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net: Fix non-kernel-doc comments with kernel-doc start marker
[linux-2.6.git] / kernel / trace / trace_events.c
blob29111da1d1006c1f7b57a939b54517d17f315520
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 (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
298 continue;
299
300 if (match &&
301 strcmp(match, call->name) != 0 &&
302 strcmp(match, call->class->system) != 0)
303 continue;
304
305 if (sub && strcmp(sub, call->class->system) != 0)
306 continue;
307
308 if (event && strcmp(event, call->name) != 0)
309 continue;
310
311 ftrace_event_enable_disable(call, set);
312
313 ret = 0;
314 }
315 mutex_unlock(&event_mutex);
316
317 return ret;
318 }
319
320 static int ftrace_set_clr_event(char *buf, int set)
321 {
322 char *event = NULL, *sub = NULL, *match;
323
324 /*
325 * The buf format can be <subsystem>:<event-name>
326 * *:<event-name> means any event by that name.
327 * :<event-name> is the same.
328 *
329 * <subsystem>:* means all events in that subsystem
330 * <subsystem>: means the same.
331 *
332 * <name> (no ':') means all events in a subsystem with
333 * the name <name> or any event that matches <name>
334 */
335
336 match = strsep(&buf, ":");
337 if (buf) {
338 sub = match;
339 event = buf;
340 match = NULL;
341
342 if (!strlen(sub) || strcmp(sub, "*") == 0)
343 sub = NULL;
344 if (!strlen(event) || strcmp(event, "*") == 0)
345 event = NULL;
346 }
347
348 return __ftrace_set_clr_event(match, sub, event, set);
349 }
350
351 /**
352 * trace_set_clr_event - enable or disable an event
353 * @system: system name to match (NULL for any system)
354 * @event: event name to match (NULL for all events, within system)
355 * @set: 1 to enable, 0 to disable
356 *
357 * This is a way for other parts of the kernel to enable or disable
358 * event recording.
359 *
360 * Returns 0 on success, -EINVAL if the parameters do not match any
361 * registered events.
362 */
363 int trace_set_clr_event(const char *system, const char *event, int set)
364 {
365 return __ftrace_set_clr_event(NULL, system, event, set);
366 }
367 EXPORT_SYMBOL_GPL(trace_set_clr_event);
368
369 /* 128 should be much more than enough */
370 #define EVENT_BUF_SIZE 127
371
372 static ssize_t
373 ftrace_event_write(struct file *file, const char __user *ubuf,
374 size_t cnt, loff_t *ppos)
375 {
376 struct trace_parser parser;
377 ssize_t read, ret;
378
379 if (!cnt)
380 return 0;
381
382 ret = tracing_update_buffers();
383 if (ret < 0)
384 return ret;
385
386 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
387 return -ENOMEM;
388
389 read = trace_get_user(&parser, ubuf, cnt, ppos);
390
391 if (read >= 0 && trace_parser_loaded((&parser))) {
392 int set = 1;
393
394 if (*parser.buffer == '!')
395 set = 0;
396
397 parser.buffer[parser.idx] = 0;
398
399 ret = ftrace_set_clr_event(parser.buffer + !set, set);
400 if (ret)
401 goto out_put;
402 }
403
404 ret = read;
405
406 out_put:
407 trace_parser_put(&parser);
408
409 return ret;
410 }
411
412 static void *
413 t_next(struct seq_file *m, void *v, loff_t *pos)
414 {
415 struct ftrace_event_call *call = v;
416
417 (*pos)++;
418
419 list_for_each_entry_continue(call, &ftrace_events, list) {
420 /*
421 * The ftrace subsystem is for showing formats only.
422 * They can not be enabled or disabled via the event files.
