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locking: Rename __RAW_SPIN_LOCK_UNLOCKED to __ARCH_SPIN_LOCK_UNLOCKED
[deliverable/linux.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/delay.h>
19
20 #include <asm/setup.h>
21
22 #include "trace_output.h"
23
24 #undef TRACE_SYSTEM
25 #define TRACE_SYSTEM "TRACE_SYSTEM"
26
27 DEFINE_MUTEX(event_mutex);
28
29 LIST_HEAD(ftrace_events);
30
31 int trace_define_field(struct ftrace_event_call *call, const char *type,
32 const char *name, int offset, int size, int is_signed,
33 int filter_type)
34 {
35 struct ftrace_event_field *field;
36
37 field = kzalloc(sizeof(*field), GFP_KERNEL);
38 if (!field)
39 goto err;
40
41 field->name = kstrdup(name, GFP_KERNEL);
42 if (!field->name)
43 goto err;
44
45 field->type = kstrdup(type, GFP_KERNEL);
46 if (!field->type)
47 goto err;
48
49 if (filter_type == FILTER_OTHER)
50 field->filter_type = filter_assign_type(type);
51 else
52 field->filter_type = filter_type;
53
54 field->offset = offset;
55 field->size = size;
56 field->is_signed = is_signed;
57
58 list_add(&field->link, &call->fields);
59
60 return 0;
61
62 err:
63 if (field) {
64 kfree(field->name);
65 kfree(field->type);
66 }
67 kfree(field);
68
69 return -ENOMEM;
70 }
71 EXPORT_SYMBOL_GPL(trace_define_field);
72
73 #define __common_field(type, item) \
74 ret = trace_define_field(call, #type, "common_" #item, \
75 offsetof(typeof(ent), item), \
76 sizeof(ent.item), \
77 is_signed_type(type), FILTER_OTHER); \
78 if (ret) \
79 return ret;
80
81 int trace_define_common_fields(struct ftrace_event_call *call)
82 {
83 int ret;
84 struct trace_entry ent;
85
86 __common_field(unsigned short, type);
87 __common_field(unsigned char, flags);
88 __common_field(unsigned char, preempt_count);
89 __common_field(int, pid);
90 __common_field(int, lock_depth);
91
92 return ret;
93 }
94 EXPORT_SYMBOL_GPL(trace_define_common_fields);
95
96 void trace_destroy_fields(struct ftrace_event_call *call)
97 {
98 struct ftrace_event_field *field, *next;
99
100 list_for_each_entry_safe(field, next, &call->fields, link) {
101 list_del(&field->link);
102 kfree(field->type);
103 kfree(field->name);
104 kfree(field);
105 }
106 }
107
108 static void ftrace_event_enable_disable(struct ftrace_event_call *call,
109 int enable)
110 {
111 switch (enable) {
112 case 0:
113 if (call->enabled) {
114 call->enabled = 0;
115 tracing_stop_cmdline_record();
116 call->unregfunc(call);
117 }
118 break;
119 case 1:
120 if (!call->enabled) {
121 call->enabled = 1;
122 tracing_start_cmdline_record();
123 call->regfunc(call);
124 }
125 break;
126 }
127 }
128
129 static void ftrace_clear_events(void)
130 {
131 struct ftrace_event_call *call;
132
133 mutex_lock(&event_mutex);
134 list_for_each_entry(call, &ftrace_events, list) {
135 ftrace_event_enable_disable(call, 0);
136 }
137 mutex_unlock(&event_mutex);
138 }
139
140 /*
141 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
142 */
143 static int __ftrace_set_clr_event(const char *match, const char *sub,
144 const char *event, int set)
145 {
146 struct ftrace_event_call *call;
147 int ret = -EINVAL;
148
149 mutex_lock(&event_mutex);
150 list_for_each_entry(call, &ftrace_events, list) {
151
152 if (!call->name || !call->regfunc)
153 continue;
154
155 if (match &&
156 strcmp(match, call->name) != 0 &&
157 strcmp(match, call->system) != 0)
158 continue;
159
160 if (sub && strcmp(sub, call->system) != 0)
161 continue;
162
163 if (event && strcmp(event, call->name) != 0)
164 continue;
165
166 ftrace_event_enable_disable(call, set);
167
168 ret = 0;
169 }
170 mutex_unlock(&event_mutex);
171
172 return ret;
173 }
174
175 static int ftrace_set_clr_event(char *buf, int set)
176 {
177 char *event = NULL, *sub = NULL, *match;
178
179 /*
180 * The buf format can be <subsystem>:<event-name>
181 * *:<event-name> means any event by that name.
182 * :<event-name> is the same.
183 *
184 * <subsystem>:* means all events in that subsystem
185 * <subsystem>: means the same.
186 *
187 * <name> (no ':') means all events in a subsystem with
188 * the name <name> or any event that matches <name>
189 */
190
191 match = strsep(&buf, ":");
192 if (buf) {
193 sub = match;
194 event = buf;
195 match = NULL;
196
197 if (!strlen(sub) || strcmp(sub, "*") == 0)
198 sub = NULL;
199 if (!strlen(event) || strcmp(event, "*") == 0)
200 event = NULL;
201 }
202
203 return __ftrace_set_clr_event(match, sub, event, set);
204 }
205
206 /**
207 * trace_set_clr_event - enable or disable an event
208 * @system: system name to match (NULL for any system)
209 * @event: event name to match (NULL for all events, within system)
210 * @set: 1 to enable, 0 to disable
211 *
212 * This is a way for other parts of the kernel to enable or disable
213 * event recording.
