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 #include <linux/workqueue.h>
12 #include <linux/spinlock.h>
13 #include <linux/kthread.h>
14 #include <linux/debugfs.h>
15 #include <linux/uaccess.h>
16 #include <linux/module.h>
17 #include <linux/ctype.h>
18 #include <linux/slab.h>
19 #include <linux/delay.h>
21 #include <asm/setup.h>
23 #include "trace_output.h"
26 #define TRACE_SYSTEM "TRACE_SYSTEM"
28 DEFINE_MUTEX(event_mutex
);
30 LIST_HEAD(ftrace_events
);
31 static LIST_HEAD(ftrace_common_fields
);
33 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
35 static struct kmem_cache
*field_cachep
;
36 static struct kmem_cache
*file_cachep
;
38 #define SYSTEM_FL_FREE_NAME (1 << 31)
40 static inline int system_refcount(struct event_subsystem
*system
)
42 return system
->ref_count
& ~SYSTEM_FL_FREE_NAME
;
45 static int system_refcount_inc(struct event_subsystem
*system
)
47 return (system
->ref_count
++) & ~SYSTEM_FL_FREE_NAME
;
50 static int system_refcount_dec(struct event_subsystem
*system
)
52 return (--system
->ref_count
) & ~SYSTEM_FL_FREE_NAME
;
55 /* Double loops, do not use break, only goto's work */
56 #define do_for_each_event_file(tr, file) \
57 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
58 list_for_each_entry(file, &tr->events, list)
60 #define do_for_each_event_file_safe(tr, file) \
61 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
62 struct ftrace_event_file *___n; \
63 list_for_each_entry_safe(file, ___n, &tr->events, list)
65 #define while_for_each_event_file() \
68 static struct list_head
*
69 trace_get_fields(struct ftrace_event_call
*event_call
)
71 if (!event_call
->class->get_fields
)
72 return &event_call
->class->fields
;
73 return event_call
->class->get_fields(event_call
);
76 static struct ftrace_event_field
*
77 __find_event_field(struct list_head
*head
, char *name
)
79 struct ftrace_event_field
*field
;
81 list_for_each_entry(field
, head
, link
) {
82 if (!strcmp(field
->name
, name
))
89 struct ftrace_event_field
*
90 trace_find_event_field(struct ftrace_event_call
*call
, char *name
)
92 struct ftrace_event_field
*field
;
93 struct list_head
*head
;
95 field
= __find_event_field(&ftrace_common_fields
, name
);
99 head
= trace_get_fields(call
);
100 return __find_event_field(head
, name
);
103 static int __trace_define_field(struct list_head
*head
, const char *type
,
104 const char *name
, int offset
, int size
,
105 int is_signed
, int filter_type
)
107 struct ftrace_event_field
*field
;
109 field
= kmem_cache_alloc(field_cachep
, GFP_TRACE
);
116 if (filter_type
== FILTER_OTHER
)
117 field
->filter_type
= filter_assign_type(type
);
119 field
->filter_type
= filter_type
;
121 field
->offset
= offset
;
123 field
->is_signed
= is_signed
;
125 list_add(&field
->link
, head
);
130 int trace_define_field(struct ftrace_event_call
*call
, const char *type
,
131 const char *name
, int offset
, int size
, int is_signed
,
134 struct list_head
*head
;
136 if (WARN_ON(!call
->class))
139 head
= trace_get_fields(call
);
140 return __trace_define_field(head
, type
, name
, offset
, size
,
141 is_signed
, filter_type
);
143 EXPORT_SYMBOL_GPL(trace_define_field
);
145 #define __common_field(type, item) \
146 ret = __trace_define_field(&ftrace_common_fields, #type, \
148 offsetof(typeof(ent), item), \
150 is_signed_type(type), FILTER_OTHER); \
154 static int trace_define_common_fields(void)
157 struct trace_entry ent
;
159 __common_field(unsigned short, type
);
160 __common_field(unsigned char, flags
);
161 __common_field(unsigned char, preempt_count
);
162 __common_field(int, pid
);
167 static void trace_destroy_fields(struct ftrace_event_call
*call
)
169 struct ftrace_event_field
*field
, *next
;
170 struct list_head
*head
;
172 head
= trace_get_fields(call
);
173 list_for_each_entry_safe(field
, next
, head
, link
) {
174 list_del(&field
->link
);
175 kmem_cache_free(field_cachep
, field
);
179 int trace_event_raw_init(struct ftrace_event_call
*call
)
183 id
= register_ftrace_event(&call
->event
);
189 EXPORT_SYMBOL_GPL(trace_event_raw_init
);
191 void *ftrace_event_buffer_reserve(struct ftrace_event_buffer
*fbuffer
,
192 struct ftrace_event_file
*ftrace_file
,
195 struct ftrace_event_call
*event_call
= ftrace_file
->event_call
;
197 local_save_flags(fbuffer
->flags
);
198 fbuffer
->pc
= preempt_count();
199 fbuffer
->ftrace_file
= ftrace_file
;
202 trace_event_buffer_lock_reserve(&fbuffer
->buffer
, ftrace_file
,
203 event_call
->event
.type
, len
,
204 fbuffer
->flags
, fbuffer
->pc
);
208 fbuffer
->entry
= ring_buffer_event_data(fbuffer
->event
);
209 return fbuffer
->entry
;
211 EXPORT_SYMBOL_GPL(ftrace_event_buffer_reserve
);
213 void ftrace_event_buffer_commit(struct ftrace_event_buffer
*fbuffer
)
215 event_trigger_unlock_commit(fbuffer
->ftrace_file
, fbuffer
->buffer
,
216 fbuffer
->event
, fbuffer
->entry
,
217 fbuffer
->flags
, fbuffer
->pc
);
219 EXPORT_SYMBOL_GPL(ftrace_event_buffer_commit
);
221 int ftrace_event_reg(struct ftrace_event_call
*call
,
222 enum trace_reg type
, void *data
)
224 struct ftrace_event_file
*file
= data
;
226 WARN_ON(!(call
->flags
& TRACE_EVENT_FL_TRACEPOINT
));
228 case TRACE_REG_REGISTER
:
229 return tracepoint_probe_register(call
->tp
,
232 case TRACE_REG_UNREGISTER
:
233 tracepoint_probe_unregister(call
->tp
,
238 #ifdef CONFIG_PERF_EVENTS
239 case TRACE_REG_PERF_REGISTER
:
240 return tracepoint_probe_register(call
->tp
,
241 call
->class->perf_probe
,
243 case TRACE_REG_PERF_UNREGISTER
:
244 tracepoint_probe_unregister(call
->tp
,
245 call
->class->perf_probe
,
248 case TRACE_REG_PERF_OPEN
:
249 case TRACE_REG_PERF_CLOSE
:
250 case TRACE_REG_PERF_ADD
:
251 case TRACE_REG_PERF_DEL
:
257 EXPORT_SYMBOL_GPL(ftrace_event_reg
);
259 void trace_event_enable_cmd_record(bool enable
)
261 struct ftrace_event_file
*file
;
262 struct trace_array
*tr
;
264 mutex_lock(&event_mutex
);
265 do_for_each_event_file(tr
, file
) {
267 if (!(file
->flags
& FTRACE_EVENT_FL_ENABLED
))
271 tracing_start_cmdline_record();
272 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT
, &file
->flags
);
274 tracing_stop_cmdline_record();
275 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT
, &file
->flags
);
277 } while_for_each_event_file();
278 mutex_unlock(&event_mutex
);
281 static int __ftrace_event_enable_disable(struct ftrace_event_file
*file
,
282 int enable
, int soft_disable
)
284 struct ftrace_event_call
*call
= file
->event_call
;
291 * When soft_disable is set and enable is cleared, the sm_ref
292 * reference counter is decremented. If it reaches 0, we want
293 * to clear the SOFT_DISABLED flag but leave the event in the
294 * state that it was. That is, if the event was enabled and
295 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
296 * is set we do not want the event to be enabled before we
299 * When soft_disable is not set but the SOFT_MODE flag is,
300 * we do nothing. Do not disable the tracepoint, otherwise
301 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
304 if (atomic_dec_return(&file
->sm_ref
) > 0)
306 disable
= file
->flags
& FTRACE_EVENT_FL_SOFT_DISABLED
;
307 clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT
, &file
->flags
);
309 disable
= !(file
->flags
& FTRACE_EVENT_FL_SOFT_MODE
);
311 if (disable
&& (file
->flags
& FTRACE_EVENT_FL_ENABLED
)) {
312 clear_bit(FTRACE_EVENT_FL_ENABLED_BIT
, &file
->flags
);
313 if (file
->flags
& FTRACE_EVENT_FL_RECORDED_CMD
) {
314 tracing_stop_cmdline_record();
315 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT
, &file
->flags
);
317 call
->class->reg(call
, TRACE_REG_UNREGISTER
, file
);
319 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
320 if (file
->flags
& FTRACE_EVENT_FL_SOFT_MODE
)
321 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT
, &file
->flags
);
323 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT
, &file
->flags
);
327 * When soft_disable is set and enable is set, we want to
328 * register the tracepoint for the event, but leave the event
329 * as is. That means, if the event was already enabled, we do
330 * nothing (but set SOFT_MODE). If the event is disabled, we
331 * set SOFT_DISABLED before enabling the event tracepoint, so
332 * it still seems to be disabled.
