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 int ftrace_event_reg(struct ftrace_event_call *call,
192 enum trace_reg type, void *data)
194 struct ftrace_event_file *file = data;
197 case TRACE_REG_REGISTER:
198 return tracepoint_probe_register(call->name,
201 case TRACE_REG_UNREGISTER:
202 tracepoint_probe_unregister(call->name,
207 #ifdef CONFIG_PERF_EVENTS
208 case TRACE_REG_PERF_REGISTER:
209 return tracepoint_probe_register(call->name,
210 call->class->perf_probe,
212 case TRACE_REG_PERF_UNREGISTER:
213 tracepoint_probe_unregister(call->name,
214 call->class->perf_probe,
217 case TRACE_REG_PERF_OPEN:
218 case TRACE_REG_PERF_CLOSE:
219 case TRACE_REG_PERF_ADD:
220 case TRACE_REG_PERF_DEL:
226 EXPORT_SYMBOL_GPL(ftrace_event_reg);
228 void trace_event_enable_cmd_record(bool enable)
230 struct ftrace_event_file *file;
231 struct trace_array *tr;
233 mutex_lock(&event_mutex);
234 do_for_each_event_file(tr, file) {
236 if (!(file->flags & FTRACE_EVENT_FL_ENABLED))
240 tracing_start_cmdline_record();
241 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
243 tracing_stop_cmdline_record();
244 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
246 } while_for_each_event_file();
247 mutex_unlock(&event_mutex);
250 static int __ftrace_event_enable_disable(struct ftrace_event_file *file,
251 int enable, int soft_disable)
253 struct ftrace_event_call *call = file->event_call;
260 * When soft_disable is set and enable is cleared, the sm_ref
261 * reference counter is decremented. If it reaches 0, we want
262 * to clear the SOFT_DISABLED flag but leave the event in the
263 * state that it was. That is, if the event was enabled and
264 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
265 * is set we do not want the event to be enabled before we
268 * When soft_disable is not set but the SOFT_MODE flag is,
269 * we do nothing. Do not disable the tracepoint, otherwise
270 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
273 if (atomic_dec_return(&file->sm_ref) > 0)
275 disable = file->flags & FTRACE_EVENT_FL_SOFT_DISABLED;
276 clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
278 disable = !(file->flags & FTRACE_EVENT_FL_SOFT_MODE);
280 if (disable && (file->flags & FTRACE_EVENT_FL_ENABLED)) {
281 clear_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
282 if (file->flags & FTRACE_EVENT_FL_RECORDED_CMD) {
283 tracing_stop_cmdline_record();
284 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
286 call->class->reg(call, TRACE_REG_UNREGISTER, file);
288 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
289 if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
290 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
292 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
296 * When soft_disable is set and enable is set, we want to
297 * register the tracepoint for the event, but leave the event
298 * as is. That means, if the event was already enabled, we do
299 * nothing (but set SOFT_MODE). If the event is disabled, we
300 * set SOFT_DISABLED before enabling the event tracepoint, so
301 * it still seems to be disabled.
304 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
306 if (atomic_inc_return(&file->sm_ref) > 1)
308 set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
311 if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) {
313 /* Keep the event disabled, when going to SOFT_MODE. */
315 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
317 if (trace_flags & TRACE_ITER_RECORD_CMD) {
318 tracing_start_cmdline_record();
319 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
321 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
323 tracing_stop_cmdline_record();
324 pr_info("event trace: Could not enable event "
328 set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
330 /* WAS_ENABLED gets set but never cleared. */
331 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
339 int trace_event_enable_disable(struct ftrace_event_file *file,
340 int enable, int soft_disable)
342 return __ftrace_event_enable_disable(file, enable, soft_disable);
345 static int ftrace_event_enable_disable(struct ftrace_event_file *file,
348 return __ftrace_event_enable_disable(file, enable, 0);
351 static void ftrace_clear_events(struct trace_array *tr)
353 struct ftrace_event_file *file;
355 mutex_lock(&event_mutex);
356 list_for_each_entry(file, &tr->events, list) {
357 ftrace_event_enable_disable(file, 0);
359 mutex_unlock(&event_mutex);
362 static void __put_system(struct event_subsystem *system)
364 struct event_filter *filter = system->filter;
366 WARN_ON_ONCE(system_refcount(system) == 0);
367 if (system_refcount_dec(system))
370 list_del(&system->list);
373 kfree(filter->filter_string);
376 if (system->ref_count & SYSTEM_FL_FREE_NAME)
381 static void __get_system(struct event_subsystem *system)
383 WARN_ON_ONCE(system_refcount(system) == 0);
384 system_refcount_inc(system);
387 static void __get_system_dir(struct ftrace_subsystem_dir *dir)
389 WARN_ON_ONCE(dir->ref_count == 0);
391 __get_system(dir->subsystem);
394 static void __put_system_dir(struct ftrace_subsystem_dir *dir)
396 WARN_ON_ONCE(dir->ref_count == 0);
397 /* If the subsystem is about to be freed, the dir must be too */
398 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
400 __put_system(dir->subsystem);
401 if (!--dir->ref_count)
405 static void put_system(struct ftrace_subsystem_dir *dir)
407 mutex_lock(&event_mutex);
408 __put_system_dir(dir);
409 mutex_unlock(&event_mutex);
412 static void remove_subsystem(struct ftrace_subsystem_dir *dir)
417 if (!--dir->nr_events) {
418 debugfs_remove_recursive(dir->entry);
419 list_del(&dir->list);
420 __put_system_dir(dir);
424 static void remove_event_file_dir(struct ftrace_event_file *file)
426 struct dentry *dir = file->dir;
427 struct dentry *child;
430 spin_lock(&dir->d_lock); /* probably unneeded */
431 list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
432 if (child->d_inode) /* probably unneeded */
433 child->d_inode->i_private = NULL;
435 spin_unlock(&dir->d_lock);
437 debugfs_remove_recursive(dir);
440 list_del(&file->list);
441 remove_subsystem(file->system);
442 free_event_filter(file->filter);
443 kmem_cache_free(file_cachep, file);
447 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
450 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
451 const char *sub, const char *event, int set)
453 struct ftrace_event_file *file;
454 struct ftrace_event_call *call;
457 list_for_each_entry(file, &tr->events, list) {
459 call = file->event_call;
461 if (!call->name || !call->class || !call->class->reg)
464 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
468 strcmp(match, call->name) != 0 &&
469 strcmp(match, call->class->system) != 0)
472 if (sub && strcmp(sub, call->class->system) != 0)
475 if (event && strcmp(event, call->name) != 0)
478 ftrace_event_enable_disable(file, set);
486 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
487 const char *sub, const char *event, int set)
491 mutex_lock(&event_mutex);
492 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
493 mutex_unlock(&event_mutex);
498 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
500 char *event = NULL, *sub = NULL, *match;
503 * The buf format can be <subsystem>:<event-name>
504 * *:<event-name> means any event by that name.
