4 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
6 * - Added format output of fields of the trace point.
7 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
11 #define pr_fmt(fmt) fmt
13 #include <linux/workqueue.h>
14 #include <linux/spinlock.h>
15 #include <linux/kthread.h>
16 #include <linux/tracefs.h>
17 #include <linux/uaccess.h>
18 #include <linux/bsearch.h>
19 #include <linux/module.h>
20 #include <linux/ctype.h>
21 #include <linux/sort.h>
22 #include <linux/slab.h>
23 #include <linux/delay.h>
25 #include <trace/events/sched.h>
27 #include <asm/setup.h>
29 #include "trace_output.h"
32 #define TRACE_SYSTEM "TRACE_SYSTEM"
34 DEFINE_MUTEX(event_mutex);
36 LIST_HEAD(ftrace_events);
37 static LIST_HEAD(ftrace_generic_fields);
38 static LIST_HEAD(ftrace_common_fields);
40 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
42 static struct kmem_cache *field_cachep;
43 static struct kmem_cache *file_cachep;
45 static inline int system_refcount(struct event_subsystem *system)
47 return system->ref_count;
50 static int system_refcount_inc(struct event_subsystem *system)
52 return system->ref_count++;
55 static int system_refcount_dec(struct event_subsystem *system)
57 return --system->ref_count;
60 /* Double loops, do not use break, only goto's work */
61 #define do_for_each_event_file(tr, file) \
62 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
63 list_for_each_entry(file, &tr->events, list)
65 #define do_for_each_event_file_safe(tr, file) \
66 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
67 struct trace_event_file *___n; \
68 list_for_each_entry_safe(file, ___n, &tr->events, list)
70 #define while_for_each_event_file() \
73 static struct list_head *
74 trace_get_fields(struct trace_event_call *event_call)
76 if (!event_call->class->get_fields)
77 return &event_call->class->fields;
78 return event_call->class->get_fields(event_call);
81 static struct ftrace_event_field *
82 __find_event_field(struct list_head *head, char *name)
84 struct ftrace_event_field *field;
86 list_for_each_entry(field, head, link) {
87 if (!strcmp(field->name, name))
94 struct ftrace_event_field *
95 trace_find_event_field(struct trace_event_call *call, char *name)
97 struct ftrace_event_field *field;
98 struct list_head *head;
100 field = __find_event_field(&ftrace_generic_fields, name);
104 field = __find_event_field(&ftrace_common_fields, name);
108 head = trace_get_fields(call);
109 return __find_event_field(head, name);
112 static int __trace_define_field(struct list_head *head, const char *type,
113 const char *name, int offset, int size,
114 int is_signed, int filter_type)
116 struct ftrace_event_field *field;
118 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
125 if (filter_type == FILTER_OTHER)
126 field->filter_type = filter_assign_type(type);
128 field->filter_type = filter_type;
130 field->offset = offset;
132 field->is_signed = is_signed;
134 list_add(&field->link, head);
139 int trace_define_field(struct trace_event_call *call, const char *type,
140 const char *name, int offset, int size, int is_signed,
143 struct list_head *head;
145 if (WARN_ON(!call->class))
148 head = trace_get_fields(call);
149 return __trace_define_field(head, type, name, offset, size,
150 is_signed, filter_type);
152 EXPORT_SYMBOL_GPL(trace_define_field);
154 #define __generic_field(type, item, filter_type) \
155 ret = __trace_define_field(&ftrace_generic_fields, #type, \
156 #item, 0, 0, is_signed_type(type), \
161 #define __common_field(type, item) \
162 ret = __trace_define_field(&ftrace_common_fields, #type, \
164 offsetof(typeof(ent), item), \
166 is_signed_type(type), FILTER_OTHER); \
170 static int trace_define_generic_fields(void)
174 __generic_field(int, cpu, FILTER_OTHER);
175 __generic_field(char *, comm, FILTER_PTR_STRING);
180 static int trace_define_common_fields(void)
183 struct trace_entry ent;
185 __common_field(unsigned short, type);
186 __common_field(unsigned char, flags);
187 __common_field(unsigned char, preempt_count);
188 __common_field(int, pid);
193 static void trace_destroy_fields(struct trace_event_call *call)
195 struct ftrace_event_field *field, *next;
196 struct list_head *head;
198 head = trace_get_fields(call);
199 list_for_each_entry_safe(field, next, head, link) {
200 list_del(&field->link);
201 kmem_cache_free(field_cachep, field);
205 int trace_event_raw_init(struct trace_event_call *call)
209 id = register_trace_event(&call->event);
215 EXPORT_SYMBOL_GPL(trace_event_raw_init);
217 bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
219 struct trace_array *tr = trace_file->tr;
220 struct trace_array_cpu *data;
221 struct trace_pid_list *pid_list;
223 pid_list = rcu_dereference_sched(tr->filtered_pids);
227 data = this_cpu_ptr(tr->trace_buffer.data);
229 return data->ignore_pid;
231 EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
233 void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
234 struct trace_event_file *trace_file,
237 struct trace_event_call *event_call = trace_file->event_call;
239 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
240 trace_event_ignore_this_pid(trace_file))
243 local_save_flags(fbuffer->flags);
244 fbuffer->pc = preempt_count();
245 fbuffer->trace_file = trace_file;
248 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
249 event_call->event.type, len,
250 fbuffer->flags, fbuffer->pc);
254 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
255 return fbuffer->entry;
257 EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
259 static DEFINE_SPINLOCK(tracepoint_iter_lock);
261 static void output_printk(struct trace_event_buffer *fbuffer)
263 struct trace_event_call *event_call;
264 struct trace_event *event;
266 struct trace_iterator *iter = tracepoint_print_iter;
271 event_call = fbuffer->trace_file->event_call;
272 if (!event_call || !event_call->event.funcs ||
273 !event_call->event.funcs->trace)
276 event = &fbuffer->trace_file->event_call->event;
278 spin_lock_irqsave(&tracepoint_iter_lock, flags);
279 trace_seq_init(&iter->seq);
280 iter->ent = fbuffer->entry;
281 event_call->event.funcs->trace(iter, 0, event);
282 trace_seq_putc(&iter->seq, 0);
283 printk("%s", iter->seq.buffer);
285 spin_unlock_irqrestore(&tracepoint_iter_lock, flags);
288 void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)
290 if (tracepoint_printk)
291 output_printk(fbuffer);
293 event_trigger_unlock_commit(fbuffer->trace_file, fbuffer->buffer,
294 fbuffer->event, fbuffer->entry,
295 fbuffer->flags, fbuffer->pc);
297 EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
299 int trace_event_reg(struct trace_event_call *call,
300 enum trace_reg type, void *data)
302 struct trace_event_file *file = data;
304 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
306 case TRACE_REG_REGISTER:
307 return tracepoint_probe_register(call->tp,
310 case TRACE_REG_UNREGISTER:
311 tracepoint_probe_unregister(call->tp,
316 #ifdef CONFIG_PERF_EVENTS
317 case TRACE_REG_PERF_REGISTER:
318 return tracepoint_probe_register(call->tp,
319 call->class->perf_probe,
321 case TRACE_REG_PERF_UNREGISTER:
322 tracepoint_probe_unregister(call->tp,
323 call->class->perf_probe,
326 case TRACE_REG_PERF_OPEN:
327 case TRACE_REG_PERF_CLOSE:
328 case TRACE_REG_PERF_ADD:
329 case TRACE_REG_PERF_DEL:
335 EXPORT_SYMBOL_GPL(trace_event_reg);
337 void trace_event_enable_cmd_record(bool enable)
339 struct trace_event_file *file;
340 struct trace_array *tr;
342 mutex_lock(&event_mutex);
343 do_for_each_event_file(tr, file) {
345 if (!(file->flags & EVENT_FILE_FL_ENABLED))
349 tracing_start_cmdline_record();
350 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
352 tracing_stop_cmdline_record();
353 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
355 } while_for_each_event_file();
356 mutex_unlock(&event_mutex);
359 static int __ftrace_event_enable_disable(struct trace_event_file *file,
360 int enable, int soft_disable)
362 struct trace_event_call *call = file->event_call;
363 struct trace_array *tr = file->tr;
370 * When soft_disable is set and enable is cleared, the sm_ref
371 * reference counter is decremented. If it reaches 0, we want
372 * to clear the SOFT_DISABLED flag but leave the event in the
373 * state that it was. That is, if the event was enabled and
374 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
375 * is set we do not want the event to be enabled before we
378 * When soft_disable is not set but the SOFT_MODE flag is,
379 * we do nothing. Do not disable the tracepoint, otherwise
380 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
383 if (atomic_dec_return(&file->sm_ref) > 0)
385 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
386 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
388 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
390 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
391 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
392 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
393 tracing_stop_cmdline_record();
394 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
396 call->class->reg(call, TRACE_REG_UNREGISTER, file);
398 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
399 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
400 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
402 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
406 * When soft_disable is set and enable is set, we want to
407 * register the tracepoint for the event, but leave the event
408 * as is. That means, if the event was already enabled, we do
409 * nothing (but set SOFT_MODE). If the event is disabled, we
410 * set SOFT_DISABLED before enabling the event tracepoint, so
411 * it still seems to be disabled.
