linux/scripts/kallsyms.c
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   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
  33struct 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
  41struct addr_range {
  42        const char *start_sym, *end_sym;
  43        unsigned long long start, end;
  44};
  45
  46static unsigned long long _text;
  47static unsigned long long relative_base;
  48static struct addr_range text_ranges[] = {
  49        { "_stext",     "_etext"     },
  50        { "_sinittext", "_einittext" },
  51        { "_stext_l1",  "_etext_l1"  }, /* Blackfin on-chip L1 inst SRAM */
  52        { "_stext_l2",  "_etext_l2"  }, /* Blackfin on-chip L2 SRAM */
  53};
  54#define text_range_text     (&text_ranges[0])
  55#define text_range_inittext (&text_ranges[1])
  56
  57static struct addr_range percpu_range = {
  58        "__per_cpu_start", "__per_cpu_end", -1ULL, 0
  59};
  60
  61static struct sym_entry *table;
  62static unsigned int table_size, table_cnt;
  63static int all_symbols = 0;
  64static int absolute_percpu = 0;
  65static char symbol_prefix_char = '\0';
  66static int base_relative = 0;
  67
  68int token_profit[0x10000];
  69
  70/* the table that holds the result of the compression */
  71unsigned char best_table[256][2];
  72unsigned char best_table_len[256];
  73
  74
  75static void usage(void)
  76{
  77        fprintf(stderr, "Usage: kallsyms [--all-symbols] "
  78                        "[--symbol-prefix=<prefix char>] "
  79                        "[--page-offset=<CONFIG_PAGE_OFFSET>] "
  80                        "[--base-relative] < in.map > out.S\n");
  81        exit(1);
  82}
  83
  84/*
  85 * This ignores the intensely annoying "mapping symbols" found
  86 * in ARM ELF files: $a, $t and $d.
  87 */
  88static inline int is_arm_mapping_symbol(const char *str)
  89{
  90        return str[0] == '$' && strchr("axtd", str[1])
  91               && (str[2] == '\0' || str[2] == '.');
  92}
  93
  94static int check_symbol_range(const char *sym, unsigned long long addr,
  95                              struct addr_range *ranges, int entries)
  96{
  97        size_t i;
  98        struct addr_range *ar;
  99
 100        for (i = 0; i < entries; ++i) {
 101                ar = &ranges[i];
 102
 103                if (strcmp(sym, ar->start_sym) == 0) {
 104                        ar->start = addr;
 105                        return 0;
 106                } else if (strcmp(sym, ar->end_sym) == 0) {
 107                        ar->end = addr;
 108                        return 0;
 109                }
 110        }
 111
 112        return 1;
 113}
 114
 115static int read_symbol(FILE *in, struct sym_entry *s)
 116{
 117        char str[500];
 118        char *sym, stype;
 119        int rc;
 120
 121        rc = fscanf(in, "%llx %c %499s\n", &s->addr, &stype, str);
 122        if (rc != 3) {
 123                if (rc != EOF && fgets(str, 500, in) == NULL)
 124                        fprintf(stderr, "Read error or end of file.\n");
 125                return -1;
 126        }
 127        if (strlen(str) > KSYM_NAME_LEN) {
 128                fprintf(stderr, "Symbol %s too long for kallsyms (%zu vs %d).\n"
 129                                "Please increase KSYM_NAME_LEN both in kernel and kallsyms.c\n",
 130                        str, strlen(str), KSYM_NAME_LEN);
 131                return -1;
 132        }
 133
 134        sym = str;
 135        /* skip prefix char */
 136        if (symbol_prefix_char && str[0] == symbol_prefix_char)
 137                sym++;
 138
 139        /* Ignore most absolute/undefined (?) symbols. */
 140        if (strcmp(sym, "_text") == 0)
 141                _text = s->addr;
 142        else if (check_symbol_range(sym, s->addr, text_ranges,
 143                                    ARRAY_SIZE(text_ranges)) == 0)
 144                /* nothing to do */;
 145        else if (toupper(stype) == 'A')
 146        {
