4 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
6 * - Added format output of fields of the trace point.
7 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
11 #define pr_fmt(fmt) fmt
13 #include <linux/workqueue.h>
14 #include <linux/spinlock.h>
15 #include <linux/kthread.h>
16 #include <linux/tracefs.h>
17 #include <linux/uaccess.h>
18 #include <linux/bsearch.h>
19 #include <linux/module.h>
20 #include <linux/ctype.h>
21 #include <linux/sort.h>
22 #include <linux/slab.h>
23 #include <linux/delay.h>
25 #include <trace/events/sched.h>
27 #include <asm/setup.h>
29 #include "trace_output.h"
32 #define TRACE_SYSTEM "TRACE_SYSTEM"
34 DEFINE_MUTEX(event_mutex
);
36 LIST_HEAD(ftrace_events
);
37 static LIST_HEAD(ftrace_generic_fields
);
38 static LIST_HEAD(ftrace_common_fields
);
40 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
42 static struct kmem_cache
*field_cachep
;
43 static struct kmem_cache
*file_cachep
;
45 static inline int system_refcount(struct event_subsystem
*system
)
47 return system
->ref_count
;
50 static int system_refcount_inc(struct event_subsystem
*system
)
52 return system
->ref_count
++;
55 static int system_refcount_dec(struct event_subsystem
*system
)
57 return --system
->ref_count
;
60 /* Double loops, do not use break, only goto's work */
61 #define do_for_each_event_file(tr, file) \
62 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
63 list_for_each_entry(file, &tr->events, list)
65 #define do_for_each_event_file_safe(tr, file) \
66 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
67 struct trace_event_file *___n; \
68 list_for_each_entry_safe(file, ___n, &tr->events, list)
70 #define while_for_each_event_file() \
73 static struct list_head
*
74 trace_get_fields(struct trace_event_call
*event_call
)
76 if (!event_call
->class->get_fields
)
77 return &event_call
->class->fields
;
78 return event_call
->class->get_fields(event_call
);
81 static struct ftrace_event_field
*
82 __find_event_field(struct list_head
*head
, char *name
)
84 struct ftrace_event_field
*field
;
86 list_for_each_entry(field
, head
, link
) {
87 if (!strcmp(field
->name
, name
))
94 struct ftrace_event_field
*
95 trace_find_event_field(struct trace_event_call
*call
, char *name
)
97 struct ftrace_event_field
*field
;
98 struct list_head
*head
;
100 field
= __find_event_field(&ftrace_generic_fields
, name
);
104 field
= __find_event_field(&ftrace_common_fields
, name
);
108 head
= trace_get_fields(call
);
109 return __find_event_field(head
, name
);
112 static int __trace_define_field(struct list_head
*head
, const char *type
,
113 const char *name
, int offset
, int size
,
114 int is_signed
, int filter_type
)
116 struct ftrace_event_field
*field
;
118 field
= kmem_cache_alloc(field_cachep
, GFP_TRACE
);
125 if (filter_type
== FILTER_OTHER
)
126 field
->filter_type
= filter_assign_type(type
);
128 field
->filter_type
= filter_type
;
130 field
->offset
= offset
;
132 field
->is_signed
= is_signed
;
134 list_add(&field
->link
, head
);
139 int trace_define_field(struct trace_event_call
*call
, const char *type
,
140 const char *name
, int offset
, int size
, int is_signed
,
143 struct list_head
*head
;
145 if (WARN_ON(!call
->class))
148 head
= trace_get_fields(call
);
149 return __trace_define_field(head
, type
, name
, offset
, size
,
150 is_signed
, filter_type
);
152 EXPORT_SYMBOL_GPL(trace_define_field
);
154 #define __generic_field(type, item, filter_type) \
155 ret = __trace_define_field(&ftrace_generic_fields, #type, \
156 #item, 0, 0, is_signed_type(type), \
161 #define __common_field(type, item) \
162 ret = __trace_define_field(&ftrace_common_fields, #type, \
164 offsetof(typeof(ent), item), \
166 is_signed_type(type), FILTER_OTHER); \
170 static int trace_define_generic_fields(void)
174 __generic_field(int, cpu
, FILTER_OTHER
);
175 __generic_field(char *, comm
, FILTER_PTR_STRING
);
180 static int trace_define_common_fields(void)
183 struct trace_entry ent
;
185 __common_field(unsigned short, type
);
186 __common_field(unsigned char, flags
);
187 __common_field(unsigned char, preempt_count
);
188 __common_field(int, pid
);
193 static void trace_destroy_fields(struct trace_event_call
*call
)
195 struct ftrace_event_field
*field
, *next
;
196 struct list_head
*head
;
198 head
= trace_get_fields(call
);
199 list_for_each_entry_safe(field
, next
, head
, link
) {
200 list_del(&field
->link
);
201 kmem_cache_free(field_cachep
, field
);
205 int trace_event_raw_init(struct trace_event_call
*call
)
209 id
= register_trace_event(&call
->event
);
215 EXPORT_SYMBOL_GPL(trace_event_raw_init
);
217 bool trace_event_ignore_this_pid(struct trace_event_file
*trace_file
)
219 struct trace_array
*tr
= trace_file
->tr
;
220 struct trace_array_cpu
*data
;
221 struct trace_pid_list
*pid_list
;
223 pid_list
= rcu_dereference_sched(tr
->filtered_pids
);
227 data
= this_cpu_ptr(tr
->trace_buffer
.data
);
229 return data
->ignore_pid
;
231 EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid
);
233 void *trace_event_buffer_reserve(struct trace_event_buffer
*fbuffer
,
234 struct trace_event_file
*trace_file
,
237 struct trace_event_call
*event_call
= trace_file
->event_call
;
239 if ((trace_file
->flags
& EVENT_FILE_FL_PID_FILTER
) &&
240 trace_event_ignore_this_pid(trace_file
))
243 local_save_flags(fbuffer
->flags
);
244 fbuffer
->pc
= preempt_count();
245 fbuffer
->trace_file
= trace_file
;
248 trace_event_buffer_lock_reserve(&fbuffer
->buffer
, trace_file
,
249 event_call
->event
.type
, len
,
250 fbuffer
->flags
, fbuffer
->pc
);
254 fbuffer
->entry
= ring_buffer_event_data(fbuffer
->event
);
255 return fbuffer
->entry
;
257 EXPORT_SYMBOL_GPL(trace_event_buffer_reserve
);
259 static DEFINE_SPINLOCK(tracepoint_iter_lock
);
261 static void output_printk(struct trace_event_buffer
*fbuffer
)
263 struct trace_event_call
*event_call
;
264 struct trace_event
*event
;
266 struct trace_iterator
*iter
= tracepoint_print_iter
;
271 event_call
= fbuffer
->trace_file
->event_call
;
272 if (!event_call
|| !event_call
->event
.funcs
||
273 !event_call
->event
.funcs
->trace
)
276 event
= &fbuffer
->trace_file
->event_call
->event
;
278 spin_lock_irqsave(&tracepoint_iter_lock
, flags
);
279 trace_seq_init(&iter
->seq
);
280 iter
->ent
= fbuffer
->entry
;
281 event_call
->event
.funcs
->trace(iter
, 0, event
);
282 trace_seq_putc(&iter
->seq
, 0);
283 printk("%s", iter
->seq
.buffer
);
285 spin_unlock_irqrestore(&tracepoint_iter_lock
, flags
);
288 void trace_event_buffer_commit(struct trace_event_buffer
*fbuffer
)
290 if (tracepoint_printk
)
291 output_printk(fbuffer
);
293 event_trigger_unlock_commit(fbuffer
->trace_file
, fbuffer
->buffer
,
294 fbuffer
->event
, fbuffer
->entry
,
295 fbuffer
->flags
, fbuffer
->pc
);
297 EXPORT_SYMBOL_GPL(trace_event_buffer_commit
);
299 int trace_event_reg(struct trace_event_call
*call
,
300 enum trace_reg type
, void *data
)
302 struct trace_event_file
*file
= data
;
304 WARN_ON(!(call
->flags
& TRACE_EVENT_FL_TRACEPOINT
));
306 case TRACE_REG_REGISTER
:
307 return tracepoint_probe_register(call
->tp
,
310 case TRACE_REG_UNREGISTER
:
311 tracepoint_probe_unregister(call
->tp
,
316 #ifdef CONFIG_PERF_EVENTS
317 case TRACE_REG_PERF_REGISTER
:
318 return tracepoint_probe_register(call
->tp
,
319 call
->class->perf_probe
,
321 case TRACE_REG_PERF_UNREGISTER
:
322 tracepoint_probe_unregister(call
->tp
,
323 call
->class->perf_probe
,
326 case TRACE_REG_PERF_OPEN
:
327 case TRACE_REG_PERF_CLOSE
:
328 case TRACE_REG_PERF_ADD
:
329 case TRACE_REG_PERF_DEL
:
335 EXPORT_SYMBOL_GPL(trace_event_reg
);
337 void trace_event_enable_cmd_record(bool enable
)
339 struct trace_event_file
*file
;
340 struct trace_array
*tr
;
342 mutex_lock(&event_mutex
);
343 do_for_each_event_file(tr
, file
) {
345 if (!(file
->flags
& EVENT_FILE_FL_ENABLED
))
349 tracing_start_cmdline_record();
350 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT
, &file
->flags
);
352 tracing_stop_cmdline_record();
353 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT
, &file
->flags
);
355 } while_for_each_event_file();
356 mutex_unlock(&event_mutex
);
359 static int __ftrace_event_enable_disable(struct trace_event_file
*file
,
360 int enable
, int soft_disable
)
362 struct trace_event_call
*call
= file
->event_call
;
363 struct trace_array
*tr
= file
->tr
;
370 * When soft_disable is set and enable is cleared, the sm_ref
371 * reference counter is decremented. If it reaches 0, we want
372 * to clear the SOFT_DISABLED flag but leave the event in the
373 * state that it was. That is, if the event was enabled and
374 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
375 * is set we do not want the event to be enabled before we
378 * When soft_disable is not set but the SOFT_MODE flag is,
379 * we do nothing. Do not disable the tracepoint, otherwise
380 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
383 if (atomic_dec_return(&file
->sm_ref
) > 0)
385 disable
= file
->flags
& EVENT_FILE_FL_SOFT_DISABLED
;
386 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT
, &file
->flags
);
388 disable
= !(file
->flags
& EVENT_FILE_FL_SOFT_MODE
);
390 if (disable
&& (file
->flags
& EVENT_FILE_FL_ENABLED
)) {
391 clear_bit(EVENT_FILE_FL_ENABLED_BIT
, &file
->flags
);
392 if (file
->flags
& EVENT_FILE_FL_RECORDED_CMD
) {
393 tracing_stop_cmdline_record();
394 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT
, &file
->flags
);
396 call
->class->reg(call
, TRACE_REG_UNREGISTER
, file
);
398 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
399 if (file
->flags
& EVENT_FILE_FL_SOFT_MODE
)
400 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT
, &file
->flags
);
402 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT
, &file
->flags
);
406 * When soft_disable is set and enable is set, we want to
407 * register the tracepoint for the event, but leave the event
408 * as is. That means, if the event was already enabled, we do
409 * nothing (but set SOFT_MODE). If the event is disabled, we
410 * set SOFT_DISABLED before enabling the event tracepoint, so
411 * it still seems to be disabled.
