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 | * | |
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 | { |
8d3a7507 | 73 | fprintf(stderr, "Usage: kallsyms [--all-symbols] [--absolute-percpu] " |
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 | 110 | "$", /* local symbols for ARM, MIPS, etc. */ |
d4c85864 | 111 | ".L", /* local labels, .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc. */ |
a41333e0 MY |
112 | "__crc_", /* modversions */ |
113 | "__efistub_", /* arm64 EFI stub namespace */ | |
6ccf9cb5 KS |
114 | "__kvm_nvhe_$", /* arm64 local symbols in non-VHE KVM namespace */ |
115 | "__kvm_nvhe_.L", /* arm64 local symbols in non-VHE KVM namespace */ | |
efe6e306 AB |
116 | "__AArch64ADRPThunk_", /* arm64 lld */ |
117 | "__ARMV5PILongThunk_", /* arm lld */ | |
118 | "__ARMV7PILongThunk_", | |
119 | "__ThumbV7PILongThunk_", | |
120 | "__LA25Thunk_", /* mips lld */ | |
121 | "__microLA25Thunk_", | |
a41333e0 MY |
122 | NULL |
123 | }; | |
124 | ||
516d980f | 125 | /* Symbol names that end with the following are ignored.*/ |
a41333e0 MY |
126 | static const char * const ignored_suffixes[] = { |
127 | "_from_arm", /* arm */ | |
128 | "_from_thumb", /* arm */ | |
129 | "_veneer", /* arm */ | |
130 | NULL | |
131 | }; | |
132 | ||
516d980f MY |
133 | /* Symbol names that contain the following are ignored.*/ |
134 | static const char * const ignored_matches[] = { | |
135 | ".long_branch.", /* ppc stub */ | |
136 | ".plt_branch.", /* ppc stub */ | |
137 | NULL | |
138 | }; | |
139 | ||
a41333e0 MY |
140 | const char * const *p; |
141 | ||
a41333e0 MY |
142 | for (p = ignored_symbols; *p; p++) |
143 | if (!strcmp(name, *p)) | |
144 | return true; | |
145 | ||
146 | for (p = ignored_prefixes; *p; p++) | |
147 | if (!strncmp(name, *p, strlen(*p))) | |
148 | return true; | |
149 | ||
150 | for (p = ignored_suffixes; *p; p++) { | |
151 | int l = strlen(name) - strlen(*p); | |
152 | ||
153 | if (l >= 0 && !strcmp(name + l, *p)) | |
154 | return true; | |
155 | } | |
156 | ||
516d980f MY |
157 | for (p = ignored_matches; *p; p++) { |
158 | if (strstr(name, *p)) | |
159 | return true; | |
160 | } | |
161 | ||
887df76d MY |
162 | if (type == 'U' || type == 'u') |
163 | return true; | |
164 | /* exclude debugging symbols */ | |
165 | if (type == 'N' || type == 'n') | |
166 | return true; | |
167 | ||
168 | if (toupper(type) == 'A') { | |
169 | /* Keep these useful absolute symbols */ | |
170 | if (strcmp(name, "__kernel_syscall_via_break") && | |
171 | strcmp(name, "__kernel_syscall_via_epc") && | |
172 | strcmp(name, "__kernel_sigtramp") && | |
173 | strcmp(name, "__gp")) | |
174 | return true; | |
175 | } | |
176 | ||
a41333e0 MY |
177 | return false; |
178 | } | |
179 | ||
b6233d0d MY |
180 | static void check_symbol_range(const char *sym, unsigned long long addr, |
181 | struct addr_range *ranges, int entries) | |
17b1f0de MF |
182 | { |
183 | size_t i; | |
78eb7159 | 184 | struct addr_range *ar; |
17b1f0de | 185 | |
78eb7159 KC |
186 | for (i = 0; i < entries; ++i) { |