335 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT
, &file
->flags
);
337 if (atomic_inc_return(&file
->sm_ref
) > 1)
339 set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT
, &file
->flags
);
342 if (!(file
->flags
& FTRACE_EVENT_FL_ENABLED
)) {
344 /* Keep the event disabled, when going to SOFT_MODE. */
346 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT
, &file
->flags
);
348 if (trace_flags
& TRACE_ITER_RECORD_CMD
) {
349 tracing_start_cmdline_record();
350 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT
, &file
->flags
);
352 ret
= call
->class->reg(call
, TRACE_REG_REGISTER
, file
);
354 tracing_stop_cmdline_record();
355 pr_info("event trace: Could not enable event "
356 "%s\n", ftrace_event_name(call
));
359 set_bit(FTRACE_EVENT_FL_ENABLED_BIT
, &file
->flags
);
361 /* WAS_ENABLED gets set but never cleared. */
362 call
->flags
|= TRACE_EVENT_FL_WAS_ENABLED
;
370 int trace_event_enable_disable(struct ftrace_event_file
*file
,
371 int enable
, int soft_disable
)
373 return __ftrace_event_enable_disable(file
, enable
, soft_disable
);
376 static int ftrace_event_enable_disable(struct ftrace_event_file
*file
,
379 return __ftrace_event_enable_disable(file
, enable
, 0);
382 static void ftrace_clear_events(struct trace_array
*tr
)
384 struct ftrace_event_file
*file
;
386 mutex_lock(&event_mutex
);
387 list_for_each_entry(file
, &tr
->events
, list
) {
388 ftrace_event_enable_disable(file
, 0);
390 mutex_unlock(&event_mutex
);
393 static void __put_system(struct event_subsystem
*system
)
395 struct event_filter
*filter
= system
->filter
;
397 WARN_ON_ONCE(system_refcount(system
) == 0);
398 if (system_refcount_dec(system
))
401 list_del(&system
->list
);
404 kfree(filter
->filter_string
);
407 if (system
->ref_count
& SYSTEM_FL_FREE_NAME
)
412 static void __get_system(struct event_subsystem
*system
)
414 WARN_ON_ONCE(system_refcount(system
) == 0);
415 system_refcount_inc(system
);
418 static void __get_system_dir(struct ftrace_subsystem_dir
*dir
)
420 WARN_ON_ONCE(dir
->ref_count
== 0);
422 __get_system(dir
->subsystem
);
425 static void __put_system_dir(struct ftrace_subsystem_dir
*dir
)
427 WARN_ON_ONCE(dir
->ref_count
== 0);
428 /* If the subsystem is about to be freed, the dir must be too */
429 WARN_ON_ONCE(system_refcount(dir
->subsystem
) == 1 && dir
->ref_count
!= 1);
431 __put_system(dir
->subsystem
);
432 if (!--dir
->ref_count
)
436 static void put_system(struct ftrace_subsystem_dir
*dir
)
438 mutex_lock(&event_mutex
);
439 __put_system_dir(dir
);
440 mutex_unlock(&event_mutex
);
443 static void remove_subsystem(struct ftrace_subsystem_dir
*dir
)
448 if (!--dir
->nr_events
) {
449 debugfs_remove_recursive(dir
->entry
);
450 list_del(&dir
->list
);
451 __put_system_dir(dir
);
455 static void remove_event_file_dir(struct ftrace_event_file
*file
)
457 struct dentry
*dir
= file
->dir
;
458 struct dentry
*child
;
461 spin_lock(&dir
->d_lock
); /* probably unneeded */
462 list_for_each_entry(child
, &dir
->d_subdirs
, d_u
.d_child
) {
463 if (child
->d_inode
) /* probably unneeded */
464 child
->d_inode
->i_private
= NULL
;
466 spin_unlock(&dir
->d_lock
);
468 debugfs_remove_recursive(dir
);
471 list_del(&file
->list
);
472 remove_subsystem(file
->system
);
473 kmem_cache_free(file_cachep
, file
);
477 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
480 __ftrace_set_clr_event_nolock(struct trace_array
*tr
, const char *match
,
481 const char *sub
, const char *event
, int set
)
483 struct ftrace_event_file
*file
;
484 struct ftrace_event_call
*call
;
488 list_for_each_entry(file
, &tr
->events
, list
) {
490 call
= file
->event_call
;
491 name
= ftrace_event_name(call
);
493 if (!name
|| !call
->class || !call
->class->reg
)
496 if (call
->flags
& TRACE_EVENT_FL_IGNORE_ENABLE
)
500 strcmp(match
, name
) != 0 &&
501 strcmp(match
, call
->class->system
) != 0)
504 if (sub
&& strcmp(sub
, call
->class->system
) != 0)
507 if (event
&& strcmp(event
, name
) != 0)
510 ftrace_event_enable_disable(file
, set
);
518 static int __ftrace_set_clr_event(struct trace_array
*tr
, const char *match
,
519 const char *sub
, const char *event
, int set
)
523 mutex_lock(&event_mutex
);
524 ret
= __ftrace_set_clr_event_nolock(tr
, match
, sub
, event
, set
);
525 mutex_unlock(&event_mutex
);
530 static int ftrace_set_clr_event(struct trace_array
*tr
, char *buf
, int set
)
532 char *event
= NULL
, *sub
= NULL
, *match
;
535 * The buf format can be <subsystem>:<event-name>
536 * *:<event-name> means any event by that name.
537 * :<event-name> is the same.
539 * <subsystem>:* means all events in that subsystem
540 * <subsystem>: means the same.
542 * <name> (no ':') means all events in a subsystem with
543 * the name <name> or any event that matches <name>
546 match
= strsep(&buf
, ":");
552 if (!strlen(sub
) || strcmp(sub
, "*") == 0)
554 if (!strlen(event
) || strcmp(event
, "*") == 0)
558 return __ftrace_set_clr_event(tr
, match
, sub
, event
, set
);
562 * trace_set_clr_event - enable or disable an event
563 * @system: system name to match (NULL for any system)
564 * @event: event name to match (NULL for all events, within system)
565 * @set: 1 to enable, 0 to disable
567 * This is a way for other parts of the kernel to enable or disable
570 * Returns 0 on success, -EINVAL if the parameters do not match any
573 int trace_set_clr_event(const char *system
, const char *event
, int set
)
575 struct trace_array
*tr
= top_trace_array();
577 return __ftrace_set_clr_event(tr
, NULL
, system
, event
, set
);
579 EXPORT_SYMBOL_GPL(trace_set_clr_event
);
581 /* 128 should be much more than enough */
582 #define EVENT_BUF_SIZE 127
585 ftrace_event_write(struct file
*file
, const char __user
*ubuf
,
586 size_t cnt
, loff_t
*ppos
)
588 struct trace_parser parser
;
589 struct seq_file
*m
= file
->private_data
;
590 struct trace_array
*tr
= m
->private;
596 ret
= tracing_update_buffers();
600 if (trace_parser_get_init(&parser
, EVENT_BUF_SIZE
+ 1))
603 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
605 if (read
>= 0 && trace_parser_loaded((&parser
))) {
608 if (*parser
.buffer
== '!')
