gpl_compatible(license)) 1726 mod->gpl_compatible = 1; 1727 else { 1728 mod->gpl_compatible = 0; 1729 break; 1730 } 1731 license = get_next_modinfo(info.modinfo, info.modinfo_len, 1732 "license", license); 1733 } 1734 1735 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1736 symname = info.strtab + sym->st_name; 1737 1738 handle_modversions(mod, &info, sym, symname); 1739 handle_moddevtable(mod, &info, sym, symname); 1740 } 1741 if (!is_vmlinux(modname) || 1742 (is_vmlinux(modname) && vmlinux_section_warnings)) 1743 check_sec_ref(mod, modname, &info); 1744 1745 version = get_modinfo(info.modinfo, info.modinfo_len, "version"); 1746 if (version) 1747 maybe_frob_rcs_version(modname, version, info.modinfo, 1748 version - (char *)info.hdr); 1749 if (version || (all_versions && !is_vmlinux(modname))) 1750 get_src_version(modname, mod->srcversion, 1751 sizeof(mod->srcversion)-1); 1752 1753 parse_elf_finish(&info); 1754 1755 /* Our trick to get versioning for module struct etc. - it's 1756 * never passed as an argument to an exported function, so 1757 * the automatic versioning doesn't pick it up, but it's really 1758 * important anyhow */ 1759 if (modversions) 1760 mod->unres = alloc_symbol("module_layout", 0, mod->unres); 1761 } 1762 1763 #define SZ 500 1764 1765 /* We first write the generated file into memory using the 1766 * following helper, then compare to the file on disk and 1767 * only update the later if anything changed */ 1768 1769 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1770 const char *fmt, ...) 1771 { 1772 char tmp[SZ]; 1773 int len; 1774 va_list ap; 1775 1776 va_start(ap, fmt); 1777 len = vsnprintf(tmp, SZ, fmt, ap); 1778 buf_write(buf, tmp, len); 1779 va_end(ap); 1780 } 1781 1782 void buf_write(struct buffer *buf, const char *s, int len) 1783 { 1784 if (buf->size - buf->pos < len) { 1785 buf->size += len + SZ; 1786 buf->p = realloc(buf->p, buf->size); 1787 } 1788 strncpy(buf->p + buf->pos, s, len); 1789 buf->pos += len; 1790 } 1791 1792 static void check_for_gpl_usage(enum export exp, const char *m, const char *s) 1793 { 1794 const char *e = is_vmlinux(m) ?"":".ko"; 1795 1796 switch (exp) { 1797 case export_gpl: 1798 fatal("modpost: GPL-incompatible module %s%s " 1799 "uses GPL-only symbol '%s'\n", m, e, s); 1800 break; 1801 case export_unused_gpl: 1802 fatal("modpost: GPL-incompatible module %s%s " 1803 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); 1804 break; 1805 case export_gpl_future: 1806 warn("modpost: GPL-incompatible module %s%s " 1807 "uses future GPL-only symbol '%s'\n", m, e, s); 1808 break; 1809 case export_plain: 1810 case export_unused: 1811 case export_unknown: 1812 /* ignore */ 1813 break; 1814 } 1815 } 1816 1817 static void check_for_unused(enum export exp, const char *m, const char *s) 1818 { 1819 const char *e = is_vmlinux(m) ?"":".ko"; 1820 1821 switch (exp) { 1822 case export_unused: 1823 case export_unused_gpl: 1824 warn("modpost: module %s%s " 1825 "uses symbol '%s' marked UNUSED\n", m, e, s); 1826 break; 1827 default: 1828 /* ignore */ 1829 break; 1830 } 1831 } 1832 1833 static void check_exports(struct module *mod) 1834 { 1835 struct symbol *s, *exp; 1836 1837 for (s = mod->unres; s; s = s->next) { 1838 const char *basename; 1839 exp = find_symbol(s->name); 1840 if (!exp || exp->module == mod) 1841 continue; 1842 basename = strrchr(mod->name, '/'); 1843 if (basename) 1844 basename++; 1845 else 1846 basename = mod->name; 1847 if (!mod->gpl_compatible) 1848 check_for_gpl_usage(exp->export, basename, exp->name); 1849 check_for_unused(exp->export, basename, exp->name); 1850 } 1851 } 1852 1853 /** 1854 * Header for the generated file 1855 **/ 1856 static void add_header(struct buffer *b, struct module *mod) 1857 { 1858 buf_printf(b, "#include <linux/module.h>\n"); 1859 buf_printf(b, "#include <linux/vermagic.h>\n"); 1860 buf_printf(b, "#include <linux/compiler.h>\n"); 1861 buf_printf(b, "\n"); 1862 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1863 buf_printf(b, "\n"); 1864 buf_printf(b, "struct module __this_module\n"); 1865 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); 1866 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1867 if (mod->has_init) 1868 buf_printf(b, "\t.init = init_module,\n"); 1869 if (mod->has_cleanup) 1870 