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85f2b082
TZ
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>
b2d09103 25#include <linux/rculist.h>
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TZ
26
27#include "trace.h"
28
29static LIST_HEAD(trigger_commands);
30static DEFINE_MUTEX(trigger_cmd_mutex);
31
ab4bf008 32void trigger_data_free(struct event_trigger_data *data)
2a2df321 33{
bac5fb97
TZ
34 if (data->cmd_ops->set_filter)
35 data->cmd_ops->set_filter(NULL, data, NULL);
36
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TZ
37 synchronize_sched(); /* make sure current triggers exit before free */
38 kfree(data);
39}
40
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41/**
42 * event_triggers_call - Call triggers associated with a trace event
7f1d2f82 43 * @file: The trace_event_file associated with the event
bac5fb97 44 * @rec: The trace entry for the event, NULL for unconditional invocation
85f2b082
TZ
45 *
46 * For each trigger associated with an event, invoke the trigger
bac5fb97
TZ
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.
85f2b082
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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 */
bac5fb97 65enum event_trigger_type
7f1d2f82 66event_triggers_call(struct trace_event_file *file, void *rec)
85f2b082
TZ
67{
68 struct event_trigger_data *data;
bac5fb97 69 enum event_trigger_type tt = ETT_NONE;
d8a30f20 70 struct event_filter *filter;
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71
72 if (list_empty(&file->triggers))
bac5fb97 73 return tt;
85f2b082 74
bac5fb97 75 list_for_each_entry_rcu(data, &file->triggers, list) {
104f2810
TZ
76 if (data->paused)
77 continue;
bac5fb97 78 if (!rec) {
c4a59230 79 data->ops->func(data, rec);
bac5fb97
TZ
80 continue;
81 }
561a4fe8 82 filter = rcu_dereference_sched(data->filter);
d8a30f20 83 if (filter && !filter_match_preds(filter, rec))
bac5fb97 84 continue;
353206f5 85 if (event_command_post_trigger(data->cmd_ops)) {
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TZ
86 tt |= data->cmd_ops->trigger_type;
87 continue;
88 }
c4a59230 89 data->ops->func(data, rec);
bac5fb97
TZ
90 }
91 return tt;
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92}
93EXPORT_SYMBOL_GPL(event_triggers_call);
94
bac5fb97
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95/**
96 * event_triggers_post_call - Call 'post_triggers' for a trace event
7f1d2f82 97 * @file: The trace_event_file associated with the event
bac5fb97 98 * @tt: enum event_trigger_type containing a set bit for each trigger to invoke
c4a59230 99 * @rec: The trace entry for the event
bac5fb97
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100 *
101 * For each trigger associated with an event, invoke the trigger
102 * function registered with the associated trigger command, if the
103 * corresponding bit is set in the tt enum passed into this function.
104 * See @event_triggers_call for details on how those bits are set.
105 *
106 * Called from tracepoint handlers (with rcu_read_lock_sched() held).
107 */
108void
7f1d2f82 109event_triggers_post_call(struct trace_event_file *file,
c4a59230
TZ
110 enum event_trigger_type tt,
111 void *rec)
bac5fb97
TZ
112{
113 struct event_trigger_data *data;
114
115 list_for_each_entry_rcu(data, &file->triggers, list) {
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TZ
116 if (data->paused)
117 continue;
bac5fb97 118 if (data->cmd_ops->trigger_type & tt)
c4a59230 119 data->ops->func(data, rec);
bac5fb97
TZ
120 }
121}
122EXPORT_SYMBOL_GPL(event_triggers_post_call);
123
dd97b954
SRRH
124#define SHOW_AVAILABLE_TRIGGERS (void *)(1UL)
125
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126static void *trigger_next(struct seq_file *m, void *t, loff_t *pos)
127{
7f1d2f82 128 struct trace_event_file *event_file = event_file_data(m->private);
85f2b082 129
dd97b954
SRRH
130 if (t == SHOW_AVAILABLE_TRIGGERS)
131 return NULL;
132
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133 return seq_list_next(t, &event_file->triggers, pos);
134}
135
136static void *trigger_start(struct seq_file *m, loff_t *pos)
137{
7f1d2f82 138 struct trace_event_file *event_file;
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139
140 /* ->stop() is called even if ->start() fails */
141 mutex_lock(&event_mutex);
142 event_file = event_file_data(m->private);
143 if (unlikely(!event_file))
144 return ERR_PTR(-ENODEV);
145
dd97b954
SRRH
146 if (list_empty(&event_file->triggers))
147 return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL;
148
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149 return seq_list_start(&event_file->triggers, *pos);
150}
151
152static void trigger_stop(struct seq_file *m, void *t)
153{
154 mutex_unlock(&event_mutex);
155}
156
157static int trigger_show(struct seq_file *m, void *v)
158{
159 struct event_trigger_data *data;
dd97b954
SRRH
160 struct event_command *p;
161
162 if (v == SHOW_AVAILABLE_TRIGGERS) {
163 seq_puts(m, "# Available triggers:\n");
164 seq_putc(m, '#');
165 mutex_lock(&trigger_cmd_mutex);
166 list_for_each_entry_reverse(p, &trigger_commands, list)
167 seq_printf(m, " %s", p->name);
168 seq_putc(m, '\n');
169 mutex_unlock(&trigger_cmd_mutex);
170 return 0;
171 }
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172
173 data = list_entry(v, struct event_trigger_data, list);
174 data->ops->print(m, data->ops, data);
175
176 return 0;
177}
178
179static const struct seq_operations event_triggers_seq_ops = {
180 .start = trigger_start,
181 .next = trigger_next,
182 .stop = trigger_stop,
183 .show = trigger_show,
184};
185
186static int event_trigger_regex_open(struct inode *inode, struct file *file)
187{
188 int ret = 0;
189
190 mutex_lock(&event_mutex);
191
192 if (unlikely(!event_file_data(file))) {
193 mutex_unlock(&event_mutex);
194 return -ENODEV;
195 }
196
a88e1cfb
TZ
197 if ((file->f_mode & FMODE_WRITE) &&
198 (file->f_flags & O_TRUNC)) {
199 struct trace_event_file *event_file;
200 struct event_command *p;
201
202 event_file = event_file_data(file);
203
204 list_for_each_entry(p, &trigger_commands, list) {
205 if (p->unreg_all)
206 p->unreg_all(event_file);
207 }
208 }
209
