4 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
6 * - Added format output of fields of the trace point.
7 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
11 #include <linux/workqueue.h>
12 #include <linux/spinlock.h>
13 #include <linux/kthread.h>
14 #include <linux/debugfs.h>
15 #include <linux/uaccess.h>
16 #include <linux/module.h>
17 #include <linux/ctype.h>
18 #include <linux/slab.h>
19 #include <linux/delay.h>
21 #include <asm/setup.h>
23 #include "trace_output.h"
26 #define TRACE_SYSTEM "TRACE_SYSTEM"
28 DEFINE_MUTEX(event_mutex
);
30 LIST_HEAD(ftrace_events
);
31 LIST_HEAD(ftrace_common_fields
);
34 trace_get_fields(struct ftrace_event_call
*event_call
)
36 if (!event_call
->class->get_fields
)
37 return &event_call
->class->fields
;
38 return event_call
->class->get_fields(event_call
);
41 static int __trace_define_field(struct list_head
*head
, const char *type
,
42 const char *name
, int offset
, int size
,
43 int is_signed
, int filter_type
)
45 struct ftrace_event_field
*field
;
47 field
= kzalloc(sizeof(*field
), GFP_KERNEL
);
51 field
->name
= kstrdup(name
, GFP_KERNEL
);
55 field
->type
= kstrdup(type
, GFP_KERNEL
);
59 if (filter_type
== FILTER_OTHER
)
60 field
->filter_type
= filter_assign_type(type
);
62 field
->filter_type
= filter_type
;
64 field
->offset
= offset
;
66 field
->is_signed
= is_signed
;
68 list_add(&field
->link
, head
);
80 int trace_define_field(struct ftrace_event_call
*call
, const char *type
,
81 const char *name
, int offset
, int size
, int is_signed
,
84 struct list_head
*head
;
86 if (WARN_ON(!call
->class))
89 head
= trace_get_fields(call
);
90 return __trace_define_field(head
, type
, name
, offset
, size
,
91 is_signed
, filter_type
);
93 EXPORT_SYMBOL_GPL(trace_define_field
);
95 #define __common_field(type, item) \
96 ret = __trace_define_field(&ftrace_common_fields, #type, \
98 offsetof(typeof(ent), item), \
100 is_signed_type(type), FILTER_OTHER); \
104 static int trace_define_common_fields(void)
107 struct trace_entry ent
;
109 __common_field(unsigned short, type
);
110 __common_field(unsigned char, flags
);
111 __common_field(unsigned char, preempt_count
);
112 __common_field(int, pid
);
113 __common_field(int, lock_depth
);
118 void trace_destroy_fields(struct ftrace_event_call
*call
)
120 struct ftrace_event_field
*field
, *next
;
121 struct list_head
*head
;
123 head
= trace_get_fields(call
);
124 list_for_each_entry_safe(field
, next
, head
, link
) {
125 list_del(&field
->link
);
132 int trace_event_raw_init(struct ftrace_event_call
*call
)
136 id
= register_ftrace_event(&call
->event
);
142 EXPORT_SYMBOL_GPL(trace_event_raw_init
);
144 int ftrace_event_reg(struct ftrace_event_call
*call
, enum trace_reg type
)
147 case TRACE_REG_REGISTER
:
148 return tracepoint_probe_register(call
->name
,
151 case TRACE_REG_UNREGISTER
:
152 tracepoint_probe_unregister(call
->name
,
157 #ifdef CONFIG_PERF_EVENTS
158 case TRACE_REG_PERF_REGISTER
:
159 return tracepoint_probe_register(call
->name
,
160 call
->class->perf_probe
,
162 case TRACE_REG_PERF_UNREGISTER
:
163 tracepoint_probe_unregister(call
->name
,
164 call
->class->perf_probe
,
171 EXPORT_SYMBOL_GPL(ftrace_event_reg
);
173 void trace_event_enable_cmd_record(bool enable
)
175 struct ftrace_event_call
*call
;
177 mutex_lock(&event_mutex
);
178 list_for_each_entry(call
, &ftrace_events
, list
) {
179 if (!(call
->flags
& TRACE_EVENT_FL_ENABLED
))
183 tracing_start_cmdline_record();
184 call
->flags
|= TRACE_EVENT_FL_RECORDED_CMD
;
186 tracing_stop_cmdline_record();
187 call
->flags
&= ~TRACE_EVENT_FL_RECORDED_CMD
;
190 mutex_unlock(&event_mutex
);
