Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | * | |
020925ce | 8 | * Usage: kallsyms [--all-symbols] [--absolute-percpu] in.map > out.S |
1da177e4 | 9 | * |
1da177e4 LT |
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 | ||
1c975da5 | 21 | #include <errno.h> |
aa221f2e | 22 | #include <getopt.h> |
a41333e0 | 23 | #include <stdbool.h> |
1da177e4 LT |
24 | #include <stdio.h> |
25 | #include <stdlib.h> | |
26 | #include <string.h> | |
27 | #include <ctype.h> | |
2213e9a6 | 28 | #include <limits.h> |
1da177e4 | 29 | |
17b1f0de | 30 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0])) |
17b1f0de | 31 | |
b8a94bfb | 32 | #define KSYM_NAME_LEN 512 |
1da177e4 | 33 | |
1da177e4 LT |
34 | struct sym_entry { |
35 | unsigned long long addr; | |
b3dbb4ec | 36 | unsigned int len; |
60443c88 | 37 | unsigned int seq; |
1a7c8d24 | 38 | bool percpu_absolute; |
9d82973e | 39 | unsigned char sym[]; |
1da177e4 LT |
40 | }; |
41 | ||
78eb7159 KC |
42 | struct addr_range { |
43 | const char *start_sym, *end_sym; | |
17b1f0de MF |
44 | unsigned long long start, end; |
45 | }; | |
46 | ||
47 | static unsigned long long _text; | |
2213e9a6 | 48 | static unsigned long long relative_base; |
78eb7159 | 49 | static struct addr_range text_ranges[] = { |
17b1f0de MF |
50 | { "_stext", "_etext" }, |
51 | { "_sinittext", "_einittext" }, | |
17b1f0de MF |
52 | }; |
53 | #define text_range_text (&text_ranges[0]) | |
54 | #define text_range_inittext (&text_ranges[1]) | |
55 | ||
c6bda7c9 RR |
56 | static struct addr_range percpu_range = { |
57 | "__per_cpu_start", "__per_cpu_end", -1ULL, 0 | |
58 | }; | |
59 | ||
8d605269 | 60 | static struct sym_entry **table; |
b3dbb4ec | 61 | static unsigned int table_size, table_cnt; |
831362fc MY |
62 | static int all_symbols; |
63 | static int absolute_percpu; | |
1da177e4 | 64 | |
f43e9daa | 65 | static int token_profit[0x10000]; |
1da177e4 LT |
66 | |
67 | /* the table that holds the result of the compression */ | |
f43e9daa MY |
68 | static unsigned char best_table[256][2]; |
69 | static unsigned char best_table_len[256]; | |
1da177e4 LT |
70 | |
71 | ||
b3dbb4ec | 72 | static void usage(void) |
1da177e4 | 73 | { |
020925ce | 74 | fprintf(stderr, "Usage: kallsyms [--all-symbols] [--absolute-percpu] in.map > out.S\n"); |
1da177e4 LT |
75 | exit(1); |
76 | } | |
77 | ||
29e55ad3 MY |
78 | static char *sym_name(const struct sym_entry *s) |
79 | { | |
80 | return (char *)s->sym + 1; | |
81 | } | |
82 | ||
a41333e0 MY |
83 | static bool is_ignored_symbol(const char *name, char type) |
84 | { | |
a7b00a18 | 85 | if (type == 'u' || type == 'n') |
887df76d MY |
86 | return true; |
87 | ||
88 | if (toupper(type) == 'A') { | |
89 | /* Keep these useful absolute symbols */ | |
90 | if (strcmp(name, "__kernel_syscall_via_break") && | |
91 | strcmp(name, "__kernel_syscall_via_epc") && | |
92 | strcmp(name, "__kernel_sigtramp") && | |
93 | strcmp(name, "__gp")) | |
94 | return true; | |
95 | } | |
96 | ||
a41333e0 MY |
97 | return false; |
98 | } | |
99 | ||
b6233d0d MY |
100 | static void check_symbol_range(const char *sym, unsigned long long addr, |
101 | struct addr_range *ranges, int entries) | |
17b1f0de MF |
102 | { |
103 | size_t i; | |
78eb7159 | 104 | struct addr_range *ar; |
17b1f0de | 105 | |
78eb7159 KC |
106 | for (i = 0; i < entries; ++i) { |
107 | ar = &ranges[i]; | |
17b1f0de | 108 | |
78eb7159 KC |
109 | if (strcmp(sym, ar->start_sym) == 0) { |
110 | ar->start = addr; | |
b6233d0d | 111 | return; |