611 parser
.buffer
[parser
.idx
] = 0;
613 ret
= ftrace_set_clr_event(tr
, parser
.buffer
+ !set
, set
);
621 trace_parser_put(&parser
);
627 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
629 struct ftrace_event_file
*file
= v
;
630 struct ftrace_event_call
*call
;
631 struct trace_array
*tr
= m
->private;
635 list_for_each_entry_continue(file
, &tr
->events
, list
) {
636 call
= file
->event_call
;
638 * The ftrace subsystem is for showing formats only.
639 * They can not be enabled or disabled via the event files.
641 if (call
->class && call
->class->reg
)
648 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
650 struct ftrace_event_file
*file
;
651 struct trace_array
*tr
= m
->private;
654 mutex_lock(&event_mutex
);
656 file
= list_entry(&tr
->events
, struct ftrace_event_file
, list
);
657 for (l
= 0; l
<= *pos
; ) {
658 file
= t_next(m
, file
, &l
);
666 s_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
668 struct ftrace_event_file
*file
= v
;
669 struct trace_array
*tr
= m
->private;
673 list_for_each_entry_continue(file
, &tr
->events
, list
) {
674 if (file
->flags
& FTRACE_EVENT_FL_ENABLED
)
681 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
683 struct ftrace_event_file
*file
;
684 struct trace_array
*tr
= m
->private;
687 mutex_lock(&event_mutex
);
689 file
= list_entry(&tr
->events
, struct ftrace_event_file
, list
);
690 for (l
= 0; l
<= *pos
; ) {
691 file
= s_next(m
, file
, &l
);
698 static int t_show(struct seq_file
*m
, void *v
)
700 struct ftrace_event_file
*file
= v
;
701 struct ftrace_event_call
*call
= file
->event_call
;
703 if (strcmp(call
->class->system
, TRACE_SYSTEM
) != 0)
704 seq_printf(m
, "%s:", call
->class->system
);
705 seq_printf(m
, "%s\n", ftrace_event_name(call
));
710 static void t_stop(struct seq_file
*m
, void *p
)
712 mutex_unlock(&event_mutex
);
716 event_enable_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
719 struct ftrace_event_file
*file
;
723 mutex_lock(&event_mutex
);
724 file
= event_file_data(filp
);
727 mutex_unlock(&event_mutex
);
732 if (flags
& FTRACE_EVENT_FL_ENABLED
&&
733 !(flags
& FTRACE_EVENT_FL_SOFT_DISABLED
))
736 if (flags
& FTRACE_EVENT_FL_SOFT_DISABLED
||
737 flags
& FTRACE_EVENT_FL_SOFT_MODE
)
742 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, strlen(buf
));
746 event_enable_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
749 struct ftrace_event_file
*file
;
753 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
757 ret
= tracing_update_buffers();
765 mutex_lock(&event_mutex
);
766 file
= event_file_data(filp
);
768 ret
= ftrace_event_enable_disable(file
, val
);
769 mutex_unlock(&event_mutex
);
778 return ret
? ret
: cnt
;
782 system_enable_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
785 const char set_to_char
[4] = { '?', '0', '1', 'X' };
786 struct ftrace_subsystem_dir
*dir
= filp
->private_data
;
787 struct event_subsystem
*system
= dir
->subsystem
;
788 struct ftrace_event_call
*call
;
789 struct ftrace_event_file
*file
;
790 struct trace_array
*tr
= dir
->tr
;
795 mutex_lock(&event_mutex
);
796 list_for_each_entry(file
, &tr
->events
, list
) {
797 call
= file
->event_call
;
798 if (!ftrace_event_name(call
) || !call
->class || !call
->class->reg
)
801 if (system
&& strcmp(call
->class->system
, system
->name
) != 0)
805 * We need to find out if all the events are set
806 * or if all events or cleared, or if we have
809 set
|= (1 << !!(file
->flags
& FTRACE_EVENT_FL_ENABLED
));
812 * If we have a mixture, no need to look further.
817 mutex_unlock(&event_mutex
);
819 buf
[0] = set_to_char
[set
];
822 ret
= simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, 2);
828 system_enable_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
831 struct ftrace_subsystem_dir
*dir
= filp
->private_data
;
832 struct event_subsystem
*system
= dir
->subsystem
;
833 const char *name
= NULL
;
837 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
841 ret
= tracing_update_buffers();
845 if (val
!= 0 && val
!= 1)
849 * Opening of "enable" adds a ref count to system,
850 * so the name is safe to use.
855 ret
= __ftrace_set_clr_event(dir
->tr
, NULL
, name
, NULL
, val
);
869 FORMAT_FIELD_SEPERATOR
= 2,
873 static void *f_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
875 struct ftrace_event_call
*call
= event_file_data(m
->private);
876 struct list_head
*common_head
= &ftrace_common_fields
;
877 struct list_head
*head
= trace_get_fields(call
);
878 struct list_head
*node
= v
;
882 switch ((unsigned long)v
) {
887 case FORMAT_FIELD_SEPERATOR
:
891 case FORMAT_PRINTFMT
:
897 if (node
== common_head
)
898 return (void *)FORMAT_FIELD_SEPERATOR
;
899 else if (node
== head
)
900 return (void *)FORMAT_PRINTFMT
;
905 static int f_show(struct seq_file
*m
, void *v
)
907 struct ftrace_event_call
*call
= event_file_data(m
->private);
908 struct ftrace_event_field
*field
;
909 const char *array_descriptor
;
911 switch ((unsigned long)v
) {
913 seq_printf(m
, "name: %s\n", ftrace_event_name(call
));
914 seq_printf(m
, "ID: %d\n", call
->event
.type
);
915 seq_printf(m
, "format:\n");
918 case FORMAT_FIELD_SEPERATOR
:
922 case FORMAT_PRINTFMT
:
923 seq_printf(m
, "\nprint fmt: %s\n",
928 field
= list_entry(v
, struct ftrace_event_field
, link
);
930 * Smartly shows the array type(except dynamic array).