423 */
424 if (call->class && call->class->reg)
425 return call;
426 }
427
428 return NULL;
429 }
430
431 static void *t_start(struct seq_file *m, loff_t *pos)
432 {
433 struct ftrace_event_call *call;
434 loff_t l;
435
436 mutex_lock(&event_mutex);
437
438 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
439 for (l = 0; l <= *pos; ) {
440 call = t_next(m, call, &l);
441 if (!call)
442 break;
443 }
444 return call;
445 }
446
447 static void *
448 s_next(struct seq_file *m, void *v, loff_t *pos)
449 {
450 struct ftrace_event_call *call = v;
451
452 (*pos)++;
453
454 list_for_each_entry_continue(call, &ftrace_events, list) {
455 if (call->flags & TRACE_EVENT_FL_ENABLED)
456 return call;
457 }
458
459 return NULL;
460 }
461
462 static void *s_start(struct seq_file *m, loff_t *pos)
463 {
464 struct ftrace_event_call *call;
465 loff_t l;
466
467 mutex_lock(&event_mutex);
468
469 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
470 for (l = 0; l <= *pos; ) {
471 call = s_next(m, call, &l);
472 if (!call)
473 break;
474 }
475 return call;
476 }
477
478 static int t_show(struct seq_file *m, void *v)
479 {
480 struct ftrace_event_call *call = v;
481
482 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
483 seq_printf(m, "%s:", call->class->system);
484 seq_printf(m, "%s\n", call->name);
485
486 return 0;
487 }
488
489 static void t_stop(struct seq_file *m, void *p)
490 {
491 mutex_unlock(&event_mutex);
492 }
493
494 static int
495 ftrace_event_seq_open(struct inode *inode, struct file *file)
496 {
497 const struct seq_operations *seq_ops;
498
499 if ((file->f_mode & FMODE_WRITE) &&
500 (file->f_flags & O_TRUNC))
501 ftrace_clear_events();
502
503 seq_ops = inode->i_private;
504 return seq_open(file, seq_ops);
505 }
506
507 static ssize_t
508 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
509 loff_t *ppos)
510 {
511 struct ftrace_event_call *call = filp->private_data;
512 char *buf;
513
514 if (call->flags & TRACE_EVENT_FL_ENABLED)
515 buf = "1\n";
516 else
517 buf = "0\n";
518
519 return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
520 }
521
522 static ssize_t
523 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
524 loff_t *ppos)
525 {
526 struct ftrace_event_call *call = filp->private_data;
527 unsigned long val;
528 int ret;
529
530 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
531 if (ret)
532 return ret;
533
534 ret = tracing_update_buffers();
535 if (ret < 0)
536 return ret;
537
538 switch (val) {
539 case 0:
540 case 1:
541 mutex_lock(&event_mutex);
542 ret = ftrace_event_enable_disable(call, val);
543 mutex_unlock(&event_mutex);
544 break;
545
546 default:
547 return -EINVAL;
548 }
549
550 *ppos += cnt;
551
552 return ret ? ret : cnt;
553 }
554
555 static ssize_t
556 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
557 loff_t *ppos)
558 {
559 const char set_to_char[4] = { '?', '0', '1', 'X' };
560 struct event_subsystem *system = filp->private_data;
561 struct ftrace_event_call *call;
562 char buf[2];
563 int set = 0;
564 int ret;
565
566 mutex_lock(&event_mutex);
567 list_for_each_entry(call, &ftrace_events, list) {
568 if (!call->name || !call->class || !call->class->reg)
569 continue;
570
571 if (system && strcmp(call->class->system, system->name) != 0)
572 continue;
573
574 /*
575 * We need to find out if all the events are set
576 * or if all events or cleared, or if we have
577 * a mixture.
578 */
579 set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED));
580
581 /*
582 * If we have a mixture, no need to look further.
583 */
584 if (set == 3)
585 break;
586 }
587 mutex_unlock(&event_mutex);
588
589 buf[0] = set_to_char[set];
590 buf[1] = '\n';
591
592 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
593
594 return ret;
595 }
596
597 static ssize_t
598 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
599 loff_t *ppos)
600 {
601 struct event_subsystem *system = filp->private_data;
602 const char *name = NULL;
603 unsigned long val;
604 ssize_t ret;
605
606 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
607 if (ret)
608 return ret;
609
610 ret = tracing_update_buffers();
611 if (ret < 0)
612 return ret;
613
614 if (val != 0 && val != 1)
615 return -EINVAL;
616
617 /*
618 * Opening of "enable" adds a ref count to system,
619 * so the name is safe to use.
620 */
621 if (system)
622 name = system->name;
623
624 ret = __ftrace_set_clr_event(NULL, name, NULL, val);
625 if (ret)
626 goto out;
627
628 ret = cnt;
629
630 out:
631 *ppos += cnt;
632
633 return ret;
634 }
635
636 enum {
637 FORMAT_HEADER = 1,
638 FORMAT_FIELD_SEPERATOR = 2,
639 FORMAT_PRINTFMT = 3,
640 };
641
642 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
643 {
644 struct ftrace_event_call *call = m->private;
645 struct ftrace_event_field *field;
646 struct list_head *common_head = &ftrace_common_fields;
647 struct list_head *head = trace_get_fields(call);
648
649 (*pos)++;
650
651 switch ((unsigned long)v) {
652 case FORMAT_HEADER:
653 if (unlikely(list_empty(common_head)))
654 return NULL;
655
656 field = list_entry(common_head->prev,
657 struct ftrace_event_field, link);
658 return field;
659
660 case FORMAT_FIELD_SEPERATOR:
661 if (unlikely(list_empty(head)))
662 return NULL;
663
664 field = list_entry(head->prev, struct ftrace_event_field, link);
665 return field;
666
667 case FORMAT_PRINTFMT:
668 /* all done */
669 return NULL;
670 }
671
672 field = v;
673 if (field->link.prev == common_head)
674 return (void *)FORMAT_FIELD_SEPERATOR;
675 else if (field->link.prev == head)
676 return (void *)FORMAT_PRINTFMT;
677
678 field = list_entry(field->link.prev, struct ftrace_event_field, link);
679
680 return field;
681 }
682
683 static void *f_start(struct seq_file *m, loff_t *pos)
684 {
685 loff_t l = 0;
686 void *p;
687
688 /* Start by showing the header */
689 if (!*pos)
690 return (void *)FORMAT_HEADER;
691
692 p = (void *)FORMAT_HEADER;
693 do {
694 p = f_next(m, p, &l);
695 } while (p && l < *pos);
696
697 return p;
698 }
699
700 static int f_show(struct seq_file *m, void *v)
701 {
702 struct ftrace_event_call *call = m->private;
703 struct ftrace_event_field *field;
704 const char *array_descriptor;
705
706 switch ((unsigned long)v) {
707 case FORMAT_HEADER:
708 seq_printf(m, "name: %s\n", call->name);
709 seq_printf(m, "ID: %d\n", call->event.type);
710 seq_printf(m, "format:\n");
711 return 0;
712
713 case FORMAT_FIELD_SEPERATOR:
714 seq_putc(m, '\n');
715 return 0;
716
717 case FORMAT_PRINTFMT:
718 seq_printf(m, "\nprint fmt: %s\n",
719 call->print_fmt);
720 return 0;
721 }
722
723 field = v;
724
725 /*
726 * Smartly shows the array type(except dynamic array).
