4 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
6 * - Added format output of fields of the trace point.
7 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
11 #include <linux/workqueue.h>
12 #include <linux/spinlock.h>
13 #include <linux/kthread.h>
14 #include <linux/debugfs.h>
15 #include <linux/uaccess.h>
16 #include <linux/module.h>
17 #include <linux/ctype.h>
18 #include <linux/slab.h>
19 #include <linux/delay.h>
21 #include <asm/setup.h>
23 #include "trace_output.h"
26 #define TRACE_SYSTEM "TRACE_SYSTEM"
28 DEFINE_MUTEX(event_mutex);
30 LIST_HEAD(ftrace_events);
31 static LIST_HEAD(ftrace_common_fields);
33 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
35 static struct kmem_cache *field_cachep;
36 static struct kmem_cache *file_cachep;
38 #define SYSTEM_FL_FREE_NAME (1 << 31)
40 static inline int system_refcount(struct event_subsystem *system)
42 return system->ref_count & ~SYSTEM_FL_FREE_NAME;
45 static int system_refcount_inc(struct event_subsystem *system)
47 return (system->ref_count++) & ~SYSTEM_FL_FREE_NAME;
50 static int system_refcount_dec(struct event_subsystem *system)
52 return (--system->ref_count) & ~SYSTEM_FL_FREE_NAME;
55 /* Double loops, do not use break, only goto's work */
56 #define do_for_each_event_file(tr, file) \
57 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
58 list_for_each_entry(file, &tr->events, list)
60 #define do_for_each_event_file_safe(tr, file) \
61 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
62 struct ftrace_event_file *___n; \
63 list_for_each_entry_safe(file, ___n, &tr->events, list)
65 #define while_for_each_event_file() \
68 static struct list_head *
69 trace_get_fields(struct ftrace_event_call *event_call)
71 if (!event_call->class->get_fields)
72 return &event_call->class->fields;
73 return event_call->class->get_fields(event_call);
76 static struct ftrace_event_field *
77 __find_event_field(struct list_head *head, char *name)
79 struct ftrace_event_field *field;
81 list_for_each_entry(field, head, link) {
82 if (!strcmp(field->name, name))
89 struct ftrace_event_field *
90 trace_find_event_field(struct ftrace_event_call *call, char *name)
92 struct ftrace_event_field *field;
93 struct list_head *head;
95 field = __find_event_field(&ftrace_common_fields, name);
99 head = trace_get_fields(call);
100 return __find_event_field(head, name);
103 static int __trace_define_field(struct list_head *head, const char *type,
104 const char *name, int offset, int size,
105 int is_signed, int filter_type)
107 struct ftrace_event_field *field;
109 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
116 if (filter_type == FILTER_OTHER)
117 field->filter_type = filter_assign_type(type);
119 field->filter_type = filter_type;
121 field->offset = offset;
123 field->is_signed = is_signed;
125 list_add(&field->link, head);
130 int trace_define_field(struct ftrace_event_call *call, const char *type,
131 const char *name, int offset, int size, int is_signed,
134 struct list_head *head;
136 if (WARN_ON(!call->class))
139 head = trace_get_fields(call);
140 return __trace_define_field(head, type, name, offset, size,
141 is_signed, filter_type);
143 EXPORT_SYMBOL_GPL(trace_define_field);
145 #define __common_field(type, item) \
146 ret = __trace_define_field(&ftrace_common_fields, #type, \
148 offsetof(typeof(ent), item), \
150 is_signed_type(type), FILTER_OTHER); \
154 static int trace_define_common_fields(void)
157 struct trace_entry ent;
159 __common_field(unsigned short, type);
160 __common_field(unsigned char, flags);
161 __common_field(unsigned char, preempt_count);
162 __common_field(int, pid);
167 static void trace_destroy_fields(struct ftrace_event_call *call)
169 struct ftrace_event_field *field, *next;
170 struct list_head *head;
172 head = trace_get_fields(call);
173 list_for_each_entry_safe(field, next, head, link) {
174 list_del(&field->link);
175 kmem_cache_free(field_cachep, field);
179 int trace_event_raw_init(struct ftrace_event_call *call)
183 id = register_ftrace_event(&call->event);
189 EXPORT_SYMBOL_GPL(trace_event_raw_init);
191 void *ftrace_event_buffer_reserve(struct ftrace_event_buffer *fbuffer,
192 struct ftrace_event_file *ftrace_file,
195 struct ftrace_event_call *event_call = ftrace_file->event_call;
197 local_save_flags(fbuffer->flags);
198 fbuffer->pc = preempt_count();
199 fbuffer->ftrace_file = ftrace_file;
202 trace_event_buffer_lock_reserve(&fbuffer->buffer, ftrace_file,
203 event_call->event.type, len,
204 fbuffer->flags, fbuffer->pc);
208 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
209 return fbuffer->entry;
211 EXPORT_SYMBOL_GPL(ftrace_event_buffer_reserve);
213 void ftrace_event_buffer_commit(struct ftrace_event_buffer *fbuffer)
215 event_trigger_unlock_commit(fbuffer->ftrace_file, fbuffer->buffer,
216 fbuffer->event, fbuffer->entry,
217 fbuffer->flags, fbuffer->pc);
219 EXPORT_SYMBOL_GPL(ftrace_event_buffer_commit);
221 int ftrace_event_reg(struct ftrace_event_call *call,
222 enum trace_reg type, void *data)
224 struct ftrace_event_file *file = data;
226 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
228 case TRACE_REG_REGISTER:
229 return tracepoint_probe_register(call->tp,
232 case TRACE_REG_UNREGISTER:
233 tracepoint_probe_unregister(call->tp,
238 #ifdef CONFIG_PERF_EVENTS
239 case TRACE_REG_PERF_REGISTER:
240 return tracepoint_probe_register(call->tp,
241 call->class->perf_probe,
243 case TRACE_REG_PERF_UNREGISTER:
244 tracepoint_probe_unregister(call->tp,
245 call->class->perf_probe,
248 case TRACE_REG_PERF_OPEN:
249 case TRACE_REG_PERF_CLOSE:
250 case TRACE_REG_PERF_ADD:
251 case TRACE_REG_PERF_DEL:
257 EXPORT_SYMBOL_GPL(ftrace_event_reg);
259 void trace_event_enable_cmd_record(bool enable)
261 struct ftrace_event_file *file;
262 struct trace_array *tr;
264 mutex_lock(&event_mutex);
265 do_for_each_event_file(tr, file) {
267 if (!(file->flags & FTRACE_EVENT_FL_ENABLED))
271 tracing_start_cmdline_record();
272 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
274 tracing_stop_cmdline_record();
275 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
277 } while_for_each_event_file();
278 mutex_unlock(&event_mutex);
281 static int __ftrace_event_enable_disable(struct ftrace_event_file *file,
282 int enable, int soft_disable)
284 struct ftrace_event_call *call = file->event_call;
291 * When soft_disable is set and enable is cleared, the sm_ref
292 * reference counter is decremented. If it reaches 0, we want
293 * to clear the SOFT_DISABLED flag but leave the event in the
294 * state that it was. That is, if the event was enabled and
295 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
296 * is set we do not want the event to be enabled before we
299 * When soft_disable is not set but the SOFT_MODE flag is,
300 * we do nothing. Do not disable the tracepoint, otherwise
301 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
304 if (atomic_dec_return(&file->sm_ref) > 0)
306 disable = file->flags & FTRACE_EVENT_FL_SOFT_DISABLED;
307 clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
309 disable = !(file->flags & FTRACE_EVENT_FL_SOFT_MODE);
311 if (disable && (file->flags & FTRACE_EVENT_FL_ENABLED)) {
312 clear_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
313 if (file->flags & FTRACE_EVENT_FL_RECORDED_CMD) {
314 tracing_stop_cmdline_record();
315 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
317 call->class->reg(call, TRACE_REG_UNREGISTER, file);
319 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
320 if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
321 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
323 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
327 * When soft_disable is set and enable is set, we want to
328 * register the tracepoint for the event, but leave the event
329 * as is. That means, if the event was already enabled, we do
330 * nothing (but set SOFT_MODE). If the event is disabled, we
331 * set SOFT_DISABLED before enabling the event tracepoint, so
332 * it still seems to be disabled.