193 static int ftrace_event_enable_disable(struct ftrace_event_call
*call
,
200 if (call
->flags
& TRACE_EVENT_FL_ENABLED
) {
201 call
->flags
&= ~TRACE_EVENT_FL_ENABLED
;
202 if (call
->flags
& TRACE_EVENT_FL_RECORDED_CMD
) {
203 tracing_stop_cmdline_record();
204 call
->flags
&= ~TRACE_EVENT_FL_RECORDED_CMD
;
206 call
->class->reg(call
, TRACE_REG_UNREGISTER
);
210 if (!(call
->flags
& TRACE_EVENT_FL_ENABLED
)) {
211 if (trace_flags
& TRACE_ITER_RECORD_CMD
) {
212 tracing_start_cmdline_record();
213 call
->flags
|= TRACE_EVENT_FL_RECORDED_CMD
;
215 ret
= call
->class->reg(call
, TRACE_REG_REGISTER
);
217 tracing_stop_cmdline_record();
218 pr_info("event trace: Could not enable event "
222 call
->flags
|= TRACE_EVENT_FL_ENABLED
;
230 static void ftrace_clear_events(void)
232 struct ftrace_event_call
*call
;
234 mutex_lock(&event_mutex
);
235 list_for_each_entry(call
, &ftrace_events
, list
) {
236 ftrace_event_enable_disable(call
, 0);
238 mutex_unlock(&event_mutex
);
242 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
244 static int __ftrace_set_clr_event(const char *match
, const char *sub
,
245 const char *event
, int set
)
247 struct ftrace_event_call
*call
;
250 mutex_lock(&event_mutex
);
251 list_for_each_entry(call
, &ftrace_events
, list
) {
253 if (!call
->name
|| !call
->class || !call
->class->reg
)
257 strcmp(match
, call
->name
) != 0 &&
258 strcmp(match
, call
->class->system
) != 0)
261 if (sub
&& strcmp(sub
, call
->class->system
) != 0)
264 if (event
&& strcmp(event
, call
->name
) != 0)
267 ftrace_event_enable_disable(call
, set
);
271 mutex_unlock(&event_mutex
);
276 static int ftrace_set_clr_event(char *buf
, int set
)
278 char *event
= NULL
, *sub
= NULL
, *match
;
281 * The buf format can be <subsystem>:<event-name>
282 * *:<event-name> means any event by that name.
283 * :<event-name> is the same.
285 * <subsystem>:* means all events in that subsystem
286 * <subsystem>: means the same.
288 * <name> (no ':') means all events in a subsystem with
289 * the name <name> or any event that matches <name>
292 match
= strsep(&buf
, ":");
298 if (!strlen(sub
) || strcmp(sub
, "*") == 0)
300 if (!strlen(event
) || strcmp(event
, "*") == 0)
304 return __ftrace_set_clr_event(match
, sub
, event
, set
);
308 * trace_set_clr_event - enable or disable an event
309 * @system: system name to match (NULL for any system)
310 * @event: event name to match (NULL for all events, within system)
311 * @set: 1 to enable, 0 to disable
313 * This is a way for other parts of the kernel to enable or disable
316 * Returns 0 on success, -EINVAL if the parameters do not match any
319 int trace_set_clr_event(const char *system
, const char *event
, int set
)
321 return __ftrace_set_clr_event(NULL
, system
, event
, set
);
324 /* 128 should be much more than enough */
325 #define EVENT_BUF_SIZE 127
328 ftrace_event_write(struct file
*file
, const char __user
*ubuf
,
329 size_t cnt
, loff_t
*ppos
)
331 struct trace_parser parser
;
337 ret
= tracing_update_buffers();
341 if (trace_parser_get_init(&parser
, EVENT_BUF_SIZE
+ 1))
344 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
346 if (read
>= 0 && trace_parser_loaded((&parser
))) {
349 if (*parser
.buffer
== '!')
352 parser
.buffer
[parser
.idx
] = 0;
354 ret
= ftrace_set_clr_event(parser
.buffer
+ !set
, set
);
362 trace_parser_put(&parser
);
368 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
370 struct ftrace_event_call
*call
= v
;
374 list_for_each_entry_continue(call
, &ftrace_events
, list
) {
376 * The ftrace subsystem is for showing formats only.
377 * They can not be enabled or disabled via the event files.
