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7ce7e424 TZ |
1 | /* |
2 | * trace_events_filter - generic event filtering | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | * | |
18 | * Copyright (C) 2009 Tom Zanussi <tzanussi@gmail.com> | |
19 | */ | |
20 | ||
7ce7e424 TZ |
21 | #include <linux/module.h> |
22 | #include <linux/ctype.h> | |
ac1adc55 | 23 | #include <linux/mutex.h> |
6fb2915d | 24 | #include <linux/perf_event.h> |
5a0e3ad6 | 25 | #include <linux/slab.h> |
7ce7e424 TZ |
26 | |
27 | #include "trace.h" | |
4bda2d51 | 28 | #include "trace_output.h" |
7ce7e424 | 29 | |
8b372562 | 30 | enum filter_op_ids |
7ce7e424 | 31 | { |
8b372562 TZ |
32 | OP_OR, |
33 | OP_AND, | |
b0f1a59a | 34 | OP_GLOB, |
8b372562 TZ |
35 | OP_NE, |
36 | OP_EQ, | |
37 | OP_LT, | |
38 | OP_LE, | |
39 | OP_GT, | |
40 | OP_GE, | |
41 | OP_NONE, | |
42 | OP_OPEN_PAREN, | |
43 | }; | |
44 | ||
45 | struct filter_op { | |
46 | int id; | |
47 | char *string; | |
48 | int precedence; | |
49 | }; | |
50 | ||
51 | static struct filter_op filter_ops[] = { | |
b0f1a59a LZ |
52 | { OP_OR, "||", 1 }, |
53 | { OP_AND, "&&", 2 }, | |
54 | { OP_GLOB, "~", 4 }, | |
55 | { OP_NE, "!=", 4 }, | |
56 | { OP_EQ, "==", 4 }, | |
57 | { OP_LT, "<", 5 }, | |
58 | { OP_LE, "<=", 5 }, | |
59 | { OP_GT, ">", 5 }, | |
60 | { OP_GE, ">=", 5 }, | |
61 | { OP_NONE, "OP_NONE", 0 }, | |
62 | { OP_OPEN_PAREN, "(", 0 }, | |
8b372562 TZ |
63 | }; |
64 | ||
65 | enum { | |
66 | FILT_ERR_NONE, | |
67 | FILT_ERR_INVALID_OP, | |
68 | FILT_ERR_UNBALANCED_PAREN, | |
69 | FILT_ERR_TOO_MANY_OPERANDS, | |
70 | FILT_ERR_OPERAND_TOO_LONG, | |
71 | FILT_ERR_FIELD_NOT_FOUND, | |
72 | FILT_ERR_ILLEGAL_FIELD_OP, | |
73 | FILT_ERR_ILLEGAL_INTVAL, | |
74 | FILT_ERR_BAD_SUBSYS_FILTER, | |
75 | FILT_ERR_TOO_MANY_PREDS, | |
76 | FILT_ERR_MISSING_FIELD, | |
77 | FILT_ERR_INVALID_FILTER, | |
78 | }; | |
79 | ||
80 | static char *err_text[] = { | |
81 | "No error", | |
82 | "Invalid operator", | |
83 | "Unbalanced parens", | |
84 | "Too many operands", | |
85 | "Operand too long", | |
86 | "Field not found", | |
87 | "Illegal operation for field type", | |
88 | "Illegal integer value", | |
89 | "Couldn't find or set field in one of a subsystem's events", | |
90 | "Too many terms in predicate expression", | |
91 | "Missing field name and/or value", | |
92 | "Meaningless filter expression", | |
93 | }; | |
94 | ||
95 | struct opstack_op { | |
96 | int op; | |
97 | struct list_head list; | |
98 | }; | |
99 | ||
100 | struct postfix_elt { | |
101 | int op; | |
102 | char *operand; | |
103 | struct list_head list; | |
104 | }; | |
105 | ||
106 | struct filter_parse_state { | |
107 | struct filter_op *ops; | |
108 | struct list_head opstack; | |
109 | struct list_head postfix; | |
110 | int lasterr; | |
111 | int lasterr_pos; | |
112 | ||
113 | struct { | |
114 | char *string; | |
115 | unsigned int cnt; | |
116 | unsigned int tail; | |
117 | } infix; | |
118 | ||
119 | struct { | |
120 | char string[MAX_FILTER_STR_VAL]; | |
121 | int pos; | |
122 | unsigned int tail; | |
123 | } operand; | |
124 | }; | |
125 | ||
197e2eab | 126 | #define DEFINE_COMPARISON_PRED(type) \ |
58d9a597 | 127 | static int filter_pred_##type(struct filter_pred *pred, void *event) \ |
197e2eab LZ |
128 | { \ |
129 | type *addr = (type *)(event + pred->offset); \ | |
130 | type val = (type)pred->val; \ | |
131 | int match = 0; \ | |
132 | \ | |
133 | switch (pred->op) { \ | |
134 | case OP_LT: \ | |
135 | match = (*addr < val); \ | |
136 | break; \ | |
137 | case OP_LE: \ | |
138 | match = (*addr <= val); \ | |
139 | break; \ | |
140 | case OP_GT: \ | |
141 | match = (*addr > val); \ | |
142 | break; \ | |
143 | case OP_GE: \ | |
144 | match = (*addr >= val); \ | |
145 | break; \ | |
146 | default: \ | |
147 | break; \ | |
148 | } \ | |
149 | \ | |
150 | return match; \ | |
151 | } | |
152 | ||
153 | #define DEFINE_EQUALITY_PRED(size) \ | |
58d9a597 | 154 | static int filter_pred_##size(struct filter_pred *pred, void *event) \ |
197e2eab LZ |
155 | { \ |
156 | u##size *addr = (u##size *)(event + pred->offset); \ | |
157 | u##size val = (u##size)pred->val; \ | |
158 | int match; \ | |
159 | \ | |
160 | match = (val == *addr) ^ pred->not; \ | |
161 | \ | |
162 | return match; \ | |
163 | } | |
164 | ||
8b372562 TZ |
165 | DEFINE_COMPARISON_PRED(s64); |
166 | DEFINE_COMPARISON_PRED(u64); | |
167 | DEFINE_COMPARISON_PRED(s32); | |
168 | DEFINE_COMPARISON_PRED(u32); | |
169 | DEFINE_COMPARISON_PRED(s16); | |
170 | DEFINE_COMPARISON_PRED(u16); | |
171 | DEFINE_COMPARISON_PRED(s8); | |
172 | DEFINE_COMPARISON_PRED(u8); | |
173 | ||
174 | DEFINE_EQUALITY_PRED(64); | |
175 | DEFINE_EQUALITY_PRED(32); | |
176 | DEFINE_EQUALITY_PRED(16); | |
177 | DEFINE_EQUALITY_PRED(8); | |
178 | ||
e8808c10 | 179 | /* Filter predicate for fixed sized arrays of characters */ |
58d9a597 | 180 | static int filter_pred_string(struct filter_pred *pred, void *event) |
7ce7e424 TZ |
181 | { |
182 | char *addr = (char *)(event + pred->offset); | |
183 | int cmp, match; | |
184 | ||
1889d209 | 185 | cmp = pred->regex.match(addr, &pred->regex, pred->regex.field_len); |
7ce7e424 | 186 | |
1889d209 | 187 | match = cmp ^ pred->not; |
7ce7e424 TZ |
188 | |
189 | return match; | |
190 | } | |
191 | ||
87a342f5 | 192 | /* Filter predicate for char * pointers */ |
58d9a597 | 193 | static int filter_pred_pchar(struct filter_pred *pred, void *event) |
87a342f5 LZ |
194 | { |
195 | char **addr = (char **)(event + pred->offset); | |
196 | int cmp, match; | |
16da27a8 | 197 | int len = strlen(*addr) + 1; /* including tailing '\0' */ |
87a342f5 | 198 | |
16da27a8 | 199 | cmp = pred->regex.match(*addr, &pred->regex, len); |
87a342f5 | 200 | |
1889d209 | 201 | match = cmp ^ pred->not; |
87a342f5 LZ |
202 | |
203 | return match; | |
204 | } | |
205 | ||
e8808c10 FW |
206 | /* |
207 | * Filter predicate for dynamic sized arrays of characters. | |
208 | * These are implemented through a list of strings at the end | |
209 | * of the entry. | |
