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 DEFINE_MUTEX(event_storage_mutex
);
31 EXPORT_SYMBOL_GPL(event_storage_mutex
);
33 char event_storage
[EVENT_STORAGE_SIZE
];
34 EXPORT_SYMBOL_GPL(event_storage
);
36 LIST_HEAD(ftrace_events
);
37 static LIST_HEAD(ftrace_common_fields
);
39 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
41 static struct kmem_cache
*field_cachep
;
42 static struct kmem_cache
*file_cachep
;
44 #define SYSTEM_FL_FREE_NAME (1 << 31)
46 static inline int system_refcount(struct event_subsystem
*system
)
48 return system
->ref_count
& ~SYSTEM_FL_FREE_NAME
;
51 static int system_refcount_inc(struct event_subsystem
*system
)
53 return (system
->ref_count
++) & ~SYSTEM_FL_FREE_NAME
;
56 static int system_refcount_dec(struct event_subsystem
*system
)
58 return (--system
->ref_count
) & ~SYSTEM_FL_FREE_NAME
;
61 /* Double loops, do not use break, only goto's work */
62 #define do_for_each_event_file(tr, file) \
63 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
64 list_for_each_entry(file, &tr->events, list)
66 #define do_for_each_event_file_safe(tr, file) \
67 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
68 struct ftrace_event_file *___n; \
69 list_for_each_entry_safe(file, ___n, &tr->events, list)
71 #define while_for_each_event_file() \
74 static struct list_head
*
75 trace_get_fields(struct ftrace_event_call
*event_call
)
77 if (!event_call
->class->get_fields
)
78 return &event_call
->class->fields
;
79 return event_call
->class->get_fields(event_call
);
82 static struct ftrace_event_field
*
83 __find_event_field(struct list_head
*head
, char *name
)
85 struct ftrace_event_field
*field
;
87 list_for_each_entry(field
, head
, link
) {
88 if (!strcmp(field
->name
, name
))
95 struct ftrace_event_field
*
96 trace_find_event_field(struct ftrace_event_call
*call
, char *name
)
98 struct ftrace_event_field
*field
;
99 struct list_head
*head
;
101 field
= __find_event_field(&ftrace_common_fields
, name
);
105 head
= trace_get_fields(call
);
106 return __find_event_field(head
, name
);
109 static int __trace_define_field(struct list_head
*head
, const char *type
,
110 const char *name
, int offset
, int size
,
111 int is_signed
, int filter_type
)
113 struct ftrace_event_field
*field
;
115 field
= kmem_cache_alloc(field_cachep
, GFP_TRACE
);
122 if (filter_type
== FILTER_OTHER
)
123 field
->filter_type
= filter_assign_type(type
);
125 field
->filter_type
= filter_type
;
127 field
->offset
= offset
;
129 field
->is_signed
= is_signed
;
131 list_add(&field
->link
, head
);
136 int trace_define_field(struct ftrace_event_call
*call
, const char *type
,
137 const char *name
, int offset
, int size
, int is_signed
,
140 struct list_head
*head
;
142 if (WARN_ON(!call
->class))
145 head
= trace_get_fields(call
);
146 return __trace_define_field(head
, type
, name
, offset
, size
,
147 is_signed
, filter_type
);
149 EXPORT_SYMBOL_GPL(trace_define_field
);
151 #define __common_field(type, item) \
152 ret = __trace_define_field(&ftrace_common_fields, #type, \
154 offsetof(typeof(ent), item), \
156 is_signed_type(type), FILTER_OTHER); \
160 static int trace_define_common_fields(void)
163 struct trace_entry ent
;
165 __common_field(unsigned short, type
);
166 __common_field(unsigned char, flags
);
167 __common_field(unsigned char, preempt_count
);
168 __common_field(int, pid
);
173 static void trace_destroy_fields(struct ftrace_event_call
*call
)
175 struct ftrace_event_field
*field
, *next
;
176 struct list_head
*head
;
178 head
= trace_get_fields(call
);
179 list_for_each_entry_safe(field
, next
, head
, link
) {
180 list_del(&field
->link
);
181 kmem_cache_free(field_cachep
, field
);
185 int trace_event_raw_init(struct ftrace_event_call
*call
)
189 id
= register_ftrace_event(&call
->event
);
195 EXPORT_SYMBOL_GPL(trace_event_raw_init
);
197 int ftrace_event_reg(struct ftrace_event_call
*call
,
198 enum trace_reg type
, void *data
)
200 struct ftrace_event_file
*file
= data
;
203 case TRACE_REG_REGISTER
:
204 return tracepoint_probe_register(call
->name
,
207 case TRACE_REG_UNREGISTER
:
208 tracepoint_probe_unregister(call
->name
,
213 #ifdef CONFIG_PERF_EVENTS
214 case TRACE_REG_PERF_REGISTER
:
215 return tracepoint_probe_register(call
->name
,
216 call
->class->perf_probe
,
218 case TRACE_REG_PERF_UNREGISTER
:
219 tracepoint_probe_unregister(call
->name
,
220 call
->class->perf_probe
,
223 case TRACE_REG_PERF_OPEN
:
224 case TRACE_REG_PERF_CLOSE
:
225 case TRACE_REG_PERF_ADD
:
226 case TRACE_REG_PERF_DEL
:
232 EXPORT_SYMBOL_GPL(ftrace_event_reg
);
234 void trace_event_enable_cmd_record(bool enable
)
236 struct ftrace_event_file
*file
;
237 struct trace_array
*tr
;
239 mutex_lock(&event_mutex
);
240 do_for_each_event_file(tr
, file
) {
242 if (!(file
->flags
& FTRACE_EVENT_FL_ENABLED
))
246 tracing_start_cmdline_record();
247 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT
, &file
->flags
);
249 tracing_stop_cmdline_record();
250 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT
, &file
->flags
);
252 } while_for_each_event_file();
253 mutex_unlock(&event_mutex
);
256 static int __ftrace_event_enable_disable(struct ftrace_event_file
*file
,
257 int enable
, int soft_disable
)
259 struct ftrace_event_call
*call
= file
->event_call
;
266 * When soft_disable is set and enable is cleared, the sm_ref
267 * reference counter is decremented. If it reaches 0, we want
268 * to clear the SOFT_DISABLED flag but leave the event in the
269 * state that it was. That is, if the event was enabled and
270 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
271 * is set we do not want the event to be enabled before we
274 * When soft_disable is not set but the SOFT_MODE flag is,
275 * we do nothing. Do not disable the tracepoint, otherwise
276 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
279 if (atomic_dec_return(&file
->sm_ref
) > 0)
281 disable
= file
->flags
& FTRACE_EVENT_FL_SOFT_DISABLED
;
282 clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT
, &file
->flags
);
284 disable
= !(file
->flags
& FTRACE_EVENT_FL_SOFT_MODE
);
286 if (disable
&& (file
->flags
& FTRACE_EVENT_FL_ENABLED
)) {
287 clear_bit(FTRACE_EVENT_FL_ENABLED_BIT
, &file
->flags
);
288 if (file
->flags
& FTRACE_EVENT_FL_RECORDED_CMD
) {
289 tracing_stop_cmdline_record();
290 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT
, &file
->flags
);
292 call
->class->reg(call
, TRACE_REG_UNREGISTER
, file
);
294 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
295 if (file
->flags
& FTRACE_EVENT_FL_SOFT_MODE
)
296 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT
, &file
->flags
);
298 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT
, &file
->flags
);
302 * When soft_disable is set and enable is set, we want to
303 * register the tracepoint for the event, but leave the event
304 * as is. That means, if the event was already enabled, we do
305 * nothing (but set SOFT_MODE). If the event is disabled, we
306 * set SOFT_DISABLED before enabling the event tracepoint, so
307 * it still seems to be disabled.
