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 */
295 if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
296 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
300 * When soft_disable is set and enable is set, we want to
301 * register the tracepoint for the event, but leave the event
302 * as is. That means, if the event was already enabled, we do
303 * nothing (but set SOFT_MODE). If the event is disabled, we
304 * set SOFT_DISABLED before enabling the event tracepoint, so
305 * it still seems to be disabled.
308 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
310 if (atomic_inc_return(&file->sm_ref) > 1)
312 set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
315 if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) {
317 /* Keep the event disabled, when going to SOFT_MODE. */
319 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
321 if (trace_flags & TRACE_ITER_RECORD_CMD) {
322 tracing_start_cmdline_record();
323 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
325 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
327 tracing_stop_cmdline_record();
328 pr_info("event trace: Could not enable event "
332 set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
334 /* WAS_ENABLED gets set but never cleared. */
335 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
343 static int ftrace_event_enable_disable(struct ftrace_event_file *file,
346 return __ftrace_event_enable_disable(file, enable, 0);
349 static void ftrace_clear_events(struct trace_array *tr)
351 struct ftrace_event_file *file;
353 mutex_lock(&event_mutex);
354 list_for_each_entry(file, &tr->events, list) {
355 ftrace_event_enable_disable(file, 0);
357 mutex_unlock(&event_mutex);
360 static void __put_system(struct event_subsystem *system)
362 struct event_filter *filter = system->filter;
364 WARN_ON_ONCE(system_refcount(system) == 0);
365 if (system_refcount_dec(system))
368 list_del(&system->list);
371 kfree(filter->filter_string);
374 if (system->ref_count & SYSTEM_FL_FREE_NAME)
379 static void __get_system(struct event_subsystem *system)
381 WARN_ON_ONCE(system_refcount(system) == 0);
382 system_refcount_inc(system);
385 static void __get_system_dir(struct ftrace_subsystem_dir *dir)
387 WARN_ON_ONCE(dir->ref_count == 0);
389 __get_system(dir->subsystem);
392 static void __put_system_dir(struct ftrace_subsystem_dir *dir)
394 WARN_ON_ONCE(dir->ref_count == 0);
395 /* If the subsystem is about to be freed, the dir must be too */
396 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
398 __put_system(dir->subsystem);
399 if (!--dir->ref_count)
403 static void put_system(struct ftrace_subsystem_dir *dir)
405 mutex_lock(&event_mutex);
406 __put_system_dir(dir);
407 mutex_unlock(&event_mutex);
410 static void remove_subsystem(struct ftrace_subsystem_dir *dir)
415 if (!--dir->nr_events) {
416 debugfs_remove_recursive(dir->entry);
417 list_del(&dir->list);
418 __put_system_dir(dir);
422 static void *event_file_data(struct file *filp)
424 return ACCESS_ONCE(file_inode(filp)->i_private);
427 static void remove_event_file_dir(struct ftrace_event_file *file)
429 struct dentry *dir = file->dir;
430 struct dentry *child;
433 spin_lock(&dir->d_lock); /* probably unneeded */
434 list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
435 if (child->d_inode) /* probably unneeded */
436 child->d_inode->i_private = NULL;
438 spin_unlock(&dir->d_lock);
440 debugfs_remove_recursive(dir);
443 list_del(&file->list);
444 remove_subsystem(file->system);
445 kmem_cache_free(file_cachep, file);
449 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
452 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
453 const char *sub, const char *event, int set)
455 struct ftrace_event_file *file;
456 struct ftrace_event_call *call;
459 list_for_each_entry(file, &tr->events, list) {
461 call = file->event_call;
463 if (!call->name || !call->class || !call->class->reg)
466 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
470 strcmp(match, call->name) != 0 &&
471 strcmp(match, call->class->system) != 0)
474 if (sub && strcmp(sub, call->class->system) != 0)
477 if (event && strcmp(event, call->name) != 0)
480 ftrace_event_enable_disable(file, set);
488 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
489 const char *sub, const char *event, int set)
493 mutex_lock(&event_mutex);
494 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
495 mutex_unlock(&event_mutex);
500 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
502 char *event = NULL, *sub = NULL, *match;
505 * The buf format can be <subsystem>:<event-name>
506 * *:<event-name> means any event by that name.
507 * :<event-name> is the same.
509 * <subsystem>:* means all events in that subsystem
510 * <subsystem>: means the same.
512 * <name> (no ':') means all events in a subsystem with
513 * the name <name> or any event that matches <name>
516 match = strsep(&buf, ":");
522 if (!strlen(sub) || strcmp(sub, "*") == 0)
524 if (!strlen(event) || strcmp(event, "*") == 0)
528 return __ftrace_set_clr_event(tr, match, sub, event, set);
532 * trace_set_clr_event - enable or disable an event
533 * @system: system name to match (NULL for any system)
534 * @event: event name to match (NULL for all events, within system)
535 * @set: 1 to enable, 0 to disable
537 * This is a way for other parts of the kernel to enable or disable
540 * Returns 0 on success, -EINVAL if the parameters do not match any
543 int trace_set_clr_event(const char *system, const char *event, int set)
545 struct trace_array *tr = top_trace_array();
547 return __ftrace_set_clr_event(tr, NULL, system, event, set);
549 EXPORT_SYMBOL_GPL(trace_set_clr_event);
551 /* 128 should be much more than enough */
552 #define EVENT_BUF_SIZE 127
555 ftrace_event_write(struct file *file, const char __user *ubuf,
556 size_t cnt, loff_t *ppos)
558 struct trace_parser parser;
559 struct seq_file *m = file->private_data;
560 struct trace_array *tr = m->private;
566 ret = tracing_update_buffers();
570 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
573 read = trace_get_user(&parser, ubuf, cnt, ppos);
575 if (read >= 0 && trace_parser_loaded((&parser))) {
578 if (*parser.buffer == '!')
581 parser.buffer[parser.idx] = 0;
583 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
591 trace_parser_put(&parser);
597 t_next(struct seq_file *m, void *v, loff_t *pos)
599 struct ftrace_event_file *file = v;
600 struct ftrace_event_call *call;
601 struct trace_array *tr = m->private;
605 list_for_each_entry_continue(file, &tr->events, list) {
606 call = file->event_call;
608 * The ftrace subsystem is for showing formats only.
