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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 | ||
a41333e0 | 21 | #include <stdbool.h> |
1da177e4 LT |
22 | #include <stdio.h> |
23 | #include <stdlib.h> | |
24 | #include <string.h> | |
25 | #include <ctype.h> | |
2213e9a6 | 26 | #include <limits.h> |
1da177e4 | 27 | |
17b1f0de | 28 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0])) |
17b1f0de | 29 | |
9281acea | 30 | #define KSYM_NAME_LEN 128 |
1da177e4 | 31 | |
1da177e4 LT |
32 | struct sym_entry { |
33 | unsigned long long addr; | |
b3dbb4ec | 34 | unsigned int len; |
f2df3f65 | 35 | unsigned int start_pos; |
8c996940 | 36 | unsigned int percpu_absolute; |
9d82973e | 37 | unsigned char sym[]; |
1da177e4 LT |
38 | }; |
39 | ||
78eb7159 KC |
40 | struct addr_range { |
41 | const char *start_sym, *end_sym; | |
17b1f0de MF |
42 | unsigned long long start, end; |
43 | }; | |
44 | ||
45 | static unsigned long long _text; | |
2213e9a6 | 46 | static unsigned long long relative_base; |
78eb7159 | 47 | static struct addr_range text_ranges[] = { |
17b1f0de MF |
48 | { "_stext", "_etext" }, |
49 | { "_sinittext", "_einittext" }, | |
17b1f0de MF |
50 | }; |
51 | #define text_range_text (&text_ranges[0]) | |
52 | #define text_range_inittext (&text_ranges[1]) | |
53 | ||
c6bda7c9 RR |
54 | static struct addr_range percpu_range = { |
55 | "__per_cpu_start", "__per_cpu_end", -1ULL, 0 | |
56 | }; | |
57 | ||
8d605269 | 58 | static struct sym_entry **table; |
b3dbb4ec | 59 | static unsigned int table_size, table_cnt; |
831362fc MY |
60 | static int all_symbols; |
61 | static int absolute_percpu; | |
62 | static int base_relative; | |
1da177e4 | 63 | |
f43e9daa | 64 | static int token_profit[0x10000]; |
1da177e4 LT |
65 | |
66 | /* the table that holds the result of the compression */ | |
f43e9daa MY |
67 | static unsigned char best_table[256][2]; |
68 | static unsigned char best_table_len[256]; | |
1da177e4 LT |
69 | |
70 | ||
b3dbb4ec | 71 | static void usage(void) |
1da177e4 | 72 | { |
f6537f2f | 73 | fprintf(stderr, "Usage: kallsyms [--all-symbols] " |
2213e9a6 | 74 | "[--base-relative] < 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 | { | |
516d980f | 85 | /* Symbol names that exactly match to the following are ignored.*/ |
a41333e0 MY |
86 | static const char * const ignored_symbols[] = { |
87 | /* | |
88 | * Symbols which vary between passes. Passes 1 and 2 must have | |
89 | * identical symbol lists. The kallsyms_* symbols below are | |
90 | * only added after pass 1, they would be included in pass 2 | |
91 | * when --all-symbols is specified so exclude them to get a | |
92 | * stable symbol list. | |
93 | */ | |
94 | "kallsyms_addresses", | |
95 | "kallsyms_offsets", | |
96 | "kallsyms_relative_base", | |
97 | "kallsyms_num_syms", | |
98 | "kallsyms_names", | |
99 | "kallsyms_markers", | |
100 | "kallsyms_token_table", | |
101 | "kallsyms_token_index", | |
102 | /* Exclude linker generated symbols which vary between passes */ | |
103 | "_SDA_BASE_", /* ppc */ | |
104 | "_SDA2_BASE_", /* ppc */ | |
105 | NULL | |
106 | }; | |
107 | ||
516d980f | 108 | /* Symbol names that begin with the following are ignored.*/ |
a41333e0 | 109 | static const char * const ignored_prefixes[] = { |
97261e1e MY |
110 | "$", /* local symbols for ARM, MIPS, etc. */ |
111 | ".LASANPC", /* s390 kasan local symbols */ | |
