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drbd: merge_bvec_fn: properly remap bvm->bi_bdev
[linux/fpc-iii.git] / kernel / trace / trace_events.c
blobe4c4efc4ba0d7d8bc85b17900de4e6a03d7178ab
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 LIST_HEAD(ftrace_events);
31 static LIST_HEAD(ftrace_common_fields);
32
33 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
34
35 static struct kmem_cache *field_cachep;
36 static struct kmem_cache *file_cachep;
37
38 #define SYSTEM_FL_FREE_NAME (1 << 31)
39
40 static inline int system_refcount(struct event_subsystem *system)
41 {
42 return system->ref_count & ~SYSTEM_FL_FREE_NAME;
43 }
44
45 static int system_refcount_inc(struct event_subsystem *system)
46 {
47 return (system->ref_count++) & ~SYSTEM_FL_FREE_NAME;
48 }
49
50 static int system_refcount_dec(struct event_subsystem *system)
51 {
52 return (--system->ref_count) & ~SYSTEM_FL_FREE_NAME;
53 }
54
55 /* Double loops, do not use break, only goto's work */
56 #define do_for_each_event_file(tr, file) \
57 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
58 list_for_each_entry(file, &tr->events, list)
59
60 #define do_for_each_event_file_safe(tr, file) \
61 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
62 struct ftrace_event_file *___n; \
63 list_for_each_entry_safe(file, ___n, &tr->events, list)
64
65 #define while_for_each_event_file() \
66 }
67
68 static struct list_head *
69 trace_get_fields(struct ftrace_event_call *event_call)
70 {
71 if (!event_call->class->get_fields)
72 return &event_call->class->fields;
73 return event_call->class->get_fields(event_call);
74 }
75
76 static struct ftrace_event_field *
77 __find_event_field(struct list_head *head, char *name)
78 {
79 struct ftrace_event_field *field;
80
81 list_for_each_entry(field, head, link) {
82 if (!strcmp(field->name, name))
83 return field;
84 }
85
86 return NULL;
87 }
88
89 struct ftrace_event_field *
90 trace_find_event_field(struct ftrace_event_call *call, char *name)
91 {
92 struct ftrace_event_field *field;
93 struct list_head *head;
94
95 field = __find_event_field(&ftrace_common_fields, name);
96 if (field)
97 return field;
98
99 head = trace_get_fields(call);
100 return __find_event_field(head, name);
101 }
102
103 static int __trace_define_field(struct list_head *head, const char *type,
104 const char *name, int offset, int size,
105 int is_signed, int filter_type)
106 {
107 struct ftrace_event_field *field;
108
109 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
110 if (!field)
111 return -ENOMEM;
112
113 field->name = name;
114 field->type = type;
115
116 if (filter_type == FILTER_OTHER)
117 field->filter_type = filter_assign_type(type);
118 else
119 field->filter_type = filter_type;
120
121 field->offset = offset;
122 field->size = size;
123 field->is_signed = is_signed;
124
125 list_add(&field->link, head);
126
127 return 0;
128 }
129
130 int trace_define_field(struct ftrace_event_call *call, const char *type,
131 const char *name, int offset, int size, int is_signed,
132 int filter_type)
133 {
134 struct list_head *head;
135
136 if (WARN_ON(!call->class))
137 return 0;
138
139 head = trace_get_fields(call);
140 return __trace_define_field(head, type, name, offset, size,
141 is_signed, filter_type);
142 }
143 EXPORT_SYMBOL_GPL(trace_define_field);
144
145 #define __common_field(type, item) \
146 ret = __trace_define_field(&ftrace_common_fields, #type, \
147 "common_" #item, \
148 offsetof(typeof(ent), item), \
149 sizeof(ent.item), \
150 is_signed_type(type), FILTER_OTHER); \
151 if (ret) \
152 return ret;
153
154 static int trace_define_common_fields(void)
155 {
156 int ret;
157 struct trace_entry ent;
158
159 __common_field(unsigned short, type);
160 __common_field(unsigned char, flags);
161 __common_field(unsigned char, preempt_count);
162 __common_field(int, pid);
163
164 return ret;
165 }
166
167 static void trace_destroy_fields(struct ftrace_event_call *call)
168 {
169 struct ftrace_event_field *field, *next;
170 struct list_head *head;
171
172 head = trace_get_fields(call);
173 list_for_each_entry_safe(field, next, head, link) {
174 list_del(&field->link);
175 kmem_cache_free(field_cachep, field);
176 }
177 }
178
179 int trace_event_raw_init(struct ftrace_event_call *call)
180 {
181 int id;
182
183 id = register_ftrace_event(&call->event);
184 if (!id)
185 return -ENODEV;
186
187 return 0;
188 }
189 EXPORT_SYMBOL_GPL(trace_event_raw_init);
190
191 int ftrace_event_reg(struct ftrace_event_call *call,
192 enum trace_reg type, void *data)
193 {
194 struct ftrace_event_file *file = data;
195
196 switch (type) {
197 case TRACE_REG_REGISTER:
198 return tracepoint_probe_register(call->name,
199 call->class->probe,
200 file);
201 case TRACE_REG_UNREGISTER:
202 tracepoint_probe_unregister(call->name,
203 call->class->probe,
204 file);
205 return 0;
206
207 #ifdef CONFIG_PERF_EVENTS
208 case TRACE_REG_PERF_REGISTER:
209 return tracepoint_probe_register(call->name,
210 call->class->perf_probe,
211 call);
212 case TRACE_REG_PERF_UNREGISTER:
213 tracepoint_probe_unregister(call->name,
214 call->class->perf_probe,
215 call);
216 return 0;
217 case TRACE_REG_PERF_OPEN:
218 case TRACE_REG_PERF_CLOSE:
219 case TRACE_REG_PERF_ADD:
220 case TRACE_REG_PERF_DEL:
221 return 0;
222 #endif
223 }
224 return 0;
225 }
226 EXPORT_SYMBOL_GPL(ftrace_event_reg);
227
228 void trace_event_enable_cmd_record(bool enable)
229 {
230 struct ftrace_event_file *file;
231 struct trace_array *tr;
232
233 mutex_lock(&event_mutex);
234 do_for_each_event_file(tr, file) {
235
236 if (!(file->flags & FTRACE_EVENT_FL_ENABLED))
237 continue;
238
239 if (enable) {
240 tracing_start_cmdline_record();
241 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
242 } else {
243 tracing_stop_cmdline_record();
244 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
245 }
246 } while_for_each_event_file();
247 mutex_unlock(&event_mutex);
248 }
249
250 static int __ftrace_event_enable_disable(struct ftrace_event_file *file,
251 int enable, int soft_disable)
252 {
253 struct ftrace_event_call *call = file->event_call;
254 int ret = 0;
255 int disable;
256
257 switch (enable) {
258 case 0:
259 /*
260 * When soft_disable is set and enable is cleared, the sm_ref
261 * reference counter is decremented. If it reaches 0, we want
262 * to clear the SOFT_DISABLED flag but leave the event in the
263 * state that it was. That is, if the event was enabled and
264 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
265 * is set we do not want the event to be enabled before we
266 * clear the bit.
267 *
268 * When soft_disable is not set but the SOFT_MODE flag is,
269 * we do nothing. Do not disable the tracepoint, otherwise
270 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
271 */
272 if (soft_disable) {
273 if (atomic_dec_return(&file->sm_ref) > 0)
274 break;
275 disable = file->flags & FTRACE_EVENT_FL_SOFT_DISABLED;
276 clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
277 } else
278 disable = !(file->flags & FTRACE_EVENT_FL_SOFT_MODE);
279
280 if (disable && (file->flags & FTRACE_EVENT_FL_ENABLED)) {
281 clear_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
282 if (file->flags & FTRACE_EVENT_FL_RECORDED_CMD) {
283 tracing_stop_cmdline_record();
284 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
285 }
286 call->class->reg(call, TRACE_REG_UNREGISTER, file);
287 }
288 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
289 if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
290 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
291 else
292 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
293 break;
294 case 1:
295 /*
296 * When soft_disable is set and enable is set, we want to
297 * register the tracepoint for the event, but leave the event
298 * as is. That means, if the event was already enabled, we do
299 * nothing (but set SOFT_MODE). If the event is disabled, we
300 * set SOFT_DISABLED before enabling the event tracepoint, so
301 * it still seems to be disabled.
