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USB: gadget: s3c-hsotg: missing parentheses
[linux-2.6/linux-2.6-openrd.git] / kernel / trace / trace_events.c
blob6f03c8a1105e925f7604b7aaeac21e6486cb7c4f
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 #ifdef CONFIG_MODULES
97
98 static void trace_destroy_fields(struct ftrace_event_call *call)
99 {
100 struct ftrace_event_field *field, *next;
101
102 list_for_each_entry_safe(field, next, &call->fields, link) {
103 list_del(&field->link);
104 kfree(field->type);
105 kfree(field->name);
106 kfree(field);
107 }
108 }
109
110 #endif /* CONFIG_MODULES */
111
112 static void ftrace_event_enable_disable(struct ftrace_event_call *call,
113 int enable)
114 {
115 switch (enable) {
116 case 0:
117 if (call->enabled) {
118 call->enabled = 0;
119 tracing_stop_cmdline_record();
120 call->unregfunc(call->data);
121 }
122 break;
123 case 1:
124 if (!call->enabled) {
125 call->enabled = 1;
126 tracing_start_cmdline_record();
127 call->regfunc(call->data);
128 }
129 break;
130 }
131 }
132
133 static void ftrace_clear_events(void)
134 {
135 struct ftrace_event_call *call;
136
137 mutex_lock(&event_mutex);
138 list_for_each_entry(call, &ftrace_events, list) {
139 ftrace_event_enable_disable(call, 0);
140 }
141 mutex_unlock(&event_mutex);
142 }
143
144 /*
145 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
146 */
147 static int __ftrace_set_clr_event(const char *match, const char *sub,
148 const char *event, int set)
149 {
150 struct ftrace_event_call *call;
151 int ret = -EINVAL;
152
153 mutex_lock(&event_mutex);
154 list_for_each_entry(call, &ftrace_events, list) {
155
156 if (!call->name || !call->regfunc)
157 continue;
158
159 if (match &&
160 strcmp(match, call->name) != 0 &&
161 strcmp(match, call->system) != 0)
162 continue;
163
164 if (sub && strcmp(sub, call->system) != 0)
165 continue;
166
167 if (event && strcmp(event, call->name) != 0)
168 continue;
169
170 ftrace_event_enable_disable(call, set);
171
172 ret = 0;
173 }
174 mutex_unlock(&event_mutex);
175
176 return ret;
177 }
178
179 static int ftrace_set_clr_event(char *buf, int set)
180 {
181 char *event = NULL, *sub = NULL, *match;
182
183 /*
184 * The buf format can be <subsystem>:<event-name>
185 * *:<event-name> means any event by that name.
186 * :<event-name> is the same.
187 *
188 * <subsystem>:* means all events in that subsystem
189 * <subsystem>: means the same.
190 *
191 * <name> (no ':') means all events in a subsystem with
192 * the name <name> or any event that matches <name>
193 */
194
195 match = strsep(&buf, ":");
196 if (buf) {
197 sub = match;
198 event = buf;
199 match = NULL;
200
201 if (!strlen(sub) || strcmp(sub, "*") == 0)
202 sub = NULL;
203 if (!strlen(event) || strcmp(event, "*") == 0)
204 event = NULL;
205 }
206
207 return __ftrace_set_clr_event(match, sub, event, set);
208 }
209
210 /**
211 * trace_set_clr_event - enable or disable an event
212 * @system: system name to match (NULL for any system)
213 * @event: event name to match (NULL for all events, within system)
214 * @set: 1 to enable, 0 to disable
215 *
216 * This is a way for other parts of the kernel to enable or disable
217 * event recording.
218 *
219 * Returns 0 on success, -EINVAL if the parameters do not match any
220 * registered events.
221 */
222 int trace_set_clr_event(const char *system, const char *event, int set)
223 {
224 return __ftrace_set_clr_event(NULL, system, event, set);
225 }
226
227 /* 128 should be much more than enough */
228 #define EVENT_BUF_SIZE 127
229
230 static ssize_t
231 ftrace_event_write(struct file *file, const char __user *ubuf,
232 size_t cnt, loff_t *ppos)
233 {
234 struct trace_parser parser;
235 size_t read = 0;
236 ssize_t ret;
237
238 if (!cnt || cnt < 0)
239 return 0;
240
241 ret = tracing_update_buffers();
242 if (ret < 0)
243 return ret;
244
245 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
246 return -ENOMEM;
247
248 read = trace_get_user(&parser, ubuf, cnt, ppos);
249
250 if (trace_parser_loaded((&parser))) {
251 int set = 1;
252
253 if (*parser.buffer == '!')
