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: kallsyms [--all-symbols] [--absolute-percpu] 9 * [--base-relative] [--lto-clang] in.map > out.S 10 * 11 * Table compression uses all the unused char codes on the symbols and 12 * maps these to the most used substrings (tokens). For instance, it might 13 * map char code 0xF7 to represent "write_" and then in every symbol where 14 * "write_" appears it can be replaced by 0xF7, saving 5 bytes. 15 * The used codes themselves are also placed in the table so that the 16 * decompresion can work without "special cases". 17 * Applied to kernel symbols, this usually produces a compression ratio 18 * of about 50%. 19 * 20 */ 21 22 #include <errno.h> 23 #include <getopt.h> 24 #include <stdbool.h> 25 #include <stdio.h> 26 #include <stdlib.h> 27 #include <string.h> 28 #include <ctype.h> 29 #include <limits.h> 30 31 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0])) 32 33 #define KSYM_NAME_LEN 512 34 35 struct sym_entry { 36 unsigned long long addr; 37 unsigned int len; 38 unsigned int seq; 39 unsigned int start_pos; 40 unsigned int percpu_absolute; 41 unsigned char sym[]; 42 }; 43 44 struct addr_range { 45 const char *start_sym, *end_sym; 46 unsigned long long start, end; 47 }; 48 49 static unsigned long long _text; 50 static unsigned long long relative_base; 51 static struct addr_range text_ranges[] = { 52 { "_stext", "_etext" }, 53 { "_sinittext", "_einittext" }, 54 }; 55 #define text_range_text (&text_ranges[0]) 56 #define text_range_inittext (&text_ranges[1]) 57 58 static struct addr_range percpu_range = { 59 "__per_cpu_start", "__per_cpu_end", -1ULL, 0 60 }; 61 62 static struct sym_entry **table; 63 static unsigned int table_size, table_cnt; 64 static int all_symbols; 65 static int absolute_percpu; 66 static int base_relative; 67 static int lto_clang; 68 69 static int token_profit[0x10000]; 70 71 /* the table that holds the result of the compression */ 72 static unsigned char best_table[256][2]; 73 static unsigned char best_table_len[256]; 74 75 76 static void usage(void) 77 { 78 fprintf(stderr, "Usage: kallsyms [--all-symbols] [--absolute-percpu] " 79 "[--base-relative] [--lto-clang] in.map > out.S\n"); 80 exit(1); 81 } 82 83 static char *sym_name(const struct sym_entry *s) 84 { 85 return (char *)s->sym + 1; 86 } 87 88 static bool is_ignored_symbol(const char *name, char type) 89 { 90 if (type == 'u' || type == 'n') 91 return true; 92 93 if (toupper(type) == 'A') { 94 /* Keep these useful absolute symbols */ 95 if (strcmp(name, "__kernel_syscall_via_break") && 96 strcmp(name, "__kernel_syscall_via_epc") && 97 strcmp(name, "__kernel_sigtramp") && 98 strcmp(name, "__gp")) 99 return true; 100 } 101 102 return false; 103 } 104 105 static void check_symbol_range(const char *sym, unsigned long long addr, 106 struct addr_range *ranges, int entries) 107 { 108 size_t i; 109 struct addr_range *ar; 110 111 for (i = 0; i < entries; ++i) { 112 ar = &ranges[i]; 113 114 if (strcmp(sym, ar->start_sym) == 0) { 115 ar->start = addr; 116 return; 117 } else if (strcmp(sym, ar->end_sym) == 0) { 118 ar->end = addr; 119 return; 120 } 121 } 122 } 123 124 static struct sym_entry *read_symbol(FILE *in, char **buf, size_t *buf_len) 125 { 126 char *name, type, *p; 127 unsigned long long addr; 128 size_t len; 129 ssize_t readlen; 130 struct sym_entry *sym; 131 132 readlen = getline(buf, buf_len, in); 133 if (readlen < 0) { 134 if (errno) { 135 perror("read_symbol"); 136 exit(EXIT_FAILURE); 137 } 138 return NULL; 139 } 140 141 if ((*buf)[readlen - 1] == '\n') 142 (*buf)[readlen - 1] = 0; 143 144 addr = strtoull(*buf, &p, 16); 145 146 if (*buf == p || *p++ != ' ' || !isascii((type = *p++)) || *p++ != ' ') { 147 fprintf(stderr, "line format error\n"); 148 exit(EXIT_FAILURE); 149 } 150 151 name = p; 152 len = strlen(name); 153 154 if (len >= KSYM_NAME_LEN) { 155 fprintf(stderr, "Symbol %s too long for kallsyms (%zu >= %d).