310 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT
, &file
->flags
);
312 if (atomic_inc_return(&file
->sm_ref
) > 1)
314 set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT
, &file
->flags
);
317 if (!(file
->flags
& FTRACE_EVENT_FL_ENABLED
)) {
319 /* Keep the event disabled, when going to SOFT_MODE. */
321 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT
, &file
->flags
);
323 if (trace_flags
& TRACE_ITER_RECORD_CMD
) {
324 tracing_start_cmdline_record();
325 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT
, &file
->flags
);
327 ret
= call
->class->reg(call
, TRACE_REG_REGISTER
, file
);
329 tracing_stop_cmdline_record();
330 pr_info("event trace: Could not enable event "
334 set_bit(FTRACE_EVENT_FL_ENABLED_BIT
, &file
->flags
);
336 /* WAS_ENABLED gets set but never cleared. */
337 call
->flags
|= TRACE_EVENT_FL_WAS_ENABLED
;
345 static int ftrace_event_enable_disable(struct ftrace_event_file
*file
,
348 return __ftrace_event_enable_disable(file
, enable
, 0);
351 static void ftrace_clear_events(struct trace_array
*tr
)
353 struct ftrace_event_file
*file
;
355 mutex_lock(&event_mutex
);
356 list_for_each_entry(file
, &tr
->events
, list
) {
357 ftrace_event_enable_disable(file
, 0);
359 mutex_unlock(&event_mutex
);
362 static void __put_system(struct event_subsystem
*system
)
364 struct event_filter
*filter
= system
->filter
;
366 WARN_ON_ONCE(system_refcount(system
) == 0);
367 if (system_refcount_dec(system
))
370 list_del(&system
->list
);
373 kfree(filter
->filter_string
);
376 if (system
->ref_count
& SYSTEM_FL_FREE_NAME
)
381 static void __get_system(struct event_subsystem
*system
)
383 WARN_ON_ONCE(system_refcount(system
) == 0);
384 system_refcount_inc(system
);
387 static void __get_system_dir(struct ftrace_subsystem_dir
*dir
)
389 WARN_ON_ONCE(dir
->ref_count
== 0);
391 __get_system(dir
->subsystem
);
394 static void __put_system_dir(struct ftrace_subsystem_dir
*dir
)
396 WARN_ON_ONCE(dir
->ref_count
== 0);
397 /* If the subsystem is about to be freed, the dir must be too */
398 WARN_ON_ONCE(system_refcount(dir
->subsystem
) == 1 && dir
->ref_count
!= 1);
400 __put_system(dir
->subsystem
);
401 if (!--dir
->ref_count
)
405 static void put_system(struct ftrace_subsystem_dir
*dir
)
407 mutex_lock(&event_mutex
);
408 __put_system_dir(dir
);
409 mutex_unlock(&event_mutex
);
412 static void *event_file_data(struct file
*filp
)
414 return ACCESS_ONCE(file_inode(filp
)->i_private
);
418 * Open and update trace_array ref count.
419 * Must have the current trace_array passed to it.
421 static int tracing_open_generic_file(struct inode
*inode
, struct file
*filp
)
423 struct ftrace_event_file
*file
= inode
->i_private
;
424 struct trace_array
*tr
= file
->tr
;
427 if (trace_array_get(tr
) < 0)
430 ret
= tracing_open_generic(inode
, filp
);
436 static int tracing_release_generic_file(struct inode
*inode
, struct file
*filp
)
438 struct ftrace_event_file
*file
= inode
->i_private
;
439 struct trace_array
*tr
= file
->tr
;
447 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
450 __ftrace_set_clr_event_nolock(struct trace_array
*tr
, const char *match
,
451 const char *sub
, const char *event
, int set
)
453 struct ftrace_event_file
*file
;
454 struct ftrace_event_call
*call
;
457 list_for_each_entry(file
, &tr
->events
, list
) {
459 call
= file
->event_call
;
461 if (!call
->name
|| !call
->class || !call
->class->reg
)
464 if (call
->flags
& TRACE_EVENT_FL_IGNORE_ENABLE
)
468 strcmp(match
, call
->name
) != 0 &&
469 strcmp(match
, call
->class->system
) != 0)
472 if (sub
&& strcmp(sub
, call
->class->system
) != 0)
475 if (event
&& strcmp(event
, call
->name
) != 0)
478 ftrace_event_enable_disable(file
, set
);
486 static int __ftrace_set_clr_event(struct trace_array
*tr
, const char *match
,
487 const char *sub
, const char *event
, int set
)
491 mutex_lock(&event_mutex
);
492 ret
= __ftrace_set_clr_event_nolock(tr
, match
, sub
, event
, set
);
493 mutex_unlock(&event_mutex
);
498 static int ftrace_set_clr_event(struct trace_array
*tr
, char *buf
, int set
)
500 char *event
= NULL
, *sub
= NULL
, *match
;
503 * The buf format can be <subsystem>:<event-name>
504 * *:<event-name> means any event by that name.
505 * :<event-name> is the same.
507 * <subsystem>:* means all events in that subsystem
508 * <subsystem>: means the same.
510 * <name> (no ':') means all events in a subsystem with
511 * the name <name> or any event that matches <name>
514 match
= strsep(&buf
, ":");
520 if (!strlen(sub
) || strcmp(sub
, "*") == 0)
522 if (!strlen(event
) || strcmp(event
, "*") == 0)
526 return __ftrace_set_clr_event(tr
, match
, sub
, event
, set
);
530 * trace_set_clr_event - enable or disable an event
531 * @system: system name to match (NULL for any system)
532 * @event: event name to match (NULL for all events, within system)
533 * @set: 1 to enable, 0 to disable
535 * This is a way for other parts of the kernel to enable or disable
538 * Returns 0 on success, -EINVAL if the parameters do not match any
541 int trace_set_clr_event(const char *system
, const char *event
, int set
)
543 struct trace_array
*tr
= top_trace_array();
545 return __ftrace_set_clr_event(tr
, NULL
, system
, event
, set
);
547 EXPORT_SYMBOL_GPL(trace_set_clr_event
);
549 /* 128 should be much more than enough */
550 #define EVENT_BUF_SIZE 127
553 ftrace_event_write(struct file
*file
, const char __user
*ubuf
,
554 size_t cnt
, loff_t
*ppos
)
556 struct trace_parser parser
;
557 struct seq_file
*m
= file
->private_data
;
558 struct trace_array
*tr
= m
->private;
564 ret
= tracing_update_buffers();
568 if (trace_parser_get_init(&parser
, EVENT_BUF_SIZE
+ 1))
571 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
573 if (read
>= 0 && trace_parser_loaded((&parser
))) {
576 if (*parser
.buffer
== '!')
579 parser
.buffer
[parser
.idx
] = 0;
581 ret
= ftrace_set_clr_event(tr
, parser
.buffer
+ !set
, set
);
589 trace_parser_put(&parser
);
595 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
597 struct ftrace_event_file
*file
= v
;
598 struct ftrace_event_call
*call
;
599 struct trace_array
*tr
= m
->private;
603 list_for_each_entry_continue(file
, &tr
->events
, list
) {
604 call
= file
->event_call
;
606 * The ftrace subsystem is for showing formats only.
607 * They can not be enabled or disabled via the event files.
