1 // SPDX-License-Identifier: GPL-2.0
3 * trace_events_trigger - trace event triggers
5 * Copyright (C) 2013 Tom Zanussi <tom.zanussi@linux.intel.com>
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>
17 static LIST_HEAD(trigger_commands);
18 static DEFINE_MUTEX(trigger_cmd_mutex);
20 void trigger_data_free(struct event_trigger_data *data)
22 if (data->cmd_ops->set_filter)
23 data->cmd_ops->set_filter(NULL, data, NULL);
25 /* make sure current triggers exit before free */
26 tracepoint_synchronize_unregister();
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
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.
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.
50 * Called from tracepoint handlers (with rcu_read_lock_sched() held).
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.
55 enum event_trigger_type
56 event_triggers_call(struct trace_event_file *file, void *rec,
57 struct ring_buffer_event *event)
59 struct event_trigger_data *data;
60 enum event_trigger_type tt = ETT_NONE;
61 struct event_filter *filter;
63 if (list_empty(&file->triggers))
66 list_for_each_entry_rcu(data, &file->triggers, list) {
70 data->ops->func(data, rec, event);
73 filter = rcu_dereference_sched(data->filter);
74 if (filter && !filter_match_preds(filter, rec))
76 if (event_command_post_trigger(data->cmd_ops)) {
77 tt |= data->cmd_ops->trigger_type;
80 data->ops->func(data, rec, event);
84 EXPORT_SYMBOL_GPL(event_triggers_call);
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
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.
96 * Called from tracepoint handlers (with rcu_read_lock_sched() held).
99 event_triggers_post_call(struct trace_event_file *file,
100 enum event_trigger_type tt)
102 struct event_trigger_data *data;
104 list_for_each_entry_rcu(data, &file->triggers, list) {
107 if (data->cmd_ops->trigger_type & tt)
108 data->ops->func(data, NULL, NULL);
111 EXPORT_SYMBOL_GPL(event_triggers_post_call);
113 #define SHOW_AVAILABLE_TRIGGERS (void *)(1UL)
115 static void *trigger_next(struct seq_file *m, void *t, loff_t *pos)
117 struct trace_event_file *event_file = event_file_data(m->private);
119 if (t == SHOW_AVAILABLE_TRIGGERS) {
123 return seq_list_next(t, &event_file->triggers, pos);
126 static void *trigger_start(struct seq_file *m, loff_t *pos)
128 struct trace_event_file *event_file;
130 /* ->stop() is called even if ->start() fails */
131 mutex_lock(&event_mutex);
132 event_file = event_file_data(m->private);
133 if (unlikely(!event_file))
134 return ERR_PTR(-ENODEV);
136 if (list_empty(&event_file->triggers))
137 return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL;
139 return seq_list_start(&event_file->triggers, *pos);
142 static void trigger_stop(struct seq_file *m, void *t)
144 mutex_unlock(&event_mutex);
147 static int trigger_show(struct seq_file *m, void *v)
149 struct event_trigger_data *data;
150 struct event_command *p;
152 if (v == SHOW_AVAILABLE_TRIGGERS) {
153 seq_puts(m, "# Available triggers:\n");
155 mutex_lock(&trigger_cmd_mutex);
156 list_for_each_entry_reverse(p, &trigger_commands, list)
157 seq_printf(m, " %s", p->name);
159 mutex_unlock(&trigger_cmd_mutex);
163 data = list_entry(v, struct event_trigger_data, list);
164 data->ops->print(m, data->ops, data);
169 static const struct seq_operations event_triggers_seq_ops = {
170 .start = trigger_start,
171 .next = trigger_next,
172 .stop = trigger_stop,
173 .show = trigger_show,
176 static int event_trigger_regex_open(struct inode *inode, struct file *file)
180 ret = security_locked_down(LOCKDOWN_TRACEFS);
184 mutex_lock(&event_mutex);
186 if (unlikely(!event_file_data(file))) {
187 mutex_unlock(&event_mutex);
191 if ((file->f_mode & FMODE_WRITE) &&
192 (file->f_flags & O_TRUNC)) {
193 struct trace_event_file *event_file;
194 struct event_command *p;
196 event_file = event_file_data(file);
198 list_for_each_entry(p, &trigger_commands, list) {
200 p->unreg_all(event_file);
204 if (file->f_mode & FMODE_READ) {
205 ret = seq_open(file, &event_triggers_seq_ops);
207 struct seq_file *m = file->private_data;
212 mutex_unlock(&event_mutex);
217 int trigger_process_regex(struct trace_event_file *file, char *buff)
219 char *command, *next = buff;
220 struct event_command *p;
223 command = strsep(&next, ": \t");
224 command = (command[0] != '!') ? command : command + 1;
226 mutex_lock(&trigger_cmd_mutex);
227 list_for_each_entry(p, &trigger_commands, list) {
228 if (strcmp(p->name, command) == 0) {
229 ret = p->func(p, file, buff, command, next);
234 mutex_unlock(&trigger_cmd_mutex);
