scripts/kallsyms.c

   1 /* Generate assembler source containing symbol information
   2  *
   3  * Copyright 2002       by Kai Germaschewski
   4  *
   5  * This software may be used and distributed according to the terms
   6  * of the GNU General Public License, incorporated herein by reference.
   7  *
   8  * Usage: nm -n vmlinux | scripts/kallsyms [--all-symbols] > symbols.S
   9  *
  10  *      Table compression uses all the unused char codes on the symbols and
  11  *  maps these to the most used substrings (tokens). For instance, it might
  12  *  map char code 0xF7 to represent "write_" and then in every symbol where
  13  *  "write_" appears it can be replaced by 0xF7, saving 5 bytes.
  14  *      The used codes themselves are also placed in the table so that the
  15  *  decompresion can work without "special cases".
  16  *      Applied to kernel symbols, this usually produces a compression ratio
  17  *  of about 50%.
  18  *
  19  */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <ctype.h>
  25 #include <limits.h>
  26
  27 #ifndef ARRAY_SIZE
  28 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
  29 #endif
  30
  31 #define KSYM_NAME_LEN           128
  32
  33 struct sym_entry {
  34         unsigned long long addr;
  35         unsigned int len;
  36         unsigned int start_pos;
  37         unsigned char *sym;
  38         unsigned int percpu_absolute;
  39 };
  40
  41 struct addr_range {
  42         const char *start_sym, *end_sym;
  43         unsigned long long start, end;
  44 };
  45
  46 static unsigned long long _text;
  47 static unsigned long long relative_base;
  48 static struct addr_range text_ranges[] = {
  49         { "_stext",     "_etext"     },
  50         { "_sinittext", "_einittext" },
  51 };
  52 #define text_range_text     (&text_ranges[0])
  53 #define text_range_inittext (&text_ranges[1])
  54
  55 static struct addr_range percpu_range = {
  56         "__per_cpu_start", "__per_cpu_end", -1ULL, 0
  57 };
  58
  59 static struct sym_entry *table;
  60 static unsigned int table_size, table_cnt;
  61 static int all_symbols = 0;
  62 static int absolute_percpu = 0;
  63 static int base_relative = 0;
  64
  65 static int token_profit[0x10000];
  66
  67 /* the table that holds the result of the compression */
  68 static unsigned char best_table[256][2];
  69 static unsigned char best_table_len[256];
  70
  71
  72 static void usage(void)
  73 {
  74         fprintf(stderr, "Usage: kallsyms [--all-symbols] "
  75                         "[--base-relative] < in.map > out.S\n");
  76         exit(1);
  77 }
  78
  79 /*
  80  * This ignores the intensely annoying "mapping symbols" found
  81  * in ARM ELF files: $a, $t and $d.
  82  */
  83 static int is_arm_mapping_symbol(const char *str)
  84 {
  85         return str[0] == '$' && strchr("axtd", str[1])
  86                && (str[2] == '\0' || str[2] == '.');
  87 }
  88
  89 static int check_symbol_range(const char *sym, unsigned long long addr,
  90                               struct addr_range *ranges, int entries)
  91 {
  92         size_t i;
  93         struct addr_range *ar;
  94
  95         for (i = 0; i < entries; ++i) {
  96                 ar = &ranges[i];
  97
  98                 if (strcmp(sym, ar->start_sym) == 0) {
  99                         ar->start = addr;
 100                         return 0;
 101                 } else if (strcmp(sym, ar->end_sym) == 0) {
 102                         ar->end = addr;
 103                         return 0;
 104                 }
 105         }
 106
 107         return 1;
 108 }
 109
 110 static int read_symbol(FILE *in, struct sym_entry *s)
 111 {
 112         char sym[500], stype;
 113         int rc;
 114
 115         rc = fscanf(in, "%llx %c %499s\n", &s->addr, &stype, sym);
 116         if (rc != 3) {
 117                 if (rc != EOF && fgets(sym, 500, in) == NULL)
 118                         fprintf(stderr, "Read error or end of file.\n");
 119                 return -1;
 120         }
 121         if (strlen(sym) >= KSYM_NAME_LEN) {
 122                 fprintf(stderr, "Symbol %s too long for kallsyms (%zu >= %d).\n"
 123                                 "Please increase KSYM_NAME_LEN both in kernel and kallsyms.c\n",
 124                         sym, strlen(sym), KSYM_NAME_LEN);
 125                 return -1;
 126         }
 127
 128         /* Ignore most absolute/undefined (?) symbols. */
 129         if (strcmp(sym, "_text") == 0)
