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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#define pr_fmt(fmt) fmt
12
13#include <linux/workqueue.h>
14#include <linux/spinlock.h>
15#include <linux/kthread.h>
16#include <linux/tracefs.h>
17#include <linux/uaccess.h>
18#include <linux/bsearch.h>
19#include <linux/module.h>
20#include <linux/ctype.h>
21#include <linux/sort.h>
22#include <linux/slab.h>
23#include <linux/delay.h>
24
25#include <trace/events/sched.h>
26
27#include <asm/setup.h>
28
29#include "trace_output.h"
30
31#undef TRACE_SYSTEM
32#define TRACE_SYSTEM "TRACE_SYSTEM"
33
34DEFINE_MUTEX(event_mutex);
35
36LIST_HEAD(ftrace_events);
37static LIST_HEAD(ftrace_generic_fields);
38static LIST_HEAD(ftrace_common_fields);
39
40#define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
41
42static struct kmem_cache *field_cachep;
43static struct kmem_cache *file_cachep;
44
45static inline int system_refcount(struct event_subsystem *system)
46{
47 return system->ref_count;
48}
49
50static int system_refcount_inc(struct event_subsystem *system)
51{
52 return system->ref_count++;
53}
54
55static int system_refcount_dec(struct event_subsystem *system)
56{
57 return --system->ref_count;
58}
59
60/* Double loops, do not use break, only goto's work */
61#define do_for_each_event_file(tr, file) \
62 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
63 list_for_each_entry(file, &tr->events, list)
64
65#define do_for_each_event_file_safe(tr, file) \
66 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
67 struct trace_event_file *___n; \
68 list_for_each_entry_safe(file, ___n, &tr->events, list)
69
70#define while_for_each_event_file() \
71 }
72
73static struct list_head *
74trace_get_fields(struct trace_event_call *event_call)
75{
76 if (!event_call->class->get_fields)
77 return &event_call->class->fields;
78 return event_call->class->get_fields(event_call);
79}
80
81static struct ftrace_event_field *
82__find_event_field(struct list_head *head, char *name)
83{
84 struct ftrace_event_field *field;
85
86 list_for_each_entry(field, head, link) {
87 if (!strcmp(field->name, name))
88 return field;
89 }
90
91 return NULL;
92}
93
94struct ftrace_event_field *
95trace_find_event_field(struct trace_event_call *call, char *name)
96{
97 struct ftrace_event_field *field;
98 struct list_head *head;
99
100 head = trace_get_fields(call);
101 field = __find_event_field(head, name);
102 if (field)
103 return field;
104
105 field = __find_event_field(&ftrace_generic_fields, name);
106 if (field)
107 return field;
108
109 return __find_event_field(&ftrace_common_fields, name);
110}
111
112static int __trace_define_field(struct list_head *head, const char *type,
113 const char *name, int offset, int size,
114 int is_signed, int filter_type)
115{
116 struct ftrace_event_field *field;
117
118 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
119 if (!field)
120 return -ENOMEM;
121
122 field->name = name;
123 field->type = type;
124
125 if (filter_type == FILTER_OTHER)
126 field->filter_type = filter_assign_type(type);
127 else
128 field->filter_type = filter_type;
129
130 field->offset = offset;
131 field->size = size;
132 field->is_signed = is_signed;
133
134 list_add(&field->link, head);
135
136 return 0;
137}
138
139int trace_define_field(struct trace_event_call *call, const char *type,
140 const char *name, int offset, int size, int is_signed,
141 int filter_type)
142{
143 struct list_head *head;
144
145 if (WARN_ON(!call->class))
146 return 0;
147
148 head = trace_get_fields(call);
149 return __trace_define_field(head, type, name, offset, size,
150 is_signed, filter_type);
151}
152EXPORT_SYMBOL_GPL(trace_define_field);
153
154#define __generic_field(type, item, filter_type) \
155 ret = __trace_define_field(&ftrace_generic_fields, #type, \
156 #item, 0, 0, is_signed_type(type), \
157 filter_type); \
158 if (ret) \
159 return ret;
160
161#define __common_field(type, item) \
162 ret = __trace_define_field(&ftrace_common_fields, #type, \
163 "common_" #item, \
164 offsetof(typeof(ent), item), \
165 sizeof(ent.item), \
166 is_signed_type(type), FILTER_OTHER); \
167 if (ret) \
168 return ret;
169
170static int trace_define_generic_fields(void)
171{
172 int ret;
173
174 __generic_field(int, CPU, FILTER_CPU);
175 __generic_field(int, cpu, FILTER_CPU);
176 __generic_field(char *, COMM, FILTER_COMM);
177 __generic_field(char *, comm, FILTER_COMM);
178
179 return ret;
180}
181
182static int trace_define_common_fields(void)
183{
184 int ret;
185 struct trace_entry ent;
186
187 __common_field(unsigned short, type);
188 __common_field(unsigned char, flags);
189 __common_field(unsigned char, preempt_count);
190 __common_field(int, pid);
191
192 return ret;
193}
194
195static void trace_destroy_fields(struct trace_event_call *call)
196{
197 struct ftrace_event_field *field, *next;
198 struct list_head *head;
199
200 head = trace_get_fields(call);
201 list_for_each_entry_safe(field, next, head, link) {
202 list_del(&field->link);
203 kmem_cache_free(field_cachep, field);
204 }
205}
206
207int trace_event_raw_init(struct trace_event_call *call)
208{
209 int id;
210
211 id = register_trace_event(&call->event);
212 if (!id)
213 return -ENODEV;
214
215 return 0;
216}
217EXPORT_SYMBOL_GPL(trace_event_raw_init);
218
219bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
220{
221 struct trace_array *tr = trace_file->tr;
222 struct trace_array_cpu *data;
223 struct trace_pid_list *pid_list;
224
225 pid_list = rcu_dereference_sched(tr->filtered_pids);
226 if (!pid_list)
227 return false;
228
229 data = this_cpu_ptr(tr->trace_buffer.data);
230
231 return data->ignore_pid;
232}
233EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
234
235void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
236 struct trace_event_file *trace_file,
237 unsigned long len)
238{
239 struct trace_event_call *event_call = trace_file->event_call;
240
241 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
242 trace_event_ignore_this_pid(trace_file))
243 return NULL;
244
245 local_save_flags(fbuffer->flags);
246 fbuffer->pc = preempt_count();
247 fbuffer->trace_file = trace_file;
248
249 fbuffer->event =
250 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
251 event_call->event.type, len,
252 fbuffer->flags, fbuffer->pc);
253 if (!fbuffer->event)
254 return NULL;
255
256 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
257 return fbuffer->entry;
258}
259EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
260
261static DEFINE_SPINLOCK(tracepoint_iter_lock);
262
263static void output_printk(struct trace_event_buffer *fbuffer)
264{
265 struct trace_event_call *event_call;
266 struct trace_event *event;
267 unsigned long flags;
268 struct trace_iterator *iter = tracepoint_print_iter;
269
270 if (!iter)
271 return;
272
273 event_call = fbuffer->trace_file->event_call;
274 if (!event_call || !event_call->event.funcs ||
275 !event_call->event.funcs->trace)
276 return;
277
278 event = &fbuffer->trace_file->event_call->event;
279
280 spin_lock_irqsave(&tracepoint_iter_lock, flags);
281 trace_seq_init(&iter->seq);
282 iter->ent = fbuffer->entry;
283 event_call->event.funcs->trace(iter, 0, event);
284 trace_seq_putc(&iter->seq, 0);
285 printk("%s", iter->seq.buffer);
286
287 spin_unlock_irqrestore(&tracepoint_iter_lock, flags);
288}
289
290void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)
291{
292 if (tracepoint_printk)
293 output_printk(fbuffer);
294
295 event_trigger_unlock_commit(fbuffer->trace_file, fbuffer->buffer,
296 fbuffer->event, fbuffer->entry,
297 fbuffer->flags, fbuffer->pc);
298}
299EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
300
301int trace_event_reg(struct trace_event_call *call,
302 enum trace_reg type, void *data)
303{
304 struct trace_event_file *file = data;
305
306 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
307 switch (type) {
308 case TRACE_REG_REGISTER:
309 return tracepoint_probe_register(call->tp,
310 call->class->probe,
311 file);
312 case TRACE_REG_UNREGISTER:
313 tracepoint_probe_unregister(call->tp,
314 call->class->probe,
315 file);
316 return 0;
317
318#ifdef CONFIG_PERF_EVENTS
319 case TRACE_REG_PERF_REGISTER:
320 return tracepoint_probe_register(call->tp,
321 call->class->perf_probe,
322 call);
323 case TRACE_REG_PERF_UNREGISTER:
324 tracepoint_probe_unregister(call->tp,
325 call->class->perf_probe,
326 call);
327 return 0;
328 case TRACE_REG_PERF_OPEN:
329 case TRACE_REG_PERF_CLOSE:
330 case TRACE_REG_PERF_ADD:
331 case TRACE_REG_PERF_DEL:
332 return 0;
333#endif
334 }
335 return 0;
336}
337EXPORT_SYMBOL_GPL(trace_event_reg);
338
339void trace_event_enable_cmd_record(bool enable)
340{
341 struct trace_event_file *file;
342 struct trace_array *tr;
343
344 mutex_lock(&event_mutex);
345 do_for_each_event_file(tr, file) {
346
347 if (!(file->flags & EVENT_FILE_FL_ENABLED))
348 continue;
349
350 if (enable) {
351 tracing_start_cmdline_record();
352 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
353 } else {
354 tracing_stop_cmdline_record();
355 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
356 }
357 } while_for_each_event_file();
358 mutex_unlock(&event_mutex);
359}
360
361static int __ftrace_event_enable_disable(struct trace_event_file *file,
362 int enable, int soft_disable)
363{
364 struct trace_event_call *call = file->event_call;
365 struct trace_array *tr = file->tr;
366 int ret = 0;
367 int disable;
368
369 switch (enable) {
370 case 0:
371 /*
372 * When soft_disable is set and enable is cleared, the sm_ref
373 * reference counter is decremented. If it reaches 0, we want
374 * to clear the SOFT_DISABLED flag but leave the event in the
375 * state that it was. That is, if the event was enabled and
376 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
377 * is set we do not want the event to be enabled before we
378 * clear the bit.
379 *
380 * When soft_disable is not set but the SOFT_MODE flag is,
381 * we do nothing. Do not disable the tracepoint, otherwise
382 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
383 */
384 if (soft_disable) {
385 if (atomic_dec_return(&file->sm_ref) > 0)
386 break;
387 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
388 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
389 } else
390 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
391
392 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
393 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
394 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
395 tracing_stop_cmdline_record();
396 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
397 }
398 call->class->reg(call, TRACE_REG_UNREGISTER, file);
399 }
400 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
401 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
402 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
403 else
404 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
405 break;
406 case 1:
407 /*
408 * When soft_disable is set and enable is set, we want to
409 * register the tracepoint for the event, but leave the event
410 * as is. That means, if the event was already enabled, we do
411 * nothing (but set SOFT_MODE). If the event is disabled, we
412 * set SOFT_DISABLED before enabling the event tracepoint, so
413 * it still seems to be disabled.
414 */
415 if (!soft_disable)
416 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
417 else {
418 if (atomic_inc_return(&file->sm_ref) > 1)
419 break;
420 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
421 }
422
423 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
424
425 /* Keep the event disabled, when going to SOFT_MODE. */
426 if (soft_disable)
427 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
428
429 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
430 tracing_start_cmdline_record();
431 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
432 }
433 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
434 if (ret) {
435 tracing_stop_cmdline_record();
436 pr_info("event trace: Could not enable event "
437 "%s\n", trace_event_name(call));
438 break;
439 }
440 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
441
442 /* WAS_ENABLED gets set but never cleared. */
443 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
444 }
445 break;
446 }
447
448 return ret;
449}
450
451int trace_event_enable_disable(struct trace_event_file *file,
452 int enable, int soft_disable)
453{
454 return __ftrace_event_enable_disable(file, enable, soft_disable);
455}
456
457static int ftrace_event_enable_disable(struct trace_event_file *file,
458 int enable)
459{
460 return __ftrace_event_enable_disable(file, enable, 0);
461}
462
463static void ftrace_clear_events(struct trace_array *tr)
464{
465 struct trace_event_file *file;
466
467 mutex_lock(&event_mutex);
468 list_for_each_entry(file, &tr->events, list) {
469 ftrace_event_enable_disable(file, 0);
470 }
471 mutex_unlock(&event_mutex);
472}
473
474static int cmp_pid(const void *key, const void *elt)
475{
476 const pid_t *search_pid = key;
477 const pid_t *pid = elt;
478
479 if (*search_pid == *pid)
480 return 0;
481 if (*search_pid < *pid)
482 return -1;
483 return 1;
484}
485
486static bool
487check_ignore_pid(struct trace_pid_list *filtered_pids, struct task_struct *task)
488{
489 pid_t search_pid;
490 pid_t *pid;
491
492 /*
493 * Return false, because if filtered_pids does not exist,
494 * all pids are good to trace.
495 */
496 if (!filtered_pids)
497 return false;
498
499 search_pid = task->pid;
500
501 pid = bsearch(&search_pid, filtered_pids->pids,
502 filtered_pids->nr_pids, sizeof(pid_t),
503 cmp_pid);
504 if (!pid)
505 return true;
506
507 return false;
508}
509
510static void
511event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
512 struct task_struct *prev, struct task_struct *next)
513{
514 struct trace_array *tr = data;
515 struct trace_pid_list *pid_list;
516
517 pid_list = rcu_dereference_sched(tr->filtered_pids);
518
519 this_cpu_write(tr->trace_buffer.data->ignore_pid,
520 check_ignore_pid(pid_list, prev) &&
521 check_ignore_pid(pid_list, next));
522}
523
524static void
525event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
526 struct task_struct *prev, struct task_struct *next)
527{
528 struct trace_array *tr = data;
529 struct trace_pid_list *pid_list;
530
531 pid_list = rcu_dereference_sched(tr->filtered_pids);
532
533 this_cpu_write(tr->trace_buffer.data->ignore_pid,
534 check_ignore_pid(pid_list, next));
535}
536
537static void
538event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
539{
540 struct trace_array *tr = data;
541 struct trace_pid_list *pid_list;
542
543 /* Nothing to do if we are already tracing */
544 if (!this_cpu_read(tr->trace_buffer.data->ignore_pid))
545 return;
546
547 pid_list = rcu_dereference_sched(tr->filtered_pids);
548
549 this_cpu_write(tr->trace_buffer.data->ignore_pid,
550 check_ignore_pid(pid_list, task));
551}
552
553static void
554event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
555{
556 struct trace_array *tr = data;
557 struct trace_pid_list *pid_list;
558
559 /* Nothing to do if we are not tracing */
560 if (this_cpu_read(tr->trace_buffer.data->ignore_pid))
561 return;
562
563 pid_list = rcu_dereference_sched(tr->filtered_pids);
564
565 /* Set tracing if current is enabled */
566 this_cpu_write(tr->trace_buffer.data->ignore_pid,
567 check_ignore_pid(pid_list, current));
568}
569
570static void __ftrace_clear_event_pids(struct trace_array *tr)
571{
572 struct trace_pid_list *pid_list;
573 struct trace_event_file *file;
574 int cpu;
575
576 pid_list = rcu_dereference_protected(tr->filtered_pids,
577 lockdep_is_held(&event_mutex));
578 if (!pid_list)
579 return;
580
581 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
582 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
583
584 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
585 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
586
587 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
588 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
589
590 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
591 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
592
593 list_for_each_entry(file, &tr->events, list) {
594 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
595 }
596
597 for_each_possible_cpu(cpu)
598 per_cpu_ptr(tr->trace_buffer.data, cpu)->ignore_pid = false;
599
600 rcu_assign_pointer(tr->filtered_pids, NULL);
601
602 /* Wait till all users are no longer using pid filtering */
603 synchronize_sched();
604
605 free_pages((unsigned long)pid_list->pids, pid_list->order);
606 kfree(pid_list);
607}
608
609static void ftrace_clear_event_pids(struct trace_array *tr)
610{
611 mutex_lock(&event_mutex);
612 __ftrace_clear_event_pids(tr);
613 mutex_unlock(&event_mutex);
614}
615
616static void __put_system(struct event_subsystem *system)
617{
618 struct event_filter *filter = system->filter;
619
620 WARN_ON_ONCE(system_refcount(system) == 0);
621 if (system_refcount_dec(system))
622 return;
623
624 list_del(&system->list);
625
626 if (filter) {
627 kfree(filter->filter_string);
628 kfree(filter);
629 }
630 kfree_const(system->name);
631 kfree(system);
632}
633
634static void __get_system(struct event_subsystem *system)
635{
636 WARN_ON_ONCE(system_refcount(system) == 0);
637 system_refcount_inc(system);
638}
639
640static void __get_system_dir(struct trace_subsystem_dir *dir)
641{
642 WARN_ON_ONCE(dir->ref_count == 0);
643 dir->ref_count++;
644 __get_system(dir->subsystem);
645}
646
647static void __put_system_dir(struct trace_subsystem_dir *dir)
648{
649 WARN_ON_ONCE(dir->ref_count == 0);
650 /* If the subsystem is about to be freed, the dir must be too */
651 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
652
653 __put_system(dir->subsystem);
654 if (!--dir->ref_count)
655 kfree(dir);
656}
657
658static void put_system(struct trace_subsystem_dir *dir)
659{
660 mutex_lock(&event_mutex);
661 __put_system_dir(dir);
662 mutex_unlock(&event_mutex);
663}
664
665static void remove_subsystem(struct trace_subsystem_dir *dir)
666{
667 if (!dir)
668 return;
669
670 if (!--dir->nr_events) {
671 tracefs_remove_recursive(dir->entry);
672 list_del(&dir->list);
673 __put_system_dir(dir);
674 }
675}
676
677static void remove_event_file_dir(struct trace_event_file *file)
678{
679 struct dentry *dir = file->dir;
680 struct dentry *child;
681
682 if (dir) {
683 spin_lock(&dir->d_lock); /* probably unneeded */
684 list_for_each_entry(child, &dir->d_subdirs, d_child) {
685 if (d_really_is_positive(child)) /* probably unneeded */
686 d_inode(child)->i_private = NULL;
687 }
688 spin_unlock(&dir->d_lock);
689
690 tracefs_remove_recursive(dir);
691 }
692
693 list_del(&file->list);
694 remove_subsystem(file->system);
695 free_event_filter(file->filter);
696 kmem_cache_free(file_cachep, file);
697}
698
699/*
700 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
701 */
702static int
703__ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
704 const char *sub, const char *event, int set)
705{
706 struct trace_event_file *file;
707 struct trace_event_call *call;
708 const char *name;
709 int ret = -EINVAL;
710
711 list_for_each_entry(file, &tr->events, list) {
712
713 call = file->event_call;
714 name = trace_event_name(call);
715
716 if (!name || !call->class || !call->class->reg)
717 continue;
718
719 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
720 continue;
721
722 if (match &&
723 strcmp(match, name) != 0 &&
724 strcmp(match, call->class->system) != 0)
725 continue;
726
727 if (sub && strcmp(sub, call->class->system) != 0)
728 continue;
729
730 if (event && strcmp(event, name) != 0)
731 continue;
732
733 ftrace_event_enable_disable(file, set);
734
735 ret = 0;
736 }
737
738 return ret;
739}
740
741static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
742 const char *sub, const char *event, int set)
743{
744 int ret;
745
746 mutex_lock(&event_mutex);
747 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
748 mutex_unlock(&event_mutex);
749
750 return ret;
751}
752
753static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
754{
755 char *event = NULL, *sub = NULL, *match;
756 int ret;
757
758 /*
759 * The buf format can be <subsystem>:<event-name>
760 * *:<event-name> means any event by that name.
761 * :<event-name> is the same.
762 *
763 * <subsystem>:* means all events in that subsystem
764 * <subsystem>: means the same.
765 *
766 * <name> (no ':') means all events in a subsystem with
767 * the name <name> or any event that matches <name>
768 */
769
770 match = strsep(&buf, ":");
771 if (buf) {
772 sub = match;
773 event = buf;
774 match = NULL;
775
776 if (!strlen(sub) || strcmp(sub, "*") == 0)
777 sub = NULL;
778 if (!strlen(event) || strcmp(event, "*") == 0)
779 event = NULL;
780 }
781
782 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
783
784 /* Put back the colon to allow this to be called again */
785 if (buf)
786 *(buf - 1) = ':';
787
788 return ret;
789}
790
791/**
792 * trace_set_clr_event - enable or disable an event
793 * @system: system name to match (NULL for any system)
794 * @event: event name to match (NULL for all events, within system)
795 * @set: 1 to enable, 0 to disable
796 *
797 * This is a way for other parts of the kernel to enable or disable
798 * event recording.
799 *
800 * Returns 0 on success, -EINVAL if the parameters do not match any
801 * registered events.
802 */
803int trace_set_clr_event(const char *system, const char *event, int set)
804{
805 struct trace_array *tr = top_trace_array();
806
807 if (!tr)
808 return -ENODEV;
809
810 return __ftrace_set_clr_event(tr, NULL, system, event, set);
811}
812EXPORT_SYMBOL_GPL(trace_set_clr_event);
813
814/* 128 should be much more than enough */
815#define EVENT_BUF_SIZE 127
816
817static ssize_t
818ftrace_event_write(struct file *file, const char __user *ubuf,
819 size_t cnt, loff_t *ppos)
820{
821 struct trace_parser parser;
822 struct seq_file *m = file->private_data;
823 struct trace_array *tr = m->private;
824 ssize_t read, ret;
825
826 if (!cnt)
827 return 0;
828
829 ret = tracing_update_buffers();
830 if (ret < 0)
831 return ret;
832
833 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
834 return -ENOMEM;
835
836 read = trace_get_user(&parser, ubuf, cnt, ppos);
837
838 if (read >= 0 && trace_parser_loaded((&parser))) {
839 int set = 1;
840
841 if (*parser.buffer == '!')
842 set = 0;
843
844 parser.buffer[parser.idx] = 0;
845
846 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
847 if (ret)
848 goto out_put;
849 }
850
851 ret = read;
852
853 out_put:
854 trace_parser_put(&parser);
855
856 return ret;
857}
858
859static void *
860t_next(struct seq_file *m, void *v, loff_t *pos)
861{
862 struct trace_event_file *file = v;
863 struct trace_event_call *call;
864 struct trace_array *tr = m->private;
865
866 (*pos)++;
867
868 list_for_each_entry_continue(file, &tr->events, list) {
869 call = file->event_call;
870 /*
871 * The ftrace subsystem is for showing formats only.
872 * They can not be enabled or disabled via the event files.
873 */
874 if (call->class && call->class->reg &&
875 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
876 return file;
877 }
878
879 return NULL;
880}
881
882static void *t_start(struct seq_file *m, loff_t *pos)
883{
884 struct trace_event_file *file;
885 struct trace_array *tr = m->private;
886 loff_t l;
887
888 mutex_lock(&event_mutex);
889
890 file = list_entry(&tr->events, struct trace_event_file, list);
891 for (l = 0; l <= *pos; ) {
892 file = t_next(m, file, &l);
893 if (!file)
894 break;
895 }
896 return file;
897}
898
899static void *
900s_next(struct seq_file *m, void *v, loff_t *pos)
901{
902 struct trace_event_file *file = v;
903 struct trace_array *tr = m->private;
904
905 (*pos)++;
906
907 list_for_each_entry_continue(file, &tr->events, list) {
908 if (file->flags & EVENT_FILE_FL_ENABLED)
909 return file;
910 }
911
912 return NULL;
913}
914
915static void *s_start(struct seq_file *m, loff_t *pos)
916{
917 struct trace_event_file *file;
918 struct trace_array *tr = m->private;
919 loff_t l;
920
921 mutex_lock(&event_mutex);
922
923 file = list_entry(&tr->events, struct trace_event_file, list);
924 for (l = 0; l <= *pos; ) {
925 file = s_next(m, file, &l);
926 if (!file)
927 break;
928 }
929 return file;
930}
931
932static int t_show(struct seq_file *m, void *v)
933{
934 struct trace_event_file *file = v;
935 struct trace_event_call *call = file->event_call;
936
937 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
938 seq_printf(m, "%s:", call->class->system);
939 seq_printf(m, "%s\n", trace_event_name(call));
940
941 return 0;
942}
943
944static void t_stop(struct seq_file *m, void *p)
945{
946 mutex_unlock(&event_mutex);
947}
948
949static void *p_start(struct seq_file *m, loff_t *pos)
950 __acquires(RCU)
951{
952 struct trace_pid_list *pid_list;
953 struct trace_array *tr = m->private;
954
955 /*
956 * Grab the mutex, to keep calls to p_next() having the same
957 * tr->filtered_pids as p_start() has.
