Merge git://git.kernel.org/pub/scm/virt/kvm/kvm
[linux-3.10.git] / kernel / trace / trace_events.c
1 /*
2  * event tracer
3  *
4  * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
5  *
6  *  - Added format output of fields of the trace point.
7  *    This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
8  *
9  */
10
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>
20
21 #include <asm/setup.h>
22
23 #include "trace_output.h"
24
25 #undef TRACE_SYSTEM
26 #define TRACE_SYSTEM "TRACE_SYSTEM"
27
28 DEFINE_MUTEX(event_mutex);
29
30 DEFINE_MUTEX(event_storage_mutex);
31 EXPORT_SYMBOL_GPL(event_storage_mutex);
32
33 char event_storage[EVENT_STORAGE_SIZE];
34 EXPORT_SYMBOL_GPL(event_storage);
35
36 LIST_HEAD(ftrace_events);
37 LIST_HEAD(ftrace_common_fields);
38
39 struct list_head *
40 trace_get_fields(struct ftrace_event_call *event_call)
41 {
42         if (!event_call->class->get_fields)
43                 return &event_call->class->fields;
44         return event_call->class->get_fields(event_call);
45 }
46
47 static int __trace_define_field(struct list_head *head, const char *type,
48                                 const char *name, int offset, int size,
49                                 int is_signed, int filter_type)
50 {
51         struct ftrace_event_field *field;
52
53         field = kzalloc(sizeof(*field), GFP_KERNEL);
54         if (!field)
55                 goto err;
56
57         field->name = kstrdup(name, GFP_KERNEL);
58         if (!field->name)
59                 goto err;
60
61         field->type = kstrdup(type, GFP_KERNEL);
62         if (!field->type)
63                 goto err;
64
65         if (filter_type == FILTER_OTHER)
66                 field->filter_type = filter_assign_type(type);
67         else
68                 field->filter_type = filter_type;
69
70         field->offset = offset;
71         field->size = size;
72         field->is_signed = is_signed;
73
74         list_add(&field->link, head);
75
76         return 0;
77
78 err:
79         if (field)
80                 kfree(field->name);
81         kfree(field);
82
83         return -ENOMEM;
84 }
85
86 int trace_define_field(struct ftrace_event_call *call, const char *type,
87                        const char *name, int offset, int size, int is_signed,
88                        int filter_type)
89 {
90         struct list_head *head;
91
92         if (WARN_ON(!call->class))
93                 return 0;
94
95         head = trace_get_fields(call);
96         return __trace_define_field(head, type, name, offset, size,
97                                     is_signed, filter_type);
98 }
99 EXPORT_SYMBOL_GPL(trace_define_field);
100
101 #define __common_field(type, item)                                      \
102         ret = __trace_define_field(&ftrace_common_fields, #type,        \
103                                    "common_" #item,                     \
104                                    offsetof(typeof(ent), item),         \
105                                    sizeof(ent.item),                    \
106                                    is_signed_type(type), FILTER_OTHER); \
107         if (ret)                                                        \
108                 return ret;
109
110 static int trace_define_common_fields(void)
111 {
112         int ret;
113         struct trace_entry ent;
114
115         __common_field(unsigned short, type);
116         __common_field(unsigned char, flags);
117         __common_field(unsigned char, preempt_count);
118         __common_field(int, pid);
119         __common_field(int, padding);
120
121         return ret;
122 }
123
124 void trace_destroy_fields(struct ftrace_event_call *call)
125 {
126         struct ftrace_event_field *field, *next;
127         struct list_head *head;
128
129         head = trace_get_fields(call);
130         list_for_each_entry_safe(field, next, head, link) {
131                 list_del(&field->link);
132                 kfree(field->type);
133                 kfree(field->name);
134                 kfree(field);
135         }
136 }
137
138 int trace_event_raw_init(struct ftrace_event_call *call)
139 {
140         int id;
141
142         id = register_ftrace_event(&call->event);
143         if (!id)
144                 return -ENODEV;
145
146         return 0;
147 }
148 EXPORT_SYMBOL_GPL(trace_event_raw_init);
149
150 int ftrace_event_reg(struct ftrace_event_call *call,
151                      enum trace_reg type, void *data)
152 {
153         switch (type) {
154         case TRACE_REG_REGISTER:
155                 return tracepoint_probe_register(call->name,
156                                                  call->class->probe,
157                                                  call);
158         case TRACE_REG_UNREGISTER:
159                 tracepoint_probe_unregister(call->name,
160                                             call->class->probe,
161                                             call);
162                 return 0;
163
164 #ifdef CONFIG_PERF_EVENTS
165         case TRACE_REG_PERF_REGISTER:
166                 return tracepoint_probe_register(call->name,
167                                                  call->class->perf_probe,
168                                                  call);
169         case TRACE_REG_PERF_UNREGISTER:
170                 tracepoint_probe_unregister(call->name,
171                                             call->class->perf_probe,
172                                             call);
173                 return 0;
174         case TRACE_REG_PERF_OPEN:
175         case TRACE_REG_PERF_CLOSE:
176         case TRACE_REG_PERF_ADD:
177         case TRACE_REG_PERF_DEL:
178                 return 0;
179 #endif
180         }
181         return 0;
182 }
183 EXPORT_SYMBOL_GPL(ftrace_event_reg);
184
185 void trace_event_enable_cmd_record(bool enable)
186 {
187         struct ftrace_event_call *call;
188
189         mutex_lock(&event_mutex);
190         list_for_each_entry(call, &ftrace_events, list) {
191                 if (!(call->flags & TRACE_EVENT_FL_ENABLED))
192                         continue;
193
194                 if (enable) {
195                         tracing_start_cmdline_record();
196                         call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
197                 } else {
198                         tracing_stop_cmdline_record();
199                         call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
200                 }
201         }
202         mutex_unlock(&event_mutex);
203 }
204
205 static int ftrace_event_enable_disable(struct ftrace_event_call *call,
206                                         int enable)
207 {
208         int ret = 0;
209
210         switch (enable) {
211         case 0:
212                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