210 | * Also each of these strings have a field in the entry which | |
211 | * contains its offset from the beginning of the entry. | |
212 | * We have then first to get this field, dereference it | |
213 | * and add it to the address of the entry, and at last we have | |
214 | * the address of the string. | |
215 | */ | |
58d9a597 | 216 | static int filter_pred_strloc(struct filter_pred *pred, void *event) |
e8808c10 | 217 | { |
7d536cb3 LZ |
218 | u32 str_item = *(u32 *)(event + pred->offset); |
219 | int str_loc = str_item & 0xffff; | |
220 | int str_len = str_item >> 16; | |
e8808c10 FW |
221 | char *addr = (char *)(event + str_loc); |
222 | int cmp, match; | |
223 | ||
1889d209 | 224 | cmp = pred->regex.match(addr, &pred->regex, str_len); |
e8808c10 | 225 | |
1889d209 | 226 | match = cmp ^ pred->not; |
e8808c10 FW |
227 | |
228 | return match; | |
229 | } | |
230 | ||
58d9a597 | 231 | static int filter_pred_none(struct filter_pred *pred, void *event) |
0a19e53c TZ |
232 | { |
233 | return 0; | |
234 | } | |
235 | ||
d1303dd1 LZ |
236 | /* |
237 | * regex_match_foo - Basic regex callbacks | |
238 | * | |
239 | * @str: the string to be searched | |
240 | * @r: the regex structure containing the pattern string | |
241 | * @len: the length of the string to be searched (including '\0') | |
242 | * | |
243 | * Note: | |
244 | * - @str might not be NULL-terminated if it's of type DYN_STRING | |
245 | * or STATIC_STRING | |
246 | */ | |
247 | ||
1889d209 FW |
248 | static int regex_match_full(char *str, struct regex *r, int len) |
249 | { | |
250 | if (strncmp(str, r->pattern, len) == 0) | |
251 | return 1; | |
252 | return 0; | |
253 | } | |
254 | ||
255 | static int regex_match_front(char *str, struct regex *r, int len) | |
256 | { | |
285caad4 | 257 | if (strncmp(str, r->pattern, r->len) == 0) |
1889d209 FW |
258 | return 1; |
259 | return 0; | |
260 | } | |
261 | ||
262 | static int regex_match_middle(char *str, struct regex *r, int len) | |
263 | { | |
b2af211f | 264 | if (strnstr(str, r->pattern, len)) |
1889d209 FW |
265 | return 1; |
266 | return 0; | |
267 | } | |
268 | ||
269 | static int regex_match_end(char *str, struct regex *r, int len) | |
270 | { | |
a3291c14 | 271 | int strlen = len - 1; |
1889d209 | 272 | |
a3291c14 LZ |
273 | if (strlen >= r->len && |
274 | memcmp(str + strlen - r->len, r->pattern, r->len) == 0) | |
1889d209 FW |
275 | return 1; |
276 | return 0; | |
277 | } | |
278 | ||
3f6fe06d FW |
279 | /** |
280 | * filter_parse_regex - parse a basic regex | |
281 | * @buff: the raw regex | |
282 | * @len: length of the regex | |
283 | * @search: will point to the beginning of the string to compare | |
284 | * @not: tell whether the match will have to be inverted | |
285 | * | |
286 | * This passes in a buffer containing a regex and this function will | |
1889d209 FW |
287 | * set search to point to the search part of the buffer and |
288 | * return the type of search it is (see enum above). | |
289 | * This does modify buff. | |
290 | * | |
291 | * Returns enum type. | |
292 | * search returns the pointer to use for comparison. | |
293 | * not returns 1 if buff started with a '!' | |
294 | * 0 otherwise. | |
295 | */ | |
3f6fe06d | 296 | enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not) |
1889d209 FW |
297 | { |
298 | int type = MATCH_FULL; | |
299 | int i; | |
300 | ||
301 | if (buff[0] == '!') { | |
302 | *not = 1; | |
303 | buff++; | |
304 | len--; | |
305 | } else | |
306 | *not = 0; | |
307 | ||
308 | *search = buff; | |
309 | ||
310 | for (i = 0; i < len; i++) { | |
311 | if (buff[i] == '*') { | |
312 | if (!i) { | |
313 | *search = buff + 1; | |
314 | type = MATCH_END_ONLY; | |
315 | } else { | |
316 | if (type == MATCH_END_ONLY) | |
317 | type = MATCH_MIDDLE_ONLY; | |
318 | else | |
319 | type = MATCH_FRONT_ONLY; | |
320 | buff[i] = 0; | |
321 | break; | |
322 | } | |
323 | } | |
324 | } | |
325 | ||
326 | return type; | |
327 | } | |
328 | ||
b0f1a59a | 329 | static void filter_build_regex(struct filter_pred *pred) |
1889d209 FW |
330 | { |
331 | struct regex *r = &pred->regex; | |
b0f1a59a LZ |
332 | char *search; |
333 | enum regex_type type = MATCH_FULL; | |
334 | int not = 0; | |
335 | ||
336 | if (pred->op == OP_GLOB) { | |
337 | type = filter_parse_regex(r->pattern, r->len, &search, ¬); | |
338 | r->len = strlen(search); | |
339 | memmove(r->pattern, search, r->len+1); | |
340 | } | |
1889d209 FW |
341 | |
342 | switch (type) { | |
343 | case MATCH_FULL: | |
344 | r->match = regex_match_full; | |
345 | break; | |
346 | case MATCH_FRONT_ONLY: | |
347 | r->match = regex_match_front; | |
348 | break; | |
349 | case MATCH_MIDDLE_ONLY: | |
350 | r->match = regex_match_middle; | |
351 | break; | |
352 | case MATCH_END_ONLY: | |
353 | r->match = regex_match_end; | |
354 | break; | |
355 | } | |
356 | ||
357 | pred->not ^= not; | |
1889d209 FW |
358 | } |
359 | ||
7ce7e424 | 360 | /* return 1 if event matches, 0 otherwise (discard) */ |
6fb2915d | 361 | int filter_match_preds(struct event_filter *filter, void *rec) |
7ce7e424 | 362 | { |
58d9a597 | 363 | int match = -1, top = 0, val1 = 0, val2 = 0; |
8b372562 | 364 | int stack[MAX_FILTER_PRED]; |
c9c53ca0 | 365 | struct filter_pred **preds; |
7ce7e424 | 366 | struct filter_pred *pred; |
6d54057d | 367 | int n_preds = ACCESS_ONCE(filter->n_preds); |
8b372562 | 368 | int i; |
7ce7e424 | 369 | |
6d54057d SR |
370 | /* no filter is considered a match */ |
371 | if (!n_preds) | |
372 | return 1; | |
373 | ||
c9c53ca0 SR |
374 | /* |
375 | * n_preds and filter->preds is protect with preemption disabled. | |
376 | */ | |
377 | preds = rcu_dereference_sched(filter->preds); | |
378 | ||
6d54057d | 379 | for (i = 0; i < n_preds; i++) { |
c9c53ca0 | 380 | pred = preds[i]; |
8b372562 | 381 | if (!pred->pop_n) { |
58d9a597 | 382 | match = pred->fn(pred, rec); |
8b372562 | 383 | stack[top++] = match; |
0a19e53c | 384 | continue; |
8b372562 TZ |
385 | } |
386 | if (pred->pop_n > top) { | |
387 | WARN_ON_ONCE(1); | |
