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/module.h>
9 #include <linux/ctype.h>
10 #include <linux/mutex.h>
11 #include <linux/slab.h>
12 #include <linux/rculist.h>
16 static LIST_HEAD(trigger_commands);
17 static DEFINE_MUTEX(trigger_cmd_mutex);
19 void trigger_data_free(struct event_trigger_data *data)
21 if (data->cmd_ops->set_filter)
22 data->cmd_ops->set_filter(NULL, data, NULL);
24 /* make sure current triggers exit before free */
25 tracepoint_synchronize_unregister();
31 * event_triggers_call - Call triggers associated with a trace event
32 * @file: The trace_event_file associated with the event
33 * @rec: The trace entry for the event, NULL for unconditional invocation
35 * For each trigger associated with an event, invoke the trigger
36 * function registered with the associated trigger command. If rec is
37 * non-NULL, it means that the trigger requires further processing and
38 * shouldn't be unconditionally invoked. If rec is non-NULL and the
39 * trigger has a filter associated with it, rec will checked against
40 * the filter and if the record matches the trigger will be invoked.
41 * If the trigger is a 'post_trigger', meaning it shouldn't be invoked
42 * in any case until the current event is written, the trigger
43 * function isn't invoked but the bit associated with the deferred
44 * trigger is set in the return value.
46 * Returns an enum event_trigger_type value containing a set bit for
47 * any trigger that should be deferred, ETT_NONE if nothing to defer.
49 * Called from tracepoint handlers (with rcu_read_lock_sched() held).
51 * Return: an enum event_trigger_type value containing a set bit for
52 * any trigger that should be deferred, ETT_NONE if nothing to defer.
54 enum event_trigger_type
55 event_triggers_call(struct trace_event_file *file, void *rec,
56 struct ring_buffer_event *event)
58 struct event_trigger_data *data;
59 enum event_trigger_type tt = ETT_NONE;
60 struct event_filter *filter;
62 if (list_empty(&file->triggers))
65 list_for_each_entry_rcu(data, &file->triggers, list) {
69 data->ops->func(data, rec, event);
72 filter = rcu_dereference_sched(data->filter);
73 if (filter && !filter_match_preds(filter, rec))
75 if (event_command_post_trigger(data->cmd_ops)) {
76 tt |= data->cmd_ops->trigger_type;
79 data->ops->func(data, rec, event);
83 EXPORT_SYMBOL_GPL(event_triggers_call);
86 * event_triggers_post_call - Call 'post_triggers' for a trace event
87 * @file: The trace_event_file associated with the event
88 * @tt: enum event_trigger_type containing a set bit for each trigger to invoke
90 * For each trigger associated with an event, invoke the trigger
91 * function registered with the associated trigger command, if the
92 * corresponding bit is set in the tt enum passed into this function.
93 * See @event_triggers_call for details on how those bits are set.
95 * Called from tracepoint handlers (with rcu_read_lock_sched() held).
98 event_triggers_post_call(struct trace_event_file *file,
99 enum event_trigger_type tt)
101 struct event_trigger_data *data;
103 list_for_each_entry_rcu(data, &file->triggers, list) {
106 if (data->cmd_ops->trigger_type & tt)
107 data->ops->func(data, NULL, NULL);
110 EXPORT_SYMBOL_GPL(event_triggers_post_call);
112 #define SHOW_AVAILABLE_TRIGGERS (void *)(1UL)
114 static void *trigger_next(struct seq_file *m, void *t, loff_t *pos)
116 struct trace_event_file *event_file = event_file_data(m->private);
118 if (t == SHOW_AVAILABLE_TRIGGERS)
121 return seq_list_next(t, &event_file->triggers, pos);
124 static void *trigger_start(struct seq_file *m, loff_t *pos)
126 struct trace_event_file *event_file;
128 /* ->stop() is called even if ->start() fails */
129 mutex_lock(&event_mutex);
130 event_file = event_file_data(m->private);
131 if (unlikely(!event_file))
132 return ERR_PTR(-ENODEV);
134 if (list_empty(&event_file->triggers))
135 return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL;
137 return seq_list_start(&event_file->triggers, *pos);
140 static void trigger_stop(struct seq_file *m, void *t)
142 mutex_unlock(&event_mutex);
145 static int trigger_show(struct seq_file *m, void *v)
147 struct event_trigger_data *data;
148 struct event_command *p;
150 if (v == SHOW_AVAILABLE_TRIGGERS) {
151 seq_puts(m, "# Available triggers:\n");
153 mutex_lock(&trigger_cmd_mutex);
154 list_for_each_entry_reverse(p, &trigger_commands, list)
155 seq_printf(m, " %s", p->name);
157 mutex_unlock(&trigger_cmd_mutex);
161 data = list_entry(v, struct event_trigger_data, list);
162 data->ops->print(m, data->ops, data);