213                         call->flags &= ~TRACE_EVENT_FL_ENABLED;
214                         if (call->flags & TRACE_EVENT_FL_RECORDED_CMD) {
215                                 tracing_stop_cmdline_record();
216                                 call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
217                         }
218                         call->class->reg(call, TRACE_REG_UNREGISTER, NULL);
219                 }
220                 break;
221         case 1:
222                 if (!(call->flags & TRACE_EVENT_FL_ENABLED)) {
223                         if (trace_flags & TRACE_ITER_RECORD_CMD) {
224                                 tracing_start_cmdline_record();
225                                 call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
226                         }
227                         ret = call->class->reg(call, TRACE_REG_REGISTER, NULL);
228                         if (ret) {
229                                 tracing_stop_cmdline_record();
230                                 pr_info("event trace: Could not enable event "
231                                         "%s\n", call->name);
232                                 break;
233                         }
234                         call->flags |= TRACE_EVENT_FL_ENABLED;
235                 }
236                 break;
237         }
238
239         return ret;
240 }
241
242 static void ftrace_clear_events(void)
243 {
244         struct ftrace_event_call *call;
245
246         mutex_lock(&event_mutex);
247         list_for_each_entry(call, &ftrace_events, list) {
248                 ftrace_event_enable_disable(call, 0);
249         }
250         mutex_unlock(&event_mutex);
251 }
252
253 static void __put_system(struct event_subsystem *system)
254 {
255         struct event_filter *filter = system->filter;
256
257         WARN_ON_ONCE(system->ref_count == 0);
258         if (--system->ref_count)
259                 return;
260
261         if (filter) {
262                 kfree(filter->filter_string);
263                 kfree(filter);
264         }
265         kfree(system->name);
266         kfree(system);
267 }
268
269 static void __get_system(struct event_subsystem *system)
270 {
271         WARN_ON_ONCE(system->ref_count == 0);
272         system->ref_count++;
273 }
274
275 static void put_system(struct event_subsystem *system)
276 {
277         mutex_lock(&event_mutex);
278         __put_system(system);
279         mutex_unlock(&event_mutex);
280 }
281
282 /*
283  * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
284  */
285 static int __ftrace_set_clr_event(const char *match, const char *sub,
286                                   const char *event, int set)
287 {
288         struct ftrace_event_call *call;
289         int ret = -EINVAL;
290
291         mutex_lock(&event_mutex);
292         list_for_each_entry(call, &ftrace_events, list) {
293
294                 if (!call->name || !call->class || !call->class->reg)
295                         continue;
296
297                 if (match &&
298                     strcmp(match, call->name) != 0 &&
299                     strcmp(match, call->class->system) != 0)
300                         continue;
301
302                 if (sub && strcmp(sub, call->class->system) != 0)
303                         continue;
304
305                 if (event && strcmp(event, call->name) != 0)
306                         continue;
307
308                 ftrace_event_enable_disable(call, set);
309
310                 ret = 0;
311         }
312         mutex_unlock(&event_mutex);
313
314         return ret;
315 }
316
317 static int ftrace_set_clr_event(char *buf, int set)
318 {
319         char *event = NULL, *sub = NULL, *match;
320
321         /*
322          * The buf format can be <subsystem>:<event-name>
323          *  *:<event-name> means any event by that name.
324          *  :<event-name> is the same.
325          *
326          *  <subsystem>:* means all events in that subsystem
327          *  <subsystem>: means the same.
328          *
329          *  <name> (no ':') means all events in a subsystem with
330          *  the name <name> or any event that matches <name>
331          */
332
333         match = strsep(&buf, ":");
334         if (buf) {
335                 sub = match;
336                 event = buf;
337                 match = NULL;
338
339                 if (!strlen(sub) || strcmp(sub, "*") == 0)
340                         sub = NULL;
341                 if (!strlen(event) || strcmp(event, "*") == 0)
342                         event = NULL;
343         }
344
345         return __ftrace_set_clr_event(match, sub, event, set);
346 }
347
348 /**
349  * trace_set_clr_event - enable or disable an event
350  * @system: system name to match (NULL for any system)
351  * @event: event name to match (NULL for all events, within system)
352  * @set: 1 to enable, 0 to disable
353  *
354  * This is a way for other parts of the kernel to enable or disable
355  * event recording.
356  *
357  * Returns 0 on success, -EINVAL if the parameters do not match any
358  * registered events.
359  */
360 int trace_set_clr_event(const char *system, const char *event, int set)
361 {
362         return __ftrace_set_clr_event(NULL, system, event, set);
363 }
364 EXPORT_SYMBOL_GPL(trace_set_clr_event);
365
366 /* 128 should be much more than enough */
367 #define EVENT_BUF_SIZE          127
368
369 static ssize_t
370 ftrace_event_write(struct file *file, const char __user *ubuf,
371                    size_t cnt, loff_t *ppos)
372 {
373         struct trace_parser parser;
374         ssize_t read, ret;
375
376         if (!cnt)
377                 return 0;
378
379         ret = tracing_update_buffers();
380         if (ret < 0)
381                 return ret;
382
383         if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
384                 return -ENOMEM;
385
386         read = trace_get_user(&parser, ubuf, cnt, ppos);
387
388         if (read >= 0 && trace_parser_loaded((&parser))) {
389                 int set = 1;
390
391                 if (*parser.buffer == '!')
392                         set = 0;
393
394                 parser.buffer[parser.idx] = 0;
395
396                 ret = ftrace_set_clr_event(parser.buffer + !set, set);
397                 if (ret)
398                         goto out_put;
399         }
400
401         ret = read;
402
403  out_put:
404         trace_parser_put(&parser);
405
406         return ret;
407 }
408
409 static void *
410 t_next(struct seq_file *m, void *v, loff_t *pos)
411 {
412         struct ftrace_event_call *call = v;
413
414         (*pos)++;
415
416         list_for_each_entry_continue(call, &ftrace_events, list) {
417                 /*
418                  * The ftrace subsystem is for showing formats only.
419                  * They can not be enabled or disabled via the event files.
