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03c0a48c3ac4f3daca47a46e401a75f02a826316
[deliverable/linux.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 static DEFINE_SPINLOCK(tracepoint_iter_lock);
287
288 static void output_printk(struct trace_event_buffer *fbuffer)
289 {
290 struct trace_event_call *event_call;
291 struct trace_event *event;
292 unsigned long flags;
293 struct trace_iterator *iter = tracepoint_print_iter;
294
295 if (!iter)
296 return;
297
298 event_call = fbuffer->trace_file->event_call;
299 if (!event_call || !event_call->event.funcs ||
300 !event_call->event.funcs->trace)
301 return;
302
303 event = &fbuffer->trace_file->event_call->event;
304
305 spin_lock_irqsave(&tracepoint_iter_lock, flags);
306 trace_seq_init(&iter->seq);
307 iter->ent = fbuffer->entry;
308 event_call->event.funcs->trace(iter, 0, event);
309 trace_seq_putc(&iter->seq, 0);
310 printk("%s", iter->seq.buffer);
311
312 spin_unlock_irqrestore(&tracepoint_iter_lock, flags);
313 }
314
315 void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)
316 {
317 if (tracepoint_printk)
318 output_printk(fbuffer);
319
320 event_trigger_unlock_commit(fbuffer->trace_file, fbuffer->buffer,
321 fbuffer->event, fbuffer->entry,
322 fbuffer->flags, fbuffer->pc);
323 }
324 EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
325
326 int trace_event_reg(struct trace_event_call *call,
327 enum trace_reg type, void *data)
328 {
329 struct trace_event_file *file = data;
330
331 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
332 switch (type) {
333 case TRACE_REG_REGISTER:
334 return tracepoint_probe_register(call->tp,
335 call->class->probe,
336 file);
337 case TRACE_REG_UNREGISTER:
338 tracepoint_probe_unregister(call->tp,
339 call->class->probe,
340 file);
341 return 0;
342
343 #ifdef CONFIG_PERF_EVENTS
344 case TRACE_REG_PERF_REGISTER:
345 return tracepoint_probe_register(call->tp,
346 call->class->perf_probe,
347 call);
348 case TRACE_REG_PERF_UNREGISTER:
349 tracepoint_probe_unregister(call->tp,
350 call->class->perf_probe,
351 call);
352 return 0;
353 case TRACE_REG_PERF_OPEN:
354 case TRACE_REG_PERF_CLOSE:
355 case TRACE_REG_PERF_ADD:
356 case TRACE_REG_PERF_DEL:
357 return 0;
358 #endif
359 }
360 return 0;
361 }
362 EXPORT_SYMBOL_GPL(trace_event_reg);
363
364 void trace_event_enable_cmd_record(bool enable)
365 {
366 struct trace_event_file *file;
367 struct trace_array *tr;
368
369 mutex_lock(&event_mutex);
370 do_for_each_event_file(tr, file) {
371
372 if (!(file->flags & EVENT_FILE_FL_ENABLED))
373 continue;
374
375 if (enable) {
376 tracing_start_cmdline_record();
377 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
378 } else {
379 tracing_stop_cmdline_record();
380 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
381 }
382 } while_for_each_event_file();
383 mutex_unlock(&event_mutex);
384 }
385
386 static int __ftrace_event_enable_disable(struct trace_event_file *file,
387 int enable, int soft_disable)
388 {
389 struct trace_event_call *call = file->event_call;
390 struct trace_array *tr = file->tr;
391 unsigned long file_flags = file->flags;
392 int ret = 0;
393 int disable;
394
395 switch (enable) {
396 case 0:
397 /*
398 * When soft_disable is set and enable is cleared, the sm_ref
399 * reference counter is decremented. If it reaches 0, we want
400 * to clear the SOFT_DISABLED flag but leave the event in the
401 * state that it was. That is, if the event was enabled and
402 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
403 * is set we do not want the event to be enabled before we
404 * clear the bit.
405 *
406 * When soft_disable is not set but the SOFT_MODE flag is,
407 * we do nothing. Do not disable the tracepoint, otherwise
408 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
409 */
410 if (soft_disable) {
411 if (atomic_dec_return(&file->sm_ref) > 0)
412 break;
413 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
414 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
415 } else
416 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
417
418 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
419 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
420 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
421 tracing_stop_cmdline_record();
422 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
423 }
424 call->class->reg(call, TRACE_REG_UNREGISTER, file);
425 }
426 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
427 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
428 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
429 else
430 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
431 break;
432 case 1:
433 /*
434 * When soft_disable is set and enable is set, we want to
435 * register the tracepoint for the event, but leave the event
436 * as is. That means, if the event was already enabled, we do
437 * nothing (but set SOFT_MODE). If the event is disabled, we
438 * set SOFT_DISABLED before enabling the event tracepoint, so
439 * it still seems to be disabled.
440 */
441 if (!soft_disable)
442 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
443 else {
444 if (atomic_inc_return(&file->sm_ref) > 1)
445 break;
446 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
447 }
448
449 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
450
451 /* Keep the event disabled, when going to SOFT_MODE. */
452 if (soft_disable)
453 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
454
455 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
456 tracing_start_cmdline_record();
457 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
458 }
459 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
460 if (ret) {
461 tracing_stop_cmdline_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
746 list_for_each_entry(file, &tr->events, list) {
747
748 call = file->event_call;
749 name = trace_event_name(call);
750
751 if (!name || !call->class || !call->class->reg)
752 continue;
753
754 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
755 continue;
756
757 if (match &&
758 strcmp(match, name) != 0 &&
759 strcmp(match, call->class->system) != 0)
760 continue;
761
762 if (sub && strcmp(sub, call->class->system) != 0)
763 continue;
764
765 if (event && strcmp(event, name) != 0)
766 continue;
767
768 ftrace_event_enable_disable(file, set);
769
770 ret = 0;
771 }
772
773 return ret;
774 }
775
776 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
777 const char *sub, const char *event, int set)
778 {
779 int ret;
780
781 mutex_lock(&event_mutex);
782 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
783 mutex_unlock(&event_mutex);
784
785 return ret;
786 }
787
788 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
789 {
790 char *event = NULL, *sub = NULL, *match;
791 int ret;
792
793 /*
794 * The buf format can be <subsystem>:<event-name>
795 * *:<event-name> means any event by that name.
796 * :<event-name> is the same.
797 *
798 * <subsystem>:* means all events in that subsystem
799 * <subsystem>: means the same.
800 *
801 * <name> (no ':') means all events in a subsystem with
802 * the name <name> or any event that matches <name>
803 */
804
805 match = strsep(&buf, ":");
806 if (buf) {
807 sub = match;
808 event = buf;
809 match = NULL;
810
811 if (!strlen(sub) || strcmp(sub, "*") == 0)
812 sub = NULL;
813 if (!strlen(event) || strcmp(event, "*") == 0)
814 event = NULL;
815 }
816
817 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
818
819 /* Put back the colon to allow this to be called again */
820 if (buf)
821 *(buf - 1) = ':';
822
823 return ret;
824 }
825
826 /**
827 * trace_set_clr_event - enable or disable an event
828 * @system: system name to match (NULL for any system)
829 * @event: event name to match (NULL for all events, within system)
830 * @set: 1 to enable, 0 to disable
831 *
832 * This is a way for other parts of the kernel to enable or disable
833 * event recording.
834 *
835 * Returns 0 on success, -EINVAL if the parameters do not match any
836 * registered events.
837 */
838 int trace_set_clr_event(const char *system, const char *event, int set)
839 {
840 struct trace_array *tr = top_trace_array();
841
842 if (!tr)
843 return -ENODEV;
844
845 return __ftrace_set_clr_event(tr, NULL, system, event, set);
846 }
847 EXPORT_SYMBOL_GPL(trace_set_clr_event);
848
849 /* 128 should be much more than enough */
850 #define EVENT_BUF_SIZE 127
851
852 static ssize_t
853 ftrace_event_write(struct file *file, const char __user *ubuf,
854 size_t cnt, loff_t *ppos)
855 {
856 struct trace_parser parser;
857 struct seq_file *m = file->private_data;
858 struct trace_array *tr = m->private;
859 ssize_t read, ret;
860
861 if (!cnt)
862 return 0;
863
864 ret = tracing_update_buffers();
865 if (ret < 0)
866 return ret;
867
868 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
869 return -ENOMEM;
870
871 read = trace_get_user(&parser, ubuf, cnt, ppos);
872
873 if (read >= 0 && trace_parser_loaded((&parser))) {
874 int set = 1;
875
876 if (*parser.buffer == '!')
877 set = 0;
878
879 parser.buffer[parser.idx] = 0;
880
881 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
882 if (ret)
883 goto out_put;
884 }
885
886 ret = read;
887
888 out_put:
889 trace_parser_put(&parser);
890
891 return ret;
892 }
893
894 static void *
895 t_next(struct seq_file *m, void *v, loff_t *pos)
896 {
897 struct trace_event_file *file = v;
898 struct trace_event_call *call;
899 struct trace_array *tr = m->private;
900
901 (*pos)++;
902
903 list_for_each_entry_continue(file, &tr->events, list) {
904 call = file->event_call;
905 /*
906 * The ftrace subsystem is for showing formats only.
907 * They can not be enabled or disabled via the event files.
