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 /* Only warn about unresolved symbols */ 27 static int warn_unresolved = 0; 28 /* How a symbol is exported */ 29 enum export { 30 export_plain, export_unused, export_gpl, 31 export_unused_gpl, export_gpl_future, export_unknown 32 }; 33 34 void fatal(const char *fmt, ...) 35 { 36 va_list arglist; 37 38 fprintf(stderr, "FATAL: "); 39 40 va_start(arglist, fmt); 41 vfprintf(stderr, fmt, arglist); 42 va_end(arglist); 43 44 exit(1); 45 } 46 47 void warn(const char *fmt, ...) 48 { 49 va_list arglist; 50 51 fprintf(stderr, "WARNING: "); 52 53 va_start(arglist, fmt); 54 vfprintf(stderr, fmt, arglist); 55 va_end(arglist); 56 } 57 58 void merror(const char *fmt, ...) 59 { 60 va_list arglist; 61 62 fprintf(stderr, "ERROR: "); 63 64 va_start(arglist, fmt); 65 vfprintf(stderr, fmt, arglist); 66 va_end(arglist); 67 } 68 69 static int is_vmlinux(const char *modname) 70 { 71 const char *myname; 72 73 if ((myname = strrchr(modname, '/'))) 74 myname++; 75 else 76 myname = modname; 77 78 return strcmp(myname, "vmlinux") == 0; 79 } 80 81 void *do_nofail(void *ptr, const char *expr) 82 { 83 if (!ptr) { 84 fatal("modpost: Memory allocation failure: %s.\n", expr); 85 } 86 return ptr; 87 } 88 89 /* A list of all modules we processed */ 90 91 static struct module *modules; 92 93 static struct module *find_module(char *modname) 94 { 95 struct module *mod; 96 97 for (mod = modules; mod; mod = mod->next) 98 if (strcmp(mod->name, modname) == 0) 99 break; 100 return mod; 101 } 102 103 static struct module *new_module(char *modname) 104 { 105 struct module *mod; 106 char *p, *s; 107 108 mod = NOFAIL(malloc(sizeof(*mod))); 109 memset(mod, 0, sizeof(*mod)); 110 p = NOFAIL(strdup(modname)); 111 112 /* strip trailing .o */ 113 if ((s = strrchr(p, '.')) != NULL) 114 if (strcmp(s, ".o") == 0) 115 *s = '\0'; 116 117 /* add to list */ 118 mod->name = p; 119 mod->gpl_compatible = -1; 120 mod->next = modules; 121 modules = mod; 122 123 return mod; 124 } 125 126 /* A hash of all exported symbols, 127 * struct symbol is also used for lists of unresolved symbols */ 128 129 #define SYMBOL_HASH_SIZE 1024 130 131 struct symbol { 132 struct symbol *next; 133 struct module *module; 134 unsigned int crc; 135 int crc_valid; 136 unsigned int weak:1; 137 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */ 138 unsigned int kernel:1; /* 1 if symbol is from kernel 139 * (only for external modules) **/ 140 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */ 141 enum export export; /* Type of export */ 142 char name[0]; 143 }; 144 145 static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; 146 147 /* This is based on the hash agorithm from gdbm, via tdb */ 148 static inline unsigned int tdb_hash(const char *name) 149 { 150 unsigned value; /* Used to compute the hash value. */ 151 unsigned i; /* Used to cycle through random values. */ 152 153 /* Set the initial value from the key size. */ 154 for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++) 155 value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); 156 157 return (1103515243 * value + 12345); 158 } 159 160 /** 161 * Allocate a new symbols for use in the hash of exported symbols or 162 * the list of unresolved symbols per module 163 **/ 164 static struct symbol *alloc_symbol(const char *name, unsigned int weak, 165 struct symbol *next) 166 { 167 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); 168 169 memset(s, 0, sizeof(*s)); 170 strcpy(s->name, name); 171 s->weak = weak; 172 s->next = next; 173 return s; 174 } 175 176 /* For the hash of exported symbols */ 177 static struct symbol *new_symbol(const char *name, struct module *module, 178 enum export export) 179 { 180 unsigned int hash; 181 struct symbol *new; 182 183 hash = tdb_hash(name) % SYMBOL_HASH_SIZE; 184 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]); 185 new->module = module; 186 new->export = export; 187 return new; 188 } 189 190 static struct symbol *find_symbol(const char *name) 191 { 192 struct symbol *s; 193 194 /* For our purposes, .foo matches foo. PPC64 needs this. */ 195 if (name[0] == '.') 196 name++; 197 198 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s=s->next) { 199 if (strcmp(s->name, name) == 0) 200 return s; 201 } 202 return NULL; 203 } 204 205 static struct { 206 const char *str; 207 enum export export; 208 } export_list[] = { 209 { .str = "EXPORT_SYMBOL", .export = export_plain }, 210 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused }, 211 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl }, 212 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl }, 213 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future }, 214 { .str = "(unknown)", .export = export_unknown }, 215 }; 216 217 218 static const char *export_str(enum export ex) 219 { 220 return export_list[ex].str; 221 } 222 223 static enum export export_no(const char * s) 224 { 225 int i; 226 if (!s) 227 return export_unknown; 228 for (i = 0; export_list[i].export != export_unknown; i++) { 229 if (strcmp(export_list[i].str, s) == 0) 230 return export_list[i].export; 231 } 232 return export_unknown; 233 } 234 235 static enum export export_from_sec(struct elf_info *elf, Elf_Section