4 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
6 * - Added format output of fields of the trace point.
7 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
11 #include <linux/workqueue.h>
12 #include <linux/spinlock.h>
13 #include <linux/kthread.h>
14 #include <linux/debugfs.h>
15 #include <linux/uaccess.h>
16 #include <linux/module.h>
17 #include <linux/ctype.h>
18 #include <linux/slab.h>
19 #include <linux/delay.h>
21 #include <asm/setup.h>
23 #include "trace_output.h"
26 #define TRACE_SYSTEM "TRACE_SYSTEM"
28 DEFINE_MUTEX(event_mutex);
30 DEFINE_MUTEX(event_storage_mutex);
31 EXPORT_SYMBOL_GPL(event_storage_mutex);
33 char event_storage[EVENT_STORAGE_SIZE];
34 EXPORT_SYMBOL_GPL(event_storage);
36 LIST_HEAD(ftrace_events);
37 static LIST_HEAD(ftrace_common_fields);
39 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
41 static struct kmem_cache *field_cachep;
42 static struct kmem_cache *file_cachep;
44 #define SYSTEM_FL_FREE_NAME (1 << 31)
46 static inline int system_refcount(struct event_subsystem *system)
48 return system->ref_count & ~SYSTEM_FL_FREE_NAME;
51 static int system_refcount_inc(struct event_subsystem *system)
53 return (system->ref_count++) & ~SYSTEM_FL_FREE_NAME;
56 static int system_refcount_dec(struct event_subsystem *system)
58 return (--system->ref_count) & ~SYSTEM_FL_FREE_NAME;
61 /* Double loops, do not use break, only goto's work */
62 #define do_for_each_event_file(tr, file) \
63 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
64 list_for_each_entry(file, &tr->events, list)
66 #define do_for_each_event_file_safe(tr, file) \
67 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
68 struct ftrace_event_file *___n; \
69 list_for_each_entry_safe(file, ___n, &tr->events, list)
71 #define while_for_each_event_file() \
74 static struct list_head *
75 trace_get_fields(struct ftrace_event_call *event_call)
77 if (!event_call->class->get_fields)
78 return &event_call->class->fields;
79 return event_call->class->get_fields(event_call);
82 static struct ftrace_event_field *
83 __find_event_field(struct list_head *head, char *name)
85 struct ftrace_event_field *field;
87 list_for_each_entry(field, head, link) {
88 if (!strcmp(field->name, name))
95 struct ftrace_event_field *
96 trace_find_event_field(struct ftrace_event_call *call, char *name)
98 struct ftrace_event_field *field;
99 struct list_head *head;
101 field = __find_event_field(&ftrace_common_fields, name);
105 head = trace_get_fields(call);
106 return __find_event_field(head, name);
109 static int __trace_define_field(struct list_head *head, const char *type,
110 const char *name, int offset, int size,
111 int is_signed, int filter_type)
113 struct ftrace_event_field *field;
115 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
122 if (filter_type == FILTER_OTHER)
123 field->filter_type = filter_assign_type(type);
125 field->filter_type = filter_type;
127 field->offset = offset;
129 field->is_signed = is_signed;
131 list_add(&field->link, head);
136 int trace_define_field(struct ftrace_event_call *call, const char *type,
137 const char *name, int offset, int size, int is_signed,
140 struct list_head *head;
142 if (WARN_ON(!call->class))
145 head = trace_get_fields(call);
146 return __trace_define_field(head, type, name, offset, size,
147 is_signed, filter_type);
149 EXPORT_SYMBOL_GPL(trace_define_field);
151 #define __common_field(type, item) \
152 ret = __trace_define_field(&ftrace_common_fields, #type, \
154 offsetof(typeof(ent), item), \
156 is_signed_type(type), FILTER_OTHER); \
160 static int trace_define_common_fields(void)
163 struct trace_entry ent;
165 __common_field(unsigned short, type);
166 __common_field(unsigned char, flags);
167 __common_field(unsigned char, preempt_count);
168 __common_field(int, pid);
173 static void trace_destroy_fields(struct ftrace_event_call *call)
175 struct ftrace_event_field *field, *next;
176 struct list_head *head;
178 head = trace_get_fields(call);
179 list_for_each_entry_safe(field, next, head, link) {
180 list_del(&field->link);
181 kmem_cache_free(field_cachep, field);
185 int trace_event_raw_init(struct ftrace_event_call *call)
189 id = register_ftrace_event(&call->event);
195 EXPORT_SYMBOL_GPL(trace_event_raw_init);
197 int ftrace_event_reg(struct ftrace_event_call *call,
198 enum trace_reg type, void *data)
200 struct ftrace_event_file *file = data;
203 case TRACE_REG_REGISTER:
204 return tracepoint_probe_register(call->name,
207 case TRACE_REG_UNREGISTER:
208 tracepoint_probe_unregister(call->name,
213 #ifdef CONFIG_PERF_EVENTS
214 case TRACE_REG_PERF_REGISTER:
215 return tracepoint_probe_register(call->name,
216 call->class->perf_probe,
218 case TRACE_REG_PERF_UNREGISTER:
219 tracepoint_probe_unregister(call->name,
220 call->class->perf_probe,
223 case TRACE_REG_PERF_OPEN:
224 case TRACE_REG_PERF_CLOSE:
225 case TRACE_REG_PERF_ADD:
226 case TRACE_REG_PERF_DEL:
232 EXPORT_SYMBOL_GPL(ftrace_event_reg);
234 void trace_event_enable_cmd_record(bool enable)
236 struct ftrace_event_file *file;
237 struct trace_array *tr;
239 mutex_lock(&event_mutex);
240 do_for_each_event_file(tr, file) {
242 if (!(file->flags & FTRACE_EVENT_FL_ENABLED))
246 tracing_start_cmdline_record();
247 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
249 tracing_stop_cmdline_record();
250 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
252 } while_for_each_event_file();
253 mutex_unlock(&event_mutex);
256 static int __ftrace_event_enable_disable(struct ftrace_event_file *file,
257 int enable, int soft_disable)
259 struct ftrace_event_call *call = file->event_call;
266 * When soft_disable is set and enable is cleared, the sm_ref
267 * reference counter is decremented. If it reaches 0, we want
268 * to clear the SOFT_DISABLED flag but leave the event in the
269 * state that it was. That is, if the event was enabled and
270 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
271 * is set we do not want the event to be enabled before we
274 * When soft_disable is not set but the SOFT_MODE flag is,
275 * we do nothing. Do not disable the tracepoint, otherwise
276 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
279 if (atomic_dec_return(&file->sm_ref) > 0)
281 disable = file->flags & FTRACE_EVENT_FL_SOFT_DISABLED;
282 clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
284 disable = !(file->flags & FTRACE_EVENT_FL_SOFT_MODE);
286 if (disable && (file->flags & FTRACE_EVENT_FL_ENABLED)) {
287 clear_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
288 if (file->flags & FTRACE_EVENT_FL_RECORDED_CMD) {
289 tracing_stop_cmdline_record();
290 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
292 call->class->reg(call, TRACE_REG_UNREGISTER, file);
294 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
295 if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
296 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
298 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
302 * When soft_disable is set and enable is set, we want to
303 * register the tracepoint for the event, but leave the event
304 * as is. That means, if the event was already enabled, we do
305 * nothing (but set SOFT_MODE). If the event is disabled, we
306 * set SOFT_DISABLED before enabling the event tracepoint, so
307 * it still seems to be disabled.
