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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/*
2 * event tracer
3 *
4 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
5 *
6 * - Added format output of fields of the trace point.
7 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
8 *
9 */
10
11#include <linux/workqueue.h>
12#include <linux/spinlock.h>
13#include <linux/kthread.h>
14#include <linux/debugfs.h>
15#include <linux/uaccess.h>
16#include <linux/module.h>
17#include <linux/ctype.h>
18#include <linux/slab.h>
19#include <linux/delay.h>
20
21#include <asm/setup.h>
22
23#include "trace_output.h"
24
25#undef TRACE_SYSTEM
26#define TRACE_SYSTEM "TRACE_SYSTEM"
27
28DEFINE_MUTEX(event_mutex);
29
30DEFINE_MUTEX(event_storage_mutex);
31EXPORT_SYMBOL_GPL(event_storage_mutex);
32
33char event_storage[EVENT_STORAGE_SIZE];
34EXPORT_SYMBOL_GPL(event_storage);
35
36LIST_HEAD(ftrace_events);
37LIST_HEAD(ftrace_common_fields);
38
39struct list_head *
40trace_get_fields(struct ftrace_event_call *event_call)
41{
42 if (!event_call->class->get_fields)
43 return &event_call->class->fields;
44 return event_call->class->get_fields(event_call);
45}
46
47static int __trace_define_field(struct list_head *head, const char *type,
48 const char *name, int offset, int size,
49 int is_signed, int filter_type)
50{
51 struct ftrace_event_field *field;
52
53 field = kzalloc(sizeof(*field), GFP_KERNEL);
54 if (!field)
55 goto err;
56
57 field->name = kstrdup(name, GFP_KERNEL);
58 if (!field->name)
59 goto err;
60
61 field->type = kstrdup(type, GFP_KERNEL);
62 if (!field->type)
63 goto err;
64
65 if (filter_type == FILTER_OTHER)
66 field->filter_type = filter_assign_type(type);
67 else
68 field->filter_type = filter_type;
69
70 field->offset = offset;
71 field->size = size;
72 field->is_signed = is_signed;
73
74 list_add(&field->link, head);
75
76 return 0;
77
78err:
79 if (field)
80 kfree(field->name);
81 kfree(field);
82
83 return -ENOMEM;
84}
85
86int trace_define_field(struct ftrace_event_call *call, const char *type,
87 const char *name, int offset, int size, int is_signed,
88 int filter_type)
89{
90 struct list_head *head;
91
92 if (WARN_ON(!call->class))
93 return 0;
94
95 head = trace_get_fields(call);
96 return __trace_define_field(head, type, name, offset, size,
97 is_signed, filter_type);
98}
99EXPORT_SYMBOL_GPL(trace_define_field);
100
101#define __common_field(type, item) \
102 ret = __trace_define_field(&ftrace_common_fields, #type, \
103 "common_" #item, \
104 offsetof(typeof(ent), item), \
105 sizeof(ent.item), \
106 is_signed_type(type), FILTER_OTHER); \
107 if (ret) \
108 return ret;
109
110static int trace_define_common_fields(void)
111{
112 int ret;
113 struct trace_entry ent;
114
115 __common_field(unsigned short, type);
116 __common_field(unsigned char, flags);
117 __common_field(unsigned char, preempt_count);
118 __common_field(int, pid);
119 __common_field(int, padding);
120
121 return ret;
122}
123
124void trace_destroy_fields(struct ftrace_event_call *call)
125{
126 struct ftrace_event_field *field, *next;
127 struct list_head *head;
128
129 head = trace_get_fields(call);
130 list_for_each_entry_safe(field, next, head, link) {
131 list_del(&field->link);
132 kfree(field->type);
133 kfree(field->name);
134 kfree(field);
135 }
136}
137
138int trace_event_raw_init(struct ftrace_event_call *call)
139{
140 int id;
141
142 id = register_ftrace_event(&call->event);
143 if (!id)
144 return -ENODEV;
145
146 return 0;
147}
148EXPORT_SYMBOL_GPL(trace_event_raw_init);
149
150int ftrace_event_reg(struct ftrace_event_call *call,
151 enum trace_reg type, void *data)
152{
153 switch (type) {
154 case TRACE_REG_REGISTER:
155 return tracepoint_probe_register(call->name,
156 call->class->probe,
157 call);
158 case TRACE_REG_UNREGISTER:
159 tracepoint_probe_unregister(call->name,
160 call->class->probe,
161 call);
162 return 0;
163
164#ifdef CONFIG_PERF_EVENTS
165 case TRACE_REG_PERF_REGISTER:
166 return tracepoint_probe_register(call->name,
167 call->class->perf_probe,
168 call);
169 case TRACE_REG_PERF_UNREGISTER:
170 tracepoint_probe_unregister(call->name,
171 call->class->perf_probe,
172 call);
173 return 0;
174 case TRACE_REG_PERF_OPEN:
175 case TRACE_REG_PERF_CLOSE:
176 case TRACE_REG_PERF_ADD:
177 case TRACE_REG_PERF_DEL:
178 return 0;
179#endif
180 }
181 return 0;
182}
183EXPORT_SYMBOL_GPL(ftrace_event_reg);
184
185void trace_event_enable_cmd_record(bool enable)
186{
187 struct ftrace_event_call *call;
188
189 mutex_lock(&event_mutex);
190 list_for_each_entry(call, &ftrace_events, list) {
191 if (!(call->flags & TRACE_EVENT_FL_ENABLED))
192 continue;
193
194 if (enable) {
195 tracing_start_cmdline_record();
196 call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
197 } else {
198 tracing_stop_cmdline_record();
199 call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
200 }
201 }
202 mutex_unlock(&event_mutex);
203}
204
205static int ftrace_event_enable_disable(struct ftrace_event_call *call,
206 int enable)
207{
208 int ret = 0;
209
210 switch (enable) {
211 case 0:
212 if (call->flags & TRACE_EVENT_FL_ENABLED) {
