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1 | /* | |
2 | * trace_events_trigger - trace event triggers | |
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) 2013 Tom Zanussi <tom.zanussi@linux.intel.com> | |
19 | */ | |
20 | ||
21 | #include <linux/module.h> | |
22 | #include <linux/ctype.h> | |
23 | #include <linux/mutex.h> | |
24 | #include <linux/slab.h> | |
25 | ||
26 | #include "trace.h" | |
27 | ||
28 | static LIST_HEAD(trigger_commands); | |
29 | static DEFINE_MUTEX(trigger_cmd_mutex); | |
30 | ||
31 | void trigger_data_free(struct event_trigger_data *data) | |
32 | { | |
33 | if (data->cmd_ops->set_filter) | |
34 | data->cmd_ops->set_filter(NULL, data, NULL); | |
35 | ||
36 | synchronize_sched(); /* make sure current triggers exit before free */ | |
37 | kfree(data); | |
38 | } | |
39 | ||
40 | /** | |
41 | * event_triggers_call - Call triggers associated with a trace event | |
42 | * @file: The trace_event_file associated with the event | |
43 | * @rec: The trace entry for the event, NULL for unconditional invocation | |
44 | * | |
45 | * For each trigger associated with an event, invoke the trigger | |
46 | * function registered with the associated trigger command. If rec is | |
47 | * non-NULL, it means that the trigger requires further processing and | |
48 | * shouldn't be unconditionally invoked. If rec is non-NULL and the | |
49 | * trigger has a filter associated with it, rec will checked against | |
50 | * the filter and if the record matches the trigger will be invoked. | |
51 | * If the trigger is a 'post_trigger', meaning it shouldn't be invoked | |
52 | * in any case until the current event is written, the trigger | |
53 | * function isn't invoked but the bit associated with the deferred | |
54 | * trigger is set in the return value. | |
55 | * | |
56 | * Returns an enum event_trigger_type value containing a set bit for | |
57 | * any trigger that should be deferred, ETT_NONE if nothing to defer. | |
58 | * | |
59 | * Called from tracepoint handlers (with rcu_read_lock_sched() held). | |
60 | * | |
61 | * Return: an enum event_trigger_type value containing a set bit for | |
62 | * any trigger that should be deferred, ETT_NONE if nothing to defer. | |
63 | */ | |
64 | enum event_trigger_type | |
65 | event_triggers_call(struct trace_event_file *file, void *rec) | |
66 | { | |
67 | struct event_trigger_data *data; | |
68 | enum event_trigger_type tt = ETT_NONE; | |
69 | struct event_filter *filter; | |
70 | ||
71 | if (list_empty(&file->triggers)) | |
72 | return tt; | |
73 | ||
74 | list_for_each_entry_rcu(data, &file->triggers, list) { | |
75 | if (!rec) { | |
76 | data->ops->func(data); | |
77 | continue; | |
78 | } | |
79 | filter = rcu_dereference_sched(data->filter); | |
80 | if (filter && !filter_match_preds(filter, rec)) | |
81 | continue; | |
82 | if (data->cmd_ops->post_trigger) { | |
83 | tt |= data->cmd_ops->trigger_type; | |
84 | continue; | |
85 | } | |
86 | data->ops->func(data); | |
87 | } | |
88 | return tt; | |
89 | } | |
90 | EXPORT_SYMBOL_GPL(event_triggers_call); | |
91 | ||
92 | /** | |
93 | * event_triggers_post_call - Call 'post_triggers' for a trace event | |
94 | * @file: The trace_event_file associated with the event | |
95 | * @tt: enum event_trigger_type containing a set bit for each trigger to invoke | |
96 | * | |
97 | * For each trigger associated with an event, invoke the trigger | |
98 | * function registered with the associated trigger command, if the | |
99 | * corresponding bit is set in the tt enum passed into this function. | |
100 | * See @event_triggers_call for details on how those bits are set. | |
101 | * | |
102 | * Called from tracepoint handlers (with rcu_read_lock_sched() held). | |
103 | */ | |
104 | void | |
105 | event_triggers_post_call(struct trace_event_file *file, | |
106 | enum event_trigger_type tt) | |
107 | { | |
108 | struct event_trigger_data *data; | |
109 | ||
110 | list_for_each_entry_rcu(data, &file->triggers, list) { | |
111 | if (data->cmd_ops->trigger_type & tt) | |
112 | data->ops->func(data); | |
113 | } | |
114 | } | |
115 | EXPORT_SYMBOL_GPL(event_triggers_post_call); | |
116 | ||
117 | #define SHOW_AVAILABLE_TRIGGERS (void *)(1UL) | |
118 | ||
119 | static void *trigger_next(struct seq_file *m, void *t, loff_t *pos) | |
120 | { | |
121 | struct trace_event_file *event_file = event_file_data(m->private); | |
122 | ||
123 | if (t == SHOW_AVAILABLE_TRIGGERS) | |
124 | return NULL; | |
125 | ||
126 | return seq_list_next(t, &event_file->triggers, pos); | |
127 | } | |
128 | ||
129 | static void *trigger_start(struct seq_file *m, loff_t *pos) | |
130 | { | |
131 | struct trace_event_file *event_file; | |
132 | ||
133 | /* ->stop() is called even if ->start() fails */ | |
134 | mutex_lock(&event_mutex); | |
135 | event_file = event_file_data(m->private); | |
136 | if (unlikely(!event_file)) | |
137 | return ERR_PTR(-ENODEV); | |
138 | ||
139 | if (list_empty(&event_file->triggers)) | |
140 | return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL; | |
141 | ||
142 | return seq_list_start(&event_file->triggers, *pos); | |
143 | } | |
144 | ||
145 | static void trigger_stop(struct seq_file *m, void *t) | |
146 | { | |
147 | mutex_unlock(&event_mutex); | |
148 | } | |
149 | ||
150 | static int trigger_show(struct seq_file *m, void *v) | |
151 | { | |
152 | struct event_trigger_data *data; | |
153 | struct event_command *p; | |
154 | ||
155 | if (v == SHOW_AVAILABLE_TRIGGERS) { | |
156 | seq_puts(m, "# Available triggers:\n"); | |
157 | seq_putc(m, '#'); | |
158 | mutex_lock(&trigger_cmd_mutex); | |
159 | list_for_each_entry_reverse(p, &trigger_commands, list) | |
160 | seq_printf(m, " %s", p->name); | |
161 | seq_putc(m, '\n'); | |
162 | mutex_unlock(&trigger_cmd_mutex); | |
163 | return 0; | |
164 | } | |
165 | ||
166 | data = list_entry(v, struct event_trigger_data, list); | |
