1 // SPDX-License-Identifier: GPL-2.0
5 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
7 * - Added format output of fields of the trace point.
8 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
12 #define pr_fmt(fmt) fmt
14 #include <linux/workqueue.h>
15 #include <linux/security.h>
16 #include <linux/spinlock.h>
17 #include <linux/kthread.h>
18 #include <linux/tracefs.h>
19 #include <linux/uaccess.h>
20 #include <linux/module.h>
21 #include <linux/ctype.h>
22 #include <linux/sort.h>
23 #include <linux/slab.h>
24 #include <linux/delay.h>
26 #include <trace/events/sched.h>
27 #include <trace/syscall.h>
29 #include <asm/setup.h>
31 #include "trace_output.h"
34 #define TRACE_SYSTEM "TRACE_SYSTEM"
36 DEFINE_MUTEX(event_mutex);
38 LIST_HEAD(ftrace_events);
39 static LIST_HEAD(ftrace_generic_fields);
40 static LIST_HEAD(ftrace_common_fields);
42 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
44 static struct kmem_cache *field_cachep;
45 static struct kmem_cache *file_cachep;
47 static inline int system_refcount(struct event_subsystem *system)
49 return system->ref_count;
52 static int system_refcount_inc(struct event_subsystem *system)
54 return system->ref_count++;
57 static int system_refcount_dec(struct event_subsystem *system)
59 return --system->ref_count;
62 /* Double loops, do not use break, only goto's work */
63 #define do_for_each_event_file(tr, file) \
64 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
65 list_for_each_entry(file, &tr->events, list)
67 #define do_for_each_event_file_safe(tr, file) \
68 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
69 struct trace_event_file *___n; \
70 list_for_each_entry_safe(file, ___n, &tr->events, list)
72 #define while_for_each_event_file() \
75 static struct ftrace_event_field *
76 __find_event_field(struct list_head *head, char *name)
78 struct ftrace_event_field *field;
80 list_for_each_entry(field, head, link) {
81 if (!strcmp(field->name, name))
88 struct ftrace_event_field *
89 trace_find_event_field(struct trace_event_call *call, char *name)
91 struct ftrace_event_field *field;
92 struct list_head *head;
94 head = trace_get_fields(call);
95 field = __find_event_field(head, name);
99 field = __find_event_field(&ftrace_generic_fields, name);
103 return __find_event_field(&ftrace_common_fields, name);
106 static int __trace_define_field(struct list_head *head, const char *type,
107 const char *name, int offset, int size,
108 int is_signed, int filter_type)
110 struct ftrace_event_field *field;
112 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
119 if (filter_type == FILTER_OTHER)
120 field->filter_type = filter_assign_type(type);
122 field->filter_type = filter_type;
124 field->offset = offset;
126 field->is_signed = is_signed;
128 list_add(&field->link, head);
133 int trace_define_field(struct trace_event_call *call, const char *type,
134 const char *name, int offset, int size, int is_signed,
137 struct list_head *head;
139 if (WARN_ON(!call->class))
142 head = trace_get_fields(call);
143 return __trace_define_field(head, type, name, offset, size,
144 is_signed, filter_type);
146 EXPORT_SYMBOL_GPL(trace_define_field);
148 #define __generic_field(type, item, filter_type) \
149 ret = __trace_define_field(&ftrace_generic_fields, #type, \
150 #item, 0, 0, is_signed_type(type), \
155 #define __common_field(type, item) \
156 ret = __trace_define_field(&ftrace_common_fields, #type, \
158 offsetof(typeof(ent), item), \
160 is_signed_type(type), FILTER_OTHER); \
164 static int trace_define_generic_fields(void)
168 __generic_field(int, CPU, FILTER_CPU);
169 __generic_field(int, cpu, FILTER_CPU);
170 __generic_field(char *, COMM, FILTER_COMM);
171 __generic_field(char *, comm, FILTER_COMM);
176 static int trace_define_common_fields(void)
179 struct trace_entry ent;
181 __common_field(unsigned short, type);
182 __common_field(unsigned char, flags);
183 __common_field(unsigned char, preempt_count);
184 __common_field(int, pid);
189 static void trace_destroy_fields(struct trace_event_call *call)
191 struct ftrace_event_field *field, *next;
192 struct list_head *head;
194 head = trace_get_fields(call);
195 list_for_each_entry_safe(field, next, head, link) {
196 list_del(&field->link);
197 kmem_cache_free(field_cachep, field);
202 * run-time version of trace_event_get_offsets_<call>() that returns the last
203 * accessible offset of trace fields excluding __dynamic_array bytes
205 int trace_event_get_offsets(struct trace_event_call *call)
207 struct ftrace_event_field *tail;
208 struct list_head *head;
210 head = trace_get_fields(call);
212 * head->next points to the last field with the largest offset,
213 * since it was added last by trace_define_field()
215 tail = list_first_entry(head, struct ftrace_event_field, link);
216 return tail->offset + tail->size;
219 int trace_event_raw_init(struct trace_event_call *call)
223 id = register_trace_event(&call->event);
229 EXPORT_SYMBOL_GPL(trace_event_raw_init);
231 bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
233 struct trace_array *tr = trace_file->tr;
234 struct trace_array_cpu *data;
235 struct trace_pid_list *no_pid_list;
236 struct trace_pid_list *pid_list;
238 pid_list = rcu_dereference_raw(tr->filtered_pids);
239 no_pid_list = rcu_dereference_raw(tr->filtered_no_pids);
241 if (!pid_list && !no_pid_list)
244 data = this_cpu_ptr(tr->array_buffer.data);
246 return data->ignore_pid;
248 EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
250 void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
251 struct trace_event_file *trace_file,
254 struct trace_event_call *event_call = trace_file->event_call;
256 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
257 trace_event_ignore_this_pid(trace_file))
260 local_save_flags(fbuffer->flags);
261 fbuffer->pc = preempt_count();
263 * If CONFIG_PREEMPTION is enabled, then the tracepoint itself disables
264 * preemption (adding one to the preempt_count). Since we are
265 * interested in the preempt_count at the time the tracepoint was
266 * hit, we need to subtract one to offset the increment.
268 if (IS_ENABLED(CONFIG_PREEMPTION))
270 fbuffer->trace_file = trace_file;
273 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
274 event_call->event.type, len,
275 fbuffer->flags, fbuffer->pc);
279 fbuffer->regs = NULL;
280 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
281 return fbuffer->entry;
283 EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
285 int trace_event_reg(struct trace_event_call *call,
286 enum trace_reg type, void *data)
288 struct trace_event_file *file = data;
290 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
292 case TRACE_REG_REGISTER:
293 return tracepoint_probe_register(call->tp,
296 case TRACE_REG_UNREGISTER:
297 tracepoint_probe_unregister(call->tp,
302 #ifdef CONFIG_PERF_EVENTS
303 case TRACE_REG_PERF_REGISTER:
304 return tracepoint_probe_register(call->tp,
305 call->class->perf_probe,
307 case TRACE_REG_PERF_UNREGISTER:
308 tracepoint_probe_unregister(call->tp,
309 call->class->perf_probe,
312 case TRACE_REG_PERF_OPEN:
313 case TRACE_REG_PERF_CLOSE:
314 case TRACE_REG_PERF_ADD:
315 case TRACE_REG_PERF_DEL:
321 EXPORT_SYMBOL_GPL(trace_event_reg);
323 void trace_event_enable_cmd_record(bool enable)
325 struct trace_event_file *file;
326 struct trace_array *tr;
328 lockdep_assert_held(&event_mutex);
330 do_for_each_event_file(tr, file) {
332 if (!(file->flags & EVENT_FILE_FL_ENABLED))
336 tracing_start_cmdline_record();
337 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
339 tracing_stop_cmdline_record();
340 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
342 } while_for_each_event_file();
345 void trace_event_enable_tgid_record(bool enable)
347 struct trace_event_file *file;
348 struct trace_array *tr;
350 lockdep_assert_held(&event_mutex);
352 do_for_each_event_file(tr, file) {
353 if (!(file->flags & EVENT_FILE_FL_ENABLED))
357 tracing_start_tgid_record();
358 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
360 tracing_stop_tgid_record();
361 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
364 } while_for_each_event_file();
367 static int __ftrace_event_enable_disable(struct trace_event_file *file,
368 int enable, int soft_disable)
370 struct trace_event_call *call = file->event_call;
371 struct trace_array *tr = file->tr;
372 unsigned long file_flags = file->flags;
379 * When soft_disable is set and enable is cleared, the sm_ref
380 * reference counter is decremented. If it reaches 0, we want
381 * to clear the SOFT_DISABLED flag but leave the event in the
382 * state that it was. That is, if the event was enabled and
383 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
384 * is set we do not want the event to be enabled before we
387 * When soft_disable is not set but the SOFT_MODE flag is,
388 * we do nothing. Do not disable the tracepoint, otherwise
389 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
392 if (atomic_dec_return(&file->sm_ref) > 0)
394 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
395 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
397 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
399 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
400 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
401 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
402 tracing_stop_cmdline_record();
403 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
406 if (file->flags & EVENT_FILE_FL_RECORDED_TGID) {
407 tracing_stop_tgid_record();
408 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
411 call->class->reg(call, TRACE_REG_UNREGISTER, file);
413 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
414 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
415 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
417 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
421 * When soft_disable is set and enable is set, we want to
422 * register the tracepoint for the event, but leave the event
423 * as is. That means, if the event was already enabled, we do
424 * nothing (but set SOFT_MODE). If the event is disabled, we
425 * set SOFT_DISABLED before enabling the event tracepoint, so
426 * it still seems to be disabled.
