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Merge tag 'v3.10.61' into update
[GitHub/mt8127/android_kernel_alcatel_ttab.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 #include <linux/mtk_ftrace.h>
26
27 #undef TRACE_SYSTEM
28 #define TRACE_SYSTEM "TRACE_SYSTEM"
29
30 DEFINE_MUTEX(event_mutex);
31
32 LIST_HEAD(ftrace_events);
33 static LIST_HEAD(ftrace_common_fields);
34
35 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
36
37 static struct kmem_cache *field_cachep;
38 static struct kmem_cache *file_cachep;
39
40 #define SYSTEM_FL_FREE_NAME (1 << 31)
41
42 static inline int system_refcount(struct event_subsystem *system)
43 {
44 return system->ref_count & ~SYSTEM_FL_FREE_NAME;
45 }
46
47 static int system_refcount_inc(struct event_subsystem *system)
48 {
49 return (system->ref_count++) & ~SYSTEM_FL_FREE_NAME;
50 }
51
52 static int system_refcount_dec(struct event_subsystem *system)
53 {
54 return (--system->ref_count) & ~SYSTEM_FL_FREE_NAME;
55 }
56
57 /* Double loops, do not use break, only goto's work */
58 #define do_for_each_event_file(tr, file) \
59 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
60 list_for_each_entry(file, &tr->events, list)
61
62 #define do_for_each_event_file_safe(tr, file) \
63 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
64 struct ftrace_event_file *___n; \
65 list_for_each_entry_safe(file, ___n, &tr->events, list)
66
67 #define while_for_each_event_file() \
68 }
69
70 static struct list_head *
71 trace_get_fields(struct ftrace_event_call *event_call)
72 {
73 if (!event_call->class->get_fields)
74 return &event_call->class->fields;
75 return event_call->class->get_fields(event_call);
76 }
77
78 static struct ftrace_event_field *
79 __find_event_field(struct list_head *head, char *name)
80 {
81 struct ftrace_event_field *field;
82
83 list_for_each_entry(field, head, link) {
84 if (!strcmp(field->name, name))
85 return field;
86 }
87
88 return NULL;
89 }
90
91 struct ftrace_event_field *
92 trace_find_event_field(struct ftrace_event_call *call, char *name)
93 {
94 struct ftrace_event_field *field;
95 struct list_head *head;
96
97 field = __find_event_field(&ftrace_common_fields, name);
98 if (field)
99 return field;
100
101 head = trace_get_fields(call);
102 return __find_event_field(head, name);
103 }
104
105 static int __trace_define_field(struct list_head *head, const char *type,
106 const char *name, int offset, int size,
107 int is_signed, int filter_type)
108 {
109 struct ftrace_event_field *field;
110
111 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
112 if (!field)
113 return -ENOMEM;
114
115 field->name = name;
116 field->type = type;
117
118 if (filter_type == FILTER_OTHER)
119 field->filter_type = filter_assign_type(type);
120 else
121 field->filter_type = filter_type;
122
123 field->offset = offset;
124 field->size = size;
125 field->is_signed = is_signed;
126
127 list_add(&field->link, head);
128
129 return 0;
130 }
131
132 int trace_define_field(struct ftrace_event_call *call, const char *type,
133 const char *name, int offset, int size, int is_signed,
134 int filter_type)
135 {
136 struct list_head *head;
137
138 if (WARN_ON(!call->class))
139 return 0;
140
141 head = trace_get_fields(call);
142 return __trace_define_field(head, type, name, offset, size,
143 is_signed, filter_type);
144 }
145 EXPORT_SYMBOL_GPL(trace_define_field);
146
147 #define __common_field(type, item) \
148 ret = __trace_define_field(&ftrace_common_fields, #type, \
149 "common_" #item, \
150 offsetof(typeof(ent), item), \
151 sizeof(ent.item), \
152 is_signed_type(type), FILTER_OTHER); \
153 if (ret) \
154 return ret;
155
156 static int trace_define_common_fields(void)
157 {
158 int ret;
159 struct trace_entry ent;
160
161 __common_field(unsigned short, type);
162 __common_field(unsigned char, flags);
163 __common_field(unsigned char, preempt_count);
164 __common_field(int, pid);
165
166 return ret;
167 }
168
169 static void trace_destroy_fields(struct ftrace_event_call *call)
170 {
171 struct ftrace_event_field *field, *next;
172 struct list_head *head;
173
174 head = trace_get_fields(call);
175 list_for_each_entry_safe(field, next, head, link) {
176 list_del(&field->link);
177 kmem_cache_free(field_cachep, field);
178 }
179 }
180
181 int trace_event_raw_init(struct ftrace_event_call *call)
182 {
183 int id;
184
185 id = register_ftrace_event(&call->event);
186 if (!id)
187 return -ENODEV;
188
189 return 0;
190 }
191 EXPORT_SYMBOL_GPL(trace_event_raw_init);
192
193 int ftrace_event_reg(struct ftrace_event_call *call,
194 enum trace_reg type, void *data)
195 {
196 struct ftrace_event_file *file = data;
197
198 switch (type) {
199 case TRACE_REG_REGISTER:
200 return tracepoint_probe_register(call->name,
201 call->class->probe,
202 file);
203 case TRACE_REG_UNREGISTER:
204 tracepoint_probe_unregister(call->name,
205 call->class->probe,
206 file);
207 return 0;
208
209 #ifdef CONFIG_PERF_EVENTS
210 case TRACE_REG_PERF_REGISTER:
211 return tracepoint_probe_register(call->name,
212 call->class->perf_probe,
213 call);
214 case TRACE_REG_PERF_UNREGISTER:
215 tracepoint_probe_unregister(call->name,
216 call->class->perf_probe,
217 call);
218 return 0;
219 case TRACE_REG_PERF_OPEN:
220 case TRACE_REG_PERF_CLOSE:
221 case TRACE_REG_PERF_ADD:
222 case TRACE_REG_PERF_DEL:
223 return 0;
224 #endif
225 }
226 return 0;
227 }
228 EXPORT_SYMBOL_GPL(ftrace_event_reg);
229
230 void trace_event_enable_cmd_record(bool enable)
231 {
232 struct ftrace_event_file *file;
233 struct trace_array *tr;
234
235 mutex_lock(&event_mutex);
236 do_for_each_event_file(tr, file) {
237
238 if (!(file->flags & FTRACE_EVENT_FL_ENABLED))
239 continue;
240
241 if (enable) {
242 tracing_start_cmdline_record();
243 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
244 } else {
245 tracing_stop_cmdline_record();
246 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
247 }
248 } while_for_each_event_file();
249 mutex_unlock(&event_mutex);
250 }
251
252 static int __ftrace_event_enable_disable(struct ftrace_event_file *file,
253 int enable, int soft_disable)
254 {
255 struct ftrace_event_call *call = file->event_call;
256 int ret = 0;
257 int disable;
258
259 if(call->name && ((file->flags & FTRACE_EVENT_FL_ENABLED) ^ enable))
260 printk(KERN_INFO "[ftrace]event '%s' is %s\n", call->name, enable?"enabled":"disabled");
261
262 switch (enable) {
263 case 0:
264 /*
265 * When soft_disable is set and enable is cleared, the sm_ref
266 * reference counter is decremented. If it reaches 0, we want
267 * to clear the SOFT_DISABLED flag but leave the event in the
268 * state that it was. That is, if the event was enabled and
269 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
270 * is set we do not want the event to be enabled before we
271 * clear the bit.
272 *
273 * When soft_disable is not set but the SOFT_MODE flag is,
274 * we do nothing. Do not disable the tracepoint, otherwise
275 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
276 */
277 if (soft_disable) {
278 if (atomic_dec_return(&file->sm_ref) > 0)
279 break;
280 disable = file->flags & FTRACE_EVENT_FL_SOFT_DISABLED;
281 clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
282 } else
283 disable = !(file->flags & FTRACE_EVENT_FL_SOFT_MODE);
284
285 if (disable && (file->flags & FTRACE_EVENT_FL_ENABLED)) {
286 clear_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
287 if (file->flags & FTRACE_EVENT_FL_RECORDED_CMD) {
288 tracing_stop_cmdline_record();
289 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
290 }
291 call->class->reg(call, TRACE_REG_UNREGISTER, file);
292 }
293 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT */
294 if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
295 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
296 break;
297 case 1:
298 /*
299 * When soft_disable is set and enable is set, we want to
300 * register the tracepoint for the event, but leave the event
301 * as is. That means, if the event was already enabled, we do
302 * nothing (but set SOFT_MODE). If the event is disabled, we
303 * set SOFT_DISABLED before enabling the event tracepoint, so
304 * it still seems to be disabled.