213 call->flags &= ~TRACE_EVENT_FL_ENABLED;
214 if (call->flags & TRACE_EVENT_FL_RECORDED_CMD) {
215 tracing_stop_cmdline_record();
216 call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
217 }
218 call->class->reg(call, TRACE_REG_UNREGISTER, NULL);
219 }
220 break;
221 case 1:
222 if (!(call->flags & TRACE_EVENT_FL_ENABLED)) {
223 if (trace_flags & TRACE_ITER_RECORD_CMD) {
224 tracing_start_cmdline_record();
225 call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
226 }
227 ret = call->class->reg(call, TRACE_REG_REGISTER, NULL);
228 if (ret) {
229 tracing_stop_cmdline_record();
230 pr_info("event trace: Could not enable event "
231 "%s\n", call->name);
232 break;
233 }
234 call->flags |= TRACE_EVENT_FL_ENABLED;
235 }
236 break;
237 }
238
239 return ret;
240}
241
242static void ftrace_clear_events(void)
243{
244 struct ftrace_event_call *call;
245
246 mutex_lock(&event_mutex);
247 list_for_each_entry(call, &ftrace_events, list) {
248 ftrace_event_enable_disable(call, 0);
249 }
250 mutex_unlock(&event_mutex);
251}
252
253static void __put_system(struct event_subsystem *system)
254{
255 struct event_filter *filter = system->filter;
256
257 WARN_ON_ONCE(system->ref_count == 0);
258 if (--system->ref_count)
259 return;
260
261 if (filter) {
262 kfree(filter->filter_string);
263 kfree(filter);
264 }
265 kfree(system->name);
266 kfree(system);
267}
268
269static void __get_system(struct event_subsystem *system)
270{
271 WARN_ON_ONCE(system->ref_count == 0);
272 system->ref_count++;
273}
274
275static void put_system(struct event_subsystem *system)
276{
277 mutex_lock(&event_mutex);
278 __put_system(system);
279 mutex_unlock(&event_mutex);
280}
281
282/*
283 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
284 */
285static int __ftrace_set_clr_event(const char *match, const char *sub,
286 const char *event, int set)
287{
288 struct ftrace_event_call *call;
289 int ret = -EINVAL;
290
291 mutex_lock(&event_mutex);
292 list_for_each_entry(call, &ftrace_events, list) {
293
294 if (!call->name || !call->class || !call->class->reg)
295 continue;
296
297 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
298 continue;
299
300 if (match &&
301 strcmp(match, call->name) != 0 &&
302 strcmp(match, call->class->system) != 0)
303 continue;
304
305 if (sub && strcmp(sub, call->class->system) != 0)
306 continue;
307
308 if (event && strcmp(event, call->name) != 0)
309 continue;
310
311 ftrace_event_enable_disable(call, set);
312
313 ret = 0;
314 }
315 mutex_unlock(&event_mutex);
316
317 return ret;
318}
319
320static int ftrace_set_clr_event(char *buf, int set)
321{
322 char *event = NULL, *sub = NULL, *match;
323
324 /*
325 * The buf format can be <subsystem>:<event-name>
326 * *:<event-name> means any event by that name.
327 * :<event-name> is the same.
328 *
329 * <subsystem>:* means all events in that subsystem
330 * <subsystem>: means the same.
331 *
332 * <name> (no ':') means all events in a subsystem with
333 * the name <name> or any event that matches <name>
334 */
335
336 match = strsep(&buf, ":");
337 if (buf) {
338 sub = match;
339 event = buf;
340 match = NULL;
341
342 if (!strlen(sub) || strcmp(sub, "*") == 0)
343 sub = NULL;
344 if (!strlen(event) || strcmp(event, "*") == 0)
345 event = NULL;
346 }
347
348 return __ftrace_set_clr_event(match, sub, event, set);
349}
350
351/**
352 * trace_set_clr_event - enable or disable an event
353 * @system: system name to match (NULL for any system)
354 * @event: event name to match (NULL for all events, within system)
355 * @set: 1 to enable, 0 to disable
356 *
357 * This is a way for other parts of the kernel to enable or disable
358 * event recording.
359 *
360 * Returns 0 on success, -EINVAL if the parameters do not match any
361 * registered events.
362 */
363int trace_set_clr_event(const char *system, const char *event, int set)
364{
365 return __ftrace_set_clr_event(NULL, system, event, set);
366}
367EXPORT_SYMBOL_GPL(trace_set_clr_event);
368
369/* 128 should be much more than enough */
370#define EVENT_BUF_SIZE 127
371
372static ssize_t
373ftrace_event_write(struct file *file, const char __user *ubuf,
374 size_t cnt, loff_t *ppos)
375{
376 struct trace_parser parser;
377 ssize_t read, ret;
378
379 if (!cnt)
380 return 0;
381
382 ret = tracing_update_buffers();
383 if (ret < 0)
384 return ret;
385
386 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
387 return -ENOMEM;
388
389 read = trace_get_user(&parser, ubuf, cnt, ppos);
390
391 if (read >= 0 && trace_parser_loaded((&parser))) {
392 int set = 1;
393
394 if (*parser.buffer == '!')
395 set = 0;
396
397 parser.buffer[parser.idx] = 0;
398
399 ret = ftrace_set_clr_event(parser.buffer + !set, set);
400 if (ret)
401 goto out_put;
402 }
403
404 ret = read;
405
406 out_put:
407 trace_parser_put(&parser);
408
409 return ret;
410}
411
412static void *
413t_next(struct seq_file *m, void *v, loff_t *pos)
414{
415 struct ftrace_event_call *call = v;
416
417 (*pos)++;
418
419 list_for_each_entry_continue(call, &ftrace_events, list) {
420 /*
421 * The ftrace subsystem is for showing formats only.
422 * They can not be enabled or disabled via the event files.