a41333e0 MY |
112 | "__crc_", /* modversions */ |
113 | "__efistub_", /* arm64 EFI stub namespace */ | |
76217129 | 114 | "__kvm_nvhe_", /* arm64 non-VHE KVM namespace */ |
a41333e0 MY |
115 | NULL |
116 | }; | |
117 | ||
516d980f | 118 | /* Symbol names that end with the following are ignored.*/ |
a41333e0 MY |
119 | static const char * const ignored_suffixes[] = { |
120 | "_from_arm", /* arm */ | |
121 | "_from_thumb", /* arm */ | |
122 | "_veneer", /* arm */ | |
123 | NULL | |
124 | }; | |
125 | ||
516d980f MY |
126 | /* Symbol names that contain the following are ignored.*/ |
127 | static const char * const ignored_matches[] = { | |
128 | ".long_branch.", /* ppc stub */ | |
129 | ".plt_branch.", /* ppc stub */ | |
130 | NULL | |
131 | }; | |
132 | ||
a41333e0 MY |
133 | const char * const *p; |
134 | ||
a41333e0 MY |
135 | for (p = ignored_symbols; *p; p++) |
136 | if (!strcmp(name, *p)) | |
137 | return true; | |
138 | ||
139 | for (p = ignored_prefixes; *p; p++) | |
140 | if (!strncmp(name, *p, strlen(*p))) | |
141 | return true; | |
142 | ||
143 | for (p = ignored_suffixes; *p; p++) { | |
144 | int l = strlen(name) - strlen(*p); | |
145 | ||
146 | if (l >= 0 && !strcmp(name + l, *p)) | |
147 | return true; | |
148 | } | |
149 | ||
516d980f MY |
150 | for (p = ignored_matches; *p; p++) { |
151 | if (strstr(name, *p)) | |
152 | return true; | |
153 | } | |
154 | ||
887df76d MY |
155 | if (type == 'U' || type == 'u') |
156 | return true; | |
157 | /* exclude debugging symbols */ | |
158 | if (type == 'N' || type == 'n') | |
159 | return true; | |
160 | ||
161 | if (toupper(type) == 'A') { | |
162 | /* Keep these useful absolute symbols */ | |
163 | if (strcmp(name, "__kernel_syscall_via_break") && | |
164 | strcmp(name, "__kernel_syscall_via_epc") && | |
165 | strcmp(name, "__kernel_sigtramp") && | |
166 | strcmp(name, "__gp")) | |
167 | return true; | |
168 | } | |
169 | ||
a41333e0 MY |
170 | return false; |
171 | } | |
172 | ||
b6233d0d MY |
173 | static void check_symbol_range(const char *sym, unsigned long long addr, |
174 | struct addr_range *ranges, int entries) | |
17b1f0de MF |
175 | { |
176 | size_t i; | |
78eb7159 | 177 | struct addr_range *ar; |
17b1f0de | 178 | |
78eb7159 KC |
179 | for (i = 0; i < entries; ++i) { |
180 | ar = &ranges[i]; | |
17b1f0de | 181 | |
78eb7159 KC |
182 | if (strcmp(sym, ar->start_sym) == 0) { |
183 | ar->start = addr; | |
b6233d0d | 184 | return; |
78eb7159 KC |
185 | } else if (strcmp(sym, ar->end_sym) == 0) { |
186 | ar->end = addr; | |
b6233d0d | 187 | return; |
17b1f0de MF |
188 | } |
189 | } | |
17b1f0de MF |
190 | } |
191 | ||
8d605269 | 192 | static struct sym_entry *read_symbol(FILE *in) |
1da177e4 | 193 | { |
be9f6133 | 194 | char name[500], type; |
8d605269 MY |
195 | unsigned long long addr; |
196 | unsigned int len; | |
197 | struct sym_entry *sym; | |
1da177e4 LT |
198 | int rc; |
199 | ||
8d605269 | 200 | rc = fscanf(in, "%llx %c %499s\n", &addr, &type, name); |
1da177e4 | 201 | if (rc != 3) { |
be9f6133 | 202 | if (rc != EOF && fgets(name, 500, in) == NULL) |
ef894870 | 203 | fprintf(stderr, "Read error or end of file.\n"); |
8d605269 | 204 | return NULL; |
1da177e4 | 205 | } |
be9f6133 | 206 | if (strlen(name) >= KSYM_NAME_LEN) { |
6db2983c | 207 | fprintf(stderr, "Symbol %s too long for kallsyms (%zu >= %d).\n" |