505 * :<event-name> is the same.
507 * <subsystem>:* means all events in that subsystem
508 * <subsystem>: means the same.
510 * <name> (no ':') means all events in a subsystem with
511 * the name <name> or any event that matches <name>
514 match = strsep(&buf, ":");
520 if (!strlen(sub) || strcmp(sub, "*") == 0)
522 if (!strlen(event) || strcmp(event, "*") == 0)
526 return __ftrace_set_clr_event(tr, match, sub, event, set);
530 * trace_set_clr_event - enable or disable an event
531 * @system: system name to match (NULL for any system)
532 * @event: event name to match (NULL for all events, within system)
533 * @set: 1 to enable, 0 to disable
535 * This is a way for other parts of the kernel to enable or disable
538 * Returns 0 on success, -EINVAL if the parameters do not match any
541 int trace_set_clr_event(const char *system, const char *event, int set)
543 struct trace_array *tr = top_trace_array();
545 return __ftrace_set_clr_event(tr, NULL, system, event, set);
547 EXPORT_SYMBOL_GPL(trace_set_clr_event);
549 /* 128 should be much more than enough */
550 #define EVENT_BUF_SIZE 127
553 ftrace_event_write(struct file *file, const char __user *ubuf,
554 size_t cnt, loff_t *ppos)
556 struct trace_parser parser;
557 struct seq_file *m = file->private_data;
558 struct trace_array *tr = m->private;
564 ret = tracing_update_buffers();
568 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
571 read = trace_get_user(&parser, ubuf, cnt, ppos);
573 if (read >= 0 && trace_parser_loaded((&parser))) {
576 if (*parser.buffer == '!')
579 parser.buffer[parser.idx] = 0;
581 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
589 trace_parser_put(&parser);
595 t_next(struct seq_file *m, void *v, loff_t *pos)
597 struct ftrace_event_file *file = v;
598 struct ftrace_event_call *call;
599 struct trace_array *tr = m->private;
603 list_for_each_entry_continue(file, &tr->events, list) {
604 call = file->event_call;
606 * The ftrace subsystem is for showing formats only.
607 * They can not be enabled or disabled via the event files.
609 if (call->class && call->class->reg)
616 static void *t_start(struct seq_file *m, loff_t *pos)
618 struct ftrace_event_file *file;
619 struct trace_array *tr = m->private;
622 mutex_lock(&event_mutex);
624 file = list_entry(&tr->events, struct ftrace_event_file, list);
625 for (l = 0; l <= *pos; ) {
626 file = t_next(m, file, &l);
634 s_next(struct seq_file *m, void *v, loff_t *pos)
636 struct ftrace_event_file *file = v;
637 struct trace_array *tr = m->private;
641 list_for_each_entry_continue(file, &tr->events, list) {
642 if (file->flags & FTRACE_EVENT_FL_ENABLED)
649 static void *s_start(struct seq_file *m, loff_t *pos)
651 struct ftrace_event_file *file;
652 struct trace_array *tr = m->private;
655 mutex_lock(&event_mutex);
657 file = list_entry(&tr->events, struct ftrace_event_file, list);
658 for (l = 0; l <= *pos; ) {
659 file = s_next(m, file, &l);
666 static int t_show(struct seq_file *m, void *v)
668 struct ftrace_event_file *file = v;
669 struct ftrace_event_call *call = file->event_call;
671 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
672 seq_printf(m, "%s:", call->class->system);
673 seq_printf(m, "%s\n", call->name);
678 static void t_stop(struct seq_file *m, void *p)
680 mutex_unlock(&event_mutex);
684 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
687 struct ftrace_event_file *file;
691 mutex_lock(&event_mutex);
692 file = event_file_data(filp);
695 mutex_unlock(&event_mutex);
700 if (flags & FTRACE_EVENT_FL_ENABLED &&
701 !(flags & FTRACE_EVENT_FL_SOFT_DISABLED))
704 if (flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
705 flags & FTRACE_EVENT_FL_SOFT_MODE)
710 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
714 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
717 struct ftrace_event_file *file;
721 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
725 ret = tracing_update_buffers();
733 mutex_lock(&event_mutex);
734 file = event_file_data(filp);
736 ret = ftrace_event_enable_disable(file, val);
737 mutex_unlock(&event_mutex);
746 return ret ? ret : cnt;
750 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
753 const char set_to_char[4] = { '?', '0', '1', 'X' };
754 struct ftrace_subsystem_dir *dir = filp->private_data;
755 struct event_subsystem *system = dir->subsystem;
756 struct ftrace_event_call *call;
757 struct ftrace_event_file *file;
758 struct trace_array *tr = dir->tr;
763 mutex_lock(&event_mutex);
764 list_for_each_entry(file, &tr->events, list) {
765 call = file->event_call;
766 if (!call->name || !call->class || !call->class->reg)
769 if (system && strcmp(call->class->system, system->name) != 0)
773 * We need to find out if all the events are set
774 * or if all events or cleared, or if we have
777 set |= (1 << !!(file->flags & FTRACE_EVENT_FL_ENABLED));
780 * If we have a mixture, no need to look further.
785 mutex_unlock(&event_mutex);
787 buf[0] = set_to_char[set];
790 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
796 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
799 struct ftrace_subsystem_dir *dir = filp->private_data;
800 struct event_subsystem *system = dir->subsystem;
801 const char *name = NULL;
805 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
809 ret = tracing_update_buffers();
813 if (val != 0 && val != 1)
817 * Opening of "enable" adds a ref count to system,
818 * so the name is safe to use.