187 | ar = &ranges[i]; | |
17b1f0de | 188 | |
78eb7159 KC |
189 | if (strcmp(sym, ar->start_sym) == 0) { |
190 | ar->start = addr; | |
b6233d0d | 191 | return; |
78eb7159 KC |
192 | } else if (strcmp(sym, ar->end_sym) == 0) { |
193 | ar->end = addr; | |
b6233d0d | 194 | return; |
17b1f0de MF |
195 | } |
196 | } | |
17b1f0de MF |
197 | } |
198 | ||
8d605269 | 199 | static struct sym_entry *read_symbol(FILE *in) |
1da177e4 | 200 | { |
be9f6133 | 201 | char name[500], type; |
8d605269 MY |
202 | unsigned long long addr; |
203 | unsigned int len; | |
204 | struct sym_entry *sym; | |
1da177e4 LT |
205 | int rc; |
206 | ||
8d605269 | 207 | rc = fscanf(in, "%llx %c %499s\n", &addr, &type, name); |
1da177e4 | 208 | if (rc != 3) { |
be9f6133 | 209 | if (rc != EOF && fgets(name, 500, in) == NULL) |
ef894870 | 210 | fprintf(stderr, "Read error or end of file.\n"); |
8d605269 | 211 | return NULL; |
1da177e4 | 212 | } |
be9f6133 | 213 | if (strlen(name) >= KSYM_NAME_LEN) { |
6db2983c | 214 | fprintf(stderr, "Symbol %s too long for kallsyms (%zu >= %d).\n" |
bb66fc67 | 215 | "Please increase KSYM_NAME_LEN both in kernel and kallsyms.c\n", |
be9f6133 | 216 | name, strlen(name), KSYM_NAME_LEN); |
8d605269 | 217 | return NULL; |
f3462aa9 | 218 | } |
1da177e4 | 219 | |
be9f6133 | 220 | if (strcmp(name, "_text") == 0) |
8d605269 | 221 | _text = addr; |
b6233d0d | 222 | |
7883a143 MP |
223 | /* Ignore most absolute/undefined (?) symbols. */ |
224 | if (is_ignored_symbol(name, type)) | |
225 | return NULL; | |
226 | ||
8d605269 MY |
227 | check_symbol_range(name, addr, text_ranges, ARRAY_SIZE(text_ranges)); |
228 | check_symbol_range(name, addr, &percpu_range, 1); | |
1da177e4 LT |
229 | |
230 | /* include the type field in the symbol name, so that it gets | |
231 | * compressed together */ | |
8d605269 MY |
232 | |
233 | len = strlen(name) + 1; | |
234 | ||
9d1b3895 | 235 | sym = malloc(sizeof(*sym) + len + 1); |
8d605269 | 236 | if (!sym) { |
f1a136e0 JJ |
237 | fprintf(stderr, "kallsyms failure: " |
238 | "unable to allocate required amount of memory\n"); | |
239 | exit(EXIT_FAILURE); | |
240 | } | |
8d605269 MY |
241 | sym->addr = addr; |
242 | sym->len = len; | |
243 | sym->sym[0] = type; | |
9d1b3895 | 244 | strcpy(sym_name(sym), name); |
8d605269 | 245 | sym->percpu_absolute = 0; |
8c996940 | 246 | |
8d605269 | 247 | return sym; |
1da177e4 LT |
248 | } |
249 | ||
4bfe2b78 MY |
250 | static int symbol_in_range(const struct sym_entry *s, |
251 | const struct addr_range *ranges, int entries) | |
17b1f0de MF |
252 | { |
253 | size_t i; | |
4bfe2b78 | 254 | const struct addr_range *ar; |
17b1f0de | 255 | |
78eb7159 KC |
256 | for (i = 0; i < entries; ++i) { |
257 | ar = &ranges[i]; | |
17b1f0de | 258 | |
78eb7159 | 259 | if (s->addr >= ar->start && s->addr <= ar->end) |
ac6ca5c8 | 260 | return 1; |
17b1f0de MF |
261 | } |
262 | ||
ac6ca5c8 | 263 | return 0; |
17b1f0de MF |
264 | } |
265 | ||
4bfe2b78 | 266 | static int symbol_valid(const struct sym_entry *s) |
1da177e4 | 267 | { |
29e55ad3 | 268 | const char *name = sym_name(s); |
