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 LIST_HEAD(ftrace_common_fields);
34 trace_get_fields(struct ftrace_event_call *event_call)
36 if (!event_call->class->get_fields)
37 return &event_call->class->fields;
38 return event_call->class->get_fields(event_call);
41 static int __trace_define_field(struct list_head *head, const char *type,
42 const char *name, int offset, int size,
43 int is_signed, int filter_type)
45 struct ftrace_event_field *field;
47 field = kzalloc(sizeof(*field), GFP_KERNEL);
51 field->name = kstrdup(name, GFP_KERNEL);
55 field->type = kstrdup(type, GFP_KERNEL);
59 if (filter_type == FILTER_OTHER)
60 field->filter_type = filter_assign_type(type);
62 field->filter_type = filter_type;
64 field->offset = offset;
66 field->is_signed = is_signed;
68 list_add(&field->link, head);
80 int trace_define_field(struct ftrace_event_call *call, const char *type,
81 const char *name, int offset, int size, int is_signed,
84 struct list_head *head;
86 if (WARN_ON(!call->class))
89 head = trace_get_fields(call);
90 return __trace_define_field(head, type, name, offset, size,
91 is_signed, filter_type);
93 EXPORT_SYMBOL_GPL(trace_define_field);
95 #define __common_field(type, item) \
96 ret = __trace_define_field(&ftrace_common_fields, #type, \
98 offsetof(typeof(ent), item), \
100 is_signed_type(type), FILTER_OTHER); \
104 static int trace_define_common_fields(void)
107 struct trace_entry ent;
109 __common_field(unsigned short, type);
110 __common_field(unsigned char, flags);
111 __common_field(unsigned char, preempt_count);
112 __common_field(int, pid);
113 __common_field(int, lock_depth);
118 void trace_destroy_fields(struct ftrace_event_call *call)
120 struct ftrace_event_field *field, *next;
121 struct list_head *head;
123 head = trace_get_fields(call);
124 list_for_each_entry_safe(field, next, head, link) {
125 list_del(&field->link);
132 int trace_event_raw_init(struct ftrace_event_call *call)
136 id = register_ftrace_event(&call->event);
142 EXPORT_SYMBOL_GPL(trace_event_raw_init);
144 int ftrace_event_reg(struct ftrace_event_call *call, enum trace_reg type)
147 case TRACE_REG_REGISTER:
148 return tracepoint_probe_register(call->name,
151 case TRACE_REG_UNREGISTER:
152 tracepoint_probe_unregister(call->name,
157 #ifdef CONFIG_PERF_EVENTS
158 case TRACE_REG_PERF_REGISTER:
159 return tracepoint_probe_register(call->name,
160 call->class->perf_probe,
162 case TRACE_REG_PERF_UNREGISTER:
163 tracepoint_probe_unregister(call->name,
164 call->class->perf_probe,
171 EXPORT_SYMBOL_GPL(ftrace_event_reg);
173 void trace_event_enable_cmd_record(bool enable)
175 struct ftrace_event_call *call;
177 mutex_lock(&event_mutex);
178 list_for_each_entry(call, &ftrace_events, list) {
179 if (!(call->flags & TRACE_EVENT_FL_ENABLED))
183 tracing_start_cmdline_record();
184 call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
186 tracing_stop_cmdline_record();
187 call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
190 mutex_unlock(&event_mutex);
193 static int ftrace_event_enable_disable(struct ftrace_event_call *call,
200 if (call->flags & TRACE_EVENT_FL_ENABLED) {
201 call->flags &= ~TRACE_EVENT_FL_ENABLED;
202 if (call->flags & TRACE_EVENT_FL_RECORDED_CMD) {
203 tracing_stop_cmdline_record();
