1 /* Postprocess module symbol versions 2 * 3 * Copyright 2003 Kai Germaschewski 4 * Copyright 2002-2004 Rusty Russell, IBM Corporation 5 * Copyright 2006 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 #include <ctype.h> 15 #include "modpost.h" 16 #include "../../include/linux/license.h" 17 18 /* Are we using CONFIG_MODVERSIONS? */ 19 int modversions = 0; 20 /* Warn about undefined symbols? (do so if we have vmlinux) */ 21 int have_vmlinux = 0; 22 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ 23 static int all_versions = 0; 24 /* If we are modposting external module set to 1 */ 25 static int external_module = 0; 26 /* Warn about section mismatch in vmlinux if set to 1 */ 27 static int vmlinux_section_warnings = 1; 28 /* Only warn about unresolved symbols */ 29 static int warn_unresolved = 0; 30 /* How a symbol is exported */ 31 enum export { 32 export_plain, export_unused, export_gpl, 33 export_unused_gpl, export_gpl_future, export_unknown 34 }; 35 36 void fatal(const char *fmt, ...) 37 { 38 va_list arglist; 39 40 fprintf(stderr, "FATAL: "); 41 42 va_start(arglist, fmt); 43 vfprintf(stderr, fmt, arglist); 44 va_end(arglist); 45 46 exit(1); 47 } 48 49 void warn(const char *fmt, ...) 50 { 51 va_list arglist; 52 53 fprintf(stderr, "WARNING: "); 54 55 va_start(arglist, fmt); 56 vfprintf(stderr, fmt, arglist); 57 va_end(arglist); 58 } 59 60 void merror(const char *fmt, ...) 61 { 62 va_list arglist; 63 64 fprintf(stderr, "ERROR: "); 65 66 va_start(arglist, fmt); 67 vfprintf(stderr, fmt, arglist); 68 va_end(arglist); 69 } 70 71 static int is_vmlinux(const char *modname) 72 { 73 const char *myname; 74 75 if ((myname = strrchr(modname, '/'))) 76 myname++; 77 else 78 myname = modname; 79 80 return (strcmp(myname, "vmlinux") == 0) || 81 (strcmp(myname, "vmlinux.o") == 0); 82 } 83 84 void *do_nofail(void *ptr, const char *expr) 85 { 86 if (!ptr) { 87 fatal("modpost: Memory allocation failure: %s.\n", expr); 88 } 89 return ptr; 90 } 91 92 /* A list of all modules we processed */ 93 94 static struct module *modules; 95 96 static struct module *find_module(char *modname) 97 { 98 struct module *mod; 99 100 for (mod = modules; mod; mod = mod->next) 101 if (strcmp(mod->name, modname) == 0) 102 break; 103 return mod; 104 } 105 106 static struct module *new_module(char *modname) 107 { 108 struct module *mod; 109 char *p, *s; 110 111 mod = NOFAIL(malloc(sizeof(*mod))); 112 memset(mod, 0, sizeof(*mod)); 113 p = NOFAIL(strdup(modname)); 114 115 /* strip trailing .o */ 116 if ((s = strrchr(p, '.')) != NULL) 117 if (strcmp(s, ".o") == 0) 118 *s = '\0'; 119 120 /* add to list */ 121 mod->name = p; 122 mod->gpl_compatible = -1; 123 mod->next = modules; 124 modules = mod; 125 126 return mod; 127 } 128 129 /* A hash of all exported symbols, 130 * struct symbol is also used for lists of unresolved symbols */ 131 132 #define SYMBOL_HASH_SIZE 1024 133 134 struct symbol { 135 struct symbol *next; 136 struct module *module; 137 unsigned int crc; 138 int crc_valid; 139 unsigned int weak:1; 140 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */ 141 unsigned int kernel:1; /* 1 if symbol is from kernel 142 * (only for external modules) **/ 143 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */ 144 enum export export; /* Type of export */ 145 char name[0]; 146 }; 147 148 static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 149 150 /* This is based on the hash agorithm from gdbm, via tdb */ 151 static inline unsigned int tdb_hash(const char *name) 152 { 153 unsigned value; /* Used to compute the hash value. */ 154 unsigned i; /* Used to cycle through random values. */ 155 156 /* Set the initial value from the key size. */ 157 for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++) 158 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 159 160 return (1103515243 * value + 12345); 161 } 162 163 /** 164 * Allocate a new symbols for use in the hash of exported symbols or 165 * the list of unresolved symbols per module 166 **/ 167 static struct symbol *alloc_symbol(const char *name, unsigned int weak, 168 struct symbol *next) 169 { 170 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 171 172 memset(s, 0, sizeof(*s)); 173 strcpy(s->name, name); 174 s->weak = weak; 175 s->next = next; 176 return s; 177 } 178 179 /* For the hash of exported symbols */ 180 static struct symbol *new_symbol(const char *name, struct module *module, 181 enum export export) 182 { 183 unsigned int hash; 184 struct symbol *new; 185 186 hash = tdb_hash(name) % SYMBOL_HASH_SIZE; 187 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]); 188 new->module = module; 189 new->export = export; 190 return new; 191 } 192 193 static struct symbol *find_symbol(const char *name) 194 { 195 struct symbol *s; 196 197 /* For our purposes, .foo matches foo. PPC64 needs this. */ 198 if (name[0] == '.') 199 name++; 200 201 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s=s->next) { 202 if (strcmp(s->name, name) == 0) 203 return s; 204 } 205 return NULL; 206 } 207 208 static struct { 209 const char *str; 210 enum export export; 211 } export_list[] = { 212 { .str = "EXPORT_SYMBOL", .export = export_plain }, 213 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused }, 214 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl }, 215 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl }, 216 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future }, 217 { .str = "(unknown)", .export = export_unknown }, 218 }; 219 220 221 static const char *export_str(enum export ex) 222 { 223 return export_list[ex].str; 224 } 225 226 static enum export export_no(const char * s) 227 { 228 int i; 229 if (!s) 230 return export_unknown; 231 for (i = 0; export_list[i].export != export_unknown; i++) { 232 if (strcmp(export_list[i].str, s) == 0) 233 return export_list[i].export; 234 } 235 return export_unknown; 236 } 237 238 static enum export export_from_sec(struct elf_info *elf, Elf_Section sec) 239 { 240 if (sec == elf->export_sec) 