958 * If we just passed the tr->filtered_pids around, then RCU would
959 * have been enough, but doing that makes things more complex.
960 */
961 mutex_lock(&event_mutex);
962 rcu_read_lock_sched();
963
964 pid_list = rcu_dereference_sched(tr->filtered_pids);
965
966 if (!pid_list || *pos >= pid_list->nr_pids)
967 return NULL;
968
969 return (void *)&pid_list->pids[*pos];
970}
971
972static void p_stop(struct seq_file *m, void *p)
973 __releases(RCU)
974{
975 rcu_read_unlock_sched();
976 mutex_unlock(&event_mutex);
977}
978
979static void *
980p_next(struct seq_file *m, void *v, loff_t *pos)
981{
982 struct trace_array *tr = m->private;
983 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
984
985 (*pos)++;
986
987 if (*pos >= pid_list->nr_pids)
988 return NULL;
989
990 return (void *)&pid_list->pids[*pos];
991}
992
993static int p_show(struct seq_file *m, void *v)
994{
995 pid_t *pid = v;
996
997 seq_printf(m, "%d\n", *pid);
998 return 0;
999}
1000
1001static ssize_t
1002event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1003 loff_t *ppos)
1004{
1005 struct trace_event_file *file;
1006 unsigned long flags;
1007 char buf[4] = "0";
1008
1009 mutex_lock(&event_mutex);
1010 file = event_file_data(filp);
1011 if (likely(file))
1012 flags = file->flags;
1013 mutex_unlock(&event_mutex);
1014
1015 if (!file)
1016 return -ENODEV;
1017
1018 if (flags & EVENT_FILE_FL_ENABLED &&
1019 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1020 strcpy(buf, "1");
1021
1022 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1023 flags & EVENT_FILE_FL_SOFT_MODE)
1024 strcat(buf, "*");
1025
1026 strcat(buf, "\n");
1027
1028 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1029}
1030
1031static ssize_t
1032event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1033 loff_t *ppos)
1034{
1035 struct trace_event_file *file;
1036 unsigned long val;
1037 int ret;
1038
1039 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1040 if (ret)
1041 return ret;
1042
1043 ret = tracing_update_buffers();
1044 if (ret < 0)
1045 return ret;
1046
1047 switch (val) {
1048 case 0:
1049 case 1:
1050 ret = -ENODEV;
1051 mutex_lock(&event_mutex);
1052 file = event_file_data(filp);
1053 if (likely(file))
1054 ret = ftrace_event_enable_disable(file, val);
1055 mutex_unlock(&event_mutex);
1056 break;
1057
1058 default:
1059 return -EINVAL;
1060 }
1061
1062 *ppos += cnt;
1063
1064 return ret ? ret : cnt;
1065}
1066
1067static ssize_t
1068system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1069 loff_t *ppos)
1070{
1071 const char set_to_char[4] = { '?', '0', '1', 'X' };
1072 struct trace_subsystem_dir *dir = filp->private_data;
1073 struct event_subsystem *system = dir->subsystem;
1074 struct trace_event_call *call;
1075 struct trace_event_file *file;
1076 struct trace_array *tr = dir->tr;
1077 char buf[2];
1078 int set = 0;
1079 int ret;
1080
1081 mutex_lock(&event_mutex);
1082 list_for_each_entry(file, &tr->events, list) {
1083 call = file->event_call;
1084 if (!trace_event_name(call) || !call->class || !call->class->reg)
1085 continue;
1086
1087 if (system && strcmp(call->class->system, system->name) != 0)
1088 continue;
1089
1090 /*
1091 * We need to find out if all the events are set
1092 * or if all events or cleared, or if we have
1093 * a mixture.
1094 */
1095 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1096
1097 /*
1098 * If we have a mixture, no need to look further.
1099 */
1100 if (set == 3)
1101 break;
1102 }
1103 mutex_unlock(&event_mutex);
1104
1105 buf[0] = set_to_char[set];
1106 buf[1] = '\n';
1107
1108 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1109
1110 return ret;
1111}
1112
1113static ssize_t
1114system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1115 loff_t *ppos)
1116{
1117 struct trace_subsystem_dir *dir = filp->private_data;
1118 struct event_subsystem *system = dir->subsystem;
1119 const char *name = NULL;
1120 unsigned long val;
1121 ssize_t ret;
1122
1123 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1124 if (ret)
1125 return ret;
1126
1127 ret = tracing_update_buffers();
1128 if (ret < 0)
1129 return ret;
1130
1131 if (val != 0 && val != 1)
1132 return -EINVAL;
1133
1134 /*
1135 * Opening of "enable" adds a ref count to system,
1136 * so the name is safe to use.
1137 */
1138 if (system)
1139 name = system->name;
1140
1141 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1142 if (ret)
1143 goto out;
1144
1145 ret = cnt;
1146
1147out:
1148 *ppos += cnt;
1149
1150 return ret;
1151}
1152
1153enum {
1154 FORMAT_HEADER = 1,
1155 FORMAT_FIELD_SEPERATOR = 2,
1156 FORMAT_PRINTFMT = 3,
1157};
1158
1159static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1160{
1161 struct trace_event_call *call = event_file_data(m->private);
1162 struct list_head *common_head = &ftrace_common_fields;
1163 struct list_head *head = trace_get_fields(call);
1164 struct list_head *node = v;
1165
1166 (*pos)++;
1167
1168 switch ((unsigned long)v) {
1169 case FORMAT_HEADER:
1170 node = common_head;
1171 break;
1172
1173 case FORMAT_FIELD_SEPERATOR:
1174 node = head;
1175 break;
1176
1177 case FORMAT_PRINTFMT:
1178 /* all done */
1179 return NULL;
1180 }
1181
1182 node = node->prev;
1183 if (node == common_head)
1184 return (void *)FORMAT_FIELD_SEPERATOR;
1185 else if (node == head)
1186 return (void *)FORMAT_PRINTFMT;
1187 else
1188 return node;
1189}
1190
1191static int f_show(struct seq_file *m, void *v)
1192{
1193 struct trace_event_call *call = event_file_data(m->private);
1194 struct ftrace_event_field *field;
1195 const char *array_descriptor;
1196
1197 switch ((unsigned long)v) {
1198 case FORMAT_HEADER:
1199 seq_printf(m, "name: %s\n", trace_event_name(call));
1200 seq_printf(m, "ID: %d\n", call->event.type);
1201 seq_puts(m, "format:\n");
1202 return 0;
1203
1204 case FORMAT_FIELD_SEPERATOR:
1205 seq_putc(m, '\n');
1206 return 0;
1207
1208 case FORMAT_PRINTFMT:
1209 seq_printf(m, "\nprint fmt: %s\n",
1210 call->print_fmt);
1211 return 0;
1212 }
1213
1214 field = list_entry(v, struct ftrace_event_field, link);
1215 /*
1216 * Smartly shows the array type(except dynamic array).
1217 * Normal:
1218 * field:TYPE VAR
1219 * If TYPE := TYPE[LEN], it is shown:
1220 * field:TYPE VAR[LEN]
1221 */
1222 array_descriptor = strchr(field->type, '[');
1223
1224 if (!strncmp(field->type, "__data_loc", 10))
1225 array_descriptor = NULL;
1226
1227 if (!array_descriptor)
1228 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1229 field->type, field->name, field->offset,
1230 field->size, !!field->is_signed);
1231 else
1232 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1233 (int)(array_descriptor - field->type),
1234 field->type, field->name,
1235 array_descriptor, field->offset,
1236 field->size, !!field->is_signed);
1237
1238 return 0;
1239}
1240
1241static void *f_start(struct seq_file *m, loff_t *pos)
1242{
1243 void *p = (void *)FORMAT_HEADER;
1244 loff_t l = 0;
1245
1246 /* ->stop() is called even if ->start() fails */
1247 mutex_lock(&event_mutex);
1248 if (!event_file_data(m->private))
1249 return ERR_PTR(-ENODEV);
1250
1251 while (l < *pos && p)
1252 p = f_next(m, p, &l);
1253
1254 return p;
1255}
1256
1257static void f_stop(struct seq_file *m, void *p)
1258{
1259 mutex_unlock(&event_mutex);
1260}
1261
1262static const struct seq_operations trace_format_seq_ops = {
1263 .start = f_start,
1264 .next = f_next,
1265 .stop = f_stop,
1266 .show = f_show,
1267};
1268
1269static int trace_format_open(struct inode *inode, struct file *file)
1270{
1271 struct seq_file *m;
1272 int ret;
1273
1274 ret = seq_open(file, &trace_format_seq_ops);
1275 if (ret < 0)
1276 return ret;
1277
1278 m = file->private_data;
1279 m->private = file;
1280
1281 return 0;
1282}
1283
1284static ssize_t
1285event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1286{
1287 int id = (long)event_file_data(filp);
1288 char buf[32];
1289 int len;
1290
1291 if (*ppos)
1292 return 0;
1293
1294 if (unlikely(!id))
1295 return -ENODEV;
1296
1297 len = sprintf(buf, "%d\n", id);
1298
1299 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1300}
1301
1302static ssize_t
1303event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1304 loff_t *ppos)
1305{
1306 struct trace_event_file *file;
1307 struct trace_seq *s;
1308 int r = -ENODEV;
1309
1310 if (*ppos)
1311 return 0;
1312
1313 s = kmalloc(sizeof(*s), GFP_KERNEL);
1314
1315 if (!s)
1316 return -ENOMEM;
1317
1318 trace_seq_init(s);
1319
1320 mutex_lock(&event_mutex);
1321 file = event_file_data(filp);
1322 if (file)
1323 print_event_filter(file, s);
1324 mutex_unlock(&event_mutex);
1325
1326 if (file)
1327 r = simple_read_from_buffer(ubuf, cnt, ppos,
1328 s->buffer, trace_seq_used(s));
1329
1330 kfree(s);
1331
1332 return r;
1333}
1334
1335static ssize_t
1336event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1337 loff_t *ppos)
1338{
1339 struct trace_event_file *file;
1340 char *buf;
1341 int err = -ENODEV;
1342
1343 if (cnt >= PAGE_SIZE)
1344 return -EINVAL;
1345
1346 buf = memdup_user_nul(ubuf, cnt);
1347 if (IS_ERR(buf))
1348 return PTR_ERR(buf);
1349
1350 mutex_lock(&event_mutex);
1351 file = event_file_data(filp);
1352 if (file)
1353 err = apply_event_filter(file, buf);
1354 mutex_unlock(&event_mutex);
1355
1356 kfree(buf);
1357 if (err < 0)
1358 return err;
1359
1360 *ppos += cnt;
1361
1362 return cnt;
1363}
1364
1365static LIST_HEAD(event_subsystems);
1366
1367static int subsystem_open(struct inode *inode, struct file *filp)
1368{
1369 struct event_subsystem *system = NULL;
1370 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1371 struct trace_array *tr;
1372 int ret;
1373
1374 if (tracing_is_disabled())
1375 return -ENODEV;
1376
1377 /* Make sure the system still exists */
1378 mutex_lock(&trace_types_lock);
1379 mutex_lock(&event_mutex);
1380 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1381 list_for_each_entry(dir, &tr->systems, list) {
1382 if (dir == inode->i_private) {
1383 /* Don't open systems with no events */
1384 if (dir->nr_events) {
1385 __get_system_dir(dir);
1386 system = dir->subsystem;
1387 }
1388 goto exit_loop;
1389 }
1390 }
1391 }
1392 exit_loop:
1393 mutex_unlock(&event_mutex);
1394 mutex_unlock(&trace_types_lock);
1395
1396 if (!system)
1397 return -ENODEV;
1398
1399 /* Some versions of gcc think dir can be uninitialized here */
1400 WARN_ON(!dir);
1401
1402 /* Still need to increment the ref count of the system */
1403 if (trace_array_get(tr) < 0) {
1404 put_system(dir);
1405 return -ENODEV;
1406 }
1407
1408 ret = tracing_open_generic(inode, filp);
1409 if (ret < 0) {
1410 trace_array_put(tr);
1411 put_system(dir);
1412 }
1413
1414 return ret;
1415}
1416
1417static int system_tr_open(struct inode *inode, struct file *filp)
1418{
1419 struct trace_subsystem_dir *dir;
1420 struct trace_array *tr = inode->i_private;
1421 int ret;
1422
1423 if (tracing_is_disabled())
1424 return -ENODEV;
1425
1426 if (trace_array_get(tr) < 0)
1427 return -ENODEV;
1428
1429 /* Make a temporary dir that has no system but points to tr */
1430 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1431 if (!dir) {
1432 trace_array_put(tr);
1433 return -ENOMEM;
1434 }
1435
1436 dir->tr = tr;
1437
1438 ret = tracing_open_generic(inode, filp);
1439 if (ret < 0) {
1440 trace_array_put(tr);
1441 kfree(dir);
1442 return ret;
1443 }
1444
1445 filp->private_data = dir;
1446
1447 return 0;
1448}
1449
1450static int subsystem_release(struct inode *inode, struct file *file)
1451{
1452 struct trace_subsystem_dir *dir = file->private_data;
1453
1454 trace_array_put(dir->tr);
1455
1456 /*
1457 * If dir->subsystem is NULL, then this is a temporary
1458 * descriptor that was made for a trace_array to enable
1459 * all subsystems.
1460 */
1461 if (dir->subsystem)
1462 put_system(dir);
1463 else
1464 kfree(dir);
1465
1466 return 0;
1467}
1468
1469static ssize_t
1470subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1471 loff_t *ppos)
1472{
1473 struct trace_subsystem_dir *dir = filp->private_data;
1474 struct event_subsystem *system = dir->subsystem;
1475 struct trace_seq *s;
1476 int r;
1477
1478 if (*ppos)
1479 return 0;
1480
1481 s = kmalloc(sizeof(*s), GFP_KERNEL);
1482 if (!s)
1483 return -ENOMEM;
1484
1485 trace_seq_init(s);
1486
1487 print_subsystem_event_filter(system, s);
1488 r = simple_read_from_buffer(ubuf, cnt, ppos,
1489 s->buffer, trace_seq_used(s));
1490
1491 kfree(s);
1492
1493 return r;
1494}
1495
1496static ssize_t
1497subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1498 loff_t *ppos)
1499{
1500 struct trace_subsystem_dir *dir = filp->private_data;
1501 char *buf;
1502 int err;
1503
1504 if (cnt >= PAGE_SIZE)
1505 return -EINVAL;
1506
1507 buf = memdup_user_nul(ubuf, cnt);
1508 if (IS_ERR(buf))
1509 return PTR_ERR(buf);
1510
1511 err = apply_subsystem_event_filter(dir, buf);
1512 kfree(buf);
1513 if (err < 0)
1514 return err;
1515
1516 *ppos += cnt;
1517
1518 return cnt;
1519}
1520
1521static ssize_t
1522show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1523{
1524 int (*func)(struct trace_seq *s) = filp->private_data;
1525 struct trace_seq *s;
1526 int r;
1527
1528 if (*ppos)
1529 return 0;
1530
1531 s = kmalloc(sizeof(*s), GFP_KERNEL);
1532 if (!s)
1533 return -ENOMEM;
1534
1535 trace_seq_init(s);
1536
1537 func(s);
1538 r = simple_read_from_buffer(ubuf, cnt, ppos,
1539 s->buffer, trace_seq_used(s));
1540
1541 kfree(s);
1542
1543 return r;
1544}
1545
1546static int max_pids(struct trace_pid_list *pid_list)
1547{
1548 return (PAGE_SIZE << pid_list->order) / sizeof(pid_t);
1549}
1550
1551static void ignore_task_cpu(void *data)
1552{
1553 struct trace_array *tr = data;
1554 struct trace_pid_list *pid_list;
1555
1556 /*
1557 * This function is called by on_each_cpu() while the
1558 * event_mutex is held.
1559 */
1560 pid_list = rcu_dereference_protected(tr->filtered_pids,
1561 mutex_is_locked(&event_mutex));
1562
1563 this_cpu_write(tr->trace_buffer.data->ignore_pid,
1564 check_ignore_pid(pid_list, current));
1565}
1566
1567static ssize_t
1568ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1569 size_t cnt, loff_t *ppos)
1570{
1571 struct seq_file *m = filp->private_data;
1572 struct trace_array *tr = m->private;
1573 struct trace_pid_list *filtered_pids = NULL;
1574 struct trace_pid_list *pid_list = NULL;
1575 struct trace_event_file *file;
1576 struct trace_parser parser;
1577 unsigned long val;
1578 loff_t this_pos;
1579 ssize_t read = 0;
1580 ssize_t ret = 0;
1581 pid_t pid;
1582 int i;
1583
1584 if (!cnt)
1585 return 0;
1586
1587 ret = tracing_update_buffers();
1588 if (ret < 0)
1589 return ret;
1590
1591 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
1592 return -ENOMEM;
1593
1594 mutex_lock(&event_mutex);
1595 /*
1596 * Load as many pids into the array before doing a
1597 * swap from the tr->filtered_pids to the new list.
1598 */
1599 while (cnt > 0) {
1600
1601 this_pos = 0;
1602
1603 ret = trace_get_user(&parser, ubuf, cnt, &this_pos);
1604 if (ret < 0 || !trace_parser_loaded(&parser))
1605 break;
1606
1607 read += ret;
1608 ubuf += ret;
1609 cnt -= ret;
1610
1611 parser.buffer[parser.idx] = 0;
1612
1613 ret = -EINVAL;
1614 if (kstrtoul(parser.buffer, 0, &val))
1615 break;
1616 if (val > INT_MAX)
1617 break;
1618
1619 pid = (pid_t)val;
1620
1621 ret = -ENOMEM;
1622 if (!pid_list) {
1623 pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL);
1624 if (!pid_list)
1625 break;
1626
1627 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1628 lockdep_is_held(&event_mutex));
1629 if (filtered_pids)
1630 pid_list->order = filtered_pids->order;
1631 else
1632 pid_list->order = 0;
1633
1634 pid_list->pids = (void *)__get_free_pages(GFP_KERNEL,
1635 pid_list->order);
1636 if (!pid_list->pids)
1637 break;
1638
1639 if (filtered_pids) {
1640 pid_list->nr_pids = filtered_pids->nr_pids;
1641 memcpy(pid_list->pids, filtered_pids->pids,
1642 pid_list->nr_pids * sizeof(pid_t));
1643 } else
1644 pid_list->nr_pids = 0;
1645 }
1646
1647 if (pid_list->nr_pids >= max_pids(pid_list)) {
1648 pid_t *pid_page;
1649
1650 pid_page = (void *)__get_free_pages(GFP_KERNEL,
1651 pid_list->order + 1);
1652 if (!pid_page)
1653 break;
1654 memcpy(pid_page, pid_list->pids,
1655 pid_list->nr_pids * sizeof(pid_t));
1656 free_pages((unsigned long)pid_list->pids, pid_list->order);
1657
1658 pid_list->order++;
1659 pid_list->pids = pid_page;
1660 }
1661
1662 pid_list->pids[pid_list->nr_pids++] = pid;
1663 trace_parser_clear(&parser);
1664 ret = 0;
1665 }
1666 trace_parser_put(&parser);
1667
1668 if (ret < 0) {
1669 if (pid_list)
1670 free_pages((unsigned long)pid_list->pids, pid_list->order);
1671 kfree(pid_list);
1672 mutex_unlock(&event_mutex);
1673 return ret;
1674 }
1675
1676 if (!pid_list) {
1677 mutex_unlock(&event_mutex);
1678 return ret;
1679 }
1680
1681 sort(pid_list->pids, pid_list->nr_pids, sizeof(pid_t), cmp_pid, NULL);
1682
1683 /* Remove duplicates */
1684 for (i = 1; i < pid_list->nr_pids; i++) {
1685 int start = i;
1686
1687 while (i < pid_list->nr_pids &&
1688 pid_list->pids[i - 1] == pid_list->pids[i])
1689 i++;
1690
1691 if (start != i) {
1692 if (i < pid_list->nr_pids) {
1693 memmove(&pid_list->pids[start], &pid_list->pids[i],
1694 (pid_list->nr_pids - i) * sizeof(pid_t));
1695 pid_list->nr_pids -= i - start;
1696 i = start;
1697 } else
1698 pid_list->nr_pids = start;
1699 }
1700 }
1701
1702 rcu_assign_pointer(tr->filtered_pids, pid_list);
1703
1704 list_for_each_entry(file, &tr->events, list) {
1705 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1706 }
1707
1708 if (filtered_pids) {
1709 synchronize_sched();
1710
1711 free_pages((unsigned long)filtered_pids->pids, filtered_pids->order);
1712 kfree(filtered_pids);
1713 } else {
1714 /*
1715 * Register a probe that is called before all other probes
1716 * to set ignore_pid if next or prev do not match.
1717 * Register a probe this is called after all other probes
1718 * to only keep ignore_pid set if next pid matches.
1719 */
1720 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1721 tr, INT_MAX);
1722 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1723 tr, 0);
1724
1725 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1726 tr, INT_MAX);
1727 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1728 tr, 0);
1729
1730 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1731 tr, INT_MAX);
1732 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1733 tr, 0);
1734
1735 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1736 tr, INT_MAX);
1737 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1738 tr, 0);
1739 }
1740
1741 /*
1742 * Ignoring of pids is done at task switch. But we have to
1743 * check for those tasks that are currently running.
1744 * Always do this in case a pid was appended or removed.
