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>
28 #include <asm/setup.h>
30 #include "trace_output.h"
33 #define TRACE_SYSTEM "TRACE_SYSTEM"
35 DEFINE_MUTEX(event_mutex);
37 LIST_HEAD(ftrace_events);
38 static LIST_HEAD(ftrace_generic_fields);
39 static LIST_HEAD(ftrace_common_fields);
41 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
43 static struct kmem_cache *field_cachep;
44 static struct kmem_cache *file_cachep;
46 static inline int system_refcount(struct event_subsystem *system)
48 return system->ref_count;
51 static int system_refcount_inc(struct event_subsystem *system)
53 return system->ref_count++;
56 static int system_refcount_dec(struct event_subsystem *system)
58 return --system->ref_count;
61 /* Double loops, do not use break, only goto's work */
62 #define do_for_each_event_file(tr, file) \
63 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
64 list_for_each_entry(file, &tr->events, list)
66 #define do_for_each_event_file_safe(tr, file) \
67 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
68 struct trace_event_file *___n; \
69 list_for_each_entry_safe(file, ___n, &tr->events, list)
71 #define while_for_each_event_file() \
74 static struct ftrace_event_field *
75 __find_event_field(struct list_head *head, char *name)
77 struct ftrace_event_field *field;
79 list_for_each_entry(field, head, link) {
80 if (!strcmp(field->name, name))
87 struct ftrace_event_field *
88 trace_find_event_field(struct trace_event_call *call, char *name)
90 struct ftrace_event_field *field;
91 struct list_head *head;
93 head = trace_get_fields(call);
94 field = __find_event_field(head, name);
98 field = __find_event_field(&ftrace_generic_fields, name);
102 return __find_event_field(&ftrace_common_fields, name);
105 static int __trace_define_field(struct list_head *head, const char *type,
106 const char *name, int offset, int size,
107 int is_signed, int filter_type)
109 struct ftrace_event_field *field;
111 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
118 if (filter_type == FILTER_OTHER)
119 field->filter_type = filter_assign_type(type);
121 field->filter_type = filter_type;
123 field->offset = offset;
125 field->is_signed = is_signed;
127 list_add(&field->link, head);
132 int trace_define_field(struct trace_event_call *call, const char *type,
133 const char *name, int offset, int size, int is_signed,
136 struct list_head *head;
138 if (WARN_ON(!call->class))
141 head = trace_get_fields(call);
142 return __trace_define_field(head, type, name, offset, size,
143 is_signed, filter_type);
145 EXPORT_SYMBOL_GPL(trace_define_field);
147 #define __generic_field(type, item, filter_type) \
148 ret = __trace_define_field(&ftrace_generic_fields, #type, \
149 #item, 0, 0, is_signed_type(type), \
154 #define __common_field(type, item) \
155 ret = __trace_define_field(&ftrace_common_fields, #type, \
157 offsetof(typeof(ent), item), \
159 is_signed_type(type), FILTER_OTHER); \
163 static int trace_define_generic_fields(void)
167 __generic_field(int, CPU, FILTER_CPU);
168 __generic_field(int, cpu, FILTER_CPU);
169 __generic_field(char *, COMM, FILTER_COMM);
170 __generic_field(char *, comm, FILTER_COMM);
175 static int trace_define_common_fields(void)
178 struct trace_entry ent;
180 __common_field(unsigned short, type);
181 __common_field(unsigned char, flags);
182 __common_field(unsigned char, preempt_count);
183 __common_field(int, pid);
188 static void trace_destroy_fields(struct trace_event_call *call)
190 struct ftrace_event_field *field, *next;
191 struct list_head *head;
193 head = trace_get_fields(call);
194 list_for_each_entry_safe(field, next, head, link) {
195 list_del(&field->link);
196 kmem_cache_free(field_cachep, field);
201 * run-time version of trace_event_get_offsets_<call>() that returns the last
202 * accessible offset of trace fields excluding __dynamic_array bytes
204 int trace_event_get_offsets(struct trace_event_call *call)
206 struct ftrace_event_field *tail;
207 struct list_head *head;
209 head = trace_get_fields(call);
211 * head->next points to the last field with the largest offset,
212 * since it was added last by trace_define_field()
214 tail = list_first_entry(head, struct ftrace_event_field, link);
215 return tail->offset + tail->size;
218 int trace_event_raw_init(struct trace_event_call *call)
222 id = register_trace_event(&call->event);
228 EXPORT_SYMBOL_GPL(trace_event_raw_init);
230 bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
232 struct trace_array *tr = trace_file->tr;
233 struct trace_array_cpu *data;
234 struct trace_pid_list *pid_list;
236 pid_list = rcu_dereference_raw(tr->filtered_pids);
240 data = this_cpu_ptr(tr->trace_buffer.data);
242 return data->ignore_pid;
244 EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
246 void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
247 struct trace_event_file *trace_file,
250 struct trace_event_call *event_call = trace_file->event_call;
252 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
253 trace_event_ignore_this_pid(trace_file))
256 local_save_flags(fbuffer->flags);
257 fbuffer->pc = preempt_count();
259 * If CONFIG_PREEMPTION is enabled, then the tracepoint itself disables
260 * preemption (adding one to the preempt_count). Since we are
261 * interested in the preempt_count at the time the tracepoint was
262 * hit, we need to subtract one to offset the increment.
264 if (IS_ENABLED(CONFIG_PREEMPTION))
266 fbuffer->trace_file = trace_file;
269 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
270 event_call->event.type, len,
271 fbuffer->flags, fbuffer->pc);
275 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
276 return fbuffer->entry;
278 EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
280 int trace_event_reg(struct trace_event_call *call,
281 enum trace_reg type, void *data)
283 struct trace_event_file *file = data;
285 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
287 case TRACE_REG_REGISTER:
288 return tracepoint_probe_register(call->tp,
291 case TRACE_REG_UNREGISTER:
292 tracepoint_probe_unregister(call->tp,
297 #ifdef CONFIG_PERF_EVENTS
298 case TRACE_REG_PERF_REGISTER:
299 return tracepoint_probe_register(call->tp,
300 call->class->perf_probe,
302 case TRACE_REG_PERF_UNREGISTER:
303 tracepoint_probe_unregister(call->tp,
304 call->class->perf_probe,
307 case TRACE_REG_PERF_OPEN:
308 case TRACE_REG_PERF_CLOSE:
309 case TRACE_REG_PERF_ADD:
310 case TRACE_REG_PERF_DEL:
316 EXPORT_SYMBOL_GPL(trace_event_reg);
318 void trace_event_enable_cmd_record(bool enable)
320 struct trace_event_file *file;
321 struct trace_array *tr;
323 mutex_lock(&event_mutex);
324 do_for_each_event_file(tr, file) {
326 if (!(file->flags & EVENT_FILE_FL_ENABLED))
330 tracing_start_cmdline_record();
331 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
333 tracing_stop_cmdline_record();
334 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
336 } while_for_each_event_file();
337 mutex_unlock(&event_mutex);
340 void trace_event_enable_tgid_record(bool enable)
342 struct trace_event_file *file;
343 struct trace_array *tr;
345 mutex_lock(&event_mutex);
346 do_for_each_event_file(tr, file) {
347 if (!(file->flags & EVENT_FILE_FL_ENABLED))
351 tracing_start_tgid_record();
352 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
354 tracing_stop_tgid_record();
355 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
358 } while_for_each_event_file();
359 mutex_unlock(&event_mutex);
362 static int __ftrace_event_enable_disable(struct trace_event_file *file,
363 int enable, int soft_disable)
365 struct trace_event_call *call = file->event_call;
366 struct trace_array *tr = file->tr;
367 unsigned long file_flags = file->flags;
374 * When soft_disable is set and enable is cleared, the sm_ref
375 * reference counter is decremented. If it reaches 0, we want
376 * to clear the SOFT_DISABLED flag but leave the event in the
377 * state that it was. That is, if the event was enabled and
378 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
379 * is set we do not want the event to be enabled before we
382 * When soft_disable is not set but the SOFT_MODE flag is,
383 * we do nothing. Do not disable the tracepoint, otherwise
384 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
387 if (atomic_dec_return(&file->sm_ref) > 0)
389 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
390 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
392 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
394 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
395 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
396 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
397 tracing_stop_cmdline_record();
398 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
401 if (file->flags & EVENT_FILE_FL_RECORDED_TGID) {
402 tracing_stop_tgid_record();
403 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
406 call->class->reg(call, TRACE_REG_UNREGISTER, file);
408 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
409 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
410 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
412 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
416 * When soft_disable is set and enable is set, we want to
417 * register the tracepoint for the event, but leave the event
418 * as is. That means, if the event was already enabled, we do
419 * nothing (but set SOFT_MODE). If the event is disabled, we
420 * set SOFT_DISABLED before enabling the event tracepoint, so
421 * it still seems to be disabled.
