Linux 4.15.6
[linux/fpc-iii.git] / kernel / trace / trace_events_trigger.c
blob87411482a46f2753685c9eab3d9e91830d7ae47d
1 /*
2 * trace_events_trigger - trace event triggers
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.
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.
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.
18 * Copyright (C) 2013 Tom Zanussi <tom.zanussi@linux.intel.com>
21 #include <linux/module.h>
22 #include <linux/ctype.h>
23 #include <linux/mutex.h>
24 #include <linux/slab.h>
25 #include <linux/rculist.h>
27 #include "trace.h"
29 static LIST_HEAD(trigger_commands);
30 static DEFINE_MUTEX(trigger_cmd_mutex);
32 void trigger_data_free(struct event_trigger_data *data)
34 if (data->cmd_ops->set_filter)
35 data->cmd_ops->set_filter(NULL, data, NULL);
37 synchronize_sched(); /* make sure current triggers exit before free */
38 kfree(data);
41 /**
42 * event_triggers_call - Call triggers associated with a trace event
43 * @file: The trace_event_file associated with the event
44 * @rec: The trace entry for the event, NULL for unconditional invocation
46 * For each trigger associated with an event, invoke the trigger
47 * function registered with the associated trigger command. If rec is
48 * non-NULL, it means that the trigger requires further processing and
49 * shouldn't be unconditionally invoked. If rec is non-NULL and the
50 * trigger has a filter associated with it, rec will checked against
51 * the filter and if the record matches the trigger will be invoked.
52 * If the trigger is a 'post_trigger', meaning it shouldn't be invoked
53 * in any case until the current event is written, the trigger
54 * function isn't invoked but the bit associated with the deferred
55 * trigger is set in the return value.
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.
60 * Called from tracepoint handlers (with rcu_read_lock_sched() held).
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.
65 enum event_trigger_type
66 event_triggers_call(struct trace_event_file *file, void *rec)
68 struct event_trigger_data *data;
69 enum event_trigger_type tt = ETT_NONE;
70 struct event_filter *filter;
72 if (list_empty(&file->triggers))
73 return tt;
75 list_for_each_entry_rcu(data, &file->triggers, list) {
76 if (data->paused)
77 continue;
78 if (!rec) {
79 data->ops->func(data, rec);
80 continue;
82 filter = rcu_dereference_sched(data->filter);
83 if (filter && !filter_match_preds(filter, rec))
84 continue;
85 if (event_command_post_trigger(data->cmd_ops)) {
86 tt |= data->cmd_ops->trigger_type;
87 continue;
89 data->ops->func(data, rec);
91 return tt;
93 EXPORT_SYMBOL_GPL(event_triggers_call);
95 /**
96 * event_triggers_post_call - Call 'post_triggers' for a trace event
97 * @file: The trace_event_file associated with the event
98 * @tt: enum event_trigger_type containing a set bit for each trigger to invoke
99 * @rec: The trace entry for the event
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.
106 * Called from tracepoint handlers (with rcu_read_lock_sched() held).
108 void
109 event_triggers_post_call(struct trace_event_file *file,
110 enum event_trigger_type tt,
111 void *rec)
113 struct event_trigger_data *data;
115 list_for_each_entry_rcu(data, &file->triggers, list) {
116 if (data->paused)
117 continue;
118 if (data->cmd_ops->trigger_type & tt)
119 data->ops->func(data, rec);
122 EXPORT_SYMBOL_GPL(event_triggers_post_call);
124 #define SHOW_AVAILABLE_TRIGGERS (void *)(1UL)
126 static void *trigger_next(struct seq_file *m, void *t, loff_t *pos)
128 struct trace_event_file *event_file = event_file_data(m->private);
130 if (t == SHOW_AVAILABLE_TRIGGERS)
131 return NULL;
133 return seq_list_next(t, &event_file->triggers, pos);
136 static void *trigger_start(struct seq_file *m, loff_t *pos)
138 struct trace_event_file *event_file;
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);
146 if (list_empty(&event_file->triggers))
147 return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL;
149 return seq_list_start(&event_file->triggers, *pos);
152 static void trigger_stop(struct seq_file *m, void *t)
154 mutex_unlock(&event_mutex);
157 static int trigger_show(struct seq_file *m, void *v)
159 struct event_trigger_data *data;
160 struct event_command *p;
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;
173 data = list_entry(v, struct event_trigger_data, list);