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210 if (file->f_mode & FMODE_READ) {
211 ret = seq_open(file, &event_triggers_seq_ops);
212 if (!ret) {
213 struct seq_file *m = file->private_data;
214 m->private = file;
215 }
216 }
217
218 mutex_unlock(&event_mutex);
219
220 return ret;
221}
222
7f1d2f82 223static int trigger_process_regex(struct trace_event_file *file, char *buff)
85f2b082
TZ
224{
225 char *command, *next = buff;
226 struct event_command *p;
227 int ret = -EINVAL;
228
229 command = strsep(&next, ": \t");
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{
7f1d2f82 249 struct trace_event_file *event_file;
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250 ssize_t ret;
251 char *buf;
252
253 if (!cnt)
254 return 0;
255
256 if (cnt >= PAGE_SIZE)
257 return -EINVAL;
258
70f6cbb6
AV
259 buf = memdup_user_nul(ubuf, cnt);
260 if (IS_ERR(buf))
261 return PTR_ERR(buf);
85f2b082 262
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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);
70f6cbb6 269 kfree(buf);
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270 return -ENODEV;
271 }
272 ret = trigger_process_regex(event_file, buf);
273 mutex_unlock(&event_mutex);
274
70f6cbb6 275 kfree(buf);
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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 return event_trigger_regex_open(inode, filp);
308}
309
310static int
311event_trigger_release(struct inode *inode, struct file *file)
312{
313 return event_trigger_regex_release(inode, file);
314}
315
316const struct file_operations event_trigger_fops = {
317 .open = event_trigger_open,
318 .read = seq_read,
319 .write = event_trigger_write,
098c879e 320 .llseek = tracing_lseek,
85f2b082
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321 .release = event_trigger_release,
322};
323
2a2df321
TZ
324/*
325 * Currently we only register event commands from __init, so mark this
326 * __init too.
327 */
ab4bf008 328__init int register_event_command(struct event_command *cmd)
2a2df321
TZ
329{
330 struct event_command *p;
331 int ret = 0;
332
333 mutex_lock(&trigger_cmd_mutex);
334 list_for_each_entry(p, &trigger_commands, list) {
335 if (strcmp(cmd->name, p->name) == 0) {
336 ret = -EBUSY;
337 goto out_unlock;
338 }
339 }
340 list_add(&cmd->list, &trigger_commands);
341 out_unlock:
342 mutex_unlock(&trigger_cmd_mutex);
343
344 return ret;
345}
346
347/*
348 * Currently we only unregister event commands from __init, so mark
349 * this __init too.
350 */
d0bad49b 351__init int unregister_event_command(struct event_command *cmd)
2a2df321
TZ
352{
353 struct event_command *p, *n;
354 int ret = -ENODEV;
355
356 mutex_lock(&trigger_cmd_mutex);
357 list_for_each_entry_safe(p, n, &trigger_commands, list) {
358 if (strcmp(cmd->name, p->name) == 0) {
359 ret = 0;
360 list_del_init(&p->list);
361 goto out_unlock;
362 }
363 }
364 out_unlock:
365 mutex_unlock(&trigger_cmd_mutex);
366
367 return ret;
368}
369
370/**
371 * event_trigger_print - Generic event_trigger_ops @print implementation
372 * @name: The name of the event trigger
373 * @m: The seq_file being printed to
374 * @data: Trigger-specific data
375 * @filter_str: filter_str to print, if present
376 *
377 * Common implementation for event triggers to print themselves.
378 *
379 * Usually wrapped by a function that simply sets the @name of the
380 * trigger command and then invokes this.
381 *
382 * Return: 0 on success, errno otherwise
383 */
384static int
385event_trigger_print(const char *name, struct seq_file *m,
386 void *data, char *filter_str)
387{
388 long count = (long)data;
389
fa6f0cc7 390 seq_puts(m, name);
2a2df321
TZ
391
392 if (count == -1)
393 seq_puts(m, ":unlimited");
394 else
395 seq_printf(m, ":count=%ld", count);
396
397 if (filter_str)
398 seq_printf(m, " if %s\n", filter_str);
399 else
1177e436 400 seq_putc(m, '\n');
2a2df321
TZ
401
402 return 0;
403}
404
405/**
406 * event_trigger_init - Generic event_trigger_ops @init implementation
407 * @ops: The trigger ops associated with the trigger
408 * @data: Trigger-specific data
409 *
410 * Common implementation of event trigger initialization.
411 *
412 * Usually used directly as the @init method in event trigger
413 * implementations.
414 *
415 * Return: 0 on success, errno otherwise
416 */
ab4bf008
TZ
417int event_trigger_init(struct event_trigger_ops *ops,
418 struct event_trigger_data *data)
2a2df321
TZ
419{
420 data->ref++;
421 return 0;
422}
423
424/**
425 * event_trigger_free - Generic event_trigger_ops @free implementation
426 * @ops: The trigger ops associated with the trigger
427 * @data: Trigger-specific data
428 *
429 * Common implementation of event trigger de-initialization.
430 *
431 * Usually used directly as the @free method in event trigger
432 * implementations.
433 */
434static void
435event_trigger_free(struct event_trigger_ops *ops,
436 struct event_trigger_data *data)
437{
438 if (WARN_ON_ONCE(data->ref <= 0))
439 return;
440
441 data->ref--;
442 if (!data->ref)
443 trigger_data_free(data);
444}
445
ab4bf008
TZ
446int trace_event_trigger_enable_disable(struct trace_event_file *file,
447 int trigger_enable)
85f2b082
TZ
448{
449 int ret = 0;
450
451 if (trigger_enable) {
452 if (atomic_inc_return(&file->tm_ref) > 1)
453 return ret;
5d6ad960 454 set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
85f2b082
TZ
455 ret = trace_event_enable_disable(file, 1, 1);
456 } else {
457 if (atomic_dec_return(&file->tm_ref) > 0)
458 return ret;
5d6ad960 459 clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
85f2b082
TZ
460 ret = trace_event_enable_disable(file, 0, 1);
461 }
462
463 return ret;
464}
465
466/**
467 * clear_event_triggers - Clear all triggers associated with a trace array
468 * @tr: The trace array to clear
469 *
470 * For each trigger, the triggering event has its tm_ref decremented
471 * via trace_event_trigger_enable_disable(), and any associated event
472 * (in the case of enable/disable_event triggers) will have its sm_ref
473 * decremented via free()->trace_event_enable_disable(). That
474 * combination effectively reverses the soft-mode/trigger state added
475 * by trigger registration.