239 static ssize_t event_trigger_regex_write(struct file *file,
240 const char __user *ubuf,
241 size_t cnt, loff_t *ppos)
243 struct trace_event_file *event_file;
250 if (cnt >= PAGE_SIZE)
253 buf = memdup_user_nul(ubuf, cnt);
259 mutex_lock(&event_mutex);
260 event_file = event_file_data(file);
261 if (unlikely(!event_file)) {
262 mutex_unlock(&event_mutex);
266 ret = trigger_process_regex(event_file, buf);
267 mutex_unlock(&event_mutex);
279 static int event_trigger_regex_release(struct inode *inode, struct file *file)
281 mutex_lock(&event_mutex);
283 if (file->f_mode & FMODE_READ)
284 seq_release(inode, file);
286 mutex_unlock(&event_mutex);
292 event_trigger_write(struct file *filp, const char __user *ubuf,
293 size_t cnt, loff_t *ppos)
295 return event_trigger_regex_write(filp, ubuf, cnt, ppos);
299 event_trigger_open(struct inode *inode, struct file *filp)
301 /* Checks for tracefs lockdown */
302 return event_trigger_regex_open(inode, filp);
306 event_trigger_release(struct inode *inode, struct file *file)
308 return event_trigger_regex_release(inode, file);
311 const struct file_operations event_trigger_fops = {
312 .open = event_trigger_open,
314 .write = event_trigger_write,
315 .llseek = tracing_lseek,
316 .release = event_trigger_release,
320 * Currently we only register event commands from __init, so mark this
323 __init int register_event_command(struct event_command *cmd)
325 struct event_command *p;
328 mutex_lock(&trigger_cmd_mutex);
329 list_for_each_entry(p, &trigger_commands, list) {
330 if (strcmp(cmd->name, p->name) == 0) {
335 list_add(&cmd->list, &trigger_commands);
337 mutex_unlock(&trigger_cmd_mutex);
343 * Currently we only unregister event commands from __init, so mark
346 __init int unregister_event_command(struct event_command *cmd)
348 struct event_command *p, *n;
351 mutex_lock(&trigger_cmd_mutex);
352 list_for_each_entry_safe(p, n, &trigger_commands, list) {
353 if (strcmp(cmd->name, p->name) == 0) {
355 list_del_init(&p->list);
360 mutex_unlock(&trigger_cmd_mutex);
366 * event_trigger_print - Generic event_trigger_ops @print implementation
367 * @name: The name of the event trigger
368 * @m: The seq_file being printed to
369 * @data: Trigger-specific data
370 * @filter_str: filter_str to print, if present
372 * Common implementation for event triggers to print themselves.
374 * Usually wrapped by a function that simply sets the @name of the
375 * trigger command and then invokes this.
377 * Return: 0 on success, errno otherwise
380 event_trigger_print(const char *name, struct seq_file *m,
381 void *data, char *filter_str)
383 long count = (long)data;
388 seq_puts(m, ":unlimited");
390 seq_printf(m, ":count=%ld", count);
393 seq_printf(m, " if %s\n", filter_str);
401 * event_trigger_init - Generic event_trigger_ops @init implementation
402 * @ops: The trigger ops associated with the trigger
403 * @data: Trigger-specific data
405 * Common implementation of event trigger initialization.
407 * Usually used directly as the @init method in event trigger
410 * Return: 0 on success, errno otherwise
412 int event_trigger_init(struct event_trigger_ops *ops,
413 struct event_trigger_data *data)
420 * event_trigger_free - Generic event_trigger_ops @free implementation
421 * @ops: The trigger ops associated with the trigger
422 * @data: Trigger-specific data
424 * Common implementation of event trigger de-initialization.
426 * Usually used directly as the @free method in event trigger
430 event_trigger_free(struct event_trigger_ops *ops,
431 struct event_trigger_data *data)
433 if (WARN_ON_ONCE(data->ref <= 0))
438 trigger_data_free(data);
441 int trace_event_trigger_enable_disable(struct trace_event_file *file,
446 if (trigger_enable) {
447 if (atomic_inc_return(&file->tm_ref) > 1)
449 set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
450 ret = trace_event_enable_disable(file, 1, 1);
452 if (atomic_dec_return(&file->tm_ref) > 0)
454 clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
455 ret = trace_event_enable_disable(file, 0, 1);
462 * clear_event_triggers - Clear all triggers associated with a trace array
463 * @tr: The trace array to clear
465 * For each trigger, the triggering event has its tm_ref decremented
466 * via trace_event_trigger_enable_disable(), and any associated event
467 * (in the case of enable/disable_event triggers) will have its sm_ref
468 * decremented via free()->trace_event_enable_disable(). That
469 * combination effectively reverses the soft-mode/trigger state added
470 * by trigger registration.
