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 ".xt.prop", /* xtensa */ 831 ".xt.lit", /* xtensa */ 832 NULL 833 }; 834 835 /* 836 * This is used to find sections missing the SHF_ALLOC flag. 837 * The cause of this is often a section specified in assembler 838 * without "ax" / "aw". 839 */ 840 static void check_section(const char *modname, struct elf_info *elf, 841 Elf_Shdr *sechdr) 842 { 843 const char *sec = sech_name(elf, sechdr); 844 845 if (sechdr->sh_type == SHT_PROGBITS && 846 !(sechdr->sh_flags & SHF_ALLOC) && 847 !match(sec, section_white_list)) { 848 warn("%s (%s): unexpected non-allocatable section.\n" 849 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 850 "Note that for example <linux/init.h> contains\n" 851 "section definitions for use in .S files.\n\n", 852 modname, sec); 853 } 854 } 855 856 857 858 #define ALL_INIT_DATA_SECTIONS \ 859 ".init.setup$", ".init.rodata$", \ 860 ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$", \ 861 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$" 862 #define ALL_EXIT_DATA_SECTIONS \ 863 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$" 864 865 #define ALL_INIT_TEXT_SECTIONS \ 866 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$" 867 #define ALL_EXIT_TEXT_SECTIONS \ 868 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$" 869 870 #define ALL_PCI_INIT_SECTIONS \ 871 ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \ 872 ".pci_fixup_enable$", ".pci_fixup_resume$", \ 873 ".pci_fixup_resume_early$", ".pci_fixup_suspend$" 874 875 #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \ 876 MEM_INIT_SECTIONS 877 #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \ 878 MEM_EXIT_SECTIONS 879 880 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 881 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS 882 883 #define DATA_SECTIONS ".data$", ".data.rel$" 884 #define TEXT_SECTIONS ".text$" 885 886 #define INIT_SECTIONS ".init.*" 887 #define DEV_INIT_SECTIONS ".devinit.*" 888 #define CPU_INIT_SECTIONS ".cpuinit.*" 889 #define MEM_INIT_SECTIONS ".meminit.*" 890 891 #define EXIT_SECTIONS ".exit.*" 892 #define DEV_EXIT_SECTIONS ".devexit.*" 893 #define CPU_EXIT_SECTIONS ".cpuexit.*" 894 #define MEM_EXIT_SECTIONS ".memexit.*" 895 896 /* init data sections */ 897 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL }; 898 899 /* all init sections */ 900 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL }; 901 902 /* All init and exit sections (code + data) */ 903 static const char *init_exit_sections[] = 904 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }; 905 906 /* data section */ 907 static const char *data_sections[] = { DATA_SECTIONS, NULL }; 908 909 910 /* symbols in .data that may refer to init/exit sections */ 911 #define DEFAULT_SYMBOL_WHITE_LIST \ 912 "*driver", \ 913 "*_template", /* scsi uses *_template a lot */ \ 914 "*_timer", /* arm uses ops structures named _timer a lot */ \ 915 "*_sht", /* scsi also used *_sht to some extent */ \ 916 "*_ops", \ 917 "*_probe", \ 918 "*_probe_one", \ 919 "*_console" 920 921 static const char *head_sections[] = { ".head.text*", NULL }; 922 static const char *linker_symbols[] = 923 { "__init_begin", "_sinittext", "_einittext", NULL }; 924 925 enum mismatch { 926 TEXT_TO_ANY_INIT, 927 DATA_TO_ANY_INIT, 928 TEXT_TO_ANY_EXIT, 929 DATA_TO_ANY_EXIT, 930 XXXINIT_TO_SOME_INIT, 931 XXXEXIT_TO_SOME_EXIT, 932 ANY_INIT_TO_ANY_EXIT, 933 ANY_EXIT_TO_ANY_INIT, 934 EXPORT_TO_INIT_EXIT, 935 }; 936 937 struct sectioncheck { 938 const char *fromsec[20]; 939 const char *tosec[20]; 940 enum mismatch mismatch; 941 const char *symbol_white_list[20]; 942 }; 943 944 const struct sectioncheck sectioncheck[] = { 945 /* Do not reference init/exit code/data from 946 * normal code and data 947 */ 948 { 949 .fromsec = { TEXT_SECTIONS, NULL }, 950 .tosec = { ALL_INIT_SECTIONS, NULL }, 951 .mismatch = TEXT_TO_ANY_INIT, 952 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 953 }, 954 { 955 .fromsec = { DATA_SECTIONS, NULL }, 956 .tosec = { ALL_XXXINIT_SECTIONS, NULL }, 957 .mismatch = DATA_TO_ANY_INIT, 958 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 959 }, 960 { 961 .fromsec = { DATA_SECTIONS, NULL }, 962 .tosec = { INIT_SECTIONS, NULL }, 963 .mismatch = DATA_TO_ANY_INIT, 964 .symbol_white_list = { 965 "*_template", "*_timer", "*_sht", "*_ops", 966 "*_probe", "*_probe_one", "*_console", NULL 967 }, 968 }, 969 { 970 .fromsec = { TEXT_SECTIONS, NULL }, 971 .tosec = { ALL_EXIT_SECTIONS, NULL }, 972 .mismatch = TEXT_TO_ANY_EXIT, 973 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 974 }, 975 { 976 .fromsec = { DATA_SECTIONS, NULL }, 977 .tosec = { ALL_EXIT_SECTIONS, NULL }, 978 .mismatch = DATA_TO_ANY_EXIT, 979 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 980 }, 981 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */ 982 { 983 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 984 .tosec = { INIT_SECTIONS, NULL }, 985 .mismatch = XXXINIT_TO_SOME_INIT, 986 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 987 }, 988 /* Do not reference