609 if (call
->class && call
->class->reg
)
616 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
618 struct ftrace_event_file
*file
;
619 struct trace_array
*tr
= m
->private;
622 mutex_lock(&event_mutex
);
624 file
= list_entry(&tr
->events
, struct ftrace_event_file
, list
);
625 for (l
= 0; l
<= *pos
; ) {
626 file
= t_next(m
, file
, &l
);
634 s_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
636 struct ftrace_event_file
*file
= v
;
637 struct trace_array
*tr
= m
->private;
641 list_for_each_entry_continue(file
, &tr
->events
, list
) {
642 if (file
->flags
& FTRACE_EVENT_FL_ENABLED
)
649 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
651 struct ftrace_event_file
*file
;
652 struct trace_array
*tr
= m
->private;
655 mutex_lock(&event_mutex
);
657 file
= list_entry(&tr
->events
, struct ftrace_event_file
, list
);
658 for (l
= 0; l
<= *pos
; ) {
659 file
= s_next(m
, file
, &l
);
666 static int t_show(struct seq_file
*m
, void *v
)
668 struct ftrace_event_file
*file
= v
;
669 struct ftrace_event_call
*call
= file
->event_call
;
671 if (strcmp(call
->class->system
, TRACE_SYSTEM
) != 0)
672 seq_printf(m
, "%s:", call
->class->system
);
673 seq_printf(m
, "%s\n", call
->name
);
678 static void t_stop(struct seq_file
*m
, void *p
)
680 mutex_unlock(&event_mutex
);
684 event_enable_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
687 struct ftrace_event_file
*file
;
691 mutex_lock(&event_mutex
);
692 file
= event_file_data(filp
);
695 mutex_unlock(&event_mutex
);
700 if (flags
& FTRACE_EVENT_FL_ENABLED
&&
701 !(flags
& FTRACE_EVENT_FL_SOFT_DISABLED
))
704 if (flags
& FTRACE_EVENT_FL_SOFT_DISABLED
||
705 flags
& FTRACE_EVENT_FL_SOFT_MODE
)
710 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, strlen(buf
));
714 event_enable_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
717 struct ftrace_event_file
*file
;
721 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
725 ret
= tracing_update_buffers();
733 mutex_lock(&event_mutex
);
734 file
= event_file_data(filp
);
736 ret
= ftrace_event_enable_disable(file
, val
);
737 mutex_unlock(&event_mutex
);
746 return ret
? ret
: cnt
;
750 system_enable_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
753 const char set_to_char
[4] = { '?', '0', '1', 'X' };
754 struct ftrace_subsystem_dir
*dir
= filp
->private_data
;
755 struct event_subsystem
*system
= dir
->subsystem
;
756 struct ftrace_event_call
*call
;
757 struct ftrace_event_file
*file
;
758 struct trace_array
*tr
= dir
->tr
;
763 mutex_lock(&event_mutex
);
764 list_for_each_entry(file
, &tr
->events
, list
) {
765 call
= file
->event_call
;
766 if (!call
->name
|| !call
->class || !call
->class->reg
)
769 if (system
&& strcmp(call
->class->system
, system
->name
) != 0)
773 * We need to find out if all the events are set
774 * or if all events or cleared, or if we have
777 set
|= (1 << !!(file
->flags
& FTRACE_EVENT_FL_ENABLED
));
780 * If we have a mixture, no need to look further.
785 mutex_unlock(&event_mutex
);
787 buf
[0] = set_to_char
[set
];
790 ret
= simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, 2);
796 system_enable_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
799 struct ftrace_subsystem_dir
*dir
= filp
->private_data
;
800 struct event_subsystem
*system
= dir
->subsystem
;
801 const char *name
= NULL
;
805 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
809 ret
= tracing_update_buffers();
813 if (val
!= 0 && val
!= 1)
817 * Opening of "enable" adds a ref count to system,
818 * so the name is safe to use.
823 ret
= __ftrace_set_clr_event(dir
->tr
, NULL
, name
, NULL
, val
);
837 FORMAT_FIELD_SEPERATOR
= 2,
841 static void *f_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
843 struct ftrace_event_call
*call
= event_file_data(m
->private);
844 struct list_head
*common_head
= &ftrace_common_fields
;
845 struct list_head
*head
= trace_get_fields(call
);
846 struct list_head
*node
= v
;
850 switch ((unsigned long)v
) {
855 case FORMAT_FIELD_SEPERATOR
:
859 case FORMAT_PRINTFMT
:
865 if (node
== common_head
)
866 return (void *)FORMAT_FIELD_SEPERATOR
;
867 else if (node
== head
)
868 return (void *)FORMAT_PRINTFMT
;
873 static int f_show(struct seq_file
*m
, void *v
)
875 struct ftrace_event_call
*call
= event_file_data(m
->private);
876 struct ftrace_event_field
*field
;
877 const char *array_descriptor
;
879 switch ((unsigned long)v
) {
881 seq_printf(m
, "name: %s\n", call
->name
);
882 seq_printf(m
, "ID: %d\n", call
->event
.type
);
883 seq_printf(m
, "format:\n");
886 case FORMAT_FIELD_SEPERATOR
:
890 case FORMAT_PRINTFMT
:
891 seq_printf(m
, "\nprint fmt: %s\n",
896 field
= list_entry(v
, struct ftrace_event_field
, link
);
898 * Smartly shows the array type(except dynamic array).
901 * If TYPE := TYPE[LEN], it is shown:
902 * field:TYPE VAR[LEN]
904 array_descriptor
= strchr(field
->type
, '[');
906 if (!strncmp(field
->type
, "__data_loc", 10))
907 array_descriptor
= NULL
;
909 if (!array_descriptor
)
910 seq_printf(m
, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
911 field
->type
, field
->name
, field
->offset
,
912 field
->size
, !!field
->is_signed
);
914 seq_printf(m
, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
915 (int)(array_descriptor
- field
->type
),
916 field
->type
, field
->name
,
917 array_descriptor
, field
->offset
,
918 field
->size
, !!field
->is_signed
);
923 static void *f_start(struct seq_file
*m
, loff_t
*pos
)
925 void *p
= (void *)FORMAT_HEADER
;
928 /* ->stop() is called even if ->start() fails */
929 mutex_lock(&event_mutex
);
930 if (!event_file_data(m
->private))
931 return ERR_PTR(-ENODEV
);
933 while (l
< *pos
&& p
)
934 p
= f_next(m
, p
, &l
);
939 static void f_stop(struct seq_file
*m
, void *p
)
941 mutex_unlock(&event_mutex
);
944 static const struct seq_operations trace_format_seq_ops
= {
951 static int trace_format_open(struct inode
*inode
, struct file
*file
)
956 ret
= seq_open(file
, &trace_format_seq_ops
);
960 m
= file
->private_data
;
967 event_id_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
, loff_t
*ppos
)
969 int id
= (long)event_file_data(filp
);
979 len
= sprintf(buf
, "%d\n", id
);
981 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, len
);
985 event_filter_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
988 struct ftrace_event_call
*call
;
995 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
1002 mutex_lock(&event_mutex
);
1003 call
= event_file_data(filp
);
1005 print_event_filter(call
, s
);
1006 mutex_unlock(&event_mutex
);
1009 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, s
->buffer
, s
->len
);
1017 event_filter_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
1020 struct ftrace_event_call
*call
;
1024 if (cnt
>= PAGE_SIZE
)
1027 buf
= (char *)__get_free_page(GFP_TEMPORARY
);
1031 if (copy_from_user(buf
, ubuf
, cnt
)) {
1032 free_page((unsigned long) buf
);
1037 mutex_lock(&event_mutex
);
1038 call
= event_file_data(filp
);
1040 err
= apply_event_filter(call
, buf
);
1041 mutex_unlock(&event_mutex
);
1043 free_page((unsigned long) buf
);
1052 static LIST_HEAD(event_subsystems
);
1054 static int subsystem_open(struct inode
*inode
, struct file
*filp
)
1056 struct event_subsystem
*system
= NULL
;
1057 struct ftrace_subsystem_dir
*dir
= NULL
; /* Initialize for gcc */
1058 struct trace_array
*tr
;
1061 /* Make sure the system still exists */
1062 mutex_lock(&trace_types_lock
);
1063 mutex_lock(&event_mutex
);
1064 list_for_each_entry(tr
, &ftrace_trace_arrays
, list
) {
1065 list_for_each_entry(dir
, &tr
->systems
, list
) {
1066 if (dir
== inode
->i_private
) {
1067 /* Don't open systems with no events */
1068 if (dir
->nr_events
) {
1069 __get_system_dir(dir
);
1070 system
= dir
->subsystem
;
1077 mutex_unlock(&event_mutex
);
1078 mutex_unlock(&trace_types_lock
);
1083 /* Some versions of gcc think dir can be uninitialized here */
1086 /* Still need to increment the ref count of the system */
1087 if (trace_array_get(tr
) < 0) {
1092 ret
= tracing_open_generic(inode
, filp
);
1094 trace_array_put(tr
);
1101 static int system_tr_open(struct inode