1745 */
1746 on_each_cpu(ignore_task_cpu, tr, 1);
1747
1748 mutex_unlock(&event_mutex);
1749
1750 ret = read;
1751 *ppos += read;
1752
1753 return ret;
1754}
1755
1756static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1757static int ftrace_event_set_open(struct inode *inode, struct file *file);
1758static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
1759static int ftrace_event_release(struct inode *inode, struct file *file);
1760
1761static const struct seq_operations show_event_seq_ops = {
1762 .start = t_start,
1763 .next = t_next,
1764 .show = t_show,
1765 .stop = t_stop,
1766};
1767
1768static const struct seq_operations show_set_event_seq_ops = {
1769 .start = s_start,
1770 .next = s_next,
1771 .show = t_show,
1772 .stop = t_stop,
1773};
1774
1775static const struct seq_operations show_set_pid_seq_ops = {
1776 .start = p_start,
1777 .next = p_next,
1778 .show = p_show,
1779 .stop = p_stop,
1780};
1781
1782static const struct file_operations ftrace_avail_fops = {
1783 .open = ftrace_event_avail_open,
1784 .read = seq_read,
1785 .llseek = seq_lseek,
1786 .release = seq_release,
1787};
1788
1789static const struct file_operations ftrace_set_event_fops = {
1790 .open = ftrace_event_set_open,
1791 .read = seq_read,
1792 .write = ftrace_event_write,
1793 .llseek = seq_lseek,
1794 .release = ftrace_event_release,
1795};
1796
1797static const struct file_operations ftrace_set_event_pid_fops = {
1798 .open = ftrace_event_set_pid_open,
1799 .read = seq_read,
1800 .write = ftrace_event_pid_write,
1801 .llseek = seq_lseek,
1802 .release = ftrace_event_release,
1803};
1804
1805static const struct file_operations ftrace_enable_fops = {
1806 .open = tracing_open_generic,
1807 .read = event_enable_read,
1808 .write = event_enable_write,
1809 .llseek = default_llseek,
1810};
1811
1812static const struct file_operations ftrace_event_format_fops = {
1813 .open = trace_format_open,
1814 .read = seq_read,
1815 .llseek = seq_lseek,
1816 .release = seq_release,
1817};
1818
1819static const struct file_operations ftrace_event_id_fops = {
1820 .read = event_id_read,
1821 .llseek = default_llseek,
1822};
1823
1824static const struct file_operations ftrace_event_filter_fops = {
1825 .open = tracing_open_generic,
1826 .read = event_filter_read,
1827 .write = event_filter_write,
1828 .llseek = default_llseek,
1829};
1830
1831static const struct file_operations ftrace_subsystem_filter_fops = {
1832 .open = subsystem_open,
1833 .read = subsystem_filter_read,
1834 .write = subsystem_filter_write,
1835 .llseek = default_llseek,
1836 .release = subsystem_release,
1837};
1838
1839static const struct file_operations ftrace_system_enable_fops = {
1840 .open = subsystem_open,
1841 .read = system_enable_read,
1842 .write = system_enable_write,
1843 .llseek = default_llseek,
1844 .release = subsystem_release,
1845};
1846
1847static const struct file_operations ftrace_tr_enable_fops = {
1848 .open = system_tr_open,
1849 .read = system_enable_read,
1850 .write = system_enable_write,
1851 .llseek = default_llseek,
1852 .release = subsystem_release,
1853};
1854
1855static const struct file_operations ftrace_show_header_fops = {
1856 .open = tracing_open_generic,
1857 .read = show_header,
1858 .llseek = default_llseek,
1859};
1860
1861static int
1862ftrace_event_open(struct inode *inode, struct file *file,
1863 const struct seq_operations *seq_ops)
1864{
1865 struct seq_file *m;
1866 int ret;
1867
1868 ret = seq_open(file, seq_ops);
1869 if (ret < 0)
1870 return ret;
1871 m = file->private_data;
1872 /* copy tr over to seq ops */
1873 m->private = inode->i_private;
1874
1875 return ret;
1876}
1877
1878static int ftrace_event_release(struct inode *inode, struct file *file)
1879{
1880 struct trace_array *tr = inode->i_private;
1881
1882 trace_array_put(tr);
1883
1884 return seq_release(inode, file);
1885}
1886
1887static int
1888ftrace_event_avail_open(struct inode *inode, struct file *file)
1889{
1890 const struct seq_operations *seq_ops = &show_event_seq_ops;
1891
1892 return ftrace_event_open(inode, file, seq_ops);
1893}
1894
1895static int
1896ftrace_event_set_open(struct inode *inode, struct file *file)
1897{
1898 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1899 struct trace_array *tr = inode->i_private;
1900 int ret;
1901
1902 if (trace_array_get(tr) < 0)
1903 return -ENODEV;
1904
1905 if ((file->f_mode & FMODE_WRITE) &&
1906 (file->f_flags & O_TRUNC))
1907 ftrace_clear_events(tr);
1908
1909 ret = ftrace_event_open(inode, file, seq_ops);
1910 if (ret < 0)
1911 trace_array_put(tr);
1912 return ret;
1913}
1914
1915static int
1916ftrace_event_set_pid_open(struct inode *inode, struct file *file)
1917{
1918 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
1919 struct trace_array *tr = inode->i_private;
1920 int ret;
1921
1922 if (trace_array_get(tr) < 0)
1923 return -ENODEV;
1924
1925 if ((file->f_mode & FMODE_WRITE) &&
1926 (file->f_flags & O_TRUNC))
1927 ftrace_clear_event_pids(tr);
1928
1929 ret = ftrace_event_open(inode, file, seq_ops);
1930 if (ret < 0)
1931 trace_array_put(tr);
1932 return ret;
1933}
1934
1935static struct event_subsystem *
1936create_new_subsystem(const char *name)
1937{
1938 struct event_subsystem *system;
1939
1940 /* need to create new entry */
1941 system = kmalloc(sizeof(*system), GFP_KERNEL);
1942 if (!system)
1943 return NULL;
1944
1945 system->ref_count = 1;
1946
1947 /* Only allocate if dynamic (kprobes and modules) */
1948 system->name = kstrdup_const(name, GFP_KERNEL);
1949 if (!system->name)
1950 goto out_free;
1951
1952 system->filter = NULL;
1953
1954 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1955 if (!system->filter)
1956 goto out_free;
1957
1958 list_add(&system->list, &event_subsystems);
1959
1960 return system;
1961
1962 out_free:
1963 kfree_const(system->name);
1964 kfree(system);
1965 return NULL;
1966}
1967
1968static struct dentry *
1969event_subsystem_dir(struct trace_array *tr, const char *name,
1970 struct trace_event_file *file, struct dentry *parent)
1971{
1972 struct trace_subsystem_dir *dir;
1973 struct event_subsystem *system;
1974 struct dentry *entry;
1975
1976 /* First see if we did not already create this dir */
1977 list_for_each_entry(dir, &tr->systems, list) {
1978 system = dir->subsystem;
1979 if (strcmp(system->name, name) == 0) {
1980 dir->nr_events++;
1981 file->system = dir;
1982 return dir->entry;
1983 }
1984 }
1985
1986 /* Now see if the system itself exists. */
1987 list_for_each_entry(system, &event_subsystems, list) {
1988 if (strcmp(system->name, name) == 0)
1989 break;
1990 }
1991 /* Reset system variable when not found */
1992 if (&system->list == &event_subsystems)
1993 system = NULL;
1994
1995 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1996 if (!dir)
1997 goto out_fail;
1998
1999 if (!system) {
2000 system = create_new_subsystem(name);
2001 if (!system)
2002 goto out_free;
2003 } else
2004 __get_system(system);
2005
2006 dir->entry = tracefs_create_dir(name, parent);
2007 if (!dir->entry) {
2008 pr_warn("Failed to create system directory %s\n", name);
2009 __put_system(system);
2010 goto out_free;
2011 }
2012
2013 dir->tr = tr;
2014 dir->ref_count = 1;
2015 dir->nr_events = 1;
2016 dir->subsystem = system;
2017 file->system = dir;
2018
2019 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
2020 &ftrace_subsystem_filter_fops);
2021 if (!entry) {
2022 kfree(system->filter);
2023 system->filter = NULL;
2024 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
2025 }
2026
2027 trace_create_file("enable", 0644, dir->entry, dir,
2028 &ftrace_system_enable_fops);
2029
2030 list_add(&dir->list, &tr->systems);
2031
2032 return dir->entry;
2033
2034 out_free:
2035 kfree(dir);
2036 out_fail:
2037 /* Only print this message if failed on memory allocation */
2038 if (!dir || !system)
2039 pr_warn("No memory to create event subsystem %s\n", name);
2040 return NULL;
2041}
2042
2043static int
2044event_create_dir(struct dentry *parent, struct trace_event_file *file)
2045{
2046 struct trace_event_call *call = file->event_call;
2047 struct trace_array *tr = file->tr;
2048 struct list_head *head;
2049 struct dentry *d_events;
2050 const char *name;
2051 int ret;
2052
2053 /*
2054 * If the trace point header did not define TRACE_SYSTEM
2055 * then the system would be called "TRACE_SYSTEM".
2056 */
2057 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
2058 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
2059 if (!d_events)
2060 return -ENOMEM;
2061 } else
2062 d_events = parent;
2063
2064 name = trace_event_name(call);
2065 file->dir = tracefs_create_dir(name, d_events);
2066 if (!file->dir) {
2067 pr_warn("Could not create tracefs '%s' directory\n", name);
2068 return -1;
2069 }
2070
2071 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2072 trace_create_file("enable", 0644, file->dir, file,
2073 &ftrace_enable_fops);
2074
2075#ifdef CONFIG_PERF_EVENTS
2076 if (call->event.type && call->class->reg)
2077 trace_create_file("id", 0444, file->dir,
2078 (void *)(long)call->event.type,
2079 &ftrace_event_id_fops);
2080#endif
2081
2082 /*
2083 * Other events may have the same class. Only update
2084 * the fields if they are not already defined.
2085 */
2086 head = trace_get_fields(call);
2087 if (list_empty(head)) {
2088 ret = call->class->define_fields(call);
2089 if (ret < 0) {
2090 pr_warn("Could not initialize trace point events/%s\n",
2091 name);
2092 return -1;
2093 }
2094 }
2095 trace_create_file("filter", 0644, file->dir, file,
2096 &ftrace_event_filter_fops);
2097
2098 /*
2099 * Only event directories that can be enabled should have
2100 * triggers.
2101 */
2102 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2103 trace_create_file("trigger", 0644, file->dir, file,
2104 &event_trigger_fops);
2105
2106 trace_create_file("format", 0444, file->dir, call,
2107 &ftrace_event_format_fops);
2108
2109 return 0;
2110}
2111
2112static void remove_event_from_tracers(struct trace_event_call *call)
2113{
2114 struct trace_event_file *file;
2115 struct trace_array *tr;
2116
2117 do_for_each_event_file_safe(tr, file) {
2118 if (file->event_call != call)
2119 continue;
2120
2121 remove_event_file_dir(file);
2122 /*
2123 * The do_for_each_event_file_safe() is
2124 * a double loop. After finding the call for this
2125 * trace_array, we use break to jump to the next
2126 * trace_array.
2127 */
2128 break;
2129 } while_for_each_event_file();
2130}
2131
2132static void event_remove(struct trace_event_call *call)
2133{
2134 struct trace_array *tr;
2135 struct trace_event_file *file;
2136
2137 do_for_each_event_file(tr, file) {
2138 if (file->event_call != call)
2139 continue;
2140 ftrace_event_enable_disable(file, 0);
2141 /*
2142 * The do_for_each_event_file() is
2143 * a double loop. After finding the call for this
2144 * trace_array, we use break to jump to the next
2145 * trace_array.
2146 */
2147 break;
2148 } while_for_each_event_file();
2149
2150 if (call->event.funcs)
2151 __unregister_trace_event(&call->event);
2152 remove_event_from_tracers(call);
2153 list_del(&call->list);
2154}
2155
2156static int event_init(struct trace_event_call *call)
2157{
2158 int ret = 0;
2159 const char *name;
2160
2161 name = trace_event_name(call);
2162 if (WARN_ON(!name))
2163 return -EINVAL;
2164
2165 if (call->class->raw_init) {
2166 ret = call->class->raw_init(call);
2167 if (ret < 0 && ret != -ENOSYS)
2168 pr_warn("Could not initialize trace events/%s\n", name);
2169 }
2170
2171 return ret;
2172}
2173
2174static int
2175__register_event(struct trace_event_call *call, struct module *mod)
2176{
2177 int ret;
2178
2179 ret = event_init(call);
2180 if (ret < 0)
2181 return ret;
2182
2183 list_add(&call->list, &ftrace_events);
2184 call->mod = mod;
2185
2186 return 0;
2187}
2188
2189static char *enum_replace(char *ptr, struct trace_enum_map *map, int len)
2190{
2191 int rlen;
2192 int elen;
2193
2194 /* Find the length of the enum value as a string */
2195 elen = snprintf(ptr, 0, "%ld", map->enum_value);
2196 /* Make sure there's enough room to replace the string with the value */
2197 if (len < elen)
2198 return NULL;
2199
2200 snprintf(ptr, elen + 1, "%ld", map->enum_value);
2201
2202 /* Get the rest of the string of ptr */
2203 rlen = strlen(ptr + len);
2204 memmove(ptr + elen, ptr + len, rlen);
2205 /* Make sure we end the new string */
2206 ptr[elen + rlen] = 0;
2207
2208 return ptr + elen;
2209}
2210
2211static void update_event_printk(struct trace_event_call *call,
2212 struct trace_enum_map *map)
2213{
2214 char *ptr;
2215 int quote = 0;
2216 int len = strlen(map->enum_string);
2217
2218 for (ptr = call->print_fmt; *ptr; ptr++) {
2219 if (*ptr == '\\') {
2220 ptr++;
2221 /* paranoid */
2222 if (!*ptr)
2223 break;
2224 continue;
2225 }
2226 if (*ptr == '"') {
2227 quote ^= 1;
2228 continue;
2229 }
2230 if (quote)
2231 continue;
2232 if (isdigit(*ptr)) {
2233 /* skip numbers */
2234 do {
2235 ptr++;
2236 /* Check for alpha chars like ULL */
2237 } while (isalnum(*ptr));
2238 if (!*ptr)
2239 break;
2240 /*
2241 * A number must have some kind of delimiter after
2242 * it, and we can ignore that too.
2243 */
2244 continue;
2245 }
2246 if (isalpha(*ptr) || *ptr == '_') {
2247 if (strncmp(map->enum_string, ptr, len) == 0 &&
2248 !isalnum(ptr[len]) && ptr[len] != '_') {
2249 ptr = enum_replace(ptr, map, len);
2250 /* Hmm, enum string smaller than value */
2251 if (WARN_ON_ONCE(!ptr))
2252 return;
2253 /*
2254 * No need to decrement here, as enum_replace()
2255 * returns the pointer to the character passed
2256 * the enum, and two enums can not be placed
2257 * back to back without something in between.
2258 * We can skip that something in between.
2259 */
2260 continue;
2261 }
2262 skip_more:
2263 do {
2264 ptr++;
2265 } while (isalnum(*ptr) || *ptr == '_');
2266 if (!*ptr)
2267 break;
2268 /*
2269 * If what comes after this variable is a '.' or
2270 * '->' then we can continue to ignore that string.
2271 */
2272 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2273 ptr += *ptr == '.' ? 1 : 2;
2274 if (!*ptr)
2275 break;
2276 goto skip_more;
2277 }
2278 /*
2279 * Once again, we can skip the delimiter that came
2280 * after the string.
2281 */
2282 continue;
2283 }
2284 }
2285}
2286
2287void trace_event_enum_update(struct trace_enum_map **map, int len)
2288{
2289 struct trace_event_call *call, *p;
2290 const char *last_system = NULL;
2291 int last_i;
2292 int i;
2293
2294 down_write(&trace_event_sem);
2295 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2296 /* events are usually grouped together with systems */
2297 if (!last_system || call->class->system != last_system) {
2298 last_i = 0;
2299 last_system = call->class->system;
2300 }
2301
2302 for (i = last_i; i < len; i++) {
2303 if (call->class->system == map[i]->system) {
2304 /* Save the first system if need be */
2305 if (!last_i)
2306 last_i = i;
2307 update_event_printk(call, map[i]);
2308 }
2309 }
2310 }
2311 up_write(&trace_event_sem);
2312}
2313
2314static struct trace_event_file *
2315trace_create_new_event(struct trace_event_call *call,
2316 struct trace_array *tr)
2317{
2318 struct trace_event_file *file;
2319
2320 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2321 if (!file)
2322 return NULL;
2323
2324 file->event_call = call;
2325 file->tr = tr;
2326 atomic_set(&file->sm_ref, 0);
2327 atomic_set(&file->tm_ref, 0);
2328 INIT_LIST_HEAD(&file->triggers);
2329 list_add(&file->list, &tr->events);
2330
2331 return file;
2332}
2333
2334/* Add an event to a trace directory */
2335static int
2336__trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2337{
2338 struct trace_event_file *file;
2339
2340 file = trace_create_new_event(call, tr);
2341 if (!file)
2342 return -ENOMEM;
2343
2344 return event_create_dir(tr->event_dir, file);
2345}
2346
2347/*
2348 * Just create a decriptor for early init. A descriptor is required
2349 * for enabling events at boot. We want to enable events before
2350 * the filesystem is initialized.
2351 */
2352static __init int
2353__trace_early_add_new_event(struct trace_event_call *call,
2354 struct trace_array *tr)
2355{
2356 struct trace_event_file *file;
2357
2358 file = trace_create_new_event(call, tr);
2359 if (!file)
2360 return -ENOMEM;
2361
2362 return 0;
2363}
2364
2365struct ftrace_module_file_ops;
2366static void __add_event_to_tracers(struct trace_event_call *call);
2367
2368/* Add an additional event_call dynamically */
2369int trace_add_event_call(struct trace_event_call *call)
2370{
2371 int ret;
2372 mutex_lock(&trace_types_lock);
2373 mutex_lock(&event_mutex);
2374
2375 ret = __register_event(call, NULL);
2376 if (ret >= 0)
2377 __add_event_to_tracers(call);
2378
2379 mutex_unlock(&event_mutex);
2380 mutex_unlock(&trace_types_lock);
2381 return ret;
2382}
2383
2384/*
2385 * Must be called under locking of trace_types_lock, event_mutex and
2386 * trace_event_sem.
2387 */
2388static void __trace_remove_event_call(struct trace_event_call *call)
2389{
2390 event_remove(call);
2391 trace_destroy_fields(call);
2392 free_event_filter(call->filter);
2393 call->filter = NULL;
2394}
2395
2396static int probe_remove_event_call(struct trace_event_call *call)
2397{
2398 struct trace_array *tr;
2399 struct trace_event_file *file;
2400
2401#ifdef CONFIG_PERF_EVENTS
2402 if (call->perf_refcount)
2403 return -EBUSY;
2404#endif
2405 do_for_each_event_file(tr, file) {
2406 if (file->event_call != call)
2407 continue;
2408 /*
2409 * We can't rely on ftrace_event_enable_disable(enable => 0)
2410 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2411 * TRACE_REG_UNREGISTER.
2412 */
2413 if (file->flags & EVENT_FILE_FL_ENABLED)
2414 return -EBUSY;
2415 /*
2416 * The do_for_each_event_file_safe() is
2417 * a double loop. After finding the call for this
2418 * trace_array, we use break to jump to the next
2419 * trace_array.
2420 */
2421 break;
2422 } while_for_each_event_file();
2423
2424 __trace_remove_event_call(call);
2425
2426 return 0;
2427}
2428
2429/* Remove an event_call */
2430int trace_remove_event_call(struct trace_event_call *call)
2431{
2432 int ret;
2433
2434 mutex_lock(&trace_types_lock);
2435 mutex_lock(&event_mutex);
2436 down_write(&trace_event_sem);
2437 ret = probe_remove_event_call(call);
2438 up_write(&trace_event_sem);
2439 mutex_unlock(&event_mutex);
2440 mutex_unlock(&trace_types_lock);
2441
2442 return ret;
2443}
2444
2445#define for_each_event(event, start, end) \
2446 for (event = start; \
2447 (unsigned long)event < (unsigned long)end; \
2448 event++)
2449
2450#ifdef CONFIG_MODULES
2451
2452static void trace_module_add_events(struct module *mod)
2453{
2454 struct trace_event_call **call, **start, **end;
2455
2456 if (!mod->num_trace_events)
2457 return;
2458
2459 /* Don't add infrastructure for mods without tracepoints */
2460 if (trace_module_has_bad_taint(mod)) {
2461 pr_err("%s: module has bad taint, not creating trace events\n",
2462 mod->name);
2463 return;
2464 }
2465
2466 start = mod->trace_events;
2467 end = mod->trace_events + mod->num_trace_events;
2468
2469 for_each_event(call, start, end) {
2470 __register_event(*call, mod);
2471 __add_event_to_tracers(*call);
2472 }
2473}
2474
2475static void trace_module_remove_events(struct module *mod)
2476{
2477 struct trace_event_call *call, *p;
2478 bool clear_trace = false;
2479
2480 down_write(&trace_event_sem);
2481 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2482 if (call->mod == mod) {
2483 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
2484 clear_trace = true;
2485 __trace_remove_event_call(call);
2486 }
2487 }
2488 up_write(&trace_event_sem);
2489
2490 /*
2491 * It is safest to reset the ring buffer if the module being unloaded
2492 * registered any events that were used. The only worry is if
2493 * a new module gets loaded, and takes on the same id as the events
2494 * of this module. When printing out the buffer, traced events left
2495 * over from this module may be passed to the new module events and
2496 * unexpected results may occur.
2497 */
2498 if (clear_trace)
2499 tracing_reset_all_online_cpus();
2500}
2501
2502static int trace_module_notify(struct notifier_block *self,
2503 unsigned long val, void *data)
2504{
2505 struct module *mod = data;
2506
2507 mutex_lock(&trace_types_lock);
2508 mutex_lock(&event_mutex);
2509 switch (val) {
2510 case MODULE_STATE_COMING:
2511 trace_module_add_events(mod);
2512 break;
2513 case MODULE_STATE_GOING:
2514 trace_module_remove_events(mod);
2515 break;
2516 }
2517 mutex_unlock(&event_mutex);
2518 mutex_unlock(&trace_types_lock);
2519
2520 return 0;
2521}
2522
2523static struct notifier_block trace_module_nb = {
2524 .notifier_call = trace_module_notify,
2525 .priority = 1, /* higher than trace.c module notify */
2526};
2527#endif /* CONFIG_MODULES */
2528
2529/* Create a new event directory structure for a trace directory. */
2530static void
2531__trace_add_event_dirs(struct trace_array *tr)
2532{
2533 struct trace_event_call *call;
2534 int ret;
2535
2536 list_for_each_entry(call, &ftrace_events, list) {
2537 ret = __trace_add_new_event(call, tr);
2538 if (ret < 0)
2539 pr_warn("Could not create directory for event %s\n",
2540 trace_event_name(call));
2541 }
2542}
2543
2544struct trace_event_file *
2545find_event_file(struct trace_array *tr, const char *system, const char *event)
2546{
2547 struct trace_event_file *file;
2548 struct trace_event_call *call;
2549 const char *name;
2550
2551 list_for_each_entry(file, &tr->events, list) {
2552
2553 call = file->event_call;
2554 name = trace_event_name(call);
2555
2556 if (!name || !call->class || !call->class->reg)
2557 continue;
2558
2559 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2560 continue;
2561
2562 if (strcmp(event, name) == 0 &&
2563 strcmp(system, call->class->system) == 0)
2564 return file;
2565 }
2566 return NULL;
2567}
2568
2569#ifdef CONFIG_DYNAMIC_FTRACE
2570
2571/* Avoid typos */
2572#define ENABLE_EVENT_STR "enable_event"
2573#define DISABLE_EVENT_STR "disable_event"
2574
2575struct event_probe_data {
2576 struct trace_event_file *file;
2577 unsigned long count;
2578 int ref;
2579 bool enable;
2580};
2581
2582static void
2583event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2584{
2585 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2586 struct event_probe_data *data = *pdata;
2587
2588 if (!data)
2589 return;
2590
2591 if (data->enable)
2592 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2593 else
2594 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2595}
2596
2597static void
2598event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2599{
2600 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2601 struct event_probe_data *data = *pdata;
2602
2603 if (!data)
2604 return;
2605
2606 if (!data->count)
2607 return;
2608
2609 /* Skip if the event is in a state we want to switch to */
2610 if (data->enable == !(data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
2611 return;
2612
2613 if (data->count != -1)
2614 (data->count)--;
2615
2616 event_enable_probe(ip, parent_ip, _data);
2617}
2618
2619static int
2620event_enable_print(struct seq_file *m, unsigned long ip,
2621 struct ftrace_probe_ops *ops, void *_data)
2622{
2623 struct event_probe_data *data = _data;
2624
2625 seq_printf(m, "%ps:", (void *)ip);
2626
2627 seq_printf(m, "%s:%s:%s",
2628 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2629 data->file->event_call->class->system,
2630 trace_event_name(data->file->event_call));
2631
2632 if (data->count == -1)
2633 seq_puts(m, ":unlimited\n");
2634 else
2635 seq_printf(m, ":count=%ld\n", data->count);
2636
2637 return 0;
2638}
2639
2640static int
2641event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
2642 void **_data)
2643{
2644 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2645 struct event_probe_data *data = *pdata;
2646
2647 data->ref++;
2648 return 0;
2649}
2650
2651static void
2652event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
2653 void **_data)
2654{
2655 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2656 struct event_probe_data *data = *pdata;
2657
2658 if (WARN_ON_ONCE(data->ref <= 0))
2659 return;
2660
2661 data->ref--;
2662 if (!data->ref) {
2663 /* Remove the SOFT_MODE flag */
2664 __ftrace_event_enable_disable(data->file, 0, 1);
2665 module_put(data->file->event_call->mod);
2666 kfree(data);
2667 }
2668 *pdata = NULL;
2669}
2670
2671static struct ftrace_probe_ops event_enable_probe_ops = {
2672 .func = event_enable_probe,
2673 .print = event_enable_print,
2674 .init = event_enable_init,
2675 .free = event_enable_free,
2676};
2677
2678static struct ftrace_probe_ops event_enable_count_probe_ops = {
2679 .func = event_enable_count_probe,
2680 .print = event_enable_print,
2681 .init = event_enable_init,
2682 .free = event_enable_free,
2683};
2684
2685static struct ftrace_probe_ops event_disable_probe_ops = {
2686 .func = event_enable_probe,
2687 .print = event_enable_print,
2688 .init = event_enable_init,
2689 .free = event_enable_free,
2690};
2691
2692static struct ftrace_probe_ops event_disable_count_probe_ops = {
2693 .func = event_enable_count_probe,
2694 .print = event_enable_print,
2695 .init = event_enable_init,
2696 .free = event_enable_free,
2697};
2698
2699static int
2700event_enable_func(struct ftrace_hash *hash,
2701 char *glob, char *cmd, char *param, int enabled)
2702{
2703 struct trace_array *tr = top_trace_array();
2704 struct trace_event_file *file;
2705 struct ftrace_probe_ops *ops;
2706 struct event_probe_data *data;
2707 const char *system;
2708 const char *event;
2709 char *number;
2710 bool enable;
2711 int ret;
2712
2713 if (!tr)
2714 return -ENODEV;
2715
2716 /* hash funcs only work with set_ftrace_filter */
2717 if (!enabled || !param)
2718 return -EINVAL;
2719
2720 system = strsep(¶m, ":");
2721 if (!param)
2722 return -EINVAL;
2723
2724 event = strsep(¶m, ":");
2725
2726 mutex_lock(&event_mutex);
2727
2728 ret = -EINVAL;
2729 file = find_event_file(tr, system, event);
2730 if (!file)
2731 goto out;
2732
2733 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2734
2735 if (enable)
2736 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2737 else
2738 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2739
2740 if (glob[0] == '!') {
2741 unregister_ftrace_function_probe_func(glob+1, ops);
2742 ret = 0;
2743 goto out;
2744 }
2745
2746 ret = -ENOMEM;
2747 data = kzalloc(sizeof(*data), GFP_KERNEL);
2748 if (!data)
2749 goto out;
2750
2751 data->enable = enable;
2752 data->count = -1;
2753 data->file = file;
2754
2755 if (!param)
2756 goto out_reg;
2757
2758 number = strsep(¶m, ":");
2759
2760 ret = -EINVAL;
2761 if (!strlen(number))
2762 goto out_free;
2763
2764 /*
2765 * We use the callback data field (which is a pointer)
2766 * as our counter.