78eb7159 KC |
112 | } else if (strcmp(sym, ar->end_sym) == 0) { |
113 | ar->end = addr; | |
b6233d0d | 114 | return; |
17b1f0de MF |
115 | } |
116 | } | |
17b1f0de MF |
117 | } |
118 | ||
1c975da5 | 119 | static struct sym_entry *read_symbol(FILE *in, char **buf, size_t *buf_len) |
1da177e4 | 120 | { |
1c975da5 | 121 | char *name, type, *p; |
8d605269 | 122 | unsigned long long addr; |
1c975da5 MY |
123 | size_t len; |
124 | ssize_t readlen; | |
8d605269 | 125 | struct sym_entry *sym; |
1da177e4 | 126 | |
23835308 | 127 | errno = 0; |
1c975da5 MY |
128 | readlen = getline(buf, buf_len, in); |
129 | if (readlen < 0) { | |
130 | if (errno) { | |
131 | perror("read_symbol"); | |
132 | exit(EXIT_FAILURE); | |
133 | } | |
8d605269 | 134 | return NULL; |
1da177e4 | 135 | } |
1c975da5 MY |
136 | |
137 | if ((*buf)[readlen - 1] == '\n') | |
138 | (*buf)[readlen - 1] = 0; | |
139 | ||
140 | addr = strtoull(*buf, &p, 16); | |
141 | ||
142 | if (*buf == p || *p++ != ' ' || !isascii((type = *p++)) || *p++ != ' ') { | |
143 | fprintf(stderr, "line format error\n"); | |
144 | exit(EXIT_FAILURE); | |
145 | } | |
146 | ||
147 | name = p; | |
148 | len = strlen(name); | |
149 | ||
150 | if (len >= KSYM_NAME_LEN) { | |
6db2983c | 151 | fprintf(stderr, "Symbol %s too long for kallsyms (%zu >= %d).\n" |
bb66fc67 | 152 | "Please increase KSYM_NAME_LEN both in kernel and kallsyms.c\n", |
1c975da5 | 153 | name, len, KSYM_NAME_LEN); |
8d605269 | 154 | return NULL; |
f3462aa9 | 155 | } |
1da177e4 | 156 | |
be9f6133 | 157 | if (strcmp(name, "_text") == 0) |
8d605269 | 158 | _text = addr; |
b6233d0d | 159 | |
7883a143 MP |
160 | /* Ignore most absolute/undefined (?) symbols. */ |
161 | if (is_ignored_symbol(name, type)) | |
162 | return NULL; | |
163 | ||
8d605269 MY |
164 | check_symbol_range(name, addr, text_ranges, ARRAY_SIZE(text_ranges)); |
165 | check_symbol_range(name, addr, &percpu_range, 1); | |
1da177e4 LT |
166 | |
167 | /* include the type field in the symbol name, so that it gets | |
168 | * compressed together */ | |
1c975da5 | 169 | len++; |
8d605269 | 170 | |
9d1b3895 | 171 | sym = malloc(sizeof(*sym) + len + 1); |
8d605269 | 172 | if (!sym) { |
f1a136e0 JJ |
173 | fprintf(stderr, "kallsyms failure: " |
174 | "unable to allocate required amount of memory\n"); | |
175 | exit(EXIT_FAILURE); | |
176 | } | |
8d605269 MY |
177 | sym->addr = addr; |
178 | sym->len = len; | |
179 | sym->sym[0] = type; | |
9d1b3895 | 180 | strcpy(sym_name(sym), name); |
1a7c8d24 | 181 | sym->percpu_absolute = false; |
8c996940 | 182 | |
8d605269 | 183 | return sym; |
1da177e4 LT |
184 | } |
185 | ||
4bfe2b78 MY |
186 | static int symbol_in_range(const struct sym_entry *s, |
187 | const struct addr_range *ranges, int entries) | |
17b1f0de MF |
188 | { |
189 | size_t i; | |
4bfe2b78 | 190 | const struct addr_range *ar; |
17b1f0de | 191 | |
78eb7159 KC |
192 | for (i = 0; i < entries; ++i) { |
193 | ar = &ranges[i]; | |
17b1f0de | 194 | |
78eb7159 | 195 | if (s->addr >= ar->start && s->addr <= ar->end) |
ac6ca5c8 | 196 | return 1; |
17b1f0de MF |
197 | } |
198 | ||
ac6ca5c8 | 199 | return 0; |
17b1f0de MF |
200 | } |
201 | ||
a7f13d0f KO |
202 | static bool string_starts_with(const char *s, const char *prefix) |
203 | { | |
204 | return strncmp(s, prefix, strlen(prefix)) == 0; | |
205 | } | |
206 | ||
4bfe2b78 | 207 | static int symbol_valid(const struct sym_entry *s) |
1da177e4 | 208 | { |
29e55ad3 | 209 | const char *name = sym_name(s); |
bd8b22d2 | 210 | |
