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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 return NULL;
121
122 return seq_list_next(t, &event_file->triggers, pos);
123}
124
125static void *trigger_start(struct seq_file *m, loff_t *pos)
126{
127 struct trace_event_file *event_file;
128
129 /* ->stop() is called even if ->start() fails */
130 mutex_lock(&event_mutex);
131 event_file = event_file_data(m->private);
132 if (unlikely(!event_file))
133 return ERR_PTR(-ENODEV);
134
135 if (list_empty(&event_file->triggers))
136 return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL;
137
138 return seq_list_start(&event_file->triggers, *pos);
139}
140
141static void trigger_stop(struct seq_file *m, void *t)
142{
143 mutex_unlock(&event_mutex);
144}
145
146static int trigger_show(struct seq_file *m, void *v)
147{
148 struct event_trigger_data *data;
149 struct event_command *p;
150
151 if (v == SHOW_AVAILABLE_TRIGGERS) {
152 seq_puts(m, "# Available triggers:\n");
153 seq_putc(m, '#');
154 mutex_lock(&trigger_cmd_mutex);
155 list_for_each_entry_reverse(p, &trigger_commands, list)
156 seq_printf(m, " %s", p->name);
157 seq_putc(m, '\n');
158 mutex_unlock(&trigger_cmd_mutex);
159 return 0;
160 }
161
162 data = list_entry(v, struct event_trigger_data, list);
163 data->ops->print(m, data->ops, data);
164
165 return 0;
166}
167
168static const struct seq_operations event_triggers_seq_ops = {
169 .start = trigger_start,
170 .next = trigger_next,
171 .stop = trigger_stop,
172 .show = trigger_show,
173};
174
175static int event_trigger_regex_open(struct inode *inode, struct file *file)
176{
177 int ret;
178
179 ret = security_locked_down(LOCKDOWN_TRACEFS);
180 if (ret)
181 return ret;
182
183 mutex_lock(&event_mutex);
184
185 if (unlikely(!event_file_data(file))) {
186 mutex_unlock(&event_mutex);
187 return -ENODEV;
188 }
189
190 if ((file->f_mode & FMODE_WRITE) &&
191 (file->f_flags & O_TRUNC)) {
192 struct trace_event_file *event_file;
193 struct event_command *p;
194
195 event_file = event_file_data(file);
196
197 list_for_each_entry(p, &trigger_commands, list) {
198 if (p->unreg_all)
199 p->unreg_all(event_file);
200 }
201 }
202
203 if (file->f_mode & FMODE_READ) {
204 ret = seq_open(file, &event_triggers_seq_ops);
205 if (!ret) {
206 struct seq_file *m = file->private_data;
207 m->private = file;
208 }
209 }
210
211 mutex_unlock(&event_mutex);
212
213 return ret;
214}
215
216static int trigger_process_regex(struct trace_event_file *file, char *buff)
217{
218 char *command, *next = buff;
219 struct event_command *p;
220 int ret = -EINVAL;
221
222 command = strsep(&next, ": \t");
223 command = (command[0] != '!') ? command : command + 1;
224
225 mutex_lock(&trigger_cmd_mutex);
226 list_for_each_entry(p, &trigger_commands, list) {
227 if (strcmp(p->name, command) == 0) {
228 ret = p->func(p, file, buff, command, next);
229 goto out_unlock;
230 }
231 }
232 out_unlock:
233 mutex_unlock(&trigger_cmd_mutex);
234
235 return ret;
236}
237
238static ssize_t event_trigger_regex_write(struct file *file,
239 const char __user *ubuf,
240 size_t cnt, loff_t *ppos)
241{
242 struct trace_event_file *event_file;
243 ssize_t ret;
244 char *buf;
245
246 if (!cnt)
247 return 0;
248
249 if (cnt >= PAGE_SIZE)
250 return -EINVAL;
251
252 buf = memdup_user_nul(ubuf, cnt);
253 if (IS_ERR(buf))
254 return PTR_ERR(buf);
255
256 strim(buf);
257
258 mutex_lock(&event_mutex);
259 event_file = event_file_data(file);
260 if (unlikely(!event_file)) {
261 mutex_unlock(&event_mutex);
262 kfree(buf);
263 return -ENODEV;
264 }
265 ret = trigger_process_regex(event_file, buf);
266 mutex_unlock(&event_mutex);
267
268 kfree(buf);
269 if (ret < 0)
270 goto out;
271
272 *ppos += cnt;
273 ret = cnt;
274 out:
275 return ret;
276}
277
278static int event_trigger_regex_release(struct inode *inode, struct file *file)
279{
280 mutex_lock(&event_mutex);
281
282 if (file->f_mode & FMODE_READ)
283 seq_release(inode, file);
284
285 mutex_unlock(&event_mutex);
286
287 return 0;
288}
289
290static ssize_t
291event_trigger_write(struct file *filp, const char __user *ubuf,
292 size_t cnt, loff_t *ppos)
293{
294 return event_trigger_regex_write(filp, ubuf, cnt, ppos);
295}
296
297static int
298event_trigger_open(struct inode *inode, struct file *filp)
299{
300 /* Checks for tracefs lockdown */
301 return event_trigger_regex_open(inode, filp);
302}
303
304static int
305event_trigger_release(struct inode *inode, struct file *file)
306{
307 return event_trigger_regex_release(inode, file);
308}
309
310const struct file_operations event_trigger_fops = {
311 .open = event_trigger_open,
312 .read = seq_read,
313 .write = event_trigger_write,
314 .llseek = tracing_lseek,
315 .release = event_trigger_release,
316};
317
318/*
319 * Currently we only register event commands from __init, so mark this
320 * __init too.
321 */
322__init int register_event_command(struct event_command *cmd)
323{
324 struct event_command *p;
325 int ret = 0;
326
327 mutex_lock(&trigger_cmd_mutex);
328 list_for_each_entry(p, &trigger_commands, list) {
329 if (strcmp(cmd->name, p->name) == 0) {
330 ret = -EBUSY;
331 goto out_unlock;
332 }
333 }
334 list_add(&cmd->list, &trigger_commands);
335 out_unlock:
336 mutex_unlock(&trigger_cmd_mutex);
337
338 return ret;
339}
340
341/*
342 * Currently we only unregister event commands from __init, so mark
343 * this __init too.
344 */
345__init int unregister_event_command(struct event_command *cmd)
346{
347 struct event_command *p, *n;
348 int ret = -ENODEV;
349
350 mutex_lock(&trigger_cmd_mutex);
351 list_for_each_entry_safe(p, n, &trigger_commands, list) {
352 if (strcmp(cmd->name, p->name) == 0) {
353 ret = 0;
354 list_del_init(&p->list);
355 goto out_unlock;
356 }
357 }
358 out_unlock:
359 mutex_unlock(&trigger_cmd_mutex);
360
361 return ret;
362}
363
364/**
365 * event_trigger_print - Generic event_trigger_ops @print implementation
366 * @name: The name of the event trigger
367 * @m: The seq_file being printed to
368 * @data: Trigger-specific data
369 * @filter_str: filter_str to print, if present
370 *
371 * Common implementation for event triggers to print themselves.
372 *
373 * Usually wrapped by a function that simply sets the @name of the
374 * trigger command and then invokes this.
375 *
376 * Return: 0 on success, errno otherwise
377 */
378static int
379event_trigger_print(const char *name, struct seq_file *m,
380 void *data, char *filter_str)
381{
382 long count = (long)data;
383
384 seq_puts(m, name);
385
386 if (count == -1)
387 seq_puts(m, ":unlimited");
388 else
389 seq_printf(m, ":count=%ld", count);
390
391 if (filter_str)
392 seq_printf(m, " if %s\n", filter_str);
393 else
394 seq_putc(m, '\n');
395
396 return 0;
397}
398
399/**
400 * event_trigger_init - Generic event_trigger_ops @init implementation
401 * @ops: The trigger ops associated with the trigger
402 * @data: Trigger-specific data
403 *
404 * Common implementation of event trigger initialization.
405 *
406 * Usually used directly as the @init method in event trigger
407 * implementations.
408 *
409 * Return: 0 on success, errno otherwise
410 */
411int event_trigger_init(struct event_trigger_ops *ops,
412 struct event_trigger_data *data)
413{
414 data->ref++;
415 return 0;
416}
417
418/**
419 * event_trigger_free - Generic event_trigger_ops @free implementation
420 * @ops: The trigger ops associated with the trigger
421 * @data: Trigger-specific data
422 *
423 * Common implementation of event trigger de-initialization.
424 *
425 * Usually used directly as the @free method in event trigger
426 * implementations.