476 *
477 * Must be called with event_mutex held.
478 */
479void
480clear_event_triggers(struct trace_array *tr)
481{
7f1d2f82 482 struct trace_event_file *file;
85f2b082
TZ
483
484 list_for_each_entry(file, &tr->events, list) {
485 struct event_trigger_data *data;
486 list_for_each_entry_rcu(data, &file->triggers, list) {
487 trace_event_trigger_enable_disable(file, 0);
488 if (data->ops->free)
489 data->ops->free(data->ops, data);
490 }
491 }
492}
493
bac5fb97
TZ
494/**
495 * update_cond_flag - Set or reset the TRIGGER_COND bit
7f1d2f82 496 * @file: The trace_event_file associated with the event
bac5fb97
TZ
497 *
498 * If an event has triggers and any of those triggers has a filter or
499 * a post_trigger, trigger invocation needs to be deferred until after
500 * the current event has logged its data, and the event should have
501 * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be
502 * cleared.
503 */
ab4bf008 504void update_cond_flag(struct trace_event_file *file)
bac5fb97
TZ
505{
506 struct event_trigger_data *data;
507 bool set_cond = false;
508
509 list_for_each_entry_rcu(data, &file->triggers, list) {
353206f5
SRRH
510 if (data->filter || event_command_post_trigger(data->cmd_ops) ||
511 event_command_needs_rec(data->cmd_ops)) {
bac5fb97
TZ
512 set_cond = true;
513 break;
514 }
515 }
516
517 if (set_cond)
5d6ad960 518 set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
bac5fb97 519 else
5d6ad960 520 clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
bac5fb97
TZ
521}
522
2a2df321
TZ
523/**
524 * register_trigger - Generic event_command @reg implementation
525 * @glob: The raw string used to register the trigger
526 * @ops: The trigger ops associated with the trigger
527 * @data: Trigger-specific data to associate with the trigger
7f1d2f82 528 * @file: The trace_event_file associated with the event
2a2df321
TZ
529 *
530 * Common implementation for event trigger registration.
531 *
532 * Usually used directly as the @reg method in event command
533 * implementations.
534 *
535 * Return: 0 on success, errno otherwise
536 */
537static int register_trigger(char *glob, struct event_trigger_ops *ops,
538 struct event_trigger_data *data,
7f1d2f82 539 struct trace_event_file *file)
2a2df321
TZ
540{
541 struct event_trigger_data *test;
542 int ret = 0;
543
544 list_for_each_entry_rcu(test, &file->triggers, list) {
545 if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) {
546 ret = -EEXIST;
547 goto out;
548 }
549 }
550
551 if (data->ops->init) {
552 ret = data->ops->init(data->ops, data);
553 if (ret < 0)
554 goto out;
555 }
556
557 list_add_rcu(&data->list, &file->triggers);
558 ret++;
559
4e4a4d75 560 update_cond_flag(file);
2a2df321
TZ
561 if (trace_event_trigger_enable_disable(file, 1) < 0) {
562 list_del_rcu(&data->list);
4e4a4d75 563 update_cond_flag(file);
2a2df321
TZ
564 ret--;
565 }
566out:
567 return ret;
568}
569
570/**
571 * unregister_trigger - Generic event_command @unreg implementation
572 * @glob: The raw string used to register the trigger
573 * @ops: The trigger ops associated with the trigger
574 * @test: Trigger-specific data used to find the trigger to remove
7f1d2f82 575 * @file: The trace_event_file associated with the event
2a2df321
TZ
576 *
577 * Common implementation for event trigger unregistration.
578 *
579 * Usually used directly as the @unreg method in event command
580 * implementations.
581 */
ab4bf008
TZ
582void unregister_trigger(char *glob, struct event_trigger_ops *ops,
583 struct event_trigger_data *test,
584 struct trace_event_file *file)
2a2df321
TZ
585{
586 struct event_trigger_data *data;
587 bool unregistered = false;
588
589 list_for_each_entry_rcu(data, &file->triggers, list) {
590 if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
591 unregistered = true;
592 list_del_rcu(&data->list);
593 trace_event_trigger_enable_disable(file, 0);
4e4a4d75 594 update_cond_flag(file);
2a2df321
TZ
595 break;
596 }
597 }
598
599 if (unregistered && data->ops->free)
600 data->ops->free(data->ops, data);
601}
602
603/**
604 * event_trigger_callback - Generic event_command @func implementation
605 * @cmd_ops: The command ops, used for trigger registration
7f1d2f82 606 * @file: The trace_event_file associated with the event
2a2df321
TZ
607 * @glob: The raw string used to register the trigger
608 * @cmd: The cmd portion of the string used to register the trigger
609 * @param: The params portion of the string used to register the trigger
610 *
611 * Common implementation for event command parsing and trigger
612 * instantiation.
613 *
614 * Usually used directly as the @func method in event command
615 * implementations.
616 *
617 * Return: 0 on success, errno otherwise
618 */
619static int
620event_trigger_callback(struct event_command *cmd_ops,
7f1d2f82 621 struct trace_event_file *file,
2a2df321
TZ
622 char *glob, char *cmd, char *param)
623{
624 struct event_trigger_data *trigger_data;
625 struct event_trigger_ops *trigger_ops;
626 char *trigger = NULL;
627 char *number;
628 int ret;
629
630 /* separate the trigger from the filter (t:n [if filter]) */
631 if (param && isdigit(param[0]))
632 trigger = strsep(&param, " \t");
633
634 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
635
636 ret = -ENOMEM;
637 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
638 if (!trigger_data)
639 goto out;
640
641 trigger_data->count = -1;
642 trigger_data->ops = trigger_ops;
643 trigger_data->cmd_ops = cmd_ops;
644 INIT_LIST_HEAD(&trigger_data->list);
db1388b4 645 INIT_LIST_HEAD(&trigger_data->named_list);
2a2df321
TZ
646
647 if (glob[0] == '!') {
648 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
649 kfree(trigger_data);
650 ret = 0;
651 goto out;
652 }
653
654 if (trigger) {
655 number = strsep(&trigger, ":");
656
657 ret = -EINVAL;
658 if (!strlen(number))
659 goto out_free;
660
661 /*
662 * We use the callback data field (which is a pointer)
663 * as our counter.