310 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
312 if (atomic_inc_return(&file->sm_ref) > 1)
314 set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
317 if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) {
319 /* Keep the event disabled, when going to SOFT_MODE. */
321 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
323 if (trace_flags & TRACE_ITER_RECORD_CMD) {
324 tracing_start_cmdline_record();
325 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
327 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
329 tracing_stop_cmdline_record();
330 pr_info("event trace: Could not enable event "
334 set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
336 /* WAS_ENABLED gets set but never cleared. */
337 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
345 int trace_event_enable_disable(struct ftrace_event_file *file,
346 int enable, int soft_disable)
348 return __ftrace_event_enable_disable(file, enable, soft_disable);
351 static int ftrace_event_enable_disable(struct ftrace_event_file *file,
354 return __ftrace_event_enable_disable(file, enable, 0);
357 static void ftrace_clear_events(struct trace_array *tr)
359 struct ftrace_event_file *file;
361 mutex_lock(&event_mutex);
362 list_for_each_entry(file, &tr->events, list) {
363 ftrace_event_enable_disable(file, 0);
365 mutex_unlock(&event_mutex);
368 static void __put_system(struct event_subsystem *system)
370 struct event_filter *filter = system->filter;
372 WARN_ON_ONCE(system_refcount(system) == 0);
373 if (system_refcount_dec(system))
376 list_del(&system->list);
379 kfree(filter->filter_string);
382 if (system->ref_count & SYSTEM_FL_FREE_NAME)
387 static void __get_system(struct event_subsystem *system)
389 WARN_ON_ONCE(system_refcount(system) == 0);
390 system_refcount_inc(system);
393 static void __get_system_dir(struct ftrace_subsystem_dir *dir)
395 WARN_ON_ONCE(dir->ref_count == 0);
397 __get_system(dir->subsystem);
400 static void __put_system_dir(struct ftrace_subsystem_dir *dir)
402 WARN_ON_ONCE(dir->ref_count == 0);
403 /* If the subsystem is about to be freed, the dir must be too */
404 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
406 __put_system(dir->subsystem);
407 if (!--dir->ref_count)
411 static void put_system(struct ftrace_subsystem_dir *dir)
413 mutex_lock(&event_mutex);
414 __put_system_dir(dir);
415 mutex_unlock(&event_mutex);
418 static void remove_subsystem(struct ftrace_subsystem_dir *dir)
423 if (!--dir->nr_events) {
424 debugfs_remove_recursive(dir->entry);
425 list_del(&dir->list);
426 __put_system_dir(dir);
430 static void remove_event_file_dir(struct ftrace_event_file *file)
432 struct dentry *dir = file->dir;
433 struct dentry *child;
436 spin_lock(&dir->d_lock); /* probably unneeded */
437 list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
438 if (child->d_inode) /* probably unneeded */
439 child->d_inode->i_private = NULL;
441 spin_unlock(&dir->d_lock);
443 debugfs_remove_recursive(dir);
446 list_del(&file->list);
447 remove_subsystem(file->system);
448 kmem_cache_free(file_cachep, file);
452 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
455 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
456 const char *sub, const char *event, int set)
458 struct ftrace_event_file *file;
459 struct ftrace_event_call *call;
462 list_for_each_entry(file, &tr->events, list) {
464 call = file->event_call;
466 if (!call->name || !call->class || !call->class->reg)
469 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
473 strcmp(match, call->name) != 0 &&
474 strcmp(match, call->class->system) != 0)
477 if (sub && strcmp(sub, call->class->system) != 0)
480 if (event && strcmp(event, call->name) != 0)
483 ftrace_event_enable_disable(file, set);
491 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
492 const char *sub, const char *event, int set)
496 mutex_lock(&event_mutex);
497 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
498 mutex_unlock(&event_mutex);
503 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
505 char *event = NULL, *sub = NULL, *match;
508 * The buf format can be <subsystem>:<event-name>
509 * *:<event-name> means any event by that name.
510 * :<event-name> is the same.
512 * <subsystem>:* means all events in that subsystem
513 * <subsystem>: means the same.
515 * <name> (no ':') means all events in a subsystem with
516 * the name <name> or any event that matches <name>
519 match = strsep(&buf, ":");
525 if (!strlen(sub) || strcmp(sub, "*") == 0)
527 if (!strlen(event) || strcmp(event, "*") == 0)
531 return __ftrace_set_clr_event(tr, match, sub, event, set);
535 * trace_set_clr_event - enable or disable an event
536 * @system: system name to match (NULL for any system)
537 * @event: event name to match (NULL for all events, within system)
538 * @set: 1 to enable, 0 to disable
540 * This is a way for other parts of the kernel to enable or disable
543 * Returns 0 on success, -EINVAL if the parameters do not match any
546 int trace_set_clr_event(const char *system, const char *event, int set)
548 struct trace_array *tr = top_trace_array();
550 return __ftrace_set_clr_event(tr, NULL, system, event, set);
552 EXPORT_SYMBOL_GPL(trace_set_clr_event);
554 /* 128 should be much more than enough */
555 #define EVENT_BUF_SIZE 127
558 ftrace_event_write(struct file *file, const char __user *ubuf,
559 size_t cnt, loff_t *ppos)
561 struct trace_parser parser;
562 struct seq_file *m = file->private_data;
563 struct trace_array *tr = m->private;
569 ret = tracing_update_buffers();
573 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
576 read = trace_get_user(&parser, ubuf, cnt, ppos);
578 if (read >= 0 && trace_parser_loaded((&parser))) {
581 if (*parser.buffer == '!')
584 parser.buffer[parser.idx] = 0;
586 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
594 trace_parser_put(&parser);
600 t_next(struct seq_file *m, void *v, loff_t *pos)
602 struct ftrace_event_file *file = v;
603 struct ftrace_event_call *call;
604 struct trace_array *tr = m->private;
608 list_for_each_entry_continue(file, &tr->events, list) {
609 call = file->event_call;
611 * The ftrace subsystem is for showing formats only.