bd8b22d2 | 269 | |
1da177e4 LT |
270 | /* if --all-symbols is not specified, then symbols outside the text |
271 | * and inittext sections are discarded */ | |
272 | if (!all_symbols) { | |
78eb7159 KC |
273 | if (symbol_in_range(s, text_ranges, |
274 | ARRAY_SIZE(text_ranges)) == 0) | |
1da177e4 LT |
275 | return 0; |
276 | /* Corner case. Discard any symbols with the same value as | |
a3b81113 RG |
277 | * _etext _einittext; they can move between pass 1 and 2 when |
278 | * the kallsyms data are added. If these symbols move then | |
279 | * they may get dropped in pass 2, which breaks the kallsyms | |
280 | * rules. | |
1da177e4 | 281 | */ |
17b1f0de | 282 | if ((s->addr == text_range_text->end && |
29e55ad3 | 283 | strcmp(name, text_range_text->end_sym)) || |
17b1f0de | 284 | (s->addr == text_range_inittext->end && |
29e55ad3 | 285 | strcmp(name, text_range_inittext->end_sym))) |
1da177e4 LT |
286 | return 0; |
287 | } | |
288 | ||
1da177e4 LT |
289 | return 1; |
290 | } | |
291 | ||
5e5c4fa7 MY |
292 | /* remove all the invalid symbols from the table */ |
293 | static void shrink_table(void) | |
294 | { | |
295 | unsigned int i, pos; | |
296 | ||
297 | pos = 0; | |
298 | for (i = 0; i < table_cnt; i++) { | |
8d605269 | 299 | if (symbol_valid(table[i])) { |
5e5c4fa7 MY |
300 | if (pos != i) |
301 | table[pos] = table[i]; | |
302 | pos++; | |
303 | } else { | |
8d605269 | 304 | free(table[i]); |
5e5c4fa7 MY |
305 | } |
306 | } | |
307 | table_cnt = pos; | |
308 | ||
309 | /* When valid symbol is not registered, exit to error */ | |
310 | if (!table_cnt) { | |
311 | fprintf(stderr, "No valid symbol.\n"); | |
312 | exit(1); | |
313 | } | |
314 | } | |
315 | ||
b3dbb4ec | 316 | static void read_map(FILE *in) |
1da177e4 | 317 | { |
8d605269 MY |
318 | struct sym_entry *sym; |
319 | ||
1da177e4 | 320 | while (!feof(in)) { |
8d605269 MY |
321 | sym = read_symbol(in); |
322 | if (!sym) | |
323 | continue; | |
324 | ||
325 | sym->start_pos = table_cnt; | |
326 | ||
b3dbb4ec PM |
327 | if (table_cnt >= table_size) { |
328 | table_size += 10000; | |
329 | table = realloc(table, sizeof(*table) * table_size); | |
1da177e4 LT |
330 | if (!table) { |
331 | fprintf(stderr, "out of memory\n"); | |
332 | exit (1); | |
333 | } | |
334 | } | |
8d605269 MY |
335 | |
336 | table[table_cnt++] = sym; | |
1da177e4 LT |
337 | } |
338 | } | |
339 | ||
4bfe2b78 | 340 | static void output_label(const char *label) |
1da177e4 | 341 | { |
534c9f2e | 342 | printf(".globl %s\n", label); |
1da177e4 | 343 | printf("\tALGN\n"); |
534c9f2e | 344 | printf("%s:\n", label); |
1da177e4 LT |
345 | } |
346 | ||
fd2ab2f6 MY |
347 | /* Provide proper symbols relocatability by their '_text' relativeness. */ |
348 | static void output_address(unsigned long long addr) | |
349 | { | |
350 | if (_text <= addr) | |
351 | printf("\tPTR\t_text + %#llx\n", addr - _text); | |
352 | else | |
353 | printf("\tPTR\t_text - %#llx\n", _text - addr); | |
354 | } | |
355 | ||
1da177e4 LT |