bb66fc67 | 208 | "Please increase KSYM_NAME_LEN both in kernel and kallsyms.c\n", |
be9f6133 | 209 | name, strlen(name), KSYM_NAME_LEN); |
8d605269 | 210 | return NULL; |
f3462aa9 | 211 | } |
1da177e4 | 212 | |
be9f6133 | 213 | if (strcmp(name, "_text") == 0) |
8d605269 | 214 | _text = addr; |
b6233d0d | 215 | |
7883a143 MP |
216 | /* Ignore most absolute/undefined (?) symbols. */ |
217 | if (is_ignored_symbol(name, type)) | |
218 | return NULL; | |
219 | ||
8d605269 MY |
220 | check_symbol_range(name, addr, text_ranges, ARRAY_SIZE(text_ranges)); |
221 | check_symbol_range(name, addr, &percpu_range, 1); | |
1da177e4 LT |
222 | |
223 | /* include the type field in the symbol name, so that it gets | |
224 | * compressed together */ | |
8d605269 MY |
225 | |
226 | len = strlen(name) + 1; | |
227 | ||
9d1b3895 | 228 | sym = malloc(sizeof(*sym) + len + 1); |
8d605269 | 229 | if (!sym) { |
f1a136e0 JJ |
230 | fprintf(stderr, "kallsyms failure: " |
231 | "unable to allocate required amount of memory\n"); | |
232 | exit(EXIT_FAILURE); | |
233 | } | |
8d605269 MY |
234 | sym->addr = addr; |
235 | sym->len = len; | |
236 | sym->sym[0] = type; | |
9d1b3895 | 237 | strcpy(sym_name(sym), name); |
8d605269 | 238 | sym->percpu_absolute = 0; |
8c996940 | 239 | |
8d605269 | 240 | return sym; |
1da177e4 LT |
241 | } |
242 | ||
4bfe2b78 MY |
243 | static int symbol_in_range(const struct sym_entry *s, |
244 | const struct addr_range *ranges, int entries) | |
17b1f0de MF |
245 | { |
246 | size_t i; | |
4bfe2b78 | 247 | const struct addr_range *ar; |
17b1f0de | 248 | |
78eb7159 KC |
249 | for (i = 0; i < entries; ++i) { |
250 | ar = &ranges[i]; | |
17b1f0de | 251 | |
78eb7159 | 252 | if (s->addr >= ar->start && s->addr <= ar->end) |
ac6ca5c8 | 253 | return 1; |
17b1f0de MF |
254 | } |
255 | ||
ac6ca5c8 | 256 | return 0; |
17b1f0de MF |
257 | } |
258 | ||
4bfe2b78 | 259 | static int symbol_valid(const struct sym_entry *s) |
1da177e4 | 260 | { |
29e55ad3 | 261 | const char *name = sym_name(s); |
bd8b22d2 | 262 | |
1da177e4 LT |
263 | /* if --all-symbols is not specified, then symbols outside the text |
264 | * and inittext sections are discarded */ | |
265 | if (!all_symbols) { | |
78eb7159 KC |
266 | if (symbol_in_range(s, text_ranges, |
267 | ARRAY_SIZE(text_ranges)) == 0) | |
1da177e4 LT |
268 | return 0; |
269 | /* Corner case. Discard any symbols with the same value as | |
a3b81113 RG |
270 | * _etext _einittext; they can move between pass 1 and 2 when |
271 | * the kallsyms data are added. If these symbols move then | |
272 | * they may get dropped in pass 2, which breaks the kallsyms | |
273 | * rules. | |
1da177e4 | 274 | */ |
17b1f0de | 275 | if ((s->addr == text_range_text->end && |
29e55ad3 | 276 | strcmp(name, text_range_text->end_sym)) || |
17b1f0de | 277 | (s->addr == text_range_inittext->end && |
29e55ad3 | 278 | strcmp(name, text_range_inittext->end_sym))) |
1da177e4 LT |
279 | return 0; |
280 | } | |
281 | ||
1da177e4 LT |
282 | return 1; |
283 | } | |
284 | ||
5e5c4fa7 MY |
285 | /* remove all the invalid symbols from the table */ |
286 | static void shrink_table(void) | |
287 | { | |
288 | unsigned int i, pos; | |
289 | ||
290 | pos = 0; | |
291 | for (i = 0; i < table_cnt; i++) { | |
8d605269 | 292 | if (symbol_valid(table[i])) { |
5e5c4fa7 MY |
293 | if (pos != i) |
294 | table[pos] = table[i]; | |
295 | pos++; | |
296 | } else { | |
