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);
32 int trace_define_field(struct ftrace_event_call *call, const char *type,
33 const char *name, int offset, int size, int is_signed,
36 struct ftrace_event_field *field;
38 field = kzalloc(sizeof(*field), GFP_KERNEL);
42 field->name = kstrdup(name, GFP_KERNEL);
46 field->type = kstrdup(type, GFP_KERNEL);
50 if (filter_type == FILTER_OTHER)
51 field->filter_type = filter_assign_type(type);
53 field->filter_type = filter_type;
55 field->offset = offset;
57 field->is_signed = is_signed;
59 list_add(&field->link, &call->fields);
70 EXPORT_SYMBOL_GPL(trace_define_field);
72 #define __common_field(type, item) \
73 ret = trace_define_field(call, #type, "common_" #item, \
74 offsetof(typeof(ent), item), \
76 is_signed_type(type), FILTER_OTHER); \
80 static int trace_define_common_fields(struct ftrace_event_call *call)
83 struct trace_entry ent;
85 __common_field(unsigned short, type);
86 __common_field(unsigned char, flags);
87 __common_field(unsigned char, preempt_count);
88 __common_field(int, pid);
89 __common_field(int, lock_depth);
94 void trace_destroy_fields(struct ftrace_event_call *call)
96 struct ftrace_event_field *field, *next;
98 list_for_each_entry_safe(field, next, &call->fields, link) {
99 list_del(&field->link);
106 int trace_event_raw_init(struct ftrace_event_call *call)
110 id = register_ftrace_event(call->event);
114 INIT_LIST_HEAD(&call->fields);
118 EXPORT_SYMBOL_GPL(trace_event_raw_init);
120 static int ftrace_event_enable_disable(struct ftrace_event_call *call,
129 tracing_stop_cmdline_record();
130 call->unregfunc(call);
134 if (!call->enabled) {
135 tracing_start_cmdline_record();
136 ret = call->regfunc(call);
138 tracing_stop_cmdline_record();
139 pr_info("event trace: Could not enable event "
151 static void ftrace_clear_events(void)
153 struct ftrace_event_call *call;
155 mutex_lock(&event_mutex);
156 list_for_each_entry(call, &ftrace_events, list) {
157 ftrace_event_enable_disable(call, 0);
159 mutex_unlock(&event_mutex);
163 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
165 static int __ftrace_set_clr_event(const char *match, const char *sub,
166 const char *event, int set)
168 struct ftrace_event_call *call;
171 mutex_lock(&event_mutex);
172 list_for_each_entry(call, &ftrace_events, list) {
174 if (!call->name || !call->regfunc)
178 strcmp(match, call->name) != 0 &&
179 strcmp(match, call->system) != 0)
182 if (sub && strcmp(sub, call->system) != 0)
185 if (event && strcmp(event, call->name) != 0)
188 ftrace_event_enable_disable(call, set);
192 mutex_unlock(&event_mutex);
197 static int ftrace_set_clr_event(char *buf, int set)
199 char *event = NULL, *sub = NULL, *match;
202 * The buf format can be <subsystem>:<event-name>
203 * *:<event-name> means any event by that name.
204 * :<event-name> is the same.
206 * <subsystem>:* means all events in that subsystem
207 * <subsystem>: means the same.
209 * <name> (no ':') means all events in a subsystem with
210 * the name <name> or any event that matches <name>
213 match = strsep(&buf, ":");
219 if (!strlen(sub) || strcmp(sub, "*") == 0)
221 if (!strlen(event) || strcmp(event, "*") == 0)
225 return __ftrace_set_clr_event(match, sub, event, set);
229 * trace_set_clr_event - enable or disable an event
230 * @system: system name to match (NULL for any system)
231 * @event: event name to match (NULL for all events, within system)
232 * @set: 1 to enable, 0 to disable
234 * This is a way for other parts of the kernel to enable or disable
237 * Returns 0 on success, -EINVAL if the parameters do not match any
240 int trace_set_clr_event(const char *system, const char *event, int set)
242 return __ftrace_set_clr_event(NULL, system, event, set);
245 /* 128 should be much more than enough */
246 #define EVENT_BUF_SIZE 127
249 ftrace_event_write(struct file *file, const char __user *ubuf,
250 size_t cnt, loff_t *ppos)
252 struct trace_parser parser;
258 ret = tracing_update_buffers();
262 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
265 read = trace_get_user(&parser, ubuf, cnt, ppos);
267 if (read >= 0 && trace_parser_loaded((&parser))) {
270 if (*parser.buffer == '!')