420                  */
421                 if (call->class && call->class->reg)
422                         return call;
423         }
424
425         return NULL;
426 }
427
428 static void *t_start(struct seq_file *m, loff_t *pos)
429 {
430         struct ftrace_event_call *call;
431         loff_t l;
432
433         mutex_lock(&event_mutex);
434
435         call = list_entry(&ftrace_events, struct ftrace_event_call, list);
436         for (l = 0; l <= *pos; ) {
437                 call = t_next(m, call, &l);
438                 if (!call)
439                         break;
440         }
441         return call;
442 }
443
444 static void *
445 s_next(struct seq_file *m, void *v, loff_t *pos)
446 {
447         struct ftrace_event_call *call = v;
448
449         (*pos)++;
450
451         list_for_each_entry_continue(call, &ftrace_events, list) {
452                 if (call->flags & TRACE_EVENT_FL_ENABLED)
453                         return call;
454         }
455
456         return NULL;
457 }
458
459 static void *s_start(struct seq_file *m, loff_t *pos)
460 {
461         struct ftrace_event_call *call;
462         loff_t l;
463
464         mutex_lock(&event_mutex);
465
466         call = list_entry(&ftrace_events, struct ftrace_event_call, list);
467         for (l = 0; l <= *pos; ) {
468                 call = s_next(m, call, &l);
469                 if (!call)
470                         break;
471         }
472         return call;
473 }
474
475 static int t_show(struct seq_file *m, void *v)
476 {
477         struct ftrace_event_call *call = v;
478
479         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
480                 seq_printf(m, "%s:", call->class->system);
481         seq_printf(m, "%s\n", call->name);
482
483         return 0;
484 }
485
486 static void t_stop(struct seq_file *m, void *p)
487 {
488         mutex_unlock(&event_mutex);
489 }
490
491 static int
492 ftrace_event_seq_open(struct inode *inode, struct file *file)
493 {
494         const struct seq_operations *seq_ops;
495
496         if ((file->f_mode & FMODE_WRITE) &&
497             (file->f_flags & O_TRUNC))
498                 ftrace_clear_events();
499
500         seq_ops = inode->i_private;
501         return seq_open(file, seq_ops);
502 }
503
504 static ssize_t
505 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
506                   loff_t *ppos)
507 {
508         struct ftrace_event_call *call = filp->private_data;
509         char *buf;
510
511         if (call->flags & TRACE_EVENT_FL_ENABLED)
512                 buf = "1\n";
513         else
514                 buf = "0\n";
515
516         return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
517 }
518
519 static ssize_t
520 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
521                    loff_t *ppos)
522 {
523         struct ftrace_event_call *call = filp->private_data;
524         unsigned long val;
525         int ret;
526
527         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
528         if (ret)
529                 return ret;
530
531         ret = tracing_update_buffers();
532         if (ret < 0)
533                 return ret;
534
535         switch (val) {
536         case 0:
537         case 1:
538                 mutex_lock(&event_mutex);
539                 ret = ftrace_event_enable_disable(call, val);
540                 mutex_unlock(&event_mutex);
541                 break;
542
543         default:
544                 return -EINVAL;
545         }
546
547         *ppos += cnt;
548
549         return ret ? ret : cnt;
550 }
551
552 static ssize_t
553 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
554                    loff_t *ppos)
555 {
556         const char set_to_char[4] = { '?', '0', '1', 'X' };
557         struct event_subsystem *system = filp->private_data;
558         struct ftrace_event_call *call;
559         char buf[2];
560         int set = 0;
561         int ret;
562
563         mutex_lock(&event_mutex);
564         list_for_each_entry(call, &ftrace_events, list) {
565                 if (!call->name || !call->class || !call->class->reg)
566                         continue;
567
568                 if (system && strcmp(call->class->system, system->name) != 0)
569                         continue;
570
571                 /*
572                  * We need to find out if all the events are set
573                  * or if all events or cleared, or if we have
574                  * a mixture.
575                  */
576                 set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED));
577
578                 /*
579                  * If we have a mixture, no need to look further.
580                  */
581                 if (set == 3)
582                         break;
583         }
584         mutex_unlock(&event_mutex);
585
586         buf[0] = set_to_char[set];
587         buf[1] = '\n';
588
589         ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
590
591         return ret;
592 }
593
594 static ssize_t
595 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
596                     loff_t *ppos)
597 {
598         struct event_subsystem *system = filp->private_data;
599         const char *name = NULL;
600         unsigned long val;
601         ssize_t ret;
602
603         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
604         if (ret)
605                 return ret;
606
607         ret = tracing_update_buffers();
608         if (ret < 0)
609                 return ret;
610
611         if (val != 0 && val != 1)
612                 return -EINVAL;
613
614         /*
615          * Opening of "enable" adds a ref count to system,
616          * so the name is safe to use.
617          */
618         if (system)
619                 name = system->name;
620
621         ret = __ftrace_set_clr_event(NULL, name, NULL, val);
622         if (ret)
623                 goto out;
624
625         ret = cnt;
626
627 out:
628         *ppos += cnt;
629
630         return ret;
631 }
632
633 enum {
634         FORMAT_HEADER           = 1,
635         FORMAT_FIELD_SEPERATOR  = 2,
636         FORMAT_PRINTFMT         = 3,
637 };
638
639 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
640 {
641         struct ftrace_event_call *call = m->private;
642         struct ftrace_event_field *field;
643         struct list_head *common_head = &ftrace_common_fields;
644         struct list_head *head = trace_get_fields(call);
645
646         (*pos)++;
647
648         switch ((unsigned long)v) {
649         case FORMAT_HEADER:
650                 if (unlikely(list_empty(common_head)))
651                         return NULL;
652
653                 field = list_entry(common_head->prev,
654                                    struct ftrace_event_field, link);
655                 return field;
656
657         case FORMAT_FIELD_SEPERATOR:
658                 if (unlikely(list_empty(head)))
659                         return NULL;
660
661                 field = list_entry(head->prev, struct ftrace_event_field, link);
662                 return field;
663
664         case FORMAT_PRINTFMT:
665                 /* all done */
666                 return NULL;
667         }
668
669         field = v;
670         if (field->link.prev == common_head)
671                 return (void *)FORMAT_FIELD_SEPERATOR;
672         else if (field->link.prev == head)
673                 return (void *)FORMAT_PRINTFMT;
674
675         field = list_entry(field->link.prev, struct ftrace_event_field, link);
676
677         return field;
678 }
679
680 static void *f_start(struct seq_file *m, loff_t *pos)
681 {
682         loff_t l = 0;
683         void *p;
684
685         /* Start by showing the header */
686         if (!*pos)
687                 return (void *)FORMAT_HEADER;
688
689         p = (void *)FORMAT_HEADER;
690         do {
691                 p = f_next(m, p, &l);
692         } while (p && l < *pos);
693
694         return p;
695 }
696
697 static int f_show(struct seq_file *m, void *v)
698 {
699         struct ftrace_event_call *call = m->private;
700         struct ftrace_event_field *field;
701         const char *array_descriptor;
702
703         switch ((unsigned long)v) {
704         case FORMAT_HEADER:
705                 seq_printf(m, "name: %s\n", call->name);
706                 seq_printf(m, "ID: %d\n", call->event.type);
707                 seq_printf(m, "format:\n");
708                 return 0;
709
710         case FORMAT_FIELD_SEPERATOR:
711                 seq_putc(m, '\n');
712                 return 0;
713
714         case FORMAT_PRINTFMT:
715                 seq_printf(m, "\nprint fmt: %s\n",
716                            call->print_fmt);
717                 return 0;
718         }
719
720         field = v;
721
722         /*
723          * Smartly shows the array type(except dynamic array).
