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 if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE))
>> 152 return kallsyms_addresses[idx];
>> 153
151 /* values are unsigned offsets if --ab 154 /* values are unsigned offsets if --absolute-percpu is not in effect */
152 if (!IS_ENABLED(CONFIG_KALLSYMS_ABSOLU 155 if (!IS_ENABLED(CONFIG_KALLSYMS_ABSOLUTE_PERCPU))
153 return kallsyms_relative_base 156 return kallsyms_relative_base + (u32)kallsyms_offsets[idx];
154 157
155 /* ...otherwise, positive offsets are 158 /* ...otherwise, positive offsets are absolute values */
156 if (kallsyms_offsets[idx] >= 0) 159 if (kallsyms_offsets[idx] >= 0)
157 return kallsyms_offsets[idx]; 160 return kallsyms_offsets[idx];
158 161
159 /* ...and negative offsets are relativ 162 /* ...and negative offsets are relative to kallsyms_relative_base - 1 */
160 return kallsyms_relative_base - 1 - ka 163 return kallsyms_relative_base - 1 - kallsyms_offsets[idx];
161 } 164 }
162 165
>> 166 static void cleanup_symbol_name(char *s)
>> 167 {
>> 168 char *res;
>> 169
>> 170 if (!IS_ENABLED(CONFIG_LTO_CLANG))
>> 171 return;
>> 172
>> 173 /*
>> 174 * LLVM appends various suffixes for local functions and variables that
>> 175 * must be promoted to global scope as part of LTO. This can break
>> 176 * hooking of static functions with kprobes. '.' is not a valid
>> 177 * character in an identifier in C. Suffixes only in LLVM LTO observed:
>> 178 * - foo.llvm.[0-9a-f]+
>> 179 */
>> 180 res = strstr(s, ".llvm.");
>> 181 if (res)
>> 182 *res = '\0';
>> 183
>> 184 return;
>> 185 }
>> 186
>> 187 static int compare_symbol_name(const char *name, char *namebuf)
>> 188 {
>> 189 /* The kallsyms_seqs_of_names is sorted based on names after
>> 190 * cleanup_symbol_name() (see scripts/kallsyms.c) if clang lto is enabled.
>> 191 * To ensure correct bisection in kallsyms_lookup_names(), do
>> 192 * cleanup_symbol_name(namebuf) before comparing name and namebuf.
>> 193 */
>> 194 cleanup_symbol_name(namebuf);
>> 195 return strcmp(name, namebuf);
>> 196 }
>> 197
163 static unsigned int get_symbol_seq(int index) 198 static unsigned int get_symbol_seq(int index)
164 { 199 {
165 unsigned int i, seq = 0; 200 unsigned int i, seq = 0;
166 201
167 for (i = 0; i < 3; i++) 202 for (i = 0; i < 3; i++)
168 seq = (seq << 8) | kallsyms_se 203 seq = (seq << 8) | kallsyms_seqs_of_names[3 * index + i];
169 204
170 return seq; 205 return seq;
171 } 206 }
172 207
173 static int kallsyms_lookup_names(const char *n 208 static int kallsyms_lookup_names(const char *name,
174 unsigned int 209 unsigned int *start,
175 unsigned int 210 unsigned int *end)
176 { 211 {
177 int ret; 212 int ret;
178 int low, mid, high; 213 int low, mid, high;
179 unsigned int seq, off; 214 unsigned int seq, off;
180 char namebuf[KSYM_NAME_LEN]; 215 char namebuf[KSYM_NAME_LEN];
181 216
182 low = 0; 217 low = 0;
183 high = kallsyms_num_syms - 1; 218 high = kallsyms_num_syms - 1;
184 219
185 while (low <= high) { 220 while (low <= high) {
186 mid = low + (high - low) / 2; 221 mid = low + (high - low) / 2;
187 seq = get_symbol_seq(mid); 222 seq = get_symbol_seq(mid);
188 off = get_symbol_offset(seq); 223 off = get_symbol_offset(seq);
189 kallsyms_expand_symbol(off, na 224 kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
190 ret = strcmp(name, namebuf); !! 225 ret = compare_symbol_name(name, namebuf);
191 if (ret > 0) 226 if (ret > 0)
192 low = mid + 1; 227 low = mid + 1;
193 else if (ret < 0) 228 else if (ret < 0)
194 high = mid - 1; 229 high = mid - 1;
195 else 230 else
196 break; 231 break;
197 } 232 }
198 233
199 if (low > high) 234 if (low > high)
200 return -ESRCH; 235 return -ESRCH;
201 236
202 low = mid; 237 low = mid;
203 while (low) { 238 while (low) {
204 seq = get_symbol_seq(low - 1); 239 seq = get_symbol_seq(low - 1);
205 off = get_symbol_offset(seq); 240 off = get_symbol_offset(seq);
206 kallsyms_expand_symbol(off, na 241 kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
207 if (strcmp(name, namebuf)) !! 242 if (compare_symbol_name(name, namebuf))
208 break; 243 break;
209 low--; 244 low--;
210 } 245 }
211 *start = low; 246 *start = low;
212 247
213 if (end) { 248 if (end) {
214 high = mid; 249 high = mid;
215 while (high < kallsyms_num_sym 250 while (high < kallsyms_num_syms - 1) {
216 seq = get_symbol_seq(h 251 seq = get_symbol_seq(high + 1);
217 off = get_symbol_offse 252 off = get_symbol_offset(seq);
218 kallsyms_expand_symbol 253 kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
219 if (strcmp(name, nameb !! 254 if (compare_symbol_name(name, namebuf))
220 break; 255 break;
221 high++; 256 high++;
222 } 257 }
223 *end = high; 258 *end = high;
224 } 259 }
225 260
226 return 0; 261 return 0;
227 } 262 }
228 263
229 /* Lookup the address for this symbol. Returns 264 /* Lookup the address for this symbol. Returns 0 if not found. */
230 unsigned long kallsyms_lookup_name(const char 265 unsigned long kallsyms_lookup_name(const char *name)
231 { 266 {
232 int ret; 267 int ret;
233 unsigned int i; 268 unsigned int i;
234 269
235 /* Skip the search for empty string. * 270 /* Skip the search for empty string. */
236 if (!*name) 271 if (!*name)
237 return 0; 272 return 0;
238 273
239 ret = kallsyms_lookup_names(name, &i, 274 ret = kallsyms_lookup_names(name, &i, NULL);
240 if (!ret) 275 if (!ret)
241 return kallsyms_sym_address(ge 276 return kallsyms_sym_address(get_symbol_seq(i));
242 277
243 return module_kallsyms_lookup_name(nam 278 return module_kallsyms_lookup_name(name);
244 } 279 }
245 280
246 /* 281 /*
247 * Iterate over all symbols in vmlinux. For s 282 * Iterate over all symbols in vmlinux. For symbols from modules use
248 * module_kallsyms_on_each_symbol instead. 283 * module_kallsyms_on_each_symbol instead.