sec) 236 { 237 if (sec == elf->export_sec) 238 return export_plain; 239 else if (sec == elf->export_unused_sec) 240 return export_unused; 241 else if (sec == elf->export_gpl_sec) 242 return export_gpl; 243 else if (sec == elf->export_unused_gpl_sec) 244 return export_unused_gpl; 245 else if (sec == elf->export_gpl_future_sec) 246 return export_gpl_future; 247 else 248 return export_unknown; 249 } 250 251 /** 252 * Add an exported symbol - it may have already been added without a 253 * CRC, in this case just update the CRC 254 **/ 255 static struct symbol *sym_add_exported(const char *name, struct module *mod, 256 enum export export) 257 { 258 struct symbol *s = find_symbol(name); 259 260 if (!s) { 261 s = new_symbol(name, mod, export); 262 } else { 263 if (!s->preloaded) { 264 warn("%s: '%s' exported twice. Previous export " 265 "was in %s%s\n", mod->name, name, 266 s->module->name, 267 is_vmlinux(s->module->name) ?"":".ko"); 268 } 269 } 270 s->preloaded = 0; 271 s->vmlinux = is_vmlinux(mod->name); 272 s->kernel = 0; 273 s->export = export; 274 return s; 275 } 276 277 static void sym_update_crc(const char *name, struct module *mod, 278 unsigned int crc, enum export export) 279 { 280 struct symbol *s = find_symbol(name); 281 282 if (!s) 283 s = new_symbol(name, mod, export); 284 s->crc = crc; 285 s->crc_valid = 1; 286 } 287 288 void *grab_file(const char *filename, unsigned long *size) 289 { 290 struct stat st; 291 void *map; 292 int fd; 293 294 fd = open(filename, O_RDONLY); 295 if (fd < 0 || fstat(fd, &st) != 0) 296 return NULL; 297 298 *size = st.st_size; 299 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); 300 close(fd); 301 302 if (map == MAP_FAILED) 303 return NULL; 304 return map; 305 } 306 307 /** 308 * Return a copy of the next line in a mmap'ed file. 309 * spaces in the beginning of the line is trimmed away. 310 * Return a pointer to a static buffer. 311 **/ 312 char* get_next_line(unsigned long *pos, void *file, unsigned long size) 313 { 314 static char line[4096]; 315 int skip = 1; 316 size_t len = 0; 317 signed char *p = (signed char *)file + *pos; 318 char *s = line; 319 320 for (; *pos < size ; (*pos)++) 321 { 322 if (skip && isspace(*p)) { 323 p++; 324 continue; 325 } 326 skip = 0; 327 if (*p != '\n' && (*pos < size)) { 328 len++; 329 *s++ = *p++; 330 if (len > 4095) 331 break; /* Too long, stop */ 332 } else { 333 /* End of string */ 334 *s = '\0'; 335 return line; 336 } 337 } 338 /* End of buffer */ 339 return NULL; 340 } 341 342 void release_file(void *file, unsigned long size) 343 { 344 munmap(file, size); 345 } 346 347 static int parse_elf(struct elf_info *info, const char *filename) 348 { 349 unsigned int i; 350 Elf_Ehdr *hdr; 351 Elf_Shdr *sechdrs; 352 Elf_Sym *sym; 353 354 hdr = grab_file(filename, &info->size); 355 if (!hdr) { 356 perror(filename); 357 exit(1); 358 } 359 info->hdr = hdr; 360 if (info->size < sizeof(*hdr)) { 361 /* file too small, assume this is an empty .o file */ 362 return 0; 363 } 364 /* Is this a valid ELF file? */ 365 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || 366 (hdr->e_ident[EI_MAG1] != ELFMAG1) || 367 (hdr->e_ident[EI_MAG2] != ELFMAG2) || 368 (hdr->e_ident[EI_MAG3] != ELFMAG3)) { 369 /* Not an ELF file - silently ignore it */ 370 return 0; 371 } 372 /* Fix endianness in ELF header */ 373 hdr->e_shoff = TO_NATIVE(hdr->e_shoff); 374 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); 375 hdr->e_shnum = TO_NATIVE(hdr->e_shnum); 376 hdr->e_machine = TO_NATIVE(hdr->e_machine); 377 sechdrs = (void *)hdr + hdr->e_shoff; 378 info->sechdrs = sechdrs; 379 380 /* Fix endianness in section headers */ 381 for (i = 0; i < hdr->e_shnum; i++) { 382 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); 383 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); 384 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); 385 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); 386 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); 387 } 388 /* Find symbol table. */ 389 for (i = 1; i < hdr->e_shnum; i++) { 390 const char *secstrings 391 = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; 392 const char *secname; 393 394 if (sechdrs[i].sh_offset > info->size) { 395 fatal("%s is truncated. sechdrs[i].sh_offset=%u > sizeof(*hrd)=%ul\n", filename, (unsigned int)sechdrs[i].sh_offset, sizeof(*hdr)); 396 return 0; 397 } 398 secname = secstrings + sechdrs[i].sh_name; 399 if (strcmp(secname, ".modinfo") == 0) { 400 info->modinfo = (void *)hdr + sechdrs[i].sh_offset; 401 info->modinfo_len = sechdrs[i].sh_size; 402 } else if (strcmp(secname, "__ksymtab") == 0) 403 info->export_sec = i; 404 else if (strcmp(secname, "__ksymtab_unused") == 0) 405 info->export_unused_sec = i; 406 else if (strcmp(secname, "__ksymtab_gpl") == 0) 407 info->export_gpl_sec = i; 408 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0) 409 info->export_unused_gpl_sec = i; 410 else if (strcmp(secname, "__ksymtab_gpl_future") == 0) 411 info->export_gpl_future_sec = i; 412 413 if (sechdrs[i].sh_type != SHT_SYMTAB) 414 continue; 415 416 info->symtab_start = (void *)hdr + sechdrs[i].sh_offset; 417 info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset 418 + sechdrs[i].sh_size; 419 info->strtab = (void *)hdr + 420 sechdrs[sechdrs[i].sh_link].sh_offset; 421 } 422 if (!info->symtab_start) { 423 fatal("%s has no symtab?