427 */
428static void
429event_trigger_free(struct event_trigger_ops *ops,
430 struct event_trigger_data *data)
431{
432 if (WARN_ON_ONCE(data->ref <= 0))
433 return;
434
435 data->ref--;
436 if (!data->ref)
437 trigger_data_free(data);
438}
439
440int trace_event_trigger_enable_disable(struct trace_event_file *file,
441 int trigger_enable)
442{
443 int ret = 0;
444
445 if (trigger_enable) {
446 if (atomic_inc_return(&file->tm_ref) > 1)
447 return ret;
448 set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
449 ret = trace_event_enable_disable(file, 1, 1);
450 } else {
451 if (atomic_dec_return(&file->tm_ref) > 0)
452 return ret;
453 clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
454 ret = trace_event_enable_disable(file, 0, 1);
455 }
456
457 return ret;
458}
459
460/**
461 * clear_event_triggers - Clear all triggers associated with a trace array
462 * @tr: The trace array to clear
463 *
464 * For each trigger, the triggering event has its tm_ref decremented
465 * via trace_event_trigger_enable_disable(), and any associated event
466 * (in the case of enable/disable_event triggers) will have its sm_ref
467 * decremented via free()->trace_event_enable_disable(). That
468 * combination effectively reverses the soft-mode/trigger state added
469 * by trigger registration.
470 *
471 * Must be called with event_mutex held.
472 */
473void
474clear_event_triggers(struct trace_array *tr)
475{
476 struct trace_event_file *file;
477
478 list_for_each_entry(file, &tr->events, list) {
479 struct event_trigger_data *data, *n;
480 list_for_each_entry_safe(data, n, &file->triggers, list) {
481 trace_event_trigger_enable_disable(file, 0);
482 list_del_rcu(&data->list);
483 if (data->ops->free)
484 data->ops->free(data->ops, data);
485 }
486 }
487}
488
489/**
490 * update_cond_flag - Set or reset the TRIGGER_COND bit
491 * @file: The trace_event_file associated with the event
492 *
493 * If an event has triggers and any of those triggers has a filter or
494 * a post_trigger, trigger invocation needs to be deferred until after
495 * the current event has logged its data, and the event should have
496 * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be
497 * cleared.
498 */
499void update_cond_flag(struct trace_event_file *file)
500{
501 struct event_trigger_data *data;
502 bool set_cond = false;
503
504 list_for_each_entry_rcu(data, &file->triggers, list) {
505 if (data->filter || event_command_post_trigger(data->cmd_ops) ||
506 event_command_needs_rec(data->cmd_ops)) {
507 set_cond = true;
508 break;
509 }
510 }
511
512 if (set_cond)
513 set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
514 else
515 clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
516}
517
518/**
519 * register_trigger - Generic event_command @reg implementation
520 * @glob: The raw string used to register the trigger
521 * @ops: The trigger ops associated with the trigger
522 * @data: Trigger-specific data to associate with the trigger
523 * @file: The trace_event_file associated with the event
524 *
525 * Common implementation for event trigger registration.
526 *
527 * Usually used directly as the @reg method in event command
528 * implementations.
529 *
530 * Return: 0 on success, errno otherwise
531 */
532static int register_trigger(char *glob, struct event_trigger_ops *ops,
533 struct event_trigger_data *data,
534 struct trace_event_file *file)
535{
536 struct event_trigger_data *test;
537 int ret = 0;
538
539 list_for_each_entry_rcu(test, &file->triggers, list) {
540 if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) {
541 ret = -EEXIST;
542 goto out;
543 }
544 }
545
546 if (data->ops->init) {
547 ret = data->ops->init(data->ops, data);
548 if (ret < 0)
549 goto out;
550 }
551
552 list_add_rcu(&data->list, &file->triggers);
553 ret++;
554
555 update_cond_flag(file);
556 if (trace_event_trigger_enable_disable(file, 1) < 0) {
557 list_del_rcu(&data->list);
558 update_cond_flag(file);
559 ret--;
560 }
561out:
562 return ret;
563}
564
565/**
566 * unregister_trigger - Generic event_command @unreg implementation
567 * @glob: The raw string used to register the trigger
568 * @ops: The trigger ops associated with the trigger
569 * @test: Trigger-specific data used to find the trigger to remove
570 * @file: The trace_event_file associated with the event
571 *
572 * Common implementation for event trigger unregistration.
573 *
574 * Usually used directly as the @unreg method in event command
575 * implementations.
576 */
577static void unregister_trigger(char *glob, struct event_trigger_ops *ops,
578 struct event_trigger_data *test,
579 struct trace_event_file *file)
580{
581 struct event_trigger_data *data;
582 bool unregistered = false;
583
584 list_for_each_entry_rcu(data, &file->triggers, list) {
585 if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
586 unregistered = true;
587 list_del_rcu(&data->list);
588 trace_event_trigger_enable_disable(file, 0);
589 update_cond_flag(file);
590 break;
591 }
592 }
593
594 if (unregistered && data->ops->free)
595 data->ops->free(data->ops, data);
596}
597
598/**
599 * event_trigger_callback - Generic event_command @func implementation
600 * @cmd_ops: The command ops, used for trigger registration
601 * @file: The trace_event_file associated with the event
602 * @glob: The raw string used to register the trigger
603 * @cmd: The cmd portion of the string used to register the trigger
604 * @param: The params portion of the string used to register the trigger
605 *
606 * Common implementation for event command parsing and trigger
607 * instantiation.
608 *
609 * Usually used directly as the @func method in event command
610 * implementations.
611 *
612 * Return: 0 on success, errno otherwise
613 */
614static int
615event_trigger_callback(struct event_command *cmd_ops,
616 struct trace_event_file *file,
617 char *glob, char *cmd, char *param)
618{
619 struct event_trigger_data *trigger_data;
620 struct event_trigger_ops *trigger_ops;
621 char *trigger = NULL;
622 char *number;
623 int ret;
624
625 /* separate the trigger from the filter (t:n [if filter]) */
626 if (param && isdigit(param[0]))
627 trigger = strsep(¶m, " \t");
628
629 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
630
631 ret = -ENOMEM;
632 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
633 if (!trigger_data)
634 goto out;
635
636 trigger_data->count = -1;
637 trigger_data->ops = trigger_ops;
638 trigger_data->cmd_ops = cmd_ops;
639 trigger_data->private_data = file;
640 INIT_LIST_HEAD(&trigger_data->list);
641 INIT_LIST_HEAD(&trigger_data->named_list);
642
643 if (glob[0] == '!') {
644 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
645 kfree(trigger_data);
646 ret = 0;
647 goto out;
648 }
649
650 if (trigger) {
651 number = strsep(&trigger, ":");
652
653 ret = -EINVAL;
654 if (!strlen(number))
655 goto out_free;
656
657 /*
658 * We use the callback data field (which is a pointer)
659 * as our counter.
660 */
661 ret = kstrtoul(number, 0, &trigger_data->count);
662 if (ret)
663 goto out_free;
664 }
665
666 if (!param) /* if param is non-empty, it's supposed to be a filter */
667 goto out_reg;
668
669 if (!cmd_ops->set_filter)
670 goto out_reg;
671
672 ret = cmd_ops->set_filter(param, trigger_data, file);
673 if (ret < 0)
674 goto out_free;
675
676 out_reg:
677 /* Up the trigger_data count to make sure reg doesn't free it on failure */
678 event_trigger_init(trigger_ops, trigger_data);
679 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
680 /*
681 * The above returns on success the # of functions enabled,
682 * but if it didn't find any functions it returns zero.
683 * Consider no functions a failure too.
684 */
685 if (!ret) {
686 cmd_ops->unreg(glob, trigger_ops, trigger_data, file);
687 ret = -ENOENT;
688 } else if (ret > 0)
689 ret = 0;
690
691 /* Down the counter of trigger_data or free it if not used anymore */
692 event_trigger_free(trigger_ops, trigger_data);
693 out:
694 return ret;
695
696 out_free:
697 if (cmd_ops->set_filter)
698 cmd_ops->set_filter(NULL, trigger_data, NULL);
699 kfree(trigger_data);
700 goto out;
701}
702
703/**
704 * set_trigger_filter - Generic event_command @set_filter implementation
705 * @filter_str: The filter string for the trigger, NULL to remove filter
706 * @trigger_data: Trigger-specific data
707 * @file: The trace_event_file associated with the event
708 *
709 * Common implementation for event command filter parsing and filter
710 * instantiation.
711 *
712 * Usually used directly as the @set_filter method in event command
713 * implementations.
714 *
715 * Also used to remove a filter (if filter_str = NULL).
716 *
717 * Return: 0 on success, errno otherwise
718 */
719int set_trigger_filter(char *filter_str,
720 struct event_trigger_data *trigger_data,
721 struct trace_event_file *file)
722{
723 struct event_trigger_data *data = trigger_data;
724 struct event_filter *filter = NULL, *tmp;
725 int ret = -EINVAL;
726 char *s;
727
728 if (!filter_str) /* clear the current filter */
729 goto assign;
730
731 s = strsep(&filter_str, " \t");
732
733 if (!strlen(s) || strcmp(s, "if") != 0)
734 goto out;
735
736 if (!filter_str)
737 goto out;
738
739 /* The filter is for the 'trigger' event, not the triggered event */
740 ret = create_event_filter(file->tr, file->event_call,
741 filter_str, false, &filter);
742 /*
743 * If create_event_filter() fails, filter still needs to be freed.
744 * Which the calling code will do with data->filter.
745 */
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 tracepoint_synchronize_unregister();
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 /* Up the trigger_data count to make sure nothing frees it on failure */
1422 event_trigger_init(trigger_ops, trigger_data);
1423
1424 if (trigger) {
1425 number = strsep(&trigger, ":");
1426
1427 ret = -EINVAL;
1428 if (!strlen(number))
1429 goto out_free;
1430
1431 /*
1432 * We use the callback data field (which is a pointer)
1433 * as our counter.
