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,
57 struct trace_buffer *buffer, void *rec,
58 struct ring_buffer_event *event)
60 struct event_trigger_data *data;
61 enum event_trigger_type tt = ETT_NONE;
62 struct event_filter *filter;
64 if (list_empty(&file->triggers))
67 list_for_each_entry_rcu(data, &file->triggers, list) {
71 data->ops->func(data, buffer, rec, event);
74 filter = rcu_dereference_sched(data->filter);
75 if (filter && !filter_match_preds(filter, rec))
77 if (event_command_post_trigger(data->cmd_ops)) {
78 tt |= data->cmd_ops->trigger_type;
81 data->ops->func(data, buffer, rec, event);
85 EXPORT_SYMBOL_GPL(event_triggers_call);
88 * event_triggers_post_call - Call 'post_triggers' for a trace event
89 * @file: The trace_event_file associated with the event
90 * @tt: enum event_trigger_type containing a set bit for each trigger to invoke
92 * For each trigger associated with an event, invoke the trigger
93 * function registered with the associated trigger command, if the
94 * corresponding bit is set in the tt enum passed into this function.
95 * See @event_triggers_call for details on how those bits are set.
97 * Called from tracepoint handlers (with rcu_read_lock_sched() held).
100 event_triggers_post_call(struct trace_event_file *file,
101 enum event_trigger_type tt)
103 struct event_trigger_data *data;
105 list_for_each_entry_rcu(data, &file->triggers, list) {
108 if (data->cmd_ops->trigger_type & tt)
109 data->ops->func(data, NULL, NULL, NULL);
112 EXPORT_SYMBOL_GPL(event_triggers_post_call);
114 #define SHOW_AVAILABLE_TRIGGERS (void *)(1UL)
116 static void *trigger_next(struct seq_file *m, void *t, loff_t *pos)
118 struct trace_event_file *event_file = event_file_data(m->private);
120 if (t == SHOW_AVAILABLE_TRIGGERS) {
124 return seq_list_next(t, &event_file->triggers, pos);
127 static void *trigger_start(struct seq_file *m, loff_t *pos)
129 struct trace_event_file *event_file;
131 /* ->stop() is called even if ->start() fails */
132 mutex_lock(&event_mutex);
133 event_file = event_file_data(m->private);
134 if (unlikely(!event_file))
135 return ERR_PTR(-ENODEV);
137 if (list_empty(&event_file->triggers))
138 return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL;
140 return seq_list_start(&event_file->triggers, *pos);
143 static void trigger_stop(struct seq_file *m, void *t)
145 mutex_unlock(&event_mutex);
148 static int trigger_show(struct seq_file *m, void *v)
150 struct event_trigger_data *data;
151 struct event_command *p;
153 if (v == SHOW_AVAILABLE_TRIGGERS) {
154 seq_puts(m, "# Available triggers:\n");
156 mutex_lock(&trigger_cmd_mutex);
157 list_for_each_entry_reverse(p, &trigger_commands, list)
158 seq_printf(m, " %s", p->name);
160 mutex_unlock(&trigger_cmd_mutex);
164 data = list_entry(v, struct event_trigger_data, list);
165 data->ops->print(m, data->ops, data);
170 static const struct seq_operations event_triggers_seq_ops = {
171 .start = trigger_start,
172 .next = trigger_next,
173 .stop = trigger_stop,
174 .show = trigger_show,
177 static int event_trigger_regex_open(struct inode *inode, struct file *file)
181 ret = security_locked_down(LOCKDOWN_TRACEFS);
185 mutex_lock(&event_mutex);
187 if (unlikely(!event_file_data(file))) {
188 mutex_unlock(&event_mutex);
192 if ((file->f_mode & FMODE_WRITE) &&
193 (file->f_flags & O_TRUNC)) {
194 struct trace_event_file *event_file;
195 struct event_command *p;
197 event_file = event_file_data(file);
199 list_for_each_entry(p, &trigger_commands, list) {
201 p->unreg_all(event_file);
205 if (file->f_mode & FMODE_READ) {
206 ret = seq_open(file, &event_triggers_seq_ops);
208 struct seq_file *m = file->private_data;
213 mutex_unlock(&event_mutex);
218 int trigger_process_regex(struct trace_event_file *file, char *buff)
220 char *command, *next;
221 struct event_command *p;
224 next = buff = skip_spaces(buff);
225 command = strsep(&next, ": \t");
227 next = skip_spaces(next);
231 command = (command[0] != '!') ? command : command + 1;
233 mutex_lock(&trigger_cmd_mutex);
234 list_for_each_entry(p, &trigger_commands, list) {
235 if (strcmp(p->name, command) == 0) {
236 ret = p->func(p, file, buff, command, next);
241 mutex_unlock(&trigger_cmd_mutex);
246 static ssize_t event_trigger_regex_write(struct file *file,
247 const char __user *ubuf,
248 size_t cnt, loff_t *ppos)
250 struct trace_event_file *event_file;
257 if (cnt >= PAGE_SIZE)