302 */
303 if (!soft_disable)
304 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
305 else {
306 if (atomic_inc_return(&file->sm_ref) > 1)
307 break;
308 set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
309 }
310
311 if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) {
312
313 /* Keep the event disabled, when going to SOFT_MODE. */
314 if (soft_disable)
315 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
316
317 if (trace_flags & TRACE_ITER_RECORD_CMD) {
318 tracing_start_cmdline_record();
319 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
320 }
321 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
322 if (ret) {
323 tracing_stop_cmdline_record();
324 pr_info("event trace: Could not enable event "
325 "%s\n", call->name);
326 break;
327 }
328 set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
329
330 /* WAS_ENABLED gets set but never cleared. */
331 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
332 }
333 break;
334 }
335
336 return ret;
337 }
338
339 int trace_event_enable_disable(struct ftrace_event_file *file,
340 int enable, int soft_disable)
341 {
342 return __ftrace_event_enable_disable(file, enable, soft_disable);
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 remove_event_file_dir(struct ftrace_event_file *file)
425 {
426 struct dentry *dir = file->dir;
427 struct dentry *child;
428
429 if (dir) {
430 spin_lock(&dir->d_lock); /* probably unneeded */
431 list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
432 if (child->d_inode) /* probably unneeded */
433 child->d_inode->i_private = NULL;
434 }
435 spin_unlock(&dir->d_lock);
436
437 debugfs_remove_recursive(dir);
438 }
439
440 list_del(&file->list);
441 remove_subsystem(file->system);
442 free_event_filter(file->filter);
443 kmem_cache_free(file_cachep, file);
444 }
445
446 /*
447 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
448 */
449 static int
450 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
451 const char *sub, const char *event, int set)
452 {
453 struct ftrace_event_file *file;
454 struct ftrace_event_call *call;
455 int ret = -EINVAL;
456
457 list_for_each_entry(file, &tr->events, list) {
458
459 call = file->event_call;
460
461 if (!call->name || !call->class || !call->class->reg)
462 continue;
463
464 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
465 continue;
466
467 if (match &&
468 strcmp(match, call->name) != 0 &&
469 strcmp(match, call->class->system) != 0)
470 continue;
471
472 if (sub && strcmp(sub, call->class->system) != 0)
473 continue;
474
475 if (event && strcmp(event, call->name) != 0)
476 continue;
477
478 ftrace_event_enable_disable(file, set);
479
480 ret = 0;
481 }
482
483 return ret;
484 }
485
486 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
487 const char *sub, const char *event, int set)
488 {
489 int ret;
490
491 mutex_lock(&event_mutex);
492 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
493 mutex_unlock(&event_mutex);
494
495 return ret;
496 }
497
498 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
499 {
500 char *event = NULL, *sub = NULL, *match;
501
502 /*
503 * The buf format can be <subsystem>:<event-name>
504 * *:<event-name> means any event by that name.
505 * :<event-name> is the same.
506 *
507 * <subsystem>:* means all events in that subsystem
508 * <subsystem>: means the same.
509 *
510 * <name> (no ':') means all events in a subsystem with
511 * the name <name> or any event that matches <name>
512 */
513
514 match = strsep(&buf, ":");
515 if (buf) {
516 sub = match;
517 event = buf;
518 match = NULL;
519
520 if (!strlen(sub) || strcmp(sub, "*") == 0)
521 sub = NULL;
522 if (!strlen(event) || strcmp(event, "*") == 0)
523 event = NULL;
524 }
525
526 return __ftrace_set_clr_event(tr, match, sub, event, set);
527 }
528
529 /**
530 * trace_set_clr_event - enable or disable an event
531 * @system: system name to match (NULL for any system)
532 * @event: event name to match (NULL for all events, within system)
533 * @set: 1 to enable, 0 to disable
534 *
535 * This is a way for other parts of the kernel to enable or disable
536 * event recording.
537 *
538 * Returns 0 on success, -EINVAL if the parameters do not match any
539 * registered events.
540 */
541 int trace_set_clr_event(const char *system, const char *event, int set)
542 {
543 struct trace_array *tr = top_trace_array();
544
545 return __ftrace_set_clr_event(tr, NULL, system, event, set);
546 }
547 EXPORT_SYMBOL_GPL(trace_set_clr_event);
548
549 /* 128 should be much more than enough */
550 #define EVENT_BUF_SIZE 127
551
552 static ssize_t
553 ftrace_event_write(struct file *file, const char __user *ubuf,
554 size_t cnt, loff_t *ppos)
555 {
556 struct trace_parser parser;
557 struct seq_file *m = file->private_data;
558 struct trace_array *tr = m->private;
559 ssize_t read, ret;
560
561 if (!cnt)
562 return 0;
563
564 ret = tracing_update_buffers();
565 if (ret < 0)
566 return ret;
567
568 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
569 return -ENOMEM;
570
571 read = trace_get_user(&parser, ubuf, cnt, ppos);
572
573 if (read >= 0 && trace_parser_loaded((&parser))) {
574 int set = 1;
575
576 if (*parser.buffer == '!')
577 set = 0;
578
579 parser.buffer[parser.idx] = 0;
580
581 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
582 if (ret)
583 goto out_put;
584 }
585
586 ret = read;
587
588 out_put:
589 trace_parser_put(&parser);
590
591 return ret;
592 }
593
594 static void *
595 t_next(struct seq_file *m, void *v, loff_t *pos)
596 {
597 struct ftrace_event_file *file = v;
598 struct ftrace_event_call *call;
599 struct trace_array *tr = m->private;
600
601 (*pos)++;
602
603 list_for_each_entry_continue(file, &tr->events, list) {
604 call = file->event_call;
605 /*
606 * The ftrace subsystem is for showing formats only.
607 * They can not be enabled or disabled via the event files.
608 */
609 if (call->class && call->class->reg)
610 return file;
611 }
612
613 return NULL;
614 }
615
616 static void *t_start(struct seq_file *m, loff_t *pos)
617 {
618 struct ftrace_event_file *file;
619 struct trace_array *tr = m->private;
620 loff_t l;
621
622 mutex_lock(&event_mutex);
623
624 file = list_entry(&tr->events, struct ftrace_event_file, list);
625 for (l = 0; l <= *pos; ) {
626 file = t_next(m, file, &l);
627 if (!file)
628 break;
629 }
630 return file;
631 }
632
633 static void *
634 s_next(struct seq_file *m, void *v, loff_t *pos)
635 {
636 struct ftrace_event_file *file = v;
637 struct trace_array *tr = m->private;
638
639 (*pos)++;
640
641 list_for_each_entry_continue(file, &tr->events, list) {
642 if (file->flags & FTRACE_EVENT_FL_ENABLED)
643 return file;
644 }
645
646 return NULL;
647 }
648
649 static void *s_start(struct seq_file *m, loff_t *pos)
650 {
651 struct ftrace_event_file *file;
652 struct trace_array *tr = m->private;
653 loff_t l;
654
655 mutex_lock(&event_mutex);
656
657 file = list_entry(&tr->events, struct ftrace_event_file, list);
658 for (l = 0; l <= *pos; ) {
659 file = s_next(m, file, &l);
660 if (!file)
661 break;
662 }
663 return file;
664 }
665
666 static int t_show(struct seq_file *m, void *v)
667 {
668 struct ftrace_event_file *file = v;
669 struct ftrace_event_call *call = file->event_call;
670
671 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
672 seq_printf(m, "%s:", call->class->system);
673 seq_printf(m, "%s\n", call->name);
674
675 return 0;
676 }
677
678 static void t_stop(struct seq_file *m, void *p)
679 {
680 mutex_unlock(&event_mutex);
681 }
682
683 static ssize_t
684 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
685 loff_t *ppos)
686 {
687 struct ftrace_event_file *file;
688 unsigned long flags;
689 char buf[4] = "0";
690
691 mutex_lock(&event_mutex);
692 file = event_file_data(filp);
693 if (likely(file))
694 flags = file->flags;
695 mutex_unlock(&event_mutex);
696
697 if (!file)
698 return -ENODEV;
699
700 if (flags & FTRACE_EVENT_FL_ENABLED &&
701 !(flags & FTRACE_EVENT_FL_SOFT_DISABLED))
702 strcpy(buf, "1");
703
704 if (flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
705 flags & FTRACE_EVENT_FL_SOFT_MODE)
706 strcat(buf, "*");
707
708 strcat(buf, "\n");
709
710 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
711 }
712
713 static ssize_t
714 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
715 loff_t *ppos)
716 {
717 struct ftrace_event_file *file;
718 unsigned long val;
719 int ret;
720
721 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
722 if (ret)
723 return ret;
724
725 ret = tracing_update_buffers();
726 if (ret < 0)
727 return ret;
728
729 switch (val) {
730 case 0:
731 case 1:
732 ret = -ENODEV;
733 mutex_lock(&event_mutex);
734 file = event_file_data(filp);
735 if (likely(file))
736 ret = ftrace_event_enable_disable(file, val);
737 mutex_unlock(&event_mutex);
738 break;
739
740 default:
741 return -EINVAL;
742 }
743
744 *ppos += cnt;
745
746 return ret ? ret : cnt;
747 }
748
749 static ssize_t
750 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
751 loff_t *ppos)
752 {
753 const char set_to_char[4] = { '?', '0', '1', 'X' };
754 struct ftrace_subsystem_dir *dir = filp->private_data;
755 struct event_subsystem *system = dir->subsystem;
756 struct ftrace_event_call *call;
757 struct ftrace_event_file *file;
758 struct trace_array *tr = dir->tr;
759 char buf[2];
760 int set = 0;
761 int ret;
762
763 mutex_lock(&event_mutex);
764 list_for_each_entry(file, &tr->events, list) {
765 call = file->event_call;
766 if (!call->name || !call->class || !call->class->reg)
767 continue;
768
769 if (system && strcmp(call->class->system, system->name) != 0)
770 continue;
771
772 /*
773 * We need to find out if all the events are set
774 * or if all events or cleared, or if we have
775 * a mixture.