429 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
431 if (atomic_inc_return(&file->sm_ref) > 1)
433 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
436 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
437 bool cmd = false, tgid = false;
439 /* Keep the event disabled, when going to SOFT_MODE. */
441 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
443 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
445 tracing_start_cmdline_record();
446 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
449 if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
451 tracing_start_tgid_record();
452 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
455 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
458 tracing_stop_cmdline_record();
460 tracing_stop_tgid_record();
461 pr_info("event trace: Could not enable event "
462 "%s\n", trace_event_name(call));
465 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
467 /* WAS_ENABLED gets set but never cleared. */
468 set_bit(EVENT_FILE_FL_WAS_ENABLED_BIT, &file->flags);
473 /* Enable or disable use of trace_buffered_event */
474 if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) !=
475 (file->flags & EVENT_FILE_FL_SOFT_DISABLED)) {
476 if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
477 trace_buffered_event_enable();
479 trace_buffered_event_disable();
485 int trace_event_enable_disable(struct trace_event_file *file,
486 int enable, int soft_disable)
488 return __ftrace_event_enable_disable(file, enable, soft_disable);
491 static int ftrace_event_enable_disable(struct trace_event_file *file,
494 return __ftrace_event_enable_disable(file, enable, 0);
497 static void ftrace_clear_events(struct trace_array *tr)
499 struct trace_event_file *file;
501 mutex_lock(&event_mutex);
502 list_for_each_entry(file, &tr->events, list) {
503 ftrace_event_enable_disable(file, 0);
505 mutex_unlock(&event_mutex);
509 event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
511 struct trace_pid_list *pid_list;
512 struct trace_array *tr = data;
514 pid_list = rcu_dereference_raw(tr->filtered_pids);
515 trace_filter_add_remove_task(pid_list, NULL, task);
517 pid_list = rcu_dereference_raw(tr->filtered_no_pids);
518 trace_filter_add_remove_task(pid_list, NULL, task);
522 event_filter_pid_sched_process_fork(void *data,
523 struct task_struct *self,
524 struct task_struct *task)
526 struct trace_pid_list *pid_list;
527 struct trace_array *tr = data;
529 pid_list = rcu_dereference_sched(tr->filtered_pids);
530 trace_filter_add_remove_task(pid_list, self, task);
532 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
533 trace_filter_add_remove_task(pid_list, self, task);
536 void trace_event_follow_fork(struct trace_array *tr, bool enable)
539 register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
541 register_trace_prio_sched_process_exit(event_filter_pid_sched_process_exit,
544 unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
546 unregister_trace_sched_process_exit(event_filter_pid_sched_process_exit,
552 event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
553 struct task_struct *prev, struct task_struct *next)
555 struct trace_array *tr = data;
556 struct trace_pid_list *no_pid_list;
557 struct trace_pid_list *pid_list;
560 pid_list = rcu_dereference_sched(tr->filtered_pids);
561 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
564 * Sched switch is funny, as we only want to ignore it
565 * in the notrace case if both prev and next should be ignored.
567 ret = trace_ignore_this_task(NULL, no_pid_list, prev) &&
568 trace_ignore_this_task(NULL, no_pid_list, next);
570 this_cpu_write(tr->array_buffer.data->ignore_pid, ret ||
571 (trace_ignore_this_task(pid_list, NULL, prev) &&
572 trace_ignore_this_task(pid_list, NULL, next)));
576 event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
577 struct task_struct *prev, struct task_struct *next)
579 struct trace_array *tr = data;
580 struct trace_pid_list *no_pid_list;
581 struct trace_pid_list *pid_list;
583 pid_list = rcu_dereference_sched(tr->filtered_pids);
584 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
586 this_cpu_write(tr->array_buffer.data->ignore_pid,
587 trace_ignore_this_task(pid_list, no_pid_list, next));
591 event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
593 struct trace_array *tr = data;
594 struct trace_pid_list *no_pid_list;
595 struct trace_pid_list *pid_list;
597 /* Nothing to do if we are already tracing */
598 if (!this_cpu_read(tr->array_buffer.data->ignore_pid))
601 pid_list = rcu_dereference_sched(tr->filtered_pids);
602 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
604 this_cpu_write(tr->array_buffer.data->ignore_pid,
605 trace_ignore_this_task(pid_list, no_pid_list, task));
609 event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
611 struct trace_array *tr = data;
612 struct trace_pid_list *no_pid_list;
613 struct trace_pid_list *pid_list;
615 /* Nothing to do if we are not tracing */
616 if (this_cpu_read(tr->array_buffer.data->ignore_pid))
619 pid_list = rcu_dereference_sched(tr->filtered_pids);
620 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
622 /* Set tracing if current is enabled */
623 this_cpu_write(tr->array_buffer.data->ignore_pid,
624 trace_ignore_this_task(pid_list, no_pid_list, current));
627 static void unregister_pid_events(struct trace_array *tr)
629 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
630 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
632 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
633 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
635 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
636 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
638 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
639 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
642 static void __ftrace_clear_event_pids(struct trace_array *tr, int type)
644 struct trace_pid_list *pid_list;
645 struct trace_pid_list *no_pid_list;
646 struct trace_event_file *file;
649 pid_list = rcu_dereference_protected(tr->filtered_pids,
650 lockdep_is_held(&event_mutex));
651 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
652 lockdep_is_held(&event_mutex));
654 /* Make sure there's something to do */
655 if (!pid_type_enabled(type, pid_list, no_pid_list))
658 if (!still_need_pid_events(type, pid_list, no_pid_list)) {
659 unregister_pid_events(tr);
661 list_for_each_entry(file, &tr->events, list) {
662 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
665 for_each_possible_cpu(cpu)
666 per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false;
669 if (type & TRACE_PIDS)
670 rcu_assign_pointer(tr->filtered_pids, NULL);
672 if (type & TRACE_NO_PIDS)
673 rcu_assign_pointer(tr->filtered_no_pids, NULL);
675 /* Wait till all users are no longer using pid filtering */
676 tracepoint_synchronize_unregister();
678 if ((type & TRACE_PIDS) && pid_list)
679 trace_free_pid_list(pid_list);
681 if ((type & TRACE_NO_PIDS) && no_pid_list)
682 trace_free_pid_list(no_pid_list);
685 static void ftrace_clear_event_pids(struct trace_array *tr, int type)
687 mutex_lock(&event_mutex);
688 __ftrace_clear_event_pids(tr, type);
689 mutex_unlock(&event_mutex);
692 static void __put_system(struct event_subsystem *system)
694 struct event_filter *filter = system->filter;
696 WARN_ON_ONCE(system_refcount(system) == 0);
697 if (system_refcount_dec(system))
700 list_del(&system->list);
703 kfree(filter->filter_string);
706 kfree_const(system->name);
710 static void __get_system(struct event_subsystem *system)
712 WARN_ON_ONCE(system_refcount(system) == 0);
713 system_refcount_inc(system);
716 static void __get_system_dir(struct trace_subsystem_dir *dir)
718 WARN_ON_ONCE(dir->ref_count == 0);
720 __get_system(dir->subsystem);
723 static void __put_system_dir(struct trace_subsystem_dir *dir)
725 WARN_ON_ONCE(dir->ref_count == 0);
726 /* If the subsystem is about to be freed, the dir must be too */
727 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
729 __put_system(dir->subsystem);
730 if (!--dir->ref_count)
734 static void put_system(struct trace_subsystem_dir *dir)
736 mutex_lock(&event_mutex);
737 __put_system_dir(dir);
738 mutex_unlock(&event_mutex);
741 static void remove_subsystem(struct trace_subsystem_dir *dir)
746 if (!--dir->nr_events) {
747 tracefs_remove(dir->entry);
748 list_del(&dir->list);
749 __put_system_dir(dir);
753 static void remove_event_file_dir(struct trace_event_file *file)
755 struct dentry *dir = file->dir;
756 struct dentry *child;
759 spin_lock(&dir->d_lock); /* probably unneeded */
760 list_for_each_entry(child, &dir->d_subdirs, d_child) {
761 if (d_really_is_positive(child)) /* probably unneeded */
762 d_inode(child)->i_private = NULL;
764 spin_unlock(&dir->d_lock);
769 list_del(&file->list);
770 remove_subsystem(file->system);
771 free_event_filter(file->filter);
772 kmem_cache_free(file_cachep, file);
776 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
779 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
780 const char *sub, const char *event, int set)
782 struct trace_event_file *file;
783 struct trace_event_call *call;
788 list_for_each_entry(file, &tr->events, list) {
790 call = file->event_call;
791 name = trace_event_name(call);
793 if (!name || !call->class || !call->class->reg)
796 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
800 strcmp(match, name) != 0 &&
801 strcmp(match, call->class->system) != 0)
804 if (sub && strcmp(sub, call->class->system) != 0)
807 if (event && strcmp(event, name) != 0)
810 ret = ftrace_event_enable_disable(file, set);
813 * Save the first error and return that. Some events
814 * may still have been enabled, but let the user
815 * know that something went wrong.
826 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
827 const char *sub, const char *event, int set)
831 mutex_lock(&event_mutex);
832 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
833 mutex_unlock(&event_mutex);
838 int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
840 char *event = NULL, *sub = NULL, *match;
846 * The buf format can be <subsystem>:<event-name>
847 * *:<event-name> means any event by that name.
848 * :<event-name> is the same.
850 * <subsystem>:* means all events in that subsystem
851 * <subsystem>: means the same.