 130                 _text = s->addr;
 131         else if (check_symbol_range(sym, s->addr, text_ranges,
 132                                     ARRAY_SIZE(text_ranges)) == 0)
 133                 /* nothing to do */;
 134         else if (toupper(stype) == 'A')
 135         {
 136                 /* Keep these useful absolute symbols */
 137                 if (strcmp(sym, "__kernel_syscall_via_break") &&
 138                     strcmp(sym, "__kernel_syscall_via_epc") &&
 139                     strcmp(sym, "__kernel_sigtramp") &&
 140                     strcmp(sym, "__gp"))
 141                         return -1;
 142
 143         }
 144         else if (toupper(stype) == 'U' ||
 145                  is_arm_mapping_symbol(sym))
 146                 return -1;
 147         /* exclude also MIPS ELF local symbols ($L123 instead of .L123) */
 148         else if (sym[0] == '$')
 149                 return -1;
 150         /* exclude debugging symbols */
 151         else if (stype == 'N' || stype == 'n')
 152                 return -1;
 153
 154         /* include the type field in the symbol name, so that it gets
 155          * compressed together */
 156         s->len = strlen(sym) + 1;
 157         s->sym = malloc(s->len + 1);
 158         if (!s->sym) {
 159                 fprintf(stderr, "kallsyms failure: "
 160                         "unable to allocate required amount of memory\n");
 161                 exit(EXIT_FAILURE);
 162         }
 163         strcpy((char *)s->sym + 1, sym);
 164         s->sym[0] = stype;
 165
 166         s->percpu_absolute = 0;
 167
 168         /* Record if we've found __per_cpu_start/end. */
 169         check_symbol_range(sym, s->addr, &percpu_range, 1);
 170
 171         return 0;
 172 }
 173
 174 static int symbol_in_range(struct sym_entry *s, struct addr_range *ranges,
 175                            int entries)
 176 {
 177         size_t i;
 178         struct addr_range *ar;
 179
 180         for (i = 0; i < entries; ++i) {
 181                 ar = &ranges[i];
 182
 183                 if (s->addr >= ar->start && s->addr <= ar->end)
 184                         return 1;
 185         }
 186
 187         return 0;
 188 }
 189
 190 static int symbol_valid(struct sym_entry *s)
 191 {
 192         /* Symbols which vary between passes.  Passes 1 and 2 must have
 193          * identical symbol lists.  The kallsyms_* symbols below are only added
 194          * after pass 1, they would be included in pass 2 when --all-symbols is
 195          * specified so exclude them to get a stable symbol list.
 196          */
 197         static char *special_symbols[] = {
 198                 "kallsyms_addresses",
 199                 "kallsyms_offsets",
 200                 "kallsyms_relative_base",
 201                 "kallsyms_num_syms",
 202                 "kallsyms_names",
 203                 "kallsyms_markers",
 204                 "kallsyms_token_table",
 205                 "kallsyms_token_index",
 206
 207         /* Exclude linker generated symbols which vary between passes */
 208                 "_SDA_BASE_",           /* ppc */
 209                 "_SDA2_BASE_",          /* ppc */
 210                 NULL };
 211
 212         static char *special_prefixes[] = {
 213                 "__crc_",               /* modversions */
 214                 "__efistub_",           /* arm64 EFI stub namespace */
 215                 NULL };
 216
 217         static char *special_suffixes[] = {
 218                 "_veneer",              /* arm */
 219                 "_from_arm",            /* arm */
 220                 "_from_thumb",          /* arm */
 221                 NULL };
 222
 223         int i;
 224         char *sym_name = (char *)s->sym + 1;
 225
 226         /* if --all-symbols is not specified, then symbols outside the text
 227          * and inittext sections are discarded */
 228         if (!all_symbols) {
 229                 if (symbol_in_range(s, text_ranges,
 230                                     ARRAY_SIZE(text_ranges)) == 0)
 231                         return 0;
 232                 /* Corner case.  Discard any symbols with the same value as
 233                  * _etext _einittext; they can move between pass 1 and 2 when
 234                  * the kallsyms data are added.  If these symbols move then
 235                  * they may get dropped in pass 2, which breaks the kallsyms
 236                  * rules.