 147                /* Keep these useful absolute symbols */
 148                if (strcmp(sym, "__kernel_syscall_via_break") &&
 149                    strcmp(sym, "__kernel_syscall_via_epc") &&
 150                    strcmp(sym, "__kernel_sigtramp") &&
 151                    strcmp(sym, "__gp"))
 152                        return -1;
 153
 154        }
 155        else if (toupper(stype) == 'U' ||
 156                 is_arm_mapping_symbol(sym))
 157                return -1;
 158        /* exclude also MIPS ELF local symbols ($L123 instead of .L123) */
 159        else if (str[0] == '$')
 160                return -1;
 161        /* exclude debugging symbols */
 162        else if (stype == 'N')
 163                return -1;
 164
 165        /* include the type field in the symbol name, so that it gets
 166         * compressed together */
 167        s->len = strlen(str) + 1;
 168        s->sym = malloc(s->len + 1);
 169        if (!s->sym) {
 170                fprintf(stderr, "kallsyms failure: "
 171                        "unable to allocate required amount of memory\n");
 172                exit(EXIT_FAILURE);
 173        }
 174        strcpy((char *)s->sym + 1, str);
 175        s->sym[0] = stype;
 176
 177        s->percpu_absolute = 0;
 178
 179        /* Record if we've found __per_cpu_start/end. */
 180        check_symbol_range(sym, s->addr, &percpu_range, 1);
 181
 182        return 0;
 183}
 184
 185static int symbol_in_range(struct sym_entry *s, struct addr_range *ranges,
 186                           int entries)
 187{
 188        size_t i;
 189        struct addr_range *ar;
 190
 191        for (i = 0; i < entries; ++i) {
 192                ar = &ranges[i];
 193
 194                if (s->addr >= ar->start && s->addr <= ar->end)
 195                        return 1;
 196        }
 197
 198        return 0;
 199}
 200
 201static int symbol_valid(struct sym_entry *s)
 202{
 203        /* Symbols which vary between passes.  Passes 1 and 2 must have
 204         * identical symbol lists.  The kallsyms_* symbols below are only added
 205         * after pass 1, they would be included in pass 2 when --all-symbols is
 206         * specified so exclude them to get a stable symbol list.
 207         */
 208        static char *special_symbols[] = {
 209                "kallsyms_addresses",
 210                "kallsyms_offsets",
 211                "kallsyms_relative_base",
 212                "kallsyms_num_syms",
 213                "kallsyms_names",
 214                "kallsyms_markers",
 215                "kallsyms_token_table",
 216                "kallsyms_token_index",
 217
 218        /* Exclude linker generated symbols which vary between passes */
 219                "_SDA_BASE_",           /* ppc */
 220                "_SDA2_BASE_",          /* ppc */
 221                NULL };
 222
 223        static char *special_suffixes[] = {
 224                "_veneer",              /* arm */
 225                "_from_arm",            /* arm */
 226                "_from_thumb",          /* arm */
 227                NULL };
 228
 229        int i;
 230        char *sym_name = (char *)s->sym + 1;
 231
 232        /* skip prefix char */
 233        if (symbol_prefix_char && *sym_name == symbol_prefix_char)
 234                sym_name++;
 235
 236
 237        /* if --all-symbols is not specified, then symbols outside the text
 238         * and inittext sections are discarded */
 239        if (!all_symbols) {
 240                if (symbol_in_range(s, text_ranges,
 241                                    ARRAY_SIZE(text_ranges)) == 0)
 242                        return 0;
 243                /* Corner case.  Discard any symbols with the same value as
 244                 * _etext _einittext; they can move between pass 1 and 2 when
 245                 * the kallsyms data are added.  If these symbols move then
 246                 * they may get dropped in pass 2, which breaks the kallsyms
 247                 * rules.