204 call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
206 call->class->reg(call, TRACE_REG_UNREGISTER);
210 if (!(call->flags & TRACE_EVENT_FL_ENABLED)) {
211 if (trace_flags & TRACE_ITER_RECORD_CMD) {
212 tracing_start_cmdline_record();
213 call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
215 ret = call->class->reg(call, TRACE_REG_REGISTER);
217 tracing_stop_cmdline_record();
218 pr_info("event trace: Could not enable event "
222 call->flags |= TRACE_EVENT_FL_ENABLED;
230 static void ftrace_clear_events(void)
232 struct ftrace_event_call *call;
234 mutex_lock(&event_mutex);
235 list_for_each_entry(call, &ftrace_events, list) {
236 ftrace_event_enable_disable(call, 0);
238 mutex_unlock(&event_mutex);
242 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
244 static int __ftrace_set_clr_event(const char *match, const char *sub,
245 const char *event, int set)
247 struct ftrace_event_call *call;
250 mutex_lock(&event_mutex);
251 list_for_each_entry(call, &ftrace_events, list) {
253 if (!call->name || !call->class || !call->class->reg)
257 strcmp(match, call->name) != 0 &&
258 strcmp(match, call->class->system) != 0)
261 if (sub && strcmp(sub, call->class->system) != 0)
264 if (event && strcmp(event, call->name) != 0)
267 ftrace_event_enable_disable(call, set);
271 mutex_unlock(&event_mutex);
276 static int ftrace_set_clr_event(char *buf, int set)
278 char *event = NULL, *sub = NULL, *match;
281 * The buf format can be <subsystem>:<event-name>
282 * *:<event-name> means any event by that name.
283 * :<event-name> is the same.
285 * <subsystem>:* means all events in that subsystem
286 * <subsystem>: means the same.
288 * <name> (no ':') means all events in a subsystem with
289 * the name <name> or any event that matches <name>
292 match = strsep(&buf, ":");
298 if (!strlen(sub) || strcmp(sub, "*") == 0)
300 if (!strlen(event) || strcmp(event, "*") == 0)
304 return __ftrace_set_clr_event(match, sub, event, set);
308 * trace_set_clr_event - enable or disable an event
309 * @system: system name to match (NULL for any system)
310 * @event: event name to match (NULL for all events, within system)
311 * @set: 1 to enable, 0 to disable
313 * This is a way for other parts of the kernel to enable or disable
316 * Returns 0 on success, -EINVAL if the parameters do not match any
319 int trace_set_clr_event(const char *system, const char *event, int set)
321 return __ftrace_set_clr_event(NULL, system, event, set);
324 /* 128 should be much more than enough */
325 #define EVENT_BUF_SIZE 127
328 ftrace_event_write(struct file *file, const char __user *ubuf,
329 size_t cnt, loff_t *ppos)
331 struct trace_parser parser;
337 ret = tracing_update_buffers();
341 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
344 read = trace_get_user(&parser, ubuf, cnt, ppos);
346 if (read >= 0 && trace_parser_loaded((&parser))) {
349 if (*parser.buffer == '!')
352 parser.buffer[parser.idx] = 0;
354 ret = ftrace_set_clr_event(parser.buffer + !set, set);
362 trace_parser_put(&parser);
368 t_next(struct seq_file *m, void *v, loff_t *pos)
370 struct ftrace_event_call *call = v;
374 list_for_each_entry_continue(call, &ftrace_events, list) {
376 * The ftrace subsystem is for showing formats only.
377 * They can not be enabled or disabled via the event files.