241 return export_plain; 242 else if (sec == elf->export_unused_sec) 243 return export_unused; 244 else if (sec == elf->export_gpl_sec) 245 return export_gpl; 246 else if (sec == elf->export_unused_gpl_sec) 247 return export_unused_gpl; 248 else if (sec == elf->export_gpl_future_sec) 249 return export_gpl_future; 250 else 251 return export_unknown; 252 } 253 254 /** 255 * Add an exported symbol - it may have already been added without a 256 * CRC, in this case just update the CRC 257 **/ 258 static struct symbol *sym_add_exported(const char *name, struct module *mod, 259 enum export export) 260 { 261 struct symbol *s = find_symbol(name); 262 263 if (!s) { 264 s = new_symbol(name, mod, export); 265 } else { 266 if (!s->preloaded) { 267 warn("%s: '%s' exported twice. Previous export " 268 "was in %s%s\n", mod->name, name, 269 s->module->name, 270 is_vmlinux(s->module->name) ?"":".ko"); 271 } 272 } 273 s->preloaded = 0; 274 s->vmlinux = is_vmlinux(mod->name); 275 s->kernel = 0; 276 s->export = export; 277 return s; 278 } 279 280 static void sym_update_crc(const char *name, struct module *mod, 281 unsigned int crc, enum export export) 282 { 283 struct symbol *s = find_symbol(name); 284 285 if (!s) 286 s = new_symbol(name, mod, export); 287 s->crc = crc; 288 s->crc_valid = 1; 289 } 290 291 void *grab_file(const char *filename, unsigned long *size) 292 { 293 struct stat st; 294 void *map; 295 int fd; 296 297 fd = open(filename, O_RDONLY); 298 if (fd < 0 || fstat(fd, &st) != 0) 299 return NULL; 300 301 *size = st.st_size; 302 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 303 close(fd); 304 305 if (map == MAP_FAILED) 306 return NULL; 307 return map; 308 } 309 310 /** 311 * Return a copy of the next line in a mmap'ed file. 312 * spaces in the beginning of the line is trimmed away. 313 * Return a pointer to a static buffer. 314 **/ 315 char* get_next_line(unsigned long *pos, void *file, unsigned long size) 316 { 317 static char line[4096]; 318 int skip = 1; 319 size_t len = 0; 320 signed char *p = (signed char *)file + *pos; 321 char *s = line; 322 323 for (; *pos < size ; (*pos)++) 324 { 325 if (skip && isspace(*p)) { 326 p++; 327 continue; 328 } 329 skip = 0; 330 if (*p != '\n' && (*pos < size)) { 331 len++; 332 *s++ = *p++; 333 if (len > 4095) 334 break; /* Too long, stop */ 335 } else { 336 /* End of string */ 337 *s = '\0'; 338 return line; 339 } 340 } 341 /* End of buffer */ 342 return NULL; 343 } 344 345 void release_file(void *file, unsigned long size) 346 { 347 munmap(file, size); 348 } 349 350 static int parse_elf(struct elf_info *info, const char *filename) 351 { 352 unsigned int i; 353 Elf_Ehdr *hdr; 354 Elf_Shdr *sechdrs; 355 Elf_Sym *sym; 356 357 hdr = grab_file(filename, &info->size); 358 if (!hdr) { 359 perror(filename); 360 exit(1); 361 } 362 info->hdr = hdr; 363 if (info->size < sizeof(*hdr)) { 364 /* file too small, assume this is an empty .o file */ 365 return 0; 366 } 367 /* Is this a valid ELF file? */ 368 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 369 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 370 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 371 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 372 /* Not an ELF file - silently ignore it */ 373 return 0; 374 } 375 /* Fix endianness in ELF header */ 376 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 377 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 378 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 379 hdr->e_machine = TO_NATIVE(hdr->e_machine); 380 hdr->e_type = TO_NATIVE(hdr->e_type); 381 sechdrs = (void *)hdr + hdr->e_shoff; 382 info->sechdrs = sechdrs; 383 384 /* Fix endianness in section headers */ 385 for (i = 0; i < hdr->e_shnum; i++) { 386 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 387 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 388 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 389 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 390 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 391 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 392 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 393 } 394 /* Find symbol table. */ 395 for (i = 1; i < hdr->e_shnum; i++) { 396 const char *secstrings 397 = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; 398 const char *secname; 399 400 if (sechdrs[i].sh_offset > info->size) { 401 fatal("%s is truncated. sechdrs[i].sh_offset=%u > sizeof(*hrd)=%ul\n", filename, (unsigned int)sechdrs[i].sh_offset, sizeof(*hdr)); 402 return 0; 403 } 404 secname = secstrings + sechdrs[i].sh_name; 405 if (strcmp(secname, ".modinfo") == 0) { 406 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 407 info->modinfo_len = sechdrs[i].sh_size; 408 } else if (strcmp(secname, "__ksymtab") == 0) 409 info->export_sec = i; 410 else if (strcmp(secname, "__ksymtab_unused") == 0) 411 info->export_unused_sec = i; 412 else if (strcmp(secname, "__ksymtab_gpl") == 0) 413 info->export_gpl_sec = i; 414 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0) 415 info->export_unused_gpl_sec = i; 416 else if (strcmp(secname, "__ksymtab_gpl_future") == 0) 417 info->export_gpl_future_sec = i; 418 419 if (sechdrs[i].sh_type != SHT_SYMTAB) 420 continue; 421 422 info->symtab_start = (void *)hdr + sechdrs[i].sh_offset; 423 info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset 424 + sechdrs[i].sh_size; 425 info->strtab = (void *)hdr + 426 sechdrs[sechdrs[i].sh_link].sh_offset; 427 } 428 if (!info->symtab_start) { 429 fatal("%s has no symtab?