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Commit | Line | Data |
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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 | * | |
8 | * Usage: nm -n vmlinux | scripts/kallsyms [--all-symbols] > symbols.S | |
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 | ||
21 | #include <stdio.h> | |
22 | #include <stdlib.h> | |
23 | #include <string.h> | |
24 | #include <ctype.h> | |
2213e9a6 | 25 | #include <limits.h> |
1da177e4 | 26 | |
17b1f0de | 27 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0])) |
17b1f0de | 28 | |
9281acea | 29 | #define KSYM_NAME_LEN 128 |
1da177e4 | 30 | |
1da177e4 LT |
31 | struct sym_entry { |
32 | unsigned long long addr; | |
b3dbb4ec | 33 | unsigned int len; |
f2df3f65 | 34 | unsigned int start_pos; |
1da177e4 | 35 | unsigned char *sym; |
8c996940 | 36 | unsigned int percpu_absolute; |
1da177e4 LT |
37 | }; |
38 | ||
78eb7159 KC |
39 | struct addr_range { |
40 | const char *start_sym, *end_sym; | |
17b1f0de MF |
41 | unsigned long long start, end; |
42 | }; | |
43 | ||
44 | static unsigned long long _text; | |
2213e9a6 | 45 | static unsigned long long relative_base; |
78eb7159 | 46 | static struct addr_range text_ranges[] = { |
17b1f0de MF |
47 | { "_stext", "_etext" }, |
48 | { "_sinittext", "_einittext" }, | |
17b1f0de MF |
49 | }; |
50 | #define text_range_text (&text_ranges[0]) | |
51 | #define text_range_inittext (&text_ranges[1]) | |
52 | ||
c6bda7c9 RR |
53 | static struct addr_range percpu_range = { |
54 | "__per_cpu_start", "__per_cpu_end", -1ULL, 0 | |
55 | }; | |
56 | ||
1da177e4 | 57 | static struct sym_entry *table; |
b3dbb4ec | 58 | static unsigned int table_size, table_cnt; |
1da177e4 | 59 | static int all_symbols = 0; |
c6bda7c9 | 60 | static int absolute_percpu = 0; |
2213e9a6 | 61 | static int base_relative = 0; |
1da177e4 | 62 | |
f43e9daa | 63 | static int token_profit[0x10000]; |
1da177e4 LT |
64 | |
65 | /* the table that holds the result of the compression */ | |
f43e9daa MY |
66 | static unsigned char best_table[256][2]; |
67 | static unsigned char best_table_len[256]; | |
1da177e4 LT |
68 | |
69 | ||
b3dbb4ec | 70 | static void usage(void) |
1da177e4 | 71 | { |
f6537f2f | 72 | fprintf(stderr, "Usage: kallsyms [--all-symbols] " |
2213e9a6 | 73 | "[--base-relative] < in.map > out.S\n"); |
1da177e4 LT |
74 | exit(1); |
75 | } | |
76 | ||
77 | /* | |
78 | * This ignores the intensely annoying "mapping symbols" found | |
79 | * in ARM ELF files: $a, $t and $d. | |
80 | */ | |
f43e9daa | 81 | static int is_arm_mapping_symbol(const char *str) |
1da177e4 | 82 | { |
6c34f1f5 | 83 | return str[0] == '$' && strchr("axtd", str[1]) |
1da177e4 LT |
84 | && (str[2] == '\0' || str[2] == '.'); |
85 | } | |
86 | ||
78eb7159 KC |
87 | static int check_symbol_range(const char *sym, unsigned long long addr, |
88 | struct addr_range *ranges, int entries) | |
17b1f0de MF |
89 | { |
90 | size_t i; | |
78eb7159 | 91 | struct addr_range *ar; |
17b1f0de | 92 | |
78eb7159 KC |
93 | for (i = 0; i < entries; ++i) { |
94 | ar = &ranges[i]; | |
17b1f0de | 95 | |
78eb7159 KC |
96 | if (strcmp(sym, ar->start_sym) == 0) { |
97 | ar->start = addr; | |
17b1f0de | 98 | return 0; |
78eb7159 KC |
99 | } else if (strcmp(sym, ar->end_sym) == 0) { |
100 | ar->end = addr; | |
17b1f0de MF |
101 | return 0; |
102 | } | |
103 | } | |
104 | ||