356 | /* uncompress a compressed symbol. When this function is called, the best table |
357 | * might still be compressed itself, so the function needs to be recursive */ | |
4bfe2b78 | 358 | static int expand_symbol(const unsigned char *data, int len, char *result) |
1da177e4 LT |
359 | { |
360 | int c, rlen, total=0; | |
361 | ||
362 | while (len) { | |
363 | c = *data; | |
364 | /* if the table holds a single char that is the same as the one | |
365 | * we are looking for, then end the search */ | |
366 | if (best_table[c][0]==c && best_table_len[c]==1) { | |
367 | *result++ = c; | |
368 | total++; | |
369 | } else { | |
370 | /* if not, recurse and expand */ | |
371 | rlen = expand_symbol(best_table[c], best_table_len[c], result); | |
372 | total += rlen; | |
373 | result += rlen; | |
374 | } | |
375 | data++; | |
376 | len--; | |
377 | } | |
378 | *result=0; | |
379 | ||
380 | return total; | |
381 | } | |
382 | ||
4bfe2b78 | 383 | static int symbol_absolute(const struct sym_entry *s) |
78eb7159 | 384 | { |
8c996940 | 385 | return s->percpu_absolute; |
78eb7159 KC |
386 | } |
387 | ||
b3dbb4ec | 388 | static void write_src(void) |
1da177e4 | 389 | { |
b3dbb4ec | 390 | unsigned int i, k, off; |
1da177e4 LT |
391 | unsigned int best_idx[256]; |
392 | unsigned int *markers; | |
9281acea | 393 | char buf[KSYM_NAME_LEN]; |
1da177e4 | 394 | |
500193ec | 395 | printf("#include <asm/bitsperlong.h>\n"); |
1da177e4 LT |
396 | printf("#if BITS_PER_LONG == 64\n"); |
397 | printf("#define PTR .quad\n"); | |
72d3ebb9 | 398 | printf("#define ALGN .balign 8\n"); |
1da177e4 LT |
399 | printf("#else\n"); |
400 | printf("#define PTR .long\n"); | |
72d3ebb9 | 401 | printf("#define ALGN .balign 4\n"); |
1da177e4 LT |
402 | printf("#endif\n"); |
403 | ||
aad09470 | 404 | printf("\t.section .rodata, \"a\"\n"); |
1da177e4 | 405 | |
2213e9a6 AB |
406 | if (!base_relative) |
407 | output_label("kallsyms_addresses"); | |
408 | else | |
409 | output_label("kallsyms_offsets"); | |
410 | ||
b3dbb4ec | 411 | for (i = 0; i < table_cnt; i++) { |
2213e9a6 | 412 | if (base_relative) { |
fd2ab2f6 MY |
413 | /* |
414 | * Use the offset relative to the lowest value | |
415 | * encountered of all relative symbols, and emit | |
416 | * non-relocatable fixed offsets that will be fixed | |
417 | * up at runtime. | |
418 | */ | |
419 | ||
2213e9a6 AB |
420 | long long offset; |
421 | int overflow; | |
422 | ||
423 | if (!absolute_percpu) { | |
8d605269 | 424 | offset = table[i]->addr - relative_base; |
2213e9a6 | 425 | overflow = (offset < 0 || offset > UINT_MAX); |
8d605269 MY |
426 | } else if (symbol_absolute(table[i])) { |
427 | offset = table[i]->addr; | |
2213e9a6 AB |
428 | overflow = (offset < 0 || offset > INT_MAX); |
429 | } else { | |
8d605269 | 430 | offset = relative_base - table[i]->addr - 1; |
2213e9a6 AB |
431 | overflow = (offset < INT_MIN || offset >= 0); |
432 | } | |
433 | if (overflow) { | |
434 | fprintf(stderr, "kallsyms failure: " | |
435 | "%s symbol value %#llx out of range in relative mode\n", | |
8d605269 MY |
