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1/*
2 * event tracer
3 *
4 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
5 *
6 * - Added format output of fields of the trace point.
7 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
8 *
9 */
10
11#define pr_fmt(fmt) fmt
12
13#include <linux/workqueue.h>
14#include <linux/spinlock.h>
15#include <linux/kthread.h>
16#include <linux/tracefs.h>
17#include <linux/uaccess.h>
18#include <linux/bsearch.h>
19#include <linux/module.h>
20#include <linux/ctype.h>
21#include <linux/sort.h>
22#include <linux/slab.h>
23#include <linux/delay.h>
24
25#include <trace/events/sched.h>
26
27#include <asm/setup.h>
28
29#include "trace_output.h"
30
31#undef TRACE_SYSTEM
32#define TRACE_SYSTEM "TRACE_SYSTEM"
33
34DEFINE_MUTEX(event_mutex);
35
36LIST_HEAD(ftrace_events);
37static LIST_HEAD(ftrace_generic_fields);
38static LIST_HEAD(ftrace_common_fields);
39
40#define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
41
42static struct kmem_cache *field_cachep;
43static struct kmem_cache *file_cachep;
44
45static inline int system_refcount(struct event_subsystem *system)
46{
47 return system->ref_count;
48}
49
50static int system_refcount_inc(struct event_subsystem *system)
51{
52 return system->ref_count++;
53}
54
55static int system_refcount_dec(struct event_subsystem *system)
56{
57 return --system->ref_count;
58}
59
60/* Double loops, do not use break, only goto's work */
61#define do_for_each_event_file(tr, file) \
62 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
63 list_for_each_entry(file, &tr->events, list)
64
65#define do_for_each_event_file_safe(tr, file) \
66 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
67 struct trace_event_file *___n; \
68 list_for_each_entry_safe(file, ___n, &tr->events, list)
69
70#define while_for_each_event_file() \
71 }
72
73static struct list_head *
74trace_get_fields(struct trace_event_call *event_call)
75{
76 if (!event_call->class->get_fields)
77 return &event_call->class->fields;
78 return event_call->class->get_fields(event_call);
79}
80
81static struct ftrace_event_field *
82__find_event_field(struct list_head *head, char *name)
83{
84 struct ftrace_event_field *field;
85
86 list_for_each_entry(field, head, link) {
87 if (!strcmp(field->name, name))
88 return field;
89 }
90
91 return NULL;
92}
93
94struct ftrace_event_field *
95trace_find_event_field(struct trace_event_call *call, char *name)
96{
97 struct ftrace_event_field *field;
98 struct list_head *head;
99
100 head = trace_get_fields(call);
101 field = __find_event_field(head, name);
102 if (field)
103 return field;
104
105 field = __find_event_field(&ftrace_generic_fields, name);
106 if (field)
107 return field;
108
109 return __find_event_field(&ftrace_common_fields, name);
110}
111
112static int __trace_define_field(struct list_head *head, const char *type,
113 const char *name, int offset, int size,
114 int is_signed, int filter_type)
115{
116 struct ftrace_event_field *field;
117
118 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
119 if (!field)
120 return -ENOMEM;
121
122 field->name = name;
123 field->type = type;
124
125 if (filter_type == FILTER_OTHER)
126 field->filter_type = filter_assign_type(type);
127 else
128 field->filter_type = filter_type;
129
130 field->offset = offset;
131 field->size = size;
132 field->is_signed = is_signed;
133
134 list_add(&field->link, head);
135
136 return 0;
137}
138
139int trace_define_field(struct trace_event_call *call, const char *type,
140 const char *name, int offset, int size, int is_signed,
141 int filter_type)
142{
143 struct list_head *head;
144
145 if (WARN_ON(!call->class))
146 return 0;
147
148 head = trace_get_fields(call);
149 return __trace_define_field(head, type, name, offset, size,
150 is_signed, filter_type);
151}
152EXPORT_SYMBOL_GPL(trace_define_field);
153
154#define __generic_field(type, item, filter_type) \
155 ret = __trace_define_field(&ftrace_generic_fields, #type, \
156 #item, 0, 0, is_signed_type(type), \
157 filter_type); \
158 if (ret) \
159 return ret;
160
161#define __common_field(type, item) \
162 ret = __trace_define_field(&ftrace_common_fields, #type, \
163 "common_" #item, \
164 offsetof(typeof(ent), item), \
165 sizeof(ent.item), \
166 is_signed_type(type), FILTER_OTHER); \
167 if (ret) \
168 return ret;
169
170static int trace_define_generic_fields(void)
171{
172 int ret;
173
174 __generic_field(int, CPU, FILTER_CPU);
175 __generic_field(int, cpu, FILTER_CPU);
176 __generic_field(char *, COMM, FILTER_COMM);
177 __generic_field(char *, comm, FILTER_COMM);
178
179 return ret;
180}
181
182static int trace_define_common_fields(void)
183{
184 int ret;
185 struct trace_entry ent;
186
187 __common_field(unsigned short, type);
188 __common_field(unsigned char, flags);
189 __common_field(unsigned char, preempt_count);
190 __common_field(int, pid);
191
192 return ret;
193}
194
195static void trace_destroy_fields(struct trace_event_call *call)
196{
197 struct ftrace_event_field *field, *next;
198 struct list_head *head;
199
200 head = trace_get_fields(call);
201 list_for_each_entry_safe(field, next, head, link) {
202 list_del(&field->link);
203 kmem_cache_free(field_cachep, field);
204 }
205}
206
207int trace_event_raw_init(struct trace_event_call *call)
208{
209 int id;
210
211 id = register_trace_event(&call->event);
212 if (!id)
213 return -ENODEV;
214
215 return 0;
216}
217EXPORT_SYMBOL_GPL(trace_event_raw_init);
218
219bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
220{
221 struct trace_array *tr = trace_file->tr;
222 struct trace_array_cpu *data;
223 struct trace_pid_list *pid_list;
224
225 pid_list = rcu_dereference_sched(tr->filtered_pids);
226 if (!pid_list)
227 return false;
228
229 data = this_cpu_ptr(tr->trace_buffer.data);
230
231 return data->ignore_pid;
232}
233EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
234
235void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
236 struct trace_event_file *trace_file,
237 unsigned long len)
238{
239 struct trace_event_call *event_call = trace_file->event_call;
240
241 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
242 trace_event_ignore_this_pid(trace_file))
243 return NULL;
244
245 local_save_flags(fbuffer->flags);
246 fbuffer->pc = preempt_count();
247 fbuffer->trace_file = trace_file;
248
249 fbuffer->event =
250 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
251 event_call->event.type, len,
252 fbuffer->flags, fbuffer->pc);
253 if (!fbuffer->event)
254 return NULL;
255
256 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
257 return fbuffer->entry;
258}
259EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
260
261static DEFINE_SPINLOCK(tracepoint_iter_lock);
262
263static void output_printk(struct trace_event_buffer *fbuffer)
264{
265 struct trace_event_call *event_call;
266 struct trace_event *event;
267 unsigned long flags;
268 struct trace_iterator *iter = tracepoint_print_iter;
269
270 if (!iter)
271 return;
272
273 event_call = fbuffer->trace_file->event_call;
274 if (!event_call || !event_call->event.funcs ||
275 !event_call->event.funcs->trace)
276 return;
277
278 event = &fbuffer->trace_file->event_call->event;
279
280 spin_lock_irqsave(&tracepoint_iter_lock, flags);
281 trace_seq_init(&iter->seq);
282 iter->ent = fbuffer->entry;
283 event_call->event.funcs->trace(iter, 0, event);
284 trace_seq_putc(&iter->seq, 0);
285 printk("%s", iter->seq.buffer);
286
287 spin_unlock_irqrestore(&tracepoint_iter_lock, flags);
288}
289
290void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)
291{
292 if (tracepoint_printk)
293 output_printk(fbuffer);
294
295 event_trigger_unlock_commit(fbuffer->trace_file, fbuffer->buffer,
296 fbuffer->event, fbuffer->entry,
297 fbuffer->flags, fbuffer->pc);
298}
299EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
300
301int trace_event_reg(struct trace_event_call *call,
302 enum trace_reg type, void *data)
303{
304 struct trace_event_file *file = data;
305
306 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
307 switch (type) {
308 case TRACE_REG_REGISTER:
309 return tracepoint_probe_register(call->tp,
310 call->class->probe,
311 file);
312 case TRACE_REG_UNREGISTER:
313 tracepoint_probe_unregister(call->tp,
314 call->class->probe,
315 file);
316 return 0;
317
318#ifdef CONFIG_PERF_EVENTS
319 case TRACE_REG_PERF_REGISTER:
320 return tracepoint_probe_register(call->tp,
321 call->class->perf_probe,
322 call);
323 case TRACE_REG_PERF_UNREGISTER:
324 tracepoint_probe_unregister(call->tp,
325 call->class->perf_probe,
326 call);
327 return 0;
328 case TRACE_REG_PERF_OPEN:
329 case TRACE_REG_PERF_CLOSE:
330 case TRACE_REG_PERF_ADD:
331 case TRACE_REG_PERF_DEL:
332 return 0;
333#endif
334 }
335 return 0;
336}
337EXPORT_SYMBOL_GPL(trace_event_reg);
338
339void trace_event_enable_cmd_record(bool enable)
340{
341 struct trace_event_file *file;
342 struct trace_array *tr;
343
344 mutex_lock(&event_mutex);
345 do_for_each_event_file(tr, file) {
346
347 if (!(file->flags & EVENT_FILE_FL_ENABLED))
348 continue;
349
350 if (enable) {
351 tracing_start_cmdline_record();
352 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
353 } else {
354 tracing_stop_cmdline_record();
355 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
356 }
357 } while_for_each_event_file();
358 mutex_unlock(&event_mutex);
359}
360
361static int __ftrace_event_enable_disable(struct trace_event_file *file,
362 int enable, int soft_disable)
363{
364 struct trace_event_call *call = file->event_call;
365 struct trace_array *tr = file->tr;
366 int ret = 0;
367 int disable;
368
369 switch (enable) {
370 case 0:
371 /*
372 * When soft_disable is set and enable is cleared, the sm_ref
373 * reference counter is decremented. If it reaches 0, we want
374 * to clear the SOFT_DISABLED flag but leave the event in the
375 * state that it was. That is, if the event was enabled and
376 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
377 * is set we do not want the event to be enabled before we
378 * clear the bit.
379 *
380 * When soft_disable is not set but the SOFT_MODE flag is,
381 * we do nothing. Do not disable the tracepoint, otherwise
382 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
383 */
384 if (soft_disable) {
385 if (atomic_dec_return(&file->sm_ref) > 0)
386 break;
387 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
388 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
389 } else
390 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
391
392 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
393 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
394 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
395 tracing_stop_cmdline_record();
396 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
397 }
398 call->class->reg(call, TRACE_REG_UNREGISTER, file);
399 }
400 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
401 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
402 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
403 else
404 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
405 break;
406 case 1:
407 /*
408 * When soft_disable is set and enable is set, we want to
409 * register the tracepoint for the event, but leave the event
410 * as is. That means, if the event was already enabled, we do
411 * nothing (but set SOFT_MODE). If the event is disabled, we
412 * set SOFT_DISABLED before enabling the event tracepoint, so
413 * it still seems to be disabled.
414 */
415 if (!soft_disable)
416 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
417 else {
418 if (atomic_inc_return(&file->sm_ref) > 1)
419 break;
420 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
421 }
422
423 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
424
425 /* Keep the event disabled, when going to SOFT_MODE. */
426 if (soft_disable)
427 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
428
429 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
430 tracing_start_cmdline_record();
431 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
432 }
433 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
434 if (ret) {
435 tracing_stop_cmdline_record();
436 pr_info("event trace: Could not enable event "
437 "%s\n", trace_event_name(call));
438 break;
439 }
440 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
441
442 /* WAS_ENABLED gets set but never cleared. */
443 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
444 }
445 break;
446 }
447
448 return ret;
449}
450
451int trace_event_enable_disable(struct trace_event_file *file,
452 int enable, int soft_disable)
453{
454 return __ftrace_event_enable_disable(file, enable, soft_disable);
455}
456
457static int ftrace_event_enable_disable(struct trace_event_file *file,
458 int enable)
459{
460 return __ftrace_event_enable_disable(file, enable, 0);
461}
462
463static void ftrace_clear_events(struct trace_array *tr)
464{
465 struct trace_event_file *file;
466
467 mutex_lock(&event_mutex);
468 list_for_each_entry(file, &tr->events, list) {
469 ftrace_event_enable_disable(file, 0);
470 }
471 mutex_unlock(&event_mutex);
472}
473
474static int cmp_pid(const void *key, const void *elt)
475{
476 const pid_t *search_pid = key;
477 const pid_t *pid = elt;
478
479 if (*search_pid == *pid)
480 return 0;
481 if (*search_pid < *pid)
482 return -1;
483 return 1;
484}
485
486static bool
487check_ignore_pid(struct trace_pid_list *filtered_pids, struct task_struct *task)
488{
489 pid_t search_pid;
490 pid_t *pid;
491
492 /*
493 * Return false, because if filtered_pids does not exist,
494 * all pids are good to trace.
495 */
496 if (!filtered_pids)
497 return false;
498
499 search_pid = task->pid;
500
501 pid = bsearch(&search_pid, filtered_pids->pids,
502 filtered_pids->nr_pids, sizeof(pid_t),
503 cmp_pid);
504 if (!pid)
505 return true;
506
507 return false;
508}
509
510static void
511event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
512 struct task_struct *prev, struct task_struct *next)
513{
514 struct trace_array *tr = data;
515 struct trace_pid_list *pid_list;
516
517 pid_list = rcu_dereference_sched(tr->filtered_pids);
518
519 this_cpu_write(tr->trace_buffer.data->ignore_pid,
520 check_ignore_pid(pid_list, prev) &&
521 check_ignore_pid(pid_list, next));
522}
523
524static void
525event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
526 struct task_struct *prev, struct task_struct *next)
527{
528 struct trace_array *tr = data;
529 struct trace_pid_list *pid_list;
530
531 pid_list = rcu_dereference_sched(tr->filtered_pids);
532
533 this_cpu_write(tr->trace_buffer.data->ignore_pid,
534 check_ignore_pid(pid_list, next));
535}
536
537static void
538event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
539{
540 struct trace_array *tr = data;
541 struct trace_pid_list *pid_list;
542
543 /* Nothing to do if we are already tracing */
544 if (!this_cpu_read(tr->trace_buffer.data->ignore_pid))
545 return;
546
547 pid_list = rcu_dereference_sched(tr->filtered_pids);
548
549 this_cpu_write(tr->trace_buffer.data->ignore_pid,
550 check_ignore_pid(pid_list, task));
551}
552
553static void
554event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
555{
556 struct trace_array *tr = data;
557 struct trace_pid_list *pid_list;
558
559 /* Nothing to do if we are not tracing */
560 if (this_cpu_read(tr->trace_buffer.data->ignore_pid))
561 return;
562
563 pid_list = rcu_dereference_sched(tr->filtered_pids);
564
565 /* Set tracing if current is enabled */
566 this_cpu_write(tr->trace_buffer.data->ignore_pid,
567 check_ignore_pid(pid_list, current));
568}
569
570static void __ftrace_clear_event_pids(struct trace_array *tr)
571{
572 struct trace_pid_list *pid_list;
573 struct trace_event_file *file;
574 int cpu;
575
576 pid_list = rcu_dereference_protected(tr->filtered_pids,
577 lockdep_is_held(&event_mutex));
578 if (!pid_list)
579 return;
580
581 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
582 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
583
584 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
585 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
586
587 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
588 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
589
590 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
591 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
592
593 list_for_each_entry(file, &tr->events, list) {
594 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
595 }
596
597 for_each_possible_cpu(cpu)
598 per_cpu_ptr(tr->trace_buffer.data, cpu)->ignore_pid = false;
599
600 rcu_assign_pointer(tr->filtered_pids, NULL);
601
602 /* Wait till all users are no longer using pid filtering */
603 synchronize_sched();
604
605 free_pages((unsigned long)pid_list->pids, pid_list->order);
606 kfree(pid_list);
607}
608
609static void ftrace_clear_event_pids(struct trace_array *tr)
610{
611 mutex_lock(&event_mutex);
612 __ftrace_clear_event_pids(tr);
613 mutex_unlock(&event_mutex);
614}
615
616static void __put_system(struct event_subsystem *system)
617{
618 struct event_filter *filter = system->filter;
619
620 WARN_ON_ONCE(system_refcount(system) == 0);
621 if (system_refcount_dec(system))
622 return;
623
624 list_del(&system->list);
625
626 if (filter) {
627 kfree(filter->filter_string);
628 kfree(filter);
629 }
630 kfree_const(system->name);
631 kfree(system);
632}
633
634static void __get_system(struct event_subsystem *system)
635{
636 WARN_ON_ONCE(system_refcount(system) == 0);
637 system_refcount_inc(system);
638}
639
640static void __get_system_dir(struct trace_subsystem_dir *dir)
641{
642 WARN_ON_ONCE(dir->ref_count == 0);
643 dir->ref_count++;
644 __get_system(dir->subsystem);
645}
646
647static void __put_system_dir(struct trace_subsystem_dir *dir)
648{
649 WARN_ON_ONCE(dir->ref_count == 0);
650 /* If the subsystem is about to be freed, the dir must be too */
651 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
652
653 __put_system(dir->subsystem);
654 if (!--dir->ref_count)
655 kfree(dir);
656}
657
658static void put_system(struct trace_subsystem_dir *dir)
659{
660 mutex_lock(&event_mutex);
661 __put_system_dir(dir);
662 mutex_unlock(&event_mutex);
663}
664
665static void remove_subsystem(struct trace_subsystem_dir *dir)
666{
667 if (!dir)
668 return;
669
670 if (!--dir->nr_events) {
671 tracefs_remove_recursive(dir->entry);
672 list_del(&dir->list);
673 __put_system_dir(dir);
674 }
675}
676
677static void remove_event_file_dir(struct trace_event_file *file)
678{
679 struct dentry *dir = file->dir;
680 struct dentry *child;
681
682 if (dir) {
683 spin_lock(&dir->d_lock); /* probably unneeded */
684 list_for_each_entry(child, &dir->d_subdirs, d_child) {
685 if (d_really_is_positive(child)) /* probably unneeded */
686 d_inode(child)->i_private = NULL;
687 }
688 spin_unlock(&dir->d_lock);
689
690 tracefs_remove_recursive(dir);
691 }
692
693 list_del(&file->list);
694 remove_subsystem(file->system);
695 free_event_filter(file->filter);
696 kmem_cache_free(file_cachep, file);
697}
698
699/*
700 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
701 */
702static int
703__ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
704 const char *sub, const char *event, int set)
705{
706 struct trace_event_file *file;
707 struct trace_event_call *call;
708 const char *name;
709 int ret = -EINVAL;
710
711 list_for_each_entry(file, &tr->events, list) {
712
713 call = file->event_call;
714 name = trace_event_name(call);
715
716 if (!name || !call->class || !call->class->reg)
717 continue;
718
719 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
720 continue;
721
722 if (match &&
723 strcmp(match, name) != 0 &&
724 strcmp(match, call->class->system) != 0)
725 continue;
726
727 if (sub && strcmp(sub, call->class->system) != 0)
728 continue;
729
730 if (event && strcmp(event, name) != 0)
731 continue;
732
733 ftrace_event_enable_disable(file, set);
734
735 ret = 0;
736 }
737
738 return ret;
739}
740
741static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
742 const char *sub, const char *event, int set)
743{
744 int ret;
745
746 mutex_lock(&event_mutex);
747 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
748 mutex_unlock(&event_mutex);
749
750 return ret;
751}
752
753static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
754{
755 char *event = NULL, *sub = NULL, *match;
756 int ret;
757
758 /*
759 * The buf format can be <subsystem>:<event-name>
760 * *:<event-name> means any event by that name.
761 * :<event-name> is the same.
762 *
763 * <subsystem>:* means all events in that subsystem
764 * <subsystem>: means the same.
765 *
766 * <name> (no ':') means all events in a subsystem with
767 * the name <name> or any event that matches <name>
768 */
769
770 match = strsep(&buf, ":");
771 if (buf) {
772 sub = match;
773 event = buf;
774 match = NULL;
775
776 if (!strlen(sub) || strcmp(sub, "*") == 0)
777 sub = NULL;
778 if (!strlen(event) || strcmp(event, "*") == 0)
779 event = NULL;
780 }
781
782 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
783
784 /* Put back the colon to allow this to be called again */
785 if (buf)
786 *(buf - 1) = ':';
787
788 return ret;
789}
790
791/**
792 * trace_set_clr_event - enable or disable an event
793 * @system: system name to match (NULL for any system)
794 * @event: event name to match (NULL for all events, within system)
795 * @set: 1 to enable, 0 to disable
796 *
797 * This is a way for other parts of the kernel to enable or disable
798 * event recording.
799 *
800 * Returns 0 on success, -EINVAL if the parameters do not match any
801 * registered events.
802 */
803int trace_set_clr_event(const char *system, const char *event, int set)
804{
805 struct trace_array *tr = top_trace_array();
806
807 if (!tr)
808 return -ENODEV;
809
810 return __ftrace_set_clr_event(tr, NULL, system, event, set);
811}
812EXPORT_SYMBOL_GPL(trace_set_clr_event);
813
814/* 128 should be much more than enough */
815#define EVENT_BUF_SIZE 127
816
817static ssize_t
818ftrace_event_write(struct file *file, const char __user *ubuf,
819 size_t cnt, loff_t *ppos)
820{
821 struct trace_parser parser;
822 struct seq_file *m = file->private_data;
823 struct trace_array *tr = m->private;
824 ssize_t read, ret;
825
826 if (!cnt)
827 return 0;
828
829 ret = tracing_update_buffers();
830 if (ret < 0)
831 return ret;
832
833 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
834 return -ENOMEM;
835
836 read = trace_get_user(&parser, ubuf, cnt, ppos);
837
838 if (read >= 0 && trace_parser_loaded((&parser))) {
839 int set = 1;
840
841 if (*parser.buffer == '!')
842 set = 0;
843
844 parser.buffer[parser.idx] = 0;
845
846 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
847 if (ret)
848 goto out_put;
849 }
850
851 ret = read;
852
853 out_put:
854 trace_parser_put(&parser);
855
856 return ret;
857}
858
859static void *
860t_next(struct seq_file *m, void *v, loff_t *pos)
861{
862 struct trace_event_file *file = v;
863 struct trace_event_call *call;
864 struct trace_array *tr = m->private;
865
866 (*pos)++;
867
868 list_for_each_entry_continue(file, &tr->events, list) {
869 call = file->event_call;
870 /*
871 * The ftrace subsystem is for showing formats only.
872 * They can not be enabled or disabled via the event files.
873 */
874 if (call->class && call->class->reg &&
875 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
876 return file;
877 }
878
879 return NULL;
880}
881
882static void *t_start(struct seq_file *m, loff_t *pos)
883{
884 struct trace_event_file *file;
885 struct trace_array *tr = m->private;
886 loff_t l;
887
888 mutex_lock(&event_mutex);
889
890 file = list_entry(&tr->events, struct trace_event_file, list);
891 for (l = 0; l <= *pos; ) {
892 file = t_next(m, file, &l);
893 if (!file)
894 break;
895 }
896 return file;
897}
898
899static void *
900s_next(struct seq_file *m, void *v, loff_t *pos)
901{
902 struct trace_event_file *file = v;
903 struct trace_array *tr = m->private;
904
905 (*pos)++;
906
907 list_for_each_entry_continue(file, &tr->events, list) {
908 if (file->flags & EVENT_FILE_FL_ENABLED)
909 return file;
910 }
911
912 return NULL;
913}
914
915static void *s_start(struct seq_file *m, loff_t *pos)
916{
917 struct trace_event_file *file;
918 struct trace_array *tr = m->private;
919 loff_t l;
920
921 mutex_lock(&event_mutex);
922
923 file = list_entry(&tr->events, struct trace_event_file, list);
924 for (l = 0; l <= *pos; ) {
925 file = s_next(m, file, &l);
926 if (!file)
927 break;
928 }
929 return file;
930}
931
932static int t_show(struct seq_file *m, void *v)
933{
934 struct trace_event_file *file = v;
935 struct trace_event_call *call = file->event_call;
936
937 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
938 seq_printf(m, "%s:", call->class->system);
939 seq_printf(m, "%s\n", trace_event_name(call));
940
941 return 0;
942}
943
944static void t_stop(struct seq_file *m, void *p)
945{
946 mutex_unlock(&event_mutex);
947}
948
949static void *p_start(struct seq_file *m, loff_t *pos)
950 __acquires(RCU)
951{
952 struct trace_pid_list *pid_list;
953 struct trace_array *tr = m->private;
954
955 /*
956 * Grab the mutex, to keep calls to p_next() having the same
957 * tr->filtered_pids as p_start() has.
958 * If we just passed the tr->filtered_pids around, then RCU would
959 * have been enough, but doing that makes things more complex.
