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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#include <linux/rculist.h>
26
27#include "trace.h"
28
29static LIST_HEAD(trigger_commands);
30static DEFINE_MUTEX(trigger_cmd_mutex);
31
32void trigger_data_free(struct event_trigger_data *data)
33{
34 if (data->cmd_ops->set_filter)
35 data->cmd_ops->set_filter(NULL, data, NULL);
36
37 synchronize_sched(); /* make sure current triggers exit before free */
38 kfree(data);
39}
40
41/**
42 * event_triggers_call - Call triggers associated with a trace event
43 * @file: The trace_event_file associated with the event
44 * @rec: The trace entry for the event, NULL for unconditional invocation
45 *
46 * For each trigger associated with an event, invoke the trigger
47 * function registered with the associated trigger command. If rec is
48 * non-NULL, it means that the trigger requires further processing and
49 * shouldn't be unconditionally invoked. If rec is non-NULL and the
50 * trigger has a filter associated with it, rec will checked against
51 * the filter and if the record matches the trigger will be invoked.
52 * If the trigger is a 'post_trigger', meaning it shouldn't be invoked
53 * in any case until the current event is written, the trigger
54 * function isn't invoked but the bit associated with the deferred
55 * trigger is set in the return value.
56 *
57 * Returns an enum event_trigger_type value containing a set bit for
58 * any trigger that should be deferred, ETT_NONE if nothing to defer.
59 *
60 * Called from tracepoint handlers (with rcu_read_lock_sched() held).
61 *
62 * Return: an enum event_trigger_type value containing a set bit for
63 * any trigger that should be deferred, ETT_NONE if nothing to defer.
64 */
65enum event_trigger_type
66event_triggers_call(struct trace_event_file *file, void *rec,
67 struct ring_buffer_event *event)
68{
69 struct event_trigger_data *data;
70 enum event_trigger_type tt = ETT_NONE;
71 struct event_filter *filter;
72
73 if (list_empty(&file->triggers))
74 return tt;
75
76 list_for_each_entry_rcu(data, &file->triggers, list) {
77 if (data->paused)
78 continue;
79 if (!rec) {
80 data->ops->func(data, rec, event);
81 continue;
82 }
83 filter = rcu_dereference_sched(data->filter);
84 if (filter && !filter_match_preds(filter, rec))
85 continue;
86 if (event_command_post_trigger(data->cmd_ops)) {
87 tt |= data->cmd_ops->trigger_type;
88 continue;
89 }
90 data->ops->func(data, rec, event);
91 }
92 return tt;
93}
94EXPORT_SYMBOL_GPL(event_triggers_call);
95
96/**
97 * event_triggers_post_call - Call 'post_triggers' for a trace event
98 * @file: The trace_event_file associated with the event
99 * @tt: enum event_trigger_type containing a set bit for each trigger to invoke
100 * @rec: The trace entry for the event
101 *
102 * For each trigger associated with an event, invoke the trigger
103 * function registered with the associated trigger command, if the
104 * corresponding bit is set in the tt enum passed into this function.
105 * See @event_triggers_call for details on how those bits are set.
106 *
107 * Called from tracepoint handlers (with rcu_read_lock_sched() held).
108 */
109void
110event_triggers_post_call(struct trace_event_file *file,
111 enum event_trigger_type tt,
112 void *rec, struct ring_buffer_event *event)
113{
114 struct event_trigger_data *data;
115
116 list_for_each_entry_rcu(data, &file->triggers, list) {
117 if (data->paused)
118 continue;
119 if (data->cmd_ops->trigger_type & tt)
120 data->ops->func(data, rec, event);
121 }
122}
123EXPORT_SYMBOL_GPL(event_triggers_post_call);
124
125#define SHOW_AVAILABLE_TRIGGERS (void *)(1UL)
126
127static void *trigger_next(struct seq_file *m, void *t, loff_t *pos)
128{
129 struct trace_event_file *event_file = event_file_data(m->private);
130
131 if (t == SHOW_AVAILABLE_TRIGGERS)
132 return NULL;
133
134 return seq_list_next(t, &event_file->triggers, pos);
135}
136
137static void *trigger_start(struct seq_file *m, loff_t *pos)
138{
139 struct trace_event_file *event_file;
140
141 /* ->stop() is called even if ->start() fails */
142 mutex_lock(&event_mutex);
143 event_file = event_file_data(m->private);
144 if (unlikely(!event_file))
145 return ERR_PTR(-ENODEV);
146
147 if (list_empty(&event_file->triggers))
148 return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL;
149
150 return seq_list_start(&event_file->triggers, *pos);
151}
152
153static void trigger_stop(struct seq_file *m, void *t)
154{
155 mutex_unlock(&event_mutex);
156}
157
158static int trigger_show(struct seq_file *m, void *v)
159{
160 struct event_trigger_data *data;
161 struct event_command *p;
162
163 if (v == SHOW_AVAILABLE_TRIGGERS) {
164 seq_puts(m, "# Available triggers:\n");
165 seq_putc(m, '#');
166 mutex_lock(&trigger_cmd_mutex);
167 list_for_each_entry_reverse(p, &trigger_commands, list)
168 seq_printf(m, " %s", p->name);
169 seq_putc(m, '\n');
170 mutex_unlock(&trigger_cmd_mutex);
171 return 0;
172 }
173
174 data = list_entry(v, struct event_trigger_data, list);
175 data->ops->print(m, data->ops, data);
176
177 return 0;
178}
179
180static const struct seq_operations event_triggers_seq_ops = {
181 .start = trigger_start,
182 .next = trigger_next,
183 .stop = trigger_stop,
184 .show = trigger_show,
185};
186
187static int event_trigger_regex_open(struct inode *inode, struct file *file)
188{
189 int ret = 0;
190
191 mutex_lock(&event_mutex);
192
193 if (unlikely(!event_file_data(file))) {
194 mutex_unlock(&event_mutex);
195 return -ENODEV;
196 }
197
198 if ((file->f_mode & FMODE_WRITE) &&
199 (file->f_flags & O_TRUNC)) {
200 struct trace_event_file *event_file;
201 struct event_command *p;
202
203 event_file = event_file_data(file);
204
205 list_for_each_entry(p, &trigger_commands, list) {
206 if (p->unreg_all)
207 p->unreg_all(event_file);
208 }
209 }
210
211 if (file->f_mode & FMODE_READ) {
212 ret = seq_open(file, &event_triggers_seq_ops);
213 if (!ret) {
214 struct seq_file *m = file->private_data;
215 m->private = file;
216 }
217 }
218
219 mutex_unlock(&event_mutex);
220
221 return ret;
222}
223
224static int trigger_process_regex(struct trace_event_file *file, char *buff)
225{
226 char *command, *next = buff;
227 struct event_command *p;
228 int ret = -EINVAL;
229
230 command = strsep(&next, ": \t");
231 command = (command[0] != '!') ? command : command + 1;
232
233 mutex_lock(&trigger_cmd_mutex);
234 list_for_each_entry(p, &trigger_commands, list) {
235 if (strcmp(p->name, command) == 0) {
236 ret = p->func(p, file, buff, command, next);
237 goto out_unlock;
238 }
239 }
240 out_unlock:
241 mutex_unlock(&trigger_cmd_mutex);
242
243 return ret;
244}
245
246static ssize_t event_trigger_regex_write(struct file *file,
247 const char __user *ubuf,
248 size_t cnt, loff_t *ppos)
249{
250 struct trace_event_file *event_file;
251 ssize_t ret;
252 char *buf;
253
254 if (!cnt)
255 return 0;
256
257 if (cnt >= PAGE_SIZE)
258 return -EINVAL;
259
260 buf = memdup_user_nul(ubuf, cnt);
261 if (IS_ERR(buf))
262 return PTR_ERR(buf);
263
264 strim(buf);
265
266 mutex_lock(&event_mutex);
267 event_file = event_file_data(file);
268 if (unlikely(!event_file)) {
269 mutex_unlock(&event_mutex);
270 kfree(buf);
271 return -ENODEV;
272 }
273 ret = trigger_process_regex(event_file, buf);
274 mutex_unlock(&event_mutex);
275
276 kfree(buf);
277 if (ret < 0)
278 goto out;
279
280 *ppos += cnt;
281 ret = cnt;
282 out:
283 return ret;
284}
285
286static int event_trigger_regex_release(struct inode *inode, struct file *file)
287{
288 mutex_lock(&event_mutex);
289
290 if (file->f_mode & FMODE_READ)
291 seq_release(inode, file);
292
293 mutex_unlock(&event_mutex);
294
295 return 0;
296}
297
298static ssize_t
299event_trigger_write(struct file *filp, const char __user *ubuf,
300 size_t cnt, loff_t *ppos)
301{
302 return event_trigger_regex_write(filp, ubuf, cnt, ppos);
303}
304
305static int
306event_trigger_open(struct inode *inode, struct file *filp)
307{
308 return event_trigger_regex_open(inode, filp);
309}
310
311static int
312event_trigger_release(struct inode *inode, struct file *file)
313{
314 return event_trigger_regex_release(inode, file);
315}
316
317const struct file_operations event_trigger_fops = {
318 .open = event_trigger_open,
319 .read = seq_read,
320 .write = event_trigger_write,
321 .llseek = tracing_lseek,
322 .release = event_trigger_release,
323};
324
325/*
326 * Currently we only register event commands from __init, so mark this
327 * __init too.
328 */
329__init int register_event_command(struct event_command *cmd)
330{
331 struct event_command *p;
332 int ret = 0;
333
334 mutex_lock(&trigger_cmd_mutex);
335 list_for_each_entry(p, &trigger_commands, list) {
336 if (strcmp(cmd->name, p->name) == 0) {
337 ret = -EBUSY;
338 goto out_unlock;
339 }
340 }
341 list_add(&cmd->list, &trigger_commands);
342 out_unlock:
343 mutex_unlock(&trigger_cmd_mutex);
344
345 return ret;
346}
347
348/*
349 * Currently we only unregister event commands from __init, so mark
350 * this __init too.
351 */
352__init int unregister_event_command(struct event_command *cmd)
353{
354 struct event_command *p, *n;
355 int ret = -ENODEV;
356
357 mutex_lock(&trigger_cmd_mutex);
358 list_for_each_entry_safe(p, n, &trigger_commands, list) {
359 if (strcmp(cmd->name, p->name) == 0) {
360 ret = 0;
361 list_del_init(&p->list);
362 goto out_unlock;
363 }
364 }
365 out_unlock:
366 mutex_unlock(&trigger_cmd_mutex);
367
368 return ret;
369}
370
371/**
372 * event_trigger_print - Generic event_trigger_ops @print implementation
373 * @name: The name of the event trigger
374 * @m: The seq_file being printed to
375 * @data: Trigger-specific data
376 * @filter_str: filter_str to print, if present
377 *
378 * Common implementation for event triggers to print themselves.
379 *
380 * Usually wrapped by a function that simply sets the @name of the
381 * trigger command and then invokes this.
382 *
383 * Return: 0 on success, errno otherwise
384 */
385static int
386event_trigger_print(const char *name, struct seq_file *m,
387 void *data, char *filter_str)
388{
389 long count = (long)data;
390
391 seq_puts(m, name);
392
393 if (count == -1)
394 seq_puts(m, ":unlimited");
395 else
396 seq_printf(m, ":count=%ld", count);
397
398 if (filter_str)
399 seq_printf(m, " if %s\n", filter_str);
400 else
401 seq_putc(m, '\n');
402
403 return 0;
404}
405
406/**
407 * event_trigger_init - Generic event_trigger_ops @init implementation
408 * @ops: The trigger ops associated with the trigger
409 * @data: Trigger-specific data
410 *
411 * Common implementation of event trigger initialization.
412 *
413 * Usually used directly as the @init method in event trigger
414 * implementations.
415 *
416 * Return: 0 on success, errno otherwise
417 */
418int event_trigger_init(struct event_trigger_ops *ops,
419 struct event_trigger_data *data)
420{
421 data->ref++;
422 return 0;
423}
424
425/**
426 * event_trigger_free - Generic event_trigger_ops @free implementation
427 * @ops: The trigger ops associated with the trigger
428 * @data: Trigger-specific data
429 *
430 * Common implementation of event trigger de-initialization.
431 *
432 * Usually used directly as the @free method in event trigger
433 * implementations.