414 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT
, &file
->flags
);
416 if (atomic_inc_return(&file
->sm_ref
) > 1)
418 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT
, &file
->flags
);
421 if (!(file
->flags
& EVENT_FILE_FL_ENABLED
)) {
423 /* Keep the event disabled, when going to SOFT_MODE. */
425 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT
, &file
->flags
);
427 if (tr
->trace_flags
& TRACE_ITER_RECORD_CMD
) {
428 tracing_start_cmdline_record();
429 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT
, &file
->flags
);
431 ret
= call
->class->reg(call
, TRACE_REG_REGISTER
, file
);
433 tracing_stop_cmdline_record();
434 pr_info("event trace: Could not enable event "
435 "%s\n", trace_event_name(call
));
438 set_bit(EVENT_FILE_FL_ENABLED_BIT
, &file
->flags
);
440 /* WAS_ENABLED gets set but never cleared. */
441 call
->flags
|= TRACE_EVENT_FL_WAS_ENABLED
;
449 int trace_event_enable_disable(struct trace_event_file
*file
,
450 int enable
, int soft_disable
)
452 return __ftrace_event_enable_disable(file
, enable
, soft_disable
);
455 static int ftrace_event_enable_disable(struct trace_event_file
*file
,
458 return __ftrace_event_enable_disable(file
, enable
, 0);
461 static void ftrace_clear_events(struct trace_array
*tr
)
463 struct trace_event_file
*file
;
465 mutex_lock(&event_mutex
);
466 list_for_each_entry(file
, &tr
->events
, list
) {
467 ftrace_event_enable_disable(file
, 0);
469 mutex_unlock(&event_mutex
);
472 static int cmp_pid(const void *key
, const void *elt
)
474 const pid_t
*search_pid
= key
;
475 const pid_t
*pid
= elt
;
477 if (*search_pid
== *pid
)
479 if (*search_pid
< *pid
)
485 check_ignore_pid(struct trace_pid_list
*filtered_pids
, struct task_struct
*task
)
491 * Return false, because if filtered_pids does not exist,
492 * all pids are good to trace.
497 search_pid
= task
->pid
;
499 pid
= bsearch(&search_pid
, filtered_pids
->pids
,
500 filtered_pids
->nr_pids
, sizeof(pid_t
),
509 event_filter_pid_sched_switch_probe_pre(void *data
, bool preempt
,
510 struct task_struct
*prev
, struct task_struct
*next
)
512 struct trace_array
*tr
= data
;
513 struct trace_pid_list
*pid_list
;
515 pid_list
= rcu_dereference_sched(tr
->filtered_pids
);
517 this_cpu_write(tr
->trace_buffer
.data
->ignore_pid
,
518 check_ignore_pid(pid_list
, prev
) &&
519 check_ignore_pid(pid_list
, next
));
523 event_filter_pid_sched_switch_probe_post(void *data
, bool preempt
,
524 struct task_struct
*prev
, struct task_struct
*next
)
526 struct trace_array
*tr
= data
;
527 struct trace_pid_list
*pid_list
;
529 pid_list
= rcu_dereference_sched(tr
->filtered_pids
);
531 this_cpu_write(tr
->trace_buffer
.data
->ignore_pid
,
532 check_ignore_pid(pid_list
, next
));
536 event_filter_pid_sched_wakeup_probe_pre(void *data
, struct task_struct
*task
)
538 struct trace_array
*tr
= data
;
539 struct trace_pid_list
*pid_list
;
541 /* Nothing to do if we are already tracing */
542 if (!this_cpu_read(tr
->trace_buffer
.data
->ignore_pid
))
545 pid_list
= rcu_dereference_sched(tr
->filtered_pids
);
547 this_cpu_write(tr
->trace_buffer
.data
->ignore_pid
,
548 check_ignore_pid(pid_list
, task
));
552 event_filter_pid_sched_wakeup_probe_post(void *data
, struct task_struct
*task
)
554 struct trace_array
*tr
= data
;
555 struct trace_pid_list
*pid_list
;
557 /* Nothing to do if we are not tracing */
558 if (this_cpu_read(tr
->trace_buffer
.data
->ignore_pid
))
561 pid_list
= rcu_dereference_sched(tr
->filtered_pids
);
563 /* Set tracing if current is enabled */
564 this_cpu_write(tr
->trace_buffer
.data
->ignore_pid
,
565 check_ignore_pid(pid_list
, current
));
568 static void __ftrace_clear_event_pids(struct trace_array
*tr
)
570 struct trace_pid_list
*pid_list
;
571 struct trace_event_file
*file
;
574 pid_list
= rcu_dereference_protected(tr
->filtered_pids
,
575 lockdep_is_held(&event_mutex
));
579 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre
, tr
);
580 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post
, tr
);
582 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre
, tr
);
583 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post
, tr
);
585 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre
, tr
);
586 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post
, tr
);
588 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre
, tr
);
589 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post
, tr
);
591 list_for_each_entry(file
, &tr
->events
, list
) {
592 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT
, &file
->flags
);
595 for_each_possible_cpu(cpu
)
596 per_cpu_ptr(tr
->trace_buffer
.data
, cpu
)->ignore_pid
= false;
598 rcu_assign_pointer(tr
->filtered_pids
, NULL
);
600 /* Wait till all users are no longer using pid filtering */
603 free_pages((unsigned long)pid_list
->pids
, pid_list
->order
);
607 static void ftrace_clear_event_pids(struct trace_array
*tr
)
609 mutex_lock(&event_mutex
);
610 __ftrace_clear_event_pids(tr
);
611 mutex_unlock(&event_mutex
);
614 static void __put_system(struct event_subsystem
*system
)
616 struct event_filter
*filter
= system
->filter
;
618 WARN_ON_ONCE(system_refcount(system
) == 0);
619 if (system_refcount_dec(system
))
622 list_del(&system
->list
);
625 kfree(filter
->filter_string
);
628 kfree_const(system
->name
);
632 static void __get_system(struct event_subsystem
*system
)
634 WARN_ON_ONCE(system_refcount(system
) == 0);
635 system_refcount_inc(system
);
638 static void __get_system_dir(struct trace_subsystem_dir
*dir
)
640 WARN_ON_ONCE(dir
->ref_count
== 0);
642 __get_system(dir
->subsystem
);
645 static void __put_system_dir(struct trace_subsystem_dir
*dir
)
647 WARN_ON_ONCE(dir
->ref_count
== 0);
648 /* If the subsystem is about to be freed, the dir must be too */
649 WARN_ON_ONCE(system_refcount(dir
->subsystem
) == 1 && dir
->ref_count
!= 1);
651 __put_system(dir
->subsystem
);
652 if (!--dir
->ref_count
)
656 static void put_system(struct trace_subsystem_dir
*dir
)
658 mutex_lock(&event_mutex
);
659 __put_system_dir(dir
);
660 mutex_unlock(&event_mutex
);
663 static void remove_subsystem(struct trace_subsystem_dir
*dir
)
668 if (!--dir
->nr_events
) {
669 tracefs_remove_recursive(dir
->entry
);
670 list_del(&dir
->list
);
671 __put_system_dir(dir
);
675 static void remove_event_file_dir(struct trace_event_file
*file
)
677 struct dentry
*dir
= file
->dir
;
678 struct dentry
*child
;
681 spin_lock(&dir
->d_lock
); /* probably unneeded */
682 list_for_each_entry(child
, &dir
->d_subdirs
, d_child
) {
683 if (d_really_is_positive(child
)) /* probably unneeded */
684 d_inode(child
)->i_private
= NULL
;
686 spin_unlock(&dir
->d_lock
);
688 tracefs_remove_recursive(dir
);
691 list_del(&file
->list
);
692 remove_subsystem(file
->system
);
693 free_event_filter(file
->filter
);
694 kmem_cache_free(file_cachep
, file
);
698 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
701 __ftrace_set_clr_event_nolock(struct trace_array
*tr
, const char *match
,
702 const char *sub
, const char *event
, int set
)
704 struct trace_event_file
*file
;
705 struct trace_event_call
*call
;
709 list_for_each_entry(file
, &tr
->events
, list
) {
711 call
= file
->event_call
;
712 name
= trace_event_name(call
);
714 if (!name
|| !call
->class || !call
->class->reg
)
717 if (call
->flags
& TRACE_EVENT_FL_IGNORE_ENABLE
)
721 strcmp(match
, name
) != 0 &&
722 strcmp(match
, call
->class->system
) != 0)
725 if (sub
&& strcmp(sub
, call
->class->system
) != 0)
728 if (event
&& strcmp(event
, name
) != 0)
731 ftrace_event_enable_disable(file
, set
);
739 static int __ftrace_set_clr_event(struct trace_array
*tr
, const char *match
,
740 const char *sub
, const char *event
, int set
)
744 mutex_lock(&event_mutex
);
745 ret
= __ftrace_set_clr_event_nolock(tr
, match
, sub
, event
, set
);
746 mutex_unlock(&event_mutex
);
751 static int ftrace_set_clr_event(struct trace_array
*tr
, char *buf
, int set
)
753 char *event
= NULL
, *sub
= NULL
, *match
;
757 * The buf format can be <subsystem>:<event-name>
758 * *:<event-name> means any event by that name.