273 parser.buffer[parser.idx] = 0;
275 ret = ftrace_set_clr_event(parser.buffer + !set, set);
283 trace_parser_put(&parser);
289 t_next(struct seq_file *m, void *v, loff_t *pos)
291 struct ftrace_event_call *call = v;
295 list_for_each_entry_continue(call, &ftrace_events, list) {
297 * The ftrace subsystem is for showing formats only.
298 * They can not be enabled or disabled via the event files.
307 static void *t_start(struct seq_file *m, loff_t *pos)
309 struct ftrace_event_call *call;
312 mutex_lock(&event_mutex);
314 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
315 for (l = 0; l <= *pos; ) {
316 call = t_next(m, call, &l);
324 s_next(struct seq_file *m, void *v, loff_t *pos)
326 struct ftrace_event_call *call = v;
330 list_for_each_entry_continue(call, &ftrace_events, list) {
338 static void *s_start(struct seq_file *m, loff_t *pos)
340 struct ftrace_event_call *call;
343 mutex_lock(&event_mutex);
345 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
346 for (l = 0; l <= *pos; ) {
347 call = s_next(m, call, &l);
354 static int t_show(struct seq_file *m, void *v)
356 struct ftrace_event_call *call = v;
358 if (strcmp(call->system, TRACE_SYSTEM) != 0)
359 seq_printf(m, "%s:", call->system);
360 seq_printf(m, "%s\n", call->name);
365 static void t_stop(struct seq_file *m, void *p)
367 mutex_unlock(&event_mutex);
371 ftrace_event_seq_open(struct inode *inode, struct file *file)
373 const struct seq_operations *seq_ops;
375 if ((file->f_mode & FMODE_WRITE) &&
376 (file->f_flags & O_TRUNC))
377 ftrace_clear_events();
379 seq_ops = inode->i_private;
380 return seq_open(file, seq_ops);
384 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
387 struct ftrace_event_call *call = filp->private_data;
395 return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
399 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
402 struct ftrace_event_call *call = filp->private_data;
407 if (cnt >= sizeof(buf))
410 if (copy_from_user(&buf, ubuf, cnt))
415 ret = strict_strtoul(buf, 10, &val);
419 ret = tracing_update_buffers();
426 mutex_lock(&event_mutex);
427 ret = ftrace_event_enable_disable(call, val);
428 mutex_unlock(&event_mutex);
437 return ret ? ret : cnt;
441 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
444 const char set_to_char[4] = { '?', '0', '1', 'X' };
445 const char *system = filp->private_data;
446 struct ftrace_event_call *call;
451 mutex_lock(&event_mutex);
452 list_for_each_entry(call, &ftrace_events, list) {
453 if (!call->name || !call->regfunc)
456 if (system && strcmp(call->system, system) != 0)
460 * We need to find out if all the events are set
461 * or if all events or cleared, or if we have
464 set |= (1 << !!call->enabled);
467 * If we have a mixture, no need to look further.
472 mutex_unlock(&event_mutex);
474 buf[0] = set_to_char[set];
477 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
483 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
486 const char *system = filp->private_data;
491 if (cnt >= sizeof(buf))
494 if (copy_from_user(&buf, ubuf, cnt))
499 ret = strict_strtoul(buf, 10, &val);
503 ret = tracing_update_buffers();
507 if (val != 0 && val != 1)
510 ret = __ftrace_set_clr_event(NULL, system, NULL, val);
523 event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
526 struct ftrace_event_call *call = filp->private_data;
527 struct ftrace_event_field *field;
529 int common_field_count = 5;
536 s = kmalloc(sizeof(*s), GFP_KERNEL);
542 trace_seq_printf(s, "name: %s\n", call->name);
543 trace_seq_printf(s, "ID: %d\n", call->id);
544 trace_seq_printf(s, "format:\n");
546 list_for_each_entry_reverse(field, &call->fields, link) {
548 * Smartly shows the array type(except dynamic array).