\n", filename); 430 } 431 /* Fix endianness in symbols */ 432 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 433 sym->st_shndx = TO_NATIVE(sym->st_shndx); 434 sym->st_name = TO_NATIVE(sym->st_name); 435 sym->st_value = TO_NATIVE(sym->st_value); 436 sym->st_size = TO_NATIVE(sym->st_size); 437 } 438 return 1; 439 } 440 441 static void parse_elf_finish(struct elf_info *info) 442 { 443 release_file(info->hdr, info->size); 444 } 445 446 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_" 447 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_" 448 449 static void handle_modversions(struct module *mod, struct elf_info *info, 450 Elf_Sym *sym, const char *symname) 451 { 452 unsigned int crc; 453 enum export export = export_from_sec(info, sym->st_shndx); 454 455 switch (sym->st_shndx) { 456 case SHN_COMMON: 457 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 458 break; 459 case SHN_ABS: 460 /* CRC'd symbol */ 461 if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { 462 crc = (unsigned int) sym->st_value; 463 sym_update_crc(symname + strlen(CRC_PFX), mod, crc, 464 export); 465 } 466 break; 467 case SHN_UNDEF: 468 /* undefined symbol */ 469 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 470 ELF_ST_BIND(sym->st_info) != STB_WEAK) 471 break; 472 /* ignore global offset table */ 473 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 474 break; 475 /* ignore __this_module, it will be resolved shortly */ 476 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0) 477 break; 478 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */ 479 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER) 480 /* add compatibility with older glibc */ 481 #ifndef STT_SPARC_REGISTER 482 #define STT_SPARC_REGISTER STT_REGISTER 483 #endif 484 if (info->hdr->e_machine == EM_SPARC || 485 info->hdr->e_machine == EM_SPARCV9) { 486 /* Ignore register directives. */ 487 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 488 break; 489 if (symname[0] == '.') { 490 char *munged = strdup(symname); 491 munged[0] = '_'; 492 munged[1] = toupper(munged[1]); 493 symname = munged; 494 } 495 } 496 #endif 497 498 if (memcmp(symname, MODULE_SYMBOL_PREFIX, 499 strlen(MODULE_SYMBOL_PREFIX)) == 0) 500 mod->unres = alloc_symbol(symname + 501 strlen(MODULE_SYMBOL_PREFIX), 502 ELF_ST_BIND(sym->st_info) == STB_WEAK, 503 mod->unres); 504 break; 505 default: 506 /* All exported symbols */ 507 if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) { 508 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod, 509 export); 510 } 511 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0) 512 mod->has_init = 1; 513 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0) 514 mod->has_cleanup = 1; 515 break; 516 } 517 } 518 519 /** 520 * Parse tag=value strings from .modinfo section 521 **/ 522 static char *next_string(char *string, unsigned long *secsize) 523 { 524 /* Skip non-zero chars */ 525 while (string[0]) { 526 string++; 527 if ((*secsize)-- <= 1) 528 return NULL; 529 } 530 531 /* Skip any zero padding. */ 532 while (!string[0]) { 533 string++; 534 if ((*secsize)-- <= 1) 535 return NULL; 536 } 537 return string; 538 } 539 540 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len, 541 const char *tag, char *info) 542 { 543 char *p; 544 unsigned int taglen = strlen(tag); 545 unsigned long size = modinfo_len; 546 547 if (info) { 548 size -= info - (char *)modinfo; 549 modinfo = next_string(info, &size); 550 } 551 552 for (p = modinfo; p; p = next_string(p, &size)) { 553 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 554 return p + taglen + 1; 555 } 556 return NULL; 557 } 558 559 static char *get_modinfo(void *modinfo, unsigned long modinfo_len, 560 const char *tag) 561 562 { 563 return get_next_modinfo(modinfo, modinfo_len, tag, NULL); 564 } 565 566 /** 567 * Test if string s ends in string sub 568 * return 0 if match 569 **/ 570 static int strrcmp(const char *s, const char *sub) 571 { 572 int slen, sublen; 573 574 if (!s || !sub) 575 return 1; 576 577 slen = strlen(s); 578 sublen = strlen(sub); 579 580 if ((slen == 0) || (sublen == 0)) 581 return 1; 582 583 if (sublen > slen) 584 return 1; 585 586 return memcmp(s + slen - sublen, sub, sublen); 587 } 588 589 /* 590 * Functions used only during module init is marked __init and is stored in 591 * a .init.text section. Likewise data is marked __initdata and stored in 592 * a .init.data section. 593 * If this section is one of these sections return 1 594 * See include/linux/init.h for the details 595 */ 596 static int init_section(const char *name) 597 { 598 if (strcmp(name, ".init") == 0) 599 return 1; 600 if (strncmp(name, ".init.", strlen(".init.")) == 0) 601 return 1; 602 return 0; 603 } 604 605 /* 606 * Functions used only during module exit is marked __exit and is stored in 607 * a .exit.text section. Likewise data is marked __exitdata and stored in 608 * a .exit.data section. 609 * If this section is one of these sections return 1 610 * See include/linux/init.h for the details 611 **/ 612 static int exit_section(const char *name) 613 { 614 if (strcmp(name, ".exit.text") == 0) 615 return 1; 616 if (strcmp(name, ".exit.data") == 0) 617 return 1; 618 return 0; 619 620 } 621 622 /* 623 * Data sections are named like this: 624 * .data | .data.rel | .data.rel.* 625 * Return 1 if the specified section is a data section 626 */ 627 static int data_section(const char *name) 628 { 629 if ((strcmp(name, ".data") == 0) || 630 (strcmp(name, ".data.rel") == 0) || 631 (strncmp(name, ".data.rel.", strlen(".data.rel.")) == 0)) 632 return 1; 633 else 634 return 0; 635 } 636 637 /** 638 * Whitelist to allow certain references to pass with no warning. 639 * 640 * Pattern 0: 641 * Do not warn if funtion/data are marked with __init_refok/__initdata_refok. 642 * The pattern is identified by: 643 * fromsec = .text.init.refok* | .data.init.refok* 644 * 645 * Pattern 1: 646 * If a module parameter is declared __initdata and permissions=0 647 * then this is legal despite the warning generated. 648 * We cannot see value of permissions here, so just ignore 649 * this pattern. 