759 * :<event-name> is the same.
761 * <subsystem>:* means all events in that subsystem
762 * <subsystem>: means the same.
764 * <name> (no ':') means all events in a subsystem with
765 * the name <name> or any event that matches <name>
768 match
= strsep(&buf
, ":");
774 if (!strlen(sub
) || strcmp(sub
, "*") == 0)
776 if (!strlen(event
) || strcmp(event
, "*") == 0)
780 ret
= __ftrace_set_clr_event(tr
, match
, sub
, event
, set
);
782 /* Put back the colon to allow this to be called again */
790 * trace_set_clr_event - enable or disable an event
791 * @system: system name to match (NULL for any system)
792 * @event: event name to match (NULL for all events, within system)
793 * @set: 1 to enable, 0 to disable
795 * This is a way for other parts of the kernel to enable or disable
798 * Returns 0 on success, -EINVAL if the parameters do not match any
801 int trace_set_clr_event(const char *system
, const char *event
, int set
)
803 struct trace_array
*tr
= top_trace_array();
808 return __ftrace_set_clr_event(tr
, NULL
, system
, event
, set
);
810 EXPORT_SYMBOL_GPL(trace_set_clr_event
);
812 /* 128 should be much more than enough */
813 #define EVENT_BUF_SIZE 127
816 ftrace_event_write(struct file
*file
, const char __user
*ubuf
,
817 size_t cnt
, loff_t
*ppos
)
819 struct trace_parser parser
;
820 struct seq_file
*m
= file
->private_data
;
821 struct trace_array
*tr
= m
->private;
827 ret
= tracing_update_buffers();
831 if (trace_parser_get_init(&parser
, EVENT_BUF_SIZE
+ 1))
834 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
836 if (read
>= 0 && trace_parser_loaded((&parser
))) {
839 if (*parser
.buffer
== '!')
842 parser
.buffer
[parser
.idx
] = 0;
844 ret
= ftrace_set_clr_event(tr
, parser
.buffer
+ !set
, set
);
852 trace_parser_put(&parser
);
858 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
860 struct trace_event_file
*file
= v
;
861 struct trace_event_call
*call
;
862 struct trace_array
*tr
= m
->private;
866 list_for_each_entry_continue(file
, &tr
->events
, list
) {
867 call
= file
->event_call
;
869 * The ftrace subsystem is for showing formats only.
870 * They can not be enabled or disabled via the event files.
872 if (call
->class && call
->class->reg
&&
873 !(call
->flags
& TRACE_EVENT_FL_IGNORE_ENABLE
))
880 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
882 struct trace_event_file
*file
;
883 struct trace_array
*tr
= m
->private;
886 mutex_lock(&event_mutex
);
888 file
= list_entry(&tr
->events
, struct trace_event_file
, list
);
889 for (l
= 0; l
<= *pos
; ) {
890 file
= t_next(m
, file
, &l
);
898 s_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
900 struct trace_event_file
*file
= v
;
901 struct trace_array
*tr
= m
->private;
905 list_for_each_entry_continue(file
, &tr
->events
, list
) {
906 if (file
->flags
& EVENT_FILE_FL_ENABLED
)
913 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
915 struct trace_event_file
*file
;
916 struct trace_array
*tr
= m
->private;
919 mutex_lock(&event_mutex
);
921 file
= list_entry(&tr
->events
, struct trace_event_file
, list
);
922 for (l
= 0; l
<= *pos
; ) {
923 file
= s_next(m
, file
, &l
);
930 static int t_show(struct seq_file
*m
, void *v
)
932 struct trace_event_file
*file
= v
;
933 struct trace_event_call
*call
= file
->event_call
;
935 if (strcmp(call
->class->system
, TRACE_SYSTEM
) != 0)
936 seq_printf(m
, "%s:", call
->class->system
);
937 seq_printf(m
, "%s\n", trace_event_name(call
));
942 static void t_stop(struct seq_file
*m
, void *p
)
944 mutex_unlock(&event_mutex
);
947 static void *p_start(struct seq_file
*m
, loff_t
*pos
)
950 struct trace_pid_list
*pid_list
;
951 struct trace_array
*tr
= m
->private;
954 * Grab the mutex, to keep calls to p_next() having the same
955 * tr->filtered_pids as p_start() has.
956 * If we just passed the tr->filtered_pids around, then RCU would
957 * have been enough, but doing that makes things more complex.
959 mutex_lock(&event_mutex
);
960 rcu_read_lock_sched();
962 pid_list
= rcu_dereference_sched(tr
->filtered_pids
);
964 if (!pid_list
|| *pos
>= pid_list
->nr_pids
)
967 return (void *)&pid_list
->pids
[*pos
];
970 static void p_stop(struct seq_file
*m
, void *p
)
973 rcu_read_unlock_sched();
974 mutex_unlock(&event_mutex
);
978 p_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
980 struct trace_array
*tr
= m
->private;
981 struct trace_pid_list
*pid_list
= rcu_dereference_sched(tr
->filtered_pids
);
985 if (*pos
>= pid_list
->nr_pids
)
988 return (void *)&pid_list
->pids
[*pos
];
991 static int p_show(struct seq_file
*m
, void *v
)
995 seq_printf(m
, "%d\n", *pid
);
1000 event_enable_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
1003 struct trace_event_file
*file
;
1004 unsigned long flags
;
1007 mutex_lock(&event_mutex
);
1008 file
= event_file_data(filp
);
1010 flags
= file
->flags
;
1011 mutex_unlock(&event_mutex
);
1016 if (flags
& EVENT_FILE_FL_ENABLED
&&
1017 !(flags
& EVENT_FILE_FL_SOFT_DISABLED
))
1020 if (flags
& EVENT_FILE_FL_SOFT_DISABLED
||
1021 flags
& EVENT_FILE_FL_SOFT_MODE
)
1026 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, strlen(buf
));
1030 event_enable_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
1033 struct trace_event_file
*file
;
1037 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
1041 ret
= tracing_update_buffers();
1049 mutex_lock(&event_mutex
);
1050 file
= event_file_data(filp
);
1052 ret
= ftrace_event_enable_disable(file
, val
);
1053 mutex_unlock(&event_mutex
);
1062 return ret
? ret
: cnt
;
1066 system_enable_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
1069 const char set_to_char
[4] = { '?', '0', '1', 'X' };
1070 struct trace_subsystem_dir
*dir
= filp
->private_data
;
1071 struct event_subsystem
*system
= dir
->subsystem
;
1072 struct trace_event_call
*call
;
1073 struct trace_event_file
*file
;
1074 struct trace_array
*tr
= dir
->tr
;
1079 mutex_lock(&event_mutex
);
1080 list_for_each_entry(file
, &tr
->events
, list
) {
1081 call
= file
->event_call
;
1082 if (!trace_event_name(call
) || !call
->class || !call
->class->reg
)
1085 if (system
&& strcmp(call
->class->system
, system
->name
) != 0)
1089 * We need to find out if all the events are set
1090 * or if all events or cleared, or if we have
1093 set
|= (1 << !!(file
->flags
& EVENT_FILE_FL_ENABLED
));
1096 * If we have a mixture, no need to look further.
1101 mutex_unlock(&event_mutex
);
1103 buf
[0] = set_to_char
[set
];
1106 ret
= simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, 2);
1112 system_enable_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
1115 struct trace_subsystem_dir
*dir
= filp
->private_data
;
1116 struct event_subsystem
*system
= dir
->subsystem
;
1117 const char *name
= NULL
;
1121 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
1125 ret
= tracing_update_buffers();
1129 if (val
!= 0 && val
!= 1)
1133 * Opening of "enable" adds a ref count to system,
1134 * so the name is safe to use.
