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 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 *event_file_data(struct file *filp)
426 return ACCESS_ONCE(file_inode(filp)->i_private);
429 static void remove_event_file_dir(struct ftrace_event_file *file)
431 struct dentry *dir = file->dir;
432 struct dentry *child;
435 spin_lock(&dir->d_lock); /* probably unneeded */
436 list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
437 if (child->d_inode) /* probably unneeded */
438 child->d_inode->i_private = NULL;
440 spin_unlock(&dir->d_lock);
442 debugfs_remove_recursive(dir);
445 list_del(&file->list);
446 remove_subsystem(file->system);
447 kmem_cache_free(file_cachep, file);
451 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
454 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
455 const char *sub, const char *event, int set)
457 struct ftrace_event_file *file;
458 struct ftrace_event_call *call;
461 list_for_each_entry(file, &tr->events, list) {
463 call = file->event_call;
465 if (!call->name || !call->class || !call->class->reg)
468 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
472 strcmp(match, call->name) != 0 &&
473 strcmp(match, call->class->system) != 0)
476 if (sub && strcmp(sub, call->class->system) != 0)
479 if (event && strcmp(event, call->name) != 0)
482 ftrace_event_enable_disable(file, set);
490 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
491 const char *sub, const char *event, int set)
495 mutex_lock(&event_mutex);
496 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
497 mutex_unlock(&event_mutex);
502 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
504 char *event = NULL, *sub = NULL, *match;
507 * The buf format can be <subsystem>:<event-name>
508 * *:<event-name> means any event by that name.
509 * :<event-name> is the same.
511 * <subsystem>:* means all events in that subsystem
512 * <subsystem>: means the same.
514 * <name> (no ':') means all events in a subsystem with
515 * the name <name> or any event that matches <name>
518 match = strsep(&buf, ":");
524 if (!strlen(sub) || strcmp(sub, "*") == 0)
526 if (!strlen(event) || strcmp(event, "*") == 0)
530 return __ftrace_set_clr_event(tr, match, sub, event, set);
534 * trace_set_clr_event - enable or disable an event
535 * @system: system name to match (NULL for any system)
536 * @event: event name to match (NULL for all events, within system)
537 * @set: 1 to enable, 0 to disable
539 * This is a way for other parts of the kernel to enable or disable
542 * Returns 0 on success, -EINVAL if the parameters do not match any
545 int trace_set_clr_event(const char *system, const char *event, int set)
547 struct trace_array *tr = top_trace_array();
549 return __ftrace_set_clr_event(tr, NULL, system, event, set);
551 EXPORT_SYMBOL_GPL(trace_set_clr_event);
553 /* 128 should be much more than enough */
554 #define EVENT_BUF_SIZE 127
557 ftrace_event_write(struct file *file, const char __user *ubuf,
558 size_t cnt, loff_t *ppos)
560 struct trace_parser parser;
561 struct seq_file *m = file->private_data;
562 struct trace_array *tr = m->private;
568 ret = tracing_update_buffers();
572 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
575 read = trace_get_user(&parser, ubuf, cnt, ppos);
577 if (read >= 0 && trace_parser_loaded((&parser))) {
580 if (*parser.buffer == '!')
583 parser.buffer[parser.idx] = 0;
585 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
593 trace_parser_put(&parser);
599 t_next(struct seq_file *m, void *v, loff_t *pos)
601 struct ftrace_event_file *file = v;
602 struct ftrace_event_call *call;
603 struct trace_array *tr = m->private;
607 list_for_each_entry_continue(file, &tr->events, list) {
608 call = file->event_call;
610 * The ftrace subsystem is for showing formats only.
611 * They can not be enabled or disabled via the event files.
613 if (call->class && call->class->reg)
620 static void *t_start(struct seq_file *m, loff_t *pos)
622 struct ftrace_event_file *file;
623 struct trace_array *tr = m->private;
626 mutex_lock(&event_mutex);
628 file = list_entry(&tr->events, struct ftrace_event_file, list);
629 for (l = 0; l <= *pos; ) {
630 file = t_next(m, file, &l);
638 s_next(struct seq_file *m, void *v, loff_t *pos)
640 struct ftrace_event_file *file = v;
641 struct trace_array *tr = m->private;
645 list_for_each_entry_continue(file, &tr->events, list) {
646 if (file->flags & FTRACE_EVENT_FL_ENABLED)
653 static void *s_start(struct seq_file *m, loff_t *pos)
655 struct ftrace_event_file *file;
656 struct trace_array *tr = m->private;
659 mutex_lock(&event_mutex);
661 file = list_entry(&tr->events, struct ftrace_event_file, list);
662 for (l = 0; l <= *pos; ) {
663 file = s_next(m, file, &l);
670 static int t_show(struct seq_file *m, void *v)
672 struct ftrace_event_file *file = v;
673 struct ftrace_event_call *call = file->event_call;
675 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
676 seq_printf(m, "%s:", call->class->system);
677 seq_printf(m, "%s\n", call->name);
682 static void t_stop(struct seq_file *m, void *p)
684 mutex_unlock(&event_mutex);
688 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
691 struct ftrace_event_file *file;
695 mutex_lock(&event_mutex);
696 file = event_file_data(filp);
699 mutex_unlock(&event_mutex);
704 if (flags & FTRACE_EVENT_FL_ENABLED &&
705 !(flags & FTRACE_EVENT_FL_SOFT_DISABLED))
708 if (flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
709 flags & FTRACE_EVENT_FL_SOFT_MODE)
714 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
718 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
721 struct ftrace_event_file *file;
725 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
729 ret = tracing_update_buffers();
737 mutex_lock(&event_mutex);
738 file = event_file_data(filp);
740 ret = ftrace_event_enable_disable(file, val);
741 mutex_unlock(&event_mutex);
750 return ret ? ret : cnt;
754 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
757 const char set_to_char[4] = { '?', '0', '1', 'X' };
758 struct ftrace_subsystem_dir *dir = filp->private_data;
759 struct event_subsystem *system = dir->subsystem;
760 struct ftrace_event_call *call;
761 struct ftrace_event_file *file;
762 struct trace_array *tr = dir->tr;
767 mutex_lock(&event_mutex);
768 list_for_each_entry(file, &tr->events, list) {
769 call = file->event_call;
770 if (!call->name || !call->class || !call->class->reg)
773 if (system && strcmp(call->class->system, system->name) != 0)
777 * We need to find out if all the events are set
778 * or if all events or cleared, or if we have
781 set |= (1 << !!(file->flags & FTRACE_EVENT_FL_ENABLED));
784 * If we have a mixture, no need to look further.
