1 /* Generate assembler source containing symbol 1 /* Generate assembler source containing symbol information
2 * 2 *
3 * Copyright 2002 by Kai Germaschewski 3 * Copyright 2002 by Kai Germaschewski
4 * 4 *
5 * This software may be used and distributed a 5 * This software may be used and distributed according to the terms
6 * of the GNU General Public License, incorpor 6 * of the GNU General Public License, incorporated herein by reference.
7 * 7 *
8 * Usage: kallsyms [--all-symbols] [--absolute 8 * Usage: kallsyms [--all-symbols] [--absolute-percpu] in.map > out.S
9 * 9 *
10 * Table compression uses all the unused 10 * Table compression uses all the unused char codes on the symbols and
11 * maps these to the most used substrings (to 11 * maps these to the most used substrings (tokens). For instance, it might
12 * map char code 0xF7 to represent "write_" a 12 * map char code 0xF7 to represent "write_" and then in every symbol where
13 * "write_" appears it can be replaced by 0xF 13 * "write_" appears it can be replaced by 0xF7, saving 5 bytes.
14 * The used codes themselves are also pla 14 * The used codes themselves are also placed in the table so that the
15 * decompresion can work without "special cas 15 * decompresion can work without "special cases".
16 * Applied to kernel symbols, this usuall 16 * Applied to kernel symbols, this usually produces a compression ratio
17 * of about 50%. 17 * of about 50%.
18 * 18 *
19 */ 19 */
20 20
21 #include <errno.h> 21 #include <errno.h>
22 #include <getopt.h> 22 #include <getopt.h>
23 #include <stdbool.h> 23 #include <stdbool.h>
24 #include <stdio.h> 24 #include <stdio.h>
25 #include <stdlib.h> 25 #include <stdlib.h>
26 #include <string.h> 26 #include <string.h>
27 #include <ctype.h> 27 #include <ctype.h>
28 #include <limits.h> 28 #include <limits.h>
29 29
30 #include <xalloc.h> 30 #include <xalloc.h>
31 31
32 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof( 32 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
33 33
34 #define KSYM_NAME_LEN 512 34 #define KSYM_NAME_LEN 512
35 35
36 struct sym_entry { 36 struct sym_entry {
37 unsigned long long addr; 37 unsigned long long addr;
38 unsigned int len; 38 unsigned int len;
39 unsigned int seq; 39 unsigned int seq;
40 bool percpu_absolute; 40 bool percpu_absolute;
41 unsigned char sym[]; 41 unsigned char sym[];
42 }; 42 };
43 43
44 struct addr_range { 44 struct addr_range {
45 const char *start_sym, *end_sym; 45 const char *start_sym, *end_sym;
46 unsigned long long start, end; 46 unsigned long long start, end;
47 }; 47 };
48 48
49 static unsigned long long _text; 49 static unsigned long long _text;
50 static unsigned long long relative_base; 50 static unsigned long long relative_base;
51 static struct addr_range text_ranges[] = { 51 static struct addr_range text_ranges[] = {
52 { "_stext", "_etext" }, 52 { "_stext", "_etext" },
53 { "_sinittext", "_einittext" }, 53 { "_sinittext", "_einittext" },
54 }; 54 };
55 #define text_range_text (&text_ranges[0]) 55 #define text_range_text (&text_ranges[0])
56 #define text_range_inittext (&text_ranges[1]) 56 #define text_range_inittext (&text_ranges[1])
57 57
58 static struct addr_range percpu_range = { 58 static struct addr_range percpu_range = {
59 "__per_cpu_start", "__per_cpu_end", -1 59 "__per_cpu_start", "__per_cpu_end", -1ULL, 0
60 }; 60 };
61 61
62 static struct sym_entry **table; 62 static struct sym_entry **table;
63 static unsigned int table_size, table_cnt; 63 static unsigned int table_size, table_cnt;
64 static int all_symbols; 64 static int all_symbols;
65 static int absolute_percpu; 65 static int absolute_percpu;
66 66
67 static int token_profit[0x10000]; 67 static int token_profit[0x10000];
68 68
69 /* the table that holds the result of the comp 69 /* the table that holds the result of the compression */
70 static unsigned char best_table[256][2]; 70 static unsigned char best_table[256][2];
71 static unsigned char best_table_len[256]; 71 static unsigned char best_table_len[256];
72 72
73 73
74 static void usage(void) 74 static void usage(void)
75 { 75 {
76 fprintf(stderr, "Usage: kallsyms [--al 76 fprintf(stderr, "Usage: kallsyms [--all-symbols] [--absolute-percpu] in.map > out.S\n");
77 exit(1); 77 exit(1);
78 } 78 }
79 79
80 static char *sym_name(const struct sym_entry * 80 static char *sym_name(const struct sym_entry *s)
81 { 81 {
82 return (char *)s->sym + 1; 82 return (char *)s->sym + 1;
83 } 83 }
84 84
85 static bool is_ignored_symbol(const char *name 85 static bool is_ignored_symbol(const char *name, char type)
86 { 86 {
87 if (type == 'u' || type == 'n') 87 if (type == 'u' || type == 'n')
88 return true; 88 return true;
89 89
90 if (toupper(type) == 'A') { 90 if (toupper(type) == 'A') {
91 /* Keep these useful absolute 91 /* Keep these useful absolute symbols */
92 if (strcmp(name, "__kernel_sys 92 if (strcmp(name, "__kernel_syscall_via_break") &&
93 strcmp(name, "__kernel_sys 93 strcmp(name, "__kernel_syscall_via_epc") &&
