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 /* Check if file offset is correct */ 385 if (hdr->e_shoff > info->size) { 386 fatal("section header offset=%u in file '%s' is bigger then filesize=%lu\n", hdr->e_shoff, filename, info->size); 387 return 0; 388 } 389 390 /* Fix endianness in section headers */ 391 for (i = 0; i < hdr->e_shnum; i++) { 392 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 393 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 394 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 395 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 396 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 397 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); 398 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); 399 } 400 /* Find symbol table. */ 401 for (i = 1; i < hdr->e_shnum; i++) { 402 const char *secstrings 403 = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; 404 const char *secname; 405 406 if (sechdrs[i].sh_offset > info->size) { 407 fatal("%s is truncated. sechdrs[i].sh_offset=%u > sizeof(*hrd)=%ul\n", filename, (unsigned int)sechdrs[i].sh_offset, sizeof(*hdr)); 408 return 0; 409 } 410 secname = secstrings + sechdrs[i].sh_name; 411 if (strcmp(secname, ".modinfo") == 0) { 412 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 413 info->modinfo_len = sechdrs[i].sh_size; 414 } else if (strcmp(secname, "__ksymtab") == 0) 415 info->export_sec = i; 416 else if (strcmp(secname, "__ksymtab_unused") == 0) 417 info->export_unused_sec = i; 418 else if (strcmp(secname, "__ksymtab_gpl") == 0) 419 info->export_gpl_sec = i; 420 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0) 421 info->export_unused_gpl_sec = i; 422 else if (strcmp(secname, "__ksymtab_gpl_future") == 0) 423 info->export_gpl_future_sec = i; 424 425 if (sechdrs[i].sh_type != SHT_SYMTAB) 426 continue; 427 428 info->symtab_start = (void *)hdr + sechdrs[i].sh_offset; 429 info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset 430 + sechdrs[i].sh_size; 431 info->strtab = (void *)hdr + 432 sechdrs[sechdrs[i].sh_link].sh_offset; 433 } 434 if (!info->symtab_start) { 435 fatal("%s has no symtab?\n", filename); 436 } 437 /* Fix endianness in symbols */ 438 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 439 sym->st_shndx = TO_NATIVE(sym->st_shndx); 440 sym->st_name = TO_NATIVE(sym->st_name); 441 sym->st_value = TO_NATIVE(sym->st_value); 442 sym->st_size = TO_NATIVE(sym->st_size); 443 } 444 return 1; 445 } 446 447 static void parse_elf_finish(struct elf_info *info) 448 { 449 release_file(info->hdr, info->size); 450 } 451 452 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_" 453 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_" 454 455 static void handle_modversions(struct module *mod, struct elf_info *info, 456 Elf_Sym *sym, const char *symname) 457 { 458 unsigned int crc; 459 enum export export = export_from_sec(info, sym->st_shndx); 460 461 switch (sym->st_shndx) { 462 case SHN_COMMON: 463 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 464 break; 465 case SHN_ABS: 466 /* CRC'd symbol */ 467 if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { 468 crc = (unsigned int) sym->st_value; 469 sym_update_crc(symname + strlen(CRC_PFX), mod, crc, 470 export); 471 } 472 break; 473 case SHN_UNDEF: 474 /* undefined symbol */ 475 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 476 ELF_ST_BIND(sym->st_info) != STB_WEAK) 477 break; 478 /* ignore global offset table */ 479 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 480 break; 481 /* ignore __this_module, it will be resolved shortly */ 482 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0) 483 break; 484 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */ 485 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER) 486 /* add compatibility with older glibc */ 487 #ifndef STT_SPARC_REGISTER 488 #define STT_SPARC_REGISTER STT_REGISTER 489 #endif 490 if (info->hdr->e_machine == EM_SPARC || 491 info->hdr->e_machine == EM_SPARCV9) { 492 /* Ignore register directives. */ 493 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 494 break; 495 if (symname[0] == '.') { 496 char *munged = strdup(symname); 497 munged[0] = '_'; 498 munged[1] = toupper(munged[1]); 499 symname = munged; 500 } 501 } 502 #endif 503 504 if (memcmp(symname, MODULE_SYMBOL_PREFIX, 505 strlen(MODULE_SYMBOL_PREFIX)) == 0) 506 mod->unres = alloc_symbol(symname + 507 strlen(MODULE_SYMBOL_PREFIX), 508 ELF_ST_BIND(sym->st_info) == STB_WEAK, 509 mod->unres); 510 break; 511 default: 512 /* All exported symbols */ 513 if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) { 514 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod, 515 export); 516 } 517 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0) 518 mod->has_init = 1; 519 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0) 