612 * They can not be enabled or disabled via the event files.
614 if (call->class && call->class->reg)
621 static void *t_start(struct seq_file *m, loff_t *pos)
623 struct ftrace_event_file *file;
624 struct trace_array *tr = m->private;
627 mutex_lock(&event_mutex);
629 file = list_entry(&tr->events, struct ftrace_event_file, list);
630 for (l = 0; l <= *pos; ) {
631 file = t_next(m, file, &l);
639 s_next(struct seq_file *m, void *v, loff_t *pos)
641 struct ftrace_event_file *file = v;
642 struct trace_array *tr = m->private;
646 list_for_each_entry_continue(file, &tr->events, list) {
647 if (file->flags & FTRACE_EVENT_FL_ENABLED)
654 static void *s_start(struct seq_file *m, loff_t *pos)
656 struct ftrace_event_file *file;
657 struct trace_array *tr = m->private;
660 mutex_lock(&event_mutex);
662 file = list_entry(&tr->events, struct ftrace_event_file, list);
663 for (l = 0; l <= *pos; ) {
664 file = s_next(m, file, &l);
671 static int t_show(struct seq_file *m, void *v)
673 struct ftrace_event_file *file = v;
674 struct ftrace_event_call *call = file->event_call;
676 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
677 seq_printf(m, "%s:", call->class->system);
678 seq_printf(m, "%s\n", call->name);
683 static void t_stop(struct seq_file *m, void *p)
685 mutex_unlock(&event_mutex);
689 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
692 struct ftrace_event_file *file;
696 mutex_lock(&event_mutex);
697 file = event_file_data(filp);
700 mutex_unlock(&event_mutex);
705 if (flags & FTRACE_EVENT_FL_ENABLED &&
706 !(flags & FTRACE_EVENT_FL_SOFT_DISABLED))
709 if (flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
710 flags & FTRACE_EVENT_FL_SOFT_MODE)
715 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
719 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
722 struct ftrace_event_file *file;
726 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
730 ret = tracing_update_buffers();
738 mutex_lock(&event_mutex);
739 file = event_file_data(filp);
741 ret = ftrace_event_enable_disable(file, val);
742 mutex_unlock(&event_mutex);
751 return ret ? ret : cnt;
755 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
758 const char set_to_char[4] = { '?', '0', '1', 'X' };
759 struct ftrace_subsystem_dir *dir = filp->private_data;
760 struct event_subsystem *system = dir->subsystem;
761 struct ftrace_event_call *call;
762 struct ftrace_event_file *file;
763 struct trace_array *tr = dir->tr;
768 mutex_lock(&event_mutex);
769 list_for_each_entry(file, &tr->events, list) {
770 call = file->event_call;
771 if (!call->name || !call->class || !call->class->reg)
774 if (system && strcmp(call->class->system, system->name) != 0)
778 * We need to find out if all the events are set
779 * or if all events or cleared, or if we have
782 set |= (1 << !!(file->flags & FTRACE_EVENT_FL_ENABLED));
785 * If we have a mixture, no need to look further.
790 mutex_unlock(&event_mutex);
792 buf[0] = set_to_char[set];
795 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
801 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
804 struct ftrace_subsystem_dir *dir = filp->private_data;
805 struct event_subsystem *system = dir->subsystem;
806 const char *name = NULL;
810 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
814 ret = tracing_update_buffers();
818 if (val != 0 && val != 1)
822 * Opening of "enable" adds a ref count to system,
823 * so the name is safe to use.
828 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
842 FORMAT_FIELD_SEPERATOR = 2,
846 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
848 struct ftrace_event_call *call = event_file_data(m->private);
849 struct list_head *common_head = &ftrace_common_fields;
850 struct list_head *head = trace_get_fields(call);
851 struct list_head *node = v;
855 switch ((unsigned long)v) {
860 case FORMAT_FIELD_SEPERATOR:
864 case FORMAT_PRINTFMT:
870 if (node == common_head)
871 return (void *)FORMAT_FIELD_SEPERATOR;
872 else if (node == head)
873 return (void *)FORMAT_PRINTFMT;
878 static int f_show(struct seq_file *m, void *v)
880 struct ftrace_event_call *call = event_file_data(m->private);
881 struct ftrace_event_field *field;
882 const char *array_descriptor;
884 switch ((unsigned long)v) {
886 seq_printf(m, "name: %s\n", call->name);
887 seq_printf(m, "ID: %d\n", call->event.type);
888 seq_printf(m, "format:\n");
891 case FORMAT_FIELD_SEPERATOR:
895 case FORMAT_PRINTFMT:
896 seq_printf(m, "\nprint fmt: %s\n",
901 field = list_entry(v, struct ftrace_event_field, link);
903 * Smartly shows the array type(except dynamic array).