551 * If TYPE := TYPE[LEN], it is shown:
552 * field:TYPE VAR[LEN]
554 const char *array_descriptor = strchr(field->type, '[');
556 if (!strncmp(field->type, "__data_loc", 10))
557 array_descriptor = NULL;
559 if (!array_descriptor) {
560 r = trace_seq_printf(s, "\tfield:%s %s;\toffset:%u;"
561 "\tsize:%u;\tsigned:%d;\n",
562 field->type, field->name, field->offset,
563 field->size, !!field->is_signed);
565 r = trace_seq_printf(s, "\tfield:%.*s %s%s;\toffset:%u;"
566 "\tsize:%u;\tsigned:%d;\n",
567 (int)(array_descriptor - field->type),
568 field->type, field->name,
569 array_descriptor, field->offset,
570 field->size, !!field->is_signed);
573 if (--common_field_count == 0)
574 r = trace_seq_printf(s, "\n");
581 r = trace_seq_printf(s, "\nprint fmt: %s\n",
586 * ug! The format output is bigger than a PAGE!!
588 buf = "FORMAT TOO BIG\n";
589 r = simple_read_from_buffer(ubuf, cnt, ppos,
594 r = simple_read_from_buffer(ubuf, cnt, ppos,
602 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
604 struct ftrace_event_call *call = filp->private_data;
611 s = kmalloc(sizeof(*s), GFP_KERNEL);
616 trace_seq_printf(s, "%d\n", call->id);
618 r = simple_read_from_buffer(ubuf, cnt, ppos,
625 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
628 struct ftrace_event_call *call = filp->private_data;
635 s = kmalloc(sizeof(*s), GFP_KERNEL);
641 print_event_filter(call, s);
642 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
650 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
653 struct ftrace_event_call *call = filp->private_data;
657 if (cnt >= PAGE_SIZE)
660 buf = (char *)__get_free_page(GFP_TEMPORARY);
664 if (copy_from_user(buf, ubuf, cnt)) {
665 free_page((unsigned long) buf);
670 err = apply_event_filter(call, buf);
671 free_page((unsigned long) buf);
681 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
684 struct event_subsystem *system = filp->private_data;
691 s = kmalloc(sizeof(*s), GFP_KERNEL);
697 print_subsystem_event_filter(system, s);
698 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
706 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
709 struct event_subsystem *system = filp->private_data;
713 if (cnt >= PAGE_SIZE)
716 buf = (char *)__get_free_page(GFP_TEMPORARY);
720 if (copy_from_user(buf, ubuf, cnt)) {
721 free_page((unsigned long) buf);
726 err = apply_subsystem_event_filter(system, buf);
727 free_page((unsigned long) buf);
737 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
739 int (*func)(struct trace_seq *s) = filp->private_data;
746 s = kmalloc(sizeof(*s), GFP_KERNEL);
753 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
760 static const struct seq_operations show_event_seq_ops = {
767 static const struct seq_operations show_set_event_seq_ops = {
774 static const struct file_operations ftrace_avail_fops = {
775 .open = ftrace_event_seq_open,
778 .release = seq_release,
781 static const struct file_operations ftrace_set_event_fops = {
782 .open = ftrace_event_seq_open,
784 .write = ftrace_event_write,
786 .release = seq_release,
789 static const struct file_operations ftrace_enable_fops = {
790 .open = tracing_open_generic,
791 .read = event_enable_read,
792 .write = event_enable_write,
795 static const struct file_operations ftrace_event_format_fops = {
796 .open = tracing_open_generic,
797 .read = event_format_read,
800 static const struct file_operations ftrace_event_id_fops = {
801 .open = tracing_open_generic,
802 .read = event_id_read,
805 static const struct file_operations ftrace_event_filter_fops = {
806 .open = tracing_open_generic,
807 .read = event_filter_read,
808 .write = event_filter_write,
811 static const struct file_operations ftrace_subsystem_filter_fops = {
812 .open = tracing_open_generic,
813 .read = subsystem_filter_read,
814 .write = subsystem_filter_write,
817 static const struct file_operations ftrace_system_enable_fops = {
818 .open = tracing_open_generic,
819 .read = system_enable_read,
820 .write = system_enable_write,
823 static const struct file_operations ftrace_show_header_fops = {