520 mod->has_cleanup = 1; 521 break; 522 } 523 } 524 525 /** 526 * Parse tag=value strings from .modinfo section 527 **/ 528 static char *next_string(char *string, unsigned long *secsize) 529 { 530 /* Skip non-zero chars */ 531 while (string[0]) { 532 string++; 533 if ((*secsize)-- <= 1) 534 return NULL; 535 } 536 537 /* Skip any zero padding. */ 538 while (!string[0]) { 539 string++; 540 if ((*secsize)-- <= 1) 541 return NULL; 542 } 543 return string; 544 } 545 546 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len, 547 const char *tag, char *info) 548 { 549 char *p; 550 unsigned int taglen = strlen(tag); 551 unsigned long size = modinfo_len; 552 553 if (info) { 554 size -= info - (char *)modinfo; 555 modinfo = next_string(info, &size); 556 } 557 558 for (p = modinfo; p; p = next_string(p, &size)) { 559 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 560 return p + taglen + 1; 561 } 562 return NULL; 563 } 564 565 static char *get_modinfo(void *modinfo, unsigned long modinfo_len, 566 const char *tag) 567 568 { 569 return get_next_modinfo(modinfo, modinfo_len, tag, NULL); 570 } 571 572 /** 573 * Test if string s ends in string sub 574 * return 0 if match 575 **/ 576 static int strrcmp(const char *s, const char *sub) 577 { 578 int slen, sublen; 579 580 if (!s || !sub) 581 return 1; 582 583 slen = strlen(s); 584 sublen = strlen(sub); 585 586 if ((slen == 0) || (sublen == 0)) 587 return 1; 588 589 if (sublen > slen) 590 return 1; 591 592 return memcmp(s + slen - sublen, sub, sublen); 593 } 594 595 /* 596 * Functions used only during module init is marked __init and is stored in 597 * a .init.text section. Likewise data is marked __initdata and stored in 598 * a .init.data section. 599 * If this section is one of these sections return 1 600 * See include/linux/init.h for the details 601 */ 602 static int init_section(const char *name) 603 { 604 if (strcmp(name, ".init") == 0) 605 return 1; 606 if (strncmp(name, ".init.", strlen(".init.")) == 0) 607 return 1; 608 return 0; 609 } 610 611 /* 612 * Functions used only during module exit is marked __exit and is stored in 613 * a .exit.text section. Likewise data is marked __exitdata and stored in 614 * a .exit.data section. 615 * If this section is one of these sections return 1 616 * See include/linux/init.h for the details 617 **/ 618 static int exit_section(const char *name) 619 { 620 if (strcmp(name, ".exit.text") == 0) 621 return 1; 622 if (strcmp(name, ".exit.data") == 0) 623 return 1; 624 return 0; 625 626 } 627 628 /* 629 * Data sections are named like this: 630 * .data | .data.rel | .data.rel.* 631 * Return 1 if the specified section is a data section 632 */ 633 static int data_section(const char *name) 634 { 635 if ((strcmp(name, ".data") == 0) || 636 (strcmp(name, ".data.rel") == 0) || 637 (strncmp(name, ".data.rel.", strlen(".data.rel.")) == 0)) 638 return 1; 639 else 640 return 0; 641 } 642 643 /** 644 * Whitelist to allow certain references to pass with no warning. 645 * 646 * Pattern 0: 647 * Do not warn if funtion/data are marked with __init_refok/__initdata_refok. 648 * The pattern is identified by: 649 * fromsec = .text.init.refok* | .data.init.refok* 650 * 651 * Pattern 1: 652 * If a module parameter is declared __initdata and permissions=0 653 * then this is legal despite the warning generated. 654 * We cannot see value of permissions here, so just ignore 655 * this pattern. 656 * The pattern is identified by: 657 * tosec = .init.data 658 * fromsec = .data* 659 * atsym =__param* 660 * 661 * Pattern 2: 662 * Many drivers utilise a *driver container with references to 663 * add, remove, probe functions etc. 664 * These functions may often be marked __init and we do not want to 665 * warn here. 666 * the pattern is identified by: 667 * tosec = init or exit section 668 * fromsec = data section 669 * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one, *_console, *_timer 670 * 671 * Pattern 3: 672 * Whitelist all refereces from .text.head to .init.data 673 * Whitelist all refereces from .text.head to .init.text 674 * 675 * Pattern 4: 676 * Some symbols belong to init section but still it is ok to reference 677 * these from non-init sections as these symbols don't have any memory 678 * allocated for them and symbol address and value are same. So even 679 * if init section is freed, its ok to reference those symbols. 680 * For ex. symbols marking the init section boundaries. 681 * This pattern is identified by 682 * refsymname = __init_begin, _sinittext, _einittext 683 * 684 * Pattern 5: 685 * Xtensa uses literal sections for constants that are accessed PC-relative. 686 * Literal sections may safely reference their text sections. 