1 // SPDX-License-Identifier: GPL-2.0-only 1 // SPDX-License-Identifier: GPL-2.0-only
2 /* 2 /*
3 * kallsyms.c: in-kernel printing of symbolic 3 * kallsyms.c: in-kernel printing of symbolic oopses and stack traces.
4 * 4 *
5 * Rewritten and vastly simplified by Rusty Ru 5 * Rewritten and vastly simplified by Rusty Russell for in-kernel
6 * module loader: 6 * module loader:
7 * Copyright 2002 Rusty Russell <rusty@rustc 7 * Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
8 * 8 *
9 * ChangeLog: 9 * ChangeLog:
10 * 10 *
11 * (25/Aug/2004) Paulo Marques <pmarques@grupo 11 * (25/Aug/2004) Paulo Marques <pmarques@grupopie.com>
12 * Changed the compression method from st 12 * Changed the compression method from stem compression to "table lookup"
13 * compression (see scripts/kallsyms.c fo 13 * compression (see scripts/kallsyms.c for a more complete description)
14 */ 14 */
15 #include <linux/kallsyms.h> 15 #include <linux/kallsyms.h>
16 #include <linux/init.h> 16 #include <linux/init.h>
17 #include <linux/seq_file.h> 17 #include <linux/seq_file.h>
18 #include <linux/fs.h> 18 #include <linux/fs.h>
19 #include <linux/kdb.h> 19 #include <linux/kdb.h>
20 #include <linux/err.h> 20 #include <linux/err.h>
21 #include <linux/proc_fs.h> 21 #include <linux/proc_fs.h>
22 #include <linux/sched.h> /* for cond_re 22 #include <linux/sched.h> /* for cond_resched */
23 #include <linux/ctype.h> 23 #include <linux/ctype.h>
24 #include <linux/slab.h> 24 #include <linux/slab.h>
25 #include <linux/filter.h> 25 #include <linux/filter.h>
26 #include <linux/ftrace.h> 26 #include <linux/ftrace.h>
27 #include <linux/kprobes.h> 27 #include <linux/kprobes.h>
28 #include <linux/build_bug.h> <<
29 #include <linux/compiler.h> 28 #include <linux/compiler.h>
30 #include <linux/module.h> <<
31 #include <linux/kernel.h> <<
32 #include <linux/bsearch.h> <<
33 #include <linux/btf_ids.h> <<
34 29
35 #include "kallsyms_internal.h" !! 30 /*
>> 31 * These will be re-linked against their real values
>> 32 * during the second link stage.
>> 33 */
>> 34 extern const unsigned long kallsyms_addresses[] __weak;
>> 35 extern const int kallsyms_offsets[] __weak;
>> 36 extern const u8 kallsyms_names[] __weak;
>> 37
>> 38 /*
>> 39 * Tell the compiler that the count isn't in the small data section if the arch
>> 40 * has one (eg: FRV).
>> 41 */
>> 42 extern const unsigned int kallsyms_num_syms
>> 43 __attribute__((weak, section(".rodata")));
>> 44
>> 45 extern const unsigned long kallsyms_relative_base
>> 46 __attribute__((weak, section(".rodata")));
>> 47
>> 48 extern const char kallsyms_token_table[] __weak;
>> 49 extern const u16 kallsyms_token_index[] __weak;
>> 50
>> 51 extern const unsigned int kallsyms_markers[] __weak;
36 52
37 /* 53 /*
38 * Expand a compressed symbol data into the re 54 * Expand a compressed symbol data into the resulting uncompressed string,
39 * if uncompressed string is too long (>= maxl 55 * if uncompressed string is too long (>= maxlen), it will be truncated,
40 * given the offset to where the symbol is in 56 * given the offset to where the symbol is in the compressed stream.
41 */ 57 */
42 static unsigned int kallsyms_expand_symbol(uns 58 static unsigned int kallsyms_expand_symbol(unsigned int off,
43 cha 59 char *result, size_t maxlen)
44 { 60 {
45 int len, skipped_first = 0; 61 int len, skipped_first = 0;
46 const char *tptr; 62 const char *tptr;
47 const u8 *data; 63 const u8 *data;
48 64
49 /* Get the compressed symbol length fr 65 /* Get the compressed symbol length from the first symbol byte. */
50 data = &kallsyms_names[off]; 66 data = &kallsyms_names[off];
51 len = *data; 67 len = *data;
52 data++; 68 data++;
53 off++; <<
54 <<
55 /* If MSB is 1, it is a "big" symbol, <<
56 if ((len & 0x80) != 0) { <<
57 len = (len & 0x7F) | (*data << <<
58 data++; <<
59 off++; <<
60 } <<
61 69
62 /* 70 /*
63 * Update the offset to return the off 71 * Update the offset to return the offset for the next symbol on
64 * the compressed stream. 72 * the compressed stream.
65 */ 73 */
66 off += len; !! 74 off += len + 1;
67 75
68 /* 76 /*
69 * For every byte on the compressed sy 77 * For every byte on the compressed symbol data, copy the table
70 * entry for that byte. 78 * entry for that byte.
71 */ 79 */
72 while (len) { 80 while (len) {
73 tptr = &kallsyms_token_table[k 81 tptr = &kallsyms_token_table[kallsyms_token_index[*data]];
74 data++; 82 data++;
75 len--; 83 len--;
76 84
77 while (*tptr) { 85 while (*tptr) {
78 if (skipped_first) { 86 if (skipped_first) {
79 if (maxlen <= 87 if (maxlen <= 1)
80 goto t 88 goto tail;
81 *result = *tpt 89 *result = *tptr;
82 result++; 90 result++;
83 maxlen--; 91 maxlen--;
84 } else 92 } else
85 skipped_first 93 skipped_first = 1;
86 tptr++; 94 tptr++;
87 } 95 }
88 } 96 }
89 97
90 tail: 98 tail:
91 if (maxlen) 99 if (maxlen)
92 *result = '\0'; 100 *result = '\0';
93 101
94 /* Return to offset to the next symbol 102 /* Return to offset to the next symbol. */
95 return off; 103 return off;
96 } 104 }
97 105
98 /* 106 /*
99 * Get symbol type information. This is encode 107 * Get symbol type information. This is encoded as a single char at the
100 * beginning of the symbol name. 108 * beginning of the symbol name.
101 */ 109 */
102 static char kallsyms_get_symbol_type(unsigned 110 static char kallsyms_get_symbol_type(unsigned int off)
103 { 111 {
104 /* 112 /*
105 * Get just the first code, look it up 113 * Get just the first code, look it up in the token table,
106 * and return the first char from this 114 * and return the first char from this token.