174 data->ops->print(m, data->ops, data);
176 return 0;
179 static const struct seq_operations event_triggers_seq_ops = {
180 .start = trigger_start,
181 .next = trigger_next,
182 .stop = trigger_stop,
183 .show = trigger_show,
186 static int event_trigger_regex_open(struct inode *inode, struct file *file)
188 int ret = 0;
190 mutex_lock(&event_mutex);
192 if (unlikely(!event_file_data(file))) {
193 mutex_unlock(&event_mutex);
194 return -ENODEV;
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;
202 event_file = event_file_data(file);
204 list_for_each_entry(p, &trigger_commands, list) {
205 if (p->unreg_all)
206 p->unreg_all(event_file);
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;
218 mutex_unlock(&event_mutex);
220 return ret;
223 static int trigger_process_regex(struct trace_event_file *file, char *buff)
225 char *command, *next = buff;
226 struct event_command *p;
227 int ret = -EINVAL;
229 command = strsep(&next, ": \t");
230 command = (command[0] != '!') ? command : command + 1;
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;
239 out_unlock:
240 mutex_unlock(&trigger_cmd_mutex);
242 return ret;
245 static ssize_t event_trigger_regex_write(struct file *file,
246 const char __user *ubuf,
247 size_t cnt, loff_t *ppos)
249 struct trace_event_file *event_file;
250 ssize_t ret;
251 char *buf;
253 if (!cnt)
254 return 0;
256 if (cnt >= PAGE_SIZE)
257 return -EINVAL;
259 buf = memdup_user_nul(ubuf, cnt);
260 if (IS_ERR(buf))
261 return PTR_ERR(buf);
263 strim(buf);
265 mutex_lock(&event_mutex);
266 event_file = event_file_data(file);
267 if (unlikely(!event_file)) {
268 mutex_unlock(&event_mutex);
269 kfree(buf);
270 return -ENODEV;
272 ret = trigger_process_regex(event_file, buf);
273 mutex_unlock(&event_mutex);
275 kfree(buf);
276 if (ret < 0)
277 goto out;
279 *ppos += cnt;
280 ret = cnt;
281 out:
282 return ret;
285 static int event_trigger_regex_release(struct inode *inode, struct file *file)
287 mutex_lock(&event_mutex);
289 if (file->f_mode & FMODE_READ)
290 seq_release(inode, file);
292 mutex_unlock(&event_mutex);
294 return 0;
297 static ssize_t
298 event_trigger_write(struct file *filp, const char __user *ubuf,
299 size_t cnt, loff_t *ppos)
301 return event_trigger_regex_write(filp, ubuf, cnt, ppos);
304 static int
305 event_trigger_open(struct inode *inode, struct file *filp)
307 return event_trigger_regex_open(inode, filp);
310 static int
311 event_trigger_release(struct inode *inode, struct file *file)
313 return event_trigger_regex_release(inode, file);
316 const struct file_operations event_trigger_fops = {
317 .open = event_trigger_open,
318 .read = seq_read,
319 .write = event_trigger_write,
320 .llseek = tracing_lseek,
321 .release = event_trigger_release,
325 * Currently we only register event commands from __init, so mark this
326 * __init too.
328 __init int register_event_command(struct event_command *cmd)
330 struct event_command *p;
331 int ret = 0;
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;
340 list_add(&cmd->list, &trigger_commands);
341 out_unlock:
342 mutex_unlock(&trigger_cmd_mutex);
344 return ret;
348 * Currently we only unregister event commands from __init, so mark
349 * this __init too.
351 __init int unregister_event_command(struct event_command *cmd)
353 struct event_command *p, *n;
354 int ret = -ENODEV;
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;
364 out_unlock:
365 mutex_unlock(&trigger_cmd_mutex);
367 return ret;
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
377 * Common implementation for event triggers to print themselves.
379 * Usually wrapped by a function that simply sets the @name of the
380 * trigger command and then invokes this.
382 * Return: 0 on success, errno otherwise
384 static int
385 event_trigger_print(const char *name, struct seq_file *m,
386 void *data, char *filter_str)
388 long count = (long)data;
390 seq_puts(m, name);
392 if (count == -1)
393 seq_puts(m, ":unlimited");
394 else
395 seq_printf(m, ":count=%ld", count);
397 if (filter_str)
398 seq_printf(m, " if %s\n", filter_str);
399 else
400 seq_putc(m, '\n');
402 return 0;
406 * event_trigger_init - Generic event_trigger_ops @init implementation
407 * @ops: The trigger ops associated with the trigger
408 * @data: Trigger-specific data
410 * Common implementation of event trigger initialization.
