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ftrace: Added ftrace_func_mapper for function probe triggers
[linux/fpc-iii.git] / kernel / trace / trace_events.c
blobee308312fe87ba105088f4dcf42ef8ca3629c3a5
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 static int __ftrace_event_enable_disable(struct trace_event_file *file,
347 int enable, int soft_disable)
348 {
349 struct trace_event_call *call = file->event_call;
350 struct trace_array *tr = file->tr;
351 unsigned long file_flags = file->flags;
352 int ret = 0;
353 int disable;
354
355 switch (enable) {
356 case 0:
357 /*
358 * When soft_disable is set and enable is cleared, the sm_ref
359 * reference counter is decremented. If it reaches 0, we want
360 * to clear the SOFT_DISABLED flag but leave the event in the
361 * state that it was. That is, if the event was enabled and
362 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
363 * is set we do not want the event to be enabled before we
364 * clear the bit.
365 *
366 * When soft_disable is not set but the SOFT_MODE flag is,
367 * we do nothing. Do not disable the tracepoint, otherwise
368 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
369 */
370 if (soft_disable) {
371 if (atomic_dec_return(&file->sm_ref) > 0)
372 break;
373 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
374 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
375 } else
376 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
377
378 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
379 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
380 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
381 tracing_stop_cmdline_record();
382 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
383 }
384 call->class->reg(call, TRACE_REG_UNREGISTER, file);
385 }
386 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
387 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
388 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
389 else
390 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
391 break;
392 case 1:
393 /*
394 * When soft_disable is set and enable is set, we want to
395 * register the tracepoint for the event, but leave the event
396 * as is. That means, if the event was already enabled, we do
397 * nothing (but set SOFT_MODE). If the event is disabled, we
398 * set SOFT_DISABLED before enabling the event tracepoint, so
399 * it still seems to be disabled.
400 */
401 if (!soft_disable)
402 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
403 else {
404 if (atomic_inc_return(&file->sm_ref) > 1)
405 break;
406 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
407 }
408
409 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
410
411 /* Keep the event disabled, when going to SOFT_MODE. */
412 if (soft_disable)
413 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
414
415 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
416 tracing_start_cmdline_record();
417 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
418 }
419 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
420 if (ret) {
421 tracing_stop_cmdline_record();
422 pr_info("event trace: Could not enable event "
423 "%s\n", trace_event_name(call));
424 break;
425 }
426 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
427
428 /* WAS_ENABLED gets set but never cleared. */
429 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
430 }
431 break;
432 }
433
434 /* Enable or disable use of trace_buffered_event */
435 if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) !=
436 (file->flags & EVENT_FILE_FL_SOFT_DISABLED)) {
437 if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
438 trace_buffered_event_enable();
439 else
440 trace_buffered_event_disable();
441 }
442
443 return ret;
444 }
445
446 int trace_event_enable_disable(struct trace_event_file *file,
447 int enable, int soft_disable)
448 {
449 return __ftrace_event_enable_disable(file, enable, soft_disable);
450 }
451
452 static int ftrace_event_enable_disable(struct trace_event_file *file,
453 int enable)
454 {
455 return __ftrace_event_enable_disable(file, enable, 0);
456 }
457
458 static void ftrace_clear_events(struct trace_array *tr)
459 {
460 struct trace_event_file *file;
461
462 mutex_lock(&event_mutex);
463 list_for_each_entry(file, &tr->events, list) {
464 ftrace_event_enable_disable(file, 0);
465 }
466 mutex_unlock(&event_mutex);
467 }
468
469 static void
470 event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
471 {
472 struct trace_pid_list *pid_list;
473 struct trace_array *tr = data;
474
475 pid_list = rcu_dereference_sched(tr->filtered_pids);
476 trace_filter_add_remove_task(pid_list, NULL, task);
477 }
478
479 static void
480 event_filter_pid_sched_process_fork(void *data,
481 struct task_struct *self,
482 struct task_struct *task)
483 {
484 struct trace_pid_list *pid_list;
485 struct trace_array *tr = data;
486
487 pid_list = rcu_dereference_sched(tr->filtered_pids);
488 trace_filter_add_remove_task(pid_list, self, task);
489 }
490
491 void trace_event_follow_fork(struct trace_array *tr, bool enable)
492 {
493 if (enable) {
494 register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
495 tr, INT_MIN);
496 register_trace_prio_sched_process_exit(event_filter_pid_sched_process_exit,
497 tr, INT_MAX);
498 } else {
499 unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
500 tr);
501 unregister_trace_sched_process_exit(event_filter_pid_sched_process_exit,
502 tr);
503 }
504 }
505
506 static void
507 event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
508 struct task_struct *prev, struct task_struct *next)
509 {
510 struct trace_array *tr = data;
511 struct trace_pid_list *pid_list;
512
513 pid_list = rcu_dereference_sched(tr->filtered_pids);
514
515 this_cpu_write(tr->trace_buffer.data->ignore_pid,
516 trace_ignore_this_task(pid_list, prev) &&
517 trace_ignore_this_task(pid_list, next));
518 }
519
520 static void
521 event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
522 struct task_struct *prev, struct task_struct *next)
523 {
524 struct trace_array *tr = data;
525 struct trace_pid_list *pid_list;
526
527 pid_list = rcu_dereference_sched(tr->filtered_pids);
528
529 this_cpu_write(tr->trace_buffer.data->ignore_pid,
530 trace_ignore_this_task(pid_list, next));
531 }
532
533 static void
534 event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
535 {
536 struct trace_array *tr = data;
537 struct trace_pid_list *pid_list;
538
539 /* Nothing to do if we are already tracing */
540 if (!this_cpu_read(tr->trace_buffer.data->ignore_pid))
541 return;
542
543 pid_list = rcu_dereference_sched(tr->filtered_pids);
544
545 this_cpu_write(tr->trace_buffer.data->ignore_pid,
546 trace_ignore_this_task(pid_list, task));
547 }
548
549 static void
550 event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
551 {
552 struct trace_array *tr = data;
553 struct trace_pid_list *pid_list;
554
555 /* Nothing to do if we are not tracing */
556 if (this_cpu_read(tr->trace_buffer.data->ignore_pid))
557 return;
558
559 pid_list = rcu_dereference_sched(tr->filtered_pids);
560
561 /* Set tracing if current is enabled */
562 this_cpu_write(tr->trace_buffer.data->ignore_pid,
563 trace_ignore_this_task(pid_list, current));