423 */
424 if (call->class && call->class->reg)
425 return call;
426 }
427
428 return NULL;
429}
430
431static void *t_start(struct seq_file *m, loff_t *pos)
432{
433 struct ftrace_event_call *call;
434 loff_t l;
435
436 mutex_lock(&event_mutex);
437
438 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
439 for (l = 0; l <= *pos; ) {
440 call = t_next(m, call, &l);
441 if (!call)
442 break;
443 }
444 return call;
445}
446
447static void *
448s_next(struct seq_file *m, void *v, loff_t *pos)
449{
450 struct ftrace_event_call *call = v;
451
452 (*pos)++;
453
454 list_for_each_entry_continue(call, &ftrace_events, list) {
455 if (call->flags & TRACE_EVENT_FL_ENABLED)
456 return call;
457 }
458
459 return NULL;
460}
461
462static void *s_start(struct seq_file *m, loff_t *pos)
463{
464 struct ftrace_event_call *call;
465 loff_t l;
466
467 mutex_lock(&event_mutex);
468
469 call = list_entry(&ftrace_events, struct ftrace_event_call, list);
470 for (l = 0; l <= *pos; ) {
471 call = s_next(m, call, &l);
472 if (!call)
473 break;
474 }
475 return call;
476}
477
478static int t_show(struct seq_file *m, void *v)
479{
480 struct ftrace_event_call *call = v;
481
482 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
483 seq_printf(m, "%s:", call->class->system);
484 seq_printf(m, "%s\n", call->name);
485
486 return 0;
487}
488
489static void t_stop(struct seq_file *m, void *p)
490{
491 mutex_unlock(&event_mutex);
492}
493
494static int
495ftrace_event_seq_open(struct inode *inode, struct file *file)
496{
497 const struct seq_operations *seq_ops;
498
499 if ((file->f_mode & FMODE_WRITE) &&
500 (file->f_flags & O_TRUNC))
501 ftrace_clear_events();
502
503 seq_ops = inode->i_private;
504 return seq_open(file, seq_ops);
505}
506
507static ssize_t
508event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
509 loff_t *ppos)
510{
511 struct ftrace_event_call *call = filp->private_data;
512 char *buf;
513
514 if (call->flags & TRACE_EVENT_FL_ENABLED)
515 buf = "1\n";
516 else
517 buf = "0\n";
518
519 return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
520}
521
522static ssize_t
523event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
524 loff_t *ppos)
525{
526 struct ftrace_event_call *call = filp->private_data;
527 unsigned long val;
528 int ret;
529
530 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
531 if (ret)
532 return ret;
533
534 ret = tracing_update_buffers();
535 if (ret < 0)
536 return ret;
537
538 switch (val) {
539 case 0:
540 case 1:
541 mutex_lock(&event_mutex);
542 ret = ftrace_event_enable_disable(call, val);
543 mutex_unlock(&event_mutex);
544 break;
545
546 default:
547 return -EINVAL;
548 }
549
550 *ppos += cnt;
551
552 return ret ? ret : cnt;
553}
554
555static ssize_t
556system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
557 loff_t *ppos)
558{
559 const char set_to_char[4] = { '?', '0', '1', 'X' };
560 struct event_subsystem *system = filp->private_data;
561 struct ftrace_event_call *call;
562 char buf[2];
563 int set = 0;
564 int ret;
565
566 mutex_lock(&event_mutex);
567 list_for_each_entry(call, &ftrace_events, list) {
568 if (!call->name || !call->class || !call->class->reg)
569 continue;
570
571 if (system && strcmp(call->class->system, system->name) != 0)
572 continue;
573
574 /*
575 * We need to find out if all the events are set
576 * or if all events or cleared, or if we have
577 * a mixture.
578 */
579 set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED));
580
581 /*
582 * If we have a mixture, no need to look further.
583 */
584 if (set == 3)
585 break;
586 }
587 mutex_unlock(&event_mutex);
588
589 buf[0] = set_to_char[set];
590 buf[1] = '\n';
591
592 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
593
594 return ret;
595}
596
597static ssize_t
598system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
599 loff_t *ppos)
600{
601 struct event_subsystem *system = filp->private_data;
602 const char *name = NULL;
603 unsigned long val;
604 ssize_t ret;
605
606 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
607 if (ret)
608 return ret;
609
610 ret = tracing_update_buffers();
611 if (ret < 0)
612 return ret;
613
614 if (val != 0 && val != 1)
615 return -EINVAL;
616
617 /*
618 * Opening of "enable" adds a ref count to system,
619 * so the name is safe to use.
620 */
621 if (system)
622 name = system->name;
623
624 ret = __ftrace_set_clr_event(NULL, name, NULL, val);
625 if (ret)
626 goto out;
627
628 ret = cnt;
629
630out:
631 *ppos += cnt;
632
633 return ret;
634}
635
636enum {
637 FORMAT_HEADER = 1,
638 FORMAT_FIELD_SEPERATOR = 2,
639 FORMAT_PRINTFMT = 3,
640};
641
642static void *f_next(struct seq_file *m, void *v, loff_t *pos)
643{
644 struct ftrace_event_call *call = m->private;
645 struct ftrace_event_field *field;
646 struct list_head *common_head = &ftrace_common_fields;
647 struct list_head *head = trace_get_fields(call);
648
649 (*pos)++;
650
651 switch ((unsigned long)v) {
652 case FORMAT_HEADER:
653 if (unlikely(list_empty(common_head)))
654 return NULL;
655
656 field = list_entry(common_head->prev,
657 struct ftrace_event_field, link);
658 return field;
659
660 case FORMAT_FIELD_SEPERATOR:
661 if (unlikely(list_empty(head)))
662 return NULL;
663
664 field = list_entry(head->prev, struct ftrace_event_field, link);
665 return field;
666
667 case FORMAT_PRINTFMT:
668 /* all done */
669 return NULL;
670 }
671
672 field = v;
673 if (field->link.prev == common_head)
674 return (void *)FORMAT_FIELD_SEPERATOR;
675 else if (field->link.prev == head)
676 return (void *)FORMAT_PRINTFMT;
677
678 field = list_entry(field->link.prev, struct ftrace_event_field, link);
679
680 return field;
681}
682
683static void *f_start(struct seq_file *m, loff_t *pos)
684{
685 loff_t l = 0;
686 void *p;
687
688 /* Start by showing the header */
689 if (!*pos)
690 return (void *)FORMAT_HEADER;
691
692 p = (void *)FORMAT_HEADER;
693 do {
694 p = f_next(m, p, &l);
695 } while (p && l < *pos);
696
697 return p;
698}
699
700static int f_show(struct seq_file *m, void *v)
701{
702 struct ftrace_event_call *call = m->private;
703 struct ftrace_event_field *field;
704 const char *array_descriptor;
705
706 switch ((unsigned long)v) {
707 case FORMAT_HEADER:
708 seq_printf(m, "name: %s\n", call->name);
709 seq_printf(m, "ID: %d\n", call->event.type);
710 seq_printf(m, "format:\n");
711 return 0;
712
713 case FORMAT_FIELD_SEPERATOR:
714 seq_putc(m, '\n');
715 return 0;
716
717 case FORMAT_PRINTFMT:
718 seq_printf(m, "\nprint fmt: %s\n",
719 call->print_fmt);
720 return 0;
721 }
722
723 field = v;
724
725 /*
726 * Smartly shows the array type(except dynamic array).
