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[mirror_ubuntu-artful-kernel.git] / kernel / trace / trace_events.c
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
33 DEFINE_MUTEX(event_mutex);
34
35 LIST_HEAD(ftrace_events);
36 static LIST_HEAD(ftrace_generic_fields);
37 static LIST_HEAD(ftrace_common_fields);
38
39 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
40
41 static struct kmem_cache *field_cachep;
42 static struct kmem_cache *file_cachep;
43
44 static inline int system_refcount(struct event_subsystem *system)
45 {
46 return system->ref_count;
47 }
48
49 static int system_refcount_inc(struct event_subsystem *system)
50 {
51 return system->ref_count++;
52 }
53
54 static 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
72 static struct list_head *
73 trace_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
80 static 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
93 struct ftrace_event_field *
94 trace_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
111 static 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
138 int 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 }
151 EXPORT_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
169 static 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
181 static 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
194 static 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 */
210 int 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
224 int 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 }
234 EXPORT_SYMBOL_GPL(trace_event_raw_init);
235
236 bool 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 }
250 EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
251
252 void *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 }
284 EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
285
286 int 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 }
322 EXPORT_SYMBOL_GPL(trace_event_reg);
323
324 void 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
346 void 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
368 static 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 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
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
486 int 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
492 static 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
498 static 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
509 static void
510 event_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
519 static void
520 event_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
531 void 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
546 static void
547 event_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
560 static void
561 event_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
573 static void
574 event_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
589 static void
590 event_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
606 static 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
644 static 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
651 static 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
669 static void __get_system(struct event_subsystem *system)
670 {
671 WARN_ON_ONCE(system_refcount(system) == 0);
672 system_refcount_inc(system);
673 }
674
675 static 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
682 static 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
693 static 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
700 static 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
712 static 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 */
737 static 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
785 static 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
797 static 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 */
847 int 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 }
856 EXPORT_SYMBOL_GPL(trace_set_clr_event);
857
858 /* 128 should be much more than enough */
859 #define EVENT_BUF_SIZE 127
860
861 static ssize_t
862 ftrace_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 parser.buffer[parser.idx] = 0;
889
890 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
891 if (ret)
892 goto out_put;
893 }
894
895 ret = read;
896
897 out_put:
898 trace_parser_put(&parser);
899
900 return ret;
901 }
902
903 static void *
904 t_next(struct seq_file *m, void *v, loff_t *pos)
905 {
906 struct trace_event_file *file = v;
907 struct trace_event_call *call;
908 struct trace_array *tr = m->private;
909
910 (*pos)++;
911
912 list_for_each_entry_continue(file, &tr->events, list) {
913 call = file->event_call;
914 /*
915 * The ftrace subsystem is for showing formats only.
916 * They can not be enabled or disabled via the event files.
917 */
918 if (call->class && call->class->reg &&
919 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
920 return file;
921 }
922
923 return NULL;
924 }
925
926 static void *t_start(struct seq_file *m, loff_t *pos)
927 {
928 struct trace_event_file *file;
929 struct trace_array *tr = m->private;
930 loff_t l;
931
932 mutex_lock(&event_mutex);
933
934 file = list_entry(&tr->events, struct trace_event_file, list);
935 for (l = 0; l <= *pos; ) {
936 file = t_next(m, file, &l);
937 if (!file)
938 break;
939 }
940 return file;
941 }
942
943 static void *
944 s_next(struct seq_file *m, void *v, loff_t *pos)
945 {
946 struct trace_event_file *file = v;
947 struct trace_array *tr = m->private;
948
949 (*pos)++;
950
951 list_for_each_entry_continue(file, &tr->events, list) {
952 if (file->flags & EVENT_FILE_FL_ENABLED)
953 return file;
954 }
955
956 return NULL;
957 }
958
959 static void *s_start(struct seq_file *m, loff_t *pos)
960 {
961 struct trace_event_file *file;
962 struct trace_array *tr = m->private;
963 loff_t l;
964
965 mutex_lock(&event_mutex);
966
967 file = list_entry(&tr->events, struct trace_event_file, list);
968 for (l = 0; l <= *pos; ) {
969 file = s_next(m, file, &l);
970 if (!file)
971 break;
972 }
973 return file;
974 }
975
976 static int t_show(struct seq_file *m, void *v)
977 {
978 struct trace_event_file *file = v;
979 struct trace_event_call *call = file->event_call;
980
981 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
982 seq_printf(m, "%s:", call->class->system);
983 seq_printf(m, "%s\n", trace_event_name(call));
984
985 return 0;
986 }
987
988 static void t_stop(struct seq_file *m, void *p)
989 {
990 mutex_unlock(&event_mutex);
991 }
992
993 static void *
994 p_next(struct seq_file *m, void *v, loff_t *pos)
995 {
996 struct trace_array *tr = m->private;
997 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
998
999 return trace_pid_next(pid_list, v, pos);
1000 }
1001
1002 static void *p_start(struct seq_file *m, loff_t *pos)
1003 __acquires(RCU)
1004 {
1005 struct trace_pid_list *pid_list;
1006 struct trace_array *tr = m->private;
1007
1008 /*
1009 * Grab the mutex, to keep calls to p_next() having the same
1010 * tr->filtered_pids as p_start() has.
1011 * If we just passed the tr->filtered_pids around, then RCU would
1012 * have been enough, but doing that makes things more complex.
1013 */
1014 mutex_lock(&event_mutex);
1015 rcu_read_lock_sched();
1016
1017 pid_list = rcu_dereference_sched(tr->filtered_pids);
1018
1019 if (!pid_list)
1020 return NULL;
1021
1022 return trace_pid_start(pid_list, pos);
1023 }
1024
1025 static void p_stop(struct seq_file *m, void *p)
1026 __releases(RCU)
1027 {
1028 rcu_read_unlock_sched();
1029 mutex_unlock(&event_mutex);
1030 }
1031
1032 static ssize_t
1033 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1034 loff_t *ppos)
1035 {
1036 struct trace_event_file *file;
1037 unsigned long flags;
1038 char buf[4] = "0";
1039
1040 mutex_lock(&event_mutex);
1041 file = event_file_data(filp);
1042 if (likely(file))
1043 flags = file->flags;
1044 mutex_unlock(&event_mutex);
1045
1046 if (!file)
1047 return -ENODEV;
1048
1049 if (flags & EVENT_FILE_FL_ENABLED &&
1050 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1051 strcpy(buf, "1");
1052
1053 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1054 flags & EVENT_FILE_FL_SOFT_MODE)
1055 strcat(buf, "*");
1056
1057 strcat(buf, "\n");
1058
1059 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1060 }
1061
1062 static ssize_t
1063 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1064 loff_t *ppos)
1065 {
1066 struct trace_event_file *file;
1067 unsigned long val;
1068 int ret;
1069
1070 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1071 if (ret)
1072 return ret;
1073
1074 ret = tracing_update_buffers();
1075 if (ret < 0)
1076 return ret;
1077
1078 switch (val) {
1079 case 0:
1080 case 1:
1081 ret = -ENODEV;
1082 mutex_lock(&event_mutex);
1083 file = event_file_data(filp);
1084 if (likely(file))
1085 ret = ftrace_event_enable_disable(file, val);
1086 mutex_unlock(&event_mutex);
1087 break;
1088
1089 default:
1090 return -EINVAL;
1091 }
1092
1093 *ppos += cnt;
1094
1095 return ret ? ret : cnt;
1096 }
1097
1098 static ssize_t
1099 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1100 loff_t *ppos)
1101 {
1102 const char set_to_char[4] = { '?', '0', '1', 'X' };
1103 struct trace_subsystem_dir *dir = filp->private_data;
1104 struct event_subsystem *system = dir->subsystem;
1105 struct trace_event_call *call;
1106 struct trace_event_file *file;
1107 struct trace_array *tr = dir->tr;
1108 char buf[2];
1109 int set = 0;
1110 int ret;
1111
1112 mutex_lock(&event_mutex);
1113 list_for_each_entry(file, &tr->events, list) {
1114 call = file->event_call;
1115 if (!trace_event_name(call) || !call->class || !call->class->reg)
1116 continue;
1117
1118 if (system && strcmp(call->class->system, system->name) != 0)
1119 continue;
1120
1121 /*
1122 * We need to find out if all the events are set
1123 * or if all events or cleared, or if we have
1124 * a mixture.
1125 */
1126 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1127
1128 /*
1129 * If we have a mixture, no need to look further.
1130 */
1131 if (set == 3)
1132 break;
1133 }
1134 mutex_unlock(&event_mutex);
1135
1136 buf[0] = set_to_char[set];
1137 buf[1] = '\n';
1138
1139 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1140
1141 return ret;
1142 }
1143
1144 static ssize_t
1145 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1146 loff_t *ppos)
1147 {
1148 struct trace_subsystem_dir *dir = filp->private_data;
1149 struct event_subsystem *system = dir->subsystem;
1150 const char *name = NULL;
1151 unsigned long val;
1152 ssize_t ret;
1153
1154 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1155 if (ret)
1156 return ret;
1157
1158 ret = tracing_update_buffers();
1159 if (ret < 0)
1160 return ret;
1161
1162 if (val != 0 && val != 1)
1163 return -EINVAL;
1164
1165 /*
1166 * Opening of "enable" adds a ref count to system,
1167 * so the name is safe to use.
