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);
33 trace_get_fields(struct ftrace_event_call *event_call)
35 if (!event_call->class->get_fields)
36 return &event_call->class->fields;
37 return event_call->class->get_fields(event_call);
40 int trace_define_field(struct ftrace_event_call *call, const char *type,
41 const char *name, int offset, int size, int is_signed,
44 struct ftrace_event_field *field;
45 struct list_head *head;
47 if (WARN_ON(!call->class))
50 field = kzalloc(sizeof(*field), GFP_KERNEL);
54 field->name = kstrdup(name, GFP_KERNEL);
58 field->type = kstrdup(type, GFP_KERNEL);
62 if (filter_type == FILTER_OTHER)
63 field->filter_type = filter_assign_type(type);
65 field->filter_type = filter_type;
67 field->offset = offset;
69 field->is_signed = is_signed;
71 head = trace_get_fields(call);
72 list_add(&field->link, head);
83 EXPORT_SYMBOL_GPL(trace_define_field);
85 #define __common_field(type, item) \
86 ret = trace_define_field(call, #type, "common_" #item, \
87 offsetof(typeof(ent), item), \
89 is_signed_type(type), FILTER_OTHER); \
93 static int trace_define_common_fields(struct ftrace_event_call *call)
96 struct trace_entry ent;
98 __common_field(unsigned short, type);
99 __common_field(unsigned char, flags);
100 __common_field(unsigned char, preempt_count);
101 __common_field(int, pid);
102 __common_field(int, lock_depth);
107 void trace_destroy_fields(struct ftrace_event_call *call)
109 struct ftrace_event_field *field, *next;
110 struct list_head *head;
112 head = trace_get_fields(call);
113 list_for_each_entry_safe(field, next, head, link) {
114 list_del(&field->link);
121 int trace_event_raw_init(struct ftrace_event_call *call)
125 id = register_ftrace_event(&call->event);
131 EXPORT_SYMBOL_GPL(trace_event_raw_init);
133 static int ftrace_event_enable_disable(struct ftrace_event_call *call,
140 if (call->flags & TRACE_EVENT_FL_ENABLED) {
141 call->flags &= ~TRACE_EVENT_FL_ENABLED;
142 tracing_stop_cmdline_record();
143 if (call->class->reg)
144 call->class->reg(call, TRACE_REG_UNREGISTER);
146 tracepoint_probe_unregister(call->name,
152 if (!(call->flags & TRACE_EVENT_FL_ENABLED)) {
153 tracing_start_cmdline_record();
154 if (call->class->reg)
155 ret = call->class->reg(call, TRACE_REG_REGISTER);
157 ret = tracepoint_probe_register(call->name,
161 tracing_stop_cmdline_record();
162 pr_info("event trace: Could not enable event "
166 call->flags |= TRACE_EVENT_FL_ENABLED;
174 static void ftrace_clear_events(void)
176 struct ftrace_event_call *call;
178 mutex_lock(&event_mutex);
179 list_for_each_entry(call, &ftrace_events, list) {
180 ftrace_event_enable_disable(call, 0);
182 mutex_unlock(&event_mutex);
186 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
188 static int __ftrace_set_clr_event(const char *match, const char *sub,
189 const char *event, int set)
191 struct ftrace_event_call *call;
194 mutex_lock(&event_mutex);
195 list_for_each_entry(call, &ftrace_events, list) {
197 if (!call->name || !call->class ||
198 (!call->class->probe && !call->class->reg))
202 strcmp(match, call->name) != 0 &&
203 strcmp(match, call->class->system) != 0)
206 if (sub && strcmp(sub, call->class->system) != 0)
209 if (event && strcmp(event, call->name) != 0)
212 ftrace_event_enable_disable(call, set);
216 mutex_unlock(&event_mutex);
221 static int ftrace_set_clr_event(char *buf, int set)
223 char *event = NULL, *sub = NULL, *match;
226 * The buf format can be <subsystem>:<event-name>
227 * *:<event-name> means any event by that name.
228 * :<event-name> is the same.
230 * <subsystem>:* means all events in that subsystem
231 * <subsystem>: means the same.
