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 /* Double loops, do not use break, only goto's work */
45 #define do_for_each_event_file(tr, file) \
46 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
47 list_for_each_entry(file, &tr->events, list)
49 #define do_for_each_event_file_safe(tr, file) \
50 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
51 struct ftrace_event_file *___n; \
52 list_for_each_entry_safe(file, ___n, &tr->events, list)
54 #define while_for_each_event_file() \
57 static struct list_head *
58 trace_get_fields(struct ftrace_event_call *event_call)
60 if (!event_call->class->get_fields)
61 return &event_call->class->fields;
62 return event_call->class->get_fields(event_call);
65 static struct ftrace_event_field *
66 __find_event_field(struct list_head *head, char *name)
68 struct ftrace_event_field *field;
70 list_for_each_entry(field, head, link) {
71 if (!strcmp(field->name, name))
78 struct ftrace_event_field *
79 trace_find_event_field(struct ftrace_event_call *call, char *name)
81 struct ftrace_event_field *field;
82 struct list_head *head;
84 field = __find_event_field(&ftrace_common_fields, name);
88 head = trace_get_fields(call);
89 return __find_event_field(head, name);
92 static int __trace_define_field(struct list_head *head, const char *type,
93 const char *name, int offset, int size,
94 int is_signed, int filter_type)
96 struct ftrace_event_field *field;
98 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
105 if (filter_type == FILTER_OTHER)
106 field->filter_type = filter_assign_type(type);
108 field->filter_type = filter_type;
110 field->offset = offset;
112 field->is_signed = is_signed;
114 list_add(&field->link, head);
119 kmem_cache_free(field_cachep, field);
124 int trace_define_field(struct ftrace_event_call *call, const char *type,
125 const char *name, int offset, int size, int is_signed,
128 struct list_head *head;
130 if (WARN_ON(!call->class))
133 head = trace_get_fields(call);
134 return __trace_define_field(head, type, name, offset, size,
135 is_signed, filter_type);
137 EXPORT_SYMBOL_GPL(trace_define_field);
139 #define __common_field(type, item) \
140 ret = __trace_define_field(&ftrace_common_fields, #type, \
142 offsetof(typeof(ent), item), \
144 is_signed_type(type), FILTER_OTHER); \
148 static int trace_define_common_fields(void)
151 struct trace_entry ent;
153 __common_field(unsigned short, type);
154 __common_field(unsigned char, flags);
155 __common_field(unsigned char, preempt_count);
156 __common_field(int, pid);
161 static void trace_destroy_fields(struct ftrace_event_call *call)
163 struct ftrace_event_field *field, *next;
164 struct list_head *head;
166 head = trace_get_fields(call);
167 list_for_each_entry_safe(field, next, head, link) {
168 list_del(&field->link);
169 kmem_cache_free(field_cachep, field);
173 int trace_event_raw_init(struct ftrace_event_call *call)
177 id = register_ftrace_event(&call->event);
183 EXPORT_SYMBOL_GPL(trace_event_raw_init);
185 int ftrace_event_reg(struct ftrace_event_call *call,
186 enum trace_reg type, void *data)
188 struct ftrace_event_file *file = data;
191 case TRACE_REG_REGISTER:
192 return tracepoint_probe_register(call->name,
195 case TRACE_REG_UNREGISTER:
196 tracepoint_probe_unregister(call->name,
201 #ifdef CONFIG_PERF_EVENTS
202 case TRACE_REG_PERF_REGISTER:
203 return tracepoint_probe_register(call->name,
204 call->class->perf_probe,
206 case TRACE_REG_PERF_UNREGISTER:
207 tracepoint_probe_unregister(call->name,
208 call->class->perf_probe,
211 case TRACE_REG_PERF_OPEN:
212 case TRACE_REG_PERF_CLOSE:
213 case TRACE_REG_PERF_ADD:
214 case TRACE_REG_PERF_DEL:
220 EXPORT_SYMBOL_GPL(ftrace_event_reg);
222 void trace_event_enable_cmd_record(bool enable)
224 struct ftrace_event_file *file;
225 struct trace_array *tr;
227 mutex_lock(&event_mutex);
228 do_for_each_event_file(tr, file) {
230 if (!(file->flags & FTRACE_EVENT_FL_ENABLED))
234 tracing_start_cmdline_record();
235 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
237 tracing_stop_cmdline_record();
238 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
240 } while_for_each_event_file();
241 mutex_unlock(&event_mutex);
244 static int __ftrace_event_enable_disable(struct ftrace_event_file *file,
245 int enable, int soft_disable)
247 struct ftrace_event_call *call = file->event_call;
254 * When soft_disable is set and enable is cleared, the sm_ref
255 * reference counter is decremented. If it reaches 0, we want
256 * to clear the SOFT_DISABLED flag but leave the event in the
257 * state that it was. That is, if the event was enabled and
258 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
259 * is set we do not want the event to be enabled before we
262 * When soft_disable is not set but the SOFT_MODE flag is,
263 * we do nothing. Do not disable the tracepoint, otherwise
264 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
267 if (atomic_dec_return(&file->sm_ref) > 0)
269 disable = file->flags & FTRACE_EVENT_FL_SOFT_DISABLED;
270 clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
272 disable = !(file->flags & FTRACE_EVENT_FL_SOFT_MODE);
274 if (disable && (file->flags & FTRACE_EVENT_FL_ENABLED)) {
275 clear_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
276 if (file->flags & FTRACE_EVENT_FL_RECORDED_CMD) {
277 tracing_stop_cmdline_record();
278 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
280 call->class->reg(call, TRACE_REG_UNREGISTER, file);
282 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT */
283 if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
284 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
288 * When soft_disable is set and enable is set, we want to
289 * register the tracepoint for the event, but leave the event
290 * as is. That means, if the event was already enabled, we do
291 * nothing (but set SOFT_MODE). If the event is disabled, we
292 * set SOFT_DISABLED before enabling the event tracepoint, so
293 * it still seems to be disabled.