650 * The pattern is identified by: 651 * tosec = .init.data 652 * fromsec = .data* 653 * atsym =__param* 654 * 655 * Pattern 2: 656 * Many drivers utilise a *driver container with references to 657 * add, remove, probe functions etc. 658 * These functions may often be marked __init and we do not want to 659 * warn here. 660 * the pattern is identified by: 661 * tosec = init or exit section 662 * fromsec = data section 663 * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one, *_console, *_timer 664 * 665 * Pattern 3: 666 * Whitelist all refereces from .text.head to .init.data 667 * Whitelist all refereces from .text.head to .init.text 668 * 669 * Pattern 4: 670 * Some symbols belong to init section but still it is ok to reference 671 * these from non-init sections as these symbols don't have any memory 672 * allocated for them and symbol address and value are same. So even 673 * if init section is freed, its ok to reference those symbols. 674 * For ex. symbols marking the init section boundaries. 675 * This pattern is identified by 676 * refsymname = __init_begin, _sinittext, _einittext 677 * 678 * Pattern 5: 679 * Xtensa uses literal sections for constants that are accessed PC-relative. 680 * Literal sections may safely reference their text sections. 681 * (Note that the name for the literal section omits any trailing '.text') 682 * tosec = <section>[.text] 683 * fromsec = <section>.literal 684 **/ 685 static int secref_whitelist(const char *modname, const char *tosec, 686 const char *fromsec, const char *atsym, 687 const char *refsymname) 688 { 689 int len; 690 const char **s; 691 const char *pat2sym[] = { 692 "driver", 693 "_template", /* scsi uses *_template a lot */ 694 "_timer", /* arm uses ops structures named _timer a lot */ 695 "_sht", /* scsi also used *_sht to some extent */ 696 "_ops", 697 "_probe", 698 "_probe_one", 699 "_console", 700 NULL 701 }; 702 703 const char *pat3refsym[] = { 704 "__init_begin", 705 "_sinittext", 706 "_einittext", 707 NULL 708 }; 709 710 /* Check for pattern 0 */ 711 if ((strncmp(fromsec, ".text.init.refok", strlen(".text.init.refok")) == 0) || 712 (strncmp(fromsec, ".exit.text.refok", strlen(".exit.text.refok")) == 0) || 713 (strncmp(fromsec, ".data.init.refok", strlen(".data.init.refok")) == 0)) 714 return 1; 715 716 /* Check for pattern 1 */ 717 if ((strcmp(tosec, ".init.data") == 0) && 718 (strncmp(fromsec, ".data", strlen(".data")) == 0) && 719 (strncmp(atsym, "__param", strlen("__param")) == 0)) 720 return 1; 721 722 /* Check for pattern 2 */ 723 if ((init_section(tosec) || exit_section(tosec)) && data_section(fromsec)) 724 for (s = pat2sym; *s; s++) 725 if (strrcmp(atsym, *s) == 0) 726 return 1; 727 728 /* Check for pattern 3 */ 729 if ((strcmp(fromsec, ".text.head") == 0) && 730 ((strcmp(tosec, ".init.data") == 0) || 731 (strcmp(tosec, ".init.text") == 0))) 732 return 1; 733 734 /* Check for pattern 4 */ 735 for (s = pat3refsym; *s; s++) 736 if (strcmp(refsymname, *s) == 0) 737 return 1; 738 739 /* Check for pattern 5 */ 740 if (strrcmp(tosec, ".text") == 0) 741 len = strlen(tosec) - strlen(".text"); 742 else 743 len = strlen(tosec); 744 if ((strncmp(tosec, fromsec, len) == 0) && (strlen(fromsec) > len) && 745 (strcmp(fromsec + len, ".literal") == 0)) 746 return 1; 747 748 return 0; 749 } 750 751 /** 752 * Find symbol based on relocation record info. 753 * In some cases the symbol supplied is a valid symbol so 754 * return refsym. If st_name != 0 we assume this is a valid symbol. 755 * In other cases the symbol needs to be looked up in the symbol table 756 * based on section and address. 757 * **/ 758 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr, 759 Elf_Sym *relsym) 760 { 761 Elf_Sym *sym; 762 763 if (relsym->st_name != 0) 764 return relsym; 765 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 766 if (sym->st_shndx != relsym->st_shndx) 767 continue; 768 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) 769 continue; 770 if (sym->st_value == addr) 771 return sym; 772 } 773 return NULL; 774 } 775 776 static inline int is_arm_mapping_symbol(const char *str) 777 { 778 return str[0] == '$' && strchr("atd", str[1]) 779 && (str[2] == '\0' || str[2] == '.'); 780 } 781 782 /* 783 * If there's no name there, ignore it; likewise, ignore it if it's 784 * one of the magic symbols emitted used by current ARM tools. 785 * 786 * Otherwise if find_symbols_between() returns those symbols, they'll 787 * fail the whitelist tests and cause lots of false alarms ... fixable 788 * only by merging __exit and __init sections into __text, bloating 789 * the kernel (which is especially evil on embedded platforms). 790 */ 791 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 792 { 793 const char *name = elf->strtab + sym->st_name; 794 795 if (!name || !strlen(name)) 796 return 0; 797 return !is_arm_mapping_symbol(name); 798 } 799 800 /* 801 * Find symbols before or equal addr and after addr - in the section sec. 802 * If we find two symbols with equal offset prefer one with a valid name. 803 * The ELF format may have a better way to detect what type of symbol 804 * it is, but this works for now. 805 **/ 806 static void find_symbols_between(struct elf_info *elf, Elf_Addr addr, 807 const char *sec, 808 Elf_Sym **before, Elf_Sym **after) 809 { 810 Elf_Sym *sym; 811 Elf_Ehdr *hdr = elf->hdr; 812 Elf_Addr beforediff = ~0; 813 Elf_Addr afterdiff = ~0; 814 const char *secstrings = (void *)hdr + 815 elf->sechdrs[hdr->e_shstrndx].sh_offset; 816 817 *before = NULL; 818 *after = NULL; 819 820 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 821 const char *symsec; 822 823 if (sym->st_shndx >= SHN_LORESERVE) 824 continue; 825 symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name; 826 if (strcmp(symsec, sec) != 0) 827 continue; 828 if (!is_valid_name(elf, sym)) 829 continue; 830 if (sym->st_value <= addr) { 831 if ((addr - sym->st_value) < beforediff) { 832 beforediff = addr - sym->st_value; 833 *before = sym; 834 } 835 else if ((addr - sym->st_value) == beforediff) { 836 *before = sym; 837 } 838 } 839 else 840 { 841 if ((sym->st_value - addr) < afterdiff) { 842 afterdiff = sym->st_value - addr; 843 *after = sym; 844 } 845 else if ((sym->st_value - addr) == afterdiff) { 846 *after = sym; 847 } 848 } 849 } 850 } 851 852 /** 853 * Print a warning about a section mismatch. 