412 * Usually used directly as the @init method in event trigger
413 * implementations.
415 * Return: 0 on success, errno otherwise
417 int event_trigger_init(struct event_trigger_ops *ops,
418 struct event_trigger_data *data)
420 data->ref++;
421 return 0;
425 * event_trigger_free - Generic event_trigger_ops @free implementation
426 * @ops: The trigger ops associated with the trigger
427 * @data: Trigger-specific data
429 * Common implementation of event trigger de-initialization.
431 * Usually used directly as the @free method in event trigger
432 * implementations.
434 static void
435 event_trigger_free(struct event_trigger_ops *ops,
436 struct event_trigger_data *data)
438 if (WARN_ON_ONCE(data->ref <= 0))
439 return;
441 data->ref--;
442 if (!data->ref)
443 trigger_data_free(data);
446 int trace_event_trigger_enable_disable(struct trace_event_file *file,
447 int trigger_enable)
449 int ret = 0;
451 if (trigger_enable) {
452 if (atomic_inc_return(&file->tm_ref) > 1)
453 return ret;
454 set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
455 ret = trace_event_enable_disable(file, 1, 1);
456 } else {
457 if (atomic_dec_return(&file->tm_ref) > 0)
458 return ret;
459 clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
460 ret = trace_event_enable_disable(file, 0, 1);
463 return ret;
467 * clear_event_triggers - Clear all triggers associated with a trace array
468 * @tr: The trace array to clear
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.
477 * Must be called with event_mutex held.
479 void
480 clear_event_triggers(struct trace_array *tr)
482 struct trace_event_file *file;
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);
495 * update_cond_flag - Set or reset the TRIGGER_COND bit
496 * @file: The trace_event_file associated with the event
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.
504 void update_cond_flag(struct trace_event_file *file)
506 struct event_trigger_data *data;
507 bool set_cond = false;
509 list_for_each_entry_rcu(data, &file->triggers, list) {
510 if (data->filter || event_command_post_trigger(data->cmd_ops) ||
511 event_command_needs_rec(data->cmd_ops)) {
512 set_cond = true;
513 break;
517 if (set_cond)
518 set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
519 else
520 clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
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
528 * @file: The trace_event_file associated with the event
530 * Common implementation for event trigger registration.
532 * Usually used directly as the @reg method in event command
533 * implementations.
535 * Return: 0 on success, errno otherwise
537 static int register_trigger(char *glob, struct event_trigger_ops *ops,
538 struct event_trigger_data *data,
539 struct trace_event_file *file)
541 struct event_trigger_data *test;
542 int ret = 0;
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;
551 if (data->ops->init) {
552 ret = data->ops->init(data->ops, data);
553 if (ret < 0)
554 goto out;
557 list_add_rcu(&data->list, &file->triggers);
558 ret++;
560 update_cond_flag(file);
561 if (trace_event_trigger_enable_disable(file, 1) < 0) {
562 list_del_rcu(&data->list);
563 update_cond_flag(file);
564 ret--;
566 out:
567 return ret;
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
575 * @file: The trace_event_file associated with the event
577 * Common implementation for event trigger unregistration.
579 * Usually used directly as the @unreg method in event command
580 * implementations.
582 void unregister_trigger(char *glob, struct event_trigger_ops *ops,
583 struct event_trigger_data *test,
584 struct trace_event_file *file)
586 struct event_trigger_data *data;
587 bool unregistered = false;
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);
594 update_cond_flag(file);
595 break;
599 if (unregistered && data->ops->free)
600 data->ops->free(data->ops, data);
604 * event_trigger_callback - Generic event_command @func implementation
605 * @cmd_ops: The command ops, used for trigger registration
606 * @file: The trace_event_file associated with the event
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
611 * Common implementation for event command parsing and trigger
612 * instantiation.
614 * Usually used directly as the @func method in event command
615 * implementations.
617 * Return: 0 on success, errno otherwise
619 static int
620 event_trigger_callback(struct event_command *cmd_ops,
621 struct trace_event_file *file,
622 char *glob, char *cmd, char *param)
624 struct event_trigger_data *trigger_data;
625 struct event_trigger_ops *trigger_ops;
626 char *trigger = NULL;
627 char *number;
628 int ret;
630 /* separate the trigger from the filter (t:n [if filter]) */
631 if (param && isdigit(param[0]))
632 trigger = strsep(&param, " \t");
634 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
636 ret = -ENOMEM;
637 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
638 if (!trigger_data)
639 goto out;
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);
645 INIT_LIST_HEAD(&trigger_data->named_list);
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;
654 if (trigger) {
655 number = strsep(&trigger, ":");
657 ret = -EINVAL;
658 if (!strlen(number))
659 goto out_free;
662 * We use the callback data field (which is a pointer)
663 * as our counter.