379 if (call
->class && call
->class->reg
)
386 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
388 struct ftrace_event_call
*call
;
391 mutex_lock(&event_mutex
);
393 call
= list_entry(&ftrace_events
, struct ftrace_event_call
, list
);
394 for (l
= 0; l
<= *pos
; ) {
395 call
= t_next(m
, call
, &l
);
403 s_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
405 struct ftrace_event_call
*call
= v
;
409 list_for_each_entry_continue(call
, &ftrace_events
, list
) {
410 if (call
->flags
& TRACE_EVENT_FL_ENABLED
)
417 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
419 struct ftrace_event_call
*call
;
422 mutex_lock(&event_mutex
);
424 call
= list_entry(&ftrace_events
, struct ftrace_event_call
, list
);
425 for (l
= 0; l
<= *pos
; ) {
426 call
= s_next(m
, call
, &l
);
433 static int t_show(struct seq_file
*m
, void *v
)
435 struct ftrace_event_call
*call
= v
;
437 if (strcmp(call
->class->system
, TRACE_SYSTEM
) != 0)
438 seq_printf(m
, "%s:", call
->class->system
);
439 seq_printf(m
, "%s\n", call
->name
);
444 static void t_stop(struct seq_file
*m
, void *p
)
446 mutex_unlock(&event_mutex
);
450 ftrace_event_seq_open(struct inode
*inode
, struct file
*file
)
452 const struct seq_operations
*seq_ops
;
454 if ((file
->f_mode
& FMODE_WRITE
) &&
455 (file
->f_flags
& O_TRUNC
))
456 ftrace_clear_events();
458 seq_ops
= inode
->i_private
;
459 return seq_open(file
, seq_ops
);
463 event_enable_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
466 struct ftrace_event_call
*call
= filp
->private_data
;
469 if (call
->flags
& TRACE_EVENT_FL_ENABLED
)
474 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, 2);
478 event_enable_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
481 struct ftrace_event_call
*call
= filp
->private_data
;
486 if (cnt
>= sizeof(buf
))
489 if (copy_from_user(&buf
, ubuf
, cnt
))
494 ret
= strict_strtoul(buf
, 10, &val
);
498 ret
= tracing_update_buffers();
505 mutex_lock(&event_mutex
);
506 ret
= ftrace_event_enable_disable(call
, val
);
507 mutex_unlock(&event_mutex
);
516 return ret
? ret
: cnt
;
520 system_enable_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
523 const char set_to_char
[4] = { '?', '0', '1', 'X' };
524 const char *system
= filp
->private_data
;
525 struct ftrace_event_call
*call
;
530 mutex_lock(&event_mutex
);
531 list_for_each_entry(call
, &ftrace_events
, list
) {
532 if (!call
->name
|| !call
->class || !call
->class->reg
)
535 if (system
&& strcmp(call
->class->system
, system
) != 0)
539 * We need to find out if all the events are set
540 * or if all events or cleared, or if we have
543 set
|= (1 << !!(call
->flags
& TRACE_EVENT_FL_ENABLED
));
546 * If we have a mixture, no need to look further.
551 mutex_unlock(&event_mutex
);
553 buf
[0] = set_to_char
[set
];
556 ret
= simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, 2);
562 system_enable_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
565 const char *system
= filp
->private_data
;
570 if (cnt
>= sizeof(buf
))
573 if (copy_from_user(&buf
, ubuf
, cnt
))
578 ret
= strict_strtoul(buf
, 10, &val
);
582 ret
= tracing_update_buffers();
586 if (val
!= 0 && val
!= 1)
589 ret
= __ftrace_set_clr_event(NULL
, system
, NULL
, val
);
601 static void print_event_fields(struct trace_seq
*s
, struct list_head
*head
)
603 struct ftrace_event_field
*field
;
605 list_for_each_entry_reverse(field
, head
, link
) {
607 * Smartly shows the array type(except dynamic array).
610 * If TYPE := TYPE[LEN], it is shown:
611 * field:TYPE VAR[LEN]
613 const char *array_descriptor
= strchr(field
->type
, '[');
615 if (!strncmp(field
->type
, "__data_loc", 10))
616 array_descriptor
= NULL
;
618 if (!array_descriptor
) {
619 trace_seq_printf(s
, "\tfield:%s %s;\toffset:%u;"
620 "\tsize:%u;\tsigned:%d;\n",
621 field
->type
, field
->name
, field
->offset
,
622 field
->size
, !!field
->is_signed
);
624 trace_seq_printf(s
, "\tfield:%.*s %s%s;\toffset:%u;"
625 "\tsize:%u;\tsigned:%d;\n",
626 (int)(array_descriptor
- field
->type
),
627 field
->type
, field
->name
,
628 array_descriptor
, field
->offset
,
629 field
->size
, !!field
->is_signed
);
635 event_format_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
638 struct ftrace_event_call
*call
= filp
->private_data
;
639 struct list_head
*head
;
647 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
653 trace_seq_printf(s
, "name: %s\n", call
->name
);
654 trace_seq_printf(s
, "ID: %d\n", call
->event
.type
);
655 trace_seq_printf(s
, "format:\n");
657 /* print common fields */
658 print_event_fields(s
, &ftrace_common_fields
);
660 trace_seq_putc(s
, '\n');
662 /* print event specific fields */
663 head
= trace_get_fields(call
);
664 print_event_fields(s
, head
);
666 r
= trace_seq_printf(s
, "\nprint fmt: %s\n", call
->print_fmt
);
670 * ug! The format output is bigger than a PAGE!!