1168 */
1169 if (system)
1170 name = system->name;
1171
1172 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1173 if (ret)
1174 goto out;
1175
1176 ret = cnt;
1177
1178 out:
1179 *ppos += cnt;
1180
1181 return ret;
1182 }
1183
1184 enum {
1185 FORMAT_HEADER = 1,
1186 FORMAT_FIELD_SEPERATOR = 2,
1187 FORMAT_PRINTFMT = 3,
1188 };
1189
1190 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1191 {
1192 struct trace_event_call *call = event_file_data(m->private);
1193 struct list_head *common_head = &ftrace_common_fields;
1194 struct list_head *head = trace_get_fields(call);
1195 struct list_head *node = v;
1196
1197 (*pos)++;
1198
1199 switch ((unsigned long)v) {
1200 case FORMAT_HEADER:
1201 node = common_head;
1202 break;
1203
1204 case FORMAT_FIELD_SEPERATOR:
1205 node = head;
1206 break;
1207
1208 case FORMAT_PRINTFMT:
1209 /* all done */
1210 return NULL;
1211 }
1212
1213 node = node->prev;
1214 if (node == common_head)
1215 return (void *)FORMAT_FIELD_SEPERATOR;
1216 else if (node == head)
1217 return (void *)FORMAT_PRINTFMT;
1218 else
1219 return node;
1220 }
1221
1222 static int f_show(struct seq_file *m, void *v)
1223 {
1224 struct trace_event_call *call = event_file_data(m->private);
1225 struct ftrace_event_field *field;
1226 const char *array_descriptor;
1227
1228 switch ((unsigned long)v) {
1229 case FORMAT_HEADER:
1230 seq_printf(m, "name: %s\n", trace_event_name(call));
1231 seq_printf(m, "ID: %d\n", call->event.type);
1232 seq_puts(m, "format:\n");
1233 return 0;
1234
1235 case FORMAT_FIELD_SEPERATOR:
1236 seq_putc(m, '\n');
1237 return 0;
1238
1239 case FORMAT_PRINTFMT:
1240 seq_printf(m, "\nprint fmt: %s\n",
1241 call->print_fmt);
1242 return 0;
1243 }
1244
1245 field = list_entry(v, struct ftrace_event_field, link);
1246 /*
1247 * Smartly shows the array type(except dynamic array).
1248 * Normal:
1249 * field:TYPE VAR
1250 * If TYPE := TYPE[LEN], it is shown:
1251 * field:TYPE VAR[LEN]
1252 */
1253 array_descriptor = strchr(field->type, '[');
1254
1255 if (!strncmp(field->type, "__data_loc", 10))
1256 array_descriptor = NULL;
1257
1258 if (!array_descriptor)
1259 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1260 field->type, field->name, field->offset,
1261 field->size, !!field->is_signed);
1262 else
1263 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1264 (int)(array_descriptor - field->type),
1265 field->type, field->name,
1266 array_descriptor, field->offset,
1267 field->size, !!field->is_signed);
1268
1269 return 0;
1270 }
1271
1272 static void *f_start(struct seq_file *m, loff_t *pos)
1273 {
1274 void *p = (void *)FORMAT_HEADER;
1275 loff_t l = 0;
1276
1277 /* ->stop() is called even if ->start() fails */
1278 mutex_lock(&event_mutex);
1279 if (!event_file_data(m->private))
1280 return ERR_PTR(-ENODEV);
1281
1282 while (l < *pos && p)
1283 p = f_next(m, p, &l);
1284
1285 return p;
1286 }
1287
1288 static void f_stop(struct seq_file *m, void *p)
1289 {
1290 mutex_unlock(&event_mutex);
1291 }
1292
1293 static const struct seq_operations trace_format_seq_ops = {
1294 .start = f_start,
1295 .next = f_next,
1296 .stop = f_stop,
1297 .show = f_show,
1298 };
1299
1300 static int trace_format_open(struct inode *inode, struct file *file)
1301 {
1302 struct seq_file *m;
1303 int ret;
1304
1305 ret = seq_open(file, &trace_format_seq_ops);
1306 if (ret < 0)
1307 return ret;
1308
1309 m = file->private_data;
1310 m->private = file;
1311
1312 return 0;
1313 }
1314
1315 static ssize_t
1316 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1317 {
1318 int id = (long)event_file_data(filp);
1319 char buf[32];
1320 int len;
1321
1322 if (*ppos)
1323 return 0;
1324
1325 if (unlikely(!id))
1326 return -ENODEV;
1327
1328 len = sprintf(buf, "%d\n", id);
1329
1330 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1331 }
1332
1333 static ssize_t
1334 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1335 loff_t *ppos)
1336 {
1337 struct trace_event_file *file;
1338 struct trace_seq *s;
1339 int r = -ENODEV;
1340
1341 if (*ppos)
1342 return 0;
1343
1344 s = kmalloc(sizeof(*s), GFP_KERNEL);
1345
1346 if (!s)
1347 return -ENOMEM;
1348
1349 trace_seq_init(s);
1350
1351 mutex_lock(&event_mutex);
1352 file = event_file_data(filp);
1353 if (file)
1354 print_event_filter(file, s);
1355 mutex_unlock(&event_mutex);
1356
1357 if (file)
1358 r = simple_read_from_buffer(ubuf, cnt, ppos,
1359 s->buffer, trace_seq_used(s));
1360
1361 kfree(s);
1362
1363 return r;
1364 }
1365
1366 static ssize_t
1367 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1368 loff_t *ppos)
1369 {
1370 struct trace_event_file *file;
1371 char *buf;
1372 int err = -ENODEV;
1373
1374 if (cnt >= PAGE_SIZE)
1375 return -EINVAL;
1376
1377 buf = memdup_user_nul(ubuf, cnt);
1378 if (IS_ERR(buf))
1379 return PTR_ERR(buf);
1380
1381 mutex_lock(&event_mutex);
1382 file = event_file_data(filp);
1383 if (file)
1384 err = apply_event_filter(file, buf);
1385 mutex_unlock(&event_mutex);
1386
1387 kfree(buf);
1388 if (err < 0)
1389 return err;
1390
1391 *ppos += cnt;
1392
1393 return cnt;
1394 }
1395
1396 static LIST_HEAD(event_subsystems);
1397
1398 static int subsystem_open(struct inode *inode, struct file *filp)
1399 {
1400 struct event_subsystem *system = NULL;
1401 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1402 struct trace_array *tr;
1403 int ret;
1404
1405 if (tracing_is_disabled())
1406 return -ENODEV;
1407
1408 /* Make sure the system still exists */
1409 mutex_lock(&trace_types_lock);
1410 mutex_lock(&event_mutex);
1411 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1412 list_for_each_entry(dir, &tr->systems, list) {
1413 if (dir == inode->i_private) {
1414 /* Don't open systems with no events */
1415 if (dir->nr_events) {
1416 __get_system_dir(dir);
1417 system = dir->subsystem;
1418 }
1419 goto exit_loop;
1420 }
1421 }
1422 }
1423 exit_loop:
1424 mutex_unlock(&event_mutex);
1425 mutex_unlock(&trace_types_lock);
1426
1427 if (!system)
1428 return -ENODEV;
1429
1430 /* Some versions of gcc think dir can be uninitialized here */
1431 WARN_ON(!dir);
1432
1433 /* Still need to increment the ref count of the system */
1434 if (trace_array_get(tr) < 0) {
1435 put_system(dir);
1436 return -ENODEV;
1437 }
1438
1439 ret = tracing_open_generic(inode, filp);
1440 if (ret < 0) {
1441 trace_array_put(tr);
1442 put_system(dir);
1443 }
1444
1445 return ret;
1446 }
1447
1448 static int system_tr_open(struct inode *inode, struct file *filp)
1449 {
1450 struct trace_subsystem_dir *dir;
1451 struct trace_array *tr = inode->i_private;
1452 int ret;
1453
1454 if (tracing_is_disabled())
1455 return -ENODEV;
1456
1457 if (trace_array_get(tr) < 0)
1458 return -ENODEV;
1459
1460 /* Make a temporary dir that has no system but points to tr */
1461 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1462 if (!dir) {
1463 trace_array_put(tr);
1464 return -ENOMEM;
1465 }
1466
1467 dir->tr = tr;
1468
1469 ret = tracing_open_generic(inode, filp);
1470 if (ret < 0) {
1471 trace_array_put(tr);
1472 kfree(dir);
1473 return ret;
1474 }
1475
1476 filp->private_data = dir;
1477
1478 return 0;
1479 }
1480
1481 static int subsystem_release(struct inode *inode, struct file *file)
1482 {
1483 struct trace_subsystem_dir *dir = file->private_data;
1484
1485 trace_array_put(dir->tr);
1486
1487 /*
1488 * If dir->subsystem is NULL, then this is a temporary
1489 * descriptor that was made for a trace_array to enable
1490 * all subsystems.