824 .open = tracing_open_generic,
828 static struct dentry *event_trace_events_dir(void)
830 static struct dentry *d_tracer;
831 static struct dentry *d_events;
836 d_tracer = tracing_init_dentry();
840 d_events = debugfs_create_dir("events", d_tracer);
842 pr_warning("Could not create debugfs "
843 "'events' directory\n");
848 static LIST_HEAD(event_subsystems);
850 static struct dentry *
851 event_subsystem_dir(const char *name, struct dentry *d_events)
853 struct event_subsystem *system;
854 struct dentry *entry;
856 /* First see if we did not already create this dir */
857 list_for_each_entry(system, &event_subsystems, list) {
858 if (strcmp(system->name, name) == 0) {
860 return system->entry;
864 /* need to create new entry */
865 system = kmalloc(sizeof(*system), GFP_KERNEL);
867 pr_warning("No memory to create event subsystem %s\n",
872 system->entry = debugfs_create_dir(name, d_events);
873 if (!system->entry) {
874 pr_warning("Could not create event subsystem %s\n",
880 system->nr_events = 1;
881 system->name = kstrdup(name, GFP_KERNEL);
883 debugfs_remove(system->entry);
888 list_add(&system->list, &event_subsystems);
890 system->filter = NULL;
892 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
893 if (!system->filter) {
894 pr_warning("Could not allocate filter for subsystem "
896 return system->entry;
899 entry = debugfs_create_file("filter", 0644, system->entry, system,
900 &ftrace_subsystem_filter_fops);
902 kfree(system->filter);
903 system->filter = NULL;
904 pr_warning("Could not create debugfs "
905 "'%s/filter' entry\n", name);
908 trace_create_file("enable", 0644, system->entry,
909 (void *)system->name,
910 &ftrace_system_enable_fops);
912 return system->entry;
916 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
917 const struct file_operations *id,
918 const struct file_operations *enable,
919 const struct file_operations *filter,
920 const struct file_operations *format)
925 * If the trace point header did not define TRACE_SYSTEM
926 * then the system would be called "TRACE_SYSTEM".
928 if (strcmp(call->system, TRACE_SYSTEM) != 0)
929 d_events = event_subsystem_dir(call->system, d_events);
931 call->dir = debugfs_create_dir(call->name, d_events);
933 pr_warning("Could not create debugfs "
934 "'%s' directory\n", call->name);
939 trace_create_file("enable", 0644, call->dir, call,
942 if (call->id && call->perf_event_enable)
943 trace_create_file("id", 0444, call->dir, call,
946 if (call->define_fields) {
947 ret = trace_define_common_fields(call);
949 ret = call->define_fields(call);
951 pr_warning("Could not initialize trace point"
952 " events/%s\n", call->name);
955 trace_create_file("filter", 0644, call->dir, call,
959 trace_create_file("format", 0444, call->dir, call,
965 static int __trace_add_event_call(struct ftrace_event_call *call)
967 struct dentry *d_events;
973 if (call->raw_init) {
974 ret = call->raw_init(call);
977 pr_warning("Could not initialize trace "
978 "events/%s\n", call->name);
983 d_events = event_trace_events_dir();
987 ret = event_create_dir(call, d_events, &ftrace_event_id_fops,
988 &ftrace_enable_fops, &ftrace_event_filter_fops,
989 &ftrace_event_format_fops);
991 list_add(&call->list, &ftrace_events);
996 /* Add an additional event_call dynamically */
997 int trace_add_event_call(struct ftrace_event_call *call)
1000 mutex_lock(&event_mutex);
1001 ret = __trace_add_event_call(call);
1002 mutex_unlock(&event_mutex);
1006 static void remove_subsystem_dir(const char *name)
1008 struct event_subsystem *system;
1010 if (strcmp(name, TRACE_SYSTEM) == 0)
1013 list_for_each_entry(system, &event_subsystems, list) {
1014 if (strcmp(system->name, name) == 0) {
1015 if (!--system->nr_events) {
1016 struct event_filter *filter = system->filter;
1018 debugfs_remove_recursive(system->entry);
1019 list_del(&system->list);
1021 kfree(filter->filter_string);
1024 kfree(system->name);
1033 * Must be called under locking both of event_mutex and trace_event_mutex.