388 | return 0; | |
389 | } | |
390 | val1 = stack[--top]; | |
391 | val2 = stack[--top]; | |
58d9a597 SR |
392 | switch (pred->op) { |
393 | case OP_AND: | |
394 | match = val1 && val2; | |
395 | break; | |
396 | case OP_OR: | |
397 | match = val1 || val2; | |
398 | break; | |
399 | default: | |
400 | WARN_ONCE(1, "filter op is not AND or OR"); | |
401 | } | |
8b372562 | 402 | stack[top++] = match; |
7ce7e424 TZ |
403 | } |
404 | ||
8b372562 | 405 | return stack[--top]; |
7ce7e424 | 406 | } |
17c873ec | 407 | EXPORT_SYMBOL_GPL(filter_match_preds); |
7ce7e424 | 408 | |
8b372562 | 409 | static void parse_error(struct filter_parse_state *ps, int err, int pos) |
7ce7e424 | 410 | { |
8b372562 TZ |
411 | ps->lasterr = err; |
412 | ps->lasterr_pos = pos; | |
413 | } | |
7ce7e424 | 414 | |
8b372562 TZ |
415 | static void remove_filter_string(struct event_filter *filter) |
416 | { | |
417 | kfree(filter->filter_string); | |
418 | filter->filter_string = NULL; | |
419 | } | |
420 | ||
421 | static int replace_filter_string(struct event_filter *filter, | |
422 | char *filter_string) | |
423 | { | |
424 | kfree(filter->filter_string); | |
425 | filter->filter_string = kstrdup(filter_string, GFP_KERNEL); | |
426 | if (!filter->filter_string) | |
427 | return -ENOMEM; | |
428 | ||
429 | return 0; | |
430 | } | |
431 | ||
432 | static int append_filter_string(struct event_filter *filter, | |
433 | char *string) | |
434 | { | |
435 | int newlen; | |
436 | char *new_filter_string; | |
437 | ||
438 | BUG_ON(!filter->filter_string); | |
439 | newlen = strlen(filter->filter_string) + strlen(string) + 1; | |
440 | new_filter_string = kmalloc(newlen, GFP_KERNEL); | |
441 | if (!new_filter_string) | |
442 | return -ENOMEM; | |
443 | ||
444 | strcpy(new_filter_string, filter->filter_string); | |
445 | strcat(new_filter_string, string); | |
446 | kfree(filter->filter_string); | |
447 | filter->filter_string = new_filter_string; | |
448 | ||
449 | return 0; | |
450 | } | |
451 | ||
452 | static void append_filter_err(struct filter_parse_state *ps, | |
453 | struct event_filter *filter) | |
454 | { | |
455 | int pos = ps->lasterr_pos; | |
456 | char *buf, *pbuf; | |
457 | ||
458 | buf = (char *)__get_free_page(GFP_TEMPORARY); | |
459 | if (!buf) | |
4bda2d51 | 460 | return; |
7ce7e424 | 461 | |
8b372562 TZ |
462 | append_filter_string(filter, "\n"); |
463 | memset(buf, ' ', PAGE_SIZE); | |
464 | if (pos > PAGE_SIZE - 128) | |
465 | pos = 0; | |
466 | buf[pos] = '^'; | |
467 | pbuf = &buf[pos] + 1; | |
468 | ||
469 | sprintf(pbuf, "\nparse_error: %s\n", err_text[ps->lasterr]); | |
470 | append_filter_string(filter, buf); | |
471 | free_page((unsigned long) buf); | |
7ce7e424 TZ |
472 | } |
473 | ||
8b372562 | 474 | void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s) |
ac1adc55 | 475 | { |
8b372562 TZ |
476 | struct event_filter *filter = call->filter; |
477 | ||
00e95830 | 478 | mutex_lock(&event_mutex); |
8e254c1d | 479 | if (filter && filter->filter_string) |
8b372562 TZ |
480 | trace_seq_printf(s, "%s\n", filter->filter_string); |
481 | else | |
482 | trace_seq_printf(s, "none\n"); | |
00e95830 | 483 | mutex_unlock(&event_mutex); |
ac1adc55 TZ |
484 | } |
485 | ||
8b372562 | 486 | void print_subsystem_event_filter(struct event_subsystem *system, |
ac1adc55 TZ |
487 | struct trace_seq *s) |
488 | { | |
8b372562 TZ |
489 | struct event_filter *filter = system->filter; |
490 | ||
00e95830 | 491 | mutex_lock(&event_mutex); |
8e254c1d | 492 | if (filter && filter->filter_string) |
8b372562 TZ |
493 | trace_seq_printf(s, "%s\n", filter->filter_string); |
494 | else | |
495 | trace_seq_printf(s, "none\n"); | |
00e95830 | 496 | mutex_unlock(&event_mutex); |
ac1adc55 TZ |
497 | } |
498 | ||
7ce7e424 | 499 | static struct ftrace_event_field * |
8728fe50 | 500 | __find_event_field(struct list_head *head, char *name) |
7ce7e424 | 501 | { |
1fc2d5c1 | 502 | struct ftrace_event_field *field; |
7ce7e424 | 503 | |
2e33af02 | 504 | list_for_each_entry(field, head, link) { |
7ce7e424 TZ |
505 | if (!strcmp(field->name, name)) |
506 | return field; | |
507 | } | |
508 | ||
509 | return NULL; | |
510 | } | |
511 | ||
8728fe50 LZ |
512 | static struct ftrace_event_field * |
513 | find_event_field(struct ftrace_event_call *call, char *name) | |
514 | { | |
515 | struct ftrace_event_field *field; | |
516 | struct list_head *head; | |
517 | ||
518 | field = __find_event_field(&ftrace_common_fields, name); | |
519 | if (field) | |
520 | return field; | |
521 | ||
522 | head = trace_get_fields(call); | |
523 | return __find_event_field(head, name); | |
524 | } | |
525 | ||
8b372562 | 526 | static void filter_free_pred(struct filter_pred *pred) |
7ce7e424 TZ |
527 | { |
528 | if (!pred) | |
529 | return; | |
530 | ||
531 | kfree(pred->field_name); | |
7ce7e424 TZ |
532 | kfree(pred); |
533 | } | |
534 | ||
0a19e53c TZ |
535 | static void filter_clear_pred(struct filter_pred *pred) |
536 | { | |
537 | kfree(pred->field_name); | |
538 | pred->field_name = NULL; | |
1889d209 | 539 | pred->regex.len = 0; |
0a19e53c TZ |
540 | } |
541 | ||
542 | static int filter_set_pred(struct filter_pred *dest, | |
543 | struct filter_pred *src, | |
544 | filter_pred_fn_t fn) | |
545 | { | |
546 | *dest = *src; | |
8b372562 TZ |
547 | if (src->field_name) { |
548 | dest->field_name = kstrdup(src->field_name, GFP_KERNEL); | |
549 | if (!dest->field_name) | |
550 | return -ENOMEM; | |
551 | } | |
0a19e53c TZ |
552 | dest->fn = fn; |
553 | ||
554 | return 0; | |
555 | } | |
556 | ||
c9c53ca0 SR |
557 | static void __free_preds(struct event_filter *filter) |
558 | { | |
559 | int i; | |
560 | ||
561 | if (filter->preds) { | |
562 | for (i = 0; i < filter->a_preds; i++) { | |
563 | if (filter->preds[i]) | |
564 | filter_free_pred(filter->preds[i]); | |
565 | } | |
566 | kfree(filter->preds); | |
567 | filter->preds = NULL; | |
568 | } | |
569 | filter->a_preds = 0; | |
570 | filter->n_preds = 0; | |
571 | } | |
572 | ||