1434 */
1435 ret = kstrtoul(number, 0, &trigger_data->count);
1436 if (ret)
1437 goto out_free;
1438 }
1439
1440 if (!param) /* if param is non-empty, it's supposed to be a filter */
1441 goto out_reg;
1442
1443 if (!cmd_ops->set_filter)
1444 goto out_reg;
1445
1446 ret = cmd_ops->set_filter(param, trigger_data, file);
1447 if (ret < 0)
1448 goto out_free;
1449
1450 out_reg:
1451 /* Don't let event modules unload while probe registered */
1452 ret = try_module_get(event_enable_file->event_call->mod);
1453 if (!ret) {
1454 ret = -EBUSY;
1455 goto out_free;
1456 }
1457
1458 ret = trace_event_enable_disable(event_enable_file, 1, 1);
1459 if (ret < 0)
1460 goto out_put;
1461 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1462 /*
1463 * The above returns on success the # of functions enabled,
1464 * but if it didn't find any functions it returns zero.
1465 * Consider no functions a failure too.
1466 */
1467 if (!ret) {
1468 ret = -ENOENT;
1469 goto out_disable;
1470 } else if (ret < 0)
1471 goto out_disable;
1472 /* Just return zero, not the number of enabled functions */
1473 ret = 0;
1474 event_trigger_free(trigger_ops, trigger_data);
1475 out:
1476 return ret;
1477
1478 out_disable:
1479 trace_event_enable_disable(event_enable_file, 0, 1);
1480 out_put:
1481 module_put(event_enable_file->event_call->mod);
1482 out_free:
1483 if (cmd_ops->set_filter)
1484 cmd_ops->set_filter(NULL, trigger_data, NULL);
1485 event_trigger_free(trigger_ops, trigger_data);
1486 kfree(enable_data);
1487 goto out;
1488}
1489
1490int event_enable_register_trigger(char *glob,
1491 struct event_trigger_ops *ops,
1492 struct event_trigger_data *data,
1493 struct trace_event_file *file)
1494{
1495 struct enable_trigger_data *enable_data = data->private_data;
1496 struct enable_trigger_data *test_enable_data;
1497 struct event_trigger_data *test;
1498 int ret = 0;
1499
1500 list_for_each_entry_rcu(test, &file->triggers, list) {
1501 test_enable_data = test->private_data;
1502 if (test_enable_data &&
1503 (test->cmd_ops->trigger_type ==
1504 data->cmd_ops->trigger_type) &&
1505 (test_enable_data->file == enable_data->file)) {
1506 ret = -EEXIST;
1507 goto out;
1508 }
1509 }
1510
1511 if (data->ops->init) {
1512 ret = data->ops->init(data->ops, data);
1513 if (ret < 0)
1514 goto out;
1515 }
1516
1517 list_add_rcu(&data->list, &file->triggers);
1518 ret++;
1519
1520 update_cond_flag(file);
1521 if (trace_event_trigger_enable_disable(file, 1) < 0) {
1522 list_del_rcu(&data->list);
1523 update_cond_flag(file);
1524 ret--;
1525 }
1526out:
1527 return ret;
1528}
1529
1530void event_enable_unregister_trigger(char *glob,
1531 struct event_trigger_ops *ops,
1532 struct event_trigger_data *test,
1533 struct trace_event_file *file)
1534{
1535 struct enable_trigger_data *test_enable_data = test->private_data;
1536 struct enable_trigger_data *enable_data;
1537 struct event_trigger_data *data;
1538 bool unregistered = false;
1539
1540 list_for_each_entry_rcu(data, &file->triggers, list) {
1541 enable_data = data->private_data;
1542 if (enable_data &&
1543 (data->cmd_ops->trigger_type ==
1544 test->cmd_ops->trigger_type) &&
1545 (enable_data->file == test_enable_data->file)) {
1546 unregistered = true;
1547 list_del_rcu(&data->list);
1548 trace_event_trigger_enable_disable(file, 0);
1549 update_cond_flag(file);
1550 break;
1551 }
1552 }
1553
1554 if (unregistered && data->ops->free)
1555 data->ops->free(data->ops, data);
1556}
1557
1558static struct event_trigger_ops *
1559event_enable_get_trigger_ops(char *cmd, char *param)
1560{
1561 struct event_trigger_ops *ops;
1562 bool enable;
1563
1564#ifdef CONFIG_HIST_TRIGGERS
1565 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1566 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1567#else
1568 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1569#endif
1570 if (enable)
1571 ops = param ? &event_enable_count_trigger_ops :
1572 &event_enable_trigger_ops;
1573 else
1574 ops = param ? &event_disable_count_trigger_ops :
1575 &event_disable_trigger_ops;
1576
1577 return ops;
1578}
1579
1580static struct event_command trigger_enable_cmd = {
1581 .name = ENABLE_EVENT_STR,
1582 .trigger_type = ETT_EVENT_ENABLE,
1583 .func = event_enable_trigger_func,
1584 .reg = event_enable_register_trigger,
1585 .unreg = event_enable_unregister_trigger,
1586 .get_trigger_ops = event_enable_get_trigger_ops,
1587 .set_filter = set_trigger_filter,
1588};
1589
1590static struct event_command trigger_disable_cmd = {
1591 .name = DISABLE_EVENT_STR,
1592 .trigger_type = ETT_EVENT_ENABLE,
1593 .func = event_enable_trigger_func,
1594 .reg = event_enable_register_trigger,
1595 .unreg = event_enable_unregister_trigger,
1596 .get_trigger_ops = event_enable_get_trigger_ops,
1597 .set_filter = set_trigger_filter,
1598};
1599
1600static __init void unregister_trigger_enable_disable_cmds(void)
1601{
1602 unregister_event_command(&trigger_enable_cmd);
1603 unregister_event_command(&trigger_disable_cmd);
1604}
1605
1606static __init int register_trigger_enable_disable_cmds(void)
1607{
1608 int ret;
1609
1610 ret = register_event_command(&trigger_enable_cmd);
1611 if (WARN_ON(ret < 0))
1612 return ret;
1613 ret = register_event_command(&trigger_disable_cmd);
1614 if (WARN_ON(ret < 0))
1615 unregister_trigger_enable_disable_cmds();
1616
1617 return ret;
1618}
1619
1620static __init int register_trigger_traceon_traceoff_cmds(void)
1621{
1622 int ret;
1623
1624 ret = register_event_command(&trigger_traceon_cmd);
1625 if (WARN_ON(ret < 0))
1626 return ret;
1627 ret = register_event_command(&trigger_traceoff_cmd);
1628 if (WARN_ON(ret < 0))
1629 unregister_trigger_traceon_traceoff_cmds();
1630
1631 return ret;
1632}
1633
1634__init int register_trigger_cmds(void)
1635{
1636 register_trigger_traceon_traceoff_cmds();
1637 register_trigger_snapshot_cmd();
1638 register_trigger_stacktrace_cmd();
1639 register_trigger_enable_disable_cmds();
1640 register_trigger_hist_enable_disable_cmds();
1641 register_trigger_hist_cmd();
1642
1643 return 0;
1644}
1/*
2 * trace_events_trigger - trace event triggers
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 * Copyright (C) 2013 Tom Zanussi <tom.zanussi@linux.intel.com>
19 */
20
21#include <linux/module.h>
22#include <linux/ctype.h>
23#include <linux/mutex.h>
24#include <linux/slab.h>
25
26#include "trace.h"
27
28static LIST_HEAD(trigger_commands);
29static DEFINE_MUTEX(trigger_cmd_mutex);
30
31void trigger_data_free(struct event_trigger_data *data)
32{
33 if (data->cmd_ops->set_filter)
34 data->cmd_ops->set_filter(NULL, data, NULL);
35
36 synchronize_sched(); /* make sure current triggers exit before free */
37 kfree(data);
38}
39
40/**
41 * event_triggers_call - Call triggers associated with a trace event
42 * @file: The trace_event_file associated with the event
43 * @rec: The trace entry for the event, NULL for unconditional invocation
44 *
45 * For each trigger associated with an event, invoke the trigger
46 * function registered with the associated trigger command. If rec is
47 * non-NULL, it means that the trigger requires further processing and
48 * shouldn't be unconditionally invoked. If rec is non-NULL and the
49 * trigger has a filter associated with it, rec will checked against
50 * the filter and if the record matches the trigger will be invoked.
51 * If the trigger is a 'post_trigger', meaning it shouldn't be invoked
52 * in any case until the current event is written, the trigger
53 * function isn't invoked but the bit associated with the deferred
54 * trigger is set in the return value.
55 *
56 * Returns an enum event_trigger_type value containing a set bit for
57 * any trigger that should be deferred, ETT_NONE if nothing to defer.
58 *
59 * Called from tracepoint handlers (with rcu_read_lock_sched() held).
60 *
61 * Return: an enum event_trigger_type value containing a set bit for
62 * any trigger that should be deferred, ETT_NONE if nothing to defer.
