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 <limits.h> 19 #include <stdbool.h> 20 #include <errno.h> 21 #include "modpost.h" 22 #include "../../include/generated/autoconf.h" 23 #include "../../include/linux/license.h" 24 #include "../../include/linux/export.h" 25 26 /* Are we using CONFIG_MODVERSIONS? */ 27 static int modversions = 0; 28 /* Warn about undefined symbols? (do so if we have vmlinux) */ 29 static int have_vmlinux = 0; 30 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 31 static int all_versions = 0; 32 /* If we are modposting external module set to 1 */ 33 static int external_module = 0; 34 /* Warn about section mismatch in vmlinux if set to 1 */ 35 static int vmlinux_section_warnings = 1; 36 /* Only warn about unresolved symbols */ 37 static int warn_unresolved = 0; 38 /* How a symbol is exported */ 39 static int sec_mismatch_count = 0; 40 static int sec_mismatch_verbose = 1; 41 /* ignore missing files */ 42 static int ignore_missing_files; 43 44 enum export { 45 export_plain, export_unused, export_gpl, 46 export_unused_gpl, export_gpl_future, export_unknown 47 }; 48 49 #define PRINTF __attribute__ ((format (printf, 1, 2))) 50 51 PRINTF void fatal(const char *fmt, ...) 52 { 53 va_list arglist; 54 55 fprintf(stderr, "FATAL: "); 56 57 va_start(arglist, fmt); 58 vfprintf(stderr, fmt, arglist); 59 va_end(arglist); 60 61 exit(1); 62 } 63 64 PRINTF void warn(const char *fmt, ...) 65 { 66 va_list arglist; 67 68 fprintf(stderr, "WARNING: "); 69 70 va_start(arglist, fmt); 71 vfprintf(stderr, fmt, arglist); 72 va_end(arglist); 73 } 74 75 PRINTF void merror(const char *fmt, ...) 76 { 77 va_list arglist; 78 79 fprintf(stderr, "ERROR: "); 80 81 va_start(arglist, fmt); 82 vfprintf(stderr, fmt, arglist); 83 va_end(arglist); 84 } 85 86 static inline bool strends(const char *str, const char *postfix) 87 { 88 if (strlen(str) < strlen(postfix)) 89 return false; 90 91 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; 92 } 93 94 static int is_vmlinux(const char *modname) 95 { 96 const char *myname; 97 98 myname = strrchr(modname, '/'); 99 if (myname) 100 myname++; 101 else 102 myname = modname; 103 104 return (strcmp(myname, "vmlinux") == 0) || 105 (strcmp(myname, "vmlinux.o") == 0); 106 } 107 108 void *do_nofail(void *ptr, const char *expr) 109 { 110 if (!ptr) 111 fatal("modpost: Memory allocation failure: %s.\n", expr); 112 113 return ptr; 114 } 115 116 /* A list of all modules we processed */ 117 static struct module *modules; 118 119 static struct module *find_module(char *modname) 120 { 121 struct module *mod; 122 123 for (mod = modules; mod; mod = mod->next) 124 if (strcmp(mod->name, modname) == 0) 125 break; 126 return mod; 127 } 128 129 static struct module *new_module(const char *modname) 130 { 131 struct module *mod; 132 char *p; 133 134 mod = NOFAIL(malloc(sizeof(*mod))); 135 memset(mod, 0, sizeof(*mod)); 136 p = NOFAIL(strdup(modname)); 137 138 /* strip trailing .o */ 139 if (strends(p, ".o")) { 140 p[strlen(p) - 2] = '\0'; 141 mod->is_dot_o = 1; 142 } 143 144 /* add to list */ 145 mod->name = p; 146 mod->gpl_compatible = -1; 147 mod->next = modules; 148 modules = mod; 149 150 return mod; 151 } 152 153 /* A hash of all exported symbols, 154 * struct symbol is also used for lists of unresolved symbols */ 155 156 #define SYMBOL_HASH_SIZE 1024 157 158 struct symbol { 159 struct symbol *next; 160 struct module *module; 161 unsigned int crc; 162 int crc_valid; 163 unsigned int weak:1; 164 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */ 165 unsigned int kernel:1; /* 1 if symbol is from kernel 166 * (only for external modules) **/ 167 unsigned int preloaded:1; /* 1 if symbol from Module.symvers, or crc */ 168 enum export export; /* Type of export */ 169 char name[0]; 170 }; 171 172 static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 173 174 /* This is based on the hash agorithm from gdbm, via tdb */ 175 static inline unsigned int tdb_hash(const char *name) 176 { 177 unsigned value; /* Used to compute the hash value. */ 178 unsigned i; /* Used to cycle through random values. */ 179 180 /* Set the initial value from the key size. */ 181 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++) 182 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 183 184 return (1103515243 * value + 12345); 185 } 186 187 /** 188 * Allocate a new symbols for use in the hash of exported symbols or 189 * the list of unresolved symbols per module 190 **/ 191 static struct symbol *alloc_symbol(const char *name, unsigned int weak, 192 struct symbol *next) 193 { 194 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 195 196 memset(s, 0, sizeof(*s)); 197 strcpy(s->name, name); 198 s->weak = weak; 199 s->next = next; 200 return s; 201 } 202 203 /* For the hash of exported symbols */ 204 static struct symbol *new_symbol(const char *name, struct module *module, 205 enum export export) 206 { 207 unsigned int hash; 208 struct symbol *new; 209 210 hash = tdb_hash(name) % SYMBOL_HASH_SIZE; 211 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]); 212 new->module = module; 213 new->export = export; 214 return new; 215 } 216 217 static struct symbol *find_symbol(const char *name) 218 { 219 struct symbol *s; 220 221 /* For our purposes, .foo matches foo. PPC64 needs this. */ 222 if (name[0] == '.') 223 name++; 224 225 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) { 226 if (strcmp(s->name, name) == 0) 227 return s; 228 } 229 return NULL; 230 } 231 232 static const struct { 233 const char *str; 234 enum export export; 235 } export_list[] = { 236 { .str = "EXPORT_SYMBOL", .export = export_plain }, 237 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused }, 238 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl }, 239 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl }, 240 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future }, 241 { .str = "(unknown)", .export = export_unknown }, 242 }; 243 244 245 static const char *export_str(enum export ex) 246 { 247 return export_list[ex].str; 248 } 249 250 static enum export export_no(const char *s) 251 { 252 int i; 253 254 if (!s) 255 return export_unknown; 256 for (i = 0; export_list[i].export != export_unknown; i++) { 257 if (strcmp(export_list[i].str, s) == 0) 258 return export_list[i].export; 259 } 260 return export_unknown; 261 } 262 263 static const char *sec_name(struct elf_info *elf, int secindex); 264 265 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) 266 267 static enum export export_from_secname(struct elf_info *elf, unsigned int sec) 268 { 269 const char *secname = sec_name(elf, sec); 270 271 if (strstarts(secname, "___ksymtab+")) 272 return export_plain; 273 else if (strstarts(secname, "___ksymtab_unused+")) 274 return export_unused; 275 else if (strstarts(secname, "___ksymtab_gpl+")) 276 return export_gpl; 277 else if (strstarts(secname, "___ksymtab_unused_gpl+")) 278 return export_unused_gpl; 279 else if (strstarts(secname, "___ksymtab_gpl_future+")) 280 return export_gpl_future; 281 else 282 return export_unknown; 283 } 284 285 static enum export export_from_sec(struct elf_info *elf, unsigned int sec) 286 { 287 if (sec == elf->export_sec) 288 return export_plain; 289 else if (sec == elf->export_unused_sec) 290 return export_unused; 291 else if (sec == elf->export_gpl_sec) 292 return export_gpl; 293 else if (sec == elf->export_unused_gpl_sec) 294 return export_unused_gpl; 295 else if (sec == elf->export_gpl_future_sec) 296 return export_gpl_future; 297 else 298 return export_unknown; 299 } 300 301 /** 302 * Add an exported symbol - it may have already been added without a 303 * CRC, in this case just update the CRC 304 **/ 305 static struct symbol *sym_add_exported(const char *name, struct module *mod, 306 enum export export) 307 { 308 struct symbol *s = find_symbol(name); 309 310 if (!s) { 311 s = new_symbol(name, mod, export); 312 } else { 313 if (!s->preloaded) { 