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authorLinus Torvalds <torvalds@linux-foundation.org>2009-04-05 14:04:19 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-04-05 14:04:19 -0400
commit714f83d5d9f7c785f622259dad1f4fad12d64664 (patch)
tree20563541ae438e11d686b4d629074eb002a481b7 /kernel/trace/trace_events.c
parent8901e7ffc2fa78ede7ce9826dbad68a3a25dc2dc (diff)
parent645dae969c3b8651c5bc7c54a1835ec03820f85f (diff)
Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits) tracing, net: fix net tree and tracing tree merge interaction tracing, powerpc: fix powerpc tree and tracing tree interaction ring-buffer: do not remove reader page from list on ring buffer free function-graph: allow unregistering twice trace: make argument 'mem' of trace_seq_putmem() const tracing: add missing 'extern' keywords to trace_output.h tracing: provide trace_seq_reserve() blktrace: print out BLK_TN_MESSAGE properly blktrace: extract duplidate code blktrace: fix memory leak when freeing struct blk_io_trace blktrace: fix blk_probes_ref chaos blktrace: make classic output more classic blktrace: fix off-by-one bug blktrace: fix the original blktrace blktrace: fix a race when creating blk_tree_root in debugfs blktrace: fix timestamp in binary output tracing, Text Edit Lock: cleanup tracing: filter fix for TRACE_EVENT_FORMAT events ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release() x86: kretprobe-booster interrupt emulation code fix ... Fix up trivial conflicts in arch/parisc/include/asm/ftrace.h include/linux/memory.h kernel/extable.c kernel/module.c
Diffstat (limited to 'kernel/trace/trace_events.c')
-rw-r--r--kernel/trace/trace_events.c824
1 files changed, 824 insertions, 0 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
new file mode 100644
index 000000000000..64ec4d278ffb
--- /dev/null
+++ b/kernel/trace/trace_events.c
@@ -0,0 +1,824 @@
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/debugfs.h>
12#include <linux/uaccess.h>
13#include <linux/module.h>
14#include <linux/ctype.h>
15
16#include "trace_output.h"
17
18#define TRACE_SYSTEM "TRACE_SYSTEM"
19
20static DEFINE_MUTEX(event_mutex);
21
22int trace_define_field(struct ftrace_event_call *call, char *type,
23 char *name, int offset, int size)
24{
25 struct ftrace_event_field *field;
26
27 field = kzalloc(sizeof(*field), GFP_KERNEL);
28 if (!field)
29 goto err;
30
31 field->name = kstrdup(name, GFP_KERNEL);
32 if (!field->name)
33 goto err;
34
35 field->type = kstrdup(type, GFP_KERNEL);
36 if (!field->type)
37 goto err;
38
39 field->offset = offset;
40 field->size = size;
41 list_add(&field->link, &call->fields);
42
43 return 0;
44
45err:
46 if (field) {
47 kfree(field->name);
48 kfree(field->type);
49 }
50 kfree(field);
51
52 return -ENOMEM;
53}
54
55static void ftrace_clear_events(void)
56{
57 struct ftrace_event_call *call = (void *)__start_ftrace_events;
58
59
60 while ((unsigned long)call < (unsigned long)__stop_ftrace_events) {
61
62 if (call->enabled) {
63 call->enabled = 0;
64 call->unregfunc();
65 }
66 call++;
67 }
68}
69
70static void ftrace_event_enable_disable(struct ftrace_event_call *call,
71 int enable)
72{
73
74 switch (enable) {
75 case 0:
76 if (call->enabled) {
77 call->enabled = 0;
78 call->unregfunc();
79 }
80 break;
81 case 1:
82 if (!call->enabled) {
83 call->enabled = 1;
84 call->regfunc();
85 }
86 break;
87 }
88}
89
90static int ftrace_set_clr_event(char *buf, int set)
91{
92 struct ftrace_event_call *call = __start_ftrace_events;
93 char *event = NULL, *sub = NULL, *match;
94 int ret = -EINVAL;
95
96 /*
97 * The buf format can be <subsystem>:<event-name>
98 * *:<event-name> means any event by that name.
99 * :<event-name> is the same.
100 *
101 * <subsystem>:* means all events in that subsystem
102 * <subsystem>: means the same.