167 static const struct seq_operations event_triggers_seq_ops = {
168 .start = trigger_start,
169 .next = trigger_next,
170 .stop = trigger_stop,
171 .show = trigger_show,
174 static int event_trigger_regex_open(struct inode *inode, struct file *file)
178 mutex_lock(&event_mutex);
180 if (unlikely(!event_file_data(file))) {
181 mutex_unlock(&event_mutex);
185 if ((file->f_mode & FMODE_WRITE) &&
186 (file->f_flags & O_TRUNC)) {
187 struct trace_event_file *event_file;
188 struct event_command *p;
190 event_file = event_file_data(file);
192 list_for_each_entry(p, &trigger_commands, list) {
194 p->unreg_all(event_file);
198 if (file->f_mode & FMODE_READ) {
199 ret = seq_open(file, &event_triggers_seq_ops);
201 struct seq_file *m = file->private_data;
206 mutex_unlock(&event_mutex);
211 static int trigger_process_regex(struct trace_event_file *file, char *buff)
213 char *command, *next = buff;
214 struct event_command *p;
217 command = strsep(&next, ": \t");
218 command = (command[0] != '!') ? command : command + 1;
220 mutex_lock(&trigger_cmd_mutex);
221 list_for_each_entry(p, &trigger_commands, list) {
222 if (strcmp(p->name, command) == 0) {
223 ret = p->func(p, file, buff, command, next);
228 mutex_unlock(&trigger_cmd_mutex);
233 static ssize_t event_trigger_regex_write(struct file *file,
234 const char __user *ubuf,
235 size_t cnt, loff_t *ppos)
237 struct trace_event_file *event_file;
244 if (cnt >= PAGE_SIZE)
247 buf = memdup_user_nul(ubuf, cnt);
253 mutex_lock(&event_mutex);
254 event_file = event_file_data(file);
255 if (unlikely(!event_file)) {
256 mutex_unlock(&event_mutex);
260 ret = trigger_process_regex(event_file, buf);
261 mutex_unlock(&event_mutex);
273 static int event_trigger_regex_release(struct inode *inode, struct file *file)
275 mutex_lock(&event_mutex);
277 if (file->f_mode & FMODE_READ)
278 seq_release(inode, file);
280 mutex_unlock(&event_mutex);
286 event_trigger_write(struct file *filp, const char __user *ubuf,
287 size_t cnt, loff_t *ppos)
289 return event_trigger_regex_write(filp, ubuf, cnt, ppos);
293 event_trigger_open(struct inode *inode, struct file *filp)
295 return event_trigger_regex_open(inode, filp);
299 event_trigger_release(struct inode *inode, struct file *file)
301 return event_trigger_regex_release(inode, file);
304 const struct file_operations event_trigger_fops = {
305 .open = event_trigger_open,
307 .write = event_trigger_write,
308 .llseek = tracing_lseek,
309 .release = event_trigger_release,
313 * Currently we only register event commands from __init, so mark this
316 __init int register_event_command(struct event_command *cmd)
318 struct event_command *p;
321 mutex_lock(&trigger_cmd_mutex);
322 list_for_each_entry(p, &trigger_commands, list) {
323 if (strcmp(cmd->name, p->name) == 0) {
328 list_add(&cmd->list, &trigger_commands);
330 mutex_unlock(&trigger_cmd_mutex);
336 * Currently we only unregister event commands from __init, so mark
339 __init int unregister_event_command(struct event_command *cmd)
341 struct event_command *p, *n;
344 mutex_lock(&trigger_cmd_mutex);
345 list_for_each_entry_safe(p, n, &trigger_commands, list) {
346 if (strcmp(cmd->name, p->name) == 0) {
348 list_del_init(&p->list);
353 mutex_unlock(&trigger_cmd_mutex);
359 * event_trigger_print - Generic event_trigger_ops @print implementation
360 * @name: The name of the event trigger
361 * @m: The seq_file being printed to
362 * @data: Trigger-specific data
363 * @filter_str: filter_str to print, if present
365 * Common implementation for event triggers to print themselves.
367 * Usually wrapped by a function that simply sets the @name of the
368 * trigger command and then invokes this.
370 * Return: 0 on success, errno otherwise
373 event_trigger_print(const char *name, struct seq_file *m,
374 void *data, char *filter_str)
376 long count = (long)data;
381 seq_puts(m, ":unlimited");
383 seq_printf(m, ":count=%ld", count);
386 seq_printf(m, " if %s\n", filter_str);
394 * event_trigger_init - Generic event_trigger_ops @init implementation
395 * @ops: The trigger ops associated with the trigger
396 * @data: Trigger-specific data
398 * Common implementation of event trigger initialization.
400 * Usually used directly as the @init method in event trigger
403 * Return: 0 on success, errno otherwise
405 int event_trigger_init(struct event_trigger_ops *ops,
406 struct event_trigger_data *data)
413 * event_trigger_free - Generic event_trigger_ops @free implementation
414 * @ops: The trigger ops associated with the trigger
415 * @data: Trigger-specific data
417 * Common implementation of event trigger de-initialization.