379 if (call->class && call->class->reg)
386 static void *t_start(struct seq_file *m, loff_t *pos)
388 struct ftrace_event_call *call;
391 mutex_lock(&event_mutex);
393 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
394 for (l = 0; l <= *pos; ) {
395 call = t_next(m, call, &l);
403 s_next(struct seq_file *m, void *v, loff_t *pos)
405 struct ftrace_event_call *call = v;
409 list_for_each_entry_continue(call, &ftrace_events, list) {
410 if (call->flags & TRACE_EVENT_FL_ENABLED)
417 static void *s_start(struct seq_file *m, loff_t *pos)
419 struct ftrace_event_call *call;
422 mutex_lock(&event_mutex);
424 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
425 for (l = 0; l <= *pos; ) {
426 call = s_next(m, call, &l);
433 static int t_show(struct seq_file *m, void *v)
435 struct ftrace_event_call *call = v;
437 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
438 seq_printf(m, "%s:", call->class->system);
439 seq_printf(m, "%s\n", call->name);
444 static void t_stop(struct seq_file *m, void *p)
446 mutex_unlock(&event_mutex);
450 ftrace_event_seq_open(struct inode *inode, struct file *file)
452 const struct seq_operations *seq_ops;
454 if ((file->f_mode & FMODE_WRITE) &&
455 (file->f_flags & O_TRUNC))
456 ftrace_clear_events();
458 seq_ops = inode->i_private;
459 return seq_open(file, seq_ops);
463 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
466 struct ftrace_event_call *call = filp->private_data;
469 if (call->flags & TRACE_EVENT_FL_ENABLED)
474 return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
478 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
481 struct ftrace_event_call *call = filp->private_data;
486 if (cnt >= sizeof(buf))
489 if (copy_from_user(&buf, ubuf, cnt))
494 ret = strict_strtoul(buf, 10, &val);
498 ret = tracing_update_buffers();
505 mutex_lock(&event_mutex);
506 ret = ftrace_event_enable_disable(call, val);
507 mutex_unlock(&event_mutex);
516 return ret ? ret : cnt;
520 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
523 const char set_to_char[4] = { '?', '0', '1', 'X' };
524 const char *system = filp->private_data;
525 struct ftrace_event_call *call;
530 mutex_lock(&event_mutex);
531 list_for_each_entry(call, &ftrace_events, list) {
532 if (!call->name || !call->class || !call->class->reg)
535 if (system && strcmp(call->class->system, system) != 0)
539 * We need to find out if all the events are set
540 * or if all events or cleared, or if we have
543 set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED));
546 * If we have a mixture, no need to look further.
551 mutex_unlock(&event_mutex);
553 buf[0] = set_to_char[set];
556 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
562 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
565 const char *system = filp->private_data;
570 if (cnt >= sizeof(buf))
573 if (copy_from_user(&buf, ubuf, cnt))
578 ret = strict_strtoul(buf, 10, &val);
582 ret = tracing_update_buffers();
586 if (val != 0 && val != 1)
589 ret = __ftrace_set_clr_event(NULL, system, NULL, val);
606 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
608 struct ftrace_event_call *call = m->private;
609 struct ftrace_event_field *field;
610 struct list_head *head;
614 switch ((unsigned long)v) {
616 head = &ftrace_common_fields;
618 if (unlikely(list_empty(head)))
621 field = list_entry(head->prev, struct ftrace_event_field, link);
624 case FORMAT_PRINTFMT:
629 head = trace_get_fields(call);
632 * To separate common fields from event fields, the
633 * LSB is set on the first event field. Clear it in case.
635 v = (void *)((unsigned long)v & ~1L);
639 * If this is a common field, and at the end of the list, then
640 * continue with main list.
642 if (field->link.prev == &ftrace_common_fields) {
643 if (unlikely(list_empty(head)))
645 field = list_entry(head->prev, struct ftrace_event_field, link);
646 /* Set the LSB to notify f_show to print an extra newline */
647 field = (struct ftrace_event_field *)
648 ((unsigned long)field | 1);
652 /* If we are done tell f_show to print the format */
653 if (field->link.prev == head)
654 return (void *)FORMAT_PRINTFMT;
656 field = list_entry(field->link.prev, struct ftrace_event_field, link);
661 static void *f_start(struct seq_file *m, loff_t *pos)
666 /* Start by showing the header */
668 return (void *)FORMAT_HEADER;
670 p = (void *)FORMAT_HEADER;
672 p = f_next(m, p, &l);
673 } while (p && l < *pos);
678 static int f_show(struct seq_file *m, void *v)
680 struct ftrace_event_call *call = m->private;
681 struct ftrace_event_field *field;
682 const char *array_descriptor;
684 switch ((unsigned long)v) {
686 seq_printf(m, "name: %s\n", call->name);
687 seq_printf(m, "ID: %d\n", call->event.type);
688 seq_printf(m, "format:\n");
691 case FORMAT_PRINTFMT:
692 seq_printf(m, "\nprint fmt: %s\n",
698 * To separate common fields from event fields, the
699 * LSB is set on the first event field. Clear it and
700 * print a newline if it is set.