687 * (Note that the name for the literal section omits any trailing '.text') 688 * tosec = <section>[.text] 689 * fromsec = <section>.literal 690 **/ 691 static int secref_whitelist(const char *modname, const char *tosec, 692 const char *fromsec, const char *atsym, 693 const char *refsymname) 694 { 695 int len; 696 const char **s; 697 const char *pat2sym[] = { 698 "driver", 699 "_template", /* scsi uses *_template a lot */ 700 "_timer", /* arm uses ops structures named _timer a lot */ 701 "_sht", /* scsi also used *_sht to some extent */ 702 "_ops", 703 "_probe", 704 "_probe_one", 705 "_console", 706 NULL 707 }; 708 709 const char *pat3refsym[] = { 710 "__init_begin", 711 "_sinittext", 712 "_einittext", 713 NULL 714 }; 715 716 /* Check for pattern 0 */ 717 if ((strncmp(fromsec, ".text.init.refok", strlen(".text.init.refok")) == 0) || 718 (strncmp(fromsec, ".exit.text.refok", strlen(".exit.text.refok")) == 0) || 719 (strncmp(fromsec, ".data.init.refok", strlen(".data.init.refok")) == 0)) 720 return 1; 721 722 /* Check for pattern 1 */ 723 if ((strcmp(tosec, ".init.data") == 0) && 724 (strncmp(fromsec, ".data", strlen(".data")) == 0) && 725 (strncmp(atsym, "__param", strlen("__param")) == 0)) 726 return 1; 727 728 /* Check for pattern 2 */ 729 if ((init_section(tosec) || exit_section(tosec)) && data_section(fromsec)) 730 for (s = pat2sym; *s; s++) 731 if (strrcmp(atsym, *s) == 0) 732 return 1; 733 734 /* Check for pattern 3 */ 735 if ((strcmp(fromsec, ".text.head") == 0) && 736 ((strcmp(tosec, ".init.data") == 0) || 737 (strcmp(tosec, ".init.text") == 0))) 738 return 1; 739 740 /* Check for pattern 4 */ 741 for (s = pat3refsym; *s; s++) 742 if (strcmp(refsymname, *s) == 0) 743 return 1; 744 745 /* Check for pattern 5 */ 746 if (strrcmp(tosec, ".text") == 0) 747 len = strlen(tosec) - strlen(".text"); 748 else 749 len = strlen(tosec); 750 if ((strncmp(tosec, fromsec, len) == 0) && (strlen(fromsec) > len) && 751 (strcmp(fromsec + len, ".literal") == 0)) 752 return 1; 753 754 return 0; 755 } 756 757 /** 758 * Find symbol based on relocation record info. 759 * In some cases the symbol supplied is a valid symbol so 760 * return refsym. If st_name != 0 we assume this is a valid symbol. 761 * In other cases the symbol needs to be looked up in the symbol table 762 * based on section and address. 763 * **/ 764 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr, 765 Elf_Sym *relsym) 766 { 767 Elf_Sym *sym; 768 769 if (relsym->st_name != 0) 770 return relsym; 771 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 772 if (sym->st_shndx != relsym->st_shndx) 773 continue; 774 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) 775 continue; 776 if (sym->st_value == addr) 777 return sym; 778 } 779 return NULL; 780 } 781 782 static inline int is_arm_mapping_symbol(const char *str) 783 { 784 return str[0] == '$' && strchr("atd", str[1]) 785 && (str[2] == '\0' || str[2] == '.'); 786 } 787 788 /* 789 * If there's no name there, ignore it; likewise, ignore it if it's 790 * one of the magic symbols emitted used by current ARM tools. 791 * 792 * Otherwise if find_symbols_between() returns those symbols, they'll 793 * fail the whitelist tests and cause lots of false alarms ... fixable 794 * only by merging __exit and __init sections into __text, bloating 795 * the kernel (which is especially evil on embedded platforms). 796 */ 797 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 798 { 799 const char *name = elf->strtab + sym->st_name; 800 801 if (!name || !strlen(name)) 802 return 0; 803 return !is_arm_mapping_symbol(name); 804 } 805 806 /* 807 * Find symbols before or equal addr and after addr - in the section sec. 808 * If we find two symbols with equal offset prefer one with a valid name. 809 * The ELF format may have a better way to detect what type of symbol 810 * it is, but this works for now. 811 **/ 812 static void find_symbols_between(struct elf_info *elf, Elf_Addr addr, 813 const char *sec, 814 Elf_Sym **before, Elf_Sym **after) 815 { 816 Elf_Sym *sym; 817 Elf_Ehdr *hdr = elf->hdr; 818 Elf_Addr beforediff = ~0; 819 Elf_Addr afterdiff = ~0; 820 const char *secstrings = (void *)hdr + 821 elf->sechdrs[hdr->e_shstrndx].sh_offset; 822 823 *before = NULL; 824 *after = NULL; 825 826 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 827 const char *symsec; 828 829 if (sym->st_shndx >= SHN_LORESERVE) 830 continue; 831 symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name; 832 if (strcmp(symsec, sec) != 0) 833 continue; 834 if (!is_valid_name(elf, sym)) 835 continue; 836 if (sym->st_value <= addr) { 837 if ((addr - sym->st_value) < beforediff) { 838 beforediff = addr - sym->st_value; 839 *before = sym; 840 } 841 else if ((addr - sym->st_value) == beforediff) { 842 *before = sym; 843 } 844 } 845 else 846 { 847 if ((sym->st_value - addr) < afterdiff) { 848 afterdiff = sym->st_value - addr; 849 *after = sym; 850 } 851 else if ((sym->st_value - addr) == afterdiff) { 852 *after = sym; 853 } 854 } 855 } 856 } 857 858 /** 859 * Print a warning about a section mismatch. 