419 * Usually used directly as the @free method in event trigger
423 event_trigger_free(struct event_trigger_ops *ops,
424 struct event_trigger_data *data)
426 if (WARN_ON_ONCE(data->ref <= 0))
431 trigger_data_free(data);
434 int trace_event_trigger_enable_disable(struct trace_event_file *file,
439 if (trigger_enable) {
440 if (atomic_inc_return(&file->tm_ref) > 1)
442 set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
443 ret = trace_event_enable_disable(file, 1, 1);
445 if (atomic_dec_return(&file->tm_ref) > 0)
447 clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
448 ret = trace_event_enable_disable(file, 0, 1);
455 * clear_event_triggers - Clear all triggers associated with a trace array
456 * @tr: The trace array to clear
458 * For each trigger, the triggering event has its tm_ref decremented
459 * via trace_event_trigger_enable_disable(), and any associated event
460 * (in the case of enable/disable_event triggers) will have its sm_ref
461 * decremented via free()->trace_event_enable_disable(). That
462 * combination effectively reverses the soft-mode/trigger state added
463 * by trigger registration.
465 * Must be called with event_mutex held.
468 clear_event_triggers(struct trace_array *tr)
470 struct trace_event_file *file;
472 list_for_each_entry(file, &tr->events, list) {
473 struct event_trigger_data *data, *n;
474 list_for_each_entry_safe(data, n, &file->triggers, list) {
475 trace_event_trigger_enable_disable(file, 0);
476 list_del_rcu(&data->list);
478 data->ops->free(data->ops, data);
484 * update_cond_flag - Set or reset the TRIGGER_COND bit
485 * @file: The trace_event_file associated with the event
487 * If an event has triggers and any of those triggers has a filter or
488 * a post_trigger, trigger invocation needs to be deferred until after
489 * the current event has logged its data, and the event should have
490 * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be
493 void update_cond_flag(struct trace_event_file *file)
495 struct event_trigger_data *data;
496 bool set_cond = false;
498 list_for_each_entry_rcu(data, &file->triggers, list) {
499 if (data->filter || event_command_post_trigger(data->cmd_ops) ||
500 event_command_needs_rec(data->cmd_ops)) {
507 set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
509 clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
513 * register_trigger - Generic event_command @reg implementation
514 * @glob: The raw string used to register the trigger
515 * @ops: The trigger ops associated with the trigger
516 * @data: Trigger-specific data to associate with the trigger
517 * @file: The trace_event_file associated with the event
519 * Common implementation for event trigger registration.
521 * Usually used directly as the @reg method in event command
524 * Return: 0 on success, errno otherwise
526 static int register_trigger(char *glob, struct event_trigger_ops *ops,
527 struct event_trigger_data *data,
528 struct trace_event_file *file)
530 struct event_trigger_data *test;
533 list_for_each_entry_rcu(test, &file->triggers, list) {
534 if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) {
540 if (data->ops->init) {
541 ret = data->ops->init(data->ops, data);
546 list_add_rcu(&data->list, &file->triggers);
549 update_cond_flag(file);
550 if (trace_event_trigger_enable_disable(file, 1) < 0) {
551 list_del_rcu(&data->list);
552 update_cond_flag(file);
560 * unregister_trigger - Generic event_command @unreg implementation
561 * @glob: The raw string used to register the trigger
562 * @ops: The trigger ops associated with the trigger
563 * @test: Trigger-specific data used to find the trigger to remove
564 * @file: The trace_event_file associated with the event
566 * Common implementation for event trigger unregistration.
