Blame view
kernel/kallsyms.c
12.4 KB
1da177e4c
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 |
/* * kallsyms.c: in-kernel printing of symbolic oopses and stack traces. * * Rewritten and vastly simplified by Rusty Russell for in-kernel * module loader: * Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation * * ChangeLog: * * (25/Aug/2004) Paulo Marques <pmarques@grupopie.com> * Changed the compression method from stem compression to "table lookup" * compression (see scripts/kallsyms.c for a more complete description) */ #include <linux/kallsyms.h> #include <linux/module.h> #include <linux/init.h> #include <linux/seq_file.h> #include <linux/fs.h> #include <linux/err.h> #include <linux/proc_fs.h> |
4e57b6817
|
21 |
#include <linux/sched.h> /* for cond_resched */ |
1da177e4c
|
22 |
#include <linux/mm.h> |
07354a009
|
23 |
#include <linux/ctype.h> |
5a0e3ad6a
|
24 |
#include <linux/slab.h> |
1da177e4c
|
25 26 27 28 29 30 31 32 |
#include <asm/sections.h> #ifdef CONFIG_KALLSYMS_ALL #define all_var 1 #else #define all_var 0 #endif |
ad6ccfad6
|
33 34 35 36 |
/* * These will be re-linked against their real values * during the second link stage. */ |
2ea038917
|
37 38 |
extern const unsigned long kallsyms_addresses[] __attribute__((weak)); extern const u8 kallsyms_names[] __attribute__((weak)); |
1da177e4c
|
39 |
|
ad6ccfad6
|
40 41 42 |
/* * Tell the compiler that the count isn't in the small data section if the arch * has one (eg: FRV). |
9e6c1e633
|
43 44 |
*/ extern const unsigned long kallsyms_num_syms |
2ea038917
|
45 |
__attribute__((weak, section(".rodata"))); |
9e6c1e633
|
46 |
|
2ea038917
|
47 48 |
extern const u8 kallsyms_token_table[] __attribute__((weak)); extern const u16 kallsyms_token_index[] __attribute__((weak)); |
1da177e4c
|
49 |
|
2ea038917
|
50 |
extern const unsigned long kallsyms_markers[] __attribute__((weak)); |
1da177e4c
|
51 52 53 54 55 56 57 58 59 60 61 |
static inline int is_kernel_inittext(unsigned long addr) { if (addr >= (unsigned long)_sinittext && addr <= (unsigned long)_einittext) return 1; return 0; } static inline int is_kernel_text(unsigned long addr) { |
128e8db38
|
62 63 |
if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) || arch_is_kernel_text(addr)) |
1da177e4c
|
64 65 66 67 68 69 70 71 72 73 |
return 1; return in_gate_area_no_task(addr); } static inline int is_kernel(unsigned long addr) { if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end) return 1; return in_gate_area_no_task(addr); } |
ffc508919
|
74 75 76 77 |
static int is_ksym_addr(unsigned long addr) { if (all_var) return is_kernel(addr); |
a3b81113f
|
78 |
return is_kernel_text(addr) || is_kernel_inittext(addr); |
ffc508919
|
79 |
} |
ad6ccfad6
|
80 81 82 83 |
/* * Expand a compressed symbol data into the resulting uncompressed string, * given the offset to where the symbol is in the compressed stream. */ |
1da177e4c
|
84 85 86 |
static unsigned int kallsyms_expand_symbol(unsigned int off, char *result) { int len, skipped_first = 0; |
aad094701
|
87 |
const u8 *tptr, *data; |
1da177e4c
|
88 |
|
ad6ccfad6
|
89 |
/* Get the compressed symbol length from the first symbol byte. */ |
1da177e4c
|
90 91 92 |
data = &kallsyms_names[off]; len = *data; data++; |
ad6ccfad6
|