cpuinit code/data from meminit code/data */ 989 { 990 .fromsec = { MEM_INIT_SECTIONS, NULL }, 991 .tosec = { CPU_INIT_SECTIONS, NULL }, 992 .mismatch = XXXINIT_TO_SOME_INIT, 993 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 994 }, 995 /* Do not reference meminit code/data from cpuinit code/data */ 996 { 997 .fromsec = { CPU_INIT_SECTIONS, NULL }, 998 .tosec = { MEM_INIT_SECTIONS, NULL }, 999 .mismatch = XXXINIT_TO_SOME_INIT, 1000 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1001 }, 1002 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */ 1003 { 1004 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL }, 1005 .tosec = { EXIT_SECTIONS, NULL }, 1006 .mismatch = XXXEXIT_TO_SOME_EXIT, 1007 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1008 }, 1009 /* Do not reference cpuexit code/data from memexit code/data */ 1010 { 1011 .fromsec = { MEM_EXIT_SECTIONS, NULL }, 1012 .tosec = { CPU_EXIT_SECTIONS, NULL }, 1013 .mismatch = XXXEXIT_TO_SOME_EXIT, 1014 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1015 }, 1016 /* Do not reference memexit code/data from cpuexit code/data */ 1017 { 1018 .fromsec = { CPU_EXIT_SECTIONS, NULL }, 1019 .tosec = { MEM_EXIT_SECTIONS, NULL }, 1020 .mismatch = XXXEXIT_TO_SOME_EXIT, 1021 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1022 }, 1023 /* Do not use exit code/data from init code */ 1024 { 1025 .fromsec = { ALL_INIT_SECTIONS, NULL }, 1026 .tosec = { ALL_EXIT_SECTIONS, NULL }, 1027 .mismatch = ANY_INIT_TO_ANY_EXIT, 1028 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1029 }, 1030 /* Do not use init code/data from exit code */ 1031 { 1032 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 1033 .tosec = { ALL_INIT_SECTIONS, NULL }, 1034 .mismatch = ANY_EXIT_TO_ANY_INIT, 1035 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1036 }, 1037 { 1038 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 1039 .tosec = { INIT_SECTIONS, NULL }, 1040 .mismatch = ANY_INIT_TO_ANY_EXIT, 1041 .symbol_white_list = { NULL }, 1042 }, 1043 /* Do not export init/exit functions or data */ 1044 { 1045 .fromsec = { "__ksymtab*", NULL }, 1046 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL }, 1047 .mismatch = EXPORT_TO_INIT_EXIT, 1048 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1049 } 1050 }; 1051 1052 static const struct sectioncheck *section_mismatch( 1053 const char *fromsec, const char *tosec) 1054 { 1055 int i; 1056 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck); 1057 const struct sectioncheck *check = §ioncheck[0]; 1058 1059 for (i = 0; i < elems; i++) { 1060 if (match(fromsec, check->fromsec) && 1061 match(tosec, check->tosec)) 1062 return check; 1063 check++; 1064 } 1065 return NULL; 1066 } 1067 1068 /** 1069 * Whitelist to allow certain references to pass with no warning. 1070 * 1071 * Pattern 1: 1072 * If a module parameter is declared __initdata and permissions=0 1073 * then this is legal despite the warning generated. 1074 * We cannot see value of permissions here, so just ignore 1075 * this pattern. 1076 * The pattern is identified by: 1077 * tosec = .init.data 1078 * fromsec = .data* 1079 * atsym =__param* 1080 * 1081 * Pattern 1a: 1082 * module_param_call() ops can refer to __init set function if permissions=0 1083 * The pattern is identified by: 1084 * tosec = .init.text 1085 * fromsec = .data* 1086 * atsym = __param_ops_* 1087 * 1088 * Pattern 2: 1089 * Many drivers utilise a *driver container with references to 1090 * add, remove, probe functions etc. 1091 * These functions may often be marked __devinit and we do not want to 1092 * warn here. 1093 * the pattern is identified by: 1094 * tosec = init or exit section 1095 * fromsec = data section 1096 * atsym = *driver, *_template, *_sht, *_ops, *_probe, 1097 * *probe_one, *_console, *_timer 1098 * 1099 * Pattern 3: 1100 * Whitelist all references from .head.text to any init section 1101 * 1102 * Pattern 4: 1103 * Some symbols belong to init section but still it is ok to reference 1104 * these from non-init sections as these symbols don't have any memory 1105 * allocated for them and symbol address and value are same. So even 1106 * if init section is freed, its ok to reference those symbols. 1107 * For ex. symbols marking the init section boundaries. 1108 * This pattern is identified by 1109 * refsymname = __init_begin, _sinittext, _einittext 1110 * 1111 **/ 1112 static int secref_whitelist(const struct sectioncheck *mismatch, 1113 const char *fromsec, const char *fromsym, 1114 const char *tosec, const char *tosym) 1115 { 1116 /* Check for pattern 1 */ 1117 if (match(tosec, init_data_sections) && 1118 match(fromsec, data_sections) && 1119 (strncmp(fromsym, "__param", strlen("__param")) == 0)) 1120 return 0; 1121 1122 /* Check for pattern 1a */ 1123 if (strcmp(tosec, ".init.text") == 0 && 1124 match(fromsec, data_sections) && 1125 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0)) 1126 return 0; 1127 1128 /* Check for pattern 2 */ 1129 if (match(tosec, init_exit_sections) && 1130 match(fromsec, data_sections) && 1131 match(fromsym, mismatch->symbol_white_list)) 1132 return 0; 1133 1134 /* Check for pattern 3 */ 1135 if (match(fromsec, head_sections) && 1136 match(tosec, init_sections)) 1137 return 0; 1138 1139 /* Check for pattern 4 */ 1140 if (match(tosym, linker_symbols)) 1141 return 0; 1142 1143 return 1; 1144 } 1145 1146 /** 1147 * Find symbol based on relocation record info. 1148 * In some cases the symbol supplied is a valid symbol so 1149 * return refsym. If st_name != 0 we assume this is a valid symbol. 