 237                  */
 238                 if ((s->addr == text_range_text->end &&
 239                                 strcmp(sym_name,
 240                                        text_range_text->end_sym)) ||
 241                     (s->addr == text_range_inittext->end &&
 242                                 strcmp(sym_name,
 243                                        text_range_inittext->end_sym)))
 244                         return 0;
 245         }
 246
 247         /* Exclude symbols which vary between passes. */
 248         for (i = 0; special_symbols[i]; i++)
 249                 if (strcmp(sym_name, special_symbols[i]) == 0)
 250                         return 0;
 251
 252         for (i = 0; special_prefixes[i]; i++) {
 253                 int l = strlen(special_prefixes[i]);
 254
 255                 if (l <= strlen(sym_name) &&
 256                     strncmp(sym_name, special_prefixes[i], l) == 0)
 257                         return 0;
 258         }
 259
 260         for (i = 0; special_suffixes[i]; i++) {
 261                 int l = strlen(sym_name) - strlen(special_suffixes[i]);
 262
 263                 if (l >= 0 && strcmp(sym_name + l, special_suffixes[i]) == 0)
 264                         return 0;
 265         }
 266
 267         return 1;
 268 }
 269
 270 static void read_map(FILE *in)
 271 {
 272         while (!feof(in)) {
 273                 if (table_cnt >= table_size) {
 274                         table_size += 10000;
 275                         table = realloc(table, sizeof(*table) * table_size);
 276                         if (!table) {
 277                                 fprintf(stderr, "out of memory\n");
 278                                 exit (1);
 279                         }
 280                 }
 281                 if (read_symbol(in, &table[table_cnt]) == 0) {
 282                         table[table_cnt].start_pos = table_cnt;
 283                         table_cnt++;
 284                 }
 285         }
 286 }
 287
 288 static void output_label(char *label)
 289 {
 290         printf(".globl %s\n", label);
 291         printf("\tALGN\n");
 292         printf("%s:\n", label);
 293 }
 294
 295 /* uncompress a compressed symbol. When this function is called, the best table
 296  * might still be compressed itself, so the function needs to be recursive */
 297 static int expand_symbol(unsigned char *data, int len, char *result)
 298 {
 299         int c, rlen, total=0;
 300
 301         while (len) {
 302                 c = *data;
 303                 /* if the table holds a single char that is the same as the one
 304                  * we are looking for, then end the search */
 305                 if (best_table[c][0]==c && best_table_len[c]==1) {
 306                         *result++ = c;
 307                         total++;
 308                 } else {
 309                         /* if not, recurse and expand */
 310                         rlen = expand_symbol(best_table[c], best_table_len[c], result);
 311                         total += rlen;
 312                         result += rlen;
 313                 }
 314                 data++;
 315                 len--;
 316         }
 317         *result=0;
 318
 319         return total;
 320 }
 321
 322 static int symbol_absolute(struct sym_entry *s)
 323 {
 324         return s->percpu_absolute;
 325 }
 326
 327 static void write_src(void)
 328 {
 329         unsigned int i, k, off;
 330         unsigned int best_idx[256];
 331         unsigned int *markers;
 332         char buf[KSYM_NAME_LEN];
 333
 334         printf("#include <asm/bitsperlong.h>\n");
 335         printf("#if BITS_PER_LONG == 64\n");
 336         printf("#define PTR .quad\n");
 337         printf("#define ALGN .balign 8\n");
 338         printf("#else\n");
 339         printf("#define PTR .long\n");
 340         printf("#define ALGN .balign 4\n");
 341         printf("#endif\n");
 342
 343         printf("\t.section .rodata, \"a\"\n");
 344
 345         /* Provide proper symbols relocatability by their relativeness
 346          * to a fixed anchor point in the runtime image, either '_text'
 347          * for absolute address tables, in which case the linker will
 348          * emit the final addresses at build time. Otherwise, use the
 349          * offset relative to the lowest value encountered of all relative
 350          * symbols, and emit non-relocatable fixed offsets that will be fixed
 351          * up at runtime.
 352          *
 353          * The symbol names cannot be used to construct normal symbol
 354          * references as the list of symbols contains symbols that are
 355          * declared static and are private to their .o files.  This prevents
 356          * .tmp_kallsyms.o or any other object from referencing them.