8b372562 | 573 | static void filter_disable_preds(struct ftrace_event_call *call) |
7ce7e424 | 574 | { |
30e673b2 | 575 | struct event_filter *filter = call->filter; |
7ce7e424 TZ |
576 | int i; |
577 | ||
553552ce | 578 | call->flags &= ~TRACE_EVENT_FL_FILTERED; |
c9c53ca0 SR |
579 | if (filter->preds) { |
580 | for (i = 0; i < filter->n_preds; i++) | |
581 | filter->preds[i]->fn = filter_pred_none; | |
582 | } | |
30e673b2 | 583 | filter->n_preds = 0; |
0a19e53c TZ |
584 | } |
585 | ||
c9c53ca0 | 586 | static void __free_filter(struct event_filter *filter) |
2df75e41 | 587 | { |
8e254c1d LZ |
588 | if (!filter) |
589 | return; | |
590 | ||
c9c53ca0 | 591 | __free_preds(filter); |
57be8887 | 592 | kfree(filter->filter_string); |
2df75e41 | 593 | kfree(filter); |
6fb2915d LZ |
594 | } |
595 | ||
596 | void destroy_preds(struct ftrace_event_call *call) | |
597 | { | |
c9c53ca0 | 598 | __free_filter(call->filter); |
2df75e41 | 599 | call->filter = NULL; |
553552ce | 600 | call->flags &= ~TRACE_EVENT_FL_FILTERED; |
2df75e41 LZ |
601 | } |
602 | ||
c9c53ca0 | 603 | static struct event_filter *__alloc_filter(void) |
0a19e53c | 604 | { |
30e673b2 | 605 | struct event_filter *filter; |
0a19e53c | 606 | |
6fb2915d LZ |
607 | filter = kzalloc(sizeof(*filter), GFP_KERNEL); |
608 | if (!filter) | |
609 | return ERR_PTR(-ENOMEM); | |
0a19e53c | 610 | |
30e673b2 TZ |
611 | filter->n_preds = 0; |
612 | ||
c9c53ca0 SR |
613 | return filter; |
614 | } | |
615 | ||
616 | static int __alloc_preds(struct event_filter *filter, int n_preds) | |
617 | { | |
618 | struct filter_pred *pred; | |
619 | int i; | |
620 | ||
621 | if (filter->preds) { | |
622 | if (filter->a_preds < n_preds) { | |
623 | /* We need to reallocate */ | |
624 | filter->n_preds = 0; | |
625 | /* | |
626 | * It is possible that the filter is currently | |
627 | * being used. We need to zero out the number | |
628 | * of preds, wait on preemption and then free | |
629 | * the preds. | |
630 | */ | |
631 | synchronize_sched(); | |
632 | __free_preds(filter); | |
633 | } | |
634 | } | |
635 | ||
636 | if (!filter->preds) { | |
637 | filter->preds = | |
638 | kzalloc(sizeof(*filter->preds) * n_preds, GFP_KERNEL); | |
639 | filter->a_preds = n_preds; | |
640 | } | |
30e673b2 | 641 | if (!filter->preds) |
c9c53ca0 SR |
642 | return -ENOMEM; |
643 | ||
644 | if (WARN_ON(filter->a_preds < n_preds)) | |
645 | return -EINVAL; | |
30e673b2 | 646 | |
c9c53ca0 SR |
647 | for (i = 0; i < n_preds; i++) { |
648 | pred = filter->preds[i]; | |
649 | if (!pred) | |
650 | pred = kzalloc(sizeof(*pred), GFP_KERNEL); | |
0a19e53c TZ |
651 | if (!pred) |
652 | goto oom; | |
653 | pred->fn = filter_pred_none; | |
30e673b2 | 654 | filter->preds[i] = pred; |
0a19e53c TZ |
655 | } |
656 | ||
c9c53ca0 SR |
657 | return 0; |
658 | oom: | |
6fb2915d | 659 | __free_preds(filter); |
c9c53ca0 | 660 | return -ENOMEM; |
6fb2915d LZ |
661 | } |
662 | ||
c9c53ca0 | 663 | static int init_filter(struct ftrace_event_call *call) |
6fb2915d LZ |
664 | { |
665 | if (call->filter) | |
666 | return 0; | |
667 | ||
553552ce | 668 | call->flags &= ~TRACE_EVENT_FL_FILTERED; |
c9c53ca0 | 669 | call->filter = __alloc_filter(); |
6fb2915d LZ |
670 | if (IS_ERR(call->filter)) |
671 | return PTR_ERR(call->filter); | |
0a19e53c | 672 | |
6fb2915d | 673 | return 0; |
7ce7e424 | 674 | } |
8e254c1d LZ |
675 | |
676 | static int init_subsystem_preds(struct event_subsystem *system) | |
677 | { | |
678 | struct ftrace_event_call *call; | |
679 | int err; | |
680 | ||
681 | list_for_each_entry(call, &ftrace_events, list) { | |
8f082018 | 682 | if (strcmp(call->class->system, system->name) != 0) |
8e254c1d LZ |
683 | continue; |
684 | ||
c9c53ca0 | 685 | err = init_filter(call); |
c58b4321 LZ |
686 | if (err) |
687 | return err; | |
8e254c1d LZ |
688 | } |
689 | ||
690 | return 0; | |
691 | } | |
7ce7e424 | 692 | |
fce29d15 | 693 | static void filter_free_subsystem_preds(struct event_subsystem *system) |
cfb180f3 | 694 | { |
a59fd602 | 695 | struct ftrace_event_call *call; |
cfb180f3 | 696 | |
a59fd602 | 697 | list_for_each_entry(call, &ftrace_events, list) { |
8f082018 | 698 | if (strcmp(call->class->system, system->name) != 0) |
8e254c1d LZ |
699 | continue; |
700 | ||
8e254c1d LZ |
701 | filter_disable_preds(call); |
702 | remove_filter_string(call->filter); | |
cfb180f3 TZ |
703 | } |
704 | } | |
705 | ||
8b372562 TZ |
706 | static int filter_add_pred_fn(struct filter_parse_state *ps, |
707 | struct ftrace_event_call *call, | |
6fb2915d | 708 | struct event_filter *filter, |
ac1adc55 TZ |
709 | struct filter_pred *pred, |
710 | filter_pred_fn_t fn) | |
7ce7e424 | 711 | { |
0a19e53c | 712 | int idx, err; |
7ce7e424 | 713 | |
c9c53ca0 | 714 | if (WARN_ON(filter->n_preds == filter->a_preds)) { |
8b372562 | 715 | parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0); |
0a19e53c | 716 | return -ENOSPC; |
8b372562 | 717 | } |
7ce7e424 | 718 | |
30e673b2 TZ |
719 | idx = filter->n_preds; |
720 | filter_clear_pred(filter->preds[idx]); | |
721 | err = filter_set_pred(filter->preds[idx], pred, fn); | |
0a19e53c TZ |
722 | if (err) |
723 | return err; | |
724 | ||
30e673b2 | 725 | filter->n_preds++; |
7ce7e424 | 726 | |
0a19e53c | 727 | return 0; |
7ce7e424 TZ |
728 | } |
729 | ||
aa38e9fc | 730 | int filter_assign_type(const char *type) |
7ce7e424 | 731 | { |
7fcb7c47 LZ |
732 | if (strstr(type, "__data_loc") && strstr(type, "char")) |
733 | return FILTER_DYN_STRING; | |
734 | ||
7ce7e424 | 735 | if (strchr(type, '[') && strstr(type, "char")) |
e8808c10 FW |
736 | return FILTER_STATIC_STRING; |
737 | ||
aa38e9fc LZ |
738 | return FILTER_OTHER; |
739 | } | |
740 | ||
741 | static bool is_string_field(struct ftrace_event_field *field) | |
742 | { | |
743 | return field->filter_type == FILTER_DYN_STRING || | |
87a342f5 LZ |
744 | field->filter_type == FILTER_STATIC_STRING || |
745 | field->filter_type == FILTER_PTR_STRING; | |
7ce7e424 TZ |
746 | } |
747 | ||
8b372562 TZ |
748 | static int is_legal_op(struct ftrace_event_field *field, int op) |