564 }
565
566 static void __ftrace_clear_event_pids(struct trace_array *tr)
567 {
568 struct trace_pid_list *pid_list;
569 struct trace_event_file *file;
570 int cpu;
571
572 pid_list = rcu_dereference_protected(tr->filtered_pids,
573 lockdep_is_held(&event_mutex));
574 if (!pid_list)
575 return;
576
577 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
578 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
579
580 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
581 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
582
583 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
584 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
585
586 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
587 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
588
589 list_for_each_entry(file, &tr->events, list) {
590 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
591 }
592
593 for_each_possible_cpu(cpu)
594 per_cpu_ptr(tr->trace_buffer.data, cpu)->ignore_pid = false;
595
596 rcu_assign_pointer(tr->filtered_pids, NULL);
597
598 /* Wait till all users are no longer using pid filtering */
599 synchronize_sched();
600
601 trace_free_pid_list(pid_list);
602 }
603
604 static void ftrace_clear_event_pids(struct trace_array *tr)
605 {
606 mutex_lock(&event_mutex);
607 __ftrace_clear_event_pids(tr);
608 mutex_unlock(&event_mutex);
609 }
610
611 static void __put_system(struct event_subsystem *system)
612 {
613 struct event_filter *filter = system->filter;
614
615 WARN_ON_ONCE(system_refcount(system) == 0);
616 if (system_refcount_dec(system))
617 return;
618
619 list_del(&system->list);
620
621 if (filter) {
622 kfree(filter->filter_string);
623 kfree(filter);
624 }
625 kfree_const(system->name);
626 kfree(system);
627 }
628
629 static void __get_system(struct event_subsystem *system)
630 {
631 WARN_ON_ONCE(system_refcount(system) == 0);
632 system_refcount_inc(system);
633 }
634
635 static void __get_system_dir(struct trace_subsystem_dir *dir)
636 {
637 WARN_ON_ONCE(dir->ref_count == 0);
638 dir->ref_count++;
639 __get_system(dir->subsystem);
640 }
641
642 static void __put_system_dir(struct trace_subsystem_dir *dir)
643 {
644 WARN_ON_ONCE(dir->ref_count == 0);
645 /* If the subsystem is about to be freed, the dir must be too */
646 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
647
648 __put_system(dir->subsystem);
649 if (!--dir->ref_count)
650 kfree(dir);
651 }
652
653 static void put_system(struct trace_subsystem_dir *dir)
654 {
655 mutex_lock(&event_mutex);
656 __put_system_dir(dir);
657 mutex_unlock(&event_mutex);
658 }
659
660 static void remove_subsystem(struct trace_subsystem_dir *dir)
661 {
662 if (!dir)
663 return;
664
665 if (!--dir->nr_events) {
666 tracefs_remove_recursive(dir->entry);
667 list_del(&dir->list);
668 __put_system_dir(dir);
669 }
670 }
671
672 static void remove_event_file_dir(struct trace_event_file *file)
673 {
674 struct dentry *dir = file->dir;
675 struct dentry *child;
676
677 if (dir) {
678 spin_lock(&dir->d_lock); /* probably unneeded */
679 list_for_each_entry(child, &dir->d_subdirs, d_child) {
680 if (d_really_is_positive(child)) /* probably unneeded */
681 d_inode(child)->i_private = NULL;
682 }
683 spin_unlock(&dir->d_lock);
684
685 tracefs_remove_recursive(dir);
686 }
687
688 list_del(&file->list);
689 remove_subsystem(file->system);
690 free_event_filter(file->filter);
691 kmem_cache_free(file_cachep, file);
692 }
693
694 /*
695 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
696 */
697 static int
698 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
699 const char *sub, const char *event, int set)
700 {
701 struct trace_event_file *file;
702 struct trace_event_call *call;
703 const char *name;
704 int ret = -EINVAL;
705 int eret = 0;
706
707 list_for_each_entry(file, &tr->events, list) {
708
709 call = file->event_call;
710 name = trace_event_name(call);
711
712 if (!name || !call->class || !call->class->reg)
713 continue;
714
715 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
716 continue;
717
718 if (match &&
719 strcmp(match, name) != 0 &&
720 strcmp(match, call->class->system) != 0)
721 continue;
722
723 if (sub && strcmp(sub, call->class->system) != 0)
724 continue;
725
726 if (event && strcmp(event, name) != 0)
727 continue;
728
729 ret = ftrace_event_enable_disable(file, set);
730
731 /*
732 * Save the first error and return that. Some events
733 * may still have been enabled, but let the user
734 * know that something went wrong.
735 */
736 if (ret && !eret)
737 eret = ret;
738
739 ret = eret;
740 }
741
742 return ret;
743 }
744
745 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
746 const char *sub, const char *event, int set)
747 {
748 int ret;
749
750 mutex_lock(&event_mutex);
751 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
752 mutex_unlock(&event_mutex);
753
754 return ret;
755 }
756
757 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
758 {
759 char *event = NULL, *sub = NULL, *match;
760 int ret;
761
762 /*
763 * The buf format can be <subsystem>:<event-name>
764 * *:<event-name> means any event by that name.
765 * :<event-name> is the same.
766 *
767 * <subsystem>:* means all events in that subsystem
768 * <subsystem>: means the same.
769 *
770 * <name> (no ':') means all events in a subsystem with
771 * the name <name> or any event that matches <name>
772 */
773
774 match = strsep(&buf, ":");
775 if (buf) {
776 sub = match;
777 event = buf;
778 match = NULL;
779
780 if (!strlen(sub) || strcmp(sub, "*") == 0)
781 sub = NULL;
782 if (!strlen(event) || strcmp(event, "*") == 0)
783 event = NULL;
784 }
785
786 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
787
788 /* Put back the colon to allow this to be called again */
789 if (buf)
790 *(buf - 1) = ':';
791
792 return ret;
793 }
794
795 /**
796 * trace_set_clr_event - enable or disable an event
797 * @system: system name to match (NULL for any system)
798 * @event: event name to match (NULL for all events, within system)
799 * @set: 1 to enable, 0 to disable
800 *
801 * This is a way for other parts of the kernel to enable or disable
802 * event recording.
803 *
804 * Returns 0 on success, -EINVAL if the parameters do not match any
805 * registered events.
806 */
807 int trace_set_clr_event(const char *system, const char *event, int set)
808 {
809 struct trace_array *tr = top_trace_array();
810
811 if (!tr)
812 return -ENODEV;
813
814 return __ftrace_set_clr_event(tr, NULL, system, event, set);
815 }
816 EXPORT_SYMBOL_GPL(trace_set_clr_event);
817
818 /* 128 should be much more than enough */
819 #define EVENT_BUF_SIZE 127
820
821 static ssize_t
822 ftrace_event_write(struct file *file, const char __user *ubuf,
823 size_t cnt, loff_t *ppos)
824 {
825 struct trace_parser parser;
826 struct seq_file *m = file->private_data;
827 struct trace_array *tr = m->private;
828 ssize_t read, ret;
829
830 if (!cnt)
831 return 0;
832
833 ret = tracing_update_buffers();
834 if (ret < 0)
835 return ret;
836
837 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
838 return -ENOMEM;
839
840 read = trace_get_user(&parser, ubuf, cnt, ppos);
841
842 if (read >= 0 && trace_parser_loaded((&parser))) {
843 int set = 1;
844
845 if (*parser.buffer == '!')