93 94 95 96 |
/* * Update the offset to return the offset for the next symbol on * the compressed stream. */ |
1da177e4c
|
97 |
off += len + 1; |
ad6ccfad6
|
98 99 100 101 102 103 |
/* * For every byte on the compressed symbol data, copy the table * entry for that byte. */ while (len) { tptr = &kallsyms_token_table[kallsyms_token_index[*data]]; |
1da177e4c
|
104 105 106 107 |
data++; len--; while (*tptr) { |
ad6ccfad6
|
108 |
if (skipped_first) { |
1da177e4c
|
109 110 111 112 113 114 115 116 117 |
*result = *tptr; result++; } else skipped_first = 1; tptr++; } } *result = '\0'; |
ad6ccfad6
|
118 |
/* Return to offset to the next symbol. */ |
1da177e4c
|
119 120 |
return off; } |
ad6ccfad6
|
121 122 123 124 |
/* * Get symbol type information. This is encoded as a single char at the * beginning of the symbol name. */ |
1da177e4c
|
125 126 |
static char kallsyms_get_symbol_type(unsigned int off) { |
ad6ccfad6
|
127 128 129 130 131 |
/* * Get just the first code, look it up in the token table, * and return the first char from this token. */ return kallsyms_token_table[kallsyms_token_index[kallsyms_names[off + 1]]]; |
1da177e4c
|
132 |
} |
ad6ccfad6
|
133 134 135 136 |
/* * Find the offset on the compressed stream given and index in the * kallsyms array. */ |
1da177e4c
|
137 138 |
static unsigned int get_symbol_offset(unsigned long pos) { |
aad094701
|
139 |
const u8 *name; |
1da177e4c
|
140 |
int i; |
ad6ccfad6
|
141 142 143 144 145 |
/* * Use the closest marker we have. We have markers every 256 positions, * so that should be close enough. */ name = &kallsyms_names[kallsyms_markers[pos >> 8]]; |
1da177e4c
|
146 |
|
ad6ccfad6
|
147 148 149 150 151 152 153 |
/* * Sequentially scan all the symbols up to the point we're searching * for. Every symbol is stored in a [<len>][<len> bytes of data] format, * so we just need to add the len to the current pointer for every * symbol we wish to skip. */ for (i = 0; i < (pos & 0xFF); i++) |
1da177e4c
|
154 155 156 157 158 159 160 161 |
name = name + (*name) + 1; return name - kallsyms_names; } /* Lookup the address for this symbol. Returns 0 if not found. */ unsigned long kallsyms_lookup_name(const char *name) { |
9281acea6
|
162 |
char namebuf[KSYM_NAME_LEN]; |
1da177e4c
|
163 164 165 166 167 168 169 170 171 172 173 |
unsigned long i; unsigned int off; for (i = 0, off = 0; i < kallsyms_num_syms; i++) { off = kallsyms_expand_symbol(off, namebuf); if (strcmp(namebuf, name) == 0) return kallsyms_addresses[i]; } return module_kallsyms_lookup_name(name); } |
f60d24d2a
|
174 |
EXPORT_SYMBOL_GPL(kallsyms_lookup_name); |
1da177e4c
|
175 |
|
75a66614d
|
176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 |
int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, unsigned long), void *data) { char namebuf[KSYM_NAME_LEN]; unsigned long i; unsigned int off; int ret; for (i = 0, off = 0; i < kallsyms_num_syms; i++) { off = kallsyms_expand_symbol(off, namebuf); ret = fn(data, namebuf, NULL, kallsyms_addresses[i]); if (ret != 0) return ret; } return module_kallsyms_on_each_symbol(fn, data); } EXPORT_SYMBOL_GPL(kallsyms_on_each_symbol); |
ffc508919
|
194 195 196 197 198 199 |