960 */
961 mutex_lock(&event_mutex);
962 rcu_read_lock_sched();
963
964 pid_list = rcu_dereference_sched(tr->filtered_pids);
965
966 if (!pid_list || *pos >= pid_list->nr_pids)
967 return NULL;
968
969 return (void *)&pid_list->pids[*pos];
970}
971
972static void p_stop(struct seq_file *m, void *p)
973 __releases(RCU)
974{
975 rcu_read_unlock_sched();
976 mutex_unlock(&event_mutex);
977}
978
979static void *
980p_next(struct seq_file *m, void *v, loff_t *pos)
981{
982 struct trace_array *tr = m->private;
983 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
984
985 (*pos)++;
986
987 if (*pos >= pid_list->nr_pids)
988 return NULL;
989
990 return (void *)&pid_list->pids[*pos];
991}
992
993static int p_show(struct seq_file *m, void *v)
994{
995 pid_t *pid = v;
996
997 seq_printf(m, "%d\n", *pid);
998 return 0;
999}
1000
1001static ssize_t
1002event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1003 loff_t *ppos)
1004{
1005 struct trace_event_file *file;
1006 unsigned long flags;
1007 char buf[4] = "0";
1008
1009 mutex_lock(&event_mutex);
1010 file = event_file_data(filp);
1011 if (likely(file))
1012 flags = file->flags;
1013 mutex_unlock(&event_mutex);
1014
1015 if (!file)
1016 return -ENODEV;
1017
1018 if (flags & EVENT_FILE_FL_ENABLED &&
1019 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1020 strcpy(buf, "1");
1021
1022 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1023 flags & EVENT_FILE_FL_SOFT_MODE)
1024 strcat(buf, "*");
1025
1026 strcat(buf, "\n");
1027
1028 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1029}
1030
1031static ssize_t
1032event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1033 loff_t *ppos)
1034{
1035 struct trace_event_file *file;
1036 unsigned long val;
1037 int ret;
1038
1039 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1040 if (ret)
1041 return ret;
1042
1043 ret = tracing_update_buffers();
1044 if (ret < 0)
1045 return ret;
1046
1047 switch (val) {
1048 case 0:
1049 case 1:
1050 ret = -ENODEV;
1051 mutex_lock(&event_mutex);
1052 file = event_file_data(filp);
1053 if (likely(file))
1054 ret = ftrace_event_enable_disable(file, val);
1055 mutex_unlock(&event_mutex);
1056 break;
1057
1058 default:
1059 return -EINVAL;
1060 }
1061
1062 *ppos += cnt;
1063
1064 return ret ? ret : cnt;
1065}
1066
1067static ssize_t
1068system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1069 loff_t *ppos)
1070{
1071 const char set_to_char[4] = { '?', '0', '1', 'X' };
1072 struct trace_subsystem_dir *dir = filp->private_data;
1073 struct event_subsystem *system = dir->subsystem;
1074 struct trace_event_call *call;
1075 struct trace_event_file *file;
1076 struct trace_array *tr = dir->tr;
1077 char buf[2];
1078 int set = 0;
1079 int ret;
1080
1081 mutex_lock(&event_mutex);
1082 list_for_each_entry(file, &tr->events, list) {
1083 call = file->event_call;
1084 if (!trace_event_name(call) || !call->class || !call->class->reg)
1085 continue;
1086
1087 if (system && strcmp(call->class->system, system->name) != 0)
1088 continue;
1089
1090 /*
1091 * We need to find out if all the events are set
1092 * or if all events or cleared, or if we have
1093 * a mixture.
1094 */
1095 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1096
1097 /*
1098 * If we have a mixture, no need to look further.
1099 */
1100 if (set == 3)
1101 break;
1102 }
1103 mutex_unlock(&event_mutex);
1104
1105 buf[0] = set_to_char[set];
1106 buf[1] = '\n';
1107
1108 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1109
1110 return ret;
1111}
1112
1113static ssize_t
1114system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1115 loff_t *ppos)
1116{
1117 struct trace_subsystem_dir *dir = filp->private_data;
1118 struct event_subsystem *system = dir->subsystem;
1119 const char *name = NULL;
1120 unsigned long val;
1121 ssize_t ret;
1122
1123 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1124 if (ret)
1125 return ret;
1126
1127 ret = tracing_update_buffers();
1128 if (ret < 0)
1129 return ret;
1130
1131 if (val != 0 && val != 1)
1132 return -EINVAL;
1133
1134 /*
1135 * Opening of "enable" adds a ref count to system,
1136 * so the name is safe to use.
1137 */
1138 if (system)
1139 name = system->name;
1140
1141 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1142 if (ret)
1143 goto out;
1144
1145 ret = cnt;
1146
1147out:
1148 *ppos += cnt;
1149
1150 return ret;
1151}
1152
1153enum {
1154 FORMAT_HEADER = 1,
1155 FORMAT_FIELD_SEPERATOR = 2,
1156 FORMAT_PRINTFMT = 3,
1157};
1158
1159static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1160{
1161 struct trace_event_call *call = event_file_data(m->private);
1162 struct list_head *common_head = &ftrace_common_fields;
1163 struct list_head *head = trace_get_fields(call);
1164 struct list_head *node = v;
1165
1166 (*pos)++;
1167
1168 switch ((unsigned long)v) {
1169 case FORMAT_HEADER:
1170 node = common_head;
1171 break;
1172
1173 case FORMAT_FIELD_SEPERATOR:
1174 node = head;
1175 break;
1176
1177 case FORMAT_PRINTFMT:
1178 /* all done */
1179 return NULL;
1180 }
1181
1182 node = node->prev;
1183 if (node == common_head)
1184 return (void *)FORMAT_FIELD_SEPERATOR;
1185 else if (node == head)
1186 return (void *)FORMAT_PRINTFMT;
1187 else
1188 return node;
1189}
1190
1191static int f_show(struct seq_file *m, void *v)
1192{
1193 struct trace_event_call *call = event_file_data(m->private);
1194 struct ftrace_event_field *field;
1195 const char *array_descriptor;
1196
1197 switch ((unsigned long)v) {
1198 case FORMAT_HEADER:
1199 seq_printf(m, "name: %s\n", trace_event_name(call));
1200 seq_printf(m, "ID: %d\n", call->event.type);
1201 seq_puts(m, "format:\n");
1202 return 0;
1203
1204 case FORMAT_FIELD_SEPERATOR:
1205 seq_putc(m, '\n');
1206 return 0;
1207
1208 case FORMAT_PRINTFMT:
1209 seq_printf(m, "\nprint fmt: %s\n",
1210 call->print_fmt);
1211 return 0;
1212 }
1213
1214 field = list_entry(v, struct ftrace_event_field, link);
1215 /*
1216 * Smartly shows the array type(except dynamic array).
1217 * Normal:
1218 * field:TYPE VAR
1219 * If TYPE := TYPE[LEN], it is shown:
1220 * field:TYPE VAR[LEN]
1221 */
1222 array_descriptor = strchr(field->type, '[');
1223
1224 if (!strncmp(field->type, "__data_loc", 10))
1225 array_descriptor = NULL;
1226
1227 if (!array_descriptor)
1228 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1229 field->type, field->name, field->offset,
1230 field->size, !!field->is_signed);
1231 else
1232 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1233 (int)(array_descriptor - field->type),
1234 field->type, field->name,
1235 array_descriptor, field->offset,
1236 field->size, !!field->is_signed);
1237
1238 return 0;
1239}
1240
1241static void *f_start(struct seq_file *m, loff_t *pos)
1242{
1243 void *p = (void *)FORMAT_HEADER;
1244 loff_t l = 0;
1245
1246 /* ->stop() is called even if ->start() fails */
1247 mutex_lock(&event_mutex);
1248 if (!event_file_data(m->private))
1249 return ERR_PTR(-ENODEV);
1250
1251 while (l < *pos && p)
1252 p = f_next(m, p, &l);
1253
1254 return p;
1255}
1256
1257static void f_stop(struct seq_file *m, void *p)
1258{
1259 mutex_unlock(&event_mutex);
1260}
1261
1262static const struct seq_operations trace_format_seq_ops = {
1263 .start = f_start,
1264 .next = f_next,
1265 .stop = f_stop,
1266 .show = f_show,
1267};
1268
1269static int trace_format_open(struct inode *inode, struct file *file)
1270{
1271 struct seq_file *m;
1272 int ret;
1273
1274 ret = seq_open(file, &trace_format_seq_ops);
1275 if (ret < 0)
1276 return ret;
1277
1278 m = file->private_data;
1279 m->private = file;
1280
1281 return 0;
1282}
1283
1284static ssize_t
1285event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1286{
1287 int id = (long)event_file_data(filp);
1288 char buf[32];
1289 int len;
1290
1291 if (*ppos)
1292 return 0;
1293
1294 if (unlikely(!id))
1295 return -ENODEV;
1296
1297 len = sprintf(buf, "%d\n", id);
1298
1299 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1300}
1301
1302static ssize_t
1303event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1304 loff_t *ppos)
1305{
1306 struct trace_event_file *file;
1307 struct trace_seq *s;
1308 int r = -ENODEV;
1309
1310 if (*ppos)
1311 return 0;
1312
1313 s = kmalloc(sizeof(*s), GFP_KERNEL);
1314
1315 if (!s)
1316 return -ENOMEM;
1317
1318 trace_seq_init(s);
1319
1320 mutex_lock(&event_mutex);
1321 file = event_file_data(filp);
1322 if (file)
1323 print_event_filter(file, s);
1324 mutex_unlock(&event_mutex);
1325
1326 if (file)
1327 r = simple_read_from_buffer(ubuf, cnt, ppos,
1328 s->buffer, trace_seq_used(s));
1329
1330 kfree(s);
1331
1332 return r;
1333}
1334
1335static ssize_t
1336event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1337 loff_t *ppos)
1338{
1339 struct trace_event_file *file;
1340 char *buf;
1341 int err = -ENODEV;
1342
1343 if (cnt >= PAGE_SIZE)
1344 return -EINVAL;
1345
1346 buf = memdup_user_nul(ubuf, cnt);
1347 if (IS_ERR(buf))
1348 return PTR_ERR(buf);
1349
1350 mutex_lock(&event_mutex);
1351 file = event_file_data(filp);
1352 if (file)
1353 err = apply_event_filter(file, buf);
1354 mutex_unlock(&event_mutex);
1355
1356 kfree(buf);
1357 if (err < 0)
1358 return err;
1359
1360 *ppos += cnt;
1361
1362 return cnt;
1363}
1364
1365static LIST_HEAD(event_subsystems);
1366
1367static int subsystem_open(struct inode *inode, struct file *filp)
1368{
1369 struct event_subsystem *system = NULL;
1370 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1371 struct trace_array *tr;
1372 int ret;
1373
1374 if (tracing_is_disabled())
1375 return -ENODEV;
1376
1377 /* Make sure the system still exists */
1378 mutex_lock(&trace_types_lock);
1379 mutex_lock(&event_mutex);
1380 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1381 list_for_each_entry(dir, &tr->systems, list) {
1382 if (dir == inode->i_private) {
1383 /* Don't open systems with no events */
1384 if (dir->nr_events) {
1385 __get_system_dir(dir);
1386 system = dir->subsystem;
1387 }
1388 goto exit_loop;
1389 }
1390 }
1391 }
1392 exit_loop:
1393 mutex_unlock(&event_mutex);
1394 mutex_unlock(&trace_types_lock);
1395
1396 if (!system)
1397 return -ENODEV;
1398
1399 /* Some versions of gcc think dir can be uninitialized here */
1400 WARN_ON(!dir);
1401
1402 /* Still need to increment the ref count of the system */
1403 if (trace_array_get(tr) < 0) {
1404 put_system(dir);
1405 return -ENODEV;
1406 }
1407
1408 ret = tracing_open_generic(inode, filp);
1409 if (ret < 0) {
1410 trace_array_put(tr);
1411 put_system(dir);
1412 }
1413
1414 return ret;
1415}
1416
1417static int system_tr_open(struct inode *inode, struct file *filp)
1418{
1419 struct trace_subsystem_dir *dir;
1420 struct trace_array *tr = inode->i_private;
1421 int ret;
1422
1423 if (tracing_is_disabled())
1424 return -ENODEV;
1425
1426 if (trace_array_get(tr) < 0)
1427 return -ENODEV;
1428
1429 /* Make a temporary dir that has no system but points to tr */
1430 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1431 if (!dir) {
1432 trace_array_put(tr);
1433 return -ENOMEM;
1434 }
1435
1436 dir->tr = tr;
1437
1438 ret = tracing_open_generic(inode, filp);
1439 if (ret < 0) {
1440 trace_array_put(tr);
1441 kfree(dir);
1442 return ret;
1443 }
1444
1445 filp->private_data = dir;
1446
1447 return 0;
1448}
1449
1450static int subsystem_release(struct inode *inode, struct file *file)
1451{
1452 struct trace_subsystem_dir *dir = file->private_data;
1453
1454 trace_array_put(dir->tr);
1455
1456 /*
1457 * If dir->subsystem is NULL, then this is a temporary
1458 * descriptor that was made for a trace_array to enable
1459 * all subsystems.
1460 */
1461 if (dir->subsystem)
1462 put_system(dir);
1463 else
1464 kfree(dir);
1465
1466 return 0;
1467}
1468
1469static ssize_t
1470subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1471 loff_t *ppos)
1472{
1473 struct trace_subsystem_dir *dir = filp->private_data;
1474 struct event_subsystem *system = dir->subsystem;
1475 struct trace_seq *s;
1476 int r;
1477
1478 if (*ppos)
1479 return 0;
1480
1481 s = kmalloc(sizeof(*s), GFP_KERNEL);
1482 if (!s)
1483 return -ENOMEM;
1484
1485 trace_seq_init(s);
1486
1487 print_subsystem_event_filter(system, s);
1488 r = simple_read_from_buffer(ubuf, cnt, ppos,
1489 s->buffer, trace_seq_used(s));
1490
1491 kfree(s);
1492
1493 return r;
1494}
1495
1496static ssize_t
1497subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1498 loff_t *ppos)
1499{
1500 struct trace_subsystem_dir *dir = filp->private_data;
1501 char *buf;
1502 int err;
1503
1504 if (cnt >= PAGE_SIZE)
1505 return -EINVAL;
1506
1507 buf = memdup_user_nul(ubuf, cnt);
1508 if (IS_ERR(buf))
1509 return PTR_ERR(buf);
1510
1511 err = apply_subsystem_event_filter(dir, buf);
1512 kfree(buf);
1513 if (err < 0)
1514 return err;
1515
1516 *ppos += cnt;
1517
1518 return cnt;
1519}
1520
1521static ssize_t
1522show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1523{
1524 int (*func)(struct trace_seq *s) = filp->private_data;
1525 struct trace_seq *s;
1526 int r;
1527
1528 if (*ppos)
1529 return 0;
1530
1531 s = kmalloc(sizeof(*s), GFP_KERNEL);
1532 if (!s)
1533 return -ENOMEM;
1534
1535 trace_seq_init(s);
1536
1537 func(s);
1538 r = simple_read_from_buffer(ubuf, cnt, ppos,
1539 s->buffer, trace_seq_used(s));
1540
1541 kfree(s);
1542
1543 return r;
1544}
1545
1546static int max_pids(struct trace_pid_list *pid_list)
1547{
1548 return (PAGE_SIZE << pid_list->order) / sizeof(pid_t);
1549}
1550
1551static void ignore_task_cpu(void *data)
1552{
1553 struct trace_array *tr = data;
1554 struct trace_pid_list *pid_list;
1555
1556 /*
1557 * This function is called by on_each_cpu() while the
1558 * event_mutex is held.
1559 */
1560 pid_list = rcu_dereference_protected(tr->filtered_pids,
1561 mutex_is_locked(&event_mutex));
1562
1563 this_cpu_write(tr->trace_buffer.data->ignore_pid,
1564 check_ignore_pid(pid_list, current));
1565}
1566
1567static ssize_t
1568ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1569 size_t cnt, loff_t *ppos)
1570{
1571 struct seq_file *m = filp->private_data;
1572 struct trace_array *tr = m->private;
1573 struct trace_pid_list *filtered_pids = NULL;
1574 struct trace_pid_list *pid_list = NULL;
1575 struct trace_event_file *file;
1576 struct trace_parser parser;
1577 unsigned long val;
1578 loff_t this_pos;
1579 ssize_t read = 0;
1580 ssize_t ret = 0;
1581 pid_t pid;
1582 int i;
1583
1584 if (!cnt)
1585 return 0;
1586
1587 ret = tracing_update_buffers();
1588 if (ret < 0)
1589 return ret;
1590
1591 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
1592 return -ENOMEM;
1593
1594 mutex_lock(&event_mutex);
1595 /*
1596 * Load as many pids into the array before doing a
1597 * swap from the tr->filtered_pids to the new list.
1598 */
1599 while (cnt > 0) {
1600
1601 this_pos = 0;
1602
1603 ret = trace_get_user(&parser, ubuf, cnt, &this_pos);
1604 if (ret < 0 || !trace_parser_loaded(&parser))
1605 break;
1606
1607 read += ret;
1608 ubuf += ret;
1609 cnt -= ret;
1610
1611 parser.buffer[parser.idx] = 0;
1612
1613 ret = -EINVAL;
1614 if (kstrtoul(parser.buffer, 0, &val))
1615 break;
1616 if (val > INT_MAX)
1617 break;
1618
1619 pid = (pid_t)val;
1620
1621 ret = -ENOMEM;
1622 if (!pid_list) {
1623 pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL);
1624 if (!pid_list)
1625 break;
1626
1627 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1628 lockdep_is_held(&event_mutex));
1629 if (filtered_pids)
1630 pid_list->order = filtered_pids->order;
1631 else
1632 pid_list->order = 0;
1633
1634 pid_list->pids = (void *)__get_free_pages(GFP_KERNEL,
1635 pid_list->order);
1636 if (!pid_list->pids)
1637 break;
1638
1639 if (filtered_pids) {
1640 pid_list->nr_pids = filtered_pids->nr_pids;
1641 memcpy(pid_list->pids, filtered_pids->pids,
1642 pid_list->nr_pids * sizeof(pid_t));
1643 } else
1644 pid_list->nr_pids = 0;
1645 }
1646
1647 if (pid_list->nr_pids >= max_pids(pid_list)) {
1648 pid_t *pid_page;
1649
1650 pid_page = (void *)__get_free_pages(GFP_KERNEL,
1651 pid_list->order + 1);
1652 if (!pid_page)
1653 break;
1654 memcpy(pid_page, pid_list->pids,
1655 pid_list->nr_pids * sizeof(pid_t));
1656 free_pages((unsigned long)pid_list->pids, pid_list->order);
1657
1658 pid_list->order++;
1659 pid_list->pids = pid_page;
1660 }
1661
1662 pid_list->pids[pid_list->nr_pids++] = pid;
1663 trace_parser_clear(&parser);
1664 ret = 0;
1665 }
1666 trace_parser_put(&parser);
1667
1668 if (ret < 0) {
1669 if (pid_list)
1670 free_pages((unsigned long)pid_list->pids, pid_list->order);
1671 kfree(pid_list);
1672 mutex_unlock(&event_mutex);
1673 return ret;
1674 }
1675
1676 if (!pid_list) {
1677 mutex_unlock(&event_mutex);
1678 return ret;
1679 }
1680
1681 sort(pid_list->pids, pid_list->nr_pids, sizeof(pid_t), cmp_pid, NULL);
1682
1683 /* Remove duplicates */
1684 for (i = 1; i < pid_list->nr_pids; i++) {
1685 int start = i;
1686
1687 while (i < pid_list->nr_pids &&
1688 pid_list->pids[i - 1] == pid_list->pids[i])
1689 i++;
1690
1691 if (start != i) {
1692 if (i < pid_list->nr_pids) {
1693 memmove(&pid_list->pids[start], &pid_list->pids[i],
1694 (pid_list->nr_pids - i) * sizeof(pid_t));
1695 pid_list->nr_pids -= i - start;
1696 i = start;
1697 } else
1698 pid_list->nr_pids = start;
1699 }
1700 }
1701
1702 rcu_assign_pointer(tr->filtered_pids, pid_list);
1703
1704 list_for_each_entry(file, &tr->events, list) {
1705 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1706 }
1707
1708 if (filtered_pids) {
1709 synchronize_sched();
1710
1711 free_pages((unsigned long)filtered_pids->pids, filtered_pids->order);
1712 kfree(filtered_pids);
1713 } else {
1714 /*
1715 * Register a probe that is called before all other probes
1716 * to set ignore_pid if next or prev do not match.
1717 * Register a probe this is called after all other probes
1718 * to only keep ignore_pid set if next pid matches.
1719 */
1720 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1721 tr, INT_MAX);
1722 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1723 tr, 0);
1724
1725 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1726 tr, INT_MAX);
1727 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1728 tr, 0);
1729
1730 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1731 tr, INT_MAX);
1732 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1733 tr, 0);
1734
1735 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1736 tr, INT_MAX);
1737 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1738 tr, 0);
1739 }
1740
1741 /*
1742 * Ignoring of pids is done at task switch. But we have to
1743 * check for those tasks that are currently running.
1744 * Always do this in case a pid was appended or removed.
1745 */
1746 on_each_cpu(ignore_task_cpu, tr, 1);
1747
1748 mutex_unlock(&event_mutex);
1749
1750 ret = read;
1751 *ppos += read;
1752
1753 return ret;
1754}
1755
1756static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1757static int ftrace_event_set_open(struct inode *inode, struct file *file);
1758static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
1759static int ftrace_event_release(struct inode *inode, struct file *file);
1760
1761static const struct seq_operations show_event_seq_ops = {
1762 .start = t_start,
1763 .next = t_next,
1764 .show = t_show,
1765 .stop = t_stop,
1766};
1767
1768static const struct seq_operations show_set_event_seq_ops = {
1769 .start = s_start,
1770 .next = s_next,
1771 .show = t_show,
1772 .stop = t_stop,
1773};
1774
1775static const struct seq_operations show_set_pid_seq_ops = {
1776 .start = p_start,
1777 .next = p_next,
1778 .show = p_show,
1779 .stop = p_stop,
1780};
1781
1782static const struct file_operations ftrace_avail_fops = {
1783 .open = ftrace_event_avail_open,
1784 .read = seq_read,
1785 .llseek = seq_lseek,
1786 .release = seq_release,
1787};
1788
1789static const struct file_operations ftrace_set_event_fops = {
1790 .open = ftrace_event_set_open,
1791 .read = seq_read,
1792 .write = ftrace_event_write,
1793 .llseek = seq_lseek,
1794 .release = ftrace_event_release,
1795};
1796
1797static const struct file_operations ftrace_set_event_pid_fops = {
1798 .open = ftrace_event_set_pid_open,
1799 .read = seq_read,
1800 .write = ftrace_event_pid_write,
1801 .llseek = seq_lseek,
1802 .release = ftrace_event_release,
1803};
1804
1805static const struct file_operations ftrace_enable_fops = {
1806 .open = tracing_open_generic,
1807 .read = event_enable_read,
1808 .write = event_enable_write,
1809 .llseek = default_llseek,
1810};
1811
1812static const struct file_operations ftrace_event_format_fops = {
1813 .open = trace_format_open,
1814 .read = seq_read,
1815 .llseek = seq_lseek,
1816 .release = seq_release,
1817};
1818
1819static const struct file_operations ftrace_event_id_fops = {
1820 .read = event_id_read,
1821 .llseek = default_llseek,
1822};
1823
1824static const struct file_operations ftrace_event_filter_fops = {
1825 .open = tracing_open_generic,
1826 .read = event_filter_read,
1827 .write = event_filter_write,
1828 .llseek = default_llseek,
1829};
1830
1831static const struct file_operations ftrace_subsystem_filter_fops = {
1832 .open = subsystem_open,
1833 .read = subsystem_filter_read,
1834 .write = subsystem_filter_write,
1835 .llseek = default_llseek,
1836 .release = subsystem_release,
1837};
1838
1839static const struct file_operations ftrace_system_enable_fops = {
1840 .open = subsystem_open,
1841 .read = system_enable_read,
1842 .write = system_enable_write,
1843 .llseek = default_llseek,
1844 .release = subsystem_release,
1845};
1846
1847static const struct file_operations ftrace_tr_enable_fops = {
1848 .open = system_tr_open,
1849 .read = system_enable_read,
1850 .write = system_enable_write,
1851 .llseek = default_llseek,
1852 .release = subsystem_release,
1853};
1854
1855static const struct file_operations ftrace_show_header_fops = {
1856 .open = tracing_open_generic,
1857 .read = show_header,
1858 .llseek = default_llseek,
1859};
1860
1861static int
1862ftrace_event_open(struct inode *inode, struct file *file,
1863 const struct seq_operations *seq_ops)
1864{
1865 struct seq_file *m;
1866 int ret;
1867
1868 ret = seq_open(file, seq_ops);
1869 if (ret < 0)
1870 return ret;
1871 m = file->private_data;
1872 /* copy tr over to seq ops */
1873 m->private = inode->i_private;
1874
1875 return ret;
1876}
1877
1878static int ftrace_event_release(struct inode *inode, struct file *file)
1879{
1880 struct trace_array *tr = inode->i_private;
1881
1882 trace_array_put(tr);
1883
1884 return seq_release(inode, file);
1885}
1886
1887static int
1888ftrace_event_avail_open(struct inode *inode, struct file *file)
1889{
1890 const struct seq_operations *seq_ops = &show_event_seq_ops;
1891
1892 return ftrace_event_open(inode, file, seq_ops);
1893}
1894
1895static int
1896ftrace_event_set_open(struct inode *inode, struct file *file)
1897{
1898 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1899 struct trace_array *tr = inode->i_private;
1900 int ret;
1901
1902 if (trace_array_get(tr) < 0)
1903 return -ENODEV;
1904
1905 if ((file->f_mode & FMODE_WRITE) &&
1906 (file->f_flags & O_TRUNC))
1907 ftrace_clear_events(tr);
1908
1909 ret = ftrace_event_open(inode, file, seq_ops);
1910 if (ret < 0)
1911 trace_array_put(tr);
1912 return ret;
1913}
1914
1915static int
1916ftrace_event_set_pid_open(struct inode *inode, struct file *file)
1917{
1918 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
1919 struct trace_array *tr = inode->i_private;
1920 int ret;
1921
1922 if (trace_array_get(tr) < 0)
1923 return -ENODEV;
1924
1925 if ((file->f_mode & FMODE_WRITE) &&
1926 (file->f_flags & O_TRUNC))
1927 ftrace_clear_event_pids(tr);
1928
1929 ret = ftrace_event_open(inode, file, seq_ops);
1930 if (ret < 0)
1931 trace_array_put(tr);
1932 return ret;
1933}
1934
1935static struct event_subsystem *
1936create_new_subsystem(const char *name)
1937{
1938 struct event_subsystem *system;
1939
1940 /* need to create new entry */
1941 system = kmalloc(sizeof(*system), GFP_KERNEL);
1942 if (!system)
1943 return NULL;
1944
1945 system->ref_count = 1;
1946
1947 /* Only allocate if dynamic (kprobes and modules) */
1948 system->name = kstrdup_const(name, GFP_KERNEL);
1949 if (!system->name)
1950 goto out_free;
1951
1952 system->filter = NULL;
1953
1954 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1955 if (!system->filter)
1956 goto out_free;
1957
1958 list_add(&system->list, &event_subsystems);
1959
1960 return system;
1961
1962 out_free:
1963 kfree_const(system->name);
1964 kfree(system);
1965 return NULL;
1966}
1967
1968static struct dentry *
1969event_subsystem_dir(struct trace_array *tr, const char *name,
1970 struct trace_event_file *file, struct dentry *parent)
1971{
1972 struct trace_subsystem_dir *dir;
1973 struct event_subsystem *system;
1974 struct dentry *entry;
1975
1976 /* First see if we did not already create this dir */
1977 list_for_each_entry(dir, &tr->systems, list) {
1978 system = dir->subsystem;
1979 if (strcmp(system->name, name) == 0) {
1980 dir->nr_events++;
1981 file->system = dir;
1982 return dir->entry;
1983 }
1984 }
1985
1986 /* Now see if the system itself exists. */
1987 list_for_each_entry(system, &event_subsystems, list) {
1988 if (strcmp(system->name, name) == 0)
1989 break;
1990 }
1991 /* Reset system variable when not found */
1992 if (&system->list == &event_subsystems)
1993 system = NULL;
1994
1995 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1996 if (!dir)
1997 goto out_fail;
1998
1999 if (!system) {
2000 system = create_new_subsystem(name);
2001 if (!system)
2002 goto out_free;
2003 } else
2004 __get_system(system);
2005
2006 dir->entry = tracefs_create_dir(name, parent);
2007 if (!dir->entry) {
2008 pr_warn("Failed to create system directory %s\n", name);
2009 __put_system(system);
2010 goto out_free;
2011 }
2012
2013 dir->tr = tr;
2014 dir->ref_count = 1;
2015 dir->nr_events = 1;
2016 dir->subsystem = system;
2017 file->system = dir;
2018
2019 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
2020 &ftrace_subsystem_filter_fops);
2021 if (!entry) {
2022 kfree(system->filter);
2023 system->filter = NULL;
2024 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
2025 }
2026
2027 trace_create_file("enable", 0644, dir->entry, dir,
2028 &ftrace_system_enable_fops);
2029
2030 list_add(&dir->list, &tr->systems);
2031
2032 return dir->entry;
2033
2034 out_free:
2035 kfree(dir);
2036 out_fail:
2037 /* Only print this message if failed on memory allocation */
2038 if (!dir || !system)
2039 pr_warn("No memory to create event subsystem %s\n", name);
2040 return NULL;
2041}
2042
2043static int
2044event_create_dir(struct dentry *parent, struct trace_event_file *file)
2045{
2046 struct trace_event_call *call = file->event_call;
2047 struct trace_array *tr = file->tr;
2048 struct list_head *head;
2049 struct dentry *d_events;
2050 const char *name;
2051 int ret;
2052
2053 /*
2054 * If the trace point header did not define TRACE_SYSTEM
2055 * then the system would be called "TRACE_SYSTEM".