776 */
777 set |= (1 << !!(file->flags & FTRACE_EVENT_FL_ENABLED));
778
779 /*
780 * If we have a mixture, no need to look further.
781 */
782 if (set == 3)
783 break;
784 }
785 mutex_unlock(&event_mutex);
786
787 buf[0] = set_to_char[set];
788 buf[1] = '\n';
789
790 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
791
792 return ret;
793 }
794
795 static ssize_t
796 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
797 loff_t *ppos)
798 {
799 struct ftrace_subsystem_dir *dir = filp->private_data;
800 struct event_subsystem *system = dir->subsystem;
801 const char *name = NULL;
802 unsigned long val;
803 ssize_t ret;
804
805 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
806 if (ret)
807 return ret;
808
809 ret = tracing_update_buffers();
810 if (ret < 0)
811 return ret;
812
813 if (val != 0 && val != 1)
814 return -EINVAL;
815
816 /*
817 * Opening of "enable" adds a ref count to system,
818 * so the name is safe to use.
819 */
820 if (system)
821 name = system->name;
822
823 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
824 if (ret)
825 goto out;
826
827 ret = cnt;
828
829 out:
830 *ppos += cnt;
831
832 return ret;
833 }
834
835 enum {
836 FORMAT_HEADER = 1,
837 FORMAT_FIELD_SEPERATOR = 2,
838 FORMAT_PRINTFMT = 3,
839 };
840
841 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
842 {
843 struct ftrace_event_call *call = event_file_data(m->private);
844 struct list_head *common_head = &ftrace_common_fields;
845 struct list_head *head = trace_get_fields(call);
846 struct list_head *node = v;
847
848 (*pos)++;
849
850 switch ((unsigned long)v) {
851 case FORMAT_HEADER:
852 node = common_head;
853 break;
854
855 case FORMAT_FIELD_SEPERATOR:
856 node = head;
857 break;
858
859 case FORMAT_PRINTFMT:
860 /* all done */
861 return NULL;
862 }
863
864 node = node->prev;
865 if (node == common_head)
866 return (void *)FORMAT_FIELD_SEPERATOR;
867 else if (node == head)
868 return (void *)FORMAT_PRINTFMT;
869 else
870 return node;
871 }
872
873 static int f_show(struct seq_file *m, void *v)
874 {
875 struct ftrace_event_call *call = event_file_data(m->private);
876 struct ftrace_event_field *field;
877 const char *array_descriptor;
878
879 switch ((unsigned long)v) {
880 case FORMAT_HEADER:
881 seq_printf(m, "name: %s\n", call->name);
882 seq_printf(m, "ID: %d\n", call->event.type);
883 seq_printf(m, "format:\n");
884 return 0;
885
886 case FORMAT_FIELD_SEPERATOR:
887 seq_putc(m, '\n');
888 return 0;
889
890 case FORMAT_PRINTFMT:
891 seq_printf(m, "\nprint fmt: %s\n",
892 call->print_fmt);
893 return 0;
894 }
895
896 field = list_entry(v, struct ftrace_event_field, link);
897 /*
898 * Smartly shows the array type(except dynamic array).
899 * Normal:
900 * field:TYPE VAR
901 * If TYPE := TYPE[LEN], it is shown:
902 * field:TYPE VAR[LEN]
903 */
904 array_descriptor = strchr(field->type, '[');
905
906 if (!strncmp(field->type, "__data_loc", 10))
907 array_descriptor = NULL;
908
909 if (!array_descriptor)
910 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
911 field->type, field->name, field->offset,
912 field->size, !!field->is_signed);
913 else
914 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
915 (int)(array_descriptor - field->type),
916 field->type, field->name,
917 array_descriptor, field->offset,
918 field->size, !!field->is_signed);
919
920 return 0;
921 }
922
923 static void *f_start(struct seq_file *m, loff_t *pos)
924 {
925 void *p = (void *)FORMAT_HEADER;
926 loff_t l = 0;
927
928 /* ->stop() is called even if ->start() fails */
929 mutex_lock(&event_mutex);
930 if (!event_file_data(m->private))
931 return ERR_PTR(-ENODEV);
932
933 while (l < *pos && p)
934 p = f_next(m, p, &l);
935
936 return p;
937 }
938
939 static void f_stop(struct seq_file *m, void *p)
940 {
941 mutex_unlock(&event_mutex);
942 }
943
944 static const struct seq_operations trace_format_seq_ops = {
945 .start = f_start,
946 .next = f_next,
947 .stop = f_stop,
948 .show = f_show,
949 };
950
951 static int trace_format_open(struct inode *inode, struct file *file)
952 {
953 struct seq_file *m;
954 int ret;
955
956 ret = seq_open(file, &trace_format_seq_ops);
957 if (ret < 0)
958 return ret;
959
960 m = file->private_data;
961 m->private = file;
962
963 return 0;
964 }
965
966 static ssize_t
967 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
968 {
969 int id = (long)event_file_data(filp);
970 char buf[32];
971 int len;
972
973 if (*ppos)
974 return 0;
975
976 if (unlikely(!id))
977 return -ENODEV;
978
979 len = sprintf(buf, "%d\n", id);
980
981 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
982 }
983
984 static ssize_t
985 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
986 loff_t *ppos)
987 {
988 struct ftrace_event_file *file;
989 struct trace_seq *s;
990 int r = -ENODEV;
991
992 if (*ppos)
993 return 0;
994
995 s = kmalloc(sizeof(*s), GFP_KERNEL);
996
997 if (!s)
998 return -ENOMEM;
999
1000 trace_seq_init(s);
1001
1002 mutex_lock(&event_mutex);
1003 file = event_file_data(filp);
1004 if (file)
1005 print_event_filter(file, s);
1006 mutex_unlock(&event_mutex);
1007
1008 if (file)
1009 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1010
1011 kfree(s);
1012
1013 return r;
1014 }
1015
1016 static ssize_t
1017 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1018 loff_t *ppos)
1019 {
1020 struct ftrace_event_file *file;
1021 char *buf;
1022 int err = -ENODEV;
1023
1024 if (cnt >= PAGE_SIZE)
1025 return -EINVAL;
1026
1027 buf = (char *)__get_free_page(GFP_TEMPORARY);
1028 if (!buf)
1029 return -ENOMEM;
1030
1031 if (copy_from_user(buf, ubuf, cnt)) {
1032 free_page((unsigned long) buf);
1033 return -EFAULT;
1034 }
1035 buf[cnt] = '\0';
1036
1037 mutex_lock(&event_mutex);
1038 file = event_file_data(filp);
1039 if (file)
1040 err = apply_event_filter(file, buf);
1041 mutex_unlock(&event_mutex);
1042
1043 free_page((unsigned long) buf);
1044 if (err < 0)
1045 return err;
1046
1047 *ppos += cnt;
1048
1049 return cnt;
1050 }
1051
1052 static LIST_HEAD(event_subsystems);
1053
1054 static int subsystem_open(struct inode *inode, struct file *filp)
1055 {
1056 struct event_subsystem *system = NULL;
1057 struct ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1058 struct trace_array *tr;
1059 int ret;
1060
1061 if (tracing_is_disabled())
1062 return -ENODEV;
1063
1064 /* Make sure the system still exists */
1065 mutex_lock(&trace_types_lock);
1066 mutex_lock(&event_mutex);
1067 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1068 list_for_each_entry(dir, &tr->systems, list) {
1069 if (dir == inode->i_private) {
1070 /* Don't open systems with no events */
1071 if (dir->nr_events) {
1072 __get_system_dir(dir);
1073 system = dir->subsystem;
1074 }
1075 goto exit_loop;
1076 }
1077 }
1078 }
1079 exit_loop:
1080 mutex_unlock(&event_mutex);
1081 mutex_unlock(&trace_types_lock);
1082
1083 if (!system)
1084 return -ENODEV;
1085
1086 /* Some versions of gcc think dir can be uninitialized here */
1087 WARN_ON(!dir);
1088
1089 /* Still need to increment the ref count of the system */
1090 if (trace_array_get(tr) < 0) {
1091 put_system(dir);
1092 return -ENODEV;
1093 }
1094
1095 ret = tracing_open_generic(inode, filp);
1096 if (ret < 0) {
1097 trace_array_put(tr);
1098 put_system(dir);
1099 }
1100
1101 return ret;
1102 }
1103
1104 static int system_tr_open(struct inode *inode, struct file *filp)
1105 {
1106 struct ftrace_subsystem_dir *dir;
1107 struct trace_array *tr = inode->i_private;
1108 int ret;
1109
1110 if (tracing_is_disabled())
1111 return -ENODEV;
1112
1113 if (trace_array_get(tr) < 0)
1114 return -ENODEV;
1115
1116 /* Make a temporary dir that has no system but points to tr */
1117 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1118 if (!dir) {
1119 trace_array_put(tr);
1120 return -ENOMEM;
1121 }
1122
1123 dir->tr = tr;
1124
1125 ret = tracing_open_generic(inode, filp);
1126 if (ret < 0) {
1127 trace_array_put(tr);
1128 kfree(dir);
1129 return ret;
1130 }
1131
1132 filp->private_data = dir;
1133
1134 return 0;
1135 }
1136
1137 static int subsystem_release(struct inode *inode, struct file *file)
1138 {
1139 struct ftrace_subsystem_dir *dir = file->private_data;
1140
1141 trace_array_put(dir->tr);
1142
1143 /*
1144 * If dir->subsystem is NULL, then this is a temporary
1145 * descriptor that was made for a trace_array to enable
1146 * all subsystems.