665 ret = kstrtoul(number, 0, &trigger_data->count);
666 if (ret)
667 goto out_free;
670 if (!param) /* if param is non-empty, it's supposed to be a filter */
671 goto out_reg;
673 if (!cmd_ops->set_filter)
674 goto out_reg;
676 ret = cmd_ops->set_filter(param, trigger_data, file);
677 if (ret < 0)
678 goto out_free;
680 out_reg:
681 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
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.
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;
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;
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
709 * Common implementation for event command filter parsing and filter
710 * instantiation.
712 * Usually used directly as the @set_filter method in event command
713 * implementations.
715 * Also used to remove a filter (if filter_str = NULL).
717 * Return: 0 on success, errno otherwise
719 int set_trigger_filter(char *filter_str,
720 struct event_trigger_data *trigger_data,
721 struct trace_event_file *file)
723 struct event_trigger_data *data = trigger_data;
724 struct event_filter *filter = NULL, *tmp;
725 int ret = -EINVAL;
726 char *s;
728 if (!filter_str) /* clear the current filter */
729 goto assign;
731 s = strsep(&filter_str, " \t");
733 if (!strlen(s) || strcmp(s, "if") != 0)
734 goto out;
736 if (!filter_str)
737 goto out;
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:
744 tmp = rcu_access_pointer(data->filter);
746 rcu_assign_pointer(data->filter, filter);
748 if (tmp) {
749 /* Make sure the call is done with the filter */
750 synchronize_sched();
751 free_event_filter(tmp);
754 kfree(data->filter_str);
755 data->filter_str = NULL;
757 if (filter_str) {
758 data->filter_str = kstrdup(filter_str, GFP_KERNEL);
759 if (!data->filter_str) {
760 free_event_filter(rcu_access_pointer(data->filter));
761 data->filter = NULL;
762 ret = -ENOMEM;
765 out:
766 return ret;
769 static LIST_HEAD(named_triggers);
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
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.
782 * Return: the common trigger data for the given named trigger on
783 * success, NULL otherwise.
785 struct event_trigger_data *find_named_trigger(const char *name)
787 struct event_trigger_data *data;
789 if (!name)
790 return NULL;
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;
799 return NULL;
803 * is_named_trigger - determine if a given trigger is a named trigger
804 * @test: The trigger data to test
806 * Return: true if 'test' is a named trigger, false otherwise.
808 bool is_named_trigger(struct event_trigger_data *test)
810 struct event_trigger_data *data;
812 list_for_each_entry(data, &named_triggers, named_list) {
813 if (test == data)
814 return true;
817 return false;
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
825 * Return: 0 if successful, negative error otherwise.
827 int save_named_trigger(const char *name, struct event_trigger_data *data)
829 data->name = kstrdup(name, GFP_KERNEL);
830 if (!data->name)
831 return -ENOMEM;
833 list_add(&data->named_list, &named_triggers);
835 return 0;
839 * del_named_trigger - delete a trigger from the named trigger list
840 * @data: The trigger data to delete
842 void del_named_trigger(struct event_trigger_data *data)
844 kfree(data->name);
845 data->name = NULL;
847 list_del(&data->named_list);
850 static void __pause_named_trigger(struct event_trigger_data *data, bool pause)
852 struct event_trigger_data *test;
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;
867 * pause_named_trigger - Pause all named triggers with the same name
868 * @data: The trigger data of a named trigger to pause
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.
875 void pause_named_trigger(struct event_trigger_data *data)
877 __pause_named_trigger(data, true);
881 * unpause_named_trigger - Un-pause all named triggers with the same name
882 * @data: The trigger data of a named trigger to unpause
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.
889 void unpause_named_trigger(struct event_trigger_data *data)
891 __pause_named_trigger(data, false);
895 * set_named_trigger_data - Associate common named trigger data
896 * @data: The trigger data of a named trigger to unpause
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.