167 | data->ops->print(m, data->ops, data); | |
168 | ||
169 | return 0; | |
170 | } | |
171 | ||
172 | static const struct seq_operations event_triggers_seq_ops = { | |
173 | .start = trigger_start, | |
174 | .next = trigger_next, | |
175 | .stop = trigger_stop, | |
176 | .show = trigger_show, | |
177 | }; | |
178 | ||
179 | static int event_trigger_regex_open(struct inode *inode, struct file *file) | |
180 | { | |
181 | int ret = 0; | |
182 | ||
183 | mutex_lock(&event_mutex); | |
184 | ||
185 | if (unlikely(!event_file_data(file))) { | |
186 | mutex_unlock(&event_mutex); | |
187 | return -ENODEV; | |
188 | } | |
189 | ||
190 | if (file->f_mode & FMODE_READ) { | |
191 | ret = seq_open(file, &event_triggers_seq_ops); | |
192 | if (!ret) { | |
193 | struct seq_file *m = file->private_data; | |
194 | m->private = file; | |
195 | } | |
196 | } | |
197 | ||
198 | mutex_unlock(&event_mutex); | |
199 | ||
200 | return ret; | |
201 | } | |
202 | ||
203 | static int trigger_process_regex(struct trace_event_file *file, char *buff) | |
204 | { | |
205 | char *command, *next = buff; | |
206 | struct event_command *p; | |
207 | int ret = -EINVAL; | |
208 | ||
209 | command = strsep(&next, ": \t"); | |
210 | command = (command[0] != '!') ? command : command + 1; | |
211 | ||
212 | mutex_lock(&trigger_cmd_mutex); | |
213 | list_for_each_entry(p, &trigger_commands, list) { | |
214 | if (strcmp(p->name, command) == 0) { | |
215 | ret = p->func(p, file, buff, command, next); | |
216 | goto out_unlock; | |
217 | } | |
218 | } | |
219 | out_unlock: | |
220 | mutex_unlock(&trigger_cmd_mutex); | |
221 | ||
222 | return ret; | |
223 | } | |
224 | ||
225 | static ssize_t event_trigger_regex_write(struct file *file, | |
226 | const char __user *ubuf, | |
227 | size_t cnt, loff_t *ppos) | |
228 | { | |
229 | struct trace_event_file *event_file; | |
230 | ssize_t ret; | |
231 | char *buf; | |
232 | ||
233 | if (!cnt) | |
234 | return 0; | |
235 | ||
236 | if (cnt >= PAGE_SIZE) | |
237 | return -EINVAL; | |
238 | ||
239 | buf = memdup_user_nul(ubuf, cnt); | |
240 | if (IS_ERR(buf)) | |
241 | return PTR_ERR(buf); | |
242 | ||
243 | strim(buf); | |
244 | ||
245 | mutex_lock(&event_mutex); | |
246 | event_file = event_file_data(file); | |
247 | if (unlikely(!event_file)) { | |
248 | mutex_unlock(&event_mutex); | |
249 | kfree(buf); | |
250 | return -ENODEV; | |
251 | } | |
252 | ret = trigger_process_regex(event_file, buf); | |
253 | mutex_unlock(&event_mutex); | |
254 | ||
255 | kfree(buf); | |
256 | if (ret < 0) | |
257 | goto out; | |
258 | ||
259 | *ppos += cnt; | |
260 | ret = cnt; | |
261 | out: | |
262 | return ret; | |
263 | } | |
264 | ||
265 | static int event_trigger_regex_release(struct inode *inode, struct file *file) | |
266 | { | |
267 | mutex_lock(&event_mutex); | |
268 | ||
269 | if (file->f_mode & FMODE_READ) | |
270 | seq_release(inode, file); | |
271 | ||
272 | mutex_unlock(&event_mutex); | |
273 | ||
274 | return 0; | |
275 | } | |
276 | ||
277 | static ssize_t | |
278 | event_trigger_write(struct file *filp, const char __user *ubuf, | |
279 | size_t cnt, loff_t *ppos) | |
280 | { | |
281 | return event_trigger_regex_write(filp, ubuf, cnt, ppos); | |
282 | } | |
283 | ||
284 | static int | |
285 | event_trigger_open(struct inode *inode, struct file *filp) | |
286 | { | |
287 | return event_trigger_regex_open(inode, filp); | |
288 | } | |
289 | ||
290 | static int | |
291 | event_trigger_release(struct inode *inode, struct file *file) | |
292 | { | |
293 | return event_trigger_regex_release(inode, file); | |
294 | } | |
295 | ||
296 | const struct file_operations event_trigger_fops = { | |
297 | .open = event_trigger_open, | |
298 | .read = seq_read, | |
299 | .write = event_trigger_write, | |
300 | .llseek = tracing_lseek, | |
301 | .release = event_trigger_release, | |
302 | }; | |
303 | ||
304 | /* | |
305 | * Currently we only register event commands from __init, so mark this | |
306 | * __init too. | |
307 | */ | |
308 | __init int register_event_command(struct event_command *cmd) | |
309 | { | |
310 | struct event_command *p; | |
311 | int ret = 0; | |
312 | ||
313 | mutex_lock(&trigger_cmd_mutex); | |
314 | list_for_each_entry(p, &trigger_commands, list) { | |
315 | if (strcmp(cmd->name, p->name) == 0) { | |
316 | ret = -EBUSY; | |
317 | goto out_unlock; | |
318 | } | |
319 | } | |
320 | list_add(&cmd->list, &trigger_commands); | |
321 | out_unlock: | |
322 | mutex_unlock(&trigger_cmd_mutex); | |
323 | ||
324 | return ret; | |
325 | } | |
326 | ||
327 | /* | |
328 | * Currently we only unregister event commands from __init, so mark | |
329 | * this __init too. | |
330 | */ | |
331 | static __init int unregister_event_command(struct event_command *cmd) | |
332 | { | |
333 | struct event_command *p, *n; | |
334 | int ret = -ENODEV; | |
335 | ||
336 | mutex_lock(&trigger_cmd_mutex); | |
337 | list_for_each_entry_safe(p, n, &trigger_commands, list) { | |
338 | if (strcmp(cmd->name, p->name) == 0) { | |
339 | ret = 0; | |
340 | list_del_init(&p->list); | |
341 | goto out_unlock; | |
342 | } | |
343 | } | |
344 | out_unlock: | |
345 | mutex_unlock(&trigger_cmd_mutex); | |
346 | ||
347 | return ret; | |
348 | } | |
349 | ||
350 | /** | |
351 | * event_trigger_print - Generic event_trigger_ops @print implementation | |
352 | * @name: The name of the event trigger | |
353 | * @m: The seq_file being printed to | |
354 | * @data: Trigger-specific data | |
355 | * @filter_str: filter_str to print, if present | |
356 | * | |
357 | * Common implementation for event triggers to print themselves. | |
358 | * | |
359 | * Usually wrapped by a function that simply sets the @name of the | |
360 | * trigger command and then invokes this. | |
361 | * | |
362 | * Return: 0 on success, errno otherwise | |
363 | */ | |
364 | static int | |
365 | event_trigger_print(const char *name, struct seq_file *m, | |