2767 */
2768 ret = kstrtoul(number, 0, &data->count);
2769 if (ret)
2770 goto out_free;
2771
2772 out_reg:
2773 /* Don't let event modules unload while probe registered */
2774 ret = try_module_get(file->event_call->mod);
2775 if (!ret) {
2776 ret = -EBUSY;
2777 goto out_free;
2778 }
2779
2780 ret = __ftrace_event_enable_disable(file, 1, 1);
2781 if (ret < 0)
2782 goto out_put;
2783 ret = register_ftrace_function_probe(glob, ops, data);
2784 /*
2785 * The above returns on success the # of functions enabled,
2786 * but if it didn't find any functions it returns zero.
2787 * Consider no functions a failure too.
2788 */
2789 if (!ret) {
2790 ret = -ENOENT;
2791 goto out_disable;
2792 } else if (ret < 0)
2793 goto out_disable;
2794 /* Just return zero, not the number of enabled functions */
2795 ret = 0;
2796 out:
2797 mutex_unlock(&event_mutex);
2798 return ret;
2799
2800 out_disable:
2801 __ftrace_event_enable_disable(file, 0, 1);
2802 out_put:
2803 module_put(file->event_call->mod);
2804 out_free:
2805 kfree(data);
2806 goto out;
2807}
2808
2809static struct ftrace_func_command event_enable_cmd = {
2810 .name = ENABLE_EVENT_STR,
2811 .func = event_enable_func,
2812};
2813
2814static struct ftrace_func_command event_disable_cmd = {
2815 .name = DISABLE_EVENT_STR,
2816 .func = event_enable_func,
2817};
2818
2819static __init int register_event_cmds(void)
2820{
2821 int ret;
2822
2823 ret = register_ftrace_command(&event_enable_cmd);
2824 if (WARN_ON(ret < 0))
2825 return ret;
2826 ret = register_ftrace_command(&event_disable_cmd);
2827 if (WARN_ON(ret < 0))
2828 unregister_ftrace_command(&event_enable_cmd);
2829 return ret;
2830}
2831#else
2832static inline int register_event_cmds(void) { return 0; }
2833#endif /* CONFIG_DYNAMIC_FTRACE */
2834
2835/*
2836 * The top level array has already had its trace_event_file
2837 * descriptors created in order to allow for early events to
2838 * be recorded. This function is called after the tracefs has been
2839 * initialized, and we now have to create the files associated
2840 * to the events.
2841 */
2842static __init void
2843__trace_early_add_event_dirs(struct trace_array *tr)
2844{
2845 struct trace_event_file *file;
2846 int ret;
2847
2848
2849 list_for_each_entry(file, &tr->events, list) {
2850 ret = event_create_dir(tr->event_dir, file);
2851 if (ret < 0)
2852 pr_warn("Could not create directory for event %s\n",
2853 trace_event_name(file->event_call));
2854 }
2855}
2856
2857/*
2858 * For early boot up, the top trace array requires to have
2859 * a list of events that can be enabled. This must be done before
2860 * the filesystem is set up in order to allow events to be traced
2861 * early.
2862 */
2863static __init void
2864__trace_early_add_events(struct trace_array *tr)
2865{
2866 struct trace_event_call *call;
2867 int ret;
2868
2869 list_for_each_entry(call, &ftrace_events, list) {
2870 /* Early boot up should not have any modules loaded */
2871 if (WARN_ON_ONCE(call->mod))
2872 continue;
2873
2874 ret = __trace_early_add_new_event(call, tr);
2875 if (ret < 0)
2876 pr_warn("Could not create early event %s\n",
2877 trace_event_name(call));
2878 }
2879}
2880
2881/* Remove the event directory structure for a trace directory. */
2882static void
2883__trace_remove_event_dirs(struct trace_array *tr)
2884{
2885 struct trace_event_file *file, *next;
2886
2887 list_for_each_entry_safe(file, next, &tr->events, list)
2888 remove_event_file_dir(file);
2889}
2890
2891static void __add_event_to_tracers(struct trace_event_call *call)
2892{
2893 struct trace_array *tr;
2894
2895 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2896 __trace_add_new_event(call, tr);
2897}
2898
2899extern struct trace_event_call *__start_ftrace_events[];
2900extern struct trace_event_call *__stop_ftrace_events[];
2901
2902static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2903
2904static __init int setup_trace_event(char *str)
2905{
2906 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2907 ring_buffer_expanded = true;
2908 tracing_selftest_disabled = true;
2909
2910 return 1;
2911}
2912__setup("trace_event=", setup_trace_event);
2913
2914/* Expects to have event_mutex held when called */
2915static int
2916create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2917{
2918 struct dentry *d_events;
2919 struct dentry *entry;
2920
2921 entry = tracefs_create_file("set_event", 0644, parent,
2922 tr, &ftrace_set_event_fops);
2923 if (!entry) {
2924 pr_warn("Could not create tracefs 'set_event' entry\n");
2925 return -ENOMEM;
2926 }
2927
2928 d_events = tracefs_create_dir("events", parent);
2929 if (!d_events) {
2930 pr_warn("Could not create tracefs 'events' directory\n");
2931 return -ENOMEM;
2932 }
2933
2934 entry = tracefs_create_file("set_event_pid", 0644, parent,
2935 tr, &ftrace_set_event_pid_fops);
2936
2937 /* ring buffer internal formats */
2938 trace_create_file("header_page", 0444, d_events,
2939 ring_buffer_print_page_header,
2940 &ftrace_show_header_fops);
2941
2942 trace_create_file("header_event", 0444, d_events,
2943 ring_buffer_print_entry_header,
2944 &ftrace_show_header_fops);
2945
2946 trace_create_file("enable", 0644, d_events,
2947 tr, &ftrace_tr_enable_fops);
2948
2949 tr->event_dir = d_events;
2950
2951 return 0;
2952}
2953
2954/**
2955 * event_trace_add_tracer - add a instance of a trace_array to events
2956 * @parent: The parent dentry to place the files/directories for events in
2957 * @tr: The trace array associated with these events
2958 *
2959 * When a new instance is created, it needs to set up its events
2960 * directory, as well as other files associated with events. It also
2961 * creates the event hierachry in the @parent/events directory.
2962 *
2963 * Returns 0 on success.
2964 */
2965int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2966{
2967 int ret;
2968
2969 mutex_lock(&event_mutex);
2970
2971 ret = create_event_toplevel_files(parent, tr);
2972 if (ret)
2973 goto out_unlock;
2974
2975 down_write(&trace_event_sem);
2976 __trace_add_event_dirs(tr);
2977 up_write(&trace_event_sem);
2978
2979 out_unlock:
2980 mutex_unlock(&event_mutex);
2981
2982 return ret;
2983}
2984
2985/*
2986 * The top trace array already had its file descriptors created.
2987 * Now the files themselves need to be created.
2988 */
2989static __init int
2990early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2991{
2992 int ret;
2993
2994 mutex_lock(&event_mutex);
2995
2996 ret = create_event_toplevel_files(parent, tr);
2997 if (ret)
2998 goto out_unlock;
2999
3000 down_write(&trace_event_sem);
3001 __trace_early_add_event_dirs(tr);
3002 up_write(&trace_event_sem);
3003
3004 out_unlock:
3005 mutex_unlock(&event_mutex);
3006
3007 return ret;
3008}
3009
3010int event_trace_del_tracer(struct trace_array *tr)
3011{
3012 mutex_lock(&event_mutex);
3013
3014 /* Disable any event triggers and associated soft-disabled events */
3015 clear_event_triggers(tr);
3016
3017 /* Clear the pid list */
3018 __ftrace_clear_event_pids(tr);
3019
3020 /* Disable any running events */
3021 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3022
3023 /* Access to events are within rcu_read_lock_sched() */
3024 synchronize_sched();
3025
3026 down_write(&trace_event_sem);
3027 __trace_remove_event_dirs(tr);
3028 tracefs_remove_recursive(tr->event_dir);
3029 up_write(&trace_event_sem);
3030
3031 tr->event_dir = NULL;
3032
3033 mutex_unlock(&event_mutex);
3034
3035 return 0;
3036}
3037
3038static __init int event_trace_memsetup(void)
3039{
3040 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3041 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3042 return 0;
3043}
3044
3045static __init void
3046early_enable_events(struct trace_array *tr, bool disable_first)
3047{
3048 char *buf = bootup_event_buf;
3049 char *token;
3050 int ret;
3051
3052 while (true) {
3053 token = strsep(&buf, ",");
3054
3055 if (!token)
3056 break;
3057
3058 if (*token) {
3059 /* Restarting syscalls requires that we stop them first */
3060 if (disable_first)
3061 ftrace_set_clr_event(tr, token, 0);
3062
3063 ret = ftrace_set_clr_event(tr, token, 1);
3064 if (ret)
3065 pr_warn("Failed to enable trace event: %s\n", token);
3066 }
3067
3068 /* Put back the comma to allow this to be called again */
3069 if (buf)
3070 *(buf - 1) = ',';
3071 }
3072}
3073
3074static __init int event_trace_enable(void)
3075{
3076 struct trace_array *tr = top_trace_array();
3077 struct trace_event_call **iter, *call;
3078 int ret;
3079
3080 if (!tr)
3081 return -ENODEV;
3082
3083 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3084
3085 call = *iter;
3086 ret = event_init(call);
3087 if (!ret)
3088 list_add(&call->list, &ftrace_events);
3089 }
3090
3091 /*
3092 * We need the top trace array to have a working set of trace
3093 * points at early init, before the debug files and directories
3094 * are created. Create the file entries now, and attach them
3095 * to the actual file dentries later.
3096 */
3097 __trace_early_add_events(tr);
3098
3099 early_enable_events(tr, false);
3100
3101 trace_printk_start_comm();
3102
3103 register_event_cmds();
3104
3105 register_trigger_cmds();
3106
3107 return 0;
3108}
3109
3110/*
3111 * event_trace_enable() is called from trace_event_init() first to
3112 * initialize events and perhaps start any events that are on the
3113 * command line. Unfortunately, there are some events that will not
3114 * start this early, like the system call tracepoints that need
3115 * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
3116 * is called before pid 1 starts, and this flag is never set, making
3117 * the syscall tracepoint never get reached, but the event is enabled
3118 * regardless (and not doing anything).
3119 */
3120static __init int event_trace_enable_again(void)
3121{
3122 struct trace_array *tr;
3123
3124 tr = top_trace_array();
3125 if (!tr)
3126 return -ENODEV;
3127
3128 early_enable_events(tr, true);
3129
3130 return 0;
3131}
3132
3133early_initcall(event_trace_enable_again);
3134
3135static __init int event_trace_init(void)
3136{
3137 struct trace_array *tr;
3138 struct dentry *d_tracer;
3139 struct dentry *entry;
3140 int ret;
3141
3142 tr = top_trace_array();
3143 if (!tr)
3144 return -ENODEV;
3145
3146 d_tracer = tracing_init_dentry();
3147 if (IS_ERR(d_tracer))
3148 return 0;
3149
3150 entry = tracefs_create_file("available_events", 0444, d_tracer,
3151 tr, &ftrace_avail_fops);
3152 if (!entry)
3153 pr_warn("Could not create tracefs 'available_events' entry\n");
3154
3155 if (trace_define_generic_fields())
3156 pr_warn("tracing: Failed to allocated generic fields");
3157
3158 if (trace_define_common_fields())
3159 pr_warn("tracing: Failed to allocate common fields");
3160
3161 ret = early_event_add_tracer(d_tracer, tr);
3162 if (ret)
3163 return ret;
3164
3165#ifdef CONFIG_MODULES
3166 ret = register_module_notifier(&trace_module_nb);
3167 if (ret)
3168 pr_warn("Failed to register trace events module notifier\n");
3169#endif
3170 return 0;
3171}
3172
3173void __init trace_event_init(void)
3174{
3175 event_trace_memsetup();
3176 init_ftrace_syscalls();
3177 event_trace_enable();
3178}
3179
3180fs_initcall(event_trace_init);
3181
3182#ifdef CONFIG_FTRACE_STARTUP_TEST
3183
3184static DEFINE_SPINLOCK(test_spinlock);
3185static DEFINE_SPINLOCK(test_spinlock_irq);
3186static DEFINE_MUTEX(test_mutex);
3187
3188static __init void test_work(struct work_struct *dummy)
3189{
3190 spin_lock(&test_spinlock);
3191 spin_lock_irq(&test_spinlock_irq);
3192 udelay(1);
3193 spin_unlock_irq(&test_spinlock_irq);
3194 spin_unlock(&test_spinlock);
3195
3196 mutex_lock(&test_mutex);
3197 msleep(1);
3198 mutex_unlock(&test_mutex);
3199}
3200
3201static __init int event_test_thread(void *unused)
3202{
3203 void *test_malloc;
3204
3205 test_malloc = kmalloc(1234, GFP_KERNEL);
3206 if (!test_malloc)
3207 pr_info("failed to kmalloc\n");
3208
3209 schedule_on_each_cpu(test_work);
3210
3211 kfree(test_malloc);
3212
3213 set_current_state(TASK_INTERRUPTIBLE);
3214 while (!kthread_should_stop()) {
3215 schedule();
3216 set_current_state(TASK_INTERRUPTIBLE);
3217 }
3218 __set_current_state(TASK_RUNNING);
3219
3220 return 0;
3221}
3222
3223/*
3224 * Do various things that may trigger events.
3225 */
3226static __init void event_test_stuff(void)
3227{
3228 struct task_struct *test_thread;
3229
3230 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3231 msleep(1);
3232 kthread_stop(test_thread);
3233}
3234
3235/*
3236 * For every trace event defined, we will test each trace point separately,
3237 * and then by groups, and finally all trace points.
3238 */
3239static __init void event_trace_self_tests(void)
3240{
3241 struct trace_subsystem_dir *dir;
3242 struct trace_event_file *file;
3243 struct trace_event_call *call;
3244 struct event_subsystem *system;
3245 struct trace_array *tr;
3246 int ret;
3247
3248 tr = top_trace_array();
3249 if (!tr)
3250 return;
3251
3252 pr_info("Running tests on trace events:\n");
3253
3254 list_for_each_entry(file, &tr->events, list) {
3255
3256 call = file->event_call;
3257
3258 /* Only test those that have a probe */
3259 if (!call->class || !call->class->probe)
3260 continue;
3261
3262/*
3263 * Testing syscall events here is pretty useless, but
3264 * we still do it if configured. But this is time consuming.
3265 * What we really need is a user thread to perform the
3266 * syscalls as we test.
3267 */
3268#ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3269 if (call->class->system &&
3270 strcmp(call->class->system, "syscalls") == 0)
3271 continue;
3272#endif
3273
3274 pr_info("Testing event %s: ", trace_event_name(call));
3275
3276 /*
3277 * If an event is already enabled, someone is using
3278 * it and the self test should not be on.
3279 */
3280 if (file->flags & EVENT_FILE_FL_ENABLED) {
3281 pr_warn("Enabled event during self test!\n");
3282 WARN_ON_ONCE(1);
3283 continue;
3284 }
3285
3286 ftrace_event_enable_disable(file, 1);
3287 event_test_stuff();
3288 ftrace_event_enable_disable(file, 0);
3289
3290 pr_cont("OK\n");
3291 }
3292
3293 /* Now test at the sub system level */
3294
3295 pr_info("Running tests on trace event systems:\n");
3296
3297 list_for_each_entry(dir, &tr->systems, list) {
3298
3299 system = dir->subsystem;
3300
3301 /* the ftrace system is special, skip it */
3302 if (strcmp(system->name, "ftrace") == 0)
3303 continue;
3304
3305 pr_info("Testing event system %s: ", system->name);
3306
3307 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3308 if (WARN_ON_ONCE(ret)) {
3309 pr_warn("error enabling system %s\n",
3310 system->name);
3311 continue;
3312 }
3313
3314 event_test_stuff();
3315
3316 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3317 if (WARN_ON_ONCE(ret)) {
3318 pr_warn("error disabling system %s\n",
3319 system->name);
3320 continue;
3321 }
3322
3323 pr_cont("OK\n");
3324 }
3325
3326 /* Test with all events enabled */
3327
3328 pr_info("Running tests on all trace events:\n");
3329 pr_info("Testing all events: ");
3330
3331 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3332 if (WARN_ON_ONCE(ret)) {
3333 pr_warn("error enabling all events\n");
3334 return;
3335 }
3336
3337 event_test_stuff();
3338
3339 /* reset sysname */
3340 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3341 if (WARN_ON_ONCE(ret)) {
3342 pr_warn("error disabling all events\n");
3343 return;
3344 }
3345
3346 pr_cont("OK\n");
3347}
3348
3349#ifdef CONFIG_FUNCTION_TRACER
3350
3351static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3352
3353static struct trace_array *event_tr;
3354
3355static void __init
3356function_test_events_call(unsigned long ip, unsigned long parent_ip,
3357 struct ftrace_ops *op, struct pt_regs *pt_regs)
3358{
3359 struct ring_buffer_event *event;
3360 struct ring_buffer *buffer;
3361 struct ftrace_entry *entry;
3362 unsigned long flags;
3363 long disabled;
3364 int cpu;
3365 int pc;
3366
3367 pc = preempt_count();
3368 preempt_disable_notrace();
3369 cpu = raw_smp_processor_id();
3370 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3371
3372 if (disabled != 1)
3373 goto out;
3374
3375 local_save_flags(flags);
3376
3377 event = trace_current_buffer_lock_reserve(&buffer,
3378 TRACE_FN, sizeof(*entry),
3379 flags, pc);
3380 if (!event)
3381 goto out;
3382 entry = ring_buffer_event_data(event);
3383 entry->ip = ip;
3384 entry->parent_ip = parent_ip;
3385
3386 trace_buffer_unlock_commit(event_tr, buffer, event, flags, pc);
3387
3388 out:
3389 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3390 preempt_enable_notrace();
3391}
3392
3393static struct ftrace_ops trace_ops __initdata =
3394{
3395 .func = function_test_events_call,
3396 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
3397};
3398
3399static __init void event_trace_self_test_with_function(void)
3400{
3401 int ret;
3402 event_tr = top_trace_array();
3403 if (WARN_ON(!event_tr))
3404 return;
3405 ret = register_ftrace_function(&trace_ops);
3406 if (WARN_ON(ret < 0)) {
3407 pr_info("Failed to enable function tracer for event tests\n");
3408 return;
3409 }
3410 pr_info("Running tests again, along with the function tracer\n");
3411 event_trace_self_tests();
3412 unregister_ftrace_function(&trace_ops);
3413}
3414#else
3415static __init void event_trace_self_test_with_function(void)
3416{
3417}
3418#endif
3419
3420static __init int event_trace_self_tests_init(void)
3421{
3422 if (!tracing_selftest_disabled) {
3423 event_trace_self_tests();
3424 event_trace_self_test_with_function();
3425 }
3426
3427 return 0;
3428}
3429
3430late_initcall(event_trace_self_tests_init);
3431
3432#endif
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * event tracer
4 *
5 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
6 *
7 * - Added format output of fields of the trace point.
8 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
9 *
10 */
11
12#define pr_fmt(fmt) fmt
13
14#include <linux/workqueue.h>
15#include <linux/security.h>
16#include <linux/spinlock.h>
17#include <linux/kthread.h>
18#include <linux/tracefs.h>
19#include <linux/uaccess.h>
20#include <linux/module.h>
21#include <linux/ctype.h>
22#include <linux/sort.h>
23#include <linux/slab.h>
24#include <linux/delay.h>
25
26#include <trace/events/sched.h>
27#include <trace/syscall.h>
28
29#include <asm/setup.h>
30
31#include "trace_output.h"
32
33#undef TRACE_SYSTEM
34#define TRACE_SYSTEM "TRACE_SYSTEM"
35
36DEFINE_MUTEX(event_mutex);
37
38LIST_HEAD(ftrace_events);
39static LIST_HEAD(ftrace_generic_fields);
40static LIST_HEAD(ftrace_common_fields);
41
42#define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
43
44static struct kmem_cache *field_cachep;
45static struct kmem_cache *file_cachep;
46
47static inline int system_refcount(struct event_subsystem *system)
48{
49 return system->ref_count;
50}
51
52static int system_refcount_inc(struct event_subsystem *system)
53{
54 return system->ref_count++;
55}
56
57static int system_refcount_dec(struct event_subsystem *system)
58{
59 return --system->ref_count;
60}
61
62/* Double loops, do not use break, only goto's work */
63#define do_for_each_event_file(tr, file) \
64 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
65 list_for_each_entry(file, &tr->events, list)
66
67#define do_for_each_event_file_safe(tr, file) \
68 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
69 struct trace_event_file *___n; \
70 list_for_each_entry_safe(file, ___n, &tr->events, list)
71
72#define while_for_each_event_file() \
73 }
74
75static struct ftrace_event_field *
76__find_event_field(struct list_head *head, char *name)
77{
78 struct ftrace_event_field *field;
79
80 list_for_each_entry(field, head, link) {
81 if (!strcmp(field->name, name))
82 return field;
83 }
84
85 return NULL;
86}
87
88struct ftrace_event_field *
89trace_find_event_field(struct trace_event_call *call, char *name)
90{
91 struct ftrace_event_field *field;
92 struct list_head *head;
93
94 head = trace_get_fields(call);
95 field = __find_event_field(head, name);
96 if (field)
97 return field;
98
99 field = __find_event_field(&ftrace_generic_fields, name);
100 if (field)
101 return field;
102
103 return __find_event_field(&ftrace_common_fields, name);
104}
105
106static int __trace_define_field(struct list_head *head, const char *type,
107 const char *name, int offset, int size,
108 int is_signed, int filter_type)
109{
110 struct ftrace_event_field *field;
111
112 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
113 if (!field)
114 return -ENOMEM;
115
116 field->name = name;
117 field->type = type;
118
119 if (filter_type == FILTER_OTHER)
120 field->filter_type = filter_assign_type(type);
121 else
122 field->filter_type = filter_type;
123
124 field->offset = offset;
125 field->size = size;
126 field->is_signed = is_signed;
127
128 list_add(&field->link, head);
129
130 return 0;
131}
132
133int trace_define_field(struct trace_event_call *call, const char *type,
134 const char *name, int offset, int size, int is_signed,
135 int filter_type)
136{
137 struct list_head *head;
138
139 if (WARN_ON(!call->class))
140 return 0;
141
142 head = trace_get_fields(call);
143 return __trace_define_field(head, type, name, offset, size,
144 is_signed, filter_type);
145}
146EXPORT_SYMBOL_GPL(trace_define_field);
147
148#define __generic_field(type, item, filter_type) \
149 ret = __trace_define_field(&ftrace_generic_fields, #type, \
150 #item, 0, 0, is_signed_type(type), \
151 filter_type); \
152 if (ret) \
153 return ret;
154
155#define __common_field(type, item) \
156 ret = __trace_define_field(&ftrace_common_fields, #type, \
157 "common_" #item, \
158 offsetof(typeof(ent), item), \
159 sizeof(ent.item), \
160 is_signed_type(type), FILTER_OTHER); \
161 if (ret) \
162 return ret;
163
164static int trace_define_generic_fields(void)
165{
166 int ret;
167
168 __generic_field(int, CPU, FILTER_CPU);
169 __generic_field(int, cpu, FILTER_CPU);
170 __generic_field(char *, COMM, FILTER_COMM);
171 __generic_field(char *, comm, FILTER_COMM);
172
173 return ret;
174}
175
176static int trace_define_common_fields(void)
177{
178 int ret;
179 struct trace_entry ent;
180
181 __common_field(unsigned short, type);
182 __common_field(unsigned char, flags);
183 __common_field(unsigned char, preempt_count);
184 __common_field(int, pid);
185
186 return ret;
187}
188
189static void trace_destroy_fields(struct trace_event_call *call)
190{
191 struct ftrace_event_field *field, *next;
192 struct list_head *head;
193
194 head = trace_get_fields(call);
195 list_for_each_entry_safe(field, next, head, link) {
196 list_del(&field->link);
197 kmem_cache_free(field_cachep, field);
198 }
199}
200
201/*
202 * run-time version of trace_event_get_offsets_<call>() that returns the last
203 * accessible offset of trace fields excluding __dynamic_array bytes
204 */
205int trace_event_get_offsets(struct trace_event_call *call)
206{
207 struct ftrace_event_field *tail;
208 struct list_head *head;
209
210 head = trace_get_fields(call);
211 /*
212 * head->next points to the last field with the largest offset,
213 * since it was added last by trace_define_field()
214 */
215 tail = list_first_entry(head, struct ftrace_event_field, link);
216 return tail->offset + tail->size;
217}
218
219int trace_event_raw_init(struct trace_event_call *call)
220{
221 int id;
222
223 id = register_trace_event(&call->event);
224 if (!id)
225 return -ENODEV;
226
227 return 0;
228}
229EXPORT_SYMBOL_GPL(trace_event_raw_init);
230
231bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
232{
233 struct trace_array *tr = trace_file->tr;
234 struct trace_array_cpu *data;
235 struct trace_pid_list *no_pid_list;
236 struct trace_pid_list *pid_list;
237
238 pid_list = rcu_dereference_raw(tr->filtered_pids);
239 no_pid_list = rcu_dereference_raw(tr->filtered_no_pids);
240
241 if (!pid_list && !no_pid_list)
242 return false;
243
244 data = this_cpu_ptr(tr->array_buffer.data);
245
246 return data->ignore_pid;
247}
248EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
249
250void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
251 struct trace_event_file *trace_file,
252 unsigned long len)
253{
254 struct trace_event_call *event_call = trace_file->event_call;
255
256 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
257 trace_event_ignore_this_pid(trace_file))
258 return NULL;
259
260 local_save_flags(fbuffer->flags);
261 fbuffer->pc = preempt_count();
262 /*
263 * If CONFIG_PREEMPTION is enabled, then the tracepoint itself disables
264 * preemption (adding one to the preempt_count). Since we are
265 * interested in the preempt_count at the time the tracepoint was
266 * hit, we need to subtract one to offset the increment.