905 void set_named_trigger_data(struct event_trigger_data *data,
906 struct event_trigger_data *named_data)
908 data->named_data = named_data;
911 static void
912 traceon_trigger(struct event_trigger_data *data, void *rec)
914 if (tracing_is_on())
915 return;
917 tracing_on();
920 static void
921 traceon_count_trigger(struct event_trigger_data *data, void *rec)
923 if (tracing_is_on())
924 return;
926 if (!data->count)
927 return;
929 if (data->count != -1)
930 (data->count)--;
932 tracing_on();
935 static void
936 traceoff_trigger(struct event_trigger_data *data, void *rec)
938 if (!tracing_is_on())
939 return;
941 tracing_off();
944 static void
945 traceoff_count_trigger(struct event_trigger_data *data, void *rec)
947 if (!tracing_is_on())
948 return;
950 if (!data->count)
951 return;
953 if (data->count != -1)
954 (data->count)--;
956 tracing_off();
959 static int
960 traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
961 struct event_trigger_data *data)
963 return event_trigger_print("traceon", m, (void *)data->count,
964 data->filter_str);
967 static int
968 traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
969 struct event_trigger_data *data)
971 return event_trigger_print("traceoff", m, (void *)data->count,
972 data->filter_str);
975 static 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,
982 static 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,
989 static 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,
996 static 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,
1003 static struct event_trigger_ops *
1004 onoff_get_trigger_ops(char *cmd, char *param)
1006 struct event_trigger_ops *ops;
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;
1016 return ops;
1019 static 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,
1026 .set_filter = set_trigger_filter,
1029 static struct event_command trigger_traceoff_cmd = {
1030 .name = "traceoff",
1031 .trigger_type = ETT_TRACE_ONOFF,
1032 .flags = EVENT_CMD_FL_POST_TRIGGER,
1033 .func = event_trigger_callback,
1034 .reg = register_trigger,
1035 .unreg = unregister_trigger,
1036 .get_trigger_ops = onoff_get_trigger_ops,
1037 .set_filter = set_trigger_filter,
1040 #ifdef CONFIG_TRACER_SNAPSHOT
1041 static void
1042 snapshot_trigger(struct event_trigger_data *data, void *rec)
1044 tracing_snapshot();
1047 static void
1048 snapshot_count_trigger(struct event_trigger_data *data, void *rec)
1050 if (!data->count)
1051 return;
1053 if (data->count != -1)
1054 (data->count)--;
1056 snapshot_trigger(data, rec);
1059 static int
1060 register_snapshot_trigger(char *glob, struct event_trigger_ops *ops,
1061 struct event_trigger_data *data,
1062 struct trace_event_file *file)
1064 int ret = register_trigger(glob, ops, data, file);
1066 if (ret > 0 && tracing_alloc_snapshot() != 0) {
1067 unregister_trigger(glob, ops, data, file);
1068 ret = 0;
1071 return ret;
1074 static int
1075 snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1076 struct event_trigger_data *data)
1078 return event_trigger_print("snapshot", m, (void *)data->count,
1079 data->filter_str);
1082 static 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,
1089 static 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,
1096 static struct event_trigger_ops *
1097 snapshot_get_trigger_ops(char *cmd, char *param)
1099 return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
1102 static 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,
1109 .set_filter = set_trigger_filter,
1112 static __init int register_trigger_snapshot_cmd(void)
1114 int ret;
1116 ret = register_event_command(&trigger_snapshot_cmd);
1117 WARN_ON(ret < 0);
1119 return ret;
1121 #else
1122 static __init int register_trigger_snapshot_cmd(void) { return 0; }
1123 #endif /* CONFIG_TRACER_SNAPSHOT */
1125 #ifdef CONFIG_STACKTRACE
1126 #ifdef CONFIG_UNWINDER_ORC
1127 /* Skip 2:
1128 * event_triggers_post_call()
1129 * trace_event_raw_event_xxx()
1131 # define STACK_SKIP 2
1132 #else
1134 * Skip 4:
1135 * stacktrace_trigger()