366 | void *data, char *filter_str) | |
367 | { | |
368 | long count = (long)data; | |
369 | ||
370 | seq_puts(m, name); | |
371 | ||
372 | if (count == -1) | |
373 | seq_puts(m, ":unlimited"); | |
374 | else | |
375 | seq_printf(m, ":count=%ld", count); | |
376 | ||
377 | if (filter_str) | |
378 | seq_printf(m, " if %s\n", filter_str); | |
379 | else | |
380 | seq_putc(m, '\n'); | |
381 | ||
382 | return 0; | |
383 | } | |
384 | ||
385 | /** | |
386 | * event_trigger_init - Generic event_trigger_ops @init implementation | |
387 | * @ops: The trigger ops associated with the trigger | |
388 | * @data: Trigger-specific data | |
389 | * | |
390 | * Common implementation of event trigger initialization. | |
391 | * | |
392 | * Usually used directly as the @init method in event trigger | |
393 | * implementations. | |
394 | * | |
395 | * Return: 0 on success, errno otherwise | |
396 | */ | |
397 | int event_trigger_init(struct event_trigger_ops *ops, | |
398 | struct event_trigger_data *data) | |
399 | { | |
400 | data->ref++; | |
401 | return 0; | |
402 | } | |
403 | ||
404 | /** | |
405 | * event_trigger_free - Generic event_trigger_ops @free implementation | |
406 | * @ops: The trigger ops associated with the trigger | |
407 | * @data: Trigger-specific data | |
408 | * | |
409 | * Common implementation of event trigger de-initialization. | |
410 | * | |
411 | * Usually used directly as the @free method in event trigger | |
412 | * implementations. | |
413 | */ | |
414 | static void | |
415 | event_trigger_free(struct event_trigger_ops *ops, | |
416 | struct event_trigger_data *data) | |
417 | { | |
418 | if (WARN_ON_ONCE(data->ref <= 0)) | |
419 | return; | |
420 | ||
421 | data->ref--; | |
422 | if (!data->ref) | |
423 | trigger_data_free(data); | |
424 | } | |
425 | ||
426 | int trace_event_trigger_enable_disable(struct trace_event_file *file, | |
427 | int trigger_enable) | |
428 | { | |
429 | int ret = 0; | |
430 | ||
431 | if (trigger_enable) { | |
432 | if (atomic_inc_return(&file->tm_ref) > 1) | |
433 | return ret; | |
434 | set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags); | |
435 | ret = trace_event_enable_disable(file, 1, 1); | |
436 | } else { | |
437 | if (atomic_dec_return(&file->tm_ref) > 0) | |
438 | return ret; | |
439 | clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags); | |
440 | ret = trace_event_enable_disable(file, 0, 1); | |
441 | } | |
442 | ||
443 | return ret; | |
444 | } | |
445 | ||
446 | /** | |
447 | * clear_event_triggers - Clear all triggers associated with a trace array | |
448 | * @tr: The trace array to clear | |
449 | * | |
450 | * For each trigger, the triggering event has its tm_ref decremented | |
451 | * via trace_event_trigger_enable_disable(), and any associated event | |
452 | * (in the case of enable/disable_event triggers) will have its sm_ref | |
453 | * decremented via free()->trace_event_enable_disable(). That | |
454 | * combination effectively reverses the soft-mode/trigger state added | |
455 | * by trigger registration. | |
456 | * | |
457 | * Must be called with event_mutex held. | |
458 | */ | |
459 | void | |
460 | clear_event_triggers(struct trace_array *tr) | |
461 | { | |
462 | struct trace_event_file *file; | |
463 | ||
464 | list_for_each_entry(file, &tr->events, list) { | |
465 | struct event_trigger_data *data; | |
466 | list_for_each_entry_rcu(data, &file->triggers, list) { | |
467 | trace_event_trigger_enable_disable(file, 0); | |
468 | if (data->ops->free) | |
469 | data->ops->free(data->ops, data); | |
470 | } | |
471 | } | |
472 | } | |
473 | ||
474 | /** | |
475 | * update_cond_flag - Set or reset the TRIGGER_COND bit | |
476 | * @file: The trace_event_file associated with the event | |
477 | * | |
478 | * If an event has triggers and any of those triggers has a filter or | |
479 | * a post_trigger, trigger invocation needs to be deferred until after | |
480 | * the current event has logged its data, and the event should have | |
481 | * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be | |
482 | * cleared. | |
483 | */ | |
484 | void update_cond_flag(struct trace_event_file *file) | |
485 | { | |
486 | struct event_trigger_data *data; | |
487 | bool set_cond = false; | |
488 | ||
489 | list_for_each_entry_rcu(data, &file->triggers, list) { | |
490 | if (data->filter || data->cmd_ops->post_trigger) { | |
491 | set_cond = true; | |
492 | break; | |
493 | } | |
494 | } | |
495 | ||
496 | if (set_cond) | |
497 | set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags); | |
498 | else | |
499 | clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags); | |
500 | } | |
501 | ||
502 | /** | |
503 | * register_trigger - Generic event_command @reg implementation | |
504 | * @glob: The raw string used to register the trigger | |
505 | * @ops: The trigger ops associated with the trigger | |
506 | * @data: Trigger-specific data to associate with the trigger | |
507 | * @file: The trace_event_file associated with the event | |
508 | * | |
509 | * Common implementation for event trigger registration. | |
510 | * | |
511 | * Usually used directly as the @reg method in event command | |
512 | * implementations. | |
513 | * | |
514 | * Return: 0 on success, errno otherwise | |
515 | */ | |
516 | static int register_trigger(char *glob, struct event_trigger_ops *ops, | |
517 | struct event_trigger_data *data, | |
518 | struct trace_event_file *file) | |
519 | { | |
520 | struct event_trigger_data *test; | |
521 | int ret = 0; | |
522 | ||
523 | list_for_each_entry_rcu(test, &file->triggers, list) { | |
524 | if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) { | |
525 | ret = -EEXIST; | |
526 | goto out; | |
527 | } | |
528 | } | |
529 | ||
530 | if (data->ops->init) { | |
531 | ret = data->ops->init(data->ops, data); | |
532 | if (ret < 0) | |
533 | goto out; | |