724          * Normal:
725          *      field:TYPE VAR
726          * If TYPE := TYPE[LEN], it is shown:
727          *      field:TYPE VAR[LEN]
728          */
729         array_descriptor = strchr(field->type, '[');
730
731         if (!strncmp(field->type, "__data_loc", 10))
732                 array_descriptor = NULL;
733
734         if (!array_descriptor)
735                 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
736                            field->type, field->name, field->offset,
737                            field->size, !!field->is_signed);
738         else
739                 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
740                            (int)(array_descriptor - field->type),
741                            field->type, field->name,
742                            array_descriptor, field->offset,
743                            field->size, !!field->is_signed);
744
745         return 0;
746 }
747
748 static void f_stop(struct seq_file *m, void *p)
749 {
750 }
751
752 static const struct seq_operations trace_format_seq_ops = {
753         .start          = f_start,
754         .next           = f_next,
755         .stop           = f_stop,
756         .show           = f_show,
757 };
758
759 static int trace_format_open(struct inode *inode, struct file *file)
760 {
761         struct ftrace_event_call *call = inode->i_private;
762         struct seq_file *m;
763         int ret;
764
765         ret = seq_open(file, &trace_format_seq_ops);
766         if (ret < 0)
767                 return ret;
768
769         m = file->private_data;
770         m->private = call;
771
772         return 0;
773 }
774
775 static ssize_t
776 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
777 {
778         struct ftrace_event_call *call = filp->private_data;
779         struct trace_seq *s;
780         int r;
781
782         if (*ppos)
783                 return 0;
784
785         s = kmalloc(sizeof(*s), GFP_KERNEL);
786         if (!s)
787                 return -ENOMEM;
788
789         trace_seq_init(s);
790         trace_seq_printf(s, "%d\n", call->event.type);
791
792         r = simple_read_from_buffer(ubuf, cnt, ppos,
793                                     s->buffer, s->len);
794         kfree(s);
795         return r;
796 }
797
798 static ssize_t
799 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
800                   loff_t *ppos)
801 {
802         struct ftrace_event_call *call = filp->private_data;
803         struct trace_seq *s;
804         int r;
805
806         if (*ppos)
807                 return 0;
808
809         s = kmalloc(sizeof(*s), GFP_KERNEL);
810         if (!s)
811                 return -ENOMEM;
812
813         trace_seq_init(s);
814
815         print_event_filter(call, s);
816         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
817
818         kfree(s);
819
820         return r;
821 }
822
823 static ssize_t
824 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
825                    loff_t *ppos)
826 {
827         struct ftrace_event_call *call = filp->private_data;
828         char *buf;
829         int err;
830
831         if (cnt >= PAGE_SIZE)
832                 return -EINVAL;
833
834         buf = (char *)__get_free_page(GFP_TEMPORARY);
835         if (!buf)
836                 return -ENOMEM;
837
838         if (copy_from_user(buf, ubuf, cnt)) {
839                 free_page((unsigned long) buf);
840                 return -EFAULT;
841         }
842         buf[cnt] = '\0';
843
844         err = apply_event_filter(call, buf);
845         free_page((unsigned long) buf);
846         if (err < 0)
847                 return err;
848
849         *ppos += cnt;
850
851         return cnt;
852 }
853
854 static LIST_HEAD(event_subsystems);
855
856 static int subsystem_open(struct inode *inode, struct file *filp)
857 {
858         struct event_subsystem *system = NULL;
859         int ret;
860
861         if (!inode->i_private)
862                 goto skip_search;
863
864         /* Make sure the system still exists */
865         mutex_lock(&event_mutex);
866         list_for_each_entry(system, &event_subsystems, list) {
867                 if (system == inode->i_private) {
868                         /* Don't open systems with no events */
869                         if (!system->nr_events) {
870                                 system = NULL;
871                                 break;
872                         }
873                         __get_system(system);
874                         break;
875                 }
876         }
877         mutex_unlock(&event_mutex);
878
879         if (system != inode->i_private)
880                 return -ENODEV;
881
882  skip_search:
883         ret = tracing_open_generic(inode, filp);
884         if (ret < 0 && system)
885                 put_system(system);
886
887         return ret;
888 }
889
890 static int subsystem_release(struct inode *inode, struct file *file)
891 {
892         struct event_subsystem *system = inode->i_private;
893
894         if (system)
895                 put_system(system);
896
897         return 0;
898 }
899
900 static ssize_t
901 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
902                       loff_t *ppos)
903 {
904         struct event_subsystem *system = filp->private_data;
905         struct trace_seq *s;
906         int r;
907
908         if (*ppos)
909                 return 0;
910
911         s = kmalloc(sizeof(*s), GFP_KERNEL);
912         if (!s)
913                 return -ENOMEM;
914
915         trace_seq_init(s);
916
917         print_subsystem_event_filter(system, s);
918         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
919
920         kfree(s);
921
922         return r;
923 }
924
925 static ssize_t
926 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
927                        loff_t *ppos)
928 {
929         struct event_subsystem *system = filp->private_data;
930         char *buf;
931         int err;
932
933         if (cnt >= PAGE_SIZE)
934                 return -EINVAL;
935
936         buf = (char *)__get_free_page(GFP_TEMPORARY);
937         if (!buf)
938                 return -ENOMEM;
939
940         if (copy_from_user(buf, ubuf, cnt)) {
941                 free_page((unsigned long) buf);
942                 return -EFAULT;
943         }
944         buf[cnt] = '\0';
945
946         err = apply_subsystem_event_filter(system, buf);
947         free_page((unsigned long) buf);
948         if (err < 0)
949                 return err;
950
951         *ppos += cnt;
952
953         return cnt;
954 }
955
956 static ssize_t