94 strcmp(name, "__kernel_sig 94 strcmp(name, "__kernel_sigtramp") &&
95 strcmp(name, "__gp")) 95 strcmp(name, "__gp"))
96 return true; 96 return true;
97 } 97 }
98 98
99 return false; 99 return false;
100 } 100 }
101 101
102 static void check_symbol_range(const char *sym 102 static void check_symbol_range(const char *sym, unsigned long long addr,
103 struct addr_ran 103 struct addr_range *ranges, int entries)
104 { 104 {
105 size_t i; 105 size_t i;
106 struct addr_range *ar; 106 struct addr_range *ar;
107 107
108 for (i = 0; i < entries; ++i) { 108 for (i = 0; i < entries; ++i) {
109 ar = &ranges[i]; 109 ar = &ranges[i];
110 110
111 if (strcmp(sym, ar->start_sym) 111 if (strcmp(sym, ar->start_sym) == 0) {
112 ar->start = addr; 112 ar->start = addr;
113 return; 113 return;
114 } else if (strcmp(sym, ar->end 114 } else if (strcmp(sym, ar->end_sym) == 0) {
115 ar->end = addr; 115 ar->end = addr;
116 return; 116 return;
117 } 117 }
118 } 118 }
119 } 119 }
120 120
121 static struct sym_entry *read_symbol(FILE *in, 121 static struct sym_entry *read_symbol(FILE *in, char **buf, size_t *buf_len)
122 { 122 {
123 char *name, type, *p; 123 char *name, type, *p;
124 unsigned long long addr; 124 unsigned long long addr;
125 size_t len; 125 size_t len;
126 ssize_t readlen; 126 ssize_t readlen;
127 struct sym_entry *sym; 127 struct sym_entry *sym;
128 128
129 errno = 0; 129 errno = 0;
130 readlen = getline(buf, buf_len, in); 130 readlen = getline(buf, buf_len, in);
131 if (readlen < 0) { 131 if (readlen < 0) {
132 if (errno) { 132 if (errno) {
133 perror("read_symbol"); 133 perror("read_symbol");
134 exit(EXIT_FAILURE); 134 exit(EXIT_FAILURE);
135 } 135 }
136 return NULL; 136 return NULL;
137 } 137 }
138 138
139 if ((*buf)[readlen - 1] == '\n') 139 if ((*buf)[readlen - 1] == '\n')
140 (*buf)[readlen - 1] = 0; 140 (*buf)[readlen - 1] = 0;
141 141
142 addr = strtoull(*buf, &p, 16); 142 addr = strtoull(*buf, &p, 16);
143 143
144 if (*buf == p || *p++ != ' ' || !isasc 144 if (*buf == p || *p++ != ' ' || !isascii((type = *p++)) || *p++ != ' ') {
145 fprintf(stderr, "line format e 145 fprintf(stderr, "line format error\n");
146 exit(EXIT_FAILURE); 146 exit(EXIT_FAILURE);
147 } 147 }
148 148
149 name = p; 149 name = p;
150 len = strlen(name); 150 len = strlen(name);
151 151
152 if (len >= KSYM_NAME_LEN) { 152 if (len >= KSYM_NAME_LEN) {
153 fprintf(stderr, "Symbol %s too 153 fprintf(stderr, "Symbol %s too long for kallsyms (%zu >= %d).\n"
154 "Please increa 154 "Please increase KSYM_NAME_LEN both in kernel and kallsyms.c\n",
155 name, len, KSYM_NAME_L 155 name, len, KSYM_NAME_LEN);
156 return NULL; 156 return NULL;
157 } 157 }
158 158
159 if (strcmp(name, "_text") == 0) 159 if (strcmp(name, "_text") == 0)
160 _text = addr; 160 _text = addr;
161 161
162 /* Ignore most absolute/undefined (?) 162 /* Ignore most absolute/undefined (?) symbols. */
163 if (is_ignored_symbol(name, type)) 163 if (is_ignored_symbol(name, type))
164 return NULL; 164 return NULL;
165 165
166 check_symbol_range(name, addr, text_ra 166 check_symbol_range(name, addr, text_ranges, ARRAY_SIZE(text_ranges));
167 check_symbol_range(name, addr, &percpu 167 check_symbol_range(name, addr, &percpu_range, 1);
168 168
169 /* include the type field in the symbo 169 /* include the type field in the symbol name, so that it gets
170 * compressed together */ 170 * compressed together */
171 len++; 171 len++;
172 172
173 sym = xmalloc(sizeof(*sym) + len + 1); 173 sym = xmalloc(sizeof(*sym) + len + 1);
174 sym->addr = addr; 174 sym->addr = addr;
175 sym->len = len; 175 sym->len = len;
176 sym->sym[0] = type; 176 sym->sym[0] = type;
177 strcpy(sym_name(sym), name); 177 strcpy(sym_name(sym), name);
178 sym->percpu_absolute = false; 178 sym->percpu_absolute = false;
179 179
180 return sym; 180 return sym;
181 } 181 }
182 182
183 static int symbol_in_range(const struct sym_en 183 static int symbol_in_range(const struct sym_entry *s,
184 const struct addr_r 184 const struct addr_range *ranges, int entries)
185 { 185 {
186 size_t i; 186 size_t i;
187 const struct addr_range *ar; 187 const struct addr_range *ar;
188 188
189 for (i = 0; i < entries; ++i) { 189 for (i = 0; i < entries; ++i) {
190 ar = &ranges[i]; 190 ar = &ranges[i];
191 191
192 if (s->addr >= ar->start && s- 192 if (s->addr >= ar->start && s->addr <= ar->end)
193 return 1; 193 return 1;
194 } 194 }
195 195
196 return 0; 196 return 0;
197 } 197 }
198 198
199 static bool string_starts_with(const char *s, 199 static bool string_starts_with(const char *s, const char *prefix)
200 { 200 {
201 return strncmp(s, prefix, strlen(prefi 201 return strncmp(s, prefix, strlen(prefix)) == 0;
202 } 202 }
203 203
204 static int symbol_valid(const struct sym_entry 204 static int symbol_valid(const struct sym_entry *s)
205 { 205 {
206 const char *name = sym_name(s); 206 const char *name = sym_name(s);
207 207