105 | return 1; | |
106 | } | |
107 | ||
b3dbb4ec | 108 | static int read_symbol(FILE *in, struct sym_entry *s) |
1da177e4 | 109 | { |
534c9f2e | 110 | char sym[500], stype; |
1da177e4 LT |
111 | int rc; |
112 | ||
534c9f2e | 113 | rc = fscanf(in, "%llx %c %499s\n", &s->addr, &stype, sym); |
1da177e4 | 114 | if (rc != 3) { |
534c9f2e | 115 | if (rc != EOF && fgets(sym, 500, in) == NULL) |
ef894870 | 116 | fprintf(stderr, "Read error or end of file.\n"); |
1da177e4 LT |
117 | return -1; |
118 | } | |
6db2983c EL |
119 | if (strlen(sym) >= KSYM_NAME_LEN) { |
120 | fprintf(stderr, "Symbol %s too long for kallsyms (%zu >= %d).\n" | |
bb66fc67 | 121 | "Please increase KSYM_NAME_LEN both in kernel and kallsyms.c\n", |
534c9f2e | 122 | sym, strlen(sym), KSYM_NAME_LEN); |
f3462aa9 AK |
123 | return -1; |
124 | } | |
1da177e4 LT |
125 | |
126 | /* Ignore most absolute/undefined (?) symbols. */ | |
fd593d12 EB |
127 | if (strcmp(sym, "_text") == 0) |
128 | _text = s->addr; | |
78eb7159 KC |
129 | else if (check_symbol_range(sym, s->addr, text_ranges, |
130 | ARRAY_SIZE(text_ranges)) == 0) | |
17b1f0de | 131 | /* nothing to do */; |
b3dbb4ec | 132 | else if (toupper(stype) == 'A') |
1da177e4 LT |
133 | { |
134 | /* Keep these useful absolute symbols */ | |
41f11a4f YS |
135 | if (strcmp(sym, "__kernel_syscall_via_break") && |
136 | strcmp(sym, "__kernel_syscall_via_epc") && | |
137 | strcmp(sym, "__kernel_sigtramp") && | |
138 | strcmp(sym, "__gp")) | |
1da177e4 LT |
139 | return -1; |
140 | ||
141 | } | |
b3dbb4ec | 142 | else if (toupper(stype) == 'U' || |
41f11a4f | 143 | is_arm_mapping_symbol(sym)) |
1da177e4 | 144 | return -1; |
6f00df24 | 145 | /* exclude also MIPS ELF local symbols ($L123 instead of .L123) */ |
534c9f2e | 146 | else if (sym[0] == '$') |
6f00df24 | 147 | return -1; |
aab34ac8 | 148 | /* exclude debugging symbols */ |
51962a9d | 149 | else if (stype == 'N' || stype == 'n') |
aab34ac8 | 150 | return -1; |
33177f01 VG |
151 | /* exclude s390 kasan local symbols */ |
152 | else if (!strncmp(sym, ".LASANPC", 8)) | |
153 | return -1; | |
1da177e4 LT |
154 | |
155 | /* include the type field in the symbol name, so that it gets | |
156 | * compressed together */ | |
534c9f2e | 157 | s->len = strlen(sym) + 1; |
b3dbb4ec | 158 | s->sym = malloc(s->len + 1); |
f1a136e0 JJ |
159 | if (!s->sym) { |
160 | fprintf(stderr, "kallsyms failure: " | |
161 | "unable to allocate required amount of memory\n"); | |
162 | exit(EXIT_FAILURE); | |
163 | } | |
534c9f2e | 164 | strcpy((char *)s->sym + 1, sym); |
b3dbb4ec | 165 | s->sym[0] = stype; |
1da177e4 | 166 | |
8c996940 AB |
167 | s->percpu_absolute = 0; |
168 | ||
c6bda7c9 RR |
169 | /* Record if we've found __per_cpu_start/end. */ |
170 | check_symbol_range(sym, s->addr, &percpu_range, 1); | |
171 | ||
1da177e4 LT |
172 | return 0; |
173 | } | |
174 | ||
78eb7159 KC |
175 | static int symbol_in_range(struct sym_entry *s, struct addr_range *ranges, |
176 | int entries) | |
17b1f0de MF |
177 | { |
178 | size_t i; | |
78eb7159 | 179 | struct addr_range *ar; |
17b1f0de | 180 | |
78eb7159 KC |
181 | for (i = 0; i < entries; ++i) { |
182 | ar = &ranges[i]; | |
17b1f0de | 183 | |
78eb7159 | 184 | if (s->addr >= ar->start && s->addr <= ar->end) |
ac6ca5c8 | 185 | return 1; |
17b1f0de MF |
186 | } |
187 | ||
ac6ca5c8 | 188 | return 0; |
17b1f0de MF |
189 | } |
190 | ||
