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$" 867 868 #define ALL_PCI_INIT_SECTIONS \ 869 ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \ 870 ".pci_fixup_enable$", ".pci_fixup_resume$", \ 871 ".pci_fixup_resume_early$", ".pci_fixup_suspend$" 872 873 #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \ 874 MEM_INIT_SECTIONS 875 #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \ 876 MEM_EXIT_SECTIONS 877 878 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 879 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS 880 881 #define DATA_SECTIONS ".data$", ".data.rel$" 882 #define TEXT_SECTIONS ".text$" 883 884 #define INIT_SECTIONS ".init.*" 885 #define DEV_INIT_SECTIONS ".devinit.*" 886 #define CPU_INIT_SECTIONS ".cpuinit.*" 887 #define MEM_INIT_SECTIONS ".meminit.*" 888 889 #define EXIT_SECTIONS ".exit.*" 890 #define DEV_EXIT_SECTIONS ".devexit.*" 891 #define CPU_EXIT_SECTIONS ".cpuexit.*" 892 #define MEM_EXIT_SECTIONS ".memexit.*" 893 894 /* init data sections */ 895 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL }; 896 897 /* all init sections */ 898 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL }; 899 900 /* All init and exit sections (code + data) */ 901 static const char *init_exit_sections[] = 902 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }; 903 904 /* data section */ 905 static const char *data_sections[] = { DATA_SECTIONS, NULL }; 906 907 908 /* symbols in .data that may refer to init/exit sections */ 909 #define DEFAULT_SYMBOL_WHITE_LIST \ 910 "*driver", \ 911 "*_template", /* scsi uses *_template a lot */ \ 912 "*_timer", /* arm uses ops structures named _timer a lot */ \ 913 "*_sht", /* scsi also used *_sht to some extent */ \ 914 "*_ops", \ 915 "*_probe", \ 916 "*_probe_one", \ 917 "*_console" 918 919 static const char *head_sections[] = { ".head.text*", NULL }; 920 static const char *linker_symbols[] = 921 { "__init_begin", "_sinittext", "_einittext", NULL }; 922 923 enum mismatch { 924 TEXT_TO_ANY_INIT, 925 DATA_TO_ANY_INIT, 926 TEXT_TO_ANY_EXIT, 927 DATA_TO_ANY_EXIT, 928 XXXINIT_TO_SOME_INIT, 929 XXXEXIT_TO_SOME_EXIT, 930 ANY_INIT_TO_ANY_EXIT, 931 ANY_EXIT_TO_ANY_INIT, 932 EXPORT_TO_INIT_EXIT, 933 }; 934 935 struct sectioncheck { 936 const char *fromsec[20]; 937 const char *tosec[20]; 938 enum mismatch mismatch; 939 const char *symbol_white_list[20]; 940 }; 941 942 const struct sectioncheck sectioncheck[] = { 943 /* Do not reference init/exit code/data from 944 * normal code and data 945 */ 946 { 947 .fromsec = { TEXT_SECTIONS, NULL }, 948 .tosec = { ALL_INIT_SECTIONS, NULL }, 949 .mismatch = TEXT_TO_ANY_INIT, 950 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 951 }, 952 { 953 .fromsec = { DATA_SECTIONS, NULL }, 954 .tosec = { ALL_XXXINIT_SECTIONS, NULL }, 955 .mismatch = DATA_TO_ANY_INIT, 956 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 957 }, 958 { 959 .fromsec = { DATA_SECTIONS, NULL }, 960 .tosec = { INIT_SECTIONS, NULL }, 961 .mismatch = DATA_TO_ANY_INIT, 962 .symbol_white_list = { 963 "*_template", "*_timer", "*_sht", "*_ops", 964 "*_probe", "*_probe_one", "*_console", NULL 965 }, 966 }, 967 { 968 .fromsec = { TEXT_SECTIONS, NULL }, 969 .tosec = { ALL_EXIT_SECTIONS, NULL }, 970 .mismatch = TEXT_TO_ANY_EXIT, 971 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 972 }, 973 { 974 .fromsec = { DATA_SECTIONS, NULL }, 975 .tosec = { ALL_EXIT_SECTIONS, NULL }, 976 .mismatch = DATA_TO_ANY_EXIT, 977 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 978 }, 979 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */ 980 { 981 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 982 .tosec = { INIT_SECTIONS, NULL }, 983 .mismatch = XXXINIT_TO_SOME_INIT, 984 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 985 }, 986 /* Do not reference cpuinit code/data from meminit code/data */ 987 { 988 .fromsec = { MEM_INIT_SECTIONS, NULL }, 989 .tosec = { CPU_INIT_SECTIONS, NULL }, 990 .mismatch = XXXINIT_TO_SOME_INIT, 991 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 992 }, 993 /* Do not reference meminit code/data from cpuinit code/data */ 994 { 995 .fromsec = { CPU_INIT_SECTIONS, NULL }, 996 .tosec = { MEM_INIT_SECTIONS, NULL }, 997 .mismatch = XXXINIT_TO_SOME_INIT, 998 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 999 }, 1000 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */ 1001 { 1002 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL }, 1003 .tosec = { EXIT_SECTIONS, NULL }, 1004 .mismatch = XXXEXIT_TO_SOME_EXIT, 1005 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1006 }, 1007 /* Do not reference cpuexit code/data from memexit code/data */ 1008 { 1009 .fromsec = { MEM_EXIT_SECTIONS, NULL }, 1010 .tosec = { CPU_EXIT_SECTIONS, NULL }, 1011 .mismatch = XXXEXIT_TO_SOME_EXIT, 1012 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1013 }, 1014 /* Do not reference memexit code/data from cpuexit code/data */ 