2056 */
2057 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
2058 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
2059 if (!d_events)
2060 return -ENOMEM;
2061 } else
2062 d_events = parent;
2063
2064 name = trace_event_name(call);
2065 file->dir = tracefs_create_dir(name, d_events);
2066 if (!file->dir) {
2067 pr_warn("Could not create tracefs '%s' directory\n", name);
2068 return -1;
2069 }
2070
2071 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2072 trace_create_file("enable", 0644, file->dir, file,
2073 &ftrace_enable_fops);
2074
2075#ifdef CONFIG_PERF_EVENTS
2076 if (call->event.type && call->class->reg)
2077 trace_create_file("id", 0444, file->dir,
2078 (void *)(long)call->event.type,
2079 &ftrace_event_id_fops);
2080#endif
2081
2082 /*
2083 * Other events may have the same class. Only update
2084 * the fields if they are not already defined.
2085 */
2086 head = trace_get_fields(call);
2087 if (list_empty(head)) {
2088 ret = call->class->define_fields(call);
2089 if (ret < 0) {
2090 pr_warn("Could not initialize trace point events/%s\n",
2091 name);
2092 return -1;
2093 }
2094 }
2095 trace_create_file("filter", 0644, file->dir, file,
2096 &ftrace_event_filter_fops);
2097
2098 /*
2099 * Only event directories that can be enabled should have
2100 * triggers.
2101 */
2102 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2103 trace_create_file("trigger", 0644, file->dir, file,
2104 &event_trigger_fops);
2105
2106 trace_create_file("format", 0444, file->dir, call,
2107 &ftrace_event_format_fops);
2108
2109 return 0;
2110}
2111
2112static void remove_event_from_tracers(struct trace_event_call *call)
2113{
2114 struct trace_event_file *file;
2115 struct trace_array *tr;
2116
2117 do_for_each_event_file_safe(tr, file) {
2118 if (file->event_call != call)
2119 continue;
2120
2121 remove_event_file_dir(file);
2122 /*
2123 * The do_for_each_event_file_safe() is
2124 * a double loop. After finding the call for this
2125 * trace_array, we use break to jump to the next
2126 * trace_array.
2127 */
2128 break;
2129 } while_for_each_event_file();
2130}
2131
2132static void event_remove(struct trace_event_call *call)
2133{
2134 struct trace_array *tr;
2135 struct trace_event_file *file;
2136
2137 do_for_each_event_file(tr, file) {
2138 if (file->event_call != call)
2139 continue;
2140 ftrace_event_enable_disable(file, 0);
2141 /*
2142 * The do_for_each_event_file() is
2143 * a double loop. After finding the call for this
2144 * trace_array, we use break to jump to the next
2145 * trace_array.
2146 */
2147 break;
2148 } while_for_each_event_file();
2149
2150 if (call->event.funcs)
2151 __unregister_trace_event(&call->event);
2152 remove_event_from_tracers(call);
2153 list_del(&call->list);
2154}
2155
2156static int event_init(struct trace_event_call *call)
2157{
2158 int ret = 0;
2159 const char *name;
2160
2161 name = trace_event_name(call);
2162 if (WARN_ON(!name))
2163 return -EINVAL;
2164
2165 if (call->class->raw_init) {
2166 ret = call->class->raw_init(call);
2167 if (ret < 0 && ret != -ENOSYS)
2168 pr_warn("Could not initialize trace events/%s\n", name);
2169 }
2170
2171 return ret;
2172}
2173
2174static int
2175__register_event(struct trace_event_call *call, struct module *mod)
2176{
2177 int ret;
2178
2179 ret = event_init(call);
2180 if (ret < 0)
2181 return ret;
2182
2183 list_add(&call->list, &ftrace_events);
2184 call->mod = mod;
2185
2186 return 0;
2187}
2188
2189static char *enum_replace(char *ptr, struct trace_enum_map *map, int len)
2190{
2191 int rlen;
2192 int elen;
2193
2194 /* Find the length of the enum value as a string */
2195 elen = snprintf(ptr, 0, "%ld", map->enum_value);
2196 /* Make sure there's enough room to replace the string with the value */
2197 if (len < elen)
2198 return NULL;
2199
2200 snprintf(ptr, elen + 1, "%ld", map->enum_value);
2201
2202 /* Get the rest of the string of ptr */
2203 rlen = strlen(ptr + len);
2204 memmove(ptr + elen, ptr + len, rlen);
2205 /* Make sure we end the new string */
2206 ptr[elen + rlen] = 0;
2207
2208 return ptr + elen;
2209}
2210
2211static void update_event_printk(struct trace_event_call *call,
2212 struct trace_enum_map *map)
2213{
2214 char *ptr;
2215 int quote = 0;
2216 int len = strlen(map->enum_string);
2217
2218 for (ptr = call->print_fmt; *ptr; ptr++) {
2219 if (*ptr == '\\') {
2220 ptr++;
2221 /* paranoid */
2222 if (!*ptr)
2223 break;
2224 continue;
2225 }
2226 if (*ptr == '"') {
2227 quote ^= 1;
2228 continue;
2229 }
2230 if (quote)
2231 continue;
2232 if (isdigit(*ptr)) {
2233 /* skip numbers */
2234 do {
2235 ptr++;
2236 /* Check for alpha chars like ULL */
2237 } while (isalnum(*ptr));
2238 if (!*ptr)
2239 break;
2240 /*
2241 * A number must have some kind of delimiter after
2242 * it, and we can ignore that too.
2243 */
2244 continue;
2245 }
2246 if (isalpha(*ptr) || *ptr == '_') {
2247 if (strncmp(map->enum_string, ptr, len) == 0 &&
2248 !isalnum(ptr[len]) && ptr[len] != '_') {
2249 ptr = enum_replace(ptr, map, len);
2250 /* Hmm, enum string smaller than value */
2251 if (WARN_ON_ONCE(!ptr))
2252 return;
2253 /*
2254 * No need to decrement here, as enum_replace()
2255 * returns the pointer to the character passed
2256 * the enum, and two enums can not be placed
2257 * back to back without something in between.
2258 * We can skip that something in between.
2259 */
2260 continue;
2261 }
2262 skip_more:
2263 do {
2264 ptr++;
2265 } while (isalnum(*ptr) || *ptr == '_');
2266 if (!*ptr)
2267 break;
2268 /*
2269 * If what comes after this variable is a '.' or
2270 * '->' then we can continue to ignore that string.
2271 */
2272 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2273 ptr += *ptr == '.' ? 1 : 2;
2274 if (!*ptr)
2275 break;
2276 goto skip_more;
2277 }
2278 /*
2279 * Once again, we can skip the delimiter that came
2280 * after the string.
2281 */
2282 continue;
2283 }
2284 }
2285}
2286
2287void trace_event_enum_update(struct trace_enum_map **map, int len)
2288{
2289 struct trace_event_call *call, *p;
2290 const char *last_system = NULL;
2291 int last_i;
2292 int i;
2293
2294 down_write(&trace_event_sem);
2295 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2296 /* events are usually grouped together with systems */
2297 if (!last_system || call->class->system != last_system) {
2298 last_i = 0;
2299 last_system = call->class->system;
2300 }
2301
2302 for (i = last_i; i < len; i++) {
2303 if (call->class->system == map[i]->system) {
2304 /* Save the first system if need be */
2305 if (!last_i)
2306 last_i = i;
2307 update_event_printk(call, map[i]);
2308 }
2309 }
2310 }
2311 up_write(&trace_event_sem);
2312}
2313
2314static struct trace_event_file *
2315trace_create_new_event(struct trace_event_call *call,
2316 struct trace_array *tr)
2317{
2318 struct trace_event_file *file;
2319
2320 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2321 if (!file)
2322 return NULL;
2323
2324 file->event_call = call;
2325 file->tr = tr;
2326 atomic_set(&file->sm_ref, 0);
2327 atomic_set(&file->tm_ref, 0);
2328 INIT_LIST_HEAD(&file->triggers);
2329 list_add(&file->list, &tr->events);
2330
2331 return file;
2332}
2333
2334/* Add an event to a trace directory */
2335static int
2336__trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2337{
2338 struct trace_event_file *file;
2339
2340 file = trace_create_new_event(call, tr);
2341 if (!file)
2342 return -ENOMEM;
2343
2344 return event_create_dir(tr->event_dir, file);
2345}
2346
2347/*
2348 * Just create a decriptor for early init. A descriptor is required
2349 * for enabling events at boot. We want to enable events before
2350 * the filesystem is initialized.
2351 */
2352static __init int
2353__trace_early_add_new_event(struct trace_event_call *call,
2354 struct trace_array *tr)
2355{
2356 struct trace_event_file *file;
2357
2358 file = trace_create_new_event(call, tr);
2359 if (!file)
2360 return -ENOMEM;
2361
2362 return 0;
2363}
2364
2365struct ftrace_module_file_ops;
2366static void __add_event_to_tracers(struct trace_event_call *call);
2367
2368/* Add an additional event_call dynamically */
2369int trace_add_event_call(struct trace_event_call *call)
2370{
2371 int ret;
2372 mutex_lock(&trace_types_lock);
2373 mutex_lock(&event_mutex);
2374
2375 ret = __register_event(call, NULL);
2376 if (ret >= 0)
2377 __add_event_to_tracers(call);
2378
2379 mutex_unlock(&event_mutex);
2380 mutex_unlock(&trace_types_lock);
2381 return ret;
2382}
2383
2384/*
2385 * Must be called under locking of trace_types_lock, event_mutex and
2386 * trace_event_sem.
2387 */
2388static void __trace_remove_event_call(struct trace_event_call *call)
2389{
2390 event_remove(call);
2391 trace_destroy_fields(call);
2392 free_event_filter(call->filter);
2393 call->filter = NULL;
2394}
2395
2396static int probe_remove_event_call(struct trace_event_call *call)
2397{
2398 struct trace_array *tr;
2399 struct trace_event_file *file;
2400
2401#ifdef CONFIG_PERF_EVENTS
2402 if (call->perf_refcount)
2403 return -EBUSY;
2404#endif
2405 do_for_each_event_file(tr, file) {
2406 if (file->event_call != call)
2407 continue;
2408 /*
2409 * We can't rely on ftrace_event_enable_disable(enable => 0)
2410 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2411 * TRACE_REG_UNREGISTER.
2412 */
2413 if (file->flags & EVENT_FILE_FL_ENABLED)
2414 return -EBUSY;
2415 /*
2416 * The do_for_each_event_file_safe() is
2417 * a double loop. After finding the call for this
2418 * trace_array, we use break to jump to the next
2419 * trace_array.
2420 */
2421 break;
2422 } while_for_each_event_file();
2423
2424 __trace_remove_event_call(call);
2425
2426 return 0;
2427}
2428
2429/* Remove an event_call */
2430int trace_remove_event_call(struct trace_event_call *call)
2431{
2432 int ret;
2433
2434 mutex_lock(&trace_types_lock);
2435 mutex_lock(&event_mutex);
2436 down_write(&trace_event_sem);
2437 ret = probe_remove_event_call(call);
2438 up_write(&trace_event_sem);
2439 mutex_unlock(&event_mutex);
2440 mutex_unlock(&trace_types_lock);
2441
2442 return ret;
2443}
2444
2445#define for_each_event(event, start, end) \
2446 for (event = start; \
2447 (unsigned long)event < (unsigned long)end; \
2448 event++)
2449
2450#ifdef CONFIG_MODULES
2451
2452static void trace_module_add_events(struct module *mod)
2453{
2454 struct trace_event_call **call, **start, **end;
2455
2456 if (!mod->num_trace_events)
2457 return;
2458
2459 /* Don't add infrastructure for mods without tracepoints */
2460 if (trace_module_has_bad_taint(mod)) {
2461 pr_err("%s: module has bad taint, not creating trace events\n",
2462 mod->name);
2463 return;
2464 }
2465
2466 start = mod->trace_events;
2467 end = mod->trace_events + mod->num_trace_events;
2468
2469 for_each_event(call, start, end) {
2470 __register_event(*call, mod);
2471 __add_event_to_tracers(*call);
2472 }
2473}
2474
2475static void trace_module_remove_events(struct module *mod)
2476{
2477 struct trace_event_call *call, *p;
2478 bool clear_trace = false;
2479
2480 down_write(&trace_event_sem);
2481 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2482 if (call->mod == mod) {
2483 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
2484 clear_trace = true;
2485 __trace_remove_event_call(call);
2486 }
2487 }
2488 up_write(&trace_event_sem);
2489
2490 /*
2491 * It is safest to reset the ring buffer if the module being unloaded
2492 * registered any events that were used. The only worry is if
2493 * a new module gets loaded, and takes on the same id as the events
2494 * of this module. When printing out the buffer, traced events left
2495 * over from this module may be passed to the new module events and
2496 * unexpected results may occur.
2497 */
2498 if (clear_trace)
2499 tracing_reset_all_online_cpus();
2500}
2501
2502static int trace_module_notify(struct notifier_block *self,
2503 unsigned long val, void *data)
2504{
2505 struct module *mod = data;
2506
2507 mutex_lock(&trace_types_lock);
2508 mutex_lock(&event_mutex);
2509 switch (val) {
2510 case MODULE_STATE_COMING:
2511 trace_module_add_events(mod);
2512 break;
2513 case MODULE_STATE_GOING:
2514 trace_module_remove_events(mod);
2515 break;
2516 }
2517 mutex_unlock(&event_mutex);
2518 mutex_unlock(&trace_types_lock);
2519
2520 return 0;
2521}
2522
2523static struct notifier_block trace_module_nb = {
2524 .notifier_call = trace_module_notify,
2525 .priority = 1, /* higher than trace.c module notify */
2526};
2527#endif /* CONFIG_MODULES */
2528
2529/* Create a new event directory structure for a trace directory. */
2530static void
2531__trace_add_event_dirs(struct trace_array *tr)
2532{
2533 struct trace_event_call *call;
2534 int ret;
2535
2536 list_for_each_entry(call, &ftrace_events, list) {
2537 ret = __trace_add_new_event(call, tr);
2538 if (ret < 0)
2539 pr_warn("Could not create directory for event %s\n",
2540 trace_event_name(call));
2541 }
2542}
2543
2544struct trace_event_file *
2545find_event_file(struct trace_array *tr, const char *system, const char *event)
2546{
2547 struct trace_event_file *file;
2548 struct trace_event_call *call;
2549 const char *name;
2550
2551 list_for_each_entry(file, &tr->events, list) {
2552
2553 call = file->event_call;
2554 name = trace_event_name(call);
2555
2556 if (!name || !call->class || !call->class->reg)
2557 continue;
2558
2559 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2560 continue;
2561
2562 if (strcmp(event, name) == 0 &&
2563 strcmp(system, call->class->system) == 0)
2564 return file;
2565 }
2566 return NULL;
2567}
2568
2569#ifdef CONFIG_DYNAMIC_FTRACE
2570
2571/* Avoid typos */
2572#define ENABLE_EVENT_STR "enable_event"
2573#define DISABLE_EVENT_STR "disable_event"
2574
2575struct event_probe_data {
2576 struct trace_event_file *file;
2577 unsigned long count;
2578 int ref;
2579 bool enable;
2580};
2581
2582static void
2583event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2584{
2585 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2586 struct event_probe_data *data = *pdata;
2587
2588 if (!data)
2589 return;
2590
2591 if (data->enable)
2592 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2593 else
2594 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2595}
2596
2597static void
2598event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2599{
2600 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2601 struct event_probe_data *data = *pdata;
2602
2603 if (!data)
2604 return;
2605
2606 if (!data->count)
2607 return;
2608
2609 /* Skip if the event is in a state we want to switch to */
2610 if (data->enable == !(data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
2611 return;
2612
2613 if (data->count != -1)
2614 (data->count)--;
2615
2616 event_enable_probe(ip, parent_ip, _data);
2617}
2618
2619static int
2620event_enable_print(struct seq_file *m, unsigned long ip,
2621 struct ftrace_probe_ops *ops, void *_data)
2622{
2623 struct event_probe_data *data = _data;
2624
2625 seq_printf(m, "%ps:", (void *)ip);
2626
2627 seq_printf(m, "%s:%s:%s",
2628 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2629 data->file->event_call->class->system,
2630 trace_event_name(data->file->event_call));
2631
2632 if (data->count == -1)
2633 seq_puts(m, ":unlimited\n");
2634 else
2635 seq_printf(m, ":count=%ld\n", data->count);
2636
2637 return 0;
2638}
2639
2640static int
2641event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
2642 void **_data)
2643{
2644 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2645 struct event_probe_data *data = *pdata;
2646
2647 data->ref++;
2648 return 0;
2649}
2650
2651static void
2652event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
2653 void **_data)
2654{
2655 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2656 struct event_probe_data *data = *pdata;
2657
2658 if (WARN_ON_ONCE(data->ref <= 0))
2659 return;
2660
2661 data->ref--;
2662 if (!data->ref) {
2663 /* Remove the SOFT_MODE flag */
2664 __ftrace_event_enable_disable(data->file, 0, 1);
2665 module_put(data->file->event_call->mod);
2666 kfree(data);
2667 }
2668 *pdata = NULL;
2669}
2670
2671static struct ftrace_probe_ops event_enable_probe_ops = {
2672 .func = event_enable_probe,
2673 .print = event_enable_print,
2674 .init = event_enable_init,
2675 .free = event_enable_free,
2676};
2677
2678static struct ftrace_probe_ops event_enable_count_probe_ops = {
2679 .func = event_enable_count_probe,
2680 .print = event_enable_print,
2681 .init = event_enable_init,
2682 .free = event_enable_free,
2683};
2684
2685static struct ftrace_probe_ops event_disable_probe_ops = {
2686 .func = event_enable_probe,
2687 .print = event_enable_print,
2688 .init = event_enable_init,
2689 .free = event_enable_free,
2690};
2691
2692static struct ftrace_probe_ops event_disable_count_probe_ops = {
2693 .func = event_enable_count_probe,
2694 .print = event_enable_print,
2695 .init = event_enable_init,
2696 .free = event_enable_free,
2697};
2698
2699static int
2700event_enable_func(struct ftrace_hash *hash,
2701 char *glob, char *cmd, char *param, int enabled)
2702{
2703 struct trace_array *tr = top_trace_array();
2704 struct trace_event_file *file;
2705 struct ftrace_probe_ops *ops;
2706 struct event_probe_data *data;
2707 const char *system;
2708 const char *event;
2709 char *number;
2710 bool enable;
2711 int ret;
2712
2713 if (!tr)
2714 return -ENODEV;
2715
2716 /* hash funcs only work with set_ftrace_filter */
2717 if (!enabled || !param)
2718 return -EINVAL;
2719
2720 system = strsep(¶m, ":");
2721 if (!param)
2722 return -EINVAL;
2723
2724 event = strsep(¶m, ":");
2725
2726 mutex_lock(&event_mutex);
2727
2728 ret = -EINVAL;
2729 file = find_event_file(tr, system, event);
2730 if (!file)
2731 goto out;
2732
2733 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2734
2735 if (enable)
2736 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2737 else
2738 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2739
2740 if (glob[0] == '!') {
2741 unregister_ftrace_function_probe_func(glob+1, ops);
2742 ret = 0;
2743 goto out;
2744 }
2745
2746 ret = -ENOMEM;
2747 data = kzalloc(sizeof(*data), GFP_KERNEL);
2748 if (!data)
2749 goto out;
2750
2751 data->enable = enable;
2752 data->count = -1;
2753 data->file = file;
2754
2755 if (!param)
2756 goto out_reg;
2757
2758 number = strsep(¶m, ":");
2759
2760 ret = -EINVAL;
2761 if (!strlen(number))
2762 goto out_free;
2763
2764 /*
2765 * We use the callback data field (which is a pointer)
2766 * as our counter.
2767 */
2768 ret = kstrtoul(number, 0, &data->count);
2769 if (ret)
2770 goto out_free;
2771
2772 out_reg:
2773 /* Don't let event modules unload while probe registered */
2774 ret = try_module_get(file->event_call->mod);
2775 if (!ret) {
2776 ret = -EBUSY;
2777 goto out_free;
2778 }
2779
2780 ret = __ftrace_event_enable_disable(file, 1, 1);
2781 if (ret < 0)
2782 goto out_put;
2783 ret = register_ftrace_function_probe(glob, ops, data);
2784 /*
2785 * The above returns on success the # of functions enabled,
2786 * but if it didn't find any functions it returns zero.
2787 * Consider no functions a failure too.
2788 */
2789 if (!ret) {
2790 ret = -ENOENT;
2791 goto out_disable;
2792 } else if (ret < 0)
2793 goto out_disable;
2794 /* Just return zero, not the number of enabled functions */
2795 ret = 0;
2796 out:
2797 mutex_unlock(&event_mutex);
2798 return ret;
2799
2800 out_disable:
2801 __ftrace_event_enable_disable(file, 0, 1);
2802 out_put:
2803 module_put(file->event_call->mod);
2804 out_free:
2805 kfree(data);
2806 goto out;
2807}
2808
2809static struct ftrace_func_command event_enable_cmd = {
2810 .name = ENABLE_EVENT_STR,
2811 .func = event_enable_func,
2812};
2813
2814static struct ftrace_func_command event_disable_cmd = {
2815 .name = DISABLE_EVENT_STR,
2816 .func = event_enable_func,
2817};
2818
2819static __init int register_event_cmds(void)
2820{
2821 int ret;
2822
2823 ret = register_ftrace_command(&event_enable_cmd);
2824 if (WARN_ON(ret < 0))
2825 return ret;
2826 ret = register_ftrace_command(&event_disable_cmd);
2827 if (WARN_ON(ret < 0))
2828 unregister_ftrace_command(&event_enable_cmd);
2829 return ret;
2830}
2831#else
2832static inline int register_event_cmds(void) { return 0; }
2833#endif /* CONFIG_DYNAMIC_FTRACE */
2834
2835/*
2836 * The top level array has already had its trace_event_file
2837 * descriptors created in order to allow for early events to
2838 * be recorded. This function is called after the tracefs has been
2839 * initialized, and we now have to create the files associated
2840 * to the events.