335 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
337 if (atomic_inc_return(&file->sm_ref) > 1)
339 set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
342 if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) {
344 /* Keep the event disabled, when going to SOFT_MODE. */
346 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
348 if (trace_flags & TRACE_ITER_RECORD_CMD) {
349 tracing_start_cmdline_record();
350 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
352 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
354 tracing_stop_cmdline_record();
355 pr_info("event trace: Could not enable event "
356 "%s\n", ftrace_event_name(call));
359 set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
361 /* WAS_ENABLED gets set but never cleared. */
362 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
370 int trace_event_enable_disable(struct ftrace_event_file *file,
371 int enable, int soft_disable)
373 return __ftrace_event_enable_disable(file, enable, soft_disable);
376 static int ftrace_event_enable_disable(struct ftrace_event_file *file,
379 return __ftrace_event_enable_disable(file, enable, 0);
382 static void ftrace_clear_events(struct trace_array *tr)
384 struct ftrace_event_file *file;
386 mutex_lock(&event_mutex);
387 list_for_each_entry(file, &tr->events, list) {
388 ftrace_event_enable_disable(file, 0);
390 mutex_unlock(&event_mutex);
393 static void __put_system(struct event_subsystem *system)
395 struct event_filter *filter = system->filter;
397 WARN_ON_ONCE(system_refcount(system) == 0);
398 if (system_refcount_dec(system))
401 list_del(&system->list);
404 kfree(filter->filter_string);
407 if (system->ref_count & SYSTEM_FL_FREE_NAME)
412 static void __get_system(struct event_subsystem *system)
414 WARN_ON_ONCE(system_refcount(system) == 0);
415 system_refcount_inc(system);
418 static void __get_system_dir(struct ftrace_subsystem_dir *dir)
420 WARN_ON_ONCE(dir->ref_count == 0);
422 __get_system(dir->subsystem);
425 static void __put_system_dir(struct ftrace_subsystem_dir *dir)
427 WARN_ON_ONCE(dir->ref_count == 0);
428 /* If the subsystem is about to be freed, the dir must be too */
429 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
431 __put_system(dir->subsystem);
432 if (!--dir->ref_count)
436 static void put_system(struct ftrace_subsystem_dir *dir)
438 mutex_lock(&event_mutex);
439 __put_system_dir(dir);
440 mutex_unlock(&event_mutex);
443 static void remove_subsystem(struct ftrace_subsystem_dir *dir)
448 if (!--dir->nr_events) {
449 debugfs_remove_recursive(dir->entry);
450 list_del(&dir->list);
451 __put_system_dir(dir);
455 static void remove_event_file_dir(struct ftrace_event_file *file)
457 struct dentry *dir = file->dir;
458 struct dentry *child;
461 spin_lock(&dir->d_lock); /* probably unneeded */
462 list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
463 if (child->d_inode) /* probably unneeded */
464 child->d_inode->i_private = NULL;
466 spin_unlock(&dir->d_lock);
468 debugfs_remove_recursive(dir);
471 list_del(&file->list);
472 remove_subsystem(file->system);
473 free_event_filter(file->filter);
474 kmem_cache_free(file_cachep, file);
478 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
481 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
482 const char *sub, const char *event, int set)
484 struct ftrace_event_file *file;
485 struct ftrace_event_call *call;
489 list_for_each_entry(file, &tr->events, list) {
491 call = file->event_call;
492 name = ftrace_event_name(call);
494 if (!name || !call->class || !call->class->reg)
497 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
501 strcmp(match, name) != 0 &&
502 strcmp(match, call->class->system) != 0)
505 if (sub && strcmp(sub, call->class->system) != 0)
508 if (event && strcmp(event, name) != 0)
511 ftrace_event_enable_disable(file, set);
519 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
520 const char *sub, const char *event, int set)
524 mutex_lock(&event_mutex);
525 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
526 mutex_unlock(&event_mutex);
531 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
533 char *event = NULL, *sub = NULL, *match;
536 * The buf format can be <subsystem>:<event-name>
537 * *:<event-name> means any event by that name.
538 * :<event-name> is the same.
540 * <subsystem>:* means all events in that subsystem
541 * <subsystem>: means the same.
543 * <name> (no ':') means all events in a subsystem with
544 * the name <name> or any event that matches <name>
547 match = strsep(&buf, ":");
553 if (!strlen(sub) || strcmp(sub, "*") == 0)
555 if (!strlen(event) || strcmp(event, "*") == 0)
559 return __ftrace_set_clr_event(tr, match, sub, event, set);
563 * trace_set_clr_event - enable or disable an event
564 * @system: system name to match (NULL for any system)
565 * @event: event name to match (NULL for all events, within system)
566 * @set: 1 to enable, 0 to disable
568 * This is a way for other parts of the kernel to enable or disable
571 * Returns 0 on success, -EINVAL if the parameters do not match any
574 int trace_set_clr_event(const char *system, const char *event, int set)
576 struct trace_array *tr = top_trace_array();
581 return __ftrace_set_clr_event(tr, NULL, system, event, set);
583 EXPORT_SYMBOL_GPL(trace_set_clr_event);
585 /* 128 should be much more than enough */
586 #define EVENT_BUF_SIZE 127
589 ftrace_event_write(struct file *file, const char __user *ubuf,
590 size_t cnt, loff_t *ppos)
592 struct trace_parser parser;
593 struct seq_file *m = file->private_data;
594 struct trace_array *tr = m->private;
600 ret = tracing_update_buffers();
604 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
607 read = trace_get_user(&parser, ubuf, cnt, ppos);
609 if (read >= 0 && trace_parser_loaded((&parser))) {
612 if (*parser.buffer == '!')