609 * They can not be enabled or disabled via the event files.
611 if (call->class && call->class->reg)
618 static void *t_start(struct seq_file *m, loff_t *pos)
620 struct ftrace_event_file *file;
621 struct trace_array *tr = m->private;
624 mutex_lock(&event_mutex);
626 file = list_entry(&tr->events, struct ftrace_event_file, list);
627 for (l = 0; l <= *pos; ) {
628 file = t_next(m, file, &l);
636 s_next(struct seq_file *m, void *v, loff_t *pos)
638 struct ftrace_event_file *file = v;
639 struct trace_array *tr = m->private;
643 list_for_each_entry_continue(file, &tr->events, list) {
644 if (file->flags & FTRACE_EVENT_FL_ENABLED)
651 static void *s_start(struct seq_file *m, loff_t *pos)
653 struct ftrace_event_file *file;
654 struct trace_array *tr = m->private;
657 mutex_lock(&event_mutex);
659 file = list_entry(&tr->events, struct ftrace_event_file, list);
660 for (l = 0; l <= *pos; ) {
661 file = s_next(m, file, &l);
668 static int t_show(struct seq_file *m, void *v)
670 struct ftrace_event_file *file = v;
671 struct ftrace_event_call *call = file->event_call;
673 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
674 seq_printf(m, "%s:", call->class->system);
675 seq_printf(m, "%s\n", call->name);
680 static void t_stop(struct seq_file *m, void *p)
682 mutex_unlock(&event_mutex);
686 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
689 struct ftrace_event_file *file;
693 mutex_lock(&event_mutex);
694 file = event_file_data(filp);
697 mutex_unlock(&event_mutex);
702 if (flags & FTRACE_EVENT_FL_ENABLED) {
703 if (flags & FTRACE_EVENT_FL_SOFT_DISABLED)
705 else if (flags & FTRACE_EVENT_FL_SOFT_MODE)
712 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
716 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
719 struct ftrace_event_file *file;
723 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
727 ret = tracing_update_buffers();
735 mutex_lock(&event_mutex);
736 file = event_file_data(filp);
738 ret = ftrace_event_enable_disable(file, val);
739 mutex_unlock(&event_mutex);
748 return ret ? ret : cnt;
752 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
755 const char set_to_char[4] = { '?', '0', '1', 'X' };
756 struct ftrace_subsystem_dir *dir = filp->private_data;
757 struct event_subsystem *system = dir->subsystem;
758 struct ftrace_event_call *call;
759 struct ftrace_event_file *file;
760 struct trace_array *tr = dir->tr;
765 mutex_lock(&event_mutex);
766 list_for_each_entry(file, &tr->events, list) {
767 call = file->event_call;
768 if (!call->name || !call->class || !call->class->reg)
771 if (system && strcmp(call->class->system, system->name) != 0)
775 * We need to find out if all the events are set
776 * or if all events or cleared, or if we have
779 set |= (1 << !!(file->flags & FTRACE_EVENT_FL_ENABLED));
782 * If we have a mixture, no need to look further.
787 mutex_unlock(&event_mutex);
789 buf[0] = set_to_char[set];
792 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
798 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
801 struct ftrace_subsystem_dir *dir = filp->private_data;
802 struct event_subsystem *system = dir->subsystem;
803 const char *name = NULL;
807 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
811 ret = tracing_update_buffers();
815 if (val != 0 && val != 1)
819 * Opening of "enable" adds a ref count to system,
820 * so the name is safe to use.
825 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
839 FORMAT_FIELD_SEPERATOR = 2,
843 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
845 struct ftrace_event_call *call = event_file_data(m->private);
846 struct ftrace_event_field *field;
847 struct list_head *common_head = &ftrace_common_fields;
848 struct list_head *head = trace_get_fields(call);
852 switch ((unsigned long)v) {
854 if (unlikely(list_empty(common_head)))
857 field = list_entry(common_head->prev,
858 struct ftrace_event_field, link);
861 case FORMAT_FIELD_SEPERATOR:
862 if (unlikely(list_empty(head)))
865 field = list_entry(head->prev, struct ftrace_event_field, link);
868 case FORMAT_PRINTFMT:
874 if (field->link.prev == common_head)
875 return (void *)FORMAT_FIELD_SEPERATOR;
876 else if (field->link.prev == head)
877 return (void *)FORMAT_PRINTFMT;
879 field = list_entry(field->link.prev, struct ftrace_event_field, link);
884 static void *f_start(struct seq_file *m, loff_t *pos)
889 /* ->stop() is called even if ->start() fails */
890 mutex_lock(&event_mutex);
891 if (!event_file_data(m->private))
892 return ERR_PTR(-ENODEV);
894 /* Start by showing the header */
896 return (void *)FORMAT_HEADER;
898 p = (void *)FORMAT_HEADER;
900 p = f_next(m, p, &l);
901 } while (p && l < *pos);
906 static int f_show(struct seq_file *m, void *v)
908 struct ftrace_event_call *call = event_file_data(m->private);
909 struct ftrace_event_field *field;
910 const char *array_descriptor;
912 switch ((unsigned long)v) {
914 seq_printf(m, "name: %s\n", call->name);
915 seq_printf(m, "ID: %d\n", call->event.type);
916 seq_printf(m, "format:\n");
919 case FORMAT_FIELD_SEPERATOR:
923 case FORMAT_PRINTFMT:
924 seq_printf(m, "\nprint fmt: %s\n",
932 * Smartly shows the array type(except dynamic array).