b3dbb4ec | 191 | static int symbol_valid(struct sym_entry *s) |
1da177e4 LT |
192 | { |
193 | /* Symbols which vary between passes. Passes 1 and 2 must have | |
2ea03891 SR |
194 | * identical symbol lists. The kallsyms_* symbols below are only added |
195 | * after pass 1, they would be included in pass 2 when --all-symbols is | |
196 | * specified so exclude them to get a stable symbol list. | |
1da177e4 LT |
197 | */ |
198 | static char *special_symbols[] = { | |
2ea03891 | 199 | "kallsyms_addresses", |
2213e9a6 AB |
200 | "kallsyms_offsets", |
201 | "kallsyms_relative_base", | |
2ea03891 SR |
202 | "kallsyms_num_syms", |
203 | "kallsyms_names", | |
204 | "kallsyms_markers", | |
205 | "kallsyms_token_table", | |
206 | "kallsyms_token_index", | |
207 | ||
1da177e4 LT |
208 | /* Exclude linker generated symbols which vary between passes */ |
209 | "_SDA_BASE_", /* ppc */ | |
210 | "_SDA2_BASE_", /* ppc */ | |
211 | NULL }; | |
bd8b22d2 | 212 | |
56067812 AB |
213 | static char *special_prefixes[] = { |
214 | "__crc_", /* modversions */ | |
1212f7a1 | 215 | "__efistub_", /* arm64 EFI stub namespace */ |
56067812 AB |
216 | NULL }; |
217 | ||
bd8b22d2 | 218 | static char *special_suffixes[] = { |
bd8b22d2 | 219 | "_veneer", /* arm */ |
b9b74be1 AB |
220 | "_from_arm", /* arm */ |
221 | "_from_thumb", /* arm */ | |
bd8b22d2 AB |
222 | NULL }; |
223 | ||
1da177e4 | 224 | int i; |
bd8b22d2 AB |
225 | char *sym_name = (char *)s->sym + 1; |
226 | ||
1da177e4 LT |
227 | /* if --all-symbols is not specified, then symbols outside the text |
228 | * and inittext sections are discarded */ | |
229 | if (!all_symbols) { | |
78eb7159 KC |
230 | if (symbol_in_range(s, text_ranges, |
231 | ARRAY_SIZE(text_ranges)) == 0) | |
1da177e4 LT |
232 | return 0; |
233 | /* Corner case. Discard any symbols with the same value as | |
a3b81113 RG |
234 | * _etext _einittext; they can move between pass 1 and 2 when |
235 | * the kallsyms data are added. If these symbols move then | |
236 | * they may get dropped in pass 2, which breaks the kallsyms | |
237 | * rules. | |
1da177e4 | 238 | */ |
17b1f0de | 239 | if ((s->addr == text_range_text->end && |
bd8b22d2 | 240 | strcmp(sym_name, |
78eb7159 | 241 | text_range_text->end_sym)) || |
17b1f0de | 242 | (s->addr == text_range_inittext->end && |
bd8b22d2 | 243 | strcmp(sym_name, |
78eb7159 | 244 | text_range_inittext->end_sym))) |
1da177e4 LT |
245 | return 0; |
246 | } | |
247 | ||
248 | /* Exclude symbols which vary between passes. */ | |
1da177e4 | 249 | for (i = 0; special_symbols[i]; i++) |
bd8b22d2 | 250 | if (strcmp(sym_name, special_symbols[i]) == 0) |
1da177e4 LT |
251 | return 0; |
252 | ||
56067812 AB |
253 | for (i = 0; special_prefixes[i]; i++) { |
254 | int l = strlen(special_prefixes[i]); | |
255 | ||
256 | if (l <= strlen(sym_name) && | |
257 | strncmp(sym_name, special_prefixes[i], l) == 0) | |
258 | return 0; | |
259 | } | |
260 | ||
bd8b22d2 AB |
261 | for (i = 0; special_suffixes[i]; i++) { |
262 | int l = strlen(sym_name) - strlen(special_suffixes[i]); | |
263 | ||
264 | if (l >= 0 && strcmp(sym_name + l, special_suffixes[i]) == 0) | |
265 | return 0; | |
266 | } | |
267 | ||
1da177e4 LT |
268 | return 1; |
269 | } | |
270 | ||
b3dbb4ec | 271 | static void read_map(FILE *in) |
1da177e4 LT |
272 | { |
273 | while (!feof(in)) { | |
b3dbb4ec PM |
274 | if (table_cnt >= table_size) { |
