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