254 set = 0;
255
256 parser.buffer[parser.idx] = 0;
257
258 ret = ftrace_set_clr_event(parser.buffer + !set, set);
259 if (ret)
260 goto out_put;
261 }
262
263 ret = read;
264
265 out_put:
266 trace_parser_put(&parser);
267
268 return ret;
269 }
270
271 static void *
272 t_next(struct seq_file *m, void *v, loff_t *pos)
273 {
274 struct ftrace_event_call *call = v;
275
276 (*pos)++;
277
278 list_for_each_entry_continue(call, &ftrace_events, list) {
279 /*
280 * The ftrace subsystem is for showing formats only.
281 * They can not be enabled or disabled via the event files.
282 */
283 if (call->regfunc)
284 return call;
285 }
286
287 return NULL;
288 }
289
290 static void *t_start(struct seq_file *m, loff_t *pos)
291 {
292 struct ftrace_event_call *call;
293 loff_t l;
294
295 mutex_lock(&event_mutex);
296
297 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
298 for (l = 0; l <= *pos; ) {
299 call = t_next(m, call, &l);
300 if (!call)
301 break;
302 }
303 return call;
304 }
305
306 static void *
307 s_next(struct seq_file *m, void *v, loff_t *pos)
308 {
309 struct ftrace_event_call *call = v;
310
311 (*pos)++;
312
313 list_for_each_entry_continue(call, &ftrace_events, list) {
314 if (call->enabled)
315 return call;
316 }
317
318 return NULL;
319 }
320
321 static void *s_start(struct seq_file *m, loff_t *pos)
322 {
323 struct ftrace_event_call *call;
324 loff_t l;
325
326 mutex_lock(&event_mutex);
327
328 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
329 for (l = 0; l <= *pos; ) {
330 call = s_next(m, call, &l);
331 if (!call)
332 break;
333 }
334 return call;
335 }
336
337 static int t_show(struct seq_file *m, void *v)
338 {
339 struct ftrace_event_call *call = v;
340
341 if (strcmp(call->system, TRACE_SYSTEM) != 0)
342 seq_printf(m, "%s:", call->system);
343 seq_printf(m, "%s\n", call->name);
344
345 return 0;
346 }
347
348 static void t_stop(struct seq_file *m, void *p)
349 {
350 mutex_unlock(&event_mutex);
351 }
352
353 static int
354 ftrace_event_seq_open(struct inode *inode, struct file *file)
355 {
356 const struct seq_operations *seq_ops;
357
358 if ((file->f_mode & FMODE_WRITE) &&
359 (file->f_flags & O_TRUNC))
360 ftrace_clear_events();
361
362 seq_ops = inode->i_private;
363 return seq_open(file, seq_ops);
364 }
365
366 static ssize_t
367 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
368 loff_t *ppos)
369 {
370 struct ftrace_event_call *call = filp->private_data;
371 char *buf;
372
373 if (call->enabled)
374 buf = "1\n";
375 else
376 buf = "0\n";
377
378 return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
379 }
380
381 static ssize_t
382 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
383 loff_t *ppos)
384 {
385 struct ftrace_event_call *call = filp->private_data;
386 char buf[64];
387 unsigned long val;
388 int ret;
389
390 if (cnt >= sizeof(buf))
391 return -EINVAL;
392
393 if (copy_from_user(&buf, ubuf, cnt))
394 return -EFAULT;
395
396 buf[cnt] = 0;
397
398 ret = strict_strtoul(buf, 10, &val);
399 if (ret < 0)
400 return ret;
401
402 ret = tracing_update_buffers();
403 if (ret < 0)
404 return ret;
405
406 switch (val) {
407 case 0:
408 case 1:
409 mutex_lock(&event_mutex);
410 ftrace_event_enable_disable(call, val);
411 mutex_unlock(&event_mutex);
412 break;
413
414 default:
415 return -EINVAL;
416 }
417
418 *ppos += cnt;
419
420 return cnt;
421 }
422
423 static ssize_t
424 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
425 loff_t *ppos)
426 {
427 const char set_to_char[4] = { '?', '0', '1', 'X' };
428 const char *system = filp->private_data;
429 struct ftrace_event_call *call;
430 char buf[2];
431 int set = 0;
432 int ret;
433
434 mutex_lock(&event_mutex);
435 list_for_each_entry(call, &ftrace_events, list) {
436 if (!call->name || !call->regfunc)
437 continue;
438
439 if (system && strcmp(call->system, system) != 0)
440 continue;
441
442 /*
443 * We need to find out if all the events are set
444 * or if all events or cleared, or if we have
445 * a mixture.
446 */
447 set |= (1 << !!call->enabled);
448
449 /*
450 * If we have a mixture, no need to look further.