8d605269 | 297 | free(table[i]); |
5e5c4fa7 MY |
298 | } |
299 | } | |
300 | table_cnt = pos; | |
301 | ||
302 | /* When valid symbol is not registered, exit to error */ | |
303 | if (!table_cnt) { | |
304 | fprintf(stderr, "No valid symbol.\n"); | |
305 | exit(1); | |
306 | } | |
307 | } | |
308 | ||
b3dbb4ec | 309 | static void read_map(FILE *in) |
1da177e4 | 310 | { |
8d605269 MY |
311 | struct sym_entry *sym; |
312 | ||
1da177e4 | 313 | while (!feof(in)) { |
8d605269 MY |
314 | sym = read_symbol(in); |
315 | if (!sym) | |
316 | continue; | |
317 | ||
318 | sym->start_pos = table_cnt; | |
319 | ||
b3dbb4ec PM |
320 | if (table_cnt >= table_size) { |
321 | table_size += 10000; | |
322 | table = realloc(table, sizeof(*table) * table_size); | |
1da177e4 LT |
323 | if (!table) { |
324 | fprintf(stderr, "out of memory\n"); | |
325 | exit (1); | |
326 | } | |
327 | } | |
8d605269 MY |
328 | |
329 | table[table_cnt++] = sym; | |
1da177e4 LT |
330 | } |
331 | } | |
332 | ||
4bfe2b78 | 333 | static void output_label(const char *label) |
1da177e4 | 334 | { |
534c9f2e | 335 | printf(".globl %s\n", label); |
1da177e4 | 336 | printf("\tALGN\n"); |
534c9f2e | 337 | printf("%s:\n", label); |
1da177e4 LT |
338 | } |
339 | ||
fd2ab2f6 MY |
340 | /* Provide proper symbols relocatability by their '_text' relativeness. */ |
341 | static void output_address(unsigned long long addr) | |
342 | { | |
343 | if (_text <= addr) | |
344 | printf("\tPTR\t_text + %#llx\n", addr - _text); | |
345 | else | |
346 | printf("\tPTR\t_text - %#llx\n", _text - addr); | |
347 | } | |
348 | ||
1da177e4 LT |
349 | /* uncompress a compressed symbol. When this function is called, the best table |
350 | * might still be compressed itself, so the function needs to be recursive */ | |
4bfe2b78 | 351 | static int expand_symbol(const unsigned char *data, int len, char *result) |
1da177e4 LT |
352 | { |
353 | int c, rlen, total=0; | |
354 | ||
355 | while (len) { | |
356 | c = *data; | |
357 | /* if the table holds a single char that is the same as the one | |
358 | * we are looking for, then end the search */ | |
359 | if (best_table[c][0]==c && best_table_len[c]==1) { | |
360 | *result++ = c; | |
361 | total++; | |
362 | } else { | |
363 | /* if not, recurse and expand */ | |
364 | rlen = expand_symbol(best_table[c], best_table_len[c], result); | |
365 | total += rlen; | |
366 | result += rlen; | |
367 | } | |
368 | data++; | |
369 | len--; | |
370 | } | |
371 | *result=0; | |
372 | ||
373 | return total; | |
374 | } | |
375 | ||
4bfe2b78 | 376 | static int symbol_absolute(const struct sym_entry *s) |
78eb7159 | 377 | { |
8c996940 | 378 | return s->percpu_absolute; |
78eb7159 KC |
379 | } |
380 | ||
b3dbb4ec | 381 | static void write_src(void) |
1da177e4 | 382 | { |
b3dbb4ec | 383 | unsigned int i, k, off; |
1da177e4 LT |
384 | unsigned int best_idx[256]; |
385 | unsigned int *markers; | |
9281acea | 386 | char buf[KSYM_NAME_LEN]; |
1da177e4 | 387 | |
500193ec | 388 | printf("#include <asm/bitsperlong.h>\n"); |
1da177e4 LT |
389 | printf("#if BITS_PER_LONG == 64\n"); |
390 | printf("#define PTR .quad\n"); | |
72d3ebb9 | 391 | printf("#define ALGN .balign 8\n"); |
1da177e4 LT |
392 | printf("#else\n"); |
393 | printf("#define PTR .long\n"); | |
72d3ebb9 | 394 | printf("#define ALGN .balign 4\n"); |
1da177e4 LT |
395 | printf("#endif\n"); |
396 | ||