823 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
837 FORMAT_FIELD_SEPERATOR = 2,
841 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
843 struct ftrace_event_call *call = event_file_data(m->private);
844 struct list_head *common_head = &ftrace_common_fields;
845 struct list_head *head = trace_get_fields(call);
846 struct list_head *node = v;
850 switch ((unsigned long)v) {
855 case FORMAT_FIELD_SEPERATOR:
859 case FORMAT_PRINTFMT:
865 if (node == common_head)
866 return (void *)FORMAT_FIELD_SEPERATOR;
867 else if (node == head)
868 return (void *)FORMAT_PRINTFMT;
873 static int f_show(struct seq_file *m, void *v)
875 struct ftrace_event_call *call = event_file_data(m->private);
876 struct ftrace_event_field *field;
877 const char *array_descriptor;
879 switch ((unsigned long)v) {
881 seq_printf(m, "name: %s\n", call->name);
882 seq_printf(m, "ID: %d\n", call->event.type);
883 seq_printf(m, "format:\n");
886 case FORMAT_FIELD_SEPERATOR:
890 case FORMAT_PRINTFMT:
891 seq_printf(m, "\nprint fmt: %s\n",
896 field = list_entry(v, struct ftrace_event_field, link);
898 * Smartly shows the array type(except dynamic array).
901 * If TYPE := TYPE[LEN], it is shown:
902 * field:TYPE VAR[LEN]
904 array_descriptor = strchr(field->type, '[');
906 if (!strncmp(field->type, "__data_loc", 10))
907 array_descriptor = NULL;
909 if (!array_descriptor)
910 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
911 field->type, field->name, field->offset,
912 field->size, !!field->is_signed);
914 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
915 (int)(array_descriptor - field->type),
916 field->type, field->name,
917 array_descriptor, field->offset,
918 field->size, !!field->is_signed);
923 static void *f_start(struct seq_file *m, loff_t *pos)
925 void *p = (void *)FORMAT_HEADER;
928 /* ->stop() is called even if ->start() fails */
929 mutex_lock(&event_mutex);
930 if (!event_file_data(m->private))
931 return ERR_PTR(-ENODEV);
933 while (l < *pos && p)
934 p = f_next(m, p, &l);
939 static void f_stop(struct seq_file *m, void *p)
941 mutex_unlock(&event_mutex);
944 static const struct seq_operations trace_format_seq_ops = {
951 static int trace_format_open(struct inode *inode, struct file *file)
956 ret = seq_open(file, &trace_format_seq_ops);
960 m = file->private_data;
967 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
969 int id = (long)event_file_data(filp);
979 len = sprintf(buf, "%d\n", id);
981 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
985 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
988 struct ftrace_event_file *file;
995 s = kmalloc(sizeof(*s), GFP_KERNEL);
1002 mutex_lock(&event_mutex);
1003 file = event_file_data(filp);
1005 print_event_filter(file, s);
1006 mutex_unlock(&event_mutex);
1009 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1017 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1020 struct ftrace_event_file *file;
1024 if (cnt >= PAGE_SIZE)
1027 buf = (char *)__get_free_page(GFP_TEMPORARY);
1031 if (copy_from_user(buf, ubuf, cnt)) {
1032 free_page((unsigned long) buf);
1037 mutex_lock(&event_mutex);
1038 file = event_file_data(filp);
1040 err = apply_event_filter(file, buf);
1041 mutex_unlock(&event_mutex);
1043 free_page((unsigned long) buf);
1052 static LIST_HEAD(event_subsystems);
1054 static int subsystem_open(struct inode *inode, struct file *filp)
1056 struct event_subsystem *system = NULL;
1057 struct ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1058 struct trace_array *tr;
1061 if (tracing_is_disabled())
1064 /* Make sure the system still exists */
1065 mutex_lock(&trace_types_lock);
1066 mutex_lock(&event_mutex);
1067 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1068 list_for_each_entry(dir, &tr->systems, list) {
1069 if (dir == inode->i_private) {
1070 /* Don't open systems with no events */
1071 if (dir->nr_events) {
1072 __get_system_dir(dir);
1073 system = dir->subsystem;
1080 mutex_unlock(&event_mutex);
1081 mutex_unlock(&trace_types_lock);
1086 /* Some versions of gcc think dir can be uninitialized here */
1089 /* Still need to increment the ref count of the system */
1090 if (trace_array_get(tr) < 0) {
1095 ret = tracing_open_generic(inode, filp);
1097 trace_array_put(tr);
1104 static int system_tr_open(struct inode *inode, struct file *filp)
1106 struct ftrace_subsystem_dir *dir;
1107 struct trace_array *tr = inode->i_private;
1110 if (tracing_is_disabled())
1113 if (trace_array_get(tr) < 0)
1116 /* Make a temporary dir that has no system but points to tr */
1117 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1119 trace_array_put(tr);
1125 ret = tracing_open_generic(inode, filp);
1127 trace_array_put(tr);
1132 filp->private_data = dir;
1137 static int subsystem_release(struct inode *inode, struct file *file)
1139 struct ftrace_subsystem_dir *dir = file->private_data;
1141 trace_array_put(dir->tr);
1144 * If dir->subsystem is NULL, then this is a temporary
1145 * descriptor that was made for a trace_array to enable
1157 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1160 struct ftrace_subsystem_dir *dir = filp->private_data;
1161 struct event_subsystem *system = dir->subsystem;
1162 struct trace_seq *s;
1168 s = kmalloc(sizeof(*s), GFP_KERNEL);
1174 print_subsystem_event_filter(system, s);
1175 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1183 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1186 struct ftrace_subsystem_dir *dir = filp->private_data;
1190 if (cnt >= PAGE_SIZE)
1193 buf = (char *)__get_free_page(GFP_TEMPORARY);
1197 if (copy_from_user(buf, ubuf, cnt)) {
1198 free_page((unsigned long) buf);
1203 err = apply_subsystem_event_filter(dir, buf);
1204 free_page((unsigned long) buf);
1214 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1216 int (*func)(struct trace_seq *s) = filp->private_data;
1217 struct trace_seq *s;
