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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
43static LIST_HEAD(module_strings);
44
45struct module_string {
46 struct list_head next;
47 struct module *module;
48 char *str;
49};
50
51#define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
52
53static struct kmem_cache *field_cachep;
54static struct kmem_cache *file_cachep;
55
56static inline int system_refcount(struct event_subsystem *system)
57{
58 return system->ref_count;
59}
60
61static int system_refcount_inc(struct event_subsystem *system)
62{
63 return system->ref_count++;
64}
65
66static int system_refcount_dec(struct event_subsystem *system)
67{
68 return --system->ref_count;
69}
70
71/* Double loops, do not use break, only goto's work */
72#define do_for_each_event_file(tr, file) \
73 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
74 list_for_each_entry(file, &tr->events, list)
75
76#define do_for_each_event_file_safe(tr, file) \
77 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
78 struct trace_event_file *___n; \
79 list_for_each_entry_safe(file, ___n, &tr->events, list)
80
81#define while_for_each_event_file() \
82 }
83
84static struct ftrace_event_field *
85__find_event_field(struct list_head *head, char *name)
86{
87 struct ftrace_event_field *field;
88
89 list_for_each_entry(field, head, link) {
90 if (!strcmp(field->name, name))
91 return field;
92 }
93
94 return NULL;
95}
96
97struct ftrace_event_field *
98trace_find_event_field(struct trace_event_call *call, char *name)
99{
100 struct ftrace_event_field *field;
101 struct list_head *head;
102
103 head = trace_get_fields(call);
104 field = __find_event_field(head, name);
105 if (field)
106 return field;
107
108 field = __find_event_field(&ftrace_generic_fields, name);
109 if (field)
110 return field;
111
112 return __find_event_field(&ftrace_common_fields, name);
113}
114
115static int __trace_define_field(struct list_head *head, const char *type,
116 const char *name, int offset, int size,
117 int is_signed, int filter_type, int len)
118{
119 struct ftrace_event_field *field;
120
121 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
122 if (!field)
123 return -ENOMEM;
124
125 field->name = name;
126 field->type = type;
127
128 if (filter_type == FILTER_OTHER)
129 field->filter_type = filter_assign_type(type);
130 else
131 field->filter_type = filter_type;
132
133 field->offset = offset;
134 field->size = size;
135 field->is_signed = is_signed;
136 field->len = len;
137
138 list_add(&field->link, head);
139
140 return 0;
141}
142
143int trace_define_field(struct trace_event_call *call, const char *type,
144 const char *name, int offset, int size, int is_signed,
145 int filter_type)
146{
147 struct list_head *head;
148
149 if (WARN_ON(!call->class))
150 return 0;
151
152 head = trace_get_fields(call);
153 return __trace_define_field(head, type, name, offset, size,
154 is_signed, filter_type, 0);
155}
156EXPORT_SYMBOL_GPL(trace_define_field);
157
158static int trace_define_field_ext(struct trace_event_call *call, const char *type,
159 const char *name, int offset, int size, int is_signed,
160 int filter_type, int len)
161{
162 struct list_head *head;
163
164 if (WARN_ON(!call->class))
165 return 0;
166
167 head = trace_get_fields(call);
168 return __trace_define_field(head, type, name, offset, size,
169 is_signed, filter_type, len);
170}
171
172#define __generic_field(type, item, filter_type) \
173 ret = __trace_define_field(&ftrace_generic_fields, #type, \
174 #item, 0, 0, is_signed_type(type), \
175 filter_type, 0); \
176 if (ret) \
177 return ret;
178
179#define __common_field(type, item) \
180 ret = __trace_define_field(&ftrace_common_fields, #type, \
181 "common_" #item, \
182 offsetof(typeof(ent), item), \
183 sizeof(ent.item), \
184 is_signed_type(type), FILTER_OTHER, 0); \
185 if (ret) \
186 return ret;
187
188static int trace_define_generic_fields(void)
189{
190 int ret;
191
192 __generic_field(int, CPU, FILTER_CPU);
193 __generic_field(int, cpu, FILTER_CPU);
194 __generic_field(int, common_cpu, FILTER_CPU);
195 __generic_field(char *, COMM, FILTER_COMM);
196 __generic_field(char *, comm, FILTER_COMM);
197
198 return ret;
199}
200
201static int trace_define_common_fields(void)
202{
203 int ret;
204 struct trace_entry ent;
205
206 __common_field(unsigned short, type);
207 __common_field(unsigned char, flags);
208 /* Holds both preempt_count and migrate_disable */
209 __common_field(unsigned char, preempt_count);
210 __common_field(int, pid);
211
212 return ret;
213}
214
215static void trace_destroy_fields(struct trace_event_call *call)
216{
217 struct ftrace_event_field *field, *next;
218 struct list_head *head;
219
220 head = trace_get_fields(call);
221 list_for_each_entry_safe(field, next, head, link) {
222 list_del(&field->link);
223 kmem_cache_free(field_cachep, field);
224 }
225}
226
227/*
228 * run-time version of trace_event_get_offsets_<call>() that returns the last
229 * accessible offset of trace fields excluding __dynamic_array bytes
230 */
231int trace_event_get_offsets(struct trace_event_call *call)
232{
233 struct ftrace_event_field *tail;
234 struct list_head *head;
235
236 head = trace_get_fields(call);
237 /*
238 * head->next points to the last field with the largest offset,
239 * since it was added last by trace_define_field()
240 */
241 tail = list_first_entry(head, struct ftrace_event_field, link);
242 return tail->offset + tail->size;
243}
244
245/*
246 * Check if the referenced field is an array and return true,
247 * as arrays are OK to dereference.
248 */
249static bool test_field(const char *fmt, struct trace_event_call *call)
250{
251 struct trace_event_fields *field = call->class->fields_array;
252 const char *array_descriptor;
253 const char *p = fmt;
254 int len;
255
256 if (!(len = str_has_prefix(fmt, "REC->")))
257 return false;
258 fmt += len;
259 for (p = fmt; *p; p++) {
260 if (!isalnum(*p) && *p != '_')
261 break;
262 }
263 len = p - fmt;
264
265 for (; field->type; field++) {
266 if (strncmp(field->name, fmt, len) ||
267 field->name[len])
268 continue;
269 array_descriptor = strchr(field->type, '[');
270 /* This is an array and is OK to dereference. */
271 return array_descriptor != NULL;
272 }
273 return false;
274}
275
276/*
277 * Examine the print fmt of the event looking for unsafe dereference
278 * pointers using %p* that could be recorded in the trace event and
279 * much later referenced after the pointer was freed. Dereferencing
280 * pointers are OK, if it is dereferenced into the event itself.
281 */
282static void test_event_printk(struct trace_event_call *call)
283{
284 u64 dereference_flags = 0;
285 bool first = true;
286 const char *fmt, *c, *r, *a;
287 int parens = 0;
288 char in_quote = 0;
289 int start_arg = 0;
290 int arg = 0;
291 int i;
292
293 fmt = call->print_fmt;
294
295 if (!fmt)
296 return;
297
298 for (i = 0; fmt[i]; i++) {
299 switch (fmt[i]) {
300 case '\\':
301 i++;
302 if (!fmt[i])
303 return;
304 continue;
305 case '"':
306 case '\'':
307 /*
308 * The print fmt starts with a string that
309 * is processed first to find %p* usage,
310 * then after the first string, the print fmt
311 * contains arguments that are used to check
312 * if the dereferenced %p* usage is safe.
313 */
314 if (first) {
315 if (fmt[i] == '\'')
316 continue;
317 if (in_quote) {
318 arg = 0;
319 first = false;
320 /*
321 * If there was no %p* uses
322 * the fmt is OK.
323 */
324 if (!dereference_flags)
325 return;
326 }
327 }
328 if (in_quote) {
329 if (in_quote == fmt[i])
330 in_quote = 0;
331 } else {
332 in_quote = fmt[i];
333 }
334 continue;
335 case '%':
336 if (!first || !in_quote)
337 continue;
338 i++;
339 if (!fmt[i])
340 return;
341 switch (fmt[i]) {
342 case '%':
343 continue;
344 case 'p':
345 /* Find dereferencing fields */
346 switch (fmt[i + 1]) {
347 case 'B': case 'R': case 'r':
348 case 'b': case 'M': case 'm':
349 case 'I': case 'i': case 'E':
350 case 'U': case 'V': case 'N':
351 case 'a': case 'd': case 'D':
352 case 'g': case 't': case 'C':
353 case 'O': case 'f':
354 if (WARN_ONCE(arg == 63,
355 "Too many args for event: %s",
356 trace_event_name(call)))
357 return;
358 dereference_flags |= 1ULL << arg;
359 }
360 break;
361 default:
362 {
363 bool star = false;
364 int j;
365
366 /* Increment arg if %*s exists. */
367 for (j = 0; fmt[i + j]; j++) {
368 if (isdigit(fmt[i + j]) ||
369 fmt[i + j] == '.')
370 continue;
371 if (fmt[i + j] == '*') {
372 star = true;
373 continue;
374 }
375 if ((fmt[i + j] == 's') && star)
376 arg++;
377 break;
378 }
379 break;
380 } /* default */
381
382 } /* switch */
383 arg++;
384 continue;
385 case '(':
386 if (in_quote)
387 continue;
388 parens++;
389 continue;
390 case ')':
391 if (in_quote)
392 continue;
393 parens--;
394 if (WARN_ONCE(parens < 0,
395 "Paren mismatch for event: %s\narg='%s'\n%*s",
396 trace_event_name(call),
397 fmt + start_arg,
398 (i - start_arg) + 5, "^"))
399 return;
400 continue;
401 case ',':
402 if (in_quote || parens)
403 continue;
404 i++;
405 while (isspace(fmt[i]))
406 i++;
407 start_arg = i;
408 if (!(dereference_flags & (1ULL << arg)))
409 goto next_arg;
410
411 /* Find the REC-> in the argument */
412 c = strchr(fmt + i, ',');
413 r = strstr(fmt + i, "REC->");
414 if (r && (!c || r < c)) {
415 /*
416 * Addresses of events on the buffer,
417 * or an array on the buffer is
418 * OK to dereference.
419 * There's ways to fool this, but
420 * this is to catch common mistakes,
421 * not malicious code.
422 */
423 a = strchr(fmt + i, '&');
424 if ((a && (a < r)) || test_field(r, call))
425 dereference_flags &= ~(1ULL << arg);
426 } else if ((r = strstr(fmt + i, "__get_dynamic_array(")) &&
427 (!c || r < c)) {
428 dereference_flags &= ~(1ULL << arg);
429 } else if ((r = strstr(fmt + i, "__get_sockaddr(")) &&
430 (!c || r < c)) {
431 dereference_flags &= ~(1ULL << arg);
432 }
433
434 next_arg:
435 i--;
436 arg++;
437 }
438 }
439
440 /*
441 * If you triggered the below warning, the trace event reported
442 * uses an unsafe dereference pointer %p*. As the data stored
443 * at the trace event time may no longer exist when the trace
444 * event is printed, dereferencing to the original source is
445 * unsafe. The source of the dereference must be copied into the
446 * event itself, and the dereference must access the copy instead.
447 */
448 if (WARN_ON_ONCE(dereference_flags)) {
449 arg = 1;
450 while (!(dereference_flags & 1)) {
451 dereference_flags >>= 1;
452 arg++;
453 }
454 pr_warn("event %s has unsafe dereference of argument %d\n",
455 trace_event_name(call), arg);
456 pr_warn("print_fmt: %s\n", fmt);
457 }
458}
459
460int trace_event_raw_init(struct trace_event_call *call)
461{
462 int id;
463
464 id = register_trace_event(&call->event);
465 if (!id)
466 return -ENODEV;
467
468 test_event_printk(call);
469
470 return 0;
471}
472EXPORT_SYMBOL_GPL(trace_event_raw_init);
473
474bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
475{
476 struct trace_array *tr = trace_file->tr;
477 struct trace_array_cpu *data;
478 struct trace_pid_list *no_pid_list;
479 struct trace_pid_list *pid_list;
480
481 pid_list = rcu_dereference_raw(tr->filtered_pids);
482 no_pid_list = rcu_dereference_raw(tr->filtered_no_pids);
483
484 if (!pid_list && !no_pid_list)
485 return false;
486
487 data = this_cpu_ptr(tr->array_buffer.data);
488
489 return data->ignore_pid;
490}
491EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
492
493void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
494 struct trace_event_file *trace_file,
495 unsigned long len)
496{
497 struct trace_event_call *event_call = trace_file->event_call;
498
499 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
500 trace_event_ignore_this_pid(trace_file))
501 return NULL;
502
503 /*
504 * If CONFIG_PREEMPTION is enabled, then the tracepoint itself disables
505 * preemption (adding one to the preempt_count). Since we are
506 * interested in the preempt_count at the time the tracepoint was
507 * hit, we need to subtract one to offset the increment.
508 */
509 fbuffer->trace_ctx = tracing_gen_ctx_dec();
510 fbuffer->trace_file = trace_file;
511
512 fbuffer->event =
513 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
514 event_call->event.type, len,
515 fbuffer->trace_ctx);
516 if (!fbuffer->event)
517 return NULL;
518
519 fbuffer->regs = NULL;
520 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
521 return fbuffer->entry;
522}
523EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
524
525int trace_event_reg(struct trace_event_call *call,
526 enum trace_reg type, void *data)
527{
528 struct trace_event_file *file = data;
529
530 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
531 switch (type) {
532 case TRACE_REG_REGISTER:
533 return tracepoint_probe_register(call->tp,
534 call->class->probe,
535 file);
536 case TRACE_REG_UNREGISTER:
537 tracepoint_probe_unregister(call->tp,
538 call->class->probe,
539 file);
540 return 0;
541
542#ifdef CONFIG_PERF_EVENTS
543 case TRACE_REG_PERF_REGISTER:
544 return tracepoint_probe_register(call->tp,
545 call->class->perf_probe,
546 call);
547 case TRACE_REG_PERF_UNREGISTER:
548 tracepoint_probe_unregister(call->tp,
549 call->class->perf_probe,
550 call);
551 return 0;
552 case TRACE_REG_PERF_OPEN:
553 case TRACE_REG_PERF_CLOSE:
554 case TRACE_REG_PERF_ADD:
555 case TRACE_REG_PERF_DEL:
556 return 0;
557#endif
558 }
559 return 0;
560}
561EXPORT_SYMBOL_GPL(trace_event_reg);
562
563void trace_event_enable_cmd_record(bool enable)
564{
565 struct trace_event_file *file;
566 struct trace_array *tr;
567
568 lockdep_assert_held(&event_mutex);
569
570 do_for_each_event_file(tr, file) {
571
572 if (!(file->flags & EVENT_FILE_FL_ENABLED))
573 continue;
574
575 if (enable) {
576 tracing_start_cmdline_record();
577 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
578 } else {
579 tracing_stop_cmdline_record();
580 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
581 }
582 } while_for_each_event_file();
583}
584
585void trace_event_enable_tgid_record(bool enable)
586{
587 struct trace_event_file *file;
588 struct trace_array *tr;
589
590 lockdep_assert_held(&event_mutex);
591
592 do_for_each_event_file(tr, file) {
593 if (!(file->flags & EVENT_FILE_FL_ENABLED))
594 continue;
595
596 if (enable) {
597 tracing_start_tgid_record();
598 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
599 } else {
600 tracing_stop_tgid_record();
601 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
602 &file->flags);
603 }
604 } while_for_each_event_file();
605}
606
607static int __ftrace_event_enable_disable(struct trace_event_file *file,
608 int enable, int soft_disable)
609{
610 struct trace_event_call *call = file->event_call;
611 struct trace_array *tr = file->tr;
612 unsigned long file_flags = file->flags;
613 int ret = 0;
614 int disable;
615
616 switch (enable) {
617 case 0:
618 /*
619 * When soft_disable is set and enable is cleared, the sm_ref
620 * reference counter is decremented. If it reaches 0, we want
621 * to clear the SOFT_DISABLED flag but leave the event in the
622 * state that it was. That is, if the event was enabled and
623 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
624 * is set we do not want the event to be enabled before we
625 * clear the bit.
