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