414 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
416 if (atomic_inc_return(&file->sm_ref) > 1)
418 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
421 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
423 /* Keep the event disabled, when going to SOFT_MODE. */
425 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
427 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
428 tracing_start_cmdline_record();
429 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
431 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
433 tracing_stop_cmdline_record();
434 pr_info("event trace: Could not enable event "
435 "%s\n", trace_event_name(call));
438 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
440 /* WAS_ENABLED gets set but never cleared. */
441 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
449 int trace_event_enable_disable(struct trace_event_file *file,
450 int enable, int soft_disable)
452 return __ftrace_event_enable_disable(file, enable, soft_disable);
455 static int ftrace_event_enable_disable(struct trace_event_file *file,
458 return __ftrace_event_enable_disable(file, enable, 0);
461 static void ftrace_clear_events(struct trace_array *tr)
463 struct trace_event_file *file;
465 mutex_lock(&event_mutex);
466 list_for_each_entry(file, &tr->events, list) {
467 ftrace_event_enable_disable(file, 0);
469 mutex_unlock(&event_mutex);
472 static int cmp_pid(const void *key, const void *elt)
474 const pid_t *search_pid = key;
475 const pid_t *pid = elt;
477 if (*search_pid == *pid)
479 if (*search_pid < *pid)
485 check_ignore_pid(struct trace_pid_list *filtered_pids, struct task_struct *task)
491 * Return false, because if filtered_pids does not exist,
492 * all pids are good to trace.
497 search_pid = task->pid;
499 pid = bsearch(&search_pid, filtered_pids->pids,
500 filtered_pids->nr_pids, sizeof(pid_t),
509 event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
510 struct task_struct *prev, struct task_struct *next)
512 struct trace_array *tr = data;
513 struct trace_pid_list *pid_list;
515 pid_list = rcu_dereference_sched(tr->filtered_pids);
517 this_cpu_write(tr->trace_buffer.data->ignore_pid,
518 check_ignore_pid(pid_list, prev) &&
519 check_ignore_pid(pid_list, next));
523 event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
524 struct task_struct *prev, struct task_struct *next)
526 struct trace_array *tr = data;
527 struct trace_pid_list *pid_list;
529 pid_list = rcu_dereference_sched(tr->filtered_pids);
531 this_cpu_write(tr->trace_buffer.data->ignore_pid,
532 check_ignore_pid(pid_list, next));
536 event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
538 struct trace_array *tr = data;
539 struct trace_pid_list *pid_list;
541 /* Nothing to do if we are already tracing */
542 if (!this_cpu_read(tr->trace_buffer.data->ignore_pid))
545 pid_list = rcu_dereference_sched(tr->filtered_pids);
547 this_cpu_write(tr->trace_buffer.data->ignore_pid,
548 check_ignore_pid(pid_list, task));
552 event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
554 struct trace_array *tr = data;
555 struct trace_pid_list *pid_list;
557 /* Nothing to do if we are not tracing */
558 if (this_cpu_read(tr->trace_buffer.data->ignore_pid))
561 pid_list = rcu_dereference_sched(tr->filtered_pids);
563 /* Set tracing if current is enabled */
564 this_cpu_write(tr->trace_buffer.data->ignore_pid,
565 check_ignore_pid(pid_list, current));
568 static void __ftrace_clear_event_pids(struct trace_array *tr)
570 struct trace_pid_list *pid_list;
571 struct trace_event_file *file;
574 pid_list = rcu_dereference_protected(tr->filtered_pids,
575 lockdep_is_held(&event_mutex));
579 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
580 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
582 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
583 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
585 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
586 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
588 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
589 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
591 list_for_each_entry(file, &tr->events, list) {
592 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
595 for_each_possible_cpu(cpu)
596 per_cpu_ptr(tr->trace_buffer.data, cpu)->ignore_pid = false;
598 rcu_assign_pointer(tr->filtered_pids, NULL);
600 /* Wait till all users are no longer using pid filtering */
603 free_pages((unsigned long)pid_list->pids, pid_list->order);
607 static void ftrace_clear_event_pids(struct trace_array *tr)
609 mutex_lock(&event_mutex);
610 __ftrace_clear_event_pids(tr);
611 mutex_unlock(&event_mutex);
614 static void __put_system(struct event_subsystem *system)
616 struct event_filter *filter = system->filter;
618 WARN_ON_ONCE(system_refcount(system) == 0);
619 if (system_refcount_dec(system))
622 list_del(&system->list);
625 kfree(filter->filter_string);
628 kfree_const(system->name);
632 static void __get_system(struct event_subsystem *system)
634 WARN_ON_ONCE(system_refcount(system) == 0);
635 system_refcount_inc(system);
638 static void __get_system_dir(struct trace_subsystem_dir *dir)
640 WARN_ON_ONCE(dir->ref_count == 0);
642 __get_system(dir->subsystem);
645 static void __put_system_dir(struct trace_subsystem_dir *dir)
647 WARN_ON_ONCE(dir->ref_count == 0);
648 /* If the subsystem is about to be freed, the dir must be too */
649 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
651 __put_system(dir->subsystem);
652 if (!--dir->ref_count)
656 static void put_system(struct trace_subsystem_dir *dir)
658 mutex_lock(&event_mutex);
659 __put_system_dir(dir);
660 mutex_unlock(&event_mutex);
663 static void remove_subsystem(struct trace_subsystem_dir *dir)
668 if (!--dir->nr_events) {
669 tracefs_remove_recursive(dir->entry);
670 list_del(&dir->list);
671 __put_system_dir(dir);
675 static void remove_event_file_dir(struct trace_event_file *file)
677 struct dentry *dir = file->dir;
678 struct dentry *child;
681 spin_lock(&dir->d_lock); /* probably unneeded */
682 list_for_each_entry(child, &dir->d_subdirs, d_child) {
683 if (d_really_is_positive(child)) /* probably unneeded */
684 d_inode(child)->i_private = NULL;
686 spin_unlock(&dir->d_lock);
688 tracefs_remove_recursive(dir);
691 list_del(&file->list);
692 remove_subsystem(file->system);
693 free_event_filter(file->filter);
694 kmem_cache_free(file_cachep, file);
698 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
701 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
702 const char *sub, const char *event, int set)
704 struct trace_event_file *file;
705 struct trace_event_call *call;
709 list_for_each_entry(file, &tr->events, list) {
711 call = file->event_call;
712 name = trace_event_name(call);
714 if (!name || !call->class || !call->class->reg)
717 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
721 strcmp(match, name) != 0 &&
722 strcmp(match, call->class->system) != 0)
725 if (sub && strcmp(sub, call->class->system) != 0)
728 if (event && strcmp(event, name) != 0)
731 ftrace_event_enable_disable(file, set);
739 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
740 const char *sub, const char *event, int set)
744 mutex_lock(&event_mutex);
745 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
746 mutex_unlock(&event_mutex);
751 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
753 char *event = NULL, *sub = NULL, *match;
757 * The buf format can be <subsystem>:<event-name>
758 * *:<event-name> means any event by that name.
759 * :<event-name> is the same.
761 * <subsystem>:* means all events in that subsystem
762 * <subsystem>: means the same.
764 * <name> (no ':') means all events in a subsystem with
765 * the name <name> or any event that matches <name>
768 match = strsep(&buf, ":");
774 if (!strlen(sub) || strcmp(sub, "*") == 0)
776 if (!strlen(event) || strcmp(event, "*") == 0)
780 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
782 /* Put back the colon to allow this to be called again */
790 * trace_set_clr_event - enable or disable an event
791 * @system: system name to match (NULL for any system)
792 * @event: event name to match (NULL for all events, within system)
793 * @set: 1 to enable, 0 to disable
795 * This is a way for other parts of the kernel to enable or disable
798 * Returns 0 on success, -EINVAL if the parameters do not match any
801 int trace_set_clr_event(const char *system, const char *event, int set)
803 struct trace_array *tr = top_trace_array();
808 return __ftrace_set_clr_event(tr, NULL, system, event, set);
810 EXPORT_SYMBOL_GPL(trace_set_clr_event);
812 /* 128 should be much more than enough */
813 #define EVENT_BUF_SIZE 127
816 ftrace_event_write(struct file *file, const char __user *ubuf,
817 size_t cnt, loff_t *ppos)
819 struct trace_parser parser;
820 struct seq_file *m = file->private_data;
821 struct trace_array *tr = m->private;
827 ret = tracing_update_buffers();
831 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
834 read = trace_get_user(&parser, ubuf, cnt, ppos);
836 if (read >= 0 && trace_parser_loaded((&parser))) {
839 if (*parser.buffer == '!')