\n", filename); 424 } 425 /* Fix endianness in symbols */ 426 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { 427 sym->st_shndx = TO_NATIVE(sym->st_shndx); 428 sym->st_name = TO_NATIVE(sym->st_name); 429 sym->st_value = TO_NATIVE(sym->st_value); 430 sym->st_size = TO_NATIVE(sym->st_size); 431 } 432 return 1; 433 } 434 435 static void parse_elf_finish(struct elf_info *info) 436 { 437 release_file(info->hdr, info->size); 438 } 439 440 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_" 441 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_" 442 443 static void handle_modversions(struct module *mod, struct elf_info *info, 444 Elf_Sym *sym, const char *symname) 445 { 446 unsigned int crc; 447 enum export export = export_from_sec(info, sym->st_shndx); 448 449 switch (sym->st_shndx) { 450 case SHN_COMMON: 451 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); 452 break; 453 case SHN_ABS: 454 /* CRC'd symbol */ 455 if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { 456 crc = (unsigned int) sym->st_value; 457 sym_update_crc(symname + strlen(CRC_PFX), mod, crc, 458 export); 459 } 460 break; 461 case SHN_UNDEF: 462 /* undefined symbol */ 463 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && 464 ELF_ST_BIND(sym->st_info) != STB_WEAK) 465 break; 466 /* ignore global offset table */ 467 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) 468 break; 469 /* ignore __this_module, it will be resolved shortly */ 470 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0) 471 break; 472 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */ 473 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER) 474 /* add compatibility with older glibc */ 475 #ifndef STT_SPARC_REGISTER 476 #define STT_SPARC_REGISTER STT_REGISTER 477 #endif 478 if (info->hdr->e_machine == EM_SPARC || 479 info->hdr->e_machine == EM_SPARCV9) { 480 /* Ignore register directives. */ 481 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) 482 break; 483 if (symname[0] == '.') { 484 char *munged = strdup(symname); 485 munged[0] = '_'; 486 munged[1] = toupper(munged[1]); 487 symname = munged; 488 } 489 } 490 #endif 491 492 if (memcmp(symname, MODULE_SYMBOL_PREFIX, 493 strlen(MODULE_SYMBOL_PREFIX)) == 0) 494 mod->unres = alloc_symbol(symname + 495 strlen(MODULE_SYMBOL_PREFIX), 496 ELF_ST_BIND(sym->st_info) == STB_WEAK, 497 mod->unres); 498 break; 499 default: 500 /* All exported symbols */ 501 if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) { 502 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod, 503 export); 504 } 505 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0) 506 mod->has_init = 1; 507 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0) 508 mod->has_cleanup = 1; 509 break; 510 } 511 } 512 513 /** 514 * Parse tag=value strings from .modinfo section 515 **/ 516 static char *next_string(char *string, unsigned long *secsize) 517 { 518 /* Skip non-zero chars */ 519 while (string[0]) { 520 string++; 521 if ((*secsize)-- <= 1) 522 return NULL; 523 } 524 525 /* Skip any zero padding. */ 526 while (!string[0]) { 527 string++; 528 if ((*secsize)-- <= 1) 529 return NULL; 530 } 531 return string; 532 } 533 534 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len, 535 const char *tag, char *info) 536 { 537 char *p; 538 unsigned int taglen = strlen(tag); 539 unsigned long size = modinfo_len; 540 541 if (info) { 542 size -= info - (char *)modinfo; 543 modinfo = next_string(info, &size); 544 } 545 546 for (p = modinfo; p; p = next_string(p, &size)) { 547 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 548 return p + taglen + 1; 549 } 550 return NULL; 551 } 552 553 static char *get_modinfo(void *modinfo, unsigned long modinfo_len, 554 const char *tag) 555 556 { 557 return get_next_modinfo(modinfo, modinfo_len, tag, NULL); 558 } 559 560 /** 561 * Test if string s ends in string sub 562 * return 0 if match 563 **/ 564 static int strrcmp(const char *s, const char *sub) 565 { 566 int slen, sublen; 567 568 if (!s || !sub) 569 return 1; 570 571 slen = strlen(s); 572 sublen = strlen(sub); 573 574 if ((slen == 0) || (sublen == 0)) 575 return 1; 576 577 if (sublen > slen) 578 return 1; 579 580 return memcmp(s + slen - sublen, sub, sublen); 581 } 582 583 /** 584 * Whitelist to allow certain references to pass with no warning. 585 * Pattern 1: 586 * If a module parameter is declared __initdata and permissions=0 587 * then this is legal despite the warning generated. 588 * We cannot see value of permissions here, so just ignore 589 * this pattern. 590 * The pattern is identified by: 591 * tosec = .init.data 592 * fromsec = .data* 593 * atsym =__param* 594 * 595 * Pattern 2: 596 * Many drivers utilise a *driver container with references to 597 * add, remove, probe functions etc. 598 * These functions may often be marked __init and we do not want to 599 * warn here. 600 * the pattern is identified by: 601 * tosec = .init.text | .exit.text | .init.data 602 * fromsec = .data 603 * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one, *_console 604 * 605 * Pattern 3: 606 * Whitelist all references from .pci_fixup* section to .init.text 607 * This is part of the PCI init when built-in 608 * 609 * Pattern 4: 610 * Whitelist all refereces from .text.head to .init.data 611 * Whitelist all refereces from .text.head to .init.text 612 * 613 * Pattern 5: 614 * Some symbols belong to init section but still it is ok to reference 615 * these from non-init sections as these symbols don't have any memory 616 * allocated for them and symbol address and value are same. So even 617 * if init section is freed, its ok to reference those symbols. 