854 * Try to find symbols near it so user can find it. 855 * Check whitelist before warning - it may be a false positive. 856 **/ 857 static void warn_sec_mismatch(const char *modname, const char *fromsec, 858 struct elf_info *elf, Elf_Sym *sym, Elf_Rela r) 859 { 860 const char *refsymname = ""; 861 Elf_Sym *before, *after; 862 Elf_Sym *refsym; 863 Elf_Ehdr *hdr = elf->hdr; 864 Elf_Shdr *sechdrs = elf->sechdrs; 865 const char *secstrings = (void *)hdr + 866 sechdrs[hdr->e_shstrndx].sh_offset; 867 const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name; 868 869 find_symbols_between(elf, r.r_offset, fromsec, &before, &after); 870 871 refsym = find_elf_symbol(elf, r.r_addend, sym); 872 if (refsym && strlen(elf->strtab + refsym->st_name)) 873 refsymname = elf->strtab + refsym->st_name; 874 875 /* check whitelist - we may ignore it */ 876 if (secref_whitelist(modname, secname, fromsec, 877 before ? elf->strtab + before->st_name : "", 878 refsymname)) 879 return; 880 881 if (before && after) { 882 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " 883 "(between '%s' and '%s')\n", 884 modname, fromsec, (unsigned long long)r.r_offset, 885 secname, refsymname, 886 elf->strtab + before->st_name, 887 elf->strtab + after->st_name); 888 } else if (before) { 889 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " 890 "(after '%s')\n", 891 modname, fromsec, (unsigned long long)r.r_offset, 892 secname, refsymname, 893 elf->strtab + before->st_name); 894 } else if (after) { 895 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " 896 "before '%s' (at offset -0x%llx)\n", 897 modname, fromsec, (unsigned long long)r.r_offset, 898 secname, refsymname, 899 elf->strtab + after->st_name); 900 } else { 901 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s\n", 902 modname, fromsec, (unsigned long long)r.r_offset, 903 secname, refsymname); 904 } 905 } 906 907 static unsigned int *reloc_location(struct elf_info *elf, 908 int rsection, Elf_Rela *r) 909 { 910 Elf_Shdr *sechdrs = elf->sechdrs; 911 int section = sechdrs[rsection].sh_info; 912 913 return (void *)elf->hdr + sechdrs[section].sh_offset + 914 (r->r_offset - sechdrs[section].sh_addr); 915 } 916 917 static int addend_386_rel(struct elf_info *elf, int rsection, Elf_Rela *r) 918 { 919 unsigned int r_typ = ELF_R_TYPE(r->r_info); 920 unsigned int *location = reloc_location(elf, rsection, r); 921 922 switch (r_typ) { 923 case R_386_32: 924 r->r_addend = TO_NATIVE(*location); 925 break; 926 case R_386_PC32: 927 r->r_addend = TO_NATIVE(*location) + 4; 928 /* For CONFIG_RELOCATABLE=y */ 929 if (elf->hdr->e_type == ET_EXEC) 930 r->r_addend += r->r_offset; 931 break; 932 } 933 return 0; 934 } 935 936 static int addend_arm_rel(struct elf_info *elf, int rsection, Elf_Rela *r) 937 { 938 unsigned int r_typ = ELF_R_TYPE(r->r_info); 939 940 switch (r_typ) { 941 case R_ARM_ABS32: 942 /* From ARM ABI: (S + A) | T */ 943 r->r_addend = (int)(long)(elf->symtab_start + ELF_R_SYM(r->r_info)); 944 break; 945 case R_ARM_PC24: 946 /* From ARM ABI: ((S + A) | T) - P */ 947 r->r_addend = (int)(long)(elf->hdr + elf->sechdrs[rsection].sh_offset + 948 (r->r_offset - elf->sechdrs[rsection].sh_addr)); 949 break; 950 default: 951 return 1; 952 } 953 return 0; 954 } 955 956 static int addend_mips_rel(struct elf_info *elf, int rsection, Elf_Rela *r) 957 { 958 unsigned int r_typ = ELF_R_TYPE(r->r_info); 959 unsigned int *location = reloc_location(elf, rsection, r); 960 unsigned int inst; 961 962 if (r_typ == R_MIPS_HI16) 963 return 1; /* skip this */ 964 inst = TO_NATIVE(*location); 965 switch (r_typ) { 966 case R_MIPS_LO16: 967 r->r_addend = inst & 0xffff; 968 break; 969 case R_MIPS_26: 970 r->r_addend = (inst & 0x03ffffff) << 2; 971 break; 972 case R_MIPS_32: 973 r->r_addend = inst; 974 break; 975 } 976 return 0; 977 } 978 979 /** 980 * A module includes a number of sections that are discarded 981 * either when loaded or when used as built-in. 982 * For loaded modules all functions marked __init and all data 983 * marked __initdata will be discarded when the module has been intialized. 984 * Likewise for modules used built-in the sections marked __exit 985 * are discarded because __exit marked function are supposed to be called 986 * only when a moduel is unloaded which never happes for built-in modules. 987 * The check_sec_ref() function traverses all relocation records 988 * to find all references to a section that reference a section that will 989 * be discarded and warns about it. 990 **/ 991 static void check_sec_ref(struct module *mod, const char *modname, 992 struct elf_info *elf, 993 int section(const char*), 994 int section_ref_ok(const char *)) 995 { 996 int i; 997 Elf_Sym *sym; 998 Elf_Ehdr *hdr = elf->hdr; 999 Elf_Shdr *sechdrs = elf->sechdrs; 1000 const char *secstrings = (void *)hdr + 1001 sechdrs[hdr->e_shstrndx].sh_offset; 1002 1003 /* Walk through all sections */ 1004 for (i = 0; i < hdr->e_shnum; i++) { 1005 const char *name = secstrings + sechdrs[i].sh_name; 1006 const char *secname; 1007 Elf_Rela r; 1008 unsigned int r_sym; 1009 /* We want to process only relocation sections and not .init */ 1010 if (sechdrs[i].sh_type == SHT_RELA) { 1011 Elf_Rela *rela; 1012 Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset; 1013 Elf_Rela *stop = (void*)start + sechdrs[i].sh_size; 1014 name += strlen(".rela"); 1015 if (section_ref_ok(name)) 1016 continue; 1017 1018 for (rela = start; rela < stop; rela++) { 1019 r.r_offset = TO_NATIVE(rela->r_offset); 1020 #if KERNEL_ELFCLASS == ELFCLASS64 1021 if (hdr->e_machine == EM_MIPS) { 1022 unsigned int r_typ; 1023 r_sym = ELF64_MIPS_R_SYM(rela->r_info); 1024 r_sym = TO_NATIVE(r_sym); 1025 r_typ = ELF64_MIPS_R_TYPE(rela->r_info); 1026 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1027 } else { 1028 r.r_info = TO_NATIVE(rela->r_info); 1029 r_sym = ELF_R_SYM(r.r_info); 1030 } 1031 #else 1032 r.r_info = TO_NATIVE(rela->r_info); 1033 r_sym = ELF_R_SYM(r.r_info); 1034 #endif 1035 r.r_addend = TO_NATIVE(rela->r_addend); 1036 sym = elf->symtab_start + r_sym; 1037 /* Skip special sections */ 1038 if (sym->st_shndx >= SHN_LORESERVE) 1039 continue; 1040 1041 secname = secstrings + 1042 sechdrs[sym->st_shndx].sh_name; 1043 if (section(secname)) 1044 warn_sec_mismatch(modname, name, 1045 elf, sym, r); 1046 } 1047 } else if (sechdrs[i].sh_type == SHT_REL) { 1048 Elf_Rel *rel; 1049 Elf_Rel *start = (void *)hdr + sechdrs[i].sh_offset; 1050 Elf_Rel *stop = (void*)start + sechdrs[i].sh_size; 1051 name += strlen(".rel"); 1052 if (section_ref_ok(name)) 1053 continue; 1054 1055 for (rel = start; rel < stop; rel++) { 1056 r.r_offset = TO_NATIVE(rel->r_offset); 1057 #if KERNEL_ELFCLASS == ELFCLASS64 1058 if (hdr->e_machine == EM_MIPS) { 1059 unsigned int r_typ; 1060 r_sym = ELF64_MIPS_R_SYM(rel->r_info); 1061 r_sym = TO_NATIVE(r_sym); 1062 r_typ = ELF64_MIPS_R_TYPE(rel->r_info); 1063 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1064 } else { 1065 r.r_info = TO_NATIVE(rel->r_info); 1066 r_sym = ELF_R_SYM(r.r_info); 1067 } 1068 #else 1069 r.r_info = TO_NATIVE(rel->r_info); 1070 r_sym = ELF_R_SYM(r.r_info); 1071 #endif 1072 r.r_addend = 0; 1073 switch (hdr->e_machine) { 1074 case EM_386: 1075 if (addend_386_rel(elf, i, &r)) 1076 continue; 1077 break; 1078 case EM_ARM: 1079 if(addend_arm_rel(elf, i, &r)) 1080 continue; 1081 break; 1082 case EM_MIPS: 1083 if (addend_mips_rel(elf, i, &r)) 1084 continue; 1085 break; 1086 } 1087 sym = elf->symtab_start + r_sym; 1088 /* Skip special sections */ 1089 if (sym->st_shndx >= SHN_LORESERVE) 1090 continue; 1091 1092 secname = secstrings + 1093 sechdrs[sym->st_shndx].sh_name; 1094 if (section(secname)) 1095 warn_sec_mismatch(modname, name, 1096 elf, sym, r); 1097 } 1098 } 1099 } 1100 } 1101 1102 /* 1103 * Identify sections from which references to either a 1104 * .init or a .exit section is OK. 1105 * 1106 * [OPD] Keith Ownes <kaos@sgi.com> commented: 1107 * For our future {in}sanity, add a comment that this is the ppc .opd 1108 * section, not the ia64 .opd section. 1109 * ia64 .opd should not point to discarded sections. 1110 * [.rodata] like for .init.text we ignore .rodata references -same reason 1111 */ 1112 static int initexit_section_ref_ok(const char *name) 1113 { 1114 const char **s; 1115 /* Absolute section names */ 1116 const char *namelist1[] = { 1117 "__bug_table", /* used by powerpc for BUG() */ 1118 "__ex_table", 1119 ".altinstructions", 1120 ".cranges", /* used by sh64 */ 1121 ".fixup", 1122 ".machvec", /* ia64 + powerpc uses these */ 1123 ".machine.desc", 1124 ".opd", /* See comment [OPD] */ 1125 "__dbe_table", 1126 ".parainstructions", 1127 ".pdr", 1128 ".plt", /* seen on ARCH=um build on x86_64. Harmless */ 1129 ".smp_locks", 1130 ".stab", 1131 ".m68k_fixup", 1132 ".xt.prop", /* xtensa informational section */ 1133 ".xt.lit", /* xtensa informational section */ 1134 NULL 1135 }; 1136 /* Start of section names */ 1137 const char *namelist2[] = { 1138 ".debug", 1139 ".eh_frame", 1140 ".note", /* ignore ELF notes - may contain anything */ 1141 ".got", /* powerpc - global offset table */ 1142 ".toc", /* powerpc - table of contents */ 1143 NULL 1144 }; 1145 /* part of section name */ 1146 const char *namelist3 [] = { 1147 ".unwind", /* Sample: IA_64.unwind.exit.text */ 1148 NULL 1149 }; 1150 1151 for (s = namelist1; *s; s++) 1152 if (strcmp(*s, name) == 0) 1153 return 1; 1154 for (s = namelist2; *s; s++) 1155 if (strncmp(*s, name, strlen(*s)) == 0) 1156 return 1; 1157 for (s = namelist3; *s; s++) 1158 if (strstr(name, *s) != NULL) 1159 return 1; 1160 return 0; 1161 } 1162 1163 1164 /* 1165 * Identify sections from which references to a .init section is OK. 1166 * 1167 * Unfortunately references to read only data that referenced .init 1168 * sections had to be excluded. Almost all of these are false 1169 * positives, they are created by gcc. The downside of excluding rodata 1170 * is that there really are some user references from rodata to 1171 * init code, e.g. drivers/video/vgacon.c: 1172 * 1173 * const struct consw vga_con = { 1174 * con_startup: vgacon_startup, 1175 * 1176 * where vgacon_startup is __init. If you want to wade through the false 1177 * positives, take out the check for rodata. 1178 */ 1179 static int init_section_ref_ok(const char *name) 1180 { 1181 const char **s; 1182 /* Absolute section names */ 1183 const char *namelist1[] = { 1184 "__dbe_table", /* MIPS generate these */ 1185 "__ftr_fixup", /* powerpc cpu feature fixup */ 1186 "__fw_ftr_fixup", /* powerpc firmware feature fixup */ 1187 "__param", 1188 ".data.rel.ro", /* used by parisc64 */ 1189 ".init", 1190 ".text.lock", 1191 NULL 1192 }; 1193 /* Start of section names */ 1194 const char *namelist2[] = { 1195 ".init.", 1196 ".pci_fixup", 1197 ".rodata", 1198 NULL 1199 }; 1200 1201 if (initexit_section_ref_ok(name)) 1202 return 1; 1203 1204 for (s = namelist1; *s; s++) 1205 if (strcmp(*s, name) == 0) 1206 return 1; 1207 for (s = namelist2; *s; s++) 1208 if (strncmp(*s, name, strlen(*s)) == 0) 1209 return 1; 1210 1211 /* If section name ends with ".init" we allow references 1212 * as is the case with .initcallN.init, .early_param.init, .taglist.init etc 1213 */ 1214 if (strrcmp(name, ".init") == 0) 1215 return 1; 1216 return 0; 1217 } 1218 1219 /* 1220 * Identify sections from which references to a .exit section is OK. 1221 */ 1222 static int exit_section_ref_ok(const char *name) 1223 { 1224 const char **s; 1225 /* Absolute section names */ 1226 const char *namelist1[] = { 1227 ".exit.data", 1228 ".exit.text", 1229 ".exitcall.exit", 1230 ".rodata", 1231 NULL 1232 }; 1233 1234 if (initexit_section_ref_ok(name)) 1235 return 1; 1236 1237 for (s = namelist1; *s; s++) 1238 if (strcmp(*s, name) == 0) 1239 return 1; 1240 return 0; 1241 } 1242 1243 static void read_symbols(char *modname) 1244 { 1245 const char *symname; 1246 char *version; 1247 char *license; 1248 struct module *mod; 1249 struct elf_info info = { }; 1250 Elf_Sym *sym; 1251 1252 if (!parse_elf(&info, modname)) 