906 * If TYPE := TYPE[LEN], it is shown:
907 * field:TYPE VAR[LEN]
909 array_descriptor = strchr(field->type, '[');
911 if (!strncmp(field->type, "__data_loc", 10))
912 array_descriptor = NULL;
914 if (!array_descriptor)
915 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
916 field->type, field->name, field->offset,
917 field->size, !!field->is_signed);
919 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
920 (int)(array_descriptor - field->type),
921 field->type, field->name,
922 array_descriptor, field->offset,
923 field->size, !!field->is_signed);
928 static void *f_start(struct seq_file *m, loff_t *pos)
930 void *p = (void *)FORMAT_HEADER;
933 /* ->stop() is called even if ->start() fails */
934 mutex_lock(&event_mutex);
935 if (!event_file_data(m->private))
936 return ERR_PTR(-ENODEV);
938 while (l < *pos && p)
939 p = f_next(m, p, &l);
944 static void f_stop(struct seq_file *m, void *p)
946 mutex_unlock(&event_mutex);
949 static const struct seq_operations trace_format_seq_ops = {
956 static int trace_format_open(struct inode *inode, struct file *file)
961 ret = seq_open(file, &trace_format_seq_ops);
965 m = file->private_data;
972 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
974 int id = (long)event_file_data(filp);
984 len = sprintf(buf, "%d\n", id);
986 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
990 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
993 struct ftrace_event_file *file;
1000 s = kmalloc(sizeof(*s), GFP_KERNEL);
1007 mutex_lock(&event_mutex);
1008 file = event_file_data(filp);
1010 print_event_filter(file, s);
1011 mutex_unlock(&event_mutex);
1014 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1022 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1025 struct ftrace_event_file *file;
1029 if (cnt >= PAGE_SIZE)
1032 buf = (char *)__get_free_page(GFP_TEMPORARY);
1036 if (copy_from_user(buf, ubuf, cnt)) {
1037 free_page((unsigned long) buf);
1042 mutex_lock(&event_mutex);
1043 file = event_file_data(filp);
1045 err = apply_event_filter(file, buf);
1046 mutex_unlock(&event_mutex);
1048 free_page((unsigned long) buf);
1057 static LIST_HEAD(event_subsystems);
1059 static int subsystem_open(struct inode *inode, struct file *filp)
1061 struct event_subsystem *system = NULL;
1062 struct ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1063 struct trace_array *tr;
1066 if (tracing_is_disabled())
1069 /* Make sure the system still exists */
1070 mutex_lock(&trace_types_lock);
1071 mutex_lock(&event_mutex);
1072 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1073 list_for_each_entry(dir, &tr->systems, list) {
1074 if (dir == inode->i_private) {
1075 /* Don't open systems with no events */
1076 if (dir->nr_events) {
1077 __get_system_dir(dir);
1078 system = dir->subsystem;
1085 mutex_unlock(&event_mutex);
1086 mutex_unlock(&trace_types_lock);
1091 /* Some versions of gcc think dir can be uninitialized here */
1094 /* Still need to increment the ref count of the system */
1095 if (trace_array_get(tr) < 0) {
1100 ret = tracing_open_generic(inode, filp);
1102 trace_array_put(tr);
1109 static int system_tr_open(struct inode *inode, struct file *filp)
1111 struct ftrace_subsystem_dir *dir;
1112 struct trace_array *tr = inode->i_private;
1115 if (tracing_is_disabled())
1118 if (trace_array_get(tr) < 0)
1121 /* Make a temporary dir that has no system but points to tr */
1122 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1124 trace_array_put(tr);
1130 ret = tracing_open_generic(inode, filp);
1132 trace_array_put(tr);
1137 filp->private_data = dir;
1142 static int subsystem_release(struct inode *inode, struct file *file)
1144 struct ftrace_subsystem_dir *dir = file->private_data;
1146 trace_array_put(dir->tr);
1149 * If dir->subsystem is NULL, then this is a temporary
1150 * descriptor that was made for a trace_array to enable
1162 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1165 struct ftrace_subsystem_dir *dir = filp->private_data;
1166 struct event_subsystem *system = dir->subsystem;
1167 struct trace_seq *s;
1173 s = kmalloc(sizeof(*s), GFP_KERNEL);
1179 print_subsystem_event_filter(system, s);
1180 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1188 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1191 struct ftrace_subsystem_dir *dir = filp->private_data;
1195 if (cnt >= PAGE_SIZE)
1198 buf = (char *)__get_free_page(GFP_TEMPORARY);
1202 if (copy_from_user(buf, ubuf, cnt)) {
1203 free_page((unsigned long) buf);
1208 err = apply_subsystem_event_filter(dir, buf);
1209 free_page((unsigned long) buf);
1219 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1221 int (*func)(struct trace_seq *s) = filp->private_data;
1222 struct trace_seq *s;
1228 s = kmalloc(sizeof(*s), GFP_KERNEL);
1235 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1242 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1243 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1244 static int ftrace_event_release(struct inode *inode, struct file *file);
1246 static const struct seq_operations show_event_seq_ops = {
1253 static const struct seq_operations show_set_event_seq_ops = {
1260 static const struct file_operations ftrace_avail_fops = {
1261 .open = ftrace_event_avail_open,
1263 .llseek = seq_lseek,
1264 .release = seq_release,
1267 static const struct file_operations ftrace_set_event_fops = {
1268 .open = ftrace_event_set_open,
1270 .write = ftrace_event_write,
1271 .llseek = seq_lseek,
1272 .release = ftrace_event_release,
1275 static const struct file_operations ftrace_enable_fops = {
1276 .open = tracing_open_generic,
1277 .read = event_enable_read,
1278 .write = event_enable_write,
1279 .llseek = default_llseek,
1282 static const struct file_operations ftrace_event_format_fops = {
1283 .open = trace_format_open,
1285 .llseek = seq_lseek,
1286 .release = seq_release,
1289 static const struct file_operations ftrace_event_id_fops = {
1290 .read = event_id_read,
1291 .llseek = default_llseek,
1294 static const struct file_operations ftrace_event_filter_fops = {
1295 .open = tracing_open_generic,
1296 .read = event_filter_read,
1297 .write = event_filter_write,
1298 .llseek = default_llseek,
1301 static const struct file_operations ftrace_subsystem_filter_fops = {
1302 .open = subsystem_open,
1303 .read = subsystem_filter_read,
1304 .write = subsystem_filter_write,
1305 .llseek = default_llseek,
1306 .release = subsystem_release,
1309 static const struct file_operations ftrace_system_enable_fops = {
1310 .open = subsystem_open,
1311 .read = system_enable_read,
1312 .write = system_enable_write,
1313 .llseek = default_llseek,
1314 .release = subsystem_release,
1317 static const struct file_operations ftrace_tr_enable_fops = {
1318 .open = system_tr_open,
1319 .read = system_enable_read,
1320 .write = system_enable_write,
1321 .llseek = default_llseek,
1322 .release = subsystem_release,
1325 static const struct file_operations ftrace_show_header_fops = {
1326 .open = tracing_open_generic,
1327 .read = show_header,
1328 .llseek = default_llseek,
1332 ftrace_event_open(struct inode *inode, struct file *file,
1333 const struct seq_operations *seq_ops)
1338 ret = seq_open(file, seq_ops);
1341 m = file->private_data;
1342 /* copy tr over to seq ops */
1343 m->private = inode->i_private;
1348 static int ftrace_event_release(struct inode *inode, struct file *file)
1350 struct trace_array *tr = inode->i_private;
1352 trace_array_put(tr);
1354 return seq_release(inode, file);
1358 ftrace_event_avail_open(struct inode *inode, struct file *file)
1360 const struct seq_operations *seq_ops = &show_event_seq_ops;