702 if ((unsigned long)v & 1) {
704 v = (void *)((unsigned long)v & ~1L);
710 * Smartly shows the array type(except dynamic array).
713 * If TYPE := TYPE[LEN], it is shown:
714 * field:TYPE VAR[LEN]
716 array_descriptor = strchr(field->type, '[');
718 if (!strncmp(field->type, "__data_loc", 10))
719 array_descriptor = NULL;
721 if (!array_descriptor)
722 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
723 field->type, field->name, field->offset,
724 field->size, !!field->is_signed);
726 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
727 (int)(array_descriptor - field->type),
728 field->type, field->name,
729 array_descriptor, field->offset,
730 field->size, !!field->is_signed);
735 static void f_stop(struct seq_file *m, void *p)
739 static const struct seq_operations trace_format_seq_ops = {
746 static int trace_format_open(struct inode *inode, struct file *file)
748 struct ftrace_event_call *call = inode->i_private;
752 ret = seq_open(file, &trace_format_seq_ops);
756 m = file->private_data;
763 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
765 struct ftrace_event_call *call = filp->private_data;
772 s = kmalloc(sizeof(*s), GFP_KERNEL);
777 trace_seq_printf(s, "%d\n", call->event.type);
779 r = simple_read_from_buffer(ubuf, cnt, ppos,
786 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
789 struct ftrace_event_call *call = filp->private_data;
796 s = kmalloc(sizeof(*s), GFP_KERNEL);
802 print_event_filter(call, s);
803 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
811 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
814 struct ftrace_event_call *call = filp->private_data;
818 if (cnt >= PAGE_SIZE)
821 buf = (char *)__get_free_page(GFP_TEMPORARY);
825 if (copy_from_user(buf, ubuf, cnt)) {
826 free_page((unsigned long) buf);
831 err = apply_event_filter(call, buf);
832 free_page((unsigned long) buf);
842 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
845 struct event_subsystem *system = filp->private_data;
852 s = kmalloc(sizeof(*s), GFP_KERNEL);
858 print_subsystem_event_filter(system, s);
859 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
867 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
870 struct event_subsystem *system = filp->private_data;
874 if (cnt >= PAGE_SIZE)
877 buf = (char *)__get_free_page(GFP_TEMPORARY);
881 if (copy_from_user(buf, ubuf, cnt)) {
882 free_page((unsigned long) buf);
887 err = apply_subsystem_event_filter(system, buf);
888 free_page((unsigned long) buf);
898 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
900 int (*func)(struct trace_seq *s) = filp->private_data;
907 s = kmalloc(sizeof(*s), GFP_KERNEL);
914 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
921 static const struct seq_operations show_event_seq_ops = {
928 static const struct seq_operations show_set_event_seq_ops = {
935 static const struct file_operations ftrace_avail_fops = {
936 .open = ftrace_event_seq_open,
939 .release = seq_release,
942 static const struct file_operations ftrace_set_event_fops = {
943 .open = ftrace_event_seq_open,
945 .write = ftrace_event_write,
947 .release = seq_release,
950 static const struct file_operations ftrace_enable_fops = {
951 .open = tracing_open_generic,
952 .read = event_enable_read,
953 .write = event_enable_write,
956 static const struct file_operations ftrace_event_format_fops = {
957 .open = trace_format_open,
960 .release = seq_release,
963 static const struct file_operations ftrace_event_id_fops = {