618 * For ex. symbols marking the init section boundaries. 619 * This pattern is identified by 620 * refsymname = __init_begin, _sinittext, _einittext 621 * 622 * Pattern 6: 623 * During the early init phase we have references from .init.text to 624 * .text we have an intended section mismatch - do not warn about it. 625 * See kernel_init() in init/main.c 626 * tosec = .init.text 627 * fromsec = .text 628 * atsym = kernel_init 629 * 630 * Pattern 7: 631 * Logos used in drivers/video/logo reside in __initdata but the 632 * funtion that references them are EXPORT_SYMBOL() so cannot be 633 * marker __init. So we whitelist them here. 634 * The pattern is: 635 * tosec = .init.data 636 * fromsec = .text* 637 * refsymname = logo_ 638 * 639 * Pattern 8: 640 * Symbols contained in .paravirtprobe may safely reference .init.text. 641 * The pattern is: 642 * tosec = .init.text 643 * fromsec = .paravirtprobe 644 * 645 * Pattern 9: 646 * Some of functions are common code between boot time and hotplug 647 * time. The bootmem allocater is called only boot time in its 648 * functions. So it's ok to reference. 649 * tosec = .init.text 650 * 651 * Pattern 10: 652 * ia64 has machvec table for each platform. It is mixture of function 653 * pointer of .init.text and .text. 654 * fromsec = .machvec 655 **/ 656 static int secref_whitelist(const char *modname, const char *tosec, 657 const char *fromsec, const char *atsym, 658 const char *refsymname) 659 { 660 int f1 = 1, f2 = 1; 661 const char **s; 662 const char *pat2sym[] = { 663 "driver", 664 "_template", /* scsi uses *_template a lot */ 665 "_sht", /* scsi also used *_sht to some extent */ 666 "_ops", 667 "_probe", 668 "_probe_one", 669 "_console", 670 "apic_es7000", 671 NULL 672 }; 673 674 const char *pat3refsym[] = { 675 "__init_begin", 676 "_sinittext", 677 "_einittext", 678 NULL 679 }; 680 681 const char *pat4sym[] = { 682 "sparse_index_alloc", 683 "zone_wait_table_init", 684 NULL 685 }; 686 687 /* Check for pattern 1 */ 688 if (strcmp(tosec, ".init.data") != 0) 689 f1 = 0; 690 if (strncmp(fromsec, ".data", strlen(".data")) != 0) 691 f1 = 0; 692 if (strncmp(atsym, "__param", strlen("__param")) != 0) 693 f1 = 0; 694 695 if (f1) 696 return f1; 697 698 /* Check for pattern 2 */ 699 if ((strcmp(tosec, ".init.text") != 0) && 700 (strcmp(tosec, ".exit.text") != 0) && 701 (strcmp(tosec, ".init.data") != 0)) 702 f2 = 0; 703 if (strcmp(fromsec, ".data") != 0) 704 f2 = 0; 705 706 for (s = pat2sym; *s; s++) 707 if (strrcmp(atsym, *s) == 0) 708 f1 = 1; 709 if (f1 && f2) 710 return 1; 711 712 /* Check for pattern 3 */ 713 if ((strncmp(fromsec, ".pci_fixup", strlen(".pci_fixup")) == 0) && 714 (strcmp(tosec, ".init.text") == 0)) 715 return 1; 716 717 /* Check for pattern 4 */ 718 if ((strcmp(fromsec, ".text.head") == 0) && 719 ((strcmp(tosec, ".init.data") == 0) || 720 (strcmp(tosec, ".init.text") == 0))) 721 return 1; 722 723 /* Check for pattern 5 */ 724 for (s = pat3refsym; *s; s++) 725 if (strcmp(refsymname, *s) == 0) 726 return 1; 727 728 /* Check for pattern 6 */ 729 if ((strcmp(tosec, ".init.text") == 0) && 730 (strcmp(fromsec, ".text") == 0) && 731 (strcmp(refsymname, "kernel_init") == 0)) 732 return 1; 733 734 /* Check for pattern 7 */ 735 if ((strcmp(tosec, ".init.data") == 0) && 736 (strncmp(fromsec, ".text", strlen(".text")) == 0) && 737 (strncmp(refsymname, "logo_", strlen("logo_")) == 0)) 738 return 1; 739 740 /* Check for pattern 8 */ 741 if ((strcmp(tosec, ".init.text") == 0) && 742 (strcmp(fromsec, ".paravirtprobe") == 0)) 743 return 1; 744 745 /* Check for pattern 9 */ 746 if ((strcmp(tosec, ".init.text") == 0) && 747 (strcmp(fromsec, ".text") == 0)) 748 for (s = pat4sym; *s; s++) 749 if (strcmp(atsym, *s) == 0) 750 return 1; 751 752 /* Check for pattern 10 */ 753 if (strcmp(fromsec, ".machvec") == 0) 754 return 1; 755 756 return 0; 757 } 758 759 /** 760 * Find symbol based on relocation record info. 761 * In some cases the symbol supplied is a valid symbol so 762 * return refsym. If st_name != 0 we assume this is a valid symbol. 763 * In other cases the symbol needs to be looked up in the symbol table 764 * based on section and address. 