249 */ 284 */
250 int kallsyms_on_each_symbol(int (*fn)(void *, 285 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, unsigned long),
251 void *data) 286 void *data)
252 { 287 {
253 char namebuf[KSYM_NAME_LEN]; 288 char namebuf[KSYM_NAME_LEN];
254 unsigned long i; 289 unsigned long i;
255 unsigned int off; 290 unsigned int off;
256 int ret; 291 int ret;
257 292
258 for (i = 0, off = 0; i < kallsyms_num_ 293 for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
259 off = kallsyms_expand_symbol(o 294 off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
260 ret = fn(data, namebuf, kallsy 295 ret = fn(data, namebuf, kallsyms_sym_address(i));
261 if (ret != 0) 296 if (ret != 0)
262 return ret; 297 return ret;
263 cond_resched(); 298 cond_resched();
264 } 299 }
265 return 0; 300 return 0;
266 } 301 }
267 302
268 int kallsyms_on_each_match_symbol(int (*fn)(vo 303 int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long),
269 const char * 304 const char *name, void *data)
270 { 305 {
271 int ret; 306 int ret;
272 unsigned int i, start, end; 307 unsigned int i, start, end;
273 308
274 ret = kallsyms_lookup_names(name, &sta 309 ret = kallsyms_lookup_names(name, &start, &end);
275 if (ret) 310 if (ret)
276 return 0; 311 return 0;
277 312
278 for (i = start; !ret && i <= end; i++) 313 for (i = start; !ret && i <= end; i++) {
279 ret = fn(data, kallsyms_sym_ad 314 ret = fn(data, kallsyms_sym_address(get_symbol_seq(i)));
280 cond_resched(); 315 cond_resched();
281 } 316 }
282 317
283 return ret; 318 return ret;
284 } 319 }
285 320
286 static unsigned long get_symbol_pos(unsigned l 321 static unsigned long get_symbol_pos(unsigned long addr,
287 unsigned l 322 unsigned long *symbolsize,
288 unsigned l 323 unsigned long *offset)
289 { 324 {
290 unsigned long symbol_start = 0, symbol 325 unsigned long symbol_start = 0, symbol_end = 0;
291 unsigned long i, low, high, mid; 326 unsigned long i, low, high, mid;
292 327
293 /* Do a binary search on the sorted ka !! 328 /* This kernel should never had been booted. */
>> 329 if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE))
>> 330 BUG_ON(!kallsyms_addresses);
>> 331 else
>> 332 BUG_ON(!kallsyms_offsets);
>> 333
>> 334 /* Do a binary search on the sorted kallsyms_addresses array. */
294 low = 0; 335 low = 0;
295 high = kallsyms_num_syms; 336 high = kallsyms_num_syms;
296 337
297 while (high - low > 1) { 338 while (high - low > 1) {
298 mid = low + (high - low) / 2; 339 mid = low + (high - low) / 2;
299 if (kallsyms_sym_address(mid) 340 if (kallsyms_sym_address(mid) <= addr)
300 low = mid; 341 low = mid;
301 else 342 else
302 high = mid; 343 high = mid;
303 } 344 }
304 345
305 /* 346 /*
306 * Search for the first aliased symbol 347 * Search for the first aliased symbol. Aliased
307 * symbols are symbols with the same a 348 * symbols are symbols with the same address.
308 */ 349 */
309 while (low && kallsyms_sym_address(low 350 while (low && kallsyms_sym_address(low-1) == kallsyms_sym_address(low))
310 --low; 351 --low;
311 352
312 symbol_start = kallsyms_sym_address(lo 353 symbol_start = kallsyms_sym_address(low);
313 354
314 /* Search for next non-aliased symbol. 355 /* Search for next non-aliased symbol. */
315 for (i = low + 1; i < kallsyms_num_sym 356 for (i = low + 1; i < kallsyms_num_syms; i++) {
316 if (kallsyms_sym_address(i) > 357 if (kallsyms_sym_address(i) > symbol_start) {
317 symbol_end = kallsyms_ 358 symbol_end = kallsyms_sym_address(i);
318 break; 359 break;
319 } 360 }
320 } 361 }
321 362
322 /* If we found no next symbol, we use 363 /* If we found no next symbol, we use the end of the section. */
323 if (!symbol_end) { 364 if (!symbol_end) {
324 if (is_kernel_inittext(addr)) 365 if (is_kernel_inittext(addr))
325 symbol_end = (unsigned 366 symbol_end = (unsigned long)_einittext;
326 else if (IS_ENABLED(CONFIG_KAL 367 else if (IS_ENABLED(CONFIG_KALLSYMS_ALL))
327 symbol_end = (unsigned 368 symbol_end = (unsigned long)_end;
328 else 369 else
329 symbol_end = (unsigned 370 symbol_end = (unsigned long)_etext;
330 } 371 }
331 372
332 if (symbolsize) 373 if (symbolsize)
333 *symbolsize = symbol_end - sym 374 *symbolsize = symbol_end - symbol_start;
334 if (offset) 375 if (offset)
335 *offset = addr - symbol_start; 376 *offset = addr - symbol_start;
336 377
337 return low; 378 return low;
338 } 379 }
339 380
340 /* 381 /*
341 * Lookup an address but don't bother to find 382 * Lookup an address but don't bother to find any names.