964 .open = tracing_open_generic,
965 .read = event_id_read,
968 static const struct file_operations ftrace_event_filter_fops = {
969 .open = tracing_open_generic,
970 .read = event_filter_read,
971 .write = event_filter_write,
974 static const struct file_operations ftrace_subsystem_filter_fops = {
975 .open = tracing_open_generic,
976 .read = subsystem_filter_read,
977 .write = subsystem_filter_write,
980 static const struct file_operations ftrace_system_enable_fops = {
981 .open = tracing_open_generic,
982 .read = system_enable_read,
983 .write = system_enable_write,
986 static const struct file_operations ftrace_show_header_fops = {
987 .open = tracing_open_generic,
991 static struct dentry *event_trace_events_dir(void)
993 static struct dentry *d_tracer;
994 static struct dentry *d_events;
999 d_tracer = tracing_init_dentry();
1003 d_events = debugfs_create_dir("events", d_tracer);
1005 pr_warning("Could not create debugfs "
1006 "'events' directory\n");
1011 static LIST_HEAD(event_subsystems);
1013 static struct dentry *
1014 event_subsystem_dir(const char *name, struct dentry *d_events)
1016 struct event_subsystem *system;
1017 struct dentry *entry;
1019 /* First see if we did not already create this dir */
1020 list_for_each_entry(system, &event_subsystems, list) {
1021 if (strcmp(system->name, name) == 0) {
1022 system->nr_events++;
1023 return system->entry;
1027 /* need to create new entry */
1028 system = kmalloc(sizeof(*system), GFP_KERNEL);
1030 pr_warning("No memory to create event subsystem %s\n",
1035 system->entry = debugfs_create_dir(name, d_events);
1036 if (!system->entry) {
1037 pr_warning("Could not create event subsystem %s\n",
1043 system->nr_events = 1;
1044 system->name = kstrdup(name, GFP_KERNEL);
1045 if (!system->name) {
1046 debugfs_remove(system->entry);
1051 list_add(&system->list, &event_subsystems);
1053 system->filter = NULL;
1055 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1056 if (!system->filter) {
1057 pr_warning("Could not allocate filter for subsystem "
1059 return system->entry;
1062 entry = debugfs_create_file("filter", 0644, system->entry, system,
1063 &ftrace_subsystem_filter_fops);
1065 kfree(system->filter);
1066 system->filter = NULL;
1067 pr_warning("Could not create debugfs "
1068 "'%s/filter' entry\n", name);
1071 trace_create_file("enable", 0644, system->entry,
1072 (void *)system->name,
1073 &ftrace_system_enable_fops);
1075 return system->entry;
1079 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
1080 const struct file_operations *id,
1081 const struct file_operations *enable,
1082 const struct file_operations *filter,
1083 const struct file_operations *format)
1085 struct list_head *head;
1089 * If the trace point header did not define TRACE_SYSTEM
1090 * then the system would be called "TRACE_SYSTEM".
1092 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1093 d_events = event_subsystem_dir(call->class->system, d_events);
1095 call->dir = debugfs_create_dir(call->name, d_events);
1097 pr_warning("Could not create debugfs "
1098 "'%s' directory\n", call->name);
1102 if (call->class->reg)
1103 trace_create_file("enable", 0644, call->dir, call,
1106 #ifdef CONFIG_PERF_EVENTS
1107 if (call->event.type && call->class->reg)
1108 trace_create_file("id", 0444, call->dir, call,
1113 * Other events may have the same class. Only update
1114 * the fields if they are not already defined.
