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     MODULE_SYMBOL_PREFIX "__crc_"
 330 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__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                 }
 374 #endif
 375
 376                 if (memcmp(symname, MODULE_SYMBOL_PREFIX,
 377                            strlen(MODULE_SYMBOL_PREFIX)) == 0)
 378                         mod->unres = alloc_symbol(symname +
 379                                                   strlen(MODULE_SYMBOL_PREFIX),
 380                                                   ELF_ST_BIND(sym->st_info) == STB_WEAK,
 381                                                   mod->unres);
 382                 break;
 383         default:
 384                 /* All exported symbols */
 385                 if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
 386                         add_exported_symbol(symname + strlen(KSYMTAB_PFX),
 387                                             mod, NULL);
 388                 }
 389                 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
 390                         mod->has_init = 1;
 391                 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
 392                         mod->has_cleanup = 1;
 393                 break;
 394         }
 395 }
 396
 397 int
 398 is_vmlinux(const char *modname)
 399 {
 400         const char *myname;
 401
 402         if ((myname = strrchr(modname, '/')))
 403                 myname++;
 404         else
 405                 myname = modname;
 406
 407         return strcmp(myname, "vmlinux") == 0;
 408 }
 409
 410 /* Parse tag=value strings from .modinfo section */
 411 static char *next_string(char *string, unsigned long *secsize)
 412 {
 413         /* Skip non-zero chars */
 414         while (string[0]) {
 415                 string++;
 416                 if ((*secsize)-- <= 1)
 417                         return NULL;
 418         }
 419
 420         /* Skip any zero padding. */
 421         while (!string[0]) {
 422                 string++;
 423                 if ((*secsize)-- <= 1)
 424                         return NULL;
 425         }
 426         return string;
 427 }
 428
 429 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
 430                          const char *tag)
 431 {
 432         char *p;
 433         unsigned int taglen = strlen(tag);
 434         unsigned long size = modinfo_len;
 435
 436         for (p = modinfo; p; p = next_string(p, &size)) {
 437                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
 438                         return p + taglen + 1;
 439         }
 440         return NULL;
 441 }
 442
 443 void
 444 read_symbols(char *modname)
 445 {
 446         const char *symname;
 447         char *version;
 448         struct module *mod;
 449         struct elf_info info = { };
 450         Elf_Sym *sym;
 451
 452         parse_elf(&info, modname);
 453
 454         mod = new_module(modname);
 455
 456         /* When there's no vmlinux, don't print warnings about
 457          * unresolved symbols (since there'll be too many ;) */
 458         if (is_vmlinux(modname)) {
 459                 unsigned int fake_crc = 0;
 460                 have_vmlinux = 1;
 461                 add_exported_symbol("struct_module", mod, &fake_crc);
 462                 mod->skip = 1;
 463         }
 464
 465         for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
 466                 symname = info.strtab + sym->st_name;
 467
 468                 handle_modversions(mod, &info, sym, symname);
 469                 handle_moddevtable(mod, &info, sym, symname);
 470         }
 471
 472         version = get_modinfo(info.modinfo, info.modinfo_len, "version");
 473         if (version)
 474                 maybe_frob_rcs_version(modname, version, info.modinfo,
 475                                        version - (char *)info.hdr);
 476         if (version || (all_versions && !is_vmlinux(modname)))
 477                 get_src_version(modname, mod->srcversion,
 478                                 sizeof(mod->srcversion)-1);
 479
 480         parse_elf_finish(&info);
 481
 482         /* Our trick to get versioning for struct_module - it's
 483          * never passed as an argument to an exported function, so
 484          * the automatic versioning doesn't pick it up, but it's really
 485          * important anyhow */
 486         if (modversions)
 487                 mod->unres = alloc_symbol("struct_module", 0, mod->unres);
 488 }
 489
 490 #define SZ 500
 491
 492 /* We first write the generated file into memory using the
 493  * following helper, then compare to the file on disk and
 494  * only update the later if anything changed */
 495
 496 void __attribute__((format(printf, 2, 3)))
 497 buf_printf(struct buffer *buf, const char *fmt, ...)