1035 static void __trace_remove_event_call(struct ftrace_event_call *call)
1037 ftrace_event_enable_disable(call, 0);
1039 __unregister_ftrace_event(call->event);
1040 debugfs_remove_recursive(call->dir);
1041 list_del(&call->list);
1042 trace_destroy_fields(call);
1043 destroy_preds(call);
1044 remove_subsystem_dir(call->system);
1047 /* Remove an event_call */
1048 void trace_remove_event_call(struct ftrace_event_call *call)
1050 mutex_lock(&event_mutex);
1051 down_write(&trace_event_mutex);
1052 __trace_remove_event_call(call);
1053 up_write(&trace_event_mutex);
1054 mutex_unlock(&event_mutex);
1057 #define for_each_event(event, start, end) \
1058 for (event = start; \
1059 (unsigned long)event < (unsigned long)end; \
1062 #ifdef CONFIG_MODULES
1064 static LIST_HEAD(ftrace_module_file_list);
1067 * Modules must own their file_operations to keep up with
1068 * reference counting.
1070 struct ftrace_module_file_ops {
1071 struct list_head list;
1073 struct file_operations id;
1074 struct file_operations enable;
1075 struct file_operations format;
1076 struct file_operations filter;
1079 static struct ftrace_module_file_ops *
1080 trace_create_file_ops(struct module *mod)
1082 struct ftrace_module_file_ops *file_ops;
1085 * This is a bit of a PITA. To allow for correct reference
1086 * counting, modules must "own" their file_operations.
1087 * To do this, we allocate the file operations that will be
1088 * used in the event directory.
1091 file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1095 file_ops->mod = mod;
1097 file_ops->id = ftrace_event_id_fops;
1098 file_ops->id.owner = mod;
1100 file_ops->enable = ftrace_enable_fops;
1101 file_ops->enable.owner = mod;
1103 file_ops->filter = ftrace_event_filter_fops;
1104 file_ops->filter.owner = mod;
1106 file_ops->format = ftrace_event_format_fops;
1107 file_ops->format.owner = mod;
1109 list_add(&file_ops->list, &ftrace_module_file_list);
1114 static void trace_module_add_events(struct module *mod)
1116 struct ftrace_module_file_ops *file_ops = NULL;
1117 struct ftrace_event_call *call, *start, *end;
1118 struct dentry *d_events;
1121 start = mod->trace_events;
1122 end = mod->trace_events + mod->num_trace_events;
1127 d_events = event_trace_events_dir();
1131 for_each_event(call, start, end) {
1132 /* The linker may leave blanks */
1135 if (call->raw_init) {
1136 ret = call->raw_init(call);
1139 pr_warning("Could not initialize trace "
1140 "point events/%s\n", call->name);
1145 * This module has events, create file ops for this module
1146 * if not already done.
1149 file_ops = trace_create_file_ops(mod);
1154 ret = event_create_dir(call, d_events,
1155 &file_ops->id, &file_ops->enable,
1156 &file_ops->filter, &file_ops->format);
1158 list_add(&call->list, &ftrace_events);
1162 static void trace_module_remove_events(struct module *mod)
1164 struct ftrace_module_file_ops *file_ops;
1165 struct ftrace_event_call *call, *p;
1168 down_write(&trace_event_mutex);
1169 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1170 if (call->mod == mod) {
1172 __trace_remove_event_call(call);
1176 /* Now free the file_operations */
1177 list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1178 if (file_ops->mod == mod)
1181 if (&file_ops->list != &ftrace_module_file_list) {
1182 list_del(&file_ops->list);
1187 * It is safest to reset the ring buffer if the module being unloaded
1188 * registered any events.