908 */
909 if (call->class && call->class->reg &&
910 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
911 return file;
912 }
913
914 return NULL;
915 }
916
917 static void *t_start(struct seq_file *m, loff_t *pos)
918 {
919 struct trace_event_file *file;
920 struct trace_array *tr = m->private;
921 loff_t l;
922
923 mutex_lock(&event_mutex);
924
925 file = list_entry(&tr->events, struct trace_event_file, list);
926 for (l = 0; l <= *pos; ) {
927 file = t_next(m, file, &l);
928 if (!file)
929 break;
930 }
931 return file;
932 }
933
934 static void *
935 s_next(struct seq_file *m, void *v, loff_t *pos)
936 {
937 struct trace_event_file *file = v;
938 struct trace_array *tr = m->private;
939
940 (*pos)++;
941
942 list_for_each_entry_continue(file, &tr->events, list) {
943 if (file->flags & EVENT_FILE_FL_ENABLED)
944 return file;
945 }
946
947 return NULL;
948 }
949
950 static void *s_start(struct seq_file *m, loff_t *pos)
951 {
952 struct trace_event_file *file;
953 struct trace_array *tr = m->private;
954 loff_t l;
955
956 mutex_lock(&event_mutex);
957
958 file = list_entry(&tr->events, struct trace_event_file, list);
959 for (l = 0; l <= *pos; ) {
960 file = s_next(m, file, &l);
961 if (!file)
962 break;
963 }
964 return file;
965 }
966
967 static int t_show(struct seq_file *m, void *v)
968 {
969 struct trace_event_file *file = v;
970 struct trace_event_call *call = file->event_call;
971
972 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
973 seq_printf(m, "%s:", call->class->system);
974 seq_printf(m, "%s\n", trace_event_name(call));
975
976 return 0;
977 }
978
979 static void t_stop(struct seq_file *m, void *p)
980 {
981 mutex_unlock(&event_mutex);
982 }
983
984 static void *
985 p_next(struct seq_file *m, void *v, loff_t *pos)
986 {
987 struct trace_array *tr = m->private;
988 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
989
990 return trace_pid_next(pid_list, v, pos);
991 }
992
993 static void *p_start(struct seq_file *m, loff_t *pos)
994 __acquires(RCU)
995 {
996 struct trace_pid_list *pid_list;
997 struct trace_array *tr = m->private;
998
999 /*
1000 * Grab the mutex, to keep calls to p_next() having the same
1001 * tr->filtered_pids as p_start() has.
1002 * If we just passed the tr->filtered_pids around, then RCU would
1003 * have been enough, but doing that makes things more complex.
1004 */
1005 mutex_lock(&event_mutex);
1006 rcu_read_lock_sched();
1007
1008 pid_list = rcu_dereference_sched(tr->filtered_pids);
1009
1010 if (!pid_list)
1011 return NULL;
1012
1013 return trace_pid_start(pid_list, pos);
1014 }
1015
1016 static void p_stop(struct seq_file *m, void *p)
1017 __releases(RCU)
1018 {
1019 rcu_read_unlock_sched();
1020 mutex_unlock(&event_mutex);
1021 }
1022
1023 static ssize_t
1024 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1025 loff_t *ppos)
1026 {
1027 struct trace_event_file *file;
1028 unsigned long flags;
1029 char buf[4] = "0";
1030
1031 mutex_lock(&event_mutex);
1032 file = event_file_data(filp);
1033 if (likely(file))
1034 flags = file->flags;
1035 mutex_unlock(&event_mutex);
1036
1037 if (!file)
1038 return -ENODEV;
1039
1040 if (flags & EVENT_FILE_FL_ENABLED &&
1041 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1042 strcpy(buf, "1");
1043
1044 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1045 flags & EVENT_FILE_FL_SOFT_MODE)
1046 strcat(buf, "*");
1047
1048 strcat(buf, "\n");
1049
1050 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1051 }
1052
1053 static ssize_t
1054 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1055 loff_t *ppos)
1056 {
1057 struct trace_event_file *file;
1058 unsigned long val;
1059 int ret;
1060
1061 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1062 if (ret)
1063 return ret;
1064
1065 ret = tracing_update_buffers();
1066 if (ret < 0)
1067 return ret;
1068
1069 switch (val) {
1070 case 0:
1071 case 1:
1072 ret = -ENODEV;
1073 mutex_lock(&event_mutex);
1074 file = event_file_data(filp);
1075 if (likely(file))
1076 ret = ftrace_event_enable_disable(file, val);
1077 mutex_unlock(&event_mutex);
1078 break;
1079
1080 default:
1081 return -EINVAL;
1082 }
1083
1084 *ppos += cnt;
1085
1086 return ret ? ret : cnt;
1087 }
1088
1089 static ssize_t
1090 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1091 loff_t *ppos)
1092 {
1093 const char set_to_char[4] = { '?', '0', '1', 'X' };
1094 struct trace_subsystem_dir *dir = filp->private_data;
1095 struct event_subsystem *system = dir->subsystem;
1096 struct trace_event_call *call;
1097 struct trace_event_file *file;
1098 struct trace_array *tr = dir->tr;
1099 char buf[2];
1100 int set = 0;
1101 int ret;
1102
1103 mutex_lock(&event_mutex);
1104 list_for_each_entry(file, &tr->events, list) {
1105 call = file->event_call;
1106 if (!trace_event_name(call) || !call->class || !call->class->reg)
1107 continue;
1108
1109 if (system && strcmp(call->class->system, system->name) != 0)
1110 continue;
1111
1112 /*
1113 * We need to find out if all the events are set
1114 * or if all events or cleared, or if we have
1115 * a mixture.
1116 */
1117 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1118
1119 /*
1120 * If we have a mixture, no need to look further.
1121 */
1122 if (set == 3)
1123 break;
1124 }
1125 mutex_unlock(&event_mutex);
1126
1127 buf[0] = set_to_char[set];
1128 buf[1] = '\n';
1129
1130 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1131
1132 return ret;
1133 }
1134
1135 static ssize_t
1136 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1137 loff_t *ppos)
1138 {
1139 struct trace_subsystem_dir *dir = filp->private_data;
1140 struct event_subsystem *system = dir->subsystem;
1141 const char *name = NULL;
1142 unsigned long val;
1143 ssize_t ret;
1144
1145 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1146 if (ret)
1147 return ret;
1148
1149 ret = tracing_update_buffers();
1150 if (ret < 0)
1151 return ret;
1152
1153 if (val != 0 && val != 1)
1154 return -EINVAL;
1155
1156 /*
1157 * Opening of "enable" adds a ref count to system,
1158 * so the name is safe to use.
1159 */
1160 if (system)
1161 name = system->name;
1162
1163 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1164 if (ret)
1165 goto out;
1166
1167 ret = cnt;
1168
1169 out:
1170 *ppos += cnt;
1171
1172 return ret;
1173 }
1174
1175 enum {
1176 FORMAT_HEADER = 1,
1177 FORMAT_FIELD_SEPERATOR = 2,
1178 FORMAT_PRINTFMT = 3,
1179 };
1180
1181 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1182 {
1183 struct trace_event_call *call = event_file_data(m->private);
1184 struct list_head *common_head = &ftrace_common_fields;
1185 struct list_head *head = trace_get_fields(call);
1186 struct list_head *node = v;
1187
1188 (*pos)++;
1189
1190 switch ((unsigned long)v) {
1191 case FORMAT_HEADER:
1192 node = common_head;
1193 break;
1194
1195 case FORMAT_FIELD_SEPERATOR:
1196 node = head;
1197 break;
1198
1199 case FORMAT_PRINTFMT:
1200 /* all done */
1201 return NULL;
1202 }
1203
1204 node = node->prev;
1205 if (node == common_head)
1206 return (void *)FORMAT_FIELD_SEPERATOR;
1207 else if (node == head)
1208 return (void *)FORMAT_PRINTFMT;
1209 else
1210 return node;
1211 }
1212
1213 static int f_show(struct seq_file *m, void *v)
1214 {
1215 struct trace_event_call *call = event_file_data(m->private);
1216 struct ftrace_event_field *field;
1217 const char *array_descriptor;
1218
1219 switch ((unsigned long)v) {
1220 case FORMAT_HEADER:
1221 seq_printf(m, "name: %s\n", trace_event_name(call));
1222 seq_printf(m, "ID: %d\n", call->event.type);
1223 seq_puts(m, "format:\n");
1224 return 0;
1225
1226 case FORMAT_FIELD_SEPERATOR:
1227 seq_putc(m, '\n');
1228 return 0;
1229
1230 case FORMAT_PRINTFMT:
1231 seq_printf(m, "\nprint fmt: %s\n",
1232 call->print_fmt);
1233 return 0;
1234 }
1235
1236 field = list_entry(v, struct ftrace_event_field, link);
1237 /*
1238 * Smartly shows the array type(except dynamic array).
