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 #define pr_fmt(fmt) fmt
13 #include <linux/workqueue.h>
14 #include <linux/spinlock.h>
15 #include <linux/kthread.h>
16 #include <linux/tracefs.h>
17 #include <linux/uaccess.h>
18 #include <linux/module.h>
19 #include <linux/ctype.h>
20 #include <linux/slab.h>
21 #include <linux/delay.h>
23 #include <asm/setup.h>
25 #include "trace_output.h"
28 #define TRACE_SYSTEM "TRACE_SYSTEM"
30 DEFINE_MUTEX(event_mutex);
32 LIST_HEAD(ftrace_events);
33 static LIST_HEAD(ftrace_common_fields);
35 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
37 static struct kmem_cache *field_cachep;
38 static struct kmem_cache *file_cachep;
40 #define SYSTEM_FL_FREE_NAME (1 << 31)
42 static inline int system_refcount(struct event_subsystem *system)
44 return system->ref_count & ~SYSTEM_FL_FREE_NAME;
47 static int system_refcount_inc(struct event_subsystem *system)
49 return (system->ref_count++) & ~SYSTEM_FL_FREE_NAME;
52 static int system_refcount_dec(struct event_subsystem *system)
54 return (--system->ref_count) & ~SYSTEM_FL_FREE_NAME;
57 /* Double loops, do not use break, only goto's work */
58 #define do_for_each_event_file(tr, file) \
59 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
60 list_for_each_entry(file, &tr->events, list)
62 #define do_for_each_event_file_safe(tr, file) \
63 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
64 struct ftrace_event_file *___n; \
65 list_for_each_entry_safe(file, ___n, &tr->events, list)
67 #define while_for_each_event_file() \
70 static struct list_head *
71 trace_get_fields(struct ftrace_event_call *event_call)
73 if (!event_call->class->get_fields)
74 return &event_call->class->fields;
75 return event_call->class->get_fields(event_call);
78 static struct ftrace_event_field *
79 __find_event_field(struct list_head *head, char *name)
81 struct ftrace_event_field *field;
83 list_for_each_entry(field, head, link) {
84 if (!strcmp(field->name, name))
91 struct ftrace_event_field *
92 trace_find_event_field(struct ftrace_event_call *call, char *name)
94 struct ftrace_event_field *field;
95 struct list_head *head;
97 field = __find_event_field(&ftrace_common_fields, name);
101 head = trace_get_fields(call);
102 return __find_event_field(head, name);
105 static int __trace_define_field(struct list_head *head, const char *type,
106 const char *name, int offset, int size,
107 int is_signed, int filter_type)
109 struct ftrace_event_field *field;
111 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
118 if (filter_type == FILTER_OTHER)
119 field->filter_type = filter_assign_type(type);
121 field->filter_type = filter_type;
123 field->offset = offset;
125 field->is_signed = is_signed;
127 list_add(&field->link, head);
132 int trace_define_field(struct ftrace_event_call *call, const char *type,
133 const char *name, int offset, int size, int is_signed,
136 struct list_head *head;
138 if (WARN_ON(!call->class))
141 head = trace_get_fields(call);
142 return __trace_define_field(head, type, name, offset, size,
143 is_signed, filter_type);
145 EXPORT_SYMBOL_GPL(trace_define_field);
147 #define __common_field(type, item) \
148 ret = __trace_define_field(&ftrace_common_fields, #type, \
150 offsetof(typeof(ent), item), \
152 is_signed_type(type), FILTER_OTHER); \
156 static int trace_define_common_fields(void)
159 struct trace_entry ent;
161 __common_field(unsigned short, type);
162 __common_field(unsigned char, flags);
163 __common_field(unsigned char, preempt_count);
164 __common_field(int, pid);
169 static void trace_destroy_fields(struct ftrace_event_call *call)
171 struct ftrace_event_field *field, *next;
172 struct list_head *head;
174 head = trace_get_fields(call);
175 list_for_each_entry_safe(field, next, head, link) {
176 list_del(&field->link);
177 kmem_cache_free(field_cachep, field);
181 int trace_event_raw_init(struct ftrace_event_call *call)
185 id = register_ftrace_event(&call->event);
191 EXPORT_SYMBOL_GPL(trace_event_raw_init);
193 void *ftrace_event_buffer_reserve(struct ftrace_event_buffer *fbuffer,
194 struct ftrace_event_file *ftrace_file,
197 struct ftrace_event_call *event_call = ftrace_file->event_call;
199 local_save_flags(fbuffer->flags);
200 fbuffer->pc = preempt_count();
201 fbuffer->ftrace_file = ftrace_file;
204 trace_event_buffer_lock_reserve(&fbuffer->buffer, ftrace_file,
205 event_call->event.type, len,
206 fbuffer->flags, fbuffer->pc);
210 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
211 return fbuffer->entry;
213 EXPORT_SYMBOL_GPL(ftrace_event_buffer_reserve);
215 static DEFINE_SPINLOCK(tracepoint_iter_lock);
217 static void output_printk(struct ftrace_event_buffer *fbuffer)
219 struct ftrace_event_call *event_call;
220 struct trace_event *event;
222 struct trace_iterator *iter = tracepoint_print_iter;
227 event_call = fbuffer->ftrace_file->event_call;
228 if (!event_call || !event_call->event.funcs ||
229 !event_call->event.funcs->trace)
232 event = &fbuffer->ftrace_file->event_call->event;
234 spin_lock_irqsave(&tracepoint_iter_lock, flags);
235 trace_seq_init(&iter->seq);
236 iter->ent = fbuffer->entry;
237 event_call->event.funcs->trace(iter, 0, event);
238 trace_seq_putc(&iter->seq, 0);
239 printk("%s", iter->seq.buffer);
241 spin_unlock_irqrestore(&tracepoint_iter_lock, flags);
244 void ftrace_event_buffer_commit(struct ftrace_event_buffer *fbuffer)
246 if (tracepoint_printk)
247 output_printk(fbuffer);
249 event_trigger_unlock_commit(fbuffer->ftrace_file, fbuffer->buffer,
250 fbuffer->event, fbuffer->entry,
251 fbuffer->flags, fbuffer->pc);
253 EXPORT_SYMBOL_GPL(ftrace_event_buffer_commit);
255 int ftrace_event_reg(struct ftrace_event_call *call,
256 enum trace_reg type, void *data)
258 struct ftrace_event_file *file = data;
260 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
262 case TRACE_REG_REGISTER:
263 return tracepoint_probe_register(call->tp,
266 case TRACE_REG_UNREGISTER:
267 tracepoint_probe_unregister(call->tp,
272 #ifdef CONFIG_PERF_EVENTS
273 case TRACE_REG_PERF_REGISTER:
274 return tracepoint_probe_register(call->tp,
275 call->class->perf_probe,
277 case TRACE_REG_PERF_UNREGISTER:
278 tracepoint_probe_unregister(call->tp,
279 call->class->perf_probe,
282 case TRACE_REG_PERF_OPEN:
283 case TRACE_REG_PERF_CLOSE:
284 case TRACE_REG_PERF_ADD:
285 case TRACE_REG_PERF_DEL:
291 EXPORT_SYMBOL_GPL(ftrace_event_reg);
293 void trace_event_enable_cmd_record(bool enable)
295 struct ftrace_event_file *file;
296 struct trace_array *tr;
298 mutex_lock(&event_mutex);
299 do_for_each_event_file(tr, file) {
301 if (!(file->flags & FTRACE_EVENT_FL_ENABLED))
305 tracing_start_cmdline_record();
306 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
308 tracing_stop_cmdline_record();
309 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
311 } while_for_each_event_file();
312 mutex_unlock(&event_mutex);
315 static int __ftrace_event_enable_disable(struct ftrace_event_file *file,
316 int enable, int soft_disable)
318 struct ftrace_event_call *call = file->event_call;
325 * When soft_disable is set and enable is cleared, the sm_ref
326 * reference counter is decremented. If it reaches 0, we want
327 * to clear the SOFT_DISABLED flag but leave the event in the
328 * state that it was. That is, if the event was enabled and
329 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
330 * is set we do not want the event to be enabled before we
333 * When soft_disable is not set but the SOFT_MODE flag is,
334 * we do nothing. Do not disable the tracepoint, otherwise
335 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
338 if (atomic_dec_return(&file->sm_ref) > 0)
340 disable = file->flags & FTRACE_EVENT_FL_SOFT_DISABLED;
341 clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
343 disable = !(file->flags & FTRACE_EVENT_FL_SOFT_MODE);
345 if (disable && (file->flags & FTRACE_EVENT_FL_ENABLED)) {
346 clear_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
347 if (file->flags & FTRACE_EVENT_FL_RECORDED_CMD) {
348 tracing_stop_cmdline_record();
349 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
351 call->class->reg(call, TRACE_REG_UNREGISTER, file);
353 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
354 if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
355 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
357 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
361 * When soft_disable is set and enable is set, we want to
362 * register the tracepoint for the event, but leave the event
363 * as is. That means, if the event was already enabled, we do
364 * nothing (but set SOFT_MODE). If the event is disabled, we
365 * set SOFT_DISABLED before enabling the event tracepoint, so
366 * it still seems to be disabled.