296 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
298 if (atomic_inc_return(&file->sm_ref) > 1)
300 set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
303 if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) {
305 /* Keep the event disabled, when going to SOFT_MODE. */
307 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
309 if (trace_flags & TRACE_ITER_RECORD_CMD) {
310 tracing_start_cmdline_record();
311 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
313 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
315 tracing_stop_cmdline_record();
316 pr_info("event trace: Could not enable event "
320 set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
322 /* WAS_ENABLED gets set but never cleared. */
323 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
331 static int ftrace_event_enable_disable(struct ftrace_event_file *file,
334 return __ftrace_event_enable_disable(file, enable, 0);
337 static void ftrace_clear_events(struct trace_array *tr)
339 struct ftrace_event_file *file;
341 mutex_lock(&event_mutex);
342 list_for_each_entry(file, &tr->events, list) {
343 ftrace_event_enable_disable(file, 0);
345 mutex_unlock(&event_mutex);
348 static void __put_system(struct event_subsystem *system)
350 struct event_filter *filter = system->filter;
352 WARN_ON_ONCE(system->ref_count == 0);
353 if (--system->ref_count)
356 list_del(&system->list);
359 kfree(filter->filter_string);
365 static void __get_system(struct event_subsystem *system)
367 WARN_ON_ONCE(system->ref_count == 0);
371 static void __get_system_dir(struct ftrace_subsystem_dir *dir)
373 WARN_ON_ONCE(dir->ref_count == 0);
375 __get_system(dir->subsystem);
378 static void __put_system_dir(struct ftrace_subsystem_dir *dir)
380 WARN_ON_ONCE(dir->ref_count == 0);
381 /* If the subsystem is about to be freed, the dir must be too */
382 WARN_ON_ONCE(dir->subsystem->ref_count == 1 && dir->ref_count != 1);
384 __put_system(dir->subsystem);
385 if (!--dir->ref_count)
389 static void put_system(struct ftrace_subsystem_dir *dir)
391 mutex_lock(&event_mutex);
392 __put_system_dir(dir);
393 mutex_unlock(&event_mutex);
397 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
399 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
400 const char *sub, const char *event, int set)
402 struct ftrace_event_file *file;
403 struct ftrace_event_call *call;
406 mutex_lock(&event_mutex);
407 list_for_each_entry(file, &tr->events, list) {
409 call = file->event_call;
411 if (!call->name || !call->class || !call->class->reg)
414 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
418 strcmp(match, call->name) != 0 &&
419 strcmp(match, call->class->system) != 0)
422 if (sub && strcmp(sub, call->class->system) != 0)
425 if (event && strcmp(event, call->name) != 0)
428 ftrace_event_enable_disable(file, set);
432 mutex_unlock(&event_mutex);
437 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
439 char *event = NULL, *sub = NULL, *match;
442 * The buf format can be <subsystem>:<event-name>
443 * *:<event-name> means any event by that name.
444 * :<event-name> is the same.
446 * <subsystem>:* means all events in that subsystem
447 * <subsystem>: means the same.
449 * <name> (no ':') means all events in a subsystem with
450 * the name <name> or any event that matches <name>
453 match = strsep(&buf, ":");
459 if (!strlen(sub) || strcmp(sub, "*") == 0)
461 if (!strlen(event) || strcmp(event, "*") == 0)
465 return __ftrace_set_clr_event(tr, match, sub, event, set);
469 * trace_set_clr_event - enable or disable an event
470 * @system: system name to match (NULL for any system)
471 * @event: event name to match (NULL for all events, within system)
472 * @set: 1 to enable, 0 to disable
474 * This is a way for other parts of the kernel to enable or disable
477 * Returns 0 on success, -EINVAL if the parameters do not match any
480 int trace_set_clr_event(const char *system, const char *event, int set)
482 struct trace_array *tr = top_trace_array();
484 return __ftrace_set_clr_event(tr, NULL, system, event, set);
486 EXPORT_SYMBOL_GPL(trace_set_clr_event);
488 /* 128 should be much more than enough */
489 #define EVENT_BUF_SIZE 127
492 ftrace_event_write(struct file *file, const char __user *ubuf,
493 size_t cnt, loff_t *ppos)
495 struct trace_parser parser;
496 struct seq_file *m = file->private_data;
497 struct trace_array *tr = m->private;
503 ret = tracing_update_buffers();
507 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
510 read = trace_get_user(&parser, ubuf, cnt, ppos);
512 if (read >= 0 && trace_parser_loaded((&parser))) {
515 if (*parser.buffer == '!')
518 parser.buffer[parser.idx] = 0;
520 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
528 trace_parser_put(&parser);
534 t_next(struct seq_file *m, void *v, loff_t *pos)
536 struct ftrace_event_file *file = v;
537 struct ftrace_event_call *call;
538 struct trace_array *tr = m->private;
542 list_for_each_entry_continue(file, &tr->events, list) {
543 call = file->event_call;
545 * The ftrace subsystem is for showing formats only.
546 * They can not be enabled or disabled via the event files.
548 if (call->class && call->class->reg)
555 static void *t_start(struct seq_file *m, loff_t *pos)
557 struct ftrace_event_file *file;
558 struct trace_array *tr = m->private;
561 mutex_lock(&event_mutex);
563 file = list_entry(&tr->events, struct ftrace_event_file, list);
564 for (l = 0; l <= *pos; ) {
565 file = t_next(m, file, &l);
573 s_next(struct seq_file *m, void *v, loff_t *pos)
575 struct ftrace_event_file *file = v;
576 struct trace_array *tr = m->private;
580 list_for_each_entry_continue(file, &tr->events, list) {
581 if (file->flags & FTRACE_EVENT_FL_ENABLED)
588 static void *s_start(struct seq_file *m, loff_t *pos)
590 struct ftrace_event_file *file;
591 struct trace_array *tr = m->private;
594 mutex_lock(&event_mutex);
596 file = list_entry(&tr->events, struct ftrace_event_file, list);
597 for (l = 0; l <= *pos; ) {
598 file = s_next(m, file, &l);
605 static int t_show(struct seq_file *m, void *v)
607 struct ftrace_event_file *file = v;
608 struct ftrace_event_call *call = file->event_call;
610 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
611 seq_printf(m, "%s:", call->class->system);
612 seq_printf(m, "%s\n", call->name);
617 static void t_stop(struct seq_file *m, void *p)
619 mutex_unlock(&event_mutex);
623 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
626 struct ftrace_event_file *file = filp->private_data;
629 if (file->flags & FTRACE_EVENT_FL_ENABLED) {
630 if (file->flags & FTRACE_EVENT_FL_SOFT_DISABLED)
632 else if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
639 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
643 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
646 struct ftrace_event_file *file = filp->private_data;
653 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
657 ret = tracing_update_buffers();
664 mutex_lock(&event_mutex);
665 ret = ftrace_event_enable_disable(file, val);
666 mutex_unlock(&event_mutex);
675 return ret ? ret : cnt;
679 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
682 const char set_to_char[4] = { '?', '0', '1', 'X' };
683 struct ftrace_subsystem_dir *dir = filp->private_data;
684 struct event_subsystem *system = dir->subsystem;
685 struct ftrace_event_call *call;
686 struct ftrace_event_file *file;
687 struct trace_array *tr = dir->tr;
692 mutex_lock(&event_mutex);
693 list_for_each_entry(file, &tr->events, list) {
694 call = file->event_call;
695 if (!call->name || !call->class || !call->class->reg)
698 if (system && strcmp(call->class->system, system->name) != 0)
702 * We need to find out if all the events are set
703 * or if all events or cleared, or if we have
706 set |= (1 << !!(file->flags & FTRACE_EVENT_FL_ENABLED));
709 * If we have a mixture, no need to look further.