434 */
435static void
436event_trigger_free(struct event_trigger_ops *ops,
437 struct event_trigger_data *data)
438{
439 if (WARN_ON_ONCE(data->ref <= 0))
440 return;
441
442 data->ref--;
443 if (!data->ref)
444 trigger_data_free(data);
445}
446
447int trace_event_trigger_enable_disable(struct trace_event_file *file,
448 int trigger_enable)
449{
450 int ret = 0;
451
452 if (trigger_enable) {
453 if (atomic_inc_return(&file->tm_ref) > 1)
454 return ret;
455 set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
456 ret = trace_event_enable_disable(file, 1, 1);
457 } else {
458 if (atomic_dec_return(&file->tm_ref) > 0)
459 return ret;
460 clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
461 ret = trace_event_enable_disable(file, 0, 1);
462 }
463
464 return ret;
465}
466
467/**
468 * clear_event_triggers - Clear all triggers associated with a trace array
469 * @tr: The trace array to clear
470 *
471 * For each trigger, the triggering event has its tm_ref decremented
472 * via trace_event_trigger_enable_disable(), and any associated event
473 * (in the case of enable/disable_event triggers) will have its sm_ref
474 * decremented via free()->trace_event_enable_disable(). That
475 * combination effectively reverses the soft-mode/trigger state added
476 * by trigger registration.
477 *
478 * Must be called with event_mutex held.
479 */
480void
481clear_event_triggers(struct trace_array *tr)
482{
483 struct trace_event_file *file;
484
485 list_for_each_entry(file, &tr->events, list) {
486 struct event_trigger_data *data, *n;
487 list_for_each_entry_safe(data, n, &file->triggers, list) {
488 trace_event_trigger_enable_disable(file, 0);
489 list_del_rcu(&data->list);
490 if (data->ops->free)
491 data->ops->free(data->ops, data);
492 }
493 }
494}
495
496/**
497 * update_cond_flag - Set or reset the TRIGGER_COND bit
498 * @file: The trace_event_file associated with the event
499 *
500 * If an event has triggers and any of those triggers has a filter or
501 * a post_trigger, trigger invocation needs to be deferred until after
502 * the current event has logged its data, and the event should have
503 * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be
504 * cleared.
505 */
506void update_cond_flag(struct trace_event_file *file)
507{
508 struct event_trigger_data *data;
509 bool set_cond = false;
510
511 list_for_each_entry_rcu(data, &file->triggers, list) {
512 if (data->filter || event_command_post_trigger(data->cmd_ops) ||
513 event_command_needs_rec(data->cmd_ops)) {
514 set_cond = true;
515 break;
516 }
517 }
518
519 if (set_cond)
520 set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
521 else
522 clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
523}
524
525/**
526 * register_trigger - Generic event_command @reg implementation
527 * @glob: The raw string used to register the trigger
528 * @ops: The trigger ops associated with the trigger
529 * @data: Trigger-specific data to associate with the trigger
530 * @file: The trace_event_file associated with the event
531 *
532 * Common implementation for event trigger registration.
533 *
534 * Usually used directly as the @reg method in event command
535 * implementations.
536 *
537 * Return: 0 on success, errno otherwise
538 */
539static int register_trigger(char *glob, struct event_trigger_ops *ops,
540 struct event_trigger_data *data,
541 struct trace_event_file *file)
542{
543 struct event_trigger_data *test;
544 int ret = 0;
545
546 list_for_each_entry_rcu(test, &file->triggers, list) {
547 if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) {
548 ret = -EEXIST;
549 goto out;
550 }
551 }
552
553 if (data->ops->init) {
554 ret = data->ops->init(data->ops, data);
555 if (ret < 0)
556 goto out;
557 }
558
559 list_add_rcu(&data->list, &file->triggers);
560 ret++;
561
562 update_cond_flag(file);
563 if (trace_event_trigger_enable_disable(file, 1) < 0) {
564 list_del_rcu(&data->list);
565 update_cond_flag(file);
566 ret--;
567 }
568out:
569 return ret;
570}
571
572/**
573 * unregister_trigger - Generic event_command @unreg implementation
574 * @glob: The raw string used to register the trigger
575 * @ops: The trigger ops associated with the trigger
576 * @test: Trigger-specific data used to find the trigger to remove
577 * @file: The trace_event_file associated with the event
578 *
579 * Common implementation for event trigger unregistration.
580 *
581 * Usually used directly as the @unreg method in event command
582 * implementations.
583 */
584void unregister_trigger(char *glob, struct event_trigger_ops *ops,
585 struct event_trigger_data *test,
586 struct trace_event_file *file)
587{
588 struct event_trigger_data *data;
589 bool unregistered = false;
590
591 list_for_each_entry_rcu(data, &file->triggers, list) {
592 if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
593 unregistered = true;
594 list_del_rcu(&data->list);
595 trace_event_trigger_enable_disable(file, 0);
596 update_cond_flag(file);
597 break;
598 }
599 }
600
601 if (unregistered && data->ops->free)
602 data->ops->free(data->ops, data);
603}
604
605/**
606 * event_trigger_callback - Generic event_command @func implementation
607 * @cmd_ops: The command ops, used for trigger registration
608 * @file: The trace_event_file associated with the event
609 * @glob: The raw string used to register the trigger
610 * @cmd: The cmd portion of the string used to register the trigger
611 * @param: The params portion of the string used to register the trigger
612 *
613 * Common implementation for event command parsing and trigger
614 * instantiation.
615 *
616 * Usually used directly as the @func method in event command
617 * implementations.
618 *
619 * Return: 0 on success, errno otherwise
620 */
621static int
622event_trigger_callback(struct event_command *cmd_ops,
623 struct trace_event_file *file,
624 char *glob, char *cmd, char *param)
625{
626 struct event_trigger_data *trigger_data;
627 struct event_trigger_ops *trigger_ops;
628 char *trigger = NULL;
629 char *number;
630 int ret;
631
632 /* separate the trigger from the filter (t:n [if filter]) */
633 if (param && isdigit(param[0]))
634 trigger = strsep(¶m, " \t");
635
636 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
637
638 ret = -ENOMEM;
639 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
640 if (!trigger_data)
641 goto out;
642
643 trigger_data->count = -1;
644 trigger_data->ops = trigger_ops;
645 trigger_data->cmd_ops = cmd_ops;
646 trigger_data->private_data = file;
647 INIT_LIST_HEAD(&trigger_data->list);
648 INIT_LIST_HEAD(&trigger_data->named_list);
649
650 if (glob[0] == '!') {
651 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
652 kfree(trigger_data);
653 ret = 0;
654 goto out;
655 }
656
657 if (trigger) {
658 number = strsep(&trigger, ":");
659
660 ret = -EINVAL;
661 if (!strlen(number))
662 goto out_free;
663
664 /*
665 * We use the callback data field (which is a pointer)
666 * as our counter.
667 */
668 ret = kstrtoul(number, 0, &trigger_data->count);
669 if (ret)
670 goto out_free;
671 }
672
673 if (!param) /* if param is non-empty, it's supposed to be a filter */
674 goto out_reg;
675
676 if (!cmd_ops->set_filter)
677 goto out_reg;
678
679 ret = cmd_ops->set_filter(param, trigger_data, file);
680 if (ret < 0)
681 goto out_free;
682
683 out_reg:
684 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
685 /*
686 * The above returns on success the # of functions enabled,
687 * but if it didn't find any functions it returns zero.
688 * Consider no functions a failure too.
689 */
690 if (!ret) {
691 ret = -ENOENT;
692 goto out_free;
693 } else if (ret < 0)
694 goto out_free;
695 ret = 0;
696 out:
697 return ret;
698
699 out_free:
700 if (cmd_ops->set_filter)
701 cmd_ops->set_filter(NULL, trigger_data, NULL);
702 kfree(trigger_data);
703 goto out;
704}
705
706/**
707 * set_trigger_filter - Generic event_command @set_filter implementation
708 * @filter_str: The filter string for the trigger, NULL to remove filter
709 * @trigger_data: Trigger-specific data
710 * @file: The trace_event_file associated with the event
711 *
712 * Common implementation for event command filter parsing and filter
713 * instantiation.
714 *
715 * Usually used directly as the @set_filter method in event command
716 * implementations.
717 *
718 * Also used to remove a filter (if filter_str = NULL).
719 *
720 * Return: 0 on success, errno otherwise
721 */
722int set_trigger_filter(char *filter_str,
723 struct event_trigger_data *trigger_data,
724 struct trace_event_file *file)
725{
726 struct event_trigger_data *data = trigger_data;
727 struct event_filter *filter = NULL, *tmp;
728 int ret = -EINVAL;
729 char *s;
730
731 if (!filter_str) /* clear the current filter */
732 goto assign;
733
734 s = strsep(&filter_str, " \t");
735
736 if (!strlen(s) || strcmp(s, "if") != 0)
737 goto out;
738
739 if (!filter_str)
740 goto out;
741
742 /* The filter is for the 'trigger' event, not the triggered event */
743 ret = create_event_filter(file->event_call, filter_str, false, &filter);
744 if (ret)
745 goto out;
746 assign:
747 tmp = rcu_access_pointer(data->filter);
748
749 rcu_assign_pointer(data->filter, filter);
750
751 if (tmp) {
752 /* Make sure the call is done with the filter */
753 synchronize_sched();
754 free_event_filter(tmp);
755 }
756
757 kfree(data->filter_str);
758 data->filter_str = NULL;
759
760 if (filter_str) {
761 data->filter_str = kstrdup(filter_str, GFP_KERNEL);
762 if (!data->filter_str) {
763 free_event_filter(rcu_access_pointer(data->filter));
764 data->filter = NULL;
765 ret = -ENOMEM;
766 }
767 }
768 out:
769 return ret;
770}
771
772static LIST_HEAD(named_triggers);
773
774/**
775 * find_named_trigger - Find the common named trigger associated with @name
776 * @name: The name of the set of named triggers to find the common data for
777 *
778 * Named triggers are sets of triggers that share a common set of
779 * trigger data. The first named trigger registered with a given name
780 * owns the common trigger data that the others subsequently
781 * registered with the same name will reference. This function
782 * returns the common trigger data associated with that first
783 * registered instance.
784 *
785 * Return: the common trigger data for the given named trigger on
786 * success, NULL otherwise.
787 */
788struct event_trigger_data *find_named_trigger(const char *name)
789{
790 struct event_trigger_data *data;
791
792 if (!name)
793 return NULL;
794
795 list_for_each_entry(data, &named_triggers, named_list) {
796 if (data->named_data)
797 continue;
798 if (strcmp(data->name, name) == 0)
799 return data;
800 }
801
802 return NULL;
803}
804
805/**
806 * is_named_trigger - determine if a given trigger is a named trigger
807 * @test: The trigger data to test
808 *
809 * Return: true if 'test' is a named trigger, false otherwise.
810 */
811bool is_named_trigger(struct event_trigger_data *test)
812{
813 struct event_trigger_data *data;
814
815 list_for_each_entry(data, &named_triggers, named_list) {
816 if (test == data)
817 return true;
818 }
819
820 return false;
821}
822
823/**
824 * save_named_trigger - save the trigger in the named trigger list
825 * @name: The name of the named trigger set
826 * @data: The trigger data to save
827 *
828 * Return: 0 if successful, negative error otherwise.
829 */
830int save_named_trigger(const char *name, struct event_trigger_data *data)
831{
832 data->name = kstrdup(name, GFP_KERNEL);
833 if (!data->name)
834 return -ENOMEM;
835
836 list_add(&data->named_list, &named_triggers);
837
838 return 0;
839}
840
841/**
842 * del_named_trigger - delete a trigger from the named trigger list
843 * @data: The trigger data to delete
844 */
845void del_named_trigger(struct event_trigger_data *data)
846{
847 kfree(data->name);
848 data->name = NULL;
849
850 list_del(&data->named_list);
851}
852
853static void __pause_named_trigger(struct event_trigger_data *data, bool pause)
854{
855 struct event_trigger_data *test;
856
857 list_for_each_entry(test, &named_triggers, named_list) {
858 if (strcmp(test->name, data->name) == 0) {
859 if (pause) {
860 test->paused_tmp = test->paused;
861 test->paused = true;
862 } else {
863 test->paused = test->paused_tmp;
864 }
865 }
866 }
867}
868
869/**
870 * pause_named_trigger - Pause all named triggers with the same name
871 * @data: The trigger data of a named trigger to pause
872 *
873 * Pauses a named trigger along with all other triggers having the
874 * same name. Because named triggers share a common set of data,
875 * pausing only one is meaningless, so pausing one named trigger needs
876 * to pause all triggers with the same name.