472 * Must be called with event_mutex held.
475 clear_event_triggers(struct trace_array *tr)
477 struct trace_event_file *file;
479 list_for_each_entry(file, &tr->events, list) {
480 struct event_trigger_data *data, *n;
481 list_for_each_entry_safe(data, n, &file->triggers, list) {
482 trace_event_trigger_enable_disable(file, 0);
483 list_del_rcu(&data->list);
485 data->ops->free(data->ops, data);
491 * update_cond_flag - Set or reset the TRIGGER_COND bit
492 * @file: The trace_event_file associated with the event
494 * If an event has triggers and any of those triggers has a filter or
495 * a post_trigger, trigger invocation needs to be deferred until after
496 * the current event has logged its data, and the event should have
497 * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be
500 void update_cond_flag(struct trace_event_file *file)
502 struct event_trigger_data *data;
503 bool set_cond = false;
505 lockdep_assert_held(&event_mutex);
507 list_for_each_entry(data, &file->triggers, list) {
508 if (data->filter || event_command_post_trigger(data->cmd_ops) ||
509 event_command_needs_rec(data->cmd_ops)) {
516 set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
518 clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
522 * register_trigger - Generic event_command @reg implementation
523 * @glob: The raw string used to register the trigger
524 * @ops: The trigger ops associated with the trigger
525 * @data: Trigger-specific data to associate with the trigger
526 * @file: The trace_event_file associated with the event
528 * Common implementation for event trigger registration.
530 * Usually used directly as the @reg method in event command
533 * Return: 0 on success, errno otherwise
535 static int register_trigger(char *glob, struct event_trigger_ops *ops,
536 struct event_trigger_data *data,
537 struct trace_event_file *file)
539 struct event_trigger_data *test;
542 lockdep_assert_held(&event_mutex);
544 list_for_each_entry(test, &file->triggers, list) {
545 if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) {
551 if (data->ops->init) {
552 ret = data->ops->init(data->ops, data);
557 list_add_rcu(&data->list, &file->triggers);
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);
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
582 static 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 lockdep_assert_held(&event_mutex);
591 list_for_each_entry(data, &file->triggers, list) {
592 if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
594 list_del_rcu(&data->list);
595 trace_event_trigger_enable_disable(file, 0);
596 update_cond_flag(file);
601 if (unregistered && data->ops->free)
602 data->ops->free(data->ops, data);
606 * event_trigger_callback - Generic event_command @func implementation
607 * @cmd_ops: The command ops, used for trigger registration
608 * @file: The trace_event_file associated with the event
609 * @glob: The raw string used to register the trigger
610 * @cmd: The cmd portion of the string used to register the trigger
611 * @param: The params portion of the string used to register the trigger
613 * Common implementation for event command parsing and trigger
616 * Usually used directly as the @func method in event command
619 * Return: 0 on success, errno otherwise
622 event_trigger_callback(struct event_command *cmd_ops,
623 struct trace_event_file *file,
624 char *glob, char *cmd, char *param)
626 struct event_trigger_data *trigger_data;
627 struct event_trigger_ops *trigger_ops;
628 char *trigger = NULL;
632 /* separate the trigger from the filter (t:n [if filter]) */
633 if (param && isdigit(param[0]))
634 trigger = strsep(¶m, " \t");
636 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
639 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
643 trigger_data->count = -1;
644 trigger_data->ops = trigger_ops;
645 trigger_data->cmd_ops = cmd_ops;
646 trigger_data->private_data = file;
647 INIT_LIST_HEAD(&trigger_data->list);
648 INIT_LIST_HEAD(&trigger_data->named_list);
650 if (glob[0] == '!') {
651 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
658 number = strsep(&trigger, ":");
665 * We use the callback data field (which is a pointer)
668 ret = kstrtoul(number, 0, &trigger_data->count);
673 if (!param) /* if param is non-empty, it's supposed to be a filter */
676 if (!cmd_ops->set_filter)
679 ret = cmd_ops->set_filter(param, trigger_data, file);
684 /* Up the trigger_data count to make sure reg doesn't free it on failure */
685 event_trigger_init(trigger_ops, trigger_data);
686 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
688 * The above returns on success the # of functions enabled,
689 * but if it didn't find any functions it returns zero.
