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)
122 return seq_list_next(t, &event_file->triggers, pos);
125 static void *trigger_start(struct seq_file *m, loff_t *pos)
127 struct trace_event_file *event_file;
129 /* ->stop() is called even if ->start() fails */
130 mutex_lock(&event_mutex);
131 event_file = event_file_data(m->private);
132 if (unlikely(!event_file))
133 return ERR_PTR(-ENODEV);
135 if (list_empty(&event_file->triggers))
136 return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL;
138 return seq_list_start(&event_file->triggers, *pos);
141 static void trigger_stop(struct seq_file *m, void *t)
143 mutex_unlock(&event_mutex);
146 static int trigger_show(struct seq_file *m, void *v)
148 struct event_trigger_data *data;
149 struct event_command *p;
151 if (v == SHOW_AVAILABLE_TRIGGERS) {
152 seq_puts(m, "# Available triggers:\n");
154 mutex_lock(&trigger_cmd_mutex);
155 list_for_each_entry_reverse(p, &trigger_commands, list)
156 seq_printf(m, " %s", p->name);
158 mutex_unlock(&trigger_cmd_mutex);
162 data = list_entry(v, struct event_trigger_data, list);
163 data->ops->print(m, data->ops, data);
168 static const struct seq_operations event_triggers_seq_ops = {
169 .start = trigger_start,
170 .next = trigger_next,
171 .stop = trigger_stop,
172 .show = trigger_show,
175 static int event_trigger_regex_open(struct inode *inode, struct file *file)
179 ret = security_locked_down(LOCKDOWN_TRACEFS);
183 mutex_lock(&event_mutex);
185 if (unlikely(!event_file_data(file))) {
186 mutex_unlock(&event_mutex);
190 if ((file->f_mode & FMODE_WRITE) &&
191 (file->f_flags & O_TRUNC)) {
192 struct trace_event_file *event_file;
193 struct event_command *p;
195 event_file = event_file_data(file);
197 list_for_each_entry(p, &trigger_commands, list) {
199 p->unreg_all(event_file);
203 if (file->f_mode & FMODE_READ) {
204 ret = seq_open(file, &event_triggers_seq_ops);
206 struct seq_file *m = file->private_data;
211 mutex_unlock(&event_mutex);
216 static int trigger_process_regex(struct trace_event_file *file, char *buff)
218 char *command, *next = buff;
219 struct event_command *p;
222 command = strsep(&next, ": \t");
223 command = (command[0] != '!') ? command : command + 1;
225 mutex_lock(&trigger_cmd_mutex);
226 list_for_each_entry(p, &trigger_commands, list) {
227 if (strcmp(p->name, command) == 0) {
228 ret = p->func(p, file, buff, command, next);
233 mutex_unlock(&trigger_cmd_mutex);
238 static ssize_t event_trigger_regex_write(struct file *file,
239 const char __user *ubuf,
240 size_t cnt, loff_t *ppos)
242 struct trace_event_file *event_file;
249 if (cnt >= PAGE_SIZE)
252 buf = memdup_user_nul(ubuf, cnt);
258 mutex_lock(&event_mutex);
259 event_file = event_file_data(file);
260 if (unlikely(!event_file)) {
261 mutex_unlock(&event_mutex);
265 ret = trigger_process_regex(event_file, buf);
266 mutex_unlock(&event_mutex);
278 static int event_trigger_regex_release(struct inode *inode, struct file *file)
280 mutex_lock(&event_mutex);
282 if (file->f_mode & FMODE_READ)
283 seq_release(inode, file);
285 mutex_unlock(&event_mutex);
291 event_trigger_write(struct file *filp, const char __user *ubuf,
292 size_t cnt, loff_t *ppos)
294 return event_trigger_regex_write(filp, ubuf, cnt, ppos);
298 event_trigger_open(struct inode *inode, struct file *filp)
300 /* Checks for tracefs lockdown */
301 return event_trigger_regex_open(inode, filp);
305 event_trigger_release(struct inode *inode, struct file *file)
307 return event_trigger_regex_release(inode, file);
310 const struct file_operations event_trigger_fops = {
311 .open = event_trigger_open,
313 .write = event_trigger_write,
314 .llseek = tracing_lseek,
315 .release = event_trigger_release,
319 * Currently we only register event commands from __init, so mark this
322 __init int register_event_command(struct event_command *cmd)
324 struct event_command *p;
327 mutex_lock(&trigger_cmd_mutex);
328 list_for_each_entry(p, &trigger_commands, list) {
329 if (strcmp(cmd->name, p->name) == 0) {
334 list_add(&cmd->list, &trigger_commands);
336 mutex_unlock(&trigger_cmd_mutex);
342 * Currently we only unregister event commands from __init, so mark
345 __init int unregister_event_command(struct event_command *cmd)
347 struct event_command *p, *n;
350 mutex_lock(&trigger_cmd_mutex);
351 list_for_each_entry_safe(p, n, &trigger_commands, list) {
352 if (strcmp(cmd->name, p->name) == 0) {
354 list_del_init(&p->list);
359 mutex_unlock(&trigger_cmd_mutex);
365 * event_trigger_print - Generic event_trigger_ops @print implementation
366 * @name: The name of the event trigger
367 * @m: The seq_file being printed to
368 * @data: Trigger-specific data
369 * @filter_str: filter_str to print, if present
371 * Common implementation for event triggers to print themselves.