749 | { | |
b0f1a59a LZ |
750 | if (is_string_field(field) && |
751 | (op != OP_EQ && op != OP_NE && op != OP_GLOB)) | |
752 | return 0; | |
753 | if (!is_string_field(field) && op == OP_GLOB) | |
8b372562 TZ |
754 | return 0; |
755 | ||
756 | return 1; | |
757 | } | |
758 | ||
759 | static filter_pred_fn_t select_comparison_fn(int op, int field_size, | |
760 | int field_is_signed) | |
761 | { | |
762 | filter_pred_fn_t fn = NULL; | |
763 | ||
764 | switch (field_size) { | |
765 | case 8: | |
766 | if (op == OP_EQ || op == OP_NE) | |
767 | fn = filter_pred_64; | |
768 | else if (field_is_signed) | |
769 | fn = filter_pred_s64; | |
770 | else | |
771 | fn = filter_pred_u64; | |
772 | break; | |
773 | case 4: | |
774 | if (op == OP_EQ || op == OP_NE) | |
775 | fn = filter_pred_32; | |
776 | else if (field_is_signed) | |
777 | fn = filter_pred_s32; | |
778 | else | |
779 | fn = filter_pred_u32; | |
780 | break; | |
781 | case 2: | |
782 | if (op == OP_EQ || op == OP_NE) | |
783 | fn = filter_pred_16; | |
784 | else if (field_is_signed) | |
785 | fn = filter_pred_s16; | |
786 | else | |
787 | fn = filter_pred_u16; | |
788 | break; | |
789 | case 1: | |
790 | if (op == OP_EQ || op == OP_NE) | |
791 | fn = filter_pred_8; | |
792 | else if (field_is_signed) | |
793 | fn = filter_pred_s8; | |
794 | else | |
795 | fn = filter_pred_u8; | |
796 | break; | |
797 | } | |
798 | ||
799 | return fn; | |
800 | } | |
801 | ||
802 | static int filter_add_pred(struct filter_parse_state *ps, | |
803 | struct ftrace_event_call *call, | |
6fb2915d | 804 | struct event_filter *filter, |
1f9963cb LZ |
805 | struct filter_pred *pred, |
806 | bool dry_run) | |
7ce7e424 TZ |
807 | { |
808 | struct ftrace_event_field *field; | |
0a19e53c | 809 | filter_pred_fn_t fn; |
f66578a7 | 810 | unsigned long long val; |
5e4904cb | 811 | int ret; |
7ce7e424 | 812 | |
58d9a597 | 813 | fn = pred->fn = filter_pred_none; |
8b372562 TZ |
814 | |
815 | if (pred->op == OP_AND) { | |
816 | pred->pop_n = 2; | |
1f9963cb | 817 | goto add_pred_fn; |
8b372562 TZ |
818 | } else if (pred->op == OP_OR) { |
819 | pred->pop_n = 2; | |
1f9963cb | 820 | goto add_pred_fn; |
8b372562 TZ |
821 | } |
822 | ||
7ce7e424 | 823 | field = find_event_field(call, pred->field_name); |
8b372562 TZ |
824 | if (!field) { |
825 | parse_error(ps, FILT_ERR_FIELD_NOT_FOUND, 0); | |
7ce7e424 | 826 | return -EINVAL; |
8b372562 | 827 | } |
7ce7e424 TZ |
828 | |
829 | pred->offset = field->offset; | |
830 | ||
8b372562 TZ |
831 | if (!is_legal_op(field, pred->op)) { |
832 | parse_error(ps, FILT_ERR_ILLEGAL_FIELD_OP, 0); | |
833 | return -EINVAL; | |
834 | } | |
835 | ||
aa38e9fc | 836 | if (is_string_field(field)) { |
b0f1a59a | 837 | filter_build_regex(pred); |
87a342f5 | 838 | |
1889d209 | 839 | if (field->filter_type == FILTER_STATIC_STRING) { |
e8808c10 | 840 | fn = filter_pred_string; |
1889d209 FW |
841 | pred->regex.field_len = field->size; |
842 | } else if (field->filter_type == FILTER_DYN_STRING) | |
b0f1a59a | 843 | fn = filter_pred_strloc; |
16da27a8 | 844 | else |
87a342f5 | 845 | fn = filter_pred_pchar; |
9f58a159 | 846 | } else { |
5e4904cb | 847 | if (field->is_signed) |
1889d209 | 848 | ret = strict_strtoll(pred->regex.pattern, 0, &val); |
5e4904cb | 849 | else |
1889d209 | 850 | ret = strict_strtoull(pred->regex.pattern, 0, &val); |
5e4904cb | 851 | if (ret) { |
8b372562 | 852 | parse_error(ps, FILT_ERR_ILLEGAL_INTVAL, 0); |
9f58a159 | 853 | return -EINVAL; |
8b372562 | 854 | } |
f66578a7 | 855 | pred->val = val; |
7ce7e424 | 856 | |
1f9963cb LZ |
857 | fn = select_comparison_fn(pred->op, field->size, |
858 | field->is_signed); | |
859 | if (!fn) { | |
860 | parse_error(ps, FILT_ERR_INVALID_OP, 0); | |
861 | return -EINVAL; | |
862 | } | |
7ce7e424 TZ |
863 | } |
864 | ||
8b372562 TZ |
865 | if (pred->op == OP_NE) |
866 | pred->not = 1; | |
ac1adc55 | 867 | |
1f9963cb LZ |
868 | add_pred_fn: |
869 | if (!dry_run) | |
6fb2915d | 870 | return filter_add_pred_fn(ps, call, filter, pred, fn); |
1f9963cb | 871 | return 0; |
cfb180f3 TZ |
872 | } |
873 | ||
8b372562 TZ |
874 | static void parse_init(struct filter_parse_state *ps, |
875 | struct filter_op *ops, | |
876 | char *infix_string) | |
877 | { | |
878 | memset(ps, '\0', sizeof(*ps)); | |
879 | ||
880 | ps->infix.string = infix_string; | |
881 | ps->infix.cnt = strlen(infix_string); | |
882 | ps->ops = ops; | |
883 | ||
884 | INIT_LIST_HEAD(&ps->opstack); | |
885 | INIT_LIST_HEAD(&ps->postfix); | |
886 | } | |
887 | ||
888 | static char infix_next(struct filter_parse_state *ps) | |
889 | { | |
890 | ps->infix.cnt--; | |
891 | ||
892 | return ps->infix.string[ps->infix.tail++]; | |
893 | } | |
894 | ||
895 | static char infix_peek(struct filter_parse_state *ps) | |
896 | { | |
897 | if (ps->infix.tail == strlen(ps->infix.string)) | |
898 | return 0; | |
899 | ||
900 | return ps->infix.string[ps->infix.tail]; | |
901 | } | |
902 | ||
903 | static void infix_advance(struct filter_parse_state *ps) | |
904 | { | |
905 | ps->infix.cnt--; | |
906 | ps->infix.tail++; | |
907 | } | |
908 | ||
909 | static inline int is_precedence_lower(struct filter_parse_state *ps, | |
910 | int a, int b) | |
911 | { | |
912 | return ps->ops[a].precedence < ps->ops[b].precedence; | |
913 | } | |
914 | ||
915 | static inline int is_op_char(struct filter_parse_state *ps, char c) | |
916 | { | |
917 | int i; | |
918 | ||
919 | for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) { | |
920 | if (ps->ops[i].string[0] == c) | |
921 | return 1; | |
922 | } | |
c4cff064 | 923 | |
0a19e53c | 924 | return 0; |
cfb180f3 TZ |
925 | } |
926 | ||
8b372562 TZ |
927 | static int infix_get_op(struct filter_parse_state *ps, char firstc) |
928 | { | |
929 | char nextc = infix_peek(ps); | |
930 | char opstr[3]; | |
931 | int i; | |
932 | ||
933 | opstr[0] = firstc; | |
934 | opstr[1] = nextc; | |
935 | opstr[2] = '\0'; | |
936 | ||
937 | for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) { | |
938 | if (!strcmp(opstr, ps->ops[i].string)) { | |