1362 return ftrace_event_open(inode, file, seq_ops);
1366 ftrace_event_set_open(struct inode *inode, struct file *file)
1368 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1369 struct trace_array *tr = inode->i_private;
1372 if (trace_array_get(tr) < 0)
1375 if ((file->f_mode & FMODE_WRITE) &&
1376 (file->f_flags & O_TRUNC))
1377 ftrace_clear_events(tr);
1379 ret = ftrace_event_open(inode, file, seq_ops);
1381 trace_array_put(tr);
1385 static struct event_subsystem *
1386 create_new_subsystem(const char *name)
1388 struct event_subsystem *system;
1390 /* need to create new entry */
1391 system = kmalloc(sizeof(*system), GFP_KERNEL);
1395 system->ref_count = 1;
1397 /* Only allocate if dynamic (kprobes and modules) */
1398 if (!core_kernel_data((unsigned long)name)) {
1399 system->ref_count |= SYSTEM_FL_FREE_NAME;
1400 system->name = kstrdup(name, GFP_KERNEL);
1404 system->name = name;
1406 system->filter = NULL;
1408 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1409 if (!system->filter)
1412 list_add(&system->list, &event_subsystems);
1417 if (system->ref_count & SYSTEM_FL_FREE_NAME)
1418 kfree(system->name);
1423 static struct dentry *
1424 event_subsystem_dir(struct trace_array *tr, const char *name,
1425 struct ftrace_event_file *file, struct dentry *parent)
1427 struct ftrace_subsystem_dir *dir;
1428 struct event_subsystem *system;
1429 struct dentry *entry;
1431 /* First see if we did not already create this dir */
1432 list_for_each_entry(dir, &tr->systems, list) {
1433 system = dir->subsystem;
1434 if (strcmp(system->name, name) == 0) {
1441 /* Now see if the system itself exists. */
1442 list_for_each_entry(system, &event_subsystems, list) {
1443 if (strcmp(system->name, name) == 0)
1446 /* Reset system variable when not found */
1447 if (&system->list == &event_subsystems)
1450 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1455 system = create_new_subsystem(name);
1459 __get_system(system);
1461 dir->entry = debugfs_create_dir(name, parent);
1463 pr_warning("Failed to create system directory %s\n", name);
1464 __put_system(system);
1471 dir->subsystem = system;
1474 entry = debugfs_create_file("filter", 0644, dir->entry, dir,
1475 &ftrace_subsystem_filter_fops);
1477 kfree(system->filter);
1478 system->filter = NULL;
1479 pr_warning("Could not create debugfs '%s/filter' entry\n", name);
1482 trace_create_file("enable", 0644, dir->entry, dir,
1483 &ftrace_system_enable_fops);
1485 list_add(&dir->list, &tr->systems);
1492 /* Only print this message if failed on memory allocation */
1493 if (!dir || !system)
1494 pr_warning("No memory to create event subsystem %s\n",
1500 event_create_dir(struct dentry *parent, struct ftrace_event_file *file)
1502 struct ftrace_event_call *call = file->event_call;
1503 struct trace_array *tr = file->tr;
1504 struct list_head *head;
1505 struct dentry *d_events;
1509 * If the trace point header did not define TRACE_SYSTEM
1510 * then the system would be called "TRACE_SYSTEM".
1512 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1513 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1519 file->dir = debugfs_create_dir(call->name, d_events);
1521 pr_warning("Could not create debugfs '%s' directory\n",
1526 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1527 trace_create_file("enable", 0644, file->dir, file,
1528 &ftrace_enable_fops);
1530 #ifdef CONFIG_PERF_EVENTS
1531 if (call->event.type && call->class->reg)
1532 trace_create_file("id", 0444, file->dir,
1533 (void *)(long)call->event.type,
1534 &ftrace_event_id_fops);
1538 * Other events may have the same class. Only update
1539 * the fields if they are not already defined.
1541 head = trace_get_fields(call);
1542 if (list_empty(head)) {
1543 ret = call->class->define_fields(call);
1545 pr_warning("Could not initialize trace point"
1546 " events/%s\n", call->name);
1550 trace_create_file("filter", 0644, file->dir, file,
1551 &ftrace_event_filter_fops);
1553 trace_create_file("trigger", 0644, file->dir, file,
1554 &event_trigger_fops);
1556 trace_create_file("format", 0444, file->dir, call,
1557 &ftrace_event_format_fops);
1562 static void remove_event_from_tracers(struct ftrace_event_call *call)
1564 struct ftrace_event_file *file;
1565 struct trace_array *tr;
1567 do_for_each_event_file_safe(tr, file) {
1568 if (file->event_call != call)
1571 remove_event_file_dir(file);
1573 * The do_for_each_event_file_safe() is
1574 * a double loop. After finding the call for this
1575 * trace_array, we use break to jump to the next
1579 } while_for_each_event_file();
1582 static void event_remove(struct ftrace_event_call *call)
1584 struct trace_array *tr;
1585 struct ftrace_event_file *file;
1587 do_for_each_event_file(tr, file) {
1588 if (file->event_call != call)
1590 ftrace_event_enable_disable(file, 0);
1591 destroy_preds(file);
1593 * The do_for_each_event_file() is
1594 * a double loop. After finding the call for this
1595 * trace_array, we use break to jump to the next
1599 } while_for_each_event_file();
1601 if (call->event.funcs)
1602 __unregister_ftrace_event(&call->event);
1603 remove_event_from_tracers(call);
1604 list_del(&call->list);
1607 static int event_init(struct ftrace_event_call *call)
1611 if (WARN_ON(!call->name))
1614 if (call->class->raw_init) {
1615 ret = call->class->raw_init(call);
1616 if (ret < 0 && ret != -ENOSYS)
1617 pr_warn("Could not initialize trace events/%s\n",
1625 __register_event(struct ftrace_event_call *call, struct module *mod)
1629 ret = event_init(call);
1633 list_add(&call->list, &ftrace_events);
1639 static struct ftrace_event_file *
1640 trace_create_new_event(struct ftrace_event_call *call,
1641 struct trace_array *tr)
1643 struct ftrace_event_file *file;
1645 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
1649 file->event_call = call;
1651 atomic_set(&file->sm_ref, 0);
1652 atomic_set(&file->tm_ref, 0);
1653 INIT_LIST_HEAD(&file->triggers);
1654 list_add(&file->list, &tr->events);
1659 /* Add an event to a trace directory */
1661 __trace_add_new_event(struct ftrace_event_call *call, struct trace_array *tr)
1663 struct ftrace_event_file *file;
1665 file = trace_create_new_event(call, tr);
1669 return event_create_dir(tr->event_dir, file);
1673 * Just create a decriptor for early init. A descriptor is required
1674 * for enabling events at boot. We want to enable events before
1675 * the filesystem is initialized.
1678 __trace_early_add_new_event(struct ftrace_event_call *call,
1679 struct trace_array *tr)
1681 struct ftrace_event_file *file;
1683 file = trace_create_new_event(call, tr);
1690 struct ftrace_module_file_ops;
1691 static void __add_event_to_tracers(struct ftrace_event_call *call);
1693 /* Add an additional event_call dynamically */
1694 int trace_add_event_call(struct ftrace_event_call *call)
1697 mutex_lock(&trace_types_lock);
1698 mutex_lock(&event_mutex);
1700 ret = __register_event(call, NULL);
1702 __add_event_to_tracers(call);
1704 mutex_unlock(&event_mutex);
1705 mutex_unlock(&trace_types_lock);
1710 * Must be called under locking of trace_types_lock, event_mutex and
1713 static void __trace_remove_event_call(struct ftrace_event_call *call)
1716 trace_destroy_fields(call);
1717 destroy_call_preds(call);
1720 static int probe_remove_event_call(struct ftrace_event_call *call)
1722 struct trace_array *tr;
1723 struct ftrace_event_file *file;
1725 #ifdef CONFIG_PERF_EVENTS
1726 if (call->perf_refcount)
1729 do_for_each_event_file(tr, file) {
1730 if (file->event_call != call)
1733 * We can't rely on ftrace_event_enable_disable(enable => 0)
1734 * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
1735 * TRACE_REG_UNREGISTER.
