4 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
6 * - Added format output of fields of the trace point.
7 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
11 #include <linux/workqueue.h>
12 #include <linux/spinlock.h>
13 #include <linux/kthread.h>
14 #include <linux/debugfs.h>
15 #include <linux/uaccess.h>
16 #include <linux/module.h>
17 #include <linux/ctype.h>
18 #include <linux/slab.h>
19 #include <linux/delay.h>
21 #include <asm/setup.h>
23 #include "trace_output.h"
26 #define TRACE_SYSTEM "TRACE_SYSTEM"
28 DEFINE_MUTEX(event_mutex);
30 LIST_HEAD(ftrace_events);
31 static LIST_HEAD(ftrace_common_fields);
33 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
35 static struct kmem_cache *field_cachep;
36 static struct kmem_cache *file_cachep;
38 #define SYSTEM_FL_FREE_NAME (1 << 31)
40 static inline int system_refcount(struct event_subsystem *system)
42 return system->ref_count & ~SYSTEM_FL_FREE_NAME;
45 static int system_refcount_inc(struct event_subsystem *system)
47 return (system->ref_count++) & ~SYSTEM_FL_FREE_NAME;
50 static int system_refcount_dec(struct event_subsystem *system)
52 return (--system->ref_count) & ~SYSTEM_FL_FREE_NAME;
55 /* Double loops, do not use break, only goto's work */
56 #define do_for_each_event_file(tr, file) \
57 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
58 list_for_each_entry(file, &tr->events, list)
60 #define do_for_each_event_file_safe(tr, file) \
61 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
62 struct ftrace_event_file *___n; \
63 list_for_each_entry_safe(file, ___n, &tr->events, list)
65 #define while_for_each_event_file() \
68 static struct list_head *
69 trace_get_fields(struct ftrace_event_call *event_call)
71 if (!event_call->class->get_fields)
72 return &event_call->class->fields;
73 return event_call->class->get_fields(event_call);
76 static struct ftrace_event_field *
77 __find_event_field(struct list_head *head, char *name)
79 struct ftrace_event_field *field;
81 list_for_each_entry(field, head, link) {
82 if (!strcmp(field->name, name))
89 struct ftrace_event_field *
90 trace_find_event_field(struct ftrace_event_call *call, char *name)
92 struct ftrace_event_field *field;
93 struct list_head *head;
95 field = __find_event_field(&ftrace_common_fields, name);
99 head = trace_get_fields(call);
100 return __find_event_field(head, name);
103 static int __trace_define_field(struct list_head *head, const char *type,
104 const char *name, int offset, int size,
105 int is_signed, int filter_type)
107 struct ftrace_event_field *field;
109 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
116 if (filter_type == FILTER_OTHER)
117 field->filter_type = filter_assign_type(type);
119 field->filter_type = filter_type;
121 field->offset = offset;
123 field->is_signed = is_signed;
125 list_add(&field->link, head);
130 int trace_define_field(struct ftrace_event_call *call, const char *type,
131 const char *name, int offset, int size, int is_signed,
134 struct list_head *head;
136 if (WARN_ON(!call->class))
139 head = trace_get_fields(call);
140 return __trace_define_field(head, type, name, offset, size,
141 is_signed, filter_type);
143 EXPORT_SYMBOL_GPL(trace_define_field);
145 #define __common_field(type, item) \
146 ret = __trace_define_field(&ftrace_common_fields, #type, \
148 offsetof(typeof(ent), item), \
150 is_signed_type(type), FILTER_OTHER); \
154 static int trace_define_common_fields(void)
157 struct trace_entry ent;
159 __common_field(unsigned short, type);
160 __common_field(unsigned char, flags);
161 __common_field(unsigned char, preempt_count);
162 __common_field(int, pid);
167 static void trace_destroy_fields(struct ftrace_event_call *call)
169 struct ftrace_event_field *field, *next;
170 struct list_head *head;
172 head = trace_get_fields(call);
173 list_for_each_entry_safe(field, next, head, link) {
174 list_del(&field->link);
175 kmem_cache_free(field_cachep, field);
179 int trace_event_raw_init(struct ftrace_event_call *call)
183 id = register_ftrace_event(&call->event);
189 EXPORT_SYMBOL_GPL(trace_event_raw_init);
191 void *ftrace_event_buffer_reserve(struct ftrace_event_buffer *fbuffer,
192 struct ftrace_event_file *ftrace_file,
195 struct ftrace_event_call *event_call = ftrace_file->event_call;
197 local_save_flags(fbuffer->flags);
198 fbuffer->pc = preempt_count();
199 fbuffer->ftrace_file = ftrace_file;
202 trace_event_buffer_lock_reserve(&fbuffer->buffer, ftrace_file,
203 event_call->event.type, len,
204 fbuffer->flags, fbuffer->pc);
208 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
209 return fbuffer->entry;
211 EXPORT_SYMBOL_GPL(ftrace_event_buffer_reserve);
213 void ftrace_event_buffer_commit(struct ftrace_event_buffer *fbuffer)
215 event_trigger_unlock_commit(fbuffer->ftrace_file, fbuffer->buffer,
216 fbuffer->event, fbuffer->entry,
217 fbuffer->flags, fbuffer->pc);
219 EXPORT_SYMBOL_GPL(ftrace_event_buffer_commit);
221 int ftrace_event_reg(struct ftrace_event_call *call,
222 enum trace_reg type, void *data)
224 struct ftrace_event_file *file = data;
226 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
228 case TRACE_REG_REGISTER:
229 return tracepoint_probe_register(call->tp,
232 case TRACE_REG_UNREGISTER:
233 tracepoint_probe_unregister(call->tp,
238 #ifdef CONFIG_PERF_EVENTS
239 case TRACE_REG_PERF_REGISTER:
240 return tracepoint_probe_register(call->tp,
241 call->class->perf_probe,
243 case TRACE_REG_PERF_UNREGISTER:
244 tracepoint_probe_unregister(call->tp,
245 call->class->perf_probe,
248 case TRACE_REG_PERF_OPEN:
249 case TRACE_REG_PERF_CLOSE:
250 case TRACE_REG_PERF_ADD:
251 case TRACE_REG_PERF_DEL:
257 EXPORT_SYMBOL_GPL(ftrace_event_reg);
259 void trace_event_enable_cmd_record(bool enable)
261 struct ftrace_event_file *file;
262 struct trace_array *tr;
264 mutex_lock(&event_mutex);
265 do_for_each_event_file(tr, file) {
267 if (!(file->flags & FTRACE_EVENT_FL_ENABLED))
271 tracing_start_cmdline_record();
272 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
274 tracing_stop_cmdline_record();
275 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
277 } while_for_each_event_file();
278 mutex_unlock(&event_mutex);
281 static int __ftrace_event_enable_disable(struct ftrace_event_file *file,
282 int enable, int soft_disable)
284 struct ftrace_event_call *call = file->event_call;
291 * When soft_disable is set and enable is cleared, the sm_ref
292 * reference counter is decremented. If it reaches 0, we want
293 * to clear the SOFT_DISABLED flag but leave the event in the
294 * state that it was. That is, if the event was enabled and
295 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
296 * is set we do not want the event to be enabled before we
299 * When soft_disable is not set but the SOFT_MODE flag is,
300 * we do nothing. Do not disable the tracepoint, otherwise
301 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
304 if (atomic_dec_return(&file->sm_ref) > 0)
306 disable = file->flags & FTRACE_EVENT_FL_SOFT_DISABLED;
307 clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
309 disable = !(file->flags & FTRACE_EVENT_FL_SOFT_MODE);
311 if (disable && (file->flags & FTRACE_EVENT_FL_ENABLED)) {
312 clear_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
313 if (file->flags & FTRACE_EVENT_FL_RECORDED_CMD) {
314 tracing_stop_cmdline_record();
315 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
317 call->class->reg(call, TRACE_REG_UNREGISTER, file);
319 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
320 if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
321 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
323 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
327 * When soft_disable is set and enable is set, we want to
328 * register the tracepoint for the event, but leave the event
329 * as is. That means, if the event was already enabled, we do
330 * nothing (but set SOFT_MODE). If the event is disabled, we
331 * set SOFT_DISABLED before enabling the event tracepoint, so
332 * it still seems to be disabled.