260 buf = memdup_user_nul(ubuf, cnt);
266 mutex_lock(&event_mutex);
267 event_file = event_file_data(file);
268 if (unlikely(!event_file)) {
269 mutex_unlock(&event_mutex);
273 ret = trigger_process_regex(event_file, buf);
274 mutex_unlock(&event_mutex);
286 static int event_trigger_regex_release(struct inode *inode, struct file *file)
288 mutex_lock(&event_mutex);
290 if (file->f_mode & FMODE_READ)
291 seq_release(inode, file);
293 mutex_unlock(&event_mutex);
299 event_trigger_write(struct file *filp, const char __user *ubuf,
300 size_t cnt, loff_t *ppos)
302 return event_trigger_regex_write(filp, ubuf, cnt, ppos);
306 event_trigger_open(struct inode *inode, struct file *filp)
308 /* Checks for tracefs lockdown */
309 return event_trigger_regex_open(inode, filp);
313 event_trigger_release(struct inode *inode, struct file *file)
315 return event_trigger_regex_release(inode, file);
318 const struct file_operations event_trigger_fops = {
319 .open = event_trigger_open,
321 .write = event_trigger_write,
322 .llseek = tracing_lseek,
323 .release = event_trigger_release,
327 * Currently we only register event commands from __init, so mark this
330 __init int register_event_command(struct event_command *cmd)
332 struct event_command *p;
335 mutex_lock(&trigger_cmd_mutex);
336 list_for_each_entry(p, &trigger_commands, list) {
337 if (strcmp(cmd->name, p->name) == 0) {
342 list_add(&cmd->list, &trigger_commands);
344 mutex_unlock(&trigger_cmd_mutex);
350 * Currently we only unregister event commands from __init, so mark
353 __init int unregister_event_command(struct event_command *cmd)
355 struct event_command *p, *n;
358 mutex_lock(&trigger_cmd_mutex);
359 list_for_each_entry_safe(p, n, &trigger_commands, list) {
360 if (strcmp(cmd->name, p->name) == 0) {
362 list_del_init(&p->list);
367 mutex_unlock(&trigger_cmd_mutex);
373 * event_trigger_print - Generic event_trigger_ops @print implementation
374 * @name: The name of the event trigger
375 * @m: The seq_file being printed to
376 * @data: Trigger-specific data
377 * @filter_str: filter_str to print, if present
379 * Common implementation for event triggers to print themselves.
381 * Usually wrapped by a function that simply sets the @name of the
382 * trigger command and then invokes this.
384 * Return: 0 on success, errno otherwise
387 event_trigger_print(const char *name, struct seq_file *m,
388 void *data, char *filter_str)
390 long count = (long)data;
395 seq_puts(m, ":unlimited");
397 seq_printf(m, ":count=%ld", count);
400 seq_printf(m, " if %s\n", filter_str);
408 * event_trigger_init - Generic event_trigger_ops @init implementation
409 * @ops: The trigger ops associated with the trigger
410 * @data: Trigger-specific data
412 * Common implementation of event trigger initialization.
414 * Usually used directly as the @init method in event trigger
417 * Return: 0 on success, errno otherwise
419 int event_trigger_init(struct event_trigger_ops *ops,
420 struct event_trigger_data *data)
427 * event_trigger_free - Generic event_trigger_ops @free implementation
428 * @ops: The trigger ops associated with the trigger
429 * @data: Trigger-specific data
431 * Common implementation of event trigger de-initialization.
433 * Usually used directly as the @free method in event trigger
437 event_trigger_free(struct event_trigger_ops *ops,
438 struct event_trigger_data *data)
440 if (WARN_ON_ONCE(data->ref <= 0))
445 trigger_data_free(data);
448 int trace_event_trigger_enable_disable(struct trace_event_file *file,
453 if (trigger_enable) {
454 if (atomic_inc_return(&file->tm_ref) > 1)
456 set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
457 ret = trace_event_enable_disable(file, 1, 1);
459 if (atomic_dec_return(&file->tm_ref) > 0)
461 clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
462 ret = trace_event_enable_disable(file, 0, 1);
469 * clear_event_triggers - Clear all triggers associated with a trace array
470 * @tr: The trace array to clear
472 * For each trigger, the triggering event has its tm_ref decremented
473 * via trace_event_trigger_enable_disable(), and any associated event
474 * (in the case of enable/disable_event triggers) will have its sm_ref
475 * decremented via free()->trace_event_enable_disable(). That
476 * combination effectively reverses the soft-mode/trigger state added
477 * by trigger registration.
479 * Must be called with event_mutex held.