1150 * In other cases the symbol needs to be looked up in the symbol table 1151 * based on section and address. 1152 * **/ 1153 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr, 1154 Elf_Sym *relsym) 1155 { 1156 Elf_Sym *sym; 1157 Elf_Sym *near = NULL; 1158 Elf64_Sword distance = 20; 1159 Elf64_Sword d; 1160 unsigned int relsym_secindex; 1161 1162 if (relsym->st_name != 0) 1163 return relsym; 1164 1165 relsym_secindex = get_secindex(elf, relsym); 1166 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1167 if (get_secindex(elf, sym) != relsym_secindex) 1168 continue; 1169 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) 1170 continue; 1171 if (sym->st_value == addr) 1172 return sym; 1173 /* Find a symbol nearby - addr are maybe negative */ 1174 d = sym->st_value - addr; 1175 if (d < 0) 1176 d = addr - sym->st_value; 1177 if (d < distance) { 1178 distance = d; 1179 near = sym; 1180 } 1181 } 1182 /* We need a close match */ 1183 if (distance < 20) 1184 return near; 1185 else 1186 return NULL; 1187 } 1188 1189 static inline int is_arm_mapping_symbol(const char *str) 1190 { 1191 return str[0] == '$' && strchr("atd", str[1]) 1192 && (str[2] == '\0' || str[2] == '.'); 1193 } 1194 1195 /* 1196 * If there's no name there, ignore it; likewise, ignore it if it's 1197 * one of the magic symbols emitted used by current ARM tools. 1198 * 1199 * Otherwise if find_symbols_between() returns those symbols, they'll 1200 * fail the whitelist tests and cause lots of false alarms ... fixable 1201 * only by merging __exit and __init sections into __text, bloating 1202 * the kernel (which is especially evil on embedded platforms). 1203 */ 1204 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 1205 { 1206 const char *name = elf->strtab + sym->st_name; 1207 1208 if (!name || !strlen(name)) 1209 return 0; 1210 return !is_arm_mapping_symbol(name); 1211 } 1212 1213 /* 1214 * Find symbols before or equal addr and after addr - in the section sec. 1215 * If we find two symbols with equal offset prefer one with a valid name. 1216 * The ELF format may have a better way to detect what type of symbol 1217 * it is, but this works for now. 1218 **/ 1219 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr, 1220 const char *sec) 1221 { 1222 Elf_Sym *sym; 1223 Elf_Sym *near = NULL; 1224 Elf_Addr distance = ~0; 1225 1226 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1227 const char *symsec; 1228 1229 if (is_shndx_special(sym->st_shndx)) 1230 continue; 1231 symsec = sec_name(elf, get_secindex(elf, sym)); 1232 if (strcmp(symsec, sec) != 0) 1233 continue; 1234 if (!is_valid_name(elf, sym)) 1235 continue; 1236 if (sym->st_value <= addr) { 1237 if ((addr - sym->st_value) < distance) { 1238 distance = addr - sym->st_value; 1239 near = sym; 1240 } else if ((addr - sym->st_value) == distance) { 1241 near = sym; 1242 } 1243 } 1244 } 1245 return near; 1246 } 1247 1248 /* 1249 * Convert a section name to the function/data attribute 1250 * .init.text => __init 1251 * .cpuinit.data => __cpudata 1252 * .memexitconst => __memconst 1253 * etc. 1254 * 1255 * The memory of returned value has been allocated on a heap. The user of this 1256 * method should free it after usage. 1257 */ 1258 static char *sec2annotation(const char *s) 1259 { 1260 if (match(s, init_exit_sections)) { 1261 char *p = malloc(20); 1262 char *r = p; 1263 1264 *p++ = '_'; 1265 *p++ = '_'; 1266 if (*s == '.') 1267 s++; 1268 while (*s && *s != '.') 1269 *p++ = *s++; 1270 *p = '\0'; 1271 if (*s == '.') 1272 s++; 1273 if (strstr(s, "rodata") != NULL) 1274 strcat(p, "const "); 1275 else if (strstr(s, "data") != NULL) 1276 strcat(p, "data "); 1277 else 1278 strcat(p, " "); 1279 return r; 1280 } else { 1281 return strdup(""); 1282 } 1283 } 1284 1285 static int is_function(Elf_Sym *sym) 1286 { 1287 if (sym) 1288 return ELF_ST_TYPE(sym->st_info) == STT_FUNC; 1289 else 1290 return -1; 1291 } 1292 1293 static void print_section_list(const char * const list[20]) 1294 { 1295 const char *const *s = list; 1296 1297 while (*s) { 1298 fprintf(stderr, "%s", *s); 1299 s++; 1300 if (*s) 1301 fprintf(stderr, ", "); 1302 } 1303 fprintf(stderr, "\n"); 1304 } 1305 1306 /* 1307 * Print a warning about a section mismatch. 1308 * Try to find symbols near it so user can find it. 1309 * Check whitelist before warning - it may be a false positive. 