369 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
371 if (atomic_inc_return(&file->sm_ref) > 1)
373 set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
376 if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) {
378 /* Keep the event disabled, when going to SOFT_MODE. */
380 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
382 if (trace_flags & TRACE_ITER_RECORD_CMD) {
383 tracing_start_cmdline_record();
384 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
386 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
388 tracing_stop_cmdline_record();
389 pr_info("event trace: Could not enable event "
390 "%s\n", ftrace_event_name(call));
393 set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
395 /* WAS_ENABLED gets set but never cleared. */
396 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
404 int trace_event_enable_disable(struct ftrace_event_file *file,
405 int enable, int soft_disable)
407 return __ftrace_event_enable_disable(file, enable, soft_disable);
410 static int ftrace_event_enable_disable(struct ftrace_event_file *file,
413 return __ftrace_event_enable_disable(file, enable, 0);
416 static void ftrace_clear_events(struct trace_array *tr)
418 struct ftrace_event_file *file;
420 mutex_lock(&event_mutex);
421 list_for_each_entry(file, &tr->events, list) {
422 ftrace_event_enable_disable(file, 0);
424 mutex_unlock(&event_mutex);
427 static void __put_system(struct event_subsystem *system)
429 struct event_filter *filter = system->filter;
431 WARN_ON_ONCE(system_refcount(system) == 0);
432 if (system_refcount_dec(system))
435 list_del(&system->list);
438 kfree(filter->filter_string);
441 if (system->ref_count & SYSTEM_FL_FREE_NAME)
446 static void __get_system(struct event_subsystem *system)
448 WARN_ON_ONCE(system_refcount(system) == 0);
449 system_refcount_inc(system);
452 static void __get_system_dir(struct ftrace_subsystem_dir *dir)
454 WARN_ON_ONCE(dir->ref_count == 0);
456 __get_system(dir->subsystem);
459 static void __put_system_dir(struct ftrace_subsystem_dir *dir)
461 WARN_ON_ONCE(dir->ref_count == 0);
462 /* If the subsystem is about to be freed, the dir must be too */
463 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
465 __put_system(dir->subsystem);
466 if (!--dir->ref_count)
470 static void put_system(struct ftrace_subsystem_dir *dir)
472 mutex_lock(&event_mutex);
473 __put_system_dir(dir);
474 mutex_unlock(&event_mutex);
477 static void remove_subsystem(struct ftrace_subsystem_dir *dir)
482 if (!--dir->nr_events) {
483 tracefs_remove_recursive(dir->entry);
484 list_del(&dir->list);
485 __put_system_dir(dir);
489 static void remove_event_file_dir(struct ftrace_event_file *file)
491 struct dentry *dir = file->dir;
492 struct dentry *child;
495 spin_lock(&dir->d_lock); /* probably unneeded */
496 list_for_each_entry(child, &dir->d_subdirs, d_child) {
497 if (child->d_inode) /* probably unneeded */
498 child->d_inode->i_private = NULL;
500 spin_unlock(&dir->d_lock);
502 tracefs_remove_recursive(dir);
505 list_del(&file->list);
506 remove_subsystem(file->system);
507 free_event_filter(file->filter);
508 kmem_cache_free(file_cachep, file);
512 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
515 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
516 const char *sub, const char *event, int set)
518 struct ftrace_event_file *file;
519 struct ftrace_event_call *call;
523 list_for_each_entry(file, &tr->events, list) {
525 call = file->event_call;
526 name = ftrace_event_name(call);
528 if (!name || !call->class || !call->class->reg)
531 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
535 strcmp(match, name) != 0 &&
536 strcmp(match, call->class->system) != 0)
539 if (sub && strcmp(sub, call->class->system) != 0)
542 if (event && strcmp(event, name) != 0)
545 ftrace_event_enable_disable(file, set);
553 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
554 const char *sub, const char *event, int set)
558 mutex_lock(&event_mutex);
559 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
560 mutex_unlock(&event_mutex);
565 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
567 char *event = NULL, *sub = NULL, *match;
570 * The buf format can be <subsystem>:<event-name>
571 * *:<event-name> means any event by that name.
572 * :<event-name> is the same.
574 * <subsystem>:* means all events in that subsystem
575 * <subsystem>: means the same.
577 * <name> (no ':') means all events in a subsystem with
578 * the name <name> or any event that matches <name>
581 match = strsep(&buf, ":");
587 if (!strlen(sub) || strcmp(sub, "*") == 0)
589 if (!strlen(event) || strcmp(event, "*") == 0)
593 return __ftrace_set_clr_event(tr, match, sub, event, set);
597 * trace_set_clr_event - enable or disable an event
598 * @system: system name to match (NULL for any system)
599 * @event: event name to match (NULL for all events, within system)
600 * @set: 1 to enable, 0 to disable
602 * This is a way for other parts of the kernel to enable or disable
605 * Returns 0 on success, -EINVAL if the parameters do not match any
608 int trace_set_clr_event(const char *system, const char *event, int set)
610 struct trace_array *tr = top_trace_array();
615 return __ftrace_set_clr_event(tr, NULL, system, event, set);
617 EXPORT_SYMBOL_GPL(trace_set_clr_event);
619 /* 128 should be much more than enough */
620 #define EVENT_BUF_SIZE 127
623 ftrace_event_write(struct file *file, const char __user *ubuf,
624 size_t cnt, loff_t *ppos)
626 struct trace_parser parser;
627 struct seq_file *m = file->private_data;
628 struct trace_array *tr = m->private;
634 ret = tracing_update_buffers();
638 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
641 read = trace_get_user(&parser, ubuf, cnt, ppos);
643 if (read >= 0 && trace_parser_loaded((&parser))) {
646 if (*parser.buffer == '!')