314 warn("%s: '%s' exported twice. Previous export " 315 "was in %s%s\n", mod->name, name, 316 s->module->name, 317 is_vmlinux(s->module->name) ?"":".ko"); 318 } else { 319 /* In case Module.symvers was out of date */ 320 s->module = mod; 321 } 322 } 323 s->preloaded = 0; 324 s->vmlinux = is_vmlinux(mod->name); 325 s->kernel = 0; 326 s->export = export; 327 return s; 328 } 329 330 static void sym_update_crc(const char *name, struct module *mod, 331 unsigned int crc, enum export export) 332 { 333 struct symbol *s = find_symbol(name); 334 335 if (!s) { 336 s = new_symbol(name, mod, export); 337 /* Don't complain when we find it later. */ 338 s->preloaded = 1; 339 } 340 s->crc = crc; 341 s->crc_valid = 1; 342 } 343 344 void *grab_file(const char *filename, unsigned long *size) 345 { 346 struct stat st; 347 void *map = MAP_FAILED; 348 int fd; 349 350 fd = open(filename, O_RDONLY); 351 if (fd < 0) 352 return NULL; 353 if (fstat(fd, &st)) 354 goto failed; 355 356 *size = st.st_size; 357 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 358 359 failed: 360 close(fd); 361 if (map == MAP_FAILED) 362 return NULL; 363 return map; 364 } 365 366 /** 367 * Return a copy of the next line in a mmap'ed file. 368 * spaces in the beginning of the line is trimmed away. 369 * Return a pointer to a static buffer. 370 **/ 371 char *get_next_line(unsigned long *pos, void *file, unsigned long size) 372 { 373 static char line[4096]; 374 int skip = 1; 375 size_t len = 0; 376 signed char *p = (signed char *)file + *pos; 377 char *s = line; 378 379 for (; *pos < size ; (*pos)++) { 380 if (skip && isspace(*p)) { 381 p++; 382 continue; 383 } 384 skip = 0; 385 if (*p != '\n' && (*pos < size)) { 386 len++; 387 *s++ = *p++; 388 if (len > 4095) 389 break; /* Too long, stop */ 390 } else { 391 /* End of string */ 392 *s = '\0'; 393 return line; 394 } 395 } 396 /* End of buffer */ 397 return NULL; 398 } 399 400 void release_file(void *file, unsigned long size) 401 { 402 munmap(file, size); 403 } 404 405 static int parse_elf(struct elf_info *info, const char *filename) 406 { 407 unsigned int i; 408 Elf_Ehdr *hdr; 409 Elf_Shdr *sechdrs; 410 Elf_Sym *sym; 411 const char *secstrings; 412 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; 413 414 hdr = grab_file(filename, &info->size); 415 if (!hdr) { 416 if (ignore_missing_files) { 417 fprintf(stderr, "%s: %s (ignored)\n", filename, 418 strerror(errno)); 419 return 0; 420 } 421 perror(filename); 422 exit(1); 423 } 424 info->hdr = hdr; 425 if (info->size < sizeof(*hdr)) { 426 /* file too small, assume this is an empty .o file */ 427 return 0; 428 } 429 /* Is this a valid ELF file? */ 430 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 431 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 432 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 433 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 434 /* Not an ELF file - silently ignore it */ 435 return 0; 436 } 437 /* Fix endianness in ELF header */ 438 hdr->e_type = TO_NATIVE(hdr->e_type); 439 hdr->e_machine = TO_NATIVE(hdr->e_machine); 440 hdr->e_version = TO_NATIVE(hdr->e_version); 441 hdr->e_entry = TO_NATIVE(hdr->e_entry); 442 hdr->e_phoff = TO_NATIVE(hdr->e_phoff); 443 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 444 hdr->e_flags = TO_NATIVE(hdr->e_flags); 445 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); 446 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); 447 hdr->e_phnum = TO_NATIVE(hdr->e_phnum); 448 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); 449 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 450 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 451 sechdrs = (void *)hdr + hdr->e_shoff; 452 info->sechdrs = sechdrs; 453 454 /* Check if file offset is correct */ 455 if (hdr->e_shoff > info->size) { 456 fatal("section header offset=%lu in file '%s' is bigger than " 457 "filesize=%lu\n", (unsigned long)hdr->e_shoff, 458 filename, info->size); 459 return 0; 460 } 461 462 if (hdr->e_shnum == SHN_UNDEF) { 463 /* 464 * There are more than 64k sections, 465 * read count from .sh_size. 466 */ 467 info->num_sections = TO_NATIVE(sechdrs[0].sh_size); 468 } 469 else { 470 info->num_sections = hdr->e_shnum; 471 } 472 if (hdr->e_shstrndx == SHN_XINDEX) { 473 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); 474 } 475 else { 476 info->secindex_strings = hdr->e_shstrndx; 477 } 478 479 /* Fix endianness in section headers */ 480 for (i = 0; i < info->num_sections; i++) { 481 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 482 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 483 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); 484 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 485 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 486 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 487 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 488 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 489 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); 490 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); 491 } 492 /* Find symbol table. */ 493 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; 494 for (i = 1; i < info->num_sections; i++) { 495 const char *secname; 496 int nobits = sechdrs[i].sh_type == SHT_NOBITS; 497 498 if (!nobits && sechdrs[i].sh_offset > info->size) { 499 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > " 500 "sizeof(*hrd)=%zu\n", filename, 501 (unsigned long)sechdrs[i].sh_offset, 502 sizeof(*hdr)); 503 return 0; 504 } 505 secname = secstrings + sechdrs[i].sh_name; 506 if (strcmp(secname, ".modinfo") == 0) { 507 if (nobits) 508 fatal("%s has NOBITS .modinfo\n", filename); 509 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 510 info->modinfo_len = sechdrs[i].sh_size; 511 } else if (strcmp(secname, "__ksymtab") == 0) 512 info->export_sec = i; 513 else if (strcmp(secname, "__ksymtab_unused") == 0) 514 info->export_unused_sec = i; 515 else if (strcmp(secname, "__ksymtab_gpl") == 0) 516 info->export_gpl_sec = i; 517 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0) 518 info->export_unused_gpl_sec = i; 519 else if (strcmp(secname, "__ksymtab_gpl_future") == 0) 520 info->export_gpl_future_sec = i; 521 522 if (sechdrs[i].sh_type == SHT_SYMTAB) { 523 unsigned int sh_link_idx; 524 symtab_idx = i; 525 info->symtab_start = (void *)hdr + 526 sechdrs[i].sh_offset; 527 info->symtab_stop = (void *)hdr + 528 sechdrs[i].sh_offset + sechdrs[i].sh_size; 529 sh_link_idx = sechdrs[i].sh_link; 530 info->strtab = (void *)hdr + 531 sechdrs[sh_link_idx].sh_offset; 532 } 533 534 /* 32bit section no. table? ("more than 64k sections") */ 535 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { 536 symtab_shndx_idx = i; 537 info->symtab_shndx_start = (void *)hdr + 538 sechdrs[i].sh_offset; 539 info->symtab_shndx_stop = (void *)hdr + 540 sechdrs[i].sh_offset + sechdrs[i].sh_size; 541 } 542 } 543 if (!info->symtab_start) 544 fatal("%s has no symtab?