335 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
337 if (atomic_inc_return(&file->sm_ref) > 1)
339 set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
342 if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) {
344 /* Keep the event disabled, when going to SOFT_MODE. */
346 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
348 if (trace_flags & TRACE_ITER_RECORD_CMD) {
349 tracing_start_cmdline_record();
350 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
352 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
354 tracing_stop_cmdline_record();
355 pr_info("event trace: Could not enable event "
356 "%s\n", ftrace_event_name(call));
359 set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
361 /* WAS_ENABLED gets set but never cleared. */
362 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
370 int trace_event_enable_disable(struct ftrace_event_file *file,
371 int enable, int soft_disable)
373 return __ftrace_event_enable_disable(file, enable, soft_disable);
376 static int ftrace_event_enable_disable(struct ftrace_event_file *file,
379 return __ftrace_event_enable_disable(file, enable, 0);
382 static void ftrace_clear_events(struct trace_array *tr)
384 struct ftrace_event_file *file;
386 mutex_lock(&event_mutex);
387 list_for_each_entry(file, &tr->events, list) {
388 ftrace_event_enable_disable(file, 0);
390 mutex_unlock(&event_mutex);
393 static void __put_system(struct event_subsystem *system)
395 struct event_filter *filter = system->filter;
397 WARN_ON_ONCE(system_refcount(system) == 0);
398 if (system_refcount_dec(system))
401 list_del(&system->list);
404 kfree(filter->filter_string);
407 if (system->ref_count & SYSTEM_FL_FREE_NAME)
412 static void __get_system(struct event_subsystem *system)
414 WARN_ON_ONCE(system_refcount(system) == 0);
415 system_refcount_inc(system);
418 static void __get_system_dir(struct ftrace_subsystem_dir *dir)
420 WARN_ON_ONCE(dir->ref_count == 0);
422 __get_system(dir->subsystem);
425 static void __put_system_dir(struct ftrace_subsystem_dir *dir)
427 WARN_ON_ONCE(dir->ref_count == 0);
428 /* If the subsystem is about to be freed, the dir must be too */
429 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
431 __put_system(dir->subsystem);
432 if (!--dir->ref_count)
436 static void put_system(struct ftrace_subsystem_dir *dir)
438 mutex_lock(&event_mutex);
439 __put_system_dir(dir);
440 mutex_unlock(&event_mutex);
443 static void remove_subsystem(struct ftrace_subsystem_dir *dir)
448 if (!--dir->nr_events) {
449 debugfs_remove_recursive(dir->entry);
450 list_del(&dir->list);
451 __put_system_dir(dir);
455 static void remove_event_file_dir(struct ftrace_event_file *file)
457 struct dentry *dir = file->dir;
458 struct dentry *child;
461 spin_lock(&dir->d_lock); /* probably unneeded */
462 list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
463 if (child->d_inode) /* probably unneeded */
464 child->d_inode->i_private = NULL;
466 spin_unlock(&dir->d_lock);
468 debugfs_remove_recursive(dir);
471 list_del(&file->list);
472 remove_subsystem(file->system);
473 kmem_cache_free(file_cachep, file);
477 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
480 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
481 const char *sub, const char *event, int set)
483 struct ftrace_event_file *file;
484 struct ftrace_event_call *call;
488 list_for_each_entry(file, &tr->events, list) {
490 call = file->event_call;
491 name = ftrace_event_name(call);
493 if (!name || !call->class || !call->class->reg)
496 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
500 strcmp(match, name) != 0 &&
501 strcmp(match, call->class->system) != 0)
504 if (sub && strcmp(sub, call->class->system) != 0)
507 if (event && strcmp(event, name) != 0)
510 ftrace_event_enable_disable(file, set);
518 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
519 const char *sub, const char *event, int set)
523 mutex_lock(&event_mutex);
524 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
525 mutex_unlock(&event_mutex);
530 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
532 char *event = NULL, *sub = NULL, *match;
535 * The buf format can be <subsystem>:<event-name>
536 * *:<event-name> means any event by that name.
537 * :<event-name> is the same.
539 * <subsystem>:* means all events in that subsystem
540 * <subsystem>: means the same.
542 * <name> (no ':') means all events in a subsystem with
543 * the name <name> or any event that matches <name>
546 match = strsep(&buf, ":");
552 if (!strlen(sub) || strcmp(sub, "*") == 0)
554 if (!strlen(event) || strcmp(event, "*") == 0)
558 return __ftrace_set_clr_event(tr, match, sub, event, set);
562 * trace_set_clr_event - enable or disable an event
563 * @system: system name to match (NULL for any system)
564 * @event: event name to match (NULL for all events, within system)
565 * @set: 1 to enable, 0 to disable
567 * This is a way for other parts of the kernel to enable or disable
570 * Returns 0 on success, -EINVAL if the parameters do not match any
573 int trace_set_clr_event(const char *system, const char *event, int set)
575 struct trace_array *tr = top_trace_array();
580 return __ftrace_set_clr_event(tr, NULL, system, event, set);
582 EXPORT_SYMBOL_GPL(trace_set_clr_event);
584 /* 128 should be much more than enough */
585 #define EVENT_BUF_SIZE 127
588 ftrace_event_write(struct file *file, const char __user *ubuf,
589 size_t cnt, loff_t *ppos)
591 struct trace_parser parser;
592 struct seq_file *m = file->private_data;
593 struct trace_array *tr = m->private;
599 ret = tracing_update_buffers();
603 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
606 read = trace_get_user(&parser, ubuf, cnt, ppos);
608 if (read >= 0 && trace_parser_loaded((&parser))) {
611 if (*parser.buffer == '!')