727 * Normal:
728 * field:TYPE VAR
729 * If TYPE := TYPE[LEN], it is shown:
730 * field:TYPE VAR[LEN]
731 */
732 array_descriptor = strchr(field->type, '[');
733
734 if (!strncmp(field->type, "__data_loc", 10))
735 array_descriptor = NULL;
736
737 if (!array_descriptor)
738 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
739 field->type, field->name, field->offset,
740 field->size, !!field->is_signed);
741 else
742 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
743 (int)(array_descriptor - field->type),
744 field->type, field->name,
745 array_descriptor, field->offset,
746 field->size, !!field->is_signed);
747
748 return 0;
749 }
750
751 static void f_stop(struct seq_file *m, void *p)
752 {
753 }
754
755 static const struct seq_operations trace_format_seq_ops = {
756 .start = f_start,
757 .next = f_next,
758 .stop = f_stop,
759 .show = f_show,
760 };
761
762 static int trace_format_open(struct inode *inode, struct file *file)
763 {
764 struct ftrace_event_call *call = inode->i_private;
765 struct seq_file *m;
766 int ret;
767
768 ret = seq_open(file, &trace_format_seq_ops);
769 if (ret < 0)
770 return ret;
771
772 m = file->private_data;
773 m->private = call;
774
775 return 0;
776 }
777
778 static ssize_t
779 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
780 {
781 struct ftrace_event_call *call = filp->private_data;
782 struct trace_seq *s;
783 int r;
784
785 if (*ppos)
786 return 0;
787
788 s = kmalloc(sizeof(*s), GFP_KERNEL);
789 if (!s)
790 return -ENOMEM;
791
792 trace_seq_init(s);
793 trace_seq_printf(s, "%d\n", call->event.type);
794
795 r = simple_read_from_buffer(ubuf, cnt, ppos,
796 s->buffer, s->len);
797 kfree(s);
798 return r;
799 }
800
801 static ssize_t
802 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
803 loff_t *ppos)
804 {
805 struct ftrace_event_call *call = filp->private_data;
806 struct trace_seq *s;
807 int r;
808
809 if (*ppos)
810 return 0;
811
812 s = kmalloc(sizeof(*s), GFP_KERNEL);
813 if (!s)
814 return -ENOMEM;
815
816 trace_seq_init(s);
817
818 print_event_filter(call, s);
819 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
820
821 kfree(s);
822
823 return r;
824 }
825
826 static ssize_t
827 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
828 loff_t *ppos)
829 {
830 struct ftrace_event_call *call = filp->private_data;
831 char *buf;
832 int err;
833
834 if (cnt >= PAGE_SIZE)
835 return -EINVAL;
836
837 buf = (char *)__get_free_page(GFP_TEMPORARY);
838 if (!buf)
839 return -ENOMEM;
840
841 if (copy_from_user(buf, ubuf, cnt)) {
842 free_page((unsigned long) buf);
843 return -EFAULT;
844 }
845 buf[cnt] = '\0';
846
847 err = apply_event_filter(call, buf);
848 free_page((unsigned long) buf);
849 if (err < 0)
850 return err;
851
852 *ppos += cnt;
853
854 return cnt;
855 }
856
857 static LIST_HEAD(event_subsystems);
858
859 static int subsystem_open(struct inode *inode, struct file *filp)
860 {
861 struct event_subsystem *system = NULL;
862 int ret;
863
864 if (!inode->i_private)
865 goto skip_search;
866
867 /* Make sure the system still exists */
868 mutex_lock(&event_mutex);
869 list_for_each_entry(system, &event_subsystems, list) {
870 if (system == inode->i_private) {
871 /* Don't open systems with no events */
872 if (!system->nr_events) {
873 system = NULL;
874 break;
875 }
876 __get_system(system);
877 break;
878 }
879 }
880 mutex_unlock(&event_mutex);
881
882 if (system != inode->i_private)
883 return -ENODEV;
884
885 skip_search:
886 ret = tracing_open_generic(inode, filp);
887 if (ret < 0 && system)
888 put_system(system);
889
890 return ret;
891 }
892
893 static int subsystem_release(struct inode *inode, struct file *file)
894 {
895 struct event_subsystem *system = inode->i_private;
896
897 if (system)
898 put_system(system);
899
900 return 0;
901 }
902
903 static ssize_t
904 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
905 loff_t *ppos)
906 {
907 struct event_subsystem *system = filp->private_data;
908 struct trace_seq *s;
909 int r;
910
911 if (*ppos)
912 return 0;
913
914 s = kmalloc(sizeof(*s), GFP_KERNEL);
915 if (!s)
916 return -ENOMEM;
917
918 trace_seq_init(s);
919
920 print_subsystem_event_filter(system, s);
921 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
922
923 kfree(s);
924
925 return r;
926 }
927
928 static ssize_t
929 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
930 loff_t *ppos)
931 {
