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 LIST_HEAD(ftrace_common_fields
);
40 trace_get_fields(struct ftrace_event_call
*event_call
)
42 if (!event_call
->class->get_fields
)
43 return &event_call
->class->fields
;
44 return event_call
->class->get_fields(event_call
);
47 static int __trace_define_field(struct list_head
*head
, const char *type
,
48 const char *name
, int offset
, int size
,
49 int is_signed
, int filter_type
)
51 struct ftrace_event_field
*field
;
53 field
= kzalloc(sizeof(*field
), GFP_KERNEL
);
57 field
->name
= kstrdup(name
, GFP_KERNEL
);
61 field
->type
= kstrdup(type
, GFP_KERNEL
);
65 if (filter_type
== FILTER_OTHER
)
66 field
->filter_type
= filter_assign_type(type
);
68 field
->filter_type
= filter_type
;
70 field
->offset
= offset
;
72 field
->is_signed
= is_signed
;
74 list_add(&field
->link
, head
);
86 int trace_define_field(struct ftrace_event_call
*call
, const char *type
,
87 const char *name
, int offset
, int size
, int is_signed
,
90 struct list_head
*head
;
92 if (WARN_ON(!call
->class))
95 head
= trace_get_fields(call
);
96 return __trace_define_field(head
, type
, name
, offset
, size
,
97 is_signed
, filter_type
);
99 EXPORT_SYMBOL_GPL(trace_define_field
);
101 #define __common_field(type, item) \
102 ret = __trace_define_field(&ftrace_common_fields, #type, \
104 offsetof(typeof(ent), item), \
106 is_signed_type(type), FILTER_OTHER); \
110 static int trace_define_common_fields(void)
113 struct trace_entry ent
;
115 __common_field(unsigned short, type
);
116 __common_field(unsigned char, flags
);
117 __common_field(unsigned char, preempt_count
);
118 __common_field(int, pid
);
119 __common_field(int, padding
);
124 void trace_destroy_fields(struct ftrace_event_call
*call
)
126 struct ftrace_event_field
*field
, *next
;
127 struct list_head
*head
;
129 head
= trace_get_fields(call
);
130 list_for_each_entry_safe(field
, next
, head
, link
) {
131 list_del(&field
->link
);
138 int trace_event_raw_init(struct ftrace_event_call
*call
)
142 id
= register_ftrace_event(&call
->event
);
148 EXPORT_SYMBOL_GPL(trace_event_raw_init
);
150 int ftrace_event_reg(struct ftrace_event_call
*call
,
151 enum trace_reg type
, void *data
)
154 case TRACE_REG_REGISTER
:
155 return tracepoint_probe_register(call
->name
,
158 case TRACE_REG_UNREGISTER
:
159 tracepoint_probe_unregister(call
->name
,
164 #ifdef CONFIG_PERF_EVENTS
165 case TRACE_REG_PERF_REGISTER
:
166 return tracepoint_probe_register(call
->name
,
167 call
->class->perf_probe
,
169 case TRACE_REG_PERF_UNREGISTER
:
170 tracepoint_probe_unregister(call
->name
,
171 call
->class->perf_probe
,
174 case TRACE_REG_PERF_OPEN
:
175 case TRACE_REG_PERF_CLOSE
:
176 case TRACE_REG_PERF_ADD
:
177 case TRACE_REG_PERF_DEL
:
183 EXPORT_SYMBOL_GPL(ftrace_event_reg
);
185 void trace_event_enable_cmd_record(bool enable
)
187 struct ftrace_event_call
*call
;
189 mutex_lock(&event_mutex
);
190 list_for_each_entry(call
, &ftrace_events
, list
) {
191 if (!(call
->flags
& TRACE_EVENT_FL_ENABLED
))
195 tracing_start_cmdline_record();
196 call
->flags
|= TRACE_EVENT_FL_RECORDED_CMD
;
198 tracing_stop_cmdline_record();
199 call
->flags
&= ~TRACE_EVENT_FL_RECORDED_CMD
;
202 mutex_unlock(&event_mutex
);
205 static int ftrace_event_enable_disable(struct ftrace_event_call
*call
,
212 if (call
->flags
& TRACE_EVENT_FL_ENABLED
) {
213 call
->flags
&= ~TRACE_EVENT_FL_ENABLED
;
214 if (call
->flags
& TRACE_EVENT_FL_RECORDED_CMD
) {
215 tracing_stop_cmdline_record();
216 call
->flags
&= ~TRACE_EVENT_FL_RECORDED_CMD
;
218 call
->class->reg(call
, TRACE_REG_UNREGISTER
, NULL
);
222 if (!(call
->flags
& TRACE_EVENT_FL_ENABLED
)) {
223 if (trace_flags
& TRACE_ITER_RECORD_CMD
) {
224 tracing_start_cmdline_record();