935 * If TYPE := TYPE[LEN], it is shown:
936 * field:TYPE VAR[LEN]
938 array_descriptor = strchr(field->type, '[');
940 if (!strncmp(field->type, "__data_loc", 10))
941 array_descriptor = NULL;
943 if (!array_descriptor)
944 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
945 field->type, field->name, field->offset,
946 field->size, !!field->is_signed);
948 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
949 (int)(array_descriptor - field->type),
950 field->type, field->name,
951 array_descriptor, field->offset,
952 field->size, !!field->is_signed);
957 static void f_stop(struct seq_file *m, void *p)
959 mutex_unlock(&event_mutex);
962 static const struct seq_operations trace_format_seq_ops = {
969 static int trace_format_open(struct inode *inode, struct file *file)
974 ret = seq_open(file, &trace_format_seq_ops);
978 m = file->private_data;
985 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
987 int id = (long)event_file_data(filp);
997 s = kmalloc(sizeof(*s), GFP_KERNEL);
1002 trace_seq_printf(s, "%d\n", id);
1004 r = simple_read_from_buffer(ubuf, cnt, ppos,
1011 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1014 struct ftrace_event_call *call;
1015 struct trace_seq *s;
1021 s = kmalloc(sizeof(*s), GFP_KERNEL);
1028 mutex_lock(&event_mutex);
1029 call = event_file_data(filp);
1031 print_event_filter(call, s);
1032 mutex_unlock(&event_mutex);
1035 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1043 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1046 struct ftrace_event_call *call;
1050 if (cnt >= PAGE_SIZE)
1053 buf = (char *)__get_free_page(GFP_TEMPORARY);
1057 if (copy_from_user(buf, ubuf, cnt)) {
1058 free_page((unsigned long) buf);
1063 mutex_lock(&event_mutex);
1064 call = event_file_data(filp);
1066 err = apply_event_filter(call, buf);
1067 mutex_unlock(&event_mutex);
1069 free_page((unsigned long) buf);
1078 static LIST_HEAD(event_subsystems);
1080 static int subsystem_open(struct inode *inode, struct file *filp)
1082 struct event_subsystem *system = NULL;
1083 struct ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1084 struct trace_array *tr;
1087 /* Make sure the system still exists */
1088 mutex_lock(&trace_types_lock);
1089 mutex_lock(&event_mutex);
1090 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1091 list_for_each_entry(dir, &tr->systems, list) {
1092 if (dir == inode->i_private) {
1093 /* Don't open systems with no events */
1094 if (dir->nr_events) {
1095 __get_system_dir(dir);
1096 system = dir->subsystem;
1103 mutex_unlock(&event_mutex);
1104 mutex_unlock(&trace_types_lock);
1109 /* Some versions of gcc think dir can be uninitialized here */
1112 /* Still need to increment the ref count of the system */
1113 if (trace_array_get(tr) < 0) {
1118 ret = tracing_open_generic(inode, filp);
1120 trace_array_put(tr);
1127 static int system_tr_open(struct inode *inode, struct file *filp)
1129 struct ftrace_subsystem_dir *dir;
1130 struct trace_array *tr = inode->i_private;
1133 if (trace_array_get(tr) < 0)
1136 /* Make a temporary dir that has no system but points to tr */
1137 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1139 trace_array_put(tr);
1145 ret = tracing_open_generic(inode, filp);
1147 trace_array_put(tr);
1151 filp->private_data = dir;
1156 static int subsystem_release(struct inode *inode, struct file *file)
1158 struct ftrace_subsystem_dir *dir = file->private_data;
1160 trace_array_put(dir->tr);
1163 * If dir->subsystem is NULL, then this is a temporary
1164 * descriptor that was made for a trace_array to enable
1176 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1179 struct ftrace_subsystem_dir *dir = filp->private_data;
1180 struct event_subsystem *system = dir->subsystem;
1181 struct trace_seq *s;
1187 s = kmalloc(sizeof(*s), GFP_KERNEL);
1193 print_subsystem_event_filter(system, s);
1194 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1202 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1205 struct ftrace_subsystem_dir *dir = filp->private_data;
1209 if (cnt >= PAGE_SIZE)
1212 buf = (char *)__get_free_page(GFP_TEMPORARY);
1216 if (copy_from_user(buf, ubuf, cnt)) {
1217 free_page((unsigned long) buf);
1222 err = apply_subsystem_event_filter(dir, buf);
1223 free_page((unsigned long) buf);
1233 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1235 int (*func)(struct trace_seq *s) = filp->private_data;
1236 struct trace_seq *s;
1242 s = kmalloc(sizeof(*s), GFP_KERNEL);
1249 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1256 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1257 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1258 static int ftrace_event_release(struct inode *inode, struct file *file);
1260 static const struct seq_operations show_event_seq_ops = {
1267 static const struct seq_operations show_set_event_seq_ops = {
1274 static const struct file_operations ftrace_avail_fops = {
1275 .open = ftrace_event_avail_open,
1277 .llseek = seq_lseek,
1278 .release = seq_release,
1281 static const struct file_operations ftrace_set_event_fops = {
1282 .open = ftrace_event_set_open,
1284 .write = ftrace_event_write,
1285 .llseek = seq_lseek,
1286 .release = ftrace_event_release,
1289 static const struct file_operations ftrace_enable_fops = {
1290 .open = tracing_open_generic,
1291 .read = event_enable_read,
1292 .write = event_enable_write,
1293 .llseek = default_llseek,
1296 static const struct file_operations ftrace_event_format_fops = {
1297 .open = trace_format_open,
1299 .llseek = seq_lseek,
1300 .release = seq_release,
1303 static const struct file_operations ftrace_event_id_fops = {
1304 .read = event_id_read,
1305 .llseek = default_llseek,
1308 static const struct file_operations ftrace_event_filter_fops = {
1309 .open = tracing_open_generic,
1310 .read = event_filter_read,
1311 .write = event_filter_write,
1312 .llseek = default_llseek,
1315 static const struct file_operations ftrace_subsystem_filter_fops = {
1316 .open = subsystem_open,
1317 .read = subsystem_filter_read,
1318 .write = subsystem_filter_write,
1319 .llseek = default_llseek,
1320 .release = subsystem_release,
1323 static const struct file_operations ftrace_system_enable_fops = {
1324 .open = subsystem_open,
1325 .read = system_enable_read,
1326 .write = system_enable_write,
1327 .llseek = default_llseek,
1328 .release = subsystem_release,
1331 static const struct file_operations ftrace_tr_enable_fops = {
1332 .open = system_tr_open,
1333 .read = system_enable_read,
1334 .write = system_enable_write,
1335 .llseek = default_llseek,
1336 .release = subsystem_release,
1339 static const struct file_operations ftrace_show_header_fops = {
1340 .open = tracing_open_generic,
1341 .read = show_header,
1342 .llseek = default_llseek,
1346 ftrace_event_open(struct inode *inode, struct file *file,
1347 const struct seq_operations *seq_ops)
1352 ret = seq_open(file, seq_ops);