1116 head = trace_get_fields(call);
1117 if (list_empty(head)) {
1118 ret = call->class->define_fields(call);
1120 pr_warning("Could not initialize trace point"
1121 " events/%s\n", call->name);
1125 trace_create_file("filter", 0644, call->dir, call,
1128 trace_create_file("format", 0444, call->dir, call,
1135 __trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
1136 const struct file_operations *id,
1137 const struct file_operations *enable,
1138 const struct file_operations *filter,
1139 const struct file_operations *format)
1141 struct dentry *d_events;
1144 /* The linker may leave blanks */
1148 if (call->class->raw_init) {
1149 ret = call->class->raw_init(call);
1152 pr_warning("Could not initialize trace events/%s\n",
1158 d_events = event_trace_events_dir();
1162 ret = event_create_dir(call, d_events, id, enable, filter, format);
1164 list_add(&call->list, &ftrace_events);
1170 /* Add an additional event_call dynamically */
1171 int trace_add_event_call(struct ftrace_event_call *call)
1174 mutex_lock(&event_mutex);
1175 ret = __trace_add_event_call(call, NULL, &ftrace_event_id_fops,
1176 &ftrace_enable_fops,
1177 &ftrace_event_filter_fops,
1178 &ftrace_event_format_fops);
1179 mutex_unlock(&event_mutex);
1183 static void remove_subsystem_dir(const char *name)
1185 struct event_subsystem *system;
1187 if (strcmp(name, TRACE_SYSTEM) == 0)
1190 list_for_each_entry(system, &event_subsystems, list) {
1191 if (strcmp(system->name, name) == 0) {
1192 if (!--system->nr_events) {
1193 struct event_filter *filter = system->filter;
1195 debugfs_remove_recursive(system->entry);
1196 list_del(&system->list);
1198 kfree(filter->filter_string);
1201 kfree(system->name);
1210 * Must be called under locking both of event_mutex and trace_event_mutex.
1212 static void __trace_remove_event_call(struct ftrace_event_call *call)
1214 ftrace_event_enable_disable(call, 0);
1215 if (call->event.funcs)
1216 __unregister_ftrace_event(&call->event);
1217 debugfs_remove_recursive(call->dir);
1218 list_del(&call->list);
1219 trace_destroy_fields(call);
1220 destroy_preds(call);
1221 remove_subsystem_dir(call->class->system);
1224 /* Remove an event_call */
1225 void trace_remove_event_call(struct ftrace_event_call *call)
1227 mutex_lock(&event_mutex);
1228 down_write(&trace_event_mutex);
1229 __trace_remove_event_call(call);
1230 up_write(&trace_event_mutex);
1231 mutex_unlock(&event_mutex);
1234 #define for_each_event(event, start, end) \
1235 for (event = start; \
1236 (unsigned long)event < (unsigned long)end; \
1239 #ifdef CONFIG_MODULES
1241 static LIST_HEAD(ftrace_module_file_list);
1244 * Modules must own their file_operations to keep up with
1245 * reference counting.
1247 struct ftrace_module_file_ops {
1248 struct list_head list;
1250 struct file_operations id;
1251 struct file_operations enable;
1252 struct file_operations format;
1253 struct file_operations filter;
1256 static struct ftrace_module_file_ops *
1257 trace_create_file_ops(struct module *mod)
1259 struct ftrace_module_file_ops *file_ops;
1262 * This is a bit of a PITA. To allow for correct reference
1263 * counting, modules must "own" their file_operations.
1264 * To do this, we allocate the file operations that will be
1265 * used in the event directory.
1268 file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1272 file_ops->mod = mod;
1274 file_ops->id = ftrace_event_id_fops;
1275 file_ops->id.owner = mod;
1277 file_ops->enable = ftrace_enable_fops;
1278 file_ops->enable.owner = mod;
1280 file_ops->filter = ftrace_event_filter_fops;
1281 file_ops->filter.owner = mod;
1283 file_ops->format = ftrace_event_format_fops;
1284 file_ops->format.owner = mod;
1286 list_add(&file_ops->list, &ftrace_module_file_list);
1291 static void trace_module_add_events(struct module *mod)
1293 struct ftrace_module_file_ops *file_ops = NULL;
1294 struct ftrace_event_call *call, *start, *end;
1296 start = mod->trace_events;
1297 end = mod->trace_events + mod->num_trace_events;
1302 file_ops = trace_create_file_ops(mod);
1306 for_each_event(call, start, end) {
1307 __trace_add_event_call(call, mod,
1308 &file_ops->id, &file_ops->enable,
1309 &file_ops->filter, &file_ops->format);
1313 static void trace_module_remove_events(struct module *mod)
1315 struct ftrace_module_file_ops *file_ops;
1316 struct ftrace_event_call *call, *p;
1319 down_write(&trace_event_mutex);
1320 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1321 if (call->mod == mod) {
1323 __trace_remove_event_call(call);
1327 /* Now free the file_operations */
1328 list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1329 if (file_ops->mod == mod)
1332 if (&file_ops->list != &ftrace_module_file_list) {
1333 list_del(&file_ops->list);
1338 * It is safest to reset the ring buffer if the module being unloaded
1339 * registered any events.