267 */
268 if (IS_ENABLED(CONFIG_PREEMPTION))
269 fbuffer->pc--;
270 fbuffer->trace_file = trace_file;
271
272 fbuffer->event =
273 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
274 event_call->event.type, len,
275 fbuffer->flags, fbuffer->pc);
276 if (!fbuffer->event)
277 return NULL;
278
279 fbuffer->regs = NULL;
280 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
281 return fbuffer->entry;
282}
283EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
284
285int trace_event_reg(struct trace_event_call *call,
286 enum trace_reg type, void *data)
287{
288 struct trace_event_file *file = data;
289
290 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
291 switch (type) {
292 case TRACE_REG_REGISTER:
293 return tracepoint_probe_register(call->tp,
294 call->class->probe,
295 file);
296 case TRACE_REG_UNREGISTER:
297 tracepoint_probe_unregister(call->tp,
298 call->class->probe,
299 file);
300 return 0;
301
302#ifdef CONFIG_PERF_EVENTS
303 case TRACE_REG_PERF_REGISTER:
304 return tracepoint_probe_register(call->tp,
305 call->class->perf_probe,
306 call);
307 case TRACE_REG_PERF_UNREGISTER:
308 tracepoint_probe_unregister(call->tp,
309 call->class->perf_probe,
310 call);
311 return 0;
312 case TRACE_REG_PERF_OPEN:
313 case TRACE_REG_PERF_CLOSE:
314 case TRACE_REG_PERF_ADD:
315 case TRACE_REG_PERF_DEL:
316 return 0;
317#endif
318 }
319 return 0;
320}
321EXPORT_SYMBOL_GPL(trace_event_reg);
322
323void trace_event_enable_cmd_record(bool enable)
324{
325 struct trace_event_file *file;
326 struct trace_array *tr;
327
328 lockdep_assert_held(&event_mutex);
329
330 do_for_each_event_file(tr, file) {
331
332 if (!(file->flags & EVENT_FILE_FL_ENABLED))
333 continue;
334
335 if (enable) {
336 tracing_start_cmdline_record();
337 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
338 } else {
339 tracing_stop_cmdline_record();
340 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
341 }
342 } while_for_each_event_file();
343}
344
345void trace_event_enable_tgid_record(bool enable)
346{
347 struct trace_event_file *file;
348 struct trace_array *tr;
349
350 lockdep_assert_held(&event_mutex);
351
352 do_for_each_event_file(tr, file) {
353 if (!(file->flags & EVENT_FILE_FL_ENABLED))
354 continue;
355
356 if (enable) {
357 tracing_start_tgid_record();
358 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
359 } else {
360 tracing_stop_tgid_record();
361 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
362 &file->flags);
363 }
364 } while_for_each_event_file();
365}
366
367static int __ftrace_event_enable_disable(struct trace_event_file *file,
368 int enable, int soft_disable)
369{
370 struct trace_event_call *call = file->event_call;
371 struct trace_array *tr = file->tr;
372 unsigned long file_flags = file->flags;
373 int ret = 0;
374 int disable;
375
376 switch (enable) {
377 case 0:
378 /*
379 * When soft_disable is set and enable is cleared, the sm_ref
380 * reference counter is decremented. If it reaches 0, we want
381 * to clear the SOFT_DISABLED flag but leave the event in the
382 * state that it was. That is, if the event was enabled and
383 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
384 * is set we do not want the event to be enabled before we
385 * clear the bit.
386 *
387 * When soft_disable is not set but the SOFT_MODE flag is,
388 * we do nothing. Do not disable the tracepoint, otherwise
389 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
390 */
391 if (soft_disable) {
392 if (atomic_dec_return(&file->sm_ref) > 0)
393 break;
394 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
395 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
396 } else
397 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
398
399 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
400 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
401 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
402 tracing_stop_cmdline_record();
403 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
404 }
405
406 if (file->flags & EVENT_FILE_FL_RECORDED_TGID) {
407 tracing_stop_tgid_record();
408 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
409 }
410
411 call->class->reg(call, TRACE_REG_UNREGISTER, file);
412 }
413 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
414 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
415 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
416 else
417 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
418 break;
419 case 1:
420 /*
421 * When soft_disable is set and enable is set, we want to
422 * register the tracepoint for the event, but leave the event
423 * as is. That means, if the event was already enabled, we do
424 * nothing (but set SOFT_MODE). If the event is disabled, we
425 * set SOFT_DISABLED before enabling the event tracepoint, so
426 * it still seems to be disabled.
427 */
428 if (!soft_disable)
429 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
430 else {
431 if (atomic_inc_return(&file->sm_ref) > 1)
432 break;
433 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
434 }
435
436 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
437 bool cmd = false, tgid = false;
438
439 /* Keep the event disabled, when going to SOFT_MODE. */
440 if (soft_disable)
441 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
442
443 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
444 cmd = true;
445 tracing_start_cmdline_record();
446 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
447 }
448
449 if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
450 tgid = true;
451 tracing_start_tgid_record();
452 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
453 }
454
455 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
456 if (ret) {
457 if (cmd)
458 tracing_stop_cmdline_record();
459 if (tgid)
460 tracing_stop_tgid_record();
461 pr_info("event trace: Could not enable event "
462 "%s\n", trace_event_name(call));
463 break;
464 }
465 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
466
467 /* WAS_ENABLED gets set but never cleared. */
468 set_bit(EVENT_FILE_FL_WAS_ENABLED_BIT, &file->flags);
469 }
470 break;
471 }
472
473 /* Enable or disable use of trace_buffered_event */
474 if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) !=
475 (file->flags & EVENT_FILE_FL_SOFT_DISABLED)) {
476 if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
477 trace_buffered_event_enable();
478 else
479 trace_buffered_event_disable();
480 }
481
482 return ret;
483}
484
485int trace_event_enable_disable(struct trace_event_file *file,
486 int enable, int soft_disable)
487{
488 return __ftrace_event_enable_disable(file, enable, soft_disable);
489}
490
491static int ftrace_event_enable_disable(struct trace_event_file *file,
492 int enable)
493{
494 return __ftrace_event_enable_disable(file, enable, 0);
495}
496
497static void ftrace_clear_events(struct trace_array *tr)
498{
499 struct trace_event_file *file;
500
501 mutex_lock(&event_mutex);
502 list_for_each_entry(file, &tr->events, list) {
503 ftrace_event_enable_disable(file, 0);
504 }
505 mutex_unlock(&event_mutex);
506}
507
508static void
509event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
510{
511 struct trace_pid_list *pid_list;
512 struct trace_array *tr = data;
513
514 pid_list = rcu_dereference_raw(tr->filtered_pids);
515 trace_filter_add_remove_task(pid_list, NULL, task);
516
517 pid_list = rcu_dereference_raw(tr->filtered_no_pids);
518 trace_filter_add_remove_task(pid_list, NULL, task);
519}
520
521static void
522event_filter_pid_sched_process_fork(void *data,
523 struct task_struct *self,
524 struct task_struct *task)
525{
526 struct trace_pid_list *pid_list;
527 struct trace_array *tr = data;
528
529 pid_list = rcu_dereference_sched(tr->filtered_pids);
530 trace_filter_add_remove_task(pid_list, self, task);
531
532 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
533 trace_filter_add_remove_task(pid_list, self, task);
534}
535
536void trace_event_follow_fork(struct trace_array *tr, bool enable)
537{
538 if (enable) {
539 register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
540 tr, INT_MIN);
541 register_trace_prio_sched_process_free(event_filter_pid_sched_process_exit,
542 tr, INT_MAX);
543 } else {
544 unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
545 tr);
546 unregister_trace_sched_process_free(event_filter_pid_sched_process_exit,
547 tr);
548 }
549}
550
551static void
552event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
553 struct task_struct *prev, struct task_struct *next)
554{
555 struct trace_array *tr = data;
556 struct trace_pid_list *no_pid_list;
557 struct trace_pid_list *pid_list;
558 bool ret;
559
560 pid_list = rcu_dereference_sched(tr->filtered_pids);
561 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
562
563 /*
564 * Sched switch is funny, as we only want to ignore it
565 * in the notrace case if both prev and next should be ignored.
566 */
567 ret = trace_ignore_this_task(NULL, no_pid_list, prev) &&
568 trace_ignore_this_task(NULL, no_pid_list, next);
569
570 this_cpu_write(tr->array_buffer.data->ignore_pid, ret ||
571 (trace_ignore_this_task(pid_list, NULL, prev) &&
572 trace_ignore_this_task(pid_list, NULL, next)));
573}
574
575static void
576event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
577 struct task_struct *prev, struct task_struct *next)
578{
579 struct trace_array *tr = data;
580 struct trace_pid_list *no_pid_list;
581 struct trace_pid_list *pid_list;
582
583 pid_list = rcu_dereference_sched(tr->filtered_pids);
584 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
585
586 this_cpu_write(tr->array_buffer.data->ignore_pid,
587 trace_ignore_this_task(pid_list, no_pid_list, next));
588}
589
590static void
591event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
592{
593 struct trace_array *tr = data;
594 struct trace_pid_list *no_pid_list;
595 struct trace_pid_list *pid_list;
596
597 /* Nothing to do if we are already tracing */
598 if (!this_cpu_read(tr->array_buffer.data->ignore_pid))
599 return;
600
601 pid_list = rcu_dereference_sched(tr->filtered_pids);
602 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
603
604 this_cpu_write(tr->array_buffer.data->ignore_pid,
605 trace_ignore_this_task(pid_list, no_pid_list, task));
606}
607
608static void
609event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
610{
611 struct trace_array *tr = data;
612 struct trace_pid_list *no_pid_list;
613 struct trace_pid_list *pid_list;
614
615 /* Nothing to do if we are not tracing */
616 if (this_cpu_read(tr->array_buffer.data->ignore_pid))
617 return;
618
619 pid_list = rcu_dereference_sched(tr->filtered_pids);
620 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
621
622 /* Set tracing if current is enabled */
623 this_cpu_write(tr->array_buffer.data->ignore_pid,
624 trace_ignore_this_task(pid_list, no_pid_list, current));
625}
626
627static void unregister_pid_events(struct trace_array *tr)
628{
629 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
630 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
631
632 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
633 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
634
635 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
636 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
637
638 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
639 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
640}
641
642static void __ftrace_clear_event_pids(struct trace_array *tr, int type)
643{
644 struct trace_pid_list *pid_list;
645 struct trace_pid_list *no_pid_list;
646 struct trace_event_file *file;
647 int cpu;
648
649 pid_list = rcu_dereference_protected(tr->filtered_pids,
650 lockdep_is_held(&event_mutex));
651 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
652 lockdep_is_held(&event_mutex));
653
654 /* Make sure there's something to do */
655 if (!pid_type_enabled(type, pid_list, no_pid_list))
656 return;
657
658 if (!still_need_pid_events(type, pid_list, no_pid_list)) {
659 unregister_pid_events(tr);
660
661 list_for_each_entry(file, &tr->events, list) {
662 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
663 }
664
665 for_each_possible_cpu(cpu)
666 per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false;
667 }
668
669 if (type & TRACE_PIDS)
670 rcu_assign_pointer(tr->filtered_pids, NULL);
671
672 if (type & TRACE_NO_PIDS)
673 rcu_assign_pointer(tr->filtered_no_pids, NULL);
674
675 /* Wait till all users are no longer using pid filtering */
676 tracepoint_synchronize_unregister();
677
678 if ((type & TRACE_PIDS) && pid_list)
679 trace_free_pid_list(pid_list);
680
681 if ((type & TRACE_NO_PIDS) && no_pid_list)
682 trace_free_pid_list(no_pid_list);
683}
684
685static void ftrace_clear_event_pids(struct trace_array *tr, int type)
686{
687 mutex_lock(&event_mutex);
688 __ftrace_clear_event_pids(tr, type);
689 mutex_unlock(&event_mutex);
690}
691
692static void __put_system(struct event_subsystem *system)
693{
694 struct event_filter *filter = system->filter;
695
696 WARN_ON_ONCE(system_refcount(system) == 0);
697 if (system_refcount_dec(system))
698 return;
699
700 list_del(&system->list);
701
702 if (filter) {
703 kfree(filter->filter_string);
704 kfree(filter);
705 }
706 kfree_const(system->name);
707 kfree(system);
708}
709
710static void __get_system(struct event_subsystem *system)
711{
712 WARN_ON_ONCE(system_refcount(system) == 0);
713 system_refcount_inc(system);
714}
715
716static void __get_system_dir(struct trace_subsystem_dir *dir)
717{
718 WARN_ON_ONCE(dir->ref_count == 0);
719 dir->ref_count++;
720 __get_system(dir->subsystem);
721}
722
723static void __put_system_dir(struct trace_subsystem_dir *dir)
724{
725 WARN_ON_ONCE(dir->ref_count == 0);
726 /* If the subsystem is about to be freed, the dir must be too */
727 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
728
729 __put_system(dir->subsystem);
730 if (!--dir->ref_count)
731 kfree(dir);
732}
733
734static void put_system(struct trace_subsystem_dir *dir)
735{
736 mutex_lock(&event_mutex);
737 __put_system_dir(dir);
738 mutex_unlock(&event_mutex);
739}
740
741static void remove_subsystem(struct trace_subsystem_dir *dir)
742{
743 if (!dir)
744 return;
745
746 if (!--dir->nr_events) {
747 tracefs_remove(dir->entry);
748 list_del(&dir->list);
749 __put_system_dir(dir);
750 }
751}
752
753static void remove_event_file_dir(struct trace_event_file *file)
754{
755 struct dentry *dir = file->dir;
756 struct dentry *child;
757
758 if (dir) {
759 spin_lock(&dir->d_lock); /* probably unneeded */
760 list_for_each_entry(child, &dir->d_subdirs, d_child) {
761 if (d_really_is_positive(child)) /* probably unneeded */
762 d_inode(child)->i_private = NULL;
763 }
764 spin_unlock(&dir->d_lock);
765
766 tracefs_remove(dir);
767 }
768
769 list_del(&file->list);
770 remove_subsystem(file->system);
771 free_event_filter(file->filter);
772 kmem_cache_free(file_cachep, file);
773}
774
775/*
776 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
777 */
778static int
779__ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
780 const char *sub, const char *event, int set)
781{
782 struct trace_event_file *file;
783 struct trace_event_call *call;
784 const char *name;
785 int ret = -EINVAL;
786 int eret = 0;
787
788 list_for_each_entry(file, &tr->events, list) {
789
790 call = file->event_call;
791 name = trace_event_name(call);
792
793 if (!name || !call->class || !call->class->reg)
794 continue;
795
796 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
797 continue;
798
799 if (match &&
800 strcmp(match, name) != 0 &&
801 strcmp(match, call->class->system) != 0)
802 continue;
803
804 if (sub && strcmp(sub, call->class->system) != 0)
805 continue;
806
807 if (event && strcmp(event, name) != 0)
808 continue;
809
810 ret = ftrace_event_enable_disable(file, set);
811
812 /*
813 * Save the first error and return that. Some events
814 * may still have been enabled, but let the user
815 * know that something went wrong.
816 */
817 if (ret && !eret)
818 eret = ret;
819
820 ret = eret;
821 }
822
823 return ret;
824}
825
826static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
827 const char *sub, const char *event, int set)
828{
829 int ret;
830
831 mutex_lock(&event_mutex);
832 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
833 mutex_unlock(&event_mutex);
834
835 return ret;
836}
837
838int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
839{
840 char *event = NULL, *sub = NULL, *match;
841 int ret;
842
843 if (!tr)
844 return -ENOENT;
845 /*
846 * The buf format can be <subsystem>:<event-name>
847 * *:<event-name> means any event by that name.
848 * :<event-name> is the same.
849 *
850 * <subsystem>:* means all events in that subsystem
851 * <subsystem>: means the same.
852 *
853 * <name> (no ':') means all events in a subsystem with
854 * the name <name> or any event that matches <name>
855 */
856
857 match = strsep(&buf, ":");
858 if (buf) {
859 sub = match;
860 event = buf;
861 match = NULL;
862
863 if (!strlen(sub) || strcmp(sub, "*") == 0)
864 sub = NULL;
865 if (!strlen(event) || strcmp(event, "*") == 0)
866 event = NULL;
867 }
868
869 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
870
871 /* Put back the colon to allow this to be called again */
872 if (buf)
873 *(buf - 1) = ':';
874
875 return ret;
876}
877
878/**
879 * trace_set_clr_event - enable or disable an event
880 * @system: system name to match (NULL for any system)
881 * @event: event name to match (NULL for all events, within system)
882 * @set: 1 to enable, 0 to disable
883 *
884 * This is a way for other parts of the kernel to enable or disable
885 * event recording.
886 *
887 * Returns 0 on success, -EINVAL if the parameters do not match any
888 * registered events.
889 */
890int trace_set_clr_event(const char *system, const char *event, int set)
891{
892 struct trace_array *tr = top_trace_array();
893
894 if (!tr)
895 return -ENODEV;
896
897 return __ftrace_set_clr_event(tr, NULL, system, event, set);
898}
899EXPORT_SYMBOL_GPL(trace_set_clr_event);
900
901/**
902 * trace_array_set_clr_event - enable or disable an event for a trace array.
903 * @tr: concerned trace array.
904 * @system: system name to match (NULL for any system)
905 * @event: event name to match (NULL for all events, within system)
906 * @enable: true to enable, false to disable
907 *
908 * This is a way for other parts of the kernel to enable or disable
909 * event recording.
910 *
911 * Returns 0 on success, -EINVAL if the parameters do not match any
912 * registered events.
913 */
914int trace_array_set_clr_event(struct trace_array *tr, const char *system,
915 const char *event, bool enable)
916{
917 int set;
918
919 if (!tr)
920 return -ENOENT;
921
922 set = (enable == true) ? 1 : 0;
923 return __ftrace_set_clr_event(tr, NULL, system, event, set);
924}
925EXPORT_SYMBOL_GPL(trace_array_set_clr_event);
926
927/* 128 should be much more than enough */
928#define EVENT_BUF_SIZE 127
929
930static ssize_t
931ftrace_event_write(struct file *file, const char __user *ubuf,
932 size_t cnt, loff_t *ppos)
933{
934 struct trace_parser parser;
935 struct seq_file *m = file->private_data;
936 struct trace_array *tr = m->private;
937 ssize_t read, ret;
938
939 if (!cnt)
940 return 0;
941
942 ret = tracing_update_buffers();
943 if (ret < 0)
944 return ret;
945
946 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
947 return -ENOMEM;
948
949 read = trace_get_user(&parser, ubuf, cnt, ppos);
950
951 if (read >= 0 && trace_parser_loaded((&parser))) {
952 int set = 1;
953
954 if (*parser.buffer == '!')
955 set = 0;
956
957 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
958 if (ret)
959 goto out_put;
960 }
961
962 ret = read;
963
964 out_put:
965 trace_parser_put(&parser);
966
967 return ret;
968}
969
970static void *
971t_next(struct seq_file *m, void *v, loff_t *pos)
972{
973 struct trace_event_file *file = v;
974 struct trace_event_call *call;
975 struct trace_array *tr = m->private;
976
977 (*pos)++;
978
979 list_for_each_entry_continue(file, &tr->events, list) {
980 call = file->event_call;
981 /*
982 * The ftrace subsystem is for showing formats only.
983 * They can not be enabled or disabled via the event files.
984 */
985 if (call->class && call->class->reg &&
986 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
987 return file;
988 }
989
990 return NULL;
991}
992
993static void *t_start(struct seq_file *m, loff_t *pos)
994{
995 struct trace_event_file *file;
996 struct trace_array *tr = m->private;
997 loff_t l;
998
999 mutex_lock(&event_mutex);
1000
1001 file = list_entry(&tr->events, struct trace_event_file, list);
1002 for (l = 0; l <= *pos; ) {
1003 file = t_next(m, file, &l);
1004 if (!file)
1005 break;
1006 }
1007 return file;
1008}
1009
1010static void *
1011s_next(struct seq_file *m, void *v, loff_t *pos)
1012{
1013 struct trace_event_file *file = v;
1014 struct trace_array *tr = m->private;
1015
1016 (*pos)++;
1017
1018 list_for_each_entry_continue(file, &tr->events, list) {
1019 if (file->flags & EVENT_FILE_FL_ENABLED)
1020 return file;
1021 }
1022
1023 return NULL;
1024}
1025
1026static void *s_start(struct seq_file *m, loff_t *pos)
1027{
1028 struct trace_event_file *file;
1029 struct trace_array *tr = m->private;
1030 loff_t l;
1031
1032 mutex_lock(&event_mutex);
1033
1034 file = list_entry(&tr->events, struct trace_event_file, list);
1035 for (l = 0; l <= *pos; ) {
1036 file = s_next(m, file, &l);
1037 if (!file)
1038 break;
1039 }
1040 return file;
1041}
1042
1043static int t_show(struct seq_file *m, void *v)
1044{
1045 struct trace_event_file *file = v;
1046 struct trace_event_call *call = file->event_call;
1047
1048 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1049 seq_printf(m, "%s:", call->class->system);
1050 seq_printf(m, "%s\n", trace_event_name(call));
1051
1052 return 0;
1053}
1054
1055static void t_stop(struct seq_file *m, void *p)
1056{
1057 mutex_unlock(&event_mutex);
1058}
1059
1060static void *
1061__next(struct seq_file *m, void *v, loff_t *pos, int type)
1062{
1063 struct trace_array *tr = m->private;
1064 struct trace_pid_list *pid_list;
1065
1066 if (type == TRACE_PIDS)
1067 pid_list = rcu_dereference_sched(tr->filtered_pids);
1068 else
1069 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1070
1071 return trace_pid_next(pid_list, v, pos);
1072}
1073
1074static void *
1075p_next(struct seq_file *m, void *v, loff_t *pos)
1076{
1077 return __next(m, v, pos, TRACE_PIDS);
1078}
1079
1080static void *
1081np_next(struct seq_file *m, void *v, loff_t *pos)
1082{
1083 return __next(m, v, pos, TRACE_NO_PIDS);
1084}
1085
1086static void *__start(struct seq_file *m, loff_t *pos, int type)
1087 __acquires(RCU)
1088{
1089 struct trace_pid_list *pid_list;
1090 struct trace_array *tr = m->private;
1091
1092 /*
1093 * Grab the mutex, to keep calls to p_next() having the same
1094 * tr->filtered_pids as p_start() has.
1095 * If we just passed the tr->filtered_pids around, then RCU would
1096 * have been enough, but doing that makes things more complex.