1355 m = file->private_data;
1356 /* copy tr over to seq ops */
1357 m->private = inode->i_private;
1362 static int ftrace_event_release(struct inode *inode, struct file *file)
1364 struct trace_array *tr = inode->i_private;
1366 trace_array_put(tr);
1368 return seq_release(inode, file);
1372 ftrace_event_avail_open(struct inode *inode, struct file *file)
1374 const struct seq_operations *seq_ops = &show_event_seq_ops;
1376 return ftrace_event_open(inode, file, seq_ops);
1380 ftrace_event_set_open(struct inode *inode, struct file *file)
1382 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1383 struct trace_array *tr = inode->i_private;
1386 if (trace_array_get(tr) < 0)
1389 if ((file->f_mode & FMODE_WRITE) &&
1390 (file->f_flags & O_TRUNC))
1391 ftrace_clear_events(tr);
1393 ret = ftrace_event_open(inode, file, seq_ops);
1395 trace_array_put(tr);
1399 static struct event_subsystem *
1400 create_new_subsystem(const char *name)
1402 struct event_subsystem *system;
1404 /* need to create new entry */
1405 system = kmalloc(sizeof(*system), GFP_KERNEL);
1409 system->ref_count = 1;
1411 /* Only allocate if dynamic (kprobes and modules) */
1412 if (!core_kernel_data((unsigned long)name)) {
1413 system->ref_count |= SYSTEM_FL_FREE_NAME;
1414 system->name = kstrdup(name, GFP_KERNEL);
1418 system->name = name;
1420 system->filter = NULL;
1422 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1423 if (!system->filter)
1426 list_add(&system->list, &event_subsystems);
1431 if (system->ref_count & SYSTEM_FL_FREE_NAME)
1432 kfree(system->name);
1437 static struct dentry *
1438 event_subsystem_dir(struct trace_array *tr, const char *name,
1439 struct ftrace_event_file *file, struct dentry *parent)
1441 struct ftrace_subsystem_dir *dir;
1442 struct event_subsystem *system;
1443 struct dentry *entry;
1445 /* First see if we did not already create this dir */
1446 list_for_each_entry(dir, &tr->systems, list) {
1447 system = dir->subsystem;
1448 if (strcmp(system->name, name) == 0) {
1455 /* Now see if the system itself exists. */
1456 list_for_each_entry(system, &event_subsystems, list) {
1457 if (strcmp(system->name, name) == 0)
1460 /* Reset system variable when not found */
1461 if (&system->list == &event_subsystems)
1464 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1469 system = create_new_subsystem(name);
1473 __get_system(system);
1475 dir->entry = debugfs_create_dir(name, parent);
1477 pr_warning("Failed to create system directory %s\n", name);
1478 __put_system(system);
1485 dir->subsystem = system;
1488 entry = debugfs_create_file("filter", 0644, dir->entry, dir,
1489 &ftrace_subsystem_filter_fops);
1491 kfree(system->filter);
1492 system->filter = NULL;
1493 pr_warning("Could not create debugfs '%s/filter' entry\n", name);
1496 trace_create_file("enable", 0644, dir->entry, dir,
1497 &ftrace_system_enable_fops);
1499 list_add(&dir->list, &tr->systems);
1506 /* Only print this message if failed on memory allocation */
1507 if (!dir || !system)
1508 pr_warning("No memory to create event subsystem %s\n",
1514 event_create_dir(struct dentry *parent,
1515 struct ftrace_event_file *file,
1516 const struct file_operations *id,
1517 const struct file_operations *enable,
1518 const struct file_operations *filter,
1519 const struct file_operations *format)
1521 struct ftrace_event_call *call = file->event_call;
1522 struct trace_array *tr = file->tr;
1523 struct list_head *head;
1524 struct dentry *d_events;
1528 * If the trace point header did not define TRACE_SYSTEM
1529 * then the system would be called "TRACE_SYSTEM".
1531 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1532 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1538 file->dir = debugfs_create_dir(call->name, d_events);
1540 pr_warning("Could not create debugfs '%s' directory\n",
1545 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1546 trace_create_file("enable", 0644, file->dir, file,
1549 #ifdef CONFIG_PERF_EVENTS
1550 if (call->event.type && call->class->reg)
1551 trace_create_file("id", 0444, file->dir,
1552 (void *)(long)call->event.type, id);
1556 * Other events may have the same class. Only update
1557 * the fields if they are not already defined.
1559 head = trace_get_fields(call);
1560 if (list_empty(head)) {
1561 ret = call->class->define_fields(call);
1563 pr_warning("Could not initialize trace point"
1564 " events/%s\n", call->name);
1568 trace_create_file("filter", 0644, file->dir, call,
1571 trace_create_file("format", 0444, file->dir, call,
1577 static void remove_event_from_tracers(struct ftrace_event_call *call)
1579 struct ftrace_event_file *file;
1580 struct trace_array *tr;
1582 do_for_each_event_file_safe(tr, file) {
1583 if (file->event_call != call)
1586 remove_event_file_dir(file);
1588 * The do_for_each_event_file_safe() is
1589 * a double loop. After finding the call for this
1590 * trace_array, we use break to jump to the next
1594 } while_for_each_event_file();
1597 static void event_remove(struct ftrace_event_call *call)
1599 struct trace_array *tr;
1600 struct ftrace_event_file *file;
1602 do_for_each_event_file(tr, file) {
1603 if (file->event_call != call)
1605 ftrace_event_enable_disable(file, 0);
1607 * The do_for_each_event_file() is
1608 * a double loop. After finding the call for this
1609 * trace_array, we use break to jump to the next
1613 } while_for_each_event_file();
1615 if (call->event.funcs)
1616 __unregister_ftrace_event(&call->event);
1617 remove_event_from_tracers(call);
1618 list_del(&call->list);
1621 static int event_init(struct ftrace_event_call *call)
1625 if (WARN_ON(!call->name))
1628 if (call->class->raw_init) {
1629 ret = call->class->raw_init(call);
1630 if (ret < 0 && ret != -ENOSYS)
1631 pr_warn("Could not initialize trace events/%s\n",
1639 __register_event(struct ftrace_event_call *call, struct module *mod)
1643 ret = event_init(call);
1647 list_add(&call->list, &ftrace_events);
1653 static struct ftrace_event_file *
1654 trace_create_new_event(struct ftrace_event_call *call,
1655 struct trace_array *tr)
1657 struct ftrace_event_file *file;
1659 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
1663 file->event_call = call;
1665 atomic_set(&file->sm_ref, 0);
1666 list_add(&file->list, &tr->events);
1671 /* Add an event to a trace directory */
1673 __trace_add_new_event(struct ftrace_event_call *call,
1674 struct trace_array *tr,
1675 const struct file_operations *id,
1676 const struct file_operations *enable,
1677 const struct file_operations *filter,
1678 const struct file_operations *format)
1680 struct ftrace_event_file *file;
1682 file = trace_create_new_event(call, tr);
1686 return event_create_dir(tr->event_dir, file, id, enable, filter, format);
1690 * Just create a decriptor for early init. A descriptor is required
1691 * for enabling events at boot. We want to enable events before
1692 * the filesystem is initialized.