853 * <name> (no ':') means all events in a subsystem with
854 * the name <name> or any event that matches <name>
857 match = strsep(&buf, ":");
863 if (!strlen(sub) || strcmp(sub, "*") == 0)
865 if (!strlen(event) || strcmp(event, "*") == 0)
869 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
871 /* Put back the colon to allow this to be called again */
879 * trace_set_clr_event - enable or disable an event
880 * @system: system name to match (NULL for any system)
881 * @event: event name to match (NULL for all events, within system)
882 * @set: 1 to enable, 0 to disable
884 * This is a way for other parts of the kernel to enable or disable
887 * Returns 0 on success, -EINVAL if the parameters do not match any
890 int trace_set_clr_event(const char *system, const char *event, int set)
892 struct trace_array *tr = top_trace_array();
897 return __ftrace_set_clr_event(tr, NULL, system, event, set);
899 EXPORT_SYMBOL_GPL(trace_set_clr_event);
902 * trace_array_set_clr_event - enable or disable an event for a trace array.
903 * @tr: concerned trace array.
904 * @system: system name to match (NULL for any system)
905 * @event: event name to match (NULL for all events, within system)
906 * @enable: true to enable, false to disable
908 * This is a way for other parts of the kernel to enable or disable
911 * Returns 0 on success, -EINVAL if the parameters do not match any
914 int trace_array_set_clr_event(struct trace_array *tr, const char *system,
915 const char *event, bool enable)
922 set = (enable == true) ? 1 : 0;
923 return __ftrace_set_clr_event(tr, NULL, system, event, set);
925 EXPORT_SYMBOL_GPL(trace_array_set_clr_event);
927 /* 128 should be much more than enough */
928 #define EVENT_BUF_SIZE 127
931 ftrace_event_write(struct file *file, const char __user *ubuf,
932 size_t cnt, loff_t *ppos)
934 struct trace_parser parser;
935 struct seq_file *m = file->private_data;
936 struct trace_array *tr = m->private;
942 ret = tracing_update_buffers();
946 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
949 read = trace_get_user(&parser, ubuf, cnt, ppos);
951 if (read >= 0 && trace_parser_loaded((&parser))) {
954 if (*parser.buffer == '!')
957 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
965 trace_parser_put(&parser);
971 t_next(struct seq_file *m, void *v, loff_t *pos)
973 struct trace_event_file *file = v;
974 struct trace_event_call *call;
975 struct trace_array *tr = m->private;
979 list_for_each_entry_continue(file, &tr->events, list) {
980 call = file->event_call;
982 * The ftrace subsystem is for showing formats only.
983 * They can not be enabled or disabled via the event files.
985 if (call->class && call->class->reg &&
986 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
993 static void *t_start(struct seq_file *m, loff_t *pos)
995 struct trace_event_file *file;
996 struct trace_array *tr = m->private;
999 mutex_lock(&event_mutex);
1001 file = list_entry(&tr->events, struct trace_event_file, list);
1002 for (l = 0; l <= *pos; ) {
1003 file = t_next(m, file, &l);
1011 s_next(struct seq_file *m, void *v, loff_t *pos)
1013 struct trace_event_file *file = v;
1014 struct trace_array *tr = m->private;
1018 list_for_each_entry_continue(file, &tr->events, list) {
1019 if (file->flags & EVENT_FILE_FL_ENABLED)
1026 static void *s_start(struct seq_file *m, loff_t *pos)
1028 struct trace_event_file *file;
1029 struct trace_array *tr = m->private;
1032 mutex_lock(&event_mutex);
1034 file = list_entry(&tr->events, struct trace_event_file, list);
1035 for (l = 0; l <= *pos; ) {
1036 file = s_next(m, file, &l);
1043 static int t_show(struct seq_file *m, void *v)
1045 struct trace_event_file *file = v;
1046 struct trace_event_call *call = file->event_call;
1048 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1049 seq_printf(m, "%s:", call->class->system);
1050 seq_printf(m, "%s\n", trace_event_name(call));
1055 static void t_stop(struct seq_file *m, void *p)
1057 mutex_unlock(&event_mutex);
1061 __next(struct seq_file *m, void *v, loff_t *pos, int type)
1063 struct trace_array *tr = m->private;
1064 struct trace_pid_list *pid_list;
1066 if (type == TRACE_PIDS)
1067 pid_list = rcu_dereference_sched(tr->filtered_pids);
1069 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1071 return trace_pid_next(pid_list, v, pos);
1075 p_next(struct seq_file *m, void *v, loff_t *pos)
1077 return __next(m, v, pos, TRACE_PIDS);
1081 np_next(struct seq_file *m, void *v, loff_t *pos)
1083 return __next(m, v, pos, TRACE_NO_PIDS);
1086 static void *__start(struct seq_file *m, loff_t *pos, int type)
1089 struct trace_pid_list *pid_list;
1090 struct trace_array *tr = m->private;
1093 * Grab the mutex, to keep calls to p_next() having the same
1094 * tr->filtered_pids as p_start() has.
1095 * If we just passed the tr->filtered_pids around, then RCU would
1096 * have been enough, but doing that makes things more complex.
1098 mutex_lock(&event_mutex);
1099 rcu_read_lock_sched();
1101 if (type == TRACE_PIDS)
1102 pid_list = rcu_dereference_sched(tr->filtered_pids);
1104 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1109 return trace_pid_start(pid_list, pos);
1112 static void *p_start(struct seq_file *m, loff_t *pos)
1115 return __start(m, pos, TRACE_PIDS);
1118 static void *np_start(struct seq_file *m, loff_t *pos)
1121 return __start(m, pos, TRACE_NO_PIDS);
1124 static void p_stop(struct seq_file *m, void *p)
1127 rcu_read_unlock_sched();
1128 mutex_unlock(&event_mutex);
1132 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1135 struct trace_event_file *file;
1136 unsigned long flags;
1139 mutex_lock(&event_mutex);
1140 file = event_file_data(filp);
1142 flags = file->flags;
1143 mutex_unlock(&event_mutex);
1148 if (flags & EVENT_FILE_FL_ENABLED &&
1149 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1152 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1153 flags & EVENT_FILE_FL_SOFT_MODE)
1158 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1162 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1165 struct trace_event_file *file;
1169 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1173 ret = tracing_update_buffers();
1181 mutex_lock(&event_mutex);
1182 file = event_file_data(filp);
1184 ret = ftrace_event_enable_disable(file, val);
1185 mutex_unlock(&event_mutex);
1194 return ret ? ret : cnt;
1198 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1201 const char set_to_char[4] = { '?', '0', '1', 'X' };
1202 struct trace_subsystem_dir *dir = filp->private_data;
1203 struct event_subsystem *system = dir->subsystem;
1204 struct trace_event_call *call;
1205 struct trace_event_file *file;
1206 struct trace_array *tr = dir->tr;
1211 mutex_lock(&event_mutex);
1212 list_for_each_entry(file, &tr->events, list) {
1213 call = file->event_call;
1214 if (!trace_event_name(call) || !call->class || !call->class->reg)
1217 if (system && strcmp(call->class->system, system->name) != 0)
1221 * We need to find out if all the events are set
1222 * or if all events or cleared, or if we have
1225 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1228 * If we have a mixture, no need to look further.
1233 mutex_unlock(&event_mutex);
1235 buf[0] = set_to_char[set];
1238 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1244 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1247 struct trace_subsystem_dir *dir = filp->private_data;
1248 struct event_subsystem *system = dir->subsystem;
1249 const char *name = NULL;
1253 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1257 ret = tracing_update_buffers();
1261 if (val != 0 && val != 1)
1265 * Opening of "enable" adds a ref count to system,
1266 * so the name is safe to use.
1269 name = system->name;
1271 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1285 FORMAT_FIELD_SEPERATOR = 2,
1286 FORMAT_PRINTFMT = 3,
1289 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1291 struct trace_event_call *call = event_file_data(m->private);
1292 struct list_head *common_head = &ftrace_common_fields;
1293 struct list_head *head = trace_get_fields(call);
1294 struct list_head *node = v;
1298 switch ((unsigned long)v) {
1303 case FORMAT_FIELD_SEPERATOR:
1307 case FORMAT_PRINTFMT:
1313 if (node == common_head)
1314 return (void *)FORMAT_FIELD_SEPERATOR;
1315 else if (node == head)
1316 return (void *)FORMAT_PRINTFMT;
1321 static int f_show(struct seq_file *m, void *v)
1323 struct trace_event_call *call = event_file_data(m->private);
1324 struct ftrace_event_field *field;
1325 const char *array_descriptor;
1327 switch ((unsigned long)v) {
1329 seq_printf(m, "name: %s\n", trace_event_name(call));
1330 seq_printf(m, "ID: %d\n", call->event.type);
1331 seq_puts(m, "format:\n");
1334 case FORMAT_FIELD_SEPERATOR:
1338 case FORMAT_PRINTFMT:
1339 seq_printf(m, "\nprint fmt: %s\n",
1344 field = list_entry(v, struct ftrace_event_field, link);
1346 * Smartly shows the array type(except dynamic array).
