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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 | ||
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 | { "_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 | ||
57 | static struct addr_range percpu_range = { | |
58 | "__per_cpu_start", "__per_cpu_end", -1ULL, 0 | |
59 | }; | |
60 | ||
61 | static struct sym_entry *table; | |
62 | static unsigned int table_size, table_cnt; | |
63 | static int all_symbols = 0; | |
64 | static int absolute_percpu = 0; | |
65 | static char symbol_prefix_char = '\0'; | |
66 | static int base_relative = 0; | |
67 | ||
68 | int token_profit[0x10000]; | |
69 | ||
70 | /* the table that holds the result of the compression */ | |
71 | unsigned char best_table[256][2]; | |
72 | unsigned char best_table_len[256]; | |
73 | ||
74 | ||
75 | static 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 $d. | |
87 | */ | |
88 | static inline int is_arm_mapping_symbol(const char *str) | |
89 | { | |
90 | return str[0] == '$' && strchr("axtd", str[1]) | |
91 | && (str[2] == '\0' || str[2] == '.'); | |
92 | } | |
93 | ||
94 | static 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 | ||
115 | static 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 | ||
185 | static 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 | ||
201 | static 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 | ||
273 | static 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 | ||
291 | static 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 */ | |
306 | static 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 | ||
331 | static int symbol_absolute(struct sym_entry *s) | |
332 | { | |
333 | return s->percpu_absolute; | |
334 | } | |
335 | ||
336 | static 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 */ | |
469 | static 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 */ | |
478 | static 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 */ | |
487 | static 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 | ||
503 | static 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 */ | |
516 | static 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 */ | |
558 | static 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 */ | |
575 | static 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 */ | |
604 | static 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 | ||
620 | static 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 */ | |
636 | static 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 | ||
670 | static 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 | ||
680 | static 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 | ||
717 | static void sort_symbols(void) | |
718 | { | |
719 | qsort(table, table_cnt, sizeof(struct sym_entry), compare_symbols); | |
720 | } | |
721 | ||
722 | static 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 */ | |
739 | static 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 | ||
750 | int 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 | } |