scripts/mod/modpost.c

   1 /* Postprocess module symbol versions
   2  *
   3  * Copyright 2003       Kai Germaschewski
   4  * Copyright 2002-2004  Rusty Russell, IBM Corporation
   5  *
   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
  17 /* Are we using CONFIG_MODVERSIONS? */
  18 int modversions = 0;
  19 /* Warn about undefined symbols? (do so if we have vmlinux) */
  20 int have_vmlinux = 0;
  21 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
  22 static int all_versions = 0;
  23
  24 void
  25 fatal(const char *fmt, ...)
  26 {
  27         va_list arglist;
  28
  29         fprintf(stderr, "FATAL: ");
  30
  31         va_start(arglist, fmt);
  32         vfprintf(stderr, fmt, arglist);
  33         va_end(arglist);
  34
  35         exit(1);
  36 }
  37
  38 void
  39 warn(const char *fmt, ...)
  40 {
  41         va_list arglist;
  42
  43         fprintf(stderr, "WARNING: ");
  44
  45         va_start(arglist, fmt);
  46         vfprintf(stderr, fmt, arglist);
  47         va_end(arglist);
  48 }
  49
  50 void *do_nofail(void *ptr, const char *expr)
  51 {
  52         if (!ptr) {
  53                 fatal("modpost: Memory allocation failure: %s.\n", expr);
  54         }
  55         return ptr;
  56 }
  57
  58 /* A list of all modules we processed */
  59
  60 static struct module *modules;
  61
  62 struct module *
  63 find_module(char *modname)
  64 {
  65         struct module *mod;
  66
  67         for (mod = modules; mod; mod = mod->next)
  68                 if (strcmp(mod->name, modname) == 0)
  69                         break;
  70         return mod;
  71 }
  72
  73 struct module *
  74 new_module(char *modname)
  75 {
  76         struct module *mod;
  77         char *p, *s;
  78
  79         mod = NOFAIL(malloc(sizeof(*mod)));
  80         memset(mod, 0, sizeof(*mod));
  81         p = NOFAIL(strdup(modname));
  82
  83         /* strip trailing .o */
  84         if ((s = strrchr(p, '.')) != NULL)
  85                 if (strcmp(s, ".o") == 0)
  86                         *s = '\0';
  87
  88         /* add to list */
  89         mod->name = p;
  90         mod->next = modules;
  91         modules = mod;
  92
  93         return mod;
  94 }
  95
  96 /* A hash of all exported symbols,
  97  * struct symbol is also used for lists of unresolved symbols */
  98
  99 #define SYMBOL_HASH_SIZE 1024
 100
 101 struct symbol {
 102         struct symbol *next;
 103         struct module *module;
 104         unsigned int crc;
 105         int crc_valid;
 106         unsigned int weak:1;
 107         char name[0];
 108 };
 109
 110 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
 111
 112 /* This is based on the hash agorithm from gdbm, via tdb */
 113 static inline unsigned int tdb_hash(const char *name)
 114 {
 115         unsigned value; /* Used to compute the hash value.  */
 116         unsigned   i;   /* Used to cycle through random values. */
 117
 118         /* Set the initial value from the key size. */
 119         for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++)
 120                 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
 121
 122         return (1103515243 * value + 12345);
 123 }
 124
 125 /* Allocate a new symbols for use in the hash of exported symbols or
 126  * the list of unresolved symbols per module */
 127
 128 struct symbol *
 129 alloc_symbol(const char *name, unsigned int weak, struct symbol *next)
 130 {
 131         struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
 132
 133         memset(s, 0, sizeof(*s));
 134         strcpy(s->name, name);
 135         s->weak = weak;
 136         s->next = next;
 137         return s;
 138 }
 139
 140 /* For the hash of exported symbols */
 141
 142 void
 143 new_symbol(const char *name, struct module *module, unsigned int *crc)
 144 {
 145         unsigned int hash;
 146         struct symbol *new;
 147
 148         hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
 149         new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
 150         new->module = module;
 151         if (crc) {
 152                 new->crc = *crc;
 153                 new->crc_valid = 1;
 154         }
 155 }
 156
 157 struct symbol *
 158 find_symbol(const char *name)
 159 {
 160         struct symbol *s;
 161
 162         /* For our purposes, .foo matches foo.  PPC64 needs this. */
 163         if (name[0] == '.')