225 call
->flags
|= TRACE_EVENT_FL_RECORDED_CMD
;
227 ret
= call
->class->reg(call
, TRACE_REG_REGISTER
, NULL
);
229 tracing_stop_cmdline_record();
230 pr_info("event trace: Could not enable event "
234 call
->flags
|= TRACE_EVENT_FL_ENABLED
;
242 static void ftrace_clear_events(void)
244 struct ftrace_event_call
*call
;
246 mutex_lock(&event_mutex
);
247 list_for_each_entry(call
, &ftrace_events
, list
) {
248 ftrace_event_enable_disable(call
, 0);
250 mutex_unlock(&event_mutex
);
253 static void __put_system(struct event_subsystem
*system
)
255 struct event_filter
*filter
= system
->filter
;
257 WARN_ON_ONCE(system
->ref_count
== 0);
258 if (--system
->ref_count
)
262 kfree(filter
->filter_string
);
269 static void __get_system(struct event_subsystem
*system
)
271 WARN_ON_ONCE(system
->ref_count
== 0);
275 static void put_system(struct event_subsystem
*system
)
277 mutex_lock(&event_mutex
);
278 __put_system(system
);
279 mutex_unlock(&event_mutex
);
283 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
285 static int __ftrace_set_clr_event(const char *match
, const char *sub
,
286 const char *event
, int set
)
288 struct ftrace_event_call
*call
;
291 mutex_lock(&event_mutex
);
292 list_for_each_entry(call
, &ftrace_events
, list
) {
294 if (!call
->name
|| !call
->class || !call
->class->reg
)
297 if (call
->flags
& TRACE_EVENT_FL_IGNORE_ENABLE
)
301 strcmp(match
, call
->name
) != 0 &&
302 strcmp(match
, call
->class->system
) != 0)
305 if (sub
&& strcmp(sub
, call
->class->system
) != 0)
308 if (event
&& strcmp(event
, call
->name
) != 0)
311 ftrace_event_enable_disable(call
, set
);
315 mutex_unlock(&event_mutex
);
320 static int ftrace_set_clr_event(char *buf
, int set
)
322 char *event
= NULL
, *sub
= NULL
, *match
;
325 * The buf format can be <subsystem>:<event-name>
326 * *:<event-name> means any event by that name.
327 * :<event-name> is the same.
329 * <subsystem>:* means all events in that subsystem
330 * <subsystem>: means the same.
332 * <name> (no ':') means all events in a subsystem with
333 * the name <name> or any event that matches <name>
336 match
= strsep(&buf
, ":");
342 if (!strlen(sub
) || strcmp(sub
, "*") == 0)
344 if (!strlen(event
) || strcmp(event
, "*") == 0)
348 return __ftrace_set_clr_event(match
, sub
, event
, set
);
352 * trace_set_clr_event - enable or disable an event
353 * @system: system name to match (NULL for any system)
354 * @event: event name to match (NULL for all events, within system)
355 * @set: 1 to enable, 0 to disable
357 * This is a way for other parts of the kernel to enable or disable
360 * Returns 0 on success, -EINVAL if the parameters do not match any
363 int trace_set_clr_event(const char *system
, const char *event
, int set
)
365 return __ftrace_set_clr_event(NULL
, system
, event
, set
);
367 EXPORT_SYMBOL_GPL(trace_set_clr_event
);
369 /* 128 should be much more than enough */
370 #define EVENT_BUF_SIZE 127
373 ftrace_event_write(struct file
*file
, const char __user
*ubuf
,
374 size_t cnt
, loff_t
*ppos
)
376 struct trace_parser parser
;
382 ret
= tracing_update_buffers();
386 if (trace_parser_get_init(&parser
, EVENT_BUF_SIZE
+ 1))
389 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
391 if (read
>= 0 && trace_parser_loaded((&parser
))) {
394 if (*parser
.buffer
== '!')
397 parser
.buffer
[parser
.idx
] = 0;
399 ret
= ftrace_set_clr_event(parser
.buffer
+ !set
, set
);
407 trace_parser_put(&parser
);
413 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
415 struct ftrace_event_call
*call
= v
;
419 list_for_each_entry_continue(call
, &ftrace_events
, list
) {
421 * The ftrace subsystem is for showing formats only.
422 * They can not be enabled or disabled via the event files.