1253 return; 1254 1255 mod = new_module(modname); 1256 1257 /* When there's no vmlinux, don't print warnings about 1258 * unresolved symbols (since there'll be too many ;) */ 1259 if (is_vmlinux(modname)) { 1260 have_vmlinux = 1; 1261 mod->skip = 1; 1262 } 1263 1264 license = get_modinfo(info.modinfo, info.modinfo_len, "license"); 1265 while (license) { 1266 if (license_is_gpl_compatible(license)) 1267 mod->gpl_compatible = 1; 1268 else { 1269 mod->gpl_compatible = 0; 1270 break; 1271 } 1272 license = get_next_modinfo(info.modinfo, info.modinfo_len, 1273 "license", license); 1274 } 1275 1276 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1277 symname = info.strtab + sym->st_name; 1278 1279 handle_modversions(mod, &info, sym, symname); 1280 handle_moddevtable(mod, &info, sym, symname); 1281 } 1282 if (is_vmlinux(modname) && vmlinux_section_warnings) { 1283 check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok); 1284 check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok); 1285 } 1286 1287 version = get_modinfo(info.modinfo, info.modinfo_len, "version"); 1288 if (version) 1289 maybe_frob_rcs_version(modname, version, info.modinfo, 1290 version - (char *)info.hdr); 1291 if (version || (all_versions && !is_vmlinux(modname))) 1292 get_src_version(modname, mod->srcversion, 1293 sizeof(mod->srcversion)-1); 1294 1295 parse_elf_finish(&info); 1296 1297 /* Our trick to get versioning for struct_module - it's 1298 * never passed as an argument to an exported function, so 1299 * the automatic versioning doesn't pick it up, but it's really 1300 * important anyhow */ 1301 if (modversions) 1302 mod->unres = alloc_symbol("struct_module", 0, mod->unres); 1303 } 1304 1305 #define SZ 500 1306 1307 /* We first write the generated file into memory using the 1308 * following helper, then compare to the file on disk and 1309 * only update the later if anything changed */ 1310 1311 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1312 const char *fmt, ...) 1313 { 1314 char tmp[SZ]; 1315 int len; 1316 va_list ap; 1317 1318 va_start(ap, fmt); 1319 len = vsnprintf(tmp, SZ, fmt, ap); 1320 buf_write(buf, tmp, len); 1321 va_end(ap); 1322 } 1323 1324 void buf_write(struct buffer *buf, const char *s, int len) 1325 { 1326 if (buf->size - buf->pos < len) { 1327 buf->size += len + SZ; 1328 buf->p = realloc(buf->p, buf->size); 1329 } 1330 strncpy(buf->p + buf->pos, s, len); 1331 buf->pos += len; 1332 } 1333 1334 static void check_for_gpl_usage(enum export exp, const char *m, const char *s) 1335 { 1336 const char *e = is_vmlinux(m) ?"":".ko"; 1337 1338 switch (exp) { 1339 case export_gpl: 1340 fatal("modpost: GPL-incompatible module %s%s " 1341 "uses GPL-only symbol '%s'\n", m, e, s); 1342 break; 1343 case export_unused_gpl: 1344 fatal("modpost: GPL-incompatible module %s%s " 1345 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); 1346 break; 1347 case export_gpl_future: 1348 warn("modpost: GPL-incompatible module %s%s " 1349 "uses future GPL-only symbol '%s'\n", m, e, s); 1350 break; 1351 case export_plain: 1352 case export_unused: 1353 case export_unknown: 1354 /* ignore */ 1355 break; 1356 } 1357 } 1358 1359 static void check_for_unused(enum export exp, const char* m, const char* s) 1360 { 1361 const char *e = is_vmlinux(m) ?"":".ko"; 1362 1363 switch (exp) { 1364 case export_unused: 1365 case export_unused_gpl: 1366 warn("modpost: module %s%s " 1367 "uses symbol '%s' marked UNUSED\n", m, e, s); 1368 break; 1369 default: 1370 /* ignore */ 1371 break; 1372 } 1373 } 1374 1375 static void check_exports(struct module *mod) 1376 { 1377 struct symbol *s, *exp; 1378 1379 for (s = mod->unres; s; s = s->next) { 1380 const char *basename; 1381 exp = find_symbol(s->name); 1382 if (!exp || exp->module == mod) 1383 continue; 1384 basename = strrchr(mod->name, '/'); 1385 if (basename) 1386 basename++; 1387 else 1388 basename = mod->name; 1389 if (!mod->gpl_compatible) 1390 check_for_gpl_usage(exp->export, basename, exp->name); 1391 check_for_unused(exp->export, basename, exp->name); 1392 } 1393 } 1394 1395 /** 1396 * Header for the generated file 1397 **/ 1398 static void add_header(struct buffer *b, struct module *mod) 1399 { 1400 buf_printf(b, "#include <linux/module.h>\n"); 1401 buf_printf(b, "#include <linux/vermagic.h>\n"); 1402 buf_printf(b, "#include <linux/compiler.h>\n"); 1403 buf_printf(b, "\n"); 1404 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1405 buf_printf(b, "\n"); 1406 buf_printf(b, "struct module __this_module\n"); 1407 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); 1408 buf_printf(b, " .name = KBUILD_MODNAME,\n"); 1409 if (mod->has_init) 1410 buf_printf(b, " .init = init_module,\n"); 1411 if (mod->has_cleanup) 1412 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1413 " .exit = cleanup_module,\n" 1414 "#endif\n"); 1415 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n"); 1416 buf_printf(b, "};\n"); 1417 } 1418 1419 /** 1420 * Record CRCs for unresolved symbols 1421 **/ 1422 static int add_versions(struct buffer *b, struct module *mod) 1423 { 1424 struct symbol *s, *exp; 1425 int err = 0; 1426 1427 for (s = mod->unres; s; s = s->next) { 1428 exp = find_symbol(s->name); 1429 if (!exp || exp->module == mod) { 1430 if (have_vmlinux && !s->weak) { 1431 if (warn_unresolved) { 1432 warn("\"%s\" [%s.ko] undefined!\n", 1433 s->name, mod->name); 1434 } else { 1435 merror("\"%s\" [%s.ko] undefined!\n", 1436 s->name, mod->name); 1437 err = 1; 1438 } 1439 } 1440 continue; 1441 } 1442 s->module = exp->module; 1443 s->crc_valid = exp->crc_valid; 1444 s->crc = exp->crc; 1445 } 1446 1447 if (!modversions) 1448 return err; 1449 1450 buf_printf(b, "\n"); 1451 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1452 buf_printf(b, "__attribute_used__\n"); 1453 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); 1454 1455 for (s = mod->unres; s; s = s->next) { 1456 if (!s->module) { 1457 continue; 1458 } 1459 if (!s->crc_valid) { 1460 warn("\"%s\" [%s.ko] has no CRC!