1310 */ 1311 static void report_sec_mismatch(const char *modname, 1312 const struct sectioncheck *mismatch, 1313 const char *fromsec, 1314 unsigned long long fromaddr, 1315 const char *fromsym, 1316 int from_is_func, 1317 const char *tosec, const char *tosym, 1318 int to_is_func) 1319 { 1320 const char *from, *from_p; 1321 const char *to, *to_p; 1322 char *prl_from; 1323 char *prl_to; 1324 1325 switch (from_is_func) { 1326 case 0: from = "variable"; from_p = ""; break; 1327 case 1: from = "function"; from_p = "()"; break; 1328 default: from = "(unknown reference)"; from_p = ""; break; 1329 } 1330 switch (to_is_func) { 1331 case 0: to = "variable"; to_p = ""; break; 1332 case 1: to = "function"; to_p = "()"; break; 1333 default: to = "(unknown reference)"; to_p = ""; break; 1334 } 1335 1336 sec_mismatch_count++; 1337 if (!sec_mismatch_verbose) 1338 return; 1339 1340 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s " 1341 "to the %s %s:%s%s\n", 1342 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec, 1343 tosym, to_p); 1344 1345 switch (mismatch->mismatch) { 1346 case TEXT_TO_ANY_INIT: 1347 prl_from = sec2annotation(fromsec); 1348 prl_to = sec2annotation(tosec); 1349 fprintf(stderr, 1350 "The function %s%s() references\n" 1351 "the %s %s%s%s.\n" 1352 "This is often because %s lacks a %s\n" 1353 "annotation or the annotation of %s is wrong.\n", 1354 prl_from, fromsym, 1355 to, prl_to, tosym, to_p, 1356 fromsym, prl_to, tosym); 1357 free(prl_from); 1358 free(prl_to); 1359 break; 1360 case DATA_TO_ANY_INIT: { 1361 prl_to = sec2annotation(tosec); 1362 fprintf(stderr, 1363 "The variable %s references\n" 1364 "the %s %s%s%s\n" 1365 "If the reference is valid then annotate the\n" 1366 "variable with __init* or __refdata (see linux/init.h) " 1367 "or name the variable:\n", 1368 fromsym, to, prl_to, tosym, to_p); 1369 print_section_list(mismatch->symbol_white_list); 1370 free(prl_to); 1371 break; 1372 } 1373 case TEXT_TO_ANY_EXIT: 1374 prl_to = sec2annotation(tosec); 1375 fprintf(stderr, 1376 "The function %s() references a %s in an exit section.\n" 1377 "Often the %s %s%s has valid usage outside the exit section\n" 1378 "and the fix is to remove the %sannotation of %s.\n", 1379 fromsym, to, to, tosym, to_p, prl_to, tosym); 1380 free(prl_to); 1381 break; 1382 case DATA_TO_ANY_EXIT: { 1383 prl_to = sec2annotation(tosec); 1384 fprintf(stderr, 1385 "The variable %s references\n" 1386 "the %s %s%s%s\n" 1387 "If the reference is valid then annotate the\n" 1388 "variable with __exit* (see linux/init.h) or " 1389 "name the variable:\n", 1390 fromsym, to, prl_to, tosym, to_p); 1391 print_section_list(mismatch->symbol_white_list); 1392 free(prl_to); 1393 break; 1394 } 1395 case XXXINIT_TO_SOME_INIT: 1396 case XXXEXIT_TO_SOME_EXIT: 1397 prl_from = sec2annotation(fromsec); 1398 prl_to = sec2annotation(tosec); 1399 fprintf(stderr, 1400 "The %s %s%s%s references\n" 1401 "a %s %s%s%s.\n" 1402 "If %s is only used by %s then\n" 1403 "annotate %s with a matching annotation.\n", 1404 from, prl_from, fromsym, from_p, 1405 to, prl_to, tosym, to_p, 1406 tosym, fromsym, tosym); 1407 free(prl_from); 1408 free(prl_to); 1409 break; 1410 case ANY_INIT_TO_ANY_EXIT: 1411 prl_from = sec2annotation(fromsec); 1412 prl_to = sec2annotation(tosec); 1413 fprintf(stderr, 1414 "The %s %s%s%s references\n" 1415 "a %s %s%s%s.\n" 1416 "This is often seen when error handling " 1417 "in the init function\n" 1418 "uses functionality in the exit path.\n" 1419 "The fix is often to remove the %sannotation of\n" 1420 "%s%s so it may be used outside an exit section.\n", 1421 from, prl_from, fromsym, from_p, 1422 to, prl_to, tosym, to_p, 1423 prl_to, tosym, to_p); 1424 free(prl_from); 1425 free(prl_to); 1426 break; 1427 case ANY_EXIT_TO_ANY_INIT: 1428 prl_from = sec2annotation(fromsec); 1429 prl_to = sec2annotation(tosec); 1430 fprintf(stderr, 1431 "The %s %s%s%s references\n" 1432 "a %s %s%s%s.\n" 1433 "This is often seen when error handling " 1434 "in the exit function\n" 1435 "uses functionality in the init path.\n" 1436 "The fix is often to remove the %sannotation of\n" 1437 "%s%s so it may be used outside an init section.\n", 1438 from, prl_from, fromsym, from_p, 1439 to, prl_to, tosym, to_p, 1440 prl_to, tosym, to_p); 1441 free(prl_from); 1442 free(prl_to); 1443 break; 1444 case EXPORT_TO_INIT_EXIT: 1445 prl_to = sec2annotation(tosec); 1446 fprintf(stderr, 1447 "The symbol %s is exported and annotated %s\n" 1448 "Fix this by removing the %sannotation of %s " 1449 "or drop the export.\n", 1450 tosym, prl_to, prl_to, tosym); 1451 free(prl_to); 1452 break; 1453 } 1454 fprintf(stderr, "\n"); 1455 } 1456 1457 static void check_section_mismatch(const char *modname, struct elf_info *elf, 1458 Elf_Rela *r, Elf_Sym *sym, const char *fromsec) 1459 { 1460 const char *tosec; 1461 const struct sectioncheck *mismatch; 1462 1463 tosec = sec_name(elf, get_secindex(elf, sym)); 1464 mismatch = section_mismatch(fromsec, tosec); 1465 if (mismatch) { 1466 Elf_Sym *to; 1467 Elf_Sym *from; 1468 const char *tosym; 1469 const char *fromsym; 1470 1471 from = find_elf_symbol2(elf, r->r_offset, fromsec); 1472 fromsym = sym_name(elf, from); 1473 to = find_elf_symbol(elf, r->r_addend, sym); 1474 tosym = sym_name(elf, to); 1475 1476 /* check whitelist - we may ignore it */ 1477 if (secref_whitelist(mismatch, 