615 parser.buffer[parser.idx] = 0;
617 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
625 trace_parser_put(&parser);
631 t_next(struct seq_file *m, void *v, loff_t *pos)
633 struct ftrace_event_file *file = v;
634 struct ftrace_event_call *call;
635 struct trace_array *tr = m->private;
639 list_for_each_entry_continue(file, &tr->events, list) {
640 call = file->event_call;
642 * The ftrace subsystem is for showing formats only.
643 * They can not be enabled or disabled via the event files.
645 if (call->class && call->class->reg)
652 static void *t_start(struct seq_file *m, loff_t *pos)
654 struct ftrace_event_file *file;
655 struct trace_array *tr = m->private;
658 mutex_lock(&event_mutex);
660 file = list_entry(&tr->events, struct ftrace_event_file, list);
661 for (l = 0; l <= *pos; ) {
662 file = t_next(m, file, &l);
670 s_next(struct seq_file *m, void *v, loff_t *pos)
672 struct ftrace_event_file *file = v;
673 struct trace_array *tr = m->private;
677 list_for_each_entry_continue(file, &tr->events, list) {
678 if (file->flags & FTRACE_EVENT_FL_ENABLED)
685 static void *s_start(struct seq_file *m, loff_t *pos)
687 struct ftrace_event_file *file;
688 struct trace_array *tr = m->private;
691 mutex_lock(&event_mutex);
693 file = list_entry(&tr->events, struct ftrace_event_file, list);
694 for (l = 0; l <= *pos; ) {
695 file = s_next(m, file, &l);
702 static int t_show(struct seq_file *m, void *v)
704 struct ftrace_event_file *file = v;
705 struct ftrace_event_call *call = file->event_call;
707 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
708 seq_printf(m, "%s:", call->class->system);
709 seq_printf(m, "%s\n", ftrace_event_name(call));
714 static void t_stop(struct seq_file *m, void *p)
716 mutex_unlock(&event_mutex);
720 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
723 struct ftrace_event_file *file;
727 mutex_lock(&event_mutex);
728 file = event_file_data(filp);
731 mutex_unlock(&event_mutex);
736 if (flags & FTRACE_EVENT_FL_ENABLED &&
737 !(flags & FTRACE_EVENT_FL_SOFT_DISABLED))
740 if (flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
741 flags & FTRACE_EVENT_FL_SOFT_MODE)
746 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
750 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
753 struct ftrace_event_file *file;
757 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
761 ret = tracing_update_buffers();
769 mutex_lock(&event_mutex);
770 file = event_file_data(filp);
772 ret = ftrace_event_enable_disable(file, val);
773 mutex_unlock(&event_mutex);
782 return ret ? ret : cnt;
786 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
789 const char set_to_char[4] = { '?', '0', '1', 'X' };
790 struct ftrace_subsystem_dir *dir = filp->private_data;
791 struct event_subsystem *system = dir->subsystem;
792 struct ftrace_event_call *call;
793 struct ftrace_event_file *file;
794 struct trace_array *tr = dir->tr;
799 mutex_lock(&event_mutex);
800 list_for_each_entry(file, &tr->events, list) {
801 call = file->event_call;
802 if (!ftrace_event_name(call) || !call->class || !call->class->reg)
805 if (system && strcmp(call->class->system, system->name) != 0)
809 * We need to find out if all the events are set
810 * or if all events or cleared, or if we have
813 set |= (1 << !!(file->flags & FTRACE_EVENT_FL_ENABLED));
816 * If we have a mixture, no need to look further.
821 mutex_unlock(&event_mutex);
823 buf[0] = set_to_char[set];
826 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
832 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
835 struct ftrace_subsystem_dir *dir = filp->private_data;
836 struct event_subsystem *system = dir->subsystem;
837 const char *name = NULL;
841 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
845 ret = tracing_update_buffers();
849 if (val != 0 && val != 1)
853 * Opening of "enable" adds a ref count to system,
854 * so the name is safe to use.
859 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
873 FORMAT_FIELD_SEPERATOR = 2,
877 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
879 struct ftrace_event_call *call = event_file_data(m->private);
880 struct list_head *common_head = &ftrace_common_fields;
881 struct list_head *head = trace_get_fields(call);
882 struct list_head *node = v;
886 switch ((unsigned long)v) {
891 case FORMAT_FIELD_SEPERATOR:
895 case FORMAT_PRINTFMT:
901 if (node == common_head)
902 return (void *)FORMAT_FIELD_SEPERATOR;
903 else if (node == head)
904 return (void *)FORMAT_PRINTFMT;
909 static int f_show(struct seq_file *m, void *v)
911 struct ftrace_event_call *call = event_file_data(m->private);
912 struct ftrace_event_field *field;
913 const char *array_descriptor;
915 switch ((unsigned long)v) {
917 seq_printf(m, "name: %s\n", ftrace_event_name(call));
918 seq_printf(m, "ID: %d\n", call->event.type);
919 seq_printf(m, "format:\n");
922 case FORMAT_FIELD_SEPERATOR:
926 case FORMAT_PRINTFMT:
927 seq_printf(m, "\nprint fmt: %s\n",
932 field = list_entry(v, struct ftrace_event_field, link);
934 * Smartly shows the array type(except dynamic array).