208 /* if --all-symbols is not specified, 208 /* if --all-symbols is not specified, then symbols outside the text
209 * and inittext sections are discarded 209 * and inittext sections are discarded */
210 if (!all_symbols) { 210 if (!all_symbols) {
211 /* 211 /*
212 * Symbols starting with __sta 212 * Symbols starting with __start and __stop are used to denote
213 * section boundaries, and sho 213 * section boundaries, and should always be included:
214 */ 214 */
215 if (string_starts_with(name, " 215 if (string_starts_with(name, "__start_") ||
216 string_starts_with(name, " 216 string_starts_with(name, "__stop_"))
217 return 1; 217 return 1;
218 218
219 if (symbol_in_range(s, text_ra 219 if (symbol_in_range(s, text_ranges,
220 ARRAY_SIZE 220 ARRAY_SIZE(text_ranges)) == 0)
221 return 0; 221 return 0;
222 /* Corner case. Discard any s 222 /* Corner case. Discard any symbols with the same value as
223 * _etext _einittext; they can 223 * _etext _einittext; they can move between pass 1 and 2 when
224 * the kallsyms data are added 224 * the kallsyms data are added. If these symbols move then
225 * they may get dropped in pas 225 * they may get dropped in pass 2, which breaks the kallsyms
226 * rules. 226 * rules.
227 */ 227 */
228 if ((s->addr == text_range_tex 228 if ((s->addr == text_range_text->end &&
229 strcmp(name, text_range_t 229 strcmp(name, text_range_text->end_sym)) ||
230 (s->addr == text_range_ini 230 (s->addr == text_range_inittext->end &&
231 strcmp(name, text_range_i 231 strcmp(name, text_range_inittext->end_sym)))
232 return 0; 232 return 0;
233 } 233 }
234 234
235 return 1; 235 return 1;
236 } 236 }
237 237
238 /* remove all the invalid symbols from the tab 238 /* remove all the invalid symbols from the table */
239 static void shrink_table(void) 239 static void shrink_table(void)
240 { 240 {
241 unsigned int i, pos; 241 unsigned int i, pos;
242 242
243 pos = 0; 243 pos = 0;
244 for (i = 0; i < table_cnt; i++) { 244 for (i = 0; i < table_cnt; i++) {
245 if (symbol_valid(table[i])) { 245 if (symbol_valid(table[i])) {
246 if (pos != i) 246 if (pos != i)
247 table[pos] = t 247 table[pos] = table[i];
248 pos++; 248 pos++;
249 } else { 249 } else {
250 free(table[i]); 250 free(table[i]);
251 } 251 }
252 } 252 }
253 table_cnt = pos; 253 table_cnt = pos;
254 } 254 }
255 255
256 static void read_map(const char *in) 256 static void read_map(const char *in)
257 { 257 {
258 FILE *fp; 258 FILE *fp;
259 struct sym_entry *sym; 259 struct sym_entry *sym;
260 char *buf = NULL; 260 char *buf = NULL;
261 size_t buflen = 0; 261 size_t buflen = 0;
262 262
263 fp = fopen(in, "r"); 263 fp = fopen(in, "r");
264 if (!fp) { 264 if (!fp) {
265 perror(in); 265 perror(in);
266 exit(1); 266 exit(1);
267 } 267 }
268 268
269 while (!feof(fp)) { 269 while (!feof(fp)) {
270 sym = read_symbol(fp, &buf, &b 270 sym = read_symbol(fp, &buf, &buflen);
271 if (!sym) 271 if (!sym)
272 continue; 272 continue;
273 273
274 sym->seq = table_cnt; 274 sym->seq = table_cnt;
275 275
276 if (table_cnt >= table_size) { 276 if (table_cnt >= table_size) {
277 table_size += 10000; 277 table_size += 10000;
278 table = xrealloc(table 278 table = xrealloc(table, sizeof(*table) * table_size);
279 } 279 }
280 280
281 table[table_cnt++] = sym; 281 table[table_cnt++] = sym;
282 } 282 }
283 283
284 free(buf); 284 free(buf);
285 fclose(fp); 285 fclose(fp);
286 } 286 }
287 287
288 static void output_label(const char *label) 288 static void output_label(const char *label)
289 { 289 {
290 printf(".globl %s\n", label); 290 printf(".globl %s\n", label);
291 printf("\tALGN\n"); 291 printf("\tALGN\n");
292 printf("%s:\n", label); 292 printf("%s:\n", label);
293 } 293 }
294 294
295 /* uncompress a compressed symbol. When this f 295 /* uncompress a compressed symbol. When this function is called, the best table
296 * might still be compressed itself, so the fu 296 * might still be compressed itself, so the function needs to be recursive */
297 static int expand_symbol(const unsigned char * 297 static int expand_symbol(const unsigned char *data, int len, char *result)
298 { 298 {
299 int c, rlen, total=0; 299 int c, rlen, total=0;
300 300
301 while (len) { 301 while (len) {
302 c = *data; 302 c = *data;
303 /* if the table holds a single 303 /* if the table holds a single char that is the same as the one
304 * we are looking for, then en 304 * we are looking for, then end the search */
305 if (best_table[c][0]==c && bes 305 if (best_table[c][0]==c && best_table_len[c]==1) {
306 *result++ = c; 306 *result++ = c;
307 total++; 307 total++;
308 } else { 308 } else {
309 /* if not, recurse and 309 /* if not, recurse and expand */
310 rlen = expand_symbol(b 310 rlen = expand_symbol(best_table[c], best_table_len[c], result);
311 total += rlen; 311 total += rlen;
312 result += rlen; 312 result += rlen;
313 } 313 }
314 data++; 314 data++;
315 len--; 315 len--;
316 } 316 }
317 *result=0; 317 *result=0;
318 318
319 return total; 319 return total;
320 } 320 }
321 321