 498 {
 499         char tmp[SZ];
 500         int len;
 501         va_list ap;
 502
 503         va_start(ap, fmt);
 504         len = vsnprintf(tmp, SZ, fmt, ap);
 505         if (buf->size - buf->pos < len + 1) {
 506                 buf->size += 128;
 507                 buf->p = realloc(buf->p, buf->size);
 508         }
 509         strncpy(buf->p + buf->pos, tmp, len + 1);
 510         buf->pos += len;
 511         va_end(ap);
 512 }
 513
 514 void
 515 buf_write(struct buffer *buf, const char *s, int len)
 516 {
 517         if (buf->size - buf->pos < len) {
 518                 buf->size += len;
 519                 buf->p = realloc(buf->p, buf->size);
 520         }
 521         strncpy(buf->p + buf->pos, s, len);
 522         buf->pos += len;
 523 }
 524
 525 /* Header for the generated file */
 526
 527 void
 528 add_header(struct buffer *b, struct module *mod)
 529 {
 530         buf_printf(b, "#include <linux/module.h>\n");
 531         buf_printf(b, "#include <linux/vermagic.h>\n");
 532         buf_printf(b, "#include <linux/compiler.h>\n");
 533         buf_printf(b, "\n");
 534         buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
 535         buf_printf(b, "\n");
 536         buf_printf(b, "#undef unix\n"); /* We have a module called "unix" */
 537         buf_printf(b, "struct module __this_module\n");
 538         buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
 539         buf_printf(b, " .name = __stringify(KBUILD_MODNAME),\n");
 540         if (mod->has_init)
 541                 buf_printf(b, " .init = init_module,\n");
 542         if (mod->has_cleanup)
 543                 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
 544                               " .exit = cleanup_module,\n"
 545                               "#endif\n");
 546         buf_printf(b, "};\n");
 547 }
 548
 549 /* Record CRCs for unresolved symbols */
 550
 551 void
 552 add_versions(struct buffer *b, struct module *mod)
 553 {
 554         struct symbol *s, *exp;
 555
 556         for (s = mod->unres; s; s = s->next) {
 557                 exp = find_symbol(s->name);
 558                 if (!exp || exp->module == mod) {
 559                         if (have_vmlinux && !s->weak)
 560                                 fprintf(stderr, "*** Warning: \"%s\" [%s.ko] "
 561                                 "undefined!\n", s->name, mod->name);
 562                         continue;
 563                 }
 564                 s->module = exp->module;
 565                 s->crc_valid = exp->crc_valid;
 566                 s->crc = exp->crc;
 567         }
 568
 569         if (!modversions)
 570                 return;
 571
 572         buf_printf(b, "\n");
 573         buf_printf(b, "static const struct modversion_info ____versions[]\n");
 574         buf_printf(b, "__attribute_used__\n");
 575         buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
 576
 577         for (s = mod->unres; s; s = s->next) {
 578                 if (!s->module) {
 579                         continue;
 580                 }
 581                 if (!s->crc_valid) {
 582                         fprintf(stderr, "*** Warning: \"%s\" [%s.ko] "
 583                                 "has no CRC!\n",
 584                                 s->name, mod->name);
 585                         continue;
 586                 }
 587                 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
 588         }
 589
 590         buf_printf(b, "};\n");
 591 }
 592
 593 void
 594 add_depends(struct buffer *b, struct module *mod, struct module *modules)
 595 {
 596         struct symbol *s;
 597         struct module *m;
 598         int first = 1;
 599
 600         for (m = modules; m; m = m->next) {
 601                 m->seen = is_vmlinux(m->name);
 602         }
 603
 604         buf_printf(b, "\n");
 605         buf_printf(b, "static const char __module_depends[]\n");
 606         buf_printf(b, "__attribute_used__\n");
 607         buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
 608         buf_printf(b, "\"depends=");
 609         for (s = mod->unres; s; s = s->next) {
 610                 if (!s->module)
 611                         continue;
 612
 613                 if (s->module->seen)
 614                         continue;
 615
 616                 s->module->seen = 1;
 617                 buf_printf(b, "%s%s", first ? "" : ",",
 618                            strrchr(s->module->name, '/') + 1);
 619                 first = 0;
 620         }
 621         buf_printf(b, "\";\n");
 622 }
 623
 624 void
 625 add_srcversion(struct buffer *b, struct module *mod)
 626 {
 627         if (mod->srcversion[0]) {
 628                 buf_printf(b, "\n");
 629                 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
 630                            mod->srcversion);
 631         }
 632 }
 633
 634 void
 635 write_if_changed(struct buffer *b, const char *fname)
 636 {
 637         char *tmp;
 638         FILE *file;
 639         struct stat st;
 640
 641         file = fopen(fname, "r");
 642         if (!file)
 643                 goto write;
 644