451 */
452 if (set == 3)
453 break;
454 }
455 mutex_unlock(&event_mutex);
456
457 buf[0] = set_to_char[set];
458 buf[1] = '\n';
459
460 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
461
462 return ret;
463 }
464
465 static ssize_t
466 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
467 loff_t *ppos)
468 {
469 const char *system = filp->private_data;
470 unsigned long val;
471 char buf[64];
472 ssize_t ret;
473
474 if (cnt >= sizeof(buf))
475 return -EINVAL;
476
477 if (copy_from_user(&buf, ubuf, cnt))
478 return -EFAULT;
479
480 buf[cnt] = 0;
481
482 ret = strict_strtoul(buf, 10, &val);
483 if (ret < 0)
484 return ret;
485
486 ret = tracing_update_buffers();
487 if (ret < 0)
488 return ret;
489
490 if (val != 0 && val != 1)
491 return -EINVAL;
492
493 ret = __ftrace_set_clr_event(NULL, system, NULL, val);
494 if (ret)
495 goto out;
496
497 ret = cnt;
498
499 out:
500 *ppos += cnt;
501
502 return ret;
503 }
504
505 extern char *__bad_type_size(void);
506
507 #undef FIELD
508 #define FIELD(type, name) \
509 sizeof(type) != sizeof(field.name) ? __bad_type_size() : \
510 #type, "common_" #name, offsetof(typeof(field), name), \
511 sizeof(field.name)
512
513 static int trace_write_header(struct trace_seq *s)
514 {
515 struct trace_entry field;
516
517 /* struct trace_entry */
518 return trace_seq_printf(s,
519 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
520 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
521 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
522 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
523 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
524 "\n",
525 FIELD(unsigned short, type),
526 FIELD(unsigned char, flags),
527 FIELD(unsigned char, preempt_count),
528 FIELD(int, pid),
529 FIELD(int, lock_depth));
530 }
531
532 static ssize_t
533 event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
534 loff_t *ppos)
535 {
536 struct ftrace_event_call *call = filp->private_data;
537 struct trace_seq *s;
538 char *buf;
539 int r;
540
541 if (*ppos)
542 return 0;
543
544 s = kmalloc(sizeof(*s), GFP_KERNEL);
545 if (!s)
546 return -ENOMEM;
547
548 trace_seq_init(s);
549
550 /* If any of the first writes fail, so will the show_format. */
551
552 trace_seq_printf(s, "name: %s\n", call->name);
553 trace_seq_printf(s, "ID: %d\n", call->id);
554 trace_seq_printf(s, "format:\n");
555 trace_write_header(s);
556
557 r = call->show_format(call, s);
558 if (!r) {
559 /*
560 * ug! The format output is bigger than a PAGE!!
561 */
562 buf = "FORMAT TOO BIG\n";
563 r = simple_read_from_buffer(ubuf, cnt, ppos,
564 buf, strlen(buf));
565 goto out;
566 }
567
568 r = simple_read_from_buffer(ubuf, cnt, ppos,
569 s->buffer, s->len);
570 out:
571 kfree(s);
572 return r;
573 }
574
575 static ssize_t
576 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
577 {
578 struct ftrace_event_call *call = filp->private_data;
579 struct trace_seq *s;
580 int r;
581
582 if (*ppos)
583 return 0;
584
585 s = kmalloc(sizeof(*s), GFP_KERNEL);
586 if (!s)
587 return -ENOMEM;
588
589 trace_seq_init(s);
590 trace_seq_printf(s, "%d\n", call->id);
591
592 r = simple_read_from_buffer(ubuf, cnt, ppos,
593 s->buffer, s->len);
594 kfree(s);
595 return r;
596 }
597
598 static ssize_t
599 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
600 loff_t *ppos)
601 {
602 struct ftrace_event_call *call = filp->private_data;
603 struct trace_seq *s;
604 int r;
605
606 if (*ppos)
607 return 0;
608
609 s = kmalloc(sizeof(*s), GFP_KERNEL);
610 if (!s)
611 return -ENOMEM;
612
613 trace_seq_init(s);
614
615 print_event_filter(call, s);
616 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
617
618 kfree(s);
619
620 return r;
621 }
622
623 static ssize_t
624 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
625 loff_t *ppos)
626 {
627 struct ftrace_event_call *call = filp->private_data;
628 char *buf;
629 int err;
630
631 if (cnt >= PAGE_SIZE)
632 return -EINVAL;
633
634 buf = (char *)__get_free_page(GFP_TEMPORARY);
635 if (!buf)
636 return -ENOMEM;
637
638 if (copy_from_user(buf, ubuf, cnt)) {
639 free_page((unsigned long) buf);
640 return -EFAULT;
641 }
642 buf[cnt] = '\0';
643
644 err = apply_event_filter(call, buf);
645 free_page((unsigned long) buf);