933 * If TYPE := TYPE[LEN], it is shown:
934 * field:TYPE VAR[LEN]
936 array_descriptor
= strchr(field
->type
, '[');
938 if (!strncmp(field
->type
, "__data_loc", 10))
939 array_descriptor
= NULL
;
941 if (!array_descriptor
)
942 seq_printf(m
, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
943 field
->type
, field
->name
, field
->offset
,
944 field
->size
, !!field
->is_signed
);
946 seq_printf(m
, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
947 (int)(array_descriptor
- field
->type
),
948 field
->type
, field
->name
,
949 array_descriptor
, field
->offset
,
950 field
->size
, !!field
->is_signed
);
955 static void *f_start(struct seq_file
*m
, loff_t
*pos
)
957 void *p
= (void *)FORMAT_HEADER
;
960 /* ->stop() is called even if ->start() fails */
961 mutex_lock(&event_mutex
);
962 if (!event_file_data(m
->private))
963 return ERR_PTR(-ENODEV
);
965 while (l
< *pos
&& p
)
966 p
= f_next(m
, p
, &l
);
971 static void f_stop(struct seq_file
*m
, void *p
)
973 mutex_unlock(&event_mutex
);
976 static const struct seq_operations trace_format_seq_ops
= {
983 static int trace_format_open(struct inode
*inode
, struct file
*file
)
988 ret
= seq_open(file
, &trace_format_seq_ops
);
992 m
= file
->private_data
;
999 event_id_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
, loff_t
*ppos
)
1001 int id
= (long)event_file_data(filp
);
1011 len
= sprintf(buf
, "%d\n", id
);
1013 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, len
);
1017 event_filter_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
1020 struct ftrace_event_file
*file
;
1021 struct trace_seq
*s
;
1027 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
1034 mutex_lock(&event_mutex
);
1035 file
= event_file_data(filp
);
1037 print_event_filter(file
, s
);
1038 mutex_unlock(&event_mutex
);
1041 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, s
->buffer
, s
->len
);
1049 event_filter_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
1052 struct ftrace_event_file
*file
;
1056 if (cnt
>= PAGE_SIZE
)
1059 buf
= (char *)__get_free_page(GFP_TEMPORARY
);
1063 if (copy_from_user(buf
, ubuf
, cnt
)) {
1064 free_page((unsigned long) buf
);
1069 mutex_lock(&event_mutex
);
1070 file
= event_file_data(filp
);
1072 err
= apply_event_filter(file
, buf
);
1073 mutex_unlock(&event_mutex
);
1075 free_page((unsigned long) buf
);
1084 static LIST_HEAD(event_subsystems
);
1086 static int subsystem_open(struct inode
*inode
, struct file
*filp
)
1088 struct event_subsystem
*system
= NULL
;
1089 struct ftrace_subsystem_dir
*dir
= NULL
; /* Initialize for gcc */
1090 struct trace_array
*tr
;
1093 if (tracing_is_disabled())
1096 /* Make sure the system still exists */
1097 mutex_lock(&trace_types_lock
);
1098 mutex_lock(&event_mutex
);
1099 list_for_each_entry(tr
, &ftrace_trace_arrays
, list
) {
1100 list_for_each_entry(dir
, &tr
->systems
, list
) {
1101 if (dir
== inode
->i_private
) {
1102 /* Don't open systems with no events */
1103 if (dir
->nr_events
) {
1104 __get_system_dir(dir
);
1105 system
= dir
->subsystem
;
1112 mutex_unlock(&event_mutex
);
1113 mutex_unlock(&trace_types_lock
);
1118 /* Some versions of gcc think dir can be uninitialized here */
1121 /* Still need to increment the ref count of the system */
1122 if (trace_array_get(tr
) < 0) {
1127 ret
= tracing_open_generic(inode
, filp
);
1129 trace_array_put(tr
);
1136 static int system_tr_open(struct inode
*inode
, struct file
*filp
)
1138 struct ftrace_subsystem_dir
*dir
;
1139 struct trace_array
*tr
= inode
->i_private
;
1142 if (tracing_is_disabled())
1145 if (trace_array_get(tr
) < 0)
1148 /* Make a temporary dir that has no system but points to tr */
1149 dir
= kzalloc(sizeof(*dir
), GFP_KERNEL
);
1151 trace_array_put(tr
);
1157 ret
= tracing_open_generic(inode
, filp
);
1159 trace_array_put(tr
);
1164 filp
->private_data
= dir
;
1169 static int subsystem_release(struct inode
*inode
, struct file
*file
)
1171 struct ftrace_subsystem_dir
*dir
= file
->private_data
;
1173 trace_array_put(dir
->tr
);
1176 * If dir->subsystem is NULL, then this is a temporary
1177 * descriptor that was made for a trace_array to enable
1189 subsystem_filter_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
1192 struct ftrace_subsystem_dir
*dir
= filp
->private_data
;
1193 struct event_subsystem
*system
= dir
->subsystem
;
1194 struct trace_seq
*s
;
1200 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
1206 print_subsystem_event_filter(system
, s
);
1207 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, s
->buffer
, s
->len
);
1215 subsystem_filter_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
1218 struct ftrace_subsystem_dir
*dir
= filp
->private_data
;
1222 if (cnt
>= PAGE_SIZE
)
1225 buf
= (char *)__get_free_page(GFP_TEMPORARY
);
1229 if (copy_from_user(buf
, ubuf
, cnt
)) {
1230 free_page((unsigned long) buf
);
1235 err
= apply_subsystem_event_filter(dir
, buf
);
1236 free_page((unsigned long) buf
);
1246 show_header(struct file
*filp
, char __user
*ubuf
, size_t cnt
, loff_t
*ppos
)
1248 int (*func
)(struct trace_seq
*s
) = filp
->private_data
;
1249 struct trace_seq
*s
;
1255 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
1262 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, s
->buffer
, s
->len
);
1269 static int ftrace_event_avail_open(struct inode
*inode
, struct file
*file
);
1270 static int ftrace_event_set_open(struct inode
*inode
, struct file
*file
);
1271 static int ftrace_event_release(struct inode
*inode
, struct file
*file
);
1273 static const struct seq_operations show_event_seq_ops
= {
1280 static const struct seq_operations show_set_event_seq_ops
= {
1287 static const struct file_operations ftrace_avail_fops
= {
1288 .open
= ftrace_event_avail_open
,
1290 .llseek
= seq_lseek
,
1291 .release
= seq_release
,
1294 static const struct file_operations ftrace_set_event_fops
= {
1295 .open
= ftrace_event_set_open
,
1297 .write
= ftrace_event_write
,
1298 .llseek
= seq_lseek
,
1299 .release
= ftrace_event_release
,
1302 static const struct file_operations ftrace_enable_fops
= {
1303 .open
= tracing_open_generic
,
1304 .read
= event_enable_read
,
1305 .write
= event_enable_write
,
1306 .llseek
= default_llseek
,
1309 static const struct file_operations ftrace_event_format_fops
= {
1310 .open
= trace_format_open
,
1312 .llseek
= seq_lseek
,
1313 .release
= seq_release
,
1316 static const struct file_operations ftrace_event_id_fops
= {
1317 .read
= event_id_read
,
1318 .llseek
= default_llseek
,
1321 static const struct file_operations ftrace_event_filter_fops
= {
1322 .open
= tracing_open_generic
,
1323 .read
= event_filter_read
,
1324 .write
= event_filter_write
,
1325 .llseek
= default_llseek
,
1328 static const struct file_operations ftrace_subsystem_filter_fops
= {
1329 .open
= subsystem_open
,
1330 .read
= subsystem_filter_read
,
1331 .write
= subsystem_filter_write
,
1332 .llseek
= default_llseek
,
1333 .release
= subsystem_release
,
1336 static const struct file_operations ftrace_system_enable_fops
= {
1337 .open
= subsystem_open
,
1338 .read
= system_enable_read
,
1339 .write
= system_enable_write
,
1340 .llseek
= default_llseek
,
1341 .release
= subsystem_release
,
1344 static const struct file_operations ftrace_tr_enable_fops
= {
1345 .open
= system_tr_open
,
1346 .read
= system_enable_read
,
1347 .write
= system_enable_write
,
1348 .llseek
= default_llseek
,
1349 .release
= subsystem_release
,
1352 static const struct file_operations ftrace_show_header_fops
= {
1353 .open
= tracing_open_generic
,
1354 .read
= show_header
,
1355 .llseek
= default_llseek
,
1359 ftrace_event_open(struct inode
*inode
, struct file
*file
,
1360 const struct seq_operations
*seq_ops
)
1365 ret
= seq_open(file
, seq_ops
);
1368 m
= file
->private_data
;
1369 /* copy tr over to seq ops */
1370 m
->private = inode
->i_private
;
1375 static int ftrace_event_release(struct inode
*inode
, struct file
*file
)
1377 struct trace_array
*tr
= inode
->i_private
;
1379 trace_array_put(tr
);
1381 return seq_release(inode
, file
);
1385 ftrace_event_avail_open(struct inode