1491 */
1492 if (dir->subsystem)
1493 put_system(dir);
1494 else
1495 kfree(dir);
1496
1497 return 0;
1498 }
1499
1500 static ssize_t
1501 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1502 loff_t *ppos)
1503 {
1504 struct trace_subsystem_dir *dir = filp->private_data;
1505 struct event_subsystem *system = dir->subsystem;
1506 struct trace_seq *s;
1507 int r;
1508
1509 if (*ppos)
1510 return 0;
1511
1512 s = kmalloc(sizeof(*s), GFP_KERNEL);
1513 if (!s)
1514 return -ENOMEM;
1515
1516 trace_seq_init(s);
1517
1518 print_subsystem_event_filter(system, s);
1519 r = simple_read_from_buffer(ubuf, cnt, ppos,
1520 s->buffer, trace_seq_used(s));
1521
1522 kfree(s);
1523
1524 return r;
1525 }
1526
1527 static ssize_t
1528 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1529 loff_t *ppos)
1530 {
1531 struct trace_subsystem_dir *dir = filp->private_data;
1532 char *buf;
1533 int err;
1534
1535 if (cnt >= PAGE_SIZE)
1536 return -EINVAL;
1537
1538 buf = memdup_user_nul(ubuf, cnt);
1539 if (IS_ERR(buf))
1540 return PTR_ERR(buf);
1541
1542 err = apply_subsystem_event_filter(dir, buf);
1543 kfree(buf);
1544 if (err < 0)
1545 return err;
1546
1547 *ppos += cnt;
1548
1549 return cnt;
1550 }
1551
1552 static ssize_t
1553 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1554 {
1555 int (*func)(struct trace_seq *s) = filp->private_data;
1556 struct trace_seq *s;
1557 int r;
1558
1559 if (*ppos)
1560 return 0;
1561
1562 s = kmalloc(sizeof(*s), GFP_KERNEL);
1563 if (!s)
1564 return -ENOMEM;
1565
1566 trace_seq_init(s);
1567
1568 func(s);
1569 r = simple_read_from_buffer(ubuf, cnt, ppos,
1570 s->buffer, trace_seq_used(s));
1571
1572 kfree(s);
1573
1574 return r;
1575 }
1576
1577 static void ignore_task_cpu(void *data)
1578 {
1579 struct trace_array *tr = data;
1580 struct trace_pid_list *pid_list;
1581
1582 /*
1583 * This function is called by on_each_cpu() while the
1584 * event_mutex is held.
1585 */
1586 pid_list = rcu_dereference_protected(tr->filtered_pids,
1587 mutex_is_locked(&event_mutex));
1588
1589 this_cpu_write(tr->trace_buffer.data->ignore_pid,
1590 trace_ignore_this_task(pid_list, current));
1591 }
1592
1593 static ssize_t
1594 ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1595 size_t cnt, loff_t *ppos)
1596 {
1597 struct seq_file *m = filp->private_data;
1598 struct trace_array *tr = m->private;
1599 struct trace_pid_list *filtered_pids = NULL;
1600 struct trace_pid_list *pid_list;
1601 struct trace_event_file *file;
1602 ssize_t ret;
1603
1604 if (!cnt)
1605 return 0;
1606
1607 ret = tracing_update_buffers();
1608 if (ret < 0)
1609 return ret;
1610
1611 mutex_lock(&event_mutex);
1612
1613 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1614 lockdep_is_held(&event_mutex));
1615
1616 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
1617 if (ret < 0)
1618 goto out;
1619
1620 rcu_assign_pointer(tr->filtered_pids, pid_list);
1621
1622 list_for_each_entry(file, &tr->events, list) {
1623 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1624 }
1625
1626 if (filtered_pids) {
1627 synchronize_sched();
1628 trace_free_pid_list(filtered_pids);
1629 } else if (pid_list) {
1630 /*
1631 * Register a probe that is called before all other probes
1632 * to set ignore_pid if next or prev do not match.
1633 * Register a probe this is called after all other probes
1634 * to only keep ignore_pid set if next pid matches.
1635 */
1636 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1637 tr, INT_MAX);
1638 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1639 tr, 0);
1640
1641 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1642 tr, INT_MAX);
1643 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1644 tr, 0);
1645
1646 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1647 tr, INT_MAX);
1648 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1649 tr, 0);
1650
1651 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1652 tr, INT_MAX);
1653 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1654 tr, 0);
1655 }
1656
1657 /*
1658 * Ignoring of pids is done at task switch. But we have to
1659 * check for those tasks that are currently running.
1660 * Always do this in case a pid was appended or removed.
1661 */
1662 on_each_cpu(ignore_task_cpu, tr, 1);
1663
1664 out:
1665 mutex_unlock(&event_mutex);
1666
1667 if (ret > 0)
1668 *ppos += ret;
1669
1670 return ret;
1671 }
1672
1673 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1674 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1675 static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
1676 static int ftrace_event_release(struct inode *inode, struct file *file);
1677
1678 static const struct seq_operations show_event_seq_ops = {
1679 .start = t_start,
1680 .next = t_next,
1681 .show = t_show,
1682 .stop = t_stop,
1683 };
1684
1685 static const struct seq_operations show_set_event_seq_ops = {
1686 .start = s_start,
1687 .next = s_next,
1688 .show = t_show,
1689 .stop = t_stop,
1690 };
1691
1692 static const struct seq_operations show_set_pid_seq_ops = {
1693 .start = p_start,
1694 .next = p_next,
1695 .show = trace_pid_show,
1696 .stop = p_stop,
1697 };
1698
1699 static const struct file_operations ftrace_avail_fops = {
1700 .open = ftrace_event_avail_open,
1701 .read = seq_read,
1702 .llseek = seq_lseek,
1703 .release = seq_release,
1704 };
1705
1706 static const struct file_operations ftrace_set_event_fops = {
1707 .open = ftrace_event_set_open,
1708 .read = seq_read,
1709 .write = ftrace_event_write,
1710 .llseek = seq_lseek,
1711 .release = ftrace_event_release,
1712 };
1713
1714 static const struct file_operations ftrace_set_event_pid_fops = {
1715 .open = ftrace_event_set_pid_open,
1716 .read = seq_read,
1717 .write = ftrace_event_pid_write,
1718 .llseek = seq_lseek,
1719 .release = ftrace_event_release,
1720 };
1721
1722 static const struct file_operations ftrace_enable_fops = {
1723 .open = tracing_open_generic,
1724 .read = event_enable_read,
1725 .write = event_enable_write,
1726 .llseek = default_llseek,
1727 };
1728
1729 static const struct file_operations ftrace_event_format_fops = {
1730 .open = trace_format_open,
1731 .read = seq_read,
1732 .llseek = seq_lseek,
1733 .release = seq_release,
1734 };
1735
1736 static const struct file_operations ftrace_event_id_fops = {
1737 .read = event_id_read,
1738 .llseek = default_llseek,
1739 };
1740
1741 static const struct file_operations ftrace_event_filter_fops = {
1742 .open = tracing_open_generic,
1743 .read = event_filter_read,
1744 .write = event_filter_write,
1745 .llseek = default_llseek,
1746 };
1747
1748 static const struct file_operations ftrace_subsystem_filter_fops = {
1749 .open = subsystem_open,
1750 .read = subsystem_filter_read,
1751 .write = subsystem_filter_write,
1752 .llseek = default_llseek,
1753 .release = subsystem_release,
1754 };
1755
1756 static const struct file_operations ftrace_system_enable_fops = {
1757 .open = subsystem_open,
1758 .read = system_enable_read,
1759 .write = system_enable_write,
1760 .llseek = default_llseek,
1761 .release = subsystem_release,
1762 };
1763
1764 static const struct file_operations ftrace_tr_enable_fops = {
1765 .open = system_tr_open,
1766 .read = system_enable_read,
1767 .write = system_enable_write,
1768 .llseek = default_llseek,
1769 .release = subsystem_release,
1770 };
1771
1772 static const struct file_operations ftrace_show_header_fops = {
1773 .open = tracing_open_generic,
1774 .read = show_header,
1775 .llseek = default_llseek,
1776 };
1777
1778 static int
1779 ftrace_event_open(struct inode *inode, struct file *file,
1780 const struct seq_operations *seq_ops)
1781 {
1782 struct seq_file *m;
1783 int ret;
1784
1785 ret = seq_open(file, seq_ops);
1786 if (ret < 0)
1787 return ret;
1788 m = file->private_data;
1789 /* copy tr over to seq ops */
1790 m->private = inode->i_private;
1791
1792 return ret;
1793 }
1794
1795 static int ftrace_event_release(struct inode *inode, struct file *file)
1796 {
1797 struct trace_array *tr = inode->i_private;
1798
1799 trace_array_put(tr);
1800
1801 return seq_release(inode, file);
1802 }
1803
1804 static int
1805 ftrace_event_avail_open(struct inode *inode, struct file *file)
1806 {
1807 const struct seq_operations *seq_ops = &show_event_seq_ops;
1808
1809 return ftrace_event_open(inode, file, seq_ops);
1810 }
1811
1812 static int
1813 ftrace_event_set_open(struct inode *inode, struct file *file)
1814 {
1815 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1816 struct trace_array *tr = inode->i_private;
1817 int ret;
1818
1819 if (trace_array_get(tr) < 0)
1820 return -ENODEV;
1821
1822 if ((file->f_mode & FMODE_WRITE) &&
1823 (file->f_flags & O_TRUNC))
1824 ftrace_clear_events(tr);
1825
1826 ret = ftrace_event_open(inode, file, seq_ops);