1137 name
= system
->name
;
1139 ret
= __ftrace_set_clr_event(dir
->tr
, NULL
, name
, NULL
, val
);
1153 FORMAT_FIELD_SEPERATOR
= 2,
1154 FORMAT_PRINTFMT
= 3,
1157 static void *f_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
1159 struct trace_event_call
*call
= event_file_data(m
->private);
1160 struct list_head
*common_head
= &ftrace_common_fields
;
1161 struct list_head
*head
= trace_get_fields(call
);
1162 struct list_head
*node
= v
;
1166 switch ((unsigned long)v
) {
1171 case FORMAT_FIELD_SEPERATOR
:
1175 case FORMAT_PRINTFMT
:
1181 if (node
== common_head
)
1182 return (void *)FORMAT_FIELD_SEPERATOR
;
1183 else if (node
== head
)
1184 return (void *)FORMAT_PRINTFMT
;
1189 static int f_show(struct seq_file
*m
, void *v
)
1191 struct trace_event_call
*call
= event_file_data(m
->private);
1192 struct ftrace_event_field
*field
;
1193 const char *array_descriptor
;
1195 switch ((unsigned long)v
) {
1197 seq_printf(m
, "name: %s\n", trace_event_name(call
));
1198 seq_printf(m
, "ID: %d\n", call
->event
.type
);
1199 seq_puts(m
, "format:\n");
1202 case FORMAT_FIELD_SEPERATOR
:
1206 case FORMAT_PRINTFMT
:
1207 seq_printf(m
, "\nprint fmt: %s\n",
1212 field
= list_entry(v
, struct ftrace_event_field
, link
);
1214 * Smartly shows the array type(except dynamic array).
1217 * If TYPE := TYPE[LEN], it is shown:
1218 * field:TYPE VAR[LEN]
1220 array_descriptor
= strchr(field
->type
, '[');
1222 if (!strncmp(field
->type
, "__data_loc", 10))
1223 array_descriptor
= NULL
;
1225 if (!array_descriptor
)
1226 seq_printf(m
, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1227 field
->type
, field
->name
, field
->offset
,
1228 field
->size
, !!field
->is_signed
);
1230 seq_printf(m
, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1231 (int)(array_descriptor
- field
->type
),
1232 field
->type
, field
->name
,
1233 array_descriptor
, field
->offset
,
1234 field
->size
, !!field
->is_signed
);
1239 static void *f_start(struct seq_file
*m
, loff_t
*pos
)
1241 void *p
= (void *)FORMAT_HEADER
;
1244 /* ->stop() is called even if ->start() fails */
1245 mutex_lock(&event_mutex
);
1246 if (!event_file_data(m
->private))
1247 return ERR_PTR(-ENODEV
);
1249 while (l
< *pos
&& p
)
1250 p
= f_next(m
, p
, &l
);
1255 static void f_stop(struct seq_file
*m
, void *p
)
1257 mutex_unlock(&event_mutex
);
1260 static const struct seq_operations trace_format_seq_ops
= {
1267 static int trace_format_open(struct inode
*inode
, struct file
*file
)
1272 ret
= seq_open(file
, &trace_format_seq_ops
);
1276 m
= file
->private_data
;
1283 event_id_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
, loff_t
*ppos
)
1285 int id
= (long)event_file_data(filp
);
1295 len
= sprintf(buf
, "%d\n", id
);
1297 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, len
);
1301 event_filter_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
1304 struct trace_event_file
*file
;
1305 struct trace_seq
*s
;
1311 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
1318 mutex_lock(&event_mutex
);
1319 file
= event_file_data(filp
);
1321 print_event_filter(file
, s
);
1322 mutex_unlock(&event_mutex
);
1325 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
,
1326 s
->buffer
, trace_seq_used(s
));
1334 event_filter_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
1337 struct trace_event_file
*file
;
1341 if (cnt
>= PAGE_SIZE
)
1344 buf
= memdup_user_nul(ubuf
, cnt
);
1346 return PTR_ERR(buf
);
1348 mutex_lock(&event_mutex
);
1349 file
= event_file_data(filp
);
1351 err
= apply_event_filter(file
, buf
);
1352 mutex_unlock(&event_mutex
);
1363 static LIST_HEAD(event_subsystems
);
1365 static int subsystem_open(struct inode
*inode
, struct file
*filp
)
1367 struct event_subsystem
*system
= NULL
;
1368 struct trace_subsystem_dir
*dir
= NULL
; /* Initialize for gcc */
1369 struct trace_array
*tr
;
1372 if (tracing_is_disabled())
1375 /* Make sure the system still exists */
1376 mutex_lock(&trace_types_lock
);
1377 mutex_lock(&event_mutex
);
1378 list_for_each_entry(tr
, &ftrace_trace_arrays
, list
) {
1379 list_for_each_entry(dir
, &tr
->systems
, list
) {
1380 if (dir
== inode
->i_private
) {
1381 /* Don't open systems with no events */
1382 if (dir
->nr_events
) {
1383 __get_system_dir(dir
);
1384 system
= dir
->subsystem
;
1391 mutex_unlock(&event_mutex
);
1392 mutex_unlock(&trace_types_lock
);
1397 /* Some versions of gcc think dir can be uninitialized here */
1400 /* Still need to increment the ref count of the system */
1401 if (trace_array_get(tr
) < 0) {
1406 ret
= tracing_open_generic(inode
, filp
);
1408 trace_array_put(tr
);
1415 static int system_tr_open(struct inode
*inode
, struct file
*filp
)
1417 struct trace_subsystem_dir
*dir
;
1418 struct trace_array
*tr
= inode
->i_private
;
1421 if (tracing_is_disabled())
1424 if (trace_array_get(tr
) < 0)
1427 /* Make a temporary dir that has no system but points to tr */
1428 dir
= kzalloc(sizeof(*dir
), GFP_KERNEL
);
1430 trace_array_put(tr
);
1436 ret
= tracing_open_generic(inode
, filp
);
1438 trace_array_put(tr
);
1443 filp
->private_data
= dir
;
1448 static int subsystem_release(struct inode
*inode
, struct file
*file
)
1450 struct trace_subsystem_dir
*dir
= file
->private_data
;
1452 trace_array_put(dir
->tr
);
1455 * If dir->subsystem is NULL, then this is a temporary
1456 * descriptor that was made for a trace_array to enable
1468 subsystem_filter_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
1471 struct trace_subsystem_dir
*dir
= filp
->private_data
;
1472 struct event_subsystem
*system
= dir
->subsystem
;
1473 struct trace_seq
*s
;
1479 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
1485 print_subsystem_event_filter(system
, s
);
1486 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
,
1487 s
->buffer
, trace_seq_used(s
));
1495 subsystem_filter_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
1498 struct trace_subsystem_dir
*dir
= filp
->private_data
;
1502 if (cnt
>= PAGE_SIZE
)
1505 buf
= memdup_user_nul(ubuf
, cnt
);
1507 return PTR_ERR(buf
);
1509 err
= apply_subsystem_event_filter(dir
, buf
);
1520 show_header(struct file
*filp
, char __user
*ubuf
, size_t cnt
, loff_t
*ppos
)
1522 int (*func
)(struct trace_seq
*s
) = filp
->private_data
;
1523 struct trace_seq
*s
;
1529 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
1536 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
,
1537 s
->buffer
, trace_seq_used(s
));
1544 static int max_pids(struct trace_pid_list
*pid_list
)
1546 return (PAGE_SIZE
<< pid_list
->order
) / sizeof(pid_t
);
1549 static void ignore_task_cpu(void *data
)
1551 struct trace_array
*tr
= data
;
1552 struct trace_pid_list
*pid_list
;
1555 * This function is called by on_each_cpu() while the
1556 * event_mutex is held.
1558 pid_list
= rcu_dereference_protected(tr
->filtered_pids
,
1559 mutex_is_locked(&event_mutex
));
1561 this_cpu_write(tr
->trace_buffer
.data
->ignore_pid
,
1562 check_ignore_pid(pid_list
, current
));
1566 ftrace_event_pid_write(struct file
*filp
, const char __user
*ubuf
,
1567 size_t cnt
, loff_t
*ppos
)
1569 struct seq_file
*m
= filp
->private_data
;
1570 struct trace_array
*tr
= m
->private;
1571 struct trace_pid_list
*filtered_pids
= NULL
;
1572 struct trace_pid_list
*pid_list
= NULL
;
1573 struct trace_event_file
*file
;
1574 struct trace_parser parser
;
1585 ret
= tracing_update_buffers();
1589 if (trace_parser_get_init(&parser
, EVENT_BUF_SIZE
+ 1))
1592 mutex_lock(&event_mutex
);
1594 * Load as many pids into the array before doing a
1595 * swap from the tr->filtered_pids to the new list.
1601 ret
= trace_get_user(&parser
, ubuf
, cnt
, &this_pos
);
1602 if (ret
< 0 || !trace_parser_loaded(&parser
))
1609 parser
.buffer
[parser
.idx
] = 0;
1612 if (kstrtoul(parser
.buffer
, 0, &val
))
1621 pid_list
= kmalloc(sizeof(*pid_list
), GFP_KERNEL
);
1625 filtered_pids
= rcu_dereference_protected(tr
->filtered_pids
,
1626 lockdep_is_held(&event_mutex
));
1628 pid_list
->order
= filtered_pids
->order
;
1630 pid_list
->order
= 0;
1632 pid_list
->pids
= (void *)__get_free_pages(GFP_KERNEL
,
1634 if (!pid_list
->pids
)
1637 if (filtered_pids
) {
1638 pid_list
->nr_pids
= filtered_pids
->nr_pids
;
1639 memcpy(pid_list
->pids
, filtered_pids
->pids
,
1640 pid_list
->nr_pids
* sizeof(pid_t
));
1642 pid_list
->nr_pids
= 0;
1645 if (pid_list
->nr_pids
>= max_pids(pid_list
)) {
1648 pid_page
= (void *)__get_free_pages(GFP_KERNEL
,
1649 pid_list
->order
+ 1);
1652 memcpy(pid_page
, pid_list
->pids
,
1653 pid_list
->nr_pids
* sizeof(pid_t
));
1654 free_pages((unsigned long)pid_list
->pids
, pid_list
->order
);
1657 pid_list
->pids
= pid_page
;
1660 pid_list
->pids
[pid_list
->nr_pids
++] = pid
;
1661 trace_parser_clear(&parser
);
1664 trace_parser_put(&parser
);
1668 free_pages((unsigned long)pid_list
->pids
, pid_list
->order
);
1670 mutex_unlock(&event_mutex
);
1675 mutex_unlock(&event_mutex
);
1679 sort(pid_list
->pids
, pid_list
->nr_pids
, sizeof(pid_t
), cmp_pid
, NULL
);
1681 /* Remove duplicates */
1682 for (i
= 1; i
< pid_list
->nr_pids
; i
++) {
1685 while (i
< pid_list
->nr_pids
&&
1686 pid_list
->pids
[i
- 1] == pid_list
->pids
[i
])
1690 if (i
< pid_list
->nr_pids
) {
1691 memmove(&pid_list
->pids
[start
], &pid_list
->pids
[i
],
1692 (pid_list
->nr_pids
- i
) * sizeof(pid_t
));
1693 pid_list
->nr_pids
-= i
- start
;
1696 pid_list
->nr_pids
= start
;
1700 rcu_assign_pointer(tr
->filtered_pids
, pid_list
);
1702 list_for_each_entry(file
, &tr
->events
, list
) {
1703 set_bit(EVENT_FILE_FL_PID_FILTER_BIT
, &file
->flags
);
1706 if (filtered_pids
) {
1707 synchronize_sched();
1709 free_pages((unsigned long)filtered_pids
->pids
, filtered_pids
->order
);
1710 kfree(filtered_pids
);
1713 * Register a probe that is called before all other probes
1714 * to set ignore_pid if next or prev do not match.