1695 __trace_early_add_new_event(struct ftrace_event_call *call,
1696 struct trace_array *tr)
1698 struct ftrace_event_file *file;
1700 file = trace_create_new_event(call, tr);
1707 struct ftrace_module_file_ops;
1708 static void __add_event_to_tracers(struct ftrace_event_call *call,
1709 struct ftrace_module_file_ops *file_ops);
1711 /* Add an additional event_call dynamically */
1712 int trace_add_event_call(struct ftrace_event_call *call)
1715 mutex_lock(&trace_types_lock);
1716 mutex_lock(&event_mutex);
1718 ret = __register_event(call, NULL);
1720 __add_event_to_tracers(call, NULL);
1722 mutex_unlock(&event_mutex);
1723 mutex_unlock(&trace_types_lock);
1728 * Must be called under locking of trace_types_lock, event_mutex and
1731 static void __trace_remove_event_call(struct ftrace_event_call *call)
1734 trace_destroy_fields(call);
1735 destroy_preds(call);
1738 static int probe_remove_event_call(struct ftrace_event_call *call)
1740 struct trace_array *tr;
1741 struct ftrace_event_file *file;
1743 #ifdef CONFIG_PERF_EVENTS
1744 if (call->perf_refcount)
1747 do_for_each_event_file(tr, file) {
1748 if (file->event_call != call)
1751 * We can't rely on ftrace_event_enable_disable(enable => 0)
1752 * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
1753 * TRACE_REG_UNREGISTER.
1755 if (file->flags & FTRACE_EVENT_FL_ENABLED)
1758 } while_for_each_event_file();
1760 __trace_remove_event_call(call);
1765 /* Remove an event_call */
1766 int trace_remove_event_call(struct ftrace_event_call *call)
1770 mutex_lock(&trace_types_lock);
1771 mutex_lock(&event_mutex);
1772 down_write(&trace_event_sem);
1773 ret = probe_remove_event_call(call);
1774 up_write(&trace_event_sem);
1775 mutex_unlock(&event_mutex);
1776 mutex_unlock(&trace_types_lock);
1781 #define for_each_event(event, start, end) \
1782 for (event = start; \
1783 (unsigned long)event < (unsigned long)end; \
1786 #ifdef CONFIG_MODULES
1788 static LIST_HEAD(ftrace_module_file_list);
1791 * Modules must own their file_operations to keep up with
1792 * reference counting.
1794 struct ftrace_module_file_ops {
1795 struct list_head list;
1797 struct file_operations id;
1798 struct file_operations enable;
1799 struct file_operations format;
1800 struct file_operations filter;
1803 static struct ftrace_module_file_ops *
1804 find_ftrace_file_ops(struct ftrace_module_file_ops *file_ops, struct module *mod)
1807 * As event_calls are added in groups by module,
1808 * when we find one file_ops, we don't need to search for
1809 * each call in that module, as the rest should be the
1810 * same. Only search for a new one if the last one did
1813 if (file_ops && mod == file_ops->mod)
1816 list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1817 if (file_ops->mod == mod)
1823 static struct ftrace_module_file_ops *
1824 trace_create_file_ops(struct module *mod)
1826 struct ftrace_module_file_ops *file_ops;
1829 * This is a bit of a PITA. To allow for correct reference
1830 * counting, modules must "own" their file_operations.
1831 * To do this, we allocate the file operations that will be
1832 * used in the event directory.
1835 file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1839 file_ops->mod = mod;
1841 file_ops->id = ftrace_event_id_fops;
1842 file_ops->id.owner = mod;
1844 file_ops->enable = ftrace_enable_fops;
1845 file_ops->enable.owner = mod;
1847 file_ops->filter = ftrace_event_filter_fops;
1848 file_ops->filter.owner = mod;
1850 file_ops->format = ftrace_event_format_fops;
1851 file_ops->format.owner = mod;
1853 list_add(&file_ops->list, &ftrace_module_file_list);
1858 static void trace_module_add_events(struct module *mod)
1860 struct ftrace_module_file_ops *file_ops = NULL;
1861 struct ftrace_event_call **call, **start, **end;
1863 start = mod->trace_events;
1864 end = mod->trace_events + mod->num_trace_events;
1869 file_ops = trace_create_file_ops(mod);
1873 for_each_event(call, start, end) {
1874 __register_event(*call, mod);
1875 __add_event_to_tracers(*call, file_ops);
1879 static void trace_module_remove_events(struct module *mod)
1881 struct ftrace_module_file_ops *file_ops;
1882 struct ftrace_event_call *call, *p;
1883 bool clear_trace = false;
1885 down_write(&trace_event_sem);
1886 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1887 if (call->mod == mod) {
1888 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
1890 __trace_remove_event_call(call);
1894 /* Now free the file_operations */
1895 list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1896 if (file_ops->mod == mod)
1899 if (&file_ops->list != &ftrace_module_file_list) {
1900 list_del(&file_ops->list);
1903 up_write(&trace_event_sem);
1906 * It is safest to reset the ring buffer if the module being unloaded
1907 * registered any events that were used. The only worry is if
1908 * a new module gets loaded, and takes on the same id as the events
1909 * of this module. When printing out the buffer, traced events left
1910 * over from this module may be passed to the new module events and
1911 * unexpected results may occur.