424 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
426 if (atomic_inc_return(&file->sm_ref) > 1)
428 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
431 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
432 bool cmd = false, tgid = false;
434 /* Keep the event disabled, when going to SOFT_MODE. */
436 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
438 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
440 tracing_start_cmdline_record();
441 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
444 if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
446 tracing_start_tgid_record();
447 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
450 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
453 tracing_stop_cmdline_record();
455 tracing_stop_tgid_record();
456 pr_info("event trace: Could not enable event "
457 "%s\n", trace_event_name(call));
460 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
462 /* WAS_ENABLED gets set but never cleared. */
463 set_bit(EVENT_FILE_FL_WAS_ENABLED_BIT, &file->flags);
468 /* Enable or disable use of trace_buffered_event */
469 if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) !=
470 (file->flags & EVENT_FILE_FL_SOFT_DISABLED)) {
471 if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
472 trace_buffered_event_enable();
474 trace_buffered_event_disable();
480 int trace_event_enable_disable(struct trace_event_file *file,
481 int enable, int soft_disable)
483 return __ftrace_event_enable_disable(file, enable, soft_disable);
486 static int ftrace_event_enable_disable(struct trace_event_file *file,
489 return __ftrace_event_enable_disable(file, enable, 0);
492 static void ftrace_clear_events(struct trace_array *tr)
494 struct trace_event_file *file;
496 mutex_lock(&event_mutex);
497 list_for_each_entry(file, &tr->events, list) {
498 ftrace_event_enable_disable(file, 0);
500 mutex_unlock(&event_mutex);
504 event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
506 struct trace_pid_list *pid_list;
507 struct trace_array *tr = data;
509 pid_list = rcu_dereference_raw(tr->filtered_pids);
510 trace_filter_add_remove_task(pid_list, NULL, task);
514 event_filter_pid_sched_process_fork(void *data,
515 struct task_struct *self,
516 struct task_struct *task)
518 struct trace_pid_list *pid_list;
519 struct trace_array *tr = data;
521 pid_list = rcu_dereference_sched(tr->filtered_pids);
522 trace_filter_add_remove_task(pid_list, self, task);
525 void trace_event_follow_fork(struct trace_array *tr, bool enable)
528 register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
530 register_trace_prio_sched_process_exit(event_filter_pid_sched_process_exit,
533 unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
535 unregister_trace_sched_process_exit(event_filter_pid_sched_process_exit,
541 event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
542 struct task_struct *prev, struct task_struct *next)
544 struct trace_array *tr = data;
545 struct trace_pid_list *pid_list;
547 pid_list = rcu_dereference_sched(tr->filtered_pids);
549 this_cpu_write(tr->trace_buffer.data->ignore_pid,
550 trace_ignore_this_task(pid_list, prev) &&
551 trace_ignore_this_task(pid_list, next));
555 event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
556 struct task_struct *prev, struct task_struct *next)
558 struct trace_array *tr = data;
559 struct trace_pid_list *pid_list;
561 pid_list = rcu_dereference_sched(tr->filtered_pids);
563 this_cpu_write(tr->trace_buffer.data->ignore_pid,
564 trace_ignore_this_task(pid_list, next));
568 event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
570 struct trace_array *tr = data;
571 struct trace_pid_list *pid_list;
573 /* Nothing to do if we are already tracing */
574 if (!this_cpu_read(tr->trace_buffer.data->ignore_pid))
577 pid_list = rcu_dereference_sched(tr->filtered_pids);
579 this_cpu_write(tr->trace_buffer.data->ignore_pid,
580 trace_ignore_this_task(pid_list, task));
584 event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
586 struct trace_array *tr = data;
587 struct trace_pid_list *pid_list;
589 /* Nothing to do if we are not tracing */
590 if (this_cpu_read(tr->trace_buffer.data->ignore_pid))
593 pid_list = rcu_dereference_sched(tr->filtered_pids);
595 /* Set tracing if current is enabled */
596 this_cpu_write(tr->trace_buffer.data->ignore_pid,
597 trace_ignore_this_task(pid_list, current));
600 static void __ftrace_clear_event_pids(struct trace_array *tr)
602 struct trace_pid_list *pid_list;
603 struct trace_event_file *file;
606 pid_list = rcu_dereference_protected(tr->filtered_pids,
607 lockdep_is_held(&event_mutex));
611 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
612 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
614 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
615 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
617 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
618 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
620 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
621 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
623 list_for_each_entry(file, &tr->events, list) {
624 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
627 for_each_possible_cpu(cpu)
628 per_cpu_ptr(tr->trace_buffer.data, cpu)->ignore_pid = false;
630 rcu_assign_pointer(tr->filtered_pids, NULL);
632 /* Wait till all users are no longer using pid filtering */
633 tracepoint_synchronize_unregister();
635 trace_free_pid_list(pid_list);
638 static void ftrace_clear_event_pids(struct trace_array *tr)
640 mutex_lock(&event_mutex);
641 __ftrace_clear_event_pids(tr);
642 mutex_unlock(&event_mutex);
645 static void __put_system(struct event_subsystem *system)
647 struct event_filter *filter = system->filter;
649 WARN_ON_ONCE(system_refcount(system) == 0);
650 if (system_refcount_dec(system))
653 list_del(&system->list);
656 kfree(filter->filter_string);
659 kfree_const(system->name);
663 static void __get_system(struct event_subsystem *system)
665 WARN_ON_ONCE(system_refcount(system) == 0);
666 system_refcount_inc(system);
669 static void __get_system_dir(struct trace_subsystem_dir *dir)
671 WARN_ON_ONCE(dir->ref_count == 0);
673 __get_system(dir->subsystem);
676 static void __put_system_dir(struct trace_subsystem_dir *dir)
678 WARN_ON_ONCE(dir->ref_count == 0);
679 /* If the subsystem is about to be freed, the dir must be too */
680 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
682 __put_system(dir->subsystem);
683 if (!--dir->ref_count)
687 static void put_system(struct trace_subsystem_dir *dir)
689 mutex_lock(&event_mutex);
690 __put_system_dir(dir);
691 mutex_unlock(&event_mutex);
694 static void remove_subsystem(struct trace_subsystem_dir *dir)
699 if (!--dir->nr_events) {
700 tracefs_remove_recursive(dir->entry);
701 list_del(&dir->list);
702 __put_system_dir(dir);
706 static void remove_event_file_dir(struct trace_event_file *file)
708 struct dentry *dir = file->dir;
709 struct dentry *child;
712 spin_lock(&dir->d_lock); /* probably unneeded */
713 list_for_each_entry(child, &dir->d_subdirs, d_child) {
714 if (d_really_is_positive(child)) /* probably unneeded */
715 d_inode(child)->i_private = NULL;
717 spin_unlock(&dir->d_lock);
719 tracefs_remove_recursive(dir);
722 list_del(&file->list);
723 remove_subsystem(file->system);
724 free_event_filter(file->filter);
725 kmem_cache_free(file_cachep, file);
729 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
732 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
733 const char *sub, const char *event, int set)
735 struct trace_event_file *file;
736 struct trace_event_call *call;
741 list_for_each_entry(file, &tr->events, list) {
743 call = file->event_call;
744 name = trace_event_name(call);
746 if (!name || !call->class || !call->class->reg)
749 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
753 strcmp(match, name) != 0 &&
754 strcmp(match, call->class->system) != 0)
757 if (sub && strcmp(sub, call->class->system) != 0)
760 if (event && strcmp(event, name) != 0)
763 ret = ftrace_event_enable_disable(file, set);
766 * Save the first error and return that. Some events
767 * may still have been enabled, but let the user
768 * know that something went wrong.