727 * Normal:
728 * field:TYPE VAR
729 * If TYPE := TYPE[LEN], it is shown:
730 * field:TYPE VAR[LEN]
731 */
732 array_descriptor = strchr(field->type, '[');
733
734 if (!strncmp(field->type, "__data_loc", 10))
735 array_descriptor = NULL;
736
737 if (!array_descriptor)
738 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
739 field->type, field->name, field->offset,
740 field->size, !!field->is_signed);
741 else
742 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
743 (int)(array_descriptor - field->type),
744 field->type, field->name,
745 array_descriptor, field->offset,
746 field->size, !!field->is_signed);
747
748 return 0;
749}
750
751static void f_stop(struct seq_file *m, void *p)
752{
753}
754
755static const struct seq_operations trace_format_seq_ops = {
756 .start = f_start,
757 .next = f_next,
758 .stop = f_stop,
759 .show = f_show,
760};
761
762static int trace_format_open(struct inode *inode, struct file *file)
763{
764 struct ftrace_event_call *call = inode->i_private;
765 struct seq_file *m;
766 int ret;
767
768 ret = seq_open(file, &trace_format_seq_ops);
769 if (ret < 0)
770 return ret;
771
772 m = file->private_data;
773 m->private = call;
774
775 return 0;
776}
777
778static ssize_t
779event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
780{
781 struct ftrace_event_call *call = filp->private_data;
782 struct trace_seq *s;
783 int r;
784
785 if (*ppos)
786 return 0;
787
788 s = kmalloc(sizeof(*s), GFP_KERNEL);
789 if (!s)
790 return -ENOMEM;
791
792 trace_seq_init(s);
793 trace_seq_printf(s, "%d\n", call->event.type);
794
795 r = simple_read_from_buffer(ubuf, cnt, ppos,
796 s->buffer, s->len);
797 kfree(s);
798 return r;
799}
800
801static ssize_t
802event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
803 loff_t *ppos)
804{
805 struct ftrace_event_call *call = filp->private_data;
806 struct trace_seq *s;
807 int r;
808
809 if (*ppos)
810 return 0;
811
812 s = kmalloc(sizeof(*s), GFP_KERNEL);
813 if (!s)
814 return -ENOMEM;
815
816 trace_seq_init(s);
817
818 print_event_filter(call, s);
819 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
820
821 kfree(s);
822
823 return r;
824}
825
826static ssize_t
827event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
828 loff_t *ppos)
829{
830 struct ftrace_event_call *call = filp->private_data;
831 char *buf;
832 int err;
833
834 if (cnt >= PAGE_SIZE)
835 return -EINVAL;
836
837 buf = (char *)__get_free_page(GFP_TEMPORARY);
838 if (!buf)
839 return -ENOMEM;
840
841 if (copy_from_user(buf, ubuf, cnt)) {
842 free_page((unsigned long) buf);
843 return -EFAULT;
844 }
845 buf[cnt] = '\0';
846
847 err = apply_event_filter(call, buf);
848 free_page((unsigned long) buf);
849 if (err < 0)
850 return err;
851
852 *ppos += cnt;
853
854 return cnt;
855}
856
857static LIST_HEAD(event_subsystems);
858
859static int subsystem_open(struct inode *inode, struct file *filp)
860{
861 struct event_subsystem *system = NULL;
862 int ret;
863
864 if (!inode->i_private)
865 goto skip_search;
866
867 /* Make sure the system still exists */
868 mutex_lock(&event_mutex);
869 list_for_each_entry(system, &event_subsystems, list) {
870 if (system == inode->i_private) {
871 /* Don't open systems with no events */
872 if (!system->nr_events) {
873 system = NULL;
874 break;
875 }
876 __get_system(system);
877 break;
878 }
879 }
880 mutex_unlock(&event_mutex);
881
882 if (system != inode->i_private)
883 return -ENODEV;
884
885 skip_search:
886 ret = tracing_open_generic(inode, filp);
887 if (ret < 0 && system)
888 put_system(system);
889
890 return ret;
891}
892
893static int subsystem_release(struct inode *inode, struct file *file)
894{
895 struct event_subsystem *system = inode->i_private;
896
897 if (system)
898 put_system(system);
899
900 return 0;
901}
902
903static ssize_t
904subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
905 loff_t *ppos)
906{
907 struct event_subsystem *system = filp->private_data;
908 struct trace_seq *s;
909 int r;
910
911 if (*ppos)
912 return 0;
913
914 s = kmalloc(sizeof(*s), GFP_KERNEL);
915 if (!s)
916 return -ENOMEM;
917
918 trace_seq_init(s);
919
920 print_subsystem_event_filter(system, s);
921 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
922
923 kfree(s);
924
925 return r;
926}
927
928static ssize_t
929subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
930 loff_t *ppos)
931{
932 struct event_subsystem *system = filp->private_data;
933 char *buf;
934 int err;
935
936 if (cnt >= PAGE_SIZE)
937 return -EINVAL;
938
939 buf = (char *)__get_free_page(GFP_TEMPORARY);
940 if (!buf)
941 return -ENOMEM;
942
943 if (copy_from_user(buf, ubuf, cnt)) {
944 free_page((unsigned long) buf);
945 return -EFAULT;
946 }
947 buf[cnt] = '\0';
948
949 err = apply_subsystem_event_filter(system, buf);
950 free_page((unsigned long) buf);
951 if (err < 0)
952 return err;
953
954 *ppos += cnt;
955
956 return cnt;
957}
958
959static ssize_t
960show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
961{
962 int (*func)(struct trace_seq *s) = filp->private_data;
963 struct trace_seq *s;
