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/delay.h>
20 #include "trace_output.h"
22 #define TRACE_SYSTEM "TRACE_SYSTEM"
24 static DEFINE_MUTEX(event_mutex);
26 LIST_HEAD(ftrace_events);
28 int trace_define_field(struct ftrace_event_call *call, char *type,
29 char *name, int offset, int size)
31 struct ftrace_event_field *field;
33 field = kzalloc(sizeof(*field), GFP_KERNEL);
37 field->name = kstrdup(name, GFP_KERNEL);
41 field->type = kstrdup(type, GFP_KERNEL);
45 field->offset = offset;
47 list_add(&field->link, &call->fields);
60 EXPORT_SYMBOL_GPL(trace_define_field);
62 static void ftrace_clear_events(void)
64 struct ftrace_event_call *call;
66 list_for_each_entry(call, &ftrace_events, list) {
75 static void ftrace_event_enable_disable(struct ftrace_event_call *call,
95 static int ftrace_set_clr_event(char *buf, int set)
97 struct ftrace_event_call *call;
98 char *event = NULL, *sub = NULL, *match;
102 * The buf format can be <subsystem>:<event-name>
103 * *:<event-name> means any event by that name.
104 * :<event-name> is the same.
106 * <subsystem>:* means all events in that subsystem
107 * <subsystem>: means the same.
109 * <name> (no ':') means all events in a subsystem with
110 * the name <name> or any event that matches <name>
113 match = strsep(&buf, ":");
119 if (!strlen(sub) || strcmp(sub, "*") == 0)
121 if (!strlen(event) || strcmp(event, "*") == 0)
125 mutex_lock(&event_mutex);
126 list_for_each_entry(call, &ftrace_events, list) {
128 if (!call->name || !call->regfunc)
132 strcmp(match, call->name) != 0 &&
133 strcmp(match, call->system) != 0)
136 if (sub && strcmp(sub, call->system) != 0)
139 if (event && strcmp(event, call->name) != 0)
142 ftrace_event_enable_disable(call, set);
146 mutex_unlock(&event_mutex);
151 /* 128 should be much more than enough */
152 #define EVENT_BUF_SIZE 127
155 ftrace_event_write(struct file *file, const char __user *ubuf,
156 size_t cnt, loff_t *ppos)
167 ret = tracing_update_buffers();
171 ret = get_user(ch, ubuf++);
177 /* skip white space */
178 while (cnt && isspace(ch)) {
179 ret = get_user(ch, ubuf++);
186 /* Only white space found? */
193 buf = kmalloc(EVENT_BUF_SIZE+1, GFP_KERNEL);
197 if (cnt > EVENT_BUF_SIZE)
198 cnt = EVENT_BUF_SIZE;
201 while (cnt && !isspace(ch)) {
207 ret = get_user(ch, ubuf++);
217 ret = ftrace_set_clr_event(buf, set);
230 t_next(struct seq_file *m, void *v, loff_t *pos)
232 struct list_head *list = m->private;
233 struct ftrace_event_call *call;
238 if (list == &ftrace_events)
241 call = list_entry(list, struct ftrace_event_call, list);
244 * The ftrace subsystem is for showing formats only.
245 * They can not be enabled or disabled via the event files.
253 m->private = list->next;
258 static void *t_start(struct seq_file *m, loff_t *pos)
260 return t_next(m, NULL, pos);
264 s_next(struct seq_file *m, void *v, loff_t *pos)
266 struct list_head *list = m->private;
267 struct ftrace_event_call *call;
272 if (list == &ftrace_events)
275 call = list_entry(list, struct ftrace_event_call, list);
277 if (!call->enabled) {
282 m->private = list->next;
287 static void *s_start(struct seq_file *m, loff_t *pos)
289 return s_next(m, NULL, pos);
292 static int t_show(struct seq_file *m, void *v)
294 struct ftrace_event_call *call = v;
296 if (strcmp(call->system, TRACE_SYSTEM) != 0)
297 seq_printf(m, "%s:", call->system);
298 seq_printf(m, "%s\n", call->name);
303 static void t_stop(struct seq_file *m, void *p)
308 ftrace_event_seq_open(struct inode *inode, struct file *file)
311 const struct seq_operations *seq_ops;
313 if ((file->f_mode & FMODE_WRITE) &&
314 !(file->f_flags & O_APPEND))
315 ftrace_clear_events();
317 seq_ops = inode->i_private;
318 ret = seq_open(file, seq_ops);
320 struct seq_file *m = file->private_data;
322 m->private = ftrace_events.next;
328 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
331 struct ftrace_event_call *call = filp->private_data;
339 return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
343 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
346 struct ftrace_event_call *call = filp->private_data;
351 if (cnt >= sizeof(buf))
354 if (copy_from_user(&buf, ubuf, cnt))