233 * <name> (no ':') means all events in a subsystem with
234 * the name <name> or any event that matches <name>
237 match = strsep(&buf, ":");
243 if (!strlen(sub) || strcmp(sub, "*") == 0)
245 if (!strlen(event) || strcmp(event, "*") == 0)
249 return __ftrace_set_clr_event(match, sub, event, set);
253 * trace_set_clr_event - enable or disable an event
254 * @system: system name to match (NULL for any system)
255 * @event: event name to match (NULL for all events, within system)
256 * @set: 1 to enable, 0 to disable
258 * This is a way for other parts of the kernel to enable or disable
261 * Returns 0 on success, -EINVAL if the parameters do not match any
264 int trace_set_clr_event(const char *system, const char *event, int set)
266 return __ftrace_set_clr_event(NULL, system, event, set);
269 /* 128 should be much more than enough */
270 #define EVENT_BUF_SIZE 127
273 ftrace_event_write(struct file *file, const char __user *ubuf,
274 size_t cnt, loff_t *ppos)
276 struct trace_parser parser;
282 ret = tracing_update_buffers();
286 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
289 read = trace_get_user(&parser, ubuf, cnt, ppos);
291 if (read >= 0 && trace_parser_loaded((&parser))) {
294 if (*parser.buffer == '!')
297 parser.buffer[parser.idx] = 0;
299 ret = ftrace_set_clr_event(parser.buffer + !set, set);
307 trace_parser_put(&parser);
313 t_next(struct seq_file *m, void *v, loff_t *pos)
315 struct ftrace_event_call *call = v;
319 list_for_each_entry_continue(call, &ftrace_events, list) {
321 * The ftrace subsystem is for showing formats only.
322 * They can not be enabled or disabled via the event files.
324 if (call->class && (call->class->probe || call->class->reg))
331 static void *t_start(struct seq_file *m, loff_t *pos)
333 struct ftrace_event_call *call;
336 mutex_lock(&event_mutex);
338 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
339 for (l = 0; l <= *pos; ) {
340 call = t_next(m, call, &l);
348 s_next(struct seq_file *m, void *v, loff_t *pos)
350 struct ftrace_event_call *call = v;
354 list_for_each_entry_continue(call, &ftrace_events, list) {
355 if (call->flags & TRACE_EVENT_FL_ENABLED)
362 static void *s_start(struct seq_file *m, loff_t *pos)
364 struct ftrace_event_call *call;
367 mutex_lock(&event_mutex);
369 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
370 for (l = 0; l <= *pos; ) {
371 call = s_next(m, call, &l);
378 static int t_show(struct seq_file *m, void *v)
380 struct ftrace_event_call *call = v;
382 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
383 seq_printf(m, "%s:", call->class->system);
384 seq_printf(m, "%s\n", call->name);
389 static void t_stop(struct seq_file *m, void *p)
391 mutex_unlock(&event_mutex);
395 ftrace_event_seq_open(struct inode *inode, struct file *file)
397 const struct seq_operations *seq_ops;
399 if ((file->f_mode & FMODE_WRITE) &&
400 (file->f_flags & O_TRUNC))
401 ftrace_clear_events();
403 seq_ops = inode->i_private;
404 return seq_open(file, seq_ops);
408 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
411 struct ftrace_event_call *call = filp->private_data;
414 if (call->flags & TRACE_EVENT_FL_ENABLED)
419 return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
423 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
426 struct ftrace_event_call *call = filp->private_data;
431 if (cnt >= sizeof(buf))
434 if (copy_from_user(&buf, ubuf, cnt))
439 ret = strict_strtoul(buf, 10, &val);
443 ret = tracing_update_buffers();
450 mutex_lock(&event_mutex);
451 ret = ftrace_event_enable_disable(call, val);
452 mutex_unlock(&event_mutex);
461 return ret ? ret : cnt;
465 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
468 const char set_to_char[4] = { '?', '0', '1', 'X' };
469 const char *system = filp->private_data;
470 struct ftrace_event_call *call;
475 mutex_lock(&event_mutex);
476 list_for_each_entry(call, &ftrace_events, list) {
477 if (!call->name || !call->class ||
478 (!call->class->probe && !call->class->reg))
481 if (system && strcmp(call->class->system, system) != 0)
485 * We need to find out if all the events are set
486 * or if all events or cleared, or if we have
489 set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED));
492 * If we have a mixture, no need to look further.