1147 */
1148 if (dir->subsystem)
1149 put_system(dir);
1150 else
1151 kfree(dir);
1152
1153 return 0;
1154 }
1155
1156 static ssize_t
1157 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1158 loff_t *ppos)
1159 {
1160 struct ftrace_subsystem_dir *dir = filp->private_data;
1161 struct event_subsystem *system = dir->subsystem;
1162 struct trace_seq *s;
1163 int r;
1164
1165 if (*ppos)
1166 return 0;
1167
1168 s = kmalloc(sizeof(*s), GFP_KERNEL);
1169 if (!s)
1170 return -ENOMEM;
1171
1172 trace_seq_init(s);
1173
1174 print_subsystem_event_filter(system, s);
1175 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1176
1177 kfree(s);
1178
1179 return r;
1180 }
1181
1182 static ssize_t
1183 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1184 loff_t *ppos)
1185 {
1186 struct ftrace_subsystem_dir *dir = filp->private_data;
1187 char *buf;
1188 int err;
1189
1190 if (cnt >= PAGE_SIZE)
1191 return -EINVAL;
1192
1193 buf = (char *)__get_free_page(GFP_TEMPORARY);
1194 if (!buf)
1195 return -ENOMEM;
1196
1197 if (copy_from_user(buf, ubuf, cnt)) {
1198 free_page((unsigned long) buf);
1199 return -EFAULT;
1200 }
1201 buf[cnt] = '\0';
1202
1203 err = apply_subsystem_event_filter(dir, buf);
1204 free_page((unsigned long) buf);
1205 if (err < 0)
1206 return err;
1207
1208 *ppos += cnt;
1209
1210 return cnt;
1211 }
1212
1213 static ssize_t
1214 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1215 {
1216 int (*func)(struct trace_seq *s) = filp->private_data;
1217 struct trace_seq *s;
1218 int r;
1219
1220 if (*ppos)
1221 return 0;
1222
1223 s = kmalloc(sizeof(*s), GFP_KERNEL);
1224 if (!s)
1225 return -ENOMEM;
1226
1227 trace_seq_init(s);
1228
1229 func(s);
1230 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1231
1232 kfree(s);
1233
1234 return r;
1235 }
1236
1237 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1238 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1239 static int ftrace_event_release(struct inode *inode, struct file *file);
1240
1241 static const struct seq_operations show_event_seq_ops = {
1242 .start = t_start,
1243 .next = t_next,
1244 .show = t_show,
1245 .stop = t_stop,
1246 };
1247
1248 static const struct seq_operations show_set_event_seq_ops = {
1249 .start = s_start,
1250 .next = s_next,
1251 .show = t_show,
1252 .stop = t_stop,
1253 };
1254
1255 static const struct file_operations ftrace_avail_fops = {
1256 .open = ftrace_event_avail_open,
1257 .read = seq_read,
1258 .llseek = seq_lseek,
1259 .release = seq_release,
1260 };
1261
1262 static const struct file_operations ftrace_set_event_fops = {
1263 .open = ftrace_event_set_open,
1264 .read = seq_read,
1265 .write = ftrace_event_write,
1266 .llseek = seq_lseek,
1267 .release = ftrace_event_release,
1268 };
1269
1270 static const struct file_operations ftrace_enable_fops = {
1271 .open = tracing_open_generic,
1272 .read = event_enable_read,
1273 .write = event_enable_write,
1274 .llseek = default_llseek,
1275 };
1276
1277 static const struct file_operations ftrace_event_format_fops = {
1278 .open = trace_format_open,
1279 .read = seq_read,
1280 .llseek = seq_lseek,
1281 .release = seq_release,
1282 };
1283
1284 static const struct file_operations ftrace_event_id_fops = {
1285 .read = event_id_read,
1286 .llseek = default_llseek,
1287 };
1288
1289 static const struct file_operations ftrace_event_filter_fops = {
1290 .open = tracing_open_generic,
1291 .read = event_filter_read,
1292 .write = event_filter_write,
1293 .llseek = default_llseek,
1294 };
1295
1296 static const struct file_operations ftrace_subsystem_filter_fops = {
1297 .open = subsystem_open,
1298 .read = subsystem_filter_read,
1299 .write = subsystem_filter_write,
1300 .llseek = default_llseek,
1301 .release = subsystem_release,
1302 };
1303
1304 static const struct file_operations ftrace_system_enable_fops = {
1305 .open = subsystem_open,
1306 .read = system_enable_read,
1307 .write = system_enable_write,
1308 .llseek = default_llseek,
1309 .release = subsystem_release,
1310 };
1311
1312 static const struct file_operations ftrace_tr_enable_fops = {
1313 .open = system_tr_open,
1314 .read = system_enable_read,
1315 .write = system_enable_write,
1316 .llseek = default_llseek,
1317 .release = subsystem_release,
1318 };
1319
1320 static const struct file_operations ftrace_show_header_fops = {
1321 .open = tracing_open_generic,
1322 .read = show_header,
1323 .llseek = default_llseek,
1324 };
1325
1326 static int
1327 ftrace_event_open(struct inode *inode, struct file *file,
1328 const struct seq_operations *seq_ops)
1329 {
1330 struct seq_file *m;
1331 int ret;
1332
1333 ret = seq_open(file, seq_ops);
1334 if (ret < 0)
1335 return ret;
1336 m = file->private_data;
1337 /* copy tr over to seq ops */
1338 m->private = inode->i_private;
1339
1340 return ret;
1341 }
1342
1343 static int ftrace_event_release(struct inode *inode, struct file *file)
1344 {
1345 struct trace_array *tr = inode->i_private;
1346
1347 trace_array_put(tr);
1348
1349 return seq_release(inode, file);
1350 }
1351
1352 static int
1353 ftrace_event_avail_open(struct inode *inode, struct file *file)
1354 {
1355 const struct seq_operations *seq_ops = &show_event_seq_ops;
1356
1357 return ftrace_event_open(inode, file, seq_ops);
1358 }
1359
1360 static int
1361 ftrace_event_set_open(struct inode *inode, struct file *file)
1362 {
1363 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1364 struct trace_array *tr = inode->i_private;
1365 int ret;
1366
1367 if (trace_array_get(tr) < 0)
1368 return -ENODEV;
1369
1370 if ((file->f_mode & FMODE_WRITE) &&
1371 (file->f_flags & O_TRUNC))
1372 ftrace_clear_events(tr);
1373
1374 ret = ftrace_event_open(inode, file, seq_ops);
1375 if (ret < 0)
1376 trace_array_put(tr);
1377 return ret;
1378 }
1379
1380 static struct event_subsystem *
1381 create_new_subsystem(const char *name)
1382 {
1383 struct event_subsystem *system;
1384
1385 /* need to create new entry */
1386 system = kmalloc(sizeof(*system), GFP_KERNEL);
1387 if (!system)
1388 return NULL;
1389
1390 system->ref_count = 1;
1391
1392 /* Only allocate if dynamic (kprobes and modules) */
1393 if (!core_kernel_data((unsigned long)name)) {
1394 system->ref_count |= SYSTEM_FL_FREE_NAME;
1395 system->name = kstrdup(name, GFP_KERNEL);
1396 if (!system->name)
1397 goto out_free;
1398 } else
1399 system->name = name;
1400
1401 system->filter = NULL;
1402
1403 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1404 if (!system->filter)
1405 goto out_free;
1406
1407 list_add(&system->list, &event_subsystems);
1408
1409 return system;
1410
1411 out_free:
1412 if (system->ref_count & SYSTEM_FL_FREE_NAME)
1413 kfree(system->name);
1414 kfree(system);
1415 return NULL;
1416 }
1417
1418 static struct dentry *
1419 event_subsystem_dir(struct trace_array *tr, const char *name,
1420 struct ftrace_event_file *file, struct dentry *parent)
1421 {
1422 struct ftrace_subsystem_dir *dir;
1423 struct event_subsystem *system;
1424 struct dentry *entry;
1425
1426 /* First see if we did not already create this dir */
1427 list_for_each_entry(dir, &tr->systems, list) {
1428 system = dir->subsystem;
1429 if (strcmp(system->name, name) == 0) {
1430 dir->nr_events++;
1431 file->system = dir;
1432 return dir->entry;
1433 }
1434 }
1435
1436 /* Now see if the system itself exists. */
1437 list_for_each_entry(system, &event_subsystems, list) {
1438 if (strcmp(system->name, name) == 0)
1439 break;
1440 }
1441 /* Reset system variable when not found */
1442 if (&system->list == &event_subsystems)
1443 system = NULL;
1444
1445 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1446 if (!dir)
1447 goto out_fail;
1448
1449 if (!system) {
1450 system = create_new_subsystem(name);
1451 if (!system)
1452 goto out_free;
1453 } else
1454 __get_system(system);
1455
1456 dir->entry = debugfs_create_dir(name, parent);
1457 if (!dir->entry) {
1458 pr_warning("Failed to create system directory %s\n", name);
1459 __put_system(system);
1460 goto out_free;
1461 }
1462
1463 dir->tr = tr;
1464 dir->ref_count = 1;
1465 dir->nr_events = 1;
1466 dir->subsystem = system;
1467 file->system = dir;
1468
1469 entry = debugfs_create_file("filter", 0644, dir->entry, dir,
1470 &ftrace_subsystem_filter_fops);
1471 if (!entry) {
1472 kfree(system->filter);
1473 system->filter = NULL;
1474 pr_warning("Could not create debugfs '%s/filter' entry\n", name);
1475 }
1476
1477 trace_create_file("enable", 0644, dir->entry, dir,
1478 &ftrace_system_enable_fops);
1479
1480 list_add(&dir->list, &tr->systems);
1481
1482 return dir->entry;
1483
1484 out_free:
1485 kfree(dir);
1486 out_fail:
1487 /* Only print this message if failed on memory allocation */
1488 if (!dir || !system)
1489 pr_warning("No memory to create event subsystem %s\n",
1490 name);
1491 return NULL;
1492 }
1493
1494 static int
1495 event_create_dir(struct dentry *parent, struct ftrace_event_file *file)
1496 {
1497 struct ftrace_event_call *call = file->event_call;
1498 struct trace_array *tr = file->tr;
1499 struct list_head *head;
1500 struct dentry *d_events;
1501 int ret;
1502
1503 /*
1504 * If the trace point header did not define TRACE_SYSTEM
1505 * then the system would be called "TRACE_SYSTEM".