63 */
64enum event_trigger_type
65event_triggers_call(struct trace_event_file *file, void *rec)
66{
67 struct event_trigger_data *data;
68 enum event_trigger_type tt = ETT_NONE;
69 struct event_filter *filter;
70
71 if (list_empty(&file->triggers))
72 return tt;
73
74 list_for_each_entry_rcu(data, &file->triggers, list) {
75 if (data->paused)
76 continue;
77 if (!rec) {
78 data->ops->func(data, rec);
79 continue;
80 }
81 filter = rcu_dereference_sched(data->filter);
82 if (filter && !filter_match_preds(filter, rec))
83 continue;
84 if (event_command_post_trigger(data->cmd_ops)) {
85 tt |= data->cmd_ops->trigger_type;
86 continue;
87 }
88 data->ops->func(data, rec);
89 }
90 return tt;
91}
92EXPORT_SYMBOL_GPL(event_triggers_call);
93
94/**
95 * event_triggers_post_call - Call 'post_triggers' for a trace event
96 * @file: The trace_event_file associated with the event
97 * @tt: enum event_trigger_type containing a set bit for each trigger to invoke
98 * @rec: The trace entry for the event
99 *
100 * For each trigger associated with an event, invoke the trigger
101 * function registered with the associated trigger command, if the
102 * corresponding bit is set in the tt enum passed into this function.
103 * See @event_triggers_call for details on how those bits are set.
104 *
105 * Called from tracepoint handlers (with rcu_read_lock_sched() held).
106 */
107void
108event_triggers_post_call(struct trace_event_file *file,
109 enum event_trigger_type tt,
110 void *rec)
111{
112 struct event_trigger_data *data;
113
114 list_for_each_entry_rcu(data, &file->triggers, list) {
115 if (data->paused)
116 continue;
117 if (data->cmd_ops->trigger_type & tt)
118 data->ops->func(data, rec);
119 }
120}
121EXPORT_SYMBOL_GPL(event_triggers_post_call);
122
123#define SHOW_AVAILABLE_TRIGGERS (void *)(1UL)
124
125static void *trigger_next(struct seq_file *m, void *t, loff_t *pos)
126{
127 struct trace_event_file *event_file = event_file_data(m->private);
128
129 if (t == SHOW_AVAILABLE_TRIGGERS)
130 return NULL;
131
132 return seq_list_next(t, &event_file->triggers, pos);
133}
134
135static void *trigger_start(struct seq_file *m, loff_t *pos)
136{
137 struct trace_event_file *event_file;
138
139 /* ->stop() is called even if ->start() fails */
140 mutex_lock(&event_mutex);
141 event_file = event_file_data(m->private);
142 if (unlikely(!event_file))
143 return ERR_PTR(-ENODEV);
144
145 if (list_empty(&event_file->triggers))
146 return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL;
147
148 return seq_list_start(&event_file->triggers, *pos);
149}
150
151static void trigger_stop(struct seq_file *m, void *t)
152{
153 mutex_unlock(&event_mutex);
154}
155
156static int trigger_show(struct seq_file *m, void *v)
157{
158 struct event_trigger_data *data;
159 struct event_command *p;
160
161 if (v == SHOW_AVAILABLE_TRIGGERS) {
162 seq_puts(m, "# Available triggers:\n");
163 seq_putc(m, '#');
164 mutex_lock(&trigger_cmd_mutex);
165 list_for_each_entry_reverse(p, &trigger_commands, list)
166 seq_printf(m, " %s", p->name);
167 seq_putc(m, '\n');
168 mutex_unlock(&trigger_cmd_mutex);
169 return 0;
170 }
171
172 data = list_entry(v, struct event_trigger_data, list);
173 data->ops->print(m, data->ops, data);
174
175 return 0;
176}
177
178static const struct seq_operations event_triggers_seq_ops = {
179 .start = trigger_start,
180 .next = trigger_next,
181 .stop = trigger_stop,
182 .show = trigger_show,
183};
184
185static int event_trigger_regex_open(struct inode *inode, struct file *file)
186{
187 int ret = 0;
188
189 mutex_lock(&event_mutex);
190
191 if (unlikely(!event_file_data(file))) {
192 mutex_unlock(&event_mutex);
193 return -ENODEV;
194 }
195
196 if ((file->f_mode & FMODE_WRITE) &&
197 (file->f_flags & O_TRUNC)) {
198 struct trace_event_file *event_file;
199 struct event_command *p;
200
201 event_file = event_file_data(file);
202
203 list_for_each_entry(p, &trigger_commands, list) {
204 if (p->unreg_all)
205 p->unreg_all(event_file);
206 }
207 }
208
209 if (file->f_mode & FMODE_READ) {
210 ret = seq_open(file, &event_triggers_seq_ops);
211 if (!ret) {
212 struct seq_file *m = file->private_data;
213 m->private = file;
214 }
215 }
216
217 mutex_unlock(&event_mutex);
218
219 return ret;
220}
221
222static int trigger_process_regex(struct trace_event_file *file, char *buff)
223{
224 char *command, *next = buff;
225 struct event_command *p;
226 int ret = -EINVAL;
227
228 command = strsep(&next, ": \t");
229 command = (command[0] != '!') ? command : command + 1;
230
231 mutex_lock(&trigger_cmd_mutex);
232 list_for_each_entry(p, &trigger_commands, list) {
233 if (strcmp(p->name, command) == 0) {
234 ret = p->func(p, file, buff, command, next);
235 goto out_unlock;
236 }
237 }
238 out_unlock:
239 mutex_unlock(&trigger_cmd_mutex);
240
241 return ret;
242}
243
244static ssize_t event_trigger_regex_write(struct file *file,
245 const char __user *ubuf,
246 size_t cnt, loff_t *ppos)
247{
248 struct trace_event_file *event_file;
249 ssize_t ret;
250 char *buf;
251
252 if (!cnt)
253 return 0;
254
255 if (cnt >= PAGE_SIZE)
256 return -EINVAL;
257
258 buf = memdup_user_nul(ubuf, cnt);
259 if (IS_ERR(buf))
260 return PTR_ERR(buf);
261
262 strim(buf);
263
264 mutex_lock(&event_mutex);
265 event_file = event_file_data(file);
266 if (unlikely(!event_file)) {
267 mutex_unlock(&event_mutex);
268 kfree(buf);
269 return -ENODEV;
270 }
271 ret = trigger_process_regex(event_file, buf);
272 mutex_unlock(&event_mutex);
273
274 kfree(buf);
275 if (ret < 0)
276 goto out;
277
278 *ppos += cnt;
279 ret = cnt;
280 out:
281 return ret;
282}
283
284static int event_trigger_regex_release(struct inode *inode, struct file *file)
285{
286 mutex_lock(&event_mutex);
287
288 if (file->f_mode & FMODE_READ)
289 seq_release(inode, file);
290
291 mutex_unlock(&event_mutex);
292
293 return 0;
294}
295
296static ssize_t
297event_trigger_write(struct file *filp, const char __user *ubuf,
298 size_t cnt, loff_t *ppos)
299{
300 return event_trigger_regex_write(filp, ubuf, cnt, ppos);
301}
302
303static int
304event_trigger_open(struct inode *inode, struct file *filp)
305{
306 return event_trigger_regex_open(inode, filp);
307}
308
309static int
310event_trigger_release(struct inode *inode, struct file *file)
311{
312 return event_trigger_regex_release(inode, file);
313}
314
315const struct file_operations event_trigger_fops = {
316 .open = event_trigger_open,
317 .read = seq_read,
318 .write = event_trigger_write,
319 .llseek = tracing_lseek,
320 .release = event_trigger_release,
321};
322
323/*
324 * Currently we only register event commands from __init, so mark this
325 * __init too.
326 */
327__init int register_event_command(struct event_command *cmd)
328{
329 struct event_command *p;
330 int ret = 0;
331
332 mutex_lock(&trigger_cmd_mutex);
333 list_for_each_entry(p, &trigger_commands, list) {
334 if (strcmp(cmd->name, p->name) == 0) {
335 ret = -EBUSY;
336 goto out_unlock;
337 }
338 }
339 list_add(&cmd->list, &trigger_commands);
340 out_unlock:
341 mutex_unlock(&trigger_cmd_mutex);
342
343 return ret;
344}
345
346/*
347 * Currently we only unregister event commands from __init, so mark
348 * this __init too.
349 */
350__init int unregister_event_command(struct event_command *cmd)
351{
352 struct event_command *p, *n;
353 int ret = -ENODEV;
354
355 mutex_lock(&trigger_cmd_mutex);
356 list_for_each_entry_safe(p, n, &trigger_commands, list) {
357 if (strcmp(cmd->name, p->name) == 0) {
358 ret = 0;
359 list_del_init(&p->list);
360 goto out_unlock;
361 }
362 }
363 out_unlock:
364 mutex_unlock(&trigger_cmd_mutex);
365
366 return ret;
367}
368
369/**
370 * event_trigger_print - Generic event_trigger_ops @print implementation
371 * @name: The name of the event trigger
372 * @m: The seq_file being printed to
373 * @data: Trigger-specific data
374 * @filter_str: filter_str to print, if present
375 *
376 * Common implementation for event triggers to print themselves.
377 *
378 * Usually wrapped by a function that simply sets the @name of the
379 * trigger command and then invokes this.