214 *
215 * Returns 0 on success, -EINVAL if the parameters do not match any
216 * registered events.
217 */
218 int trace_set_clr_event(const char *system, const char *event, int set)
219 {
220 return __ftrace_set_clr_event(NULL, system, event, set);
221 }
222
223 /* 128 should be much more than enough */
224 #define EVENT_BUF_SIZE 127
225
226 static ssize_t
227 ftrace_event_write(struct file *file, const char __user *ubuf,
228 size_t cnt, loff_t *ppos)
229 {
230 struct trace_parser parser;
231 ssize_t read, ret;
232
233 if (!cnt)
234 return 0;
235
236 ret = tracing_update_buffers();
237 if (ret < 0)
238 return ret;
239
240 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
241 return -ENOMEM;
242
243 read = trace_get_user(&parser, ubuf, cnt, ppos);
244
245 if (read >= 0 && trace_parser_loaded((&parser))) {
246 int set = 1;
247
248 if (*parser.buffer == '!')
249 set = 0;
250
251 parser.buffer[parser.idx] = 0;
252
253 ret = ftrace_set_clr_event(parser.buffer + !set, set);
254 if (ret)
255 goto out_put;
256 }
257
258 ret = read;
259
260 out_put:
261 trace_parser_put(&parser);
262
263 return ret;
264 }
265
266 static void *
267 t_next(struct seq_file *m, void *v, loff_t *pos)
268 {
269 struct ftrace_event_call *call = v;
270
271 (*pos)++;
272
273 list_for_each_entry_continue(call, &ftrace_events, list) {
274 /*
275 * The ftrace subsystem is for showing formats only.
276 * They can not be enabled or disabled via the event files.
277 */
278 if (call->regfunc)
279 return call;
280 }
281
282 return NULL;
283 }
284
285 static void *t_start(struct seq_file *m, loff_t *pos)
286 {
287 struct ftrace_event_call *call;
288 loff_t l;
289
290 mutex_lock(&event_mutex);
291
292 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
293 for (l = 0; l <= *pos; ) {
294 call = t_next(m, call, &l);
295 if (!call)
296 break;
297 }
298 return call;
299 }
300
301 static void *
302 s_next(struct seq_file *m, void *v, loff_t *pos)
303 {
304 struct ftrace_event_call *call = v;
305
306 (*pos)++;
307
308 list_for_each_entry_continue(call, &ftrace_events, list) {
309 if (call->enabled)
310 return call;
311 }
312
313 return NULL;
314 }
315
316 static void *s_start(struct seq_file *m, loff_t *pos)
317 {
318 struct ftrace_event_call *call;
319 loff_t l;
320
321 mutex_lock(&event_mutex);
322
323 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
324 for (l = 0; l <= *pos; ) {
325 call = s_next(m, call, &l);
326 if (!call)
327 break;
328 }
329 return call;
330 }
331
332 static int t_show(struct seq_file *m, void *v)
333 {
334 struct ftrace_event_call *call = v;
335
336 if (strcmp(call->system, TRACE_SYSTEM) != 0)
337 seq_printf(m, "%s:", call->system);
338 seq_printf(m, "%s\n", call->name);
339
340 return 0;
341 }
342
343 static void t_stop(struct seq_file *m, void *p)
344 {
345 mutex_unlock(&event_mutex);
346 }
347
348 static int
349 ftrace_event_seq_open(struct inode *inode, struct file *file)
350 {
351 const struct seq_operations *seq_ops;
352
353 if ((file->f_mode & FMODE_WRITE) &&
354 (file->f_flags & O_TRUNC))
355 ftrace_clear_events();
356
357 seq_ops = inode->i_private;
358 return seq_open(file, seq_ops);
359 }
360
361 static ssize_t
362 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
363 loff_t *ppos)
364 {
365 struct ftrace_event_call *call = filp->private_data;
366 char *buf;
367
368 if (call->enabled)
369 buf = "1\n";
370 else
371 buf = "0\n";
372
373 return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
374 }
375
376 static ssize_t
377 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
378 loff_t *ppos)
379 {
380 struct ftrace_event_call *call = filp->private_data;
381 char buf[64];
382 unsigned long val;
383 int ret;
384
385 if (cnt >= sizeof(buf))
386 return -EINVAL;
387
388 if (copy_from_user(&buf, ubuf, cnt))
389 return -EFAULT;
390
391 buf[cnt] = 0;
392
393 ret = strict_strtoul(buf, 10, &val);
394 if (ret < 0)
395 return ret;
396
397 ret = tracing_update_buffers();
398 if (ret < 0)
399 return ret;
400
401 switch (val) {
402 case 0:
403 case 1:
404 mutex_lock(&event_mutex);
405 ftrace_event_enable_disable(call, val);
406 mutex_unlock(&event_mutex);
407 break;
408
409 default:
410 return -EINVAL;
411 }
412
413 *ppos += cnt;
414
415 return cnt;
416 }
417
418 static ssize_t
419 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
420 loff_t *ppos)
421 {
422 const char set_to_char[4] = { '?', '0', '1', 'X' };
423 const char *system = filp->private_data;
424 struct ftrace_event_call *call;
425 char buf[2];
426 int set = 0;
427 int ret;
428
429 mutex_lock(&event_mutex);
430 list_for_each_entry(call, &ftrace_events, list) {
431 if (!call->name || !call->regfunc)
432 continue;
433
434 if (system && strcmp(call->system, system) != 0)
435 continue;
436
437 /*
438 * We need to find out if all the events are set
439 * or if all events or cleared, or if we have
440 * a mixture.