342 */ 383 */
343 int kallsyms_lookup_size_offset(unsigned long 384 int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize,
344 unsigned long 385 unsigned long *offset)
345 { 386 {
346 char namebuf[KSYM_NAME_LEN]; 387 char namebuf[KSYM_NAME_LEN];
347 388
348 if (is_ksym_addr(addr)) { 389 if (is_ksym_addr(addr)) {
349 get_symbol_pos(addr, symbolsiz 390 get_symbol_pos(addr, symbolsize, offset);
350 return 1; 391 return 1;
351 } 392 }
352 return !!module_address_lookup(addr, s 393 return !!module_address_lookup(addr, symbolsize, offset, NULL, NULL, namebuf) ||
353 !!__bpf_address_lookup(addr, sy 394 !!__bpf_address_lookup(addr, symbolsize, offset, namebuf);
354 } 395 }
355 396
356 static int kallsyms_lookup_buildid(unsigned lo !! 397 static const char *kallsyms_lookup_buildid(unsigned long addr,
357 unsigned long *symbols 398 unsigned long *symbolsize,
358 unsigned long *offset, 399 unsigned long *offset, char **modname,
359 const unsigned char ** 400 const unsigned char **modbuildid, char *namebuf)
360 { 401 {
361 int ret; !! 402 const char *ret;
362 403
363 namebuf[KSYM_NAME_LEN - 1] = 0; 404 namebuf[KSYM_NAME_LEN - 1] = 0;
364 namebuf[0] = 0; 405 namebuf[0] = 0;
365 406
366 if (is_ksym_addr(addr)) { 407 if (is_ksym_addr(addr)) {
367 unsigned long pos; 408 unsigned long pos;
368 409
369 pos = get_symbol_pos(addr, sym 410 pos = get_symbol_pos(addr, symbolsize, offset);
370 /* Grab name */ 411 /* Grab name */
371 kallsyms_expand_symbol(get_sym 412 kallsyms_expand_symbol(get_symbol_offset(pos),
372 namebuf 413 namebuf, KSYM_NAME_LEN);
373 if (modname) 414 if (modname)
374 *modname = NULL; 415 *modname = NULL;
375 if (modbuildid) 416 if (modbuildid)
376 *modbuildid = NULL; 417 *modbuildid = NULL;
377 418
378 return strlen(namebuf); !! 419 ret = namebuf;
>> 420 goto found;
379 } 421 }
380 422
381 /* See if it's in a module or a BPF JI 423 /* See if it's in a module or a BPF JITed image. */
382 ret = module_address_lookup(addr, symb 424 ret = module_address_lookup(addr, symbolsize, offset,
383 modname, m 425 modname, modbuildid, namebuf);
384 if (!ret) 426 if (!ret)
385 ret = bpf_address_lookup(addr, 427 ret = bpf_address_lookup(addr, symbolsize,
386 offse 428 offset, modname, namebuf);
387 429
388 if (!ret) 430 if (!ret)
389 ret = ftrace_mod_address_looku 431 ret = ftrace_mod_address_lookup(addr, symbolsize,
390 432 offset, modname, namebuf);
391 433
>> 434 found:
>> 435 cleanup_symbol_name(namebuf);
392 return ret; 436 return ret;
393 } 437 }
394 438
395 /* 439 /*
396 * Lookup an address 440 * Lookup an address
397 * - modname is set to NULL if it's in the ker 441 * - modname is set to NULL if it's in the kernel.
398 * - We guarantee that the returned name is va 442 * - We guarantee that the returned name is valid until we reschedule even if.
399 * It resides in a module. 443 * It resides in a module.
400 * - We also guarantee that modname will be va 444 * - We also guarantee that modname will be valid until rescheduled.
401 */ 445 */
402 const char *kallsyms_lookup(unsigned long addr 446 const char *kallsyms_lookup(unsigned long addr,
403 unsigned long *sym 447 unsigned long *symbolsize,
404 unsigned long *off 448 unsigned long *offset,
405 char **modname, ch 449 char **modname, char *namebuf)
406 { 450 {
407 int ret = kallsyms_lookup_buildid(addr !! 451 return kallsyms_lookup_buildid(addr, symbolsize, offset, modname,
408 NULL !! 452 NULL, namebuf);
409 <<
410 if (!ret) <<
411 return NULL; <<
412 <<
413 return namebuf; <<
414 } 453 }
415 454
416 int lookup_symbol_name(unsigned long addr, cha 455 int lookup_symbol_name(unsigned long addr, char *symname)
417 { 456 {
>> 457 int res;
>> 458
418 symname[0] = '\0'; 459 symname[0] = '\0';
419 symname[KSYM_NAME_LEN - 1] = '\0'; 460 symname[KSYM_NAME_LEN - 1] = '\0';
420 461
421 if (is_ksym_addr(addr)) { 462 if (is_ksym_addr(addr)) {
422 unsigned long pos; 463 unsigned long pos;
423 464
424 pos = get_symbol_pos(addr, NUL 465 pos = get_symbol_pos(addr, NULL, NULL);
425 /* Grab name */ 466 /* Grab name */
426 kallsyms_expand_symbol(get_sym 467 kallsyms_expand_symbol(get_symbol_offset(pos),
427 symname 468 symname, KSYM_NAME_LEN);
428 return 0; !! 469 goto found;
429 } 470 }
430 /* See if it's in a module. */ 471 /* See if it's in a module. */
431 return lookup_module_symbol_name(addr, !! 472 res = lookup_module_symbol_name(addr, symname);
>> 473 if (res)
>> 474 return res;
>> 475
>> 476 found:
>> 477 cleanup_symbol_name(symname);
>> 478 return 0;
432 } 479 }
433 480
434 /* Look up a kernel symbol and return it in a 481 /* Look up a kernel symbol and return it in a text buffer. */
435 static int __sprint_symbol(char *buffer, unsig 482 static int __sprint_symbol(char *buffer, unsigned long address,
436 int symbol_offset, 483 int symbol_offset, int add_offset, int add_buildid)
437 { 484 {
438 char *modname; 485 char *modname;
439 const unsigned char *buildid; 486 const unsigned char *buildid;
>> 487 const char *name;
440 unsigned long offset, size; 488 unsigned long offset, size;
441 int len; 489 int len;
442 490
443 address += symbol_offset; 491 address += symbol_offset;
444 len = kallsyms_lookup_buildid(address, !! 492 name = kallsyms_lookup_buildid(address, &size, &offset, &modname, &buildid,
445 buffer) 493 buffer);
446 if (!len) !! 494 if (!name)
447 return sprintf(buffer, "0x%lx" 495 return sprintf(buffer, "0x%lx", address - symbol_offset);
448 496
>> 497 if (name != buffer)