 164                 name++;
 165
 166         for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s=s->next) {
 167                 if (strcmp(s->name, name) == 0)
 168                         return s;
 169         }
 170         return NULL;
 171 }
 172
 173 /* Add an exported symbol - it may have already been added without a
 174  * CRC, in this case just update the CRC */
 175 void
 176 add_exported_symbol(const char *name, struct module *module, unsigned int *crc)
 177 {
 178         struct symbol *s = find_symbol(name);
 179
 180         if (!s) {
 181                 new_symbol(name, module, crc);
 182                 return;
 183         }
 184         if (crc) {
 185                 s->crc = *crc;
 186                 s->crc_valid = 1;
 187         }
 188 }
 189
 190 void *
 191 grab_file(const char *filename, unsigned long *size)
 192 {
 193         struct stat st;
 194         void *map;
 195         int fd;
 196
 197         fd = open(filename, O_RDONLY);
 198         if (fd < 0 || fstat(fd, &st) != 0)
 199                 return NULL;
 200
 201         *size = st.st_size;
 202         map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
 203         close(fd);
 204
 205         if (map == MAP_FAILED)
 206                 return NULL;
 207         return map;
 208 }
 209
 210 /*
 211    Return a copy of the next line in a mmap'ed file.
 212    spaces in the beginning of the line is trimmed away.
 213    Return a pointer to a static buffer.
 214 */
 215 char*
 216 get_next_line(unsigned long *pos, void *file, unsigned long size)
 217 {
 218         static char line[4096];
 219         int skip = 1;
 220         size_t len = 0;
 221         signed char *p = (signed char *)file + *pos;
 222         char *s = line;
 223
 224         for (; *pos < size ; (*pos)++)
 225         {
 226                 if (skip && isspace(*p)) {
 227                         p++;
 228                         continue;
 229                 }
 230                 skip = 0;
 231                 if (*p != '\n' && (*pos < size)) {
 232                         len++;
 233                         *s++ = *p++;
 234                         if (len > 4095)
 235                                 break; /* Too long, stop */
 236                 } else {
 237                         /* End of string */
 238                         *s = '\0';
 239                         return line;
 240                 }
 241         }
 242         /* End of buffer */
 243         return NULL;
 244 }
 245
 246 void
 247 release_file(void *file, unsigned long size)
 248 {
 249         munmap(file, size);
 250 }
 251
 252 void
 253 parse_elf(struct elf_info *info, const char *filename)
 254 {
 255         unsigned int i;
 256         Elf_Ehdr *hdr = info->hdr;
 257         Elf_Shdr *sechdrs;
 258         Elf_Sym  *sym;
 259
 260         hdr = grab_file(filename, &info->size);
 261         if (!hdr) {
 262                 perror(filename);
 263                 abort();
 264         }
 265         info->hdr = hdr;
 266         if (info->size < sizeof(*hdr))
 267                 goto truncated;
 268
 269         /* Fix endianness in ELF header */
 270         hdr->e_shoff    = TO_NATIVE(hdr->e_shoff);
 271         hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
 272         hdr->e_shnum    = TO_NATIVE(hdr->e_shnum);
 273         hdr->e_machine  = TO_NATIVE(hdr->e_machine);
 274         sechdrs = (void *)hdr + hdr->e_shoff;
 275         info->sechdrs = sechdrs;
 276
 277         /* Fix endianness in section headers */
 278         for (i = 0; i < hdr->e_shnum; i++) {
 279                 sechdrs[i].sh_type   = TO_NATIVE(sechdrs[i].sh_type);
 280                 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
 281                 sechdrs[i].sh_size   = TO_NATIVE(sechdrs[i].sh_size);
 282                 sechdrs[i].sh_link   = TO_NATIVE(sechdrs[i].sh_link);
 283                 sechdrs[i].sh_name   = TO_NATIVE(sechdrs[i].sh_name);
 284         }
 285         /* Find symbol table. */
 286         for (i = 1; i < hdr->e_shnum; i++) {
 287                 const char *secstrings
 288                         = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
 289
 290                 if (sechdrs[i].sh_offset > info->size)
 291                         goto truncated;