305 */
306 if (!soft_disable)
307 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
308 else {
309 if (atomic_inc_return(&file->sm_ref) > 1)
310 break;
311 set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
312 }
313
314 if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) {
315
316 /* Keep the event disabled, when going to SOFT_MODE. */
317 if (soft_disable)
318 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
319
320 if (trace_flags & TRACE_ITER_RECORD_CMD) {
321 tracing_start_cmdline_record();
322 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
323 }
324 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
325 if (ret) {
326 tracing_stop_cmdline_record();
327 pr_info("event trace: Could not enable event "
328 "%s\n", call->name);
329 break;
330 }
331 set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
332
333 /* WAS_ENABLED gets set but never cleared. */
334 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
335 }
336 break;
337 }
338
339 return ret;
340 }
341
342 static int ftrace_event_enable_disable(struct ftrace_event_file *file,
343 int enable)
344 {
345 return __ftrace_event_enable_disable(file, enable, 0);
346 }
347
348 static void ftrace_clear_events(struct trace_array *tr)
349 {
350 struct ftrace_event_file *file;
351
352 mutex_lock(&event_mutex);
353 list_for_each_entry(file, &tr->events, list) {
354 ftrace_event_enable_disable(file, 0);
355 }
356 mutex_unlock(&event_mutex);
357 }
358
359 static void __put_system(struct event_subsystem *system)
360 {
361 struct event_filter *filter = system->filter;
362
363 WARN_ON_ONCE(system_refcount(system) == 0);
364 if (system_refcount_dec(system))
365 return;
366
367 list_del(&system->list);
368
369 if (filter) {
370 kfree(filter->filter_string);
371 kfree(filter);
372 }
373 if (system->ref_count & SYSTEM_FL_FREE_NAME)
374 kfree(system->name);
375 kfree(system);
376 }
377
378 static void __get_system(struct event_subsystem *system)
379 {
380 WARN_ON_ONCE(system_refcount(system) == 0);
381 system_refcount_inc(system);
382 }
383
384 static void __get_system_dir(struct ftrace_subsystem_dir *dir)
385 {
386 WARN_ON_ONCE(dir->ref_count == 0);
387 dir->ref_count++;
388 __get_system(dir->subsystem);
389 }
390
391 static void __put_system_dir(struct ftrace_subsystem_dir *dir)
392 {
393 WARN_ON_ONCE(dir->ref_count == 0);
394 /* If the subsystem is about to be freed, the dir must be too */
395 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
396
397 __put_system(dir->subsystem);
398 if (!--dir->ref_count)
399 kfree(dir);
400 }
401
402 static void put_system(struct ftrace_subsystem_dir *dir)
403 {
404 mutex_lock(&event_mutex);
405 __put_system_dir(dir);
406 mutex_unlock(&event_mutex);
407 }
408
409 static void remove_subsystem(struct ftrace_subsystem_dir *dir)
410 {
411 if (!dir)
412 return;
413
414 if (!--dir->nr_events) {
415 debugfs_remove_recursive(dir->entry);
416 list_del(&dir->list);
417 __put_system_dir(dir);
418 }
419 }
420
421 static void *event_file_data(struct file *filp)
422 {
423 return ACCESS_ONCE(file_inode(filp)->i_private);
424 }
425
426 static void remove_event_file_dir(struct ftrace_event_file *file)
427 {
428 struct dentry *dir = file->dir;
429 struct dentry *child;
430
431 if (dir) {
432 spin_lock(&dir->d_lock); /* probably unneeded */
433 list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
434 if (child->d_inode) /* probably unneeded */
435 child->d_inode->i_private = NULL;
436 }
437 spin_unlock(&dir->d_lock);
438
439 debugfs_remove_recursive(dir);
440 }
441
442 list_del(&file->list);
443 remove_subsystem(file->system);
444 kmem_cache_free(file_cachep, file);
445 }
446
447 /*
448 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
449 */
450 static int
451 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
452 const char *sub, const char *event, int set)
453 {
454 struct ftrace_event_file *file;
455 struct ftrace_event_call *call;
456 int ret = -EINVAL;
457
458 list_for_each_entry(file, &tr->events, list) {
459
460 call = file->event_call;
461
462 if (!call->name || !call->class || !call->class->reg)
463 continue;
464
465 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
466 continue;
467
468 if (match &&
469 strcmp(match, call->name) != 0 &&
470 strcmp(match, call->class->system) != 0)
471 continue;
472
473 if (sub && strcmp(sub, call->class->system) != 0)
474 continue;
475
476 if (event && strcmp(event, call->name) != 0)
477 continue;
478
479 ftrace_event_enable_disable(file, set);
480
481 ret = 0;
482 }
483
484 return ret;
485 }
486
487 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
488 const char *sub, const char *event, int set)
489 {
490 int ret;
491
492 mutex_lock(&event_mutex);
493 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
494 mutex_unlock(&event_mutex);
495
496 return ret;
497 }
498
499 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
500 {
501 char *event = NULL, *sub = NULL, *match;
502
503 /*
504 * The buf format can be <subsystem>:<event-name>
505 * *:<event-name> means any event by that name.
506 * :<event-name> is the same.
507 *
508 * <subsystem>:* means all events in that subsystem
509 * <subsystem>: means the same.
510 *
511 * <name> (no ':') means all events in a subsystem with
512 * the name <name> or any event that matches <name>
513 */
514
515 match = strsep(&buf, ":");
516 if (buf) {
517 sub = match;
518 event = buf;
519 match = NULL;
520
521 if (!strlen(sub) || strcmp(sub, "*") == 0)
522 sub = NULL;
523 if (!strlen(event) || strcmp(event, "*") == 0)
524 event = NULL;
525 }
526
527 return __ftrace_set_clr_event(tr, match, sub, event, set);
528 }
529
530 /**
531 * trace_set_clr_event - enable or disable an event
532 * @system: system name to match (NULL for any system)
533 * @event: event name to match (NULL for all events, within system)
534 * @set: 1 to enable, 0 to disable
535 *
536 * This is a way for other parts of the kernel to enable or disable
537 * event recording.
538 *
539 * Returns 0 on success, -EINVAL if the parameters do not match any
540 * registered events.
541 */
542 int trace_set_clr_event(const char *system, const char *event, int set)
543 {
544 struct trace_array *tr = top_trace_array();
545
546 return __ftrace_set_clr_event(tr, NULL, system, event, set);
547 }
548 EXPORT_SYMBOL_GPL(trace_set_clr_event);
549
550 /* 128 should be much more than enough */
551 #define EVENT_BUF_SIZE 127
552
553 static ssize_t
554 ftrace_event_write(struct file *file, const char __user *ubuf,
555 size_t cnt, loff_t *ppos)
556 {
557 struct trace_parser parser;
558 struct seq_file *m = file->private_data;
559 struct trace_array *tr = m->private;
560 ssize_t read, ret;
561
562 if (!cnt)
563 return 0;
564
565 ret = tracing_update_buffers();
566 if (ret < 0)
567 return ret;
568
569 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
570 return -ENOMEM;
571
572 read = trace_get_user(&parser, ubuf, cnt, ppos);
573
574 if (read >= 0 && trace_parser_loaded((&parser))) {
575 int set = 1;
576
577 if (*parser.buffer == '!')
578 set = 0;
579
580 parser.buffer[parser.idx] = 0;
581
582 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
583 if (ret)
584 goto out_put;
585 }
586
587 ret = read;
588
589 out_put:
590 trace_parser_put(&parser);
591
592 return ret;
593 }
594
595 static void *
596 t_next(struct seq_file *m, void *v, loff_t *pos)
597 {
598 struct ftrace_event_file *file = v;
599 struct ftrace_event_call *call;
600 struct trace_array *tr = m->private;
601
602 (*pos)++;
603
604 list_for_each_entry_continue(file, &tr->events, list) {
605 call = file->event_call;
606 /*
607 * The ftrace subsystem is for showing formats only.
608 * They can not be enabled or disabled via the event files.
609 */
610 if (call->class && call->class->reg)
611 return file;
612 }
613
614 return NULL;
615 }
616
617 static void *t_start(struct seq_file *m, loff_t *pos)
618 {
619 struct ftrace_event_file *file;
620 struct trace_array *tr = m->private;
621 loff_t l;
622
623 mutex_lock(&event_mutex);
624
625 file = list_entry(&tr->events, struct ftrace_event_file, list);
626 for (l = 0; l <= *pos; ) {
627 file = t_next(m, file, &l);
628 if (!file)
629 break;
630 }
631 return file;
632 }
633
634 static void *
635 s_next(struct seq_file *m, void *v, loff_t *pos)
636 {
637 struct ftrace_event_file *file = v;
638 struct trace_array *tr = m->private;
639
640 (*pos)++;
641
642 list_for_each_entry_continue(file, &tr->events, list) {
643 if (file->flags & FTRACE_EVENT_FL_ENABLED)
644 return file;
645 }
646
647 return NULL;
648 }
649
650 static void *s_start(struct seq_file *m, loff_t *pos)
651 {
652 struct ftrace_event_file *file;
653 struct trace_array *tr = m->private;
654 loff_t l;
655
656 mutex_lock(&event_mutex);
657
658 file = list_entry(&tr->events, struct ftrace_event_file, list);
659 for (l = 0; l <= *pos; ) {
660 file = s_next(m, file, &l);
661 if (!file)
662 break;
663 }
664 return file;
665 }
666
667 static int t_show(struct seq_file *m, void *v)
668 {
669 struct ftrace_event_file *file = v;
670 struct ftrace_event_call *call = file->event_call;
671
672 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
673 seq_printf(m, "%s:", call->class->system);
674 seq_printf(m, "%s\n", call->name);
675
676 return 0;
677 }
678
679 static void t_stop(struct seq_file *m, void *p)
680 {
681 mutex_unlock(&event_mutex);
682 }
683
684 static ssize_t
685 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
686 loff_t *ppos)
687 {
688 struct ftrace_event_file *file;
689 unsigned long flags;
690 char *buf;
691
692 mutex_lock(&event_mutex);
693 file = event_file_data(filp);
694 if (likely(file))
695 flags = file->flags;
696 mutex_unlock(&event_mutex);
697
698 if (!file)
699 return -ENODEV;
700
701 if (flags & FTRACE_EVENT_FL_ENABLED) {
702 if (flags & FTRACE_EVENT_FL_SOFT_DISABLED)
703 buf = "0*\n";
704 else if (flags & FTRACE_EVENT_FL_SOFT_MODE)
705 buf = "1*\n";
706 else
707 buf = "1\n";
708 } else
709 buf = "0\n";
710
711 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
712 }
713
714 static ssize_t
715 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
716 loff_t *ppos)
717 {
718 struct ftrace_event_file *file;
719 unsigned long val;
720 int ret;
721
722 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
723 if (ret)
724 return ret;
725
726 ret = tracing_update_buffers();
727 if (ret < 0)
728 return ret;
729
730 switch (val) {
731 case 0:
732 case 1:
733 ret = -ENODEV;
734 mutex_lock(&event_mutex);
735 file = event_file_data(filp);
736 if (likely(file))
737 ret = ftrace_event_enable_disable(file, val);
738 mutex_unlock(&event_mutex);
739 break;
740
741 default:
742 return -EINVAL;
743 }
744
745 *ppos += cnt;
746
747 return ret ? ret : cnt;
748 }
749
750 static ssize_t
751 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
752 loff_t *ppos)
753 {
754 const char set_to_char[4] = { '?', '0', '1', 'X' };
755 struct ftrace_subsystem_dir *dir = filp->private_data;
756 struct event_subsystem *system = dir->subsystem;
757 struct ftrace_event_call *call;
758 struct ftrace_event_file *file;
759 struct trace_array *tr = dir->tr;
760 char buf[2];
761 int set = 0;
762 int ret;
763
764 mutex_lock(&event_mutex);
765 list_for_each_entry(file, &tr->events, list) {
766 call = file->event_call;
767 if (!call->name || !call->class || !call->class->reg)
768 continue;
769
770 if (system && strcmp(call->class->system, system->name) != 0)
771 continue;
772
773 /*
774 * We need to find out if all the events are set
775 * or if all events or cleared, or if we have
776 * a mixture.