1349 * If TYPE := TYPE[LEN], it is shown:
1350 * field:TYPE VAR[LEN]
1352 array_descriptor = strchr(field->type, '[');
1354 if (str_has_prefix(field->type, "__data_loc"))
1355 array_descriptor = NULL;
1357 if (!array_descriptor)
1358 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1359 field->type, field->name, field->offset,
1360 field->size, !!field->is_signed);
1362 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1363 (int)(array_descriptor - field->type),
1364 field->type, field->name,
1365 array_descriptor, field->offset,
1366 field->size, !!field->is_signed);
1371 static void *f_start(struct seq_file *m, loff_t *pos)
1373 void *p = (void *)FORMAT_HEADER;
1376 /* ->stop() is called even if ->start() fails */
1377 mutex_lock(&event_mutex);
1378 if (!event_file_data(m->private))
1379 return ERR_PTR(-ENODEV);
1381 while (l < *pos && p)
1382 p = f_next(m, p, &l);
1387 static void f_stop(struct seq_file *m, void *p)
1389 mutex_unlock(&event_mutex);
1392 static const struct seq_operations trace_format_seq_ops = {
1399 static int trace_format_open(struct inode *inode, struct file *file)
1404 /* Do we want to hide event format files on tracefs lockdown? */
1406 ret = seq_open(file, &trace_format_seq_ops);
1410 m = file->private_data;
1417 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1419 int id = (long)event_file_data(filp);
1426 len = sprintf(buf, "%d\n", id);
1428 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1432 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1435 struct trace_event_file *file;
1436 struct trace_seq *s;
1442 s = kmalloc(sizeof(*s), GFP_KERNEL);
1449 mutex_lock(&event_mutex);
1450 file = event_file_data(filp);
1452 print_event_filter(file, s);
1453 mutex_unlock(&event_mutex);
1456 r = simple_read_from_buffer(ubuf, cnt, ppos,
1457 s->buffer, trace_seq_used(s));
1465 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1468 struct trace_event_file *file;
1472 if (cnt >= PAGE_SIZE)
1475 buf = memdup_user_nul(ubuf, cnt);
1477 return PTR_ERR(buf);
1479 mutex_lock(&event_mutex);
1480 file = event_file_data(filp);
1482 err = apply_event_filter(file, buf);
1483 mutex_unlock(&event_mutex);
1494 static LIST_HEAD(event_subsystems);
1496 static int subsystem_open(struct inode *inode, struct file *filp)
1498 struct event_subsystem *system = NULL;
1499 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1500 struct trace_array *tr;
1503 if (tracing_is_disabled())
1506 /* Make sure the system still exists */
1507 mutex_lock(&event_mutex);
1508 mutex_lock(&trace_types_lock);
1509 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1510 list_for_each_entry(dir, &tr->systems, list) {
1511 if (dir == inode->i_private) {
1512 /* Don't open systems with no events */
1513 if (dir->nr_events) {
1514 __get_system_dir(dir);
1515 system = dir->subsystem;
1522 mutex_unlock(&trace_types_lock);
1523 mutex_unlock(&event_mutex);
1528 /* Some versions of gcc think dir can be uninitialized here */
1531 /* Still need to increment the ref count of the system */
1532 if (trace_array_get(tr) < 0) {
1537 ret = tracing_open_generic(inode, filp);
1539 trace_array_put(tr);
1546 static int system_tr_open(struct inode *inode, struct file *filp)
1548 struct trace_subsystem_dir *dir;
1549 struct trace_array *tr = inode->i_private;
1552 /* Make a temporary dir that has no system but points to tr */
1553 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1557 ret = tracing_open_generic_tr(inode, filp);
1563 filp->private_data = dir;
1568 static int subsystem_release(struct inode *inode, struct file *file)
1570 struct trace_subsystem_dir *dir = file->private_data;
1572 trace_array_put(dir->tr);
1575 * If dir->subsystem is NULL, then this is a temporary
1576 * descriptor that was made for a trace_array to enable
1588 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1591 struct trace_subsystem_dir *dir = filp->private_data;
1592 struct event_subsystem *system = dir->subsystem;
1593 struct trace_seq *s;
1599 s = kmalloc(sizeof(*s), GFP_KERNEL);
1605 print_subsystem_event_filter(system, s);
1606 r = simple_read_from_buffer(ubuf, cnt, ppos,
1607 s->buffer, trace_seq_used(s));
1615 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1618 struct trace_subsystem_dir *dir = filp->private_data;
1622 if (cnt >= PAGE_SIZE)
1625 buf = memdup_user_nul(ubuf, cnt);
1627 return PTR_ERR(buf);
1629 err = apply_subsystem_event_filter(dir, buf);
1640 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1642 int (*func)(struct trace_seq *s) = filp->private_data;
1643 struct trace_seq *s;
1649 s = kmalloc(sizeof(*s), GFP_KERNEL);
1656 r = simple_read_from_buffer(ubuf, cnt, ppos,
1657 s->buffer, trace_seq_used(s));
1664 static void ignore_task_cpu(void *data)
1666 struct trace_array *tr = data;
1667 struct trace_pid_list *pid_list;
1668 struct trace_pid_list *no_pid_list;
1671 * This function is called by on_each_cpu() while the
1672 * event_mutex is held.
1674 pid_list = rcu_dereference_protected(tr->filtered_pids,
1675 mutex_is_locked(&event_mutex));
1676 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
1677 mutex_is_locked(&event_mutex));
1679 this_cpu_write(tr->array_buffer.data->ignore_pid,
1680 trace_ignore_this_task(pid_list, no_pid_list, current));
1683 static void register_pid_events(struct trace_array *tr)
1686 * Register a probe that is called before all other probes
1687 * to set ignore_pid if next or prev do not match.
1688 * Register a probe this is called after all other probes
1689 * to only keep ignore_pid set if next pid matches.
1691 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1693 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1696 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1698 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1701 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1703 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1706 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1708 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1713 event_pid_write(struct file *filp, const char __user *ubuf,
1714 size_t cnt, loff_t *ppos, int type)
1716 struct seq_file *m = filp->private_data;
1717 struct trace_array *tr = m->private;
1718 struct trace_pid_list *filtered_pids = NULL;
1719 struct trace_pid_list *other_pids = NULL;
1720 struct trace_pid_list *pid_list;
1721 struct trace_event_file *file;
1727 ret = tracing_update_buffers();
1731 mutex_lock(&event_mutex);
1733 if (type == TRACE_PIDS) {
1734 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1735 lockdep_is_held(&event_mutex));
1736 other_pids = rcu_dereference_protected(tr->filtered_no_pids,
1737 lockdep_is_held(&event_mutex));
1739 filtered_pids = rcu_dereference_protected(tr->filtered_no_pids,
1740 lockdep_is_held(&event_mutex));
1741 other_pids = rcu_dereference_protected(tr->filtered_pids,
1742 lockdep_is_held(&event_mutex));
1745 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
1749 if (type == TRACE_PIDS)
1750 rcu_assign_pointer(tr->filtered_pids, pid_list);
1752 rcu_assign_pointer(tr->filtered_no_pids, pid_list);
1754 list_for_each_entry(file, &tr->events, list) {
1755 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1758 if (filtered_pids) {
1759 tracepoint_synchronize_unregister();
1760 trace_free_pid_list(filtered_pids);
1761 } else if (pid_list && !other_pids) {
1762 register_pid_events(tr);
1766 * Ignoring of pids is done at task switch. But we have to
1767 * check for those tasks that are currently running.
1768 * Always do this in case a pid was appended or removed.
1770 on_each_cpu(ignore_task_cpu, tr, 1);
1773 mutex_unlock(&event_mutex);
1782 ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1783 size_t cnt, loff_t *ppos)
1785 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
1789 ftrace_event_npid_write(struct file *filp, const char __user *ubuf,
1790 size_t cnt, loff_t *ppos)
1792 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
1795 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1796 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1797 static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
1798 static int ftrace_event_set_npid_open(struct inode *inode, struct file *file);
1799 static int ftrace_event_release(struct inode *inode, struct file *file);
1801 static const struct seq_operations show_event_seq_ops = {
1808 static const struct seq_operations show_set_event_seq_ops = {
1815 static const struct seq_operations show_set_pid_seq_ops = {
1818 .show = trace_pid_show,
1822 static const struct seq_operations show_set_no_pid_seq_ops = {
1825 .show = trace_pid_show,
1829 static const struct file_operations ftrace_avail_fops = {
1830 .open = ftrace_event_avail_open,
1832 .llseek = seq_lseek,
1833 .release = seq_release,
1836 static const struct file_operations ftrace_set_event_fops = {
1837 .open = ftrace_event_set_open,
1839 .write = ftrace_event_write,
1840 .llseek = seq_lseek,
1841 .release = ftrace_event_release,
1844 static const struct file_operations ftrace_set_event_pid_fops = {
1845 .open = ftrace_event_set_pid_open,
1847 .write = ftrace_event_pid_write,
1848 .llseek = seq_lseek,
1849 .release = ftrace_event_release,
1852 static const struct file_operations ftrace_set_event_notrace_pid_fops = {
1853 .open = ftrace_event_set_npid_open,
1855 .write = ftrace_event_npid_write,
1856 .llseek = seq_lseek,
1857 .release = ftrace_event_release,
1860 static const struct file_operations ftrace_enable_fops = {
1861 .open = tracing_open_generic,
1862 .read = event_enable_read,
1863 .write = event_enable_write,
1864 .llseek = default_llseek,
1867 static const struct file_operations ftrace_event_format_fops = {
1868 .open = trace_format_open,
1870 .llseek = seq_lseek,
1871 .release = seq_release,
1874 static const struct file_operations ftrace_event_id_fops = {