1239 * Normal:
1240 * field:TYPE VAR
1241 * If TYPE := TYPE[LEN], it is shown:
1242 * field:TYPE VAR[LEN]
1243 */
1244 array_descriptor = strchr(field->type, '[');
1245
1246 if (!strncmp(field->type, "__data_loc", 10))
1247 array_descriptor = NULL;
1248
1249 if (!array_descriptor)
1250 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1251 field->type, field->name, field->offset,
1252 field->size, !!field->is_signed);
1253 else
1254 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1255 (int)(array_descriptor - field->type),
1256 field->type, field->name,
1257 array_descriptor, field->offset,
1258 field->size, !!field->is_signed);
1259
1260 return 0;
1261 }
1262
1263 static void *f_start(struct seq_file *m, loff_t *pos)
1264 {
1265 void *p = (void *)FORMAT_HEADER;
1266 loff_t l = 0;
1267
1268 /* ->stop() is called even if ->start() fails */
1269 mutex_lock(&event_mutex);
1270 if (!event_file_data(m->private))
1271 return ERR_PTR(-ENODEV);
1272
1273 while (l < *pos && p)
1274 p = f_next(m, p, &l);
1275
1276 return p;
1277 }
1278
1279 static void f_stop(struct seq_file *m, void *p)
1280 {
1281 mutex_unlock(&event_mutex);
1282 }
1283
1284 static const struct seq_operations trace_format_seq_ops = {
1285 .start = f_start,
1286 .next = f_next,
1287 .stop = f_stop,
1288 .show = f_show,
1289 };
1290
1291 static int trace_format_open(struct inode *inode, struct file *file)
1292 {
1293 struct seq_file *m;
1294 int ret;
1295
1296 ret = seq_open(file, &trace_format_seq_ops);
1297 if (ret < 0)
1298 return ret;
1299
1300 m = file->private_data;
1301 m->private = file;
1302
1303 return 0;
1304 }
1305
1306 static ssize_t
1307 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1308 {
1309 int id = (long)event_file_data(filp);
1310 char buf[32];
1311 int len;
1312
1313 if (*ppos)
1314 return 0;
1315
1316 if (unlikely(!id))
1317 return -ENODEV;
1318
1319 len = sprintf(buf, "%d\n", id);
1320
1321 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1322 }
1323
1324 static ssize_t
1325 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1326 loff_t *ppos)
1327 {
1328 struct trace_event_file *file;
1329 struct trace_seq *s;
1330 int r = -ENODEV;
1331
1332 if (*ppos)
1333 return 0;
1334
1335 s = kmalloc(sizeof(*s), GFP_KERNEL);
1336
1337 if (!s)
1338 return -ENOMEM;
1339
1340 trace_seq_init(s);
1341
1342 mutex_lock(&event_mutex);
1343 file = event_file_data(filp);
1344 if (file)
1345 print_event_filter(file, s);
1346 mutex_unlock(&event_mutex);
1347
1348 if (file)
1349 r = simple_read_from_buffer(ubuf, cnt, ppos,
1350 s->buffer, trace_seq_used(s));
1351
1352 kfree(s);
1353
1354 return r;
1355 }
1356
1357 static ssize_t
1358 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1359 loff_t *ppos)
1360 {
1361 struct trace_event_file *file;
1362 char *buf;
1363 int err = -ENODEV;
1364
1365 if (cnt >= PAGE_SIZE)
1366 return -EINVAL;
1367
1368 buf = memdup_user_nul(ubuf, cnt);
1369 if (IS_ERR(buf))
1370 return PTR_ERR(buf);
1371
1372 mutex_lock(&event_mutex);
1373 file = event_file_data(filp);
1374 if (file)
1375 err = apply_event_filter(file, buf);
1376 mutex_unlock(&event_mutex);
1377
1378 kfree(buf);
1379 if (err < 0)
1380 return err;
1381
1382 *ppos += cnt;
1383
1384 return cnt;
1385 }
1386
1387 static LIST_HEAD(event_subsystems);
1388
1389 static int subsystem_open(struct inode *inode, struct file *filp)
1390 {
1391 struct event_subsystem *system = NULL;
1392 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1393 struct trace_array *tr;
1394 int ret;
1395
1396 if (tracing_is_disabled())
1397 return -ENODEV;
1398
1399 /* Make sure the system still exists */
1400 mutex_lock(&trace_types_lock);
1401 mutex_lock(&event_mutex);
1402 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1403 list_for_each_entry(dir, &tr->systems, list) {
1404 if (dir == inode->i_private) {
1405 /* Don't open systems with no events */
1406 if (dir->nr_events) {
1407 __get_system_dir(dir);
1408 system = dir->subsystem;
1409 }
1410 goto exit_loop;
1411 }
1412 }
1413 }
1414 exit_loop:
1415 mutex_unlock(&event_mutex);
1416 mutex_unlock(&trace_types_lock);
1417
1418 if (!system)
1419 return -ENODEV;
1420
1421 /* Some versions of gcc think dir can be uninitialized here */
1422 WARN_ON(!dir);
1423
1424 /* Still need to increment the ref count of the system */
1425 if (trace_array_get(tr) < 0) {
1426 put_system(dir);
1427 return -ENODEV;
1428 }
1429
1430 ret = tracing_open_generic(inode, filp);
1431 if (ret < 0) {
1432 trace_array_put(tr);
1433 put_system(dir);
1434 }
1435
1436 return ret;
1437 }
1438
1439 static int system_tr_open(struct inode *inode, struct file *filp)
1440 {
1441 struct trace_subsystem_dir *dir;
1442 struct trace_array *tr = inode->i_private;
1443 int ret;
1444
1445 if (tracing_is_disabled())
1446 return -ENODEV;
1447
1448 if (trace_array_get(tr) < 0)
1449 return -ENODEV;
1450
1451 /* Make a temporary dir that has no system but points to tr */
1452 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1453 if (!dir) {
1454 trace_array_put(tr);
1455 return -ENOMEM;
1456 }
1457
1458 dir->tr = tr;
1459
1460 ret = tracing_open_generic(inode, filp);
1461 if (ret < 0) {
1462 trace_array_put(tr);
1463 kfree(dir);
1464 return ret;
1465 }
1466
1467 filp->private_data = dir;
1468
1469 return 0;
1470 }
1471
1472 static int subsystem_release(struct inode *inode, struct file *file)
1473 {
1474 struct trace_subsystem_dir *dir = file->private_data;
1475
1476 trace_array_put(dir->tr);
1477
1478 /*
1479 * If dir->subsystem is NULL, then this is a temporary
1480 * descriptor that was made for a trace_array to enable
1481 * all subsystems.
1482 */
1483 if (dir->subsystem)
1484 put_system(dir);
1485 else
1486 kfree(dir);
1487
1488 return 0;
1489 }
1490
1491 static ssize_t
1492 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1493 loff_t *ppos)
1494 {
1495 struct trace_subsystem_dir *dir = filp->private_data;
1496 struct event_subsystem *system = dir->subsystem;
1497 struct trace_seq *s;
1498 int r;
1499
1500 if (*ppos)
1501 return 0;
1502
1503 s = kmalloc(sizeof(*s), GFP_KERNEL);
1504 if (!s)
1505 return -ENOMEM;
1506
1507 trace_seq_init(s);
1508
1509 print_subsystem_event_filter(system, s);
1510 r = simple_read_from_buffer(ubuf, cnt, ppos,
1511 s->buffer, trace_seq_used(s));
1512
1513 kfree(s);
1514
1515 return r;
1516 }
1517
1518 static ssize_t
1519 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1520 loff_t *ppos)
1521 {
1522 struct trace_subsystem_dir *dir = filp->private_data;
1523 char *buf;
1524 int err;
1525
1526 if (cnt >= PAGE_SIZE)
1527 return -EINVAL;
1528
1529 buf = memdup_user_nul(ubuf, cnt);
1530 if (IS_ERR(buf))
1531 return PTR_ERR(buf);
1532
1533 err = apply_subsystem_event_filter(dir, buf);
1534 kfree(buf);
1535 if (err < 0)
1536 return err;
1537
1538 *ppos += cnt;
1539
1540 return cnt;
1541 }
1542
1543 static ssize_t
1544 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1545 {
1546 int (*func)(struct trace_seq *s) = filp->private_data;
1547 struct trace_seq *s;
1548 int r;
1549
1550 if (*ppos)
1551 return 0;
1552
1553 s = kmalloc(sizeof(*s), GFP_KERNEL);
1554 if (!s)
1555 return -ENOMEM;
1556
1557 trace_seq_init(s);
1558
1559 func(s);
1560 r = simple_read_from_buffer(ubuf, cnt, ppos,
1561 s->buffer, trace_seq_used(s));
1562
1563 kfree(s);
1564
1565 return r;
1566 }
1567
1568 static void ignore_task_cpu(void *data)
1569 {
1570 struct trace_array *tr = data;
1571 struct trace_pid_list *pid_list;
1572
1573 /*
1574 * This function is called by on_each_cpu() while the
1575 * event_mutex is held.
1576 */
1577 pid_list = rcu_dereference_protected(tr->filtered_pids,
1578 mutex_is_locked(&event_mutex));
1579
1580 this_cpu_write(tr->trace_buffer.data->ignore_pid,
1581 trace_ignore_this_task(pid_list, current));
1582 }
1583
1584 static ssize_t
1585 ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1586 size_t cnt, loff_t *ppos)
1587 {
1588 struct seq_file *m = filp->private_data;
1589 struct trace_array *tr = m->private;
1590 struct trace_pid_list *filtered_pids = NULL;
1591 struct trace_pid_list *pid_list;
1592 struct trace_event_file *file;
1593 ssize_t ret;
1594
1595 if (!cnt)
1596 return 0;
1597
1598 ret = tracing_update_buffers();
1599 if (ret < 0)
1600 return ret;
1601
1602 mutex_lock(&event_mutex);
1603
1604 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1605 lockdep_is_held(&event_mutex));
1606
1607 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
1608 if (ret < 0)
1609 goto out;
1610
1611 rcu_assign_pointer(tr->filtered_pids, pid_list);
1612
1613 list_for_each_entry(file, &tr->events, list) {
1614 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1615 }
1616
1617 if (filtered_pids) {
1618 synchronize_sched();
1619 trace_free_pid_list(filtered_pids);
1620 } else if (pid_list) {
1621 /*
1622 * Register a probe that is called before all other probes
1623 * to set ignore_pid if next or prev do not match.
1624 * Register a probe this is called after all other probes
1625 * to only keep ignore_pid set if next pid matches.
1626 */
1627 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1628 tr, INT_MAX);
1629 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1630 tr, 0);
1631
1632 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1633 tr, INT_MAX);
1634 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1635 tr, 0);
1636
1637 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1638 tr, INT_MAX);
1639 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1640 tr, 0);
1641
1642 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1643 tr, INT_MAX);
1644 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1645 tr, 0);
1646 }
1647
1648 /*
1649 * Ignoring of pids is done at task switch. But we have to
1650 * check for those tasks that are currently running.
1651 * Always do this in case a pid was appended or removed.
