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;
220 struct event_command *p;
223 next = buff = skip_spaces(buff);
224 command = strsep(&next, ": \t");
226 next = skip_spaces(next);
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);
240 mutex_unlock(&trigger_cmd_mutex);
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;
256 if (cnt >= PAGE_SIZE)
259 buf = memdup_user_nul(ubuf, cnt);
265 mutex_lock(&event_mutex);
266 event_file = event_file_data(file);
267 if (unlikely(!event_file)) {
268 mutex_unlock(&event_mutex);
272 ret = trigger_process_regex(event_file, buf);
273 mutex_unlock(&event_mutex);
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);
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);
305 event_trigger_open(struct inode *inode, struct file *filp)
307 /* Checks for tracefs lockdown */
308 return event_trigger_regex_open(inode, filp);
312 event_trigger_release(struct inode *inode, struct file *file)
314 return event_trigger_regex_release(inode, file);
317 const struct file_operations event_trigger_fops = {
318 .open = event_trigger_open,
320 .write = event_trigger_write,
321 .llseek = tracing_lseek,
322 .release = event_trigger_release,
326 * Currently we only register event commands from __init, so mark this
329 __init int register_event_command(struct event_command *cmd)
331 struct event_command *p;
334 mutex_lock(&trigger_cmd_mutex);
335 list_for_each_entry(p, &trigger_commands, list) {
336 if (strcmp(cmd->name, p->name) == 0) {
341 list_add(&cmd->list, &trigger_commands);
343 mutex_unlock(&trigger_cmd_mutex);
349 * Currently we only unregister event commands from __init, so mark
352 __init int unregister_event_command(struct event_command *cmd)
354 struct event_command *p, *n;
357 mutex_lock(&trigger_cmd_mutex);
358 list_for_each_entry_safe(p, n, &trigger_commands, list) {
359 if (strcmp(cmd->name, p->name) == 0) {
361 list_del_init(&p->list);
366 mutex_unlock(&trigger_cmd_mutex);
372 * event_trigger_print - Generic event_trigger_ops @print implementation
373 * @name: The name of the event trigger
374 * @m: The seq_file being printed to
375 * @data: Trigger-specific data
376 * @filter_str: filter_str to print, if present
378 * Common implementation for event triggers to print themselves.
380 * Usually wrapped by a function that simply sets the @name of the
381 * trigger command and then invokes this.
383 * Return: 0 on success, errno otherwise
386 event_trigger_print(const char *name, struct seq_file *m,
387 void *data, char *filter_str)
389 long count = (long)data;
394 seq_puts(m, ":unlimited");
396 seq_printf(m, ":count=%ld", count);
399 seq_printf(m, " if %s\n", filter_str);
407 * event_trigger_init - Generic event_trigger_ops @init implementation
408 * @ops: The trigger ops associated with the trigger
409 * @data: Trigger-specific data
411 * Common implementation of event trigger initialization.
413 * Usually used directly as the @init method in event trigger
416 * Return: 0 on success, errno otherwise
418 int event_trigger_init(struct event_trigger_ops *ops,
419 struct event_trigger_data *data)
426 * event_trigger_free - Generic event_trigger_ops @free implementation
427 * @ops: The trigger ops associated with the trigger
428 * @data: Trigger-specific data
430 * Common implementation of event trigger de-initialization.
432 * Usually used directly as the @free method in event trigger
436 event_trigger_free(struct event_trigger_ops *ops,
437 struct event_trigger_data *data)
439 if (WARN_ON_ONCE(data->ref <= 0))
444 trigger_data_free(data);
447 int trace_event_trigger_enable_disable(struct trace_event_file *file,
452 if (trigger_enable) {
453 if (atomic_inc_return(&file->tm_ref) > 1)
455 set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
456 ret = trace_event_enable_disable(file, 1, 1);
458 if (atomic_dec_return(&file->tm_ref) > 0)
460 clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
461 ret = trace_event_enable_disable(file, 0, 1);
468 * clear_event_triggers - Clear all triggers associated with a trace array
469 * @tr: The trace array to clear
471 * For each trigger, the triggering event has its tm_ref decremented
472 * via trace_event_trigger_enable_disable(), and any associated event
473 * (in the case of enable/disable_event triggers) will have its sm_ref
474 * decremented via free()->trace_event_enable_disable(). That
475 * combination effectively reverses the soft-mode/trigger state added
476 * by trigger registration.