1715 * Register a probe this is called after all other probes
1716 * to only keep ignore_pid set if next pid matches.
1718 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre
,
1720 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post
,
1723 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre
,
1725 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post
,
1728 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre
,
1730 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post
,
1733 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre
,
1735 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post
,
1740 * Ignoring of pids is done at task switch. But we have to
1741 * check for those tasks that are currently running.
1742 * Always do this in case a pid was appended or removed.
1744 on_each_cpu(ignore_task_cpu
, tr
, 1);
1746 mutex_unlock(&event_mutex
);
1754 static int ftrace_event_avail_open(struct inode
*inode
, struct file
*file
);
1755 static int ftrace_event_set_open(struct inode
*inode
, struct file
*file
);
1756 static int ftrace_event_set_pid_open(struct inode
*inode
, struct file
*file
);
1757 static int ftrace_event_release(struct inode
*inode
, struct file
*file
);
1759 static const struct seq_operations show_event_seq_ops
= {
1766 static const struct seq_operations show_set_event_seq_ops
= {
1773 static const struct seq_operations show_set_pid_seq_ops
= {
1780 static const struct file_operations ftrace_avail_fops
= {
1781 .open
= ftrace_event_avail_open
,
1783 .llseek
= seq_lseek
,
1784 .release
= seq_release
,
1787 static const struct file_operations ftrace_set_event_fops
= {
1788 .open
= ftrace_event_set_open
,
1790 .write
= ftrace_event_write
,
1791 .llseek
= seq_lseek
,
1792 .release
= ftrace_event_release
,
1795 static const struct file_operations ftrace_set_event_pid_fops
= {
1796 .open
= ftrace_event_set_pid_open
,
1798 .write
= ftrace_event_pid_write
,
1799 .llseek
= seq_lseek
,
1800 .release
= ftrace_event_release
,
1803 static const struct file_operations ftrace_enable_fops
= {
1804 .open
= tracing_open_generic
,
1805 .read
= event_enable_read
,
1806 .write
= event_enable_write
,
1807 .llseek
= default_llseek
,
1810 static const struct file_operations ftrace_event_format_fops
= {
1811 .open
= trace_format_open
,
1813 .llseek
= seq_lseek
,
1814 .release
= seq_release
,
1817 static const struct file_operations ftrace_event_id_fops
= {
1818 .read
= event_id_read
,
1819 .llseek
= default_llseek
,
1822 static const struct file_operations ftrace_event_filter_fops
= {
1823 .open
= tracing_open_generic
,
1824 .read
= event_filter_read
,
1825 .write
= event_filter_write
,
1826 .llseek
= default_llseek
,
1829 static const struct file_operations ftrace_subsystem_filter_fops
= {
1830 .open
= subsystem_open
,
1831 .read
= subsystem_filter_read
,
1832 .write
= subsystem_filter_write
,
1833 .llseek
= default_llseek
,
1834 .release
= subsystem_release
,
1837 static const struct file_operations ftrace_system_enable_fops
= {
1838 .open
= subsystem_open
,
1839 .read
= system_enable_read
,
1840 .write
= system_enable_write
,
1841 .llseek
= default_llseek
,
1842 .release
= subsystem_release
,
1845 static const struct file_operations ftrace_tr_enable_fops
= {
1846 .open
= system_tr_open
,
1847 .read
= system_enable_read
,
1848 .write
= system_enable_write
,
1849 .llseek
= default_llseek
,
1850 .release
= subsystem_release
,
1853 static const struct file_operations ftrace_show_header_fops
= {
1854 .open
= tracing_open_generic
,
1855 .read
= show_header
,
1856 .llseek
= default_llseek
,
1860 ftrace_event_open(struct inode
*inode
, struct file
*file
,
1861 const struct seq_operations
*seq_ops
)
1866 ret
= seq_open(file
, seq_ops
);
1869 m
= file
->private_data
;
1870 /* copy tr over to seq ops */
1871 m
->private = inode
->i_private
;
1876 static int ftrace_event_release(struct inode
*inode
, struct file
*file
)
1878 struct trace_array
*tr
= inode
->i_private
;
1880 trace_array_put(tr
);
1882 return seq_release(inode
, file
);
1886 ftrace_event_avail_open(struct inode
*inode
, struct file
*file
)
1888 const struct seq_operations
*seq_ops
= &show_event_seq_ops
;
1890 return ftrace_event_open(inode
, file
, seq_ops
);
1894 ftrace_event_set_open(struct inode
*inode
, struct file
*file
)
1896 const struct seq_operations
*seq_ops
= &show_set_event_seq_ops
;
1897 struct trace_array
*tr
= inode
->i_private
;
1900 if (trace_array_get(tr
) < 0)
1903 if ((file
->f_mode
& FMODE_WRITE
) &&
1904 (file
->f_flags
& O_TRUNC
))
1905 ftrace_clear_events(tr
);
1907 ret
= ftrace_event_open(inode
, file
, seq_ops
);
1909 trace_array_put(tr
);
1914 ftrace_event_set_pid_open(struct inode
*inode
, struct file
*file
)
1916 const struct seq_operations
*seq_ops
= &show_set_pid_seq_ops
;
1917 struct trace_array
*tr
= inode
->i_private
;
1920 if (trace_array_get(tr
) < 0)
1923 if ((file
->f_mode
& FMODE_WRITE
) &&
1924 (file
->f_flags
& O_TRUNC
))
1925 ftrace_clear_event_pids(tr
);
1927 ret
= ftrace_event_open(inode
, file
, seq_ops
);
1929 trace_array_put(tr
);
1933 static struct event_subsystem
*
1934 create_new_subsystem(const char *name
)
1936 struct event_subsystem
*system
;
1938 /* need to create new entry */
1939 system
= kmalloc(sizeof(*system
), GFP_KERNEL
);
1943 system
->ref_count
= 1;
1945 /* Only allocate if dynamic (kprobes and modules) */
1946 system
->name
= kstrdup_const(name
, GFP_KERNEL
);
1950 system
->filter
= NULL
;
1952 system
->filter
= kzalloc(sizeof(struct event_filter
), GFP_KERNEL
);
1953 if (!system
->filter
)
1956 list_add(&system
->list
, &event_subsystems
);
1961 kfree_const(system
->name
);
1966 static struct dentry
*
1967 event_subsystem_dir(struct trace_array
*tr
, const char *name
,
1968 struct trace_event_file
*file
, struct dentry
*parent
)
1970 struct trace_subsystem_dir
*dir
;
1971 struct event_subsystem
*system
;
1972 struct dentry
*entry
;
1974 /* First see if we did not already create this dir */
1975 list_for_each_entry(dir
, &tr
->systems
, list
) {
1976 system
= dir
->subsystem
;
1977 if (strcmp(system
->name
, name
) == 0) {
1984 /* Now see if the system itself exists. */
1985 list_for_each_entry(system
, &event_subsystems
, list
) {
1986 if (strcmp(system
->name
, name
) == 0)
1989 /* Reset system variable when not found */
1990 if (&system
->list
== &event_subsystems
)
1993 dir
= kmalloc(sizeof(*dir
), GFP_KERNEL
);
1998 system
= create_new_subsystem(name
);
2002 __get_system(system
);
2004 dir
->entry
= tracefs_create_dir(name
, parent
);
2006 pr_warn("Failed to create system directory %s\n", name
);
2007 __put_system(system
);
2014 dir
->subsystem
= system
;
2017 entry
= tracefs_create_file("filter", 0644, dir
->entry
, dir
,
2018 &ftrace_subsystem_filter_fops
);
2020 kfree(system
->filter
);
2021 system
->filter
= NULL
;
2022 pr_warn("Could not create tracefs '%s/filter' entry\n", name
);
2025 trace_create_file("enable", 0644, dir
->entry
, dir
,
2026 &ftrace_system_enable_fops
);
2028 list_add(&dir
->list
, &tr
->systems
);
2035 /* Only print this message if failed on memory allocation */
2036 if (!dir
|| !system
)
2037 pr_warn("No memory to create event subsystem %s\n", name
);
2042 event_create_dir(struct dentry
*parent
, struct trace_event_file
*file
)
2044 struct trace_event_call
*call
= file
->event_call
;
2045 struct trace_array
*tr
= file
->tr
;
2046 struct list_head
*head
;
2047 struct dentry
*d_events
;
2052 * If the trace point header did not define TRACE_SYSTEM
2053 * then the system would be called "TRACE_SYSTEM".