1827 if (ret < 0)
1828 trace_array_put(tr);
1829 return ret;
1830 }
1831
1832 static int
1833 ftrace_event_set_pid_open(struct inode *inode, struct file *file)
1834 {
1835 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
1836 struct trace_array *tr = inode->i_private;
1837 int ret;
1838
1839 if (trace_array_get(tr) < 0)
1840 return -ENODEV;
1841
1842 if ((file->f_mode & FMODE_WRITE) &&
1843 (file->f_flags & O_TRUNC))
1844 ftrace_clear_event_pids(tr);
1845
1846 ret = ftrace_event_open(inode, file, seq_ops);
1847 if (ret < 0)
1848 trace_array_put(tr);
1849 return ret;
1850 }
1851
1852 static struct event_subsystem *
1853 create_new_subsystem(const char *name)
1854 {
1855 struct event_subsystem *system;
1856
1857 /* need to create new entry */
1858 system = kmalloc(sizeof(*system), GFP_KERNEL);
1859 if (!system)
1860 return NULL;
1861
1862 system->ref_count = 1;
1863
1864 /* Only allocate if dynamic (kprobes and modules) */
1865 system->name = kstrdup_const(name, GFP_KERNEL);
1866 if (!system->name)
1867 goto out_free;
1868
1869 system->filter = NULL;
1870
1871 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1872 if (!system->filter)
1873 goto out_free;
1874
1875 list_add(&system->list, &event_subsystems);
1876
1877 return system;
1878
1879 out_free:
1880 kfree_const(system->name);
1881 kfree(system);
1882 return NULL;
1883 }
1884
1885 static struct dentry *
1886 event_subsystem_dir(struct trace_array *tr, const char *name,
1887 struct trace_event_file *file, struct dentry *parent)
1888 {
1889 struct trace_subsystem_dir *dir;
1890 struct event_subsystem *system;
1891 struct dentry *entry;
1892
1893 /* First see if we did not already create this dir */
1894 list_for_each_entry(dir, &tr->systems, list) {
1895 system = dir->subsystem;
1896 if (strcmp(system->name, name) == 0) {
1897 dir->nr_events++;
1898 file->system = dir;
1899 return dir->entry;
1900 }
1901 }
1902
1903 /* Now see if the system itself exists. */
1904 list_for_each_entry(system, &event_subsystems, list) {
1905 if (strcmp(system->name, name) == 0)
1906 break;
1907 }
1908 /* Reset system variable when not found */
1909 if (&system->list == &event_subsystems)
1910 system = NULL;
1911
1912 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1913 if (!dir)
1914 goto out_fail;
1915
1916 if (!system) {
1917 system = create_new_subsystem(name);
1918 if (!system)
1919 goto out_free;
1920 } else
1921 __get_system(system);
1922
1923 dir->entry = tracefs_create_dir(name, parent);
1924 if (!dir->entry) {
1925 pr_warn("Failed to create system directory %s\n", name);
1926 __put_system(system);
1927 goto out_free;
1928 }
1929
1930 dir->tr = tr;
1931 dir->ref_count = 1;
1932 dir->nr_events = 1;
1933 dir->subsystem = system;
1934 file->system = dir;
1935
1936 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
1937 &ftrace_subsystem_filter_fops);
1938 if (!entry) {
1939 kfree(system->filter);
1940 system->filter = NULL;
1941 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
1942 }
1943
1944 trace_create_file("enable", 0644, dir->entry, dir,
1945 &ftrace_system_enable_fops);
1946
1947 list_add(&dir->list, &tr->systems);
1948
1949 return dir->entry;
1950
1951 out_free:
1952 kfree(dir);
1953 out_fail:
1954 /* Only print this message if failed on memory allocation */
1955 if (!dir || !system)
1956 pr_warn("No memory to create event subsystem %s\n", name);
1957 return NULL;
1958 }
1959
1960 static int
1961 event_create_dir(struct dentry *parent, struct trace_event_file *file)
1962 {
1963 struct trace_event_call *call = file->event_call;
1964 struct trace_array *tr = file->tr;
1965 struct list_head *head;
1966 struct dentry *d_events;
1967 const char *name;
1968 int ret;
1969
1970 /*
1971 * If the trace point header did not define TRACE_SYSTEM
1972 * then the system would be called "TRACE_SYSTEM".
1973 */
1974 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1975 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1976 if (!d_events)
1977 return -ENOMEM;
1978 } else
1979 d_events = parent;
1980
1981 name = trace_event_name(call);
1982 file->dir = tracefs_create_dir(name, d_events);
1983 if (!file->dir) {
1984 pr_warn("Could not create tracefs '%s' directory\n", name);
1985 return -1;
1986 }
1987
1988 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1989 trace_create_file("enable", 0644, file->dir, file,
1990 &ftrace_enable_fops);
1991
1992 #ifdef CONFIG_PERF_EVENTS
1993 if (call->event.type && call->class->reg)
1994 trace_create_file("id", 0444, file->dir,
1995 (void *)(long)call->event.type,
1996 &ftrace_event_id_fops);
1997 #endif
1998
1999 /*
2000 * Other events may have the same class. Only update
2001 * the fields if they are not already defined.
2002 */
2003 head = trace_get_fields(call);
2004 if (list_empty(head)) {
2005 ret = call->class->define_fields(call);
2006 if (ret < 0) {
2007 pr_warn("Could not initialize trace point events/%s\n",
2008 name);
2009 return -1;
2010 }
2011 }
2012 trace_create_file("filter", 0644, file->dir, file,
2013 &ftrace_event_filter_fops);
2014
2015 /*
2016 * Only event directories that can be enabled should have
2017 * triggers.
2018 */
2019 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2020 trace_create_file("trigger", 0644, file->dir, file,
2021 &event_trigger_fops);
2022
2023 #ifdef CONFIG_HIST_TRIGGERS
2024 trace_create_file("hist", 0444, file->dir, file,
2025 &event_hist_fops);
2026 #endif
2027 trace_create_file("format", 0444, file->dir, call,
2028 &ftrace_event_format_fops);
2029
2030 return 0;
2031 }
2032
2033 static void remove_event_from_tracers(struct trace_event_call *call)
2034 {
2035 struct trace_event_file *file;
2036 struct trace_array *tr;
2037
2038 do_for_each_event_file_safe(tr, file) {
2039 if (file->event_call != call)
2040 continue;
2041
2042 remove_event_file_dir(file);
2043 /*
2044 * The do_for_each_event_file_safe() is
2045 * a double loop. After finding the call for this
2046 * trace_array, we use break to jump to the next
2047 * trace_array.
2048 */
2049 break;
2050 } while_for_each_event_file();
2051 }
2052
2053 static void event_remove(struct trace_event_call *call)
2054 {
2055 struct trace_array *tr;
2056 struct trace_event_file *file;
2057
2058 do_for_each_event_file(tr, file) {
2059 if (file->event_call != call)
2060 continue;
2061 ftrace_event_enable_disable(file, 0);
2062 /*
2063 * The do_for_each_event_file() is
2064 * a double loop. After finding the call for this
2065 * trace_array, we use break to jump to the next
2066 * trace_array.
2067 */
2068 break;
2069 } while_for_each_event_file();
2070
2071 if (call->event.funcs)
2072 __unregister_trace_event(&call->event);
2073 remove_event_from_tracers(call);
2074 list_del(&call->list);
2075 }
2076
2077 static int event_init(struct trace_event_call *call)
2078 {
2079 int ret = 0;
2080 const char *name;
2081
2082 name = trace_event_name(call);
2083 if (WARN_ON(!name))
2084 return -EINVAL;
2085
2086 if (call->class->raw_init) {
2087 ret = call->class->raw_init(call);
2088 if (ret < 0 && ret != -ENOSYS)
2089 pr_warn("Could not initialize trace events/%s\n", name);
2090 }
2091
2092 return ret;
2093 }
2094
2095 static int
2096 __register_event(struct trace_event_call *call, struct module *mod)
2097 {
2098 int ret;
2099
2100 ret = event_init(call);
2101 if (ret < 0)
2102 return ret;
2103
2104 list_add(&call->list, &ftrace_events);
2105 call->mod = mod;
2106
2107 return 0;
2108 }
2109
2110 static char *eval_replace(char *ptr, struct trace_eval_map *map, int len)
2111 {
2112 int rlen;
2113 int elen;
2114
2115 /* Find the length of the eval value as a string */
2116 elen = snprintf(ptr, 0, "%ld", map->eval_value);
2117 /* Make sure there's enough room to replace the string with the value */
2118 if (len < elen)
2119 return NULL;
2120
2121 snprintf(ptr, elen + 1, "%ld", map->eval_value);
2122
2123 /* Get the rest of the string of ptr */
2124 rlen = strlen(ptr + len);
2125 memmove(ptr + elen, ptr + len, rlen);
2126 /* Make sure we end the new string */
2127 ptr[elen + rlen] = 0;
2128
2129 return ptr + elen;
2130 }
2131
2132 static void update_event_printk(struct trace_event_call *call,
2133 struct trace_eval_map *map)
2134 {
2135 char *ptr;
2136 int quote = 0;
2137 int len = strlen(map->eval_string);
2138
2139 for (ptr = call->print_fmt; *ptr; ptr++) {
2140 if (*ptr == '\\') {
2141 ptr++;
2142 /* paranoid */
2143 if (!*ptr)
2144 break;
2145 continue;
2146 }
2147 if (*ptr == '"') {
2148 quote ^= 1;
2149 continue;
2150 }
2151 if (quote)
2152 continue;
2153 if (isdigit(*ptr)) {
2154 /* skip numbers */
2155 do {
2156 ptr++;
2157 /* Check for alpha chars like ULL */
2158 } while (isalnum(*ptr));
2159 if (!*ptr)
2160 break;
2161 /*
2162 * A number must have some kind of delimiter after
2163 * it, and we can ignore that too.