1da177e4 LT |
211 | /* if --all-symbols is not specified, then symbols outside the text |
212 | * and inittext sections are discarded */ | |
213 | if (!all_symbols) { | |
a7f13d0f KO |
214 | /* |
215 | * Symbols starting with __start and __stop are used to denote | |
216 | * section boundaries, and should always be included: | |
217 | */ | |
218 | if (string_starts_with(name, "__start_") || | |
219 | string_starts_with(name, "__stop_")) | |
220 | return 1; | |
221 | ||
78eb7159 KC |
222 | if (symbol_in_range(s, text_ranges, |
223 | ARRAY_SIZE(text_ranges)) == 0) | |
1da177e4 LT |
224 | return 0; |
225 | /* Corner case. Discard any symbols with the same value as | |
a3b81113 RG |
226 | * _etext _einittext; they can move between pass 1 and 2 when |
227 | * the kallsyms data are added. If these symbols move then | |
228 | * they may get dropped in pass 2, which breaks the kallsyms | |
229 | * rules. | |
1da177e4 | 230 | */ |
17b1f0de | 231 | if ((s->addr == text_range_text->end && |
29e55ad3 | 232 | strcmp(name, text_range_text->end_sym)) || |
17b1f0de | 233 | (s->addr == text_range_inittext->end && |
29e55ad3 | 234 | strcmp(name, text_range_inittext->end_sym))) |
1da177e4 LT |
235 | return 0; |
236 | } | |
237 | ||
1da177e4 LT |
238 | return 1; |
239 | } | |
240 | ||
5e5c4fa7 MY |
241 | /* remove all the invalid symbols from the table */ |
242 | static void shrink_table(void) | |
243 | { | |
244 | unsigned int i, pos; | |
245 | ||
246 | pos = 0; | |
247 | for (i = 0; i < table_cnt; i++) { | |
8d605269 | 248 | if (symbol_valid(table[i])) { |
5e5c4fa7 MY |
249 | if (pos != i) |
250 | table[pos] = table[i]; | |
251 | pos++; | |
252 | } else { | |
8d605269 | 253 | free(table[i]); |
5e5c4fa7 MY |
254 | } |
255 | } | |
256 | table_cnt = pos; | |
5e5c4fa7 MY |
257 | } |
258 | ||
aa221f2e | 259 | static void read_map(const char *in) |
1da177e4 | 260 | { |
aa221f2e | 261 | FILE *fp; |
8d605269 | 262 | struct sym_entry *sym; |
1c975da5 MY |
263 | char *buf = NULL; |
264 | size_t buflen = 0; | |
8d605269 | 265 | |
aa221f2e MY |
266 | fp = fopen(in, "r"); |
267 | if (!fp) { | |
268 | perror(in); | |
269 | exit(1); | |
270 | } | |
271 | ||
272 | while (!feof(fp)) { | |
1c975da5 | 273 | sym = read_symbol(fp, &buf, &buflen); |
8d605269 MY |
274 | if (!sym) |
275 | continue; | |
276 | ||
1d48f8fe | 277 | sym->seq = table_cnt; |
8d605269 | 278 | |
b3dbb4ec PM |
279 | if (table_cnt >= table_size) { |
280 | table_size += 10000; | |
281 | table = realloc(table, sizeof(*table) * table_size); | |
1da177e4 LT |
282 | if (!table) { |
283 | fprintf(stderr, "out of memory\n"); | |
aa221f2e | 284 | fclose(fp); |
1da177e4 LT |
285 | exit (1); |
286 | } | |
287 | } | |
8d605269 MY |
288 | |
289 | table[table_cnt++] = sym; | |
1da177e4 | 290 | } |
aa221f2e | 291 | |
1c975da5 | 292 | free(buf); |
aa221f2e | 293 | fclose(fp); |
1da177e4 LT |
294 | } |
295 | ||
4bfe2b78 | 296 | static void output_label(const char *label) |
1da177e4 | 297 | { |
534c9f2e | 298 | printf(".globl %s\n", label); |
1da177e4 | 299 | printf("\tALGN\n"); |
534c9f2e | 300 | printf("%s:\n", label); |
1da177e4 LT |
301 | } |
302 | ||
fd2ab2f6 MY |
303 | /* Provide proper symbols relocatability by their '_text' relativeness. */ |
304 | static void output_address(unsigned long long addr) | |
305 | { | |
306 | if (_text <= addr) | |
307 | printf("\tPTR\t_text + %#llx\n", addr - _text); | |
308 | else | |
309 | printf("\tPTR\t_text - %#llx\n", _text - addr); | |
310 | } | |
311 | ||