107 */ 115 */
108 return kallsyms_token_table[kallsyms_t 116 return kallsyms_token_table[kallsyms_token_index[kallsyms_names[off + 1]]];
109 } 117 }
110 118
111 119
112 /* 120 /*
113 * Find the offset on the compressed stream gi 121 * Find the offset on the compressed stream given and index in the
114 * kallsyms array. 122 * kallsyms array.
115 */ 123 */
116 static unsigned int get_symbol_offset(unsigned 124 static unsigned int get_symbol_offset(unsigned long pos)
117 { 125 {
118 const u8 *name; 126 const u8 *name;
119 int i, len; !! 127 int i;
120 128
121 /* 129 /*
122 * Use the closest marker we have. We 130 * Use the closest marker we have. We have markers every 256 positions,
123 * so that should be close enough. 131 * so that should be close enough.
124 */ 132 */
125 name = &kallsyms_names[kallsyms_marker 133 name = &kallsyms_names[kallsyms_markers[pos >> 8]];
126 134
127 /* 135 /*
128 * Sequentially scan all the symbols u 136 * Sequentially scan all the symbols up to the point we're searching
129 * for. Every symbol is stored in a [< 137 * for. Every symbol is stored in a [<len>][<len> bytes of data] format,
130 * so we just need to add the len to t 138 * so we just need to add the len to the current pointer for every
131 * symbol we wish to skip. 139 * symbol we wish to skip.
132 */ 140 */
133 for (i = 0; i < (pos & 0xFF); i++) { !! 141 for (i = 0; i < (pos & 0xFF); i++)
134 len = *name; !! 142 name = name + (*name) + 1;
135 <<
136 /* <<
137 * If MSB is 1, it is a "big" <<
138 * the next byte (and skip it, <<
139 */ <<
140 if ((len & 0x80) != 0) <<
141 len = ((len & 0x7F) | <<
142 <<
143 name = name + len + 1; <<
144 } <<
145 143
146 return name - kallsyms_names; 144 return name - kallsyms_names;
147 } 145 }
148 146
149 unsigned long kallsyms_sym_address(int idx) !! 147 static unsigned long kallsyms_sym_address(int idx)
150 { 148 {
>> 149 if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE))
>> 150 return kallsyms_addresses[idx];
>> 151
151 /* values are unsigned offsets if --ab 152 /* values are unsigned offsets if --absolute-percpu is not in effect */
152 if (!IS_ENABLED(CONFIG_KALLSYMS_ABSOLU 153 if (!IS_ENABLED(CONFIG_KALLSYMS_ABSOLUTE_PERCPU))
153 return kallsyms_relative_base 154 return kallsyms_relative_base + (u32)kallsyms_offsets[idx];
154 155
155 /* ...otherwise, positive offsets are 156 /* ...otherwise, positive offsets are absolute values */
156 if (kallsyms_offsets[idx] >= 0) 157 if (kallsyms_offsets[idx] >= 0)
157 return kallsyms_offsets[idx]; 158 return kallsyms_offsets[idx];
158 159
159 /* ...and negative offsets are relativ 160 /* ...and negative offsets are relative to kallsyms_relative_base - 1 */
160 return kallsyms_relative_base - 1 - ka 161 return kallsyms_relative_base - 1 - kallsyms_offsets[idx];
161 } 162 }
162 163
163 static unsigned int get_symbol_seq(int index) <<
164 { <<
165 unsigned int i, seq = 0; <<
166 <<
167 for (i = 0; i < 3; i++) <<
168 seq = (seq << 8) | kallsyms_se <<
169 <<
170 return seq; <<
171 } <<
172 <<
173 static int kallsyms_lookup_names(const char *n <<
174 unsigned int <<
175 unsigned int <<
176 { <<
177 int ret; <<
178 int low, mid, high; <<
179 unsigned int seq, off; <<
180 char namebuf[KSYM_NAME_LEN]; <<
181 <<
182 low = 0; <<
183 high = kallsyms_num_syms - 1; <<
184 <<
185 while (low <= high) { <<
186 mid = low + (high - low) / 2; <<
187 seq = get_symbol_seq(mid); <<
188 off = get_symbol_offset(seq); <<
189 kallsyms_expand_symbol(off, na <<
190 ret = strcmp(name, namebuf); <<
191 if (ret > 0) <<
192 low = mid + 1; <<
193 else if (ret < 0) <<
194 high = mid - 1; <<
195 else <<
196 break; <<
197 } <<
198 <<
199 if (low > high) <<
200 return -ESRCH; <<
201 <<
202 low = mid; <<
203 while (low) { <<
204 seq = get_symbol_seq(low - 1); <<
205 off = get_symbol_offset(seq); <<
206 kallsyms_expand_symbol(off, na <<
207 if (strcmp(name, namebuf)) <<
208 break; <<
209 low--; <<
210 } <<
211 *start = low; <<
212 <<
213 if (end) { <<
214 high = mid; <<
215 while (high < kallsyms_num_sym <<
216 seq = get_symbol_seq(h <<
217 off = get_symbol_offse <<
218 kallsyms_expand_symbol <<
219 if (strcmp(name, nameb <<
220 break; <<
221 high++; <<
222 } <<
223 *end = high; <<
224 } <<
225 <<
226 return 0; <<
227 } <<
228 <<
229 /* Lookup the address for this symbol. Returns 164 /* Lookup the address for this symbol. Returns 0 if not found. */
230 unsigned long kallsyms_lookup_name(const char 165 unsigned long kallsyms_lookup_name(const char *name)
231 { 166 {
232 int ret; !! 167 char namebuf[KSYM_NAME_LEN];
233 unsigned int i; !! 168 unsigned long i;
234 !! 169 unsigned int off;
235 /* Skip the search for empty string. * <<
236 if (!*name) <<
237 return 0; <<
238 170
239 ret = kallsyms_lookup_names(name, &i, !! 171 for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
240 if (!ret) !! 172 off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
241 return kallsyms_sym_address(ge <<
242 173
>> 174 if (strcmp(namebuf, name) == 0)
>> 175 return kallsyms_sym_address(i);
>> 176 }
243 return module_kallsyms_lookup_name(nam 177 return module_kallsyms_lookup_name(name);
244 } 178 }
245 179
246 /* !! 180 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
247 * Iterate over all symbols in vmlinux. For s !! 181 unsigned long),