 292                 if (strcmp(secstrings+sechdrs[i].sh_name, ".modinfo") == 0) {
 293                         info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
 294                         info->modinfo_len = sechdrs[i].sh_size;
 295                 }
 296                 if (sechdrs[i].sh_type != SHT_SYMTAB)
 297                         continue;
 298
 299                 info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
 300                 info->symtab_stop  = (void *)hdr + sechdrs[i].sh_offset
 301                                                  + sechdrs[i].sh_size;
 302                 info->strtab       = (void *)hdr +
 303                                      sechdrs[sechdrs[i].sh_link].sh_offset;
 304         }
 305         if (!info->symtab_start) {
 306                 fprintf(stderr, "modpost: %s no symtab?\n", filename);
 307                 abort();
 308         }
 309         /* Fix endianness in symbols */
 310         for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
 311                 sym->st_shndx = TO_NATIVE(sym->st_shndx);
 312                 sym->st_name  = TO_NATIVE(sym->st_name);
 313                 sym->st_value = TO_NATIVE(sym->st_value);
 314                 sym->st_size  = TO_NATIVE(sym->st_size);
 315         }
 316         return;
 317
 318  truncated:
 319         fprintf(stderr, "modpost: %s is truncated.\n", filename);
 320         abort();
 321 }
 322
 323 void
 324 parse_elf_finish(struct elf_info *info)
 325 {
 326         release_file(info->hdr, info->size);
 327 }
 328
 329 #define CRC_PFX     "__crc_"
 330 #define KSYMTAB_PFX "__ksymtab_"
 331
 332 void
 333 handle_modversions(struct module *mod, struct elf_info *info,
 334                    Elf_Sym *sym, const char *symname)
 335 {
 336         unsigned int crc;
 337
 338         switch (sym->st_shndx) {
 339         case SHN_COMMON:
 340                 fprintf(stderr, "*** Warning: \"%s\" [%s] is COMMON symbol\n",
 341                         symname, mod->name);
 342                 break;
 343         case SHN_ABS:
 344                 /* CRC'd symbol */
 345                 if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
 346                         crc = (unsigned int) sym->st_value;
 347                         add_exported_symbol(symname + strlen(CRC_PFX),
 348                                             mod, &crc);
 349                 }
 350                 break;
 351         case SHN_UNDEF:
 352                 /* undefined symbol */
 353                 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
 354                     ELF_ST_BIND(sym->st_info) != STB_WEAK)
 355                         break;
 356                 /* ignore global offset table */
 357                 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
 358                         break;
 359                 /* ignore __this_module, it will be resolved shortly */
 360                 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
 361                         break;
 362 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
 363 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
 364 /* add compatibility with older glibc */
 365 #ifndef STT_SPARC_REGISTER
 366 #define STT_SPARC_REGISTER STT_REGISTER
 367 #endif
 368                 if (info->hdr->e_machine == EM_SPARC ||
 369                     info->hdr->e_machine == EM_SPARCV9) {
 370                         /* Ignore register directives. */
 371                         if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
 372                                 break;
 373                         if (symname[0] == '.') {
 374                                 char *munged = strdup(symname);
 375                                 munged[0] = '_';
 376                                 munged[1] = toupper(munged[1]);
 377                                 symname = munged;
 378                         }
 379                 }
 380 #endif
 381
 382                 if (memcmp(symname, MODULE_SYMBOL_PREFIX,
 383                            strlen(MODULE_SYMBOL_PREFIX)) == 0)
 384                         mod->unres = alloc_symbol(symname +
 385                                                   strlen(MODULE_SYMBOL_PREFIX),