497 mutex_unlock(&event_mutex);
499 buf[0] = set_to_char[set];
502 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
508 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
511 const char *system = filp->private_data;
516 if (cnt >= sizeof(buf))
519 if (copy_from_user(&buf, ubuf, cnt))
524 ret = strict_strtoul(buf, 10, &val);
528 ret = tracing_update_buffers();
532 if (val != 0 && val != 1)
535 ret = __ftrace_set_clr_event(NULL, system, NULL, val);
548 event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
551 struct ftrace_event_call *call = filp->private_data;
552 struct ftrace_event_field *field;
553 struct list_head *head;
555 int common_field_count = 5;
562 s = kmalloc(sizeof(*s), GFP_KERNEL);
568 trace_seq_printf(s, "name: %s\n", call->name);
569 trace_seq_printf(s, "ID: %d\n", call->event.type);
570 trace_seq_printf(s, "format:\n");
572 head = trace_get_fields(call);
573 list_for_each_entry_reverse(field, head, link) {
575 * Smartly shows the array type(except dynamic array).
578 * If TYPE := TYPE[LEN], it is shown:
579 * field:TYPE VAR[LEN]
581 const char *array_descriptor = strchr(field->type, '[');
583 if (!strncmp(field->type, "__data_loc", 10))
584 array_descriptor = NULL;
586 if (!array_descriptor) {
587 r = trace_seq_printf(s, "\tfield:%s %s;\toffset:%u;"
588 "\tsize:%u;\tsigned:%d;\n",
589 field->type, field->name, field->offset,
590 field->size, !!field->is_signed);
592 r = trace_seq_printf(s, "\tfield:%.*s %s%s;\toffset:%u;"
593 "\tsize:%u;\tsigned:%d;\n",
594 (int)(array_descriptor - field->type),
595 field->type, field->name,
596 array_descriptor, field->offset,
597 field->size, !!field->is_signed);
600 if (--common_field_count == 0)
601 r = trace_seq_printf(s, "\n");
608 r = trace_seq_printf(s, "\nprint fmt: %s\n",
613 * ug! The format output is bigger than a PAGE!!
615 buf = "FORMAT TOO BIG\n";
616 r = simple_read_from_buffer(ubuf, cnt, ppos,
621 r = simple_read_from_buffer(ubuf, cnt, ppos,
629 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
631 struct ftrace_event_call *call = filp->private_data;
638 s = kmalloc(sizeof(*s), GFP_KERNEL);
643 trace_seq_printf(s, "%d\n", call->event.type);
645 r = simple_read_from_buffer(ubuf, cnt, ppos,
652 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
655 struct ftrace_event_call *call = filp->private_data;
662 s = kmalloc(sizeof(*s), GFP_KERNEL);
668 print_event_filter(call, s);
669 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
677 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
680 struct ftrace_event_call *call = filp->private_data;
684 if (cnt >= PAGE_SIZE)
687 buf = (char *)__get_free_page(GFP_TEMPORARY);
691 if (copy_from_user(buf, ubuf, cnt)) {
692 free_page((unsigned long) buf);
697 err = apply_event_filter(call, buf);
698 free_page((unsigned long) buf);
708 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
711 struct event_subsystem *system = filp->private_data;
718 s = kmalloc(sizeof(*s), GFP_KERNEL);
724 print_subsystem_event_filter(system, s);
725 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
733 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
736 struct event_subsystem *system = filp->private_data;
740 if (cnt >= PAGE_SIZE)
743 buf = (char *)__get_free_page(GFP_TEMPORARY);
747 if (copy_from_user(buf, ubuf, cnt)) {
748 free_page((unsigned long) buf);
753 err = apply_subsystem_event_filter(system, buf);
754 free_page((unsigned long) buf);
764 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
766 int (*func)(struct trace_seq *s) = filp->private_data;
773 s = kmalloc(sizeof(*s), GFP_KERNEL);
780 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
787 static const struct seq_operations show_event_seq_ops = {
794 static const struct seq_operations show_set_event_seq_ops = {
801 static const struct file_operations ftrace_avail_fops = {
802 .open = ftrace_event_seq_open,
805 .release = seq_release,