614 parser.buffer[parser.idx] = 0;
616 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
624 trace_parser_put(&parser);
630 t_next(struct seq_file *m, void *v, loff_t *pos)
632 struct ftrace_event_file *file = v;
633 struct ftrace_event_call *call;
634 struct trace_array *tr = m->private;
638 list_for_each_entry_continue(file, &tr->events, list) {
639 call = file->event_call;
641 * The ftrace subsystem is for showing formats only.
642 * They can not be enabled or disabled via the event files.
644 if (call->class && call->class->reg)
651 static void *t_start(struct seq_file *m, loff_t *pos)
653 struct ftrace_event_file *file;
654 struct trace_array *tr = m->private;
657 mutex_lock(&event_mutex);
659 file = list_entry(&tr->events, struct ftrace_event_file, list);
660 for (l = 0; l <= *pos; ) {
661 file = t_next(m, file, &l);
669 s_next(struct seq_file *m, void *v, loff_t *pos)
671 struct ftrace_event_file *file = v;
672 struct trace_array *tr = m->private;
676 list_for_each_entry_continue(file, &tr->events, list) {
677 if (file->flags & FTRACE_EVENT_FL_ENABLED)
684 static void *s_start(struct seq_file *m, loff_t *pos)
686 struct ftrace_event_file *file;
687 struct trace_array *tr = m->private;
690 mutex_lock(&event_mutex);
692 file = list_entry(&tr->events, struct ftrace_event_file, list);
693 for (l = 0; l <= *pos; ) {
694 file = s_next(m, file, &l);
701 static int t_show(struct seq_file *m, void *v)
703 struct ftrace_event_file *file = v;
704 struct ftrace_event_call *call = file->event_call;
706 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
707 seq_printf(m, "%s:", call->class->system);
708 seq_printf(m, "%s\n", ftrace_event_name(call));
713 static void t_stop(struct seq_file *m, void *p)
715 mutex_unlock(&event_mutex);
719 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
722 struct ftrace_event_file *file;
726 mutex_lock(&event_mutex);
727 file = event_file_data(filp);
730 mutex_unlock(&event_mutex);
735 if (flags & FTRACE_EVENT_FL_ENABLED &&
736 !(flags & FTRACE_EVENT_FL_SOFT_DISABLED))
739 if (flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
740 flags & FTRACE_EVENT_FL_SOFT_MODE)
745 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
749 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
752 struct ftrace_event_file *file;
756 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
760 ret = tracing_update_buffers();
768 mutex_lock(&event_mutex);
769 file = event_file_data(filp);
771 ret = ftrace_event_enable_disable(file, val);
772 mutex_unlock(&event_mutex);
781 return ret ? ret : cnt;
785 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
788 const char set_to_char[4] = { '?', '0', '1', 'X' };
789 struct ftrace_subsystem_dir *dir = filp->private_data;
790 struct event_subsystem *system = dir->subsystem;
791 struct ftrace_event_call *call;
792 struct ftrace_event_file *file;
793 struct trace_array *tr = dir->tr;
798 mutex_lock(&event_mutex);
799 list_for_each_entry(file, &tr->events, list) {
800 call = file->event_call;
801 if (!ftrace_event_name(call) || !call->class || !call->class->reg)
804 if (system && strcmp(call->class->system, system->name) != 0)
808 * We need to find out if all the events are set
809 * or if all events or cleared, or if we have
812 set |= (1 << !!(file->flags & FTRACE_EVENT_FL_ENABLED));
815 * If we have a mixture, no need to look further.
820 mutex_unlock(&event_mutex);
822 buf[0] = set_to_char[set];
825 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
831 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
834 struct ftrace_subsystem_dir *dir = filp->private_data;
835 struct event_subsystem *system = dir->subsystem;
836 const char *name = NULL;
840 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
844 ret = tracing_update_buffers();
848 if (val != 0 && val != 1)
852 * Opening of "enable" adds a ref count to system,
853 * so the name is safe to use.
858 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
872 FORMAT_FIELD_SEPERATOR = 2,
876 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
878 struct ftrace_event_call *call = event_file_data(m->private);
879 struct list_head *common_head = &ftrace_common_fields;
880 struct list_head *head = trace_get_fields(call);
881 struct list_head *node = v;
885 switch ((unsigned long)v) {
890 case FORMAT_FIELD_SEPERATOR:
894 case FORMAT_PRINTFMT:
900 if (node == common_head)
901 return (void *)FORMAT_FIELD_SEPERATOR;
902 else if (node == head)
903 return (void *)FORMAT_PRINTFMT;
908 static int f_show(struct seq_file *m, void *v)
910 struct ftrace_event_call *call = event_file_data(m->private);
911 struct ftrace_event_field *field;
912 const char *array_descriptor;
914 switch ((unsigned long)v) {
916 seq_printf(m, "name: %s\n", ftrace_event_name(call));
917 seq_printf(m, "ID: %d\n", call->event.type);
918 seq_printf(m, "format:\n");
921 case FORMAT_FIELD_SEPERATOR:
925 case FORMAT_PRINTFMT:
926 seq_printf(m, "\nprint fmt: %s\n",
931 field = list_entry(v, struct ftrace_event_field, link);
933 * Smartly shows the array type(except dynamic array).