436 | symbol_absolute(table[i]) ? "absolute" : "relative", |
437 | table[i]->addr); | |
2213e9a6 AB |
438 | exit(EXIT_FAILURE); |
439 | } | |
440 | printf("\t.long\t%#x\n", (int)offset); | |
8d605269 MY |
441 | } else if (!symbol_absolute(table[i])) { |
442 | output_address(table[i]->addr); | |
fd593d12 | 443 | } else { |
8d605269 | 444 | printf("\tPTR\t%#llx\n", table[i]->addr); |
fd593d12 | 445 | } |
1da177e4 LT |
446 | } |
447 | printf("\n"); | |
448 | ||
2213e9a6 AB |
449 | if (base_relative) { |
450 | output_label("kallsyms_relative_base"); | |
fd2ab2f6 | 451 | output_address(relative_base); |
2213e9a6 AB |
452 | printf("\n"); |
453 | } | |
454 | ||
1da177e4 | 455 | output_label("kallsyms_num_syms"); |
80ffbaa5 | 456 | printf("\t.long\t%u\n", table_cnt); |
1da177e4 LT |
457 | printf("\n"); |
458 | ||
459 | /* table of offset markers, that give the offset in the compressed stream | |
460 | * every 256 symbols */ | |
f1a136e0 JJ |
461 | markers = malloc(sizeof(unsigned int) * ((table_cnt + 255) / 256)); |
462 | if (!markers) { | |
463 | fprintf(stderr, "kallsyms failure: " | |
464 | "unable to allocate required memory\n"); | |
465 | exit(EXIT_FAILURE); | |
466 | } | |
1da177e4 LT |
467 | |
468 | output_label("kallsyms_names"); | |
1da177e4 | 469 | off = 0; |
b3dbb4ec PM |
470 | for (i = 0; i < table_cnt; i++) { |
471 | if ((i & 0xFF) == 0) | |
472 | markers[i >> 8] = off; | |
1da177e4 | 473 | |
8d605269 MY |
474 | printf("\t.byte 0x%02x", table[i]->len); |
475 | for (k = 0; k < table[i]->len; k++) | |
476 | printf(", 0x%02x", table[i]->sym[k]); | |
1da177e4 LT |
477 | printf("\n"); |
478 | ||
8d605269 | 479 | off += table[i]->len + 1; |
1da177e4 LT |
480 | } |
481 | printf("\n"); | |
482 | ||
483 | output_label("kallsyms_markers"); | |
b3dbb4ec | 484 | for (i = 0; i < ((table_cnt + 255) >> 8); i++) |
80ffbaa5 | 485 | printf("\t.long\t%u\n", markers[i]); |
1da177e4 LT |
486 | printf("\n"); |
487 | ||
488 | free(markers); | |
489 | ||
490 | output_label("kallsyms_token_table"); | |
491 | off = 0; | |
492 | for (i = 0; i < 256; i++) { | |
493 | best_idx[i] = off; | |
b3dbb4ec | 494 | expand_symbol(best_table[i], best_table_len[i], buf); |
1da177e4 LT |
495 | printf("\t.asciz\t\"%s\"\n", buf); |
496 | off += strlen(buf) + 1; | |
497 | } | |
498 | printf("\n"); | |
499 | ||
500 | output_label("kallsyms_token_index"); | |
501 | for (i = 0; i < 256; i++) | |
502 | printf("\t.short\t%d\n", best_idx[i]); | |
503 | printf("\n"); | |
504 | } | |
505 | ||
506 | ||
507 | /* table lookup compression functions */ | |
508 | ||
1da177e4 | 509 | /* count all the possible tokens in a symbol */ |
4bfe2b78 | 510 | static void learn_symbol(const unsigned char *symbol, int len) |
1da177e4 LT |
511 | { |
512 | int i; | |
513 | ||
514 | for (i = 0; i < len - 1; i++) | |
b3dbb4ec | 515 | token_profit[ symbol[i] + (symbol[i + 1] << 8) ]++; |
1da177e4 LT |
516 | } |
517 | ||
518 | /* decrease the count for all the possible tokens in a symbol */ | |
4bfe2b78 | 519 | static void forget_symbol(const unsigned char *symbol, int len) |
1da177e4 LT |