626 *
627 * When soft_disable is not set but the SOFT_MODE flag is,
628 * we do nothing. Do not disable the tracepoint, otherwise
629 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
630 */
631 if (soft_disable) {
632 if (atomic_dec_return(&file->sm_ref) > 0)
633 break;
634 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
635 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
636 } else
637 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
638
639 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
640 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
641 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
642 tracing_stop_cmdline_record();
643 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
644 }
645
646 if (file->flags & EVENT_FILE_FL_RECORDED_TGID) {
647 tracing_stop_tgid_record();
648 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
649 }
650
651 call->class->reg(call, TRACE_REG_UNREGISTER, file);
652 }
653 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
654 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
655 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
656 else
657 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
658 break;
659 case 1:
660 /*
661 * When soft_disable is set and enable is set, we want to
662 * register the tracepoint for the event, but leave the event
663 * as is. That means, if the event was already enabled, we do
664 * nothing (but set SOFT_MODE). If the event is disabled, we
665 * set SOFT_DISABLED before enabling the event tracepoint, so
666 * it still seems to be disabled.
667 */
668 if (!soft_disable)
669 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
670 else {
671 if (atomic_inc_return(&file->sm_ref) > 1)
672 break;
673 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
674 }
675
676 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
677 bool cmd = false, tgid = false;
678
679 /* Keep the event disabled, when going to SOFT_MODE. */
680 if (soft_disable)
681 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
682
683 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
684 cmd = true;
685 tracing_start_cmdline_record();
686 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
687 }
688
689 if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
690 tgid = true;
691 tracing_start_tgid_record();
692 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
693 }
694
695 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
696 if (ret) {
697 if (cmd)
698 tracing_stop_cmdline_record();
699 if (tgid)
700 tracing_stop_tgid_record();
701 pr_info("event trace: Could not enable event "
702 "%s\n", trace_event_name(call));
703 break;
704 }
705 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
706
707 /* WAS_ENABLED gets set but never cleared. */
708 set_bit(EVENT_FILE_FL_WAS_ENABLED_BIT, &file->flags);
709 }
710 break;
711 }
712
713 /* Enable or disable use of trace_buffered_event */
714 if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) !=
715 (file->flags & EVENT_FILE_FL_SOFT_DISABLED)) {
716 if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
717 trace_buffered_event_enable();
718 else
719 trace_buffered_event_disable();
720 }
721
722 return ret;
723}
724
725int trace_event_enable_disable(struct trace_event_file *file,
726 int enable, int soft_disable)
727{
728 return __ftrace_event_enable_disable(file, enable, soft_disable);
729}
730
731static int ftrace_event_enable_disable(struct trace_event_file *file,
732 int enable)
733{
734 return __ftrace_event_enable_disable(file, enable, 0);
735}
736
737static void ftrace_clear_events(struct trace_array *tr)
738{
739 struct trace_event_file *file;
740
741 mutex_lock(&event_mutex);
742 list_for_each_entry(file, &tr->events, list) {
743 ftrace_event_enable_disable(file, 0);
744 }
745 mutex_unlock(&event_mutex);
746}
747
748static void
749event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
750{
751 struct trace_pid_list *pid_list;
752 struct trace_array *tr = data;
753
754 pid_list = rcu_dereference_raw(tr->filtered_pids);
755 trace_filter_add_remove_task(pid_list, NULL, task);
756
757 pid_list = rcu_dereference_raw(tr->filtered_no_pids);
758 trace_filter_add_remove_task(pid_list, NULL, task);
759}
760
761static void
762event_filter_pid_sched_process_fork(void *data,
763 struct task_struct *self,
764 struct task_struct *task)
765{
766 struct trace_pid_list *pid_list;
767 struct trace_array *tr = data;
768
769 pid_list = rcu_dereference_sched(tr->filtered_pids);
770 trace_filter_add_remove_task(pid_list, self, task);
771
772 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
773 trace_filter_add_remove_task(pid_list, self, task);
774}
775
776void trace_event_follow_fork(struct trace_array *tr, bool enable)
777{
778 if (enable) {
779 register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
780 tr, INT_MIN);
781 register_trace_prio_sched_process_free(event_filter_pid_sched_process_exit,
782 tr, INT_MAX);
783 } else {
784 unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
785 tr);
786 unregister_trace_sched_process_free(event_filter_pid_sched_process_exit,
787 tr);
788 }
789}
790
791static void
792event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
793 struct task_struct *prev,
794 struct task_struct *next,
795 unsigned int prev_state)
796{
797 struct trace_array *tr = data;
798 struct trace_pid_list *no_pid_list;
799 struct trace_pid_list *pid_list;
800 bool ret;
801
802 pid_list = rcu_dereference_sched(tr->filtered_pids);
803 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
804
805 /*
806 * Sched switch is funny, as we only want to ignore it
807 * in the notrace case if both prev and next should be ignored.
808 */
809 ret = trace_ignore_this_task(NULL, no_pid_list, prev) &&
810 trace_ignore_this_task(NULL, no_pid_list, next);
811
812 this_cpu_write(tr->array_buffer.data->ignore_pid, ret ||
813 (trace_ignore_this_task(pid_list, NULL, prev) &&
814 trace_ignore_this_task(pid_list, NULL, next)));
815}
816
817static void
818event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
819 struct task_struct *prev,
820 struct task_struct *next,
821 unsigned int prev_state)
822{
823 struct trace_array *tr = data;
824 struct trace_pid_list *no_pid_list;
825 struct trace_pid_list *pid_list;
826
827 pid_list = rcu_dereference_sched(tr->filtered_pids);
828 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
829
830 this_cpu_write(tr->array_buffer.data->ignore_pid,
831 trace_ignore_this_task(pid_list, no_pid_list, next));
832}
833
834static void
835event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
836{
837 struct trace_array *tr = data;
838 struct trace_pid_list *no_pid_list;
839 struct trace_pid_list *pid_list;
840
841 /* Nothing to do if we are already tracing */
842 if (!this_cpu_read(tr->array_buffer.data->ignore_pid))
843 return;
844
845 pid_list = rcu_dereference_sched(tr->filtered_pids);
846 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
847
848 this_cpu_write(tr->array_buffer.data->ignore_pid,
849 trace_ignore_this_task(pid_list, no_pid_list, task));
850}
851
852static void
853event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
854{
855 struct trace_array *tr = data;
856 struct trace_pid_list *no_pid_list;
857 struct trace_pid_list *pid_list;
858
859 /* Nothing to do if we are not tracing */
860 if (this_cpu_read(tr->array_buffer.data->ignore_pid))
861 return;
862
863 pid_list = rcu_dereference_sched(tr->filtered_pids);
864 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
865
866 /* Set tracing if current is enabled */
867 this_cpu_write(tr->array_buffer.data->ignore_pid,
868 trace_ignore_this_task(pid_list, no_pid_list, current));
869}
870
871static void unregister_pid_events(struct trace_array *tr)
872{
873 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
874 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
875
876 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
877 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
878
879 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
880 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
881
882 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
883 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
884}
885
886static void __ftrace_clear_event_pids(struct trace_array *tr, int type)
887{
888 struct trace_pid_list *pid_list;
889 struct trace_pid_list *no_pid_list;
890 struct trace_event_file *file;
891 int cpu;
892
893 pid_list = rcu_dereference_protected(tr->filtered_pids,
894 lockdep_is_held(&event_mutex));
895 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
896 lockdep_is_held(&event_mutex));
897
898 /* Make sure there's something to do */
899 if (!pid_type_enabled(type, pid_list, no_pid_list))
900 return;
901
902 if (!still_need_pid_events(type, pid_list, no_pid_list)) {
903 unregister_pid_events(tr);
904
905 list_for_each_entry(file, &tr->events, list) {
906 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
907 }
908
909 for_each_possible_cpu(cpu)
910 per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false;
911 }
912
913 if (type & TRACE_PIDS)
914 rcu_assign_pointer(tr->filtered_pids, NULL);
915
916 if (type & TRACE_NO_PIDS)
917 rcu_assign_pointer(tr->filtered_no_pids, NULL);
918
919 /* Wait till all users are no longer using pid filtering */
920 tracepoint_synchronize_unregister();
921
922 if ((type & TRACE_PIDS) && pid_list)
923 trace_pid_list_free(pid_list);
924
925 if ((type & TRACE_NO_PIDS) && no_pid_list)
926 trace_pid_list_free(no_pid_list);
927}
928
929static void ftrace_clear_event_pids(struct trace_array *tr, int type)
930{
931 mutex_lock(&event_mutex);
932 __ftrace_clear_event_pids(tr, type);
933 mutex_unlock(&event_mutex);
934}
935
936static void __put_system(struct event_subsystem *system)
937{
938 struct event_filter *filter = system->filter;
939
940 WARN_ON_ONCE(system_refcount(system) == 0);
941 if (system_refcount_dec(system))
942 return;
943
944 list_del(&system->list);
945
946 if (filter) {
947 kfree(filter->filter_string);
948 kfree(filter);
949 }
950 kfree_const(system->name);
951 kfree(system);
952}
953
954static void __get_system(struct event_subsystem *system)
955{
956 WARN_ON_ONCE(system_refcount(system) == 0);
957 system_refcount_inc(system);
958}
959
960static void __get_system_dir(struct trace_subsystem_dir *dir)
961{
962 WARN_ON_ONCE(dir->ref_count == 0);
963 dir->ref_count++;
964 __get_system(dir->subsystem);
965}
966
967static void __put_system_dir(struct trace_subsystem_dir *dir)
968{
969 WARN_ON_ONCE(dir->ref_count == 0);
970 /* If the subsystem is about to be freed, the dir must be too */
971 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
972
973 __put_system(dir->subsystem);
974 if (!--dir->ref_count)
975 kfree(dir);
976}
977
978static void put_system(struct trace_subsystem_dir *dir)
979{
980 mutex_lock(&event_mutex);
981 __put_system_dir(dir);
982 mutex_unlock(&event_mutex);
983}
984
985static void remove_subsystem(struct trace_subsystem_dir *dir)
986{
987 if (!dir)
988 return;
989
990 if (!--dir->nr_events) {
991 tracefs_remove(dir->entry);
992 list_del(&dir->list);
993 __put_system_dir(dir);
994 }
995}
996
997static void remove_event_file_dir(struct trace_event_file *file)
998{
999 struct dentry *dir = file->dir;
1000 struct dentry *child;
1001
1002 if (dir) {
1003 spin_lock(&dir->d_lock); /* probably unneeded */
1004 list_for_each_entry(child, &dir->d_subdirs, d_child) {
1005 if (d_really_is_positive(child)) /* probably unneeded */
1006 d_inode(child)->i_private = NULL;
1007 }
1008 spin_unlock(&dir->d_lock);
1009
1010 tracefs_remove(dir);
1011 }
1012
1013 list_del(&file->list);
1014 remove_subsystem(file->system);
1015 free_event_filter(file->filter);
1016 kmem_cache_free(file_cachep, file);
1017}
1018
1019/*
1020 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
1021 */
1022static int
1023__ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
1024 const char *sub, const char *event, int set)
1025{
1026 struct trace_event_file *file;
1027 struct trace_event_call *call;
1028 const char *name;
1029 int ret = -EINVAL;
1030 int eret = 0;
1031
1032 list_for_each_entry(file, &tr->events, list) {
1033
1034 call = file->event_call;
1035 name = trace_event_name(call);
1036
1037 if (!name || !call->class || !call->class->reg)
1038 continue;
1039
1040 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1041 continue;
1042
1043 if (match &&
1044 strcmp(match, name) != 0 &&
1045 strcmp(match, call->class->system) != 0)
1046 continue;
1047
1048 if (sub && strcmp(sub, call->class->system) != 0)
1049 continue;
1050
1051 if (event && strcmp(event, name) != 0)
1052 continue;
1053
1054 ret = ftrace_event_enable_disable(file, set);
1055
1056 /*
1057 * Save the first error and return that. Some events
1058 * may still have been enabled, but let the user
1059 * know that something went wrong.
1060 */
1061 if (ret && !eret)
1062 eret = ret;
1063
1064 ret = eret;
1065 }
1066
1067 return ret;
1068}
1069
1070static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
1071 const char *sub, const char *event, int set)
1072{
1073 int ret;
1074
1075 mutex_lock(&event_mutex);
1076 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
1077 mutex_unlock(&event_mutex);
1078
1079 return ret;
1080}
1081
1082int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
1083{
1084 char *event = NULL, *sub = NULL, *match;
1085 int ret;
1086
1087 if (!tr)
1088 return -ENOENT;
1089 /*
1090 * The buf format can be <subsystem>:<event-name>
1091 * *:<event-name> means any event by that name.
1092 * :<event-name> is the same.
1093 *
1094 * <subsystem>:* means all events in that subsystem
1095 * <subsystem>: means the same.
1096 *
1097 * <name> (no ':') means all events in a subsystem with
1098 * the name <name> or any event that matches <name>
1099 */
1100
1101 match = strsep(&buf, ":");
1102 if (buf) {
1103 sub = match;
1104 event = buf;
1105 match = NULL;
1106
1107 if (!strlen(sub) || strcmp(sub, "*") == 0)
1108 sub = NULL;
1109 if (!strlen(event) || strcmp(event, "*") == 0)
1110 event = NULL;
1111 }
1112
1113 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
1114
1115 /* Put back the colon to allow this to be called again */
1116 if (buf)
1117 *(buf - 1) = ':';
1118
1119 return ret;
1120}
1121
1122/**
1123 * trace_set_clr_event - enable or disable an event
1124 * @system: system name to match (NULL for any system)
1125 * @event: event name to match (NULL for all events, within system)
1126 * @set: 1 to enable, 0 to disable
1127 *
1128 * This is a way for other parts of the kernel to enable or disable
1129 * event recording.