779 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
780 const char *sub, const char *event, int set)
784 mutex_lock(&event_mutex);
785 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
786 mutex_unlock(&event_mutex);
791 int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
793 char *event = NULL, *sub = NULL, *match;
797 * The buf format can be <subsystem>:<event-name>
798 * *:<event-name> means any event by that name.
799 * :<event-name> is the same.
801 * <subsystem>:* means all events in that subsystem
802 * <subsystem>: means the same.
804 * <name> (no ':') means all events in a subsystem with
805 * the name <name> or any event that matches <name>
808 match = strsep(&buf, ":");
814 if (!strlen(sub) || strcmp(sub, "*") == 0)
816 if (!strlen(event) || strcmp(event, "*") == 0)
820 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
822 /* Put back the colon to allow this to be called again */
828 EXPORT_SYMBOL_GPL(ftrace_set_clr_event);
831 * trace_set_clr_event - enable or disable an event
832 * @system: system name to match (NULL for any system)
833 * @event: event name to match (NULL for all events, within system)
834 * @set: 1 to enable, 0 to disable
836 * This is a way for other parts of the kernel to enable or disable
839 * Returns 0 on success, -EINVAL if the parameters do not match any
842 int trace_set_clr_event(const char *system, const char *event, int set)
844 struct trace_array *tr = top_trace_array();
849 return __ftrace_set_clr_event(tr, NULL, system, event, set);
851 EXPORT_SYMBOL_GPL(trace_set_clr_event);
853 /* 128 should be much more than enough */
854 #define EVENT_BUF_SIZE 127
857 ftrace_event_write(struct file *file, const char __user *ubuf,
858 size_t cnt, loff_t *ppos)
860 struct trace_parser parser;
861 struct seq_file *m = file->private_data;
862 struct trace_array *tr = m->private;
868 ret = tracing_update_buffers();
872 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
875 read = trace_get_user(&parser, ubuf, cnt, ppos);
877 if (read >= 0 && trace_parser_loaded((&parser))) {
880 if (*parser.buffer == '!')
883 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
891 trace_parser_put(&parser);
897 t_next(struct seq_file *m, void *v, loff_t *pos)
899 struct trace_event_file *file = v;
900 struct trace_event_call *call;
901 struct trace_array *tr = m->private;
905 list_for_each_entry_continue(file, &tr->events, list) {
906 call = file->event_call;
908 * The ftrace subsystem is for showing formats only.
909 * They can not be enabled or disabled via the event files.
911 if (call->class && call->class->reg &&
912 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
919 static void *t_start(struct seq_file *m, loff_t *pos)
921 struct trace_event_file *file;
922 struct trace_array *tr = m->private;
925 mutex_lock(&event_mutex);
927 file = list_entry(&tr->events, struct trace_event_file, list);
928 for (l = 0; l <= *pos; ) {
929 file = t_next(m, file, &l);
937 s_next(struct seq_file *m, void *v, loff_t *pos)
939 struct trace_event_file *file = v;
940 struct trace_array *tr = m->private;
944 list_for_each_entry_continue(file, &tr->events, list) {
945 if (file->flags & EVENT_FILE_FL_ENABLED)
952 static void *s_start(struct seq_file *m, loff_t *pos)
954 struct trace_event_file *file;
955 struct trace_array *tr = m->private;
958 mutex_lock(&event_mutex);
960 file = list_entry(&tr->events, struct trace_event_file, list);
961 for (l = 0; l <= *pos; ) {
962 file = s_next(m, file, &l);
969 static int t_show(struct seq_file *m, void *v)
971 struct trace_event_file *file = v;
972 struct trace_event_call *call = file->event_call;
974 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
975 seq_printf(m, "%s:", call->class->system);
976 seq_printf(m, "%s\n", trace_event_name(call));
981 static void t_stop(struct seq_file *m, void *p)
983 mutex_unlock(&event_mutex);
987 p_next(struct seq_file *m, void *v, loff_t *pos)
989 struct trace_array *tr = m->private;
990 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
992 return trace_pid_next(pid_list, v, pos);
995 static void *p_start(struct seq_file *m, loff_t *pos)
998 struct trace_pid_list *pid_list;
999 struct trace_array *tr = m->private;
1002 * Grab the mutex, to keep calls to p_next() having the same
1003 * tr->filtered_pids as p_start() has.
1004 * If we just passed the tr->filtered_pids around, then RCU would
1005 * have been enough, but doing that makes things more complex.
1007 mutex_lock(&event_mutex);
1008 rcu_read_lock_sched();
1010 pid_list = rcu_dereference_sched(tr->filtered_pids);
1015 return trace_pid_start(pid_list, pos);
1018 static void p_stop(struct seq_file *m, void *p)
1021 rcu_read_unlock_sched();
1022 mutex_unlock(&event_mutex);
1026 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1029 struct trace_event_file *file;
1030 unsigned long flags;
1033 mutex_lock(&event_mutex);
1034 file = event_file_data(filp);
1036 flags = file->flags;
1037 mutex_unlock(&event_mutex);
1042 if (flags & EVENT_FILE_FL_ENABLED &&
1043 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1046 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1047 flags & EVENT_FILE_FL_SOFT_MODE)
1052 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1056 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1059 struct trace_event_file *file;
1063 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1067 ret = tracing_update_buffers();
1075 mutex_lock(&event_mutex);
1076 file = event_file_data(filp);
1078 ret = ftrace_event_enable_disable(file, val);
1079 mutex_unlock(&event_mutex);
1088 return ret ? ret : cnt;
1092 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1095 const char set_to_char[4] = { '?', '0', '1', 'X' };
1096 struct trace_subsystem_dir *dir = filp->private_data;
1097 struct event_subsystem *system = dir->subsystem;
1098 struct trace_event_call *call;
1099 struct trace_event_file *file;
1100 struct trace_array *tr = dir->tr;
1105 mutex_lock(&event_mutex);
1106 list_for_each_entry(file, &tr->events, list) {
1107 call = file->event_call;
1108 if (!trace_event_name(call) || !call->class || !call->class->reg)
1111 if (system && strcmp(call->class->system, system->name) != 0)
1115 * We need to find out if all the events are set
1116 * or if all events or cleared, or if we have
1119 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1122 * If we have a mixture, no need to look further.
1127 mutex_unlock(&event_mutex);
1129 buf[0] = set_to_char[set];
1132 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1138 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1141 struct trace_subsystem_dir *dir = filp->private_data;
1142 struct event_subsystem *system = dir->subsystem;
1143 const char *name = NULL;
1147 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1151 ret = tracing_update_buffers();
1155 if (val != 0 && val != 1)
1159 * Opening of "enable" adds a ref count to system,
1160 * so the name is safe to use.
1163 name = system->name;
1165 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1179 FORMAT_FIELD_SEPERATOR = 2,
1180 FORMAT_PRINTFMT = 3,
1183 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1185 struct trace_event_call *call = event_file_data(m->private);
1186 struct list_head *common_head = &ftrace_common_fields;
1187 struct list_head *head = trace_get_fields(call);
1188 struct list_head *node = v;
1192 switch ((unsigned long)v) {
1197 case FORMAT_FIELD_SEPERATOR:
1201 case FORMAT_PRINTFMT:
1207 if (node == common_head)
1208 return (void *)FORMAT_FIELD_SEPERATOR;
1209 else if (node == head)
1210 return (void *)FORMAT_PRINTFMT;
1215 static int f_show(struct seq_file *m, void *v)
1217 struct trace_event_call *call = event_file_data(m->private);
1218 struct ftrace_event_field *field;
1219 const char *array_descriptor;
1221 switch ((unsigned long)v) {
1223 seq_printf(m, "name: %s\n", trace_event_name(call));
1224 seq_printf(m, "ID: %d\n", call->event.type);
1225 seq_puts(m, "format:\n");
1228 case FORMAT_FIELD_SEPERATOR:
1232 case FORMAT_PRINTFMT:
1233 seq_printf(m, "\nprint fmt: %s\n",
1238 field = list_entry(v, struct ftrace_event_field, link);
1240 * Smartly shows the array type(except dynamic array).