842 parser.buffer[parser.idx] = 0;
844 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
852 trace_parser_put(&parser);
858 t_next(struct seq_file *m, void *v, loff_t *pos)
860 struct trace_event_file *file = v;
861 struct trace_event_call *call;
862 struct trace_array *tr = m->private;
866 list_for_each_entry_continue(file, &tr->events, list) {
867 call = file->event_call;
869 * The ftrace subsystem is for showing formats only.
870 * They can not be enabled or disabled via the event files.
872 if (call->class && call->class->reg)
879 static void *t_start(struct seq_file *m, loff_t *pos)
881 struct trace_event_file *file;
882 struct trace_array *tr = m->private;
885 mutex_lock(&event_mutex);
887 file = list_entry(&tr->events, struct trace_event_file, list);
888 for (l = 0; l <= *pos; ) {
889 file = t_next(m, file, &l);
897 s_next(struct seq_file *m, void *v, loff_t *pos)
899 struct trace_event_file *file = v;
900 struct trace_array *tr = m->private;
904 list_for_each_entry_continue(file, &tr->events, list) {
905 if (file->flags & EVENT_FILE_FL_ENABLED)
912 static void *s_start(struct seq_file *m, loff_t *pos)
914 struct trace_event_file *file;
915 struct trace_array *tr = m->private;
918 mutex_lock(&event_mutex);
920 file = list_entry(&tr->events, struct trace_event_file, list);
921 for (l = 0; l <= *pos; ) {
922 file = s_next(m, file, &l);
929 static int t_show(struct seq_file *m, void *v)
931 struct trace_event_file *file = v;
932 struct trace_event_call *call = file->event_call;
934 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
935 seq_printf(m, "%s:", call->class->system);
936 seq_printf(m, "%s\n", trace_event_name(call));
941 static void t_stop(struct seq_file *m, void *p)
943 mutex_unlock(&event_mutex);
946 static void *p_start(struct seq_file *m, loff_t *pos)
949 struct trace_pid_list *pid_list;
950 struct trace_array *tr = m->private;
953 * Grab the mutex, to keep calls to p_next() having the same
954 * tr->filtered_pids as p_start() has.
955 * If we just passed the tr->filtered_pids around, then RCU would
956 * have been enough, but doing that makes things more complex.
958 mutex_lock(&event_mutex);
959 rcu_read_lock_sched();
961 pid_list = rcu_dereference_sched(tr->filtered_pids);
963 if (!pid_list || *pos >= pid_list->nr_pids)
966 return (void *)&pid_list->pids[*pos];
969 static void p_stop(struct seq_file *m, void *p)
972 rcu_read_unlock_sched();
973 mutex_unlock(&event_mutex);
977 p_next(struct seq_file *m, void *v, loff_t *pos)
979 struct trace_array *tr = m->private;
980 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
984 if (*pos >= pid_list->nr_pids)
987 return (void *)&pid_list->pids[*pos];
990 static int p_show(struct seq_file *m, void *v)
994 seq_printf(m, "%d\n", *pid);
999 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1002 struct trace_event_file *file;
1003 unsigned long flags;
1006 mutex_lock(&event_mutex);
1007 file = event_file_data(filp);
1009 flags = file->flags;
1010 mutex_unlock(&event_mutex);
1015 if (flags & EVENT_FILE_FL_ENABLED &&
1016 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1019 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1020 flags & EVENT_FILE_FL_SOFT_MODE)
1025 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1029 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1032 struct trace_event_file *file;
1036 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1040 ret = tracing_update_buffers();
1048 mutex_lock(&event_mutex);
1049 file = event_file_data(filp);
1051 ret = ftrace_event_enable_disable(file, val);
1052 mutex_unlock(&event_mutex);
1061 return ret ? ret : cnt;
1065 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1068 const char set_to_char[4] = { '?', '0', '1', 'X' };
1069 struct trace_subsystem_dir *dir = filp->private_data;
1070 struct event_subsystem *system = dir->subsystem;
1071 struct trace_event_call *call;
1072 struct trace_event_file *file;
1073 struct trace_array *tr = dir->tr;
1078 mutex_lock(&event_mutex);
1079 list_for_each_entry(file, &tr->events, list) {
1080 call = file->event_call;
1081 if (!trace_event_name(call) || !call->class || !call->class->reg)
1084 if (system && strcmp(call->class->system, system->name) != 0)
1088 * We need to find out if all the events are set
1089 * or if all events or cleared, or if we have
1092 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1095 * If we have a mixture, no need to look further.
1100 mutex_unlock(&event_mutex);
1102 buf[0] = set_to_char[set];
1105 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1111 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1114 struct trace_subsystem_dir *dir = filp->private_data;
1115 struct event_subsystem *system = dir->subsystem;
1116 const char *name = NULL;
1120 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1124 ret = tracing_update_buffers();
1128 if (val != 0 && val != 1)
1132 * Opening of "enable" adds a ref count to system,
1133 * so the name is safe to use.
1136 name = system->name;
1138 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1152 FORMAT_FIELD_SEPERATOR = 2,
1153 FORMAT_PRINTFMT = 3,
1156 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1158 struct trace_event_call *call = event_file_data(m->private);
1159 struct list_head *common_head = &ftrace_common_fields;
1160 struct list_head *head = trace_get_fields(call);
1161 struct list_head *node = v;
1165 switch ((unsigned long)v) {
1170 case FORMAT_FIELD_SEPERATOR:
1174 case FORMAT_PRINTFMT:
1180 if (node == common_head)
1181 return (void *)FORMAT_FIELD_SEPERATOR;
1182 else if (node == head)
1183 return (void *)FORMAT_PRINTFMT;
1188 static int f_show(struct seq_file *m, void *v)
1190 struct trace_event_call *call = event_file_data(m->private);
1191 struct ftrace_event_field *field;
1192 const char *array_descriptor;
1194 switch ((unsigned long)v) {
1196 seq_printf(m, "name: %s\n", trace_event_name(call));
1197 seq_printf(m, "ID: %d\n", call->event.type);
1198 seq_puts(m, "format:\n");
1201 case FORMAT_FIELD_SEPERATOR:
1205 case FORMAT_PRINTFMT:
1206 seq_printf(m, "\nprint fmt: %s\n",
1211 field = list_entry(v, struct ftrace_event_field, link);
1213 * Smartly shows the array type(except dynamic array).