1506 */
1507 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1508 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1509 if (!d_events)
1510 return -ENOMEM;
1511 } else
1512 d_events = parent;
1513
1514 file->dir = debugfs_create_dir(call->name, d_events);
1515 if (!file->dir) {
1516 pr_warning("Could not create debugfs '%s' directory\n",
1517 call->name);
1518 return -1;
1519 }
1520
1521 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1522 trace_create_file("enable", 0644, file->dir, file,
1523 &ftrace_enable_fops);
1524
1525 #ifdef CONFIG_PERF_EVENTS
1526 if (call->event.type && call->class->reg)
1527 trace_create_file("id", 0444, file->dir,
1528 (void *)(long)call->event.type,
1529 &ftrace_event_id_fops);
1530 #endif
1531
1532 /*
1533 * Other events may have the same class. Only update
1534 * the fields if they are not already defined.
1535 */
1536 head = trace_get_fields(call);
1537 if (list_empty(head)) {
1538 ret = call->class->define_fields(call);
1539 if (ret < 0) {
1540 pr_warning("Could not initialize trace point"
1541 " events/%s\n", call->name);
1542 return -1;
1543 }
1544 }
1545 trace_create_file("filter", 0644, file->dir, file,
1546 &ftrace_event_filter_fops);
1547
1548 trace_create_file("trigger", 0644, file->dir, file,
1549 &event_trigger_fops);
1550
1551 trace_create_file("format", 0444, file->dir, call,
1552 &ftrace_event_format_fops);
1553
1554 return 0;
1555 }
1556
1557 static void remove_event_from_tracers(struct ftrace_event_call *call)
1558 {
1559 struct ftrace_event_file *file;
1560 struct trace_array *tr;
1561
1562 do_for_each_event_file_safe(tr, file) {
1563 if (file->event_call != call)
1564 continue;
1565
1566 remove_event_file_dir(file);
1567 /*
1568 * The do_for_each_event_file_safe() is
1569 * a double loop. After finding the call for this
1570 * trace_array, we use break to jump to the next
1571 * trace_array.
1572 */
1573 break;
1574 } while_for_each_event_file();
1575 }
1576
1577 static void event_remove(struct ftrace_event_call *call)
1578 {
1579 struct trace_array *tr;
1580 struct ftrace_event_file *file;
1581
1582 do_for_each_event_file(tr, file) {
1583 if (file->event_call != call)
1584 continue;
1585 ftrace_event_enable_disable(file, 0);
1586 destroy_preds(file);
1587 /*
1588 * The do_for_each_event_file() is
1589 * a double loop. After finding the call for this
1590 * trace_array, we use break to jump to the next
1591 * trace_array.
1592 */
1593 break;
1594 } while_for_each_event_file();
1595
1596 if (call->event.funcs)
1597 __unregister_ftrace_event(&call->event);
1598 remove_event_from_tracers(call);
1599 list_del(&call->list);
1600 }
1601
1602 static int event_init(struct ftrace_event_call *call)
1603 {
1604 int ret = 0;
1605
1606 if (WARN_ON(!call->name))
1607 return -EINVAL;
1608
1609 if (call->class->raw_init) {
1610 ret = call->class->raw_init(call);
1611 if (ret < 0 && ret != -ENOSYS)
1612 pr_warn("Could not initialize trace events/%s\n",
1613 call->name);
1614 }
1615
1616 return ret;
1617 }
1618
1619 static int
1620 __register_event(struct ftrace_event_call *call, struct module *mod)
1621 {
1622 int ret;
1623
1624 ret = event_init(call);
1625 if (ret < 0)
1626 return ret;
1627
1628 list_add(&call->list, &ftrace_events);
1629 call->mod = mod;
1630
1631 return 0;
1632 }
1633
1634 static struct ftrace_event_file *
1635 trace_create_new_event(struct ftrace_event_call *call,
1636 struct trace_array *tr)
1637 {
1638 struct ftrace_event_file *file;
1639
1640 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
1641 if (!file)
1642 return NULL;
1643
1644 file->event_call = call;
1645 file->tr = tr;
1646 atomic_set(&file->sm_ref, 0);
1647 atomic_set(&file->tm_ref, 0);
1648 INIT_LIST_HEAD(&file->triggers);
1649 list_add(&file->list, &tr->events);
1650
1651 return file;
1652 }
1653
1654 /* Add an event to a trace directory */
1655 static int
1656 __trace_add_new_event(struct ftrace_event_call *call, struct trace_array *tr)
1657 {
1658 struct ftrace_event_file *file;
1659
1660 file = trace_create_new_event(call, tr);
1661 if (!file)
1662 return -ENOMEM;
1663
1664 return event_create_dir(tr->event_dir, file);
1665 }
1666
1667 /*
1668 * Just create a decriptor for early init. A descriptor is required
1669 * for enabling events at boot. We want to enable events before
1670 * the filesystem is initialized.
1671 */
1672 static __init int
1673 __trace_early_add_new_event(struct ftrace_event_call *call,
1674 struct trace_array *tr)
1675 {
1676 struct ftrace_event_file *file;
1677
1678 file = trace_create_new_event(call, tr);
1679 if (!file)
1680 return -ENOMEM;
1681
1682 return 0;
1683 }
1684
1685 struct ftrace_module_file_ops;
1686 static void __add_event_to_tracers(struct ftrace_event_call *call);
1687
1688 /* Add an additional event_call dynamically */
1689 int trace_add_event_call(struct ftrace_event_call *call)
1690 {
1691 int ret;
1692 mutex_lock(&trace_types_lock);
1693 mutex_lock(&event_mutex);
1694
1695 ret = __register_event(call, NULL);
1696 if (ret >= 0)
1697 __add_event_to_tracers(call);
1698
1699 mutex_unlock(&event_mutex);
1700 mutex_unlock(&trace_types_lock);
1701 return ret;
1702 }
1703
1704 /*
1705 * Must be called under locking of trace_types_lock, event_mutex and
1706 * trace_event_sem.
1707 */
1708 static void __trace_remove_event_call(struct ftrace_event_call *call)
1709 {
1710 event_remove(call);
1711 trace_destroy_fields(call);
1712 destroy_call_preds(call);
1713 }
1714
1715 static int probe_remove_event_call(struct ftrace_event_call *call)
1716 {
1717 struct trace_array *tr;
1718 struct ftrace_event_file *file;
1719
1720 #ifdef CONFIG_PERF_EVENTS
1721 if (call->perf_refcount)
1722 return -EBUSY;
1723 #endif
1724 do_for_each_event_file(tr, file) {
1725 if (file->event_call != call)
1726 continue;
1727 /*
1728 * We can't rely on ftrace_event_enable_disable(enable => 0)
1729 * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
1730 * TRACE_REG_UNREGISTER.