248 * module_kallsyms_on_each_symbol instead. <<
249 */ <<
250 int kallsyms_on_each_symbol(int (*fn)(void *, <<
251 void *data) 182 void *data)
252 { 183 {
253 char namebuf[KSYM_NAME_LEN]; 184 char namebuf[KSYM_NAME_LEN];
254 unsigned long i; 185 unsigned long i;
255 unsigned int off; 186 unsigned int off;
256 int ret; 187 int ret;
257 188
258 for (i = 0, off = 0; i < kallsyms_num_ 189 for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
259 off = kallsyms_expand_symbol(o 190 off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
260 ret = fn(data, namebuf, kallsy !! 191 ret = fn(data, namebuf, NULL, kallsyms_sym_address(i));
261 if (ret != 0) 192 if (ret != 0)
262 return ret; 193 return ret;
263 cond_resched(); <<
264 } <<
265 return 0; <<
266 } <<
267 <<
268 int kallsyms_on_each_match_symbol(int (*fn)(vo <<
269 const char * <<
270 { <<
271 int ret; <<
272 unsigned int i, start, end; <<
273 <<
274 ret = kallsyms_lookup_names(name, &sta <<
275 if (ret) <<
276 return 0; <<
277 <<
278 for (i = start; !ret && i <= end; i++) <<
279 ret = fn(data, kallsyms_sym_ad <<
280 cond_resched(); <<
281 } 194 }
282 !! 195 return module_kallsyms_on_each_symbol(fn, data);
283 return ret; <<
284 } 196 }
285 197
286 static unsigned long get_symbol_pos(unsigned l 198 static unsigned long get_symbol_pos(unsigned long addr,
287 unsigned l 199 unsigned long *symbolsize,
288 unsigned l 200 unsigned long *offset)
289 { 201 {
290 unsigned long symbol_start = 0, symbol 202 unsigned long symbol_start = 0, symbol_end = 0;
291 unsigned long i, low, high, mid; 203 unsigned long i, low, high, mid;
292 204
293 /* Do a binary search on the sorted ka !! 205 /* This kernel should never had been booted. */
>> 206 if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE))
>> 207 BUG_ON(!kallsyms_addresses);
>> 208 else
>> 209 BUG_ON(!kallsyms_offsets);
>> 210
>> 211 /* Do a binary search on the sorted kallsyms_addresses array. */
294 low = 0; 212 low = 0;
295 high = kallsyms_num_syms; 213 high = kallsyms_num_syms;
296 214
297 while (high - low > 1) { 215 while (high - low > 1) {
298 mid = low + (high - low) / 2; 216 mid = low + (high - low) / 2;
299 if (kallsyms_sym_address(mid) 217 if (kallsyms_sym_address(mid) <= addr)
300 low = mid; 218 low = mid;
301 else 219 else
302 high = mid; 220 high = mid;
303 } 221 }
304 222
305 /* 223 /*
306 * Search for the first aliased symbol 224 * Search for the first aliased symbol. Aliased
307 * symbols are symbols with the same a 225 * symbols are symbols with the same address.
308 */ 226 */
309 while (low && kallsyms_sym_address(low 227 while (low && kallsyms_sym_address(low-1) == kallsyms_sym_address(low))
310 --low; 228 --low;
311 229
312 symbol_start = kallsyms_sym_address(lo 230 symbol_start = kallsyms_sym_address(low);
313 231
314 /* Search for next non-aliased symbol. 232 /* Search for next non-aliased symbol. */
315 for (i = low + 1; i < kallsyms_num_sym 233 for (i = low + 1; i < kallsyms_num_syms; i++) {
316 if (kallsyms_sym_address(i) > 234 if (kallsyms_sym_address(i) > symbol_start) {
317 symbol_end = kallsyms_ 235 symbol_end = kallsyms_sym_address(i);
318 break; 236 break;
319 } 237 }
320 } 238 }
321 239
322 /* If we found no next symbol, we use 240 /* If we found no next symbol, we use the end of the section. */
323 if (!symbol_end) { 241 if (!symbol_end) {
324 if (is_kernel_inittext(addr)) 242 if (is_kernel_inittext(addr))
325 symbol_end = (unsigned 243 symbol_end = (unsigned long)_einittext;
326 else if (IS_ENABLED(CONFIG_KAL 244 else if (IS_ENABLED(CONFIG_KALLSYMS_ALL))
327 symbol_end = (unsigned 245 symbol_end = (unsigned long)_end;
328 else 246 else
329 symbol_end = (unsigned 247 symbol_end = (unsigned long)_etext;
330 } 248 }
331 249
332 if (symbolsize) 250 if (symbolsize)
333 *symbolsize = symbol_end - sym 251 *symbolsize = symbol_end - symbol_start;
334 if (offset) 252 if (offset)
335 *offset = addr - symbol_start; 253 *offset = addr - symbol_start;
336 254
337 return low; 255 return low;
338 } 256 }
339 257
340 /* 258 /*
341 * Lookup an address but don't bother to find 259 * Lookup an address but don't bother to find any names.
342 */ 260 */
343 int kallsyms_lookup_size_offset(unsigned long 261 int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize,
344 unsigned long 262 unsigned long *offset)
345 { 263 {
346 char namebuf[KSYM_NAME_LEN]; 264 char namebuf[KSYM_NAME_LEN];
347 265
348 if (is_ksym_addr(addr)) { 266 if (is_ksym_addr(addr)) {
349 get_symbol_pos(addr, symbolsiz 267 get_symbol_pos(addr, symbolsize, offset);
350 return 1; 268 return 1;
351 } 269 }
352 return !!module_address_lookup(addr, s !! 270 return !!module_address_lookup(addr, symbolsize, offset, NULL, namebuf) ||
353 !!__bpf_address_lookup(addr, sy 271 !!__bpf_address_lookup(addr, symbolsize, offset, namebuf);
354 } 272 }
355 273
356 static int kallsyms_lookup_buildid(unsigned lo !! 274 /*
357 unsigned long *symbols !! 275 * Lookup an address
358 unsigned long *offset, !! 276 * - modname is set to NULL if it's in the kernel.
359 const unsigned char ** !! 277 * - We guarantee that the returned name is valid until we reschedule even if.
>> 278 * It resides in a module.
>> 279 * - We also guarantee that modname will be valid until rescheduled.