1da177e4 LT |
312 | /* uncompress a compressed symbol. When this function is called, the best table |
313 | * might still be compressed itself, so the function needs to be recursive */ | |
4bfe2b78 | 314 | static int expand_symbol(const unsigned char *data, int len, char *result) |
1da177e4 LT |
315 | { |
316 | int c, rlen, total=0; | |
317 | ||
318 | while (len) { | |
319 | c = *data; | |
320 | /* if the table holds a single char that is the same as the one | |
321 | * we are looking for, then end the search */ | |
322 | if (best_table[c][0]==c && best_table_len[c]==1) { | |
323 | *result++ = c; | |
324 | total++; | |
325 | } else { | |
326 | /* if not, recurse and expand */ | |
327 | rlen = expand_symbol(best_table[c], best_table_len[c], result); | |
328 | total += rlen; | |
329 | result += rlen; | |
330 | } | |
331 | data++; | |
332 | len--; | |
333 | } | |
334 | *result=0; | |
335 | ||
336 | return total; | |
337 | } | |
338 | ||
1a7c8d24 | 339 | static bool symbol_absolute(const struct sym_entry *s) |
78eb7159 | 340 | { |
8c996940 | 341 | return s->percpu_absolute; |
78eb7159 KC |
342 | } |
343 | ||
60443c88 ZL |
344 | static int compare_names(const void *a, const void *b) |
345 | { | |
346 | int ret; | |
60443c88 ZL |
347 | const struct sym_entry *sa = *(const struct sym_entry **)a; |
348 | const struct sym_entry *sb = *(const struct sym_entry **)b; | |
349 | ||
dd1553b8 | 350 | ret = strcmp(sym_name(sa), sym_name(sb)); |
60443c88 ZL |
351 | if (!ret) { |
352 | if (sa->addr > sb->addr) | |
353 | return 1; | |
354 | else if (sa->addr < sb->addr) | |
355 | return -1; | |
356 | ||
357 | /* keep old order */ | |
358 | return (int)(sa->seq - sb->seq); | |
359 | } | |
360 | ||
361 | return ret; | |
362 | } | |
363 | ||
364 | static void sort_symbols_by_name(void) | |
365 | { | |
366 | qsort(table, table_cnt, sizeof(table[0]), compare_names); | |
367 | } | |
368 | ||
b3dbb4ec | 369 | static void write_src(void) |
1da177e4 | 370 | { |
b3dbb4ec | 371 | unsigned int i, k, off; |
1da177e4 | 372 | unsigned int best_idx[256]; |
bde6fb37 | 373 | unsigned int *markers, markers_cnt; |
9281acea | 374 | char buf[KSYM_NAME_LEN]; |
1da177e4 | 375 | |
500193ec | 376 | printf("#include <asm/bitsperlong.h>\n"); |
1da177e4 LT |
377 | printf("#if BITS_PER_LONG == 64\n"); |
378 | printf("#define PTR .quad\n"); | |
72d3ebb9 | 379 | printf("#define ALGN .balign 8\n"); |
1da177e4 LT |
380 | printf("#else\n"); |
381 | printf("#define PTR .long\n"); | |
72d3ebb9 | 382 | printf("#define ALGN .balign 4\n"); |
1da177e4 LT |
383 | printf("#endif\n"); |
384 | ||
aad09470 | 385 | printf("\t.section .rodata, \"a\"\n"); |
1da177e4 | 386 | |
1da177e4 | 387 | output_label("kallsyms_num_syms"); |
80ffbaa5 | 388 | printf("\t.long\t%u\n", table_cnt); |
1da177e4 LT |
389 | printf("\n"); |
390 | ||
391 | /* table of offset markers, that give the offset in the compressed stream | |
392 | * every 256 symbols */ | |
bde6fb37 MY |
393 | markers_cnt = (table_cnt + 255) / 256; |
394 | markers = malloc(sizeof(*markers) * markers_cnt); | |
f1a136e0 JJ |
395 | if (!markers) { |
396 | fprintf(stderr, "kallsyms failure: " | |
397 | "unable to allocate required memory\n"); | |
398 | exit(EXIT_FAILURE); | |
399 | } | |
1da177e4 LT |
400 | |
401 | output_label("kallsyms_names"); | |
1da177e4 | 402 | off = 0; |
b3dbb4ec PM |
403 | for (i = 0; i < table_cnt; i++) { |
404 | if ((i & 0xFF) == 0) | |
405 | markers[i >> 8] = off; | |
60443c88 | 406 | table[i]->seq = i; |
1da177e4 | 407 | |