 248                 */
 249                if ((s->addr == text_range_text->end &&
 250                                strcmp(sym_name,
 251                                       text_range_text->end_sym)) ||
 252                    (s->addr == text_range_inittext->end &&
 253                                strcmp(sym_name,
 254                                       text_range_inittext->end_sym)))
 255                        return 0;
 256        }
 257
 258        /* Exclude symbols which vary between passes. */
 259        for (i = 0; special_symbols[i]; i++)
 260                if (strcmp(sym_name, special_symbols[i]) == 0)
 261                        return 0;
 262
 263        for (i = 0; special_suffixes[i]; i++) {
 264                int l = strlen(sym_name) - strlen(special_suffixes[i]);
 265
 266                if (l >= 0 && strcmp(sym_name + l, special_suffixes[i]) == 0)
 267                        return 0;
 268        }
 269
 270        return 1;
 271}
 272
 273static void read_map(FILE *in)
 274{
 275        while (!feof(in)) {
 276                if (table_cnt >= table_size) {
 277                        table_size += 10000;
 278                        table = realloc(table, sizeof(*table) * table_size);
 279                        if (!table) {
 280                                fprintf(stderr, "out of memory\n");
 281                                exit (1);
 282                        }
 283                }
 284                if (read_symbol(in, &table[table_cnt]) == 0) {
 285                        table[table_cnt].start_pos = table_cnt;
 286                        table_cnt++;
 287                }
 288        }
 289}
 290
 291static void output_label(char *label)
 292{
 293        if (symbol_prefix_char)
 294                printf(".globl %c%s\n", symbol_prefix_char, label);
 295        else
 296                printf(".globl %s\n", label);
 297        printf("\tALGN\n");
 298        if (symbol_prefix_char)
 299                printf("%c%s:\n", symbol_prefix_char, label);
 300        else
 301                printf("%s:\n", label);
 302}
 303
 304/* uncompress a compressed symbol. When this function is called, the best table
 305 * might still be compressed itself, so the function needs to be recursive */
 306static int expand_symbol(unsigned char *data, int len, char *result)
 307{
 308        int c, rlen, total=0;
 309
 310        while (len) {
 311                c = *data;
 312                /* if the table holds a single char that is the same as the one
 313                 * we are looking for, then end the search */
 314                if (best_table[c][0]==c && best_table_len[c]==1) {
 315                        *result++ = c;
 316                        total++;
 317                } else {
 318                        /* if not, recurse and expand */
 319                        rlen = expand_symbol(best_table[c], best_table_len[c], result);
 320                        total += rlen;
 321                        result += rlen;
 322                }
 323                data++;
 324                len--;
 325        }
 326        *result=0;
 327
 328        return total;
 329}
 330
 331static int symbol_absolute(struct sym_entry *s)
 332{
 333        return s->percpu_absolute;
 334}
 335
 336static void write_src(void)
 337{
 338        unsigned int i, k, off;
 339        unsigned int best_idx[256];
 340        unsigned int *markers;
 341        char buf[KSYM_NAME_LEN];
 342
 343        printf("#include <asm/types.h>\n");
 344        printf("#if BITS_PER_LONG == 64\n");
 345        printf("#define PTR .quad\n");
 346        printf("#define ALGN .align 8\n");
 347        printf("#else\n");
 348        printf("#define PTR .long\n");
 349        printf("#define ALGN .align 4\n");
 350        printf("#endif\n");
 351
 352        printf("\t.section .rodata, \"a\"\n");
 353
 354        /* Provide proper symbols relocatability by their relativeness
 355         * to a fixed anchor point in the runtime image, either '_text'
 356         * for absolute address tables, in which case the linker will
 357         * emit the final addresses at build time. Otherwise, use the
 358         * offset relative to the lowest value encountered of all relative
 359         * symbols, and emit non-relocatable fixed offsets that will be fixed
 360         * up at runtime.
 361         *
 362         * The symbol names cannot be used to construct normal symbol
 363         * references as the list of symbols contains symbols that are
 364         * declared static and are private to their .o files.  This prevents
 365         * .tmp_kallsyms.o or any other object from referencing them.