1130 *
1131 * Returns 0 on success, -EINVAL if the parameters do not match any
1132 * registered events.
1133 */
1134int trace_set_clr_event(const char *system, const char *event, int set)
1135{
1136 struct trace_array *tr = top_trace_array();
1137
1138 if (!tr)
1139 return -ENODEV;
1140
1141 return __ftrace_set_clr_event(tr, NULL, system, event, set);
1142}
1143EXPORT_SYMBOL_GPL(trace_set_clr_event);
1144
1145/**
1146 * trace_array_set_clr_event - enable or disable an event for a trace array.
1147 * @tr: concerned trace array.
1148 * @system: system name to match (NULL for any system)
1149 * @event: event name to match (NULL for all events, within system)
1150 * @enable: true to enable, false to disable
1151 *
1152 * This is a way for other parts of the kernel to enable or disable
1153 * event recording.
1154 *
1155 * Returns 0 on success, -EINVAL if the parameters do not match any
1156 * registered events.
1157 */
1158int trace_array_set_clr_event(struct trace_array *tr, const char *system,
1159 const char *event, bool enable)
1160{
1161 int set;
1162
1163 if (!tr)
1164 return -ENOENT;
1165
1166 set = (enable == true) ? 1 : 0;
1167 return __ftrace_set_clr_event(tr, NULL, system, event, set);
1168}
1169EXPORT_SYMBOL_GPL(trace_array_set_clr_event);
1170
1171/* 128 should be much more than enough */
1172#define EVENT_BUF_SIZE 127
1173
1174static ssize_t
1175ftrace_event_write(struct file *file, const char __user *ubuf,
1176 size_t cnt, loff_t *ppos)
1177{
1178 struct trace_parser parser;
1179 struct seq_file *m = file->private_data;
1180 struct trace_array *tr = m->private;
1181 ssize_t read, ret;
1182
1183 if (!cnt)
1184 return 0;
1185
1186 ret = tracing_update_buffers();
1187 if (ret < 0)
1188 return ret;
1189
1190 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
1191 return -ENOMEM;
1192
1193 read = trace_get_user(&parser, ubuf, cnt, ppos);
1194
1195 if (read >= 0 && trace_parser_loaded((&parser))) {
1196 int set = 1;
1197
1198 if (*parser.buffer == '!')
1199 set = 0;
1200
1201 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
1202 if (ret)
1203 goto out_put;
1204 }
1205
1206 ret = read;
1207
1208 out_put:
1209 trace_parser_put(&parser);
1210
1211 return ret;
1212}
1213
1214static void *
1215t_next(struct seq_file *m, void *v, loff_t *pos)
1216{
1217 struct trace_event_file *file = v;
1218 struct trace_event_call *call;
1219 struct trace_array *tr = m->private;
1220
1221 (*pos)++;
1222
1223 list_for_each_entry_continue(file, &tr->events, list) {
1224 call = file->event_call;
1225 /*
1226 * The ftrace subsystem is for showing formats only.
1227 * They can not be enabled or disabled via the event files.
1228 */
1229 if (call->class && call->class->reg &&
1230 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1231 return file;
1232 }
1233
1234 return NULL;
1235}
1236
1237static void *t_start(struct seq_file *m, loff_t *pos)
1238{
1239 struct trace_event_file *file;
1240 struct trace_array *tr = m->private;
1241 loff_t l;
1242
1243 mutex_lock(&event_mutex);
1244
1245 file = list_entry(&tr->events, struct trace_event_file, list);
1246 for (l = 0; l <= *pos; ) {
1247 file = t_next(m, file, &l);
1248 if (!file)
1249 break;
1250 }
1251 return file;
1252}
1253
1254static void *
1255s_next(struct seq_file *m, void *v, loff_t *pos)
1256{
1257 struct trace_event_file *file = v;
1258 struct trace_array *tr = m->private;
1259
1260 (*pos)++;
1261
1262 list_for_each_entry_continue(file, &tr->events, list) {
1263 if (file->flags & EVENT_FILE_FL_ENABLED)
1264 return file;
1265 }
1266
1267 return NULL;
1268}
1269
1270static void *s_start(struct seq_file *m, loff_t *pos)
1271{
1272 struct trace_event_file *file;
1273 struct trace_array *tr = m->private;
1274 loff_t l;
1275
1276 mutex_lock(&event_mutex);
1277
1278 file = list_entry(&tr->events, struct trace_event_file, list);
1279 for (l = 0; l <= *pos; ) {
1280 file = s_next(m, file, &l);
1281 if (!file)
1282 break;
1283 }
1284 return file;
1285}
1286
1287static int t_show(struct seq_file *m, void *v)
1288{
1289 struct trace_event_file *file = v;
1290 struct trace_event_call *call = file->event_call;
1291
1292 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1293 seq_printf(m, "%s:", call->class->system);
1294 seq_printf(m, "%s\n", trace_event_name(call));
1295
1296 return 0;
1297}
1298
1299static void t_stop(struct seq_file *m, void *p)
1300{
1301 mutex_unlock(&event_mutex);
1302}
1303
1304static void *
1305__next(struct seq_file *m, void *v, loff_t *pos, int type)
1306{
1307 struct trace_array *tr = m->private;
1308 struct trace_pid_list *pid_list;
1309
1310 if (type == TRACE_PIDS)
1311 pid_list = rcu_dereference_sched(tr->filtered_pids);
1312 else
1313 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1314
1315 return trace_pid_next(pid_list, v, pos);
1316}
1317
1318static void *
1319p_next(struct seq_file *m, void *v, loff_t *pos)
1320{
1321 return __next(m, v, pos, TRACE_PIDS);
1322}
1323
1324static void *
1325np_next(struct seq_file *m, void *v, loff_t *pos)
1326{
1327 return __next(m, v, pos, TRACE_NO_PIDS);
1328}
1329
1330static void *__start(struct seq_file *m, loff_t *pos, int type)
1331 __acquires(RCU)
1332{
1333 struct trace_pid_list *pid_list;
1334 struct trace_array *tr = m->private;
1335
1336 /*
1337 * Grab the mutex, to keep calls to p_next() having the same
1338 * tr->filtered_pids as p_start() has.
1339 * If we just passed the tr->filtered_pids around, then RCU would
1340 * have been enough, but doing that makes things more complex.
1341 */
1342 mutex_lock(&event_mutex);
1343 rcu_read_lock_sched();
1344
1345 if (type == TRACE_PIDS)
1346 pid_list = rcu_dereference_sched(tr->filtered_pids);
1347 else
1348 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1349
1350 if (!pid_list)
1351 return NULL;
1352
1353 return trace_pid_start(pid_list, pos);
1354}
1355
1356static void *p_start(struct seq_file *m, loff_t *pos)
1357 __acquires(RCU)
1358{
1359 return __start(m, pos, TRACE_PIDS);
1360}
1361
1362static void *np_start(struct seq_file *m, loff_t *pos)
1363 __acquires(RCU)
1364{
1365 return __start(m, pos, TRACE_NO_PIDS);
1366}
1367
1368static void p_stop(struct seq_file *m, void *p)
1369 __releases(RCU)
1370{
1371 rcu_read_unlock_sched();
1372 mutex_unlock(&event_mutex);
1373}
1374
1375static ssize_t
1376event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1377 loff_t *ppos)
1378{
1379 struct trace_event_file *file;
1380 unsigned long flags;
1381 char buf[4] = "0";
1382
1383 mutex_lock(&event_mutex);
1384 file = event_file_data(filp);
1385 if (likely(file))
1386 flags = file->flags;
1387 mutex_unlock(&event_mutex);
1388
1389 if (!file)
1390 return -ENODEV;
1391
1392 if (flags & EVENT_FILE_FL_ENABLED &&
1393 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1394 strcpy(buf, "1");
1395
1396 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1397 flags & EVENT_FILE_FL_SOFT_MODE)
1398 strcat(buf, "*");
1399
1400 strcat(buf, "\n");
1401
1402 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1403}
1404
1405static ssize_t
1406event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1407 loff_t *ppos)
1408{
1409 struct trace_event_file *file;
1410 unsigned long val;
1411 int ret;
1412
1413 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1414 if (ret)
1415 return ret;
1416
1417 ret = tracing_update_buffers();
1418 if (ret < 0)
1419 return ret;
1420
1421 switch (val) {
1422 case 0:
1423 case 1:
1424 ret = -ENODEV;
1425 mutex_lock(&event_mutex);
1426 file = event_file_data(filp);
1427 if (likely(file))
1428 ret = ftrace_event_enable_disable(file, val);
1429 mutex_unlock(&event_mutex);
1430 break;
1431
1432 default:
1433 return -EINVAL;
1434 }
1435
1436 *ppos += cnt;
1437
1438 return ret ? ret : cnt;
1439}
1440
1441static ssize_t
1442system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1443 loff_t *ppos)
1444{
1445 const char set_to_char[4] = { '?', '0', '1', 'X' };
1446 struct trace_subsystem_dir *dir = filp->private_data;
1447 struct event_subsystem *system = dir->subsystem;
1448 struct trace_event_call *call;
1449 struct trace_event_file *file;
1450 struct trace_array *tr = dir->tr;
1451 char buf[2];
1452 int set = 0;
1453 int ret;
1454
1455 mutex_lock(&event_mutex);
1456 list_for_each_entry(file, &tr->events, list) {
1457 call = file->event_call;
1458 if ((call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) ||
1459 !trace_event_name(call) || !call->class || !call->class->reg)
1460 continue;
1461
1462 if (system && strcmp(call->class->system, system->name) != 0)
1463 continue;
1464
1465 /*
1466 * We need to find out if all the events are set
1467 * or if all events or cleared, or if we have
1468 * a mixture.
1469 */
1470 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1471
1472 /*
1473 * If we have a mixture, no need to look further.
1474 */
1475 if (set == 3)
1476 break;
1477 }
1478 mutex_unlock(&event_mutex);
1479
1480 buf[0] = set_to_char[set];
1481 buf[1] = '\n';
1482
1483 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1484
1485 return ret;
1486}
1487
1488static ssize_t
1489system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1490 loff_t *ppos)
1491{
1492 struct trace_subsystem_dir *dir = filp->private_data;
1493 struct event_subsystem *system = dir->subsystem;
1494 const char *name = NULL;
1495 unsigned long val;
1496 ssize_t ret;
1497
1498 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1499 if (ret)
1500 return ret;
1501
1502 ret = tracing_update_buffers();
1503 if (ret < 0)
1504 return ret;
1505
1506 if (val != 0 && val != 1)
1507 return -EINVAL;
1508
1509 /*
1510 * Opening of "enable" adds a ref count to system,
1511 * so the name is safe to use.
1512 */
1513 if (system)
1514 name = system->name;
1515
1516 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1517 if (ret)
1518 goto out;
1519
1520 ret = cnt;
1521
1522out:
1523 *ppos += cnt;
1524
1525 return ret;
1526}
1527
1528enum {
1529 FORMAT_HEADER = 1,
1530 FORMAT_FIELD_SEPERATOR = 2,
1531 FORMAT_PRINTFMT = 3,
1532};
1533
1534static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1535{
1536 struct trace_event_call *call = event_file_data(m->private);
1537 struct list_head *common_head = &ftrace_common_fields;
1538 struct list_head *head = trace_get_fields(call);
1539 struct list_head *node = v;
1540
1541 (*pos)++;
1542
1543 switch ((unsigned long)v) {
1544 case FORMAT_HEADER:
1545 node = common_head;
1546 break;
1547
1548 case FORMAT_FIELD_SEPERATOR:
1549 node = head;
1550 break;
1551
1552 case FORMAT_PRINTFMT:
1553 /* all done */
1554 return NULL;
1555 }
1556
1557 node = node->prev;
1558 if (node == common_head)
1559 return (void *)FORMAT_FIELD_SEPERATOR;
1560 else if (node == head)
1561 return (void *)FORMAT_PRINTFMT;
1562 else
1563 return node;
1564}
1565
1566static int f_show(struct seq_file *m, void *v)
1567{
1568 struct trace_event_call *call = event_file_data(m->private);
1569 struct ftrace_event_field *field;
1570 const char *array_descriptor;
1571
1572 switch ((unsigned long)v) {
1573 case FORMAT_HEADER:
1574 seq_printf(m, "name: %s\n", trace_event_name(call));
1575 seq_printf(m, "ID: %d\n", call->event.type);
1576 seq_puts(m, "format:\n");
1577 return 0;
1578
1579 case FORMAT_FIELD_SEPERATOR:
1580 seq_putc(m, '\n');
1581 return 0;
1582
1583 case FORMAT_PRINTFMT:
1584 seq_printf(m, "\nprint fmt: %s\n",
1585 call->print_fmt);
1586 return 0;
1587 }
1588
1589 field = list_entry(v, struct ftrace_event_field, link);
1590 /*
1591 * Smartly shows the array type(except dynamic array).