664 */
665 ret = kstrtoul(number, 0, &trigger_data->count);
666 if (ret)
667 goto out_free;
668 }
669
670 if (!param) /* if param is non-empty, it's supposed to be a filter */
671 goto out_reg;
672
673 if (!cmd_ops->set_filter)
674 goto out_reg;
675
676 ret = cmd_ops->set_filter(param, trigger_data, file);
677 if (ret < 0)
678 goto out_free;
679
680 out_reg:
681 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
682 /*
683 * The above returns on success the # of functions enabled,
684 * but if it didn't find any functions it returns zero.
685 * Consider no functions a failure too.
686 */
687 if (!ret) {
688 ret = -ENOENT;
689 goto out_free;
690 } else if (ret < 0)
691 goto out_free;
692 ret = 0;
693 out:
694 return ret;
695
696 out_free:
bac5fb97
TZ
697 if (cmd_ops->set_filter)
698 cmd_ops->set_filter(NULL, trigger_data, NULL);
2a2df321
TZ
699 kfree(trigger_data);
700 goto out;
701}
702
bac5fb97
TZ
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
7f1d2f82 707 * @file: The trace_event_file associated with the event
bac5fb97
TZ
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 */
ab4bf008
TZ
719int set_trigger_filter(char *filter_str,
720 struct event_trigger_data *trigger_data,
721 struct trace_event_file *file)
bac5fb97
TZ
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->event_call, filter_str, false, &filter);
741 if (ret)
742 goto out;
743 assign:
d8a30f20 744 tmp = rcu_access_pointer(data->filter);
bac5fb97
TZ
745
746 rcu_assign_pointer(data->filter, filter);
747
748 if (tmp) {
749 /* Make sure the call is done with the filter */
750 synchronize_sched();
751 free_event_filter(tmp);
752 }
753
754 kfree(data->filter_str);
755 data->filter_str = NULL;
756
757 if (filter_str) {
758 data->filter_str = kstrdup(filter_str, GFP_KERNEL);
759 if (!data->filter_str) {
d8a30f20 760 free_event_filter(rcu_access_pointer(data->filter));
bac5fb97
TZ
761 data->filter = NULL;
762 ret = -ENOMEM;
763 }
764 }
765 out:
766 return ret;
767}
768
db1388b4
TZ
769static LIST_HEAD(named_triggers);
770
771/**
772 * find_named_trigger - Find the common named trigger associated with @name
773 * @name: The name of the set of named triggers to find the common data for
774 *
775 * Named triggers are sets of triggers that share a common set of
776 * trigger data. The first named trigger registered with a given name
777 * owns the common trigger data that the others subsequently
778 * registered with the same name will reference. This function
779 * returns the common trigger data associated with that first
780 * registered instance.
781 *
782 * Return: the common trigger data for the given named trigger on
783 * success, NULL otherwise.
784 */
785struct event_trigger_data *find_named_trigger(const char *name)
786{
787 struct event_trigger_data *data;
788
789 if (!name)
790 return NULL;
791
792 list_for_each_entry(data, &named_triggers, named_list) {
793 if (data->named_data)
794 continue;
795 if (strcmp(data->name, name) == 0)
796 return data;
797 }
798
799 return NULL;
800}
801
802/**
803 * is_named_trigger - determine if a given trigger is a named trigger
804 * @test: The trigger data to test
805 *
806 * Return: true if 'test' is a named trigger, false otherwise.
807 */
808bool is_named_trigger(struct event_trigger_data *test)
809{
810 struct event_trigger_data *data;
811
812 list_for_each_entry(data, &named_triggers, named_list) {
813 if (test == data)
814 return true;
815 }
816
817 return false;
818}
819
820/**
821 * save_named_trigger - save the trigger in the named trigger list
822 * @name: The name of the named trigger set
823 * @data: The trigger data to save
824 *
825 * Return: 0 if successful, negative error otherwise.
826 */
827int save_named_trigger(const char *name, struct event_trigger_data *data)
828{
829 data->name = kstrdup(name, GFP_KERNEL);
830 if (!data->name)
831 return -ENOMEM;
832
833 list_add(&data->named_list, &named_triggers);
834
835 return 0;
836}
837
838/**
839 * del_named_trigger - delete a trigger from the named trigger list
840 * @data: The trigger data to delete
841 */
842void del_named_trigger(struct event_trigger_data *data)
843{
844 kfree(data->name);
845 data->name = NULL;
846
847 list_del(&data->named_list);
848}
849
850static void __pause_named_trigger(struct event_trigger_data *data, bool pause)
851{
852 struct event_trigger_data *test;
853
854 list_for_each_entry(test, &named_triggers, named_list) {
855 if (strcmp(test->name, data->name) == 0) {
856 if (pause) {
857 test->paused_tmp = test->paused;
858 test->paused = true;
859 } else {
860 test->paused = test->paused_tmp;
861 }
862 }
863 }
864}
865
866/**
867 * pause_named_trigger - Pause all named triggers with the same name
868 * @data: The trigger data of a named trigger to pause
869 *
870 * Pauses a named trigger along with all other triggers having the
871 * same name. Because named triggers share a common set of data,
872 * pausing only one is meaningless, so pausing one named trigger needs
873 * to pause all triggers with the same name.
874 */
875void pause_named_trigger(struct event_trigger_data *data)
876{
877 __pause_named_trigger(data, true);
878}
879
880/**
881 * unpause_named_trigger - Un-pause all named triggers with the same name
882 * @data: The trigger data of a named trigger to unpause
883 *
884 * Un-pauses a named trigger along with all other triggers having the
885 * same name. Because named triggers share a common set of data,
886 * unpausing only one is meaningless, so unpausing one named trigger
887 * needs to unpause all triggers with the same name.