103 *
104 * <name> (no ':') means all events in a subsystem with
105 * the name <name> or any event that matches <name>
106 */
107
108 match = strsep(&buf, ":");
109 if (buf) {
110 sub = match;
111 event = buf;
112 match = NULL;
113
114 if (!strlen(sub) || strcmp(sub, "*") == 0)
115 sub = NULL;
116 if (!strlen(event) || strcmp(event, "*") == 0)
117 event = NULL;
118 }
119
120 mutex_lock(&event_mutex);
121 for_each_event(call) {
122
123 if (!call->name || !call->regfunc)
124 continue;
125
126 if (match &&
127 strcmp(match, call->name) != 0 &&
128 strcmp(match, call->system) != 0)
129 continue;
130
131 if (sub && strcmp(sub, call->system) != 0)
132 continue;
133
134 if (event && strcmp(event, call->name) != 0)
135 continue;
136
137 ftrace_event_enable_disable(call, set);
138
139 ret = 0;
140 }
141 mutex_unlock(&event_mutex);
142
143 return ret;
144}
145
146/* 128 should be much more than enough */
147#define EVENT_BUF_SIZE 127
148
149static ssize_t
150ftrace_event_write(struct file *file, const char __user *ubuf,
151 size_t cnt, loff_t *ppos)
152{
153 size_t read = 0;
154 int i, set = 1;
155 ssize_t ret;
156 char *buf;
157 char ch;
158
159 if (!cnt || cnt < 0)
160 return 0;
161
162 ret = tracing_update_buffers();
163 if (ret < 0)
164 return ret;
165
166 ret = get_user(ch, ubuf++);
167 if (ret)
168 return ret;
169 read++;
170 cnt--;
171
172 /* skip white space */
173 while (cnt && isspace(ch)) {
174 ret = get_user(ch, ubuf++);
175 if (ret)
176 return ret;
177 read++;
178 cnt--;
179 }
180
181 /* Only white space found? */
182 if (isspace(ch)) {
183 file->f_pos += read;
184 ret = read;
185 return ret;
186 }
187
188 buf = kmalloc(EVENT_BUF_SIZE+1, GFP_KERNEL);
189 if (!buf)
190 return -ENOMEM;
191
192 if (cnt > EVENT_BUF_SIZE)
193 cnt = EVENT_BUF_SIZE;
194
195 i = 0;
196 while (cnt && !isspace(ch)) {
197 if (!i && ch == '!')
198 set = 0;
199 else
200 buf[i++] = ch;
201
202 ret = get_user(ch, ubuf++);
203 if (ret)
204 goto out_free;
205 read++;
206 cnt--;
207 }
208 buf[i] = 0;
209
210 file->f_pos += read;
211
212 ret = ftrace_set_clr_event(buf, set);
213 if (ret)
214 goto out_free;
215
216 ret = read;
217
218 out_free:
219 kfree(buf);
220
221 return ret;
222}
223
224static void *
225t_next(struct seq_file *m, void *v, loff_t *pos)
226{
227 struct ftrace_event_call *call = m->private;
228 struct ftrace_event_call *next = call;
229
230 (*pos)++;
231
232 for (;;) {
233 if ((unsigned long)call >= (unsigned long)__stop_ftrace_events)
234 return NULL;
235
236 /*
237 * The ftrace subsystem is for showing formats only.
238 * They can not be enabled or disabled via the event files.
239 */
240 if (call->regfunc)
241 break;
242
243 call++;
244 next = call;
245 }
246
247 m->private = ++next;
248
249 return call;
250}
251
252static void *t_start(struct seq_file *m, loff_t *pos)
253{
254 return t_next(m, NULL, pos);
255}
256
257static void *
258s_next(struct seq_file *m, void *v, loff_t *pos)
259{
260 struct ftrace_event_call *call = m->private;
261 struct ftrace_event_call *next;
262
263 (*pos)++;
264
265 retry:
266 if ((unsigned long)call >= (unsigned long)__stop_ftrace_events)
267 return NULL;
268
269 if (!call->enabled) {
270 call++;
271 goto retry;
272 }
273
274 next = call;
275 m->private = ++next;
276
277 return call;
278}
279
280static void *s_start(struct seq_file *m, loff_t *pos)
281{