 366         */
 367        if (!base_relative)
 368                output_label("kallsyms_addresses");
 369        else
 370                output_label("kallsyms_offsets");
 371
 372        for (i = 0; i < table_cnt; i++) {
 373                if (base_relative) {
 374                        long long offset;
 375                        int overflow;
 376
 377                        if (!absolute_percpu) {
 378                                offset = table[i].addr - relative_base;
 379                                overflow = (offset < 0 || offset > UINT_MAX);
 380                        } else if (symbol_absolute(&table[i])) {
 381                                offset = table[i].addr;
 382                                overflow = (offset < 0 || offset > INT_MAX);
 383                        } else {
 384                                offset = relative_base - table[i].addr - 1;
 385                                overflow = (offset < INT_MIN || offset >= 0);
 386                        }
 387                        if (overflow) {
 388                                fprintf(stderr, "kallsyms failure: "
 389                                        "%s symbol value %#llx out of range in relative mode\n",
 390                                        symbol_absolute(&table[i]) ? "absolute" : "relative",
 391                                        table[i].addr);
 392                                exit(EXIT_FAILURE);
 393                        }
 394                        printf("\t.long\t%#x\n", (int)offset);
 395                } else if (!symbol_absolute(&table[i])) {
 396                        if (_text <= table[i].addr)
 397                                printf("\tPTR\t_text + %#llx\n",
 398                                        table[i].addr - _text);
 399                        else
 400                                printf("\tPTR\t_text - %#llx\n",
 401                                        _text - table[i].addr);
 402                } else {
 403                        printf("\tPTR\t%#llx\n", table[i].addr);
 404                }
 405        }
 406        printf("\n");
 407
 408        if (base_relative) {
 409                output_label("kallsyms_relative_base");
 410                printf("\tPTR\t_text - %#llx\n", _text - relative_base);
 411                printf("\n");
 412        }
 413
 414        output_label("kallsyms_num_syms");
 415        printf("\tPTR\t%d\n", table_cnt);
 416        printf("\n");
 417
 418        /* table of offset markers, that give the offset in the compressed stream
 419         * every 256 symbols */
 420        markers = malloc(sizeof(unsigned int) * ((table_cnt + 255) / 256));
 421        if (!markers) {
 422                fprintf(stderr, "kallsyms failure: "
 423                        "unable to allocate required memory\n");
 424                exit(EXIT_FAILURE);
 425        }
 426
 427        output_label("kallsyms_names");
 428        off = 0;
 429        for (i = 0; i < table_cnt; i++) {
 430                if ((i & 0xFF) == 0)
 431                        markers[i >> 8] = off;
 432
 433                printf("\t.byte 0x%02x", table[i].len);
 434                for (k = 0; k < table[i].len; k++)
 435                        printf(", 0x%02x", table[i].sym[k]);
 436                printf("\n");
 437
 438                off += table[i].len + 1;
 439        }
 440        printf("\n");
 441
 442        output_label("kallsyms_markers");
 443        for (i = 0; i < ((table_cnt + 255) >> 8); i++)
 444                printf("\tPTR\t%d\n", markers[i]);
 445        printf("\n");
 446
 447        free(markers);
 448
 449        output_label("kallsyms_token_table");
 450        off = 0;
 451        for (i = 0; i < 256; i++) {
 452                best_idx[i] = off;
 453                expand_symbol(best_table[i], best_table_len[i], buf);
 454                printf("\t.asciz\t\"%s\"\n", buf);
 455                off += strlen(buf) + 1;
 456        }
 457        printf("\n");
 458
 459        output_label("kallsyms_token_index");
 460        for (i = 0; i < 256; i++)
 461                printf("\t.short\t%d\n", best_idx[i]);
 462        printf("\n");
 463}
 464
 465
 466/* table lookup compression functions */
 467
 468/* count all the possible tokens in a symbol */
 469static void learn_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/* decrease the count for all the possible tokens in a symbol */
 478static void forget_symbol(unsigned char *symbol, int len)
 479{
 480        int i;
 481
 482        for (i = 0; i < len - 1; i++)
 483                token_profit[ symbol[i] + (symbol[i + 1] << 8) ]--;
 484}
 485
 486/* remove all the invalid symbols from the table and do the initial token count */
 487static void build_initial_tok_table(void)
 488{
 489        unsigned int i, pos;
 490
 491        pos = 0;
 492        for (i = 0; i < table_cnt; i++) {