789 mutex_unlock(&event_mutex);
791 buf[0] = set_to_char[set];
794 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
800 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
803 struct ftrace_subsystem_dir *dir = filp->private_data;
804 struct event_subsystem *system = dir->subsystem;
805 const char *name = NULL;
809 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
813 ret = tracing_update_buffers();
817 if (val != 0 && val != 1)
821 * Opening of "enable" adds a ref count to system,
822 * so the name is safe to use.
827 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
841 FORMAT_FIELD_SEPERATOR = 2,
845 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
847 struct ftrace_event_call *call = event_file_data(m->private);
848 struct list_head *common_head = &ftrace_common_fields;
849 struct list_head *head = trace_get_fields(call);
850 struct list_head *node = v;
854 switch ((unsigned long)v) {
859 case FORMAT_FIELD_SEPERATOR:
863 case FORMAT_PRINTFMT:
869 if (node == common_head)
870 return (void *)FORMAT_FIELD_SEPERATOR;
871 else if (node == head)
872 return (void *)FORMAT_PRINTFMT;
877 static int f_show(struct seq_file *m, void *v)
879 struct ftrace_event_call *call = event_file_data(m->private);
880 struct ftrace_event_field *field;
881 const char *array_descriptor;
883 switch ((unsigned long)v) {
885 seq_printf(m, "name: %s\n", call->name);
886 seq_printf(m, "ID: %d\n", call->event.type);
887 seq_printf(m, "format:\n");
890 case FORMAT_FIELD_SEPERATOR:
894 case FORMAT_PRINTFMT:
895 seq_printf(m, "\nprint fmt: %s\n",
900 field = list_entry(v, struct ftrace_event_field, link);
902 * Smartly shows the array type(except dynamic array).
905 * If TYPE := TYPE[LEN], it is shown:
906 * field:TYPE VAR[LEN]
908 array_descriptor = strchr(field->type, '[');
910 if (!strncmp(field->type, "__data_loc", 10))
911 array_descriptor = NULL;
913 if (!array_descriptor)
914 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
915 field->type, field->name, field->offset,
916 field->size, !!field->is_signed);
918 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
919 (int)(array_descriptor - field->type),
920 field->type, field->name,
921 array_descriptor, field->offset,
922 field->size, !!field->is_signed);
927 static void *f_start(struct seq_file *m, loff_t *pos)
929 void *p = (void *)FORMAT_HEADER;
932 /* ->stop() is called even if ->start() fails */
933 mutex_lock(&event_mutex);
934 if (!event_file_data(m->private))
935 return ERR_PTR(-ENODEV);
937 while (l < *pos && p)
938 p = f_next(m, p, &l);
943 static void f_stop(struct seq_file *m, void *p)
945 mutex_unlock(&event_mutex);
948 static const struct seq_operations trace_format_seq_ops = {
955 static int trace_format_open(struct inode *inode, struct file *file)
960 ret = seq_open(file, &trace_format_seq_ops);
964 m = file->private_data;
971 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
973 int id = (long)event_file_data(filp);
983 len = sprintf(buf, "%d\n", id);
985 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
989 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
992 struct ftrace_event_file *file;
999 s = kmalloc(sizeof(*s), GFP_KERNEL);
1006 mutex_lock(&event_mutex);
1007 file = event_file_data(filp);
1009 print_event_filter(file, s);
1010 mutex_unlock(&event_mutex);
1013 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1021 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1024 struct ftrace_event_file *file;
1028 if (cnt >= PAGE_SIZE)
1031 buf = (char *)__get_free_page(GFP_TEMPORARY);
1035 if (copy_from_user(buf, ubuf, cnt)) {
1036 free_page((unsigned long) buf);
1041 mutex_lock(&event_mutex);
1042 file = event_file_data(filp);
1044 err = apply_event_filter(file, buf);
1045 mutex_unlock(&event_mutex);
1047 free_page((unsigned long) buf);
1056 static LIST_HEAD(event_subsystems);
1058 static int subsystem_open(struct inode *inode, struct file *filp)
1060 struct event_subsystem *system = NULL;
1061 struct ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1062 struct trace_array *tr;
1065 /* Make sure the system still exists */
1066 mutex_lock(&trace_types_lock);
1067 mutex_lock(&event_mutex);
1068 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1069 list_for_each_entry(dir, &tr->systems, list) {
1070 if (dir == inode->i_private) {
1071 /* Don't open systems with no events */
1072 if (dir->nr_events) {
1073 __get_system_dir(dir);
1074 system = dir->subsystem;
1081 mutex_unlock(&event_mutex);
1082 mutex_unlock(&trace_types_lock);
1087 /* Some versions of gcc think dir can be uninitialized here */
1090 /* Still need to increment the ref count of the system */
1091 if (trace_array_get(tr) < 0) {
1096 ret = tracing_open_generic(inode, filp);
1098 trace_array_put(tr);
1105 static int system_tr_open(struct inode *inode, struct file *filp)
1107 struct ftrace_subsystem_dir *dir;
1108 struct trace_array *tr = inode->i_private;
1111 if (trace_array_get(tr) < 0)
1114 /* Make a temporary dir that has no system but points to tr */
1115 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1117 trace_array_put(tr);
1123 ret = tracing_open_generic(inode, filp);