1136 * event_triggers_post_call()
1137 * trace_event_buffer_commit()
1138 * trace_event_raw_event_xxx()
1140 #define STACK_SKIP 4
1141 #endif
1143 static void
1144 stacktrace_trigger(struct event_trigger_data *data, void *rec)
1146 trace_dump_stack(STACK_SKIP);
1149 static void
1150 stacktrace_count_trigger(struct event_trigger_data *data, void *rec)
1152 if (!data->count)
1153 return;
1155 if (data->count != -1)
1156 (data->count)--;
1158 stacktrace_trigger(data, rec);
1161 static int
1162 stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1163 struct event_trigger_data *data)
1165 return event_trigger_print("stacktrace", m, (void *)data->count,
1166 data->filter_str);
1169 static struct event_trigger_ops stacktrace_trigger_ops = {
1170 .func = stacktrace_trigger,
1171 .print = stacktrace_trigger_print,
1172 .init = event_trigger_init,
1173 .free = event_trigger_free,
1176 static struct event_trigger_ops stacktrace_count_trigger_ops = {
1177 .func = stacktrace_count_trigger,
1178 .print = stacktrace_trigger_print,
1179 .init = event_trigger_init,
1180 .free = event_trigger_free,
1183 static struct event_trigger_ops *
1184 stacktrace_get_trigger_ops(char *cmd, char *param)
1186 return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
1189 static struct event_command trigger_stacktrace_cmd = {
1190 .name = "stacktrace",
1191 .trigger_type = ETT_STACKTRACE,
1192 .flags = EVENT_CMD_FL_POST_TRIGGER,
1193 .func = event_trigger_callback,
1194 .reg = register_trigger,
1195 .unreg = unregister_trigger,
1196 .get_trigger_ops = stacktrace_get_trigger_ops,
1197 .set_filter = set_trigger_filter,
1200 static __init int register_trigger_stacktrace_cmd(void)
1202 int ret;
1204 ret = register_event_command(&trigger_stacktrace_cmd);
1205 WARN_ON(ret < 0);
1207 return ret;
1209 #else
1210 static __init int register_trigger_stacktrace_cmd(void) { return 0; }
1211 #endif /* CONFIG_STACKTRACE */
1213 static __init void unregister_trigger_traceon_traceoff_cmds(void)
1215 unregister_event_command(&trigger_traceon_cmd);
1216 unregister_event_command(&trigger_traceoff_cmd);
1219 static void
1220 event_enable_trigger(struct event_trigger_data *data, void *rec)
1222 struct enable_trigger_data *enable_data = data->private_data;
1224 if (enable_data->enable)
1225 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1226 else
1227 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1230 static void
1231 event_enable_count_trigger(struct event_trigger_data *data, void *rec)
1233 struct enable_trigger_data *enable_data = data->private_data;
1235 if (!data->count)
1236 return;
1238 /* Skip if the event is in a state we want to switch to */
1239 if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
1240 return;
1242 if (data->count != -1)
1243 (data->count)--;
1245 event_enable_trigger(data, rec);
1248 int event_enable_trigger_print(struct seq_file *m,
1249 struct event_trigger_ops *ops,
1250 struct event_trigger_data *data)
1252 struct enable_trigger_data *enable_data = data->private_data;
1254 seq_printf(m, "%s:%s:%s",
1255 enable_data->hist ?
1256 (enable_data->enable ? ENABLE_HIST_STR : DISABLE_HIST_STR) :
1257 (enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR),
1258 enable_data->file->event_call->class->system,
1259 trace_event_name(enable_data->file->event_call));
1261 if (data->count == -1)
1262 seq_puts(m, ":unlimited");
1263 else
1264 seq_printf(m, ":count=%ld", data->count);
1266 if (data->filter_str)
1267 seq_printf(m, " if %s\n", data->filter_str);
1268 else
1269 seq_putc(m, '\n');
1271 return 0;
1274 void event_enable_trigger_free(struct event_trigger_ops *ops,
1275 struct event_trigger_data *data)
1277 struct enable_trigger_data *enable_data = data->private_data;
1279 if (WARN_ON_ONCE(data->ref <= 0))
1280 return;
1282 data->ref--;
1283 if (!data->ref) {
1284 /* Remove the SOFT_MODE flag */
1285 trace_event_enable_disable(enable_data->file, 0, 1);
1286 module_put(enable_data->file->event_call->mod);
1287 trigger_data_free(data);
1288 kfree(enable_data);