877 */
878void pause_named_trigger(struct event_trigger_data *data)
879{
880 __pause_named_trigger(data, true);
881}
882
883/**
884 * unpause_named_trigger - Un-pause all named triggers with the same name
885 * @data: The trigger data of a named trigger to unpause
886 *
887 * Un-pauses a named trigger along with all other triggers having the
888 * same name. Because named triggers share a common set of data,
889 * unpausing only one is meaningless, so unpausing one named trigger
890 * needs to unpause all triggers with the same name.
891 */
892void unpause_named_trigger(struct event_trigger_data *data)
893{
894 __pause_named_trigger(data, false);
895}
896
897/**
898 * set_named_trigger_data - Associate common named trigger data
899 * @data: The trigger data of a named trigger to unpause
900 *
901 * Named triggers are sets of triggers that share a common set of
902 * trigger data. The first named trigger registered with a given name
903 * owns the common trigger data that the others subsequently
904 * registered with the same name will reference. This function
905 * associates the common trigger data from the first trigger with the
906 * given trigger.
907 */
908void set_named_trigger_data(struct event_trigger_data *data,
909 struct event_trigger_data *named_data)
910{
911 data->named_data = named_data;
912}
913
914struct event_trigger_data *
915get_named_trigger_data(struct event_trigger_data *data)
916{
917 return data->named_data;
918}
919
920static void
921traceon_trigger(struct event_trigger_data *data, void *rec,
922 struct ring_buffer_event *event)
923{
924 if (tracing_is_on())
925 return;
926
927 tracing_on();
928}
929
930static void
931traceon_count_trigger(struct event_trigger_data *data, void *rec,
932 struct ring_buffer_event *event)
933{
934 if (tracing_is_on())
935 return;
936
937 if (!data->count)
938 return;
939
940 if (data->count != -1)
941 (data->count)--;
942
943 tracing_on();
944}
945
946static void
947traceoff_trigger(struct event_trigger_data *data, void *rec,
948 struct ring_buffer_event *event)
949{
950 if (!tracing_is_on())
951 return;
952
953 tracing_off();
954}
955
956static void
957traceoff_count_trigger(struct event_trigger_data *data, void *rec,
958 struct ring_buffer_event *event)
959{
960 if (!tracing_is_on())
961 return;
962
963 if (!data->count)
964 return;
965
966 if (data->count != -1)
967 (data->count)--;
968
969 tracing_off();
970}
971
972static int
973traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
974 struct event_trigger_data *data)
975{
976 return event_trigger_print("traceon", m, (void *)data->count,
977 data->filter_str);
978}
979
980static int
981traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
982 struct event_trigger_data *data)
983{
984 return event_trigger_print("traceoff", m, (void *)data->count,
985 data->filter_str);
986}
987
988static struct event_trigger_ops traceon_trigger_ops = {
989 .func = traceon_trigger,
990 .print = traceon_trigger_print,
991 .init = event_trigger_init,
992 .free = event_trigger_free,
993};
994
995static struct event_trigger_ops traceon_count_trigger_ops = {
996 .func = traceon_count_trigger,
997 .print = traceon_trigger_print,
998 .init = event_trigger_init,
999 .free = event_trigger_free,
1000};
1001
1002static struct event_trigger_ops traceoff_trigger_ops = {
1003 .func = traceoff_trigger,
1004 .print = traceoff_trigger_print,
1005 .init = event_trigger_init,
1006 .free = event_trigger_free,
1007};
1008
1009static struct event_trigger_ops traceoff_count_trigger_ops = {
1010 .func = traceoff_count_trigger,
1011 .print = traceoff_trigger_print,
1012 .init = event_trigger_init,
1013 .free = event_trigger_free,
1014};
1015
1016static struct event_trigger_ops *
1017onoff_get_trigger_ops(char *cmd, char *param)
1018{
1019 struct event_trigger_ops *ops;
1020
1021 /* we register both traceon and traceoff to this callback */
1022 if (strcmp(cmd, "traceon") == 0)
1023 ops = param ? &traceon_count_trigger_ops :
1024 &traceon_trigger_ops;
1025 else
1026 ops = param ? &traceoff_count_trigger_ops :
1027 &traceoff_trigger_ops;
1028
1029 return ops;
1030}
1031
1032static struct event_command trigger_traceon_cmd = {
1033 .name = "traceon",
1034 .trigger_type = ETT_TRACE_ONOFF,
1035 .func = event_trigger_callback,
1036 .reg = register_trigger,
1037 .unreg = unregister_trigger,
1038 .get_trigger_ops = onoff_get_trigger_ops,
1039 .set_filter = set_trigger_filter,
1040};
1041
1042static struct event_command trigger_traceoff_cmd = {
1043 .name = "traceoff",
1044 .trigger_type = ETT_TRACE_ONOFF,
1045 .flags = EVENT_CMD_FL_POST_TRIGGER,
1046 .func = event_trigger_callback,
1047 .reg = register_trigger,
1048 .unreg = unregister_trigger,
1049 .get_trigger_ops = onoff_get_trigger_ops,
1050 .set_filter = set_trigger_filter,
1051};
1052
1053#ifdef CONFIG_TRACER_SNAPSHOT
1054static void
1055snapshot_trigger(struct event_trigger_data *data, void *rec,
1056 struct ring_buffer_event *event)
1057{
1058 struct trace_event_file *file = data->private_data;
1059
1060 if (file)
1061 tracing_snapshot_instance(file->tr);
1062 else
1063 tracing_snapshot();
1064}
1065
1066static void
1067snapshot_count_trigger(struct event_trigger_data *data, void *rec,
1068 struct ring_buffer_event *event)
1069{
1070 if (!data->count)
1071 return;
1072
1073 if (data->count != -1)
1074 (data->count)--;
1075
1076 snapshot_trigger(data, rec, event);
1077}
1078
1079static int
1080register_snapshot_trigger(char *glob, struct event_trigger_ops *ops,
1081 struct event_trigger_data *data,
1082 struct trace_event_file *file)
1083{
1084 int ret = register_trigger(glob, ops, data, file);
1085
1086 if (ret > 0 && tracing_alloc_snapshot_instance(file->tr) != 0) {
1087 unregister_trigger(glob, ops, data, file);
1088 ret = 0;
1089 }
1090
1091 return ret;
1092}
1093
1094static int
1095snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1096 struct event_trigger_data *data)
1097{
1098 return event_trigger_print("snapshot", m, (void *)data->count,
1099 data->filter_str);
1100}
1101
1102static struct event_trigger_ops snapshot_trigger_ops = {
1103 .func = snapshot_trigger,
1104 .print = snapshot_trigger_print,
1105 .init = event_trigger_init,
1106 .free = event_trigger_free,
1107};
1108
1109static struct event_trigger_ops snapshot_count_trigger_ops = {
1110 .func = snapshot_count_trigger,
1111 .print = snapshot_trigger_print,
1112 .init = event_trigger_init,
1113 .free = event_trigger_free,
1114};
1115
1116static struct event_trigger_ops *
1117snapshot_get_trigger_ops(char *cmd, char *param)
1118{
1119 return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
1120}
1121
1122static struct event_command trigger_snapshot_cmd = {
1123 .name = "snapshot",
1124 .trigger_type = ETT_SNAPSHOT,
1125 .func = event_trigger_callback,
1126 .reg = register_snapshot_trigger,
1127 .unreg = unregister_trigger,
1128 .get_trigger_ops = snapshot_get_trigger_ops,
1129 .set_filter = set_trigger_filter,
1130};
1131
1132static __init int register_trigger_snapshot_cmd(void)
1133{
1134 int ret;
1135
1136 ret = register_event_command(&trigger_snapshot_cmd);
1137 WARN_ON(ret < 0);
1138
1139 return ret;
1140}
1141#else
1142static __init int register_trigger_snapshot_cmd(void) { return 0; }
1143#endif /* CONFIG_TRACER_SNAPSHOT */
1144
1145#ifdef CONFIG_STACKTRACE
1146#ifdef CONFIG_UNWINDER_ORC
1147/* Skip 2:
1148 * event_triggers_post_call()
1149 * trace_event_raw_event_xxx()
1150 */
1151# define STACK_SKIP 2
1152#else
1153/*
1154 * Skip 4:
1155 * stacktrace_trigger()
1156 * event_triggers_post_call()
1157 * trace_event_buffer_commit()
1158 * trace_event_raw_event_xxx()
1159 */
1160#define STACK_SKIP 4
1161#endif
1162
1163static void
1164stacktrace_trigger(struct event_trigger_data *data, void *rec,
1165 struct ring_buffer_event *event)
1166{
1167 trace_dump_stack(STACK_SKIP);
1168}
1169
1170static void
1171stacktrace_count_trigger(struct event_trigger_data *data, void *rec,
1172 struct ring_buffer_event *event)
1173{
1174 if (!data->count)
1175 return;
1176
1177 if (data->count != -1)
1178 (data->count)--;
1179
1180 stacktrace_trigger(data, rec, event);
1181}
1182
1183static int
1184stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1185 struct event_trigger_data *data)
1186{
1187 return event_trigger_print("stacktrace", m, (void *)data->count,
1188 data->filter_str);
1189}
1190
1191static struct event_trigger_ops stacktrace_trigger_ops = {
1192 .func = stacktrace_trigger,
1193 .print = stacktrace_trigger_print,
1194 .init = event_trigger_init,
1195 .free = event_trigger_free,
1196};
1197
1198static struct event_trigger_ops stacktrace_count_trigger_ops = {
1199 .func = stacktrace_count_trigger,
1200 .print = stacktrace_trigger_print,
1201 .init = event_trigger_init,
1202 .free = event_trigger_free,
1203};
1204
1205static struct event_trigger_ops *
1206stacktrace_get_trigger_ops(char *cmd, char *param)
1207{
1208 return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
1209}
1210
1211static struct event_command trigger_stacktrace_cmd = {
1212 .name = "stacktrace",
1213 .trigger_type = ETT_STACKTRACE,
1214 .flags = EVENT_CMD_FL_POST_TRIGGER,
1215 .func = event_trigger_callback,
1216 .reg = register_trigger,
1217 .unreg = unregister_trigger,
1218 .get_trigger_ops = stacktrace_get_trigger_ops,
1219 .set_filter = set_trigger_filter,
1220};
1221
1222static __init int register_trigger_stacktrace_cmd(void)
1223{
1224 int ret;
1225
1226 ret = register_event_command(&trigger_stacktrace_cmd);
1227 WARN_ON(ret < 0);
1228
1229 return ret;
1230}
1231#else
1232static __init int register_trigger_stacktrace_cmd(void) { return 0; }
1233#endif /* CONFIG_STACKTRACE */
1234
1235static __init void unregister_trigger_traceon_traceoff_cmds(void)
1236{
1237 unregister_event_command(&trigger_traceon_cmd);
1238 unregister_event_command(&trigger_traceoff_cmd);
1239}
1240
1241static void
1242event_enable_trigger(struct event_trigger_data *data, void *rec,
1243 struct ring_buffer_event *event)
1244{
1245 struct enable_trigger_data *enable_data = data->private_data;
1246
1247 if (enable_data->enable)
1248 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1249 else
1250 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1251}
1252
1253static void
1254event_enable_count_trigger(struct event_trigger_data *data, void *rec,
1255 struct ring_buffer_event *event)
1256{
1257 struct enable_trigger_data *enable_data = data->private_data;
1258
1259 if (!data->count)
1260 return;
1261
1262 /* Skip if the event is in a state we want to switch to */
1263 if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
1264 return;
1265
1266 if (data->count != -1)
1267 (data->count)--;
1268
1269 event_enable_trigger(data, rec, event);
1270}
1271
1272int event_enable_trigger_print(struct seq_file *m,
1273 struct event_trigger_ops *ops,
1274 struct event_trigger_data *data)
1275{
1276 struct enable_trigger_data *enable_data = data->private_data;
1277
1278 seq_printf(m, "%s:%s:%s",
1279 enable_data->hist ?