957 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
958 {
959         int (*func)(struct trace_seq *s) = filp->private_data;
960         struct trace_seq *s;
961         int r;
962
963         if (*ppos)
964                 return 0;
965
966         s = kmalloc(sizeof(*s), GFP_KERNEL);
967         if (!s)
968                 return -ENOMEM;
969
970         trace_seq_init(s);
971
972         func(s);
973         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
974
975         kfree(s);
976
977         return r;
978 }
979
980 static const struct seq_operations show_event_seq_ops = {
981         .start = t_start,
982         .next = t_next,
983         .show = t_show,
984         .stop = t_stop,
985 };
986
987 static const struct seq_operations show_set_event_seq_ops = {
988         .start = s_start,
989         .next = s_next,
990         .show = t_show,
991         .stop = t_stop,
992 };
993
994 static const struct file_operations ftrace_avail_fops = {
995         .open = ftrace_event_seq_open,
996         .read = seq_read,
997         .llseek = seq_lseek,
998         .release = seq_release,
999 };
1000
1001 static const struct file_operations ftrace_set_event_fops = {
1002         .open = ftrace_event_seq_open,
1003         .read = seq_read,
1004         .write = ftrace_event_write,
1005         .llseek = seq_lseek,
1006         .release = seq_release,
1007 };
1008
1009 static const struct file_operations ftrace_enable_fops = {
1010         .open = tracing_open_generic,
1011         .read = event_enable_read,
1012         .write = event_enable_write,
1013         .llseek = default_llseek,
1014 };
1015
1016 static const struct file_operations ftrace_event_format_fops = {
1017         .open = trace_format_open,
1018         .read = seq_read,
1019         .llseek = seq_lseek,
1020         .release = seq_release,
1021 };
1022
1023 static const struct file_operations ftrace_event_id_fops = {
1024         .open = tracing_open_generic,
1025         .read = event_id_read,
1026         .llseek = default_llseek,
1027 };
1028
1029 static const struct file_operations ftrace_event_filter_fops = {
1030         .open = tracing_open_generic,
1031         .read = event_filter_read,
1032         .write = event_filter_write,
1033         .llseek = default_llseek,
1034 };
1035
1036 static const struct file_operations ftrace_subsystem_filter_fops = {
1037         .open = subsystem_open,
1038         .read = subsystem_filter_read,
1039         .write = subsystem_filter_write,
1040         .llseek = default_llseek,
1041         .release = subsystem_release,
1042 };
1043
1044 static const struct file_operations ftrace_system_enable_fops = {
1045         .open = subsystem_open,
1046         .read = system_enable_read,
1047         .write = system_enable_write,
1048         .llseek = default_llseek,
1049         .release = subsystem_release,
1050 };
1051
1052 static const struct file_operations ftrace_show_header_fops = {
1053         .open = tracing_open_generic,
1054         .read = show_header,
1055         .llseek = default_llseek,
1056 };
1057
1058 static struct dentry *event_trace_events_dir(void)
1059 {
1060         static struct dentry *d_tracer;
1061         static struct dentry *d_events;
1062
1063         if (d_events)
1064                 return d_events;
1065
1066         d_tracer = tracing_init_dentry();
1067         if (!d_tracer)
1068                 return NULL;
1069
1070         d_events = debugfs_create_dir("events", d_tracer);
1071         if (!d_events)
1072                 pr_warning("Could not create debugfs "
1073                            "'events' directory\n");
1074
1075         return d_events;
1076 }
1077
1078 static struct dentry *
1079 event_subsystem_dir(const char *name, struct dentry *d_events)
1080 {
1081         struct event_subsystem *system;
1082         struct dentry *entry;
1083
1084         /* First see if we did not already create this dir */
1085         list_for_each_entry(system, &event_subsystems, list) {
1086                 if (strcmp(system->name, name) == 0) {
1087                         system->nr_events++;
1088                         return system->entry;
1089                 }
1090         }
1091
1092         /* need to create new entry */
1093         system = kmalloc(sizeof(*system), GFP_KERNEL);
1094         if (!system) {
1095                 pr_warning("No memory to create event subsystem %s\n",
1096                            name);
1097                 return d_events;
1098         }
1099
1100         system->entry = debugfs_create_dir(name, d_events);
1101         if (!system->entry) {
1102                 pr_warning("Could not create event subsystem %s\n",
1103                            name);
1104                 kfree(system);
1105                 return d_events;
1106         }
1107
1108         system->nr_events = 1;
1109         system->ref_count = 1;
1110         system->name = kstrdup(name, GFP_KERNEL);
1111         if (!system->name) {
1112                 debugfs_remove(system->entry);
1113                 kfree(system);
1114                 return d_events;
1115         }
1116
1117         list_add(&system->list, &event_subsystems);
1118
1119         system->filter = NULL;
1120
1121         system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1122         if (!system->filter) {
1123                 pr_warning("Could not allocate filter for subsystem "
1124                            "'%s'\n", name);
1125                 return system->entry;
1126         }
1127
1128         entry = debugfs_create_file("filter", 0644, system->entry, system,
1129                                     &ftrace_subsystem_filter_fops);
1130         if (!entry) {
1131                 kfree(system->filter);
1132                 system->filter = NULL;
1133                 pr_warning("Could not create debugfs "
1134                            "'%s/filter' entry\n", name);
1135         }
1136
1137         trace_create_file("enable", 0644, system->entry, system,
1138                           &ftrace_system_enable_fops);
1139
1140         return system->entry;
1141 }
1142
1143 static int
1144 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
1145                  const struct file_operations *id,
1146                  const struct file_operations *enable,
1147                  const struct file_operations *filter,
1148                  const struct file_operations *format)
1149 {
1150         struct list_head *head;
1151         int ret;
1152
1153         /*
1154          * If the trace point header did not define TRACE_SYSTEM
1155          * then the system would be called "TRACE_SYSTEM".