1015 { 1016 .fromsec = { CPU_EXIT_SECTIONS, NULL }, 1017 .tosec = { MEM_EXIT_SECTIONS, NULL }, 1018 .mismatch = XXXEXIT_TO_SOME_EXIT, 1019 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1020 }, 1021 /* Do not use exit code/data from init code */ 1022 { 1023 .fromsec = { ALL_INIT_SECTIONS, NULL }, 1024 .tosec = { ALL_EXIT_SECTIONS, NULL }, 1025 .mismatch = ANY_INIT_TO_ANY_EXIT, 1026 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1027 }, 1028 /* Do not use init code/data from exit code */ 1029 { 1030 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 1031 .tosec = { ALL_INIT_SECTIONS, NULL }, 1032 .mismatch = ANY_EXIT_TO_ANY_INIT, 1033 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1034 }, 1035 { 1036 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 1037 .tosec = { INIT_SECTIONS, NULL }, 1038 .mismatch = ANY_INIT_TO_ANY_EXIT, 1039 .symbol_white_list = { NULL }, 1040 }, 1041 /* Do not export init/exit functions or data */ 1042 { 1043 .fromsec = { "__ksymtab*", NULL }, 1044 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL }, 1045 .mismatch = EXPORT_TO_INIT_EXIT, 1046 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1047 } 1048 }; 1049 1050 static const struct sectioncheck *section_mismatch( 1051 const char *fromsec, const char *tosec) 1052 { 1053 int i; 1054 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck); 1055 const struct sectioncheck *check = §ioncheck[0]; 1056 1057 for (i = 0; i < elems; i++) { 1058 if (match(fromsec, check->fromsec) && 1059 match(tosec, check->tosec)) 1060 return check; 1061 check++; 1062 } 1063 return NULL; 1064 } 1065 1066 /** 1067 * Whitelist to allow certain references to pass with no warning. 1068 * 1069 * Pattern 1: 1070 * If a module parameter is declared __initdata and permissions=0 1071 * then this is legal despite the warning generated. 1072 * We cannot see value of permissions here, so just ignore 1073 * this pattern. 1074 * The pattern is identified by: 1075 * tosec = .init.data 1076 * fromsec = .data* 1077 * atsym =__param* 1078 * 1079 * Pattern 1a: 1080 * module_param_call() ops can refer to __init set function if permissions=0 1081 * The pattern is identified by: 1082 * tosec = .init.text 1083 * fromsec = .data* 1084 * atsym = __param_ops_* 1085 * 1086 * Pattern 2: 1087 * Many drivers utilise a *driver container with references to 1088 * add, remove, probe functions etc. 1089 * These functions may often be marked __devinit and we do not want to 1090 * warn here. 1091 * the pattern is identified by: 1092 * tosec = init or exit section 1093 * fromsec = data section 1094 * atsym = *driver, *_template, *_sht, *_ops, *_probe, 1095 * *probe_one, *_console, *_timer 1096 * 1097 * Pattern 3: 1098 * Whitelist all references from .head.text to any init section 1099 * 1100 * Pattern 4: 1101 * Some symbols belong to init section but still it is ok to reference 1102 * these from non-init sections as these symbols don't have any memory 1103 * allocated for them and symbol address and value are same. So even 1104 * if init section is freed, its ok to reference those symbols. 1105 * For ex. symbols marking the init section boundaries. 1106 * This pattern is identified by 1107 * refsymname = __init_begin, _sinittext, _einittext 1108 * 1109 **/ 1110 static int secref_whitelist(const struct sectioncheck *mismatch, 1111 const char *fromsec, const char *fromsym, 1112 const char *tosec, const char *tosym) 1113 { 1114 /* Check for pattern 1 */ 1115 if (match(tosec, init_data_sections) && 1116 match(fromsec, data_sections) && 1117 (strncmp(fromsym, "__param", strlen("__param")) == 0)) 1118 return 0; 1119 1120 /* Check for pattern 1a */ 1121 if (strcmp(tosec, ".init.text") == 0 && 1122 match(fromsec, data_sections) && 1123 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0)) 1124 return 0; 1125 1126 /* Check for pattern 2 */ 1127 if (match(tosec, init_exit_sections) && 1128 match(fromsec, data_sections) && 1129 match(fromsym, mismatch->symbol_white_list)) 1130 return 0; 1131 1132 /* Check for pattern 3 */ 1133 if (match(fromsec, head_sections) && 1134 match(tosec, init_sections)) 1135 return 0; 1136 1137 /* Check for pattern 4 */ 1138 if (match(tosym, linker_symbols)) 1139 return 0; 1140 1141 return 1; 1142 } 1143 1144 /** 1145 * Find symbol based on relocation record info. 1146 * In some cases the symbol supplied is a valid symbol so 1147 * return refsym. If st_name != 0 we assume this is a valid symbol. 1148 * In other cases the symbol needs to be looked up in the symbol table 1149 * based on section and address. 