1731 */
1732 if (file->flags & FTRACE_EVENT_FL_ENABLED)
1733 return -EBUSY;
1734 /*
1735 * The do_for_each_event_file_safe() is
1736 * a double loop. After finding the call for this
1737 * trace_array, we use break to jump to the next
1738 * trace_array.
1739 */
1740 break;
1741 } while_for_each_event_file();
1742
1743 __trace_remove_event_call(call);
1744
1745 return 0;
1746 }
1747
1748 /* Remove an event_call */
1749 int trace_remove_event_call(struct ftrace_event_call *call)
1750 {
1751 int ret;
1752
1753 mutex_lock(&trace_types_lock);
1754 mutex_lock(&event_mutex);
1755 down_write(&trace_event_sem);
1756 ret = probe_remove_event_call(call);
1757 up_write(&trace_event_sem);
1758 mutex_unlock(&event_mutex);
1759 mutex_unlock(&trace_types_lock);
1760
1761 return ret;
1762 }
1763
1764 #define for_each_event(event, start, end) \
1765 for (event = start; \
1766 (unsigned long)event < (unsigned long)end; \
1767 event++)
1768
1769 #ifdef CONFIG_MODULES
1770
1771 static void trace_module_add_events(struct module *mod)
1772 {
1773 struct ftrace_event_call **call, **start, **end;
1774
1775 if (!mod->num_trace_events)
1776 return;
1777
1778 /* Don't add infrastructure for mods without tracepoints */
1779 if (trace_module_has_bad_taint(mod)) {
1780 pr_err("%s: module has bad taint, not creating trace events\n",
1781 mod->name);
1782 return;
1783 }
1784
1785 start = mod->trace_events;
1786 end = mod->trace_events + mod->num_trace_events;
1787
1788 for_each_event(call, start, end) {
1789 __register_event(*call, mod);
1790 __add_event_to_tracers(*call);
1791 }
1792 }
1793
1794 static void trace_module_remove_events(struct module *mod)
1795 {
1796 struct ftrace_event_call *call, *p;
1797 bool clear_trace = false;
1798
1799 down_write(&trace_event_sem);
1800 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1801 if (call->mod == mod) {
1802 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
1803 clear_trace = true;
1804 __trace_remove_event_call(call);
1805 }
1806 }
1807 up_write(&trace_event_sem);
1808
1809 /*
1810 * It is safest to reset the ring buffer if the module being unloaded
1811 * registered any events that were used. The only worry is if
1812 * a new module gets loaded, and takes on the same id as the events
1813 * of this module. When printing out the buffer, traced events left
1814 * over from this module may be passed to the new module events and
1815 * unexpected results may occur.
1816 */
1817 if (clear_trace)
1818 tracing_reset_all_online_cpus();
1819 }
1820
1821 static int trace_module_notify(struct notifier_block *self,
1822 unsigned long val, void *data)
1823 {
1824 struct module *mod = data;
1825
1826 mutex_lock(&trace_types_lock);
1827 mutex_lock(&event_mutex);
1828 switch (val) {
1829 case MODULE_STATE_COMING:
1830 trace_module_add_events(mod);
1831 break;
1832 case MODULE_STATE_GOING:
1833 trace_module_remove_events(mod);
1834 break;
1835 }
1836 mutex_unlock(&event_mutex);
1837 mutex_unlock(&trace_types_lock);
1838
1839 return 0;
1840 }
1841
1842 static struct notifier_block trace_module_nb = {
1843 .notifier_call = trace_module_notify,
1844 .priority = 0,
1845 };
1846 #endif /* CONFIG_MODULES */
1847
1848 /* Create a new event directory structure for a trace directory. */
1849 static void
1850 __trace_add_event_dirs(struct trace_array *tr)
1851 {
1852 struct ftrace_event_call *call;
1853 int ret;
1854
1855 list_for_each_entry(call, &ftrace_events, list) {
1856 ret = __trace_add_new_event(call, tr);
1857 if (ret < 0)
1858 pr_warning("Could not create directory for event %s\n",
1859 call->name);
1860 }
1861 }
1862
1863 struct ftrace_event_file *
1864 find_event_file(struct trace_array *tr, const char *system, const char *event)
1865 {
1866 struct ftrace_event_file *file;
1867 struct ftrace_event_call *call;
1868
1869 list_for_each_entry(file, &tr->events, list) {
1870
1871 call = file->event_call;
1872
1873 if (!call->name || !call->class || !call->class->reg)
1874 continue;
1875
1876 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1877 continue;
1878
1879 if (strcmp(event, call->name) == 0 &&
1880 strcmp(system, call->class->system) == 0)
1881 return file;
1882 }
1883 return NULL;
1884 }
1885
1886 #ifdef CONFIG_DYNAMIC_FTRACE
1887
1888 /* Avoid typos */
1889 #define ENABLE_EVENT_STR "enable_event"
1890 #define DISABLE_EVENT_STR "disable_event"
1891
1892 struct event_probe_data {
1893 struct ftrace_event_file *file;
1894 unsigned long count;
1895 int ref;
1896 bool enable;
1897 };
1898
1899 static void
1900 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1901 {
1902 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1903 struct event_probe_data *data = *pdata;
1904
1905 if (!data)
1906 return;
1907
1908 if (data->enable)
1909 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1910 else
1911 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1912 }
1913
1914 static void
1915 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1916 {
1917 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1918 struct event_probe_data *data = *pdata;
1919
1920 if (!data)
1921 return;
1922
1923 if (!data->count)
1924 return;
1925
1926 /* Skip if the event is in a state we want to switch to */
1927 if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
1928 return;
1929
1930 if (data->count != -1)
1931 (data->count)--;
1932
1933 event_enable_probe(ip, parent_ip, _data);
1934 }
1935
1936 static int
1937 event_enable_print(struct seq_file *m, unsigned long ip,
1938 struct ftrace_probe_ops *ops, void *_data)
1939 {
1940 struct event_probe_data *data = _data;
1941
1942 seq_printf(m, "%ps:", (void *)ip);
1943
1944 seq_printf(m, "%s:%s:%s",
1945 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
1946 data->file->event_call->class->system,
1947 data->file->event_call->name);
1948
1949 if (data->count == -1)
1950 seq_printf(m, ":unlimited\n");
1951 else
1952 seq_printf(m, ":count=%ld\n", data->count);
1953
1954 return 0;
1955 }
1956
1957 static int
1958 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
1959 void **_data)
1960 {
1961 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1962 struct event_probe_data *data = *pdata;
1963
1964 data->ref++;
1965 return 0;
1966 }
1967
1968 static void
1969 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
1970 void **_data)
1971 {
1972 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1973 struct event_probe_data *data = *pdata;
1974
1975 if (WARN_ON_ONCE(data->ref <= 0))
1976 return;
1977
1978 data->ref--;
1979 if (!data->ref) {
1980 /* Remove the SOFT_MODE flag */
1981 __ftrace_event_enable_disable(data->file, 0, 1);
1982 module_put(data->file->event_call->mod);
1983 kfree(data);
1984 }
1985 *pdata = NULL;
1986 }
1987
1988 static struct ftrace_probe_ops event_enable_probe_ops = {
1989 .func = event_enable_probe,
1990 .print = event_enable_print,
1991 .init = event_enable_init,
1992 .free = event_enable_free,
1993 };
1994
1995 static struct ftrace_probe_ops event_enable_count_probe_ops = {
1996 .func = event_enable_count_probe,
1997 .print = event_enable_print,
1998 .init = event_enable_init,
1999 .free = event_enable_free,
2000 };
2001
2002 static struct ftrace_probe_ops event_disable_probe_ops = {
2003 .func = event_enable_probe,
2004 .print = event_enable_print,
2005 .init = event_enable_init,
2006 .free = event_enable_free,
2007 };
2008
2009 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2010 .func = event_enable_count_probe,
2011 .print = event_enable_print,
2012 .init = event_enable_init,
2013 .free = event_enable_free,
2014 };
2015
2016 static int
2017 event_enable_func(struct ftrace_hash *hash,
2018 char *glob, char *cmd, char *param, int enabled)
2019 {
2020 struct trace_array *tr = top_trace_array();
2021 struct ftrace_event_file *file;
2022 struct ftrace_probe_ops *ops;
2023 struct event_probe_data *data;
2024 const char *system;
2025 const char *event;
2026 char *number;
2027 bool enable;
2028 int ret;
2029
2030 /* hash funcs only work with set_ftrace_filter */
2031 if (!enabled || !param)
2032 return -EINVAL;
2033
2034 system = strsep(&param, ":");
2035 if (!param)
2036 return -EINVAL;
2037
2038 event = strsep(&param, ":");
2039
2040 mutex_lock(&event_mutex);
2041
2042 ret = -EINVAL;
2043 file = find_event_file(tr, system, event);
2044 if (!file)
2045 goto out;
2046
2047 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2048
2049 if (enable)
2050 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2051 else
2052 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2053
2054 if (glob[0] == '!') {
2055 unregister_ftrace_function_probe_func(glob+1, ops);
2056 ret = 0;
2057 goto out;
2058 }
2059
2060 ret = -ENOMEM;
2061 data = kzalloc(sizeof(*data), GFP_KERNEL);
2062 if (!data)
2063 goto out;
2064
2065 data->enable = enable;
2066 data->count = -1;
2067 data->file = file;
2068
2069 if (!param)
2070 goto out_reg;
2071
2072 number = strsep(&param, ":");
2073
2074 ret = -EINVAL;
2075 if (!strlen(number))
2076 goto out_free;
2077
2078 /*
2079 * We use the callback data field (which is a pointer)
2080 * as our counter.