1243 * If TYPE := TYPE[LEN], it is shown:
1244 * field:TYPE VAR[LEN]
1246 array_descriptor = strchr(field->type, '[');
1248 if (str_has_prefix(field->type, "__data_loc"))
1249 array_descriptor = NULL;
1251 if (!array_descriptor)
1252 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1253 field->type, field->name, field->offset,
1254 field->size, !!field->is_signed);
1256 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1257 (int)(array_descriptor - field->type),
1258 field->type, field->name,
1259 array_descriptor, field->offset,
1260 field->size, !!field->is_signed);
1265 static void *f_start(struct seq_file *m, loff_t *pos)
1267 void *p = (void *)FORMAT_HEADER;
1270 /* ->stop() is called even if ->start() fails */
1271 mutex_lock(&event_mutex);
1272 if (!event_file_data(m->private))
1273 return ERR_PTR(-ENODEV);
1275 while (l < *pos && p)
1276 p = f_next(m, p, &l);
1281 static void f_stop(struct seq_file *m, void *p)
1283 mutex_unlock(&event_mutex);
1286 static const struct seq_operations trace_format_seq_ops = {
1293 static int trace_format_open(struct inode *inode, struct file *file)
1298 /* Do we want to hide event format files on tracefs lockdown? */
1300 ret = seq_open(file, &trace_format_seq_ops);
1304 m = file->private_data;
1311 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1313 int id = (long)event_file_data(filp);
1320 len = sprintf(buf, "%d\n", id);
1322 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1326 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1329 struct trace_event_file *file;
1330 struct trace_seq *s;
1336 s = kmalloc(sizeof(*s), GFP_KERNEL);
1343 mutex_lock(&event_mutex);
1344 file = event_file_data(filp);
1346 print_event_filter(file, s);
1347 mutex_unlock(&event_mutex);
1350 r = simple_read_from_buffer(ubuf, cnt, ppos,
1351 s->buffer, trace_seq_used(s));
1359 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1362 struct trace_event_file *file;
1366 if (cnt >= PAGE_SIZE)
1369 buf = memdup_user_nul(ubuf, cnt);
1371 return PTR_ERR(buf);
1373 mutex_lock(&event_mutex);
1374 file = event_file_data(filp);
1376 err = apply_event_filter(file, buf);
1377 mutex_unlock(&event_mutex);
1388 static LIST_HEAD(event_subsystems);
1390 static int subsystem_open(struct inode *inode, struct file *filp)
1392 struct event_subsystem *system = NULL;
1393 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1394 struct trace_array *tr;
1397 if (tracing_is_disabled())
1400 /* Make sure the system still exists */
1401 mutex_lock(&event_mutex);
1402 mutex_lock(&trace_types_lock);
1403 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1404 list_for_each_entry(dir, &tr->systems, list) {
1405 if (dir == inode->i_private) {
1406 /* Don't open systems with no events */
1407 if (dir->nr_events) {
1408 __get_system_dir(dir);
1409 system = dir->subsystem;
1416 mutex_unlock(&trace_types_lock);
1417 mutex_unlock(&event_mutex);
1422 /* Some versions of gcc think dir can be uninitialized here */
1425 /* Still need to increment the ref count of the system */
1426 if (trace_array_get(tr) < 0) {
1431 ret = tracing_open_generic(inode, filp);
1433 trace_array_put(tr);
1440 static int system_tr_open(struct inode *inode, struct file *filp)
1442 struct trace_subsystem_dir *dir;
1443 struct trace_array *tr = inode->i_private;
1446 /* Make a temporary dir that has no system but points to tr */
1447 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1451 ret = tracing_open_generic_tr(inode, filp);
1457 filp->private_data = dir;
1462 static int subsystem_release(struct inode *inode, struct file *file)
1464 struct trace_subsystem_dir *dir = file->private_data;
1466 trace_array_put(dir->tr);
1469 * If dir->subsystem is NULL, then this is a temporary
1470 * descriptor that was made for a trace_array to enable
1482 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1485 struct trace_subsystem_dir *dir = filp->private_data;
1486 struct event_subsystem *system = dir->subsystem;
1487 struct trace_seq *s;
1493 s = kmalloc(sizeof(*s), GFP_KERNEL);
1499 print_subsystem_event_filter(system, s);
1500 r = simple_read_from_buffer(ubuf, cnt, ppos,
1501 s->buffer, trace_seq_used(s));
1509 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1512 struct trace_subsystem_dir *dir = filp->private_data;
1516 if (cnt >= PAGE_SIZE)
1519 buf = memdup_user_nul(ubuf, cnt);
1521 return PTR_ERR(buf);
1523 err = apply_subsystem_event_filter(dir, buf);
1534 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1536 int (*func)(struct trace_seq *s) = filp->private_data;
1537 struct trace_seq *s;
1543 s = kmalloc(sizeof(*s), GFP_KERNEL);
1550 r = simple_read_from_buffer(ubuf, cnt, ppos,
1551 s->buffer, trace_seq_used(s));
1558 static void ignore_task_cpu(void *data)
1560 struct trace_array *tr = data;
1561 struct trace_pid_list *pid_list;
1564 * This function is called by on_each_cpu() while the
1565 * event_mutex is held.
1567 pid_list = rcu_dereference_protected(tr->filtered_pids,
1568 mutex_is_locked(&event_mutex));
1570 this_cpu_write(tr->trace_buffer.data->ignore_pid,
1571 trace_ignore_this_task(pid_list, current));
1575 ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1576 size_t cnt, loff_t *ppos)
1578 struct seq_file *m = filp->private_data;
1579 struct trace_array *tr = m->private;
1580 struct trace_pid_list *filtered_pids = NULL;
1581 struct trace_pid_list *pid_list;
1582 struct trace_event_file *file;
1588 ret = tracing_update_buffers();
1592 mutex_lock(&event_mutex);
1594 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1595 lockdep_is_held(&event_mutex));
1597 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
1601 rcu_assign_pointer(tr->filtered_pids, pid_list);
1603 list_for_each_entry(file, &tr->events, list) {
1604 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1607 if (filtered_pids) {
1608 tracepoint_synchronize_unregister();
1609 trace_free_pid_list(filtered_pids);
1610 } else if (pid_list) {
1612 * Register a probe that is called before all other probes
1613 * to set ignore_pid if next or prev do not match.
1614 * Register a probe this is called after all other probes
1615 * to only keep ignore_pid set if next pid matches.
1617 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1619 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1622 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1624 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1627 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1629 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1632 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1634 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1639 * Ignoring of pids is done at task switch. But we have to
1640 * check for those tasks that are currently running.
1641 * Always do this in case a pid was appended or removed.