424 if (call
->class && call
->class->reg
)
431 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
433 struct ftrace_event_call
*call
;
436 mutex_lock(&event_mutex
);
438 call
= list_entry(&ftrace_events
, struct ftrace_event_call
, list
);
439 for (l
= 0; l
<= *pos
; ) {
440 call
= t_next(m
, call
, &l
);
448 s_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
450 struct ftrace_event_call
*call
= v
;
454 list_for_each_entry_continue(call
, &ftrace_events
, list
) {
455 if (call
->flags
& TRACE_EVENT_FL_ENABLED
)
462 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
464 struct ftrace_event_call
*call
;
467 mutex_lock(&event_mutex
);
469 call
= list_entry(&ftrace_events
, struct ftrace_event_call
, list
);
470 for (l
= 0; l
<= *pos
; ) {
471 call
= s_next(m
, call
, &l
);
478 static int t_show(struct seq_file
*m
, void *v
)
480 struct ftrace_event_call
*call
= v
;
482 if (strcmp(call
->class->system
, TRACE_SYSTEM
) != 0)
483 seq_printf(m
, "%s:", call
->class->system
);
484 seq_printf(m
, "%s\n", call
->name
);
489 static void t_stop(struct seq_file
*m
, void *p
)
491 mutex_unlock(&event_mutex
);
495 event_enable_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
498 struct ftrace_event_call
*call
= filp
->private_data
;
501 if (call
->flags
& TRACE_EVENT_FL_ENABLED
)
506 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, 2);
510 event_enable_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
513 struct ftrace_event_call
*call
= filp
->private_data
;
517 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
521 ret
= tracing_update_buffers();
528 mutex_lock(&event_mutex
);
529 ret
= ftrace_event_enable_disable(call
, val
);
530 mutex_unlock(&event_mutex
);
539 return ret
? ret
: cnt
;
543 system_enable_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
546 const char set_to_char
[4] = { '?', '0', '1', 'X' };
547 struct event_subsystem
*system
= filp
->private_data
;
548 struct ftrace_event_call
*call
;
553 mutex_lock(&event_mutex
);
554 list_for_each_entry(call
, &ftrace_events
, list
) {
555 if (!call
->name
|| !call
->class || !call
->class->reg
)
558 if (system
&& strcmp(call
->class->system
, system
->name
) != 0)
562 * We need to find out if all the events are set
563 * or if all events or cleared, or if we have
566 set
|= (1 << !!(call
->flags
& TRACE_EVENT_FL_ENABLED
));
569 * If we have a mixture, no need to look further.
574 mutex_unlock(&event_mutex
);
576 buf
[0] = set_to_char
[set
];
579 ret
= simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, 2);
585 system_enable_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
588 struct event_subsystem
*system
= filp
->private_data
;
589 const char *name
= NULL
;
593 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
597 ret
= tracing_update_buffers();
601 if (val
!= 0 && val
!= 1)
605 * Opening of "enable" adds a ref count to system,
606 * so the name is safe to use.
611 ret
= __ftrace_set_clr_event(NULL
, name
, NULL
, val
);
625 FORMAT_FIELD_SEPERATOR
= 2,
629 static void *f_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
631 struct ftrace_event_call
*call
= m
->private;
632 struct ftrace_event_field
*field
;
633 struct list_head
*common_head
= &ftrace_common_fields
;
634 struct list_head
*head
= trace_get_fields(call
);
638 switch ((unsigned long)v
) {
640 if (unlikely(list_empty(common_head
)))
643 field
= list_entry(common_head
->prev
,
644 struct ftrace_event_field
, link
);
647 case FORMAT_FIELD_SEPERATOR
:
648 if (unlikely(list_empty(head
)))
651 field
= list_entry(head
->prev
, struct ftrace_event_field
, link
);
654 case FORMAT_PRINTFMT
:
660 if (field
->link
.prev
== common_head
)
661 return (void *)FORMAT_FIELD_SEPERATOR
;
662 else if (field
->link
.prev
== head
)
663 return (void *)FORMAT_PRINTFMT
;
665 field
= list_entry(field
->link
.prev
, struct ftrace_event_field
, link
);
670 static void *f_start(struct seq_file
*m
, loff_t
*pos
)
675 /* Start by showing the header */
677 return (void *)FORMAT_HEADER
;
679 p
= (void *)FORMAT_HEADER
;
681 p
= f_next(m
, p
, &l
);
682 } while (p
&& l
< *pos
);
687 static int f_show(struct seq_file
*m
, void *v
)
689 struct ftrace_event_call
*call
= m
->private;
690 struct ftrace_event_field
*field
;
691 const char *array_descriptor
;
693 switch ((unsigned long)v
) {
695 seq_printf(m
, "name: %s\n", call
->name
);
696 seq_printf(m
, "ID: %d\n", call
->event
.type
);
697 seq_printf(m
, "format:\n");
700 case FORMAT_FIELD_SEPERATOR
:
704 case FORMAT_PRINTFMT
:
705 seq_printf(m
, "\nprint fmt: %s\n",
713 * Smartly shows the array type(except dynamic array).
