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