>> 280 */
>> 281 const char *kallsyms_lookup(unsigned long addr,
>> 282 unsigned long *symbolsize,
>> 283 unsigned long *offset,
>> 284 char **modname, char *namebuf)
360 { 285 {
361 int ret; !! 286 const char *ret;
362 287
363 namebuf[KSYM_NAME_LEN - 1] = 0; 288 namebuf[KSYM_NAME_LEN - 1] = 0;
364 namebuf[0] = 0; 289 namebuf[0] = 0;
365 290
366 if (is_ksym_addr(addr)) { 291 if (is_ksym_addr(addr)) {
367 unsigned long pos; 292 unsigned long pos;
368 293
369 pos = get_symbol_pos(addr, sym 294 pos = get_symbol_pos(addr, symbolsize, offset);
370 /* Grab name */ 295 /* Grab name */
371 kallsyms_expand_symbol(get_sym 296 kallsyms_expand_symbol(get_symbol_offset(pos),
372 namebuf 297 namebuf, KSYM_NAME_LEN);
373 if (modname) 298 if (modname)
374 *modname = NULL; 299 *modname = NULL;
375 if (modbuildid) !! 300 return namebuf;
376 *modbuildid = NULL; <<
377 <<
378 return strlen(namebuf); <<
379 } 301 }
380 302
381 /* See if it's in a module or a BPF JI 303 /* See if it's in a module or a BPF JITed image. */
382 ret = module_address_lookup(addr, symb 304 ret = module_address_lookup(addr, symbolsize, offset,
383 modname, m !! 305 modname, namebuf);
384 if (!ret) 306 if (!ret)
385 ret = bpf_address_lookup(addr, 307 ret = bpf_address_lookup(addr, symbolsize,
386 offse 308 offset, modname, namebuf);
387 309
388 if (!ret) 310 if (!ret)
389 ret = ftrace_mod_address_looku 311 ret = ftrace_mod_address_lookup(addr, symbolsize,
390 312 offset, modname, namebuf);
391 <<
392 return ret; 313 return ret;
393 } 314 }
394 315
395 /* <<
396 * Lookup an address <<
397 * - modname is set to NULL if it's in the ker <<
398 * - We guarantee that the returned name is va <<
399 * It resides in a module. <<
400 * - We also guarantee that modname will be va <<
401 */ <<
402 const char *kallsyms_lookup(unsigned long addr <<
403 unsigned long *sym <<
404 unsigned long *off <<
405 char **modname, ch <<
406 { <<
407 int ret = kallsyms_lookup_buildid(addr <<
408 NULL <<
409 <<
410 if (!ret) <<
411 return NULL; <<
412 <<
413 return namebuf; <<
414 } <<
415 <<
416 int lookup_symbol_name(unsigned long addr, cha 316 int lookup_symbol_name(unsigned long addr, char *symname)
417 { 317 {
418 symname[0] = '\0'; 318 symname[0] = '\0';
419 symname[KSYM_NAME_LEN - 1] = '\0'; 319 symname[KSYM_NAME_LEN - 1] = '\0';
420 320
421 if (is_ksym_addr(addr)) { 321 if (is_ksym_addr(addr)) {
422 unsigned long pos; 322 unsigned long pos;
423 323
424 pos = get_symbol_pos(addr, NUL 324 pos = get_symbol_pos(addr, NULL, NULL);
425 /* Grab name */ 325 /* Grab name */
426 kallsyms_expand_symbol(get_sym 326 kallsyms_expand_symbol(get_symbol_offset(pos),
427 symname 327 symname, KSYM_NAME_LEN);
428 return 0; 328 return 0;
429 } 329 }
430 /* See if it's in a module. */ 330 /* See if it's in a module. */
431 return lookup_module_symbol_name(addr, 331 return lookup_module_symbol_name(addr, symname);
432 } 332 }
433 333
>> 334 int lookup_symbol_attrs(unsigned long addr, unsigned long *size,
>> 335 unsigned long *offset, char *modname, char *name)
>> 336 {
>> 337 name[0] = '\0';
>> 338 name[KSYM_NAME_LEN - 1] = '\0';
>> 339
>> 340 if (is_ksym_addr(addr)) {
>> 341 unsigned long pos;
>> 342
>> 343 pos = get_symbol_pos(addr, size, offset);
>> 344 /* Grab name */
>> 345 kallsyms_expand_symbol(get_symbol_offset(pos),
>> 346 name, KSYM_NAME_LEN);
>> 347 modname[0] = '\0';
>> 348 return 0;
>> 349 }
>> 350 /* See if it's in a module. */
>> 351 return lookup_module_symbol_attrs(addr, size, offset, modname, name);
>> 352 }
>> 353
434 /* Look up a kernel symbol and return it in a 354 /* Look up a kernel symbol and return it in a text buffer. */
435 static int __sprint_symbol(char *buffer, unsig 355 static int __sprint_symbol(char *buffer, unsigned long address,
436 int symbol_offset, !! 356 int symbol_offset, int add_offset)
437 { 357 {
438 char *modname; 358 char *modname;
439 const unsigned char *buildid; !! 359 const char *name;
440 unsigned long offset, size; 360 unsigned long offset, size;
441 int len; 361 int len;
442 362
443 address += symbol_offset; 363 address += symbol_offset;
444 len = kallsyms_lookup_buildid(address, !! 364 name = kallsyms_lookup(address, &size, &offset, &modname, buffer);
445 buffer) !! 365 if (!name)
446 if (!len) <<
447 return sprintf(buffer, "0x%lx" 366 return sprintf(buffer, "0x%lx", address - symbol_offset);
448 367
>> 368 if (name != buffer)
>> 369 strcpy(buffer, name);
>> 370 len = strlen(buffer);
449 offset -= symbol_offset; 371 offset -= symbol_offset;
450 372
451 if (add_offset) 373 if (add_offset)
452 len += sprintf(buffer + len, " 374 len += sprintf(buffer + len, "+%#lx/%#lx", offset, size);
453 375
454 if (modname) { !! 376 if (modname)
455 len += sprintf(buffer + len, " !! 377 len += sprintf(buffer + len, " [%s]", modname);
456 #if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) <<
457 if (add_buildid && buildid) { <<
458 /* build ID should mat <<
459 #if IS_ENABLED(CONFIG_MODULES) <<
460 static_assert(sizeof(t <<
461 #endif <<
462 len += sprintf(buffer <<
463 } <<
464 #endif <<
465 len += sprintf(buffer + len, " <<
466 } <<
467 378
468 return len; 379 return len;
469 } 380 }
470 381
471 /** 382 /**
472 * sprint_symbol - Look up a kernel symbol and 383 * sprint_symbol - Look up a kernel symbol and return it in a text buffer
473 * @buffer: buffer to be stored 384 * @buffer: buffer to be stored
474 * @address: address to lookup 385 * @address: address to lookup
475 * 386 *
476 * This function looks up a kernel symbol with 387 * This function looks up a kernel symbol with @address and stores its name,
477 * offset, size and module name to @buffer if 388 * offset, size and module name to @buffer if possible. If no symbol was found,
478 * just saves its @address as is. 389 * just saves its @address as is.