714 mutex_unlock(&event_mutex);
716 buf[0] = set_to_char[set];
719 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
725 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
728 struct ftrace_subsystem_dir *dir = filp->private_data;
729 struct event_subsystem *system = dir->subsystem;
730 const char *name = NULL;
734 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
738 ret = tracing_update_buffers();
742 if (val != 0 && val != 1)
746 * Opening of "enable" adds a ref count to system,
747 * so the name is safe to use.
752 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
766 FORMAT_FIELD_SEPERATOR = 2,
770 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
772 struct ftrace_event_call *call = m->private;
773 struct ftrace_event_field *field;
774 struct list_head *common_head = &ftrace_common_fields;
775 struct list_head *head = trace_get_fields(call);
779 switch ((unsigned long)v) {
781 if (unlikely(list_empty(common_head)))
784 field = list_entry(common_head->prev,
785 struct ftrace_event_field, link);
788 case FORMAT_FIELD_SEPERATOR:
789 if (unlikely(list_empty(head)))
792 field = list_entry(head->prev, struct ftrace_event_field, link);
795 case FORMAT_PRINTFMT:
801 if (field->link.prev == common_head)
802 return (void *)FORMAT_FIELD_SEPERATOR;
803 else if (field->link.prev == head)
804 return (void *)FORMAT_PRINTFMT;
806 field = list_entry(field->link.prev, struct ftrace_event_field, link);
811 static void *f_start(struct seq_file *m, loff_t *pos)
816 /* Start by showing the header */
818 return (void *)FORMAT_HEADER;
820 p = (void *)FORMAT_HEADER;
822 p = f_next(m, p, &l);
823 } while (p && l < *pos);
828 static int f_show(struct seq_file *m, void *v)
830 struct ftrace_event_call *call = m->private;
831 struct ftrace_event_field *field;
832 const char *array_descriptor;
834 switch ((unsigned long)v) {
836 seq_printf(m, "name: %s\n", call->name);
837 seq_printf(m, "ID: %d\n", call->event.type);
838 seq_printf(m, "format:\n");
841 case FORMAT_FIELD_SEPERATOR:
845 case FORMAT_PRINTFMT:
846 seq_printf(m, "\nprint fmt: %s\n",
854 * Smartly shows the array type(except dynamic array).
857 * If TYPE := TYPE[LEN], it is shown:
858 * field:TYPE VAR[LEN]
860 array_descriptor = strchr(field->type, '[');
862 if (!strncmp(field->type, "__data_loc", 10))
863 array_descriptor = NULL;
865 if (!array_descriptor)
866 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
867 field->type, field->name, field->offset,
868 field->size, !!field->is_signed);
870 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
871 (int)(array_descriptor - field->type),
872 field->type, field->name,
873 array_descriptor, field->offset,
874 field->size, !!field->is_signed);
879 static void f_stop(struct seq_file *m, void *p)
883 static const struct seq_operations trace_format_seq_ops = {
890 static int trace_format_open(struct inode *inode, struct file *file)
892 struct ftrace_event_call *call = inode->i_private;
896 ret = seq_open(file, &trace_format_seq_ops);
900 m = file->private_data;
907 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
909 struct ftrace_event_call *call = filp->private_data;
916 s = kmalloc(sizeof(*s), GFP_KERNEL);
921 trace_seq_printf(s, "%d\n", call->event.type);
923 r = simple_read_from_buffer(ubuf, cnt, ppos,
930 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
933 struct ftrace_event_call *call = filp->private_data;
940 s = kmalloc(sizeof(*s), GFP_KERNEL);
946 print_event_filter(call, s);
947 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
955 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
958 struct ftrace_event_call *call = filp->private_data;
962 if (cnt >= PAGE_SIZE)
965 buf = (char *)__get_free_page(GFP_TEMPORARY);
969 if (copy_from_user(buf, ubuf, cnt)) {
970 free_page((unsigned long) buf);
975 err = apply_event_filter(call, buf);
976 free_page((unsigned long) buf);
985 static LIST_HEAD(event_subsystems);
987 static int subsystem_open(struct inode *inode, struct file *filp)
989 struct event_subsystem *system = NULL;
990 struct ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */
991 struct trace_array *tr;
994 /* Make sure the system still exists */
995 mutex_lock(&event_mutex);
996 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
997 list_for_each_entry(dir, &tr->systems, list) {
998 if (dir == inode->i_private) {
999 /* Don't open systems with no events */
1000 if (dir->nr_events) {
1001 __get_system_dir(dir);
1002 system = dir->subsystem;
1009 mutex_unlock(&event_mutex);
1014 /* Some versions of gcc think dir can be uninitialized here */
1017 ret = tracing_open_generic(inode, filp);
1024 static int system_tr_open(struct inode *inode, struct file *filp)
1026 struct ftrace_subsystem_dir *dir;
1027 struct trace_array *tr = inode->i_private;
1030 /* Make a temporary dir that has no system but points to tr */
1031 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1037 ret = tracing_open_generic(inode, filp);
1041 filp->private_data = dir;
1046 static int subsystem_release(struct inode *inode, struct file *file)
1048 struct ftrace_subsystem_dir *dir = file->private_data;
1051 * If dir->subsystem is NULL, then this is a temporary
1052 * descriptor that was made for a trace_array to enable
1064 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1067 struct ftrace_subsystem_dir *dir = filp->private_data;
1068 struct event_subsystem *system = dir->subsystem;
1069 struct trace_seq *s;
1075 s = kmalloc(sizeof(*s), GFP_KERNEL);
1081 print_subsystem_event_filter(system, s);
1082 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1090 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1093 struct ftrace_subsystem_dir *dir = filp->private_data;
1097 if (cnt >= PAGE_SIZE)
1100 buf = (char *)__get_free_page(GFP_TEMPORARY);
1104 if (copy_from_user(buf, ubuf, cnt)) {
1105 free_page((unsigned long) buf);
1110 err = apply_subsystem_event_filter(dir, buf);
1111 free_page((unsigned long) buf);
1121 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1123 int (*func)(struct trace_seq *s) = filp->private_data;
1124 struct trace_seq *s;