777 */
778 set |= (1 << !!(file->flags & FTRACE_EVENT_FL_ENABLED));
779
780 /*
781 * If we have a mixture, no need to look further.
782 */
783 if (set == 3)
784 break;
785 }
786 mutex_unlock(&event_mutex);
787
788 buf[0] = set_to_char[set];
789 buf[1] = '\n';
790
791 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
792
793 return ret;
794 }
795
796 static ssize_t
797 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
798 loff_t *ppos)
799 {
800 struct ftrace_subsystem_dir *dir = filp->private_data;
801 struct event_subsystem *system = dir->subsystem;
802 const char *name = NULL;
803 unsigned long val;
804 ssize_t ret;
805
806 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
807 if (ret)
808 return ret;
809
810 ret = tracing_update_buffers();
811 if (ret < 0)
812 return ret;
813
814 if (val != 0 && val != 1)
815 return -EINVAL;
816
817 /*
818 * Opening of "enable" adds a ref count to system,
819 * so the name is safe to use.
820 */
821 if (system)
822 name = system->name;
823
824 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
825 if (ret)
826 goto out;
827
828 ret = cnt;
829
830 out:
831 *ppos += cnt;
832
833 return ret;
834 }
835
836 enum {
837 FORMAT_HEADER = 1,
838 FORMAT_FIELD_SEPERATOR = 2,
839 FORMAT_PRINTFMT = 3,
840 };
841
842 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
843 {
844 struct ftrace_event_call *call = event_file_data(m->private);
845 struct ftrace_event_field *field;
846 struct list_head *common_head = &ftrace_common_fields;
847 struct list_head *head = trace_get_fields(call);
848
849 (*pos)++;
850
851 switch ((unsigned long)v) {
852 case FORMAT_HEADER:
853 if (unlikely(list_empty(common_head)))
854 return NULL;
855
856 field = list_entry(common_head->prev,
857 struct ftrace_event_field, link);
858 return field;
859
860 case FORMAT_FIELD_SEPERATOR:
861 if (unlikely(list_empty(head)))
862 return NULL;
863
864 field = list_entry(head->prev, struct ftrace_event_field, link);
865 return field;
866
867 case FORMAT_PRINTFMT:
868 /* all done */
869 return NULL;
870 }
871
872 field = v;
873 if (field->link.prev == common_head)
874 return (void *)FORMAT_FIELD_SEPERATOR;
875 else if (field->link.prev == head)
876 return (void *)FORMAT_PRINTFMT;
877
878 field = list_entry(field->link.prev, struct ftrace_event_field, link);
879
880 return field;
881 }
882
883 static void *f_start(struct seq_file *m, loff_t *pos)
884 {
885 loff_t l = 0;
886 void *p;
887
888 /* ->stop() is called even if ->start() fails */
889 mutex_lock(&event_mutex);
890 if (!event_file_data(m->private))
891 return ERR_PTR(-ENODEV);
892
893 /* Start by showing the header */
894 if (!*pos)
895 return (void *)FORMAT_HEADER;
896
897 p = (void *)FORMAT_HEADER;
898 do {
899 p = f_next(m, p, &l);
900 } while (p && l < *pos);
901
902 return p;
903 }
904
905 static int f_show(struct seq_file *m, void *v)
906 {
907 struct ftrace_event_call *call = event_file_data(m->private);
908 struct ftrace_event_field *field;
909 const char *array_descriptor;
910
911 switch ((unsigned long)v) {
912 case FORMAT_HEADER:
913 seq_printf(m, "name: %s\n", call->name);
914 seq_printf(m, "ID: %d\n", call->event.type);
915 seq_printf(m, "format:\n");
916 return 0;
917
918 case FORMAT_FIELD_SEPERATOR:
919 seq_putc(m, '\n');
920 return 0;
921
922 case FORMAT_PRINTFMT:
923 seq_printf(m, "\nprint fmt: %s\n",
924 call->print_fmt);
925 return 0;
926 }
927
928 field = v;
929
930 /*
931 * Smartly shows the array type(except dynamic array).
932 * Normal:
933 * field:TYPE VAR
934 * If TYPE := TYPE[LEN], it is shown:
935 * field:TYPE VAR[LEN]
936 */
937 array_descriptor = strchr(field->type, '[');
938
939 if (!strncmp(field->type, "__data_loc", 10))
940 array_descriptor = NULL;
941
942 if (!array_descriptor)
943 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
944 field->type, field->name, field->offset,
945 field->size, !!field->is_signed);
946 else
947 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
948 (int)(array_descriptor - field->type),
949 field->type, field->name,
950 array_descriptor, field->offset,
951 field->size, !!field->is_signed);
952
953 return 0;
954 }
955
956 static void f_stop(struct seq_file *m, void *p)
957 {
958 mutex_unlock(&event_mutex);
959 }
960
961 static const struct seq_operations trace_format_seq_ops = {
962 .start = f_start,
963 .next = f_next,
964 .stop = f_stop,
965 .show = f_show,
966 };
967
968 static int trace_format_open(struct inode *inode, struct file *file)
969 {
970 struct seq_file *m;
971 int ret;
972
973 ret = seq_open(file, &trace_format_seq_ops);
974 if (ret < 0)
975 return ret;
976
977 m = file->private_data;
978 m->private = file;
979
980 return 0;
981 }
982
983 static ssize_t
984 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
985 {
986 int id = (long)event_file_data(filp);
987 struct trace_seq *s;
988 int r;
989
990 if (*ppos)
991 return 0;
992
993 if (unlikely(!id))
994 return -ENODEV;
995
996 s = kmalloc(sizeof(*s), GFP_KERNEL);
997 if (!s)
998 return -ENOMEM;
999
1000 trace_seq_init(s);
1001 trace_seq_printf(s, "%d\n", id);
1002
1003 r = simple_read_from_buffer(ubuf, cnt, ppos,
1004 s->buffer, s->len);
1005 kfree(s);
1006 return r;
1007 }
1008
1009 static ssize_t
1010 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1011 loff_t *ppos)
1012 {
1013 struct ftrace_event_call *call;
1014 struct trace_seq *s;
1015 int r = -ENODEV;
1016
1017 if (*ppos)
1018 return 0;
1019
1020 s = kmalloc(sizeof(*s), GFP_KERNEL);
1021
1022 if (!s)
1023 return -ENOMEM;
1024
1025 trace_seq_init(s);
1026
1027 mutex_lock(&event_mutex);
1028 call = event_file_data(filp);
1029 if (call)
1030 print_event_filter(call, s);
1031 mutex_unlock(&event_mutex);
1032
1033 if (call)
1034 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1035
1036 kfree(s);
1037
1038 return r;
1039 }
1040
1041 static ssize_t
1042 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1043 loff_t *ppos)
1044 {
1045 struct ftrace_event_call *call;
1046 char *buf;
1047 int err = -ENODEV;
1048
1049 if (cnt >= PAGE_SIZE)
1050 return -EINVAL;
1051
1052 buf = (char *)__get_free_page(GFP_TEMPORARY);
1053 if (!buf)
1054 return -ENOMEM;
1055
1056 if (copy_from_user(buf, ubuf, cnt)) {
1057 free_page((unsigned long) buf);
1058 return -EFAULT;
1059 }
1060 buf[cnt] = '\0';
1061
1062 mutex_lock(&event_mutex);
1063 call = event_file_data(filp);
1064 if (call)
1065 err = apply_event_filter(call, buf);
1066 mutex_unlock(&event_mutex);
1067
1068 free_page((unsigned long) buf);
1069 if (err < 0)
1070 return err;
1071
1072 *ppos += cnt;
1073
1074 return cnt;
1075 }
1076
1077 static LIST_HEAD(event_subsystems);
1078
1079 static int subsystem_open(struct inode *inode, struct file *filp)
1080 {
1081 struct event_subsystem *system = NULL;
1082 struct ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1083 struct trace_array *tr;
1084 int ret;
1085
1086 /* Make sure the system still exists */
1087 mutex_lock(&trace_types_lock);
1088 mutex_lock(&event_mutex);
1089 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1090 list_for_each_entry(dir, &tr->systems, list) {
1091 if (dir == inode->i_private) {
1092 /* Don't open systems with no events */
1093 if (dir->nr_events) {
1094 __get_system_dir(dir);
1095 system = dir->subsystem;
1096 }
1097 goto exit_loop;
1098 }
1099 }
1100 }
1101 exit_loop:
1102 mutex_unlock(&event_mutex);
1103 mutex_unlock(&trace_types_lock);
1104
1105 if (!system)
1106 return -ENODEV;
1107
1108 /* Some versions of gcc think dir can be uninitialized here */
1109 WARN_ON(!dir);
1110
1111 /* Still need to increment the ref count of the system */
1112 if (trace_array_get(tr) < 0) {
1113 put_system(dir);
1114 return -ENODEV;
1115 }
1116
1117 ret = tracing_open_generic(inode, filp);
1118 if (ret < 0) {
1119 trace_array_put(tr);
1120 put_system(dir);
1121 }
1122
1123 return ret;
1124 }
1125
1126 static int system_tr_open(struct inode *inode, struct file *filp)
1127 {
1128 struct ftrace_subsystem_dir *dir;
1129 struct trace_array *tr = inode->i_private;
1130 int ret;
1131
1132 if (trace_array_get(tr) < 0)
1133 return -ENODEV;
1134
1135 /* Make a temporary dir that has no system but points to tr */
1136 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1137 if (!dir) {
1138 trace_array_put(tr);
1139 return -ENOMEM;
1140 }
1141
1142 dir->tr = tr;
1143
1144 ret = tracing_open_generic(inode, filp);
1145 if (ret < 0) {
1146 trace_array_put(tr);
1147 kfree(dir);
1148 }
1149
1150 filp->private_data = dir;
1151
1152 return ret;
1153 }
1154
1155 static int subsystem_release(struct inode *inode, struct file *file)
1156 {
1157 struct ftrace_subsystem_dir *dir = file->private_data;
1158
1159 trace_array_put(dir->tr);
1160
1161 /*
1162 * If dir->subsystem is NULL, then this is a temporary
1163 * descriptor that was made for a trace_array to enable
1164 * all subsystems.