937 * If TYPE := TYPE[LEN], it is shown:
938 * field:TYPE VAR[LEN]
940 array_descriptor = strchr(field->type, '[');
942 if (!strncmp(field->type, "__data_loc", 10))
943 array_descriptor = NULL;
945 if (!array_descriptor)
946 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
947 field->type, field->name, field->offset,
948 field->size, !!field->is_signed);
950 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
951 (int)(array_descriptor - field->type),
952 field->type, field->name,
953 array_descriptor, field->offset,
954 field->size, !!field->is_signed);
959 static void *f_start(struct seq_file *m, loff_t *pos)
961 void *p = (void *)FORMAT_HEADER;
964 /* ->stop() is called even if ->start() fails */
965 mutex_lock(&event_mutex);
966 if (!event_file_data(m->private))
967 return ERR_PTR(-ENODEV);
969 while (l < *pos && p)
970 p = f_next(m, p, &l);
975 static void f_stop(struct seq_file *m, void *p)
977 mutex_unlock(&event_mutex);
980 static const struct seq_operations trace_format_seq_ops = {
987 static int trace_format_open(struct inode *inode, struct file *file)
992 ret = seq_open(file, &trace_format_seq_ops);
996 m = file->private_data;
1003 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1005 int id = (long)event_file_data(filp);
1015 len = sprintf(buf, "%d\n", id);
1017 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1021 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1024 struct ftrace_event_file *file;
1025 struct trace_seq *s;
1031 s = kmalloc(sizeof(*s), GFP_KERNEL);
1038 mutex_lock(&event_mutex);
1039 file = event_file_data(filp);
1041 print_event_filter(file, s);
1042 mutex_unlock(&event_mutex);
1045 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1053 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1056 struct ftrace_event_file *file;
1060 if (cnt >= PAGE_SIZE)
1063 buf = (char *)__get_free_page(GFP_TEMPORARY);
1067 if (copy_from_user(buf, ubuf, cnt)) {
1068 free_page((unsigned long) buf);
1073 mutex_lock(&event_mutex);
1074 file = event_file_data(filp);
1076 err = apply_event_filter(file, buf);
1077 mutex_unlock(&event_mutex);
1079 free_page((unsigned long) buf);
1088 static LIST_HEAD(event_subsystems);
1090 static int subsystem_open(struct inode *inode, struct file *filp)
1092 struct event_subsystem *system = NULL;
1093 struct ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1094 struct trace_array *tr;
1097 if (tracing_is_disabled())
1100 /* Make sure the system still exists */
1101 mutex_lock(&trace_types_lock);
1102 mutex_lock(&event_mutex);
1103 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1104 list_for_each_entry(dir, &tr->systems, list) {
1105 if (dir == inode->i_private) {
1106 /* Don't open systems with no events */
1107 if (dir->nr_events) {
1108 __get_system_dir(dir);
1109 system = dir->subsystem;
1116 mutex_unlock(&event_mutex);
1117 mutex_unlock(&trace_types_lock);
1122 /* Some versions of gcc think dir can be uninitialized here */
1125 /* Still need to increment the ref count of the system */
1126 if (trace_array_get(tr) < 0) {
1131 ret = tracing_open_generic(inode, filp);
1133 trace_array_put(tr);
1140 static int system_tr_open(struct inode *inode, struct file *filp)
1142 struct ftrace_subsystem_dir *dir;
1143 struct trace_array *tr = inode->i_private;
1146 if (tracing_is_disabled())
1149 if (trace_array_get(tr) < 0)
1152 /* Make a temporary dir that has no system but points to tr */
1153 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1155 trace_array_put(tr);
1161 ret = tracing_open_generic(inode, filp);
1163 trace_array_put(tr);
1168 filp->private_data = dir;
1173 static int subsystem_release(struct inode *inode, struct file *file)
1175 struct ftrace_subsystem_dir *dir = file->private_data;
1177 trace_array_put(dir->tr);
1180 * If dir->subsystem is NULL, then this is a temporary
1181 * descriptor that was made for a trace_array to enable
1193 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1196 struct ftrace_subsystem_dir *dir = filp->private_data;
1197 struct event_subsystem *system = dir->subsystem;
1198 struct trace_seq *s;
1204 s = kmalloc(sizeof(*s), GFP_KERNEL);
1210 print_subsystem_event_filter(system, s);
1211 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1219 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1222 struct ftrace_subsystem_dir *dir = filp->private_data;
1226 if (cnt >= PAGE_SIZE)
1229 buf = (char *)__get_free_page(GFP_TEMPORARY);
1233 if (copy_from_user(buf, ubuf, cnt)) {
1234 free_page((unsigned long) buf);
1239 err = apply_subsystem_event_filter(dir, buf);
1240 free_page((unsigned long) buf);
1250 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1252 int (*func)(struct trace_seq *s) = filp->private_data;
1253 struct trace_seq *s;
1259 s = kmalloc(sizeof(*s), GFP_KERNEL);
1266 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1273 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1274 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1275 static int ftrace_event_release(struct inode *inode, struct file *file);
1277 static const struct seq_operations show_event_seq_ops = {
1284 static const struct seq_operations show_set_event_seq_ops = {
1291 static const struct file_operations ftrace_avail_fops = {
1292 .open = ftrace_event_avail_open,
1294 .llseek = seq_lseek,
1295 .release = seq_release,
1298 static const struct file_operations ftrace_set_event_fops = {
1299 .open = ftrace_event_set_open,
1301 .write = ftrace_event_write,
1302 .llseek = seq_lseek,
1303 .release = ftrace_event_release,
1306 static const struct file_operations ftrace_enable_fops = {
1307 .open = tracing_open_generic,
1308 .read = event_enable_read,
1309 .write = event_enable_write,
1310 .llseek = default_llseek,
1313 static const struct file_operations ftrace_event_format_fops = {
1314 .open = trace_format_open,
1316 .llseek = seq_lseek,
1317 .release = seq_release,
1320 static const struct file_operations ftrace_event_id_fops = {
1321 .read = event_id_read,
1322 .llseek = default_llseek,
1325 static const struct file_operations ftrace_event_filter_fops = {
1326 .open = tracing_open_generic,
1327 .read = event_filter_read,
1328 .write = event_filter_write,
1329 .llseek = default_llseek,
1332 static const struct file_operations ftrace_subsystem_filter_fops = {
1333 .open = subsystem_open,
1334 .read = subsystem_filter_read,
1335 .write = subsystem_filter_write,
1336 .llseek = default_llseek,
1337 .release = subsystem_release,
1340 static const struct file_operations ftrace_system_enable_fops = {
1341 .open = subsystem_open,
1342 .read = system_enable_read,
1343 .write = system_enable_write,
1344 .llseek = default_llseek,
1345 .release = subsystem_release,
1348 static const struct file_operations ftrace_tr_enable_fops = {
1349 .open = system_tr_open,
1350 .read = system_enable_read,
1351 .write = system_enable_write,
1352 .llseek = default_llseek,
1353 .release = subsystem_release,
1356 static const struct file_operations ftrace_show_header_fops = {
1357 .open = tracing_open_generic,
1358 .read = show_header,
