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Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
[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/slab.h>
19 #include <linux/delay.h>
20
21 #include <asm/setup.h>
22
23 #include "trace_output.h"
24
25 #undef TRACE_SYSTEM
26 #define TRACE_SYSTEM "TRACE_SYSTEM"
27
28 DEFINE_MUTEX(event_mutex);
29
30 DEFINE_MUTEX(event_storage_mutex);
31 EXPORT_SYMBOL_GPL(event_storage_mutex);
32
33 char event_storage[EVENT_STORAGE_SIZE];
34 EXPORT_SYMBOL_GPL(event_storage);
35
36 LIST_HEAD(ftrace_events);
37 static LIST_HEAD(ftrace_common_fields);
38
39 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
40
41 static struct kmem_cache *field_cachep;
42 static struct kmem_cache *file_cachep;
43
44 #define SYSTEM_FL_FREE_NAME (1 << 31)
45
46 static inline int system_refcount(struct event_subsystem *system)
47 {
48 return system->ref_count & ~SYSTEM_FL_FREE_NAME;
49 }
50
51 static int system_refcount_inc(struct event_subsystem *system)
52 {
53 return (system->ref_count++) & ~SYSTEM_FL_FREE_NAME;
54 }
55
56 static int system_refcount_dec(struct event_subsystem *system)
57 {
58 return (--system->ref_count) & ~SYSTEM_FL_FREE_NAME;
59 }
60
61 /* Double loops, do not use break, only goto's work */
62 #define do_for_each_event_file(tr, file) \
63 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
64 list_for_each_entry(file, &tr->events, list)
65
66 #define do_for_each_event_file_safe(tr, file) \
67 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
68 struct ftrace_event_file *___n; \
69 list_for_each_entry_safe(file, ___n, &tr->events, list)
70
71 #define while_for_each_event_file() \
72 }
73
74 static struct list_head *
75 trace_get_fields(struct ftrace_event_call *event_call)
76 {
77 if (!event_call->class->get_fields)
78 return &event_call->class->fields;
79 return event_call->class->get_fields(event_call);
80 }
81
82 static struct ftrace_event_field *
83 __find_event_field(struct list_head *head, char *name)
84 {
85 struct ftrace_event_field *field;
86
87 list_for_each_entry(field, head, link) {
88 if (!strcmp(field->name, name))
89 return field;
90 }
91
92 return NULL;
93 }
94
95 struct ftrace_event_field *
96 trace_find_event_field(struct ftrace_event_call *call, char *name)
97 {
98 struct ftrace_event_field *field;
99 struct list_head *head;
100
101 field = __find_event_field(&ftrace_common_fields, name);
102 if (field)
103 return field;
104
105 head = trace_get_fields(call);
106 return __find_event_field(head, name);
107 }
108
109 static int __trace_define_field(struct list_head *head, const char *type,
110 const char *name, int offset, int size,
111 int is_signed, int filter_type)
112 {
113 struct ftrace_event_field *field;
114
115 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
116 if (!field)
117 return -ENOMEM;
118
119 field->name = name;
120 field->type = type;
121
122 if (filter_type == FILTER_OTHER)
123 field->filter_type = filter_assign_type(type);
124 else
125 field->filter_type = filter_type;
126
127 field->offset = offset;
128 field->size = size;
129 field->is_signed = is_signed;
130
131 list_add(&field->link, head);
132
133 return 0;
134 }
135
136 int trace_define_field(struct ftrace_event_call *call, const char *type,
137 const char *name, int offset, int size, int is_signed,
138 int filter_type)
139 {
140 struct list_head *head;
141
142 if (WARN_ON(!call->class))
143 return 0;
144
145 head = trace_get_fields(call);
146 return __trace_define_field(head, type, name, offset, size,
147 is_signed, filter_type);
148 }
149 EXPORT_SYMBOL_GPL(trace_define_field);
150
151 #define __common_field(type, item) \
152 ret = __trace_define_field(&ftrace_common_fields, #type, \
153 "common_" #item, \
154 offsetof(typeof(ent), item), \
155 sizeof(ent.item), \
156 is_signed_type(type), FILTER_OTHER); \
157 if (ret) \
158 return ret;
159
160 static int trace_define_common_fields(void)
161 {
162 int ret;
163 struct trace_entry ent;
164
165 __common_field(unsigned short, type);
166 __common_field(unsigned char, flags);
167 __common_field(unsigned char, preempt_count);
168 __common_field(int, pid);
169
170 return ret;
171 }
172
173 static void trace_destroy_fields(struct ftrace_event_call *call)
174 {
175 struct ftrace_event_field *field, *next;
176 struct list_head *head;
177
178 head = trace_get_fields(call);
179 list_for_each_entry_safe(field, next, head, link) {
180 list_del(&field->link);
181 kmem_cache_free(field_cachep, field);
182 }
183 }
184
185 int trace_event_raw_init(struct ftrace_event_call *call)
186 {
187 int id;
188
189 id = register_ftrace_event(&call->event);
190 if (!id)
191 return -ENODEV;
192
193 return 0;
194 }
195 EXPORT_SYMBOL_GPL(trace_event_raw_init);
196
197 int ftrace_event_reg(struct ftrace_event_call *call,
198 enum trace_reg type, void *data)
199 {
200 struct ftrace_event_file *file = data;
201
202 switch (type) {
203 case TRACE_REG_REGISTER:
204 return tracepoint_probe_register(call->name,
205 call->class->probe,
206 file);
207 case TRACE_REG_UNREGISTER:
208 tracepoint_probe_unregister(call->name,
209 call->class->probe,
210 file);
211 return 0;
212
213 #ifdef CONFIG_PERF_EVENTS
214 case TRACE_REG_PERF_REGISTER:
215 return tracepoint_probe_register(call->name,
216 call->class->perf_probe,
217 call);
218 case TRACE_REG_PERF_UNREGISTER:
219 tracepoint_probe_unregister(call->name,
220 call->class->perf_probe,
221 call);
222 return 0;
223 case TRACE_REG_PERF_OPEN:
224 case TRACE_REG_PERF_CLOSE:
225 case TRACE_REG_PERF_ADD:
226 case TRACE_REG_PERF_DEL:
227 return 0;
228 #endif
229 }
230 return 0;
231 }
232 EXPORT_SYMBOL_GPL(ftrace_event_reg);
233
234 void trace_event_enable_cmd_record(bool enable)
235 {
236 struct ftrace_event_file *file;
237 struct trace_array *tr;
238
239 mutex_lock(&event_mutex);
240 do_for_each_event_file(tr, file) {
241
242 if (!(file->flags & FTRACE_EVENT_FL_ENABLED))
243 continue;
244
245 if (enable) {
246 tracing_start_cmdline_record();
247 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
248 } else {
249 tracing_stop_cmdline_record();
250 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
251 }
252 } while_for_each_event_file();
253 mutex_unlock(&event_mutex);
254 }
255
256 static int __ftrace_event_enable_disable(struct ftrace_event_file *file,
257 int enable, int soft_disable)
258 {
259 struct ftrace_event_call *call = file->event_call;
260 int ret = 0;
261 int disable;
262
263 switch (enable) {
264 case 0:
265 /*
266 * When soft_disable is set and enable is cleared, the sm_ref
267 * reference counter is decremented. If it reaches 0, we want
268 * to clear the SOFT_DISABLED flag but leave the event in the
269 * state that it was. That is, if the event was enabled and
270 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
271 * is set we do not want the event to be enabled before we
272 * clear the bit.
273 *
274 * When soft_disable is not set but the SOFT_MODE flag is,
275 * we do nothing. Do not disable the tracepoint, otherwise
276 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
277 */
278 if (soft_disable) {
279 if (atomic_dec_return(&file->sm_ref) > 0)
280 break;
281 disable = file->flags & FTRACE_EVENT_FL_SOFT_DISABLED;
282 clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
283 } else
284 disable = !(file->flags & FTRACE_EVENT_FL_SOFT_MODE);
285
286 if (disable && (file->flags & FTRACE_EVENT_FL_ENABLED)) {
287 clear_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
288 if (file->flags & FTRACE_EVENT_FL_RECORDED_CMD) {
289 tracing_stop_cmdline_record();
290 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
291 }
292 call->class->reg(call, TRACE_REG_UNREGISTER, file);
293 }
294 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
295 if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
296 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
297 else
298 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
299 break;
300 case 1:
301 /*
302 * When soft_disable is set and enable is set, we want to
303 * register the tracepoint for the event, but leave the event
304 * as is. That means, if the event was already enabled, we do
305 * nothing (but set SOFT_MODE). If the event is disabled, we
306 * set SOFT_DISABLED before enabling the event tracepoint, so
307 * it still seems to be disabled.