441 */
442 set |= (1 << !!call->enabled);
443
444 /*
445 * If we have a mixture, no need to look further.
446 */
447 if (set == 3)
448 break;
449 }
450 mutex_unlock(&event_mutex);
451
452 buf[0] = set_to_char[set];
453 buf[1] = '\n';
454
455 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
456
457 return ret;
458 }
459
460 static ssize_t
461 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
462 loff_t *ppos)
463 {
464 const char *system = filp->private_data;
465 unsigned long val;
466 char buf[64];
467 ssize_t ret;
468
469 if (cnt >= sizeof(buf))
470 return -EINVAL;
471
472 if (copy_from_user(&buf, ubuf, cnt))
473 return -EFAULT;
474
475 buf[cnt] = 0;
476
477 ret = strict_strtoul(buf, 10, &val);
478 if (ret < 0)
479 return ret;
480
481 ret = tracing_update_buffers();
482 if (ret < 0)
483 return ret;
484
485 if (val != 0 && val != 1)
486 return -EINVAL;
487
488 ret = __ftrace_set_clr_event(NULL, system, NULL, val);
489 if (ret)
490 goto out;
491
492 ret = cnt;
493
494 out:
495 *ppos += cnt;
496
497 return ret;
498 }
499
500 extern char *__bad_type_size(void);
501
502 #undef FIELD
503 #define FIELD(type, name) \
504 sizeof(type) != sizeof(field.name) ? __bad_type_size() : \
505 #type, "common_" #name, offsetof(typeof(field), name), \
506 sizeof(field.name), is_signed_type(type)
507
508 static int trace_write_header(struct trace_seq *s)
509 {
510 struct trace_entry field;
511
512 /* struct trace_entry */
513 return trace_seq_printf(s,
514 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"
515 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"
516 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"
517 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"
518 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"
519 "\n",
520 FIELD(unsigned short, type),
521 FIELD(unsigned char, flags),
522 FIELD(unsigned char, preempt_count),
523 FIELD(int, pid),
524 FIELD(int, lock_depth));
525 }
526
527 static ssize_t
528 event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
529 loff_t *ppos)
530 {
531 struct ftrace_event_call *call = filp->private_data;
532 struct trace_seq *s;
533 char *buf;
534 int r;
535
536 if (*ppos)
537 return 0;
538
539 s = kmalloc(sizeof(*s), GFP_KERNEL);
540 if (!s)
541 return -ENOMEM;
542
543 trace_seq_init(s);
544
545 /* If any of the first writes fail, so will the show_format. */
546
547 trace_seq_printf(s, "name: %s\n", call->name);
548 trace_seq_printf(s, "ID: %d\n", call->id);
549 trace_seq_printf(s, "format:\n");
550 trace_write_header(s);
551
552 r = call->show_format(call, s);
553 if (!r) {
554 /*
555 * ug! The format output is bigger than a PAGE!!