380 *
381 * Return: 0 on success, errno otherwise
382 */
383static int
384event_trigger_print(const char *name, struct seq_file *m,
385 void *data, char *filter_str)
386{
387 long count = (long)data;
388
389 seq_puts(m, name);
390
391 if (count == -1)
392 seq_puts(m, ":unlimited");
393 else
394 seq_printf(m, ":count=%ld", count);
395
396 if (filter_str)
397 seq_printf(m, " if %s\n", filter_str);
398 else
399 seq_putc(m, '\n');
400
401 return 0;
402}
403
404/**
405 * event_trigger_init - Generic event_trigger_ops @init implementation
406 * @ops: The trigger ops associated with the trigger
407 * @data: Trigger-specific data
408 *
409 * Common implementation of event trigger initialization.
410 *
411 * Usually used directly as the @init method in event trigger
412 * implementations.
413 *
414 * Return: 0 on success, errno otherwise
415 */
416int event_trigger_init(struct event_trigger_ops *ops,
417 struct event_trigger_data *data)
418{
419 data->ref++;
420 return 0;
421}
422
423/**
424 * event_trigger_free - Generic event_trigger_ops @free implementation
425 * @ops: The trigger ops associated with the trigger
426 * @data: Trigger-specific data
427 *
428 * Common implementation of event trigger de-initialization.
429 *
430 * Usually used directly as the @free method in event trigger
431 * implementations.
432 */
433static void
434event_trigger_free(struct event_trigger_ops *ops,
435 struct event_trigger_data *data)
436{
437 if (WARN_ON_ONCE(data->ref <= 0))
438 return;
439
440 data->ref--;
441 if (!data->ref)
442 trigger_data_free(data);
443}
444
445int trace_event_trigger_enable_disable(struct trace_event_file *file,
446 int trigger_enable)
447{
448 int ret = 0;
449
450 if (trigger_enable) {
451 if (atomic_inc_return(&file->tm_ref) > 1)
452 return ret;
453 set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
454 ret = trace_event_enable_disable(file, 1, 1);
455 } else {
456 if (atomic_dec_return(&file->tm_ref) > 0)
457 return ret;
458 clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
459 ret = trace_event_enable_disable(file, 0, 1);
460 }
461
462 return ret;
463}
464
465/**
466 * clear_event_triggers - Clear all triggers associated with a trace array
467 * @tr: The trace array to clear
468 *
469 * For each trigger, the triggering event has its tm_ref decremented
470 * via trace_event_trigger_enable_disable(), and any associated event
471 * (in the case of enable/disable_event triggers) will have its sm_ref
472 * decremented via free()->trace_event_enable_disable(). That
473 * combination effectively reverses the soft-mode/trigger state added
474 * by trigger registration.
475 *
476 * Must be called with event_mutex held.
477 */
478void
479clear_event_triggers(struct trace_array *tr)
480{
481 struct trace_event_file *file;
482
483 list_for_each_entry(file, &tr->events, list) {
484 struct event_trigger_data *data;
485 list_for_each_entry_rcu(data, &file->triggers, list) {
486 trace_event_trigger_enable_disable(file, 0);
487 if (data->ops->free)
488 data->ops->free(data->ops, data);
489 }
490 }
491}
492
493/**
494 * update_cond_flag - Set or reset the TRIGGER_COND bit
495 * @file: The trace_event_file associated with the event
496 *
497 * If an event has triggers and any of those triggers has a filter or
498 * a post_trigger, trigger invocation needs to be deferred until after
499 * the current event has logged its data, and the event should have
500 * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be
501 * cleared.
502 */
503void update_cond_flag(struct trace_event_file *file)
504{
505 struct event_trigger_data *data;
506 bool set_cond = false;
507
508 list_for_each_entry_rcu(data, &file->triggers, list) {
509 if (data->filter || event_command_post_trigger(data->cmd_ops) ||
510 event_command_needs_rec(data->cmd_ops)) {
511 set_cond = true;
512 break;
513 }
514 }
515
516 if (set_cond)
517 set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
518 else
519 clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
520}
521
522/**
523 * register_trigger - Generic event_command @reg implementation
524 * @glob: The raw string used to register the trigger
525 * @ops: The trigger ops associated with the trigger
526 * @data: Trigger-specific data to associate with the trigger
527 * @file: The trace_event_file associated with the event
528 *
529 * Common implementation for event trigger registration.
530 *
531 * Usually used directly as the @reg method in event command
532 * implementations.
533 *
534 * Return: 0 on success, errno otherwise
535 */
536static int register_trigger(char *glob, struct event_trigger_ops *ops,
537 struct event_trigger_data *data,
538 struct trace_event_file *file)
539{
540 struct event_trigger_data *test;
541 int ret = 0;
542
543 list_for_each_entry_rcu(test, &file->triggers, list) {
544 if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) {
545 ret = -EEXIST;
546 goto out;
547 }
548 }
549
550 if (data->ops->init) {
551 ret = data->ops->init(data->ops, data);
552 if (ret < 0)
553 goto out;
554 }
555
556 list_add_rcu(&data->list, &file->triggers);
557 ret++;
558
559 update_cond_flag(file);
560 if (trace_event_trigger_enable_disable(file, 1) < 0) {
561 list_del_rcu(&data->list);
562 update_cond_flag(file);
563 ret--;
564 }
565out:
566 return ret;
567}
568
569/**
570 * unregister_trigger - Generic event_command @unreg implementation
571 * @glob: The raw string used to register the trigger
572 * @ops: The trigger ops associated with the trigger
573 * @test: Trigger-specific data used to find the trigger to remove
574 * @file: The trace_event_file associated with the event
575 *
576 * Common implementation for event trigger unregistration.
577 *
578 * Usually used directly as the @unreg method in event command
579 * implementations.
580 */
581void unregister_trigger(char *glob, struct event_trigger_ops *ops,
582 struct event_trigger_data *test,
583 struct trace_event_file *file)
584{
585 struct event_trigger_data *data;
586 bool unregistered = false;
587
588 list_for_each_entry_rcu(data, &file->triggers, list) {
589 if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
590 unregistered = true;
591 list_del_rcu(&data->list);
592 trace_event_trigger_enable_disable(file, 0);
593 update_cond_flag(file);
594 break;
595 }
596 }
597
598 if (unregistered && data->ops->free)
599 data->ops->free(data->ops, data);
600}
601
602/**
603 * event_trigger_callback - Generic event_command @func implementation
604 * @cmd_ops: The command ops, used for trigger registration
605 * @file: The trace_event_file associated with the event
606 * @glob: The raw string used to register the trigger
607 * @cmd: The cmd portion of the string used to register the trigger
608 * @param: The params portion of the string used to register the trigger
609 *
610 * Common implementation for event command parsing and trigger
611 * instantiation.
612 *
613 * Usually used directly as the @func method in event command
614 * implementations.
615 *
616 * Return: 0 on success, errno otherwise
617 */
618static int
619event_trigger_callback(struct event_command *cmd_ops,
620 struct trace_event_file *file,
621 char *glob, char *cmd, char *param)
622{
623 struct event_trigger_data *trigger_data;
624 struct event_trigger_ops *trigger_ops;
625 char *trigger = NULL;
626 char *number;
627 int ret;
628
629 /* separate the trigger from the filter (t:n [if filter]) */
630 if (param && isdigit(param[0]))
631 trigger = strsep(¶m, " \t");
632
633 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
634
635 ret = -ENOMEM;
636 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
637 if (!trigger_data)
638 goto out;
639
640 trigger_data->count = -1;
641 trigger_data->ops = trigger_ops;
642 trigger_data->cmd_ops = cmd_ops;
643 INIT_LIST_HEAD(&trigger_data->list);
644 INIT_LIST_HEAD(&trigger_data->named_list);
645
646 if (glob[0] == '!') {
647 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
648 kfree(trigger_data);
649 ret = 0;
650 goto out;
651 }
652
653 if (trigger) {
654 number = strsep(&trigger, ":");
655
656 ret = -EINVAL;
657 if (!strlen(number))
658 goto out_free;
659
660 /*
661 * We use the callback data field (which is a pointer)
662 * as our counter.
663 */
664 ret = kstrtoul(number, 0, &trigger_data->count);
665 if (ret)
666 goto out_free;
667 }
668
669 if (!param) /* if param is non-empty, it's supposed to be a filter */
670 goto out_reg;
671
672 if (!cmd_ops->set_filter)
673 goto out_reg;
674
675 ret = cmd_ops->set_filter(param, trigger_data, file);
676 if (ret < 0)
677 goto out_free;
678
679 out_reg:
680 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
681 /*
682 * The above returns on success the # of functions enabled,
683 * but if it didn't find any functions it returns zero.
684 * Consider no functions a failure too.
685 */
686 if (!ret) {
687 ret = -ENOENT;
688 goto out_free;
689 } else if (ret < 0)
690 goto out_free;
691 ret = 0;
692 out:
693 return ret;
694
695 out_free:
696 if (cmd_ops->set_filter)
697 cmd_ops->set_filter(NULL, trigger_data, NULL);
698 kfree(trigger_data);
699 goto out;
700}
701
702/**
703 * set_trigger_filter - Generic event_command @set_filter implementation
704 * @filter_str: The filter string for the trigger, NULL to remove filter
705 * @trigger_data: Trigger-specific data
706 * @file: The trace_event_file associated with the event
707 *
708 * Common implementation for event command filter parsing and filter
709 * instantiation.