888 */
889void unpause_named_trigger(struct event_trigger_data *data)
890{
891 __pause_named_trigger(data, false);
892}
893
894/**
895 * set_named_trigger_data - Associate common named trigger data
896 * @data: The trigger data of a named trigger to unpause
897 *
898 * Named triggers are sets of triggers that share a common set of
899 * trigger data. The first named trigger registered with a given name
900 * owns the common trigger data that the others subsequently
901 * registered with the same name will reference. This function
902 * associates the common trigger data from the first trigger with the
903 * given trigger.
904 */
905void set_named_trigger_data(struct event_trigger_data *data,
906 struct event_trigger_data *named_data)
907{
908 data->named_data = named_data;
909}
910
2a2df321 911static void
c4a59230 912traceon_trigger(struct event_trigger_data *data, void *rec)
2a2df321
TZ
913{
914 if (tracing_is_on())
915 return;
916
917 tracing_on();
918}
919
920static void
c4a59230 921traceon_count_trigger(struct event_trigger_data *data, void *rec)
2a2df321 922{
e8dc6371
SRRH
923 if (tracing_is_on())
924 return;
925
2a2df321
TZ
926 if (!data->count)
927 return;
928
929 if (data->count != -1)
930 (data->count)--;
931
e8dc6371 932 tracing_on();
2a2df321
TZ
933}
934
935static void
c4a59230 936traceoff_trigger(struct event_trigger_data *data, void *rec)
2a2df321
TZ
937{
938 if (!tracing_is_on())
939 return;
940
941 tracing_off();
942}
943
944static void
c4a59230 945traceoff_count_trigger(struct event_trigger_data *data, void *rec)
2a2df321 946{
e8dc6371
SRRH
947 if (!tracing_is_on())
948 return;
949
2a2df321
TZ
950 if (!data->count)
951 return;
952
953 if (data->count != -1)
954 (data->count)--;
955
e8dc6371 956 tracing_off();
2a2df321
TZ
957}
958
959static int
960traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
961 struct event_trigger_data *data)
962{
963 return event_trigger_print("traceon", m, (void *)data->count,
964 data->filter_str);
965}
966
967static int
968traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
969 struct event_trigger_data *data)
970{
971 return event_trigger_print("traceoff", m, (void *)data->count,
972 data->filter_str);
973}
974
975static struct event_trigger_ops traceon_trigger_ops = {
976 .func = traceon_trigger,
977 .print = traceon_trigger_print,
978 .init = event_trigger_init,
979 .free = event_trigger_free,
980};
981
982static struct event_trigger_ops traceon_count_trigger_ops = {
983 .func = traceon_count_trigger,
984 .print = traceon_trigger_print,
985 .init = event_trigger_init,
986 .free = event_trigger_free,
987};
988
989static struct event_trigger_ops traceoff_trigger_ops = {
990 .func = traceoff_trigger,
991 .print = traceoff_trigger_print,
992 .init = event_trigger_init,
993 .free = event_trigger_free,
994};
995
996static struct event_trigger_ops traceoff_count_trigger_ops = {
997 .func = traceoff_count_trigger,
998 .print = traceoff_trigger_print,
999 .init = event_trigger_init,
1000 .free = event_trigger_free,
1001};
1002
1003static struct event_trigger_ops *
1004onoff_get_trigger_ops(char *cmd, char *param)
1005{
1006 struct event_trigger_ops *ops;
1007
1008 /* we register both traceon and traceoff to this callback */
1009 if (strcmp(cmd, "traceon") == 0)
1010 ops = param ? &traceon_count_trigger_ops :
1011 &traceon_trigger_ops;
1012 else
1013 ops = param ? &traceoff_count_trigger_ops :
1014 &traceoff_trigger_ops;
1015
1016 return ops;
1017}
1018
1019static struct event_command trigger_traceon_cmd = {
1020 .name = "traceon",
1021 .trigger_type = ETT_TRACE_ONOFF,
1022 .func = event_trigger_callback,
1023 .reg = register_trigger,
1024 .unreg = unregister_trigger,
1025 .get_trigger_ops = onoff_get_trigger_ops,
bac5fb97 1026 .set_filter = set_trigger_filter,
2a2df321
TZ
1027};
1028
1029static struct event_command trigger_traceoff_cmd = {
1030 .name = "traceoff",
1031 .trigger_type = ETT_TRACE_ONOFF,
a0d0c621 1032 .flags = EVENT_CMD_FL_POST_TRIGGER,
2a2df321
TZ
1033 .func = event_trigger_callback,
1034 .reg = register_trigger,
1035 .unreg = unregister_trigger,
1036 .get_trigger_ops = onoff_get_trigger_ops,
bac5fb97 1037 .set_filter = set_trigger_filter,
2a2df321
TZ
1038};
1039
93e31ffb
TZ
1040#ifdef CONFIG_TRACER_SNAPSHOT
1041static void
c4a59230 1042snapshot_trigger(struct event_trigger_data *data, void *rec)
93e31ffb
TZ
1043{
1044 tracing_snapshot();
1045}
1046
1047static void
c4a59230 1048snapshot_count_trigger(struct event_trigger_data *data, void *rec)
93e31ffb
TZ
1049{
1050 if (!data->count)
1051 return;
1052
1053 if (data->count != -1)
1054 (data->count)--;
1055
c4a59230 1056 snapshot_trigger(data, rec);
93e31ffb
TZ
1057}
1058
1059static int
1060register_snapshot_trigger(char *glob, struct event_trigger_ops *ops,
1061 struct event_trigger_data *data,
7f1d2f82 1062 struct trace_event_file *file)
93e31ffb
TZ
1063{
1064 int ret = register_trigger(glob, ops, data, file);
1065
1066 if (ret > 0 && tracing_alloc_snapshot() != 0) {
1067 unregister_trigger(glob, ops, data, file);
1068 ret = 0;
1069 }
1070
1071 return ret;
1072}
1073
1074static int