2081 */
2082 ret = kstrtoul(number, 0, &data->count);
2083 if (ret)
2084 goto out_free;
2085
2086 out_reg:
2087 /* Don't let event modules unload while probe registered */
2088 ret = try_module_get(file->event_call->mod);
2089 if (!ret) {
2090 ret = -EBUSY;
2091 goto out_free;
2092 }
2093
2094 ret = __ftrace_event_enable_disable(file, 1, 1);
2095 if (ret < 0)
2096 goto out_put;
2097 ret = register_ftrace_function_probe(glob, ops, data);
2098 /*
2099 * The above returns on success the # of functions enabled,
2100 * but if it didn't find any functions it returns zero.
2101 * Consider no functions a failure too.
2102 */
2103 if (!ret) {
2104 ret = -ENOENT;
2105 goto out_disable;
2106 } else if (ret < 0)
2107 goto out_disable;
2108 /* Just return zero, not the number of enabled functions */
2109 ret = 0;
2110 out:
2111 mutex_unlock(&event_mutex);
2112 return ret;
2113
2114 out_disable:
2115 __ftrace_event_enable_disable(file, 0, 1);
2116 out_put:
2117 module_put(file->event_call->mod);
2118 out_free:
2119 kfree(data);
2120 goto out;
2121 }
2122
2123 static struct ftrace_func_command event_enable_cmd = {
2124 .name = ENABLE_EVENT_STR,
2125 .func = event_enable_func,
2126 };
2127
2128 static struct ftrace_func_command event_disable_cmd = {
2129 .name = DISABLE_EVENT_STR,
2130 .func = event_enable_func,
2131 };
2132
2133 static __init int register_event_cmds(void)
2134 {
2135 int ret;
2136
2137 ret = register_ftrace_command(&event_enable_cmd);
2138 if (WARN_ON(ret < 0))
2139 return ret;
2140 ret = register_ftrace_command(&event_disable_cmd);
2141 if (WARN_ON(ret < 0))
2142 unregister_ftrace_command(&event_enable_cmd);
2143 return ret;
2144 }
2145 #else
2146 static inline int register_event_cmds(void) { return 0; }
2147 #endif /* CONFIG_DYNAMIC_FTRACE */
2148
2149 /*
2150 * The top level array has already had its ftrace_event_file
2151 * descriptors created in order to allow for early events to
2152 * be recorded. This function is called after the debugfs has been
2153 * initialized, and we now have to create the files associated
2154 * to the events.
2155 */
2156 static __init void
2157 __trace_early_add_event_dirs(struct trace_array *tr)
2158 {
2159 struct ftrace_event_file *file;
2160 int ret;
2161
2162
2163 list_for_each_entry(file, &tr->events, list) {
2164 ret = event_create_dir(tr->event_dir, file);
2165 if (ret < 0)
2166 pr_warning("Could not create directory for event %s\n",
2167 file->event_call->name);
2168 }
2169 }
2170
2171 /*
2172 * For early boot up, the top trace array requires to have
2173 * a list of events that can be enabled. This must be done before
2174 * the filesystem is set up in order to allow events to be traced
2175 * early.
2176 */
2177 static __init void
2178 __trace_early_add_events(struct trace_array *tr)
2179 {
2180 struct ftrace_event_call *call;
2181 int ret;
2182
2183 list_for_each_entry(call, &ftrace_events, list) {
2184 /* Early boot up should not have any modules loaded */
2185 if (WARN_ON_ONCE(call->mod))
2186 continue;
2187
2188 ret = __trace_early_add_new_event(call, tr);
2189 if (ret < 0)
2190 pr_warning("Could not create early event %s\n",
2191 call->name);
2192 }
2193 }
2194
2195 /* Remove the event directory structure for a trace directory. */
2196 static void
2197 __trace_remove_event_dirs(struct trace_array *tr)
2198 {
2199 struct ftrace_event_file *file, *next;
2200
2201 list_for_each_entry_safe(file, next, &tr->events, list)
2202 remove_event_file_dir(file);
2203 }
2204
2205 static void __add_event_to_tracers(struct ftrace_event_call *call)
2206 {
2207 struct trace_array *tr;
2208
2209 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2210 __trace_add_new_event(call, tr);
2211 }
2212
2213 extern struct ftrace_event_call *__start_ftrace_events[];
2214 extern struct ftrace_event_call *__stop_ftrace_events[];
2215
2216 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2217
2218 static __init int setup_trace_event(char *str)
2219 {
2220 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2221 ring_buffer_expanded = true;
2222 tracing_selftest_disabled = true;
2223
2224 return 1;
2225 }
2226 __setup("trace_event=", setup_trace_event);
2227
2228 /* Expects to have event_mutex held when called */
2229 static int
2230 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2231 {
2232 struct dentry *d_events;
2233 struct dentry *entry;
2234
2235 entry = debugfs_create_file("set_event", 0644, parent,
2236 tr, &ftrace_set_event_fops);
2237 if (!entry) {
2238 pr_warning("Could not create debugfs 'set_event' entry\n");
2239 return -ENOMEM;
2240 }
2241
2242 d_events = debugfs_create_dir("events", parent);
2243 if (!d_events) {
2244 pr_warning("Could not create debugfs 'events' directory\n");
2245 return -ENOMEM;
2246 }
2247
2248 /* ring buffer internal formats */
2249 trace_create_file("header_page", 0444, d_events,
2250 ring_buffer_print_page_header,
2251 &ftrace_show_header_fops);
2252
2253 trace_create_file("header_event", 0444, d_events,
2254 ring_buffer_print_entry_header,
2255 &ftrace_show_header_fops);
2256
2257 trace_create_file("enable", 0644, d_events,
2258 tr, &ftrace_tr_enable_fops);
2259
2260 tr->event_dir = d_events;
2261
2262 return 0;
2263 }
2264
2265 /**
2266 * event_trace_add_tracer - add a instance of a trace_array to events
2267 * @parent: The parent dentry to place the files/directories for events in
2268 * @tr: The trace array associated with these events
2269 *
2270 * When a new instance is created, it needs to set up its events
2271 * directory, as well as other files associated with events. It also
2272 * creates the event hierachry in the @parent/events directory.
2273 *
2274 * Returns 0 on success.
2275 */
2276 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2277 {
2278 int ret;
2279
2280 mutex_lock(&event_mutex);
2281
2282 ret = create_event_toplevel_files(parent, tr);
2283 if (ret)
2284 goto out_unlock;
2285
2286 down_write(&trace_event_sem);
2287 __trace_add_event_dirs(tr);
2288 up_write(&trace_event_sem);
2289
2290 out_unlock:
2291 mutex_unlock(&event_mutex);
2292
2293 return ret;
2294 }
2295
2296 /*
2297 * The top trace array already had its file descriptors created.
2298 * Now the files themselves need to be created.
2299 */
2300 static __init int
2301 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2302 {
2303 int ret;
2304
2305 mutex_lock(&event_mutex);
2306
2307 ret = create_event_toplevel_files(parent, tr);
2308 if (ret)
2309 goto out_unlock;
2310
2311 down_write(&trace_event_sem);
2312 __trace_early_add_event_dirs(tr);
2313 up_write(&trace_event_sem);
2314
2315 out_unlock:
2316 mutex_unlock(&event_mutex);
2317
2318 return ret;
2319 }
2320
2321 int event_trace_del_tracer(struct trace_array *tr)
2322 {
2323 mutex_lock(&event_mutex);
2324
2325 /* Disable any event triggers and associated soft-disabled events */
2326 clear_event_triggers(tr);
2327
2328 /* Disable any running events */
2329 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
2330
2331 /* Access to events are within rcu_read_lock_sched() */
2332 synchronize_sched();
2333
2334 down_write(&trace_event_sem);
2335 __trace_remove_event_dirs(tr);
2336 debugfs_remove_recursive(tr->event_dir);
2337 up_write(&trace_event_sem);
2338
2339 tr->event_dir = NULL;
2340
2341 mutex_unlock(&event_mutex);
2342
2343 return 0;
2344 }
2345
2346 static __init int event_trace_memsetup(void)
2347 {
2348 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
2349 file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC);
2350 return 0;
2351 }
2352
2353 static __init int event_trace_enable(void)
2354 {
2355 struct trace_array *tr = top_trace_array();
2356 struct ftrace_event_call **iter, *call;
2357 char *buf = bootup_event_buf;
2358 char *token;
2359 int ret;
2360
2361 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
2362
2363 call = *iter;
2364 ret = event_init(call);
2365 if (!ret)
2366 list_add(&call->list, &ftrace_events);
2367 }
2368
2369 /*
2370 * We need the top trace array to have a working set of trace
2371 * points at early init, before the debug files and directories
2372 * are created. Create the file entries now, and attach them
2373 * to the actual file dentries later.