1097 */
1098 mutex_lock(&event_mutex);
1099 rcu_read_lock_sched();
1100
1101 if (type == TRACE_PIDS)
1102 pid_list = rcu_dereference_sched(tr->filtered_pids);
1103 else
1104 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1105
1106 if (!pid_list)
1107 return NULL;
1108
1109 return trace_pid_start(pid_list, pos);
1110}
1111
1112static void *p_start(struct seq_file *m, loff_t *pos)
1113 __acquires(RCU)
1114{
1115 return __start(m, pos, TRACE_PIDS);
1116}
1117
1118static void *np_start(struct seq_file *m, loff_t *pos)
1119 __acquires(RCU)
1120{
1121 return __start(m, pos, TRACE_NO_PIDS);
1122}
1123
1124static void p_stop(struct seq_file *m, void *p)
1125 __releases(RCU)
1126{
1127 rcu_read_unlock_sched();
1128 mutex_unlock(&event_mutex);
1129}
1130
1131static ssize_t
1132event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1133 loff_t *ppos)
1134{
1135 struct trace_event_file *file;
1136 unsigned long flags;
1137 char buf[4] = "0";
1138
1139 mutex_lock(&event_mutex);
1140 file = event_file_data(filp);
1141 if (likely(file))
1142 flags = file->flags;
1143 mutex_unlock(&event_mutex);
1144
1145 if (!file)
1146 return -ENODEV;
1147
1148 if (flags & EVENT_FILE_FL_ENABLED &&
1149 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1150 strcpy(buf, "1");
1151
1152 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1153 flags & EVENT_FILE_FL_SOFT_MODE)
1154 strcat(buf, "*");
1155
1156 strcat(buf, "\n");
1157
1158 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1159}
1160
1161static ssize_t
1162event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1163 loff_t *ppos)
1164{
1165 struct trace_event_file *file;
1166 unsigned long val;
1167 int ret;
1168
1169 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1170 if (ret)
1171 return ret;
1172
1173 ret = tracing_update_buffers();
1174 if (ret < 0)
1175 return ret;
1176
1177 switch (val) {
1178 case 0:
1179 case 1:
1180 ret = -ENODEV;
1181 mutex_lock(&event_mutex);
1182 file = event_file_data(filp);
1183 if (likely(file))
1184 ret = ftrace_event_enable_disable(file, val);
1185 mutex_unlock(&event_mutex);
1186 break;
1187
1188 default:
1189 return -EINVAL;
1190 }
1191
1192 *ppos += cnt;
1193
1194 return ret ? ret : cnt;
1195}
1196
1197static ssize_t
1198system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1199 loff_t *ppos)
1200{
1201 const char set_to_char[4] = { '?', '0', '1', 'X' };
1202 struct trace_subsystem_dir *dir = filp->private_data;
1203 struct event_subsystem *system = dir->subsystem;
1204 struct trace_event_call *call;
1205 struct trace_event_file *file;
1206 struct trace_array *tr = dir->tr;
1207 char buf[2];
1208 int set = 0;
1209 int ret;
1210
1211 mutex_lock(&event_mutex);
1212 list_for_each_entry(file, &tr->events, list) {
1213 call = file->event_call;
1214 if (!trace_event_name(call) || !call->class || !call->class->reg)
1215 continue;
1216
1217 if (system && strcmp(call->class->system, system->name) != 0)
1218 continue;
1219
1220 /*
1221 * We need to find out if all the events are set
1222 * or if all events or cleared, or if we have
1223 * a mixture.
1224 */
1225 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1226
1227 /*
1228 * If we have a mixture, no need to look further.
1229 */
1230 if (set == 3)
1231 break;
1232 }
1233 mutex_unlock(&event_mutex);
1234
1235 buf[0] = set_to_char[set];
1236 buf[1] = '\n';
1237
1238 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1239
1240 return ret;
1241}
1242
1243static ssize_t
1244system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1245 loff_t *ppos)
1246{
1247 struct trace_subsystem_dir *dir = filp->private_data;
1248 struct event_subsystem *system = dir->subsystem;
1249 const char *name = NULL;
1250 unsigned long val;
1251 ssize_t ret;
1252
1253 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1254 if (ret)
1255 return ret;
1256
1257 ret = tracing_update_buffers();
1258 if (ret < 0)
1259 return ret;
1260
1261 if (val != 0 && val != 1)
1262 return -EINVAL;
1263
1264 /*
1265 * Opening of "enable" adds a ref count to system,
1266 * so the name is safe to use.
1267 */
1268 if (system)
1269 name = system->name;
1270
1271 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1272 if (ret)
1273 goto out;
1274
1275 ret = cnt;
1276
1277out:
1278 *ppos += cnt;
1279
1280 return ret;
1281}
1282
1283enum {
1284 FORMAT_HEADER = 1,
1285 FORMAT_FIELD_SEPERATOR = 2,
1286 FORMAT_PRINTFMT = 3,
1287};
1288
1289static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1290{
1291 struct trace_event_call *call = event_file_data(m->private);
1292 struct list_head *common_head = &ftrace_common_fields;
1293 struct list_head *head = trace_get_fields(call);
1294 struct list_head *node = v;
1295
1296 (*pos)++;
1297
1298 switch ((unsigned long)v) {
1299 case FORMAT_HEADER:
1300 node = common_head;
1301 break;
1302
1303 case FORMAT_FIELD_SEPERATOR:
1304 node = head;
1305 break;
1306
1307 case FORMAT_PRINTFMT:
1308 /* all done */
1309 return NULL;
1310 }
1311
1312 node = node->prev;
1313 if (node == common_head)
1314 return (void *)FORMAT_FIELD_SEPERATOR;
1315 else if (node == head)
1316 return (void *)FORMAT_PRINTFMT;
1317 else
1318 return node;
1319}
1320
1321static int f_show(struct seq_file *m, void *v)
1322{
1323 struct trace_event_call *call = event_file_data(m->private);
1324 struct ftrace_event_field *field;
1325 const char *array_descriptor;
1326
1327 switch ((unsigned long)v) {
1328 case FORMAT_HEADER:
1329 seq_printf(m, "name: %s\n", trace_event_name(call));
1330 seq_printf(m, "ID: %d\n", call->event.type);
1331 seq_puts(m, "format:\n");
1332 return 0;
1333
1334 case FORMAT_FIELD_SEPERATOR:
1335 seq_putc(m, '\n');
1336 return 0;
1337
1338 case FORMAT_PRINTFMT:
1339 seq_printf(m, "\nprint fmt: %s\n",
1340 call->print_fmt);
1341 return 0;
1342 }
1343
1344 field = list_entry(v, struct ftrace_event_field, link);
1345 /*
1346 * Smartly shows the array type(except dynamic array).
1347 * Normal:
1348 * field:TYPE VAR
1349 * If TYPE := TYPE[LEN], it is shown:
1350 * field:TYPE VAR[LEN]
1351 */
1352 array_descriptor = strchr(field->type, '[');
1353
1354 if (str_has_prefix(field->type, "__data_loc"))
1355 array_descriptor = NULL;
1356
1357 if (!array_descriptor)
1358 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1359 field->type, field->name, field->offset,
1360 field->size, !!field->is_signed);
1361 else
1362 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1363 (int)(array_descriptor - field->type),
1364 field->type, field->name,
1365 array_descriptor, field->offset,
1366 field->size, !!field->is_signed);
1367
1368 return 0;
1369}
1370
1371static void *f_start(struct seq_file *m, loff_t *pos)
1372{
1373 void *p = (void *)FORMAT_HEADER;
1374 loff_t l = 0;
1375
1376 /* ->stop() is called even if ->start() fails */
1377 mutex_lock(&event_mutex);
1378 if (!event_file_data(m->private))
1379 return ERR_PTR(-ENODEV);
1380
1381 while (l < *pos && p)
1382 p = f_next(m, p, &l);
1383
1384 return p;
1385}
1386
1387static void f_stop(struct seq_file *m, void *p)
1388{
1389 mutex_unlock(&event_mutex);
1390}
1391
1392static const struct seq_operations trace_format_seq_ops = {
1393 .start = f_start,
1394 .next = f_next,
1395 .stop = f_stop,
1396 .show = f_show,
1397};
1398
1399static int trace_format_open(struct inode *inode, struct file *file)
1400{
1401 struct seq_file *m;
1402 int ret;
1403
1404 /* Do we want to hide event format files on tracefs lockdown? */
1405
1406 ret = seq_open(file, &trace_format_seq_ops);
1407 if (ret < 0)
1408 return ret;
1409
1410 m = file->private_data;
1411 m->private = file;
1412
1413 return 0;
1414}
1415
1416static ssize_t
1417event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1418{
1419 int id = (long)event_file_data(filp);
1420 char buf[32];
1421 int len;
1422
1423 if (unlikely(!id))
1424 return -ENODEV;
1425
1426 len = sprintf(buf, "%d\n", id);
1427
1428 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1429}
1430
1431static ssize_t
1432event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1433 loff_t *ppos)
1434{
1435 struct trace_event_file *file;
1436 struct trace_seq *s;
1437 int r = -ENODEV;
1438
1439 if (*ppos)
1440 return 0;
1441
1442 s = kmalloc(sizeof(*s), GFP_KERNEL);
1443
1444 if (!s)
1445 return -ENOMEM;
1446
1447 trace_seq_init(s);
1448
1449 mutex_lock(&event_mutex);
1450 file = event_file_data(filp);
1451 if (file)
1452 print_event_filter(file, s);
1453 mutex_unlock(&event_mutex);
1454
1455 if (file)
1456 r = simple_read_from_buffer(ubuf, cnt, ppos,
1457 s->buffer, trace_seq_used(s));
1458
1459 kfree(s);
1460
1461 return r;
1462}
1463
1464static ssize_t
1465event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1466 loff_t *ppos)
1467{
1468 struct trace_event_file *file;
1469 char *buf;
1470 int err = -ENODEV;
1471
1472 if (cnt >= PAGE_SIZE)
1473 return -EINVAL;
1474
1475 buf = memdup_user_nul(ubuf, cnt);
1476 if (IS_ERR(buf))
1477 return PTR_ERR(buf);
1478
1479 mutex_lock(&event_mutex);
1480 file = event_file_data(filp);
1481 if (file)
1482 err = apply_event_filter(file, buf);
1483 mutex_unlock(&event_mutex);
1484
1485 kfree(buf);
1486 if (err < 0)
1487 return err;
1488
1489 *ppos += cnt;
1490
1491 return cnt;
1492}
1493
1494static LIST_HEAD(event_subsystems);
1495
1496static int subsystem_open(struct inode *inode, struct file *filp)
1497{
1498 struct event_subsystem *system = NULL;
1499 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1500 struct trace_array *tr;
1501 int ret;
1502
1503 if (tracing_is_disabled())
1504 return -ENODEV;
1505
1506 /* Make sure the system still exists */
1507 mutex_lock(&event_mutex);
1508 mutex_lock(&trace_types_lock);
1509 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1510 list_for_each_entry(dir, &tr->systems, list) {
1511 if (dir == inode->i_private) {
1512 /* Don't open systems with no events */
1513 if (dir->nr_events) {
1514 __get_system_dir(dir);
1515 system = dir->subsystem;
1516 }
1517 goto exit_loop;
1518 }
1519 }
1520 }
1521 exit_loop:
1522 mutex_unlock(&trace_types_lock);
1523 mutex_unlock(&event_mutex);
1524
1525 if (!system)
1526 return -ENODEV;
1527
1528 /* Some versions of gcc think dir can be uninitialized here */
1529 WARN_ON(!dir);
1530
1531 /* Still need to increment the ref count of the system */
1532 if (trace_array_get(tr) < 0) {
1533 put_system(dir);
1534 return -ENODEV;
1535 }
1536
1537 ret = tracing_open_generic(inode, filp);
1538 if (ret < 0) {
1539 trace_array_put(tr);
1540 put_system(dir);
1541 }
1542
1543 return ret;
1544}
1545
1546static int system_tr_open(struct inode *inode, struct file *filp)
1547{
1548 struct trace_subsystem_dir *dir;
1549 struct trace_array *tr = inode->i_private;
1550 int ret;
1551
1552 /* Make a temporary dir that has no system but points to tr */
1553 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1554 if (!dir)
1555 return -ENOMEM;
1556
1557 ret = tracing_open_generic_tr(inode, filp);
1558 if (ret < 0) {
1559 kfree(dir);
1560 return ret;
1561 }
1562 dir->tr = tr;
1563 filp->private_data = dir;
1564
1565 return 0;
1566}
1567
1568static int subsystem_release(struct inode *inode, struct file *file)
1569{
1570 struct trace_subsystem_dir *dir = file->private_data;
1571
1572 trace_array_put(dir->tr);
1573
1574 /*
1575 * If dir->subsystem is NULL, then this is a temporary
1576 * descriptor that was made for a trace_array to enable
1577 * all subsystems.
1578 */
1579 if (dir->subsystem)
1580 put_system(dir);
1581 else
1582 kfree(dir);
1583
1584 return 0;
1585}
1586
1587static ssize_t
1588subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1589 loff_t *ppos)
1590{
1591 struct trace_subsystem_dir *dir = filp->private_data;
1592 struct event_subsystem *system = dir->subsystem;
1593 struct trace_seq *s;
1594 int r;
1595
1596 if (*ppos)
1597 return 0;
1598
1599 s = kmalloc(sizeof(*s), GFP_KERNEL);
1600 if (!s)
1601 return -ENOMEM;
1602
1603 trace_seq_init(s);
1604
1605 print_subsystem_event_filter(system, s);
1606 r = simple_read_from_buffer(ubuf, cnt, ppos,
1607 s->buffer, trace_seq_used(s));
1608
1609 kfree(s);
1610
1611 return r;
1612}
1613
1614static ssize_t
1615subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1616 loff_t *ppos)
1617{
1618 struct trace_subsystem_dir *dir = filp->private_data;
1619 char *buf;
1620 int err;
1621
1622 if (cnt >= PAGE_SIZE)
1623 return -EINVAL;
1624
1625 buf = memdup_user_nul(ubuf, cnt);
1626 if (IS_ERR(buf))
1627 return PTR_ERR(buf);
1628
1629 err = apply_subsystem_event_filter(dir, buf);
1630 kfree(buf);
1631 if (err < 0)
1632 return err;
1633
1634 *ppos += cnt;
1635
1636 return cnt;
1637}
1638
1639static ssize_t
1640show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1641{
1642 int (*func)(struct trace_seq *s) = filp->private_data;
1643 struct trace_seq *s;
1644 int r;
1645
1646 if (*ppos)
1647 return 0;
1648
1649 s = kmalloc(sizeof(*s), GFP_KERNEL);
1650 if (!s)
1651 return -ENOMEM;
1652
1653 trace_seq_init(s);
1654
1655 func(s);
1656 r = simple_read_from_buffer(ubuf, cnt, ppos,
1657 s->buffer, trace_seq_used(s));
1658
1659 kfree(s);
1660
1661 return r;
1662}
1663
1664static void ignore_task_cpu(void *data)
1665{
1666 struct trace_array *tr = data;
1667 struct trace_pid_list *pid_list;
1668 struct trace_pid_list *no_pid_list;
1669
1670 /*
1671 * This function is called by on_each_cpu() while the
1672 * event_mutex is held.
1673 */
1674 pid_list = rcu_dereference_protected(tr->filtered_pids,
1675 mutex_is_locked(&event_mutex));
1676 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
1677 mutex_is_locked(&event_mutex));
1678
1679 this_cpu_write(tr->array_buffer.data->ignore_pid,
1680 trace_ignore_this_task(pid_list, no_pid_list, current));
1681}
1682
1683static void register_pid_events(struct trace_array *tr)
1684{
1685 /*
1686 * Register a probe that is called before all other probes
1687 * to set ignore_pid if next or prev do not match.
1688 * Register a probe this is called after all other probes
1689 * to only keep ignore_pid set if next pid matches.
1690 */
1691 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1692 tr, INT_MAX);
1693 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1694 tr, 0);
1695
1696 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1697 tr, INT_MAX);
1698 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1699 tr, 0);
1700
1701 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1702 tr, INT_MAX);
1703 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1704 tr, 0);
1705
1706 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1707 tr, INT_MAX);
1708 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1709 tr, 0);
1710}
1711
1712static ssize_t
1713event_pid_write(struct file *filp, const char __user *ubuf,
1714 size_t cnt, loff_t *ppos, int type)
1715{
1716 struct seq_file *m = filp->private_data;
1717 struct trace_array *tr = m->private;
1718 struct trace_pid_list *filtered_pids = NULL;
1719 struct trace_pid_list *other_pids = NULL;
1720 struct trace_pid_list *pid_list;
1721 struct trace_event_file *file;
1722 ssize_t ret;
1723
1724 if (!cnt)
1725 return 0;
1726
1727 ret = tracing_update_buffers();
1728 if (ret < 0)
1729 return ret;
1730
1731 mutex_lock(&event_mutex);
1732
1733 if (type == TRACE_PIDS) {
1734 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1735 lockdep_is_held(&event_mutex));
1736 other_pids = rcu_dereference_protected(tr->filtered_no_pids,
1737 lockdep_is_held(&event_mutex));
1738 } else {
1739 filtered_pids = rcu_dereference_protected(tr->filtered_no_pids,
1740 lockdep_is_held(&event_mutex));
1741 other_pids = rcu_dereference_protected(tr->filtered_pids,
1742 lockdep_is_held(&event_mutex));
1743 }
1744
1745 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
1746 if (ret < 0)
1747 goto out;
1748
1749 if (type == TRACE_PIDS)
1750 rcu_assign_pointer(tr->filtered_pids, pid_list);
1751 else
1752 rcu_assign_pointer(tr->filtered_no_pids, pid_list);
1753
1754 list_for_each_entry(file, &tr->events, list) {
1755 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1756 }
1757
1758 if (filtered_pids) {
1759 tracepoint_synchronize_unregister();
1760 trace_free_pid_list(filtered_pids);
1761 } else if (pid_list && !other_pids) {
1762 register_pid_events(tr);
1763 }
1764
1765 /*
1766 * Ignoring of pids is done at task switch. But we have to
1767 * check for those tasks that are currently running.
1768 * Always do this in case a pid was appended or removed.
1769 */
1770 on_each_cpu(ignore_task_cpu, tr, 1);
1771
1772 out:
1773 mutex_unlock(&event_mutex);
1774
1775 if (ret > 0)
1776 *ppos += ret;
1777
1778 return ret;
1779}
1780
1781static ssize_t
1782ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1783 size_t cnt, loff_t *ppos)
1784{
1785 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
1786}
1787
1788static ssize_t
1789ftrace_event_npid_write(struct file *filp, const char __user *ubuf,
1790 size_t cnt, loff_t *ppos)
1791{
1792 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
1793}
1794
1795static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1796static int ftrace_event_set_open(struct inode *inode, struct file *file);
1797static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
1798static int ftrace_event_set_npid_open(struct inode *inode, struct file *file);
1799static int ftrace_event_release(struct inode *inode, struct file *file);
1800
1801static const struct seq_operations show_event_seq_ops = {
1802 .start = t_start,
1803 .next = t_next,
1804 .show = t_show,
1805 .stop = t_stop,
1806};
1807
1808static const struct seq_operations show_set_event_seq_ops = {
1809 .start = s_start,
1810 .next = s_next,
1811 .show = t_show,
1812 .stop = t_stop,
1813};
1814
1815static const struct seq_operations show_set_pid_seq_ops = {
1816 .start = p_start,
1817 .next = p_next,
1818 .show = trace_pid_show,
1819 .stop = p_stop,
1820};
1821
1822static const struct seq_operations show_set_no_pid_seq_ops = {
1823 .start = np_start,
1824 .next = np_next,
1825 .show = trace_pid_show,
1826 .stop = p_stop,
1827};
1828
1829static const struct file_operations ftrace_avail_fops = {
1830 .open = ftrace_event_avail_open,
1831 .read = seq_read,
1832 .llseek = seq_lseek,
1833 .release = seq_release,
1834};
1835
1836static const struct file_operations ftrace_set_event_fops = {
1837 .open = ftrace_event_set_open,
1838 .read = seq_read,
1839 .write = ftrace_event_write,
1840 .llseek = seq_lseek,
1841 .release = ftrace_event_release,
1842};
1843
1844static const struct file_operations ftrace_set_event_pid_fops = {
1845 .open = ftrace_event_set_pid_open,
1846 .read = seq_read,
1847 .write = ftrace_event_pid_write,
1848 .llseek = seq_lseek,
1849 .release = ftrace_event_release,
1850};
1851
1852static const struct file_operations ftrace_set_event_notrace_pid_fops = {
1853 .open = ftrace_event_set_npid_open,
1854 .read = seq_read,
1855 .write = ftrace_event_npid_write,
1856 .llseek = seq_lseek,
1857 .release = ftrace_event_release,
1858};
1859
1860static const struct file_operations ftrace_enable_fops = {
1861 .open = tracing_open_generic,
1862 .read = event_enable_read,
1863 .write = event_enable_write,
1864 .llseek = default_llseek,
1865};
1866
1867static const struct file_operations ftrace_event_format_fops = {
1868 .open = trace_format_open,
1869 .read = seq_read,
1870 .llseek = seq_lseek,
1871 .release = seq_release,
1872};
1873
1874static const struct file_operations ftrace_event_id_fops = {
1875 .read = event_id_read,
1876 .llseek = default_llseek,
1877};
1878
1879static const struct file_operations ftrace_event_filter_fops = {
1880 .open = tracing_open_generic,
1881 .read = event_filter_read,
1882 .write = event_filter_write,
1883 .llseek = default_llseek,
1884};
1885
1886static const struct file_operations ftrace_subsystem_filter_fops = {
1887 .open = subsystem_open,
1888 .read = subsystem_filter_read,
1889 .write = subsystem_filter_write,
1890 .llseek = default_llseek,
1891 .release = subsystem_release,
1892};
1893
1894static const struct file_operations ftrace_system_enable_fops = {
1895 .open = subsystem_open,
1896 .read = system_enable_read,
1897 .write = system_enable_write,
1898 .llseek = default_llseek,
1899 .release = subsystem_release,
1900};
1901
1902static const struct file_operations ftrace_tr_enable_fops = {
1903 .open = system_tr_open,
1904 .read = system_enable_read,
1905 .write = system_enable_write,
1906 .llseek = default_llseek,
1907 .release = subsystem_release,
1908};
1909
1910static const struct file_operations ftrace_show_header_fops = {
1911 .open = tracing_open_generic,
1912 .read = show_header,
1913 .llseek = default_llseek,
1914};
1915
1916static int
1917ftrace_event_open(struct inode *inode, struct file *file,
1918 const struct seq_operations *seq_ops)
1919{
1920 struct seq_file *m;
1921 int ret;
1922
1923 ret = security_locked_down(LOCKDOWN_TRACEFS);
1924 if (ret)
1925 return ret;
1926
1927 ret = seq_open(file, seq_ops);
1928 if (ret < 0)
1929 return ret;
1930 m = file->private_data;
1931 /* copy tr over to seq ops */
1932 m->private = inode->i_private;
1933
1934 return ret;
1935}
1936
1937static int ftrace_event_release(struct inode *inode, struct file *file)
1938{
1939 struct trace_array *tr = inode->i_private;
1940
1941 trace_array_put(tr);
1942
1943 return seq_release(inode, file);
1944}
1945
1946static int
1947ftrace_event_avail_open(struct inode *inode, struct file *file)
1948{
1949 const struct seq_operations *seq_ops = &show_event_seq_ops;
1950
1951 /* Checks for tracefs lockdown */
1952 return ftrace_event_open(inode, file, seq_ops);
1953}
1954
1955static int
1956ftrace_event_set_open(struct inode *inode, struct file *file)
1957{
1958 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1959 struct trace_array *tr = inode->i_private;
1960 int ret;
1961
1962 ret = tracing_check_open_get_tr(tr);
1963 if (ret)
1964 return ret;
1965
1966 if ((file->f_mode & FMODE_WRITE) &&
1967 (file->f_flags & O_TRUNC))
1968 ftrace_clear_events(tr);
1969
1970 ret = ftrace_event_open(inode, file, seq_ops);
1971 if (ret < 0)
1972 trace_array_put(tr);
1973 return ret;
1974}
1975
1976static int
1977ftrace_event_set_pid_open(struct inode *inode, struct file *file)
1978{
1979 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
1980 struct trace_array *tr = inode->i_private;
1981 int ret;
1982
1983 ret = tracing_check_open_get_tr(tr);
1984 if (ret)
1985 return ret;
1986
1987 if ((file->f_mode & FMODE_WRITE) &&
1988 (file->f_flags & O_TRUNC))
1989 ftrace_clear_event_pids(tr, TRACE_PIDS);
1990
1991 ret = ftrace_event_open(inode, file, seq_ops);
1992 if (ret < 0)
1993 trace_array_put(tr);
1994 return ret;
1995}
1996
1997static int
1998ftrace_event_set_npid_open(struct inode *inode, struct file *file)
1999{
2000 const struct seq_operations *seq_ops = &show_set_no_pid_seq_ops;
2001 struct trace_array *tr = inode->i_private;
2002 int ret;
2003
2004 ret = tracing_check_open_get_tr(tr);
2005 if (ret)
2006 return ret;
2007
2008 if ((file->f_mode & FMODE_WRITE) &&
2009 (file->f_flags & O_TRUNC))
2010 ftrace_clear_event_pids(tr, TRACE_NO_PIDS);
2011
2012 ret = ftrace_event_open(inode, file, seq_ops);
2013 if (ret < 0)
2014 trace_array_put(tr);
2015 return ret;
2016}
2017
2018static struct event_subsystem *
2019create_new_subsystem(const char *name)
2020{
2021 struct event_subsystem *system;
2022
2023 /* need to create new entry */
2024 system = kmalloc(sizeof(*system), GFP_KERNEL);
2025 if (!system)
2026 return NULL;
2027
2028 system->ref_count = 1;
2029
2030 /* Only allocate if dynamic (kprobes and modules) */
2031 system->name = kstrdup_const(name, GFP_KERNEL);
2032 if (!system->name)
2033 goto out_free;
2034
2035 system->filter = NULL;
2036
2037 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
2038 if (!system->filter)
2039 goto out_free;
2040
2041 list_add(&system->list, &event_subsystems);
2042
2043 return system;
2044
2045 out_free:
2046 kfree_const(system->name);
2047 kfree(system);
2048 return NULL;
2049}
2050
2051static struct dentry *
2052event_subsystem_dir(struct trace_array *tr, const char *name,
2053 struct trace_event_file *file, struct dentry *parent)
2054{
2055 struct trace_subsystem_dir *dir;
2056 struct event_subsystem *system;
2057 struct dentry *entry;
2058
2059 /* First see if we did not already create this dir */
2060 list_for_each_entry(dir, &tr->systems, list) {
2061 system = dir->subsystem;
2062 if (strcmp(system->name, name) == 0) {
2063 dir->nr_events++;
2064 file->system = dir;
2065 return dir->entry;
2066 }
2067 }
2068
2069 /* Now see if the system itself exists. */
2070 list_for_each_entry(system, &event_subsystems, list) {
2071 if (strcmp(system->name, name) == 0)
2072 break;
2073 }
2074 /* Reset system variable when not found */
2075 if (&system->list == &event_subsystems)
2076 system = NULL;
2077
2078 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
2079 if (!dir)
2080 goto out_fail;
2081
2082 if (!system) {
2083 system = create_new_subsystem(name);
2084 if (!system)
2085 goto out_free;
2086 } else
2087 __get_system(system);
2088
2089 dir->entry = tracefs_create_dir(name, parent);
2090 if (!dir->entry) {
2091 pr_warn("Failed to create system directory %s\n", name);
2092 __put_system(system);
2093 goto out_free;
2094 }
2095
2096 dir->tr = tr;
2097 dir->ref_count = 1;
2098 dir->nr_events = 1;
2099 dir->subsystem = system;
2100 file->system = dir;
2101
2102 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
2103 &ftrace_subsystem_filter_fops);
2104 if (!entry) {
2105 kfree(system->filter);
2106 system->filter = NULL;
2107 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
2108 }
2109
2110 trace_create_file("enable", 0644, dir->entry, dir,
2111 &ftrace_system_enable_fops);
2112
2113 list_add(&dir->list, &tr->systems);
2114
2115 return dir->entry;
2116
2117 out_free:
2118 kfree(dir);
2119 out_fail:
2120 /* Only print this message if failed on memory allocation */
2121 if (!dir || !system)
2122 pr_warn("No memory to create event subsystem %s\n", name);
2123 return NULL;
2124}
2125
2126static int
2127event_create_dir(struct dentry *parent, struct trace_event_file *file)
2128{
2129 struct trace_event_call *call = file->event_call;
2130 struct trace_array *tr = file->tr;
2131 struct list_head *head;
2132 struct dentry *d_events;
2133 const char *name;
2134 int ret;
2135
2136 /*
2137 * If the trace point header did not define TRACE_SYSTEM
2138 * then the system would be called "TRACE_SYSTEM".