964 int r;
965
966 if (*ppos)
967 return 0;
968
969 s = kmalloc(sizeof(*s), GFP_KERNEL);
970 if (!s)
971 return -ENOMEM;
972
973 trace_seq_init(s);
974
975 func(s);
976 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
977
978 kfree(s);
979
980 return r;
981}
982
983static const struct seq_operations show_event_seq_ops = {
984 .start = t_start,
985 .next = t_next,
986 .show = t_show,
987 .stop = t_stop,
988};
989
990static const struct seq_operations show_set_event_seq_ops = {
991 .start = s_start,
992 .next = s_next,
993 .show = t_show,
994 .stop = t_stop,
995};
996
997static const struct file_operations ftrace_avail_fops = {
998 .open = ftrace_event_seq_open,
999 .read = seq_read,
1000 .llseek = seq_lseek,
1001 .release = seq_release,
1002};
1003
1004static const struct file_operations ftrace_set_event_fops = {
1005 .open = ftrace_event_seq_open,
1006 .read = seq_read,
1007 .write = ftrace_event_write,
1008 .llseek = seq_lseek,
1009 .release = seq_release,
1010};
1011
1012static const struct file_operations ftrace_enable_fops = {
1013 .open = tracing_open_generic,
1014 .read = event_enable_read,
1015 .write = event_enable_write,
1016 .llseek = default_llseek,
1017};
1018
1019static const struct file_operations ftrace_event_format_fops = {
1020 .open = trace_format_open,
1021 .read = seq_read,
1022 .llseek = seq_lseek,
1023 .release = seq_release,
1024};
1025
1026static const struct file_operations ftrace_event_id_fops = {
1027 .open = tracing_open_generic,
1028 .read = event_id_read,
1029 .llseek = default_llseek,
1030};
1031
1032static const struct file_operations ftrace_event_filter_fops = {
1033 .open = tracing_open_generic,
1034 .read = event_filter_read,
1035 .write = event_filter_write,
1036 .llseek = default_llseek,
1037};
1038
1039static const struct file_operations ftrace_subsystem_filter_fops = {
1040 .open = subsystem_open,
1041 .read = subsystem_filter_read,
1042 .write = subsystem_filter_write,
1043 .llseek = default_llseek,
1044 .release = subsystem_release,
1045};
1046
1047static const struct file_operations ftrace_system_enable_fops = {
1048 .open = subsystem_open,
1049 .read = system_enable_read,
1050 .write = system_enable_write,
1051 .llseek = default_llseek,
1052 .release = subsystem_release,
1053};
1054
1055static const struct file_operations ftrace_show_header_fops = {
1056 .open = tracing_open_generic,
1057 .read = show_header,
1058 .llseek = default_llseek,
1059};
1060
1061static struct dentry *event_trace_events_dir(void)
1062{
1063 static struct dentry *d_tracer;
1064 static struct dentry *d_events;
1065
1066 if (d_events)
1067 return d_events;
1068
1069 d_tracer = tracing_init_dentry();
1070 if (!d_tracer)
1071 return NULL;
1072
1073 d_events = debugfs_create_dir("events", d_tracer);
1074 if (!d_events)
1075 pr_warning("Could not create debugfs "
1076 "'events' directory\n");
1077
1078 return d_events;
1079}
1080
1081static struct dentry *
1082event_subsystem_dir(const char *name, struct dentry *d_events)
1083{
1084 struct event_subsystem *system;
1085 struct dentry *entry;
1086
1087 /* First see if we did not already create this dir */
1088 list_for_each_entry(system, &event_subsystems, list) {
1089 if (strcmp(system->name, name) == 0) {
1090 system->nr_events++;
1091 return system->entry;
1092 }
1093 }
1094
1095 /* need to create new entry */
1096 system = kmalloc(sizeof(*system), GFP_KERNEL);
1097 if (!system) {
1098 pr_warning("No memory to create event subsystem %s\n",
1099 name);
1100 return d_events;
1101 }
1102
1103 system->entry = debugfs_create_dir(name, d_events);
1104 if (!system->entry) {
1105 pr_warning("Could not create event subsystem %s\n",
1106 name);
1107 kfree(system);
1108 return d_events;
1109 }
1110
1111 system->nr_events = 1;
1112 system->ref_count = 1;
1113 system->name = kstrdup(name, GFP_KERNEL);
1114 if (!system->name) {
1115 debugfs_remove(system->entry);
1116 kfree(system);
1117 return d_events;
1118 }
1119
1120 list_add(&system->list, &event_subsystems);
1121
1122 system->filter = NULL;
1123
1124 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1125 if (!system->filter) {
1126 pr_warning("Could not allocate filter for subsystem "
1127 "'%s'\n", name);
1128 return system->entry;
1129 }
1130
1131 entry = debugfs_create_file("filter", 0644, system->entry, system,
1132 &ftrace_subsystem_filter_fops);
1133 if (!entry) {
1134 kfree(system->filter);
1135 system->filter = NULL;
1136 pr_warning("Could not create debugfs "
1137 "'%s/filter' entry\n", name);
1138 }
1139
1140 trace_create_file("enable", 0644, system->entry, system,
1141 &ftrace_system_enable_fops);
1142
1143 return system->entry;
1144}
1145
1146static int
1147event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
1148 const struct file_operations *id,
1149 const struct file_operations *enable,
1150 const struct file_operations *filter,
1151 const struct file_operations *format)
1152{
1153 struct list_head *head;
1154 int ret;
1155
1156 /*
1157 * If the trace point header did not define TRACE_SYSTEM
1158 * then the system would be called "TRACE_SYSTEM".