2164 */
2165 continue;
2166 }
2167 if (isalpha(*ptr) || *ptr == '_') {
2168 if (strncmp(map->eval_string, ptr, len) == 0 &&
2169 !isalnum(ptr[len]) && ptr[len] != '_') {
2170 ptr = eval_replace(ptr, map, len);
2171 /* enum/sizeof string smaller than value */
2172 if (WARN_ON_ONCE(!ptr))
2173 return;
2174 /*
2175 * No need to decrement here, as eval_replace()
2176 * returns the pointer to the character passed
2177 * the eval, and two evals can not be placed
2178 * back to back without something in between.
2179 * We can skip that something in between.
2180 */
2181 continue;
2182 }
2183 skip_more:
2184 do {
2185 ptr++;
2186 } while (isalnum(*ptr) || *ptr == '_');
2187 if (!*ptr)
2188 break;
2189 /*
2190 * If what comes after this variable is a '.' or
2191 * '->' then we can continue to ignore that string.
2192 */
2193 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2194 ptr += *ptr == '.' ? 1 : 2;
2195 if (!*ptr)
2196 break;
2197 goto skip_more;
2198 }
2199 /*
2200 * Once again, we can skip the delimiter that came
2201 * after the string.
2202 */
2203 continue;
2204 }
2205 }
2206 }
2207
2208 void trace_event_eval_update(struct trace_eval_map **map, int len)
2209 {
2210 struct trace_event_call *call, *p;
2211 const char *last_system = NULL;
2212 int last_i;
2213 int i;
2214
2215 down_write(&trace_event_sem);
2216 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2217 /* events are usually grouped together with systems */
2218 if (!last_system || call->class->system != last_system) {
2219 last_i = 0;
2220 last_system = call->class->system;
2221 }
2222
2223 for (i = last_i; i < len; i++) {
2224 if (call->class->system == map[i]->system) {
2225 /* Save the first system if need be */
2226 if (!last_i)
2227 last_i = i;
2228 update_event_printk(call, map[i]);
2229 }
2230 }
2231 }
2232 up_write(&trace_event_sem);
2233 }
2234
2235 static struct trace_event_file *
2236 trace_create_new_event(struct trace_event_call *call,
2237 struct trace_array *tr)
2238 {
2239 struct trace_event_file *file;
2240
2241 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2242 if (!file)
2243 return NULL;
2244
2245 file->event_call = call;
2246 file->tr = tr;
2247 atomic_set(&file->sm_ref, 0);
2248 atomic_set(&file->tm_ref, 0);
2249 INIT_LIST_HEAD(&file->triggers);
2250 list_add(&file->list, &tr->events);
2251
2252 return file;
2253 }
2254
2255 /* Add an event to a trace directory */
2256 static int
2257 __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2258 {
2259 struct trace_event_file *file;
2260
2261 file = trace_create_new_event(call, tr);
2262 if (!file)
2263 return -ENOMEM;
2264
2265 return event_create_dir(tr->event_dir, file);
2266 }
2267
2268 /*
2269 * Just create a decriptor for early init. A descriptor is required
2270 * for enabling events at boot. We want to enable events before
2271 * the filesystem is initialized.
2272 */
2273 static __init int
2274 __trace_early_add_new_event(struct trace_event_call *call,
2275 struct trace_array *tr)
2276 {
2277 struct trace_event_file *file;
2278
2279 file = trace_create_new_event(call, tr);
2280 if (!file)
2281 return -ENOMEM;
2282
2283 return 0;
2284 }
2285
2286 struct ftrace_module_file_ops;
2287 static void __add_event_to_tracers(struct trace_event_call *call);
2288
2289 /* Add an additional event_call dynamically */
2290 int trace_add_event_call(struct trace_event_call *call)
2291 {
2292 int ret;
2293 mutex_lock(&trace_types_lock);
2294 mutex_lock(&event_mutex);
2295
2296 ret = __register_event(call, NULL);
2297 if (ret >= 0)
2298 __add_event_to_tracers(call);
2299
2300 mutex_unlock(&event_mutex);
2301 mutex_unlock(&trace_types_lock);
2302 return ret;
2303 }
2304
2305 /*
2306 * Must be called under locking of trace_types_lock, event_mutex and
2307 * trace_event_sem.
2308 */
2309 static void __trace_remove_event_call(struct trace_event_call *call)
2310 {
2311 event_remove(call);
2312 trace_destroy_fields(call);
2313 free_event_filter(call->filter);
2314 call->filter = NULL;
2315 }
2316
2317 static int probe_remove_event_call(struct trace_event_call *call)
2318 {
2319 struct trace_array *tr;
2320 struct trace_event_file *file;
2321
2322 #ifdef CONFIG_PERF_EVENTS
2323 if (call->perf_refcount)
2324 return -EBUSY;
2325 #endif
2326 do_for_each_event_file(tr, file) {
2327 if (file->event_call != call)
2328 continue;
2329 /*
2330 * We can't rely on ftrace_event_enable_disable(enable => 0)
2331 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2332 * TRACE_REG_UNREGISTER.
2333 */
2334 if (file->flags & EVENT_FILE_FL_ENABLED)
2335 return -EBUSY;
2336 /*
2337 * The do_for_each_event_file_safe() is
2338 * a double loop. After finding the call for this
2339 * trace_array, we use break to jump to the next
2340 * trace_array.
2341 */
2342 break;
2343 } while_for_each_event_file();
2344
2345 __trace_remove_event_call(call);
2346
2347 return 0;
2348 }
2349
2350 /* Remove an event_call */
2351 int trace_remove_event_call(struct trace_event_call *call)
2352 {
2353 int ret;
2354
2355 mutex_lock(&trace_types_lock);
2356 mutex_lock(&event_mutex);
2357 down_write(&trace_event_sem);
2358 ret = probe_remove_event_call(call);
2359 up_write(&trace_event_sem);
2360 mutex_unlock(&event_mutex);
2361 mutex_unlock(&trace_types_lock);
2362
2363 return ret;
2364 }
2365
2366 #define for_each_event(event, start, end) \
2367 for (event = start; \
2368 (unsigned long)event < (unsigned long)end; \
2369 event++)
2370
2371 #ifdef CONFIG_MODULES
2372
2373 static void trace_module_add_events(struct module *mod)
2374 {
2375 struct trace_event_call **call, **start, **end;
2376
2377 if (!mod->num_trace_events)
2378 return;
2379
2380 /* Don't add infrastructure for mods without tracepoints */
2381 if (trace_module_has_bad_taint(mod)) {
2382 pr_err("%s: module has bad taint, not creating trace events\n",
2383 mod->name);
2384 return;
2385 }
2386
2387 start = mod->trace_events;
2388 end = mod->trace_events + mod->num_trace_events;
2389
2390 for_each_event(call, start, end) {
2391 __register_event(*call, mod);
2392 __add_event_to_tracers(*call);
2393 }
2394 }
2395
2396 static void trace_module_remove_events(struct module *mod)
2397 {
2398 struct trace_event_call *call, *p;
2399 bool clear_trace = false;
2400
2401 down_write(&trace_event_sem);
2402 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2403 if (call->mod == mod) {
2404 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
2405 clear_trace = true;
2406 __trace_remove_event_call(call);
2407 }
2408 }
2409 up_write(&trace_event_sem);
2410
2411 /*
2412 * It is safest to reset the ring buffer if the module being unloaded
2413 * registered any events that were used. The only worry is if
2414 * a new module gets loaded, and takes on the same id as the events
2415 * of this module. When printing out the buffer, traced events left
2416 * over from this module may be passed to the new module events and
2417 * unexpected results may occur.