>> 498 strcpy(buffer, name);
>> 499 len = strlen(buffer);
449 offset -= symbol_offset; 500 offset -= symbol_offset;
450 501
451 if (add_offset) 502 if (add_offset)
452 len += sprintf(buffer + len, " 503 len += sprintf(buffer + len, "+%#lx/%#lx", offset, size);
453 504
454 if (modname) { 505 if (modname) {
455 len += sprintf(buffer + len, " 506 len += sprintf(buffer + len, " [%s", modname);
456 #if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) 507 #if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
457 if (add_buildid && buildid) { 508 if (add_buildid && buildid) {
458 /* build ID should mat 509 /* build ID should match length of sprintf */
459 #if IS_ENABLED(CONFIG_MODULES) 510 #if IS_ENABLED(CONFIG_MODULES)
460 static_assert(sizeof(t 511 static_assert(sizeof(typeof_member(struct module, build_id)) == 20);
461 #endif 512 #endif
462 len += sprintf(buffer 513 len += sprintf(buffer + len, " %20phN", buildid);
463 } 514 }
464 #endif 515 #endif
465 len += sprintf(buffer + len, " 516 len += sprintf(buffer + len, "]");
466 } 517 }
467 518
468 return len; 519 return len;
469 } 520 }
470 521
471 /** 522 /**
472 * sprint_symbol - Look up a kernel symbol and 523 * sprint_symbol - Look up a kernel symbol and return it in a text buffer
473 * @buffer: buffer to be stored 524 * @buffer: buffer to be stored
474 * @address: address to lookup 525 * @address: address to lookup
475 * 526 *
476 * This function looks up a kernel symbol with 527 * This function looks up a kernel symbol with @address and stores its name,
477 * offset, size and module name to @buffer if 528 * offset, size and module name to @buffer if possible. If no symbol was found,
478 * just saves its @address as is. 529 * just saves its @address as is.
479 * 530 *
480 * This function returns the number of bytes s 531 * This function returns the number of bytes stored in @buffer.
481 */ 532 */
482 int sprint_symbol(char *buffer, unsigned long 533 int sprint_symbol(char *buffer, unsigned long address)
483 { 534 {
484 return __sprint_symbol(buffer, address 535 return __sprint_symbol(buffer, address, 0, 1, 0);
485 } 536 }
486 EXPORT_SYMBOL_GPL(sprint_symbol); 537 EXPORT_SYMBOL_GPL(sprint_symbol);
487 538
488 /** 539 /**
489 * sprint_symbol_build_id - Look up a kernel s 540 * sprint_symbol_build_id - Look up a kernel symbol and return it in a text buffer
490 * @buffer: buffer to be stored 541 * @buffer: buffer to be stored
491 * @address: address to lookup 542 * @address: address to lookup
492 * 543 *
493 * This function looks up a kernel symbol with 544 * This function looks up a kernel symbol with @address and stores its name,
494 * offset, size, module name and module build 545 * offset, size, module name and module build ID to @buffer if possible. If no
495 * symbol was found, just saves its @address a 546 * symbol was found, just saves its @address as is.
496 * 547 *
497 * This function returns the number of bytes s 548 * This function returns the number of bytes stored in @buffer.
498 */ 549 */
499 int sprint_symbol_build_id(char *buffer, unsig 550 int sprint_symbol_build_id(char *buffer, unsigned long address)
500 { 551 {
501 return __sprint_symbol(buffer, address 552 return __sprint_symbol(buffer, address, 0, 1, 1);
502 } 553 }
503 EXPORT_SYMBOL_GPL(sprint_symbol_build_id); 554 EXPORT_SYMBOL_GPL(sprint_symbol_build_id);
504 555
505 /** 556 /**
506 * sprint_symbol_no_offset - Look up a kernel 557 * sprint_symbol_no_offset - Look up a kernel symbol and return it in a text buffer
507 * @buffer: buffer to be stored 558 * @buffer: buffer to be stored
508 * @address: address to lookup 559 * @address: address to lookup
509 * 560 *
510 * This function looks up a kernel symbol with 561 * This function looks up a kernel symbol with @address and stores its name
511 * and module name to @buffer if possible. If 562 * and module name to @buffer if possible. If no symbol was found, just saves
512 * its @address as is. 563 * its @address as is.
513 * 564 *
514 * This function returns the number of bytes s 565 * This function returns the number of bytes stored in @buffer.
515 */ 566 */
516 int sprint_symbol_no_offset(char *buffer, unsi 567 int sprint_symbol_no_offset(char *buffer, unsigned long address)
517 { 568 {
518 return __sprint_symbol(buffer, address 569 return __sprint_symbol(buffer, address, 0, 0, 0);
519 } 570 }
520 EXPORT_SYMBOL_GPL(sprint_symbol_no_offset); 571 EXPORT_SYMBOL_GPL(sprint_symbol_no_offset);
521 572
522 /** 573 /**
523 * sprint_backtrace - Look up a backtrace symb 574 * sprint_backtrace - Look up a backtrace symbol and return it in a text buffer
524 * @buffer: buffer to be stored 575 * @buffer: buffer to be stored
525 * @address: address to lookup 576 * @address: address to lookup
526 * 577 *
527 * This function is for stack backtrace and do 578 * This function is for stack backtrace and does the same thing as
528 * sprint_symbol() but with modified/decreased 579 * sprint_symbol() but with modified/decreased @address. If there is a
529 * tail-call to the function marked "noreturn" 580 * tail-call to the function marked "noreturn", gcc optimized out code after
530 * the call so that the stack-saved return add 581 * the call so that the stack-saved return address could point outside of the
531 * caller. This function ensures that kallsyms 582 * caller. This function ensures that kallsyms will find the original caller
532 * by decreasing @address. 583 * by decreasing @address.