936 * If TYPE := TYPE[LEN], it is shown:
937 * field:TYPE VAR[LEN]
939 array_descriptor = strchr(field->type, '[');
941 if (!strncmp(field->type, "__data_loc", 10))
942 array_descriptor = NULL;
944 if (!array_descriptor)
945 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
946 field->type, field->name, field->offset,
947 field->size, !!field->is_signed);
949 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
950 (int)(array_descriptor - field->type),
951 field->type, field->name,
952 array_descriptor, field->offset,
953 field->size, !!field->is_signed);
958 static void *f_start(struct seq_file *m, loff_t *pos)
960 void *p = (void *)FORMAT_HEADER;
963 /* ->stop() is called even if ->start() fails */
964 mutex_lock(&event_mutex);
965 if (!event_file_data(m->private))
966 return ERR_PTR(-ENODEV);
968 while (l < *pos && p)
969 p = f_next(m, p, &l);
974 static void f_stop(struct seq_file *m, void *p)
976 mutex_unlock(&event_mutex);
979 static const struct seq_operations trace_format_seq_ops = {
986 static int trace_format_open(struct inode *inode, struct file *file)
991 ret = seq_open(file, &trace_format_seq_ops);
995 m = file->private_data;
1002 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1004 int id = (long)event_file_data(filp);
1014 len = sprintf(buf, "%d\n", id);
1016 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1020 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1023 struct ftrace_event_file *file;
1024 struct trace_seq *s;
1030 s = kmalloc(sizeof(*s), GFP_KERNEL);
1037 mutex_lock(&event_mutex);
1038 file = event_file_data(filp);
1040 print_event_filter(file, s);
1041 mutex_unlock(&event_mutex);
1044 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1052 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1055 struct ftrace_event_file *file;
1059 if (cnt >= PAGE_SIZE)
1062 buf = (char *)__get_free_page(GFP_TEMPORARY);
1066 if (copy_from_user(buf, ubuf, cnt)) {
1067 free_page((unsigned long) buf);
1072 mutex_lock(&event_mutex);
1073 file = event_file_data(filp);
1075 err = apply_event_filter(file, buf);
1076 mutex_unlock(&event_mutex);
1078 free_page((unsigned long) buf);
1087 static LIST_HEAD(event_subsystems);
1089 static int subsystem_open(struct inode *inode, struct file *filp)
1091 struct event_subsystem *system = NULL;
1092 struct ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1093 struct trace_array *tr;
1096 if (tracing_is_disabled())
1099 /* Make sure the system still exists */
1100 mutex_lock(&trace_types_lock);
1101 mutex_lock(&event_mutex);
1102 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1103 list_for_each_entry(dir, &tr->systems, list) {
1104 if (dir == inode->i_private) {
1105 /* Don't open systems with no events */
1106 if (dir->nr_events) {
1107 __get_system_dir(dir);
1108 system = dir->subsystem;
1115 mutex_unlock(&event_mutex);
1116 mutex_unlock(&trace_types_lock);
1121 /* Some versions of gcc think dir can be uninitialized here */
1124 /* Still need to increment the ref count of the system */
1125 if (trace_array_get(tr) < 0) {
1130 ret = tracing_open_generic(inode, filp);
1132 trace_array_put(tr);
1139 static int system_tr_open(struct inode *inode, struct file *filp)
1141 struct ftrace_subsystem_dir *dir;
1142 struct trace_array *tr = inode->i_private;
1145 if (tracing_is_disabled())
1148 if (trace_array_get(tr) < 0)
1151 /* Make a temporary dir that has no system but points to tr */
1152 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1154 trace_array_put(tr);
1160 ret = tracing_open_generic(inode, filp);
1162 trace_array_put(tr);
1167 filp->private_data = dir;
1172 static int subsystem_release(struct inode *inode, struct file *file)
1174 struct ftrace_subsystem_dir *dir = file->private_data;
1176 trace_array_put(dir->tr);
1179 * If dir->subsystem is NULL, then this is a temporary
1180 * descriptor that was made for a trace_array to enable
1192 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1195 struct ftrace_subsystem_dir *dir = filp->private_data;
1196 struct event_subsystem *system = dir->subsystem;
1197 struct trace_seq *s;
1203 s = kmalloc(sizeof(*s), GFP_KERNEL);
1209 print_subsystem_event_filter(system, s);
1210 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1218 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1221 struct ftrace_subsystem_dir *dir = filp->private_data;
1225 if (cnt >= PAGE_SIZE)
1228 buf = (char *)__get_free_page(GFP_TEMPORARY);
1232 if (copy_from_user(buf, ubuf, cnt)) {
1233 free_page((unsigned long) buf);
1238 err = apply_subsystem_event_filter(dir, buf);
1239 free_page((unsigned long) buf);
1249 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1251 int (*func)(struct trace_seq *s) = filp->private_data;
1252 struct trace_seq *s;
1258 s = kmalloc(sizeof(*s), GFP_KERNEL);
1265 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1272 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1273 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1274 static int ftrace_event_release(struct inode *inode, struct file *file);
1276 static const struct seq_operations show_event_seq_ops = {
1283 static const struct seq_operations show_set_event_seq_ops = {
1290 static const struct file_operations ftrace_avail_fops = {
1291 .open = ftrace_event_avail_open,
1293 .llseek = seq_lseek,
1294 .release = seq_release,
1297 static const struct file_operations ftrace_set_event_fops = {
1298 .open = ftrace_event_set_open,
1300 .write = ftrace_event_write,
1301 .llseek = seq_lseek,
1302 .release = ftrace_event_release,
1305 static const struct file_operations ftrace_enable_fops = {
1306 .open = tracing_open_generic,
1307 .read = event_enable_read,
1308 .write = event_enable_write,
1309 .llseek = default_llseek,
1312 static const struct file_operations ftrace_event_format_fops = {
1313 .open = trace_format_open,
1315 .llseek = seq_lseek,
1316 .release = seq_release,
1319 static const struct file_operations ftrace_event_id_fops = {
1320 .read = event_id_read,
1321 .llseek = default_llseek,
1324 static const struct file_operations ftrace_event_filter_fops = {
1325 .open = tracing_open_generic,
1326 .read = event_filter_read,
1327 .write = event_filter_write,
1328 .llseek = default_llseek,
1331 static const struct file_operations ftrace_subsystem_filter_fops = {
1332 .open = subsystem_open,
1333 .read = subsystem_filter_read,
1334 .write = subsystem_filter_write,
1335 .llseek = default_llseek,
1336 .release = subsystem_release,
1339 static const struct file_operations ftrace_system_enable_fops = {
1340 .open = subsystem_open,
1341 .read = system_enable_read,
1342 .write = system_enable_write,
1343 .llseek = default_llseek,
1344 .release = subsystem_release,
1347 static const struct file_operations ftrace_tr_enable_fops = {
1348 .open = system_tr_open,
1349 .read = system_enable_read,
1350 .write = system_enable_write,
1351 .llseek = default_llseek,
1352 .release = subsystem_release,
1355 static const struct file_operations ftrace_show_header_fops = {
1356 .open = tracing_open_generic,
1357 .read = show_header,