765 * **/ 766 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr, 767 Elf_Sym *relsym) 768 { 769 Elf_Sym *sym; 770 771 if (relsym->st_name != 0) 772 return relsym; 773 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { 774 if (sym->st_shndx != relsym->st_shndx) 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 (before && 883 secref_whitelist(modname, secname, fromsec, 884 elf->strtab + before->st_name, refsymname)) 885 return; 886 887 if (before && after) { 888 warn("%s - Section mismatch: reference to %s:%s from %s " 889 "between '%s' (at offset 0x%llx) and '%s'\n", 890 modname, secname, refsymname, fromsec, 891 elf->strtab + before->st_name, 892 (long long)r.r_offset, 893 elf->strtab + after->st_name); 894 } else if (before) { 895 warn("%s - Section mismatch: reference to %s:%s from %s " 896 "after '%s' (at offset 0x%llx)\n", 897 modname, secname, refsymname, fromsec, 898 elf->strtab + before->st_name, 899 (long long)r.r_offset); 900 } else if (after) { 901 warn("%s - Section mismatch: reference to %s:%s from %s " 902 "before '%s' (at offset -0x%llx)\n", 903 modname, secname, refsymname, fromsec, 904 elf->strtab + after->st_name, 905 (long long)r.r_offset); 906 } else { 907 warn("%s - Section mismatch: reference to %s:%s from %s " 908 "(offset 0x%llx)\n", 909 modname, secname, fromsec, refsymname, 910 (long long)r.r_offset); 911 } 912 } 913 914 /** 915 * A module includes a number of sections that are discarded 916 * either when loaded or when used as built-in. 917 * For loaded modules all functions marked __init and all data 918 * marked __initdata will be discarded when the module has been intialized. 919 * Likewise for modules used built-in the sections marked __exit 920 * are discarded because __exit marked function are supposed to be called 921 * only when a moduel is unloaded which never happes for built-in modules. 922 * The check_sec_ref() function traverses all relocation records 923 * to find all references to a section that reference a section that will 924 * be discarded and warns about it. 925 **/ 926 static void check_sec_ref(struct module *mod, const char *modname, 927 struct elf_info *elf, 928 int section(const char*), 929 int section_ref_ok(const char *)) 930 { 931 int i; 932 Elf_Sym *sym; 933 Elf_Ehdr *hdr = elf->hdr; 934 Elf_Shdr *sechdrs = elf->sechdrs; 935 const char *secstrings = (void *)hdr + 936 sechdrs[hdr->e_shstrndx].sh_offset; 937 938 /* Walk through all sections */ 939 for (i = 0; i < hdr->e_shnum; i++) { 940 const char *name = secstrings + sechdrs[i].sh_name; 941 const char *secname; 942 Elf_Rela r; 943 unsigned int r_sym; 944 /* We want to process only relocation sections and not .init */ 945 if (sechdrs[i].sh_type == SHT_RELA) { 946 Elf_Rela *rela; 947 Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset; 948 Elf_Rela *stop = (void*)start + sechdrs[i].sh_size; 949 name += strlen(".rela"); 950 if (section_ref_ok(name)) 951 continue; 952 953 for (rela = start; rela < stop; rela++) { 954 r.r_offset = TO_NATIVE(rela->r_offset); 955 #if KERNEL_ELFCLASS == ELFCLASS64 956 if (hdr->e_machine == EM_MIPS) { 957 r_sym = ELF64_MIPS_R_SYM(rela->r_info); 958 r_sym = TO_NATIVE(r_sym); 959 } else { 960 r.r_info = TO_NATIVE(rela->r_info); 961 r_sym = ELF_R_SYM(r.r_info); 962 } 963 #else 964 r.r_info = TO_NATIVE(rela->r_info); 965 r_sym = ELF_R_SYM(r.r_info); 966 #endif 967 r.r_addend = TO_NATIVE(rela->r_addend); 968 sym = elf->symtab_start + r_sym; 969 /* Skip special sections */ 970 if (sym->st_shndx >= SHN_LORESERVE) 971 continue; 972 973 secname = secstrings + 974 sechdrs[sym->st_shndx].sh_name; 975 if (section(secname)) 976 warn_sec_mismatch(modname, name, 977 elf, sym, r); 978 } 979 } else if (sechdrs[i].sh_type == SHT_REL) { 980 Elf_Rel *rel; 981 Elf_Rel *start = (void *)hdr + sechdrs[i].sh_offset; 982 Elf_Rel *stop = (void*)start + sechdrs[i].sh_size; 983 name += strlen(".rel"); 984 if (section_ref_ok(name)) 985 continue; 986 987 for (rel = start; rel < stop; rel++) { 988 r.r_offset = TO_NATIVE(rel->r_offset); 989 #if KERNEL_ELFCLASS == ELFCLASS64 990 if (hdr->e_machine == EM_MIPS) { 991 r_sym = ELF64_MIPS_R_SYM(rel->r_info); 992 r_sym = TO_NATIVE(r_sym); 993 } else { 994 r.r_info = TO_NATIVE(rel->r_info); 995 r_sym = ELF_R_SYM(r.r_info); 996 } 997 #else 998 r.r_info = TO_NATIVE(rel->r_info); 999 r_sym = ELF_R_SYM(r.r_info); 1000 #endif 1001 r.r_addend = 0; 1002 sym = elf->symtab_start + r_sym; 1003 /* Skip special sections */ 1004 if (sym->st_shndx >= SHN_LORESERVE) 1005 continue; 1006 1007 secname = secstrings + 1008 sechdrs[sym->st_shndx].sh_name; 1009 if (section(secname)) 1010 warn_sec_mismatch(modname, name, 1011 elf, sym, r); 1012 } 1013 } 1014 } 1015 } 1016 1017 /** 1018 * Functions used only during module init is marked __init and is stored in 1019 * a .init.text section. Likewise data is marked __initdata and stored in 1020 * a .init.data section. 1021 * If this section is one of these sections return 1 1022 * See include/linux/init.h for the details 1023 **/ 1024 static int init_section(const char *name) 1025 { 1026 if (strcmp(name, ".init") == 0) 1027 return 1; 1028 if (strncmp(name, ".init.", strlen(".init.")) == 0) 1029 return 1; 1030 return 0; 1031 } 1032 1033 /** 1034 * Identify sections from which references to a .init section is OK. 1035 * 1036 * Unfortunately references to read only data that referenced .init 1037 * sections had to be excluded. Almost all of these are false 1038 * positives, they are created by gcc. The downside of excluding rodata 1039 * is that there really are some user references from rodata to 1040 * init code, e.g. drivers/video/vgacon.c: 1041 * 1042 * const struct consw vga_con = { 1043 * con_startup: vgacon_startup, 1044 * 1045 * where vgacon_startup is __init. If you want to wade through the false 1046 * positives, take out the check for rodata. 