533 * 584 *
534 * This function returns the number of bytes s 585 * This function returns the number of bytes stored in @buffer.
535 */ 586 */
536 int sprint_backtrace(char *buffer, unsigned lo 587 int sprint_backtrace(char *buffer, unsigned long address)
537 { 588 {
538 return __sprint_symbol(buffer, address 589 return __sprint_symbol(buffer, address, -1, 1, 0);
539 } 590 }
540 591
541 /** 592 /**
542 * sprint_backtrace_build_id - Look up a backt 593 * sprint_backtrace_build_id - Look up a backtrace symbol and return it in a text buffer
543 * @buffer: buffer to be stored 594 * @buffer: buffer to be stored
544 * @address: address to lookup 595 * @address: address to lookup
545 * 596 *
546 * This function is for stack backtrace and do 597 * This function is for stack backtrace and does the same thing as
547 * sprint_symbol() but with modified/decreased 598 * sprint_symbol() but with modified/decreased @address. If there is a
548 * tail-call to the function marked "noreturn" 599 * tail-call to the function marked "noreturn", gcc optimized out code after
549 * the call so that the stack-saved return add 600 * the call so that the stack-saved return address could point outside of the
550 * caller. This function ensures that kallsyms 601 * caller. This function ensures that kallsyms will find the original caller
551 * by decreasing @address. This function also 602 * by decreasing @address. This function also appends the module build ID to
552 * the @buffer if @address is within a kernel 603 * the @buffer if @address is within a kernel module.
553 * 604 *
554 * This function returns the number of bytes s 605 * This function returns the number of bytes stored in @buffer.
555 */ 606 */
556 int sprint_backtrace_build_id(char *buffer, un 607 int sprint_backtrace_build_id(char *buffer, unsigned long address)
557 { 608 {
558 return __sprint_symbol(buffer, address 609 return __sprint_symbol(buffer, address, -1, 1, 1);
559 } 610 }
560 611
561 /* To avoid using get_symbol_offset for every 612 /* To avoid using get_symbol_offset for every symbol, we carry prefix along. */
562 struct kallsym_iter { 613 struct kallsym_iter {
563 loff_t pos; 614 loff_t pos;
564 loff_t pos_mod_end; 615 loff_t pos_mod_end;
565 loff_t pos_ftrace_mod_end; 616 loff_t pos_ftrace_mod_end;
566 loff_t pos_bpf_end; 617 loff_t pos_bpf_end;
567 unsigned long value; 618 unsigned long value;
568 unsigned int nameoff; /* If iterating 619 unsigned int nameoff; /* If iterating in core kernel symbols. */
569 char type; 620 char type;
570 char name[KSYM_NAME_LEN]; 621 char name[KSYM_NAME_LEN];
571 char module_name[MODULE_NAME_LEN]; 622 char module_name[MODULE_NAME_LEN];
572 int exported; 623 int exported;
573 int show_value; 624 int show_value;
574 }; 625 };
575 626
576 static int get_ksymbol_mod(struct kallsym_iter 627 static int get_ksymbol_mod(struct kallsym_iter *iter)
577 { 628 {
578 int ret = module_get_kallsym(iter->pos 629 int ret = module_get_kallsym(iter->pos - kallsyms_num_syms,
579 &iter->va 630 &iter->value, &iter->type,
580 iter->nam 631 iter->name, iter->module_name,
581 &iter->ex 632 &iter->exported);
582 if (ret < 0) { 633 if (ret < 0) {
583 iter->pos_mod_end = iter->pos; 634 iter->pos_mod_end = iter->pos;
584 return 0; 635 return 0;
585 } 636 }
586 637
587 return 1; 638 return 1;
588 } 639 }
589 640
590 /* 641 /*
591 * ftrace_mod_get_kallsym() may also get symbo 642 * ftrace_mod_get_kallsym() may also get symbols for pages allocated for ftrace
592 * purposes. In that case "__builtin__ftrace" 643 * purposes. In that case "__builtin__ftrace" is used as a module name, even
593 * though "__builtin__ftrace" is not a module. 644 * though "__builtin__ftrace" is not a module.
594 */ 645 */
595 static int get_ksymbol_ftrace_mod(struct kalls 646 static int get_ksymbol_ftrace_mod(struct kallsym_iter *iter)
596 { 647 {
597 int ret = ftrace_mod_get_kallsym(iter- 648 int ret = ftrace_mod_get_kallsym(iter->pos - iter->pos_mod_end,
598 &iter 649 &iter->value, &iter->type,
599 iter- 650 iter->name, iter->module_name,
600 &iter 651 &iter->exported);
601 if (ret < 0) { 652 if (ret < 0) {
602 iter->pos_ftrace_mod_end = ite 653 iter->pos_ftrace_mod_end = iter->pos;
603 return 0; 654 return 0;
604 } 655 }
605 656
606 return 1; 657 return 1;
607 } 658 }
608 659
609 static int get_ksymbol_bpf(struct kallsym_iter 660 static int get_ksymbol_bpf(struct kallsym_iter *iter)
610 { 661 {
611 int ret; 662 int ret;
612 663
613 strscpy(iter->module_name, "bpf", MODU 664 strscpy(iter->module_name, "bpf", MODULE_NAME_LEN);
614 iter->exported = 0; 665 iter->exported = 0;
615 ret = bpf_get_kallsym(iter->pos - iter 666 ret = bpf_get_kallsym(iter->pos - iter->pos_ftrace_mod_end,
616 &iter->value, &i 667 &iter->value, &iter->type,
617 iter->name); 668 iter->name);
618 if (ret < 0) { 669 if (ret < 0) {
619 iter->pos_bpf_end = iter->pos; 670 iter->pos_bpf_end = iter->pos;
620 return 0; 671 return 0;
621 } 672 }
622 673
623 return 1; 674 return 1;
624 } 675 }
625 676
626 /* 677 /*
627 * This uses "__builtin__kprobes" as a module 678 * This uses "__builtin__kprobes" as a module name for symbols for pages
628 * allocated for kprobes' purposes, even thoug 679 * allocated for kprobes' purposes, even though "__builtin__kprobes" is not a
629 * module. 680 * module.