1358 .llseek = default_llseek,
1362 ftrace_event_open(struct inode *inode, struct file *file,
1363 const struct seq_operations *seq_ops)
1368 ret = seq_open(file, seq_ops);
1371 m = file->private_data;
1372 /* copy tr over to seq ops */
1373 m->private = inode->i_private;
1378 static int ftrace_event_release(struct inode *inode, struct file *file)
1380 struct trace_array *tr = inode->i_private;
1382 trace_array_put(tr);
1384 return seq_release(inode, file);
1388 ftrace_event_avail_open(struct inode *inode, struct file *file)
1390 const struct seq_operations *seq_ops = &show_event_seq_ops;
1392 return ftrace_event_open(inode, file, seq_ops);
1396 ftrace_event_set_open(struct inode *inode, struct file *file)
1398 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1399 struct trace_array *tr = inode->i_private;
1402 if (trace_array_get(tr) < 0)
1405 if ((file->f_mode & FMODE_WRITE) &&
1406 (file->f_flags & O_TRUNC))
1407 ftrace_clear_events(tr);
1409 ret = ftrace_event_open(inode, file, seq_ops);
1411 trace_array_put(tr);
1415 static struct event_subsystem *
1416 create_new_subsystem(const char *name)
1418 struct event_subsystem *system;
1420 /* need to create new entry */
1421 system = kmalloc(sizeof(*system), GFP_KERNEL);
1425 system->ref_count = 1;
1427 /* Only allocate if dynamic (kprobes and modules) */
1428 if (!core_kernel_data((unsigned long)name)) {
1429 system->ref_count |= SYSTEM_FL_FREE_NAME;
1430 system->name = kstrdup(name, GFP_KERNEL);
1434 system->name = name;
1436 system->filter = NULL;
1438 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1439 if (!system->filter)
1442 list_add(&system->list, &event_subsystems);
1447 if (system->ref_count & SYSTEM_FL_FREE_NAME)
1448 kfree(system->name);
1453 static struct dentry *
1454 event_subsystem_dir(struct trace_array *tr, const char *name,
1455 struct ftrace_event_file *file, struct dentry *parent)
1457 struct ftrace_subsystem_dir *dir;
1458 struct event_subsystem *system;
1459 struct dentry *entry;
1461 /* First see if we did not already create this dir */
1462 list_for_each_entry(dir, &tr->systems, list) {
1463 system = dir->subsystem;
1464 if (strcmp(system->name, name) == 0) {
1471 /* Now see if the system itself exists. */
1472 list_for_each_entry(system, &event_subsystems, list) {
1473 if (strcmp(system->name, name) == 0)
1476 /* Reset system variable when not found */
1477 if (&system->list == &event_subsystems)
1480 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1485 system = create_new_subsystem(name);
1489 __get_system(system);
1491 dir->entry = debugfs_create_dir(name, parent);
1493 pr_warning("Failed to create system directory %s\n", name);
1494 __put_system(system);
1501 dir->subsystem = system;
1504 entry = debugfs_create_file("filter", 0644, dir->entry, dir,
1505 &ftrace_subsystem_filter_fops);
1507 kfree(system->filter);
1508 system->filter = NULL;
1509 pr_warning("Could not create debugfs '%s/filter' entry\n", name);
1512 trace_create_file("enable", 0644, dir->entry, dir,
1513 &ftrace_system_enable_fops);
1515 list_add(&dir->list, &tr->systems);
1522 /* Only print this message if failed on memory allocation */
1523 if (!dir || !system)
1524 pr_warning("No memory to create event subsystem %s\n",
1530 event_create_dir(struct dentry *parent, struct ftrace_event_file *file)
1532 struct ftrace_event_call *call = file->event_call;
1533 struct trace_array *tr = file->tr;
1534 struct list_head *head;
1535 struct dentry *d_events;
1540 * If the trace point header did not define TRACE_SYSTEM
1541 * then the system would be called "TRACE_SYSTEM".
1543 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1544 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1550 name = ftrace_event_name(call);
1551 file->dir = debugfs_create_dir(name, d_events);
1553 pr_warning("Could not create debugfs '%s' directory\n",
1558 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1559 trace_create_file("enable", 0644, file->dir, file,
1560 &ftrace_enable_fops);
1562 #ifdef CONFIG_PERF_EVENTS
1563 if (call->event.type && call->class->reg)
1564 trace_create_file("id", 0444, file->dir,
1565 (void *)(long)call->event.type,
1566 &ftrace_event_id_fops);
1570 * Other events may have the same class. Only update
1571 * the fields if they are not already defined.
1573 head = trace_get_fields(call);
1574 if (list_empty(head)) {
1575 ret = call->class->define_fields(call);
1577 pr_warning("Could not initialize trace point"
1578 " events/%s\n", name);
1582 trace_create_file("filter", 0644, file->dir, file,
1583 &ftrace_event_filter_fops);
1585 trace_create_file("trigger", 0644, file->dir, file,
1586 &event_trigger_fops);
1588 trace_create_file("format", 0444, file->dir, call,
1589 &ftrace_event_format_fops);
1594 static void remove_event_from_tracers(struct ftrace_event_call *call)
1596 struct ftrace_event_file *file;
1597 struct trace_array *tr;
1599 do_for_each_event_file_safe(tr, file) {
1600 if (file->event_call != call)
1603 remove_event_file_dir(file);
1605 * The do_for_each_event_file_safe() is
1606 * a double loop. After finding the call for this
1607 * trace_array, we use break to jump to the next
1611 } while_for_each_event_file();
1614 static void event_remove(struct ftrace_event_call *call)
1616 struct trace_array *tr;
1617 struct ftrace_event_file *file;
1619 do_for_each_event_file(tr, file) {
1620 if (file->event_call != call)
1622 ftrace_event_enable_disable(file, 0);
1623 destroy_preds(file);
1625 * The do_for_each_event_file() is
1626 * a double loop. After finding the call for this
1627 * trace_array, we use break to jump to the next
1631 } while_for_each_event_file();
1633 if (call->event.funcs)
1634 __unregister_ftrace_event(&call->event);
1635 remove_event_from_tracers(call);
1636 list_del(&call->list);
1639 static int event_init(struct ftrace_event_call *call)
1644 name = ftrace_event_name(call);
1648 if (call->class->raw_init) {
1649 ret = call->class->raw_init(call);
1650 if (ret < 0 && ret != -ENOSYS)
1651 pr_warn("Could not initialize trace events/%s\n",
1659 __register_event(struct ftrace_event_call *call, struct module *mod)
1663 ret = event_init(call);
1667 list_add(&call->list, &ftrace_events);
1673 static struct ftrace_event_file *
1674 trace_create_new_event(struct ftrace_event_call *call,
1675 struct trace_array *tr)
1677 struct ftrace_event_file *file;
1679 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
1683 file->event_call = call;
1685 atomic_set(&file->sm_ref, 0);
1686 atomic_set(&file->tm_ref, 0);
1687 INIT_LIST_HEAD(&file->triggers);
1688 list_add(&file->list, &tr->events);
1693 /* Add an event to a trace directory */
1695 __trace_add_new_event(struct ftrace_event_call *call, struct trace_array *tr)
1697 struct ftrace_event_file *file;
1699 file = trace_create_new_event(call, tr);
1703 return event_create_dir(tr->event_dir, file);
1707 * Just create a decriptor for early init. A descriptor is required
1708 * for enabling events at boot. We want to enable events before
1709 * the filesystem is initialized.