478 * Must be called with event_mutex held.
481 clear_event_triggers(struct trace_array *tr)
483 struct trace_event_file *file;
485 list_for_each_entry(file, &tr->events, list) {
486 struct event_trigger_data *data, *n;
487 list_for_each_entry_safe(data, n, &file->triggers, list) {
488 trace_event_trigger_enable_disable(file, 0);
489 list_del_rcu(&data->list);
491 data->ops->free(data->ops, data);
497 * update_cond_flag - Set or reset the TRIGGER_COND bit
498 * @file: The trace_event_file associated with the event
500 * If an event has triggers and any of those triggers has a filter or
501 * a post_trigger, trigger invocation needs to be deferred until after
502 * the current event has logged its data, and the event should have
503 * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be
506 void update_cond_flag(struct trace_event_file *file)
508 struct event_trigger_data *data;
509 bool set_cond = false;
511 lockdep_assert_held(&event_mutex);
513 list_for_each_entry(data, &file->triggers, list) {
514 if (data->filter || event_command_post_trigger(data->cmd_ops) ||
515 event_command_needs_rec(data->cmd_ops)) {
522 set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
524 clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
528 * register_trigger - Generic event_command @reg implementation
529 * @glob: The raw string used to register the trigger
530 * @ops: The trigger ops associated with the trigger
531 * @data: Trigger-specific data to associate with the trigger
532 * @file: The trace_event_file associated with the event
534 * Common implementation for event trigger registration.
536 * Usually used directly as the @reg method in event command
539 * Return: 0 on success, errno otherwise
541 static int register_trigger(char *glob, struct event_trigger_ops *ops,
542 struct event_trigger_data *data,
543 struct trace_event_file *file)
545 struct event_trigger_data *test;
548 lockdep_assert_held(&event_mutex);
550 list_for_each_entry(test, &file->triggers, list) {
551 if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) {
557 if (data->ops->init) {
558 ret = data->ops->init(data->ops, data);
563 list_add_rcu(&data->list, &file->triggers);
566 update_cond_flag(file);
567 if (trace_event_trigger_enable_disable(file, 1) < 0) {
568 list_del_rcu(&data->list);
569 update_cond_flag(file);
577 * unregister_trigger - Generic event_command @unreg implementation
578 * @glob: The raw string used to register the trigger
579 * @ops: The trigger ops associated with the trigger
580 * @test: Trigger-specific data used to find the trigger to remove
581 * @file: The trace_event_file associated with the event
583 * Common implementation for event trigger unregistration.
585 * Usually used directly as the @unreg method in event command
588 static void unregister_trigger(char *glob, struct event_trigger_ops *ops,
589 struct event_trigger_data *test,
590 struct trace_event_file *file)
592 struct event_trigger_data *data;
593 bool unregistered = false;
595 lockdep_assert_held(&event_mutex);
597 list_for_each_entry(data, &file->triggers, list) {
598 if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
600 list_del_rcu(&data->list);
601 trace_event_trigger_enable_disable(file, 0);
602 update_cond_flag(file);
607 if (unregistered && data->ops->free)
608 data->ops->free(data->ops, data);
612 * event_trigger_callback - Generic event_command @func implementation
613 * @cmd_ops: The command ops, used for trigger registration
614 * @file: The trace_event_file associated with the event
615 * @glob: The raw string used to register the trigger
616 * @cmd: The cmd portion of the string used to register the trigger
617 * @param: The params portion of the string used to register the trigger
619 * Common implementation for event command parsing and trigger
622 * Usually used directly as the @func method in event command
625 * Return: 0 on success, errno otherwise
628 event_trigger_callback(struct event_command *cmd_ops,
629 struct trace_event_file *file,
630 char *glob, char *cmd, char *param)
632 struct event_trigger_data *trigger_data;
633 struct event_trigger_ops *trigger_ops;
634 char *trigger = NULL;
638 /* separate the trigger from the filter (t:n [if filter]) */
639 if (param && isdigit(param[0])) {
640 trigger = strsep(¶m, " \t");
642 param = skip_spaces(param);
648 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
651 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
655 trigger_data->count = -1;
656 trigger_data->ops = trigger_ops;
657 trigger_data->cmd_ops = cmd_ops;
658 trigger_data->private_data = file;
659 INIT_LIST_HEAD(&trigger_data->list);
660 INIT_LIST_HEAD(&trigger_data->named_list);
662 if (glob[0] == '!') {
663 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
670 number = strsep(&trigger, ":");
677 * We use the callback data field (which is a pointer)
680 ret = kstrtoul(number, 0, &trigger_data->count);
685 if (!param) /* if param is non-empty, it's supposed to be a filter */
688 if (!cmd_ops->set_filter)
691 ret = cmd_ops->set_filter(param, trigger_data, file);
696 /* Up the trigger_data count to make sure reg doesn't free it on failure */
697 event_trigger_init(trigger_ops, trigger_data);
698 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
700 * The above returns on success the # of functions enabled,
701 * but if it didn't find any functions it returns zero.