716 * If TYPE := TYPE[LEN], it is shown:
717 * field:TYPE VAR[LEN]
719 array_descriptor
= strchr(field
->type
, '[');
721 if (!strncmp(field
->type
, "__data_loc", 10))
722 array_descriptor
= NULL
;
724 if (!array_descriptor
)
725 seq_printf(m
, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
726 field
->type
, field
->name
, field
->offset
,
727 field
->size
, !!field
->is_signed
);
729 seq_printf(m
, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
730 (int)(array_descriptor
- field
->type
),
731 field
->type
, field
->name
,
732 array_descriptor
, field
->offset
,
733 field
->size
, !!field
->is_signed
);
738 static void f_stop(struct seq_file
*m
, void *p
)
742 static const struct seq_operations trace_format_seq_ops
= {
749 static int trace_format_open(struct inode
*inode
, struct file
*file
)
751 struct ftrace_event_call
*call
= inode
->i_private
;
755 ret
= seq_open(file
, &trace_format_seq_ops
);
759 m
= file
->private_data
;
766 event_id_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
, loff_t
*ppos
)
768 struct ftrace_event_call
*call
= filp
->private_data
;
775 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
780 trace_seq_printf(s
, "%d\n", call
->event
.type
);
782 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
,
789 event_filter_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
792 struct ftrace_event_call
*call
= filp
->private_data
;
799 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
805 print_event_filter(call
, s
);
806 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, s
->buffer
, s
->len
);
814 event_filter_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
817 struct ftrace_event_call
*call
= filp
->private_data
;
821 if (cnt
>= PAGE_SIZE
)
824 buf
= (char *)__get_free_page(GFP_TEMPORARY
);
828 if (copy_from_user(buf
, ubuf
, cnt
)) {
829 free_page((unsigned long) buf
);
834 err
= apply_event_filter(call
, buf
);
835 free_page((unsigned long) buf
);
844 static LIST_HEAD(event_subsystems
);
846 static int subsystem_open(struct inode
*inode
, struct file
*filp
)
848 struct event_subsystem
*system
= NULL
;
851 if (!inode
->i_private
)
854 /* Make sure the system still exists */
855 mutex_lock(&event_mutex
);
856 list_for_each_entry(system
, &event_subsystems
, list
) {
857 if (system
== inode
->i_private
) {
858 /* Don't open systems with no events */
859 if (!system
->nr_events
) {
863 __get_system(system
);
867 mutex_unlock(&event_mutex
);
869 if (system
!= inode
->i_private
)
873 ret
= tracing_open_generic(inode
, filp
);
874 if (ret
< 0 && system
)
880 static int subsystem_release(struct inode
*inode
, struct file
*file
)
882 struct event_subsystem
*system
= inode
->i_private
;
891 subsystem_filter_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
894 struct event_subsystem
*system
= filp
->private_data
;
901 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
907 print_subsystem_event_filter(system
, s
);
908 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, s
->buffer
, s
->len
);
916 subsystem_filter_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
919 struct event_subsystem
*system
= filp
->private_data
;
923 if (cnt
>= PAGE_SIZE
)
926 buf
= (char *)__get_free_page(GFP_TEMPORARY
);
930 if (copy_from_user(buf
, ubuf
, cnt
)) {
931 free_page((unsigned long) buf
);
936 err
= apply_subsystem_event_filter(system
, buf
);
937 free_page((unsigned long) buf
);
947 show_header(struct file
*filp
, char __user
*ubuf
, size_t cnt
, loff_t
*ppos
)
949 int (*func
)(struct trace_seq
*s
) = filp
->private_data
;
956 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
963 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, s
->buffer
, s
->len
);
970 static int ftrace_event_avail_open(struct inode
*inode
, struct file
*file
);
971 static int ftrace_event_set_open(struct inode
*inode
, struct file
*file
);
973 static const struct seq_operations show_event_seq_ops
= {
980 static const struct seq_operations show_set_event_seq_ops
= {
987 static const struct file_operations ftrace_avail_fops
= {
988 .open
= ftrace_event_avail_open
,
991 .release
= seq_release
,
994 static const struct file_operations ftrace_set_event_fops
= {
995 .open
= ftrace_event_set_open
,
997 .write
= ftrace_event_write
,
999 .release
= seq_release
,
1002 static const struct file_operations ftrace_enable_fops
= {
1003 .open
= tracing_open_generic
,
1004 .read
= event_enable_read
,
1005 .write
= event_enable_write
,
1006 .llseek
= default_llseek
,