479 * 390 *
480 * This function returns the number of bytes s 391 * This function returns the number of bytes stored in @buffer.
481 */ 392 */
482 int sprint_symbol(char *buffer, unsigned long 393 int sprint_symbol(char *buffer, unsigned long address)
483 { 394 {
484 return __sprint_symbol(buffer, address !! 395 return __sprint_symbol(buffer, address, 0, 1);
485 } 396 }
486 EXPORT_SYMBOL_GPL(sprint_symbol); 397 EXPORT_SYMBOL_GPL(sprint_symbol);
487 398
488 /** 399 /**
489 * sprint_symbol_build_id - Look up a kernel s <<
490 * @buffer: buffer to be stored <<
491 * @address: address to lookup <<
492 * <<
493 * This function looks up a kernel symbol with <<
494 * offset, size, module name and module build <<
495 * symbol was found, just saves its @address a <<
496 * <<
497 * This function returns the number of bytes s <<
498 */ <<
499 int sprint_symbol_build_id(char *buffer, unsig <<
500 { <<
501 return __sprint_symbol(buffer, address <<
502 } <<
503 EXPORT_SYMBOL_GPL(sprint_symbol_build_id); <<
504 <<
505 /** <<
506 * sprint_symbol_no_offset - Look up a kernel 400 * sprint_symbol_no_offset - Look up a kernel symbol and return it in a text buffer
507 * @buffer: buffer to be stored 401 * @buffer: buffer to be stored
508 * @address: address to lookup 402 * @address: address to lookup
509 * 403 *
510 * This function looks up a kernel symbol with 404 * This function looks up a kernel symbol with @address and stores its name
511 * and module name to @buffer if possible. If 405 * and module name to @buffer if possible. If no symbol was found, just saves
512 * its @address as is. 406 * its @address as is.
513 * 407 *
514 * This function returns the number of bytes s 408 * This function returns the number of bytes stored in @buffer.
515 */ 409 */
516 int sprint_symbol_no_offset(char *buffer, unsi 410 int sprint_symbol_no_offset(char *buffer, unsigned long address)
517 { 411 {
518 return __sprint_symbol(buffer, address !! 412 return __sprint_symbol(buffer, address, 0, 0);
519 } 413 }
520 EXPORT_SYMBOL_GPL(sprint_symbol_no_offset); 414 EXPORT_SYMBOL_GPL(sprint_symbol_no_offset);
521 415
522 /** 416 /**
523 * sprint_backtrace - Look up a backtrace symb 417 * sprint_backtrace - Look up a backtrace symbol and return it in a text buffer
524 * @buffer: buffer to be stored 418 * @buffer: buffer to be stored
525 * @address: address to lookup 419 * @address: address to lookup
526 * 420 *
527 * This function is for stack backtrace and do 421 * This function is for stack backtrace and does the same thing as
528 * sprint_symbol() but with modified/decreased 422 * sprint_symbol() but with modified/decreased @address. If there is a
529 * tail-call to the function marked "noreturn" 423 * tail-call to the function marked "noreturn", gcc optimized out code after
530 * the call so that the stack-saved return add 424 * the call so that the stack-saved return address could point outside of the
531 * caller. This function ensures that kallsyms 425 * caller. This function ensures that kallsyms will find the original caller
532 * by decreasing @address. 426 * by decreasing @address.
533 * 427 *
534 * This function returns the number of bytes s 428 * This function returns the number of bytes stored in @buffer.
535 */ 429 */
536 int sprint_backtrace(char *buffer, unsigned lo 430 int sprint_backtrace(char *buffer, unsigned long address)
537 { 431 {
538 return __sprint_symbol(buffer, address !! 432 return __sprint_symbol(buffer, address, -1, 1);
539 } <<
540 <<
541 /** <<
542 * sprint_backtrace_build_id - Look up a backt <<
543 * @buffer: buffer to be stored <<
544 * @address: address to lookup <<
545 * <<
546 * This function is for stack backtrace and do <<
547 * sprint_symbol() but with modified/decreased <<
548 * tail-call to the function marked "noreturn" <<
549 * the call so that the stack-saved return add <<
550 * caller. This function ensures that kallsyms <<
551 * by decreasing @address. This function also <<
552 * the @buffer if @address is within a kernel <<
553 * <<
554 * This function returns the number of bytes s <<
555 */ <<
556 int sprint_backtrace_build_id(char *buffer, un <<
557 { <<
558 return __sprint_symbol(buffer, address <<
559 } 433 }
560 434
561 /* To avoid using get_symbol_offset for every 435 /* To avoid using get_symbol_offset for every symbol, we carry prefix along. */
562 struct kallsym_iter { 436 struct kallsym_iter {
563 loff_t pos; 437 loff_t pos;
>> 438 loff_t pos_arch_end;
564 loff_t pos_mod_end; 439 loff_t pos_mod_end;
565 loff_t pos_ftrace_mod_end; 440 loff_t pos_ftrace_mod_end;
566 loff_t pos_bpf_end; 441 loff_t pos_bpf_end;
567 unsigned long value; 442 unsigned long value;
568 unsigned int nameoff; /* If iterating 443 unsigned int nameoff; /* If iterating in core kernel symbols. */
569 char type; 444 char type;
570 char name[KSYM_NAME_LEN]; 445 char name[KSYM_NAME_LEN];
571 char module_name[MODULE_NAME_LEN]; 446 char module_name[MODULE_NAME_LEN];
572 int exported; 447 int exported;
573 int show_value; 448 int show_value;
574 }; 449 };
575 450
>> 451 int __weak arch_get_kallsym(unsigned int symnum, unsigned long *value,
>> 452 char *type, char *name)
>> 453 {
>> 454 return -EINVAL;
>> 455 }
>> 456
>> 457 static int get_ksymbol_arch(struct kallsym_iter *iter)
>> 458 {
>> 459 int ret = arch_get_kallsym(iter->pos - kallsyms_num_syms,
>> 460 &iter->value, &iter->type,
>> 461 iter->name);
>> 462
>> 463 if (ret < 0) {
>> 464 iter->pos_arch_end = iter->pos;
>> 465 return 0;
>> 466 }
>> 467
>> 468 return 1;
>> 469 }
>> 470
576 static int get_ksymbol_mod(struct kallsym_iter 471 static int get_ksymbol_mod(struct kallsym_iter *iter)
577 { 472 {
578 int ret = module_get_kallsym(iter->pos !! 473 int ret = module_get_kallsym(iter->pos - iter->pos_arch_end,
579 &iter->va 474 &iter->value, &iter->type,
580 iter->nam 475 iter->name, iter->module_name,
581 &iter->ex 476 &iter->exported);
582 if (ret < 0) { 477 if (ret < 0) {
583 iter->pos_mod_end = iter->pos; 478 iter->pos_mod_end = iter->pos;
584 return 0; 479 return 0;
585 } 480 }
586 481
587 return 1; 482 return 1;
588 } 483 }
589 484
590 /* 485 /*
591 * ftrace_mod_get_kallsym() may also get symbo 486 * ftrace_mod_get_kallsym() may also get symbols for pages allocated for ftrace
592 * purposes. In that case "__builtin__ftrace" 487 * purposes. In that case "__builtin__ftrace" is used as a module name, even
593 * though "__builtin__ftrace" is not a module. 488 * though "__builtin__ftrace" is not a module.