846 set = 0;
847
848 parser.buffer[parser.idx] = 0;
849
850 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
851 if (ret)
852 goto out_put;
853 }
854
855 ret = read;
856
857 out_put:
858 trace_parser_put(&parser);
859
860 return ret;
861 }
862
863 static void *
864 t_next(struct seq_file *m, void *v, loff_t *pos)
865 {
866 struct trace_event_file *file = v;
867 struct trace_event_call *call;
868 struct trace_array *tr = m->private;
869
870 (*pos)++;
871
872 list_for_each_entry_continue(file, &tr->events, list) {
873 call = file->event_call;
874 /*
875 * The ftrace subsystem is for showing formats only.
876 * They can not be enabled or disabled via the event files.
877 */
878 if (call->class && call->class->reg &&
879 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
880 return file;
881 }
882
883 return NULL;
884 }
885
886 static void *t_start(struct seq_file *m, loff_t *pos)
887 {
888 struct trace_event_file *file;
889 struct trace_array *tr = m->private;
890 loff_t l;
891
892 mutex_lock(&event_mutex);
893
894 file = list_entry(&tr->events, struct trace_event_file, list);
895 for (l = 0; l <= *pos; ) {
896 file = t_next(m, file, &l);
897 if (!file)
898 break;
899 }
900 return file;
901 }
902
903 static void *
904 s_next(struct seq_file *m, void *v, loff_t *pos)
905 {
906 struct trace_event_file *file = v;
907 struct trace_array *tr = m->private;
908
909 (*pos)++;
910
911 list_for_each_entry_continue(file, &tr->events, list) {
912 if (file->flags & EVENT_FILE_FL_ENABLED)
913 return file;
914 }
915
916 return NULL;
917 }
918
919 static void *s_start(struct seq_file *m, loff_t *pos)
920 {
921 struct trace_event_file *file;
922 struct trace_array *tr = m->private;
923 loff_t l;
924
925 mutex_lock(&event_mutex);
926
927 file = list_entry(&tr->events, struct trace_event_file, list);
928 for (l = 0; l <= *pos; ) {
929 file = s_next(m, file, &l);
930 if (!file)
931 break;
932 }
933 return file;
934 }
935
936 static int t_show(struct seq_file *m, void *v)
937 {
938 struct trace_event_file *file = v;
939 struct trace_event_call *call = file->event_call;
940
941 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
942 seq_printf(m, "%s:", call->class->system);
943 seq_printf(m, "%s\n", trace_event_name(call));
944
945 return 0;
946 }
947
948 static void t_stop(struct seq_file *m, void *p)
949 {
950 mutex_unlock(&event_mutex);
951 }
952
953 static void *
954 p_next(struct seq_file *m, void *v, loff_t *pos)
955 {
956 struct trace_array *tr = m->private;
957 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
958
959 return trace_pid_next(pid_list, v, pos);
960 }
961
962 static void *p_start(struct seq_file *m, loff_t *pos)
963 __acquires(RCU)
964 {
965 struct trace_pid_list *pid_list;
966 struct trace_array *tr = m->private;
967
968 /*
969 * Grab the mutex, to keep calls to p_next() having the same
970 * tr->filtered_pids as p_start() has.
971 * If we just passed the tr->filtered_pids around, then RCU would
972 * have been enough, but doing that makes things more complex.
973 */
974 mutex_lock(&event_mutex);
975 rcu_read_lock_sched();
976
977 pid_list = rcu_dereference_sched(tr->filtered_pids);
978
979 if (!pid_list)
980 return NULL;
981
982 return trace_pid_start(pid_list, pos);
983 }
984
985 static void p_stop(struct seq_file *m, void *p)
986 __releases(RCU)
987 {
988 rcu_read_unlock_sched();
989 mutex_unlock(&event_mutex);
990 }
991
992 static ssize_t
993 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
994 loff_t *ppos)
995 {
996 struct trace_event_file *file;
997 unsigned long flags;
998 char buf[4] = "0";
999
1000 mutex_lock(&event_mutex);
1001 file = event_file_data(filp);
1002 if (likely(file))
1003 flags = file->flags;
1004 mutex_unlock(&event_mutex);
1005
1006 if (!file)
1007 return -ENODEV;
1008
1009 if (flags & EVENT_FILE_FL_ENABLED &&
1010 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1011 strcpy(buf, "1");
1012
1013 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1014 flags & EVENT_FILE_FL_SOFT_MODE)
1015 strcat(buf, "*");
1016
1017 strcat(buf, "\n");
1018
1019 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1020 }
1021
1022 static ssize_t
1023 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1024 loff_t *ppos)
1025 {
1026 struct trace_event_file *file;
1027 unsigned long val;
1028 int ret;
1029
1030 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1031 if (ret)
1032 return ret;
1033
1034 ret = tracing_update_buffers();
1035 if (ret < 0)
1036 return ret;
1037
1038 switch (val) {
1039 case 0:
1040 case 1:
1041 ret = -ENODEV;
1042 mutex_lock(&event_mutex);
1043 file = event_file_data(filp);
1044 if (likely(file))
1045 ret = ftrace_event_enable_disable(file, val);
1046 mutex_unlock(&event_mutex);
1047 break;
1048
1049 default:
1050 return -EINVAL;
1051 }
1052
1053 *ppos += cnt;
1054
1055 return ret ? ret : cnt;
1056 }
1057
1058 static ssize_t
1059 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1060 loff_t *ppos)
1061 {
1062 const char set_to_char[4] = { '?', '0', '1', 'X' };
1063 struct trace_subsystem_dir *dir = filp->private_data;
1064 struct event_subsystem *system = dir->subsystem;
1065 struct trace_event_call *call;
1066 struct trace_event_file *file;
1067 struct trace_array *tr = dir->tr;
1068 char buf[2];
1069 int set = 0;
1070 int ret;
1071
1072 mutex_lock(&event_mutex);
1073 list_for_each_entry(file, &tr->events, list) {
1074 call = file->event_call;
1075 if (!trace_event_name(call) || !call->class || !call->class->reg)
1076 continue;
1077
1078 if (system && strcmp(call->class->system, system->name) != 0)
1079 continue;
1080
1081 /*
1082 * We need to find out if all the events are set
1083 * or if all events or cleared, or if we have
1084 * a mixture.