702 * Consider no functions a failure too.
705 cmd_ops->unreg(glob, trigger_ops, trigger_data, file);
710 /* Down the counter of trigger_data or free it if not used anymore */
711 event_trigger_free(trigger_ops, trigger_data);
716 if (cmd_ops->set_filter)
717 cmd_ops->set_filter(NULL, trigger_data, NULL);
723 * set_trigger_filter - Generic event_command @set_filter implementation
724 * @filter_str: The filter string for the trigger, NULL to remove filter
725 * @trigger_data: Trigger-specific data
726 * @file: The trace_event_file associated with the event
728 * Common implementation for event command filter parsing and filter
731 * Usually used directly as the @set_filter method in event command
734 * Also used to remove a filter (if filter_str = NULL).
736 * Return: 0 on success, errno otherwise
738 int set_trigger_filter(char *filter_str,
739 struct event_trigger_data *trigger_data,
740 struct trace_event_file *file)
742 struct event_trigger_data *data = trigger_data;
743 struct event_filter *filter = NULL, *tmp;
747 if (!filter_str) /* clear the current filter */
750 s = strsep(&filter_str, " \t");
752 if (!strlen(s) || strcmp(s, "if") != 0)
758 /* The filter is for the 'trigger' event, not the triggered event */
759 ret = create_event_filter(file->tr, file->event_call,
760 filter_str, false, &filter);
762 * If create_event_filter() fails, filter still needs to be freed.
763 * Which the calling code will do with data->filter.
766 tmp = rcu_access_pointer(data->filter);
768 rcu_assign_pointer(data->filter, filter);
771 /* Make sure the call is done with the filter */
772 tracepoint_synchronize_unregister();
773 free_event_filter(tmp);
776 kfree(data->filter_str);
777 data->filter_str = NULL;
780 data->filter_str = kstrdup(filter_str, GFP_KERNEL);
781 if (!data->filter_str) {
782 free_event_filter(rcu_access_pointer(data->filter));
791 static LIST_HEAD(named_triggers);
794 * find_named_trigger - Find the common named trigger associated with @name
795 * @name: The name of the set of named triggers to find the common data for
797 * Named triggers are sets of triggers that share a common set of
798 * trigger data. The first named trigger registered with a given name
799 * owns the common trigger data that the others subsequently
800 * registered with the same name will reference. This function
801 * returns the common trigger data associated with that first
802 * registered instance.
804 * Return: the common trigger data for the given named trigger on
805 * success, NULL otherwise.
807 struct event_trigger_data *find_named_trigger(const char *name)
809 struct event_trigger_data *data;
814 list_for_each_entry(data, &named_triggers, named_list) {
815 if (data->named_data)
817 if (strcmp(data->name, name) == 0)
825 * is_named_trigger - determine if a given trigger is a named trigger
826 * @test: The trigger data to test
828 * Return: true if 'test' is a named trigger, false otherwise.
830 bool is_named_trigger(struct event_trigger_data *test)
832 struct event_trigger_data *data;
834 list_for_each_entry(data, &named_triggers, named_list) {
843 * save_named_trigger - save the trigger in the named trigger list
844 * @name: The name of the named trigger set
845 * @data: The trigger data to save
847 * Return: 0 if successful, negative error otherwise.