2418 */
2419 if (clear_trace)
2420 tracing_reset_all_online_cpus();
2421 }
2422
2423 static int trace_module_notify(struct notifier_block *self,
2424 unsigned long val, void *data)
2425 {
2426 struct module *mod = data;
2427
2428 mutex_lock(&trace_types_lock);
2429 mutex_lock(&event_mutex);
2430 switch (val) {
2431 case MODULE_STATE_COMING:
2432 trace_module_add_events(mod);
2433 break;
2434 case MODULE_STATE_GOING:
2435 trace_module_remove_events(mod);
2436 break;
2437 }
2438 mutex_unlock(&event_mutex);
2439 mutex_unlock(&trace_types_lock);
2440
2441 return 0;
2442 }
2443
2444 static struct notifier_block trace_module_nb = {
2445 .notifier_call = trace_module_notify,
2446 .priority = 1, /* higher than trace.c module notify */
2447 };
2448 #endif /* CONFIG_MODULES */
2449
2450 /* Create a new event directory structure for a trace directory. */
2451 static void
2452 __trace_add_event_dirs(struct trace_array *tr)
2453 {
2454 struct trace_event_call *call;
2455 int ret;
2456
2457 list_for_each_entry(call, &ftrace_events, list) {
2458 ret = __trace_add_new_event(call, tr);
2459 if (ret < 0)
2460 pr_warn("Could not create directory for event %s\n",
2461 trace_event_name(call));
2462 }
2463 }
2464
2465 struct trace_event_file *
2466 find_event_file(struct trace_array *tr, const char *system, const char *event)
2467 {
2468 struct trace_event_file *file;
2469 struct trace_event_call *call;
2470 const char *name;
2471
2472 list_for_each_entry(file, &tr->events, list) {
2473
2474 call = file->event_call;
2475 name = trace_event_name(call);
2476
2477 if (!name || !call->class || !call->class->reg)
2478 continue;
2479
2480 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2481 continue;
2482
2483 if (strcmp(event, name) == 0 &&
2484 strcmp(system, call->class->system) == 0)
2485 return file;
2486 }
2487 return NULL;
2488 }
2489
2490 #ifdef CONFIG_DYNAMIC_FTRACE
2491
2492 /* Avoid typos */
2493 #define ENABLE_EVENT_STR "enable_event"
2494 #define DISABLE_EVENT_STR "disable_event"
2495
2496 struct event_probe_data {
2497 struct trace_event_file *file;
2498 unsigned long count;
2499 int ref;
2500 bool enable;
2501 };
2502
2503 static void update_event_probe(struct event_probe_data *data)
2504 {
2505 if (data->enable)
2506 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2507 else
2508 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2509 }
2510
2511 static void
2512 event_enable_probe(unsigned long ip, unsigned long parent_ip,
2513 struct trace_array *tr, struct ftrace_probe_ops *ops,
2514 void *data)
2515 {
2516 struct ftrace_func_mapper *mapper = data;
2517 struct event_probe_data *edata;
2518 void **pdata;
2519
2520 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2521 if (!pdata || !*pdata)
2522 return;
2523
2524 edata = *pdata;
2525 update_event_probe(edata);
2526 }
2527
2528 static void
2529 event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
2530 struct trace_array *tr, struct ftrace_probe_ops *ops,
2531 void *data)
2532 {
2533 struct ftrace_func_mapper *mapper = data;
2534 struct event_probe_data *edata;
2535 void **pdata;
2536
2537 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2538 if (!pdata || !*pdata)
2539 return;
2540
2541 edata = *pdata;
2542
2543 if (!edata->count)
2544 return;
2545
2546 /* Skip if the event is in a state we want to switch to */
2547 if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
2548 return;
2549
2550 if (edata->count != -1)
2551 (edata->count)--;
2552
2553 update_event_probe(edata);
2554 }
2555
2556 static int
2557 event_enable_print(struct seq_file *m, unsigned long ip,
2558 struct ftrace_probe_ops *ops, void *data)
2559 {
2560 struct ftrace_func_mapper *mapper = data;
2561 struct event_probe_data *edata;
2562 void **pdata;
2563
2564 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2565
2566 if (WARN_ON_ONCE(!pdata || !*pdata))
2567 return 0;
2568
2569 edata = *pdata;
2570
2571 seq_printf(m, "%ps:", (void *)ip);
2572
2573 seq_printf(m, "%s:%s:%s",
2574 edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2575 edata->file->event_call->class->system,
2576 trace_event_name(edata->file->event_call));
2577
2578 if (edata->count == -1)
2579 seq_puts(m, ":unlimited\n");
2580 else
2581 seq_printf(m, ":count=%ld\n", edata->count);
2582
2583 return 0;
2584 }
2585
2586 static int
2587 event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
2588 unsigned long ip, void *init_data, void **data)
2589 {
2590 struct ftrace_func_mapper *mapper = *data;
2591 struct event_probe_data *edata = init_data;
2592 int ret;
2593
2594 if (!mapper) {
2595 mapper = allocate_ftrace_func_mapper();
2596 if (!mapper)
2597 return -ENODEV;
2598 *data = mapper;
2599 }
2600
2601 ret = ftrace_func_mapper_add_ip(mapper, ip, edata);
2602 if (ret < 0)
2603 return ret;
2604
2605 edata->ref++;
2606
2607 return 0;
2608 }
2609
2610 static int free_probe_data(void *data)
2611 {
2612 struct event_probe_data *edata = data;
2613
2614 edata->ref--;
2615 if (!edata->ref) {
2616 /* Remove the SOFT_MODE flag */
2617 __ftrace_event_enable_disable(edata->file, 0, 1);
2618 module_put(edata->file->event_call->mod);
2619 kfree(edata);
2620 }
2621 return 0;
2622 }
2623
2624 static void
2625 event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
2626 unsigned long ip, void *data)
2627 {
2628 struct ftrace_func_mapper *mapper = data;
2629 struct event_probe_data *edata;
2630
2631 if (!ip) {
2632 if (!mapper)
2633 return;
2634 free_ftrace_func_mapper(mapper, free_probe_data);
2635 return;
2636 }
2637
2638 edata = ftrace_func_mapper_remove_ip(mapper, ip);
2639
2640 if (WARN_ON_ONCE(!edata))
2641 return;
2642
2643 if (WARN_ON_ONCE(edata->ref <= 0))
2644 return;
2645
2646 free_probe_data(edata);
2647 }
2648
2649 static struct ftrace_probe_ops event_enable_probe_ops = {
2650 .func = event_enable_probe,
2651 .print = event_enable_print,
2652 .init = event_enable_init,
2653 .free = event_enable_free,
2654 };
2655
2656 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2657 .func = event_enable_count_probe,
2658 .print = event_enable_print,
2659 .init = event_enable_init,
2660 .free = event_enable_free,
2661 };
2662
2663 static struct ftrace_probe_ops event_disable_probe_ops = {
2664 .func = event_enable_probe,
2665 .print = event_enable_print,
2666 .init = event_enable_init,
2667 .free = event_enable_free,
2668 };
2669
2670 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2671 .func = event_enable_count_probe,
2672 .print = event_enable_print,
2673 .init = event_enable_init,
2674 .free = event_enable_free,
2675 };
2676
2677 static int
2678 event_enable_func(struct trace_array *tr, struct ftrace_hash *hash,
2679 char *glob, char *cmd, char *param, int enabled)
2680 {
2681 struct trace_event_file *file;
2682 struct ftrace_probe_ops *ops;
2683 struct event_probe_data *data;
2684 const char *system;
2685 const char *event;
2686 char *number;
2687 bool enable;
2688 int ret;
2689
2690 if (!tr)
2691 return -ENODEV;
2692
2693 /* hash funcs only work with set_ftrace_filter */
2694 if (!enabled || !param)
2695 return -EINVAL;
2696
2697 system = strsep(&param, ":");
2698 if (!param)
2699 return -EINVAL;
2700
2701 event = strsep(&param, ":");
2702
2703 mutex_lock(&event_mutex);
2704
2705 ret = -EINVAL;
2706 file = find_event_file(tr, system, event);
2707 if (!file)
2708 goto out;
2709
2710 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2711
2712 if (enable)
2713 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2714 else
2715 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2716
2717 if (glob[0] == '!') {
2718 ret = unregister_ftrace_function_probe_func(glob+1, tr, ops);
2719 goto out;
2720 }
2721
2722 ret = -ENOMEM;
2723
2724 data = kzalloc(sizeof(*data), GFP_KERNEL);
2725 if (!data)
2726 goto out;
2727
2728 data->enable = enable;
2729 data->count = -1;
2730 data->file = file;
2731
2732 if (!param)
2733 goto out_reg;
2734
2735 number = strsep(&param, ":");
2736
2737 ret = -EINVAL;
2738 if (!strlen(number))
2739 goto out_free;
2740
2741 /*
2742 * We use the callback data field (which is a pointer)
2743 * as our counter.
2744 */
2745 ret = kstrtoul(number, 0, &data->count);
2746 if (ret)
2747 goto out_free;
2748
2749 out_reg:
2750 /* Don't let event modules unload while probe registered */
2751 ret = try_module_get(file->event_call->mod);
2752 if (!ret) {
2753 ret = -EBUSY;
2754 goto out_free;
2755 }
2756
2757 ret = __ftrace_event_enable_disable(file, 1, 1);
2758 if (ret < 0)
2759 goto out_put;
2760
2761 ret = register_ftrace_function_probe(glob, tr, ops, data);
2762 /*
2763 * The above returns on success the # of functions enabled,
2764 * but if it didn't find any functions it returns zero.
2765 * Consider no functions a failure too.