1652 */
1653 on_each_cpu(ignore_task_cpu, tr, 1);
1654
1655 out:
1656 mutex_unlock(&event_mutex);
1657
1658 if (ret > 0)
1659 *ppos += ret;
1660
1661 return ret;
1662 }
1663
1664 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1665 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1666 static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
1667 static int ftrace_event_release(struct inode *inode, struct file *file);
1668
1669 static const struct seq_operations show_event_seq_ops = {
1670 .start = t_start,
1671 .next = t_next,
1672 .show = t_show,
1673 .stop = t_stop,
1674 };
1675
1676 static const struct seq_operations show_set_event_seq_ops = {
1677 .start = s_start,
1678 .next = s_next,
1679 .show = t_show,
1680 .stop = t_stop,
1681 };
1682
1683 static const struct seq_operations show_set_pid_seq_ops = {
1684 .start = p_start,
1685 .next = p_next,
1686 .show = trace_pid_show,
1687 .stop = p_stop,
1688 };
1689
1690 static const struct file_operations ftrace_avail_fops = {
1691 .open = ftrace_event_avail_open,
1692 .read = seq_read,
1693 .llseek = seq_lseek,
1694 .release = seq_release,
1695 };
1696
1697 static const struct file_operations ftrace_set_event_fops = {
1698 .open = ftrace_event_set_open,
1699 .read = seq_read,
1700 .write = ftrace_event_write,
1701 .llseek = seq_lseek,
1702 .release = ftrace_event_release,
1703 };
1704
1705 static const struct file_operations ftrace_set_event_pid_fops = {
1706 .open = ftrace_event_set_pid_open,
1707 .read = seq_read,
1708 .write = ftrace_event_pid_write,
1709 .llseek = seq_lseek,
1710 .release = ftrace_event_release,
1711 };
1712
1713 static const struct file_operations ftrace_enable_fops = {
1714 .open = tracing_open_generic,
1715 .read = event_enable_read,
1716 .write = event_enable_write,
1717 .llseek = default_llseek,
1718 };
1719
1720 static const struct file_operations ftrace_event_format_fops = {
1721 .open = trace_format_open,
1722 .read = seq_read,
1723 .llseek = seq_lseek,
1724 .release = seq_release,
1725 };
1726
1727 static const struct file_operations ftrace_event_id_fops = {
1728 .read = event_id_read,
1729 .llseek = default_llseek,
1730 };
1731
1732 static const struct file_operations ftrace_event_filter_fops = {
1733 .open = tracing_open_generic,
1734 .read = event_filter_read,
1735 .write = event_filter_write,
1736 .llseek = default_llseek,
1737 };
1738
1739 static const struct file_operations ftrace_subsystem_filter_fops = {
1740 .open = subsystem_open,
1741 .read = subsystem_filter_read,
1742 .write = subsystem_filter_write,
1743 .llseek = default_llseek,
1744 .release = subsystem_release,
1745 };
1746
1747 static const struct file_operations ftrace_system_enable_fops = {
1748 .open = subsystem_open,
1749 .read = system_enable_read,
1750 .write = system_enable_write,
1751 .llseek = default_llseek,
1752 .release = subsystem_release,
1753 };
1754
1755 static const struct file_operations ftrace_tr_enable_fops = {
1756 .open = system_tr_open,
1757 .read = system_enable_read,
1758 .write = system_enable_write,
1759 .llseek = default_llseek,
1760 .release = subsystem_release,
1761 };
1762
1763 static const struct file_operations ftrace_show_header_fops = {
1764 .open = tracing_open_generic,
1765 .read = show_header,
1766 .llseek = default_llseek,
1767 };
1768
1769 static int
1770 ftrace_event_open(struct inode *inode, struct file *file,
1771 const struct seq_operations *seq_ops)
1772 {
1773 struct seq_file *m;
1774 int ret;
1775
1776 ret = seq_open(file, seq_ops);
1777 if (ret < 0)
1778 return ret;
1779 m = file->private_data;
1780 /* copy tr over to seq ops */
1781 m->private = inode->i_private;
1782
1783 return ret;
1784 }
1785
1786 static int ftrace_event_release(struct inode *inode, struct file *file)
1787 {
1788 struct trace_array *tr = inode->i_private;
1789
1790 trace_array_put(tr);
1791
1792 return seq_release(inode, file);
1793 }
1794
1795 static int
1796 ftrace_event_avail_open(struct inode *inode, struct file *file)
1797 {
1798 const struct seq_operations *seq_ops = &show_event_seq_ops;
1799
1800 return ftrace_event_open(inode, file, seq_ops);
1801 }
1802
1803 static int
1804 ftrace_event_set_open(struct inode *inode, struct file *file)
1805 {
1806 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1807 struct trace_array *tr = inode->i_private;
1808 int ret;
1809
1810 if (trace_array_get(tr) < 0)
1811 return -ENODEV;
1812
1813 if ((file->f_mode & FMODE_WRITE) &&
1814 (file->f_flags & O_TRUNC))
1815 ftrace_clear_events(tr);
1816
1817 ret = ftrace_event_open(inode, file, seq_ops);
1818 if (ret < 0)
1819 trace_array_put(tr);
1820 return ret;
1821 }
1822
1823 static int
1824 ftrace_event_set_pid_open(struct inode *inode, struct file *file)
1825 {
1826 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
1827 struct trace_array *tr = inode->i_private;
1828 int ret;
1829
1830 if (trace_array_get(tr) < 0)
1831 return -ENODEV;
1832
1833 if ((file->f_mode & FMODE_WRITE) &&
1834 (file->f_flags & O_TRUNC))
1835 ftrace_clear_event_pids(tr);
1836
1837 ret = ftrace_event_open(inode, file, seq_ops);
1838 if (ret < 0)
1839 trace_array_put(tr);
1840 return ret;
1841 }
1842
1843 static struct event_subsystem *
1844 create_new_subsystem(const char *name)
1845 {
1846 struct event_subsystem *system;
1847
1848 /* need to create new entry */
1849 system = kmalloc(sizeof(*system), GFP_KERNEL);
1850 if (!system)
1851 return NULL;
1852
1853 system->ref_count = 1;
1854
1855 /* Only allocate if dynamic (kprobes and modules) */
1856 system->name = kstrdup_const(name, GFP_KERNEL);
1857 if (!system->name)
1858 goto out_free;
1859
1860 system->filter = NULL;
1861
1862 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1863 if (!system->filter)
1864 goto out_free;
1865
1866 list_add(&system->list, &event_subsystems);
1867
1868 return system;
1869
1870 out_free:
1871 kfree_const(system->name);
1872 kfree(system);
1873 return NULL;
1874 }
1875
1876 static struct dentry *
1877 event_subsystem_dir(struct trace_array *tr, const char *name,
1878 struct trace_event_file *file, struct dentry *parent)
1879 {
1880 struct trace_subsystem_dir *dir;
1881 struct event_subsystem *system;
1882 struct dentry *entry;
1883
1884 /* First see if we did not already create this dir */
1885 list_for_each_entry(dir, &tr->systems, list) {
1886 system = dir->subsystem;
1887 if (strcmp(system->name, name) == 0) {
1888 dir->nr_events++;
1889 file->system = dir;
1890 return dir->entry;
1891 }
1892 }
1893
1894 /* Now see if the system itself exists. */
1895 list_for_each_entry(system, &event_subsystems, list) {
1896 if (strcmp(system->name, name) == 0)
1897 break;
1898 }
1899 /* Reset system variable when not found */
1900 if (&system->list == &event_subsystems)
1901 system = NULL;
1902
1903 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1904 if (!dir)
1905 goto out_fail;
1906
1907 if (!system) {
1908 system = create_new_subsystem(name);
1909 if (!system)
1910 goto out_free;
1911 } else
1912 __get_system(system);
1913
1914 dir->entry = tracefs_create_dir(name, parent);
1915 if (!dir->entry) {
1916 pr_warn("Failed to create system directory %s\n", name);
1917 __put_system(system);
1918 goto out_free;
1919 }
1920
1921 dir->tr = tr;
1922 dir->ref_count = 1;
1923 dir->nr_events = 1;
1924 dir->subsystem = system;
1925 file->system = dir;
1926
1927 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
1928 &ftrace_subsystem_filter_fops);
1929 if (!entry) {
1930 kfree(system->filter);
1931 system->filter = NULL;
1932 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
1933 }
1934
1935 trace_create_file("enable", 0644, dir->entry, dir,
1936 &ftrace_system_enable_fops);
1937
1938 list_add(&dir->list, &tr->systems);
1939
1940 return dir->entry;
1941
1942 out_free:
1943 kfree(dir);
1944 out_fail:
1945 /* Only print this message if failed on memory allocation */
1946 if (!dir || !system)
1947 pr_warn("No memory to create event subsystem %s\n", name);
1948 return NULL;
1949 }
1950
1951 static int
1952 event_create_dir(struct dentry *parent, struct trace_event_file *file)
1953 {
1954 struct trace_event_call *call = file->event_call;
1955 struct trace_array *tr = file->tr;
1956 struct list_head *head;
1957 struct dentry *d_events;
1958 const char *name;
1959 int ret;
1960
1961 /*
1962 * If the trace point header did not define TRACE_SYSTEM
1963 * then the system would be called "TRACE_SYSTEM".
1964 */
1965 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1966 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1967 if (!d_events)
1968 return -ENOMEM;
1969 } else
1970 d_events = parent;
1971
1972 name = trace_event_name(call);
1973 file->dir = tracefs_create_dir(name, d_events);
1974 if (!file->dir) {
1975 pr_warn("Could not create tracefs '%s' directory\n", name);
1976 return -1;
1977 }
1978
1979 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1980 trace_create_file("enable", 0644, file->dir, file,
1981 &ftrace_enable_fops);
1982
1983 #ifdef CONFIG_PERF_EVENTS
1984 if (call->event.type && call->class->reg)
1985 trace_create_file("id", 0444, file->dir,
1986 (void *)(long)call->event.type,
1987 &ftrace_event_id_fops);
1988 #endif
1989
1990 /*
1991 * Other events may have the same class. Only update
1992 * the fields if they are not already defined.