690 * Consider no functions a failure too.
693 cmd_ops->unreg(glob, trigger_ops, trigger_data, file);
698 /* Down the counter of trigger_data or free it if not used anymore */
699 event_trigger_free(trigger_ops, trigger_data);
704 if (cmd_ops->set_filter)
705 cmd_ops->set_filter(NULL, trigger_data, NULL);
711 * set_trigger_filter - Generic event_command @set_filter implementation
712 * @filter_str: The filter string for the trigger, NULL to remove filter
713 * @trigger_data: Trigger-specific data
714 * @file: The trace_event_file associated with the event
716 * Common implementation for event command filter parsing and filter
719 * Usually used directly as the @set_filter method in event command
722 * Also used to remove a filter (if filter_str = NULL).
724 * Return: 0 on success, errno otherwise
726 int set_trigger_filter(char *filter_str,
727 struct event_trigger_data *trigger_data,
728 struct trace_event_file *file)
730 struct event_trigger_data *data = trigger_data;
731 struct event_filter *filter = NULL, *tmp;
735 if (!filter_str) /* clear the current filter */
738 s = strsep(&filter_str, " \t");
740 if (!strlen(s) || strcmp(s, "if") != 0)
746 /* The filter is for the 'trigger' event, not the triggered event */
747 ret = create_event_filter(file->tr, file->event_call,
748 filter_str, false, &filter);
750 * If create_event_filter() fails, filter still needs to be freed.
751 * Which the calling code will do with data->filter.
754 tmp = rcu_access_pointer(data->filter);
756 rcu_assign_pointer(data->filter, filter);
759 /* Make sure the call is done with the filter */
760 tracepoint_synchronize_unregister();
761 free_event_filter(tmp);
764 kfree(data->filter_str);
765 data->filter_str = NULL;
768 data->filter_str = kstrdup(filter_str, GFP_KERNEL);
769 if (!data->filter_str) {
770 free_event_filter(rcu_access_pointer(data->filter));
779 static LIST_HEAD(named_triggers);
782 * find_named_trigger - Find the common named trigger associated with @name
783 * @name: The name of the set of named triggers to find the common data for
785 * Named triggers are sets of triggers that share a common set of
786 * trigger data. The first named trigger registered with a given name
787 * owns the common trigger data that the others subsequently
788 * registered with the same name will reference. This function
789 * returns the common trigger data associated with that first
790 * registered instance.
792 * Return: the common trigger data for the given named trigger on
793 * success, NULL otherwise.
795 struct event_trigger_data *find_named_trigger(const char *name)
797 struct event_trigger_data *data;
802 list_for_each_entry(data, &named_triggers, named_list) {
803 if (data->named_data)
805 if (strcmp(data->name, name) == 0)
813 * is_named_trigger - determine if a given trigger is a named trigger
814 * @test: The trigger data to test
816 * Return: true if 'test' is a named trigger, false otherwise.
818 bool is_named_trigger(struct event_trigger_data *test)
820 struct event_trigger_data *data;
822 list_for_each_entry(data, &named_triggers, named_list) {
831 * save_named_trigger - save the trigger in the named trigger list
832 * @name: The name of the named trigger set
833 * @data: The trigger data to save
835 * Return: 0 if successful, negative error otherwise.
837 int save_named_trigger(const char *name, struct event_trigger_data *data)
839 data->name = kstrdup(name, GFP_KERNEL);
843 list_add(&data->named_list, &named_triggers);
849 * del_named_trigger - delete a trigger from the named trigger list
850 * @data: The trigger data to delete
852 void del_named_trigger(struct event_trigger_data *data)
857 list_del(&data->named_list);
860 static void __pause_named_trigger(struct event_trigger_data *data, bool pause)
862 struct event_trigger_data *test;
864 list_for_each_entry(test, &named_triggers, named_list) {
865 if (strcmp(test->name, data->name) == 0) {
867 test->paused_tmp = test->paused;
870 test->paused = test->paused_tmp;
877 * pause_named_trigger - Pause all named triggers with the same name
878 * @data: The trigger data of a named trigger to pause
880 * Pauses a named trigger along with all other triggers having the
881 * same name. Because named triggers share a common set of data,
882 * pausing only one is meaningless, so pausing one named trigger needs
883 * to pause all triggers with the same name.
885 void pause_named_trigger(struct event_trigger_data *data)
887 __pause_named_trigger(data, true);
891 * unpause_named_trigger - Un-pause all named triggers with the same name
892 * @data: The trigger data of a named trigger to unpause
894 * Un-pauses a named trigger along with all other triggers having the
895 * same name. Because named triggers share a common set of data,
896 * unpausing only one is meaningless, so unpausing one named trigger
897 * needs to unpause all triggers with the same name.