73bbb944 MO |
408 | /* There cannot be any symbol of length zero. */ |
409 | if (table[i]->len == 0) { | |
410 | fprintf(stderr, "kallsyms failure: " | |
411 | "unexpected zero symbol length\n"); | |
412 | exit(EXIT_FAILURE); | |
413 | } | |
414 | ||
415 | /* Only lengths that fit in up-to-two-byte ULEB128 are supported. */ | |
416 | if (table[i]->len > 0x3FFF) { | |
417 | fprintf(stderr, "kallsyms failure: " | |
418 | "unexpected huge symbol length\n"); | |
419 | exit(EXIT_FAILURE); | |
420 | } | |
421 | ||
422 | /* Encode length with ULEB128. */ | |
423 | if (table[i]->len <= 0x7F) { | |
424 | /* Most symbols use a single byte for the length. */ | |
425 | printf("\t.byte 0x%02x", table[i]->len); | |
426 | off += table[i]->len + 1; | |
427 | } else { | |
428 | /* "Big" symbols use two bytes. */ | |
429 | printf("\t.byte 0x%02x, 0x%02x", | |
430 | (table[i]->len & 0x7F) | 0x80, | |
431 | (table[i]->len >> 7) & 0x7F); | |
432 | off += table[i]->len + 2; | |
433 | } | |
8d605269 MY |
434 | for (k = 0; k < table[i]->len; k++) |
435 | printf(", 0x%02x", table[i]->sym[k]); | |
1da177e4 | 436 | |
f9c3d671 MY |
437 | /* |
438 | * Now that we wrote out the compressed symbol name, restore the | |
439 | * original name and print it in the comment. | |
440 | */ | |
dd1553b8 MY |
441 | expand_symbol(table[i]->sym, table[i]->len, buf); |
442 | strcpy((char *)table[i]->sym, buf); | |
f9c3d671 | 443 | printf("\t/* %s */\n", table[i]->sym); |
dd1553b8 | 444 | } |
f9c3d671 | 445 | printf("\n"); |
dd1553b8 | 446 | |
1da177e4 | 447 | output_label("kallsyms_markers"); |
bde6fb37 | 448 | for (i = 0; i < markers_cnt; i++) |
80ffbaa5 | 449 | printf("\t.long\t%u\n", markers[i]); |
1da177e4 LT |
450 | printf("\n"); |
451 | ||
452 | free(markers); | |
453 | ||
454 | output_label("kallsyms_token_table"); | |
455 | off = 0; | |
456 | for (i = 0; i < 256; i++) { | |
457 | best_idx[i] = off; | |
b3dbb4ec | 458 | expand_symbol(best_table[i], best_table_len[i], buf); |
1da177e4 LT |
459 | printf("\t.asciz\t\"%s\"\n", buf); |
460 | off += strlen(buf) + 1; | |
461 | } | |
462 | printf("\n"); | |
463 | ||
464 | output_label("kallsyms_token_index"); | |
465 | for (i = 0; i < 256; i++) | |
466 | printf("\t.short\t%d\n", best_idx[i]); | |
467 | printf("\n"); | |
404bad70 | 468 | |
64e16609 | 469 | output_label("kallsyms_offsets"); |
404bad70 MY |
470 | |
471 | for (i = 0; i < table_cnt; i++) { | |
64e16609 JH |
472 | /* |
473 | * Use the offset relative to the lowest value | |
474 | * encountered of all relative symbols, and emit | |
475 | * non-relocatable fixed offsets that will be fixed | |
476 | * up at runtime. | |
477 | */ | |
404bad70 | 478 | |
64e16609 JH |
479 | long long offset; |
480 | int overflow; | |
481 | ||
482 | if (!absolute_percpu) { | |
483 | offset = table[i]->addr - relative_base; | |
484 | overflow = (offset < 0 || offset > UINT_MAX); | |
485 | } else if (symbol_absolute(table[i])) { | |
486 | offset = table[i]->addr; | |
487 | overflow = (offset < 0 || offset > INT_MAX); | |
404bad70 | 488 | } else { |
64e16609 JH |
489 | offset = relative_base - table[i]->addr - 1; |
490 | overflow = (offset < INT_MIN || offset >= 0); | |
491 | } | |
492 | if (overflow) { | |
493 | fprintf(stderr, "kallsyms failure: " | |
494 | "%s symbol value %#llx out of range in relative mode\n", | |
495 | symbol_absolute(table[i]) ? "absolute" : "relative", | |
496 | table[i]->addr); | |
497 | exit(EXIT_FAILURE); | |
404bad70 | 498 | } |