1280 (enable_data->enable ? ENABLE_HIST_STR : DISABLE_HIST_STR) :
1281 (enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR),
1282 enable_data->file->event_call->class->system,
1283 trace_event_name(enable_data->file->event_call));
1284
1285 if (data->count == -1)
1286 seq_puts(m, ":unlimited");
1287 else
1288 seq_printf(m, ":count=%ld", data->count);
1289
1290 if (data->filter_str)
1291 seq_printf(m, " if %s\n", data->filter_str);
1292 else
1293 seq_putc(m, '\n');
1294
1295 return 0;
1296}
1297
1298void event_enable_trigger_free(struct event_trigger_ops *ops,
1299 struct event_trigger_data *data)
1300{
1301 struct enable_trigger_data *enable_data = data->private_data;
1302
1303 if (WARN_ON_ONCE(data->ref <= 0))
1304 return;
1305
1306 data->ref--;
1307 if (!data->ref) {
1308 /* Remove the SOFT_MODE flag */
1309 trace_event_enable_disable(enable_data->file, 0, 1);
1310 module_put(enable_data->file->event_call->mod);
1311 trigger_data_free(data);
1312 kfree(enable_data);
1313 }
1314}
1315
1316static struct event_trigger_ops event_enable_trigger_ops = {
1317 .func = event_enable_trigger,
1318 .print = event_enable_trigger_print,
1319 .init = event_trigger_init,
1320 .free = event_enable_trigger_free,
1321};
1322
1323static struct event_trigger_ops event_enable_count_trigger_ops = {
1324 .func = event_enable_count_trigger,
1325 .print = event_enable_trigger_print,
1326 .init = event_trigger_init,
1327 .free = event_enable_trigger_free,
1328};
1329
1330static struct event_trigger_ops event_disable_trigger_ops = {
1331 .func = event_enable_trigger,
1332 .print = event_enable_trigger_print,
1333 .init = event_trigger_init,
1334 .free = event_enable_trigger_free,
1335};
1336
1337static struct event_trigger_ops event_disable_count_trigger_ops = {
1338 .func = event_enable_count_trigger,
1339 .print = event_enable_trigger_print,
1340 .init = event_trigger_init,
1341 .free = event_enable_trigger_free,
1342};
1343
1344int event_enable_trigger_func(struct event_command *cmd_ops,
1345 struct trace_event_file *file,
1346 char *glob, char *cmd, char *param)
1347{
1348 struct trace_event_file *event_enable_file;
1349 struct enable_trigger_data *enable_data;
1350 struct event_trigger_data *trigger_data;
1351 struct event_trigger_ops *trigger_ops;
1352 struct trace_array *tr = file->tr;
1353 const char *system;
1354 const char *event;
1355 bool hist = false;
1356 char *trigger;
1357 char *number;
1358 bool enable;
1359 int ret;
1360
1361 if (!param)
1362 return -EINVAL;
1363
1364 /* separate the trigger from the filter (s:e:n [if filter]) */
1365 trigger = strsep(¶m, " \t");
1366 if (!trigger)
1367 return -EINVAL;
1368
1369 system = strsep(&trigger, ":");
1370 if (!trigger)
1371 return -EINVAL;
1372
1373 event = strsep(&trigger, ":");
1374
1375 ret = -EINVAL;
1376 event_enable_file = find_event_file(tr, system, event);
1377 if (!event_enable_file)
1378 goto out;
1379
1380#ifdef CONFIG_HIST_TRIGGERS
1381 hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) ||
1382 (strcmp(cmd, DISABLE_HIST_STR) == 0));
1383
1384 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1385 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1386#else
1387 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1388#endif
1389 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
1390
1391 ret = -ENOMEM;
1392 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
1393 if (!trigger_data)
1394 goto out;
1395
1396 enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
1397 if (!enable_data) {
1398 kfree(trigger_data);
1399 goto out;
1400 }
1401
1402 trigger_data->count = -1;
1403 trigger_data->ops = trigger_ops;
1404 trigger_data->cmd_ops = cmd_ops;
1405 INIT_LIST_HEAD(&trigger_data->list);
1406 RCU_INIT_POINTER(trigger_data->filter, NULL);
1407
1408 enable_data->hist = hist;
1409 enable_data->enable = enable;
1410 enable_data->file = event_enable_file;
1411 trigger_data->private_data = enable_data;
1412
1413 if (glob[0] == '!') {
1414 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
1415 kfree(trigger_data);
1416 kfree(enable_data);
1417 ret = 0;
1418 goto out;
1419 }
1420
1421 if (trigger) {
1422 number = strsep(&trigger, ":");
1423
1424 ret = -EINVAL;
1425 if (!strlen(number))
1426 goto out_free;
1427
1428 /*
1429 * We use the callback data field (which is a pointer)
1430 * as our counter.
1431 */
1432 ret = kstrtoul(number, 0, &trigger_data->count);
1433 if (ret)
1434 goto out_free;
1435 }
1436
1437 if (!param) /* if param is non-empty, it's supposed to be a filter */
1438 goto out_reg;
1439
1440 if (!cmd_ops->set_filter)
1441 goto out_reg;
1442
1443 ret = cmd_ops->set_filter(param, trigger_data, file);
1444 if (ret < 0)
1445 goto out_free;
1446
1447 out_reg:
1448 /* Don't let event modules unload while probe registered */
1449 ret = try_module_get(event_enable_file->event_call->mod);
1450 if (!ret) {
1451 ret = -EBUSY;
1452 goto out_free;
1453 }
1454
1455 ret = trace_event_enable_disable(event_enable_file, 1, 1);
1456 if (ret < 0)
1457 goto out_put;
1458 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1459 /*
1460 * The above returns on success the # of functions enabled,
1461 * but if it didn't find any functions it returns zero.
1462 * Consider no functions a failure too.
1463 */
1464 if (!ret) {
1465 ret = -ENOENT;
1466 goto out_disable;
1467 } else if (ret < 0)
1468 goto out_disable;
1469 /* Just return zero, not the number of enabled functions */
1470 ret = 0;
1471 out:
1472 return ret;
1473
1474 out_disable:
1475 trace_event_enable_disable(event_enable_file, 0, 1);
1476 out_put:
1477 module_put(event_enable_file->event_call->mod);
1478 out_free:
1479 if (cmd_ops->set_filter)
1480 cmd_ops->set_filter(NULL, trigger_data, NULL);
1481 kfree(trigger_data);
1482 kfree(enable_data);
1483 goto out;
1484}
1485
1486int event_enable_register_trigger(char *glob,
1487 struct event_trigger_ops *ops,
1488 struct event_trigger_data *data,
1489 struct trace_event_file *file)
1490{
1491 struct enable_trigger_data *enable_data = data->private_data;
1492 struct enable_trigger_data *test_enable_data;
1493 struct event_trigger_data *test;
1494 int ret = 0;
1495
1496 list_for_each_entry_rcu(test, &file->triggers, list) {
1497 test_enable_data = test->private_data;
1498 if (test_enable_data &&
1499 (test->cmd_ops->trigger_type ==
1500 data->cmd_ops->trigger_type) &&
1501 (test_enable_data->file == enable_data->file)) {
1502 ret = -EEXIST;
1503 goto out;
1504 }
1505 }
1506
1507 if (data->ops->init) {
1508 ret = data->ops->init(data->ops, data);
1509 if (ret < 0)
1510 goto out;
1511 }
1512
1513 list_add_rcu(&data->list, &file->triggers);
1514 ret++;
1515
1516 update_cond_flag(file);
1517 if (trace_event_trigger_enable_disable(file, 1) < 0) {
1518 list_del_rcu(&data->list);
1519 update_cond_flag(file);
1520 ret--;
1521 }
1522out:
1523 return ret;
1524}
1525
1526void event_enable_unregister_trigger(char *glob,
1527 struct event_trigger_ops *ops,
1528 struct event_trigger_data *test,
1529 struct trace_event_file *file)
1530{
1531 struct enable_trigger_data *test_enable_data = test->private_data;
1532 struct enable_trigger_data *enable_data;
1533 struct event_trigger_data *data;
1534 bool unregistered = false;
1535
1536 list_for_each_entry_rcu(data, &file->triggers, list) {
1537 enable_data = data->private_data;
1538 if (enable_data &&
1539 (data->cmd_ops->trigger_type ==
1540 test->cmd_ops->trigger_type) &&
1541 (enable_data->file == test_enable_data->file)) {
1542 unregistered = true;
1543 list_del_rcu(&data->list);
1544 trace_event_trigger_enable_disable(file, 0);
1545 update_cond_flag(file);
1546 break;
1547 }
1548 }
1549
1550 if (unregistered && data->ops->free)
1551 data->ops->free(data->ops, data);
1552}
1553
1554static struct event_trigger_ops *
1555event_enable_get_trigger_ops(char *cmd, char *param)
1556{
1557 struct event_trigger_ops *ops;
1558 bool enable;
1559
1560#ifdef CONFIG_HIST_TRIGGERS
1561 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1562 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1563#else
1564 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1565#endif
1566 if (enable)
1567 ops = param ? &event_enable_count_trigger_ops :
1568 &event_enable_trigger_ops;
1569 else
1570 ops = param ? &event_disable_count_trigger_ops :
1571 &event_disable_trigger_ops;
1572
1573 return ops;
1574}
1575
1576static struct event_command trigger_enable_cmd = {
1577 .name = ENABLE_EVENT_STR,
1578 .trigger_type = ETT_EVENT_ENABLE,
1579 .func = event_enable_trigger_func,
1580 .reg = event_enable_register_trigger,
1581 .unreg = event_enable_unregister_trigger,
1582 .get_trigger_ops = event_enable_get_trigger_ops,
1583 .set_filter = set_trigger_filter,
1584};
1585
1586static struct event_command trigger_disable_cmd = {
1587 .name = DISABLE_EVENT_STR,
1588 .trigger_type = ETT_EVENT_ENABLE,
1589 .func = event_enable_trigger_func,
1590 .reg = event_enable_register_trigger,
1591 .unreg = event_enable_unregister_trigger,
1592 .get_trigger_ops = event_enable_get_trigger_ops,
1593 .set_filter = set_trigger_filter,
1594};
1595
1596static __init void unregister_trigger_enable_disable_cmds(void)
1597{
1598 unregister_event_command(&trigger_enable_cmd);
1599 unregister_event_command(&trigger_disable_cmd);
1600}
1601
1602static __init int register_trigger_enable_disable_cmds(void)
1603{
1604 int ret;
1605
1606 ret = register_event_command(&trigger_enable_cmd);
1607 if (WARN_ON(ret < 0))
1608 return ret;
1609 ret = register_event_command(&trigger_disable_cmd);
1610 if (WARN_ON(ret < 0))
1611 unregister_trigger_enable_disable_cmds();
1612
1613 return ret;
1614}
1615
1616static __init int register_trigger_traceon_traceoff_cmds(void)
1617{
1618 int ret;
1619
1620 ret = register_event_command(&trigger_traceon_cmd);
1621 if (WARN_ON(ret < 0))
1622 return ret;
1623 ret = register_event_command(&trigger_traceoff_cmd);
1624 if (WARN_ON(ret < 0))
1625 unregister_trigger_traceon_traceoff_cmds();
1626
1627 return ret;
1628}
1629
1630__init int register_trigger_cmds(void)
1631{
1632 register_trigger_traceon_traceoff_cmds();
1633 register_trigger_snapshot_cmd();
1634 register_trigger_stacktrace_cmd();
1635 register_trigger_enable_disable_cmds();
1636 register_trigger_hist_enable_disable_cmds();
1637 register_trigger_hist_cmd();
1638
1639 return 0;
1640}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * trace_events_trigger - trace event triggers
4 *
5 * Copyright (C) 2013 Tom Zanussi <tom.zanussi@linux.intel.com>
6 */
7
8#include <linux/security.h>
9#include <linux/module.h>
10#include <linux/ctype.h>
11#include <linux/mutex.h>
12#include <linux/slab.h>
13#include <linux/rculist.h>
14
15#include "trace.h"
16
17static LIST_HEAD(trigger_commands);
18static DEFINE_MUTEX(trigger_cmd_mutex);
19
20void trigger_data_free(struct event_trigger_data *data)
21{
22 if (data->cmd_ops->set_filter)
23 data->cmd_ops->set_filter(NULL, data, NULL);
24
25 /* make sure current triggers exit before free */
26 tracepoint_synchronize_unregister();
27
28 kfree(data);
29}
30
31/**
32 * event_triggers_call - Call triggers associated with a trace event
33 * @file: The trace_event_file associated with the event
34 * @rec: The trace entry for the event, NULL for unconditional invocation
35 *
36 * For each trigger associated with an event, invoke the trigger
37 * function registered with the associated trigger command. If rec is
38 * non-NULL, it means that the trigger requires further processing and
39 * shouldn't be unconditionally invoked. If rec is non-NULL and the
40 * trigger has a filter associated with it, rec will checked against
41 * the filter and if the record matches the trigger will be invoked.