373 * Usually wrapped by a function that simply sets the @name of the
374 * trigger command and then invokes this.
376 * Return: 0 on success, errno otherwise
379 event_trigger_print(const char *name, struct seq_file *m,
380 void *data, char *filter_str)
382 long count = (long)data;
387 seq_puts(m, ":unlimited");
389 seq_printf(m, ":count=%ld", count);
392 seq_printf(m, " if %s\n", filter_str);
400 * event_trigger_init - Generic event_trigger_ops @init implementation
401 * @ops: The trigger ops associated with the trigger
402 * @data: Trigger-specific data
404 * Common implementation of event trigger initialization.
406 * Usually used directly as the @init method in event trigger
409 * Return: 0 on success, errno otherwise
411 int event_trigger_init(struct event_trigger_ops *ops,
412 struct event_trigger_data *data)
419 * event_trigger_free - Generic event_trigger_ops @free implementation
420 * @ops: The trigger ops associated with the trigger
421 * @data: Trigger-specific data
423 * Common implementation of event trigger de-initialization.
425 * Usually used directly as the @free method in event trigger
429 event_trigger_free(struct event_trigger_ops *ops,
430 struct event_trigger_data *data)
432 if (WARN_ON_ONCE(data->ref <= 0))
437 trigger_data_free(data);
440 int trace_event_trigger_enable_disable(struct trace_event_file *file,
445 if (trigger_enable) {
446 if (atomic_inc_return(&file->tm_ref) > 1)
448 set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
449 ret = trace_event_enable_disable(file, 1, 1);
451 if (atomic_dec_return(&file->tm_ref) > 0)
453 clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
454 ret = trace_event_enable_disable(file, 0, 1);
461 * clear_event_triggers - Clear all triggers associated with a trace array
462 * @tr: The trace array to clear
464 * For each trigger, the triggering event has its tm_ref decremented
465 * via trace_event_trigger_enable_disable(), and any associated event
466 * (in the case of enable/disable_event triggers) will have its sm_ref
467 * decremented via free()->trace_event_enable_disable(). That
468 * combination effectively reverses the soft-mode/trigger state added
469 * by trigger registration.
471 * Must be called with event_mutex held.
474 clear_event_triggers(struct trace_array *tr)
476 struct trace_event_file *file;
478 list_for_each_entry(file, &tr->events, list) {
479 struct event_trigger_data *data, *n;
480 list_for_each_entry_safe(data, n, &file->triggers, list) {
481 trace_event_trigger_enable_disable(file, 0);
482 list_del_rcu(&data->list);
484 data->ops->free(data->ops, data);
490 * update_cond_flag - Set or reset the TRIGGER_COND bit
491 * @file: The trace_event_file associated with the event
493 * If an event has triggers and any of those triggers has a filter or
494 * a post_trigger, trigger invocation needs to be deferred until after
495 * the current event has logged its data, and the event should have
496 * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be
499 void update_cond_flag(struct trace_event_file *file)
501 struct event_trigger_data *data;
502 bool set_cond = false;
504 list_for_each_entry_rcu(data, &file->triggers, list) {
505 if (data->filter || event_command_post_trigger(data->cmd_ops) ||
506 event_command_needs_rec(data->cmd_ops)) {
513 set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
515 clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
519 * register_trigger - Generic event_command @reg implementation
520 * @glob: The raw string used to register the trigger
521 * @ops: The trigger ops associated with the trigger
522 * @data: Trigger-specific data to associate with the trigger
523 * @file: The trace_event_file associated with the event
525 * Common implementation for event trigger registration.