b07e1810 | 499 | printf("\t.long\t%#x\t/* %s */\n", (int)offset, table[i]->sym); |
404bad70 MY |
500 | } |
501 | printf("\n"); | |
502 | ||
64e16609 JH |
503 | output_label("kallsyms_relative_base"); |
504 | output_address(relative_base); | |
505 | printf("\n"); | |
404bad70 MY |
506 | |
507 | sort_symbols_by_name(); | |
508 | output_label("kallsyms_seqs_of_names"); | |
509 | for (i = 0; i < table_cnt; i++) | |
f9c3d671 | 510 | printf("\t.byte 0x%02x, 0x%02x, 0x%02x\t/* %s */\n", |
404bad70 MY |
511 | (unsigned char)(table[i]->seq >> 16), |
512 | (unsigned char)(table[i]->seq >> 8), | |
f9c3d671 MY |
513 | (unsigned char)(table[i]->seq >> 0), |
514 | table[i]->sym); | |
404bad70 | 515 | printf("\n"); |
1da177e4 LT |
516 | } |
517 | ||
518 | ||
519 | /* table lookup compression functions */ | |
520 | ||
1da177e4 | 521 | /* count all the possible tokens in a symbol */ |
4bfe2b78 | 522 | static void learn_symbol(const unsigned char *symbol, int len) |
1da177e4 LT |
523 | { |
524 | int i; | |
525 | ||
526 | for (i = 0; i < len - 1; i++) | |
b3dbb4ec | 527 | token_profit[ symbol[i] + (symbol[i + 1] << 8) ]++; |
1da177e4 LT |
528 | } |
529 | ||
530 | /* decrease the count for all the possible tokens in a symbol */ | |
4bfe2b78 | 531 | static void forget_symbol(const unsigned char *symbol, int len) |
1da177e4 LT |
532 | { |
533 | int i; | |
534 | ||
535 | for (i = 0; i < len - 1; i++) | |
b3dbb4ec | 536 | token_profit[ symbol[i] + (symbol[i + 1] << 8) ]--; |
1da177e4 LT |
537 | } |
538 | ||
5e5c4fa7 | 539 | /* do the initial token count */ |
fcdf7197 | 540 | static void build_initial_token_table(void) |
1da177e4 | 541 | { |
5e5c4fa7 | 542 | unsigned int i; |
1da177e4 | 543 | |
5e5c4fa7 | 544 | for (i = 0; i < table_cnt; i++) |
8d605269 | 545 | learn_symbol(table[i]->sym, table[i]->len); |
1da177e4 LT |
546 | } |
547 | ||
2558c138 | 548 | static unsigned char *find_token(unsigned char *str, int len, |
4bfe2b78 | 549 | const unsigned char *token) |
7c5d249a PM |
550 | { |
551 | int i; | |
552 | ||
553 | for (i = 0; i < len - 1; i++) { | |
554 | if (str[i] == token[0] && str[i+1] == token[1]) | |
555 | return &str[i]; | |
556 | } | |
557 | return NULL; | |
558 | } | |
559 | ||
1da177e4 LT |
560 | /* replace a given token in all the valid symbols. Use the sampled symbols |
561 | * to update the counts */ | |
4bfe2b78 | 562 | static void compress_symbols(const unsigned char *str, int idx) |
1da177e4 | 563 | { |
b3dbb4ec PM |
564 | unsigned int i, len, size; |
565 | unsigned char *p1, *p2; | |
1da177e4 | 566 | |
b3dbb4ec | 567 | for (i = 0; i < table_cnt; i++) { |
1da177e4 | 568 | |
8d605269 MY |
569 | len = table[i]->len; |
570 | p1 = table[i]->sym; | |
b3dbb4ec PM |
571 | |
572 | /* find the token on the symbol */ | |
7c5d249a | 573 | p2 = find_token(p1, len, str); |
b3dbb4ec PM |
574 | if (!p2) continue; |
575 | ||
576 | /* decrease the counts for this symbol's tokens */ | |
8d605269 | 577 | forget_symbol(table[i]->sym, len); |
b3dbb4ec PM |
578 | |
579 | size = len; | |
1da177e4 LT |
580 | |
581 | do { | |
b3dbb4ec PM |
582 | *p2 = idx; |
583 | p2++; | |
584 | size -= (p2 - p1); | |
585 | memmove(p2, p2 + 1, size); | |
586 | p1 = p2; | |
587 | len--; | |
588 | ||
589 | if (size < 2) break; | |
590 | ||
1da177e4 | 591 | /* find the token on the symbol */ |
7c5d249a | 592 | p2 = find_token(p1, size, str); |
1da177e4 | 593 | |
b3dbb4ec | 594 | } while (p2); |
1da177e4 | 595 | |
8d605269 | 596 | table[i]->len = len; |
1da177e4 | 597 | |