672 buf
= "FORMAT TOO BIG\n";
673 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
,
678 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
,
686 event_id_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
, loff_t
*ppos
)
688 struct ftrace_event_call
*call
= filp
->private_data
;
695 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
700 trace_seq_printf(s
, "%d\n", call
->event
.type
);
702 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
,
709 event_filter_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
712 struct ftrace_event_call
*call
= filp
->private_data
;
719 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
725 print_event_filter(call
, s
);
726 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, s
->buffer
, s
->len
);
734 event_filter_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
737 struct ftrace_event_call
*call
= filp
->private_data
;
741 if (cnt
>= PAGE_SIZE
)
744 buf
= (char *)__get_free_page(GFP_TEMPORARY
);
748 if (copy_from_user(buf
, ubuf
, cnt
)) {
749 free_page((unsigned long) buf
);
754 err
= apply_event_filter(call
, buf
);
755 free_page((unsigned long) buf
);
765 subsystem_filter_read(struct file
*filp
, char __user
*ubuf
, size_t cnt
,
768 struct event_subsystem
*system
= filp
->private_data
;
775 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
781 print_subsystem_event_filter(system
, s
);
782 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, s
->buffer
, s
->len
);
790 subsystem_filter_write(struct file
*filp
, const char __user
*ubuf
, size_t cnt
,
793 struct event_subsystem
*system
= filp
->private_data
;
797 if (cnt
>= PAGE_SIZE
)
800 buf
= (char *)__get_free_page(GFP_TEMPORARY
);
804 if (copy_from_user(buf
, ubuf
, cnt
)) {
805 free_page((unsigned long) buf
);
810 err
= apply_subsystem_event_filter(system
, buf
);
811 free_page((unsigned long) buf
);
821 show_header(struct file
*filp
, char __user
*ubuf
, size_t cnt
, loff_t
*ppos
)
823 int (*func
)(struct trace_seq
*s
) = filp
->private_data
;
830 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
837 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, s
->buffer
, s
->len
);
844 static const struct seq_operations show_event_seq_ops
= {
851 static const struct seq_operations show_set_event_seq_ops
= {
858 static const struct file_operations ftrace_avail_fops
= {
859 .open
= ftrace_event_seq_open
,
862 .release
= seq_release
,
865 static const struct file_operations ftrace_set_event_fops
= {
866 .open
= ftrace_event_seq_open
,
868 .write
= ftrace_event_write
,
870 .release
= seq_release
,
873 static const struct file_operations ftrace_enable_fops
= {
874 .open
= tracing_open_generic
,
875 .read
= event_enable_read
,
876 .write
= event_enable_write
,
879 static const struct file_operations ftrace_event_format_fops
= {
880 .open
= tracing_open_generic
,
881 .read
= event_format_read
,
884 static const struct file_operations ftrace_event_id_fops
= {
885 .open
= tracing_open_generic
,
886 .read
= event_id_read
,
889 static const struct file_operations ftrace_event_filter_fops
= {
890 .open
= tracing_open_generic
,
891 .read
= event_filter_read
,
892 .write
= event_filter_write
,
895 static const struct file_operations ftrace_subsystem_filter_fops
= {
896 .open
= tracing_open_generic
,
897 .read
= subsystem_filter_read
,
898 .write
= subsystem_filter_write
,
901 static const struct file_operations ftrace_system_enable_fops
= {
902 .open
= tracing_open_generic
,
903 .read
= system_enable_read
,
904 .write
= system_enable_write
,
907 static const struct file_operations ftrace_show_header_fops
= {
908 .open
= tracing_open_generic
,
912 static struct dentry
*event_trace_events_dir(void)
914 static struct dentry
*d_tracer
;
915 static struct dentry
*d_events
;
920 d_tracer
= tracing_init_dentry();
924 d_events
= debugfs_create_dir("events", d_tracer
);
926 pr_warning("Could not create debugfs "
927 "'events' directory\n");
932 static LIST_HEAD(event_subsystems
);
934 static struct dentry
*
935 event_subsystem_dir(const char *name
, struct dentry
*d_events
)
937 struct event_subsystem
*system
;
938 struct dentry
*entry
;