1592 * Normal:
1593 * field:TYPE VAR
1594 * If TYPE := TYPE[LEN], it is shown:
1595 * field:TYPE VAR[LEN]
1596 */
1597 array_descriptor = strchr(field->type, '[');
1598
1599 if (str_has_prefix(field->type, "__data_loc"))
1600 array_descriptor = NULL;
1601
1602 if (!array_descriptor)
1603 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1604 field->type, field->name, field->offset,
1605 field->size, !!field->is_signed);
1606 else if (field->len)
1607 seq_printf(m, "\tfield:%.*s %s[%d];\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1608 (int)(array_descriptor - field->type),
1609 field->type, field->name,
1610 field->len, field->offset,
1611 field->size, !!field->is_signed);
1612 else
1613 seq_printf(m, "\tfield:%.*s %s[];\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1614 (int)(array_descriptor - field->type),
1615 field->type, field->name,
1616 field->offset, field->size, !!field->is_signed);
1617
1618 return 0;
1619}
1620
1621static void *f_start(struct seq_file *m, loff_t *pos)
1622{
1623 void *p = (void *)FORMAT_HEADER;
1624 loff_t l = 0;
1625
1626 /* ->stop() is called even if ->start() fails */
1627 mutex_lock(&event_mutex);
1628 if (!event_file_data(m->private))
1629 return ERR_PTR(-ENODEV);
1630
1631 while (l < *pos && p)
1632 p = f_next(m, p, &l);
1633
1634 return p;
1635}
1636
1637static void f_stop(struct seq_file *m, void *p)
1638{
1639 mutex_unlock(&event_mutex);
1640}
1641
1642static const struct seq_operations trace_format_seq_ops = {
1643 .start = f_start,
1644 .next = f_next,
1645 .stop = f_stop,
1646 .show = f_show,
1647};
1648
1649static int trace_format_open(struct inode *inode, struct file *file)
1650{
1651 struct seq_file *m;
1652 int ret;
1653
1654 /* Do we want to hide event format files on tracefs lockdown? */
1655
1656 ret = seq_open(file, &trace_format_seq_ops);
1657 if (ret < 0)
1658 return ret;
1659
1660 m = file->private_data;
1661 m->private = file;
1662
1663 return 0;
1664}
1665
1666static ssize_t
1667event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1668{
1669 int id = (long)event_file_data(filp);
1670 char buf[32];
1671 int len;
1672
1673 if (unlikely(!id))
1674 return -ENODEV;
1675
1676 len = sprintf(buf, "%d\n", id);
1677
1678 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1679}
1680
1681static ssize_t
1682event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1683 loff_t *ppos)
1684{
1685 struct trace_event_file *file;
1686 struct trace_seq *s;
1687 int r = -ENODEV;
1688
1689 if (*ppos)
1690 return 0;
1691
1692 s = kmalloc(sizeof(*s), GFP_KERNEL);
1693
1694 if (!s)
1695 return -ENOMEM;
1696
1697 trace_seq_init(s);
1698
1699 mutex_lock(&event_mutex);
1700 file = event_file_data(filp);
1701 if (file)
1702 print_event_filter(file, s);
1703 mutex_unlock(&event_mutex);
1704
1705 if (file)
1706 r = simple_read_from_buffer(ubuf, cnt, ppos,
1707 s->buffer, trace_seq_used(s));
1708
1709 kfree(s);
1710
1711 return r;
1712}
1713
1714static ssize_t
1715event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1716 loff_t *ppos)
1717{
1718 struct trace_event_file *file;
1719 char *buf;
1720 int err = -ENODEV;
1721
1722 if (cnt >= PAGE_SIZE)
1723 return -EINVAL;
1724
1725 buf = memdup_user_nul(ubuf, cnt);
1726 if (IS_ERR(buf))
1727 return PTR_ERR(buf);
1728
1729 mutex_lock(&event_mutex);
1730 file = event_file_data(filp);
1731 if (file)
1732 err = apply_event_filter(file, buf);
1733 mutex_unlock(&event_mutex);
1734
1735 kfree(buf);
1736 if (err < 0)
1737 return err;
1738
1739 *ppos += cnt;
1740
1741 return cnt;
1742}
1743
1744static LIST_HEAD(event_subsystems);
1745
1746static int subsystem_open(struct inode *inode, struct file *filp)
1747{
1748 struct trace_subsystem_dir *dir = NULL, *iter_dir;
1749 struct trace_array *tr = NULL, *iter_tr;
1750 struct event_subsystem *system = NULL;
1751 int ret;
1752
1753 if (tracing_is_disabled())
1754 return -ENODEV;
1755
1756 /* Make sure the system still exists */
1757 mutex_lock(&event_mutex);
1758 mutex_lock(&trace_types_lock);
1759 list_for_each_entry(iter_tr, &ftrace_trace_arrays, list) {
1760 list_for_each_entry(iter_dir, &iter_tr->systems, list) {
1761 if (iter_dir == inode->i_private) {
1762 /* Don't open systems with no events */
1763 tr = iter_tr;
1764 dir = iter_dir;
1765 if (dir->nr_events) {
1766 __get_system_dir(dir);
1767 system = dir->subsystem;
1768 }
1769 goto exit_loop;
1770 }
1771 }
1772 }
1773 exit_loop:
1774 mutex_unlock(&trace_types_lock);
1775 mutex_unlock(&event_mutex);
1776
1777 if (!system)
1778 return -ENODEV;
1779
1780 /* Still need to increment the ref count of the system */
1781 if (trace_array_get(tr) < 0) {
1782 put_system(dir);
1783 return -ENODEV;
1784 }
1785
1786 ret = tracing_open_generic(inode, filp);
1787 if (ret < 0) {
1788 trace_array_put(tr);
1789 put_system(dir);
1790 }
1791
1792 return ret;
1793}
1794
1795static int system_tr_open(struct inode *inode, struct file *filp)
1796{
1797 struct trace_subsystem_dir *dir;
1798 struct trace_array *tr = inode->i_private;
1799 int ret;
1800
1801 /* Make a temporary dir that has no system but points to tr */
1802 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1803 if (!dir)
1804 return -ENOMEM;
1805
1806 ret = tracing_open_generic_tr(inode, filp);
1807 if (ret < 0) {
1808 kfree(dir);
1809 return ret;
1810 }
1811 dir->tr = tr;
1812 filp->private_data = dir;
1813
1814 return 0;
1815}
1816
1817static int subsystem_release(struct inode *inode, struct file *file)
1818{
1819 struct trace_subsystem_dir *dir = file->private_data;
1820
1821 trace_array_put(dir->tr);
1822
1823 /*
1824 * If dir->subsystem is NULL, then this is a temporary
1825 * descriptor that was made for a trace_array to enable
1826 * all subsystems.
1827 */
1828 if (dir->subsystem)
1829 put_system(dir);
1830 else
1831 kfree(dir);
1832
1833 return 0;
1834}
1835
1836static ssize_t
1837subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1838 loff_t *ppos)
1839{
1840 struct trace_subsystem_dir *dir = filp->private_data;
1841 struct event_subsystem *system = dir->subsystem;
1842 struct trace_seq *s;
1843 int r;
1844
1845 if (*ppos)
1846 return 0;
1847
1848 s = kmalloc(sizeof(*s), GFP_KERNEL);
1849 if (!s)
1850 return -ENOMEM;
1851
1852 trace_seq_init(s);
1853
1854 print_subsystem_event_filter(system, s);
1855 r = simple_read_from_buffer(ubuf, cnt, ppos,
1856 s->buffer, trace_seq_used(s));
1857
1858 kfree(s);
1859
1860 return r;
1861}
1862
1863static ssize_t
1864subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1865 loff_t *ppos)
1866{
1867 struct trace_subsystem_dir *dir = filp->private_data;
1868 char *buf;
1869 int err;
1870
1871 if (cnt >= PAGE_SIZE)
1872 return -EINVAL;
1873
1874 buf = memdup_user_nul(ubuf, cnt);
1875 if (IS_ERR(buf))
1876 return PTR_ERR(buf);
1877
1878 err = apply_subsystem_event_filter(dir, buf);
1879 kfree(buf);
1880 if (err < 0)
1881 return err;
1882
1883 *ppos += cnt;
1884
1885 return cnt;
1886}
1887
1888static ssize_t
1889show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1890{
1891 int (*func)(struct trace_seq *s) = filp->private_data;
1892 struct trace_seq *s;
1893 int r;
1894
1895 if (*ppos)
1896 return 0;
1897
1898 s = kmalloc(sizeof(*s), GFP_KERNEL);
1899 if (!s)
1900 return -ENOMEM;
1901
1902 trace_seq_init(s);
1903
1904 func(s);
1905 r = simple_read_from_buffer(ubuf, cnt, ppos,
1906 s->buffer, trace_seq_used(s));
1907
1908 kfree(s);
1909
1910 return r;
1911}
1912
1913static void ignore_task_cpu(void *data)
1914{
1915 struct trace_array *tr = data;
1916 struct trace_pid_list *pid_list;
1917 struct trace_pid_list *no_pid_list;
1918
1919 /*
1920 * This function is called by on_each_cpu() while the
1921 * event_mutex is held.
1922 */
1923 pid_list = rcu_dereference_protected(tr->filtered_pids,
1924 mutex_is_locked(&event_mutex));
1925 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
1926 mutex_is_locked(&event_mutex));
1927
1928 this_cpu_write(tr->array_buffer.data->ignore_pid,
1929 trace_ignore_this_task(pid_list, no_pid_list, current));
1930}
1931
1932static void register_pid_events(struct trace_array *tr)
1933{
1934 /*
1935 * Register a probe that is called before all other probes
1936 * to set ignore_pid if next or prev do not match.
1937 * Register a probe this is called after all other probes
1938 * to only keep ignore_pid set if next pid matches.
1939 */
1940 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1941 tr, INT_MAX);
1942 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1943 tr, 0);
1944
1945 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1946 tr, INT_MAX);
1947 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1948 tr, 0);
1949
1950 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1951 tr, INT_MAX);
1952 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1953 tr, 0);
1954
1955 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1956 tr, INT_MAX);
1957 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1958 tr, 0);
1959}
1960
1961static ssize_t
1962event_pid_write(struct file *filp, const char __user *ubuf,
1963 size_t cnt, loff_t *ppos, int type)
1964{
1965 struct seq_file *m = filp->private_data;
1966 struct trace_array *tr = m->private;
1967 struct trace_pid_list *filtered_pids = NULL;
1968 struct trace_pid_list *other_pids = NULL;
1969 struct trace_pid_list *pid_list;
1970 struct trace_event_file *file;
1971 ssize_t ret;
1972
1973 if (!cnt)
1974 return 0;
1975
1976 ret = tracing_update_buffers();
1977 if (ret < 0)
1978 return ret;
1979
1980 mutex_lock(&event_mutex);
1981
1982 if (type == TRACE_PIDS) {
1983 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1984 lockdep_is_held(&event_mutex));
1985 other_pids = rcu_dereference_protected(tr->filtered_no_pids,
1986 lockdep_is_held(&event_mutex));
1987 } else {
1988 filtered_pids = rcu_dereference_protected(tr->filtered_no_pids,
1989 lockdep_is_held(&event_mutex));
1990 other_pids = rcu_dereference_protected(tr->filtered_pids,
1991 lockdep_is_held(&event_mutex));
1992 }
1993
1994 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
1995 if (ret < 0)
1996 goto out;
1997
1998 if (type == TRACE_PIDS)
1999 rcu_assign_pointer(tr->filtered_pids, pid_list);
2000 else
2001 rcu_assign_pointer(tr->filtered_no_pids, pid_list);
2002
2003 list_for_each_entry(file, &tr->events, list) {
2004 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
2005 }
2006
2007 if (filtered_pids) {
2008 tracepoint_synchronize_unregister();
2009 trace_pid_list_free(filtered_pids);
2010 } else if (pid_list && !other_pids) {
2011 register_pid_events(tr);
2012 }
2013
2014 /*
2015 * Ignoring of pids is done at task switch. But we have to
2016 * check for those tasks that are currently running.
2017 * Always do this in case a pid was appended or removed.