359 ret = strict_strtoul(buf, 10, &val);
363 ret = tracing_update_buffers();
370 mutex_lock(&event_mutex);
371 ftrace_event_enable_disable(call, val);
372 mutex_unlock(&event_mutex);
385 #define FIELD(type, name) \
386 #type, "common_" #name, offsetof(typeof(field), name), \
389 static int trace_write_header(struct trace_seq *s)
391 struct trace_entry field;
393 /* struct trace_entry */
394 return trace_seq_printf(s,
395 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
396 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
397 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
398 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
399 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
401 FIELD(unsigned char, type),
402 FIELD(unsigned char, flags),
403 FIELD(unsigned char, preempt_count),
409 event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
412 struct ftrace_event_call *call = filp->private_data;
420 s = kmalloc(sizeof(*s), GFP_KERNEL);
426 /* If any of the first writes fail, so will the show_format. */
428 trace_seq_printf(s, "name: %s\n", call->name);
429 trace_seq_printf(s, "ID: %d\n", call->id);
430 trace_seq_printf(s, "format:\n");
431 trace_write_header(s);
433 r = call->show_format(s);
436 * ug! The format output is bigger than a PAGE!!
438 buf = "FORMAT TOO BIG\n";
439 r = simple_read_from_buffer(ubuf, cnt, ppos,
444 r = simple_read_from_buffer(ubuf, cnt, ppos,
452 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
454 struct ftrace_event_call *call = filp->private_data;
461 s = kmalloc(sizeof(*s), GFP_KERNEL);
466 trace_seq_printf(s, "%d\n", call->id);
468 r = simple_read_from_buffer(ubuf, cnt, ppos,
475 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
478 struct ftrace_event_call *call = filp->private_data;
485 s = kmalloc(sizeof(*s), GFP_KERNEL);
491 filter_print_preds(call->preds, call->n_preds, s);
492 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
500 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
503 struct ftrace_event_call *call = filp->private_data;
504 char buf[64], *pbuf = buf;
505 struct filter_pred *pred;
508 if (cnt >= sizeof(buf))
511 if (copy_from_user(&buf, ubuf, cnt))
515 pred = kzalloc(sizeof(*pred), GFP_KERNEL);
519 err = filter_parse(&pbuf, pred);
521 filter_free_pred(pred);
526 filter_disable_preds(call);
527 filter_free_pred(pred);
531 err = filter_add_pred(call, pred);
533 filter_free_pred(pred);
537 filter_free_pred(pred);
545 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
548 struct event_subsystem *system = filp->private_data;
555 s = kmalloc(sizeof(*s), GFP_KERNEL);
561 filter_print_preds(system->preds, system->n_preds, s);
562 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
570 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
573 struct event_subsystem *system = filp->private_data;
574 char buf[64], *pbuf = buf;
575 struct filter_pred *pred;
578 if (cnt >= sizeof(buf))
581 if (copy_from_user(&buf, ubuf, cnt))
585 pred = kzalloc(sizeof(*pred), GFP_KERNEL);
589 err = filter_parse(&pbuf, pred);
591 filter_free_pred(pred);
596 filter_free_subsystem_preds(system);
597 filter_free_pred(pred);
601 err = filter_add_subsystem_pred(system, pred);
603 filter_free_subsystem_preds(system);
604 filter_free_pred(pred);
613 static const struct seq_operations show_event_seq_ops = {
620 static const struct seq_operations show_set_event_seq_ops = {
627 static const struct file_operations ftrace_avail_fops = {
628 .open = ftrace_event_seq_open,
631 .release = seq_release,
634 static const struct file_operations ftrace_set_event_fops = {
635 .open = ftrace_event_seq_open,
637 .write = ftrace_event_write,
639 .release = seq_release,
642 static const struct file_operations ftrace_enable_fops = {
643 .open = tracing_open_generic,
644 .read = event_enable_read,
645 .write = event_enable_write,
648 static const struct file_operations ftrace_event_format_fops = {
649 .open = tracing_open_generic,
650 .read = event_format_read,
653 static const struct file_operations ftrace_event_id_fops = {
654 .open = tracing_open_generic,
655 .read = event_id_read,
658 static const struct file_operations ftrace_event_filter_fops = {