2139 */
2140 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
2141 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
2142 if (!d_events)
2143 return -ENOMEM;
2144 } else
2145 d_events = parent;
2146
2147 name = trace_event_name(call);
2148 file->dir = tracefs_create_dir(name, d_events);
2149 if (!file->dir) {
2150 pr_warn("Could not create tracefs '%s' directory\n", name);
2151 return -1;
2152 }
2153
2154 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2155 trace_create_file("enable", 0644, file->dir, file,
2156 &ftrace_enable_fops);
2157
2158#ifdef CONFIG_PERF_EVENTS
2159 if (call->event.type && call->class->reg)
2160 trace_create_file("id", 0444, file->dir,
2161 (void *)(long)call->event.type,
2162 &ftrace_event_id_fops);
2163#endif
2164
2165 /*
2166 * Other events may have the same class. Only update
2167 * the fields if they are not already defined.
2168 */
2169 head = trace_get_fields(call);
2170 if (list_empty(head)) {
2171 struct trace_event_fields *field = call->class->fields_array;
2172 unsigned int offset = sizeof(struct trace_entry);
2173
2174 for (; field->type; field++) {
2175 if (field->type == TRACE_FUNCTION_TYPE) {
2176 ret = field->define_fields(call);
2177 break;
2178 }
2179
2180 offset = ALIGN(offset, field->align);
2181 ret = trace_define_field(call, field->type, field->name,
2182 offset, field->size,
2183 field->is_signed, field->filter_type);
2184 if (ret)
2185 break;
2186
2187 offset += field->size;
2188 }
2189 if (ret < 0) {
2190 pr_warn("Could not initialize trace point events/%s\n",
2191 name);
2192 return -1;
2193 }
2194 }
2195
2196 /*
2197 * Only event directories that can be enabled should have
2198 * triggers or filters.
2199 */
2200 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
2201 trace_create_file("filter", 0644, file->dir, file,
2202 &ftrace_event_filter_fops);
2203
2204 trace_create_file("trigger", 0644, file->dir, file,
2205 &event_trigger_fops);
2206 }
2207
2208#ifdef CONFIG_HIST_TRIGGERS
2209 trace_create_file("hist", 0444, file->dir, file,
2210 &event_hist_fops);
2211#endif
2212#ifdef CONFIG_HIST_TRIGGERS_DEBUG
2213 trace_create_file("hist_debug", 0444, file->dir, file,
2214 &event_hist_debug_fops);
2215#endif
2216 trace_create_file("format", 0444, file->dir, call,
2217 &ftrace_event_format_fops);
2218
2219#ifdef CONFIG_TRACE_EVENT_INJECT
2220 if (call->event.type && call->class->reg)
2221 trace_create_file("inject", 0200, file->dir, file,
2222 &event_inject_fops);
2223#endif
2224
2225 return 0;
2226}
2227
2228static void remove_event_from_tracers(struct trace_event_call *call)
2229{
2230 struct trace_event_file *file;
2231 struct trace_array *tr;
2232
2233 do_for_each_event_file_safe(tr, file) {
2234 if (file->event_call != call)
2235 continue;
2236
2237 remove_event_file_dir(file);
2238 /*
2239 * The do_for_each_event_file_safe() is
2240 * a double loop. After finding the call for this
2241 * trace_array, we use break to jump to the next
2242 * trace_array.
2243 */
2244 break;
2245 } while_for_each_event_file();
2246}
2247
2248static void event_remove(struct trace_event_call *call)
2249{
2250 struct trace_array *tr;
2251 struct trace_event_file *file;
2252
2253 do_for_each_event_file(tr, file) {
2254 if (file->event_call != call)
2255 continue;
2256
2257 if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
2258 tr->clear_trace = true;
2259
2260 ftrace_event_enable_disable(file, 0);
2261 /*
2262 * The do_for_each_event_file() is
2263 * a double loop. After finding the call for this
2264 * trace_array, we use break to jump to the next
2265 * trace_array.
2266 */
2267 break;
2268 } while_for_each_event_file();
2269
2270 if (call->event.funcs)
2271 __unregister_trace_event(&call->event);
2272 remove_event_from_tracers(call);
2273 list_del(&call->list);
2274}
2275
2276static int event_init(struct trace_event_call *call)
2277{
2278 int ret = 0;
2279 const char *name;
2280
2281 name = trace_event_name(call);
2282 if (WARN_ON(!name))
2283 return -EINVAL;
2284
2285 if (call->class->raw_init) {
2286 ret = call->class->raw_init(call);
2287 if (ret < 0 && ret != -ENOSYS)
2288 pr_warn("Could not initialize trace events/%s\n", name);
2289 }
2290
2291 return ret;
2292}
2293
2294static int
2295__register_event(struct trace_event_call *call, struct module *mod)
2296{
2297 int ret;
2298
2299 ret = event_init(call);
2300 if (ret < 0)
2301 return ret;
2302
2303 list_add(&call->list, &ftrace_events);
2304 call->mod = mod;
2305
2306 return 0;
2307}
2308
2309static char *eval_replace(char *ptr, struct trace_eval_map *map, int len)
2310{
2311 int rlen;
2312 int elen;
2313
2314 /* Find the length of the eval value as a string */
2315 elen = snprintf(ptr, 0, "%ld", map->eval_value);
2316 /* Make sure there's enough room to replace the string with the value */
2317 if (len < elen)
2318 return NULL;
2319
2320 snprintf(ptr, elen + 1, "%ld", map->eval_value);
2321
2322 /* Get the rest of the string of ptr */
2323 rlen = strlen(ptr + len);
2324 memmove(ptr + elen, ptr + len, rlen);
2325 /* Make sure we end the new string */
2326 ptr[elen + rlen] = 0;
2327
2328 return ptr + elen;
2329}
2330
2331static void update_event_printk(struct trace_event_call *call,
2332 struct trace_eval_map *map)
2333{
2334 char *ptr;
2335 int quote = 0;
2336 int len = strlen(map->eval_string);
2337
2338 for (ptr = call->print_fmt; *ptr; ptr++) {
2339 if (*ptr == '\\') {
2340 ptr++;
2341 /* paranoid */
2342 if (!*ptr)
2343 break;
2344 continue;
2345 }
2346 if (*ptr == '"') {
2347 quote ^= 1;
2348 continue;
2349 }
2350 if (quote)
2351 continue;
2352 if (isdigit(*ptr)) {
2353 /* skip numbers */
2354 do {
2355 ptr++;
2356 /* Check for alpha chars like ULL */
2357 } while (isalnum(*ptr));
2358 if (!*ptr)
2359 break;
2360 /*
2361 * A number must have some kind of delimiter after
2362 * it, and we can ignore that too.
2363 */
2364 continue;
2365 }
2366 if (isalpha(*ptr) || *ptr == '_') {
2367 if (strncmp(map->eval_string, ptr, len) == 0 &&
2368 !isalnum(ptr[len]) && ptr[len] != '_') {
2369 ptr = eval_replace(ptr, map, len);
2370 /* enum/sizeof string smaller than value */
2371 if (WARN_ON_ONCE(!ptr))
2372 return;
2373 /*
2374 * No need to decrement here, as eval_replace()
2375 * returns the pointer to the character passed
2376 * the eval, and two evals can not be placed
2377 * back to back without something in between.
2378 * We can skip that something in between.
2379 */
2380 continue;
2381 }
2382 skip_more:
2383 do {
2384 ptr++;
2385 } while (isalnum(*ptr) || *ptr == '_');
2386 if (!*ptr)
2387 break;
2388 /*
2389 * If what comes after this variable is a '.' or
2390 * '->' then we can continue to ignore that string.
2391 */
2392 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2393 ptr += *ptr == '.' ? 1 : 2;
2394 if (!*ptr)
2395 break;
2396 goto skip_more;
2397 }
2398 /*
2399 * Once again, we can skip the delimiter that came
2400 * after the string.
2401 */
2402 continue;
2403 }
2404 }
2405}
2406
2407void trace_event_eval_update(struct trace_eval_map **map, int len)
2408{
2409 struct trace_event_call *call, *p;
2410 const char *last_system = NULL;
2411 bool first = false;
2412 int last_i;
2413 int i;
2414
2415 down_write(&trace_event_sem);
2416 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2417 /* events are usually grouped together with systems */
2418 if (!last_system || call->class->system != last_system) {
2419 first = true;
2420 last_i = 0;
2421 last_system = call->class->system;
2422 }
2423
2424 /*
2425 * Since calls are grouped by systems, the likelyhood that the
2426 * next call in the iteration belongs to the same system as the
2427 * previous call is high. As an optimization, we skip seaching
2428 * for a map[] that matches the call's system if the last call
2429 * was from the same system. That's what last_i is for. If the
2430 * call has the same system as the previous call, then last_i
2431 * will be the index of the first map[] that has a matching
2432 * system.
2433 */
2434 for (i = last_i; i < len; i++) {
2435 if (call->class->system == map[i]->system) {
2436 /* Save the first system if need be */
2437 if (first) {
2438 last_i = i;
2439 first = false;
2440 }
2441 update_event_printk(call, map[i]);
2442 }
2443 }
2444 }
2445 up_write(&trace_event_sem);
2446}
2447
2448static struct trace_event_file *
2449trace_create_new_event(struct trace_event_call *call,
2450 struct trace_array *tr)
2451{
2452 struct trace_event_file *file;
2453
2454 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2455 if (!file)
2456 return NULL;
2457
2458 file->event_call = call;
2459 file->tr = tr;
2460 atomic_set(&file->sm_ref, 0);
2461 atomic_set(&file->tm_ref, 0);
2462 INIT_LIST_HEAD(&file->triggers);
2463 list_add(&file->list, &tr->events);
2464
2465 return file;
2466}
2467
2468/* Add an event to a trace directory */
2469static int
2470__trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2471{
2472 struct trace_event_file *file;
2473
2474 file = trace_create_new_event(call, tr);
2475 if (!file)
2476 return -ENOMEM;
2477
2478 return event_create_dir(tr->event_dir, file);
2479}
2480
2481/*
2482 * Just create a decriptor for early init. A descriptor is required
2483 * for enabling events at boot. We want to enable events before
2484 * the filesystem is initialized.
2485 */
2486static __init int
2487__trace_early_add_new_event(struct trace_event_call *call,
2488 struct trace_array *tr)
2489{
2490 struct trace_event_file *file;
2491
2492 file = trace_create_new_event(call, tr);
2493 if (!file)
2494 return -ENOMEM;
2495
2496 return 0;
2497}
2498
2499struct ftrace_module_file_ops;
2500static void __add_event_to_tracers(struct trace_event_call *call);
2501
2502/* Add an additional event_call dynamically */
2503int trace_add_event_call(struct trace_event_call *call)
2504{
2505 int ret;
2506 lockdep_assert_held(&event_mutex);
2507
2508 mutex_lock(&trace_types_lock);
2509
2510 ret = __register_event(call, NULL);
2511 if (ret >= 0)
2512 __add_event_to_tracers(call);
2513
2514 mutex_unlock(&trace_types_lock);
2515 return ret;
2516}
2517
2518/*
2519 * Must be called under locking of trace_types_lock, event_mutex and
2520 * trace_event_sem.
2521 */
2522static void __trace_remove_event_call(struct trace_event_call *call)
2523{
2524 event_remove(call);
2525 trace_destroy_fields(call);
2526 free_event_filter(call->filter);
2527 call->filter = NULL;
2528}
2529
2530static int probe_remove_event_call(struct trace_event_call *call)
2531{
2532 struct trace_array *tr;
2533 struct trace_event_file *file;
2534
2535#ifdef CONFIG_PERF_EVENTS
2536 if (call->perf_refcount)
2537 return -EBUSY;
2538#endif
2539 do_for_each_event_file(tr, file) {
2540 if (file->event_call != call)
2541 continue;
2542 /*
2543 * We can't rely on ftrace_event_enable_disable(enable => 0)
2544 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2545 * TRACE_REG_UNREGISTER.
2546 */
2547 if (file->flags & EVENT_FILE_FL_ENABLED)
2548 return -EBUSY;
2549 /*
2550 * The do_for_each_event_file_safe() is
2551 * a double loop. After finding the call for this
2552 * trace_array, we use break to jump to the next
2553 * trace_array.
2554 */
2555 break;
2556 } while_for_each_event_file();
2557
2558 __trace_remove_event_call(call);
2559
2560 return 0;
2561}
2562
2563/* Remove an event_call */
2564int trace_remove_event_call(struct trace_event_call *call)
2565{
2566 int ret;
2567
2568 lockdep_assert_held(&event_mutex);
2569
2570 mutex_lock(&trace_types_lock);
2571 down_write(&trace_event_sem);
2572 ret = probe_remove_event_call(call);
2573 up_write(&trace_event_sem);
2574 mutex_unlock(&trace_types_lock);
2575
2576 return ret;
2577}
2578
2579#define for_each_event(event, start, end) \
2580 for (event = start; \
2581 (unsigned long)event < (unsigned long)end; \
2582 event++)
2583
2584#ifdef CONFIG_MODULES
2585
2586static void trace_module_add_events(struct module *mod)
2587{
2588 struct trace_event_call **call, **start, **end;
2589
2590 if (!mod->num_trace_events)
2591 return;
2592
2593 /* Don't add infrastructure for mods without tracepoints */
2594 if (trace_module_has_bad_taint(mod)) {
2595 pr_err("%s: module has bad taint, not creating trace events\n",
2596 mod->name);
2597 return;
2598 }
2599
2600 start = mod->trace_events;
2601 end = mod->trace_events + mod->num_trace_events;
2602
2603 for_each_event(call, start, end) {
2604 __register_event(*call, mod);
2605 __add_event_to_tracers(*call);
2606 }
2607}
2608
2609static void trace_module_remove_events(struct module *mod)
2610{
2611 struct trace_event_call *call, *p;
2612
2613 down_write(&trace_event_sem);
2614 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2615 if (call->mod == mod)
2616 __trace_remove_event_call(call);
2617 }
2618 up_write(&trace_event_sem);
2619
2620 /*
2621 * It is safest to reset the ring buffer if the module being unloaded
2622 * registered any events that were used. The only worry is if
2623 * a new module gets loaded, and takes on the same id as the events
2624 * of this module. When printing out the buffer, traced events left
2625 * over from this module may be passed to the new module events and
2626 * unexpected results may occur.
2627 */
2628 tracing_reset_all_online_cpus();
2629}
2630
2631static int trace_module_notify(struct notifier_block *self,
2632 unsigned long val, void *data)
2633{
2634 struct module *mod = data;
2635
2636 mutex_lock(&event_mutex);
2637 mutex_lock(&trace_types_lock);
2638 switch (val) {
2639 case MODULE_STATE_COMING:
2640 trace_module_add_events(mod);
2641 break;
2642 case MODULE_STATE_GOING:
2643 trace_module_remove_events(mod);
2644 break;
2645 }
2646 mutex_unlock(&trace_types_lock);
2647 mutex_unlock(&event_mutex);
2648
2649 return 0;
2650}
2651
2652static struct notifier_block trace_module_nb = {
2653 .notifier_call = trace_module_notify,
2654 .priority = 1, /* higher than trace.c module notify */
2655};
2656#endif /* CONFIG_MODULES */
2657
2658/* Create a new event directory structure for a trace directory. */
2659static void
2660__trace_add_event_dirs(struct trace_array *tr)
2661{
2662 struct trace_event_call *call;
2663 int ret;
2664
2665 list_for_each_entry(call, &ftrace_events, list) {
2666 ret = __trace_add_new_event(call, tr);
2667 if (ret < 0)
2668 pr_warn("Could not create directory for event %s\n",
2669 trace_event_name(call));
2670 }
2671}
2672
2673/* Returns any file that matches the system and event */
2674struct trace_event_file *
2675__find_event_file(struct trace_array *tr, const char *system, const char *event)
2676{
2677 struct trace_event_file *file;
2678 struct trace_event_call *call;
2679 const char *name;
2680
2681 list_for_each_entry(file, &tr->events, list) {
2682
2683 call = file->event_call;
2684 name = trace_event_name(call);
2685
2686 if (!name || !call->class)
2687 continue;
2688
2689 if (strcmp(event, name) == 0 &&
2690 strcmp(system, call->class->system) == 0)
2691 return file;
2692 }
2693 return NULL;
2694}
2695
2696/* Returns valid trace event files that match system and event */
2697struct trace_event_file *
2698find_event_file(struct trace_array *tr, const char *system, const char *event)
2699{
2700 struct trace_event_file *file;
2701
2702 file = __find_event_file(tr, system, event);
2703 if (!file || !file->event_call->class->reg ||
2704 file->event_call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2705 return NULL;
2706
2707 return file;
2708}
2709
2710/**
2711 * trace_get_event_file - Find and return a trace event file
2712 * @instance: The name of the trace instance containing the event
2713 * @system: The name of the system containing the event
2714 * @event: The name of the event
2715 *
2716 * Return a trace event file given the trace instance name, trace
2717 * system, and trace event name. If the instance name is NULL, it
2718 * refers to the top-level trace array.
2719 *
2720 * This function will look it up and return it if found, after calling
2721 * trace_array_get() to prevent the instance from going away, and
2722 * increment the event's module refcount to prevent it from being
2723 * removed.
2724 *
2725 * To release the file, call trace_put_event_file(), which will call
2726 * trace_array_put() and decrement the event's module refcount.
2727 *
2728 * Return: The trace event on success, ERR_PTR otherwise.
2729 */
2730struct trace_event_file *trace_get_event_file(const char *instance,
2731 const char *system,
2732 const char *event)
2733{
2734 struct trace_array *tr = top_trace_array();
2735 struct trace_event_file *file = NULL;
2736 int ret = -EINVAL;
2737
2738 if (instance) {
2739 tr = trace_array_find_get(instance);
2740 if (!tr)
2741 return ERR_PTR(-ENOENT);
2742 } else {
2743 ret = trace_array_get(tr);
2744 if (ret)
2745 return ERR_PTR(ret);
2746 }
2747
2748 mutex_lock(&event_mutex);
2749
2750 file = find_event_file(tr, system, event);
2751 if (!file) {
2752 trace_array_put(tr);
2753 ret = -EINVAL;
2754 goto out;
2755 }
2756
2757 /* Don't let event modules unload while in use */
2758 ret = try_module_get(file->event_call->mod);
2759 if (!ret) {
2760 trace_array_put(tr);
2761 ret = -EBUSY;
2762 goto out;
2763 }
2764
2765 ret = 0;
2766 out:
2767 mutex_unlock(&event_mutex);
2768
2769 if (ret)
2770 file = ERR_PTR(ret);
2771
2772 return file;
2773}
2774EXPORT_SYMBOL_GPL(trace_get_event_file);
2775
2776/**
2777 * trace_put_event_file - Release a file from trace_get_event_file()
2778 * @file: The trace event file
2779 *
2780 * If a file was retrieved using trace_get_event_file(), this should
2781 * be called when it's no longer needed. It will cancel the previous
2782 * trace_array_get() called by that function, and decrement the
2783 * event's module refcount.