1643 on_each_cpu(ignore_task_cpu, tr, 1);
1646 mutex_unlock(&event_mutex);
1654 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1655 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1656 static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
1657 static int ftrace_event_release(struct inode *inode, struct file *file);
1659 static const struct seq_operations show_event_seq_ops = {
1666 static const struct seq_operations show_set_event_seq_ops = {
1673 static const struct seq_operations show_set_pid_seq_ops = {
1676 .show = trace_pid_show,
1680 static const struct file_operations ftrace_avail_fops = {
1681 .open = ftrace_event_avail_open,
1683 .llseek = seq_lseek,
1684 .release = seq_release,
1687 static const struct file_operations ftrace_set_event_fops = {
1688 .open = ftrace_event_set_open,
1690 .write = ftrace_event_write,
1691 .llseek = seq_lseek,
1692 .release = ftrace_event_release,
1695 static const struct file_operations ftrace_set_event_pid_fops = {
1696 .open = ftrace_event_set_pid_open,
1698 .write = ftrace_event_pid_write,
1699 .llseek = seq_lseek,
1700 .release = ftrace_event_release,
1703 static const struct file_operations ftrace_enable_fops = {
1704 .open = tracing_open_generic,
1705 .read = event_enable_read,
1706 .write = event_enable_write,
1707 .llseek = default_llseek,
1710 static const struct file_operations ftrace_event_format_fops = {
1711 .open = trace_format_open,
1713 .llseek = seq_lseek,
1714 .release = seq_release,
1717 static const struct file_operations ftrace_event_id_fops = {
1718 .read = event_id_read,
1719 .llseek = default_llseek,
1722 static const struct file_operations ftrace_event_filter_fops = {
1723 .open = tracing_open_generic,
1724 .read = event_filter_read,
1725 .write = event_filter_write,
1726 .llseek = default_llseek,
1729 static const struct file_operations ftrace_subsystem_filter_fops = {
1730 .open = subsystem_open,
1731 .read = subsystem_filter_read,
1732 .write = subsystem_filter_write,
1733 .llseek = default_llseek,
1734 .release = subsystem_release,
1737 static const struct file_operations ftrace_system_enable_fops = {
1738 .open = subsystem_open,
1739 .read = system_enable_read,
1740 .write = system_enable_write,
1741 .llseek = default_llseek,
1742 .release = subsystem_release,
1745 static const struct file_operations ftrace_tr_enable_fops = {
1746 .open = system_tr_open,
1747 .read = system_enable_read,
1748 .write = system_enable_write,
1749 .llseek = default_llseek,
1750 .release = subsystem_release,
1753 static const struct file_operations ftrace_show_header_fops = {
1754 .open = tracing_open_generic,
1755 .read = show_header,
1756 .llseek = default_llseek,
1760 ftrace_event_open(struct inode *inode, struct file *file,
1761 const struct seq_operations *seq_ops)
1766 ret = security_locked_down(LOCKDOWN_TRACEFS);
1770 ret = seq_open(file, seq_ops);
1773 m = file->private_data;
1774 /* copy tr over to seq ops */
1775 m->private = inode->i_private;
1780 static int ftrace_event_release(struct inode *inode, struct file *file)
1782 struct trace_array *tr = inode->i_private;
1784 trace_array_put(tr);
1786 return seq_release(inode, file);
1790 ftrace_event_avail_open(struct inode *inode, struct file *file)
1792 const struct seq_operations *seq_ops = &show_event_seq_ops;
1794 /* Checks for tracefs lockdown */
1795 return ftrace_event_open(inode, file, seq_ops);
1799 ftrace_event_set_open(struct inode *inode, struct file *file)
1801 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1802 struct trace_array *tr = inode->i_private;
1805 ret = tracing_check_open_get_tr(tr);
1809 if ((file->f_mode & FMODE_WRITE) &&
1810 (file->f_flags & O_TRUNC))
1811 ftrace_clear_events(tr);
1813 ret = ftrace_event_open(inode, file, seq_ops);
1815 trace_array_put(tr);
1820 ftrace_event_set_pid_open(struct inode *inode, struct file *file)
1822 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
1823 struct trace_array *tr = inode->i_private;
1826 ret = tracing_check_open_get_tr(tr);
1830 if ((file->f_mode & FMODE_WRITE) &&
1831 (file->f_flags & O_TRUNC))
1832 ftrace_clear_event_pids(tr);
1834 ret = ftrace_event_open(inode, file, seq_ops);
1836 trace_array_put(tr);
1840 static struct event_subsystem *
1841 create_new_subsystem(const char *name)
1843 struct event_subsystem *system;
1845 /* need to create new entry */
1846 system = kmalloc(sizeof(*system), GFP_KERNEL);
1850 system->ref_count = 1;
1852 /* Only allocate if dynamic (kprobes and modules) */
1853 system->name = kstrdup_const(name, GFP_KERNEL);
1857 system->filter = NULL;
1859 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1860 if (!system->filter)
1863 list_add(&system->list, &event_subsystems);
1868 kfree_const(system->name);
1873 static struct dentry *
1874 event_subsystem_dir(struct trace_array *tr, const char *name,
1875 struct trace_event_file *file, struct dentry *parent)
1877 struct trace_subsystem_dir *dir;
1878 struct event_subsystem *system;
1879 struct dentry *entry;
1881 /* First see if we did not already create this dir */
1882 list_for_each_entry(dir, &tr->systems, list) {
1883 system = dir->subsystem;
1884 if (strcmp(system->name, name) == 0) {
1891 /* Now see if the system itself exists. */
1892 list_for_each_entry(system, &event_subsystems, list) {
1893 if (strcmp(system->name, name) == 0)
1896 /* Reset system variable when not found */
1897 if (&system->list == &event_subsystems)
1900 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1905 system = create_new_subsystem(name);
1909 __get_system(system);
1911 dir->entry = tracefs_create_dir(name, parent);
1913 pr_warn("Failed to create system directory %s\n", name);
1914 __put_system(system);
1921 dir->subsystem = system;
1924 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
1925 &ftrace_subsystem_filter_fops);
1927 kfree(system->filter);
1928 system->filter = NULL;
1929 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
1932 trace_create_file("enable", 0644, dir->entry, dir,
1933 &ftrace_system_enable_fops);
1935 list_add(&dir->list, &tr->systems);
1942 /* Only print this message if failed on memory allocation */
1943 if (!dir || !system)
1944 pr_warn("No memory to create event subsystem %s\n", name);
1949 event_create_dir(struct dentry *parent, struct trace_event_file *file)
1951 struct trace_event_call *call = file->event_call;
1952 struct trace_array *tr = file->tr;
1953 struct list_head *head;
1954 struct dentry *d_events;
1959 * If the trace point header did not define TRACE_SYSTEM
1960 * then the system would be called "TRACE_SYSTEM".
1962 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1963 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1969 name = trace_event_name(call);
1970 file->dir = tracefs_create_dir(name, d_events);
1972 pr_warn("Could not create tracefs '%s' directory\n", name);
1976 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1977 trace_create_file("enable", 0644, file->dir, file,
1978 &ftrace_enable_fops);
1980 #ifdef CONFIG_PERF_EVENTS
1981 if (call->event.type && call->class->reg)
1982 trace_create_file("id", 0444, file->dir,
1983 (void *)(long)call->event.type,
1984 &ftrace_event_id_fops);
1988 * Other events may have the same class. Only update
1989 * the fields if they are not already defined.
1991 head = trace_get_fields(call);
1992 if (list_empty(head)) {
1993 ret = call->class->define_fields(call);
1995 pr_warn("Could not initialize trace point events/%s\n",
2002 * Only event directories that can be enabled should have
2003 * triggers or filters.
2005 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
2006 trace_create_file("filter", 0644, file->dir, file,
2007 &ftrace_event_filter_fops);
2009 trace_create_file("trigger", 0644, file->dir, file,
2010 &event_trigger_fops);
2013 #ifdef CONFIG_HIST_TRIGGERS
2014 trace_create_file("hist", 0444, file->dir, file,
2017 trace_create_file("format", 0444, file->dir, call,
2018 &ftrace_event_format_fops);
2023 static void remove_event_from_tracers(struct trace_event_call *call)
2025 struct trace_event_file *file;
2026 struct trace_array *tr;
2028 do_for_each_event_file_safe(tr, file) {
2029 if (file->event_call != call)
2032 remove_event_file_dir(file);
2034 * The do_for_each_event_file_safe() is
2035 * a double loop. After finding the call for this
2036 * trace_array, we use break to jump to the next
2040 } while_for_each_event_file();
2043 static void event_remove(struct trace_event_call *call)
2045 struct trace_array *tr;
2046 struct trace_event_file *file;
2048 do_for_each_event_file(tr, file) {
2049 if (file->event_call != call)
2052 if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
2053 tr->clear_trace = true;
2055 ftrace_event_enable_disable(file, 0);
2057 * The do_for_each_event_file() is
2058 * a double loop. After finding the call for this
2059 * trace_array, we use break to jump to the next
2063 } while_for_each_event_file();
2065 if (call->event.funcs)
2066 __unregister_trace_event(&call->event);
2067 remove_event_from_tracers(call);
2068 list_del(&call->list);
2071 static int event_init(struct trace_event_call *call)
2076 name = trace_event_name(call);
2080 if (call->class->raw_init) {
2081 ret = call->class->raw_init(call);
2082 if (ret < 0 && ret != -ENOSYS)
2083 pr_warn("Could not initialize trace events/%s\n", name);
2090 __register_event(struct trace_event_call *call, struct module *mod)
2094 ret = event_init(call);
2098 list_add(&call->list, &ftrace_events);
2104 static char *eval_replace(char *ptr, struct trace_eval_map *map, int len)
2109 /* Find the length of the eval value as a string */
2110 elen = snprintf(ptr, 0, "%ld", map->eval_value);
2111 /* Make sure there's enough room to replace the string with the value */
2115 snprintf(ptr, elen + 1, "%ld", map->eval_value);
2117 /* Get the rest of the string of ptr */
2118 rlen = strlen(ptr + len);
2119 memmove(ptr + elen, ptr + len, rlen);
2120 /* Make sure we end the new string */
2121 ptr[elen + rlen] = 0;
2126 static void update_event_printk(struct trace_event_call *call,
2127 struct trace_eval_map *map)
2131 int len = strlen(map->eval_string);
2133 for (ptr = call->print_fmt; *ptr; ptr++) {
2147 if (isdigit(*ptr)) {
2151 /* Check for alpha chars like ULL */
2152 } while (isalnum(*ptr));
2156 * A number must have some kind of delimiter after
2157 * it, and we can ignore that too.