860 * Try to find symbols near it so user can find it. 861 * Check whitelist before warning - it may be a false positive. 862 **/ 863 static void warn_sec_mismatch(const char *modname, const char *fromsec, 864 struct elf_info *elf, Elf_Sym *sym, Elf_Rela r) 865 { 866 const char *refsymname = ""; 867 Elf_Sym *before, *after; 868 Elf_Sym *refsym; 869 Elf_Ehdr *hdr = elf->hdr; 870 Elf_Shdr *sechdrs = elf->sechdrs; 871 const char *secstrings = (void *)hdr + 872 sechdrs[hdr->e_shstrndx].sh_offset; 873 const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name; 874 875 find_symbols_between(elf, r.r_offset, fromsec, &before, &after); 876 877 refsym = find_elf_symbol(elf, r.r_addend, sym); 878 if (refsym && strlen(elf->strtab + refsym->st_name)) 879 refsymname = elf->strtab + refsym->st_name; 880 881 /* check whitelist - we may ignore it */ 882 if (secref_whitelist(modname, secname, fromsec, 883 before ? elf->strtab + before->st_name : "", 884 refsymname)) 885 return; 886 887 if (before && after) { 888 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " 889 "(between '%s' and '%s')\n", 890 modname, fromsec, (unsigned long long)r.r_offset, 891 secname, refsymname, 892 elf->strtab + before->st_name, 893 elf->strtab + after->st_name); 894 } else if (before) { 895 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " 896 "(after '%s')\n", 897 modname, fromsec, (unsigned long long)r.r_offset, 898 secname, refsymname, 899 elf->strtab + before->st_name); 900 } else if (after) { 901 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " 902 "before '%s' (at offset -0x%llx)\n", 903 modname, fromsec, (unsigned long long)r.r_offset, 904 secname, refsymname, 905 elf->strtab + after->st_name); 906 } else { 907 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s\n", 908 modname, fromsec, (unsigned long long)r.r_offset, 909 secname, refsymname); 910 } 911 } 912 913 static unsigned int *reloc_location(struct elf_info *elf, 914 int rsection, Elf_Rela *r) 915 { 916 Elf_Shdr *sechdrs = elf->sechdrs; 917 int section = sechdrs[rsection].sh_info; 918 919 return (void *)elf->hdr + sechdrs[section].sh_offset + 920 (r->r_offset - sechdrs[section].sh_addr); 921 } 922 923 static int addend_386_rel(struct elf_info *elf, int rsection, Elf_Rela *r) 924 { 925 unsigned int r_typ = ELF_R_TYPE(r->r_info); 926 unsigned int *location = reloc_location(elf, rsection, r); 927 928 switch (r_typ) { 929 case R_386_32: 930 r->r_addend = TO_NATIVE(*location); 931 break; 932 case R_386_PC32: 933 r->r_addend = TO_NATIVE(*location) + 4; 934 /* For CONFIG_RELOCATABLE=y */ 935 if (elf->hdr->e_type == ET_EXEC) 936 r->r_addend += r->r_offset; 937 break; 938 } 939 return 0; 940 } 941 942 static int addend_arm_rel(struct elf_info *elf, int rsection, Elf_Rela *r) 943 { 944 unsigned int r_typ = ELF_R_TYPE(r->r_info); 945 946 switch (r_typ) { 947 case R_ARM_ABS32: 948 /* From ARM ABI: (S + A) | T */ 949 r->r_addend = (int)(long)(elf->symtab_start + ELF_R_SYM(r->r_info)); 950 break; 951 case R_ARM_PC24: 952 /* From ARM ABI: ((S + A) | T) - P */ 953 r->r_addend = (int)(long)(elf->hdr + elf->sechdrs[rsection].sh_offset + 954 (r->r_offset - elf->sechdrs[rsection].sh_addr)); 955 break; 956 default: 957 return 1; 958 } 959 return 0; 960 } 961 962 static int addend_mips_rel(struct elf_info *elf, int rsection, Elf_Rela *r) 963 { 964 unsigned int r_typ = ELF_R_TYPE(r->r_info); 965 unsigned int *location = reloc_location(elf, rsection, r); 966 unsigned int inst; 967 968 if (r_typ == R_MIPS_HI16) 969 return 1; /* skip this */ 970 inst = TO_NATIVE(*location); 971 switch (r_typ) { 972 case R_MIPS_LO16: 973 r->r_addend = inst & 0xffff; 974 break; 975 case R_MIPS_26: 976 r->r_addend = (inst & 0x03ffffff) << 2; 977 break; 978 case R_MIPS_32: 979 r->r_addend = inst; 980 break; 981 } 982 return 0; 983 } 984 985 /** 986 * A module includes a number of sections that are discarded 987 * either when loaded or when used as built-in. 988 * For loaded modules all functions marked __init and all data 989 * marked __initdata will be discarded when the module has been intialized. 990 * Likewise for modules used built-in the sections marked __exit 991 * are discarded because __exit marked function are supposed to be called 992 * only when a moduel is unloaded which never happes for built-in modules. 