1359 .llseek = default_llseek,
1363 ftrace_event_open(struct inode *inode, struct file *file,
1364 const struct seq_operations *seq_ops)
1369 ret = seq_open(file, seq_ops);
1372 m = file->private_data;
1373 /* copy tr over to seq ops */
1374 m->private = inode->i_private;
1379 static int ftrace_event_release(struct inode *inode, struct file *file)
1381 struct trace_array *tr = inode->i_private;
1383 trace_array_put(tr);
1385 return seq_release(inode, file);
1389 ftrace_event_avail_open(struct inode *inode, struct file *file)
1391 const struct seq_operations *seq_ops = &show_event_seq_ops;
1393 return ftrace_event_open(inode, file, seq_ops);
1397 ftrace_event_set_open(struct inode *inode, struct file *file)
1399 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1400 struct trace_array *tr = inode->i_private;
1403 if (trace_array_get(tr) < 0)
1406 if ((file->f_mode & FMODE_WRITE) &&
1407 (file->f_flags & O_TRUNC))
1408 ftrace_clear_events(tr);
1410 ret = ftrace_event_open(inode, file, seq_ops);
1412 trace_array_put(tr);
1416 static struct event_subsystem *
1417 create_new_subsystem(const char *name)
1419 struct event_subsystem *system;
1421 /* need to create new entry */
1422 system = kmalloc(sizeof(*system), GFP_KERNEL);
1426 system->ref_count = 1;
1428 /* Only allocate if dynamic (kprobes and modules) */
1429 if (!core_kernel_data((unsigned long)name)) {
1430 system->ref_count |= SYSTEM_FL_FREE_NAME;
1431 system->name = kstrdup(name, GFP_KERNEL);
1435 system->name = name;
1437 system->filter = NULL;
1439 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1440 if (!system->filter)
1443 list_add(&system->list, &event_subsystems);
1448 if (system->ref_count & SYSTEM_FL_FREE_NAME)
1449 kfree(system->name);
1454 static struct dentry *
1455 event_subsystem_dir(struct trace_array *tr, const char *name,
1456 struct ftrace_event_file *file, struct dentry *parent)
1458 struct ftrace_subsystem_dir *dir;
1459 struct event_subsystem *system;
1460 struct dentry *entry;
1462 /* First see if we did not already create this dir */
1463 list_for_each_entry(dir, &tr->systems, list) {
1464 system = dir->subsystem;
1465 if (strcmp(system->name, name) == 0) {
1472 /* Now see if the system itself exists. */
1473 list_for_each_entry(system, &event_subsystems, list) {
1474 if (strcmp(system->name, name) == 0)
1477 /* Reset system variable when not found */
1478 if (&system->list == &event_subsystems)
1481 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1486 system = create_new_subsystem(name);
1490 __get_system(system);
1492 dir->entry = debugfs_create_dir(name, parent);
1494 pr_warning("Failed to create system directory %s\n", name);
1495 __put_system(system);
1502 dir->subsystem = system;
1505 entry = debugfs_create_file("filter", 0644, dir->entry, dir,
1506 &ftrace_subsystem_filter_fops);
1508 kfree(system->filter);
1509 system->filter = NULL;
1510 pr_warning("Could not create debugfs '%s/filter' entry\n", name);
1513 trace_create_file("enable", 0644, dir->entry, dir,
1514 &ftrace_system_enable_fops);
1516 list_add(&dir->list, &tr->systems);
1523 /* Only print this message if failed on memory allocation */
1524 if (!dir || !system)
1525 pr_warning("No memory to create event subsystem %s\n",
1531 event_create_dir(struct dentry *parent, struct ftrace_event_file *file)
1533 struct ftrace_event_call *call = file->event_call;
1534 struct trace_array *tr = file->tr;
1535 struct list_head *head;
1536 struct dentry *d_events;
1541 * If the trace point header did not define TRACE_SYSTEM
1542 * then the system would be called "TRACE_SYSTEM".
1544 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1545 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1551 name = ftrace_event_name(call);
1552 file->dir = debugfs_create_dir(name, d_events);
1554 pr_warning("Could not create debugfs '%s' directory\n",
1559 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1560 trace_create_file("enable", 0644, file->dir, file,
1561 &ftrace_enable_fops);
1563 #ifdef CONFIG_PERF_EVENTS
1564 if (call->event.type && call->class->reg)
1565 trace_create_file("id", 0444, file->dir,
1566 (void *)(long)call->event.type,
1567 &ftrace_event_id_fops);
1571 * Other events may have the same class. Only update
1572 * the fields if they are not already defined.
1574 head = trace_get_fields(call);
1575 if (list_empty(head)) {
1576 ret = call->class->define_fields(call);
1578 pr_warning("Could not initialize trace point"
1579 " events/%s\n", name);
1583 trace_create_file("filter", 0644, file->dir, file,
1584 &ftrace_event_filter_fops);
1586 trace_create_file("trigger", 0644, file->dir, file,
1587 &event_trigger_fops);
1589 trace_create_file("format", 0444, file->dir, call,
1590 &ftrace_event_format_fops);
1595 static void remove_event_from_tracers(struct ftrace_event_call *call)
1597 struct ftrace_event_file *file;
1598 struct trace_array *tr;
1600 do_for_each_event_file_safe(tr, file) {
1601 if (file->event_call != call)
1604 remove_event_file_dir(file);
1606 * The do_for_each_event_file_safe() is
1607 * a double loop. After finding the call for this
1608 * trace_array, we use break to jump to the next
1612 } while_for_each_event_file();
1615 static void event_remove(struct ftrace_event_call *call)
1617 struct trace_array *tr;
1618 struct ftrace_event_file *file;
1620 do_for_each_event_file(tr, file) {
1621 if (file->event_call != call)
1623 ftrace_event_enable_disable(file, 0);
1624 destroy_preds(file);
1626 * The do_for_each_event_file() is
1627 * a double loop. After finding the call for this
1628 * trace_array, we use break to jump to the next
1632 } while_for_each_event_file();
1634 if (call->event.funcs)
1635 __unregister_ftrace_event(&call->event);
1636 remove_event_from_tracers(call);
1637 list_del(&call->list);
1640 static int event_init(struct ftrace_event_call *call)
1645 name = ftrace_event_name(call);
1649 if (call->class->raw_init) {
1650 ret = call->class->raw_init(call);
1651 if (ret < 0 && ret != -ENOSYS)
1652 pr_warn("Could not initialize trace events/%s\n",
1660 __register_event(struct ftrace_event_call *call, struct module *mod)
1664 ret = event_init(call);
1668 list_add(&call->list, &ftrace_events);
1674 static struct ftrace_event_file *
1675 trace_create_new_event(struct ftrace_event_call *call,
1676 struct trace_array *tr)
1678 struct ftrace_event_file *file;
1680 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
1684 file->event_call = call;
1686 atomic_set(&file->sm_ref, 0);
1687 atomic_set(&file->tm_ref, 0);
1688 INIT_LIST_HEAD(&file->triggers);
1689 list_add(&file->list, &tr->events);
1694 /* Add an event to a trace directory */
1696 __trace_add_new_event(struct ftrace_event_call *call, struct trace_array *tr)
1698 struct ftrace_event_file *file;
1700 file = trace_create_new_event(call, tr);
1704 return event_create_dir(tr->event_dir, file);
1708 * Just create a decriptor for early init. A descriptor is required
1709 * for enabling events at boot. We want to enable events before
1710 * the filesystem is initialized.