*inode
, struct file
*file
)
1387 const struct seq_operations
*seq_ops
= &show_event_seq_ops
;
1389 return ftrace_event_open(inode
, file
, seq_ops
);
1393 ftrace_event_set_open(struct inode
*inode
, struct file
*file
)
1395 const struct seq_operations
*seq_ops
= &show_set_event_seq_ops
;
1396 struct trace_array
*tr
= inode
->i_private
;
1399 if (trace_array_get(tr
) < 0)
1402 if ((file
->f_mode
& FMODE_WRITE
) &&
1403 (file
->f_flags
& O_TRUNC
))
1404 ftrace_clear_events(tr
);
1406 ret
= ftrace_event_open(inode
, file
, seq_ops
);
1408 trace_array_put(tr
);
1412 static struct event_subsystem
*
1413 create_new_subsystem(const char *name
)
1415 struct event_subsystem
*system
;
1417 /* need to create new entry */
1418 system
= kmalloc(sizeof(*system
), GFP_KERNEL
);
1422 system
->ref_count
= 1;
1424 /* Only allocate if dynamic (kprobes and modules) */
1425 if (!core_kernel_data((unsigned long)name
)) {
1426 system
->ref_count
|= SYSTEM_FL_FREE_NAME
;
1427 system
->name
= kstrdup(name
, GFP_KERNEL
);
1431 system
->name
= name
;
1433 system
->filter
= NULL
;
1435 system
->filter
= kzalloc(sizeof(struct event_filter
), GFP_KERNEL
);
1436 if (!system
->filter
)
1439 list_add(&system
->list
, &event_subsystems
);
1444 if (system
->ref_count
& SYSTEM_FL_FREE_NAME
)
1445 kfree(system
->name
);
1450 static struct dentry
*
1451 event_subsystem_dir(struct trace_array
*tr
, const char *name
,
1452 struct ftrace_event_file
*file
, struct dentry
*parent
)
1454 struct ftrace_subsystem_dir
*dir
;
1455 struct event_subsystem
*system
;
1456 struct dentry
*entry
;
1458 /* First see if we did not already create this dir */
1459 list_for_each_entry(dir
, &tr
->systems
, list
) {
1460 system
= dir
->subsystem
;
1461 if (strcmp(system
->name
, name
) == 0) {
1468 /* Now see if the system itself exists. */
1469 list_for_each_entry(system
, &event_subsystems
, list
) {
1470 if (strcmp(system
->name
, name
) == 0)
1473 /* Reset system variable when not found */
1474 if (&system
->list
== &event_subsystems
)
1477 dir
= kmalloc(sizeof(*dir
), GFP_KERNEL
);
1482 system
= create_new_subsystem(name
);
1486 __get_system(system
);
1488 dir
->entry
= debugfs_create_dir(name
, parent
);
1490 pr_warning("Failed to create system directory %s\n", name
);
1491 __put_system(system
);
1498 dir
->subsystem
= system
;
1501 entry
= debugfs_create_file("filter", 0644, dir
->entry
, dir
,
1502 &ftrace_subsystem_filter_fops
);
1504 kfree(system
->filter
);
1505 system
->filter
= NULL
;
1506 pr_warning("Could not create debugfs '%s/filter' entry\n", name
);
1509 trace_create_file("enable", 0644, dir
->entry
, dir
,
1510 &ftrace_system_enable_fops
);
1512 list_add(&dir
->list
, &tr
->systems
);
1519 /* Only print this message if failed on memory allocation */
1520 if (!dir
|| !system
)
1521 pr_warning("No memory to create event subsystem %s\n",
1527 event_create_dir(struct dentry
*parent
, struct ftrace_event_file
*file
)
1529 struct ftrace_event_call
*call
= file
->event_call
;
1530 struct trace_array
*tr
= file
->tr
;
1531 struct list_head
*head
;
1532 struct dentry
*d_events
;
1537 * If the trace point header did not define TRACE_SYSTEM
1538 * then the system would be called "TRACE_SYSTEM".
1540 if (strcmp(call
->class->system
, TRACE_SYSTEM
) != 0) {
1541 d_events
= event_subsystem_dir(tr
, call
->class->system
, file
, parent
);
1547 name
= ftrace_event_name(call
);
1548 file
->dir
= debugfs_create_dir(name
, d_events
);
1550 pr_warning("Could not create debugfs '%s' directory\n",
1555 if (call
->class->reg
&& !(call
->flags
& TRACE_EVENT_FL_IGNORE_ENABLE
))
1556 trace_create_file("enable", 0644, file
->dir
, file
,
1557 &ftrace_enable_fops
);
1559 #ifdef CONFIG_PERF_EVENTS
1560 if (call
->event
.type
&& call
->class->reg
)
1561 trace_create_file("id", 0444, file
->dir
,
1562 (void *)(long)call
->event
.type
,
1563 &ftrace_event_id_fops
);
1567 * Other events may have the same class. Only update
1568 * the fields if they are not already defined.
1570 head
= trace_get_fields(call
);
1571 if (list_empty(head
)) {
1572 ret
= call
->class->define_fields(call
);
1574 pr_warning("Could not initialize trace point"
1575 " events/%s\n", name
);
1579 trace_create_file("filter", 0644, file
->dir
, file
,
1580 &ftrace_event_filter_fops
);
1582 trace_create_file("trigger", 0644, file
->dir
, file
,
1583 &event_trigger_fops
);
1585 trace_create_file("format", 0444, file
->dir
, call
,
1586 &ftrace_event_format_fops
);
1591 static void remove_event_from_tracers(struct ftrace_event_call
*call
)
1593 struct ftrace_event_file
*file
;
1594 struct trace_array
*tr
;
1596 do_for_each_event_file_safe(tr
, file
) {
1597 if (file
->event_call
!= call
)
1600 remove_event_file_dir(file
);
1602 * The do_for_each_event_file_safe() is
1603 * a double loop. After finding the call for this
1604 * trace_array, we use break to jump to the next
1608 } while_for_each_event_file();
1611 static void event_remove(struct ftrace_event_call
*call
)
1613 struct trace_array
*tr
;
1614 struct ftrace_event_file
*file
;
1616 do_for_each_event_file(tr
, file
) {
1617 if (file
->event_call
!= call
)
1619 ftrace_event_enable_disable(file
, 0);
1620 destroy_preds(file
);
1622 * The do_for_each_event_file() is
1623 * a double loop. After finding the call for this
1624 * trace_array, we use break to jump to the next
1628 } while_for_each_event_file();
1630 if (call
->event
.funcs
)
1631 __unregister_ftrace_event(&call
->event
);
1632 remove_event_from_tracers(call
);
1633 list_del(&call
->list
);
1636 static int event_init(struct ftrace_event_call
*call
)
1641 name
= ftrace_event_name(call
);
1645 if (call
->class->raw_init
) {
1646 ret
= call
->class->raw_init(call
);
1647 if (ret
< 0 && ret
!= -ENOSYS
)
1648 pr_warn("Could not initialize trace events/%s\n",
1656 __register_event(struct ftrace_event_call
*call
, struct module
*mod
)
1660 ret
= event_init(call
);
1664 list_add(&call
->list
, &ftrace_events
);
1670 static struct ftrace_event_file
*
1671 trace_create_new_event(struct ftrace_event_call
*call
,
1672 struct trace_array
*tr
)
1674 struct ftrace_event_file
*file
;
1676 file
= kmem_cache_alloc(file_cachep
, GFP_TRACE
);
1680 file
->event_call
= call
;
1682 atomic_set(&file
->sm_ref
, 0);
1683 atomic_set(&file
->tm_ref
, 0);
1684 INIT_LIST_HEAD(&file
->triggers
);
1685 list_add(&file
->list
, &tr
->events
);
1690 /* Add an event to a trace directory */
1692 __trace_add_new_event(struct ftrace_event_call
*call
, struct trace_array
*tr
)
1694 struct ftrace_event_file
*file
;
1696 file
= trace_create_new_event(call
, tr
);
1700 return event_create_dir(tr
->event_dir
, file
);
1704 * Just create a decriptor for early init. A descriptor is required
1705 * for enabling events at boot. We want to enable events before
1706 * the filesystem is initialized.
1709 __trace_early_add_new_event(struct ftrace_event_call
*call
,
1710 struct trace_array
*tr
)
1712 struct ftrace_event_file
*file
;
1714 file
= trace_create_new_event(call
, tr
);
1721 struct ftrace_module_file_ops
;
1722 static void __add_event_to_tracers(struct ftrace_event_call
*call
);
1724 /* Add an additional event_call dynamically */
1725 int trace_add_event_call(struct ftrace_event_call
*call
)
1728 mutex_lock(&trace_types_lock
);
1729 mutex_lock(&event_mutex
);
1731 ret
= __register_event(call
, NULL
);
1733 __add_event_to_tracers(call
);
1735 mutex_unlock(&event_mutex
);
1736 mutex_unlock(&trace_types_lock
);
1741 * Must be called under locking of trace_types_lock, event_mutex and
1744 static void __trace_remove_event_call(struct ftrace_event_call
*call
)
1747 trace_destroy_fields(call
);
1748 destroy_call_preds(call
);
1751 static int probe_remove_event_call(struct ftrace_event_call
*call
)
1753 struct trace_array
*tr
;
1754 struct ftrace_event_file
*file
;
1756 #ifdef CONFIG_PERF_EVENTS
1757 if (call
->perf_refcount
)
1760 do_for_each_event_file(tr
, file
) {
1761 if (file
->event_call
!= call
)
1764 * We can't rely on ftrace_event_enable_disable(enable => 0)
1765 * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
1766 * TRACE_REG_UNREGISTER.