1047 **/ 1048 static int init_section_ref_ok(const char *name) 1049 { 1050 const char **s; 1051 /* Absolute section names */ 1052 const char *namelist1[] = { 1053 ".init", 1054 ".opd", /* see comment [OPD] at exit_section_ref_ok() */ 1055 ".toc1", /* used by ppc64 */ 1056 ".stab", 1057 ".data.rel.ro", /* used by parisc64 */ 1058 ".parainstructions", 1059 ".text.lock", 1060 "__bug_table", /* used by powerpc for BUG() */ 1061 ".pci_fixup_header", 1062 ".pci_fixup_final", 1063 ".pdr", 1064 "__param", 1065 "__ex_table", 1066 ".fixup", 1067 ".smp_locks", 1068 ".plt", /* seen on ARCH=um build on x86_64. Harmless */ 1069 "__ftr_fixup", /* powerpc cpu feature fixup */ 1070 "__fw_ftr_fixup", /* powerpc firmware feature fixup */ 1071 NULL 1072 }; 1073 /* Start of section names */ 1074 const char *namelist2[] = { 1075 ".init.", 1076 ".altinstructions", 1077 ".eh_frame", 1078 ".debug", 1079 ".parainstructions", 1080 ".rodata", 1081 NULL 1082 }; 1083 /* part of section name */ 1084 const char *namelist3 [] = { 1085 ".unwind", /* sample: IA_64.unwind.init.text */ 1086 NULL 1087 }; 1088 1089 for (s = namelist1; *s; s++) 1090 if (strcmp(*s, name) == 0) 1091 return 1; 1092 for (s = namelist2; *s; s++) 1093 if (strncmp(*s, name, strlen(*s)) == 0) 1094 return 1; 1095 for (s = namelist3; *s; s++) 1096 if (strstr(name, *s) != NULL) 1097 return 1; 1098 if (strrcmp(name, ".init") == 0) 1099 return 1; 1100 return 0; 1101 } 1102 1103 /* 1104 * Functions used only during module exit is marked __exit and is stored in 1105 * a .exit.text section. Likewise data is marked __exitdata and stored in 1106 * a .exit.data section. 1107 * If this section is one of these sections return 1 1108 * See include/linux/init.h for the details 1109 **/ 1110 static int exit_section(const char *name) 1111 { 1112 if (strcmp(name, ".exit.text") == 0) 1113 return 1; 1114 if (strcmp(name, ".exit.data") == 0) 1115 return 1; 1116 return 0; 1117 1118 } 1119 1120 /* 1121 * Identify sections from which references to a .exit section is OK. 1122 * 1123 * [OPD] Keith Ownes <kaos@sgi.com> commented: 1124 * For our future {in}sanity, add a comment that this is the ppc .opd 1125 * section, not the ia64 .opd section. 1126 * ia64 .opd should not point to discarded sections. 1127 * [.rodata] like for .init.text we ignore .rodata references -same reason 1128 **/ 1129 static int exit_section_ref_ok(const char *name) 1130 { 1131 const char **s; 1132 /* Absolute section names */ 1133 const char *namelist1[] = { 1134 ".exit.text", 1135 ".exit.data", 1136 ".init.text", 1137 ".rodata", 1138 ".opd", /* See comment [OPD] */ 1139 ".toc1", /* used by ppc64 */ 1140 ".altinstructions", 1141 ".pdr", 1142 "__bug_table", /* used by powerpc for BUG() */ 1143 ".exitcall.exit", 1144 ".eh_frame", 1145 ".parainstructions", 1146 ".stab", 1147 "__ex_table", 1148 ".fixup", 1149 ".smp_locks", 1150 ".plt", /* seen on ARCH=um build on x86_64. Harmless */ 1151 NULL 1152 }; 1153 /* Start of section names */ 1154 const char *namelist2[] = { 1155 ".debug", 1156 NULL 1157 }; 1158 /* part of section name */ 1159 const char *namelist3 [] = { 1160 ".unwind", /* Sample: IA_64.unwind.exit.text */ 1161 NULL 1162 }; 1163 1164 for (s = namelist1; *s; s++) 1165 if (strcmp(*s, name) == 0) 1166 return 1; 1167 for (s = namelist2; *s; s++) 1168 if (strncmp(*s, name, strlen(*s)) == 0) 1169 return 1; 1170 for (s = namelist3; *s; s++) 1171 if (strstr(name, *s) != NULL) 1172 return 1; 1173 return 0; 1174 } 1175 1176 static void read_symbols(char *modname) 1177 { 1178 const char *symname; 1179 char *version; 1180 char *license; 1181 struct module *mod; 1182 struct elf_info info = { }; 1183 Elf_Sym *sym; 1184 1185 if (!parse_elf(&info, modname)) 1186 return; 1187 1188 mod = new_module(modname); 1189 1190 /* When there's no vmlinux, don't print warnings about 1191 * unresolved symbols (since there'll be too many ;) */ 1192 if (is_vmlinux(modname)) { 1193 have_vmlinux = 1; 1194 mod->skip = 1; 1195 } 1196 1197 license = get_modinfo(info.modinfo, info.modinfo_len, "license"); 1198 while (license) { 1199 if (license_is_gpl_compatible(license)) 1200 mod->gpl_compatible = 1; 1201 else { 1202 mod->gpl_compatible = 0; 1203 break; 1204 } 1205 license = get_next_modinfo(info.modinfo, info.modinfo_len, 1206 "license", license); 1207 } 1208 1209 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { 1210 symname = info.strtab + sym->st_name; 1211 1212 handle_modversions(mod, &info, sym, symname); 1213 handle_moddevtable(mod, &info, sym, symname); 1214 } 1215 check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok); 1216 check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok); 1217 1218 version = get_modinfo(info.modinfo, info.modinfo_len, "version"); 1219 if (version) 1220 maybe_frob_rcs_version(modname, version, info.modinfo, 1221 version - (char *)info.hdr); 1222 if (version || (all_versions && !is_vmlinux(modname))) 1223 get_src_version(modname, mod->srcversion, 1224 sizeof(mod->srcversion)-1); 1225 1226 parse_elf_finish(&info); 1227 1228 /* Our trick to get versioning for struct_module - it's 1229 * never passed as an argument to an exported function, so 1230 * the automatic versioning doesn't pick it up, but it's really 1231 * important anyhow */ 1232 if (modversions) 1233 mod->unres = alloc_symbol("struct_module", 0, mod->unres); 1234 } 1235 1236 #define SZ 500 1237 1238 /* We first write the generated file into memory using the 1239 * following helper, then compare to the file on disk and 1240 * only update the later if anything changed */ 1241 1242 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, 1243 const char *fmt, ...) 