282 return s_next(m, NULL, pos);
283}
284
285static int t_show(struct seq_file *m, void *v)
286{
287 struct ftrace_event_call *call = v;
288
289 if (strcmp(call->system, TRACE_SYSTEM) != 0)
290 seq_printf(m, "%s:", call->system);
291 seq_printf(m, "%s\n", call->name);
292
293 return 0;
294}
295
296static void t_stop(struct seq_file *m, void *p)
297{
298}
299
300static int
301ftrace_event_seq_open(struct inode *inode, struct file *file)
302{
303 int ret;
304 const struct seq_operations *seq_ops;
305
306 if ((file->f_mode & FMODE_WRITE) &&
307 !(file->f_flags & O_APPEND))
308 ftrace_clear_events();
309
310 seq_ops = inode->i_private;
311 ret = seq_open(file, seq_ops);
312 if (!ret) {
313 struct seq_file *m = file->private_data;
314
315 m->private = __start_ftrace_events;
316 }
317 return ret;
318}
319
320static ssize_t
321event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
322 loff_t *ppos)
323{
324 struct ftrace_event_call *call = filp->private_data;
325 char *buf;
326
327 if (call->enabled)
328 buf = "1\n";
329 else
330 buf = "0\n";
331
332 return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
333}
334
335static ssize_t
336event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
337 loff_t *ppos)
338{
339 struct ftrace_event_call *call = filp->private_data;
340 char buf[64];
341 unsigned long val;
342 int ret;
343
344 if (cnt >= sizeof(buf))
345 return -EINVAL;
346
347 if (copy_from_user(&buf, ubuf, cnt))
348 return -EFAULT;
349
350 buf[cnt] = 0;
351
352 ret = strict_strtoul(buf, 10, &val);
353 if (ret < 0)
354 return ret;
355
356 ret = tracing_update_buffers();
357 if (ret < 0)
358 return ret;
359
360 switch (val) {
361 case 0:
362 case 1:
363 mutex_lock(&event_mutex);
364 ftrace_event_enable_disable(call, val);
365 mutex_unlock(&event_mutex);
366 break;
367
368 default:
369 return -EINVAL;
370 }
371
372 *ppos += cnt;
373
374 return cnt;
375}
376
377#undef FIELD
378#define FIELD(type, name) \
379 #type, "common_" #name, offsetof(typeof(field), name), \
380 sizeof(field.name)
381
382static int trace_write_header(struct trace_seq *s)
383{
384 struct trace_entry field;
385
386 /* struct trace_entry */
387 return trace_seq_printf(s,
388 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
389 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
390 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
391 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
392 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
393 "\n",
394 FIELD(unsigned char, type),
395 FIELD(unsigned char, flags),
396 FIELD(unsigned char, preempt_count),
397 FIELD(int, pid),
398 FIELD(int, tgid));
399}
400
401static ssize_t
402event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
403 loff_t *ppos)
404{
405 struct ftrace_event_call *call = filp->private_data;
406 struct trace_seq *s;
407 char *buf;
408 int r;
409
410 if (*ppos)
411 return 0;
412
413 s = kmalloc(sizeof(*s), GFP_KERNEL);
414 if (!s)
415 return -ENOMEM;
416
417 trace_seq_init(s);
418
419 /* If any of the first writes fail, so will the show_format. */
420
421 trace_seq_printf(s, "name: %s\n", call->name);
422 trace_seq_printf(s, "ID: %d\n", call->id);
423 trace_seq_printf(s, "format:\n");
424 trace_write_header(s);
425
426 r = call->show_format(s);
427 if (!r) {
428 /*
429 * ug! The format output is bigger than a PAGE!!