1875 .read = event_id_read,
1876 .llseek = default_llseek,
1879 static const struct file_operations ftrace_event_filter_fops = {
1880 .open = tracing_open_generic,
1881 .read = event_filter_read,
1882 .write = event_filter_write,
1883 .llseek = default_llseek,
1886 static const struct file_operations ftrace_subsystem_filter_fops = {
1887 .open = subsystem_open,
1888 .read = subsystem_filter_read,
1889 .write = subsystem_filter_write,
1890 .llseek = default_llseek,
1891 .release = subsystem_release,
1894 static const struct file_operations ftrace_system_enable_fops = {
1895 .open = subsystem_open,
1896 .read = system_enable_read,
1897 .write = system_enable_write,
1898 .llseek = default_llseek,
1899 .release = subsystem_release,
1902 static const struct file_operations ftrace_tr_enable_fops = {
1903 .open = system_tr_open,
1904 .read = system_enable_read,
1905 .write = system_enable_write,
1906 .llseek = default_llseek,
1907 .release = subsystem_release,
1910 static const struct file_operations ftrace_show_header_fops = {
1911 .open = tracing_open_generic,
1912 .read = show_header,
1913 .llseek = default_llseek,
1917 ftrace_event_open(struct inode *inode, struct file *file,
1918 const struct seq_operations *seq_ops)
1923 ret = security_locked_down(LOCKDOWN_TRACEFS);
1927 ret = seq_open(file, seq_ops);
1930 m = file->private_data;
1931 /* copy tr over to seq ops */
1932 m->private = inode->i_private;
1937 static int ftrace_event_release(struct inode *inode, struct file *file)
1939 struct trace_array *tr = inode->i_private;
1941 trace_array_put(tr);
1943 return seq_release(inode, file);
1947 ftrace_event_avail_open(struct inode *inode, struct file *file)
1949 const struct seq_operations *seq_ops = &show_event_seq_ops;
1951 /* Checks for tracefs lockdown */
1952 return ftrace_event_open(inode, file, seq_ops);
1956 ftrace_event_set_open(struct inode *inode, struct file *file)
1958 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1959 struct trace_array *tr = inode->i_private;
1962 ret = tracing_check_open_get_tr(tr);
1966 if ((file->f_mode & FMODE_WRITE) &&
1967 (file->f_flags & O_TRUNC))
1968 ftrace_clear_events(tr);
1970 ret = ftrace_event_open(inode, file, seq_ops);
1972 trace_array_put(tr);
1977 ftrace_event_set_pid_open(struct inode *inode, struct file *file)
1979 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
1980 struct trace_array *tr = inode->i_private;
1983 ret = tracing_check_open_get_tr(tr);
1987 if ((file->f_mode & FMODE_WRITE) &&
1988 (file->f_flags & O_TRUNC))
1989 ftrace_clear_event_pids(tr, TRACE_PIDS);
1991 ret = ftrace_event_open(inode, file, seq_ops);
1993 trace_array_put(tr);
1998 ftrace_event_set_npid_open(struct inode *inode, struct file *file)
2000 const struct seq_operations *seq_ops = &show_set_no_pid_seq_ops;
2001 struct trace_array *tr = inode->i_private;
2004 ret = tracing_check_open_get_tr(tr);
2008 if ((file->f_mode & FMODE_WRITE) &&
2009 (file->f_flags & O_TRUNC))
2010 ftrace_clear_event_pids(tr, TRACE_NO_PIDS);
2012 ret = ftrace_event_open(inode, file, seq_ops);
2014 trace_array_put(tr);
2018 static struct event_subsystem *
2019 create_new_subsystem(const char *name)
2021 struct event_subsystem *system;
2023 /* need to create new entry */
2024 system = kmalloc(sizeof(*system), GFP_KERNEL);
2028 system->ref_count = 1;
2030 /* Only allocate if dynamic (kprobes and modules) */
2031 system->name = kstrdup_const(name, GFP_KERNEL);
2035 system->filter = NULL;
2037 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
2038 if (!system->filter)
2041 list_add(&system->list, &event_subsystems);
2046 kfree_const(system->name);
2051 static struct dentry *
2052 event_subsystem_dir(struct trace_array *tr, const char *name,
2053 struct trace_event_file *file, struct dentry *parent)
2055 struct trace_subsystem_dir *dir;
2056 struct event_subsystem *system;
2057 struct dentry *entry;
2059 /* First see if we did not already create this dir */
2060 list_for_each_entry(dir, &tr->systems, list) {
2061 system = dir->subsystem;
2062 if (strcmp(system->name, name) == 0) {
2069 /* Now see if the system itself exists. */
2070 list_for_each_entry(system, &event_subsystems, list) {
2071 if (strcmp(system->name, name) == 0)
2074 /* Reset system variable when not found */
2075 if (&system->list == &event_subsystems)
2078 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
2083 system = create_new_subsystem(name);
2087 __get_system(system);
2089 dir->entry = tracefs_create_dir(name, parent);
2091 pr_warn("Failed to create system directory %s\n", name);
2092 __put_system(system);
2099 dir->subsystem = system;
2102 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
2103 &ftrace_subsystem_filter_fops);
2105 kfree(system->filter);
2106 system->filter = NULL;
2107 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
2110 trace_create_file("enable", 0644, dir->entry, dir,
2111 &ftrace_system_enable_fops);
2113 list_add(&dir->list, &tr->systems);
2120 /* Only print this message if failed on memory allocation */
2121 if (!dir || !system)
2122 pr_warn("No memory to create event subsystem %s\n", name);
2127 event_create_dir(struct dentry *parent, struct trace_event_file *file)
2129 struct trace_event_call *call = file->event_call;
2130 struct trace_array *tr = file->tr;
2131 struct list_head *head;
2132 struct dentry *d_events;
2137 * If the trace point header did not define TRACE_SYSTEM
2138 * then the system would be called "TRACE_SYSTEM".
2140 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
2141 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
2147 name = trace_event_name(call);
2148 file->dir = tracefs_create_dir(name, d_events);
2150 pr_warn("Could not create tracefs '%s' directory\n", name);
2154 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2155 trace_create_file("enable", 0644, file->dir, file,
2156 &ftrace_enable_fops);
2158 #ifdef CONFIG_PERF_EVENTS
2159 if (call->event.type && call->class->reg)
2160 trace_create_file("id", 0444, file->dir,
2161 (void *)(long)call->event.type,
2162 &ftrace_event_id_fops);
2166 * Other events may have the same class. Only update
2167 * the fields if they are not already defined.
2169 head = trace_get_fields(call);
2170 if (list_empty(head)) {
2171 struct trace_event_fields *field = call->class->fields_array;
2172 unsigned int offset = sizeof(struct trace_entry);
2174 for (; field->type; field++) {
2175 if (field->type == TRACE_FUNCTION_TYPE) {
2176 ret = field->define_fields(call);
2180 offset = ALIGN(offset, field->align);
2181 ret = trace_define_field(call, field->type, field->name,
2182 offset, field->size,
2183 field->is_signed, field->filter_type);
2187 offset += field->size;
2190 pr_warn("Could not initialize trace point events/%s\n",
2197 * Only event directories that can be enabled should have
2198 * triggers or filters.
2200 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
2201 trace_create_file("filter", 0644, file->dir, file,
2202 &ftrace_event_filter_fops);
2204 trace_create_file("trigger", 0644, file->dir, file,
2205 &event_trigger_fops);
2208 #ifdef CONFIG_HIST_TRIGGERS
2209 trace_create_file("hist", 0444, file->dir, file,
2212 trace_create_file("format", 0444, file->dir, call,
2213 &ftrace_event_format_fops);
2215 #ifdef CONFIG_TRACE_EVENT_INJECT
2216 if (call->event.type && call->class->reg)
2217 trace_create_file("inject", 0200, file->dir, file,
2218 &event_inject_fops);
2224 static void remove_event_from_tracers(struct trace_event_call *call)
2226 struct trace_event_file *file;
2227 struct trace_array *tr;
2229 do_for_each_event_file_safe(tr, file) {
2230 if (file->event_call != call)
2233 remove_event_file_dir(file);
2235 * The do_for_each_event_file_safe() is
2236 * a double loop. After finding the call for this
2237 * trace_array, we use break to jump to the next
2241 } while_for_each_event_file();
2244 static void event_remove(struct trace_event_call *call)
2246 struct trace_array *tr;
2247 struct trace_event_file *file;
2249 do_for_each_event_file(tr, file) {
2250 if (file->event_call != call)
2253 if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
2254 tr->clear_trace = true;
2256 ftrace_event_enable_disable(file, 0);
2258 * The do_for_each_event_file() is
2259 * a double loop. After finding the call for this
2260 * trace_array, we use break to jump to the next
2264 } while_for_each_event_file();
2266 if (call->event.funcs)
2267 __unregister_trace_event(&call->event);
2268 remove_event_from_tracers(call);
2269 list_del(&call->list);
2272 static int event_init(struct trace_event_call *call)
2277 name = trace_event_name(call);
2281 if (call->class->raw_init) {
2282 ret = call->class->raw_init(call);
2283 if (ret < 0 && ret != -ENOSYS)
2284 pr_warn("Could not initialize trace events/%s\n", name);
2291 __register_event(struct trace_event_call *call, struct module *mod)
2295 ret = event_init(call);
2299 list_add(&call->list, &ftrace_events);
2305 static char *eval_replace(char *ptr, struct trace_eval_map *map, int len)
2310 /* Find the length of the eval value as a string */
2311 elen = snprintf(ptr, 0, "%ld", map->eval_value);
2312 /* Make sure there's enough room to replace the string with the value */
2316 snprintf(ptr, elen + 1, "%ld", map->eval_value);
2318 /* Get the rest of the string of ptr */
2319 rlen = strlen(ptr + len);
2320 memmove(ptr + elen, ptr + len, rlen);
2321 /* Make sure we end the new string */
2322 ptr[elen + rlen] = 0;
2327 static void update_event_printk(struct trace_event_call *call,
2328 struct trace_eval_map *map)
2332 int len = strlen(map->eval_string);
2334 for (ptr = call->print_fmt; *ptr; ptr++) {
2348 if (isdigit(*ptr)) {
2352 /* Check for alpha chars like ULL */
2353 } while (isalnum(*ptr));
2357 * A number must have some kind of delimiter after
2358 * it, and we can ignore that too.