1768 if (file
->flags
& FTRACE_EVENT_FL_ENABLED
)
1771 * The do_for_each_event_file_safe() is
1772 * a double loop. After finding the call for this
1773 * trace_array, we use break to jump to the next
1777 } while_for_each_event_file();
1779 __trace_remove_event_call(call
);
1784 /* Remove an event_call */
1785 int trace_remove_event_call(struct ftrace_event_call
*call
)
1789 mutex_lock(&trace_types_lock
);
1790 mutex_lock(&event_mutex
);
1791 down_write(&trace_event_sem
);
1792 ret
= probe_remove_event_call(call
);
1793 up_write(&trace_event_sem
);
1794 mutex_unlock(&event_mutex
);
1795 mutex_unlock(&trace_types_lock
);
1800 #define for_each_event(event, start, end) \
1801 for (event = start; \
1802 (unsigned long)event < (unsigned long)end; \
1805 #ifdef CONFIG_MODULES
1807 static void trace_module_add_events(struct module
*mod
)
1809 struct ftrace_event_call
**call
, **start
, **end
;
1811 if (!mod
->num_trace_events
)
1814 /* Don't add infrastructure for mods without tracepoints */
1815 if (trace_module_has_bad_taint(mod
)) {
1816 pr_err("%s: module has bad taint, not creating trace events\n",
1821 start
= mod
->trace_events
;
1822 end
= mod
->trace_events
+ mod
->num_trace_events
;
1824 for_each_event(call
, start
, end
) {
1825 __register_event(*call
, mod
);
1826 __add_event_to_tracers(*call
);
1830 static void trace_module_remove_events(struct module
*mod
)
1832 struct ftrace_event_call
*call
, *p
;
1833 bool clear_trace
= false;
1835 down_write(&trace_event_sem
);
1836 list_for_each_entry_safe(call
, p
, &ftrace_events
, list
) {
1837 if (call
->mod
== mod
) {
1838 if (call
->flags
& TRACE_EVENT_FL_WAS_ENABLED
)
1840 __trace_remove_event_call(call
);
1843 up_write(&trace_event_sem
);
1846 * It is safest to reset the ring buffer if the module being unloaded
1847 * registered any events that were used. The only worry is if
1848 * a new module gets loaded, and takes on the same id as the events
1849 * of this module. When printing out the buffer, traced events left
1850 * over from this module may be passed to the new module events and
1851 * unexpected results may occur.
1854 tracing_reset_all_online_cpus();
1857 static int trace_module_notify(struct notifier_block
*self
,
1858 unsigned long val
, void *data
)
1860 struct module
*mod
= data
;
1862 mutex_lock(&trace_types_lock
);
1863 mutex_lock(&event_mutex
);
1865 case MODULE_STATE_COMING
:
1866 trace_module_add_events(mod
);
1868 case MODULE_STATE_GOING
:
1869 trace_module_remove_events(mod
);
1872 mutex_unlock(&event_mutex
);
1873 mutex_unlock(&trace_types_lock
);
1878 static struct notifier_block trace_module_nb
= {
1879 .notifier_call
= trace_module_notify
,
1882 #endif /* CONFIG_MODULES */
1884 /* Create a new event directory structure for a trace directory. */
1886 __trace_add_event_dirs(struct trace_array
*tr
)
1888 struct ftrace_event_call
*call
;
1891 list_for_each_entry(call
, &ftrace_events
, list
) {
1892 ret
= __trace_add_new_event(call
, tr
);
1894 pr_warning("Could not create directory for event %s\n",
1895 ftrace_event_name(call
));
1899 struct ftrace_event_file
*
1900 find_event_file(struct trace_array
*tr
, const char *system
, const char *event
)
1902 struct ftrace_event_file
*file
;
1903 struct ftrace_event_call
*call
;
1906 list_for_each_entry(file
, &tr
->events
, list
) {
1908 call
= file
->event_call
;
1909 name
= ftrace_event_name(call
);
1911 if (!name
|| !call
->class || !call
->class->reg
)
1914 if (call
->flags
& TRACE_EVENT_FL_IGNORE_ENABLE
)
1917 if (strcmp(event
, name
) == 0 &&
1918 strcmp(system
, call
->class->system
) == 0)
1924 #ifdef CONFIG_DYNAMIC_FTRACE
1927 #define ENABLE_EVENT_STR "enable_event"
1928 #define DISABLE_EVENT_STR "disable_event"
1930 struct event_probe_data
{
1931 struct ftrace_event_file
*file
;
1932 unsigned long count
;
1938 event_enable_probe(unsigned long ip
, unsigned long parent_ip
, void **_data
)
1940 struct event_probe_data
**pdata
= (struct event_probe_data
**)_data
;
1941 struct event_probe_data
*data
= *pdata
;
1947 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT
, &data
->file
->flags
);
1949 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT
, &data
->file
->flags
);
1953 event_enable_count_probe(unsigned long ip
, unsigned long parent_ip
, void **_data
)
1955 struct event_probe_data
**pdata
= (struct event_probe_data
**)_data
;
1956 struct event_probe_data
*data
= *pdata
;
1964 /* Skip if the event is in a state we want to switch to */
1965 if (data
->enable
== !(data
->file
->flags
& FTRACE_EVENT_FL_SOFT_DISABLED
))
1968 if (data
->count
!= -1)
1971 event_enable_probe(ip
, parent_ip
, _data
);
1975 event_enable_print(struct seq_file
*m
, unsigned long ip
,
1976 struct ftrace_probe_ops
*ops
, void *_data
)
1978 struct event_probe_data
*data
= _data
;
1980 seq_printf(m
, "%ps:", (void *)ip
);
1982 seq_printf(m
, "%s:%s:%s",
1983 data
->enable
? ENABLE_EVENT_STR
: DISABLE_EVENT_STR
,
1984 data
->file
->event_call
->class->system
,
1985 ftrace_event_name(data
->file
->event_call
));
1987 if (data
->count
== -1)
1988 seq_printf(m
, ":unlimited\n");
1990 seq_printf(m
, ":count=%ld\n", data
->count
);
1996 event_enable_init(struct ftrace_probe_ops
*ops
, unsigned long ip
,
1999 struct event_probe_data
**pdata
= (struct event_probe_data
**)_data
;
2000 struct event_probe_data
*data
= *pdata
;
2007 event_enable_free(struct ftrace_probe_ops
*ops
, unsigned long ip
,
2010 struct event_probe_data
**pdata
= (struct event_probe_data
**)_data
;
2011 struct event_probe_data
*data
= *pdata
;
2013 if (WARN_ON_ONCE(data
->ref
<= 0))
2018 /* Remove the SOFT_MODE flag */
2019 __ftrace_event_enable_disable(data
->file
, 0, 1);
2020 module_put(data
->file
->event_call
->mod
);
2026 static struct ftrace_probe_ops event_enable_probe_ops
= {
2027 .func
= event_enable_probe
,
2028 .print
= event_enable_print
,
2029 .init
= event_enable_init
,
2030 .free
= event_enable_free
,
2033 static struct ftrace_probe_ops event_enable_count_probe_ops
= {
2034 .func
= event_enable_count_probe
,
2035 .print
= event_enable_print
,
2036 .init
= event_enable_init
,
2037 .free
= event_enable_free
,
2040 static struct ftrace_probe_ops event_disable_probe_ops
= {
2041 .func
= event_enable_probe
,
2042 .print
= event_enable_print
,
2043 .init
= event_enable_init
,
2044 .free
= event_enable_free
,
2047 static struct ftrace_probe_ops event_disable_count_probe_ops
= {
2048 .func
= event_enable_count_probe
,
2049 .print
= event_enable_print
,
2050 .init
= event_enable_init
,
2051 .free
= event_enable_free
,
2055 event_enable_func(struct ftrace_hash
*hash
,
2056 char *glob
, char *cmd
, char *param
, int enabled
)
2058 struct trace_array
*tr
= top_trace_array();
2059 struct ftrace_event_file
*file
;
2060 struct ftrace_probe_ops
*ops
;
2061 struct event_probe_data
*data
;
2068 /* hash funcs only work with set_ftrace_filter */
2069 if (!enabled
|| !param
)
2072 system
= strsep(¶m
, ":");
2076 event
= strsep(¶m
, ":");
2078 mutex_lock(&event_mutex
);
2081 file
= find_event_file(tr
, system
, event
);
2085 enable
= strcmp(cmd
, ENABLE_EVENT_STR
) == 0;
2088 ops
= param
? &event_enable_count_probe_ops
: &event_enable_probe_ops
;
2090 ops
= param
? &event_disable_count_probe_ops
: &event_disable_probe_ops
;
2092 if (glob
[0] == '!') {
2093 unregister_ftrace_function_probe_func(glob
+1, ops
);
2099 data
= kzalloc(sizeof(*data
), GFP_KERNEL
);
2103 data
->enable
= enable
;
2110 number
= strsep(¶m
, ":");
2113 if (!strlen(number
))
2117 * We use the callback data field (which is a pointer)
2120 ret
= kstrtoul(number
, 0, &data
->count
);
2125 /* Don't let event modules unload while probe registered */
2126 ret
= try_module_get(file
->event_call
->mod
);
2132 ret
= __ftrace_event_enable_disable(file
, 1, 1);
2135 ret
= register_ftrace_function_probe(glob
, ops
, data
);
2137 * The above returns on success the # of functions enabled,
2138 * but if it didn't find any functions it returns zero.