\n", filename); 545 546 /* Fix endianness in symbols */ 547 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 548 sym->st_shndx = TO_NATIVE(sym->st_shndx); 549 sym->st_name = TO_NATIVE(sym->st_name); 550 sym->st_value = TO_NATIVE(sym->st_value); 551 sym->st_size = TO_NATIVE(sym->st_size); 552 } 553 554 if (symtab_shndx_idx != ~0U) { 555 Elf32_Word *p; 556 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) 557 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", 558 filename, sechdrs[symtab_shndx_idx].sh_link, 559 symtab_idx); 560 /* Fix endianness */ 561 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; 562 p++) 563 *p = TO_NATIVE(*p); 564 } 565 566 return 1; 567 } 568 569 static void parse_elf_finish(struct elf_info *info) 570 { 571 release_file(info->hdr, info->size); 572 } 573 574 static int ignore_undef_symbol(struct elf_info *info, const char *symname) 575 { 576 /* ignore __this_module, it will be resolved shortly */ 577 if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0) 578 return 1; 579 /* ignore global offset table */ 580 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 581 return 1; 582 if (info->hdr->e_machine == EM_PPC) 583 /* Special register function linked on all modules during final link of .ko */ 584 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 || 585 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 || 586 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 || 587 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0 || 588 strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 || 589 strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0) 590 return 1; 591 if (info->hdr->e_machine == EM_PPC64) 592 /* Special register function linked on all modules during final link of .ko */ 593 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 || 594 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0 || 595 strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 || 596 strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0) 597 return 1; 598 /* Do not ignore this symbol */ 599 return 0; 600 } 601 602 #define CRC_PFX VMLINUX_SYMBOL_STR(__crc_) 603 #define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_) 604 605 static void handle_modversions(struct module *mod, struct elf_info *info, 606 Elf_Sym *sym, const char *symname) 607 { 608 unsigned int crc; 609 enum export export; 610 611 if ((!is_vmlinux(mod->name) || mod->is_dot_o) && 612 strncmp(symname, "__ksymtab", 9) == 0) 613 export = export_from_secname(info, get_secindex(info, sym)); 614 else 615 export = export_from_sec(info, get_secindex(info, sym)); 616 617 /* CRC'd symbol */ 618 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { 619 crc = (unsigned int) sym->st_value; 620 sym_update_crc(symname + strlen(CRC_PFX), mod, crc, 621 export); 622 } 623 624 switch (sym->st_shndx) { 625 case SHN_COMMON: 626 if (!strncmp(symname, "__gnu_lto_", sizeof("__gnu_lto_")-1)) { 627 /* Should warn here, but modpost runs before the linker */ 628 } else 629 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 630 break; 631 case SHN_UNDEF: 632 /* undefined symbol */ 633 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 634 ELF_ST_BIND(sym->st_info) != STB_WEAK) 635 break; 636 if (ignore_undef_symbol(info, symname)) 637 break; 638 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */ 639 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER) 640 /* add compatibility with older glibc */ 641 #ifndef STT_SPARC_REGISTER 642 #define STT_SPARC_REGISTER STT_REGISTER 643 #endif 644 if (info->hdr->e_machine == EM_SPARC || 645 info->hdr->e_machine == EM_SPARCV9) { 646 /* Ignore register directives. */ 647 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 648 break; 649 if (symname[0] == '.') { 650 char *munged = strdup(symname); 651 munged[0] = '_'; 652 munged[1] = toupper(munged[1]); 653 symname = munged; 654 } 655 } 656 #endif 657 658 #ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX 659 if (symname[0] != '_') 660 break; 661 else 662 symname++; 663 #endif 664 mod->unres = alloc_symbol(symname, 665 ELF_ST_BIND(sym->st_info) == STB_WEAK, 666 mod->unres); 667 break; 668 default: 669 /* All exported symbols */ 670 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) { 671 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod, 672 export); 673 } 674 if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0) 675 mod->has_init = 1; 676 if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0) 677 mod->has_cleanup = 1; 678 break; 679 } 680 } 681 682 /** 683 * Parse tag=value strings from .modinfo section 684 **/ 685 static char *next_string(char *string, unsigned long *secsize) 686 { 687 /* Skip non-zero chars */ 688 while (string[0]) { 689 string++; 690 if ((*secsize)-- <= 1) 691 return NULL; 692 } 693 694 /* Skip any zero padding. */ 695 while (!string[0]) { 696 string++; 697 if ((*secsize)-- <= 1) 698 return NULL; 699 } 700 return string; 701 } 702 703 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len, 704 const char *tag, char *info) 705 { 706 char *p; 707 unsigned int taglen = strlen(tag); 708 unsigned long size = modinfo_len; 709 710 if (info) { 711 size -= info - (char *)modinfo; 712 modinfo = next_string(info, &size); 713 } 714 715 for (p = modinfo; p; p = next_string(p, &size)) { 716 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 717 return p + taglen + 1; 718 } 719 return NULL; 720 } 721 722 static char *get_modinfo(void *modinfo, unsigned long modinfo_len, 723 const char *tag) 724 725 { 726 return get_next_modinfo(modinfo, modinfo_len, tag, NULL); 727 } 728 729 /** 730 * Test if string s ends in string sub 731 * return 0 if match 732 **/ 733 static int strrcmp(const char *s, const char *sub) 734 { 735 int slen, sublen; 736 737 if (!s || !sub) 738 return 1; 739 740 slen = strlen(s); 741 sublen = strlen(sub); 742 743 if ((slen == 0) || (sublen == 0)) 744 return 1; 745 746 if (sublen > slen) 747 return 1; 748 749 return memcmp(s + slen - sublen, sub, sublen); 750 } 751 752 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) 753 { 754 if (sym) 755 return elf->strtab + sym->st_name; 756 else 757 return "(unknown)"; 758 } 759 760 static const char *sec_name(struct elf_info *elf, int secindex) 761 { 762 Elf_Shdr *sechdrs = elf->sechdrs; 763 return (void *)elf->hdr + 764 elf->sechdrs[elf->secindex_strings].sh_offset + 765 sechdrs[secindex].sh_name; 766 } 767 768 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr) 769 { 770 return (void *)elf->hdr + 771 elf->sechdrs[elf->secindex_strings].sh_offset + 772 sechdr->sh_name; 773 } 774 775 /* The pattern is an array of simple patterns. 776 * "foo" will match an exact string equal to "foo" 777 * "*foo" will match a string that ends with "foo" 778 * "foo*" will match a string that begins with "foo" 779 */ 780 static int match(const char *sym, const char * const pat[]) 781 { 782 const char *p; 783 while (*pat) { 784 p = *pat++; 785 const char *endp = p + strlen(p) - 1; 786 787 /* "*foo" */ 788 if (*p == '*') { 789 if (strrcmp(sym, p + 1) == 0) 790 return 1; 791 } 792 /* "foo*" */ 793 else if (*endp == '*') { 794 if (strncmp(sym, p, strlen(p) - 1) == 0) 795 return 1; 796 } 797 /* no wildcards */ 798 else { 799 if (strcmp(p, sym) == 0) 800 return 1; 801 } 802 } 803 /* no match */ 804 return 0; 805 } 806 807 /* sections that we do not want to do full section mismatch check on */ 808 static const char *const section_white_list[] = 809 { 810 ".comment*", 811 ".debug*", 812 ".cranges", /* sh64 */ 813 ".zdebug*", /* Compressed debug sections. */ 814 ".GCC-command-line", /* mn10300 */ 815 ".GCC.command.line", /* record-gcc-switches, non mn10300 */ 816 ".mdebug*", /* alpha, score, mips etc. */ 817 ".pdr", /* alpha, score, mips etc. */ 818 ".stab*", 819 ".note*", 820 ".got*", 821 ".toc*", 822 ".xt.prop", /* xtensa */ 823 ".xt.lit", /* xtensa */ 824 ".arcextmap*", /* arc */ 825 ".gnu.linkonce.arcext*", /* arc : modules */ 826 ".gnu.lto*", 827 NULL 828 }; 829 830 /* 831 * This is used to find sections missing the SHF_ALLOC flag. 832 * The cause of this is often a section specified in assembler 833 * without "ax" / "aw". 834 */ 835 static void check_section(const char *modname, struct elf_info *elf, 836 Elf_Shdr *sechdr) 837 { 838 const char *sec = sech_name(elf, sechdr); 839 840 if (sechdr->sh_type == SHT_PROGBITS && 841 !(sechdr->sh_flags & SHF_ALLOC) && 842 !match(sec, section_white_list)) { 843 warn("%s (%s): unexpected non-allocatable section.\n" 844 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" 845 "Note that for example <linux/init.h> contains\n" 846 "section definitions for use in .S files.