849 int save_named_trigger(const char *name, struct event_trigger_data *data)
851 data->name = kstrdup(name, GFP_KERNEL);
855 list_add(&data->named_list, &named_triggers);
861 * del_named_trigger - delete a trigger from the named trigger list
862 * @data: The trigger data to delete
864 void del_named_trigger(struct event_trigger_data *data)
869 list_del(&data->named_list);
872 static void __pause_named_trigger(struct event_trigger_data *data, bool pause)
874 struct event_trigger_data *test;
876 list_for_each_entry(test, &named_triggers, named_list) {
877 if (strcmp(test->name, data->name) == 0) {
879 test->paused_tmp = test->paused;
882 test->paused = test->paused_tmp;
889 * pause_named_trigger - Pause all named triggers with the same name
890 * @data: The trigger data of a named trigger to pause
892 * Pauses a named trigger along with all other triggers having the
893 * same name. Because named triggers share a common set of data,
894 * pausing only one is meaningless, so pausing one named trigger needs
895 * to pause all triggers with the same name.
897 void pause_named_trigger(struct event_trigger_data *data)
899 __pause_named_trigger(data, true);
903 * unpause_named_trigger - Un-pause all named triggers with the same name
904 * @data: The trigger data of a named trigger to unpause
906 * Un-pauses a named trigger along with all other triggers having the
907 * same name. Because named triggers share a common set of data,
908 * unpausing only one is meaningless, so unpausing one named trigger
909 * needs to unpause all triggers with the same name.
911 void unpause_named_trigger(struct event_trigger_data *data)
913 __pause_named_trigger(data, false);
917 * set_named_trigger_data - Associate common named trigger data
918 * @data: The trigger data of a named trigger to unpause
920 * Named triggers are sets of triggers that share a common set of
921 * trigger data. The first named trigger registered with a given name
922 * owns the common trigger data that the others subsequently
923 * registered with the same name will reference. This function
924 * associates the common trigger data from the first trigger with the
927 void set_named_trigger_data(struct event_trigger_data *data,
928 struct event_trigger_data *named_data)
930 data->named_data = named_data;
933 struct event_trigger_data *
934 get_named_trigger_data(struct event_trigger_data *data)
936 return data->named_data;
940 traceon_trigger(struct event_trigger_data *data, void *rec,
941 struct ring_buffer_event *event)
943 struct trace_event_file *file = data->private_data;
946 if (tracer_tracing_is_on(file->tr))
949 tracer_tracing_on(file->tr);
960 traceon_count_trigger(struct event_trigger_data *data, void *rec,
961 struct ring_buffer_event *event)
963 struct trace_event_file *file = data->private_data;
966 if (tracer_tracing_is_on(file->tr))
976 if (data->count != -1)
980 tracer_tracing_on(file->tr);
986 traceoff_trigger(struct event_trigger_data *data, void *rec,
987 struct ring_buffer_event *event)
989 struct trace_event_file *file = data->private_data;
992 if (!tracer_tracing_is_on(file->tr))
995 tracer_tracing_off(file->tr);
999 if (!tracing_is_on())
1006 traceoff_count_trigger(struct event_trigger_data *data, void *rec,
1007 struct ring_buffer_event *event)
1009 struct trace_event_file *file = data->private_data;
1012 if (!tracer_tracing_is_on(file->tr))
1015 if (!tracing_is_on())
1022 if (data->count != -1)
1026 tracer_tracing_off(file->tr);
1032 traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1033 struct event_trigger_data *data)
1035 return event_trigger_print("traceon", m, (void *)data->count,
1040 traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1041 struct event_trigger_data *data)