899 void unpause_named_trigger(struct event_trigger_data *data)
901 __pause_named_trigger(data, false);
905 * set_named_trigger_data - Associate common named trigger data
906 * @data: The trigger data of a named trigger to unpause
908 * Named triggers are sets of triggers that share a common set of
909 * trigger data. The first named trigger registered with a given name
910 * owns the common trigger data that the others subsequently
911 * registered with the same name will reference. This function
912 * associates the common trigger data from the first trigger with the
915 void set_named_trigger_data(struct event_trigger_data *data,
916 struct event_trigger_data *named_data)
918 data->named_data = named_data;
921 struct event_trigger_data *
922 get_named_trigger_data(struct event_trigger_data *data)
924 return data->named_data;
928 traceon_trigger(struct event_trigger_data *data, void *rec,
929 struct ring_buffer_event *event)
938 traceon_count_trigger(struct event_trigger_data *data, void *rec,
939 struct ring_buffer_event *event)
947 if (data->count != -1)
954 traceoff_trigger(struct event_trigger_data *data, void *rec,
955 struct ring_buffer_event *event)
957 if (!tracing_is_on())
964 traceoff_count_trigger(struct event_trigger_data *data, void *rec,
965 struct ring_buffer_event *event)
967 if (!tracing_is_on())
973 if (data->count != -1)
980 traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
981 struct event_trigger_data *data)
983 return event_trigger_print("traceon", m, (void *)data->count,
988 traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
989 struct event_trigger_data *data)
991 return event_trigger_print("traceoff", m, (void *)data->count,
995 static struct event_trigger_ops traceon_trigger_ops = {
996 .func = traceon_trigger,
997 .print = traceon_trigger_print,
998 .init = event_trigger_init,
999 .free = event_trigger_free,
1002 static struct event_trigger_ops traceon_count_trigger_ops = {
1003 .func = traceon_count_trigger,
1004 .print = traceon_trigger_print,
1005 .init = event_trigger_init,
1006 .free = event_trigger_free,
1009 static struct event_trigger_ops traceoff_trigger_ops = {
1010 .func = traceoff_trigger,
1011 .print = traceoff_trigger_print,
1012 .init = event_trigger_init,
1013 .free = event_trigger_free,
1016 static struct event_trigger_ops traceoff_count_trigger_ops = {
1017 .func = traceoff_count_trigger,
1018 .print = traceoff_trigger_print,
1019 .init = event_trigger_init,
1020 .free = event_trigger_free,
1023 static struct event_trigger_ops *
1024 onoff_get_trigger_ops(char *cmd, char *param)
1026 struct event_trigger_ops *ops;
1028 /* we register both traceon and traceoff to this callback */
1029 if (strcmp(cmd, "traceon") == 0)
1030 ops = param ? &traceon_count_trigger_ops :
1031 &traceon_trigger_ops;
1033 ops = param ? &traceoff_count_trigger_ops :
1034 &traceoff_trigger_ops;
1039 static struct event_command trigger_traceon_cmd = {
1041 .trigger_type = ETT_TRACE_ONOFF,
1042 .func = event_trigger_callback,
1043 .reg = register_trigger,
1044 .unreg = unregister_trigger,
1045 .get_trigger_ops = onoff_get_trigger_ops,
1046 .set_filter = set_trigger_filter,
1049 static struct event_command trigger_traceoff_cmd = {
1051 .trigger_type = ETT_TRACE_ONOFF,
1052 .flags = EVENT_CMD_FL_POST_TRIGGER,
1053 .func = event_trigger_callback,
1054 .reg = register_trigger,
1055 .unreg = unregister_trigger,
1056 .get_trigger_ops = onoff_get_trigger_ops,
1057 .set_filter = set_trigger_filter,
1060 #ifdef CONFIG_TRACER_SNAPSHOT
1062 snapshot_trigger(struct event_trigger_data *data, void *rec,
1063 struct ring_buffer_event *event)
1065 struct trace_event_file *file = data->private_data;
1068 tracing_snapshot_instance(file->tr);
1074 snapshot_count_trigger(struct event_trigger_data *data, void *rec,
1075 struct ring_buffer_event *event)
1080 if (data->count != -1)
1083 snapshot_trigger(data, rec, event);
1087 register_snapshot_trigger(char *glob, struct event_trigger_ops *ops,
1088 struct event_trigger_data *data,
1089 struct trace_event_file *file)
1091 if (tracing_alloc_snapshot_instance(file->tr) != 0)
1094 return register_trigger(glob, ops, data, file);
1098 snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1099 struct event_trigger_data *data)