2841 */
2842static __init void
2843__trace_early_add_event_dirs(struct trace_array *tr)
2844{
2845 struct trace_event_file *file;
2846 int ret;
2847
2848
2849 list_for_each_entry(file, &tr->events, list) {
2850 ret = event_create_dir(tr->event_dir, file);
2851 if (ret < 0)
2852 pr_warn("Could not create directory for event %s\n",
2853 trace_event_name(file->event_call));
2854 }
2855}
2856
2857/*
2858 * For early boot up, the top trace array requires to have
2859 * a list of events that can be enabled. This must be done before
2860 * the filesystem is set up in order to allow events to be traced
2861 * early.
2862 */
2863static __init void
2864__trace_early_add_events(struct trace_array *tr)
2865{
2866 struct trace_event_call *call;
2867 int ret;
2868
2869 list_for_each_entry(call, &ftrace_events, list) {
2870 /* Early boot up should not have any modules loaded */
2871 if (WARN_ON_ONCE(call->mod))
2872 continue;
2873
2874 ret = __trace_early_add_new_event(call, tr);
2875 if (ret < 0)
2876 pr_warn("Could not create early event %s\n",
2877 trace_event_name(call));
2878 }
2879}
2880
2881/* Remove the event directory structure for a trace directory. */
2882static void
2883__trace_remove_event_dirs(struct trace_array *tr)
2884{
2885 struct trace_event_file *file, *next;
2886
2887 list_for_each_entry_safe(file, next, &tr->events, list)
2888 remove_event_file_dir(file);
2889}
2890
2891static void __add_event_to_tracers(struct trace_event_call *call)
2892{
2893 struct trace_array *tr;
2894
2895 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2896 __trace_add_new_event(call, tr);
2897}
2898
2899extern struct trace_event_call *__start_ftrace_events[];
2900extern struct trace_event_call *__stop_ftrace_events[];
2901
2902static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2903
2904static __init int setup_trace_event(char *str)
2905{
2906 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2907 ring_buffer_expanded = true;
2908 tracing_selftest_disabled = true;
2909
2910 return 1;
2911}
2912__setup("trace_event=", setup_trace_event);
2913
2914/* Expects to have event_mutex held when called */
2915static int
2916create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2917{
2918 struct dentry *d_events;
2919 struct dentry *entry;
2920
2921 entry = tracefs_create_file("set_event", 0644, parent,
2922 tr, &ftrace_set_event_fops);
2923 if (!entry) {
2924 pr_warn("Could not create tracefs 'set_event' entry\n");
2925 return -ENOMEM;
2926 }
2927
2928 d_events = tracefs_create_dir("events", parent);
2929 if (!d_events) {
2930 pr_warn("Could not create tracefs 'events' directory\n");
2931 return -ENOMEM;
2932 }
2933
2934 entry = tracefs_create_file("set_event_pid", 0644, parent,
2935 tr, &ftrace_set_event_pid_fops);
2936
2937 /* ring buffer internal formats */
2938 trace_create_file("header_page", 0444, d_events,
2939 ring_buffer_print_page_header,
2940 &ftrace_show_header_fops);
2941
2942 trace_create_file("header_event", 0444, d_events,
2943 ring_buffer_print_entry_header,
2944 &ftrace_show_header_fops);
2945
2946 trace_create_file("enable", 0644, d_events,
2947 tr, &ftrace_tr_enable_fops);
2948
2949 tr->event_dir = d_events;
2950
2951 return 0;
2952}
2953
2954/**
2955 * event_trace_add_tracer - add a instance of a trace_array to events
2956 * @parent: The parent dentry to place the files/directories for events in
2957 * @tr: The trace array associated with these events
2958 *
2959 * When a new instance is created, it needs to set up its events
2960 * directory, as well as other files associated with events. It also
2961 * creates the event hierachry in the @parent/events directory.
2962 *
2963 * Returns 0 on success.
2964 */
2965int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2966{
2967 int ret;
2968
2969 mutex_lock(&event_mutex);
2970
2971 ret = create_event_toplevel_files(parent, tr);
2972 if (ret)
2973 goto out_unlock;
2974
2975 down_write(&trace_event_sem);
2976 __trace_add_event_dirs(tr);
2977 up_write(&trace_event_sem);
2978
2979 out_unlock:
2980 mutex_unlock(&event_mutex);
2981
2982 return ret;
2983}
2984
2985/*
2986 * The top trace array already had its file descriptors created.
2987 * Now the files themselves need to be created.
2988 */
2989static __init int
2990early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2991{
2992 int ret;
2993
2994 mutex_lock(&event_mutex);
2995
2996 ret = create_event_toplevel_files(parent, tr);
2997 if (ret)
2998 goto out_unlock;
2999
3000 down_write(&trace_event_sem);
3001 __trace_early_add_event_dirs(tr);
3002 up_write(&trace_event_sem);
3003
3004 out_unlock:
3005 mutex_unlock(&event_mutex);
3006
3007 return ret;
3008}
3009
3010int event_trace_del_tracer(struct trace_array *tr)
3011{
3012 mutex_lock(&event_mutex);
3013
3014 /* Disable any event triggers and associated soft-disabled events */
3015 clear_event_triggers(tr);
3016
3017 /* Clear the pid list */
3018 __ftrace_clear_event_pids(tr);
3019
3020 /* Disable any running events */
3021 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3022
3023 /* Access to events are within rcu_read_lock_sched() */
3024 synchronize_sched();
3025
3026 down_write(&trace_event_sem);
3027 __trace_remove_event_dirs(tr);
3028 tracefs_remove_recursive(tr->event_dir);
3029 up_write(&trace_event_sem);
3030
3031 tr->event_dir = NULL;
3032
3033 mutex_unlock(&event_mutex);
3034
3035 return 0;
3036}
3037
3038static __init int event_trace_memsetup(void)
3039{
3040 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3041 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3042 return 0;
3043}
3044
3045static __init void
3046early_enable_events(struct trace_array *tr, bool disable_first)
3047{
3048 char *buf = bootup_event_buf;
3049 char *token;
3050 int ret;
3051
3052 while (true) {
3053 token = strsep(&buf, ",");
3054
3055 if (!token)
3056 break;
3057
3058 if (*token) {
3059 /* Restarting syscalls requires that we stop them first */
3060 if (disable_first)
3061 ftrace_set_clr_event(tr, token, 0);
3062
3063 ret = ftrace_set_clr_event(tr, token, 1);
3064 if (ret)
3065 pr_warn("Failed to enable trace event: %s\n", token);
3066 }
3067
3068 /* Put back the comma to allow this to be called again */
3069 if (buf)
3070 *(buf - 1) = ',';
3071 }
3072}
3073
3074static __init int event_trace_enable(void)
3075{
3076 struct trace_array *tr = top_trace_array();
3077 struct trace_event_call **iter, *call;
3078 int ret;
3079
3080 if (!tr)
3081 return -ENODEV;
3082
3083 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3084
3085 call = *iter;
3086 ret = event_init(call);
3087 if (!ret)
3088 list_add(&call->list, &ftrace_events);
3089 }
3090
3091 /*
3092 * We need the top trace array to have a working set of trace
3093 * points at early init, before the debug files and directories
3094 * are created. Create the file entries now, and attach them
3095 * to the actual file dentries later.
3096 */
3097 __trace_early_add_events(tr);
3098
3099 early_enable_events(tr, false);
3100
3101 trace_printk_start_comm();
3102
3103 register_event_cmds();
3104
3105 register_trigger_cmds();
3106
3107 return 0;
3108}
3109
3110/*
3111 * event_trace_enable() is called from trace_event_init() first to
3112 * initialize events and perhaps start any events that are on the
3113 * command line. Unfortunately, there are some events that will not
3114 * start this early, like the system call tracepoints that need
3115 * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
3116 * is called before pid 1 starts, and this flag is never set, making
3117 * the syscall tracepoint never get reached, but the event is enabled
3118 * regardless (and not doing anything).
3119 */
3120static __init int event_trace_enable_again(void)
3121{
3122 struct trace_array *tr;
3123
3124 tr = top_trace_array();
3125 if (!tr)
3126 return -ENODEV;
3127
3128 early_enable_events(tr, true);
3129
3130 return 0;
3131}
3132
3133early_initcall(event_trace_enable_again);
3134
3135static __init int event_trace_init(void)
3136{
3137 struct trace_array *tr;
3138 struct dentry *d_tracer;
3139 struct dentry *entry;
3140 int ret;
3141
3142 tr = top_trace_array();
3143 if (!tr)
3144 return -ENODEV;
3145
3146 d_tracer = tracing_init_dentry();
3147 if (IS_ERR(d_tracer))
3148 return 0;
3149
3150 entry = tracefs_create_file("available_events", 0444, d_tracer,
3151 tr, &ftrace_avail_fops);
3152 if (!entry)
3153 pr_warn("Could not create tracefs 'available_events' entry\n");
3154
3155 if (trace_define_generic_fields())
3156 pr_warn("tracing: Failed to allocated generic fields");
3157
3158 if (trace_define_common_fields())
3159 pr_warn("tracing: Failed to allocate common fields");
3160
3161 ret = early_event_add_tracer(d_tracer, tr);
3162 if (ret)
3163 return ret;
3164
3165#ifdef CONFIG_MODULES
3166 ret = register_module_notifier(&trace_module_nb);
3167 if (ret)
3168 pr_warn("Failed to register trace events module notifier\n");
3169#endif
3170 return 0;
3171}
3172
3173void __init trace_event_init(void)
3174{
3175 event_trace_memsetup();
3176 init_ftrace_syscalls();
3177 event_trace_enable();
3178}
3179
3180fs_initcall(event_trace_init);
3181
3182#ifdef CONFIG_FTRACE_STARTUP_TEST
3183
3184static DEFINE_SPINLOCK(test_spinlock);
3185static DEFINE_SPINLOCK(test_spinlock_irq);
3186static DEFINE_MUTEX(test_mutex);
3187
3188static __init void test_work(struct work_struct *dummy)
3189{
3190 spin_lock(&test_spinlock);
3191 spin_lock_irq(&test_spinlock_irq);
3192 udelay(1);
3193 spin_unlock_irq(&test_spinlock_irq);
3194 spin_unlock(&test_spinlock);
3195
3196 mutex_lock(&test_mutex);
3197 msleep(1);
3198 mutex_unlock(&test_mutex);
3199}
3200
3201static __init int event_test_thread(void *unused)
3202{
3203 void *test_malloc;
3204
3205 test_malloc = kmalloc(1234, GFP_KERNEL);
3206 if (!test_malloc)
3207 pr_info("failed to kmalloc\n");
3208
3209 schedule_on_each_cpu(test_work);
3210
3211 kfree(test_malloc);
3212
3213 set_current_state(TASK_INTERRUPTIBLE);
3214 while (!kthread_should_stop()) {
3215 schedule();
3216 set_current_state(TASK_INTERRUPTIBLE);
3217 }
3218 __set_current_state(TASK_RUNNING);
3219
3220 return 0;
3221}
3222
3223/*
3224 * Do various things that may trigger events.
3225 */
3226static __init void event_test_stuff(void)
3227{
3228 struct task_struct *test_thread;
3229
3230 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3231 msleep(1);
3232 kthread_stop(test_thread);
3233}
3234
3235/*
3236 * For every trace event defined, we will test each trace point separately,
3237 * and then by groups, and finally all trace points.
3238 */
3239static __init void event_trace_self_tests(void)
3240{
3241 struct trace_subsystem_dir *dir;
3242 struct trace_event_file *file;
3243 struct trace_event_call *call;
3244 struct event_subsystem *system;
3245 struct trace_array *tr;
3246 int ret;
3247
3248 tr = top_trace_array();
3249 if (!tr)
3250 return;
3251
3252 pr_info("Running tests on trace events:\n");
3253
3254 list_for_each_entry(file, &tr->events, list) {
3255
3256 call = file->event_call;
3257
3258 /* Only test those that have a probe */
3259 if (!call->class || !call->class->probe)
3260 continue;
3261
3262/*
3263 * Testing syscall events here is pretty useless, but
3264 * we still do it if configured. But this is time consuming.
3265 * What we really need is a user thread to perform the
3266 * syscalls as we test.
3267 */
3268#ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3269 if (call->class->system &&
3270 strcmp(call->class->system, "syscalls") == 0)
3271 continue;
3272#endif
3273
3274 pr_info("Testing event %s: ", trace_event_name(call));
3275
3276 /*
3277 * If an event is already enabled, someone is using
3278 * it and the self test should not be on.
3279 */
3280 if (file->flags & EVENT_FILE_FL_ENABLED) {
3281 pr_warn("Enabled event during self test!\n");
3282 WARN_ON_ONCE(1);
3283 continue;
3284 }
3285
3286 ftrace_event_enable_disable(file, 1);
3287 event_test_stuff();
3288 ftrace_event_enable_disable(file, 0);
3289
3290 pr_cont("OK\n");
3291 }
3292
3293 /* Now test at the sub system level */
3294
3295 pr_info("Running tests on trace event systems:\n");
3296
3297 list_for_each_entry(dir, &tr->systems, list) {
3298
3299 system = dir->subsystem;
3300
3301 /* the ftrace system is special, skip it */
3302 if (strcmp(system->name, "ftrace") == 0)
3303 continue;
3304
3305 pr_info("Testing event system %s: ", system->name);
3306
3307 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3308 if (WARN_ON_ONCE(ret)) {
3309 pr_warn("error enabling system %s\n",
3310 system->name);
3311 continue;
3312 }
3313
3314 event_test_stuff();
3315
3316 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3317 if (WARN_ON_ONCE(ret)) {
3318 pr_warn("error disabling system %s\n",
3319 system->name);
3320 continue;
3321 }
3322
3323 pr_cont("OK\n");
3324 }
3325
3326 /* Test with all events enabled */
3327
3328 pr_info("Running tests on all trace events:\n");
3329 pr_info("Testing all events: ");
3330
3331 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3332 if (WARN_ON_ONCE(ret)) {
3333 pr_warn("error enabling all events\n");
3334 return;
3335 }
3336
3337 event_test_stuff();
3338
3339 /* reset sysname */
3340 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3341 if (WARN_ON_ONCE(ret)) {
3342 pr_warn("error disabling all events\n");
3343 return;
3344 }
3345
3346 pr_cont("OK\n");
3347}
3348
3349#ifdef CONFIG_FUNCTION_TRACER
3350
3351static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3352
3353static struct trace_array *event_tr;
3354
3355static void __init
3356function_test_events_call(unsigned long ip, unsigned long parent_ip,
3357 struct ftrace_ops *op, struct pt_regs *pt_regs)
3358{
3359 struct ring_buffer_event *event;
3360 struct ring_buffer *buffer;
3361 struct ftrace_entry *entry;
3362 unsigned long flags;
3363 long disabled;
3364 int cpu;
3365 int pc;
3366
3367 pc = preempt_count();
3368 preempt_disable_notrace();
3369 cpu = raw_smp_processor_id();
3370 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3371
3372 if (disabled != 1)
3373 goto out;
3374
3375 local_save_flags(flags);
3376
3377 event = trace_current_buffer_lock_reserve(&buffer,
3378 TRACE_FN, sizeof(*entry),
3379 flags, pc);
3380 if (!event)
3381 goto out;
3382 entry = ring_buffer_event_data(event);
3383 entry->ip = ip;
3384 entry->parent_ip = parent_ip;
3385
3386 trace_buffer_unlock_commit(event_tr, buffer, event, flags, pc);
3387
3388 out:
3389 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3390 preempt_enable_notrace();
3391}
3392
3393static struct ftrace_ops trace_ops __initdata =
3394{
3395 .func = function_test_events_call,
3396 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
3397};
3398
3399static __init void event_trace_self_test_with_function(void)
3400{
3401 int ret;
3402 event_tr = top_trace_array();
3403 if (WARN_ON(!event_tr))
3404 return;
3405 ret = register_ftrace_function(&trace_ops);
3406 if (WARN_ON(ret < 0)) {
3407 pr_info("Failed to enable function tracer for event tests\n");
3408 return;
3409 }
3410 pr_info("Running tests again, along with the function tracer\n");
3411 event_trace_self_tests();
3412 unregister_ftrace_function(&trace_ops);
3413}
3414#else
3415static __init void event_trace_self_test_with_function(void)
3416{
3417}
3418#endif
3419
3420static __init int event_trace_self_tests_init(void)
3421{
3422 if (!tracing_selftest_disabled) {
3423 event_trace_self_tests();
3424 event_trace_self_test_with_function();
3425 }
3426
3427 return 0;
3428}
3429
3430late_initcall(event_trace_self_tests_init);
3431
3432#endif
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * event tracer
4 *
5 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
6 *
7 * - Added format output of fields of the trace point.
8 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
9 *
10 */
11
12#define pr_fmt(fmt) fmt
13
14#include <linux/workqueue.h>
15#include <linux/security.h>
16#include <linux/spinlock.h>
17#include <linux/kthread.h>
18#include <linux/tracefs.h>
19#include <linux/uaccess.h>
20#include <linux/module.h>
21#include <linux/ctype.h>
22#include <linux/sort.h>
23#include <linux/slab.h>
24#include <linux/delay.h>
25
26#include <trace/events/sched.h>
27#include <trace/syscall.h>
28
29#include <asm/setup.h>
30
31#include "trace_output.h"
32
33#undef TRACE_SYSTEM
34#define TRACE_SYSTEM "TRACE_SYSTEM"
35
36DEFINE_MUTEX(event_mutex);
37
38LIST_HEAD(ftrace_events);
39static LIST_HEAD(ftrace_generic_fields);
40static LIST_HEAD(ftrace_common_fields);
41static bool eventdir_initialized;
42
43#define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
44
45static struct kmem_cache *field_cachep;
46static struct kmem_cache *file_cachep;
47
48static inline int system_refcount(struct event_subsystem *system)
49{
50 return system->ref_count;
51}
52
53static int system_refcount_inc(struct event_subsystem *system)
54{
55 return system->ref_count++;
56}
57
58static int system_refcount_dec(struct event_subsystem *system)
59{
60 return --system->ref_count;
61}
62
63/* Double loops, do not use break, only goto's work */
64#define do_for_each_event_file(tr, file) \
65 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
66 list_for_each_entry(file, &tr->events, list)
67
68#define do_for_each_event_file_safe(tr, file) \
69 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
70 struct trace_event_file *___n; \
71 list_for_each_entry_safe(file, ___n, &tr->events, list)
72
73#define while_for_each_event_file() \
74 }
75
76static struct ftrace_event_field *
77__find_event_field(struct list_head *head, char *name)
78{
79 struct ftrace_event_field *field;
80
81 list_for_each_entry(field, head, link) {
82 if (!strcmp(field->name, name))
83 return field;
84 }
85
86 return NULL;
87}
88
89struct ftrace_event_field *
90trace_find_event_field(struct trace_event_call *call, char *name)
91{
92 struct ftrace_event_field *field;
93 struct list_head *head;
94
95 head = trace_get_fields(call);
96 field = __find_event_field(head, name);
97 if (field)
98 return field;
99
100 field = __find_event_field(&ftrace_generic_fields, name);
101 if (field)
102 return field;
103
104 return __find_event_field(&ftrace_common_fields, name);
105}
106
107static int __trace_define_field(struct list_head *head, const char *type,
108 const char *name, int offset, int size,
109 int is_signed, int filter_type)
110{
111 struct ftrace_event_field *field;
112
113 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
114 if (!field)
115 return -ENOMEM;
116
117 field->name = name;
118 field->type = type;
119
120 if (filter_type == FILTER_OTHER)
121 field->filter_type = filter_assign_type(type);
122 else
123 field->filter_type = filter_type;
124
125 field->offset = offset;
126 field->size = size;
127 field->is_signed = is_signed;
128
129 list_add(&field->link, head);
130
131 return 0;
132}
133
134int trace_define_field(struct trace_event_call *call, const char *type,
135 const char *name, int offset, int size, int is_signed,
136 int filter_type)
137{
138 struct list_head *head;
139
140 if (WARN_ON(!call->class))
141 return 0;
142
143 head = trace_get_fields(call);
144 return __trace_define_field(head, type, name, offset, size,
145 is_signed, filter_type);
146}
147EXPORT_SYMBOL_GPL(trace_define_field);
148
149#define __generic_field(type, item, filter_type) \
150 ret = __trace_define_field(&ftrace_generic_fields, #type, \
151 #item, 0, 0, is_signed_type(type), \
152 filter_type); \
153 if (ret) \
154 return ret;
155
156#define __common_field(type, item) \
157 ret = __trace_define_field(&ftrace_common_fields, #type, \
158 "common_" #item, \
159 offsetof(typeof(ent), item), \
160 sizeof(ent.item), \
161 is_signed_type(type), FILTER_OTHER); \
162 if (ret) \
163 return ret;
164
165static int trace_define_generic_fields(void)
166{
167 int ret;
168
169 __generic_field(int, CPU, FILTER_CPU);
170 __generic_field(int, cpu, FILTER_CPU);
171 __generic_field(char *, COMM, FILTER_COMM);
172 __generic_field(char *, comm, FILTER_COMM);
173
174 return ret;
175}
176
177static int trace_define_common_fields(void)
178{
179 int ret;
180 struct trace_entry ent;
181
182 __common_field(unsigned short, type);
183 __common_field(unsigned char, flags);
184 __common_field(unsigned char, preempt_count);
185 __common_field(int, pid);
186
187 return ret;
188}
189
190static void trace_destroy_fields(struct trace_event_call *call)
191{
192 struct ftrace_event_field *field, *next;
193 struct list_head *head;
194
195 head = trace_get_fields(call);
196 list_for_each_entry_safe(field, next, head, link) {
197 list_del(&field->link);
198 kmem_cache_free(field_cachep, field);
199 }
200}
201
202/*
203 * run-time version of trace_event_get_offsets_<call>() that returns the last
204 * accessible offset of trace fields excluding __dynamic_array bytes
205 */
206int trace_event_get_offsets(struct trace_event_call *call)
207{
208 struct ftrace_event_field *tail;
209 struct list_head *head;
210
211 head = trace_get_fields(call);
212 /*
213 * head->next points to the last field with the largest offset,
214 * since it was added last by trace_define_field()
215 */
216 tail = list_first_entry(head, struct ftrace_event_field, link);
217 return tail->offset + tail->size;
218}
219
220/*
221 * Check if the referenced field is an array and return true,
222 * as arrays are OK to dereference.
223 */
224static bool test_field(const char *fmt, struct trace_event_call *call)
225{
226 struct trace_event_fields *field = call->class->fields_array;
227 const char *array_descriptor;
228 const char *p = fmt;
229 int len;
230
231 if (!(len = str_has_prefix(fmt, "REC->")))
232 return false;
233 fmt += len;
234 for (p = fmt; *p; p++) {
235 if (!isalnum(*p) && *p != '_')
236 break;
237 }
238 len = p - fmt;
239
240 for (; field->type; field++) {
241 if (strncmp(field->name, fmt, len) ||
242 field->name[len])
243 continue;
244 array_descriptor = strchr(field->type, '[');
245 /* This is an array and is OK to dereference. */
246 return array_descriptor != NULL;
247 }
248 return false;
249}
250
251/*
252 * Examine the print fmt of the event looking for unsafe dereference
253 * pointers using %p* that could be recorded in the trace event and
254 * much later referenced after the pointer was freed. Dereferencing
255 * pointers are OK, if it is dereferenced into the event itself.
256 */
257static void test_event_printk(struct trace_event_call *call)
258{
259 u64 dereference_flags = 0;
260 bool first = true;
261 const char *fmt, *c, *r, *a;
262 int parens = 0;
263 char in_quote = 0;
264 int start_arg = 0;
265 int arg = 0;
266 int i;
267
268 fmt = call->print_fmt;
269
270 if (!fmt)
271 return;
272
273 for (i = 0; fmt[i]; i++) {
274 switch (fmt[i]) {
275 case '\\':
276 i++;
277 if (!fmt[i])
278 return;
279 continue;
280 case '"':
281 case '\'':
282 /*
283 * The print fmt starts with a string that
284 * is processed first to find %p* usage,
285 * then after the first string, the print fmt
286 * contains arguments that are used to check
287 * if the dereferenced %p* usage is safe.
288 */
289 if (first) {
290 if (fmt[i] == '\'')
291 continue;
292 if (in_quote) {
293 arg = 0;
294 first = false;
295 /*
296 * If there was no %p* uses
297 * the fmt is OK.
298 */
299 if (!dereference_flags)
300 return;
301 }
302 }
303 if (in_quote) {
304 if (in_quote == fmt[i])
305 in_quote = 0;
306 } else {
307 in_quote = fmt[i];
308 }
309 continue;
310 case '%':
311 if (!first || !in_quote)
312 continue;
313 i++;
314 if (!fmt[i])
315 return;
316 switch (fmt[i]) {
317 case '%':
318 continue;
319 case 'p':
320 /* Find dereferencing fields */
321 switch (fmt[i + 1]) {
322 case 'B': case 'R': case 'r':
323 case 'b': case 'M': case 'm':
324 case 'I': case 'i': case 'E':
325 case 'U': case 'V': case 'N':
326 case 'a': case 'd': case 'D':
327 case 'g': case 't': case 'C':
328 case 'O': case 'f':
329 if (WARN_ONCE(arg == 63,
330 "Too many args for event: %s",
331 trace_event_name(call)))
332 return;
333 dereference_flags |= 1ULL << arg;
334 }
335 break;
336 default:
337 {
338 bool star = false;
339 int j;
340
341 /* Increment arg if %*s exists. */
342 for (j = 0; fmt[i + j]; j++) {
343 if (isdigit(fmt[i + j]) ||
344 fmt[i + j] == '.')