568 * Usually used directly as the @unreg method in event command
571 static void unregister_trigger(char *glob, struct event_trigger_ops *ops,
572 struct event_trigger_data *test,
573 struct trace_event_file *file)
575 struct event_trigger_data *data;
576 bool unregistered = false;
578 list_for_each_entry_rcu(data, &file->triggers, list) {
579 if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
581 list_del_rcu(&data->list);
582 trace_event_trigger_enable_disable(file, 0);
583 update_cond_flag(file);
588 if (unregistered && data->ops->free)
589 data->ops->free(data->ops, data);
593 * event_trigger_callback - Generic event_command @func implementation
594 * @cmd_ops: The command ops, used for trigger registration
595 * @file: The trace_event_file associated with the event
596 * @glob: The raw string used to register the trigger
597 * @cmd: The cmd portion of the string used to register the trigger
598 * @param: The params portion of the string used to register the trigger
600 * Common implementation for event command parsing and trigger
603 * Usually used directly as the @func method in event command
606 * Return: 0 on success, errno otherwise
609 event_trigger_callback(struct event_command *cmd_ops,
610 struct trace_event_file *file,
611 char *glob, char *cmd, char *param)
613 struct event_trigger_data *trigger_data;
614 struct event_trigger_ops *trigger_ops;
615 char *trigger = NULL;
619 /* separate the trigger from the filter (t:n [if filter]) */
620 if (param && isdigit(param[0]))
621 trigger = strsep(¶m, " \t");
623 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
626 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
630 trigger_data->count = -1;
631 trigger_data->ops = trigger_ops;
632 trigger_data->cmd_ops = cmd_ops;
633 trigger_data->private_data = file;
634 INIT_LIST_HEAD(&trigger_data->list);
635 INIT_LIST_HEAD(&trigger_data->named_list);
637 if (glob[0] == '!') {
638 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
645 number = strsep(&trigger, ":");
652 * We use the callback data field (which is a pointer)
655 ret = kstrtoul(number, 0, &trigger_data->count);
660 if (!param) /* if param is non-empty, it's supposed to be a filter */
663 if (!cmd_ops->set_filter)
666 ret = cmd_ops->set_filter(param, trigger_data, file);
671 /* Up the trigger_data count to make sure reg doesn't free it on failure */
672 event_trigger_init(trigger_ops, trigger_data);
673 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
675 * The above returns on success the # of functions enabled,
676 * but if it didn't find any functions it returns zero.
677 * Consider no functions a failure too.
680 cmd_ops->unreg(glob, trigger_ops, trigger_data, file);
685 /* Down the counter of trigger_data or free it if not used anymore */
686 event_trigger_free(trigger_ops, trigger_data);
691 if (cmd_ops->set_filter)
692 cmd_ops->set_filter(NULL, trigger_data, NULL);
698 * set_trigger_filter - Generic event_command @set_filter implementation
699 * @filter_str: The filter string for the trigger, NULL to remove filter
700 * @trigger_data: Trigger-specific data
701 * @file: The trace_event_file associated with the event
703 * Common implementation for event command filter parsing and filter
706 * Usually used directly as the @set_filter method in event command
709 * Also used to remove a filter (if filter_str = NULL).
711 * Return: 0 on success, errno otherwise
713 int set_trigger_filter(char *filter_str,
714 struct event_trigger_data *trigger_data,
715 struct trace_event_file *file)
717 struct event_trigger_data *data = trigger_data;
718 struct event_filter *filter = NULL, *tmp;
722 if (!filter_str) /* clear the current filter */
725 s = strsep(&filter_str, " \t");
727 if (!strlen(s) || strcmp(s, "if") != 0)
733 /* The filter is for the 'trigger' event, not the triggered event */
734 ret = create_event_filter(file->event_call, filter_str, false, &filter);
738 tmp = rcu_access_pointer(data->filter);
740 rcu_assign_pointer(data->filter, filter);
743 /* Make sure the call is done with the filter */
744 tracepoint_synchronize_unregister();
745 free_event_filter(tmp);
748 kfree(data->filter_str);
749 data->filter_str = NULL;
752 data->filter_str = kstrdup(filter_str, GFP_KERNEL);
753 if (!data->filter_str) {
754 free_event_filter(rcu_access_pointer(data->filter));
763 static LIST_HEAD(named_triggers);
766 * find_named_trigger - Find the common named trigger associated with @name
767 * @name: The name of the set of named triggers to find the common data for
769 * Named triggers are sets of triggers that share a common set of
770 * trigger data. The first named trigger registered with a given name
771 * owns the common trigger data that the others subsequently
772 * registered with the same name will reference. This function
773 * returns the common trigger data associated with that first
774 * registered instance.
776 * Return: the common trigger data for the given named trigger on
777 * success, NULL otherwise.
779 struct event_trigger_data *find_named_trigger(const char *name)
781 struct event_trigger_data *data;
786 list_for_each_entry(data, &named_triggers, named_list) {
787 if (data->named_data)
789 if (strcmp(data->name, name) == 0)
797 * is_named_trigger - determine if a given trigger is a named trigger
798 * @test: The trigger data to test
800 * Return: true if 'test' is a named trigger, false otherwise.
802 bool is_named_trigger(struct event_trigger_data *test)
804 struct event_trigger_data *data;
806 list_for_each_entry(data, &named_triggers, named_list) {
815 * save_named_trigger - save the trigger in the named trigger list
816 * @name: The name of the named trigger set
817 * @data: The trigger data to save
819 * Return: 0 if successful, negative error otherwise.
821 int save_named_trigger(const char *name, struct event_trigger_data *data)
823 data->name = kstrdup(name, GFP_KERNEL);
827 list_add(&data->named_list, &named_triggers);
833 * del_named_trigger - delete a trigger from the named trigger list
834 * @data: The trigger data to delete
836 void del_named_trigger(struct event_trigger_data *data)
841 list_del(&data->named_list);
844 static void __pause_named_trigger(struct event_trigger_data *data, bool pause)
846 struct event_trigger_data *test;
848 list_for_each_entry(test, &named_triggers, named_list) {
849 if (strcmp(test->name, data->name) == 0) {
851 test->paused_tmp = test->paused;
854 test->paused = test->paused_tmp;
861 * pause_named_trigger - Pause all named triggers with the same name
862 * @data: The trigger data of a named trigger to pause
864 * Pauses a named trigger along with all other triggers having the
865 * same name. Because named triggers share a common set of data,
866 * pausing only one is meaningless, so pausing one named trigger needs
867 * to pause all triggers with the same name.