2055 if (strcmp(call
->class->system
, TRACE_SYSTEM
) != 0) {
2056 d_events
= event_subsystem_dir(tr
, call
->class->system
, file
, parent
);
2062 name
= trace_event_name(call
);
2063 file
->dir
= tracefs_create_dir(name
, d_events
);
2065 pr_warn("Could not create tracefs '%s' directory\n", name
);
2069 if (call
->class->reg
&& !(call
->flags
& TRACE_EVENT_FL_IGNORE_ENABLE
))
2070 trace_create_file("enable", 0644, file
->dir
, file
,
2071 &ftrace_enable_fops
);
2073 #ifdef CONFIG_PERF_EVENTS
2074 if (call
->event
.type
&& call
->class->reg
)
2075 trace_create_file("id", 0444, file
->dir
,
2076 (void *)(long)call
->event
.type
,
2077 &ftrace_event_id_fops
);
2081 * Other events may have the same class. Only update
2082 * the fields if they are not already defined.
2084 head
= trace_get_fields(call
);
2085 if (list_empty(head
)) {
2086 ret
= call
->class->define_fields(call
);
2088 pr_warn("Could not initialize trace point events/%s\n",
2093 trace_create_file("filter", 0644, file
->dir
, file
,
2094 &ftrace_event_filter_fops
);
2096 trace_create_file("trigger", 0644, file
->dir
, file
,
2097 &event_trigger_fops
);
2099 trace_create_file("format", 0444, file
->dir
, call
,
2100 &ftrace_event_format_fops
);
2105 static void remove_event_from_tracers(struct trace_event_call
*call
)
2107 struct trace_event_file
*file
;
2108 struct trace_array
*tr
;
2110 do_for_each_event_file_safe(tr
, file
) {
2111 if (file
->event_call
!= call
)
2114 remove_event_file_dir(file
);
2116 * The do_for_each_event_file_safe() is
2117 * a double loop. After finding the call for this
2118 * trace_array, we use break to jump to the next
2122 } while_for_each_event_file();
2125 static void event_remove(struct trace_event_call
*call
)
2127 struct trace_array
*tr
;
2128 struct trace_event_file
*file
;
2130 do_for_each_event_file(tr
, file
) {
2131 if (file
->event_call
!= call
)
2133 ftrace_event_enable_disable(file
, 0);
2135 * The do_for_each_event_file() is
2136 * a double loop. After finding the call for this
2137 * trace_array, we use break to jump to the next
2141 } while_for_each_event_file();
2143 if (call
->event
.funcs
)
2144 __unregister_trace_event(&call
->event
);
2145 remove_event_from_tracers(call
);
2146 list_del(&call
->list
);
2149 static int event_init(struct trace_event_call
*call
)
2154 name
= trace_event_name(call
);
2158 if (call
->class->raw_init
) {
2159 ret
= call
->class->raw_init(call
);
2160 if (ret
< 0 && ret
!= -ENOSYS
)
2161 pr_warn("Could not initialize trace events/%s\n", name
);
2168 __register_event(struct trace_event_call
*call
, struct module
*mod
)
2172 ret
= event_init(call
);
2176 list_add(&call
->list
, &ftrace_events
);
2182 static char *enum_replace(char *ptr
, struct trace_enum_map
*map
, int len
)
2187 /* Find the length of the enum value as a string */
2188 elen
= snprintf(ptr
, 0, "%ld", map
->enum_value
);
2189 /* Make sure there's enough room to replace the string with the value */
2193 snprintf(ptr
, elen
+ 1, "%ld", map
->enum_value
);
2195 /* Get the rest of the string of ptr */
2196 rlen
= strlen(ptr
+ len
);
2197 memmove(ptr
+ elen
, ptr
+ len
, rlen
);
2198 /* Make sure we end the new string */
2199 ptr
[elen
+ rlen
] = 0;
2204 static void update_event_printk(struct trace_event_call
*call
,
2205 struct trace_enum_map
*map
)
2209 int len
= strlen(map
->enum_string
);
2211 for (ptr
= call
->print_fmt
; *ptr
; ptr
++) {
2225 if (isdigit(*ptr
)) {
2229 /* Check for alpha chars like ULL */
2230 } while (isalnum(*ptr
));
2234 * A number must have some kind of delimiter after
2235 * it, and we can ignore that too.
2239 if (isalpha(*ptr
) || *ptr
== '_') {
2240 if (strncmp(map
->enum_string
, ptr
, len
) == 0 &&
2241 !isalnum(ptr
[len
]) && ptr
[len
] != '_') {
2242 ptr
= enum_replace(ptr
, map
, len
);
2243 /* Hmm, enum string smaller than value */
2244 if (WARN_ON_ONCE(!ptr
))
2247 * No need to decrement here, as enum_replace()
2248 * returns the pointer to the character passed
2249 * the enum, and two enums can not be placed
2250 * back to back without something in between.
2251 * We can skip that something in between.
2258 } while (isalnum(*ptr
) || *ptr
== '_');
2262 * If what comes after this variable is a '.' or
2263 * '->' then we can continue to ignore that string.
2265 if (*ptr
== '.' || (ptr
[0] == '-' && ptr
[1] == '>')) {
2266 ptr
+= *ptr
== '.' ? 1 : 2;
2272 * Once again, we can skip the delimiter that came
2280 void trace_event_enum_update(struct trace_enum_map
**map
, int len
)
2282 struct trace_event_call
*call
, *p
;
2283 const char *last_system
= NULL
;
2287 down_write(&trace_event_sem
);
2288 list_for_each_entry_safe(call
, p
, &ftrace_events
, list
) {
2289 /* events are usually grouped together with systems */
2290 if (!last_system
|| call
->class->system
!= last_system
) {
2292 last_system
= call
->class->system
;
2295 for (i
= last_i
; i
< len
; i
++) {
2296 if (call
->class->system
== map
[i
]->system
) {
2297 /* Save the first system if need be */
2300 update_event_printk(call
, map
[i
]);
2304 up_write(&trace_event_sem
);
2307 static struct trace_event_file
*
2308 trace_create_new_event(struct trace_event_call
*call
,
2309 struct trace_array
*tr
)
2311 struct trace_event_file
*file
;
2313 file
= kmem_cache_alloc(file_cachep
, GFP_TRACE
);
2317 file
->event_call
= call
;
2319 atomic_set(&file
->sm_ref
, 0);
2320 atomic_set(&file
->tm_ref
, 0);
2321 INIT_LIST_HEAD(&file
->triggers
);
2322 list_add(&file
->list
, &tr
->events
);
2327 /* Add an event to a trace directory */
2329 __trace_add_new_event(struct trace_event_call
*call
, struct trace_array
*tr
)
2331 struct trace_event_file
*file
;
2333 file
= trace_create_new_event(call
, tr
);
2337 return event_create_dir(tr
->event_dir
, file
);
2341 * Just create a decriptor for early init. A descriptor is required
2342 * for enabling events at boot. We want to enable events before
2343 * the filesystem is initialized.
2346 __trace_early_add_new_event(struct trace_event_call
*call
,
2347 struct trace_array
*tr
)
2349 struct trace_event_file
*file
;
2351 file
= trace_create_new_event(call
, tr
);
2358 struct ftrace_module_file_ops
;
2359 static void __add_event_to_tracers(struct trace_event_call
*call
);
2361 /* Add an additional event_call dynamically */
2362 int trace_add_event_call(struct trace_event_call
*call
)
2365 mutex_lock(&trace_types_lock
);
2366 mutex_lock(&event_mutex
);
2368 ret
= __register_event(call
, NULL
);
2370 __add_event_to_tracers(call
);
2372 mutex_unlock(&event_mutex
);
2373 mutex_unlock(&trace_types_lock
);
2378 * Must be called under locking of trace_types_lock, event_mutex and
2381 static void __trace_remove_event_call(struct trace_event_call
*call
)
2384 trace_destroy_fields(call
);
2385 free_event_filter(call
->filter
);
2386 call
->filter
= NULL
;
2389 static int probe_remove_event_call(struct trace_event_call
*call
)
2391 struct trace_array
*tr
;
2392 struct trace_event_file
*file
;
2394 #ifdef CONFIG_PERF_EVENTS
2395 if (call
->perf_refcount
)
2398 do_for_each_event_file(tr
, file
) {
2399 if (file
->event_call
!= call
)
2402 * We can't rely on ftrace_event_enable_disable(enable => 0)
2403 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2404 * TRACE_REG_UNREGISTER.