aad09470 | 397 | printf("\t.section .rodata, \"a\"\n"); |
1da177e4 | 398 | |
2213e9a6 AB |
399 | if (!base_relative) |
400 | output_label("kallsyms_addresses"); | |
401 | else | |
402 | output_label("kallsyms_offsets"); | |
403 | ||
b3dbb4ec | 404 | for (i = 0; i < table_cnt; i++) { |
2213e9a6 | 405 | if (base_relative) { |
fd2ab2f6 MY |
406 | /* |
407 | * Use the offset relative to the lowest value | |
408 | * encountered of all relative symbols, and emit | |
409 | * non-relocatable fixed offsets that will be fixed | |
410 | * up at runtime. | |
411 | */ | |
412 | ||
2213e9a6 AB |
413 | long long offset; |
414 | int overflow; | |
415 | ||
416 | if (!absolute_percpu) { | |
8d605269 | 417 | offset = table[i]->addr - relative_base; |
2213e9a6 | 418 | overflow = (offset < 0 || offset > UINT_MAX); |
8d605269 MY |
419 | } else if (symbol_absolute(table[i])) { |
420 | offset = table[i]->addr; | |
2213e9a6 AB |
421 | overflow = (offset < 0 || offset > INT_MAX); |
422 | } else { | |
8d605269 | 423 | offset = relative_base - table[i]->addr - 1; |
2213e9a6 AB |
424 | overflow = (offset < INT_MIN || offset >= 0); |
425 | } | |
426 | if (overflow) { | |
427 | fprintf(stderr, "kallsyms failure: " | |
428 | "%s symbol value %#llx out of range in relative mode\n", | |
8d605269 MY |
429 | symbol_absolute(table[i]) ? "absolute" : "relative", |
430 | table[i]->addr); | |
2213e9a6 AB |
431 | exit(EXIT_FAILURE); |
432 | } | |
433 | printf("\t.long\t%#x\n", (int)offset); | |
8d605269 MY |
434 | } else if (!symbol_absolute(table[i])) { |
435 | output_address(table[i]->addr); | |
fd593d12 | 436 | } else { |
8d605269 | 437 | printf("\tPTR\t%#llx\n", table[i]->addr); |
fd593d12 | 438 | } |
1da177e4 LT |
439 | } |
440 | printf("\n"); | |
441 | ||
2213e9a6 AB |
442 | if (base_relative) { |
443 | output_label("kallsyms_relative_base"); | |
fd2ab2f6 | 444 | output_address(relative_base); |
2213e9a6 AB |
445 | printf("\n"); |
446 | } | |
447 | ||
1da177e4 | 448 | output_label("kallsyms_num_syms"); |
80ffbaa5 | 449 | printf("\t.long\t%u\n", table_cnt); |
1da177e4 LT |
450 | printf("\n"); |
451 | ||
452 | /* table of offset markers, that give the offset in the compressed stream | |
453 | * every 256 symbols */ | |
f1a136e0 JJ |
454 | markers = malloc(sizeof(unsigned int) * ((table_cnt + 255) / 256)); |
455 | if (!markers) { | |
456 | fprintf(stderr, "kallsyms failure: " | |
457 | "unable to allocate required memory\n"); | |
458 | exit(EXIT_FAILURE); | |
459 | } | |
1da177e4 LT |
460 | |
461 | output_label("kallsyms_names"); | |
1da177e4 | 462 | off = 0; |
b3dbb4ec PM |
463 | for (i = 0; i < table_cnt; i++) { |
464 | if ((i & 0xFF) == 0) | |
465 | markers[i >> 8] = off; | |
1da177e4 | 466 | |
8d605269 MY |
467 | printf("\t.byte 0x%02x", table[i]->len); |
468 | for (k = 0; k < table[i]->len; k++) | |
469 | printf(", 0x%02x", table[i]->sym[k]); | |
1da177e4 LT |
470 | printf("\n"); |
471 | ||
8d605269 | 472 | off += table[i]->len + 1; |
1da177e4 LT |
473 | } |
474 | printf("\n"); | |
475 | ||
476 | output_label("kallsyms_markers"); | |
b3dbb4ec | 477 | for (i = 0; i < ((table_cnt + 255) >> 8); i++) |
80ffbaa5 | 478 | printf("\t.long\t%u\n", markers[i]); |
1da177e4 LT |
479 | printf("\n"); |
480 | ||
481 | free(markers); | |
482 | ||
483 | output_label("kallsyms_token_table"); | |
484 | off = 0; | |
485 | for (i = 0; i < 256; i++) { | |
486 | best_idx[i] = off; | |