649 parser.buffer[parser.idx] = 0;
651 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
659 trace_parser_put(&parser);
665 t_next(struct seq_file *m, void *v, loff_t *pos)
667 struct ftrace_event_file *file = v;
668 struct ftrace_event_call *call;
669 struct trace_array *tr = m->private;
673 list_for_each_entry_continue(file, &tr->events, list) {
674 call = file->event_call;
676 * The ftrace subsystem is for showing formats only.
677 * They can not be enabled or disabled via the event files.
679 if (call->class && call->class->reg)
686 static void *t_start(struct seq_file *m, loff_t *pos)
688 struct ftrace_event_file *file;
689 struct trace_array *tr = m->private;
692 mutex_lock(&event_mutex);
694 file = list_entry(&tr->events, struct ftrace_event_file, list);
695 for (l = 0; l <= *pos; ) {
696 file = t_next(m, file, &l);
704 s_next(struct seq_file *m, void *v, loff_t *pos)
706 struct ftrace_event_file *file = v;
707 struct trace_array *tr = m->private;
711 list_for_each_entry_continue(file, &tr->events, list) {
712 if (file->flags & FTRACE_EVENT_FL_ENABLED)
719 static void *s_start(struct seq_file *m, loff_t *pos)
721 struct ftrace_event_file *file;
722 struct trace_array *tr = m->private;
725 mutex_lock(&event_mutex);
727 file = list_entry(&tr->events, struct ftrace_event_file, list);
728 for (l = 0; l <= *pos; ) {
729 file = s_next(m, file, &l);
736 static int t_show(struct seq_file *m, void *v)
738 struct ftrace_event_file *file = v;
739 struct ftrace_event_call *call = file->event_call;
741 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
742 seq_printf(m, "%s:", call->class->system);
743 seq_printf(m, "%s\n", ftrace_event_name(call));
748 static void t_stop(struct seq_file *m, void *p)
750 mutex_unlock(&event_mutex);
754 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
757 struct ftrace_event_file *file;
761 mutex_lock(&event_mutex);
762 file = event_file_data(filp);
765 mutex_unlock(&event_mutex);
770 if (flags & FTRACE_EVENT_FL_ENABLED &&
771 !(flags & FTRACE_EVENT_FL_SOFT_DISABLED))
774 if (flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
775 flags & FTRACE_EVENT_FL_SOFT_MODE)
780 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
784 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
787 struct ftrace_event_file *file;
791 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
795 ret = tracing_update_buffers();
803 mutex_lock(&event_mutex);
804 file = event_file_data(filp);
806 ret = ftrace_event_enable_disable(file, val);
807 mutex_unlock(&event_mutex);
816 return ret ? ret : cnt;
820 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
823 const char set_to_char[4] = { '?', '0', '1', 'X' };
824 struct ftrace_subsystem_dir *dir = filp->private_data;
825 struct event_subsystem *system = dir->subsystem;
826 struct ftrace_event_call *call;
827 struct ftrace_event_file *file;
828 struct trace_array *tr = dir->tr;
833 mutex_lock(&event_mutex);
834 list_for_each_entry(file, &tr->events, list) {
835 call = file->event_call;
836 if (!ftrace_event_name(call) || !call->class || !call->class->reg)
839 if (system && strcmp(call->class->system, system->name) != 0)
843 * We need to find out if all the events are set
844 * or if all events or cleared, or if we have
847 set |= (1 << !!(file->flags & FTRACE_EVENT_FL_ENABLED));
850 * If we have a mixture, no need to look further.
855 mutex_unlock(&event_mutex);
857 buf[0] = set_to_char[set];
860 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
866 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
869 struct ftrace_subsystem_dir *dir = filp->private_data;
870 struct event_subsystem *system = dir->subsystem;
871 const char *name = NULL;
875 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
879 ret = tracing_update_buffers();
883 if (val != 0 && val != 1)
887 * Opening of "enable" adds a ref count to system,
888 * so the name is safe to use.
893 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
907 FORMAT_FIELD_SEPERATOR = 2,
911 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
913 struct ftrace_event_call *call = event_file_data(m->private);
914 struct list_head *common_head = &ftrace_common_fields;
915 struct list_head *head = trace_get_fields(call);
916 struct list_head *node = v;
920 switch ((unsigned long)v) {
925 case FORMAT_FIELD_SEPERATOR:
929 case FORMAT_PRINTFMT:
935 if (node == common_head)
936 return (void *)FORMAT_FIELD_SEPERATOR;
937 else if (node == head)
938 return (void *)FORMAT_PRINTFMT;
943 static int f_show(struct seq_file *m, void *v)
945 struct ftrace_event_call *call = event_file_data(m->private);
946 struct ftrace_event_field *field;
947 const char *array_descriptor;
949 switch ((unsigned long)v) {
951 seq_printf(m, "name: %s\n", ftrace_event_name(call));
952 seq_printf(m, "ID: %d\n", call->event.type);
953 seq_puts(m, "format:\n");
956 case FORMAT_FIELD_SEPERATOR:
960 case FORMAT_PRINTFMT:
961 seq_printf(m, "\nprint fmt: %s\n",
966 field = list_entry(v, struct ftrace_event_field, link);
968 * Smartly shows the array type(except dynamic array).
971 * If TYPE := TYPE[LEN], it is shown:
972 * field:TYPE VAR[LEN]
974 array_descriptor = strchr(field->type, '[');
976 if (!strncmp(field->type, "__data_loc", 10))
977 array_descriptor = NULL;
979 if (!array_descriptor)
980 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
981 field->type, field->name, field->offset,
982 field->size, !!field->is_signed);
984 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
985 (int)(array_descriptor - field->type),
986 field->type, field->name,
987 array_descriptor, field->offset,
988 field->size, !!field->is_signed);
993 static void *f_start(struct seq_file *m, loff_t *pos)
995 void *p = (void *)FORMAT_HEADER;
998 /* ->stop() is called even if ->start() fails */
999 mutex_lock(&event_mutex);
1000 if (!event_file_data(m->private))
1001 return ERR_PTR(-ENODEV);
1003 while (l < *pos && p)
1004 p = f_next(m, p, &l);
1009 static void f_stop(struct seq_file *m, void *p)
1011 mutex_unlock(&event_mutex);
1014 static const struct seq_operations trace_format_seq_ops = {
1021 static int trace_format_open(struct inode *inode, struct file *file)
1026 ret = seq_open(file, &trace_format_seq_ops);
1030 m = file->private_data;
1037 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1039 int id = (long)event_file_data(filp);
1049 len = sprintf(buf, "%d\n", id);
1051 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1055 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1058 struct ftrace_event_file *file;
1059 struct trace_seq *s;
1065 s = kmalloc(sizeof(*s), GFP_KERNEL);
1072 mutex_lock(&event_mutex);
1073 file = event_file_data(filp);
1075 print_event_filter(file, s);
1076 mutex_unlock(&event_mutex);
1079 r = simple_read_from_buffer(ubuf, cnt, ppos,
1080 s->buffer, trace_seq_used(s));
1088 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1091 struct ftrace_event_file *file;
1095 if (cnt >= PAGE_SIZE)
1098 buf = (char *)__get_free_page(GFP_TEMPORARY);
1102 if (copy_from_user(buf, ubuf, cnt)) {
1103 free_page((unsigned long) buf);
1108 mutex_lock(&event_mutex);
1109 file = event_file_data(filp);
1111 err = apply_event_filter(file, buf);
1112 mutex_unlock(&event_mutex);
1114 free_page((unsigned long) buf);
1123 static LIST_HEAD(event_subsystems);
1125 static int subsystem_open(struct inode *inode, struct file *filp)
1127 struct event_subsystem *system = NULL;
1128 struct ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1129 struct trace_array *tr;
1132 if (tracing_is_disabled())
1135 /* Make sure the system still exists */
1136 mutex_lock(&trace_types_lock);
1137 mutex_lock(&event_mutex);
1138 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1139 list_for_each_entry(dir, &tr->systems, list) {
1140 if (dir == inode->i_private) {
1141 /* Don't open systems with no events */
1142 if (dir->nr_events) {
1143 __get_system_dir(dir);