520 | { |
521 | int i; | |
522 | ||
523 | for (i = 0; i < len - 1; i++) | |
b3dbb4ec | 524 | token_profit[ symbol[i] + (symbol[i + 1] << 8) ]--; |
1da177e4 LT |
525 | } |
526 | ||
5e5c4fa7 | 527 | /* do the initial token count */ |
1da177e4 LT |
528 | static void build_initial_tok_table(void) |
529 | { | |
5e5c4fa7 | 530 | unsigned int i; |
1da177e4 | 531 | |
5e5c4fa7 | 532 | for (i = 0; i < table_cnt; i++) |
8d605269 | 533 | learn_symbol(table[i]->sym, table[i]->len); |
1da177e4 LT |
534 | } |
535 | ||
2558c138 | 536 | static unsigned char *find_token(unsigned char *str, int len, |
4bfe2b78 | 537 | const unsigned char *token) |
7c5d249a PM |
538 | { |
539 | int i; | |
540 | ||
541 | for (i = 0; i < len - 1; i++) { | |
542 | if (str[i] == token[0] && str[i+1] == token[1]) | |
543 | return &str[i]; | |
544 | } | |
545 | return NULL; | |
546 | } | |
547 | ||
1da177e4 LT |
548 | /* replace a given token in all the valid symbols. Use the sampled symbols |
549 | * to update the counts */ | |
4bfe2b78 | 550 | static void compress_symbols(const unsigned char *str, int idx) |
1da177e4 | 551 | { |
b3dbb4ec PM |
552 | unsigned int i, len, size; |
553 | unsigned char *p1, *p2; | |
1da177e4 | 554 | |
b3dbb4ec | 555 | for (i = 0; i < table_cnt; i++) { |
1da177e4 | 556 | |
8d605269 MY |
557 | len = table[i]->len; |
558 | p1 = table[i]->sym; | |
b3dbb4ec PM |
559 | |
560 | /* find the token on the symbol */ | |
7c5d249a | 561 | p2 = find_token(p1, len, str); |
b3dbb4ec PM |
562 | if (!p2) continue; |
563 | ||
564 | /* decrease the counts for this symbol's tokens */ | |
8d605269 | 565 | forget_symbol(table[i]->sym, len); |
b3dbb4ec PM |
566 | |
567 | size = len; | |
1da177e4 LT |
568 | |
569 | do { | |
b3dbb4ec PM |
570 | *p2 = idx; |
571 | p2++; | |
572 | size -= (p2 - p1); | |
573 | memmove(p2, p2 + 1, size); | |
574 | p1 = p2; | |
575 | len--; | |
576 | ||
577 | if (size < 2) break; | |
578 | ||
1da177e4 | 579 | /* find the token on the symbol */ |
7c5d249a | 580 | p2 = find_token(p1, size, str); |
1da177e4 | 581 | |
b3dbb4ec | 582 | } while (p2); |
1da177e4 | 583 | |
8d605269 | 584 | table[i]->len = len; |
1da177e4 | 585 | |
b3dbb4ec | 586 | /* increase the counts for this symbol's new tokens */ |
8d605269 | 587 | learn_symbol(table[i]->sym, len); |
1da177e4 LT |
588 | } |
589 | } | |
590 | ||
591 | /* search the token with the maximum profit */ | |
b3dbb4ec | 592 | static int find_best_token(void) |
1da177e4 | 593 | { |
b3dbb4ec | 594 | int i, best, bestprofit; |
1da177e4 LT |
595 | |
596 | bestprofit=-10000; | |
b3dbb4ec | 597 | best = 0; |
1da177e4 | 598 | |
b3dbb4ec PM |
599 | for (i = 0; i < 0x10000; i++) { |
600 | if (token_profit[i] > bestprofit) { | |
601 | best = i; | |
602 | bestprofit = token_profit[i]; | |
1da177e4 | 603 | } |
1da177e4 | 604 | } |
1da177e4 LT |
605 | return best; |
606 | } | |
607 | ||
608 | /* this is the core of the algorithm: calculate the "best" table */ | |
609 | static void optimize_result(void) | |
610 | { | |
b3dbb4ec | 611 | int i, best; |
1da177e4 LT |
612 | |