2766 */
2767 if (!ret) {
2768 ret = -ENOENT;
2769 goto out_disable;
2770 } else if (ret < 0)
2771 goto out_disable;
2772 /* Just return zero, not the number of enabled functions */
2773 ret = 0;
2774 out:
2775 mutex_unlock(&event_mutex);
2776 return ret;
2777
2778 out_disable:
2779 __ftrace_event_enable_disable(file, 0, 1);
2780 out_put:
2781 module_put(file->event_call->mod);
2782 out_free:
2783 kfree(data);
2784 goto out;
2785 }
2786
2787 static struct ftrace_func_command event_enable_cmd = {
2788 .name = ENABLE_EVENT_STR,
2789 .func = event_enable_func,
2790 };
2791
2792 static struct ftrace_func_command event_disable_cmd = {
2793 .name = DISABLE_EVENT_STR,
2794 .func = event_enable_func,
2795 };
2796
2797 static __init int register_event_cmds(void)
2798 {
2799 int ret;
2800
2801 ret = register_ftrace_command(&event_enable_cmd);
2802 if (WARN_ON(ret < 0))
2803 return ret;
2804 ret = register_ftrace_command(&event_disable_cmd);
2805 if (WARN_ON(ret < 0))
2806 unregister_ftrace_command(&event_enable_cmd);
2807 return ret;
2808 }
2809 #else
2810 static inline int register_event_cmds(void) { return 0; }
2811 #endif /* CONFIG_DYNAMIC_FTRACE */
2812
2813 /*
2814 * The top level array has already had its trace_event_file
2815 * descriptors created in order to allow for early events to
2816 * be recorded. This function is called after the tracefs has been
2817 * initialized, and we now have to create the files associated
2818 * to the events.
2819 */
2820 static __init void
2821 __trace_early_add_event_dirs(struct trace_array *tr)
2822 {
2823 struct trace_event_file *file;
2824 int ret;
2825
2826
2827 list_for_each_entry(file, &tr->events, list) {
2828 ret = event_create_dir(tr->event_dir, file);
2829 if (ret < 0)
2830 pr_warn("Could not create directory for event %s\n",
2831 trace_event_name(file->event_call));
2832 }
2833 }
2834
2835 /*
2836 * For early boot up, the top trace array requires to have
2837 * a list of events that can be enabled. This must be done before
2838 * the filesystem is set up in order to allow events to be traced
2839 * early.
2840 */
2841 static __init void
2842 __trace_early_add_events(struct trace_array *tr)
2843 {
2844 struct trace_event_call *call;
2845 int ret;
2846
2847 list_for_each_entry(call, &ftrace_events, list) {
2848 /* Early boot up should not have any modules loaded */
2849 if (WARN_ON_ONCE(call->mod))
2850 continue;
2851
2852 ret = __trace_early_add_new_event(call, tr);
2853 if (ret < 0)
2854 pr_warn("Could not create early event %s\n",
2855 trace_event_name(call));
2856 }
2857 }
2858
2859 /* Remove the event directory structure for a trace directory. */
2860 static void
2861 __trace_remove_event_dirs(struct trace_array *tr)
2862 {
2863 struct trace_event_file *file, *next;
2864
2865 list_for_each_entry_safe(file, next, &tr->events, list)
2866 remove_event_file_dir(file);
2867 }
2868
2869 static void __add_event_to_tracers(struct trace_event_call *call)
2870 {
2871 struct trace_array *tr;
2872
2873 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2874 __trace_add_new_event(call, tr);
2875 }
2876
2877 extern struct trace_event_call *__start_ftrace_events[];
2878 extern struct trace_event_call *__stop_ftrace_events[];
2879
2880 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2881
2882 static __init int setup_trace_event(char *str)
2883 {
2884 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2885 ring_buffer_expanded = true;
2886 tracing_selftest_disabled = true;
2887
2888 return 1;
2889 }
2890 __setup("trace_event=", setup_trace_event);
2891
2892 /* Expects to have event_mutex held when called */
2893 static int
2894 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2895 {
2896 struct dentry *d_events;
2897 struct dentry *entry;
2898
2899 entry = tracefs_create_file("set_event", 0644, parent,
2900 tr, &ftrace_set_event_fops);
2901 if (!entry) {
2902 pr_warn("Could not create tracefs 'set_event' entry\n");
2903 return -ENOMEM;
2904 }
2905
2906 d_events = tracefs_create_dir("events", parent);
2907 if (!d_events) {
2908 pr_warn("Could not create tracefs 'events' directory\n");
2909 return -ENOMEM;
2910 }
2911
2912 entry = trace_create_file("enable", 0644, d_events,
2913 tr, &ftrace_tr_enable_fops);
2914 if (!entry) {
2915 pr_warn("Could not create tracefs 'enable' entry\n");
2916 return -ENOMEM;
2917 }
2918
2919 /* There are not as crucial, just warn if they are not created */
2920
2921 entry = tracefs_create_file("set_event_pid", 0644, parent,
2922 tr, &ftrace_set_event_pid_fops);
2923 if (!entry)
2924 pr_warn("Could not create tracefs 'set_event_pid' entry\n");
2925
2926 /* ring buffer internal formats */
2927 entry = trace_create_file("header_page", 0444, d_events,
2928 ring_buffer_print_page_header,
2929 &ftrace_show_header_fops);
2930 if (!entry)
2931 pr_warn("Could not create tracefs 'header_page' entry\n");
2932
2933 entry = trace_create_file("header_event", 0444, d_events,
2934 ring_buffer_print_entry_header,
2935 &ftrace_show_header_fops);
2936 if (!entry)
2937 pr_warn("Could not create tracefs 'header_event' entry\n");
2938
2939 tr->event_dir = d_events;
2940
2941 return 0;
2942 }
2943
2944 /**
2945 * event_trace_add_tracer - add a instance of a trace_array to events
2946 * @parent: The parent dentry to place the files/directories for events in
2947 * @tr: The trace array associated with these events
2948 *
2949 * When a new instance is created, it needs to set up its events
2950 * directory, as well as other files associated with events. It also
2951 * creates the event hierachry in the @parent/events directory.
2952 *
2953 * Returns 0 on success.
2954 */
2955 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2956 {
2957 int ret;
2958
2959 mutex_lock(&event_mutex);
2960
2961 ret = create_event_toplevel_files(parent, tr);
2962 if (ret)
2963 goto out_unlock;
2964
2965 down_write(&trace_event_sem);
2966 __trace_add_event_dirs(tr);
2967 up_write(&trace_event_sem);
2968
2969 out_unlock:
2970 mutex_unlock(&event_mutex);
2971
2972 return ret;
2973 }
2974
2975 /*
2976 * The top trace array already had its file descriptors created.
2977 * Now the files themselves need to be created.
2978 */
2979 static __init int
2980 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2981 {
2982 int ret;
2983
2984 mutex_lock(&event_mutex);
2985
2986 ret = create_event_toplevel_files(parent, tr);
2987 if (ret)
2988 goto out_unlock;
2989
2990 down_write(&trace_event_sem);
2991 __trace_early_add_event_dirs(tr);
2992 up_write(&trace_event_sem);
2993
2994 out_unlock:
2995 mutex_unlock(&event_mutex);
2996
2997 return ret;
2998 }
2999
3000 int event_trace_del_tracer(struct trace_array *tr)
3001 {
3002 mutex_lock(&event_mutex);
3003
3004 /* Disable any event triggers and associated soft-disabled events */
3005 clear_event_triggers(tr);
3006
3007 /* Clear the pid list */
3008 __ftrace_clear_event_pids(tr);
3009
3010 /* Disable any running events */
3011 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3012
3013 /* Access to events are within rcu_read_lock_sched() */
3014 synchronize_sched();
3015
3016 down_write(&trace_event_sem);
3017 __trace_remove_event_dirs(tr);
3018 tracefs_remove_recursive(tr->event_dir);
3019 up_write(&trace_event_sem);
3020
3021 tr->event_dir = NULL;
3022
3023 mutex_unlock(&event_mutex);
3024
3025 return 0;
3026 }
3027
3028 static __init int event_trace_memsetup(void)
3029 {
3030 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3031 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3032 return 0;
3033 }
3034
3035 static __init void
3036 early_enable_events(struct trace_array *tr, bool disable_first)
3037 {
3038 char *buf = bootup_event_buf;
3039 char *token;
3040 int ret;
3041
3042 while (true) {
3043 token = strsep(&buf, ",");
3044
3045 if (!token)
3046 break;
3047
3048 if (*token) {
3049 /* Restarting syscalls requires that we stop them first */
3050 if (disable_first)
3051 ftrace_set_clr_event(tr, token, 0);
3052
3053 ret = ftrace_set_clr_event(tr, token, 1);
3054 if (ret)
3055 pr_warn("Failed to enable trace event: %s\n", token);
3056 }
3057
3058 /* Put back the comma to allow this to be called again */
3059 if (buf)
3060 *(buf - 1) = ',';
3061 }
3062 }
3063
3064 static __init int event_trace_enable(void)
3065 {
3066 struct trace_array *tr = top_trace_array();
3067 struct trace_event_call **iter, *call;
3068 int ret;
3069
3070 if (!tr)
3071 return -ENODEV;
3072
3073 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3074
3075 call = *iter;
3076 ret = event_init(call);
3077 if (!ret)
3078 list_add(&call->list, &ftrace_events);
3079 }
3080
3081 /*
3082 * We need the top trace array to have a working set of trace
3083 * points at early init, before the debug files and directories
3084 * are created. Create the file entries now, and attach them
3085 * to the actual file dentries later.
3086 */
3087 __trace_early_add_events(tr);
3088
3089 early_enable_events(tr, false);
3090
3091 trace_printk_start_comm();
3092
3093 register_event_cmds();
3094
3095 register_trigger_cmds();
3096
3097 return 0;
3098 }
3099
3100 /*
3101 * event_trace_enable() is called from trace_event_init() first to
3102 * initialize events and perhaps start any events that are on the
3103 * command line. Unfortunately, there are some events that will not
3104 * start this early, like the system call tracepoints that need
3105 * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
3106 * is called before pid 1 starts, and this flag is never set, making
3107 * the syscall tracepoint never get reached, but the event is enabled
3108 * regardless (and not doing anything).