static unsigned long get_symbol_pos(unsigned long addr, unsigned long *symbolsize, unsigned long *offset) { unsigned long symbol_start = 0, symbol_end = 0; unsigned long i, low, high, mid; |
2ea038917
|
200 201 |
/* This kernel should never had been booted. */ BUG_ON(!kallsyms_addresses); |
ad6ccfad6
|
202 |
/* Do a binary search on the sorted kallsyms_addresses array. */ |
ffc508919
|
203 204 205 206 |
low = 0; high = kallsyms_num_syms; while (high - low > 1) { |
2fc9c4e18
|
207 |
mid = low + (high - low) / 2; |
ffc508919
|
208 209 210 211 212 213 214 |
if (kallsyms_addresses[mid] <= addr) low = mid; else high = mid; } /* |
ad6ccfad6
|
215 216 |
* Search for the first aliased symbol. Aliased * symbols are symbols with the same address. |
ffc508919
|
217 218 219 220 221 |
*/ while (low && kallsyms_addresses[low-1] == kallsyms_addresses[low]) --low; symbol_start = kallsyms_addresses[low]; |
ad6ccfad6
|
222 |
/* Search for next non-aliased symbol. */ |
ffc508919
|
223 224 225 226 227 228 |
for (i = low + 1; i < kallsyms_num_syms; i++) { if (kallsyms_addresses[i] > symbol_start) { symbol_end = kallsyms_addresses[i]; break; } } |
ad6ccfad6
|
229 |
/* If we found no next symbol, we use the end of the section. */ |
ffc508919
|
230 231 232 233 234 235 236 237 |
if (!symbol_end) { if (is_kernel_inittext(addr)) symbol_end = (unsigned long)_einittext; else if (all_var) symbol_end = (unsigned long)_end; else symbol_end = (unsigned long)_etext; } |
ffb451227
|
238 239 240 241 |
if (symbolsize) *symbolsize = symbol_end - symbol_start; if (offset) *offset = addr - symbol_start; |
ffc508919
|
242 243 244 245 246 247 248 249 250 251 |
return low; } /* * Lookup an address but don't bother to find any names. */ int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize, unsigned long *offset) { |
6dd06c9fb
|
252 |
char namebuf[KSYM_NAME_LEN]; |
ffc508919
|
253 254 |
if (is_ksym_addr(addr)) return !!get_symbol_pos(addr, symbolsize, offset); |
6dd06c9fb
|
255 |
return !!module_address_lookup(addr, symbolsize, offset, NULL, namebuf); |
ffc508919
|
256 |
} |
1da177e4c
|
257 258 |
/* * Lookup an address |
ad6ccfad6
|
259 260 261 262 |
* - modname is set to NULL if it's in the kernel. * - We guarantee that the returned name is valid until we reschedule even if. * It resides in a module. * - We also guarantee that modname will be valid until rescheduled. |
1da177e4c
|
263 264 265 266 267 268 |
*/ const char *kallsyms_lookup(unsigned long addr, unsigned long *symbolsize, unsigned long *offset, char **modname, char *namebuf) { |
9281acea6
|
269 |
namebuf[KSYM_NAME_LEN - 1] = 0; |
1da177e4c
|
270 |
namebuf[0] = 0; |
ffc508919
|
271 272 |
if (is_ksym_addr(addr)) { unsigned long pos; |
1da177e4c
|
273 |
|
ffc508919
|
274 |
pos = get_symbol_pos(addr, symbolsize, offset); |
1da177e4c
|
275 |
/* Grab name */ |
ffc508919
|
276 |
kallsyms_expand_symbol(get_symbol_offset(pos), namebuf); |
7a74fc492
|
277 278 |
if (modname) *modname = NULL; |
1da177e4c
|
279 280 |
return namebuf; } |
ad6ccfad6
|
281 |
/* See if it's in a module. */ |
6dd06c9fb
|
282 283 |
return module_address_lookup(addr, symbolsize, offset, modname, namebuf); |
1da177e4c
|
284 |
} |
9d65cb4a1
|
285 286 287 |
int lookup_symbol_name(unsigned long addr, char *symname) { symname[0] = '\0'; |
9281acea6
|
288 |
symname[KSYM_NAME_LEN - 1] = '\0'; |