659 .open = tracing_open_generic,
660 .read = event_filter_read,
661 .write = event_filter_write,
664 static const struct file_operations ftrace_subsystem_filter_fops = {
665 .open = tracing_open_generic,
666 .read = subsystem_filter_read,
667 .write = subsystem_filter_write,
670 static struct dentry *event_trace_events_dir(void)
672 static struct dentry *d_tracer;
673 static struct dentry *d_events;
678 d_tracer = tracing_init_dentry();
682 d_events = debugfs_create_dir("events", d_tracer);
684 pr_warning("Could not create debugfs "
685 "'events' directory\n");
690 static LIST_HEAD(event_subsystems);
692 static struct dentry *
693 event_subsystem_dir(const char *name, struct dentry *d_events)
695 struct event_subsystem *system;
696 struct dentry *entry;
698 /* First see if we did not already create this dir */
699 list_for_each_entry(system, &event_subsystems, list) {
700 if (strcmp(system->name, name) == 0)
701 return system->entry;
704 /* need to create new entry */
705 system = kmalloc(sizeof(*system), GFP_KERNEL);
707 pr_warning("No memory to create event subsystem %s\n",
712 system->entry = debugfs_create_dir(name, d_events);
713 if (!system->entry) {
714 pr_warning("Could not create event subsystem %s\n",
720 system->name = kstrdup(name, GFP_KERNEL);
722 debugfs_remove(system->entry);
727 list_add(&system->list, &event_subsystems);
729 system->preds = NULL;
732 entry = debugfs_create_file("filter", 0644, system->entry, system,
733 &ftrace_subsystem_filter_fops);
735 pr_warning("Could not create debugfs "
736 "'%s/filter' entry\n", name);
738 return system->entry;
742 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events)
744 struct dentry *entry;
748 * If the trace point header did not define TRACE_SYSTEM
749 * then the system would be called "TRACE_SYSTEM".
751 if (strcmp(call->system, TRACE_SYSTEM) != 0)
752 d_events = event_subsystem_dir(call->system, d_events);
754 if (call->raw_init) {
755 ret = call->raw_init();
757 pr_warning("Could not initialize trace point"
758 " events/%s\n", call->name);
763 call->dir = debugfs_create_dir(call->name, d_events);
765 pr_warning("Could not create debugfs "
766 "'%s' directory\n", call->name);
771 entry = trace_create_file("enable", 0644, call->dir, call,
772 &ftrace_enable_fops);
775 entry = trace_create_file("id", 0444, call->dir, call,
776 &ftrace_event_id_fops);
778 if (call->define_fields) {
779 ret = call->define_fields();
781 pr_warning("Could not initialize trace point"
782 " events/%s\n", call->name);
785 entry = trace_create_file("filter", 0644, call->dir, call,
786 &ftrace_event_filter_fops);
789 /* A trace may not want to export its format */
790 if (!call->show_format)
793 entry = trace_create_file("format", 0444, call->dir, call,
794 &ftrace_event_format_fops);
799 #define for_each_event(event, start, end) \
800 for (event = start; \
801 (unsigned long)event < (unsigned long)end; \
804 #ifdef CONFIG_MODULES
805 static void trace_module_add_events(struct module *mod)
807 struct ftrace_event_call *call, *start, *end;
808 struct dentry *d_events;
810 start = mod->trace_events;
811 end = mod->trace_events + mod->num_trace_events;
816 d_events = event_trace_events_dir();
820 for_each_event(call, start, end) {
821 /* The linker may leave blanks */
825 list_add(&call->list, &ftrace_events);
826 event_create_dir(call, d_events);
830 static void trace_module_remove_events(struct module *mod)
832 struct ftrace_event_call *call, *p;
834 list_for_each_entry_safe(call, p, &ftrace_events, list) {
835 if (call->mod == mod) {
841 unregister_ftrace_event(call->event);
842 debugfs_remove_recursive(call->dir);
843 list_del(&call->list);
848 static int trace_module_notify(struct notifier_block *self,
849 unsigned long val, void *data)
851 struct module *mod = data;
853 mutex_lock(&event_mutex);
855 case MODULE_STATE_COMING:
856 trace_module_add_events(mod);
858 case MODULE_STATE_GOING:
859 trace_module_remove_events(mod);
862 mutex_unlock(&event_mutex);
867 static int trace_module_notify(struct notifier_block *self,
868 unsigned long val, void *data)
872 #endif /* CONFIG_MODULES */
874 struct notifier_block trace_module_nb = {