1156          */
1157         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1158                 d_events = event_subsystem_dir(call->class->system, d_events);
1159
1160         call->dir = debugfs_create_dir(call->name, d_events);
1161         if (!call->dir) {
1162                 pr_warning("Could not create debugfs "
1163                            "'%s' directory\n", call->name);
1164                 return -1;
1165         }
1166
1167         if (call->class->reg)
1168                 trace_create_file("enable", 0644, call->dir, call,
1169                                   enable);
1170
1171 #ifdef CONFIG_PERF_EVENTS
1172         if (call->event.type && call->class->reg)
1173                 trace_create_file("id", 0444, call->dir, call,
1174                                   id);
1175 #endif
1176
1177         /*
1178          * Other events may have the same class. Only update
1179          * the fields if they are not already defined.
1180          */
1181         head = trace_get_fields(call);
1182         if (list_empty(head)) {
1183                 ret = call->class->define_fields(call);
1184                 if (ret < 0) {
1185                         pr_warning("Could not initialize trace point"
1186                                    " events/%s\n", call->name);
1187                         return ret;
1188                 }
1189         }
1190         trace_create_file("filter", 0644, call->dir, call,
1191                           filter);
1192
1193         trace_create_file("format", 0444, call->dir, call,
1194                           format);
1195
1196         return 0;
1197 }
1198
1199 static int
1200 __trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
1201                        const struct file_operations *id,
1202                        const struct file_operations *enable,
1203                        const struct file_operations *filter,
1204                        const struct file_operations *format)
1205 {
1206         struct dentry *d_events;
1207         int ret;
1208
1209         /* The linker may leave blanks */
1210         if (!call->name)
1211                 return -EINVAL;
1212
1213         if (call->class->raw_init) {
1214                 ret = call->class->raw_init(call);
1215                 if (ret < 0) {
1216                         if (ret != -ENOSYS)
1217                                 pr_warning("Could not initialize trace events/%s\n",
1218                                            call->name);
1219                         return ret;
1220                 }
1221         }
1222
1223         d_events = event_trace_events_dir();
1224         if (!d_events)
1225                 return -ENOENT;
1226
1227         ret = event_create_dir(call, d_events, id, enable, filter, format);
1228         if (!ret)
1229                 list_add(&call->list, &ftrace_events);
1230         call->mod = mod;
1231
1232         return ret;
1233 }
1234
1235 /* Add an additional event_call dynamically */
1236 int trace_add_event_call(struct ftrace_event_call *call)
1237 {
1238         int ret;
1239         mutex_lock(&event_mutex);
1240         ret = __trace_add_event_call(call, NULL, &ftrace_event_id_fops,
1241                                      &ftrace_enable_fops,
1242                                      &ftrace_event_filter_fops,
1243                                      &ftrace_event_format_fops);
1244         mutex_unlock(&event_mutex);
1245         return ret;
1246 }
1247
1248 static void remove_subsystem_dir(const char *name)
1249 {
1250         struct event_subsystem *system;
1251
1252         if (strcmp(name, TRACE_SYSTEM) == 0)
1253                 return;
1254
1255         list_for_each_entry(system, &event_subsystems, list) {
1256                 if (strcmp(system->name, name) == 0) {
1257                         if (!--system->nr_events) {
1258                                 debugfs_remove_recursive(system->entry);
1259                                 list_del(&system->list);
1260                                 __put_system(system);
1261                         }
1262                         break;
1263                 }
1264         }
1265 }
1266
1267 /*
1268  * Must be called under locking both of event_mutex and trace_event_mutex.
1269  */
1270 static void __trace_remove_event_call(struct ftrace_event_call *call)
1271 {
1272         ftrace_event_enable_disable(call, 0);
1273         if (call->event.funcs)
1274                 __unregister_ftrace_event(&call->event);
1275         debugfs_remove_recursive(call->dir);
1276         list_del(&call->list);
1277         trace_destroy_fields(call);
1278         destroy_preds(call);
1279         remove_subsystem_dir(call->class->system);
1280 }
1281
1282 /* Remove an event_call */
1283 void trace_remove_event_call(struct ftrace_event_call *call)
1284 {
1285         mutex_lock(&event_mutex);
1286         down_write(&trace_event_mutex);
1287         __trace_remove_event_call(call);
1288         up_write(&trace_event_mutex);
1289         mutex_unlock(&event_mutex);
1290 }
1291
1292 #define for_each_event(event, start, end)                       \
1293         for (event = start;                                     \
1294              (unsigned long)event < (unsigned long)end;         \
1295              event++)
1296
1297 #ifdef CONFIG_MODULES
1298
1299 static LIST_HEAD(ftrace_module_file_list);
1300
1301 /*
1302  * Modules must own their file_operations to keep up with
1303  * reference counting.
1304  */
1305 struct ftrace_module_file_ops {
1306         struct list_head                list;
1307         struct module                   *mod;
1308         struct file_operations          id;
1309         struct file_operations          enable;
1310         struct file_operations          format;
1311         struct file_operations          filter;
1312 };
1313
1314 static struct ftrace_module_file_ops *
1315 trace_create_file_ops(struct module *mod)
1316 {
1317         struct ftrace_module_file_ops *file_ops;
1318
1319         /*
1320          * This is a bit of a PITA. To allow for correct reference
1321          * counting, modules must "own" their file_operations.
1322          * To do this, we allocate the file operations that will be
1323          * used in the event directory.