1101 return event_trigger_print("snapshot", m, (void *)data->count,
1105 static struct event_trigger_ops snapshot_trigger_ops = {
1106 .func = snapshot_trigger,
1107 .print = snapshot_trigger_print,
1108 .init = event_trigger_init,
1109 .free = event_trigger_free,
1112 static struct event_trigger_ops snapshot_count_trigger_ops = {
1113 .func = snapshot_count_trigger,
1114 .print = snapshot_trigger_print,
1115 .init = event_trigger_init,
1116 .free = event_trigger_free,
1119 static struct event_trigger_ops *
1120 snapshot_get_trigger_ops(char *cmd, char *param)
1122 return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
1125 static struct event_command trigger_snapshot_cmd = {
1127 .trigger_type = ETT_SNAPSHOT,
1128 .func = event_trigger_callback,
1129 .reg = register_snapshot_trigger,
1130 .unreg = unregister_trigger,
1131 .get_trigger_ops = snapshot_get_trigger_ops,
1132 .set_filter = set_trigger_filter,
1135 static __init int register_trigger_snapshot_cmd(void)
1139 ret = register_event_command(&trigger_snapshot_cmd);
1145 static __init int register_trigger_snapshot_cmd(void) { return 0; }
1146 #endif /* CONFIG_TRACER_SNAPSHOT */
1148 #ifdef CONFIG_STACKTRACE
1149 #ifdef CONFIG_UNWINDER_ORC
1151 * event_triggers_post_call()
1152 * trace_event_raw_event_xxx()
1154 # define STACK_SKIP 2
1158 * stacktrace_trigger()
1159 * event_triggers_post_call()
1160 * trace_event_buffer_commit()
1161 * trace_event_raw_event_xxx()
1163 #define STACK_SKIP 4
1167 stacktrace_trigger(struct event_trigger_data *data, void *rec,
1168 struct ring_buffer_event *event)
1170 trace_dump_stack(STACK_SKIP);
1174 stacktrace_count_trigger(struct event_trigger_data *data, void *rec,
1175 struct ring_buffer_event *event)
1180 if (data->count != -1)
1183 stacktrace_trigger(data, rec, event);
1187 stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1188 struct event_trigger_data *data)
1190 return event_trigger_print("stacktrace", m, (void *)data->count,
1194 static struct event_trigger_ops stacktrace_trigger_ops = {
1195 .func = stacktrace_trigger,
1196 .print = stacktrace_trigger_print,
1197 .init = event_trigger_init,
1198 .free = event_trigger_free,
1201 static struct event_trigger_ops stacktrace_count_trigger_ops = {
1202 .func = stacktrace_count_trigger,
1203 .print = stacktrace_trigger_print,
1204 .init = event_trigger_init,
1205 .free = event_trigger_free,
1208 static struct event_trigger_ops *
1209 stacktrace_get_trigger_ops(char *cmd, char *param)
1211 return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
1214 static struct event_command trigger_stacktrace_cmd = {
1215 .name = "stacktrace",
1216 .trigger_type = ETT_STACKTRACE,
1217 .flags = EVENT_CMD_FL_POST_TRIGGER,
1218 .func = event_trigger_callback,
1219 .reg = register_trigger,
1220 .unreg = unregister_trigger,
1221 .get_trigger_ops = stacktrace_get_trigger_ops,
1222 .set_filter = set_trigger_filter,
1225 static __init int register_trigger_stacktrace_cmd(void)
1229 ret = register_event_command(&trigger_stacktrace_cmd);
1235 static __init int register_trigger_stacktrace_cmd(void) { return 0; }
1236 #endif /* CONFIG_STACKTRACE */
1238 static __init void unregister_trigger_traceon_traceoff_cmds(void)
1240 unregister_event_command(&trigger_traceon_cmd);
1241 unregister_event_command(&trigger_traceoff_cmd);
1245 event_enable_trigger(struct event_trigger_data *data, void *rec,
1246 struct ring_buffer_event *event)
1248 struct enable_trigger_data *enable_data = data->private_data;
1250 if (enable_data->enable)
1251 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1253 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1257 event_enable_count_trigger(struct event_trigger_data *data, void *rec,
1258 struct ring_buffer_event *event)
1260 struct enable_trigger_data *enable_data = data->private_data;
1265 /* Skip if the event is in a state we want to switch to */
1266 if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
1269 if (data->count != -1)
1272 event_enable_trigger(data, rec, event);
1275 int event_enable_trigger_print(struct seq_file *m,
1276 struct event_trigger_ops *ops,
1277 struct event_trigger_data *data)
1279 struct enable_trigger_data *enable_data = data->private_data;