1993 */
1994 head = trace_get_fields(call);
1995 if (list_empty(head)) {
1996 ret = call->class->define_fields(call);
1997 if (ret < 0) {
1998 pr_warn("Could not initialize trace point events/%s\n",
1999 name);
2000 return -1;
2001 }
2002 }
2003 trace_create_file("filter", 0644, file->dir, file,
2004 &ftrace_event_filter_fops);
2005
2006 /*
2007 * Only event directories that can be enabled should have
2008 * triggers.
2009 */
2010 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2011 trace_create_file("trigger", 0644, file->dir, file,
2012 &event_trigger_fops);
2013
2014 #ifdef CONFIG_HIST_TRIGGERS
2015 trace_create_file("hist", 0444, file->dir, file,
2016 &event_hist_fops);
2017 #endif
2018 trace_create_file("format", 0444, file->dir, call,
2019 &ftrace_event_format_fops);
2020
2021 return 0;
2022 }
2023
2024 static void remove_event_from_tracers(struct trace_event_call *call)
2025 {
2026 struct trace_event_file *file;
2027 struct trace_array *tr;
2028
2029 do_for_each_event_file_safe(tr, file) {
2030 if (file->event_call != call)
2031 continue;
2032
2033 remove_event_file_dir(file);
2034 /*
2035 * The do_for_each_event_file_safe() is
2036 * a double loop. After finding the call for this
2037 * trace_array, we use break to jump to the next
2038 * trace_array.
2039 */
2040 break;
2041 } while_for_each_event_file();
2042 }
2043
2044 static void event_remove(struct trace_event_call *call)
2045 {
2046 struct trace_array *tr;
2047 struct trace_event_file *file;
2048
2049 do_for_each_event_file(tr, file) {
2050 if (file->event_call != call)
2051 continue;
2052 ftrace_event_enable_disable(file, 0);
2053 /*
2054 * The do_for_each_event_file() is
2055 * a double loop. After finding the call for this
2056 * trace_array, we use break to jump to the next
2057 * trace_array.
2058 */
2059 break;
2060 } while_for_each_event_file();
2061
2062 if (call->event.funcs)
2063 __unregister_trace_event(&call->event);
2064 remove_event_from_tracers(call);
2065 list_del(&call->list);
2066 }
2067
2068 static int event_init(struct trace_event_call *call)
2069 {
2070 int ret = 0;
2071 const char *name;
2072
2073 name = trace_event_name(call);
2074 if (WARN_ON(!name))
2075 return -EINVAL;
2076
2077 if (call->class->raw_init) {
2078 ret = call->class->raw_init(call);
2079 if (ret < 0 && ret != -ENOSYS)
2080 pr_warn("Could not initialize trace events/%s\n", name);
2081 }
2082
2083 return ret;
2084 }
2085
2086 static int
2087 __register_event(struct trace_event_call *call, struct module *mod)
2088 {
2089 int ret;
2090
2091 ret = event_init(call);
2092 if (ret < 0)
2093 return ret;
2094
2095 list_add(&call->list, &ftrace_events);
2096 call->mod = mod;
2097
2098 return 0;
2099 }
2100
2101 static char *enum_replace(char *ptr, struct trace_enum_map *map, int len)
2102 {
2103 int rlen;
2104 int elen;
2105
2106 /* Find the length of the enum value as a string */
2107 elen = snprintf(ptr, 0, "%ld", map->enum_value);
2108 /* Make sure there's enough room to replace the string with the value */
2109 if (len < elen)
2110 return NULL;
2111
2112 snprintf(ptr, elen + 1, "%ld", map->enum_value);
2113
2114 /* Get the rest of the string of ptr */
2115 rlen = strlen(ptr + len);
2116 memmove(ptr + elen, ptr + len, rlen);
2117 /* Make sure we end the new string */
2118 ptr[elen + rlen] = 0;
2119
2120 return ptr + elen;
2121 }
2122
2123 static void update_event_printk(struct trace_event_call *call,
2124 struct trace_enum_map *map)
2125 {
2126 char *ptr;
2127 int quote = 0;
2128 int len = strlen(map->enum_string);
2129
2130 for (ptr = call->print_fmt; *ptr; ptr++) {
2131 if (*ptr == '\\') {
2132 ptr++;
2133 /* paranoid */
2134 if (!*ptr)
2135 break;
2136 continue;
2137 }
2138 if (*ptr == '"') {
2139 quote ^= 1;
2140 continue;
2141 }
2142 if (quote)
2143 continue;
2144 if (isdigit(*ptr)) {
2145 /* skip numbers */
2146 do {
2147 ptr++;
2148 /* Check for alpha chars like ULL */
2149 } while (isalnum(*ptr));
2150 if (!*ptr)
2151 break;
2152 /*
2153 * A number must have some kind of delimiter after
2154 * it, and we can ignore that too.
2155 */
2156 continue;
2157 }
2158 if (isalpha(*ptr) || *ptr == '_') {
2159 if (strncmp(map->enum_string, ptr, len) == 0 &&
2160 !isalnum(ptr[len]) && ptr[len] != '_') {
2161 ptr = enum_replace(ptr, map, len);
2162 /* Hmm, enum string smaller than value */
2163 if (WARN_ON_ONCE(!ptr))
2164 return;
2165 /*
2166 * No need to decrement here, as enum_replace()
2167 * returns the pointer to the character passed
2168 * the enum, and two enums can not be placed
2169 * back to back without something in between.
2170 * We can skip that something in between.
2171 */
2172 continue;
2173 }
2174 skip_more:
2175 do {
2176 ptr++;
2177 } while (isalnum(*ptr) || *ptr == '_');
2178 if (!*ptr)
2179 break;
2180 /*
2181 * If what comes after this variable is a '.' or
2182 * '->' then we can continue to ignore that string.
2183 */
2184 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2185 ptr += *ptr == '.' ? 1 : 2;
2186 if (!*ptr)
2187 break;
2188 goto skip_more;
2189 }
2190 /*
2191 * Once again, we can skip the delimiter that came
2192 * after the string.
2193 */
2194 continue;
2195 }
2196 }
2197 }
2198
2199 void trace_event_enum_update(struct trace_enum_map **map, int len)
2200 {
2201 struct trace_event_call *call, *p;
2202 const char *last_system = NULL;
2203 int last_i;
2204 int i;
2205
2206 down_write(&trace_event_sem);
2207 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2208 /* events are usually grouped together with systems */
2209 if (!last_system || call->class->system != last_system) {
2210 last_i = 0;
2211 last_system = call->class->system;
2212 }
2213
2214 for (i = last_i; i < len; i++) {
2215 if (call->class->system == map[i]->system) {
2216 /* Save the first system if need be */
2217 if (!last_i)
2218 last_i = i;
2219 update_event_printk(call, map[i]);
2220 }
2221 }
2222 }
2223 up_write(&trace_event_sem);
2224 }
2225
2226 static struct trace_event_file *
2227 trace_create_new_event(struct trace_event_call *call,
2228 struct trace_array *tr)
2229 {
2230 struct trace_event_file *file;
2231
2232 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2233 if (!file)
2234 return NULL;
2235
2236 file->event_call = call;
2237 file->tr = tr;
2238 atomic_set(&file->sm_ref, 0);
2239 atomic_set(&file->tm_ref, 0);
2240 INIT_LIST_HEAD(&file->triggers);
2241 list_add(&file->list, &tr->events);
2242
2243 return file;
2244 }
2245
2246 /* Add an event to a trace directory */
2247 static int
2248 __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2249 {
2250 struct trace_event_file *file;
2251
2252 file = trace_create_new_event(call, tr);
2253 if (!file)
2254 return -ENOMEM;
2255
2256 return event_create_dir(tr->event_dir, file);
2257 }
2258
2259 /*
2260 * Just create a decriptor for early init. A descriptor is required
2261 * for enabling events at boot. We want to enable events before
2262 * the filesystem is initialized.
2263 */
2264 static __init int
2265 __trace_early_add_new_event(struct trace_event_call *call,
2266 struct trace_array *tr)
2267 {
2268 struct trace_event_file *file;
2269
2270 file = trace_create_new_event(call, tr);
2271 if (!file)
2272 return -ENOMEM;
2273
2274 return 0;
2275 }
2276
2277 struct ftrace_module_file_ops;
2278 static void __add_event_to_tracers(struct trace_event_call *call);
2279
2280 /* Add an additional event_call dynamically */
2281 int trace_add_event_call(struct trace_event_call *call)
2282 {
2283 int ret;
2284 mutex_lock(&trace_types_lock);
2285 mutex_lock(&event_mutex);
2286
2287 ret = __register_event(call, NULL);
2288 if (ret >= 0)
2289 __add_event_to_tracers(call);
2290
2291 mutex_unlock(&event_mutex);
2292 mutex_unlock(&trace_types_lock);
2293 return ret;
2294 }
2295
2296 /*
2297 * Must be called under locking of trace_types_lock, event_mutex and
2298 * trace_event_sem.
2299 */
2300 static void __trace_remove_event_call(struct trace_event_call *call)
2301 {
2302 event_remove(call);
2303 trace_destroy_fields(call);
2304 free_event_filter(call->filter);
2305 call->filter = NULL;
2306 }
2307
2308 static int probe_remove_event_call(struct trace_event_call *call)
2309 {
2310 struct trace_array *tr;
2311 struct trace_event_file *file;
2312
2313 #ifdef CONFIG_PERF_EVENTS
2314 if (call->perf_refcount)
2315 return -EBUSY;
2316 #endif
2317 do_for_each_event_file(tr, file) {
2318 if (file->event_call != call)
2319 continue;
2320 /*
2321 * We can't rely on ftrace_event_enable_disable(enable => 0)
2322 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2323 * TRACE_REG_UNREGISTER.