556 */
557 buf = "FORMAT TOO BIG\n";
558 r = simple_read_from_buffer(ubuf, cnt, ppos,
559 buf, strlen(buf));
560 goto out;
561 }
562
563 r = simple_read_from_buffer(ubuf, cnt, ppos,
564 s->buffer, s->len);
565 out:
566 kfree(s);
567 return r;
568 }
569
570 static ssize_t
571 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
572 {
573 struct ftrace_event_call *call = filp->private_data;
574 struct trace_seq *s;
575 int r;
576
577 if (*ppos)
578 return 0;
579
580 s = kmalloc(sizeof(*s), GFP_KERNEL);
581 if (!s)
582 return -ENOMEM;
583
584 trace_seq_init(s);
585 trace_seq_printf(s, "%d\n", call->id);
586
587 r = simple_read_from_buffer(ubuf, cnt, ppos,
588 s->buffer, s->len);
589 kfree(s);
590 return r;
591 }
592
593 static ssize_t
594 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
595 loff_t *ppos)
596 {
597 struct ftrace_event_call *call = filp->private_data;
598 struct trace_seq *s;
599 int r;
600
601 if (*ppos)
602 return 0;
603
604 s = kmalloc(sizeof(*s), GFP_KERNEL);
605 if (!s)
606 return -ENOMEM;
607
608 trace_seq_init(s);
609
610 print_event_filter(call, s);
611 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
612
613 kfree(s);
614
615 return r;
616 }
617
618 static ssize_t
619 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
620 loff_t *ppos)
621 {
622 struct ftrace_event_call *call = filp->private_data;
623 char *buf;
624 int err;
625
626 if (cnt >= PAGE_SIZE)
627 return -EINVAL;
628
629 buf = (char *)__get_free_page(GFP_TEMPORARY);
630 if (!buf)
631 return -ENOMEM;
632
633 if (copy_from_user(buf, ubuf, cnt)) {
634 free_page((unsigned long) buf);
635 return -EFAULT;
636 }
637 buf[cnt] = '\0';
638
639 err = apply_event_filter(call, buf);
640 free_page((unsigned long) buf);
641 if (err < 0)
642 return err;
643
644 *ppos += cnt;
645
646 return cnt;
647 }
648
649 static ssize_t
650 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
651 loff_t *ppos)
652 {
653 struct event_subsystem *system = filp->private_data;
654 struct trace_seq *s;
655 int r;
656
657 if (*ppos)
658 return 0;
659
660 s = kmalloc(sizeof(*s), GFP_KERNEL);
661 if (!s)
662 return -ENOMEM;
663
664 trace_seq_init(s);
665
666 print_subsystem_event_filter(system, s);
667 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
668
669 kfree(s);
670
671 return r;
672 }
673
674 static ssize_t
675 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
676 loff_t *ppos)
677 {
678 struct event_subsystem *system = filp->private_data;
679 char *buf;
680 int err;
681
682 if (cnt >= PAGE_SIZE)
683 return -EINVAL;
684
685 buf = (char *)__get_free_page(GFP_TEMPORARY);
686 if (!buf)
687 return -ENOMEM;
688
689 if (copy_from_user(buf, ubuf, cnt)) {
690 free_page((unsigned long) buf);
691 return -EFAULT;
692 }
693 buf[cnt] = '\0';
694
695 err = apply_subsystem_event_filter(system, buf);
696 free_page((unsigned long) buf);
697 if (err < 0)
698 return err;
699
700 *ppos += cnt;
701
702 return cnt;
703 }
704
705 static ssize_t
706 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
707 {
708 int (*func)(struct trace_seq *s) = filp->private_data;
709 struct trace_seq *s;
710 int r;
711
712 if (*ppos)
713 return 0;
714
715 s = kmalloc(sizeof(*s), GFP_KERNEL);
716 if (!s)
717 return -ENOMEM;
718
719 trace_seq_init(s);
720
721 func(s);
722 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
723
724 kfree(s);
725
726 return r;
727 }
728
729 static const struct seq_operations show_event_seq_ops = {
730 .start = t_start,
731 .next = t_next,
732 .show = t_show,
733 .stop = t_stop,
734 };
735
736 static const struct seq_operations show_set_event_seq_ops = {
737 .start = s_start,
738 .next = s_next,
739 .show = t_show,
740 .stop = t_stop,
741 };
742
743 static const struct file_operations ftrace_avail_fops = {
744 .open = ftrace_event_seq_open,
745 .read = seq_read,
746 .llseek = seq_lseek,
747 .release = seq_release,
748 };
749
750 static const struct file_operations ftrace_set_event_fops = {
751 .open = ftrace_event_seq_open,
752 .read = seq_read,
753 .write = ftrace_event_write,
754 .llseek = seq_lseek,
755 .release = seq_release,
756 };
757
758 static const struct file_operations ftrace_enable_fops = {
759 .open = tracing_open_generic,
760 .read = event_enable_read,
761 .write = event_enable_write,
762 };
763
764 static const struct file_operations ftrace_event_format_fops = {
765 .open = tracing_open_generic,
766 .read = event_format_read,
767 };
768
769 static const struct file_operations ftrace_event_id_fops = {
770 .open = tracing_open_generic,
771 .read = event_id_read,
772 };
773
774 static const struct file_operations ftrace_event_filter_fops = {
775 .open = tracing_open_generic,
776 .read = event_filter_read,
777 .write = event_filter_write,
778 };
779
780 static const struct file_operations ftrace_subsystem_filter_fops = {
781 .open = tracing_open_generic,
782 .read = subsystem_filter_read,
783 .write = subsystem_filter_write,
784 };
785
786 static const struct file_operations ftrace_system_enable_fops = {
787 .open = tracing_open_generic,
788 .read = system_enable_read,
789 .write = system_enable_write,
790 };
791
792 static const struct file_operations ftrace_show_header_fops = {
793 .open = tracing_open_generic,