 386                                                   ELF_ST_BIND(sym->st_info) == STB_WEAK,
 387                                                   mod->unres);
 388                 break;
 389         default:
 390                 /* All exported symbols */
 391                 if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
 392                         add_exported_symbol(symname + strlen(KSYMTAB_PFX),
 393                                             mod, NULL);
 394                 }
 395                 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
 396                         mod->has_init = 1;
 397                 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
 398                         mod->has_cleanup = 1;
 399                 break;
 400         }
 401 }
 402
 403 int
 404 is_vmlinux(const char *modname)
 405 {
 406         const char *myname;
 407
 408         if ((myname = strrchr(modname, '/')))
 409                 myname++;
 410         else
 411                 myname = modname;
 412
 413         return strcmp(myname, "vmlinux") == 0;
 414 }
 415
 416 /* Parse tag=value strings from .modinfo section */
 417 static char *next_string(char *string, unsigned long *secsize)
 418 {
 419         /* Skip non-zero chars */
 420         while (string[0]) {
 421                 string++;
 422                 if ((*secsize)-- <= 1)
 423                         return NULL;
 424         }
 425
 426         /* Skip any zero padding. */
 427         while (!string[0]) {
 428                 string++;
 429                 if ((*secsize)-- <= 1)
 430                         return NULL;
 431         }
 432         return string;
 433 }
 434
 435 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
 436                          const char *tag)
 437 {
 438         char *p;
 439         unsigned int taglen = strlen(tag);
 440         unsigned long size = modinfo_len;
 441
 442         for (p = modinfo; p; p = next_string(p, &size)) {
 443                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
 444                         return p + taglen + 1;
 445         }
 446         return NULL;
 447 }
 448
 449 void
 450 read_symbols(char *modname)
 451 {
 452         const char *symname;
 453         char *version;
 454         struct module *mod;
 455         struct elf_info info = { };
 456         Elf_Sym *sym;
 457
 458         parse_elf(&info, modname);
 459
 460         mod = new_module(modname);
 461
 462         /* When there's no vmlinux, don't print warnings about
 463          * unresolved symbols (since there'll be too many ;) */
 464         if (is_vmlinux(modname)) {
 465                 unsigned int fake_crc = 0;
 466                 have_vmlinux = 1;
 467                 add_exported_symbol("struct_module", mod, &fake_crc);
 468                 mod->skip = 1;
 469         }
 470
 471         for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
 472                 symname = info.strtab + sym->st_name;
 473
 474                 handle_modversions(mod, &info, sym, symname);
 475                 handle_moddevtable(mod, &info, sym, symname);
 476         }
 477
 478         version = get_modinfo(info.modinfo, info.modinfo_len, "version");
 479         if (version)
 480                 maybe_frob_rcs_version(modname, version, info.modinfo,
 481                                        version - (char *)info.hdr);
 482         if (version || (all_versions && !is_vmlinux(modname)))
 483                 get_src_version(modname, mod->srcversion,
 484                                 sizeof(mod->srcversion)-1);
 485
 486         parse_elf_finish(&info);
 487
 488         /* Our trick to get versioning for struct_module - it's
 489          * never passed as an argument to an exported function, so
 490          * the automatic versioning doesn't pick it up, but it's really
 491          * important anyhow */
 492         if (modversions)
 493                 mod->unres = alloc_symbol("struct_module", 0, mod->unres);
 494 }
 495
 496 #define SZ 500
 497
 498 /* We first write the generated file into memory using the
 499  * following helper, then compare to the file on disk and
 500  * only update the later if anything changed */
 501
 502 void __attribute__((format(printf, 2, 3)))
 503 buf_printf(struct buffer *buf, const char *fmt, ...)