1223 s = kmalloc(sizeof(*s), GFP_KERNEL);
1230 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1237 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1238 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1239 static int ftrace_event_release(struct inode *inode, struct file *file);
1241 static const struct seq_operations show_event_seq_ops = {
1248 static const struct seq_operations show_set_event_seq_ops = {
1255 static const struct file_operations ftrace_avail_fops = {
1256 .open = ftrace_event_avail_open,
1258 .llseek = seq_lseek,
1259 .release = seq_release,
1262 static const struct file_operations ftrace_set_event_fops = {
1263 .open = ftrace_event_set_open,
1265 .write = ftrace_event_write,
1266 .llseek = seq_lseek,
1267 .release = ftrace_event_release,
1270 static const struct file_operations ftrace_enable_fops = {
1271 .open = tracing_open_generic,
1272 .read = event_enable_read,
1273 .write = event_enable_write,
1274 .llseek = default_llseek,
1277 static const struct file_operations ftrace_event_format_fops = {
1278 .open = trace_format_open,
1280 .llseek = seq_lseek,
1281 .release = seq_release,
1284 static const struct file_operations ftrace_event_id_fops = {
1285 .read = event_id_read,
1286 .llseek = default_llseek,
1289 static const struct file_operations ftrace_event_filter_fops = {
1290 .open = tracing_open_generic,
1291 .read = event_filter_read,
1292 .write = event_filter_write,
1293 .llseek = default_llseek,
1296 static const struct file_operations ftrace_subsystem_filter_fops = {
1297 .open = subsystem_open,
1298 .read = subsystem_filter_read,
1299 .write = subsystem_filter_write,
1300 .llseek = default_llseek,
1301 .release = subsystem_release,
1304 static const struct file_operations ftrace_system_enable_fops = {
1305 .open = subsystem_open,
1306 .read = system_enable_read,
1307 .write = system_enable_write,
1308 .llseek = default_llseek,
1309 .release = subsystem_release,
1312 static const struct file_operations ftrace_tr_enable_fops = {
1313 .open = system_tr_open,
1314 .read = system_enable_read,
1315 .write = system_enable_write,
1316 .llseek = default_llseek,
1317 .release = subsystem_release,
1320 static const struct file_operations ftrace_show_header_fops = {
1321 .open = tracing_open_generic,
1322 .read = show_header,
1323 .llseek = default_llseek,
1327 ftrace_event_open(struct inode *inode, struct file *file,
1328 const struct seq_operations *seq_ops)
1333 ret = seq_open(file, seq_ops);
1336 m = file->private_data;
1337 /* copy tr over to seq ops */
1338 m->private = inode->i_private;
1343 static int ftrace_event_release(struct inode *inode, struct file *file)
1345 struct trace_array *tr = inode->i_private;
1347 trace_array_put(tr);
1349 return seq_release(inode, file);
1353 ftrace_event_avail_open(struct inode *inode, struct file *file)
1355 const struct seq_operations *seq_ops = &show_event_seq_ops;
1357 return ftrace_event_open(inode, file, seq_ops);
1361 ftrace_event_set_open(struct inode *inode, struct file *file)
1363 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1364 struct trace_array *tr = inode->i_private;
1367 if (trace_array_get(tr) < 0)
1370 if ((file->f_mode & FMODE_WRITE) &&
1371 (file->f_flags & O_TRUNC))
1372 ftrace_clear_events(tr);
1374 ret = ftrace_event_open(inode, file, seq_ops);
1376 trace_array_put(tr);
1380 static struct event_subsystem *
1381 create_new_subsystem(const char *name)
1383 struct event_subsystem *system;
1385 /* need to create new entry */
1386 system = kmalloc(sizeof(*system), GFP_KERNEL);
1390 system->ref_count = 1;
1392 /* Only allocate if dynamic (kprobes and modules) */
1393 if (!core_kernel_data((unsigned long)name)) {
1394 system->ref_count |= SYSTEM_FL_FREE_NAME;
1395 system->name = kstrdup(name, GFP_KERNEL);
1399 system->name = name;
1401 system->filter = NULL;
1403 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1404 if (!system->filter)
1407 list_add(&system->list, &event_subsystems);
1412 if (system->ref_count & SYSTEM_FL_FREE_NAME)
1413 kfree(system->name);
1418 static struct dentry *
1419 event_subsystem_dir(struct trace_array *tr, const char *name,
1420 struct ftrace_event_file *file, struct dentry *parent)
1422 struct ftrace_subsystem_dir *dir;
1423 struct event_subsystem *system;
1424 struct dentry *entry;
1426 /* First see if we did not already create this dir */
1427 list_for_each_entry(dir, &tr->systems, list) {
1428 system = dir->subsystem;
1429 if (strcmp(system->name, name) == 0) {
1436 /* Now see if the system itself exists. */
1437 list_for_each_entry(system, &event_subsystems, list) {
1438 if (strcmp(system->name, name) == 0)
1441 /* Reset system variable when not found */
1442 if (&system->list == &event_subsystems)
1445 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1450 system = create_new_subsystem(name);
1454 __get_system(system);
1456 dir->entry = debugfs_create_dir(name, parent);
1458 pr_warning("Failed to create system directory %s\n", name);
1459 __put_system(system);
1466 dir->subsystem = system;
1469 entry = debugfs_create_file("filter", 0644, dir->entry, dir,
1470 &ftrace_subsystem_filter_fops);
1472 kfree(system->filter);
1473 system->filter = NULL;
1474 pr_warning("Could not create debugfs '%s/filter' entry\n", name);
1477 trace_create_file("enable", 0644, dir->entry, dir,
1478 &ftrace_system_enable_fops);
1480 list_add(&dir->list, &tr->systems);
1487 /* Only print this message if failed on memory allocation */
1488 if (!dir || !system)
1489 pr_warning("No memory to create event subsystem %s\n",
1495 event_create_dir(struct dentry *parent, struct ftrace_event_file *file)
1497 struct ftrace_event_call *call = file->event_call;
1498 struct trace_array *tr = file->tr;
1499 struct list_head *head;
1500 struct dentry *d_events;
1504 * If the trace point header did not define TRACE_SYSTEM
1505 * then the system would be called "TRACE_SYSTEM".