932 struct event_subsystem *system = filp->private_data;
933 char *buf;
934 int err;
935
936 if (cnt >= PAGE_SIZE)
937 return -EINVAL;
938
939 buf = (char *)__get_free_page(GFP_TEMPORARY);
940 if (!buf)
941 return -ENOMEM;
942
943 if (copy_from_user(buf, ubuf, cnt)) {
944 free_page((unsigned long) buf);
945 return -EFAULT;
946 }
947 buf[cnt] = '\0';
948
949 err = apply_subsystem_event_filter(system, buf);
950 free_page((unsigned long) buf);
951 if (err < 0)
952 return err;
953
954 *ppos += cnt;
955
956 return cnt;
957 }
958
959 static ssize_t
960 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
961 {
962 int (*func)(struct trace_seq *s) = filp->private_data;
963 struct trace_seq *s;
964 int r;
965
966 if (*ppos)
967 return 0;
968
969 s = kmalloc(sizeof(*s), GFP_KERNEL);
970 if (!s)
971 return -ENOMEM;
972
973 trace_seq_init(s);
974
975 func(s);
976 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
977
978 kfree(s);
979
980 return r;
981 }
982
983 static const struct seq_operations show_event_seq_ops = {
984 .start = t_start,
985 .next = t_next,
986 .show = t_show,
987 .stop = t_stop,
988 };
989
990 static const struct seq_operations show_set_event_seq_ops = {
991 .start = s_start,
992 .next = s_next,
993 .show = t_show,
994 .stop = t_stop,
995 };
996
997 static const struct file_operations ftrace_avail_fops = {
998 .open = ftrace_event_seq_open,
999 .read = seq_read,
1000 .llseek = seq_lseek,
1001 .release = seq_release,
1002 };
1003
1004 static const struct file_operations ftrace_set_event_fops = {
1005 .open = ftrace_event_seq_open,
1006 .read = seq_read,
1007 .write = ftrace_event_write,
1008 .llseek = seq_lseek,
1009 .release = seq_release,
1010 };
1011
1012 static const struct file_operations ftrace_enable_fops = {
1013 .open = tracing_open_generic,
1014 .read = event_enable_read,
1015 .write = event_enable_write,
1016 .llseek = default_llseek,
1017 };
1018
1019 static const struct file_operations ftrace_event_format_fops = {
1020 .open = trace_format_open,
1021 .read = seq_read,
1022 .llseek = seq_lseek,
1023 .release = seq_release,
1024 };
1025
1026 static const struct file_operations ftrace_event_id_fops = {
1027 .open = tracing_open_generic,
1028 .read = event_id_read,
1029 .llseek = default_llseek,
1030 };
1031
1032 static const struct file_operations ftrace_event_filter_fops = {
1033 .open = tracing_open_generic,
1034 .read = event_filter_read,
1035 .write = event_filter_write,
1036 .llseek = default_llseek,
1037 };
1038
1039 static const struct file_operations ftrace_subsystem_filter_fops = {
1040 .open = subsystem_open,
1041 .read = subsystem_filter_read,
1042 .write = subsystem_filter_write,
1043 .llseek = default_llseek,
1044 .release = subsystem_release,
1045 };
1046
1047 static const struct file_operations ftrace_system_enable_fops = {
1048 .open = subsystem_open,
1049 .read = system_enable_read,
1050 .write = system_enable_write,
1051 .llseek = default_llseek,
1052 .release = subsystem_release,
1053 };
1054
1055 static const struct file_operations ftrace_show_header_fops = {
1056 .open = tracing_open_generic,
1057 .read = show_header,
1058 .llseek = default_llseek,
1059 };
1060
1061 static struct dentry *event_trace_events_dir(void)
1062 {
1063 static struct dentry *d_tracer;
1064 static struct dentry *d_events;
1065
1066 if (d_events)
1067 return d_events;
1068
1069 d_tracer = tracing_init_dentry();
1070 if (!d_tracer)
1071 return NULL;
1072
1073 d_events = debugfs_create_dir("events", d_tracer);
1074 if (!d_events)
1075 pr_warning("Could not create debugfs "
1076 "'events' directory\n");
1077
1078 return d_events;
1079 }
1080
1081 static struct dentry *
1082 event_subsystem_dir(const char *name, struct dentry *d_events)
1083 {
1084 struct event_subsystem *system;
1085 struct dentry *entry;
1086
1087 /* First see if we did not already create this dir */
1088 list_for_each_entry(system, &event_subsystems, list) {
1089 if (strcmp(system->name, name) == 0) {
1090 system->nr_events++;
1091 return system->entry;
1092 }
1093 }
1094
1095 /* need to create new entry */
1096 system = kmalloc(sizeof(*system), GFP_KERNEL);
1097 if (!system) {
1098 pr_warning("No memory to create event subsystem %s\n",
1099 name);
1100 return d_events;
1101 }
1102
1103 system->entry = debugfs_create_dir(name, d_events);
1104 if (!system->entry) {
1105 pr_warning("Could not create event subsystem %s\n",
1106 name);