1914 tracing_reset_all_online_cpus();
1917 static int trace_module_notify(struct notifier_block *self,
1918 unsigned long val, void *data)
1920 struct module *mod = data;
1922 mutex_lock(&trace_types_lock);
1923 mutex_lock(&event_mutex);
1925 case MODULE_STATE_COMING:
1926 trace_module_add_events(mod);
1928 case MODULE_STATE_GOING:
1929 trace_module_remove_events(mod);
1932 mutex_unlock(&event_mutex);
1933 mutex_unlock(&trace_types_lock);
1939 __trace_add_new_mod_event(struct ftrace_event_call *call,
1940 struct trace_array *tr,
1941 struct ftrace_module_file_ops *file_ops)
1943 return __trace_add_new_event(call, tr,
1944 &file_ops->id, &file_ops->enable,
1945 &file_ops->filter, &file_ops->format);
1949 static inline struct ftrace_module_file_ops *
1950 find_ftrace_file_ops(struct ftrace_module_file_ops *file_ops, struct module *mod)
1954 static inline int trace_module_notify(struct notifier_block *self,
1955 unsigned long val, void *data)
1960 __trace_add_new_mod_event(struct ftrace_event_call *call,
1961 struct trace_array *tr,
1962 struct ftrace_module_file_ops *file_ops)
1966 #endif /* CONFIG_MODULES */
1968 /* Create a new event directory structure for a trace directory. */
1970 __trace_add_event_dirs(struct trace_array *tr)
1972 struct ftrace_module_file_ops *file_ops = NULL;
1973 struct ftrace_event_call *call;
1976 list_for_each_entry(call, &ftrace_events, list) {
1979 * Directories for events by modules need to
1980 * keep module ref counts when opened (as we don't
1981 * want the module to disappear when reading one
1982 * of these files). The file_ops keep account of
1983 * the module ref count.
1985 file_ops = find_ftrace_file_ops(file_ops, call->mod);
1987 continue; /* Warn? */
1988 ret = __trace_add_new_mod_event(call, tr, file_ops);
1990 pr_warning("Could not create directory for event %s\n",
1994 ret = __trace_add_new_event(call, tr,
1995 &ftrace_event_id_fops,
1996 &ftrace_enable_fops,
1997 &ftrace_event_filter_fops,
1998 &ftrace_event_format_fops);
2000 pr_warning("Could not create directory for event %s\n",
2005 #ifdef CONFIG_DYNAMIC_FTRACE
2008 #define ENABLE_EVENT_STR "enable_event"
2009 #define DISABLE_EVENT_STR "disable_event"
2011 struct event_probe_data {
2012 struct ftrace_event_file *file;
2013 unsigned long count;
2018 static struct ftrace_event_file *
2019 find_event_file(struct trace_array *tr, const char *system, const char *event)
2021 struct ftrace_event_file *file;
2022 struct ftrace_event_call *call;
2024 list_for_each_entry(file, &tr->events, list) {
2026 call = file->event_call;
2028 if (!call->name || !call->class || !call->class->reg)
2031 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2034 if (strcmp(event, call->name) == 0 &&
2035 strcmp(system, call->class->system) == 0)
2042 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2044 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2045 struct event_probe_data *data = *pdata;
2051 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
2053 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
2057 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2059 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2060 struct event_probe_data *data = *pdata;
2068 /* Skip if the event is in a state we want to switch to */
2069 if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
2072 if (data->count != -1)
2075 event_enable_probe(ip, parent_ip, _data);
2079 event_enable_print(struct seq_file *m, unsigned long ip,
2080 struct ftrace_probe_ops *ops, void *_data)
2082 struct event_probe_data *data = _data;
2084 seq_printf(m, "%ps:", (void *)ip);
2086 seq_printf(m, "%s:%s:%s",
2087 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2088 data->file->event_call->class->system,
2089 data->file->event_call->name);
2091 if (data->count == -1)
2092 seq_printf(m, ":unlimited\n");
2094 seq_printf(m, ":count=%ld\n", data->count);
2100 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
2103 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2104 struct event_probe_data *data = *pdata;
2111 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
2114 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2115 struct event_probe_data *data = *pdata;
2117 if (WARN_ON_ONCE(data->ref <= 0))
2122 /* Remove the SOFT_MODE flag */
2123 __ftrace_event_enable_disable(data->file, 0, 1);
2124 module_put(data->file->event_call->mod);
2130 static struct ftrace_probe_ops event_enable_probe_ops = {
2131 .func = event_enable_probe,
2132 .print = event_enable_print,
2133 .init = event_enable_init,
2134 .free = event_enable_free,
2137 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2138 .func = event_enable_count_probe,
2139 .print = event_enable_print,
2140 .init = event_enable_init,
2141 .free = event_enable_free,
2144 static struct ftrace_probe_ops event_disable_probe_ops = {
2145 .func = event_enable_probe,
2146 .print = event_enable_print,
2147 .init = event_enable_init,
2148 .free = event_enable_free,
2151 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2152 .func = event_enable_count_probe,
2153 .print = event_enable_print,
2154 .init = event_enable_init,
2155 .free = event_enable_free,
2159 event_enable_func(struct ftrace_hash *hash,
2160 char *glob, char *cmd, char *param, int enabled)
2162 struct trace_array *tr = top_trace_array();
2163 struct ftrace_event_file *file;
2164 struct ftrace_probe_ops *ops;
2165 struct event_probe_data *data;
2172 /* hash funcs only work with set_ftrace_filter */
2179 system = strsep(¶m, ":");
2183 event = strsep(¶m, ":");
2185 mutex_lock(&event_mutex);
2188 file = find_event_file(tr, system, event);
2192 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2195 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2197 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2199 if (glob[0] == '!') {
2200 unregister_ftrace_function_probe_func(glob+1, ops);
2206 data = kzalloc(sizeof(*data), GFP_KERNEL);
2210 data->enable = enable;
2217 number = strsep(¶m, ":");
2220 if (!strlen(number))
2224 * We use the callback data field (which is a pointer)
2227 ret = kstrtoul(number, 0, &data->count);
2232 /* Don't let event modules unload while probe registered */
2233 ret = try_module_get(file->event_call->mod);
2239 ret = __ftrace_event_enable_disable(file, 1, 1);
2242 ret = register_ftrace_function_probe(glob, ops, data);
2244 * The above returns on success the # of functions enabled,
2245 * but if it didn't find any functions it returns zero.
2246 * Consider no functions a failure too.