1144 system = dir->subsystem;
1151 mutex_unlock(&event_mutex);
1152 mutex_unlock(&trace_types_lock);
1157 /* Some versions of gcc think dir can be uninitialized here */
1160 /* Still need to increment the ref count of the system */
1161 if (trace_array_get(tr) < 0) {
1166 ret = tracing_open_generic(inode, filp);
1168 trace_array_put(tr);
1175 static int system_tr_open(struct inode *inode, struct file *filp)
1177 struct ftrace_subsystem_dir *dir;
1178 struct trace_array *tr = inode->i_private;
1181 if (tracing_is_disabled())
1184 if (trace_array_get(tr) < 0)
1187 /* Make a temporary dir that has no system but points to tr */
1188 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1190 trace_array_put(tr);
1196 ret = tracing_open_generic(inode, filp);
1198 trace_array_put(tr);
1203 filp->private_data = dir;
1208 static int subsystem_release(struct inode *inode, struct file *file)
1210 struct ftrace_subsystem_dir *dir = file->private_data;
1212 trace_array_put(dir->tr);
1215 * If dir->subsystem is NULL, then this is a temporary
1216 * descriptor that was made for a trace_array to enable
1228 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1231 struct ftrace_subsystem_dir *dir = filp->private_data;
1232 struct event_subsystem *system = dir->subsystem;
1233 struct trace_seq *s;
1239 s = kmalloc(sizeof(*s), GFP_KERNEL);
1245 print_subsystem_event_filter(system, s);
1246 r = simple_read_from_buffer(ubuf, cnt, ppos,
1247 s->buffer, trace_seq_used(s));
1255 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1258 struct ftrace_subsystem_dir *dir = filp->private_data;
1262 if (cnt >= PAGE_SIZE)
1265 buf = (char *)__get_free_page(GFP_TEMPORARY);
1269 if (copy_from_user(buf, ubuf, cnt)) {
1270 free_page((unsigned long) buf);
1275 err = apply_subsystem_event_filter(dir, buf);
1276 free_page((unsigned long) buf);
1286 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1288 int (*func)(struct trace_seq *s) = filp->private_data;
1289 struct trace_seq *s;
1295 s = kmalloc(sizeof(*s), GFP_KERNEL);
1302 r = simple_read_from_buffer(ubuf, cnt, ppos,
1303 s->buffer, trace_seq_used(s));
1310 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1311 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1312 static int ftrace_event_release(struct inode *inode, struct file *file);
1314 static const struct seq_operations show_event_seq_ops = {
1321 static const struct seq_operations show_set_event_seq_ops = {
1328 static const struct file_operations ftrace_avail_fops = {
1329 .open = ftrace_event_avail_open,
1331 .llseek = seq_lseek,
1332 .release = seq_release,
1335 static const struct file_operations ftrace_set_event_fops = {
1336 .open = ftrace_event_set_open,
1338 .write = ftrace_event_write,
1339 .llseek = seq_lseek,
1340 .release = ftrace_event_release,
1343 static const struct file_operations ftrace_enable_fops = {
1344 .open = tracing_open_generic,
1345 .read = event_enable_read,
1346 .write = event_enable_write,
1347 .llseek = default_llseek,
1350 static const struct file_operations ftrace_event_format_fops = {
1351 .open = trace_format_open,
1353 .llseek = seq_lseek,
1354 .release = seq_release,
1357 static const struct file_operations ftrace_event_id_fops = {
1358 .read = event_id_read,
1359 .llseek = default_llseek,
1362 static const struct file_operations ftrace_event_filter_fops = {
1363 .open = tracing_open_generic,
1364 .read = event_filter_read,
1365 .write = event_filter_write,
1366 .llseek = default_llseek,
1369 static const struct file_operations ftrace_subsystem_filter_fops = {
1370 .open = subsystem_open,
1371 .read = subsystem_filter_read,
1372 .write = subsystem_filter_write,
1373 .llseek = default_llseek,
1374 .release = subsystem_release,
1377 static const struct file_operations ftrace_system_enable_fops = {
1378 .open = subsystem_open,
1379 .read = system_enable_read,
1380 .write = system_enable_write,
1381 .llseek = default_llseek,
1382 .release = subsystem_release,
1385 static const struct file_operations ftrace_tr_enable_fops = {
1386 .open = system_tr_open,
1387 .read = system_enable_read,
1388 .write = system_enable_write,
1389 .llseek = default_llseek,
1390 .release = subsystem_release,
1393 static const struct file_operations ftrace_show_header_fops = {
1394 .open = tracing_open_generic,
1395 .read = show_header,
1396 .llseek = default_llseek,
1400 ftrace_event_open(struct inode *inode, struct file *file,
1401 const struct seq_operations *seq_ops)
1406 ret = seq_open(file, seq_ops);
1409 m = file->private_data;
1410 /* copy tr over to seq ops */
1411 m->private = inode->i_private;
1416 static int ftrace_event_release(struct inode *inode, struct file *file)
1418 struct trace_array *tr = inode->i_private;
1420 trace_array_put(tr);
1422 return seq_release(inode, file);
1426 ftrace_event_avail_open(struct inode *inode, struct file *file)
1428 const struct seq_operations *seq_ops = &show_event_seq_ops;
1430 return ftrace_event_open(inode, file, seq_ops);
1434 ftrace_event_set_open(struct inode *inode, struct file *file)
1436 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1437 struct trace_array *tr = inode->i_private;
1440 if (trace_array_get(tr) < 0)
1443 if ((file->f_mode & FMODE_WRITE) &&
1444 (file->f_flags & O_TRUNC))
1445 ftrace_clear_events(tr);
1447 ret = ftrace_event_open(inode, file, seq_ops);
1449 trace_array_put(tr);
1453 static struct event_subsystem *
1454 create_new_subsystem(const char *name)
1456 struct event_subsystem *system;
1458 /* need to create new entry */
1459 system = kmalloc(sizeof(*system), GFP_KERNEL);
1463 system->ref_count = 1;
1465 /* Only allocate if dynamic (kprobes and modules) */
1466 if (!core_kernel_data((unsigned long)name)) {
1467 system->ref_count |= SYSTEM_FL_FREE_NAME;
1468 system->name = kstrdup(name, GFP_KERNEL);
1472 system->name = name;
1474 system->filter = NULL;
1476 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1477 if (!system->filter)
1480 list_add(&system->list, &event_subsystems);
1485 if (system->ref_count & SYSTEM_FL_FREE_NAME)
1486 kfree(system->name);
1491 static struct dentry *
1492 event_subsystem_dir(struct trace_array *tr, const char *name,
1493 struct ftrace_event_file *file, struct dentry *parent)
1495 struct ftrace_subsystem_dir *dir;
1496 struct event_subsystem *system;
1497 struct dentry *entry;
1499 /* First see if we did not already create this dir */
1500 list_for_each_entry(dir, &tr->systems, list) {
1501 system = dir->subsystem;
1502 if (strcmp(system->name, name) == 0) {
1509 /* Now see if the system itself exists. */
1510 list_for_each_entry(system, &event_subsystems, list) {
1511 if (strcmp(system->name, name) == 0)
1514 /* Reset system variable when not found */
1515 if (&system->list == &event_subsystems)
1518 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1523 system = create_new_subsystem(name);
1527 __get_system(system);
1529 dir->entry = tracefs_create_dir(name, parent);
1531 pr_warn("Failed to create system directory %s\n", name);
1532 __put_system(system);
1539 dir->subsystem = system;
1542 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
1543 &ftrace_subsystem_filter_fops);
1545 kfree(system->filter);
1546 system->filter = NULL;
1547 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
1550 trace_create_file("enable", 0644, dir->entry, dir,
1551 &ftrace_system_enable_fops);
1553 list_add(&dir->list, &tr->systems);
1560 /* Only print this message if failed on memory allocation */
1561 if (!dir || !system)
1562 pr_warn("No memory to create event subsystem %s\n", name);
1567 event_create_dir(struct dentry *parent, struct ftrace_event_file *file)
1569 struct ftrace_event_call *call = file->event_call;
1570 struct trace_array *tr = file->tr;
1571 struct list_head *head;
1572 struct dentry *d_events;
1577 * If the trace point header did not define TRACE_SYSTEM
1578 * then the system would be called "TRACE_SYSTEM".