1107 kfree(system);
1108 return d_events;
1109 }
1110
1111 system->nr_events = 1;
1112 system->ref_count = 1;
1113 system->name = kstrdup(name, GFP_KERNEL);
1114 if (!system->name) {
1115 debugfs_remove(system->entry);
1116 kfree(system);
1117 return d_events;
1118 }
1119
1120 list_add(&system->list, &event_subsystems);
1121
1122 system->filter = NULL;
1123
1124 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1125 if (!system->filter) {
1126 pr_warning("Could not allocate filter for subsystem "
1127 "'%s'\n", name);
1128 return system->entry;
1129 }
1130
1131 entry = debugfs_create_file("filter", 0644, system->entry, system,
1132 &ftrace_subsystem_filter_fops);
1133 if (!entry) {
1134 kfree(system->filter);
1135 system->filter = NULL;
1136 pr_warning("Could not create debugfs "
1137 "'%s/filter' entry\n", name);
1138 }
1139
1140 trace_create_file("enable", 0644, system->entry, system,
1141 &ftrace_system_enable_fops);
1142
1143 return system->entry;
1144 }
1145
1146 static int
1147 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
1148 const struct file_operations *id,
1149 const struct file_operations *enable,
1150 const struct file_operations *filter,
1151 const struct file_operations *format)
1152 {
1153 struct list_head *head;
1154 int ret;
1155
1156 /*
1157 * If the trace point header did not define TRACE_SYSTEM
1158 * then the system would be called "TRACE_SYSTEM".
1159 */
1160 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1161 d_events = event_subsystem_dir(call->class->system, d_events);
1162
1163 call->dir = debugfs_create_dir(call->name, d_events);
1164 if (!call->dir) {
1165 pr_warning("Could not create debugfs "
1166 "'%s' directory\n", call->name);
1167 return -1;
1168 }
1169
1170 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1171 trace_create_file("enable", 0644, call->dir, call,
1172 enable);
1173
1174 #ifdef CONFIG_PERF_EVENTS
1175 if (call->event.type && call->class->reg)
1176 trace_create_file("id", 0444, call->dir, call,
1177 id);
1178 #endif
1179
1180 /*
1181 * Other events may have the same class. Only update
1182 * the fields if they are not already defined.
1183 */
1184 head = trace_get_fields(call);
1185 if (list_empty(head)) {
1186 ret = call->class->define_fields(call);
1187 if (ret < 0) {
1188 pr_warning("Could not initialize trace point"
1189 " events/%s\n", call->name);
1190 return ret;
1191 }
1192 }
1193 trace_create_file("filter", 0644, call->dir, call,
1194 filter);
1195
1196 trace_create_file("format", 0444, call->dir, call,
1197 format);
1198
1199 return 0;
1200 }
1201
1202 static int
1203 __trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
1204 const struct file_operations *id,
1205 const struct file_operations *enable,
1206 const struct file_operations *filter,
1207 const struct file_operations *format)
1208 {
1209 struct dentry *d_events;
1210 int ret;
1211
1212 /* The linker may leave blanks */
1213 if (!call->name)
1214 return -EINVAL;
1215
1216 if (call->class->raw_init) {
1217 ret = call->class->raw_init(call);
1218 if (ret < 0) {
1219 if (ret != -ENOSYS)
1220 pr_warning("Could not initialize trace events/%s\n",
1221 call->name);
1222 return ret;
1223 }
1224 }
1225
1226 d_events = event_trace_events_dir();
1227 if (!d_events)
1228 return -ENOENT;
1229
1230 ret = event_create_dir(call, d_events, id, enable, filter, format);
1231 if (!ret)
1232 list_add(&call->list, &ftrace_events);
1233 call->mod = mod;
1234
1235 return ret;
1236 }
1237
1238 /* Add an additional event_call dynamically */
1239 int trace_add_event_call(struct ftrace_event_call *call)
1240 {
1241 int ret;
1242 mutex_lock(&event_mutex);
1243 ret = __trace_add_event_call(call, NULL, &ftrace_event_id_fops,
1244 &ftrace_enable_fops,
1245 &ftrace_event_filter_fops,
1246 &ftrace_event_format_fops);
1247 mutex_unlock(&event_mutex);
1248 return ret;
1249 }
1250
1251 static void remove_subsystem_dir(const char *name)
1252 {
1253 struct event_subsystem *system;
1254
1255 if (strcmp(name, TRACE_SYSTEM) == 0)
1256 return;
1257
1258 list_for_each_entry(system, &event_subsystems, list) {
1259 if (strcmp(system->name, name) == 0) {
1260 if (!--system->nr_events) {
1261 debugfs_remove_recursive(system->entry);
1262 list_del(&system->list);
1263 __put_system(system);
1264 }
1265 break;
1266 }
1267 }
1268 }
1269
1270 /*
1271 * Must be called under locking both of event_mutex and trace_event_mutex.