869 void pause_named_trigger(struct event_trigger_data *data)
871 __pause_named_trigger(data, true);
875 * unpause_named_trigger - Un-pause all named triggers with the same name
876 * @data: The trigger data of a named trigger to unpause
878 * Un-pauses a named trigger along with all other triggers having the
879 * same name. Because named triggers share a common set of data,
880 * unpausing only one is meaningless, so unpausing one named trigger
881 * needs to unpause all triggers with the same name.
883 void unpause_named_trigger(struct event_trigger_data *data)
885 __pause_named_trigger(data, false);
889 * set_named_trigger_data - Associate common named trigger data
890 * @data: The trigger data of a named trigger to unpause
892 * Named triggers are sets of triggers that share a common set of
893 * trigger data. The first named trigger registered with a given name
894 * owns the common trigger data that the others subsequently
895 * registered with the same name will reference. This function
896 * associates the common trigger data from the first trigger with the
899 void set_named_trigger_data(struct event_trigger_data *data,
900 struct event_trigger_data *named_data)
902 data->named_data = named_data;
905 struct event_trigger_data *
906 get_named_trigger_data(struct event_trigger_data *data)
908 return data->named_data;
912 traceon_trigger(struct event_trigger_data *data, void *rec,
913 struct ring_buffer_event *event)
922 traceon_count_trigger(struct event_trigger_data *data, void *rec,
923 struct ring_buffer_event *event)
931 if (data->count != -1)
938 traceoff_trigger(struct event_trigger_data *data, void *rec,
939 struct ring_buffer_event *event)
941 if (!tracing_is_on())
948 traceoff_count_trigger(struct event_trigger_data *data, void *rec,
949 struct ring_buffer_event *event)
951 if (!tracing_is_on())
957 if (data->count != -1)
964 traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
965 struct event_trigger_data *data)
967 return event_trigger_print("traceon", m, (void *)data->count,
972 traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
973 struct event_trigger_data *data)
975 return event_trigger_print("traceoff", m, (void *)data->count,
979 static struct event_trigger_ops traceon_trigger_ops = {
980 .func = traceon_trigger,
981 .print = traceon_trigger_print,
982 .init = event_trigger_init,
983 .free = event_trigger_free,
986 static struct event_trigger_ops traceon_count_trigger_ops = {
987 .func = traceon_count_trigger,
988 .print = traceon_trigger_print,
989 .init = event_trigger_init,
990 .free = event_trigger_free,
993 static struct event_trigger_ops traceoff_trigger_ops = {
994 .func = traceoff_trigger,
995 .print = traceoff_trigger_print,
996 .init = event_trigger_init,
997 .free = event_trigger_free,
1000 static struct event_trigger_ops traceoff_count_trigger_ops = {
1001 .func = traceoff_count_trigger,
1002 .print = traceoff_trigger_print,
1003 .init = event_trigger_init,
1004 .free = event_trigger_free,
1007 static struct event_trigger_ops *
1008 onoff_get_trigger_ops(char *cmd, char *param)
1010 struct event_trigger_ops *ops;
1012 /* we register both traceon and traceoff to this callback */
1013 if (strcmp(cmd, "traceon") == 0)
1014 ops = param ? &traceon_count_trigger_ops :
1015 &traceon_trigger_ops;
1017 ops = param ? &traceoff_count_trigger_ops :
1018 &traceoff_trigger_ops;
1023 static struct event_command trigger_traceon_cmd = {
1025 .trigger_type = ETT_TRACE_ONOFF,
1026 .func = event_trigger_callback,
1027 .reg = register_trigger,
1028 .unreg = unregister_trigger,
1029 .get_trigger_ops = onoff_get_trigger_ops,
1030 .set_filter = set_trigger_filter,
1033 static struct event_command trigger_traceoff_cmd = {
1035 .trigger_type = ETT_TRACE_ONOFF,
1036 .flags = EVENT_CMD_FL_POST_TRIGGER,
1037 .func = event_trigger_callback,
1038 .reg = register_trigger,
1039 .unreg = unregister_trigger,
1040 .get_trigger_ops = onoff_get_trigger_ops,
1041 .set_filter = set_trigger_filter,
1044 #ifdef CONFIG_TRACER_SNAPSHOT
1046 snapshot_trigger(struct event_trigger_data *data, void *rec,
1047 struct ring_buffer_event *event)
1049 struct trace_event_file *file = data->private_data;
1052 tracing_snapshot_instance(file->tr);
1058 snapshot_count_trigger(struct event_trigger_data *data, void *rec,
1059 struct ring_buffer_event *event)
1064 if (data->count != -1)
1067 snapshot_trigger(data, rec, event);