794 .read = show_header,
795 };
796
797 static struct dentry *event_trace_events_dir(void)
798 {
799 static struct dentry *d_tracer;
800 static struct dentry *d_events;
801
802 if (d_events)
803 return d_events;
804
805 d_tracer = tracing_init_dentry();
806 if (!d_tracer)
807 return NULL;
808
809 d_events = debugfs_create_dir("events", d_tracer);
810 if (!d_events)
811 pr_warning("Could not create debugfs "
812 "'events' directory\n");
813
814 return d_events;
815 }
816
817 static LIST_HEAD(event_subsystems);
818
819 static struct dentry *
820 event_subsystem_dir(const char *name, struct dentry *d_events)
821 {
822 struct event_subsystem *system;
823 struct dentry *entry;
824
825 /* First see if we did not already create this dir */
826 list_for_each_entry(system, &event_subsystems, list) {
827 if (strcmp(system->name, name) == 0) {
828 system->nr_events++;
829 return system->entry;
830 }
831 }
832
833 /* need to create new entry */
834 system = kmalloc(sizeof(*system), GFP_KERNEL);
835 if (!system) {
836 pr_warning("No memory to create event subsystem %s\n",
837 name);
838 return d_events;
839 }
840
841 system->entry = debugfs_create_dir(name, d_events);
842 if (!system->entry) {
843 pr_warning("Could not create event subsystem %s\n",
844 name);
845 kfree(system);
846 return d_events;
847 }
848
849 system->nr_events = 1;
850 system->name = kstrdup(name, GFP_KERNEL);
851 if (!system->name) {
852 debugfs_remove(system->entry);
853 kfree(system);
854 return d_events;
855 }
856
857 list_add(&system->list, &event_subsystems);
858
859 system->filter = NULL;
860
861 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
862 if (!system->filter) {
863 pr_warning("Could not allocate filter for subsystem "
864 "'%s'\n", name);
865 return system->entry;
866 }
867
868 entry = debugfs_create_file("filter", 0644, system->entry, system,
869 &ftrace_subsystem_filter_fops);
870 if (!entry) {
871 kfree(system->filter);
872 system->filter = NULL;
873 pr_warning("Could not create debugfs "
874 "'%s/filter' entry\n", name);
875 }
876
877 trace_create_file("enable", 0644, system->entry,
878 (void *)system->name,
879 &ftrace_system_enable_fops);
880
881 return system->entry;
882 }
883
884 static int
885 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
886 const struct file_operations *id,
887 const struct file_operations *enable,
888 const struct file_operations *filter,
889 const struct file_operations *format)
890 {
891 int ret;
892
893 /*
894 * If the trace point header did not define TRACE_SYSTEM
895 * then the system would be called "TRACE_SYSTEM".
896 */
897 if (strcmp(call->system, TRACE_SYSTEM) != 0)
898 d_events = event_subsystem_dir(call->system, d_events);
899
900 call->dir = debugfs_create_dir(call->name, d_events);
901 if (!call->dir) {
902 pr_warning("Could not create debugfs "
903 "'%s' directory\n", call->name);
904 return -1;
905 }
906
907 if (call->regfunc)
908 trace_create_file("enable", 0644, call->dir, call,
909 enable);
910
911 if (call->id && call->profile_enable)
912 trace_create_file("id", 0444, call->dir, call,
913 id);
914
915 if (call->define_fields) {
916 ret = call->define_fields(call);
917 if (ret < 0) {
918 pr_warning("Could not initialize trace point"
919 " events/%s\n", call->name);
920 return ret;
921 }
922 trace_create_file("filter", 0644, call->dir, call,
923 filter);
924 }
925
926 /* A trace may not want to export its format */
927 if (!call->show_format)
928 return 0;
929
930 trace_create_file("format", 0444, call->dir, call,
931 format);
932
933 return 0;
934 }
935
936 static int __trace_add_event_call(struct ftrace_event_call *call)
937 {
938 struct dentry *d_events;
939 int ret;
940
941 if (!call->name)
942 return -EINVAL;
943
944 if (call->raw_init) {
945 ret = call->raw_init(call);
946 if (ret < 0) {
947 if (ret != -ENOSYS)
948 pr_warning("Could not initialize trace "
949 "events/%s\n", call->name);
950 return ret;
951 }
952 }
953
954 d_events = event_trace_events_dir();
955 if (!d_events)
956 return -ENOENT;
957
958 ret = event_create_dir(call, d_events, &ftrace_event_id_fops,
959 &ftrace_enable_fops, &ftrace_event_filter_fops,
960 &ftrace_event_format_fops);
961 if (!ret)
962 list_add(&call->list, &ftrace_events);
963
964 return ret;
965 }
966
967 /* Add an additional event_call dynamically */
968 int trace_add_event_call(struct ftrace_event_call *call)
969 {
970 int ret;
971 mutex_lock(&event_mutex);
972 ret = __trace_add_event_call(call);
973 mutex_unlock(&event_mutex);
974 return ret;
975 }
976
977 static void remove_subsystem_dir(const char *name)
978 {
979 struct event_subsystem *system;
980
981 if (strcmp(name, TRACE_SYSTEM) == 0)
982 return;
983
984 list_for_each_entry(system, &event_subsystems, list) {
985 if (strcmp(system->name, name) == 0) {
986 if (!--system->nr_events) {
987 struct event_filter *filter = system->filter;
988
989 debugfs_remove_recursive(system->entry);
990 list_del(&system->list);
991 if (filter) {
992 kfree(filter->filter_string);
993 kfree(filter);
994 }
995 kfree(system->name);
996 kfree(system);
997 }
998 break;
999 }
1000 }
1001 }
1002
1003 /*
1004 * Must be called under locking both of event_mutex and trace_event_mutex.