646 if (err < 0)
647 return err;
648
649 *ppos += cnt;
650
651 return cnt;
652 }
653
654 static ssize_t
655 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
656 loff_t *ppos)
657 {
658 struct event_subsystem *system = filp->private_data;
659 struct trace_seq *s;
660 int r;
661
662 if (*ppos)
663 return 0;
664
665 s = kmalloc(sizeof(*s), GFP_KERNEL);
666 if (!s)
667 return -ENOMEM;
668
669 trace_seq_init(s);
670
671 print_subsystem_event_filter(system, s);
672 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
673
674 kfree(s);
675
676 return r;
677 }
678
679 static ssize_t
680 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
681 loff_t *ppos)
682 {
683 struct event_subsystem *system = filp->private_data;
684 char *buf;
685 int err;
686
687 if (cnt >= PAGE_SIZE)
688 return -EINVAL;
689
690 buf = (char *)__get_free_page(GFP_TEMPORARY);
691 if (!buf)
692 return -ENOMEM;
693
694 if (copy_from_user(buf, ubuf, cnt)) {
695 free_page((unsigned long) buf);
696 return -EFAULT;
697 }
698 buf[cnt] = '\0';
699
700 err = apply_subsystem_event_filter(system, buf);
701 free_page((unsigned long) buf);
702 if (err < 0)
703 return err;
704
705 *ppos += cnt;
706
707 return cnt;
708 }
709
710 static ssize_t
711 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
712 {
713 int (*func)(struct trace_seq *s) = filp->private_data;
714 struct trace_seq *s;
715 int r;
716
717 if (*ppos)
718 return 0;
719
720 s = kmalloc(sizeof(*s), GFP_KERNEL);
721 if (!s)
722 return -ENOMEM;
723
724 trace_seq_init(s);
725
726 func(s);
727 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
728
729 kfree(s);
730
731 return r;
732 }
733
734 static const struct seq_operations show_event_seq_ops = {
735 .start = t_start,
736 .next = t_next,
737 .show = t_show,
738 .stop = t_stop,
739 };
740
741 static const struct seq_operations show_set_event_seq_ops = {
742 .start = s_start,
743 .next = s_next,
744 .show = t_show,
745 .stop = t_stop,
746 };
747
748 static const struct file_operations ftrace_avail_fops = {
749 .open = ftrace_event_seq_open,
750 .read = seq_read,
751 .llseek = seq_lseek,
752 .release = seq_release,
753 };
754
755 static const struct file_operations ftrace_set_event_fops = {
756 .open = ftrace_event_seq_open,
757 .read = seq_read,
758 .write = ftrace_event_write,
759 .llseek = seq_lseek,
760 .release = seq_release,
761 };
762
763 static const struct file_operations ftrace_enable_fops = {
764 .open = tracing_open_generic,
765 .read = event_enable_read,
766 .write = event_enable_write,
767 };
768
769 static const struct file_operations ftrace_event_format_fops = {
770 .open = tracing_open_generic,
771 .read = event_format_read,
772 };
773
774 static const struct file_operations ftrace_event_id_fops = {
775 .open = tracing_open_generic,
776 .read = event_id_read,
777 };
778
779 static const struct file_operations ftrace_event_filter_fops = {
780 .open = tracing_open_generic,
781 .read = event_filter_read,
782 .write = event_filter_write,
783 };
784
785 static const struct file_operations ftrace_subsystem_filter_fops = {
786 .open = tracing_open_generic,
787 .read = subsystem_filter_read,
788 .write = subsystem_filter_write,
789 };
790
791 static const struct file_operations ftrace_system_enable_fops = {
792 .open = tracing_open_generic,
793 .read = system_enable_read,
794 .write = system_enable_write,
795 };
796
797 static const struct file_operations ftrace_show_header_fops = {
798 .open = tracing_open_generic,
799 .read = show_header,
800 };
801
802 static struct dentry *event_trace_events_dir(void)
803 {
804 static struct dentry *d_tracer;
805 static struct dentry *d_events;
806
807 if (d_events)
808 return d_events;
809
810 d_tracer = tracing_init_dentry();
811 if (!d_tracer)
812 return NULL;
813
814 d_events = debugfs_create_dir("events", d_tracer);
815 if (!d_events)
816 pr_warning("Could not create debugfs "
817 "'events' directory\n");
818
819 return d_events;
820 }
821
822 static LIST_HEAD(event_subsystems);
823
824 static struct dentry *
825 event_subsystem_dir(const char *name, struct dentry *d_events)
826 {
827 struct event_subsystem *system;
828 struct dentry *entry;
829
830 /* First see if we did not already create this dir */
831 list_for_each_entry(system, &event_subsystems, list) {