1009 static const struct file_operations ftrace_event_format_fops
= {
1010 .open
= trace_format_open
,
1012 .llseek
= seq_lseek
,
1013 .release
= seq_release
,
1016 static const struct file_operations ftrace_event_id_fops
= {
1017 .open
= tracing_open_generic
,
1018 .read
= event_id_read
,
1019 .llseek
= default_llseek
,
1022 static const struct file_operations ftrace_event_filter_fops
= {
1023 .open
= tracing_open_generic
,
1024 .read
= event_filter_read
,
1025 .write
= event_filter_write
,
1026 .llseek
= default_llseek
,
1029 static const struct file_operations ftrace_subsystem_filter_fops
= {
1030 .open
= subsystem_open
,
1031 .read
= subsystem_filter_read
,
1032 .write
= subsystem_filter_write
,
1033 .llseek
= default_llseek
,
1034 .release
= subsystem_release
,
1037 static const struct file_operations ftrace_system_enable_fops
= {
1038 .open
= subsystem_open
,
1039 .read
= system_enable_read
,
1040 .write
= system_enable_write
,
1041 .llseek
= default_llseek
,
1042 .release
= subsystem_release
,
1045 static const struct file_operations ftrace_show_header_fops
= {
1046 .open
= tracing_open_generic
,
1047 .read
= show_header
,
1048 .llseek
= default_llseek
,
1051 static struct dentry
*event_trace_events_dir(void)
1053 static struct dentry
*d_tracer
;
1054 static struct dentry
*d_events
;
1059 d_tracer
= tracing_init_dentry();
1063 d_events
= debugfs_create_dir("events", d_tracer
);
1065 pr_warning("Could not create debugfs "
1066 "'events' directory\n");
1072 ftrace_event_avail_open(struct inode
*inode
, struct file
*file
)
1074 const struct seq_operations
*seq_ops
= &show_event_seq_ops
;
1076 return seq_open(file
, seq_ops
);
1080 ftrace_event_set_open(struct inode
*inode
, struct file
*file
)
1082 const struct seq_operations
*seq_ops
= &show_set_event_seq_ops
;
1084 if ((file
->f_mode
& FMODE_WRITE
) &&
1085 (file
->f_flags
& O_TRUNC
))
1086 ftrace_clear_events();
1088 return seq_open(file
, seq_ops
);
1091 static struct dentry
*
1092 event_subsystem_dir(const char *name
, struct dentry
*d_events
)
1094 struct event_subsystem
*system
;
1095 struct dentry
*entry
;
1097 /* First see if we did not already create this dir */
1098 list_for_each_entry(system
, &event_subsystems
, list
) {
1099 if (strcmp(system
->name
, name
) == 0) {
1100 system
->nr_events
++;
1101 return system
->entry
;
1105 /* need to create new entry */
1106 system
= kmalloc(sizeof(*system
), GFP_KERNEL
);
1108 pr_warning("No memory to create event subsystem %s\n",
1113 system
->entry
= debugfs_create_dir(name
, d_events
);
1114 if (!system
->entry
) {
1115 pr_warning("Could not create event subsystem %s\n",
1121 system
->nr_events
= 1;
1122 system
->ref_count
= 1;
1123 system
->name
= kstrdup(name
, GFP_KERNEL
);
1124 if (!system
->name
) {
1125 debugfs_remove(system
->entry
);
1130 list_add(&system
->list
, &event_subsystems
);
1132 system
->filter
= NULL
;
1134 system
->filter
= kzalloc(sizeof(struct event_filter
), GFP_KERNEL
);
1135 if (!system
->filter
) {
1136 pr_warning("Could not allocate filter for subsystem "
1138 return system
->entry
;
1141 entry
= debugfs_create_file("filter", 0644, system
->entry
, system
,
1142 &ftrace_subsystem_filter_fops
);
1144 kfree(system
->filter
);
1145 system
->filter
= NULL
;
1146 pr_warning("Could not create debugfs "
1147 "'%s/filter' entry\n", name
);
1150 trace_create_file("enable", 0644, system
->entry
, system
,
1151 &ftrace_system_enable_fops
);
1153 return system
->entry
;
1157 event_create_dir(struct ftrace_event_call
*call
, struct dentry
*d_events
,
1158 const struct file_operations
*id
,
1159 const struct file_operations
*enable
,
1160 const struct file_operations
*filter
,
1161 const struct file_operations
*format
)
1163 struct list_head
*head
;
1167 * If the trace point header did not define TRACE_SYSTEM
1168 * then the system would be called "TRACE_SYSTEM".
1170 if (strcmp(call
->class->system
, TRACE_SYSTEM
) != 0)
1171 d_events
= event_subsystem_dir(call
->class->system
, d_events
);
1173 call
->dir
= debugfs_create_dir(call
->name
, d_events
);
1175 pr_warning("Could not create debugfs "
1176 "'%s' directory\n", call
->name
);
1180 if (call
->class->reg
&& !(call
->flags
& TRACE_EVENT_FL_IGNORE_ENABLE
))
1181 trace_create_file("enable", 0644, call
->dir
, call
,
1184 #ifdef CONFIG_PERF_EVENTS
1185 if (call
->event
.type
&& call
->class->reg
)
1186 trace_create_file("id", 0444, call
->dir
, call
,
1191 * Other events may have the same class. Only update
1192 * the fields if they are not already defined.