534 | } | |
535 | ||
536 | list_add_rcu(&data->list, &file->triggers); | |
537 | ret++; | |
538 | ||
539 | update_cond_flag(file); | |
540 | if (trace_event_trigger_enable_disable(file, 1) < 0) { | |
541 | list_del_rcu(&data->list); | |
542 | update_cond_flag(file); | |
543 | ret--; | |
544 | } | |
545 | out: | |
546 | return ret; | |
547 | } | |
548 | ||
549 | /** | |
550 | * unregister_trigger - Generic event_command @unreg implementation | |
551 | * @glob: The raw string used to register the trigger | |
552 | * @ops: The trigger ops associated with the trigger | |
553 | * @test: Trigger-specific data used to find the trigger to remove | |
554 | * @file: The trace_event_file associated with the event | |
555 | * | |
556 | * Common implementation for event trigger unregistration. | |
557 | * | |
558 | * Usually used directly as the @unreg method in event command | |
559 | * implementations. | |
560 | */ | |
561 | void unregister_trigger(char *glob, struct event_trigger_ops *ops, | |
562 | struct event_trigger_data *test, | |
563 | struct trace_event_file *file) | |
564 | { | |
565 | struct event_trigger_data *data; | |
566 | bool unregistered = false; | |
567 | ||
568 | list_for_each_entry_rcu(data, &file->triggers, list) { | |
569 | if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) { | |
570 | unregistered = true; | |
571 | list_del_rcu(&data->list); | |
572 | trace_event_trigger_enable_disable(file, 0); | |
573 | update_cond_flag(file); | |
574 | break; | |
575 | } | |
576 | } | |
577 | ||
578 | if (unregistered && data->ops->free) | |
579 | data->ops->free(data->ops, data); | |
580 | } | |
581 | ||
582 | /** | |
583 | * event_trigger_callback - Generic event_command @func implementation | |
584 | * @cmd_ops: The command ops, used for trigger registration | |
585 | * @file: The trace_event_file associated with the event | |
586 | * @glob: The raw string used to register the trigger | |
587 | * @cmd: The cmd portion of the string used to register the trigger | |
588 | * @param: The params portion of the string used to register the trigger | |
589 | * | |
590 | * Common implementation for event command parsing and trigger | |
591 | * instantiation. | |
592 | * | |
593 | * Usually used directly as the @func method in event command | |
594 | * implementations. | |
595 | * | |
596 | * Return: 0 on success, errno otherwise | |
597 | */ | |
598 | static int | |
599 | event_trigger_callback(struct event_command *cmd_ops, | |
600 | struct trace_event_file *file, | |
601 | char *glob, char *cmd, char *param) | |
602 | { | |
603 | struct event_trigger_data *trigger_data; | |
604 | struct event_trigger_ops *trigger_ops; | |
605 | char *trigger = NULL; | |
606 | char *number; | |
607 | int ret; | |
608 | ||
609 | /* separate the trigger from the filter (t:n [if filter]) */ | |
610 | if (param && isdigit(param[0])) | |
611 | trigger = strsep(¶m, " \t"); | |
612 | ||
613 | trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger); | |
614 | ||
615 | ret = -ENOMEM; | |
616 | trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL); | |
617 | if (!trigger_data) | |
618 | goto out; | |
619 | ||
620 | trigger_data->count = -1; | |
621 | trigger_data->ops = trigger_ops; | |
622 | trigger_data->cmd_ops = cmd_ops; | |
623 | INIT_LIST_HEAD(&trigger_data->list); | |
624 | ||
625 | if (glob[0] == '!') { | |
626 | cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); | |
627 | kfree(trigger_data); | |
628 | ret = 0; | |
629 | goto out; | |
630 | } | |
631 | ||
632 | if (trigger) { | |
633 | number = strsep(&trigger, ":"); | |
634 | ||
635 | ret = -EINVAL; | |
636 | if (!strlen(number)) | |
637 | goto out_free; | |
638 | ||
639 | /* | |
640 | * We use the callback data field (which is a pointer) | |
641 | * as our counter. | |
642 | */ | |
643 | ret = kstrtoul(number, 0, &trigger_data->count); | |
644 | if (ret) | |
645 | goto out_free; | |
646 | } | |
647 | ||
648 | if (!param) /* if param is non-empty, it's supposed to be a filter */ | |
649 | goto out_reg; | |
650 | ||
651 | if (!cmd_ops->set_filter) | |
652 | goto out_reg; | |
653 | ||
654 | ret = cmd_ops->set_filter(param, trigger_data, file); | |
655 | if (ret < 0) | |
656 | goto out_free; | |
657 | ||
658 | out_reg: | |
659 | ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); | |
660 | /* | |
661 | * The above returns on success the # of functions enabled, | |
662 | * but if it didn't find any functions it returns zero. | |
663 | * Consider no functions a failure too. | |
664 | */ | |
665 | if (!ret) { | |
666 | ret = -ENOENT; | |
667 | goto out_free; | |
668 | } else if (ret < 0) | |
669 | goto out_free; | |
670 | ret = 0; | |
671 | out: | |
672 | return ret; | |
673 | ||
674 | out_free: | |
675 | if (cmd_ops->set_filter) | |
676 | cmd_ops->set_filter(NULL, trigger_data, NULL); | |
677 | kfree(trigger_data); | |
678 | goto out; | |
679 | } | |
680 | ||
681 | /** | |
682 | * set_trigger_filter - Generic event_command @set_filter implementation | |
683 | * @filter_str: The filter string for the trigger, NULL to remove filter | |
684 | * @trigger_data: Trigger-specific data | |
685 | * @file: The trace_event_file associated with the event | |
686 | * | |
687 | * Common implementation for event command filter parsing and filter | |
688 | * instantiation. | |
689 | * | |
690 | * Usually used directly as the @set_filter method in event command | |
691 | * implementations. | |
692 | * | |
693 | * Also used to remove a filter (if filter_str = NULL). | |
694 | * | |
695 | * Return: 0 on success, errno otherwise | |
696 | */ | |
697 | int set_trigger_filter(char *filter_str, | |
698 | struct event_trigger_data *trigger_data, | |
699 | struct trace_event_file *file) | |
700 | { | |
701 | struct event_trigger_data *data = trigger_data; | |
702 | struct event_filter *filter = NULL, *tmp; | |
703 | int ret = -EINVAL; | |