1244 { 1245 char tmp[SZ]; 1246 int len; 1247 va_list ap; 1248 1249 va_start(ap, fmt); 1250 len = vsnprintf(tmp, SZ, fmt, ap); 1251 buf_write(buf, tmp, len); 1252 va_end(ap); 1253 } 1254 1255 void buf_write(struct buffer *buf, const char *s, int len) 1256 { 1257 if (buf->size - buf->pos < len) { 1258 buf->size += len + SZ; 1259 buf->p = realloc(buf->p, buf->size); 1260 } 1261 strncpy(buf->p + buf->pos, s, len); 1262 buf->pos += len; 1263 } 1264 1265 static void check_for_gpl_usage(enum export exp, const char *m, const char *s) 1266 { 1267 const char *e = is_vmlinux(m) ?"":".ko"; 1268 1269 switch (exp) { 1270 case export_gpl: 1271 fatal("modpost: GPL-incompatible module %s%s " 1272 "uses GPL-only symbol '%s'\n", m, e, s); 1273 break; 1274 case export_unused_gpl: 1275 fatal("modpost: GPL-incompatible module %s%s " 1276 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); 1277 break; 1278 case export_gpl_future: 1279 warn("modpost: GPL-incompatible module %s%s " 1280 "uses future GPL-only symbol '%s'\n", m, e, s); 1281 break; 1282 case export_plain: 1283 case export_unused: 1284 case export_unknown: 1285 /* ignore */ 1286 break; 1287 } 1288 } 1289 1290 static void check_for_unused(enum export exp, const char* m, const char* s) 1291 { 1292 const char *e = is_vmlinux(m) ?"":".ko"; 1293 1294 switch (exp) { 1295 case export_unused: 1296 case export_unused_gpl: 1297 warn("modpost: module %s%s " 1298 "uses symbol '%s' marked UNUSED\n", m, e, s); 1299 break; 1300 default: 1301 /* ignore */ 1302 break; 1303 } 1304 } 1305 1306 static void check_exports(struct module *mod) 1307 { 1308 struct symbol *s, *exp; 1309 1310 for (s = mod->unres; s; s = s->next) { 1311 const char *basename; 1312 exp = find_symbol(s->name); 1313 if (!exp || exp->module == mod) 1314 continue; 1315 basename = strrchr(mod->name, '/'); 1316 if (basename) 1317 basename++; 1318 else 1319 basename = mod->name; 1320 if (!mod->gpl_compatible) 1321 check_for_gpl_usage(exp->export, basename, exp->name); 1322 check_for_unused(exp->export, basename, exp->name); 1323 } 1324 } 1325 1326 /** 1327 * Header for the generated file 1328 **/ 1329 static void add_header(struct buffer *b, struct module *mod) 1330 { 1331 buf_printf(b, "#include <linux/module.h>\n"); 1332 buf_printf(b, "#include <linux/vermagic.h>\n"); 1333 buf_printf(b, "#include <linux/compiler.h>\n"); 1334 buf_printf(b, "\n"); 1335 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); 1336 buf_printf(b, "\n"); 1337 buf_printf(b, "struct module __this_module\n"); 1338 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); 1339 buf_printf(b, " .name = KBUILD_MODNAME,\n"); 1340 if (mod->has_init) 1341 buf_printf(b, " .init = init_module,\n"); 1342 if (mod->has_cleanup) 1343 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" 1344 " .exit = cleanup_module,\n" 1345 "#endif\n"); 1346 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n"); 1347 buf_printf(b, "};\n"); 1348 } 1349 1350 /** 1351 * Record CRCs for unresolved symbols 1352 **/ 1353 static int add_versions(struct buffer *b, struct module *mod) 1354 { 1355 struct symbol *s, *exp; 1356 int err = 0; 1357 1358 for (s = mod->unres; s; s = s->next) { 1359 exp = find_symbol(s->name); 1360 if (!exp || exp->module == mod) { 1361 if (have_vmlinux && !s->weak) { 1362 if (warn_unresolved) { 1363 warn("\"%s\" [%s.ko] undefined!\n", 1364 s->name, mod->name); 1365 } else { 1366 merror("\"%s\" [%s.ko] undefined!\n", 1367 s->name, mod->name); 1368 err = 1; 1369 } 1370 } 1371 continue; 1372 } 1373 s->module = exp->module; 1374 s->crc_valid = exp->crc_valid; 1375 s->crc = exp->crc; 1376 } 1377 1378 if (!modversions) 1379 return err; 1380 1381 buf_printf(b, "\n"); 1382 buf_printf(b, "static const struct modversion_info ____versions[]\n"); 1383 buf_printf(b, "__attribute_used__\n"); 1384 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); 1385 1386 for (s = mod->unres; s; s = s->next) { 1387 if (!s->module) { 1388 continue; 1389 } 1390 if (!s->crc_valid) { 1391 warn("\"%s\" [%s.ko] has no CRC!