*inode
, struct file
*filp
)
1103 struct ftrace_subsystem_dir
*dir
;
1104 struct trace_array
*tr
= inode
->i_private
;
1107 if (trace_array_get(tr
) < 0)
1110 /* Make a temporary dir that has no system but points to tr */
1111 dir
= kzalloc(sizeof(*dir
), GFP_KERNEL
);
1113 trace_array_put(tr
);
1119 ret
= tracing_open_generic(inode
, filp
);
1121 trace_array_put(tr
);
1125 filp
->private_data
= dir
;
1130 static int subsystem_release(struct inode
*inode
, struct file
*file
)
1132 struct ftrace_subsystem_dir
*dir
= file
->private_data
;
1134 trace_array_put(dir
->tr
);
1137 * If dir->subsystem is NULL, then this is a temporary
1138 * descriptor that was made for a trace_array to enable
1150 subsystem_filter_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
1153 struct ftrace_subsystem_dir
*dir
= filp
->private_data
;
1154 struct event_subsystem
*system
= dir
->subsystem
;
1155 struct trace_seq
*s
;
1161 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
1167 print_subsystem_event_filter(system
, s
);
1168 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, s
->buffer
, s
->len
);
1176 subsystem_filter_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
1179 struct ftrace_subsystem_dir
*dir
= filp
->private_data
;
1183 if (cnt
>= PAGE_SIZE
)
1186 buf
= (char *)__get_free_page(GFP_TEMPORARY
);
1190 if (copy_from_user(buf
, ubuf
, cnt
)) {
1191 free_page((unsigned long) buf
);
1196 err
= apply_subsystem_event_filter(dir
, buf
);
1197 free_page((unsigned long) buf
);
1207 show_header(struct file
*filp
, char __user
*ubuf
, size_t cnt
, loff_t
*ppos
)
1209 int (*func
)(struct trace_seq
*s
) = filp
->private_data
;
1210 struct trace_seq
*s
;
1216 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
1223 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, s
->buffer
, s
->len
);
1230 static int ftrace_event_avail_open(struct inode
*inode
, struct file
*file
);
1231 static int ftrace_event_set_open(struct inode
*inode
, struct file
*file
);
1232 static int ftrace_event_release(struct inode
*inode
, struct file
*file
);
1234 static const struct seq_operations show_event_seq_ops
= {
1241 static const struct seq_operations show_set_event_seq_ops
= {
1248 static const struct file_operations ftrace_avail_fops
= {
1249 .open
= ftrace_event_avail_open
,
1251 .llseek
= seq_lseek
,
1252 .release
= seq_release
,
1255 static const struct file_operations ftrace_set_event_fops
= {
1256 .open
= ftrace_event_set_open
,
1258 .write
= ftrace_event_write
,
1259 .llseek
= seq_lseek
,
1260 .release
= ftrace_event_release
,
1263 static const struct file_operations ftrace_enable_fops
= {
1264 .open
= tracing_open_generic_file
,
1265 .read
= event_enable_read
,
1266 .write
= event_enable_write
,
1267 .release
= tracing_release_generic_file
,
1268 .llseek
= default_llseek
,
1271 static const struct file_operations ftrace_event_format_fops
= {
1272 .open
= trace_format_open
,
1274 .llseek
= seq_lseek
,
1275 .release
= seq_release
,
1278 static const struct file_operations ftrace_event_id_fops
= {
1279 .read
= event_id_read
,
1280 .llseek
= default_llseek
,
1283 static const struct file_operations ftrace_event_filter_fops
= {
1284 .open
= tracing_open_generic
,
1285 .read
= event_filter_read
,
1286 .write
= event_filter_write
,
1287 .llseek
= default_llseek
,
1290 static const struct file_operations ftrace_subsystem_filter_fops
= {
1291 .open
= subsystem_open
,
1292 .read
= subsystem_filter_read
,
1293 .write
= subsystem_filter_write
,
1294 .llseek
= default_llseek
,
1295 .release
= subsystem_release
,
1298 static const struct file_operations ftrace_system_enable_fops
= {
1299 .open
= subsystem_open
,
1300 .read
= system_enable_read
,
1301 .write
= system_enable_write
,
1302 .llseek
= default_llseek
,
1303 .release
= subsystem_release
,
1306 static const struct file_operations ftrace_tr_enable_fops
= {
1307 .open
= system_tr_open
,
1308 .read
= system_enable_read
,
1309 .write
= system_enable_write
,
1310 .llseek
= default_llseek
,
1311 .release
= subsystem_release
,
1314 static const struct file_operations ftrace_show_header_fops
= {
1315 .open
= tracing_open_generic
,
1316 .read
= show_header
,
1317 .llseek
= default_llseek
,
1321 ftrace_event_open(struct inode
*inode
, struct file
*file
,
1322 const struct seq_operations
*seq_ops
)
1327 ret
= seq_open(file
, seq_ops
);
1330 m
= file
->private_data
;
1331 /* copy tr over to seq ops */
1332 m
->private = inode
->i_private
;
1337 static int ftrace_event_release(struct inode
*inode
, struct file
*file
)
1339 struct trace_array
*tr
= inode
->i_private
;
1341 trace_array_put(tr
);
1343 return seq_release(inode
, file
);
1347 ftrace_event_avail_open(struct inode
*inode
, struct file
*file
)
1349 const struct seq_operations
*seq_ops
= &show_event_seq_ops
;
1351 return ftrace_event_open(inode
, file
, seq_ops
);
1355 ftrace_event_set_open(struct inode
*inode
, struct file
*file
)
1357 const struct seq_operations
*seq_ops
= &show_set_event_seq_ops
;
1358 struct trace_array
*tr
= inode
->i_private
;
1361 if (trace_array_get(tr
) < 0)
1364 if ((file
->f_mode
& FMODE_WRITE
) &&
1365 (file
->f_flags
& O_TRUNC
))
1366 ftrace_clear_events(tr
);
1368 ret
= ftrace_event_open(inode
, file
, seq_ops
);
1370 trace_array_put(tr
);
1374 static struct event_subsystem
*
1375 create_new_subsystem(const char *name
)
1377 struct event_subsystem
*system
;
1379 /* need to create new entry */
1380 system
= kmalloc(sizeof(*system
), GFP_KERNEL
);
1384 system
->ref_count
= 1;
1386 /* Only allocate if dynamic (kprobes and modules) */
1387 if (!core_kernel_data((unsigned long)name
)) {
1388 system
->ref_count
|= SYSTEM_FL_FREE_NAME
;
1389 system
->name
= kstrdup(name
, GFP_KERNEL
);
1393 system
->name
= name
;
1395 system
->filter
= NULL
;
1397 system
->filter
= kzalloc(sizeof(struct event_filter
), GFP_KERNEL
);
1398 if (!system
->filter
)
1401 list_add(&system
->list
, &event_subsystems
);
1406 if (system
->ref_count
& SYSTEM_FL_FREE_NAME
)
1407 kfree(system
->name
);
1412 static struct dentry
*
1413 event_subsystem_dir(struct trace_array
*tr
, const char *name
,
1414 struct ftrace_event_file
*file
, struct dentry
*parent
)
1416 struct ftrace_subsystem_dir
*dir
;
1417 struct event_subsystem
*system
;
1418 struct dentry
*entry
;
1420 /* First see if we did not already create this dir */
1421 list_for_each_entry(dir
, &tr
->systems
, list
) {
1422 system
= dir
->subsystem
;
1423 if (strcmp(system
->name
, name
) == 0) {
1430 /* Now see if the system itself exists. */
1431 list_for_each_entry(system
, &event_subsystems
, list
) {
1432 if (strcmp(system
->name
, name
) == 0)
1435 /* Reset system variable when not found */
1436 if (&system
->list
== &event_subsystems
)
1439 dir
= kmalloc(sizeof(*dir
), GFP_KERNEL
);
1444 system
= create_new_subsystem(name
);
1448 __get_system(system
);
1450 dir
->entry
= debugfs_create_dir(name
, parent
);
1452 pr_warning("Failed to create system directory %s\n", name
);
1453 __put_system(system
);
1460 dir
->subsystem
= system
;
1463 entry
= debugfs_create_file("filter", 0644, dir
->entry
, dir
,
1464 &ftrace_subsystem_filter_fops
);
1466 kfree(system
->filter
);
1467 system
->filter
= NULL
;
1468 pr_warning("Could not create debugfs '%s/filter' entry\n", name
);
1471 trace_create_file("enable", 0644, dir
->entry
, dir
,
1472 &ftrace_system_enable_fops
);
1474 list_add(&dir
->list
, &tr
->systems
);
1481 /* Only print this message if failed on memory allocation */
1482 if (!dir
|| !system
)
1483 pr_warning("No memory to create event subsystem %s\n",
1489 event_create_dir(struct dentry
*parent
,
1490 struct ftrace_event_file
*file
,
1491 const struct file_operations
*id
,
1492 const struct file_operations
*enable
,
1493 const struct file_operations
*filter
,
1494 const struct file_operations
*format
)
1496 struct ftrace_event_call
*call
= file
->event_call
;
1497 struct trace_array
*tr
= file
->tr
;
1498 struct list_head
*head
;
1499 struct dentry
*d_events
;
1503 * If the trace point header did not define TRACE_SYSTEM
1504 * then the system would be called "TRACE_SYSTEM".