808 static const struct file_operations ftrace_set_event_fops = {
809 .open = ftrace_event_seq_open,
811 .write = ftrace_event_write,
813 .release = seq_release,
816 static const struct file_operations ftrace_enable_fops = {
817 .open = tracing_open_generic,
818 .read = event_enable_read,
819 .write = event_enable_write,
822 static const struct file_operations ftrace_event_format_fops = {
823 .open = tracing_open_generic,
824 .read = event_format_read,
827 static const struct file_operations ftrace_event_id_fops = {
828 .open = tracing_open_generic,
829 .read = event_id_read,
832 static const struct file_operations ftrace_event_filter_fops = {
833 .open = tracing_open_generic,
834 .read = event_filter_read,
835 .write = event_filter_write,
838 static const struct file_operations ftrace_subsystem_filter_fops = {
839 .open = tracing_open_generic,
840 .read = subsystem_filter_read,
841 .write = subsystem_filter_write,
844 static const struct file_operations ftrace_system_enable_fops = {
845 .open = tracing_open_generic,
846 .read = system_enable_read,
847 .write = system_enable_write,
850 static const struct file_operations ftrace_show_header_fops = {
851 .open = tracing_open_generic,
855 static struct dentry *event_trace_events_dir(void)
857 static struct dentry *d_tracer;
858 static struct dentry *d_events;
863 d_tracer = tracing_init_dentry();
867 d_events = debugfs_create_dir("events", d_tracer);
869 pr_warning("Could not create debugfs "
870 "'events' directory\n");
875 static LIST_HEAD(event_subsystems);
877 static struct dentry *
878 event_subsystem_dir(const char *name, struct dentry *d_events)
880 struct event_subsystem *system;
881 struct dentry *entry;
883 /* First see if we did not already create this dir */
884 list_for_each_entry(system, &event_subsystems, list) {
885 if (strcmp(system->name, name) == 0) {
887 return system->entry;
891 /* need to create new entry */
892 system = kmalloc(sizeof(*system), GFP_KERNEL);
894 pr_warning("No memory to create event subsystem %s\n",
899 system->entry = debugfs_create_dir(name, d_events);
900 if (!system->entry) {
901 pr_warning("Could not create event subsystem %s\n",
907 system->nr_events = 1;
908 system->name = kstrdup(name, GFP_KERNEL);
910 debugfs_remove(system->entry);
915 list_add(&system->list, &event_subsystems);
917 system->filter = NULL;
919 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
920 if (!system->filter) {
921 pr_warning("Could not allocate filter for subsystem "
923 return system->entry;
926 entry = debugfs_create_file("filter", 0644, system->entry, system,
927 &ftrace_subsystem_filter_fops);
929 kfree(system->filter);
930 system->filter = NULL;
931 pr_warning("Could not create debugfs "
932 "'%s/filter' entry\n", name);
935 trace_create_file("enable", 0644, system->entry,
936 (void *)system->name,
937 &ftrace_system_enable_fops);
939 return system->entry;
943 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
944 const struct file_operations *id,
945 const struct file_operations *enable,
946 const struct file_operations *filter,
947 const struct file_operations *format)
949 struct list_head *head;
953 * If the trace point header did not define TRACE_SYSTEM
954 * then the system would be called "TRACE_SYSTEM".
956 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
957 d_events = event_subsystem_dir(call->class->system, d_events);
959 call->dir = debugfs_create_dir(call->name, d_events);
961 pr_warning("Could not create debugfs "
962 "'%s' directory\n", call->name);
966 if (call->class->probe || call->class->reg)
967 trace_create_file("enable", 0644, call->dir, call,
970 #ifdef CONFIG_PERF_EVENTS
971 if (call->event.type && (call->class->perf_probe || call->class->reg))
972 trace_create_file("id", 0444, call->dir, call,
976 if (call->class->define_fields) {
978 * Other events may have the same class. Only update
979 * the fields if they are not already defined.