9d65cb4a1
|
289 290 291 292 293 294 295 296 297 |
if (is_ksym_addr(addr)) { unsigned long pos; pos = get_symbol_pos(addr, NULL, NULL); /* Grab name */ kallsyms_expand_symbol(get_symbol_offset(pos), symname); return 0; } |
ad6ccfad6
|
298 |
/* See if it's in a module. */ |
9d65cb4a1
|
299 300 |
return lookup_module_symbol_name(addr, symname); } |
a5c43dae7
|
301 302 303 304 |
int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name) { name[0] = '\0'; |
9281acea6
|
305 |
name[KSYM_NAME_LEN - 1] = '\0'; |
a5c43dae7
|
306 307 308 309 310 311 312 313 314 315 |
if (is_ksym_addr(addr)) { unsigned long pos; pos = get_symbol_pos(addr, size, offset); /* Grab name */ kallsyms_expand_symbol(get_symbol_offset(pos), name); modname[0] = '\0'; return 0; } |
ad6ccfad6
|
316 |
/* See if it's in a module. */ |
a5c43dae7
|
317 318 |
return lookup_module_symbol_attrs(addr, size, offset, modname, name); } |
42e380832
|
319 320 |
/* Look up a kernel symbol and return it in a text buffer. */ int sprint_symbol(char *buffer, unsigned long address) |
1da177e4c
|
321 322 323 324 |
{ char *modname; const char *name; unsigned long offset, size; |
966c8c12d
|
325 |
int len; |
1da177e4c
|
326 |
|
966c8c12d
|
327 |
name = kallsyms_lookup(address, &size, &offset, &modname, buffer); |
1da177e4c
|
328 |
if (!name) |
42e380832
|
329 |
return sprintf(buffer, "0x%lx", address); |
19769b762
|
330 |
|
966c8c12d
|
331 332 333 334 |
if (name != buffer) strcpy(buffer, name); len = strlen(buffer); buffer += len; |
19769b762
|
335 |
if (modname) |
966c8c12d
|
336 337 |
len += sprintf(buffer, "+%#lx/%#lx [%s]", offset, size, modname); |
19769b762
|
338 |
else |
966c8c12d
|
339 340 341 |
len += sprintf(buffer, "+%#lx/%#lx", offset, size); return len; |
42e380832
|
342 |
} |
ad6ccfad6
|
343 |
EXPORT_SYMBOL_GPL(sprint_symbol); |
42e380832
|
344 345 346 347 348 349 350 |
/* Look up a kernel symbol and print it to the kernel messages. */ void __print_symbol(const char *fmt, unsigned long address) { char buffer[KSYM_SYMBOL_LEN]; sprint_symbol(buffer, address); |
1da177e4c
|
351 352 |
printk(fmt, buffer); } |
ad6ccfad6
|
353 |
EXPORT_SYMBOL(__print_symbol); |
1da177e4c
|
354 355 |
/* To avoid using get_symbol_offset for every symbol, we carry prefix along. */ |
ad6ccfad6
|
356 |
struct kallsym_iter { |
1da177e4c
|
357 |
loff_t pos; |
1da177e4c
|
358 |
unsigned long value; |
ad6ccfad6
|
359 |
unsigned int nameoff; /* If iterating in core kernel symbols. */ |
1da177e4c
|
360 |
char type; |
9281acea6
|
361 362 |
char name[KSYM_NAME_LEN]; char module_name[MODULE_NAME_LEN]; |
ea07890a6
|
363 |
int exported; |
1da177e4c
|
364 |
}; |
1da177e4c
|
365 366 |
static int get_ksymbol_mod(struct kallsym_iter *iter) { |
ea07890a6
|
367 368 369 |
if (module_get_kallsym(iter->pos - kallsyms_num_syms, &iter->value, &iter->type, iter->name, iter->module_name, &iter->exported) < 0) |
1da177e4c
|
370 |
return 0; |
1da177e4c
|
371 372 373 374 375 376 377 |
return 1; } /* Returns space to next name. */ static unsigned long get_ksymbol_core(struct kallsym_iter *iter) { unsigned off = iter->nameoff; |
ea07890a6
|
378 |
iter->module_name[0] = '\0'; |
1da177e4c
|
379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 |