\n", 1392 s->name, mod->name); 1393 continue; 1394 } 1395 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); 1396 } 1397 1398 buf_printf(b, "};\n"); 1399 1400 return err; 1401 } 1402 1403 static void add_depends(struct buffer *b, struct module *mod, 1404 struct module *modules) 1405 { 1406 struct symbol *s; 1407 struct module *m; 1408 int first = 1; 1409 1410 for (m = modules; m; m = m->next) { 1411 m->seen = is_vmlinux(m->name); 1412 } 1413 1414 buf_printf(b, "\n"); 1415 buf_printf(b, "static const char __module_depends[]\n"); 1416 buf_printf(b, "__attribute_used__\n"); 1417 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); 1418 buf_printf(b, "\"depends="); 1419 for (s = mod->unres; s; s = s->next) { 1420 const char *p; 1421 if (!s->module) 1422 continue; 1423 1424 if (s->module->seen) 1425 continue; 1426 1427 s->module->seen = 1; 1428 if ((p = strrchr(s->module->name, '/')) != NULL) 1429 p++; 1430 else 1431 p = s->module->name; 1432 buf_printf(b, "%s%s", first ? "" : ",", p); 1433 first = 0; 1434 } 1435 buf_printf(b, "\";\n"); 1436 } 1437 1438 static void add_srcversion(struct buffer *b, struct module *mod) 1439 { 1440 if (mod->srcversion[0]) { 1441 buf_printf(b, "\n"); 1442 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", 1443 mod->srcversion); 1444 } 1445 } 1446 1447 static void write_if_changed(struct buffer *b, const char *fname) 1448 { 1449 char *tmp; 1450 FILE *file; 1451 struct stat st; 1452 1453 file = fopen(fname, "r"); 1454 if (!file) 1455 goto write; 1456 1457 if (fstat(fileno(file), &st) < 0) 1458 goto close_write; 1459 1460 if (st.st_size != b->pos) 1461 goto close_write; 1462 1463 tmp = NOFAIL(malloc(b->pos)); 1464 if (fread(tmp, 1, b->pos, file) != b->pos) 1465 goto free_write; 1466 1467 if (memcmp(tmp, b->p, b->pos) != 0) 1468 goto free_write; 1469 1470 free(tmp); 1471 fclose(file); 1472 return; 1473 1474 free_write: 1475 free(tmp); 1476 close_write: 1477 fclose(file); 1478 write: 1479 file = fopen(fname, "w"); 1480 if (!file) { 1481 perror(fname); 1482 exit(1); 1483 } 1484 if (fwrite(b->p, 1, b->pos, file) != b->pos) { 1485 perror(fname); 1486 exit(1); 1487 } 1488 fclose(file); 1489 } 1490 1491 /* parse Module.symvers file. line format: 1492 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] 1493 **/ 1494 static void read_dump(const char *fname, unsigned int kernel) 1495 { 1496 unsigned long size, pos = 0; 1497 void *file = grab_file(fname, &size); 1498 char *line; 1499 1500 if (!file) 1501 /* No symbol versions, silently ignore */ 1502 return; 1503 1504 while ((line = get_next_line(&pos, file, size))) { 1505 char *symname, *modname, *d, *export, *end; 1506 unsigned int crc; 1507 struct module *mod; 1508 struct symbol *s; 1509 1510 if (!(symname = strchr(line, '\t'))) 1511 goto fail; 1512 *symname++ = '\0'; 1513 if (!(modname = strchr(symname, '\t'))) 1514 goto fail; 1515 *modname++ = '\0'; 1516 if ((export = strchr(modname, '\t')) != NULL) 1517 *export++ = '\0'; 1518 if (export && ((end = strchr(export, '\t')) != NULL)) 1519 *end = '\0'; 1520 crc = strtoul(line, &d, 16); 1521 if (*symname == '\0' || *modname == '\0' || *d != '\0') 1522 goto fail; 1523 1524 if (!(mod = find_module(modname))) { 1525 if (is_vmlinux(modname)) { 1526 have_vmlinux = 1; 1527 } 1528 mod = new_module(NOFAIL(strdup(modname))); 1529 mod->skip = 1; 1530 } 1531 s = sym_add_exported(symname, mod, export_no(export)); 1532 s->kernel = kernel; 1533 s->preloaded = 1; 1534 sym_update_crc(symname, mod, crc, export_no(export)); 1535 } 1536 return; 1537 fail: 1538 fatal("parse error in symbol dump file\n"); 1539 } 1540 1541 /* For normal builds always dump all symbols. 1542 * For external modules only dump symbols 1543 * that are not read from kernel Module.symvers. 1544 **/ 1545 static int dump_sym(struct symbol *sym) 1546 { 1547 if (!external_module) 1548 return 1; 1549 if (sym->vmlinux || sym->kernel) 1550 return 0; 1551 return 1; 1552 } 1553 1554 static void write_dump(const char *fname) 1555 { 1556 struct buffer buf = { }; 1557 struct symbol *symbol; 1558 int n; 1559 1560 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { 1561 symbol = symbolhash[n]; 1562 while (symbol) { 1563 if (dump_sym(symbol)) 1564 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", 1565 symbol->crc, symbol->name, 1566 symbol->module->name, 1567 export_str(symbol->export)); 1568 symbol = symbol->next; 1569 } 1570 } 1571 write_if_changed(&buf, fname); 1572 } 1573 1574 int main(int argc, char **argv) 1575 { 1576 struct module *mod; 1577 struct buffer buf = { }; 1578 char fname[SZ]; 1579 char *kernel_read = NULL, *module_read = NULL; 1580 char *dump_write = NULL; 1581 int opt; 1582 int err; 1583 1584 while ((opt = getopt(argc, argv, "i:I:mo:aw")) != -1) { 1585 switch(opt) { 1586 case 'i': 1587 kernel_read = optarg; 1588 break; 1589 case 'I': 1590 module_read = optarg; 1591 external_module = 1; 1592 break; 1593 case 'm': 1594 modversions = 1; 1595 break; 1596 case 'o': 1597 dump_write = optarg; 1598 break; 1599 case 'a': 1600 all_versions = 1; 1601 break; 1602 case 'w': 1603 warn_unresolved = 1; 1604 break; 1605 default: 1606 exit(1); 1607 } 1608 } 1609 1610 if (kernel_read) 1611 read_dump(kernel_read, 1); 1612 if (module_read) 1613 read_dump(module_read, 0); 1614 1615 while (optind < argc) { 1616 read_symbols(argv[optind++]); 1617 } 1618 1619 for (mod = modules; mod; mod = mod->next) { 1620 if (mod->skip) 1621 continue; 1622 check_exports(mod); 1623 } 1624 1625 err = 0; 1626 1627 for (mod = modules; mod; mod = mod->next) { 1628 if (mod->skip) 1629 continue; 1630 1631 buf.pos = 0; 1632 1633 add_header(&buf, mod); 1634 err |= add_versions(&buf, mod); 1635 add_depends(&buf, mod, modules); 1636 add_moddevtable(&buf, mod); 1637 add_srcversion(&buf, mod); 1638 1639 sprintf(fname, "%s.mod.c", mod->name); 1640 write_if_changed(&buf, fname); 1641 } 1642 1643 if (dump_write) 1644 write_dump(dump_write); 1645 1646 return err; 1647 } 1648