1085 */
1086 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1087
1088 /*
1089 * If we have a mixture, no need to look further.
1090 */
1091 if (set == 3)
1092 break;
1093 }
1094 mutex_unlock(&event_mutex);
1095
1096 buf[0] = set_to_char[set];
1097 buf[1] = '\n';
1098
1099 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1100
1101 return ret;
1102 }
1103
1104 static ssize_t
1105 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1106 loff_t *ppos)
1107 {
1108 struct trace_subsystem_dir *dir = filp->private_data;
1109 struct event_subsystem *system = dir->subsystem;
1110 const char *name = NULL;
1111 unsigned long val;
1112 ssize_t ret;
1113
1114 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1115 if (ret)
1116 return ret;
1117
1118 ret = tracing_update_buffers();
1119 if (ret < 0)
1120 return ret;
1121
1122 if (val != 0 && val != 1)
1123 return -EINVAL;
1124
1125 /*
1126 * Opening of "enable" adds a ref count to system,
1127 * so the name is safe to use.
1128 */
1129 if (system)
1130 name = system->name;
1131
1132 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1133 if (ret)
1134 goto out;
1135
1136 ret = cnt;
1137
1138 out:
1139 *ppos += cnt;
1140
1141 return ret;
1142 }
1143
1144 enum {
1145 FORMAT_HEADER = 1,
1146 FORMAT_FIELD_SEPERATOR = 2,
1147 FORMAT_PRINTFMT = 3,
1148 };
1149
1150 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1151 {
1152 struct trace_event_call *call = event_file_data(m->private);
1153 struct list_head *common_head = &ftrace_common_fields;
1154 struct list_head *head = trace_get_fields(call);
1155 struct list_head *node = v;
1156
1157 (*pos)++;
1158
1159 switch ((unsigned long)v) {
1160 case FORMAT_HEADER:
1161 node = common_head;
1162 break;
1163
1164 case FORMAT_FIELD_SEPERATOR:
1165 node = head;
1166 break;
1167
1168 case FORMAT_PRINTFMT:
1169 /* all done */
1170 return NULL;
1171 }
1172
1173 node = node->prev;
1174 if (node == common_head)
1175 return (void *)FORMAT_FIELD_SEPERATOR;
1176 else if (node == head)
1177 return (void *)FORMAT_PRINTFMT;
1178 else
1179 return node;
1180 }
1181
1182 static int f_show(struct seq_file *m, void *v)
1183 {
1184 struct trace_event_call *call = event_file_data(m->private);
1185 struct ftrace_event_field *field;
1186 const char *array_descriptor;
1187
1188 switch ((unsigned long)v) {
1189 case FORMAT_HEADER:
1190 seq_printf(m, "name: %s\n", trace_event_name(call));
1191 seq_printf(m, "ID: %d\n", call->event.type);
1192 seq_puts(m, "format:\n");
1193 return 0;
1194
1195 case FORMAT_FIELD_SEPERATOR:
1196 seq_putc(m, '\n');
1197 return 0;
1198
1199 case FORMAT_PRINTFMT:
1200 seq_printf(m, "\nprint fmt: %s\n",
1201 call->print_fmt);
1202 return 0;
1203 }
1204
1205 field = list_entry(v, struct ftrace_event_field, link);
1206 /*
1207 * Smartly shows the array type(except dynamic array).
1208 * Normal:
1209 * field:TYPE VAR
1210 * If TYPE := TYPE[LEN], it is shown:
1211 * field:TYPE VAR[LEN]
1212 */
1213 array_descriptor = strchr(field->type, '[');
1214
1215 if (!strncmp(field->type, "__data_loc", 10))
1216 array_descriptor = NULL;
1217
1218 if (!array_descriptor)
1219 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1220 field->type, field->name, field->offset,
1221 field->size, !!field->is_signed);
1222 else
1223 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1224 (int)(array_descriptor - field->type),
1225 field->type, field->name,
1226 array_descriptor, field->offset,
1227 field->size, !!field->is_signed);
1228
1229 return 0;
1230 }
1231
1232 static void *f_start(struct seq_file *m, loff_t *pos)
1233 {
1234 void *p = (void *)FORMAT_HEADER;
1235 loff_t l = 0;
1236
1237 /* ->stop() is called even if ->start() fails */
1238 mutex_lock(&event_mutex);
1239 if (!event_file_data(m->private))
1240 return ERR_PTR(-ENODEV);
1241
1242 while (l < *pos && p)
1243 p = f_next(m, p, &l);
1244
1245 return p;
1246 }
1247
1248 static void f_stop(struct seq_file *m, void *p)
1249 {
1250 mutex_unlock(&event_mutex);
1251 }
1252
1253 static const struct seq_operations trace_format_seq_ops = {
1254 .start = f_start,
1255 .next = f_next,
1256 .stop = f_stop,
1257 .show = f_show,
1258 };
1259
1260 static int trace_format_open(struct inode *inode, struct file *file)
1261 {
1262 struct seq_file *m;
1263 int ret;
1264
1265 ret = seq_open(file, &trace_format_seq_ops);
1266 if (ret < 0)
1267 return ret;
1268
1269 m = file->private_data;
1270 m->private = file;
1271
1272 return 0;
1273 }
1274
1275 static ssize_t
1276 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1277 {
1278 int id = (long)event_file_data(filp);
1279 char buf[32];
1280 int len;
1281
1282 if (*ppos)
1283 return 0;
1284
1285 if (unlikely(!id))
1286 return -ENODEV;
1287
1288 len = sprintf(buf, "%d\n", id);
1289
1290 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1291 }
1292
1293 static ssize_t
1294 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1295 loff_t *ppos)
1296 {
1297 struct trace_event_file *file;
1298 struct trace_seq *s;
1299 int r = -ENODEV;
1300
1301 if (*ppos)
1302 return 0;
1303
1304 s = kmalloc(sizeof(*s), GFP_KERNEL);
1305
1306 if (!s)
1307 return -ENOMEM;
1308
1309 trace_seq_init(s);
1310
1311 mutex_lock(&event_mutex);
1312 file = event_file_data(filp);
1313 if (file)
1314 print_event_filter(file, s);
1315 mutex_unlock(&event_mutex);
1316
1317 if (file)
1318 r = simple_read_from_buffer(ubuf, cnt, ppos,
1319 s->buffer, trace_seq_used(s));
1320
1321 kfree(s);
1322
1323 return r;
1324 }
1325
1326 static ssize_t
1327 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1328 loff_t *ppos)
1329 {
1330 struct trace_event_file *file;
1331 char *buf;
1332 int err = -ENODEV;
1333
1334 if (cnt >= PAGE_SIZE)
1335 return -EINVAL;
1336
1337 buf = memdup_user_nul(ubuf, cnt);
1338 if (IS_ERR(buf))
1339 return PTR_ERR(buf);
1340
1341 mutex_lock(&event_mutex);
1342 file = event_file_data(filp);