1125 trace_array_put(tr);
1129 filp->private_data = dir;
1134 static int subsystem_release(struct inode *inode, struct file *file)
1136 struct ftrace_subsystem_dir *dir = file->private_data;
1138 trace_array_put(dir->tr);
1141 * If dir->subsystem is NULL, then this is a temporary
1142 * descriptor that was made for a trace_array to enable
1154 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1157 struct ftrace_subsystem_dir *dir = filp->private_data;
1158 struct event_subsystem *system = dir->subsystem;
1159 struct trace_seq *s;
1165 s = kmalloc(sizeof(*s), GFP_KERNEL);
1171 print_subsystem_event_filter(system, s);
1172 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1180 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1183 struct ftrace_subsystem_dir *dir = filp->private_data;
1187 if (cnt >= PAGE_SIZE)
1190 buf = (char *)__get_free_page(GFP_TEMPORARY);
1194 if (copy_from_user(buf, ubuf, cnt)) {
1195 free_page((unsigned long) buf);
1200 err = apply_subsystem_event_filter(dir, buf);
1201 free_page((unsigned long) buf);
1211 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1213 int (*func)(struct trace_seq *s) = filp->private_data;
1214 struct trace_seq *s;
1220 s = kmalloc(sizeof(*s), GFP_KERNEL);
1227 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1234 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1235 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1236 static int ftrace_event_release(struct inode *inode, struct file *file);
1238 static const struct seq_operations show_event_seq_ops = {
1245 static const struct seq_operations show_set_event_seq_ops = {
1252 static const struct file_operations ftrace_avail_fops = {
1253 .open = ftrace_event_avail_open,
1255 .llseek = seq_lseek,
1256 .release = seq_release,
1259 static const struct file_operations ftrace_set_event_fops = {
1260 .open = ftrace_event_set_open,
1262 .write = ftrace_event_write,
1263 .llseek = seq_lseek,
1264 .release = ftrace_event_release,
1267 static const struct file_operations ftrace_enable_fops = {
1268 .open = tracing_open_generic,
1269 .read = event_enable_read,
1270 .write = event_enable_write,
1271 .llseek = default_llseek,
1274 static const struct file_operations ftrace_event_format_fops = {
1275 .open = trace_format_open,
1277 .llseek = seq_lseek,
1278 .release = seq_release,
1281 static const struct file_operations ftrace_event_id_fops = {
1282 .read = event_id_read,
1283 .llseek = default_llseek,
1286 static const struct file_operations ftrace_event_filter_fops = {
1287 .open = tracing_open_generic,
1288 .read = event_filter_read,
1289 .write = event_filter_write,
1290 .llseek = default_llseek,
1293 static const struct file_operations ftrace_subsystem_filter_fops = {
1294 .open = subsystem_open,
1295 .read = subsystem_filter_read,
1296 .write = subsystem_filter_write,
1297 .llseek = default_llseek,
1298 .release = subsystem_release,
1301 static const struct file_operations ftrace_system_enable_fops = {
1302 .open = subsystem_open,
1303 .read = system_enable_read,
1304 .write = system_enable_write,
1305 .llseek = default_llseek,
1306 .release = subsystem_release,
1309 static const struct file_operations ftrace_tr_enable_fops = {
1310 .open = system_tr_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_show_header_fops = {
1318 .open = tracing_open_generic,
1319 .read = show_header,
1320 .llseek = default_llseek,
1324 ftrace_event_open(struct inode *inode, struct file *file,
1325 const struct seq_operations *seq_ops)
1330 ret = seq_open(file, seq_ops);
1333 m = file->private_data;
1334 /* copy tr over to seq ops */
1335 m->private = inode->i_private;
1340 static int ftrace_event_release(struct inode *inode, struct file *file)
1342 struct trace_array *tr = inode->i_private;
1344 trace_array_put(tr);
1346 return seq_release(inode, file);
1350 ftrace_event_avail_open(struct inode *inode, struct file *file)
1352 const struct seq_operations *seq_ops = &show_event_seq_ops;
1354 return ftrace_event_open(inode, file, seq_ops);
1358 ftrace_event_set_open(struct inode *inode, struct file *file)
1360 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1361 struct trace_array *tr = inode->i_private;
1364 if (trace_array_get(tr) < 0)
1367 if ((file->f_mode & FMODE_WRITE) &&
1368 (file->f_flags & O_TRUNC))
1369 ftrace_clear_events(tr);
1371 ret = ftrace_event_open(inode, file, seq_ops);
1373 trace_array_put(tr);
1377 static struct event_subsystem *
1378 create_new_subsystem(const char *name)
1380 struct event_subsystem *system;
1382 /* need to create new entry */
1383 system = kmalloc(sizeof(*system), GFP_KERNEL);
1387 system->ref_count = 1;
1389 /* Only allocate if dynamic (kprobes and modules) */
1390 if (!core_kernel_data((unsigned long)name)) {
1391 system->ref_count |= SYSTEM_FL_FREE_NAME;
1392 system->name = kstrdup(name, GFP_KERNEL);
1396 system->name = name;
1398 system->filter = NULL;
1400 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1401 if (!system->filter)
1404 list_add(&system->list, &event_subsystems);
1409 if (system->ref_count & SYSTEM_FL_FREE_NAME)
1410 kfree(system->name);