1713 __trace_early_add_new_event(struct ftrace_event_call *call,
1714 struct trace_array *tr)
1716 struct ftrace_event_file *file;
1718 file = trace_create_new_event(call, tr);
1725 struct ftrace_module_file_ops;
1726 static void __add_event_to_tracers(struct ftrace_event_call *call);
1728 /* Add an additional event_call dynamically */
1729 int trace_add_event_call(struct ftrace_event_call *call)
1732 mutex_lock(&trace_types_lock);
1733 mutex_lock(&event_mutex);
1735 ret = __register_event(call, NULL);
1737 __add_event_to_tracers(call);
1739 mutex_unlock(&event_mutex);
1740 mutex_unlock(&trace_types_lock);
1745 * Must be called under locking of trace_types_lock, event_mutex and
1748 static void __trace_remove_event_call(struct ftrace_event_call *call)
1751 trace_destroy_fields(call);
1752 destroy_call_preds(call);
1755 static int probe_remove_event_call(struct ftrace_event_call *call)
1757 struct trace_array *tr;
1758 struct ftrace_event_file *file;
1760 #ifdef CONFIG_PERF_EVENTS
1761 if (call->perf_refcount)
1764 do_for_each_event_file(tr, file) {
1765 if (file->event_call != call)
1768 * We can't rely on ftrace_event_enable_disable(enable => 0)
1769 * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
1770 * TRACE_REG_UNREGISTER.
1772 if (file->flags & FTRACE_EVENT_FL_ENABLED)
1775 * The do_for_each_event_file_safe() is
1776 * a double loop. After finding the call for this
1777 * trace_array, we use break to jump to the next
1781 } while_for_each_event_file();
1783 __trace_remove_event_call(call);
1788 /* Remove an event_call */
1789 int trace_remove_event_call(struct ftrace_event_call *call)
1793 mutex_lock(&trace_types_lock);
1794 mutex_lock(&event_mutex);
1795 down_write(&trace_event_sem);
1796 ret = probe_remove_event_call(call);
1797 up_write(&trace_event_sem);
1798 mutex_unlock(&event_mutex);
1799 mutex_unlock(&trace_types_lock);
1804 #define for_each_event(event, start, end) \
1805 for (event = start; \
1806 (unsigned long)event < (unsigned long)end; \
1809 #ifdef CONFIG_MODULES
1811 static void trace_module_add_events(struct module *mod)
1813 struct ftrace_event_call **call, **start, **end;
1815 if (!mod->num_trace_events)
1818 /* Don't add infrastructure for mods without tracepoints */
1819 if (trace_module_has_bad_taint(mod)) {
1820 pr_err("%s: module has bad taint, not creating trace events\n",
1825 start = mod->trace_events;
1826 end = mod->trace_events + mod->num_trace_events;
1828 for_each_event(call, start, end) {
1829 __register_event(*call, mod);
1830 __add_event_to_tracers(*call);
1834 static void trace_module_remove_events(struct module *mod)
1836 struct ftrace_event_call *call, *p;
1837 bool clear_trace = false;
1839 down_write(&trace_event_sem);
1840 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1841 if (call->mod == mod) {
1842 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
1844 __trace_remove_event_call(call);
1847 up_write(&trace_event_sem);
1850 * It is safest to reset the ring buffer if the module being unloaded
1851 * registered any events that were used. The only worry is if
1852 * a new module gets loaded, and takes on the same id as the events
1853 * of this module. When printing out the buffer, traced events left
1854 * over from this module may be passed to the new module events and
1855 * unexpected results may occur.
1858 tracing_reset_all_online_cpus();
1861 static int trace_module_notify(struct notifier_block *self,
1862 unsigned long val, void *data)
1864 struct module *mod = data;
1866 mutex_lock(&trace_types_lock);
1867 mutex_lock(&event_mutex);
1869 case MODULE_STATE_COMING:
1870 trace_module_add_events(mod);
1872 case MODULE_STATE_GOING:
1873 trace_module_remove_events(mod);
1876 mutex_unlock(&event_mutex);
1877 mutex_unlock(&trace_types_lock);
1882 static struct notifier_block trace_module_nb = {
1883 .notifier_call = trace_module_notify,
1886 #endif /* CONFIG_MODULES */
1888 /* Create a new event directory structure for a trace directory. */
1890 __trace_add_event_dirs(struct trace_array *tr)
1892 struct ftrace_event_call *call;
1895 list_for_each_entry(call, &ftrace_events, list) {
1896 ret = __trace_add_new_event(call, tr);
1898 pr_warning("Could not create directory for event %s\n",
1899 ftrace_event_name(call));
1903 struct ftrace_event_file *
1904 find_event_file(struct trace_array *tr, const char *system, const char *event)
1906 struct ftrace_event_file *file;
1907 struct ftrace_event_call *call;
1910 list_for_each_entry(file, &tr->events, list) {
1912 call = file->event_call;
1913 name = ftrace_event_name(call);
1915 if (!name || !call->class || !call->class->reg)
1918 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1921 if (strcmp(event, name) == 0 &&
1922 strcmp(system, call->class->system) == 0)
1928 #ifdef CONFIG_DYNAMIC_FTRACE
1931 #define ENABLE_EVENT_STR "enable_event"
1932 #define DISABLE_EVENT_STR "disable_event"
1934 struct event_probe_data {
1935 struct ftrace_event_file *file;
1936 unsigned long count;
1942 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1944 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1945 struct event_probe_data *data = *pdata;
1951 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1953 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1957 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1959 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1960 struct event_probe_data *data = *pdata;
1968 /* Skip if the event is in a state we want to switch to */
1969 if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
1972 if (data->count != -1)
1975 event_enable_probe(ip, parent_ip, _data);
1979 event_enable_print(struct seq_file *m, unsigned long ip,
1980 struct ftrace_probe_ops *ops, void *_data)
1982 struct event_probe_data *data = _data;
1984 seq_printf(m, "%ps:", (void *)ip);
1986 seq_printf(m, "%s:%s:%s",
1987 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
1988 data->file->event_call->class->system,
1989 ftrace_event_name(data->file->event_call));
1991 if (data->count == -1)
1992 seq_printf(m, ":unlimited\n");
1994 seq_printf(m, ":count=%ld\n", data->count);
2000 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
2003 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2004 struct event_probe_data *data = *pdata;
2011 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
2014 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2015 struct event_probe_data *data = *pdata;
2017 if (WARN_ON_ONCE(data->ref <= 0))
2022 /* Remove the SOFT_MODE flag */
2023 __ftrace_event_enable_disable(data->file, 0, 1);
2024 module_put(data->file->event_call->mod);
2030 static struct ftrace_probe_ops event_enable_probe_ops = {
2031 .func = event_enable_probe,
2032 .print = event_enable_print,
2033 .init = event_enable_init,
2034 .free = event_enable_free,
2037 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2038 .func = event_enable_count_probe,
2039 .print = event_enable_print,
2040 .init = event_enable_init,
2041 .free = event_enable_free,
2044 static struct ftrace_probe_ops event_disable_probe_ops = {
2045 .func = event_enable_probe,
2046 .print = event_enable_print,
2047 .init = event_enable_init,
2048 .free = event_enable_free,
2051 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2052 .func = event_enable_count_probe,
2053 .print = event_enable_print,
2054 .init = event_enable_init,
2055 .free = event_enable_free,
2059 event_enable_func(struct ftrace_hash *hash,
2060 char *glob, char *cmd, char *param, int enabled)
2062 struct trace_array *tr = top_trace_array();
2063 struct ftrace_event_file *file;
2064 struct ftrace_probe_ops *ops;
2065 struct event_probe_data *data;
2075 /* hash funcs only work with set_ftrace_filter */
2076 if (!enabled || !param)
2079 system = strsep(¶m, ":");
2083 event = strsep(¶m, ":");
2085 mutex_lock(&event_mutex);
2088 file = find_event_file(tr, system, event);
2092 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2095 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2097 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2099 if (glob[0] == '!') {
2100 unregister_ftrace_function_probe_func(glob+1, ops);
2106 data = kzalloc(sizeof(*data), GFP_KERNEL);
2110 data->enable = enable;
2117 number = strsep(¶m, ":");
2120 if (!strlen(number))
2124 * We use the callback data field (which is a pointer)
2127 ret = kstrtoul(number, 0, &data->count);
2132 /* Don't let event modules unload while probe registered */
2133 ret = try_module_get(file->event_call->mod);
2139 ret = __ftrace_event_enable_disable(file, 1, 1);
2142 ret = register_ftrace_function_probe(glob, ops, data);
2144 * The above returns on success the # of functions enabled,
2145 * but if it didn't find any functions it returns zero.