1150 * **/ 1151 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr, 1152 Elf_Sym *relsym) 1153 { 1154 Elf_Sym *sym; 1155 Elf_Sym *near = NULL; 1156 Elf64_Sword distance = 20; 1157 Elf64_Sword d; 1158 unsigned int relsym_secindex; 1159 1160 if (relsym->st_name != 0) 1161 return relsym; 1162 1163 relsym_secindex = get_secindex(elf, relsym); 1164 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1165 if (get_secindex(elf, sym) != relsym_secindex) 1166 continue; 1167 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) 1168 continue; 1169 if (sym->st_value == addr) 1170 return sym; 1171 /* Find a symbol nearby - addr are maybe negative */ 1172 d = sym->st_value - addr; 1173 if (d < 0) 1174 d = addr - sym->st_value; 1175 if (d < distance) { 1176 distance = d; 1177 near = sym; 1178 } 1179 } 1180 /* We need a close match */ 1181 if (distance < 20) 1182 return near; 1183 else 1184 return NULL; 1185 } 1186 1187 static inline int is_arm_mapping_symbol(const char *str) 1188 { 1189 return str[0] == '$' && strchr("atd", str[1]) 1190 && (str[2] == '\0' || str[2] == '.'); 1191 } 1192 1193 /* 1194 * If there's no name there, ignore it; likewise, ignore it if it's 1195 * one of the magic symbols emitted used by current ARM tools. 1196 * 1197 * Otherwise if find_symbols_between() returns those symbols, they'll 1198 * fail the whitelist tests and cause lots of false alarms ... fixable 1199 * only by merging __exit and __init sections into __text, bloating 1200 * the kernel (which is especially evil on embedded platforms). 1201 */ 1202 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 1203 { 1204 const char *name = elf->strtab + sym->st_name; 1205 1206 if (!name || !strlen(name)) 1207 return 0; 1208 return !is_arm_mapping_symbol(name); 1209 } 1210 1211 /* 1212 * Find symbols before or equal addr and after addr - in the section sec. 1213 * If we find two symbols with equal offset prefer one with a valid name. 1214 * The ELF format may have a better way to detect what type of symbol 1215 * it is, but this works for now. 1216 **/ 1217 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr, 1218 const char *sec) 1219 { 1220 Elf_Sym *sym; 1221 Elf_Sym *near = NULL; 1222 Elf_Addr distance = ~0; 1223 1224 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1225 const char *symsec; 1226 1227 if (is_shndx_special(sym->st_shndx)) 1228 continue; 1229 symsec = sec_name(elf, get_secindex(elf, sym)); 1230 if (strcmp(symsec, sec) != 0) 1231 continue; 1232 if (!is_valid_name(elf, sym)) 1233 continue; 1234 if (sym->st_value <= addr) { 1235 if ((addr - sym->st_value) < distance) { 1236 distance = addr - sym->st_value; 1237 near = sym; 1238 } else if ((addr - sym->st_value) == distance) { 1239 near = sym; 1240 } 1241 } 1242 } 1243 return near; 1244 } 1245 1246 /* 1247 * Convert a section name to the function/data attribute 1248 * .init.text => __init 1249 * .cpuinit.data => __cpudata 1250 * .memexitconst => __memconst 1251 * etc. 1252 * 1253 * The memory of returned value has been allocated on a heap. The user of this 1254 * method should free it after usage. 1255 */ 1256 static char *sec2annotation(const char *s) 1257 { 1258 if (match(s, init_exit_sections)) { 1259 char *p = malloc(20); 1260 char *r = p; 1261 1262 *p++ = '_'; 1263 *p++ = '_'; 1264 if (*s == '.') 1265 s++; 1266 while (*s && *s != '.') 1267 *p++ = *s++; 1268 *p = '\0'; 1269 if (*s == '.') 1270 s++; 1271 if (strstr(s, "rodata") != NULL) 1272 strcat(p, "const "); 1273 else if (strstr(s, "data") != NULL) 1274 strcat(p, "data "); 1275 else 1276 strcat(p, " "); 1277 return r; 1278 } else { 1279 return strdup(""); 1280 } 1281 } 1282 1283 static int is_function(Elf_Sym *sym) 1284 { 1285 if (sym) 1286 return ELF_ST_TYPE(sym->st_info) == STT_FUNC; 1287 else 1288 return -1; 1289 } 1290 1291 static void print_section_list(const char * const list[20]) 1292 { 1293 const char *const *s = list; 1294 1295 while (*s) { 1296 fprintf(stderr, "%s", *s); 1297 s++; 1298 if (*s) 1299 fprintf(stderr, ", "); 1300 } 1301 fprintf(stderr, "\n"); 1302 } 1303 1304 /* 1305 * Print a warning about a section mismatch. 1306 * Try to find symbols near it so user can find it. 1307 * Check whitelist before warning - it may be a false positive. 1308 */ 1309 static void report_sec_mismatch(const char *modname, 1310 const struct sectioncheck *mismatch, 1311 const char *fromsec, 1312 unsigned long long fromaddr, 1313 const char *fromsym, 1314 int from_is_func, 1315 const char *tosec, const char *tosym, 1316 int to_is_func) 1317 { 1318 const char *from, *from_p; 1319 const char *to, *to_p; 1320 char *prl_from; 1321 char *prl_to; 1322 1323 switch (from_is_func) { 1324 case 0: from = "variable"; from_p = ""; break; 1325 case 1: from = "function"; from_p = "()"; break; 1326 default: from = "(unknown reference)"; from_p = ""; break; 1327 } 1328 switch (to_is_func) { 1329 case 0: to = "variable"; to_p = ""; break; 1330 case 1: to = "function"; to_p = "()"; break; 1331 default: to = "(unknown reference)"; to_p = ""; break; 1332 } 1333 1334 sec_mismatch_count++; 1335 if (!sec_mismatch_verbose) 1336 return; 1337 1338 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s " 1339 "to the %s %s:%s%s\n", 1340 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec, 1341 tosym, to_p); 1342 1343 switch (mismatch->mismatch) { 1344 case TEXT_TO_ANY_INIT: 1345 prl_from = sec2annotation(fromsec); 1346 prl_to = sec2annotation(tosec); 1347 fprintf(stderr, 1348 "The function %s%s() references\n" 1349 "the %s %s%s%s.