308 */
309 if (!soft_disable)
310 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
311 else {
312 if (atomic_inc_return(&file->sm_ref) > 1)
313 break;
314 set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
315 }
316
317 if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) {
318
319 /* Keep the event disabled, when going to SOFT_MODE. */
320 if (soft_disable)
321 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
322
323 if (trace_flags & TRACE_ITER_RECORD_CMD) {
324 tracing_start_cmdline_record();
325 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
326 }
327 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
328 if (ret) {
329 tracing_stop_cmdline_record();
330 pr_info("event trace: Could not enable event "
331 "%s\n", call->name);
332 break;
333 }
334 set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
335
336 /* WAS_ENABLED gets set but never cleared. */
337 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
338 }
339 break;
340 }
341
342 return ret;
343 }
344
345 static int ftrace_event_enable_disable(struct ftrace_event_file *file,
346 int enable)
347 {
348 return __ftrace_event_enable_disable(file, enable, 0);
349 }
350
351 static void ftrace_clear_events(struct trace_array *tr)
352 {
353 struct ftrace_event_file *file;
354
355 mutex_lock(&event_mutex);
356 list_for_each_entry(file, &tr->events, list) {
357 ftrace_event_enable_disable(file, 0);
358 }
359 mutex_unlock(&event_mutex);
360 }
361
362 static void __put_system(struct event_subsystem *system)
363 {
364 struct event_filter *filter = system->filter;
365
366 WARN_ON_ONCE(system_refcount(system) == 0);
367 if (system_refcount_dec(system))
368 return;
369
370 list_del(&system->list);
371
372 if (filter) {
373 kfree(filter->filter_string);
374 kfree(filter);
375 }
376 if (system->ref_count & SYSTEM_FL_FREE_NAME)
377 kfree(system->name);
378 kfree(system);
379 }
380
381 static void __get_system(struct event_subsystem *system)
382 {
383 WARN_ON_ONCE(system_refcount(system) == 0);
384 system_refcount_inc(system);
385 }
386
387 static void __get_system_dir(struct ftrace_subsystem_dir *dir)
388 {
389 WARN_ON_ONCE(dir->ref_count == 0);
390 dir->ref_count++;
391 __get_system(dir->subsystem);
392 }
393
394 static void __put_system_dir(struct ftrace_subsystem_dir *dir)
395 {
396 WARN_ON_ONCE(dir->ref_count == 0);
397 /* If the subsystem is about to be freed, the dir must be too */
398 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
399
400 __put_system(dir->subsystem);
401 if (!--dir->ref_count)
402 kfree(dir);
403 }
404
405 static void put_system(struct ftrace_subsystem_dir *dir)
406 {
407 mutex_lock(&event_mutex);
408 __put_system_dir(dir);
409 mutex_unlock(&event_mutex);
410 }
411
412 static void remove_subsystem(struct ftrace_subsystem_dir *dir)
413 {
414 if (!dir)
415 return;
416
417 if (!--dir->nr_events) {
418 debugfs_remove_recursive(dir->entry);
419 list_del(&dir->list);
420 __put_system_dir(dir);
421 }
422 }
423
424 static void *event_file_data(struct file *filp)
425 {
426 return ACCESS_ONCE(file_inode(filp)->i_private);
427 }
428
429 static void remove_event_file_dir(struct ftrace_event_file *file)
430 {
431 struct dentry *dir = file->dir;
432 struct dentry *child;
433
434 if (dir) {
435 spin_lock(&dir->d_lock); /* probably unneeded */
436 list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
437 if (child->d_inode) /* probably unneeded */
438 child->d_inode->i_private = NULL;
439 }
440 spin_unlock(&dir->d_lock);
441
442 debugfs_remove_recursive(dir);
443 }
444
445 list_del(&file->list);
446 remove_subsystem(file->system);
447 kmem_cache_free(file_cachep, file);
448 }
449
450 /*
451 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
452 */
453 static int
454 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
455 const char *sub, const char *event, int set)
456 {
457 struct ftrace_event_file *file;
458 struct ftrace_event_call *call;
459 int ret = -EINVAL;
460
461 list_for_each_entry(file, &tr->events, list) {
462
463 call = file->event_call;
464
465 if (!call->name || !call->class || !call->class->reg)
466 continue;
467
468 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
469 continue;
470
471 if (match &&
472 strcmp(match, call->name) != 0 &&
473 strcmp(match, call->class->system) != 0)
474 continue;
475
476 if (sub && strcmp(sub, call->class->system) != 0)
477 continue;
478
479 if (event && strcmp(event, call->name) != 0)
480 continue;
481
482 ftrace_event_enable_disable(file, set);
483
484 ret = 0;
485 }
486
487 return ret;
488 }
489
490 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
491 const char *sub, const char *event, int set)
492 {
493 int ret;
494
495 mutex_lock(&event_mutex);
496 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
497 mutex_unlock(&event_mutex);
498
499 return ret;
500 }
501
502 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
503 {
504 char *event = NULL, *sub = NULL, *match;
505
506 /*
507 * The buf format can be <subsystem>:<event-name>
508 * *:<event-name> means any event by that name.
509 * :<event-name> is the same.
510 *
511 * <subsystem>:* means all events in that subsystem
512 * <subsystem>: means the same.
513 *
514 * <name> (no ':') means all events in a subsystem with
515 * the name <name> or any event that matches <name>
516 */
517
518 match = strsep(&buf, ":");
519 if (buf) {
520 sub = match;
521 event = buf;
522 match = NULL;
523
524 if (!strlen(sub) || strcmp(sub, "*") == 0)
525 sub = NULL;
526 if (!strlen(event) || strcmp(event, "*") == 0)
527 event = NULL;
528 }
529
530 return __ftrace_set_clr_event(tr, match, sub, event, set);
531 }
532
533 /**
534 * trace_set_clr_event - enable or disable an event
535 * @system: system name to match (NULL for any system)
536 * @event: event name to match (NULL for all events, within system)
537 * @set: 1 to enable, 0 to disable
538 *
539 * This is a way for other parts of the kernel to enable or disable
540 * event recording.
541 *
542 * Returns 0 on success, -EINVAL if the parameters do not match any
543 * registered events.
544 */
545 int trace_set_clr_event(const char *system, const char *event, int set)
546 {
547 struct trace_array *tr = top_trace_array();
548
549 return __ftrace_set_clr_event(tr, NULL, system, event, set);
550 }
551 EXPORT_SYMBOL_GPL(trace_set_clr_event);
552
553 /* 128 should be much more than enough */
554 #define EVENT_BUF_SIZE 127
555
556 static ssize_t
557 ftrace_event_write(struct file *file, const char __user *ubuf,
558 size_t cnt, loff_t *ppos)
559 {
560 struct trace_parser parser;
561 struct seq_file *m = file->private_data;
562 struct trace_array *tr = m->private;
563 ssize_t read, ret;
564
565 if (!cnt)
566 return 0;
567
568 ret = tracing_update_buffers();
569 if (ret < 0)
570 return ret;
571
572 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
573 return -ENOMEM;
574
575 read = trace_get_user(&parser, ubuf, cnt, ppos);
576
577 if (read >= 0 && trace_parser_loaded((&parser))) {
578 int set = 1;
579
580 if (*parser.buffer == '!')
581 set = 0;
582
583 parser.buffer[parser.idx] = 0;
584
585 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
586 if (ret)
587 goto out_put;
588 }
589
590 ret = read;
591
592 out_put:
593 trace_parser_put(&parser);
594
595 return ret;
596 }
597
598 static void *
599 t_next(struct seq_file *m, void *v, loff_t *pos)
600 {
601 struct ftrace_event_file *file = v;
602 struct ftrace_event_call *call;
603 struct trace_array *tr = m->private;
604
605 (*pos)++;
606
607 list_for_each_entry_continue(file, &tr->events, list) {
608 call = file->event_call;
609 /*
610 * The ftrace subsystem is for showing formats only.
611 * They can not be enabled or disabled via the event files.