630 */ 681 */
631 static int get_ksymbol_kprobe(struct kallsym_i 682 static int get_ksymbol_kprobe(struct kallsym_iter *iter)
632 { 683 {
633 strscpy(iter->module_name, "__builtin_ 684 strscpy(iter->module_name, "__builtin__kprobes", MODULE_NAME_LEN);
634 iter->exported = 0; 685 iter->exported = 0;
635 return kprobe_get_kallsym(iter->pos - 686 return kprobe_get_kallsym(iter->pos - iter->pos_bpf_end,
636 &iter->value 687 &iter->value, &iter->type,
637 iter->name) 688 iter->name) < 0 ? 0 : 1;
638 } 689 }
639 690
640 /* Returns space to next name. */ 691 /* Returns space to next name. */
641 static unsigned long get_ksymbol_core(struct k 692 static unsigned long get_ksymbol_core(struct kallsym_iter *iter)
642 { 693 {
643 unsigned off = iter->nameoff; 694 unsigned off = iter->nameoff;
644 695
645 iter->module_name[0] = '\0'; 696 iter->module_name[0] = '\0';
646 iter->value = kallsyms_sym_address(ite 697 iter->value = kallsyms_sym_address(iter->pos);
647 698
648 iter->type = kallsyms_get_symbol_type( 699 iter->type = kallsyms_get_symbol_type(off);
649 700
650 off = kallsyms_expand_symbol(off, iter 701 off = kallsyms_expand_symbol(off, iter->name, ARRAY_SIZE(iter->name));
651 702
652 return off - iter->nameoff; 703 return off - iter->nameoff;
653 } 704 }
654 705
655 static void reset_iter(struct kallsym_iter *it 706 static void reset_iter(struct kallsym_iter *iter, loff_t new_pos)
656 { 707 {
657 iter->name[0] = '\0'; 708 iter->name[0] = '\0';
658 iter->nameoff = get_symbol_offset(new_ 709 iter->nameoff = get_symbol_offset(new_pos);
659 iter->pos = new_pos; 710 iter->pos = new_pos;
660 if (new_pos == 0) { 711 if (new_pos == 0) {
661 iter->pos_mod_end = 0; 712 iter->pos_mod_end = 0;
662 iter->pos_ftrace_mod_end = 0; 713 iter->pos_ftrace_mod_end = 0;
663 iter->pos_bpf_end = 0; 714 iter->pos_bpf_end = 0;
664 } 715 }
665 } 716 }
666 717
667 /* 718 /*
668 * The end position (last + 1) of each additio 719 * The end position (last + 1) of each additional kallsyms section is recorded
669 * in iter->pos_..._end as each section is add 720 * in iter->pos_..._end as each section is added, and so can be used to
670 * determine which get_ksymbol_...() function 721 * determine which get_ksymbol_...() function to call next.
671 */ 722 */
672 static int update_iter_mod(struct kallsym_iter 723 static int update_iter_mod(struct kallsym_iter *iter, loff_t pos)
673 { 724 {
674 iter->pos = pos; 725 iter->pos = pos;
675 726
676 if ((!iter->pos_mod_end || iter->pos_m 727 if ((!iter->pos_mod_end || iter->pos_mod_end > pos) &&
677 get_ksymbol_mod(iter)) 728 get_ksymbol_mod(iter))
678 return 1; 729 return 1;
679 730
680 if ((!iter->pos_ftrace_mod_end || iter 731 if ((!iter->pos_ftrace_mod_end || iter->pos_ftrace_mod_end > pos) &&
681 get_ksymbol_ftrace_mod(iter)) 732 get_ksymbol_ftrace_mod(iter))
682 return 1; 733 return 1;
683 734
684 if ((!iter->pos_bpf_end || iter->pos_b 735 if ((!iter->pos_bpf_end || iter->pos_bpf_end > pos) &&
685 get_ksymbol_bpf(iter)) 736 get_ksymbol_bpf(iter))
686 return 1; 737 return 1;
687 738
688 return get_ksymbol_kprobe(iter); 739 return get_ksymbol_kprobe(iter);
689 } 740 }
690 741
691 /* Returns false if pos at or past end of file 742 /* Returns false if pos at or past end of file. */
692 static int update_iter(struct kallsym_iter *it 743 static int update_iter(struct kallsym_iter *iter, loff_t pos)
693 { 744 {
694 /* Module symbols can be accessed rand 745 /* Module symbols can be accessed randomly. */
695 if (pos >= kallsyms_num_syms) 746 if (pos >= kallsyms_num_syms)
696 return update_iter_mod(iter, p 747 return update_iter_mod(iter, pos);
697 748
698 /* If we're not on the desired positio 749 /* If we're not on the desired position, reset to new position. */
699 if (pos != iter->pos) 750 if (pos != iter->pos)
700 reset_iter(iter, pos); 751 reset_iter(iter, pos);
701 752
702 iter->nameoff += get_ksymbol_core(iter 753 iter->nameoff += get_ksymbol_core(iter);
703 iter->pos++; 754 iter->pos++;
704 755
705 return 1; 756 return 1;
706 } 757 }
707 758
708 static void *s_next(struct seq_file *m, void * 759 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
709 { 760 {
710 (*pos)++; 761 (*pos)++;
711 762
712 if (!update_iter(m->private, *pos)) 763 if (!update_iter(m->private, *pos))
713 return NULL; 764 return NULL;
714 return p; 765 return p;
715 } 766 }
716 767
717 static void *s_start(struct seq_file *m, loff_ 768 static void *s_start(struct seq_file *m, loff_t *pos)
718 { 769 {
719 if (!update_iter(m->private, *pos)) 770 if (!update_iter(m->private, *pos))
720 return NULL; 771 return NULL;
721 return m->private; 772 return m->private;
722 } 773 }
723 774
724 static void s_stop(struct seq_file *m, void *p 775 static void s_stop(struct seq_file *m, void *p)
725 { 776 {
726 } 777 }
727 778
728 static int s_show(struct seq_file *m, void *p) 779 static int s_show(struct seq_file *m, void *p)
729 { 780 {
730 void *value; 781 void *value;
731 struct kallsym_iter *iter = m->private 782 struct kallsym_iter *iter = m->private;
732 783
733 /* Some debugging symbols have no name 784 /* Some debugging symbols have no name. Ignore them. */
734 if (!iter->name[0]) 785 if (!iter->name[0])
735 return 0; 786 return 0;
736 787
737 value = iter->show_value ? (void *)ite 788 value = iter->show_value ? (void *)iter->value : NULL;
738 789
739 if (iter->module_name[0]) { 790 if (iter->module_name[0]) {
740 char type; 791 char type;
741 792
742 /* 793 /*
743 * Label it "global" if it is 794 * Label it "global" if it is exported,
744 * "local" if not exported. 795 * "local" if not exported.