1216 * If TYPE := TYPE[LEN], it is shown:
1217 * field:TYPE VAR[LEN]
1219 array_descriptor = strchr(field->type, '[');
1221 if (!strncmp(field->type, "__data_loc", 10))
1222 array_descriptor = NULL;
1224 if (!array_descriptor)
1225 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1226 field->type, field->name, field->offset,
1227 field->size, !!field->is_signed);
1229 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1230 (int)(array_descriptor - field->type),
1231 field->type, field->name,
1232 array_descriptor, field->offset,
1233 field->size, !!field->is_signed);
1238 static void *f_start(struct seq_file *m, loff_t *pos)
1240 void *p = (void *)FORMAT_HEADER;
1243 /* ->stop() is called even if ->start() fails */
1244 mutex_lock(&event_mutex);
1245 if (!event_file_data(m->private))
1246 return ERR_PTR(-ENODEV);
1248 while (l < *pos && p)
1249 p = f_next(m, p, &l);
1254 static void f_stop(struct seq_file *m, void *p)
1256 mutex_unlock(&event_mutex);
1259 static const struct seq_operations trace_format_seq_ops = {
1266 static int trace_format_open(struct inode *inode, struct file *file)
1271 ret = seq_open(file, &trace_format_seq_ops);
1275 m = file->private_data;
1282 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1284 int id = (long)event_file_data(filp);
1294 len = sprintf(buf, "%d\n", id);
1296 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1300 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1303 struct trace_event_file *file;
1304 struct trace_seq *s;
1310 s = kmalloc(sizeof(*s), GFP_KERNEL);
1317 mutex_lock(&event_mutex);
1318 file = event_file_data(filp);
1320 print_event_filter(file, s);
1321 mutex_unlock(&event_mutex);
1324 r = simple_read_from_buffer(ubuf, cnt, ppos,
1325 s->buffer, trace_seq_used(s));
1333 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1336 struct trace_event_file *file;
1340 if (cnt >= PAGE_SIZE)
1343 buf = (char *)__get_free_page(GFP_TEMPORARY);
1347 if (copy_from_user(buf, ubuf, cnt)) {
1348 free_page((unsigned long) buf);
1353 mutex_lock(&event_mutex);
1354 file = event_file_data(filp);
1356 err = apply_event_filter(file, buf);
1357 mutex_unlock(&event_mutex);
1359 free_page((unsigned long) buf);
1368 static LIST_HEAD(event_subsystems);
1370 static int subsystem_open(struct inode *inode, struct file *filp)
1372 struct event_subsystem *system = NULL;
1373 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1374 struct trace_array *tr;
1377 if (tracing_is_disabled())
1380 /* Make sure the system still exists */
1381 mutex_lock(&trace_types_lock);
1382 mutex_lock(&event_mutex);
1383 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1384 list_for_each_entry(dir, &tr->systems, list) {
1385 if (dir == inode->i_private) {
1386 /* Don't open systems with no events */
1387 if (dir->nr_events) {
1388 __get_system_dir(dir);
1389 system = dir->subsystem;
1396 mutex_unlock(&event_mutex);
1397 mutex_unlock(&trace_types_lock);
1402 /* Some versions of gcc think dir can be uninitialized here */
1405 /* Still need to increment the ref count of the system */
1406 if (trace_array_get(tr) < 0) {
1411 ret = tracing_open_generic(inode, filp);
1413 trace_array_put(tr);
1420 static int system_tr_open(struct inode *inode, struct file *filp)
1422 struct trace_subsystem_dir *dir;
1423 struct trace_array *tr = inode->i_private;
1426 if (tracing_is_disabled())
1429 if (trace_array_get(tr) < 0)
1432 /* Make a temporary dir that has no system but points to tr */
1433 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1435 trace_array_put(tr);
1441 ret = tracing_open_generic(inode, filp);
1443 trace_array_put(tr);
1448 filp->private_data = dir;
1453 static int subsystem_release(struct inode *inode, struct file *file)
1455 struct trace_subsystem_dir *dir = file->private_data;
1457 trace_array_put(dir->tr);
1460 * If dir->subsystem is NULL, then this is a temporary
1461 * descriptor that was made for a trace_array to enable
1473 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1476 struct trace_subsystem_dir *dir = filp->private_data;
1477 struct event_subsystem *system = dir->subsystem;
1478 struct trace_seq *s;
1484 s = kmalloc(sizeof(*s), GFP_KERNEL);
1490 print_subsystem_event_filter(system, s);
1491 r = simple_read_from_buffer(ubuf, cnt, ppos,
1492 s->buffer, trace_seq_used(s));
1500 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1503 struct trace_subsystem_dir *dir = filp->private_data;
1507 if (cnt >= PAGE_SIZE)
1510 buf = (char *)__get_free_page(GFP_TEMPORARY);
1514 if (copy_from_user(buf, ubuf, cnt)) {
1515 free_page((unsigned long) buf);
1520 err = apply_subsystem_event_filter(dir, buf);
1521 free_page((unsigned long) buf);
1531 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1533 int (*func)(struct trace_seq *s) = filp->private_data;
1534 struct trace_seq *s;
1540 s = kmalloc(sizeof(*s), GFP_KERNEL);
1547 r = simple_read_from_buffer(ubuf, cnt, ppos,
1548 s->buffer, trace_seq_used(s));
1555 static int max_pids(struct trace_pid_list *pid_list)
1557 return (PAGE_SIZE << pid_list->order) / sizeof(pid_t);
1560 static void ignore_task_cpu(void *data)
1562 struct trace_array *tr = data;
1563 struct trace_pid_list *pid_list;
1566 * This function is called by on_each_cpu() while the
1567 * event_mutex is held.
1569 pid_list = rcu_dereference_protected(tr->filtered_pids,
1570 mutex_is_locked(&event_mutex));
1572 this_cpu_write(tr->trace_buffer.data->ignore_pid,
1573 check_ignore_pid(pid_list, current));
1577 ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1578 size_t cnt, loff_t *ppos)
1580 struct seq_file *m = filp->private_data;
1581 struct trace_array *tr = m->private;
1582 struct trace_pid_list *filtered_pids = NULL;
1583 struct trace_pid_list *pid_list = NULL;
1584 struct trace_event_file *file;
1585 struct trace_parser parser;
1596 ret = tracing_update_buffers();
1600 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
1603 mutex_lock(&event_mutex);
1605 * Load as many pids into the array before doing a
1606 * swap from the tr->filtered_pids to the new list.
1612 ret = trace_get_user(&parser, ubuf, cnt, &this_pos);
1613 if (ret < 0 || !trace_parser_loaded(&parser))
1620 parser.buffer[parser.idx] = 0;
1623 if (kstrtoul(parser.buffer, 0, &val))
1632 pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL);
1636 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1637 lockdep_is_held(&event_mutex));
1639 pid_list->order = filtered_pids->order;
1641 pid_list->order = 0;
1643 pid_list->pids = (void *)__get_free_pages(GFP_KERNEL,
1645 if (!pid_list->pids)
1648 if (filtered_pids) {
1649 pid_list->nr_pids = filtered_pids->nr_pids;
1650 memcpy(pid_list->pids, filtered_pids->pids,
1651 pid_list->nr_pids * sizeof(pid_t));
1653 pid_list->nr_pids = 0;
1656 if (pid_list->nr_pids >= max_pids(pid_list)) {
1659 pid_page = (void *)__get_free_pages(GFP_KERNEL,
1660 pid_list->order + 1);
1663 memcpy(pid_page, pid_list->pids,
1664 pid_list->nr_pids * sizeof(pid_t));
1665 free_pages((unsigned long)pid_list->pids, pid_list->order);
1668 pid_list->pids = pid_page;
1671 pid_list->pids[pid_list->nr_pids++] = pid;
1672 trace_parser_clear(&parser);
1675 trace_parser_put(&parser);
1679 free_pages((unsigned long)pid_list->pids, pid_list->order);
1681 mutex_unlock(&event_mutex);
1686 mutex_unlock(&event_mutex);
1690 sort(pid_list->pids, pid_list->nr_pids, sizeof(pid_t), cmp_pid, NULL);
1692 /* Remove duplicates */
1693 for (i = 1; i < pid_list->nr_pids; i++) {
1696 while (i < pid_list->nr_pids &&
1697 pid_list->pids[i - 1] == pid_list->pids[i])
1701 if (i < pid_list->nr_pids) {
1702 memmove(&pid_list->pids[start], &pid_list->pids[i],
1703 (pid_list->nr_pids - i) * sizeof(pid_t));
1704 pid_list->nr_pids -= i - start;
1707 pid_list->nr_pids = start;
1711 rcu_assign_pointer(tr->filtered_pids, pid_list);
1713 list_for_each_entry(file, &tr->events, list) {
1714 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1717 if (filtered_pids) {
1718 synchronize_sched();
1720 free_pages((unsigned long)filtered_pids->pids, filtered_pids->order);
1721 kfree(filtered_pids);
1724 * Register a probe that is called before all other probes
1725 * to set ignore_pid if next or prev do not match.
1726 * Register a probe this is called after all other probes
1727 * to only keep ignore_pid set if next pid matches.
1729 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1731 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1734 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1736 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1739 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1741 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1744 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1746 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1751 * Ignoring of pids is done at task switch. But we have to
1752 * check for those tasks that are currently running.
1753 * Always do this in case a pid was appended or removed.