993 * The check_sec_ref() function traverses all relocation records 994 * to find all references to a section that reference a section that will 995 * be discarded and warns about it. 996 **/ 997 static void check_sec_ref(struct module *mod, const char *modname, 998 struct elf_info *elf, 999 int section(const char*), 1000 int section_ref_ok(const char *)) 1001 { 1002 int i; 1003 Elf_Sym *sym; 1004 Elf_Ehdr *hdr = elf->hdr; 1005 Elf_Shdr *sechdrs = elf->sechdrs; 1006 const char *secstrings = (void *)hdr + 1007 sechdrs[hdr->e_shstrndx].sh_offset; 1008 1009 /* Walk through all sections */ 1010 for (i = 0; i < hdr->e_shnum; i++) { 1011 const char *name = secstrings + sechdrs[i].sh_name; 1012 const char *secname; 1013 Elf_Rela r; 1014 unsigned int r_sym; 1015 /* We want to process only relocation sections and not .init */ 1016 if (sechdrs[i].sh_type == SHT_RELA) { 1017 Elf_Rela *rela; 1018 Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset; 1019 Elf_Rela *stop = (void*)start + sechdrs[i].sh_size; 1020 name += strlen(".rela"); 1021 if (section_ref_ok(name)) 1022 continue; 1023 1024 for (rela = start; rela < stop; rela++) { 1025 r.r_offset = TO_NATIVE(rela->r_offset); 1026 #if KERNEL_ELFCLASS == ELFCLASS64 1027 if (hdr->e_machine == EM_MIPS) { 1028 unsigned int r_typ; 1029 r_sym = ELF64_MIPS_R_SYM(rela->r_info); 1030 r_sym = TO_NATIVE(r_sym); 1031 r_typ = ELF64_MIPS_R_TYPE(rela->r_info); 1032 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1033 } else { 1034 r.r_info = TO_NATIVE(rela->r_info); 1035 r_sym = ELF_R_SYM(r.r_info); 1036 } 1037 #else 1038 r.r_info = TO_NATIVE(rela->r_info); 1039 r_sym = ELF_R_SYM(r.r_info); 1040 #endif 1041 r.r_addend = TO_NATIVE(rela->r_addend); 1042 sym = elf->symtab_start + r_sym; 1043 /* Skip special sections */ 1044 if (sym->st_shndx >= SHN_LORESERVE) 1045 continue; 1046 1047 secname = secstrings + 1048 sechdrs[sym->st_shndx].sh_name; 1049 if (section(secname)) 1050 warn_sec_mismatch(modname, name, 1051 elf, sym, r); 1052 } 1053 } else if (sechdrs[i].sh_type == SHT_REL) { 1054 Elf_Rel *rel; 1055 Elf_Rel *start = (void *)hdr + sechdrs[i].sh_offset; 1056 Elf_Rel *stop = (void*)start + sechdrs[i].sh_size; 1057 name += strlen(".rel"); 1058 if (section_ref_ok(name)) 1059 continue; 1060 1061 for (rel = start; rel < stop; rel++) { 1062 r.r_offset = TO_NATIVE(rel->r_offset); 1063 #if KERNEL_ELFCLASS == ELFCLASS64 1064 if (hdr->e_machine == EM_MIPS) { 1065 unsigned int r_typ; 1066 r_sym = ELF64_MIPS_R_SYM(rel->r_info); 1067 r_sym = TO_NATIVE(r_sym); 1068 r_typ = ELF64_MIPS_R_TYPE(rel->r_info); 1069 r.r_info = ELF64_R_INFO(r_sym, r_typ); 1070 } else { 1071 r.r_info = TO_NATIVE(rel->r_info); 1072 r_sym = ELF_R_SYM(r.r_info); 1073 } 1074 #else 1075 r.r_info = TO_NATIVE(rel->r_info); 1076 r_sym = ELF_R_SYM(r.r_info); 1077 #endif 1078 r.r_addend = 0; 1079 switch (hdr->e_machine) { 1080 case EM_386: 1081 if (addend_386_rel(elf, i, &r)) 1082 continue; 1083 break; 1084 case EM_ARM: 1085 if(addend_arm_rel(elf, i, &r)) 1086 continue; 1087 break; 1088 case EM_MIPS: 1089 if (addend_mips_rel(elf, i, &r)) 1090 continue; 1091 break; 1092 } 1093 sym = elf->symtab_start + r_sym; 1094 /* Skip special sections */ 1095 if (sym->st_shndx >= SHN_LORESERVE) 1096 continue; 1097 1098 secname = secstrings + 1099 sechdrs[sym->st_shndx].sh_name; 1100 if (section(secname)) 1101 warn_sec_mismatch(modname, name, 1102 elf, sym, r); 1103 } 1104 } 1105 } 1106 } 1107 1108 /* 1109 * Identify sections from which references to either a 1110 * .init or a .exit section is OK. 1111 * 1112 * [OPD] Keith Ownes <kaos@sgi.com> commented: 1113 * For our future {in}sanity, add a comment that this is the ppc .opd 1114 * section, not the ia64 .opd section. 1115 * ia64 .opd should not point to discarded sections. 1116 * [.rodata] like for .init.text we ignore .rodata references -same reason 1117 */ 1118 static int initexit_section_ref_ok(const char *name) 1119 { 1120 const char **s; 1121 /* Absolute section names */ 1122 const char *namelist1[] = { 1123 "__bug_table", /* used by powerpc for BUG() */ 1124 "__ex_table", 1125 ".altinstructions", 1126 ".cranges", /* used by sh64 */ 1127 ".fixup", 1128 ".machvec", /* ia64 + powerpc uses these */ 1129 ".machine.desc", 1130 ".opd", /* See comment [OPD] */ 1131 "__dbe_table", 1132 ".parainstructions", 1133 ".pdr", 1134 ".plt", /* seen on ARCH=um build on x86_64. Harmless */ 1135 ".smp_locks", 1136 ".stab", 1137 ".m68k_fixup", 1138 ".xt.prop", /* xtensa informational section */ 1139 ".xt.lit", /* xtensa informational section */ 1140 NULL 1141 }; 1142 /* Start of section names */ 1143 const char *namelist2[] = { 1144 ".debug", 1145 ".eh_frame", 1146 ".note", /* ignore ELF notes - may contain anything */ 1147 ".got", /* powerpc - global offset table */ 1148 ".toc", /* powerpc - table of contents */ 1149 NULL 1150 }; 1151 /* part of section name */ 1152 const char *namelist3 [] = { 1153 ".unwind", /* Sample: IA_64.unwind.exit.text */ 1154 NULL 1155 }; 1156 1157 for (s = namelist1; *s; s++) 1158 if (strcmp(*s, name) == 0) 1159 return 1; 1160 for (s = namelist2; *s; s++) 1161 if (strncmp(*s, name, strlen(*s)) == 0) 1162 return 1; 1163 for (s = namelist3; *s; s++) 1164 if (strstr(name, *s) != NULL) 1165 return 1; 1166 return 0; 1167 } 1168 1169 1170 /* 1171 * Identify sections from which references to a .init section is OK. 1172 * 1173 * Unfortunately references to read only data that referenced .init 1174 * sections had to be excluded. Almost all of these are false 1175 * positives, they are created by gcc. The downside of excluding rodata 1176 * is that there really are some user references from rodata to 1177 * init code, e.g. drivers/video/vgacon.c: 1178 * 1179 * const struct consw vga_con = { 1180 * con_startup: vgacon_startup, 1181 * 1182 * where vgacon_startup is __init. If you want to wade through the false 1183 * positives, take out the check for rodata. 