1130 s = kmalloc(sizeof(*s), GFP_KERNEL);
1137 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1144 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1145 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1147 static const struct seq_operations show_event_seq_ops = {
1154 static const struct seq_operations show_set_event_seq_ops = {
1161 static const struct file_operations ftrace_avail_fops = {
1162 .open = ftrace_event_avail_open,
1164 .llseek = seq_lseek,
1165 .release = seq_release,
1168 static const struct file_operations ftrace_set_event_fops = {
1169 .open = ftrace_event_set_open,
1171 .write = ftrace_event_write,
1172 .llseek = seq_lseek,
1173 .release = seq_release,
1176 static const struct file_operations ftrace_enable_fops = {
1177 .open = tracing_open_generic,
1178 .read = event_enable_read,
1179 .write = event_enable_write,
1180 .llseek = default_llseek,
1183 static const struct file_operations ftrace_event_format_fops = {
1184 .open = trace_format_open,
1186 .llseek = seq_lseek,
1187 .release = seq_release,
1190 static const struct file_operations ftrace_event_id_fops = {
1191 .open = tracing_open_generic,
1192 .read = event_id_read,
1193 .llseek = default_llseek,
1196 static const struct file_operations ftrace_event_filter_fops = {
1197 .open = tracing_open_generic,
1198 .read = event_filter_read,
1199 .write = event_filter_write,
1200 .llseek = default_llseek,
1203 static const struct file_operations ftrace_subsystem_filter_fops = {
1204 .open = subsystem_open,
1205 .read = subsystem_filter_read,
1206 .write = subsystem_filter_write,
1207 .llseek = default_llseek,
1208 .release = subsystem_release,
1211 static const struct file_operations ftrace_system_enable_fops = {
1212 .open = subsystem_open,
1213 .read = system_enable_read,
1214 .write = system_enable_write,
1215 .llseek = default_llseek,
1216 .release = subsystem_release,
1219 static const struct file_operations ftrace_tr_enable_fops = {
1220 .open = system_tr_open,
1221 .read = system_enable_read,
1222 .write = system_enable_write,
1223 .llseek = default_llseek,
1224 .release = subsystem_release,
1227 static const struct file_operations ftrace_show_header_fops = {
1228 .open = tracing_open_generic,
1229 .read = show_header,
1230 .llseek = default_llseek,
1234 ftrace_event_open(struct inode *inode, struct file *file,
1235 const struct seq_operations *seq_ops)
1240 ret = seq_open(file, seq_ops);
1243 m = file->private_data;
1244 /* copy tr over to seq ops */
1245 m->private = inode->i_private;
1251 ftrace_event_avail_open(struct inode *inode, struct file *file)
1253 const struct seq_operations *seq_ops = &show_event_seq_ops;
1255 return ftrace_event_open(inode, file, seq_ops);
1259 ftrace_event_set_open(struct inode *inode, struct file *file)
1261 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1262 struct trace_array *tr = inode->i_private;
1264 if ((file->f_mode & FMODE_WRITE) &&
1265 (file->f_flags & O_TRUNC))
1266 ftrace_clear_events(tr);
1268 return ftrace_event_open(inode, file, seq_ops);
1271 static struct event_subsystem *
1272 create_new_subsystem(const char *name)
1274 struct event_subsystem *system;
1276 /* need to create new entry */
1277 system = kmalloc(sizeof(*system), GFP_KERNEL);
1281 system->ref_count = 1;
1282 system->name = name;
1284 system->filter = NULL;
1286 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1287 if (!system->filter)
1290 list_add(&system->list, &event_subsystems);
1299 static struct dentry *
1300 event_subsystem_dir(struct trace_array *tr, const char *name,
1301 struct ftrace_event_file *file, struct dentry *parent)
1303 struct ftrace_subsystem_dir *dir;
1304 struct event_subsystem *system;
1305 struct dentry *entry;
1307 /* First see if we did not already create this dir */
1308 list_for_each_entry(dir, &tr->systems, list) {
1309 system = dir->subsystem;
1310 if (strcmp(system->name, name) == 0) {
1317 /* Now see if the system itself exists. */
1318 list_for_each_entry(system, &event_subsystems, list) {
1319 if (strcmp(system->name, name) == 0)
1322 /* Reset system variable when not found */
1323 if (&system->list == &event_subsystems)
1326 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1331 system = create_new_subsystem(name);
1335 __get_system(system);
1337 dir->entry = debugfs_create_dir(name, parent);
1339 pr_warning("Failed to create system directory %s\n", name);
1340 __put_system(system);
1347 dir->subsystem = system;
1350 entry = debugfs_create_file("filter", 0644, dir->entry, dir,
1351 &ftrace_subsystem_filter_fops);
1353 kfree(system->filter);
1354 system->filter = NULL;
1355 pr_warning("Could not create debugfs '%s/filter' entry\n", name);
1358 trace_create_file("enable", 0644, dir->entry, dir,
1359 &ftrace_system_enable_fops);
1361 list_add(&dir->list, &tr->systems);
1368 /* Only print this message if failed on memory allocation */
1369 if (!dir || !system)
1370 pr_warning("No memory to create event subsystem %s\n",
1376 event_create_dir(struct dentry *parent,
1377 struct ftrace_event_file *file,
1378 const struct file_operations *id,
1379 const struct file_operations *enable,
1380 const struct file_operations *filter,
1381 const struct file_operations *format)
1383 struct ftrace_event_call *call = file->event_call;
1384 struct trace_array *tr = file->tr;
1385 struct list_head *head;
1386 struct dentry *d_events;
1390 * If the trace point header did not define TRACE_SYSTEM
1391 * then the system would be called "TRACE_SYSTEM".
1393 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1394 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1400 file->dir = debugfs_create_dir(call->name, d_events);
1402 pr_warning("Could not create debugfs '%s' directory\n",
1407 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1408 trace_create_file("enable", 0644, file->dir, file,
1411 #ifdef CONFIG_PERF_EVENTS
1412 if (call->event.type && call->class->reg)
1413 trace_create_file("id", 0444, file->dir, call,
1418 * Other events may have the same class. Only update
1419 * the fields if they are not already defined.