1415 static struct dentry *
1416 event_subsystem_dir(struct trace_array *tr, const char *name,
1417 struct ftrace_event_file *file, struct dentry *parent)
1419 struct ftrace_subsystem_dir *dir;
1420 struct event_subsystem *system;
1421 struct dentry *entry;
1423 /* First see if we did not already create this dir */
1424 list_for_each_entry(dir, &tr->systems, list) {
1425 system = dir->subsystem;
1426 if (strcmp(system->name, name) == 0) {
1433 /* Now see if the system itself exists. */
1434 list_for_each_entry(system, &event_subsystems, list) {
1435 if (strcmp(system->name, name) == 0)
1438 /* Reset system variable when not found */
1439 if (&system->list == &event_subsystems)
1442 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1447 system = create_new_subsystem(name);
1451 __get_system(system);
1453 dir->entry = debugfs_create_dir(name, parent);
1455 pr_warning("Failed to create system directory %s\n", name);
1456 __put_system(system);
1463 dir->subsystem = system;
1466 entry = debugfs_create_file("filter", 0644, dir->entry, dir,
1467 &ftrace_subsystem_filter_fops);
1469 kfree(system->filter);
1470 system->filter = NULL;
1471 pr_warning("Could not create debugfs '%s/filter' entry\n", name);
1474 trace_create_file("enable", 0644, dir->entry, dir,
1475 &ftrace_system_enable_fops);
1477 list_add(&dir->list, &tr->systems);
1484 /* Only print this message if failed on memory allocation */
1485 if (!dir || !system)
1486 pr_warning("No memory to create event subsystem %s\n",
1492 event_create_dir(struct dentry *parent, struct ftrace_event_file *file)
1494 struct ftrace_event_call *call = file->event_call;
1495 struct trace_array *tr = file->tr;
1496 struct list_head *head;
1497 struct dentry *d_events;
1501 * If the trace point header did not define TRACE_SYSTEM
1502 * then the system would be called "TRACE_SYSTEM".
1504 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1505 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1511 file->dir = debugfs_create_dir(call->name, d_events);
1513 pr_warning("Could not create debugfs '%s' directory\n",
1518 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1519 trace_create_file("enable", 0644, file->dir, file,
1520 &ftrace_enable_fops);
1522 #ifdef CONFIG_PERF_EVENTS
1523 if (call->event.type && call->class->reg)
1524 trace_create_file("id", 0444, file->dir,
1525 (void *)(long)call->event.type,
1526 &ftrace_event_id_fops);
1530 * Other events may have the same class. Only update
1531 * the fields if they are not already defined.
1533 head = trace_get_fields(call);
1534 if (list_empty(head)) {
1535 ret = call->class->define_fields(call);
1537 pr_warning("Could not initialize trace point"
1538 " events/%s\n", call->name);
1542 trace_create_file("filter", 0644, file->dir, file,
1543 &ftrace_event_filter_fops);
1545 trace_create_file("format", 0444, file->dir, call,
1546 &ftrace_event_format_fops);
1551 static void remove_event_from_tracers(struct ftrace_event_call *call)
1553 struct ftrace_event_file *file;
1554 struct trace_array *tr;
1556 do_for_each_event_file_safe(tr, file) {
1557 if (file->event_call != call)
1560 remove_event_file_dir(file);
1562 * The do_for_each_event_file_safe() is
1563 * a double loop. After finding the call for this
1564 * trace_array, we use break to jump to the next
1568 } while_for_each_event_file();
1571 static void event_remove(struct ftrace_event_call *call)
1573 struct trace_array *tr;
1574 struct ftrace_event_file *file;
1576 do_for_each_event_file(tr, file) {
1577 if (file->event_call != call)
1579 ftrace_event_enable_disable(file, 0);
1580 destroy_preds(file);
1582 * The do_for_each_event_file() is
1583 * a double loop. After finding the call for this
1584 * trace_array, we use break to jump to the next
1588 } while_for_each_event_file();
1590 if (call->event.funcs)
1591 __unregister_ftrace_event(&call->event);
1592 remove_event_from_tracers(call);
1593 list_del(&call->list);
1596 static int event_init(struct ftrace_event_call *call)
1600 if (WARN_ON(!call->name))
1603 if (call->class->raw_init) {
1604 ret = call->class->raw_init(call);
1605 if (ret < 0 && ret != -ENOSYS)
1606 pr_warn("Could not initialize trace events/%s\n",
1614 __register_event(struct ftrace_event_call *call, struct module *mod)
1618 ret = event_init(call);
1622 list_add(&call->list, &ftrace_events);
1628 static struct ftrace_event_file *
1629 trace_create_new_event(struct ftrace_event_call *call,
1630 struct trace_array *tr)
1632 struct ftrace_event_file *file;
1634 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
1638 file->event_call = call;
1640 atomic_set(&file->sm_ref, 0);
1641 list_add(&file->list, &tr->events);
1646 /* Add an event to a trace directory */
1648 __trace_add_new_event(struct ftrace_event_call *call, struct trace_array *tr)
1650 struct ftrace_event_file *file;
1652 file = trace_create_new_event(call, tr);
1656 return event_create_dir(tr->event_dir, file);
1660 * Just create a decriptor for early init. A descriptor is required
1661 * for enabling events at boot. We want to enable events before
1662 * the filesystem is initialized.