1184 */ 1185 static int init_section_ref_ok(const char *name) 1186 { 1187 const char **s; 1188 /* Absolute section names */ 1189 const char *namelist1[] = { 1190 "__dbe_table", /* MIPS generate these */ 1191 "__ftr_fixup", /* powerpc cpu feature fixup */ 1192 "__fw_ftr_fixup", /* powerpc firmware feature fixup */ 1193 "__param", 1194 ".data.rel.ro", /* used by parisc64 */ 1195 ".init", 1196 ".text.lock", 1197 NULL 1198 }; 1199 /* Start of section names */ 1200 const char *namelist2[] = { 1201 ".init.", 1202 ".pci_fixup", 1203 ".rodata", 1204 NULL 1205 }; 1206 1207 if (initexit_section_ref_ok(name)) 1208 return 1; 1209 1210 for (s = namelist1; *s; s++) 1211 if (strcmp(*s, name) == 0) 1212 return 1; 1213 for (s = namelist2; *s; s++) 1214 if (strncmp(*s, name, strlen(*s)) == 0) 1215 return 1; 1216 1217 /* If section name ends with ".init" we allow references 1218 * as is the case with .initcallN.init, .early_param.init, .taglist.init etc 1219 */ 1220 if (strrcmp(name, ".init") == 0) 1221 return 1; 1222 return 0; 1223 } 1224 1225 /* 1226 * Identify sections from which references to a .exit section is OK. 1227 */ 1228 static int exit_section_ref_ok(const char *name) 1229 { 1230 const char **s; 1231 /* Absolute section names */ 1232 const char *namelist1[] = { 1233 ".exit.data", 1234 ".exit.text", 1235 ".exitcall.exit", 1236 ".rodata", 1237 NULL 1238 }; 1239 1240 if (initexit_section_ref_ok(name)) 1241 return 1; 1242 1243 for (s = namelist1; *s; s++) 1244 if (strcmp(*s, name) == 0) 1245 return 1; 1246 return 0; 1247 } 1248 1249 static void read_symbols(char *modname) 1250 { 1251 const char *symname; 1252 char *version; 1253 char *license; 1254 struct module *mod; 1255 struct elf_info info = { }; 1256 Elf_Sym *sym; 1257 1258 if (!parse_elf(&info, modname)) 1259 return; 1260 1261 mod = new_module(modname); 1262 1263 /* When there's no vmlinux, don't print warnings about 1264 * unresolved symbols (since there'll be too many ;) */ 1265 if (is_vmlinux(modname)) { 1266 have_vmlinux = 1; 1267 mod->skip = 1; 1268 } 1269 1270 license = get_modinfo(info.modinfo, info.modinfo_len, "license"); 1271 while (license) { 1272 if (license_is_gpl_compatible(license)) 1273 mod->gpl_compatible = 1; 1274 else { 1275 mod->gpl_compatible = 0; 1276 break; 1277 } 1278 license = get_next_modinfo(info.modinfo, info.modinfo_len, 1279 "license", license); 1280 } 1281 1282 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1283 symname = info.strtab + sym->st_name; 1284 1285 handle_modversions(mod, &info, sym, symname); 1286 handle_moddevtable(mod, &info, sym, symname); 1287 } 1288 if (is_vmlinux(modname) && vmlinux_section_warnings) { 1289 check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok); 1290 check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok); 1291 } 1292 1293 version = get_modinfo(info.modinfo, info.modinfo_len, "version"); 1294 if (version) 1295 maybe_frob_rcs_version(modname, version, info.modinfo, 1296 version - (char *)info.hdr); 1297 if (version || (all_versions && !is_vmlinux(modname))) 1298 get_src_version(modname, mod->srcversion, 1299 sizeof(mod->srcversion)-1); 1300 1301 parse_elf_finish(&info); 1302 1303 /* Our trick to get versioning for struct_module - it's 1304 * never passed as an argument to an exported function, so 1305 * the automatic versioning doesn't pick it up, but it's really 1306 * important anyhow */ 1307 if (modversions) 1308 mod->unres = alloc_symbol("struct_module", 0, mod->unres); 1309 } 1310 1311 #define SZ 500 1312 1313 /* We first write the generated file into memory using the 1314 * following helper, then compare to the file on disk and 1315 * only update the later if anything changed */ 1316 1317 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1318 const char *fmt, ...) 