2362 if (isalpha(*ptr) || *ptr == '_') {
2363 if (strncmp(map->eval_string, ptr, len) == 0 &&
2364 !isalnum(ptr[len]) && ptr[len] != '_') {
2365 ptr = eval_replace(ptr, map, len);
2366 /* enum/sizeof string smaller than value */
2367 if (WARN_ON_ONCE(!ptr))
2370 * No need to decrement here, as eval_replace()
2371 * returns the pointer to the character passed
2372 * the eval, and two evals can not be placed
2373 * back to back without something in between.
2374 * We can skip that something in between.
2381 } while (isalnum(*ptr) || *ptr == '_');
2385 * If what comes after this variable is a '.' or
2386 * '->' then we can continue to ignore that string.
2388 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2389 ptr += *ptr == '.' ? 1 : 2;
2395 * Once again, we can skip the delimiter that came
2403 void trace_event_eval_update(struct trace_eval_map **map, int len)
2405 struct trace_event_call *call, *p;
2406 const char *last_system = NULL;
2411 down_write(&trace_event_sem);
2412 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2413 /* events are usually grouped together with systems */
2414 if (!last_system || call->class->system != last_system) {
2417 last_system = call->class->system;
2421 * Since calls are grouped by systems, the likelyhood that the
2422 * next call in the iteration belongs to the same system as the
2423 * previous call is high. As an optimization, we skip seaching
2424 * for a map[] that matches the call's system if the last call
2425 * was from the same system. That's what last_i is for. If the
2426 * call has the same system as the previous call, then last_i
2427 * will be the index of the first map[] that has a matching
2430 for (i = last_i; i < len; i++) {
2431 if (call->class->system == map[i]->system) {
2432 /* Save the first system if need be */
2437 update_event_printk(call, map[i]);
2441 up_write(&trace_event_sem);
2444 static struct trace_event_file *
2445 trace_create_new_event(struct trace_event_call *call,
2446 struct trace_array *tr)
2448 struct trace_event_file *file;
2450 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2454 file->event_call = call;
2456 atomic_set(&file->sm_ref, 0);
2457 atomic_set(&file->tm_ref, 0);
2458 INIT_LIST_HEAD(&file->triggers);
2459 list_add(&file->list, &tr->events);
2464 /* Add an event to a trace directory */
2466 __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2468 struct trace_event_file *file;
2470 file = trace_create_new_event(call, tr);
2474 return event_create_dir(tr->event_dir, file);
2478 * Just create a decriptor for early init. A descriptor is required
2479 * for enabling events at boot. We want to enable events before
2480 * the filesystem is initialized.
2483 __trace_early_add_new_event(struct trace_event_call *call,
2484 struct trace_array *tr)
2486 struct trace_event_file *file;
2488 file = trace_create_new_event(call, tr);
2495 struct ftrace_module_file_ops;
2496 static void __add_event_to_tracers(struct trace_event_call *call);
2498 /* Add an additional event_call dynamically */
2499 int trace_add_event_call(struct trace_event_call *call)
2502 lockdep_assert_held(&event_mutex);
2504 mutex_lock(&trace_types_lock);
2506 ret = __register_event(call, NULL);
2508 __add_event_to_tracers(call);
2510 mutex_unlock(&trace_types_lock);
2515 * Must be called under locking of trace_types_lock, event_mutex and
2518 static void __trace_remove_event_call(struct trace_event_call *call)
2521 trace_destroy_fields(call);
2522 free_event_filter(call->filter);
2523 call->filter = NULL;
2526 static int probe_remove_event_call(struct trace_event_call *call)
2528 struct trace_array *tr;
2529 struct trace_event_file *file;
2531 #ifdef CONFIG_PERF_EVENTS
2532 if (call->perf_refcount)
2535 do_for_each_event_file(tr, file) {
2536 if (file->event_call != call)
2539 * We can't rely on ftrace_event_enable_disable(enable => 0)
2540 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2541 * TRACE_REG_UNREGISTER.
2543 if (file->flags & EVENT_FILE_FL_ENABLED)
2546 * The do_for_each_event_file_safe() is
2547 * a double loop. After finding the call for this
2548 * trace_array, we use break to jump to the next
2552 } while_for_each_event_file();
2554 __trace_remove_event_call(call);
2559 /* Remove an event_call */
2560 int trace_remove_event_call(struct trace_event_call *call)
2564 lockdep_assert_held(&event_mutex);
2566 mutex_lock(&trace_types_lock);
2567 down_write(&trace_event_sem);
2568 ret = probe_remove_event_call(call);
2569 up_write(&trace_event_sem);
2570 mutex_unlock(&trace_types_lock);
2575 #define for_each_event(event, start, end) \
2576 for (event = start; \
2577 (unsigned long)event < (unsigned long)end; \
2580 #ifdef CONFIG_MODULES
2582 static void trace_module_add_events(struct module *mod)
2584 struct trace_event_call **call, **start, **end;
2586 if (!mod->num_trace_events)
2589 /* Don't add infrastructure for mods without tracepoints */
2590 if (trace_module_has_bad_taint(mod)) {
2591 pr_err("%s: module has bad taint, not creating trace events\n",
2596 start = mod->trace_events;
2597 end = mod->trace_events + mod->num_trace_events;
2599 for_each_event(call, start, end) {
2600 __register_event(*call, mod);
2601 __add_event_to_tracers(*call);
2605 static void trace_module_remove_events(struct module *mod)
2607 struct trace_event_call *call, *p;
2609 down_write(&trace_event_sem);
2610 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2611 if (call->mod == mod)
2612 __trace_remove_event_call(call);
2614 up_write(&trace_event_sem);
2617 * It is safest to reset the ring buffer if the module being unloaded
2618 * registered any events that were used. The only worry is if
2619 * a new module gets loaded, and takes on the same id as the events
2620 * of this module. When printing out the buffer, traced events left
2621 * over from this module may be passed to the new module events and
2622 * unexpected results may occur.
2624 tracing_reset_all_online_cpus();
2627 static int trace_module_notify(struct notifier_block *self,
2628 unsigned long val, void *data)
2630 struct module *mod = data;
2632 mutex_lock(&event_mutex);
2633 mutex_lock(&trace_types_lock);
2635 case MODULE_STATE_COMING:
2636 trace_module_add_events(mod);
2638 case MODULE_STATE_GOING:
2639 trace_module_remove_events(mod);
2642 mutex_unlock(&trace_types_lock);
2643 mutex_unlock(&event_mutex);
2648 static struct notifier_block trace_module_nb = {
2649 .notifier_call = trace_module_notify,
2650 .priority = 1, /* higher than trace.c module notify */
2652 #endif /* CONFIG_MODULES */
2654 /* Create a new event directory structure for a trace directory. */
2656 __trace_add_event_dirs(struct trace_array *tr)
2658 struct trace_event_call *call;
2661 list_for_each_entry(call, &ftrace_events, list) {
2662 ret = __trace_add_new_event(call, tr);
2664 pr_warn("Could not create directory for event %s\n",
2665 trace_event_name(call));
2669 /* Returns any file that matches the system and event */
2670 struct trace_event_file *
2671 __find_event_file(struct trace_array *tr, const char *system, const char *event)
2673 struct trace_event_file *file;
2674 struct trace_event_call *call;
2677 list_for_each_entry(file, &tr->events, list) {
2679 call = file->event_call;
2680 name = trace_event_name(call);
2682 if (!name || !call->class)
2685 if (strcmp(event, name) == 0 &&
2686 strcmp(system, call->class->system) == 0)
2692 /* Returns valid trace event files that match system and event */
2693 struct trace_event_file *
2694 find_event_file(struct trace_array *tr, const char *system, const char *event)
2696 struct trace_event_file *file;
2698 file = __find_event_file(tr, system, event);
2699 if (!file || !file->event_call->class->reg ||
2700 file->event_call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2707 * trace_get_event_file - Find and return a trace event file
2708 * @instance: The name of the trace instance containing the event
2709 * @system: The name of the system containing the event
2710 * @event: The name of the event
2712 * Return a trace event file given the trace instance name, trace
2713 * system, and trace event name. If the instance name is NULL, it
2714 * refers to the top-level trace array.
2716 * This function will look it up and return it if found, after calling
2717 * trace_array_get() to prevent the instance from going away, and
2718 * increment the event's module refcount to prevent it from being
2721 * To release the file, call trace_put_event_file(), which will call
2722 * trace_array_put() and decrement the event's module refcount.
2724 * Return: The trace event on success, ERR_PTR otherwise.
2726 struct trace_event_file *trace_get_event_file(const char *instance,
2730 struct trace_array *tr = top_trace_array();
2731 struct trace_event_file *file = NULL;
2735 tr = trace_array_find_get(instance);
2737 return ERR_PTR(-ENOENT);
2739 ret = trace_array_get(tr);
2741 return ERR_PTR(ret);
2744 mutex_lock(&event_mutex);
2746 file = find_event_file(tr, system, event);
2748 trace_array_put(tr);
2753 /* Don't let event modules unload while in use */
2754 ret = try_module_get(file->event_call->mod);
2756 trace_array_put(tr);
2763 mutex_unlock(&event_mutex);
2766 file = ERR_PTR(ret);
2770 EXPORT_SYMBOL_GPL(trace_get_event_file);
2773 * trace_put_event_file - Release a file from trace_get_event_file()
2774 * @file: The trace event file
2776 * If a file was retrieved using trace_get_event_file(), this should
2777 * be called when it's no longer needed. It will cancel the previous
2778 * trace_array_get() called by that function, and decrement the
2779 * event's module refcount.