\n\n", 847 modname, sec); 848 } 849 } 850 851 852 853 #define ALL_INIT_DATA_SECTIONS \ 854 ".init.setup", ".init.rodata", ".meminit.rodata", \ 855 ".init.data", ".meminit.data" 856 #define ALL_EXIT_DATA_SECTIONS \ 857 ".exit.data", ".memexit.data" 858 859 #define ALL_INIT_TEXT_SECTIONS \ 860 ".init.text", ".meminit.text" 861 #define ALL_EXIT_TEXT_SECTIONS \ 862 ".exit.text", ".memexit.text" 863 864 #define ALL_PCI_INIT_SECTIONS \ 865 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ 866 ".pci_fixup_enable", ".pci_fixup_resume", \ 867 ".pci_fixup_resume_early", ".pci_fixup_suspend" 868 869 #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS 870 #define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS 871 872 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS 873 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS 874 875 #define DATA_SECTIONS ".data", ".data.rel" 876 #define TEXT_SECTIONS ".text", ".text.unlikely" 877 878 #define INIT_SECTIONS ".init.*" 879 #define MEM_INIT_SECTIONS ".meminit.*" 880 881 #define EXIT_SECTIONS ".exit.*" 882 #define MEM_EXIT_SECTIONS ".memexit.*" 883 884 /* init data sections */ 885 static const char *const init_data_sections[] = 886 { ALL_INIT_DATA_SECTIONS, NULL }; 887 888 /* all init sections */ 889 static const char *const init_sections[] = { ALL_INIT_SECTIONS, NULL }; 890 891 /* All init and exit sections (code + data) */ 892 static const char *const init_exit_sections[] = 893 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }; 894 895 /* data section */ 896 static const char *const data_sections[] = { DATA_SECTIONS, NULL }; 897 898 899 /* symbols in .data that may refer to init/exit sections */ 900 #define DEFAULT_SYMBOL_WHITE_LIST \ 901 "*driver", \ 902 "*_template", /* scsi uses *_template a lot */ \ 903 "*_timer", /* arm uses ops structures named _timer a lot */ \ 904 "*_sht", /* scsi also used *_sht to some extent */ \ 905 "*_ops", \ 906 "*_probe", \ 907 "*_probe_one", \ 908 "*_console" 909 910 static const char *const head_sections[] = { ".head.text*", NULL }; 911 static const char *const linker_symbols[] = 912 { "__init_begin", "_sinittext", "_einittext", NULL }; 913 914 enum mismatch { 915 TEXT_TO_ANY_INIT, 916 DATA_TO_ANY_INIT, 917 TEXT_TO_ANY_EXIT, 918 DATA_TO_ANY_EXIT, 919 XXXINIT_TO_SOME_INIT, 920 XXXEXIT_TO_SOME_EXIT, 921 ANY_INIT_TO_ANY_EXIT, 922 ANY_EXIT_TO_ANY_INIT, 923 EXPORT_TO_INIT_EXIT, 924 }; 925 926 struct sectioncheck { 927 const char *fromsec[20]; 928 const char *tosec[20]; 929 enum mismatch mismatch; 930 const char *symbol_white_list[20]; 931 }; 932 933 static const struct sectioncheck sectioncheck[] = { 934 /* Do not reference init/exit code/data from 935 * normal code and data 936 */ 937 { 938 .fromsec = { TEXT_SECTIONS, NULL }, 939 .tosec = { ALL_INIT_SECTIONS, NULL }, 940 .mismatch = TEXT_TO_ANY_INIT, 941 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 942 }, 943 { 944 .fromsec = { DATA_SECTIONS, NULL }, 945 .tosec = { ALL_XXXINIT_SECTIONS, NULL }, 946 .mismatch = DATA_TO_ANY_INIT, 947 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 948 }, 949 { 950 .fromsec = { DATA_SECTIONS, NULL }, 951 .tosec = { INIT_SECTIONS, NULL }, 952 .mismatch = DATA_TO_ANY_INIT, 953 .symbol_white_list = { 954 "*_template", "*_timer", "*_sht", "*_ops", 955 "*_probe", "*_probe_one", "*_console", NULL 956 }, 957 }, 958 { 959 .fromsec = { TEXT_SECTIONS, NULL }, 960 .tosec = { ALL_EXIT_SECTIONS, NULL }, 961 .mismatch = TEXT_TO_ANY_EXIT, 962 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 963 }, 964 { 965 .fromsec = { DATA_SECTIONS, NULL }, 966 .tosec = { ALL_EXIT_SECTIONS, NULL }, 967 .mismatch = DATA_TO_ANY_EXIT, 968 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 969 }, 970 /* Do not reference init code/data from meminit code/data */ 971 { 972 .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, 973 .tosec = { INIT_SECTIONS, NULL }, 974 .mismatch = XXXINIT_TO_SOME_INIT, 975 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 976 }, 977 /* Do not reference exit code/data from memexit code/data */ 978 { 979 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL }, 980 .tosec = { EXIT_SECTIONS, NULL }, 981 .mismatch = XXXEXIT_TO_SOME_EXIT, 982 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 983 }, 984 /* Do not use exit code/data from init code */ 985 { 986 .fromsec = { ALL_INIT_SECTIONS, NULL }, 987 .tosec = { ALL_EXIT_SECTIONS, NULL }, 988 .mismatch = ANY_INIT_TO_ANY_EXIT, 989 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 990 }, 991 /* Do not use init code/data from exit code */ 992 { 993 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 994 .tosec = { ALL_INIT_SECTIONS, NULL }, 995 .mismatch = ANY_EXIT_TO_ANY_INIT, 996 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 997 }, 998 { 999 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, 1000 .tosec = { INIT_SECTIONS, NULL }, 1001 .mismatch = ANY_INIT_TO_ANY_EXIT, 1002 .symbol_white_list = { NULL }, 1003 }, 1004 /* Do not export init/exit functions or data */ 1005 { 1006 .fromsec = { "__ksymtab*", NULL }, 1007 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL }, 1008 .mismatch = EXPORT_TO_INIT_EXIT, 1009 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, 1010 } 1011 }; 1012 1013 static const struct sectioncheck *section_mismatch( 1014 const char *fromsec, const char *tosec) 1015 { 1016 int i; 1017 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck); 1018 const struct sectioncheck *check = §ioncheck[0]; 1019 1020 for (i = 0; i < elems; i++) { 1021 if (match(fromsec, check->fromsec) && 1022 match(tosec, check->tosec)) 1023 return check; 1024 check++; 1025 } 1026 return NULL; 1027 } 1028 1029 /** 1030 * Whitelist to allow certain references to pass with no warning. 1031 * 1032 * Pattern 1: 1033 * If a module parameter is declared __initdata and permissions=0 1034 * then this is legal despite the warning generated. 1035 * We cannot see value of permissions here, so just ignore 1036 * this pattern. 1037 * The pattern is identified by: 1038 * tosec = .init.data 1039 * fromsec = .data* 1040 * atsym =__param* 1041 * 1042 * Pattern 1a: 1043 * module_param_call() ops can refer to __init set function if permissions=0 1044 * The pattern is identified by: 1045 * tosec = .init.text 1046 * fromsec = .data* 1047 * atsym = __param_ops_* 1048 * 1049 * Pattern 2: 1050 * Many drivers utilise a *driver container with references to 1051 * add, remove, probe functions etc. 1052 * the pattern is identified by: 1053 * tosec = init or exit section 1054 * fromsec = data section 1055 * atsym = *driver, *_template, *_sht, *_ops, *_probe, 1056 * *probe_one, *_console, *_timer 1057 * 1058 * Pattern 3: 1059 * Whitelist all references from .head.text to any init section 1060 * 1061 * Pattern 4: 1062 * Some symbols belong to init section but still it is ok to reference 1063 * these from non-init sections as these symbols don't have any memory 1064 * allocated for them and symbol address and value are same. So even 1065 * if init section is freed, its ok to reference those symbols. 1066 * For ex. symbols marking the init section boundaries. 1067 * This pattern is identified by 1068 * refsymname = __init_begin, _sinittext, _einittext 1069 * 1070 **/ 1071 static int secref_whitelist(const struct sectioncheck *mismatch, 1072 const char *fromsec, const char *fromsym, 1073 const char *tosec, const char *tosym) 1074 { 1075 /* Check for pattern 1 */ 1076 if (match(tosec, init_data_sections) && 1077 match(fromsec, data_sections) && 1078 (strncmp(fromsym, "__param", strlen("__param")) == 0)) 1079 return 0; 1080 1081 /* Check for pattern 1a */ 1082 if (strcmp(tosec, ".init.text") == 0 && 1083 match(fromsec, data_sections) && 1084 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0)) 1085 return 0; 1086 1087 /* Check for pattern 2 */ 1088 if (match(tosec, init_exit_sections) && 1089 match(fromsec, data_sections) && 1090 match(fromsym, mismatch->symbol_white_list)) 1091 return 0; 1092 1093 /* Check for pattern 3 */ 1094 if (match(fromsec, head_sections) && 1095 match(tosec, init_sections)) 1096 return 0; 1097 1098 /* Check for pattern 4 */ 1099 if (match(tosym, linker_symbols)) 1100 return 0; 1101 1102 return 1; 1103 } 1104 1105 /** 1106 * Find symbol based on relocation record info. 1107 * In some cases the symbol supplied is a valid symbol so 1108 * return refsym. If st_name != 0 we assume this is a valid symbol. 