1755 on_each_cpu(ignore_task_cpu, tr, 1);
1757 mutex_unlock(&event_mutex);
1765 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1766 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1767 static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
1768 static int ftrace_event_release(struct inode *inode, struct file *file);
1770 static const struct seq_operations show_event_seq_ops = {
1777 static const struct seq_operations show_set_event_seq_ops = {
1784 static const struct seq_operations show_set_pid_seq_ops = {
1791 static const struct file_operations ftrace_avail_fops = {
1792 .open = ftrace_event_avail_open,
1794 .llseek = seq_lseek,
1795 .release = seq_release,
1798 static const struct file_operations ftrace_set_event_fops = {
1799 .open = ftrace_event_set_open,
1801 .write = ftrace_event_write,
1802 .llseek = seq_lseek,
1803 .release = ftrace_event_release,
1806 static const struct file_operations ftrace_set_event_pid_fops = {
1807 .open = ftrace_event_set_pid_open,
1809 .write = ftrace_event_pid_write,
1810 .llseek = seq_lseek,
1811 .release = ftrace_event_release,
1814 static const struct file_operations ftrace_enable_fops = {
1815 .open = tracing_open_generic,
1816 .read = event_enable_read,
1817 .write = event_enable_write,
1818 .llseek = default_llseek,
1821 static const struct file_operations ftrace_event_format_fops = {
1822 .open = trace_format_open,
1824 .llseek = seq_lseek,
1825 .release = seq_release,
1828 static const struct file_operations ftrace_event_id_fops = {
1829 .read = event_id_read,
1830 .llseek = default_llseek,
1833 static const struct file_operations ftrace_event_filter_fops = {
1834 .open = tracing_open_generic,
1835 .read = event_filter_read,
1836 .write = event_filter_write,
1837 .llseek = default_llseek,
1840 static const struct file_operations ftrace_subsystem_filter_fops = {
1841 .open = subsystem_open,
1842 .read = subsystem_filter_read,
1843 .write = subsystem_filter_write,
1844 .llseek = default_llseek,
1845 .release = subsystem_release,
1848 static const struct file_operations ftrace_system_enable_fops = {
1849 .open = subsystem_open,
1850 .read = system_enable_read,
1851 .write = system_enable_write,
1852 .llseek = default_llseek,
1853 .release = subsystem_release,
1856 static const struct file_operations ftrace_tr_enable_fops = {
1857 .open = system_tr_open,
1858 .read = system_enable_read,
1859 .write = system_enable_write,
1860 .llseek = default_llseek,
1861 .release = subsystem_release,
1864 static const struct file_operations ftrace_show_header_fops = {
1865 .open = tracing_open_generic,
1866 .read = show_header,
1867 .llseek = default_llseek,
1871 ftrace_event_open(struct inode *inode, struct file *file,
1872 const struct seq_operations *seq_ops)
1877 ret = seq_open(file, seq_ops);
1880 m = file->private_data;
1881 /* copy tr over to seq ops */
1882 m->private = inode->i_private;
1887 static int ftrace_event_release(struct inode *inode, struct file *file)
1889 struct trace_array *tr = inode->i_private;
1891 trace_array_put(tr);
1893 return seq_release(inode, file);
1897 ftrace_event_avail_open(struct inode *inode, struct file *file)
1899 const struct seq_operations *seq_ops = &show_event_seq_ops;
1901 return ftrace_event_open(inode, file, seq_ops);
1905 ftrace_event_set_open(struct inode *inode, struct file *file)
1907 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1908 struct trace_array *tr = inode->i_private;
1911 if (trace_array_get(tr) < 0)
1914 if ((file->f_mode & FMODE_WRITE) &&
1915 (file->f_flags & O_TRUNC))
1916 ftrace_clear_events(tr);
1918 ret = ftrace_event_open(inode, file, seq_ops);
1920 trace_array_put(tr);
1925 ftrace_event_set_pid_open(struct inode *inode, struct file *file)
1927 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
1928 struct trace_array *tr = inode->i_private;
1931 if (trace_array_get(tr) < 0)
1934 if ((file->f_mode & FMODE_WRITE) &&
1935 (file->f_flags & O_TRUNC))
1936 ftrace_clear_event_pids(tr);
1938 ret = ftrace_event_open(inode, file, seq_ops);
1940 trace_array_put(tr);
1944 static struct event_subsystem *
1945 create_new_subsystem(const char *name)
1947 struct event_subsystem *system;
1949 /* need to create new entry */
1950 system = kmalloc(sizeof(*system), GFP_KERNEL);
1954 system->ref_count = 1;
1956 /* Only allocate if dynamic (kprobes and modules) */
1957 system->name = kstrdup_const(name, GFP_KERNEL);
1961 system->filter = NULL;
1963 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1964 if (!system->filter)
1967 list_add(&system->list, &event_subsystems);
1972 kfree_const(system->name);
1977 static struct dentry *
1978 event_subsystem_dir(struct trace_array *tr, const char *name,
1979 struct trace_event_file *file, struct dentry *parent)
1981 struct trace_subsystem_dir *dir;
1982 struct event_subsystem *system;
1983 struct dentry *entry;
1985 /* First see if we did not already create this dir */
1986 list_for_each_entry(dir, &tr->systems, list) {
1987 system = dir->subsystem;
1988 if (strcmp(system->name, name) == 0) {
1995 /* Now see if the system itself exists. */
1996 list_for_each_entry(system, &event_subsystems, list) {
1997 if (strcmp(system->name, name) == 0)
2000 /* Reset system variable when not found */
2001 if (&system->list == &event_subsystems)
2004 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
2009 system = create_new_subsystem(name);
2013 __get_system(system);
2015 dir->entry = tracefs_create_dir(name, parent);
2017 pr_warn("Failed to create system directory %s\n", name);
2018 __put_system(system);
2025 dir->subsystem = system;
2028 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
2029 &ftrace_subsystem_filter_fops);
2031 kfree(system->filter);
2032 system->filter = NULL;
2033 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
2036 trace_create_file("enable", 0644, dir->entry, dir,
2037 &ftrace_system_enable_fops);
2039 list_add(&dir->list, &tr->systems);
2046 /* Only print this message if failed on memory allocation */
2047 if (!dir || !system)
2048 pr_warn("No memory to create event subsystem %s\n", name);
2053 event_create_dir(struct dentry *parent, struct trace_event_file *file)
2055 struct trace_event_call *call = file->event_call;
2056 struct trace_array *tr = file->tr;
2057 struct list_head *head;
2058 struct dentry *d_events;
2063 * If the trace point header did not define TRACE_SYSTEM
2064 * then the system would be called "TRACE_SYSTEM".
2066 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
2067 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
2073 name = trace_event_name(call);
2074 file->dir = tracefs_create_dir(name, d_events);
2076 pr_warn("Could not create tracefs '%s' directory\n", name);
2080 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2081 trace_create_file("enable", 0644, file->dir, file,
2082 &ftrace_enable_fops);
2084 #ifdef CONFIG_PERF_EVENTS
2085 if (call->event.type && call->class->reg)
2086 trace_create_file("id", 0444, file->dir,
2087 (void *)(long)call->event.type,
2088 &ftrace_event_id_fops);
2092 * Other events may have the same class. Only update
2093 * the fields if they are not already defined.
2095 head = trace_get_fields(call);
2096 if (list_empty(head)) {
2097 ret = call->class->define_fields(call);
2099 pr_warn("Could not initialize trace point events/%s\n",
2104 trace_create_file("filter", 0644, file->dir, file,
2105 &ftrace_event_filter_fops);
2107 trace_create_file("trigger", 0644, file->dir, file,
2108 &event_trigger_fops);
2110 trace_create_file("format", 0444, file->dir, call,
2111 &ftrace_event_format_fops);
2116 static void remove_event_from_tracers(struct trace_event_call *call)
2118 struct trace_event_file *file;
2119 struct trace_array *tr;
2121 do_for_each_event_file_safe(tr, file) {
2122 if (file->event_call != call)
2125 remove_event_file_dir(file);
2127 * The do_for_each_event_file_safe() is
2128 * a double loop. After finding the call for this
2129 * trace_array, we use break to jump to the next
2133 } while_for_each_event_file();
2136 static void event_remove(struct trace_event_call *call)
2138 struct trace_array *tr;
2139 struct trace_event_file *file;
2141 do_for_each_event_file(tr, file) {
2142 if (file->event_call != call)
2144 ftrace_event_enable_disable(file, 0);
2146 * The do_for_each_event_file() is
2147 * a double loop. After finding the call for this
2148 * trace_array, we use break to jump to the next
2152 } while_for_each_event_file();
2154 if (call->event.funcs)
2155 __unregister_trace_event(&call->event);
2156 remove_event_from_tracers(call);
2157 list_del(&call->list);
2160 static int event_init(struct trace_event_call *call)
2165 name = trace_event_name(call);
2169 if (call->class->raw_init) {
2170 ret = call->class->raw_init(call);
2171 if (ret < 0 && ret != -ENOSYS)
2172 pr_warn("Could not initialize trace events/%s\n", name);
2179 __register_event(struct trace_event_call *call, struct module *mod)
2183 ret = event_init(call);
2187 list_add(&call->list, &ftrace_events);
2193 static char *enum_replace(char *ptr, struct trace_enum_map *map, int len)
2198 /* Find the length of the enum value as a string */
2199 elen = snprintf(ptr, 0, "%ld", map->enum_value);
2200 /* Make sure there's enough room to replace the string with the value */
2204 snprintf(ptr, elen + 1, "%ld", map->enum_value);
2206 /* Get the rest of the string of ptr */
2207 rlen = strlen(ptr + len);
2208 memmove(ptr + elen, ptr + len, rlen);
2209 /* Make sure we end the new string */
2210 ptr[elen + rlen] = 0;
2215 static void update_event_printk(struct trace_event_call *call,
2216 struct trace_enum_map *map)
2220 int len = strlen(map->enum_string);
2222 for (ptr = call->print_fmt; *ptr; ptr++) {
2236 if (isdigit(*ptr)) {
2240 /* Check for alpha chars like ULL */
2241 } while (isalnum(*ptr));
2245 * A number must have some kind of delimiter after
2246 * it, and we can ignore that too.