1005 */
1006 static void __trace_remove_event_call(struct ftrace_event_call *call)
1007 {
1008 ftrace_event_enable_disable(call, 0);
1009 if (call->event)
1010 __unregister_ftrace_event(call->event);
1011 debugfs_remove_recursive(call->dir);
1012 list_del(&call->list);
1013 trace_destroy_fields(call);
1014 destroy_preds(call);
1015 remove_subsystem_dir(call->system);
1016 }
1017
1018 /* Remove an event_call */
1019 void trace_remove_event_call(struct ftrace_event_call *call)
1020 {
1021 mutex_lock(&event_mutex);
1022 down_write(&trace_event_mutex);
1023 __trace_remove_event_call(call);
1024 up_write(&trace_event_mutex);
1025 mutex_unlock(&event_mutex);
1026 }
1027
1028 #define for_each_event(event, start, end) \
1029 for (event = start; \
1030 (unsigned long)event < (unsigned long)end; \
1031 event++)
1032
1033 #ifdef CONFIG_MODULES
1034
1035 static LIST_HEAD(ftrace_module_file_list);
1036
1037 /*
1038 * Modules must own their file_operations to keep up with
1039 * reference counting.
1040 */
1041 struct ftrace_module_file_ops {
1042 struct list_head list;
1043 struct module *mod;
1044 struct file_operations id;
1045 struct file_operations enable;
1046 struct file_operations format;
1047 struct file_operations filter;
1048 };
1049
1050 static struct ftrace_module_file_ops *
1051 trace_create_file_ops(struct module *mod)
1052 {
1053 struct ftrace_module_file_ops *file_ops;
1054
1055 /*
1056 * This is a bit of a PITA. To allow for correct reference
1057 * counting, modules must "own" their file_operations.
1058 * To do this, we allocate the file operations that will be
1059 * used in the event directory.
1060 */
1061
1062 file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1063 if (!file_ops)
1064 return NULL;
1065
1066 file_ops->mod = mod;
1067
1068 file_ops->id = ftrace_event_id_fops;
1069 file_ops->id.owner = mod;
1070
1071 file_ops->enable = ftrace_enable_fops;
1072 file_ops->enable.owner = mod;
1073
1074 file_ops->filter = ftrace_event_filter_fops;
1075 file_ops->filter.owner = mod;
1076
1077 file_ops->format = ftrace_event_format_fops;
1078 file_ops->format.owner = mod;
1079
1080 list_add(&file_ops->list, &ftrace_module_file_list);
1081
1082 return file_ops;
1083 }
1084
1085 static void trace_module_add_events(struct module *mod)
1086 {
1087 struct ftrace_module_file_ops *file_ops = NULL;
1088 struct ftrace_event_call *call, *start, *end;
1089 struct dentry *d_events;
1090 int ret;
1091
1092 start = mod->trace_events;
1093 end = mod->trace_events + mod->num_trace_events;
1094
1095 if (start == end)
1096 return;
1097
1098 d_events = event_trace_events_dir();
1099 if (!d_events)
1100 return;
1101
1102 for_each_event(call, start, end) {
1103 /* The linker may leave blanks */
1104 if (!call->name)
1105 continue;
1106 if (call->raw_init) {
1107 ret = call->raw_init(call);
1108 if (ret < 0) {
1109 if (ret != -ENOSYS)
1110 pr_warning("Could not initialize trace "
1111 "point events/%s\n", call->name);
1112 continue;
1113 }
1114 }
1115 /*
1116 * This module has events, create file ops for this module
1117 * if not already done.
1118 */
1119 if (!file_ops) {
1120 file_ops = trace_create_file_ops(mod);
1121 if (!file_ops)
1122 return;
1123 }
1124 call->mod = mod;
1125 ret = event_create_dir(call, d_events,
1126 &file_ops->id, &file_ops->enable,
1127 &file_ops->filter, &file_ops->format);
1128 if (!ret)
1129 list_add(&call->list, &ftrace_events);
1130 }
1131 }
1132
1133 static void trace_module_remove_events(struct module *mod)
1134 {
1135 struct ftrace_module_file_ops *file_ops;
1136 struct ftrace_event_call *call, *p;
1137 bool found = false;
1138
1139 down_write(&trace_event_mutex);
1140 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1141 if (call->mod == mod) {
1142 found = true;
1143 __trace_remove_event_call(call);
1144 }
1145 }
1146
1147 /* Now free the file_operations */
1148 list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1149 if (file_ops->mod == mod)
1150 break;
1151 }
1152 if (&file_ops->list != &ftrace_module_file_list) {
1153 list_del(&file_ops->list);
1154 kfree(file_ops);
1155 }
1156
1157 /*
1158 * It is safest to reset the ring buffer if the module being unloaded
1159 * registered any events.