2018 */
2019 on_each_cpu(ignore_task_cpu, tr, 1);
2020
2021 out:
2022 mutex_unlock(&event_mutex);
2023
2024 if (ret > 0)
2025 *ppos += ret;
2026
2027 return ret;
2028}
2029
2030static ssize_t
2031ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
2032 size_t cnt, loff_t *ppos)
2033{
2034 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
2035}
2036
2037static ssize_t
2038ftrace_event_npid_write(struct file *filp, const char __user *ubuf,
2039 size_t cnt, loff_t *ppos)
2040{
2041 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
2042}
2043
2044static int ftrace_event_avail_open(struct inode *inode, struct file *file);
2045static int ftrace_event_set_open(struct inode *inode, struct file *file);
2046static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
2047static int ftrace_event_set_npid_open(struct inode *inode, struct file *file);
2048static int ftrace_event_release(struct inode *inode, struct file *file);
2049
2050static const struct seq_operations show_event_seq_ops = {
2051 .start = t_start,
2052 .next = t_next,
2053 .show = t_show,
2054 .stop = t_stop,
2055};
2056
2057static const struct seq_operations show_set_event_seq_ops = {
2058 .start = s_start,
2059 .next = s_next,
2060 .show = t_show,
2061 .stop = t_stop,
2062};
2063
2064static const struct seq_operations show_set_pid_seq_ops = {
2065 .start = p_start,
2066 .next = p_next,
2067 .show = trace_pid_show,
2068 .stop = p_stop,
2069};
2070
2071static const struct seq_operations show_set_no_pid_seq_ops = {
2072 .start = np_start,
2073 .next = np_next,
2074 .show = trace_pid_show,
2075 .stop = p_stop,
2076};
2077
2078static const struct file_operations ftrace_avail_fops = {
2079 .open = ftrace_event_avail_open,
2080 .read = seq_read,
2081 .llseek = seq_lseek,
2082 .release = seq_release,
2083};
2084
2085static const struct file_operations ftrace_set_event_fops = {
2086 .open = ftrace_event_set_open,
2087 .read = seq_read,
2088 .write = ftrace_event_write,
2089 .llseek = seq_lseek,
2090 .release = ftrace_event_release,
2091};
2092
2093static const struct file_operations ftrace_set_event_pid_fops = {
2094 .open = ftrace_event_set_pid_open,
2095 .read = seq_read,
2096 .write = ftrace_event_pid_write,
2097 .llseek = seq_lseek,
2098 .release = ftrace_event_release,
2099};
2100
2101static const struct file_operations ftrace_set_event_notrace_pid_fops = {
2102 .open = ftrace_event_set_npid_open,
2103 .read = seq_read,
2104 .write = ftrace_event_npid_write,
2105 .llseek = seq_lseek,
2106 .release = ftrace_event_release,
2107};
2108
2109static const struct file_operations ftrace_enable_fops = {
2110 .open = tracing_open_generic,
2111 .read = event_enable_read,
2112 .write = event_enable_write,
2113 .llseek = default_llseek,
2114};
2115
2116static const struct file_operations ftrace_event_format_fops = {
2117 .open = trace_format_open,
2118 .read = seq_read,
2119 .llseek = seq_lseek,
2120 .release = seq_release,
2121};
2122
2123static const struct file_operations ftrace_event_id_fops = {
2124 .read = event_id_read,
2125 .llseek = default_llseek,
2126};
2127
2128static const struct file_operations ftrace_event_filter_fops = {
2129 .open = tracing_open_generic,
2130 .read = event_filter_read,
2131 .write = event_filter_write,
2132 .llseek = default_llseek,
2133};
2134
2135static const struct file_operations ftrace_subsystem_filter_fops = {
2136 .open = subsystem_open,
2137 .read = subsystem_filter_read,
2138 .write = subsystem_filter_write,
2139 .llseek = default_llseek,
2140 .release = subsystem_release,
2141};
2142
2143static const struct file_operations ftrace_system_enable_fops = {
2144 .open = subsystem_open,
2145 .read = system_enable_read,
2146 .write = system_enable_write,
2147 .llseek = default_llseek,
2148 .release = subsystem_release,
2149};
2150
2151static const struct file_operations ftrace_tr_enable_fops = {
2152 .open = system_tr_open,
2153 .read = system_enable_read,
2154 .write = system_enable_write,
2155 .llseek = default_llseek,
2156 .release = subsystem_release,
2157};
2158
2159static const struct file_operations ftrace_show_header_fops = {
2160 .open = tracing_open_generic,
2161 .read = show_header,
2162 .llseek = default_llseek,
2163};
2164
2165static int
2166ftrace_event_open(struct inode *inode, struct file *file,
2167 const struct seq_operations *seq_ops)
2168{
2169 struct seq_file *m;
2170 int ret;
2171
2172 ret = security_locked_down(LOCKDOWN_TRACEFS);
2173 if (ret)
2174 return ret;
2175
2176 ret = seq_open(file, seq_ops);
2177 if (ret < 0)
2178 return ret;
2179 m = file->private_data;
2180 /* copy tr over to seq ops */
2181 m->private = inode->i_private;
2182
2183 return ret;
2184}
2185
2186static int ftrace_event_release(struct inode *inode, struct file *file)
2187{
2188 struct trace_array *tr = inode->i_private;
2189
2190 trace_array_put(tr);
2191
2192 return seq_release(inode, file);
2193}
2194
2195static int
2196ftrace_event_avail_open(struct inode *inode, struct file *file)
2197{
2198 const struct seq_operations *seq_ops = &show_event_seq_ops;
2199
2200 /* Checks for tracefs lockdown */
2201 return ftrace_event_open(inode, file, seq_ops);
2202}
2203
2204static int
2205ftrace_event_set_open(struct inode *inode, struct file *file)
2206{
2207 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
2208 struct trace_array *tr = inode->i_private;
2209 int ret;
2210
2211 ret = tracing_check_open_get_tr(tr);
2212 if (ret)
2213 return ret;
2214
2215 if ((file->f_mode & FMODE_WRITE) &&
2216 (file->f_flags & O_TRUNC))
2217 ftrace_clear_events(tr);
2218
2219 ret = ftrace_event_open(inode, file, seq_ops);
2220 if (ret < 0)
2221 trace_array_put(tr);
2222 return ret;
2223}
2224
2225static int
2226ftrace_event_set_pid_open(struct inode *inode, struct file *file)
2227{
2228 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
2229 struct trace_array *tr = inode->i_private;
2230 int ret;
2231
2232 ret = tracing_check_open_get_tr(tr);
2233 if (ret)
2234 return ret;
2235
2236 if ((file->f_mode & FMODE_WRITE) &&
2237 (file->f_flags & O_TRUNC))
2238 ftrace_clear_event_pids(tr, TRACE_PIDS);
2239
2240 ret = ftrace_event_open(inode, file, seq_ops);
2241 if (ret < 0)
2242 trace_array_put(tr);
2243 return ret;
2244}
2245
2246static int
2247ftrace_event_set_npid_open(struct inode *inode, struct file *file)
2248{
2249 const struct seq_operations *seq_ops = &show_set_no_pid_seq_ops;
2250 struct trace_array *tr = inode->i_private;
2251 int ret;
2252
2253 ret = tracing_check_open_get_tr(tr);
2254 if (ret)
2255 return ret;
2256
2257 if ((file->f_mode & FMODE_WRITE) &&
2258 (file->f_flags & O_TRUNC))
2259 ftrace_clear_event_pids(tr, TRACE_NO_PIDS);
2260
2261 ret = ftrace_event_open(inode, file, seq_ops);
2262 if (ret < 0)
2263 trace_array_put(tr);
2264 return ret;
2265}
2266
2267static struct event_subsystem *
2268create_new_subsystem(const char *name)
2269{
2270 struct event_subsystem *system;
2271
2272 /* need to create new entry */
2273 system = kmalloc(sizeof(*system), GFP_KERNEL);
2274 if (!system)
2275 return NULL;
2276
2277 system->ref_count = 1;
2278
2279 /* Only allocate if dynamic (kprobes and modules) */
2280 system->name = kstrdup_const(name, GFP_KERNEL);
2281 if (!system->name)
2282 goto out_free;
2283
2284 system->filter = NULL;
2285
2286 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
2287 if (!system->filter)
2288 goto out_free;
2289
2290 list_add(&system->list, &event_subsystems);
2291
2292 return system;
2293
2294 out_free:
2295 kfree_const(system->name);
2296 kfree(system);
2297 return NULL;
2298}
2299
2300static struct dentry *
2301event_subsystem_dir(struct trace_array *tr, const char *name,
2302 struct trace_event_file *file, struct dentry *parent)
2303{
2304 struct event_subsystem *system, *iter;
2305 struct trace_subsystem_dir *dir;
2306 struct dentry *entry;
2307
2308 /* First see if we did not already create this dir */
2309 list_for_each_entry(dir, &tr->systems, list) {
2310 system = dir->subsystem;
2311 if (strcmp(system->name, name) == 0) {
2312 dir->nr_events++;
2313 file->system = dir;
2314 return dir->entry;
2315 }
2316 }
2317
2318 /* Now see if the system itself exists. */
2319 system = NULL;
2320 list_for_each_entry(iter, &event_subsystems, list) {
2321 if (strcmp(iter->name, name) == 0) {
2322 system = iter;
2323 break;
2324 }
2325 }
2326
2327 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
2328 if (!dir)
2329 goto out_fail;
2330
2331 if (!system) {
2332 system = create_new_subsystem(name);
2333 if (!system)
2334 goto out_free;
2335 } else
2336 __get_system(system);
2337
2338 dir->entry = tracefs_create_dir(name, parent);
2339 if (!dir->entry) {
2340 pr_warn("Failed to create system directory %s\n", name);
2341 __put_system(system);
2342 goto out_free;
2343 }
2344
2345 dir->tr = tr;
2346 dir->ref_count = 1;
2347 dir->nr_events = 1;
2348 dir->subsystem = system;
2349 file->system = dir;
2350
2351 /* the ftrace system is special, do not create enable or filter files */
2352 if (strcmp(name, "ftrace") != 0) {
2353
2354 entry = tracefs_create_file("filter", TRACE_MODE_WRITE,
2355 dir->entry, dir,
2356 &ftrace_subsystem_filter_fops);
2357 if (!entry) {
2358 kfree(system->filter);
2359 system->filter = NULL;
2360 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
2361 }
2362
2363 trace_create_file("enable", TRACE_MODE_WRITE, dir->entry, dir,
2364 &ftrace_system_enable_fops);
2365 }
2366
2367 list_add(&dir->list, &tr->systems);
2368
2369 return dir->entry;
2370
2371 out_free:
2372 kfree(dir);
2373 out_fail:
2374 /* Only print this message if failed on memory allocation */
2375 if (!dir || !system)
2376 pr_warn("No memory to create event subsystem %s\n", name);
2377 return NULL;
2378}
2379
2380static int
2381event_define_fields(struct trace_event_call *call)
2382{
2383 struct list_head *head;
2384 int ret = 0;
2385
2386 /*
2387 * Other events may have the same class. Only update
2388 * the fields if they are not already defined.
2389 */
2390 head = trace_get_fields(call);
2391 if (list_empty(head)) {
2392 struct trace_event_fields *field = call->class->fields_array;
2393 unsigned int offset = sizeof(struct trace_entry);
2394
2395 for (; field->type; field++) {
2396 if (field->type == TRACE_FUNCTION_TYPE) {
2397 field->define_fields(call);
2398 break;
2399 }
2400
2401 offset = ALIGN(offset, field->align);
2402 ret = trace_define_field_ext(call, field->type, field->name,
2403 offset, field->size,
2404 field->is_signed, field->filter_type,
2405 field->len);
2406 if (WARN_ON_ONCE(ret)) {
2407 pr_err("error code is %d\n", ret);
2408 break;
2409 }
2410
2411 offset += field->size;
2412 }
2413 }
2414
2415 return ret;
2416}
2417
2418static int
2419event_create_dir(struct dentry *parent, struct trace_event_file *file)
2420{
2421 struct trace_event_call *call = file->event_call;
2422 struct trace_array *tr = file->tr;
2423 struct dentry *d_events;
2424 const char *name;
2425 int ret;
2426
2427 /*
2428 * If the trace point header did not define TRACE_SYSTEM
2429 * then the system would be called "TRACE_SYSTEM".
2430 */
2431 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
2432 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
2433 if (!d_events)
2434 return -ENOMEM;
2435 } else
2436 d_events = parent;
2437
2438 name = trace_event_name(call);
2439 file->dir = tracefs_create_dir(name, d_events);
2440 if (!file->dir) {
2441 pr_warn("Could not create tracefs '%s' directory\n", name);
2442 return -1;
2443 }
2444
2445 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2446 trace_create_file("enable", TRACE_MODE_WRITE, file->dir, file,
2447 &ftrace_enable_fops);
2448
2449#ifdef CONFIG_PERF_EVENTS
2450 if (call->event.type && call->class->reg)
2451 trace_create_file("id", TRACE_MODE_READ, file->dir,
2452 (void *)(long)call->event.type,
2453 &ftrace_event_id_fops);
2454#endif
2455
2456 ret = event_define_fields(call);
2457 if (ret < 0) {
2458 pr_warn("Could not initialize trace point events/%s\n", name);
2459 return ret;
2460 }
2461
2462 /*
2463 * Only event directories that can be enabled should have
2464 * triggers or filters.
2465 */
2466 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
2467 trace_create_file("filter", TRACE_MODE_WRITE, file->dir,
2468 file, &ftrace_event_filter_fops);
2469
2470 trace_create_file("trigger", TRACE_MODE_WRITE, file->dir,
2471 file, &event_trigger_fops);
2472 }
2473
2474#ifdef CONFIG_HIST_TRIGGERS
2475 trace_create_file("hist", TRACE_MODE_READ, file->dir, file,
2476 &event_hist_fops);
2477#endif
2478#ifdef CONFIG_HIST_TRIGGERS_DEBUG
2479 trace_create_file("hist_debug", TRACE_MODE_READ, file->dir, file,
2480 &event_hist_debug_fops);
2481#endif
2482 trace_create_file("format", TRACE_MODE_READ, file->dir, call,
2483 &ftrace_event_format_fops);
2484
2485#ifdef CONFIG_TRACE_EVENT_INJECT
2486 if (call->event.type && call->class->reg)
2487 trace_create_file("inject", 0200, file->dir, file,
2488 &event_inject_fops);
2489#endif
2490
2491 return 0;
2492}
2493
2494static void remove_event_from_tracers(struct trace_event_call *call)
2495{
2496 struct trace_event_file *file;
2497 struct trace_array *tr;
2498
2499 do_for_each_event_file_safe(tr, file) {
2500 if (file->event_call != call)
2501 continue;
2502
2503 remove_event_file_dir(file);
2504 /*
2505 * The do_for_each_event_file_safe() is
2506 * a double loop. After finding the call for this
2507 * trace_array, we use break to jump to the next
2508 * trace_array.
2509 */
2510 break;
2511 } while_for_each_event_file();
2512}
2513
2514static void event_remove(struct trace_event_call *call)
2515{
2516 struct trace_array *tr;
2517 struct trace_event_file *file;
2518
2519 do_for_each_event_file(tr, file) {
2520 if (file->event_call != call)
2521 continue;
2522
2523 if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
2524 tr->clear_trace = true;
2525
2526 ftrace_event_enable_disable(file, 0);
2527 /*
2528 * The do_for_each_event_file() is
2529 * a double loop. After finding the call for this
2530 * trace_array, we use break to jump to the next
2531 * trace_array.
2532 */
2533 break;
2534 } while_for_each_event_file();
2535
2536 if (call->event.funcs)
2537 __unregister_trace_event(&call->event);
2538 remove_event_from_tracers(call);
2539 list_del(&call->list);
2540}
2541
2542static int event_init(struct trace_event_call *call)
2543{
2544 int ret = 0;
2545 const char *name;
2546
2547 name = trace_event_name(call);
2548 if (WARN_ON(!name))
2549 return -EINVAL;
2550
2551 if (call->class->raw_init) {
2552 ret = call->class->raw_init(call);
2553 if (ret < 0 && ret != -ENOSYS)
2554 pr_warn("Could not initialize trace events/%s\n", name);
2555 }
2556
2557 return ret;
2558}
2559
2560static int
2561__register_event(struct trace_event_call *call, struct module *mod)
2562{
2563 int ret;
2564
2565 ret = event_init(call);
2566 if (ret < 0)
2567 return ret;
2568
2569 list_add(&call->list, &ftrace_events);
2570 if (call->flags & TRACE_EVENT_FL_DYNAMIC)
2571 atomic_set(&call->refcnt, 0);
2572 else
2573 call->module = mod;
2574
2575 return 0;
2576}
2577
2578static char *eval_replace(char *ptr, struct trace_eval_map *map, int len)
2579{
2580 int rlen;
2581 int elen;
2582
2583 /* Find the length of the eval value as a string */
2584 elen = snprintf(ptr, 0, "%ld", map->eval_value);
2585 /* Make sure there's enough room to replace the string with the value */
2586 if (len < elen)
2587 return NULL;
2588
2589 snprintf(ptr, elen + 1, "%ld", map->eval_value);
2590
2591 /* Get the rest of the string of ptr */
2592 rlen = strlen(ptr + len);
2593 memmove(ptr + elen, ptr + len, rlen);
2594 /* Make sure we end the new string */
2595 ptr[elen + rlen] = 0;
2596
2597 return ptr + elen;
2598}
2599
2600static void update_event_printk(struct trace_event_call *call,
2601 struct trace_eval_map *map)
2602{
2603 char *ptr;
2604 int quote = 0;
2605 int len = strlen(map->eval_string);
2606
2607 for (ptr = call->print_fmt; *ptr; ptr++) {
2608 if (*ptr == '\\') {
2609 ptr++;
2610 /* paranoid */
2611 if (!*ptr)
2612 break;
2613 continue;
2614 }
2615 if (*ptr == '"') {
2616 quote ^= 1;
2617 continue;
2618 }
2619 if (quote)
2620 continue;
2621 if (isdigit(*ptr)) {
2622 /* skip numbers */
2623 do {
2624 ptr++;
2625 /* Check for alpha chars like ULL */
2626 } while (isalnum(*ptr));
2627 if (!*ptr)
2628 break;
2629 /*
2630 * A number must have some kind of delimiter after
2631 * it, and we can ignore that too.
2632 */
2633 continue;
2634 }
2635 if (isalpha(*ptr) || *ptr == '_') {
2636 if (strncmp(map->eval_string, ptr, len) == 0 &&
2637 !isalnum(ptr[len]) && ptr[len] != '_') {
2638 ptr = eval_replace(ptr, map, len);
2639 /* enum/sizeof string smaller than value */
2640 if (WARN_ON_ONCE(!ptr))
2641 return;
2642 /*
2643 * No need to decrement here, as eval_replace()
2644 * returns the pointer to the character passed
2645 * the eval, and two evals can not be placed
2646 * back to back without something in between.
2647 * We can skip that something in between.