1343 if (file)
1344 err = apply_event_filter(file, buf);
1345 mutex_unlock(&event_mutex);
1346
1347 kfree(buf);
1348 if (err < 0)
1349 return err;
1350
1351 *ppos += cnt;
1352
1353 return cnt;
1354 }
1355
1356 static LIST_HEAD(event_subsystems);
1357
1358 static int subsystem_open(struct inode *inode, struct file *filp)
1359 {
1360 struct event_subsystem *system = NULL;
1361 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1362 struct trace_array *tr;
1363 int ret;
1364
1365 if (tracing_is_disabled())
1366 return -ENODEV;
1367
1368 /* Make sure the system still exists */
1369 mutex_lock(&trace_types_lock);
1370 mutex_lock(&event_mutex);
1371 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1372 list_for_each_entry(dir, &tr->systems, list) {
1373 if (dir == inode->i_private) {
1374 /* Don't open systems with no events */
1375 if (dir->nr_events) {
1376 __get_system_dir(dir);
1377 system = dir->subsystem;
1378 }
1379 goto exit_loop;
1380 }
1381 }
1382 }
1383 exit_loop:
1384 mutex_unlock(&event_mutex);
1385 mutex_unlock(&trace_types_lock);
1386
1387 if (!system)
1388 return -ENODEV;
1389
1390 /* Some versions of gcc think dir can be uninitialized here */
1391 WARN_ON(!dir);
1392
1393 /* Still need to increment the ref count of the system */
1394 if (trace_array_get(tr) < 0) {
1395 put_system(dir);
1396 return -ENODEV;
1397 }
1398
1399 ret = tracing_open_generic(inode, filp);
1400 if (ret < 0) {
1401 trace_array_put(tr);
1402 put_system(dir);
1403 }
1404
1405 return ret;
1406 }
1407
1408 static int system_tr_open(struct inode *inode, struct file *filp)
1409 {
1410 struct trace_subsystem_dir *dir;
1411 struct trace_array *tr = inode->i_private;
1412 int ret;
1413
1414 if (tracing_is_disabled())
1415 return -ENODEV;
1416
1417 if (trace_array_get(tr) < 0)
1418 return -ENODEV;
1419
1420 /* Make a temporary dir that has no system but points to tr */
1421 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1422 if (!dir) {
1423 trace_array_put(tr);
1424 return -ENOMEM;
1425 }
1426
1427 dir->tr = tr;
1428
1429 ret = tracing_open_generic(inode, filp);
1430 if (ret < 0) {
1431 trace_array_put(tr);
1432 kfree(dir);
1433 return ret;
1434 }
1435
1436 filp->private_data = dir;
1437
1438 return 0;
1439 }
1440
1441 static int subsystem_release(struct inode *inode, struct file *file)
1442 {
1443 struct trace_subsystem_dir *dir = file->private_data;
1444
1445 trace_array_put(dir->tr);
1446
1447 /*
1448 * If dir->subsystem is NULL, then this is a temporary
1449 * descriptor that was made for a trace_array to enable
1450 * all subsystems.
1451 */
1452 if (dir->subsystem)
1453 put_system(dir);
1454 else
1455 kfree(dir);
1456
1457 return 0;
1458 }
1459
1460 static ssize_t
1461 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1462 loff_t *ppos)
1463 {
1464 struct trace_subsystem_dir *dir = filp->private_data;
1465 struct event_subsystem *system = dir->subsystem;
1466 struct trace_seq *s;
1467 int r;
1468
1469 if (*ppos)
1470 return 0;
1471
1472 s = kmalloc(sizeof(*s), GFP_KERNEL);
1473 if (!s)
1474 return -ENOMEM;
1475
1476 trace_seq_init(s);
1477
1478 print_subsystem_event_filter(system, s);
1479 r = simple_read_from_buffer(ubuf, cnt, ppos,
1480 s->buffer, trace_seq_used(s));
1481
1482 kfree(s);
1483
1484 return r;
1485 }
1486
1487 static ssize_t
1488 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1489 loff_t *ppos)
1490 {
1491 struct trace_subsystem_dir *dir = filp->private_data;
1492 char *buf;
1493 int err;
1494
1495 if (cnt >= PAGE_SIZE)
1496 return -EINVAL;
1497
1498 buf = memdup_user_nul(ubuf, cnt);
1499 if (IS_ERR(buf))
1500 return PTR_ERR(buf);
1501
1502 err = apply_subsystem_event_filter(dir, buf);
1503 kfree(buf);
1504 if (err < 0)
1505 return err;
1506
1507 *ppos += cnt;
1508
1509 return cnt;
1510 }
1511
1512 static ssize_t
1513 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1514 {
1515 int (*func)(struct trace_seq *s) = filp->private_data;
1516 struct trace_seq *s;
1517 int r;
1518
1519 if (*ppos)
1520 return 0;
1521
1522 s = kmalloc(sizeof(*s), GFP_KERNEL);
1523 if (!s)
1524 return -ENOMEM;
1525
1526 trace_seq_init(s);
1527
1528 func(s);
1529 r = simple_read_from_buffer(ubuf, cnt, ppos,
1530 s->buffer, trace_seq_used(s));
1531
1532 kfree(s);
1533
1534 return r;
1535 }
1536
1537 static void ignore_task_cpu(void *data)
1538 {
1539 struct trace_array *tr = data;
1540 struct trace_pid_list *pid_list;
1541
1542 /*
1543 * This function is called by on_each_cpu() while the
1544 * event_mutex is held.
1545 */
1546 pid_list = rcu_dereference_protected(tr->filtered_pids,
1547 mutex_is_locked(&event_mutex));
1548
1549 this_cpu_write(tr->trace_buffer.data->ignore_pid,
1550 trace_ignore_this_task(pid_list, current));
1551 }
1552
1553 static ssize_t
1554 ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1555 size_t cnt, loff_t *ppos)
1556 {
1557 struct seq_file *m = filp->private_data;
1558 struct trace_array *tr = m->private;
1559 struct trace_pid_list *filtered_pids = NULL;
1560 struct trace_pid_list *pid_list;
1561 struct trace_event_file *file;
1562 ssize_t ret;
1563
1564 if (!cnt)
1565 return 0;
1566
1567 ret = tracing_update_buffers();
1568 if (ret < 0)
1569 return ret;
1570
1571 mutex_lock(&event_mutex);
1572
1573 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1574 lockdep_is_held(&event_mutex));
1575
1576 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
1577 if (ret < 0)
1578 goto out;
1579
1580 rcu_assign_pointer(tr->filtered_pids, pid_list);
1581
1582 list_for_each_entry(file, &tr->events, list) {
1583 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1584 }
1585
1586 if (filtered_pids) {
1587 synchronize_sched();
1588 trace_free_pid_list(filtered_pids);
1589 } else if (pid_list) {
1590 /*
1591 * Register a probe that is called before all other probes
1592 * to set ignore_pid if next or prev do not match.
