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mm-only debug patch...
[mmotm.git] / kernel / trace / trace_events.c
blob7c18d154ea28e0e295fe580099e25849a9626431
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 ssize_t read, ret;
236
237 if (!cnt)
238 return 0;
239
240 ret = tracing_update_buffers();
241 if (ret < 0)
242 return ret;
243
244 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
245 return -ENOMEM;
246
247 read = trace_get_user(&parser, ubuf, cnt, ppos);
248
249 if (read >= 0 && trace_parser_loaded((&parser))) {
250 int set = 1;
251
252 if (*parser.buffer == '!')
253 set = 0;
254
255 parser.buffer[parser.idx] = 0;
256
257 ret = ftrace_set_clr_event(parser.buffer + !set, set);
258 if (ret)
259 goto out_put;
260 }
261
262 ret = read;
263
264 out_put:
265 trace_parser_put(&parser);
266
267 return ret;
268 }
269
270 static void *
271 t_next(struct seq_file *m, void *v, loff_t *pos)
272 {
273 struct ftrace_event_call *call = v;
274
275 (*pos)++;
276
277 list_for_each_entry_continue(call, &ftrace_events, list) {
278 /*
279 * The ftrace subsystem is for showing formats only.
280 * They can not be enabled or disabled via the event files.
281 */
282 if (call->regfunc)
283 return call;
284 }
285
286 return NULL;
287 }
288
289 static void *t_start(struct seq_file *m, loff_t *pos)
290 {
291 struct ftrace_event_call *call;
292 loff_t l;
293
294 mutex_lock(&event_mutex);
295
296 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
297 for (l = 0; l <= *pos; ) {
298 call = t_next(m, call, &l);
299 if (!call)
300 break;
301 }
302 return call;
303 }
304
305 static void *
306 s_next(struct seq_file *m, void *v, loff_t *pos)
307 {
308 struct ftrace_event_call *call = v;
309
310 (*pos)++;
311
312 list_for_each_entry_continue(call, &ftrace_events, list) {
313 if (call->enabled)
314 return call;
315 }
316
317 return NULL;
318 }
319
320 static void *s_start(struct seq_file *m, loff_t *pos)
321 {
322 struct ftrace_event_call *call;
323 loff_t l;
324
325 mutex_lock(&event_mutex);
326
327 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
328 for (l = 0; l <= *pos; ) {
329 call = s_next(m, call, &l);
330 if (!call)
331 break;
332 }
333 return call;
334 }
335
336 static int t_show(struct seq_file *m, void *v)
337 {
338 struct ftrace_event_call *call = v;
339
340 if (strcmp(call->system, TRACE_SYSTEM) != 0)
341 seq_printf(m, "%s:", call->system);
342 seq_printf(m, "%s\n", call->name);
343
344 return 0;
345 }
346
347 static void t_stop(struct seq_file *m, void *p)
348 {
349 mutex_unlock(&event_mutex);
350 }
351
352 static int
353 ftrace_event_seq_open(struct inode *inode, struct file *file)
354 {
355 const struct seq_operations *seq_ops;
356
357 if ((file->f_mode & FMODE_WRITE) &&
358 (file->f_flags & O_TRUNC))
359 ftrace_clear_events();
360
361 seq_ops = inode->i_private;
362 return seq_open(file, seq_ops);
363 }
364
365 static ssize_t
366 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
367 loff_t *ppos)
368 {
369 struct ftrace_event_call *call = filp->private_data;
370 char *buf;
371
372 if (call->enabled)
373 buf = "1\n";
374 else
375 buf = "0\n";
376
377 return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
378 }
379
380 static ssize_t
381 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
382 loff_t *ppos)
383 {
384 struct ftrace_event_call *call = filp->private_data;
385 char buf[64];
386 unsigned long val;
387 int ret;
388
389 if (cnt >= sizeof(buf))
390 return -EINVAL;
391
392 if (copy_from_user(&buf, ubuf, cnt))
393 return -EFAULT;
394
395 buf[cnt] = 0;
396
397 ret = strict_strtoul(buf, 10, &val);
398 if (ret < 0)
399 return ret;
400
401 ret = tracing_update_buffers();
402 if (ret < 0)
403 return ret;
404
405 switch (val) {
406 case 0:
407 case 1:
408 mutex_lock(&event_mutex);
409 ftrace_event_enable_disable(call, val);
410 mutex_unlock(&event_mutex);
411 break;
412
413 default:
414 return -EINVAL;
415 }
416
417 *ppos += cnt;
418
419 return cnt;
420 }
421
422 static ssize_t
423 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
424 loff_t *ppos)
425 {
426 const char set_to_char[4] = { '?', '0', '1', 'X' };
427 const char *system = filp->private_data;
428 struct ftrace_event_call *call;
429 char buf[2];
430 int set = 0;
431 int ret;
432
433 mutex_lock(&event_mutex);
434 list_for_each_entry(call, &ftrace_events, list) {
435 if (!call->name || !call->regfunc)
436 continue;
437
438 if (system && strcmp(call->system, system) != 0)
439 continue;
440
441 /*
442 * We need to find out if all the events are set
443 * or if all events or cleared, or if we have
444 * a mixture.