345 continue;
346 if (fmt[i + j] == '*') {
347 star = true;
348 continue;
349 }
350 if ((fmt[i + j] == 's') && star)
351 arg++;
352 break;
353 }
354 break;
355 } /* default */
356
357 } /* switch */
358 arg++;
359 continue;
360 case '(':
361 if (in_quote)
362 continue;
363 parens++;
364 continue;
365 case ')':
366 if (in_quote)
367 continue;
368 parens--;
369 if (WARN_ONCE(parens < 0,
370 "Paren mismatch for event: %s\narg='%s'\n%*s",
371 trace_event_name(call),
372 fmt + start_arg,
373 (i - start_arg) + 5, "^"))
374 return;
375 continue;
376 case ',':
377 if (in_quote || parens)
378 continue;
379 i++;
380 while (isspace(fmt[i]))
381 i++;
382 start_arg = i;
383 if (!(dereference_flags & (1ULL << arg)))
384 goto next_arg;
385
386 /* Find the REC-> in the argument */
387 c = strchr(fmt + i, ',');
388 r = strstr(fmt + i, "REC->");
389 if (r && (!c || r < c)) {
390 /*
391 * Addresses of events on the buffer,
392 * or an array on the buffer is
393 * OK to dereference.
394 * There's ways to fool this, but
395 * this is to catch common mistakes,
396 * not malicious code.
397 */
398 a = strchr(fmt + i, '&');
399 if ((a && (a < r)) || test_field(r, call))
400 dereference_flags &= ~(1ULL << arg);
401 }
402 next_arg:
403 i--;
404 arg++;
405 }
406 }
407
408 /*
409 * If you triggered the below warning, the trace event reported
410 * uses an unsafe dereference pointer %p*. As the data stored
411 * at the trace event time may no longer exist when the trace
412 * event is printed, dereferencing to the original source is
413 * unsafe. The source of the dereference must be copied into the
414 * event itself, and the dereference must access the copy instead.
415 */
416 if (WARN_ON_ONCE(dereference_flags)) {
417 arg = 1;
418 while (!(dereference_flags & 1)) {
419 dereference_flags >>= 1;
420 arg++;
421 }
422 pr_warn("event %s has unsafe dereference of argument %d\n",
423 trace_event_name(call), arg);
424 pr_warn("print_fmt: %s\n", fmt);
425 }
426}
427
428int trace_event_raw_init(struct trace_event_call *call)
429{
430 int id;
431
432 id = register_trace_event(&call->event);
433 if (!id)
434 return -ENODEV;
435
436 test_event_printk(call);
437
438 return 0;
439}
440EXPORT_SYMBOL_GPL(trace_event_raw_init);
441
442bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
443{
444 struct trace_array *tr = trace_file->tr;
445 struct trace_array_cpu *data;
446 struct trace_pid_list *no_pid_list;
447 struct trace_pid_list *pid_list;
448
449 pid_list = rcu_dereference_raw(tr->filtered_pids);
450 no_pid_list = rcu_dereference_raw(tr->filtered_no_pids);
451
452 if (!pid_list && !no_pid_list)
453 return false;
454
455 data = this_cpu_ptr(tr->array_buffer.data);
456
457 return data->ignore_pid;
458}
459EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
460
461void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
462 struct trace_event_file *trace_file,
463 unsigned long len)
464{
465 struct trace_event_call *event_call = trace_file->event_call;
466
467 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
468 trace_event_ignore_this_pid(trace_file))
469 return NULL;
470
471 /*
472 * If CONFIG_PREEMPTION is enabled, then the tracepoint itself disables
473 * preemption (adding one to the preempt_count). Since we are
474 * interested in the preempt_count at the time the tracepoint was
475 * hit, we need to subtract one to offset the increment.
476 */
477 fbuffer->trace_ctx = tracing_gen_ctx_dec();
478 fbuffer->trace_file = trace_file;
479
480 fbuffer->event =
481 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
482 event_call->event.type, len,
483 fbuffer->trace_ctx);
484 if (!fbuffer->event)
485 return NULL;
486
487 fbuffer->regs = NULL;
488 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
489 return fbuffer->entry;
490}
491EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
492
493int trace_event_reg(struct trace_event_call *call,
494 enum trace_reg type, void *data)
495{
496 struct trace_event_file *file = data;
497
498 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
499 switch (type) {
500 case TRACE_REG_REGISTER:
501 return tracepoint_probe_register(call->tp,
502 call->class->probe,
503 file);
504 case TRACE_REG_UNREGISTER:
505 tracepoint_probe_unregister(call->tp,
506 call->class->probe,
507 file);
508 return 0;
509
510#ifdef CONFIG_PERF_EVENTS
511 case TRACE_REG_PERF_REGISTER:
512 return tracepoint_probe_register(call->tp,
513 call->class->perf_probe,
514 call);
515 case TRACE_REG_PERF_UNREGISTER:
516 tracepoint_probe_unregister(call->tp,
517 call->class->perf_probe,
518 call);
519 return 0;
520 case TRACE_REG_PERF_OPEN:
521 case TRACE_REG_PERF_CLOSE:
522 case TRACE_REG_PERF_ADD:
523 case TRACE_REG_PERF_DEL:
524 return 0;
525#endif
526 }
527 return 0;
528}
529EXPORT_SYMBOL_GPL(trace_event_reg);
530
531void trace_event_enable_cmd_record(bool enable)
532{
533 struct trace_event_file *file;
534 struct trace_array *tr;
535
536 lockdep_assert_held(&event_mutex);
537
538 do_for_each_event_file(tr, file) {
539
540 if (!(file->flags & EVENT_FILE_FL_ENABLED))
541 continue;
542
543 if (enable) {
544 tracing_start_cmdline_record();
545 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
546 } else {
547 tracing_stop_cmdline_record();
548 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
549 }
550 } while_for_each_event_file();
551}
552
553void trace_event_enable_tgid_record(bool enable)
554{
555 struct trace_event_file *file;
556 struct trace_array *tr;
557
558 lockdep_assert_held(&event_mutex);
559
560 do_for_each_event_file(tr, file) {
561 if (!(file->flags & EVENT_FILE_FL_ENABLED))
562 continue;
563
564 if (enable) {
565 tracing_start_tgid_record();
566 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
567 } else {
568 tracing_stop_tgid_record();
569 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
570 &file->flags);
571 }
572 } while_for_each_event_file();
573}
574
575static int __ftrace_event_enable_disable(struct trace_event_file *file,
576 int enable, int soft_disable)
577{
578 struct trace_event_call *call = file->event_call;
579 struct trace_array *tr = file->tr;
580 unsigned long file_flags = file->flags;
581 int ret = 0;
582 int disable;
583
584 switch (enable) {
585 case 0:
586 /*
587 * When soft_disable is set and enable is cleared, the sm_ref
588 * reference counter is decremented. If it reaches 0, we want
589 * to clear the SOFT_DISABLED flag but leave the event in the
590 * state that it was. That is, if the event was enabled and
591 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
592 * is set we do not want the event to be enabled before we
593 * clear the bit.
594 *
595 * When soft_disable is not set but the SOFT_MODE flag is,
596 * we do nothing. Do not disable the tracepoint, otherwise
597 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
598 */
599 if (soft_disable) {
600 if (atomic_dec_return(&file->sm_ref) > 0)
601 break;
602 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
603 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
604 } else
605 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
606
607 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
608 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
609 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
610 tracing_stop_cmdline_record();
611 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
612 }
613
614 if (file->flags & EVENT_FILE_FL_RECORDED_TGID) {
615 tracing_stop_tgid_record();
616 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
617 }
618
619 call->class->reg(call, TRACE_REG_UNREGISTER, file);
620 }
621 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
622 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
623 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
624 else
625 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
626 break;
627 case 1:
628 /*
629 * When soft_disable is set and enable is set, we want to
630 * register the tracepoint for the event, but leave the event
631 * as is. That means, if the event was already enabled, we do
632 * nothing (but set SOFT_MODE). If the event is disabled, we
633 * set SOFT_DISABLED before enabling the event tracepoint, so
634 * it still seems to be disabled.
635 */
636 if (!soft_disable)
637 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
638 else {
639 if (atomic_inc_return(&file->sm_ref) > 1)
640 break;
641 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
642 }
643
644 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
645 bool cmd = false, tgid = false;
646
647 /* Keep the event disabled, when going to SOFT_MODE. */
648 if (soft_disable)
649 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
650
651 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
652 cmd = true;
653 tracing_start_cmdline_record();
654 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
655 }
656
657 if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
658 tgid = true;
659 tracing_start_tgid_record();
660 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
661 }
662
663 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
664 if (ret) {
665 if (cmd)
666 tracing_stop_cmdline_record();
667 if (tgid)
668 tracing_stop_tgid_record();
669 pr_info("event trace: Could not enable event "
670 "%s\n", trace_event_name(call));
671 break;
672 }
673 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
674
675 /* WAS_ENABLED gets set but never cleared. */
676 set_bit(EVENT_FILE_FL_WAS_ENABLED_BIT, &file->flags);
677 }
678 break;
679 }
680
681 /* Enable or disable use of trace_buffered_event */
682 if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) !=
683 (file->flags & EVENT_FILE_FL_SOFT_DISABLED)) {
684 if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
685 trace_buffered_event_enable();
686 else
687 trace_buffered_event_disable();
688 }
689
690 return ret;
691}
692
693int trace_event_enable_disable(struct trace_event_file *file,
694 int enable, int soft_disable)
695{
696 return __ftrace_event_enable_disable(file, enable, soft_disable);
697}
698
699static int ftrace_event_enable_disable(struct trace_event_file *file,
700 int enable)
701{
702 return __ftrace_event_enable_disable(file, enable, 0);
703}
704
705static void ftrace_clear_events(struct trace_array *tr)
706{
707 struct trace_event_file *file;
708
709 mutex_lock(&event_mutex);
710 list_for_each_entry(file, &tr->events, list) {
711 ftrace_event_enable_disable(file, 0);
712 }
713 mutex_unlock(&event_mutex);
714}
715
716static void
717event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
718{
719 struct trace_pid_list *pid_list;
720 struct trace_array *tr = data;
721
722 pid_list = rcu_dereference_raw(tr->filtered_pids);
723 trace_filter_add_remove_task(pid_list, NULL, task);
724
725 pid_list = rcu_dereference_raw(tr->filtered_no_pids);
726 trace_filter_add_remove_task(pid_list, NULL, task);
727}
728
729static void
730event_filter_pid_sched_process_fork(void *data,
731 struct task_struct *self,
732 struct task_struct *task)
733{
734 struct trace_pid_list *pid_list;
735 struct trace_array *tr = data;
736
737 pid_list = rcu_dereference_sched(tr->filtered_pids);
738 trace_filter_add_remove_task(pid_list, self, task);
739
740 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
741 trace_filter_add_remove_task(pid_list, self, task);
742}
743
744void trace_event_follow_fork(struct trace_array *tr, bool enable)
745{
746 if (enable) {
747 register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
748 tr, INT_MIN);
749 register_trace_prio_sched_process_free(event_filter_pid_sched_process_exit,
750 tr, INT_MAX);
751 } else {
752 unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
753 tr);
754 unregister_trace_sched_process_free(event_filter_pid_sched_process_exit,
755 tr);
756 }
757}
758
759static void
760event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
761 struct task_struct *prev, struct task_struct *next)
762{
763 struct trace_array *tr = data;
764 struct trace_pid_list *no_pid_list;
765 struct trace_pid_list *pid_list;
766 bool ret;
767
768 pid_list = rcu_dereference_sched(tr->filtered_pids);
769 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
770
771 /*
772 * Sched switch is funny, as we only want to ignore it
773 * in the notrace case if both prev and next should be ignored.
774 */
775 ret = trace_ignore_this_task(NULL, no_pid_list, prev) &&
776 trace_ignore_this_task(NULL, no_pid_list, next);
777
778 this_cpu_write(tr->array_buffer.data->ignore_pid, ret ||
779 (trace_ignore_this_task(pid_list, NULL, prev) &&
780 trace_ignore_this_task(pid_list, NULL, next)));
781}
782
783static void
784event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
785 struct task_struct *prev, struct task_struct *next)
786{
787 struct trace_array *tr = data;
788 struct trace_pid_list *no_pid_list;
789 struct trace_pid_list *pid_list;
790
791 pid_list = rcu_dereference_sched(tr->filtered_pids);
792 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
793
794 this_cpu_write(tr->array_buffer.data->ignore_pid,
795 trace_ignore_this_task(pid_list, no_pid_list, next));
796}
797
798static void
799event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
800{
801 struct trace_array *tr = data;
802 struct trace_pid_list *no_pid_list;
803 struct trace_pid_list *pid_list;
804
805 /* Nothing to do if we are already tracing */
806 if (!this_cpu_read(tr->array_buffer.data->ignore_pid))
807 return;
808
809 pid_list = rcu_dereference_sched(tr->filtered_pids);
810 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
811
812 this_cpu_write(tr->array_buffer.data->ignore_pid,
813 trace_ignore_this_task(pid_list, no_pid_list, task));
814}
815
816static void
817event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
818{
819 struct trace_array *tr = data;
820 struct trace_pid_list *no_pid_list;
821 struct trace_pid_list *pid_list;
822
823 /* Nothing to do if we are not tracing */
824 if (this_cpu_read(tr->array_buffer.data->ignore_pid))
825 return;
826
827 pid_list = rcu_dereference_sched(tr->filtered_pids);
828 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
829
830 /* Set tracing if current is enabled */
831 this_cpu_write(tr->array_buffer.data->ignore_pid,
832 trace_ignore_this_task(pid_list, no_pid_list, current));
833}
834
835static void unregister_pid_events(struct trace_array *tr)
836{
837 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
838 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
839
840 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
841 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
842
843 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
844 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
845
846 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
847 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
848}
849
850static void __ftrace_clear_event_pids(struct trace_array *tr, int type)
851{
852 struct trace_pid_list *pid_list;
853 struct trace_pid_list *no_pid_list;
854 struct trace_event_file *file;
855 int cpu;
856
857 pid_list = rcu_dereference_protected(tr->filtered_pids,
858 lockdep_is_held(&event_mutex));
859 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
860 lockdep_is_held(&event_mutex));
861
862 /* Make sure there's something to do */
863 if (!pid_type_enabled(type, pid_list, no_pid_list))
864 return;
865
866 if (!still_need_pid_events(type, pid_list, no_pid_list)) {
867 unregister_pid_events(tr);
868
869 list_for_each_entry(file, &tr->events, list) {
870 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
871 }
872
873 for_each_possible_cpu(cpu)
874 per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false;
875 }
876
877 if (type & TRACE_PIDS)
878 rcu_assign_pointer(tr->filtered_pids, NULL);
879
880 if (type & TRACE_NO_PIDS)
881 rcu_assign_pointer(tr->filtered_no_pids, NULL);
882
883 /* Wait till all users are no longer using pid filtering */
884 tracepoint_synchronize_unregister();
885
886 if ((type & TRACE_PIDS) && pid_list)
887 trace_free_pid_list(pid_list);
888
889 if ((type & TRACE_NO_PIDS) && no_pid_list)
890 trace_free_pid_list(no_pid_list);
891}
892
893static void ftrace_clear_event_pids(struct trace_array *tr, int type)
894{
895 mutex_lock(&event_mutex);
896 __ftrace_clear_event_pids(tr, type);
897 mutex_unlock(&event_mutex);
898}
899
900static void __put_system(struct event_subsystem *system)
901{
902 struct event_filter *filter = system->filter;
903
904 WARN_ON_ONCE(system_refcount(system) == 0);
905 if (system_refcount_dec(system))
906 return;
907
908 list_del(&system->list);
909
910 if (filter) {
911 kfree(filter->filter_string);
912 kfree(filter);
913 }
914 kfree_const(system->name);
915 kfree(system);
916}
917
918static void __get_system(struct event_subsystem *system)
919{
920 WARN_ON_ONCE(system_refcount(system) == 0);
921 system_refcount_inc(system);
922}
923
924static void __get_system_dir(struct trace_subsystem_dir *dir)
925{
926 WARN_ON_ONCE(dir->ref_count == 0);
927 dir->ref_count++;
928 __get_system(dir->subsystem);
929}
930
931static void __put_system_dir(struct trace_subsystem_dir *dir)
932{
933 WARN_ON_ONCE(dir->ref_count == 0);
934 /* If the subsystem is about to be freed, the dir must be too */
935 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
936
937 __put_system(dir->subsystem);
938 if (!--dir->ref_count)
939 kfree(dir);
940}
941
942static void put_system(struct trace_subsystem_dir *dir)
943{
944 mutex_lock(&event_mutex);
945 __put_system_dir(dir);
946 mutex_unlock(&event_mutex);
947}
948
949static void remove_subsystem(struct trace_subsystem_dir *dir)
950{
951 if (!dir)
952 return;
953
954 if (!--dir->nr_events) {
955 tracefs_remove(dir->entry);
956 list_del(&dir->list);
957 __put_system_dir(dir);
958 }
959}
960
961static void remove_event_file_dir(struct trace_event_file *file)
962{
963 struct dentry *dir = file->dir;
964 struct dentry *child;
965
966 if (dir) {
967 spin_lock(&dir->d_lock); /* probably unneeded */
968 list_for_each_entry(child, &dir->d_subdirs, d_child) {
969 if (d_really_is_positive(child)) /* probably unneeded */
970 d_inode(child)->i_private = NULL;
971 }
972 spin_unlock(&dir->d_lock);
973
974 tracefs_remove(dir);
975 }
976
977 list_del(&file->list);
978 remove_subsystem(file->system);
979 free_event_filter(file->filter);
980 kmem_cache_free(file_cachep, file);
981}
982
983/*
984 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
985 */
986static int
987__ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
988 const char *sub, const char *event, int set)
989{
990 struct trace_event_file *file;
991 struct trace_event_call *call;
992 const char *name;
993 int ret = -EINVAL;
994 int eret = 0;
995
996 list_for_each_entry(file, &tr->events, list) {
997
998 call = file->event_call;
999 name = trace_event_name(call);
1000
1001 if (!name || !call->class || !call->class->reg)
1002 continue;
1003
1004 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1005 continue;
1006
1007 if (match &&
1008 strcmp(match, name) != 0 &&
1009 strcmp(match, call->class->system) != 0)
1010 continue;
1011
1012 if (sub && strcmp(sub, call->class->system) != 0)
1013 continue;
1014
1015 if (event && strcmp(event, name) != 0)
1016 continue;
1017
1018 ret = ftrace_event_enable_disable(file, set);
1019
1020 /*
1021 * Save the first error and return that. Some events
1022 * may still have been enabled, but let the user
1023 * know that something went wrong.
1024 */
1025 if (ret && !eret)
1026 eret = ret;
1027
1028 ret = eret;
1029 }
1030
1031 return ret;
1032}
1033
1034static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
1035 const char *sub, const char *event, int set)
1036{
1037 int ret;
1038
1039 mutex_lock(&event_mutex);
1040 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
1041 mutex_unlock(&event_mutex);
1042
1043 return ret;
1044}
1045
1046int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
1047{
1048 char *event = NULL, *sub = NULL, *match;
1049 int ret;
1050
1051 if (!tr)
1052 return -ENOENT;
1053 /*
1054 * The buf format can be <subsystem>:<event-name>
1055 * *:<event-name> means any event by that name.
1056 * :<event-name> is the same.
1057 *
1058 * <subsystem>:* means all events in that subsystem
1059 * <subsystem>: means the same.
1060 *
1061 * <name> (no ':') means all events in a subsystem with
1062 * the name <name> or any event that matches <name>
1063 */
1064
1065 match = strsep(&buf, ":");
1066 if (buf) {
1067 sub = match;
1068 event = buf;
1069 match = NULL;
1070
1071 if (!strlen(sub) || strcmp(sub, "*") == 0)
1072 sub = NULL;
1073 if (!strlen(event) || strcmp(event, "*") == 0)
1074 event = NULL;
1075 }
1076
1077 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
1078
1079 /* Put back the colon to allow this to be called again */
1080 if (buf)
1081 *(buf - 1) = ':';
1082
1083 return ret;
1084}
1085
1086/**
1087 * trace_set_clr_event - enable or disable an event
1088 * @system: system name to match (NULL for any system)
1089 * @event: event name to match (NULL for all events, within system)
1090 * @set: 1 to enable, 0 to disable
1091 *
1092 * This is a way for other parts of the kernel to enable or disable
1093 * event recording.
1094 *
1095 * Returns 0 on success, -EINVAL if the parameters do not match any
1096 * registered events.
1097 */
1098int trace_set_clr_event(const char *system, const char *event, int set)
1099{
1100 struct trace_array *tr = top_trace_array();
1101
1102 if (!tr)
1103 return -ENODEV;
1104
1105 return __ftrace_set_clr_event(tr, NULL, system, event, set);
1106}
1107EXPORT_SYMBOL_GPL(trace_set_clr_event);
1108
1109/**
1110 * trace_array_set_clr_event - enable or disable an event for a trace array.
1111 * @tr: concerned trace array.
1112 * @system: system name to match (NULL for any system)
1113 * @event: event name to match (NULL for all events, within system)
1114 * @enable: true to enable, false to disable
1115 *
1116 * This is a way for other parts of the kernel to enable or disable
1117 * event recording.
1118 *
1119 * Returns 0 on success, -EINVAL if the parameters do not match any
1120 * registered events.
1121 */
1122int trace_array_set_clr_event(struct trace_array *tr, const char *system,
1123 const char *event, bool enable)
1124{
1125 int set;
1126
1127 if (!tr)
1128 return -ENOENT;
1129
1130 set = (enable == true) ? 1 : 0;
1131 return __ftrace_set_clr_event(tr, NULL, system, event, set);
1132}
1133EXPORT_SYMBOL_GPL(trace_array_set_clr_event);
1134
1135/* 128 should be much more than enough */
1136#define EVENT_BUF_SIZE 127
1137
1138static ssize_t
1139ftrace_event_write(struct file *file, const char __user *ubuf,
1140 size_t cnt, loff_t *ppos)
1141{
1142 struct trace_parser parser;
1143 struct seq_file *m = file->private_data;
1144 struct trace_array *tr = m->private;
1145 ssize_t read, ret;
1146
1147 if (!cnt)
1148 return 0;
1149
1150 ret = tracing_update_buffers();
1151 if (ret < 0)
1152 return ret;
1153
1154 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
1155 return -ENOMEM;
1156
1157 read = trace_get_user(&parser, ubuf, cnt, ppos);
1158
1159 if (read >= 0 && trace_parser_loaded((&parser))) {
1160 int set = 1;
1161
1162 if (*parser.buffer == '!')
1163 set = 0;
1164
1165 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
1166 if (ret)
1167 goto out_put;
1168 }
1169
1170 ret = read;
1171
1172 out_put:
1173 trace_parser_put(&parser);
1174
1175 return ret;
1176}
1177
1178static void *
1179t_next(struct seq_file *m, void *v, loff_t *pos)
1180{
1181 struct trace_event_file *file = v;
1182 struct trace_event_call *call;
1183 struct trace_array *tr = m->private;
1184
1185 (*pos)++;
1186
1187 list_for_each_entry_continue(file, &tr->events, list) {
1188 call = file->event_call;
1189 /*
1190 * The ftrace subsystem is for showing formats only.
1191 * They can not be enabled or disabled via the event files.
1192 */
1193 if (call->class && call->class->reg &&
1194 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1195 return file;
1196 }
1197
1198 return NULL;
1199}
1200
1201static void *t_start(struct seq_file *m, loff_t *pos)
1202{
1203 struct trace_event_file *file;
1204 struct trace_array *tr = m->private;
1205 loff_t l;
1206
1207 mutex_lock(&event_mutex);
1208
1209 file = list_entry(&tr->events, struct trace_event_file, list);
1210 for (l = 0; l <= *pos; ) {
1211 file = t_next(m, file, &l);
1212 if (!file)
1213 break;
1214 }
1215 return file;
1216}
1217
1218static void *
1219s_next(struct seq_file *m, void *v, loff_t *pos)
1220{
1221 struct trace_event_file *file = v;
1222 struct trace_array *tr = m->private;
1223
1224 (*pos)++;
1225
1226 list_for_each_entry_continue(file, &tr->events, list) {
1227 if (file->flags & EVENT_FILE_FL_ENABLED)
1228 return file;
1229 }
1230
1231 return NULL;
1232}
1233
1234static void *s_start(struct seq_file *m, loff_t *pos)
1235{
1236 struct trace_event_file *file;
1237 struct trace_array *tr = m->private;
1238 loff_t l;
1239
1240 mutex_lock(&event_mutex);
1241
1242 file = list_entry(&tr->events, struct trace_event_file, list);
1243 for (l = 0; l <= *pos; ) {
1244 file = s_next(m, file, &l);
1245 if (!file)
1246 break;
1247 }
1248 return file;
1249}
1250
1251static int t_show(struct seq_file *m, void *v)
1252{
1253 struct trace_event_file *file = v;
1254 struct trace_event_call *call = file->event_call;
1255
1256 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1257 seq_printf(m, "%s:", call->class->system);
1258 seq_printf(m, "%s\n", trace_event_name(call));
1259
1260 return 0;
1261}
1262
1263static void t_stop(struct seq_file *m, void *p)
1264{
1265 mutex_unlock(&event_mutex);
1266}
1267
1268static void *
1269__next(struct seq_file *m, void *v, loff_t *pos, int type)
1270{
1271 struct trace_array *tr = m->private;
1272 struct trace_pid_list *pid_list;
1273
1274 if (type == TRACE_PIDS)
1275 pid_list = rcu_dereference_sched(tr->filtered_pids);
1276 else
1277 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1278
1279 return trace_pid_next(pid_list, v, pos);
1280}
1281
1282static void *
1283p_next(struct seq_file *m, void *v, loff_t *pos)
1284{
1285 return __next(m, v, pos, TRACE_PIDS);
1286}
1287
1288static void *
1289np_next(struct seq_file *m, void *v, loff_t *pos)
1290{
1291 return __next(m, v, pos, TRACE_NO_PIDS);
1292}
1293
1294static void *__start(struct seq_file *m, loff_t *pos, int type)
1295 __acquires(RCU)
1296{
1297 struct trace_pid_list *pid_list;
1298 struct trace_array *tr = m->private;
1299
1300 /*
1301 * Grab the mutex, to keep calls to p_next() having the same
1302 * tr->filtered_pids as p_start() has.