1665 __trace_early_add_new_event(struct ftrace_event_call *call,
1666 struct trace_array *tr)
1668 struct ftrace_event_file *file;
1670 file = trace_create_new_event(call, tr);
1677 struct ftrace_module_file_ops;
1678 static void __add_event_to_tracers(struct ftrace_event_call *call);
1680 /* Add an additional event_call dynamically */
1681 int trace_add_event_call(struct ftrace_event_call *call)
1684 mutex_lock(&trace_types_lock);
1685 mutex_lock(&event_mutex);
1687 ret = __register_event(call, NULL);
1689 __add_event_to_tracers(call);
1691 mutex_unlock(&event_mutex);
1692 mutex_unlock(&trace_types_lock);
1697 * Must be called under locking of trace_types_lock, event_mutex and
1700 static void __trace_remove_event_call(struct ftrace_event_call *call)
1703 trace_destroy_fields(call);
1704 destroy_call_preds(call);
1707 static int probe_remove_event_call(struct ftrace_event_call *call)
1709 struct trace_array *tr;
1710 struct ftrace_event_file *file;
1712 #ifdef CONFIG_PERF_EVENTS
1713 if (call->perf_refcount)
1716 do_for_each_event_file(tr, file) {
1717 if (file->event_call != call)
1720 * We can't rely on ftrace_event_enable_disable(enable => 0)
1721 * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
1722 * TRACE_REG_UNREGISTER.
1724 if (file->flags & FTRACE_EVENT_FL_ENABLED)
1727 * The do_for_each_event_file_safe() is
1728 * a double loop. After finding the call for this
1729 * trace_array, we use break to jump to the next
1733 } while_for_each_event_file();
1735 __trace_remove_event_call(call);
1740 /* Remove an event_call */
1741 int trace_remove_event_call(struct ftrace_event_call *call)
1745 mutex_lock(&trace_types_lock);
1746 mutex_lock(&event_mutex);
1747 down_write(&trace_event_sem);
1748 ret = probe_remove_event_call(call);
1749 up_write(&trace_event_sem);
1750 mutex_unlock(&event_mutex);
1751 mutex_unlock(&trace_types_lock);
1756 #define for_each_event(event, start, end) \
1757 for (event = start; \
1758 (unsigned long)event < (unsigned long)end; \
1761 #ifdef CONFIG_MODULES
1763 static void trace_module_add_events(struct module *mod)
1765 struct ftrace_event_call **call, **start, **end;
1767 start = mod->trace_events;
1768 end = mod->trace_events + mod->num_trace_events;
1770 for_each_event(call, start, end) {
1771 __register_event(*call, mod);
1772 __add_event_to_tracers(*call);
1776 static void trace_module_remove_events(struct module *mod)
1778 struct ftrace_event_call *call, *p;
1779 bool clear_trace = false;
1781 down_write(&trace_event_sem);
1782 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1783 if (call->mod == mod) {
1784 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
1786 __trace_remove_event_call(call);
1789 up_write(&trace_event_sem);
1792 * It is safest to reset the ring buffer if the module being unloaded
1793 * registered any events that were used. The only worry is if
1794 * a new module gets loaded, and takes on the same id as the events
1795 * of this module. When printing out the buffer, traced events left
1796 * over from this module may be passed to the new module events and
1797 * unexpected results may occur.