1580 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1581 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1587 name = ftrace_event_name(call);
1588 file->dir = tracefs_create_dir(name, d_events);
1590 pr_warn("Could not create tracefs '%s' directory\n", name);
1594 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1595 trace_create_file("enable", 0644, file->dir, file,
1596 &ftrace_enable_fops);
1598 #ifdef CONFIG_PERF_EVENTS
1599 if (call->event.type && call->class->reg)
1600 trace_create_file("id", 0444, file->dir,
1601 (void *)(long)call->event.type,
1602 &ftrace_event_id_fops);
1606 * Other events may have the same class. Only update
1607 * the fields if they are not already defined.
1609 head = trace_get_fields(call);
1610 if (list_empty(head)) {
1611 ret = call->class->define_fields(call);
1613 pr_warn("Could not initialize trace point events/%s\n",
1618 trace_create_file("filter", 0644, file->dir, file,
1619 &ftrace_event_filter_fops);
1621 trace_create_file("trigger", 0644, file->dir, file,
1622 &event_trigger_fops);
1624 trace_create_file("format", 0444, file->dir, call,
1625 &ftrace_event_format_fops);
1630 static void remove_event_from_tracers(struct ftrace_event_call *call)
1632 struct ftrace_event_file *file;
1633 struct trace_array *tr;
1635 do_for_each_event_file_safe(tr, file) {
1636 if (file->event_call != call)
1639 remove_event_file_dir(file);
1641 * The do_for_each_event_file_safe() is
1642 * a double loop. After finding the call for this
1643 * trace_array, we use break to jump to the next
1647 } while_for_each_event_file();
1650 static void event_remove(struct ftrace_event_call *call)
1652 struct trace_array *tr;
1653 struct ftrace_event_file *file;
1655 do_for_each_event_file(tr, file) {
1656 if (file->event_call != call)
1658 ftrace_event_enable_disable(file, 0);
1660 * The do_for_each_event_file() is
1661 * a double loop. After finding the call for this
1662 * trace_array, we use break to jump to the next
1666 } while_for_each_event_file();
1668 if (call->event.funcs)
1669 __unregister_ftrace_event(&call->event);
1670 remove_event_from_tracers(call);
1671 list_del(&call->list);
1674 static int event_init(struct ftrace_event_call *call)
1679 name = ftrace_event_name(call);
1683 if (call->class->raw_init) {
1684 ret = call->class->raw_init(call);
1685 if (ret < 0 && ret != -ENOSYS)
1686 pr_warn("Could not initialize trace events/%s\n", name);
1693 __register_event(struct ftrace_event_call *call, struct module *mod)
1697 ret = event_init(call);
1701 list_add(&call->list, &ftrace_events);
1707 static char *enum_replace(char *ptr, struct trace_enum_map *map, int len)
1712 /* Find the length of the enum value as a string */
1713 elen = snprintf(ptr, 0, "%ld", map->enum_value);
1714 /* Make sure there's enough room to replace the string with the value */
1718 snprintf(ptr, elen + 1, "%ld", map->enum_value);
1720 /* Get the rest of the string of ptr */
1721 rlen = strlen(ptr + len);
1722 memmove(ptr + elen, ptr + len, rlen);
1723 /* Make sure we end the new string */
1724 ptr[elen + rlen] = 0;
1729 static void update_event_printk(struct ftrace_event_call *call,
1730 struct trace_enum_map *map)
1734 int len = strlen(map->enum_string);
1736 for (ptr = call->print_fmt; *ptr; ptr++) {
1750 if (isdigit(*ptr)) {
1754 /* Check for alpha chars like ULL */
1755 } while (isalnum(*ptr));
1757 * A number must have some kind of delimiter after
1758 * it, and we can ignore that too.
1762 if (isalpha(*ptr) || *ptr == '_') {
1763 if (strncmp(map->enum_string, ptr, len) == 0 &&
1764 !isalnum(ptr[len]) && ptr[len] != '_') {
1765 ptr = enum_replace(ptr, map, len);
1766 /* Hmm, enum string smaller than value */
1767 if (WARN_ON_ONCE(!ptr))
1770 * No need to decrement here, as enum_replace()
1771 * returns the pointer to the character passed
1772 * the enum, and two enums can not be placed
1773 * back to back without something in between.
1774 * We can skip that something in between.
1781 } while (isalnum(*ptr) || *ptr == '_');
1783 * If what comes after this variable is a '.' or
1784 * '->' then we can continue to ignore that string.
1786 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
1787 ptr += *ptr == '.' ? 1 : 2;
1791 * Once again, we can skip the delimiter that came
1799 void trace_event_enum_update(struct trace_enum_map **map, int len)
1801 struct ftrace_event_call *call, *p;
1802 const char *last_system = NULL;
1806 down_write(&trace_event_sem);
1807 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1808 /* events are usually grouped together with systems */
1809 if (!last_system || call->class->system != last_system) {
1811 last_system = call->class->system;
1814 for (i = last_i; i < len; i++) {
1815 if (call->class->system == map[i]->system) {
1816 /* Save the first system if need be */
1819 update_event_printk(call, map[i]);
1823 up_write(&trace_event_sem);
1826 static struct ftrace_event_file *
1827 trace_create_new_event(struct ftrace_event_call *call,
1828 struct trace_array *tr)
1830 struct ftrace_event_file *file;
1832 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
1836 file->event_call = call;
1838 atomic_set(&file->sm_ref, 0);
1839 atomic_set(&file->tm_ref, 0);
1840 INIT_LIST_HEAD(&file->triggers);
1841 list_add(&file->list, &tr->events);
1846 /* Add an event to a trace directory */
1848 __trace_add_new_event(struct ftrace_event_call *call, struct trace_array *tr)
1850 struct ftrace_event_file *file;
1852 file = trace_create_new_event(call, tr);
1856 return event_create_dir(tr->event_dir, file);
1860 * Just create a decriptor for early init. A descriptor is required
1861 * for enabling events at boot. We want to enable events before
1862 * the filesystem is initialized.