1075snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1076 struct event_trigger_data *data)
1077{
1078 return event_trigger_print("snapshot", m, (void *)data->count,
1079 data->filter_str);
1080}
1081
1082static struct event_trigger_ops snapshot_trigger_ops = {
1083 .func = snapshot_trigger,
1084 .print = snapshot_trigger_print,
1085 .init = event_trigger_init,
1086 .free = event_trigger_free,
1087};
1088
1089static struct event_trigger_ops snapshot_count_trigger_ops = {
1090 .func = snapshot_count_trigger,
1091 .print = snapshot_trigger_print,
1092 .init = event_trigger_init,
1093 .free = event_trigger_free,
1094};
1095
1096static struct event_trigger_ops *
1097snapshot_get_trigger_ops(char *cmd, char *param)
1098{
1099 return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
1100}
1101
1102static struct event_command trigger_snapshot_cmd = {
1103 .name = "snapshot",
1104 .trigger_type = ETT_SNAPSHOT,
1105 .func = event_trigger_callback,
1106 .reg = register_snapshot_trigger,
1107 .unreg = unregister_trigger,
1108 .get_trigger_ops = snapshot_get_trigger_ops,
bac5fb97 1109 .set_filter = set_trigger_filter,
93e31ffb
TZ
1110};
1111
1112static __init int register_trigger_snapshot_cmd(void)
1113{
1114 int ret;
1115
1116 ret = register_event_command(&trigger_snapshot_cmd);
1117 WARN_ON(ret < 0);
1118
1119 return ret;
1120}
1121#else
1122static __init int register_trigger_snapshot_cmd(void) { return 0; }
1123#endif /* CONFIG_TRACER_SNAPSHOT */
1124
f21ecbb3
TZ
1125#ifdef CONFIG_STACKTRACE
1126/*
1127 * Skip 3:
1128 * stacktrace_trigger()
1129 * event_triggers_post_call()
a7237765 1130 * trace_event_raw_event_xxx()
f21ecbb3
TZ
1131 */
1132#define STACK_SKIP 3
1133
1134static void
c4a59230 1135stacktrace_trigger(struct event_trigger_data *data, void *rec)
f21ecbb3
TZ
1136{
1137 trace_dump_stack(STACK_SKIP);
1138}
1139
1140static void
c4a59230 1141stacktrace_count_trigger(struct event_trigger_data *data, void *rec)
f21ecbb3
TZ
1142{
1143 if (!data->count)
1144 return;
1145
1146 if (data->count != -1)
1147 (data->count)--;
1148
c4a59230 1149 stacktrace_trigger(data, rec);
f21ecbb3
TZ
1150}
1151
1152static int
1153stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1154 struct event_trigger_data *data)
1155{
1156 return event_trigger_print("stacktrace", m, (void *)data->count,
1157 data->filter_str);
1158}
1159
1160static struct event_trigger_ops stacktrace_trigger_ops = {
1161 .func = stacktrace_trigger,
1162 .print = stacktrace_trigger_print,
1163 .init = event_trigger_init,
1164 .free = event_trigger_free,
1165};
1166
1167static struct event_trigger_ops stacktrace_count_trigger_ops = {
1168 .func = stacktrace_count_trigger,
1169 .print = stacktrace_trigger_print,
1170 .init = event_trigger_init,
1171 .free = event_trigger_free,
1172};
1173
1174static struct event_trigger_ops *
1175stacktrace_get_trigger_ops(char *cmd, char *param)
1176{
1177 return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
1178}
1179
1180static struct event_command trigger_stacktrace_cmd = {
1181 .name = "stacktrace",
1182 .trigger_type = ETT_STACKTRACE,
353206f5 1183 .flags = EVENT_CMD_FL_POST_TRIGGER,
f21ecbb3
TZ
1184 .func = event_trigger_callback,
1185 .reg = register_trigger,
1186 .unreg = unregister_trigger,
1187 .get_trigger_ops = stacktrace_get_trigger_ops,
bac5fb97 1188 .set_filter = set_trigger_filter,
f21ecbb3
TZ
1189};
1190
1191static __init int register_trigger_stacktrace_cmd(void)
1192{
1193 int ret;
1194
1195 ret = register_event_command(&trigger_stacktrace_cmd);
1196 WARN_ON(ret < 0);
1197
1198 return ret;
1199}
1200#else
1201static __init int register_trigger_stacktrace_cmd(void) { return 0; }
1202#endif /* CONFIG_STACKTRACE */
1203
2a2df321
TZ
1204static __init void unregister_trigger_traceon_traceoff_cmds(void)
1205{
1206 unregister_event_command(&trigger_traceon_cmd);
1207 unregister_event_command(&trigger_traceoff_cmd);
1208}
1209
7862ad18 1210static void
c4a59230 1211event_enable_trigger(struct event_trigger_data *data, void *rec)
7862ad18
TZ
1212{
1213 struct enable_trigger_data *enable_data = data->private_data;
1214
1215 if (enable_data->enable)
5d6ad960 1216 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
7862ad18 1217 else
5d6ad960 1218 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
7862ad18
TZ
1219}
1220
1221static void
c4a59230 1222event_enable_count_trigger(struct event_trigger_data *data, void *rec)
7862ad18
TZ
1223{
1224 struct enable_trigger_data *enable_data = data->private_data;
1225
1226 if (!data->count)
1227 return;
1228
1229 /* Skip if the event is in a state we want to switch to */
5d6ad960 1230 if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
7862ad18
TZ
1231 return;
1232
1233 if (data->count != -1)
1234 (data->count)--;
1235
c4a59230 1236 event_enable_trigger(data, rec);
7862ad18
TZ
1237}
1238
d0bad49b
TZ
1239int event_enable_trigger_print(struct seq_file *m,
1240 struct event_trigger_ops *ops,
1241 struct event_trigger_data *data)
7862ad18
TZ
1242{
1243 struct enable_trigger_data *enable_data = data->private_data;
1244
1245 seq_printf(m, "%s:%s:%s",
d0bad49b
TZ
1246 enable_data->hist ?