1109 * In other cases the symbol needs to be looked up in the symbol table 1110 * based on section and address. 1111 * **/ 1112 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr, 1113 Elf_Sym *relsym) 1114 { 1115 Elf_Sym *sym; 1116 Elf_Sym *near = NULL; 1117 Elf64_Sword distance = 20; 1118 Elf64_Sword d; 1119 unsigned int relsym_secindex; 1120 1121 if (relsym->st_name != 0) 1122 return relsym; 1123 1124 relsym_secindex = get_secindex(elf, relsym); 1125 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1126 if (get_secindex(elf, sym) != relsym_secindex) 1127 continue; 1128 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) 1129 continue; 1130 if (sym->st_value == addr) 1131 return sym; 1132 /* Find a symbol nearby - addr are maybe negative */ 1133 d = sym->st_value - addr; 1134 if (d < 0) 1135 d = addr - sym->st_value; 1136 if (d < distance) { 1137 distance = d; 1138 near = sym; 1139 } 1140 } 1141 /* We need a close match */ 1142 if (distance < 20) 1143 return near; 1144 else 1145 return NULL; 1146 } 1147 1148 static inline int is_arm_mapping_symbol(const char *str) 1149 { 1150 return str[0] == '$' && strchr("axtd", str[1]) 1151 && (str[2] == '\0' || str[2] == '.'); 1152 } 1153 1154 /* 1155 * If there's no name there, ignore it; likewise, ignore it if it's 1156 * one of the magic symbols emitted used by current ARM tools. 1157 * 1158 * Otherwise if find_symbols_between() returns those symbols, they'll 1159 * fail the whitelist tests and cause lots of false alarms ... fixable 1160 * only by merging __exit and __init sections into __text, bloating 1161 * the kernel (which is especially evil on embedded platforms). 1162 */ 1163 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 1164 { 1165 const char *name = elf->strtab + sym->st_name; 1166 1167 if (!name || !strlen(name)) 1168 return 0; 1169 return !is_arm_mapping_symbol(name); 1170 } 1171 1172 /* 1173 * Find symbols before or equal addr and after addr - in the section sec. 1174 * If we find two symbols with equal offset prefer one with a valid name. 1175 * The ELF format may have a better way to detect what type of symbol 1176 * it is, but this works for now. 1177 **/ 1178 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr, 1179 const char *sec) 1180 { 1181 Elf_Sym *sym; 1182 Elf_Sym *near = NULL; 1183 Elf_Addr distance = ~0; 1184 1185 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 1186 const char *symsec; 1187 1188 if (is_shndx_special(sym->st_shndx)) 1189 continue; 1190 symsec = sec_name(elf, get_secindex(elf, sym)); 1191 if (strcmp(symsec, sec) != 0) 1192 continue; 1193 if (!is_valid_name(elf, sym)) 1194 continue; 1195 if (sym->st_value <= addr) { 1196 if ((addr - sym->st_value) < distance) { 1197 distance = addr - sym->st_value; 1198 near = sym; 1199 } else if ((addr - sym->st_value) == distance) { 1200 near = sym; 1201 } 1202 } 1203 } 1204 return near; 1205 } 1206 1207 /* 1208 * Convert a section name to the function/data attribute 1209 * .init.text => __init 1210 * .memexitconst => __memconst 1211 * etc. 1212 * 1213 * The memory of returned value has been allocated on a heap. The user of this 1214 * method should free it after usage. 1215 */ 1216 static char *sec2annotation(const char *s) 1217 { 1218 if (match(s, init_exit_sections)) { 1219 char *p = malloc(20); 1220 char *r = p; 1221 1222 *p++ = '_'; 1223 *p++ = '_'; 1224 if (*s == '.') 1225 s++; 1226 while (*s && *s != '.') 1227 *p++ = *s++; 1228 *p = '\0'; 1229 if (*s == '.') 1230 s++; 1231 if (strstr(s, "rodata") != NULL) 1232 strcat(p, "const "); 1233 else if (strstr(s, "data") != NULL) 1234 strcat(p, "data "); 1235 else 1236 strcat(p, " "); 1237 return r; 1238 } else { 1239 return strdup(""); 1240 } 1241 } 1242 1243 static int is_function(Elf_Sym *sym) 1244 { 1245 if (sym) 1246 return ELF_ST_TYPE(sym->st_info) == STT_FUNC; 1247 else 1248 return -1; 1249 } 1250 1251 static void print_section_list(const char * const list[20]) 1252 { 1253 const char *const *s = list; 1254 1255 while (*s) { 1256 fprintf(stderr, "%s", *s); 1257 s++; 1258 if (*s) 1259 fprintf(stderr, ", "); 1260 } 1261 fprintf(stderr, "\n"); 1262 } 1263 1264 /* 1265 * Print a warning about a section mismatch. 1266 * Try to find symbols near it so user can find it. 1267 * Check whitelist before warning - it may be a false positive. 1268 */ 1269 static void report_sec_mismatch(const char *modname, 1270 const struct sectioncheck *mismatch, 1271 const char *fromsec, 1272 unsigned long long fromaddr, 1273 const char *fromsym, 1274 int from_is_func, 1275 const char *tosec, const char *tosym, 1276 int to_is_func) 1277 { 1278 const char *from, *from_p; 1279 const char *to, *to_p; 1280 char *prl_from; 1281 char *prl_to; 1282 1283 switch (from_is_func) { 1284 case 0: from = "variable"; from_p = ""; break; 1285 case 1: from = "function"; from_p = "()"; break; 1286 default: from = "(unknown reference)"; from_p = ""; break; 1287 } 1288 switch (to_is_func) { 1289 case 0: to = "variable"; to_p = ""; break; 1290 case 1: to = "function"; to_p = "()"; break; 1291 default: to = "(unknown reference)"; to_p = ""; break; 1292 } 1293 1294 sec_mismatch_count++; 1295 if (!sec_mismatch_verbose) 1296 return; 1297 1298 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s " 1299 "to the %s %s:%s%s\n", 1300 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec, 1301 tosym, to_p); 1302 1303 switch (mismatch->mismatch) { 1304 case TEXT_TO_ANY_INIT: 1305 prl_from = sec2annotation(fromsec); 1306 prl_to = sec2annotation(tosec); 1307 fprintf(stderr, 1308 "The function %s%s() references\n" 1309 "the %s %s%s%s.\n" 1310 "This is often because %s lacks a %s\n" 1311 "annotation or the annotation of %s is wrong.\n", 1312 prl_from, fromsym, 1313 to, prl_to, tosym, to_p, 1314 fromsym, prl_to, tosym); 1315 free(prl_from); 1316 free(prl_to); 1317 break; 1318 case DATA_TO_ANY_INIT: { 1319 prl_to = sec2annotation(tosec); 1320 fprintf(stderr, 1321 "The variable %s references\n" 1322 "the %s %s%s%s\n" 1323 "If the reference is valid then annotate the\n" 1324 "variable with __init* or __refdata (see linux/init.h) " 1325 "or name the variable:\n", 1326 fromsym, to, prl_to, tosym, to_p); 1327 print_section_list(mismatch->symbol_white_list); 1328 free(prl_to); 1329 break; 1330 } 1331 case TEXT_TO_ANY_EXIT: 1332 prl_to = sec2annotation(tosec); 1333 fprintf(stderr, 1334 "The function %s() references a %s in an exit section.\n" 1335 "Often the %s %s%s has valid usage outside the exit section\n" 1336 "and the fix is to remove the %sannotation of %s.\n", 1337 fromsym, to, to, tosym, to_p, prl_to, tosym); 1338 free(prl_to); 1339 break; 1340 case DATA_TO_ANY_EXIT: { 1341 prl_to = sec2annotation(tosec); 1342 fprintf(stderr, 1343 "The variable %s references\n" 1344 "the %s %s%s%s\n" 1345 "If the reference is valid then annotate the\n" 1346 "variable with __exit* (see linux/init.h) or " 1347 "name the variable:\n", 1348 fromsym, to, prl_to, tosym, to_p); 1349 print_section_list(mismatch->symbol_white_list); 1350 free(prl_to); 1351 break; 1352 } 1353 case XXXINIT_TO_SOME_INIT: 1354 case XXXEXIT_TO_SOME_EXIT: 1355 prl_from = sec2annotation(fromsec); 1356 prl_to = sec2annotation(tosec); 1357 fprintf(stderr, 1358 "The %s %s%s%s references\n" 1359 "a %s %s%s%s.\n" 1360 "If %s is only used by %s then\n" 1361 "annotate %s with a matching annotation.\n", 1362 from, prl_from, fromsym, from_p, 1363 to, prl_to, tosym, to_p, 1364 tosym, fromsym, tosym); 1365 free(prl_from); 1366 free(prl_to); 1367 break; 1368 case ANY_INIT_TO_ANY_EXIT: 1369 prl_from = sec2annotation(fromsec); 1370 prl_to = sec2annotation(tosec); 1371 fprintf(stderr, 1372 "The %s %s%s%s references\n" 1373 "a %s %s%s%s.