1421 head = trace_get_fields(call);
1422 if (list_empty(head)) {
1423 ret = call->class->define_fields(call);
1425 pr_warning("Could not initialize trace point"
1426 " events/%s\n", call->name);
1430 trace_create_file("filter", 0644, file->dir, call,
1433 trace_create_file("format", 0444, file->dir, call,
1439 static void remove_subsystem(struct ftrace_subsystem_dir *dir)
1444 if (!--dir->nr_events) {
1445 debugfs_remove_recursive(dir->entry);
1446 list_del(&dir->list);
1447 __put_system_dir(dir);
1451 static void remove_event_from_tracers(struct ftrace_event_call *call)
1453 struct ftrace_event_file *file;
1454 struct trace_array *tr;
1456 do_for_each_event_file_safe(tr, file) {
1458 if (file->event_call != call)
1461 list_del(&file->list);
1462 debugfs_remove_recursive(file->dir);
1463 remove_subsystem(file->system);
1464 kmem_cache_free(file_cachep, file);
1467 * The do_for_each_event_file_safe() is
1468 * a double loop. After finding the call for this
1469 * trace_array, we use break to jump to the next
1473 } while_for_each_event_file();
1476 static void event_remove(struct ftrace_event_call *call)
1478 struct trace_array *tr;
1479 struct ftrace_event_file *file;
1481 do_for_each_event_file(tr, file) {
1482 if (file->event_call != call)
1484 ftrace_event_enable_disable(file, 0);
1486 * The do_for_each_event_file() is
1487 * a double loop. After finding the call for this
1488 * trace_array, we use break to jump to the next
1492 } while_for_each_event_file();
1494 if (call->event.funcs)
1495 __unregister_ftrace_event(&call->event);
1496 remove_event_from_tracers(call);
1497 list_del(&call->list);
1500 static int event_init(struct ftrace_event_call *call)
1504 if (WARN_ON(!call->name))
1507 if (call->class->raw_init) {
1508 ret = call->class->raw_init(call);
1509 if (ret < 0 && ret != -ENOSYS)
1510 pr_warn("Could not initialize trace events/%s\n",
1518 __register_event(struct ftrace_event_call *call, struct module *mod)
1522 ret = event_init(call);
1526 list_add(&call->list, &ftrace_events);
1532 /* Add an event to a trace directory */
1534 __trace_add_new_event(struct ftrace_event_call *call,
1535 struct trace_array *tr,
1536 const struct file_operations *id,
1537 const struct file_operations *enable,
1538 const struct file_operations *filter,
1539 const struct file_operations *format)
1541 struct ftrace_event_file *file;
1543 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
1547 file->event_call = call;
1549 atomic_set(&file->sm_ref, 0);
1550 list_add(&file->list, &tr->events);
1552 return event_create_dir(tr->event_dir, file, id, enable, filter, format);
1556 * Just create a decriptor for early init. A descriptor is required
1557 * for enabling events at boot. We want to enable events before
1558 * the filesystem is initialized.
1561 __trace_early_add_new_event(struct ftrace_event_call *call,
1562 struct trace_array *tr)
1564 struct ftrace_event_file *file;
1566 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
1570 file->event_call = call;
1572 atomic_set(&file->sm_ref, 0);
1573 list_add(&file->list, &tr->events);
1578 struct ftrace_module_file_ops;
1579 static void __add_event_to_tracers(struct ftrace_event_call *call,
1580 struct ftrace_module_file_ops *file_ops);
1582 /* Add an additional event_call dynamically */
1583 int trace_add_event_call(struct ftrace_event_call *call)
1586 mutex_lock(&event_mutex);
1588 ret = __register_event(call, NULL);
1590 __add_event_to_tracers(call, NULL);
1592 mutex_unlock(&event_mutex);
1597 * Must be called under locking both of event_mutex and trace_event_sem.
1599 static void __trace_remove_event_call(struct ftrace_event_call *call)
1602 trace_destroy_fields(call);
1603 destroy_preds(call);
1606 /* Remove an event_call */
1607 void trace_remove_event_call(struct ftrace_event_call *call)
1609 mutex_lock(&event_mutex);
1610 down_write(&trace_event_sem);
1611 __trace_remove_event_call(call);
1612 up_write(&trace_event_sem);
1613 mutex_unlock(&event_mutex);
1616 #define for_each_event(event, start, end) \
1617 for (event = start; \
1618 (unsigned long)event < (unsigned long)end; \
1621 #ifdef CONFIG_MODULES
1623 static LIST_HEAD(ftrace_module_file_list);
1626 * Modules must own their file_operations to keep up with
1627 * reference counting.
1629 struct ftrace_module_file_ops {
1630 struct list_head list;
1632 struct file_operations id;
1633 struct file_operations enable;
1634 struct file_operations format;
1635 struct file_operations filter;
1638 static struct ftrace_module_file_ops *
1639 find_ftrace_file_ops(struct ftrace_module_file_ops *file_ops, struct module *mod)
1642 * As event_calls are added in groups by module,
1643 * when we find one file_ops, we don't need to search for
1644 * each call in that module, as the rest should be the
1645 * same. Only search for a new one if the last one did
1648 if (file_ops && mod == file_ops->mod)
1651 list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1652 if (file_ops->mod == mod)
1658 static struct ftrace_module_file_ops *
1659 trace_create_file_ops(struct module *mod)
1661 struct ftrace_module_file_ops *file_ops;
1664 * This is a bit of a PITA. To allow for correct reference
1665 * counting, modules must "own" their file_operations.
1666 * To do this, we allocate the file operations that will be
1667 * used in the event directory.
1670 file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1674 file_ops->mod = mod;
1676 file_ops->id = ftrace_event_id_fops;
1677 file_ops->id.owner = mod;
1679 file_ops->enable = ftrace_enable_fops;
1680 file_ops->enable.owner = mod;
1682 file_ops->filter = ftrace_event_filter_fops;
1683 file_ops->filter.owner = mod;
1685 file_ops->format = ftrace_event_format_fops;
1686 file_ops->format.owner = mod;
1688 list_add(&file_ops->list, &ftrace_module_file_list);
1693 static void trace_module_add_events(struct module *mod)
1695 struct ftrace_module_file_ops *file_ops = NULL;
1696 struct ftrace_event_call **call, **start, **end;
1698 start = mod->trace_events;
1699 end = mod->trace_events + mod->num_trace_events;
1704 file_ops = trace_create_file_ops(mod);
1708 for_each_event(call, start, end) {
1709 __register_event(*call, mod);
1710 __add_event_to_tracers(*call, file_ops);
1714 static void trace_module_remove_events(struct module *mod)
1716 struct ftrace_module_file_ops *file_ops;
1717 struct ftrace_event_call *call, *p;
1718 bool clear_trace = false;
1720 down_write(&trace_event_sem);
1721 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1722 if (call->mod == mod) {
1723 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
1725 __trace_remove_event_call(call);
1729 /* Now free the file_operations */
1730 list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1731 if (file_ops->mod == mod)
1734 if (&file_ops->list != &ftrace_module_file_list) {
1735 list_del(&file_ops->list);
1738 up_write(&trace_event_sem);
1741 * It is safest to reset the ring buffer if the module being unloaded
1742 * registered any events that were used. The only worry is if
1743 * a new module gets loaded, and takes on the same id as the events
1744 * of this module. When printing out the buffer, traced events left
1745 * over from this module may be passed to the new module events and
1746 * unexpected results may occur.