1247 (enable_data->enable ? ENABLE_HIST_STR : DISABLE_HIST_STR) :
1248 (enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR),
7862ad18 1249 enable_data->file->event_call->class->system,
687fcc4a 1250 trace_event_name(enable_data->file->event_call));
7862ad18
TZ
1251
1252 if (data->count == -1)
1253 seq_puts(m, ":unlimited");
1254 else
1255 seq_printf(m, ":count=%ld", data->count);
1256
1257 if (data->filter_str)
1258 seq_printf(m, " if %s\n", data->filter_str);
1259 else
1177e436 1260 seq_putc(m, '\n');
7862ad18
TZ
1261
1262 return 0;
1263}
1264
d0bad49b
TZ
1265void event_enable_trigger_free(struct event_trigger_ops *ops,
1266 struct event_trigger_data *data)
7862ad18
TZ
1267{
1268 struct enable_trigger_data *enable_data = data->private_data;
1269
1270 if (WARN_ON_ONCE(data->ref <= 0))
1271 return;
1272
1273 data->ref--;
1274 if (!data->ref) {
1275 /* Remove the SOFT_MODE flag */
1276 trace_event_enable_disable(enable_data->file, 0, 1);
1277 module_put(enable_data->file->event_call->mod);
1278 trigger_data_free(data);
1279 kfree(enable_data);
1280 }
1281}
1282
1283static struct event_trigger_ops event_enable_trigger_ops = {
1284 .func = event_enable_trigger,
1285 .print = event_enable_trigger_print,
1286 .init = event_trigger_init,
1287 .free = event_enable_trigger_free,
1288};
1289
1290static struct event_trigger_ops event_enable_count_trigger_ops = {
1291 .func = event_enable_count_trigger,
1292 .print = event_enable_trigger_print,
1293 .init = event_trigger_init,
1294 .free = event_enable_trigger_free,
1295};
1296
1297static struct event_trigger_ops event_disable_trigger_ops = {
1298 .func = event_enable_trigger,
1299 .print = event_enable_trigger_print,
1300 .init = event_trigger_init,
1301 .free = event_enable_trigger_free,
1302};
1303
1304static struct event_trigger_ops event_disable_count_trigger_ops = {
1305 .func = event_enable_count_trigger,
1306 .print = event_enable_trigger_print,
1307 .init = event_trigger_init,
1308 .free = event_enable_trigger_free,
1309};
1310
d0bad49b
TZ
1311int event_enable_trigger_func(struct event_command *cmd_ops,
1312 struct trace_event_file *file,
1313 char *glob, char *cmd, char *param)
7862ad18 1314{
7f1d2f82 1315 struct trace_event_file *event_enable_file;
7862ad18
TZ
1316 struct enable_trigger_data *enable_data;
1317 struct event_trigger_data *trigger_data;
1318 struct event_trigger_ops *trigger_ops;
1319 struct trace_array *tr = file->tr;
1320 const char *system;
1321 const char *event;
d0bad49b 1322 bool hist = false;
7862ad18
TZ
1323 char *trigger;
1324 char *number;
1325 bool enable;
1326 int ret;
1327
1328 if (!param)
1329 return -EINVAL;
1330
1331 /* separate the trigger from the filter (s:e:n [if filter]) */
1332 trigger = strsep(&param, " \t");
1333 if (!trigger)
1334 return -EINVAL;
1335
1336 system = strsep(&trigger, ":");
1337 if (!trigger)
1338 return -EINVAL;
1339
1340 event = strsep(&trigger, ":");
1341
1342 ret = -EINVAL;
1343 event_enable_file = find_event_file(tr, system, event);
1344 if (!event_enable_file)
1345 goto out;
1346
d0bad49b
TZ
1347#ifdef CONFIG_HIST_TRIGGERS
1348 hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) ||
1349 (strcmp(cmd, DISABLE_HIST_STR) == 0));
7862ad18 1350
d0bad49b
TZ
1351 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1352 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1353#else
1354 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1355#endif
7862ad18
TZ
1356 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
1357
1358 ret = -ENOMEM;
1359 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
1360 if (!trigger_data)
1361 goto out;
1362
1363 enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
1364 if (!enable_data) {
1365 kfree(trigger_data);
1366 goto out;
1367 }
1368
1369 trigger_data->count = -1;
1370 trigger_data->ops = trigger_ops;
1371 trigger_data->cmd_ops = cmd_ops;
1372 INIT_LIST_HEAD(&trigger_data->list);
1373 RCU_INIT_POINTER(trigger_data->filter, NULL);
1374
d0bad49b 1375 enable_data->hist = hist;
7862ad18
TZ
1376 enable_data->enable = enable;
1377 enable_data->file = event_enable_file;
1378 trigger_data->private_data = enable_data;
1379
1380 if (glob[0] == '!') {
1381 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
1382 kfree(trigger_data);
1383 kfree(enable_data);
1384 ret = 0;
1385 goto out;
1386 }
1387
1388 if (trigger) {
1389 number = strsep(&trigger, ":");
1390
1391 ret = -EINVAL;
1392 if (!strlen(number))
1393 goto out_free;
1394
1395 /*
1396 * We use the callback data field (which is a pointer)
1397 * as our counter.
1398 */
1399 ret = kstrtoul(number, 0, &trigger_data->count);
1400 if (ret)
1401 goto out_free;
1402 }
1403
1404 if (!param) /* if param is non-empty, it's supposed to be a filter */
1405 goto out_reg;
1406
1407 if (!cmd_ops->set_filter)
1408 goto out_reg;
1409
1410 ret = cmd_ops->set_filter(param, trigger_data, file);
1411 if (ret < 0)
1412 goto out_free;
1413
1414 out_reg:
1415 /* Don't let event modules unload while probe registered */
1416 ret = try_module_get(event_enable_file->event_call->mod);
1417 if (!ret) {
1418 ret = -EBUSY;
1419 goto out_free;
1420 }
1421
1422 ret = trace_event_enable_disable(event_enable_file, 1, 1);
1423 if (ret < 0)
1424 goto out_put;
1425 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1426 /*
1427 * The above returns on success the # of functions enabled,
1428 * but if it didn't find any functions it returns zero.
1429 * Consider no functions a failure too.