1800 tracing_reset_all_online_cpus();
1803 static int trace_module_notify(struct notifier_block *self,
1804 unsigned long val, void *data)
1806 struct module *mod = data;
1808 mutex_lock(&trace_types_lock);
1809 mutex_lock(&event_mutex);
1811 case MODULE_STATE_COMING:
1812 trace_module_add_events(mod);
1814 case MODULE_STATE_GOING:
1815 trace_module_remove_events(mod);
1818 mutex_unlock(&event_mutex);
1819 mutex_unlock(&trace_types_lock);
1824 static struct notifier_block trace_module_nb = {
1825 .notifier_call = trace_module_notify,
1828 #endif /* CONFIG_MODULES */
1830 /* Create a new event directory structure for a trace directory. */
1832 __trace_add_event_dirs(struct trace_array *tr)
1834 struct ftrace_event_call *call;
1837 list_for_each_entry(call, &ftrace_events, list) {
1838 ret = __trace_add_new_event(call, tr);
1840 pr_warning("Could not create directory for event %s\n",
1845 #ifdef CONFIG_DYNAMIC_FTRACE
1848 #define ENABLE_EVENT_STR "enable_event"
1849 #define DISABLE_EVENT_STR "disable_event"
1851 struct event_probe_data {
1852 struct ftrace_event_file *file;
1853 unsigned long count;
1858 static struct ftrace_event_file *
1859 find_event_file(struct trace_array *tr, const char *system, const char *event)
1861 struct ftrace_event_file *file;
1862 struct ftrace_event_call *call;
1864 list_for_each_entry(file, &tr->events, list) {
1866 call = file->event_call;
1868 if (!call->name || !call->class || !call->class->reg)
1871 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1874 if (strcmp(event, call->name) == 0 &&
1875 strcmp(system, call->class->system) == 0)
1882 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1884 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1885 struct event_probe_data *data = *pdata;
1891 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1893 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1897 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1899 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1900 struct event_probe_data *data = *pdata;
1908 /* Skip if the event is in a state we want to switch to */
1909 if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
1912 if (data->count != -1)
1915 event_enable_probe(ip, parent_ip, _data);
1919 event_enable_print(struct seq_file *m, unsigned long ip,
1920 struct ftrace_probe_ops *ops, void *_data)
1922 struct event_probe_data *data = _data;
1924 seq_printf(m, "%ps:", (void *)ip);
1926 seq_printf(m, "%s:%s:%s",
1927 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
1928 data->file->event_call->class->system,
1929 data->file->event_call->name);
1931 if (data->count == -1)
1932 seq_printf(m, ":unlimited\n");
1934 seq_printf(m, ":count=%ld\n", data->count);
1940 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
1943 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1944 struct event_probe_data *data = *pdata;
1951 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
1954 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1955 struct event_probe_data *data = *pdata;
1957 if (WARN_ON_ONCE(data->ref <= 0))
1962 /* Remove the SOFT_MODE flag */
1963 __ftrace_event_enable_disable(data->file, 0, 1);
1964 module_put(data->file->event_call->mod);
1970 static struct ftrace_probe_ops event_enable_probe_ops = {
1971 .func = event_enable_probe,
1972 .print = event_enable_print,
1973 .init = event_enable_init,
1974 .free = event_enable_free,
1977 static struct ftrace_probe_ops event_enable_count_probe_ops = {
1978 .func = event_enable_count_probe,
1979 .print = event_enable_print,
1980 .init = event_enable_init,
1981 .free = event_enable_free,
1984 static struct ftrace_probe_ops event_disable_probe_ops = {
1985 .func = event_enable_probe,
1986 .print = event_enable_print,
1987 .init = event_enable_init,
1988 .free = event_enable_free,
1991 static struct ftrace_probe_ops event_disable_count_probe_ops = {
1992 .func = event_enable_count_probe,
1993 .print = event_enable_print,
1994 .init = event_enable_init,
1995 .free = event_enable_free,
1999 event_enable_func(struct ftrace_hash *hash,
2000 char *glob, char *cmd, char *param, int enabled)
2002 struct trace_array *tr = top_trace_array();
2003 struct ftrace_event_file *file;
2004 struct ftrace_probe_ops *ops;
2005 struct event_probe_data *data;
2012 /* hash funcs only work with set_ftrace_filter */
2013 if (!enabled || !param)
2016 system = strsep(¶m, ":");
2020 event = strsep(¶m, ":");
2022 mutex_lock(&event_mutex);
2025 file = find_event_file(tr, system, event);
2029 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2032 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2034 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2036 if (glob[0] == '!') {
2037 unregister_ftrace_function_probe_func(glob+1, ops);
2043 data = kzalloc(sizeof(*data), GFP_KERNEL);
2047 data->enable = enable;
2054 number = strsep(¶m, ":");
2057 if (!strlen(number))
2061 * We use the callback data field (which is a pointer)
2064 ret = kstrtoul(number, 0, &data->count);
2069 /* Don't let event modules unload while probe registered */
2070 ret = try_module_get(file->event_call->mod);
2076 ret = __ftrace_event_enable_disable(file, 1, 1);
2079 ret = register_ftrace_function_probe(glob, ops, data);
2081 * The above returns on success the # of functions enabled,
2082 * but if it didn't find any functions it returns zero.
2083 * Consider no functions a failure too.