1749 tracing_reset_all_online_cpus();
1752 static int trace_module_notify(struct notifier_block *self,
1753 unsigned long val, void *data)
1755 struct module *mod = data;
1757 mutex_lock(&event_mutex);
1759 case MODULE_STATE_COMING:
1760 trace_module_add_events(mod);
1762 case MODULE_STATE_GOING:
1763 trace_module_remove_events(mod);
1766 mutex_unlock(&event_mutex);
1772 __trace_add_new_mod_event(struct ftrace_event_call *call,
1773 struct trace_array *tr,
1774 struct ftrace_module_file_ops *file_ops)
1776 return __trace_add_new_event(call, tr,
1777 &file_ops->id, &file_ops->enable,
1778 &file_ops->filter, &file_ops->format);
1782 static inline struct ftrace_module_file_ops *
1783 find_ftrace_file_ops(struct ftrace_module_file_ops *file_ops, struct module *mod)
1787 static inline int trace_module_notify(struct notifier_block *self,
1788 unsigned long val, void *data)
1793 __trace_add_new_mod_event(struct ftrace_event_call *call,
1794 struct trace_array *tr,
1795 struct ftrace_module_file_ops *file_ops)
1799 #endif /* CONFIG_MODULES */
1801 /* Create a new event directory structure for a trace directory. */
1803 __trace_add_event_dirs(struct trace_array *tr)
1805 struct ftrace_module_file_ops *file_ops = NULL;
1806 struct ftrace_event_call *call;
1809 list_for_each_entry(call, &ftrace_events, list) {
1812 * Directories for events by modules need to
1813 * keep module ref counts when opened (as we don't
1814 * want the module to disappear when reading one
1815 * of these files). The file_ops keep account of
1816 * the module ref count.
1818 file_ops = find_ftrace_file_ops(file_ops, call->mod);
1820 continue; /* Warn? */
1821 ret = __trace_add_new_mod_event(call, tr, file_ops);
1823 pr_warning("Could not create directory for event %s\n",
1827 ret = __trace_add_new_event(call, tr,
1828 &ftrace_event_id_fops,
1829 &ftrace_enable_fops,
1830 &ftrace_event_filter_fops,
1831 &ftrace_event_format_fops);
1833 pr_warning("Could not create directory for event %s\n",
1838 #ifdef CONFIG_DYNAMIC_FTRACE
1841 #define ENABLE_EVENT_STR "enable_event"
1842 #define DISABLE_EVENT_STR "disable_event"
1844 struct event_probe_data {
1845 struct ftrace_event_file *file;
1846 unsigned long count;
1851 static struct ftrace_event_file *
1852 find_event_file(struct trace_array *tr, const char *system, const char *event)
1854 struct ftrace_event_file *file;
1855 struct ftrace_event_call *call;
1857 list_for_each_entry(file, &tr->events, list) {
1859 call = file->event_call;
1861 if (!call->name || !call->class || !call->class->reg)
1864 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1867 if (strcmp(event, call->name) == 0 &&
1868 strcmp(system, call->class->system) == 0)
1875 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1877 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1878 struct event_probe_data *data = *pdata;
1884 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1886 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1890 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1892 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1893 struct event_probe_data *data = *pdata;
1901 /* Skip if the event is in a state we want to switch to */
1902 if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
1905 if (data->count != -1)
1908 event_enable_probe(ip, parent_ip, _data);
1912 event_enable_print(struct seq_file *m, unsigned long ip,
1913 struct ftrace_probe_ops *ops, void *_data)
1915 struct event_probe_data *data = _data;
1917 seq_printf(m, "%ps:", (void *)ip);
1919 seq_printf(m, "%s:%s:%s",
1920 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
1921 data->file->event_call->class->system,
1922 data->file->event_call->name);
1924 if (data->count == -1)
1925 seq_printf(m, ":unlimited\n");
1927 seq_printf(m, ":count=%ld\n", data->count);
1933 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
1936 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1937 struct event_probe_data *data = *pdata;
1944 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
1947 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1948 struct event_probe_data *data = *pdata;
1950 if (WARN_ON_ONCE(data->ref <= 0))
1955 /* Remove the SOFT_MODE flag */
1956 __ftrace_event_enable_disable(data->file, 0, 1);
1957 module_put(data->file->event_call->mod);
1963 static struct ftrace_probe_ops event_enable_probe_ops = {
1964 .func = event_enable_probe,
1965 .print = event_enable_print,
1966 .init = event_enable_init,
1967 .free = event_enable_free,
1970 static struct ftrace_probe_ops event_enable_count_probe_ops = {
1971 .func = event_enable_count_probe,
1972 .print = event_enable_print,
1973 .init = event_enable_init,
1974 .free = event_enable_free,
1977 static struct ftrace_probe_ops event_disable_probe_ops = {
1978 .func = event_enable_probe,
1979 .print = event_enable_print,
1980 .init = event_enable_init,
1981 .free = event_enable_free,
1984 static struct ftrace_probe_ops event_disable_count_probe_ops = {
1985 .func = event_enable_count_probe,
1986 .print = event_enable_print,
1987 .init = event_enable_init,
1988 .free = event_enable_free,
1992 event_enable_func(struct ftrace_hash *hash,
1993 char *glob, char *cmd, char *param, int enabled)
1995 struct trace_array *tr = top_trace_array();
1996 struct ftrace_event_file *file;
1997 struct ftrace_probe_ops *ops;
1998 struct event_probe_data *data;
2005 /* hash funcs only work with set_ftrace_filter */
2012 system = strsep(¶m, ":");
2016 event = strsep(¶m, ":");
2018 mutex_lock(&event_mutex);
2021 file = find_event_file(tr, system, event);
2025 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2028 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2030 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2032 if (glob[0] == '!') {
2033 unregister_ftrace_function_probe_func(glob+1, ops);
2039 data = kzalloc(sizeof(*data), GFP_KERNEL);
2043 data->enable = enable;
2050 number = strsep(¶m, ":");
2053 if (!strlen(number))
2057 * We use the callback data field (which is a pointer)
2060 ret = kstrtoul(number, 0, &data->count);
2065 /* Don't let event modules unload while probe registered */
2066 ret = try_module_get(file->event_call->mod);
2070 ret = __ftrace_event_enable_disable(file, 1, 1);
2073 ret = register_ftrace_function_probe(glob, ops, data);
2075 * The above returns on success the # of functions enabled,
2076 * but if it didn't find any functions it returns zero.