832 if (strcmp(system->name, name) == 0) {
833 system->nr_events++;
834 return system->entry;
835 }
836 }
837
838 /* need to create new entry */
839 system = kmalloc(sizeof(*system), GFP_KERNEL);
840 if (!system) {
841 pr_warning("No memory to create event subsystem %s\n",
842 name);
843 return d_events;
844 }
845
846 system->entry = debugfs_create_dir(name, d_events);
847 if (!system->entry) {
848 pr_warning("Could not create event subsystem %s\n",
849 name);
850 kfree(system);
851 return d_events;
852 }
853
854 system->nr_events = 1;
855 system->name = kstrdup(name, GFP_KERNEL);
856 if (!system->name) {
857 debugfs_remove(system->entry);
858 kfree(system);
859 return d_events;
860 }
861
862 list_add(&system->list, &event_subsystems);
863
864 system->filter = NULL;
865
866 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
867 if (!system->filter) {
868 pr_warning("Could not allocate filter for subsystem "
869 "'%s'\n", name);
870 return system->entry;
871 }
872
873 entry = debugfs_create_file("filter", 0644, system->entry, system,
874 &ftrace_subsystem_filter_fops);
875 if (!entry) {
876 kfree(system->filter);
877 system->filter = NULL;
878 pr_warning("Could not create debugfs "
879 "'%s/filter' entry\n", name);
880 }
881
882 entry = trace_create_file("enable", 0644, system->entry,
883 (void *)system->name,
884 &ftrace_system_enable_fops);
885
886 return system->entry;
887 }
888
889 static int
890 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
891 const struct file_operations *id,
892 const struct file_operations *enable,
893 const struct file_operations *filter,
894 const struct file_operations *format)
895 {
896 struct dentry *entry;
897 int ret;
898
899 /*
900 * If the trace point header did not define TRACE_SYSTEM
901 * then the system would be called "TRACE_SYSTEM".
902 */
903 if (strcmp(call->system, TRACE_SYSTEM) != 0)
904 d_events = event_subsystem_dir(call->system, d_events);
905
906 call->dir = debugfs_create_dir(call->name, d_events);
907 if (!call->dir) {
908 pr_warning("Could not create debugfs "
909 "'%s' directory\n", call->name);
910 return -1;
911 }
912
913 if (call->regfunc)
914 entry = trace_create_file("enable", 0644, call->dir, call,
915 enable);
916
917 if (call->id && call->profile_enable)
918 entry = trace_create_file("id", 0444, call->dir, call,
919 id);
920
921 if (call->define_fields) {
922 ret = call->define_fields(call);
923 if (ret < 0) {
924 pr_warning("Could not initialize trace point"
925 " events/%s\n", call->name);
926 return ret;
927 }
928 entry = trace_create_file("filter", 0644, call->dir, call,
929 filter);
930 }
931
932 /* A trace may not want to export its format */
933 if (!call->show_format)
934 return 0;
935
936 entry = trace_create_file("format", 0444, call->dir, call,
937 format);
938
939 return 0;
940 }
941
942 #define for_each_event(event, start, end) \
943 for (event = start; \
944 (unsigned long)event < (unsigned long)end; \
945 event++)
946
947 #ifdef CONFIG_MODULES
948
949 static LIST_HEAD(ftrace_module_file_list);
950
951 /*
952 * Modules must own their file_operations to keep up with
953 * reference counting.
954 */
955 struct ftrace_module_file_ops {
956 struct list_head list;
957 struct module *mod;
958 struct file_operations id;
959 struct file_operations enable;
960 struct file_operations format;
961 struct file_operations filter;
962 };
963
964 static void remove_subsystem_dir(const char *name)
965 {
966 struct event_subsystem *system;
967
968 if (strcmp(name, TRACE_SYSTEM) == 0)
969 return;
970
971 list_for_each_entry(system, &event_subsystems, list) {
972 if (strcmp(system->name, name) == 0) {
973 if (!--system->nr_events) {
974 struct event_filter *filter = system->filter;
975
976 debugfs_remove_recursive(system->entry);
977 list_del(&system->list);
978 if (filter) {
979 kfree(filter->filter_string);
980 kfree(filter);
981 }
982 kfree(system->name);
983 kfree(system);
984 }
985 break;
986 }
987 }
988 }
989
990 static struct ftrace_module_file_ops *
991 trace_create_file_ops(struct module *mod)
992 {
993 struct ftrace_module_file_ops *file_ops;
994
995 /*
996 * This is a bit of a PITA. To allow for correct reference
997 * counting, modules must "own" their file_operations.