430 */
431 buf = "FORMAT TOO BIG\n";
432 r = simple_read_from_buffer(ubuf, cnt, ppos,
433 buf, strlen(buf));
434 goto out;
435 }
436
437 r = simple_read_from_buffer(ubuf, cnt, ppos,
438 s->buffer, s->len);
439 out:
440 kfree(s);
441 return r;
442}
443
444static ssize_t
445event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
446{
447 struct ftrace_event_call *call = filp->private_data;
448 struct trace_seq *s;
449 int r;
450
451 if (*ppos)
452 return 0;
453
454 s = kmalloc(sizeof(*s), GFP_KERNEL);
455 if (!s)
456 return -ENOMEM;
457
458 trace_seq_init(s);
459 trace_seq_printf(s, "%d\n", call->id);
460
461 r = simple_read_from_buffer(ubuf, cnt, ppos,
462 s->buffer, s->len);
463 kfree(s);
464 return r;
465}
466
467static ssize_t
468event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
469 loff_t *ppos)
470{
471 struct ftrace_event_call *call = filp->private_data;
472 struct trace_seq *s;
473 int r;
474
475 if (*ppos)
476 return 0;
477
478 s = kmalloc(sizeof(*s), GFP_KERNEL);
479 if (!s)
480 return -ENOMEM;
481
482 trace_seq_init(s);
483
484 filter_print_preds(call->preds, s);
485 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
486
487 kfree(s);
488
489 return r;
490}
491
492static ssize_t
493event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
494 loff_t *ppos)
495{
496 struct ftrace_event_call *call = filp->private_data;
497 char buf[64], *pbuf = buf;
498 struct filter_pred *pred;
499 int err;
500
501 if (cnt >= sizeof(buf))
502 return -EINVAL;
503
504 if (copy_from_user(&buf, ubuf, cnt))
505 return -EFAULT;
506
507 pred = kzalloc(sizeof(*pred), GFP_KERNEL);
508 if (!pred)
509 return -ENOMEM;
510
511 err = filter_parse(&pbuf, pred);
512 if (err < 0) {
513 filter_free_pred(pred);
514 return err;
515 }
516
517 if (pred->clear) {
518 filter_free_preds(call);
519 filter_free_pred(pred);
520 return cnt;
521 }
522
523 if (filter_add_pred(call, pred)) {
524 filter_free_pred(pred);
525 return -EINVAL;
526 }
527
528 *ppos += cnt;
529
530 return cnt;
531}
532
533static ssize_t
534subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
535 loff_t *ppos)
536{
537 struct event_subsystem *system = filp->private_data;
538 struct trace_seq *s;
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 filter_print_preds(system->preds, s);
551 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
552
553 kfree(s);
554
555 return r;
556}
557
558static ssize_t
559subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
560 loff_t *ppos)
561{
562 struct event_subsystem *system = filp->private_data;
563 char buf[64], *pbuf = buf;
564 struct filter_pred *pred;
565 int err;
566
567 if (cnt >= sizeof(buf))
568 return -EINVAL;
569
570 if (copy_from_user(&buf, ubuf, cnt))
571 return -EFAULT;
572
573 pred = kzalloc(sizeof(*pred), GFP_KERNEL);
574 if (!pred)
575 return -ENOMEM;
576
577 err = filter_parse(&pbuf, pred);
578 if (err < 0) {
579 filter_free_pred(pred);
580 return err;
581 }
582
583 if (pred->clear) {
584 filter_free_subsystem_preds(system);
585 filter_free_pred(pred);
586 return cnt;
587 }
588
589 if (filter_add_subsystem_pred(system, pred)) {
590 filter_free_subsystem_preds(system);
591 filter_free_pred(pred);
592 return -EINVAL;
593 }
594
595 *ppos += cnt;
596
597 return cnt;
598}
599
600static const struct seq_operations show_event_seq_ops = {
601 .start = t_start,
602 .next = t_next,
603 .show = t_show,
604 .stop = t_stop,
605};
606
607static const struct seq_operations show_set_event_seq_ops = {
608 .start = s_start,
609 .next = s_next,
610 .show = t_show,
611 .stop = t_stop,
612};
613
614static const struct file_operations ftrace_avail_fops = {
615 .open = ftrace_event_seq_open,
616 .read = seq_read,
617 .llseek = seq_lseek,
618 .release = seq_release,
619};
620
621static const struct file_operations ftrace_set_event_fops = {
622 .open = ftrace_event_seq_open,
623 .read = seq_read,
624 .write = ftrace_event_write,
625 .llseek = seq_lseek,
626 .release = seq_release,
627};
628
629static const struct file_operations ftrace_enable_fops = {
630 .open = tracing_open_generic,
631 .read = event_enable_read,
632 .write = event_enable_write,
633};
634
635static const struct file_operations ftrace_event_format_fops = {
636 .open = tracing_open_generic,
637 .read = event_format_read,
638};
639
640static const struct file_operations ftrace_event_id_fops = {
641 .open = tracing_open_generic,
642 .read = event_id_read,
643};
644
645static const struct file_operations ftrace_event_filter_fops = {
646 .open = tracing_open_generic,