 493                if ( symbol_valid(&table[i]) ) {
 494                        if (pos != i)
 495                                table[pos] = table[i];
 496                        learn_symbol(table[pos].sym, table[pos].len);
 497                        pos++;
 498                }
 499        }
 500        table_cnt = pos;
 501}
 502
 503static void *find_token(unsigned char *str, int len, unsigned char *token)
 504{
 505        int i;
 506
 507        for (i = 0; i < len - 1; i++) {
 508                if (str[i] == token[0] && str[i+1] == token[1])
 509                        return &str[i];
 510        }
 511        return NULL;
 512}
 513
 514/* replace a given token in all the valid symbols. Use the sampled symbols
 515 * to update the counts */
 516static void compress_symbols(unsigned char *str, int idx)
 517{
 518        unsigned int i, len, size;
 519        unsigned char *p1, *p2;
 520
 521        for (i = 0; i < table_cnt; i++) {
 522
 523                len = table[i].len;
 524                p1 = table[i].sym;
 525
 526                /* find the token on the symbol */
 527                p2 = find_token(p1, len, str);
 528                if (!p2) continue;
 529
 530                /* decrease the counts for this symbol's tokens */
 531                forget_symbol(table[i].sym, len);
 532
 533                size = len;
 534
 535                do {
 536                        *p2 = idx;
 537                        p2++;
 538                        size -= (p2 - p1);
 539                        memmove(p2, p2 + 1, size);
 540                        p1 = p2;
 541                        len--;
 542
 543                        if (size < 2) break;
 544
 545                        /* find the token on the symbol */
 546                        p2 = find_token(p1, size, str);
 547
 548                } while (p2);
 549
 550                table[i].len = len;
 551
 552                /* increase the counts for this symbol's new tokens */
 553                learn_symbol(table[i].sym, len);
 554        }
 555}
 556
 557/* search the token with the maximum profit */
 558static int find_best_token(void)
 559{
 560        int i, best, bestprofit;
 561
 562        bestprofit=-10000;
 563        best = 0;
 564
 565        for (i = 0; i < 0x10000; i++) {
 566                if (token_profit[i] > bestprofit) {
 567                        best = i;
 568                        bestprofit = token_profit[i];
 569                }
 570        }
 571        return best;
 572}
 573
 574/* this is the core of the algorithm: calculate the "best" table */
 575static void optimize_result(void)
 576{
 577        int i, best;
 578
 579        /* using the '\0' symbol last allows compress_symbols to use standard
 580         * fast string functions */
 581        for (i = 255; i >= 0; i--) {
 582
 583                /* if this table slot is empty (it is not used by an actual
 584                 * original char code */
 585                if (!best_table_len[i]) {
 586
 587                        /* find the token with the breates profit value */
 588                        best = find_best_token();
 589                        if (token_profit[best] == 0)
 590                                break;
 591
 592                        /* place it in the "best" table */
 593                        best_table_len[i] = 2;
 594                        best_table[i][0] = best & 0xFF;
 595                        best_table[i][1] = (best >> 8) & 0xFF;
 596
 597                        /* replace this token in all the valid symbols */
 598                        compress_symbols(best_table[i], i);
 599                }
 600        }
 601}
 602
 603/* start by placing the symbols that are actually used on the table */
 604static void insert_real_symbols_in_table(void)
 605{
 606        unsigned int i, j, c;
 607
 608        memset(best_table, 0, sizeof(best_table));
 609        memset(best_table_len, 0, sizeof(best_table_len));
 610
 611        for (i = 0; i < table_cnt; i++) {
 612                for (j = 0; j < table[i].len; j++) {
 613                        c = table[i].sym[j];
 614                        best_table[c][0]=c;
 615                        best_table_len[c]=1;
 616                }
 617        }
 618}
 619
 620static void optimize_token_table(void)
 621{
 622        build_initial_tok_table();
 623
 624        insert_real_symbols_in_table();
 625
 626        /* When valid symbol is not registered, exit to error */
 627        if (!table_cnt) {
 628                fprintf(stderr, "No valid symbol.\n");
 629                exit(1);
 630        }
 631
 632        optimize_result();
 633}
 634
 635/* guess for "linker script provide" symbol */
 636static int may_be_linker_script_provide_symbol(const struct sym_entry *se)
 637{
 638        const char *symbol = (char *)se->sym + 1;