iter->value = kallsyms_addresses[iter->pos]; iter->type = kallsyms_get_symbol_type(off); off = kallsyms_expand_symbol(off, iter->name); return off - iter->nameoff; } static void reset_iter(struct kallsym_iter *iter, loff_t new_pos) { iter->name[0] = '\0'; iter->nameoff = get_symbol_offset(new_pos); iter->pos = new_pos; } /* Returns false if pos at or past end of file. */ static int update_iter(struct kallsym_iter *iter, loff_t pos) { /* Module symbols can be accessed randomly. */ if (pos >= kallsyms_num_syms) { iter->pos = pos; return get_ksymbol_mod(iter); } |
ad6ccfad6
|
403 |
|
1da177e4c
|
404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 |
/* If we're not on the desired position, reset to new position. */ if (pos != iter->pos) reset_iter(iter, pos); iter->nameoff += get_ksymbol_core(iter); iter->pos++; return 1; } static void *s_next(struct seq_file *m, void *p, loff_t *pos) { (*pos)++; if (!update_iter(m->private, *pos)) return NULL; return p; } static void *s_start(struct seq_file *m, loff_t *pos) { if (!update_iter(m->private, *pos)) return NULL; return m->private; } static void s_stop(struct seq_file *m, void *p) { } static int s_show(struct seq_file *m, void *p) { struct kallsym_iter *iter = m->private; |
ad6ccfad6
|
437 |
/* Some debugging symbols have no name. Ignore them. */ |
1da177e4c
|
438 439 |
if (!iter->name[0]) return 0; |
ea07890a6
|
440 441 |
if (iter->module_name[0]) { char type; |
ad6ccfad6
|
442 443 444 445 |
/* * Label it "global" if it is exported, * "local" if not exported. */ |
ea07890a6
|
446 447 |
type = iter->exported ? toupper(iter->type) : tolower(iter->type); |
1da177e4c
|
448 449 |
seq_printf(m, "%0*lx %c %s\t[%s] ", |
ad6ccfad6
|
450 |
(int)(2 * sizeof(void *)), |
ea07890a6
|
451 452 |
iter->value, type, iter->name, iter->module_name); } else |
1da177e4c
|
453 454 |
seq_printf(m, "%0*lx %c %s ", |
ad6ccfad6
|
455 |
(int)(2 * sizeof(void *)), |
1da177e4c
|
456 457 458 |
iter->value, iter->type, iter->name); return 0; } |
15ad7cdcf
|
459 |
static const struct seq_operations kallsyms_op = { |
1da177e4c
|
460 461 462 463 464 465 466 467 |
.start = s_start, .next = s_next, .stop = s_stop, .show = s_show }; static int kallsyms_open(struct inode *inode, struct file *file) { |
ad6ccfad6
|
468 469 |
/* * We keep iterator in m->private, since normal case is to |
1da177e4c
|
470 |
* s_start from where we left off, so we avoid doing |
ad6ccfad6
|
471 472 |
* using get_symbol_offset for every symbol. */ |
1da177e4c
|
473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 |
struct kallsym_iter *iter; int ret; iter = kmalloc(sizeof(*iter), GFP_KERNEL); if (!iter) return -ENOMEM; reset_iter(iter, 0); ret = seq_open(file, &kallsyms_op); if (ret == 0) ((struct seq_file *)file->private_data)->private = iter; else kfree(iter); return ret; } |
15ad7cdcf
|
488 |
static const struct file_operations kallsyms_operations = { |
1da177e4c
|
489 490 491 |
.open = kallsyms_open, .read = seq_read, .llseek = seq_lseek, |
5a0c6a0d1
|
492 |
.release = seq_release_private, |
1da177e4c
|
493 494 495 496 |
}; static int __init kallsyms_init(void) { |
c33fff0af
|
497 |
proc_create("kallsyms", 0444, NULL, &kallsyms_operations); |
1da177e4c
|
498 499 |
return 0; } |
ad6ccfad6
|
500 |
device_initcall(kallsyms_init); |