1071 register_snapshot_trigger(char *glob, struct event_trigger_ops *ops,
1072 struct event_trigger_data *data,
1073 struct trace_event_file *file)
1075 int ret = register_trigger(glob, ops, data, file);
1077 if (ret > 0 && tracing_alloc_snapshot_instance(file->tr) != 0) {
1078 unregister_trigger(glob, ops, data, file);
1086 snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1087 struct event_trigger_data *data)
1089 return event_trigger_print("snapshot", m, (void *)data->count,
1093 static struct event_trigger_ops snapshot_trigger_ops = {
1094 .func = snapshot_trigger,
1095 .print = snapshot_trigger_print,
1096 .init = event_trigger_init,
1097 .free = event_trigger_free,
1100 static struct event_trigger_ops snapshot_count_trigger_ops = {
1101 .func = snapshot_count_trigger,
1102 .print = snapshot_trigger_print,
1103 .init = event_trigger_init,
1104 .free = event_trigger_free,
1107 static struct event_trigger_ops *
1108 snapshot_get_trigger_ops(char *cmd, char *param)
1110 return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
1113 static struct event_command trigger_snapshot_cmd = {
1115 .trigger_type = ETT_SNAPSHOT,
1116 .func = event_trigger_callback,
1117 .reg = register_snapshot_trigger,
1118 .unreg = unregister_trigger,
1119 .get_trigger_ops = snapshot_get_trigger_ops,
1120 .set_filter = set_trigger_filter,
1123 static __init int register_trigger_snapshot_cmd(void)
1127 ret = register_event_command(&trigger_snapshot_cmd);
1133 static __init int register_trigger_snapshot_cmd(void) { return 0; }
1134 #endif /* CONFIG_TRACER_SNAPSHOT */
1136 #ifdef CONFIG_STACKTRACE
1137 #ifdef CONFIG_UNWINDER_ORC
1139 * event_triggers_post_call()
1140 * trace_event_raw_event_xxx()
1142 # define STACK_SKIP 2
1146 * stacktrace_trigger()
1147 * event_triggers_post_call()
1148 * trace_event_buffer_commit()
1149 * trace_event_raw_event_xxx()
1151 #define STACK_SKIP 4
1155 stacktrace_trigger(struct event_trigger_data *data, void *rec,
1156 struct ring_buffer_event *event)
1158 trace_dump_stack(STACK_SKIP);
1162 stacktrace_count_trigger(struct event_trigger_data *data, void *rec,
1163 struct ring_buffer_event *event)
1168 if (data->count != -1)
1171 stacktrace_trigger(data, rec, event);
1175 stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1176 struct event_trigger_data *data)
1178 return event_trigger_print("stacktrace", m, (void *)data->count,
1182 static struct event_trigger_ops stacktrace_trigger_ops = {
1183 .func = stacktrace_trigger,
1184 .print = stacktrace_trigger_print,
1185 .init = event_trigger_init,
1186 .free = event_trigger_free,
1189 static struct event_trigger_ops stacktrace_count_trigger_ops = {
1190 .func = stacktrace_count_trigger,
1191 .print = stacktrace_trigger_print,
1192 .init = event_trigger_init,
1193 .free = event_trigger_free,
1196 static struct event_trigger_ops *
1197 stacktrace_get_trigger_ops(char *cmd, char *param)
1199 return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
1202 static struct event_command trigger_stacktrace_cmd = {
1203 .name = "stacktrace",
1204 .trigger_type = ETT_STACKTRACE,
1205 .flags = EVENT_CMD_FL_POST_TRIGGER,
1206 .func = event_trigger_callback,
1207 .reg = register_trigger,
1208 .unreg = unregister_trigger,
1209 .get_trigger_ops = stacktrace_get_trigger_ops,
1210 .set_filter = set_trigger_filter,
1213 static __init int register_trigger_stacktrace_cmd(void)
1217 ret = register_event_command(&trigger_stacktrace_cmd);
1223 static __init int register_trigger_stacktrace_cmd(void) { return 0; }
1224 #endif /* CONFIG_STACKTRACE */
1226 static __init void unregister_trigger_traceon_traceoff_cmds(void)
1228 unregister_event_command(&trigger_traceon_cmd);
1229 unregister_event_command(&trigger_traceoff_cmd);
1233 event_enable_trigger(struct event_trigger_data *data, void *rec,
1234 struct ring_buffer_event *event)
1236 struct enable_trigger_data *enable_data = data->private_data;
1238 if (enable_data->enable)
1239 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1241 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1245 event_enable_count_trigger(struct event_trigger_data *data, void *rec,
1246 struct ring_buffer_event *event)
1248 struct enable_trigger_data *enable_data = data->private_data;
1253 /* Skip if the event is in a state we want to switch to */
1254 if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
1257 if (data->count != -1)
1260 event_enable_trigger(data, rec, event);