527 * Usually used directly as the @reg method in event command
530 * Return: 0 on success, errno otherwise
532 static int register_trigger(char *glob, struct event_trigger_ops *ops,
533 struct event_trigger_data *data,
534 struct trace_event_file *file)
536 struct event_trigger_data *test;
539 list_for_each_entry_rcu(test, &file->triggers, list) {
540 if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) {
546 if (data->ops->init) {
547 ret = data->ops->init(data->ops, data);
552 list_add_rcu(&data->list, &file->triggers);
555 update_cond_flag(file);
556 if (trace_event_trigger_enable_disable(file, 1) < 0) {
557 list_del_rcu(&data->list);
558 update_cond_flag(file);
566 * unregister_trigger - Generic event_command @unreg implementation
567 * @glob: The raw string used to register the trigger
568 * @ops: The trigger ops associated with the trigger
569 * @test: Trigger-specific data used to find the trigger to remove
570 * @file: The trace_event_file associated with the event
572 * Common implementation for event trigger unregistration.
574 * Usually used directly as the @unreg method in event command
577 static void unregister_trigger(char *glob, struct event_trigger_ops *ops,
578 struct event_trigger_data *test,
579 struct trace_event_file *file)
581 struct event_trigger_data *data;
582 bool unregistered = false;
584 list_for_each_entry_rcu(data, &file->triggers, list) {
585 if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
587 list_del_rcu(&data->list);
588 trace_event_trigger_enable_disable(file, 0);
589 update_cond_flag(file);
594 if (unregistered && data->ops->free)
595 data->ops->free(data->ops, data);
599 * event_trigger_callback - Generic event_command @func implementation
600 * @cmd_ops: The command ops, used for trigger registration
601 * @file: The trace_event_file associated with the event
602 * @glob: The raw string used to register the trigger
603 * @cmd: The cmd portion of the string used to register the trigger
604 * @param: The params portion of the string used to register the trigger
606 * Common implementation for event command parsing and trigger
609 * Usually used directly as the @func method in event command
612 * Return: 0 on success, errno otherwise
615 event_trigger_callback(struct event_command *cmd_ops,
616 struct trace_event_file *file,
617 char *glob, char *cmd, char *param)
619 struct event_trigger_data *trigger_data;
620 struct event_trigger_ops *trigger_ops;
621 char *trigger = NULL;
625 /* separate the trigger from the filter (t:n [if filter]) */
626 if (param && isdigit(param[0]))
627 trigger = strsep(¶m, " \t");
629 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
632 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
636 trigger_data->count = -1;
637 trigger_data->ops = trigger_ops;
638 trigger_data->cmd_ops = cmd_ops;
639 trigger_data->private_data = file;
640 INIT_LIST_HEAD(&trigger_data->list);
641 INIT_LIST_HEAD(&trigger_data->named_list);
643 if (glob[0] == '!') {
644 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
651 number = strsep(&trigger, ":");
658 * We use the callback data field (which is a pointer)
661 ret = kstrtoul(number, 0, &trigger_data->count);
666 if (!param) /* if param is non-empty, it's supposed to be a filter */
669 if (!cmd_ops->set_filter)
672 ret = cmd_ops->set_filter(param, trigger_data, file);
677 /* Up the trigger_data count to make sure reg doesn't free it on failure */
678 event_trigger_init(trigger_ops, trigger_data);
679 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
681 * The above returns on success the # of functions enabled,
682 * but if it didn't find any functions it returns zero.
683 * Consider no functions a failure too.
686 cmd_ops->unreg(glob, trigger_ops, trigger_data, file);
691 /* Down the counter of trigger_data or free it if not used anymore */
692 event_trigger_free(trigger_ops, trigger_data);
697 if (cmd_ops->set_filter)
698 cmd_ops->set_filter(NULL, trigger_data, NULL);
704 * set_trigger_filter - Generic event_command @set_filter implementation
705 * @filter_str: The filter string for the trigger, NULL to remove filter
706 * @trigger_data: Trigger-specific data
707 * @file: The trace_event_file associated with the event
709 * Common implementation for event command filter parsing and filter
712 * Usually used directly as the @set_filter method in event command
715 * Also used to remove a filter (if filter_str = NULL).