2090 /* Just return zero, not the number of enabled functions */
2093 mutex_unlock(&event_mutex);
2097 __ftrace_event_enable_disable(file, 0, 1);
2099 module_put(file->event_call->mod);
2105 static struct ftrace_func_command event_enable_cmd = {
2106 .name = ENABLE_EVENT_STR,
2107 .func = event_enable_func,
2110 static struct ftrace_func_command event_disable_cmd = {
2111 .name = DISABLE_EVENT_STR,
2112 .func = event_enable_func,
2115 static __init int register_event_cmds(void)
2119 ret = register_ftrace_command(&event_enable_cmd);
2120 if (WARN_ON(ret < 0))
2122 ret = register_ftrace_command(&event_disable_cmd);
2123 if (WARN_ON(ret < 0))
2124 unregister_ftrace_command(&event_enable_cmd);
2128 static inline int register_event_cmds(void) { return 0; }
2129 #endif /* CONFIG_DYNAMIC_FTRACE */
2132 * The top level array has already had its ftrace_event_file
2133 * descriptors created in order to allow for early events to
2134 * be recorded. This function is called after the debugfs has been
2135 * initialized, and we now have to create the files associated
2139 __trace_early_add_event_dirs(struct trace_array *tr)
2141 struct ftrace_event_file *file;
2145 list_for_each_entry(file, &tr->events, list) {
2146 ret = event_create_dir(tr->event_dir, file);
2148 pr_warning("Could not create directory for event %s\n",
2149 file->event_call->name);
2154 * For early boot up, the top trace array requires to have
2155 * a list of events that can be enabled. This must be done before
2156 * the filesystem is set up in order to allow events to be traced
2160 __trace_early_add_events(struct trace_array *tr)
2162 struct ftrace_event_call *call;
2165 list_for_each_entry(call, &ftrace_events, list) {
2166 /* Early boot up should not have any modules loaded */
2167 if (WARN_ON_ONCE(call->mod))
2170 ret = __trace_early_add_new_event(call, tr);
2172 pr_warning("Could not create early event %s\n",
2177 /* Remove the event directory structure for a trace directory. */
2179 __trace_remove_event_dirs(struct trace_array *tr)
2181 struct ftrace_event_file *file, *next;
2183 list_for_each_entry_safe(file, next, &tr->events, list)
2184 remove_event_file_dir(file);
2187 static void __add_event_to_tracers(struct ftrace_event_call *call)
2189 struct trace_array *tr;
2191 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2192 __trace_add_new_event(call, tr);
2195 extern struct ftrace_event_call *__start_ftrace_events[];
2196 extern struct ftrace_event_call *__stop_ftrace_events[];
2198 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2200 static __init int setup_trace_event(char *str)
2202 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2203 ring_buffer_expanded = true;
2204 tracing_selftest_disabled = true;
2208 __setup("trace_event=", setup_trace_event);
2210 /* Expects to have event_mutex held when called */
2212 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2214 struct dentry *d_events;
2215 struct dentry *entry;
2217 entry = debugfs_create_file("set_event", 0644, parent,
2218 tr, &ftrace_set_event_fops);
2220 pr_warning("Could not create debugfs 'set_event' entry\n");
2224 d_events = debugfs_create_dir("events", parent);
2226 pr_warning("Could not create debugfs 'events' directory\n");
2230 /* ring buffer internal formats */
2231 trace_create_file("header_page", 0444, d_events,
2232 ring_buffer_print_page_header,
2233 &ftrace_show_header_fops);
2235 trace_create_file("header_event", 0444, d_events,
2236 ring_buffer_print_entry_header,
2237 &ftrace_show_header_fops);
2239 trace_create_file("enable", 0644, d_events,
2240 tr, &ftrace_tr_enable_fops);
2242 tr->event_dir = d_events;
2248 * event_trace_add_tracer - add a instance of a trace_array to events
2249 * @parent: The parent dentry to place the files/directories for events in
2250 * @tr: The trace array associated with these events
2252 * When a new instance is created, it needs to set up its events
2253 * directory, as well as other files associated with events. It also
2254 * creates the event hierachry in the @parent/events directory.
2256 * Returns 0 on success.
2258 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2262 mutex_lock(&event_mutex);
2264 ret = create_event_toplevel_files(parent, tr);
2268 down_write(&trace_event_sem);
2269 __trace_add_event_dirs(tr);
2270 up_write(&trace_event_sem);
2273 mutex_unlock(&event_mutex);
2279 * The top trace array already had its file descriptors created.
2280 * Now the files themselves need to be created.
2283 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2287 mutex_lock(&event_mutex);
2289 ret = create_event_toplevel_files(parent, tr);
2293 down_write(&trace_event_sem);
2294 __trace_early_add_event_dirs(tr);
2295 up_write(&trace_event_sem);
2298 mutex_unlock(&event_mutex);
2303 int event_trace_del_tracer(struct trace_array *tr)
2305 mutex_lock(&event_mutex);
2307 /* Disable any running events */
2308 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
2310 down_write(&trace_event_sem);
2311 __trace_remove_event_dirs(tr);
2312 debugfs_remove_recursive(tr->event_dir);
2313 up_write(&trace_event_sem);
2315 tr->event_dir = NULL;
2317 mutex_unlock(&event_mutex);
2322 static __init int event_trace_memsetup(void)
2324 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
2325 file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC);
2329 static __init int event_trace_enable(void)
2331 struct trace_array *tr = top_trace_array();
2332 struct ftrace_event_call **iter, *call;
2333 char *buf = bootup_event_buf;
2337 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
2340 ret = event_init(call);
2342 list_add(&call->list, &ftrace_events);
2346 * We need the top trace array to have a working set of trace
2347 * points at early init, before the debug files and directories
2348 * are created. Create the file entries now, and attach them
2349 * to the actual file dentries later.