482 clear_event_triggers(struct trace_array *tr)
484 struct trace_event_file *file;
486 list_for_each_entry(file, &tr->events, list) {
487 struct event_trigger_data *data, *n;
488 list_for_each_entry_safe(data, n, &file->triggers, list) {
489 trace_event_trigger_enable_disable(file, 0);
490 list_del_rcu(&data->list);
492 data->ops->free(data->ops, data);
498 * update_cond_flag - Set or reset the TRIGGER_COND bit
499 * @file: The trace_event_file associated with the event
501 * If an event has triggers and any of those triggers has a filter or
502 * a post_trigger, trigger invocation needs to be deferred until after
503 * the current event has logged its data, and the event should have
504 * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be
507 void update_cond_flag(struct trace_event_file *file)
509 struct event_trigger_data *data;
510 bool set_cond = false;
512 lockdep_assert_held(&event_mutex);
514 list_for_each_entry(data, &file->triggers, list) {
515 if (data->filter || event_command_post_trigger(data->cmd_ops) ||
516 event_command_needs_rec(data->cmd_ops)) {
523 set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
525 clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
529 * register_trigger - Generic event_command @reg implementation
530 * @glob: The raw string used to register the trigger
531 * @ops: The trigger ops associated with the trigger
532 * @data: Trigger-specific data to associate with the trigger
533 * @file: The trace_event_file associated with the event
535 * Common implementation for event trigger registration.
537 * Usually used directly as the @reg method in event command
540 * Return: 0 on success, errno otherwise
542 static int register_trigger(char *glob, struct event_trigger_ops *ops,
543 struct event_trigger_data *data,
544 struct trace_event_file *file)
546 struct event_trigger_data *test;
549 lockdep_assert_held(&event_mutex);
551 list_for_each_entry(test, &file->triggers, list) {
552 if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) {
558 if (data->ops->init) {
559 ret = data->ops->init(data->ops, data);
564 list_add_rcu(&data->list, &file->triggers);
567 update_cond_flag(file);
568 if (trace_event_trigger_enable_disable(file, 1) < 0) {
569 list_del_rcu(&data->list);
570 update_cond_flag(file);
578 * unregister_trigger - Generic event_command @unreg implementation
579 * @glob: The raw string used to register the trigger
580 * @ops: The trigger ops associated with the trigger
581 * @test: Trigger-specific data used to find the trigger to remove
582 * @file: The trace_event_file associated with the event
584 * Common implementation for event trigger unregistration.
586 * Usually used directly as the @unreg method in event command
589 static void unregister_trigger(char *glob, struct event_trigger_ops *ops,
590 struct event_trigger_data *test,
591 struct trace_event_file *file)
593 struct event_trigger_data *data;
594 bool unregistered = false;
596 lockdep_assert_held(&event_mutex);
598 list_for_each_entry(data, &file->triggers, list) {
599 if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
601 list_del_rcu(&data->list);
602 trace_event_trigger_enable_disable(file, 0);
603 update_cond_flag(file);
608 if (unregistered && data->ops->free)
609 data->ops->free(data->ops, data);
613 * event_trigger_callback - Generic event_command @func implementation
614 * @cmd_ops: The command ops, used for trigger registration
615 * @file: The trace_event_file associated with the event
616 * @glob: The raw string used to register the trigger
617 * @cmd: The cmd portion of the string used to register the trigger
618 * @param: The params portion of the string used to register the trigger
620 * Common implementation for event command parsing and trigger
623 * Usually used directly as the @func method in event command
626 * Return: 0 on success, errno otherwise
629 event_trigger_callback(struct event_command *cmd_ops,
630 struct trace_event_file *file,
631 char *glob, char *cmd, char *param)
633 struct event_trigger_data *trigger_data;
634 struct event_trigger_ops *trigger_ops;
635 char *trigger = NULL;
639 /* separate the trigger from the filter (t:n [if filter]) */
640 if (param && isdigit(param[0])) {
641 trigger = strsep(¶m, " \t");
643 param = skip_spaces(param);
649 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
652 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
656 trigger_data->count = -1;
657 trigger_data->ops = trigger_ops;
658 trigger_data->cmd_ops = cmd_ops;
659 trigger_data->private_data = file;
660 INIT_LIST_HEAD(&trigger_data->list);
661 INIT_LIST_HEAD(&trigger_data->named_list);
663 if (glob[0] == '!') {
664 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
671 number = strsep(&trigger, ":");
678 * We use the callback data field (which is a pointer)
681 ret = kstrtoul(number, 0, &trigger_data->count);
686 if (!param) /* if param is non-empty, it's supposed to be a filter */
689 if (!cmd_ops->set_filter)
692 ret = cmd_ops->set_filter(param, trigger_data, file);
697 /* Up the trigger_data count to make sure reg doesn't free it on failure */
698 event_trigger_init(trigger_ops, trigger_data);
699 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
701 * The above returns on success the # of functions enabled,
702 * but if it didn't find any functions it returns zero.