445 */
446 set |= (1 << !!call->enabled);
447
448 /*
449 * If we have a mixture, no need to look further.
450 */
451 if (set == 3)
452 break;
453 }
454 mutex_unlock(&event_mutex);
455
456 buf[0] = set_to_char[set];
457 buf[1] = '\n';
458
459 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
460
461 return ret;
462 }
463
464 static ssize_t
465 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
466 loff_t *ppos)
467 {
468 const char *system = filp->private_data;
469 unsigned long val;
470 char buf[64];
471 ssize_t ret;
472
473 if (cnt >= sizeof(buf))
474 return -EINVAL;
475
476 if (copy_from_user(&buf, ubuf, cnt))
477 return -EFAULT;
478
479 buf[cnt] = 0;
480
481 ret = strict_strtoul(buf, 10, &val);
482 if (ret < 0)
483 return ret;
484
485 ret = tracing_update_buffers();
486 if (ret < 0)
487 return ret;
488
489 if (val != 0 && val != 1)
490 return -EINVAL;
491
492 ret = __ftrace_set_clr_event(NULL, system, NULL, val);
493 if (ret)
494 goto out;
495
496 ret = cnt;
497
498 out:
499 *ppos += cnt;
500
501 return ret;
502 }
503
504 extern char *__bad_type_size(void);
505
506 #undef FIELD
507 #define FIELD(type, name) \
508 sizeof(type) != sizeof(field.name) ? __bad_type_size() : \
509 #type, "common_" #name, offsetof(typeof(field), name), \
510 sizeof(field.name), is_signed_type(type)
511
512 static int trace_write_header(struct trace_seq *s)
513 {
514 struct trace_entry field;
515
516 /* struct trace_entry */
517 return trace_seq_printf(s,
518 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"
519 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"
520 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"
521 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"
522 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"
523 "\n",
524 FIELD(unsigned short, type),
525 FIELD(unsigned char, flags),
526 FIELD(unsigned char, preempt_count),
527 FIELD(int, pid),
528 FIELD(int, lock_depth));
529 }
530
531 static ssize_t
532 event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
533 loff_t *ppos)
534 {
535 struct ftrace_event_call *call = filp->private_data;
536 struct trace_seq *s;
537 char *buf;
538 int r;
539
540 if (*ppos)
541 return 0;
542
543 s = kmalloc(sizeof(*s), GFP_KERNEL);
544 if (!s)
545 return -ENOMEM;
546
547 trace_seq_init(s);
548
549 /* If any of the first writes fail, so will the show_format. */
550
551 trace_seq_printf(s, "name: %s\n", call->name);
552 trace_seq_printf(s, "ID: %d\n", call->id);
553 trace_seq_printf(s, "format:\n");
554 trace_write_header(s);
555
556 r = call->show_format(call, s);
557 if (!r) {
558 /*
559 * ug! The format output is bigger than a PAGE!!