2781 void trace_put_event_file(struct trace_event_file *file)
2783 mutex_lock(&event_mutex);
2784 module_put(file->event_call->mod);
2785 mutex_unlock(&event_mutex);
2787 trace_array_put(file->tr);
2789 EXPORT_SYMBOL_GPL(trace_put_event_file);
2791 #ifdef CONFIG_DYNAMIC_FTRACE
2794 #define ENABLE_EVENT_STR "enable_event"
2795 #define DISABLE_EVENT_STR "disable_event"
2797 struct event_probe_data {
2798 struct trace_event_file *file;
2799 unsigned long count;
2804 static void update_event_probe(struct event_probe_data *data)
2807 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2809 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2813 event_enable_probe(unsigned long ip, unsigned long parent_ip,
2814 struct trace_array *tr, struct ftrace_probe_ops *ops,
2817 struct ftrace_func_mapper *mapper = data;
2818 struct event_probe_data *edata;
2821 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2822 if (!pdata || !*pdata)
2826 update_event_probe(edata);
2830 event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
2831 struct trace_array *tr, struct ftrace_probe_ops *ops,
2834 struct ftrace_func_mapper *mapper = data;
2835 struct event_probe_data *edata;
2838 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2839 if (!pdata || !*pdata)
2847 /* Skip if the event is in a state we want to switch to */
2848 if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
2851 if (edata->count != -1)
2854 update_event_probe(edata);
2858 event_enable_print(struct seq_file *m, unsigned long ip,
2859 struct ftrace_probe_ops *ops, void *data)
2861 struct ftrace_func_mapper *mapper = data;
2862 struct event_probe_data *edata;
2865 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2867 if (WARN_ON_ONCE(!pdata || !*pdata))
2872 seq_printf(m, "%ps:", (void *)ip);
2874 seq_printf(m, "%s:%s:%s",
2875 edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2876 edata->file->event_call->class->system,
2877 trace_event_name(edata->file->event_call));
2879 if (edata->count == -1)
2880 seq_puts(m, ":unlimited\n");
2882 seq_printf(m, ":count=%ld\n", edata->count);
2888 event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
2889 unsigned long ip, void *init_data, void **data)
2891 struct ftrace_func_mapper *mapper = *data;
2892 struct event_probe_data *edata = init_data;
2896 mapper = allocate_ftrace_func_mapper();
2902 ret = ftrace_func_mapper_add_ip(mapper, ip, edata);
2911 static int free_probe_data(void *data)
2913 struct event_probe_data *edata = data;
2917 /* Remove the SOFT_MODE flag */
2918 __ftrace_event_enable_disable(edata->file, 0, 1);
2919 module_put(edata->file->event_call->mod);
2926 event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
2927 unsigned long ip, void *data)
2929 struct ftrace_func_mapper *mapper = data;
2930 struct event_probe_data *edata;
2935 free_ftrace_func_mapper(mapper, free_probe_data);
2939 edata = ftrace_func_mapper_remove_ip(mapper, ip);
2941 if (WARN_ON_ONCE(!edata))
2944 if (WARN_ON_ONCE(edata->ref <= 0))
2947 free_probe_data(edata);
2950 static struct ftrace_probe_ops event_enable_probe_ops = {
2951 .func = event_enable_probe,
2952 .print = event_enable_print,
2953 .init = event_enable_init,
2954 .free = event_enable_free,
2957 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2958 .func = event_enable_count_probe,
2959 .print = event_enable_print,
2960 .init = event_enable_init,
2961 .free = event_enable_free,
2964 static struct ftrace_probe_ops event_disable_probe_ops = {
2965 .func = event_enable_probe,
2966 .print = event_enable_print,
2967 .init = event_enable_init,
2968 .free = event_enable_free,
2971 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2972 .func = event_enable_count_probe,
2973 .print = event_enable_print,
2974 .init = event_enable_init,
2975 .free = event_enable_free,
2979 event_enable_func(struct trace_array *tr, struct ftrace_hash *hash,
2980 char *glob, char *cmd, char *param, int enabled)
2982 struct trace_event_file *file;
2983 struct ftrace_probe_ops *ops;
2984 struct event_probe_data *data;
2994 /* hash funcs only work with set_ftrace_filter */
2995 if (!enabled || !param)
2998 system = strsep(¶m, ":");
3002 event = strsep(¶m, ":");
3004 mutex_lock(&event_mutex);
3007 file = find_event_file(tr, system, event);
3011 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
3014 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
3016 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
3018 if (glob[0] == '!') {
3019 ret = unregister_ftrace_function_probe_func(glob+1, tr, ops);
3025 data = kzalloc(sizeof(*data), GFP_KERNEL);
3029 data->enable = enable;
3036 number = strsep(¶m, ":");
3039 if (!strlen(number))
3043 * We use the callback data field (which is a pointer)
3046 ret = kstrtoul(number, 0, &data->count);
3051 /* Don't let event modules unload while probe registered */
3052 ret = try_module_get(file->event_call->mod);
3058 ret = __ftrace_event_enable_disable(file, 1, 1);
3062 ret = register_ftrace_function_probe(glob, tr, ops, data);
3064 * The above returns on success the # of functions enabled,
3065 * but if it didn't find any functions it returns zero.
3066 * Consider no functions a failure too.
3073 /* Just return zero, not the number of enabled functions */
3076 mutex_unlock(&event_mutex);
3080 __ftrace_event_enable_disable(file, 0, 1);
3082 module_put(file->event_call->mod);
3088 static struct ftrace_func_command event_enable_cmd = {
3089 .name = ENABLE_EVENT_STR,
3090 .func = event_enable_func,
3093 static struct ftrace_func_command event_disable_cmd = {
3094 .name = DISABLE_EVENT_STR,
3095 .func = event_enable_func,
3098 static __init int register_event_cmds(void)
3102 ret = register_ftrace_command(&event_enable_cmd);
3103 if (WARN_ON(ret < 0))
3105 ret = register_ftrace_command(&event_disable_cmd);
3106 if (WARN_ON(ret < 0))
3107 unregister_ftrace_command(&event_enable_cmd);
3111 static inline int register_event_cmds(void) { return 0; }
3112 #endif /* CONFIG_DYNAMIC_FTRACE */
3115 * The top level array has already had its trace_event_file
3116 * descriptors created in order to allow for early events to
3117 * be recorded. This function is called after the tracefs has been
3118 * initialized, and we now have to create the files associated
3122 __trace_early_add_event_dirs(struct trace_array *tr)
3124 struct trace_event_file *file;
3128 list_for_each_entry(file, &tr->events, list) {
3129 ret = event_create_dir(tr->event_dir, file);
3131 pr_warn("Could not create directory for event %s\n",
3132 trace_event_name(file->event_call));
3137 * For early boot up, the top trace array requires to have
3138 * a list of events that can be enabled. This must be done before
3139 * the filesystem is set up in order to allow events to be traced
3143 __trace_early_add_events(struct trace_array *tr)
3145 struct trace_event_call *call;
3148 list_for_each_entry(call, &ftrace_events, list) {
3149 /* Early boot up should not have any modules loaded */
3150 if (WARN_ON_ONCE(call->mod))
3153 ret = __trace_early_add_new_event(call, tr);
3155 pr_warn("Could not create early event %s\n",
3156 trace_event_name(call));
3160 /* Remove the event directory structure for a trace directory. */
3162 __trace_remove_event_dirs(struct trace_array *tr)
3164 struct trace_event_file *file, *next;
3166 list_for_each_entry_safe(file, next, &tr->events, list)
3167 remove_event_file_dir(file);
3170 static void __add_event_to_tracers(struct trace_event_call *call)
3172 struct trace_array *tr;
3174 list_for_each_entry(tr, &ftrace_trace_arrays, list)
3175 __trace_add_new_event(call, tr);
3178 extern struct trace_event_call *__start_ftrace_events[];
3179 extern struct trace_event_call *__stop_ftrace_events[];
3181 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
3183 static __init int setup_trace_event(char *str)
3185 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
3186 ring_buffer_expanded = true;
3187 tracing_selftest_disabled = true;
3191 __setup("trace_event=", setup_trace_event);
3193 /* Expects to have event_mutex held when called */
3195 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
3197 struct dentry *d_events;
3198 struct dentry *entry;
3200 entry = tracefs_create_file("set_event", 0644, parent,
3201 tr, &ftrace_set_event_fops);
3203 pr_warn("Could not create tracefs 'set_event' entry\n");
3207 d_events = tracefs_create_dir("events", parent);
3209 pr_warn("Could not create tracefs 'events' directory\n");
3213 entry = trace_create_file("enable", 0644, d_events,
3214 tr, &ftrace_tr_enable_fops);
3216 pr_warn("Could not create tracefs 'enable' entry\n");
3220 /* There are not as crucial, just warn if they are not created */
3222 entry = tracefs_create_file("set_event_pid", 0644, parent,
3223 tr, &ftrace_set_event_pid_fops);
3225 pr_warn("Could not create tracefs 'set_event_pid' entry\n");
3227 entry = tracefs_create_file("set_event_notrace_pid", 0644, parent,
3228 tr, &ftrace_set_event_notrace_pid_fops);
3230 pr_warn("Could not create tracefs 'set_event_notrace_pid' entry\n");
3232 /* ring buffer internal formats */
3233 entry = trace_create_file("header_page", 0444, d_events,
3234 ring_buffer_print_page_header,
3235 &ftrace_show_header_fops);
3237 pr_warn("Could not create tracefs 'header_page' entry\n");
3239 entry = trace_create_file("header_event", 0444, d_events,
3240 ring_buffer_print_entry_header,
3241 &ftrace_show_header_fops);
3243 pr_warn("Could not create tracefs 'header_event' entry\n");
3245 tr->event_dir = d_events;
3251 * event_trace_add_tracer - add a instance of a trace_array to events
3252 * @parent: The parent dentry to place the files/directories for events in
3253 * @tr: The trace array associated with these events
3255 * When a new instance is created, it needs to set up its events
3256 * directory, as well as other files associated with events. It also
3257 * creates the event hierachry in the @parent/events directory.