2139 * Consider no functions a failure too.
2146 /* Just return zero, not the number of enabled functions */
2149 mutex_unlock(&event_mutex
);
2153 __ftrace_event_enable_disable(file
, 0, 1);
2155 module_put(file
->event_call
->mod
);
2161 static struct ftrace_func_command event_enable_cmd
= {
2162 .name
= ENABLE_EVENT_STR
,
2163 .func
= event_enable_func
,
2166 static struct ftrace_func_command event_disable_cmd
= {
2167 .name
= DISABLE_EVENT_STR
,
2168 .func
= event_enable_func
,
2171 static __init
int register_event_cmds(void)
2175 ret
= register_ftrace_command(&event_enable_cmd
);
2176 if (WARN_ON(ret
< 0))
2178 ret
= register_ftrace_command(&event_disable_cmd
);
2179 if (WARN_ON(ret
< 0))
2180 unregister_ftrace_command(&event_enable_cmd
);
2184 static inline int register_event_cmds(void) { return 0; }
2185 #endif /* CONFIG_DYNAMIC_FTRACE */
2188 * The top level array has already had its ftrace_event_file
2189 * descriptors created in order to allow for early events to
2190 * be recorded. This function is called after the debugfs has been
2191 * initialized, and we now have to create the files associated
2195 __trace_early_add_event_dirs(struct trace_array
*tr
)
2197 struct ftrace_event_file
*file
;
2201 list_for_each_entry(file
, &tr
->events
, list
) {
2202 ret
= event_create_dir(tr
->event_dir
, file
);
2204 pr_warning("Could not create directory for event %s\n",
2205 ftrace_event_name(file
->event_call
));
2210 * For early boot up, the top trace array requires to have
2211 * a list of events that can be enabled. This must be done before
2212 * the filesystem is set up in order to allow events to be traced
2216 __trace_early_add_events(struct trace_array
*tr
)
2218 struct ftrace_event_call
*call
;
2221 list_for_each_entry(call
, &ftrace_events
, list
) {
2222 /* Early boot up should not have any modules loaded */
2223 if (WARN_ON_ONCE(call
->mod
))
2226 ret
= __trace_early_add_new_event(call
, tr
);
2228 pr_warning("Could not create early event %s\n",
2229 ftrace_event_name(call
));
2233 /* Remove the event directory structure for a trace directory. */
2235 __trace_remove_event_dirs(struct trace_array
*tr
)
2237 struct ftrace_event_file
*file
, *next
;
2239 list_for_each_entry_safe(file
, next
, &tr
->events
, list
)
2240 remove_event_file_dir(file
);
2243 static void __add_event_to_tracers(struct ftrace_event_call
*call
)
2245 struct trace_array
*tr
;
2247 list_for_each_entry(tr
, &ftrace_trace_arrays
, list
)
2248 __trace_add_new_event(call
, tr
);
2251 extern struct ftrace_event_call
*__start_ftrace_events
[];
2252 extern struct ftrace_event_call
*__stop_ftrace_events
[];
2254 static char bootup_event_buf
[COMMAND_LINE_SIZE
] __initdata
;
2256 static __init
int setup_trace_event(char *str
)
2258 strlcpy(bootup_event_buf
, str
, COMMAND_LINE_SIZE
);
2259 ring_buffer_expanded
= true;
2260 tracing_selftest_disabled
= true;
2264 __setup("trace_event=", setup_trace_event
);
2266 /* Expects to have event_mutex held when called */
2268 create_event_toplevel_files(struct dentry
*parent
, struct trace_array
*tr
)
2270 struct dentry
*d_events
;
2271 struct dentry
*entry
;
2273 entry
= debugfs_create_file("set_event", 0644, parent
,
2274 tr
, &ftrace_set_event_fops
);
2276 pr_warning("Could not create debugfs 'set_event' entry\n");
2280 d_events
= debugfs_create_dir("events", parent
);
2282 pr_warning("Could not create debugfs 'events' directory\n");
2286 /* ring buffer internal formats */
2287 trace_create_file("header_page", 0444, d_events
,
2288 ring_buffer_print_page_header
,
2289 &ftrace_show_header_fops
);
2291 trace_create_file("header_event", 0444, d_events
,
2292 ring_buffer_print_entry_header
,
2293 &ftrace_show_header_fops
);
2295 trace_create_file("enable", 0644, d_events
,
2296 tr
, &ftrace_tr_enable_fops
);
2298 tr
->event_dir
= d_events
;
2304 * event_trace_add_tracer - add a instance of a trace_array to events
2305 * @parent: The parent dentry to place the files/directories for events in
2306 * @tr: The trace array associated with these events
2308 * When a new instance is created, it needs to set up its events
2309 * directory, as well as other files associated with events. It also
2310 * creates the event hierachry in the @parent/events directory.
2312 * Returns 0 on success.
2314 int event_trace_add_tracer(struct dentry
*parent
, struct trace_array
*tr
)
2318 mutex_lock(&event_mutex
);
2320 ret
= create_event_toplevel_files(parent
, tr
);
2324 down_write(&trace_event_sem
);
2325 __trace_add_event_dirs(tr
);
2326 up_write(&trace_event_sem
);
2329 mutex_unlock(&event_mutex
);
2335 * The top trace array already had its file descriptors created.
2336 * Now the files themselves need to be created.
2339 early_event_add_tracer(struct dentry
*parent
, struct trace_array
*tr
)
2343 mutex_lock(&event_mutex
);
2345 ret
= create_event_toplevel_files(parent
, tr
);
2349 down_write(&trace_event_sem
);
2350 __trace_early_add_event_dirs(tr
);
2351 up_write(&trace_event_sem
);
2354 mutex_unlock(&event_mutex
);
2359 int event_trace_del_tracer(struct trace_array
*tr
)
2361 mutex_lock(&event_mutex
);
2363 /* Disable any event triggers and associated soft-disabled events */
2364 clear_event_triggers(tr
);
2366 /* Disable any running events */
2367 __ftrace_set_clr_event_nolock(tr
, NULL
, NULL
, NULL
, 0);
2369 /* Access to events are within rcu_read_lock_sched() */
2370 synchronize_sched();
2372 down_write(&trace_event_sem
);
2373 __trace_remove_event_dirs(tr
);
2374 debugfs_remove_recursive(tr
->event_dir
);
2375 up_write(&trace_event_sem
);
2377 tr
->event_dir
= NULL
;
2379 mutex_unlock(&event_mutex
);
2384 static __init
int event_trace_memsetup(void)
2386 field_cachep
= KMEM_CACHE(ftrace_event_field
, SLAB_PANIC
);
2387 file_cachep
= KMEM_CACHE(ftrace_event_file
, SLAB_PANIC
);
2391 static __init
int event_trace_enable(void)
2393 struct trace_array
*tr
= top_trace_array();
2394 struct ftrace_event_call
**iter
, *call
;
2395 char *buf
= bootup_event_buf
;
2399 for_each_event(iter
, __start_ftrace_events
, __stop_ftrace_events
) {
2402 ret
= event_init(call
);
2404 list_add(&call
->list
, &ftrace_events
);
2408 * We need the top trace array to have a working set of trace
2409 * points at early init, before the debug files and directories
2410 * are created. Create the file entries now, and attach them
2411 * to the actual file dentries later.