1342 tracing_reset_current_online_cpus();
1343 up_write(&trace_event_mutex);
1346 static int trace_module_notify(struct notifier_block *self,
1347 unsigned long val, void *data)
1349 struct module *mod = data;
1351 mutex_lock(&event_mutex);
1353 case MODULE_STATE_COMING:
1354 trace_module_add_events(mod);
1356 case MODULE_STATE_GOING:
1357 trace_module_remove_events(mod);
1360 mutex_unlock(&event_mutex);
1365 static int trace_module_notify(struct notifier_block *self,
1366 unsigned long val, void *data)
1370 #endif /* CONFIG_MODULES */
1372 static struct notifier_block trace_module_nb = {
1373 .notifier_call = trace_module_notify,
1377 extern struct ftrace_event_call __start_ftrace_events[];
1378 extern struct ftrace_event_call __stop_ftrace_events[];
1380 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1382 static __init int setup_trace_event(char *str)
1384 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1385 ring_buffer_expanded = 1;
1386 tracing_selftest_disabled = 1;
1390 __setup("trace_event=", setup_trace_event);
1392 static __init int event_trace_init(void)
1394 struct ftrace_event_call *call;
1395 struct dentry *d_tracer;
1396 struct dentry *entry;
1397 struct dentry *d_events;
1399 char *buf = bootup_event_buf;
1402 d_tracer = tracing_init_dentry();
1406 entry = debugfs_create_file("available_events", 0444, d_tracer,
1407 (void *)&show_event_seq_ops,
1408 &ftrace_avail_fops);
1410 pr_warning("Could not create debugfs "
1411 "'available_events' entry\n");
1413 entry = debugfs_create_file("set_event", 0644, d_tracer,
1414 (void *)&show_set_event_seq_ops,
1415 &ftrace_set_event_fops);
1417 pr_warning("Could not create debugfs "
1418 "'set_event' entry\n");
1420 d_events = event_trace_events_dir();
1424 /* ring buffer internal formats */
1425 trace_create_file("header_page", 0444, d_events,
1426 ring_buffer_print_page_header,
1427 &ftrace_show_header_fops);
1429 trace_create_file("header_event", 0444, d_events,
1430 ring_buffer_print_entry_header,
1431 &ftrace_show_header_fops);
1433 trace_create_file("enable", 0644, d_events,
1434 NULL, &ftrace_system_enable_fops);
1436 if (trace_define_common_fields())
1437 pr_warning("tracing: Failed to allocate common fields");
1439 for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
1440 __trace_add_event_call(call, NULL, &ftrace_event_id_fops,
1441 &ftrace_enable_fops,
1442 &ftrace_event_filter_fops,
1443 &ftrace_event_format_fops);
1447 token = strsep(&buf, ",");
1454 ret = ftrace_set_clr_event(token, 1);
1456 pr_warning("Failed to enable trace event: %s\n", token);
1459 ret = register_module_notifier(&trace_module_nb);
1461 pr_warning("Failed to register trace events module notifier\n");
1465 fs_initcall(event_trace_init);
1467 #ifdef CONFIG_FTRACE_STARTUP_TEST
1469 static DEFINE_SPINLOCK(test_spinlock);
1470 static DEFINE_SPINLOCK(test_spinlock_irq);
1471 static DEFINE_MUTEX(test_mutex);
1473 static __init void test_work(struct work_struct *dummy)
1475 spin_lock(&test_spinlock);
1476 spin_lock_irq(&test_spinlock_irq);
1478 spin_unlock_irq(&test_spinlock_irq);
1479 spin_unlock(&test_spinlock);
1481 mutex_lock(&test_mutex);
1483 mutex_unlock(&test_mutex);
1486 static __init int event_test_thread(void *unused)
1490 test_malloc = kmalloc(1234, GFP_KERNEL);
1492 pr_info("failed to kmalloc\n");
1494 schedule_on_each_cpu(test_work);
1498 set_current_state(TASK_INTERRUPTIBLE);
1499 while (!kthread_should_stop())
1506 * Do various things that may trigger events.