2406 if (file
->flags
& EVENT_FILE_FL_ENABLED
)
2409 * The do_for_each_event_file_safe() is
2410 * a double loop. After finding the call for this
2411 * trace_array, we use break to jump to the next
2415 } while_for_each_event_file();
2417 __trace_remove_event_call(call
);
2422 /* Remove an event_call */
2423 int trace_remove_event_call(struct trace_event_call
*call
)
2427 mutex_lock(&trace_types_lock
);
2428 mutex_lock(&event_mutex
);
2429 down_write(&trace_event_sem
);
2430 ret
= probe_remove_event_call(call
);
2431 up_write(&trace_event_sem
);
2432 mutex_unlock(&event_mutex
);
2433 mutex_unlock(&trace_types_lock
);
2438 #define for_each_event(event, start, end) \
2439 for (event = start; \
2440 (unsigned long)event < (unsigned long)end; \
2443 #ifdef CONFIG_MODULES
2445 static void trace_module_add_events(struct module
*mod
)
2447 struct trace_event_call
**call
, **start
, **end
;
2449 if (!mod
->num_trace_events
)
2452 /* Don't add infrastructure for mods without tracepoints */
2453 if (trace_module_has_bad_taint(mod
)) {
2454 pr_err("%s: module has bad taint, not creating trace events\n",
2459 start
= mod
->trace_events
;
2460 end
= mod
->trace_events
+ mod
->num_trace_events
;
2462 for_each_event(call
, start
, end
) {
2463 __register_event(*call
, mod
);
2464 __add_event_to_tracers(*call
);
2468 static void trace_module_remove_events(struct module
*mod
)
2470 struct trace_event_call
*call
, *p
;
2471 bool clear_trace
= false;
2473 down_write(&trace_event_sem
);
2474 list_for_each_entry_safe(call
, p
, &ftrace_events
, list
) {
2475 if (call
->mod
== mod
) {
2476 if (call
->flags
& TRACE_EVENT_FL_WAS_ENABLED
)
2478 __trace_remove_event_call(call
);
2481 up_write(&trace_event_sem
);
2484 * It is safest to reset the ring buffer if the module being unloaded
2485 * registered any events that were used. The only worry is if
2486 * a new module gets loaded, and takes on the same id as the events
2487 * of this module. When printing out the buffer, traced events left
2488 * over from this module may be passed to the new module events and
2489 * unexpected results may occur.
2492 tracing_reset_all_online_cpus();
2495 static int trace_module_notify(struct notifier_block
*self
,
2496 unsigned long val
, void *data
)
2498 struct module
*mod
= data
;
2500 mutex_lock(&trace_types_lock
);
2501 mutex_lock(&event_mutex
);
2503 case MODULE_STATE_COMING
:
2504 trace_module_add_events(mod
);
2506 case MODULE_STATE_GOING
:
2507 trace_module_remove_events(mod
);
2510 mutex_unlock(&event_mutex
);
2511 mutex_unlock(&trace_types_lock
);
2516 static struct notifier_block trace_module_nb
= {
2517 .notifier_call
= trace_module_notify
,
2518 .priority
= 1, /* higher than trace.c module notify */
2520 #endif /* CONFIG_MODULES */
2522 /* Create a new event directory structure for a trace directory. */
2524 __trace_add_event_dirs(struct trace_array
*tr
)
2526 struct trace_event_call
*call
;
2529 list_for_each_entry(call
, &ftrace_events
, list
) {
2530 ret
= __trace_add_new_event(call
, tr
);
2532 pr_warn("Could not create directory for event %s\n",
2533 trace_event_name(call
));
2537 struct trace_event_file
*
2538 find_event_file(struct trace_array
*tr
, const char *system
, const char *event
)
2540 struct trace_event_file
*file
;
2541 struct trace_event_call
*call
;
2544 list_for_each_entry(file
, &tr
->events
, list
) {
2546 call
= file
->event_call
;
2547 name
= trace_event_name(call
);
2549 if (!name
|| !call
->class || !call
->class->reg
)
2552 if (call
->flags
& TRACE_EVENT_FL_IGNORE_ENABLE
)
2555 if (strcmp(event
, name
) == 0 &&
2556 strcmp(system
, call
->class->system
) == 0)
2562 #ifdef CONFIG_DYNAMIC_FTRACE
2565 #define ENABLE_EVENT_STR "enable_event"
2566 #define DISABLE_EVENT_STR "disable_event"
2568 struct event_probe_data
{
2569 struct trace_event_file
*file
;
2570 unsigned long count
;
2576 event_enable_probe(unsigned long ip
, unsigned long parent_ip
, void **_data
)
2578 struct event_probe_data
**pdata
= (struct event_probe_data
**)_data
;
2579 struct event_probe_data
*data
= *pdata
;
2585 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT
, &data
->file
->flags
);
2587 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT
, &data
->file
->flags
);
2591 event_enable_count_probe(unsigned long ip
, unsigned long parent_ip
, void **_data
)
2593 struct event_probe_data
**pdata
= (struct event_probe_data
**)_data
;
2594 struct event_probe_data
*data
= *pdata
;
2602 /* Skip if the event is in a state we want to switch to */
2603 if (data
->enable
== !(data
->file
->flags
& EVENT_FILE_FL_SOFT_DISABLED
))
2606 if (data
->count
!= -1)
2609 event_enable_probe(ip
, parent_ip
, _data
);
2613 event_enable_print(struct seq_file
*m
, unsigned long ip
,
2614 struct ftrace_probe_ops
*ops
, void *_data
)
2616 struct event_probe_data
*data
= _data
;
2618 seq_printf(m
, "%ps:", (void *)ip
);
2620 seq_printf(m
, "%s:%s:%s",
2621 data
->enable
? ENABLE_EVENT_STR
: DISABLE_EVENT_STR
,
2622 data
->file
->event_call
->class->system
,
2623 trace_event_name(data
->file
->event_call
));
2625 if (data
->count
== -1)
2626 seq_puts(m
, ":unlimited\n");
2628 seq_printf(m
, ":count=%ld\n", data
->count
);
2634 event_enable_init(struct ftrace_probe_ops
*ops
, unsigned long ip
,
2637 struct event_probe_data
**pdata
= (struct event_probe_data
**)_data
;
2638 struct event_probe_data
*data
= *pdata
;
2645 event_enable_free(struct ftrace_probe_ops
*ops
, unsigned long ip
,
2648 struct event_probe_data
**pdata
= (struct event_probe_data
**)_data
;
2649 struct event_probe_data
*data
= *pdata
;
2651 if (WARN_ON_ONCE(data
->ref
<= 0))
2656 /* Remove the SOFT_MODE flag */
2657 __ftrace_event_enable_disable(data
->file
, 0, 1);
2658 module_put(data
->file
->event_call
->mod
);
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 ftrace_hash
*hash
,
2694 char *glob
, char *cmd
, char *param
, int enabled
)
2696 struct trace_array
*tr
= top_trace_array();
2697 struct trace_event_file
*file
;
2698 struct ftrace_probe_ops
*ops
;
2699 struct event_probe_data
*data
;
2709 /* hash funcs only work with set_ftrace_filter */
2710 if (!enabled
|| !param
)
2713 system
= strsep(¶m
, ":");
2717 event
= strsep(¶m
, ":");
2719 mutex_lock(&event_mutex
);
2722 file
= find_event_file(tr
, system
, event
);
2726 enable
= strcmp(cmd
, ENABLE_EVENT_STR
) == 0;
2729 ops
= param
? &event_enable_count_probe_ops
: &event_enable_probe_ops
;
2731 ops
= param
? &event_disable_count_probe_ops
: &event_disable_probe_ops
;
2733 if (glob
[0] == '!') {
2734 unregister_ftrace_function_probe_func(glob
+1, ops
);
2740 data
= kzalloc(sizeof(*data
), GFP_KERNEL
);
2744 data
->enable
= enable
;
2751 number
= strsep(¶m
, ":");
2754 if (!strlen(number
))
2758 * We use the callback data field (which is a pointer)
2761 ret
= kstrtoul(number
, 0, &data
->count
);
2766 /* Don't let event modules unload while probe registered */
2767 ret
= try_module_get(file
->event_call
->mod
);
2773 ret
= __ftrace_event_enable_disable(file
, 1, 1);
2776 ret
= register_ftrace_function_probe(glob
, 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
= tracefs_create_file("set_event_pid", 0644, parent
,
2928 tr
, &ftrace_set_event_pid_fops
);
2930 /* ring buffer internal formats */
2931 trace_create_file("header_page", 0444, d_events
,
2932 ring_buffer_print_page_header
,
2933 &ftrace_show_header_fops
);
2935 trace_create_file("header_event", 0444, d_events
,
2936 ring_buffer_print_entry_header
,
2937 &ftrace_show_header_fops
);
2939 trace_create_file("enable", 0644, d_events
,
2940 tr
, &ftrace_tr_enable_fops
);
2942 tr
->event_dir
= d_events
;
2948 * event_trace_add_tracer - add a instance of a trace_array to events
2949 * @parent: The parent dentry to place the files/directories for events in
2950 * @tr: The trace array associated with these events
2952 * When a new instance is created, it needs to set up its events
2953 * directory, as well as other files associated with events. It also
2954 * creates the event hierachry in the @parent/events directory.
2956 * Returns 0 on success.
2958 int event_trace_add_tracer(struct dentry
*parent
, struct trace_array
*tr
)
2962 mutex_lock(&event_mutex
);
2964 ret
= create_event_toplevel_files(parent
, tr
);
2968 down_write(&trace_event_sem
);
2969 __trace_add_event_dirs(tr
);
2970 up_write(&trace_event_sem
);
2973 mutex_unlock(&event_mutex
);
2979 * The top trace array already had its file descriptors created.
2980 * Now the files themselves need to be created.