2648 */
2649 continue;
2650 }
2651 skip_more:
2652 do {
2653 ptr++;
2654 } while (isalnum(*ptr) || *ptr == '_');
2655 if (!*ptr)
2656 break;
2657 /*
2658 * If what comes after this variable is a '.' or
2659 * '->' then we can continue to ignore that string.
2660 */
2661 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2662 ptr += *ptr == '.' ? 1 : 2;
2663 if (!*ptr)
2664 break;
2665 goto skip_more;
2666 }
2667 /*
2668 * Once again, we can skip the delimiter that came
2669 * after the string.
2670 */
2671 continue;
2672 }
2673 }
2674}
2675
2676static void add_str_to_module(struct module *module, char *str)
2677{
2678 struct module_string *modstr;
2679
2680 modstr = kmalloc(sizeof(*modstr), GFP_KERNEL);
2681
2682 /*
2683 * If we failed to allocate memory here, then we'll just
2684 * let the str memory leak when the module is removed.
2685 * If this fails to allocate, there's worse problems than
2686 * a leaked string on module removal.
2687 */
2688 if (WARN_ON_ONCE(!modstr))
2689 return;
2690
2691 modstr->module = module;
2692 modstr->str = str;
2693
2694 list_add(&modstr->next, &module_strings);
2695}
2696
2697static void update_event_fields(struct trace_event_call *call,
2698 struct trace_eval_map *map)
2699{
2700 struct ftrace_event_field *field;
2701 struct list_head *head;
2702 char *ptr;
2703 char *str;
2704 int len = strlen(map->eval_string);
2705
2706 /* Dynamic events should never have field maps */
2707 if (WARN_ON_ONCE(call->flags & TRACE_EVENT_FL_DYNAMIC))
2708 return;
2709
2710 head = trace_get_fields(call);
2711 list_for_each_entry(field, head, link) {
2712 ptr = strchr(field->type, '[');
2713 if (!ptr)
2714 continue;
2715 ptr++;
2716
2717 if (!isalpha(*ptr) && *ptr != '_')
2718 continue;
2719
2720 if (strncmp(map->eval_string, ptr, len) != 0)
2721 continue;
2722
2723 str = kstrdup(field->type, GFP_KERNEL);
2724 if (WARN_ON_ONCE(!str))
2725 return;
2726 ptr = str + (ptr - field->type);
2727 ptr = eval_replace(ptr, map, len);
2728 /* enum/sizeof string smaller than value */
2729 if (WARN_ON_ONCE(!ptr)) {
2730 kfree(str);
2731 continue;
2732 }
2733
2734 /*
2735 * If the event is part of a module, then we need to free the string
2736 * when the module is removed. Otherwise, it will stay allocated
2737 * until a reboot.
2738 */
2739 if (call->module)
2740 add_str_to_module(call->module, str);
2741
2742 field->type = str;
2743 }
2744}
2745
2746void trace_event_eval_update(struct trace_eval_map **map, int len)
2747{
2748 struct trace_event_call *call, *p;
2749 const char *last_system = NULL;
2750 bool first = false;
2751 int last_i;
2752 int i;
2753
2754 down_write(&trace_event_sem);
2755 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2756 /* events are usually grouped together with systems */
2757 if (!last_system || call->class->system != last_system) {
2758 first = true;
2759 last_i = 0;
2760 last_system = call->class->system;
2761 }
2762
2763 /*
2764 * Since calls are grouped by systems, the likelihood that the
2765 * next call in the iteration belongs to the same system as the
2766 * previous call is high. As an optimization, we skip searching
2767 * for a map[] that matches the call's system if the last call
2768 * was from the same system. That's what last_i is for. If the
2769 * call has the same system as the previous call, then last_i
2770 * will be the index of the first map[] that has a matching
2771 * system.
2772 */
2773 for (i = last_i; i < len; i++) {
2774 if (call->class->system == map[i]->system) {
2775 /* Save the first system if need be */
2776 if (first) {
2777 last_i = i;
2778 first = false;
2779 }
2780 update_event_printk(call, map[i]);
2781 update_event_fields(call, map[i]);
2782 }
2783 }
2784 }
2785 up_write(&trace_event_sem);
2786}
2787
2788static struct trace_event_file *
2789trace_create_new_event(struct trace_event_call *call,
2790 struct trace_array *tr)
2791{
2792 struct trace_pid_list *no_pid_list;
2793 struct trace_pid_list *pid_list;
2794 struct trace_event_file *file;
2795 unsigned int first;
2796
2797 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2798 if (!file)
2799 return NULL;
2800
2801 pid_list = rcu_dereference_protected(tr->filtered_pids,
2802 lockdep_is_held(&event_mutex));
2803 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
2804 lockdep_is_held(&event_mutex));
2805
2806 if (!trace_pid_list_first(pid_list, &first) ||
2807 !trace_pid_list_first(no_pid_list, &first))
2808 file->flags |= EVENT_FILE_FL_PID_FILTER;
2809
2810 file->event_call = call;
2811 file->tr = tr;
2812 atomic_set(&file->sm_ref, 0);
2813 atomic_set(&file->tm_ref, 0);
2814 INIT_LIST_HEAD(&file->triggers);
2815 list_add(&file->list, &tr->events);
2816
2817 return file;
2818}
2819
2820#define MAX_BOOT_TRIGGERS 32
2821
2822static struct boot_triggers {
2823 const char *event;
2824 char *trigger;
2825} bootup_triggers[MAX_BOOT_TRIGGERS];
2826
2827static char bootup_trigger_buf[COMMAND_LINE_SIZE];
2828static int nr_boot_triggers;
2829
2830static __init int setup_trace_triggers(char *str)
2831{
2832 char *trigger;
2833 char *buf;
2834 int i;
2835
2836 strlcpy(bootup_trigger_buf, str, COMMAND_LINE_SIZE);
2837 ring_buffer_expanded = true;
2838 disable_tracing_selftest("running event triggers");
2839
2840 buf = bootup_trigger_buf;
2841 for (i = 0; i < MAX_BOOT_TRIGGERS; i++) {
2842 trigger = strsep(&buf, ",");
2843 if (!trigger)
2844 break;
2845 bootup_triggers[i].event = strsep(&trigger, ".");
2846 bootup_triggers[i].trigger = strsep(&trigger, ".");
2847 if (!bootup_triggers[i].trigger)
2848 break;
2849 }
2850
2851 nr_boot_triggers = i;
2852 return 1;
2853}
2854__setup("trace_trigger=", setup_trace_triggers);
2855
2856/* Add an event to a trace directory */
2857static int
2858__trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2859{
2860 struct trace_event_file *file;
2861
2862 file = trace_create_new_event(call, tr);
2863 if (!file)
2864 return -ENOMEM;
2865
2866 if (eventdir_initialized)
2867 return event_create_dir(tr->event_dir, file);
2868 else
2869 return event_define_fields(call);
2870}
2871
2872static void trace_early_triggers(struct trace_event_file *file, const char *name)
2873{
2874 int ret;
2875 int i;
2876
2877 for (i = 0; i < nr_boot_triggers; i++) {
2878 if (strcmp(name, bootup_triggers[i].event))
2879 continue;
2880 mutex_lock(&event_mutex);
2881 ret = trigger_process_regex(file, bootup_triggers[i].trigger);
2882 mutex_unlock(&event_mutex);
2883 if (ret)
2884 pr_err("Failed to register trigger '%s' on event %s\n",
2885 bootup_triggers[i].trigger,
2886 bootup_triggers[i].event);
2887 }
2888}
2889
2890/*
2891 * Just create a descriptor for early init. A descriptor is required
2892 * for enabling events at boot. We want to enable events before
2893 * the filesystem is initialized.
2894 */
2895static int
2896__trace_early_add_new_event(struct trace_event_call *call,
2897 struct trace_array *tr)
2898{
2899 struct trace_event_file *file;
2900 int ret;
2901
2902 file = trace_create_new_event(call, tr);
2903 if (!file)
2904 return -ENOMEM;
2905
2906 ret = event_define_fields(call);
2907 if (ret)
2908 return ret;
2909
2910 trace_early_triggers(file, trace_event_name(call));
2911
2912 return 0;
2913}
2914
2915struct ftrace_module_file_ops;
2916static void __add_event_to_tracers(struct trace_event_call *call);
2917
2918/* Add an additional event_call dynamically */
2919int trace_add_event_call(struct trace_event_call *call)
2920{
2921 int ret;
2922 lockdep_assert_held(&event_mutex);
2923
2924 mutex_lock(&trace_types_lock);
2925
2926 ret = __register_event(call, NULL);
2927 if (ret >= 0)
2928 __add_event_to_tracers(call);
2929
2930 mutex_unlock(&trace_types_lock);
2931 return ret;
2932}
2933EXPORT_SYMBOL_GPL(trace_add_event_call);
2934
2935/*
2936 * Must be called under locking of trace_types_lock, event_mutex and
2937 * trace_event_sem.
2938 */
2939static void __trace_remove_event_call(struct trace_event_call *call)
2940{
2941 event_remove(call);
2942 trace_destroy_fields(call);
2943 free_event_filter(call->filter);
2944 call->filter = NULL;
2945}
2946
2947static int probe_remove_event_call(struct trace_event_call *call)
2948{
2949 struct trace_array *tr;
2950 struct trace_event_file *file;
2951
2952#ifdef CONFIG_PERF_EVENTS
2953 if (call->perf_refcount)
2954 return -EBUSY;
2955#endif
2956 do_for_each_event_file(tr, file) {
2957 if (file->event_call != call)
2958 continue;
2959 /*
2960 * We can't rely on ftrace_event_enable_disable(enable => 0)
2961 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2962 * TRACE_REG_UNREGISTER.
2963 */
2964 if (file->flags & EVENT_FILE_FL_ENABLED)
2965 goto busy;
2966
2967 if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
2968 tr->clear_trace = true;
2969 /*
2970 * The do_for_each_event_file_safe() is
2971 * a double loop. After finding the call for this
2972 * trace_array, we use break to jump to the next
2973 * trace_array.
2974 */
2975 break;
2976 } while_for_each_event_file();
2977
2978 __trace_remove_event_call(call);
2979
2980 return 0;
2981 busy:
2982 /* No need to clear the trace now */
2983 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
2984 tr->clear_trace = false;
2985 }
2986 return -EBUSY;
2987}
2988
2989/* Remove an event_call */
2990int trace_remove_event_call(struct trace_event_call *call)
2991{
2992 int ret;
2993
2994 lockdep_assert_held(&event_mutex);
2995
2996 mutex_lock(&trace_types_lock);
2997 down_write(&trace_event_sem);
2998 ret = probe_remove_event_call(call);
2999 up_write(&trace_event_sem);
3000 mutex_unlock(&trace_types_lock);
3001
3002 return ret;
3003}
3004EXPORT_SYMBOL_GPL(trace_remove_event_call);
3005
3006#define for_each_event(event, start, end) \
3007 for (event = start; \
3008 (unsigned long)event < (unsigned long)end; \
3009 event++)
3010
3011#ifdef CONFIG_MODULES
3012
3013static void trace_module_add_events(struct module *mod)
3014{
3015 struct trace_event_call **call, **start, **end;
3016
3017 if (!mod->num_trace_events)
3018 return;
3019
3020 /* Don't add infrastructure for mods without tracepoints */
3021 if (trace_module_has_bad_taint(mod)) {
3022 pr_err("%s: module has bad taint, not creating trace events\n",
3023 mod->name);
3024 return;
3025 }
3026
3027 start = mod->trace_events;
3028 end = mod->trace_events + mod->num_trace_events;
3029
3030 for_each_event(call, start, end) {
3031 __register_event(*call, mod);
3032 __add_event_to_tracers(*call);
3033 }
3034}
3035
3036static void trace_module_remove_events(struct module *mod)
3037{
3038 struct trace_event_call *call, *p;
3039 struct module_string *modstr, *m;
3040
3041 down_write(&trace_event_sem);
3042 list_for_each_entry_safe(call, p, &ftrace_events, list) {
3043 if ((call->flags & TRACE_EVENT_FL_DYNAMIC) || !call->module)
3044 continue;
3045 if (call->module == mod)
3046 __trace_remove_event_call(call);
3047 }
3048 /* Check for any strings allocade for this module */
3049 list_for_each_entry_safe(modstr, m, &module_strings, next) {
3050 if (modstr->module != mod)
3051 continue;
3052 list_del(&modstr->next);
3053 kfree(modstr->str);
3054 kfree(modstr);
3055 }
3056 up_write(&trace_event_sem);
3057
3058 /*
3059 * It is safest to reset the ring buffer if the module being unloaded
3060 * registered any events that were used. The only worry is if
3061 * a new module gets loaded, and takes on the same id as the events
3062 * of this module. When printing out the buffer, traced events left
3063 * over from this module may be passed to the new module events and
3064 * unexpected results may occur.
3065 */
3066 tracing_reset_all_online_cpus_unlocked();
3067}
3068
3069static int trace_module_notify(struct notifier_block *self,
3070 unsigned long val, void *data)
3071{
3072 struct module *mod = data;
3073
3074 mutex_lock(&event_mutex);
3075 mutex_lock(&trace_types_lock);
3076 switch (val) {
3077 case MODULE_STATE_COMING:
3078 trace_module_add_events(mod);
3079 break;
3080 case MODULE_STATE_GOING:
3081 trace_module_remove_events(mod);
3082 break;
3083 }
3084 mutex_unlock(&trace_types_lock);
3085 mutex_unlock(&event_mutex);
3086
3087 return NOTIFY_OK;
3088}
3089
3090static struct notifier_block trace_module_nb = {
3091 .notifier_call = trace_module_notify,
3092 .priority = 1, /* higher than trace.c module notify */
3093};
3094#endif /* CONFIG_MODULES */
3095
3096/* Create a new event directory structure for a trace directory. */
3097static void
3098__trace_add_event_dirs(struct trace_array *tr)
3099{
3100 struct trace_event_call *call;
3101 int ret;
3102
3103 list_for_each_entry(call, &ftrace_events, list) {
3104 ret = __trace_add_new_event(call, tr);
3105 if (ret < 0)
3106 pr_warn("Could not create directory for event %s\n",
3107 trace_event_name(call));
3108 }
3109}
3110
3111/* Returns any file that matches the system and event */
3112struct trace_event_file *
3113__find_event_file(struct trace_array *tr, const char *system, const char *event)
3114{
3115 struct trace_event_file *file;
3116 struct trace_event_call *call;
3117 const char *name;
3118
3119 list_for_each_entry(file, &tr->events, list) {
3120
3121 call = file->event_call;
3122 name = trace_event_name(call);
3123
3124 if (!name || !call->class)
3125 continue;
3126
3127 if (strcmp(event, name) == 0 &&
3128 strcmp(system, call->class->system) == 0)
3129 return file;
3130 }
3131 return NULL;
3132}
3133
3134/* Returns valid trace event files that match system and event */
3135struct trace_event_file *
3136find_event_file(struct trace_array *tr, const char *system, const char *event)
3137{
3138 struct trace_event_file *file;
3139
3140 file = __find_event_file(tr, system, event);
3141 if (!file || !file->event_call->class->reg ||
3142 file->event_call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
3143 return NULL;
3144
3145 return file;
3146}
3147
3148/**
3149 * trace_get_event_file - Find and return a trace event file
3150 * @instance: The name of the trace instance containing the event
3151 * @system: The name of the system containing the event
3152 * @event: The name of the event
3153 *
3154 * Return a trace event file given the trace instance name, trace
3155 * system, and trace event name. If the instance name is NULL, it
3156 * refers to the top-level trace array.