1194 head
= trace_get_fields(call
);
1195 if (list_empty(head
)) {
1196 ret
= call
->class->define_fields(call
);
1198 pr_warning("Could not initialize trace point"
1199 " events/%s\n", call
->name
);
1203 trace_create_file("filter", 0644, call
->dir
, call
,
1206 trace_create_file("format", 0444, call
->dir
, call
,
1212 static void event_remove(struct ftrace_event_call
*call
)
1214 ftrace_event_enable_disable(call
, 0);
1215 if (call
->event
.funcs
)
1216 __unregister_ftrace_event(&call
->event
);
1217 list_del(&call
->list
);
1220 static int event_init(struct ftrace_event_call
*call
)
1224 if (WARN_ON(!call
->name
))
1227 if (call
->class->raw_init
) {
1228 ret
= call
->class->raw_init(call
);
1229 if (ret
< 0 && ret
!= -ENOSYS
)
1230 pr_warn("Could not initialize trace events/%s\n",
1238 __trace_add_event_call(struct ftrace_event_call
*call
, struct module
*mod
,
1239 const struct file_operations
*id
,
1240 const struct file_operations
*enable
,
1241 const struct file_operations
*filter
,
1242 const struct file_operations
*format
)
1244 struct dentry
*d_events
;
1247 ret
= event_init(call
);
1251 d_events
= event_trace_events_dir();
1255 ret
= event_create_dir(call
, d_events
, id
, enable
, filter
, format
);
1257 list_add(&call
->list
, &ftrace_events
);
1263 /* Add an additional event_call dynamically */
1264 int trace_add_event_call(struct ftrace_event_call
*call
)
1267 mutex_lock(&event_mutex
);
1268 ret
= __trace_add_event_call(call
, NULL
, &ftrace_event_id_fops
,
1269 &ftrace_enable_fops
,
1270 &ftrace_event_filter_fops
,
1271 &ftrace_event_format_fops
);
1272 mutex_unlock(&event_mutex
);
1276 static void remove_subsystem_dir(const char *name
)
1278 struct event_subsystem
*system
;
1280 if (strcmp(name
, TRACE_SYSTEM
) == 0)
1283 list_for_each_entry(system
, &event_subsystems
, list
) {
1284 if (strcmp(system
->name
, name
) == 0) {
1285 if (!--system
->nr_events
) {
1286 debugfs_remove_recursive(system
->entry
);
1287 list_del(&system
->list
);
1288 __put_system(system
);
1296 * Must be called under locking both of event_mutex and trace_event_mutex.
1298 static void __trace_remove_event_call(struct ftrace_event_call
*call
)
1301 trace_destroy_fields(call
);
1302 destroy_preds(call
);
1303 debugfs_remove_recursive(call
->dir
);
1304 remove_subsystem_dir(call
->class->system
);
1307 /* Remove an event_call */
1308 void trace_remove_event_call(struct ftrace_event_call
*call
)
1310 mutex_lock(&event_mutex
);
1311 down_write(&trace_event_mutex
);
1312 __trace_remove_event_call(call
);
1313 up_write(&trace_event_mutex
);
1314 mutex_unlock(&event_mutex
);
1317 #define for_each_event(event, start, end) \
1318 for (event = start; \
1319 (unsigned long)event < (unsigned long)end; \
1322 #ifdef CONFIG_MODULES
1324 static LIST_HEAD(ftrace_module_file_list
);
1327 * Modules must own their file_operations to keep up with
1328 * reference counting.
1330 struct ftrace_module_file_ops
{
1331 struct list_head list
;
1333 struct file_operations id
;
1334 struct file_operations enable
;
1335 struct file_operations format
;
1336 struct file_operations filter
;
1339 static struct ftrace_module_file_ops
*
1340 trace_create_file_ops(struct module
*mod
)
1342 struct ftrace_module_file_ops
*file_ops
;
1345 * This is a bit of a PITA. To allow for correct reference
1346 * counting, modules must "own" their file_operations.
1347 * To do this, we allocate the file operations that will be
1348 * used in the event directory.
1351 file_ops
= kmalloc(sizeof(*file_ops
), GFP_KERNEL
);
1355 file_ops
->mod
= mod
;
1357 file_ops
->id
= ftrace_event_id_fops
;
1358 file_ops
->id
.owner
= mod
;
1360 file_ops
->enable
= ftrace_enable_fops
;
1361 file_ops
->enable
.owner
= mod
;
1363 file_ops
->filter
= ftrace_event_filter_fops
;
1364 file_ops
->filter
.owner
= mod
;
1366 file_ops
->format
= ftrace_event_format_fops
;
1367 file_ops
->format
.owner
= mod
;
1369 list_add(&file_ops
->list
, &ftrace_module_file_list
);
1374 static void trace_module_add_events(struct module
*mod
)
1376 struct ftrace_module_file_ops
*file_ops
= NULL
;
1377 struct ftrace_event_call
**call
, **start
, **end
;
1379 start
= mod
->trace_events
;
1380 end
= mod
->trace_events
+ mod
->num_trace_events
;
1385 file_ops
= trace_create_file_ops(mod
);
1389 for_each_event(call
, start
, end
) {
1390 __trace_add_event_call(*call
, mod
,
1391 &file_ops
->id
, &file_ops
->enable
,
1392 &file_ops
->filter
, &file_ops
->format
);
1396 static void trace_module_remove_events(struct module
*mod
)
1398 struct ftrace_module_file_ops
*file_ops
;
1399 struct ftrace_event_call
*call
, *p
;
1402 down_write(&trace_event_mutex
);
1403 list_for_each_entry_safe(call
, p
, &ftrace_events
, list
) {
1404 if (call
->mod
== mod
) {
1406 __trace_remove_event_call(call
);
1410 /* Now free the file_operations */
1411 list_for_each_entry(file_ops
, &ftrace_module_file_list
, list
) {
1412 if (file_ops
->mod
== mod
)
1415 if (&file_ops
->list
!= &ftrace_module_file_list
) {
1416 list_del(&file_ops
->list
);
1421 * It is safest to reset the ring buffer if the module being unloaded
1422 * registered any events.