717 * Return: 0 on success, errno otherwise
719 int set_trigger_filter(char *filter_str,
720 struct event_trigger_data *trigger_data,
721 struct trace_event_file *file)
723 struct event_trigger_data *data = trigger_data;
724 struct event_filter *filter = NULL, *tmp;
728 if (!filter_str) /* clear the current filter */
731 s = strsep(&filter_str, " \t");
733 if (!strlen(s) || strcmp(s, "if") != 0)
739 /* The filter is for the 'trigger' event, not the triggered event */
740 ret = create_event_filter(file->tr, file->event_call,
741 filter_str, false, &filter);
743 * If create_event_filter() fails, filter still needs to be freed.
744 * Which the calling code will do with data->filter.
747 tmp = rcu_access_pointer(data->filter);
749 rcu_assign_pointer(data->filter, filter);
752 /* Make sure the call is done with the filter */
753 tracepoint_synchronize_unregister();
754 free_event_filter(tmp);
757 kfree(data->filter_str);
758 data->filter_str = NULL;
761 data->filter_str = kstrdup(filter_str, GFP_KERNEL);
762 if (!data->filter_str) {
763 free_event_filter(rcu_access_pointer(data->filter));
772 static LIST_HEAD(named_triggers);
775 * find_named_trigger - Find the common named trigger associated with @name
776 * @name: The name of the set of named triggers to find the common data for
778 * Named triggers are sets of triggers that share a common set of
779 * trigger data. The first named trigger registered with a given name
780 * owns the common trigger data that the others subsequently
781 * registered with the same name will reference. This function
782 * returns the common trigger data associated with that first
783 * registered instance.
785 * Return: the common trigger data for the given named trigger on
786 * success, NULL otherwise.
788 struct event_trigger_data *find_named_trigger(const char *name)
790 struct event_trigger_data *data;
795 list_for_each_entry(data, &named_triggers, named_list) {
796 if (data->named_data)
798 if (strcmp(data->name, name) == 0)
806 * is_named_trigger - determine if a given trigger is a named trigger
807 * @test: The trigger data to test
809 * Return: true if 'test' is a named trigger, false otherwise.
811 bool is_named_trigger(struct event_trigger_data *test)
813 struct event_trigger_data *data;
815 list_for_each_entry(data, &named_triggers, named_list) {
824 * save_named_trigger - save the trigger in the named trigger list
825 * @name: The name of the named trigger set
826 * @data: The trigger data to save
828 * Return: 0 if successful, negative error otherwise.
830 int save_named_trigger(const char *name, struct event_trigger_data *data)
832 data->name = kstrdup(name, GFP_KERNEL);
836 list_add(&data->named_list, &named_triggers);
842 * del_named_trigger - delete a trigger from the named trigger list
843 * @data: The trigger data to delete
845 void del_named_trigger(struct event_trigger_data *data)
850 list_del(&data->named_list);
853 static void __pause_named_trigger(struct event_trigger_data *data, bool pause)
855 struct event_trigger_data *test;
857 list_for_each_entry(test, &named_triggers, named_list) {
858 if (strcmp(test->name, data->name) == 0) {
860 test->paused_tmp = test->paused;
863 test->paused = test->paused_tmp;
870 * pause_named_trigger - Pause all named triggers with the same name
871 * @data: The trigger data of a named trigger to pause
873 * Pauses a named trigger along with all other triggers having the
874 * same name. Because named triggers share a common set of data,
875 * pausing only one is meaningless, so pausing one named trigger needs
876 * to pause all triggers with the same name.
878 void pause_named_trigger(struct event_trigger_data *data)
880 __pause_named_trigger(data, true);
884 * unpause_named_trigger - Un-pause all named triggers with the same name
885 * @data: The trigger data of a named trigger to unpause
887 * Un-pauses a named trigger along with all other triggers having the
888 * same name. Because named triggers share a common set of data,
889 * unpausing only one is meaningless, so unpausing one named trigger
890 * needs to unpause all triggers with the same name.