\n" 156 "Please increase KSYM_NAME_LEN both in kernel and kallsyms.c\n", 157 name, len, KSYM_NAME_LEN); 158 return NULL; 159 } 160 161 if (strcmp(name, "_text") == 0) 162 _text = addr; 163 164 /* Ignore most absolute/undefined (?) symbols. */ 165 if (is_ignored_symbol(name, type)) 166 return NULL; 167 168 check_symbol_range(name, addr, text_ranges, ARRAY_SIZE(text_ranges)); 169 check_symbol_range(name, addr, &percpu_range, 1); 170 171 /* include the type field in the symbol name, so that it gets 172 * compressed together */ 173 len++; 174 175 sym = malloc(sizeof(*sym) + len + 1); 176 if (!sym) { 177 fprintf(stderr, "kallsyms failure: " 178 "unable to allocate required amount of memory\n"); 179 exit(EXIT_FAILURE); 180 } 181 sym->addr = addr; 182 sym->len = len; 183 sym->sym[0] = type; 184 strcpy(sym_name(sym), name); 185 sym->percpu_absolute = 0; 186 187 return sym; 188 } 189 190 static int symbol_in_range(const struct sym_entry *s, 191 const struct addr_range *ranges, int entries) 192 { 193 size_t i; 194 const struct addr_range *ar; 195 196 for (i = 0; i < entries; ++i) { 197 ar = &ranges[i]; 198 199 if (s->addr >= ar->start && s->addr <= ar->end) 200 return 1; 201 } 202 203 return 0; 204 } 205 206 static int symbol_valid(const struct sym_entry *s) 207 { 208 const char *name = sym_name(s); 209 210 /* if --all-symbols is not specified, then symbols outside the text 211 * and inittext sections are discarded */ 212 if (!all_symbols) { 213 if (symbol_in_range(s, text_ranges, 214 ARRAY_SIZE(text_ranges)) == 0) 215 return 0; 216 /* Corner case. Discard any symbols with the same value as 217 * _etext _einittext; they can move between pass 1 and 2 when 218 * the kallsyms data are added. If these symbols move then 219 * they may get dropped in pass 2, which breaks the kallsyms 220 * rules. 221 */ 222 if ((s->addr == text_range_text->end && 223 strcmp(name, text_range_text->end_sym)) || 224 (s->addr == text_range_inittext->end && 225 strcmp(name, text_range_inittext->end_sym))) 226 return 0; 227 } 228 229 return 1; 230 } 231 232 /* remove all the invalid symbols from the table */ 233 static void shrink_table(void) 234 { 235 unsigned int i, pos; 236 237 pos = 0; 238 for (i = 0; i < table_cnt; i++) { 239 if (symbol_valid(table[i])) { 240 if (pos != i) 241 table[pos] = table[i]; 242 pos++; 243 } else { 244 free(table[i]); 245 } 246 } 247 table_cnt = pos; 248 249 /* When valid symbol is not registered, exit to error */ 250 if (!table_cnt) { 251 fprintf(stderr, "No valid symbol.\n"); 252 exit(1); 253 } 254 } 255 256 static void read_map(const char *in) 257 { 258 FILE *fp; 259 struct sym_entry *sym; 260 char *buf = NULL; 261 size_t buflen = 0; 262 263 fp = fopen(in, "r"); 264 if (!fp) { 265 perror(in); 266 exit(1); 267 } 268 269 while (!feof(fp)) { 270 sym = read_symbol(fp, &buf, &buflen); 271 if (!sym) 272 continue; 273 274 sym->start_pos = table_cnt; 275 276 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 fclose(fp); 282 exit (1); 283 } 284 } 285 286 table[table_cnt++] = sym; 287 } 288 289 free(buf); 290 fclose(fp); 