560 */
561 buf = "FORMAT TOO BIG\n";
562 r = simple_read_from_buffer(ubuf, cnt, ppos,
563 buf, strlen(buf));
564 goto out;
565 }
566
567 r = simple_read_from_buffer(ubuf, cnt, ppos,
568 s->buffer, s->len);
569 out:
570 kfree(s);
571 return r;
572 }
573
574 static ssize_t
575 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
576 {
577 struct ftrace_event_call *call = filp->private_data;
578 struct trace_seq *s;
579 int r;
580
581 if (*ppos)
582 return 0;
583
584 s = kmalloc(sizeof(*s), GFP_KERNEL);
585 if (!s)
586 return -ENOMEM;
587
588 trace_seq_init(s);
589 trace_seq_printf(s, "%d\n", call->id);
590
591 r = simple_read_from_buffer(ubuf, cnt, ppos,
592 s->buffer, s->len);
593 kfree(s);
594 return r;
595 }
596
597 static ssize_t
598 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
599 loff_t *ppos)
600 {
601 struct ftrace_event_call *call = filp->private_data;
602 struct trace_seq *s;
603 int r;
604
605 if (*ppos)
606 return 0;
607
608 s = kmalloc(sizeof(*s), GFP_KERNEL);
609 if (!s)
610 return -ENOMEM;
611
612 trace_seq_init(s);
613
614 print_event_filter(call, s);
615 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
616
617 kfree(s);
618
619 return r;
620 }
621
622 static ssize_t
623 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
624 loff_t *ppos)
625 {
626 struct ftrace_event_call *call = filp->private_data;
627 char *buf;
628 int err;
629
630 if (cnt >= PAGE_SIZE)
631 return -EINVAL;
632
633 buf = (char *)__get_free_page(GFP_TEMPORARY);
634 if (!buf)
635 return -ENOMEM;
636
637 if (copy_from_user(buf, ubuf, cnt)) {
638 free_page((unsigned long) buf);
639 return -EFAULT;
640 }
641 buf[cnt] = '\0';
642
643 err = apply_event_filter(call, buf);
644 free_page((unsigned long) buf);
645 if (err < 0)
646 return err;
647
648 *ppos += cnt;
649
650 return cnt;
651 }
652
653 static ssize_t
654 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
655 loff_t *ppos)
656 {
657 struct event_subsystem *system = filp->private_data;
658 struct trace_seq *s;
659 int r;
660
661 if (*ppos)
662 return 0;
663
664 s = kmalloc(sizeof(*s), GFP_KERNEL);
665 if (!s)
666 return -ENOMEM;
667
668 trace_seq_init(s);
669
670 print_subsystem_event_filter(system, s);
671 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
672
673 kfree(s);
674
675 return r;
676 }
677
678 static ssize_t
679 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
680 loff_t *ppos)
681 {
682 struct event_subsystem *system = filp->private_data;
683 char *buf;
684 int err;
685
686 if (cnt >= PAGE_SIZE)
687 return -EINVAL;
688
689 buf = (char *)__get_free_page(GFP_TEMPORARY);
690 if (!buf)
691 return -ENOMEM;
692
693 if (copy_from_user(buf, ubuf, cnt)) {
694 free_page((unsigned long) buf);
695 return -EFAULT;
696 }
697 buf[cnt] = '\0';
698
699 err = apply_subsystem_event_filter(system, buf);
700 free_page((unsigned long) buf);
701 if (err < 0)
702 return err;
703
704 *ppos += cnt;
705
706 return cnt;
707 }
708
709 static ssize_t
710 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
711 {
712 int (*func)(struct trace_seq *s) = filp->private_data;
713 struct trace_seq *s;
714 int r;
715
716 if (*ppos)
717 return 0;
718
719 s = kmalloc(sizeof(*s), GFP_KERNEL);
720 if (!s)
721 return -ENOMEM;
722
723 trace_seq_init(s);
724
725 func(s);
726 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
727
728 kfree(s);
729
730 return r;
731 }
732
733 static const struct seq_operations show_event_seq_ops = {
734 .start = t_start,
735 .next = t_next,
736 .show = t_show,
737 .stop = t_stop,
738 };
739
740 static const struct seq_operations show_set_event_seq_ops = {
741 .start = s_start,
742 .next = s_next,
743 .show = t_show,
744 .stop = t_stop,
745 };
746
747 static const struct file_operations ftrace_avail_fops = {
748 .open = ftrace_event_seq_open,
749 .read = seq_read,
750 .llseek = seq_lseek,
751 .release = seq_release,
752 };
753