1593 * Register a probe this is called after all other probes
1594 * to only keep ignore_pid set if next pid matches.
1595 */
1596 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1597 tr, INT_MAX);
1598 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1599 tr, 0);
1600
1601 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1602 tr, INT_MAX);
1603 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1604 tr, 0);
1605
1606 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1607 tr, INT_MAX);
1608 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1609 tr, 0);
1610
1611 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1612 tr, INT_MAX);
1613 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1614 tr, 0);
1615 }
1616
1617 /*
1618 * Ignoring of pids is done at task switch. But we have to
1619 * check for those tasks that are currently running.
1620 * Always do this in case a pid was appended or removed.
1621 */
1622 on_each_cpu(ignore_task_cpu, tr, 1);
1623
1624 out:
1625 mutex_unlock(&event_mutex);
1626
1627 if (ret > 0)
1628 *ppos += ret;
1629
1630 return ret;
1631 }
1632
1633 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1634 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1635 static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
1636 static int ftrace_event_release(struct inode *inode, struct file *file);
1637
1638 static const struct seq_operations show_event_seq_ops = {
1639 .start = t_start,
1640 .next = t_next,
1641 .show = t_show,
1642 .stop = t_stop,
1643 };
1644
1645 static const struct seq_operations show_set_event_seq_ops = {
1646 .start = s_start,
1647 .next = s_next,
1648 .show = t_show,
1649 .stop = t_stop,
1650 };
1651
1652 static const struct seq_operations show_set_pid_seq_ops = {
1653 .start = p_start,
1654 .next = p_next,
1655 .show = trace_pid_show,
1656 .stop = p_stop,
1657 };
1658
1659 static const struct file_operations ftrace_avail_fops = {
1660 .open = ftrace_event_avail_open,
1661 .read = seq_read,
1662 .llseek = seq_lseek,
1663 .release = seq_release,
1664 };
1665
1666 static const struct file_operations ftrace_set_event_fops = {
1667 .open = ftrace_event_set_open,
1668 .read = seq_read,
1669 .write = ftrace_event_write,
1670 .llseek = seq_lseek,
1671 .release = ftrace_event_release,
1672 };
1673
1674 static const struct file_operations ftrace_set_event_pid_fops = {
1675 .open = ftrace_event_set_pid_open,
1676 .read = seq_read,
1677 .write = ftrace_event_pid_write,
1678 .llseek = seq_lseek,
1679 .release = ftrace_event_release,
1680 };
1681
1682 static const struct file_operations ftrace_enable_fops = {
1683 .open = tracing_open_generic,
1684 .read = event_enable_read,
1685 .write = event_enable_write,
1686 .llseek = default_llseek,
1687 };
1688
1689 static const struct file_operations ftrace_event_format_fops = {
1690 .open = trace_format_open,
1691 .read = seq_read,
1692 .llseek = seq_lseek,
1693 .release = seq_release,
1694 };
1695
1696 static const struct file_operations ftrace_event_id_fops = {
1697 .read = event_id_read,
1698 .llseek = default_llseek,
1699 };
1700
1701 static const struct file_operations ftrace_event_filter_fops = {
1702 .open = tracing_open_generic,
1703 .read = event_filter_read,
1704 .write = event_filter_write,
1705 .llseek = default_llseek,
1706 };
1707
1708 static const struct file_operations ftrace_subsystem_filter_fops = {
1709 .open = subsystem_open,
1710 .read = subsystem_filter_read,
1711 .write = subsystem_filter_write,
1712 .llseek = default_llseek,
1713 .release = subsystem_release,
1714 };
1715
1716 static const struct file_operations ftrace_system_enable_fops = {
1717 .open = subsystem_open,
1718 .read = system_enable_read,
1719 .write = system_enable_write,
1720 .llseek = default_llseek,
1721 .release = subsystem_release,
1722 };
1723
1724 static const struct file_operations ftrace_tr_enable_fops = {
1725 .open = system_tr_open,
1726 .read = system_enable_read,
1727 .write = system_enable_write,
1728 .llseek = default_llseek,
1729 .release = subsystem_release,
1730 };
1731
1732 static const struct file_operations ftrace_show_header_fops = {
1733 .open = tracing_open_generic,
1734 .read = show_header,
1735 .llseek = default_llseek,
1736 };
1737
1738 static int
1739 ftrace_event_open(struct inode *inode, struct file *file,
1740 const struct seq_operations *seq_ops)
1741 {
1742 struct seq_file *m;
1743 int ret;
1744
1745 ret = seq_open(file, seq_ops);
1746 if (ret < 0)
1747 return ret;
1748 m = file->private_data;
1749 /* copy tr over to seq ops */
1750 m->private = inode->i_private;
1751
1752 return ret;
1753 }
1754
1755 static int ftrace_event_release(struct inode *inode, struct file *file)
1756 {
1757 struct trace_array *tr = inode->i_private;
1758
1759 trace_array_put(tr);
1760
1761 return seq_release(inode, file);
1762 }
1763
1764 static int
1765 ftrace_event_avail_open(struct inode *inode, struct file *file)
1766 {
1767 const struct seq_operations *seq_ops = &show_event_seq_ops;
1768
1769 return ftrace_event_open(inode, file, seq_ops);
1770 }
1771
1772 static int
1773 ftrace_event_set_open(struct inode *inode, struct file *file)
1774 {
1775 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1776 struct trace_array *tr = inode->i_private;
1777 int ret;
1778
1779 if (trace_array_get(tr) < 0)
1780 return -ENODEV;
1781
1782 if ((file->f_mode & FMODE_WRITE) &&
1783 (file->f_flags & O_TRUNC))
1784 ftrace_clear_events(tr);
1785
1786 ret = ftrace_event_open(inode, file, seq_ops);
1787 if (ret < 0)
1788 trace_array_put(tr);
1789 return ret;
1790 }
1791
1792 static int
1793 ftrace_event_set_pid_open(struct inode *inode, struct file *file)
1794 {
1795 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
1796 struct trace_array *tr = inode->i_private;
1797 int ret;
1798
1799 if (trace_array_get(tr) < 0)
1800 return -ENODEV;
1801
1802 if ((file->f_mode & FMODE_WRITE) &&
1803 (file->f_flags & O_TRUNC))
1804 ftrace_clear_event_pids(tr);
1805
1806 ret = ftrace_event_open(inode, file, seq_ops);