1292 static struct event_trigger_ops event_enable_trigger_ops = {
1293 .func = event_enable_trigger,
1294 .print = event_enable_trigger_print,
1295 .init = event_trigger_init,
1296 .free = event_enable_trigger_free,
1299 static struct event_trigger_ops event_enable_count_trigger_ops = {
1300 .func = event_enable_count_trigger,
1301 .print = event_enable_trigger_print,
1302 .init = event_trigger_init,
1303 .free = event_enable_trigger_free,
1306 static struct event_trigger_ops event_disable_trigger_ops = {
1307 .func = event_enable_trigger,
1308 .print = event_enable_trigger_print,
1309 .init = event_trigger_init,
1310 .free = event_enable_trigger_free,
1313 static struct event_trigger_ops event_disable_count_trigger_ops = {
1314 .func = event_enable_count_trigger,
1315 .print = event_enable_trigger_print,
1316 .init = event_trigger_init,
1317 .free = event_enable_trigger_free,
1320 int event_enable_trigger_func(struct event_command *cmd_ops,
1321 struct trace_event_file *file,
1322 char *glob, char *cmd, char *param)
1324 struct trace_event_file *event_enable_file;
1325 struct enable_trigger_data *enable_data;
1326 struct event_trigger_data *trigger_data;
1327 struct event_trigger_ops *trigger_ops;
1328 struct trace_array *tr = file->tr;
1329 const char *system;
1330 const char *event;
1331 bool hist = false;
1332 char *trigger;
1333 char *number;
1334 bool enable;
1335 int ret;
1337 if (!param)
1338 return -EINVAL;
1340 /* separate the trigger from the filter (s:e:n [if filter]) */
1341 trigger = strsep(&param, " \t");
1342 if (!trigger)
1343 return -EINVAL;
1345 system = strsep(&trigger, ":");
1346 if (!trigger)
1347 return -EINVAL;
1349 event = strsep(&trigger, ":");
1351 ret = -EINVAL;
1352 event_enable_file = find_event_file(tr, system, event);
1353 if (!event_enable_file)
1354 goto out;
1356 #ifdef CONFIG_HIST_TRIGGERS
1357 hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) ||
1358 (strcmp(cmd, DISABLE_HIST_STR) == 0));
1360 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1361 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1362 #else
1363 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1364 #endif
1365 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
1367 ret = -ENOMEM;
1368 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
1369 if (!trigger_data)
1370 goto out;
1372 enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
1373 if (!enable_data) {
1374 kfree(trigger_data);
1375 goto out;
1378 trigger_data->count = -1;
1379 trigger_data->ops = trigger_ops;
1380 trigger_data->cmd_ops = cmd_ops;
1381 INIT_LIST_HEAD(&trigger_data->list);
1382 RCU_INIT_POINTER(trigger_data->filter, NULL);
1384 enable_data->hist = hist;
1385 enable_data->enable = enable;
1386 enable_data->file = event_enable_file;
1387 trigger_data->private_data = enable_data;
1389 if (glob[0] == '!') {
1390 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
1391 kfree(trigger_data);
1392 kfree(enable_data);
1393 ret = 0;
1394 goto out;
1397 if (trigger) {
1398 number = strsep(&trigger, ":");
1400 ret = -EINVAL;
1401 if (!strlen(number))
1402 goto out_free;
1405 * We use the callback data field (which is a pointer)
1406 * as our counter.
1408 ret = kstrtoul(number, 0, &trigger_data->count);
1409 if (ret)
1410 goto out_free;
1413 if (!param) /* if param is non-empty, it's supposed to be a filter */
1414 goto out_reg;
1416 if (!cmd_ops->set_filter)
1417 goto out_reg;
1419 ret = cmd_ops->set_filter(param, trigger_data, file);
1420 if (ret < 0)
1421 goto out_free;
1423 out_reg:
1424 /* Don't let event modules unload while probe registered */
1425 ret = try_module_get(event_enable_file->event_call->mod);
1426 if (!ret) {
1427 ret = -EBUSY;
1428 goto out_free;
1431 ret = trace_event_enable_disable(event_enable_file, 1, 1);
1432 if (ret < 0)
1433 goto out_put;
1434 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1436 * The above returns on success the # of functions enabled,
1437 * but if it didn't find any functions it returns zero.
1438 * Consider no functions a failure too.