 357          */
 358         if (!base_relative)
 359                 output_label("kallsyms_addresses");
 360         else
 361                 output_label("kallsyms_offsets");
 362
 363         for (i = 0; i < table_cnt; i++) {
 364                 if (base_relative) {
 365                         long long offset;
 366                         int overflow;
 367
 368                         if (!absolute_percpu) {
 369                                 offset = table[i].addr - relative_base;
 370                                 overflow = (offset < 0 || offset > UINT_MAX);
 371                         } else if (symbol_absolute(&table[i])) {
 372                                 offset = table[i].addr;
 373                                 overflow = (offset < 0 || offset > INT_MAX);
 374                         } else {
 375                                 offset = relative_base - table[i].addr - 1;
 376                                 overflow = (offset < INT_MIN || offset >= 0);
 377                         }
 378                         if (overflow) {
 379                                 fprintf(stderr, "kallsyms failure: "
 380                                         "%s symbol value %#llx out of range in relative mode\n",
 381                                         symbol_absolute(&table[i]) ? "absolute" : "relative",
 382                                         table[i].addr);
 383                                 exit(EXIT_FAILURE);
 384                         }
 385                         printf("\t.long\t%#x\n", (int)offset);
 386                 } else if (!symbol_absolute(&table[i])) {
 387                         if (_text <= table[i].addr)
 388                                 printf("\tPTR\t_text + %#llx\n",
 389                                         table[i].addr - _text);
 390                         else
 391                                 printf("\tPTR\t_text - %#llx\n",
 392                                         _text - table[i].addr);
 393                 } else {
 394                         printf("\tPTR\t%#llx\n", table[i].addr);
 395                 }
 396         }
 397         printf("\n");
 398
 399         if (base_relative) {
 400                 output_label("kallsyms_relative_base");
 401                 printf("\tPTR\t_text - %#llx\n", _text - relative_base);
 402                 printf("\n");
 403         }
 404
 405         output_label("kallsyms_num_syms");
 406         printf("\t.long\t%u\n", table_cnt);
 407         printf("\n");
 408
 409         /* table of offset markers, that give the offset in the compressed stream
 410          * every 256 symbols */
 411         markers = malloc(sizeof(unsigned int) * ((table_cnt + 255) / 256));
 412         if (!markers) {
 413                 fprintf(stderr, "kallsyms failure: "
 414                         "unable to allocate required memory\n");
 415                 exit(EXIT_FAILURE);
 416         }
 417
 418         output_label("kallsyms_names");
 419         off = 0;
 420         for (i = 0; i < table_cnt; i++) {
 421                 if ((i & 0xFF) == 0)
 422                         markers[i >> 8] = off;
 423
 424                 printf("\t.byte 0x%02x", table[i].len);
 425                 for (k = 0; k < table[i].len; k++)
 426                         printf(", 0x%02x", table[i].sym[k]);
 427                 printf("\n");
 428
 429                 off += table[i].len + 1;
 430         }
 431         printf("\n");
 432
 433         output_label("kallsyms_markers");
 434         for (i = 0; i < ((table_cnt + 255) >> 8); i++)
 435                 printf("\t.long\t%u\n", markers[i]);
 436         printf("\n");
 437
 438         free(markers);
 439
 440         output_label("kallsyms_token_table");
 441         off = 0;
 442         for (i = 0; i < 256; i++) {
 443                 best_idx[i] = off;
 444                 expand_symbol(best_table[i], best_table_len[i], buf);
 445                 printf("\t.asciz\t\"%s\"\n", buf);
 446                 off += strlen(buf) + 1;
 447         }
 448         printf("\n");
 449
 450         output_label("kallsyms_token_index");
 451         for (i = 0; i < 256; i++)
 452                 printf("\t.short\t%d\n", best_idx[i]);
 453         printf("\n");
 454 }
 455
 456
 457 /* table lookup compression functions */
 458
 459 /* count all the possible tokens in a symbol */
 460 static void learn_symbol(unsigned char *symbol, int len)
 461 {
 462         int i;
 463
 464         for (i = 0; i < len - 1; i++)
 465                 token_profit[ symbol[i] + (symbol[i + 1] << 8) ]++;
 466 }
 467
 468 /* decrease the count for all the possible tokens in a symbol */
 469 static void forget_symbol(unsigned char *symbol, int len)
 470 {
 471         int i;
 472
 473         for (i = 0; i < len - 1; i++)
 474                 token_profit[ symbol[i] + (symbol[i + 1] << 8) ]--;