1478 fromsec, fromsym, tosec, tosym)) { 1479 report_sec_mismatch(modname, mismatch, 1480 fromsec, r->r_offset, fromsym, 1481 is_function(from), tosec, tosym, 1482 is_function(to)); 1483 } 1484 } 1485 } 1486 1487 static unsigned int *reloc_location(struct elf_info *elf, 1488 Elf_Shdr *sechdr, Elf_Rela *r) 1489 { 1490 Elf_Shdr *sechdrs = elf->sechdrs; 1491 int section = sechdr->sh_info; 1492 1493 return (void *)elf->hdr + sechdrs[section].sh_offset + 1494 r->r_offset; 1495 } 1496 1497 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1498 { 1499 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1500 unsigned int *location = reloc_location(elf, sechdr, r); 1501 1502 switch (r_typ) { 1503 case R_386_32: 1504 r->r_addend = TO_NATIVE(*location); 1505 break; 1506 case R_386_PC32: 1507 r->r_addend = TO_NATIVE(*location) + 4; 1508 /* For CONFIG_RELOCATABLE=y */ 1509 if (elf->hdr->e_type == ET_EXEC) 1510 r->r_addend += r->r_offset; 1511 break; 1512 } 1513 return 0; 1514 } 1515 1516 #ifndef R_ARM_CALL 1517 #define R_ARM_CALL 28 1518 #endif 1519 #ifndef R_ARM_JUMP24 1520 #define R_ARM_JUMP24 29 1521 #endif 1522 1523 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1524 { 1525 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1526 1527 switch (r_typ) { 1528 case R_ARM_ABS32: 1529 /* From ARM ABI: (S + A) | T */ 1530 r->r_addend = (int)(long) 1531 (elf->symtab_start + ELF_R_SYM(r->r_info)); 1532 break; 1533 case R_ARM_PC24: 1534 case R_ARM_CALL: 1535 case R_ARM_JUMP24: 1536 /* From ARM ABI: ((S + A) | T) - P */ 1537 r->r_addend = (int)(long)(elf->hdr + 1538 sechdr->sh_offset + 1539 (r->r_offset - sechdr->sh_addr)); 1540 break; 1541 default: 1542 return 1; 1543 } 1544 return 0; 1545 } 1546 1547 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1548 { 1549 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1550 unsigned int *location = reloc_location(elf, sechdr, r); 1551 unsigned int inst; 1552 1553 if (r_typ == R_MIPS_HI16) 1554 return 1; /* skip this */ 1555 inst = TO_NATIVE(*location); 1556 switch (r_typ) { 1557 case R_MIPS_LO16: 1558 r->r_addend = inst & 0xffff; 1559 break; 1560 case R_MIPS_26: 1561 r->r_addend = (inst & 0x03ffffff) << 2; 1562 break; 1563 case R_MIPS_32: 1564 r->r_addend = inst; 1565 break; 1566 } 1567 return 0; 1568 } 1569 1570 static void section_rela(const char *modname, struct elf_info *elf, 1571 Elf_Shdr *sechdr) 1572 { 1573 Elf_Sym *sym; 1574 Elf_Rela *rela; 1575 Elf_Rela r; 1576 unsigned int r_sym; 1577 const char *fromsec; 1578 1579 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; 1580 Elf_Rela *stop = (void *)start + sechdr->sh_size; 1581 1582 fromsec = sech_name(elf, sechdr); 1583 fromsec += strlen(".rela"); 1584 /* if from section (name) is know good then skip it */ 1585 if (match(fromsec, section_white_list)) 1586 return; 1587 1588 for (rela = start; rela < stop; rela++) { 1589 r.r_offset = TO_NATIVE(rela->r_offset); 1590 #if KERNEL_ELFCLASS == ELFCLASS64 1591 if (elf->hdr->e_machine == EM_MIPS) { 1592 unsigned int r_typ; 1593 r_sym = ELF64_MIPS_R_SYM(rela->r_info); 1594 r_sym = TO_NATIVE(r_sym); 1595 r_typ = ELF64_MIPS_R_TYPE(rela->r_info); 1596 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1597 } else { 1598 r.r_info = TO_NATIVE(rela->r_info); 1599 r_sym = ELF_R_SYM(r.r_info); 1600 } 1601 #else 1602 r.r_info = TO_NATIVE(rela->r_info); 1603 r_sym = ELF_R_SYM(r.r_info); 1604 #endif 1605 r.r_addend = TO_NATIVE(rela->r_addend); 1606 sym = elf->symtab_start + r_sym; 1607 /* Skip special sections */ 1608 if (is_shndx_special(sym->st_shndx)) 1609 continue; 1610 check_section_mismatch(modname, elf, &r, sym, fromsec); 1611 } 1612 } 1613 1614 static void section_rel(const char *modname, struct elf_info *elf, 1615 Elf_Shdr *sechdr) 1616 { 1617 Elf_Sym *sym; 1618 Elf_Rel *rel; 1619 Elf_Rela r; 1620 unsigned int r_sym; 1621 const char *fromsec; 1622 1623 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset; 1624 Elf_Rel *stop = (void *)start + sechdr->sh_size; 1625 1626 fromsec = sech_name(elf, sechdr); 1627 fromsec += strlen(".rel"); 1628 /* if from section (name) is know good then skip it */ 1629 if (match(fromsec, section_white_list)) 1630 return; 1631 1632 for (rel = start; rel < stop; rel++) { 1633 r.r_offset = TO_NATIVE(rel->r_offset); 1634 #if KERNEL_ELFCLASS == ELFCLASS64 1635 if (elf->hdr->e_machine == EM_MIPS) { 1636 unsigned int r_typ; 1637 r_sym = ELF64_MIPS_R_SYM(rel->r_info); 1638 r_sym = TO_NATIVE(r_sym); 1639 r_typ = ELF64_MIPS_R_TYPE(rel->r_info); 1640 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1641 } else { 1642 r.r_info = TO_NATIVE(rel->r_info); 1643 r_sym = ELF_R_SYM(r.r_info); 1644 } 1645 #else 1646 r.r_info = TO_NATIVE(rel->r_info); 1647 r_sym = ELF_R_SYM(r.r_info); 1648 #endif 1649 r.r_addend = 0; 1650 switch (elf->hdr->e_machine) { 1651 case EM_386: 1652 if (addend_386_rel(elf, sechdr, &r)) 1653 continue; 1654 break; 1655 case EM_ARM: 1656 if (addend_arm_rel(elf, sechdr, &r)) 1657 continue; 1658 break; 1659 case EM_MIPS: 1660 if (addend_mips_rel(elf, sechdr, &r)) 1661 continue; 1662 break; 1663 } 1664 sym = elf->symtab_start + r_sym; 1665 /* Skip special sections */ 1666 if (is_shndx_special(sym->st_shndx)) 1667 continue; 1668 check_section_mismatch(modname, elf, &r, sym, fromsec); 1669 } 1670 } 1671 1672 /** 1673 * A module includes a number of sections that are discarded 1674 * either when loaded or when used as built-in. 1675 * For loaded modules all functions marked __init and all data 1676 * marked __initdata will be discarded when the module has been initialized. 