\n" 1350 "This is often because %s lacks a %s\n" 1351 "annotation or the annotation of %s is wrong.\n", 1352 prl_from, fromsym, 1353 to, prl_to, tosym, to_p, 1354 fromsym, prl_to, tosym); 1355 free(prl_from); 1356 free(prl_to); 1357 break; 1358 case DATA_TO_ANY_INIT: { 1359 prl_to = sec2annotation(tosec); 1360 fprintf(stderr, 1361 "The variable %s references\n" 1362 "the %s %s%s%s\n" 1363 "If the reference is valid then annotate the\n" 1364 "variable with __init* or __refdata (see linux/init.h) " 1365 "or name the variable:\n", 1366 fromsym, to, prl_to, tosym, to_p); 1367 print_section_list(mismatch->symbol_white_list); 1368 free(prl_to); 1369 break; 1370 } 1371 case TEXT_TO_ANY_EXIT: 1372 prl_to = sec2annotation(tosec); 1373 fprintf(stderr, 1374 "The function %s() references a %s in an exit section.\n" 1375 "Often the %s %s%s has valid usage outside the exit section\n" 1376 "and the fix is to remove the %sannotation of %s.\n", 1377 fromsym, to, to, tosym, to_p, prl_to, tosym); 1378 free(prl_to); 1379 break; 1380 case DATA_TO_ANY_EXIT: { 1381 prl_to = sec2annotation(tosec); 1382 fprintf(stderr, 1383 "The variable %s references\n" 1384 "the %s %s%s%s\n" 1385 "If the reference is valid then annotate the\n" 1386 "variable with __exit* (see linux/init.h) or " 1387 "name the variable:\n", 1388 fromsym, to, prl_to, tosym, to_p); 1389 print_section_list(mismatch->symbol_white_list); 1390 free(prl_to); 1391 break; 1392 } 1393 case XXXINIT_TO_SOME_INIT: 1394 case XXXEXIT_TO_SOME_EXIT: 1395 prl_from = sec2annotation(fromsec); 1396 prl_to = sec2annotation(tosec); 1397 fprintf(stderr, 1398 "The %s %s%s%s references\n" 1399 "a %s %s%s%s.\n" 1400 "If %s is only used by %s then\n" 1401 "annotate %s with a matching annotation.\n", 1402 from, prl_from, fromsym, from_p, 1403 to, prl_to, tosym, to_p, 1404 tosym, fromsym, tosym); 1405 free(prl_from); 1406 free(prl_to); 1407 break; 1408 case ANY_INIT_TO_ANY_EXIT: 1409 prl_from = sec2annotation(fromsec); 1410 prl_to = sec2annotation(tosec); 1411 fprintf(stderr, 1412 "The %s %s%s%s references\n" 1413 "a %s %s%s%s.\n" 1414 "This is often seen when error handling " 1415 "in the init function\n" 1416 "uses functionality in the exit path.\n" 1417 "The fix is often to remove the %sannotation of\n" 1418 "%s%s so it may be used outside an exit section.\n", 1419 from, prl_from, fromsym, from_p, 1420 to, prl_to, tosym, to_p, 1421 prl_to, tosym, to_p); 1422 free(prl_from); 1423 free(prl_to); 1424 break; 1425 case ANY_EXIT_TO_ANY_INIT: 1426 prl_from = sec2annotation(fromsec); 1427 prl_to = sec2annotation(tosec); 1428 fprintf(stderr, 1429 "The %s %s%s%s references\n" 1430 "a %s %s%s%s.\n" 1431 "This is often seen when error handling " 1432 "in the exit function\n" 1433 "uses functionality in the init path.\n" 1434 "The fix is often to remove the %sannotation of\n" 1435 "%s%s so it may be used outside an init section.\n", 1436 from, prl_from, fromsym, from_p, 1437 to, prl_to, tosym, to_p, 1438 prl_to, tosym, to_p); 1439 free(prl_from); 1440 free(prl_to); 1441 break; 1442 case EXPORT_TO_INIT_EXIT: 1443 prl_to = sec2annotation(tosec); 1444 fprintf(stderr, 1445 "The symbol %s is exported and annotated %s\n" 1446 "Fix this by removing the %sannotation of %s " 1447 "or drop the export.\n", 1448 tosym, prl_to, prl_to, tosym); 1449 free(prl_to); 1450 break; 1451 } 1452 fprintf(stderr, "\n"); 1453 } 1454 1455 static void check_section_mismatch(const char *modname, struct elf_info *elf, 1456 Elf_Rela *r, Elf_Sym *sym, const char *fromsec) 1457 { 1458 const char *tosec; 1459 const struct sectioncheck *mismatch; 1460 1461 tosec = sec_name(elf, get_secindex(elf, sym)); 1462 mismatch = section_mismatch(fromsec, tosec); 1463 if (mismatch) { 1464 Elf_Sym *to; 1465 Elf_Sym *from; 1466 const char *tosym; 1467 const char *fromsym; 1468 1469 from = find_elf_symbol2(elf, r->r_offset, fromsec); 1470 fromsym = sym_name(elf, from); 1471 to = find_elf_symbol(elf, r->r_addend, sym); 1472 tosym = sym_name(elf, to); 1473 1474 /* check whitelist - we may ignore it */ 1475 if (secref_whitelist(mismatch, 1476 fromsec, fromsym, tosec, tosym)) { 1477 report_sec_mismatch(modname, mismatch, 1478 fromsec, r->r_offset, fromsym, 1479 is_function(from), tosec, tosym, 1480 is_function(to)); 1481 } 1482 } 1483 } 1484 1485 static unsigned int *reloc_location(struct elf_info *elf, 1486 Elf_Shdr *sechdr, Elf_Rela *r) 1487 { 1488 Elf_Shdr *sechdrs = elf->sechdrs; 1489 int section = sechdr->sh_info; 1490 1491 return (void *)elf->hdr + sechdrs[section].sh_offset + 1492 r->r_offset; 1493 } 1494 1495 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1496 { 1497 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1498 unsigned int *location = reloc_location(elf, sechdr, r); 1499 1500 switch (r_typ) { 1501 case R_386_32: 1502 r->r_addend = TO_NATIVE(*location); 1503 break; 1504 case R_386_PC32: 1505 r->r_addend = TO_NATIVE(*location) + 4; 1506 /* For CONFIG_RELOCATABLE=y */ 1507 if (elf->hdr->e_type == ET_EXEC) 1508 r->r_addend += r->r_offset; 1509 break; 1510 } 1511 return 0; 1512 } 1513 1514 #ifndef R_ARM_CALL 1515 #define R_ARM_CALL 28 1516 #endif 1517 #ifndef R_ARM_JUMP24 1518 #define R_ARM_JUMP24 29 1519 #endif 1520 1521 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1522 { 1523 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1524 1525 switch (r_typ) { 1526 case R_ARM_ABS32: 1527 /* From ARM ABI: (S + A) | T */ 1528 r->r_addend = (int)(long) 1529 (elf->symtab_start + ELF_R_SYM(r->r_info)); 1530 break; 1531 case R_ARM_PC24: 1532 case R_ARM_CALL: 1533 case R_ARM_JUMP24: 1534 /* From ARM ABI: ((S + A) | T) - P */ 1535 r->r_addend = (int)(long)(elf->hdr + 1536 sechdr->sh_offset + 1537 (r->r_offset - sechdr->sh_addr)); 1538 break; 1539 default: 1540 return 1; 1541 } 1542 return 0; 1543 } 1544 1545 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1546 { 1547 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1548 unsigned int *location = reloc_location(elf, sechdr, r); 1549 unsigned int inst; 1550 1551 if (r_typ == R_MIPS_HI16) 1552 return 1; /* skip this */ 1553 inst = TO_NATIVE(*location); 1554 switch (r_typ) { 1555 case R_MIPS_LO16: 1556 r->r_addend = inst & 0xffff; 1557 break; 1558 case R_MIPS_26: 1559 r->r_addend = (inst & 0x03ffffff) << 2; 1560 break; 1561 case R_MIPS_32: 1562 r->r_addend = inst; 1563 break; 1564 } 1565 return 0; 1566 } 1567 1568 static void section_rela(const char *modname, struct elf_info *elf, 1569 Elf_Shdr *sechdr) 1570 { 1571 Elf_Sym *sym; 1572 Elf_Rela *rela; 1573 Elf_Rela r; 1574 unsigned int r_sym; 1575 const char *fromsec; 1576 1577 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; 1578 Elf_Rela *stop = (void *)start + sechdr->sh_size; 1579 1580 fromsec = sech_name(elf, sechdr); 1581 fromsec += strlen(".rela"); 1582 /* if from section (name) is know good then skip it */ 1583 if (match(fromsec, section_white_list)) 1584 return; 1585 1586 for (rela = start; rela < stop; rela++) { 1587 r.r_offset = TO_NATIVE(rela->r_offset); 1588 #if KERNEL_ELFCLASS == ELFCLASS64 1589 if (elf->hdr->e_machine == EM_MIPS) { 1590 unsigned int r_typ; 1591 r_sym = ELF64_MIPS_R_SYM(rela->r_info); 1592 r_sym = TO_NATIVE(r_sym); 1593 r_typ = ELF64_MIPS_R_TYPE(rela->r_info); 1594 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1595 } else { 1596 r.r_info = TO_NATIVE(rela->r_info); 1597 r_sym = ELF_R_SYM(r.r_info); 1598 } 1599 #else 1600 r.r_info = TO_NATIVE(rela->r_info); 1601 r_sym = ELF_R_SYM(r.r_info); 1602 #endif 1603 r.r_addend = TO_NATIVE(rela->r_addend); 1604 sym = elf->symtab_start + r_sym; 1605 /* Skip special sections */ 1606 if (is_shndx_special(sym->st_shndx)) 1607 continue; 1608 check_section_mismatch(modname, elf, &r, sym, fromsec); 1609 } 1610 } 1611 1612 static void section_rel(const char *modname, struct elf_info *elf, 1613 Elf_Shdr *sechdr) 1614 { 1615 Elf_Sym *sym; 1616 Elf_Rel *rel; 1617 Elf_Rela r; 1618 unsigned int r_sym; 1619 const char *fromsec; 1620 1621 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset; 1622 Elf_Rel *stop = (void *)start + sechdr->sh_size; 1623 1624 fromsec = sech_name(elf, sechdr); 1625 fromsec += strlen(".rel"); 1626 /* if from section (name) is know good then skip it */ 1627 if (match(fromsec, section_white_list)) 1628 return; 1629 1630 for (rel = start; rel < stop; rel++) { 1631 r.r_offset = TO_NATIVE(rel->r_offset); 1632 #if KERNEL_ELFCLASS == ELFCLASS64 1633 if (elf->hdr->e_machine == EM_MIPS) { 1634 unsigned int r_typ; 1635 r_sym = ELF64_MIPS_R_SYM(rel->r_info); 1636 r_sym = TO_NATIVE(r_sym); 1637 r_typ = ELF64_MIPS_R_TYPE(rel->r_info); 1638 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1639 } else { 1640 r.r_info = TO_NATIVE(rel->r_info); 1641 r_sym = ELF_R_SYM(r.r_info); 1642 } 1643 #else 1644 r.r_info = TO_NATIVE(rel->r_info); 1645 r_sym = ELF_R_SYM(r.r_info); 1646 #endif 1647 r.r_addend = 0; 1648 switch (elf->hdr->e_machine) { 1649 case EM_386: 1650 if (addend_386_rel(elf, sechdr, &r)) 1651 continue; 1652 break; 1653 case EM_ARM: 1654 if (addend_arm_rel(elf, sechdr, &r)) 1655 continue; 1656 break; 1657 case EM_MIPS: 1658 if (addend_mips_rel(elf, sechdr, &r)) 1659 continue; 1660 break; 1661 } 1662 sym = elf->symtab_start + r_sym; 1663 /* Skip special sections */ 1664 if (is_shndx_special(sym->st_shndx)) 1665 continue; 1666 check_section_mismatch(modname, elf, &r, sym, fromsec); 1667 } 1668 } 1669 1670 /** 1671 * A module includes a number of sections that are discarded 1672 * either when loaded or when used as built-in. 1673 * For loaded modules all functions marked __init and all data 1674 * marked __initdata will be discarded when the module has been initialized. 