892 void unpause_named_trigger(struct event_trigger_data *data)
894 __pause_named_trigger(data, false);
898 * set_named_trigger_data - Associate common named trigger data
899 * @data: The trigger data of a named trigger to unpause
901 * Named triggers are sets of triggers that share a common set of
902 * trigger data. The first named trigger registered with a given name
903 * owns the common trigger data that the others subsequently
904 * registered with the same name will reference. This function
905 * associates the common trigger data from the first trigger with the
908 void set_named_trigger_data(struct event_trigger_data *data,
909 struct event_trigger_data *named_data)
911 data->named_data = named_data;
914 struct event_trigger_data *
915 get_named_trigger_data(struct event_trigger_data *data)
917 return data->named_data;
921 traceon_trigger(struct event_trigger_data *data, void *rec,
922 struct ring_buffer_event *event)
931 traceon_count_trigger(struct event_trigger_data *data, void *rec,
932 struct ring_buffer_event *event)
940 if (data->count != -1)
947 traceoff_trigger(struct event_trigger_data *data, void *rec,
948 struct ring_buffer_event *event)
950 if (!tracing_is_on())
957 traceoff_count_trigger(struct event_trigger_data *data, void *rec,
958 struct ring_buffer_event *event)
960 if (!tracing_is_on())
966 if (data->count != -1)
973 traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
974 struct event_trigger_data *data)
976 return event_trigger_print("traceon", m, (void *)data->count,
981 traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
982 struct event_trigger_data *data)
984 return event_trigger_print("traceoff", m, (void *)data->count,
988 static struct event_trigger_ops traceon_trigger_ops = {
989 .func = traceon_trigger,
990 .print = traceon_trigger_print,
991 .init = event_trigger_init,
992 .free = event_trigger_free,
995 static struct event_trigger_ops traceon_count_trigger_ops = {
996 .func = traceon_count_trigger,
997 .print = traceon_trigger_print,
998 .init = event_trigger_init,
999 .free = event_trigger_free,
1002 static struct event_trigger_ops traceoff_trigger_ops = {
1003 .func = traceoff_trigger,
1004 .print = traceoff_trigger_print,
1005 .init = event_trigger_init,
1006 .free = event_trigger_free,
1009 static struct event_trigger_ops traceoff_count_trigger_ops = {
1010 .func = traceoff_count_trigger,
1011 .print = traceoff_trigger_print,
1012 .init = event_trigger_init,
1013 .free = event_trigger_free,
1016 static struct event_trigger_ops *
1017 onoff_get_trigger_ops(char *cmd, char *param)
1019 struct event_trigger_ops *ops;
1021 /* we register both traceon and traceoff to this callback */
1022 if (strcmp(cmd, "traceon") == 0)
1023 ops = param ? &traceon_count_trigger_ops :
1024 &traceon_trigger_ops;
1026 ops = param ? &traceoff_count_trigger_ops :
1027 &traceoff_trigger_ops;
1032 static struct event_command trigger_traceon_cmd = {
1034 .trigger_type = ETT_TRACE_ONOFF,
1035 .func = event_trigger_callback,
1036 .reg = register_trigger,
1037 .unreg = unregister_trigger,
1038 .get_trigger_ops = onoff_get_trigger_ops,
1039 .set_filter = set_trigger_filter,
1042 static struct event_command trigger_traceoff_cmd = {
1044 .trigger_type = ETT_TRACE_ONOFF,
1045 .flags = EVENT_CMD_FL_POST_TRIGGER,
1046 .func = event_trigger_callback,
1047 .reg = register_trigger,
1048 .unreg = unregister_trigger,
1049 .get_trigger_ops = onoff_get_trigger_ops,
1050 .set_filter = set_trigger_filter,
1053 #ifdef CONFIG_TRACER_SNAPSHOT
1055 snapshot_trigger(struct event_trigger_data *data, void *rec,
1056 struct ring_buffer_event *event)
1058 struct trace_event_file *file = data->private_data;
1061 tracing_snapshot_instance(file->tr);
1067 snapshot_count_trigger(struct event_trigger_data *data, void *rec,
1068 struct ring_buffer_event *event)
1073 if (data->count != -1)
1076 snapshot_trigger(data, rec, event);
1080 register_snapshot_trigger(char *glob, struct event_trigger_ops *ops,
1081 struct event_trigger_data *data,
1082 struct trace_event_file *file)
1084 int ret = register_trigger(glob, ops, data, file);
1086 if (ret > 0 && tracing_alloc_snapshot_instance(file->tr) != 0) {
1087 unregister_trigger(glob, ops, data, file);