b3dbb4ec | 598 | /* increase the counts for this symbol's new tokens */ |
8d605269 | 599 | learn_symbol(table[i]->sym, len); |
1da177e4 LT |
600 | } |
601 | } | |
602 | ||
603 | /* search the token with the maximum profit */ | |
b3dbb4ec | 604 | static int find_best_token(void) |
1da177e4 | 605 | { |
b3dbb4ec | 606 | int i, best, bestprofit; |
1da177e4 LT |
607 | |
608 | bestprofit=-10000; | |
b3dbb4ec | 609 | best = 0; |
1da177e4 | 610 | |
b3dbb4ec PM |
611 | for (i = 0; i < 0x10000; i++) { |
612 | if (token_profit[i] > bestprofit) { | |
613 | best = i; | |
614 | bestprofit = token_profit[i]; | |
1da177e4 | 615 | } |
1da177e4 | 616 | } |
1da177e4 LT |
617 | return best; |
618 | } | |
619 | ||
620 | /* this is the core of the algorithm: calculate the "best" table */ | |
621 | static void optimize_result(void) | |
622 | { | |
b3dbb4ec | 623 | int i, best; |
1da177e4 LT |
624 | |
625 | /* using the '\0' symbol last allows compress_symbols to use standard | |
626 | * fast string functions */ | |
627 | for (i = 255; i >= 0; i--) { | |
628 | ||
629 | /* if this table slot is empty (it is not used by an actual | |
630 | * original char code */ | |
631 | if (!best_table_len[i]) { | |
632 | ||
cbf7a90e | 633 | /* find the token with the best profit value */ |
1da177e4 | 634 | best = find_best_token(); |
e0a04b11 XW |
635 | if (token_profit[best] == 0) |
636 | break; | |
1da177e4 LT |
637 | |
638 | /* place it in the "best" table */ | |
b3dbb4ec PM |
639 | best_table_len[i] = 2; |
640 | best_table[i][0] = best & 0xFF; | |
641 | best_table[i][1] = (best >> 8) & 0xFF; | |
1da177e4 LT |
642 | |
643 | /* replace this token in all the valid symbols */ | |
b3dbb4ec | 644 | compress_symbols(best_table[i], i); |
1da177e4 LT |
645 | } |
646 | } | |
647 | } | |
648 | ||
649 | /* start by placing the symbols that are actually used on the table */ | |
650 | static void insert_real_symbols_in_table(void) | |
651 | { | |
b3dbb4ec | 652 | unsigned int i, j, c; |
1da177e4 | 653 | |
b3dbb4ec | 654 | for (i = 0; i < table_cnt; i++) { |
8d605269 MY |
655 | for (j = 0; j < table[i]->len; j++) { |
656 | c = table[i]->sym[j]; | |
b3dbb4ec PM |
657 | best_table[c][0]=c; |
658 | best_table_len[c]=1; | |
1da177e4 LT |
659 | } |
660 | } | |
661 | } | |
662 | ||
663 | static void optimize_token_table(void) | |
664 | { | |
fcdf7197 | 665 | build_initial_token_table(); |
1da177e4 LT |
666 | |
667 | insert_real_symbols_in_table(); | |
668 | ||
669 | optimize_result(); | |
670 | } | |
671 | ||
b478b782 LJ |
672 | /* guess for "linker script provide" symbol */ |
673 | static int may_be_linker_script_provide_symbol(const struct sym_entry *se) | |
674 | { | |
29e55ad3 | 675 | const char *symbol = sym_name(se); |
b478b782 LJ |
676 | int len = se->len - 1; |
677 | ||
678 | if (len < 8) | |
679 | return 0; | |
680 | ||
681 | if (symbol[0] != '_' || symbol[1] != '_') | |
682 | return 0; | |
683 | ||
684 | /* __start_XXXXX */ | |
685 | if (!memcmp(symbol + 2, "start_", 6)) | |
686 | return 1; | |
687 | ||
688 | /* __stop_XXXXX */ | |
689 | if (!memcmp(symbol + 2, "stop_", 5)) | |
690 | return 1; | |
691 | ||
692 | /* __end_XXXXX */ | |
693 | if (!memcmp(symbol + 2, "end_", 4)) | |
694 | return 1; | |
695 | ||
696 | /* __XXXXX_start */ | |
697 | if (!memcmp(symbol + len - 6, "_start", 6)) | |
698 | return 1; | |
699 | ||
700 | /* __XXXXX_end */ | |
701 | if (!memcmp(symbol + len - 4, "_end", 4)) | |
702 | return 1; | |
703 | ||
704 | return 0; | |
705 | } | |
706 | ||
f2df3f65 PM |