3157 *
3158 * This function will look it up and return it if found, after calling
3159 * trace_array_get() to prevent the instance from going away, and
3160 * increment the event's module refcount to prevent it from being
3161 * removed.
3162 *
3163 * To release the file, call trace_put_event_file(), which will call
3164 * trace_array_put() and decrement the event's module refcount.
3165 *
3166 * Return: The trace event on success, ERR_PTR otherwise.
3167 */
3168struct trace_event_file *trace_get_event_file(const char *instance,
3169 const char *system,
3170 const char *event)
3171{
3172 struct trace_array *tr = top_trace_array();
3173 struct trace_event_file *file = NULL;
3174 int ret = -EINVAL;
3175
3176 if (instance) {
3177 tr = trace_array_find_get(instance);
3178 if (!tr)
3179 return ERR_PTR(-ENOENT);
3180 } else {
3181 ret = trace_array_get(tr);
3182 if (ret)
3183 return ERR_PTR(ret);
3184 }
3185
3186 mutex_lock(&event_mutex);
3187
3188 file = find_event_file(tr, system, event);
3189 if (!file) {
3190 trace_array_put(tr);
3191 ret = -EINVAL;
3192 goto out;
3193 }
3194
3195 /* Don't let event modules unload while in use */
3196 ret = trace_event_try_get_ref(file->event_call);
3197 if (!ret) {
3198 trace_array_put(tr);
3199 ret = -EBUSY;
3200 goto out;
3201 }
3202
3203 ret = 0;
3204 out:
3205 mutex_unlock(&event_mutex);
3206
3207 if (ret)
3208 file = ERR_PTR(ret);
3209
3210 return file;
3211}
3212EXPORT_SYMBOL_GPL(trace_get_event_file);
3213
3214/**
3215 * trace_put_event_file - Release a file from trace_get_event_file()
3216 * @file: The trace event file
3217 *
3218 * If a file was retrieved using trace_get_event_file(), this should
3219 * be called when it's no longer needed. It will cancel the previous
3220 * trace_array_get() called by that function, and decrement the
3221 * event's module refcount.
3222 */
3223void trace_put_event_file(struct trace_event_file *file)
3224{
3225 mutex_lock(&event_mutex);
3226 trace_event_put_ref(file->event_call);
3227 mutex_unlock(&event_mutex);
3228
3229 trace_array_put(file->tr);
3230}
3231EXPORT_SYMBOL_GPL(trace_put_event_file);
3232
3233#ifdef CONFIG_DYNAMIC_FTRACE
3234
3235/* Avoid typos */
3236#define ENABLE_EVENT_STR "enable_event"
3237#define DISABLE_EVENT_STR "disable_event"
3238
3239struct event_probe_data {
3240 struct trace_event_file *file;
3241 unsigned long count;
3242 int ref;
3243 bool enable;
3244};
3245
3246static void update_event_probe(struct event_probe_data *data)
3247{
3248 if (data->enable)
3249 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
3250 else
3251 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
3252}
3253
3254static void
3255event_enable_probe(unsigned long ip, unsigned long parent_ip,
3256 struct trace_array *tr, struct ftrace_probe_ops *ops,
3257 void *data)
3258{
3259 struct ftrace_func_mapper *mapper = data;
3260 struct event_probe_data *edata;
3261 void **pdata;
3262
3263 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3264 if (!pdata || !*pdata)
3265 return;
3266
3267 edata = *pdata;
3268 update_event_probe(edata);
3269}
3270
3271static void
3272event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
3273 struct trace_array *tr, struct ftrace_probe_ops *ops,
3274 void *data)
3275{
3276 struct ftrace_func_mapper *mapper = data;
3277 struct event_probe_data *edata;
3278 void **pdata;
3279
3280 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3281 if (!pdata || !*pdata)
3282 return;
3283
3284 edata = *pdata;
3285
3286 if (!edata->count)
3287 return;
3288
3289 /* Skip if the event is in a state we want to switch to */
3290 if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
3291 return;
3292
3293 if (edata->count != -1)
3294 (edata->count)--;
3295
3296 update_event_probe(edata);
3297}
3298
3299static int
3300event_enable_print(struct seq_file *m, unsigned long ip,
3301 struct ftrace_probe_ops *ops, void *data)
3302{
3303 struct ftrace_func_mapper *mapper = data;
3304 struct event_probe_data *edata;
3305 void **pdata;
3306
3307 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3308
3309 if (WARN_ON_ONCE(!pdata || !*pdata))
3310 return 0;
3311
3312 edata = *pdata;
3313
3314 seq_printf(m, "%ps:", (void *)ip);
3315
3316 seq_printf(m, "%s:%s:%s",
3317 edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
3318 edata->file->event_call->class->system,
3319 trace_event_name(edata->file->event_call));
3320
3321 if (edata->count == -1)
3322 seq_puts(m, ":unlimited\n");
3323 else
3324 seq_printf(m, ":count=%ld\n", edata->count);
3325
3326 return 0;
3327}
3328
3329static int
3330event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
3331 unsigned long ip, void *init_data, void **data)
3332{
3333 struct ftrace_func_mapper *mapper = *data;
3334 struct event_probe_data *edata = init_data;
3335 int ret;
3336
3337 if (!mapper) {
3338 mapper = allocate_ftrace_func_mapper();
3339 if (!mapper)
3340 return -ENODEV;
3341 *data = mapper;
3342 }
3343
3344 ret = ftrace_func_mapper_add_ip(mapper, ip, edata);
3345 if (ret < 0)
3346 return ret;
3347
3348 edata->ref++;
3349
3350 return 0;
3351}
3352
3353static int free_probe_data(void *data)
3354{
3355 struct event_probe_data *edata = data;
3356
3357 edata->ref--;
3358 if (!edata->ref) {
3359 /* Remove the SOFT_MODE flag */
3360 __ftrace_event_enable_disable(edata->file, 0, 1);
3361 trace_event_put_ref(edata->file->event_call);
3362 kfree(edata);
3363 }
3364 return 0;
3365}
3366
3367static void
3368event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
3369 unsigned long ip, void *data)
3370{
3371 struct ftrace_func_mapper *mapper = data;
3372 struct event_probe_data *edata;
3373
3374 if (!ip) {
3375 if (!mapper)
3376 return;
3377 free_ftrace_func_mapper(mapper, free_probe_data);
3378 return;
3379 }
3380
3381 edata = ftrace_func_mapper_remove_ip(mapper, ip);
3382
3383 if (WARN_ON_ONCE(!edata))
3384 return;
3385
3386 if (WARN_ON_ONCE(edata->ref <= 0))
3387 return;
3388
3389 free_probe_data(edata);
3390}
3391
3392static struct ftrace_probe_ops event_enable_probe_ops = {
3393 .func = event_enable_probe,
3394 .print = event_enable_print,
3395 .init = event_enable_init,
3396 .free = event_enable_free,
3397};
3398
3399static struct ftrace_probe_ops event_enable_count_probe_ops = {
3400 .func = event_enable_count_probe,
3401 .print = event_enable_print,
3402 .init = event_enable_init,
3403 .free = event_enable_free,
3404};
3405
3406static struct ftrace_probe_ops event_disable_probe_ops = {
3407 .func = event_enable_probe,
3408 .print = event_enable_print,
3409 .init = event_enable_init,
3410 .free = event_enable_free,
3411};
3412
3413static struct ftrace_probe_ops event_disable_count_probe_ops = {
3414 .func = event_enable_count_probe,
3415 .print = event_enable_print,
3416 .init = event_enable_init,
3417 .free = event_enable_free,
3418};
3419
3420static int
3421event_enable_func(struct trace_array *tr, struct ftrace_hash *hash,
3422 char *glob, char *cmd, char *param, int enabled)
3423{
3424 struct trace_event_file *file;
3425 struct ftrace_probe_ops *ops;
3426 struct event_probe_data *data;
3427 const char *system;
3428 const char *event;
3429 char *number;
3430 bool enable;
3431 int ret;
3432
3433 if (!tr)
3434 return -ENODEV;
3435
3436 /* hash funcs only work with set_ftrace_filter */
3437 if (!enabled || !param)
3438 return -EINVAL;
3439
3440 system = strsep(¶m, ":");
3441 if (!param)
3442 return -EINVAL;
3443
3444 event = strsep(¶m, ":");
3445
3446 mutex_lock(&event_mutex);
3447
3448 ret = -EINVAL;
3449 file = find_event_file(tr, system, event);
3450 if (!file)
3451 goto out;
3452
3453 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
3454
3455 if (enable)
3456 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
3457 else
3458 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
3459
3460 if (glob[0] == '!') {
3461 ret = unregister_ftrace_function_probe_func(glob+1, tr, ops);
3462 goto out;
3463 }
3464
3465 ret = -ENOMEM;
3466
3467 data = kzalloc(sizeof(*data), GFP_KERNEL);
3468 if (!data)
3469 goto out;
3470
3471 data->enable = enable;
3472 data->count = -1;
3473 data->file = file;
3474
3475 if (!param)
3476 goto out_reg;
3477
3478 number = strsep(¶m, ":");
3479
3480 ret = -EINVAL;
3481 if (!strlen(number))
3482 goto out_free;
3483
3484 /*
3485 * We use the callback data field (which is a pointer)
3486 * as our counter.
3487 */
3488 ret = kstrtoul(number, 0, &data->count);
3489 if (ret)
3490 goto out_free;
3491
3492 out_reg:
3493 /* Don't let event modules unload while probe registered */
3494 ret = trace_event_try_get_ref(file->event_call);
3495 if (!ret) {
3496 ret = -EBUSY;
3497 goto out_free;
3498 }
3499
3500 ret = __ftrace_event_enable_disable(file, 1, 1);
3501 if (ret < 0)
3502 goto out_put;
3503
3504 ret = register_ftrace_function_probe(glob, tr, ops, data);
3505 /*
3506 * The above returns on success the # of functions enabled,
3507 * but if it didn't find any functions it returns zero.
3508 * Consider no functions a failure too.
3509 */
3510 if (!ret) {
3511 ret = -ENOENT;
3512 goto out_disable;
3513 } else if (ret < 0)
3514 goto out_disable;
3515 /* Just return zero, not the number of enabled functions */
3516 ret = 0;
3517 out:
3518 mutex_unlock(&event_mutex);
3519 return ret;
3520
3521 out_disable:
3522 __ftrace_event_enable_disable(file, 0, 1);
3523 out_put:
3524 trace_event_put_ref(file->event_call);
3525 out_free:
3526 kfree(data);
3527 goto out;
3528}
3529
3530static struct ftrace_func_command event_enable_cmd = {
3531 .name = ENABLE_EVENT_STR,
3532 .func = event_enable_func,
3533};
3534
3535static struct ftrace_func_command event_disable_cmd = {
3536 .name = DISABLE_EVENT_STR,
3537 .func = event_enable_func,
3538};
3539
3540static __init int register_event_cmds(void)
3541{
3542 int ret;
3543
3544 ret = register_ftrace_command(&event_enable_cmd);
3545 if (WARN_ON(ret < 0))
3546 return ret;
3547 ret = register_ftrace_command(&event_disable_cmd);
3548 if (WARN_ON(ret < 0))
3549 unregister_ftrace_command(&event_enable_cmd);
3550 return ret;
3551}
3552#else
3553static inline int register_event_cmds(void) { return 0; }
3554#endif /* CONFIG_DYNAMIC_FTRACE */
3555
3556/*
3557 * The top level array and trace arrays created by boot-time tracing
3558 * have already had its trace_event_file descriptors created in order
3559 * to allow for early events to be recorded.
3560 * This function is called after the tracefs has been initialized,
3561 * and we now have to create the files associated to the events.
3562 */
3563static void __trace_early_add_event_dirs(struct trace_array *tr)
3564{
3565 struct trace_event_file *file;
3566 int ret;
3567
3568
3569 list_for_each_entry(file, &tr->events, list) {
3570 ret = event_create_dir(tr->event_dir, file);
3571 if (ret < 0)
3572 pr_warn("Could not create directory for event %s\n",
3573 trace_event_name(file->event_call));
3574 }
3575}
3576
3577/*
3578 * For early boot up, the top trace array and the trace arrays created
3579 * by boot-time tracing require to have a list of events that can be
3580 * enabled. This must be done before the filesystem is set up in order
3581 * to allow events to be traced early.
3582 */
3583void __trace_early_add_events(struct trace_array *tr)
3584{
3585 struct trace_event_call *call;
3586 int ret;
3587
3588 list_for_each_entry(call, &ftrace_events, list) {
3589 /* Early boot up should not have any modules loaded */
3590 if (!(call->flags & TRACE_EVENT_FL_DYNAMIC) &&
3591 WARN_ON_ONCE(call->module))
3592 continue;
3593
3594 ret = __trace_early_add_new_event(call, tr);
3595 if (ret < 0)
3596 pr_warn("Could not create early event %s\n",
3597 trace_event_name(call));
3598 }
3599}
3600
3601/* Remove the event directory structure for a trace directory. */
3602static void
3603__trace_remove_event_dirs(struct trace_array *tr)
3604{
3605 struct trace_event_file *file, *next;
3606
3607 list_for_each_entry_safe(file, next, &tr->events, list)
3608 remove_event_file_dir(file);
3609}
3610
3611static void __add_event_to_tracers(struct trace_event_call *call)
3612{
3613 struct trace_array *tr;
3614
3615 list_for_each_entry(tr, &ftrace_trace_arrays, list)
3616 __trace_add_new_event(call, tr);
3617}
3618
3619extern struct trace_event_call *__start_ftrace_events[];
3620extern struct trace_event_call *__stop_ftrace_events[];
3621
3622static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
3623
3624static __init int setup_trace_event(char *str)
3625{
3626 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
3627 ring_buffer_expanded = true;
3628 disable_tracing_selftest("running event tracing");
3629
3630 return 1;
3631}
3632__setup("trace_event=", setup_trace_event);
3633
3634/* Expects to have event_mutex held when called */
3635static int
3636create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
3637{
3638 struct dentry *d_events;
3639 struct dentry *entry;
3640
3641 entry = trace_create_file("set_event", TRACE_MODE_WRITE, parent,
3642 tr, &ftrace_set_event_fops);
3643 if (!entry)
3644 return -ENOMEM;
3645
3646 d_events = tracefs_create_dir("events", parent);
3647 if (!d_events) {
3648 pr_warn("Could not create tracefs 'events' directory\n");
3649 return -ENOMEM;
3650 }
3651
3652 entry = trace_create_file("enable", TRACE_MODE_WRITE, d_events,
3653 tr, &ftrace_tr_enable_fops);
3654 if (!entry)
3655 return -ENOMEM;
3656
3657 /* There are not as crucial, just warn if they are not created */
3658
3659 trace_create_file("set_event_pid", TRACE_MODE_WRITE, parent,
3660 tr, &ftrace_set_event_pid_fops);
3661
3662 trace_create_file("set_event_notrace_pid",
3663 TRACE_MODE_WRITE, parent, tr,
3664 &ftrace_set_event_notrace_pid_fops);
3665
3666 /* ring buffer internal formats */
3667 trace_create_file("header_page", TRACE_MODE_READ, d_events,
3668 ring_buffer_print_page_header,
3669 &ftrace_show_header_fops);
3670
3671 trace_create_file("header_event", TRACE_MODE_READ, d_events,
3672 ring_buffer_print_entry_header,
3673 &ftrace_show_header_fops);
3674
3675 tr->event_dir = d_events;
3676
3677 return 0;
3678}
3679
3680/**
3681 * event_trace_add_tracer - add a instance of a trace_array to events
3682 * @parent: The parent dentry to place the files/directories for events in
3683 * @tr: The trace array associated with these events
3684 *
3685 * When a new instance is created, it needs to set up its events
3686 * directory, as well as other files associated with events. It also
3687 * creates the event hierarchy in the @parent/events directory.
