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