704 | char *s; | |
705 | ||
706 | if (!filter_str) /* clear the current filter */ | |
707 | goto assign; | |
708 | ||
709 | s = strsep(&filter_str, " \t"); | |
710 | ||
711 | if (!strlen(s) || strcmp(s, "if") != 0) | |
712 | goto out; | |
713 | ||
714 | if (!filter_str) | |
715 | goto out; | |
716 | ||
717 | /* The filter is for the 'trigger' event, not the triggered event */ | |
718 | ret = create_event_filter(file->event_call, filter_str, false, &filter); | |
719 | if (ret) | |
720 | goto out; | |
721 | assign: | |
722 | tmp = rcu_access_pointer(data->filter); | |
723 | ||
724 | rcu_assign_pointer(data->filter, filter); | |
725 | ||
726 | if (tmp) { | |
727 | /* Make sure the call is done with the filter */ | |
728 | synchronize_sched(); | |
729 | free_event_filter(tmp); | |
730 | } | |
731 | ||
732 | kfree(data->filter_str); | |
733 | data->filter_str = NULL; | |
734 | ||
735 | if (filter_str) { | |
736 | data->filter_str = kstrdup(filter_str, GFP_KERNEL); | |
737 | if (!data->filter_str) { | |
738 | free_event_filter(rcu_access_pointer(data->filter)); | |
739 | data->filter = NULL; | |
740 | ret = -ENOMEM; | |
741 | } | |
742 | } | |
743 | out: | |
744 | return ret; | |
745 | } | |
746 | ||
747 | static void | |
748 | traceon_trigger(struct event_trigger_data *data) | |
749 | { | |
750 | if (tracing_is_on()) | |
751 | return; | |
752 | ||
753 | tracing_on(); | |
754 | } | |
755 | ||
756 | static void | |
757 | traceon_count_trigger(struct event_trigger_data *data) | |
758 | { | |
759 | if (tracing_is_on()) | |
760 | return; | |
761 | ||
762 | if (!data->count) | |
763 | return; | |
764 | ||
765 | if (data->count != -1) | |
766 | (data->count)--; | |
767 | ||
768 | tracing_on(); | |
769 | } | |
770 | ||
771 | static void | |
772 | traceoff_trigger(struct event_trigger_data *data) | |
773 | { | |
774 | if (!tracing_is_on()) | |
775 | return; | |
776 | ||
777 | tracing_off(); | |
778 | } | |
779 | ||
780 | static void | |
781 | traceoff_count_trigger(struct event_trigger_data *data) | |
782 | { | |
783 | if (!tracing_is_on()) | |
784 | return; | |
785 | ||
786 | if (!data->count) | |
787 | return; | |
788 | ||
789 | if (data->count != -1) | |
790 | (data->count)--; | |
791 | ||
792 | tracing_off(); | |
793 | } | |
794 | ||
795 | static int | |
796 | traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, | |
797 | struct event_trigger_data *data) | |
798 | { | |
799 | return event_trigger_print("traceon", m, (void *)data->count, | |
800 | data->filter_str); | |
801 | } | |
802 | ||
803 | static int | |
804 | traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, | |
805 | struct event_trigger_data *data) | |
806 | { | |
807 | return event_trigger_print("traceoff", m, (void *)data->count, | |
808 | data->filter_str); | |
809 | } | |
810 | ||
811 | static struct event_trigger_ops traceon_trigger_ops = { | |
812 | .func = traceon_trigger, | |
813 | .print = traceon_trigger_print, | |
814 | .init = event_trigger_init, | |
815 | .free = event_trigger_free, | |
816 | }; | |
817 | ||
818 | static struct event_trigger_ops traceon_count_trigger_ops = { | |
819 | .func = traceon_count_trigger, | |
820 | .print = traceon_trigger_print, | |
821 | .init = event_trigger_init, | |
822 | .free = event_trigger_free, | |
823 | }; | |
824 | ||
825 | static struct event_trigger_ops traceoff_trigger_ops = { | |
826 | .func = traceoff_trigger, | |
827 | .print = traceoff_trigger_print, | |
828 | .init = event_trigger_init, | |
829 | .free = event_trigger_free, | |
830 | }; | |
831 | ||
832 | static struct event_trigger_ops traceoff_count_trigger_ops = { | |
833 | .func = traceoff_count_trigger, | |
834 | .print = traceoff_trigger_print, | |
835 | .init = event_trigger_init, | |
836 | .free = event_trigger_free, | |
837 | }; | |
838 | ||
839 | static struct event_trigger_ops * | |
840 | onoff_get_trigger_ops(char *cmd, char *param) | |
841 | { | |
842 | struct event_trigger_ops *ops; | |
843 | ||
844 | /* we register both traceon and traceoff to this callback */ | |
845 | if (strcmp(cmd, "traceon") == 0) | |
846 | ops = param ? &traceon_count_trigger_ops : | |
847 | &traceon_trigger_ops; | |
848 | else | |
849 | ops = param ? &traceoff_count_trigger_ops : | |
850 | &traceoff_trigger_ops; | |
851 | ||
852 | return ops; | |
853 | } | |
854 | ||
855 | static struct event_command trigger_traceon_cmd = { | |
856 | .name = "traceon", | |
857 | .trigger_type = ETT_TRACE_ONOFF, | |
858 | .func = event_trigger_callback, | |
859 | .reg = register_trigger, | |
860 | .unreg = unregister_trigger, | |
861 | .get_trigger_ops = onoff_get_trigger_ops, | |
862 | .set_filter = set_trigger_filter, | |
863 | }; | |
864 | ||
865 | static struct event_command trigger_traceoff_cmd = { | |
866 | .name = "traceoff", | |
867 | .trigger_type = ETT_TRACE_ONOFF, | |
868 | .func = event_trigger_callback, | |
869 | .reg = register_trigger, | |
870 | .unreg = unregister_trigger, | |
871 | .get_trigger_ops = onoff_get_trigger_ops, | |
872 | .set_filter = set_trigger_filter, | |
873 | }; | |
874 | ||
875 | #ifdef CONFIG_TRACER_SNAPSHOT | |
876 | static void | |
877 | snapshot_trigger(struct event_trigger_data *data) | |
878 | { | |
879 | tracing_snapshot(); | |
880 | } | |
881 | ||
882 | static void | |
883 | snapshot_count_trigger(struct event_trigger_data *data) | |
884 | { | |
885 | if (!data->count) | |
886 | return; | |
887 | ||
888 | if (data->count != -1) | |
889 | (data->count)--; | |
890 | ||
891 | snapshot_trigger(data); | |
892 | } | |
893 | ||
894 | static int | |
895 | register_snapshot_trigger(char *glob, struct event_trigger_ops *ops, | |
896 | struct event_trigger_data *data, | |
897 | struct trace_event_file *file) | |
898 | { | |
899 | int ret = register_trigger(glob, ops, data, file); | |
900 | ||
901 | if (ret > 0 && tracing_alloc_snapshot() != 0) { | |
902 | unregister_trigger(glob, ops, data, file); | |