1507 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1508 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1514 file->dir = debugfs_create_dir(call->name, d_events);
1516 pr_warning("Could not create debugfs '%s' directory\n",
1521 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1522 trace_create_file("enable", 0644, file->dir, file,
1523 &ftrace_enable_fops);
1525 #ifdef CONFIG_PERF_EVENTS
1526 if (call->event.type && call->class->reg)
1527 trace_create_file("id", 0444, file->dir,
1528 (void *)(long)call->event.type,
1529 &ftrace_event_id_fops);
1533 * Other events may have the same class. Only update
1534 * the fields if they are not already defined.
1536 head = trace_get_fields(call);
1537 if (list_empty(head)) {
1538 ret = call->class->define_fields(call);
1540 pr_warning("Could not initialize trace point"
1541 " events/%s\n", call->name);
1545 trace_create_file("filter", 0644, file->dir, file,
1546 &ftrace_event_filter_fops);
1548 trace_create_file("trigger", 0644, file->dir, file,
1549 &event_trigger_fops);
1551 trace_create_file("format", 0444, file->dir, call,
1552 &ftrace_event_format_fops);
1557 static void remove_event_from_tracers(struct ftrace_event_call *call)
1559 struct ftrace_event_file *file;
1560 struct trace_array *tr;
1562 do_for_each_event_file_safe(tr, file) {
1563 if (file->event_call != call)
1566 remove_event_file_dir(file);
1568 * The do_for_each_event_file_safe() is
1569 * a double loop. After finding the call for this
1570 * trace_array, we use break to jump to the next
1574 } while_for_each_event_file();
1577 static void event_remove(struct ftrace_event_call *call)
1579 struct trace_array *tr;
1580 struct ftrace_event_file *file;
1582 do_for_each_event_file(tr, file) {
1583 if (file->event_call != call)
1585 ftrace_event_enable_disable(file, 0);
1586 destroy_preds(file);
1588 * The do_for_each_event_file() is
1589 * a double loop. After finding the call for this
1590 * trace_array, we use break to jump to the next
1594 } while_for_each_event_file();
1596 if (call->event.funcs)
1597 __unregister_ftrace_event(&call->event);
1598 remove_event_from_tracers(call);
1599 list_del(&call->list);
1602 static int event_init(struct ftrace_event_call *call)
1606 if (WARN_ON(!call->name))
1609 if (call->class->raw_init) {
1610 ret = call->class->raw_init(call);
1611 if (ret < 0 && ret != -ENOSYS)
1612 pr_warn("Could not initialize trace events/%s\n",
1620 __register_event(struct ftrace_event_call *call, struct module *mod)
1624 ret = event_init(call);
1628 list_add(&call->list, &ftrace_events);
1634 static struct ftrace_event_file *
1635 trace_create_new_event(struct ftrace_event_call *call,
1636 struct trace_array *tr)
1638 struct ftrace_event_file *file;
1640 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
1644 file->event_call = call;
1646 atomic_set(&file->sm_ref, 0);
1647 atomic_set(&file->tm_ref, 0);
1648 INIT_LIST_HEAD(&file->triggers);
1649 list_add(&file->list, &tr->events);
1654 /* Add an event to a trace directory */
1656 __trace_add_new_event(struct ftrace_event_call *call, struct trace_array *tr)
1658 struct ftrace_event_file *file;
1660 file = trace_create_new_event(call, tr);
1664 return event_create_dir(tr->event_dir, file);
1668 * Just create a decriptor for early init. A descriptor is required
1669 * for enabling events at boot. We want to enable events before
1670 * the filesystem is initialized.
1673 __trace_early_add_new_event(struct ftrace_event_call *call,
1674 struct trace_array *tr)
1676 struct ftrace_event_file *file;
1678 file = trace_create_new_event(call, tr);
1685 struct ftrace_module_file_ops;
1686 static void __add_event_to_tracers(struct ftrace_event_call *call);
1688 /* Add an additional event_call dynamically */
1689 int trace_add_event_call(struct ftrace_event_call *call)
1692 mutex_lock(&trace_types_lock);
1693 mutex_lock(&event_mutex);
1695 ret = __register_event(call, NULL);
1697 __add_event_to_tracers(call);
1699 mutex_unlock(&event_mutex);
1700 mutex_unlock(&trace_types_lock);
1705 * Must be called under locking of trace_types_lock, event_mutex and
1708 static void __trace_remove_event_call(struct ftrace_event_call *call)
1711 trace_destroy_fields(call);
1712 destroy_call_preds(call);
1715 static int probe_remove_event_call(struct ftrace_event_call *call)
1717 struct trace_array *tr;
1718 struct ftrace_event_file *file;
1720 #ifdef CONFIG_PERF_EVENTS
1721 if (call->perf_refcount)
1724 do_for_each_event_file(tr, file) {
1725 if (file->event_call != call)
1728 * We can't rely on ftrace_event_enable_disable(enable => 0)
1729 * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
1730 * TRACE_REG_UNREGISTER.
1732 if (file->flags & FTRACE_EVENT_FL_ENABLED)
1735 * The do_for_each_event_file_safe() is
1736 * a double loop. After finding the call for this
1737 * trace_array, we use break to jump to the next
1741 } while_for_each_event_file();
1743 __trace_remove_event_call(call);
1748 /* Remove an event_call */
1749 int trace_remove_event_call(struct ftrace_event_call *call)
1753 mutex_lock(&trace_types_lock);
1754 mutex_lock(&event_mutex);
1755 down_write(&trace_event_sem);
1756 ret = probe_remove_event_call(call);
1757 up_write(&trace_event_sem);
1758 mutex_unlock(&event_mutex);
1759 mutex_unlock(&trace_types_lock);
1764 #define for_each_event(event, start, end) \
1765 for (event = start; \
1766 (unsigned long)event < (unsigned long)end; \
1769 #ifdef CONFIG_MODULES
1771 static void trace_module_add_events(struct module *mod)
1773 struct ftrace_event_call **call, **start, **end;
1775 if (!mod->num_trace_events)
1778 /* Don't add infrastructure for mods without tracepoints */
1779 if (trace_module_has_bad_taint(mod)) {
1780 pr_err("%s: module has bad taint, not creating trace events\n",
1785 start = mod->trace_events;
1786 end = mod->trace_events + mod->num_trace_events;
1788 for_each_event(call, start, end) {
1789 __register_event(*call, mod);
1790 __add_event_to_tracers(*call);
1794 static void trace_module_remove_events(struct module *mod)
1796 struct ftrace_event_call *call, *p;
1797 bool clear_trace = false;
1799 down_write(&trace_event_sem);
1800 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1801 if (call->mod == mod) {
1802 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
1804 __trace_remove_event_call(call);
1807 up_write(&trace_event_sem);
1810 * It is safest to reset the ring buffer if the module being unloaded
1811 * registered any events that were used. The only worry is if
1812 * a new module gets loaded, and takes on the same id as the events
1813 * of this module. When printing out the buffer, traced events left
1814 * over from this module may be passed to the new module events and
1815 * unexpected results may occur.