2351 __trace_early_add_events(tr);
2354 token = strsep(&buf, ",");
2361 ret = ftrace_set_clr_event(tr, token, 1);
2363 pr_warn("Failed to enable trace event: %s\n", token);
2366 trace_printk_start_comm();
2368 register_event_cmds();
2373 static __init int event_trace_init(void)
2375 struct trace_array *tr;
2376 struct dentry *d_tracer;
2377 struct dentry *entry;
2380 tr = top_trace_array();
2382 d_tracer = tracing_init_dentry();
2386 entry = debugfs_create_file("available_events", 0444, d_tracer,
2387 tr, &ftrace_avail_fops);
2389 pr_warning("Could not create debugfs "
2390 "'available_events' entry\n");
2392 if (trace_define_common_fields())
2393 pr_warning("tracing: Failed to allocate common fields");
2395 ret = early_event_add_tracer(d_tracer, tr);
2399 #ifdef CONFIG_MODULES
2400 ret = register_module_notifier(&trace_module_nb);
2402 pr_warning("Failed to register trace events module notifier\n");
2406 early_initcall(event_trace_memsetup);
2407 core_initcall(event_trace_enable);
2408 fs_initcall(event_trace_init);
2410 #ifdef CONFIG_FTRACE_STARTUP_TEST
2412 static DEFINE_SPINLOCK(test_spinlock);
2413 static DEFINE_SPINLOCK(test_spinlock_irq);
2414 static DEFINE_MUTEX(test_mutex);
2416 static __init void test_work(struct work_struct *dummy)
2418 spin_lock(&test_spinlock);
2419 spin_lock_irq(&test_spinlock_irq);
2421 spin_unlock_irq(&test_spinlock_irq);
2422 spin_unlock(&test_spinlock);
2424 mutex_lock(&test_mutex);
2426 mutex_unlock(&test_mutex);
2429 static __init int event_test_thread(void *unused)
2433 test_malloc = kmalloc(1234, GFP_KERNEL);
2435 pr_info("failed to kmalloc\n");
2437 schedule_on_each_cpu(test_work);
2441 set_current_state(TASK_INTERRUPTIBLE);
2442 while (!kthread_should_stop())
2449 * Do various things that may trigger events.
2451 static __init void event_test_stuff(void)
2453 struct task_struct *test_thread;
2455 test_thread = kthread_run(event_test_thread, NULL, "test-events");
2457 kthread_stop(test_thread);
2461 * For every trace event defined, we will test each trace point separately,
2462 * and then by groups, and finally all trace points.
2464 static __init void event_trace_self_tests(void)
2466 struct ftrace_subsystem_dir *dir;
2467 struct ftrace_event_file *file;
2468 struct ftrace_event_call *call;
2469 struct event_subsystem *system;
2470 struct trace_array *tr;
2473 tr = top_trace_array();
2475 pr_info("Running tests on trace events:\n");
2477 list_for_each_entry(file, &tr->events, list) {
2479 call = file->event_call;
2481 /* Only test those that have a probe */
2482 if (!call->class || !call->class->probe)
2486 * Testing syscall events here is pretty useless, but
2487 * we still do it if configured. But this is time consuming.
2488 * What we really need is a user thread to perform the
2489 * syscalls as we test.
2491 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
2492 if (call->class->system &&
2493 strcmp(call->class->system, "syscalls") == 0)
2497 pr_info("Testing event %s: ", call->name);
2500 * If an event is already enabled, someone is using
2501 * it and the self test should not be on.
2503 if (file->flags & FTRACE_EVENT_FL_ENABLED) {
2504 pr_warning("Enabled event during self test!\n");
2509 ftrace_event_enable_disable(file, 1);
2511 ftrace_event_enable_disable(file, 0);
2516 /* Now test at the sub system level */
2518 pr_info("Running tests on trace event systems:\n");
2520 list_for_each_entry(dir, &tr->systems, list) {
2522 system = dir->subsystem;
2524 /* the ftrace system is special, skip it */
2525 if (strcmp(system->name, "ftrace") == 0)
2528 pr_info("Testing event system %s: ", system->name);
2530 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
2531 if (WARN_ON_ONCE(ret)) {
2532 pr_warning("error enabling system %s\n",
2539 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
2540 if (WARN_ON_ONCE(ret)) {
2541 pr_warning("error disabling system %s\n",
2549 /* Test with all events enabled */
2551 pr_info("Running tests on all trace events:\n");
2552 pr_info("Testing all events: ");
2554 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
2555 if (WARN_ON_ONCE(ret)) {
2556 pr_warning("error enabling all events\n");
2563 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
2564 if (WARN_ON_ONCE(ret)) {
2565 pr_warning("error disabling all events\n");
2572 #ifdef CONFIG_FUNCTION_TRACER
2574 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
2577 function_test_events_call(unsigned long ip, unsigned long parent_ip,
2578 struct ftrace_ops *op, struct pt_regs *pt_regs)
2580 struct ring_buffer_event *event;
2581 struct ring_buffer *buffer;
2582 struct ftrace_entry *entry;
2583 unsigned long flags;
2588 pc = preempt_count();
2589 preempt_disable_notrace();
2590 cpu = raw_smp_processor_id();
2591 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
2596 local_save_flags(flags);
2598 event = trace_current_buffer_lock_reserve(&buffer,
2599 TRACE_FN, sizeof(*entry),
2603 entry = ring_buffer_event_data(event);
2605 entry->parent_ip = parent_ip;
2607 trace_buffer_unlock_commit(buffer, event, flags, pc);
2610 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
2611 preempt_enable_notrace();
2614 static struct ftrace_ops trace_ops __initdata =
2616 .func = function_test_events_call,
2617 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
2620 static __init void event_trace_self_test_with_function(void)
2623 ret = register_ftrace_function(&trace_ops);
2624 if (WARN_ON(ret < 0)) {
2625 pr_info("Failed to enable function tracer for event tests\n");
2628 pr_info("Running tests again, along with the function tracer\n");
2629 event_trace_self_tests();
2630 unregister_ftrace_function(&trace_ops);
2633 static __init void event_trace_self_test_with_function(void)
2638 static __init int event_trace_self_tests_init(void)
2640 if (!tracing_selftest_disabled) {
2641 event_trace_self_tests();
2642 event_trace_self_test_with_function();
2648 late_initcall(event_trace_self_tests_init);