1043 return event_trigger_print("traceoff", m, (void *)data->count,
1047 static struct event_trigger_ops traceon_trigger_ops = {
1048 .func = traceon_trigger,
1049 .print = traceon_trigger_print,
1050 .init = event_trigger_init,
1051 .free = event_trigger_free,
1054 static struct event_trigger_ops traceon_count_trigger_ops = {
1055 .func = traceon_count_trigger,
1056 .print = traceon_trigger_print,
1057 .init = event_trigger_init,
1058 .free = event_trigger_free,
1061 static struct event_trigger_ops traceoff_trigger_ops = {
1062 .func = traceoff_trigger,
1063 .print = traceoff_trigger_print,
1064 .init = event_trigger_init,
1065 .free = event_trigger_free,
1068 static struct event_trigger_ops traceoff_count_trigger_ops = {
1069 .func = traceoff_count_trigger,
1070 .print = traceoff_trigger_print,
1071 .init = event_trigger_init,
1072 .free = event_trigger_free,
1075 static struct event_trigger_ops *
1076 onoff_get_trigger_ops(char *cmd, char *param)
1078 struct event_trigger_ops *ops;
1080 /* we register both traceon and traceoff to this callback */
1081 if (strcmp(cmd, "traceon") == 0)
1082 ops = param ? &traceon_count_trigger_ops :
1083 &traceon_trigger_ops;
1085 ops = param ? &traceoff_count_trigger_ops :
1086 &traceoff_trigger_ops;
1091 static struct event_command trigger_traceon_cmd = {
1093 .trigger_type = ETT_TRACE_ONOFF,
1094 .func = event_trigger_callback,
1095 .reg = register_trigger,
1096 .unreg = unregister_trigger,
1097 .get_trigger_ops = onoff_get_trigger_ops,
1098 .set_filter = set_trigger_filter,
1101 static struct event_command trigger_traceoff_cmd = {
1103 .trigger_type = ETT_TRACE_ONOFF,
1104 .flags = EVENT_CMD_FL_POST_TRIGGER,
1105 .func = event_trigger_callback,
1106 .reg = register_trigger,
1107 .unreg = unregister_trigger,
1108 .get_trigger_ops = onoff_get_trigger_ops,
1109 .set_filter = set_trigger_filter,
1112 #ifdef CONFIG_TRACER_SNAPSHOT
1114 snapshot_trigger(struct event_trigger_data *data, void *rec,
1115 struct ring_buffer_event *event)
1117 struct trace_event_file *file = data->private_data;
1120 tracing_snapshot_instance(file->tr);
1126 snapshot_count_trigger(struct event_trigger_data *data, void *rec,
1127 struct ring_buffer_event *event)
1132 if (data->count != -1)
1135 snapshot_trigger(data, rec, event);
1139 register_snapshot_trigger(char *glob, struct event_trigger_ops *ops,
1140 struct event_trigger_data *data,
1141 struct trace_event_file *file)
1143 if (tracing_alloc_snapshot_instance(file->tr) != 0)
1146 return register_trigger(glob, ops, data, file);
1150 snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1151 struct event_trigger_data *data)
1153 return event_trigger_print("snapshot", m, (void *)data->count,
1157 static struct event_trigger_ops snapshot_trigger_ops = {
1158 .func = snapshot_trigger,
1159 .print = snapshot_trigger_print,
1160 .init = event_trigger_init,
1161 .free = event_trigger_free,
1164 static struct event_trigger_ops snapshot_count_trigger_ops = {
1165 .func = snapshot_count_trigger,
1166 .print = snapshot_trigger_print,
1167 .init = event_trigger_init,
1168 .free = event_trigger_free,
1171 static struct event_trigger_ops *
1172 snapshot_get_trigger_ops(char *cmd, char *param)
1174 return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
1177 static struct event_command trigger_snapshot_cmd = {
1179 .trigger_type = ETT_SNAPSHOT,
1180 .func = event_trigger_callback,
1181 .reg = register_snapshot_trigger,
1182 .unreg = unregister_trigger,
1183 .get_trigger_ops = snapshot_get_trigger_ops,
1184 .set_filter = set_trigger_filter,
1187 static __init int register_trigger_snapshot_cmd(void)
1191 ret = register_event_command(&trigger_snapshot_cmd);
1197 static __init int register_trigger_snapshot_cmd(void) { return 0; }
1198 #endif /* CONFIG_TRACER_SNAPSHOT */
