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