903 | ret = 0; | |
904 | } | |
905 | ||
906 | return ret; | |
907 | } | |
908 | ||
909 | static int | |
910 | snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, | |
911 | struct event_trigger_data *data) | |
912 | { | |
913 | return event_trigger_print("snapshot", m, (void *)data->count, | |
914 | data->filter_str); | |
915 | } | |
916 | ||
917 | static struct event_trigger_ops snapshot_trigger_ops = { | |
918 | .func = snapshot_trigger, | |
919 | .print = snapshot_trigger_print, | |
920 | .init = event_trigger_init, | |
921 | .free = event_trigger_free, | |
922 | }; | |
923 | ||
924 | static struct event_trigger_ops snapshot_count_trigger_ops = { | |
925 | .func = snapshot_count_trigger, | |
926 | .print = snapshot_trigger_print, | |
927 | .init = event_trigger_init, | |
928 | .free = event_trigger_free, | |
929 | }; | |
930 | ||
931 | static struct event_trigger_ops * | |
932 | snapshot_get_trigger_ops(char *cmd, char *param) | |
933 | { | |
934 | return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops; | |
935 | } | |
936 | ||
937 | static struct event_command trigger_snapshot_cmd = { | |
938 | .name = "snapshot", | |
939 | .trigger_type = ETT_SNAPSHOT, | |
940 | .func = event_trigger_callback, | |
941 | .reg = register_snapshot_trigger, | |
942 | .unreg = unregister_trigger, | |
943 | .get_trigger_ops = snapshot_get_trigger_ops, | |
944 | .set_filter = set_trigger_filter, | |
945 | }; | |
946 | ||
947 | static __init int register_trigger_snapshot_cmd(void) | |
948 | { | |
949 | int ret; | |
950 | ||
951 | ret = register_event_command(&trigger_snapshot_cmd); | |
952 | WARN_ON(ret < 0); | |
953 | ||
954 | return ret; | |
955 | } | |
956 | #else | |
957 | static __init int register_trigger_snapshot_cmd(void) { return 0; } | |
958 | #endif /* CONFIG_TRACER_SNAPSHOT */ | |
959 | ||
960 | #ifdef CONFIG_STACKTRACE | |
961 | /* | |
962 | * Skip 3: | |
963 | * stacktrace_trigger() | |
964 | * event_triggers_post_call() | |
965 | * trace_event_raw_event_xxx() | |
966 | */ | |
967 | #define STACK_SKIP 3 | |
968 | ||
969 | static void | |
970 | stacktrace_trigger(struct event_trigger_data *data) | |
971 | { | |
972 | trace_dump_stack(STACK_SKIP); | |
973 | } | |
974 | ||
975 | static void | |
976 | stacktrace_count_trigger(struct event_trigger_data *data) | |
977 | { | |
978 | if (!data->count) | |
979 | return; | |
980 | ||
981 | if (data->count != -1) | |
982 | (data->count)--; | |
983 | ||
984 | stacktrace_trigger(data); | |
985 | } | |
986 | ||
987 | static int | |
988 | stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, | |
989 | struct event_trigger_data *data) | |
990 | { | |
991 | return event_trigger_print("stacktrace", m, (void *)data->count, | |
992 | data->filter_str); | |
993 | } | |
994 | ||
995 | static struct event_trigger_ops stacktrace_trigger_ops = { | |
996 | .func = stacktrace_trigger, | |
997 | .print = stacktrace_trigger_print, | |
998 | .init = event_trigger_init, | |
999 | .free = event_trigger_free, | |
1000 | }; | |
1001 | ||
1002 | static struct event_trigger_ops stacktrace_count_trigger_ops = { | |
1003 | .func = stacktrace_count_trigger, | |
1004 | .print = stacktrace_trigger_print, | |
1005 | .init = event_trigger_init, | |
1006 | .free = event_trigger_free, | |
1007 | }; | |
1008 | ||
1009 | static struct event_trigger_ops * | |
1010 | stacktrace_get_trigger_ops(char *cmd, char *param) | |
1011 | { | |
1012 | return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops; | |
1013 | } | |
1014 | ||
1015 | static struct event_command trigger_stacktrace_cmd = { | |
1016 | .name = "stacktrace", | |
1017 | .trigger_type = ETT_STACKTRACE, | |
1018 | .post_trigger = true, | |
1019 | .func = event_trigger_callback, | |
1020 | .reg = register_trigger, | |
1021 | .unreg = unregister_trigger, | |
1022 | .get_trigger_ops = stacktrace_get_trigger_ops, | |
1023 | .set_filter = set_trigger_filter, | |
1024 | }; | |
1025 | ||
1026 | static __init int register_trigger_stacktrace_cmd(void) | |
1027 | { | |
1028 | int ret; | |
1029 | ||
1030 | ret = register_event_command(&trigger_stacktrace_cmd); | |
1031 | WARN_ON(ret < 0); | |
1032 | ||
1033 | return ret; | |
1034 | } | |
1035 | #else | |
1036 | static __init int register_trigger_stacktrace_cmd(void) { return 0; } | |
1037 | #endif /* CONFIG_STACKTRACE */ | |
1038 | ||
1039 | static __init void unregister_trigger_traceon_traceoff_cmds(void) | |
1040 | { | |
1041 | unregister_event_command(&trigger_traceon_cmd); | |
1042 | unregister_event_command(&trigger_traceoff_cmd); | |
1043 | } | |
1044 | ||
1045 | /* Avoid typos */ | |
1046 | #define ENABLE_EVENT_STR "enable_event" | |
1047 | #define DISABLE_EVENT_STR "disable_event" | |
1048 | ||
1049 | struct enable_trigger_data { | |
1050 | struct trace_event_file *file; | |
1051 | bool enable; | |
1052 | }; | |
1053 | ||
1054 | static void | |
1055 | event_enable_trigger(struct event_trigger_data *data) | |
1056 | { | |
1057 | struct enable_trigger_data *enable_data = data->private_data; | |
1058 | ||
1059 | if (enable_data->enable) | |
1060 | clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags); | |
1061 | else | |
1062 | set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags); | |
1063 | } | |
1064 | ||
1065 | static void | |
1066 | event_enable_count_trigger(struct event_trigger_data *data) | |
1067 | { | |
1068 | struct enable_trigger_data *enable_data = data->private_data; | |
1069 | ||
1070 | if (!data->count) | |
1071 | return; | |
1072 | ||
1073 | /* Skip if the event is in a state we want to switch to */ | |
1074 | if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED)) | |
1075 | return; | |
1076 | ||
1077 | if (data->count != -1) | |
1078 | (data->count)--; | |
1079 | ||
1080 | event_enable_trigger(data); | |
1081 | } | |
1082 | ||
1083 | static int | |
1084 | event_enable_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, | |