3259 * Returns 0 on success.
3261 * Must be called with event_mutex held.
3263 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
3267 lockdep_assert_held(&event_mutex);
3269 ret = create_event_toplevel_files(parent, tr);
3273 down_write(&trace_event_sem);
3274 __trace_add_event_dirs(tr);
3275 up_write(&trace_event_sem);
3282 * The top trace array already had its file descriptors created.
3283 * Now the files themselves need to be created.
3286 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
3290 mutex_lock(&event_mutex);
3292 ret = create_event_toplevel_files(parent, tr);
3296 down_write(&trace_event_sem);
3297 __trace_early_add_event_dirs(tr);
3298 up_write(&trace_event_sem);
3301 mutex_unlock(&event_mutex);
3306 /* Must be called with event_mutex held */
3307 int event_trace_del_tracer(struct trace_array *tr)
3309 lockdep_assert_held(&event_mutex);
3311 /* Disable any event triggers and associated soft-disabled events */
3312 clear_event_triggers(tr);
3314 /* Clear the pid list */
3315 __ftrace_clear_event_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
3317 /* Disable any running events */
3318 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3320 /* Make sure no more events are being executed */
3321 tracepoint_synchronize_unregister();
3323 down_write(&trace_event_sem);
3324 __trace_remove_event_dirs(tr);
3325 tracefs_remove(tr->event_dir);
3326 up_write(&trace_event_sem);
3328 tr->event_dir = NULL;
3333 static __init int event_trace_memsetup(void)
3335 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3336 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3341 early_enable_events(struct trace_array *tr, bool disable_first)
3343 char *buf = bootup_event_buf;
3348 token = strsep(&buf, ",");
3354 /* Restarting syscalls requires that we stop them first */
3356 ftrace_set_clr_event(tr, token, 0);
3358 ret = ftrace_set_clr_event(tr, token, 1);
3360 pr_warn("Failed to enable trace event: %s\n", token);
3363 /* Put back the comma to allow this to be called again */
3369 static __init int event_trace_enable(void)
3371 struct trace_array *tr = top_trace_array();
3372 struct trace_event_call **iter, *call;
3378 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3381 ret = event_init(call);
3383 list_add(&call->list, &ftrace_events);
3387 * We need the top trace array to have a working set of trace
3388 * points at early init, before the debug files and directories
3389 * are created. Create the file entries now, and attach them
3390 * to the actual file dentries later.
3392 __trace_early_add_events(tr);
3394 early_enable_events(tr, false);
3396 trace_printk_start_comm();
3398 register_event_cmds();
3400 register_trigger_cmds();
3406 * event_trace_enable() is called from trace_event_init() first to
3407 * initialize events and perhaps start any events that are on the
3408 * command line. Unfortunately, there are some events that will not
3409 * start this early, like the system call tracepoints that need
3410 * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
3411 * is called before pid 1 starts, and this flag is never set, making
3412 * the syscall tracepoint never get reached, but the event is enabled
3413 * regardless (and not doing anything).
3415 static __init int event_trace_enable_again(void)
3417 struct trace_array *tr;
3419 tr = top_trace_array();
3423 early_enable_events(tr, true);
3428 early_initcall(event_trace_enable_again);
3430 __init int event_trace_init(void)
3432 struct trace_array *tr;
3433 struct dentry *d_tracer;
3434 struct dentry *entry;
3437 tr = top_trace_array();
3441 d_tracer = tracing_init_dentry();
3442 if (IS_ERR(d_tracer))
3445 entry = tracefs_create_file("available_events", 0444, d_tracer,
3446 tr, &ftrace_avail_fops);
3448 pr_warn("Could not create tracefs 'available_events' entry\n");
3450 if (trace_define_generic_fields())
3451 pr_warn("tracing: Failed to allocated generic fields");
3453 if (trace_define_common_fields())
3454 pr_warn("tracing: Failed to allocate common fields");
3456 ret = early_event_add_tracer(d_tracer, tr);
3460 #ifdef CONFIG_MODULES
3461 ret = register_module_notifier(&trace_module_nb);
3463 pr_warn("Failed to register trace events module notifier\n");
3468 void __init trace_event_init(void)
3470 event_trace_memsetup();
3471 init_ftrace_syscalls();
3472 event_trace_enable();
3475 #ifdef CONFIG_EVENT_TRACE_STARTUP_TEST
3477 static DEFINE_SPINLOCK(test_spinlock);
3478 static DEFINE_SPINLOCK(test_spinlock_irq);
3479 static DEFINE_MUTEX(test_mutex);
3481 static __init void test_work(struct work_struct *dummy)
3483 spin_lock(&test_spinlock);
3484 spin_lock_irq(&test_spinlock_irq);
3486 spin_unlock_irq(&test_spinlock_irq);
3487 spin_unlock(&test_spinlock);
3489 mutex_lock(&test_mutex);
3491 mutex_unlock(&test_mutex);
3494 static __init int event_test_thread(void *unused)
3498 test_malloc = kmalloc(1234, GFP_KERNEL);
3500 pr_info("failed to kmalloc\n");
3502 schedule_on_each_cpu(test_work);
3506 set_current_state(TASK_INTERRUPTIBLE);
3507 while (!kthread_should_stop()) {
3509 set_current_state(TASK_INTERRUPTIBLE);
3511 __set_current_state(TASK_RUNNING);
3517 * Do various things that may trigger events.
3519 static __init void event_test_stuff(void)
3521 struct task_struct *test_thread;
3523 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3525 kthread_stop(test_thread);
3529 * For every trace event defined, we will test each trace point separately,
3530 * and then by groups, and finally all trace points.
3532 static __init void event_trace_self_tests(void)
3534 struct trace_subsystem_dir *dir;
3535 struct trace_event_file *file;
3536 struct trace_event_call *call;
3537 struct event_subsystem *system;
3538 struct trace_array *tr;
3541 tr = top_trace_array();
3545 pr_info("Running tests on trace events:\n");
3547 list_for_each_entry(file, &tr->events, list) {
3549 call = file->event_call;
3551 /* Only test those that have a probe */
3552 if (!call->class || !call->class->probe)
3556 * Testing syscall events here is pretty useless, but
3557 * we still do it if configured. But this is time consuming.
3558 * What we really need is a user thread to perform the
3559 * syscalls as we test.
3561 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3562 if (call->class->system &&
3563 strcmp(call->class->system, "syscalls") == 0)
3567 pr_info("Testing event %s: ", trace_event_name(call));
3570 * If an event is already enabled, someone is using
3571 * it and the self test should not be on.
3573 if (file->flags & EVENT_FILE_FL_ENABLED) {
3574 pr_warn("Enabled event during self test!\n");
3579 ftrace_event_enable_disable(file, 1);
3581 ftrace_event_enable_disable(file, 0);
3586 /* Now test at the sub system level */
3588 pr_info("Running tests on trace event systems:\n");
3590 list_for_each_entry(dir, &tr->systems, list) {
3592 system = dir->subsystem;
3594 /* the ftrace system is special, skip it */
3595 if (strcmp(system->name, "ftrace") == 0)
3598 pr_info("Testing event system %s: ", system->name);
3600 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3601 if (WARN_ON_ONCE(ret)) {
3602 pr_warn("error enabling system %s\n",
3609 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3610 if (WARN_ON_ONCE(ret)) {
3611 pr_warn("error disabling system %s\n",
3619 /* Test with all events enabled */
3621 pr_info("Running tests on all trace events:\n");
3622 pr_info("Testing all events: ");
3624 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3625 if (WARN_ON_ONCE(ret)) {
3626 pr_warn("error enabling all events\n");
3633 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3634 if (WARN_ON_ONCE(ret)) {
3635 pr_warn("error disabling all events\n");
3642 #ifdef CONFIG_FUNCTION_TRACER
3644 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3646 static struct trace_event_file event_trace_file __initdata;
3649 function_test_events_call(unsigned long ip, unsigned long parent_ip,
3650 struct ftrace_ops *op, struct pt_regs *pt_regs)
3652 struct trace_buffer *buffer;
3653 struct ring_buffer_event *event;
3654 struct ftrace_entry *entry;
3655 unsigned long flags;
3660 pc = preempt_count();
3661 preempt_disable_notrace();
3662 cpu = raw_smp_processor_id();
3663 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3668 local_save_flags(flags);
3670 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
3671 TRACE_FN, sizeof(*entry),
3675 entry = ring_buffer_event_data(event);
3677 entry->parent_ip = parent_ip;
3679 event_trigger_unlock_commit(&event_trace_file, buffer, event,
3682 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3683 preempt_enable_notrace();
3686 static struct ftrace_ops trace_ops __initdata =
3688 .func = function_test_events_call,
3689 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
3692 static __init void event_trace_self_test_with_function(void)
3696 event_trace_file.tr = top_trace_array();
3697 if (WARN_ON(!event_trace_file.tr))
3700 ret = register_ftrace_function(&trace_ops);
3701 if (WARN_ON(ret < 0)) {
3702 pr_info("Failed to enable function tracer for event tests\n");
3705 pr_info("Running tests again, along with the function tracer\n");
3706 event_trace_self_tests();
3707 unregister_ftrace_function(&trace_ops);
3710 static __init void event_trace_self_test_with_function(void)
3715 static __init int event_trace_self_tests_init(void)
3717 if (!tracing_selftest_disabled) {
3718 event_trace_self_tests();
3719 event_trace_self_test_with_function();
3725 late_initcall(event_trace_self_tests_init);