710 *
711 * Usually used directly as the @set_filter method in event command
712 * implementations.
713 *
714 * Also used to remove a filter (if filter_str = NULL).
715 *
716 * Return: 0 on success, errno otherwise
717 */
718int set_trigger_filter(char *filter_str,
719 struct event_trigger_data *trigger_data,
720 struct trace_event_file *file)
721{
722 struct event_trigger_data *data = trigger_data;
723 struct event_filter *filter = NULL, *tmp;
724 int ret = -EINVAL;
725 char *s;
726
727 if (!filter_str) /* clear the current filter */
728 goto assign;
729
730 s = strsep(&filter_str, " \t");
731
732 if (!strlen(s) || strcmp(s, "if") != 0)
733 goto out;
734
735 if (!filter_str)
736 goto out;
737
738 /* The filter is for the 'trigger' event, not the triggered event */
739 ret = create_event_filter(file->event_call, filter_str, false, &filter);
740 if (ret)
741 goto out;
742 assign:
743 tmp = rcu_access_pointer(data->filter);
744
745 rcu_assign_pointer(data->filter, filter);
746
747 if (tmp) {
748 /* Make sure the call is done with the filter */
749 synchronize_sched();
750 free_event_filter(tmp);
751 }
752
753 kfree(data->filter_str);
754 data->filter_str = NULL;
755
756 if (filter_str) {
757 data->filter_str = kstrdup(filter_str, GFP_KERNEL);
758 if (!data->filter_str) {
759 free_event_filter(rcu_access_pointer(data->filter));
760 data->filter = NULL;
761 ret = -ENOMEM;
762 }
763 }
764 out:
765 return ret;
766}
767
768static LIST_HEAD(named_triggers);
769
770/**
771 * find_named_trigger - Find the common named trigger associated with @name
772 * @name: The name of the set of named triggers to find the common data for
773 *
774 * Named triggers are sets of triggers that share a common set of
775 * trigger data. The first named trigger registered with a given name
776 * owns the common trigger data that the others subsequently
777 * registered with the same name will reference. This function
778 * returns the common trigger data associated with that first
779 * registered instance.
780 *
781 * Return: the common trigger data for the given named trigger on
782 * success, NULL otherwise.
783 */
784struct event_trigger_data *find_named_trigger(const char *name)
785{
786 struct event_trigger_data *data;
787
788 if (!name)
789 return NULL;
790
791 list_for_each_entry(data, &named_triggers, named_list) {
792 if (data->named_data)
793 continue;
794 if (strcmp(data->name, name) == 0)
795 return data;
796 }
797
798 return NULL;
799}
800
801/**
802 * is_named_trigger - determine if a given trigger is a named trigger
803 * @test: The trigger data to test
804 *
805 * Return: true if 'test' is a named trigger, false otherwise.
806 */
807bool is_named_trigger(struct event_trigger_data *test)
808{
809 struct event_trigger_data *data;
810
811 list_for_each_entry(data, &named_triggers, named_list) {
812 if (test == data)
813 return true;
814 }
815
816 return false;
817}
818
819/**
820 * save_named_trigger - save the trigger in the named trigger list
821 * @name: The name of the named trigger set
822 * @data: The trigger data to save
823 *
824 * Return: 0 if successful, negative error otherwise.
825 */
826int save_named_trigger(const char *name, struct event_trigger_data *data)
827{
828 data->name = kstrdup(name, GFP_KERNEL);
829 if (!data->name)
830 return -ENOMEM;
831
832 list_add(&data->named_list, &named_triggers);
833
834 return 0;
835}
836
837/**
838 * del_named_trigger - delete a trigger from the named trigger list
839 * @data: The trigger data to delete
840 */
841void del_named_trigger(struct event_trigger_data *data)
842{
843 kfree(data->name);
844 data->name = NULL;
845
846 list_del(&data->named_list);
847}
848
849static void __pause_named_trigger(struct event_trigger_data *data, bool pause)
850{
851 struct event_trigger_data *test;
852
853 list_for_each_entry(test, &named_triggers, named_list) {
854 if (strcmp(test->name, data->name) == 0) {
855 if (pause) {
856 test->paused_tmp = test->paused;
857 test->paused = true;
858 } else {
859 test->paused = test->paused_tmp;
860 }
861 }
862 }
863}
864
865/**
866 * pause_named_trigger - Pause all named triggers with the same name
867 * @data: The trigger data of a named trigger to pause
868 *
869 * Pauses a named trigger along with all other triggers having the
870 * same name. Because named triggers share a common set of data,
871 * pausing only one is meaningless, so pausing one named trigger needs
872 * to pause all triggers with the same name.
873 */
874void pause_named_trigger(struct event_trigger_data *data)
875{
876 __pause_named_trigger(data, true);
877}
878
879/**
880 * unpause_named_trigger - Un-pause all named triggers with the same name
881 * @data: The trigger data of a named trigger to unpause
882 *
883 * Un-pauses a named trigger along with all other triggers having the
884 * same name. Because named triggers share a common set of data,
885 * unpausing only one is meaningless, so unpausing one named trigger
886 * needs to unpause all triggers with the same name.
887 */
888void unpause_named_trigger(struct event_trigger_data *data)
889{
890 __pause_named_trigger(data, false);
891}
892
893/**
894 * set_named_trigger_data - Associate common named trigger data
895 * @data: The trigger data of a named trigger to unpause
896 *
897 * Named triggers are sets of triggers that share a common set of
898 * trigger data. The first named trigger registered with a given name
899 * owns the common trigger data that the others subsequently
900 * registered with the same name will reference. This function
901 * associates the common trigger data from the first trigger with the
902 * given trigger.
903 */
904void set_named_trigger_data(struct event_trigger_data *data,
905 struct event_trigger_data *named_data)
906{
907 data->named_data = named_data;
908}
909
910static void
911traceon_trigger(struct event_trigger_data *data, void *rec)
912{
913 if (tracing_is_on())
914 return;
915
916 tracing_on();
917}
918
919static void
920traceon_count_trigger(struct event_trigger_data *data, void *rec)
921{
922 if (tracing_is_on())
923 return;
924
925 if (!data->count)
926 return;
927
928 if (data->count != -1)
929 (data->count)--;
930
931 tracing_on();
932}
933
934static void
935traceoff_trigger(struct event_trigger_data *data, void *rec)
936{
937 if (!tracing_is_on())
938 return;
939
940 tracing_off();
941}
942
943static void
944traceoff_count_trigger(struct event_trigger_data *data, void *rec)
945{
946 if (!tracing_is_on())
947 return;
948
949 if (!data->count)
950 return;
951
952 if (data->count != -1)
953 (data->count)--;
954
955 tracing_off();
956}
957
958static int
959traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
960 struct event_trigger_data *data)
961{
962 return event_trigger_print("traceon", m, (void *)data->count,
963 data->filter_str);
964}
965
966static int
967traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
968 struct event_trigger_data *data)
969{
970 return event_trigger_print("traceoff", m, (void *)data->count,
971 data->filter_str);
972}
973
974static struct event_trigger_ops traceon_trigger_ops = {
975 .func = traceon_trigger,
976 .print = traceon_trigger_print,
977 .init = event_trigger_init,
978 .free = event_trigger_free,
979};
980
981static struct event_trigger_ops traceon_count_trigger_ops = {
982 .func = traceon_count_trigger,
983 .print = traceon_trigger_print,
984 .init = event_trigger_init,
985 .free = event_trigger_free,
986};
987
988static struct event_trigger_ops traceoff_trigger_ops = {
989 .func = traceoff_trigger,
990 .print = traceoff_trigger_print,
991 .init = event_trigger_init,
992 .free = event_trigger_free,
993};
994
995static struct event_trigger_ops traceoff_count_trigger_ops = {
996 .func = traceoff_count_trigger,
997 .print = traceoff_trigger_print,
998 .init = event_trigger_init,
999 .free = event_trigger_free,
1000};
1001
1002static struct event_trigger_ops *
1003onoff_get_trigger_ops(char *cmd, char *param)
1004{
1005 struct event_trigger_ops *ops;
1006
1007 /* we register both traceon and traceoff to this callback */
1008 if (strcmp(cmd, "traceon") == 0)
1009 ops = param ? &traceon_count_trigger_ops :
1010 &traceon_trigger_ops;
1011 else
1012 ops = param ? &traceoff_count_trigger_ops :
1013 &traceoff_trigger_ops;
1014
1015 return ops;
1016}
1017
1018static struct event_command trigger_traceon_cmd = {
1019 .name = "traceon",
1020 .trigger_type = ETT_TRACE_ONOFF,
1021 .func = event_trigger_callback,
1022 .reg = register_trigger,
1023 .unreg = unregister_trigger,
1024 .get_trigger_ops = onoff_get_trigger_ops,
1025 .set_filter = set_trigger_filter,
1026};
1027
1028static struct event_command trigger_traceoff_cmd = {
1029 .name = "traceoff",
1030 .trigger_type = ETT_TRACE_ONOFF,
1031 .flags = EVENT_CMD_FL_POST_TRIGGER,
1032 .func = event_trigger_callback,
1033 .reg = register_trigger,
1034 .unreg = unregister_trigger,
1035 .get_trigger_ops = onoff_get_trigger_ops,
1036 .set_filter = set_trigger_filter,
1037};
1038
1039#ifdef CONFIG_TRACER_SNAPSHOT
1040static void
1041snapshot_trigger(struct event_trigger_data *data, void *rec)
1042{
1043 tracing_snapshot();
1044}
1045
1046static void
1047snapshot_count_trigger(struct event_trigger_data *data, void *rec)
1048{
1049 if (!data->count)
1050 return;
1051
1052 if (data->count != -1)
1053 (data->count)--;
1054
1055 snapshot_trigger(data, rec);
1056}
1057
1058static int
1059register_snapshot_trigger(char *glob, struct event_trigger_ops *ops,