1200 #ifdef CONFIG_STACKTRACE
1201 #ifdef CONFIG_UNWINDER_ORC
1203 * event_triggers_post_call()
1204 * trace_event_raw_event_xxx()
1206 # define STACK_SKIP 2
1210 * stacktrace_trigger()
1211 * event_triggers_post_call()
1212 * trace_event_buffer_commit()
1213 * trace_event_raw_event_xxx()
1215 #define STACK_SKIP 4
1219 stacktrace_trigger(struct event_trigger_data *data, void *rec,
1220 struct ring_buffer_event *event)
1222 struct trace_event_file *file = data->private_data;
1223 unsigned long flags;
1226 local_save_flags(flags);
1227 __trace_stack(file->tr, flags, STACK_SKIP, preempt_count());
1229 trace_dump_stack(STACK_SKIP);
1233 stacktrace_count_trigger(struct event_trigger_data *data, void *rec,
1234 struct ring_buffer_event *event)
1239 if (data->count != -1)
1242 stacktrace_trigger(data, rec, event);
1246 stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1247 struct event_trigger_data *data)
1249 return event_trigger_print("stacktrace", m, (void *)data->count,
1253 static struct event_trigger_ops stacktrace_trigger_ops = {
1254 .func = stacktrace_trigger,
1255 .print = stacktrace_trigger_print,
1256 .init = event_trigger_init,
1257 .free = event_trigger_free,
1260 static struct event_trigger_ops stacktrace_count_trigger_ops = {
1261 .func = stacktrace_count_trigger,
1262 .print = stacktrace_trigger_print,
1263 .init = event_trigger_init,
1264 .free = event_trigger_free,
1267 static struct event_trigger_ops *
1268 stacktrace_get_trigger_ops(char *cmd, char *param)
1270 return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
1273 static struct event_command trigger_stacktrace_cmd = {
1274 .name = "stacktrace",
1275 .trigger_type = ETT_STACKTRACE,
1276 .flags = EVENT_CMD_FL_POST_TRIGGER,
1277 .func = event_trigger_callback,
1278 .reg = register_trigger,
1279 .unreg = unregister_trigger,
1280 .get_trigger_ops = stacktrace_get_trigger_ops,
1281 .set_filter = set_trigger_filter,
1284 static __init int register_trigger_stacktrace_cmd(void)
1288 ret = register_event_command(&trigger_stacktrace_cmd);
1294 static __init int register_trigger_stacktrace_cmd(void) { return 0; }
1295 #endif /* CONFIG_STACKTRACE */
1297 static __init void unregister_trigger_traceon_traceoff_cmds(void)
1299 unregister_event_command(&trigger_traceon_cmd);
1300 unregister_event_command(&trigger_traceoff_cmd);
1304 event_enable_trigger(struct event_trigger_data *data, void *rec,
1305 struct ring_buffer_event *event)
1307 struct enable_trigger_data *enable_data = data->private_data;
1309 if (enable_data->enable)
1310 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1312 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1316 event_enable_count_trigger(struct event_trigger_data *data, void *rec,
1317 struct ring_buffer_event *event)
1319 struct enable_trigger_data *enable_data = data->private_data;
1324 /* Skip if the event is in a state we want to switch to */
1325 if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
1328 if (data->count != -1)
1331 event_enable_trigger(data, rec, event);
1334 int event_enable_trigger_print(struct seq_file *m,
1335 struct event_trigger_ops *ops,
1336 struct event_trigger_data *data)
1338 struct enable_trigger_data *enable_data = data->private_data;
1340 seq_printf(m, "%s:%s:%s",
1342 (enable_data->enable ? ENABLE_HIST_STR : DISABLE_HIST_STR) :
1343 (enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR),
1344 enable_data->file->event_call->class->system,
1345 trace_event_name(enable_data->file->event_call));
1347 if (data->count == -1)
1348 seq_puts(m, ":unlimited");
1350 seq_printf(m, ":count=%ld", data->count);
1352 if (data->filter_str)
1353 seq_printf(m, " if %s\n", data->filter_str);
1360 void event_enable_trigger_free(struct event_trigger_ops *ops,