1165 */
1166 if (dir->subsystem)
1167 put_system(dir);
1168 else
1169 kfree(dir);
1170
1171 return 0;
1172 }
1173
1174 static ssize_t
1175 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1176 loff_t *ppos)
1177 {
1178 struct ftrace_subsystem_dir *dir = filp->private_data;
1179 struct event_subsystem *system = dir->subsystem;
1180 struct trace_seq *s;
1181 int r;
1182
1183 if (*ppos)
1184 return 0;
1185
1186 s = kmalloc(sizeof(*s), GFP_KERNEL);
1187 if (!s)
1188 return -ENOMEM;
1189
1190 trace_seq_init(s);
1191
1192 print_subsystem_event_filter(system, s);
1193 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1194
1195 kfree(s);
1196
1197 return r;
1198 }
1199
1200 static ssize_t
1201 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1202 loff_t *ppos)
1203 {
1204 struct ftrace_subsystem_dir *dir = filp->private_data;
1205 char *buf;
1206 int err;
1207
1208 if (cnt >= PAGE_SIZE)
1209 return -EINVAL;
1210
1211 buf = (char *)__get_free_page(GFP_TEMPORARY);
1212 if (!buf)
1213 return -ENOMEM;
1214
1215 if (copy_from_user(buf, ubuf, cnt)) {
1216 free_page((unsigned long) buf);
1217 return -EFAULT;
1218 }
1219 buf[cnt] = '\0';
1220
1221 err = apply_subsystem_event_filter(dir, buf);
1222 free_page((unsigned long) buf);
1223 if (err < 0)
1224 return err;
1225
1226 *ppos += cnt;
1227
1228 return cnt;
1229 }
1230
1231 static ssize_t
1232 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1233 {
1234 int (*func)(struct trace_seq *s) = filp->private_data;
1235 struct trace_seq *s;
1236 int r;
1237
1238 if (*ppos)
1239 return 0;
1240
1241 s = kmalloc(sizeof(*s), GFP_KERNEL);
1242 if (!s)
1243 return -ENOMEM;
1244
1245 trace_seq_init(s);
1246
1247 func(s);
1248 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1249
1250 kfree(s);
1251
1252 return r;
1253 }
1254
1255 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1256 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1257 static int ftrace_event_release(struct inode *inode, struct file *file);
1258
1259 static const struct seq_operations show_event_seq_ops = {
1260 .start = t_start,
1261 .next = t_next,
1262 .show = t_show,
1263 .stop = t_stop,
1264 };
1265
1266 static const struct seq_operations show_set_event_seq_ops = {
1267 .start = s_start,
1268 .next = s_next,
1269 .show = t_show,
1270 .stop = t_stop,
1271 };
1272
1273 static const struct file_operations ftrace_avail_fops = {
1274 .open = ftrace_event_avail_open,
1275 .read = seq_read,
1276 .llseek = seq_lseek,
1277 .release = seq_release,
1278 };
1279
1280 static const struct file_operations ftrace_set_event_fops = {
1281 .open = ftrace_event_set_open,
1282 .read = seq_read,
1283 .write = ftrace_event_write,
1284 .llseek = seq_lseek,
1285 .release = ftrace_event_release,
1286 };
1287
1288 static const struct file_operations ftrace_enable_fops = {
1289 .open = tracing_open_generic,
1290 .read = event_enable_read,
1291 .write = event_enable_write,
1292 .llseek = default_llseek,
1293 };
1294
1295 static const struct file_operations ftrace_event_format_fops = {
1296 .open = trace_format_open,
1297 .read = seq_read,
1298 .llseek = seq_lseek,
1299 .release = seq_release,
1300 };
1301
1302 static const struct file_operations ftrace_event_id_fops = {
1303 .read = event_id_read,
1304 .llseek = default_llseek,
1305 };
1306
1307 static const struct file_operations ftrace_event_filter_fops = {
1308 .open = tracing_open_generic,
1309 .read = event_filter_read,
1310 .write = event_filter_write,
1311 .llseek = default_llseek,
1312 };
1313
1314 static const struct file_operations ftrace_subsystem_filter_fops = {
1315 .open = subsystem_open,
1316 .read = subsystem_filter_read,
1317 .write = subsystem_filter_write,
1318 .llseek = default_llseek,
1319 .release = subsystem_release,
1320 };
1321
1322 static const struct file_operations ftrace_system_enable_fops = {
1323 .open = subsystem_open,
1324 .read = system_enable_read,
1325 .write = system_enable_write,
1326 .llseek = default_llseek,
1327 .release = subsystem_release,
1328 };
1329
1330 static const struct file_operations ftrace_tr_enable_fops = {
1331 .open = system_tr_open,
1332 .read = system_enable_read,
1333 .write = system_enable_write,
1334 .llseek = default_llseek,
1335 .release = subsystem_release,
1336 };
1337
1338 static const struct file_operations ftrace_show_header_fops = {
1339 .open = tracing_open_generic,
1340 .read = show_header,
1341 .llseek = default_llseek,
1342 };
1343
1344 static int
1345 ftrace_event_open(struct inode *inode, struct file *file,
1346 const struct seq_operations *seq_ops)
1347 {
1348 struct seq_file *m;
1349 int ret;
1350
1351 ret = seq_open(file, seq_ops);
1352 if (ret < 0)
1353 return ret;
1354 m = file->private_data;
1355 /* copy tr over to seq ops */
1356 m->private = inode->i_private;
1357
1358 return ret;
1359 }
1360
1361 static int ftrace_event_release(struct inode *inode, struct file *file)
1362 {
1363 struct trace_array *tr = inode->i_private;
1364
1365 trace_array_put(tr);
1366
1367 return seq_release(inode, file);
1368 }
1369
1370 static int
1371 ftrace_event_avail_open(struct inode *inode, struct file *file)
1372 {
1373 const struct seq_operations *seq_ops = &show_event_seq_ops;
1374
1375 return ftrace_event_open(inode, file, seq_ops);
1376 }
1377
1378 static int
1379 ftrace_event_set_open(struct inode *inode, struct file *file)
1380 {
1381 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1382 struct trace_array *tr = inode->i_private;
1383 int ret;
1384
1385 if (trace_array_get(tr) < 0)
1386 return -ENODEV;
1387
1388 if ((file->f_mode & FMODE_WRITE) &&
1389 (file->f_flags & O_TRUNC))
1390 ftrace_clear_events(tr);
1391
1392 ret = ftrace_event_open(inode, file, seq_ops);
1393 if (ret < 0)
1394 trace_array_put(tr);
1395 return ret;
1396 }
1397
1398 static struct event_subsystem *
1399 create_new_subsystem(const char *name)
1400 {
1401 struct event_subsystem *system;
1402
1403 /* need to create new entry */
1404 system = kmalloc(sizeof(*system), GFP_KERNEL);
1405 if (!system)
1406 return NULL;
1407
1408 system->ref_count = 1;
1409
1410 /* Only allocate if dynamic (kprobes and modules) */
1411 if (!core_kernel_data((unsigned long)name)) {
1412 system->ref_count |= SYSTEM_FL_FREE_NAME;
1413 system->name = kstrdup(name, GFP_KERNEL);
1414 if (!system->name)
1415 goto out_free;
1416 } else
1417 system->name = name;
1418
1419 system->filter = NULL;
1420
1421 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1422 if (!system->filter)
1423 goto out_free;
1424
1425 list_add(&system->list, &event_subsystems);
1426
1427 return system;
1428
1429 out_free:
1430 if (system->ref_count & SYSTEM_FL_FREE_NAME)
1431 kfree(system->name);
1432 kfree(system);
1433 return NULL;
1434 }
1435
1436 static struct dentry *
1437 event_subsystem_dir(struct trace_array *tr, const char *name,
1438 struct ftrace_event_file *file, struct dentry *parent)
1439 {
1440 struct ftrace_subsystem_dir *dir;
1441 struct event_subsystem *system;
1442 struct dentry *entry;
1443
1444 /* First see if we did not already create this dir */
1445 list_for_each_entry(dir, &tr->systems, list) {
1446 system = dir->subsystem;
1447 if (strcmp(system->name, name) == 0) {
1448 dir->nr_events++;
1449 file->system = dir;
1450 return dir->entry;
1451 }
1452 }
1453
1454 /* Now see if the system itself exists. */
1455 list_for_each_entry(system, &event_subsystems, list) {
1456 if (strcmp(system->name, name) == 0)
1457 break;
1458 }
1459 /* Reset system variable when not found */
1460 if (&system->list == &event_subsystems)
1461 system = NULL;
1462
1463 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1464 if (!dir)
1465 goto out_fail;
1466
1467 if (!system) {
1468 system = create_new_subsystem(name);
1469 if (!system)
1470 goto out_free;
1471 } else
1472 __get_system(system);
1473
1474 dir->entry = debugfs_create_dir(name, parent);
1475 if (!dir->entry) {
1476 pr_warning("Failed to create system directory %s\n", name);
1477 __put_system(system);
1478 goto out_free;
1479 }
1480
1481 dir->tr = tr;
1482 dir->ref_count = 1;
1483 dir->nr_events = 1;
1484 dir->subsystem = system;
1485 file->system = dir;
1486
1487 entry = debugfs_create_file("filter", 0644, dir->entry, dir,
1488 &ftrace_subsystem_filter_fops);
1489 if (!entry) {
1490 kfree(system->filter);
1491 system->filter = NULL;
1492 pr_warning("Could not create debugfs '%s/filter' entry\n", name);
1493 }
1494
1495 trace_create_file("enable", 0644, dir->entry, dir,
1496 &ftrace_system_enable_fops);
1497
1498 list_add(&dir->list, &tr->systems);
1499
1500 return dir->entry;
1501
1502 out_free:
1503 kfree(dir);
1504 out_fail:
1505 /* Only print this message if failed on memory allocation */
1506 if (!dir || !system)
1507 pr_warning("No memory to create event subsystem %s\n",
1508 name);
1509 return NULL;
1510 }
1511
1512 static int
1513 event_create_dir(struct dentry *parent,
1514 struct ftrace_event_file *file,
1515 const struct file_operations *id,
1516 const struct file_operations *enable,
1517 const struct file_operations *filter,
1518 const struct file_operations *format)
1519 {
1520 struct ftrace_event_call *call = file->event_call;
1521 struct trace_array *tr = file->tr;
1522 struct list_head *head;
1523 struct dentry *d_events;
1524 int ret;
1525
1526 /*
1527 * If the trace point header did not define TRACE_SYSTEM
1528 * then the system would be called "TRACE_SYSTEM".