613 | /* using the '\0' symbol last allows compress_symbols to use standard | |
614 | * fast string functions */ | |
615 | for (i = 255; i >= 0; i--) { | |
616 | ||
617 | /* if this table slot is empty (it is not used by an actual | |
618 | * original char code */ | |
619 | if (!best_table_len[i]) { | |
620 | ||
cbf7a90e | 621 | /* find the token with the best profit value */ |
1da177e4 | 622 | best = find_best_token(); |
e0a04b11 XW |
623 | if (token_profit[best] == 0) |
624 | break; | |
1da177e4 LT |
625 | |
626 | /* place it in the "best" table */ | |
b3dbb4ec PM |
627 | best_table_len[i] = 2; |
628 | best_table[i][0] = best & 0xFF; | |
629 | best_table[i][1] = (best >> 8) & 0xFF; | |
1da177e4 LT |
630 | |
631 | /* replace this token in all the valid symbols */ | |
b3dbb4ec | 632 | compress_symbols(best_table[i], i); |
1da177e4 LT |
633 | } |
634 | } | |
635 | } | |
636 | ||
637 | /* start by placing the symbols that are actually used on the table */ | |
638 | static void insert_real_symbols_in_table(void) | |
639 | { | |
b3dbb4ec | 640 | unsigned int i, j, c; |
1da177e4 | 641 | |
b3dbb4ec | 642 | for (i = 0; i < table_cnt; i++) { |
8d605269 MY |
643 | for (j = 0; j < table[i]->len; j++) { |
644 | c = table[i]->sym[j]; | |
b3dbb4ec PM |
645 | best_table[c][0]=c; |
646 | best_table_len[c]=1; | |
1da177e4 LT |
647 | } |
648 | } | |
649 | } | |
650 | ||
651 | static void optimize_token_table(void) | |
652 | { | |
1da177e4 LT |
653 | build_initial_tok_table(); |
654 | ||
655 | insert_real_symbols_in_table(); | |
656 | ||
657 | optimize_result(); | |
658 | } | |
659 | ||
b478b782 LJ |
660 | /* guess for "linker script provide" symbol */ |
661 | static int may_be_linker_script_provide_symbol(const struct sym_entry *se) | |
662 | { | |
29e55ad3 | 663 | const char *symbol = sym_name(se); |
b478b782 LJ |
664 | int len = se->len - 1; |
665 | ||
666 | if (len < 8) | |
667 | return 0; | |
668 | ||
669 | if (symbol[0] != '_' || symbol[1] != '_') | |
670 | return 0; | |
671 | ||
672 | /* __start_XXXXX */ | |
673 | if (!memcmp(symbol + 2, "start_", 6)) | |
674 | return 1; | |
675 | ||
676 | /* __stop_XXXXX */ | |
677 | if (!memcmp(symbol + 2, "stop_", 5)) | |
678 | return 1; | |
679 | ||
680 | /* __end_XXXXX */ | |
681 | if (!memcmp(symbol + 2, "end_", 4)) | |
682 | return 1; | |
683 | ||
684 | /* __XXXXX_start */ | |
685 | if (!memcmp(symbol + len - 6, "_start", 6)) | |
686 | return 1; | |
687 | ||
688 | /* __XXXXX_end */ | |
689 | if (!memcmp(symbol + len - 4, "_end", 4)) | |
690 | return 1; | |
691 | ||
692 | return 0; | |
693 | } | |
694 | ||
f2df3f65 PM |
695 | static int compare_symbols(const void *a, const void *b) |
696 | { | |
8d605269 MY |
697 | const struct sym_entry *sa = *(const struct sym_entry **)a; |
698 | const struct sym_entry *sb = *(const struct sym_entry **)b; | |
f2df3f65 PM |
699 | int wa, wb; |
700 | ||
f2df3f65 PM |
701 | /* sort by address first */ |
702 | if (sa->addr > sb->addr) | |
703 | return 1; | |
704 | if (sa->addr < sb->addr) | |
705 | return -1; | |
706 | ||