1675 * Likewise for modules used built-in the sections marked __exit 1676 * are discarded because __exit marked function are supposed to be called 1677 * only when a module is unloaded which never happens for built-in modules. 1678 * The check_sec_ref() function traverses all relocation records 1679 * to find all references to a section that reference a section that will 1680 * be discarded and warns about it. 1681 **/ 1682 static void check_sec_ref(struct module *mod, const char *modname, 1683 struct elf_info *elf) 1684 { 1685 int i; 1686 Elf_Shdr *sechdrs = elf->sechdrs; 1687 1688 /* Walk through all sections */ 1689 for (i = 0; i < elf->num_sections; i++) { 1690 check_section(modname, elf, &elf->sechdrs[i]); 1691 /* We want to process only relocation sections and not .init */ 1692 if (sechdrs[i].sh_type == SHT_RELA) 1693 section_rela(modname, elf, &elf->sechdrs[i]); 1694 else if (sechdrs[i].sh_type == SHT_REL) 1695 section_rel(modname, elf, &elf->sechdrs[i]); 1696 } 1697 } 1698 1699 static void read_symbols(char *modname) 1700 { 1701 const char *symname; 1702 char *version; 1703 char *license; 1704 struct module *mod; 1705 struct elf_info info = { }; 1706 Elf_Sym *sym; 1707 1708 if (!parse_elf(&info, modname)) 1709 return; 1710 1711 mod = new_module(modname); 1712 1713 /* When there's no vmlinux, don't print warnings about 1714 * unresolved symbols (since there'll be too many ;) */ 1715 if (is_vmlinux(modname)) { 1716 have_vmlinux = 1; 1717 mod->skip = 1; 1718 } 1719 1720 license = get_modinfo(info.modinfo, info.modinfo_len, "license"); 1721 if (info.modinfo && !license && !is_vmlinux(modname)) 1722 warn("modpost: missing MODULE_LICENSE() in %s\n" 1723 "see include/linux/module.h for " 1724 "more information\n", modname); 1725 while (license) { 1726 if (license_is_gpl_compatible(license)) 1727 mod->gpl_compatible = 1; 1728 else { 1729 mod->gpl_compatible = 0; 1730 break; 1731 } 1732 license = get_next_modinfo(info.modinfo, info.modinfo_len, 1733 "license", license); 1734 } 1735 1736 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1737 symname = info.strtab + sym->st_name; 1738 1739 handle_modversions(mod, &info, sym, symname); 1740 handle_moddevtable(mod, &info, sym, symname); 1741 } 1742 if (!is_vmlinux(modname) || 1743 (is_vmlinux(modname) && vmlinux_section_warnings)) 1744 check_sec_ref(mod, modname, &info); 1745 1746 version = get_modinfo(info.modinfo, info.modinfo_len, "version"); 1747 if (version) 1748 maybe_frob_rcs_version(modname, version, info.modinfo, 1749 version - (char *)info.hdr); 1750 if (version || (all_versions && !is_vmlinux(modname))) 1751 get_src_version(modname, mod->srcversion, 1752 sizeof(mod->srcversion)-1); 1753 1754 parse_elf_finish(&info); 1755 1756 /* Our trick to get versioning for module struct etc. - it's 1757 * never passed as an argument to an exported function, so 1758 * the automatic versioning doesn't pick it up, but it's really 1759 * important anyhow */ 1760 if (modversions) 1761 mod->unres = alloc_symbol("module_layout", 0, mod->unres); 1762 } 1763 1764 #define SZ 500 1765 1766 /* We first write the generated file into memory using the 1767 * following helper, then compare to the file on disk and 1768 * only update the later if anything changed */ 1769 1770 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1771 const char *fmt, ...) 1772 { 1773 char tmp[SZ]; 1774 int len; 1775 va_list ap; 1776 1777 va_start(ap, fmt); 1778 len = vsnprintf(tmp, SZ, fmt, ap); 1779 buf_write(buf, tmp, len); 1780 va_end(ap); 1781 } 1782 1783 void buf_write(struct buffer *buf, const char *s, int len) 1784 { 1785 if (buf->size - buf->pos < len) { 1786 buf->size += len + SZ; 1787 buf->p = realloc(buf->p, buf->size); 1788 } 1789 strncpy(buf->p + buf->pos, s, len); 1790 buf->pos += len; 1791 } 1792 1793 static void check_for_gpl_usage(enum export exp, const char *m, const char *s) 1794 { 1795 const char *e = is_vmlinux(m) ?"":".ko"; 1796 1797 switch (exp) { 1798 case export_gpl: 1799 fatal("modpost: GPL-incompatible module %s%s " 1800 "uses GPL-only symbol '%s'\n", m, e, s); 1801 break; 1802 case export_unused_gpl: 1803 fatal("modpost: GPL-incompatible module %s%s " 1804 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); 1805 break; 1806 case export_gpl_future: 1807 warn("modpost: GPL-incompatible module %s%s " 1808 "uses future GPL-only symbol '%s'\n", m, e, s); 1809 break; 1810 case export_plain: 1811 case export_unused: 1812 case export_unknown: 1813 /* ignore */ 1814 break; 1815 } 1816 } 1817 1818 static void check_for_unused(enum export exp, const char *m, const char *s) 1819 { 1820 const char *e = is_vmlinux(m) ?"":".ko"; 1821 1822 switch (exp) { 1823 case export_unused: 1824 case export_unused_gpl: 1825 warn("modpost: module %s%s " 1826 "uses symbol '%s' marked UNUSED\n", m, e, s); 1827 break; 1828 default: 1829 /* ignore */ 1830 break; 1831 } 1832 } 1833 1834 static void