1506 if (strcmp(call
->class->system
, TRACE_SYSTEM
) != 0) {
1507 d_events
= event_subsystem_dir(tr
, call
->class->system
, file
, parent
);
1513 file
->dir
= debugfs_create_dir(call
->name
, d_events
);
1515 pr_warning("Could not create debugfs '%s' directory\n",
1520 if (call
->class->reg
&& !(call
->flags
& TRACE_EVENT_FL_IGNORE_ENABLE
))
1521 trace_create_file("enable", 0644, file
->dir
, file
,
1524 #ifdef CONFIG_PERF_EVENTS
1525 if (call
->event
.type
&& call
->class->reg
)
1526 trace_create_file("id", 0444, file
->dir
,
1527 (void *)(long)call
->event
.type
, id
);
1531 * Other events may have the same class. Only update
1532 * the fields if they are not already defined.
1534 head
= trace_get_fields(call
);
1535 if (list_empty(head
)) {
1536 ret
= call
->class->define_fields(call
);
1538 pr_warning("Could not initialize trace point"
1539 " events/%s\n", call
->name
);
1543 trace_create_file("filter", 0644, file
->dir
, call
,
1546 trace_create_file("format", 0444, file
->dir
, call
,
1552 static void remove_subsystem(struct ftrace_subsystem_dir
*dir
)
1557 if (!--dir
->nr_events
) {
1558 debugfs_remove_recursive(dir
->entry
);
1559 list_del(&dir
->list
);
1560 __put_system_dir(dir
);
1564 static void remove_event_from_tracers(struct ftrace_event_call
*call
)
1566 struct ftrace_event_file
*file
;
1567 struct trace_array
*tr
;
1569 do_for_each_event_file_safe(tr
, file
) {
1571 if (file
->event_call
!= call
)
1574 list_del(&file
->list
);
1575 debugfs_remove_recursive(file
->dir
);
1576 remove_subsystem(file
->system
);
1577 kmem_cache_free(file_cachep
, file
);
1580 * The do_for_each_event_file_safe() is
1581 * a double loop. After finding the call for this
1582 * trace_array, we use break to jump to the next
1586 } while_for_each_event_file();
1589 static void event_remove(struct ftrace_event_call
*call
)
1591 struct trace_array
*tr
;
1592 struct ftrace_event_file
*file
;
1594 do_for_each_event_file(tr
, file
) {
1595 if (file
->event_call
!= call
)
1597 ftrace_event_enable_disable(file
, 0);
1599 * The do_for_each_event_file() is
1600 * a double loop. After finding the call for this
1601 * trace_array, we use break to jump to the next
1605 } while_for_each_event_file();
1607 if (call
->event
.funcs
)
1608 __unregister_ftrace_event(&call
->event
);
1609 remove_event_from_tracers(call
);
1610 list_del(&call
->list
);
1613 static int event_init(struct ftrace_event_call
*call
)
1617 if (WARN_ON(!call
->name
))
1620 if (call
->class->raw_init
) {
1621 ret
= call
->class->raw_init(call
);
1622 if (ret
< 0 && ret
!= -ENOSYS
)
1623 pr_warn("Could not initialize trace events/%s\n",
1631 __register_event(struct ftrace_event_call
*call
, struct module
*mod
)
1635 ret
= event_init(call
);
1639 list_add(&call
->list
, &ftrace_events
);
1645 static struct ftrace_event_file
*
1646 trace_create_new_event(struct ftrace_event_call
*call
,
1647 struct trace_array
*tr
)
1649 struct ftrace_event_file
*file
;
1651 file
= kmem_cache_alloc(file_cachep
, GFP_TRACE
);
1655 file
->event_call
= call
;
1657 atomic_set(&file
->sm_ref
, 0);
1658 list_add(&file
->list
, &tr
->events
);
1663 /* Add an event to a trace directory */
1665 __trace_add_new_event(struct ftrace_event_call
*call
,
1666 struct trace_array
*tr
,
1667 const struct file_operations
*id
,
1668 const struct file_operations
*enable
,
1669 const struct file_operations
*filter
,
1670 const struct file_operations
*format
)
1672 struct ftrace_event_file
*file
;
1674 file
= trace_create_new_event(call
, tr
);
1678 return event_create_dir(tr
->event_dir
, file
, id
, enable
, filter
, format
);
1682 * Just create a decriptor for early init. A descriptor is required
1683 * for enabling events at boot. We want to enable events before
1684 * the filesystem is initialized.
1687 __trace_early_add_new_event(struct ftrace_event_call
*call
,
1688 struct trace_array
*tr
)
1690 struct ftrace_event_file
*file
;
1692 file
= trace_create_new_event(call
, tr
);
1699 struct ftrace_module_file_ops
;
1700 static void __add_event_to_tracers(struct ftrace_event_call
*call
,
1701 struct ftrace_module_file_ops
*file_ops
);
1703 /* Add an additional event_call dynamically */
1704 int trace_add_event_call(struct ftrace_event_call
*call
)
1707 mutex_lock(&trace_types_lock
);
1708 mutex_lock(&event_mutex
);
1710 ret
= __register_event(call
, NULL
);
1712 __add_event_to_tracers(call
, NULL
);
1714 mutex_unlock(&event_mutex
);
1715 mutex_unlock(&trace_types_lock
);
1720 * Must be called under locking of trace_types_lock, event_mutex and
1723 static void __trace_remove_event_call(struct ftrace_event_call
*call
)
1726 trace_destroy_fields(call
);
1727 destroy_preds(call
);
1730 /* Remove an event_call */
1731 void trace_remove_event_call(struct ftrace_event_call
*call
)
1733 mutex_lock(&trace_types_lock
);
1734 mutex_lock(&event_mutex
);
1735 down_write(&trace_event_sem
);
1736 __trace_remove_event_call(call
);
1737 up_write(&trace_event_sem
);
1738 mutex_unlock(&event_mutex
);
1739 mutex_unlock(&trace_types_lock
);
1742 #define for_each_event(event, start, end) \
1743 for (event = start; \
1744 (unsigned long)event < (unsigned long)end; \
1747 #ifdef CONFIG_MODULES
1749 static LIST_HEAD(ftrace_module_file_list
);
1752 * Modules must own their file_operations to keep up with
1753 * reference counting.
1755 struct ftrace_module_file_ops
{
1756 struct list_head list
;
1758 struct file_operations id
;
1759 struct file_operations enable
;
1760 struct file_operations format
;
1761 struct file_operations filter
;
1764 static struct ftrace_module_file_ops
*
1765 find_ftrace_file_ops(struct ftrace_module_file_ops
*file_ops
, struct module
*mod
)
1768 * As event_calls are added in groups by module,
1769 * when we find one file_ops, we don't need to search for
1770 * each call in that module, as the rest should be the
1771 * same. Only search for a new one if the last one did
1774 if (file_ops
&& mod
== file_ops
->mod
)
1777 list_for_each_entry(file_ops
, &ftrace_module_file_list
, list
) {
1778 if (file_ops
->mod
== mod
)
1784 static struct ftrace_module_file_ops
*
1785 trace_create_file_ops(struct module
*mod
)
1787 struct ftrace_module_file_ops
*file_ops
;
1790 * This is a bit of a PITA. To allow for correct reference
1791 * counting, modules must "own" their file_operations.
1792 * To do this, we allocate the file operations that will be
1793 * used in the event directory.