1263 int event_enable_trigger_print(struct seq_file *m,
1264 struct event_trigger_ops *ops,
1265 struct event_trigger_data *data)
1267 struct enable_trigger_data *enable_data = data->private_data;
1269 seq_printf(m, "%s:%s:%s",
1271 (enable_data->enable ? ENABLE_HIST_STR : DISABLE_HIST_STR) :
1272 (enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR),
1273 enable_data->file->event_call->class->system,
1274 trace_event_name(enable_data->file->event_call));
1276 if (data->count == -1)
1277 seq_puts(m, ":unlimited");
1279 seq_printf(m, ":count=%ld", data->count);
1281 if (data->filter_str)
1282 seq_printf(m, " if %s\n", data->filter_str);
1289 void event_enable_trigger_free(struct event_trigger_ops *ops,
1290 struct event_trigger_data *data)
1292 struct enable_trigger_data *enable_data = data->private_data;
1294 if (WARN_ON_ONCE(data->ref <= 0))
1299 /* Remove the SOFT_MODE flag */
1300 trace_event_enable_disable(enable_data->file, 0, 1);
1301 module_put(enable_data->file->event_call->mod);
1302 trigger_data_free(data);
1307 static struct event_trigger_ops event_enable_trigger_ops = {
1308 .func = event_enable_trigger,
1309 .print = event_enable_trigger_print,
1310 .init = event_trigger_init,
1311 .free = event_enable_trigger_free,
1314 static struct event_trigger_ops event_enable_count_trigger_ops = {
1315 .func = event_enable_count_trigger,
1316 .print = event_enable_trigger_print,
1317 .init = event_trigger_init,
1318 .free = event_enable_trigger_free,
1321 static struct event_trigger_ops event_disable_trigger_ops = {
1322 .func = event_enable_trigger,
1323 .print = event_enable_trigger_print,
1324 .init = event_trigger_init,
1325 .free = event_enable_trigger_free,
1328 static struct event_trigger_ops event_disable_count_trigger_ops = {
1329 .func = event_enable_count_trigger,
1330 .print = event_enable_trigger_print,
1331 .init = event_trigger_init,
1332 .free = event_enable_trigger_free,
1335 int event_enable_trigger_func(struct event_command *cmd_ops,
1336 struct trace_event_file *file,
1337 char *glob, char *cmd, char *param)
1339 struct trace_event_file *event_enable_file;
1340 struct enable_trigger_data *enable_data;
1341 struct event_trigger_data *trigger_data;
1342 struct event_trigger_ops *trigger_ops;
1343 struct trace_array *tr = file->tr;
1355 /* separate the trigger from the filter (s:e:n [if filter]) */
1356 trigger = strsep(¶m, " \t");
1360 system = strsep(&trigger, ":");
1364 event = strsep(&trigger, ":");
1367 event_enable_file = find_event_file(tr, system, event);
1368 if (!event_enable_file)
1371 #ifdef CONFIG_HIST_TRIGGERS
1372 hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) ||
1373 (strcmp(cmd, DISABLE_HIST_STR) == 0));
1375 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1376 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1378 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1380 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
1383 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
1387 enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
1389 kfree(trigger_data);
1393 trigger_data->count = -1;
1394 trigger_data->ops = trigger_ops;
1395 trigger_data->cmd_ops = cmd_ops;
1396 INIT_LIST_HEAD(&trigger_data->list);
1397 RCU_INIT_POINTER(trigger_data->filter, NULL);
1399 enable_data->hist = hist;
1400 enable_data->enable = enable;
1401 enable_data->file = event_enable_file;
1402 trigger_data->private_data = enable_data;
1404 if (glob[0] == '!') {
1405 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
1406 kfree(trigger_data);
1412 /* Up the trigger_data count to make sure nothing frees it on failure */
1413 event_trigger_init(trigger_ops, trigger_data);
1416 number = strsep(&trigger, ":");
1419 if (!strlen(number))
1423 * We use the callback data field (which is a pointer)
1426 ret = kstrtoul(number, 0, &trigger_data->count);
1431 if (!param) /* if param is non-empty, it's supposed to be a filter */
1434 if (!cmd_ops->set_filter)
1437 ret = cmd_ops->set_filter(param, trigger_data, file);
1442 /* Don't let event modules unload while probe registered */
1443 ret = try_module_get(event_enable_file->event_call->mod);
1449 ret = trace_event_enable_disable(event_enable_file, 1, 1);
1452 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1454 * The above returns on success the # of functions enabled,
1455 * but if it didn't find any functions it returns zero.
1456 * Consider no functions a failure too.