\n" 1374 "This is often seen when error handling " 1375 "in the init function\n" 1376 "uses functionality in the exit path.\n" 1377 "The fix is often to remove the %sannotation of\n" 1378 "%s%s so it may be used outside an exit section.\n", 1379 from, prl_from, fromsym, from_p, 1380 to, prl_to, tosym, to_p, 1381 prl_to, tosym, to_p); 1382 free(prl_from); 1383 free(prl_to); 1384 break; 1385 case ANY_EXIT_TO_ANY_INIT: 1386 prl_from = sec2annotation(fromsec); 1387 prl_to = sec2annotation(tosec); 1388 fprintf(stderr, 1389 "The %s %s%s%s references\n" 1390 "a %s %s%s%s.\n" 1391 "This is often seen when error handling " 1392 "in the exit function\n" 1393 "uses functionality in the init path.\n" 1394 "The fix is often to remove the %sannotation of\n" 1395 "%s%s so it may be used outside an init section.\n", 1396 from, prl_from, fromsym, from_p, 1397 to, prl_to, tosym, to_p, 1398 prl_to, tosym, to_p); 1399 free(prl_from); 1400 free(prl_to); 1401 break; 1402 case EXPORT_TO_INIT_EXIT: 1403 prl_to = sec2annotation(tosec); 1404 fprintf(stderr, 1405 "The symbol %s is exported and annotated %s\n" 1406 "Fix this by removing the %sannotation of %s " 1407 "or drop the export.\n", 1408 tosym, prl_to, prl_to, tosym); 1409 free(prl_to); 1410 break; 1411 } 1412 fprintf(stderr, "\n"); 1413 } 1414 1415 static void check_section_mismatch(const char *modname, struct elf_info *elf, 1416 Elf_Rela *r, Elf_Sym *sym, const char *fromsec) 1417 { 1418 const char *tosec; 1419 const struct sectioncheck *mismatch; 1420 1421 tosec = sec_name(elf, get_secindex(elf, sym)); 1422 mismatch = section_mismatch(fromsec, tosec); 1423 if (mismatch) { 1424 Elf_Sym *to; 1425 Elf_Sym *from; 1426 const char *tosym; 1427 const char *fromsym; 1428 1429 from = find_elf_symbol2(elf, r->r_offset, fromsec); 1430 fromsym = sym_name(elf, from); 1431 to = find_elf_symbol(elf, r->r_addend, sym); 1432 tosym = sym_name(elf, to); 1433 1434 if (!strncmp(fromsym, "reference___initcall", 1435 sizeof("reference___initcall")-1)) 1436 return; 1437 1438 /* check whitelist - we may ignore it */ 1439 if (secref_whitelist(mismatch, 1440 fromsec, fromsym, tosec, tosym)) { 1441 report_sec_mismatch(modname, mismatch, 1442 fromsec, r->r_offset, fromsym, 1443 is_function(from), tosec, tosym, 1444 is_function(to)); 1445 } 1446 } 1447 } 1448 1449 static unsigned int *reloc_location(struct elf_info *elf, 1450 Elf_Shdr *sechdr, Elf_Rela *r) 1451 { 1452 Elf_Shdr *sechdrs = elf->sechdrs; 1453 int section = sechdr->sh_info; 1454 1455 return (void *)elf->hdr + sechdrs[section].sh_offset + 1456 r->r_offset; 1457 } 1458 1459 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1460 { 1461 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1462 unsigned int *location = reloc_location(elf, sechdr, r); 1463 1464 switch (r_typ) { 1465 case R_386_32: 1466 r->r_addend = TO_NATIVE(*location); 1467 break; 1468 case R_386_PC32: 1469 r->r_addend = TO_NATIVE(*location) + 4; 1470 /* For CONFIG_RELOCATABLE=y */ 1471 if (elf->hdr->e_type == ET_EXEC) 1472 r->r_addend += r->r_offset; 1473 break; 1474 } 1475 return 0; 1476 } 1477 1478 #ifndef R_ARM_CALL 1479 #define R_ARM_CALL 28 1480 #endif 1481 #ifndef R_ARM_JUMP24 1482 #define R_ARM_JUMP24 29 1483 #endif 1484 1485 #ifndef R_ARM_THM_CALL 1486 #define R_ARM_THM_CALL 10 1487 #endif 1488 #ifndef R_ARM_THM_JUMP24 1489 #define R_ARM_THM_JUMP24 30 1490 #endif 1491 #ifndef R_ARM_THM_JUMP19 1492 #define R_ARM_THM_JUMP19 51 1493 #endif 1494 1495 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1496 { 1497 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1498 1499 switch (r_typ) { 1500 case R_ARM_ABS32: 1501 /* From ARM ABI: (S + A) | T */ 1502 r->r_addend = (int)(long) 1503 (elf->symtab_start + ELF_R_SYM(r->r_info)); 1504 break; 1505 case R_ARM_PC24: 1506 case R_ARM_CALL: 1507 case R_ARM_JUMP24: 1508 case R_ARM_THM_CALL: 1509 case R_ARM_THM_JUMP24: 1510 case R_ARM_THM_JUMP19: 1511 /* From ARM ABI: ((S + A) | T) - P */ 1512 r->r_addend = (int)(long)(elf->hdr + 1513 sechdr->sh_offset + 1514 (r->r_offset - sechdr->sh_addr)); 1515 break; 1516 default: 1517 return 1; 1518 } 1519 return 0; 1520 } 1521 1522 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) 1523 { 1524 unsigned int r_typ = ELF_R_TYPE(r->r_info); 1525 unsigned int *location = reloc_location(elf, sechdr, r); 1526 unsigned int inst; 1527 1528 if (r_typ == R_MIPS_HI16) 1529 return 1; /* skip this */ 1530 inst = TO_NATIVE(*location); 1531 switch (r_typ) { 1532 case R_MIPS_LO16: 1533 r->r_addend = inst & 0xffff; 1534 break; 1535 case R_MIPS_26: 1536 r->r_addend = (inst & 0x03ffffff) << 2; 1537 break; 1538 case R_MIPS_32: 1539 r->r_addend = inst; 1540 break; 1541 } 1542 return 0; 1543 } 1544 1545 static void section_rela(const char *modname, struct elf_info *elf, 1546 Elf_Shdr *sechdr) 1547 { 1548 Elf_Sym *sym; 1549 Elf_Rela *rela; 1550 Elf_Rela r; 1551 unsigned int r_sym; 1552 const char *fromsec; 1553 1554 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; 1555 Elf_Rela *stop = (void *)start + sechdr->sh_size; 1556 1557 fromsec = sech_name(elf, sechdr); 1558 fromsec += strlen(".rela"); 1559 /* if from section (name) is know good then skip it */ 1560 if (match(fromsec, section_white_list)) 1561 return; 1562 1563 for (rela = start; rela < stop; rela++) { 1564 r.r_offset = TO_NATIVE(rela->r_offset); 1565 #if KERNEL_ELFCLASS == ELFCLASS64 1566 if (elf->hdr->e_machine == EM_MIPS) { 1567 unsigned int r_typ; 1568 r_sym = ELF64_MIPS_R_SYM(rela->r_info); 1569 r_sym = TO_NATIVE(r_sym); 1570 r_typ = ELF64_MIPS_R_TYPE(rela->r_info); 1571 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1572 } else { 1573 r.r_info = TO_NATIVE(rela->r_info); 1574 r_sym = ELF_R_SYM(r.r_info); 1575 } 1576 #else 1577 r.r_info = TO_NATIVE(rela->r_info); 1578 r_sym = ELF_R_SYM(r.r_info); 1579 #endif 1580 r.r_addend = TO_NATIVE(rela->r_addend); 1581 sym = elf->symtab_start + r_sym; 1582 /* Skip special sections */ 1583 if (is_shndx_special(sym->st_shndx)) 1584 continue; 1585 check_section_mismatch(modname, elf, &r, sym, fromsec); 1586 } 1587 } 1588 1589 static void section_rel(const char *modname, struct elf_info *elf, 1590 Elf_Shdr *sechdr) 1591 { 1592 Elf_Sym *sym; 1593 Elf_Rel *rel; 1594 Elf_Rela r; 1595 unsigned int r_sym; 1596 const char *fromsec; 1597 1598 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset; 1599 Elf_Rel *stop = (void *)start + sechdr->sh_size; 1600 1601 fromsec = sech_name(elf, sechdr); 1602 fromsec += strlen(".rel"); 1603 /* if from section (name) is know good then skip it */ 1604 if (match(fromsec, section_white_list)) 1605 return; 1606 1607 for (rel = start; rel < stop; rel++) { 1608 r.r_offset = TO_NATIVE(rel->r_offset); 1609 #if KERNEL_ELFCLASS == ELFCLASS64 1610 if (elf->hdr->e_machine == EM_MIPS) { 1611 unsigned int r_typ; 1612 r_sym = ELF64_MIPS_R_SYM(rel->r_info); 1613 r_sym = TO_NATIVE(r_sym); 1614 r_typ = ELF64_MIPS_R_TYPE(rel->r_info); 1615 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1616 } else { 1617 r.r_info = TO_NATIVE(rel->r_info); 1618 r_sym = ELF_R_SYM(r.r_info); 1619 } 1620 #else 1621 r.r_info = TO_NATIVE(rel->r_info); 1622 r_sym = ELF_R_SYM(r.r_info); 1623 #endif 1624 r.r_addend = 0; 1625 switch (elf->hdr->e_machine) { 1626 case EM_386: 1627 if (addend_386_rel(elf, sechdr, &r)) 1628 continue; 1629 break; 1630 case EM_ARM: 1631 if (addend_arm_rel(elf, sechdr, &r)) 1632 continue; 1633 break; 1634 case EM_MIPS: 1635 if (addend_mips_rel(elf, sechdr, &r)) 1636 continue; 1637 break; 1638 } 1639 sym = elf->symtab_start + r_sym; 1640 /* Skip special sections */ 1641 if (is_shndx_special(sym->st_shndx)) 1642 continue; 1643 check_section_mismatch(modname, elf, &r, sym, fromsec); 1644 } 1645 } 1646 1647 /** 1648 * A module includes a number of sections that are discarded 1649 * either when loaded or when used as built-in. 1650 * For loaded modules all functions marked __init and all data 1651 * marked __initdata will be discarded when the module has been initialized. 