2250 if (isalpha(*ptr) || *ptr == '_') {
2251 if (strncmp(map->enum_string, ptr, len) == 0 &&
2252 !isalnum(ptr[len]) && ptr[len] != '_') {
2253 ptr = enum_replace(ptr, map, len);
2254 /* Hmm, enum string smaller than value */
2255 if (WARN_ON_ONCE(!ptr))
2258 * No need to decrement here, as enum_replace()
2259 * returns the pointer to the character passed
2260 * the enum, and two enums can not be placed
2261 * back to back without something in between.
2262 * We can skip that something in between.
2269 } while (isalnum(*ptr) || *ptr == '_');
2273 * If what comes after this variable is a '.' or
2274 * '->' then we can continue to ignore that string.
2276 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2277 ptr += *ptr == '.' ? 1 : 2;
2283 * Once again, we can skip the delimiter that came
2291 void trace_event_enum_update(struct trace_enum_map **map, int len)
2293 struct trace_event_call *call, *p;
2294 const char *last_system = NULL;
2298 down_write(&trace_event_sem);
2299 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2300 /* events are usually grouped together with systems */
2301 if (!last_system || call->class->system != last_system) {
2303 last_system = call->class->system;
2306 for (i = last_i; i < len; i++) {
2307 if (call->class->system == map[i]->system) {
2308 /* Save the first system if need be */
2311 update_event_printk(call, map[i]);
2315 up_write(&trace_event_sem);
2318 static struct trace_event_file *
2319 trace_create_new_event(struct trace_event_call *call,
2320 struct trace_array *tr)
2322 struct trace_event_file *file;
2324 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2328 file->event_call = call;
2330 atomic_set(&file->sm_ref, 0);
2331 atomic_set(&file->tm_ref, 0);
2332 INIT_LIST_HEAD(&file->triggers);
2333 list_add(&file->list, &tr->events);
2338 /* Add an event to a trace directory */
2340 __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2342 struct trace_event_file *file;
2344 file = trace_create_new_event(call, tr);
2348 return event_create_dir(tr->event_dir, file);
2352 * Just create a decriptor for early init. A descriptor is required
2353 * for enabling events at boot. We want to enable events before
2354 * the filesystem is initialized.
2357 __trace_early_add_new_event(struct trace_event_call *call,
2358 struct trace_array *tr)
2360 struct trace_event_file *file;
2362 file = trace_create_new_event(call, tr);
2369 struct ftrace_module_file_ops;
2370 static void __add_event_to_tracers(struct trace_event_call *call);
2372 /* Add an additional event_call dynamically */
2373 int trace_add_event_call(struct trace_event_call *call)
2376 mutex_lock(&trace_types_lock);
2377 mutex_lock(&event_mutex);
2379 ret = __register_event(call, NULL);
2381 __add_event_to_tracers(call);
2383 mutex_unlock(&event_mutex);
2384 mutex_unlock(&trace_types_lock);
2389 * Must be called under locking of trace_types_lock, event_mutex and
2392 static void __trace_remove_event_call(struct trace_event_call *call)
2395 trace_destroy_fields(call);
2396 free_event_filter(call->filter);
2397 call->filter = NULL;
2400 static int probe_remove_event_call(struct trace_event_call *call)
2402 struct trace_array *tr;
2403 struct trace_event_file *file;
2405 #ifdef CONFIG_PERF_EVENTS
2406 if (call->perf_refcount)
2409 do_for_each_event_file(tr, file) {
2410 if (file->event_call != call)
2413 * We can't rely on ftrace_event_enable_disable(enable => 0)
2414 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2415 * TRACE_REG_UNREGISTER.
2417 if (file->flags & EVENT_FILE_FL_ENABLED)
2420 * The do_for_each_event_file_safe() is
2421 * a double loop. After finding the call for this
2422 * trace_array, we use break to jump to the next
2426 } while_for_each_event_file();
2428 __trace_remove_event_call(call);
2433 /* Remove an event_call */
2434 int trace_remove_event_call(struct trace_event_call *call)
2438 mutex_lock(&trace_types_lock);
2439 mutex_lock(&event_mutex);
2440 down_write(&trace_event_sem);
2441 ret = probe_remove_event_call(call);
2442 up_write(&trace_event_sem);
2443 mutex_unlock(&event_mutex);
2444 mutex_unlock(&trace_types_lock);
2449 #define for_each_event(event, start, end) \
2450 for (event = start; \
2451 (unsigned long)event < (unsigned long)end; \
2454 #ifdef CONFIG_MODULES
2456 static void trace_module_add_events(struct module *mod)
2458 struct trace_event_call **call, **start, **end;
2460 if (!mod->num_trace_events)
2463 /* Don't add infrastructure for mods without tracepoints */
2464 if (trace_module_has_bad_taint(mod)) {
2465 pr_err("%s: module has bad taint, not creating trace events\n",
2470 start = mod->trace_events;
2471 end = mod->trace_events + mod->num_trace_events;
2473 for_each_event(call, start, end) {
2474 __register_event(*call, mod);
2475 __add_event_to_tracers(*call);
2479 static void trace_module_remove_events(struct module *mod)
2481 struct trace_event_call *call, *p;
2482 bool clear_trace = false;
2484 down_write(&trace_event_sem);
2485 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2486 if (call->mod == mod) {
2487 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
2489 __trace_remove_event_call(call);
2492 up_write(&trace_event_sem);
2495 * It is safest to reset the ring buffer if the module being unloaded
2496 * registered any events that were used. The only worry is if
2497 * a new module gets loaded, and takes on the same id as the events
2498 * of this module. When printing out the buffer, traced events left
2499 * over from this module may be passed to the new module events and
2500 * unexpected results may occur.