1865 __trace_early_add_new_event(struct ftrace_event_call *call,
1866 struct trace_array *tr)
1868 struct ftrace_event_file *file;
1870 file = trace_create_new_event(call, tr);
1877 struct ftrace_module_file_ops;
1878 static void __add_event_to_tracers(struct ftrace_event_call *call);
1880 /* Add an additional event_call dynamically */
1881 int trace_add_event_call(struct ftrace_event_call *call)
1884 mutex_lock(&trace_types_lock);
1885 mutex_lock(&event_mutex);
1887 ret = __register_event(call, NULL);
1889 __add_event_to_tracers(call);
1891 mutex_unlock(&event_mutex);
1892 mutex_unlock(&trace_types_lock);
1897 * Must be called under locking of trace_types_lock, event_mutex and
1900 static void __trace_remove_event_call(struct ftrace_event_call *call)
1903 trace_destroy_fields(call);
1904 free_event_filter(call->filter);
1905 call->filter = NULL;
1908 static int probe_remove_event_call(struct ftrace_event_call *call)
1910 struct trace_array *tr;
1911 struct ftrace_event_file *file;
1913 #ifdef CONFIG_PERF_EVENTS
1914 if (call->perf_refcount)
1917 do_for_each_event_file(tr, file) {
1918 if (file->event_call != call)
1921 * We can't rely on ftrace_event_enable_disable(enable => 0)
1922 * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
1923 * TRACE_REG_UNREGISTER.
1925 if (file->flags & FTRACE_EVENT_FL_ENABLED)
1928 * The do_for_each_event_file_safe() is
1929 * a double loop. After finding the call for this
1930 * trace_array, we use break to jump to the next
1934 } while_for_each_event_file();
1936 __trace_remove_event_call(call);
1941 /* Remove an event_call */
1942 int trace_remove_event_call(struct ftrace_event_call *call)
1946 mutex_lock(&trace_types_lock);
1947 mutex_lock(&event_mutex);
1948 down_write(&trace_event_sem);
1949 ret = probe_remove_event_call(call);
1950 up_write(&trace_event_sem);
1951 mutex_unlock(&event_mutex);
1952 mutex_unlock(&trace_types_lock);
1957 #define for_each_event(event, start, end) \
1958 for (event = start; \
1959 (unsigned long)event < (unsigned long)end; \
1962 #ifdef CONFIG_MODULES
1964 static void trace_module_add_events(struct module *mod)
1966 struct ftrace_event_call **call, **start, **end;
1968 if (!mod->num_trace_events)
1971 /* Don't add infrastructure for mods without tracepoints */
1972 if (trace_module_has_bad_taint(mod)) {
1973 pr_err("%s: module has bad taint, not creating trace events\n",
1978 start = mod->trace_events;
1979 end = mod->trace_events + mod->num_trace_events;
1981 for_each_event(call, start, end) {
1982 __register_event(*call, mod);
1983 __add_event_to_tracers(*call);
1987 static void trace_module_remove_events(struct module *mod)
1989 struct ftrace_event_call *call, *p;
1990 bool clear_trace = false;
1992 down_write(&trace_event_sem);
1993 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1994 if (call->mod == mod) {
1995 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
1997 __trace_remove_event_call(call);
2000 up_write(&trace_event_sem);
2003 * It is safest to reset the ring buffer if the module being unloaded
2004 * registered any events that were used. The only worry is if
2005 * a new module gets loaded, and takes on the same id as the events
2006 * of this module. When printing out the buffer, traced events left
2007 * over from this module may be passed to the new module events and
2008 * unexpected results may occur.
2011 tracing_reset_all_online_cpus();
2014 static int trace_module_notify(struct notifier_block *self,
2015 unsigned long val, void *data)
2017 struct module *mod = data;
2019 mutex_lock(&trace_types_lock);
2020 mutex_lock(&event_mutex);
2022 case MODULE_STATE_COMING:
2023 trace_module_add_events(mod);
2025 case MODULE_STATE_GOING:
2026 trace_module_remove_events(mod);
2029 mutex_unlock(&event_mutex);
2030 mutex_unlock(&trace_types_lock);
2035 static struct notifier_block trace_module_nb = {
2036 .notifier_call = trace_module_notify,
2037 .priority = 1, /* higher than trace.c module notify */
2039 #endif /* CONFIG_MODULES */
2041 /* Create a new event directory structure for a trace directory. */
2043 __trace_add_event_dirs(struct trace_array *tr)
2045 struct ftrace_event_call *call;
2048 list_for_each_entry(call, &ftrace_events, list) {
2049 ret = __trace_add_new_event(call, tr);
2051 pr_warn("Could not create directory for event %s\n",
2052 ftrace_event_name(call));
2056 struct ftrace_event_file *
2057 find_event_file(struct trace_array *tr, const char *system, const char *event)
2059 struct ftrace_event_file *file;
2060 struct ftrace_event_call *call;
2063 list_for_each_entry(file, &tr->events, list) {
2065 call = file->event_call;
2066 name = ftrace_event_name(call);
2068 if (!name || !call->class || !call->class->reg)
2071 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2074 if (strcmp(event, name) == 0 &&
2075 strcmp(system, call->class->system) == 0)
2081 #ifdef CONFIG_DYNAMIC_FTRACE
2084 #define ENABLE_EVENT_STR "enable_event"
2085 #define DISABLE_EVENT_STR "disable_event"
2087 struct event_probe_data {
2088 struct ftrace_event_file *file;
2089 unsigned long count;
2095 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2097 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2098 struct event_probe_data *data = *pdata;
2104 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
2106 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
2110 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2112 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2113 struct event_probe_data *data = *pdata;
2121 /* Skip if the event is in a state we want to switch to */
2122 if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
2125 if (data->count != -1)
2128 event_enable_probe(ip, parent_ip, _data);
2132 event_enable_print(struct seq_file *m, unsigned long ip,
2133 struct ftrace_probe_ops *ops, void *_data)
2135 struct event_probe_data *data = _data;
2137 seq_printf(m, "%ps:", (void *)ip);
2139 seq_printf(m, "%s:%s:%s",
2140 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2141 data->file->event_call->class->system,
2142 ftrace_event_name(data->file->event_call));
2144 if (data->count == -1)
2145 seq_puts(m, ":unlimited\n");
2147 seq_printf(m, ":count=%ld\n", data->count);
2153 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
2156 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2157 struct event_probe_data *data = *pdata;
2164 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
2167 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2168 struct event_probe_data *data = *pdata;
2170 if (WARN_ON_ONCE(data->ref <= 0))
2175 /* Remove the SOFT_MODE flag */
2176 __ftrace_event_enable_disable(data->file, 0, 1);
2177 module_put(data->file->event_call->mod);
2183 static struct ftrace_probe_ops event_enable_probe_ops = {
2184 .func = event_enable_probe,
2185 .print = event_enable_print,
2186 .init = event_enable_init,
2187 .free = event_enable_free,
2190 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2191 .func = event_enable_count_probe,
2192 .print = event_enable_print,
2193 .init = event_enable_init,
2194 .free = event_enable_free,
2197 static struct ftrace_probe_ops event_disable_probe_ops = {
2198 .func = event_enable_probe,
2199 .print = event_enable_print,
2200 .init = event_enable_init,
2201 .free = event_enable_free,
2204 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2205 .func = event_enable_count_probe,
2206 .print = event_enable_print,
2207 .init = event_enable_init,
2208 .free = event_enable_free,
2212 event_enable_func(struct ftrace_hash *hash,
2213 char *glob, char *cmd, char *param, int enabled)
2215 struct trace_array *tr = top_trace_array();
2216 struct ftrace_event_file *file;
2217 struct ftrace_probe_ops *ops;
2218 struct event_probe_data *data;
2228 /* hash funcs only work with set_ftrace_filter */
2229 if (!enabled || !param)
2232 system = strsep(¶m, ":");
2236 event = strsep(¶m, ":");
2238 mutex_lock(&event_mutex);
2241 file = find_event_file(tr, system, event);
2245 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2248 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2250 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2252 if (glob[0] == '!') {
2253 unregister_ftrace_function_probe_func(glob+1, ops);
2259 data = kzalloc(sizeof(*data), GFP_KERNEL);
2263 data->enable = enable;
2270 number = strsep(¶m, ":");
2273 if (!strlen(number))
2277 * We use the callback data field (which is a pointer)
2280 ret = kstrtoul(number, 0, &data->count);
2285 /* Don't let event modules unload while probe registered */
2286 ret = try_module_get(file->event_call->mod);
2292 ret = __ftrace_event_enable_disable(file, 1, 1);
2295 ret = register_ftrace_function_probe(glob, ops, data);
2297 * The above returns on success the # of functions enabled,
2298 * but if it didn't find any functions it returns zero.