 639        int len = se->len - 1;
 640
 641        if (len < 8)
 642                return 0;
 643
 644        if (symbol[0] != '_' || symbol[1] != '_')
 645                return 0;
 646
 647        /* __start_XXXXX */
 648        if (!memcmp(symbol + 2, "start_", 6))
 649                return 1;
 650
 651        /* __stop_XXXXX */
 652        if (!memcmp(symbol + 2, "stop_", 5))
 653                return 1;
 654
 655        /* __end_XXXXX */
 656        if (!memcmp(symbol + 2, "end_", 4))
 657                return 1;
 658
 659        /* __XXXXX_start */
 660        if (!memcmp(symbol + len - 6, "_start", 6))
 661                return 1;
 662
 663        /* __XXXXX_end */
 664        if (!memcmp(symbol + len - 4, "_end", 4))
 665                return 1;
 666
 667        return 0;
 668}
 669
 670static int prefix_underscores_count(const char *str)
 671{
 672        const char *tail = str;
 673
 674        while (*tail == '_')
 675                tail++;
 676
 677        return tail - str;
 678}
 679
 680static int compare_symbols(const void *a, const void *b)
 681{
 682        const struct sym_entry *sa;
 683        const struct sym_entry *sb;
 684        int wa, wb;
 685
 686        sa = a;
 687        sb = b;
 688
 689        /* sort by address first */
 690        if (sa->addr > sb->addr)
 691                return 1;
 692        if (sa->addr < sb->addr)
 693                return -1;
 694
 695        /* sort by "weakness" type */
 696        wa = (sa->sym[0] == 'w') || (sa->sym[0] == 'W');
 697        wb = (sb->sym[0] == 'w') || (sb->sym[0] == 'W');
 698        if (wa != wb)
 699                return wa - wb;
 700
 701        /* sort by "linker script provide" type */
 702        wa = may_be_linker_script_provide_symbol(sa);
 703        wb = may_be_linker_script_provide_symbol(sb);
 704        if (wa != wb)
 705                return wa - wb;
 706
 707        /* sort by the number of prefix underscores */
 708        wa = prefix_underscores_count((const char *)sa->sym + 1);
 709        wb = prefix_underscores_count((const char *)sb->sym + 1);
 710        if (wa != wb)
 711                return wa - wb;
 712
 713        /* sort by initial order, so that other symbols are left undisturbed */
 714        return sa->start_pos - sb->start_pos;
 715}
 716
 717static void sort_symbols(void)
 718{
 719        qsort(table, table_cnt, sizeof(struct sym_entry), compare_symbols);
 720}
 721
 722static void make_percpus_absolute(void)
 723{
 724        unsigned int i;
 725
 726        for (i = 0; i < table_cnt; i++)
 727                if (symbol_in_range(&table[i], &percpu_range, 1)) {
 728                        /*
 729                         * Keep the 'A' override for percpu symbols to
 730                         * ensure consistent behavior compared to older
 731                         * versions of this tool.
 732                         */
 733                        table[i].sym[0] = 'A';
 734                        table[i].percpu_absolute = 1;
 735                }
 736}
 737
 738/* find the minimum non-absolute symbol address */
 739static void record_relative_base(void)
 740{
 741        unsigned int i;
 742
 743        relative_base = -1ULL;
 744        for (i = 0; i < table_cnt; i++)
 745                if (!symbol_absolute(&table[i]) &&
 746                    table[i].addr < relative_base)
 747                        relative_base = table[i].addr;
 748}
 749
 750int main(int argc, char **argv)
 751{
 752        if (argc >= 2) {
 753                int i;
 754                for (i = 1; i < argc; i++) {
 755                        if(strcmp(argv[i], "--all-symbols") == 0)
 756                                all_symbols = 1;
 757                        else if (strcmp(argv[i], "--absolute-percpu") == 0)
 758                                absolute_percpu = 1;
 759                        else if (strncmp(argv[i], "--symbol-prefix=", 16) == 0) {
 760                                char *p = &argv[i][16];
 761                                /* skip quote */
 762                                if ((*p == '"' && *(p+2) == '"') || (*p == '\'' && *(p+2) == '\''))
 763                                        p++;
 764                                symbol_prefix_char = *p;
 765                        } else if (strcmp(argv[i], "--base-relative") == 0)
 766                                base_relative = 1;
 767                        else
 768                                usage();
 769                }
 770        } else if (argc != 1)
 771                usage();
 772
 773        read_map(stdin);
 774        if (absolute_percpu)
 775                make_percpus_absolute();
 776        if (base_relative)
 777                record_relative_base();
 778        sort_symbols();
 779        optimize_token_table();
 780        write_src();
 781
 782        return 0;
 783}
 784