998 * To do this, we allocate the file operations that will be
999 * used in the event directory.
1000 */
1001
1002 file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1003 if (!file_ops)
1004 return NULL;
1005
1006 file_ops->mod = mod;
1007
1008 file_ops->id = ftrace_event_id_fops;
1009 file_ops->id.owner = mod;
1010
1011 file_ops->enable = ftrace_enable_fops;
1012 file_ops->enable.owner = mod;
1013
1014 file_ops->filter = ftrace_event_filter_fops;
1015 file_ops->filter.owner = mod;
1016
1017 file_ops->format = ftrace_event_format_fops;
1018 file_ops->format.owner = mod;
1019
1020 list_add(&file_ops->list, &ftrace_module_file_list);
1021
1022 return file_ops;
1023 }
1024
1025 static void trace_module_add_events(struct module *mod)
1026 {
1027 struct ftrace_module_file_ops *file_ops = NULL;
1028 struct ftrace_event_call *call, *start, *end;
1029 struct dentry *d_events;
1030 int ret;
1031
1032 start = mod->trace_events;
1033 end = mod->trace_events + mod->num_trace_events;
1034
1035 if (start == end)
1036 return;
1037
1038 d_events = event_trace_events_dir();
1039 if (!d_events)
1040 return;
1041
1042 for_each_event(call, start, end) {
1043 /* The linker may leave blanks */
1044 if (!call->name)
1045 continue;
1046 if (call->raw_init) {
1047 ret = call->raw_init();
1048 if (ret < 0) {
1049 if (ret != -ENOSYS)
1050 pr_warning("Could not initialize trace "
1051 "point events/%s\n", call->name);
1052 continue;
1053 }
1054 }
1055 /*
1056 * This module has events, create file ops for this module
1057 * if not already done.
1058 */
1059 if (!file_ops) {
1060 file_ops = trace_create_file_ops(mod);
1061 if (!file_ops)
1062 return;
1063 }
1064 call->mod = mod;
1065 list_add(&call->list, &ftrace_events);
1066 event_create_dir(call, d_events,
1067 &file_ops->id, &file_ops->enable,
1068 &file_ops->filter, &file_ops->format);
1069 }
1070 }
1071
1072 static void trace_module_remove_events(struct module *mod)
1073 {
1074 struct ftrace_module_file_ops *file_ops;
1075 struct ftrace_event_call *call, *p;
1076 bool found = false;
1077
1078 down_write(&trace_event_mutex);
1079 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1080 if (call->mod == mod) {
1081 found = true;
1082 ftrace_event_enable_disable(call, 0);
1083 if (call->event)
1084 __unregister_ftrace_event(call->event);
1085 debugfs_remove_recursive(call->dir);
1086 list_del(&call->list);
1087 trace_destroy_fields(call);
1088 destroy_preds(call);
1089 remove_subsystem_dir(call->system);
1090 }
1091 }
1092
1093 /* Now free the file_operations */
1094 list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1095 if (file_ops->mod == mod)
1096 break;
1097 }
1098 if (&file_ops->list != &ftrace_module_file_list) {
1099 list_del(&file_ops->list);
1100 kfree(file_ops);
1101 }
1102
1103 /*
1104 * It is safest to reset the ring buffer if the module being unloaded
1105 * registered any events.