1319 { 1320 char tmp[SZ]; 1321 int len; 1322 va_list ap; 1323 1324 va_start(ap, fmt); 1325 len = vsnprintf(tmp, SZ, fmt, ap); 1326 buf_write(buf, tmp, len); 1327 va_end(ap); 1328 } 1329 1330 void buf_write(struct buffer *buf, const char *s, int len) 1331 { 1332 if (buf->size - buf->pos < len) { 1333 buf->size += len + SZ; 1334 buf->p = realloc(buf->p, buf->size); 1335 } 1336 strncpy(buf->p + buf->pos, s, len); 1337 buf->pos += len; 1338 } 1339 1340 static void check_for_gpl_usage(enum export exp, const char *m, const char *s) 1341 { 1342 const char *e = is_vmlinux(m) ?"":".ko"; 1343 1344 switch (exp) { 1345 case export_gpl: 1346 fatal("modpost: GPL-incompatible module %s%s " 1347 "uses GPL-only symbol '%s'\n", m, e, s); 1348 break; 1349 case export_unused_gpl: 1350 fatal("modpost: GPL-incompatible module %s%s " 1351 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); 1352 break; 1353 case export_gpl_future: 1354 warn("modpost: GPL-incompatible module %s%s " 1355 "uses future GPL-only symbol '%s'\n", m, e, s); 1356 break; 1357 case export_plain: 1358 case export_unused: 1359 case export_unknown: 1360 /* ignore */ 1361 break; 1362 } 1363 } 1364 1365 static void check_for_unused(enum export exp, const char* m, const char* s) 1366 { 1367 const char *e = is_vmlinux(m) ?"":".ko"; 1368 1369 switch (exp) { 1370 case export_unused: 1371 case export_unused_gpl: 1372 warn("modpost: module %s%s " 1373 "uses symbol '%s' marked UNUSED\n", m, e, s); 1374 break; 1375 default: 1376 /* ignore */ 1377 break; 1378 } 1379 } 1380 1381 static void check_exports(struct module *mod) 1382 { 1383 struct symbol *s, *exp; 1384 1385 for (s = mod->unres; s; s = s->next) { 1386 const char *basename; 1387 exp = find_symbol(s->name); 1388 if (!exp || exp->module == mod) 1389 continue; 1390 basename = strrchr(mod->name, '/'); 1391 if (basename) 1392 basename++; 1393 else 1394 basename = mod->name; 1395 if (!mod->gpl_compatible) 1396 check_for_gpl_usage(exp->export, basename, exp->name); 1397 check_for_unused(exp->export, basename, exp->name); 1398 } 1399 } 1400 1401 /** 1402 * Header for the generated file 1403 **/ 1404 static void add_header(struct buffer *b, struct module *mod) 1405 { 1406 buf_printf(b, "#include <linux/module.h>\n"); 1407 buf_printf(b, "#include <linux/vermagic.h>\n"); 1408 buf_printf(b, "#include <linux/compiler.h>\n"); 1409 buf_printf(b, "\n"); 1410 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1411 buf_printf(b, "\n"); 1412 buf_printf(b, "struct module __this_module\n"); 1413 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); 1414 buf_printf(b, " .name = KBUILD_MODNAME,\n"); 1415 if (mod->has_init) 1416 buf_printf(b, " .init = init_module,\n"); 1417 if (mod->has_cleanup) 1418 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1419 " .exit = cleanup_module,\n" 1420 "#endif\n"); 1421 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n"); 1422 buf_printf(b, "};\n"); 1423 } 1424 1425 /** 1426 * Record CRCs for unresolved symbols 1427 **/ 1428 static int add_versions(struct buffer *b, struct module *mod) 1429 { 1430 struct symbol *s, *exp; 1431 int err = 0; 1432 1433 for (s = mod->unres; s; s = s->next) { 1434 exp = find_symbol(s->name); 1435 if (!exp || exp->module == mod) { 1436 if (have_vmlinux && !s->weak) { 1437 if (warn_unresolved) { 1438 warn("\"%s\" [%s.ko] undefined!\n", 1439 s->name, mod->name); 1440 } else { 1441 merror("\"%s\" [%s.ko] undefined!\n", 1442 s->name, mod->name); 1443 err = 1; 1444 } 1445 } 1446 continue; 1447 } 1448 s->module = exp->module; 1449 s->crc_valid = exp->crc_valid; 1450 s->crc = exp->crc; 1451 } 1452 1453 if (!modversions) 1454 return err; 1455 1456 buf_printf(b, "\n"); 1457 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1458 buf_printf(b, "__attribute_used__\n"); 1459 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); 1460 1461 for (s = mod->unres; s; s = s->next) { 1462 if (!s->module) { 1463 continue; 1464 } 1465 if (!s->crc_valid) { 1466 warn("\"%s\" [%s.ko] has no CRC!\n", 1467 s->name, mod->name); 1468 continue; 1469 } 1470 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); 1471 } 1472 1473 buf_printf(b, "};\n"); 1474 1475 return err; 1476 } 1477 1478 static void add_depends(struct buffer *b, struct module *mod, 1479 struct module *modules) 1480 { 1481 struct symbol *s; 1482 struct module *m; 1483 int first = 1; 1484 1485 for (m = modules; m; m = m->next) { 1486 m->seen = is_vmlinux(m->name); 1487 } 1488 1489 buf_printf(b, "\n"); 1490 buf_printf(b, "static const char __module_depends[]\n"); 1491 buf_printf(b, "__attribute_used__\n"); 1492 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); 1493 buf_printf(b, "\"depends="); 1494 for (s = mod->unres; s; s = s->next) { 1495 const char *p; 1496 if (!s->module) 1497 continue; 1498 1499 if (s->module->seen) 1500 continue; 1501 1502 s->module->seen = 1; 1503 if ((p = strrchr(s->module->name, '/')) != NULL) 1504 p++; 1505 else 1506 p = s->module->name; 1507 buf_printf(b, "%s%s", first ? "" : ",", p); 1508 first = 0; 1509 } 1510 buf_printf(b, "\";\n"); 1511 } 1512 1513 static void add_srcversion(struct buffer *b, struct module *mod) 1514 { 1515 if (mod->srcversion[0]) { 