1159 */
1160 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1161 d_events = event_subsystem_dir(call->class->system, d_events);
1162
1163 call->dir = debugfs_create_dir(call->name, d_events);
1164 if (!call->dir) {
1165 pr_warning("Could not create debugfs "
1166 "'%s' directory\n", call->name);
1167 return -1;
1168 }
1169
1170 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1171 trace_create_file("enable", 0644, call->dir, call,
1172 enable);
1173
1174#ifdef CONFIG_PERF_EVENTS
1175 if (call->event.type && call->class->reg)
1176 trace_create_file("id", 0444, call->dir, call,
1177 id);
1178#endif
1179
1180 /*
1181 * Other events may have the same class. Only update
1182 * the fields if they are not already defined.
1183 */
1184 head = trace_get_fields(call);
1185 if (list_empty(head)) {
1186 ret = call->class->define_fields(call);
1187 if (ret < 0) {
1188 pr_warning("Could not initialize trace point"
1189 " events/%s\n", call->name);
1190 return ret;
1191 }
1192 }
1193 trace_create_file("filter", 0644, call->dir, call,
1194 filter);
1195
1196 trace_create_file("format", 0444, call->dir, call,
1197 format);
1198
1199 return 0;
1200}
1201
1202static int
1203__trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
1204 const struct file_operations *id,
1205 const struct file_operations *enable,
1206 const struct file_operations *filter,
1207 const struct file_operations *format)
1208{
1209 struct dentry *d_events;
1210 int ret;
1211
1212 /* The linker may leave blanks */
1213 if (!call->name)
1214 return -EINVAL;
1215
1216 if (call->class->raw_init) {
1217 ret = call->class->raw_init(call);
1218 if (ret < 0) {
1219 if (ret != -ENOSYS)
1220 pr_warning("Could not initialize trace events/%s\n",
1221 call->name);
1222 return ret;
1223 }
1224 }
1225
1226 d_events = event_trace_events_dir();
1227 if (!d_events)
1228 return -ENOENT;
1229
1230 ret = event_create_dir(call, d_events, id, enable, filter, format);
1231 if (!ret)
1232 list_add(&call->list, &ftrace_events);
1233 call->mod = mod;
1234
1235 return ret;
1236}
1237
1238/* Add an additional event_call dynamically */
1239int trace_add_event_call(struct ftrace_event_call *call)
1240{
1241 int ret;
1242 mutex_lock(&event_mutex);
1243 ret = __trace_add_event_call(call, NULL, &ftrace_event_id_fops,
1244 &ftrace_enable_fops,
1245 &ftrace_event_filter_fops,
1246 &ftrace_event_format_fops);
1247 mutex_unlock(&event_mutex);
1248 return ret;
1249}
1250
1251static void remove_subsystem_dir(const char *name)
1252{
1253 struct event_subsystem *system;
1254
1255 if (strcmp(name, TRACE_SYSTEM) == 0)
1256 return;
1257
1258 list_for_each_entry(system, &event_subsystems, list) {
1259 if (strcmp(system->name, name) == 0) {
1260 if (!--system->nr_events) {
1261 debugfs_remove_recursive(system->entry);
1262 list_del(&system->list);
1263 __put_system(system);
1264 }
1265 break;
1266 }
1267 }
1268}
1269
1270/*
1271 * Must be called under locking both of event_mutex and trace_event_mutex.
1272 */
1273static void __trace_remove_event_call(struct ftrace_event_call *call)
1274{
1275 ftrace_event_enable_disable(call, 0);
1276 if (call->event.funcs)
1277 __unregister_ftrace_event(&call->event);
1278 debugfs_remove_recursive(call->dir);
1279 list_del(&call->list);
1280 trace_destroy_fields(call);
1281 destroy_preds(call);
1282 remove_subsystem_dir(call->class->system);
1283}
1284
1285/* Remove an event_call */
1286void trace_remove_event_call(struct ftrace_event_call *call)
1287{
1288 mutex_lock(&event_mutex);
1289 down_write(&trace_event_mutex);
1290 __trace_remove_event_call(call);
1291 up_write(&trace_event_mutex);
1292 mutex_unlock(&event_mutex);
1293}
1294
1295#define for_each_event(event, start, end) \
1296 for (event = start; \
1297 (unsigned long)event < (unsigned long)end; \
1298 event++)
1299
1300#ifdef CONFIG_MODULES
1301
1302static LIST_HEAD(ftrace_module_file_list);
1303
1304/*
1305 * Modules must own their file_operations to keep up with
1306 * reference counting.
1307 */
1308struct ftrace_module_file_ops {
1309 struct list_head list;
1310 struct module *mod;
1311 struct file_operations id;
1312 struct file_operations enable;
1313 struct file_operations format;
1314 struct file_operations filter;
1315};
1316
1317static struct ftrace_module_file_ops *
1318trace_create_file_ops(struct module *mod)
1319{
1320 struct ftrace_module_file_ops *file_ops;
1321
1322 /*
1323 * This is a bit of a PITA. To allow for correct reference
1324 * counting, modules must "own" their file_operations.
1325 * To do this, we allocate the file operations that will be
1326 * used in the event directory.