3688 *
3689 * Returns 0 on success.
3690 *
3691 * Must be called with event_mutex held.
3692 */
3693int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
3694{
3695 int ret;
3696
3697 lockdep_assert_held(&event_mutex);
3698
3699 ret = create_event_toplevel_files(parent, tr);
3700 if (ret)
3701 goto out;
3702
3703 down_write(&trace_event_sem);
3704 /* If tr already has the event list, it is initialized in early boot. */
3705 if (unlikely(!list_empty(&tr->events)))
3706 __trace_early_add_event_dirs(tr);
3707 else
3708 __trace_add_event_dirs(tr);
3709 up_write(&trace_event_sem);
3710
3711 out:
3712 return ret;
3713}
3714
3715/*
3716 * The top trace array already had its file descriptors created.
3717 * Now the files themselves need to be created.
3718 */
3719static __init int
3720early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
3721{
3722 int ret;
3723
3724 mutex_lock(&event_mutex);
3725
3726 ret = create_event_toplevel_files(parent, tr);
3727 if (ret)
3728 goto out_unlock;
3729
3730 down_write(&trace_event_sem);
3731 __trace_early_add_event_dirs(tr);
3732 up_write(&trace_event_sem);
3733
3734 out_unlock:
3735 mutex_unlock(&event_mutex);
3736
3737 return ret;
3738}
3739
3740/* Must be called with event_mutex held */
3741int event_trace_del_tracer(struct trace_array *tr)
3742{
3743 lockdep_assert_held(&event_mutex);
3744
3745 /* Disable any event triggers and associated soft-disabled events */
3746 clear_event_triggers(tr);
3747
3748 /* Clear the pid list */
3749 __ftrace_clear_event_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
3750
3751 /* Disable any running events */
3752 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3753
3754 /* Make sure no more events are being executed */
3755 tracepoint_synchronize_unregister();
3756
3757 down_write(&trace_event_sem);
3758 __trace_remove_event_dirs(tr);
3759 tracefs_remove(tr->event_dir);
3760 up_write(&trace_event_sem);
3761
3762 tr->event_dir = NULL;
3763
3764 return 0;
3765}
3766
3767static __init int event_trace_memsetup(void)
3768{
3769 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3770 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3771 return 0;
3772}
3773
3774static __init void
3775early_enable_events(struct trace_array *tr, bool disable_first)
3776{
3777 char *buf = bootup_event_buf;
3778 char *token;
3779 int ret;
3780
3781 while (true) {
3782 token = strsep(&buf, ",");
3783
3784 if (!token)
3785 break;
3786
3787 if (*token) {
3788 /* Restarting syscalls requires that we stop them first */
3789 if (disable_first)
3790 ftrace_set_clr_event(tr, token, 0);
3791
3792 ret = ftrace_set_clr_event(tr, token, 1);
3793 if (ret)
3794 pr_warn("Failed to enable trace event: %s\n", token);
3795 }
3796
3797 /* Put back the comma to allow this to be called again */
3798 if (buf)
3799 *(buf - 1) = ',';
3800 }
3801}
3802
3803static __init int event_trace_enable(void)
3804{
3805 struct trace_array *tr = top_trace_array();
3806 struct trace_event_call **iter, *call;
3807 int ret;
3808
3809 if (!tr)
3810 return -ENODEV;
3811
3812 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3813
3814 call = *iter;
3815 ret = event_init(call);
3816 if (!ret)
3817 list_add(&call->list, &ftrace_events);
3818 }
3819
3820 register_trigger_cmds();
3821
3822 /*
3823 * We need the top trace array to have a working set of trace
3824 * points at early init, before the debug files and directories
3825 * are created. Create the file entries now, and attach them
3826 * to the actual file dentries later.
3827 */
3828 __trace_early_add_events(tr);
3829
3830 early_enable_events(tr, false);
3831
3832 trace_printk_start_comm();
3833
3834 register_event_cmds();
3835
3836
3837 return 0;
3838}
3839
3840/*
3841 * event_trace_enable() is called from trace_event_init() first to
3842 * initialize events and perhaps start any events that are on the
3843 * command line. Unfortunately, there are some events that will not
3844 * start this early, like the system call tracepoints that need
3845 * to set the %SYSCALL_WORK_SYSCALL_TRACEPOINT flag of pid 1. But
3846 * event_trace_enable() is called before pid 1 starts, and this flag
3847 * is never set, making the syscall tracepoint never get reached, but
3848 * the event is enabled regardless (and not doing anything).
3849 */
3850static __init int event_trace_enable_again(void)
3851{
3852 struct trace_array *tr;
3853
3854 tr = top_trace_array();
3855 if (!tr)
3856 return -ENODEV;
3857
3858 early_enable_events(tr, true);
3859
3860 return 0;
3861}
3862
3863early_initcall(event_trace_enable_again);
3864
3865/* Init fields which doesn't related to the tracefs */
3866static __init int event_trace_init_fields(void)
3867{
3868 if (trace_define_generic_fields())
3869 pr_warn("tracing: Failed to allocated generic fields");
3870
3871 if (trace_define_common_fields())
3872 pr_warn("tracing: Failed to allocate common fields");
3873
3874 return 0;
3875}
3876
3877__init int event_trace_init(void)
3878{
3879 struct trace_array *tr;
3880 int ret;
3881
3882 tr = top_trace_array();
3883 if (!tr)
3884 return -ENODEV;
3885
3886 trace_create_file("available_events", TRACE_MODE_READ,
3887 NULL, tr, &ftrace_avail_fops);
3888
3889 ret = early_event_add_tracer(NULL, tr);
3890 if (ret)
3891 return ret;
3892
3893#ifdef CONFIG_MODULES
3894 ret = register_module_notifier(&trace_module_nb);
3895 if (ret)
3896 pr_warn("Failed to register trace events module notifier\n");
3897#endif
3898
3899 eventdir_initialized = true;
3900
3901 return 0;
3902}
3903
3904void __init trace_event_init(void)
3905{
3906 event_trace_memsetup();
3907 init_ftrace_syscalls();
3908 event_trace_enable();
3909 event_trace_init_fields();
3910}
3911
3912#ifdef CONFIG_EVENT_TRACE_STARTUP_TEST
3913
3914static DEFINE_SPINLOCK(test_spinlock);
3915static DEFINE_SPINLOCK(test_spinlock_irq);
3916static DEFINE_MUTEX(test_mutex);
3917
3918static __init void test_work(struct work_struct *dummy)
3919{
3920 spin_lock(&test_spinlock);
3921 spin_lock_irq(&test_spinlock_irq);
3922 udelay(1);
3923 spin_unlock_irq(&test_spinlock_irq);
3924 spin_unlock(&test_spinlock);
3925
3926 mutex_lock(&test_mutex);
3927 msleep(1);
3928 mutex_unlock(&test_mutex);
3929}
3930
3931static __init int event_test_thread(void *unused)
3932{
3933 void *test_malloc;
3934
3935 test_malloc = kmalloc(1234, GFP_KERNEL);
3936 if (!test_malloc)
3937 pr_info("failed to kmalloc\n");
3938
3939 schedule_on_each_cpu(test_work);
3940
3941 kfree(test_malloc);
3942
3943 set_current_state(TASK_INTERRUPTIBLE);
3944 while (!kthread_should_stop()) {
3945 schedule();
3946 set_current_state(TASK_INTERRUPTIBLE);
3947 }
3948 __set_current_state(TASK_RUNNING);
3949
3950 return 0;
3951}
3952
3953/*
3954 * Do various things that may trigger events.
3955 */
3956static __init void event_test_stuff(void)
3957{
3958 struct task_struct *test_thread;
3959
3960 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3961 msleep(1);
3962 kthread_stop(test_thread);
3963}
3964
3965/*
3966 * For every trace event defined, we will test each trace point separately,
3967 * and then by groups, and finally all trace points.
3968 */
3969static __init void event_trace_self_tests(void)
3970{
3971 struct trace_subsystem_dir *dir;
3972 struct trace_event_file *file;
3973 struct trace_event_call *call;
3974 struct event_subsystem *system;
3975 struct trace_array *tr;
3976 int ret;
3977
3978 tr = top_trace_array();
3979 if (!tr)
3980 return;
3981
3982 pr_info("Running tests on trace events:\n");
3983
3984 list_for_each_entry(file, &tr->events, list) {
3985
3986 call = file->event_call;
3987
3988 /* Only test those that have a probe */
3989 if (!call->class || !call->class->probe)
3990 continue;
3991
3992/*
3993 * Testing syscall events here is pretty useless, but
3994 * we still do it if configured. But this is time consuming.
3995 * What we really need is a user thread to perform the
3996 * syscalls as we test.
3997 */
3998#ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3999 if (call->class->system &&
4000 strcmp(call->class->system, "syscalls") == 0)
4001 continue;
4002#endif
4003
4004 pr_info("Testing event %s: ", trace_event_name(call));
4005
4006 /*
4007 * If an event is already enabled, someone is using
4008 * it and the self test should not be on.
4009 */
4010 if (file->flags & EVENT_FILE_FL_ENABLED) {
4011 pr_warn("Enabled event during self test!\n");
4012 WARN_ON_ONCE(1);
4013 continue;
4014 }
4015
4016 ftrace_event_enable_disable(file, 1);
4017 event_test_stuff();
4018 ftrace_event_enable_disable(file, 0);
4019
4020 pr_cont("OK\n");
4021 }
4022
4023 /* Now test at the sub system level */
4024
4025 pr_info("Running tests on trace event systems:\n");
4026
4027 list_for_each_entry(dir, &tr->systems, list) {
4028
4029 system = dir->subsystem;
4030
4031 /* the ftrace system is special, skip it */
4032 if (strcmp(system->name, "ftrace") == 0)
4033 continue;
4034
4035 pr_info("Testing event system %s: ", system->name);
4036
4037 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
4038 if (WARN_ON_ONCE(ret)) {
4039 pr_warn("error enabling system %s\n",
4040 system->name);
4041 continue;
4042 }
4043
4044 event_test_stuff();
4045
4046 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
4047 if (WARN_ON_ONCE(ret)) {
4048 pr_warn("error disabling system %s\n",
4049 system->name);
4050 continue;
4051 }
4052
4053 pr_cont("OK\n");
4054 }
4055
4056 /* Test with all events enabled */
4057
4058 pr_info("Running tests on all trace events:\n");
4059 pr_info("Testing all events: ");
4060
4061 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
4062 if (WARN_ON_ONCE(ret)) {
4063 pr_warn("error enabling all events\n");
4064 return;
4065 }
4066
4067 event_test_stuff();
4068
4069 /* reset sysname */
4070 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
4071 if (WARN_ON_ONCE(ret)) {
4072 pr_warn("error disabling all events\n");
4073 return;
4074 }
4075
4076 pr_cont("OK\n");
4077}
4078
4079#ifdef CONFIG_FUNCTION_TRACER
4080
4081static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
4082
4083static struct trace_event_file event_trace_file __initdata;
4084
4085static void __init
4086function_test_events_call(unsigned long ip, unsigned long parent_ip,
4087 struct ftrace_ops *op, struct ftrace_regs *regs)
4088{
4089 struct trace_buffer *buffer;
4090 struct ring_buffer_event *event;
4091 struct ftrace_entry *entry;
4092 unsigned int trace_ctx;
4093 long disabled;
4094 int cpu;
4095
4096 trace_ctx = tracing_gen_ctx();
4097 preempt_disable_notrace();
4098 cpu = raw_smp_processor_id();
4099 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
4100
4101 if (disabled != 1)
4102 goto out;
4103
4104 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
4105 TRACE_FN, sizeof(*entry),
4106 trace_ctx);
4107 if (!event)
4108 goto out;
4109 entry = ring_buffer_event_data(event);
4110 entry->ip = ip;
4111 entry->parent_ip = parent_ip;
4112
4113 event_trigger_unlock_commit(&event_trace_file, buffer, event,
4114 entry, trace_ctx);
4115 out:
4116 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
4117 preempt_enable_notrace();
4118}
4119
4120static struct ftrace_ops trace_ops __initdata =
4121{
4122 .func = function_test_events_call,
4123};
4124
4125static __init void event_trace_self_test_with_function(void)
4126{
4127 int ret;
4128
4129 event_trace_file.tr = top_trace_array();
4130 if (WARN_ON(!event_trace_file.tr))
4131 return;
4132
4133 ret = register_ftrace_function(&trace_ops);
4134 if (WARN_ON(ret < 0)) {
4135 pr_info("Failed to enable function tracer for event tests\n");
4136 return;
4137 }
4138 pr_info("Running tests again, along with the function tracer\n");
4139 event_trace_self_tests();
4140 unregister_ftrace_function(&trace_ops);
4141}
4142#else
4143static __init void event_trace_self_test_with_function(void)
4144{
4145}
4146#endif
4147
4148static __init int event_trace_self_tests_init(void)
4149{
4150 if (!tracing_selftest_disabled) {
4151 event_trace_self_tests();
4152 event_trace_self_test_with_function();
4153 }
4154
4155 return 0;
4156}
4157
4158late_initcall(event_trace_self_tests_init);
4159
4160#endif