b3dbb4ec | 487 | expand_symbol(best_table[i], best_table_len[i], buf); |
1da177e4 LT |
488 | printf("\t.asciz\t\"%s\"\n", buf); |
489 | off += strlen(buf) + 1; | |
490 | } | |
491 | printf("\n"); | |
492 | ||
493 | output_label("kallsyms_token_index"); | |
494 | for (i = 0; i < 256; i++) | |
495 | printf("\t.short\t%d\n", best_idx[i]); | |
496 | printf("\n"); | |
497 | } | |
498 | ||
499 | ||
500 | /* table lookup compression functions */ | |
501 | ||
1da177e4 | 502 | /* count all the possible tokens in a symbol */ |
4bfe2b78 | 503 | static void learn_symbol(const unsigned char *symbol, int len) |
1da177e4 LT |
504 | { |
505 | int i; | |
506 | ||
507 | for (i = 0; i < len - 1; i++) | |
b3dbb4ec | 508 | token_profit[ symbol[i] + (symbol[i + 1] << 8) ]++; |
1da177e4 LT |
509 | } |
510 | ||
511 | /* decrease the count for all the possible tokens in a symbol */ | |
4bfe2b78 | 512 | static void forget_symbol(const unsigned char *symbol, int len) |
1da177e4 LT |
513 | { |
514 | int i; | |
515 | ||
516 | for (i = 0; i < len - 1; i++) | |
b3dbb4ec | 517 | token_profit[ symbol[i] + (symbol[i + 1] << 8) ]--; |
1da177e4 LT |
518 | } |
519 | ||
5e5c4fa7 | 520 | /* do the initial token count */ |
1da177e4 LT |
521 | static void build_initial_tok_table(void) |
522 | { | |
5e5c4fa7 | 523 | unsigned int i; |
1da177e4 | 524 | |
5e5c4fa7 | 525 | for (i = 0; i < table_cnt; i++) |
8d605269 | 526 | learn_symbol(table[i]->sym, table[i]->len); |
1da177e4 LT |
527 | } |
528 | ||
2558c138 | 529 | static unsigned char *find_token(unsigned char *str, int len, |
4bfe2b78 | 530 | const unsigned char *token) |
7c5d249a PM |
531 | { |
532 | int i; | |
533 | ||
534 | for (i = 0; i < len - 1; i++) { | |
535 | if (str[i] == token[0] && str[i+1] == token[1]) | |
536 | return &str[i]; | |
537 | } | |
538 | return NULL; | |
539 | } | |
540 | ||
1da177e4 LT |
541 | /* replace a given token in all the valid symbols. Use the sampled symbols |
542 | * to update the counts */ | |
4bfe2b78 | 543 | static void compress_symbols(const unsigned char *str, int idx) |
1da177e4 | 544 | { |
b3dbb4ec PM |
545 | unsigned int i, len, size; |
546 | unsigned char *p1, *p2; | |
1da177e4 | 547 | |
b3dbb4ec | 548 | for (i = 0; i < table_cnt; i++) { |
1da177e4 | 549 | |
8d605269 MY |
550 | len = table[i]->len; |
551 | p1 = table[i]->sym; | |
b3dbb4ec PM |
552 | |
553 | /* find the token on the symbol */ | |
7c5d249a | 554 | p2 = find_token(p1, len, str); |
b3dbb4ec PM |
555 | if (!p2) continue; |
556 | ||
557 | /* decrease the counts for this symbol's tokens */ | |
8d605269 | 558 | forget_symbol(table[i]->sym, len); |
b3dbb4ec PM |
559 | |
560 | size = len; | |
1da177e4 LT |
561 | |
562 | do { | |
b3dbb4ec PM |
563 | *p2 = idx; |
564 | p2++; | |
565 | size -= (p2 - p1); | |
566 | memmove(p2, p2 + 1, size); | |
567 | p1 = p2; | |
568 | len--; | |
569 | ||
570 | if (size < 2) break; | |
571 | ||
1da177e4 | 572 | /* find the token on the symbol */ |
7c5d249a | 573 | p2 = find_token(p1, size, str); |
1da177e4 | 574 | |
b3dbb4ec | 575 | } while (p2); |
1da177e4 | 576 | |
8d605269 | 577 | table[i]->len = len; |
1da177e4 | 578 | |
b3dbb4ec | 579 | /* increase the counts for this symbol's new tokens */ |
8d605269 | 580 | learn_symbol(table[i]->sym, len); |
1da177e4 LT |
581 | } |
582 | } | |
583 | ||
584 | /* search the token with the maximum profit */ | |