940 /* First see if we did not already create this dir */
941 list_for_each_entry(system
, &event_subsystems
, list
) {
942 if (strcmp(system
->name
, name
) == 0) {
944 return system
->entry
;
948 /* need to create new entry */
949 system
= kmalloc(sizeof(*system
), GFP_KERNEL
);
951 pr_warning("No memory to create event subsystem %s\n",
956 system
->entry
= debugfs_create_dir(name
, d_events
);
957 if (!system
->entry
) {
958 pr_warning("Could not create event subsystem %s\n",
964 system
->nr_events
= 1;
965 system
->name
= kstrdup(name
, GFP_KERNEL
);
967 debugfs_remove(system
->entry
);
972 list_add(&system
->list
, &event_subsystems
);
974 system
->filter
= NULL
;
976 system
->filter
= kzalloc(sizeof(struct event_filter
), GFP_KERNEL
);
977 if (!system
->filter
) {
978 pr_warning("Could not allocate filter for subsystem "
980 return system
->entry
;
983 entry
= debugfs_create_file("filter", 0644, system
->entry
, system
,
984 &ftrace_subsystem_filter_fops
);
986 kfree(system
->filter
);
987 system
->filter
= NULL
;
988 pr_warning("Could not create debugfs "
989 "'%s/filter' entry\n", name
);
992 trace_create_file("enable", 0644, system
->entry
,
993 (void *)system
->name
,
994 &ftrace_system_enable_fops
);
996 return system
->entry
;
1000 event_create_dir(struct ftrace_event_call
*call
, struct dentry
*d_events
,
1001 const struct file_operations
*id
,
1002 const struct file_operations
*enable
,
1003 const struct file_operations
*filter
,
1004 const struct file_operations
*format
)
1006 struct list_head
*head
;
1010 * If the trace point header did not define TRACE_SYSTEM
1011 * then the system would be called "TRACE_SYSTEM".
1013 if (strcmp(call
->class->system
, TRACE_SYSTEM
) != 0)
1014 d_events
= event_subsystem_dir(call
->class->system
, d_events
);
1016 call
->dir
= debugfs_create_dir(call
->name
, d_events
);
1018 pr_warning("Could not create debugfs "
1019 "'%s' directory\n", call
->name
);
1023 if (call
->class->reg
)
1024 trace_create_file("enable", 0644, call
->dir
, call
,
1027 #ifdef CONFIG_PERF_EVENTS
1028 if (call
->event
.type
&& call
->class->reg
)
1029 trace_create_file("id", 0444, call
->dir
, call
,
1034 * Other events may have the same class. Only update
1035 * the fields if they are not already defined.
1037 head
= trace_get_fields(call
);
1038 if (list_empty(head
)) {
1039 ret
= call
->class->define_fields(call
);
1041 pr_warning("Could not initialize trace point"
1042 " events/%s\n", call
->name
);
1046 trace_create_file("filter", 0644, call
->dir
, call
,
1049 trace_create_file("format", 0444, call
->dir
, call
,
1056 __trace_add_event_call(struct ftrace_event_call
*call
, struct module
*mod
,
1057 const struct file_operations
*id
,
1058 const struct file_operations
*enable
,
1059 const struct file_operations
*filter
,
1060 const struct file_operations
*format
)
1062 struct dentry
*d_events
;
1065 /* The linker may leave blanks */
1069 if (call
->class->raw_init
) {
1070 ret
= call
->class->raw_init(call
);
1073 pr_warning("Could not initialize trace events/%s\n",
1079 d_events
= event_trace_events_dir();
1083 ret
= event_create_dir(call
, d_events
, id
, enable
, filter
, format
);
1085 list_add(&call
->list
, &ftrace_events
);
1091 /* Add an additional event_call dynamically */
1092 int trace_add_event_call(struct ftrace_event_call
*call
)
1095 mutex_lock(&event_mutex
);
1096 ret
= __trace_add_event_call(call
, NULL
, &ftrace_event_id_fops
,
1097 &ftrace_enable_fops
,
1098 &ftrace_event_filter_fops
,
1099 &ftrace_event_format_fops
);
1100 mutex_unlock(&event_mutex
);
1104 static void remove_subsystem_dir(const char *name
)
1106 struct event_subsystem
*system
;
1108 if (strcmp(name
, TRACE_SYSTEM
) == 0)
1111 list_for_each_entry(system
, &event_subsystems
, list
) {
1112 if (strcmp(system
->name
, name
) == 0) {
1113 if (!--system
->nr_events
) {
1114 struct event_filter
*filter
= system
->filter
;
1116 debugfs_remove_recursive(system
->entry
);
1117 list_del(&system
->list
);
1119 kfree(filter
->filter_string
);
1122 kfree(system
->name
);
1131 * Must be called under locking both of event_mutex and trace_event_mutex.