2161 if (isalpha(*ptr) || *ptr == '_') {
2162 if (strncmp(map->eval_string, ptr, len) == 0 &&
2163 !isalnum(ptr[len]) && ptr[len] != '_') {
2164 ptr = eval_replace(ptr, map, len);
2165 /* enum/sizeof string smaller than value */
2166 if (WARN_ON_ONCE(!ptr))
2169 * No need to decrement here, as eval_replace()
2170 * returns the pointer to the character passed
2171 * the eval, and two evals can not be placed
2172 * back to back without something in between.
2173 * We can skip that something in between.
2180 } while (isalnum(*ptr) || *ptr == '_');
2184 * If what comes after this variable is a '.' or
2185 * '->' then we can continue to ignore that string.
2187 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2188 ptr += *ptr == '.' ? 1 : 2;
2194 * Once again, we can skip the delimiter that came
2202 void trace_event_eval_update(struct trace_eval_map **map, int len)
2204 struct trace_event_call *call, *p;
2205 const char *last_system = NULL;
2210 down_write(&trace_event_sem);
2211 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2212 /* events are usually grouped together with systems */
2213 if (!last_system || call->class->system != last_system) {
2216 last_system = call->class->system;
2220 * Since calls are grouped by systems, the likelyhood that the
2221 * next call in the iteration belongs to the same system as the
2222 * previous call is high. As an optimization, we skip seaching
2223 * for a map[] that matches the call's system if the last call
2224 * was from the same system. That's what last_i is for. If the
2225 * call has the same system as the previous call, then last_i
2226 * will be the index of the first map[] that has a matching
2229 for (i = last_i; i < len; i++) {
2230 if (call->class->system == map[i]->system) {
2231 /* Save the first system if need be */
2236 update_event_printk(call, map[i]);
2240 up_write(&trace_event_sem);
2243 static struct trace_event_file *
2244 trace_create_new_event(struct trace_event_call *call,
2245 struct trace_array *tr)
2247 struct trace_event_file *file;
2249 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2253 file->event_call = call;
2255 atomic_set(&file->sm_ref, 0);
2256 atomic_set(&file->tm_ref, 0);
2257 INIT_LIST_HEAD(&file->triggers);
2258 list_add(&file->list, &tr->events);
2263 /* Add an event to a trace directory */
2265 __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2267 struct trace_event_file *file;
2269 file = trace_create_new_event(call, tr);
2273 return event_create_dir(tr->event_dir, file);
2277 * Just create a decriptor for early init. A descriptor is required
2278 * for enabling events at boot. We want to enable events before
2279 * the filesystem is initialized.
2282 __trace_early_add_new_event(struct trace_event_call *call,
2283 struct trace_array *tr)
2285 struct trace_event_file *file;
2287 file = trace_create_new_event(call, tr);
2294 struct ftrace_module_file_ops;
2295 static void __add_event_to_tracers(struct trace_event_call *call);
2297 /* Add an additional event_call dynamically */
2298 int trace_add_event_call(struct trace_event_call *call)
2301 lockdep_assert_held(&event_mutex);
2303 mutex_lock(&trace_types_lock);
2305 ret = __register_event(call, NULL);
2307 __add_event_to_tracers(call);
2309 mutex_unlock(&trace_types_lock);
2314 * Must be called under locking of trace_types_lock, event_mutex and
2317 static void __trace_remove_event_call(struct trace_event_call *call)
2320 trace_destroy_fields(call);
2321 free_event_filter(call->filter);
2322 call->filter = NULL;
2325 static int probe_remove_event_call(struct trace_event_call *call)
2327 struct trace_array *tr;
2328 struct trace_event_file *file;
2330 #ifdef CONFIG_PERF_EVENTS
2331 if (call->perf_refcount)
2334 do_for_each_event_file(tr, file) {
2335 if (file->event_call != call)
2338 * We can't rely on ftrace_event_enable_disable(enable => 0)
2339 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2340 * TRACE_REG_UNREGISTER.
2342 if (file->flags & EVENT_FILE_FL_ENABLED)
2345 * The do_for_each_event_file_safe() is
2346 * a double loop. After finding the call for this
2347 * trace_array, we use break to jump to the next
2351 } while_for_each_event_file();
2353 __trace_remove_event_call(call);
2358 /* Remove an event_call */
2359 int trace_remove_event_call(struct trace_event_call *call)
2363 lockdep_assert_held(&event_mutex);
2365 mutex_lock(&trace_types_lock);
2366 down_write(&trace_event_sem);
2367 ret = probe_remove_event_call(call);
2368 up_write(&trace_event_sem);
2369 mutex_unlock(&trace_types_lock);
2374 #define for_each_event(event, start, end) \
2375 for (event = start; \
2376 (unsigned long)event < (unsigned long)end; \
2379 #ifdef CONFIG_MODULES
2381 static void trace_module_add_events(struct module *mod)
2383 struct trace_event_call **call, **start, **end;
2385 if (!mod->num_trace_events)
2388 /* Don't add infrastructure for mods without tracepoints */
2389 if (trace_module_has_bad_taint(mod)) {
2390 pr_err("%s: module has bad taint, not creating trace events\n",
2395 start = mod->trace_events;
2396 end = mod->trace_events + mod->num_trace_events;
2398 for_each_event(call, start, end) {
2399 __register_event(*call, mod);
2400 __add_event_to_tracers(*call);
2404 static void trace_module_remove_events(struct module *mod)
2406 struct trace_event_call *call, *p;
2408 down_write(&trace_event_sem);
2409 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2410 if (call->mod == mod)
2411 __trace_remove_event_call(call);
2413 up_write(&trace_event_sem);
2416 * It is safest to reset the ring buffer if the module being unloaded
2417 * registered any events that were used. The only worry is if
2418 * a new module gets loaded, and takes on the same id as the events
2419 * of this module. When printing out the buffer, traced events left
2420 * over from this module may be passed to the new module events and
2421 * unexpected results may occur.