1095 snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1096 struct event_trigger_data *data)
1098 return event_trigger_print("snapshot", m, (void *)data->count,
1102 static struct event_trigger_ops snapshot_trigger_ops = {
1103 .func = snapshot_trigger,
1104 .print = snapshot_trigger_print,
1105 .init = event_trigger_init,
1106 .free = event_trigger_free,
1109 static struct event_trigger_ops snapshot_count_trigger_ops = {
1110 .func = snapshot_count_trigger,
1111 .print = snapshot_trigger_print,
1112 .init = event_trigger_init,
1113 .free = event_trigger_free,
1116 static struct event_trigger_ops *
1117 snapshot_get_trigger_ops(char *cmd, char *param)
1119 return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
1122 static struct event_command trigger_snapshot_cmd = {
1124 .trigger_type = ETT_SNAPSHOT,
1125 .func = event_trigger_callback,
1126 .reg = register_snapshot_trigger,
1127 .unreg = unregister_trigger,
1128 .get_trigger_ops = snapshot_get_trigger_ops,
1129 .set_filter = set_trigger_filter,
1132 static __init int register_trigger_snapshot_cmd(void)
1136 ret = register_event_command(&trigger_snapshot_cmd);
1142 static __init int register_trigger_snapshot_cmd(void) { return 0; }
1143 #endif /* CONFIG_TRACER_SNAPSHOT */
1145 #ifdef CONFIG_STACKTRACE
1146 #ifdef CONFIG_UNWINDER_ORC
1148 * event_triggers_post_call()
1149 * trace_event_raw_event_xxx()
1151 # define STACK_SKIP 2
1155 * stacktrace_trigger()
1156 * event_triggers_post_call()
1157 * trace_event_buffer_commit()
1158 * trace_event_raw_event_xxx()
1160 #define STACK_SKIP 4
1164 stacktrace_trigger(struct event_trigger_data *data, void *rec,
1165 struct ring_buffer_event *event)
1167 trace_dump_stack(STACK_SKIP);
1171 stacktrace_count_trigger(struct event_trigger_data *data, void *rec,
1172 struct ring_buffer_event *event)
1177 if (data->count != -1)
1180 stacktrace_trigger(data, rec, event);
1184 stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1185 struct event_trigger_data *data)
1187 return event_trigger_print("stacktrace", m, (void *)data->count,
1191 static struct event_trigger_ops stacktrace_trigger_ops = {
1192 .func = stacktrace_trigger,
1193 .print = stacktrace_trigger_print,
1194 .init = event_trigger_init,
1195 .free = event_trigger_free,
1198 static struct event_trigger_ops stacktrace_count_trigger_ops = {
1199 .func = stacktrace_count_trigger,
1200 .print = stacktrace_trigger_print,
1201 .init = event_trigger_init,
1202 .free = event_trigger_free,
1205 static struct event_trigger_ops *
1206 stacktrace_get_trigger_ops(char *cmd, char *param)
1208 return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
1211 static struct event_command trigger_stacktrace_cmd = {
1212 .name = "stacktrace",
1213 .trigger_type = ETT_STACKTRACE,
1214 .flags = EVENT_CMD_FL_POST_TRIGGER,
1215 .func = event_trigger_callback,
1216 .reg = register_trigger,
1217 .unreg = unregister_trigger,
1218 .get_trigger_ops = stacktrace_get_trigger_ops,
1219 .set_filter = set_trigger_filter,
1222 static __init int register_trigger_stacktrace_cmd(void)
1226 ret = register_event_command(&trigger_stacktrace_cmd);
1232 static __init int register_trigger_stacktrace_cmd(void) { return 0; }
1233 #endif /* CONFIG_STACKTRACE */
1235 static __init void unregister_trigger_traceon_traceoff_cmds(void)
1237 unregister_event_command(&trigger_traceon_cmd);
1238 unregister_event_command(&trigger_traceoff_cmd);
1242 event_enable_trigger(struct event_trigger_data *data, void *rec,
1243 struct ring_buffer_event *event)
1245 struct enable_trigger_data *enable_data = data->private_data;
1247 if (enable_data->enable)
1248 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1250 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1254 event_enable_count_trigger(struct event_trigger_data *data, void *rec,
1255 struct ring_buffer_event *event)
1257 struct enable_trigger_data *enable_data = data->private_data;
1262 /* Skip if the event is in a state we want to switch to */
1263 if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
1266 if (data->count != -1)
1269 event_enable_trigger(data, rec, event);
1272 int event_enable_trigger_print(struct seq_file *m,
1273 struct event_trigger_ops *ops,
1274 struct event_trigger_data *data)
1276 struct enable_trigger_data *enable_data = data->private_data;