1652 * Likewise for modules used built-in the sections marked __exit 1653 * are discarded because __exit marked function are supposed to be called 1654 * only when a module is unloaded which never happens for built-in modules. 1655 * The check_sec_ref() function traverses all relocation records 1656 * to find all references to a section that reference a section that will 1657 * be discarded and warns about it. 1658 **/ 1659 static void check_sec_ref(struct module *mod, const char *modname, 1660 struct elf_info *elf) 1661 { 1662 int i; 1663 Elf_Shdr *sechdrs = elf->sechdrs; 1664 1665 /* Walk through all sections */ 1666 for (i = 0; i < elf->num_sections; i++) { 1667 check_section(modname, elf, &elf->sechdrs[i]); 1668 /* We want to process only relocation sections and not .init */ 1669 if (sechdrs[i].sh_type == SHT_RELA) 1670 section_rela(modname, elf, &elf->sechdrs[i]); 1671 else if (sechdrs[i].sh_type == SHT_REL) 1672 section_rel(modname, elf, &elf->sechdrs[i]); 1673 } 1674 } 1675 1676 static char *remove_dot(char *s) 1677 { 1678 size_t n = strcspn(s, "."); 1679 1680 if (n && s[n]) { 1681 size_t m = strspn(s + n + 1, "0123456789"); 1682 if (m && (s[n + m] == '.' || s[n + m] == 0)) 1683 s[n] = 0; 1684 } 1685 return s; 1686 } 1687 1688 static void read_symbols(char *modname) 1689 { 1690 const char *symname; 1691 char *version; 1692 char *license; 1693 struct module *mod; 1694 struct elf_info info = { }; 1695 Elf_Sym *sym; 1696 1697 if (!parse_elf(&info, modname)) 1698 return; 1699 1700 mod = new_module(modname); 1701 1702 /* When there's no vmlinux, don't print warnings about 1703 * unresolved symbols (since there'll be too many ;) */ 1704 if (is_vmlinux(modname)) { 1705 have_vmlinux = 1; 1706 mod->skip = 1; 1707 } 1708 1709 license = get_modinfo(info.modinfo, info.modinfo_len, "license"); 1710 if (info.modinfo && !license && !is_vmlinux(modname)) 1711 warn("modpost: missing MODULE_LICENSE() in %s\n" 1712 "see include/linux/module.h for " 1713 "more information\n", modname); 1714 while (license) { 1715 if (license_is_gpl_compatible(license)) 1716 mod->gpl_compatible = 1; 1717 else { 1718 mod->gpl_compatible = 0; 1719 break; 1720 } 1721 license = get_next_modinfo(info.modinfo, info.modinfo_len, 1722 "license", license); 1723 } 1724 1725 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1726 symname = remove_dot(info.strtab + sym->st_name); 1727 1728 handle_modversions(mod, &info, sym, symname); 1729 handle_moddevtable(mod, &info, sym, symname); 1730 } 1731 if (!is_vmlinux(modname) || 1732 (is_vmlinux(modname) && vmlinux_section_warnings)) 1733 check_sec_ref(mod, modname, &info); 1734 1735 version = get_modinfo(info.modinfo, info.modinfo_len, "version"); 1736 if (version) 1737 maybe_frob_rcs_version(modname, version, info.modinfo, 1738 version - (char *)info.hdr); 1739 if (version || (all_versions && !is_vmlinux(modname))) 1740 get_src_version(modname, mod->srcversion, 1741 sizeof(mod->srcversion)-1); 1742 1743 parse_elf_finish(&info); 1744 1745 /* Our trick to get versioning for module struct etc. - it's 1746 * never passed as an argument to an exported function, so 1747 * the automatic versioning doesn't pick it up, but it's really 1748 * important anyhow */ 1749 if (modversions) 1750 mod->unres = alloc_symbol("module_layout", 0, mod->unres); 1751 } 1752 1753 static void read_symbols_from_files(const char *filename) 1754 { 1755 FILE *in = stdin; 1756 char fname[PATH_MAX]; 1757 1758 if (strcmp(filename, "-") != 0) { 1759 in = fopen(filename, "r"); 1760 if (!in) 1761 fatal("Can't open filenames file %s: %m", filename); 1762 } 1763 1764 while (fgets(fname, PATH_MAX, in) != NULL) { 1765 if (strends(fname, "\n")) 1766 fname[strlen(fname)-1] = '\0'; 1767 read_symbols(fname); 1768 } 1769 1770 if (in != stdin) 1771 fclose(in); 1772 } 1773 1774 #define SZ 500 1775 1776 /* We first write the generated file into memory using the 1777 * following helper, then compare to the file on disk and 1778 * only update the later if anything changed */ 1779 1780 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1781 const char *fmt, ...) 1782 { 1783 char tmp[SZ]; 1784 int len; 1785 va_list ap; 1786 1787 va_start(ap, fmt); 1788 len = vsnprintf(tmp, SZ, fmt, ap); 1789 buf_write(buf, tmp, len); 1790 va_end(ap); 1791 } 1792 1793 void buf_write(struct buffer *buf, const char *s, int len) 1794 { 1795 if (buf->size - buf->pos < len) { 1796 buf->size += len + SZ; 1797 buf->p = realloc(buf->p, buf->size); 1798 } 1799 strncpy(buf->p + buf->pos, s, len); 1800 buf->pos += len; 1801 } 1802 1803 static void check_for_gpl_usage(enum export exp, const char *m, const char *s) 1804 { 1805 const char *e = is_vmlinux(m) ?"":".ko"; 1806 1807 switch (exp) { 1808 case export_gpl: 1809 fatal("modpost: GPL-incompatible module %s%s " 1810 "uses GPL-only symbol '%s'\n", m, e, s); 1811 break; 1812 case export_unused_gpl: 1813 fatal("modpost: GPL-incompatible module %s%s " 1814 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); 1815 break; 1816 case export_gpl_future: 1817 warn("modpost: GPL-incompatible module %s%s " 1818 "uses future GPL-only symbol '%s'\n", m, e, s); 1819 break; 1820 case export_plain: 1821 case export_unused: 1822 case export_unknown: 1823 /* ignore */ 1824 break; 1825 } 1826 } 1827 1828 static void check_for_unused(enum export exp, const char *m, const char *s) 1829 { 1830 const char *e = is_vmlinux(m) ?"":".ko"; 1831 1832 switch (exp) { 1833 case export_unused: 1834 case export_unused_gpl: 1835 warn("modpost: module %s%s " 1836 "uses symbol '%s' marked UNUSED\n", m, e, s); 1837 break; 1838 default: 1839 /* ignore */ 1840 break; 1841 } 1842 } 1843 1844 static void check_exports(struct module *mod) 1845 { 1846 struct symbol *s, *exp; 1847 1848 for (s = mod->unres; s; s = s->next) { 1849 const char *basename; 1850 exp = find_symbol(s->name); 1851 if (!exp || exp->module == mod) 1852 continue; 1853 basename = strrchr(mod->name, '/'); 1854 if (basename) 1855 basename++; 1856 else 1857 basename = mod->name; 1858 if (!mod->gpl_compatible) 1859 check_for_gpl_usage(exp->export, basename, exp->name); 1860 check_for_unused(exp->export, basename, exp->name); 1861 } 1862 } 1863 1864 /** 1865 * Header for the generated file 1866 **/ 1867 static void add_header(struct buffer *b, struct module *mod) 1868 { 1869 buf_printf(b, "#include <linux/module.h>\n"); 1870 buf_printf(b, "#include <linux/vermagic.h>\n"); 1871 buf_printf(b, "#include <linux/compiler.h>\n"); 1872 buf_printf(b, "\n"); 1873 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1874 buf_printf(b, "\n"); 1875 buf_printf(b, "__visible struct module __this_module\n"); 1876 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); 1877 buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); 1878 if (mod->has_init) 1879 buf_printf(b, "\t.init = init_module,\n"); 1880 if (mod->has_cleanup) 1881 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1882 "\t.exit = cleanup_module,\n" 1883 "#endif\n"); 1884 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); 1885 buf_printf(b, "};\n"); 1886 } 1887 1888 static void add_intree_flag(struct buffer *b, int is_intree) 1889 { 1890 if (is_intree) 1891 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); 1892 } 1893 1894 static void add_staging_flag(struct buffer *b, const char *name) 1895 { 1896 static const char *staging_dir = "drivers/staging"; 1897 1898 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0) 1899 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); 1900 } 1901 1902 /** 1903 * Record CRCs for unresolved symbols 1904 **/ 1905 static int add_versions(struct buffer *b, struct module *mod) 1906 { 1907 struct symbol *s, *exp; 1908 int err = 0; 1909 1910 for (s = mod->unres; s; s = s->next) { 1911 exp = find_symbol(s->name); 1912 if (!exp || exp->module == mod) { 1913 if (have_vmlinux && !s->weak) { 1914 if (warn_unresolved) { 1915 warn("\"%s\" [%s.ko] undefined!