981 head = trace_get_fields(call);
982 if (list_empty(head)) {
983 ret = trace_define_common_fields(call);
985 ret = call->class->define_fields(call);
987 pr_warning("Could not initialize trace point"
988 " events/%s\n", call->name);
992 trace_create_file("filter", 0644, call->dir, call,
996 trace_create_file("format", 0444, call->dir, call,
1002 static int __trace_add_event_call(struct ftrace_event_call *call)
1004 struct dentry *d_events;
1010 if (call->class->raw_init) {
1011 ret = call->class->raw_init(call);
1014 pr_warning("Could not initialize trace "
1015 "events/%s\n", call->name);
1020 d_events = event_trace_events_dir();
1024 ret = event_create_dir(call, d_events, &ftrace_event_id_fops,
1025 &ftrace_enable_fops, &ftrace_event_filter_fops,
1026 &ftrace_event_format_fops);
1028 list_add(&call->list, &ftrace_events);
1033 /* Add an additional event_call dynamically */
1034 int trace_add_event_call(struct ftrace_event_call *call)
1037 mutex_lock(&event_mutex);
1038 ret = __trace_add_event_call(call);
1039 mutex_unlock(&event_mutex);
1043 static void remove_subsystem_dir(const char *name)
1045 struct event_subsystem *system;
1047 if (strcmp(name, TRACE_SYSTEM) == 0)
1050 list_for_each_entry(system, &event_subsystems, list) {
1051 if (strcmp(system->name, name) == 0) {
1052 if (!--system->nr_events) {
1053 struct event_filter *filter = system->filter;
1055 debugfs_remove_recursive(system->entry);
1056 list_del(&system->list);
1058 kfree(filter->filter_string);
1061 kfree(system->name);
1070 * Must be called under locking both of event_mutex and trace_event_mutex.
1072 static void __trace_remove_event_call(struct ftrace_event_call *call)
1074 ftrace_event_enable_disable(call, 0);
1075 if (call->event.funcs)
1076 __unregister_ftrace_event(&call->event);
1077 debugfs_remove_recursive(call->dir);
1078 list_del(&call->list);
1079 trace_destroy_fields(call);
1080 destroy_preds(call);
1081 remove_subsystem_dir(call->class->system);
1084 /* Remove an event_call */
1085 void trace_remove_event_call(struct ftrace_event_call *call)
1087 mutex_lock(&event_mutex);
1088 down_write(&trace_event_mutex);
1089 __trace_remove_event_call(call);
1090 up_write(&trace_event_mutex);
1091 mutex_unlock(&event_mutex);
1094 #define for_each_event(event, start, end) \
1095 for (event = start; \
1096 (unsigned long)event < (unsigned long)end; \
1099 #ifdef CONFIG_MODULES
1101 static LIST_HEAD(ftrace_module_file_list);
1104 * Modules must own their file_operations to keep up with
1105 * reference counting.
1107 struct ftrace_module_file_ops {
1108 struct list_head list;
1110 struct file_operations id;
1111 struct file_operations enable;
1112 struct file_operations format;
1113 struct file_operations filter;
1116 static struct ftrace_module_file_ops *
1117 trace_create_file_ops(struct module *mod)
1119 struct ftrace_module_file_ops *file_ops;
1122 * This is a bit of a PITA. To allow for correct reference
1123 * counting, modules must "own" their file_operations.
1124 * To do this, we allocate the file operations that will be
1125 * used in the event directory.
1128 file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1132 file_ops->mod = mod;
1134 file_ops->id = ftrace_event_id_fops;
1135 file_ops->id.owner = mod;
1137 file_ops->enable = ftrace_enable_fops;
1138 file_ops->enable.owner = mod;
1140 file_ops->filter = ftrace_event_filter_fops;
1141 file_ops->filter.owner = mod;
1143 file_ops->format = ftrace_event_format_fops;
1144 file_ops->format.owner = mod;
1146 list_add(&file_ops->list, &ftrace_module_file_list);
1151 static void trace_module_add_events(struct module *mod)
1153 struct ftrace_module_file_ops *file_ops = NULL;
1154 struct ftrace_event_call *call, *start, *end;
1155 struct dentry *d_events;
1158 start = mod->trace_events;
1159 end = mod->trace_events + mod->num_trace_events;
1164 d_events = event_trace_events_dir();
1168 for_each_event(call, start, end) {
1169 /* The linker may leave blanks */
1172 if (call->class->raw_init) {
1173 ret = call->class->raw_init(call);
1176 pr_warning("Could not initialize trace "
1177 "point events/%s\n", call->name);
1182 * This module has events, create file ops for this module
1183 * if not already done.