1529 */
1530 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1531 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1532 if (!d_events)
1533 return -ENOMEM;
1534 } else
1535 d_events = parent;
1536
1537 file->dir = debugfs_create_dir(call->name, d_events);
1538 if (!file->dir) {
1539 pr_warning("Could not create debugfs '%s' directory\n",
1540 call->name);
1541 return -1;
1542 }
1543
1544 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1545 trace_create_file("enable", 0644, file->dir, file,
1546 enable);
1547
1548 #ifdef CONFIG_PERF_EVENTS
1549 if (call->event.type && call->class->reg)
1550 trace_create_file("id", 0444, file->dir,
1551 (void *)(long)call->event.type, id);
1552 #endif
1553
1554 /*
1555 * Other events may have the same class. Only update
1556 * the fields if they are not already defined.
1557 */
1558 head = trace_get_fields(call);
1559 if (list_empty(head)) {
1560 ret = call->class->define_fields(call);
1561 if (ret < 0) {
1562 pr_warning("Could not initialize trace point"
1563 " events/%s\n", call->name);
1564 return -1;
1565 }
1566 }
1567 trace_create_file("filter", 0644, file->dir, call,
1568 filter);
1569
1570 trace_create_file("format", 0444, file->dir, call,
1571 format);
1572
1573 return 0;
1574 }
1575
1576 static void remove_event_from_tracers(struct ftrace_event_call *call)
1577 {
1578 struct ftrace_event_file *file;
1579 struct trace_array *tr;
1580
1581 do_for_each_event_file_safe(tr, file) {
1582 if (file->event_call != call)
1583 continue;
1584
1585 remove_event_file_dir(file);
1586 /*
1587 * The do_for_each_event_file_safe() is
1588 * a double loop. After finding the call for this
1589 * trace_array, we use break to jump to the next
1590 * trace_array.
1591 */
1592 break;
1593 } while_for_each_event_file();
1594 }
1595
1596 static void event_remove(struct ftrace_event_call *call)
1597 {
1598 struct trace_array *tr;
1599 struct ftrace_event_file *file;
1600
1601 do_for_each_event_file(tr, file) {
1602 if (file->event_call != call)
1603 continue;
1604 ftrace_event_enable_disable(file, 0);
1605 /*
1606 * The do_for_each_event_file() is
1607 * a double loop. After finding the call for this
1608 * trace_array, we use break to jump to the next
1609 * trace_array.
1610 */
1611 break;
1612 } while_for_each_event_file();
1613
1614 if (call->event.funcs)
1615 __unregister_ftrace_event(&call->event);
1616 remove_event_from_tracers(call);
1617 list_del(&call->list);
1618 }
1619
1620 static int event_init(struct ftrace_event_call *call)
1621 {
1622 int ret = 0;
1623
1624 if (WARN_ON(!call->name))
1625 return -EINVAL;
1626
1627 if (call->class->raw_init) {
1628 ret = call->class->raw_init(call);
1629 if (ret < 0 && ret != -ENOSYS)
1630 pr_warn("Could not initialize trace events/%s\n",
1631 call->name);
1632 }
1633
1634 return ret;
1635 }
1636
1637 static int
1638 __register_event(struct ftrace_event_call *call, struct module *mod)
1639 {
1640 int ret;
1641
1642 ret = event_init(call);
1643 if (ret < 0)
1644 return ret;
1645
1646 list_add(&call->list, &ftrace_events);
1647 call->mod = mod;
1648
1649 return 0;
1650 }
1651
1652 static struct ftrace_event_file *
1653 trace_create_new_event(struct ftrace_event_call *call,
1654 struct trace_array *tr)
1655 {
1656 struct ftrace_event_file *file;
1657
1658 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
1659 if (!file)
1660 return NULL;
1661
1662 file->event_call = call;
1663 file->tr = tr;
1664 atomic_set(&file->sm_ref, 0);
1665 list_add(&file->list, &tr->events);
1666
1667 return file;
1668 }
1669
1670 /* Add an event to a trace directory */
1671 static int
1672 __trace_add_new_event(struct ftrace_event_call *call,
1673 struct trace_array *tr,
1674 const struct file_operations *id,
1675 const struct file_operations *enable,
1676 const struct file_operations *filter,
1677 const struct file_operations *format)
1678 {
1679 struct ftrace_event_file *file;
1680
1681 file = trace_create_new_event(call, tr);
1682 if (!file)
1683 return -ENOMEM;
1684
1685 return event_create_dir(tr->event_dir, file, id, enable, filter, format);
1686 }
1687
1688 /*
1689 * Just create a decriptor for early init. A descriptor is required
1690 * for enabling events at boot. We want to enable events before
1691 * the filesystem is initialized.
1692 */
1693 static __init int
1694 __trace_early_add_new_event(struct ftrace_event_call *call,
1695 struct trace_array *tr)
1696 {
1697 struct ftrace_event_file *file;
1698
1699 file = trace_create_new_event(call, tr);
1700 if (!file)
1701 return -ENOMEM;
1702
1703 return 0;
1704 }
1705
1706 struct ftrace_module_file_ops;
1707 static void __add_event_to_tracers(struct ftrace_event_call *call,
1708 struct ftrace_module_file_ops *file_ops);
1709
1710 /* Add an additional event_call dynamically */
1711 int trace_add_event_call(struct ftrace_event_call *call)
1712 {
1713 int ret;
1714 mutex_lock(&trace_types_lock);
1715 mutex_lock(&event_mutex);
1716
1717 ret = __register_event(call, NULL);
1718 if (ret >= 0)
1719 __add_event_to_tracers(call, NULL);
1720
1721 mutex_unlock(&event_mutex);
1722 mutex_unlock(&trace_types_lock);
1723 return ret;
1724 }
1725
1726 /*
1727 * Must be called under locking of trace_types_lock, event_mutex and
1728 * trace_event_sem.
1729 */
1730 static void __trace_remove_event_call(struct ftrace_event_call *call)
1731 {
1732 event_remove(call);
1733 trace_destroy_fields(call);
1734 destroy_preds(call);
1735 }
1736
1737 static int probe_remove_event_call(struct ftrace_event_call *call)
1738 {
1739 struct trace_array *tr;
1740 struct ftrace_event_file *file;
1741
1742 #ifdef CONFIG_PERF_EVENTS
1743 if (call->perf_refcount)
1744 return -EBUSY;
1745 #endif
1746 do_for_each_event_file(tr, file) {
1747 if (file->event_call != call)
1748 continue;
1749 /*
1750 * We can't rely on ftrace_event_enable_disable(enable => 0)
1751 * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
1752 * TRACE_REG_UNREGISTER.
1753 */
1754 if (file->flags & FTRACE_EVENT_FL_ENABLED)
1755 return -EBUSY;
1756 break;
1757 } while_for_each_event_file();
1758
1759 __trace_remove_event_call(call);
1760
1761 return 0;
1762 }
1763
1764 /* Remove an event_call */
1765 int trace_remove_event_call(struct ftrace_event_call *call)
1766 {
1767 int ret;
1768
1769 mutex_lock(&trace_types_lock);
1770 mutex_lock(&event_mutex);
1771 down_write(&trace_event_sem);
1772 ret = probe_remove_event_call(call);
1773 up_write(&trace_event_sem);
1774 mutex_unlock(&event_mutex);
1775 mutex_unlock(&trace_types_lock);
1776
1777 return ret;
1778 }
1779
1780 #define for_each_event(event, start, end) \
1781 for (event = start; \
1782 (unsigned long)event < (unsigned long)end; \
1783 event++)
1784
1785 #ifdef CONFIG_MODULES
1786
1787 static LIST_HEAD(ftrace_module_file_list);
1788
1789 /*
1790 * Modules must own their file_operations to keep up with
1791 * reference counting.
1792 */
1793 struct ftrace_module_file_ops {
1794 struct list_head list;
1795 struct module *mod;
1796 struct file_operations id;
1797 struct file_operations enable;
1798 struct file_operations format;
1799 struct file_operations filter;
1800 };
1801
1802 static struct ftrace_module_file_ops *
1803 find_ftrace_file_ops(struct ftrace_module_file_ops *file_ops, struct module *mod)
1804 {
1805 /*
1806 * As event_calls are added in groups by module,
1807 * when we find one file_ops, we don't need to search for
1808 * each call in that module, as the rest should be the
1809 * same. Only search for a new one if the last one did
1810 * not match.
1811 */
1812 if (file_ops && mod == file_ops->mod)
1813 return file_ops;
1814
1815 list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1816 if (file_ops->mod == mod)
1817 return file_ops;
1818 }
1819 return NULL;
1820 }
1821
1822 static struct ftrace_module_file_ops *
1823 trace_create_file_ops(struct module *mod)
1824 {
1825 struct ftrace_module_file_ops *file_ops;
1826
1827 /*
1828 * This is a bit of a PITA. To allow for correct reference
1829 * counting, modules must "own" their file_operations.
1830 * To do this, we allocate the file operations that will be
1831 * used in the event directory.