2423 tracing_reset_all_online_cpus();
2426 static int trace_module_notify(struct notifier_block *self,
2427 unsigned long val, void *data)
2429 struct module *mod = data;
2431 mutex_lock(&event_mutex);
2432 mutex_lock(&trace_types_lock);
2434 case MODULE_STATE_COMING:
2435 trace_module_add_events(mod);
2437 case MODULE_STATE_GOING:
2438 trace_module_remove_events(mod);
2441 mutex_unlock(&trace_types_lock);
2442 mutex_unlock(&event_mutex);
2447 static struct notifier_block trace_module_nb = {
2448 .notifier_call = trace_module_notify,
2449 .priority = 1, /* higher than trace.c module notify */
2451 #endif /* CONFIG_MODULES */
2453 /* Create a new event directory structure for a trace directory. */
2455 __trace_add_event_dirs(struct trace_array *tr)
2457 struct trace_event_call *call;
2460 list_for_each_entry(call, &ftrace_events, list) {
2461 ret = __trace_add_new_event(call, tr);
2463 pr_warn("Could not create directory for event %s\n",
2464 trace_event_name(call));
2468 /* Returns any file that matches the system and event */
2469 struct trace_event_file *
2470 __find_event_file(struct trace_array *tr, const char *system, const char *event)
2472 struct trace_event_file *file;
2473 struct trace_event_call *call;
2476 list_for_each_entry(file, &tr->events, list) {
2478 call = file->event_call;
2479 name = trace_event_name(call);
2481 if (!name || !call->class)
2484 if (strcmp(event, name) == 0 &&
2485 strcmp(system, call->class->system) == 0)
2491 /* Returns valid trace event files that match system and event */
2492 struct trace_event_file *
2493 find_event_file(struct trace_array *tr, const char *system, const char *event)
2495 struct trace_event_file *file;
2497 file = __find_event_file(tr, system, event);
2498 if (!file || !file->event_call->class->reg ||
2499 file->event_call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2505 #ifdef CONFIG_DYNAMIC_FTRACE
2508 #define ENABLE_EVENT_STR "enable_event"
2509 #define DISABLE_EVENT_STR "disable_event"
2511 struct event_probe_data {
2512 struct trace_event_file *file;
2513 unsigned long count;
2518 static void update_event_probe(struct event_probe_data *data)
2521 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2523 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2527 event_enable_probe(unsigned long ip, unsigned long parent_ip,
2528 struct trace_array *tr, struct ftrace_probe_ops *ops,
2531 struct ftrace_func_mapper *mapper = data;
2532 struct event_probe_data *edata;
2535 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2536 if (!pdata || !*pdata)
2540 update_event_probe(edata);
2544 event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
2545 struct trace_array *tr, struct ftrace_probe_ops *ops,
2548 struct ftrace_func_mapper *mapper = data;
2549 struct event_probe_data *edata;
2552 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2553 if (!pdata || !*pdata)
2561 /* Skip if the event is in a state we want to switch to */
2562 if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
2565 if (edata->count != -1)
2568 update_event_probe(edata);
2572 event_enable_print(struct seq_file *m, unsigned long ip,
2573 struct ftrace_probe_ops *ops, void *data)
2575 struct ftrace_func_mapper *mapper = data;
2576 struct event_probe_data *edata;
2579 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2581 if (WARN_ON_ONCE(!pdata || !*pdata))
2586 seq_printf(m, "%ps:", (void *)ip);
2588 seq_printf(m, "%s:%s:%s",
2589 edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2590 edata->file->event_call->class->system,
2591 trace_event_name(edata->file->event_call));
2593 if (edata->count == -1)
2594 seq_puts(m, ":unlimited\n");
2596 seq_printf(m, ":count=%ld\n", edata->count);
2602 event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
2603 unsigned long ip, void *init_data, void **data)
2605 struct ftrace_func_mapper *mapper = *data;
2606 struct event_probe_data *edata = init_data;
2610 mapper = allocate_ftrace_func_mapper();
2616 ret = ftrace_func_mapper_add_ip(mapper, ip, edata);
2625 static int free_probe_data(void *data)
2627 struct event_probe_data *edata = data;
2631 /* Remove the SOFT_MODE flag */
2632 __ftrace_event_enable_disable(edata->file, 0, 1);
2633 module_put(edata->file->event_call->mod);
2640 event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
2641 unsigned long ip, void *data)
2643 struct ftrace_func_mapper *mapper = data;
2644 struct event_probe_data *edata;
2649 free_ftrace_func_mapper(mapper, free_probe_data);
2653 edata = ftrace_func_mapper_remove_ip(mapper, ip);
2655 if (WARN_ON_ONCE(!edata))
2658 if (WARN_ON_ONCE(edata->ref <= 0))
2661 free_probe_data(edata);
2664 static struct ftrace_probe_ops event_enable_probe_ops = {
2665 .func = event_enable_probe,
2666 .print = event_enable_print,
2667 .init = event_enable_init,
2668 .free = event_enable_free,
2671 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2672 .func = event_enable_count_probe,
2673 .print = event_enable_print,
2674 .init = event_enable_init,
2675 .free = event_enable_free,
2678 static struct ftrace_probe_ops event_disable_probe_ops = {
2679 .func = event_enable_probe,
2680 .print = event_enable_print,
2681 .init = event_enable_init,
2682 .free = event_enable_free,
2685 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2686 .func = event_enable_count_probe,
2687 .print = event_enable_print,
2688 .init = event_enable_init,
2689 .free = event_enable_free,
2693 event_enable_func(struct trace_array *tr, struct ftrace_hash *hash,
2694 char *glob, char *cmd, char *param, int enabled)
2696 struct trace_event_file *file;
2697 struct ftrace_probe_ops *ops;
2698 struct event_probe_data *data;
2708 /* hash funcs only work with set_ftrace_filter */
2709 if (!enabled || !param)
2712 system = strsep(¶m, ":");
2716 event = strsep(¶m, ":");
2718 mutex_lock(&event_mutex);
2721 file = find_event_file(tr, system, event);
2725 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2728 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2730 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2732 if (glob[0] == '!') {
2733 ret = unregister_ftrace_function_probe_func(glob+1, tr, ops);
2739 data = kzalloc(sizeof(*data), GFP_KERNEL);
2743 data->enable = enable;
2750 number = strsep(¶m, ":");
2753 if (!strlen(number))
2757 * We use the callback data field (which is a pointer)
2760 ret = kstrtoul(number, 0, &data->count);
2765 /* Don't let event modules unload while probe registered */
2766 ret = try_module_get(file->event_call->mod);
2772 ret = __ftrace_event_enable_disable(file, 1, 1);
2776 ret = register_ftrace_function_probe(glob, tr, ops, data);
2778 * The above returns on success the # of functions enabled,
2779 * but if it didn't find any functions it returns zero.
2780 * Consider no functions a failure too.
2787 /* Just return zero, not the number of enabled functions */
2790 mutex_unlock(&event_mutex);
2794 __ftrace_event_enable_disable(file, 0, 1);
2796 module_put(file->event_call->mod);
2802 static struct ftrace_func_command event_enable_cmd = {
2803 .name = ENABLE_EVENT_STR,
2804 .func = event_enable_func,
2807 static struct ftrace_func_command event_disable_cmd = {
2808 .name = DISABLE_EVENT_STR,
2809 .func = event_enable_func,
2812 static __init int register_event_cmds(void)
2816 ret = register_ftrace_command(&event_enable_cmd);
2817 if (WARN_ON(ret < 0))
2819 ret = register_ftrace_command(&event_disable_cmd);
2820 if (WARN_ON(ret < 0))
2821 unregister_ftrace_command(&event_enable_cmd);
2825 static inline int register_event_cmds(void) { return 0; }
2826 #endif /* CONFIG_DYNAMIC_FTRACE */
2829 * The top level array has already had its trace_event_file
2830 * descriptors created in order to allow for early events to
2831 * be recorded. This function is called after the tracefs has been
2832 * initialized, and we now have to create the files associated
2836 __trace_early_add_event_dirs(struct trace_array *tr)
2838 struct trace_event_file *file;
2842 list_for_each_entry(file, &tr->events, list) {
2843 ret = event_create_dir(tr->event_dir, file);
2845 pr_warn("Could not create directory for event %s\n",
2846 trace_event_name(file->event_call));
2851 * For early boot up, the top trace array requires to have
2852 * a list of events that can be enabled. This must be done before
2853 * the filesystem is set up in order to allow events to be traced
2857 __trace_early_add_events(struct trace_array *tr)
2859 struct trace_event_call *call;
2862 list_for_each_entry(call, &ftrace_events, list) {
2863 /* Early boot up should not have any modules loaded */
2864 if (WARN_ON_ONCE(call->mod))
2867 ret = __trace_early_add_new_event(call, tr);
2869 pr_warn("Could not create early event %s\n",
2870 trace_event_name(call));
2874 /* Remove the event directory structure for a trace directory. */
2876 __trace_remove_event_dirs(struct trace_array *tr)
2878 struct trace_event_file *file, *next;
2880 list_for_each_entry_safe(file, next, &tr->events, list)
2881 remove_event_file_dir(file);
2884 static void __add_event_to_tracers(struct trace_event_call *call)
2886 struct trace_array *tr;
2888 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2889 __trace_add_new_event(call, tr);
2892 extern struct trace_event_call *__start_ftrace_events[];
2893 extern struct trace_event_call *__stop_ftrace_events[];
2895 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2897 static __init int setup_trace_event(char *str)
2899 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2900 ring_buffer_expanded = true;
2901 tracing_selftest_disabled = true;
2905 __setup("trace_event=", setup_trace_event);
2907 /* Expects to have event_mutex held when called */
2909 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2911 struct dentry *d_events;
2912 struct dentry *entry;
2914 entry = tracefs_create_file("set_event", 0644, parent,
2915 tr, &ftrace_set_event_fops);
2917 pr_warn("Could not create tracefs 'set_event' entry\n");
2921 d_events = tracefs_create_dir("events", parent);
2923 pr_warn("Could not create tracefs 'events' directory\n");
2927 entry = trace_create_file("enable", 0644, d_events,
2928 tr, &ftrace_tr_enable_fops);
2930 pr_warn("Could not create tracefs 'enable' entry\n");
2934 /* There are not as crucial, just warn if they are not created */
2936 entry = tracefs_create_file("set_event_pid", 0644, parent,
2937 tr, &ftrace_set_event_pid_fops);
2939 pr_warn("Could not create tracefs 'set_event_pid' entry\n");
2941 /* ring buffer internal formats */
2942 entry = trace_create_file("header_page", 0444, d_events,
2943 ring_buffer_print_page_header,
2944 &ftrace_show_header_fops);
2946 pr_warn("Could not create tracefs 'header_page' entry\n");
2948 entry = trace_create_file("header_event", 0444, d_events,
2949 ring_buffer_print_entry_header,
2950 &ftrace_show_header_fops);
2952 pr_warn("Could not create tracefs 'header_event' entry\n");
2954 tr->event_dir = d_events;
2960 * event_trace_add_tracer - add a instance of a trace_array to events
2961 * @parent: The parent dentry to place the files/directories for events in
2962 * @tr: The trace array associated with these events
2964 * When a new instance is created, it needs to set up its events
2965 * directory, as well as other files associated with events. It also
2966 * creates the event hierachry in the @parent/events directory.