612 */
613 if (call->class && call->class->reg)
614 return file;
615 }
616
617 return NULL;
618 }
619
620 static void *t_start(struct seq_file *m, loff_t *pos)
621 {
622 struct ftrace_event_file *file;
623 struct trace_array *tr = m->private;
624 loff_t l;
625
626 mutex_lock(&event_mutex);
627
628 file = list_entry(&tr->events, struct ftrace_event_file, list);
629 for (l = 0; l <= *pos; ) {
630 file = t_next(m, file, &l);
631 if (!file)
632 break;
633 }
634 return file;
635 }
636
637 static void *
638 s_next(struct seq_file *m, void *v, loff_t *pos)
639 {
640 struct ftrace_event_file *file = v;
641 struct trace_array *tr = m->private;
642
643 (*pos)++;
644
645 list_for_each_entry_continue(file, &tr->events, list) {
646 if (file->flags & FTRACE_EVENT_FL_ENABLED)
647 return file;
648 }
649
650 return NULL;
651 }
652
653 static void *s_start(struct seq_file *m, loff_t *pos)
654 {
655 struct ftrace_event_file *file;
656 struct trace_array *tr = m->private;
657 loff_t l;
658
659 mutex_lock(&event_mutex);
660
661 file = list_entry(&tr->events, struct ftrace_event_file, list);
662 for (l = 0; l <= *pos; ) {
663 file = s_next(m, file, &l);
664 if (!file)
665 break;
666 }
667 return file;
668 }
669
670 static int t_show(struct seq_file *m, void *v)
671 {
672 struct ftrace_event_file *file = v;
673 struct ftrace_event_call *call = file->event_call;
674
675 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
676 seq_printf(m, "%s:", call->class->system);
677 seq_printf(m, "%s\n", call->name);
678
679 return 0;
680 }
681
682 static void t_stop(struct seq_file *m, void *p)
683 {
684 mutex_unlock(&event_mutex);
685 }
686
687 static ssize_t
688 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
689 loff_t *ppos)
690 {
691 struct ftrace_event_file *file;
692 unsigned long flags;
693 char buf[4] = "0";
694
695 mutex_lock(&event_mutex);
696 file = event_file_data(filp);
697 if (likely(file))
698 flags = file->flags;
699 mutex_unlock(&event_mutex);
700
701 if (!file)
702 return -ENODEV;
703
704 if (flags & FTRACE_EVENT_FL_ENABLED &&
705 !(flags & FTRACE_EVENT_FL_SOFT_DISABLED))
706 strcpy(buf, "1");
707
708 if (flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
709 flags & FTRACE_EVENT_FL_SOFT_MODE)
710 strcat(buf, "*");
711
712 strcat(buf, "\n");
713
714 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
715 }
716
717 static ssize_t
718 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
719 loff_t *ppos)
720 {
721 struct ftrace_event_file *file;
722 unsigned long val;
723 int ret;
724
725 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
726 if (ret)
727 return ret;
728
729 ret = tracing_update_buffers();
730 if (ret < 0)
731 return ret;
732
733 switch (val) {
734 case 0:
735 case 1:
736 ret = -ENODEV;
737 mutex_lock(&event_mutex);
738 file = event_file_data(filp);
739 if (likely(file))
740 ret = ftrace_event_enable_disable(file, val);
741 mutex_unlock(&event_mutex);
742 break;
743
744 default:
745 return -EINVAL;
746 }
747
748 *ppos += cnt;
749
750 return ret ? ret : cnt;
751 }
752
753 static ssize_t
754 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
755 loff_t *ppos)
756 {
757 const char set_to_char[4] = { '?', '0', '1', 'X' };
758 struct ftrace_subsystem_dir *dir = filp->private_data;
759 struct event_subsystem *system = dir->subsystem;
760 struct ftrace_event_call *call;
761 struct ftrace_event_file *file;
762 struct trace_array *tr = dir->tr;
763 char buf[2];
764 int set = 0;
765 int ret;
766
767 mutex_lock(&event_mutex);
768 list_for_each_entry(file, &tr->events, list) {
769 call = file->event_call;
770 if (!call->name || !call->class || !call->class->reg)
771 continue;
772
773 if (system && strcmp(call->class->system, system->name) != 0)
774 continue;
775
776 /*
777 * We need to find out if all the events are set
778 * or if all events or cleared, or if we have
779 * a mixture.
780 */
781 set |= (1 << !!(file->flags & FTRACE_EVENT_FL_ENABLED));
782
783 /*
784 * If we have a mixture, no need to look further.
785 */
786 if (set == 3)
787 break;
788 }
789 mutex_unlock(&event_mutex);
790
791 buf[0] = set_to_char[set];
792 buf[1] = '\n';
793
794 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
795
796 return ret;
797 }
798
799 static ssize_t
800 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
801 loff_t *ppos)
802 {
803 struct ftrace_subsystem_dir *dir = filp->private_data;
804 struct event_subsystem *system = dir->subsystem;
805 const char *name = NULL;
806 unsigned long val;
807 ssize_t ret;
808
809 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
810 if (ret)
811 return ret;
812
813 ret = tracing_update_buffers();
814 if (ret < 0)
815 return ret;
816
817 if (val != 0 && val != 1)
818 return -EINVAL;
819
820 /*
821 * Opening of "enable" adds a ref count to system,
822 * so the name is safe to use.
823 */
824 if (system)
825 name = system->name;
826
827 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
828 if (ret)
829 goto out;
830
831 ret = cnt;
832
833 out:
834 *ppos += cnt;
835
836 return ret;
837 }
838
839 enum {
840 FORMAT_HEADER = 1,
841 FORMAT_FIELD_SEPERATOR = 2,
842 FORMAT_PRINTFMT = 3,
843 };
844
845 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
846 {
847 struct ftrace_event_call *call = event_file_data(m->private);
848 struct list_head *common_head = &ftrace_common_fields;
849 struct list_head *head = trace_get_fields(call);
850 struct list_head *node = v;
851
852 (*pos)++;
853
854 switch ((unsigned long)v) {
855 case FORMAT_HEADER:
856 node = common_head;
857 break;
858
859 case FORMAT_FIELD_SEPERATOR:
860 node = head;
861 break;
862
863 case FORMAT_PRINTFMT:
864 /* all done */
865 return NULL;
866 }
867
868 node = node->prev;
869 if (node == common_head)
870 return (void *)FORMAT_FIELD_SEPERATOR;
871 else if (node == head)
872 return (void *)FORMAT_PRINTFMT;
873 else
874 return node;
875 }
876
877 static int f_show(struct seq_file *m, void *v)
878 {
879 struct ftrace_event_call *call = event_file_data(m->private);
880 struct ftrace_event_field *field;
881 const char *array_descriptor;
882
883 switch ((unsigned long)v) {
884 case FORMAT_HEADER:
885 seq_printf(m, "name: %s\n", call->name);
886 seq_printf(m, "ID: %d\n", call->event.type);
887 seq_printf(m, "format:\n");
888 return 0;
889
890 case FORMAT_FIELD_SEPERATOR:
891 seq_putc(m, '\n');
892 return 0;
893
894 case FORMAT_PRINTFMT:
895 seq_printf(m, "\nprint fmt: %s\n",
896 call->print_fmt);
897 return 0;
898 }
899
900 field = list_entry(v, struct ftrace_event_field, link);
901 /*
902 * Smartly shows the array type(except dynamic array).
903 * Normal:
904 * field:TYPE VAR
905 * If TYPE := TYPE[LEN], it is shown:
906 * field:TYPE VAR[LEN]
907 */
908 array_descriptor = strchr(field->type, '[');
909
910 if (!strncmp(field->type, "__data_loc", 10))
911 array_descriptor = NULL;
912
913 if (!array_descriptor)
914 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
915 field->type, field->name, field->offset,
916 field->size, !!field->is_signed);
917 else
918 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
919 (int)(array_descriptor - field->type),
920 field->type, field->name,
921 array_descriptor, field->offset,
922 field->size, !!field->is_signed);
923
924 return 0;
925 }
926
927 static void *f_start(struct seq_file *m, loff_t *pos)
928 {
929 void *p = (void *)FORMAT_HEADER;
930 loff_t l = 0;
931
932 /* ->stop() is called even if ->start() fails */
933 mutex_lock(&event_mutex);
934 if (!event_file_data(m->private))
935 return ERR_PTR(-ENODEV);
936
937 while (l < *pos && p)
938 p = f_next(m, p, &l);
939
940 return p;
941 }
942
943 static void f_stop(struct seq_file *m, void *p)
944 {
945 mutex_unlock(&event_mutex);
946 }
947
948 static const struct seq_operations trace_format_seq_ops = {
949 .start = f_start,
950 .next = f_next,
951 .stop = f_stop,
952 .show = f_show,
953 };
954
955 static int trace_format_open(struct inode *inode, struct file *file)
956 {
957 struct seq_file *m;
958 int ret;
959
960 ret = seq_open(file, &trace_format_seq_ops);
961 if (ret < 0)
962 return ret;
963
964 m = file->private_data;
965 m->private = file;
966
967 return 0;
968 }
969
970 static ssize_t
971 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
972 {
973 int id = (long)event_file_data(filp);
974 char buf[32];
975 int len;
976
977 if (*ppos)
978 return 0;
979
980 if (unlikely(!id))
981 return -ENODEV;
982
983 len = sprintf(buf, "%d\n", id);
984
985 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
986 }
987
988 static ssize_t
989 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
990 loff_t *ppos)
991 {
992 struct ftrace_event_call *call;
993 struct trace_seq *s;
994 int r = -ENODEV;
995
996 if (*ppos)
997 return 0;
998
999 s = kmalloc(sizeof(*s), GFP_KERNEL);
1000
1001 if (!s)
1002 return -ENOMEM;
1003
1004 trace_seq_init(s);
1005
1006 mutex_lock(&event_mutex);
1007 call = event_file_data(filp);
1008 if (call)
1009 print_event_filter(call, s);
1010 mutex_unlock(&event_mutex);
1011
1012 if (call)
1013 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1014
1015 kfree(s);
1016
1017 return r;
1018 }
1019
1020 static ssize_t
1021 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1022 loff_t *ppos)
1023 {
1024 struct ftrace_event_call *call;
1025 char *buf;
1026 int err = -ENODEV;
1027
1028 if (cnt >= PAGE_SIZE)
1029 return -EINVAL;
1030
1031 buf = (char *)__get_free_page(GFP_TEMPORARY);
1032 if (!buf)
1033 return -ENOMEM;
1034
1035 if (copy_from_user(buf, ubuf, cnt)) {
1036 free_page((unsigned long) buf);
1037 return -EFAULT;
1038 }
1039 buf[cnt] = '\0';
1040
1041 mutex_lock(&event_mutex);
1042 call = event_file_data(filp);
1043 if (call)
1044 err = apply_event_filter(call, buf);
1045 mutex_unlock(&event_mutex);
1046
1047 free_page((unsigned long) buf);
1048 if (err < 0)
1049 return err;
1050
1051 *ppos += cnt;
1052
1053 return cnt;
1054 }
1055
1056 static LIST_HEAD(event_subsystems);
1057
1058 static int subsystem_open(struct inode *inode, struct file *filp)
1059 {
1060 struct event_subsystem *system = NULL;
1061 struct ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1062 struct trace_array *tr;
1063 int ret;
1064
1065 /* Make sure the system still exists */
1066 mutex_lock(&trace_types_lock);
1067 mutex_lock(&event_mutex);
1068 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1069 list_for_each_entry(dir, &tr->systems, list) {
1070 if (dir == inode->i_private) {
1071 /* Don't open systems with no events */
1072 if (dir->nr_events) {
1073 __get_system_dir(dir);
1074 system = dir->subsystem;
1075 }
1076 goto exit_loop;
1077 }
1078 }
1079 }
1080 exit_loop:
1081 mutex_unlock(&event_mutex);
1082 mutex_unlock(&trace_types_lock);
1083
1084 if (!system)
1085 return -ENODEV;
1086
1087 /* Some versions of gcc think dir can be uninitialized here */
1088 WARN_ON(!dir);
1089
1090 /* Still need to increment the ref count of the system */
1091 if (trace_array_get(tr) < 0) {
1092 put_system(dir);
1093 return -ENODEV;
1094 }
1095
1096 ret = tracing_open_generic(inode, filp);
1097 if (ret < 0) {
1098 trace_array_put(tr);
1099 put_system(dir);
1100 }
1101
1102 return ret;
1103 }
1104
1105 static int system_tr_open(struct inode *inode, struct file *filp)
1106 {
1107 struct ftrace_subsystem_dir *dir;
1108 struct trace_array *tr = inode->i_private;
1109 int ret;
1110
1111 if (trace_array_get(tr) < 0)
1112 return -ENODEV;
1113
1114 /* Make a temporary dir that has no system but points to tr */
1115 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1116 if (!dir) {
1117 trace_array_put(tr);
1118 return -ENOMEM;
1119 }
1120
1121 dir->tr = tr;
1122
1123 ret = tracing_open_generic(inode, filp);
1124 if (ret < 0) {
1125 trace_array_put(tr);
1126 kfree(dir);
1127 }
1128
1129 filp->private_data = dir;
1130
1131 return ret;
1132 }
1133
1134 static int subsystem_release(struct inode *inode, struct file *file)
1135 {
1136 struct ftrace_subsystem_dir *dir = file->private_data;
1137
1138 trace_array_put(dir->tr);
1139
1140 /*
1141 * If dir->subsystem is NULL, then this is a temporary
1142 * descriptor that was made for a trace_array to enable
1143 * all subsystems.