1060 struct event_trigger_data *data,
1061 struct trace_event_file *file)
1062{
1063 int ret = register_trigger(glob, ops, data, file);
1064
1065 if (ret > 0 && tracing_alloc_snapshot() != 0) {
1066 unregister_trigger(glob, ops, data, file);
1067 ret = 0;
1068 }
1069
1070 return ret;
1071}
1072
1073static int
1074snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1075 struct event_trigger_data *data)
1076{
1077 return event_trigger_print("snapshot", m, (void *)data->count,
1078 data->filter_str);
1079}
1080
1081static struct event_trigger_ops snapshot_trigger_ops = {
1082 .func = snapshot_trigger,
1083 .print = snapshot_trigger_print,
1084 .init = event_trigger_init,
1085 .free = event_trigger_free,
1086};
1087
1088static struct event_trigger_ops snapshot_count_trigger_ops = {
1089 .func = snapshot_count_trigger,
1090 .print = snapshot_trigger_print,
1091 .init = event_trigger_init,
1092 .free = event_trigger_free,
1093};
1094
1095static struct event_trigger_ops *
1096snapshot_get_trigger_ops(char *cmd, char *param)
1097{
1098 return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
1099}
1100
1101static struct event_command trigger_snapshot_cmd = {
1102 .name = "snapshot",
1103 .trigger_type = ETT_SNAPSHOT,
1104 .func = event_trigger_callback,
1105 .reg = register_snapshot_trigger,
1106 .unreg = unregister_trigger,
1107 .get_trigger_ops = snapshot_get_trigger_ops,
1108 .set_filter = set_trigger_filter,
1109};
1110
1111static __init int register_trigger_snapshot_cmd(void)
1112{
1113 int ret;
1114
1115 ret = register_event_command(&trigger_snapshot_cmd);
1116 WARN_ON(ret < 0);
1117
1118 return ret;
1119}
1120#else
1121static __init int register_trigger_snapshot_cmd(void) { return 0; }
1122#endif /* CONFIG_TRACER_SNAPSHOT */
1123
1124#ifdef CONFIG_STACKTRACE
1125/*
1126 * Skip 3:
1127 * stacktrace_trigger()
1128 * event_triggers_post_call()
1129 * trace_event_raw_event_xxx()
1130 */
1131#define STACK_SKIP 3
1132
1133static void
1134stacktrace_trigger(struct event_trigger_data *data, void *rec)
1135{
1136 trace_dump_stack(STACK_SKIP);
1137}
1138
1139static void
1140stacktrace_count_trigger(struct event_trigger_data *data, void *rec)
1141{
1142 if (!data->count)
1143 return;
1144
1145 if (data->count != -1)
1146 (data->count)--;
1147
1148 stacktrace_trigger(data, rec);
1149}
1150
1151static int
1152stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1153 struct event_trigger_data *data)
1154{
1155 return event_trigger_print("stacktrace", m, (void *)data->count,
1156 data->filter_str);
1157}
1158
1159static struct event_trigger_ops stacktrace_trigger_ops = {
1160 .func = stacktrace_trigger,
1161 .print = stacktrace_trigger_print,
1162 .init = event_trigger_init,
1163 .free = event_trigger_free,
1164};
1165
1166static struct event_trigger_ops stacktrace_count_trigger_ops = {
1167 .func = stacktrace_count_trigger,
1168 .print = stacktrace_trigger_print,
1169 .init = event_trigger_init,
1170 .free = event_trigger_free,
1171};
1172
1173static struct event_trigger_ops *
1174stacktrace_get_trigger_ops(char *cmd, char *param)
1175{
1176 return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
1177}
1178
1179static struct event_command trigger_stacktrace_cmd = {
1180 .name = "stacktrace",
1181 .trigger_type = ETT_STACKTRACE,
1182 .flags = EVENT_CMD_FL_POST_TRIGGER,
1183 .func = event_trigger_callback,
1184 .reg = register_trigger,
1185 .unreg = unregister_trigger,
1186 .get_trigger_ops = stacktrace_get_trigger_ops,
1187 .set_filter = set_trigger_filter,
1188};
1189
1190static __init int register_trigger_stacktrace_cmd(void)
1191{
1192 int ret;
1193
1194 ret = register_event_command(&trigger_stacktrace_cmd);
1195 WARN_ON(ret < 0);
1196
1197 return ret;
1198}
1199#else
1200static __init int register_trigger_stacktrace_cmd(void) { return 0; }
1201#endif /* CONFIG_STACKTRACE */
1202
1203static __init void unregister_trigger_traceon_traceoff_cmds(void)
1204{
1205 unregister_event_command(&trigger_traceon_cmd);
1206 unregister_event_command(&trigger_traceoff_cmd);
1207}
1208
1209static void
1210event_enable_trigger(struct event_trigger_data *data, void *rec)
1211{
1212 struct enable_trigger_data *enable_data = data->private_data;
1213
1214 if (enable_data->enable)
1215 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1216 else
1217 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1218}
1219
1220static void
1221event_enable_count_trigger(struct event_trigger_data *data, void *rec)
1222{
1223 struct enable_trigger_data *enable_data = data->private_data;
1224
1225 if (!data->count)
1226 return;
1227
1228 /* Skip if the event is in a state we want to switch to */
1229 if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
1230 return;
1231
1232 if (data->count != -1)
1233 (data->count)--;
1234
1235 event_enable_trigger(data, rec);
1236}
1237
1238int event_enable_trigger_print(struct seq_file *m,
1239 struct event_trigger_ops *ops,
1240 struct event_trigger_data *data)
1241{
1242 struct enable_trigger_data *enable_data = data->private_data;
1243
1244 seq_printf(m, "%s:%s:%s",
1245 enable_data->hist ?
1246 (enable_data->enable ? ENABLE_HIST_STR : DISABLE_HIST_STR) :
1247 (enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR),
1248 enable_data->file->event_call->class->system,
1249 trace_event_name(enable_data->file->event_call));
1250
1251 if (data->count == -1)
1252 seq_puts(m, ":unlimited");
1253 else
1254 seq_printf(m, ":count=%ld", data->count);
1255
1256 if (data->filter_str)
1257 seq_printf(m, " if %s\n", data->filter_str);
1258 else
1259 seq_putc(m, '\n');
1260
1261 return 0;
1262}
1263
1264void event_enable_trigger_free(struct event_trigger_ops *ops,
1265 struct event_trigger_data *data)
1266{
1267 struct enable_trigger_data *enable_data = data->private_data;
1268
1269 if (WARN_ON_ONCE(data->ref <= 0))
1270 return;
1271
1272 data->ref--;
1273 if (!data->ref) {
1274 /* Remove the SOFT_MODE flag */
1275 trace_event_enable_disable(enable_data->file, 0, 1);
1276 module_put(enable_data->file->event_call->mod);
1277 trigger_data_free(data);
1278 kfree(enable_data);
1279 }
1280}
1281
1282static struct event_trigger_ops event_enable_trigger_ops = {
1283 .func = event_enable_trigger,
1284 .print = event_enable_trigger_print,
1285 .init = event_trigger_init,
1286 .free = event_enable_trigger_free,
1287};
1288
1289static struct event_trigger_ops event_enable_count_trigger_ops = {
1290 .func = event_enable_count_trigger,
1291 .print = event_enable_trigger_print,
1292 .init = event_trigger_init,
1293 .free = event_enable_trigger_free,
1294};
1295
1296static struct event_trigger_ops event_disable_trigger_ops = {
1297 .func = event_enable_trigger,
1298 .print = event_enable_trigger_print,
1299 .init = event_trigger_init,
1300 .free = event_enable_trigger_free,
1301};
1302
1303static struct event_trigger_ops event_disable_count_trigger_ops = {
1304 .func = event_enable_count_trigger,
1305 .print = event_enable_trigger_print,
1306 .init = event_trigger_init,
1307 .free = event_enable_trigger_free,
1308};
1309
1310int event_enable_trigger_func(struct event_command *cmd_ops,
1311 struct trace_event_file *file,
1312 char *glob, char *cmd, char *param)
1313{
1314 struct trace_event_file *event_enable_file;
1315 struct enable_trigger_data *enable_data;
1316 struct event_trigger_data *trigger_data;
1317 struct event_trigger_ops *trigger_ops;
1318 struct trace_array *tr = file->tr;
1319 const char *system;
1320 const char *event;
1321 bool hist = false;
1322 char *trigger;
1323 char *number;
1324 bool enable;
1325 int ret;
1326
1327 if (!param)
1328 return -EINVAL;
1329
1330 /* separate the trigger from the filter (s:e:n [if filter]) */
1331 trigger = strsep(¶m, " \t");
1332 if (!trigger)
1333 return -EINVAL;
1334
1335 system = strsep(&trigger, ":");
1336 if (!trigger)
1337 return -EINVAL;
1338
1339 event = strsep(&trigger, ":");
1340
1341 ret = -EINVAL;
1342 event_enable_file = find_event_file(tr, system, event);
1343 if (!event_enable_file)
1344 goto out;
1345
1346#ifdef CONFIG_HIST_TRIGGERS
1347 hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) ||
1348 (strcmp(cmd, DISABLE_HIST_STR) == 0));
1349
1350 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1351 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1352#else
1353 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1354#endif
1355 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
1356
1357 ret = -ENOMEM;
1358 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
1359 if (!trigger_data)
1360 goto out;
1361
1362 enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
1363 if (!enable_data) {
1364 kfree(trigger_data);
1365 goto out;
1366 }
1367
1368 trigger_data->count = -1;
1369 trigger_data->ops = trigger_ops;
1370 trigger_data->cmd_ops = cmd_ops;
1371 INIT_LIST_HEAD(&trigger_data->list);
1372 RCU_INIT_POINTER(trigger_data->filter, NULL);
1373
1374 enable_data->hist = hist;
1375 enable_data->enable = enable;
1376 enable_data->file = event_enable_file;
1377 trigger_data->private_data = enable_data;
1378
1379 if (glob[0] == '!') {
1380 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
1381 kfree(trigger_data);
1382 kfree(enable_data);
1383 ret = 0;
1384 goto out;
1385 }
1386
1387 if (trigger) {
1388 number = strsep(&trigger, ":");
1389
1390 ret = -EINVAL;
1391 if (!strlen(number))
1392 goto out_free;
1393
1394 /*
1395 * We use the callback data field (which is a pointer)
1396 * as our counter.