b3dbb4ec | 585 | static int find_best_token(void) |
1da177e4 | 586 | { |
b3dbb4ec | 587 | int i, best, bestprofit; |
1da177e4 LT |
588 | |
589 | bestprofit=-10000; | |
b3dbb4ec | 590 | best = 0; |
1da177e4 | 591 | |
b3dbb4ec PM |
592 | for (i = 0; i < 0x10000; i++) { |
593 | if (token_profit[i] > bestprofit) { | |
594 | best = i; | |
595 | bestprofit = token_profit[i]; | |
1da177e4 | 596 | } |
1da177e4 | 597 | } |
1da177e4 LT |
598 | return best; |
599 | } | |
600 | ||
601 | /* this is the core of the algorithm: calculate the "best" table */ | |
602 | static void optimize_result(void) | |
603 | { | |
b3dbb4ec | 604 | int i, best; |
1da177e4 LT |
605 | |
606 | /* using the '\0' symbol last allows compress_symbols to use standard | |
607 | * fast string functions */ | |
608 | for (i = 255; i >= 0; i--) { | |
609 | ||
610 | /* if this table slot is empty (it is not used by an actual | |
611 | * original char code */ | |
612 | if (!best_table_len[i]) { | |
613 | ||
cbf7a90e | 614 | /* find the token with the best profit value */ |
1da177e4 | 615 | best = find_best_token(); |
e0a04b11 XW |
616 | if (token_profit[best] == 0) |
617 | break; | |
1da177e4 LT |
618 | |
619 | /* place it in the "best" table */ | |
b3dbb4ec PM |
620 | best_table_len[i] = 2; |
621 | best_table[i][0] = best & 0xFF; | |
622 | best_table[i][1] = (best >> 8) & 0xFF; | |
1da177e4 LT |
623 | |
624 | /* replace this token in all the valid symbols */ | |
b3dbb4ec | 625 | compress_symbols(best_table[i], i); |
1da177e4 LT |
626 | } |
627 | } | |
628 | } | |
629 | ||
630 | /* start by placing the symbols that are actually used on the table */ | |
631 | static void insert_real_symbols_in_table(void) | |
632 | { | |
b3dbb4ec | 633 | unsigned int i, j, c; |
1da177e4 | 634 | |
b3dbb4ec | 635 | for (i = 0; i < table_cnt; i++) { |
8d605269 MY |
636 | for (j = 0; j < table[i]->len; j++) { |
637 | c = table[i]->sym[j]; | |
b3dbb4ec PM |
638 | best_table[c][0]=c; |
639 | best_table_len[c]=1; | |
1da177e4 LT |
640 | } |
641 | } | |
642 | } | |
643 | ||
644 | static void optimize_token_table(void) | |
645 | { | |
1da177e4 LT |
646 | build_initial_tok_table(); |
647 | ||
648 | insert_real_symbols_in_table(); | |
649 | ||
650 | optimize_result(); | |
651 | } | |
652 | ||
b478b782 LJ |
653 | /* guess for "linker script provide" symbol */ |
654 | static int may_be_linker_script_provide_symbol(const struct sym_entry *se) | |
655 | { | |
29e55ad3 | 656 | const char *symbol = sym_name(se); |
b478b782 LJ |
657 | int len = se->len - 1; |
658 | ||
659 | if (len < 8) | |
660 | return 0; | |
661 | ||
662 | if (symbol[0] != '_' || symbol[1] != '_') | |
663 | return 0; | |
664 | ||
665 | /* __start_XXXXX */ | |
666 | if (!memcmp(symbol + 2, "start_", 6)) | |
667 | return 1; | |
668 | ||
669 | /* __stop_XXXXX */ | |
670 | if (!memcmp(symbol + 2, "stop_", 5)) | |
671 | return 1; | |
672 | ||
673 | /* __end_XXXXX */ | |
674 | if (!memcmp(symbol + 2, "end_", 4)) | |
675 | return 1; | |
676 | ||
677 | /* __XXXXX_start */ | |
678 | if (!memcmp(symbol + len - 6, "_start", 6)) | |
679 | return 1; | |
680 | ||
681 | /* __XXXXX_end */ | |
682 | if (!memcmp(symbol + len - 4, "_end", 4)) | |
683 | return 1; | |
684 | ||
685 | return 0; | |
686 | } | |
687 | ||
f2df3f65 PM |
688 | static int compare_symbols(const void *a, const void *b) |
689 | { | |
8d605269 MY |