1085 | struct event_trigger_data *data) | |
1086 | { | |
1087 | struct enable_trigger_data *enable_data = data->private_data; | |
1088 | ||
1089 | seq_printf(m, "%s:%s:%s", | |
1090 | enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR, | |
1091 | enable_data->file->event_call->class->system, | |
1092 | trace_event_name(enable_data->file->event_call)); | |
1093 | ||
1094 | if (data->count == -1) | |
1095 | seq_puts(m, ":unlimited"); | |
1096 | else | |
1097 | seq_printf(m, ":count=%ld", data->count); | |
1098 | ||
1099 | if (data->filter_str) | |
1100 | seq_printf(m, " if %s\n", data->filter_str); | |
1101 | else | |
1102 | seq_putc(m, '\n'); | |
1103 | ||
1104 | return 0; | |
1105 | } | |
1106 | ||
1107 | static void | |
1108 | event_enable_trigger_free(struct event_trigger_ops *ops, | |
1109 | struct event_trigger_data *data) | |
1110 | { | |
1111 | struct enable_trigger_data *enable_data = data->private_data; | |
1112 | ||
1113 | if (WARN_ON_ONCE(data->ref <= 0)) | |
1114 | return; | |
1115 | ||
1116 | data->ref--; | |
1117 | if (!data->ref) { | |
1118 | /* Remove the SOFT_MODE flag */ | |
1119 | trace_event_enable_disable(enable_data->file, 0, 1); | |
1120 | module_put(enable_data->file->event_call->mod); | |
1121 | trigger_data_free(data); | |
1122 | kfree(enable_data); | |
1123 | } | |
1124 | } | |
1125 | ||
1126 | static struct event_trigger_ops event_enable_trigger_ops = { | |
1127 | .func = event_enable_trigger, | |
1128 | .print = event_enable_trigger_print, | |
1129 | .init = event_trigger_init, | |
1130 | .free = event_enable_trigger_free, | |
1131 | }; | |
1132 | ||
1133 | static struct event_trigger_ops event_enable_count_trigger_ops = { | |
1134 | .func = event_enable_count_trigger, | |
1135 | .print = event_enable_trigger_print, | |
1136 | .init = event_trigger_init, | |
1137 | .free = event_enable_trigger_free, | |
1138 | }; | |
1139 | ||
1140 | static struct event_trigger_ops event_disable_trigger_ops = { | |
1141 | .func = event_enable_trigger, | |
1142 | .print = event_enable_trigger_print, | |
1143 | .init = event_trigger_init, | |
1144 | .free = event_enable_trigger_free, | |
1145 | }; | |
1146 | ||
1147 | static struct event_trigger_ops event_disable_count_trigger_ops = { | |
1148 | .func = event_enable_count_trigger, | |
1149 | .print = event_enable_trigger_print, | |
1150 | .init = event_trigger_init, | |
1151 | .free = event_enable_trigger_free, | |
1152 | }; | |
1153 | ||
1154 | static int | |
1155 | event_enable_trigger_func(struct event_command *cmd_ops, | |
1156 | struct trace_event_file *file, | |
1157 | char *glob, char *cmd, char *param) | |
1158 | { | |
1159 | struct trace_event_file *event_enable_file; | |
1160 | struct enable_trigger_data *enable_data; | |
1161 | struct event_trigger_data *trigger_data; | |
1162 | struct event_trigger_ops *trigger_ops; | |
1163 | struct trace_array *tr = file->tr; | |
1164 | const char *system; | |
1165 | const char *event; | |
1166 | char *trigger; | |
1167 | char *number; | |
1168 | bool enable; | |
1169 | int ret; | |
1170 | ||
1171 | if (!param) | |
1172 | return -EINVAL; | |
1173 | ||
1174 | /* separate the trigger from the filter (s:e:n [if filter]) */ | |
1175 | trigger = strsep(¶m, " \t"); | |
1176 | if (!trigger) | |
1177 | return -EINVAL; | |
1178 | ||
1179 | system = strsep(&trigger, ":"); | |
1180 | if (!trigger) | |
1181 | return -EINVAL; | |
1182 | ||
1183 | event = strsep(&trigger, ":"); | |
1184 | ||
1185 | ret = -EINVAL; | |
1186 | event_enable_file = find_event_file(tr, system, event); | |
1187 | if (!event_enable_file) | |
1188 | goto out; | |
1189 | ||
1190 | enable = strcmp(cmd, ENABLE_EVENT_STR) == 0; | |
1191 | ||
1192 | trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger); | |
1193 | ||
1194 | ret = -ENOMEM; | |
1195 | trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL); | |
1196 | if (!trigger_data) | |
1197 | goto out; | |
1198 | ||
1199 | enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL); | |
1200 | if (!enable_data) { | |
1201 | kfree(trigger_data); | |
1202 | goto out; | |
1203 | } | |
1204 | ||
1205 | trigger_data->count = -1; | |
1206 | trigger_data->ops = trigger_ops; | |
1207 | trigger_data->cmd_ops = cmd_ops; | |
1208 | INIT_LIST_HEAD(&trigger_data->list); | |
1209 | RCU_INIT_POINTER(trigger_data->filter, NULL); | |
1210 | ||
1211 | enable_data->enable = enable; | |
1212 | enable_data->file = event_enable_file; | |
1213 | trigger_data->private_data = enable_data; | |
1214 | ||
1215 | if (glob[0] == '!') { | |
1216 | cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); | |
1217 | kfree(trigger_data); | |
1218 | kfree(enable_data); | |
1219 | ret = 0; | |
1220 | goto out; | |
1221 | } | |
1222 | ||
1223 | if (trigger) { | |
1224 | number = strsep(&trigger, ":"); | |
1225 | ||
1226 | ret = -EINVAL; | |
1227 | if (!strlen(number)) | |
1228 | goto out_free; | |
1229 | ||
1230 | /* | |
1231 | * We use the callback data field (which is a pointer) | |
1232 | * as our counter. | |
1233 | */ | |
1234 | ret = kstrtoul(number, 0, &trigger_data->count); | |
1235 | if (ret) | |
1236 | goto out_free; | |
1237 | } | |
1238 | ||
1239 | if (!param) /* if param is non-empty, it's supposed to be a filter */ | |
1240 | goto out_reg; | |
1241 | ||
1242 | if (!cmd_ops->set_filter) | |
1243 | goto out_reg; | |
1244 | ||
1245 | ret = cmd_ops->set_filter(param, trigger_data, file); | |
1246 | if (ret < 0) | |
1247 | goto out_free; | |
1248 | ||
1249 | out_reg: | |
1250 | /* Don't let event modules unload while probe registered */ | |
1251 | ret = try_module_get(event_enable_file->event_call->mod); | |
1252 | if (!ret) { | |
1253 | ret = -EBUSY; | |
1254 | goto out_free; | |
1255 | } | |
1256 | ||
1257 | ret = trace_event_enable_disable(event_enable_file, 1, 1); | |
1258 | if (ret < 0) | |
1259 | goto out_put; | |
1260 | ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); | |