322 static bool symbol_absolute(const struct sym_e 322 static bool symbol_absolute(const struct sym_entry *s)
323 { 323 {
324 return s->percpu_absolute; 324 return s->percpu_absolute;
325 } 325 }
326 326
327 static int compare_names(const void *a, const 327 static int compare_names(const void *a, const void *b)
328 { 328 {
329 int ret; 329 int ret;
330 const struct sym_entry *sa = *(const s 330 const struct sym_entry *sa = *(const struct sym_entry **)a;
331 const struct sym_entry *sb = *(const s 331 const struct sym_entry *sb = *(const struct sym_entry **)b;
332 332
333 ret = strcmp(sym_name(sa), sym_name(sb 333 ret = strcmp(sym_name(sa), sym_name(sb));
334 if (!ret) { 334 if (!ret) {
335 if (sa->addr > sb->addr) 335 if (sa->addr > sb->addr)
336 return 1; 336 return 1;
337 else if (sa->addr < sb->addr) 337 else if (sa->addr < sb->addr)
338 return -1; 338 return -1;
339 339
340 /* keep old order */ 340 /* keep old order */
341 return (int)(sa->seq - sb->seq 341 return (int)(sa->seq - sb->seq);
342 } 342 }
343 343
344 return ret; 344 return ret;
345 } 345 }
346 346
347 static void sort_symbols_by_name(void) 347 static void sort_symbols_by_name(void)
348 { 348 {
349 qsort(table, table_cnt, sizeof(table[0 349 qsort(table, table_cnt, sizeof(table[0]), compare_names);
350 } 350 }
351 351
352 static void write_src(void) 352 static void write_src(void)
353 { 353 {
354 unsigned int i, k, off; 354 unsigned int i, k, off;
355 unsigned int best_idx[256]; 355 unsigned int best_idx[256];
356 unsigned int *markers, markers_cnt; 356 unsigned int *markers, markers_cnt;
357 char buf[KSYM_NAME_LEN]; 357 char buf[KSYM_NAME_LEN];
358 358
359 printf("#include <asm/bitsperlong.h>\n 359 printf("#include <asm/bitsperlong.h>\n");
360 printf("#if BITS_PER_LONG == 64\n"); 360 printf("#if BITS_PER_LONG == 64\n");
361 printf("#define PTR .quad\n"); 361 printf("#define PTR .quad\n");
362 printf("#define ALGN .balign 8\n"); 362 printf("#define ALGN .balign 8\n");
363 printf("#else\n"); 363 printf("#else\n");
364 printf("#define PTR .long\n"); 364 printf("#define PTR .long\n");
365 printf("#define ALGN .balign 4\n"); 365 printf("#define ALGN .balign 4\n");
366 printf("#endif\n"); 366 printf("#endif\n");
367 367
368 printf("\t.section .rodata, \"a\"\n"); 368 printf("\t.section .rodata, \"a\"\n");
369 369
370 output_label("kallsyms_num_syms"); 370 output_label("kallsyms_num_syms");
371 printf("\t.long\t%u\n", table_cnt); 371 printf("\t.long\t%u\n", table_cnt);
372 printf("\n"); 372 printf("\n");
373 373
374 /* table of offset markers, that give 374 /* table of offset markers, that give the offset in the compressed stream
375 * every 256 symbols */ 375 * every 256 symbols */
376 markers_cnt = (table_cnt + 255) / 256; 376 markers_cnt = (table_cnt + 255) / 256;
377 markers = xmalloc(sizeof(*markers) * m 377 markers = xmalloc(sizeof(*markers) * markers_cnt);
378 378
379 output_label("kallsyms_names"); 379 output_label("kallsyms_names");
380 off = 0; 380 off = 0;
381 for (i = 0; i < table_cnt; i++) { 381 for (i = 0; i < table_cnt; i++) {
382 if ((i & 0xFF) == 0) 382 if ((i & 0xFF) == 0)
383 markers[i >> 8] = off; 383 markers[i >> 8] = off;
384 table[i]->seq = i; 384 table[i]->seq = i;
385 385
386 /* There cannot be any symbol 386 /* There cannot be any symbol of length zero. */
387 if (table[i]->len == 0) { 387 if (table[i]->len == 0) {
388 fprintf(stderr, "kalls 388 fprintf(stderr, "kallsyms failure: "
389 "unexpected ze 389 "unexpected zero symbol length\n");
390 exit(EXIT_FAILURE); 390 exit(EXIT_FAILURE);
391 } 391 }
392 392
393 /* Only lengths that fit in up 393 /* Only lengths that fit in up-to-two-byte ULEB128 are supported. */
394 if (table[i]->len > 0x3FFF) { 394 if (table[i]->len > 0x3FFF) {
395 fprintf(stderr, "kalls 395 fprintf(stderr, "kallsyms failure: "
396 "unexpected hu 396 "unexpected huge symbol length\n");
397 exit(EXIT_FAILURE); 397 exit(EXIT_FAILURE);
398 } 398 }
399 399
400 /* Encode length with ULEB128. 400 /* Encode length with ULEB128. */
401 if (table[i]->len <= 0x7F) { 401 if (table[i]->len <= 0x7F) {
402 /* Most symbols use a 402 /* Most symbols use a single byte for the length. */
403 printf("\t.byte 0x%02x 403 printf("\t.byte 0x%02x", table[i]->len);
404 off += table[i]->len + 404 off += table[i]->len + 1;
405 } else { 405 } else {
406 /* "Big" symbols use t 406 /* "Big" symbols use two bytes. */
407 printf("\t.byte 0x%02x 407 printf("\t.byte 0x%02x, 0x%02x",
408 (table[i]->len 408 (table[i]->len & 0x7F) | 0x80,
409 (table[i]->len 409 (table[i]->len >> 7) & 0x7F);
410 off += table[i]->len + 410 off += table[i]->len + 2;
411 } 411 }
412 for (k = 0; k < table[i]->len; 412 for (k = 0; k < table[i]->len; k++)
413 printf(", 0x%02x", tab 413 printf(", 0x%02x", table[i]->sym[k]);
414 414
415 /* 415 /*
416 * Now that we wrote out the c 416 * Now that we wrote out the compressed symbol name, restore the
417 * original name and print it 417 * original name and print it in the comment.