 475 }
 476
 477 /* remove all the invalid symbols from the table and do the initial token count */
 478 static void build_initial_tok_table(void)
 479 {
 480         unsigned int i, pos;
 481
 482         pos = 0;
 483         for (i = 0; i < table_cnt; i++) {
 484                 if ( symbol_valid(&table[i]) ) {
 485                         if (pos != i)
 486                                 table[pos] = table[i];
 487                         learn_symbol(table[pos].sym, table[pos].len);
 488                         pos++;
 489                 }
 490         }
 491         table_cnt = pos;
 492 }
 493
 494 static void *find_token(unsigned char *str, int len, unsigned char *token)
 495 {
 496         int i;
 497
 498         for (i = 0; i < len - 1; i++) {
 499                 if (str[i] == token[0] && str[i+1] == token[1])
 500                         return &str[i];
 501         }
 502         return NULL;
 503 }
 504
 505 /* replace a given token in all the valid symbols. Use the sampled symbols
 506  * to update the counts */
 507 static void compress_symbols(unsigned char *str, int idx)
 508 {
 509         unsigned int i, len, size;
 510         unsigned char *p1, *p2;
 511
 512         for (i = 0; i < table_cnt; i++) {
 513
 514                 len = table[i].len;
 515                 p1 = table[i].sym;
 516
 517                 /* find the token on the symbol */
 518                 p2 = find_token(p1, len, str);
 519                 if (!p2) continue;
 520
 521                 /* decrease the counts for this symbol's tokens */
 522                 forget_symbol(table[i].sym, len);
 523
 524                 size = len;
 525
 526                 do {
 527                         *p2 = idx;
 528                         p2++;
 529                         size -= (p2 - p1);
 530                         memmove(p2, p2 + 1, size);
 531                         p1 = p2;
 532                         len--;
 533
 534                         if (size < 2) break;
 535
 536                         /* find the token on the symbol */
 537                         p2 = find_token(p1, size, str);
 538
 539                 } while (p2);
 540
 541                 table[i].len = len;
 542
 543                 /* increase the counts for this symbol's new tokens */
 544                 learn_symbol(table[i].sym, len);
 545         }
 546 }
 547
 548 /* search the token with the maximum profit */
 549 static int find_best_token(void)
 550 {
 551         int i, best, bestprofit;
 552
 553         bestprofit=-10000;
 554         best = 0;
 555
 556         for (i = 0; i < 0x10000; i++) {
 557                 if (token_profit[i] > bestprofit) {
 558                         best = i;
 559                         bestprofit = token_profit[i];
 560                 }
 561         }
 562         return best;
 563 }
 564
 565 /* this is the core of the algorithm: calculate the "best" table */
 566 static void optimize_result(void)
 567 {
 568         int i, best;
 569
 570         /* using the '\0' symbol last allows compress_symbols to use standard
 571          * fast string functions */
 572         for (i = 255; i >= 0; i--) {
 573
 574                 /* if this table slot is empty (it is not used by an actual
 575                  * original char code */
 576                 if (!best_table_len[i]) {
 577
 578                         /* find the token with the best profit value */
 579                         best = find_best_token();
 580                         if (token_profit[best] == 0)
 581                                 break;
 582
 583                         /* place it in the "best" table */
 584                         best_table_len[i] = 2;
 585                         best_table[i][0] = best & 0xFF;
 586                         best_table[i][1] = (best >> 8) & 0xFF;
 587
 588                         /* replace this token in all the valid symbols */
 589                         compress_symbols(best_table[i], i);
 590                 }
 591         }
 592 }
 593
 594 /* start by placing the symbols that are actually used on the table */
 595 static void insert_real_symbols_in_table(void)
 596 {
 597         unsigned int i, j, c;
 598
 599         for (i = 0; i < table_cnt; i++) {
 600                 for (j = 0; j < table[i].len; j++) {
 601                         c = table[i].sym[j];
 602                         best_table[c][0]=c;
 603                         best_table_len[c]=1;
 604                 }
 605         }
 606 }
 607
 608 static void optimize_token_table(void)
 609 {
 610         build_initial_tok_table();
 611
 612         insert_real_symbols_in_table();
 613
 614         /* When valid symbol is not registered, exit to error */
 615         if (!table_cnt) {
 616                 fprintf(stderr, "No valid symbol.\n");