1818 tracing_reset_all_online_cpus();
1821 static int trace_module_notify(struct notifier_block *self,
1822 unsigned long val, void *data)
1824 struct module *mod = data;
1826 mutex_lock(&trace_types_lock);
1827 mutex_lock(&event_mutex);
1829 case MODULE_STATE_COMING:
1830 trace_module_add_events(mod);
1832 case MODULE_STATE_GOING:
1833 trace_module_remove_events(mod);
1836 mutex_unlock(&event_mutex);
1837 mutex_unlock(&trace_types_lock);
1842 static struct notifier_block trace_module_nb = {
1843 .notifier_call = trace_module_notify,
1846 #endif /* CONFIG_MODULES */
1848 /* Create a new event directory structure for a trace directory. */
1850 __trace_add_event_dirs(struct trace_array *tr)
1852 struct ftrace_event_call *call;
1855 list_for_each_entry(call, &ftrace_events, list) {
1856 ret = __trace_add_new_event(call, tr);
1858 pr_warning("Could not create directory for event %s\n",
1863 struct ftrace_event_file *
1864 find_event_file(struct trace_array *tr, const char *system, const char *event)
1866 struct ftrace_event_file *file;
1867 struct ftrace_event_call *call;
1869 list_for_each_entry(file, &tr->events, list) {
1871 call = file->event_call;
1873 if (!call->name || !call->class || !call->class->reg)
1876 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1879 if (strcmp(event, call->name) == 0 &&
1880 strcmp(system, call->class->system) == 0)
1886 #ifdef CONFIG_DYNAMIC_FTRACE
1889 #define ENABLE_EVENT_STR "enable_event"
1890 #define DISABLE_EVENT_STR "disable_event"
1892 struct event_probe_data {
1893 struct ftrace_event_file *file;
1894 unsigned long count;
1900 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1902 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1903 struct event_probe_data *data = *pdata;
1909 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1911 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1915 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1917 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1918 struct event_probe_data *data = *pdata;
1926 /* Skip if the event is in a state we want to switch to */
1927 if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
1930 if (data->count != -1)
1933 event_enable_probe(ip, parent_ip, _data);
1937 event_enable_print(struct seq_file *m, unsigned long ip,
1938 struct ftrace_probe_ops *ops, void *_data)
1940 struct event_probe_data *data = _data;
1942 seq_printf(m, "%ps:", (void *)ip);
1944 seq_printf(m, "%s:%s:%s",
1945 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
1946 data->file->event_call->class->system,
1947 data->file->event_call->name);
1949 if (data->count == -1)
1950 seq_printf(m, ":unlimited\n");
1952 seq_printf(m, ":count=%ld\n", data->count);
1958 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
1961 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1962 struct event_probe_data *data = *pdata;
1969 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
1972 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1973 struct event_probe_data *data = *pdata;
1975 if (WARN_ON_ONCE(data->ref <= 0))
1980 /* Remove the SOFT_MODE flag */
1981 __ftrace_event_enable_disable(data->file, 0, 1);
1982 module_put(data->file->event_call->mod);
1988 static struct ftrace_probe_ops event_enable_probe_ops = {
1989 .func = event_enable_probe,
1990 .print = event_enable_print,
1991 .init = event_enable_init,
1992 .free = event_enable_free,
1995 static struct ftrace_probe_ops event_enable_count_probe_ops = {
1996 .func = event_enable_count_probe,
1997 .print = event_enable_print,
1998 .init = event_enable_init,
1999 .free = event_enable_free,
2002 static struct ftrace_probe_ops event_disable_probe_ops = {
2003 .func = event_enable_probe,
2004 .print = event_enable_print,
2005 .init = event_enable_init,
2006 .free = event_enable_free,
2009 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2010 .func = event_enable_count_probe,
2011 .print = event_enable_print,
2012 .init = event_enable_init,
2013 .free = event_enable_free,
2017 event_enable_func(struct ftrace_hash *hash,
2018 char *glob, char *cmd, char *param, int enabled)
2020 struct trace_array *tr = top_trace_array();
2021 struct ftrace_event_file *file;
2022 struct ftrace_probe_ops *ops;
2023 struct event_probe_data *data;
2030 /* hash funcs only work with set_ftrace_filter */
2031 if (!enabled || !param)
2034 system = strsep(¶m, ":");
2038 event = strsep(¶m, ":");
2040 mutex_lock(&event_mutex);
2043 file = find_event_file(tr, system, event);
2047 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2050 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2052 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2054 if (glob[0] == '!') {
2055 unregister_ftrace_function_probe_func(glob+1, ops);
2061 data = kzalloc(sizeof(*data), GFP_KERNEL);
2065 data->enable = enable;
2072 number = strsep(¶m, ":");
2075 if (!strlen(number))
2079 * We use the callback data field (which is a pointer)
2082 ret = kstrtoul(number, 0, &data->count);
2087 /* Don't let event modules unload while probe registered */
2088 ret = try_module_get(file->event_call->mod);
2094 ret = __ftrace_event_enable_disable(file, 1, 1);
2097 ret = register_ftrace_function_probe(glob, ops, data);
2099 * The above returns on success the # of functions enabled,
2100 * but if it didn't find any functions it returns zero.
2101 * Consider no functions a failure too.