875 .notifier_call = trace_module_notify,
879 extern struct ftrace_event_call __start_ftrace_events[];
880 extern struct ftrace_event_call __stop_ftrace_events[];
882 static __init int event_trace_init(void)
884 struct ftrace_event_call *call;
885 struct dentry *d_tracer;
886 struct dentry *entry;
887 struct dentry *d_events;
890 d_tracer = tracing_init_dentry();
894 entry = debugfs_create_file("available_events", 0444, d_tracer,
895 (void *)&show_event_seq_ops,
898 pr_warning("Could not create debugfs "
899 "'available_events' entry\n");
901 entry = debugfs_create_file("set_event", 0644, d_tracer,
902 (void *)&show_set_event_seq_ops,
903 &ftrace_set_event_fops);
905 pr_warning("Could not create debugfs "
906 "'set_event' entry\n");
908 d_events = event_trace_events_dir();
912 for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
913 /* The linker may leave blanks */
916 list_add(&call->list, &ftrace_events);
917 event_create_dir(call, d_events);
920 ret = register_module_notifier(&trace_module_nb);
922 pr_warning("Failed to register trace events module notifier\n");
926 fs_initcall(event_trace_init);
928 #ifdef CONFIG_FTRACE_STARTUP_TEST
930 static DEFINE_SPINLOCK(test_spinlock);
931 static DEFINE_SPINLOCK(test_spinlock_irq);
932 static DEFINE_MUTEX(test_mutex);
934 static __init void test_work(struct work_struct *dummy)
936 spin_lock(&test_spinlock);
937 spin_lock_irq(&test_spinlock_irq);
939 spin_unlock_irq(&test_spinlock_irq);
940 spin_unlock(&test_spinlock);
942 mutex_lock(&test_mutex);
944 mutex_unlock(&test_mutex);
947 static __init int event_test_thread(void *unused)
951 test_malloc = kmalloc(1234, GFP_KERNEL);
953 pr_info("failed to kmalloc\n");
955 schedule_on_each_cpu(test_work);
959 set_current_state(TASK_INTERRUPTIBLE);
960 while (!kthread_should_stop())
967 * Do various things that may trigger events.
969 static __init void event_test_stuff(void)
971 struct task_struct *test_thread;
973 test_thread = kthread_run(event_test_thread, NULL, "test-events");
975 kthread_stop(test_thread);
979 * For every trace event defined, we will test each trace point separately,
980 * and then by groups, and finally all trace points.
982 static __init int event_trace_self_tests(void)
984 struct ftrace_event_call *call;
985 struct event_subsystem *system;
989 pr_info("Running tests on trace events:\n");
991 list_for_each_entry(call, &ftrace_events, list) {
993 /* Only test those that have a regfunc */
997 pr_info("Testing event %s: ", call->name);
1000 * If an event is already enabled, someone is using
1001 * it and the self test should not be on.
1003 if (call->enabled) {
1004 pr_warning("Enabled event during self test!\n");
1020 /* Now test at the sub system level */
1022 pr_info("Running tests on trace event systems:\n");
1024 list_for_each_entry(system, &event_subsystems, list) {
1026 /* the ftrace system is special, skip it */
1027 if (strcmp(system->name, "ftrace") == 0)
1030 pr_info("Testing event system %s: ", system->name);
1032 /* ftrace_set_clr_event can modify the name passed in. */
1033 sysname = kstrdup(system->name, GFP_KERNEL);
1034 if (WARN_ON(!sysname)) {
1035 pr_warning("Can't allocate memory, giving up!\n");
1038 ret = ftrace_set_clr_event(sysname, 1);
1040 if (WARN_ON_ONCE(ret)) {
1041 pr_warning("error enabling system %s\n",
1048 sysname = kstrdup(system->name, GFP_KERNEL);
1049 if (WARN_ON(!sysname)) {
1050 pr_warning("Can't allocate memory, giving up!\n");
1053 ret = ftrace_set_clr_event(sysname, 0);
1056 if (WARN_ON_ONCE(ret))
1057 pr_warning("error disabling system %s\n",
1063 /* Test with all events enabled */
1065 pr_info("Running tests on all trace events:\n");
1066 pr_info("Testing all events: ");
1068 sysname = kmalloc(4, GFP_KERNEL);
1069 if (WARN_ON(!sysname)) {
1070 pr_warning("Can't allocate memory, giving up!\n");
1073 memcpy(sysname, "*:*", 4);
1074 ret = ftrace_set_clr_event(sysname, 1);
1075 if (WARN_ON_ONCE(ret)) {
1077 pr_warning("error enabling all events\n");
1084 memcpy(sysname, "*:*", 4);
1085 ret = ftrace_set_clr_event(sysname, 0);
1088 if (WARN_ON_ONCE(ret)) {
1089 pr_warning("error disabling all events\n");
1098 late_initcall(event_trace_self_tests);