2299 * Consider no functions a failure too.
2306 /* Just return zero, not the number of enabled functions */
2309 mutex_unlock(&event_mutex);
2313 __ftrace_event_enable_disable(file, 0, 1);
2315 module_put(file->event_call->mod);
2321 static struct ftrace_func_command event_enable_cmd = {
2322 .name = ENABLE_EVENT_STR,
2323 .func = event_enable_func,
2326 static struct ftrace_func_command event_disable_cmd = {
2327 .name = DISABLE_EVENT_STR,
2328 .func = event_enable_func,
2331 static __init int register_event_cmds(void)
2335 ret = register_ftrace_command(&event_enable_cmd);
2336 if (WARN_ON(ret < 0))
2338 ret = register_ftrace_command(&event_disable_cmd);
2339 if (WARN_ON(ret < 0))
2340 unregister_ftrace_command(&event_enable_cmd);
2344 static inline int register_event_cmds(void) { return 0; }
2345 #endif /* CONFIG_DYNAMIC_FTRACE */
2348 * The top level array has already had its ftrace_event_file
2349 * descriptors created in order to allow for early events to
2350 * be recorded. This function is called after the tracefs has been
2351 * initialized, and we now have to create the files associated
2355 __trace_early_add_event_dirs(struct trace_array *tr)
2357 struct ftrace_event_file *file;
2361 list_for_each_entry(file, &tr->events, list) {
2362 ret = event_create_dir(tr->event_dir, file);
2364 pr_warn("Could not create directory for event %s\n",
2365 ftrace_event_name(file->event_call));
2370 * For early boot up, the top trace array requires to have
2371 * a list of events that can be enabled. This must be done before
2372 * the filesystem is set up in order to allow events to be traced
2376 __trace_early_add_events(struct trace_array *tr)
2378 struct ftrace_event_call *call;
2381 list_for_each_entry(call, &ftrace_events, list) {
2382 /* Early boot up should not have any modules loaded */
2383 if (WARN_ON_ONCE(call->mod))
2386 ret = __trace_early_add_new_event(call, tr);
2388 pr_warn("Could not create early event %s\n",
2389 ftrace_event_name(call));
2393 /* Remove the event directory structure for a trace directory. */
2395 __trace_remove_event_dirs(struct trace_array *tr)
2397 struct ftrace_event_file *file, *next;
2399 list_for_each_entry_safe(file, next, &tr->events, list)
2400 remove_event_file_dir(file);
2403 static void __add_event_to_tracers(struct ftrace_event_call *call)
2405 struct trace_array *tr;
2407 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2408 __trace_add_new_event(call, tr);
2411 extern struct ftrace_event_call *__start_ftrace_events[];
2412 extern struct ftrace_event_call *__stop_ftrace_events[];
2414 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2416 static __init int setup_trace_event(char *str)
2418 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2419 ring_buffer_expanded = true;
2420 tracing_selftest_disabled = true;
2424 __setup("trace_event=", setup_trace_event);
2426 /* Expects to have event_mutex held when called */
2428 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2430 struct dentry *d_events;
2431 struct dentry *entry;
2433 entry = tracefs_create_file("set_event", 0644, parent,
2434 tr, &ftrace_set_event_fops);
2436 pr_warn("Could not create tracefs 'set_event' entry\n");
2440 d_events = tracefs_create_dir("events", parent);
2442 pr_warn("Could not create tracefs 'events' directory\n");
2446 /* ring buffer internal formats */
2447 trace_create_file("header_page", 0444, d_events,
2448 ring_buffer_print_page_header,
2449 &ftrace_show_header_fops);
2451 trace_create_file("header_event", 0444, d_events,
2452 ring_buffer_print_entry_header,
2453 &ftrace_show_header_fops);
2455 trace_create_file("enable", 0644, d_events,
2456 tr, &ftrace_tr_enable_fops);
2458 tr->event_dir = d_events;
2464 * event_trace_add_tracer - add a instance of a trace_array to events
2465 * @parent: The parent dentry to place the files/directories for events in
2466 * @tr: The trace array associated with these events
2468 * When a new instance is created, it needs to set up its events
2469 * directory, as well as other files associated with events. It also
2470 * creates the event hierachry in the @parent/events directory.
2472 * Returns 0 on success.
2474 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2478 mutex_lock(&event_mutex);
2480 ret = create_event_toplevel_files(parent, tr);
2484 down_write(&trace_event_sem);
2485 __trace_add_event_dirs(tr);
2486 up_write(&trace_event_sem);
2489 mutex_unlock(&event_mutex);
2495 * The top trace array already had its file descriptors created.
2496 * Now the files themselves need to be created.
2499 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2503 mutex_lock(&event_mutex);
2505 ret = create_event_toplevel_files(parent, tr);
2509 down_write(&trace_event_sem);
2510 __trace_early_add_event_dirs(tr);
2511 up_write(&trace_event_sem);
2514 mutex_unlock(&event_mutex);
2519 int event_trace_del_tracer(struct trace_array *tr)
2521 mutex_lock(&event_mutex);
2523 /* Disable any event triggers and associated soft-disabled events */
2524 clear_event_triggers(tr);
2526 /* Disable any running events */
2527 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
2529 /* Access to events are within rcu_read_lock_sched() */
2530 synchronize_sched();
2532 down_write(&trace_event_sem);
2533 __trace_remove_event_dirs(tr);
2534 tracefs_remove_recursive(tr->event_dir);
2535 up_write(&trace_event_sem);
2537 tr->event_dir = NULL;
2539 mutex_unlock(&event_mutex);
2544 static __init int event_trace_memsetup(void)
2546 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
2547 file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC);
2552 early_enable_events(struct trace_array *tr, bool disable_first)
2554 char *buf = bootup_event_buf;
2559 token = strsep(&buf, ",");
2566 /* Restarting syscalls requires that we stop them first */
2568 ftrace_set_clr_event(tr, token, 0);
2570 ret = ftrace_set_clr_event(tr, token, 1);
2572 pr_warn("Failed to enable trace event: %s\n", token);
2574 /* Put back the comma to allow this to be called again */
2580 static __init int event_trace_enable(void)
2582 struct trace_array *tr = top_trace_array();
2583 struct ftrace_event_call **iter, *call;
2589 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
2592 ret = event_init(call);
2594 list_add(&call->list, &ftrace_events);
2598 * We need the top trace array to have a working set of trace
2599 * points at early init, before the debug files and directories
2600 * are created. Create the file entries now, and attach them
2601 * to the actual file dentries later.