939 | infix_advance(ps); | |
940 | return ps->ops[i].id; | |
7ce7e424 | 941 | } |
8b372562 TZ |
942 | } |
943 | ||
944 | opstr[1] = '\0'; | |
945 | ||
946 | for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) { | |
947 | if (!strcmp(opstr, ps->ops[i].string)) | |
948 | return ps->ops[i].id; | |
949 | } | |
950 | ||
951 | return OP_NONE; | |
952 | } | |
953 | ||
954 | static inline void clear_operand_string(struct filter_parse_state *ps) | |
955 | { | |
956 | memset(ps->operand.string, '\0', MAX_FILTER_STR_VAL); | |
957 | ps->operand.tail = 0; | |
958 | } | |
959 | ||
960 | static inline int append_operand_char(struct filter_parse_state *ps, char c) | |
961 | { | |
5872144f | 962 | if (ps->operand.tail == MAX_FILTER_STR_VAL - 1) |
8b372562 TZ |
963 | return -EINVAL; |
964 | ||
965 | ps->operand.string[ps->operand.tail++] = c; | |
966 | ||
967 | return 0; | |
968 | } | |
969 | ||
970 | static int filter_opstack_push(struct filter_parse_state *ps, int op) | |
971 | { | |
972 | struct opstack_op *opstack_op; | |
973 | ||
974 | opstack_op = kmalloc(sizeof(*opstack_op), GFP_KERNEL); | |
975 | if (!opstack_op) | |
976 | return -ENOMEM; | |
977 | ||
978 | opstack_op->op = op; | |
979 | list_add(&opstack_op->list, &ps->opstack); | |
980 | ||
981 | return 0; | |
982 | } | |
983 | ||
984 | static int filter_opstack_empty(struct filter_parse_state *ps) | |
985 | { | |
986 | return list_empty(&ps->opstack); | |
987 | } | |
988 | ||
989 | static int filter_opstack_top(struct filter_parse_state *ps) | |
990 | { | |
991 | struct opstack_op *opstack_op; | |
992 | ||
993 | if (filter_opstack_empty(ps)) | |
994 | return OP_NONE; | |
995 | ||
996 | opstack_op = list_first_entry(&ps->opstack, struct opstack_op, list); | |
997 | ||
998 | return opstack_op->op; | |
999 | } | |
1000 | ||
1001 | static int filter_opstack_pop(struct filter_parse_state *ps) | |
1002 | { | |
1003 | struct opstack_op *opstack_op; | |
1004 | int op; | |
1005 | ||
1006 | if (filter_opstack_empty(ps)) | |
1007 | return OP_NONE; | |
1008 | ||
1009 | opstack_op = list_first_entry(&ps->opstack, struct opstack_op, list); | |
1010 | op = opstack_op->op; | |
1011 | list_del(&opstack_op->list); | |
1012 | ||
1013 | kfree(opstack_op); | |
1014 | ||
1015 | return op; | |
1016 | } | |
1017 | ||
1018 | static void filter_opstack_clear(struct filter_parse_state *ps) | |
1019 | { | |
1020 | while (!filter_opstack_empty(ps)) | |
1021 | filter_opstack_pop(ps); | |
1022 | } | |
1023 | ||
1024 | static char *curr_operand(struct filter_parse_state *ps) | |
1025 | { | |
1026 | return ps->operand.string; | |
1027 | } | |
1028 | ||
1029 | static int postfix_append_operand(struct filter_parse_state *ps, char *operand) | |
1030 | { | |
1031 | struct postfix_elt *elt; | |
1032 | ||
1033 | elt = kmalloc(sizeof(*elt), GFP_KERNEL); | |
1034 | if (!elt) | |
1035 | return -ENOMEM; | |
1036 | ||
1037 | elt->op = OP_NONE; | |
1038 | elt->operand = kstrdup(operand, GFP_KERNEL); | |
1039 | if (!elt->operand) { | |
1040 | kfree(elt); | |
1041 | return -ENOMEM; | |
1042 | } | |
1043 | ||
1044 | list_add_tail(&elt->list, &ps->postfix); | |
1045 | ||
1046 | return 0; | |
1047 | } | |
1048 | ||
1049 | static int postfix_append_op(struct filter_parse_state *ps, int op) | |
1050 | { | |
1051 | struct postfix_elt *elt; | |
1052 | ||
1053 | elt = kmalloc(sizeof(*elt), GFP_KERNEL); | |
1054 | if (!elt) | |
1055 | return -ENOMEM; | |
1056 | ||
1057 | elt->op = op; | |
1058 | elt->operand = NULL; | |
1059 | ||
1060 | list_add_tail(&elt->list, &ps->postfix); | |
1061 | ||
1062 | return 0; | |
1063 | } | |
1064 | ||
1065 | static void postfix_clear(struct filter_parse_state *ps) | |
1066 | { | |
1067 | struct postfix_elt *elt; | |
1068 | ||
1069 | while (!list_empty(&ps->postfix)) { | |
1070 | elt = list_first_entry(&ps->postfix, struct postfix_elt, list); | |
8b372562 | 1071 | list_del(&elt->list); |
8ad80731 LZ |
1072 | kfree(elt->operand); |
1073 | kfree(elt); | |
8b372562 TZ |
1074 | } |
1075 | } | |
1076 | ||
1077 | static int filter_parse(struct filter_parse_state *ps) | |
1078 | { | |
5928c3cc | 1079 | int in_string = 0; |
8b372562 TZ |
1080 | int op, top_op; |
1081 | char ch; | |
1082 | ||
1083 | while ((ch = infix_next(ps))) { | |
5928c3cc FW |
1084 | if (ch == '"') { |
1085 | in_string ^= 1; | |
1086 | continue; | |
1087 | } | |
1088 | ||
1089 | if (in_string) | |
1090 | goto parse_operand; | |
1091 | ||
8b372562 TZ |
1092 | if (isspace(ch)) |
1093 | continue; | |
1094 | ||
1095 | if (is_op_char(ps, ch)) { | |
1096 | op = infix_get_op(ps, ch); | |
1097 | if (op == OP_NONE) { | |
1098 | parse_error(ps, FILT_ERR_INVALID_OP, 0); | |
7ce7e424 TZ |
1099 | return -EINVAL; |
1100 | } | |
8b372562 TZ |
1101 | |
1102 | if (strlen(curr_operand(ps))) { | |
1103 | postfix_append_operand(ps, curr_operand(ps)); | |
1104 | clear_operand_string(ps); | |
1105 | } | |
1106 | ||
1107 | while (!filter_opstack_empty(ps)) { | |
1108 | top_op = filter_opstack_top(ps); | |
1109 | if (!is_precedence_lower(ps, top_op, op)) { | |
1110 | top_op = filter_opstack_pop(ps); | |
1111 | postfix_append_op(ps, top_op); | |
1112 | continue; | |
1113 | } | |
1114 | break; | |
1115 | } | |
1116 | ||
1117 | filter_opstack_push(ps, op); | |
7ce7e424 TZ |
1118 | continue; |
1119 | } | |
8b372562 TZ |
1120 | |
1121 | if (ch == '(') { | |
1122 | filter_opstack_push(ps, OP_OPEN_PAREN); | |
1123 | continue; | |
1124 | } | |
1125 | ||
1126 | if (ch == ')') { | |
1127 | if (strlen(curr_operand(ps))) { | |
1128 | postfix_append_operand(ps, curr_operand(ps)); | |
1129 | clear_operand_string(ps); | |
1130 | } | |
1131 | ||
1132 | top_op = filter_opstack_pop(ps); | |
1133 | while (top_op != OP_NONE) { | |
1134 | if (top_op == OP_OPEN_PAREN) | |
1135 | break; | |
1136 | postfix_append_op(ps, top_op); | |
1137 | top_op = filter_opstack_pop(ps); | |
1138 | } | |
1139 | if (top_op == OP_NONE) { | |
1140 | parse_error(ps, FILT_ERR_UNBALANCED_PAREN, 0); | |
1141 | return -EINVAL; | |
7ce7e424 | 1142 | } |