1144 */
1145 if (dir->subsystem)
1146 put_system(dir);
1147 else
1148 kfree(dir);
1149
1150 return 0;
1151 }
1152
1153 static ssize_t
1154 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1155 loff_t *ppos)
1156 {
1157 struct ftrace_subsystem_dir *dir = filp->private_data;
1158 struct event_subsystem *system = dir->subsystem;
1159 struct trace_seq *s;
1160 int r;
1161
1162 if (*ppos)
1163 return 0;
1164
1165 s = kmalloc(sizeof(*s), GFP_KERNEL);
1166 if (!s)
1167 return -ENOMEM;
1168
1169 trace_seq_init(s);
1170
1171 print_subsystem_event_filter(system, s);
1172 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1173
1174 kfree(s);
1175
1176 return r;
1177 }
1178
1179 static ssize_t
1180 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1181 loff_t *ppos)
1182 {
1183 struct ftrace_subsystem_dir *dir = filp->private_data;
1184 char *buf;
1185 int err;
1186
1187 if (cnt >= PAGE_SIZE)
1188 return -EINVAL;
1189
1190 buf = (char *)__get_free_page(GFP_TEMPORARY);
1191 if (!buf)
1192 return -ENOMEM;
1193
1194 if (copy_from_user(buf, ubuf, cnt)) {
1195 free_page((unsigned long) buf);
1196 return -EFAULT;
1197 }
1198 buf[cnt] = '\0';
1199
1200 err = apply_subsystem_event_filter(dir, buf);
1201 free_page((unsigned long) buf);
1202 if (err < 0)
1203 return err;
1204
1205 *ppos += cnt;
1206
1207 return cnt;
1208 }
1209
1210 static ssize_t
1211 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1212 {
1213 int (*func)(struct trace_seq *s) = filp->private_data;
1214 struct trace_seq *s;
1215 int r;
1216
1217 if (*ppos)
1218 return 0;
1219
1220 s = kmalloc(sizeof(*s), GFP_KERNEL);
1221 if (!s)
1222 return -ENOMEM;
1223
1224 trace_seq_init(s);
1225
1226 func(s);
1227 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1228
1229 kfree(s);
1230
1231 return r;
1232 }
1233
1234 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1235 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1236 static int ftrace_event_release(struct inode *inode, struct file *file);
1237
1238 static const struct seq_operations show_event_seq_ops = {
1239 .start = t_start,
1240 .next = t_next,
1241 .show = t_show,
1242 .stop = t_stop,
1243 };
1244
1245 static const struct seq_operations show_set_event_seq_ops = {
1246 .start = s_start,
1247 .next = s_next,
1248 .show = t_show,
1249 .stop = t_stop,
1250 };
1251
1252 static const struct file_operations ftrace_avail_fops = {
1253 .open = ftrace_event_avail_open,
1254 .read = seq_read,
1255 .llseek = seq_lseek,
1256 .release = seq_release,
1257 };
1258
1259 static const struct file_operations ftrace_set_event_fops = {
1260 .open = ftrace_event_set_open,
1261 .read = seq_read,
1262 .write = ftrace_event_write,
1263 .llseek = seq_lseek,
1264 .release = ftrace_event_release,
1265 };
1266
1267 static const struct file_operations ftrace_enable_fops = {
1268 .open = tracing_open_generic,
1269 .read = event_enable_read,
1270 .write = event_enable_write,
1271 .llseek = default_llseek,
1272 };
1273
1274 static const struct file_operations ftrace_event_format_fops = {
1275 .open = trace_format_open,
1276 .read = seq_read,
1277 .llseek = seq_lseek,
1278 .release = seq_release,
1279 };
1280
1281 static const struct file_operations ftrace_event_id_fops = {
1282 .read = event_id_read,
1283 .llseek = default_llseek,
1284 };
1285
1286 static const struct file_operations ftrace_event_filter_fops = {
1287 .open = tracing_open_generic,
1288 .read = event_filter_read,
1289 .write = event_filter_write,
1290 .llseek = default_llseek,
1291 };
1292
1293 static const struct file_operations ftrace_subsystem_filter_fops = {
1294 .open = subsystem_open,
1295 .read = subsystem_filter_read,
1296 .write = subsystem_filter_write,
1297 .llseek = default_llseek,
1298 .release = subsystem_release,
1299 };
1300
1301 static const struct file_operations ftrace_system_enable_fops = {
1302 .open = subsystem_open,
1303 .read = system_enable_read,
1304 .write = system_enable_write,
1305 .llseek = default_llseek,
1306 .release = subsystem_release,
1307 };
1308
1309 static const struct file_operations ftrace_tr_enable_fops = {
1310 .open = system_tr_open,
1311 .read = system_enable_read,
1312 .write = system_enable_write,
1313 .llseek = default_llseek,
1314 .release = subsystem_release,
1315 };
1316
1317 static const struct file_operations ftrace_show_header_fops = {
1318 .open = tracing_open_generic,
1319 .read = show_header,
1320 .llseek = default_llseek,
1321 };
1322
1323 static int
1324 ftrace_event_open(struct inode *inode, struct file *file,
1325 const struct seq_operations *seq_ops)
1326 {
1327 struct seq_file *m;
1328 int ret;
1329
1330 ret = seq_open(file, seq_ops);
1331 if (ret < 0)
1332 return ret;
1333 m = file->private_data;
1334 /* copy tr over to seq ops */
1335 m->private = inode->i_private;
1336
1337 return ret;
1338 }
1339
1340 static int ftrace_event_release(struct inode *inode, struct file *file)
1341 {
1342 struct trace_array *tr = inode->i_private;
1343
1344 trace_array_put(tr);
1345
1346 return seq_release(inode, file);
1347 }
1348
1349 static int
1350 ftrace_event_avail_open(struct inode *inode, struct file *file)
1351 {
1352 const struct seq_operations *seq_ops = &show_event_seq_ops;
1353
1354 return ftrace_event_open(inode, file, seq_ops);
1355 }
1356
1357 static int
1358 ftrace_event_set_open(struct inode *inode, struct file *file)
1359 {
1360 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1361 struct trace_array *tr = inode->i_private;
1362 int ret;
1363
1364 if (trace_array_get(tr) < 0)
1365 return -ENODEV;
1366
1367 if ((file->f_mode & FMODE_WRITE) &&
1368 (file->f_flags & O_TRUNC))
1369 ftrace_clear_events(tr);
1370
1371 ret = ftrace_event_open(inode, file, seq_ops);
1372 if (ret < 0)
1373 trace_array_put(tr);
1374 return ret;
1375 }
1376
1377 static struct event_subsystem *
1378 create_new_subsystem(const char *name)
1379 {
1380 struct event_subsystem *system;
1381
1382 /* need to create new entry */
1383 system = kmalloc(sizeof(*system), GFP_KERNEL);
1384 if (!system)
1385 return NULL;
1386
1387 system->ref_count = 1;
1388
1389 /* Only allocate if dynamic (kprobes and modules) */
1390 if (!core_kernel_data((unsigned long)name)) {
1391 system->ref_count |= SYSTEM_FL_FREE_NAME;
1392 system->name = kstrdup(name, GFP_KERNEL);
1393 if (!system->name)
1394 goto out_free;
1395 } else
1396 system->name = name;
1397
1398 system->filter = NULL;
1399
1400 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1401 if (!system->filter)
1402 goto out_free;
1403
1404 list_add(&system->list, &event_subsystems);
1405
1406 return system;
1407
1408 out_free:
1409 if (system->ref_count & SYSTEM_FL_FREE_NAME)
1410 kfree(system->name);
1411 kfree(system);
1412 return NULL;
1413 }
1414
1415 static struct dentry *
1416 event_subsystem_dir(struct trace_array *tr, const char *name,
1417 struct ftrace_event_file *file, struct dentry *parent)
1418 {
1419 struct ftrace_subsystem_dir *dir;
1420 struct event_subsystem *system;
1421 struct dentry *entry;
1422
1423 /* First see if we did not already create this dir */
1424 list_for_each_entry(dir, &tr->systems, list) {
1425 system = dir->subsystem;