1303 * If we just passed the tr->filtered_pids around, then RCU would
1304 * have been enough, but doing that makes things more complex.
1305 */
1306 mutex_lock(&event_mutex);
1307 rcu_read_lock_sched();
1308
1309 if (type == TRACE_PIDS)
1310 pid_list = rcu_dereference_sched(tr->filtered_pids);
1311 else
1312 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1313
1314 if (!pid_list)
1315 return NULL;
1316
1317 return trace_pid_start(pid_list, pos);
1318}
1319
1320static void *p_start(struct seq_file *m, loff_t *pos)
1321 __acquires(RCU)
1322{
1323 return __start(m, pos, TRACE_PIDS);
1324}
1325
1326static void *np_start(struct seq_file *m, loff_t *pos)
1327 __acquires(RCU)
1328{
1329 return __start(m, pos, TRACE_NO_PIDS);
1330}
1331
1332static void p_stop(struct seq_file *m, void *p)
1333 __releases(RCU)
1334{
1335 rcu_read_unlock_sched();
1336 mutex_unlock(&event_mutex);
1337}
1338
1339static ssize_t
1340event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1341 loff_t *ppos)
1342{
1343 struct trace_event_file *file;
1344 unsigned long flags;
1345 char buf[4] = "0";
1346
1347 mutex_lock(&event_mutex);
1348 file = event_file_data(filp);
1349 if (likely(file))
1350 flags = file->flags;
1351 mutex_unlock(&event_mutex);
1352
1353 if (!file)
1354 return -ENODEV;
1355
1356 if (flags & EVENT_FILE_FL_ENABLED &&
1357 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1358 strcpy(buf, "1");
1359
1360 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1361 flags & EVENT_FILE_FL_SOFT_MODE)
1362 strcat(buf, "*");
1363
1364 strcat(buf, "\n");
1365
1366 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1367}
1368
1369static ssize_t
1370event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1371 loff_t *ppos)
1372{
1373 struct trace_event_file *file;
1374 unsigned long val;
1375 int ret;
1376
1377 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1378 if (ret)
1379 return ret;
1380
1381 ret = tracing_update_buffers();
1382 if (ret < 0)
1383 return ret;
1384
1385 switch (val) {
1386 case 0:
1387 case 1:
1388 ret = -ENODEV;
1389 mutex_lock(&event_mutex);
1390 file = event_file_data(filp);
1391 if (likely(file))
1392 ret = ftrace_event_enable_disable(file, val);
1393 mutex_unlock(&event_mutex);
1394 break;
1395
1396 default:
1397 return -EINVAL;
1398 }
1399
1400 *ppos += cnt;
1401
1402 return ret ? ret : cnt;
1403}
1404
1405static ssize_t
1406system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1407 loff_t *ppos)
1408{
1409 const char set_to_char[4] = { '?', '0', '1', 'X' };
1410 struct trace_subsystem_dir *dir = filp->private_data;
1411 struct event_subsystem *system = dir->subsystem;
1412 struct trace_event_call *call;
1413 struct trace_event_file *file;
1414 struct trace_array *tr = dir->tr;
1415 char buf[2];
1416 int set = 0;
1417 int ret;
1418
1419 mutex_lock(&event_mutex);
1420 list_for_each_entry(file, &tr->events, list) {
1421 call = file->event_call;
1422 if ((call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) ||
1423 !trace_event_name(call) || !call->class || !call->class->reg)
1424 continue;
1425
1426 if (system && strcmp(call->class->system, system->name) != 0)
1427 continue;
1428
1429 /*
1430 * We need to find out if all the events are set
1431 * or if all events or cleared, or if we have
1432 * a mixture.
1433 */
1434 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1435
1436 /*
1437 * If we have a mixture, no need to look further.
1438 */
1439 if (set == 3)
1440 break;
1441 }
1442 mutex_unlock(&event_mutex);
1443
1444 buf[0] = set_to_char[set];
1445 buf[1] = '\n';
1446
1447 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1448
1449 return ret;
1450}
1451
1452static ssize_t
1453system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1454 loff_t *ppos)
1455{
1456 struct trace_subsystem_dir *dir = filp->private_data;
1457 struct event_subsystem *system = dir->subsystem;
1458 const char *name = NULL;
1459 unsigned long val;
1460 ssize_t ret;
1461
1462 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1463 if (ret)
1464 return ret;
1465
1466 ret = tracing_update_buffers();
1467 if (ret < 0)
1468 return ret;
1469
1470 if (val != 0 && val != 1)
1471 return -EINVAL;
1472
1473 /*
1474 * Opening of "enable" adds a ref count to system,
1475 * so the name is safe to use.
1476 */
1477 if (system)
1478 name = system->name;
1479
1480 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1481 if (ret)
1482 goto out;
1483
1484 ret = cnt;
1485
1486out:
1487 *ppos += cnt;
1488
1489 return ret;
1490}
1491
1492enum {
1493 FORMAT_HEADER = 1,
1494 FORMAT_FIELD_SEPERATOR = 2,
1495 FORMAT_PRINTFMT = 3,
1496};
1497
1498static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1499{
1500 struct trace_event_call *call = event_file_data(m->private);
1501 struct list_head *common_head = &ftrace_common_fields;
1502 struct list_head *head = trace_get_fields(call);
1503 struct list_head *node = v;
1504
1505 (*pos)++;
1506
1507 switch ((unsigned long)v) {
1508 case FORMAT_HEADER:
1509 node = common_head;
1510 break;
1511
1512 case FORMAT_FIELD_SEPERATOR:
1513 node = head;
1514 break;
1515
1516 case FORMAT_PRINTFMT:
1517 /* all done */
1518 return NULL;
1519 }
1520
1521 node = node->prev;
1522 if (node == common_head)
1523 return (void *)FORMAT_FIELD_SEPERATOR;
1524 else if (node == head)
1525 return (void *)FORMAT_PRINTFMT;
1526 else
1527 return node;
1528}
1529
1530static int f_show(struct seq_file *m, void *v)
1531{
1532 struct trace_event_call *call = event_file_data(m->private);
1533 struct ftrace_event_field *field;
1534 const char *array_descriptor;
1535
1536 switch ((unsigned long)v) {
1537 case FORMAT_HEADER:
1538 seq_printf(m, "name: %s\n", trace_event_name(call));
1539 seq_printf(m, "ID: %d\n", call->event.type);
1540 seq_puts(m, "format:\n");
1541 return 0;
1542
1543 case FORMAT_FIELD_SEPERATOR:
1544 seq_putc(m, '\n');
1545 return 0;
1546
1547 case FORMAT_PRINTFMT:
1548 seq_printf(m, "\nprint fmt: %s\n",
1549 call->print_fmt);
1550 return 0;
1551 }
1552
1553 field = list_entry(v, struct ftrace_event_field, link);
1554 /*
1555 * Smartly shows the array type(except dynamic array).
1556 * Normal:
1557 * field:TYPE VAR
1558 * If TYPE := TYPE[LEN], it is shown:
1559 * field:TYPE VAR[LEN]
1560 */
1561 array_descriptor = strchr(field->type, '[');
1562
1563 if (str_has_prefix(field->type, "__data_loc"))
1564 array_descriptor = NULL;
1565
1566 if (!array_descriptor)
1567 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1568 field->type, field->name, field->offset,
1569 field->size, !!field->is_signed);
1570 else
1571 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1572 (int)(array_descriptor - field->type),
1573 field->type, field->name,
1574 array_descriptor, field->offset,
1575 field->size, !!field->is_signed);
1576
1577 return 0;
1578}
1579
1580static void *f_start(struct seq_file *m, loff_t *pos)
1581{
1582 void *p = (void *)FORMAT_HEADER;
1583 loff_t l = 0;
1584
1585 /* ->stop() is called even if ->start() fails */
1586 mutex_lock(&event_mutex);
1587 if (!event_file_data(m->private))
1588 return ERR_PTR(-ENODEV);
1589
1590 while (l < *pos && p)
1591 p = f_next(m, p, &l);
1592
1593 return p;
1594}
1595
1596static void f_stop(struct seq_file *m, void *p)
1597{
1598 mutex_unlock(&event_mutex);
1599}
1600
1601static const struct seq_operations trace_format_seq_ops = {
1602 .start = f_start,
1603 .next = f_next,
1604 .stop = f_stop,
1605 .show = f_show,
1606};
1607
1608static int trace_format_open(struct inode *inode, struct file *file)
1609{
1610 struct seq_file *m;
1611 int ret;
1612
1613 /* Do we want to hide event format files on tracefs lockdown? */
1614
1615 ret = seq_open(file, &trace_format_seq_ops);
1616 if (ret < 0)
1617 return ret;
1618
1619 m = file->private_data;
1620 m->private = file;
1621
1622 return 0;
1623}
1624
1625static ssize_t
1626event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1627{
1628 int id = (long)event_file_data(filp);
1629 char buf[32];
1630 int len;
1631
1632 if (unlikely(!id))
1633 return -ENODEV;
1634
1635 len = sprintf(buf, "%d\n", id);
1636
1637 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1638}
1639
1640static ssize_t
1641event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1642 loff_t *ppos)
1643{
1644 struct trace_event_file *file;
1645 struct trace_seq *s;
1646 int r = -ENODEV;
1647
1648 if (*ppos)
1649 return 0;
1650
1651 s = kmalloc(sizeof(*s), GFP_KERNEL);
1652
1653 if (!s)
1654 return -ENOMEM;
1655
1656 trace_seq_init(s);
1657
1658 mutex_lock(&event_mutex);
1659 file = event_file_data(filp);
1660 if (file)
1661 print_event_filter(file, s);
1662 mutex_unlock(&event_mutex);
1663
1664 if (file)
1665 r = simple_read_from_buffer(ubuf, cnt, ppos,
1666 s->buffer, trace_seq_used(s));
1667
1668 kfree(s);
1669
1670 return r;
1671}
1672
1673static ssize_t
1674event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1675 loff_t *ppos)
1676{
1677 struct trace_event_file *file;
1678 char *buf;
1679 int err = -ENODEV;
1680
1681 if (cnt >= PAGE_SIZE)
1682 return -EINVAL;
1683
1684 buf = memdup_user_nul(ubuf, cnt);
1685 if (IS_ERR(buf))
1686 return PTR_ERR(buf);
1687
1688 mutex_lock(&event_mutex);
1689 file = event_file_data(filp);
1690 if (file)
1691 err = apply_event_filter(file, buf);
1692 mutex_unlock(&event_mutex);
1693
1694 kfree(buf);
1695 if (err < 0)
1696 return err;
1697
1698 *ppos += cnt;
1699
1700 return cnt;
1701}
1702
1703static LIST_HEAD(event_subsystems);
1704
1705static int subsystem_open(struct inode *inode, struct file *filp)
1706{
1707 struct event_subsystem *system = NULL;
1708 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1709 struct trace_array *tr;
1710 int ret;
1711
1712 if (tracing_is_disabled())
1713 return -ENODEV;
1714
1715 /* Make sure the system still exists */
1716 mutex_lock(&event_mutex);
1717 mutex_lock(&trace_types_lock);
1718 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1719 list_for_each_entry(dir, &tr->systems, list) {
1720 if (dir == inode->i_private) {
1721 /* Don't open systems with no events */
1722 if (dir->nr_events) {
1723 __get_system_dir(dir);
1724 system = dir->subsystem;
1725 }
1726 goto exit_loop;
1727 }
1728 }
1729 }
1730 exit_loop:
1731 mutex_unlock(&trace_types_lock);
1732 mutex_unlock(&event_mutex);
1733
1734 if (!system)
1735 return -ENODEV;
1736
1737 /* Some versions of gcc think dir can be uninitialized here */
1738 WARN_ON(!dir);
1739
1740 /* Still need to increment the ref count of the system */
1741 if (trace_array_get(tr) < 0) {
1742 put_system(dir);
1743 return -ENODEV;
1744 }
1745
1746 ret = tracing_open_generic(inode, filp);
1747 if (ret < 0) {
1748 trace_array_put(tr);
1749 put_system(dir);
1750 }
1751
1752 return ret;
1753}
1754
1755static int system_tr_open(struct inode *inode, struct file *filp)
1756{
1757 struct trace_subsystem_dir *dir;
1758 struct trace_array *tr = inode->i_private;
1759 int ret;
1760
1761 /* Make a temporary dir that has no system but points to tr */
1762 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1763 if (!dir)
1764 return -ENOMEM;
1765
1766 ret = tracing_open_generic_tr(inode, filp);
1767 if (ret < 0) {
1768 kfree(dir);
1769 return ret;
1770 }
1771 dir->tr = tr;
1772 filp->private_data = dir;
1773
1774 return 0;
1775}
1776
1777static int subsystem_release(struct inode *inode, struct file *file)
1778{
1779 struct trace_subsystem_dir *dir = file->private_data;
1780
1781 trace_array_put(dir->tr);
1782
1783 /*
1784 * If dir->subsystem is NULL, then this is a temporary
1785 * descriptor that was made for a trace_array to enable
1786 * all subsystems.
1787 */
1788 if (dir->subsystem)
1789 put_system(dir);
1790 else
1791 kfree(dir);
1792
1793 return 0;
1794}
1795
1796static ssize_t
1797subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1798 loff_t *ppos)
1799{
1800 struct trace_subsystem_dir *dir = filp->private_data;
1801 struct event_subsystem *system = dir->subsystem;
1802 struct trace_seq *s;
1803 int r;
1804
1805 if (*ppos)
1806 return 0;
1807
1808 s = kmalloc(sizeof(*s), GFP_KERNEL);
1809 if (!s)
1810 return -ENOMEM;
1811
1812 trace_seq_init(s);
1813
1814 print_subsystem_event_filter(system, s);
1815 r = simple_read_from_buffer(ubuf, cnt, ppos,
1816 s->buffer, trace_seq_used(s));
1817
1818 kfree(s);
1819
1820 return r;
1821}
1822
1823static ssize_t
1824subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1825 loff_t *ppos)
1826{
1827 struct trace_subsystem_dir *dir = filp->private_data;
1828 char *buf;
1829 int err;
1830
1831 if (cnt >= PAGE_SIZE)
1832 return -EINVAL;
1833
1834 buf = memdup_user_nul(ubuf, cnt);
1835 if (IS_ERR(buf))
1836 return PTR_ERR(buf);
1837
1838 err = apply_subsystem_event_filter(dir, buf);
1839 kfree(buf);
1840 if (err < 0)
1841 return err;
1842
1843 *ppos += cnt;
1844
1845 return cnt;
1846}
1847
1848static ssize_t
1849show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1850{
1851 int (*func)(struct trace_seq *s) = filp->private_data;
1852 struct trace_seq *s;
1853 int r;
1854
1855 if (*ppos)
1856 return 0;
1857
1858 s = kmalloc(sizeof(*s), GFP_KERNEL);
1859 if (!s)
1860 return -ENOMEM;
1861
1862 trace_seq_init(s);
1863
1864 func(s);
1865 r = simple_read_from_buffer(ubuf, cnt, ppos,
1866 s->buffer, trace_seq_used(s));
1867
1868 kfree(s);
1869
1870 return r;
1871}
1872
1873static void ignore_task_cpu(void *data)
1874{
1875 struct trace_array *tr = data;
1876 struct trace_pid_list *pid_list;
1877 struct trace_pid_list *no_pid_list;
1878
1879 /*
1880 * This function is called by on_each_cpu() while the
1881 * event_mutex is held.
1882 */
1883 pid_list = rcu_dereference_protected(tr->filtered_pids,
1884 mutex_is_locked(&event_mutex));
1885 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
1886 mutex_is_locked(&event_mutex));
1887
1888 this_cpu_write(tr->array_buffer.data->ignore_pid,
1889 trace_ignore_this_task(pid_list, no_pid_list, current));
1890}
1891
1892static void register_pid_events(struct trace_array *tr)
1893{
1894 /*
1895 * Register a probe that is called before all other probes
1896 * to set ignore_pid if next or prev do not match.
1897 * Register a probe this is called after all other probes
1898 * to only keep ignore_pid set if next pid matches.
1899 */
1900 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1901 tr, INT_MAX);
1902 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1903 tr, 0);
1904
1905 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1906 tr, INT_MAX);
1907 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1908 tr, 0);
1909
1910 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1911 tr, INT_MAX);
1912 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1913 tr, 0);
1914
1915 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1916 tr, INT_MAX);
1917 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1918 tr, 0);
1919}
1920
1921static ssize_t
1922event_pid_write(struct file *filp, const char __user *ubuf,
1923 size_t cnt, loff_t *ppos, int type)
1924{
1925 struct seq_file *m = filp->private_data;
1926 struct trace_array *tr = m->private;
1927 struct trace_pid_list *filtered_pids = NULL;
1928 struct trace_pid_list *other_pids = NULL;
1929 struct trace_pid_list *pid_list;
1930 struct trace_event_file *file;
1931 ssize_t ret;
1932
1933 if (!cnt)
1934 return 0;
1935
1936 ret = tracing_update_buffers();
1937 if (ret < 0)
1938 return ret;
1939
1940 mutex_lock(&event_mutex);
1941
1942 if (type == TRACE_PIDS) {
1943 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1944 lockdep_is_held(&event_mutex));
1945 other_pids = rcu_dereference_protected(tr->filtered_no_pids,
1946 lockdep_is_held(&event_mutex));
1947 } else {
1948 filtered_pids = rcu_dereference_protected(tr->filtered_no_pids,
1949 lockdep_is_held(&event_mutex));
1950 other_pids = rcu_dereference_protected(tr->filtered_pids,
1951 lockdep_is_held(&event_mutex));
1952 }
1953
1954 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
1955 if (ret < 0)
1956 goto out;
1957
1958 if (type == TRACE_PIDS)
1959 rcu_assign_pointer(tr->filtered_pids, pid_list);
1960 else
1961 rcu_assign_pointer(tr->filtered_no_pids, pid_list);
1962
1963 list_for_each_entry(file, &tr->events, list) {
1964 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1965 }
1966
1967 if (filtered_pids) {
1968 tracepoint_synchronize_unregister();
1969 trace_free_pid_list(filtered_pids);
1970 } else if (pid_list && !other_pids) {
1971 register_pid_events(tr);
1972 }
1973
1974 /*
1975 * Ignoring of pids is done at task switch. But we have to
1976 * check for those tasks that are currently running.
1977 * Always do this in case a pid was appended or removed.
1978 */
1979 on_each_cpu(ignore_task_cpu, tr, 1);
1980
1981 out:
1982 mutex_unlock(&event_mutex);
1983
1984 if (ret > 0)
1985 *ppos += ret;
1986
1987 return ret;
1988}
1989
1990static ssize_t
1991ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1992 size_t cnt, loff_t *ppos)
1993{
1994 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
1995}
1996
1997static ssize_t
1998ftrace_event_npid_write(struct file *filp, const char __user *ubuf,
1999 size_t cnt, loff_t *ppos)
2000{
2001 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
2002}
2003
2004static int ftrace_event_avail_open(struct inode *inode, struct file *file);
2005static int ftrace_event_set_open(struct inode *inode, struct file *file);
2006static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
2007static int ftrace_event_set_npid_open(struct inode *inode, struct file *file);
2008static int ftrace_event_release(struct inode *inode, struct file *file);
2009
2010static const struct seq_operations show_event_seq_ops = {
2011 .start = t_start,
2012 .next = t_next,
2013 .show = t_show,
2014 .stop = t_stop,
2015};
2016
2017static const struct seq_operations show_set_event_seq_ops = {
2018 .start = s_start,
2019 .next = s_next,
2020 .show = t_show,
2021 .stop = t_stop,
2022};
2023
2024static const struct seq_operations show_set_pid_seq_ops = {
2025 .start = p_start,
2026 .next = p_next,
2027 .show = trace_pid_show,
2028 .stop = p_stop,
2029};
2030
2031static const struct seq_operations show_set_no_pid_seq_ops = {
2032 .start = np_start,
2033 .next = np_next,
2034 .show = trace_pid_show,
2035 .stop = p_stop,
2036};
2037
2038static const struct file_operations ftrace_avail_fops = {
2039 .open = ftrace_event_avail_open,
2040 .read = seq_read,
2041 .llseek = seq_lseek,
2042 .release = seq_release,
2043};
2044
2045static const struct file_operations ftrace_set_event_fops = {
2046 .open = ftrace_event_set_open,
2047 .read = seq_read,
2048 .write = ftrace_event_write,
2049 .llseek = seq_lseek,
2050 .release = ftrace_event_release,
2051};
2052
2053static const struct file_operations ftrace_set_event_pid_fops = {
2054 .open = ftrace_event_set_pid_open,
2055 .read = seq_read,
2056 .write = ftrace_event_pid_write,
2057 .llseek = seq_lseek,
2058 .release = ftrace_event_release,
2059};
2060
2061static const struct file_operations ftrace_set_event_notrace_pid_fops = {
2062 .open = ftrace_event_set_npid_open,
2063 .read = seq_read,
2064 .write = ftrace_event_npid_write,
2065 .llseek = seq_lseek,
2066 .release = ftrace_event_release,
2067};
2068
2069static const struct file_operations ftrace_enable_fops = {
2070 .open = tracing_open_generic,
2071 .read = event_enable_read,
2072 .write = event_enable_write,
2073 .llseek = default_llseek,
2074};
2075
2076static const struct file_operations ftrace_event_format_fops = {
2077 .open = trace_format_open,
2078 .read = seq_read,
2079 .llseek = seq_lseek,
2080 .release = seq_release,
2081};
2082
2083static const struct file_operations ftrace_event_id_fops = {
2084 .read = event_id_read,
2085 .llseek = default_llseek,
2086};
2087
2088static const struct file_operations ftrace_event_filter_fops = {
2089 .open = tracing_open_generic,
2090 .read = event_filter_read,
2091 .write = event_filter_write,
2092 .llseek = default_llseek,
2093};
2094
2095static const struct file_operations ftrace_subsystem_filter_fops = {
2096 .open = subsystem_open,
2097 .read = subsystem_filter_read,
2098 .write = subsystem_filter_write,
2099 .llseek = default_llseek,
2100 .release = subsystem_release,
2101};
2102
2103static const struct file_operations ftrace_system_enable_fops = {
2104 .open = subsystem_open,
2105 .read = system_enable_read,
2106 .write = system_enable_write,
2107 .llseek = default_llseek,
2108 .release = subsystem_release,
2109};
2110
2111static const struct file_operations ftrace_tr_enable_fops = {
2112 .open = system_tr_open,
2113 .read = system_enable_read,
2114 .write = system_enable_write,
2115 .llseek = default_llseek,
2116 .release = subsystem_release,
2117};
2118
2119static const struct file_operations ftrace_show_header_fops = {
2120 .open = tracing_open_generic,
2121 .read = show_header,
2122 .llseek = default_llseek,
2123};
2124
2125static int
2126ftrace_event_open(struct inode *inode, struct file *file,
2127 const struct seq_operations *seq_ops)
2128{
2129 struct seq_file *m;
2130 int ret;
2131
2132 ret = security_locked_down(LOCKDOWN_TRACEFS);
2133 if (ret)
2134 return ret;
2135
2136 ret = seq_open(file, seq_ops);
2137 if (ret < 0)
2138 return ret;
2139 m = file->private_data;
2140 /* copy tr over to seq ops */
2141 m->private = inode->i_private;
2142
2143 return ret;
2144}
2145
2146static int ftrace_event_release(struct inode *inode, struct file *file)
2147{
2148 struct trace_array *tr = inode->i_private;
2149
2150 trace_array_put(tr);
2151
2152 return seq_release(inode, file);
2153}
2154
2155static int
2156ftrace_event_avail_open(struct inode *inode, struct file *file)
2157{
2158 const struct seq_operations *seq_ops = &show_event_seq_ops;
2159
2160 /* Checks for tracefs lockdown */
2161 return ftrace_event_open(inode, file, seq_ops);
2162}
2163
2164static int
2165ftrace_event_set_open(struct inode *inode, struct file *file)
2166{
2167 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
2168 struct trace_array *tr = inode->i_private;
2169 int ret;
2170
2171 ret = tracing_check_open_get_tr(tr);
2172 if (ret)
2173 return ret;
2174
2175 if ((file->f_mode & FMODE_WRITE) &&
2176 (file->f_flags & O_TRUNC))
2177 ftrace_clear_events(tr);
2178
2179 ret = ftrace_event_open(inode, file, seq_ops);
2180 if (ret < 0)
2181 trace_array_put(tr);
2182 return ret;
2183}
2184
2185static int
2186ftrace_event_set_pid_open(struct inode *inode, struct file *file)
2187{
2188 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
2189 struct trace_array *tr = inode->i_private;
2190 int ret;
2191
2192 ret = tracing_check_open_get_tr(tr);
2193 if (ret)
2194 return ret;
2195
2196 if ((file->f_mode & FMODE_WRITE) &&
2197 (file->f_flags & O_TRUNC))
2198 ftrace_clear_event_pids(tr, TRACE_PIDS);
2199
2200 ret = ftrace_event_open(inode, file, seq_ops);
2201 if (ret < 0)
2202 trace_array_put(tr);
2203 return ret;
2204}
2205
2206static int
2207ftrace_event_set_npid_open(struct inode *inode, struct file *file)
2208{
2209 const struct seq_operations *seq_ops = &show_set_no_pid_seq_ops;
2210 struct trace_array *tr = inode->i_private;
2211 int ret;
2212
2213 ret = tracing_check_open_get_tr(tr);
2214 if (ret)
2215 return ret;
2216
2217 if ((file->f_mode & FMODE_WRITE) &&
2218 (file->f_flags & O_TRUNC))
2219 ftrace_clear_event_pids(tr, TRACE_NO_PIDS);
2220
2221 ret = ftrace_event_open(inode, file, seq_ops);
2222 if (ret < 0)
2223 trace_array_put(tr);
2224 return ret;
2225}
2226
2227static struct event_subsystem *
2228create_new_subsystem(const char *name)
2229{
2230 struct event_subsystem *system;
2231
2232 /* need to create new entry */
2233 system = kmalloc(sizeof(*system), GFP_KERNEL);
2234 if (!system)
2235 return NULL;
2236
2237 system->ref_count = 1;
2238
2239 /* Only allocate if dynamic (kprobes and modules) */
2240 system->name = kstrdup_const(name, GFP_KERNEL);
2241 if (!system->name)
2242 goto out_free;
2243
2244 system->filter = NULL;
2245
2246 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
2247 if (!system->filter)
2248 goto out_free;
2249
2250 list_add(&system->list, &event_subsystems);
2251
2252 return system;
2253
2254 out_free:
2255 kfree_const(system->name);
2256 kfree(system);
2257 return NULL;
2258}
2259
2260static struct dentry *
2261event_subsystem_dir(struct trace_array *tr, const char *name,
2262 struct trace_event_file *file, struct dentry *parent)
2263{
2264 struct trace_subsystem_dir *dir;
2265 struct event_subsystem *system;
2266 struct dentry *entry;
2267
2268 /* First see if we did not already create this dir */
2269 list_for_each_entry(dir, &tr->systems, list) {
2270 system = dir->subsystem;
2271 if (strcmp(system->name, name) == 0) {
2272 dir->nr_events++;
2273 file->system = dir;
2274 return dir->entry;
2275 }
2276 }
2277
2278 /* Now see if the system itself exists. */
2279 list_for_each_entry(system, &event_subsystems, list) {
2280 if (strcmp(system->name, name) == 0)
2281 break;
2282 }
2283 /* Reset system variable when not found */
2284 if (&system->list == &event_subsystems)
2285 system = NULL;
2286
2287 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
2288 if (!dir)
2289 goto out_fail;
2290
2291 if (!system) {
2292 system = create_new_subsystem(name);
2293 if (!system)
2294 goto out_free;
2295 } else
2296 __get_system(system);
2297
2298 dir->entry = tracefs_create_dir(name, parent);
2299 if (!dir->entry) {
2300 pr_warn("Failed to create system directory %s\n", name);
2301 __put_system(system);
2302 goto out_free;
2303 }
2304
2305 dir->tr = tr;
2306 dir->ref_count = 1;
2307 dir->nr_events = 1;
2308 dir->subsystem = system;
2309 file->system = dir;
2310
2311 /* the ftrace system is special, do not create enable or filter files */
2312 if (strcmp(name, "ftrace") != 0) {
2313
2314 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
2315 &ftrace_subsystem_filter_fops);
2316 if (!entry) {
2317 kfree(system->filter);
2318 system->filter = NULL;
2319 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
2320 }
2321
2322 trace_create_file("enable", 0644, dir->entry, dir,
2323 &ftrace_system_enable_fops);
2324 }
2325
2326 list_add(&dir->list, &tr->systems);
2327
2328 return dir->entry;
2329
2330 out_free:
2331 kfree(dir);
2332 out_fail:
2333 /* Only print this message if failed on memory allocation */
2334 if (!dir || !system)
2335 pr_warn("No memory to create event subsystem %s\n", name);
2336 return NULL;
2337}
2338
2339static int
2340event_define_fields(struct trace_event_call *call)
2341{
2342 struct list_head *head;
2343 int ret = 0;
2344
2345 /*
2346 * Other events may have the same class. Only update
2347 * the fields if they are not already defined.
