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