707 | /* sort by "weakness" type */ | |
708 | wa = (sa->sym[0] == 'w') || (sa->sym[0] == 'W'); | |
709 | wb = (sb->sym[0] == 'w') || (sb->sym[0] == 'W'); | |
710 | if (wa != wb) | |
711 | return wa - wb; | |
712 | ||
b478b782 LJ |
713 | /* sort by "linker script provide" type */ |
714 | wa = may_be_linker_script_provide_symbol(sa); | |
715 | wb = may_be_linker_script_provide_symbol(sb); | |
716 | if (wa != wb) | |
717 | return wa - wb; | |
718 | ||
719 | /* sort by the number of prefix underscores */ | |
aa915245 MY |
720 | wa = strspn(sym_name(sa), "_"); |
721 | wb = strspn(sym_name(sb), "_"); | |
b478b782 LJ |
722 | if (wa != wb) |
723 | return wa - wb; | |
724 | ||
f2df3f65 PM |
725 | /* sort by initial order, so that other symbols are left undisturbed */ |
726 | return sa->start_pos - sb->start_pos; | |
727 | } | |
728 | ||
729 | static void sort_symbols(void) | |
730 | { | |
8d605269 | 731 | qsort(table, table_cnt, sizeof(table[0]), compare_symbols); |
f2df3f65 | 732 | } |
1da177e4 | 733 | |
c6bda7c9 RR |
734 | static void make_percpus_absolute(void) |
735 | { | |
736 | unsigned int i; | |
737 | ||
738 | for (i = 0; i < table_cnt; i++) | |
8d605269 | 739 | if (symbol_in_range(table[i], &percpu_range, 1)) { |
8c996940 AB |
740 | /* |
741 | * Keep the 'A' override for percpu symbols to | |
742 | * ensure consistent behavior compared to older | |
743 | * versions of this tool. | |
744 | */ | |
8d605269 MY |
745 | table[i]->sym[0] = 'A'; |
746 | table[i]->percpu_absolute = 1; | |
8c996940 | 747 | } |
c6bda7c9 RR |
748 | } |
749 | ||
2213e9a6 AB |
750 | /* find the minimum non-absolute symbol address */ |
751 | static void record_relative_base(void) | |
752 | { | |
753 | unsigned int i; | |
754 | ||
2213e9a6 | 755 | for (i = 0; i < table_cnt; i++) |
8d605269 | 756 | if (!symbol_absolute(table[i])) { |
f34ea029 MY |
757 | /* |
758 | * The table is sorted by address. | |
759 | * Take the first non-absolute symbol value. | |
760 | */ | |
8d605269 | 761 | relative_base = table[i]->addr; |
f34ea029 MY |
762 | return; |
763 | } | |
2213e9a6 AB |
764 | } |
765 | ||
b3dbb4ec | 766 | int main(int argc, char **argv) |
1da177e4 | 767 | { |
41f11a4f YS |
768 | if (argc >= 2) { |
769 | int i; | |
770 | for (i = 1; i < argc; i++) { | |
771 | if(strcmp(argv[i], "--all-symbols") == 0) | |
772 | all_symbols = 1; | |
c6bda7c9 RR |
773 | else if (strcmp(argv[i], "--absolute-percpu") == 0) |
774 | absolute_percpu = 1; | |
534c9f2e | 775 | else if (strcmp(argv[i], "--base-relative") == 0) |
2213e9a6 AB |
776 | base_relative = 1; |
777 | else | |
41f11a4f YS |
778 | usage(); |
779 | } | |
780 | } else if (argc != 1) | |
1da177e4 LT |
781 | usage(); |
782 | ||
783 | read_map(stdin); | |
5e5c4fa7 | 784 | shrink_table(); |
c6bda7c9 RR |
785 | if (absolute_percpu) |
786 | make_percpus_absolute(); | |
f34ea029 | 787 | sort_symbols(); |
2213e9a6 AB |
788 | if (base_relative) |
789 | record_relative_base(); | |
2ea03891 | 790 | optimize_token_table(); |
1da177e4 LT |
791 | write_src(); |
792 | ||
793 | return 0; | |
794 | } |