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