754 static const struct file_operations ftrace_set_event_fops = {
755 .open = ftrace_event_seq_open,
756 .read = seq_read,
757 .write = ftrace_event_write,
758 .llseek = seq_lseek,
759 .release = seq_release,
760 };
761
762 static const struct file_operations ftrace_enable_fops = {
763 .open = tracing_open_generic,
764 .read = event_enable_read,
765 .write = event_enable_write,
766 };
767
768 static const struct file_operations ftrace_event_format_fops = {
769 .open = tracing_open_generic,
770 .read = event_format_read,
771 };
772
773 static const struct file_operations ftrace_event_id_fops = {
774 .open = tracing_open_generic,
775 .read = event_id_read,
776 };
777
778 static const struct file_operations ftrace_event_filter_fops = {
779 .open = tracing_open_generic,
780 .read = event_filter_read,
781 .write = event_filter_write,
782 };
783
784 static const struct file_operations ftrace_subsystem_filter_fops = {
785 .open = tracing_open_generic,
786 .read = subsystem_filter_read,
787 .write = subsystem_filter_write,
788 };
789
790 static const struct file_operations ftrace_system_enable_fops = {
791 .open = tracing_open_generic,
792 .read = system_enable_read,
793 .write = system_enable_write,
794 };
795
796 static const struct file_operations ftrace_show_header_fops = {
797 .open = tracing_open_generic,
798 .read = show_header,
799 };
800
801 static struct dentry *event_trace_events_dir(void)
802 {
803 static struct dentry *d_tracer;
804 static struct dentry *d_events;
805
806 if (d_events)
807 return d_events;
808
809 d_tracer = tracing_init_dentry();
810 if (!d_tracer)
811 return NULL;
812
813 d_events = debugfs_create_dir("events", d_tracer);
814 if (!d_events)
815 pr_warning("Could not create debugfs "
816 "'events' directory\n");
817
818 return d_events;
819 }
820
821 static LIST_HEAD(event_subsystems);
822
823 static struct dentry *
824 event_subsystem_dir(const char *name, struct dentry *d_events)
825 {
826 struct event_subsystem *system;
827 struct dentry *entry;
828
829 /* First see if we did not already create this dir */
830 list_for_each_entry(system, &event_subsystems, list) {
831 if (strcmp(system->name, name) == 0) {
832 system->nr_events++;
833 return system->entry;
834 }
835 }
836
837 /* need to create new entry */
838 system = kmalloc(sizeof(*system), GFP_KERNEL);
839 if (!system) {
840 pr_warning("No memory to create event subsystem %s\n",
841 name);
842 return d_events;
843 }
844
845 system->entry = debugfs_create_dir(name, d_events);
846 if (!system->entry) {
847 pr_warning("Could not create event subsystem %s\n",
848 name);
849 kfree(system);
850 return d_events;
851 }
852
853 system->nr_events = 1;
854 system->name = kstrdup(name, GFP_KERNEL);
855 if (!system->name) {
856 debugfs_remove(system->entry);
857 kfree(system);
858 return d_events;
859 }
860
861 list_add(&system->list, &event_subsystems);
862
863 system->filter = NULL;
864
865 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
866 if (!system->filter) {
867 pr_warning("Could not allocate filter for subsystem "
868 "'%s'\n", name);
869 return system->entry;
870 }
871
872 entry = debugfs_create_file("filter", 0644, system->entry, system,
873 &ftrace_subsystem_filter_fops);
874 if (!entry) {
875 kfree(system->filter);
876 system->filter = NULL;
877 pr_warning("Could not create debugfs "
878 "'%s/filter' entry\n", name);
879 }
880
881 trace_create_file("enable", 0644, system->entry,
882 (void *)system->name,
883 &ftrace_system_enable_fops);
884
885 return system->entry;
886 }
887
888 static int
889 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
890 const struct file_operations *id,
891 const struct file_operations *enable,
892 const struct file_operations *filter,
893 const struct file_operations *format)
894 {
895 int ret;
896
897 /*
898 * If the trace point header did not define TRACE_SYSTEM
899 * then the system would be called "TRACE_SYSTEM".