2374 */
2375 __trace_early_add_events(tr);
2376
2377 while (true) {
2378 token = strsep(&buf, ",");
2379
2380 if (!token)
2381 break;
2382 if (!*token)
2383 continue;
2384
2385 ret = ftrace_set_clr_event(tr, token, 1);
2386 if (ret)
2387 pr_warn("Failed to enable trace event: %s\n", token);
2388 }
2389
2390 trace_printk_start_comm();
2391
2392 register_event_cmds();
2393
2394 register_trigger_cmds();
2395
2396 return 0;
2397 }
2398
2399 static __init int event_trace_init(void)
2400 {
2401 struct trace_array *tr;
2402 struct dentry *d_tracer;
2403 struct dentry *entry;
2404 int ret;
2405
2406 tr = top_trace_array();
2407
2408 d_tracer = tracing_init_dentry();
2409 if (!d_tracer)
2410 return 0;
2411
2412 entry = debugfs_create_file("available_events", 0444, d_tracer,
2413 tr, &ftrace_avail_fops);
2414 if (!entry)
2415 pr_warning("Could not create debugfs "
2416 "'available_events' entry\n");
2417
2418 if (trace_define_common_fields())
2419 pr_warning("tracing: Failed to allocate common fields");
2420
2421 ret = early_event_add_tracer(d_tracer, tr);
2422 if (ret)
2423 return ret;
2424
2425 #ifdef CONFIG_MODULES
2426 ret = register_module_notifier(&trace_module_nb);
2427 if (ret)
2428 pr_warning("Failed to register trace events module notifier\n");
2429 #endif
2430 return 0;
2431 }
2432 early_initcall(event_trace_memsetup);
2433 core_initcall(event_trace_enable);
2434 fs_initcall(event_trace_init);
2435
2436 #ifdef CONFIG_FTRACE_STARTUP_TEST
2437
2438 static DEFINE_SPINLOCK(test_spinlock);
2439 static DEFINE_SPINLOCK(test_spinlock_irq);
2440 static DEFINE_MUTEX(test_mutex);
2441
2442 static __init void test_work(struct work_struct *dummy)
2443 {
2444 spin_lock(&test_spinlock);
2445 spin_lock_irq(&test_spinlock_irq);
2446 udelay(1);
2447 spin_unlock_irq(&test_spinlock_irq);
2448 spin_unlock(&test_spinlock);
2449
2450 mutex_lock(&test_mutex);
2451 msleep(1);
2452 mutex_unlock(&test_mutex);
2453 }
2454
2455 static __init int event_test_thread(void *unused)
2456 {
2457 void *test_malloc;
2458
2459 test_malloc = kmalloc(1234, GFP_KERNEL);
2460 if (!test_malloc)
2461 pr_info("failed to kmalloc\n");
2462
2463 schedule_on_each_cpu(test_work);
2464
2465 kfree(test_malloc);
2466
2467 set_current_state(TASK_INTERRUPTIBLE);
2468 while (!kthread_should_stop())
2469 schedule();
2470
2471 return 0;
2472 }
2473
2474 /*
2475 * Do various things that may trigger events.
2476 */
2477 static __init void event_test_stuff(void)
2478 {
2479 struct task_struct *test_thread;
2480
2481 test_thread = kthread_run(event_test_thread, NULL, "test-events");
2482 msleep(1);
2483 kthread_stop(test_thread);
2484 }
2485
2486 /*
2487 * For every trace event defined, we will test each trace point separately,
2488 * and then by groups, and finally all trace points.
2489 */
2490 static __init void event_trace_self_tests(void)
2491 {
2492 struct ftrace_subsystem_dir *dir;
2493 struct ftrace_event_file *file;
2494 struct ftrace_event_call *call;
2495 struct event_subsystem *system;
2496 struct trace_array *tr;
2497 int ret;
2498
2499 tr = top_trace_array();
2500
2501 pr_info("Running tests on trace events:\n");
2502
2503 list_for_each_entry(file, &tr->events, list) {
2504
2505 call = file->event_call;
2506
2507 /* Only test those that have a probe */
2508 if (!call->class || !call->class->probe)
2509 continue;
2510
2511 /*
2512 * Testing syscall events here is pretty useless, but
2513 * we still do it if configured. But this is time consuming.
2514 * What we really need is a user thread to perform the
2515 * syscalls as we test.
2516 */
2517 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
2518 if (call->class->system &&
2519 strcmp(call->class->system, "syscalls") == 0)
2520 continue;
2521 #endif
2522
2523 pr_info("Testing event %s: ", call->name);
2524
2525 /*
2526 * If an event is already enabled, someone is using
2527 * it and the self test should not be on.
2528 */
2529 if (file->flags & FTRACE_EVENT_FL_ENABLED) {
2530 pr_warning("Enabled event during self test!\n");
2531 WARN_ON_ONCE(1);
2532 continue;
2533 }
2534
2535 ftrace_event_enable_disable(file, 1);
2536 event_test_stuff();
2537 ftrace_event_enable_disable(file, 0);
2538
2539 pr_cont("OK\n");
2540 }
2541
2542 /* Now test at the sub system level */
2543
2544 pr_info("Running tests on trace event systems:\n");
2545
2546 list_for_each_entry(dir, &tr->systems, list) {
2547
2548 system = dir->subsystem;
2549
2550 /* the ftrace system is special, skip it */
2551 if (strcmp(system->name, "ftrace") == 0)
2552 continue;
2553
2554 pr_info("Testing event system %s: ", system->name);
2555
2556 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
2557 if (WARN_ON_ONCE(ret)) {
2558 pr_warning("error enabling system %s\n",
2559 system->name);
2560 continue;
2561 }
2562
2563 event_test_stuff();
2564
2565 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
2566 if (WARN_ON_ONCE(ret)) {
2567 pr_warning("error disabling system %s\n",
2568 system->name);
2569 continue;
2570 }
2571
2572 pr_cont("OK\n");
2573 }
2574
2575 /* Test with all events enabled */
2576
2577 pr_info("Running tests on all trace events:\n");
2578 pr_info("Testing all events: ");
2579
2580 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
2581 if (WARN_ON_ONCE(ret)) {
2582 pr_warning("error enabling all events\n");
2583 return;
2584 }
2585
2586 event_test_stuff();
2587
2588 /* reset sysname */
2589 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
2590 if (WARN_ON_ONCE(ret)) {
2591 pr_warning("error disabling all events\n");
2592 return;
2593 }
2594
2595 pr_cont("OK\n");
2596 }
2597
2598 #ifdef CONFIG_FUNCTION_TRACER
2599
2600 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
2601
2602 static void
2603 function_test_events_call(unsigned long ip, unsigned long parent_ip,
2604 struct ftrace_ops *op, struct pt_regs *pt_regs)
2605 {
2606 struct ring_buffer_event *event;
2607 struct ring_buffer *buffer;
2608 struct ftrace_entry *entry;
2609 unsigned long flags;
2610 long disabled;
2611 int cpu;
2612 int pc;
2613
2614 pc = preempt_count();
2615 preempt_disable_notrace();
2616 cpu = raw_smp_processor_id();
2617 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
2618
2619 if (disabled != 1)
2620 goto out;
2621
2622 local_save_flags(flags);
2623
2624 event = trace_current_buffer_lock_reserve(&buffer,
2625 TRACE_FN, sizeof(*entry),
2626 flags, pc);
2627 if (!event)
2628 goto out;
2629 entry = ring_buffer_event_data(event);
2630 entry->ip = ip;
2631 entry->parent_ip = parent_ip;
2632
2633 trace_buffer_unlock_commit(buffer, event, flags, pc);
2634
2635 out:
2636 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
2637 preempt_enable_notrace();
2638 }
2639
2640 static struct ftrace_ops trace_ops __initdata =
2641 {
2642 .func = function_test_events_call,
2643 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
2644 };
2645
2646 static __init void event_trace_self_test_with_function(void)
2647 {
2648 int ret;
2649 ret = register_ftrace_function(&trace_ops);
2650 if (WARN_ON(ret < 0)) {
2651 pr_info("Failed to enable function tracer for event tests\n");
2652 return;
2653 }
2654 pr_info("Running tests again, along with the function tracer\n");
2655 event_trace_self_tests();
2656 unregister_ftrace_function(&trace_ops);
2657 }
2658 #else
2659 static __init void event_trace_self_test_with_function(void)
2660 {
2661 }
2662 #endif
2663
2664 static __init int event_trace_self_tests_init(void)
2665 {
2666 if (!tracing_selftest_disabled) {
2667 event_trace_self_tests();
2668 event_trace_self_test_with_function();
2669 }
2670
2671 return 0;
2672 }
2673
2674 late_initcall(event_trace_self_tests_init);
2675
2676 #endif
Linux with added FPC-III support