42 * If the trigger is a 'post_trigger', meaning it shouldn't be invoked
43 * in any case until the current event is written, the trigger
44 * function isn't invoked but the bit associated with the deferred
45 * trigger is set in the return value.
46 *
47 * Returns an enum event_trigger_type value containing a set bit for
48 * any trigger that should be deferred, ETT_NONE if nothing to defer.
49 *
50 * Called from tracepoint handlers (with rcu_read_lock_sched() held).
51 *
52 * Return: an enum event_trigger_type value containing a set bit for
53 * any trigger that should be deferred, ETT_NONE if nothing to defer.
54 */
55enum event_trigger_type
56event_triggers_call(struct trace_event_file *file,
57 struct trace_buffer *buffer, void *rec,
58 struct ring_buffer_event *event)
59{
60 struct event_trigger_data *data;
61 enum event_trigger_type tt = ETT_NONE;
62 struct event_filter *filter;
63
64 if (list_empty(&file->triggers))
65 return tt;
66
67 list_for_each_entry_rcu(data, &file->triggers, list) {
68 if (data->paused)
69 continue;
70 if (!rec) {
71 data->ops->func(data, buffer, rec, event);
72 continue;
73 }
74 filter = rcu_dereference_sched(data->filter);
75 if (filter && !filter_match_preds(filter, rec))
76 continue;
77 if (event_command_post_trigger(data->cmd_ops)) {
78 tt |= data->cmd_ops->trigger_type;
79 continue;
80 }
81 data->ops->func(data, buffer, rec, event);
82 }
83 return tt;
84}
85EXPORT_SYMBOL_GPL(event_triggers_call);
86
87/**
88 * event_triggers_post_call - Call 'post_triggers' for a trace event
89 * @file: The trace_event_file associated with the event
90 * @tt: enum event_trigger_type containing a set bit for each trigger to invoke
91 *
92 * For each trigger associated with an event, invoke the trigger
93 * function registered with the associated trigger command, if the
94 * corresponding bit is set in the tt enum passed into this function.
95 * See @event_triggers_call for details on how those bits are set.
96 *
97 * Called from tracepoint handlers (with rcu_read_lock_sched() held).
98 */
99void
100event_triggers_post_call(struct trace_event_file *file,
101 enum event_trigger_type tt)
102{
103 struct event_trigger_data *data;
104
105 list_for_each_entry_rcu(data, &file->triggers, list) {
106 if (data->paused)
107 continue;
108 if (data->cmd_ops->trigger_type & tt)
109 data->ops->func(data, NULL, NULL, NULL);
110 }
111}
112EXPORT_SYMBOL_GPL(event_triggers_post_call);
113
114#define SHOW_AVAILABLE_TRIGGERS (void *)(1UL)
115
116static void *trigger_next(struct seq_file *m, void *t, loff_t *pos)
117{
118 struct trace_event_file *event_file = event_file_data(m->private);
119
120 if (t == SHOW_AVAILABLE_TRIGGERS) {
121 (*pos)++;
122 return NULL;
123 }
124 return seq_list_next(t, &event_file->triggers, pos);
125}
126
127static void *trigger_start(struct seq_file *m, loff_t *pos)
128{
129 struct trace_event_file *event_file;
130
131 /* ->stop() is called even if ->start() fails */
132 mutex_lock(&event_mutex);
133 event_file = event_file_data(m->private);
134 if (unlikely(!event_file))
135 return ERR_PTR(-ENODEV);
136
137 if (list_empty(&event_file->triggers))
138 return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL;
139
140 return seq_list_start(&event_file->triggers, *pos);
141}
142
143static void trigger_stop(struct seq_file *m, void *t)
144{
145 mutex_unlock(&event_mutex);
146}
147
148static int trigger_show(struct seq_file *m, void *v)
149{
150 struct event_trigger_data *data;
151 struct event_command *p;
152
153 if (v == SHOW_AVAILABLE_TRIGGERS) {
154 seq_puts(m, "# Available triggers:\n");
155 seq_putc(m, '#');
156 mutex_lock(&trigger_cmd_mutex);
157 list_for_each_entry_reverse(p, &trigger_commands, list)
158 seq_printf(m, " %s", p->name);
159 seq_putc(m, '\n');
160 mutex_unlock(&trigger_cmd_mutex);
161 return 0;
162 }
163
164 data = list_entry(v, struct event_trigger_data, list);
165 data->ops->print(m, data->ops, data);
166
167 return 0;
168}
169
170static const struct seq_operations event_triggers_seq_ops = {
171 .start = trigger_start,
172 .next = trigger_next,
173 .stop = trigger_stop,
174 .show = trigger_show,
175};
176
177static int event_trigger_regex_open(struct inode *inode, struct file *file)
178{
179 int ret;
180
181 ret = security_locked_down(LOCKDOWN_TRACEFS);
182 if (ret)
183 return ret;
184
185 mutex_lock(&event_mutex);
186
187 if (unlikely(!event_file_data(file))) {
188 mutex_unlock(&event_mutex);
189 return -ENODEV;
190 }
191
192 if ((file->f_mode & FMODE_WRITE) &&
193 (file->f_flags & O_TRUNC)) {
194 struct trace_event_file *event_file;
195 struct event_command *p;
196
197 event_file = event_file_data(file);
198
199 list_for_each_entry(p, &trigger_commands, list) {
200 if (p->unreg_all)
201 p->unreg_all(event_file);
202 }
203 }
204
205 if (file->f_mode & FMODE_READ) {
206 ret = seq_open(file, &event_triggers_seq_ops);
207 if (!ret) {
208 struct seq_file *m = file->private_data;
209 m->private = file;
210 }
211 }
212
213 mutex_unlock(&event_mutex);
214
215 return ret;
216}
217
218int trigger_process_regex(struct trace_event_file *file, char *buff)
219{
220 char *command, *next;
221 struct event_command *p;
222 int ret = -EINVAL;
223
224 next = buff = skip_spaces(buff);
225 command = strsep(&next, ": \t");
226 if (next) {
227 next = skip_spaces(next);
228 if (!*next)
229 next = NULL;
230 }
231 command = (command[0] != '!') ? command : command + 1;
232
233 mutex_lock(&trigger_cmd_mutex);
234 list_for_each_entry(p, &trigger_commands, list) {
235 if (strcmp(p->name, command) == 0) {
236 ret = p->func(p, file, buff, command, next);
237 goto out_unlock;
238 }
239 }
240 out_unlock:
241 mutex_unlock(&trigger_cmd_mutex);
242
243 return ret;
244}
245
246static ssize_t event_trigger_regex_write(struct file *file,
247 const char __user *ubuf,
248 size_t cnt, loff_t *ppos)
249{
250 struct trace_event_file *event_file;
251 ssize_t ret;
252 char *buf;
253
254 if (!cnt)
255 return 0;
256
257 if (cnt >= PAGE_SIZE)
258 return -EINVAL;
259
260 buf = memdup_user_nul(ubuf, cnt);
261 if (IS_ERR(buf))
262 return PTR_ERR(buf);
263
264 strim(buf);
265
266 mutex_lock(&event_mutex);
267 event_file = event_file_data(file);
268 if (unlikely(!event_file)) {
269 mutex_unlock(&event_mutex);
270 kfree(buf);
271 return -ENODEV;
272 }
273 ret = trigger_process_regex(event_file, buf);
274 mutex_unlock(&event_mutex);
275
276 kfree(buf);
277 if (ret < 0)
278 goto out;
279
280 *ppos += cnt;
281 ret = cnt;
282 out:
283 return ret;
284}
285
286static int event_trigger_regex_release(struct inode *inode, struct file *file)
287{
288 mutex_lock(&event_mutex);
289
290 if (file->f_mode & FMODE_READ)
291 seq_release(inode, file);
292
293 mutex_unlock(&event_mutex);
294
295 return 0;
296}
297
298static ssize_t
299event_trigger_write(struct file *filp, const char __user *ubuf,
300 size_t cnt, loff_t *ppos)
301{
302 return event_trigger_regex_write(filp, ubuf, cnt, ppos);
303}
304
305static int
306event_trigger_open(struct inode *inode, struct file *filp)
307{
308 /* Checks for tracefs lockdown */
309 return event_trigger_regex_open(inode, filp);
310}
311
312static int
313event_trigger_release(struct inode *inode, struct file *file)
314{
315 return event_trigger_regex_release(inode, file);
316}
317
318const struct file_operations event_trigger_fops = {
319 .open = event_trigger_open,
320 .read = seq_read,
321 .write = event_trigger_write,
322 .llseek = tracing_lseek,
323 .release = event_trigger_release,
324};
325
326/*
327 * Currently we only register event commands from __init, so mark this
328 * __init too.
329 */
330__init int register_event_command(struct event_command *cmd)
331{
332 struct event_command *p;
333 int ret = 0;
334
335 mutex_lock(&trigger_cmd_mutex);
336 list_for_each_entry(p, &trigger_commands, list) {
337 if (strcmp(cmd->name, p->name) == 0) {
338 ret = -EBUSY;
339 goto out_unlock;
340 }
341 }
342 list_add(&cmd->list, &trigger_commands);
343 out_unlock:
344 mutex_unlock(&trigger_cmd_mutex);
345
346 return ret;
347}
348
349/*
350 * Currently we only unregister event commands from __init, so mark
351 * this __init too.
352 */
353__init int unregister_event_command(struct event_command *cmd)
354{
355 struct event_command *p, *n;
356 int ret = -ENODEV;
357
358 mutex_lock(&trigger_cmd_mutex);
359 list_for_each_entry_safe(p, n, &trigger_commands, list) {
360 if (strcmp(cmd->name, p->name) == 0) {
361 ret = 0;
362 list_del_init(&p->list);
363 goto out_unlock;
364 }
365 }
366 out_unlock:
367 mutex_unlock(&trigger_cmd_mutex);
368
369 return ret;
370}
371
372/**
373 * event_trigger_print - Generic event_trigger_ops @print implementation
374 * @name: The name of the event trigger
375 * @m: The seq_file being printed to
376 * @data: Trigger-specific data
377 * @filter_str: filter_str to print, if present
378 *
379 * Common implementation for event triggers to print themselves.
380 *
381 * Usually wrapped by a function that simply sets the @name of the
382 * trigger command and then invokes this.
383 *
384 * Return: 0 on success, errno otherwise
385 */
386static int
387event_trigger_print(const char *name, struct seq_file *m,
388 void *data, char *filter_str)
389{
390 long count = (long)data;
391
392 seq_puts(m, name);
393
394 if (count == -1)
395 seq_puts(m, ":unlimited");
396 else
397 seq_printf(m, ":count=%ld", count);
398
399 if (filter_str)
400 seq_printf(m, " if %s\n", filter_str);
401 else
402 seq_putc(m, '\n');
403
404 return 0;
405}
406
407/**
408 * event_trigger_init - Generic event_trigger_ops @init implementation
409 * @ops: The trigger ops associated with the trigger
410 * @data: Trigger-specific data
411 *
412 * Common implementation of event trigger initialization.
413 *
414 * Usually used directly as the @init method in event trigger
415 * implementations.
416 *
417 * Return: 0 on success, errno otherwise
418 */
419int event_trigger_init(struct event_trigger_ops *ops,
420 struct event_trigger_data *data)
421{
422 data->ref++;
423 return 0;
424}
425
426/**
427 * event_trigger_free - Generic event_trigger_ops @free implementation
428 * @ops: The trigger ops associated with the trigger
429 * @data: Trigger-specific data
430 *
431 * Common implementation of event trigger de-initialization.
432 *
433 * Usually used directly as the @free method in event trigger
434 * implementations.