1272 */
1273 static void __trace_remove_event_call(struct ftrace_event_call *call)
1274 {
1275 ftrace_event_enable_disable(call, 0);
1276 if (call->event.funcs)
1277 __unregister_ftrace_event(&call->event);
1278 debugfs_remove_recursive(call->dir);
1279 list_del(&call->list);
1280 trace_destroy_fields(call);
1281 destroy_preds(call);
1282 remove_subsystem_dir(call->class->system);
1283 }
1284
1285 /* Remove an event_call */
1286 void trace_remove_event_call(struct ftrace_event_call *call)
1287 {
1288 mutex_lock(&event_mutex);
1289 down_write(&trace_event_mutex);
1290 __trace_remove_event_call(call);
1291 up_write(&trace_event_mutex);
1292 mutex_unlock(&event_mutex);
1293 }
1294
1295 #define for_each_event(event, start, end) \
1296 for (event = start; \
1297 (unsigned long)event < (unsigned long)end; \
1298 event++)
1299
1300 #ifdef CONFIG_MODULES
1301
1302 static LIST_HEAD(ftrace_module_file_list);
1303
1304 /*
1305 * Modules must own their file_operations to keep up with
1306 * reference counting.
1307 */
1308 struct ftrace_module_file_ops {
1309 struct list_head list;
1310 struct module *mod;
1311 struct file_operations id;
1312 struct file_operations enable;
1313 struct file_operations format;
1314 struct file_operations filter;
1315 };
1316
1317 static struct ftrace_module_file_ops *
1318 trace_create_file_ops(struct module *mod)
1319 {
1320 struct ftrace_module_file_ops *file_ops;
1321
1322 /*
1323 * This is a bit of a PITA. To allow for correct reference
1324 * counting, modules must "own" their file_operations.
1325 * To do this, we allocate the file operations that will be
1326 * used in the event directory.
1327 */
1328
1329 file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1330 if (!file_ops)
1331 return NULL;
1332
1333 file_ops->mod = mod;
1334
1335 file_ops->id = ftrace_event_id_fops;
1336 file_ops->id.owner = mod;
1337
1338 file_ops->enable = ftrace_enable_fops;
1339 file_ops->enable.owner = mod;
1340
1341 file_ops->filter = ftrace_event_filter_fops;
1342 file_ops->filter.owner = mod;
1343
1344 file_ops->format = ftrace_event_format_fops;
1345 file_ops->format.owner = mod;
1346
1347 list_add(&file_ops->list, &ftrace_module_file_list);
1348
1349 return file_ops;
1350 }
1351
1352 static void trace_module_add_events(struct module *mod)
1353 {
1354 struct ftrace_module_file_ops *file_ops = NULL;
1355 struct ftrace_event_call **call, **start, **end;
1356
1357 start = mod->trace_events;
1358 end = mod->trace_events + mod->num_trace_events;
1359
1360 if (start == end)
1361 return;
1362
1363 file_ops = trace_create_file_ops(mod);
1364 if (!file_ops)
1365 return;
1366
1367 for_each_event(call, start, end) {
1368 __trace_add_event_call(*call, mod,
1369 &file_ops->id, &file_ops->enable,
1370 &file_ops->filter, &file_ops->format);
1371 }
1372 }
1373
1374 static void trace_module_remove_events(struct module *mod)
1375 {
1376 struct ftrace_module_file_ops *file_ops;
1377 struct ftrace_event_call *call, *p;
1378 bool found = false;
1379
1380 down_write(&trace_event_mutex);
1381 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1382 if (call->mod == mod) {
1383 found = true;
1384 __trace_remove_event_call(call);
1385 }
1386 }
1387
1388 /* Now free the file_operations */
1389 list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1390 if (file_ops->mod == mod)
1391 break;
1392 }
1393 if (&file_ops->list != &ftrace_module_file_list) {
1394 list_del(&file_ops->list);
1395 kfree(file_ops);
1396 }
1397
1398 /*
1399 * It is safest to reset the ring buffer if the module being unloaded
1400 * registered any events.