1160 */
1161 if (found)
1162 tracing_reset_current_online_cpus();
1163 up_write(&trace_event_mutex);
1164 }
1165
1166 static int trace_module_notify(struct notifier_block *self,
1167 unsigned long val, void *data)
1168 {
1169 struct module *mod = data;
1170
1171 mutex_lock(&event_mutex);
1172 switch (val) {
1173 case MODULE_STATE_COMING:
1174 trace_module_add_events(mod);
1175 break;
1176 case MODULE_STATE_GOING:
1177 trace_module_remove_events(mod);
1178 break;
1179 }
1180 mutex_unlock(&event_mutex);
1181
1182 return 0;
1183 }
1184 #else
1185 static int trace_module_notify(struct notifier_block *self,
1186 unsigned long val, void *data)
1187 {
1188 return 0;
1189 }
1190 #endif /* CONFIG_MODULES */
1191
1192 static struct notifier_block trace_module_nb = {
1193 .notifier_call = trace_module_notify,
1194 .priority = 0,
1195 };
1196
1197 extern struct ftrace_event_call __start_ftrace_events[];
1198 extern struct ftrace_event_call __stop_ftrace_events[];
1199
1200 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1201
1202 static __init int setup_trace_event(char *str)
1203 {
1204 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1205 ring_buffer_expanded = 1;
1206 tracing_selftest_disabled = 1;
1207
1208 return 1;
1209 }
1210 __setup("trace_event=", setup_trace_event);
1211
1212 static __init int event_trace_init(void)
1213 {
1214 struct ftrace_event_call *call;
1215 struct dentry *d_tracer;
1216 struct dentry *entry;
1217 struct dentry *d_events;
1218 int ret;
1219 char *buf = bootup_event_buf;
1220 char *token;
1221
1222 d_tracer = tracing_init_dentry();
1223 if (!d_tracer)
1224 return 0;
1225
1226 entry = debugfs_create_file("available_events", 0444, d_tracer,
1227 (void *)&show_event_seq_ops,
1228 &ftrace_avail_fops);
1229 if (!entry)
1230 pr_warning("Could not create debugfs "
1231 "'available_events' entry\n");
1232
1233 entry = debugfs_create_file("set_event", 0644, d_tracer,
1234 (void *)&show_set_event_seq_ops,
1235 &ftrace_set_event_fops);
1236 if (!entry)
1237 pr_warning("Could not create debugfs "
1238 "'set_event' entry\n");
1239
1240 d_events = event_trace_events_dir();
1241 if (!d_events)
1242 return 0;
1243
1244 /* ring buffer internal formats */
1245 trace_create_file("header_page", 0444, d_events,
1246 ring_buffer_print_page_header,
1247 &ftrace_show_header_fops);
1248
1249 trace_create_file("header_event", 0444, d_events,
1250 ring_buffer_print_entry_header,
1251 &ftrace_show_header_fops);
1252
1253 trace_create_file("enable", 0644, d_events,
1254 NULL, &ftrace_system_enable_fops);
1255
1256 for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
1257 /* The linker may leave blanks */
1258 if (!call->name)
1259 continue;
1260 if (call->raw_init) {
1261 ret = call->raw_init(call);
1262 if (ret < 0) {
1263 if (ret != -ENOSYS)
1264 pr_warning("Could not initialize trace "
1265 "point events/%s\n", call->name);
1266 continue;
1267 }
1268 }
1269 ret = event_create_dir(call, d_events, &ftrace_event_id_fops,
1270 &ftrace_enable_fops,
1271 &ftrace_event_filter_fops,
1272 &ftrace_event_format_fops);
1273 if (!ret)
1274 list_add(&call->list, &ftrace_events);
1275 }
1276
1277 while (true) {
1278 token = strsep(&buf, ",");
1279
1280 if (!token)
1281 break;
1282 if (!*token)
1283 continue;
1284
1285 ret = ftrace_set_clr_event(token, 1);
1286 if (ret)
1287 pr_warning("Failed to enable trace event: %s\n", token);
1288 }
1289
1290 ret = register_module_notifier(&trace_module_nb);
1291 if (ret)
1292 pr_warning("Failed to register trace events module notifier\n");
1293
1294 return 0;
1295 }
1296 fs_initcall(event_trace_init);
1297
1298 #ifdef CONFIG_FTRACE_STARTUP_TEST
1299
1300 static DEFINE_SPINLOCK(test_spinlock);
1301 static DEFINE_SPINLOCK(test_spinlock_irq);
1302 static DEFINE_MUTEX(test_mutex);
1303
1304 static __init void test_work(struct work_struct *dummy)
1305 {
1306 spin_lock(&test_spinlock);
1307 spin_lock_irq(&test_spinlock_irq);
1308 udelay(1);
1309 spin_unlock_irq(&test_spinlock_irq);
1310 spin_unlock(&test_spinlock);
1311
1312 mutex_lock(&test_mutex);
1313 msleep(1);
1314 mutex_unlock(&test_mutex);
1315 }
1316
1317 static __init int event_test_thread(void *unused)
1318 {
1319 void *test_malloc;
1320
1321 test_malloc = kmalloc(1234, GFP_KERNEL);
1322 if (!test_malloc)
1323 pr_info("failed to kmalloc\n");
1324
1325 schedule_on_each_cpu(test_work);
1326
1327 kfree(test_malloc);
1328
1329 set_current_state(TASK_INTERRUPTIBLE);
1330 while (!kthread_should_stop())
1331 schedule();
1332
1333 return 0;
1334 }
1335
1336 /*
1337 * Do various things that may trigger events.