\n", 1461 s->name, mod->name); 1462 continue; 1463 } 1464 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); 1465 } 1466 1467 buf_printf(b, "};\n"); 1468 1469 return err; 1470 } 1471 1472 static void add_depends(struct buffer *b, struct module *mod, 1473 struct module *modules) 1474 { 1475 struct symbol *s; 1476 struct module *m; 1477 int first = 1; 1478 1479 for (m = modules; m; m = m->next) { 1480 m->seen = is_vmlinux(m->name); 1481 } 1482 1483 buf_printf(b, "\n"); 1484 buf_printf(b, "static const char __module_depends[]\n"); 1485 buf_printf(b, "__attribute_used__\n"); 1486 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); 1487 buf_printf(b, "\"depends="); 1488 for (s = mod->unres; s; s = s->next) { 1489 const char *p; 1490 if (!s->module) 1491 continue; 1492 1493 if (s->module->seen) 1494 continue; 1495 1496 s->module->seen = 1; 1497 if ((p = strrchr(s->module->name, '/')) != NULL) 1498 p++; 1499 else 1500 p = s->module->name; 1501 buf_printf(b, "%s%s", first ? "" : ",", p); 1502 first = 0; 1503 } 1504 buf_printf(b, "\";\n"); 1505 } 1506 1507 static void add_srcversion(struct buffer *b, struct module *mod) 1508 { 1509 if (mod->srcversion[0]) { 1510 buf_printf(b, "\n"); 1511 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1512 mod->srcversion); 1513 } 1514 } 1515 1516 static void write_if_changed(struct buffer *b, const char *fname) 1517 { 1518 char *tmp; 1519 FILE *file; 1520 struct stat st; 1521 1522 file = fopen(fname, "r"); 1523 if (!file) 1524 goto write; 1525 1526 if (fstat(fileno(file), &st) < 0) 1527 goto close_write; 1528 1529 if (st.st_size != b->pos) 1530 goto close_write; 1531 1532 tmp = NOFAIL(malloc(b->pos)); 1533 if (fread(tmp, 1, b->pos, file) != b->pos) 1534 goto free_write; 1535 1536 if (memcmp(tmp, b->p, b->pos) != 0) 1537 goto free_write; 1538 1539 free(tmp); 1540 fclose(file); 1541 return; 1542 1543 free_write: 1544 free(tmp); 1545 close_write: 1546 fclose(file); 1547 write: 1548 file = fopen(fname, "w"); 1549 if (!file) { 1550 perror(fname); 1551 exit(1); 1552 } 1553 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1554 perror(fname); 1555 exit(1); 1556 } 1557 fclose(file); 1558 } 1559 1560 /* parse Module.symvers file. line format: 1561 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] 1562 **/ 1563 static void read_dump(const char *fname, unsigned int kernel) 1564 { 1565 unsigned long size, pos = 0; 1566 void *file = grab_file(fname, &size); 1567 char *line; 1568 1569 if (!file) 1570 /* No symbol versions, silently ignore */ 1571 return; 1572 1573 while ((line = get_next_line(&pos, file, size))) { 1574 char *symname, *modname, *d, *export, *end; 1575 unsigned int crc; 1576 struct module *mod; 1577 struct symbol *s; 1578 1579 if (!(symname = strchr(line, '\t'))) 1580 goto fail; 1581 *symname++ = '\0'; 1582 if (!(modname = strchr(symname, '\t'))) 1583 goto fail; 1584 *modname++ = '\0'; 1585 if ((export = strchr(modname, '\t')) != NULL) 1586 *export++ = '\0'; 1587 if (export && ((end = strchr(export, '\t')) != NULL)) 1588 *end = '\0'; 1589 crc = strtoul(line, &d, 16); 1590 if (*symname == '\0' || *modname == '\0' || *d != '\0') 1591 goto fail; 1592 1593 if (!(mod = find_module(modname))) { 1594 if (is_vmlinux(modname)) { 1595 have_vmlinux = 1; 1596 } 1597 mod = new_module(NOFAIL(strdup(modname))); 1598 mod->skip = 1; 1599 } 1600 s = sym_add_exported(symname, mod, export_no(export)); 1601 s->kernel = kernel; 1602 s->preloaded = 1; 1603 sym_update_crc(symname, mod, crc, export_no(export)); 1604 } 1605 return; 1606 fail: 1607 fatal("parse error in symbol dump file\n"); 1608 } 1609 1610 /* For normal builds always dump all symbols. 1611 * For external modules only dump symbols 1612 * that are not read from kernel Module.symvers. 1613 **/ 1614 static int dump_sym(struct symbol *sym) 1615 { 1616 if (!external_module) 1617 return 1; 1618 if (sym->vmlinux || sym->kernel) 1619 return 0; 1620 return 1; 1621 } 1622 1623 static void write_dump(const char *fname) 1624 { 1625 struct buffer buf = { }; 1626 struct symbol *symbol; 1627 int n; 1628 1629 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { 1630 symbol = symbolhash[n]; 1631 while (symbol) { 1632 if (dump_sym(symbol)) 1633 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", 1634 symbol->crc, symbol->name, 1635 symbol->module->name, 1636 export_str(symbol->export)); 1637 symbol = symbol->next; 1638 } 1639 } 1640 write_if_changed(&buf, fname); 1641 } 1642 1643 int main(int argc, char **argv) 1644 { 1645 struct module *mod; 1646 struct buffer buf = { }; 1647 char fname[SZ]; 1648 char *kernel_read = NULL, *module_read = NULL; 1649 char *dump_write = NULL; 1650 int opt; 1651 int err; 1652 1653 while ((opt = getopt(argc, argv, "i:I:mso:aw")) != -1) { 1654 switch(opt) { 1655 case 'i': 1656 kernel_read = optarg; 1657 break; 1658 case 'I': 1659 module_read = optarg; 1660 external_module = 1; 1661 break; 1662 case 'm': 1663 modversions = 1; 1664 break; 1665 case 'o': 1666 dump_write = optarg; 1667 break; 1668 case 'a': 1669 all_versions = 1; 1670 break; 1671 case 's': 1672 vmlinux_section_warnings = 0; 1673 break; 1674 case 'w': 1675 warn_unresolved = 1; 1676 break; 1677 default: 1678 exit(1); 1679 } 1680 } 1681 1682 if (kernel_read) 1683 read_dump(kernel_read, 1); 1684 if (module_read) 1685 read_dump(module_read, 0); 1686 1687 while (optind < argc) { 1688 read_symbols(argv[optind++]); 1689 } 1690 1691 for (mod = modules; mod; mod = mod->next) { 1692 if (mod->skip) 1693 continue; 1694 check_exports(mod); 1695 } 1696 1697 err = 0; 1698 1699 for (mod = modules; mod; mod = mod->next) { 1700 if (mod->skip) 1701 continue; 1702 1703 buf.pos = 0; 1704 1705 add_header(&buf, mod); 1706 err |= add_versions(&buf, mod); 1707 add_depends(&buf, mod, modules); 1708 add_moddevtable(&buf, mod); 1709 add_srcversion(&buf, mod); 1710 1711 sprintf(fname, "%s.mod.c", mod->name); 1712 write_if_changed(&buf, fname); 1713 } 1714 1715 if (dump_write) 1716 write_dump(dump_write); 1717 1718 return err; 1719 } 1720