745 */ 796 */
746 type = iter->exported ? touppe 797 type = iter->exported ? toupper(iter->type) :
747 tolowe 798 tolower(iter->type);
748 seq_printf(m, "%px %c %s\t[%s] 799 seq_printf(m, "%px %c %s\t[%s]\n", value,
749 type, iter->name, i 800 type, iter->name, iter->module_name);
750 } else 801 } else
751 seq_printf(m, "%px %c %s\n", v 802 seq_printf(m, "%px %c %s\n", value,
752 iter->type, iter->n 803 iter->type, iter->name);
753 return 0; 804 return 0;
754 } 805 }
755 806
756 static const struct seq_operations kallsyms_op 807 static const struct seq_operations kallsyms_op = {
757 .start = s_start, 808 .start = s_start,
758 .next = s_next, 809 .next = s_next,
759 .stop = s_stop, 810 .stop = s_stop,
760 .show = s_show 811 .show = s_show
761 }; 812 };
762 813
763 #ifdef CONFIG_BPF_SYSCALL 814 #ifdef CONFIG_BPF_SYSCALL
764 815
765 struct bpf_iter__ksym { 816 struct bpf_iter__ksym {
766 __bpf_md_ptr(struct bpf_iter_meta *, m 817 __bpf_md_ptr(struct bpf_iter_meta *, meta);
767 __bpf_md_ptr(struct kallsym_iter *, ks 818 __bpf_md_ptr(struct kallsym_iter *, ksym);
768 }; 819 };
769 820
770 static int ksym_prog_seq_show(struct seq_file 821 static int ksym_prog_seq_show(struct seq_file *m, bool in_stop)
771 { 822 {
772 struct bpf_iter__ksym ctx; 823 struct bpf_iter__ksym ctx;
773 struct bpf_iter_meta meta; 824 struct bpf_iter_meta meta;
774 struct bpf_prog *prog; 825 struct bpf_prog *prog;
775 826
776 meta.seq = m; 827 meta.seq = m;
777 prog = bpf_iter_get_info(&meta, in_sto 828 prog = bpf_iter_get_info(&meta, in_stop);
778 if (!prog) 829 if (!prog)
779 return 0; 830 return 0;
780 831
781 ctx.meta = &meta; 832 ctx.meta = &meta;
782 ctx.ksym = m ? m->private : NULL; 833 ctx.ksym = m ? m->private : NULL;
783 return bpf_iter_run_prog(prog, &ctx); 834 return bpf_iter_run_prog(prog, &ctx);
784 } 835 }
785 836
786 static int bpf_iter_ksym_seq_show(struct seq_f 837 static int bpf_iter_ksym_seq_show(struct seq_file *m, void *p)
787 { 838 {
788 return ksym_prog_seq_show(m, false); 839 return ksym_prog_seq_show(m, false);
789 } 840 }
790 841
791 static void bpf_iter_ksym_seq_stop(struct seq_ 842 static void bpf_iter_ksym_seq_stop(struct seq_file *m, void *p)
792 { 843 {
793 if (!p) 844 if (!p)
794 (void) ksym_prog_seq_show(m, t 845 (void) ksym_prog_seq_show(m, true);
795 else 846 else
796 s_stop(m, p); 847 s_stop(m, p);
797 } 848 }
798 849
799 static const struct seq_operations bpf_iter_ks 850 static const struct seq_operations bpf_iter_ksym_ops = {
800 .start = s_start, 851 .start = s_start,
801 .next = s_next, 852 .next = s_next,
802 .stop = bpf_iter_ksym_seq_stop, 853 .stop = bpf_iter_ksym_seq_stop,
803 .show = bpf_iter_ksym_seq_show, 854 .show = bpf_iter_ksym_seq_show,
804 }; 855 };
805 856
806 static int bpf_iter_ksym_init(void *priv_data, 857 static int bpf_iter_ksym_init(void *priv_data, struct bpf_iter_aux_info *aux)
807 { 858 {
808 struct kallsym_iter *iter = priv_data; 859 struct kallsym_iter *iter = priv_data;
809 860
810 reset_iter(iter, 0); 861 reset_iter(iter, 0);
811 862
812 /* cache here as in kallsyms_open() ca 863 /* cache here as in kallsyms_open() case; use current process
813 * credentials to tell BPF iterators i 864 * credentials to tell BPF iterators if values should be shown.