2348 */
2349 head = trace_get_fields(call);
2350 if (list_empty(head)) {
2351 struct trace_event_fields *field = call->class->fields_array;
2352 unsigned int offset = sizeof(struct trace_entry);
2353
2354 for (; field->type; field++) {
2355 if (field->type == TRACE_FUNCTION_TYPE) {
2356 field->define_fields(call);
2357 break;
2358 }
2359
2360 offset = ALIGN(offset, field->align);
2361 ret = trace_define_field(call, field->type, field->name,
2362 offset, field->size,
2363 field->is_signed, field->filter_type);
2364 if (WARN_ON_ONCE(ret)) {
2365 pr_err("error code is %d\n", ret);
2366 break;
2367 }
2368
2369 offset += field->size;
2370 }
2371 }
2372
2373 return ret;
2374}
2375
2376static int
2377event_create_dir(struct dentry *parent, struct trace_event_file *file)
2378{
2379 struct trace_event_call *call = file->event_call;
2380 struct trace_array *tr = file->tr;
2381 struct dentry *d_events;
2382 const char *name;
2383 int ret;
2384
2385 /*
2386 * If the trace point header did not define TRACE_SYSTEM
2387 * then the system would be called "TRACE_SYSTEM".
2388 */
2389 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
2390 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
2391 if (!d_events)
2392 return -ENOMEM;
2393 } else
2394 d_events = parent;
2395
2396 name = trace_event_name(call);
2397 file->dir = tracefs_create_dir(name, d_events);
2398 if (!file->dir) {
2399 pr_warn("Could not create tracefs '%s' directory\n", name);
2400 return -1;
2401 }
2402
2403 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2404 trace_create_file("enable", 0644, file->dir, file,
2405 &ftrace_enable_fops);
2406
2407#ifdef CONFIG_PERF_EVENTS
2408 if (call->event.type && call->class->reg)
2409 trace_create_file("id", 0444, file->dir,
2410 (void *)(long)call->event.type,
2411 &ftrace_event_id_fops);
2412#endif
2413
2414 ret = event_define_fields(call);
2415 if (ret < 0) {
2416 pr_warn("Could not initialize trace point events/%s\n", name);
2417 return ret;
2418 }
2419
2420 /*
2421 * Only event directories that can be enabled should have
2422 * triggers or filters.
2423 */
2424 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
2425 trace_create_file("filter", 0644, file->dir, file,
2426 &ftrace_event_filter_fops);
2427
2428 trace_create_file("trigger", 0644, file->dir, file,
2429 &event_trigger_fops);
2430 }
2431
2432#ifdef CONFIG_HIST_TRIGGERS
2433 trace_create_file("hist", 0444, file->dir, file,
2434 &event_hist_fops);
2435#endif
2436#ifdef CONFIG_HIST_TRIGGERS_DEBUG
2437 trace_create_file("hist_debug", 0444, file->dir, file,
2438 &event_hist_debug_fops);
2439#endif
2440 trace_create_file("format", 0444, file->dir, call,
2441 &ftrace_event_format_fops);
2442
2443#ifdef CONFIG_TRACE_EVENT_INJECT
2444 if (call->event.type && call->class->reg)
2445 trace_create_file("inject", 0200, file->dir, file,
2446 &event_inject_fops);
2447#endif
2448
2449 return 0;
2450}
2451
2452static void remove_event_from_tracers(struct trace_event_call *call)
2453{
2454 struct trace_event_file *file;
2455 struct trace_array *tr;
2456
2457 do_for_each_event_file_safe(tr, file) {
2458 if (file->event_call != call)
2459 continue;
2460
2461 remove_event_file_dir(file);
2462 /*
2463 * The do_for_each_event_file_safe() is
2464 * a double loop. After finding the call for this
2465 * trace_array, we use break to jump to the next
2466 * trace_array.
2467 */
2468 break;
2469 } while_for_each_event_file();
2470}
2471
2472static void event_remove(struct trace_event_call *call)
2473{
2474 struct trace_array *tr;
2475 struct trace_event_file *file;
2476
2477 do_for_each_event_file(tr, file) {
2478 if (file->event_call != call)
2479 continue;
2480
2481 if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
2482 tr->clear_trace = true;
2483
2484 ftrace_event_enable_disable(file, 0);
2485 /*
2486 * The do_for_each_event_file() is
2487 * a double loop. After finding the call for this
2488 * trace_array, we use break to jump to the next
2489 * trace_array.
2490 */
2491 break;
2492 } while_for_each_event_file();
2493
2494 if (call->event.funcs)
2495 __unregister_trace_event(&call->event);
2496 remove_event_from_tracers(call);
2497 list_del(&call->list);
2498}
2499
2500static int event_init(struct trace_event_call *call)
2501{
2502 int ret = 0;
2503 const char *name;
2504
2505 name = trace_event_name(call);
2506 if (WARN_ON(!name))
2507 return -EINVAL;
2508
2509 if (call->class->raw_init) {
2510 ret = call->class->raw_init(call);
2511 if (ret < 0 && ret != -ENOSYS)
2512 pr_warn("Could not initialize trace events/%s\n", name);
2513 }
2514
2515 return ret;
2516}
2517
2518static int
2519__register_event(struct trace_event_call *call, struct module *mod)
2520{
2521 int ret;
2522
2523 ret = event_init(call);
2524 if (ret < 0)
2525 return ret;
2526
2527 list_add(&call->list, &ftrace_events);
2528 call->mod = mod;
2529
2530 return 0;
2531}
2532
2533static char *eval_replace(char *ptr, struct trace_eval_map *map, int len)
2534{
2535 int rlen;
2536 int elen;
2537
2538 /* Find the length of the eval value as a string */
2539 elen = snprintf(ptr, 0, "%ld", map->eval_value);
2540 /* Make sure there's enough room to replace the string with the value */
2541 if (len < elen)
2542 return NULL;
2543
2544 snprintf(ptr, elen + 1, "%ld", map->eval_value);
2545
2546 /* Get the rest of the string of ptr */
2547 rlen = strlen(ptr + len);
2548 memmove(ptr + elen, ptr + len, rlen);
2549 /* Make sure we end the new string */
2550 ptr[elen + rlen] = 0;
2551
2552 return ptr + elen;
2553}
2554
2555static void update_event_printk(struct trace_event_call *call,
2556 struct trace_eval_map *map)
2557{
2558 char *ptr;
2559 int quote = 0;
2560 int len = strlen(map->eval_string);
2561
2562 for (ptr = call->print_fmt; *ptr; ptr++) {
2563 if (*ptr == '\\') {
2564 ptr++;
2565 /* paranoid */
2566 if (!*ptr)
2567 break;
2568 continue;
2569 }
2570 if (*ptr == '"') {
2571 quote ^= 1;
2572 continue;
2573 }
2574 if (quote)
2575 continue;
2576 if (isdigit(*ptr)) {
2577 /* skip numbers */
2578 do {
2579 ptr++;
2580 /* Check for alpha chars like ULL */
2581 } while (isalnum(*ptr));
2582 if (!*ptr)
2583 break;
2584 /*
2585 * A number must have some kind of delimiter after
2586 * it, and we can ignore that too.
2587 */
2588 continue;
2589 }
2590 if (isalpha(*ptr) || *ptr == '_') {
2591 if (strncmp(map->eval_string, ptr, len) == 0 &&
2592 !isalnum(ptr[len]) && ptr[len] != '_') {
2593 ptr = eval_replace(ptr, map, len);
2594 /* enum/sizeof string smaller than value */
2595 if (WARN_ON_ONCE(!ptr))
2596 return;
2597 /*
2598 * No need to decrement here, as eval_replace()
2599 * returns the pointer to the character passed
2600 * the eval, and two evals can not be placed
2601 * back to back without something in between.
2602 * We can skip that something in between.
2603 */
2604 continue;
2605 }
2606 skip_more:
2607 do {
2608 ptr++;
2609 } while (isalnum(*ptr) || *ptr == '_');
2610 if (!*ptr)
2611 break;
2612 /*
2613 * If what comes after this variable is a '.' or
2614 * '->' then we can continue to ignore that string.
2615 */
2616 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2617 ptr += *ptr == '.' ? 1 : 2;
2618 if (!*ptr)
2619 break;
2620 goto skip_more;
2621 }
2622 /*
2623 * Once again, we can skip the delimiter that came
2624 * after the string.
2625 */
2626 continue;
2627 }
2628 }
2629}
2630
2631void trace_event_eval_update(struct trace_eval_map **map, int len)
2632{
2633 struct trace_event_call *call, *p;
2634 const char *last_system = NULL;
2635 bool first = false;
2636 int last_i;
2637 int i;
2638
2639 down_write(&trace_event_sem);
2640 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2641 /* events are usually grouped together with systems */
2642 if (!last_system || call->class->system != last_system) {
2643 first = true;
2644 last_i = 0;
2645 last_system = call->class->system;
2646 }
2647
2648 /*
2649 * Since calls are grouped by systems, the likelihood that the
2650 * next call in the iteration belongs to the same system as the
2651 * previous call is high. As an optimization, we skip searching
2652 * for a map[] that matches the call's system if the last call
2653 * was from the same system. That's what last_i is for. If the
2654 * call has the same system as the previous call, then last_i
2655 * will be the index of the first map[] that has a matching
2656 * system.
2657 */
2658 for (i = last_i; i < len; i++) {
2659 if (call->class->system == map[i]->system) {
2660 /* Save the first system if need be */
2661 if (first) {
2662 last_i = i;
2663 first = false;
2664 }
2665 update_event_printk(call, map[i]);
2666 }
2667 }
2668 }
2669 up_write(&trace_event_sem);
2670}
2671
2672static struct trace_event_file *
2673trace_create_new_event(struct trace_event_call *call,
2674 struct trace_array *tr)
2675{
2676 struct trace_event_file *file;
2677
2678 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2679 if (!file)
2680 return NULL;
2681
2682 file->event_call = call;
2683 file->tr = tr;
2684 atomic_set(&file->sm_ref, 0);
2685 atomic_set(&file->tm_ref, 0);
2686 INIT_LIST_HEAD(&file->triggers);
2687 list_add(&file->list, &tr->events);
2688
2689 return file;
2690}
2691
2692/* Add an event to a trace directory */
2693static int
2694__trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2695{
2696 struct trace_event_file *file;
2697
2698 file = trace_create_new_event(call, tr);
2699 if (!file)
2700 return -ENOMEM;
2701
2702 if (eventdir_initialized)
2703 return event_create_dir(tr->event_dir, file);
2704 else
2705 return event_define_fields(call);
2706}
2707
2708/*
2709 * Just create a descriptor for early init. A descriptor is required
2710 * for enabling events at boot. We want to enable events before
2711 * the filesystem is initialized.
2712 */
2713static int
2714__trace_early_add_new_event(struct trace_event_call *call,
2715 struct trace_array *tr)
2716{
2717 struct trace_event_file *file;
2718
2719 file = trace_create_new_event(call, tr);
2720 if (!file)
2721 return -ENOMEM;
2722
2723 return event_define_fields(call);
2724}
2725
2726struct ftrace_module_file_ops;
2727static void __add_event_to_tracers(struct trace_event_call *call);
2728
2729/* Add an additional event_call dynamically */
2730int trace_add_event_call(struct trace_event_call *call)
2731{
2732 int ret;
2733 lockdep_assert_held(&event_mutex);
2734
2735 mutex_lock(&trace_types_lock);
2736
2737 ret = __register_event(call, NULL);
2738 if (ret >= 0)
2739 __add_event_to_tracers(call);
2740
2741 mutex_unlock(&trace_types_lock);
2742 return ret;
2743}
2744
2745/*
2746 * Must be called under locking of trace_types_lock, event_mutex and
2747 * trace_event_sem.
2748 */
2749static void __trace_remove_event_call(struct trace_event_call *call)
2750{
2751 event_remove(call);
2752 trace_destroy_fields(call);
2753 free_event_filter(call->filter);
2754 call->filter = NULL;
2755}
2756
2757static int probe_remove_event_call(struct trace_event_call *call)
2758{
2759 struct trace_array *tr;
2760 struct trace_event_file *file;
2761
2762#ifdef CONFIG_PERF_EVENTS
2763 if (call->perf_refcount)
2764 return -EBUSY;
2765#endif
2766 do_for_each_event_file(tr, file) {
2767 if (file->event_call != call)
2768 continue;
2769 /*
2770 * We can't rely on ftrace_event_enable_disable(enable => 0)
2771 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2772 * TRACE_REG_UNREGISTER.
2773 */
2774 if (file->flags & EVENT_FILE_FL_ENABLED)
2775 return -EBUSY;
2776 /*
2777 * The do_for_each_event_file_safe() is
2778 * a double loop. After finding the call for this
2779 * trace_array, we use break to jump to the next
2780 * trace_array.
2781 */
2782 break;
2783 } while_for_each_event_file();
2784
2785 __trace_remove_event_call(call);
2786
2787 return 0;
2788}
2789
2790/* Remove an event_call */
2791int trace_remove_event_call(struct trace_event_call *call)
2792{
2793 int ret;
2794
2795 lockdep_assert_held(&event_mutex);
2796
2797 mutex_lock(&trace_types_lock);
2798 down_write(&trace_event_sem);
2799 ret = probe_remove_event_call(call);
2800 up_write(&trace_event_sem);
2801 mutex_unlock(&trace_types_lock);
2802
2803 return ret;
2804}
2805
2806#define for_each_event(event, start, end) \
2807 for (event = start; \
2808 (unsigned long)event < (unsigned long)end; \
2809 event++)
2810
2811#ifdef CONFIG_MODULES
2812
2813static void trace_module_add_events(struct module *mod)
2814{
2815 struct trace_event_call **call, **start, **end;
2816
2817 if (!mod->num_trace_events)
2818 return;
2819
2820 /* Don't add infrastructure for mods without tracepoints */
2821 if (trace_module_has_bad_taint(mod)) {
2822 pr_err("%s: module has bad taint, not creating trace events\n",
2823 mod->name);
2824 return;
2825 }
2826
2827 start = mod->trace_events;
2828 end = mod->trace_events + mod->num_trace_events;
2829
2830 for_each_event(call, start, end) {
2831 __register_event(*call, mod);
2832 __add_event_to_tracers(*call);
2833 }
2834}
2835
2836static void trace_module_remove_events(struct module *mod)
2837{
2838 struct trace_event_call *call, *p;
2839
2840 down_write(&trace_event_sem);
2841 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2842 if (call->mod == mod)
2843 __trace_remove_event_call(call);
2844 }
2845 up_write(&trace_event_sem);
2846
2847 /*
2848 * It is safest to reset the ring buffer if the module being unloaded
2849 * registered any events that were used. The only worry is if
2850 * a new module gets loaded, and takes on the same id as the events
2851 * of this module. When printing out the buffer, traced events left
2852 * over from this module may be passed to the new module events and
2853 * unexpected results may occur.
2854 */
2855 tracing_reset_all_online_cpus();
2856}
2857
2858static int trace_module_notify(struct notifier_block *self,
2859 unsigned long val, void *data)
2860{
2861 struct module *mod = data;
2862
2863 mutex_lock(&event_mutex);
2864 mutex_lock(&trace_types_lock);
2865 switch (val) {
2866 case MODULE_STATE_COMING:
2867 trace_module_add_events(mod);
2868 break;
2869 case MODULE_STATE_GOING:
2870 trace_module_remove_events(mod);
2871 break;
2872 }
2873 mutex_unlock(&trace_types_lock);
2874 mutex_unlock(&event_mutex);
2875
2876 return NOTIFY_OK;
2877}
2878
2879static struct notifier_block trace_module_nb = {
2880 .notifier_call = trace_module_notify,
2881 .priority = 1, /* higher than trace.c module notify */
2882};
2883#endif /* CONFIG_MODULES */
2884
2885/* Create a new event directory structure for a trace directory. */
2886static void
2887__trace_add_event_dirs(struct trace_array *tr)
2888{
2889 struct trace_event_call *call;
2890 int ret;
2891
2892 list_for_each_entry(call, &ftrace_events, list) {
2893 ret = __trace_add_new_event(call, tr);
2894 if (ret < 0)
2895 pr_warn("Could not create directory for event %s\n",
2896 trace_event_name(call));
2897 }
2898}
2899
2900/* Returns any file that matches the system and event */
2901struct trace_event_file *
2902__find_event_file(struct trace_array *tr, const char *system, const char *event)
2903{
2904 struct trace_event_file *file;
2905 struct trace_event_call *call;
2906 const char *name;
2907
2908 list_for_each_entry(file, &tr->events, list) {
2909
2910 call = file->event_call;
2911 name = trace_event_name(call);
2912
2913 if (!name || !call->class)
2914 continue;
2915
2916 if (strcmp(event, name) == 0 &&
2917 strcmp(system, call->class->system) == 0)
2918 return file;
2919 }
2920 return NULL;
2921}
2922
2923/* Returns valid trace event files that match system and event */
2924struct trace_event_file *
2925find_event_file(struct trace_array *tr, const char *system, const char *event)
2926{
2927 struct trace_event_file *file;
2928
2929 file = __find_event_file(tr, system, event);
2930 if (!file || !file->event_call->class->reg ||
2931 file->event_call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2932 return NULL;
2933
2934 return file;
2935}
2936
2937/**
2938 * trace_get_event_file - Find and return a trace event file
2939 * @instance: The name of the trace instance containing the event
2940 * @system: The name of the system containing the event
2941 * @event: The name of the event
2942 *
2943 * Return a trace event file given the trace instance name, trace
2944 * system, and trace event name. If the instance name is NULL, it
2945 * refers to the top-level trace array.
2946 *
2947 * This function will look it up and return it if found, after calling
2948 * trace_array_get() to prevent the instance from going away, and
2949 * increment the event's module refcount to prevent it from being
2950 * removed.
2951 *
2952 * To release the file, call trace_put_event_file(), which will call
2953 * trace_array_put() and decrement the event's module refcount.
2954 *
2955 * Return: The trace event on success, ERR_PTR otherwise.
2956 */
2957struct trace_event_file *trace_get_event_file(const char *instance,
2958 const char *system,
2959 const char *event)
2960{
2961 struct trace_array *tr = top_trace_array();
2962 struct trace_event_file *file = NULL;
2963 int ret = -EINVAL;
2964
2965 if (instance) {
2966 tr = trace_array_find_get(instance);
2967 if (!tr)
2968 return ERR_PTR(-ENOENT);
2969 } else {
2970 ret = trace_array_get(tr);
2971 if (ret)
2972 return ERR_PTR(ret);
2973 }
2974
2975 mutex_lock(&event_mutex);
2976
2977 file = find_event_file(tr, system, event);
2978 if (!file) {
2979 trace_array_put(tr);
2980 ret = -EINVAL;
2981 goto out;
2982 }
2983
2984 /* Don't let event modules unload while in use */
2985 ret = try_module_get(file->event_call->mod);
2986 if (!ret) {
2987 trace_array_put(tr);
2988 ret = -EBUSY;
2989 goto out;
2990 }
2991
2992 ret = 0;
2993 out:
2994 mutex_unlock(&event_mutex);
2995
2996 if (ret)
2997 file = ERR_PTR(ret);
2998
2999 return file;
3000}
3001EXPORT_SYMBOL_GPL(trace_get_event_file);
3002
3003/**
3004 * trace_put_event_file - Release a file from trace_get_event_file()
3005 * @file: The trace event file
3006 *
3007 * If a file was retrieved using trace_get_event_file(), this should
3008 * be called when it's no longer needed. It will cancel the previous
3009 * trace_array_get() called by that function, and decrement the
3010 * event's module refcount.