1401 */
1402 if (found)
1403 tracing_reset_current_online_cpus();
1404 up_write(&trace_event_mutex);
1405 }
1406
1407 static int trace_module_notify(struct notifier_block *self,
1408 unsigned long val, void *data)
1409 {
1410 struct module *mod = data;
1411
1412 mutex_lock(&event_mutex);
1413 switch (val) {
1414 case MODULE_STATE_COMING:
1415 trace_module_add_events(mod);
1416 break;
1417 case MODULE_STATE_GOING:
1418 trace_module_remove_events(mod);
1419 break;
1420 }
1421 mutex_unlock(&event_mutex);
1422
1423 return 0;
1424 }
1425 #else
1426 static int trace_module_notify(struct notifier_block *self,
1427 unsigned long val, void *data)
1428 {
1429 return 0;
1430 }
1431 #endif /* CONFIG_MODULES */
1432
1433 static struct notifier_block trace_module_nb = {
1434 .notifier_call = trace_module_notify,
1435 .priority = 0,
1436 };
1437
1438 extern struct ftrace_event_call *__start_ftrace_events[];
1439 extern struct ftrace_event_call *__stop_ftrace_events[];
1440
1441 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1442
1443 static __init int setup_trace_event(char *str)
1444 {
1445 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1446 ring_buffer_expanded = 1;
1447 tracing_selftest_disabled = 1;
1448
1449 return 1;
1450 }
1451 __setup("trace_event=", setup_trace_event);
1452
1453 static __init int event_trace_init(void)
1454 {
1455 struct ftrace_event_call **call;
1456 struct dentry *d_tracer;
1457 struct dentry *entry;
1458 struct dentry *d_events;
1459 int ret;
1460 char *buf = bootup_event_buf;
1461 char *token;
1462
1463 d_tracer = tracing_init_dentry();
1464 if (!d_tracer)
1465 return 0;
1466
1467 entry = debugfs_create_file("available_events", 0444, d_tracer,
1468 (void *)&show_event_seq_ops,
1469 &ftrace_avail_fops);
1470 if (!entry)
1471 pr_warning("Could not create debugfs "
1472 "'available_events' entry\n");
1473
1474 entry = debugfs_create_file("set_event", 0644, d_tracer,
1475 (void *)&show_set_event_seq_ops,
1476 &ftrace_set_event_fops);
1477 if (!entry)
1478 pr_warning("Could not create debugfs "
1479 "'set_event' entry\n");
1480
1481 d_events = event_trace_events_dir();
1482 if (!d_events)
1483 return 0;
1484
1485 /* ring buffer internal formats */
1486 trace_create_file("header_page", 0444, d_events,
1487 ring_buffer_print_page_header,
1488 &ftrace_show_header_fops);
1489
1490 trace_create_file("header_event", 0444, d_events,
1491 ring_buffer_print_entry_header,
1492 &ftrace_show_header_fops);
1493
1494 trace_create_file("enable", 0644, d_events,
1495 NULL, &ftrace_system_enable_fops);
1496
1497 if (trace_define_common_fields())
1498 pr_warning("tracing: Failed to allocate common fields");
1499
1500 for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
1501 __trace_add_event_call(*call, NULL, &ftrace_event_id_fops,
1502 &ftrace_enable_fops,
1503 &ftrace_event_filter_fops,
1504 &ftrace_event_format_fops);
1505 }
1506
1507 while (true) {
1508 token = strsep(&buf, ",");
1509
1510 if (!token)
1511 break;
1512 if (!*token)
1513 continue;
1514
1515 ret = ftrace_set_clr_event(token, 1);
1516 if (ret)
1517 pr_warning("Failed to enable trace event: %s\n", token);
1518 }
1519
1520 ret = register_module_notifier(&trace_module_nb);
1521 if (ret)
1522 pr_warning("Failed to register trace events module notifier\n");
1523
1524 return 0;
1525 }
1526 fs_initcall(event_trace_init);
1527
1528 #ifdef CONFIG_FTRACE_STARTUP_TEST
1529
1530 static DEFINE_SPINLOCK(test_spinlock);
1531 static DEFINE_SPINLOCK(test_spinlock_irq);
1532 static DEFINE_MUTEX(test_mutex);
1533
1534 static __init void test_work(struct work_struct *dummy)
1535 {
1536 spin_lock(&test_spinlock);
1537 spin_lock_irq(&test_spinlock_irq);
1538 udelay(1);
1539 spin_unlock_irq(&test_spinlock_irq);
1540 spin_unlock(&test_spinlock);
1541
1542 mutex_lock(&test_mutex);
1543 msleep(1);
1544 mutex_unlock(&test_mutex);
1545 }
1546
1547 static __init int event_test_thread(void *unused)
1548 {
1549 void *test_malloc;
1550
1551 test_malloc = kmalloc(1234, GFP_KERNEL);
1552 if (!test_malloc)
1553 pr_info("failed to kmalloc\n");
1554
1555 schedule_on_each_cpu(test_work);
1556
1557 kfree(test_malloc);
1558
1559 set_current_state(TASK_INTERRUPTIBLE);
1560 while (!kthread_should_stop())
1561 schedule();
1562
1563 return 0;
1564 }
1565
1566 /*
1567 * Do various things that may trigger events.
1568 */
1569 static __init void event_test_stuff(void)
1570 {
1571 struct task_struct *test_thread;
1572
1573 test_thread = kthread_run(event_test_thread, NULL, "test-events");
1574 msleep(1);
1575 kthread_stop(test_thread);
1576 }
1577
1578 /*
1579 * For every trace event defined, we will test each trace point separately,
1580 * and then by groups, and finally all trace points.