2784 */
2785void trace_put_event_file(struct trace_event_file *file)
2786{
2787 mutex_lock(&event_mutex);
2788 module_put(file->event_call->mod);
2789 mutex_unlock(&event_mutex);
2790
2791 trace_array_put(file->tr);
2792}
2793EXPORT_SYMBOL_GPL(trace_put_event_file);
2794
2795#ifdef CONFIG_DYNAMIC_FTRACE
2796
2797/* Avoid typos */
2798#define ENABLE_EVENT_STR "enable_event"
2799#define DISABLE_EVENT_STR "disable_event"
2800
2801struct event_probe_data {
2802 struct trace_event_file *file;
2803 unsigned long count;
2804 int ref;
2805 bool enable;
2806};
2807
2808static void update_event_probe(struct event_probe_data *data)
2809{
2810 if (data->enable)
2811 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2812 else
2813 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2814}
2815
2816static void
2817event_enable_probe(unsigned long ip, unsigned long parent_ip,
2818 struct trace_array *tr, struct ftrace_probe_ops *ops,
2819 void *data)
2820{
2821 struct ftrace_func_mapper *mapper = data;
2822 struct event_probe_data *edata;
2823 void **pdata;
2824
2825 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2826 if (!pdata || !*pdata)
2827 return;
2828
2829 edata = *pdata;
2830 update_event_probe(edata);
2831}
2832
2833static void
2834event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
2835 struct trace_array *tr, struct ftrace_probe_ops *ops,
2836 void *data)
2837{
2838 struct ftrace_func_mapper *mapper = data;
2839 struct event_probe_data *edata;
2840 void **pdata;
2841
2842 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2843 if (!pdata || !*pdata)
2844 return;
2845
2846 edata = *pdata;
2847
2848 if (!edata->count)
2849 return;
2850
2851 /* Skip if the event is in a state we want to switch to */
2852 if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
2853 return;
2854
2855 if (edata->count != -1)
2856 (edata->count)--;
2857
2858 update_event_probe(edata);
2859}
2860
2861static int
2862event_enable_print(struct seq_file *m, unsigned long ip,
2863 struct ftrace_probe_ops *ops, void *data)
2864{
2865 struct ftrace_func_mapper *mapper = data;
2866 struct event_probe_data *edata;
2867 void **pdata;
2868
2869 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2870
2871 if (WARN_ON_ONCE(!pdata || !*pdata))
2872 return 0;
2873
2874 edata = *pdata;
2875
2876 seq_printf(m, "%ps:", (void *)ip);
2877
2878 seq_printf(m, "%s:%s:%s",
2879 edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2880 edata->file->event_call->class->system,
2881 trace_event_name(edata->file->event_call));
2882
2883 if (edata->count == -1)
2884 seq_puts(m, ":unlimited\n");
2885 else
2886 seq_printf(m, ":count=%ld\n", edata->count);
2887
2888 return 0;
2889}
2890
2891static int
2892event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
2893 unsigned long ip, void *init_data, void **data)
2894{
2895 struct ftrace_func_mapper *mapper = *data;
2896 struct event_probe_data *edata = init_data;
2897 int ret;
2898
2899 if (!mapper) {
2900 mapper = allocate_ftrace_func_mapper();
2901 if (!mapper)
2902 return -ENODEV;
2903 *data = mapper;
2904 }
2905
2906 ret = ftrace_func_mapper_add_ip(mapper, ip, edata);
2907 if (ret < 0)
2908 return ret;
2909
2910 edata->ref++;
2911
2912 return 0;
2913}
2914
2915static int free_probe_data(void *data)
2916{
2917 struct event_probe_data *edata = data;
2918
2919 edata->ref--;
2920 if (!edata->ref) {
2921 /* Remove the SOFT_MODE flag */
2922 __ftrace_event_enable_disable(edata->file, 0, 1);
2923 module_put(edata->file->event_call->mod);
2924 kfree(edata);
2925 }
2926 return 0;
2927}
2928
2929static void
2930event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
2931 unsigned long ip, void *data)
2932{
2933 struct ftrace_func_mapper *mapper = data;
2934 struct event_probe_data *edata;
2935
2936 if (!ip) {
2937 if (!mapper)
2938 return;
2939 free_ftrace_func_mapper(mapper, free_probe_data);
2940 return;
2941 }
2942
2943 edata = ftrace_func_mapper_remove_ip(mapper, ip);
2944
2945 if (WARN_ON_ONCE(!edata))
2946 return;
2947
2948 if (WARN_ON_ONCE(edata->ref <= 0))
2949 return;
2950
2951 free_probe_data(edata);
2952}
2953
2954static struct ftrace_probe_ops event_enable_probe_ops = {
2955 .func = event_enable_probe,
2956 .print = event_enable_print,
2957 .init = event_enable_init,
2958 .free = event_enable_free,
2959};
2960
2961static struct ftrace_probe_ops event_enable_count_probe_ops = {
2962 .func = event_enable_count_probe,
2963 .print = event_enable_print,
2964 .init = event_enable_init,
2965 .free = event_enable_free,
2966};
2967
2968static struct ftrace_probe_ops event_disable_probe_ops = {
2969 .func = event_enable_probe,
2970 .print = event_enable_print,
2971 .init = event_enable_init,
2972 .free = event_enable_free,
2973};
2974
2975static struct ftrace_probe_ops event_disable_count_probe_ops = {
2976 .func = event_enable_count_probe,
2977 .print = event_enable_print,
2978 .init = event_enable_init,
2979 .free = event_enable_free,
2980};
2981
2982static int
2983event_enable_func(struct trace_array *tr, struct ftrace_hash *hash,
2984 char *glob, char *cmd, char *param, int enabled)
2985{
2986 struct trace_event_file *file;
2987 struct ftrace_probe_ops *ops;
2988 struct event_probe_data *data;
2989 const char *system;
2990 const char *event;
2991 char *number;
2992 bool enable;
2993 int ret;
2994
2995 if (!tr)
2996 return -ENODEV;
2997
2998 /* hash funcs only work with set_ftrace_filter */
2999 if (!enabled || !param)
3000 return -EINVAL;
3001
3002 system = strsep(¶m, ":");
3003 if (!param)
3004 return -EINVAL;
3005
3006 event = strsep(¶m, ":");
3007
3008 mutex_lock(&event_mutex);
3009
3010 ret = -EINVAL;
3011 file = find_event_file(tr, system, event);
3012 if (!file)
3013 goto out;
3014
3015 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
3016
3017 if (enable)
3018 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
3019 else
3020 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
3021
3022 if (glob[0] == '!') {
3023 ret = unregister_ftrace_function_probe_func(glob+1, tr, ops);
3024 goto out;
3025 }
3026
3027 ret = -ENOMEM;
3028
3029 data = kzalloc(sizeof(*data), GFP_KERNEL);
3030 if (!data)
3031 goto out;
3032
3033 data->enable = enable;
3034 data->count = -1;
3035 data->file = file;
3036
3037 if (!param)
3038 goto out_reg;
3039
3040 number = strsep(¶m, ":");
3041
3042 ret = -EINVAL;
3043 if (!strlen(number))
3044 goto out_free;
3045
3046 /*
3047 * We use the callback data field (which is a pointer)
3048 * as our counter.
3049 */
3050 ret = kstrtoul(number, 0, &data->count);
3051 if (ret)
3052 goto out_free;
3053
3054 out_reg:
3055 /* Don't let event modules unload while probe registered */
3056 ret = try_module_get(file->event_call->mod);
3057 if (!ret) {
3058 ret = -EBUSY;
3059 goto out_free;
3060 }
3061
3062 ret = __ftrace_event_enable_disable(file, 1, 1);
3063 if (ret < 0)
3064 goto out_put;
3065
3066 ret = register_ftrace_function_probe(glob, tr, ops, data);
3067 /*
3068 * The above returns on success the # of functions enabled,
3069 * but if it didn't find any functions it returns zero.
3070 * Consider no functions a failure too.
3071 */
3072 if (!ret) {
3073 ret = -ENOENT;
3074 goto out_disable;
3075 } else if (ret < 0)
3076 goto out_disable;
3077 /* Just return zero, not the number of enabled functions */
3078 ret = 0;
3079 out:
3080 mutex_unlock(&event_mutex);
3081 return ret;
3082
3083 out_disable:
3084 __ftrace_event_enable_disable(file, 0, 1);
3085 out_put:
3086 module_put(file->event_call->mod);
3087 out_free:
3088 kfree(data);
3089 goto out;
3090}
3091
3092static struct ftrace_func_command event_enable_cmd = {
3093 .name = ENABLE_EVENT_STR,
3094 .func = event_enable_func,
3095};
3096
3097static struct ftrace_func_command event_disable_cmd = {
3098 .name = DISABLE_EVENT_STR,
3099 .func = event_enable_func,
3100};
3101
3102static __init int register_event_cmds(void)
3103{
3104 int ret;
3105
3106 ret = register_ftrace_command(&event_enable_cmd);
3107 if (WARN_ON(ret < 0))
3108 return ret;
3109 ret = register_ftrace_command(&event_disable_cmd);
3110 if (WARN_ON(ret < 0))
3111 unregister_ftrace_command(&event_enable_cmd);
3112 return ret;
3113}
3114#else
3115static inline int register_event_cmds(void) { return 0; }
3116#endif /* CONFIG_DYNAMIC_FTRACE */
3117
3118/*
3119 * The top level array has already had its trace_event_file
3120 * descriptors created in order to allow for early events to
3121 * be recorded. This function is called after the tracefs has been
3122 * initialized, and we now have to create the files associated
3123 * to the events.
3124 */
3125static __init void
3126__trace_early_add_event_dirs(struct trace_array *tr)
3127{
3128 struct trace_event_file *file;
3129 int ret;
3130
3131
3132 list_for_each_entry(file, &tr->events, list) {
3133 ret = event_create_dir(tr->event_dir, file);
3134 if (ret < 0)
3135 pr_warn("Could not create directory for event %s\n",
3136 trace_event_name(file->event_call));
3137 }
3138}
3139
3140/*
3141 * For early boot up, the top trace array requires to have
3142 * a list of events that can be enabled. This must be done before
3143 * the filesystem is set up in order to allow events to be traced
3144 * early.
3145 */
3146static __init void
3147__trace_early_add_events(struct trace_array *tr)
3148{
3149 struct trace_event_call *call;
3150 int ret;
3151
3152 list_for_each_entry(call, &ftrace_events, list) {
3153 /* Early boot up should not have any modules loaded */
3154 if (WARN_ON_ONCE(call->mod))
3155 continue;
3156
3157 ret = __trace_early_add_new_event(call, tr);
3158 if (ret < 0)
3159 pr_warn("Could not create early event %s\n",
3160 trace_event_name(call));
3161 }
3162}
3163
3164/* Remove the event directory structure for a trace directory. */
3165static void
3166__trace_remove_event_dirs(struct trace_array *tr)
3167{
3168 struct trace_event_file *file, *next;
3169
3170 list_for_each_entry_safe(file, next, &tr->events, list)
3171 remove_event_file_dir(file);
3172}
3173
3174static void __add_event_to_tracers(struct trace_event_call *call)
3175{
3176 struct trace_array *tr;
3177
3178 list_for_each_entry(tr, &ftrace_trace_arrays, list)
3179 __trace_add_new_event(call, tr);
3180}
3181
3182extern struct trace_event_call *__start_ftrace_events[];
3183extern struct trace_event_call *__stop_ftrace_events[];
3184
3185static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
3186
3187static __init int setup_trace_event(char *str)
3188{
3189 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
3190 ring_buffer_expanded = true;
3191 tracing_selftest_disabled = true;
3192
3193 return 1;
3194}
3195__setup("trace_event=", setup_trace_event);
3196
3197/* Expects to have event_mutex held when called */
3198static int
3199create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
3200{
3201 struct dentry *d_events;
3202 struct dentry *entry;
3203
3204 entry = tracefs_create_file("set_event", 0644, parent,
3205 tr, &ftrace_set_event_fops);
3206 if (!entry) {
3207 pr_warn("Could not create tracefs 'set_event' entry\n");
3208 return -ENOMEM;
3209 }
3210
3211 d_events = tracefs_create_dir("events", parent);
3212 if (!d_events) {
3213 pr_warn("Could not create tracefs 'events' directory\n");
3214 return -ENOMEM;
3215 }
3216
3217 entry = trace_create_file("enable", 0644, d_events,
3218 tr, &ftrace_tr_enable_fops);
3219 if (!entry) {
3220 pr_warn("Could not create tracefs 'enable' entry\n");
3221 return -ENOMEM;
3222 }
3223
3224 /* There are not as crucial, just warn if they are not created */
3225
3226 entry = tracefs_create_file("set_event_pid", 0644, parent,
3227 tr, &ftrace_set_event_pid_fops);
3228 if (!entry)
3229 pr_warn("Could not create tracefs 'set_event_pid' entry\n");
3230
3231 entry = tracefs_create_file("set_event_notrace_pid", 0644, parent,
3232 tr, &ftrace_set_event_notrace_pid_fops);
3233 if (!entry)
3234 pr_warn("Could not create tracefs 'set_event_notrace_pid' entry\n");
3235
3236 /* ring buffer internal formats */
3237 entry = trace_create_file("header_page", 0444, d_events,
3238 ring_buffer_print_page_header,
3239 &ftrace_show_header_fops);
3240 if (!entry)
3241 pr_warn("Could not create tracefs 'header_page' entry\n");
3242
3243 entry = trace_create_file("header_event", 0444, d_events,
3244 ring_buffer_print_entry_header,
3245 &ftrace_show_header_fops);
3246 if (!entry)
3247 pr_warn("Could not create tracefs 'header_event' entry\n");
3248
3249 tr->event_dir = d_events;
3250
3251 return 0;
3252}
3253
3254/**
3255 * event_trace_add_tracer - add a instance of a trace_array to events
3256 * @parent: The parent dentry to place the files/directories for events in
3257 * @tr: The trace array associated with these events
3258 *
3259 * When a new instance is created, it needs to set up its events
3260 * directory, as well as other files associated with events. It also
3261 * creates the event hierachry in the @parent/events directory.
3262 *
3263 * Returns 0 on success.
3264 *
3265 * Must be called with event_mutex held.
3266 */
3267int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
3268{
3269 int ret;
3270
3271 lockdep_assert_held(&event_mutex);
3272
3273 ret = create_event_toplevel_files(parent, tr);
3274 if (ret)
3275 goto out;
3276
3277 down_write(&trace_event_sem);
3278 __trace_add_event_dirs(tr);
3279 up_write(&trace_event_sem);
3280
3281 out:
3282 return ret;
3283}
3284
3285/*
3286 * The top trace array already had its file descriptors created.
3287 * Now the files themselves need to be created.
3288 */
3289static __init int
3290early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
3291{
3292 int ret;
3293
3294 mutex_lock(&event_mutex);
3295
3296 ret = create_event_toplevel_files(parent, tr);
3297 if (ret)
3298 goto out_unlock;
3299
3300 down_write(&trace_event_sem);
3301 __trace_early_add_event_dirs(tr);
3302 up_write(&trace_event_sem);
3303
3304 out_unlock:
3305 mutex_unlock(&event_mutex);
3306
3307 return ret;
3308}
3309
3310/* Must be called with event_mutex held */
3311int event_trace_del_tracer(struct trace_array *tr)
3312{
3313 lockdep_assert_held(&event_mutex);
3314
3315 /* Disable any event triggers and associated soft-disabled events */
3316 clear_event_triggers(tr);
3317
3318 /* Clear the pid list */
3319 __ftrace_clear_event_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
3320
3321 /* Disable any running events */
3322 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3323
3324 /* Make sure no more events are being executed */
3325 tracepoint_synchronize_unregister();
3326
3327 down_write(&trace_event_sem);
3328 __trace_remove_event_dirs(tr);
3329 tracefs_remove(tr->event_dir);
3330 up_write(&trace_event_sem);
3331
3332 tr->event_dir = NULL;
3333
3334 return 0;
3335}
3336
3337static __init int event_trace_memsetup(void)
3338{
3339 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3340 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3341 return 0;
3342}
3343
3344static __init void
3345early_enable_events(struct trace_array *tr, bool disable_first)
3346{
3347 char *buf = bootup_event_buf;
3348 char *token;
3349 int ret;
3350
3351 while (true) {
3352 token = strsep(&buf, ",");
3353
3354 if (!token)
3355 break;
3356
3357 if (*token) {
3358 /* Restarting syscalls requires that we stop them first */
3359 if (disable_first)
3360 ftrace_set_clr_event(tr, token, 0);
3361
3362 ret = ftrace_set_clr_event(tr, token, 1);
3363 if (ret)
3364 pr_warn("Failed to enable trace event: %s\n", token);
3365 }
3366
3367 /* Put back the comma to allow this to be called again */
3368 if (buf)
3369 *(buf - 1) = ',';
3370 }
3371}
3372
3373static __init int event_trace_enable(void)
3374{
3375 struct trace_array *tr = top_trace_array();
3376 struct trace_event_call **iter, *call;
3377 int ret;
3378
3379 if (!tr)
3380 return -ENODEV;
3381
3382 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3383
3384 call = *iter;
3385 ret = event_init(call);
3386 if (!ret)
3387 list_add(&call->list, &ftrace_events);
3388 }
3389
3390 /*
3391 * We need the top trace array to have a working set of trace
3392 * points at early init, before the debug files and directories
3393 * are created. Create the file entries now, and attach them
3394 * to the actual file dentries later.
3395 */
3396 __trace_early_add_events(tr);
3397
3398 early_enable_events(tr, false);
3399
3400 trace_printk_start_comm();
3401
3402 register_event_cmds();
3403
3404 register_trigger_cmds();
3405
3406 return 0;
3407}
3408
3409/*
3410 * event_trace_enable() is called from trace_event_init() first to
3411 * initialize events and perhaps start any events that are on the
3412 * command line. Unfortunately, there are some events that will not
3413 * start this early, like the system call tracepoints that need
3414 * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
3415 * is called before pid 1 starts, and this flag is never set, making
3416 * the syscall tracepoint never get reached, but the event is enabled
3417 * regardless (and not doing anything).
3418 */
3419static __init int event_trace_enable_again(void)
3420{
3421 struct trace_array *tr;
3422
3423 tr = top_trace_array();
3424 if (!tr)
3425 return -ENODEV;
3426
3427 early_enable_events(tr, true);
3428
3429 return 0;
3430}
3431
3432early_initcall(event_trace_enable_again);
3433
3434__init int event_trace_init(void)
3435{
3436 struct trace_array *tr;
3437 struct dentry *d_tracer;
3438 struct dentry *entry;
3439 int ret;
3440
3441 tr = top_trace_array();
3442 if (!tr)
3443 return -ENODEV;
3444
3445 d_tracer = tracing_init_dentry();
3446 if (IS_ERR(d_tracer))
3447 return 0;
3448
3449 entry = tracefs_create_file("available_events", 0444, d_tracer,
3450 tr, &ftrace_avail_fops);
3451 if (!entry)
3452 pr_warn("Could not create tracefs 'available_events' entry\n");
3453
3454 if (trace_define_generic_fields())
3455 pr_warn("tracing: Failed to allocated generic fields");
3456
3457 if (trace_define_common_fields())
3458 pr_warn("tracing: Failed to allocate common fields");
3459
3460 ret = early_event_add_tracer(d_tracer, tr);
3461 if (ret)
3462 return ret;
3463
3464#ifdef CONFIG_MODULES
3465 ret = register_module_notifier(&trace_module_nb);
3466 if (ret)
3467 pr_warn("Failed to register trace events module notifier\n");
3468#endif
3469 return 0;
3470}
3471
3472void __init trace_event_init(void)
3473{
3474 event_trace_memsetup();
3475 init_ftrace_syscalls();
3476 event_trace_enable();
3477}
3478
3479#ifdef CONFIG_EVENT_TRACE_STARTUP_TEST
3480
3481static DEFINE_SPINLOCK(test_spinlock);
3482static DEFINE_SPINLOCK(test_spinlock_irq);
3483static DEFINE_MUTEX(test_mutex);
3484
3485static __init void test_work(struct work_struct *dummy)
3486{
3487 spin_lock(&test_spinlock);
3488 spin_lock_irq(&test_spinlock_irq);
3489 udelay(1);
3490 spin_unlock_irq(&test_spinlock_irq);
3491 spin_unlock(&test_spinlock);
3492
3493 mutex_lock(&test_mutex);
3494 msleep(1);
3495 mutex_unlock(&test_mutex);
3496}
3497
3498static __init int event_test_thread(void *unused)
3499{
3500 void *test_malloc;
3501
3502 test_malloc = kmalloc(1234, GFP_KERNEL);
3503 if (!test_malloc)
3504 pr_info("failed to kmalloc\n");
3505
3506 schedule_on_each_cpu(test_work);
3507
3508 kfree(test_malloc);
3509
3510 set_current_state(TASK_INTERRUPTIBLE);
3511 while (!kthread_should_stop()) {
3512 schedule();
3513 set_current_state(TASK_INTERRUPTIBLE);
3514 }
3515 __set_current_state(TASK_RUNNING);
3516
3517 return 0;
3518}
3519
3520/*
3521 * Do various things that may trigger events.
3522 */
3523static __init void event_test_stuff(void)
3524{
3525 struct task_struct *test_thread;
3526
3527 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3528 msleep(1);
3529 kthread_stop(test_thread);
3530}
3531
3532/*
3533 * For every trace event defined, we will test each trace point separately,
3534 * and then by groups, and finally all trace points.
3535 */
3536static __init void event_trace_self_tests(void)
3537{
3538 struct trace_subsystem_dir *dir;
3539 struct trace_event_file *file;
3540 struct trace_event_call *call;
3541 struct event_subsystem *system;
3542 struct trace_array *tr;
3543 int ret;
3544
3545 tr = top_trace_array();
3546 if (!tr)
3547 return;
3548
3549 pr_info("Running tests on trace events:\n");
3550
3551 list_for_each_entry(file, &tr->events, list) {
3552
3553 call = file->event_call;
3554
3555 /* Only test those that have a probe */
3556 if (!call->class || !call->class->probe)
3557 continue;
3558
3559/*
3560 * Testing syscall events here is pretty useless, but
3561 * we still do it if configured. But this is time consuming.
3562 * What we really need is a user thread to perform the
3563 * syscalls as we test.
3564 */
3565#ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3566 if (call->class->system &&
3567 strcmp(call->class->system, "syscalls") == 0)
3568 continue;
3569#endif
3570
3571 pr_info("Testing event %s: ", trace_event_name(call));
3572
3573 /*
3574 * If an event is already enabled, someone is using
3575 * it and the self test should not be on.
3576 */
3577 if (file->flags & EVENT_FILE_FL_ENABLED) {
3578 pr_warn("Enabled event during self test!\n");
3579 WARN_ON_ONCE(1);
3580 continue;
3581 }
3582
3583 ftrace_event_enable_disable(file, 1);
3584 event_test_stuff();
3585 ftrace_event_enable_disable(file, 0);
3586
3587 pr_cont("OK\n");
3588 }
3589
3590 /* Now test at the sub system level */
3591
3592 pr_info("Running tests on trace event systems:\n");
3593
3594 list_for_each_entry(dir, &tr->systems, list) {
3595
3596 system = dir->subsystem;
3597
3598 /* the ftrace system is special, skip it */
3599 if (strcmp(system->name, "ftrace") == 0)
3600 continue;
3601
3602 pr_info("Testing event system %s: ", system->name);
3603
3604 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3605 if (WARN_ON_ONCE(ret)) {
3606 pr_warn("error enabling system %s\n",
3607 system->name);
3608 continue;
3609 }
3610
3611 event_test_stuff();
3612
3613 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3614 if (WARN_ON_ONCE(ret)) {
3615 pr_warn("error disabling system %s\n",
3616 system->name);
3617 continue;
3618 }
3619
3620 pr_cont("OK\n");
3621 }
3622
3623 /* Test with all events enabled */
3624
3625 pr_info("Running tests on all trace events:\n");
3626 pr_info("Testing all events: ");
3627
3628 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3629 if (WARN_ON_ONCE(ret)) {
3630 pr_warn("error enabling all events\n");
3631 return;
3632 }
3633
3634 event_test_stuff();
3635
3636 /* reset sysname */
3637 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3638 if (WARN_ON_ONCE(ret)) {
3639 pr_warn("error disabling all events\n");
3640 return;
3641 }
3642
3643 pr_cont("OK\n");
3644}
3645
3646#ifdef CONFIG_FUNCTION_TRACER
3647
3648static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3649
3650static struct trace_event_file event_trace_file __initdata;
3651
3652static void __init
3653function_test_events_call(unsigned long ip, unsigned long parent_ip,
3654 struct ftrace_ops *op, struct pt_regs *pt_regs)
3655{
3656 struct trace_buffer *buffer;
3657 struct ring_buffer_event *event;
3658 struct ftrace_entry *entry;
3659 unsigned long flags;
3660 long disabled;
3661 int cpu;
3662 int pc;
3663
3664 pc = preempt_count();
3665 preempt_disable_notrace();
3666 cpu = raw_smp_processor_id();
3667 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3668
3669 if (disabled != 1)
3670 goto out;
3671
3672 local_save_flags(flags);
3673
3674 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
3675 TRACE_FN, sizeof(*entry),
3676 flags, pc);
3677 if (!event)
3678 goto out;
3679 entry = ring_buffer_event_data(event);
3680 entry->ip = ip;
3681 entry->parent_ip = parent_ip;
3682
3683 event_trigger_unlock_commit(&event_trace_file, buffer, event,
3684 entry, flags, pc);
3685 out:
3686 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3687 preempt_enable_notrace();
3688}
3689
3690static struct ftrace_ops trace_ops __initdata =
3691{
3692 .func = function_test_events_call,
3693 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
3694};
3695
3696static __init void event_trace_self_test_with_function(void)
3697{
3698 int ret;
3699
3700 event_trace_file.tr = top_trace_array();
3701 if (WARN_ON(!event_trace_file.tr))
3702 return;
3703
3704 ret = register_ftrace_function(&trace_ops);
3705 if (WARN_ON(ret < 0)) {
3706 pr_info("Failed to enable function tracer for event tests\n");
3707 return;
3708 }
3709 pr_info("Running tests again, along with the function tracer\n");
3710 event_trace_self_tests();
3711 unregister_ftrace_function(&trace_ops);
3712}
3713#else
3714static __init void event_trace_self_test_with_function(void)
3715{
3716}
3717#endif
3718
3719static __init int event_trace_self_tests_init(void)
3720{
3721 if (!tracing_selftest_disabled) {
3722 event_trace_self_tests();
3723 event_trace_self_test_with_function();
3724 }
3725
3726 return 0;
3727}
3728
3729late_initcall(event_trace_self_tests_init);
3730
3731#endif