703 * Consider no functions a failure too.
706 cmd_ops->unreg(glob, trigger_ops, trigger_data, file);
711 /* Down the counter of trigger_data or free it if not used anymore */
712 event_trigger_free(trigger_ops, trigger_data);
717 if (cmd_ops->set_filter)
718 cmd_ops->set_filter(NULL, trigger_data, NULL);
724 * set_trigger_filter - Generic event_command @set_filter implementation
725 * @filter_str: The filter string for the trigger, NULL to remove filter
726 * @trigger_data: Trigger-specific data
727 * @file: The trace_event_file associated with the event
729 * Common implementation for event command filter parsing and filter
732 * Usually used directly as the @set_filter method in event command
735 * Also used to remove a filter (if filter_str = NULL).
737 * Return: 0 on success, errno otherwise
739 int set_trigger_filter(char *filter_str,
740 struct event_trigger_data *trigger_data,
741 struct trace_event_file *file)
743 struct event_trigger_data *data = trigger_data;
744 struct event_filter *filter = NULL, *tmp;
748 if (!filter_str) /* clear the current filter */
751 s = strsep(&filter_str, " \t");
753 if (!strlen(s) || strcmp(s, "if") != 0)
759 /* The filter is for the 'trigger' event, not the triggered event */
760 ret = create_event_filter(file->tr, file->event_call,
761 filter_str, false, &filter);
763 * If create_event_filter() fails, filter still needs to be freed.
764 * Which the calling code will do with data->filter.
767 tmp = rcu_access_pointer(data->filter);
769 rcu_assign_pointer(data->filter, filter);
772 /* Make sure the call is done with the filter */
773 tracepoint_synchronize_unregister();
774 free_event_filter(tmp);
777 kfree(data->filter_str);
778 data->filter_str = NULL;
781 data->filter_str = kstrdup(filter_str, GFP_KERNEL);
782 if (!data->filter_str) {
783 free_event_filter(rcu_access_pointer(data->filter));
792 static LIST_HEAD(named_triggers);
795 * find_named_trigger - Find the common named trigger associated with @name
796 * @name: The name of the set of named triggers to find the common data for
798 * Named triggers are sets of triggers that share a common set of
799 * trigger data. The first named trigger registered with a given name
800 * owns the common trigger data that the others subsequently
801 * registered with the same name will reference. This function
802 * returns the common trigger data associated with that first
803 * registered instance.
805 * Return: the common trigger data for the given named trigger on
806 * success, NULL otherwise.
808 struct event_trigger_data *find_named_trigger(const char *name)
810 struct event_trigger_data *data;
815 list_for_each_entry(data, &named_triggers, named_list) {
816 if (data->named_data)
818 if (strcmp(data->name, name) == 0)
826 * is_named_trigger - determine if a given trigger is a named trigger
827 * @test: The trigger data to test
829 * Return: true if 'test' is a named trigger, false otherwise.
831 bool is_named_trigger(struct event_trigger_data *test)
833 struct event_trigger_data *data;
835 list_for_each_entry(data, &named_triggers, named_list) {
844 * save_named_trigger - save the trigger in the named trigger list
845 * @name: The name of the named trigger set
846 * @data: The trigger data to save
848 * Return: 0 if successful, negative error otherwise.
850 int save_named_trigger(const char *name, struct event_trigger_data *data)
852 data->name = kstrdup(name, GFP_KERNEL);
856 list_add(&data->named_list, &named_triggers);
862 * del_named_trigger - delete a trigger from the named trigger list
863 * @data: The trigger data to delete
865 void del_named_trigger(struct event_trigger_data *data)
870 list_del(&data->named_list);
873 static void __pause_named_trigger(struct event_trigger_data *data, bool pause)
875 struct event_trigger_data *test;
877 list_for_each_entry(test, &named_triggers, named_list) {
878 if (strcmp(test->name, data->name) == 0) {
880 test->paused_tmp = test->paused;
883 test->paused = test->paused_tmp;
890 * pause_named_trigger - Pause all named triggers with the same name
891 * @data: The trigger data of a named trigger to pause
893 * Pauses a named trigger along with all other triggers having the
894 * same name. Because named triggers share a common set of data,
895 * pausing only one is meaningless, so pausing one named trigger needs
896 * to pause all triggers with the same name.
898 void pause_named_trigger(struct event_trigger_data *data)
900 __pause_named_trigger(data, true);
904 * unpause_named_trigger - Un-pause all named triggers with the same name
905 * @data: The trigger data of a named trigger to unpause
907 * Un-pauses a named trigger along with all other triggers having the
908 * same name. Because named triggers share a common set of data,
909 * unpausing only one is meaningless, so unpausing one named trigger
910 * needs to unpause all triggers with the same name.