2077 * Consider no functions a failure too.
2084 /* Just return zero, not the number of enabled functions */
2087 mutex_unlock(&event_mutex);
2091 __ftrace_event_enable_disable(file, 0, 1);
2093 module_put(file->event_call->mod);
2099 static struct ftrace_func_command event_enable_cmd = {
2100 .name = ENABLE_EVENT_STR,
2101 .func = event_enable_func,
2104 static struct ftrace_func_command event_disable_cmd = {
2105 .name = DISABLE_EVENT_STR,
2106 .func = event_enable_func,
2109 static __init int register_event_cmds(void)
2113 ret = register_ftrace_command(&event_enable_cmd);
2114 if (WARN_ON(ret < 0))
2116 ret = register_ftrace_command(&event_disable_cmd);
2117 if (WARN_ON(ret < 0))
2118 unregister_ftrace_command(&event_enable_cmd);
2122 static inline int register_event_cmds(void) { return 0; }
2123 #endif /* CONFIG_DYNAMIC_FTRACE */
2126 * The top level array has already had its ftrace_event_file
2127 * descriptors created in order to allow for early events to
2128 * be recorded. This function is called after the debugfs has been
2129 * initialized, and we now have to create the files associated
2133 __trace_early_add_event_dirs(struct trace_array *tr)
2135 struct ftrace_event_file *file;
2139 list_for_each_entry(file, &tr->events, list) {
2140 ret = event_create_dir(tr->event_dir, file,
2141 &ftrace_event_id_fops,
2142 &ftrace_enable_fops,
2143 &ftrace_event_filter_fops,
2144 &ftrace_event_format_fops);
2146 pr_warning("Could not create directory for event %s\n",
2147 file->event_call->name);
2152 * For early boot up, the top trace array requires to have
2153 * a list of events that can be enabled. This must be done before
2154 * the filesystem is set up in order to allow events to be traced
2158 __trace_early_add_events(struct trace_array *tr)
2160 struct ftrace_event_call *call;
2163 list_for_each_entry(call, &ftrace_events, list) {
2164 /* Early boot up should not have any modules loaded */
2165 if (WARN_ON_ONCE(call->mod))
2168 ret = __trace_early_add_new_event(call, tr);
2170 pr_warning("Could not create early event %s\n",
2175 /* Remove the event directory structure for a trace directory. */
2177 __trace_remove_event_dirs(struct trace_array *tr)
2179 struct ftrace_event_file *file, *next;
2181 list_for_each_entry_safe(file, next, &tr->events, list) {
2182 list_del(&file->list);
2183 debugfs_remove_recursive(file->dir);
2184 remove_subsystem(file->system);
2185 kmem_cache_free(file_cachep, file);
2190 __add_event_to_tracers(struct ftrace_event_call *call,
2191 struct ftrace_module_file_ops *file_ops)
2193 struct trace_array *tr;
2195 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
2197 __trace_add_new_mod_event(call, tr, file_ops);
2199 __trace_add_new_event(call, tr,
2200 &ftrace_event_id_fops,
2201 &ftrace_enable_fops,
2202 &ftrace_event_filter_fops,
2203 &ftrace_event_format_fops);
2207 static struct notifier_block trace_module_nb = {
2208 .notifier_call = trace_module_notify,
2212 extern struct ftrace_event_call *__start_ftrace_events[];
2213 extern struct ftrace_event_call *__stop_ftrace_events[];
2215 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2217 static __init int setup_trace_event(char *str)
2219 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2220 ring_buffer_expanded = true;
2221 tracing_selftest_disabled = true;
2225 __setup("trace_event=", setup_trace_event);
2227 /* Expects to have event_mutex held when called */
2229 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2231 struct dentry *d_events;
2232 struct dentry *entry;
2234 entry = debugfs_create_file("set_event", 0644, parent,
2235 tr, &ftrace_set_event_fops);
2237 pr_warning("Could not create debugfs 'set_event' entry\n");
2241 d_events = debugfs_create_dir("events", parent);
2243 pr_warning("Could not create debugfs 'events' directory\n");
2247 /* ring buffer internal formats */
2248 trace_create_file("header_page", 0444, d_events,
2249 ring_buffer_print_page_header,
2250 &ftrace_show_header_fops);
2252 trace_create_file("header_event", 0444, d_events,
2253 ring_buffer_print_entry_header,
2254 &ftrace_show_header_fops);
2256 trace_create_file("enable", 0644, d_events,
2257 tr, &ftrace_tr_enable_fops);
2259 tr->event_dir = d_events;
2265 * event_trace_add_tracer - add a instance of a trace_array to events
2266 * @parent: The parent dentry to place the files/directories for events in
2267 * @tr: The trace array associated with these events
2269 * When a new instance is created, it needs to set up its events
2270 * directory, as well as other files associated with events. It also
2271 * creates the event hierachry in the @parent/events directory.
2273 * Returns 0 on success.
2275 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2279 mutex_lock(&event_mutex);
2281 ret = create_event_toplevel_files(parent, tr);
2285 down_write(&trace_event_sem);
2286 __trace_add_event_dirs(tr);
2287 up_write(&trace_event_sem);
2290 mutex_unlock(&event_mutex);
2296 * The top trace array already had its file descriptors created.
2297 * Now the files themselves need to be created.
2300 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2304 mutex_lock(&event_mutex);
2306 ret = create_event_toplevel_files(parent, tr);
2310 down_write(&trace_event_sem);
2311 __trace_early_add_event_dirs(tr);
2312 up_write(&trace_event_sem);
2315 mutex_unlock(&event_mutex);
2320 int event_trace_del_tracer(struct trace_array *tr)
2322 /* Disable any running events */
2323 __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
2325 mutex_lock(&event_mutex);
2327 down_write(&trace_event_sem);
2328 __trace_remove_event_dirs(tr);
2329 debugfs_remove_recursive(tr->event_dir);
2330 up_write(&trace_event_sem);
2332 tr->event_dir = NULL;
2334 mutex_unlock(&event_mutex);
2339 static __init int event_trace_memsetup(void)
2341 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
2342 file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC);
2346 static __init int event_trace_enable(void)
2348 struct trace_array *tr = top_trace_array();
2349 struct ftrace_event_call **iter, *call;
2350 char *buf = bootup_event_buf;
2354 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
2357 ret = event_init(call);
2359 list_add(&call->list, &ftrace_events);
2363 * We need the top trace array to have a working set of trace
2364 * points at early init, before the debug files and directories
2365 * are created. Create the file entries now, and attach them
2366 * to the actual file dentries later.