291 } 292 293 static void output_label(const char *label) 294 { 295 printf(".globl %s\n", label); 296 printf("\tALGN\n"); 297 printf("%s:\n", label); 298 } 299 300 /* Provide proper symbols relocatability by their '_text' relativeness. */ 301 static void output_address(unsigned long long addr) 302 { 303 if (_text <= addr) 304 printf("\tPTR\t_text + %#llx\n", addr - _text); 305 else 306 printf("\tPTR\t_text - %#llx\n", _text - addr); 307 } 308 309 /* uncompress a compressed symbol. When this function is called, the best table 310 * might still be compressed itself, so the function needs to be recursive */ 311 static int expand_symbol(const unsigned char *data, int len, char *result) 312 { 313 int c, rlen, total=0; 314 315 while (len) { 316 c = *data; 317 /* if the table holds a single char that is the same as the one 318 * we are looking for, then end the search */ 319 if (best_table[c][0]==c && best_table_len[c]==1) { 320 *result++ = c; 321 total++; 322 } else { 323 /* if not, recurse and expand */ 324 rlen = expand_symbol(best_table[c], best_table_len[c], result); 325 total += rlen; 326 result += rlen; 327 } 328 data++; 329 len--; 330 } 331 *result=0; 332 333 return total; 334 } 335 336 static int symbol_absolute(const struct sym_entry *s) 337 { 338 return s->percpu_absolute; 339 } 340 341 static void cleanup_symbol_name(char *s) 342 { 343 char *p; 344 345 /* 346 * ASCII[.] = 2e 347 * ASCII[0-9] = 30,39 348 * ASCII[A-Z] = 41,5a 349 * ASCII[_] = 5f 350 * ASCII[a-z] = 61,7a 351 * 352 * As above, replacing the first '.' in ".llvm." with '\0' does not 353 * affect the main sorting, but it helps us with subsorting. 354 */ 355 p = strstr(s, ".llvm."); 356 if (p) 357 *p = '\0'; 358 } 359 360 static int compare_names(const void *a, const void *b) 361 { 362 int ret; 363 const struct sym_entry *sa = *(const struct sym_entry **)a; 364 const struct sym_entry *sb = *(const struct sym_entry **)b; 365 366 ret = strcmp(sym_name(sa), sym_name(sb)); 367 if (!ret) { 368 if (sa->addr > sb->addr) 369 return 1; 370 else if (sa->addr < sb->addr) 371 return -1; 372 373 /* keep old order */ 374 return (int)(sa->seq - sb->seq); 375 } 376 377 return ret; 378 } 379 380 static void sort_symbols_by_name(void) 381 { 382 qsort(table, table_cnt, sizeof(table[0]), compare_names); 383 } 384 385 static void write_src(void) 386 { 387 unsigned int i, k, off; 388 unsigned int best_idx[256]; 389 unsigned int *markers; 390 char buf[KSYM_NAME_LEN]; 391 392 printf("#include <asm/bitsperlong.h>\n"); 393 printf("#if BITS_PER_LONG == 64\n"); 394 printf("#define PTR .quad\n"); 395 printf("#define ALGN .balign 8\n"); 396 printf("#else\n"); 397 printf("#define PTR .long\n"); 398 printf("#define ALGN .balign 4\n"); 399 printf("#endif\n"); 400 401 printf("\t.section .rodata, \"a\"\n"); 402 403 output_label("kallsyms_num_syms"); 404 printf("\t.long\t%u\n", table_cnt); 405 printf("\n"); 406 407 /* table of offset markers, that give the offset in the compressed stream 408 * every 256 symbols */ 409 markers = malloc(sizeof(unsigned int) * ((table_cnt + 255) / 256)); 410 if (!markers) { 411 fprintf(stderr, "kallsyms failure: " 412 "unable to allocate required memory\n"); 413 exit(EXIT_FAILURE); 414 } 415 416 output_label("kallsyms_names"); 417 off = 0; 418 for (i = 0; i < table_cnt; i++) { 419 if ((i & 0xFF) == 0) 420 markers[i >> 8] = off; 421 table[i]->seq = i; 422 423 /* There cannot be any symbol of length zero. */ 424 if (table[i]->len == 0) { 425 fprintf(stderr, "kallsyms