1712 __trace_early_add_new_event(struct ftrace_event_call *call,
1713 struct trace_array *tr)
1715 struct ftrace_event_file *file;
1717 file = trace_create_new_event(call, tr);
1724 struct ftrace_module_file_ops;
1725 static void __add_event_to_tracers(struct ftrace_event_call *call);
1727 /* Add an additional event_call dynamically */
1728 int trace_add_event_call(struct ftrace_event_call *call)
1731 mutex_lock(&trace_types_lock);
1732 mutex_lock(&event_mutex);
1734 ret = __register_event(call, NULL);
1736 __add_event_to_tracers(call);
1738 mutex_unlock(&event_mutex);
1739 mutex_unlock(&trace_types_lock);
1744 * Must be called under locking of trace_types_lock, event_mutex and
1747 static void __trace_remove_event_call(struct ftrace_event_call *call)
1750 trace_destroy_fields(call);
1751 destroy_call_preds(call);
1754 static int probe_remove_event_call(struct ftrace_event_call *call)
1756 struct trace_array *tr;
1757 struct ftrace_event_file *file;
1759 #ifdef CONFIG_PERF_EVENTS
1760 if (call->perf_refcount)
1763 do_for_each_event_file(tr, file) {
1764 if (file->event_call != call)
1767 * We can't rely on ftrace_event_enable_disable(enable => 0)
1768 * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
1769 * TRACE_REG_UNREGISTER.
1771 if (file->flags & FTRACE_EVENT_FL_ENABLED)
1774 * The do_for_each_event_file_safe() is
1775 * a double loop. After finding the call for this
1776 * trace_array, we use break to jump to the next
1780 } while_for_each_event_file();
1782 __trace_remove_event_call(call);
1787 /* Remove an event_call */
1788 int trace_remove_event_call(struct ftrace_event_call *call)
1792 mutex_lock(&trace_types_lock);
1793 mutex_lock(&event_mutex);
1794 down_write(&trace_event_sem);
1795 ret = probe_remove_event_call(call);
1796 up_write(&trace_event_sem);
1797 mutex_unlock(&event_mutex);
1798 mutex_unlock(&trace_types_lock);
1803 #define for_each_event(event, start, end) \
1804 for (event = start; \
1805 (unsigned long)event < (unsigned long)end; \
1808 #ifdef CONFIG_MODULES
1810 static void trace_module_add_events(struct module *mod)
1812 struct ftrace_event_call **call, **start, **end;
1814 if (!mod->num_trace_events)
1817 /* Don't add infrastructure for mods without tracepoints */
1818 if (trace_module_has_bad_taint(mod)) {
1819 pr_err("%s: module has bad taint, not creating trace events\n",
1824 start = mod->trace_events;
1825 end = mod->trace_events + mod->num_trace_events;
1827 for_each_event(call, start, end) {
1828 __register_event(*call, mod);
1829 __add_event_to_tracers(*call);
1833 static void trace_module_remove_events(struct module *mod)
1835 struct ftrace_event_call *call, *p;
1836 bool clear_trace = false;
1838 down_write(&trace_event_sem);
1839 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1840 if (call->mod == mod) {
1841 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
1843 __trace_remove_event_call(call);
1846 up_write(&trace_event_sem);
1849 * It is safest to reset the ring buffer if the module being unloaded
1850 * registered any events that were used. The only worry is if
1851 * a new module gets loaded, and takes on the same id as the events
1852 * of this module. When printing out the buffer, traced events left
1853 * over from this module may be passed to the new module events and
1854 * unexpected results may occur.
1857 tracing_reset_all_online_cpus();
1860 static int trace_module_notify(struct notifier_block *self,
1861 unsigned long val, void *data)
1863 struct module *mod = data;
1865 mutex_lock(&trace_types_lock);
1866 mutex_lock(&event_mutex);
1868 case MODULE_STATE_COMING:
1869 trace_module_add_events(mod);
1871 case MODULE_STATE_GOING:
1872 trace_module_remove_events(mod);
1875 mutex_unlock(&event_mutex);
1876 mutex_unlock(&trace_types_lock);
1881 static struct notifier_block trace_module_nb = {
1882 .notifier_call = trace_module_notify,
1885 #endif /* CONFIG_MODULES */
1887 /* Create a new event directory structure for a trace directory. */
1889 __trace_add_event_dirs(struct trace_array *tr)
1891 struct ftrace_event_call *call;
1894 list_for_each_entry(call, &ftrace_events, list) {
1895 ret = __trace_add_new_event(call, tr);
1897 pr_warning("Could not create directory for event %s\n",
1898 ftrace_event_name(call));
1902 struct ftrace_event_file *
1903 find_event_file(struct trace_array *tr, const char *system, const char *event)
1905 struct ftrace_event_file *file;
1906 struct ftrace_event_call *call;
1909 list_for_each_entry(file, &tr->events, list) {
1911 call = file->event_call;
1912 name = ftrace_event_name(call);
1914 if (!name || !call->class || !call->class->reg)
1917 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1920 if (strcmp(event, name) == 0 &&
1921 strcmp(system, call->class->system) == 0)
1927 #ifdef CONFIG_DYNAMIC_FTRACE
1930 #define ENABLE_EVENT_STR "enable_event"
1931 #define DISABLE_EVENT_STR "disable_event"
1933 struct event_probe_data {
1934 struct ftrace_event_file *file;
1935 unsigned long count;
1941 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1943 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1944 struct event_probe_data *data = *pdata;
1950 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1952 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1956 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1958 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1959 struct event_probe_data *data = *pdata;
1967 /* Skip if the event is in a state we want to switch to */
1968 if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
1971 if (data->count != -1)
1974 event_enable_probe(ip, parent_ip, _data);
1978 event_enable_print(struct seq_file *m, unsigned long ip,
1979 struct ftrace_probe_ops *ops, void *_data)
1981 struct event_probe_data *data = _data;
1983 seq_printf(m, "%ps:", (void *)ip);
1985 seq_printf(m, "%s:%s:%s",
1986 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
1987 data->file->event_call->class->system,
1988 ftrace_event_name(data->file->event_call));
1990 if (data->count == -1)
1991 seq_printf(m, ":unlimited\n");
1993 seq_printf(m, ":count=%ld\n", data->count);
1999 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
2002 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2003 struct event_probe_data *data = *pdata;
2010 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
2013 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2014 struct event_probe_data *data = *pdata;
2016 if (WARN_ON_ONCE(data->ref <= 0))
2021 /* Remove the SOFT_MODE flag */
2022 __ftrace_event_enable_disable(data->file, 0, 1);
2023 module_put(data->file->event_call->mod);
2029 static struct ftrace_probe_ops event_enable_probe_ops = {
2030 .func = event_enable_probe,
2031 .print = event_enable_print,
2032 .init = event_enable_init,
2033 .free = event_enable_free,
2036 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2037 .func = event_enable_count_probe,
2038 .print = event_enable_print,
2039 .init = event_enable_init,
2040 .free = event_enable_free,
2043 static struct ftrace_probe_ops event_disable_probe_ops = {
2044 .func = event_enable_probe,
2045 .print = event_enable_print,
2046 .init = event_enable_init,
2047 .free = event_enable_free,
2050 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2051 .func = event_enable_count_probe,
2052 .print = event_enable_print,
2053 .init = event_enable_init,
2054 .free = event_enable_free,
2058 event_enable_func(struct ftrace_hash *hash,
2059 char *glob, char *cmd, char *param, int enabled)
2061 struct trace_array *tr = top_trace_array();
2062 struct ftrace_event_file *file;
2063 struct ftrace_probe_ops *ops;
2064 struct event_probe_data *data;
2074 /* hash funcs only work with set_ftrace_filter */
2075 if (!enabled || !param)
2078 system = strsep(¶m, ":");
2082 event = strsep(¶m, ":");
2084 mutex_lock(&event_mutex);
2087 file = find_event_file(tr, system, event);
2091 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2094 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2096 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2098 if (glob[0] == '!') {
2099 unregister_ftrace_function_probe_func(glob+1, ops);
2105 data = kzalloc(sizeof(*data), GFP_KERNEL);
2109 data->enable = enable;
2116 number = strsep(¶m, ":");
2119 if (!strlen(number))
2123 * We use the callback data field (which is a pointer)
2126 ret = kstrtoul(number, 0, &data->count);
2131 /* Don't let event modules unload while probe registered */
2132 ret = try_module_get(file->event_call->mod);
2138 ret = __ftrace_event_enable_disable(file, 1, 1);
2141 ret = register_ftrace_function_probe(glob, ops, data);
2143 * The above returns on success the # of functions enabled,
2144 * but if it didn't find any functions it returns zero.