2253 /* Just return zero, not the number of enabled functions */
2256 mutex_unlock(&event_mutex);
2260 __ftrace_event_enable_disable(file, 0, 1);
2262 module_put(file->event_call->mod);
2268 static struct ftrace_func_command event_enable_cmd = {
2269 .name = ENABLE_EVENT_STR,
2270 .func = event_enable_func,
2273 static struct ftrace_func_command event_disable_cmd = {
2274 .name = DISABLE_EVENT_STR,
2275 .func = event_enable_func,
2278 static __init int register_event_cmds(void)
2282 ret = register_ftrace_command(&event_enable_cmd);
2283 if (WARN_ON(ret < 0))
2285 ret = register_ftrace_command(&event_disable_cmd);
2286 if (WARN_ON(ret < 0))
2287 unregister_ftrace_command(&event_enable_cmd);
2291 static inline int register_event_cmds(void) { return 0; }
2292 #endif /* CONFIG_DYNAMIC_FTRACE */
2295 * The top level array has already had its ftrace_event_file
2296 * descriptors created in order to allow for early events to
2297 * be recorded. This function is called after the debugfs has been
2298 * initialized, and we now have to create the files associated
2302 __trace_early_add_event_dirs(struct trace_array *tr)
2304 struct ftrace_event_file *file;
2308 list_for_each_entry(file, &tr->events, list) {
2309 ret = event_create_dir(tr->event_dir, file,
2310 &ftrace_event_id_fops,
2311 &ftrace_enable_fops,
2312 &ftrace_event_filter_fops,
2313 &ftrace_event_format_fops);
2315 pr_warning("Could not create directory for event %s\n",
2316 file->event_call->name);
2321 * For early boot up, the top trace array requires to have
2322 * a list of events that can be enabled. This must be done before
2323 * the filesystem is set up in order to allow events to be traced
2327 __trace_early_add_events(struct trace_array *tr)
2329 struct ftrace_event_call *call;
2332 list_for_each_entry(call, &ftrace_events, list) {
2333 /* Early boot up should not have any modules loaded */
2334 if (WARN_ON_ONCE(call->mod))
2337 ret = __trace_early_add_new_event(call, tr);
2339 pr_warning("Could not create early event %s\n",
2344 /* Remove the event directory structure for a trace directory. */
2346 __trace_remove_event_dirs(struct trace_array *tr)
2348 struct ftrace_event_file *file, *next;
2350 list_for_each_entry_safe(file, next, &tr->events, list)
2351 remove_event_file_dir(file);
2355 __add_event_to_tracers(struct ftrace_event_call *call,
2356 struct ftrace_module_file_ops *file_ops)
2358 struct trace_array *tr;
2360 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
2362 __trace_add_new_mod_event(call, tr, file_ops);
2364 __trace_add_new_event(call, tr,
2365 &ftrace_event_id_fops,
2366 &ftrace_enable_fops,
2367 &ftrace_event_filter_fops,
2368 &ftrace_event_format_fops);
2372 static struct notifier_block trace_module_nb = {
2373 .notifier_call = trace_module_notify,
2377 extern struct ftrace_event_call *__start_ftrace_events[];
2378 extern struct ftrace_event_call *__stop_ftrace_events[];
2380 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2382 static __init int setup_trace_event(char *str)
2384 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2385 ring_buffer_expanded = true;
2386 tracing_selftest_disabled = true;
2390 __setup("trace_event=", setup_trace_event);
2392 /* Expects to have event_mutex held when called */
2394 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2396 struct dentry *d_events;
2397 struct dentry *entry;
2399 entry = debugfs_create_file("set_event", 0644, parent,
2400 tr, &ftrace_set_event_fops);
2402 pr_warning("Could not create debugfs 'set_event' entry\n");
2406 d_events = debugfs_create_dir("events", parent);
2408 pr_warning("Could not create debugfs 'events' directory\n");
2412 /* ring buffer internal formats */
2413 trace_create_file("header_page", 0444, d_events,
2414 ring_buffer_print_page_header,
2415 &ftrace_show_header_fops);
2417 trace_create_file("header_event", 0444, d_events,
2418 ring_buffer_print_entry_header,
2419 &ftrace_show_header_fops);
2421 trace_create_file("enable", 0644, d_events,
2422 tr, &ftrace_tr_enable_fops);
2424 tr->event_dir = d_events;
2430 * event_trace_add_tracer - add a instance of a trace_array to events
2431 * @parent: The parent dentry to place the files/directories for events in
2432 * @tr: The trace array associated with these events
2434 * When a new instance is created, it needs to set up its events
2435 * directory, as well as other files associated with events. It also
2436 * creates the event hierachry in the @parent/events directory.
2438 * Returns 0 on success.
2440 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2444 mutex_lock(&event_mutex);
2446 ret = create_event_toplevel_files(parent, tr);
2450 down_write(&trace_event_sem);
2451 __trace_add_event_dirs(tr);
2452 up_write(&trace_event_sem);
2455 mutex_unlock(&event_mutex);
2461 * The top trace array already had its file descriptors created.
2462 * Now the files themselves need to be created.
2465 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2469 mutex_lock(&event_mutex);
2471 ret = create_event_toplevel_files(parent, tr);
2475 down_write(&trace_event_sem);
2476 __trace_early_add_event_dirs(tr);
2477 up_write(&trace_event_sem);
2480 mutex_unlock(&event_mutex);
2485 int event_trace_del_tracer(struct trace_array *tr)
2487 mutex_lock(&event_mutex);
2489 /* Disable any running events */
2490 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
2492 down_write(&trace_event_sem);
2493 __trace_remove_event_dirs(tr);
2494 debugfs_remove_recursive(tr->event_dir);
2495 up_write(&trace_event_sem);
2497 tr->event_dir = NULL;
2499 mutex_unlock(&event_mutex);
2504 static __init int event_trace_memsetup(void)
2506 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
2507 file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC);
2511 static __init int event_trace_enable(void)
2513 struct trace_array *tr = top_trace_array();
2514 struct ftrace_event_call **iter, *call;
2515 char *buf = bootup_event_buf;
2519 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
2522 ret = event_init(call);
2524 list_add(&call->list, &ftrace_events);
2528 * We need the top trace array to have a working set of trace
2529 * points at early init, before the debug files and directories
2530 * are created. Create the file entries now, and attach them
2531 * to the actual file dentries later.