912 void unpause_named_trigger(struct event_trigger_data *data)
914 __pause_named_trigger(data, false);
918 * set_named_trigger_data - Associate common named trigger data
919 * @data: The trigger data to associate
920 * @named_data: The common named trigger to be associated
922 * Named triggers are sets of triggers that share a common set of
923 * trigger data. The first named trigger registered with a given name
924 * owns the common trigger data that the others subsequently
925 * registered with the same name will reference. This function
926 * associates the common trigger data from the first trigger with the
929 void set_named_trigger_data(struct event_trigger_data *data,
930 struct event_trigger_data *named_data)
932 data->named_data = named_data;
935 struct event_trigger_data *
936 get_named_trigger_data(struct event_trigger_data *data)
938 return data->named_data;
942 traceon_trigger(struct event_trigger_data *data,
943 struct trace_buffer *buffer, void *rec,
944 struct ring_buffer_event *event)
953 traceon_count_trigger(struct event_trigger_data *data,
954 struct trace_buffer *buffer, void *rec,
955 struct ring_buffer_event *event)
963 if (data->count != -1)
970 traceoff_trigger(struct event_trigger_data *data,
971 struct trace_buffer *buffer, void *rec,
972 struct ring_buffer_event *event)
974 if (!tracing_is_on())
981 traceoff_count_trigger(struct event_trigger_data *data,
982 struct trace_buffer *buffer, void *rec,
983 struct ring_buffer_event *event)
985 if (!tracing_is_on())
991 if (data->count != -1)
998 traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
999 struct event_trigger_data *data)
1001 return event_trigger_print("traceon", m, (void *)data->count,
1006 traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1007 struct event_trigger_data *data)
1009 return event_trigger_print("traceoff", m, (void *)data->count,
1013 static struct event_trigger_ops traceon_trigger_ops = {
1014 .func = traceon_trigger,
1015 .print = traceon_trigger_print,
1016 .init = event_trigger_init,
1017 .free = event_trigger_free,
1020 static struct event_trigger_ops traceon_count_trigger_ops = {
1021 .func = traceon_count_trigger,
1022 .print = traceon_trigger_print,
1023 .init = event_trigger_init,
1024 .free = event_trigger_free,
1027 static struct event_trigger_ops traceoff_trigger_ops = {
1028 .func = traceoff_trigger,
1029 .print = traceoff_trigger_print,
1030 .init = event_trigger_init,
1031 .free = event_trigger_free,
1034 static struct event_trigger_ops traceoff_count_trigger_ops = {
1035 .func = traceoff_count_trigger,
1036 .print = traceoff_trigger_print,
1037 .init = event_trigger_init,
1038 .free = event_trigger_free,
1041 static struct event_trigger_ops *
1042 onoff_get_trigger_ops(char *cmd, char *param)
1044 struct event_trigger_ops *ops;
1046 /* we register both traceon and traceoff to this callback */
1047 if (strcmp(cmd, "traceon") == 0)
1048 ops = param ? &traceon_count_trigger_ops :
1049 &traceon_trigger_ops;
1051 ops = param ? &traceoff_count_trigger_ops :
1052 &traceoff_trigger_ops;
1057 static struct event_command trigger_traceon_cmd = {
1059 .trigger_type = ETT_TRACE_ONOFF,
1060 .func = event_trigger_callback,
1061 .reg = register_trigger,
1062 .unreg = unregister_trigger,
1063 .get_trigger_ops = onoff_get_trigger_ops,
1064 .set_filter = set_trigger_filter,
1067 static struct event_command trigger_traceoff_cmd = {
1069 .trigger_type = ETT_TRACE_ONOFF,
1070 .flags = EVENT_CMD_FL_POST_TRIGGER,
1071 .func = event_trigger_callback,
1072 .reg = register_trigger,
1073 .unreg = unregister_trigger,
1074 .get_trigger_ops = onoff_get_trigger_ops,
1075 .set_filter = set_trigger_filter,
1078 #ifdef CONFIG_TRACER_SNAPSHOT
1080 snapshot_trigger(struct event_trigger_data *data,
1081 struct trace_buffer *buffer, void *rec,
1082 struct ring_buffer_event *event)
1084 struct trace_event_file *file = data->private_data;
1087 tracing_snapshot_instance(file->tr);
1093 snapshot_count_trigger(struct event_trigger_data *data,
1094 struct trace_buffer *buffer, void *rec,
1095 struct ring_buffer_event *event)
1100 if (data->count != -1)
1103 snapshot_trigger(data, buffer, rec, event);
1107 register_snapshot_trigger(char *glob, struct event_trigger_ops *ops,
1108 struct event_trigger_data *data,
1109 struct trace_event_file *file)
1111 if (tracing_alloc_snapshot_instance(file->tr) != 0)