2146 * Consider no functions a failure too.
2153 /* Just return zero, not the number of enabled functions */
2156 mutex_unlock(&event_mutex);
2160 __ftrace_event_enable_disable(file, 0, 1);
2162 module_put(file->event_call->mod);
2168 static struct ftrace_func_command event_enable_cmd = {
2169 .name = ENABLE_EVENT_STR,
2170 .func = event_enable_func,
2173 static struct ftrace_func_command event_disable_cmd = {
2174 .name = DISABLE_EVENT_STR,
2175 .func = event_enable_func,
2178 static __init int register_event_cmds(void)
2182 ret = register_ftrace_command(&event_enable_cmd);
2183 if (WARN_ON(ret < 0))
2185 ret = register_ftrace_command(&event_disable_cmd);
2186 if (WARN_ON(ret < 0))
2187 unregister_ftrace_command(&event_enable_cmd);
2191 static inline int register_event_cmds(void) { return 0; }
2192 #endif /* CONFIG_DYNAMIC_FTRACE */
2195 * The top level array has already had its ftrace_event_file
2196 * descriptors created in order to allow for early events to
2197 * be recorded. This function is called after the debugfs has been
2198 * initialized, and we now have to create the files associated
2202 __trace_early_add_event_dirs(struct trace_array *tr)
2204 struct ftrace_event_file *file;
2208 list_for_each_entry(file, &tr->events, list) {
2209 ret = event_create_dir(tr->event_dir, file);
2211 pr_warning("Could not create directory for event %s\n",
2212 ftrace_event_name(file->event_call));
2217 * For early boot up, the top trace array requires to have
2218 * a list of events that can be enabled. This must be done before
2219 * the filesystem is set up in order to allow events to be traced
2223 __trace_early_add_events(struct trace_array *tr)
2225 struct ftrace_event_call *call;
2228 list_for_each_entry(call, &ftrace_events, list) {
2229 /* Early boot up should not have any modules loaded */
2230 if (WARN_ON_ONCE(call->mod))
2233 ret = __trace_early_add_new_event(call, tr);
2235 pr_warning("Could not create early event %s\n",
2236 ftrace_event_name(call));
2240 /* Remove the event directory structure for a trace directory. */
2242 __trace_remove_event_dirs(struct trace_array *tr)
2244 struct ftrace_event_file *file, *next;
2246 list_for_each_entry_safe(file, next, &tr->events, list)
2247 remove_event_file_dir(file);
2250 static void __add_event_to_tracers(struct ftrace_event_call *call)
2252 struct trace_array *tr;
2254 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2255 __trace_add_new_event(call, tr);
2258 extern struct ftrace_event_call *__start_ftrace_events[];
2259 extern struct ftrace_event_call *__stop_ftrace_events[];
2261 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2263 static __init int setup_trace_event(char *str)
2265 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2266 ring_buffer_expanded = true;
2267 tracing_selftest_disabled = true;
2271 __setup("trace_event=", setup_trace_event);
2273 /* Expects to have event_mutex held when called */
2275 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2277 struct dentry *d_events;
2278 struct dentry *entry;
2280 entry = debugfs_create_file("set_event", 0644, parent,
2281 tr, &ftrace_set_event_fops);
2283 pr_warning("Could not create debugfs 'set_event' entry\n");
2287 d_events = debugfs_create_dir("events", parent);
2289 pr_warning("Could not create debugfs 'events' directory\n");
2293 /* ring buffer internal formats */
2294 trace_create_file("header_page", 0444, d_events,
2295 ring_buffer_print_page_header,
2296 &ftrace_show_header_fops);
2298 trace_create_file("header_event", 0444, d_events,
2299 ring_buffer_print_entry_header,
2300 &ftrace_show_header_fops);
2302 trace_create_file("enable", 0644, d_events,
2303 tr, &ftrace_tr_enable_fops);
2305 tr->event_dir = d_events;
2311 * event_trace_add_tracer - add a instance of a trace_array to events
2312 * @parent: The parent dentry to place the files/directories for events in
2313 * @tr: The trace array associated with these events
2315 * When a new instance is created, it needs to set up its events
2316 * directory, as well as other files associated with events. It also
2317 * creates the event hierachry in the @parent/events directory.
2319 * Returns 0 on success.
2321 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2325 mutex_lock(&event_mutex);
2327 ret = create_event_toplevel_files(parent, tr);
2331 down_write(&trace_event_sem);
2332 __trace_add_event_dirs(tr);
2333 up_write(&trace_event_sem);
2336 mutex_unlock(&event_mutex);
2342 * The top trace array already had its file descriptors created.
2343 * Now the files themselves need to be created.
2346 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2350 mutex_lock(&event_mutex);
2352 ret = create_event_toplevel_files(parent, tr);
2356 down_write(&trace_event_sem);
2357 __trace_early_add_event_dirs(tr);
2358 up_write(&trace_event_sem);
2361 mutex_unlock(&event_mutex);
2366 int event_trace_del_tracer(struct trace_array *tr)
2368 mutex_lock(&event_mutex);
2370 /* Disable any event triggers and associated soft-disabled events */
2371 clear_event_triggers(tr);
2373 /* Disable any running events */
2374 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
2376 /* Access to events are within rcu_read_lock_sched() */
2377 synchronize_sched();
2379 down_write(&trace_event_sem);
2380 __trace_remove_event_dirs(tr);
2381 debugfs_remove_recursive(tr->event_dir);
2382 up_write(&trace_event_sem);
2384 tr->event_dir = NULL;
2386 mutex_unlock(&event_mutex);
2391 static __init int event_trace_memsetup(void)
2393 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
2394 file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC);
2398 static __init int event_trace_enable(void)
2400 struct trace_array *tr = top_trace_array();
2401 struct ftrace_event_call **iter, *call;
2402 char *buf = bootup_event_buf;
2409 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
2412 ret = event_init(call);
2414 list_add(&call->list, &ftrace_events);
2418 * We need the top trace array to have a working set of trace
2419 * points at early init, before the debug files and directories
2420 * are created. Create the file entries now, and attach them
2421 * to the actual file dentries later.