2145 * Consider no functions a failure too.
2152 /* Just return zero, not the number of enabled functions */
2155 mutex_unlock(&event_mutex);
2159 __ftrace_event_enable_disable(file, 0, 1);
2161 module_put(file->event_call->mod);
2167 static struct ftrace_func_command event_enable_cmd = {
2168 .name = ENABLE_EVENT_STR,
2169 .func = event_enable_func,
2172 static struct ftrace_func_command event_disable_cmd = {
2173 .name = DISABLE_EVENT_STR,
2174 .func = event_enable_func,
2177 static __init int register_event_cmds(void)
2181 ret = register_ftrace_command(&event_enable_cmd);
2182 if (WARN_ON(ret < 0))
2184 ret = register_ftrace_command(&event_disable_cmd);
2185 if (WARN_ON(ret < 0))
2186 unregister_ftrace_command(&event_enable_cmd);
2190 static inline int register_event_cmds(void) { return 0; }
2191 #endif /* CONFIG_DYNAMIC_FTRACE */
2194 * The top level array has already had its ftrace_event_file
2195 * descriptors created in order to allow for early events to
2196 * be recorded. This function is called after the debugfs has been
2197 * initialized, and we now have to create the files associated
2201 __trace_early_add_event_dirs(struct trace_array *tr)
2203 struct ftrace_event_file *file;
2207 list_for_each_entry(file, &tr->events, list) {
2208 ret = event_create_dir(tr->event_dir, file);
2210 pr_warning("Could not create directory for event %s\n",
2211 ftrace_event_name(file->event_call));
2216 * For early boot up, the top trace array requires to have
2217 * a list of events that can be enabled. This must be done before
2218 * the filesystem is set up in order to allow events to be traced
2222 __trace_early_add_events(struct trace_array *tr)
2224 struct ftrace_event_call *call;
2227 list_for_each_entry(call, &ftrace_events, list) {
2228 /* Early boot up should not have any modules loaded */
2229 if (WARN_ON_ONCE(call->mod))
2232 ret = __trace_early_add_new_event(call, tr);
2234 pr_warning("Could not create early event %s\n",
2235 ftrace_event_name(call));
2239 /* Remove the event directory structure for a trace directory. */
2241 __trace_remove_event_dirs(struct trace_array *tr)
2243 struct ftrace_event_file *file, *next;
2245 list_for_each_entry_safe(file, next, &tr->events, list)
2246 remove_event_file_dir(file);
2249 static void __add_event_to_tracers(struct ftrace_event_call *call)
2251 struct trace_array *tr;
2253 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2254 __trace_add_new_event(call, tr);
2257 extern struct ftrace_event_call *__start_ftrace_events[];
2258 extern struct ftrace_event_call *__stop_ftrace_events[];
2260 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2262 static __init int setup_trace_event(char *str)
2264 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2265 ring_buffer_expanded = true;
2266 tracing_selftest_disabled = true;
2270 __setup("trace_event=", setup_trace_event);
2272 /* Expects to have event_mutex held when called */
2274 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2276 struct dentry *d_events;
2277 struct dentry *entry;
2279 entry = debugfs_create_file("set_event", 0644, parent,
2280 tr, &ftrace_set_event_fops);
2282 pr_warning("Could not create debugfs 'set_event' entry\n");
2286 d_events = debugfs_create_dir("events", parent);
2288 pr_warning("Could not create debugfs 'events' directory\n");
2292 /* ring buffer internal formats */
2293 trace_create_file("header_page", 0444, d_events,
2294 ring_buffer_print_page_header,
2295 &ftrace_show_header_fops);
2297 trace_create_file("header_event", 0444, d_events,
2298 ring_buffer_print_entry_header,
2299 &ftrace_show_header_fops);
2301 trace_create_file("enable", 0644, d_events,
2302 tr, &ftrace_tr_enable_fops);
2304 tr->event_dir = d_events;
2310 * event_trace_add_tracer - add a instance of a trace_array to events
2311 * @parent: The parent dentry to place the files/directories for events in
2312 * @tr: The trace array associated with these events
2314 * When a new instance is created, it needs to set up its events
2315 * directory, as well as other files associated with events. It also
2316 * creates the event hierachry in the @parent/events directory.
2318 * Returns 0 on success.
2320 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2324 mutex_lock(&event_mutex);
2326 ret = create_event_toplevel_files(parent, tr);
2330 down_write(&trace_event_sem);
2331 __trace_add_event_dirs(tr);
2332 up_write(&trace_event_sem);
2335 mutex_unlock(&event_mutex);
2341 * The top trace array already had its file descriptors created.
2342 * Now the files themselves need to be created.
2345 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2349 mutex_lock(&event_mutex);
2351 ret = create_event_toplevel_files(parent, tr);
2355 down_write(&trace_event_sem);
2356 __trace_early_add_event_dirs(tr);
2357 up_write(&trace_event_sem);
2360 mutex_unlock(&event_mutex);
2365 int event_trace_del_tracer(struct trace_array *tr)
2367 mutex_lock(&event_mutex);
2369 /* Disable any event triggers and associated soft-disabled events */
2370 clear_event_triggers(tr);
2372 /* Disable any running events */
2373 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
2375 /* Access to events are within rcu_read_lock_sched() */
2376 synchronize_sched();
2378 down_write(&trace_event_sem);
2379 __trace_remove_event_dirs(tr);
2380 debugfs_remove_recursive(tr->event_dir);
2381 up_write(&trace_event_sem);
2383 tr->event_dir = NULL;
2385 mutex_unlock(&event_mutex);
2390 static __init int event_trace_memsetup(void)
2392 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
2393 file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC);
2397 static __init int event_trace_enable(void)
2399 struct trace_array *tr = top_trace_array();
2400 struct ftrace_event_call **iter, *call;
2401 char *buf = bootup_event_buf;
2408 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
2411 ret = event_init(call);
2413 list_add(&call->list, &ftrace_events);
2417 * We need the top trace array to have a working set of trace
2418 * points at early init, before the debug files and directories
2419 * are created. Create the file entries now, and attach them
2420 * to the actual file dentries later.