1796 file_ops
= kmalloc(sizeof(*file_ops
), GFP_KERNEL
);
1800 file_ops
->mod
= mod
;
1802 file_ops
->id
= ftrace_event_id_fops
;
1803 file_ops
->id
.owner
= mod
;
1805 file_ops
->enable
= ftrace_enable_fops
;
1806 file_ops
->enable
.owner
= mod
;
1808 file_ops
->filter
= ftrace_event_filter_fops
;
1809 file_ops
->filter
.owner
= mod
;
1811 file_ops
->format
= ftrace_event_format_fops
;
1812 file_ops
->format
.owner
= mod
;
1814 list_add(&file_ops
->list
, &ftrace_module_file_list
);
1819 static void trace_module_add_events(struct module
*mod
)
1821 struct ftrace_module_file_ops
*file_ops
= NULL
;
1822 struct ftrace_event_call
**call
, **start
, **end
;
1824 start
= mod
->trace_events
;
1825 end
= mod
->trace_events
+ mod
->num_trace_events
;
1830 file_ops
= trace_create_file_ops(mod
);
1834 for_each_event(call
, start
, end
) {
1835 __register_event(*call
, mod
);
1836 __add_event_to_tracers(*call
, file_ops
);
1840 static void trace_module_remove_events(struct module
*mod
)
1842 struct ftrace_module_file_ops
*file_ops
;
1843 struct ftrace_event_call
*call
, *p
;
1844 bool clear_trace
= false;
1846 down_write(&trace_event_sem
);
1847 list_for_each_entry_safe(call
, p
, &ftrace_events
, list
) {
1848 if (call
->mod
== mod
) {
1849 if (call
->flags
& TRACE_EVENT_FL_WAS_ENABLED
)
1851 __trace_remove_event_call(call
);
1855 /* Now free the file_operations */
1856 list_for_each_entry(file_ops
, &ftrace_module_file_list
, list
) {
1857 if (file_ops
->mod
== mod
)
1860 if (&file_ops
->list
!= &ftrace_module_file_list
) {
1861 list_del(&file_ops
->list
);
1864 up_write(&trace_event_sem
);
1867 * It is safest to reset the ring buffer if the module being unloaded
1868 * registered any events that were used. The only worry is if
1869 * a new module gets loaded, and takes on the same id as the events
1870 * of this module. When printing out the buffer, traced events left
1871 * over from this module may be passed to the new module events and
1872 * unexpected results may occur.
1875 tracing_reset_all_online_cpus();
1878 static int trace_module_notify(struct notifier_block
*self
,
1879 unsigned long val
, void *data
)
1881 struct module
*mod
= data
;
1883 mutex_lock(&trace_types_lock
);
1884 mutex_lock(&event_mutex
);
1886 case MODULE_STATE_COMING
:
1887 trace_module_add_events(mod
);
1889 case MODULE_STATE_GOING
:
1890 trace_module_remove_events(mod
);
1893 mutex_unlock(&event_mutex
);
1894 mutex_unlock(&trace_types_lock
);
1900 __trace_add_new_mod_event(struct ftrace_event_call
*call
,
1901 struct trace_array
*tr
,
1902 struct ftrace_module_file_ops
*file_ops
)
1904 return __trace_add_new_event(call
, tr
,
1905 &file_ops
->id
, &file_ops
->enable
,
1906 &file_ops
->filter
, &file_ops
->format
);
1910 static inline struct ftrace_module_file_ops
*
1911 find_ftrace_file_ops(struct ftrace_module_file_ops
*file_ops
, struct module
*mod
)
1915 static inline int trace_module_notify(struct notifier_block
*self
,
1916 unsigned long val
, void *data
)
1921 __trace_add_new_mod_event(struct ftrace_event_call
*call
,
1922 struct trace_array
*tr
,
1923 struct ftrace_module_file_ops
*file_ops
)
1927 #endif /* CONFIG_MODULES */
1929 /* Create a new event directory structure for a trace directory. */
1931 __trace_add_event_dirs(struct trace_array
*tr
)
1933 struct ftrace_module_file_ops
*file_ops
= NULL
;
1934 struct ftrace_event_call
*call
;
1937 list_for_each_entry(call
, &ftrace_events
, list
) {
1940 * Directories for events by modules need to
1941 * keep module ref counts when opened (as we don't
1942 * want the module to disappear when reading one
1943 * of these files). The file_ops keep account of
1944 * the module ref count.
1946 file_ops
= find_ftrace_file_ops(file_ops
, call
->mod
);
1948 continue; /* Warn? */
1949 ret
= __trace_add_new_mod_event(call
, tr
, file_ops
);
1951 pr_warning("Could not create directory for event %s\n",
1955 ret
= __trace_add_new_event(call
, tr
,
1956 &ftrace_event_id_fops
,
1957 &ftrace_enable_fops
,
1958 &ftrace_event_filter_fops
,
1959 &ftrace_event_format_fops
);
1961 pr_warning("Could not create directory for event %s\n",
1966 #ifdef CONFIG_DYNAMIC_FTRACE
1969 #define ENABLE_EVENT_STR "enable_event"
1970 #define DISABLE_EVENT_STR "disable_event"
1972 struct event_probe_data
{
1973 struct ftrace_event_file
*file
;
1974 unsigned long count
;
1979 static struct ftrace_event_file
*
1980 find_event_file(struct trace_array
*tr
, const char *system
, const char *event
)
1982 struct ftrace_event_file
*file
;
1983 struct ftrace_event_call
*call
;
1985 list_for_each_entry(file
, &tr
->events
, list
) {
1987 call
= file
->event_call
;
1989 if (!call
->name
|| !call
->class || !call
->class->reg
)
1992 if (call
->flags
& TRACE_EVENT_FL_IGNORE_ENABLE
)
1995 if (strcmp(event
, call
->name
) == 0 &&
1996 strcmp(system
, call
->class->system
) == 0)
2003 event_enable_probe(unsigned long ip
, unsigned long parent_ip
, void **_data
)
2005 struct event_probe_data
**pdata
= (struct event_probe_data
**)_data
;
2006 struct event_probe_data
*data
= *pdata
;
2012 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT
, &data
->file
->flags
);
2014 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT
, &data
->file
->flags
);
2018 event_enable_count_probe(unsigned long ip
, unsigned long parent_ip
, void **_data
)
2020 struct event_probe_data
**pdata
= (struct event_probe_data
**)_data
;
2021 struct event_probe_data
*data
= *pdata
;
2029 /* Skip if the event is in a state we want to switch to */
2030 if (data
->enable
== !(data
->file
->flags
& FTRACE_EVENT_FL_SOFT_DISABLED
))
2033 if (data
->count
!= -1)
2036 event_enable_probe(ip
, parent_ip
, _data
);
2040 event_enable_print(struct seq_file
*m
, unsigned long ip
,
2041 struct ftrace_probe_ops
*ops
, void *_data
)
2043 struct event_probe_data
*data
= _data
;
2045 seq_printf(m
, "%ps:", (void *)ip
);
2047 seq_printf(m
, "%s:%s:%s",
2048 data
->enable
? ENABLE_EVENT_STR
: DISABLE_EVENT_STR
,
2049 data
->file
->event_call
->class->system
,
2050 data
->file
->event_call
->name
);
2052 if (data
->count
== -1)
2053 seq_printf(m
, ":unlimited\n");
2055 seq_printf(m
, ":count=%ld\n", data
->count
);
2061 event_enable_init(struct ftrace_probe_ops
*ops
, unsigned long ip
,
2064 struct event_probe_data
**pdata
= (struct event_probe_data
**)_data
;
2065 struct event_probe_data
*data
= *pdata
;
2072 event_enable_free(struct ftrace_probe_ops
*ops
, unsigned long ip
,
2075 struct event_probe_data
**pdata
= (struct event_probe_data
**)_data
;
2076 struct event_probe_data
*data
= *pdata
;
2078 if (WARN_ON_ONCE(data
->ref
<= 0))
2083 /* Remove the SOFT_MODE flag */
2084 __ftrace_event_enable_disable(data
->file
, 0, 1);
2085 module_put(data
->file
->event_call
->mod
);
2091 static struct ftrace_probe_ops event_enable_probe_ops
= {
2092 .func
= event_enable_probe
,
2093 .print
= event_enable_print
,
2094 .init
= event_enable_init
,
2095 .free
= event_enable_free
,
2098 static struct ftrace_probe_ops event_enable_count_probe_ops
= {
2099 .func
= event_enable_count_probe
,
2100 .print
= event_enable_print
,
2101 .init
= event_enable_init
,
2102 .free
= event_enable_free
,
2105 static struct ftrace_probe_ops event_disable_probe_ops
= {
2106 .func
= event_enable_probe
,
2107 .print
= event_enable_print
,
2108 .init
= event_enable_init
,
2109 .free
= event_enable_free
,
2112 static struct ftrace_probe_ops event_disable_count_probe_ops
= {
2113 .func
= event_enable_count_probe
,
2114 .print
= event_enable_print
,
2115 .init
= event_enable_init
,
2116 .free
= event_enable_free
,
2120 event_enable_func(struct ftrace_hash
*hash
,
2121 char *glob
, char *cmd
, char *param
, int enabled
)
2123 struct trace_array
*tr
= top_trace_array();
2124 struct ftrace_event_file
*file
;
2125 struct ftrace_probe_ops
*ops
;
2126 struct event_probe_data
*data
;
2133 /* hash funcs only work with set_ftrace_filter */
2134 if (!enabled
|| !param
)
2137 system
= strsep(¶m
, ":");
2141 event
= strsep(¶m
, ":");
2143 mutex_lock(&event_mutex
);
2146 file
= find_event_file(tr
, system
, event
);
2150 enable
= strcmp(cmd
, ENABLE_EVENT_STR
) == 0;
2153 ops
= param
? &event_enable_count_probe_ops
: &event_enable_probe_ops
;
2155 ops
= param
? &event_disable_count_probe_ops
: &event_disable_probe_ops
;
2157 if (glob
[0] == '!') {
2158 unregister_ftrace_function_probe_func(glob
+1, ops
);
2164 data
= kzalloc(sizeof(*data
), GFP_KERNEL
);
2168 data
->enable
= enable
;
2175 number
= strsep(¶m
, ":");
2178 if (!strlen(number
))
2182 * We use the callback data field (which is a pointer)
2185 ret
= kstrtoul(number
, 0, &data
->count
);
2190 /* Don't let event modules unload while probe registered */
2191 ret
= try_module_get(file
->event_call
->mod
);
2197 ret
= __ftrace_event_enable_disable(file
, 1, 1);
2200 ret
= register_ftrace_function_probe(glob
, ops
, data
);
2202 * The above returns on success the # of functions enabled,
2203 * but if it didn't find any functions it returns zero.