1425 tracing_reset_current_online_cpus();
1426 up_write(&trace_event_mutex
);
1429 static int trace_module_notify(struct notifier_block
*self
,
1430 unsigned long val
, void *data
)
1432 struct module
*mod
= data
;
1434 mutex_lock(&event_mutex
);
1436 case MODULE_STATE_COMING
:
1437 trace_module_add_events(mod
);
1439 case MODULE_STATE_GOING
:
1440 trace_module_remove_events(mod
);
1443 mutex_unlock(&event_mutex
);
1448 static int trace_module_notify(struct notifier_block
*self
,
1449 unsigned long val
, void *data
)
1453 #endif /* CONFIG_MODULES */
1455 static struct notifier_block trace_module_nb
= {
1456 .notifier_call
= trace_module_notify
,
1460 extern struct ftrace_event_call
*__start_ftrace_events
[];
1461 extern struct ftrace_event_call
*__stop_ftrace_events
[];
1463 static char bootup_event_buf
[COMMAND_LINE_SIZE
] __initdata
;
1465 static __init
int setup_trace_event(char *str
)
1467 strlcpy(bootup_event_buf
, str
, COMMAND_LINE_SIZE
);
1468 ring_buffer_expanded
= 1;
1469 tracing_selftest_disabled
= 1;
1473 __setup("trace_event=", setup_trace_event
);
1475 static __init
int event_trace_enable(void)
1477 struct ftrace_event_call
**iter
, *call
;
1478 char *buf
= bootup_event_buf
;
1482 for_each_event(iter
, __start_ftrace_events
, __stop_ftrace_events
) {
1485 ret
= event_init(call
);
1487 list_add(&call
->list
, &ftrace_events
);
1491 token
= strsep(&buf
, ",");
1498 ret
= ftrace_set_clr_event(token
, 1);
1500 pr_warn("Failed to enable trace event: %s\n", token
);
1503 trace_printk_start_comm();
1508 static __init
int event_trace_init(void)
1510 struct ftrace_event_call
*call
;
1511 struct dentry
*d_tracer
;
1512 struct dentry
*entry
;
1513 struct dentry
*d_events
;
1516 d_tracer
= tracing_init_dentry();
1520 entry
= debugfs_create_file("available_events", 0444, d_tracer
,
1521 NULL
, &ftrace_avail_fops
);
1523 pr_warning("Could not create debugfs "
1524 "'available_events' entry\n");
1526 entry
= debugfs_create_file("set_event", 0644, d_tracer
,
1527 NULL
, &ftrace_set_event_fops
);
1529 pr_warning("Could not create debugfs "
1530 "'set_event' entry\n");
1532 d_events
= event_trace_events_dir();
1536 /* ring buffer internal formats */
1537 trace_create_file("header_page", 0444, d_events
,
1538 ring_buffer_print_page_header
,
1539 &ftrace_show_header_fops
);
1541 trace_create_file("header_event", 0444, d_events
,
1542 ring_buffer_print_entry_header
,
1543 &ftrace_show_header_fops
);
1545 trace_create_file("enable", 0644, d_events
,
1546 NULL
, &ftrace_system_enable_fops
);
1548 if (trace_define_common_fields())
1549 pr_warning("tracing: Failed to allocate common fields");
1552 * Early initialization already enabled ftrace event.
1553 * Now it's only necessary to create the event directory.
1555 list_for_each_entry(call
, &ftrace_events
, list
) {
1557 ret
= event_create_dir(call
, d_events
,
1558 &ftrace_event_id_fops
,
1559 &ftrace_enable_fops
,
1560 &ftrace_event_filter_fops
,
1561 &ftrace_event_format_fops
);
1566 ret
= register_module_notifier(&trace_module_nb
);
1568 pr_warning("Failed to register trace events module notifier\n");
1572 core_initcall(event_trace_enable
);
1573 fs_initcall(event_trace_init
);
1575 #ifdef CONFIG_FTRACE_STARTUP_TEST
1577 static DEFINE_SPINLOCK(test_spinlock
);
1578 static DEFINE_SPINLOCK(test_spinlock_irq
);
1579 static DEFINE_MUTEX(test_mutex
);
1581 static __init
void test_work(struct work_struct
*dummy
)
1583 spin_lock(&test_spinlock
);
1584 spin_lock_irq(&test_spinlock_irq
);
1586 spin_unlock_irq(&test_spinlock_irq
);
1587 spin_unlock(&test_spinlock
);
1589 mutex_lock(&test_mutex
);
1591 mutex_unlock(&test_mutex
);
1594 static __init
int event_test_thread(void *unused
)
1598 test_malloc
= kmalloc(1234, GFP_KERNEL
);
1600 pr_info("failed to kmalloc\n");
1602 schedule_on_each_cpu(test_work
);
1606 set_current_state(TASK_INTERRUPTIBLE
);
1607 while (!kthread_should_stop())
1614 * Do various things that may trigger events.