594 */ 489 */
595 static int get_ksymbol_ftrace_mod(struct kalls 490 static int get_ksymbol_ftrace_mod(struct kallsym_iter *iter)
596 { 491 {
597 int ret = ftrace_mod_get_kallsym(iter- 492 int ret = ftrace_mod_get_kallsym(iter->pos - iter->pos_mod_end,
598 &iter 493 &iter->value, &iter->type,
599 iter- 494 iter->name, iter->module_name,
600 &iter 495 &iter->exported);
601 if (ret < 0) { 496 if (ret < 0) {
602 iter->pos_ftrace_mod_end = ite 497 iter->pos_ftrace_mod_end = iter->pos;
603 return 0; 498 return 0;
604 } 499 }
605 500
606 return 1; 501 return 1;
607 } 502 }
608 503
609 static int get_ksymbol_bpf(struct kallsym_iter 504 static int get_ksymbol_bpf(struct kallsym_iter *iter)
610 { 505 {
611 int ret; 506 int ret;
612 507
613 strscpy(iter->module_name, "bpf", MODU !! 508 strlcpy(iter->module_name, "bpf", MODULE_NAME_LEN);
614 iter->exported = 0; 509 iter->exported = 0;
615 ret = bpf_get_kallsym(iter->pos - iter 510 ret = bpf_get_kallsym(iter->pos - iter->pos_ftrace_mod_end,
616 &iter->value, &i 511 &iter->value, &iter->type,
617 iter->name); 512 iter->name);
618 if (ret < 0) { 513 if (ret < 0) {
619 iter->pos_bpf_end = iter->pos; 514 iter->pos_bpf_end = iter->pos;
620 return 0; 515 return 0;
621 } 516 }
622 517
623 return 1; 518 return 1;
624 } 519 }
625 520
626 /* 521 /*
627 * This uses "__builtin__kprobes" as a module 522 * This uses "__builtin__kprobes" as a module name for symbols for pages
628 * allocated for kprobes' purposes, even thoug 523 * allocated for kprobes' purposes, even though "__builtin__kprobes" is not a
629 * module. 524 * module.
630 */ 525 */
631 static int get_ksymbol_kprobe(struct kallsym_i 526 static int get_ksymbol_kprobe(struct kallsym_iter *iter)
632 { 527 {
633 strscpy(iter->module_name, "__builtin_ !! 528 strlcpy(iter->module_name, "__builtin__kprobes", MODULE_NAME_LEN);
634 iter->exported = 0; 529 iter->exported = 0;
635 return kprobe_get_kallsym(iter->pos - 530 return kprobe_get_kallsym(iter->pos - iter->pos_bpf_end,
636 &iter->value 531 &iter->value, &iter->type,
637 iter->name) 532 iter->name) < 0 ? 0 : 1;
638 } 533 }
639 534
640 /* Returns space to next name. */ 535 /* Returns space to next name. */
641 static unsigned long get_ksymbol_core(struct k 536 static unsigned long get_ksymbol_core(struct kallsym_iter *iter)
642 { 537 {
643 unsigned off = iter->nameoff; 538 unsigned off = iter->nameoff;
644 539
645 iter->module_name[0] = '\0'; 540 iter->module_name[0] = '\0';
646 iter->value = kallsyms_sym_address(ite 541 iter->value = kallsyms_sym_address(iter->pos);
647 542
648 iter->type = kallsyms_get_symbol_type( 543 iter->type = kallsyms_get_symbol_type(off);
649 544
650 off = kallsyms_expand_symbol(off, iter 545 off = kallsyms_expand_symbol(off, iter->name, ARRAY_SIZE(iter->name));
651 546
652 return off - iter->nameoff; 547 return off - iter->nameoff;
653 } 548 }
654 549
655 static void reset_iter(struct kallsym_iter *it 550 static void reset_iter(struct kallsym_iter *iter, loff_t new_pos)
656 { 551 {
657 iter->name[0] = '\0'; 552 iter->name[0] = '\0';
658 iter->nameoff = get_symbol_offset(new_ 553 iter->nameoff = get_symbol_offset(new_pos);
659 iter->pos = new_pos; 554 iter->pos = new_pos;
660 if (new_pos == 0) { 555 if (new_pos == 0) {
>> 556 iter->pos_arch_end = 0;
661 iter->pos_mod_end = 0; 557 iter->pos_mod_end = 0;
662 iter->pos_ftrace_mod_end = 0; 558 iter->pos_ftrace_mod_end = 0;
663 iter->pos_bpf_end = 0; 559 iter->pos_bpf_end = 0;
664 } 560 }
665 } 561 }
666 562
667 /* 563 /*
668 * The end position (last + 1) of each additio 564 * The end position (last + 1) of each additional kallsyms section is recorded
669 * in iter->pos_..._end as each section is add 565 * in iter->pos_..._end as each section is added, and so can be used to
670 * determine which get_ksymbol_...() function 566 * determine which get_ksymbol_...() function to call next.