1426 if (strcmp(system->name, name) == 0) {
1427 dir->nr_events++;
1428 file->system = dir;
1429 return dir->entry;
1430 }
1431 }
1432
1433 /* Now see if the system itself exists. */
1434 list_for_each_entry(system, &event_subsystems, list) {
1435 if (strcmp(system->name, name) == 0)
1436 break;
1437 }
1438 /* Reset system variable when not found */
1439 if (&system->list == &event_subsystems)
1440 system = NULL;
1441
1442 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1443 if (!dir)
1444 goto out_fail;
1445
1446 if (!system) {
1447 system = create_new_subsystem(name);
1448 if (!system)
1449 goto out_free;
1450 } else
1451 __get_system(system);
1452
1453 dir->entry = debugfs_create_dir(name, parent);
1454 if (!dir->entry) {
1455 pr_warning("Failed to create system directory %s\n", name);
1456 __put_system(system);
1457 goto out_free;
1458 }
1459
1460 dir->tr = tr;
1461 dir->ref_count = 1;
1462 dir->nr_events = 1;
1463 dir->subsystem = system;
1464 file->system = dir;
1465
1466 entry = debugfs_create_file("filter", 0644, dir->entry, dir,
1467 &ftrace_subsystem_filter_fops);
1468 if (!entry) {
1469 kfree(system->filter);
1470 system->filter = NULL;
1471 pr_warning("Could not create debugfs '%s/filter' entry\n", name);
1472 }
1473
1474 trace_create_file("enable", 0644, dir->entry, dir,
1475 &ftrace_system_enable_fops);
1476
1477 list_add(&dir->list, &tr->systems);
1478
1479 return dir->entry;
1480
1481 out_free:
1482 kfree(dir);
1483 out_fail:
1484 /* Only print this message if failed on memory allocation */
1485 if (!dir || !system)
1486 pr_warning("No memory to create event subsystem %s\n",
1487 name);
1488 return NULL;
1489 }
1490
1491 static int
1492 event_create_dir(struct dentry *parent, struct ftrace_event_file *file)
1493 {
1494 struct ftrace_event_call *call = file->event_call;
1495 struct trace_array *tr = file->tr;
1496 struct list_head *head;
1497 struct dentry *d_events;
1498 int ret;
1499
1500 /*
1501 * If the trace point header did not define TRACE_SYSTEM
1502 * then the system would be called "TRACE_SYSTEM".
1503 */
1504 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1505 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1506 if (!d_events)
1507 return -ENOMEM;
1508 } else
1509 d_events = parent;
1510
1511 file->dir = debugfs_create_dir(call->name, d_events);
1512 if (!file->dir) {
1513 pr_warning("Could not create debugfs '%s' directory\n",
1514 call->name);
1515 return -1;
1516 }
1517
1518 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1519 trace_create_file("enable", 0644, file->dir, file,
1520 &ftrace_enable_fops);
1521
1522 #ifdef CONFIG_PERF_EVENTS
1523 if (call->event.type && call->class->reg)
1524 trace_create_file("id", 0444, file->dir,
1525 (void *)(long)call->event.type,
1526 &ftrace_event_id_fops);
1527 #endif
1528
1529 /*
1530 * Other events may have the same class. Only update
1531 * the fields if they are not already defined.
1532 */
1533 head = trace_get_fields(call);
1534 if (list_empty(head)) {
1535 ret = call->class->define_fields(call);
1536 if (ret < 0) {
1537 pr_warning("Could not initialize trace point"
1538 " events/%s\n", call->name);
1539 return -1;
1540 }
1541 }
1542 trace_create_file("filter", 0644, file->dir, call,
1543 &ftrace_event_filter_fops);
1544
1545 trace_create_file("format", 0444, file->dir, call,
1546 &ftrace_event_format_fops);
1547
1548 return 0;
1549 }
1550
1551 static void remove_event_from_tracers(struct ftrace_event_call *call)
1552 {
1553 struct ftrace_event_file *file;
1554 struct trace_array *tr;
1555
1556 do_for_each_event_file_safe(tr, file) {
1557 if (file->event_call != call)
1558 continue;
1559
1560 remove_event_file_dir(file);
1561 /*
1562 * The do_for_each_event_file_safe() is
1563 * a double loop. After finding the call for this
1564 * trace_array, we use break to jump to the next
1565 * trace_array.
1566 */
1567 break;
1568 } while_for_each_event_file();
1569 }
1570
1571 static void event_remove(struct ftrace_event_call *call)
1572 {
1573 struct trace_array *tr;
1574 struct ftrace_event_file *file;
1575
1576 do_for_each_event_file(tr, file) {
1577 if (file->event_call != call)
1578 continue;
1579 ftrace_event_enable_disable(file, 0);
1580 /*
1581 * The do_for_each_event_file() is
1582 * a double loop. After finding the call for this
1583 * trace_array, we use break to jump to the next
1584 * trace_array.
1585 */
1586 break;
1587 } while_for_each_event_file();
1588
1589 if (call->event.funcs)
1590 __unregister_ftrace_event(&call->event);
1591 remove_event_from_tracers(call);
1592 list_del(&call->list);
1593 }
1594
1595 static int event_init(struct ftrace_event_call *call)
1596 {
1597 int ret = 0;
1598
1599 if (WARN_ON(!call->name))
1600 return -EINVAL;
1601
1602 if (call->class->raw_init) {
1603 ret = call->class->raw_init(call);
1604 if (ret < 0 && ret != -ENOSYS)
1605 pr_warn("Could not initialize trace events/%s\n",
1606 call->name);
1607 }
1608
1609 return ret;
1610 }
1611
1612 static int
1613 __register_event(struct ftrace_event_call *call, struct module *mod)
1614 {
1615 int ret;
1616
1617 ret = event_init(call);
1618 if (ret < 0)
1619 return ret;
1620
1621 list_add(&call->list, &ftrace_events);
1622 call->mod = mod;
1623
1624 return 0;
1625 }
1626
1627 static struct ftrace_event_file *
1628 trace_create_new_event(struct ftrace_event_call *call,
1629 struct trace_array *tr)
1630 {
1631 struct ftrace_event_file *file;
1632
1633 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
1634 if (!file)
1635 return NULL;
1636
1637 file->event_call = call;
1638 file->tr = tr;
1639 atomic_set(&file->sm_ref, 0);
1640 list_add(&file->list, &tr->events);
1641
1642 return file;
1643 }
1644
1645 /* Add an event to a trace directory */
1646 static int
1647 __trace_add_new_event(struct ftrace_event_call *call, struct trace_array *tr)
1648 {
1649 struct ftrace_event_file *file;
1650
1651 file = trace_create_new_event(call, tr);
1652 if (!file)
1653 return -ENOMEM;
1654
1655 return event_create_dir(tr->event_dir, file);
1656 }
1657
1658 /*
1659 * Just create a decriptor for early init. A descriptor is required
1660 * for enabling events at boot. We want to enable events before
1661 * the filesystem is initialized.
1662 */
1663 static __init int
1664 __trace_early_add_new_event(struct ftrace_event_call *call,
1665 struct trace_array *tr)
1666 {
1667 struct ftrace_event_file *file;
1668
1669 file = trace_create_new_event(call, tr);
1670 if (!file)
1671 return -ENOMEM;
1672
1673 return 0;
1674 }
1675
1676 struct ftrace_module_file_ops;
1677 static void __add_event_to_tracers(struct ftrace_event_call *call);
1678
1679 /* Add an additional event_call dynamically */
1680 int trace_add_event_call(struct ftrace_event_call *call)
1681 {
1682 int ret;
1683 mutex_lock(&trace_types_lock);
1684 mutex_lock(&event_mutex);
1685
1686 ret = __register_event(call, NULL);
1687 if (ret >= 0)
1688 __add_event_to_tracers(call);
1689
1690 mutex_unlock(&event_mutex);
1691 mutex_unlock(&trace_types_lock);
1692 return ret;
1693 }
1694
1695 /*
1696 * Must be called under locking of trace_types_lock, event_mutex and
1697 * trace_event_sem.