3109 */
3110 static __init int event_trace_enable_again(void)
3111 {
3112 struct trace_array *tr;
3113
3114 tr = top_trace_array();
3115 if (!tr)
3116 return -ENODEV;
3117
3118 early_enable_events(tr, true);
3119
3120 return 0;
3121 }
3122
3123 early_initcall(event_trace_enable_again);
3124
3125 static __init int event_trace_init(void)
3126 {
3127 struct trace_array *tr;
3128 struct dentry *d_tracer;
3129 struct dentry *entry;
3130 int ret;
3131
3132 tr = top_trace_array();
3133 if (!tr)
3134 return -ENODEV;
3135
3136 d_tracer = tracing_init_dentry();
3137 if (IS_ERR(d_tracer))
3138 return 0;
3139
3140 entry = tracefs_create_file("available_events", 0444, d_tracer,
3141 tr, &ftrace_avail_fops);
3142 if (!entry)
3143 pr_warn("Could not create tracefs 'available_events' entry\n");
3144
3145 if (trace_define_generic_fields())
3146 pr_warn("tracing: Failed to allocated generic fields");
3147
3148 if (trace_define_common_fields())
3149 pr_warn("tracing: Failed to allocate common fields");
3150
3151 ret = early_event_add_tracer(d_tracer, tr);
3152 if (ret)
3153 return ret;
3154
3155 #ifdef CONFIG_MODULES
3156 ret = register_module_notifier(&trace_module_nb);
3157 if (ret)
3158 pr_warn("Failed to register trace events module notifier\n");
3159 #endif
3160 return 0;
3161 }
3162
3163 void __init trace_event_init(void)
3164 {
3165 event_trace_memsetup();
3166 init_ftrace_syscalls();
3167 event_trace_enable();
3168 }
3169
3170 fs_initcall(event_trace_init);
3171
3172 #ifdef CONFIG_FTRACE_STARTUP_TEST
3173
3174 static DEFINE_SPINLOCK(test_spinlock);
3175 static DEFINE_SPINLOCK(test_spinlock_irq);
3176 static DEFINE_MUTEX(test_mutex);
3177
3178 static __init void test_work(struct work_struct *dummy)
3179 {
3180 spin_lock(&test_spinlock);
3181 spin_lock_irq(&test_spinlock_irq);
3182 udelay(1);
3183 spin_unlock_irq(&test_spinlock_irq);
3184 spin_unlock(&test_spinlock);
3185
3186 mutex_lock(&test_mutex);
3187 msleep(1);
3188 mutex_unlock(&test_mutex);
3189 }
3190
3191 static __init int event_test_thread(void *unused)
3192 {
3193 void *test_malloc;
3194
3195 test_malloc = kmalloc(1234, GFP_KERNEL);
3196 if (!test_malloc)
3197 pr_info("failed to kmalloc\n");
3198
3199 schedule_on_each_cpu(test_work);
3200
3201 kfree(test_malloc);
3202
3203 set_current_state(TASK_INTERRUPTIBLE);
3204 while (!kthread_should_stop()) {
3205 schedule();
3206 set_current_state(TASK_INTERRUPTIBLE);
3207 }
3208 __set_current_state(TASK_RUNNING);
3209
3210 return 0;
3211 }
3212
3213 /*
3214 * Do various things that may trigger events.
3215 */
3216 static __init void event_test_stuff(void)
3217 {
3218 struct task_struct *test_thread;
3219
3220 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3221 msleep(1);
3222 kthread_stop(test_thread);
3223 }
3224
3225 /*
3226 * For every trace event defined, we will test each trace point separately,
3227 * and then by groups, and finally all trace points.
3228 */
3229 static __init void event_trace_self_tests(void)
3230 {
3231 struct trace_subsystem_dir *dir;
3232 struct trace_event_file *file;
3233 struct trace_event_call *call;
3234 struct event_subsystem *system;
3235 struct trace_array *tr;
3236 int ret;
3237
3238 tr = top_trace_array();
3239 if (!tr)
3240 return;
3241
3242 pr_info("Running tests on trace events:\n");
3243
3244 list_for_each_entry(file, &tr->events, list) {
3245
3246 call = file->event_call;
3247
3248 /* Only test those that have a probe */
3249 if (!call->class || !call->class->probe)
3250 continue;
3251
3252 /*
3253 * Testing syscall events here is pretty useless, but
3254 * we still do it if configured. But this is time consuming.
3255 * What we really need is a user thread to perform the
3256 * syscalls as we test.
3257 */
3258 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3259 if (call->class->system &&
3260 strcmp(call->class->system, "syscalls") == 0)
3261 continue;
3262 #endif
3263
3264 pr_info("Testing event %s: ", trace_event_name(call));
3265
3266 /*
3267 * If an event is already enabled, someone is using
3268 * it and the self test should not be on.
3269 */
3270 if (file->flags & EVENT_FILE_FL_ENABLED) {
3271 pr_warn("Enabled event during self test!\n");
3272 WARN_ON_ONCE(1);
3273 continue;
3274 }
3275
3276 ftrace_event_enable_disable(file, 1);
3277 event_test_stuff();
3278 ftrace_event_enable_disable(file, 0);
3279
3280 pr_cont("OK\n");
3281 }
3282
3283 /* Now test at the sub system level */
3284
3285 pr_info("Running tests on trace event systems:\n");
3286
3287 list_for_each_entry(dir, &tr->systems, list) {
3288
3289 system = dir->subsystem;
3290
3291 /* the ftrace system is special, skip it */
3292 if (strcmp(system->name, "ftrace") == 0)
3293 continue;
3294
3295 pr_info("Testing event system %s: ", system->name);
3296
3297 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3298 if (WARN_ON_ONCE(ret)) {
3299 pr_warn("error enabling system %s\n",
3300 system->name);
3301 continue;
3302 }
3303
3304 event_test_stuff();
3305
3306 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3307 if (WARN_ON_ONCE(ret)) {
3308 pr_warn("error disabling system %s\n",
3309 system->name);
3310 continue;
3311 }
3312
3313 pr_cont("OK\n");
3314 }
3315
3316 /* Test with all events enabled */
3317
3318 pr_info("Running tests on all trace events:\n");
3319 pr_info("Testing all events: ");
3320
3321 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3322 if (WARN_ON_ONCE(ret)) {
3323 pr_warn("error enabling all events\n");
3324 return;
3325 }
3326
3327 event_test_stuff();
3328
3329 /* reset sysname */
3330 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3331 if (WARN_ON_ONCE(ret)) {
3332 pr_warn("error disabling all events\n");
3333 return;
3334 }
3335
3336 pr_cont("OK\n");
3337 }
3338
3339 #ifdef CONFIG_FUNCTION_TRACER
3340
3341 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3342
3343 static struct trace_event_file event_trace_file __initdata;
3344
3345 static void __init
3346 function_test_events_call(unsigned long ip, unsigned long parent_ip,
3347 struct ftrace_ops *op, struct pt_regs *pt_regs)
3348 {
3349 struct ring_buffer_event *event;
3350 struct ring_buffer *buffer;
3351 struct ftrace_entry *entry;
3352 unsigned long flags;
3353 long disabled;
3354 int cpu;
3355 int pc;
3356
3357 pc = preempt_count();
3358 preempt_disable_notrace();
3359 cpu = raw_smp_processor_id();
3360 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3361
3362 if (disabled != 1)
3363 goto out;
3364
3365 local_save_flags(flags);
3366
3367 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
3368 TRACE_FN, sizeof(*entry),
3369 flags, pc);
3370 if (!event)
3371 goto out;
3372 entry = ring_buffer_event_data(event);
3373 entry->ip = ip;
3374 entry->parent_ip = parent_ip;
3375
3376 event_trigger_unlock_commit(&event_trace_file, buffer, event,
3377 entry, flags, pc);
3378 out:
3379 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3380 preempt_enable_notrace();
3381 }
3382
3383 static struct ftrace_ops trace_ops __initdata =
3384 {
3385 .func = function_test_events_call,
3386 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
3387 };
3388
3389 static __init void event_trace_self_test_with_function(void)
3390 {
3391 int ret;
3392
3393 event_trace_file.tr = top_trace_array();
3394 if (WARN_ON(!event_trace_file.tr))
3395 return;
3396
3397 ret = register_ftrace_function(&trace_ops);
3398 if (WARN_ON(ret < 0)) {
3399 pr_info("Failed to enable function tracer for event tests\n");
3400 return;
3401 }
3402 pr_info("Running tests again, along with the function tracer\n");
3403 event_trace_self_tests();
3404 unregister_ftrace_function(&trace_ops);
3405 }
3406 #else
3407 static __init void event_trace_self_test_with_function(void)
3408 {
3409 }
3410 #endif
3411
3412 static __init int event_trace_self_tests_init(void)
3413 {
3414 if (!tracing_selftest_disabled) {
3415 event_trace_self_tests();
3416 event_trace_self_test_with_function();
3417 }
3418
3419 return 0;
3420 }
3421
3422 late_initcall(event_trace_self_tests_init);
3423
3424 #endif
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