1186 file_ops = trace_create_file_ops(mod);
1191 ret = event_create_dir(call, d_events,
1192 &file_ops->id, &file_ops->enable,
1193 &file_ops->filter, &file_ops->format);
1195 list_add(&call->list, &ftrace_events);
1199 static void trace_module_remove_events(struct module *mod)
1201 struct ftrace_module_file_ops *file_ops;
1202 struct ftrace_event_call *call, *p;
1205 down_write(&trace_event_mutex);
1206 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1207 if (call->mod == mod) {
1209 __trace_remove_event_call(call);
1213 /* Now free the file_operations */
1214 list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1215 if (file_ops->mod == mod)
1218 if (&file_ops->list != &ftrace_module_file_list) {
1219 list_del(&file_ops->list);
1224 * It is safest to reset the ring buffer if the module being unloaded
1225 * registered any events.
1228 tracing_reset_current_online_cpus();
1229 up_write(&trace_event_mutex);
1232 static int trace_module_notify(struct notifier_block *self,
1233 unsigned long val, void *data)
1235 struct module *mod = data;
1237 mutex_lock(&event_mutex);
1239 case MODULE_STATE_COMING:
1240 trace_module_add_events(mod);
1242 case MODULE_STATE_GOING:
1243 trace_module_remove_events(mod);
1246 mutex_unlock(&event_mutex);
1251 static int trace_module_notify(struct notifier_block *self,
1252 unsigned long val, void *data)
1256 #endif /* CONFIG_MODULES */
1258 static struct notifier_block trace_module_nb = {
1259 .notifier_call = trace_module_notify,
1263 extern struct ftrace_event_call __start_ftrace_events[];
1264 extern struct ftrace_event_call __stop_ftrace_events[];
1266 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1268 static __init int setup_trace_event(char *str)
1270 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1271 ring_buffer_expanded = 1;
1272 tracing_selftest_disabled = 1;
1276 __setup("trace_event=", setup_trace_event);
1278 static __init int event_trace_init(void)
1280 struct ftrace_event_call *call;
1281 struct dentry *d_tracer;
1282 struct dentry *entry;
1283 struct dentry *d_events;
1285 char *buf = bootup_event_buf;
1288 d_tracer = tracing_init_dentry();
1292 entry = debugfs_create_file("available_events", 0444, d_tracer,
1293 (void *)&show_event_seq_ops,
1294 &ftrace_avail_fops);
1296 pr_warning("Could not create debugfs "
1297 "'available_events' entry\n");
1299 entry = debugfs_create_file("set_event", 0644, d_tracer,
1300 (void *)&show_set_event_seq_ops,
1301 &ftrace_set_event_fops);
1303 pr_warning("Could not create debugfs "
1304 "'set_event' entry\n");
1306 d_events = event_trace_events_dir();
1310 /* ring buffer internal formats */
1311 trace_create_file("header_page", 0444, d_events,
1312 ring_buffer_print_page_header,
1313 &ftrace_show_header_fops);
1315 trace_create_file("header_event", 0444, d_events,
1316 ring_buffer_print_entry_header,
1317 &ftrace_show_header_fops);
1319 trace_create_file("enable", 0644, d_events,
1320 NULL, &ftrace_system_enable_fops);
1322 for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
1323 /* The linker may leave blanks */
1326 if (call->class->raw_init) {
1327 ret = call->class->raw_init(call);
1330 pr_warning("Could not initialize trace "
1331 "point events/%s\n", call->name);
1335 ret = event_create_dir(call, d_events, &ftrace_event_id_fops,
1336 &ftrace_enable_fops,
1337 &ftrace_event_filter_fops,
1338 &ftrace_event_format_fops);
1340 list_add(&call->list, &ftrace_events);
1344 token = strsep(&buf, ",");
1351 ret = ftrace_set_clr_event(token, 1);
1353 pr_warning("Failed to enable trace event: %s\n", token);
1356 ret = register_module_notifier(&trace_module_nb);
1358 pr_warning("Failed to register trace events module notifier\n");
1362 fs_initcall(event_trace_init);
1364 #ifdef CONFIG_FTRACE_STARTUP_TEST
1366 static DEFINE_SPINLOCK(test_spinlock);
1367 static DEFINE_SPINLOCK(test_spinlock_irq);
1368 static DEFINE_MUTEX(test_mutex);
1370 static __init void test_work(struct work_struct *dummy)
1372 spin_lock(&test_spinlock);
1373 spin_lock_irq(&test_spinlock_irq);
1375 spin_unlock_irq(&test_spinlock_irq);
1376 spin_unlock(&test_spinlock);
1378 mutex_lock(&test_mutex);
1380 mutex_unlock(&test_mutex);
1383 static __init int event_test_thread(void *unused)
1387 test_malloc = kmalloc(1234, GFP_KERNEL);
1389 pr_info("failed to kmalloc\n");
1391 schedule_on_each_cpu(test_work);
1395 set_current_state(TASK_INTERRUPTIBLE);
1396 while (!kthread_should_stop())
1403 * Do various things that may trigger events.