1698 */
1699 static void __trace_remove_event_call(struct ftrace_event_call *call)
1700 {
1701 event_remove(call);
1702 trace_destroy_fields(call);
1703 destroy_preds(call);
1704 }
1705
1706 static int probe_remove_event_call(struct ftrace_event_call *call)
1707 {
1708 struct trace_array *tr;
1709 struct ftrace_event_file *file;
1710
1711 #ifdef CONFIG_PERF_EVENTS
1712 if (call->perf_refcount)
1713 return -EBUSY;
1714 #endif
1715 do_for_each_event_file(tr, file) {
1716 if (file->event_call != call)
1717 continue;
1718 /*
1719 * We can't rely on ftrace_event_enable_disable(enable => 0)
1720 * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
1721 * TRACE_REG_UNREGISTER.
1722 */
1723 if (file->flags & FTRACE_EVENT_FL_ENABLED)
1724 return -EBUSY;
1725 /*
1726 * The do_for_each_event_file_safe() is
1727 * a double loop. After finding the call for this
1728 * trace_array, we use break to jump to the next
1729 * trace_array.
1730 */
1731 break;
1732 } while_for_each_event_file();
1733
1734 __trace_remove_event_call(call);
1735
1736 return 0;
1737 }
1738
1739 /* Remove an event_call */
1740 int trace_remove_event_call(struct ftrace_event_call *call)
1741 {
1742 int ret;
1743
1744 mutex_lock(&trace_types_lock);
1745 mutex_lock(&event_mutex);
1746 down_write(&trace_event_sem);
1747 ret = probe_remove_event_call(call);
1748 up_write(&trace_event_sem);
1749 mutex_unlock(&event_mutex);
1750 mutex_unlock(&trace_types_lock);
1751
1752 return ret;
1753 }
1754
1755 #define for_each_event(event, start, end) \
1756 for (event = start; \
1757 (unsigned long)event < (unsigned long)end; \
1758 event++)
1759
1760 #ifdef CONFIG_MODULES
1761
1762 static void trace_module_add_events(struct module *mod)
1763 {
1764 struct ftrace_event_call **call, **start, **end;
1765
1766 start = mod->trace_events;
1767 end = mod->trace_events + mod->num_trace_events;
1768
1769 for_each_event(call, start, end) {
1770 __register_event(*call, mod);
1771 __add_event_to_tracers(*call);
1772 }
1773 }
1774
1775 static void trace_module_remove_events(struct module *mod)
1776 {
1777 struct ftrace_event_call *call, *p;
1778 bool clear_trace = false;
1779
1780 down_write(&trace_event_sem);
1781 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1782 if (call->mod == mod) {
1783 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
1784 clear_trace = true;
1785 __trace_remove_event_call(call);
1786 }
1787 }
1788 up_write(&trace_event_sem);
1789
1790 /*
1791 * It is safest to reset the ring buffer if the module being unloaded
1792 * registered any events that were used. The only worry is if
1793 * a new module gets loaded, and takes on the same id as the events
1794 * of this module. When printing out the buffer, traced events left
1795 * over from this module may be passed to the new module events and
1796 * unexpected results may occur.
1797 */
1798 if (clear_trace)
1799 tracing_reset_all_online_cpus();
1800 }
1801
1802 static int trace_module_notify(struct notifier_block *self,
1803 unsigned long val, void *data)
1804 {
1805 struct module *mod = data;
1806
1807 mutex_lock(&trace_types_lock);
1808 mutex_lock(&event_mutex);
1809 switch (val) {
1810 case MODULE_STATE_COMING:
1811 trace_module_add_events(mod);
1812 break;
1813 case MODULE_STATE_GOING:
1814 trace_module_remove_events(mod);
1815 break;
1816 }
1817 mutex_unlock(&event_mutex);
1818 mutex_unlock(&trace_types_lock);
1819
1820 return 0;
1821 }
1822
1823 static struct notifier_block trace_module_nb = {
1824 .notifier_call = trace_module_notify,
1825 .priority = 0,
1826 };
1827 #endif /* CONFIG_MODULES */
1828
1829 /* Create a new event directory structure for a trace directory. */
1830 static void
1831 __trace_add_event_dirs(struct trace_array *tr)
1832 {
1833 struct ftrace_event_call *call;
1834 int ret;
1835
1836 list_for_each_entry(call, &ftrace_events, list) {
1837 ret = __trace_add_new_event(call, tr);
1838 if (ret < 0)
1839 pr_warning("Could not create directory for event %s\n",
1840 call->name);
1841 }
1842 }
1843
1844 #ifdef CONFIG_DYNAMIC_FTRACE
1845
1846 /* Avoid typos */
1847 #define ENABLE_EVENT_STR "enable_event"
1848 #define DISABLE_EVENT_STR "disable_event"
1849
1850 struct event_probe_data {
1851 struct ftrace_event_file *file;
1852 unsigned long count;
1853 int ref;
1854 bool enable;
1855 };
1856
1857 static struct ftrace_event_file *
1858 find_event_file(struct trace_array *tr, const char *system, const char *event)
1859 {
1860 struct ftrace_event_file *file;
1861 struct ftrace_event_call *call;
1862
1863 list_for_each_entry(file, &tr->events, list) {
1864
1865 call = file->event_call;
1866
1867 if (!call->name || !call->class || !call->class->reg)
1868 continue;
1869
1870 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1871 continue;
1872
1873 if (strcmp(event, call->name) == 0 &&
1874 strcmp(system, call->class->system) == 0)
1875 return file;
1876 }
1877 return NULL;
1878 }
1879
1880 static void
1881 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1882 {
1883 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1884 struct event_probe_data *data = *pdata;
1885
1886 if (!data)
1887 return;
1888
1889 if (data->enable)
1890 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1891 else
1892 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1893 }
1894
1895 static void
1896 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1897 {
1898 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1899 struct event_probe_data *data = *pdata;
1900
1901 if (!data)
1902 return;
1903
1904 if (!data->count)
1905 return;
1906
1907 /* Skip if the event is in a state we want to switch to */
1908 if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
1909 return;
1910
1911 if (data->count != -1)
1912 (data->count)--;
1913
1914 event_enable_probe(ip, parent_ip, _data);
1915 }
1916
1917 static int
1918 event_enable_print(struct seq_file *m, unsigned long ip,
1919 struct ftrace_probe_ops *ops, void *_data)
1920 {
1921 struct event_probe_data *data = _data;
1922
1923 seq_printf(m, "%ps:", (void *)ip);
1924
1925 seq_printf(m, "%s:%s:%s",
1926 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
1927 data->file->event_call->class->system,
1928 data->file->event_call->name);
1929
1930 if (data->count == -1)
1931 seq_printf(m, ":unlimited\n");
1932 else
1933 seq_printf(m, ":count=%ld\n", data->count);
1934
1935 return 0;
1936 }
1937
1938 static int
1939 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
1940 void **_data)
1941 {
1942 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1943 struct event_probe_data *data = *pdata;
1944
1945 data->ref++;
1946 return 0;
1947 }
1948
1949 static void
1950 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
1951 void **_data)
1952 {
1953 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1954 struct event_probe_data *data = *pdata;
1955
1956 if (WARN_ON_ONCE(data->ref <= 0))
1957 return;
1958
1959 data->ref--;
1960 if (!data->ref) {
1961 /* Remove the SOFT_MODE flag */
1962 __ftrace_event_enable_disable(data->file, 0, 1);
1963 module_put(data->file->event_call->mod);
1964 kfree(data);
1965 }
1966 *pdata = NULL;
1967 }
1968
1969 static struct ftrace_probe_ops event_enable_probe_ops = {
1970 .func = event_enable_probe,
1971 .print = event_enable_print,
1972 .init = event_enable_init,
1973 .free = event_enable_free,
1974 };
1975
1976 static struct ftrace_probe_ops event_enable_count_probe_ops = {
1977 .func = event_enable_count_probe,
1978 .print = event_enable_print,
1979 .init = event_enable_init,
1980 .free = event_enable_free,
1981 };
1982
1983 static struct ftrace_probe_ops event_disable_probe_ops = {
1984 .func = event_enable_probe,
1985 .print = event_enable_print,
1986 .init = event_enable_init,
1987 .free = event_enable_free,
1988 };
1989
1990 static struct ftrace_probe_ops event_disable_count_probe_ops = {
1991 .func = event_enable_count_probe,
1992 .print = event_enable_print,
1993 .init = event_enable_init,
1994 .free = event_enable_free,
1995 };
1996
1997 static int
1998 event_enable_func(struct ftrace_hash *hash,
1999 char *glob, char *cmd, char *param, int enabled)
2000 {
2001 struct trace_array *tr = top_trace_array();
2002 struct ftrace_event_file *file;
2003 struct ftrace_probe_ops *ops;
2004 struct event_probe_data *data;
2005 const char *system;
2006 const char *event;
2007 char *number;
2008 bool enable;
2009 int ret;
2010
2011 /* hash funcs only work with set_ftrace_filter */
2012 if (!enabled || !param)
2013 return -EINVAL;
2014
2015 system = strsep(&param, ":");
2016 if (!param)
2017 return -EINVAL;
2018
2019 event = strsep(&param, ":");
2020
2021 mutex_lock(&event_mutex);
2022
2023 ret = -EINVAL;
2024 file = find_event_file(tr, system, event);
2025 if (!file)
2026 goto out;
2027
2028 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2029
2030 if (enable)
2031 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2032 else
2033 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2034
2035 if (glob[0] == '!') {
2036 unregister_ftrace_function_probe_func(glob+1, ops);
2037 ret = 0;
2038 goto out;
2039 }
2040
2041 ret = -ENOMEM;
2042 data = kzalloc(sizeof(*data), GFP_KERNEL);
2043 if (!data)
2044 goto out;
2045
2046 data->enable = enable;
2047 data->count = -1;
2048 data->file = file;
2049
2050 if (!param)
2051 goto out_reg;
2052
2053 number = strsep(&param, ":");
2054
2055 ret = -EINVAL;
2056 if (!strlen(number))
2057 goto out_free;
2058
2059 /*
2060 * We use the callback data field (which is a pointer)
2061 * as our counter.