1114 return register_trigger(glob, ops, data, file);
1118 snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1119 struct event_trigger_data *data)
1121 return event_trigger_print("snapshot", m, (void *)data->count,
1125 static struct event_trigger_ops snapshot_trigger_ops = {
1126 .func = snapshot_trigger,
1127 .print = snapshot_trigger_print,
1128 .init = event_trigger_init,
1129 .free = event_trigger_free,
1132 static struct event_trigger_ops snapshot_count_trigger_ops = {
1133 .func = snapshot_count_trigger,
1134 .print = snapshot_trigger_print,
1135 .init = event_trigger_init,
1136 .free = event_trigger_free,
1139 static struct event_trigger_ops *
1140 snapshot_get_trigger_ops(char *cmd, char *param)
1142 return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
1145 static struct event_command trigger_snapshot_cmd = {
1147 .trigger_type = ETT_SNAPSHOT,
1148 .func = event_trigger_callback,
1149 .reg = register_snapshot_trigger,
1150 .unreg = unregister_trigger,
1151 .get_trigger_ops = snapshot_get_trigger_ops,
1152 .set_filter = set_trigger_filter,
1155 static __init int register_trigger_snapshot_cmd(void)
1159 ret = register_event_command(&trigger_snapshot_cmd);
1165 static __init int register_trigger_snapshot_cmd(void) { return 0; }
1166 #endif /* CONFIG_TRACER_SNAPSHOT */
1168 #ifdef CONFIG_STACKTRACE
1169 #ifdef CONFIG_UNWINDER_ORC
1171 * event_triggers_post_call()
1172 * trace_event_raw_event_xxx()
1174 # define STACK_SKIP 2
1178 * stacktrace_trigger()
1179 * event_triggers_post_call()
1180 * trace_event_buffer_commit()
1181 * trace_event_raw_event_xxx()
1183 #define STACK_SKIP 4
1187 stacktrace_trigger(struct event_trigger_data *data,
1188 struct trace_buffer *buffer, void *rec,
1189 struct ring_buffer_event *event)
1191 trace_dump_stack(STACK_SKIP);
1195 stacktrace_count_trigger(struct event_trigger_data *data,
1196 struct trace_buffer *buffer, void *rec,
1197 struct ring_buffer_event *event)
1202 if (data->count != -1)
1205 stacktrace_trigger(data, buffer, rec, event);
1209 stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1210 struct event_trigger_data *data)
1212 return event_trigger_print("stacktrace", m, (void *)data->count,
1216 static struct event_trigger_ops stacktrace_trigger_ops = {
1217 .func = stacktrace_trigger,
1218 .print = stacktrace_trigger_print,
1219 .init = event_trigger_init,
1220 .free = event_trigger_free,
1223 static struct event_trigger_ops stacktrace_count_trigger_ops = {
1224 .func = stacktrace_count_trigger,
1225 .print = stacktrace_trigger_print,
1226 .init = event_trigger_init,
1227 .free = event_trigger_free,
1230 static struct event_trigger_ops *
1231 stacktrace_get_trigger_ops(char *cmd, char *param)
1233 return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
1236 static struct event_command trigger_stacktrace_cmd = {
1237 .name = "stacktrace",
1238 .trigger_type = ETT_STACKTRACE,
1239 .flags = EVENT_CMD_FL_POST_TRIGGER,
1240 .func = event_trigger_callback,
1241 .reg = register_trigger,
1242 .unreg = unregister_trigger,
1243 .get_trigger_ops = stacktrace_get_trigger_ops,
1244 .set_filter = set_trigger_filter,
1247 static __init int register_trigger_stacktrace_cmd(void)
1251 ret = register_event_command(&trigger_stacktrace_cmd);
1257 static __init int register_trigger_stacktrace_cmd(void) { return 0; }
1258 #endif /* CONFIG_STACKTRACE */
1260 static __init void unregister_trigger_traceon_traceoff_cmds(void)
1262 unregister_event_command(&trigger_traceon_cmd);
1263 unregister_event_command(&trigger_traceoff_cmd);
1267 event_enable_trigger(struct event_trigger_data *data,
1268 struct trace_buffer *buffer, void *rec,
1269 struct ring_buffer_event *event)
1271 struct enable_trigger_data *enable_data = data->private_data;
1273 if (enable_data->enable)
1274 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1276 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1280 event_enable_count_trigger(struct event_trigger_data *data,
1281 struct trace_buffer *buffer, void *rec,
1282 struct ring_buffer_event *event)
1284 struct enable_trigger_data *enable_data = data->private_data;
1289 /* Skip if the event is in a state we want to switch to */
1290 if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
1293 if (data->count != -1)
1296 event_enable_trigger(data, buffer, rec, event);
1299 int event_enable_trigger_print(struct seq_file *m,
1300 struct event_trigger_ops *ops,