1278 seq_printf(m, "%s:%s:%s",
1280 (enable_data->enable ? ENABLE_HIST_STR : DISABLE_HIST_STR) :
1281 (enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR),
1282 enable_data->file->event_call->class->system,
1283 trace_event_name(enable_data->file->event_call));
1285 if (data->count == -1)
1286 seq_puts(m, ":unlimited");
1288 seq_printf(m, ":count=%ld", data->count);
1290 if (data->filter_str)
1291 seq_printf(m, " if %s\n", data->filter_str);
1298 void event_enable_trigger_free(struct event_trigger_ops *ops,
1299 struct event_trigger_data *data)
1301 struct enable_trigger_data *enable_data = data->private_data;
1303 if (WARN_ON_ONCE(data->ref <= 0))
1308 /* Remove the SOFT_MODE flag */
1309 trace_event_enable_disable(enable_data->file, 0, 1);
1310 module_put(enable_data->file->event_call->mod);
1311 trigger_data_free(data);
1316 static struct event_trigger_ops event_enable_trigger_ops = {
1317 .func = event_enable_trigger,
1318 .print = event_enable_trigger_print,
1319 .init = event_trigger_init,
1320 .free = event_enable_trigger_free,
1323 static struct event_trigger_ops event_enable_count_trigger_ops = {
1324 .func = event_enable_count_trigger,
1325 .print = event_enable_trigger_print,
1326 .init = event_trigger_init,
1327 .free = event_enable_trigger_free,
1330 static struct event_trigger_ops event_disable_trigger_ops = {
1331 .func = event_enable_trigger,
1332 .print = event_enable_trigger_print,
1333 .init = event_trigger_init,
1334 .free = event_enable_trigger_free,
1337 static struct event_trigger_ops event_disable_count_trigger_ops = {
1338 .func = event_enable_count_trigger,
1339 .print = event_enable_trigger_print,
1340 .init = event_trigger_init,
1341 .free = event_enable_trigger_free,
1344 int event_enable_trigger_func(struct event_command *cmd_ops,
1345 struct trace_event_file *file,
1346 char *glob, char *cmd, char *param)
1348 struct trace_event_file *event_enable_file;
1349 struct enable_trigger_data *enable_data;
1350 struct event_trigger_data *trigger_data;
1351 struct event_trigger_ops *trigger_ops;
1352 struct trace_array *tr = file->tr;
1364 /* separate the trigger from the filter (s:e:n [if filter]) */
1365 trigger = strsep(¶m, " \t");
1369 system = strsep(&trigger, ":");
1373 event = strsep(&trigger, ":");
1376 event_enable_file = find_event_file(tr, system, event);
1377 if (!event_enable_file)
1380 #ifdef CONFIG_HIST_TRIGGERS
1381 hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) ||
1382 (strcmp(cmd, DISABLE_HIST_STR) == 0));
1384 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1385 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1387 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1389 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
1392 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
1396 enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
1398 kfree(trigger_data);
1402 trigger_data->count = -1;
1403 trigger_data->ops = trigger_ops;
1404 trigger_data->cmd_ops = cmd_ops;
1405 INIT_LIST_HEAD(&trigger_data->list);
1406 RCU_INIT_POINTER(trigger_data->filter, NULL);
1408 enable_data->hist = hist;
1409 enable_data->enable = enable;
1410 enable_data->file = event_enable_file;
1411 trigger_data->private_data = enable_data;
1413 if (glob[0] == '!') {
1414 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
1415 kfree(trigger_data);
1421 /* Up the trigger_data count to make sure nothing frees it on failure */
1422 event_trigger_init(trigger_ops, trigger_data);
1425 number = strsep(&trigger, ":");
1428 if (!strlen(number))
1432 * We use the callback data field (which is a pointer)
1435 ret = kstrtoul(number, 0, &trigger_data->count);
1440 if (!param) /* if param is non-empty, it's supposed to be a filter */
1443 if (!cmd_ops->set_filter)
1446 ret = cmd_ops->set_filter(param, trigger_data, file);
1451 /* Don't let event modules unload while probe registered */
1452 ret = try_module_get(event_enable_file->event_call->mod);
1458 ret = trace_event_enable_disable(event_enable_file, 1, 1);
1461 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1463 * The above returns on success the # of functions enabled,
1464 * but if it didn't find any functions it returns zero.
1465 * Consider no functions a failure too.