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1871 "\t.exit = cleanup_module,\n" 1872 "#endif\n"); 1873 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1874 buf_printf(b, "};\n"); 1875 } 1876 1877 static void add_intree_flag(struct buffer *b, int is_intree) 1878 { 1879 if (is_intree) 1880 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1881 } 1882 1883 static void add_staging_flag(struct buffer *b, const char *name) 1884 { 1885 static const char *staging_dir = "drivers/staging"; 1886 1887 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0) 1888 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1889 } 1890 1891 /** 1892 * Record CRCs for unresolved symbols 1893 **/ 1894 static int add_versions(struct buffer *b, struct module *mod) 1895 { 1896 struct symbol *s, *exp; 1897 int err = 0; 1898 1899 for (s = mod->unres; s; s = s->next) { 1900 exp = find_symbol(s->name); 1901 if (!exp || exp->module == mod) { 1902 if (have_vmlinux && !s->weak) { 1903 if (warn_unresolved) { 1904 warn("\"%s\" [%s.ko] undefined!\n", 1905 s->name, mod->name); 1906 } else { 1907 merror("\"%s\" [%s.ko] undefined!\n", 1908 s->name, mod->name); 1909 err = 1; 1910 } 1911 } 1912 continue; 1913 } 1914 s->module = exp->module; 1915 s->crc_valid = exp->crc_valid; 1916 s->crc = exp->crc; 1917 } 1918 1919 if (!modversions) 1920 return err; 1921 1922 buf_printf(b, "\n"); 1923 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1924 buf_printf(b, "__used\n"); 1925 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); 1926 1927 for (s = mod->unres; s; s = s->next) { 1928 if (!s->module) 1929 continue; 1930 if (!s->crc_valid) { 1931 warn("\"%s\" [%s.ko] has no CRC!\n", 1932 s->name, mod->name); 1933 continue; 1934 } 1935 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); 1936 } 1937 1938 buf_printf(b, "};\n"); 1939 1940 return err; 1941 } 1942 1943 static void add_depends(struct buffer *b, struct module *mod, 1944 struct module *modules) 1945 { 1946 struct symbol *s; 1947 struct module *m; 1948 int first = 1; 1949 1950 for (m = modules; m; m = m->next) 1951 m->seen = is_vmlinux(m->name); 1952 1953 buf_printf(b, "\n"); 1954 buf_printf(b, "static const char __module_depends[]\n"); 1955 buf_printf(b, "__used\n"); 1956 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); 1957 buf_printf(b, "\"depends="); 1958 for (s = mod->unres; s; s = s->next) { 1959 const char *p; 1960 if (!s->module) 1961 continue; 1962 1963 if (s->module->seen) 1964 continue; 1965 1966 s->module->seen = 1; 1967 p = strrchr(s->module->name, '/'); 1968 if (p) 1969 p++; 1970 else 1971 p = s->module->name; 1972 buf_printf(b, "%s%s", first ? "" : ",", p); 1973 first = 0; 1974 } 1975 buf_printf(b, "\";\n"); 1976 } 1977 1978 static void add_srcversion(struct buffer *b, struct module *mod) 1979 { 1980 if (mod->srcversion[0]) { 1981 buf_printf(b, "\n"); 1982 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1983 mod->srcversion); 1984 } 1985 } 1986 1987 static void write_if_changed(struct buffer *b, const char *fname) 1988 { 1989 char *tmp; 1990 FILE *file; 1991 struct stat st; 1992 1993 file = fopen(fname, "r"); 1994 if (!file) 1995 goto write; 1996 1997 if (fstat(fileno(file), &st) < 0) 1998 goto close_write; 1999 2000 if (st.st_size != b->pos) 2001 goto close_write; 2002 2003 tmp = NOFAIL(malloc(b->pos)); 2004 if (fread(tmp, 1, b->pos, file) != b->pos) 2005 goto free_write; 2006 2007 if (memcmp(tmp, b->p, b->pos) != 0) 2008 goto free_write; 2009 2010 free(tmp); 2011 fclose(file); 2012 return; 2013 2014 free_write: 2015 free(tmp); 2016 close_write: 2017 fclose(file); 2018 write: 2019 file = fopen(fname, "w"); 2020 if (!file) { 2021 perror(fname); 2022 exit(1); 2023 } 2024 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2025 perror(fname); 2026 exit(1); 2027 } 2028 fclose(file); 2029 } 2030 2031 /* parse Module.symvers file. line format: 2032 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] 2033 **/ 2034 static void read_dump(const char *fname, unsigned int kernel) 2035 { 2036 unsigned long size, pos = 0; 2037 void *file = grab_file(fname, &size); 2038 char *line; 2039 2040 if (!file) 2041 /* No symbol versions, silently ignore */ 2042 return; 2043 2044 while ((line = get_next_line(&pos, file, size))) { 2045 char *symname, *modname, *d, *export, *end; 2046 unsigned int crc; 2047 struct module *mod; 2048 struct symbol *s; 2049 2050 if (!