1440 if (!ret) {
1441 ret = -ENOENT;
1442 goto out_disable;
1443 } else if (ret < 0)
1444 goto out_disable;
1445 /* Just return zero, not the number of enabled functions */
1446 ret = 0;
1447 out:
1448 return ret;
1450 out_disable:
1451 trace_event_enable_disable(event_enable_file, 0, 1);
1452 out_put:
1453 module_put(event_enable_file->event_call->mod);
1454 out_free:
1455 if (cmd_ops->set_filter)
1456 cmd_ops->set_filter(NULL, trigger_data, NULL);
1457 kfree(trigger_data);
1458 kfree(enable_data);
1459 goto out;
1462 int event_enable_register_trigger(char *glob,
1463 struct event_trigger_ops *ops,
1464 struct event_trigger_data *data,
1465 struct trace_event_file *file)
1467 struct enable_trigger_data *enable_data = data->private_data;
1468 struct enable_trigger_data *test_enable_data;
1469 struct event_trigger_data *test;
1470 int ret = 0;
1472 list_for_each_entry_rcu(test, &file->triggers, list) {
1473 test_enable_data = test->private_data;
1474 if (test_enable_data &&
1475 (test->cmd_ops->trigger_type ==
1476 data->cmd_ops->trigger_type) &&
1477 (test_enable_data->file == enable_data->file)) {
1478 ret = -EEXIST;
1479 goto out;
1483 if (data->ops->init) {
1484 ret = data->ops->init(data->ops, data);
1485 if (ret < 0)
1486 goto out;
1489 list_add_rcu(&data->list, &file->triggers);
1490 ret++;
1492 update_cond_flag(file);
1493 if (trace_event_trigger_enable_disable(file, 1) < 0) {
1494 list_del_rcu(&data->list);
1495 update_cond_flag(file);
1496 ret--;
1498 out:
1499 return ret;
1502 void event_enable_unregister_trigger(char *glob,
1503 struct event_trigger_ops *ops,
1504 struct event_trigger_data *test,
1505 struct trace_event_file *file)
1507 struct enable_trigger_data *test_enable_data = test->private_data;
1508 struct enable_trigger_data *enable_data;
1509 struct event_trigger_data *data;
1510 bool unregistered = false;
1512 list_for_each_entry_rcu(data, &file->triggers, list) {
1513 enable_data = data->private_data;
1514 if (enable_data &&
1515 (data->cmd_ops->trigger_type ==
1516 test->cmd_ops->trigger_type) &&
1517 (enable_data->file == test_enable_data->file)) {
1518 unregistered = true;
1519 list_del_rcu(&data->list);
1520 trace_event_trigger_enable_disable(file, 0);
1521 update_cond_flag(file);
1522 break;
1526 if (unregistered && data->ops->free)
1527 data->ops->free(data->ops, data);
1530 static struct event_trigger_ops *
1531 event_enable_get_trigger_ops(char *cmd, char *param)
1533 struct event_trigger_ops *ops;
1534 bool enable;
1536 #ifdef CONFIG_HIST_TRIGGERS
1537 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1538 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1539 #else
1540 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1541 #endif
1542 if (enable)
1543 ops = param ? &event_enable_count_trigger_ops :
1544 &event_enable_trigger_ops;
1545 else
1546 ops = param ? &event_disable_count_trigger_ops :
1547 &event_disable_trigger_ops;
1549 return ops;
1552 static struct event_command trigger_enable_cmd = {
1553 .name = ENABLE_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,
1562 static struct event_command trigger_disable_cmd = {
1563 .name = DISABLE_EVENT_STR,
1564 .trigger_type = ETT_EVENT_ENABLE,
1565 .func = event_enable_trigger_func,
1566 .reg = event_enable_register_trigger,
1567 .unreg = event_enable_unregister_trigger,
1568 .get_trigger_ops = event_enable_get_trigger_ops,
1569 .set_filter = set_trigger_filter,
1572 static __init void unregister_trigger_enable_disable_cmds(void)
1574 unregister_event_command(&trigger_enable_cmd);
1575 unregister_event_command(&trigger_disable_cmd);
1578 static __init int register_trigger_enable_disable_cmds(void)
1580 int ret;
1582 ret = register_event_command(&trigger_enable_cmd);
1583 if (WARN_ON(ret < 0))
1584 return ret;
1585 ret = register_event_command(&trigger_disable_cmd);
1586 if (WARN_ON(ret < 0))
1587 unregister_trigger_enable_disable_cmds();
1589 return ret;
1592 static __init int register_trigger_traceon_traceoff_cmds(void)
1594 int ret;
1596 ret = register_event_command(&trigger_traceon_cmd);
1597 if (WARN_ON(ret < 0))
1598 return ret;
1599 ret = register_event_command(&trigger_traceoff_cmd);
1600 if (WARN_ON(ret < 0))
1601 unregister_trigger_traceon_traceoff_cmds();
1603 return ret;
1606 __init int register_trigger_cmds(void)
1608 register_trigger_traceon_traceoff_cmds();
1609 register_trigger_snapshot_cmd();
1610 register_trigger_stacktrace_cmd();
1611 register_trigger_enable_disable_cmds();
1612 register_trigger_hist_enable_disable_cmds();
1613 register_trigger_hist_cmd();
1615 return 0;