275 | table_size += 10000; | |
276 | table = realloc(table, sizeof(*table) * table_size); | |
1da177e4 LT |
277 | if (!table) { |
278 | fprintf(stderr, "out of memory\n"); | |
279 | exit (1); | |
280 | } | |
281 | } | |
f2df3f65 PM |
282 | if (read_symbol(in, &table[table_cnt]) == 0) { |
283 | table[table_cnt].start_pos = table_cnt; | |
b3dbb4ec | 284 | table_cnt++; |
f2df3f65 | 285 | } |
1da177e4 LT |
286 | } |
287 | } | |
288 | ||
289 | static void output_label(char *label) | |
290 | { | |
534c9f2e | 291 | printf(".globl %s\n", label); |
1da177e4 | 292 | printf("\tALGN\n"); |
534c9f2e | 293 | printf("%s:\n", label); |
1da177e4 LT |
294 | } |
295 | ||
296 | /* uncompress a compressed symbol. When this function is called, the best table | |
297 | * might still be compressed itself, so the function needs to be recursive */ | |
298 | static int expand_symbol(unsigned char *data, int len, char *result) | |
299 | { | |
300 | int c, rlen, total=0; | |
301 | ||
302 | while (len) { | |
303 | c = *data; | |
304 | /* if the table holds a single char that is the same as the one | |
305 | * we are looking for, then end the search */ | |
306 | if (best_table[c][0]==c && best_table_len[c]==1) { | |
307 | *result++ = c; | |
308 | total++; | |
309 | } else { | |
310 | /* if not, recurse and expand */ | |
311 | rlen = expand_symbol(best_table[c], best_table_len[c], result); | |
312 | total += rlen; | |
313 | result += rlen; | |
314 | } | |
315 | data++; | |
316 | len--; | |
317 | } | |
318 | *result=0; | |
319 | ||
320 | return total; | |
321 | } | |
322 | ||
78eb7159 KC |
323 | static int symbol_absolute(struct sym_entry *s) |
324 | { | |
8c996940 | 325 | return s->percpu_absolute; |
78eb7159 KC |
326 | } |
327 | ||
b3dbb4ec | 328 | static void write_src(void) |
1da177e4 | 329 | { |
b3dbb4ec | 330 | unsigned int i, k, off; |
1da177e4 LT |
331 | unsigned int best_idx[256]; |
332 | unsigned int *markers; | |
9281acea | 333 | char buf[KSYM_NAME_LEN]; |
1da177e4 | 334 | |
500193ec | 335 | printf("#include <asm/bitsperlong.h>\n"); |
1da177e4 LT |
336 | printf("#if BITS_PER_LONG == 64\n"); |
337 | printf("#define PTR .quad\n"); | |
72d3ebb9 | 338 | printf("#define ALGN .balign 8\n"); |
1da177e4 LT |
339 | printf("#else\n"); |
340 | printf("#define PTR .long\n"); | |
72d3ebb9 | 341 | printf("#define ALGN .balign 4\n"); |
1da177e4 LT |
342 | printf("#endif\n"); |
343 | ||
aad09470 | 344 | printf("\t.section .rodata, \"a\"\n"); |
1da177e4 | 345 | |
2213e9a6 AB |
346 | /* Provide proper symbols relocatability by their relativeness |
347 | * to a fixed anchor point in the runtime image, either '_text' | |
348 | * for absolute address tables, in which case the linker will | |
349 | * emit the final addresses at build time. Otherwise, use the | |
350 | * offset relative to the lowest value encountered of all relative | |
351 | * symbols, and emit non-relocatable fixed offsets that will be fixed | |
352 | * up at runtime. | |
353 | * | |
354 | * The symbol names cannot be used to construct normal symbol | |
355 | * references as the list of symbols contains symbols that are | |
356 | * declared static and are private to their .o files. This prevents | |
357 | * .tmp_kallsyms.o or any other object from referencing them. | |
fd593d12 | 358 | */ |
2213e9a6 AB |
359 | if (!base_relative) |
360 | output_label("kallsyms_addresses"); | |
361 | else | |