1324          */
1325
1326         file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1327         if (!file_ops)
1328                 return NULL;
1329
1330         file_ops->mod = mod;
1331
1332         file_ops->id = ftrace_event_id_fops;
1333         file_ops->id.owner = mod;
1334
1335         file_ops->enable = ftrace_enable_fops;
1336         file_ops->enable.owner = mod;
1337
1338         file_ops->filter = ftrace_event_filter_fops;
1339         file_ops->filter.owner = mod;
1340
1341         file_ops->format = ftrace_event_format_fops;
1342         file_ops->format.owner = mod;
1343
1344         list_add(&file_ops->list, &ftrace_module_file_list);
1345
1346         return file_ops;
1347 }
1348
1349 static void trace_module_add_events(struct module *mod)
1350 {
1351         struct ftrace_module_file_ops *file_ops = NULL;
1352         struct ftrace_event_call **call, **start, **end;
1353
1354         start = mod->trace_events;
1355         end = mod->trace_events + mod->num_trace_events;
1356
1357         if (start == end)
1358                 return;
1359
1360         file_ops = trace_create_file_ops(mod);
1361         if (!file_ops)
1362                 return;
1363
1364         for_each_event(call, start, end) {
1365                 __trace_add_event_call(*call, mod,
1366                                        &file_ops->id, &file_ops->enable,
1367                                        &file_ops->filter, &file_ops->format);
1368         }
1369 }
1370
1371 static void trace_module_remove_events(struct module *mod)
1372 {
1373         struct ftrace_module_file_ops *file_ops;
1374         struct ftrace_event_call *call, *p;
1375         bool found = false;
1376
1377         down_write(&trace_event_mutex);
1378         list_for_each_entry_safe(call, p, &ftrace_events, list) {
1379                 if (call->mod == mod) {
1380                         found = true;
1381                         __trace_remove_event_call(call);
1382                 }
1383         }
1384
1385         /* Now free the file_operations */
1386         list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1387                 if (file_ops->mod == mod)
1388                         break;
1389         }
1390         if (&file_ops->list != &ftrace_module_file_list) {
1391                 list_del(&file_ops->list);
1392                 kfree(file_ops);
1393         }
1394
1395         /*
1396          * It is safest to reset the ring buffer if the module being unloaded
1397          * registered any events.
1398          */
1399         if (found)
1400                 tracing_reset_current_online_cpus();
1401         up_write(&trace_event_mutex);
1402 }
1403
1404 static int trace_module_notify(struct notifier_block *self,
1405                                unsigned long val, void *data)
1406 {
1407         struct module *mod = data;
1408
1409         mutex_lock(&event_mutex);
1410         switch (val) {
1411         case MODULE_STATE_COMING:
1412                 trace_module_add_events(mod);
1413                 break;
1414         case MODULE_STATE_GOING:
1415                 trace_module_remove_events(mod);
1416                 break;
1417         }
1418         mutex_unlock(&event_mutex);
1419
1420         return 0;
1421 }
1422 #else
1423 static int trace_module_notify(struct notifier_block *self,
1424                                unsigned long val, void *data)
1425 {
1426         return 0;
1427 }
1428 #endif /* CONFIG_MODULES */
1429
1430 static struct notifier_block trace_module_nb = {
1431         .notifier_call = trace_module_notify,
1432         .priority = 0,
1433 };
1434
1435 extern struct ftrace_event_call *__start_ftrace_events[];
1436 extern struct ftrace_event_call *__stop_ftrace_events[];
1437
1438 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1439
1440 static __init int setup_trace_event(char *str)
1441 {
1442         strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1443         ring_buffer_expanded = 1;
1444         tracing_selftest_disabled = 1;
1445
1446         return 1;
1447 }
1448 __setup("trace_event=", setup_trace_event);
1449
1450 static __init int event_trace_init(void)
1451 {
1452         struct ftrace_event_call **call;
1453         struct dentry *d_tracer;
1454         struct dentry *entry;
1455         struct dentry *d_events;
1456         int ret;
1457         char *buf = bootup_event_buf;
1458         char *token;
1459
1460         d_tracer = tracing_init_dentry();
1461         if (!d_tracer)
1462                 return 0;
1463
1464         entry = debugfs_create_file("available_events", 0444, d_tracer,
1465                                     (void *)&show_event_seq_ops,
1466                                     &ftrace_avail_fops);
1467         if (!entry)
1468                 pr_warning("Could not create debugfs "
1469                            "'available_events' entry\n");
1470
1471         entry = debugfs_create_file("set_event", 0644, d_tracer,
1472                                     (void *)&show_set_event_seq_ops,
1473                                     &ftrace_set_event_fops);
1474         if (!entry)
1475                 pr_warning("Could not create debugfs "
1476                            "'set_event' entry\n");
1477
1478         d_events = event_trace_events_dir();
1479         if (!d_events)
1480                 return 0;
1481
1482         /* ring buffer internal formats */
1483         trace_create_file("header_page", 0444, d_events,
1484                           ring_buffer_print_page_header,
1485                           &ftrace_show_header_fops);
1486
1487         trace_create_file("header_event", 0444, d_events,
1488                           ring_buffer_print_entry_header,
1489                           &ftrace_show_header_fops);
1490
1491         trace_create_file("enable", 0644, d_events,
1492                           NULL, &ftrace_system_enable_fops);
1493
1494         if (trace_define_common_fields())
1495                 pr_warning("tracing: Failed to allocate common fields");
1496
1497         for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
1498                 __trace_add_event_call(*call, NULL, &ftrace_event_id_fops,
1499                                        &ftrace_enable_fops,
1500                                        &ftrace_event_filter_fops,
1501                                        &ftrace_event_format_fops);
1502         }
1503
1504         while (true) {
1505                 token = strsep(&buf, ",");
1506
1507                 if (!token)
1508                         break;
1509                 if (!*token)
1510                         continue;
1511
1512                 ret = ftrace_set_clr_event(token, 1);
1513                 if (ret)
1514                         pr_warning("Failed to enable trace event: %s\n", token);
1515         }
1516
1517         ret = register_module_notifier(&trace_module_nb);
1518         if (ret)
1519                 pr_warning("Failed to register trace events module notifier\n");
1520
1521         return 0;
1522 }
1523 fs_initcall(event_trace_init);
1524
1525 #ifdef CONFIG_FTRACE_STARTUP_TEST
1526
1527 static DEFINE_SPINLOCK(test_spinlock);
1528 static DEFINE_SPINLOCK(test_spinlock_irq);
1529 static DEFINE_MUTEX(test_mutex);
1530
1531 static __init void test_work(struct work_struct *dummy)
1532 {
1533         spin_lock(&test_spinlock);
1534         spin_lock_irq(&test_spinlock_irq);
1535         udelay(1);
1536         spin_unlock_irq(&test_spinlock_irq);
1537         spin_unlock(&test_spinlock);
1538
1539         mutex_lock(&test_mutex);
1540         msleep(1);
1541         mutex_unlock(&test_mutex);
1542 }
1543
1544 static __init int event_test_thread(void *unused)
1545 {
1546         void *test_malloc;
1547
1548         test_malloc = kmalloc(1234, GFP_KERNEL);
1549         if (!test_malloc)
1550                 pr_info("failed to kmalloc\n");
1551
1552         schedule_on_each_cpu(test_work);
1553
1554         kfree(test_malloc);
1555
1556         set_current_state(TASK_INTERRUPTIBLE);
1557         while (!kthread_should_stop())
1558                 schedule();
1559
1560         return 0;
1561 }
1562
1563 /*
1564  * Do various things that may trigger events.