1281 seq_printf(m, "%s:%s:%s",
1283 (enable_data->enable ? ENABLE_HIST_STR : DISABLE_HIST_STR) :
1284 (enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR),
1285 enable_data->file->event_call->class->system,
1286 trace_event_name(enable_data->file->event_call));
1288 if (data->count == -1)
1289 seq_puts(m, ":unlimited");
1291 seq_printf(m, ":count=%ld", data->count);
1293 if (data->filter_str)
1294 seq_printf(m, " if %s\n", data->filter_str);
1301 void event_enable_trigger_free(struct event_trigger_ops *ops,
1302 struct event_trigger_data *data)
1304 struct enable_trigger_data *enable_data = data->private_data;
1306 if (WARN_ON_ONCE(data->ref <= 0))
1311 /* Remove the SOFT_MODE flag */
1312 trace_event_enable_disable(enable_data->file, 0, 1);
1313 module_put(enable_data->file->event_call->mod);
1314 trigger_data_free(data);
1319 static struct event_trigger_ops event_enable_trigger_ops = {
1320 .func = event_enable_trigger,
1321 .print = event_enable_trigger_print,
1322 .init = event_trigger_init,
1323 .free = event_enable_trigger_free,
1326 static struct event_trigger_ops event_enable_count_trigger_ops = {
1327 .func = event_enable_count_trigger,
1328 .print = event_enable_trigger_print,
1329 .init = event_trigger_init,
1330 .free = event_enable_trigger_free,
1333 static struct event_trigger_ops event_disable_trigger_ops = {
1334 .func = event_enable_trigger,
1335 .print = event_enable_trigger_print,
1336 .init = event_trigger_init,
1337 .free = event_enable_trigger_free,
1340 static struct event_trigger_ops event_disable_count_trigger_ops = {
1341 .func = event_enable_count_trigger,
1342 .print = event_enable_trigger_print,
1343 .init = event_trigger_init,
1344 .free = event_enable_trigger_free,
1347 int event_enable_trigger_func(struct event_command *cmd_ops,
1348 struct trace_event_file *file,
1349 char *glob, char *cmd, char *param)
1351 struct trace_event_file *event_enable_file;
1352 struct enable_trigger_data *enable_data;
1353 struct event_trigger_data *trigger_data;
1354 struct event_trigger_ops *trigger_ops;
1355 struct trace_array *tr = file->tr;
1367 /* separate the trigger from the filter (s:e:n [if filter]) */
1368 trigger = strsep(¶m, " \t");
1372 system = strsep(&trigger, ":");
1376 event = strsep(&trigger, ":");
1379 event_enable_file = find_event_file(tr, system, event);
1380 if (!event_enable_file)
1383 #ifdef CONFIG_HIST_TRIGGERS
1384 hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) ||
1385 (strcmp(cmd, DISABLE_HIST_STR) == 0));
1387 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1388 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1390 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1392 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
1395 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
1399 enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
1401 kfree(trigger_data);
1405 trigger_data->count = -1;
1406 trigger_data->ops = trigger_ops;
1407 trigger_data->cmd_ops = cmd_ops;
1408 INIT_LIST_HEAD(&trigger_data->list);
1409 RCU_INIT_POINTER(trigger_data->filter, NULL);
1411 enable_data->hist = hist;
1412 enable_data->enable = enable;
1413 enable_data->file = event_enable_file;
1414 trigger_data->private_data = enable_data;
1416 if (glob[0] == '!') {
1417 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
1418 kfree(trigger_data);
1424 /* Up the trigger_data count to make sure nothing frees it on failure */
1425 event_trigger_init(trigger_ops, trigger_data);
1428 number = strsep(&trigger, ":");
1431 if (!strlen(number))
1435 * We use the callback data field (which is a pointer)
1438 ret = kstrtoul(number, 0, &trigger_data->count);
1443 if (!param) /* if param is non-empty, it's supposed to be a filter */
1446 if (!cmd_ops->set_filter)
1449 ret = cmd_ops->set_filter(param, trigger_data, file);
1454 /* Don't let event modules unload while probe registered */
1455 ret = try_module_get(event_enable_file->event_call->mod);
1461 ret = trace_event_enable_disable(event_enable_file, 1, 1);
1464 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1466 * The above returns on success the # of functions enabled,
1467 * but if it didn't find any functions it returns zero.
1468 * Consider no functions a failure too.