362 | output_label("kallsyms_offsets"); | |
363 | ||
b3dbb4ec | 364 | for (i = 0; i < table_cnt; i++) { |
2213e9a6 AB |
365 | if (base_relative) { |
366 | long long offset; | |
367 | int overflow; | |
368 | ||
369 | if (!absolute_percpu) { | |
370 | offset = table[i].addr - relative_base; | |
371 | overflow = (offset < 0 || offset > UINT_MAX); | |
372 | } else if (symbol_absolute(&table[i])) { | |
373 | offset = table[i].addr; | |
374 | overflow = (offset < 0 || offset > INT_MAX); | |
375 | } else { | |
376 | offset = relative_base - table[i].addr - 1; | |
377 | overflow = (offset < INT_MIN || offset >= 0); | |
378 | } | |
379 | if (overflow) { | |
380 | fprintf(stderr, "kallsyms failure: " | |
381 | "%s symbol value %#llx out of range in relative mode\n", | |
382 | symbol_absolute(&table[i]) ? "absolute" : "relative", | |
383 | table[i].addr); | |
384 | exit(EXIT_FAILURE); | |
385 | } | |
386 | printf("\t.long\t%#x\n", (int)offset); | |
387 | } else if (!symbol_absolute(&table[i])) { | |
2c22d8ba VG |
388 | if (_text <= table[i].addr) |
389 | printf("\tPTR\t_text + %#llx\n", | |
390 | table[i].addr - _text); | |
391 | else | |
2930ffc7 AM |
392 | printf("\tPTR\t_text - %#llx\n", |
393 | _text - table[i].addr); | |
fd593d12 EB |
394 | } else { |
395 | printf("\tPTR\t%#llx\n", table[i].addr); | |
396 | } | |
1da177e4 LT |
397 | } |
398 | printf("\n"); | |
399 | ||
2213e9a6 AB |
400 | if (base_relative) { |
401 | output_label("kallsyms_relative_base"); | |
402 | printf("\tPTR\t_text - %#llx\n", _text - relative_base); | |
403 | printf("\n"); | |
404 | } | |
405 | ||
1da177e4 | 406 | output_label("kallsyms_num_syms"); |
80ffbaa5 | 407 | printf("\t.long\t%u\n", table_cnt); |
1da177e4 LT |
408 | printf("\n"); |
409 | ||
410 | /* table of offset markers, that give the offset in the compressed stream | |
411 | * every 256 symbols */ | |
f1a136e0 JJ |
412 | markers = malloc(sizeof(unsigned int) * ((table_cnt + 255) / 256)); |
413 | if (!markers) { | |
414 | fprintf(stderr, "kallsyms failure: " | |
415 | "unable to allocate required memory\n"); | |
416 | exit(EXIT_FAILURE); | |
417 | } | |
1da177e4 LT |
418 | |
419 | output_label("kallsyms_names"); | |
1da177e4 | 420 | off = 0; |
b3dbb4ec PM |
421 | for (i = 0; i < table_cnt; i++) { |
422 | if ((i & 0xFF) == 0) | |
423 | markers[i >> 8] = off; | |
1da177e4 LT |
424 | |
425 | printf("\t.byte 0x%02x", table[i].len); | |
426 | for (k = 0; k < table[i].len; k++) | |
427 | printf(", 0x%02x", table[i].sym[k]); | |
428 | printf("\n"); | |
429 | ||
430 | off += table[i].len + 1; | |
1da177e4 LT |
431 | } |
432 | printf("\n"); | |
433 | ||
434 | output_label("kallsyms_markers"); | |
b3dbb4ec | 435 | for (i = 0; i < ((table_cnt + 255) >> 8); i++) |
80ffbaa5 | 436 | printf("\t.long\t%u\n", markers[i]); |
1da177e4 LT |
437 | printf("\n"); |
438 | ||
439 | free(markers); | |
440 | ||
441 | output_label("kallsyms_token_table"); | |
442 | off = 0; | |
443 | for (i = 0; i < 256; i++) { | |
444 | best_idx[i] = off; | |
b3dbb4ec | 445 | expand_symbol(best_table[i], best_table_len[i], buf); |
1da177e4 LT |
446 | printf("\t.asciz\t\"%s\"\n", buf); |
447 | off += strlen(buf) + 1; | |
448 | } | |
449 | printf("\n"); | |
450 | ||
451 | output_label("kallsyms_token_index"); | |
452 | for (i = 0; i < 256; i++) | |
453 | printf("\t.short\t%d\n", best_idx[i]); | |
454 | printf("\n"); | |
455 | } | |
456 | ||