2983 early_event_add_tracer(struct dentry
*parent
, struct trace_array
*tr
)
2987 mutex_lock(&event_mutex
);
2989 ret
= create_event_toplevel_files(parent
, tr
);
2993 down_write(&trace_event_sem
);
2994 __trace_early_add_event_dirs(tr
);
2995 up_write(&trace_event_sem
);
2998 mutex_unlock(&event_mutex
);
3003 int event_trace_del_tracer(struct trace_array
*tr
)
3005 mutex_lock(&event_mutex
);
3007 /* Disable any event triggers and associated soft-disabled events */
3008 clear_event_triggers(tr
);
3010 /* Clear the pid list */
3011 __ftrace_clear_event_pids(tr
);
3013 /* Disable any running events */
3014 __ftrace_set_clr_event_nolock(tr
, NULL
, NULL
, NULL
, 0);
3016 /* Access to events are within rcu_read_lock_sched() */
3017 synchronize_sched();
3019 down_write(&trace_event_sem
);
3020 __trace_remove_event_dirs(tr
);
3021 tracefs_remove_recursive(tr
->event_dir
);
3022 up_write(&trace_event_sem
);
3024 tr
->event_dir
= NULL
;
3026 mutex_unlock(&event_mutex
);
3031 static __init
int event_trace_memsetup(void)
3033 field_cachep
= KMEM_CACHE(ftrace_event_field
, SLAB_PANIC
);
3034 file_cachep
= KMEM_CACHE(trace_event_file
, SLAB_PANIC
);
3039 early_enable_events(struct trace_array
*tr
, bool disable_first
)
3041 char *buf
= bootup_event_buf
;
3046 token
= strsep(&buf
, ",");
3052 /* Restarting syscalls requires that we stop them first */
3054 ftrace_set_clr_event(tr
, token
, 0);
3056 ret
= ftrace_set_clr_event(tr
, token
, 1);
3058 pr_warn("Failed to enable trace event: %s\n", token
);
3061 /* Put back the comma to allow this to be called again */
3067 static __init
int event_trace_enable(void)
3069 struct trace_array
*tr
= top_trace_array();
3070 struct trace_event_call
**iter
, *call
;
3076 for_each_event(iter
, __start_ftrace_events
, __stop_ftrace_events
) {
3079 ret
= event_init(call
);
3081 list_add(&call
->list
, &ftrace_events
);
3085 * We need the top trace array to have a working set of trace
3086 * points at early init, before the debug files and directories
3087 * are created. Create the file entries now, and attach them
3088 * to the actual file dentries later.
3090 __trace_early_add_events(tr
);
3092 early_enable_events(tr
, false);
3094 trace_printk_start_comm();
3096 register_event_cmds();
3098 register_trigger_cmds();
3104 * event_trace_enable() is called from trace_event_init() first to
3105 * initialize events and perhaps start any events that are on the
3106 * command line. Unfortunately, there are some events that will not
3107 * start this early, like the system call tracepoints that need
3108 * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
3109 * is called before pid 1 starts, and this flag is never set, making
3110 * the syscall tracepoint never get reached, but the event is enabled
3111 * regardless (and not doing anything).
3113 static __init
int event_trace_enable_again(void)
3115 struct trace_array
*tr
;
3117 tr
= top_trace_array();
3121 early_enable_events(tr
, true);
3126 early_initcall(event_trace_enable_again
);
3128 static __init
int event_trace_init(void)
3130 struct trace_array
*tr
;
3131 struct dentry
*d_tracer
;
3132 struct dentry
*entry
;
3135 tr
= top_trace_array();
3139 d_tracer
= tracing_init_dentry();
3140 if (IS_ERR(d_tracer
))
3143 entry
= tracefs_create_file("available_events", 0444, d_tracer
,
3144 tr
, &ftrace_avail_fops
);
3146 pr_warn("Could not create tracefs 'available_events' entry\n");
3148 if (trace_define_generic_fields())
3149 pr_warn("tracing: Failed to allocated generic fields");
3151 if (trace_define_common_fields())
3152 pr_warn("tracing: Failed to allocate common fields");
3154 ret
= early_event_add_tracer(d_tracer
, tr
);
3158 #ifdef CONFIG_MODULES
3159 ret
= register_module_notifier(&trace_module_nb
);
3161 pr_warn("Failed to register trace events module notifier\n");
3166 void __init
trace_event_init(void)
3168 event_trace_memsetup();
3169 init_ftrace_syscalls();
3170 event_trace_enable();
3173 fs_initcall(event_trace_init
);
3175 #ifdef CONFIG_FTRACE_STARTUP_TEST
3177 static DEFINE_SPINLOCK(test_spinlock
);
3178 static DEFINE_SPINLOCK(test_spinlock_irq
);
3179 static DEFINE_MUTEX(test_mutex
);
3181 static __init
void test_work(struct work_struct
*dummy
)
3183 spin_lock(&test_spinlock
);
3184 spin_lock_irq(&test_spinlock_irq
);
3186 spin_unlock_irq(&test_spinlock_irq
);
3187 spin_unlock(&test_spinlock
);
3189 mutex_lock(&test_mutex
);
3191 mutex_unlock(&test_mutex
);
3194 static __init
int event_test_thread(void *unused
)
3198 test_malloc
= kmalloc(1234, GFP_KERNEL
);
3200 pr_info("failed to kmalloc\n");
3202 schedule_on_each_cpu(test_work
);
3206 set_current_state(TASK_INTERRUPTIBLE
);
3207 while (!kthread_should_stop()) {
3209 set_current_state(TASK_INTERRUPTIBLE
);
3211 __set_current_state(TASK_RUNNING
);
3217 * Do various things that may trigger events.
3219 static __init
void event_test_stuff(void)
3221 struct task_struct
*test_thread
;
3223 test_thread
= kthread_run(event_test_thread
, NULL
, "test-events");
3225 kthread_stop(test_thread
);
3229 * For every trace event defined, we will test each trace point separately,
3230 * and then by groups, and finally all trace points.
3232 static __init
void event_trace_self_tests(void)
3234 struct trace_subsystem_dir
*dir
;
3235 struct trace_event_file
*file
;
3236 struct trace_event_call
*call
;
3237 struct event_subsystem
*system
;
3238 struct trace_array
*tr
;
3241 tr
= top_trace_array();
3245 pr_info("Running tests on trace events:\n");
3247 list_for_each_entry(file
, &tr
->events
, list
) {
3249 call
= file
->event_call
;
3251 /* Only test those that have a probe */
3252 if (!call
->class || !call
->class->probe
)
3256 * Testing syscall events here is pretty useless, but
3257 * we still do it if configured. But this is time consuming.
3258 * What we really need is a user thread to perform the
3259 * syscalls as we test.
3261 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3262 if (call
->class->system
&&
3263 strcmp(call
->class->system
, "syscalls") == 0)
3267 pr_info("Testing event %s: ", trace_event_name(call
));
3270 * If an event is already enabled, someone is using
3271 * it and the self test should not be on.
3273 if (file
->flags
& EVENT_FILE_FL_ENABLED
) {
3274 pr_warn("Enabled event during self test!\n");
3279 ftrace_event_enable_disable(file
, 1);
3281 ftrace_event_enable_disable(file
, 0);
3286 /* Now test at the sub system level */
3288 pr_info("Running tests on trace event systems:\n");
3290 list_for_each_entry(dir
, &tr
->systems
, list
) {
3292 system
= dir
->subsystem
;
3294 /* the ftrace system is special, skip it */
3295 if (strcmp(system
->name
, "ftrace") == 0)
3298 pr_info("Testing event system %s: ", system
->name
);
3300 ret
= __ftrace_set_clr_event(tr
, NULL
, system
->name
, NULL
, 1);
3301 if (WARN_ON_ONCE(ret
)) {
3302 pr_warn("error enabling system %s\n",
3309 ret
= __ftrace_set_clr_event(tr
, NULL
, system
->name
, NULL
, 0);
3310 if (WARN_ON_ONCE(ret
)) {
3311 pr_warn("error disabling system %s\n",
3319 /* Test with all events enabled */
3321 pr_info("Running tests on all trace events:\n");
3322 pr_info("Testing all events: ");
3324 ret
= __ftrace_set_clr_event(tr
, NULL
, NULL
, NULL
, 1);
3325 if (WARN_ON_ONCE(ret
)) {
3326 pr_warn("error enabling all events\n");
3333 ret
= __ftrace_set_clr_event(tr
, NULL
, NULL
, NULL
, 0);
3334 if (WARN_ON_ONCE(ret
)) {
3335 pr_warn("error disabling all events\n");
3342 #ifdef CONFIG_FUNCTION_TRACER
3344 static DEFINE_PER_CPU(atomic_t
, ftrace_test_event_disable
);
3346 static struct trace_array
*event_tr
;
3349 function_test_events_call(unsigned long ip
, unsigned long parent_ip
,
3350 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
3352 struct ring_buffer_event
*event
;
3353 struct ring_buffer
*buffer
;
3354 struct ftrace_entry
*entry
;
3355 unsigned long flags
;
3360 pc
= preempt_count();
3361 preempt_disable_notrace();
3362 cpu
= raw_smp_processor_id();
3363 disabled
= atomic_inc_return(&per_cpu(ftrace_test_event_disable
, cpu
));
3368 local_save_flags(flags
);
3370 event
= trace_current_buffer_lock_reserve(&buffer
,
3371 TRACE_FN
, sizeof(*entry
),
3375 entry
= ring_buffer_event_data(event
);
3377 entry
->parent_ip
= parent_ip
;
3379 trace_buffer_unlock_commit(event_tr
, buffer
, event
, flags
, pc
);
3382 atomic_dec(&per_cpu(ftrace_test_event_disable
, cpu
));
3383 preempt_enable_notrace();
3386 static struct ftrace_ops trace_ops __initdata
=
3388 .func
= function_test_events_call
,
3389 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
,
3392 static __init
void event_trace_self_test_with_function(void)
3395 event_tr
= top_trace_array();
3396 if (WARN_ON(!event_tr
))
3398 ret
= register_ftrace_function(&trace_ops
);
3399 if (WARN_ON(ret
< 0)) {
3400 pr_info("Failed to enable function tracer for event tests\n");
3403 pr_info("Running tests again, along with the function tracer\n");
3404 event_trace_self_tests();
3405 unregister_ftrace_function(&trace_ops
);
3408 static __init
void event_trace_self_test_with_function(void)
3413 static __init
int event_trace_self_tests_init(void)
3415 if (!tracing_selftest_disabled
) {
3416 event_trace_self_tests();
3417 event_trace_self_test_with_function();
3423 late_initcall(event_trace_self_tests_init
);