2422 __trace_early_add_events(tr);
2425 token = strsep(&buf, ",");
2432 ret = ftrace_set_clr_event(tr, token, 1);
2434 pr_warn("Failed to enable trace event: %s\n", token);
2437 trace_printk_start_comm();
2439 register_event_cmds();
2441 register_trigger_cmds();
2446 static __init int event_trace_init(void)
2448 struct trace_array *tr;
2449 struct dentry *d_tracer;
2450 struct dentry *entry;
2453 tr = top_trace_array();
2457 d_tracer = tracing_init_dentry();
2461 entry = debugfs_create_file("available_events", 0444, d_tracer,
2462 tr, &ftrace_avail_fops);
2464 pr_warning("Could not create debugfs "
2465 "'available_events' entry\n");
2467 if (trace_define_common_fields())
2468 pr_warning("tracing: Failed to allocate common fields");
2470 ret = early_event_add_tracer(d_tracer, tr);
2474 #ifdef CONFIG_MODULES
2475 ret = register_module_notifier(&trace_module_nb);
2477 pr_warning("Failed to register trace events module notifier\n");
2481 early_initcall(event_trace_memsetup);
2482 core_initcall(event_trace_enable);
2483 fs_initcall(event_trace_init);
2485 #ifdef CONFIG_FTRACE_STARTUP_TEST
2487 static DEFINE_SPINLOCK(test_spinlock);
2488 static DEFINE_SPINLOCK(test_spinlock_irq);
2489 static DEFINE_MUTEX(test_mutex);
2491 static __init void test_work(struct work_struct *dummy)
2493 spin_lock(&test_spinlock);
2494 spin_lock_irq(&test_spinlock_irq);
2496 spin_unlock_irq(&test_spinlock_irq);
2497 spin_unlock(&test_spinlock);
2499 mutex_lock(&test_mutex);
2501 mutex_unlock(&test_mutex);
2504 static __init int event_test_thread(void *unused)
2508 test_malloc = kmalloc(1234, GFP_KERNEL);
2510 pr_info("failed to kmalloc\n");
2512 schedule_on_each_cpu(test_work);
2516 set_current_state(TASK_INTERRUPTIBLE);
2517 while (!kthread_should_stop())
2524 * Do various things that may trigger events.
2526 static __init void event_test_stuff(void)
2528 struct task_struct *test_thread;
2530 test_thread = kthread_run(event_test_thread, NULL, "test-events");
2532 kthread_stop(test_thread);
2536 * For every trace event defined, we will test each trace point separately,
2537 * and then by groups, and finally all trace points.
2539 static __init void event_trace_self_tests(void)
2541 struct ftrace_subsystem_dir *dir;
2542 struct ftrace_event_file *file;
2543 struct ftrace_event_call *call;
2544 struct event_subsystem *system;
2545 struct trace_array *tr;
2548 tr = top_trace_array();
2552 pr_info("Running tests on trace events:\n");
2554 list_for_each_entry(file, &tr->events, list) {
2556 call = file->event_call;
2558 /* Only test those that have a probe */
2559 if (!call->class || !call->class->probe)
2563 * Testing syscall events here is pretty useless, but
2564 * we still do it if configured. But this is time consuming.
2565 * What we really need is a user thread to perform the
2566 * syscalls as we test.
2568 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
2569 if (call->class->system &&
2570 strcmp(call->class->system, "syscalls") == 0)
2574 pr_info("Testing event %s: ", ftrace_event_name(call));
2577 * If an event is already enabled, someone is using
2578 * it and the self test should not be on.
2580 if (file->flags & FTRACE_EVENT_FL_ENABLED) {
2581 pr_warning("Enabled event during self test!\n");
2586 ftrace_event_enable_disable(file, 1);
2588 ftrace_event_enable_disable(file, 0);
2593 /* Now test at the sub system level */
2595 pr_info("Running tests on trace event systems:\n");
2597 list_for_each_entry(dir, &tr->systems, list) {
2599 system = dir->subsystem;
2601 /* the ftrace system is special, skip it */
2602 if (strcmp(system->name, "ftrace") == 0)
2605 pr_info("Testing event system %s: ", system->name);
2607 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
2608 if (WARN_ON_ONCE(ret)) {
2609 pr_warning("error enabling system %s\n",
2616 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
2617 if (WARN_ON_ONCE(ret)) {
2618 pr_warning("error disabling system %s\n",
2626 /* Test with all events enabled */
2628 pr_info("Running tests on all trace events:\n");
2629 pr_info("Testing all events: ");
2631 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
2632 if (WARN_ON_ONCE(ret)) {
2633 pr_warning("error enabling all events\n");
2640 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
2641 if (WARN_ON_ONCE(ret)) {
2642 pr_warning("error disabling all events\n");
2649 #ifdef CONFIG_FUNCTION_TRACER
2651 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
2654 function_test_events_call(unsigned long ip, unsigned long parent_ip,
2655 struct ftrace_ops *op, struct pt_regs *pt_regs)
2657 struct ring_buffer_event *event;
2658 struct ring_buffer *buffer;
2659 struct ftrace_entry *entry;
2660 unsigned long flags;
2665 pc = preempt_count();
2666 preempt_disable_notrace();
2667 cpu = raw_smp_processor_id();
2668 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
2673 local_save_flags(flags);
2675 event = trace_current_buffer_lock_reserve(&buffer,
2676 TRACE_FN, sizeof(*entry),
2680 entry = ring_buffer_event_data(event);
2682 entry->parent_ip = parent_ip;
2684 trace_buffer_unlock_commit(buffer, event, flags, pc);
2687 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
2688 preempt_enable_notrace();
2691 static struct ftrace_ops trace_ops __initdata =
2693 .func = function_test_events_call,
2694 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
2697 static __init void event_trace_self_test_with_function(void)
2700 ret = register_ftrace_function(&trace_ops);
2701 if (WARN_ON(ret < 0)) {
2702 pr_info("Failed to enable function tracer for event tests\n");
2705 pr_info("Running tests again, along with the function tracer\n");
2706 event_trace_self_tests();
2707 unregister_ftrace_function(&trace_ops);
2710 static __init void event_trace_self_test_with_function(void)
2715 static __init int event_trace_self_tests_init(void)
2717 if (!tracing_selftest_disabled) {
2718 event_trace_self_tests();
2719 event_trace_self_test_with_function();
2725 late_initcall(event_trace_self_tests_init);