2062 */
2063 ret = kstrtoul(number, 0, &data->count);
2064 if (ret)
2065 goto out_free;
2066
2067 out_reg:
2068 /* Don't let event modules unload while probe registered */
2069 ret = try_module_get(file->event_call->mod);
2070 if (!ret) {
2071 ret = -EBUSY;
2072 goto out_free;
2073 }
2074
2075 ret = __ftrace_event_enable_disable(file, 1, 1);
2076 if (ret < 0)
2077 goto out_put;
2078 ret = register_ftrace_function_probe(glob, ops, data);
2079 /*
2080 * The above returns on success the # of functions enabled,
2081 * but if it didn't find any functions it returns zero.
2082 * Consider no functions a failure too.
2083 */
2084 if (!ret) {
2085 ret = -ENOENT;
2086 goto out_disable;
2087 } else if (ret < 0)
2088 goto out_disable;
2089 /* Just return zero, not the number of enabled functions */
2090 ret = 0;
2091 out:
2092 mutex_unlock(&event_mutex);
2093 return ret;
2094
2095 out_disable:
2096 __ftrace_event_enable_disable(file, 0, 1);
2097 out_put:
2098 module_put(file->event_call->mod);
2099 out_free:
2100 kfree(data);
2101 goto out;
2102 }
2103
2104 static struct ftrace_func_command event_enable_cmd = {
2105 .name = ENABLE_EVENT_STR,
2106 .func = event_enable_func,
2107 };
2108
2109 static struct ftrace_func_command event_disable_cmd = {
2110 .name = DISABLE_EVENT_STR,
2111 .func = event_enable_func,
2112 };
2113
2114 static __init int register_event_cmds(void)
2115 {
2116 int ret;
2117
2118 ret = register_ftrace_command(&event_enable_cmd);
2119 if (WARN_ON(ret < 0))
2120 return ret;
2121 ret = register_ftrace_command(&event_disable_cmd);
2122 if (WARN_ON(ret < 0))
2123 unregister_ftrace_command(&event_enable_cmd);
2124 return ret;
2125 }
2126 #else
2127 static inline int register_event_cmds(void) { return 0; }
2128 #endif /* CONFIG_DYNAMIC_FTRACE */
2129
2130 /*
2131 * The top level array has already had its ftrace_event_file
2132 * descriptors created in order to allow for early events to
2133 * be recorded. This function is called after the debugfs has been
2134 * initialized, and we now have to create the files associated
2135 * to the events.
2136 */
2137 static __init void
2138 __trace_early_add_event_dirs(struct trace_array *tr)
2139 {
2140 struct ftrace_event_file *file;
2141 int ret;
2142
2143
2144 list_for_each_entry(file, &tr->events, list) {
2145 ret = event_create_dir(tr->event_dir, file);
2146 if (ret < 0)
2147 pr_warning("Could not create directory for event %s\n",
2148 file->event_call->name);
2149 }
2150 }
2151
2152 /*
2153 * For early boot up, the top trace array requires to have
2154 * a list of events that can be enabled. This must be done before
2155 * the filesystem is set up in order to allow events to be traced
2156 * early.
2157 */
2158 static __init void
2159 __trace_early_add_events(struct trace_array *tr)
2160 {
2161 struct ftrace_event_call *call;
2162 int ret;
2163
2164 list_for_each_entry(call, &ftrace_events, list) {
2165 /* Early boot up should not have any modules loaded */
2166 if (WARN_ON_ONCE(call->mod))
2167 continue;
2168
2169 ret = __trace_early_add_new_event(call, tr);
2170 if (ret < 0)
2171 pr_warning("Could not create early event %s\n",
2172 call->name);
2173 }
2174 }
2175
2176 /* Remove the event directory structure for a trace directory. */
2177 static void
2178 __trace_remove_event_dirs(struct trace_array *tr)
2179 {
2180 struct ftrace_event_file *file, *next;
2181
2182 list_for_each_entry_safe(file, next, &tr->events, list)
2183 remove_event_file_dir(file);
2184 }
2185
2186 static void __add_event_to_tracers(struct ftrace_event_call *call)
2187 {
2188 struct trace_array *tr;
2189
2190 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2191 __trace_add_new_event(call, tr);
2192 }
2193
2194 extern struct ftrace_event_call *__start_ftrace_events[];
2195 extern struct ftrace_event_call *__stop_ftrace_events[];
2196
2197 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2198
2199 static __init int setup_trace_event(char *str)
2200 {
2201 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2202 ring_buffer_expanded = true;
2203 tracing_selftest_disabled = true;
2204
2205 return 1;
2206 }
2207 __setup("trace_event=", setup_trace_event);
2208
2209 /* Expects to have event_mutex held when called */
2210 static int
2211 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2212 {
2213 struct dentry *d_events;
2214 struct dentry *entry;
2215
2216 entry = debugfs_create_file("set_event", 0644, parent,
2217 tr, &ftrace_set_event_fops);
2218 if (!entry) {
2219 pr_warning("Could not create debugfs 'set_event' entry\n");
2220 return -ENOMEM;
2221 }
2222
2223 d_events = debugfs_create_dir("events", parent);
2224 if (!d_events) {
2225 pr_warning("Could not create debugfs 'events' directory\n");
2226 return -ENOMEM;
2227 }
2228
2229 /* ring buffer internal formats */
2230 trace_create_file("header_page", 0444, d_events,
2231 ring_buffer_print_page_header,
2232 &ftrace_show_header_fops);
2233
2234 trace_create_file("header_event", 0444, d_events,
2235 ring_buffer_print_entry_header,
2236 &ftrace_show_header_fops);
2237
2238 trace_create_file("enable", 0644, d_events,
2239 tr, &ftrace_tr_enable_fops);
2240
2241 tr->event_dir = d_events;
2242
2243 return 0;
2244 }
2245
2246 /**
2247 * event_trace_add_tracer - add a instance of a trace_array to events
2248 * @parent: The parent dentry to place the files/directories for events in
2249 * @tr: The trace array associated with these events
2250 *
2251 * When a new instance is created, it needs to set up its events
2252 * directory, as well as other files associated with events. It also
2253 * creates the event hierachry in the @parent/events directory.
2254 *
2255 * Returns 0 on success.
2256 */
2257 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2258 {
2259 int ret;
2260
2261 mutex_lock(&event_mutex);
2262
2263 ret = create_event_toplevel_files(parent, tr);
2264 if (ret)
2265 goto out_unlock;
2266
2267 down_write(&trace_event_sem);
2268 __trace_add_event_dirs(tr);
2269 up_write(&trace_event_sem);
2270
2271 out_unlock:
2272 mutex_unlock(&event_mutex);
2273
2274 return ret;
2275 }
2276
2277 /*
2278 * The top trace array already had its file descriptors created.
2279 * Now the files themselves need to be created.
2280 */
2281 static __init int
2282 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2283 {
2284 int ret;
2285
2286 mutex_lock(&event_mutex);
2287
2288 ret = create_event_toplevel_files(parent, tr);
2289 if (ret)
2290 goto out_unlock;
2291
2292 down_write(&trace_event_sem);
2293 __trace_early_add_event_dirs(tr);
2294 up_write(&trace_event_sem);
2295
2296 out_unlock:
2297 mutex_unlock(&event_mutex);
2298
2299 return ret;
2300 }
2301
2302 int event_trace_del_tracer(struct trace_array *tr)
2303 {
2304 mutex_lock(&event_mutex);
2305
2306 /* Disable any running events */
2307 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
2308
2309 down_write(&trace_event_sem);
2310 __trace_remove_event_dirs(tr);
2311 debugfs_remove_recursive(tr->event_dir);
2312 up_write(&trace_event_sem);
2313
2314 tr->event_dir = NULL;
2315
2316 mutex_unlock(&event_mutex);
2317
2318 return 0;
2319 }
2320
2321 static __init int event_trace_memsetup(void)
2322 {
2323 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
2324 file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC);
2325 return 0;
2326 }
2327
2328 static __init int event_trace_enable(void)
2329 {
2330 struct trace_array *tr = top_trace_array();
2331 struct ftrace_event_call **iter, *call;
2332 char *buf = bootup_event_buf;
2333 char *token;
2334 int ret;
2335
2336 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
2337
2338 call = *iter;
2339 ret = event_init(call);
2340 if (!ret)
2341 list_add(&call->list, &ftrace_events);
2342 }
2343
2344 /*
2345 * We need the top trace array to have a working set of trace
2346 * points at early init, before the debug files and directories
2347 * are created. Create the file entries now, and attach them
2348 * to the actual file dentries later.