671 */ 567 */
672 static int update_iter_mod(struct kallsym_iter 568 static int update_iter_mod(struct kallsym_iter *iter, loff_t pos)
673 { 569 {
674 iter->pos = pos; 570 iter->pos = pos;
675 571
>> 572 if ((!iter->pos_arch_end || iter->pos_arch_end > pos) &&
>> 573 get_ksymbol_arch(iter))
>> 574 return 1;
>> 575
676 if ((!iter->pos_mod_end || iter->pos_m 576 if ((!iter->pos_mod_end || iter->pos_mod_end > pos) &&
677 get_ksymbol_mod(iter)) 577 get_ksymbol_mod(iter))
678 return 1; 578 return 1;
679 579
680 if ((!iter->pos_ftrace_mod_end || iter 580 if ((!iter->pos_ftrace_mod_end || iter->pos_ftrace_mod_end > pos) &&
681 get_ksymbol_ftrace_mod(iter)) 581 get_ksymbol_ftrace_mod(iter))
682 return 1; 582 return 1;
683 583
684 if ((!iter->pos_bpf_end || iter->pos_b 584 if ((!iter->pos_bpf_end || iter->pos_bpf_end > pos) &&
685 get_ksymbol_bpf(iter)) 585 get_ksymbol_bpf(iter))
686 return 1; 586 return 1;
687 587
688 return get_ksymbol_kprobe(iter); 588 return get_ksymbol_kprobe(iter);
689 } 589 }
690 590
691 /* Returns false if pos at or past end of file 591 /* Returns false if pos at or past end of file. */
692 static int update_iter(struct kallsym_iter *it 592 static int update_iter(struct kallsym_iter *iter, loff_t pos)
693 { 593 {
694 /* Module symbols can be accessed rand 594 /* Module symbols can be accessed randomly. */
695 if (pos >= kallsyms_num_syms) 595 if (pos >= kallsyms_num_syms)
696 return update_iter_mod(iter, p 596 return update_iter_mod(iter, pos);
697 597
698 /* If we're not on the desired positio 598 /* If we're not on the desired position, reset to new position. */
699 if (pos != iter->pos) 599 if (pos != iter->pos)
700 reset_iter(iter, pos); 600 reset_iter(iter, pos);
701 601
702 iter->nameoff += get_ksymbol_core(iter 602 iter->nameoff += get_ksymbol_core(iter);
703 iter->pos++; 603 iter->pos++;
704 604
705 return 1; 605 return 1;
706 } 606 }
707 607
708 static void *s_next(struct seq_file *m, void * 608 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
709 { 609 {
710 (*pos)++; 610 (*pos)++;
711 611
712 if (!update_iter(m->private, *pos)) 612 if (!update_iter(m->private, *pos))
713 return NULL; 613 return NULL;
714 return p; 614 return p;
715 } 615 }
716 616
717 static void *s_start(struct seq_file *m, loff_ 617 static void *s_start(struct seq_file *m, loff_t *pos)
718 { 618 {
719 if (!update_iter(m->private, *pos)) 619 if (!update_iter(m->private, *pos))
720 return NULL; 620 return NULL;
721 return m->private; 621 return m->private;
722 } 622 }
723 623
724 static void s_stop(struct seq_file *m, void *p 624 static void s_stop(struct seq_file *m, void *p)
725 { 625 {
726 } 626 }
727 627
728 static int s_show(struct seq_file *m, void *p) 628 static int s_show(struct seq_file *m, void *p)
729 { 629 {
730 void *value; 630 void *value;
731 struct kallsym_iter *iter = m->private 631 struct kallsym_iter *iter = m->private;
732 632
733 /* Some debugging symbols have no name 633 /* Some debugging symbols have no name. Ignore them. */
734 if (!iter->name[0]) 634 if (!iter->name[0])
735 return 0; 635 return 0;
736 636
737 value = iter->show_value ? (void *)ite 637 value = iter->show_value ? (void *)iter->value : NULL;
738 638
739 if (iter->module_name[0]) { 639 if (iter->module_name[0]) {
740 char type; 640 char type;
741 641
742 /* 642 /*
743 * Label it "global" if it is 643 * Label it "global" if it is exported,
744 * "local" if not exported. 644 * "local" if not exported.
745 */ 645 */
746 type = iter->exported ? touppe 646 type = iter->exported ? toupper(iter->type) :
747 tolowe 647 tolower(iter->type);
748 seq_printf(m, "%px %c %s\t[%s] 648 seq_printf(m, "%px %c %s\t[%s]\n", value,
749 type, iter->name, i 649 type, iter->name, iter->module_name);
750 } else 650 } else
751 seq_printf(m, "%px %c %s\n", v 651 seq_printf(m, "%px %c %s\n", value,
752 iter->type, iter->n 652 iter->type, iter->name);
753 return 0; 653 return 0;
754 } 654 }
755 655
756 static const struct seq_operations kallsyms_op 656 static const struct seq_operations kallsyms_op = {
757 .start = s_start, 657 .start = s_start,
758 .next = s_next, 658 .next = s_next,
759 .stop = s_stop, 659 .stop = s_stop,
760 .show = s_show 660 .show = s_show
761 }; 661 };
762 662
763 #ifdef CONFIG_BPF_SYSCALL !! 663 static inline int kallsyms_for_perf(void)
764 <<
765 struct bpf_iter__ksym { <<
766 __bpf_md_ptr(struct bpf_iter_meta *, m <<
767 __bpf_md_ptr(struct kallsym_iter *, ks <<
768 }; <<
769 <<
770 static int ksym_prog_seq_show(struct seq_file <<
771 { <<
772 struct bpf_iter__ksym ctx; <<
773 struct bpf_iter_meta meta; <<
774 struct bpf_prog *prog; <<
775 <<
776 meta.seq = m; <<
777 prog = bpf_iter_get_info(&meta, in_sto <<
778 if (!prog) <<
779 return 0; <<
780 <<
781 ctx.meta = &meta; <<
782 ctx.ksym = m ? m->private : NULL; <<
783 return bpf_iter_run_prog(prog, &ctx); <<
784 } <<
785 <<
786 static int bpf_iter_ksym_seq_show(struct seq_f <<
787 { <<
788 return ksym_prog_seq_show(m, false); <<
789 } <<
790 <<
791 static void bpf_iter_ksym_seq_stop(struct seq_ <<
792 { <<
793 if (!p) <<
794 (void) ksym_prog_seq_show(m, t <<
795 else <<
796 s_stop(m, p); <<
797 } <<
798 <<
799 static const struct seq_operations bpf_iter_ks <<
800 .start = s_start, <<
801 .next = s_next, <<
802 .stop = bpf_iter_ksym_seq_stop, <<
803 .show = bpf_iter_ksym_seq_show, <<
804 }; <<
805 <<
806 static int bpf_iter_ksym_init(void *priv_data, <<
807 { 664 {
808 struct kallsym_iter *iter = priv_data; !! 665 #ifdef CONFIG_PERF_EVENTS
809 !! 666 extern int sysctl_perf_event_paranoid;
810 reset_iter(iter, 0); !! 667 if (sysctl_perf_event_paranoid <= 1)
811 !! 668 return 1;
812 /* cache here as in kallsyms_open() ca !! 669 #endif
813 * credentials to tell BPF iterators i <<
814 */ <<
815 iter->show_value = kallsyms_show_value <<
816 <<
817 return 0; 670 return 0;
818 } 671 }
819 672
820 DEFINE_BPF_ITER_FUNC(ksym, struct bpf_iter_met !! 673 /*
821 !! 674 * We show kallsyms information even to normal users if we've enabled
822 static const struct bpf_iter_seq_info ksym_ite !! 675 * kernel profiling and are explicitly not paranoid (so kptr_restrict
823 .seq_ops = &bpf_iter_ks !! 676 * is clear, and sysctl_perf_event_paranoid isn't set).