1397 */
1398 ret = kstrtoul(number, 0, &trigger_data->count);
1399 if (ret)
1400 goto out_free;
1401 }
1402
1403 if (!param) /* if param is non-empty, it's supposed to be a filter */
1404 goto out_reg;
1405
1406 if (!cmd_ops->set_filter)
1407 goto out_reg;
1408
1409 ret = cmd_ops->set_filter(param, trigger_data, file);
1410 if (ret < 0)
1411 goto out_free;
1412
1413 out_reg:
1414 /* Don't let event modules unload while probe registered */
1415 ret = try_module_get(event_enable_file->event_call->mod);
1416 if (!ret) {
1417 ret = -EBUSY;
1418 goto out_free;
1419 }
1420
1421 ret = trace_event_enable_disable(event_enable_file, 1, 1);
1422 if (ret < 0)
1423 goto out_put;
1424 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1425 /*
1426 * The above returns on success the # of functions enabled,
1427 * but if it didn't find any functions it returns zero.
1428 * Consider no functions a failure too.
1429 */
1430 if (!ret) {
1431 ret = -ENOENT;
1432 goto out_disable;
1433 } else if (ret < 0)
1434 goto out_disable;
1435 /* Just return zero, not the number of enabled functions */
1436 ret = 0;
1437 out:
1438 return ret;
1439
1440 out_disable:
1441 trace_event_enable_disable(event_enable_file, 0, 1);
1442 out_put:
1443 module_put(event_enable_file->event_call->mod);
1444 out_free:
1445 if (cmd_ops->set_filter)
1446 cmd_ops->set_filter(NULL, trigger_data, NULL);
1447 kfree(trigger_data);
1448 kfree(enable_data);
1449 goto out;
1450}
1451
1452int event_enable_register_trigger(char *glob,
1453 struct event_trigger_ops *ops,
1454 struct event_trigger_data *data,
1455 struct trace_event_file *file)
1456{
1457 struct enable_trigger_data *enable_data = data->private_data;
1458 struct enable_trigger_data *test_enable_data;
1459 struct event_trigger_data *test;
1460 int ret = 0;
1461
1462 list_for_each_entry_rcu(test, &file->triggers, list) {
1463 test_enable_data = test->private_data;
1464 if (test_enable_data &&
1465 (test->cmd_ops->trigger_type ==
1466 data->cmd_ops->trigger_type) &&
1467 (test_enable_data->file == enable_data->file)) {
1468 ret = -EEXIST;
1469 goto out;
1470 }
1471 }
1472
1473 if (data->ops->init) {
1474 ret = data->ops->init(data->ops, data);
1475 if (ret < 0)
1476 goto out;
1477 }
1478
1479 list_add_rcu(&data->list, &file->triggers);
1480 ret++;
1481
1482 update_cond_flag(file);
1483 if (trace_event_trigger_enable_disable(file, 1) < 0) {
1484 list_del_rcu(&data->list);
1485 update_cond_flag(file);
1486 ret--;
1487 }
1488out:
1489 return ret;
1490}
1491
1492void event_enable_unregister_trigger(char *glob,
1493 struct event_trigger_ops *ops,
1494 struct event_trigger_data *test,
1495 struct trace_event_file *file)
1496{
1497 struct enable_trigger_data *test_enable_data = test->private_data;
1498 struct enable_trigger_data *enable_data;
1499 struct event_trigger_data *data;
1500 bool unregistered = false;
1501
1502 list_for_each_entry_rcu(data, &file->triggers, list) {
1503 enable_data = data->private_data;
1504 if (enable_data &&
1505 (data->cmd_ops->trigger_type ==
1506 test->cmd_ops->trigger_type) &&
1507 (enable_data->file == test_enable_data->file)) {
1508 unregistered = true;
1509 list_del_rcu(&data->list);
1510 trace_event_trigger_enable_disable(file, 0);
1511 update_cond_flag(file);
1512 break;
1513 }
1514 }
1515
1516 if (unregistered && data->ops->free)
1517 data->ops->free(data->ops, data);
1518}
1519
1520static struct event_trigger_ops *
1521event_enable_get_trigger_ops(char *cmd, char *param)
1522{
1523 struct event_trigger_ops *ops;
1524 bool enable;
1525
1526#ifdef CONFIG_HIST_TRIGGERS
1527 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1528 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1529#else
1530 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1531#endif
1532 if (enable)
1533 ops = param ? &event_enable_count_trigger_ops :
1534 &event_enable_trigger_ops;
1535 else
1536 ops = param ? &event_disable_count_trigger_ops :
1537 &event_disable_trigger_ops;
1538
1539 return ops;
1540}
1541
1542static struct event_command trigger_enable_cmd = {
1543 .name = ENABLE_EVENT_STR,
1544 .trigger_type = ETT_EVENT_ENABLE,
1545 .func = event_enable_trigger_func,
1546 .reg = event_enable_register_trigger,
1547 .unreg = event_enable_unregister_trigger,
1548 .get_trigger_ops = event_enable_get_trigger_ops,
1549 .set_filter = set_trigger_filter,
1550};
1551
1552static struct event_command trigger_disable_cmd = {
1553 .name = DISABLE_EVENT_STR,
1554 .trigger_type = ETT_EVENT_ENABLE,
1555 .func = event_enable_trigger_func,
1556 .reg = event_enable_register_trigger,
1557 .unreg = event_enable_unregister_trigger,
1558 .get_trigger_ops = event_enable_get_trigger_ops,
1559 .set_filter = set_trigger_filter,
1560};
1561
1562static __init void unregister_trigger_enable_disable_cmds(void)
1563{
1564 unregister_event_command(&trigger_enable_cmd);
1565 unregister_event_command(&trigger_disable_cmd);
1566}
1567
1568static __init int register_trigger_enable_disable_cmds(void)
1569{
1570 int ret;
1571
1572 ret = register_event_command(&trigger_enable_cmd);
1573 if (WARN_ON(ret < 0))
1574 return ret;
1575 ret = register_event_command(&trigger_disable_cmd);
1576 if (WARN_ON(ret < 0))
1577 unregister_trigger_enable_disable_cmds();
1578
1579 return ret;
1580}
1581
1582static __init int register_trigger_traceon_traceoff_cmds(void)
1583{
1584 int ret;
1585
1586 ret = register_event_command(&trigger_traceon_cmd);
1587 if (WARN_ON(ret < 0))
1588 return ret;
1589 ret = register_event_command(&trigger_traceoff_cmd);
1590 if (WARN_ON(ret < 0))
1591 unregister_trigger_traceon_traceoff_cmds();
1592
1593 return ret;
1594}
1595
1596__init int register_trigger_cmds(void)
1597{
1598 register_trigger_traceon_traceoff_cmds();
1599 register_trigger_snapshot_cmd();
1600 register_trigger_stacktrace_cmd();
1601 register_trigger_enable_disable_cmds();
1602 register_trigger_hist_enable_disable_cmds();
1603 register_trigger_hist_cmd();
1604
1605 return 0;
1606}