1807 if (ret < 0)
1808 trace_array_put(tr);
1809 return ret;
1810 }
1811
1812 static struct event_subsystem *
1813 create_new_subsystem(const char *name)
1814 {
1815 struct event_subsystem *system;
1816
1817 /* need to create new entry */
1818 system = kmalloc(sizeof(*system), GFP_KERNEL);
1819 if (!system)
1820 return NULL;
1821
1822 system->ref_count = 1;
1823
1824 /* Only allocate if dynamic (kprobes and modules) */
1825 system->name = kstrdup_const(name, GFP_KERNEL);
1826 if (!system->name)
1827 goto out_free;
1828
1829 system->filter = NULL;
1830
1831 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1832 if (!system->filter)
1833 goto out_free;
1834
1835 list_add(&system->list, &event_subsystems);
1836
1837 return system;
1838
1839 out_free:
1840 kfree_const(system->name);
1841 kfree(system);
1842 return NULL;
1843 }
1844
1845 static struct dentry *
1846 event_subsystem_dir(struct trace_array *tr, const char *name,
1847 struct trace_event_file *file, struct dentry *parent)
1848 {
1849 struct trace_subsystem_dir *dir;
1850 struct event_subsystem *system;
1851 struct dentry *entry;
1852
1853 /* First see if we did not already create this dir */
1854 list_for_each_entry(dir, &tr->systems, list) {
1855 system = dir->subsystem;
1856 if (strcmp(system->name, name) == 0) {
1857 dir->nr_events++;
1858 file->system = dir;
1859 return dir->entry;
1860 }
1861 }
1862
1863 /* Now see if the system itself exists. */
1864 list_for_each_entry(system, &event_subsystems, list) {
1865 if (strcmp(system->name, name) == 0)
1866 break;
1867 }
1868 /* Reset system variable when not found */
1869 if (&system->list == &event_subsystems)
1870 system = NULL;
1871
1872 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1873 if (!dir)
1874 goto out_fail;
1875
1876 if (!system) {
1877 system = create_new_subsystem(name);
1878 if (!system)
1879 goto out_free;
1880 } else
1881 __get_system(system);
1882
1883 dir->entry = tracefs_create_dir(name, parent);
1884 if (!dir->entry) {
1885 pr_warn("Failed to create system directory %s\n", name);
1886 __put_system(system);
1887 goto out_free;
1888 }
1889
1890 dir->tr = tr;
1891 dir->ref_count = 1;
1892 dir->nr_events = 1;
1893 dir->subsystem = system;
1894 file->system = dir;
1895
1896 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
1897 &ftrace_subsystem_filter_fops);
1898 if (!entry) {
1899 kfree(system->filter);
1900 system->filter = NULL;
1901 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
1902 }
1903
1904 trace_create_file("enable", 0644, dir->entry, dir,
1905 &ftrace_system_enable_fops);
1906
1907 list_add(&dir->list, &tr->systems);
1908
1909 return dir->entry;
1910
1911 out_free:
1912 kfree(dir);
1913 out_fail:
1914 /* Only print this message if failed on memory allocation */
1915 if (!dir || !system)
1916 pr_warn("No memory to create event subsystem %s\n", name);
1917 return NULL;
1918 }
1919
1920 static int
1921 event_create_dir(struct dentry *parent, struct trace_event_file *file)
1922 {
1923 struct trace_event_call *call = file->event_call;
1924 struct trace_array *tr = file->tr;
1925 struct list_head *head;
1926 struct dentry *d_events;
1927 const char *name;
1928 int ret;
1929
1930 /*
1931 * If the trace point header did not define TRACE_SYSTEM
1932 * then the system would be called "TRACE_SYSTEM".
1933 */
1934 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1935 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1936 if (!d_events)
1937 return -ENOMEM;
1938 } else
1939 d_events = parent;
1940
1941 name = trace_event_name(call);
1942 file->dir = tracefs_create_dir(name, d_events);
1943 if (!file->dir) {
1944 pr_warn("Could not create tracefs '%s' directory\n", name);
1945 return -1;
1946 }
1947
1948 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1949 trace_create_file("enable", 0644, file->dir, file,
1950 &ftrace_enable_fops);
1951
1952 #ifdef CONFIG_PERF_EVENTS
1953 if (call->event.type && call->class->reg)
1954 trace_create_file("id", 0444, file->dir,
1955 (void *)(long)call->event.type,
1956 &ftrace_event_id_fops);
1957 #endif
1958
1959 /*
1960 * Other events may have the same class. Only update
1961 * the fields if they are not already defined.
1962 */
1963 head = trace_get_fields(call);
1964 if (list_empty(head)) {
1965 ret = call->class->define_fields(call);
1966 if (ret < 0) {
1967 pr_warn("Could not initialize trace point events/%s\n",
1968 name);
1969 return -1;
1970 }
1971 }
1972 trace_create_file("filter", 0644, file->dir, file,
1973 &ftrace_event_filter_fops);
1974
1975 /*
1976 * Only event directories that can be enabled should have
1977 * triggers.
1978 */
1979 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1980 trace_create_file("trigger", 0644, file->dir, file,
1981 &event_trigger_fops);
1982
1983 #ifdef CONFIG_HIST_TRIGGERS
1984 trace_create_file("hist", 0444, file->dir, file,
1985 &event_hist_fops);
1986 #endif
1987 trace_create_file("format", 0444, file->dir, call,
1988 &ftrace_event_format_fops);
1989
1990 return 0;
1991 }
1992
1993 static void remove_event_from_tracers(struct trace_event_call *call)
1994 {
1995 struct trace_event_file *file;
1996 struct trace_array *tr;
1997
1998 do_for_each_event_file_safe(tr, file) {
1999 if (file->event_call != call)
2000 continue;
2001
2002 remove_event_file_dir(file);
2003 /*
2004 * The do_for_each_event_file_safe() is
2005 * a double loop. After finding the call for this
2006 * trace_array, we use break to jump to the next
2007 * trace_array.
2008 */
2009 break;
2010 } while_for_each_event_file();
2011 }
2012
2013 static void event_remove(struct trace_event_call *call)
2014 {
2015 struct trace_array *tr;
2016 struct trace_event_file *file;
2017
2018 do_for_each_event_file(tr, file) {
2019 if (file->event_call != call)
2020 continue;
2021 ftrace_event_enable_disable(file, 0);
2022 /*
2023 * The do_for_each_event_file() is
2024 * a double loop. After finding the call for this
2025 * trace_array, we use break to jump to the next
2026 * trace_array.