1327 */
1328
1329 file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1330 if (!file_ops)
1331 return NULL;
1332
1333 file_ops->mod = mod;
1334
1335 file_ops->id = ftrace_event_id_fops;
1336 file_ops->id.owner = mod;
1337
1338 file_ops->enable = ftrace_enable_fops;
1339 file_ops->enable.owner = mod;
1340
1341 file_ops->filter = ftrace_event_filter_fops;
1342 file_ops->filter.owner = mod;
1343
1344 file_ops->format = ftrace_event_format_fops;
1345 file_ops->format.owner = mod;
1346
1347 list_add(&file_ops->list, &ftrace_module_file_list);
1348
1349 return file_ops;
1350}
1351
1352static void trace_module_add_events(struct module *mod)
1353{
1354 struct ftrace_module_file_ops *file_ops = NULL;
1355 struct ftrace_event_call **call, **start, **end;
1356
1357 start = mod->trace_events;
1358 end = mod->trace_events + mod->num_trace_events;
1359
1360 if (start == end)
1361 return;
1362
1363 file_ops = trace_create_file_ops(mod);
1364 if (!file_ops)
1365 return;
1366
1367 for_each_event(call, start, end) {
1368 __trace_add_event_call(*call, mod,
1369 &file_ops->id, &file_ops->enable,
1370 &file_ops->filter, &file_ops->format);
1371 }
1372}
1373
1374static void trace_module_remove_events(struct module *mod)
1375{
1376 struct ftrace_module_file_ops *file_ops;
1377 struct ftrace_event_call *call, *p;
1378 bool found = false;
1379
1380 down_write(&trace_event_mutex);
1381 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1382 if (call->mod == mod) {
1383 found = true;
1384 __trace_remove_event_call(call);
1385 }
1386 }
1387
1388 /* Now free the file_operations */
1389 list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1390 if (file_ops->mod == mod)
1391 break;
1392 }
1393 if (&file_ops->list != &ftrace_module_file_list) {
1394 list_del(&file_ops->list);
1395 kfree(file_ops);
1396 }
1397
1398 /*
1399 * It is safest to reset the ring buffer if the module being unloaded
1400 * registered any events.
1401 */
1402 if (found)
1403 tracing_reset_current_online_cpus();
1404 up_write(&trace_event_mutex);
1405}
1406
1407static int trace_module_notify(struct notifier_block *self,
1408 unsigned long val, void *data)
1409{
1410 struct module *mod = data;
1411
1412 mutex_lock(&event_mutex);
1413 switch (val) {
1414 case MODULE_STATE_COMING:
1415 trace_module_add_events(mod);
1416 break;
1417 case MODULE_STATE_GOING:
1418 trace_module_remove_events(mod);
1419 break;
1420 }
1421 mutex_unlock(&event_mutex);
1422
1423 return 0;
1424}
1425#else
1426static int trace_module_notify(struct notifier_block *self,
1427 unsigned long val, void *data)
1428{
1429 return 0;
1430}
1431#endif /* CONFIG_MODULES */
1432
1433static struct notifier_block trace_module_nb = {
1434 .notifier_call = trace_module_notify,
1435 .priority = 0,
1436};
1437
1438extern struct ftrace_event_call *__start_ftrace_events[];
1439extern struct ftrace_event_call *__stop_ftrace_events[];
1440
1441static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1442
1443static __init int setup_trace_event(char *str)
1444{
1445 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1446 ring_buffer_expanded = 1;
1447 tracing_selftest_disabled = 1;
1448
1449 return 1;
1450}
1451__setup("trace_event=", setup_trace_event);
1452
1453static __init int event_trace_init(void)
1454{
1455 struct ftrace_event_call **call;
1456 struct dentry *d_tracer;
1457 struct dentry *entry;
1458 struct dentry *d_events;
1459 int ret;
1460 char *buf = bootup_event_buf;
1461 char *token;
1462
1463 d_tracer = tracing_init_dentry();
1464 if (!d_tracer)
1465 return 0;
1466
1467 entry = debugfs_create_file("available_events", 0444, d_tracer,
1468 (void *)&show_event_seq_ops,
1469 &ftrace_avail_fops);
1470 if (!entry)
1471 pr_warning("Could not create debugfs "
1472 "'available_events' entry\n");
1473
1474 entry = debugfs_create_file("set_event", 0644, d_tracer,
1475 (void *)&show_set_event_seq_ops,
1476 &ftrace_set_event_fops);
1477 if (!entry)
1478 pr_warning("Could not create debugfs "
1479 "'set_event' entry\n");
1480
1481 d_events = event_trace_events_dir();
1482 if (!d_events)
1483 return 0;
1484
1485 /* ring buffer internal formats */
1486 trace_create_file("header_page", 0444, d_events,
1487 ring_buffer_print_page_header,
1488 &ftrace_show_header_fops);
1489
1490 trace_create_file("header_event", 0444, d_events,
1491 ring_buffer_print_entry_header,
1492 &ftrace_show_header_fops);
1493
1494 trace_create_file("enable", 0644, d_events,
1495 NULL, &ftrace_system_enable_fops);
1496
1497 if (trace_define_common_fields())
1498 pr_warning("tracing: Failed to allocate common fields");
1499
1500 for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
1501 __trace_add_event_call(*call, NULL, &ftrace_event_id_fops,
1502 &ftrace_enable_fops,
1503 &ftrace_event_filter_fops,
1504 &ftrace_event_format_fops);
1505 }
1506
1507 while (true) {
1508 token = strsep(&buf, ",");
1509
1510 if (!token)
1511 break;
1512 if (!*token)
1513 continue;
1514
1515 ret = ftrace_set_clr_event(token, 1);
1516 if (ret)
1517 pr_warning("Failed to enable trace event: %s\n", token);
1518 }
1519
1520 ret = register_module_notifier(&trace_module_nb);
1521 if (ret)
1522 pr_warning("Failed to register trace events module notifier\n");
1523
1524 return 0;
1525}
1526fs_initcall(event_trace_init);
1527
1528#ifdef CONFIG_FTRACE_STARTUP_TEST
1529
1530static DEFINE_SPINLOCK(test_spinlock);
1531static DEFINE_SPINLOCK(test_spinlock_irq);
1532static DEFINE_MUTEX(test_mutex);
1533
1534static __init void test_work(struct work_struct *dummy)
1535{
1536 spin_lock(&test_spinlock);
1537 spin_lock_irq(&test_spinlock_irq);
1538 udelay(1);
1539 spin_unlock_irq(&test_spinlock_irq);
1540 spin_unlock(&test_spinlock);
1541
1542 mutex_lock(&test_mutex);
1543 msleep(1);
1544 mutex_unlock(&test_mutex);
1545}
1546
1547static __init int event_test_thread(void *unused)
1548{
1549 void *test_malloc;
1550
1551 test_malloc = kmalloc(1234, GFP_KERNEL);
1552 if (!test_malloc)
1553 pr_info("failed to kmalloc\n");
1554
1555 schedule_on_each_cpu(test_work);
1556
1557 kfree(test_malloc);
1558
1559 set_current_state(TASK_INTERRUPTIBLE);
1560 while (!kthread_should_stop())
1561 schedule();
1562
1563 return 0;
1564}
1565
1566/*
1567 * Do various things that may trigger events.