1301 struct event_trigger_data *data)
1303 struct enable_trigger_data *enable_data = data->private_data;
1305 seq_printf(m, "%s:%s:%s",
1307 (enable_data->enable ? ENABLE_HIST_STR : DISABLE_HIST_STR) :
1308 (enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR),
1309 enable_data->file->event_call->class->system,
1310 trace_event_name(enable_data->file->event_call));
1312 if (data->count == -1)
1313 seq_puts(m, ":unlimited");
1315 seq_printf(m, ":count=%ld", data->count);
1317 if (data->filter_str)
1318 seq_printf(m, " if %s\n", data->filter_str);
1325 void event_enable_trigger_free(struct event_trigger_ops *ops,
1326 struct event_trigger_data *data)
1328 struct enable_trigger_data *enable_data = data->private_data;
1330 if (WARN_ON_ONCE(data->ref <= 0))
1335 /* Remove the SOFT_MODE flag */
1336 trace_event_enable_disable(enable_data->file, 0, 1);
1337 module_put(enable_data->file->event_call->mod);
1338 trigger_data_free(data);
1343 static struct event_trigger_ops event_enable_trigger_ops = {
1344 .func = event_enable_trigger,
1345 .print = event_enable_trigger_print,
1346 .init = event_trigger_init,
1347 .free = event_enable_trigger_free,
1350 static struct event_trigger_ops event_enable_count_trigger_ops = {
1351 .func = event_enable_count_trigger,
1352 .print = event_enable_trigger_print,
1353 .init = event_trigger_init,
1354 .free = event_enable_trigger_free,
1357 static struct event_trigger_ops event_disable_trigger_ops = {
1358 .func = event_enable_trigger,
1359 .print = event_enable_trigger_print,
1360 .init = event_trigger_init,
1361 .free = event_enable_trigger_free,
1364 static struct event_trigger_ops event_disable_count_trigger_ops = {
1365 .func = event_enable_count_trigger,
1366 .print = event_enable_trigger_print,
1367 .init = event_trigger_init,
1368 .free = event_enable_trigger_free,
1371 int event_enable_trigger_func(struct event_command *cmd_ops,
1372 struct trace_event_file *file,
1373 char *glob, char *cmd, char *param)
1375 struct trace_event_file *event_enable_file;
1376 struct enable_trigger_data *enable_data;
1377 struct event_trigger_data *trigger_data;
1378 struct event_trigger_ops *trigger_ops;
1379 struct trace_array *tr = file->tr;
1391 /* separate the trigger from the filter (s:e:n [if filter]) */
1392 trigger = strsep(¶m, " \t");
1396 param = skip_spaces(param);
1401 system = strsep(&trigger, ":");
1405 event = strsep(&trigger, ":");
1408 event_enable_file = find_event_file(tr, system, event);
1409 if (!event_enable_file)
1412 #ifdef CONFIG_HIST_TRIGGERS
1413 hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) ||
1414 (strcmp(cmd, DISABLE_HIST_STR) == 0));
1416 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1417 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1419 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1421 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
1424 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
1428 enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
1430 kfree(trigger_data);
1434 trigger_data->count = -1;
1435 trigger_data->ops = trigger_ops;
1436 trigger_data->cmd_ops = cmd_ops;
1437 INIT_LIST_HEAD(&trigger_data->list);
1438 RCU_INIT_POINTER(trigger_data->filter, NULL);
1440 enable_data->hist = hist;
1441 enable_data->enable = enable;
1442 enable_data->file = event_enable_file;
1443 trigger_data->private_data = enable_data;
1445 if (glob[0] == '!') {
1446 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
1447 kfree(trigger_data);
1453 /* Up the trigger_data count to make sure nothing frees it on failure */
1454 event_trigger_init(trigger_ops, trigger_data);
1457 number = strsep(&trigger, ":");
1460 if (!strlen(number))
1464 * We use the callback data field (which is a pointer)
1467 ret = kstrtoul(number, 0, &trigger_data->count);
1472 if (!param) /* if param is non-empty, it's supposed to be a filter */
1475 if (!cmd_ops->set_filter)
1478 ret = cmd_ops->set_filter(param, trigger_data, file);
1483 /* Don't let event modules unload while probe registered */
1484 ret = try_module_get(event_enable_file->event_call->mod);
1490 ret = trace_event_enable_disable(event_enable_file, 1, 1);
1493 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1495 * The above returns on success the # of functions enabled,
1496 * but if it didn't find any functions it returns zero.
1497 * Consider no functions a failure too.