690 | const struct sym_entry *sa = *(const struct sym_entry **)a; |
691 | const struct sym_entry *sb = *(const struct sym_entry **)b; | |
f2df3f65 PM |
692 | int wa, wb; |
693 | ||
f2df3f65 PM |
694 | /* sort by address first */ |
695 | if (sa->addr > sb->addr) | |
696 | return 1; | |
697 | if (sa->addr < sb->addr) | |
698 | return -1; | |
699 | ||
700 | /* sort by "weakness" type */ | |
701 | wa = (sa->sym[0] == 'w') || (sa->sym[0] == 'W'); | |
702 | wb = (sb->sym[0] == 'w') || (sb->sym[0] == 'W'); | |
703 | if (wa != wb) | |
704 | return wa - wb; | |
705 | ||
b478b782 LJ |
706 | /* sort by "linker script provide" type */ |
707 | wa = may_be_linker_script_provide_symbol(sa); | |
708 | wb = may_be_linker_script_provide_symbol(sb); | |
709 | if (wa != wb) | |
710 | return wa - wb; | |
711 | ||
712 | /* sort by the number of prefix underscores */ | |
aa915245 MY |
713 | wa = strspn(sym_name(sa), "_"); |
714 | wb = strspn(sym_name(sb), "_"); | |
b478b782 LJ |
715 | if (wa != wb) |
716 | return wa - wb; | |
717 | ||
f2df3f65 PM |
718 | /* sort by initial order, so that other symbols are left undisturbed */ |
719 | return sa->start_pos - sb->start_pos; | |
720 | } | |
721 | ||
722 | static void sort_symbols(void) | |
723 | { | |
8d605269 | 724 | qsort(table, table_cnt, sizeof(table[0]), compare_symbols); |
f2df3f65 | 725 | } |
1da177e4 | 726 | |
c6bda7c9 RR |
727 | static void make_percpus_absolute(void) |
728 | { | |
729 | unsigned int i; | |
730 | ||
731 | for (i = 0; i < table_cnt; i++) | |
8d605269 | 732 | if (symbol_in_range(table[i], &percpu_range, 1)) { |
8c996940 AB |
733 | /* |
734 | * Keep the 'A' override for percpu symbols to | |
735 | * ensure consistent behavior compared to older | |
736 | * versions of this tool. | |
737 | */ | |
8d605269 MY |
738 | table[i]->sym[0] = 'A'; |
739 | table[i]->percpu_absolute = 1; | |
8c996940 | 740 | } |
c6bda7c9 RR |
741 | } |
742 | ||
2213e9a6 AB |
743 | /* find the minimum non-absolute symbol address */ |
744 | static void record_relative_base(void) | |
745 | { | |
746 | unsigned int i; | |
747 | ||
2213e9a6 | 748 | for (i = 0; i < table_cnt; i++) |
8d605269 | 749 | if (!symbol_absolute(table[i])) { |
f34ea029 MY |
750 | /* |
751 | * The table is sorted by address. | |
752 | * Take the first non-absolute symbol value. | |
753 | */ | |
8d605269 | 754 | relative_base = table[i]->addr; |
f34ea029 MY |
755 | return; |
756 | } | |
2213e9a6 AB |
757 | } |
758 | ||
b3dbb4ec | 759 | int main(int argc, char **argv) |
1da177e4 | 760 | { |
41f11a4f YS |
761 | if (argc >= 2) { |
762 | int i; | |
763 | for (i = 1; i < argc; i++) { | |
764 | if(strcmp(argv[i], "--all-symbols") == 0) | |
765 | all_symbols = 1; | |
c6bda7c9 RR |
766 | else if (strcmp(argv[i], "--absolute-percpu") == 0) |
767 | absolute_percpu = 1; | |
534c9f2e | 768 | else if (strcmp(argv[i], "--base-relative") == 0) |
2213e9a6 AB |
769 | base_relative = 1; |
770 | else | |
41f11a4f YS |
771 | usage(); |
772 | } | |
773 | } else if (argc != 1) | |
1da177e4 LT |
774 | usage(); |
775 | ||
776 | read_map(stdin); | |
5e5c4fa7 | 777 | shrink_table(); |
c6bda7c9 RR |
778 | if (absolute_percpu) |
779 | make_percpus_absolute(); | |
f34ea029 | 780 | sort_symbols(); |
2213e9a6 AB |
781 | if (base_relative) |
782 | record_relative_base(); | |
2ea03891 | 783 | optimize_token_table(); |
1da177e4 LT |
784 | write_src(); |
785 | ||
786 | return 0; | |
787 | } |