2503 tracing_reset_all_online_cpus();
2506 static int trace_module_notify(struct notifier_block *self,
2507 unsigned long val, void *data)
2509 struct module *mod = data;
2511 mutex_lock(&trace_types_lock);
2512 mutex_lock(&event_mutex);
2514 case MODULE_STATE_COMING:
2515 trace_module_add_events(mod);
2517 case MODULE_STATE_GOING:
2518 trace_module_remove_events(mod);
2521 mutex_unlock(&event_mutex);
2522 mutex_unlock(&trace_types_lock);
2527 static struct notifier_block trace_module_nb = {
2528 .notifier_call = trace_module_notify,
2529 .priority = 1, /* higher than trace.c module notify */
2531 #endif /* CONFIG_MODULES */
2533 /* Create a new event directory structure for a trace directory. */
2535 __trace_add_event_dirs(struct trace_array *tr)
2537 struct trace_event_call *call;
2540 list_for_each_entry(call, &ftrace_events, list) {
2541 ret = __trace_add_new_event(call, tr);
2543 pr_warn("Could not create directory for event %s\n",
2544 trace_event_name(call));
2548 struct trace_event_file *
2549 find_event_file(struct trace_array *tr, const char *system, const char *event)
2551 struct trace_event_file *file;
2552 struct trace_event_call *call;
2555 list_for_each_entry(file, &tr->events, list) {
2557 call = file->event_call;
2558 name = trace_event_name(call);
2560 if (!name || !call->class || !call->class->reg)
2563 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2566 if (strcmp(event, name) == 0 &&
2567 strcmp(system, call->class->system) == 0)
2573 #ifdef CONFIG_DYNAMIC_FTRACE
2576 #define ENABLE_EVENT_STR "enable_event"
2577 #define DISABLE_EVENT_STR "disable_event"
2579 struct event_probe_data {
2580 struct trace_event_file *file;
2581 unsigned long count;
2587 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2589 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2590 struct event_probe_data *data = *pdata;
2596 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2598 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2602 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2604 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2605 struct event_probe_data *data = *pdata;
2613 /* Skip if the event is in a state we want to switch to */
2614 if (data->enable == !(data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
2617 if (data->count != -1)
2620 event_enable_probe(ip, parent_ip, _data);
2624 event_enable_print(struct seq_file *m, unsigned long ip,
2625 struct ftrace_probe_ops *ops, void *_data)
2627 struct event_probe_data *data = _data;
2629 seq_printf(m, "%ps:", (void *)ip);
2631 seq_printf(m, "%s:%s:%s",
2632 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2633 data->file->event_call->class->system,
2634 trace_event_name(data->file->event_call));
2636 if (data->count == -1)
2637 seq_puts(m, ":unlimited\n");
2639 seq_printf(m, ":count=%ld\n", data->count);
2645 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
2648 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2649 struct event_probe_data *data = *pdata;
2656 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
2659 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2660 struct event_probe_data *data = *pdata;
2662 if (WARN_ON_ONCE(data->ref <= 0))
2667 /* Remove the SOFT_MODE flag */
2668 __ftrace_event_enable_disable(data->file, 0, 1);
2669 module_put(data->file->event_call->mod);
2675 static struct ftrace_probe_ops event_enable_probe_ops = {
2676 .func = event_enable_probe,
2677 .print = event_enable_print,
2678 .init = event_enable_init,
2679 .free = event_enable_free,
2682 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2683 .func = event_enable_count_probe,
2684 .print = event_enable_print,
2685 .init = event_enable_init,
2686 .free = event_enable_free,
2689 static struct ftrace_probe_ops event_disable_probe_ops = {
2690 .func = event_enable_probe,
2691 .print = event_enable_print,
2692 .init = event_enable_init,
2693 .free = event_enable_free,
2696 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2697 .func = event_enable_count_probe,
2698 .print = event_enable_print,
2699 .init = event_enable_init,
2700 .free = event_enable_free,
2704 event_enable_func(struct ftrace_hash *hash,
2705 char *glob, char *cmd, char *param, int enabled)
2707 struct trace_array *tr = top_trace_array();
2708 struct trace_event_file *file;
2709 struct ftrace_probe_ops *ops;
2710 struct event_probe_data *data;
2720 /* hash funcs only work with set_ftrace_filter */
2721 if (!enabled || !param)
2724 system = strsep(¶m, ":");
2728 event = strsep(¶m, ":");
2730 mutex_lock(&event_mutex);
2733 file = find_event_file(tr, system, event);
2737 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2740 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2742 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2744 if (glob[0] == '!') {
2745 unregister_ftrace_function_probe_func(glob+1, ops);
2751 data = kzalloc(sizeof(*data), GFP_KERNEL);
2755 data->enable = enable;
2762 number = strsep(¶m, ":");
2765 if (!strlen(number))
2769 * We use the callback data field (which is a pointer)
2772 ret = kstrtoul(number, 0, &data->count);
2777 /* Don't let event modules unload while probe registered */
2778 ret = try_module_get(file->event_call->mod);
2784 ret = __ftrace_event_enable_disable(file, 1, 1);
2787 ret = register_ftrace_function_probe(glob, ops, data);
2789 * The above returns on success the # of functions enabled,
2790 * but if it didn't find any functions it returns zero.
2791 * Consider no functions a failure too.
2798 /* Just return zero, not the number of enabled functions */
2801 mutex_unlock(&event_mutex);
2805 __ftrace_event_enable_disable(file, 0, 1);
2807 module_put(file->event_call->mod);
2813 static struct ftrace_func_command event_enable_cmd = {
2814 .name = ENABLE_EVENT_STR,
2815 .func = event_enable_func,
2818 static struct ftrace_func_command event_disable_cmd = {
2819 .name = DISABLE_EVENT_STR,
2820 .func = event_enable_func,
2823 static __init int register_event_cmds(void)
2827 ret = register_ftrace_command(&event_enable_cmd);
2828 if (WARN_ON(ret < 0))
2830 ret = register_ftrace_command(&event_disable_cmd);
2831 if (WARN_ON(ret < 0))
2832 unregister_ftrace_command(&event_enable_cmd);
2836 static inline int register_event_cmds(void) { return 0; }
2837 #endif /* CONFIG_DYNAMIC_FTRACE */
2840 * The top level array has already had its trace_event_file
2841 * descriptors created in order to allow for early events to
2842 * be recorded. This function is called after the tracefs has been
2843 * initialized, and we now have to create the files associated
2847 __trace_early_add_event_dirs(struct trace_array *tr)
2849 struct trace_event_file *file;
2853 list_for_each_entry(file, &tr->events, list) {
2854 ret = event_create_dir(tr->event_dir, file);
2856 pr_warn("Could not create directory for event %s\n",
2857 trace_event_name(file->event_call));
2862 * For early boot up, the top trace array requires to have
2863 * a list of events that can be enabled. This must be done before
2864 * the filesystem is set up in order to allow events to be traced
2868 __trace_early_add_events(struct trace_array *tr)
2870 struct trace_event_call *call;
2873 list_for_each_entry(call, &ftrace_events, list) {
2874 /* Early boot up should not have any modules loaded */
2875 if (WARN_ON_ONCE(call->mod))
2878 ret = __trace_early_add_new_event(call, tr);
2880 pr_warn("Could not create early event %s\n",
2881 trace_event_name(call));
2885 /* Remove the event directory structure for a trace directory. */
2887 __trace_remove_event_dirs(struct trace_array *tr)
2889 struct trace_event_file *file, *next;
2891 list_for_each_entry_safe(file, next, &tr->events, list)
2892 remove_event_file_dir(file);
2895 static void __add_event_to_tracers(struct trace_event_call *call)
2897 struct trace_array *tr;
2899 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2900 __trace_add_new_event(call, tr);
2903 extern struct trace_event_call *__start_ftrace_events[];
2904 extern struct trace_event_call *__stop_ftrace_events[];
2906 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2908 static __init int setup_trace_event(char *str)
2910 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2911 ring_buffer_expanded = true;
2912 tracing_selftest_disabled = true;
2916 __setup("trace_event=", setup_trace_event);
2918 /* Expects to have event_mutex held when called */
2920 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2922 struct dentry *d_events;
2923 struct dentry *entry;
2925 entry = tracefs_create_file("set_event", 0644, parent,
2926 tr, &ftrace_set_event_fops);
2928 pr_warn("Could not create tracefs 'set_event' entry\n");
2932 d_events = tracefs_create_dir("events", parent);
2934 pr_warn("Could not create tracefs 'events' directory\n");
2938 entry = tracefs_create_file("set_event_pid", 0644, parent,
2939 tr, &ftrace_set_event_pid_fops);
2941 /* ring buffer internal formats */
2942 trace_create_file("header_page", 0444, d_events,
2943 ring_buffer_print_page_header,
2944 &ftrace_show_header_fops);
2946 trace_create_file("header_event", 0444, d_events,
2947 ring_buffer_print_entry_header,
2948 &ftrace_show_header_fops);
2950 trace_create_file("enable", 0644, d_events,
2951 tr, &ftrace_tr_enable_fops);
2953 tr->event_dir = d_events;
2959 * event_trace_add_tracer - add a instance of a trace_array to events
2960 * @parent: The parent dentry to place the files/directories for events in
2961 * @tr: The trace array associated with these events
2963 * When a new instance is created, it needs to set up its events
2964 * directory, as well as other files associated with events. It also
2965 * creates the event hierachry in the @parent/events directory.
2967 * Returns 0 on success.
2969 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2973 mutex_lock(&event_mutex);
2975 ret = create_event_toplevel_files(parent, tr);
2979 down_write(&trace_event_sem);
2980 __trace_add_event_dirs(tr);
2981 up_write(&trace_event_sem);
2984 mutex_unlock(&event_mutex);
2990 * The top trace array already had its file descriptors created.
2991 * Now the files themselves need to be created.