1832 */
1833
1834 file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1835 if (!file_ops)
1836 return NULL;
1837
1838 file_ops->mod = mod;
1839
1840 file_ops->id = ftrace_event_id_fops;
1841 file_ops->id.owner = mod;
1842
1843 file_ops->enable = ftrace_enable_fops;
1844 file_ops->enable.owner = mod;
1845
1846 file_ops->filter = ftrace_event_filter_fops;
1847 file_ops->filter.owner = mod;
1848
1849 file_ops->format = ftrace_event_format_fops;
1850 file_ops->format.owner = mod;
1851
1852 list_add(&file_ops->list, &ftrace_module_file_list);
1853
1854 return file_ops;
1855 }
1856
1857 static void trace_module_add_events(struct module *mod)
1858 {
1859 struct ftrace_module_file_ops *file_ops = NULL;
1860 struct ftrace_event_call **call, **start, **end;
1861
1862 if (!mod->num_trace_events)
1863 return;
1864
1865 /* Don't add infrastructure for mods without tracepoints */
1866 if (trace_module_has_bad_taint(mod)) {
1867 pr_err("%s: module has bad taint, not creating trace events\n",
1868 mod->name);
1869 return;
1870 }
1871
1872 start = mod->trace_events;
1873 end = mod->trace_events + mod->num_trace_events;
1874
1875 if (start == end)
1876 return;
1877
1878 file_ops = trace_create_file_ops(mod);
1879 if (!file_ops)
1880 return;
1881
1882 for_each_event(call, start, end) {
1883 __register_event(*call, mod);
1884 __add_event_to_tracers(*call, file_ops);
1885 }
1886 }
1887
1888 static void trace_module_remove_events(struct module *mod)
1889 {
1890 struct ftrace_module_file_ops *file_ops;
1891 struct ftrace_event_call *call, *p;
1892 bool clear_trace = false;
1893
1894 down_write(&trace_event_sem);
1895 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1896 if (call->mod == mod) {
1897 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
1898 clear_trace = true;
1899 __trace_remove_event_call(call);
1900 }
1901 }
1902
1903 /* Now free the file_operations */
1904 list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1905 if (file_ops->mod == mod)
1906 break;
1907 }
1908 if (&file_ops->list != &ftrace_module_file_list) {
1909 list_del(&file_ops->list);
1910 kfree(file_ops);
1911 }
1912 up_write(&trace_event_sem);
1913
1914 /*
1915 * It is safest to reset the ring buffer if the module being unloaded
1916 * registered any events that were used. The only worry is if
1917 * a new module gets loaded, and takes on the same id as the events
1918 * of this module. When printing out the buffer, traced events left
1919 * over from this module may be passed to the new module events and
1920 * unexpected results may occur.
1921 */
1922 if (clear_trace)
1923 tracing_reset_all_online_cpus();
1924 }
1925
1926 static int trace_module_notify(struct notifier_block *self,
1927 unsigned long val, void *data)
1928 {
1929 struct module *mod = data;
1930
1931 mutex_lock(&trace_types_lock);
1932 mutex_lock(&event_mutex);
1933 switch (val) {
1934 case MODULE_STATE_COMING:
1935 trace_module_add_events(mod);
1936 break;
1937 case MODULE_STATE_GOING:
1938 trace_module_remove_events(mod);
1939 break;
1940 }
1941 mutex_unlock(&event_mutex);
1942 mutex_unlock(&trace_types_lock);
1943
1944 return 0;
1945 }
1946
1947 static int
1948 __trace_add_new_mod_event(struct ftrace_event_call *call,
1949 struct trace_array *tr,
1950 struct ftrace_module_file_ops *file_ops)
1951 {
1952 return __trace_add_new_event(call, tr,
1953 &file_ops->id, &file_ops->enable,
1954 &file_ops->filter, &file_ops->format);
1955 }
1956
1957 #else
1958 static inline struct ftrace_module_file_ops *
1959 find_ftrace_file_ops(struct ftrace_module_file_ops *file_ops, struct module *mod)
1960 {
1961 return NULL;
1962 }
1963 static inline int trace_module_notify(struct notifier_block *self,
1964 unsigned long val, void *data)
1965 {
1966 return 0;
1967 }
1968 static inline int
1969 __trace_add_new_mod_event(struct ftrace_event_call *call,
1970 struct trace_array *tr,
1971 struct ftrace_module_file_ops *file_ops)
1972 {
1973 return -ENODEV;
1974 }
1975 #endif /* CONFIG_MODULES */
1976
1977 /* Create a new event directory structure for a trace directory. */
1978 static void
1979 __trace_add_event_dirs(struct trace_array *tr)
1980 {
1981 struct ftrace_module_file_ops *file_ops = NULL;
1982 struct ftrace_event_call *call;
1983 int ret;
1984
1985 list_for_each_entry(call, &ftrace_events, list) {
1986 if (call->mod) {
1987 /*
1988 * Directories for events by modules need to
1989 * keep module ref counts when opened (as we don't
1990 * want the module to disappear when reading one
1991 * of these files). The file_ops keep account of
1992 * the module ref count.
1993 */
1994 file_ops = find_ftrace_file_ops(file_ops, call->mod);
1995 if (!file_ops)
1996 continue; /* Warn? */
1997 ret = __trace_add_new_mod_event(call, tr, file_ops);
1998 if (ret < 0)
1999 pr_warning("Could not create directory for event %s\n",
2000 call->name);
2001 continue;
2002 }
2003 ret = __trace_add_new_event(call, tr,
2004 &ftrace_event_id_fops,
2005 &ftrace_enable_fops,
2006 &ftrace_event_filter_fops,
2007 &ftrace_event_format_fops);
2008 if (ret < 0)
2009 pr_warning("Could not create directory for event %s\n",
2010 call->name);
2011 }
2012 }
2013
2014 #ifdef CONFIG_DYNAMIC_FTRACE
2015
2016 /* Avoid typos */
2017 #define ENABLE_EVENT_STR "enable_event"
2018 #define DISABLE_EVENT_STR "disable_event"
2019
2020 struct event_probe_data {
2021 struct ftrace_event_file *file;
2022 unsigned long count;
2023 int ref;
2024 bool enable;
2025 };
2026
2027 static struct ftrace_event_file *
2028 find_event_file(struct trace_array *tr, const char *system, const char *event)
2029 {
2030 struct ftrace_event_file *file;
2031 struct ftrace_event_call *call;
2032
2033 list_for_each_entry(file, &tr->events, list) {
2034
2035 call = file->event_call;
2036
2037 if (!call->name || !call->class || !call->class->reg)
2038 continue;
2039
2040 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2041 continue;
2042
2043 if (strcmp(event, call->name) == 0 &&
2044 strcmp(system, call->class->system) == 0)
2045 return file;
2046 }
2047 return NULL;
2048 }
2049
2050 static void
2051 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2052 {
2053 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2054 struct event_probe_data *data = *pdata;
2055
2056 if (!data)
2057 return;
2058
2059 if (data->enable)
2060 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
2061 else
2062 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
2063 }
2064
2065 static void
2066 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2067 {
2068 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2069 struct event_probe_data *data = *pdata;
2070
2071 if (!data)
2072 return;
2073
2074 if (!data->count)
2075 return;
2076
2077 /* Skip if the event is in a state we want to switch to */
2078 if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
2079 return;
2080
2081 if (data->count != -1)
2082 (data->count)--;
2083
2084 event_enable_probe(ip, parent_ip, _data);
2085 }
2086
2087 static int
2088 event_enable_print(struct seq_file *m, unsigned long ip,
2089 struct ftrace_probe_ops *ops, void *_data)
2090 {
2091 struct event_probe_data *data = _data;
2092
2093 seq_printf(m, "%ps:", (void *)ip);
2094
2095 seq_printf(m, "%s:%s:%s",
2096 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2097 data->file->event_call->class->system,
2098 data->file->event_call->name);
2099
2100 if (data->count == -1)
2101 seq_printf(m, ":unlimited\n");
2102 else
2103 seq_printf(m, ":count=%ld\n", data->count);
2104
2105 return 0;
2106 }
2107
2108 static int
2109 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
2110 void **_data)
2111 {
2112 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2113 struct event_probe_data *data = *pdata;
2114
2115 data->ref++;
2116 return 0;
2117 }
2118
2119 static void
2120 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
2121 void **_data)
2122 {
2123 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2124 struct event_probe_data *data = *pdata;
2125
2126 if (WARN_ON_ONCE(data->ref <= 0))
2127 return;
2128
2129 data->ref--;
2130 if (!data->ref) {
2131 /* Remove the SOFT_MODE flag */
2132 __ftrace_event_enable_disable(data->file, 0, 1);
2133 module_put(data->file->event_call->mod);
2134 kfree(data);
2135 }
2136 *pdata = NULL;
2137 }
2138
2139 static struct ftrace_probe_ops event_enable_probe_ops = {
2140 .func = event_enable_probe,
2141 .print = event_enable_print,
2142 .init = event_enable_init,
2143 .free = event_enable_free,
2144 };
2145
2146 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2147 .func = event_enable_count_probe,
2148 .print = event_enable_print,
2149 .init = event_enable_init,
2150 .free = event_enable_free,
2151 };
2152
2153 static struct ftrace_probe_ops event_disable_probe_ops = {
2154 .func = event_enable_probe,
2155 .print = event_enable_print,
2156 .init = event_enable_init,
2157 .free = event_enable_free,
2158 };
2159
2160 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2161 .func = event_enable_count_probe,
2162 .print = event_enable_print,
2163 .init = event_enable_init,
2164 .free = event_enable_free,
2165 };
2166
2167 static int
2168 event_enable_func(struct ftrace_hash *hash,
2169 char *glob, char *cmd, char *param, int enabled)
2170 {
2171 struct trace_array *tr = top_trace_array();
2172 struct ftrace_event_file *file;
2173 struct ftrace_probe_ops *ops;
2174 struct event_probe_data *data;
2175 const char *system;
2176 const char *event;
2177 char *number;
2178 bool enable;
2179 int ret;
2180
2181 /* hash funcs only work with set_ftrace_filter */
2182 if (!enabled)
2183 return -EINVAL;
2184
2185 if (!param)
2186 return -EINVAL;
2187
2188 system = strsep(&param, ":");
2189 if (!param)
2190 return -EINVAL;
2191
2192 event = strsep(&param, ":");
2193
2194 mutex_lock(&event_mutex);
2195
2196 ret = -EINVAL;
2197 file = find_event_file(tr, system, event);
2198 if (!file)
2199 goto out;
2200
2201 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2202
2203 if (enable)
2204 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2205 else
2206 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2207
2208 if (glob[0] == '!') {
2209 unregister_ftrace_function_probe_func(glob+1, ops);
2210 ret = 0;
2211 goto out;
2212 }
2213
2214 ret = -ENOMEM;
2215 data = kzalloc(sizeof(*data), GFP_KERNEL);
2216 if (!data)
2217 goto out;
2218
2219 data->enable = enable;
2220 data->count = -1;
2221 data->file = file;
2222
2223 if (!param)
2224 goto out_reg;
2225
2226 number = strsep(&param, ":");
2227
2228 ret = -EINVAL;
2229 if (!strlen(number))
2230 goto out_free;
2231
2232 /*
2233 * We use the callback data field (which is a pointer)
2234 * as our counter.