1568 */
1569static __init void event_test_stuff(void)
1570{
1571 struct task_struct *test_thread;
1572
1573 test_thread = kthread_run(event_test_thread, NULL, "test-events");
1574 msleep(1);
1575 kthread_stop(test_thread);
1576}
1577
1578/*
1579 * For every trace event defined, we will test each trace point separately,
1580 * and then by groups, and finally all trace points.
1581 */
1582static __init void event_trace_self_tests(void)
1583{
1584 struct ftrace_event_call *call;
1585 struct event_subsystem *system;
1586 int ret;
1587
1588 pr_info("Running tests on trace events:\n");
1589
1590 list_for_each_entry(call, &ftrace_events, list) {
1591
1592 /* Only test those that have a probe */
1593 if (!call->class || !call->class->probe)
1594 continue;
1595
1596/*
1597 * Testing syscall events here is pretty useless, but
1598 * we still do it if configured. But this is time consuming.
1599 * What we really need is a user thread to perform the
1600 * syscalls as we test.
1601 */
1602#ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1603 if (call->class->system &&
1604 strcmp(call->class->system, "syscalls") == 0)
1605 continue;
1606#endif
1607
1608 pr_info("Testing event %s: ", call->name);
1609
1610 /*
1611 * If an event is already enabled, someone is using
1612 * it and the self test should not be on.
1613 */
1614 if (call->flags & TRACE_EVENT_FL_ENABLED) {
1615 pr_warning("Enabled event during self test!\n");
1616 WARN_ON_ONCE(1);
1617 continue;
1618 }
1619
1620 ftrace_event_enable_disable(call, 1);
1621 event_test_stuff();
1622 ftrace_event_enable_disable(call, 0);
1623
1624 pr_cont("OK\n");
1625 }
1626
1627 /* Now test at the sub system level */
1628
1629 pr_info("Running tests on trace event systems:\n");
1630
1631 list_for_each_entry(system, &event_subsystems, list) {
1632
1633 /* the ftrace system is special, skip it */
1634 if (strcmp(system->name, "ftrace") == 0)
1635 continue;
1636
1637 pr_info("Testing event system %s: ", system->name);
1638
1639 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1640 if (WARN_ON_ONCE(ret)) {
1641 pr_warning("error enabling system %s\n",
1642 system->name);
1643 continue;
1644 }
1645
1646 event_test_stuff();
1647
1648 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1649 if (WARN_ON_ONCE(ret))
1650 pr_warning("error disabling system %s\n",
1651 system->name);
1652
1653 pr_cont("OK\n");
1654 }
1655
1656 /* Test with all events enabled */
1657
1658 pr_info("Running tests on all trace events:\n");
1659 pr_info("Testing all events: ");
1660
1661 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1662 if (WARN_ON_ONCE(ret)) {
1663 pr_warning("error enabling all events\n");
1664 return;
1665 }
1666
1667 event_test_stuff();
1668
1669 /* reset sysname */
1670 ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1671 if (WARN_ON_ONCE(ret)) {
1672 pr_warning("error disabling all events\n");
1673 return;
1674 }
1675
1676 pr_cont("OK\n");
1677}
1678
1679#ifdef CONFIG_FUNCTION_TRACER
1680
1681static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1682
1683static void
1684function_test_events_call(unsigned long ip, unsigned long parent_ip)
1685{
1686 struct ring_buffer_event *event;
1687 struct ring_buffer *buffer;
1688 struct ftrace_entry *entry;
1689 unsigned long flags;
1690 long disabled;
1691 int cpu;
1692 int pc;
1693
1694 pc = preempt_count();
1695 preempt_disable_notrace();
1696 cpu = raw_smp_processor_id();
1697 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1698
1699 if (disabled != 1)
1700 goto out;
1701
1702 local_save_flags(flags);
1703
1704 event = trace_current_buffer_lock_reserve(&buffer,
1705 TRACE_FN, sizeof(*entry),
1706 flags, pc);
1707 if (!event)
1708 goto out;
1709 entry = ring_buffer_event_data(event);
1710 entry->ip = ip;
1711 entry->parent_ip = parent_ip;
1712
1713 trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
1714
1715 out:
1716 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1717 preempt_enable_notrace();
1718}
1719
1720static struct ftrace_ops trace_ops __initdata =
1721{
1722 .func = function_test_events_call,
1723};
1724
1725static __init void event_trace_self_test_with_function(void)
1726{
1727 int ret;
1728 ret = register_ftrace_function(&trace_ops);
1729 if (WARN_ON(ret < 0)) {
1730 pr_info("Failed to enable function tracer for event tests\n");
1731 return;
1732 }
1733 pr_info("Running tests again, along with the function tracer\n");
1734 event_trace_self_tests();
1735 unregister_ftrace_function(&trace_ops);
1736}
1737#else
1738static __init void event_trace_self_test_with_function(void)
1739{
1740}
1741#endif
1742
1743static __init int event_trace_self_tests_init(void)
1744{
1745 if (!tracing_selftest_disabled) {
1746 event_trace_self_tests();
1747 event_trace_self_test_with_function();
1748 }
1749
1750 return 0;
1751}
1752
1753late_initcall(event_trace_self_tests_init);
1754
1755#endif