1463 /* Just return zero, not the number of enabled functions */
1465 event_trigger_free(trigger_ops, trigger_data);
1470 trace_event_enable_disable(event_enable_file, 0, 1);
1472 module_put(event_enable_file->event_call->mod);
1474 if (cmd_ops->set_filter)
1475 cmd_ops->set_filter(NULL, trigger_data, NULL);
1476 event_trigger_free(trigger_ops, trigger_data);
1481 int event_enable_register_trigger(char *glob,
1482 struct event_trigger_ops *ops,
1483 struct event_trigger_data *data,
1484 struct trace_event_file *file)
1486 struct enable_trigger_data *enable_data = data->private_data;
1487 struct enable_trigger_data *test_enable_data;
1488 struct event_trigger_data *test;
1491 list_for_each_entry_rcu(test, &file->triggers, list) {
1492 test_enable_data = test->private_data;
1493 if (test_enable_data &&
1494 (test->cmd_ops->trigger_type ==
1495 data->cmd_ops->trigger_type) &&
1496 (test_enable_data->file == enable_data->file)) {
1502 if (data->ops->init) {
1503 ret = data->ops->init(data->ops, data);
1508 list_add_rcu(&data->list, &file->triggers);
1511 update_cond_flag(file);
1512 if (trace_event_trigger_enable_disable(file, 1) < 0) {
1513 list_del_rcu(&data->list);
1514 update_cond_flag(file);
1521 void event_enable_unregister_trigger(char *glob,
1522 struct event_trigger_ops *ops,
1523 struct event_trigger_data *test,
1524 struct trace_event_file *file)
1526 struct enable_trigger_data *test_enable_data = test->private_data;
1527 struct enable_trigger_data *enable_data;
1528 struct event_trigger_data *data;
1529 bool unregistered = false;
1531 list_for_each_entry_rcu(data, &file->triggers, list) {
1532 enable_data = data->private_data;
1534 (data->cmd_ops->trigger_type ==
1535 test->cmd_ops->trigger_type) &&
1536 (enable_data->file == test_enable_data->file)) {
1537 unregistered = true;
1538 list_del_rcu(&data->list);
1539 trace_event_trigger_enable_disable(file, 0);
1540 update_cond_flag(file);
1545 if (unregistered && data->ops->free)
1546 data->ops->free(data->ops, data);
1549 static struct event_trigger_ops *
1550 event_enable_get_trigger_ops(char *cmd, char *param)
1552 struct event_trigger_ops *ops;
1555 #ifdef CONFIG_HIST_TRIGGERS
1556 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1557 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1559 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1562 ops = param ? &event_enable_count_trigger_ops :
1563 &event_enable_trigger_ops;
1565 ops = param ? &event_disable_count_trigger_ops :
1566 &event_disable_trigger_ops;
1571 static struct event_command trigger_enable_cmd = {
1572 .name = ENABLE_EVENT_STR,
1573 .trigger_type = ETT_EVENT_ENABLE,
1574 .func = event_enable_trigger_func,
1575 .reg = event_enable_register_trigger,
1576 .unreg = event_enable_unregister_trigger,
1577 .get_trigger_ops = event_enable_get_trigger_ops,
1578 .set_filter = set_trigger_filter,
1581 static struct event_command trigger_disable_cmd = {
1582 .name = DISABLE_EVENT_STR,
1583 .trigger_type = ETT_EVENT_ENABLE,
1584 .func = event_enable_trigger_func,
1585 .reg = event_enable_register_trigger,
1586 .unreg = event_enable_unregister_trigger,
1587 .get_trigger_ops = event_enable_get_trigger_ops,
1588 .set_filter = set_trigger_filter,
1591 static __init void unregister_trigger_enable_disable_cmds(void)
1593 unregister_event_command(&trigger_enable_cmd);
1594 unregister_event_command(&trigger_disable_cmd);
1597 static __init int register_trigger_enable_disable_cmds(void)
1601 ret = register_event_command(&trigger_enable_cmd);
1602 if (WARN_ON(ret < 0))
1604 ret = register_event_command(&trigger_disable_cmd);
1605 if (WARN_ON(ret < 0))
1606 unregister_trigger_enable_disable_cmds();
1611 static __init int register_trigger_traceon_traceoff_cmds(void)
1615 ret = register_event_command(&trigger_traceon_cmd);
1616 if (WARN_ON(ret < 0))
1618 ret = register_event_command(&trigger_traceoff_cmd);
1619 if (WARN_ON(ret < 0))
1620 unregister_trigger_traceon_traceoff_cmds();
1625 __init int register_trigger_cmds(void)
1627 register_trigger_traceon_traceoff_cmds();
1628 register_trigger_snapshot_cmd();
1629 register_trigger_stacktrace_cmd();
1630 register_trigger_enable_disable_cmds();
1631 register_trigger_hist_enable_disable_cmds();
1632 register_trigger_hist_cmd();