1191 tracing_reset_current_online_cpus();
1192 up_write(&trace_event_mutex);
1195 static int trace_module_notify(struct notifier_block *self,
1196 unsigned long val, void *data)
1198 struct module *mod = data;
1200 mutex_lock(&event_mutex);
1202 case MODULE_STATE_COMING:
1203 trace_module_add_events(mod);
1205 case MODULE_STATE_GOING:
1206 trace_module_remove_events(mod);
1209 mutex_unlock(&event_mutex);
1214 static int trace_module_notify(struct notifier_block *self,
1215 unsigned long val, void *data)
1219 #endif /* CONFIG_MODULES */
1221 static struct notifier_block trace_module_nb = {
1222 .notifier_call = trace_module_notify,
1226 extern struct ftrace_event_call __start_ftrace_events[];
1227 extern struct ftrace_event_call __stop_ftrace_events[];
1229 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1231 static __init int setup_trace_event(char *str)
1233 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1234 ring_buffer_expanded = 1;
1235 tracing_selftest_disabled = 1;
1239 __setup("trace_event=", setup_trace_event);
1241 static __init int event_trace_init(void)
1243 struct ftrace_event_call *call;
1244 struct dentry *d_tracer;
1245 struct dentry *entry;
1246 struct dentry *d_events;
1248 char *buf = bootup_event_buf;
1251 d_tracer = tracing_init_dentry();
1255 entry = debugfs_create_file("available_events", 0444, d_tracer,
1256 (void *)&show_event_seq_ops,
1257 &ftrace_avail_fops);
1259 pr_warning("Could not create debugfs "
1260 "'available_events' entry\n");
1262 entry = debugfs_create_file("set_event", 0644, d_tracer,
1263 (void *)&show_set_event_seq_ops,
1264 &ftrace_set_event_fops);
1266 pr_warning("Could not create debugfs "
1267 "'set_event' entry\n");
1269 d_events = event_trace_events_dir();
1273 /* ring buffer internal formats */
1274 trace_create_file("header_page", 0444, d_events,
1275 ring_buffer_print_page_header,
1276 &ftrace_show_header_fops);
1278 trace_create_file("header_event", 0444, d_events,
1279 ring_buffer_print_entry_header,
1280 &ftrace_show_header_fops);
1282 trace_create_file("enable", 0644, d_events,
1283 NULL, &ftrace_system_enable_fops);
1285 for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
1286 /* The linker may leave blanks */
1289 if (call->raw_init) {
1290 ret = call->raw_init(call);
1293 pr_warning("Could not initialize trace "
1294 "point events/%s\n", call->name);
1298 ret = event_create_dir(call, d_events, &ftrace_event_id_fops,
1299 &ftrace_enable_fops,
1300 &ftrace_event_filter_fops,
1301 &ftrace_event_format_fops);
1303 list_add(&call->list, &ftrace_events);
1307 token = strsep(&buf, ",");
1314 ret = ftrace_set_clr_event(token, 1);
1316 pr_warning("Failed to enable trace event: %s\n", token);
1319 ret = register_module_notifier(&trace_module_nb);
1321 pr_warning("Failed to register trace events module notifier\n");
1325 fs_initcall(event_trace_init);
1327 #ifdef CONFIG_FTRACE_STARTUP_TEST
1329 static DEFINE_SPINLOCK(test_spinlock);
1330 static DEFINE_SPINLOCK(test_spinlock_irq);
1331 static DEFINE_MUTEX(test_mutex);
1333 static __init void test_work(struct work_struct *dummy)
1335 spin_lock(&test_spinlock);
1336 spin_lock_irq(&test_spinlock_irq);
1338 spin_unlock_irq(&test_spinlock_irq);
1339 spin_unlock(&test_spinlock);
1341 mutex_lock(&test_mutex);
1343 mutex_unlock(&test_mutex);
1346 static __init int event_test_thread(void *unused)
1350 test_malloc = kmalloc(1234, GFP_KERNEL);
1352 pr_info("failed to kmalloc\n");
1354 schedule_on_each_cpu(test_work);
1358 set_current_state(TASK_INTERRUPTIBLE);
1359 while (!kthread_should_stop())
1366 * Do various things that may trigger events.