check_exports(struct module *mod) 1835 { 1836 struct symbol *s, *exp; 1837 1838 for (s = mod->unres; s; s = s->next) { 1839 const char *basename; 1840 exp = find_symbol(s->name); 1841 if (!exp || exp->module == mod) 1842 continue; 1843 basename = strrchr(mod->name, '/'); 1844 if (basename) 1845 basename++; 1846 else 1847 basename = mod->name; 1848 if (!mod->gpl_compatible) 1849 check_for_gpl_usage(exp->export, basename, exp->name); 1850 check_for_unused(exp->export, basename, exp->name); 1851 } 1852 } 1853 1854 /** 1855 * Header for the generated file 1856 **/ 1857 static void add_header(struct buffer *b, struct module *mod) 1858 { 1859 buf_printf(b, "#include <linux/module.h>\n"); 1860 buf_printf(b, "#include <linux/vermagic.h>\n"); 1861 buf_printf(b, "#include <linux/compiler.h>\n"); 1862 buf_printf(b, "\n"); 1863 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1864 buf_printf(b, "\n"); 1865 buf_printf(b, "struct module __this_module\n"); 1866 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); 1867 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1868 if (mod->has_init) 1869 buf_printf(b, "\t.init = init_module,\n"); 1870 if (mod->has_cleanup) 1871 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1872 "\t.exit = cleanup_module,\n" 1873 "#endif\n"); 1874 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1875 buf_printf(b, "};\n"); 1876 } 1877 1878 static void add_intree_flag(struct buffer *b, int is_intree) 1879 { 1880 if (is_intree) 1881 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1882 } 1883 1884 static void add_staging_flag(struct buffer *b, const char *name) 1885 { 1886 static const char *staging_dir = "drivers/staging"; 1887 1888 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0) 1889 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1890 } 1891 1892 /** 1893 * Record CRCs for unresolved symbols 1894 **/ 1895 static int add_versions(struct buffer *b, struct module *mod) 1896 { 1897 struct symbol *s, *exp; 1898 int err = 0; 1899 1900 for (s = mod->unres; s; s = s->next) { 1901 exp = find_symbol(s->name); 1902 if (!exp || exp->module == mod) { 1903 if (have_vmlinux && !s->weak) { 1904 if (warn_unresolved) { 1905 warn("\"%s\" [%s.ko] undefined!\n", 1906 s->name, mod->name); 1907 } else { 1908 merror("\"%s\" [%s.ko] undefined!\n", 1909 s->name, mod->name); 1910 err = 1; 1911 } 1912 } 1913 continue; 1914 } 1915 s->module = exp->module; 1916 s->crc_valid = exp->crc_valid; 1917 s->crc = exp->crc; 1918 } 1919 1920 if (!modversions) 1921 return err; 1922 1923 buf_printf(b, "\n"); 1924 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1925 buf_printf(b, "__used\n"); 1926 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); 1927 1928 for (s = mod->unres; s; s = s->next) { 1929 if (!s->module) 1930 continue; 1931 if (!s->crc_valid) { 1932 warn("\"%s\" [%s.ko] has no CRC!\n", 1933 s->name, mod->name); 1934 continue; 1935 } 1936 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); 1937 } 1938 1939 buf_printf(b, "};\n"); 1940 1941 return err; 1942 } 1943 1944 static void add_depends(struct buffer *b, struct module *mod, 1945 struct module *modules) 1946 { 1947 struct symbol *s; 1948 struct module *m; 1949 int first = 1; 1950 1951 for (m = modules; m; m = m->next) 1952 m->seen = is_vmlinux(m->name); 1953 1954 buf_printf(b, "\n"); 1955 buf_printf(b, "static const char __module_depends[]\n"); 1956 buf_printf(b, "__used\n"); 1957 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); 1958 buf_printf(b, "\"depends="); 1959 for (s = mod->unres; s; s = s->next) { 1960 const char *p; 1961 if (!s->module) 1962 continue; 1963 1964 if (s->module->seen) 1965 continue; 1966 1967 s->module->seen = 1; 1968 p = strrchr(s->module->name, '/'); 1969 if (p) 1970 p++; 1971 else 1972 p = s->module->name; 1973 buf_printf(b, "%s%s", first ? "" : ",", p); 1974 first = 0; 1975 } 1976 buf_printf(b, "\";\n"); 1977 } 1978 1979 static void add_srcversion(struct buffer *b, struct module *mod) 1980 { 1981 if (mod->srcversion[0]) { 1982 buf_printf(b, "\n"); 1983 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1984 mod->srcversion); 1985 } 1986 } 1987 1988 static void write_if_changed(struct buffer *b, const char *fname) 1989 { 1990 char *tmp; 1991 FILE *file; 1992 struct stat st; 1993 1994 file = fopen(fname, "r"); 1995 if (!file) 1996 goto write; 1997 1998 if (fstat(fileno(file), &st) < 0) 1999 goto close_write; 2000 2001 if (st.st_size != b->pos) 2002 goto close_write; 2003 2004 tmp = NOFAIL(malloc(b->pos)); 2005 if (fread(tmp, 1, b->pos, file) != b->pos) 2006 goto free_write; 2007 2008 if (memcmp(tmp, b->p, b->pos) != 0) 2009 goto free_write; 2010 2011 free(tmp); 2012 fclose(file); 2013 return; 2014 2015 free_write: 2016 free(tmp); 2017 close_write: 2018 fclose(file); 2019 write: 2020 file = fopen(fname, "w"); 2021 if (!file) { 2022 perror(fname); 2023 exit(1); 2024 } 2025 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2026 perror(fname); 2027 exit(1); 2028 } 2029 fclose(file); 2030 } 2031 2032 /* parse Module.symvers file. line format: 2033 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] 2034 **/ 2035 static void read_dump(const char *fname, unsigned int kernel) 2036 { 2037 unsigned long size, pos = 0; 2038 void *file = grab_file(fname, &size); 2039 char *line; 2040 2041 if (!file) 2042 /* No symbol versions, silently ignore */ 2043 return; 2044 2045 while ((line = get_next_line(&pos, file, size))) { 2046 char *symname, *modname, *d, *export, *end; 2047 unsigned int crc; 2048 struct module *mod; 2049 struct symbol *s; 2050 2051 if (!