1516 buf_printf(b, "\n"); 1517 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1518 mod->srcversion); 1519 } 1520 } 1521 1522 static void write_if_changed(struct buffer *b, const char *fname) 1523 { 1524 char *tmp; 1525 FILE *file; 1526 struct stat st; 1527 1528 file = fopen(fname, "r"); 1529 if (!file) 1530 goto write; 1531 1532 if (fstat(fileno(file), &st) < 0) 1533 goto close_write; 1534 1535 if (st.st_size != b->pos) 1536 goto close_write; 1537 1538 tmp = NOFAIL(malloc(b->pos)); 1539 if (fread(tmp, 1, b->pos, file) != b->pos) 1540 goto free_write; 1541 1542 if (memcmp(tmp, b->p, b->pos) != 0) 1543 goto free_write; 1544 1545 free(tmp); 1546 fclose(file); 1547 return; 1548 1549 free_write: 1550 free(tmp); 1551 close_write: 1552 fclose(file); 1553 write: 1554 file = fopen(fname, "w"); 1555 if (!file) { 1556 perror(fname); 1557 exit(1); 1558 } 1559 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1560 perror(fname); 1561 exit(1); 1562 } 1563 fclose(file); 1564 } 1565 1566 /* parse Module.symvers file. line format: 1567 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] 1568 **/ 1569 static void read_dump(const char *fname, unsigned int kernel) 1570 { 1571 unsigned long size, pos = 0; 1572 void *file = grab_file(fname, &size); 1573 char *line; 1574 1575 if (!file) 1576 /* No symbol versions, silently ignore */ 1577 return; 1578 1579 while ((line = get_next_line(&pos, file, size))) { 1580 char *symname, *modname, *d, *export, *end; 1581 unsigned int crc; 1582 struct module *mod; 1583 struct symbol *s; 1584 1585 if (!(symname = strchr(line, '\t'))) 1586 goto fail; 1587 *symname++ = '\0'; 1588 if (!(modname = strchr(symname, '\t'))) 1589 goto fail; 1590 *modname++ = '\0'; 1591 if ((export = strchr(modname, '\t')) != NULL) 1592 *export++ = '\0'; 1593 if (export && ((end = strchr(export, '\t')) != NULL)) 1594 *end = '\0'; 1595 crc = strtoul(line, &d, 16); 1596 if (*symname == '\0' || *modname == '\0' || *d != '\0') 1597 goto fail; 1598 1599 if (!(mod = find_module(modname))) { 1600 if (is_vmlinux(modname)) { 1601 have_vmlinux = 1; 1602 } 1603 mod = new_module(NOFAIL(strdup(modname))); 1604 mod->skip = 1; 1605 } 1606 s = sym_add_exported(symname, mod, export_no(export)); 1607 s->kernel = kernel; 1608 s->preloaded = 1; 1609 sym_update_crc(symname, mod, crc, export_no(export)); 1610 } 1611 return; 1612 fail: 1613 fatal("parse error in symbol dump file\n"); 1614 } 1615 1616 /* For normal builds always dump all symbols. 1617 * For external modules only dump symbols 1618 * that are not read from kernel Module.symvers. 1619 **/ 1620 static int dump_sym(struct symbol *sym) 1621 { 1622 if (!external_module) 1623 return 1; 1624 if (sym->vmlinux || sym->kernel) 1625 return 0; 1626 return 1; 1627 } 1628 1629 static void write_dump(const char *fname) 1630 { 1631 struct buffer buf = { }; 1632 struct symbol *symbol; 1633 int n; 1634 1635 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { 1636 symbol = symbolhash[n]; 1637 while (symbol) { 1638 if (dump_sym(symbol)) 1639 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", 1640 symbol->crc, symbol->name, 1641 symbol->module->name, 1642 export_str(symbol->export)); 1643 symbol = symbol->next; 1644 } 1645 } 1646 write_if_changed(&buf, fname); 1647 } 1648 1649 int main(int argc, char **argv) 1650 { 1651 struct module *mod; 1652 struct buffer buf = { }; 1653 char fname[SZ]; 1654 char *kernel_read = NULL, *module_read = NULL; 1655 char *dump_write = NULL; 1656 int opt; 1657 int err; 1658 1659 while ((opt = getopt(argc, argv, "i:I:mso:aw")) != -1) { 1660 switch(opt) { 1661 case 'i': 1662 kernel_read = optarg; 1663 break; 1664 case 'I': 1665 module_read = optarg; 1666 external_module = 1; 1667 break; 1668 case 'm': 1669 modversions = 1; 1670 break; 1671 case 'o': 1672 dump_write = optarg; 1673 break; 1674 case 'a': 1675 all_versions = 1; 1676 break; 1677 case 's': 1678 vmlinux_section_warnings = 0; 1679 break; 1680 case 'w': 1681 warn_unresolved = 1; 1682 break; 1683 default: 1684 exit(1); 1685 } 1686 } 1687 1688 if (kernel_read) 1689 read_dump(kernel_read, 1); 1690 if (module_read) 1691 read_dump(module_read, 0); 1692 1693 while (optind < argc) { 1694 read_symbols(argv[optind++]); 1695 } 1696 1697 for (mod = modules; mod; mod = mod->next) { 1698 if (mod->skip) 1699 continue; 1700 check_exports(mod); 1701 } 1702 1703 err = 0; 1704 1705 for (mod = modules; mod; mod = mod->next) { 1706 if (mod->skip) 1707 continue; 1708 1709 buf.pos = 0; 1710 1711 add_header(&buf, mod); 1712 err |= add_versions(&buf, mod); 1713 add_depends(&buf, mod, modules); 1714 add_moddevtable(&buf, mod); 1715 add_srcversion(&buf, mod); 1716 1717 sprintf(fname, "%s.mod.c", mod->name); 1718 write_if_changed(&buf, fname); 1719 } 1720 1721 if (dump_write) 1722 write_dump(dump_write); 1723 1724 return err; 1725 } 1726