2533 __trace_early_add_events(tr);
2536 token = strsep(&buf, ",");
2543 ret = ftrace_set_clr_event(tr, token, 1);
2545 pr_warn("Failed to enable trace event: %s\n", token);
2548 trace_printk_start_comm();
2550 register_event_cmds();
2555 static __init int event_trace_init(void)
2557 struct trace_array *tr;
2558 struct dentry *d_tracer;
2559 struct dentry *entry;
2562 tr = top_trace_array();
2564 d_tracer = tracing_init_dentry();
2568 entry = debugfs_create_file("available_events", 0444, d_tracer,
2569 tr, &ftrace_avail_fops);
2571 pr_warning("Could not create debugfs "
2572 "'available_events' entry\n");
2574 if (trace_define_common_fields())
2575 pr_warning("tracing: Failed to allocate common fields");
2577 ret = early_event_add_tracer(d_tracer, tr);
2581 ret = register_module_notifier(&trace_module_nb);
2583 pr_warning("Failed to register trace events module notifier\n");
2587 early_initcall(event_trace_memsetup);
2588 core_initcall(event_trace_enable);
2589 fs_initcall(event_trace_init);
2591 #ifdef CONFIG_FTRACE_STARTUP_TEST
2593 static DEFINE_SPINLOCK(test_spinlock);
2594 static DEFINE_SPINLOCK(test_spinlock_irq);
2595 static DEFINE_MUTEX(test_mutex);
2597 static __init void test_work(struct work_struct *dummy)
2599 spin_lock(&test_spinlock);
2600 spin_lock_irq(&test_spinlock_irq);
2602 spin_unlock_irq(&test_spinlock_irq);
2603 spin_unlock(&test_spinlock);
2605 mutex_lock(&test_mutex);
2607 mutex_unlock(&test_mutex);
2610 static __init int event_test_thread(void *unused)
2614 test_malloc = kmalloc(1234, GFP_KERNEL);
2616 pr_info("failed to kmalloc\n");
2618 schedule_on_each_cpu(test_work);
2622 set_current_state(TASK_INTERRUPTIBLE);
2623 while (!kthread_should_stop())
2630 * Do various things that may trigger events.
2632 static __init void event_test_stuff(void)
2634 struct task_struct *test_thread;
2636 test_thread = kthread_run(event_test_thread, NULL, "test-events");
2638 kthread_stop(test_thread);
2642 * For every trace event defined, we will test each trace point separately,
2643 * and then by groups, and finally all trace points.
2645 static __init void event_trace_self_tests(void)
2647 struct ftrace_subsystem_dir *dir;
2648 struct ftrace_event_file *file;
2649 struct ftrace_event_call *call;
2650 struct event_subsystem *system;
2651 struct trace_array *tr;
2654 tr = top_trace_array();
2656 pr_info("Running tests on trace events:\n");
2658 list_for_each_entry(file, &tr->events, list) {
2660 call = file->event_call;
2662 /* Only test those that have a probe */
2663 if (!call->class || !call->class->probe)
2667 * Testing syscall events here is pretty useless, but
2668 * we still do it if configured. But this is time consuming.
2669 * What we really need is a user thread to perform the
2670 * syscalls as we test.
2672 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
2673 if (call->class->system &&
2674 strcmp(call->class->system, "syscalls") == 0)
2678 pr_info("Testing event %s: ", call->name);
2681 * If an event is already enabled, someone is using
2682 * it and the self test should not be on.
2684 if (file->flags & FTRACE_EVENT_FL_ENABLED) {
2685 pr_warning("Enabled event during self test!\n");
2690 ftrace_event_enable_disable(file, 1);
2692 ftrace_event_enable_disable(file, 0);
2697 /* Now test at the sub system level */
2699 pr_info("Running tests on trace event systems:\n");
2701 list_for_each_entry(dir, &tr->systems, list) {
2703 system = dir->subsystem;
2705 /* the ftrace system is special, skip it */
2706 if (strcmp(system->name, "ftrace") == 0)
2709 pr_info("Testing event system %s: ", system->name);
2711 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
2712 if (WARN_ON_ONCE(ret)) {
2713 pr_warning("error enabling system %s\n",
2720 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
2721 if (WARN_ON_ONCE(ret)) {
2722 pr_warning("error disabling system %s\n",
2730 /* Test with all events enabled */
2732 pr_info("Running tests on all trace events:\n");
2733 pr_info("Testing all events: ");
2735 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
2736 if (WARN_ON_ONCE(ret)) {
2737 pr_warning("error enabling all events\n");
2744 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
2745 if (WARN_ON_ONCE(ret)) {
2746 pr_warning("error disabling all events\n");
2753 #ifdef CONFIG_FUNCTION_TRACER
2755 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
2758 function_test_events_call(unsigned long ip, unsigned long parent_ip,
2759 struct ftrace_ops *op, struct pt_regs *pt_regs)
2761 struct ring_buffer_event *event;
2762 struct ring_buffer *buffer;
2763 struct ftrace_entry *entry;
2764 unsigned long flags;
2769 pc = preempt_count();
2770 preempt_disable_notrace();
2771 cpu = raw_smp_processor_id();
2772 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
2777 local_save_flags(flags);
2779 event = trace_current_buffer_lock_reserve(&buffer,
2780 TRACE_FN, sizeof(*entry),
2784 entry = ring_buffer_event_data(event);
2786 entry->parent_ip = parent_ip;
2788 trace_buffer_unlock_commit(buffer, event, flags, pc);
2791 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
2792 preempt_enable_notrace();
2795 static struct ftrace_ops trace_ops __initdata =
2797 .func = function_test_events_call,
2798 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
2801 static __init void event_trace_self_test_with_function(void)
2804 ret = register_ftrace_function(&trace_ops);
2805 if (WARN_ON(ret < 0)) {
2806 pr_info("Failed to enable function tracer for event tests\n");
2809 pr_info("Running tests again, along with the function tracer\n");
2810 event_trace_self_tests();
2811 unregister_ftrace_function(&trace_ops);
2814 static __init void event_trace_self_test_with_function(void)
2819 static __init int event_trace_self_tests_init(void)
2821 if (!tracing_selftest_disabled) {
2822 event_trace_self_tests();
2823 event_trace_self_test_with_function();
2829 late_initcall(event_trace_self_tests_init);