1133 static void __trace_remove_event_call(struct ftrace_event_call
*call
)
1135 ftrace_event_enable_disable(call
, 0);
1136 if (call
->event
.funcs
)
1137 __unregister_ftrace_event(&call
->event
);
1138 debugfs_remove_recursive(call
->dir
);
1139 list_del(&call
->list
);
1140 trace_destroy_fields(call
);
1141 destroy_preds(call
);
1142 remove_subsystem_dir(call
->class->system
);
1145 /* Remove an event_call */
1146 void trace_remove_event_call(struct ftrace_event_call
*call
)
1148 mutex_lock(&event_mutex
);
1149 down_write(&trace_event_mutex
);
1150 __trace_remove_event_call(call
);
1151 up_write(&trace_event_mutex
);
1152 mutex_unlock(&event_mutex
);
1155 #define for_each_event(event, start, end) \
1156 for (event = start; \
1157 (unsigned long)event < (unsigned long)end; \
1160 #ifdef CONFIG_MODULES
1162 static LIST_HEAD(ftrace_module_file_list
);
1165 * Modules must own their file_operations to keep up with
1166 * reference counting.
1168 struct ftrace_module_file_ops
{
1169 struct list_head list
;
1171 struct file_operations id
;
1172 struct file_operations enable
;
1173 struct file_operations format
;
1174 struct file_operations filter
;
1177 static struct ftrace_module_file_ops
*
1178 trace_create_file_ops(struct module
*mod
)
1180 struct ftrace_module_file_ops
*file_ops
;
1183 * This is a bit of a PITA. To allow for correct reference
1184 * counting, modules must "own" their file_operations.
1185 * To do this, we allocate the file operations that will be
1186 * used in the event directory.
1189 file_ops
= kmalloc(sizeof(*file_ops
), GFP_KERNEL
);
1193 file_ops
->mod
= mod
;
1195 file_ops
->id
= ftrace_event_id_fops
;
1196 file_ops
->id
.owner
= mod
;
1198 file_ops
->enable
= ftrace_enable_fops
;
1199 file_ops
->enable
.owner
= mod
;
1201 file_ops
->filter
= ftrace_event_filter_fops
;
1202 file_ops
->filter
.owner
= mod
;
1204 file_ops
->format
= ftrace_event_format_fops
;
1205 file_ops
->format
.owner
= mod
;
1207 list_add(&file_ops
->list
, &ftrace_module_file_list
);
1212 static void trace_module_add_events(struct module
*mod
)
1214 struct ftrace_module_file_ops
*file_ops
= NULL
;
1215 struct ftrace_event_call
*call
, *start
, *end
;
1217 start
= mod
->trace_events
;
1218 end
= mod
->trace_events
+ mod
->num_trace_events
;
1223 file_ops
= trace_create_file_ops(mod
);
1227 for_each_event(call
, start
, end
) {
1228 __trace_add_event_call(call
, mod
,
1229 &file_ops
->id
, &file_ops
->enable
,
1230 &file_ops
->filter
, &file_ops
->format
);
1234 static void trace_module_remove_events(struct module
*mod
)
1236 struct ftrace_module_file_ops
*file_ops
;
1237 struct ftrace_event_call
*call
, *p
;
1240 down_write(&trace_event_mutex
);
1241 list_for_each_entry_safe(call
, p
, &ftrace_events
, list
) {
1242 if (call
->mod
== mod
) {
1244 __trace_remove_event_call(call
);
1248 /* Now free the file_operations */
1249 list_for_each_entry(file_ops
, &ftrace_module_file_list
, list
) {
1250 if (file_ops
->mod
== mod
)
1253 if (&file_ops
->list
!= &ftrace_module_file_list
) {
1254 list_del(&file_ops
->list
);
1259 * It is safest to reset the ring buffer if the module being unloaded
1260 * registered any events.