418 */ 418 */
419 expand_symbol(table[i]->sym, t 419 expand_symbol(table[i]->sym, table[i]->len, buf);
420 strcpy((char *)table[i]->sym, 420 strcpy((char *)table[i]->sym, buf);
421 printf("\t/* %s */\n", table[i 421 printf("\t/* %s */\n", table[i]->sym);
422 } 422 }
423 printf("\n"); 423 printf("\n");
424 424
425 output_label("kallsyms_markers"); 425 output_label("kallsyms_markers");
426 for (i = 0; i < markers_cnt; i++) 426 for (i = 0; i < markers_cnt; i++)
427 printf("\t.long\t%u\n", marker 427 printf("\t.long\t%u\n", markers[i]);
428 printf("\n"); 428 printf("\n");
429 429
430 free(markers); 430 free(markers);
431 431
432 output_label("kallsyms_token_table"); 432 output_label("kallsyms_token_table");
433 off = 0; 433 off = 0;
434 for (i = 0; i < 256; i++) { 434 for (i = 0; i < 256; i++) {
435 best_idx[i] = off; 435 best_idx[i] = off;
436 expand_symbol(best_table[i], b 436 expand_symbol(best_table[i], best_table_len[i], buf);
437 printf("\t.asciz\t\"%s\"\n", b 437 printf("\t.asciz\t\"%s\"\n", buf);
438 off += strlen(buf) + 1; 438 off += strlen(buf) + 1;
439 } 439 }
440 printf("\n"); 440 printf("\n");
441 441
442 output_label("kallsyms_token_index"); 442 output_label("kallsyms_token_index");
443 for (i = 0; i < 256; i++) 443 for (i = 0; i < 256; i++)
444 printf("\t.short\t%d\n", best_ 444 printf("\t.short\t%d\n", best_idx[i]);
445 printf("\n"); 445 printf("\n");
446 446
447 output_label("kallsyms_offsets"); 447 output_label("kallsyms_offsets");
448 448
449 for (i = 0; i < table_cnt; i++) { 449 for (i = 0; i < table_cnt; i++) {
450 /* 450 /*
451 * Use the offset relative to 451 * Use the offset relative to the lowest value
452 * encountered of all relative 452 * encountered of all relative symbols, and emit
453 * non-relocatable fixed offse 453 * non-relocatable fixed offsets that will be fixed
454 * up at runtime. 454 * up at runtime.