2994 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2998 mutex_lock(&event_mutex);
3000 ret = create_event_toplevel_files(parent, tr);
3004 down_write(&trace_event_sem);
3005 __trace_early_add_event_dirs(tr);
3006 up_write(&trace_event_sem);
3009 mutex_unlock(&event_mutex);
3014 int event_trace_del_tracer(struct trace_array *tr)
3016 mutex_lock(&event_mutex);
3018 /* Disable any event triggers and associated soft-disabled events */
3019 clear_event_triggers(tr);
3021 /* Clear the pid list */
3022 __ftrace_clear_event_pids(tr);
3024 /* Disable any running events */
3025 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3027 /* Access to events are within rcu_read_lock_sched() */
3028 synchronize_sched();
3030 down_write(&trace_event_sem);
3031 __trace_remove_event_dirs(tr);
3032 tracefs_remove_recursive(tr->event_dir);
3033 up_write(&trace_event_sem);
3035 tr->event_dir = NULL;
3037 mutex_unlock(&event_mutex);
3042 static __init int event_trace_memsetup(void)
3044 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3045 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3050 early_enable_events(struct trace_array *tr, bool disable_first)
3052 char *buf = bootup_event_buf;
3057 token = strsep(&buf, ",");
3063 /* Restarting syscalls requires that we stop them first */
3065 ftrace_set_clr_event(tr, token, 0);
3067 ret = ftrace_set_clr_event(tr, token, 1);
3069 pr_warn("Failed to enable trace event: %s\n", token);
3072 /* Put back the comma to allow this to be called again */
3078 static __init int event_trace_enable(void)
3080 struct trace_array *tr = top_trace_array();
3081 struct trace_event_call **iter, *call;
3087 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3090 ret = event_init(call);
3092 list_add(&call->list, &ftrace_events);
3096 * We need the top trace array to have a working set of trace
3097 * points at early init, before the debug files and directories
3098 * are created. Create the file entries now, and attach them
3099 * to the actual file dentries later.
3101 __trace_early_add_events(tr);
3103 early_enable_events(tr, false);
3105 trace_printk_start_comm();
3107 register_event_cmds();
3109 register_trigger_cmds();
3115 * event_trace_enable() is called from trace_event_init() first to
3116 * initialize events and perhaps start any events that are on the
3117 * command line. Unfortunately, there are some events that will not
3118 * start this early, like the system call tracepoints that need
3119 * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
3120 * is called before pid 1 starts, and this flag is never set, making
3121 * the syscall tracepoint never get reached, but the event is enabled
3122 * regardless (and not doing anything).
3124 static __init int event_trace_enable_again(void)
3126 struct trace_array *tr;
3128 tr = top_trace_array();
3132 early_enable_events(tr, true);
3137 early_initcall(event_trace_enable_again);
3139 static __init int event_trace_init(void)
3141 struct trace_array *tr;
3142 struct dentry *d_tracer;
3143 struct dentry *entry;
3146 tr = top_trace_array();
3150 d_tracer = tracing_init_dentry();
3151 if (IS_ERR(d_tracer))
3154 entry = tracefs_create_file("available_events", 0444, d_tracer,
3155 tr, &ftrace_avail_fops);
3157 pr_warn("Could not create tracefs 'available_events' entry\n");
3159 if (trace_define_generic_fields())
3160 pr_warn("tracing: Failed to allocated generic fields");
3162 if (trace_define_common_fields())
3163 pr_warn("tracing: Failed to allocate common fields");
3165 ret = early_event_add_tracer(d_tracer, tr);
3169 #ifdef CONFIG_MODULES
3170 ret = register_module_notifier(&trace_module_nb);
3172 pr_warn("Failed to register trace events module notifier\n");
3177 void __init trace_event_init(void)
3179 event_trace_memsetup();
3180 init_ftrace_syscalls();
3181 event_trace_enable();
3184 fs_initcall(event_trace_init);
3186 #ifdef CONFIG_FTRACE_STARTUP_TEST
3188 static DEFINE_SPINLOCK(test_spinlock);
3189 static DEFINE_SPINLOCK(test_spinlock_irq);
3190 static DEFINE_MUTEX(test_mutex);
3192 static __init void test_work(struct work_struct *dummy)
3194 spin_lock(&test_spinlock);
3195 spin_lock_irq(&test_spinlock_irq);
3197 spin_unlock_irq(&test_spinlock_irq);
3198 spin_unlock(&test_spinlock);
3200 mutex_lock(&test_mutex);
3202 mutex_unlock(&test_mutex);
3205 static __init int event_test_thread(void *unused)
3209 test_malloc = kmalloc(1234, GFP_KERNEL);
3211 pr_info("failed to kmalloc\n");
3213 schedule_on_each_cpu(test_work);
3217 set_current_state(TASK_INTERRUPTIBLE);
3218 while (!kthread_should_stop()) {
3220 set_current_state(TASK_INTERRUPTIBLE);
3222 __set_current_state(TASK_RUNNING);
3228 * Do various things that may trigger events.
3230 static __init void event_test_stuff(void)
3232 struct task_struct *test_thread;
3234 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3236 kthread_stop(test_thread);
3240 * For every trace event defined, we will test each trace point separately,
3241 * and then by groups, and finally all trace points.
3243 static __init void event_trace_self_tests(void)
3245 struct trace_subsystem_dir *dir;
3246 struct trace_event_file *file;
3247 struct trace_event_call *call;
3248 struct event_subsystem *system;
3249 struct trace_array *tr;
3252 tr = top_trace_array();
3256 pr_info("Running tests on trace events:\n");
3258 list_for_each_entry(file, &tr->events, list) {
3260 call = file->event_call;
3262 /* Only test those that have a probe */
3263 if (!call->class || !call->class->probe)
3267 * Testing syscall events here is pretty useless, but
3268 * we still do it if configured. But this is time consuming.
3269 * What we really need is a user thread to perform the
3270 * syscalls as we test.
3272 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3273 if (call->class->system &&
3274 strcmp(call->class->system, "syscalls") == 0)
3278 pr_info("Testing event %s: ", trace_event_name(call));
3281 * If an event is already enabled, someone is using
3282 * it and the self test should not be on.
3284 if (file->flags & EVENT_FILE_FL_ENABLED) {
3285 pr_warn("Enabled event during self test!\n");
3290 ftrace_event_enable_disable(file, 1);
3292 ftrace_event_enable_disable(file, 0);
3297 /* Now test at the sub system level */
3299 pr_info("Running tests on trace event systems:\n");
3301 list_for_each_entry(dir, &tr->systems, list) {
3303 system = dir->subsystem;
3305 /* the ftrace system is special, skip it */
3306 if (strcmp(system->name, "ftrace") == 0)
3309 pr_info("Testing event system %s: ", system->name);
3311 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3312 if (WARN_ON_ONCE(ret)) {
3313 pr_warn("error enabling system %s\n",
3320 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3321 if (WARN_ON_ONCE(ret)) {
3322 pr_warn("error disabling system %s\n",
3330 /* Test with all events enabled */
3332 pr_info("Running tests on all trace events:\n");
3333 pr_info("Testing all events: ");
3335 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3336 if (WARN_ON_ONCE(ret)) {
3337 pr_warn("error enabling all events\n");
3344 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3345 if (WARN_ON_ONCE(ret)) {
3346 pr_warn("error disabling all events\n");
3353 #ifdef CONFIG_FUNCTION_TRACER
3355 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3357 static struct trace_array *event_tr;
3360 function_test_events_call(unsigned long ip, unsigned long parent_ip,
3361 struct ftrace_ops *op, struct pt_regs *pt_regs)
3363 struct ring_buffer_event *event;
3364 struct ring_buffer *buffer;
3365 struct ftrace_entry *entry;
3366 unsigned long flags;
3371 pc = preempt_count();
3372 preempt_disable_notrace();
3373 cpu = raw_smp_processor_id();
3374 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3379 local_save_flags(flags);
3381 event = trace_current_buffer_lock_reserve(&buffer,
3382 TRACE_FN, sizeof(*entry),
3386 entry = ring_buffer_event_data(event);
3388 entry->parent_ip = parent_ip;
3390 trace_buffer_unlock_commit(event_tr, buffer, event, flags, pc);
3393 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3394 preempt_enable_notrace();
3397 static struct ftrace_ops trace_ops __initdata =
3399 .func = function_test_events_call,
3400 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
3403 static __init void event_trace_self_test_with_function(void)
3406 event_tr = top_trace_array();
3407 if (WARN_ON(!event_tr))
3409 ret = register_ftrace_function(&trace_ops);
3410 if (WARN_ON(ret < 0)) {
3411 pr_info("Failed to enable function tracer for event tests\n");
3414 pr_info("Running tests again, along with the function tracer\n");
3415 event_trace_self_tests();
3416 unregister_ftrace_function(&trace_ops);
3419 static __init void event_trace_self_test_with_function(void)
3424 static __init int event_trace_self_tests_init(void)
3426 if (!tracing_selftest_disabled) {
3427 event_trace_self_tests();
3428 event_trace_self_test_with_function();
3434 late_initcall(event_trace_self_tests_init);