 504 {
 505         char tmp[SZ];
 506         int len;
 507         va_list ap;
 508
 509         va_start(ap, fmt);
 510         len = vsnprintf(tmp, SZ, fmt, ap);
 511         if (buf->size - buf->pos < len + 1) {
 512                 buf->size += 128;
 513                 buf->p = realloc(buf->p, buf->size);
 514         }
 515         strncpy(buf->p + buf->pos, tmp, len + 1);
 516         buf->pos += len;
 517         va_end(ap);
 518 }
 519
 520 void
 521 buf_write(struct buffer *buf, const char *s, int len)
 522 {
 523         if (buf->size - buf->pos < len) {
 524                 buf->size += len;
 525                 buf->p = realloc(buf->p, buf->size);
 526         }
 527         strncpy(buf->p + buf->pos, s, len);
 528         buf->pos += len;
 529 }
 530
 531 /* Header for the generated file */
 532
 533 void
 534 add_header(struct buffer *b, struct module *mod)
 535 {
 536         buf_printf(b, "#include <linux/module.h>\n");
 537         buf_printf(b, "#include <linux/vermagic.h>\n");
 538         buf_printf(b, "#include <linux/compiler.h>\n");
 539         buf_printf(b, "\n");
 540         buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
 541         buf_printf(b, "\n");
 542         buf_printf(b, "#undef unix\n"); /* We have a module called "unix" */
 543         buf_printf(b, "struct module __this_module\n");
 544         buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
 545         buf_printf(b, " .name = __stringify(KBUILD_MODNAME),\n");
 546         if (mod->has_init)
 547                 buf_printf(b, " .init = init_module,\n");
 548         if (mod->has_cleanup)
 549                 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
 550                               " .exit = cleanup_module,\n"
 551                               "#endif\n");
 552         buf_printf(b, "};\n");
 553 }
 554
 555 /* Record CRCs for unresolved symbols */
 556
 557 void
 558 add_versions(struct buffer *b, struct module *mod)
 559 {
 560         struct symbol *s, *exp;
 561
 562         for (s = mod->unres; s; s = s->next) {
 563                 exp = find_symbol(s->name);
 564                 if (!exp || exp->module == mod) {
 565                         if (have_vmlinux && !s->weak)
 566                                 fprintf(stderr, "*** Warning: \"%s\" [%s.ko] "
 567                                 "undefined!\n", s->name, mod->name);
 568                         continue;
 569                 }
 570                 s->module = exp->module;
 571                 s->crc_valid = exp->crc_valid;
 572                 s->crc = exp->crc;
 573         }
 574
 575         if (!modversions)
 576                 return;
 577
 578         buf_printf(b, "\n");
 579         buf_printf(b, "static const struct modversion_info ____versions[]\n");
 580         buf_printf(b, "__attribute_used__\n");
 581         buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
 582
 583         for (s = mod->unres; s; s = s->next) {
 584                 if (!s->module) {
 585                         continue;
 586                 }
 587                 if (!s->crc_valid) {
 588                         fprintf(stderr, "*** Warning: \"%s\" [%s.ko] "
 589                                 "has no CRC!\n",
 590                                 s->name, mod->name);
 591                         continue;
 592                 }
 593                 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
 594         }
 595
 596         buf_printf(b, "};\n");
 597 }
 598
 599 void
 600 add_depends(struct buffer *b, struct module *mod, struct module *modules)
 601 {
 602         struct symbol *s;
 603         struct module *m;
 604         int first = 1;
 605
 606         for (m = modules; m; m = m->next) {
 607                 m->seen = is_vmlinux(m->name);
 608         }
 609
 610         buf_printf(b, "\n");
 611         buf_printf(b, "static const char __module_depends[]\n");
 612         buf_printf(b, "__attribute_used__\n");
 613         buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
 614         buf_printf(b, "\"depends=");
 615         for (s = mod->unres; s; s = s->next) {
 616                 if (!s->module)
 617                         continue;
 618
 619                 if (s->module->seen)
 620                         continue;
 621
 622                 s->module->seen = 1;
 623                 buf_printf(b, "%s%s", first ? "" : ",",
 624                            strrchr(s->module->name, '/') + 1);
 625                 first = 0;
 626         }
 627         buf_printf(b, "\";\n");
 628 }
 629
 630 void
 631 add_srcversion(struct buffer *b, struct module *mod)
 632 {
 633         if (mod->srcversion[0]) {
 634                 buf_printf(b, "\n");
 635                 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
 636                            mod->srcversion);
 637         }
 638 }
 639
 640 void
 641 write_if_changed(struct buffer *b, const char *fname)
 642 {
 643         char *tmp;
 644         FILE *file;
 645         struct stat st;
 646
 647         file = fopen(fname, "r");
 648         if (!file)
 649                 goto write;
 650