1565  */
1566 static __init void event_test_stuff(void)
1567 {
1568         struct task_struct *test_thread;
1569
1570         test_thread = kthread_run(event_test_thread, NULL, "test-events");
1571         msleep(1);
1572         kthread_stop(test_thread);
1573 }
1574
1575 /*
1576  * For every trace event defined, we will test each trace point separately,
1577  * and then by groups, and finally all trace points.
1578  */
1579 static __init void event_trace_self_tests(void)
1580 {
1581         struct ftrace_event_call *call;
1582         struct event_subsystem *system;
1583         int ret;
1584
1585         pr_info("Running tests on trace events:\n");
1586
1587         list_for_each_entry(call, &ftrace_events, list) {
1588
1589                 /* Only test those that have a probe */
1590                 if (!call->class || !call->class->probe)
1591                         continue;
1592
1593 /*
1594  * Testing syscall events here is pretty useless, but
1595  * we still do it if configured. But this is time consuming.
1596  * What we really need is a user thread to perform the
1597  * syscalls as we test.
1598  */
1599 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1600                 if (call->class->system &&
1601                     strcmp(call->class->system, "syscalls") == 0)
1602                         continue;
1603 #endif
1604
1605                 pr_info("Testing event %s: ", call->name);
1606
1607                 /*
1608                  * If an event is already enabled, someone is using
1609                  * it and the self test should not be on.
1610                  */
1611                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
1612                         pr_warning("Enabled event during self test!\n");
1613                         WARN_ON_ONCE(1);
1614                         continue;
1615                 }
1616
1617                 ftrace_event_enable_disable(call, 1);
1618                 event_test_stuff();
1619                 ftrace_event_enable_disable(call, 0);
1620
1621                 pr_cont("OK\n");
1622         }
1623
1624         /* Now test at the sub system level */
1625
1626         pr_info("Running tests on trace event systems:\n");
1627
1628         list_for_each_entry(system, &event_subsystems, list) {
1629
1630                 /* the ftrace system is special, skip it */
1631                 if (strcmp(system->name, "ftrace") == 0)
1632                         continue;
1633
1634                 pr_info("Testing event system %s: ", system->name);
1635
1636                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1637                 if (WARN_ON_ONCE(ret)) {
1638                         pr_warning("error enabling system %s\n",
1639                                    system->name);
1640                         continue;
1641                 }
1642
1643                 event_test_stuff();
1644
1645                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1646                 if (WARN_ON_ONCE(ret))
1647                         pr_warning("error disabling system %s\n",
1648                                    system->name);
1649
1650                 pr_cont("OK\n");
1651         }
1652
1653         /* Test with all events enabled */
1654
1655         pr_info("Running tests on all trace events:\n");
1656         pr_info("Testing all events: ");
1657
1658         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1659         if (WARN_ON_ONCE(ret)) {
1660                 pr_warning("error enabling all events\n");
1661                 return;
1662         }
1663
1664         event_test_stuff();
1665
1666         /* reset sysname */
1667         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1668         if (WARN_ON_ONCE(ret)) {
1669                 pr_warning("error disabling all events\n");
1670                 return;
1671         }
1672
1673         pr_cont("OK\n");
1674 }
1675
1676 #ifdef CONFIG_FUNCTION_TRACER
1677
1678 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1679
1680 static void
1681 function_test_events_call(unsigned long ip, unsigned long parent_ip)
1682 {
1683         struct ring_buffer_event *event;
1684         struct ring_buffer *buffer;
1685         struct ftrace_entry *entry;
1686         unsigned long flags;
1687         long disabled;
1688         int cpu;
1689         int pc;
1690
1691         pc = preempt_count();
1692         preempt_disable_notrace();
1693         cpu = raw_smp_processor_id();
1694         disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1695
1696         if (disabled != 1)
1697                 goto out;
1698
1699         local_save_flags(flags);
1700
1701         event = trace_current_buffer_lock_reserve(&buffer,
1702                                                   TRACE_FN, sizeof(*entry),
1703                                                   flags, pc);
1704         if (!event)
1705                 goto out;
1706         entry   = ring_buffer_event_data(event);
1707         entry->ip                       = ip;
1708         entry->parent_ip                = parent_ip;
1709
1710         trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
1711
1712  out:
1713         atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1714         preempt_enable_notrace();
1715 }
1716
1717 static struct ftrace_ops trace_ops __initdata  =
1718 {
1719         .func = function_test_events_call,
1720 };
1721
1722 static __init void event_trace_self_test_with_function(void)
1723 {
1724         int ret;
1725         ret = register_ftrace_function(&trace_ops);
1726         if (WARN_ON(ret < 0)) {
1727                 pr_info("Failed to enable function tracer for event tests\n");
1728                 return;
1729         }
1730         pr_info("Running tests again, along with the function tracer\n");
1731         event_trace_self_tests();
1732         unregister_ftrace_function(&trace_ops);
1733 }
1734 #else
1735 static __init void event_trace_self_test_with_function(void)
1736 {
1737 }
1738 #endif
1739
1740 static __init int event_trace_self_tests_init(void)
1741 {
1742         if (!tracing_selftest_disabled) {
1743                 event_trace_self_tests();
1744                 event_trace_self_test_with_function();
1745         }
1746
1747         return 0;
1748 }
1749
1750 late_initcall(event_trace_self_tests_init);
1751
1752 #endif