2204 * Consider no functions a failure too.
2211 /* Just return zero, not the number of enabled functions */
2214 mutex_unlock(&event_mutex
);
2218 __ftrace_event_enable_disable(file
, 0, 1);
2220 module_put(file
->event_call
->mod
);
2226 static struct ftrace_func_command event_enable_cmd
= {
2227 .name
= ENABLE_EVENT_STR
,
2228 .func
= event_enable_func
,
2231 static struct ftrace_func_command event_disable_cmd
= {
2232 .name
= DISABLE_EVENT_STR
,
2233 .func
= event_enable_func
,
2236 static __init
int register_event_cmds(void)
2240 ret
= register_ftrace_command(&event_enable_cmd
);
2241 if (WARN_ON(ret
< 0))
2243 ret
= register_ftrace_command(&event_disable_cmd
);
2244 if (WARN_ON(ret
< 0))
2245 unregister_ftrace_command(&event_enable_cmd
);
2249 static inline int register_event_cmds(void) { return 0; }
2250 #endif /* CONFIG_DYNAMIC_FTRACE */
2253 * The top level array has already had its ftrace_event_file
2254 * descriptors created in order to allow for early events to
2255 * be recorded. This function is called after the debugfs has been
2256 * initialized, and we now have to create the files associated
2260 __trace_early_add_event_dirs(struct trace_array
*tr
)
2262 struct ftrace_event_file
*file
;
2266 list_for_each_entry(file
, &tr
->events
, list
) {
2267 ret
= event_create_dir(tr
->event_dir
, file
,
2268 &ftrace_event_id_fops
,
2269 &ftrace_enable_fops
,
2270 &ftrace_event_filter_fops
,
2271 &ftrace_event_format_fops
);
2273 pr_warning("Could not create directory for event %s\n",
2274 file
->event_call
->name
);
2279 * For early boot up, the top trace array requires to have
2280 * a list of events that can be enabled. This must be done before
2281 * the filesystem is set up in order to allow events to be traced
2285 __trace_early_add_events(struct trace_array
*tr
)
2287 struct ftrace_event_call
*call
;
2290 list_for_each_entry(call
, &ftrace_events
, list
) {
2291 /* Early boot up should not have any modules loaded */
2292 if (WARN_ON_ONCE(call
->mod
))
2295 ret
= __trace_early_add_new_event(call
, tr
);
2297 pr_warning("Could not create early event %s\n",
2302 /* Remove the event directory structure for a trace directory. */
2304 __trace_remove_event_dirs(struct trace_array
*tr
)
2306 struct ftrace_event_file
*file
, *next
;
2308 list_for_each_entry_safe(file
, next
, &tr
->events
, list
) {
2309 list_del(&file
->list
);
2310 debugfs_remove_recursive(file
->dir
);
2311 remove_subsystem(file
->system
);
2312 kmem_cache_free(file_cachep
, file
);
2317 __add_event_to_tracers(struct ftrace_event_call
*call
,
2318 struct ftrace_module_file_ops
*file_ops
)
2320 struct trace_array
*tr
;
2322 list_for_each_entry(tr
, &ftrace_trace_arrays
, list
) {
2324 __trace_add_new_mod_event(call
, tr
, file_ops
);
2326 __trace_add_new_event(call
, tr
,
2327 &ftrace_event_id_fops
,
2328 &ftrace_enable_fops
,
2329 &ftrace_event_filter_fops
,
2330 &ftrace_event_format_fops
);
2334 static struct notifier_block trace_module_nb
= {
2335 .notifier_call
= trace_module_notify
,
2339 extern struct ftrace_event_call
*__start_ftrace_events
[];
2340 extern struct ftrace_event_call
*__stop_ftrace_events
[];
2342 static char bootup_event_buf
[COMMAND_LINE_SIZE
] __initdata
;
2344 static __init
int setup_trace_event(char *str
)
2346 strlcpy(bootup_event_buf
, str
, COMMAND_LINE_SIZE
);
2347 ring_buffer_expanded
= true;
2348 tracing_selftest_disabled
= true;
2352 __setup("trace_event=", setup_trace_event
);
2354 /* Expects to have event_mutex held when called */
2356 create_event_toplevel_files(struct dentry
*parent
, struct trace_array
*tr
)
2358 struct dentry
*d_events
;
2359 struct dentry
*entry
;
2361 entry
= debugfs_create_file("set_event", 0644, parent
,
2362 tr
, &ftrace_set_event_fops
);
2364 pr_warning("Could not create debugfs 'set_event' entry\n");
2368 d_events
= debugfs_create_dir("events", parent
);
2370 pr_warning("Could not create debugfs 'events' directory\n");
2374 /* ring buffer internal formats */
2375 trace_create_file("header_page", 0444, d_events
,
2376 ring_buffer_print_page_header
,
2377 &ftrace_show_header_fops
);
2379 trace_create_file("header_event", 0444, d_events
,
2380 ring_buffer_print_entry_header
,
2381 &ftrace_show_header_fops
);
2383 trace_create_file("enable", 0644, d_events
,
2384 tr
, &ftrace_tr_enable_fops
);
2386 tr
->event_dir
= d_events
;
2392 * event_trace_add_tracer - add a instance of a trace_array to events
2393 * @parent: The parent dentry to place the files/directories for events in
2394 * @tr: The trace array associated with these events
2396 * When a new instance is created, it needs to set up its events
2397 * directory, as well as other files associated with events. It also
2398 * creates the event hierachry in the @parent/events directory.
2400 * Returns 0 on success.
2402 int event_trace_add_tracer(struct dentry
*parent
, struct trace_array
*tr
)
2406 mutex_lock(&event_mutex
);
2408 ret
= create_event_toplevel_files(parent
, tr
);
2412 down_write(&trace_event_sem
);
2413 __trace_add_event_dirs(tr
);
2414 up_write(&trace_event_sem
);
2417 mutex_unlock(&event_mutex
);
2423 * The top trace array already had its file descriptors created.
2424 * Now the files themselves need to be created.