7ce7e424 TZ |
1143 | continue; |
1144 | } | |
5928c3cc | 1145 | parse_operand: |
8b372562 TZ |
1146 | if (append_operand_char(ps, ch)) { |
1147 | parse_error(ps, FILT_ERR_OPERAND_TOO_LONG, 0); | |
1148 | return -EINVAL; | |
1149 | } | |
1150 | } | |
1151 | ||
1152 | if (strlen(curr_operand(ps))) | |
1153 | postfix_append_operand(ps, curr_operand(ps)); | |
1154 | ||
1155 | while (!filter_opstack_empty(ps)) { | |
1156 | top_op = filter_opstack_pop(ps); | |
1157 | if (top_op == OP_NONE) | |
1158 | break; | |
1159 | if (top_op == OP_OPEN_PAREN) { | |
1160 | parse_error(ps, FILT_ERR_UNBALANCED_PAREN, 0); | |
1161 | return -EINVAL; | |
1162 | } | |
1163 | postfix_append_op(ps, top_op); | |
1164 | } | |
1165 | ||
1166 | return 0; | |
1167 | } | |
1168 | ||
1169 | static struct filter_pred *create_pred(int op, char *operand1, char *operand2) | |
1170 | { | |
1171 | struct filter_pred *pred; | |
1172 | ||
1173 | pred = kzalloc(sizeof(*pred), GFP_KERNEL); | |
1174 | if (!pred) | |
1175 | return NULL; | |
1176 | ||
1177 | pred->field_name = kstrdup(operand1, GFP_KERNEL); | |
1178 | if (!pred->field_name) { | |
1179 | kfree(pred); | |
1180 | return NULL; | |
1181 | } | |
1182 | ||
1889d209 FW |
1183 | strcpy(pred->regex.pattern, operand2); |
1184 | pred->regex.len = strlen(pred->regex.pattern); | |
8b372562 TZ |
1185 | |
1186 | pred->op = op; | |
1187 | ||
1188 | return pred; | |
1189 | } | |
1190 | ||
1191 | static struct filter_pred *create_logical_pred(int op) | |
1192 | { | |
1193 | struct filter_pred *pred; | |
1194 | ||
1195 | pred = kzalloc(sizeof(*pred), GFP_KERNEL); | |
1196 | if (!pred) | |
1197 | return NULL; | |
1198 | ||
1199 | pred->op = op; | |
1200 | ||
1201 | return pred; | |
1202 | } | |
1203 | ||
1204 | static int check_preds(struct filter_parse_state *ps) | |
1205 | { | |
1206 | int n_normal_preds = 0, n_logical_preds = 0; | |
1207 | struct postfix_elt *elt; | |
1208 | ||
1209 | list_for_each_entry(elt, &ps->postfix, list) { | |
1210 | if (elt->op == OP_NONE) | |
1211 | continue; | |
1212 | ||
1213 | if (elt->op == OP_AND || elt->op == OP_OR) { | |
1214 | n_logical_preds++; | |
1215 | continue; | |
7ce7e424 | 1216 | } |
8b372562 | 1217 | n_normal_preds++; |
7ce7e424 TZ |
1218 | } |
1219 | ||
8b372562 TZ |
1220 | if (!n_normal_preds || n_logical_preds >= n_normal_preds) { |
1221 | parse_error(ps, FILT_ERR_INVALID_FILTER, 0); | |
bcabd91c LZ |
1222 | return -EINVAL; |
1223 | } | |
1224 | ||
8b372562 TZ |
1225 | return 0; |
1226 | } | |
f66578a7 | 1227 | |
c9c53ca0 SR |
1228 | static int count_preds(struct filter_parse_state *ps) |
1229 | { | |
1230 | struct postfix_elt *elt; | |
1231 | int n_preds = 0; | |
1232 | ||
1233 | list_for_each_entry(elt, &ps->postfix, list) { | |
1234 | if (elt->op == OP_NONE) | |
1235 | continue; | |
1236 | n_preds++; | |
1237 | } | |
1238 | ||
1239 | return n_preds; | |
1240 | } | |
1241 | ||
fce29d15 | 1242 | static int replace_preds(struct ftrace_event_call *call, |
6fb2915d | 1243 | struct event_filter *filter, |
8b372562 | 1244 | struct filter_parse_state *ps, |
1f9963cb LZ |
1245 | char *filter_string, |
1246 | bool dry_run) | |
8b372562 TZ |
1247 | { |
1248 | char *operand1 = NULL, *operand2 = NULL; | |
1249 | struct filter_pred *pred; | |
1250 | struct postfix_elt *elt; | |
1251 | int err; | |
1f9963cb | 1252 | int n_preds = 0; |
8b372562 | 1253 | |
c9c53ca0 SR |
1254 | n_preds = count_preds(ps); |
1255 | if (n_preds >= MAX_FILTER_PRED) { | |
1256 | parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0); | |
1257 | return -ENOSPC; | |
1258 | } | |
1259 | ||
8b372562 TZ |
1260 | err = check_preds(ps); |
1261 | if (err) | |
1262 | return err; | |
1263 | ||
c9c53ca0 SR |
1264 | if (!dry_run) { |
1265 | err = __alloc_preds(filter, n_preds); | |
1266 | if (err) | |
1267 | return err; | |
1268 | } | |
1269 | ||
1270 | n_preds = 0; | |
8b372562 TZ |
1271 | list_for_each_entry(elt, &ps->postfix, list) { |
1272 | if (elt->op == OP_NONE) { | |
1273 | if (!operand1) | |
1274 | operand1 = elt->operand; | |
1275 | else if (!operand2) | |
1276 | operand2 = elt->operand; | |
1277 | else { | |
1278 | parse_error(ps, FILT_ERR_TOO_MANY_OPERANDS, 0); | |
1279 | return -EINVAL; | |
1280 | } | |
1281 | continue; | |
1282 | } | |
1283 | ||
c9c53ca0 | 1284 | if (WARN_ON(n_preds++ == MAX_FILTER_PRED)) { |
1f9963cb LZ |
1285 | parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0); |
1286 | return -ENOSPC; | |
1287 | } | |
1288 | ||
8b372562 TZ |
1289 | if (elt->op == OP_AND || elt->op == OP_OR) { |
1290 | pred = create_logical_pred(elt->op); | |
1f9963cb | 1291 | goto add_pred; |
8b372562 TZ |
1292 | } |
1293 | ||
1294 | if (!operand1 || !operand2) { | |
1295 | parse_error(ps, FILT_ERR_MISSING_FIELD, 0); | |
1296 | return -EINVAL; | |
1297 | } | |
1298 | ||
1299 | pred = create_pred(elt->op, operand1, operand2); | |
1f9963cb | 1300 | add_pred: |
fb82ad71 TZ |
1301 | if (!pred) |
1302 | return -ENOMEM; | |
6fb2915d | 1303 | err = filter_add_pred(ps, call, filter, pred, dry_run); |
c5cb1836 | 1304 | filter_free_pred(pred); |
8b372562 TZ |
1305 | if (err) |
1306 | return err; | |
1307 | ||
1308 | operand1 = operand2 = NULL; | |
1309 | } | |
7ce7e424 | 1310 | |
7ce7e424 TZ |
1311 | return 0; |
1312 | } | |
1313 | ||
fce29d15 LZ |
1314 | static int replace_system_preds(struct event_subsystem *system, |
1315 | struct filter_parse_state *ps, | |
1316 | char *filter_string) | |
1317 | { | |
1318 | struct ftrace_event_call *call; | |
fce29d15 | 1319 | bool fail = true; |
a66abe7f | 1320 | int err; |
fce29d15 LZ |
1321 | |
1322 | list_for_each_entry(call, &ftrace_events, list) { | |
3ed67776 | 1323 | struct event_filter *filter = call->filter; |
fce29d15 | 1324 | |
8f082018 | 1325 | if (strcmp(call->class->system, system->name) != 0) |
fce29d15 LZ |
1326 | continue; |
1327 | ||
1328 | /* try to see if the filter can be applied */ | |
6fb2915d | 1329 | err = replace_preds(call, filter, ps, filter_string, true); |
fce29d15 LZ |
1330 | if (err) |
1331 | continue; | |
1332 | ||