failure: " 426 "unexpected zero symbol length\n"); 427 exit(EXIT_FAILURE); 428 } 429 430 /* Only lengths that fit in up-to-two-byte ULEB128 are supported. */ 431 if (table[i]->len > 0x3FFF) { 432 fprintf(stderr, "kallsyms failure: " 433 "unexpected huge symbol length\n"); 434 exit(EXIT_FAILURE); 435 } 436 437 /* Encode length with ULEB128. */ 438 if (table[i]->len <= 0x7F) { 439 /* Most symbols use a single byte for the length. */ 440 printf("\t.byte 0x%02x", table[i]->len); 441 off += table[i]->len + 1; 442 } else { 443 /* "Big" symbols use two bytes. */ 444 printf("\t.byte 0x%02x, 0x%02x", 445 (table[i]->len & 0x7F) | 0x80, 446 (table[i]->len >> 7) & 0x7F); 447 off += table[i]->len + 2; 448 } 449 for (k = 0; k < table[i]->len; k++) 450 printf(", 0x%02x", table[i]->sym[k]); 451 printf("\n"); 452 } 453 printf("\n"); 454 455 /* 456 * Now that we wrote out the compressed symbol names, restore the 457 * original names, which are needed in some of the later steps. 458 */ 459 for (i = 0; i < table_cnt; i++) { 460 expand_symbol(table[i]->sym, table[i]->len, buf); 461 strcpy((char *)table[i]->sym, buf); 462 } 463 464 output_label("kallsyms_markers"); 465 for (i = 0; i < ((table_cnt + 255) >> 8); i++) 466 printf("\t.long\t%u\n", markers[i]); 467 printf("\n"); 468 469 free(markers); 470 471 output_label("kallsyms_token_table"); 472 off = 0; 473 for (i = 0; i < 256; i++) { 474 best_idx[i] = off; 475 expand_symbol(best_table[i], best_table_len[i], buf); 476 printf("\t.asciz\t\"%s\"\n", buf); 477 off += strlen(buf) + 1; 478 } 479 printf("\n"); 480 481 output_label("kallsyms_token_index"); 482 for (i = 0; i < 256; i++) 483 printf("\t.short\t%d\n", best_idx[i]); 484 printf("\n"); 485 486 if (!base_relative) 487 output_label("kallsyms_addresses"); 488 else 489 output_label("kallsyms_offsets"); 490 491 for (i = 0; i < table_cnt; i++) { 492 if (base_relative) { 493 /* 494 * Use the offset relative to the lowest value 495 * encountered of all relative symbols, and emit 496 * non-relocatable fixed offsets that will be fixed 497 * up at runtime. 498 */ 499 500 long long offset; 501 int overflow; 502 503 if (!absolute_percpu) { 504 offset = table[i]->addr - relative_base; 505 overflow = (offset < 0 || offset > UINT_MAX); 506 } else if (symbol_absolute(table[i])) { 507 offset = table[i]->addr; 508 overflow = (offset < 0 || offset > INT_MAX); 509 } else { 510 offset = relative_base - table[i]->addr - 1; 511 overflow = (offset < INT_MIN || offset >= 0); 512 } 513 if (overflow) { 514 fprintf(stderr, "kallsyms failure: " 515 "%s symbol value %#llx out of range in relative mode\n", 516 symbol_absolute(table[i]) ? "absolute" : "relative", 517 table[i]->addr); 518 exit(EXIT_FAILURE); 519 } 520 printf("\t.long\t%#x /* %s */\n", (int)offset, table[i]->sym); 521 } else if (!symbol_absolute(table[i])) { 522 output_address(table[i]->addr); 523 } else { 524 printf("\tPTR\t%#llx\n", table[i]->addr); 525 } 526 } 527 printf("\n"); 528 529 if (base_relative) { 530 output_label("kallsyms_relative_base"); 531 output_address(relative_base); 532 printf("\n"); 533 } 534 535 if (lto_clang) 536 for (i = 0; i < table_cnt; i++) 537 cleanup_symbol_name((char *)table[i]->sym); 538 539 sort_symbols_by_name(); 540 output_label("kallsyms_seqs_of_names"); 541 for (i = 0; i < table_cnt; i++) 542 printf("\t.byte 0x%02x, 0x%02x, 0x%02x\n", 543 (unsigned char)(table[i]->seq >> 16), 544 (unsigned char)(table[i]->seq >> 8), 545 (unsigned char)(table[i]->seq >> 0)); 546 printf("\n"); 547 } 548 549 550 /* table lookup compression functions */ 551 552 /* count all the possible tokens in a symbol */ 553 static void learn_symbol(const unsigned char *symbol, int len) 554 { 555 int i; 556 557 for (i = 0; i < len - 1; i++) 558 token_profit[ symbol[i] + (symbol[i + 1] << 8) ]++; 559 } 560 561 /* decrease the count for all the possible tokens in a symbol */ 562 static void forget_symbol(const unsigned char *symbol, int len) 563 { 564 int i; 565 566 for (i = 0; i < len - 1; i++) 567 token_profit[ symbol[i] + (symbol[i + 1] << 8) ]--; 568 } 569 570 /* do the initial token count */ 571 static void build_initial_token_table(void) 572 { 573 unsigned int i; 574 575 for (i = 0; i < table_cnt; i++) 576 learn_symbol(table[i]->sym, table[i]->len); 577 } 578 579 static unsigned char *find_token(unsigned char *str, int len, 580 const unsigned char *token) 581 { 582 int i; 583 584 for (i = 0; i < len - 1; i++) { 585 if (str[i] == token[0] && str[i+1] == token[1]) 586 return &str[i]; 587 } 588 return NULL; 589 } 590 591 /* replace a given token in all the valid symbols. Use the sampled symbols 592 * to update the counts */ 593 static void compress_symbols(const unsigned char *str, int idx) 594 { 595 unsigned int i, len, size; 596 unsigned char *p1, *p2; 597 598 for (i = 0; i < table_cnt; i++) { 599 600 len = table[i]->len; 601 p1 = table[i]->sym; 602 603 /* find the token on the symbol */ 604 p2 = find_token(p1, len, str); 605 if (!p2) continue; 606 607 /* decrease the counts for this symbol's tokens */ 608 forget_symbol(table[i]->sym, len); 609 610 size = len; 611 612 do { 613 *p2 = idx; 614 p2++; 615 size -= (p2 - p1); 616 memmove(p2, p2 + 1, size); 617 p1 = p2; 618 len--; 619 620 if (size < 2) break; 621 622 /* find the token on the symbol */ 623 p2 = find_token(p1, size, str); 624 625 } while (p2); 626 627 table[i]->len = len; 628 629 /* increase the counts for this symbol's new tokens */ 630 learn_symbol(table[i]->sym, len); 631 } 632 } 633 634 /* search the token with the maximum profit */ 635 static int find_best_token(void) 636 { 637 int i, best, bestprofit; 638 639 bestprofit=-10000; 640 best = 0; 641 642 for (i = 0; i < 0x10000; i++) { 643 if (token_profit[i] > bestprofit) { 644 best = i; 645 bestprofit = token_profit[i]; 646 } 647 } 648 return best; 649 } 650 651 /* this is the core of the algorithm: calculate the "best" table */ 652 static void optimize_result(void) 653 { 654 int i, best; 655 656 /* using the '\0' symbol last allows compress_symbols to use standard 657 * fast string functions */ 658 for (i = 255; i >= 0; i--) { 659 660 /* if this table slot is empty (it is not used by an actual 661 * original char code */ 662 if (!best_table_len[i]) { 663 664 /* find the token with the best profit value */ 665 best = find_best_token(); 666 if (token_profit[best] == 0) 667 break; 668 669 /* place it in the "best" table */ 670 best_table_len[i] = 2; 671 best_table[i][0] = best & 0xFF; 672 best_table[i][1] = (best >> 8) & 0xFF; 673 674 /* replace this token in all the valid symbols */ 675 compress_symbols(best_table[i], i); 676 } 677 } 678 } 679 680 /* start by placing the symbols that are actually used on the table */ 681 static void insert_real_symbols_in_table(void) 682 { 683 unsigned int i, j, c; 684 685 for (i = 0; i < table_cnt; i++) { 686 for (j = 0; j < table[i]->len; j++) { 687 c = table[i]->sym[j]; 688 best_table[c][0]=c; 689 best_table_len[c]=1; 690 } 691 } 692 } 693 694 static void optimize_token_table(void) 695 { 696 build_initial_token_table(); 697 698 insert_real_symbols_in_table(); 699 700 optimize_result(); 701 } 702 703 /* guess for "linker script provide" symbol */ 704 static int may_be_linker_script_provide_symbol(const struct sym_entry *se) 705 { 706 const char *symbol = sym_name(se); 707 int len = se->len - 1; 708 709 if (len < 8) 710 return 0; 711 712 if (symbol[0] != '_' || symbol[1] != '_') 713 return 0; 714 715 /* __start_XXXXX */ 716 if (!memcmp(symbol + 2, "start_", 6)) 717 return 1; 718 719 /* __stop_XXXXX */ 720 if (!memcmp(symbol + 2, "stop_", 5)) 721 return 1; 722 723 /* __end_XXXXX */ 724 if (!memcmp(symbol + 2, "end_", 4)) 725 return 1; 726 727 /* __XXXXX_start */ 728 if (!memcmp(symbol + len - 6, "_start", 6)) 729 return 1; 730 731 /* __XXXXX_end */ 732 if (!memcmp(symbol + len - 4, "_end", 4)) 733 return 1; 734 735 return 0; 736 } 737 738 static int compare_symbols(const void *a, const void *b) 739 { 740 const struct sym_entry *sa = *(const struct sym_entry **)a; 741 const struct sym_entry *sb = *(const struct sym_entry **)b; 742 int wa, wb; 743 744 /* sort by address first */ 745 if (sa->addr > sb->addr) 746 return 1; 747 if (sa->addr < sb->addr) 748 return -1; 749 750 /* sort by "weakness" type */ 751 wa = (sa->sym[0] == 'w') || (sa->sym[0] == 'W'); 752 wb = (sb->sym[0] == 'w') || (sb->sym[0] == 'W'); 753 if (wa != wb) 754 return wa - wb; 755 756 /* sort by "linker script provide" type */ 757 wa = may_be_linker_script_provide_symbol(sa); 758 wb = may_be_linker_script_provide_symbol(sb); 759 if (wa != wb) 760 return wa - wb; 761 762 /* sort by the number of prefix underscores */ 763 wa = strspn(sym_name(sa), "_"); 764 wb = strspn(sym_name(sb), "_"); 765 if (wa != wb) 766 return wa - wb; 767 768 /* sort by initial order, so that other symbols are left undisturbed */ 769 return sa->start_pos - sb->start_pos; 770 } 771 772 static void sort_symbols(void) 773 { 774 qsort(table, table_cnt, sizeof(table[0]), compare_symbols); 775 } 776 777 static void make_percpus_absolute(void) 778 { 779 unsigned int i; 780 781 for (i = 0; i < table_cnt; i++) 782 if (symbol_in_range(table[i], &percpu_range, 1)) { 783 /* 784 * Keep the 'A' override for percpu symbols to 785 * ensure consistent behavior compared to older 786 * versions of this tool. 787 */ 788 table[i]->sym[0] = 'A'; 789 table[i]->percpu_absolute = 1; 790 } 791 } 792 793 /* find the minimum non-absolute symbol address */ 794 static void record_relative_base(void) 795 { 796 unsigned int i; 797 798 for (i = 0; i < table_cnt; i++) 799 if (!symbol_absolute(table[i])) { 800 /* 801 * The table is sorted by address. 802 * Take the first non-absolute symbol value. 803 */ 804 relative_base = table[i]->addr; 805 return; 806 } 807 } 808 809 int main(int argc, char **argv) 810 { 811 while (1) { 812 static const struct option long_options[] = { 813 {"all-symbols", no_argument, &all_symbols, 1}, 814 {"absolute-percpu", no_argument, &absolute_percpu, 1}, 815 {"base-relative", no_argument, &base_relative, 1}, 816 {"lto-clang", no_argument, <o_clang, 1}, 817 {}, 818 }; 819 820 int c = getopt_long(argc, argv, "", long_options, NULL); 821 822 if (c == -1) 823 break; 824 if (c != 0) 825 usage(); 826 } 827 828 if (optind >= argc) 829 usage(); 830 831 read_map(argv[optind]); 832 shrink_table(); 833 if (absolute_percpu) 834 make_percpus_absolute(); 835 sort_symbols(); 836 if (base_relative) 837 record_relative_base(); 838 optimize_token_table(); 839 write_src(); 840 841 return 0; 842 } 843