2235 */
2236 ret = kstrtoul(number, 0, &data->count);
2237 if (ret)
2238 goto out_free;
2239
2240 out_reg:
2241 /* Don't let event modules unload while probe registered */
2242 ret = try_module_get(file->event_call->mod);
2243 if (!ret) {
2244 ret = -EBUSY;
2245 goto out_free;
2246 }
2247
2248 ret = __ftrace_event_enable_disable(file, 1, 1);
2249 if (ret < 0)
2250 goto out_put;
2251 ret = register_ftrace_function_probe(glob, ops, data);
2252 /*
2253 * The above returns on success the # of functions enabled,
2254 * but if it didn't find any functions it returns zero.
2255 * Consider no functions a failure too.
2256 */
2257 if (!ret) {
2258 ret = -ENOENT;
2259 goto out_disable;
2260 } else if (ret < 0)
2261 goto out_disable;
2262 /* Just return zero, not the number of enabled functions */
2263 ret = 0;
2264 out:
2265 mutex_unlock(&event_mutex);
2266 return ret;
2267
2268 out_disable:
2269 __ftrace_event_enable_disable(file, 0, 1);
2270 out_put:
2271 module_put(file->event_call->mod);
2272 out_free:
2273 kfree(data);
2274 goto out;
2275 }
2276
2277 static struct ftrace_func_command event_enable_cmd = {
2278 .name = ENABLE_EVENT_STR,
2279 .func = event_enable_func,
2280 };
2281
2282 static struct ftrace_func_command event_disable_cmd = {
2283 .name = DISABLE_EVENT_STR,
2284 .func = event_enable_func,
2285 };
2286
2287 static __init int register_event_cmds(void)
2288 {
2289 int ret;
2290
2291 ret = register_ftrace_command(&event_enable_cmd);
2292 if (WARN_ON(ret < 0))
2293 return ret;
2294 ret = register_ftrace_command(&event_disable_cmd);
2295 if (WARN_ON(ret < 0))
2296 unregister_ftrace_command(&event_enable_cmd);
2297 return ret;
2298 }
2299 #else
2300 static inline int register_event_cmds(void) { return 0; }
2301 #endif /* CONFIG_DYNAMIC_FTRACE */
2302
2303 /*
2304 * The top level array has already had its ftrace_event_file
2305 * descriptors created in order to allow for early events to
2306 * be recorded. This function is called after the debugfs has been
2307 * initialized, and we now have to create the files associated
2308 * to the events.
2309 */
2310 static __init void
2311 __trace_early_add_event_dirs(struct trace_array *tr)
2312 {
2313 struct ftrace_event_file *file;
2314 int ret;
2315
2316
2317 list_for_each_entry(file, &tr->events, list) {
2318 ret = event_create_dir(tr->event_dir, file,
2319 &ftrace_event_id_fops,
2320 &ftrace_enable_fops,
2321 &ftrace_event_filter_fops,
2322 &ftrace_event_format_fops);
2323 if (ret < 0)
2324 pr_warning("Could not create directory for event %s\n",
2325 file->event_call->name);
2326 }
2327 }
2328
2329 /*
2330 * For early boot up, the top trace array requires to have
2331 * a list of events that can be enabled. This must be done before
2332 * the filesystem is set up in order to allow events to be traced
2333 * early.
2334 */
2335 static __init void
2336 __trace_early_add_events(struct trace_array *tr)
2337 {
2338 struct ftrace_event_call *call;
2339 int ret;
2340
2341 list_for_each_entry(call, &ftrace_events, list) {
2342 /* Early boot up should not have any modules loaded */
2343 if (WARN_ON_ONCE(call->mod))
2344 continue;
2345
2346 ret = __trace_early_add_new_event(call, tr);
2347 if (ret < 0)
2348 pr_warning("Could not create early event %s\n",
2349 call->name);
2350 }
2351 }
2352
2353 /* Remove the event directory structure for a trace directory. */
2354 static void
2355 __trace_remove_event_dirs(struct trace_array *tr)
2356 {
2357 struct ftrace_event_file *file, *next;
2358
2359 list_for_each_entry_safe(file, next, &tr->events, list)
2360 remove_event_file_dir(file);
2361 }
2362
2363 static void
2364 __add_event_to_tracers(struct ftrace_event_call *call,
2365 struct ftrace_module_file_ops *file_ops)
2366 {
2367 struct trace_array *tr;
2368
2369 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
2370 if (file_ops)
2371 __trace_add_new_mod_event(call, tr, file_ops);
2372 else
2373 __trace_add_new_event(call, tr,
2374 &ftrace_event_id_fops,
2375 &ftrace_enable_fops,
2376 &ftrace_event_filter_fops,
2377 &ftrace_event_format_fops);
2378 }
2379 }
2380
2381 static struct notifier_block trace_module_nb = {
2382 .notifier_call = trace_module_notify,
2383 .priority = 0,
2384 };
2385
2386 extern struct ftrace_event_call *__start_ftrace_events[];
2387 extern struct ftrace_event_call *__stop_ftrace_events[];
2388
2389 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2390
2391 static __init int setup_trace_event(char *str)
2392 {
2393 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2394 ring_buffer_expanded = true;
2395 tracing_selftest_disabled = true;
2396
2397 return 1;
2398 }
2399 __setup("trace_event=", setup_trace_event);
2400
2401 #ifdef CONFIG_MTK_SCHED_TRACERS
2402 // collect boot time ftrace, disabled by default
2403 static int boot_time_ftrace = 0;
2404
2405 static __init int setup_boot_time_ftrace(char *str)
2406 {
2407 boot_time_ftrace = 1;
2408 return 1;
2409 }
2410 __setup("boot_time_ftrace", setup_boot_time_ftrace);
2411
2412 #ifdef CONFIG_MTK_FTRACE_DEFAULT_ENABLE
2413
2414 // delay the ring buffer expand until lat_initcall stage
2415 // to avoid impacting the boot time
2416 static __init int expand_ring_buffer_init(void){
2417 if(!boot_time_ftrace)
2418 tracing_update_buffers();
2419 return 0;
2420 }
2421 late_initcall(expand_ring_buffer_init);
2422
2423 #endif /* CONFIG_MTK_FTRACE_DEFAULT_ENABLE */
2424 #endif /* CONFIG_MTK_SCHED_TRACERS */
2425
2426 /* Expects to have event_mutex held when called */
2427 static int
2428 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2429 {
2430 struct dentry *d_events;
2431 struct dentry *entry;
2432
2433 entry = debugfs_create_file("set_event", 0644, parent,
2434 tr, &ftrace_set_event_fops);
2435 if (!entry) {
2436 pr_warning("Could not create debugfs 'set_event' entry\n");
2437 return -ENOMEM;
2438 }
2439
2440 d_events = debugfs_create_dir("events", parent);
2441 if (!d_events) {
2442 pr_warning("Could not create debugfs 'events' directory\n");
2443 return -ENOMEM;
2444 }
2445
2446 /* ring buffer internal formats */
2447 trace_create_file("header_page", 0444, d_events,
2448 ring_buffer_print_page_header,
2449 &ftrace_show_header_fops);
2450
2451 trace_create_file("header_event", 0444, d_events,
2452 ring_buffer_print_entry_header,
2453 &ftrace_show_header_fops);
2454
2455 trace_create_file("enable", 0644, d_events,
2456 tr, &ftrace_tr_enable_fops);
2457
2458 tr->event_dir = d_events;
2459
2460 return 0;
2461 }
2462
2463 /**
2464 * event_trace_add_tracer - add a instance of a trace_array to events
2465 * @parent: The parent dentry to place the files/directories for events in
2466 * @tr: The trace array associated with these events
2467 *
2468 * When a new instance is created, it needs to set up its events
2469 * directory, as well as other files associated with events. It also
2470 * creates the event hierachry in the @parent/events directory.
2471 *
2472 * Returns 0 on success.
2473 */
2474 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2475 {
2476 int ret;
2477
2478 mutex_lock(&event_mutex);
2479
2480 ret = create_event_toplevel_files(parent, tr);
2481 if (ret)
2482 goto out_unlock;
2483
2484 down_write(&trace_event_sem);
2485 __trace_add_event_dirs(tr);
2486 up_write(&trace_event_sem);
2487
2488 out_unlock:
2489 mutex_unlock(&event_mutex);
2490
2491 return ret;
2492 }
2493
2494 /*
2495 * The top trace array already had its file descriptors created.
2496 * Now the files themselves need to be created.