(symname = strchr(line, '\t'))) 2052 goto fail; 2053 *symname++ = '\0'; 2054 if (!(modname = strchr(symname, '\t'))) 2055 goto fail; 2056 *modname++ = '\0'; 2057 if ((export = strchr(modname, '\t')) != NULL) 2058 *export++ = '\0'; 2059 if (export && ((end = strchr(export, '\t')) != NULL)) 2060 *end = '\0'; 2061 crc = strtoul(line, &d, 16); 2062 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2063 goto fail; 2064 mod = find_module(modname); 2065 if (!mod) { 2066 if (is_vmlinux(modname)) 2067 have_vmlinux = 1; 2068 mod = new_module(modname); 2069 mod->skip = 1; 2070 } 2071 s = sym_add_exported(symname, mod, export_no(export)); 2072 s->kernel = kernel; 2073 s->preloaded = 1; 2074 sym_update_crc(symname, mod, crc, export_no(export)); 2075 } 2076 return; 2077 fail: 2078 fatal("parse error in symbol dump file\n"); 2079 } 2080 2081 /* For normal builds always dump all symbols. 2082 * For external modules only dump symbols 2083 * that are not read from kernel Module.symvers. 2084 **/ 2085 static int dump_sym(struct symbol *sym) 2086 { 2087 if (!external_module) 2088 return 1; 2089 if (sym->vmlinux || sym->kernel) 2090 return 0; 2091 return 1; 2092 } 2093 2094 static void write_dump(const char *fname) 2095 { 2096 struct buffer buf = { }; 2097 struct symbol *symbol; 2098 int n; 2099 2100 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { 2101 symbol = symbolhash[n]; 2102 while (symbol) { 2103 if (dump_sym(symbol)) 2104 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", 2105 symbol->crc, symbol->name, 2106 symbol->module->name, 2107 export_str(symbol->export)); 2108 symbol = symbol->next; 2109 } 2110 } 2111 write_if_changed(&buf, fname); 2112 } 2113 2114 struct ext_sym_list { 2115 struct ext_sym_list *next; 2116 const char *file; 2117 }; 2118 2119 int main(int argc, char **argv) 2120 { 2121 struct module *mod; 2122 struct buffer buf = { }; 2123 char *kernel_read = NULL, *module_read = NULL; 2124 char *dump_write = NULL; 2125 int opt; 2126 int err; 2127 struct ext_sym_list *extsym_iter; 2128 struct ext_sym_list *extsym_start = NULL; 2129 2130 while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) { 2131 switch (opt) { 2132 case 'i': 2133 kernel_read = optarg; 2134 break; 2135 case 'I': 2136 module_read = optarg; 2137 external_module = 1; 2138 break; 2139 case 'c': 2140 cross_build = 1; 2141 break; 2142 case 'e': 2143 external_module = 1; 2144 extsym_iter = 2145 NOFAIL(malloc(sizeof(*extsym_iter))); 2146 extsym_iter->next = extsym_start; 2147 extsym_iter->file = optarg; 2148 extsym_start = extsym_iter; 2149 break; 2150 case 'm': 2151 modversions = 1; 2152 break; 2153 case 'o': 2154 dump_write = optarg; 2155 break; 2156 case 'a': 2157 all_versions = 1; 2158 break; 2159 case 's': 2160 vmlinux_section_warnings = 0; 2161 break; 2162 case 'S': 2163 sec_mismatch_verbose = 0; 2164 break; 2165 case 'w': 2166 warn_unresolved = 1; 2167 break; 2168 default: 2169 exit(1); 2170 } 2171 } 2172 2173 if (kernel_read) 2174 read_dump(kernel_read, 1); 2175 if (module_read) 2176 read_dump(module_read, 0); 2177 while (extsym_start) { 2178 read_dump(extsym_start->file, 0); 2179 extsym_iter = extsym_start->next; 2180 free(extsym_start); 2181 extsym_start = extsym_iter; 2182 } 2183 2184 while (optind < argc) 2185 read_symbols(argv[optind++]); 2186 2187 for (mod = modules; mod; mod = mod->next) { 2188 if (mod->skip) 2189 continue; 2190 check_exports(mod); 2191 } 2192 2193 err = 0; 2194 2195 for (mod = modules; mod; mod = mod->next) { 2196 char fname[strlen(mod->name) + 10]; 2197 2198 if (mod->skip) 2199 continue; 2200 2201 buf.pos = 0; 2202 2203 add_header(&buf, mod); 2204 add_intree_flag(&buf, !external_module); 2205 add_staging_flag(&buf, mod->name); 2206 err |= add_versions(&buf, mod); 2207 add_depends(&buf, mod, modules); 2208 add_moddevtable(&buf, mod); 2209 add_srcversion(&buf, mod); 2210 2211 sprintf(fname, "%s.mod.c", mod->name); 2212 write_if_changed(&buf, fname); 2213 } 2214 2215 if (dump_write) 2216 write_dump(dump_write); 2217 if (sec_mismatch_count && !sec_mismatch_verbose) 2218 warn("modpost: Found %d section mismatch(es).\n" 2219 "To see full details build your kernel with:\n" 2220 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n", 2221 sec_mismatch_count); 2222 2223 return err; 2224 } 2225