1581 */
1582 static __init void event_trace_self_tests(void)
1583 {
1584 struct ftrace_event_call *call;
1585 struct event_subsystem *system;
1586 int ret;
1587
1588 pr_info("Running tests on trace events:\n");
1589
1590 list_for_each_entry(call, &ftrace_events, list) {
1591
1592 /* Only test those that have a probe */
1593 if (!call->class || !call->class->probe)
1594 continue;
1595
1596 /*
1597 * Testing syscall events here is pretty useless, but
1598 * we still do it if configured. But this is time consuming.
1599 * What we really need is a user thread to perform the
1600 * syscalls as we test.
1601 */
1602 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1603 if (call->class->system &&
1604 strcmp(call->class->system, "syscalls") == 0)
1605 continue;
1606 #endif
1607
1608 pr_info("Testing event %s: ", call->name);
1609
1610 /*
1611 * If an event is already enabled, someone is using
1612 * it and the self test should not be on.
1613 */
1614 if (call->flags & TRACE_EVENT_FL_ENABLED) {
1615 pr_warning("Enabled event during self test!\n");
1616 WARN_ON_ONCE(1);
1617 continue;
1618 }
1619
1620 ftrace_event_enable_disable(call, 1);
1621 event_test_stuff();
1622 ftrace_event_enable_disable(call, 0);
1623
1624 pr_cont("OK\n");
1625 }
1626
1627 /* Now test at the sub system level */
1628
1629 pr_info("Running tests on trace event systems:\n");
1630
1631 list_for_each_entry(system, &event_subsystems, list) {
1632
1633 /* the ftrace system is special, skip it */
1634 if (strcmp(system->name, "ftrace") == 0)
1635 continue;
1636
1637 pr_info("Testing event system %s: ", system->name);
1638
1639 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1640 if (WARN_ON_ONCE(ret)) {
1641 pr_warning("error enabling system %s\n",
1642 system->name);
1643 continue;
1644 }
1645
1646 event_test_stuff();
1647
1648 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1649 if (WARN_ON_ONCE(ret))
1650 pr_warning("error disabling system %s\n",
1651 system->name);
1652
1653 pr_cont("OK\n");
1654 }
1655
1656 /* Test with all events enabled */
1657
1658 pr_info("Running tests on all trace events:\n");
1659 pr_info("Testing all events: ");
1660
1661 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1662 if (WARN_ON_ONCE(ret)) {
1663 pr_warning("error enabling all events\n");
1664 return;
1665 }
1666
1667 event_test_stuff();
1668
1669 /* reset sysname */
1670 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1671 if (WARN_ON_ONCE(ret)) {
1672 pr_warning("error disabling all events\n");
1673 return;
1674 }
1675
1676 pr_cont("OK\n");
1677 }
1678
1679 #ifdef CONFIG_FUNCTION_TRACER
1680
1681 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1682
1683 static void
1684 function_test_events_call(unsigned long ip, unsigned long parent_ip)
1685 {
1686 struct ring_buffer_event *event;
1687 struct ring_buffer *buffer;
1688 struct ftrace_entry *entry;
1689 unsigned long flags;
1690 long disabled;
1691 int cpu;
1692 int pc;
1693
1694 pc = preempt_count();
1695 preempt_disable_notrace();
1696 cpu = raw_smp_processor_id();
1697 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1698
1699 if (disabled != 1)
1700 goto out;
1701
1702 local_save_flags(flags);
1703
1704 event = trace_current_buffer_lock_reserve(&buffer,
1705 TRACE_FN, sizeof(*entry),
1706 flags, pc);
1707 if (!event)
1708 goto out;
1709 entry = ring_buffer_event_data(event);
1710 entry->ip = ip;
1711 entry->parent_ip = parent_ip;
1712
1713 trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
1714
1715 out:
1716 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1717 preempt_enable_notrace();
1718 }
1719
1720 static struct ftrace_ops trace_ops __initdata =
1721 {
1722 .func = function_test_events_call,
1723 };
1724
1725 static __init void event_trace_self_test_with_function(void)
1726 {
1727 int ret;
1728 ret = register_ftrace_function(&trace_ops);
1729 if (WARN_ON(ret < 0)) {
1730 pr_info("Failed to enable function tracer for event tests\n");
1731 return;
1732 }
1733 pr_info("Running tests again, along with the function tracer\n");
1734 event_trace_self_tests();
1735 unregister_ftrace_function(&trace_ops);
1736 }
1737 #else
1738 static __init void event_trace_self_test_with_function(void)
1739 {
1740 }
1741 #endif
1742
1743 static __init int event_trace_self_tests_init(void)
1744 {
1745 if (!tracing_selftest_disabled) {
1746 event_trace_self_tests();
1747 event_trace_self_test_with_function();
1748 }
1749
1750 return 0;
1751 }
1752
1753 late_initcall(event_trace_self_tests_init);
1754
1755 #endif
Linus' kernel tree