1368 static __init void event_test_stuff(void)
1370 struct task_struct *test_thread;
1372 test_thread = kthread_run(event_test_thread, NULL, "test-events");
1374 kthread_stop(test_thread);
1378 * For every trace event defined, we will test each trace point separately,
1379 * and then by groups, and finally all trace points.
1381 static __init void event_trace_self_tests(void)
1383 struct ftrace_event_call *call;
1384 struct event_subsystem *system;
1387 pr_info("Running tests on trace events:\n");
1389 list_for_each_entry(call, &ftrace_events, list) {
1391 /* Only test those that have a regfunc */
1396 * Testing syscall events here is pretty useless, but
1397 * we still do it if configured. But this is time consuming.
1398 * What we really need is a user thread to perform the
1399 * syscalls as we test.
1401 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1403 strcmp(call->system, "syscalls") == 0)
1407 pr_info("Testing event %s: ", call->name);
1410 * If an event is already enabled, someone is using
1411 * it and the self test should not be on.
1413 if (call->enabled) {
1414 pr_warning("Enabled event during self test!\n");
1419 ftrace_event_enable_disable(call, 1);
1421 ftrace_event_enable_disable(call, 0);
1426 /* Now test at the sub system level */
1428 pr_info("Running tests on trace event systems:\n");
1430 list_for_each_entry(system, &event_subsystems, list) {
1432 /* the ftrace system is special, skip it */
1433 if (strcmp(system->name, "ftrace") == 0)
1436 pr_info("Testing event system %s: ", system->name);
1438 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1439 if (WARN_ON_ONCE(ret)) {
1440 pr_warning("error enabling system %s\n",
1447 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1448 if (WARN_ON_ONCE(ret))
1449 pr_warning("error disabling system %s\n",
1455 /* Test with all events enabled */
1457 pr_info("Running tests on all trace events:\n");
1458 pr_info("Testing all events: ");
1460 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1461 if (WARN_ON_ONCE(ret)) {
1462 pr_warning("error enabling all events\n");
1469 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1470 if (WARN_ON_ONCE(ret)) {
1471 pr_warning("error disabling all events\n");
1478 #ifdef CONFIG_FUNCTION_TRACER
1480 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1483 function_test_events_call(unsigned long ip, unsigned long parent_ip)
1485 struct ring_buffer_event *event;
1486 struct ring_buffer *buffer;
1487 struct ftrace_entry *entry;
1488 unsigned long flags;
1494 pc = preempt_count();
1495 resched = ftrace_preempt_disable();
1496 cpu = raw_smp_processor_id();
1497 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1502 local_save_flags(flags);
1504 event = trace_current_buffer_lock_reserve(&buffer,
1505 TRACE_FN, sizeof(*entry),
1509 entry = ring_buffer_event_data(event);
1511 entry->parent_ip = parent_ip;
1513 trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
1516 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1517 ftrace_preempt_enable(resched);
1520 static struct ftrace_ops trace_ops __initdata =
1522 .func = function_test_events_call,
1525 static __init void event_trace_self_test_with_function(void)
1527 register_ftrace_function(&trace_ops);
1528 pr_info("Running tests again, along with the function tracer\n");
1529 event_trace_self_tests();
1530 unregister_ftrace_function(&trace_ops);
1533 static __init void event_trace_self_test_with_function(void)
1538 static __init int event_trace_self_tests_init(void)
1540 if (!tracing_selftest_disabled) {
1541 event_trace_self_tests();
1542 event_trace_self_test_with_function();
1548 late_initcall(event_trace_self_tests_init);