1737 if (file->flags & FTRACE_EVENT_FL_ENABLED)
1740 * The do_for_each_event_file_safe() is
1741 * a double loop. After finding the call for this
1742 * trace_array, we use break to jump to the next
1746 } while_for_each_event_file();
1748 __trace_remove_event_call(call);
1753 /* Remove an event_call */
1754 int trace_remove_event_call(struct ftrace_event_call *call)
1758 mutex_lock(&trace_types_lock);
1759 mutex_lock(&event_mutex);
1760 down_write(&trace_event_sem);
1761 ret = probe_remove_event_call(call);
1762 up_write(&trace_event_sem);
1763 mutex_unlock(&event_mutex);
1764 mutex_unlock(&trace_types_lock);
1769 #define for_each_event(event, start, end) \
1770 for (event = start; \
1771 (unsigned long)event < (unsigned long)end; \
1774 #ifdef CONFIG_MODULES
1776 static void trace_module_add_events(struct module *mod)
1778 struct ftrace_event_call **call, **start, **end;
1780 if (!mod->num_trace_events)
1783 /* Don't add infrastructure for mods without tracepoints */
1784 if (trace_module_has_bad_taint(mod)) {
1785 pr_err("%s: module has bad taint, not creating trace events\n",
1790 start = mod->trace_events;
1791 end = mod->trace_events + mod->num_trace_events;
1793 for_each_event(call, start, end) {
1794 __register_event(*call, mod);
1795 __add_event_to_tracers(*call);
1799 static void trace_module_remove_events(struct module *mod)
1801 struct ftrace_event_call *call, *p;
1802 bool clear_trace = false;
1804 down_write(&trace_event_sem);
1805 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1806 if (call->mod == mod) {
1807 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
1809 __trace_remove_event_call(call);
1812 up_write(&trace_event_sem);
1815 * It is safest to reset the ring buffer if the module being unloaded
1816 * registered any events that were used. The only worry is if
1817 * a new module gets loaded, and takes on the same id as the events
1818 * of this module. When printing out the buffer, traced events left
1819 * over from this module may be passed to the new module events and
1820 * unexpected results may occur.
1823 tracing_reset_all_online_cpus();
1826 static int trace_module_notify(struct notifier_block *self,
1827 unsigned long val, void *data)
1829 struct module *mod = data;
1831 mutex_lock(&trace_types_lock);
1832 mutex_lock(&event_mutex);
1834 case MODULE_STATE_COMING:
1835 trace_module_add_events(mod);
1837 case MODULE_STATE_GOING:
1838 trace_module_remove_events(mod);
1841 mutex_unlock(&event_mutex);
1842 mutex_unlock(&trace_types_lock);
1847 static struct notifier_block trace_module_nb = {
1848 .notifier_call = trace_module_notify,
1851 #endif /* CONFIG_MODULES */
1853 /* Create a new event directory structure for a trace directory. */
1855 __trace_add_event_dirs(struct trace_array *tr)
1857 struct ftrace_event_call *call;
1860 list_for_each_entry(call, &ftrace_events, list) {
1861 ret = __trace_add_new_event(call, tr);
1863 pr_warning("Could not create directory for event %s\n",
1868 struct ftrace_event_file *
1869 find_event_file(struct trace_array *tr, const char *system, const char *event)
1871 struct ftrace_event_file *file;
1872 struct ftrace_event_call *call;
1874 list_for_each_entry(file, &tr->events, list) {
1876 call = file->event_call;
1878 if (!call->name || !call->class || !call->class->reg)
1881 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1884 if (strcmp(event, call->name) == 0 &&
1885 strcmp(system, call->class->system) == 0)
1891 #ifdef CONFIG_DYNAMIC_FTRACE
1894 #define ENABLE_EVENT_STR "enable_event"
1895 #define DISABLE_EVENT_STR "disable_event"
1897 struct event_probe_data {
1898 struct ftrace_event_file *file;
1899 unsigned long count;
1905 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1907 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1908 struct event_probe_data *data = *pdata;
1914 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1916 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1920 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1922 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1923 struct event_probe_data *data = *pdata;
1931 /* Skip if the event is in a state we want to switch to */
1932 if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
1935 if (data->count != -1)
1938 event_enable_probe(ip, parent_ip, _data);
1942 event_enable_print(struct seq_file *m, unsigned long ip,
1943 struct ftrace_probe_ops *ops, void *_data)
1945 struct event_probe_data *data = _data;
1947 seq_printf(m, "%ps:", (void *)ip);
1949 seq_printf(m, "%s:%s:%s",
1950 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
1951 data->file->event_call->class->system,
1952 data->file->event_call->name);
1954 if (data->count == -1)
1955 seq_printf(m, ":unlimited\n");
1957 seq_printf(m, ":count=%ld\n", data->count);
1963 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
1966 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1967 struct event_probe_data *data = *pdata;
1974 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
1977 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1978 struct event_probe_data *data = *pdata;
1980 if (WARN_ON_ONCE(data->ref <= 0))
1985 /* Remove the SOFT_MODE flag */
1986 __ftrace_event_enable_disable(data->file, 0, 1);
1987 module_put(data->file->event_call->mod);
1993 static struct ftrace_probe_ops event_enable_probe_ops = {
1994 .func = event_enable_probe,
1995 .print = event_enable_print,
1996 .init = event_enable_init,
1997 .free = event_enable_free,
2000 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2001 .func = event_enable_count_probe,
2002 .print = event_enable_print,
2003 .init = event_enable_init,
2004 .free = event_enable_free,
2007 static struct ftrace_probe_ops event_disable_probe_ops = {
2008 .func = event_enable_probe,
2009 .print = event_enable_print,
2010 .init = event_enable_init,
2011 .free = event_enable_free,
2014 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2015 .func = event_enable_count_probe,
2016 .print = event_enable_print,
2017 .init = event_enable_init,
2018 .free = event_enable_free,
2022 event_enable_func(struct ftrace_hash *hash,
2023 char *glob, char *cmd, char *param, int enabled)
2025 struct trace_array *tr = top_trace_array();
2026 struct ftrace_event_file *file;
2027 struct ftrace_probe_ops *ops;
2028 struct event_probe_data *data;
2035 /* hash funcs only work with set_ftrace_filter */
2036 if (!enabled || !param)
2039 system = strsep(¶m, ":");
2043 event = strsep(¶m, ":");
2045 mutex_lock(&event_mutex);
2048 file = find_event_file(tr, system, event);
2052 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2055 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2057 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2059 if (glob[0] == '!') {
2060 unregister_ftrace_function_probe_func(glob+1, ops);
2066 data = kzalloc(sizeof(*data), GFP_KERNEL);
2070 data->enable = enable;
2077 number = strsep(¶m, ":");
2080 if (!strlen(number))
2084 * We use the callback data field (which is a pointer)
2087 ret = kstrtoul(number, 0, &data->count);
2092 /* Don't let event modules unload while probe registered */
2093 ret = try_module_get(file->event_call->mod);
2099 ret = __ftrace_event_enable_disable(file, 1, 1);
2102 ret = register_ftrace_function_probe(glob, ops, data);
2104 * The above returns on success the # of functions enabled,
2105 * but if it didn't find any functions it returns zero.