1677 * Likewise for modules used built-in the sections marked __exit 1678 * are discarded because __exit marked function are supposed to be called 1679 * only when a module is unloaded which never happens for built-in modules. 1680 * The check_sec_ref() function traverses all relocation records 1681 * to find all references to a section that reference a section that will 1682 * be discarded and warns about it. 1683 **/ 1684 static void check_sec_ref(struct module *mod, const char *modname, 1685 struct elf_info *elf) 1686 { 1687 int i; 1688 Elf_Shdr *sechdrs = elf->sechdrs; 1689 1690 /* Walk through all sections */ 1691 for (i = 0; i < elf->num_sections; i++) { 1692 check_section(modname, elf, &elf->sechdrs[i]); 1693 /* We want to process only relocation sections and not .init */ 1694 if (sechdrs[i].sh_type == SHT_RELA) 1695 section_rela(modname, elf, &elf->sechdrs[i]); 1696 else if (sechdrs[i].sh_type == SHT_REL) 1697 section_rel(modname, elf, &elf->sechdrs[i]); 1698 } 1699 } 1700 1701 static void read_symbols(char *modname) 1702 { 1703 const char *symname; 1704 char *version; 1705 char *license; 1706 struct module *mod; 1707 struct elf_info info = { }; 1708 Elf_Sym *sym; 1709 1710 if (!parse_elf(&info, modname)) 1711 return; 1712 1713 mod = new_module(modname); 1714 1715 /* When there's no vmlinux, don't print warnings about 1716 * unresolved symbols (since there'll be too many ;) */ 1717 if (is_vmlinux(modname)) { 1718 have_vmlinux = 1; 1719 mod->skip = 1; 1720 } 1721 1722 license = get_modinfo(info.modinfo, info.modinfo_len, "license"); 1723 if (info.modinfo && !license && !is_vmlinux(modname)) 1724 warn("modpost: missing MODULE_LICENSE() in %s\n" 1725 "see include/linux/module.h for " 1726 "more information\n", modname); 1727 while (license) { 1728 if (license_is_gpl_compatible(license)) 1729 mod->gpl_compatible = 1; 1730 else { 1731 mod->gpl_compatible = 0; 1732 break; 1733 } 1734 license = get_next_modinfo(info.modinfo, info.modinfo_len, 1735 "license", license); 1736 } 1737 1738 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1739 symname = info.strtab + sym->st_name; 1740 1741 handle_modversions(mod, &info, sym, symname); 1742 handle_moddevtable(mod, &info, sym, symname); 1743 } 1744 if (!is_vmlinux(modname) || 1745 (is_vmlinux(modname) && vmlinux_section_warnings)) 1746 check_sec_ref(mod, modname, &info); 1747 1748 version = get_modinfo(info.modinfo, info.modinfo_len, "version"); 1749 if (version) 1750 maybe_frob_rcs_version(modname, version, info.modinfo, 1751 version - (char *)info.hdr); 1752 if (version || (all_versions && !is_vmlinux(modname))) 1753 get_src_version(modname, mod->srcversion, 1754 sizeof(mod->srcversion)-1); 1755 1756 parse_elf_finish(&info); 1757 1758 /* Our trick to get versioning for module struct etc. - it's 1759 * never passed as an argument to an exported function, so 1760 * the automatic versioning doesn't pick it up, but it's really 1761 * important anyhow */ 1762 if (modversions) 1763 mod->unres = alloc_symbol("module_layout", 0, mod->unres); 1764 } 1765 1766 #define SZ 500 1767 1768 /* We first write the generated file into memory using the 1769 * following helper, then compare to the file on disk and 1770 * only update the later if anything changed */ 1771 1772 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1773 const char *fmt, ...) 1774 { 1775 char tmp[SZ]; 1776 int len; 1777 va_list ap; 1778 1779 va_start(ap, fmt); 1780 len = vsnprintf(tmp, SZ, fmt, ap); 1781 buf_write(buf, tmp, len); 1782 va_end(ap); 1783 } 1784 1785 void buf_write(struct buffer *buf, const char *s, int len) 1786 { 1787 if (buf->size - buf->pos < len) { 1788 buf->size += len + SZ; 1789 buf->p = realloc(buf->p, buf->size); 1790 } 1791 strncpy(buf->p + buf->pos, s, len); 1792 buf->pos += len; 1793 } 1794 1795 static void check_for_gpl_usage(enum export exp, const char *m, const char *s) 1796 { 1797 const char *e = is_vmlinux(m) ?"":".ko"; 1798 1799 switch (exp) { 1800 case export_gpl: 1801 fatal("modpost: GPL-incompatible module %s%s " 1802 "uses GPL-only symbol '%s'\n", m, e, s); 1803 break; 1804 case export_unused_gpl: 1805 fatal("modpost: GPL-incompatible module %s%s " 1806 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); 1807 break; 1808 case export_gpl_future: 1809 warn("modpost: GPL-incompatible module %s%s " 1810 "uses future GPL-only symbol '%s'\n", m, e, s); 1811 break; 1812 case export_plain: 1813 case export_unused: 1814 case export_unknown: 1815 /* ignore */ 1816 break; 1817 } 1818 } 1819 1820 static void check_for_unused(enum export exp, const char *m, const char *s) 1821 { 1822 const char *e = is_vmlinux(m) ?"":".ko"; 1823 1824 switch (exp) { 1825 case export_unused: 1826 case export_unused_gpl: 1827 warn("modpost: module %s%s " 1828 "uses symbol '%s' marked UNUSED\n", m, e, s); 1829 break; 1830 default: 1831 /* ignore */ 1832 break; 1833 } 1834 } 1835 1836 static void check_exports(struct module *mod) 1837 { 1838 struct symbol *s, *exp; 1839 1840 for (s = mod->unres; s; s = s->next) { 1841 const char *basename; 1842 exp = find_symbol(s->name); 1843 if (!exp || exp->module == mod) 1844 continue; 1845 basename = strrchr(mod->name, '/'); 1846 if (basename) 1847 basename++; 1848 else 1849 basename = mod->name; 1850 if (!mod->gpl_compatible) 1851 check_for_gpl_usage(exp->export, basename, exp->name); 1852 check_for_unused(exp->export, basename, exp->name); 1853 } 1854 } 1855 1856 /** 1857 * Header for the generated file 1858 **/ 1859 static void add_header(struct buffer *b, struct module *mod) 1860 { 1861 buf_printf(b, "#include <linux/module.h>\n"); 1862 buf_printf(b, "#include <linux/vermagic.h>\n"); 1863 buf_printf(b, "#include <linux/compiler.h>\n"); 1864 buf_printf(b, "\n"); 1865 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1866 buf_printf(b, "\n"); 1867 buf_printf(b, "struct module __this_module\n"); 1868 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); 1869 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1870 if (mod->has_init) 1871 buf_printf(b, "\t.init = init_module,\n"); 1872 if (mod->has_cleanup) 1873 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1874 "\t.exit = cleanup_module,\n" 1875 "#endif\n"); 1876 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1877 buf_printf(b, "};\n"); 1878 } 1879 1880 static void add_intree_flag(struct buffer *b, int is_intree) 1881 { 1882 if (is_intree) 1883 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1884 } 1885 1886 static void add_staging_flag(struct buffer *b, const char *name) 1887 { 1888 static const char *staging_dir = "drivers/staging"; 1889 1890 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0) 1891 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1892 } 1893 1894 /** 1895 * Record CRCs for unresolved symbols 1896 **/ 1897 static int add_versions(struct buffer *b, struct module *mod) 1898 { 1899 struct symbol *s, *exp; 1900 int err = 0; 1901 1902 for (s = mod->unres; s; s = s->next) { 1903 exp = find_symbol(s->name); 1904 if (!exp || exp->module == mod) { 1905 if (have_vmlinux && !s->weak) { 1906 if (warn_unresolved) { 1907 warn("\"%s\" [%s.ko] undefined!\n", 1908 s->name, mod->name); 1909 } else { 1910 merror("\"%s\" [%s.ko] undefined!\n", 1911 s->name, mod->name); 1912 err = 1; 1913 } 1914 } 1915 continue; 1916 } 1917 s->module = exp->module; 1918 s->crc_valid = exp->crc_valid; 1919 s->crc = exp->crc; 1920 } 1921 1922 if (!modversions) 1923 return err; 1924 1925 buf_printf(b, "\n"); 1926 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1927 buf_printf(b, "__used\n"); 1928 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); 1929 1930 for (s = mod->unres; s; s = s->next) { 1931 if (!s->module) 1932 continue; 1933 if (!s->crc_valid) { 1934 warn("\"%s\" [%s.ko] has no CRC!\n", 1935 s->name, mod->name); 1936 continue; 1937 } 1938 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); 1939 } 1940 1941 buf_printf(b, "};\n"); 1942 1943 return err; 1944 } 1945 1946 static void add_depends(struct buffer *b, struct module *mod, 1947 struct module *modules) 1948 { 1949 struct symbol *s; 1950 struct module *m; 1951 int first = 1; 1952 1953 for (m = modules; m; m = m->next) 1954 m->seen = is_vmlinux(m->name); 1955 1956 buf_printf(b, "\n"); 1957 buf_printf(b, "static const char __module_depends[]\n"); 1958 buf_printf(b, "__used\n"); 1959 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); 1960 buf_printf(b, "\"depends="); 1961 for (s = mod->unres; s; s = s->next) { 1962 const char *p; 1963 if (!s->module) 1964 continue; 1965 1966 if (s->module->seen) 1967 continue; 1968 1969 s->module->seen = 1; 1970 p = strrchr(s->module->name, '/'); 1971 if (p) 1972 p++; 1973 else 1974 p = s->module->name; 1975 buf_printf(b, "%s%s", first ? "" : ",", p); 1976 first = 0; 1977 } 1978 buf_printf(b, "\";\n"); 1979 } 1980 1981 static void add_srcversion(struct buffer *b, struct module *mod) 1982 { 1983 if (mod->srcversion[0]) { 1984 buf_printf(b, "\n"); 1985 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1986 mod->srcversion); 1987 } 1988 } 1989 1990 static void write_if_changed(struct buffer *b, const char *fname) 1991 { 1992 char *tmp; 1993 FILE *file; 1994 struct stat st; 1995 1996 file = fopen(fname, "r"); 1997 if (!file) 1998 goto write; 1999 2000 if (fstat(fileno(file), &st) < 0) 2001 goto close_write; 2002 2003 if (st.st_size != b->pos) 2004 goto close_write; 2005 2006 tmp = NOFAIL(malloc(b->pos)); 2007 if (fread(tmp, 1, b->pos, file) != b->pos) 2008 goto free_write; 2009 2010 if (memcmp(tmp, b->p, b->pos) != 0) 2011 goto free_write; 2012 2013 free(tmp); 2014 fclose(file); 2015 return; 2016 2017 free_write: 2018 free(tmp); 2019 close_write: 2020 