900 */
901 if (strcmp(call->system, TRACE_SYSTEM) != 0)
902 d_events = event_subsystem_dir(call->system, d_events);
903
904 call->dir = debugfs_create_dir(call->name, d_events);
905 if (!call->dir) {
906 pr_warning("Could not create debugfs "
907 "'%s' directory\n", call->name);
908 return -1;
909 }
910
911 if (call->regfunc)
912 trace_create_file("enable", 0644, call->dir, call,
913 enable);
914
915 if (call->id && call->profile_enable)
916 trace_create_file("id", 0444, call->dir, call,
917 id);
918
919 if (call->define_fields) {
920 ret = call->define_fields(call);
921 if (ret < 0) {
922 pr_warning("Could not initialize trace point"
923 " events/%s\n", call->name);
924 return ret;
925 }
926 trace_create_file("filter", 0644, call->dir, call,
927 filter);
928 }
929
930 /* A trace may not want to export its format */
931 if (!call->show_format)
932 return 0;
933
934 trace_create_file("format", 0444, call->dir, call,
935 format);
936
937 return 0;
938 }
939
940 #define for_each_event(event, start, end) \
941 for (event = start; \
942 (unsigned long)event < (unsigned long)end; \
943 event++)
944
945 #ifdef CONFIG_MODULES
946
947 static LIST_HEAD(ftrace_module_file_list);
948
949 /*
950 * Modules must own their file_operations to keep up with
951 * reference counting.
952 */
953 struct ftrace_module_file_ops {
954 struct list_head list;
955 struct module *mod;
956 struct file_operations id;
957 struct file_operations enable;
958 struct file_operations format;
959 struct file_operations filter;
960 };
961
962 static void remove_subsystem_dir(const char *name)
963 {
964 struct event_subsystem *system;
965
966 if (strcmp(name, TRACE_SYSTEM) == 0)
967 return;
968
969 list_for_each_entry(system, &event_subsystems, list) {
970 if (strcmp(system->name, name) == 0) {
971 if (!--system->nr_events) {
972 struct event_filter *filter = system->filter;
973
974 debugfs_remove_recursive(system->entry);
975 list_del(&system->list);
976 if (filter) {
977 kfree(filter->filter_string);
978 kfree(filter);
979 }
980 kfree(system->name);
981 kfree(system);
982 }
983 break;
984 }
985 }
986 }
987
988 static struct ftrace_module_file_ops *
989 trace_create_file_ops(struct module *mod)
990 {
991 struct ftrace_module_file_ops *file_ops;
992
993 /*
994 * This is a bit of a PITA. To allow for correct reference
995 * counting, modules must "own" their file_operations.
996 * To do this, we allocate the file operations that will be
997 * used in the event directory.
998 */
999
1000 file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1001 if (!file_ops)
1002 return NULL;
1003
1004 file_ops->mod = mod;
1005
1006 file_ops->id = ftrace_event_id_fops;
1007 file_ops->id.owner = mod;
1008
1009 file_ops->enable = ftrace_enable_fops;
1010 file_ops->enable.owner = mod;
1011
1012 file_ops->filter = ftrace_event_filter_fops;
1013 file_ops->filter.owner = mod;
1014
1015 file_ops->format = ftrace_event_format_fops;
1016 file_ops->format.owner = mod;
1017
1018 list_add(&file_ops->list, &ftrace_module_file_list);
1019
1020 return file_ops;
1021 }
1022
1023 static void trace_module_add_events(struct module *mod)
1024 {
1025 struct ftrace_module_file_ops *file_ops = NULL;
1026 struct ftrace_event_call *call, *start, *end;
1027 struct dentry *d_events;
1028 int ret;
1029
1030 start = mod->trace_events;
1031 end = mod->trace_events + mod->num_trace_events;
1032
1033 if (start == end)
1034 return;
1035
1036 d_events = event_trace_events_dir();
1037 if (!d_events)
1038 return;
1039
1040 for_each_event(call, start, end) {
1041 /* The linker may leave blanks */
1042 if (!call->name)
1043 continue;
1044 if (call->raw_init) {
1045 ret = call->raw_init();
1046 if (ret < 0) {
1047 if (ret != -ENOSYS)
1048 pr_warning("Could not initialize trace "
1049 "point events/%s\n", call->name);
1050 continue;
1051 }
1052 }
1053 /*
1054 * This module has events, create file ops for this module
1055 * if not already done.