2603 __trace_early_add_events(tr);
2605 early_enable_events(tr, false);
2607 trace_printk_start_comm();
2609 register_event_cmds();
2611 register_trigger_cmds();
2617 * event_trace_enable() is called from trace_event_init() first to
2618 * initialize events and perhaps start any events that are on the
2619 * command line. Unfortunately, there are some events that will not
2620 * start this early, like the system call tracepoints that need
2621 * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
2622 * is called before pid 1 starts, and this flag is never set, making
2623 * the syscall tracepoint never get reached, but the event is enabled
2624 * regardless (and not doing anything).
2626 static __init int event_trace_enable_again(void)
2628 struct trace_array *tr;
2630 tr = top_trace_array();
2634 early_enable_events(tr, true);
2639 early_initcall(event_trace_enable_again);
2641 static __init int event_trace_init(void)
2643 struct trace_array *tr;
2644 struct dentry *d_tracer;
2645 struct dentry *entry;
2648 tr = top_trace_array();
2652 d_tracer = tracing_init_dentry();
2653 if (IS_ERR(d_tracer))
2656 entry = tracefs_create_file("available_events", 0444, d_tracer,
2657 tr, &ftrace_avail_fops);
2659 pr_warn("Could not create tracefs 'available_events' entry\n");
2661 if (trace_define_common_fields())
2662 pr_warn("tracing: Failed to allocate common fields");
2664 ret = early_event_add_tracer(d_tracer, tr);
2668 #ifdef CONFIG_MODULES
2669 ret = register_module_notifier(&trace_module_nb);
2671 pr_warn("Failed to register trace events module notifier\n");
2676 void __init trace_event_init(void)
2678 event_trace_memsetup();
2679 init_ftrace_syscalls();
2680 event_trace_enable();
2683 fs_initcall(event_trace_init);
2685 #ifdef CONFIG_FTRACE_STARTUP_TEST
2687 static DEFINE_SPINLOCK(test_spinlock);
2688 static DEFINE_SPINLOCK(test_spinlock_irq);
2689 static DEFINE_MUTEX(test_mutex);
2691 static __init void test_work(struct work_struct *dummy)
2693 spin_lock(&test_spinlock);
2694 spin_lock_irq(&test_spinlock_irq);
2696 spin_unlock_irq(&test_spinlock_irq);
2697 spin_unlock(&test_spinlock);
2699 mutex_lock(&test_mutex);
2701 mutex_unlock(&test_mutex);
2704 static __init int event_test_thread(void *unused)
2708 test_malloc = kmalloc(1234, GFP_KERNEL);
2710 pr_info("failed to kmalloc\n");
2712 schedule_on_each_cpu(test_work);
2716 set_current_state(TASK_INTERRUPTIBLE);
2717 while (!kthread_should_stop()) {
2719 set_current_state(TASK_INTERRUPTIBLE);
2721 __set_current_state(TASK_RUNNING);
2727 * Do various things that may trigger events.
2729 static __init void event_test_stuff(void)
2731 struct task_struct *test_thread;
2733 test_thread = kthread_run(event_test_thread, NULL, "test-events");
2735 kthread_stop(test_thread);
2739 * For every trace event defined, we will test each trace point separately,
2740 * and then by groups, and finally all trace points.
2742 static __init void event_trace_self_tests(void)
2744 struct ftrace_subsystem_dir *dir;
2745 struct ftrace_event_file *file;
2746 struct ftrace_event_call *call;
2747 struct event_subsystem *system;
2748 struct trace_array *tr;
2751 tr = top_trace_array();
2755 pr_info("Running tests on trace events:\n");
2757 list_for_each_entry(file, &tr->events, list) {
2759 call = file->event_call;
2761 /* Only test those that have a probe */
2762 if (!call->class || !call->class->probe)
2766 * Testing syscall events here is pretty useless, but
2767 * we still do it if configured. But this is time consuming.
2768 * What we really need is a user thread to perform the
2769 * syscalls as we test.
2771 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
2772 if (call->class->system &&
2773 strcmp(call->class->system, "syscalls") == 0)
2777 pr_info("Testing event %s: ", ftrace_event_name(call));
2780 * If an event is already enabled, someone is using
2781 * it and the self test should not be on.
2783 if (file->flags & FTRACE_EVENT_FL_ENABLED) {
2784 pr_warn("Enabled event during self test!\n");
2789 ftrace_event_enable_disable(file, 1);
2791 ftrace_event_enable_disable(file, 0);
2796 /* Now test at the sub system level */
2798 pr_info("Running tests on trace event systems:\n");
2800 list_for_each_entry(dir, &tr->systems, list) {
2802 system = dir->subsystem;
2804 /* the ftrace system is special, skip it */
2805 if (strcmp(system->name, "ftrace") == 0)
2808 pr_info("Testing event system %s: ", system->name);
2810 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
2811 if (WARN_ON_ONCE(ret)) {
2812 pr_warn("error enabling system %s\n",
2819 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
2820 if (WARN_ON_ONCE(ret)) {
2821 pr_warn("error disabling system %s\n",
2829 /* Test with all events enabled */
2831 pr_info("Running tests on all trace events:\n");
2832 pr_info("Testing all events: ");
2834 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
2835 if (WARN_ON_ONCE(ret)) {
2836 pr_warn("error enabling all events\n");
2843 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
2844 if (WARN_ON_ONCE(ret)) {
2845 pr_warn("error disabling all events\n");
2852 #ifdef CONFIG_FUNCTION_TRACER
2854 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
2857 function_test_events_call(unsigned long ip, unsigned long parent_ip,
2858 struct ftrace_ops *op, struct pt_regs *pt_regs)
2860 struct ring_buffer_event *event;
2861 struct ring_buffer *buffer;
2862 struct ftrace_entry *entry;
2863 unsigned long flags;
2868 pc = preempt_count();
2869 preempt_disable_notrace();
2870 cpu = raw_smp_processor_id();
2871 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
2876 local_save_flags(flags);
2878 event = trace_current_buffer_lock_reserve(&buffer,
2879 TRACE_FN, sizeof(*entry),
2883 entry = ring_buffer_event_data(event);
2885 entry->parent_ip = parent_ip;
2887 trace_buffer_unlock_commit(buffer, event, flags, pc);
2890 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
2891 preempt_enable_notrace();
2894 static struct ftrace_ops trace_ops __initdata =
2896 .func = function_test_events_call,
2897 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
2900 static __init void event_trace_self_test_with_function(void)
2903 ret = register_ftrace_function(&trace_ops);
2904 if (WARN_ON(ret < 0)) {
2905 pr_info("Failed to enable function tracer for event tests\n");
2908 pr_info("Running tests again, along with the function tracer\n");
2909 event_trace_self_tests();
2910 unregister_ftrace_function(&trace_ops);
2913 static __init void event_trace_self_test_with_function(void)
2918 static __init int event_trace_self_tests_init(void)
2920 if (!tracing_selftest_disabled) {
2921 event_trace_self_tests();
2922 event_trace_self_test_with_function();
2928 late_initcall(event_trace_self_tests_init);