1405 static __init void event_test_stuff(void)
1407 struct task_struct *test_thread;
1409 test_thread = kthread_run(event_test_thread, NULL, "test-events");
1411 kthread_stop(test_thread);
1415 * For every trace event defined, we will test each trace point separately,
1416 * and then by groups, and finally all trace points.
1418 static __init void event_trace_self_tests(void)
1420 struct ftrace_event_call *call;
1421 struct event_subsystem *system;
1424 pr_info("Running tests on trace events:\n");
1426 list_for_each_entry(call, &ftrace_events, list) {
1428 /* Only test those that have a probe */
1429 if (!call->class || !call->class->probe)
1433 * Testing syscall events here is pretty useless, but
1434 * we still do it if configured. But this is time consuming.
1435 * What we really need is a user thread to perform the
1436 * syscalls as we test.
1438 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1439 if (call->class->system &&
1440 strcmp(call->class->system, "syscalls") == 0)
1444 pr_info("Testing event %s: ", call->name);
1447 * If an event is already enabled, someone is using
1448 * it and the self test should not be on.
1450 if (call->flags & TRACE_EVENT_FL_ENABLED) {
1451 pr_warning("Enabled event during self test!\n");
1456 ftrace_event_enable_disable(call, 1);
1458 ftrace_event_enable_disable(call, 0);
1463 /* Now test at the sub system level */
1465 pr_info("Running tests on trace event systems:\n");
1467 list_for_each_entry(system, &event_subsystems, list) {
1469 /* the ftrace system is special, skip it */
1470 if (strcmp(system->name, "ftrace") == 0)
1473 pr_info("Testing event system %s: ", system->name);
1475 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1476 if (WARN_ON_ONCE(ret)) {
1477 pr_warning("error enabling system %s\n",
1484 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1485 if (WARN_ON_ONCE(ret))
1486 pr_warning("error disabling system %s\n",
1492 /* Test with all events enabled */
1494 pr_info("Running tests on all trace events:\n");
1495 pr_info("Testing all events: ");
1497 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1498 if (WARN_ON_ONCE(ret)) {
1499 pr_warning("error enabling all events\n");
1506 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1507 if (WARN_ON_ONCE(ret)) {
1508 pr_warning("error disabling all events\n");
1515 #ifdef CONFIG_FUNCTION_TRACER
1517 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1520 function_test_events_call(unsigned long ip, unsigned long parent_ip)
1522 struct ring_buffer_event *event;
1523 struct ring_buffer *buffer;
1524 struct ftrace_entry *entry;
1525 unsigned long flags;
1531 pc = preempt_count();
1532 resched = ftrace_preempt_disable();
1533 cpu = raw_smp_processor_id();
1534 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1539 local_save_flags(flags);
1541 event = trace_current_buffer_lock_reserve(&buffer,
1542 TRACE_FN, sizeof(*entry),
1546 entry = ring_buffer_event_data(event);
1548 entry->parent_ip = parent_ip;
1550 trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
1553 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1554 ftrace_preempt_enable(resched);
1557 static struct ftrace_ops trace_ops __initdata =
1559 .func = function_test_events_call,
1562 static __init void event_trace_self_test_with_function(void)
1564 register_ftrace_function(&trace_ops);
1565 pr_info("Running tests again, along with the function tracer\n");
1566 event_trace_self_tests();
1567 unregister_ftrace_function(&trace_ops);
1570 static __init void event_trace_self_test_with_function(void)
1575 static __init int event_trace_self_tests_init(void)
1577 if (!tracing_selftest_disabled) {
1578 event_trace_self_tests();
1579 event_trace_self_test_with_function();
1585 late_initcall(event_trace_self_tests_init);