2106 * Consider no functions a failure too.
2113 /* Just return zero, not the number of enabled functions */
2116 mutex_unlock(&event_mutex);
2120 __ftrace_event_enable_disable(file, 0, 1);
2122 module_put(file->event_call->mod);
2128 static struct ftrace_func_command event_enable_cmd = {
2129 .name = ENABLE_EVENT_STR,
2130 .func = event_enable_func,
2133 static struct ftrace_func_command event_disable_cmd = {
2134 .name = DISABLE_EVENT_STR,
2135 .func = event_enable_func,
2138 static __init int register_event_cmds(void)
2142 ret = register_ftrace_command(&event_enable_cmd);
2143 if (WARN_ON(ret < 0))
2145 ret = register_ftrace_command(&event_disable_cmd);
2146 if (WARN_ON(ret < 0))
2147 unregister_ftrace_command(&event_enable_cmd);
2151 static inline int register_event_cmds(void) { return 0; }
2152 #endif /* CONFIG_DYNAMIC_FTRACE */
2155 * The top level array has already had its ftrace_event_file
2156 * descriptors created in order to allow for early events to
2157 * be recorded. This function is called after the debugfs has been
2158 * initialized, and we now have to create the files associated
2162 __trace_early_add_event_dirs(struct trace_array *tr)
2164 struct ftrace_event_file *file;
2168 list_for_each_entry(file, &tr->events, list) {
2169 ret = event_create_dir(tr->event_dir, file);
2171 pr_warning("Could not create directory for event %s\n",
2172 file->event_call->name);
2177 * For early boot up, the top trace array requires to have
2178 * a list of events that can be enabled. This must be done before
2179 * the filesystem is set up in order to allow events to be traced
2183 __trace_early_add_events(struct trace_array *tr)
2185 struct ftrace_event_call *call;
2188 list_for_each_entry(call, &ftrace_events, list) {
2189 /* Early boot up should not have any modules loaded */
2190 if (WARN_ON_ONCE(call->mod))
2193 ret = __trace_early_add_new_event(call, tr);
2195 pr_warning("Could not create early event %s\n",
2200 /* Remove the event directory structure for a trace directory. */
2202 __trace_remove_event_dirs(struct trace_array *tr)
2204 struct ftrace_event_file *file, *next;
2206 list_for_each_entry_safe(file, next, &tr->events, list)
2207 remove_event_file_dir(file);
2210 static void __add_event_to_tracers(struct ftrace_event_call *call)
2212 struct trace_array *tr;
2214 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2215 __trace_add_new_event(call, tr);
2218 extern struct ftrace_event_call *__start_ftrace_events[];
2219 extern struct ftrace_event_call *__stop_ftrace_events[];
2221 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2223 static __init int setup_trace_event(char *str)
2225 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2226 ring_buffer_expanded = true;
2227 tracing_selftest_disabled = true;
2231 __setup("trace_event=", setup_trace_event);
2233 /* Expects to have event_mutex held when called */
2235 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2237 struct dentry *d_events;
2238 struct dentry *entry;
2240 entry = debugfs_create_file("set_event", 0644, parent,
2241 tr, &ftrace_set_event_fops);
2243 pr_warning("Could not create debugfs 'set_event' entry\n");
2247 d_events = debugfs_create_dir("events", parent);
2249 pr_warning("Could not create debugfs 'events' directory\n");
2253 /* ring buffer internal formats */
2254 trace_create_file("header_page", 0444, d_events,
2255 ring_buffer_print_page_header,
2256 &ftrace_show_header_fops);
2258 trace_create_file("header_event", 0444, d_events,
2259 ring_buffer_print_entry_header,
2260 &ftrace_show_header_fops);
2262 trace_create_file("enable", 0644, d_events,
2263 tr, &ftrace_tr_enable_fops);
2265 tr->event_dir = d_events;
2271 * event_trace_add_tracer - add a instance of a trace_array to events
2272 * @parent: The parent dentry to place the files/directories for events in
2273 * @tr: The trace array associated with these events
2275 * When a new instance is created, it needs to set up its events
2276 * directory, as well as other files associated with events. It also
2277 * creates the event hierachry in the @parent/events directory.
2279 * Returns 0 on success.
2281 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2285 mutex_lock(&event_mutex);
2287 ret = create_event_toplevel_files(parent, tr);
2291 down_write(&trace_event_sem);
2292 __trace_add_event_dirs(tr);
2293 up_write(&trace_event_sem);
2296 mutex_unlock(&event_mutex);
2302 * The top trace array already had its file descriptors created.
2303 * Now the files themselves need to be created.
2306 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2310 mutex_lock(&event_mutex);
2312 ret = create_event_toplevel_files(parent, tr);
2316 down_write(&trace_event_sem);
2317 __trace_early_add_event_dirs(tr);
2318 up_write(&trace_event_sem);
2321 mutex_unlock(&event_mutex);
2326 int event_trace_del_tracer(struct trace_array *tr)
2328 mutex_lock(&event_mutex);
2330 /* Disable any event triggers and associated soft-disabled events */
2331 clear_event_triggers(tr);
2333 /* Disable any running events */
2334 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
2336 /* Access to events are within rcu_read_lock_sched() */
2337 synchronize_sched();
2339 down_write(&trace_event_sem);
2340 __trace_remove_event_dirs(tr);
2341 debugfs_remove_recursive(tr->event_dir);
2342 up_write(&trace_event_sem);
2344 tr->event_dir = NULL;
2346 mutex_unlock(&event_mutex);
2351 static __init int event_trace_memsetup(void)
2353 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
2354 file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC);
2358 static __init int event_trace_enable(void)
2360 struct trace_array *tr = top_trace_array();
2361 struct ftrace_event_call **iter, *call;
2362 char *buf = bootup_event_buf;
2366 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
2369 ret = event_init(call);
2371 list_add(&call->list, &ftrace_events);
2375 * We need the top trace array to have a working set of trace
2376 * points at early init, before the debug files and directories
2377 * are created. Create the file entries now, and attach them
2378 * to the actual file dentries later.