1508 static __init void event_test_stuff(void)
1510 struct task_struct *test_thread;
1512 test_thread = kthread_run(event_test_thread, NULL, "test-events");
1514 kthread_stop(test_thread);
1518 * For every trace event defined, we will test each trace point separately,
1519 * and then by groups, and finally all trace points.
1521 static __init void event_trace_self_tests(void)
1523 struct ftrace_event_call *call;
1524 struct event_subsystem *system;
1527 pr_info("Running tests on trace events:\n");
1529 list_for_each_entry(call, &ftrace_events, list) {
1531 /* Only test those that have a probe */
1532 if (!call->class || !call->class->probe)
1536 * Testing syscall events here is pretty useless, but
1537 * we still do it if configured. But this is time consuming.
1538 * What we really need is a user thread to perform the
1539 * syscalls as we test.
1541 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1542 if (call->class->system &&
1543 strcmp(call->class->system, "syscalls") == 0)
1547 pr_info("Testing event %s: ", call->name);
1550 * If an event is already enabled, someone is using
1551 * it and the self test should not be on.
1553 if (call->flags & TRACE_EVENT_FL_ENABLED) {
1554 pr_warning("Enabled event during self test!\n");
1559 ftrace_event_enable_disable(call, 1);
1561 ftrace_event_enable_disable(call, 0);
1566 /* Now test at the sub system level */
1568 pr_info("Running tests on trace event systems:\n");
1570 list_for_each_entry(system, &event_subsystems, list) {
1572 /* the ftrace system is special, skip it */
1573 if (strcmp(system->name, "ftrace") == 0)
1576 pr_info("Testing event system %s: ", system->name);
1578 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1579 if (WARN_ON_ONCE(ret)) {
1580 pr_warning("error enabling system %s\n",
1587 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1588 if (WARN_ON_ONCE(ret))
1589 pr_warning("error disabling system %s\n",
1595 /* Test with all events enabled */
1597 pr_info("Running tests on all trace events:\n");
1598 pr_info("Testing all events: ");
1600 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1601 if (WARN_ON_ONCE(ret)) {
1602 pr_warning("error enabling all events\n");
1609 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1610 if (WARN_ON_ONCE(ret)) {
1611 pr_warning("error disabling all events\n");
1618 #ifdef CONFIG_FUNCTION_TRACER
1620 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1623 function_test_events_call(unsigned long ip, unsigned long parent_ip)
1625 struct ring_buffer_event *event;
1626 struct ring_buffer *buffer;
1627 struct ftrace_entry *entry;
1628 unsigned long flags;
1633 pc = preempt_count();
1634 preempt_disable_notrace();
1635 cpu = raw_smp_processor_id();
1636 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1641 local_save_flags(flags);
1643 event = trace_current_buffer_lock_reserve(&buffer,
1644 TRACE_FN, sizeof(*entry),
1648 entry = ring_buffer_event_data(event);
1650 entry->parent_ip = parent_ip;
1652 trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
1655 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1656 preempt_enable_notrace();
1659 static struct ftrace_ops trace_ops __initdata =
1661 .func = function_test_events_call,
1664 static __init void event_trace_self_test_with_function(void)
1666 register_ftrace_function(&trace_ops);
1667 pr_info("Running tests again, along with the function tracer\n");
1668 event_trace_self_tests();
1669 unregister_ftrace_function(&trace_ops);
1672 static __init void event_trace_self_test_with_function(void)
1677 static __init int event_trace_self_tests_init(void)
1679 if (!tracing_selftest_disabled) {
1680 event_trace_self_tests();
1681 event_trace_self_test_with_function();
1687 late_initcall(event_trace_self_tests_init);