647 .read = event_filter_read,
648 .write = event_filter_write,
649};
650
651static const struct file_operations ftrace_subsystem_filter_fops = {
652 .open = tracing_open_generic,
653 .read = subsystem_filter_read,
654 .write = subsystem_filter_write,
655};
656
657static struct dentry *event_trace_events_dir(void)
658{
659 static struct dentry *d_tracer;
660 static struct dentry *d_events;
661
662 if (d_events)
663 return d_events;
664
665 d_tracer = tracing_init_dentry();
666 if (!d_tracer)
667 return NULL;
668
669 d_events = debugfs_create_dir("events", d_tracer);
670 if (!d_events)
671 pr_warning("Could not create debugfs "
672 "'events' directory\n");
673
674 return d_events;
675}
676
677static LIST_HEAD(event_subsystems);
678
679static struct dentry *
680event_subsystem_dir(const char *name, struct dentry *d_events)
681{
682 struct event_subsystem *system;
683
684 /* First see if we did not already create this dir */
685 list_for_each_entry(system, &event_subsystems, list) {
686 if (strcmp(system->name, name) == 0)
687 return system->entry;
688 }
689
690 /* need to create new entry */
691 system = kmalloc(sizeof(*system), GFP_KERNEL);
692 if (!system) {
693 pr_warning("No memory to create event subsystem %s\n",
694 name);
695 return d_events;
696 }
697
698 system->entry = debugfs_create_dir(name, d_events);
699 if (!system->entry) {
700 pr_warning("Could not create event subsystem %s\n",
701 name);
702 kfree(system);
703 return d_events;
704 }
705
706 system->name = name;
707 list_add(&system->list, &event_subsystems);
708
709 system->preds = NULL;
710
711 return system->entry;
712}
713
714static int
715event_create_dir(struct ftrace_event_call *call, struct dentry *d_events)
716{
717 struct dentry *entry;
718 int ret;
719
720 /*
721 * If the trace point header did not define TRACE_SYSTEM
722 * then the system would be called "TRACE_SYSTEM".
723 */
724 if (strcmp(call->system, "TRACE_SYSTEM") != 0)
725 d_events = event_subsystem_dir(call->system, d_events);
726
727 if (call->raw_init) {
728 ret = call->raw_init();
729 if (ret < 0) {
730 pr_warning("Could not initialize trace point"
731 " events/%s\n", call->name);
732 return ret;
733 }
734 }
735
736 call->dir = debugfs_create_dir(call->name, d_events);
737 if (!call->dir) {
738 pr_warning("Could not create debugfs "
739 "'%s' directory\n", call->name);
740 return -1;
741 }
742
743 if (call->regfunc) {
744 entry = debugfs_create_file("enable", 0644, call->dir, call,
745 &ftrace_enable_fops);
746 if (!entry)
747 pr_warning("Could not create debugfs "
748 "'%s/enable' entry\n", call->name);
749 }
750
751 if (call->id) {
752 entry = debugfs_create_file("id", 0444, call->dir, call,
753 &ftrace_event_id_fops);
754 if (!entry)
755 pr_warning("Could not create debugfs '%s/id' entry\n",
756 call->name);
757 }
758
759 if (call->define_fields) {
760 ret = call->define_fields();
761 if (ret < 0) {
762 pr_warning("Could not initialize trace point"
763 " events/%s\n", call->name);
764 return ret;
765 }
766 entry = debugfs_create_file("filter", 0644, call->dir, call,
767 &ftrace_event_filter_fops);
768 if (!entry)
769 pr_warning("Could not create debugfs "
770 "'%s/filter' entry\n", call->name);
771 }
772
773 /* A trace may not want to export its format */
774 if (!call->show_format)
775 return 0;
776
777 entry = debugfs_create_file("format", 0444, call->dir, call,
778 &ftrace_event_format_fops);
779 if (!entry)
780 pr_warning("Could not create debugfs "
781 "'%s/format' entry\n", call->name);
782
783 return 0;
784}
785
786static __init int event_trace_init(void)
787{
788 struct ftrace_event_call *call = __start_ftrace_events;
789 struct dentry *d_tracer;
790 struct dentry *entry;
791 struct dentry *d_events;
792
793 d_tracer = tracing_init_dentry();
794 if (!d_tracer)
795 return 0;
796
797 entry = debugfs_create_file("available_events", 0444, d_tracer,
798 (void *)&show_event_seq_ops,
799 &ftrace_avail_fops);
800 if (!entry)
801 pr_warning("Could not create debugfs "
802 "'available_events' entry\n");
803
804 entry = debugfs_create_file("set_event", 0644, d_tracer,
805 (void *)&show_set_event_seq_ops,
806 &ftrace_set_event_fops);
807 if (!entry)
808 pr_warning("Could not create debugfs "
809 "'set_event' entry\n");
810
811 d_events = event_trace_events_dir();
812 if (!d_events)
813 return 0;
814
815 for_each_event(call) {
816 /* The linker may leave blanks */
817 if (!call->name)
818 continue;
819 event_create_dir(call, d_events);
820 }
821
822 return 0;
823}
824fs_initcall(event_trace_init);