fclose(file); 2021 write: 2022 file = fopen(fname, "w"); 2023 if (!file) { 2024 perror(fname); 2025 exit(1); 2026 } 2027 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2028 perror(fname); 2029 exit(1); 2030 } 2031 fclose(file); 2032 } 2033 2034 /* parse Module.symvers file. line format: 2035 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] 2036 **/ 2037 static void read_dump(const char *fname, unsigned int kernel) 2038 { 2039 unsigned long size, pos = 0; 2040 void *file = grab_file(fname, &size); 2041 char *line; 2042 2043 if (!file) 2044 /* No symbol versions, silently ignore */ 2045 return; 2046 2047 while ((line = get_next_line(&pos, file, size))) { 2048 char *symname, *modname, *d, *export, *end; 2049 unsigned int crc; 2050 struct module *mod; 2051 struct symbol *s; 2052 2053 if (!(symname = strchr(line, '\t'))) 2054 goto fail; 2055 *symname++ = '\0'; 2056 if (!(modname = strchr(symname, '\t'))) 2057 goto fail; 2058 *modname++ = '\0'; 2059 if ((export = strchr(modname, '\t')) != NULL) 2060 *export++ = '\0'; 2061 if (export && ((end = strchr(export, '\t')) != NULL)) 2062 *end = '\0'; 2063 crc = strtoul(line, &d, 16); 2064 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2065 goto fail; 2066 mod = find_module(modname); 2067 if (!mod) { 2068 if (is_vmlinux(modname)) 2069 have_vmlinux = 1; 2070 mod = new_module(modname); 2071 mod->skip = 1; 2072 } 2073 s = sym_add_exported(symname, mod, export_no(export)); 2074 s->kernel = kernel; 2075 s->preloaded = 1; 2076 sym_update_crc(symname, mod, crc, export_no(export)); 2077 } 2078 return; 2079 fail: 2080 fatal("parse error in symbol dump file\n"); 2081 } 2082 2083 /* For normal builds always dump all symbols. 2084 * For external modules only dump symbols 2085 * that are not read from kernel Module.symvers. 2086 **/ 2087 static int dump_sym(struct symbol *sym) 2088 { 2089 if (!external_module) 2090 return 1; 2091 if (sym->vmlinux || sym->kernel) 2092 return 0; 2093 return 1; 2094 } 2095 2096 static void write_dump(const char *fname) 2097 { 2098 struct buffer buf = { }; 2099 struct symbol *symbol; 2100 int n; 2101 2102 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { 2103 symbol = symbolhash[n]; 2104 while (symbol) { 2105 if (dump_sym(symbol)) 2106 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", 2107 symbol->crc, symbol->name, 2108 symbol->module->name, 2109 export_str(symbol->export)); 2110 symbol = symbol->next; 2111 } 2112 } 2113 write_if_changed(&buf, fname); 2114 } 2115 2116 struct ext_sym_list { 2117 struct ext_sym_list *next; 2118 const char *file; 2119 }; 2120 2121 int main(int argc, char **argv) 2122 { 2123 struct module *mod; 2124 struct buffer buf = { }; 2125 char *kernel_read = NULL, *module_read = NULL; 2126 char *dump_write = NULL; 2127 int opt; 2128 int err; 2129 struct ext_sym_list *extsym_iter; 2130 struct ext_sym_list *extsym_start = NULL; 2131 2132 while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) { 2133 switch (opt) { 2134 case 'i': 2135 kernel_read = optarg; 2136 break; 2137 case 'I': 2138 module_read = optarg; 2139 external_module = 1; 2140 break; 2141 case 'c': 2142 cross_build = 1; 2143 break; 2144 case 'e': 2145 external_module = 1; 2146 extsym_iter = 2147 NOFAIL(malloc(sizeof(*extsym_iter))); 2148 extsym_iter->next = extsym_start; 2149 extsym_iter->file = optarg; 2150 extsym_start = extsym_iter; 2151 break; 2152 case 'm': 2153 modversions = 1; 2154 break; 2155 case 'o': 2156 dump_write = optarg; 2157 break; 2158 case 'a': 2159 all_versions = 1; 2160 break; 2161 case 's': 2162 vmlinux_section_warnings = 0; 2163 break; 2164 case 'S': 2165 sec_mismatch_verbose = 0; 2166 break; 2167 case 'w': 2168 warn_unresolved = 1; 2169 break; 2170 default: 2171 exit(1); 2172 } 2173 } 2174 2175 if (kernel_read) 2176 read_dump(kernel_read, 1); 2177 if (module_read) 2178 read_dump(module_read, 0); 2179 while (extsym_start) { 2180 read_dump(extsym_start->file, 0); 2181 extsym_iter = extsym_start->next; 2182 free(extsym_start); 2183 extsym_start = extsym_iter; 2184 } 2185 2186 while (optind < argc) 2187 read_symbols(argv[optind++]); 2188 2189 for (mod = modules; mod; mod = mod->next) { 2190 if (mod->skip) 2191 continue; 2192 check_exports(mod); 2193 } 2194 2195 err = 0; 2196 2197 for (mod = modules; mod; mod = mod->next) { 2198 char fname[strlen(mod->name) + 10]; 2199 2200 if (mod->skip) 2201 continue; 2202 2203 buf.pos = 0; 2204 2205 add_header(&buf, mod); 2206 add_intree_flag(&buf, !external_module); 2207 add_staging_flag(&buf, mod->name); 2208 err |= add_versions(&buf, mod); 2209 add_depends(&buf, mod, modules); 2210 add_moddevtable(&buf, mod); 2211 add_srcversion(&buf, mod); 2212 2213 sprintf(fname, "%s.mod.c", mod->name); 2214 write_if_changed(&buf, fname); 2215 } 2216 2217 if (dump_write) 2218 write_dump(dump_write); 2219 if (sec_mismatch_count && !sec_mismatch_verbose) 2220 warn("modpost: Found %d section mismatch(es).\n" 2221 "To see full details build your kernel with:\n" 2222 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n", 2223 sec_mismatch_count); 2224 2225 return err; 2226 } 2227