1056 */
1057 if (!file_ops) {
1058 file_ops = trace_create_file_ops(mod);
1059 if (!file_ops)
1060 return;
1061 }
1062 call->mod = mod;
1063 list_add(&call->list, &ftrace_events);
1064 event_create_dir(call, d_events,
1065 &file_ops->id, &file_ops->enable,
1066 &file_ops->filter, &file_ops->format);
1067 }
1068 }
1069
1070 static void trace_module_remove_events(struct module *mod)
1071 {
1072 struct ftrace_module_file_ops *file_ops;
1073 struct ftrace_event_call *call, *p;
1074 bool found = false;
1075
1076 down_write(&trace_event_mutex);
1077 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1078 if (call->mod == mod) {
1079 found = true;
1080 ftrace_event_enable_disable(call, 0);
1081 if (call->event)
1082 __unregister_ftrace_event(call->event);
1083 debugfs_remove_recursive(call->dir);
1084 list_del(&call->list);
1085 trace_destroy_fields(call);
1086 destroy_preds(call);
1087 remove_subsystem_dir(call->system);
1088 }
1089 }
1090
1091 /* Now free the file_operations */
1092 list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1093 if (file_ops->mod == mod)
1094 break;
1095 }
1096 if (&file_ops->list != &ftrace_module_file_list) {
1097 list_del(&file_ops->list);
1098 kfree(file_ops);
1099 }
1100
1101 /*
1102 * It is safest to reset the ring buffer if the module being unloaded
1103 * registered any events.
1104 */
1105 if (found)
1106 tracing_reset_current_online_cpus();
1107 up_write(&trace_event_mutex);
1108 }
1109
1110 static int trace_module_notify(struct notifier_block *self,
1111 unsigned long val, void *data)
1112 {
1113 struct module *mod = data;
1114
1115 mutex_lock(&event_mutex);
1116 switch (val) {
1117 case MODULE_STATE_COMING:
1118 trace_module_add_events(mod);
1119 break;
1120 case MODULE_STATE_GOING:
1121 trace_module_remove_events(mod);
1122 break;
1123 }
1124 mutex_unlock(&event_mutex);
1125
1126 return 0;
1127 }
1128 #else
1129 static int trace_module_notify(struct notifier_block *self,
1130 unsigned long val, void *data)
1131 {
1132 return 0;
1133 }
1134 #endif /* CONFIG_MODULES */
1135
1136 static struct notifier_block trace_module_nb = {
1137 .notifier_call = trace_module_notify,
1138 .priority = 0,
1139 };
1140
1141 extern struct ftrace_event_call __start_ftrace_events[];
1142 extern struct ftrace_event_call __stop_ftrace_events[];
1143
1144 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1145
1146 static __init int setup_trace_event(char *str)
1147 {
1148 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1149 ring_buffer_expanded = 1;
1150 tracing_selftest_disabled = 1;
1151
1152 return 1;
1153 }
1154 __setup("trace_event=", setup_trace_event);
1155
1156 static __init int event_trace_init(void)
1157 {
1158 struct ftrace_event_call *call;
1159 struct dentry *d_tracer;
1160 struct dentry *entry;
1161 struct dentry *d_events;
1162 int ret;
1163 char *buf = bootup_event_buf;
1164 char *token;
1165
1166 d_tracer = tracing_init_dentry();
1167 if (!d_tracer)
1168 return 0;
1169
1170 entry = debugfs_create_file("available_events", 0444, d_tracer,
1171 (void *)&show_event_seq_ops,
1172 &ftrace_avail_fops);
1173 if (!entry)
1174 pr_warning("Could not create debugfs "
1175 "'available_events' entry\n");
1176
1177 entry = debugfs_create_file("set_event", 0644, d_tracer,
1178 (void *)&show_set_event_seq_ops,
1179 &ftrace_set_event_fops);
1180 if (!entry)
1181 pr_warning("Could not create debugfs "