(symname = strchr(line, '\t'))) 2051 goto fail; 2052 *symname++ = '\0'; 2053 if (!(modname = strchr(symname, '\t'))) 2054 goto fail; 2055 *modname++ = '\0'; 2056 if ((export = strchr(modname, '\t')) != NULL) 2057 *export++ = '\0'; 2058 if (export && ((end = strchr(export, '\t')) != NULL)) 2059 *end = '\0'; 2060 crc = strtoul(line, &d, 16); 2061 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2062 goto fail; 2063 mod = find_module(modname); 2064 if (!mod) { 2065 if (is_vmlinux(modname)) 2066 have_vmlinux = 1; 2067 mod = new_module(modname); 2068 mod->skip = 1; 2069 } 2070 s = sym_add_exported(symname, mod, export_no(export)); 2071 s->kernel = kernel; 2072 s->preloaded = 1; 2073 sym_update_crc(symname, mod, crc, export_no(export)); 2074 } 2075 return; 2076 fail: 2077 fatal("parse error in symbol dump file\n"); 2078 } 2079 2080 /* For normal builds always dump all symbols. 2081 * For external modules only dump symbols 2082 * that are not read from kernel Module.symvers. 2083 **/ 2084 static int dump_sym(struct symbol *sym) 2085 { 2086 if (!external_module) 2087 return 1; 2088 if (sym->vmlinux || sym->kernel) 2089 return 0; 2090 return 1; 2091 } 2092 2093 static void write_dump(const char *fname) 2094 { 2095 struct buffer buf = { }; 2096 struct symbol *symbol; 2097 int n; 2098 2099 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { 2100 symbol = symbolhash[n]; 2101 while (symbol) { 2102 if (dump_sym(symbol)) 2103 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", 2104 symbol->crc, symbol->name, 2105 symbol->module->name, 2106 export_str(symbol->export)); 2107 symbol = symbol->next; 2108 } 2109 } 2110 write_if_changed(&buf, fname); 2111 } 2112 2113 struct ext_sym_list { 2114 struct ext_sym_list *next; 2115 const char *file; 2116 }; 2117 2118 int main(int argc, char **argv) 2119 { 2120 struct module *mod; 2121 struct buffer buf = { }; 2122 char *kernel_read = NULL, *module_read = NULL; 2123 char *dump_write = NULL; 2124 int opt; 2125 int err; 2126 struct ext_sym_list *extsym_iter; 2127 struct ext_sym_list *extsym_start = NULL; 2128 2129 while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) { 2130 switch (opt) { 2131 case 'i': 2132 kernel_read = optarg; 2133 break; 2134 case 'I': 2135 module_read = optarg; 2136 external_module = 1; 2137 break; 2138 case 'c': 2139 cross_build = 1; 2140 break; 2141 case 'e': 2142 external_module = 1; 2143 extsym_iter = 2144 NOFAIL(malloc(sizeof(*extsym_iter))); 2145 extsym_iter->next = extsym_start; 2146 extsym_iter->file = optarg; 2147 extsym_start = extsym_iter; 2148 break; 2149 case 'm': 2150 modversions = 1; 2151 break; 2152 case 'o': 2153 dump_write = optarg; 2154 break; 2155 case 'a': 2156 all_versions = 1; 2157 break; 2158 case 's': 2159 vmlinux_section_warnings = 0; 2160 break; 2161 case 'S': 2162 sec_mismatch_verbose = 0; 2163 break; 2164 case 'w': 2165 warn_unresolved = 1; 2166 break; 2167 default: 2168 exit(1); 2169 } 2170 } 2171 2172 if (kernel_read) 2173 read_dump(kernel_read, 1); 2174 if (module_read) 2175 read_dump(module_read, 0); 2176 while (extsym_start) { 2177 read_dump(extsym_start->file, 0); 2178 extsym_iter = extsym_start->next; 2179 free(extsym_start); 2180 extsym_start = extsym_iter; 2181 } 2182 2183 while (optind < argc) 2184 read_symbols(argv[optind++]); 2185 2186 for (mod = modules; mod; mod = mod->next) { 2187 if (mod->skip) 2188 continue; 2189 check_exports(mod); 2190 } 2191 2192 err = 0; 2193 2194 for (mod = modules; mod; mod = mod->next) { 2195 char fname[strlen(mod->name) + 10]; 2196 2197 if (mod->skip) 2198 continue; 2199 2200 buf.pos = 0; 2201 2202 add_header(&buf, mod); 2203 add_intree_flag(&buf, !external_module); 2204 add_staging_flag(&buf, mod->name); 2205 err |= add_versions(&buf, mod); 2206 add_depends(&buf, mod, modules); 2207 add_moddevtable(&buf, mod); 2208 add_srcversion(&buf, mod); 2209 2210 sprintf(fname, "%s.mod.c", mod->name); 2211 write_if_changed(&buf, fname); 2212 } 2213 2214 if (dump_write) 2215 write_dump(dump_write); 2216 if (sec_mismatch_count && !sec_mismatch_verbose) 2217 warn("modpost: Found %d section mismatch(es).\n" 2218 "To see full details build your kernel with:\n" 2219 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n", 2220 sec_mismatch_count); 2221 2222 return err; 2223 } 2224