\n", 1916 s->name, mod->name); 1917 } else { 1918 merror("\"%s\" [%s.ko] undefined!\n", 1919 s->name, mod->name); 1920 err = 1; 1921 } 1922 } 1923 continue; 1924 } 1925 s->module = exp->module; 1926 s->crc_valid = exp->crc_valid; 1927 s->crc = exp->crc; 1928 } 1929 1930 if (!modversions) 1931 return err; 1932 1933 buf_printf(b, "\n"); 1934 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1935 buf_printf(b, "__used\n"); 1936 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); 1937 1938 for (s = mod->unres; s; s = s->next) { 1939 if (!s->module) 1940 continue; 1941 if (!s->crc_valid) { 1942 warn("\"%s\" [%s.ko] has no CRC!\n", 1943 s->name, mod->name); 1944 continue; 1945 } 1946 buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n", 1947 s->crc, s->name); 1948 } 1949 1950 buf_printf(b, "};\n"); 1951 1952 return err; 1953 } 1954 1955 static void add_depends(struct buffer *b, struct module *mod, 1956 struct module *modules) 1957 { 1958 struct symbol *s; 1959 struct module *m; 1960 int first = 1; 1961 1962 for (m = modules; m; m = m->next) 1963 m->seen = is_vmlinux(m->name); 1964 1965 buf_printf(b, "\n"); 1966 buf_printf(b, "static const char __module_depends[]\n"); 1967 buf_printf(b, "__used\n"); 1968 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); 1969 buf_printf(b, "\"depends="); 1970 for (s = mod->unres; s; s = s->next) { 1971 const char *p; 1972 if (!s->module) 1973 continue; 1974 1975 if (s->module->seen) 1976 continue; 1977 1978 s->module->seen = 1; 1979 p = strrchr(s->module->name, '/'); 1980 if (p) 1981 p++; 1982 else 1983 p = s->module->name; 1984 buf_printf(b, "%s%s", first ? "" : ",", p); 1985 first = 0; 1986 } 1987 buf_printf(b, "\";\n"); 1988 } 1989 1990 static void add_srcversion(struct buffer *b, struct module *mod) 1991 { 1992 if (mod->srcversion[0]) { 1993 buf_printf(b, "\n"); 1994 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1995 mod->srcversion); 1996 } 1997 } 1998 1999 static void write_if_changed(struct buffer *b, const char *fname) 2000 { 2001 char *tmp; 2002 FILE *file; 2003 struct stat st; 2004 2005 file = fopen(fname, "r"); 2006 if (!file) 2007 goto write; 2008 2009 if (fstat(fileno(file), &st) < 0) 2010 goto close_write; 2011 2012 if (st.st_size != b->pos) 2013 goto close_write; 2014 2015 tmp = NOFAIL(malloc(b->pos)); 2016 if (fread(tmp, 1, b->pos, file) != b->pos) 2017 goto free_write; 2018 2019 if (memcmp(tmp, b->p, b->pos) != 0) 2020 goto free_write; 2021 2022 free(tmp); 2023 fclose(file); 2024 return; 2025 2026 free_write: 2027 free(tmp); 2028 close_write: 2029 fclose(file); 2030 write: 2031 file = fopen(fname, "w"); 2032 if (!file) { 2033 perror(fname); 2034 exit(1); 2035 } 2036 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 2037 perror(fname); 2038 exit(1); 2039 } 2040 fclose(file); 2041 } 2042 2043 /* parse Module.symvers file. line format: 2044 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] 2045 **/ 2046 static void read_dump(const char *fname, unsigned int kernel) 2047 { 2048 unsigned long size, pos = 0; 2049 void *file = grab_file(fname, &size); 2050 char *line; 2051 2052 if (!file) 2053 /* No symbol versions, silently ignore */ 2054 return; 2055 2056 while ((line = get_next_line(&pos, file, size))) { 2057 char *symname, *modname, *d, *export, *end; 2058 unsigned int crc; 2059 struct module *mod; 2060 struct symbol *s; 2061 2062 if (!(symname = strchr(line, '\t'))) 2063 goto fail; 2064 *symname++ = '\0'; 2065 if (!(modname = strchr(symname, '\t'))) 2066 goto fail; 2067 *modname++ = '\0'; 2068 if ((export = strchr(modname, '\t')) != NULL) 2069 *export++ = '\0'; 2070 if (export && ((end = strchr(export, '\t')) != NULL)) 2071 *end = '\0'; 2072 crc = strtoul(line, &d, 16); 2073 if (*symname == '\0' || *modname == '\0' || *d != '\0') 2074 goto fail; 2075 mod = find_module(modname); 2076 if (!mod) { 2077 if (is_vmlinux(modname)) 2078 have_vmlinux = 1; 2079 mod = new_module(modname); 2080 mod->skip = 1; 2081 } 2082 s = sym_add_exported(symname, mod, export_no(export)); 2083 s->kernel = kernel; 2084 s->preloaded = 1; 2085 sym_update_crc(symname, mod, crc, export_no(export)); 2086 } 2087 release_file(file, size); 2088 return; 2089 fail: 2090 release_file(file, size); 2091 fatal("parse error in symbol dump file\n"); 2092 } 2093 2094 /* For normal builds always dump all symbols. 2095 * For external modules only dump symbols 2096 * that are not read from kernel Module.symvers. 2097 **/ 2098 static int dump_sym(struct symbol *sym) 2099 { 2100 if (!external_module) 2101 return 1; 2102 if (sym->vmlinux || sym->kernel) 2103 return 0; 2104 return 1; 2105 } 2106 2107 static void write_dump(const char *fname) 2108 { 2109 struct buffer buf = { }; 2110 struct symbol *symbol; 2111 int n; 2112 2113 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { 2114 symbol = symbolhash[n]; 2115 while (symbol) { 2116 if (dump_sym(symbol)) 2117 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", 2118 symbol->crc, symbol->name, 2119 symbol->module->name, 2120 export_str(symbol->export)); 2121 symbol = symbol->next; 2122 } 2123 } 2124 write_if_changed(&buf, fname); 2125 } 2126 2127 struct ext_sym_list { 2128 struct ext_sym_list *next; 2129 const char *file; 2130 }; 2131 2132 int main(int argc, char **argv) 2133 { 2134 struct module *mod; 2135 struct buffer buf = { }; 2136 char *kernel_read = NULL, *module_read = NULL; 2137 char *dump_write = NULL, *files_source = NULL; 2138 int opt; 2139 int err; 2140 struct ext_sym_list *extsym_iter; 2141 struct ext_sym_list *extsym_start = NULL; 2142 2143 while ((opt = getopt(argc, argv, "i:I:e:mnsST:o:awM:K:")) != -1) { 2144 switch (opt) { 2145 case 'i': 2146 kernel_read = optarg; 2147 break; 2148 case 'I': 2149 module_read = optarg; 2150 external_module = 1; 2151 break; 2152 case 'e': 2153 external_module = 1; 2154 extsym_iter = 2155 NOFAIL(malloc(sizeof(*extsym_iter))); 2156 extsym_iter->next = extsym_start; 2157 extsym_iter->file = optarg; 2158 extsym_start = extsym_iter; 2159 break; 2160 case 'm': 2161 modversions = 1; 2162 break; 2163 case 'n': 2164 ignore_missing_files = 1; 2165 break; 2166 case 'o': 2167 dump_write = optarg; 2168 break; 2169 case 'a': 2170 all_versions = 1; 2171 break; 2172 case 's': 2173 vmlinux_section_warnings = 0; 2174 break; 2175 case 'S': 2176 sec_mismatch_verbose = 0; 2177 break; 2178 case 'T': 2179 files_source = optarg; 2180 break; 2181 case 'w': 2182 warn_unresolved = 1; 2183 break; 2184 default: 2185 exit(1); 2186 } 2187 } 2188 2189 if (kernel_read) 2190 read_dump(kernel_read, 1); 2191 if (module_read) 2192 read_dump(module_read, 0); 2193 while (extsym_start) { 2194 read_dump(extsym_start->file, 0); 2195 extsym_iter = extsym_start->next; 2196 free(extsym_start); 2197 extsym_start = extsym_iter; 2198 } 2199 2200 while (optind < argc) 2201 read_symbols(argv[optind++]); 2202 2203 if (files_source) 2204 read_symbols_from_files(files_source); 2205 2206 for (mod = modules; mod; mod = mod->next) { 2207 if (mod->skip) 2208 continue; 2209 check_exports(mod); 2210 } 2211 2212 err = 0; 2213 2214 for (mod = modules; mod; mod = mod->next) { 2215 char fname[PATH_MAX]; 2216 2217 if (mod->skip) 2218 continue; 2219 2220 buf.pos = 0; 2221 2222 add_header(&buf, mod); 2223 add_intree_flag(&buf, !external_module); 2224 add_staging_flag(&buf, mod->name); 2225 err |= add_versions(&buf, mod); 2226 add_depends(&buf, mod, modules); 2227 add_moddevtable(&buf, mod); 2228 add_srcversion(&buf, mod); 2229 2230 sprintf(fname, "%s.mod.c", mod->name); 2231 write_if_changed(&buf, fname); 2232 } 2233 2234 if (dump_write) 2235 write_dump(dump_write); 2236 if (sec_mismatch_count && !sec_mismatch_verbose) 2237 warn("modpost: Found %d section mismatch(es).\n" 2238 "To see full details build your kernel with:\n" 2239 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n", 2240 sec_mismatch_count); 2241 2242 return err; 2243 } 2244