435 */
436static void
437event_trigger_free(struct event_trigger_ops *ops,
438 struct event_trigger_data *data)
439{
440 if (WARN_ON_ONCE(data->ref <= 0))
441 return;
442
443 data->ref--;
444 if (!data->ref)
445 trigger_data_free(data);
446}
447
448int trace_event_trigger_enable_disable(struct trace_event_file *file,
449 int trigger_enable)
450{
451 int ret = 0;
452
453 if (trigger_enable) {
454 if (atomic_inc_return(&file->tm_ref) > 1)
455 return ret;
456 set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
457 ret = trace_event_enable_disable(file, 1, 1);
458 } else {
459 if (atomic_dec_return(&file->tm_ref) > 0)
460 return ret;
461 clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
462 ret = trace_event_enable_disable(file, 0, 1);
463 }
464
465 return ret;
466}
467
468/**
469 * clear_event_triggers - Clear all triggers associated with a trace array
470 * @tr: The trace array to clear
471 *
472 * For each trigger, the triggering event has its tm_ref decremented
473 * via trace_event_trigger_enable_disable(), and any associated event
474 * (in the case of enable/disable_event triggers) will have its sm_ref
475 * decremented via free()->trace_event_enable_disable(). That
476 * combination effectively reverses the soft-mode/trigger state added
477 * by trigger registration.
478 *
479 * Must be called with event_mutex held.
480 */
481void
482clear_event_triggers(struct trace_array *tr)
483{
484 struct trace_event_file *file;
485
486 list_for_each_entry(file, &tr->events, list) {
487 struct event_trigger_data *data, *n;
488 list_for_each_entry_safe(data, n, &file->triggers, list) {
489 trace_event_trigger_enable_disable(file, 0);
490 list_del_rcu(&data->list);
491 if (data->ops->free)
492 data->ops->free(data->ops, data);
493 }
494 }
495}
496
497/**
498 * update_cond_flag - Set or reset the TRIGGER_COND bit
499 * @file: The trace_event_file associated with the event
500 *
501 * If an event has triggers and any of those triggers has a filter or
502 * a post_trigger, trigger invocation needs to be deferred until after
503 * the current event has logged its data, and the event should have
504 * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be
505 * cleared.
506 */
507void update_cond_flag(struct trace_event_file *file)
508{
509 struct event_trigger_data *data;
510 bool set_cond = false;
511
512 lockdep_assert_held(&event_mutex);
513
514 list_for_each_entry(data, &file->triggers, list) {
515 if (data->filter || event_command_post_trigger(data->cmd_ops) ||
516 event_command_needs_rec(data->cmd_ops)) {
517 set_cond = true;
518 break;
519 }
520 }
521
522 if (set_cond)
523 set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
524 else
525 clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
526}
527
528/**
529 * register_trigger - Generic event_command @reg implementation
530 * @glob: The raw string used to register the trigger
531 * @ops: The trigger ops associated with the trigger
532 * @data: Trigger-specific data to associate with the trigger
533 * @file: The trace_event_file associated with the event
534 *
535 * Common implementation for event trigger registration.
536 *
537 * Usually used directly as the @reg method in event command
538 * implementations.
539 *
540 * Return: 0 on success, errno otherwise
541 */
542static int register_trigger(char *glob, struct event_trigger_ops *ops,
543 struct event_trigger_data *data,
544 struct trace_event_file *file)
545{
546 struct event_trigger_data *test;
547 int ret = 0;
548
549 lockdep_assert_held(&event_mutex);
550
551 list_for_each_entry(test, &file->triggers, list) {
552 if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) {
553 ret = -EEXIST;
554 goto out;
555 }
556 }
557
558 if (data->ops->init) {
559 ret = data->ops->init(data->ops, data);
560 if (ret < 0)
561 goto out;
562 }
563
564 list_add_rcu(&data->list, &file->triggers);
565 ret++;
566
567 update_cond_flag(file);
568 if (trace_event_trigger_enable_disable(file, 1) < 0) {
569 list_del_rcu(&data->list);
570 update_cond_flag(file);
571 ret--;
572 }
573out:
574 return ret;
575}
576
577/**
578 * unregister_trigger - Generic event_command @unreg implementation
579 * @glob: The raw string used to register the trigger
580 * @ops: The trigger ops associated with the trigger
581 * @test: Trigger-specific data used to find the trigger to remove
582 * @file: The trace_event_file associated with the event
583 *
584 * Common implementation for event trigger unregistration.
585 *
586 * Usually used directly as the @unreg method in event command
587 * implementations.
588 */
589static void unregister_trigger(char *glob, struct event_trigger_ops *ops,
590 struct event_trigger_data *test,
591 struct trace_event_file *file)
592{
593 struct event_trigger_data *data;
594 bool unregistered = false;
595
596 lockdep_assert_held(&event_mutex);
597
598 list_for_each_entry(data, &file->triggers, list) {
599 if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
600 unregistered = true;
601 list_del_rcu(&data->list);
602 trace_event_trigger_enable_disable(file, 0);
603 update_cond_flag(file);
604 break;
605 }
606 }
607
608 if (unregistered && data->ops->free)
609 data->ops->free(data->ops, data);
610}
611
612/**
613 * event_trigger_callback - Generic event_command @func implementation
614 * @cmd_ops: The command ops, used for trigger registration
615 * @file: The trace_event_file associated with the event
616 * @glob: The raw string used to register the trigger
617 * @cmd: The cmd portion of the string used to register the trigger
618 * @param: The params portion of the string used to register the trigger
619 *
620 * Common implementation for event command parsing and trigger
621 * instantiation.
622 *
623 * Usually used directly as the @func method in event command
624 * implementations.
625 *
626 * Return: 0 on success, errno otherwise
627 */
628static int
629event_trigger_callback(struct event_command *cmd_ops,
630 struct trace_event_file *file,
631 char *glob, char *cmd, char *param)
632{
633 struct event_trigger_data *trigger_data;
634 struct event_trigger_ops *trigger_ops;
635 char *trigger = NULL;
636 char *number;
637 int ret;
638
639 /* separate the trigger from the filter (t:n [if filter]) */
640 if (param && isdigit(param[0])) {
641 trigger = strsep(¶m, " \t");
642 if (param) {
643 param = skip_spaces(param);
644 if (!*param)
645 param = NULL;
646 }
647 }
648
649 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
650
651 ret = -ENOMEM;
652 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
653 if (!trigger_data)
654 goto out;
655
656 trigger_data->count = -1;
657 trigger_data->ops = trigger_ops;
658 trigger_data->cmd_ops = cmd_ops;
659 trigger_data->private_data = file;
660 INIT_LIST_HEAD(&trigger_data->list);
661 INIT_LIST_HEAD(&trigger_data->named_list);
662
663 if (glob[0] == '!') {
664 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
665 kfree(trigger_data);
666 ret = 0;
667 goto out;
668 }
669
670 if (trigger) {
671 number = strsep(&trigger, ":");
672
673 ret = -EINVAL;
674 if (!strlen(number))
675 goto out_free;
676
677 /*
678 * We use the callback data field (which is a pointer)
679 * as our counter.
680 */
681 ret = kstrtoul(number, 0, &trigger_data->count);
682 if (ret)
683 goto out_free;
684 }
685
686 if (!param) /* if param is non-empty, it's supposed to be a filter */
687 goto out_reg;
688
689 if (!cmd_ops->set_filter)
690 goto out_reg;
691
692 ret = cmd_ops->set_filter(param, trigger_data, file);
693 if (ret < 0)
694 goto out_free;
695
696 out_reg:
697 /* Up the trigger_data count to make sure reg doesn't free it on failure */
698 event_trigger_init(trigger_ops, trigger_data);
699 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
700 /*
701 * The above returns on success the # of functions enabled,
702 * but if it didn't find any functions it returns zero.
703 * Consider no functions a failure too.
704 */
705 if (!ret) {
706 cmd_ops->unreg(glob, trigger_ops, trigger_data, file);
707 ret = -ENOENT;
708 } else if (ret > 0)
709 ret = 0;
710
711 /* Down the counter of trigger_data or free it if not used anymore */
712 event_trigger_free(trigger_ops, trigger_data);
713 out:
714 return ret;
715
716 out_free:
717 if (cmd_ops->set_filter)
718 cmd_ops->set_filter(NULL, trigger_data, NULL);
719 kfree(trigger_data);
720 goto out;
721}
722
723/**
724 * set_trigger_filter - Generic event_command @set_filter implementation
725 * @filter_str: The filter string for the trigger, NULL to remove filter
726 * @trigger_data: Trigger-specific data
727 * @file: The trace_event_file associated with the event
728 *
729 * Common implementation for event command filter parsing and filter
730 * instantiation.
731 *
732 * Usually used directly as the @set_filter method in event command
733 * implementations.
734 *
735 * Also used to remove a filter (if filter_str = NULL).
736 *
737 * Return: 0 on success, errno otherwise
738 */
739int set_trigger_filter(char *filter_str,
740 struct event_trigger_data *trigger_data,
741 struct trace_event_file *file)
742{
743 struct event_trigger_data *data = trigger_data;
744 struct event_filter *filter = NULL, *tmp;
745 int ret = -EINVAL;
746 char *s;
747
748 if (!filter_str) /* clear the current filter */
749 goto assign;
750
751 s = strsep(&filter_str, " \t");
752
753 if (!strlen(s) || strcmp(s, "if") != 0)
754 goto out;
755
756 if (!filter_str)
757 goto out;
758
759 /* The filter is for the 'trigger' event, not the triggered event */
760 ret = create_event_filter(file->tr, file->event_call,
761 filter_str, false, &filter);
762 /*
763 * If create_event_filter() fails, filter still needs to be freed.
764 * Which the calling code will do with data->filter.
765 */
766 assign:
767 tmp = rcu_access_pointer(data->filter);
768
769 rcu_assign_pointer(data->filter, filter);
770
771 if (tmp) {
772 /* Make sure the call is done with the filter */
773 tracepoint_synchronize_unregister();
774 free_event_filter(tmp);
775 }
776
777 kfree(data->filter_str);
778 data->filter_str = NULL;
779
780 if (filter_str) {
781 data->filter_str = kstrdup(filter_str, GFP_KERNEL);
782 if (!data->filter_str) {
783 free_event_filter(rcu_access_pointer(data->filter));
784 data->filter = NULL;
785 ret = -ENOMEM;
786 }
787 }
788 out:
789 return ret;
790}
791
792static LIST_HEAD(named_triggers);
793
794/**
795 * find_named_trigger - Find the common named trigger associated with @name
796 * @name: The name of the set of named triggers to find the common data for
797 *
798 * Named triggers are sets of triggers that share a common set of
799 * trigger data. The first named trigger registered with a given name
800 * owns the common trigger data that the others subsequently
801 * registered with the same name will reference. This function
802 * returns the common trigger data associated with that first
803 * registered instance.
804 *
805 * Return: the common trigger data for the given named trigger on
806 * success, NULL otherwise.
807 */
808struct event_trigger_data *find_named_trigger(const char *name)
809{
810 struct event_trigger_data *data;
811
812 if (!name)
813 return NULL;
814
815 list_for_each_entry(data, &named_triggers, named_list) {
816 if (data->named_data)
817 continue;
818 if (strcmp(data->name, name) == 0)
819 return data;
820 }
821
822 return NULL;
823}
824
825/**
826 * is_named_trigger - determine if a given trigger is a named trigger
827 * @test: The trigger data to test
828 *
829 * Return: true if 'test' is a named trigger, false otherwise.
830 */
831bool is_named_trigger(struct event_trigger_data *test)
832{
833 struct event_trigger_data *data;
834
835 list_for_each_entry(data, &named_triggers, named_list) {
836 if (test == data)
837 return true;
838 }
839
840 return false;
841}
842
843/**
844 * save_named_trigger - save the trigger in the named trigger list
845 * @name: The name of the named trigger set
846 * @data: The trigger data to save
847 *
848 * Return: 0 if successful, negative error otherwise.
849 */
850int save_named_trigger(const char *name, struct event_trigger_data *data)
851{
852 data->name = kstrdup(name, GFP_KERNEL);
853 if (!data->name)
854 return -ENOMEM;
855
856 list_add(&data->named_list, &named_triggers);
857
858 return 0;
859}
860
861/**
862 * del_named_trigger - delete a trigger from the named trigger list
863 * @data: The trigger data to delete
864 */
865void del_named_trigger(struct event_trigger_data *data)
866{
867 kfree(data->name);
868 data->name = NULL;
869
870 list_del(&data->named_list);
871}
872
873static void __pause_named_trigger(struct event_trigger_data *data, bool pause)
874{
875 struct event_trigger_data *test;
876
877 list_for_each_entry(test, &named_triggers, named_list) {
878 if (strcmp(test->name, data->name) == 0) {
879 if (pause) {
880 test->paused_tmp = test->paused;
881 test->paused = true;
882 } else {
883 test->paused = test->paused_tmp;
884 }
885 }
886 }
887}
888
889/**
890 * pause_named_trigger - Pause all named triggers with the same name
891 * @data: The trigger data of a named trigger to pause
892 *
893 * Pauses a named trigger along with all other triggers having the
894 * same name. Because named triggers share a common set of data,
895 * pausing only one is meaningless, so pausing one named trigger needs
896 * to pause all triggers with the same name.