 617                 exit(1);
 618         }
 619
 620         optimize_result();
 621 }
 622
 623 /* guess for "linker script provide" symbol */
 624 static int may_be_linker_script_provide_symbol(const struct sym_entry *se)
 625 {
 626         const char *symbol = (char *)se->sym + 1;
 627         int len = se->len - 1;
 628
 629         if (len < 8)
 630                 return 0;
 631
 632         if (symbol[0] != '_' || symbol[1] != '_')
 633                 return 0;
 634
 635         /* __start_XXXXX */
 636         if (!memcmp(symbol + 2, "start_", 6))
 637                 return 1;
 638
 639         /* __stop_XXXXX */
 640         if (!memcmp(symbol + 2, "stop_", 5))
 641                 return 1;
 642
 643         /* __end_XXXXX */
 644         if (!memcmp(symbol + 2, "end_", 4))
 645                 return 1;
 646
 647         /* __XXXXX_start */
 648         if (!memcmp(symbol + len - 6, "_start", 6))
 649                 return 1;
 650
 651         /* __XXXXX_end */
 652         if (!memcmp(symbol + len - 4, "_end", 4))
 653                 return 1;
 654
 655         return 0;
 656 }
 657
 658 static int prefix_underscores_count(const char *str)
 659 {
 660         const char *tail = str;
 661
 662         while (*tail == '_')
 663                 tail++;
 664
 665         return tail - str;
 666 }
 667
 668 static int compare_symbols(const void *a, const void *b)
 669 {
 670         const struct sym_entry *sa;
 671         const struct sym_entry *sb;
 672         int wa, wb;
 673
 674         sa = a;
 675         sb = b;
 676
 677         /* sort by address first */
 678         if (sa->addr > sb->addr)
 679                 return 1;
 680         if (sa->addr < sb->addr)
 681                 return -1;
 682
 683         /* sort by "weakness" type */
 684         wa = (sa->sym[0] == 'w') || (sa->sym[0] == 'W');
 685         wb = (sb->sym[0] == 'w') || (sb->sym[0] == 'W');
 686         if (wa != wb)
 687                 return wa - wb;
 688
 689         /* sort by "linker script provide" type */
 690         wa = may_be_linker_script_provide_symbol(sa);
 691         wb = may_be_linker_script_provide_symbol(sb);
 692         if (wa != wb)
 693                 return wa - wb;
 694
 695         /* sort by the number of prefix underscores */
 696         wa = prefix_underscores_count((const char *)sa->sym + 1);
 697         wb = prefix_underscores_count((const char *)sb->sym + 1);
 698         if (wa != wb)
 699                 return wa - wb;
 700
 701         /* sort by initial order, so that other symbols are left undisturbed */
 702         return sa->start_pos - sb->start_pos;
 703 }
 704
 705 static void sort_symbols(void)
 706 {
 707         qsort(table, table_cnt, sizeof(struct sym_entry), compare_symbols);
 708 }
 709
 710 static void make_percpus_absolute(void)
 711 {
 712         unsigned int i;
 713
 714         for (i = 0; i < table_cnt; i++)
 715                 if (symbol_in_range(&table[i], &percpu_range, 1)) {
 716                         /*
 717                          * Keep the 'A' override for percpu symbols to
 718                          * ensure consistent behavior compared to older
 719                          * versions of this tool.
 720                          */
 721                         table[i].sym[0] = 'A';
 722                         table[i].percpu_absolute = 1;
 723                 }
 724 }
 725
 726 /* find the minimum non-absolute symbol address */
 727 static void record_relative_base(void)
 728 {
 729         unsigned int i;
 730
 731         relative_base = -1ULL;
 732         for (i = 0; i < table_cnt; i++)
 733                 if (!symbol_absolute(&table[i]) &&
 734                     table[i].addr < relative_base)
 735                         relative_base = table[i].addr;
 736 }
 737
 738 int main(int argc, char **argv)
 739 {
 740         if (argc >= 2) {
 741                 int i;
 742                 for (i = 1; i < argc; i++) {
 743                         if(strcmp(argv[i], "--all-symbols") == 0)
 744                                 all_symbols = 1;
 745                         else if (strcmp(argv[i], "--absolute-percpu") == 0)
 746                                 absolute_percpu = 1;
 747                         else if (strcmp(argv[i], "--base-relative") == 0)
 748                                 base_relative = 1;
 749                         else
 750                                 usage();
 751                 }
 752         } else if (argc != 1)
 753                 usage();
 754
 755         read_map(stdin);
 756         if (absolute_percpu)
 757                 make_percpus_absolute();
 758         if (base_relative)
 759                 record_relative_base();
 760         sort_symbols();
 761         optimize_token_table();
 762         write_src();
 763
 764         return 0;
 765 }