1182 "'set_event' entry\n");
1183
1184 d_events = event_trace_events_dir();
1185 if (!d_events)
1186 return 0;
1187
1188 /* ring buffer internal formats */
1189 trace_create_file("header_page", 0444, d_events,
1190 ring_buffer_print_page_header,
1191 &ftrace_show_header_fops);
1192
1193 trace_create_file("header_event", 0444, d_events,
1194 ring_buffer_print_entry_header,
1195 &ftrace_show_header_fops);
1196
1197 trace_create_file("enable", 0644, d_events,
1198 NULL, &ftrace_system_enable_fops);
1199
1200 for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
1201 /* The linker may leave blanks */
1202 if (!call->name)
1203 continue;
1204 if (call->raw_init) {
1205 ret = call->raw_init();
1206 if (ret < 0) {
1207 if (ret != -ENOSYS)
1208 pr_warning("Could not initialize trace "
1209 "point events/%s\n", call->name);
1210 continue;
1211 }
1212 }
1213 list_add(&call->list, &ftrace_events);
1214 event_create_dir(call, d_events, &ftrace_event_id_fops,
1215 &ftrace_enable_fops, &ftrace_event_filter_fops,
1216 &ftrace_event_format_fops);
1217 }
1218
1219 while (true) {
1220 token = strsep(&buf, ",");
1221
1222 if (!token)
1223 break;
1224 if (!*token)
1225 continue;
1226
1227 ret = ftrace_set_clr_event(token, 1);
1228 if (ret)
1229 pr_warning("Failed to enable trace event: %s\n", token);
1230 }
1231
1232 ret = register_module_notifier(&trace_module_nb);
1233 if (ret)
1234 pr_warning("Failed to register trace events module notifier\n");
1235
1236 return 0;
1237 }
1238 fs_initcall(event_trace_init);
1239
1240 #ifdef CONFIG_FTRACE_STARTUP_TEST
1241
1242 static DEFINE_SPINLOCK(test_spinlock);
1243 static DEFINE_SPINLOCK(test_spinlock_irq);
1244 static DEFINE_MUTEX(test_mutex);
1245
1246 static __init void test_work(struct work_struct *dummy)
1247 {
1248 spin_lock(&test_spinlock);
1249 spin_lock_irq(&test_spinlock_irq);
1250 udelay(1);
1251 spin_unlock_irq(&test_spinlock_irq);
1252 spin_unlock(&test_spinlock);
1253
1254 mutex_lock(&test_mutex);
1255 msleep(1);
1256 mutex_unlock(&test_mutex);
1257 }
1258
1259 static __init int event_test_thread(void *unused)
1260 {
1261 void *test_malloc;
1262
1263 test_malloc = kmalloc(1234, GFP_KERNEL);
1264 if (!test_malloc)
1265 pr_info("failed to kmalloc\n");
1266
1267 schedule_on_each_cpu(test_work);
1268
1269 kfree(test_malloc);
1270
1271 set_current_state(TASK_INTERRUPTIBLE);
1272 while (!kthread_should_stop())
1273 schedule();
1274
1275 return 0;
1276 }
1277
1278 /*
1279 * Do various things that may trigger events.
1280 */
1281 static __init void event_test_stuff(void)
1282 {
1283 struct task_struct *test_thread;
1284
1285 test_thread = kthread_run(event_test_thread, NULL, "test-events");
1286 msleep(1);
1287 kthread_stop(test_thread);
1288 }
1289
1290 /*
1291 * For every trace event defined, we will test each trace point separately,
1292 * and then by groups, and finally all trace points.
1293 */
1294 static __init void event_trace_self_tests(void)
1295 {
1296 struct ftrace_event_call *call;
1297 struct event_subsystem *system;
1298 int ret;
1299
1300 pr_info("Running tests on trace events:\n");
1301
1302 list_for_each_entry(call, &ftrace_events, list) {
1303
1304 /* Only test those that have a regfunc */
1305 if (!call->regfunc)
1306 continue;
1307
1308 /*
1309 * Testing syscall events here is pretty useless, but
1310 * we still do it if configured. But this is time consuming.