2324 */
2325 if (file->flags & EVENT_FILE_FL_ENABLED)
2326 return -EBUSY;
2327 /*
2328 * The do_for_each_event_file_safe() is
2329 * a double loop. After finding the call for this
2330 * trace_array, we use break to jump to the next
2331 * trace_array.
2332 */
2333 break;
2334 } while_for_each_event_file();
2335
2336 __trace_remove_event_call(call);
2337
2338 return 0;
2339 }
2340
2341 /* Remove an event_call */
2342 int trace_remove_event_call(struct trace_event_call *call)
2343 {
2344 int ret;
2345
2346 mutex_lock(&trace_types_lock);
2347 mutex_lock(&event_mutex);
2348 down_write(&trace_event_sem);
2349 ret = probe_remove_event_call(call);
2350 up_write(&trace_event_sem);
2351 mutex_unlock(&event_mutex);
2352 mutex_unlock(&trace_types_lock);
2353
2354 return ret;
2355 }
2356
2357 #define for_each_event(event, start, end) \
2358 for (event = start; \
2359 (unsigned long)event < (unsigned long)end; \
2360 event++)
2361
2362 #ifdef CONFIG_MODULES
2363
2364 static void trace_module_add_events(struct module *mod)
2365 {
2366 struct trace_event_call **call, **start, **end;
2367
2368 if (!mod->num_trace_events)
2369 return;
2370
2371 /* Don't add infrastructure for mods without tracepoints */
2372 if (trace_module_has_bad_taint(mod)) {
2373 pr_err("%s: module has bad taint, not creating trace events\n",
2374 mod->name);
2375 return;
2376 }
2377
2378 start = mod->trace_events;
2379 end = mod->trace_events + mod->num_trace_events;
2380
2381 for_each_event(call, start, end) {
2382 __register_event(*call, mod);
2383 __add_event_to_tracers(*call);
2384 }
2385 }
2386
2387 static void trace_module_remove_events(struct module *mod)
2388 {
2389 struct trace_event_call *call, *p;
2390 bool clear_trace = false;
2391
2392 down_write(&trace_event_sem);
2393 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2394 if (call->mod == mod) {
2395 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
2396 clear_trace = true;
2397 __trace_remove_event_call(call);
2398 }
2399 }
2400 up_write(&trace_event_sem);
2401
2402 /*
2403 * It is safest to reset the ring buffer if the module being unloaded
2404 * registered any events that were used. The only worry is if
2405 * a new module gets loaded, and takes on the same id as the events
2406 * of this module. When printing out the buffer, traced events left
2407 * over from this module may be passed to the new module events and
2408 * unexpected results may occur.
2409 */
2410 if (clear_trace)
2411 tracing_reset_all_online_cpus();
2412 }
2413
2414 static int trace_module_notify(struct notifier_block *self,
2415 unsigned long val, void *data)
2416 {
2417 struct module *mod = data;
2418
2419 mutex_lock(&trace_types_lock);
2420 mutex_lock(&event_mutex);
2421 switch (val) {
2422 case MODULE_STATE_COMING:
2423 trace_module_add_events(mod);
2424 break;
2425 case MODULE_STATE_GOING:
2426 trace_module_remove_events(mod);
2427 break;
2428 }
2429 mutex_unlock(&event_mutex);
2430 mutex_unlock(&trace_types_lock);
2431
2432 return 0;
2433 }
2434
2435 static struct notifier_block trace_module_nb = {
2436 .notifier_call = trace_module_notify,
2437 .priority = 1, /* higher than trace.c module notify */
2438 };
2439 #endif /* CONFIG_MODULES */
2440
2441 /* Create a new event directory structure for a trace directory. */
2442 static void
2443 __trace_add_event_dirs(struct trace_array *tr)
2444 {
2445 struct trace_event_call *call;
2446 int ret;
2447
2448 list_for_each_entry(call, &ftrace_events, list) {
2449 ret = __trace_add_new_event(call, tr);
2450 if (ret < 0)
2451 pr_warn("Could not create directory for event %s\n",
2452 trace_event_name(call));
2453 }
2454 }
2455
2456 struct trace_event_file *
2457 find_event_file(struct trace_array *tr, const char *system, const char *event)
2458 {
2459 struct trace_event_file *file;
2460 struct trace_event_call *call;
2461 const char *name;
2462
2463 list_for_each_entry(file, &tr->events, list) {
2464
2465 call = file->event_call;
2466 name = trace_event_name(call);
2467
2468 if (!name || !call->class || !call->class->reg)
2469 continue;
2470
2471 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2472 continue;
2473
2474 if (strcmp(event, name) == 0 &&
2475 strcmp(system, call->class->system) == 0)
2476 return file;
2477 }
2478 return NULL;
2479 }
2480
2481 #ifdef CONFIG_DYNAMIC_FTRACE
2482
2483 /* Avoid typos */
2484 #define ENABLE_EVENT_STR "enable_event"
2485 #define DISABLE_EVENT_STR "disable_event"
2486
2487 struct event_probe_data {
2488 struct trace_event_file *file;
2489 unsigned long count;
2490 int ref;
2491 bool enable;
2492 };
2493
2494 static void
2495 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2496 {
2497 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2498 struct event_probe_data *data = *pdata;
2499
2500 if (!data)
2501 return;
2502
2503 if (data->enable)
2504 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2505 else
2506 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2507 }
2508
2509 static void
2510 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2511 {
2512 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2513 struct event_probe_data *data = *pdata;
2514
2515 if (!data)
2516 return;
2517
2518 if (!data->count)
2519 return;
2520
2521 /* Skip if the event is in a state we want to switch to */
2522 if (data->enable == !(data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
2523 return;
2524
2525 if (data->count != -1)
2526 (data->count)--;
2527
2528 event_enable_probe(ip, parent_ip, _data);
2529 }
2530
2531 static int
2532 event_enable_print(struct seq_file *m, unsigned long ip,
2533 struct ftrace_probe_ops *ops, void *_data)
2534 {
2535 struct event_probe_data *data = _data;
2536
2537 seq_printf(m, "%ps:", (void *)ip);
2538
2539 seq_printf(m, "%s:%s:%s",
2540 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2541 data->file->event_call->class->system,
2542 trace_event_name(data->file->event_call));
2543
2544 if (data->count == -1)
2545 seq_puts(m, ":unlimited\n");
2546 else
2547 seq_printf(m, ":count=%ld\n", data->count);
2548
2549 return 0;
2550 }
2551
2552 static int
2553 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
2554 void **_data)
2555 {
2556 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2557 struct event_probe_data *data = *pdata;
2558
2559 data->ref++;
2560 return 0;
2561 }
2562
2563 static void
2564 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
2565 void **_data)
2566 {
2567 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2568 struct event_probe_data *data = *pdata;
2569
2570 if (WARN_ON_ONCE(data->ref <= 0))
2571 return;
2572
2573 data->ref--;
2574 if (!data->ref) {
2575 /* Remove the SOFT_MODE flag */
2576 __ftrace_event_enable_disable(data->file, 0, 1);
2577 module_put(data->file->event_call->mod);
2578 kfree(data);
2579 }
2580 *pdata = NULL;
2581 }
2582
2583 static struct ftrace_probe_ops event_enable_probe_ops = {
2584 .func = event_enable_probe,
2585 .print = event_enable_print,
2586 .init = event_enable_init,
2587 .free = event_enable_free,
2588 };
2589
2590 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2591 .func = event_enable_count_probe,
2592 .print = event_enable_print,
2593 .init = event_enable_init,
2594 .free = event_enable_free,
2595 };
2596
2597 static struct ftrace_probe_ops event_disable_probe_ops = {
2598 .func = event_enable_probe,
2599 .print = event_enable_print,
2600 .init = event_enable_init,
2601 .free = event_enable_free,
2602 };
2603
2604 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2605 .func = event_enable_count_probe,
2606 .print = event_enable_print,
2607 .init = event_enable_init,
2608 .free = event_enable_free,
2609 };
2610
2611 static int
2612 event_enable_func(struct ftrace_hash *hash,
2613 char *glob, char *cmd, char *param, int enabled)
2614 {
2615 struct trace_array *tr = top_trace_array();
2616 struct trace_event_file *file;
2617 struct ftrace_probe_ops *ops;
2618 struct event_probe_data *data;
2619 const char *system;
2620 const char *event;
2621 char *number;
2622 bool enable;
2623 int ret;
2624
2625 if (!tr)
2626 return -ENODEV;
2627
2628 /* hash funcs only work with set_ftrace_filter */
2629 if (!enabled || !param)
2630 return -EINVAL;
2631
2632 system = strsep(&param, ":");
2633 if (!param)
2634 return -EINVAL;
2635
2636 event = strsep(&param, ":");
2637
2638 mutex_lock(&event_mutex);
2639
2640 ret = -EINVAL;
2641 file = find_event_file(tr, system, event);
2642 if (!file)
2643 goto out;
2644
2645 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2646
2647 if (enable)
2648 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2649 else
2650 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2651
2652 if (glob[0] == '!') {
2653 unregister_ftrace_function_probe_func(glob+1, ops);
2654 ret = 0;
2655 goto out;
2656 }
2657
2658 ret = -ENOMEM;
2659 data = kzalloc(sizeof(*data), GFP_KERNEL);
2660 if (!data)
2661 goto out;
2662
2663 data->enable = enable;
2664 data->count = -1;
2665 data->file = file;
2666
2667 if (!param)
2668 goto out_reg;
2669
2670 number = strsep(&param, ":");
2671
2672 ret = -EINVAL;
2673 if (!strlen(number))
2674 goto out_free;
2675
2676 /*
2677 * We use the callback data field (which is a pointer)
2678 * as our counter.
