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