 651         if (fstat(fileno(file), &st) < 0)
 652                 goto close_write;
 653
 654         if (st.st_size != b->pos)
 655                 goto close_write;
 656
 657         tmp = NOFAIL(malloc(b->pos));
 658         if (fread(tmp, 1, b->pos, file) != b->pos)
 659                 goto free_write;
 660
 661         if (memcmp(tmp, b->p, b->pos) != 0)
 662                 goto free_write;
 663
 664         free(tmp);
 665         fclose(file);
 666         return;
 667
 668  free_write:
 669         free(tmp);
 670  close_write:
 671         fclose(file);
 672  write:
 673         file = fopen(fname, "w");
 674         if (!file) {
 675                 perror(fname);
 676                 exit(1);
 677         }
 678         if (fwrite(b->p, 1, b->pos, file) != b->pos) {
 679                 perror(fname);
 680                 exit(1);
 681         }
 682         fclose(file);
 683 }
 684
 685 void
 686 read_dump(const char *fname)
 687 {
 688         unsigned long size, pos = 0;
 689         void *file = grab_file(fname, &size);
 690         char *line;
 691
 692         if (!file)
 693                 /* No symbol versions, silently ignore */
 694                 return;
 695
 696         while ((line = get_next_line(&pos, file, size))) {
 697                 char *symname, *modname, *d;
 698                 unsigned int crc;
 699                 struct module *mod;
 700
 701                 if (!(symname = strchr(line, '\t')))
 702                         goto fail;
 703                 *symname++ = '\0';
 704                 if (!(modname = strchr(symname, '\t')))
 705                         goto fail;
 706                 *modname++ = '\0';
 707                 if (strchr(modname, '\t'))
 708                         goto fail;
 709                 crc = strtoul(line, &d, 16);
 710                 if (*symname == '\0' || *modname == '\0' || *d != '\0')
 711                         goto fail;
 712
 713                 if (!(mod = find_module(modname))) {
 714                         if (is_vmlinux(modname)) {
 715                                 have_vmlinux = 1;
 716                         }
 717                         mod = new_module(NOFAIL(strdup(modname)));
 718                         mod->skip = 1;
 719                 }
 720                 add_exported_symbol(symname, mod, &crc);
 721         }
 722         return;
 723 fail:
 724         fatal("parse error in symbol dump file\n");
 725 }
 726
 727 void
 728 write_dump(const char *fname)
 729 {
 730         struct buffer buf = { };
 731         struct symbol *symbol;
 732         int n;
 733
 734         for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
 735                 symbol = symbolhash[n];
 736                 while (symbol) {
 737                         symbol = symbol->next;
 738                 }
 739         }
 740
 741         for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
 742                 symbol = symbolhash[n];
 743                 while (symbol) {
 744                         buf_printf(&buf, "0x%08x\t%s\t%s\n", symbol->crc,
 745                                 symbol->name, symbol->module->name);
 746                         symbol = symbol->next;
 747                 }
 748         }
 749         write_if_changed(&buf, fname);
 750 }
 751
 752 int
 753 main(int argc, char **argv)
 754 {
 755         struct module *mod;
 756         struct buffer buf = { };
 757         char fname[SZ];
 758         char *dump_read = NULL, *dump_write = NULL;
 759         int opt;
 760
 761         while ((opt = getopt(argc, argv, "i:mo:a")) != -1) {
 762                 switch(opt) {
 763                         case 'i':
 764                                 dump_read = optarg;
 765                                 break;
 766                         case 'm':
 767                                 modversions = 1;
 768                                 break;
 769                         case 'o':
 770                                 dump_write = optarg;
 771                                 break;
 772                         case 'a':
 773                                 all_versions = 1;
 774                                 break;
 775                         default:
 776                                 exit(1);
 777                 }
 778         }
 779
 780         if (dump_read)
 781                 read_dump(dump_read);
 782
 783         while (optind < argc) {
 784                 read_symbols(argv[optind++]);
 785         }
 786
 787         for (mod = modules; mod; mod = mod->next) {
 788                 if (mod->skip)
 789                         continue;
 790
 791                 buf.pos = 0;
 792
 793                 add_header(&buf, mod);
 794                 add_versions(&buf, mod);
 795                 add_depends(&buf, mod, modules);
 796                 add_moddevtable(&buf, mod);
 797                 add_srcversion(&buf, mod);
 798
 799                 sprintf(fname, "%s.mod.c", mod->name);
 800                 write_if_changed(&buf, fname);
 801         }
 802
 803         if (dump_write)
 804                 write_dump(dump_write);
 805
 806         return 0;
 807 }
 808