455 */ 455 */
456 456
457 long long offset; 457 long long offset;
458 bool overflow; 458 bool overflow;
459 459
460 if (!absolute_percpu) { 460 if (!absolute_percpu) {
461 offset = table[i]->add 461 offset = table[i]->addr - relative_base;
462 overflow = offset < 0 462 overflow = offset < 0 || offset > UINT_MAX;
463 } else if (symbol_absolute(tab 463 } else if (symbol_absolute(table[i])) {
464 offset = table[i]->add 464 offset = table[i]->addr;
465 overflow = offset < 0 465 overflow = offset < 0 || offset > INT_MAX;
466 } else { 466 } else {
467 offset = relative_base 467 offset = relative_base - table[i]->addr - 1;
468 overflow = offset < IN 468 overflow = offset < INT_MIN || offset >= 0;
469 } 469 }
470 if (overflow) { 470 if (overflow) {
471 fprintf(stderr, "kalls 471 fprintf(stderr, "kallsyms failure: "
472 "%s symbol val 472 "%s symbol value %#llx out of range in relative mode\n",
473 symbol_absolut 473 symbol_absolute(table[i]) ? "absolute" : "relative",
474 table[i]->addr 474 table[i]->addr);
475 exit(EXIT_FAILURE); 475 exit(EXIT_FAILURE);
476 } 476 }
477 printf("\t.long\t%#x\t/* %s */ 477 printf("\t.long\t%#x\t/* %s */\n", (int)offset, table[i]->sym);
478 } 478 }
479 printf("\n"); 479 printf("\n");
480 480
481 output_label("kallsyms_relative_base") 481 output_label("kallsyms_relative_base");
482 /* Provide proper symbols relocatabili 482 /* Provide proper symbols relocatability by their '_text' relativeness. */
483 if (_text <= relative_base) 483 if (_text <= relative_base)
484 printf("\tPTR\t_text + %#llx\n 484 printf("\tPTR\t_text + %#llx\n", relative_base - _text);
485 else 485 else
486 printf("\tPTR\t_text - %#llx\n 486 printf("\tPTR\t_text - %#llx\n", _text - relative_base);
487 printf("\n"); 487 printf("\n");
488 488
489 sort_symbols_by_name(); 489 sort_symbols_by_name();
490 output_label("kallsyms_seqs_of_names") 490 output_label("kallsyms_seqs_of_names");
491 for (i = 0; i < table_cnt; i++) 491 for (i = 0; i < table_cnt; i++)
492 printf("\t.byte 0x%02x, 0x%02x 492 printf("\t.byte 0x%02x, 0x%02x, 0x%02x\t/* %s */\n",
493 (unsigned char)(table[ 493 (unsigned char)(table[i]->seq >> 16),
494 (unsigned char)(table[ 494 (unsigned char)(table[i]->seq >> 8),
495 (unsigned char)(table[ 495 (unsigned char)(table[i]->seq >> 0),
496 table[i]->sym); 496 table[i]->sym);
497 printf("\n"); 497 printf("\n");
498 } 498 }
499 499
500 500
501 /* table lookup compression functions */ 501 /* table lookup compression functions */
502 502
503 /* count all the possible tokens in a symbol * 503 /* count all the possible tokens in a symbol */
504 static void learn_symbol(const unsigned char * 504 static void learn_symbol(const unsigned char *symbol, int len)
505 { 505 {
506 int i; 506 int i;
507 507
508 for (i = 0; i < len - 1; i++) 508 for (i = 0; i < len - 1; i++)
509 token_profit[ symbol[i] + (sym 509 token_profit[ symbol[i] + (symbol[i + 1] << 8) ]++;
510 } 510 }
511 511
512 /* decrease the count for all the possible tok 512 /* decrease the count for all the possible tokens in a symbol */
513 static void forget_symbol(const unsigned char 513 static void forget_symbol(const unsigned char *symbol, int len)
514 { 514 {
515 int i; 515 int i;
516 516
517 for (i = 0; i < len - 1; i++) 517 for (i = 0; i < len - 1; i++)
518 token_profit[ symbol[i] + (sym 518 token_profit[ symbol[i] + (symbol[i + 1] << 8) ]--;
519 } 519 }
520 520
521 /* do the initial token count */ 521 /* do the initial token count */
522 static void build_initial_token_table(void) 522 static void build_initial_token_table(void)
523 { 523 {
524 unsigned int i; 524 unsigned int i;
525 525
526 for (i = 0; i < table_cnt; i++) 526 for (i = 0; i < table_cnt; i++)
527 learn_symbol(table[i]->sym, ta 527 learn_symbol(table[i]->sym, table[i]->len);
528 } 528 }
529 529
530 static unsigned char *find_token(unsigned char 530 static unsigned char *find_token(unsigned char *str, int len,
531 const unsigne 531 const unsigned char *token)
532 { 532 {
533 int i; 533 int i;
534 534
535 for (i = 0; i < len - 1; i++) { 535 for (i = 0; i < len - 1; i++) {
536 if (str[i] == token[0] && str[ 536 if (str[i] == token[0] && str[i+1] == token[1])
537 return &str[i]; 537 return &str[i];
538 } 538 }
539 return NULL; 539 return NULL;
540 } 540 }
541 541
542 /* replace a given token in all the valid symb 542 /* replace a given token in all the valid symbols. Use the sampled symbols
543 * to update the counts */ 543 * to update the counts */
544 static void compress_symbols(const unsigned ch 544 static void compress_symbols(const unsigned char *str, int idx)
545 { 545 {
546 unsigned int i, len, size; 546 unsigned int i, len, size;
547 unsigned char *p1, *p2; 547 unsigned char *p1, *p2;
548 548
549 for (i = 0; i < table_cnt; i++) { 549 for (i = 0; i < table_cnt; i++) {
550 550
551 len = table[i]->len; 551 len = table[i]->len;
552 p1 = table[i]->sym; 552 p1 = table[i]->sym;
553 553
554 /* find the token on the symbo 554 /* find the token on the symbol */
555 p2 = find_token(p1, len, str); 555 p2 = find_token(p1, len, str);