1263 tracing_reset_current_online_cpus();
1264 up_write(&trace_event_mutex
);
1267 static int trace_module_notify(struct notifier_block
*self
,
1268 unsigned long val
, void *data
)
1270 struct module
*mod
= data
;
1272 mutex_lock(&event_mutex
);
1274 case MODULE_STATE_COMING
:
1275 trace_module_add_events(mod
);
1277 case MODULE_STATE_GOING
:
1278 trace_module_remove_events(mod
);
1281 mutex_unlock(&event_mutex
);
1286 static int trace_module_notify(struct notifier_block
*self
,
1287 unsigned long val
, void *data
)
1291 #endif /* CONFIG_MODULES */
1293 static struct notifier_block trace_module_nb
= {
1294 .notifier_call
= trace_module_notify
,
1298 extern struct ftrace_event_call __start_ftrace_events
[];
1299 extern struct ftrace_event_call __stop_ftrace_events
[];
1301 static char bootup_event_buf
[COMMAND_LINE_SIZE
] __initdata
;
1303 static __init
int setup_trace_event(char *str
)
1305 strlcpy(bootup_event_buf
, str
, COMMAND_LINE_SIZE
);
1306 ring_buffer_expanded
= 1;
1307 tracing_selftest_disabled
= 1;
1311 __setup("trace_event=", setup_trace_event
);
1313 static __init
int event_trace_init(void)
1315 struct ftrace_event_call
*call
;
1316 struct dentry
*d_tracer
;
1317 struct dentry
*entry
;
1318 struct dentry
*d_events
;
1320 char *buf
= bootup_event_buf
;
1323 d_tracer
= tracing_init_dentry();
1327 entry
= debugfs_create_file("available_events", 0444, d_tracer
,
1328 (void *)&show_event_seq_ops
,
1329 &ftrace_avail_fops
);
1331 pr_warning("Could not create debugfs "
1332 "'available_events' entry\n");
1334 entry
= debugfs_create_file("set_event", 0644, d_tracer
,
1335 (void *)&show_set_event_seq_ops
,
1336 &ftrace_set_event_fops
);
1338 pr_warning("Could not create debugfs "
1339 "'set_event' entry\n");
1341 d_events
= event_trace_events_dir();
1345 /* ring buffer internal formats */
1346 trace_create_file("header_page", 0444, d_events
,
1347 ring_buffer_print_page_header
,
1348 &ftrace_show_header_fops
);
1350 trace_create_file("header_event", 0444, d_events
,
1351 ring_buffer_print_entry_header
,
1352 &ftrace_show_header_fops
);
1354 trace_create_file("enable", 0644, d_events
,
1355 NULL
, &ftrace_system_enable_fops
);
1357 if (trace_define_common_fields())
1358 pr_warning("tracing: Failed to allocate common fields");
1360 for_each_event(call
, __start_ftrace_events
, __stop_ftrace_events
) {
1361 __trace_add_event_call(call
, NULL
, &ftrace_event_id_fops
,
1362 &ftrace_enable_fops
,
1363 &ftrace_event_filter_fops
,
1364 &ftrace_event_format_fops
);
1368 token
= strsep(&buf
, ",");
1375 ret
= ftrace_set_clr_event(token
, 1);
1377 pr_warning("Failed to enable trace event: %s\n", token
);
1380 ret
= register_module_notifier(&trace_module_nb
);
1382 pr_warning("Failed to register trace events module notifier\n");
1386 fs_initcall(event_trace_init
);
1388 #ifdef CONFIG_FTRACE_STARTUP_TEST
1390 static DEFINE_SPINLOCK(test_spinlock
);
1391 static DEFINE_SPINLOCK(test_spinlock_irq
);
1392 static DEFINE_MUTEX(test_mutex
);
1394 static __init
void test_work(struct work_struct
*dummy
)
1396 spin_lock(&test_spinlock
);
1397 spin_lock_irq(&test_spinlock_irq
);
1399 spin_unlock_irq(&test_spinlock_irq
);
1400 spin_unlock(&test_spinlock
);
1402 mutex_lock(&test_mutex
);
1404 mutex_unlock(&test_mutex
);
1407 static __init
int event_test_thread(void *unused
)
1411 test_malloc
= kmalloc(1234, GFP_KERNEL
);
1413 pr_info("failed to kmalloc\n");
1415 schedule_on_each_cpu(test_work
);
1419 set_current_state(TASK_INTERRUPTIBLE
);
1420 while (!kthread_should_stop())
1427 * Do various things that may trigger events.