1616 static __init
void event_test_stuff(void)
1618 struct task_struct
*test_thread
;
1620 test_thread
= kthread_run(event_test_thread
, NULL
, "test-events");
1622 kthread_stop(test_thread
);
1626 * For every trace event defined, we will test each trace point separately,
1627 * and then by groups, and finally all trace points.
1629 static __init
void event_trace_self_tests(void)
1631 struct ftrace_event_call
*call
;
1632 struct event_subsystem
*system
;
1635 pr_info("Running tests on trace events:\n");
1637 list_for_each_entry(call
, &ftrace_events
, list
) {
1639 /* Only test those that have a probe */
1640 if (!call
->class || !call
->class->probe
)
1644 * Testing syscall events here is pretty useless, but
1645 * we still do it if configured. But this is time consuming.
1646 * What we really need is a user thread to perform the
1647 * syscalls as we test.
1649 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1650 if (call
->class->system
&&
1651 strcmp(call
->class->system
, "syscalls") == 0)
1655 pr_info("Testing event %s: ", call
->name
);
1658 * If an event is already enabled, someone is using
1659 * it and the self test should not be on.
1661 if (call
->flags
& TRACE_EVENT_FL_ENABLED
) {
1662 pr_warning("Enabled event during self test!\n");
1667 ftrace_event_enable_disable(call
, 1);
1669 ftrace_event_enable_disable(call
, 0);
1674 /* Now test at the sub system level */
1676 pr_info("Running tests on trace event systems:\n");
1678 list_for_each_entry(system
, &event_subsystems
, list
) {
1680 /* the ftrace system is special, skip it */
1681 if (strcmp(system
->name
, "ftrace") == 0)
1684 pr_info("Testing event system %s: ", system
->name
);
1686 ret
= __ftrace_set_clr_event(NULL
, system
->name
, NULL
, 1);
1687 if (WARN_ON_ONCE(ret
)) {
1688 pr_warning("error enabling system %s\n",
1695 ret
= __ftrace_set_clr_event(NULL
, system
->name
, NULL
, 0);
1696 if (WARN_ON_ONCE(ret
)) {
1697 pr_warning("error disabling system %s\n",
1705 /* Test with all events enabled */
1707 pr_info("Running tests on all trace events:\n");
1708 pr_info("Testing all events: ");
1710 ret
= __ftrace_set_clr_event(NULL
, NULL
, NULL
, 1);
1711 if (WARN_ON_ONCE(ret
)) {
1712 pr_warning("error enabling all events\n");
1719 ret
= __ftrace_set_clr_event(NULL
, NULL
, NULL
, 0);
1720 if (WARN_ON_ONCE(ret
)) {
1721 pr_warning("error disabling all events\n");
1728 #ifdef CONFIG_FUNCTION_TRACER
1730 static DEFINE_PER_CPU(atomic_t
, ftrace_test_event_disable
);
1733 function_test_events_call(unsigned long ip
, unsigned long parent_ip
,
1734 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
1736 struct ring_buffer_event
*event
;
1737 struct ring_buffer
*buffer
;
1738 struct ftrace_entry
*entry
;
1739 unsigned long flags
;
1744 pc
= preempt_count();
1745 preempt_disable_notrace();
1746 cpu
= raw_smp_processor_id();
1747 disabled
= atomic_inc_return(&per_cpu(ftrace_test_event_disable
, cpu
));
1752 local_save_flags(flags
);
1754 event
= trace_current_buffer_lock_reserve(&buffer
,
1755 TRACE_FN
, sizeof(*entry
),
1759 entry
= ring_buffer_event_data(event
);
1761 entry
->parent_ip
= parent_ip
;
1763 trace_buffer_unlock_commit(buffer
, event
, flags
, pc
);
1766 atomic_dec(&per_cpu(ftrace_test_event_disable
, cpu
));
1767 preempt_enable_notrace();
1770 static struct ftrace_ops trace_ops __initdata
=
1772 .func
= function_test_events_call
,
1773 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
,
1776 static __init
void event_trace_self_test_with_function(void)
1779 ret
= register_ftrace_function(&trace_ops
);
1780 if (WARN_ON(ret
< 0)) {
1781 pr_info("Failed to enable function tracer for event tests\n");
1784 pr_info("Running tests again, along with the function tracer\n");
1785 event_trace_self_tests();
1786 unregister_ftrace_function(&trace_ops
);
1789 static __init
void event_trace_self_test_with_function(void)
1794 static __init
int event_trace_self_tests_init(void)
1796 if (!tracing_selftest_disabled
) {
1797 event_trace_self_tests();
1798 event_trace_self_test_with_function();
1804 late_initcall(event_trace_self_tests_init
);