2968 * Returns 0 on success.
2970 * Must be called with event_mutex held.
2972 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2976 lockdep_assert_held(&event_mutex);
2978 ret = create_event_toplevel_files(parent, tr);
2982 down_write(&trace_event_sem);
2983 __trace_add_event_dirs(tr);
2984 up_write(&trace_event_sem);
2991 * The top trace array already had its file descriptors created.
2992 * Now the files themselves need to be created.
2995 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2999 mutex_lock(&event_mutex);
3001 ret = create_event_toplevel_files(parent, tr);
3005 down_write(&trace_event_sem);
3006 __trace_early_add_event_dirs(tr);
3007 up_write(&trace_event_sem);
3010 mutex_unlock(&event_mutex);
3015 /* Must be called with event_mutex held */
3016 int event_trace_del_tracer(struct trace_array *tr)
3018 lockdep_assert_held(&event_mutex);
3020 /* Disable any event triggers and associated soft-disabled events */
3021 clear_event_triggers(tr);
3023 /* Clear the pid list */
3024 __ftrace_clear_event_pids(tr);
3026 /* Disable any running events */
3027 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3029 /* Make sure no more events are being executed */
3030 tracepoint_synchronize_unregister();
3032 down_write(&trace_event_sem);
3033 __trace_remove_event_dirs(tr);
3034 tracefs_remove_recursive(tr->event_dir);
3035 up_write(&trace_event_sem);
3037 tr->event_dir = NULL;
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 __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 #ifdef CONFIG_EVENT_TRACE_STARTUP_TEST
3186 static DEFINE_SPINLOCK(test_spinlock);
3187 static DEFINE_SPINLOCK(test_spinlock_irq);
3188 static DEFINE_MUTEX(test_mutex);
3190 static __init void test_work(struct work_struct *dummy)
3192 spin_lock(&test_spinlock);
3193 spin_lock_irq(&test_spinlock_irq);
3195 spin_unlock_irq(&test_spinlock_irq);
3196 spin_unlock(&test_spinlock);
3198 mutex_lock(&test_mutex);
3200 mutex_unlock(&test_mutex);
3203 static __init int event_test_thread(void *unused)
3207 test_malloc = kmalloc(1234, GFP_KERNEL);
3209 pr_info("failed to kmalloc\n");
3211 schedule_on_each_cpu(test_work);
3215 set_current_state(TASK_INTERRUPTIBLE);
3216 while (!kthread_should_stop()) {
3218 set_current_state(TASK_INTERRUPTIBLE);
3220 __set_current_state(TASK_RUNNING);
3226 * Do various things that may trigger events.
3228 static __init void event_test_stuff(void)
3230 struct task_struct *test_thread;
3232 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3234 kthread_stop(test_thread);
3238 * For every trace event defined, we will test each trace point separately,
3239 * and then by groups, and finally all trace points.
3241 static __init void event_trace_self_tests(void)
3243 struct trace_subsystem_dir *dir;
3244 struct trace_event_file *file;
3245 struct trace_event_call *call;
3246 struct event_subsystem *system;
3247 struct trace_array *tr;
3250 tr = top_trace_array();
3254 pr_info("Running tests on trace events:\n");
3256 list_for_each_entry(file, &tr->events, list) {
3258 call = file->event_call;
3260 /* Only test those that have a probe */
3261 if (!call->class || !call->class->probe)
3265 * Testing syscall events here is pretty useless, but
3266 * we still do it if configured. But this is time consuming.
3267 * What we really need is a user thread to perform the
3268 * syscalls as we test.
3270 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3271 if (call->class->system &&
3272 strcmp(call->class->system, "syscalls") == 0)
3276 pr_info("Testing event %s: ", trace_event_name(call));
3279 * If an event is already enabled, someone is using
3280 * it and the self test should not be on.
3282 if (file->flags & EVENT_FILE_FL_ENABLED) {
3283 pr_warn("Enabled event during self test!\n");
3288 ftrace_event_enable_disable(file, 1);
3290 ftrace_event_enable_disable(file, 0);
3295 /* Now test at the sub system level */
3297 pr_info("Running tests on trace event systems:\n");
3299 list_for_each_entry(dir, &tr->systems, list) {
3301 system = dir->subsystem;
3303 /* the ftrace system is special, skip it */
3304 if (strcmp(system->name, "ftrace") == 0)
3307 pr_info("Testing event system %s: ", system->name);
3309 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3310 if (WARN_ON_ONCE(ret)) {
3311 pr_warn("error enabling system %s\n",
3318 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3319 if (WARN_ON_ONCE(ret)) {
3320 pr_warn("error disabling system %s\n",
3328 /* Test with all events enabled */
3330 pr_info("Running tests on all trace events:\n");
3331 pr_info("Testing all events: ");
3333 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3334 if (WARN_ON_ONCE(ret)) {
3335 pr_warn("error enabling all events\n");
3342 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3343 if (WARN_ON_ONCE(ret)) {
3344 pr_warn("error disabling all events\n");
3351 #ifdef CONFIG_FUNCTION_TRACER
3353 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3355 static struct trace_event_file event_trace_file __initdata;
3358 function_test_events_call(unsigned long ip, unsigned long parent_ip,
3359 struct ftrace_ops *op, struct pt_regs *pt_regs)
3361 struct ring_buffer_event *event;
3362 struct ring_buffer *buffer;
3363 struct ftrace_entry *entry;
3364 unsigned long flags;
3369 pc = preempt_count();
3370 preempt_disable_notrace();
3371 cpu = raw_smp_processor_id();
3372 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3377 local_save_flags(flags);
3379 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
3380 TRACE_FN, sizeof(*entry),
3384 entry = ring_buffer_event_data(event);
3386 entry->parent_ip = parent_ip;
3388 event_trigger_unlock_commit(&event_trace_file, buffer, event,
3391 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3392 preempt_enable_notrace();
3395 static struct ftrace_ops trace_ops __initdata =
3397 .func = function_test_events_call,
3398 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
3401 static __init void event_trace_self_test_with_function(void)
3405 event_trace_file.tr = top_trace_array();
3406 if (WARN_ON(!event_trace_file.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);