1429 static __init
void event_test_stuff(void)
1431 struct task_struct
*test_thread
;
1433 test_thread
= kthread_run(event_test_thread
, NULL
, "test-events");
1435 kthread_stop(test_thread
);
1439 * For every trace event defined, we will test each trace point separately,
1440 * and then by groups, and finally all trace points.
1442 static __init
void event_trace_self_tests(void)
1444 struct ftrace_event_call
*call
;
1445 struct event_subsystem
*system
;
1448 pr_info("Running tests on trace events:\n");
1450 list_for_each_entry(call
, &ftrace_events
, list
) {
1452 /* Only test those that have a probe */
1453 if (!call
->class || !call
->class->probe
)
1457 * Testing syscall events here is pretty useless, but
1458 * we still do it if configured. But this is time consuming.
1459 * What we really need is a user thread to perform the
1460 * syscalls as we test.
1462 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1463 if (call
->class->system
&&
1464 strcmp(call
->class->system
, "syscalls") == 0)
1468 pr_info("Testing event %s: ", call
->name
);
1471 * If an event is already enabled, someone is using
1472 * it and the self test should not be on.
1474 if (call
->flags
& TRACE_EVENT_FL_ENABLED
) {
1475 pr_warning("Enabled event during self test!\n");
1480 ftrace_event_enable_disable(call
, 1);
1482 ftrace_event_enable_disable(call
, 0);
1487 /* Now test at the sub system level */
1489 pr_info("Running tests on trace event systems:\n");
1491 list_for_each_entry(system
, &event_subsystems
, list
) {
1493 /* the ftrace system is special, skip it */
1494 if (strcmp(system
->name
, "ftrace") == 0)
1497 pr_info("Testing event system %s: ", system
->name
);
1499 ret
= __ftrace_set_clr_event(NULL
, system
->name
, NULL
, 1);
1500 if (WARN_ON_ONCE(ret
)) {
1501 pr_warning("error enabling system %s\n",
1508 ret
= __ftrace_set_clr_event(NULL
, system
->name
, NULL
, 0);
1509 if (WARN_ON_ONCE(ret
))
1510 pr_warning("error disabling system %s\n",
1516 /* Test with all events enabled */
1518 pr_info("Running tests on all trace events:\n");
1519 pr_info("Testing all events: ");
1521 ret
= __ftrace_set_clr_event(NULL
, NULL
, NULL
, 1);
1522 if (WARN_ON_ONCE(ret
)) {
1523 pr_warning("error enabling all events\n");
1530 ret
= __ftrace_set_clr_event(NULL
, NULL
, NULL
, 0);
1531 if (WARN_ON_ONCE(ret
)) {
1532 pr_warning("error disabling all events\n");
1539 #ifdef CONFIG_FUNCTION_TRACER
1541 static DEFINE_PER_CPU(atomic_t
, ftrace_test_event_disable
);
1544 function_test_events_call(unsigned long ip
, unsigned long parent_ip
)
1546 struct ring_buffer_event
*event
;
1547 struct ring_buffer
*buffer
;
1548 struct ftrace_entry
*entry
;
1549 unsigned long flags
;
1554 pc
= preempt_count();
1555 preempt_disable_notrace();
1556 cpu
= raw_smp_processor_id();
1557 disabled
= atomic_inc_return(&per_cpu(ftrace_test_event_disable
, cpu
));
1562 local_save_flags(flags
);
1564 event
= trace_current_buffer_lock_reserve(&buffer
,
1565 TRACE_FN
, sizeof(*entry
),
1569 entry
= ring_buffer_event_data(event
);
1571 entry
->parent_ip
= parent_ip
;
1573 trace_nowake_buffer_unlock_commit(buffer
, event
, flags
, pc
);
1576 atomic_dec(&per_cpu(ftrace_test_event_disable
, cpu
));
1577 preempt_enable_notrace();
1580 static struct ftrace_ops trace_ops __initdata
=
1582 .func
= function_test_events_call
,
1585 static __init
void event_trace_self_test_with_function(void)
1587 register_ftrace_function(&trace_ops
);
1588 pr_info("Running tests again, along with the function tracer\n");
1589 event_trace_self_tests();
1590 unregister_ftrace_function(&trace_ops
);
1593 static __init
void event_trace_self_test_with_function(void)
1598 static __init
int event_trace_self_tests_init(void)
1600 if (!tracing_selftest_disabled
) {
1601 event_trace_self_tests();
1602 event_trace_self_test_with_function();
1608 late_initcall(event_trace_self_tests_init
);