2413 __trace_early_add_events(tr
);
2416 token
= strsep(&buf
, ",");
2423 ret
= ftrace_set_clr_event(tr
, token
, 1);
2425 pr_warn("Failed to enable trace event: %s\n", token
);
2428 trace_printk_start_comm();
2430 register_event_cmds();
2432 register_trigger_cmds();
2437 static __init
int event_trace_init(void)
2439 struct trace_array
*tr
;
2440 struct dentry
*d_tracer
;
2441 struct dentry
*entry
;
2444 tr
= top_trace_array();
2446 d_tracer
= tracing_init_dentry();
2450 entry
= debugfs_create_file("available_events", 0444, d_tracer
,
2451 tr
, &ftrace_avail_fops
);
2453 pr_warning("Could not create debugfs "
2454 "'available_events' entry\n");
2456 if (trace_define_common_fields())
2457 pr_warning("tracing: Failed to allocate common fields");
2459 ret
= early_event_add_tracer(d_tracer
, tr
);
2463 #ifdef CONFIG_MODULES
2464 ret
= register_module_notifier(&trace_module_nb
);
2466 pr_warning("Failed to register trace events module notifier\n");
2470 early_initcall(event_trace_memsetup
);
2471 core_initcall(event_trace_enable
);
2472 fs_initcall(event_trace_init
);
2474 #ifdef CONFIG_FTRACE_STARTUP_TEST
2476 static DEFINE_SPINLOCK(test_spinlock
);
2477 static DEFINE_SPINLOCK(test_spinlock_irq
);
2478 static DEFINE_MUTEX(test_mutex
);
2480 static __init
void test_work(struct work_struct
*dummy
)
2482 spin_lock(&test_spinlock
);
2483 spin_lock_irq(&test_spinlock_irq
);
2485 spin_unlock_irq(&test_spinlock_irq
);
2486 spin_unlock(&test_spinlock
);
2488 mutex_lock(&test_mutex
);
2490 mutex_unlock(&test_mutex
);
2493 static __init
int event_test_thread(void *unused
)
2497 test_malloc
= kmalloc(1234, GFP_KERNEL
);
2499 pr_info("failed to kmalloc\n");
2501 schedule_on_each_cpu(test_work
);
2505 set_current_state(TASK_INTERRUPTIBLE
);
2506 while (!kthread_should_stop())
2513 * Do various things that may trigger events.
2515 static __init
void event_test_stuff(void)
2517 struct task_struct
*test_thread
;
2519 test_thread
= kthread_run(event_test_thread
, NULL
, "test-events");
2521 kthread_stop(test_thread
);
2525 * For every trace event defined, we will test each trace point separately,
2526 * and then by groups, and finally all trace points.
2528 static __init
void event_trace_self_tests(void)
2530 struct ftrace_subsystem_dir
*dir
;
2531 struct ftrace_event_file
*file
;
2532 struct ftrace_event_call
*call
;
2533 struct event_subsystem
*system
;
2534 struct trace_array
*tr
;
2537 tr
= top_trace_array();
2539 pr_info("Running tests on trace events:\n");
2541 list_for_each_entry(file
, &tr
->events
, list
) {
2543 call
= file
->event_call
;
2545 /* Only test those that have a probe */
2546 if (!call
->class || !call
->class->probe
)
2550 * Testing syscall events here is pretty useless, but
2551 * we still do it if configured. But this is time consuming.
2552 * What we really need is a user thread to perform the
2553 * syscalls as we test.
2555 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
2556 if (call
->class->system
&&
2557 strcmp(call
->class->system
, "syscalls") == 0)
2561 pr_info("Testing event %s: ", ftrace_event_name(call
));
2564 * If an event is already enabled, someone is using
2565 * it and the self test should not be on.
2567 if (file
->flags
& FTRACE_EVENT_FL_ENABLED
) {
2568 pr_warning("Enabled event during self test!\n");
2573 ftrace_event_enable_disable(file
, 1);
2575 ftrace_event_enable_disable(file
, 0);
2580 /* Now test at the sub system level */
2582 pr_info("Running tests on trace event systems:\n");
2584 list_for_each_entry(dir
, &tr
->systems
, list
) {
2586 system
= dir
->subsystem
;
2588 /* the ftrace system is special, skip it */
2589 if (strcmp(system
->name
, "ftrace") == 0)
2592 pr_info("Testing event system %s: ", system
->name
);
2594 ret
= __ftrace_set_clr_event(tr
, NULL
, system
->name
, NULL
, 1);
2595 if (WARN_ON_ONCE(ret
)) {
2596 pr_warning("error enabling system %s\n",
2603 ret
= __ftrace_set_clr_event(tr
, NULL
, system
->name
, NULL
, 0);
2604 if (WARN_ON_ONCE(ret
)) {
2605 pr_warning("error disabling system %s\n",
2613 /* Test with all events enabled */
2615 pr_info("Running tests on all trace events:\n");
2616 pr_info("Testing all events: ");
2618 ret
= __ftrace_set_clr_event(tr
, NULL
, NULL
, NULL
, 1);
2619 if (WARN_ON_ONCE(ret
)) {
2620 pr_warning("error enabling all events\n");
2627 ret
= __ftrace_set_clr_event(tr
, NULL
, NULL
, NULL
, 0);
2628 if (WARN_ON_ONCE(ret
)) {
2629 pr_warning("error disabling all events\n");
2636 #ifdef CONFIG_FUNCTION_TRACER
2638 static DEFINE_PER_CPU(atomic_t
, ftrace_test_event_disable
);
2641 function_test_events_call(unsigned long ip
, unsigned long parent_ip
,
2642 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
2644 struct ring_buffer_event
*event
;
2645 struct ring_buffer
*buffer
;
2646 struct ftrace_entry
*entry
;
2647 unsigned long flags
;
2652 pc
= preempt_count();
2653 preempt_disable_notrace();
2654 cpu
= raw_smp_processor_id();
2655 disabled
= atomic_inc_return(&per_cpu(ftrace_test_event_disable
, cpu
));
2660 local_save_flags(flags
);
2662 event
= trace_current_buffer_lock_reserve(&buffer
,
2663 TRACE_FN
, sizeof(*entry
),
2667 entry
= ring_buffer_event_data(event
);
2669 entry
->parent_ip
= parent_ip
;
2671 trace_buffer_unlock_commit(buffer
, event
, flags
, pc
);
2674 atomic_dec(&per_cpu(ftrace_test_event_disable
, cpu
));
2675 preempt_enable_notrace();
2678 static struct ftrace_ops trace_ops __initdata
=
2680 .func
= function_test_events_call
,
2681 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
,
2684 static __init
void event_trace_self_test_with_function(void)
2687 ret
= register_ftrace_function(&trace_ops
);
2688 if (WARN_ON(ret
< 0)) {
2689 pr_info("Failed to enable function tracer for event tests\n");
2692 pr_info("Running tests again, along with the function tracer\n");
2693 event_trace_self_tests();
2694 unregister_ftrace_function(&trace_ops
);
2697 static __init
void event_trace_self_test_with_function(void)
2702 static __init
int event_trace_self_tests_init(void)
2704 if (!tracing_selftest_disabled
) {
2705 event_trace_self_tests();
2706 event_trace_self_test_with_function();
2712 late_initcall(event_trace_self_tests_init
);