824 .init_seq_private = bpf_iter_ksy !! 677 *
825 .fini_seq_private = NULL, !! 678 * Otherwise, require CAP_SYSLOG (assuming kptr_restrict isn't set to
826 .seq_priv_size = sizeof(struc !! 679 * block even that).
827 }; !! 680 */
828 !! 681 bool kallsyms_show_value(const struct cred *cred)
829 static struct bpf_iter_reg ksym_iter_reg_info <<
830 .target = "ksym", <<
831 .feature = BPF_ITER_RES <<
832 .ctx_arg_info_size = 1, <<
833 .ctx_arg_info = { <<
834 { offsetof(struct bpf_iter__ks <<
835 PTR_TO_BTF_ID_OR_NULL }, <<
836 }, <<
837 .seq_info = &ksym_iter_s <<
838 }; <<
839 <<
840 BTF_ID_LIST(btf_ksym_iter_id) <<
841 BTF_ID(struct, kallsym_iter) <<
842 <<
843 static int __init bpf_ksym_iter_register(void) <<
844 { 682 {
845 ksym_iter_reg_info.ctx_arg_info[0].btf !! 683 switch (kptr_restrict) {
846 return bpf_iter_reg_target(&ksym_iter_ !! 684 case 0:
>> 685 if (kallsyms_for_perf())
>> 686 return true;
>> 687 fallthrough;
>> 688 case 1:
>> 689 if (security_capable(cred, &init_user_ns, CAP_SYSLOG,
>> 690 CAP_OPT_NOAUDIT) == 0)
>> 691 return true;
>> 692 fallthrough;
>> 693 default:
>> 694 return false;
>> 695 }
847 } 696 }
848 <<
849 late_initcall(bpf_ksym_iter_register); <<
850 <<
851 #endif /* CONFIG_BPF_SYSCALL */ <<
852 697
853 static int kallsyms_open(struct inode *inode, 698 static int kallsyms_open(struct inode *inode, struct file *file)
854 { 699 {
855 /* 700 /*
856 * We keep iterator in m->private, sin 701 * We keep iterator in m->private, since normal case is to
857 * s_start from where we left off, so 702 * s_start from where we left off, so we avoid doing
858 * using get_symbol_offset for every s 703 * using get_symbol_offset for every symbol.
859 */ 704 */
860 struct kallsym_iter *iter; 705 struct kallsym_iter *iter;
861 iter = __seq_open_private(file, &kalls 706 iter = __seq_open_private(file, &kallsyms_op, sizeof(*iter));
862 if (!iter) 707 if (!iter)
863 return -ENOMEM; 708 return -ENOMEM;
864 reset_iter(iter, 0); 709 reset_iter(iter, 0);
865 710
866 /* 711 /*
867 * Instead of checking this on every s 712 * Instead of checking this on every s_show() call, cache
868 * the result here at open time. 713 * the result here at open time.
869 */ 714 */
870 iter->show_value = kallsyms_show_value 715 iter->show_value = kallsyms_show_value(file->f_cred);
871 return 0; 716 return 0;
872 } 717 }
873 718
874 #ifdef CONFIG_KGDB_KDB 719 #ifdef CONFIG_KGDB_KDB
875 const char *kdb_walk_kallsyms(loff_t *pos) 720 const char *kdb_walk_kallsyms(loff_t *pos)
876 { 721 {
877 static struct kallsym_iter kdb_walk_ka 722 static struct kallsym_iter kdb_walk_kallsyms_iter;
878 if (*pos == 0) { 723 if (*pos == 0) {
879 memset(&kdb_walk_kallsyms_iter 724 memset(&kdb_walk_kallsyms_iter, 0,
880 sizeof(kdb_walk_kallsym 725 sizeof(kdb_walk_kallsyms_iter));
881 reset_iter(&kdb_walk_kallsyms_ 726 reset_iter(&kdb_walk_kallsyms_iter, 0);
882 } 727 }
883 while (1) { 728 while (1) {
884 if (!update_iter(&kdb_walk_kal 729 if (!update_iter(&kdb_walk_kallsyms_iter, *pos))
885 return NULL; 730 return NULL;
886 ++*pos; 731 ++*pos;
887 /* Some debugging symbols have 732 /* Some debugging symbols have no name. Ignore them. */
888 if (kdb_walk_kallsyms_iter.nam 733 if (kdb_walk_kallsyms_iter.name[0])
889 return kdb_walk_kallsy 734 return kdb_walk_kallsyms_iter.name;
890 } 735 }
891 } 736 }
892 #endif /* CONFIG_KGDB_KDB */ 737 #endif /* CONFIG_KGDB_KDB */
893 738
894 static const struct proc_ops kallsyms_proc_ops 739 static const struct proc_ops kallsyms_proc_ops = {
895 .proc_open = kallsyms_open, 740 .proc_open = kallsyms_open,
896 .proc_read = seq_read, 741 .proc_read = seq_read,
897 .proc_lseek = seq_lseek, 742 .proc_lseek = seq_lseek,
898 .proc_release = seq_release_private, 743 .proc_release = seq_release_private,
899 }; 744 };
900 745
901 static int __init kallsyms_init(void) 746 static int __init kallsyms_init(void)
902 { 747 {
903 proc_create("kallsyms", 0444, NULL, &k 748 proc_create("kallsyms", 0444, NULL, &kallsyms_proc_ops);
904 return 0; 749 return 0;
905 } 750 }
906 device_initcall(kallsyms_init); 751 device_initcall(kallsyms_init);
907 752
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