1361 struct event_trigger_data *data)
1363 struct enable_trigger_data *enable_data = data->private_data;
1365 if (WARN_ON_ONCE(data->ref <= 0))
1370 /* Remove the SOFT_MODE flag */
1371 trace_event_enable_disable(enable_data->file, 0, 1);
1372 module_put(enable_data->file->event_call->mod);
1373 trigger_data_free(data);
1378 static struct event_trigger_ops event_enable_trigger_ops = {
1379 .func = event_enable_trigger,
1380 .print = event_enable_trigger_print,
1381 .init = event_trigger_init,
1382 .free = event_enable_trigger_free,
1385 static struct event_trigger_ops event_enable_count_trigger_ops = {
1386 .func = event_enable_count_trigger,
1387 .print = event_enable_trigger_print,
1388 .init = event_trigger_init,
1389 .free = event_enable_trigger_free,
1392 static struct event_trigger_ops event_disable_trigger_ops = {
1393 .func = event_enable_trigger,
1394 .print = event_enable_trigger_print,
1395 .init = event_trigger_init,
1396 .free = event_enable_trigger_free,
1399 static struct event_trigger_ops event_disable_count_trigger_ops = {
1400 .func = event_enable_count_trigger,
1401 .print = event_enable_trigger_print,
1402 .init = event_trigger_init,
1403 .free = event_enable_trigger_free,
1406 int event_enable_trigger_func(struct event_command *cmd_ops,
1407 struct trace_event_file *file,
1408 char *glob, char *cmd, char *param)
1410 struct trace_event_file *event_enable_file;
1411 struct enable_trigger_data *enable_data;
1412 struct event_trigger_data *trigger_data;
1413 struct event_trigger_ops *trigger_ops;
1414 struct trace_array *tr = file->tr;
1426 /* separate the trigger from the filter (s:e:n [if filter]) */
1427 trigger = strsep(¶m, " \t");
1431 param = skip_spaces(param);
1436 system = strsep(&trigger, ":");
1440 event = strsep(&trigger, ":");
1443 event_enable_file = find_event_file(tr, system, event);
1444 if (!event_enable_file)
1447 #ifdef CONFIG_HIST_TRIGGERS
1448 hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) ||
1449 (strcmp(cmd, DISABLE_HIST_STR) == 0));
1451 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1452 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1454 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1456 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
1459 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
1463 enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
1465 kfree(trigger_data);
1469 trigger_data->count = -1;
1470 trigger_data->ops = trigger_ops;
1471 trigger_data->cmd_ops = cmd_ops;
1472 INIT_LIST_HEAD(&trigger_data->list);
1473 RCU_INIT_POINTER(trigger_data->filter, NULL);
1475 enable_data->hist = hist;
1476 enable_data->enable = enable;
1477 enable_data->file = event_enable_file;
1478 trigger_data->private_data = enable_data;
1480 if (glob[0] == '!') {
1481 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
1482 kfree(trigger_data);
1488 /* Up the trigger_data count to make sure nothing frees it on failure */
1489 event_trigger_init(trigger_ops, trigger_data);
1492 number = strsep(&trigger, ":");
1495 if (!strlen(number))
1499 * We use the callback data field (which is a pointer)
1502 ret = kstrtoul(number, 0, &trigger_data->count);
1507 if (!param) /* if param is non-empty, it's supposed to be a filter */
1510 if (!cmd_ops->set_filter)
1513 ret = cmd_ops->set_filter(param, trigger_data, file);
1518 /* Don't let event modules unload while probe registered */
1519 ret = try_module_get(event_enable_file->event_call->mod);
1525 ret = trace_event_enable_disable(event_enable_file, 1, 1);
1528 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1530 * The above returns on success the # of functions enabled,
1531 * but if it didn't find any functions it returns zero.
1532 * Consider no functions a failure too.