2679 */
2680 ret = kstrtoul(number, 0, &data->count);
2681 if (ret)
2682 goto out_free;
2683
2684 out_reg:
2685 /* Don't let event modules unload while probe registered */
2686 ret = try_module_get(file->event_call->mod);
2687 if (!ret) {
2688 ret = -EBUSY;
2689 goto out_free;
2690 }
2691
2692 ret = __ftrace_event_enable_disable(file, 1, 1);
2693 if (ret < 0)
2694 goto out_put;
2695 ret = register_ftrace_function_probe(glob, ops, data);
2696 /*
2697 * The above returns on success the # of functions enabled,
2698 * but if it didn't find any functions it returns zero.
2699 * Consider no functions a failure too.
2700 */
2701 if (!ret) {
2702 ret = -ENOENT;
2703 goto out_disable;
2704 } else if (ret < 0)
2705 goto out_disable;
2706 /* Just return zero, not the number of enabled functions */
2707 ret = 0;
2708 out:
2709 mutex_unlock(&event_mutex);
2710 return ret;
2711
2712 out_disable:
2713 __ftrace_event_enable_disable(file, 0, 1);
2714 out_put:
2715 module_put(file->event_call->mod);
2716 out_free:
2717 kfree(data);
2718 goto out;
2719 }
2720
2721 static struct ftrace_func_command event_enable_cmd = {
2722 .name = ENABLE_EVENT_STR,
2723 .func = event_enable_func,
2724 };
2725
2726 static struct ftrace_func_command event_disable_cmd = {
2727 .name = DISABLE_EVENT_STR,
2728 .func = event_enable_func,
2729 };
2730
2731 static __init int register_event_cmds(void)
2732 {
2733 int ret;
2734
2735 ret = register_ftrace_command(&event_enable_cmd);
2736 if (WARN_ON(ret < 0))
2737 return ret;
2738 ret = register_ftrace_command(&event_disable_cmd);
2739 if (WARN_ON(ret < 0))
2740 unregister_ftrace_command(&event_enable_cmd);
2741 return ret;
2742 }
2743 #else
2744 static inline int register_event_cmds(void) { return 0; }
2745 #endif /* CONFIG_DYNAMIC_FTRACE */
2746
2747 /*
2748 * The top level array has already had its trace_event_file
2749 * descriptors created in order to allow for early events to
2750 * be recorded. This function is called after the tracefs has been
2751 * initialized, and we now have to create the files associated
2752 * to the events.
2753 */
2754 static __init void
2755 __trace_early_add_event_dirs(struct trace_array *tr)
2756 {
2757 struct trace_event_file *file;
2758 int ret;
2759
2760
2761 list_for_each_entry(file, &tr->events, list) {
2762 ret = event_create_dir(tr->event_dir, file);
2763 if (ret < 0)
2764 pr_warn("Could not create directory for event %s\n",
2765 trace_event_name(file->event_call));
2766 }
2767 }
2768
2769 /*
2770 * For early boot up, the top trace array requires to have
2771 * a list of events that can be enabled. This must be done before
2772 * the filesystem is set up in order to allow events to be traced
2773 * early.
2774 */
2775 static __init void
2776 __trace_early_add_events(struct trace_array *tr)
2777 {
2778 struct trace_event_call *call;
2779 int ret;
2780
2781 list_for_each_entry(call, &ftrace_events, list) {
2782 /* Early boot up should not have any modules loaded */
2783 if (WARN_ON_ONCE(call->mod))
2784 continue;
2785
2786 ret = __trace_early_add_new_event(call, tr);
2787 if (ret < 0)
2788 pr_warn("Could not create early event %s\n",
2789 trace_event_name(call));
2790 }
2791 }
2792
2793 /* Remove the event directory structure for a trace directory. */
2794 static void
2795 __trace_remove_event_dirs(struct trace_array *tr)
2796 {
2797 struct trace_event_file *file, *next;
2798
2799 list_for_each_entry_safe(file, next, &tr->events, list)
2800 remove_event_file_dir(file);
2801 }
2802
2803 static void __add_event_to_tracers(struct trace_event_call *call)
2804 {
2805 struct trace_array *tr;
2806
2807 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2808 __trace_add_new_event(call, tr);
2809 }
2810
2811 extern struct trace_event_call *__start_ftrace_events[];
2812 extern struct trace_event_call *__stop_ftrace_events[];
2813
2814 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2815
2816 static __init int setup_trace_event(char *str)
2817 {
2818 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2819 ring_buffer_expanded = true;
2820 tracing_selftest_disabled = true;
2821
2822 return 1;
2823 }
2824 __setup("trace_event=", setup_trace_event);
2825
2826 /* Expects to have event_mutex held when called */
2827 static int
2828 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2829 {
2830 struct dentry *d_events;
2831 struct dentry *entry;
2832
2833 entry = tracefs_create_file("set_event", 0644, parent,
2834 tr, &ftrace_set_event_fops);
2835 if (!entry) {
2836 pr_warn("Could not create tracefs 'set_event' entry\n");
2837 return -ENOMEM;
2838 }
2839
2840 d_events = tracefs_create_dir("events", parent);
2841 if (!d_events) {
2842 pr_warn("Could not create tracefs 'events' directory\n");
2843 return -ENOMEM;
2844 }
2845
2846 entry = tracefs_create_file("set_event_pid", 0644, parent,
2847 tr, &ftrace_set_event_pid_fops);
2848
2849 /* ring buffer internal formats */
2850 trace_create_file("header_page", 0444, d_events,
2851 ring_buffer_print_page_header,
2852 &ftrace_show_header_fops);
2853
2854 trace_create_file("header_event", 0444, d_events,
2855 ring_buffer_print_entry_header,
2856 &ftrace_show_header_fops);
2857
2858 trace_create_file("enable", 0644, d_events,
2859 tr, &ftrace_tr_enable_fops);
2860
2861 tr->event_dir = d_events;
2862
2863 return 0;
2864 }
2865
2866 /**
2867 * event_trace_add_tracer - add a instance of a trace_array to events
2868 * @parent: The parent dentry to place the files/directories for events in
2869 * @tr: The trace array associated with these events
2870 *
2871 * When a new instance is created, it needs to set up its events
2872 * directory, as well as other files associated with events. It also
2873 * creates the event hierachry in the @parent/events directory.
2874 *
2875 * Returns 0 on success.
2876 */
2877 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2878 {
2879 int ret;
2880
2881 mutex_lock(&event_mutex);
2882
2883 ret = create_event_toplevel_files(parent, tr);
2884 if (ret)
2885 goto out_unlock;
2886
2887 down_write(&trace_event_sem);
2888 __trace_add_event_dirs(tr);
2889 up_write(&trace_event_sem);
2890
2891 out_unlock:
2892 mutex_unlock(&event_mutex);
2893
2894 return ret;
2895 }
2896
2897 /*
2898 * The top trace array already had its file descriptors created.
2899 * Now the files themselves need to be created.
2900 */
2901 static __init int
2902 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2903 {
2904 int ret;
2905
2906 mutex_lock(&event_mutex);
2907
2908 ret = create_event_toplevel_files(parent, tr);
2909 if (ret)
2910 goto out_unlock;
2911
2912 down_write(&trace_event_sem);
2913 __trace_early_add_event_dirs(tr);
2914 up_write(&trace_event_sem);
2915
2916 out_unlock:
2917 mutex_unlock(&event_mutex);
2918
2919 return ret;
2920 }
2921
2922 int event_trace_del_tracer(struct trace_array *tr)
2923 {
2924 mutex_lock(&event_mutex);
2925
2926 /* Disable any event triggers and associated soft-disabled events */
2927 clear_event_triggers(tr);
2928
2929 /* Clear the pid list */
2930 __ftrace_clear_event_pids(tr);
2931
2932 /* Disable any running events */
2933 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
2934
2935 /* Access to events are within rcu_read_lock_sched() */
2936 synchronize_sched();
2937
2938 down_write(&trace_event_sem);
2939 __trace_remove_event_dirs(tr);
2940 tracefs_remove_recursive(tr->event_dir);
2941 up_write(&trace_event_sem);
2942
2943 tr->event_dir = NULL;
2944
2945 mutex_unlock(&event_mutex);
2946
2947 return 0;
2948 }
2949
2950 static __init int event_trace_memsetup(void)
2951 {
2952 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
2953 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
2954 return 0;
2955 }
2956
2957 static __init void
2958 early_enable_events(struct trace_array *tr, bool disable_first)
2959 {
2960 char *buf = bootup_event_buf;
2961 char *token;
2962 int ret;
2963
2964 while (true) {
2965 token = strsep(&buf, ",");
2966
2967 if (!token)
2968 break;
2969
2970 if (*token) {
2971 /* Restarting syscalls requires that we stop them first */
2972 if (disable_first)
2973 ftrace_set_clr_event(tr, token, 0);
2974
2975 ret = ftrace_set_clr_event(tr, token, 1);
2976 if (ret)
2977 pr_warn("Failed to enable trace event: %s\n", token);
2978 }
2979
2980 /* Put back the comma to allow this to be called again */
2981 if (buf)
2982 *(buf - 1) = ',';
2983 }
2984 }
2985
2986 static __init int event_trace_enable(void)
2987 {
2988 struct trace_array *tr = top_trace_array();
2989 struct trace_event_call **iter, *call;
2990 int ret;
2991
2992 if (!tr)
2993 return -ENODEV;
2994
2995 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
2996
2997 call = *iter;
2998 ret = event_init(call);
2999 if (!ret)
3000 list_add(&call->list, &ftrace_events);
3001 }
3002
3003 /*
3004 * We need the top trace array to have a working set of trace
3005 * points at early init, before the debug files and directories
3006 * are created. Create the file entries now, and attach them
3007 * to the actual file dentries later.