556 if (!p2) continue; 556 if (!p2) continue;
557 557
558 /* decrease the counts for thi 558 /* decrease the counts for this symbol's tokens */
559 forget_symbol(table[i]->sym, l 559 forget_symbol(table[i]->sym, len);
560 560
561 size = len; 561 size = len;
562 562
563 do { 563 do {
564 *p2 = idx; 564 *p2 = idx;
565 p2++; 565 p2++;
566 size -= (p2 - p1); 566 size -= (p2 - p1);
567 memmove(p2, p2 + 1, si 567 memmove(p2, p2 + 1, size);
568 p1 = p2; 568 p1 = p2;
569 len--; 569 len--;
570 570
571 if (size < 2) break; 571 if (size < 2) break;
572 572
573 /* find the token on t 573 /* find the token on the symbol */
574 p2 = find_token(p1, si 574 p2 = find_token(p1, size, str);
575 575
576 } while (p2); 576 } while (p2);
577 577
578 table[i]->len = len; 578 table[i]->len = len;
579 579
580 /* increase the counts for thi 580 /* increase the counts for this symbol's new tokens */
581 learn_symbol(table[i]->sym, le 581 learn_symbol(table[i]->sym, len);
582 } 582 }
583 } 583 }
584 584
585 /* search the token with the maximum profit */ 585 /* search the token with the maximum profit */
586 static int find_best_token(void) 586 static int find_best_token(void)
587 { 587 {
588 int i, best, bestprofit; 588 int i, best, bestprofit;
589 589
590 bestprofit=-10000; 590 bestprofit=-10000;
591 best = 0; 591 best = 0;
592 592
593 for (i = 0; i < 0x10000; i++) { 593 for (i = 0; i < 0x10000; i++) {
594 if (token_profit[i] > bestprof 594 if (token_profit[i] > bestprofit) {
595 best = i; 595 best = i;
596 bestprofit = token_pro 596 bestprofit = token_profit[i];
597 } 597 }
598 } 598 }
599 return best; 599 return best;
600 } 600 }
601 601
602 /* this is the core of the algorithm: calculat 602 /* this is the core of the algorithm: calculate the "best" table */
603 static void optimize_result(void) 603 static void optimize_result(void)
604 { 604 {
605 int i, best; 605 int i, best;
606 606
607 /* using the '\0' symbol last allows c 607 /* using the '\0' symbol last allows compress_symbols to use standard
608 * fast string functions */ 608 * fast string functions */
609 for (i = 255; i >= 0; i--) { 609 for (i = 255; i >= 0; i--) {
610 610
611 /* if this table slot is empty 611 /* if this table slot is empty (it is not used by an actual
612 * original char code */ 612 * original char code */
613 if (!best_table_len[i]) { 613 if (!best_table_len[i]) {
614 614
615 /* find the token with 615 /* find the token with the best profit value */
616 best = find_best_token 616 best = find_best_token();
617 if (token_profit[best] 617 if (token_profit[best] == 0)
618 break; 618 break;
619 619
620 /* place it in the "be 620 /* place it in the "best" table */
621 best_table_len[i] = 2; 621 best_table_len[i] = 2;
622 best_table[i][0] = bes 622 best_table[i][0] = best & 0xFF;
623 best_table[i][1] = (be 623 best_table[i][1] = (best >> 8) & 0xFF;
624 624
625 /* replace this token 625 /* replace this token in all the valid symbols */
626 compress_symbols(best_ 626 compress_symbols(best_table[i], i);
627 } 627 }
628 } 628 }
629 } 629 }
630 630
631 /* start by placing the symbols that are actua 631 /* start by placing the symbols that are actually used on the table */
632 static void insert_real_symbols_in_table(void) 632 static void insert_real_symbols_in_table(void)
633 { 633 {
634 unsigned int i, j, c; 634 unsigned int i, j, c;
635 635
636 for (i = 0; i < table_cnt; i++) { 636 for (i = 0; i < table_cnt; i++) {
637 for (j = 0; j < table[i]->len; 637 for (j = 0; j < table[i]->len; j++) {
638 c = table[i]->sym[j]; 638 c = table[i]->sym[j];
639 best_table[c][0]=c; 639 best_table[c][0]=c;
640 best_table_len[c]=1; 640 best_table_len[c]=1;
641 } 641 }
642 } 642 }
643 } 643 }
644 644
645 static void optimize_token_table(void) 645 static void optimize_token_table(void)
646 { 646 {
647 build_initial_token_table(); 647 build_initial_token_table();
648 648
649 insert_real_symbols_in_table(); 649 insert_real_symbols_in_table();
650 650
651 optimize_result(); 651 optimize_result();
652 } 652 }
653 653
654 /* guess for "linker script provide" symbol */ 654 /* guess for "linker script provide" symbol */
655 static int may_be_linker_script_provide_symbol 655 static int may_be_linker_script_provide_symbol(const struct sym_entry *se)
656 { 656 {
657 const char *symbol = sym_name(se); 657 const char *symbol = sym_name(se);
658 int len = se->len - 1; 658 int len = se->len - 1;
659 659
660 if (len < 8) 660 if (len < 8)
661 return 0; 661 return 0;
662 662
663 if (symbol[0] != '_' || symbol[1] != ' 663 if (symbol[0] != '_' || symbol[1] != '_')
664 return 0; 664 return 0;
665 665
666 /* __start_XXXXX */ 666 /* __start_XXXXX */
667 if (!memcmp(symbol + 2, "start_", 6)) 667 if (!memcmp(symbol + 2, "start_", 6))
668 return 1; 668 return 1;
669 669
670 /* __stop_XXXXX */ 670 /* __stop_XXXXX */
671 if (!memcmp(symbol + 2, "stop_", 5)) 671 if (!memcmp(symbol + 2, "stop_", 5))
672 return 1; 672 return 1;
673 673
674 /* __end_XXXXX */ 674 /* __end_XXXXX */
675 if (!memcmp(symbol + 2, "end_", 4)) 675 if (!memcmp(symbol + 2, "end_", 4))
676 return 1; 676 return 1;