1333 | /* really apply the filter */ | |
1334 | filter_disable_preds(call); | |
6fb2915d | 1335 | err = replace_preds(call, filter, ps, filter_string, false); |
fce29d15 LZ |
1336 | if (err) |
1337 | filter_disable_preds(call); | |
6fb2915d | 1338 | else { |
553552ce | 1339 | call->flags |= TRACE_EVENT_FL_FILTERED; |
6fb2915d LZ |
1340 | replace_filter_string(filter, filter_string); |
1341 | } | |
fce29d15 LZ |
1342 | fail = false; |
1343 | } | |
1344 | ||
1345 | if (fail) { | |
1346 | parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0); | |
a66abe7f | 1347 | return -EINVAL; |
fce29d15 LZ |
1348 | } |
1349 | return 0; | |
1350 | } | |
1351 | ||
8b372562 TZ |
1352 | int apply_event_filter(struct ftrace_event_call *call, char *filter_string) |
1353 | { | |
1354 | int err; | |
8b372562 TZ |
1355 | struct filter_parse_state *ps; |
1356 | ||
00e95830 | 1357 | mutex_lock(&event_mutex); |
8b372562 | 1358 | |
c9c53ca0 | 1359 | err = init_filter(call); |
8e254c1d LZ |
1360 | if (err) |
1361 | goto out_unlock; | |
1362 | ||
8b372562 TZ |
1363 | if (!strcmp(strstrip(filter_string), "0")) { |
1364 | filter_disable_preds(call); | |
1365 | remove_filter_string(call->filter); | |
a66abe7f | 1366 | goto out_unlock; |
8b372562 TZ |
1367 | } |
1368 | ||
8cd995b6 | 1369 | err = -ENOMEM; |
8b372562 TZ |
1370 | ps = kzalloc(sizeof(*ps), GFP_KERNEL); |
1371 | if (!ps) | |
8cd995b6 | 1372 | goto out_unlock; |
8b372562 TZ |
1373 | |
1374 | filter_disable_preds(call); | |
1375 | replace_filter_string(call->filter, filter_string); | |
1376 | ||
1377 | parse_init(ps, filter_ops, filter_string); | |
1378 | err = filter_parse(ps); | |
1379 | if (err) { | |
1380 | append_filter_err(ps, call->filter); | |
1381 | goto out; | |
1382 | } | |
1383 | ||
6fb2915d | 1384 | err = replace_preds(call, call->filter, ps, filter_string, false); |
8b372562 TZ |
1385 | if (err) |
1386 | append_filter_err(ps, call->filter); | |
6fb2915d | 1387 | else |
553552ce | 1388 | call->flags |= TRACE_EVENT_FL_FILTERED; |
8b372562 TZ |
1389 | out: |
1390 | filter_opstack_clear(ps); | |
1391 | postfix_clear(ps); | |
1392 | kfree(ps); | |
8cd995b6 | 1393 | out_unlock: |
00e95830 | 1394 | mutex_unlock(&event_mutex); |
8b372562 TZ |
1395 | |
1396 | return err; | |
1397 | } | |
1398 | ||
1399 | int apply_subsystem_event_filter(struct event_subsystem *system, | |
1400 | char *filter_string) | |
1401 | { | |
1402 | int err; | |
8b372562 TZ |
1403 | struct filter_parse_state *ps; |
1404 | ||
00e95830 | 1405 | mutex_lock(&event_mutex); |
8b372562 | 1406 | |
8e254c1d LZ |
1407 | err = init_subsystem_preds(system); |
1408 | if (err) | |
1409 | goto out_unlock; | |
1410 | ||
8b372562 | 1411 | if (!strcmp(strstrip(filter_string), "0")) { |
fce29d15 | 1412 | filter_free_subsystem_preds(system); |
8b372562 | 1413 | remove_filter_string(system->filter); |
a66abe7f | 1414 | goto out_unlock; |
8b372562 TZ |
1415 | } |
1416 | ||
8cd995b6 | 1417 | err = -ENOMEM; |
8b372562 TZ |
1418 | ps = kzalloc(sizeof(*ps), GFP_KERNEL); |
1419 | if (!ps) | |
8cd995b6 | 1420 | goto out_unlock; |
8b372562 | 1421 | |
8b372562 TZ |
1422 | replace_filter_string(system->filter, filter_string); |
1423 | ||
1424 | parse_init(ps, filter_ops, filter_string); | |
1425 | err = filter_parse(ps); | |
1426 | if (err) { | |
1427 | append_filter_err(ps, system->filter); | |
1428 | goto out; | |
1429 | } | |
1430 | ||
fce29d15 LZ |
1431 | err = replace_system_preds(system, ps, filter_string); |
1432 | if (err) | |
8b372562 TZ |
1433 | append_filter_err(ps, system->filter); |
1434 | ||
1435 | out: | |
1436 | filter_opstack_clear(ps); | |
1437 | postfix_clear(ps); | |
1438 | kfree(ps); | |
8cd995b6 | 1439 | out_unlock: |
00e95830 | 1440 | mutex_unlock(&event_mutex); |
8b372562 TZ |
1441 | |
1442 | return err; | |
1443 | } | |
7ce7e424 | 1444 | |
07b139c8 | 1445 | #ifdef CONFIG_PERF_EVENTS |
6fb2915d LZ |
1446 | |
1447 | void ftrace_profile_free_filter(struct perf_event *event) | |
1448 | { | |
1449 | struct event_filter *filter = event->filter; | |
1450 | ||
1451 | event->filter = NULL; | |
c9c53ca0 | 1452 | __free_filter(filter); |
6fb2915d LZ |
1453 | } |
1454 | ||
1455 | int ftrace_profile_set_filter(struct perf_event *event, int event_id, | |
1456 | char *filter_str) | |
1457 | { | |
1458 | int err; | |
1459 | struct event_filter *filter; | |
1460 | struct filter_parse_state *ps; | |
1461 | struct ftrace_event_call *call = NULL; | |
1462 | ||
1463 | mutex_lock(&event_mutex); | |
1464 | ||
1465 | list_for_each_entry(call, &ftrace_events, list) { | |
32c0edae | 1466 | if (call->event.type == event_id) |
6fb2915d LZ |
1467 | break; |
1468 | } | |
a66abe7f IM |
1469 | |
1470 | err = -EINVAL; | |
d9f599e1 | 1471 | if (&call->list == &ftrace_events) |
a66abe7f | 1472 | goto out_unlock; |
6fb2915d | 1473 | |
a66abe7f | 1474 | err = -EEXIST; |
6fb2915d | 1475 | if (event->filter) |
a66abe7f | 1476 | goto out_unlock; |
6fb2915d | 1477 | |
c9c53ca0 | 1478 | filter = __alloc_filter(); |
a66abe7f IM |
1479 | if (IS_ERR(filter)) { |
1480 | err = PTR_ERR(filter); | |
1481 | goto out_unlock; | |
1482 | } | |
6fb2915d LZ |
1483 | |
1484 | err = -ENOMEM; | |
1485 | ps = kzalloc(sizeof(*ps), GFP_KERNEL); | |
1486 | if (!ps) | |
c9c53ca0 | 1487 | goto free_filter; |
6fb2915d LZ |
1488 | |
1489 | parse_init(ps, filter_ops, filter_str); | |
1490 | err = filter_parse(ps); | |
1491 | if (err) | |
1492 | goto free_ps; | |
1493 | ||
1494 | err = replace_preds(call, filter, ps, filter_str, false); | |
1495 | if (!err) | |
1496 | event->filter = filter; | |
1497 | ||
1498 | free_ps: | |
1499 | filter_opstack_clear(ps); | |
1500 | postfix_clear(ps); | |
1501 | kfree(ps); | |
1502 | ||
c9c53ca0 | 1503 | free_filter: |
6fb2915d | 1504 | if (err) |
c9c53ca0 | 1505 | __free_filter(filter); |
6fb2915d | 1506 | |
a66abe7f | 1507 | out_unlock: |
6fb2915d LZ |
1508 | mutex_unlock(&event_mutex); |
1509 | ||
1510 | return err; | |
1511 | } | |
1512 | ||
07b139c8 | 1513 | #endif /* CONFIG_PERF_EVENTS */ |
6fb2915d | 1514 |