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