 645         if (fstat(fileno(file), &st) < 0)
 646                 goto close_write;
 647
 648         if (st.st_size != b->pos)
 649                 goto close_write;
 650
 651         tmp = NOFAIL(malloc(b->pos));
 652         if (fread(tmp, 1, b->pos, file) != b->pos)
 653                 goto free_write;
 654
 655         if (memcmp(tmp, b->p, b->pos) != 0)
 656                 goto free_write;
 657
 658         free(tmp);
 659         fclose(file);
 660         return;
 661
 662  free_write:
 663         free(tmp);
 664  close_write:
 665         fclose(file);
 666  write:
 667         file = fopen(fname, "w");
 668         if (!file) {
 669                 perror(fname);
 670                 exit(1);
 671         }
 672         if (fwrite(b->p, 1, b->pos, file) != b->pos) {
 673                 perror(fname);
 674                 exit(1);
 675         }
 676         fclose(file);
 677 }
 678
 679 void
 680 read_dump(const char *fname)
 681 {
 682         unsigned long size, pos = 0;
 683         void *file = grab_file(fname, &size);
 684         char *line;
 685
 686         if (!file)
 687                 /* No symbol versions, silently ignore */
 688                 return;
 689
 690         while ((line = get_next_line(&pos, file, size))) {
 691                 char *symname, *modname, *d;
 692                 unsigned int crc;
 693                 struct module *mod;
 694
 695                 if (!(symname = strchr(line, '\t')))
 696                         goto fail;
 697                 *symname++ = '\0';
 698                 if (!(modname = strchr(symname, '\t')))
 699                         goto fail;
 700                 *modname++ = '\0';
 701                 if (strchr(modname, '\t'))
 702                         goto fail;
 703                 crc = strtoul(line, &d, 16);
 704                 if (*symname == '\0' || *modname == '\0' || *d != '\0')
 705                         goto fail;
 706
 707                 if (!(mod = find_module(modname))) {
 708                         if (is_vmlinux(modname)) {
 709                                 have_vmlinux = 1;
 710                         }
 711                         mod = new_module(NOFAIL(strdup(modname)));
 712                         mod->skip = 1;
 713                 }
 714                 add_exported_symbol(symname, mod, &crc);
 715         }
 716         return;
 717 fail:
 718         fatal("parse error in symbol dump file\n");
 719 }
 720
 721 void
 722 write_dump(const char *fname)
 723 {
 724         struct buffer buf = { };
 725         struct symbol *symbol;
 726         int n;
 727
 728         for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
 729                 symbol = symbolhash[n];
 730                 while (symbol) {
 731                         symbol = symbol->next;
 732                 }
 733         }
 734
 735         for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
 736                 symbol = symbolhash[n];
 737                 while (symbol) {
 738                         buf_printf(&buf, "0x%08x\t%s\t%s\n", symbol->crc,
 739                                 symbol->name, symbol->module->name);
 740                         symbol = symbol->next;
 741                 }
 742         }
 743         write_if_changed(&buf, fname);
 744 }
 745
 746 int
 747 main(int argc, char **argv)
 748 {
 749         struct module *mod;
 750         struct buffer buf = { };
 751         char fname[SZ];
 752         char *dump_read = NULL, *dump_write = NULL;
 753         int opt;
 754
 755         while ((opt = getopt(argc, argv, "i:mo:a")) != -1) {
 756                 switch(opt) {
 757                         case 'i':
 758                                 dump_read = optarg;
 759                                 break;
 760                         case 'm':
 761                                 modversions = 1;
 762                                 break;
 763                         case 'o':
 764                                 dump_write = optarg;
 765                                 break;
 766                         case 'a':
 767                                 all_versions = 1;
 768                                 break;
 769                         default:
 770                                 exit(1);
 771                 }
 772         }
 773
 774         if (dump_read)
 775                 read_dump(dump_read);
 776
 777         while (optind < argc) {
 778                 read_symbols(argv[optind++]);
 779         }
 780
 781         for (mod = modules; mod; mod = mod->next) {
 782                 if (mod->skip)
 783                         continue;
 784
 785                 buf.pos = 0;
 786
 787                 add_header(&buf, mod);
 788                 add_versions(&buf, mod);
 789                 add_depends(&buf, mod, modules);
 790                 add_moddevtable(&buf, mod);
 791                 add_srcversion(&buf, mod);
 792
 793                 sprintf(fname, "%s.mod.c", mod->name);
 794                 write_if_changed(&buf, fname);
 795         }
 796
 797         if (dump_write)
 798                 write_dump(dump_write);
 799
 800         return 0;
 801 }
 802