1475 /* Just return zero, not the number of enabled functions */
1477 event_trigger_free(trigger_ops, trigger_data);
1482 trace_event_enable_disable(event_enable_file, 0, 1);
1484 module_put(event_enable_file->event_call->mod);
1486 if (cmd_ops->set_filter)
1487 cmd_ops->set_filter(NULL, trigger_data, NULL);
1488 event_trigger_free(trigger_ops, trigger_data);
1493 int event_enable_register_trigger(char *glob,
1494 struct event_trigger_ops *ops,
1495 struct event_trigger_data *data,
1496 struct trace_event_file *file)
1498 struct enable_trigger_data *enable_data = data->private_data;
1499 struct enable_trigger_data *test_enable_data;
1500 struct event_trigger_data *test;
1503 lockdep_assert_held(&event_mutex);
1505 list_for_each_entry(test, &file->triggers, list) {
1506 test_enable_data = test->private_data;
1507 if (test_enable_data &&
1508 (test->cmd_ops->trigger_type ==
1509 data->cmd_ops->trigger_type) &&
1510 (test_enable_data->file == enable_data->file)) {
1516 if (data->ops->init) {
1517 ret = data->ops->init(data->ops, data);
1522 list_add_rcu(&data->list, &file->triggers);
1525 update_cond_flag(file);
1526 if (trace_event_trigger_enable_disable(file, 1) < 0) {
1527 list_del_rcu(&data->list);
1528 update_cond_flag(file);
1535 void event_enable_unregister_trigger(char *glob,
1536 struct event_trigger_ops *ops,
1537 struct event_trigger_data *test,
1538 struct trace_event_file *file)
1540 struct enable_trigger_data *test_enable_data = test->private_data;
1541 struct enable_trigger_data *enable_data;
1542 struct event_trigger_data *data;
1543 bool unregistered = false;
1545 lockdep_assert_held(&event_mutex);
1547 list_for_each_entry(data, &file->triggers, list) {
1548 enable_data = data->private_data;
1550 (data->cmd_ops->trigger_type ==
1551 test->cmd_ops->trigger_type) &&
1552 (enable_data->file == test_enable_data->file)) {
1553 unregistered = true;
1554 list_del_rcu(&data->list);
1555 trace_event_trigger_enable_disable(file, 0);
1556 update_cond_flag(file);
1561 if (unregistered && data->ops->free)
1562 data->ops->free(data->ops, data);
1565 static struct event_trigger_ops *
1566 event_enable_get_trigger_ops(char *cmd, char *param)
1568 struct event_trigger_ops *ops;
1571 #ifdef CONFIG_HIST_TRIGGERS
1572 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1573 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1575 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1578 ops = param ? &event_enable_count_trigger_ops :
1579 &event_enable_trigger_ops;
1581 ops = param ? &event_disable_count_trigger_ops :
1582 &event_disable_trigger_ops;
1587 static struct event_command trigger_enable_cmd = {
1588 .name = ENABLE_EVENT_STR,
1589 .trigger_type = ETT_EVENT_ENABLE,
1590 .func = event_enable_trigger_func,
1591 .reg = event_enable_register_trigger,
1592 .unreg = event_enable_unregister_trigger,
1593 .get_trigger_ops = event_enable_get_trigger_ops,
1594 .set_filter = set_trigger_filter,
1597 static struct event_command trigger_disable_cmd = {
1598 .name = DISABLE_EVENT_STR,
1599 .trigger_type = ETT_EVENT_ENABLE,
1600 .func = event_enable_trigger_func,
1601 .reg = event_enable_register_trigger,
1602 .unreg = event_enable_unregister_trigger,
1603 .get_trigger_ops = event_enable_get_trigger_ops,
1604 .set_filter = set_trigger_filter,
1607 static __init void unregister_trigger_enable_disable_cmds(void)
1609 unregister_event_command(&trigger_enable_cmd);
1610 unregister_event_command(&trigger_disable_cmd);
1613 static __init int register_trigger_enable_disable_cmds(void)
1617 ret = register_event_command(&trigger_enable_cmd);
1618 if (WARN_ON(ret < 0))
1620 ret = register_event_command(&trigger_disable_cmd);
1621 if (WARN_ON(ret < 0))
1622 unregister_trigger_enable_disable_cmds();
1627 static __init int register_trigger_traceon_traceoff_cmds(void)
1631 ret = register_event_command(&trigger_traceon_cmd);
1632 if (WARN_ON(ret < 0))
1634 ret = register_event_command(&trigger_traceoff_cmd);
1635 if (WARN_ON(ret < 0))
1636 unregister_trigger_traceon_traceoff_cmds();
1641 __init int register_trigger_cmds(void)
1643 register_trigger_traceon_traceoff_cmds();
1644 register_trigger_snapshot_cmd();
1645 register_trigger_stacktrace_cmd();
1646 register_trigger_enable_disable_cmds();
1647 register_trigger_hist_enable_disable_cmds();
1648 register_trigger_hist_cmd();