1430 */
1431 if (!ret) {
1432 ret = -ENOENT;
1433 goto out_disable;
1434 } else if (ret < 0)
1435 goto out_disable;
1436 /* Just return zero, not the number of enabled functions */
1437 ret = 0;
1438 out:
1439 return ret;
1440
1441 out_disable:
1442 trace_event_enable_disable(event_enable_file, 0, 1);
1443 out_put:
1444 module_put(event_enable_file->event_call->mod);
1445 out_free:
bac5fb97
TZ
1446 if (cmd_ops->set_filter)
1447 cmd_ops->set_filter(NULL, trigger_data, NULL);
7862ad18
TZ
1448 kfree(trigger_data);
1449 kfree(enable_data);
1450 goto out;
1451}
1452
d0bad49b
TZ
1453int event_enable_register_trigger(char *glob,
1454 struct event_trigger_ops *ops,
1455 struct event_trigger_data *data,
1456 struct trace_event_file *file)
7862ad18
TZ
1457{
1458 struct enable_trigger_data *enable_data = data->private_data;
1459 struct enable_trigger_data *test_enable_data;
1460 struct event_trigger_data *test;
1461 int ret = 0;
1462
1463 list_for_each_entry_rcu(test, &file->triggers, list) {
1464 test_enable_data = test->private_data;
1465 if (test_enable_data &&
d0bad49b
TZ
1466 (test->cmd_ops->trigger_type ==
1467 data->cmd_ops->trigger_type) &&
7862ad18
TZ
1468 (test_enable_data->file == enable_data->file)) {
1469 ret = -EEXIST;
1470 goto out;
1471 }
1472 }
1473
1474 if (data->ops->init) {
1475 ret = data->ops->init(data->ops, data);
1476 if (ret < 0)
1477 goto out;
1478 }
1479
1480 list_add_rcu(&data->list, &file->triggers);
1481 ret++;
1482
4e4a4d75 1483 update_cond_flag(file);
7862ad18
TZ
1484 if (trace_event_trigger_enable_disable(file, 1) < 0) {
1485 list_del_rcu(&data->list);
4e4a4d75 1486 update_cond_flag(file);
7862ad18
TZ
1487 ret--;
1488 }
1489out:
1490 return ret;
1491}
1492
d0bad49b
TZ
1493void event_enable_unregister_trigger(char *glob,
1494 struct event_trigger_ops *ops,
1495 struct event_trigger_data *test,
1496 struct trace_event_file *file)
7862ad18
TZ
1497{
1498 struct enable_trigger_data *test_enable_data = test->private_data;
1499 struct enable_trigger_data *enable_data;
1500 struct event_trigger_data *data;
1501 bool unregistered = false;
1502
1503 list_for_each_entry_rcu(data, &file->triggers, list) {
1504 enable_data = data->private_data;
1505 if (enable_data &&
d0bad49b
TZ
1506 (data->cmd_ops->trigger_type ==
1507 test->cmd_ops->trigger_type) &&
7862ad18
TZ
1508 (enable_data->file == test_enable_data->file)) {
1509 unregistered = true;
1510 list_del_rcu(&data->list);
1511 trace_event_trigger_enable_disable(file, 0);
4e4a4d75 1512 update_cond_flag(file);
7862ad18
TZ
1513 break;
1514 }
1515 }
1516
1517 if (unregistered && data->ops->free)
1518 data->ops->free(data->ops, data);
1519}
1520
1521static struct event_trigger_ops *
1522event_enable_get_trigger_ops(char *cmd, char *param)
1523{
1524 struct event_trigger_ops *ops;
1525 bool enable;
1526
d0bad49b
TZ
1527#ifdef CONFIG_HIST_TRIGGERS
1528 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1529 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1530#else
7862ad18 1531 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
d0bad49b 1532#endif
7862ad18
TZ
1533 if (enable)
1534 ops = param ? &event_enable_count_trigger_ops :
1535 &event_enable_trigger_ops;
1536 else
1537 ops = param ? &event_disable_count_trigger_ops :
1538 &event_disable_trigger_ops;
1539
1540 return ops;
1541}
1542
1543static struct event_command trigger_enable_cmd = {
1544 .name = ENABLE_EVENT_STR,
1545 .trigger_type = ETT_EVENT_ENABLE,
1546 .func = event_enable_trigger_func,
1547 .reg = event_enable_register_trigger,
1548 .unreg = event_enable_unregister_trigger,
1549 .get_trigger_ops = event_enable_get_trigger_ops,
bac5fb97 1550 .set_filter = set_trigger_filter,
7862ad18
TZ
1551};
1552
1553static struct event_command trigger_disable_cmd = {
1554 .name = DISABLE_EVENT_STR,
1555 .trigger_type = ETT_EVENT_ENABLE,
1556 .func = event_enable_trigger_func,
1557 .reg = event_enable_register_trigger,
1558 .unreg = event_enable_unregister_trigger,
1559 .get_trigger_ops = event_enable_get_trigger_ops,
bac5fb97 1560 .set_filter = set_trigger_filter,
7862ad18
TZ
1561};
1562
1563static __init void unregister_trigger_enable_disable_cmds(void)
1564{
1565 unregister_event_command(&trigger_enable_cmd);
1566 unregister_event_command(&trigger_disable_cmd);
1567}
1568
1569static __init int register_trigger_enable_disable_cmds(void)
1570{
1571 int ret;
1572
1573 ret = register_event_command(&trigger_enable_cmd);
1574 if (WARN_ON(ret < 0))
1575 return ret;
1576 ret = register_event_command(&trigger_disable_cmd);
1577 if (WARN_ON(ret < 0))
1578 unregister_trigger_enable_disable_cmds();
1579
1580 return ret;
1581}
1582
2a2df321
TZ
1583static __init int register_trigger_traceon_traceoff_cmds(void)
1584{
1585 int ret;
1586
1587 ret = register_event_command(&trigger_traceon_cmd);
1588 if (WARN_ON(ret < 0))
1589 return ret;
1590 ret = register_event_command(&trigger_traceoff_cmd);
1591 if (WARN_ON(ret < 0))
1592 unregister_trigger_traceon_traceoff_cmds();
1593
1594 return ret;
1595}
1596
85f2b082
TZ
1597__init int register_trigger_cmds(void)
1598{
2a2df321 1599 register_trigger_traceon_traceoff_cmds();
93e31ffb 1600 register_trigger_snapshot_cmd();
f21ecbb3 1601 register_trigger_stacktrace_cmd();
7862ad18 1602 register_trigger_enable_disable_cmds();
d0bad49b 1603 register_trigger_hist_enable_disable_cmds();
7ef224d1 1604 register_trigger_hist_cmd();
2a2df321 1605
85f2b082
TZ
1606 return 0;
1607}