897 */
898void pause_named_trigger(struct event_trigger_data *data)
899{
900 __pause_named_trigger(data, true);
901}
902
903/**
904 * unpause_named_trigger - Un-pause all named triggers with the same name
905 * @data: The trigger data of a named trigger to unpause
906 *
907 * Un-pauses a named trigger along with all other triggers having the
908 * same name. Because named triggers share a common set of data,
909 * unpausing only one is meaningless, so unpausing one named trigger
910 * needs to unpause all triggers with the same name.
911 */
912void unpause_named_trigger(struct event_trigger_data *data)
913{
914 __pause_named_trigger(data, false);
915}
916
917/**
918 * set_named_trigger_data - Associate common named trigger data
919 * @data: The trigger data to associate
920 * @named_data: The common named trigger to be associated
921 *
922 * Named triggers are sets of triggers that share a common set of
923 * trigger data. The first named trigger registered with a given name
924 * owns the common trigger data that the others subsequently
925 * registered with the same name will reference. This function
926 * associates the common trigger data from the first trigger with the
927 * given trigger.
928 */
929void set_named_trigger_data(struct event_trigger_data *data,
930 struct event_trigger_data *named_data)
931{
932 data->named_data = named_data;
933}
934
935struct event_trigger_data *
936get_named_trigger_data(struct event_trigger_data *data)
937{
938 return data->named_data;
939}
940
941static void
942traceon_trigger(struct event_trigger_data *data,
943 struct trace_buffer *buffer, void *rec,
944 struct ring_buffer_event *event)
945{
946 if (tracing_is_on())
947 return;
948
949 tracing_on();
950}
951
952static void
953traceon_count_trigger(struct event_trigger_data *data,
954 struct trace_buffer *buffer, void *rec,
955 struct ring_buffer_event *event)
956{
957 if (tracing_is_on())
958 return;
959
960 if (!data->count)
961 return;
962
963 if (data->count != -1)
964 (data->count)--;
965
966 tracing_on();
967}
968
969static void
970traceoff_trigger(struct event_trigger_data *data,
971 struct trace_buffer *buffer, void *rec,
972 struct ring_buffer_event *event)
973{
974 if (!tracing_is_on())
975 return;
976
977 tracing_off();
978}
979
980static void
981traceoff_count_trigger(struct event_trigger_data *data,
982 struct trace_buffer *buffer, void *rec,
983 struct ring_buffer_event *event)
984{
985 if (!tracing_is_on())
986 return;
987
988 if (!data->count)
989 return;
990
991 if (data->count != -1)
992 (data->count)--;
993
994 tracing_off();
995}
996
997static int
998traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
999 struct event_trigger_data *data)
1000{
1001 return event_trigger_print("traceon", m, (void *)data->count,
1002 data->filter_str);
1003}
1004
1005static int
1006traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1007 struct event_trigger_data *data)
1008{
1009 return event_trigger_print("traceoff", m, (void *)data->count,
1010 data->filter_str);
1011}
1012
1013static struct event_trigger_ops traceon_trigger_ops = {
1014 .func = traceon_trigger,
1015 .print = traceon_trigger_print,
1016 .init = event_trigger_init,
1017 .free = event_trigger_free,
1018};
1019
1020static struct event_trigger_ops traceon_count_trigger_ops = {
1021 .func = traceon_count_trigger,
1022 .print = traceon_trigger_print,
1023 .init = event_trigger_init,
1024 .free = event_trigger_free,
1025};
1026
1027static struct event_trigger_ops traceoff_trigger_ops = {
1028 .func = traceoff_trigger,
1029 .print = traceoff_trigger_print,
1030 .init = event_trigger_init,
1031 .free = event_trigger_free,
1032};
1033
1034static struct event_trigger_ops traceoff_count_trigger_ops = {
1035 .func = traceoff_count_trigger,
1036 .print = traceoff_trigger_print,
1037 .init = event_trigger_init,
1038 .free = event_trigger_free,
1039};
1040
1041static struct event_trigger_ops *
1042onoff_get_trigger_ops(char *cmd, char *param)
1043{
1044 struct event_trigger_ops *ops;
1045
1046 /* we register both traceon and traceoff to this callback */
1047 if (strcmp(cmd, "traceon") == 0)
1048 ops = param ? &traceon_count_trigger_ops :
1049 &traceon_trigger_ops;
1050 else
1051 ops = param ? &traceoff_count_trigger_ops :
1052 &traceoff_trigger_ops;
1053
1054 return ops;
1055}
1056
1057static struct event_command trigger_traceon_cmd = {
1058 .name = "traceon",
1059 .trigger_type = ETT_TRACE_ONOFF,
1060 .func = event_trigger_callback,
1061 .reg = register_trigger,
1062 .unreg = unregister_trigger,
1063 .get_trigger_ops = onoff_get_trigger_ops,
1064 .set_filter = set_trigger_filter,
1065};
1066
1067static struct event_command trigger_traceoff_cmd = {
1068 .name = "traceoff",
1069 .trigger_type = ETT_TRACE_ONOFF,
1070 .flags = EVENT_CMD_FL_POST_TRIGGER,
1071 .func = event_trigger_callback,
1072 .reg = register_trigger,
1073 .unreg = unregister_trigger,
1074 .get_trigger_ops = onoff_get_trigger_ops,
1075 .set_filter = set_trigger_filter,
1076};
1077
1078#ifdef CONFIG_TRACER_SNAPSHOT
1079static void
1080snapshot_trigger(struct event_trigger_data *data,
1081 struct trace_buffer *buffer, void *rec,
1082 struct ring_buffer_event *event)
1083{
1084 struct trace_event_file *file = data->private_data;
1085
1086 if (file)
1087 tracing_snapshot_instance(file->tr);
1088 else
1089 tracing_snapshot();
1090}
1091
1092static void
1093snapshot_count_trigger(struct event_trigger_data *data,
1094 struct trace_buffer *buffer, void *rec,
1095 struct ring_buffer_event *event)
1096{
1097 if (!data->count)
1098 return;
1099
1100 if (data->count != -1)
1101 (data->count)--;
1102
1103 snapshot_trigger(data, buffer, rec, event);
1104}
1105
1106static int
1107register_snapshot_trigger(char *glob, struct event_trigger_ops *ops,
1108 struct event_trigger_data *data,
1109 struct trace_event_file *file)
1110{
1111 if (tracing_alloc_snapshot_instance(file->tr) != 0)
1112 return 0;
1113
1114 return register_trigger(glob, ops, data, file);
1115}
1116
1117static int
1118snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1119 struct event_trigger_data *data)
1120{
1121 return event_trigger_print("snapshot", m, (void *)data->count,
1122 data->filter_str);
1123}
1124
1125static struct event_trigger_ops snapshot_trigger_ops = {
1126 .func = snapshot_trigger,
1127 .print = snapshot_trigger_print,
1128 .init = event_trigger_init,
1129 .free = event_trigger_free,
1130};
1131
1132static struct event_trigger_ops snapshot_count_trigger_ops = {
1133 .func = snapshot_count_trigger,
1134 .print = snapshot_trigger_print,
1135 .init = event_trigger_init,
1136 .free = event_trigger_free,
1137};
1138
1139static struct event_trigger_ops *
1140snapshot_get_trigger_ops(char *cmd, char *param)
1141{
1142 return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
1143}
1144
1145static struct event_command trigger_snapshot_cmd = {
1146 .name = "snapshot",
1147 .trigger_type = ETT_SNAPSHOT,
1148 .func = event_trigger_callback,
1149 .reg = register_snapshot_trigger,
1150 .unreg = unregister_trigger,
1151 .get_trigger_ops = snapshot_get_trigger_ops,
1152 .set_filter = set_trigger_filter,
1153};
1154
1155static __init int register_trigger_snapshot_cmd(void)
1156{
1157 int ret;
1158
1159 ret = register_event_command(&trigger_snapshot_cmd);
1160 WARN_ON(ret < 0);
1161
1162 return ret;
1163}
1164#else
1165static __init int register_trigger_snapshot_cmd(void) { return 0; }
1166#endif /* CONFIG_TRACER_SNAPSHOT */
1167
1168#ifdef CONFIG_STACKTRACE
1169#ifdef CONFIG_UNWINDER_ORC
1170/* Skip 2:
1171 * event_triggers_post_call()
1172 * trace_event_raw_event_xxx()
1173 */
1174# define STACK_SKIP 2
1175#else
1176/*
1177 * Skip 4:
1178 * stacktrace_trigger()
1179 * event_triggers_post_call()
1180 * trace_event_buffer_commit()
1181 * trace_event_raw_event_xxx()
1182 */
1183#define STACK_SKIP 4
1184#endif
1185
1186static void
1187stacktrace_trigger(struct event_trigger_data *data,
1188 struct trace_buffer *buffer, void *rec,
1189 struct ring_buffer_event *event)
1190{
1191 trace_dump_stack(STACK_SKIP);
1192}
1193
1194static void
1195stacktrace_count_trigger(struct event_trigger_data *data,
1196 struct trace_buffer *buffer, void *rec,
1197 struct ring_buffer_event *event)
1198{
1199 if (!data->count)
1200 return;
1201
1202 if (data->count != -1)
1203 (data->count)--;
1204
1205 stacktrace_trigger(data, buffer, rec, event);
1206}
1207
1208static int
1209stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1210 struct event_trigger_data *data)
1211{
1212 return event_trigger_print("stacktrace", m, (void *)data->count,
1213 data->filter_str);
1214}
1215
1216static struct event_trigger_ops stacktrace_trigger_ops = {
1217 .func = stacktrace_trigger,
1218 .print = stacktrace_trigger_print,
1219 .init = event_trigger_init,
1220 .free = event_trigger_free,
1221};
1222
1223static struct event_trigger_ops stacktrace_count_trigger_ops = {
1224 .func = stacktrace_count_trigger,
1225 .print = stacktrace_trigger_print,
1226 .init = event_trigger_init,
1227 .free = event_trigger_free,
1228};
1229
1230static struct event_trigger_ops *
1231stacktrace_get_trigger_ops(char *cmd, char *param)
1232{
1233 return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
1234}
1235
1236static struct event_command trigger_stacktrace_cmd = {
1237 .name = "stacktrace",
1238 .trigger_type = ETT_STACKTRACE,
1239 .flags = EVENT_CMD_FL_POST_TRIGGER,
1240 .func = event_trigger_callback,
1241 .reg = register_trigger,
1242 .unreg = unregister_trigger,
1243 .get_trigger_ops = stacktrace_get_trigger_ops,
1244 .set_filter = set_trigger_filter,
1245};
1246
1247static __init int register_trigger_stacktrace_cmd(void)
1248{
1249 int ret;
1250
1251 ret = register_event_command(&trigger_stacktrace_cmd);
1252 WARN_ON(ret < 0);
1253
1254 return ret;
1255}
1256#else
1257static __init int register_trigger_stacktrace_cmd(void) { return 0; }
1258#endif /* CONFIG_STACKTRACE */
1259
1260static __init void unregister_trigger_traceon_traceoff_cmds(void)
1261{
1262 unregister_event_command(&trigger_traceon_cmd);
1263 unregister_event_command(&trigger_traceoff_cmd);
1264}
1265
1266static void
1267event_enable_trigger(struct event_trigger_data *data,
1268 struct trace_buffer *buffer, void *rec,
1269 struct ring_buffer_event *event)
1270{
1271 struct enable_trigger_data *enable_data = data->private_data;
1272
1273 if (enable_data->enable)
1274 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1275 else
1276 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1277}
1278
1279static void
1280event_enable_count_trigger(struct event_trigger_data *data,
1281 struct trace_buffer *buffer, void *rec,
1282 struct ring_buffer_event *event)
1283{
1284 struct enable_trigger_data *enable_data = data->private_data;
1285
1286 if (!data->count)
1287 return;
1288
1289 /* Skip if the event is in a state we want to switch to */
1290 if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
1291 return;
1292
1293 if (data->count != -1)
1294 (data->count)--;
1295
1296 event_enable_trigger(data, buffer, rec, event);
1297}
1298
1299int event_enable_trigger_print(struct seq_file *m,
1300 struct event_trigger_ops *ops,
1301 struct event_trigger_data *data)
1302{
1303 struct enable_trigger_data *enable_data = data->private_data;
1304
1305 seq_printf(m, "%s:%s:%s",
1306 enable_data->hist ?