2368 __trace_early_add_events(tr);
2371 token = strsep(&buf, ",");
2378 ret = ftrace_set_clr_event(tr, token, 1);
2380 pr_warn("Failed to enable trace event: %s\n", token);
2383 trace_printk_start_comm();
2385 register_event_cmds();
2390 static __init int event_trace_init(void)
2392 struct trace_array *tr;
2393 struct dentry *d_tracer;
2394 struct dentry *entry;
2397 tr = top_trace_array();
2399 d_tracer = tracing_init_dentry();
2403 entry = debugfs_create_file("available_events", 0444, d_tracer,
2404 tr, &ftrace_avail_fops);
2406 pr_warning("Could not create debugfs "
2407 "'available_events' entry\n");
2409 if (trace_define_common_fields())
2410 pr_warning("tracing: Failed to allocate common fields");
2412 ret = early_event_add_tracer(d_tracer, tr);
2416 ret = register_module_notifier(&trace_module_nb);
2418 pr_warning("Failed to register trace events module notifier\n");
2422 early_initcall(event_trace_memsetup);
2423 core_initcall(event_trace_enable);
2424 fs_initcall(event_trace_init);
2426 #ifdef CONFIG_FTRACE_STARTUP_TEST
2428 static DEFINE_SPINLOCK(test_spinlock);
2429 static DEFINE_SPINLOCK(test_spinlock_irq);
2430 static DEFINE_MUTEX(test_mutex);
2432 static __init void test_work(struct work_struct *dummy)
2434 spin_lock(&test_spinlock);
2435 spin_lock_irq(&test_spinlock_irq);
2437 spin_unlock_irq(&test_spinlock_irq);
2438 spin_unlock(&test_spinlock);
2440 mutex_lock(&test_mutex);
2442 mutex_unlock(&test_mutex);
2445 static __init int event_test_thread(void *unused)
2449 test_malloc = kmalloc(1234, GFP_KERNEL);
2451 pr_info("failed to kmalloc\n");
2453 schedule_on_each_cpu(test_work);
2457 set_current_state(TASK_INTERRUPTIBLE);
2458 while (!kthread_should_stop())
2465 * Do various things that may trigger events.
2467 static __init void event_test_stuff(void)
2469 struct task_struct *test_thread;
2471 test_thread = kthread_run(event_test_thread, NULL, "test-events");
2473 kthread_stop(test_thread);
2477 * For every trace event defined, we will test each trace point separately,
2478 * and then by groups, and finally all trace points.
2480 static __init void event_trace_self_tests(void)
2482 struct ftrace_subsystem_dir *dir;
2483 struct ftrace_event_file *file;
2484 struct ftrace_event_call *call;
2485 struct event_subsystem *system;
2486 struct trace_array *tr;
2489 tr = top_trace_array();
2491 pr_info("Running tests on trace events:\n");
2493 list_for_each_entry(file, &tr->events, list) {
2495 call = file->event_call;
2497 /* Only test those that have a probe */
2498 if (!call->class || !call->class->probe)
2502 * Testing syscall events here is pretty useless, but
2503 * we still do it if configured. But this is time consuming.
2504 * What we really need is a user thread to perform the
2505 * syscalls as we test.
2507 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
2508 if (call->class->system &&
2509 strcmp(call->class->system, "syscalls") == 0)
2513 pr_info("Testing event %s: ", call->name);
2516 * If an event is already enabled, someone is using
2517 * it and the self test should not be on.
2519 if (file->flags & FTRACE_EVENT_FL_ENABLED) {
2520 pr_warning("Enabled event during self test!\n");
2525 ftrace_event_enable_disable(file, 1);
2527 ftrace_event_enable_disable(file, 0);
2532 /* Now test at the sub system level */
2534 pr_info("Running tests on trace event systems:\n");
2536 list_for_each_entry(dir, &tr->systems, list) {
2538 system = dir->subsystem;
2540 /* the ftrace system is special, skip it */
2541 if (strcmp(system->name, "ftrace") == 0)
2544 pr_info("Testing event system %s: ", system->name);
2546 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
2547 if (WARN_ON_ONCE(ret)) {
2548 pr_warning("error enabling system %s\n",
2555 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
2556 if (WARN_ON_ONCE(ret)) {
2557 pr_warning("error disabling system %s\n",
2565 /* Test with all events enabled */
2567 pr_info("Running tests on all trace events:\n");
2568 pr_info("Testing all events: ");
2570 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
2571 if (WARN_ON_ONCE(ret)) {
2572 pr_warning("error enabling all events\n");
2579 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
2580 if (WARN_ON_ONCE(ret)) {
2581 pr_warning("error disabling all events\n");
2588 #ifdef CONFIG_FUNCTION_TRACER
2590 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
2593 function_test_events_call(unsigned long ip, unsigned long parent_ip,
2594 struct ftrace_ops *op, struct pt_regs *pt_regs)
2596 struct ring_buffer_event *event;
2597 struct ring_buffer *buffer;
2598 struct ftrace_entry *entry;
2599 unsigned long flags;
2604 pc = preempt_count();
2605 preempt_disable_notrace();
2606 cpu = raw_smp_processor_id();
2607 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
2612 local_save_flags(flags);
2614 event = trace_current_buffer_lock_reserve(&buffer,
2615 TRACE_FN, sizeof(*entry),
2619 entry = ring_buffer_event_data(event);
2621 entry->parent_ip = parent_ip;
2623 trace_buffer_unlock_commit(buffer, event, flags, pc);
2626 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
2627 preempt_enable_notrace();
2630 static struct ftrace_ops trace_ops __initdata =
2632 .func = function_test_events_call,
2633 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
2636 static __init void event_trace_self_test_with_function(void)
2639 ret = register_ftrace_function(&trace_ops);
2640 if (WARN_ON(ret < 0)) {
2641 pr_info("Failed to enable function tracer for event tests\n");
2644 pr_info("Running tests again, along with the function tracer\n");
2645 event_trace_self_tests();
2646 unregister_ftrace_function(&trace_ops);
2649 static __init void event_trace_self_test_with_function(void)
2654 static __init int event_trace_self_tests_init(void)
2656 if (!tracing_selftest_disabled) {
2657 event_trace_self_tests();
2658 event_trace_self_test_with_function();
2664 late_initcall(event_trace_self_tests_init);