1539 /* Just return zero, not the number of enabled functions */
1541 event_trigger_free(trigger_ops, trigger_data);
1546 trace_event_enable_disable(event_enable_file, 0, 1);
1548 module_put(event_enable_file->event_call->mod);
1550 if (cmd_ops->set_filter)
1551 cmd_ops->set_filter(NULL, trigger_data, NULL);
1552 event_trigger_free(trigger_ops, trigger_data);
1557 int event_enable_register_trigger(char *glob,
1558 struct event_trigger_ops *ops,
1559 struct event_trigger_data *data,
1560 struct trace_event_file *file)
1562 struct enable_trigger_data *enable_data = data->private_data;
1563 struct enable_trigger_data *test_enable_data;
1564 struct event_trigger_data *test;
1567 lockdep_assert_held(&event_mutex);
1569 list_for_each_entry(test, &file->triggers, list) {
1570 test_enable_data = test->private_data;
1571 if (test_enable_data &&
1572 (test->cmd_ops->trigger_type ==
1573 data->cmd_ops->trigger_type) &&
1574 (test_enable_data->file == enable_data->file)) {
1580 if (data->ops->init) {
1581 ret = data->ops->init(data->ops, data);
1586 list_add_rcu(&data->list, &file->triggers);
1589 update_cond_flag(file);
1590 if (trace_event_trigger_enable_disable(file, 1) < 0) {
1591 list_del_rcu(&data->list);
1592 update_cond_flag(file);
1599 void event_enable_unregister_trigger(char *glob,
1600 struct event_trigger_ops *ops,
1601 struct event_trigger_data *test,
1602 struct trace_event_file *file)
1604 struct enable_trigger_data *test_enable_data = test->private_data;
1605 struct enable_trigger_data *enable_data;
1606 struct event_trigger_data *data;
1607 bool unregistered = false;
1609 lockdep_assert_held(&event_mutex);
1611 list_for_each_entry(data, &file->triggers, list) {
1612 enable_data = data->private_data;
1614 (data->cmd_ops->trigger_type ==
1615 test->cmd_ops->trigger_type) &&
1616 (enable_data->file == test_enable_data->file)) {
1617 unregistered = true;
1618 list_del_rcu(&data->list);
1619 trace_event_trigger_enable_disable(file, 0);
1620 update_cond_flag(file);
1625 if (unregistered && data->ops->free)
1626 data->ops->free(data->ops, data);
1629 static struct event_trigger_ops *
1630 event_enable_get_trigger_ops(char *cmd, char *param)
1632 struct event_trigger_ops *ops;
1635 #ifdef CONFIG_HIST_TRIGGERS
1636 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1637 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1639 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1642 ops = param ? &event_enable_count_trigger_ops :
1643 &event_enable_trigger_ops;
1645 ops = param ? &event_disable_count_trigger_ops :
1646 &event_disable_trigger_ops;
1651 static struct event_command trigger_enable_cmd = {
1652 .name = ENABLE_EVENT_STR,
1653 .trigger_type = ETT_EVENT_ENABLE,
1654 .func = event_enable_trigger_func,
1655 .reg = event_enable_register_trigger,
1656 .unreg = event_enable_unregister_trigger,
1657 .get_trigger_ops = event_enable_get_trigger_ops,
1658 .set_filter = set_trigger_filter,
1661 static struct event_command trigger_disable_cmd = {
1662 .name = DISABLE_EVENT_STR,
1663 .trigger_type = ETT_EVENT_ENABLE,
1664 .func = event_enable_trigger_func,
1665 .reg = event_enable_register_trigger,
1666 .unreg = event_enable_unregister_trigger,
1667 .get_trigger_ops = event_enable_get_trigger_ops,
1668 .set_filter = set_trigger_filter,
1671 static __init void unregister_trigger_enable_disable_cmds(void)
1673 unregister_event_command(&trigger_enable_cmd);
1674 unregister_event_command(&trigger_disable_cmd);
1677 static __init int register_trigger_enable_disable_cmds(void)
1681 ret = register_event_command(&trigger_enable_cmd);
1682 if (WARN_ON(ret < 0))
1684 ret = register_event_command(&trigger_disable_cmd);
1685 if (WARN_ON(ret < 0))
1686 unregister_trigger_enable_disable_cmds();
1691 static __init int register_trigger_traceon_traceoff_cmds(void)
1695 ret = register_event_command(&trigger_traceon_cmd);
1696 if (WARN_ON(ret < 0))
1698 ret = register_event_command(&trigger_traceoff_cmd);
1699 if (WARN_ON(ret < 0))
1700 unregister_trigger_traceon_traceoff_cmds();
1705 __init int register_trigger_cmds(void)
1707 register_trigger_traceon_traceoff_cmds();
1708 register_trigger_snapshot_cmd();
1709 register_trigger_stacktrace_cmd();
1710 register_trigger_enable_disable_cmds();
1711 register_trigger_hist_enable_disable_cmds();
1712 register_trigger_hist_cmd();