2108 /* Just return zero, not the number of enabled functions */
2111 mutex_unlock(&event_mutex);
2115 __ftrace_event_enable_disable(file, 0, 1);
2117 module_put(file->event_call->mod);
2123 static struct ftrace_func_command event_enable_cmd = {
2124 .name = ENABLE_EVENT_STR,
2125 .func = event_enable_func,
2128 static struct ftrace_func_command event_disable_cmd = {
2129 .name = DISABLE_EVENT_STR,
2130 .func = event_enable_func,
2133 static __init int register_event_cmds(void)
2137 ret = register_ftrace_command(&event_enable_cmd);
2138 if (WARN_ON(ret < 0))
2140 ret = register_ftrace_command(&event_disable_cmd);
2141 if (WARN_ON(ret < 0))
2142 unregister_ftrace_command(&event_enable_cmd);
2146 static inline int register_event_cmds(void) { return 0; }
2147 #endif /* CONFIG_DYNAMIC_FTRACE */
2150 * The top level array has already had its ftrace_event_file
2151 * descriptors created in order to allow for early events to
2152 * be recorded. This function is called after the debugfs has been
2153 * initialized, and we now have to create the files associated
2157 __trace_early_add_event_dirs(struct trace_array *tr)
2159 struct ftrace_event_file *file;
2163 list_for_each_entry(file, &tr->events, list) {
2164 ret = event_create_dir(tr->event_dir, file);
2166 pr_warning("Could not create directory for event %s\n",
2167 file->event_call->name);
2172 * For early boot up, the top trace array requires to have
2173 * a list of events that can be enabled. This must be done before
2174 * the filesystem is set up in order to allow events to be traced
2178 __trace_early_add_events(struct trace_array *tr)
2180 struct ftrace_event_call *call;
2183 list_for_each_entry(call, &ftrace_events, list) {
2184 /* Early boot up should not have any modules loaded */
2185 if (WARN_ON_ONCE(call->mod))
2188 ret = __trace_early_add_new_event(call, tr);
2190 pr_warning("Could not create early event %s\n",
2195 /* Remove the event directory structure for a trace directory. */
2197 __trace_remove_event_dirs(struct trace_array *tr)
2199 struct ftrace_event_file *file, *next;
2201 list_for_each_entry_safe(file, next, &tr->events, list)
2202 remove_event_file_dir(file);
2205 static void __add_event_to_tracers(struct ftrace_event_call *call)
2207 struct trace_array *tr;
2209 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2210 __trace_add_new_event(call, tr);
2213 extern struct ftrace_event_call *__start_ftrace_events[];
2214 extern struct ftrace_event_call *__stop_ftrace_events[];
2216 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2218 static __init int setup_trace_event(char *str)
2220 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2221 ring_buffer_expanded = true;
2222 tracing_selftest_disabled = true;
2226 __setup("trace_event=", setup_trace_event);
2228 /* Expects to have event_mutex held when called */
2230 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2232 struct dentry *d_events;
2233 struct dentry *entry;
2235 entry = debugfs_create_file("set_event", 0644, parent,
2236 tr, &ftrace_set_event_fops);
2238 pr_warning("Could not create debugfs 'set_event' entry\n");
2242 d_events = debugfs_create_dir("events", parent);
2244 pr_warning("Could not create debugfs 'events' directory\n");
2248 /* ring buffer internal formats */
2249 trace_create_file("header_page", 0444, d_events,
2250 ring_buffer_print_page_header,
2251 &ftrace_show_header_fops);
2253 trace_create_file("header_event", 0444, d_events,
2254 ring_buffer_print_entry_header,
2255 &ftrace_show_header_fops);
2257 trace_create_file("enable", 0644, d_events,
2258 tr, &ftrace_tr_enable_fops);
2260 tr->event_dir = d_events;
2266 * event_trace_add_tracer - add a instance of a trace_array to events
2267 * @parent: The parent dentry to place the files/directories for events in
2268 * @tr: The trace array associated with these events
2270 * When a new instance is created, it needs to set up its events
2271 * directory, as well as other files associated with events. It also
2272 * creates the event hierachry in the @parent/events directory.
2274 * Returns 0 on success.
2276 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2280 mutex_lock(&event_mutex);
2282 ret = create_event_toplevel_files(parent, tr);
2286 down_write(&trace_event_sem);
2287 __trace_add_event_dirs(tr);
2288 up_write(&trace_event_sem);
2291 mutex_unlock(&event_mutex);
2297 * The top trace array already had its file descriptors created.
2298 * Now the files themselves need to be created.
2301 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2305 mutex_lock(&event_mutex);
2307 ret = create_event_toplevel_files(parent, tr);
2311 down_write(&trace_event_sem);
2312 __trace_early_add_event_dirs(tr);
2313 up_write(&trace_event_sem);
2316 mutex_unlock(&event_mutex);
2321 int event_trace_del_tracer(struct trace_array *tr)
2323 mutex_lock(&event_mutex);
2325 /* Disable any event triggers and associated soft-disabled events */
2326 clear_event_triggers(tr);
2328 /* Disable any running events */
2329 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
2331 /* Access to events are within rcu_read_lock_sched() */
2332 synchronize_sched();
2334 down_write(&trace_event_sem);
2335 __trace_remove_event_dirs(tr);
2336 debugfs_remove_recursive(tr->event_dir);
2337 up_write(&trace_event_sem);
2339 tr->event_dir = NULL;
2341 mutex_unlock(&event_mutex);
2346 static __init int event_trace_memsetup(void)
2348 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
2349 file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC);
2353 static __init int event_trace_enable(void)
2355 struct trace_array *tr = top_trace_array();
2356 struct ftrace_event_call **iter, *call;
2357 char *buf = bootup_event_buf;
2361 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
2364 ret = event_init(call);
2366 list_add(&call->list, &ftrace_events);
2370 * We need the top trace array to have a working set of trace
2371 * points at early init, before the debug files and directories
2372 * are created. Create the file entries now, and attach them
2373 * to the actual file dentries later.