457 | ||
458 | /* table lookup compression functions */ | |
459 | ||
1da177e4 LT |
460 | /* count all the possible tokens in a symbol */ |
461 | static void learn_symbol(unsigned char *symbol, int len) | |
462 | { | |
463 | int i; | |
464 | ||
465 | for (i = 0; i < len - 1; i++) | |
b3dbb4ec | 466 | token_profit[ symbol[i] + (symbol[i + 1] << 8) ]++; |
1da177e4 LT |
467 | } |
468 | ||
469 | /* decrease the count for all the possible tokens in a symbol */ | |
470 | static void forget_symbol(unsigned char *symbol, int len) | |
471 | { | |
472 | int i; | |
473 | ||
474 | for (i = 0; i < len - 1; i++) | |
b3dbb4ec | 475 | token_profit[ symbol[i] + (symbol[i + 1] << 8) ]--; |
1da177e4 LT |
476 | } |
477 | ||
b3dbb4ec | 478 | /* remove all the invalid symbols from the table and do the initial token count */ |
1da177e4 LT |
479 | static void build_initial_tok_table(void) |
480 | { | |
b3dbb4ec | 481 | unsigned int i, pos; |
1da177e4 | 482 | |
b3dbb4ec PM |
483 | pos = 0; |
484 | for (i = 0; i < table_cnt; i++) { | |
1da177e4 | 485 | if ( symbol_valid(&table[i]) ) { |
b3dbb4ec PM |
486 | if (pos != i) |
487 | table[pos] = table[i]; | |
488 | learn_symbol(table[pos].sym, table[pos].len); | |
489 | pos++; | |
21915eca MY |
490 | } else { |
491 | free(table[i].sym); | |
1da177e4 | 492 | } |
1da177e4 | 493 | } |
b3dbb4ec | 494 | table_cnt = pos; |
1da177e4 LT |
495 | } |
496 | ||
7c5d249a PM |
497 | static void *find_token(unsigned char *str, int len, unsigned char *token) |
498 | { | |
499 | int i; | |
500 | ||
501 | for (i = 0; i < len - 1; i++) { | |
502 | if (str[i] == token[0] && str[i+1] == token[1]) | |
503 | return &str[i]; | |
504 | } | |
505 | return NULL; | |
506 | } | |
507 | ||
1da177e4 LT |
508 | /* replace a given token in all the valid symbols. Use the sampled symbols |
509 | * to update the counts */ | |
b3dbb4ec | 510 | static void compress_symbols(unsigned char *str, int idx) |
1da177e4 | 511 | { |
b3dbb4ec PM |
512 | unsigned int i, len, size; |
513 | unsigned char *p1, *p2; | |
1da177e4 | 514 | |
b3dbb4ec | 515 | for (i = 0; i < table_cnt; i++) { |
1da177e4 LT |
516 | |
517 | len = table[i].len; | |
b3dbb4ec PM |
518 | p1 = table[i].sym; |
519 | ||
520 | /* find the token on the symbol */ | |
7c5d249a | 521 | p2 = find_token(p1, len, str); |
b3dbb4ec PM |
522 | if (!p2) continue; |
523 | ||
524 | /* decrease the counts for this symbol's tokens */ | |
525 | forget_symbol(table[i].sym, len); | |
526 | ||
527 | size = len; | |
1da177e4 LT |
528 | |
529 | do { | |
b3dbb4ec PM |
530 | *p2 = idx; |
531 | p2++; | |
532 | size -= (p2 - p1); | |
533 | memmove(p2, p2 + 1, size); | |
534 | p1 = p2; | |
535 | len--; | |
536 | ||
537 | if (size < 2) break; | |
538 | ||
1da177e4 | 539 | /* find the token on the symbol */ |
7c5d249a | 540 | p2 = find_token(p1, size, str); |
1da177e4 | 541 | |
b3dbb4ec | 542 | } while (p2); |
1da177e4 | 543 | |
b3dbb4ec | 544 | table[i].len = len; |
1da177e4 | 545 | |
b3dbb4ec PM |
546 | /* increase the counts for this symbol's new tokens */ |
547 | learn_symbol(table[i].sym, len); | |
1da177e4 LT |
548 | } |
549 | } | |
550 | ||
551 | /* search the token with the maximum profit */ | |
b3dbb4ec | 552 | static int find_best_token(void) |
1da177e4 | 553 | { |
b3dbb4ec | 554 | int i, best, bestprofit; |
1da177e4 LT |
555 | |
556 | bestprofit=-10000; | |
b3dbb4ec | 557 | best = 0; |