2423 __trace_early_add_events(tr);
2426 token = strsep(&buf, ",");
2433 ret = ftrace_set_clr_event(tr, token, 1);
2435 pr_warn("Failed to enable trace event: %s\n", token);
2438 trace_printk_start_comm();
2440 register_event_cmds();
2442 register_trigger_cmds();
2447 static __init int event_trace_init(void)
2449 struct trace_array *tr;
2450 struct dentry *d_tracer;
2451 struct dentry *entry;
2454 tr = top_trace_array();
2458 d_tracer = tracing_init_dentry();
2462 entry = debugfs_create_file("available_events", 0444, d_tracer,
2463 tr, &ftrace_avail_fops);
2465 pr_warning("Could not create debugfs "
2466 "'available_events' entry\n");
2468 if (trace_define_common_fields())
2469 pr_warning("tracing: Failed to allocate common fields");
2471 ret = early_event_add_tracer(d_tracer, tr);
2475 #ifdef CONFIG_MODULES
2476 ret = register_module_notifier(&trace_module_nb);
2478 pr_warning("Failed to register trace events module notifier\n");
2482 early_initcall(event_trace_memsetup);
2483 core_initcall(event_trace_enable);
2484 fs_initcall(event_trace_init);
2486 #ifdef CONFIG_FTRACE_STARTUP_TEST
2488 static DEFINE_SPINLOCK(test_spinlock);
2489 static DEFINE_SPINLOCK(test_spinlock_irq);
2490 static DEFINE_MUTEX(test_mutex);
2492 static __init void test_work(struct work_struct *dummy)
2494 spin_lock(&test_spinlock);
2495 spin_lock_irq(&test_spinlock_irq);
2497 spin_unlock_irq(&test_spinlock_irq);
2498 spin_unlock(&test_spinlock);
2500 mutex_lock(&test_mutex);
2502 mutex_unlock(&test_mutex);
2505 static __init int event_test_thread(void *unused)
2509 test_malloc = kmalloc(1234, GFP_KERNEL);
2511 pr_info("failed to kmalloc\n");
2513 schedule_on_each_cpu(test_work);
2517 set_current_state(TASK_INTERRUPTIBLE);
2518 while (!kthread_should_stop())
2525 * Do various things that may trigger events.
2527 static __init void event_test_stuff(void)
2529 struct task_struct *test_thread;
2531 test_thread = kthread_run(event_test_thread, NULL, "test-events");
2533 kthread_stop(test_thread);
2537 * For every trace event defined, we will test each trace point separately,
2538 * and then by groups, and finally all trace points.
2540 static __init void event_trace_self_tests(void)
2542 struct ftrace_subsystem_dir *dir;
2543 struct ftrace_event_file *file;
2544 struct ftrace_event_call *call;
2545 struct event_subsystem *system;
2546 struct trace_array *tr;
2549 tr = top_trace_array();
2553 pr_info("Running tests on trace events:\n");
2555 list_for_each_entry(file, &tr->events, list) {
2557 call = file->event_call;
2559 /* Only test those that have a probe */
2560 if (!call->class || !call->class->probe)
2564 * Testing syscall events here is pretty useless, but
2565 * we still do it if configured. But this is time consuming.
2566 * What we really need is a user thread to perform the
2567 * syscalls as we test.
2569 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
2570 if (call->class->system &&
2571 strcmp(call->class->system, "syscalls") == 0)
2575 pr_info("Testing event %s: ", ftrace_event_name(call));
2578 * If an event is already enabled, someone is using
2579 * it and the self test should not be on.
2581 if (file->flags & FTRACE_EVENT_FL_ENABLED) {
2582 pr_warning("Enabled event during self test!\n");
2587 ftrace_event_enable_disable(file, 1);
2589 ftrace_event_enable_disable(file, 0);
2594 /* Now test at the sub system level */
2596 pr_info("Running tests on trace event systems:\n");
2598 list_for_each_entry(dir, &tr->systems, list) {
2600 system = dir->subsystem;
2602 /* the ftrace system is special, skip it */
2603 if (strcmp(system->name, "ftrace") == 0)
2606 pr_info("Testing event system %s: ", system->name);
2608 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
2609 if (WARN_ON_ONCE(ret)) {
2610 pr_warning("error enabling system %s\n",
2617 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
2618 if (WARN_ON_ONCE(ret)) {
2619 pr_warning("error disabling system %s\n",
2627 /* Test with all events enabled */
2629 pr_info("Running tests on all trace events:\n");
2630 pr_info("Testing all events: ");
2632 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
2633 if (WARN_ON_ONCE(ret)) {
2634 pr_warning("error enabling all events\n");
2641 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
2642 if (WARN_ON_ONCE(ret)) {
2643 pr_warning("error disabling all events\n");
2650 #ifdef CONFIG_FUNCTION_TRACER
2652 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
2655 function_test_events_call(unsigned long ip, unsigned long parent_ip,
2656 struct ftrace_ops *op, struct pt_regs *pt_regs)
2658 struct ring_buffer_event *event;
2659 struct ring_buffer *buffer;
2660 struct ftrace_entry *entry;
2661 unsigned long flags;
2666 pc = preempt_count();
2667 preempt_disable_notrace();
2668 cpu = raw_smp_processor_id();
2669 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
2674 local_save_flags(flags);
2676 event = trace_current_buffer_lock_reserve(&buffer,
2677 TRACE_FN, sizeof(*entry),
2681 entry = ring_buffer_event_data(event);
2683 entry->parent_ip = parent_ip;
2685 trace_buffer_unlock_commit(buffer, event, flags, pc);
2688 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
2689 preempt_enable_notrace();
2692 static struct ftrace_ops trace_ops __initdata =
2694 .func = function_test_events_call,
2695 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
2698 static __init void event_trace_self_test_with_function(void)
2701 ret = register_ftrace_function(&trace_ops);
2702 if (WARN_ON(ret < 0)) {
2703 pr_info("Failed to enable function tracer for event tests\n");
2706 pr_info("Running tests again, along with the function tracer\n");
2707 event_trace_self_tests();
2708 unregister_ftrace_function(&trace_ops);
2711 static __init void event_trace_self_test_with_function(void)
2716 static __init int event_trace_self_tests_init(void)
2718 if (!tracing_selftest_disabled) {
2719 event_trace_self_tests();
2720 event_trace_self_test_with_function();
2726 late_initcall(event_trace_self_tests_init);