3011 */
3012void trace_put_event_file(struct trace_event_file *file)
3013{
3014 mutex_lock(&event_mutex);
3015 module_put(file->event_call->mod);
3016 mutex_unlock(&event_mutex);
3017
3018 trace_array_put(file->tr);
3019}
3020EXPORT_SYMBOL_GPL(trace_put_event_file);
3021
3022#ifdef CONFIG_DYNAMIC_FTRACE
3023
3024/* Avoid typos */
3025#define ENABLE_EVENT_STR "enable_event"
3026#define DISABLE_EVENT_STR "disable_event"
3027
3028struct event_probe_data {
3029 struct trace_event_file *file;
3030 unsigned long count;
3031 int ref;
3032 bool enable;
3033};
3034
3035static void update_event_probe(struct event_probe_data *data)
3036{
3037 if (data->enable)
3038 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
3039 else
3040 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
3041}
3042
3043static void
3044event_enable_probe(unsigned long ip, unsigned long parent_ip,
3045 struct trace_array *tr, struct ftrace_probe_ops *ops,
3046 void *data)
3047{
3048 struct ftrace_func_mapper *mapper = data;
3049 struct event_probe_data *edata;
3050 void **pdata;
3051
3052 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3053 if (!pdata || !*pdata)
3054 return;
3055
3056 edata = *pdata;
3057 update_event_probe(edata);
3058}
3059
3060static void
3061event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
3062 struct trace_array *tr, struct ftrace_probe_ops *ops,
3063 void *data)
3064{
3065 struct ftrace_func_mapper *mapper = data;
3066 struct event_probe_data *edata;
3067 void **pdata;
3068
3069 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3070 if (!pdata || !*pdata)
3071 return;
3072
3073 edata = *pdata;
3074
3075 if (!edata->count)
3076 return;
3077
3078 /* Skip if the event is in a state we want to switch to */
3079 if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
3080 return;
3081
3082 if (edata->count != -1)
3083 (edata->count)--;
3084
3085 update_event_probe(edata);
3086}
3087
3088static int
3089event_enable_print(struct seq_file *m, unsigned long ip,
3090 struct ftrace_probe_ops *ops, void *data)
3091{
3092 struct ftrace_func_mapper *mapper = data;
3093 struct event_probe_data *edata;
3094 void **pdata;
3095
3096 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3097
3098 if (WARN_ON_ONCE(!pdata || !*pdata))
3099 return 0;
3100
3101 edata = *pdata;
3102
3103 seq_printf(m, "%ps:", (void *)ip);
3104
3105 seq_printf(m, "%s:%s:%s",
3106 edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
3107 edata->file->event_call->class->system,
3108 trace_event_name(edata->file->event_call));
3109
3110 if (edata->count == -1)
3111 seq_puts(m, ":unlimited\n");
3112 else
3113 seq_printf(m, ":count=%ld\n", edata->count);
3114
3115 return 0;
3116}
3117
3118static int
3119event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
3120 unsigned long ip, void *init_data, void **data)
3121{
3122 struct ftrace_func_mapper *mapper = *data;
3123 struct event_probe_data *edata = init_data;
3124 int ret;
3125
3126 if (!mapper) {
3127 mapper = allocate_ftrace_func_mapper();
3128 if (!mapper)
3129 return -ENODEV;
3130 *data = mapper;
3131 }
3132
3133 ret = ftrace_func_mapper_add_ip(mapper, ip, edata);
3134 if (ret < 0)
3135 return ret;
3136
3137 edata->ref++;
3138
3139 return 0;
3140}
3141
3142static int free_probe_data(void *data)
3143{
3144 struct event_probe_data *edata = data;
3145
3146 edata->ref--;
3147 if (!edata->ref) {
3148 /* Remove the SOFT_MODE flag */
3149 __ftrace_event_enable_disable(edata->file, 0, 1);
3150 module_put(edata->file->event_call->mod);
3151 kfree(edata);
3152 }
3153 return 0;
3154}
3155
3156static void
3157event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
3158 unsigned long ip, void *data)
3159{
3160 struct ftrace_func_mapper *mapper = data;
3161 struct event_probe_data *edata;
3162
3163 if (!ip) {
3164 if (!mapper)
3165 return;
3166 free_ftrace_func_mapper(mapper, free_probe_data);
3167 return;
3168 }
3169
3170 edata = ftrace_func_mapper_remove_ip(mapper, ip);
3171
3172 if (WARN_ON_ONCE(!edata))
3173 return;
3174
3175 if (WARN_ON_ONCE(edata->ref <= 0))
3176 return;
3177
3178 free_probe_data(edata);
3179}
3180
3181static struct ftrace_probe_ops event_enable_probe_ops = {
3182 .func = event_enable_probe,
3183 .print = event_enable_print,
3184 .init = event_enable_init,
3185 .free = event_enable_free,
3186};
3187
3188static struct ftrace_probe_ops event_enable_count_probe_ops = {
3189 .func = event_enable_count_probe,
3190 .print = event_enable_print,
3191 .init = event_enable_init,
3192 .free = event_enable_free,
3193};
3194
3195static struct ftrace_probe_ops event_disable_probe_ops = {
3196 .func = event_enable_probe,
3197 .print = event_enable_print,
3198 .init = event_enable_init,
3199 .free = event_enable_free,
3200};
3201
3202static struct ftrace_probe_ops event_disable_count_probe_ops = {
3203 .func = event_enable_count_probe,
3204 .print = event_enable_print,
3205 .init = event_enable_init,
3206 .free = event_enable_free,
3207};
3208
3209static int
3210event_enable_func(struct trace_array *tr, struct ftrace_hash *hash,
3211 char *glob, char *cmd, char *param, int enabled)
3212{
3213 struct trace_event_file *file;
3214 struct ftrace_probe_ops *ops;
3215 struct event_probe_data *data;
3216 const char *system;
3217 const char *event;
3218 char *number;
3219 bool enable;
3220 int ret;
3221
3222 if (!tr)
3223 return -ENODEV;
3224
3225 /* hash funcs only work with set_ftrace_filter */
3226 if (!enabled || !param)
3227 return -EINVAL;
3228
3229 system = strsep(¶m, ":");
3230 if (!param)
3231 return -EINVAL;
3232
3233 event = strsep(¶m, ":");
3234
3235 mutex_lock(&event_mutex);
3236
3237 ret = -EINVAL;
3238 file = find_event_file(tr, system, event);
3239 if (!file)
3240 goto out;
3241
3242 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
3243
3244 if (enable)
3245 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
3246 else
3247 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
3248
3249 if (glob[0] == '!') {
3250 ret = unregister_ftrace_function_probe_func(glob+1, tr, ops);
3251 goto out;
3252 }
3253
3254 ret = -ENOMEM;
3255
3256 data = kzalloc(sizeof(*data), GFP_KERNEL);
3257 if (!data)
3258 goto out;
3259
3260 data->enable = enable;
3261 data->count = -1;
3262 data->file = file;
3263
3264 if (!param)
3265 goto out_reg;
3266
3267 number = strsep(¶m, ":");
3268
3269 ret = -EINVAL;
3270 if (!strlen(number))
3271 goto out_free;
3272
3273 /*
3274 * We use the callback data field (which is a pointer)
3275 * as our counter.
3276 */
3277 ret = kstrtoul(number, 0, &data->count);
3278 if (ret)
3279 goto out_free;
3280
3281 out_reg:
3282 /* Don't let event modules unload while probe registered */
3283 ret = try_module_get(file->event_call->mod);
3284 if (!ret) {
3285 ret = -EBUSY;
3286 goto out_free;
3287 }
3288
3289 ret = __ftrace_event_enable_disable(file, 1, 1);
3290 if (ret < 0)
3291 goto out_put;
3292
3293 ret = register_ftrace_function_probe(glob, tr, ops, data);
3294 /*
3295 * The above returns on success the # of functions enabled,
3296 * but if it didn't find any functions it returns zero.
3297 * Consider no functions a failure too.
3298 */
3299 if (!ret) {
3300 ret = -ENOENT;
3301 goto out_disable;
3302 } else if (ret < 0)
3303 goto out_disable;
3304 /* Just return zero, not the number of enabled functions */
3305 ret = 0;
3306 out:
3307 mutex_unlock(&event_mutex);
3308 return ret;
3309
3310 out_disable:
3311 __ftrace_event_enable_disable(file, 0, 1);
3312 out_put:
3313 module_put(file->event_call->mod);
3314 out_free:
3315 kfree(data);
3316 goto out;
3317}
3318
3319static struct ftrace_func_command event_enable_cmd = {
3320 .name = ENABLE_EVENT_STR,
3321 .func = event_enable_func,
3322};
3323
3324static struct ftrace_func_command event_disable_cmd = {
3325 .name = DISABLE_EVENT_STR,
3326 .func = event_enable_func,
3327};
3328
3329static __init int register_event_cmds(void)
3330{
3331 int ret;
3332
3333 ret = register_ftrace_command(&event_enable_cmd);
3334 if (WARN_ON(ret < 0))
3335 return ret;
3336 ret = register_ftrace_command(&event_disable_cmd);
3337 if (WARN_ON(ret < 0))
3338 unregister_ftrace_command(&event_enable_cmd);
3339 return ret;
3340}
3341#else
3342static inline int register_event_cmds(void) { return 0; }
3343#endif /* CONFIG_DYNAMIC_FTRACE */
3344
3345/*
3346 * The top level array and trace arrays created by boot-time tracing
3347 * have already had its trace_event_file descriptors created in order
3348 * to allow for early events to be recorded.
3349 * This function is called after the tracefs has been initialized,
3350 * and we now have to create the files associated to the events.
3351 */
3352static void __trace_early_add_event_dirs(struct trace_array *tr)
3353{
3354 struct trace_event_file *file;
3355 int ret;
3356
3357
3358 list_for_each_entry(file, &tr->events, list) {
3359 ret = event_create_dir(tr->event_dir, file);
3360 if (ret < 0)
3361 pr_warn("Could not create directory for event %s\n",
3362 trace_event_name(file->event_call));
3363 }
3364}
3365
3366/*
3367 * For early boot up, the top trace array and the trace arrays created
3368 * by boot-time tracing require to have a list of events that can be
3369 * enabled. This must be done before the filesystem is set up in order
3370 * to allow events to be traced early.
3371 */
3372void __trace_early_add_events(struct trace_array *tr)
3373{
3374 struct trace_event_call *call;
3375 int ret;
3376
3377 list_for_each_entry(call, &ftrace_events, list) {
3378 /* Early boot up should not have any modules loaded */
3379 if (WARN_ON_ONCE(call->mod))
3380 continue;
3381
3382 ret = __trace_early_add_new_event(call, tr);
3383 if (ret < 0)
3384 pr_warn("Could not create early event %s\n",
3385 trace_event_name(call));
3386 }
3387}
3388
3389/* Remove the event directory structure for a trace directory. */
3390static void
3391__trace_remove_event_dirs(struct trace_array *tr)
3392{
3393 struct trace_event_file *file, *next;
3394
3395 list_for_each_entry_safe(file, next, &tr->events, list)
3396 remove_event_file_dir(file);
3397}
3398
3399static void __add_event_to_tracers(struct trace_event_call *call)
3400{
3401 struct trace_array *tr;
3402
3403 list_for_each_entry(tr, &ftrace_trace_arrays, list)
3404 __trace_add_new_event(call, tr);
3405}
3406
3407extern struct trace_event_call *__start_ftrace_events[];
3408extern struct trace_event_call *__stop_ftrace_events[];
3409
3410static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
3411
3412static __init int setup_trace_event(char *str)
3413{
3414 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
3415 ring_buffer_expanded = true;
3416 disable_tracing_selftest("running event tracing");
3417
3418 return 1;
3419}
3420__setup("trace_event=", setup_trace_event);
3421
3422/* Expects to have event_mutex held when called */
3423static int
3424create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
3425{
3426 struct dentry *d_events;
3427 struct dentry *entry;
3428
3429 entry = tracefs_create_file("set_event", 0644, parent,
3430 tr, &ftrace_set_event_fops);
3431 if (!entry) {
3432 pr_warn("Could not create tracefs 'set_event' entry\n");
3433 return -ENOMEM;
3434 }
3435
3436 d_events = tracefs_create_dir("events", parent);
3437 if (!d_events) {
3438 pr_warn("Could not create tracefs 'events' directory\n");
3439 return -ENOMEM;
3440 }
3441
3442 entry = trace_create_file("enable", 0644, d_events,
3443 tr, &ftrace_tr_enable_fops);
3444 if (!entry) {
3445 pr_warn("Could not create tracefs 'enable' entry\n");
3446 return -ENOMEM;
3447 }
3448
3449 /* There are not as crucial, just warn if they are not created */
3450
3451 entry = tracefs_create_file("set_event_pid", 0644, parent,
3452 tr, &ftrace_set_event_pid_fops);
3453 if (!entry)
3454 pr_warn("Could not create tracefs 'set_event_pid' entry\n");
3455
3456 entry = tracefs_create_file("set_event_notrace_pid", 0644, parent,
3457 tr, &ftrace_set_event_notrace_pid_fops);
3458 if (!entry)
3459 pr_warn("Could not create tracefs 'set_event_notrace_pid' entry\n");
3460
3461 /* ring buffer internal formats */
3462 entry = trace_create_file("header_page", 0444, d_events,
3463 ring_buffer_print_page_header,
3464 &ftrace_show_header_fops);
3465 if (!entry)
3466 pr_warn("Could not create tracefs 'header_page' entry\n");
3467
3468 entry = trace_create_file("header_event", 0444, d_events,
3469 ring_buffer_print_entry_header,
3470 &ftrace_show_header_fops);
3471 if (!entry)
3472 pr_warn("Could not create tracefs 'header_event' entry\n");
3473
3474 tr->event_dir = d_events;
3475
3476 return 0;
3477}
3478
3479/**
3480 * event_trace_add_tracer - add a instance of a trace_array to events
3481 * @parent: The parent dentry to place the files/directories for events in
3482 * @tr: The trace array associated with these events
3483 *
3484 * When a new instance is created, it needs to set up its events
3485 * directory, as well as other files associated with events. It also
3486 * creates the event hierarchy in the @parent/events directory.
3487 *
3488 * Returns 0 on success.
3489 *
3490 * Must be called with event_mutex held.
3491 */
3492int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
3493{
3494 int ret;
3495
3496 lockdep_assert_held(&event_mutex);
3497
3498 ret = create_event_toplevel_files(parent, tr);
3499 if (ret)
3500 goto out;
3501
3502 down_write(&trace_event_sem);
3503 /* If tr already has the event list, it is initialized in early boot. */
3504 if (unlikely(!list_empty(&tr->events)))
3505 __trace_early_add_event_dirs(tr);
3506 else
3507 __trace_add_event_dirs(tr);
3508 up_write(&trace_event_sem);
3509
3510 out:
3511 return ret;
3512}
3513
3514/*
3515 * The top trace array already had its file descriptors created.
3516 * Now the files themselves need to be created.
3517 */
3518static __init int
3519early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
3520{
3521 int ret;
3522
3523 mutex_lock(&event_mutex);
3524
3525 ret = create_event_toplevel_files(parent, tr);
3526 if (ret)
3527 goto out_unlock;
3528
3529 down_write(&trace_event_sem);
3530 __trace_early_add_event_dirs(tr);
3531 up_write(&trace_event_sem);
3532
3533 out_unlock:
3534 mutex_unlock(&event_mutex);
3535
3536 return ret;
3537}
3538
3539/* Must be called with event_mutex held */
3540int event_trace_del_tracer(struct trace_array *tr)
3541{
3542 lockdep_assert_held(&event_mutex);
3543
3544 /* Disable any event triggers and associated soft-disabled events */
3545 clear_event_triggers(tr);
3546
3547 /* Clear the pid list */
3548 __ftrace_clear_event_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
3549
3550 /* Disable any running events */
3551 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3552
3553 /* Make sure no more events are being executed */
3554 tracepoint_synchronize_unregister();
3555
3556 down_write(&trace_event_sem);
3557 __trace_remove_event_dirs(tr);
3558 tracefs_remove(tr->event_dir);
3559 up_write(&trace_event_sem);
3560
3561 tr->event_dir = NULL;
3562
3563 return 0;
3564}
3565
3566static __init int event_trace_memsetup(void)
3567{
3568 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3569 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3570 return 0;
3571}
3572
3573static __init void
3574early_enable_events(struct trace_array *tr, bool disable_first)
3575{
3576 char *buf = bootup_event_buf;
3577 char *token;
3578 int ret;
3579
3580 while (true) {
3581 token = strsep(&buf, ",");
3582
3583 if (!token)
3584 break;
3585
3586 if (*token) {
3587 /* Restarting syscalls requires that we stop them first */
3588 if (disable_first)
3589 ftrace_set_clr_event(tr, token, 0);
3590
3591 ret = ftrace_set_clr_event(tr, token, 1);
3592 if (ret)
3593 pr_warn("Failed to enable trace event: %s\n", token);
3594 }
3595
3596 /* Put back the comma to allow this to be called again */
3597 if (buf)
3598 *(buf - 1) = ',';
3599 }
3600}
3601
3602static __init int event_trace_enable(void)
3603{
3604 struct trace_array *tr = top_trace_array();
3605 struct trace_event_call **iter, *call;
3606 int ret;
3607
3608 if (!tr)
3609 return -ENODEV;
3610
3611 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3612
3613 call = *iter;
3614 ret = event_init(call);
3615 if (!ret)
3616 list_add(&call->list, &ftrace_events);
3617 }
3618
3619 /*
3620 * We need the top trace array to have a working set of trace
3621 * points at early init, before the debug files and directories
3622 * are created. Create the file entries now, and attach them
3623 * to the actual file dentries later.
3624 */
3625 __trace_early_add_events(tr);
3626
3627 early_enable_events(tr, false);
3628
3629 trace_printk_start_comm();
3630
3631 register_event_cmds();
3632
3633 register_trigger_cmds();
3634
3635 return 0;
3636}
3637
3638/*
3639 * event_trace_enable() is called from trace_event_init() first to
3640 * initialize events and perhaps start any events that are on the
3641 * command line. Unfortunately, there are some events that will not
3642 * start this early, like the system call tracepoints that need
3643 * to set the %SYSCALL_WORK_SYSCALL_TRACEPOINT flag of pid 1. But
3644 * event_trace_enable() is called before pid 1 starts, and this flag
3645 * is never set, making the syscall tracepoint never get reached, but
3646 * the event is enabled regardless (and not doing anything).
3647 */
3648static __init int event_trace_enable_again(void)
3649{
3650 struct trace_array *tr;
3651
3652 tr = top_trace_array();
3653 if (!tr)
3654 return -ENODEV;
3655
3656 early_enable_events(tr, true);
3657
3658 return 0;
3659}
3660
3661early_initcall(event_trace_enable_again);
3662
3663/* Init fields which doesn't related to the tracefs */
3664static __init int event_trace_init_fields(void)
3665{
3666 if (trace_define_generic_fields())
3667 pr_warn("tracing: Failed to allocated generic fields");
3668
3669 if (trace_define_common_fields())
3670 pr_warn("tracing: Failed to allocate common fields");
3671
3672 return 0;
3673}
3674
3675__init int event_trace_init(void)
3676{
3677 struct trace_array *tr;
3678 struct dentry *entry;
3679 int ret;
3680
3681 tr = top_trace_array();
3682 if (!tr)
3683 return -ENODEV;
3684
3685 entry = tracefs_create_file("available_events", 0444, NULL,
3686 tr, &ftrace_avail_fops);
3687 if (!entry)
3688 pr_warn("Could not create tracefs 'available_events' entry\n");
3689
3690 ret = early_event_add_tracer(NULL, tr);
3691 if (ret)
3692 return ret;
3693
3694#ifdef CONFIG_MODULES
3695 ret = register_module_notifier(&trace_module_nb);
3696 if (ret)
3697 pr_warn("Failed to register trace events module notifier\n");
3698#endif
3699
3700 eventdir_initialized = true;
3701
3702 return 0;
3703}
3704
3705void __init trace_event_init(void)
3706{
3707 event_trace_memsetup();
3708 init_ftrace_syscalls();
3709 event_trace_enable();
3710 event_trace_init_fields();
3711}
3712
3713#ifdef CONFIG_EVENT_TRACE_STARTUP_TEST
3714
3715static DEFINE_SPINLOCK(test_spinlock);
3716static DEFINE_SPINLOCK(test_spinlock_irq);
3717static DEFINE_MUTEX(test_mutex);
3718
3719static __init void test_work(struct work_struct *dummy)
3720{
3721 spin_lock(&test_spinlock);
3722 spin_lock_irq(&test_spinlock_irq);
3723 udelay(1);
3724 spin_unlock_irq(&test_spinlock_irq);
3725 spin_unlock(&test_spinlock);
3726
3727 mutex_lock(&test_mutex);
3728 msleep(1);
3729 mutex_unlock(&test_mutex);
3730}
3731
3732static __init int event_test_thread(void *unused)
3733{
3734 void *test_malloc;
3735
3736 test_malloc = kmalloc(1234, GFP_KERNEL);
3737 if (!test_malloc)
3738 pr_info("failed to kmalloc\n");
3739
3740 schedule_on_each_cpu(test_work);
3741
3742 kfree(test_malloc);
3743
3744 set_current_state(TASK_INTERRUPTIBLE);
3745 while (!kthread_should_stop()) {
3746 schedule();
3747 set_current_state(TASK_INTERRUPTIBLE);
3748 }
3749 __set_current_state(TASK_RUNNING);
3750
3751 return 0;
3752}
3753
3754/*
3755 * Do various things that may trigger events.
3756 */
3757static __init void event_test_stuff(void)
3758{
3759 struct task_struct *test_thread;
3760
3761 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3762 msleep(1);
3763 kthread_stop(test_thread);
3764}
3765
3766/*
3767 * For every trace event defined, we will test each trace point separately,
3768 * and then by groups, and finally all trace points.
3769 */
3770static __init void event_trace_self_tests(void)
3771{
3772 struct trace_subsystem_dir *dir;
3773 struct trace_event_file *file;
3774 struct trace_event_call *call;
3775 struct event_subsystem *system;
3776 struct trace_array *tr;
3777 int ret;
3778
3779 tr = top_trace_array();
3780 if (!tr)
3781 return;
3782
3783 pr_info("Running tests on trace events:\n");
3784
3785 list_for_each_entry(file, &tr->events, list) {
3786
3787 call = file->event_call;
3788
3789 /* Only test those that have a probe */
3790 if (!call->class || !call->class->probe)
3791 continue;
3792
3793/*
3794 * Testing syscall events here is pretty useless, but
3795 * we still do it if configured. But this is time consuming.
3796 * What we really need is a user thread to perform the
3797 * syscalls as we test.
3798 */
3799#ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3800 if (call->class->system &&
3801 strcmp(call->class->system, "syscalls") == 0)
3802 continue;
3803#endif
3804
3805 pr_info("Testing event %s: ", trace_event_name(call));
3806
3807 /*
3808 * If an event is already enabled, someone is using
3809 * it and the self test should not be on.
3810 */
3811 if (file->flags & EVENT_FILE_FL_ENABLED) {
3812 pr_warn("Enabled event during self test!\n");
3813 WARN_ON_ONCE(1);
3814 continue;
3815 }
3816
3817 ftrace_event_enable_disable(file, 1);
3818 event_test_stuff();
3819 ftrace_event_enable_disable(file, 0);
3820
3821 pr_cont("OK\n");
3822 }
3823
3824 /* Now test at the sub system level */
3825
3826 pr_info("Running tests on trace event systems:\n");
3827
3828 list_for_each_entry(dir, &tr->systems, list) {
3829
3830 system = dir->subsystem;
3831
3832 /* the ftrace system is special, skip it */
3833 if (strcmp(system->name, "ftrace") == 0)
3834 continue;
3835
3836 pr_info("Testing event system %s: ", system->name);
3837
3838 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3839 if (WARN_ON_ONCE(ret)) {
3840 pr_warn("error enabling system %s\n",
3841 system->name);
3842 continue;
3843 }
3844
3845 event_test_stuff();
3846
3847 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3848 if (WARN_ON_ONCE(ret)) {
3849 pr_warn("error disabling system %s\n",
3850 system->name);
3851 continue;
3852 }
3853
3854 pr_cont("OK\n");
3855 }
3856
3857 /* Test with all events enabled */
3858
3859 pr_info("Running tests on all trace events:\n");
3860 pr_info("Testing all events: ");
3861
3862 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3863 if (WARN_ON_ONCE(ret)) {
3864 pr_warn("error enabling all events\n");
3865 return;
3866 }
3867
3868 event_test_stuff();
3869
3870 /* reset sysname */
3871 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3872 if (WARN_ON_ONCE(ret)) {
3873 pr_warn("error disabling all events\n");
3874 return;
3875 }
3876
3877 pr_cont("OK\n");
3878}
3879
3880#ifdef CONFIG_FUNCTION_TRACER
3881
3882static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3883
3884static struct trace_event_file event_trace_file __initdata;
3885
3886static void __init
3887function_test_events_call(unsigned long ip, unsigned long parent_ip,
3888 struct ftrace_ops *op, struct ftrace_regs *regs)
3889{
3890 struct trace_buffer *buffer;
3891 struct ring_buffer_event *event;
3892 struct ftrace_entry *entry;
3893 unsigned int trace_ctx;
3894 long disabled;
3895 int cpu;
3896
3897 trace_ctx = tracing_gen_ctx();
3898 preempt_disable_notrace();
3899 cpu = raw_smp_processor_id();
3900 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3901
3902 if (disabled != 1)
3903 goto out;
3904
3905 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
3906 TRACE_FN, sizeof(*entry),
3907 trace_ctx);
3908 if (!event)
3909 goto out;
3910 entry = ring_buffer_event_data(event);
3911 entry->ip = ip;
3912 entry->parent_ip = parent_ip;
3913
3914 event_trigger_unlock_commit(&event_trace_file, buffer, event,
3915 entry, trace_ctx);
3916 out:
3917 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3918 preempt_enable_notrace();
3919}
3920
3921static struct ftrace_ops trace_ops __initdata =
3922{
3923 .func = function_test_events_call,
3924};
3925
3926static __init void event_trace_self_test_with_function(void)
3927{
3928 int ret;
3929
3930 event_trace_file.tr = top_trace_array();
3931 if (WARN_ON(!event_trace_file.tr))
3932 return;
3933
3934 ret = register_ftrace_function(&trace_ops);
3935 if (WARN_ON(ret < 0)) {
3936 pr_info("Failed to enable function tracer for event tests\n");
3937 return;
3938 }
3939 pr_info("Running tests again, along with the function tracer\n");
3940 event_trace_self_tests();
3941 unregister_ftrace_function(&trace_ops);
3942}
3943#else
3944static __init void event_trace_self_test_with_function(void)
3945{
3946}
3947#endif
3948
3949static __init int event_trace_self_tests_init(void)
3950{
3951 if (!tracing_selftest_disabled) {
3952 event_trace_self_tests();
3953 event_trace_self_test_with_function();
3954 }
3955
3956 return 0;
3957}
3958
3959late_initcall(event_trace_self_tests_init);
3960
3961#endif