1307 (enable_data->enable ? ENABLE_HIST_STR : DISABLE_HIST_STR) :
1308 (enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR),
1309 enable_data->file->event_call->class->system,
1310 trace_event_name(enable_data->file->event_call));
1311
1312 if (data->count == -1)
1313 seq_puts(m, ":unlimited");
1314 else
1315 seq_printf(m, ":count=%ld", data->count);
1316
1317 if (data->filter_str)
1318 seq_printf(m, " if %s\n", data->filter_str);
1319 else
1320 seq_putc(m, '\n');
1321
1322 return 0;
1323}
1324
1325void event_enable_trigger_free(struct event_trigger_ops *ops,
1326 struct event_trigger_data *data)
1327{
1328 struct enable_trigger_data *enable_data = data->private_data;
1329
1330 if (WARN_ON_ONCE(data->ref <= 0))
1331 return;
1332
1333 data->ref--;
1334 if (!data->ref) {
1335 /* Remove the SOFT_MODE flag */
1336 trace_event_enable_disable(enable_data->file, 0, 1);
1337 module_put(enable_data->file->event_call->mod);
1338 trigger_data_free(data);
1339 kfree(enable_data);
1340 }
1341}
1342
1343static struct event_trigger_ops event_enable_trigger_ops = {
1344 .func = event_enable_trigger,
1345 .print = event_enable_trigger_print,
1346 .init = event_trigger_init,
1347 .free = event_enable_trigger_free,
1348};
1349
1350static struct event_trigger_ops event_enable_count_trigger_ops = {
1351 .func = event_enable_count_trigger,
1352 .print = event_enable_trigger_print,
1353 .init = event_trigger_init,
1354 .free = event_enable_trigger_free,
1355};
1356
1357static struct event_trigger_ops event_disable_trigger_ops = {
1358 .func = event_enable_trigger,
1359 .print = event_enable_trigger_print,
1360 .init = event_trigger_init,
1361 .free = event_enable_trigger_free,
1362};
1363
1364static struct event_trigger_ops event_disable_count_trigger_ops = {
1365 .func = event_enable_count_trigger,
1366 .print = event_enable_trigger_print,
1367 .init = event_trigger_init,
1368 .free = event_enable_trigger_free,
1369};
1370
1371int event_enable_trigger_func(struct event_command *cmd_ops,
1372 struct trace_event_file *file,
1373 char *glob, char *cmd, char *param)
1374{
1375 struct trace_event_file *event_enable_file;
1376 struct enable_trigger_data *enable_data;
1377 struct event_trigger_data *trigger_data;
1378 struct event_trigger_ops *trigger_ops;
1379 struct trace_array *tr = file->tr;
1380 const char *system;
1381 const char *event;
1382 bool hist = false;
1383 char *trigger;
1384 char *number;
1385 bool enable;
1386 int ret;
1387
1388 if (!param)
1389 return -EINVAL;
1390
1391 /* separate the trigger from the filter (s:e:n [if filter]) */
1392 trigger = strsep(¶m, " \t");
1393 if (!trigger)
1394 return -EINVAL;
1395 if (param) {
1396 param = skip_spaces(param);
1397 if (!*param)
1398 param = NULL;
1399 }
1400
1401 system = strsep(&trigger, ":");
1402 if (!trigger)
1403 return -EINVAL;
1404
1405 event = strsep(&trigger, ":");
1406
1407 ret = -EINVAL;
1408 event_enable_file = find_event_file(tr, system, event);
1409 if (!event_enable_file)
1410 goto out;
1411
1412#ifdef CONFIG_HIST_TRIGGERS
1413 hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) ||
1414 (strcmp(cmd, DISABLE_HIST_STR) == 0));
1415
1416 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1417 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1418#else
1419 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1420#endif
1421 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
1422
1423 ret = -ENOMEM;
1424 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
1425 if (!trigger_data)
1426 goto out;
1427
1428 enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
1429 if (!enable_data) {
1430 kfree(trigger_data);
1431 goto out;
1432 }
1433
1434 trigger_data->count = -1;
1435 trigger_data->ops = trigger_ops;
1436 trigger_data->cmd_ops = cmd_ops;
1437 INIT_LIST_HEAD(&trigger_data->list);
1438 RCU_INIT_POINTER(trigger_data->filter, NULL);
1439
1440 enable_data->hist = hist;
1441 enable_data->enable = enable;
1442 enable_data->file = event_enable_file;
1443 trigger_data->private_data = enable_data;
1444
1445 if (glob[0] == '!') {
1446 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
1447 kfree(trigger_data);
1448 kfree(enable_data);
1449 ret = 0;
1450 goto out;
1451 }
1452
1453 /* Up the trigger_data count to make sure nothing frees it on failure */
1454 event_trigger_init(trigger_ops, trigger_data);
1455
1456 if (trigger) {
1457 number = strsep(&trigger, ":");
1458
1459 ret = -EINVAL;
1460 if (!strlen(number))
1461 goto out_free;
1462
1463 /*
1464 * We use the callback data field (which is a pointer)
1465 * as our counter.
1466 */
1467 ret = kstrtoul(number, 0, &trigger_data->count);
1468 if (ret)
1469 goto out_free;
1470 }
1471
1472 if (!param) /* if param is non-empty, it's supposed to be a filter */
1473 goto out_reg;
1474
1475 if (!cmd_ops->set_filter)
1476 goto out_reg;
1477
1478 ret = cmd_ops->set_filter(param, trigger_data, file);
1479 if (ret < 0)
1480 goto out_free;
1481
1482 out_reg:
1483 /* Don't let event modules unload while probe registered */
1484 ret = try_module_get(event_enable_file->event_call->mod);
1485 if (!ret) {
1486 ret = -EBUSY;
1487 goto out_free;
1488 }
1489
1490 ret = trace_event_enable_disable(event_enable_file, 1, 1);
1491 if (ret < 0)
1492 goto out_put;
1493 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1494 /*
1495 * The above returns on success the # of functions enabled,
1496 * but if it didn't find any functions it returns zero.
1497 * Consider no functions a failure too.
1498 */
1499 if (!ret) {
1500 ret = -ENOENT;
1501 goto out_disable;
1502 } else if (ret < 0)
1503 goto out_disable;
1504 /* Just return zero, not the number of enabled functions */
1505 ret = 0;
1506 event_trigger_free(trigger_ops, trigger_data);
1507 out:
1508 return ret;
1509
1510 out_disable:
1511 trace_event_enable_disable(event_enable_file, 0, 1);
1512 out_put:
1513 module_put(event_enable_file->event_call->mod);
1514 out_free:
1515 if (cmd_ops->set_filter)
1516 cmd_ops->set_filter(NULL, trigger_data, NULL);
1517 event_trigger_free(trigger_ops, trigger_data);
1518 kfree(enable_data);
1519 goto out;
1520}
1521
1522int event_enable_register_trigger(char *glob,
1523 struct event_trigger_ops *ops,
1524 struct event_trigger_data *data,
1525 struct trace_event_file *file)
1526{
1527 struct enable_trigger_data *enable_data = data->private_data;
1528 struct enable_trigger_data *test_enable_data;
1529 struct event_trigger_data *test;
1530 int ret = 0;
1531
1532 lockdep_assert_held(&event_mutex);
1533
1534 list_for_each_entry(test, &file->triggers, list) {
1535 test_enable_data = test->private_data;
1536 if (test_enable_data &&
1537 (test->cmd_ops->trigger_type ==
1538 data->cmd_ops->trigger_type) &&
1539 (test_enable_data->file == enable_data->file)) {
1540 ret = -EEXIST;
1541 goto out;
1542 }
1543 }
1544
1545 if (data->ops->init) {
1546 ret = data->ops->init(data->ops, data);
1547 if (ret < 0)
1548 goto out;
1549 }
1550
1551 list_add_rcu(&data->list, &file->triggers);
1552 ret++;
1553
1554 update_cond_flag(file);
1555 if (trace_event_trigger_enable_disable(file, 1) < 0) {
1556 list_del_rcu(&data->list);
1557 update_cond_flag(file);
1558 ret--;
1559 }
1560out:
1561 return ret;
1562}
1563
1564void event_enable_unregister_trigger(char *glob,
1565 struct event_trigger_ops *ops,
1566 struct event_trigger_data *test,
1567 struct trace_event_file *file)
1568{
1569 struct enable_trigger_data *test_enable_data = test->private_data;
1570 struct enable_trigger_data *enable_data;
1571 struct event_trigger_data *data;
1572 bool unregistered = false;
1573
1574 lockdep_assert_held(&event_mutex);
1575
1576 list_for_each_entry(data, &file->triggers, list) {
1577 enable_data = data->private_data;
1578 if (enable_data &&
1579 (data->cmd_ops->trigger_type ==
1580 test->cmd_ops->trigger_type) &&
1581 (enable_data->file == test_enable_data->file)) {
1582 unregistered = true;
1583 list_del_rcu(&data->list);
1584 trace_event_trigger_enable_disable(file, 0);
1585 update_cond_flag(file);
1586 break;
1587 }
1588 }
1589
1590 if (unregistered && data->ops->free)
1591 data->ops->free(data->ops, data);
1592}
1593
1594static struct event_trigger_ops *
1595event_enable_get_trigger_ops(char *cmd, char *param)
1596{
1597 struct event_trigger_ops *ops;
1598 bool enable;
1599
1600#ifdef CONFIG_HIST_TRIGGERS
1601 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1602 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1603#else
1604 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1605#endif
1606 if (enable)
1607 ops = param ? &event_enable_count_trigger_ops :
1608 &event_enable_trigger_ops;
1609 else
1610 ops = param ? &event_disable_count_trigger_ops :
1611 &event_disable_trigger_ops;
1612
1613 return ops;
1614}
1615
1616static struct event_command trigger_enable_cmd = {
1617 .name = ENABLE_EVENT_STR,
1618 .trigger_type = ETT_EVENT_ENABLE,
1619 .func = event_enable_trigger_func,
1620 .reg = event_enable_register_trigger,
1621 .unreg = event_enable_unregister_trigger,
1622 .get_trigger_ops = event_enable_get_trigger_ops,
1623 .set_filter = set_trigger_filter,
1624};
1625
1626static struct event_command trigger_disable_cmd = {
1627 .name = DISABLE_EVENT_STR,
1628 .trigger_type = ETT_EVENT_ENABLE,
1629 .func = event_enable_trigger_func,
1630 .reg = event_enable_register_trigger,
1631 .unreg = event_enable_unregister_trigger,
1632 .get_trigger_ops = event_enable_get_trigger_ops,
1633 .set_filter = set_trigger_filter,
1634};
1635
1636static __init void unregister_trigger_enable_disable_cmds(void)
1637{
1638 unregister_event_command(&trigger_enable_cmd);
1639 unregister_event_command(&trigger_disable_cmd);
1640}
1641
1642static __init int register_trigger_enable_disable_cmds(void)
1643{
1644 int ret;
1645
1646 ret = register_event_command(&trigger_enable_cmd);
1647 if (WARN_ON(ret < 0))
1648 return ret;
1649 ret = register_event_command(&trigger_disable_cmd);
1650 if (WARN_ON(ret < 0))
1651 unregister_trigger_enable_disable_cmds();
1652
1653 return ret;
1654}
1655
1656static __init int register_trigger_traceon_traceoff_cmds(void)
1657{
1658 int ret;
1659
1660 ret = register_event_command(&trigger_traceon_cmd);
1661 if (WARN_ON(ret < 0))
1662 return ret;
1663 ret = register_event_command(&trigger_traceoff_cmd);
1664 if (WARN_ON(ret < 0))
1665 unregister_trigger_traceon_traceoff_cmds();
1666
1667 return ret;
1668}
1669
1670__init int register_trigger_cmds(void)
1671{
1672 register_trigger_traceon_traceoff_cmds();
1673 register_trigger_snapshot_cmd();
1674 register_trigger_stacktrace_cmd();
1675 register_trigger_enable_disable_cmds();
1676 register_trigger_hist_enable_disable_cmds();
1677 register_trigger_hist_cmd();
1678
1679 return 0;
1680}