1da177e4 | 558 | |
b3dbb4ec PM |
559 | for (i = 0; i < 0x10000; i++) { |
560 | if (token_profit[i] > bestprofit) { | |
561 | best = i; | |
562 | bestprofit = token_profit[i]; | |
1da177e4 | 563 | } |
1da177e4 | 564 | } |
1da177e4 LT |
565 | return best; |
566 | } | |
567 | ||
568 | /* this is the core of the algorithm: calculate the "best" table */ | |
569 | static void optimize_result(void) | |
570 | { | |
b3dbb4ec | 571 | int i, best; |
1da177e4 LT |
572 | |
573 | /* using the '\0' symbol last allows compress_symbols to use standard | |
574 | * fast string functions */ | |
575 | for (i = 255; i >= 0; i--) { | |
576 | ||
577 | /* if this table slot is empty (it is not used by an actual | |
578 | * original char code */ | |
579 | if (!best_table_len[i]) { | |
580 | ||
cbf7a90e | 581 | /* find the token with the best profit value */ |
1da177e4 | 582 | best = find_best_token(); |
e0a04b11 XW |
583 | if (token_profit[best] == 0) |
584 | break; | |
1da177e4 LT |
585 | |
586 | /* place it in the "best" table */ | |
b3dbb4ec PM |
587 | best_table_len[i] = 2; |
588 | best_table[i][0] = best & 0xFF; | |
589 | best_table[i][1] = (best >> 8) & 0xFF; | |
1da177e4 LT |
590 | |
591 | /* replace this token in all the valid symbols */ | |
b3dbb4ec | 592 | compress_symbols(best_table[i], i); |
1da177e4 LT |
593 | } |
594 | } | |
595 | } | |
596 | ||
597 | /* start by placing the symbols that are actually used on the table */ | |
598 | static void insert_real_symbols_in_table(void) | |
599 | { | |
b3dbb4ec | 600 | unsigned int i, j, c; |
1da177e4 | 601 | |
b3dbb4ec PM |
602 | for (i = 0; i < table_cnt; i++) { |
603 | for (j = 0; j < table[i].len; j++) { | |
604 | c = table[i].sym[j]; | |
605 | best_table[c][0]=c; | |
606 | best_table_len[c]=1; | |
1da177e4 LT |
607 | } |
608 | } | |
609 | } | |
610 | ||
611 | static void optimize_token_table(void) | |
612 | { | |
1da177e4 LT |
613 | build_initial_tok_table(); |
614 | ||
615 | insert_real_symbols_in_table(); | |
616 | ||
41f11a4f | 617 | /* When valid symbol is not registered, exit to error */ |
b3dbb4ec | 618 | if (!table_cnt) { |
41f11a4f YS |
619 | fprintf(stderr, "No valid symbol.\n"); |
620 | exit(1); | |
621 | } | |
622 | ||
1da177e4 LT |
623 | optimize_result(); |
624 | } | |
625 | ||
b478b782 LJ |
626 | /* guess for "linker script provide" symbol */ |
627 | static int may_be_linker_script_provide_symbol(const struct sym_entry *se) | |
628 | { | |
629 | const char *symbol = (char *)se->sym + 1; | |
630 | int len = se->len - 1; | |
631 | ||
632 | if (len < 8) | |
633 | return 0; | |
634 | ||
635 | if (symbol[0] != '_' || symbol[1] != '_') | |
636 | return 0; | |
637 | ||
638 | /* __start_XXXXX */ | |
639 | if (!memcmp(symbol + 2, "start_", 6)) | |
640 | return 1; | |
641 | ||
642 | /* __stop_XXXXX */ | |
643 | if (!memcmp(symbol + 2, "stop_", 5)) | |
644 | return 1; | |
645 | ||
646 | /* __end_XXXXX */ | |
647 | if (!memcmp(symbol + 2, "end_", 4)) | |
648 | return 1; | |
649 | ||
650 | /* __XXXXX_start */ | |
651 | if (!memcmp(symbol + len - 6, "_start", 6)) | |
652 | return 1; | |
653 | ||
654 | /* __XXXXX_end */ | |
655 | if (!memcmp(symbol + len - 4, "_end", 4)) | |
656 | return 1; | |
657 | ||
658 | return 0; | |
659 | } | |
660 | ||
661 | static int prefix_underscores_count(const char *str) | |
662 | { | |
663 | const char *tail = str; | |
664 | ||
a9ece53c | 665 | while (*tail == '_') |