677 677
678 /* __XXXXX_start */ 678 /* __XXXXX_start */
679 if (!memcmp(symbol + len - 6, "_start" 679 if (!memcmp(symbol + len - 6, "_start", 6))
680 return 1; 680 return 1;
681 681
682 /* __XXXXX_end */ 682 /* __XXXXX_end */
683 if (!memcmp(symbol + len - 4, "_end", 683 if (!memcmp(symbol + len - 4, "_end", 4))
684 return 1; 684 return 1;
685 685
686 return 0; 686 return 0;
687 } 687 }
688 688
689 static int compare_symbols(const void *a, cons 689 static int compare_symbols(const void *a, const void *b)
690 { 690 {
691 const struct sym_entry *sa = *(const s 691 const struct sym_entry *sa = *(const struct sym_entry **)a;
692 const struct sym_entry *sb = *(const s 692 const struct sym_entry *sb = *(const struct sym_entry **)b;
693 int wa, wb; 693 int wa, wb;
694 694
695 /* sort by address first */ 695 /* sort by address first */
696 if (sa->addr > sb->addr) 696 if (sa->addr > sb->addr)
697 return 1; 697 return 1;
698 if (sa->addr < sb->addr) 698 if (sa->addr < sb->addr)
699 return -1; 699 return -1;
700 700
701 /* sort by "weakness" type */ 701 /* sort by "weakness" type */
702 wa = (sa->sym[0] == 'w') || (sa->sym[0 702 wa = (sa->sym[0] == 'w') || (sa->sym[0] == 'W');
703 wb = (sb->sym[0] == 'w') || (sb->sym[0 703 wb = (sb->sym[0] == 'w') || (sb->sym[0] == 'W');
704 if (wa != wb) 704 if (wa != wb)
705 return wa - wb; 705 return wa - wb;
706 706
707 /* sort by "linker script provide" typ 707 /* sort by "linker script provide" type */
708 wa = may_be_linker_script_provide_symb 708 wa = may_be_linker_script_provide_symbol(sa);
709 wb = may_be_linker_script_provide_symb 709 wb = may_be_linker_script_provide_symbol(sb);
710 if (wa != wb) 710 if (wa != wb)
711 return wa - wb; 711 return wa - wb;
712 712
713 /* sort by the number of prefix unders 713 /* sort by the number of prefix underscores */
714 wa = strspn(sym_name(sa), "_"); 714 wa = strspn(sym_name(sa), "_");
715 wb = strspn(sym_name(sb), "_"); 715 wb = strspn(sym_name(sb), "_");
716 if (wa != wb) 716 if (wa != wb)
717 return wa - wb; 717 return wa - wb;
718 718
719 /* sort by initial order, so that othe 719 /* sort by initial order, so that other symbols are left undisturbed */
720 return sa->seq - sb->seq; 720 return sa->seq - sb->seq;
721 } 721 }
722 722
723 static void sort_symbols(void) 723 static void sort_symbols(void)
724 { 724 {
725 qsort(table, table_cnt, sizeof(table[0 725 qsort(table, table_cnt, sizeof(table[0]), compare_symbols);
726 } 726 }
727 727
728 static void make_percpus_absolute(void) 728 static void make_percpus_absolute(void)
729 { 729 {
730 unsigned int i; 730 unsigned int i;
731 731
732 for (i = 0; i < table_cnt; i++) 732 for (i = 0; i < table_cnt; i++)
733 if (symbol_in_range(table[i], 733 if (symbol_in_range(table[i], &percpu_range, 1)) {
734 /* 734 /*
735 * Keep the 'A' overri 735 * Keep the 'A' override for percpu symbols to
736 * ensure consistent b 736 * ensure consistent behavior compared to older
737 * versions of this to 737 * versions of this tool.
738 */ 738 */
739 table[i]->sym[0] = 'A' 739 table[i]->sym[0] = 'A';
740 table[i]->percpu_absol 740 table[i]->percpu_absolute = true;
741 } 741 }
742 } 742 }
743 743
744 /* find the minimum non-absolute symbol addres 744 /* find the minimum non-absolute symbol address */
745 static void record_relative_base(void) 745 static void record_relative_base(void)
746 { 746 {
747 unsigned int i; 747 unsigned int i;
748 748
749 for (i = 0; i < table_cnt; i++) 749 for (i = 0; i < table_cnt; i++)
750 if (!symbol_absolute(table[i]) 750 if (!symbol_absolute(table[i])) {
751 /* 751 /*
752 * The table is sorted 752 * The table is sorted by address.
753 * Take the first non- 753 * Take the first non-absolute symbol value.
754 */ 754 */
755 relative_base = table[ 755 relative_base = table[i]->addr;
756 return; 756 return;
757 } 757 }
758 } 758 }
759 759
760 int main(int argc, char **argv) 760 int main(int argc, char **argv)
761 { 761 {
762 while (1) { 762 while (1) {
763 static const struct option lon 763 static const struct option long_options[] = {
764 {"all-symbols", no 764 {"all-symbols", no_argument, &all_symbols, 1},
765 {"absolute-percpu", no 765 {"absolute-percpu", no_argument, &absolute_percpu, 1},
766 {}, 766 {},
767 }; 767 };
768 768
769 int c = getopt_long(argc, argv 769 int c = getopt_long(argc, argv, "", long_options, NULL);
770 770
771 if (c == -1) 771 if (c == -1)
772 break; 772 break;
773 if (c != 0) 773 if (c != 0)
774 usage(); 774 usage();
775 } 775 }
776 776
777 if (optind >= argc) 777 if (optind >= argc)
778 usage(); 778 usage();
779 779
780 read_map(argv[optind]); 780 read_map(argv[optind]);
781 shrink_table(); 781 shrink_table();
782 if (absolute_percpu) 782 if (absolute_percpu)
783 make_percpus_absolute(); 783 make_percpus_absolute();
784 sort_symbols(); 784 sort_symbols();
785 record_relative_base(); 785 record_relative_base();
786 optimize_token_table(); 786 optimize_token_table();
787 write_src(); 787 write_src();
788 788
789 return 0; 789 return 0;
790 } 790 }
791 791
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