3008 */
3009 __trace_early_add_events(tr);
3010
3011 early_enable_events(tr, false);
3012
3013 trace_printk_start_comm();
3014
3015 register_event_cmds();
3016
3017 register_trigger_cmds();
3018
3019 return 0;
3020 }
3021
3022 /*
3023 * event_trace_enable() is called from trace_event_init() first to
3024 * initialize events and perhaps start any events that are on the
3025 * command line. Unfortunately, there are some events that will not
3026 * start this early, like the system call tracepoints that need
3027 * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
3028 * is called before pid 1 starts, and this flag is never set, making
3029 * the syscall tracepoint never get reached, but the event is enabled
3030 * regardless (and not doing anything).
3031 */
3032 static __init int event_trace_enable_again(void)
3033 {
3034 struct trace_array *tr;
3035
3036 tr = top_trace_array();
3037 if (!tr)
3038 return -ENODEV;
3039
3040 early_enable_events(tr, true);
3041
3042 return 0;
3043 }
3044
3045 early_initcall(event_trace_enable_again);
3046
3047 static __init int event_trace_init(void)
3048 {
3049 struct trace_array *tr;
3050 struct dentry *d_tracer;
3051 struct dentry *entry;
3052 int ret;
3053
3054 tr = top_trace_array();
3055 if (!tr)
3056 return -ENODEV;
3057
3058 d_tracer = tracing_init_dentry();
3059 if (IS_ERR(d_tracer))
3060 return 0;
3061
3062 entry = tracefs_create_file("available_events", 0444, d_tracer,
3063 tr, &ftrace_avail_fops);
3064 if (!entry)
3065 pr_warn("Could not create tracefs 'available_events' entry\n");
3066
3067 if (trace_define_generic_fields())
3068 pr_warn("tracing: Failed to allocated generic fields");
3069
3070 if (trace_define_common_fields())
3071 pr_warn("tracing: Failed to allocate common fields");
3072
3073 ret = early_event_add_tracer(d_tracer, tr);
3074 if (ret)
3075 return ret;
3076
3077 #ifdef CONFIG_MODULES
3078 ret = register_module_notifier(&trace_module_nb);
3079 if (ret)
3080 pr_warn("Failed to register trace events module notifier\n");
3081 #endif
3082 return 0;
3083 }
3084
3085 void __init trace_event_init(void)
3086 {
3087 event_trace_memsetup();
3088 init_ftrace_syscalls();
3089 event_trace_enable();
3090 }
3091
3092 fs_initcall(event_trace_init);
3093
3094 #ifdef CONFIG_FTRACE_STARTUP_TEST
3095
3096 static DEFINE_SPINLOCK(test_spinlock);
3097 static DEFINE_SPINLOCK(test_spinlock_irq);
3098 static DEFINE_MUTEX(test_mutex);
3099
3100 static __init void test_work(struct work_struct *dummy)
3101 {
3102 spin_lock(&test_spinlock);
3103 spin_lock_irq(&test_spinlock_irq);
3104 udelay(1);
3105 spin_unlock_irq(&test_spinlock_irq);
3106 spin_unlock(&test_spinlock);
3107
3108 mutex_lock(&test_mutex);
3109 msleep(1);
3110 mutex_unlock(&test_mutex);
3111 }
3112
3113 static __init int event_test_thread(void *unused)
3114 {
3115 void *test_malloc;
3116
3117 test_malloc = kmalloc(1234, GFP_KERNEL);
3118 if (!test_malloc)
3119 pr_info("failed to kmalloc\n");
3120
3121 schedule_on_each_cpu(test_work);
3122
3123 kfree(test_malloc);
3124
3125 set_current_state(TASK_INTERRUPTIBLE);
3126 while (!kthread_should_stop()) {
3127 schedule();
3128 set_current_state(TASK_INTERRUPTIBLE);
3129 }
3130 __set_current_state(TASK_RUNNING);
3131
3132 return 0;
3133 }
3134
3135 /*
3136 * Do various things that may trigger events.
3137 */
3138 static __init void event_test_stuff(void)
3139 {
3140 struct task_struct *test_thread;
3141
3142 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3143 msleep(1);
3144 kthread_stop(test_thread);
3145 }
3146
3147 /*
3148 * For every trace event defined, we will test each trace point separately,
3149 * and then by groups, and finally all trace points.
3150 */
3151 static __init void event_trace_self_tests(void)
3152 {
3153 struct trace_subsystem_dir *dir;
3154 struct trace_event_file *file;
3155 struct trace_event_call *call;
3156 struct event_subsystem *system;
3157 struct trace_array *tr;
3158 int ret;
3159
3160 tr = top_trace_array();
3161 if (!tr)
3162 return;
3163
3164 pr_info("Running tests on trace events:\n");
3165
3166 list_for_each_entry(file, &tr->events, list) {
3167
3168 call = file->event_call;
3169
3170 /* Only test those that have a probe */
3171 if (!call->class || !call->class->probe)
3172 continue;
3173
3174 /*
3175 * Testing syscall events here is pretty useless, but
3176 * we still do it if configured. But this is time consuming.
3177 * What we really need is a user thread to perform the
3178 * syscalls as we test.
3179 */
3180 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3181 if (call->class->system &&
3182 strcmp(call->class->system, "syscalls") == 0)
3183 continue;
3184 #endif
3185
3186 pr_info("Testing event %s: ", trace_event_name(call));
3187
3188 /*
3189 * If an event is already enabled, someone is using
3190 * it and the self test should not be on.
3191 */
3192 if (file->flags & EVENT_FILE_FL_ENABLED) {
3193 pr_warn("Enabled event during self test!\n");
3194 WARN_ON_ONCE(1);
3195 continue;
3196 }
3197
3198 ftrace_event_enable_disable(file, 1);
3199 event_test_stuff();
3200 ftrace_event_enable_disable(file, 0);
3201
3202 pr_cont("OK\n");
3203 }
3204
3205 /* Now test at the sub system level */
3206
3207 pr_info("Running tests on trace event systems:\n");
3208
3209 list_for_each_entry(dir, &tr->systems, list) {
3210
3211 system = dir->subsystem;
3212
3213 /* the ftrace system is special, skip it */
3214 if (strcmp(system->name, "ftrace") == 0)
3215 continue;
3216
3217 pr_info("Testing event system %s: ", system->name);
3218
3219 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3220 if (WARN_ON_ONCE(ret)) {
3221 pr_warn("error enabling system %s\n",
3222 system->name);
3223 continue;
3224 }
3225
3226 event_test_stuff();
3227
3228 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3229 if (WARN_ON_ONCE(ret)) {
3230 pr_warn("error disabling system %s\n",
3231 system->name);
3232 continue;
3233 }
3234
3235 pr_cont("OK\n");
3236 }
3237
3238 /* Test with all events enabled */
3239
3240 pr_info("Running tests on all trace events:\n");
3241 pr_info("Testing all events: ");
3242
3243 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3244 if (WARN_ON_ONCE(ret)) {
3245 pr_warn("error enabling all events\n");
3246 return;
3247 }
3248
3249 event_test_stuff();
3250
3251 /* reset sysname */
3252 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3253 if (WARN_ON_ONCE(ret)) {
3254 pr_warn("error disabling all events\n");
3255 return;
3256 }
3257
3258 pr_cont("OK\n");
3259 }
3260
3261 #ifdef CONFIG_FUNCTION_TRACER
3262
3263 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3264
3265 static struct trace_event_file event_trace_file __initdata;
3266
3267 static void __init
3268 function_test_events_call(unsigned long ip, unsigned long parent_ip,
3269 struct ftrace_ops *op, struct pt_regs *pt_regs)
3270 {
3271 struct ring_buffer_event *event;
3272 struct ring_buffer *buffer;
3273 struct ftrace_entry *entry;
3274 unsigned long flags;
3275 long disabled;
3276 int cpu;
3277 int pc;
3278
3279 pc = preempt_count();
3280 preempt_disable_notrace();
3281 cpu = raw_smp_processor_id();
3282 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3283
3284 if (disabled != 1)
3285 goto out;
3286
3287 local_save_flags(flags);
3288
3289 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
3290 TRACE_FN, sizeof(*entry),
3291 flags, pc);
3292 if (!event)
3293 goto out;
3294 entry = ring_buffer_event_data(event);
3295 entry->ip = ip;
3296 entry->parent_ip = parent_ip;
3297
3298 event_trigger_unlock_commit(&event_trace_file, buffer, event,
3299 entry, flags, pc);
3300 out:
3301 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3302 preempt_enable_notrace();
3303 }
3304
3305 static struct ftrace_ops trace_ops __initdata =
3306 {
3307 .func = function_test_events_call,
3308 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
3309 };
3310
3311 static __init void event_trace_self_test_with_function(void)
3312 {
3313 int ret;
3314
3315 event_trace_file.tr = top_trace_array();
3316 if (WARN_ON(!event_trace_file.tr))
3317 return;
3318
3319 ret = register_ftrace_function(&trace_ops);
3320 if (WARN_ON(ret < 0)) {
3321 pr_info("Failed to enable function tracer for event tests\n");
3322 return;
3323 }
3324 pr_info("Running tests again, along with the function tracer\n");
3325 event_trace_self_tests();
3326 unregister_ftrace_function(&trace_ops);
3327 }
3328 #else
3329 static __init void event_trace_self_test_with_function(void)
3330 {
3331 }
3332 #endif
3333
3334 static __init int event_trace_self_tests_init(void)
3335 {
3336 if (!tracing_selftest_disabled) {
3337 event_trace_self_tests();
3338 event_trace_self_test_with_function();
3339 }
3340
3341 return 0;
3342 }
3343
3344 late_initcall(event_trace_self_tests_init);
3345
3346 #endif
Linux kernel - Deliverables
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