2380 __trace_early_add_events(tr);
2383 token = strsep(&buf, ",");
2390 ret = ftrace_set_clr_event(tr, token, 1);
2392 pr_warn("Failed to enable trace event: %s\n", token);
2395 trace_printk_start_comm();
2397 register_event_cmds();
2399 register_trigger_cmds();
2404 static __init int event_trace_init(void)
2406 struct trace_array *tr;
2407 struct dentry *d_tracer;
2408 struct dentry *entry;
2411 tr = top_trace_array();
2413 d_tracer = tracing_init_dentry();
2417 entry = debugfs_create_file("available_events", 0444, d_tracer,
2418 tr, &ftrace_avail_fops);
2420 pr_warning("Could not create debugfs "
2421 "'available_events' entry\n");
2423 if (trace_define_common_fields())
2424 pr_warning("tracing: Failed to allocate common fields");
2426 ret = early_event_add_tracer(d_tracer, tr);
2430 #ifdef CONFIG_MODULES
2431 ret = register_module_notifier(&trace_module_nb);
2433 pr_warning("Failed to register trace events module notifier\n");
2437 early_initcall(event_trace_memsetup);
2438 core_initcall(event_trace_enable);
2439 fs_initcall(event_trace_init);
2441 #ifdef CONFIG_FTRACE_STARTUP_TEST
2443 static DEFINE_SPINLOCK(test_spinlock);
2444 static DEFINE_SPINLOCK(test_spinlock_irq);
2445 static DEFINE_MUTEX(test_mutex);
2447 static __init void test_work(struct work_struct *dummy)
2449 spin_lock(&test_spinlock);
2450 spin_lock_irq(&test_spinlock_irq);
2452 spin_unlock_irq(&test_spinlock_irq);
2453 spin_unlock(&test_spinlock);
2455 mutex_lock(&test_mutex);
2457 mutex_unlock(&test_mutex);
2460 static __init int event_test_thread(void *unused)
2464 test_malloc = kmalloc(1234, GFP_KERNEL);
2466 pr_info("failed to kmalloc\n");
2468 schedule_on_each_cpu(test_work);
2472 set_current_state(TASK_INTERRUPTIBLE);
2473 while (!kthread_should_stop())
2480 * Do various things that may trigger events.
2482 static __init void event_test_stuff(void)
2484 struct task_struct *test_thread;
2486 test_thread = kthread_run(event_test_thread, NULL, "test-events");
2488 kthread_stop(test_thread);
2492 * For every trace event defined, we will test each trace point separately,
2493 * and then by groups, and finally all trace points.
2495 static __init void event_trace_self_tests(void)
2497 struct ftrace_subsystem_dir *dir;
2498 struct ftrace_event_file *file;
2499 struct ftrace_event_call *call;
2500 struct event_subsystem *system;
2501 struct trace_array *tr;
2504 tr = top_trace_array();
2506 pr_info("Running tests on trace events:\n");
2508 list_for_each_entry(file, &tr->events, list) {
2510 call = file->event_call;
2512 /* Only test those that have a probe */
2513 if (!call->class || !call->class->probe)
2517 * Testing syscall events here is pretty useless, but
2518 * we still do it if configured. But this is time consuming.
2519 * What we really need is a user thread to perform the
2520 * syscalls as we test.
2522 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
2523 if (call->class->system &&
2524 strcmp(call->class->system, "syscalls") == 0)
2528 pr_info("Testing event %s: ", call->name);
2531 * If an event is already enabled, someone is using
2532 * it and the self test should not be on.
2534 if (file->flags & FTRACE_EVENT_FL_ENABLED) {
2535 pr_warning("Enabled event during self test!\n");
2540 ftrace_event_enable_disable(file, 1);
2542 ftrace_event_enable_disable(file, 0);
2547 /* Now test at the sub system level */
2549 pr_info("Running tests on trace event systems:\n");
2551 list_for_each_entry(dir, &tr->systems, list) {
2553 system = dir->subsystem;
2555 /* the ftrace system is special, skip it */
2556 if (strcmp(system->name, "ftrace") == 0)
2559 pr_info("Testing event system %s: ", system->name);
2561 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
2562 if (WARN_ON_ONCE(ret)) {
2563 pr_warning("error enabling system %s\n",
2570 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
2571 if (WARN_ON_ONCE(ret)) {
2572 pr_warning("error disabling system %s\n",
2580 /* Test with all events enabled */
2582 pr_info("Running tests on all trace events:\n");
2583 pr_info("Testing all events: ");
2585 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
2586 if (WARN_ON_ONCE(ret)) {
2587 pr_warning("error enabling all events\n");
2594 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
2595 if (WARN_ON_ONCE(ret)) {
2596 pr_warning("error disabling all events\n");
2603 #ifdef CONFIG_FUNCTION_TRACER
2605 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
2608 function_test_events_call(unsigned long ip, unsigned long parent_ip,
2609 struct ftrace_ops *op, struct pt_regs *pt_regs)
2611 struct ring_buffer_event *event;
2612 struct ring_buffer *buffer;
2613 struct ftrace_entry *entry;
2614 unsigned long flags;
2619 pc = preempt_count();
2620 preempt_disable_notrace();
2621 cpu = raw_smp_processor_id();
2622 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
2627 local_save_flags(flags);
2629 event = trace_current_buffer_lock_reserve(&buffer,
2630 TRACE_FN, sizeof(*entry),
2634 entry = ring_buffer_event_data(event);
2636 entry->parent_ip = parent_ip;
2638 trace_buffer_unlock_commit(buffer, event, flags, pc);
2641 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
2642 preempt_enable_notrace();
2645 static struct ftrace_ops trace_ops __initdata =
2647 .func = function_test_events_call,
2648 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
2651 static __init void event_trace_self_test_with_function(void)
2654 ret = register_ftrace_function(&trace_ops);
2655 if (WARN_ON(ret < 0)) {
2656 pr_info("Failed to enable function tracer for event tests\n");
2659 pr_info("Running tests again, along with the function tracer\n");
2660 event_trace_self_tests();
2661 unregister_ftrace_function(&trace_ops);
2664 static __init void event_trace_self_test_with_function(void)
2669 static __init int event_trace_self_tests_init(void)
2671 if (!tracing_selftest_disabled) {
2672 event_trace_self_tests();
2673 event_trace_self_test_with_function();
2679 late_initcall(event_trace_self_tests_init);