b478b782 LJ |
666 | tail++; |
667 | ||
668 | return tail - str; | |
669 | } | |
670 | ||
f2df3f65 PM |
671 | static int compare_symbols(const void *a, const void *b) |
672 | { | |
673 | const struct sym_entry *sa; | |
674 | const struct sym_entry *sb; | |
675 | int wa, wb; | |
676 | ||
677 | sa = a; | |
678 | sb = b; | |
679 | ||
680 | /* sort by address first */ | |
681 | if (sa->addr > sb->addr) | |
682 | return 1; | |
683 | if (sa->addr < sb->addr) | |
684 | return -1; | |
685 | ||
686 | /* sort by "weakness" type */ | |
687 | wa = (sa->sym[0] == 'w') || (sa->sym[0] == 'W'); | |
688 | wb = (sb->sym[0] == 'w') || (sb->sym[0] == 'W'); | |
689 | if (wa != wb) | |
690 | return wa - wb; | |
691 | ||
b478b782 LJ |
692 | /* sort by "linker script provide" type */ |
693 | wa = may_be_linker_script_provide_symbol(sa); | |
694 | wb = may_be_linker_script_provide_symbol(sb); | |
695 | if (wa != wb) | |
696 | return wa - wb; | |
697 | ||
698 | /* sort by the number of prefix underscores */ | |
699 | wa = prefix_underscores_count((const char *)sa->sym + 1); | |
700 | wb = prefix_underscores_count((const char *)sb->sym + 1); | |
701 | if (wa != wb) | |
702 | return wa - wb; | |
703 | ||
f2df3f65 PM |
704 | /* sort by initial order, so that other symbols are left undisturbed */ |
705 | return sa->start_pos - sb->start_pos; | |
706 | } | |
707 | ||
708 | static void sort_symbols(void) | |
709 | { | |
710 | qsort(table, table_cnt, sizeof(struct sym_entry), compare_symbols); | |
711 | } | |
1da177e4 | 712 | |
c6bda7c9 RR |
713 | static void make_percpus_absolute(void) |
714 | { | |
715 | unsigned int i; | |
716 | ||
717 | for (i = 0; i < table_cnt; i++) | |
8c996940 AB |
718 | if (symbol_in_range(&table[i], &percpu_range, 1)) { |
719 | /* | |
720 | * Keep the 'A' override for percpu symbols to | |
721 | * ensure consistent behavior compared to older | |
722 | * versions of this tool. | |
723 | */ | |
c6bda7c9 | 724 | table[i].sym[0] = 'A'; |
8c996940 AB |
725 | table[i].percpu_absolute = 1; |
726 | } | |
c6bda7c9 RR |
727 | } |
728 | ||
2213e9a6 AB |
729 | /* find the minimum non-absolute symbol address */ |
730 | static void record_relative_base(void) | |
731 | { | |
732 | unsigned int i; | |
733 | ||
734 | relative_base = -1ULL; | |
735 | for (i = 0; i < table_cnt; i++) | |
736 | if (!symbol_absolute(&table[i]) && | |
737 | table[i].addr < relative_base) | |
738 | relative_base = table[i].addr; | |
739 | } | |
740 | ||
b3dbb4ec | 741 | int main(int argc, char **argv) |
1da177e4 | 742 | { |
41f11a4f YS |
743 | if (argc >= 2) { |
744 | int i; | |
745 | for (i = 1; i < argc; i++) { | |
746 | if(strcmp(argv[i], "--all-symbols") == 0) | |
747 | all_symbols = 1; | |
c6bda7c9 RR |
748 | else if (strcmp(argv[i], "--absolute-percpu") == 0) |
749 | absolute_percpu = 1; | |
534c9f2e | 750 | else if (strcmp(argv[i], "--base-relative") == 0) |
2213e9a6 AB |
751 | base_relative = 1; |
752 | else | |
41f11a4f YS |
753 | usage(); |
754 | } | |
755 | } else if (argc != 1) | |
1da177e4 LT |
756 | usage(); |
757 | ||
758 | read_map(stdin); | |
c6bda7c9 RR |
759 | if (absolute_percpu) |
760 | make_percpus_absolute(); | |
2213e9a6 AB |
761 | if (base_relative) |
762 | record_relative_base(); | |
2ea03891 SR |
763 | sort_symbols(); |
764 | optimize_token_table(); | |
1da177e4 LT |
765 | write_src(); |
766 | ||
767 | return 0; | |
768 | } |