814 */ 865 */
815 iter->show_value = kallsyms_show_value 866 iter->show_value = kallsyms_show_value(current_cred());
816 867
817 return 0; 868 return 0;
818 } 869 }
819 870
820 DEFINE_BPF_ITER_FUNC(ksym, struct bpf_iter_met 871 DEFINE_BPF_ITER_FUNC(ksym, struct bpf_iter_meta *meta, struct kallsym_iter *ksym)
821 872
822 static const struct bpf_iter_seq_info ksym_ite 873 static const struct bpf_iter_seq_info ksym_iter_seq_info = {
823 .seq_ops = &bpf_iter_ks 874 .seq_ops = &bpf_iter_ksym_ops,
824 .init_seq_private = bpf_iter_ksy 875 .init_seq_private = bpf_iter_ksym_init,
825 .fini_seq_private = NULL, 876 .fini_seq_private = NULL,
826 .seq_priv_size = sizeof(struc 877 .seq_priv_size = sizeof(struct kallsym_iter),
827 }; 878 };
828 879
829 static struct bpf_iter_reg ksym_iter_reg_info 880 static struct bpf_iter_reg ksym_iter_reg_info = {
830 .target = "ksym", 881 .target = "ksym",
831 .feature = BPF_ITER_RES 882 .feature = BPF_ITER_RESCHED,
832 .ctx_arg_info_size = 1, 883 .ctx_arg_info_size = 1,
833 .ctx_arg_info = { 884 .ctx_arg_info = {
834 { offsetof(struct bpf_iter__ks 885 { offsetof(struct bpf_iter__ksym, ksym),
835 PTR_TO_BTF_ID_OR_NULL }, 886 PTR_TO_BTF_ID_OR_NULL },
836 }, 887 },
837 .seq_info = &ksym_iter_s 888 .seq_info = &ksym_iter_seq_info,
838 }; 889 };
839 890
840 BTF_ID_LIST(btf_ksym_iter_id) 891 BTF_ID_LIST(btf_ksym_iter_id)
841 BTF_ID(struct, kallsym_iter) 892 BTF_ID(struct, kallsym_iter)
842 893
843 static int __init bpf_ksym_iter_register(void) 894 static int __init bpf_ksym_iter_register(void)
844 { 895 {
845 ksym_iter_reg_info.ctx_arg_info[0].btf 896 ksym_iter_reg_info.ctx_arg_info[0].btf_id = *btf_ksym_iter_id;
846 return bpf_iter_reg_target(&ksym_iter_ 897 return bpf_iter_reg_target(&ksym_iter_reg_info);
847 } 898 }
848 899
849 late_initcall(bpf_ksym_iter_register); 900 late_initcall(bpf_ksym_iter_register);
850 901
851 #endif /* CONFIG_BPF_SYSCALL */ 902 #endif /* CONFIG_BPF_SYSCALL */
852 903
853 static int kallsyms_open(struct inode *inode, 904 static int kallsyms_open(struct inode *inode, struct file *file)
854 { 905 {
855 /* 906 /*
856 * We keep iterator in m->private, sin 907 * We keep iterator in m->private, since normal case is to
857 * s_start from where we left off, so 908 * s_start from where we left off, so we avoid doing
858 * using get_symbol_offset for every s 909 * using get_symbol_offset for every symbol.
859 */ 910 */
860 struct kallsym_iter *iter; 911 struct kallsym_iter *iter;
861 iter = __seq_open_private(file, &kalls 912 iter = __seq_open_private(file, &kallsyms_op, sizeof(*iter));
862 if (!iter) 913 if (!iter)
863 return -ENOMEM; 914 return -ENOMEM;
864 reset_iter(iter, 0); 915 reset_iter(iter, 0);
865 916
866 /* 917 /*
867 * Instead of checking this on every s 918 * Instead of checking this on every s_show() call, cache
868 * the result here at open time. 919 * the result here at open time.
869 */ 920 */
870 iter->show_value = kallsyms_show_value 921 iter->show_value = kallsyms_show_value(file->f_cred);
871 return 0; 922 return 0;
872 } 923 }
873 924
874 #ifdef CONFIG_KGDB_KDB 925 #ifdef CONFIG_KGDB_KDB
875 const char *kdb_walk_kallsyms(loff_t *pos) 926 const char *kdb_walk_kallsyms(loff_t *pos)
876 { 927 {
877 static struct kallsym_iter kdb_walk_ka 928 static struct kallsym_iter kdb_walk_kallsyms_iter;
878 if (*pos == 0) { 929 if (*pos == 0) {
879 memset(&kdb_walk_kallsyms_iter 930 memset(&kdb_walk_kallsyms_iter, 0,
880 sizeof(kdb_walk_kallsym 931 sizeof(kdb_walk_kallsyms_iter));
881 reset_iter(&kdb_walk_kallsyms_ 932 reset_iter(&kdb_walk_kallsyms_iter, 0);
882 } 933 }
883 while (1) { 934 while (1) {
884 if (!update_iter(&kdb_walk_kal 935 if (!update_iter(&kdb_walk_kallsyms_iter, *pos))
885 return NULL; 936 return NULL;
886 ++*pos; 937 ++*pos;
887 /* Some debugging symbols have 938 /* Some debugging symbols have no name. Ignore them. */
888 if (kdb_walk_kallsyms_iter.nam 939 if (kdb_walk_kallsyms_iter.name[0])
889 return kdb_walk_kallsy 940 return kdb_walk_kallsyms_iter.name;
890 } 941 }
891 } 942 }
892 #endif /* CONFIG_KGDB_KDB */ 943 #endif /* CONFIG_KGDB_KDB */
893 944
894 static const struct proc_ops kallsyms_proc_ops 945 static const struct proc_ops kallsyms_proc_ops = {
895 .proc_open = kallsyms_open, 946 .proc_open = kallsyms_open,
896 .proc_read = seq_read, 947 .proc_read = seq_read,
897 .proc_lseek = seq_lseek, 948 .proc_lseek = seq_lseek,
898 .proc_release = seq_release_private, 949 .proc_release = seq_release_private,
899 }; 950 };
900 951
901 static int __init kallsyms_init(void) 952 static int __init kallsyms_init(void)
902 { 953 {
903 proc_create("kallsyms", 0444, NULL, &k 954 proc_create("kallsyms", 0444, NULL, &kallsyms_proc_ops);
904 return 0; 955 return 0;
905 } 956 }
906 device_initcall(kallsyms_init); 957 device_initcall(kallsyms_init);
907 958
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