2375 __trace_early_add_events(tr);
2378 token = strsep(&buf, ",");
2385 ret = ftrace_set_clr_event(tr, token, 1);
2387 pr_warn("Failed to enable trace event: %s\n", token);
2390 trace_printk_start_comm();
2392 register_event_cmds();
2394 register_trigger_cmds();
2399 static __init int event_trace_init(void)
2401 struct trace_array *tr;
2402 struct dentry *d_tracer;
2403 struct dentry *entry;
2406 tr = top_trace_array();
2408 d_tracer = tracing_init_dentry();
2412 entry = debugfs_create_file("available_events", 0444, d_tracer,
2413 tr, &ftrace_avail_fops);
2415 pr_warning("Could not create debugfs "
2416 "'available_events' entry\n");
2418 if (trace_define_common_fields())
2419 pr_warning("tracing: Failed to allocate common fields");
2421 ret = early_event_add_tracer(d_tracer, tr);
2425 #ifdef CONFIG_MODULES
2426 ret = register_module_notifier(&trace_module_nb);
2428 pr_warning("Failed to register trace events module notifier\n");
2432 early_initcall(event_trace_memsetup);
2433 core_initcall(event_trace_enable);
2434 fs_initcall(event_trace_init);
2436 #ifdef CONFIG_FTRACE_STARTUP_TEST
2438 static DEFINE_SPINLOCK(test_spinlock);
2439 static DEFINE_SPINLOCK(test_spinlock_irq);
2440 static DEFINE_MUTEX(test_mutex);
2442 static __init void test_work(struct work_struct *dummy)
2444 spin_lock(&test_spinlock);
2445 spin_lock_irq(&test_spinlock_irq);
2447 spin_unlock_irq(&test_spinlock_irq);
2448 spin_unlock(&test_spinlock);
2450 mutex_lock(&test_mutex);
2452 mutex_unlock(&test_mutex);
2455 static __init int event_test_thread(void *unused)
2459 test_malloc = kmalloc(1234, GFP_KERNEL);
2461 pr_info("failed to kmalloc\n");
2463 schedule_on_each_cpu(test_work);
2467 set_current_state(TASK_INTERRUPTIBLE);
2468 while (!kthread_should_stop())
2475 * Do various things that may trigger events.
2477 static __init void event_test_stuff(void)
2479 struct task_struct *test_thread;
2481 test_thread = kthread_run(event_test_thread, NULL, "test-events");
2483 kthread_stop(test_thread);
2487 * For every trace event defined, we will test each trace point separately,
2488 * and then by groups, and finally all trace points.
2490 static __init void event_trace_self_tests(void)
2492 struct ftrace_subsystem_dir *dir;
2493 struct ftrace_event_file *file;
2494 struct ftrace_event_call *call;
2495 struct event_subsystem *system;
2496 struct trace_array *tr;
2499 tr = top_trace_array();
2501 pr_info("Running tests on trace events:\n");
2503 list_for_each_entry(file, &tr->events, list) {
2505 call = file->event_call;
2507 /* Only test those that have a probe */
2508 if (!call->class || !call->class->probe)
2512 * Testing syscall events here is pretty useless, but
2513 * we still do it if configured. But this is time consuming.
2514 * What we really need is a user thread to perform the
2515 * syscalls as we test.
2517 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
2518 if (call->class->system &&
2519 strcmp(call->class->system, "syscalls") == 0)
2523 pr_info("Testing event %s: ", call->name);
2526 * If an event is already enabled, someone is using
2527 * it and the self test should not be on.
2529 if (file->flags & FTRACE_EVENT_FL_ENABLED) {
2530 pr_warning("Enabled event during self test!\n");
2535 ftrace_event_enable_disable(file, 1);
2537 ftrace_event_enable_disable(file, 0);
2542 /* Now test at the sub system level */
2544 pr_info("Running tests on trace event systems:\n");
2546 list_for_each_entry(dir, &tr->systems, list) {
2548 system = dir->subsystem;
2550 /* the ftrace system is special, skip it */
2551 if (strcmp(system->name, "ftrace") == 0)
2554 pr_info("Testing event system %s: ", system->name);
2556 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
2557 if (WARN_ON_ONCE(ret)) {
2558 pr_warning("error enabling system %s\n",
2565 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
2566 if (WARN_ON_ONCE(ret)) {
2567 pr_warning("error disabling system %s\n",
2575 /* Test with all events enabled */
2577 pr_info("Running tests on all trace events:\n");
2578 pr_info("Testing all events: ");
2580 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
2581 if (WARN_ON_ONCE(ret)) {
2582 pr_warning("error enabling all events\n");
2589 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
2590 if (WARN_ON_ONCE(ret)) {
2591 pr_warning("error disabling all events\n");
2598 #ifdef CONFIG_FUNCTION_TRACER
2600 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
2603 function_test_events_call(unsigned long ip, unsigned long parent_ip,
2604 struct ftrace_ops *op, struct pt_regs *pt_regs)
2606 struct ring_buffer_event *event;
2607 struct ring_buffer *buffer;
2608 struct ftrace_entry *entry;
2609 unsigned long flags;
2614 pc = preempt_count();
2615 preempt_disable_notrace();
2616 cpu = raw_smp_processor_id();
2617 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
2622 local_save_flags(flags);
2624 event = trace_current_buffer_lock_reserve(&buffer,
2625 TRACE_FN, sizeof(*entry),
2629 entry = ring_buffer_event_data(event);
2631 entry->parent_ip = parent_ip;
2633 trace_buffer_unlock_commit(buffer, event, flags, pc);
2636 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
2637 preempt_enable_notrace();
2640 static struct ftrace_ops trace_ops __initdata =
2642 .func = function_test_events_call,
2643 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
2646 static __init void event_trace_self_test_with_function(void)
2649 ret = register_ftrace_function(&trace_ops);
2650 if (WARN_ON(ret < 0)) {
2651 pr_info("Failed to enable function tracer for event tests\n");
2654 pr_info("Running tests again, along with the function tracer\n");
2655 event_trace_self_tests();
2656 unregister_ftrace_function(&trace_ops);
2659 static __init void event_trace_self_test_with_function(void)
2664 static __init int event_trace_self_tests_init(void)
2666 if (!tracing_selftest_disabled) {
2667 event_trace_self_tests();
2668 event_trace_self_test_with_function();
2674 late_initcall(event_trace_self_tests_init);