2497 */
2498 static __init int
2499 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2500 {
2501 int ret;
2502
2503 mutex_lock(&event_mutex);
2504
2505 ret = create_event_toplevel_files(parent, tr);
2506 if (ret)
2507 goto out_unlock;
2508
2509 down_write(&trace_event_sem);
2510 __trace_early_add_event_dirs(tr);
2511 up_write(&trace_event_sem);
2512
2513 out_unlock:
2514 mutex_unlock(&event_mutex);
2515
2516 return ret;
2517 }
2518
2519 int event_trace_del_tracer(struct trace_array *tr)
2520 {
2521 mutex_lock(&event_mutex);
2522
2523 /* Disable any running events */
2524 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
2525
2526 down_write(&trace_event_sem);
2527 __trace_remove_event_dirs(tr);
2528 debugfs_remove_recursive(tr->event_dir);
2529 up_write(&trace_event_sem);
2530
2531 tr->event_dir = NULL;
2532
2533 mutex_unlock(&event_mutex);
2534
2535 return 0;
2536 }
2537
2538 static __init int event_trace_memsetup(void)
2539 {
2540 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
2541 file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC);
2542 return 0;
2543 }
2544
2545 static __init int event_trace_enable(void)
2546 {
2547 struct trace_array *tr = top_trace_array();
2548 struct ftrace_event_call **iter, *call;
2549 char *buf = bootup_event_buf;
2550 char *token;
2551 int ret;
2552
2553 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
2554
2555 call = *iter;
2556 ret = event_init(call);
2557 if (!ret)
2558 list_add(&call->list, &ftrace_events);
2559 }
2560
2561 /*
2562 * We need the top trace array to have a working set of trace
2563 * points at early init, before the debug files and directories
2564 * are created. Create the file entries now, and attach them
2565 * to the actual file dentries later.
2566 */
2567 __trace_early_add_events(tr);
2568
2569 while (true) {
2570 token = strsep(&buf, ",");
2571
2572 if (!token)
2573 break;
2574 if (!*token)
2575 continue;
2576
2577 ret = ftrace_set_clr_event(tr, token, 1);
2578 if (ret)
2579 pr_warn("Failed to enable trace event: %s\n", token);
2580 }
2581
2582 trace_printk_start_comm();
2583
2584 register_event_cmds();
2585
2586 return 0;
2587 }
2588
2589 static __init int event_trace_init(void)
2590 {
2591 struct trace_array *tr;
2592 struct dentry *d_tracer;
2593 struct dentry *entry;
2594 int ret;
2595
2596 tr = top_trace_array();
2597
2598 d_tracer = tracing_init_dentry();
2599 if (!d_tracer)
2600 return 0;
2601
2602 entry = debugfs_create_file("available_events", 0444, d_tracer,
2603 tr, &ftrace_avail_fops);
2604 if (!entry)
2605 pr_warning("Could not create debugfs "
2606 "'available_events' entry\n");
2607
2608 if (trace_define_common_fields())
2609 pr_warning("tracing: Failed to allocate common fields");
2610
2611 ret = early_event_add_tracer(d_tracer, tr);
2612 if (ret)
2613 return ret;
2614
2615 #ifdef CONFIG_MTK_FTRACE_DEFAULT_ENABLE
2616 // enable ftrace facilities
2617 mt_ftrace_enable_disable(1);
2618
2619 // only update buffer eariler if we want to collect boot-time ftrace
2620 // to avoid the boot time impacted by early-expanded ring buffer
2621 if(boot_time_ftrace)
2622 tracing_update_buffers();
2623 else
2624 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
2625 printk(KERN_INFO "[ftrace]ftrace ready...\n");
2626 #endif
2627
2628 ret = register_module_notifier(&trace_module_nb);
2629 if (ret)
2630 pr_warning("Failed to register trace events module notifier\n");
2631
2632 return 0;
2633 }
2634 early_initcall(event_trace_memsetup);
2635 core_initcall(event_trace_enable);
2636 fs_initcall(event_trace_init);
2637
2638 #ifdef CONFIG_FTRACE_STARTUP_TEST
2639
2640 static DEFINE_SPINLOCK(test_spinlock);
2641 static DEFINE_SPINLOCK(test_spinlock_irq);
2642 static DEFINE_MUTEX(test_mutex);
2643
2644 static __init void test_work(struct work_struct *dummy)
2645 {
2646 spin_lock(&test_spinlock);
2647 spin_lock_irq(&test_spinlock_irq);
2648 udelay(1);
2649 spin_unlock_irq(&test_spinlock_irq);
2650 spin_unlock(&test_spinlock);
2651
2652 mutex_lock(&test_mutex);
2653 msleep(1);
2654 mutex_unlock(&test_mutex);
2655 }
2656
2657 static __init int event_test_thread(void *unused)
2658 {
2659 void *test_malloc;
2660
2661 test_malloc = kmalloc(1234, GFP_KERNEL);
2662 if (!test_malloc)
2663 pr_info("failed to kmalloc\n");
2664
2665 schedule_on_each_cpu(test_work);
2666
2667 kfree(test_malloc);
2668
2669 set_current_state(TASK_INTERRUPTIBLE);
2670 while (!kthread_should_stop())
2671 schedule();
2672
2673 return 0;
2674 }
2675
2676 /*
2677 * Do various things that may trigger events.
2678 */
2679 static __init void event_test_stuff(void)
2680 {
2681 struct task_struct *test_thread;
2682
2683 test_thread = kthread_run(event_test_thread, NULL, "test-events");
2684 msleep(1);
2685 kthread_stop(test_thread);
2686 }
2687
2688 /*
2689 * For every trace event defined, we will test each trace point separately,
2690 * and then by groups, and finally all trace points.
2691 */
2692 static __init void event_trace_self_tests(void)
2693 {
2694 struct ftrace_subsystem_dir *dir;
2695 struct ftrace_event_file *file;
2696 struct ftrace_event_call *call;
2697 struct event_subsystem *system;
2698 struct trace_array *tr;
2699 int ret;
2700
2701 tr = top_trace_array();
2702
2703 pr_info("Running tests on trace events:\n");
2704
2705 list_for_each_entry(file, &tr->events, list) {
2706
2707 call = file->event_call;
2708
2709 /* Only test those that have a probe */
2710 if (!call->class || !call->class->probe)
2711 continue;
2712
2713 /*
2714 * Testing syscall events here is pretty useless, but
2715 * we still do it if configured. But this is time consuming.
2716 * What we really need is a user thread to perform the
2717 * syscalls as we test.
2718 */
2719 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
2720 if (call->class->system &&
2721 strcmp(call->class->system, "syscalls") == 0)
2722 continue;
2723 #endif
2724
2725 pr_info("Testing event %s: ", call->name);
2726
2727 /*
2728 * If an event is already enabled, someone is using
2729 * it and the self test should not be on.
2730 */
2731 if (file->flags & FTRACE_EVENT_FL_ENABLED) {
2732 pr_warning("Enabled event during self test!\n");
2733 WARN_ON_ONCE(1);
2734 continue;
2735 }
2736
2737 ftrace_event_enable_disable(file, 1);
2738 event_test_stuff();
2739 ftrace_event_enable_disable(file, 0);
2740
2741 pr_cont("OK\n");
2742 }
2743
2744 /* Now test at the sub system level */
2745
2746 pr_info("Running tests on trace event systems:\n");
2747
2748 list_for_each_entry(dir, &tr->systems, list) {
2749
2750 system = dir->subsystem;
2751
2752 /* the ftrace system is special, skip it */
2753 if (strcmp(system->name, "ftrace") == 0)
2754 continue;
2755
2756 pr_info("Testing event system %s: ", system->name);
2757
2758 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
2759 if (WARN_ON_ONCE(ret)) {
2760 pr_warning("error enabling system %s\n",
2761 system->name);
2762 continue;
2763 }
2764
2765 event_test_stuff();
2766
2767 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
2768 if (WARN_ON_ONCE(ret)) {
2769 pr_warning("error disabling system %s\n",
2770 system->name);
2771 continue;
2772 }
2773
2774 pr_cont("OK\n");
2775 }
2776
2777 /* Test with all events enabled */
2778
2779 pr_info("Running tests on all trace events:\n");
2780 pr_info("Testing all events: ");
2781
2782 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
2783 if (WARN_ON_ONCE(ret)) {
2784 pr_warning("error enabling all events\n");
2785 return;
2786 }
2787
2788 event_test_stuff();
2789
2790 /* reset sysname */
2791 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
2792 if (WARN_ON_ONCE(ret)) {
2793 pr_warning("error disabling all events\n");
2794 return;
2795 }
2796
2797 pr_cont("OK\n");
2798 }
2799
2800 #ifdef CONFIG_FUNCTION_TRACER
2801
2802 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
2803
2804 static void
2805 function_test_events_call(unsigned long ip, unsigned long parent_ip,
2806 struct ftrace_ops *op, struct pt_regs *pt_regs)
2807 {
2808 struct ring_buffer_event *event;
2809 struct ring_buffer *buffer;
2810 struct ftrace_entry *entry;
2811 unsigned long flags;
2812 long disabled;
2813 int cpu;
2814 int pc;
2815
2816 pc = preempt_count();
2817 preempt_disable_notrace();
2818 cpu = raw_smp_processor_id();
2819 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
2820
2821 if (disabled != 1)
2822 goto out;
2823
2824 local_save_flags(flags);
2825
2826 event = trace_current_buffer_lock_reserve(&buffer,
2827 TRACE_FN, sizeof(*entry),
2828 flags, pc);
2829 if (!event)
2830 goto out;
2831 entry = ring_buffer_event_data(event);
2832 entry->ip = ip;
2833 entry->parent_ip = parent_ip;
2834
2835 trace_buffer_unlock_commit(buffer, event, flags, pc);
2836
2837 out:
2838 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
2839 preempt_enable_notrace();
2840 }
2841
2842 static struct ftrace_ops trace_ops __initdata =
2843 {
2844 .func = function_test_events_call,
2845 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
2846 };
2847
2848 static __init void event_trace_self_test_with_function(void)
2849 {
2850 int ret;
2851 ret = register_ftrace_function(&trace_ops);
2852 if (WARN_ON(ret < 0)) {
2853 pr_info("Failed to enable function tracer for event tests\n");
2854 return;
2855 }
2856 pr_info("Running tests again, along with the function tracer\n");
2857 event_trace_self_tests();
2858 unregister_ftrace_function(&trace_ops);
2859 }
2860 #else
2861 static __init void event_trace_self_test_with_function(void)
2862 {
2863 }
2864 #endif
2865
2866 static __init int event_trace_self_tests_init(void)
2867 {
2868 if (!tracing_selftest_disabled) {
2869 event_trace_self_tests();
2870 event_trace_self_test_with_function();
2871 }
2872
2873 return 0;
2874 }
2875
2876 late_initcall(event_trace_self_tests_init);
2877
2878 #endif
kernel source for telekom puls (alcatel/mediatek)