1106 */
1107 if (found)
1108 tracing_reset_current_online_cpus();
1109 up_write(&trace_event_mutex);
1110 }
1111
1112 static int trace_module_notify(struct notifier_block *self,
1113 unsigned long val, void *data)
1114 {
1115 struct module *mod = data;
1116
1117 mutex_lock(&event_mutex);
1118 switch (val) {
1119 case MODULE_STATE_COMING:
1120 trace_module_add_events(mod);
1121 break;
1122 case MODULE_STATE_GOING:
1123 trace_module_remove_events(mod);
1124 break;
1125 }
1126 mutex_unlock(&event_mutex);
1127
1128 return 0;
1129 }
1130 #else
1131 static int trace_module_notify(struct notifier_block *self,
1132 unsigned long val, void *data)
1133 {
1134 return 0;
1135 }
1136 #endif /* CONFIG_MODULES */
1137
1138 static struct notifier_block trace_module_nb = {
1139 .notifier_call = trace_module_notify,
1140 .priority = 0,
1141 };
1142
1143 extern struct ftrace_event_call __start_ftrace_events[];
1144 extern struct ftrace_event_call __stop_ftrace_events[];
1145
1146 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1147
1148 static __init int setup_trace_event(char *str)
1149 {
1150 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1151 ring_buffer_expanded = 1;
1152 tracing_selftest_disabled = 1;
1153
1154 return 1;
1155 }
1156 __setup("trace_event=", setup_trace_event);
1157
1158 static __init int event_trace_init(void)
1159 {
1160 struct ftrace_event_call *call;
1161 struct dentry *d_tracer;
1162 struct dentry *entry;
1163 struct dentry *d_events;
1164 int ret;
1165 char *buf = bootup_event_buf;
1166 char *token;
1167
1168 d_tracer = tracing_init_dentry();
1169 if (!d_tracer)
1170 return 0;
1171
1172 entry = debugfs_create_file("available_events", 0444, d_tracer,
1173 (void *)&show_event_seq_ops,
1174 &ftrace_avail_fops);
1175 if (!entry)
1176 pr_warning("Could not create debugfs "
1177 "'available_events' entry\n");
1178
1179 entry = debugfs_create_file("set_event", 0644, d_tracer,
1180 (void *)&show_set_event_seq_ops,
1181 &ftrace_set_event_fops);
1182 if (!entry)
1183 pr_warning("Could not create debugfs "
1184 "'set_event' entry\n");
1185
1186 d_events = event_trace_events_dir();
1187 if (!d_events)
1188 return 0;
1189
1190 /* ring buffer internal formats */
1191 trace_create_file("header_page", 0444, d_events,
1192 ring_buffer_print_page_header,
1193 &ftrace_show_header_fops);
1194
1195 trace_create_file("header_event", 0444, d_events,
1196 ring_buffer_print_entry_header,
1197 &ftrace_show_header_fops);
1198
1199 trace_create_file("enable", 0644, d_events,
1200 NULL, &ftrace_system_enable_fops);
1201
1202 for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
1203 /* The linker may leave blanks */
1204 if (!call->name)
1205 continue;
1206 if (call->raw_init) {
1207 ret = call->raw_init();
1208 if (ret < 0) {
1209 if (ret != -ENOSYS)
1210 pr_warning("Could not initialize trace "
1211 "point events/%s\n", call->name);
1212 continue;
1213 }
1214 }
1215 list_add(&call->list, &ftrace_events);
1216 event_create_dir(call, d_events, &ftrace_event_id_fops,
1217 &ftrace_enable_fops, &ftrace_event_filter_fops,
1218 &ftrace_event_format_fops);
1219 }
1220
1221 while (true) {
1222 token = strsep(&buf, ",");
1223
1224 if (!token)
1225 break;
1226 if (!*token)
1227 continue;
1228
1229 ret = ftrace_set_clr_event(token, 1);
1230 if (ret)
1231 pr_warning("Failed to enable trace event: %s\n", token);
1232 }
1233
1234 ret = register_module_notifier(&trace_module_nb);
1235 if (ret)
1236 pr_warning("Failed to register trace events module notifier\n");
1237
1238 return 0;
1239 }
1240 fs_initcall(event_trace_init);
1241
1242 #ifdef CONFIG_FTRACE_STARTUP_TEST
1243
1244 static DEFINE_SPINLOCK(test_spinlock);
1245 static DEFINE_SPINLOCK(test_spinlock_irq);
1246 static DEFINE_MUTEX(test_mutex);
1247
1248 static __init void test_work(struct work_struct *dummy)
1249 {
1250 spin_lock(&test_spinlock);
1251 spin_lock_irq(&test_spinlock_irq);
1252 udelay(1);
1253 spin_unlock_irq(&test_spinlock_irq);
1254 spin_unlock(&test_spinlock);
1255
1256 mutex_lock(&test_mutex);
1257 msleep(1);
1258 mutex_unlock(&test_mutex);
1259 }
1260
1261 static __init int event_test_thread(void *unused)
1262 {
1263 void *test_malloc;
1264
1265 test_malloc = kmalloc(1234, GFP_KERNEL);
1266 if (!test_malloc)
1267 pr_info("failed to kmalloc\n");
1268
1269 schedule_on_each_cpu(test_work);
1270
1271 kfree(test_malloc);
1272
1273 set_current_state(TASK_INTERRUPTIBLE);
1274 while (!kthread_should_stop())
1275 schedule();
1276
1277 return 0;
1278 }
1279
1280 /*
1281 * Do various things that may trigger events.
1282 */
1283 static __init void event_test_stuff(void)
1284 {
1285 struct task_struct *test_thread;
1286
1287 test_thread = kthread_run(event_test_thread, NULL, "test-events");
1288 msleep(1);
1289 kthread_stop(test_thread);
1290 }
1291
1292 /*
1293 * For every trace event defined, we will test each trace point separately,
1294 * and then by groups, and finally all trace points.