707 | static int compare_symbols(const void *a, const void *b) |
708 | { | |
8d605269 MY |
709 | const struct sym_entry *sa = *(const struct sym_entry **)a; |
710 | const struct sym_entry *sb = *(const struct sym_entry **)b; | |
f2df3f65 PM |
711 | int wa, wb; |
712 | ||
f2df3f65 PM |
713 | /* sort by address first */ |
714 | if (sa->addr > sb->addr) | |
715 | return 1; | |
716 | if (sa->addr < sb->addr) | |
717 | return -1; | |
718 | ||
719 | /* sort by "weakness" type */ | |
720 | wa = (sa->sym[0] == 'w') || (sa->sym[0] == 'W'); | |
721 | wb = (sb->sym[0] == 'w') || (sb->sym[0] == 'W'); | |
722 | if (wa != wb) | |
723 | return wa - wb; | |
724 | ||
b478b782 LJ |
725 | /* sort by "linker script provide" type */ |
726 | wa = may_be_linker_script_provide_symbol(sa); | |
727 | wb = may_be_linker_script_provide_symbol(sb); | |
728 | if (wa != wb) | |
729 | return wa - wb; | |
730 | ||
731 | /* sort by the number of prefix underscores */ | |
aa915245 MY |
732 | wa = strspn(sym_name(sa), "_"); |
733 | wb = strspn(sym_name(sb), "_"); | |
b478b782 LJ |
734 | if (wa != wb) |
735 | return wa - wb; | |
736 | ||
f2df3f65 | 737 | /* sort by initial order, so that other symbols are left undisturbed */ |
1d48f8fe | 738 | return sa->seq - sb->seq; |
f2df3f65 PM |
739 | } |
740 | ||
741 | static void sort_symbols(void) | |
742 | { | |
8d605269 | 743 | qsort(table, table_cnt, sizeof(table[0]), compare_symbols); |
f2df3f65 | 744 | } |
1da177e4 | 745 | |
c6bda7c9 RR |
746 | static void make_percpus_absolute(void) |
747 | { | |
748 | unsigned int i; | |
749 | ||
750 | for (i = 0; i < table_cnt; i++) | |
8d605269 | 751 | if (symbol_in_range(table[i], &percpu_range, 1)) { |
8c996940 AB |
752 | /* |
753 | * Keep the 'A' override for percpu symbols to | |
754 | * ensure consistent behavior compared to older | |
755 | * versions of this tool. | |
756 | */ | |
8d605269 | 757 | table[i]->sym[0] = 'A'; |
1a7c8d24 | 758 | table[i]->percpu_absolute = true; |
8c996940 | 759 | } |
c6bda7c9 RR |
760 | } |
761 | ||
2213e9a6 AB |
762 | /* find the minimum non-absolute symbol address */ |
763 | static void record_relative_base(void) | |
764 | { | |
765 | unsigned int i; | |
766 | ||
2213e9a6 | 767 | for (i = 0; i < table_cnt; i++) |
8d605269 | 768 | if (!symbol_absolute(table[i])) { |
f34ea029 MY |
769 | /* |
770 | * The table is sorted by address. | |
771 | * Take the first non-absolute symbol value. | |
772 | */ | |
8d605269 | 773 | relative_base = table[i]->addr; |
f34ea029 MY |
774 | return; |
775 | } | |
2213e9a6 AB |
776 | } |
777 | ||
b3dbb4ec | 778 | int main(int argc, char **argv) |
1da177e4 | 779 | { |
aa221f2e | 780 | while (1) { |
92e74fb6 | 781 | static const struct option long_options[] = { |
aa221f2e MY |
782 | {"all-symbols", no_argument, &all_symbols, 1}, |
783 | {"absolute-percpu", no_argument, &absolute_percpu, 1}, | |
aa221f2e MY |
784 | {}, |
785 | }; | |
786 | ||
787 | int c = getopt_long(argc, argv, "", long_options, NULL); | |
788 | ||
789 | if (c == -1) | |
790 | break; | |
791 | if (c != 0) | |
792 | usage(); | |
793 | } | |
794 | ||
795 | if (optind >= argc) | |
1da177e4 LT |
796 | usage(); |
797 | ||
aa221f2e | 798 | read_map(argv[optind]); |
5e5c4fa7 | 799 | shrink_table(); |
c6bda7c9 RR |
800 | if (absolute_percpu) |
801 | make_percpus_absolute(); | |
f34ea029 | 802 | sort_symbols(); |
64e16609 | 803 | record_relative_base(); |
2ea03891 | 804 | optimize_token_table(); |
1da177e4 LT |
805 | write_src(); |
806 | ||
807 | return 0; | |
808 | } |