2427 early_event_add_tracer(struct dentry
*parent
, struct trace_array
*tr
)
2431 mutex_lock(&event_mutex
);
2433 ret
= create_event_toplevel_files(parent
, tr
);
2437 down_write(&trace_event_sem
);
2438 __trace_early_add_event_dirs(tr
);
2439 up_write(&trace_event_sem
);
2442 mutex_unlock(&event_mutex
);
2447 int event_trace_del_tracer(struct trace_array
*tr
)
2449 mutex_lock(&event_mutex
);
2451 /* Disable any running events */
2452 __ftrace_set_clr_event_nolock(tr
, NULL
, NULL
, NULL
, 0);
2454 down_write(&trace_event_sem
);
2455 __trace_remove_event_dirs(tr
);
2456 debugfs_remove_recursive(tr
->event_dir
);
2457 up_write(&trace_event_sem
);
2459 tr
->event_dir
= NULL
;
2461 mutex_unlock(&event_mutex
);
2466 static __init
int event_trace_memsetup(void)
2468 field_cachep
= KMEM_CACHE(ftrace_event_field
, SLAB_PANIC
);
2469 file_cachep
= KMEM_CACHE(ftrace_event_file
, SLAB_PANIC
);
2473 static __init
int event_trace_enable(void)
2475 struct trace_array
*tr
= top_trace_array();
2476 struct ftrace_event_call
**iter
, *call
;
2477 char *buf
= bootup_event_buf
;
2481 for_each_event(iter
, __start_ftrace_events
, __stop_ftrace_events
) {
2484 ret
= event_init(call
);
2486 list_add(&call
->list
, &ftrace_events
);
2490 * We need the top trace array to have a working set of trace
2491 * points at early init, before the debug files and directories
2492 * are created. Create the file entries now, and attach them
2493 * to the actual file dentries later.
2495 __trace_early_add_events(tr
);
2498 token
= strsep(&buf
, ",");
2505 ret
= ftrace_set_clr_event(tr
, token
, 1);
2507 pr_warn("Failed to enable trace event: %s\n", token
);
2510 trace_printk_start_comm();
2512 register_event_cmds();
2517 static __init
int event_trace_init(void)
2519 struct trace_array
*tr
;
2520 struct dentry
*d_tracer
;
2521 struct dentry
*entry
;
2524 tr
= top_trace_array();
2526 d_tracer
= tracing_init_dentry();
2530 entry
= debugfs_create_file("available_events", 0444, d_tracer
,
2531 tr
, &ftrace_avail_fops
);
2533 pr_warning("Could not create debugfs "
2534 "'available_events' entry\n");
2536 if (trace_define_common_fields())
2537 pr_warning("tracing: Failed to allocate common fields");
2539 ret
= early_event_add_tracer(d_tracer
, tr
);
2543 ret
= register_module_notifier(&trace_module_nb
);
2545 pr_warning("Failed to register trace events module notifier\n");
2549 early_initcall(event_trace_memsetup
);
2550 core_initcall(event_trace_enable
);
2551 fs_initcall(event_trace_init
);
2553 #ifdef CONFIG_FTRACE_STARTUP_TEST
2555 static DEFINE_SPINLOCK(test_spinlock
);
2556 static DEFINE_SPINLOCK(test_spinlock_irq
);
2557 static DEFINE_MUTEX(test_mutex
);
2559 static __init
void test_work(struct work_struct
*dummy
)
2561 spin_lock(&test_spinlock
);
2562 spin_lock_irq(&test_spinlock_irq
);
2564 spin_unlock_irq(&test_spinlock_irq
);
2565 spin_unlock(&test_spinlock
);
2567 mutex_lock(&test_mutex
);
2569 mutex_unlock(&test_mutex
);
2572 static __init
int event_test_thread(void *unused
)
2576 test_malloc
= kmalloc(1234, GFP_KERNEL
);
2578 pr_info("failed to kmalloc\n");
2580 schedule_on_each_cpu(test_work
);
2584 set_current_state(TASK_INTERRUPTIBLE
);
2585 while (!kthread_should_stop())
2592 * Do various things that may trigger events.
2594 static __init
void event_test_stuff(void)
2596 struct task_struct
*test_thread
;
2598 test_thread
= kthread_run(event_test_thread
, NULL
, "test-events");
2600 kthread_stop(test_thread
);
2604 * For every trace event defined, we will test each trace point separately,
2605 * and then by groups, and finally all trace points.
2607 static __init
void event_trace_self_tests(void)
2609 struct ftrace_subsystem_dir
*dir
;
2610 struct ftrace_event_file
*file
;
2611 struct ftrace_event_call
*call
;
2612 struct event_subsystem
*system
;
2613 struct trace_array
*tr
;
2616 tr
= top_trace_array();
2618 pr_info("Running tests on trace events:\n");
2620 list_for_each_entry(file
, &tr
->events
, list
) {
2622 call
= file
->event_call
;
2624 /* Only test those that have a probe */
2625 if (!call
->class || !call
->class->probe
)
2629 * Testing syscall events here is pretty useless, but
2630 * we still do it if configured. But this is time consuming.
2631 * What we really need is a user thread to perform the
2632 * syscalls as we test.
2634 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
2635 if (call
->class->system
&&
2636 strcmp(call
->class->system
, "syscalls") == 0)
2640 pr_info("Testing event %s: ", call
->name
);
2643 * If an event is already enabled, someone is using
2644 * it and the self test should not be on.
2646 if (file
->flags
& FTRACE_EVENT_FL_ENABLED
) {
2647 pr_warning("Enabled event during self test!\n");
2652 ftrace_event_enable_disable(file
, 1);
2654 ftrace_event_enable_disable(file
, 0);
2659 /* Now test at the sub system level */
2661 pr_info("Running tests on trace event systems:\n");
2663 list_for_each_entry(dir
, &tr
->systems
, list
) {
2665 system
= dir
->subsystem
;
2667 /* the ftrace system is special, skip it */
2668 if (strcmp(system
->name
, "ftrace") == 0)
2671 pr_info("Testing event system %s: ", system
->name
);
2673 ret
= __ftrace_set_clr_event(tr
, NULL
, system
->name
, NULL
, 1);
2674 if (WARN_ON_ONCE(ret
)) {
2675 pr_warning("error enabling system %s\n",
2682 ret
= __ftrace_set_clr_event(tr
, NULL
, system
->name
, NULL
, 0);
2683 if (WARN_ON_ONCE(ret
)) {
2684 pr_warning("error disabling system %s\n",
2692 /* Test with all events enabled */
2694 pr_info("Running tests on all trace events:\n");
2695 pr_info("Testing all events: ");
2697 ret
= __ftrace_set_clr_event(tr
, NULL
, NULL
, NULL
, 1);
2698 if (WARN_ON_ONCE(ret
)) {
2699 pr_warning("error enabling all events\n");
2706 ret
= __ftrace_set_clr_event(tr
, NULL
, NULL
, NULL
, 0);
2707 if (WARN_ON_ONCE(ret
)) {
2708 pr_warning("error disabling all events\n");
2715 #ifdef CONFIG_FUNCTION_TRACER
2717 static DEFINE_PER_CPU(atomic_t
, ftrace_test_event_disable
);
2720 function_test_events_call(unsigned long ip
, unsigned long parent_ip
,
2721 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
2723 struct ring_buffer_event
*event
;
2724 struct ring_buffer
*buffer
;
2725 struct ftrace_entry
*entry
;
2726 unsigned long flags
;
2731 pc
= preempt_count();
2732 preempt_disable_notrace();
2733 cpu
= raw_smp_processor_id();
2734 disabled
= atomic_inc_return(&per_cpu(ftrace_test_event_disable
, cpu
));
2739 local_save_flags(flags
);
2741 event
= trace_current_buffer_lock_reserve(&buffer
,
2742 TRACE_FN
, sizeof(*entry
),
2746 entry
= ring_buffer_event_data(event
);
2748 entry
->parent_ip
= parent_ip
;
2750 trace_buffer_unlock_commit(buffer
, event
, flags
, pc
);
2753 atomic_dec(&per_cpu(ftrace_test_event_disable
, cpu
));
2754 preempt_enable_notrace();
2757 static struct ftrace_ops trace_ops __initdata
=
2759 .func
= function_test_events_call
,
2760 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
,
2763 static __init
void event_trace_self_test_with_function(void)
2766 ret
= register_ftrace_function(&trace_ops
);
2767 if (WARN_ON(ret
< 0)) {
2768 pr_info("Failed to enable function tracer for event tests\n");
2771 pr_info("Running tests again, along with the function tracer\n");
2772 event_trace_self_tests();
2773 unregister_ftrace_function(&trace_ops
);
2776 static __init
void event_trace_self_test_with_function(void)
2781 static __init
int event_trace_self_tests_init(void)
2783 if (!tracing_selftest_disabled
) {
2784 event_trace_self_tests();
2785 event_trace_self_test_with_function();
2791 late_initcall(event_trace_self_tests_init
);