2349 */
2350 __trace_early_add_events(tr);
2351
2352 while (true) {
2353 token = strsep(&buf, ",");
2354
2355 if (!token)
2356 break;
2357 if (!*token)
2358 continue;
2359
2360 ret = ftrace_set_clr_event(tr, token, 1);
2361 if (ret)
2362 pr_warn("Failed to enable trace event: %s\n", token);
2363 }
2364
2365 trace_printk_start_comm();
2366
2367 register_event_cmds();
2368
2369 return 0;
2370 }
2371
2372 static __init int event_trace_init(void)
2373 {
2374 struct trace_array *tr;
2375 struct dentry *d_tracer;
2376 struct dentry *entry;
2377 int ret;
2378
2379 tr = top_trace_array();
2380
2381 d_tracer = tracing_init_dentry();
2382 if (!d_tracer)
2383 return 0;
2384
2385 entry = debugfs_create_file("available_events", 0444, d_tracer,
2386 tr, &ftrace_avail_fops);
2387 if (!entry)
2388 pr_warning("Could not create debugfs "
2389 "'available_events' entry\n");
2390
2391 if (trace_define_common_fields())
2392 pr_warning("tracing: Failed to allocate common fields");
2393
2394 ret = early_event_add_tracer(d_tracer, tr);
2395 if (ret)
2396 return ret;
2397
2398 #ifdef CONFIG_MODULES
2399 ret = register_module_notifier(&trace_module_nb);
2400 if (ret)
2401 pr_warning("Failed to register trace events module notifier\n");
2402 #endif
2403 return 0;
2404 }
2405 early_initcall(event_trace_memsetup);
2406 core_initcall(event_trace_enable);
2407 fs_initcall(event_trace_init);
2408
2409 #ifdef CONFIG_FTRACE_STARTUP_TEST
2410
2411 static DEFINE_SPINLOCK(test_spinlock);
2412 static DEFINE_SPINLOCK(test_spinlock_irq);
2413 static DEFINE_MUTEX(test_mutex);
2414
2415 static __init void test_work(struct work_struct *dummy)
2416 {
2417 spin_lock(&test_spinlock);
2418 spin_lock_irq(&test_spinlock_irq);
2419 udelay(1);
2420 spin_unlock_irq(&test_spinlock_irq);
2421 spin_unlock(&test_spinlock);
2422
2423 mutex_lock(&test_mutex);
2424 msleep(1);
2425 mutex_unlock(&test_mutex);
2426 }
2427
2428 static __init int event_test_thread(void *unused)
2429 {
2430 void *test_malloc;
2431
2432 test_malloc = kmalloc(1234, GFP_KERNEL);
2433 if (!test_malloc)
2434 pr_info("failed to kmalloc\n");
2435
2436 schedule_on_each_cpu(test_work);
2437
2438 kfree(test_malloc);
2439
2440 set_current_state(TASK_INTERRUPTIBLE);
2441 while (!kthread_should_stop())
2442 schedule();
2443
2444 return 0;
2445 }
2446
2447 /*
2448 * Do various things that may trigger events.
2449 */
2450 static __init void event_test_stuff(void)
2451 {
2452 struct task_struct *test_thread;
2453
2454 test_thread = kthread_run(event_test_thread, NULL, "test-events");
2455 msleep(1);
2456 kthread_stop(test_thread);
2457 }
2458
2459 /*
2460 * For every trace event defined, we will test each trace point separately,
2461 * and then by groups, and finally all trace points.
2462 */
2463 static __init void event_trace_self_tests(void)
2464 {
2465 struct ftrace_subsystem_dir *dir;
2466 struct ftrace_event_file *file;
2467 struct ftrace_event_call *call;
2468 struct event_subsystem *system;
2469 struct trace_array *tr;
2470 int ret;
2471
2472 tr = top_trace_array();
2473
2474 pr_info("Running tests on trace events:\n");
2475
2476 list_for_each_entry(file, &tr->events, list) {
2477
2478 call = file->event_call;
2479
2480 /* Only test those that have a probe */
2481 if (!call->class || !call->class->probe)
2482 continue;
2483
2484 /*
2485 * Testing syscall events here is pretty useless, but
2486 * we still do it if configured. But this is time consuming.
2487 * What we really need is a user thread to perform the
2488 * syscalls as we test.
2489 */
2490 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
2491 if (call->class->system &&
2492 strcmp(call->class->system, "syscalls") == 0)
2493 continue;
2494 #endif
2495
2496 pr_info("Testing event %s: ", call->name);
2497
2498 /*
2499 * If an event is already enabled, someone is using
2500 * it and the self test should not be on.
2501 */
2502 if (file->flags & FTRACE_EVENT_FL_ENABLED) {
2503 pr_warning("Enabled event during self test!\n");
2504 WARN_ON_ONCE(1);
2505 continue;
2506 }
2507
2508 ftrace_event_enable_disable(file, 1);
2509 event_test_stuff();
2510 ftrace_event_enable_disable(file, 0);
2511
2512 pr_cont("OK\n");
2513 }
2514
2515 /* Now test at the sub system level */
2516
2517 pr_info("Running tests on trace event systems:\n");
2518
2519 list_for_each_entry(dir, &tr->systems, list) {
2520
2521 system = dir->subsystem;
2522
2523 /* the ftrace system is special, skip it */
2524 if (strcmp(system->name, "ftrace") == 0)
2525 continue;
2526
2527 pr_info("Testing event system %s: ", system->name);
2528
2529 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
2530 if (WARN_ON_ONCE(ret)) {
2531 pr_warning("error enabling system %s\n",
2532 system->name);
2533 continue;
2534 }
2535
2536 event_test_stuff();
2537
2538 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
2539 if (WARN_ON_ONCE(ret)) {
2540 pr_warning("error disabling system %s\n",
2541 system->name);
2542 continue;
2543 }
2544
2545 pr_cont("OK\n");
2546 }
2547
2548 /* Test with all events enabled */
2549
2550 pr_info("Running tests on all trace events:\n");
2551 pr_info("Testing all events: ");
2552
2553 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
2554 if (WARN_ON_ONCE(ret)) {
2555 pr_warning("error enabling all events\n");
2556 return;
2557 }
2558
2559 event_test_stuff();
2560
2561 /* reset sysname */
2562 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
2563 if (WARN_ON_ONCE(ret)) {
2564 pr_warning("error disabling all events\n");
2565 return;
2566 }
2567
2568 pr_cont("OK\n");
2569 }
2570
2571 #ifdef CONFIG_FUNCTION_TRACER
2572
2573 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
2574
2575 static void
2576 function_test_events_call(unsigned long ip, unsigned long parent_ip,
2577 struct ftrace_ops *op, struct pt_regs *pt_regs)
2578 {
2579 struct ring_buffer_event *event;
2580 struct ring_buffer *buffer;
2581 struct ftrace_entry *entry;
2582 unsigned long flags;
2583 long disabled;
2584 int cpu;
2585 int pc;
2586
2587 pc = preempt_count();
2588 preempt_disable_notrace();
2589 cpu = raw_smp_processor_id();
2590 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
2591
2592 if (disabled != 1)
2593 goto out;
2594
2595 local_save_flags(flags);
2596
2597 event = trace_current_buffer_lock_reserve(&buffer,
2598 TRACE_FN, sizeof(*entry),
2599 flags, pc);
2600 if (!event)
2601 goto out;
2602 entry = ring_buffer_event_data(event);
2603 entry->ip = ip;
2604 entry->parent_ip = parent_ip;
2605
2606 trace_buffer_unlock_commit(buffer, event, flags, pc);
2607
2608 out:
2609 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
2610 preempt_enable_notrace();
2611 }
2612
2613 static struct ftrace_ops trace_ops __initdata =
2614 {
2615 .func = function_test_events_call,
2616 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
2617 };
2618
2619 static __init void event_trace_self_test_with_function(void)
2620 {
2621 int ret;
2622 ret = register_ftrace_function(&trace_ops);
2623 if (WARN_ON(ret < 0)) {
2624 pr_info("Failed to enable function tracer for event tests\n");
2625 return;
2626 }
2627 pr_info("Running tests again, along with the function tracer\n");
2628 event_trace_self_tests();
2629 unregister_ftrace_function(&trace_ops);
2630 }
2631 #else
2632 static __init void event_trace_self_test_with_function(void)
2633 {
2634 }
2635 #endif
2636
2637 static __init int event_trace_self_tests_init(void)
2638 {
2639 if (!tracing_selftest_disabled) {
2640 event_trace_self_tests();
2641 event_trace_self_test_with_function();
2642 }
2643
2644 return 0;
2645 }
2646
2647 late_initcall(event_trace_self_tests_init);
2648
2649 #endif
Linux kernel - Deliverables
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