1472 /* Just return zero, not the number of enabled functions */
1474 event_trigger_free(trigger_ops, trigger_data);
1479 trace_event_enable_disable(event_enable_file, 0, 1);
1481 module_put(event_enable_file->event_call->mod);
1483 if (cmd_ops->set_filter)
1484 cmd_ops->set_filter(NULL, trigger_data, NULL);
1485 event_trigger_free(trigger_ops, trigger_data);
1490 int event_enable_register_trigger(char *glob,
1491 struct event_trigger_ops *ops,
1492 struct event_trigger_data *data,
1493 struct trace_event_file *file)
1495 struct enable_trigger_data *enable_data = data->private_data;
1496 struct enable_trigger_data *test_enable_data;
1497 struct event_trigger_data *test;
1500 list_for_each_entry_rcu(test, &file->triggers, list) {
1501 test_enable_data = test->private_data;
1502 if (test_enable_data &&
1503 (test->cmd_ops->trigger_type ==
1504 data->cmd_ops->trigger_type) &&
1505 (test_enable_data->file == enable_data->file)) {
1511 if (data->ops->init) {
1512 ret = data->ops->init(data->ops, data);
1517 list_add_rcu(&data->list, &file->triggers);
1520 update_cond_flag(file);
1521 if (trace_event_trigger_enable_disable(file, 1) < 0) {
1522 list_del_rcu(&data->list);
1523 update_cond_flag(file);
1530 void event_enable_unregister_trigger(char *glob,
1531 struct event_trigger_ops *ops,
1532 struct event_trigger_data *test,
1533 struct trace_event_file *file)
1535 struct enable_trigger_data *test_enable_data = test->private_data;
1536 struct enable_trigger_data *enable_data;
1537 struct event_trigger_data *data;
1538 bool unregistered = false;
1540 list_for_each_entry_rcu(data, &file->triggers, list) {
1541 enable_data = data->private_data;
1543 (data->cmd_ops->trigger_type ==
1544 test->cmd_ops->trigger_type) &&
1545 (enable_data->file == test_enable_data->file)) {
1546 unregistered = true;
1547 list_del_rcu(&data->list);
1548 trace_event_trigger_enable_disable(file, 0);
1549 update_cond_flag(file);
1554 if (unregistered && data->ops->free)
1555 data->ops->free(data->ops, data);
1558 static struct event_trigger_ops *
1559 event_enable_get_trigger_ops(char *cmd, char *param)
1561 struct event_trigger_ops *ops;
1564 #ifdef CONFIG_HIST_TRIGGERS
1565 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1566 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1568 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1571 ops = param ? &event_enable_count_trigger_ops :
1572 &event_enable_trigger_ops;
1574 ops = param ? &event_disable_count_trigger_ops :
1575 &event_disable_trigger_ops;
1580 static struct event_command trigger_enable_cmd = {
1581 .name = ENABLE_EVENT_STR,
1582 .trigger_type = ETT_EVENT_ENABLE,
1583 .func = event_enable_trigger_func,
1584 .reg = event_enable_register_trigger,
1585 .unreg = event_enable_unregister_trigger,
1586 .get_trigger_ops = event_enable_get_trigger_ops,
1587 .set_filter = set_trigger_filter,
1590 static struct event_command trigger_disable_cmd = {
1591 .name = DISABLE_EVENT_STR,
1592 .trigger_type = ETT_EVENT_ENABLE,
1593 .func = event_enable_trigger_func,
1594 .reg = event_enable_register_trigger,
1595 .unreg = event_enable_unregister_trigger,
1596 .get_trigger_ops = event_enable_get_trigger_ops,
1597 .set_filter = set_trigger_filter,
1600 static __init void unregister_trigger_enable_disable_cmds(void)
1602 unregister_event_command(&trigger_enable_cmd);
1603 unregister_event_command(&trigger_disable_cmd);
1606 static __init int register_trigger_enable_disable_cmds(void)
1610 ret = register_event_command(&trigger_enable_cmd);
1611 if (WARN_ON(ret < 0))
1613 ret = register_event_command(&trigger_disable_cmd);
1614 if (WARN_ON(ret < 0))
1615 unregister_trigger_enable_disable_cmds();
1620 static __init int register_trigger_traceon_traceoff_cmds(void)
1624 ret = register_event_command(&trigger_traceon_cmd);
1625 if (WARN_ON(ret < 0))
1627 ret = register_event_command(&trigger_traceoff_cmd);
1628 if (WARN_ON(ret < 0))
1629 unregister_trigger_traceon_traceoff_cmds();
1634 __init int register_trigger_cmds(void)
1636 register_trigger_traceon_traceoff_cmds();
1637 register_trigger_snapshot_cmd();
1638 register_trigger_stacktrace_cmd();
1639 register_trigger_enable_disable_cmds();
1640 register_trigger_hist_enable_disable_cmds();
1641 register_trigger_hist_cmd();