1338 */
1339 static __init void event_test_stuff(void)
1340 {
1341 struct task_struct *test_thread;
1342
1343 test_thread = kthread_run(event_test_thread, NULL, "test-events");
1344 msleep(1);
1345 kthread_stop(test_thread);
1346 }
1347
1348 /*
1349 * For every trace event defined, we will test each trace point separately,
1350 * and then by groups, and finally all trace points.
1351 */
1352 static __init void event_trace_self_tests(void)
1353 {
1354 struct ftrace_event_call *call;
1355 struct event_subsystem *system;
1356 int ret;
1357
1358 pr_info("Running tests on trace events:\n");
1359
1360 list_for_each_entry(call, &ftrace_events, list) {
1361
1362 /* Only test those that have a regfunc */
1363 if (!call->regfunc)
1364 continue;
1365
1366 /*
1367 * Testing syscall events here is pretty useless, but
1368 * we still do it if configured. But this is time consuming.
1369 * What we really need is a user thread to perform the
1370 * syscalls as we test.
1371 */
1372 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1373 if (call->system &&
1374 strcmp(call->system, "syscalls") == 0)
1375 continue;
1376 #endif
1377
1378 pr_info("Testing event %s: ", call->name);
1379
1380 /*
1381 * If an event is already enabled, someone is using
1382 * it and the self test should not be on.
1383 */
1384 if (call->enabled) {
1385 pr_warning("Enabled event during self test!\n");
1386 WARN_ON_ONCE(1);
1387 continue;
1388 }
1389
1390 ftrace_event_enable_disable(call, 1);
1391 event_test_stuff();
1392 ftrace_event_enable_disable(call, 0);
1393
1394 pr_cont("OK\n");
1395 }
1396
1397 /* Now test at the sub system level */
1398
1399 pr_info("Running tests on trace event systems:\n");
1400
1401 list_for_each_entry(system, &event_subsystems, list) {
1402
1403 /* the ftrace system is special, skip it */
1404 if (strcmp(system->name, "ftrace") == 0)
1405 continue;
1406
1407 pr_info("Testing event system %s: ", system->name);
1408
1409 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1410 if (WARN_ON_ONCE(ret)) {
1411 pr_warning("error enabling system %s\n",
1412 system->name);
1413 continue;
1414 }
1415
1416 event_test_stuff();
1417
1418 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1419 if (WARN_ON_ONCE(ret))
1420 pr_warning("error disabling system %s\n",
1421 system->name);
1422
1423 pr_cont("OK\n");
1424 }
1425
1426 /* Test with all events enabled */
1427
1428 pr_info("Running tests on all trace events:\n");
1429 pr_info("Testing all events: ");
1430
1431 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1432 if (WARN_ON_ONCE(ret)) {
1433 pr_warning("error enabling all events\n");
1434 return;
1435 }
1436
1437 event_test_stuff();
1438
1439 /* reset sysname */
1440 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1441 if (WARN_ON_ONCE(ret)) {
1442 pr_warning("error disabling all events\n");
1443 return;
1444 }
1445
1446 pr_cont("OK\n");
1447 }
1448
1449 #ifdef CONFIG_FUNCTION_TRACER
1450
1451 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1452
1453 static void
1454 function_test_events_call(unsigned long ip, unsigned long parent_ip)
1455 {
1456 struct ring_buffer_event *event;
1457 struct ring_buffer *buffer;
1458 struct ftrace_entry *entry;
1459 unsigned long flags;
1460 long disabled;
1461 int resched;
1462 int cpu;
1463 int pc;
1464
1465 pc = preempt_count();
1466 resched = ftrace_preempt_disable();
1467 cpu = raw_smp_processor_id();
1468 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1469
1470 if (disabled != 1)
1471 goto out;
1472
1473 local_save_flags(flags);
1474
1475 event = trace_current_buffer_lock_reserve(&buffer,
1476 TRACE_FN, sizeof(*entry),
1477 flags, pc);
1478 if (!event)
1479 goto out;
1480 entry = ring_buffer_event_data(event);
1481 entry->ip = ip;
1482 entry->parent_ip = parent_ip;
1483
1484 trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
1485
1486 out:
1487 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1488 ftrace_preempt_enable(resched);
1489 }
1490
1491 static struct ftrace_ops trace_ops __initdata =
1492 {
1493 .func = function_test_events_call,
1494 };
1495
1496 static __init void event_trace_self_test_with_function(void)
1497 {
1498 register_ftrace_function(&trace_ops);
1499 pr_info("Running tests again, along with the function tracer\n");
1500 event_trace_self_tests();
1501 unregister_ftrace_function(&trace_ops);
1502 }
1503 #else
1504 static __init void event_trace_self_test_with_function(void)
1505 {
1506 }
1507 #endif
1508
1509 static __init int event_trace_self_tests_init(void)
1510 {
1511 if (!tracing_selftest_disabled) {
1512 event_trace_self_tests();
1513 event_trace_self_test_with_function();
1514 }
1515
1516 return 0;
1517 }
1518
1519 late_initcall(event_trace_self_tests_init);
1520
1521 #endif
Linux kernel - Deliverables
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