1295 */
1296 static __init void event_trace_self_tests(void)
1297 {
1298 struct ftrace_event_call *call;
1299 struct event_subsystem *system;
1300 int ret;
1301
1302 pr_info("Running tests on trace events:\n");
1303
1304 list_for_each_entry(call, &ftrace_events, list) {
1305
1306 /* Only test those that have a regfunc */
1307 if (!call->regfunc)
1308 continue;
1309
1310 /*
1311 * Testing syscall events here is pretty useless, but
1312 * we still do it if configured. But this is time consuming.
1313 * What we really need is a user thread to perform the
1314 * syscalls as we test.
1315 */
1316 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1317 if (call->system &&
1318 strcmp(call->system, "syscalls") == 0)
1319 continue;
1320 #endif
1321
1322 pr_info("Testing event %s: ", call->name);
1323
1324 /*
1325 * If an event is already enabled, someone is using
1326 * it and the self test should not be on.
1327 */
1328 if (call->enabled) {
1329 pr_warning("Enabled event during self test!\n");
1330 WARN_ON_ONCE(1);
1331 continue;
1332 }
1333
1334 ftrace_event_enable_disable(call, 1);
1335 event_test_stuff();
1336 ftrace_event_enable_disable(call, 0);
1337
1338 pr_cont("OK\n");
1339 }
1340
1341 /* Now test at the sub system level */
1342
1343 pr_info("Running tests on trace event systems:\n");
1344
1345 list_for_each_entry(system, &event_subsystems, list) {
1346
1347 /* the ftrace system is special, skip it */
1348 if (strcmp(system->name, "ftrace") == 0)
1349 continue;
1350
1351 pr_info("Testing event system %s: ", system->name);
1352
1353 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1354 if (WARN_ON_ONCE(ret)) {
1355 pr_warning("error enabling system %s\n",
1356 system->name);
1357 continue;
1358 }
1359
1360 event_test_stuff();
1361
1362 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1363 if (WARN_ON_ONCE(ret))
1364 pr_warning("error disabling system %s\n",
1365 system->name);
1366
1367 pr_cont("OK\n");
1368 }
1369
1370 /* Test with all events enabled */
1371
1372 pr_info("Running tests on all trace events:\n");
1373 pr_info("Testing all events: ");
1374
1375 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1376 if (WARN_ON_ONCE(ret)) {
1377 pr_warning("error enabling all events\n");
1378 return;
1379 }
1380
1381 event_test_stuff();
1382
1383 /* reset sysname */
1384 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1385 if (WARN_ON_ONCE(ret)) {
1386 pr_warning("error disabling all events\n");
1387 return;
1388 }
1389
1390 pr_cont("OK\n");
1391 }
1392
1393 #ifdef CONFIG_FUNCTION_TRACER
1394
1395 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1396
1397 static void
1398 function_test_events_call(unsigned long ip, unsigned long parent_ip)
1399 {
1400 struct ring_buffer_event *event;
1401 struct ring_buffer *buffer;
1402 struct ftrace_entry *entry;
1403 unsigned long flags;
1404 long disabled;
1405 int resched;
1406 int cpu;
1407 int pc;
1408
1409 pc = preempt_count();
1410 resched = ftrace_preempt_disable();
1411 cpu = raw_smp_processor_id();
1412 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1413
1414 if (disabled != 1)
1415 goto out;
1416
1417 local_save_flags(flags);
1418
1419 event = trace_current_buffer_lock_reserve(&buffer,
1420 TRACE_FN, sizeof(*entry),
1421 flags, pc);
1422 if (!event)
1423 goto out;
1424 entry = ring_buffer_event_data(event);
1425 entry->ip = ip;
1426 entry->parent_ip = parent_ip;
1427
1428 trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
1429
1430 out:
1431 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1432 ftrace_preempt_enable(resched);
1433 }
1434
1435 static struct ftrace_ops trace_ops __initdata =
1436 {
1437 .func = function_test_events_call,
1438 };
1439
1440 static __init void event_trace_self_test_with_function(void)
1441 {
1442 register_ftrace_function(&trace_ops);
1443 pr_info("Running tests again, along with the function tracer\n");
1444 event_trace_self_tests();
1445 unregister_ftrace_function(&trace_ops);
1446 }
1447 #else
1448 static __init void event_trace_self_test_with_function(void)
1449 {
1450 }
1451 #endif
1452
1453 static __init int event_trace_self_tests_init(void)
1454 {
1455 if (!tracing_selftest_disabled) {
1456 event_trace_self_tests();
1457 event_trace_self_test_with_function();
1458 }
1459
1460 return 0;
1461 }
1462
1463 late_initcall(event_trace_self_tests_init);
1464
1465 #endif
linux 2.6 git repository for openrd