1311 * What we really need is a user thread to perform the
1312 * syscalls as we test.
1313 */
1314 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1315 if (call->system &&
1316 strcmp(call->system, "syscalls") == 0)
1317 continue;
1318 #endif
1319
1320 pr_info("Testing event %s: ", call->name);
1321
1322 /*
1323 * If an event is already enabled, someone is using
1324 * it and the self test should not be on.
1325 */
1326 if (call->enabled) {
1327 pr_warning("Enabled event during self test!\n");
1328 WARN_ON_ONCE(1);
1329 continue;
1330 }
1331
1332 ftrace_event_enable_disable(call, 1);
1333 event_test_stuff();
1334 ftrace_event_enable_disable(call, 0);
1335
1336 pr_cont("OK\n");
1337 }
1338
1339 /* Now test at the sub system level */
1340
1341 pr_info("Running tests on trace event systems:\n");
1342
1343 list_for_each_entry(system, &event_subsystems, list) {
1344
1345 /* the ftrace system is special, skip it */
1346 if (strcmp(system->name, "ftrace") == 0)
1347 continue;
1348
1349 pr_info("Testing event system %s: ", system->name);
1350
1351 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1352 if (WARN_ON_ONCE(ret)) {
1353 pr_warning("error enabling system %s\n",
1354 system->name);
1355 continue;
1356 }
1357
1358 event_test_stuff();
1359
1360 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1361 if (WARN_ON_ONCE(ret))
1362 pr_warning("error disabling system %s\n",
1363 system->name);
1364
1365 pr_cont("OK\n");
1366 }
1367
1368 /* Test with all events enabled */
1369
1370 pr_info("Running tests on all trace events:\n");
1371 pr_info("Testing all events: ");
1372
1373 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1374 if (WARN_ON_ONCE(ret)) {
1375 pr_warning("error enabling all events\n");
1376 return;
1377 }
1378
1379 event_test_stuff();
1380
1381 /* reset sysname */
1382 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1383 if (WARN_ON_ONCE(ret)) {
1384 pr_warning("error disabling all events\n");
1385 return;
1386 }
1387
1388 pr_cont("OK\n");
1389 }
1390
1391 #ifdef CONFIG_FUNCTION_TRACER
1392
1393 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1394
1395 static void
1396 function_test_events_call(unsigned long ip, unsigned long parent_ip)
1397 {
1398 struct ring_buffer_event *event;
1399 struct ring_buffer *buffer;
1400 struct ftrace_entry *entry;
1401 unsigned long flags;
1402 long disabled;
1403 int resched;
1404 int cpu;
1405 int pc;
1406
1407 pc = preempt_count();
1408 resched = ftrace_preempt_disable();
1409 cpu = raw_smp_processor_id();
1410 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1411
1412 if (disabled != 1)
1413 goto out;
1414
1415 local_save_flags(flags);
1416
1417 event = trace_current_buffer_lock_reserve(&buffer,
1418 TRACE_FN, sizeof(*entry),
1419 flags, pc);
1420 if (!event)
1421 goto out;
1422 entry = ring_buffer_event_data(event);
1423 entry->ip = ip;
1424 entry->parent_ip = parent_ip;
1425
1426 trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
1427
1428 out:
1429 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1430 ftrace_preempt_enable(resched);
1431 }
1432
1433 static struct ftrace_ops trace_ops __initdata =
1434 {
1435 .func = function_test_events_call,
1436 };
1437
1438 static __init void event_trace_self_test_with_function(void)
1439 {
1440 register_ftrace_function(&trace_ops);
1441 pr_info("Running tests again, along with the function tracer\n");
1442 event_trace_self_tests();
1443 unregister_ftrace_function(&trace_ops);
1444 }
1445 #else
1446 static __init void event_trace_self_test_with_function(void)
1447 {
1448 }
1449 #endif
1450
1451 static __init int event_trace_self_tests_init(void)
1452 {
1453 if (!tracing_selftest_disabled) {
1454 event_trace_self_tests();
1455 event_trace_self_test_with_function();
1456 }
1457
1458 return 0;
1459 }
1460
1461 late_initcall(event_trace_self_tests_init);
1462
1463 #endif
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