1504 /* Just return zero, not the number of enabled functions */
1506 event_trigger_free(trigger_ops, trigger_data);
1511 trace_event_enable_disable(event_enable_file, 0, 1);
1513 module_put(event_enable_file->event_call->mod);
1515 if (cmd_ops->set_filter)
1516 cmd_ops->set_filter(NULL, trigger_data, NULL);
1517 event_trigger_free(trigger_ops, trigger_data);
1522 int event_enable_register_trigger(char *glob,
1523 struct event_trigger_ops *ops,
1524 struct event_trigger_data *data,
1525 struct trace_event_file *file)
1527 struct enable_trigger_data *enable_data = data->private_data;
1528 struct enable_trigger_data *test_enable_data;
1529 struct event_trigger_data *test;
1532 lockdep_assert_held(&event_mutex);
1534 list_for_each_entry(test, &file->triggers, list) {
1535 test_enable_data = test->private_data;
1536 if (test_enable_data &&
1537 (test->cmd_ops->trigger_type ==
1538 data->cmd_ops->trigger_type) &&
1539 (test_enable_data->file == enable_data->file)) {
1545 if (data->ops->init) {
1546 ret = data->ops->init(data->ops, data);
1551 list_add_rcu(&data->list, &file->triggers);
1554 update_cond_flag(file);
1555 if (trace_event_trigger_enable_disable(file, 1) < 0) {
1556 list_del_rcu(&data->list);
1557 update_cond_flag(file);
1564 void event_enable_unregister_trigger(char *glob,
1565 struct event_trigger_ops *ops,
1566 struct event_trigger_data *test,
1567 struct trace_event_file *file)
1569 struct enable_trigger_data *test_enable_data = test->private_data;
1570 struct enable_trigger_data *enable_data;
1571 struct event_trigger_data *data;
1572 bool unregistered = false;
1574 lockdep_assert_held(&event_mutex);
1576 list_for_each_entry(data, &file->triggers, list) {
1577 enable_data = data->private_data;
1579 (data->cmd_ops->trigger_type ==
1580 test->cmd_ops->trigger_type) &&
1581 (enable_data->file == test_enable_data->file)) {
1582 unregistered = true;
1583 list_del_rcu(&data->list);
1584 trace_event_trigger_enable_disable(file, 0);
1585 update_cond_flag(file);
1590 if (unregistered && data->ops->free)
1591 data->ops->free(data->ops, data);
1594 static struct event_trigger_ops *
1595 event_enable_get_trigger_ops(char *cmd, char *param)
1597 struct event_trigger_ops *ops;
1600 #ifdef CONFIG_HIST_TRIGGERS
1601 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1602 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1604 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1607 ops = param ? &event_enable_count_trigger_ops :
1608 &event_enable_trigger_ops;
1610 ops = param ? &event_disable_count_trigger_ops :
1611 &event_disable_trigger_ops;
1616 static struct event_command trigger_enable_cmd = {
1617 .name = ENABLE_EVENT_STR,
1618 .trigger_type = ETT_EVENT_ENABLE,
1619 .func = event_enable_trigger_func,
1620 .reg = event_enable_register_trigger,
1621 .unreg = event_enable_unregister_trigger,
1622 .get_trigger_ops = event_enable_get_trigger_ops,
1623 .set_filter = set_trigger_filter,
1626 static struct event_command trigger_disable_cmd = {
1627 .name = DISABLE_EVENT_STR,
1628 .trigger_type = ETT_EVENT_ENABLE,
1629 .func = event_enable_trigger_func,
1630 .reg = event_enable_register_trigger,
1631 .unreg = event_enable_unregister_trigger,
1632 .get_trigger_ops = event_enable_get_trigger_ops,
1633 .set_filter = set_trigger_filter,
1636 static __init void unregister_trigger_enable_disable_cmds(void)
1638 unregister_event_command(&trigger_enable_cmd);
1639 unregister_event_command(&trigger_disable_cmd);
1642 static __init int register_trigger_enable_disable_cmds(void)
1646 ret = register_event_command(&trigger_enable_cmd);
1647 if (WARN_ON(ret < 0))
1649 ret = register_event_command(&trigger_disable_cmd);
1650 if (WARN_ON(ret < 0))
1651 unregister_trigger_enable_disable_cmds();
1656 static __init int register_trigger_traceon_traceoff_cmds(void)
1660 ret = register_event_command(&trigger_traceon_cmd);
1661 if (WARN_ON(ret < 0))
1663 ret = register_event_command(&trigger_traceoff_cmd);
1664 if (WARN_ON(ret < 0))
1665 unregister_trigger_traceon_traceoff_cmds();
1670 __init int register_trigger_cmds(void)
1672 register_trigger_traceon_traceoff_cmds();
1673 register_trigger_snapshot_cmd();
1674 register_trigger_stacktrace_cmd();
1675 register_trigger_enable_disable_cmds();
1676 register_trigger_hist_enable_disable_cmds();
1677 register_trigger_hist_cmd();