1261 | /* | |
1262 | * The above returns on success the # of functions enabled, | |
1263 | * but if it didn't find any functions it returns zero. | |
1264 | * Consider no functions a failure too. | |
1265 | */ | |
1266 | if (!ret) { | |
1267 | ret = -ENOENT; | |
1268 | goto out_disable; | |
1269 | } else if (ret < 0) | |
1270 | goto out_disable; | |
1271 | /* Just return zero, not the number of enabled functions */ | |
1272 | ret = 0; | |
1273 | out: | |
1274 | return ret; | |
1275 | ||
1276 | out_disable: | |
1277 | trace_event_enable_disable(event_enable_file, 0, 1); | |
1278 | out_put: | |
1279 | module_put(event_enable_file->event_call->mod); | |
1280 | out_free: | |
1281 | if (cmd_ops->set_filter) | |
1282 | cmd_ops->set_filter(NULL, trigger_data, NULL); | |
1283 | kfree(trigger_data); | |
1284 | kfree(enable_data); | |
1285 | goto out; | |
1286 | } | |
1287 | ||
1288 | static int event_enable_register_trigger(char *glob, | |
1289 | struct event_trigger_ops *ops, | |
1290 | struct event_trigger_data *data, | |
1291 | struct trace_event_file *file) | |
1292 | { | |
1293 | struct enable_trigger_data *enable_data = data->private_data; | |
1294 | struct enable_trigger_data *test_enable_data; | |
1295 | struct event_trigger_data *test; | |
1296 | int ret = 0; | |
1297 | ||
1298 | list_for_each_entry_rcu(test, &file->triggers, list) { | |
1299 | test_enable_data = test->private_data; | |
1300 | if (test_enable_data && | |
1301 | (test_enable_data->file == enable_data->file)) { | |
1302 | ret = -EEXIST; | |
1303 | goto out; | |
1304 | } | |
1305 | } | |
1306 | ||
1307 | if (data->ops->init) { | |
1308 | ret = data->ops->init(data->ops, data); | |
1309 | if (ret < 0) | |
1310 | goto out; | |
1311 | } | |
1312 | ||
1313 | list_add_rcu(&data->list, &file->triggers); | |
1314 | ret++; | |
1315 | ||
1316 | update_cond_flag(file); | |
1317 | if (trace_event_trigger_enable_disable(file, 1) < 0) { | |
1318 | list_del_rcu(&data->list); | |
1319 | update_cond_flag(file); | |
1320 | ret--; | |
1321 | } | |
1322 | out: | |
1323 | return ret; | |
1324 | } | |
1325 | ||
1326 | static void event_enable_unregister_trigger(char *glob, | |
1327 | struct event_trigger_ops *ops, | |
1328 | struct event_trigger_data *test, | |
1329 | struct trace_event_file *file) | |
1330 | { | |
1331 | struct enable_trigger_data *test_enable_data = test->private_data; | |
1332 | struct enable_trigger_data *enable_data; | |
1333 | struct event_trigger_data *data; | |
1334 | bool unregistered = false; | |
1335 | ||
1336 | list_for_each_entry_rcu(data, &file->triggers, list) { | |
1337 | enable_data = data->private_data; | |
1338 | if (enable_data && | |
1339 | (enable_data->file == test_enable_data->file)) { | |
1340 | unregistered = true; | |
1341 | list_del_rcu(&data->list); | |
1342 | trace_event_trigger_enable_disable(file, 0); | |
1343 | update_cond_flag(file); | |
1344 | break; | |
1345 | } | |
1346 | } | |
1347 | ||
1348 | if (unregistered && data->ops->free) | |
1349 | data->ops->free(data->ops, data); | |
1350 | } | |
1351 | ||
1352 | static struct event_trigger_ops * | |
1353 | event_enable_get_trigger_ops(char *cmd, char *param) | |
1354 | { | |
1355 | struct event_trigger_ops *ops; | |
1356 | bool enable; | |
1357 | ||
1358 | enable = strcmp(cmd, ENABLE_EVENT_STR) == 0; | |
1359 | ||
1360 | if (enable) | |
1361 | ops = param ? &event_enable_count_trigger_ops : | |
1362 | &event_enable_trigger_ops; | |
1363 | else | |
1364 | ops = param ? &event_disable_count_trigger_ops : | |
1365 | &event_disable_trigger_ops; | |
1366 | ||
1367 | return ops; | |
1368 | } | |
1369 | ||
1370 | static struct event_command trigger_enable_cmd = { | |
1371 | .name = ENABLE_EVENT_STR, | |
1372 | .trigger_type = ETT_EVENT_ENABLE, | |
1373 | .func = event_enable_trigger_func, | |
1374 | .reg = event_enable_register_trigger, | |
1375 | .unreg = event_enable_unregister_trigger, | |
1376 | .get_trigger_ops = event_enable_get_trigger_ops, | |
1377 | .set_filter = set_trigger_filter, | |
1378 | }; | |
1379 | ||
1380 | static struct event_command trigger_disable_cmd = { | |
1381 | .name = DISABLE_EVENT_STR, | |
1382 | .trigger_type = ETT_EVENT_ENABLE, | |
1383 | .func = event_enable_trigger_func, | |
1384 | .reg = event_enable_register_trigger, | |
1385 | .unreg = event_enable_unregister_trigger, | |
1386 | .get_trigger_ops = event_enable_get_trigger_ops, | |
1387 | .set_filter = set_trigger_filter, | |
1388 | }; | |
1389 | ||
1390 | static __init void unregister_trigger_enable_disable_cmds(void) | |
1391 | { | |
1392 | unregister_event_command(&trigger_enable_cmd); | |
1393 | unregister_event_command(&trigger_disable_cmd); | |
1394 | } | |
1395 | ||
1396 | static __init int register_trigger_enable_disable_cmds(void) | |
1397 | { | |
1398 | int ret; | |
1399 | ||
1400 | ret = register_event_command(&trigger_enable_cmd); | |
1401 | if (WARN_ON(ret < 0)) | |
1402 | return ret; | |
1403 | ret = register_event_command(&trigger_disable_cmd); | |
1404 | if (WARN_ON(ret < 0)) | |
1405 | unregister_trigger_enable_disable_cmds(); | |
1406 | ||
1407 | return ret; | |
1408 | } | |
1409 | ||
1410 | static __init int register_trigger_traceon_traceoff_cmds(void) | |
1411 | { | |
1412 | int ret; | |
1413 | ||
1414 | ret = register_event_command(&trigger_traceon_cmd); | |
1415 | if (WARN_ON(ret < 0)) | |
1416 | return ret; | |
1417 | ret = register_event_command(&trigger_traceoff_cmd); | |
1418 | if (WARN_ON(ret < 0)) | |
1419 | unregister_trigger_traceon_traceoff_cmds(); | |
1420 | ||
1421 | return ret; | |
1422 | } | |
1423 | ||
1424 | __init int register_trigger_cmds(void) | |
1425 | { | |
1426 | register_trigger_traceon_traceoff_cmds(); | |
1427 | register_trigger_snapshot_cmd(); | |
1428 | register_trigger_stacktrace_cmd(); | |
1429 | register_trigger_enable_disable_cmds(); | |
1430 | ||
1431 | return 0; | |
1432 | } |