2027 */
2028 break;
2029 } while_for_each_event_file();
2030
2031 if (call->event.funcs)
2032 __unregister_trace_event(&call->event);
2033 remove_event_from_tracers(call);
2034 list_del(&call->list);
2035 }
2036
2037 static int event_init(struct trace_event_call *call)
2038 {
2039 int ret = 0;
2040 const char *name;
2041
2042 name = trace_event_name(call);
2043 if (WARN_ON(!name))
2044 return -EINVAL;
2045
2046 if (call->class->raw_init) {
2047 ret = call->class->raw_init(call);
2048 if (ret < 0 && ret != -ENOSYS)
2049 pr_warn("Could not initialize trace events/%s\n", name);
2050 }
2051
2052 return ret;
2053 }
2054
2055 static int
2056 __register_event(struct trace_event_call *call, struct module *mod)
2057 {
2058 int ret;
2059
2060 ret = event_init(call);
2061 if (ret < 0)
2062 return ret;
2063
2064 list_add(&call->list, &ftrace_events);
2065 call->mod = mod;
2066
2067 return 0;
2068 }
2069
2070 static char *enum_replace(char *ptr, struct trace_enum_map *map, int len)
2071 {
2072 int rlen;
2073 int elen;
2074
2075 /* Find the length of the enum value as a string */
2076 elen = snprintf(ptr, 0, "%ld", map->enum_value);
2077 /* Make sure there's enough room to replace the string with the value */
2078 if (len < elen)
2079 return NULL;
2080
2081 snprintf(ptr, elen + 1, "%ld", map->enum_value);
2082
2083 /* Get the rest of the string of ptr */
2084 rlen = strlen(ptr + len);
2085 memmove(ptr + elen, ptr + len, rlen);
2086 /* Make sure we end the new string */
2087 ptr[elen + rlen] = 0;
2088
2089 return ptr + elen;
2090 }
2091
2092 static void update_event_printk(struct trace_event_call *call,
2093 struct trace_enum_map *map)
2094 {
2095 char *ptr;
2096 int quote = 0;
2097 int len = strlen(map->enum_string);
2098
2099 for (ptr = call->print_fmt; *ptr; ptr++) {
2100 if (*ptr == '\\') {
2101 ptr++;
2102 /* paranoid */
2103 if (!*ptr)
2104 break;
2105 continue;
2106 }
2107 if (*ptr == '"') {
2108 quote ^= 1;
2109 continue;
2110 }
2111 if (quote)
2112 continue;
2113 if (isdigit(*ptr)) {
2114 /* skip numbers */
2115 do {
2116 ptr++;
2117 /* Check for alpha chars like ULL */
2118 } while (isalnum(*ptr));
2119 if (!*ptr)
2120 break;
2121 /*
2122 * A number must have some kind of delimiter after
2123 * it, and we can ignore that too.
2124 */
2125 continue;
2126 }
2127 if (isalpha(*ptr) || *ptr == '_') {
2128 if (strncmp(map->enum_string, ptr, len) == 0 &&
2129 !isalnum(ptr[len]) && ptr[len] != '_') {
2130 ptr = enum_replace(ptr, map, len);
2131 /* Hmm, enum string smaller than value */
2132 if (WARN_ON_ONCE(!ptr))
2133 return;
2134 /*
2135 * No need to decrement here, as enum_replace()
2136 * returns the pointer to the character passed
2137 * the enum, and two enums can not be placed
2138 * back to back without something in between.
2139 * We can skip that something in between.
2140 */
2141 continue;
2142 }
2143 skip_more:
2144 do {
2145 ptr++;
2146 } while (isalnum(*ptr) || *ptr == '_');
2147 if (!*ptr)
2148 break;
2149 /*
2150 * If what comes after this variable is a '.' or
2151 * '->' then we can continue to ignore that string.
2152 */
2153 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2154 ptr += *ptr == '.' ? 1 : 2;
2155 if (!*ptr)
2156 break;
2157 goto skip_more;
2158 }
2159 /*
2160 * Once again, we can skip the delimiter that came
2161 * after the string.
2162 */
2163 continue;
2164 }
2165 }
2166 }
2167
2168 void trace_event_enum_update(struct trace_enum_map **map, int len)
2169 {
2170 struct trace_event_call *call, *p;
2171 const char *last_system = NULL;
2172 int last_i;
2173 int i;
2174
2175 down_write(&trace_event_sem);
2176 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2177 /* events are usually grouped together with systems */
2178 if (!last_system || call->class->system != last_system) {
2179 last_i = 0;
2180 last_system = call->class->system;
2181 }
2182
2183 for (i = last_i; i < len; i++) {
2184 if (call->class->system == map[i]->system) {
2185 /* Save the first system if need be */
2186 if (!last_i)
2187 last_i = i;
2188 update_event_printk(call, map[i]);
2189 }
2190 }
2191 }
2192 up_write(&trace_event_sem);
2193 }
2194
2195 static struct trace_event_file *
2196 trace_create_new_event(struct trace_event_call *call,
2197 struct trace_array *tr)
2198 {
2199 struct trace_event_file *file;
2200
2201 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2202 if (!file)
2203 return NULL;
2204
2205 file->event_call = call;
2206 file->tr = tr;
2207 atomic_set(&file->sm_ref, 0);
2208 atomic_set(&file->tm_ref, 0);
2209 INIT_LIST_HEAD(&file->triggers);
2210 list_add(&file->list, &tr->events);
2211
2212 return file;
2213 }
2214
2215 /* Add an event to a trace directory */
2216 static int
2217 __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2218 {
2219 struct trace_event_file *file;
2220
2221 file = trace_create_new_event(call, tr);
2222 if (!file)
2223 return -ENOMEM;
2224
2225 return event_create_dir(tr->event_dir, file);
2226 }
2227
2228 /*
2229 * Just create a decriptor for early init. A descriptor is required
2230 * for enabling events at boot. We want to enable events before
2231 * the filesystem is initialized.
2232 */
2233 static __init int
2234 __trace_early_add_new_event(struct trace_event_call *call,
2235 struct trace_array *tr)
2236 {
2237 struct trace_event_file *file;
2238
2239 file = trace_create_new_event(call, tr);
2240 if (!file)
2241 return -ENOMEM;
2242
2243 return 0;
2244 }
2245
2246 struct ftrace_module_file_ops;
2247 static void __add_event_to_tracers(struct trace_event_call *call);
2248
2249 /* Add an additional event_call dynamically */
2250 int trace_add_event_call(struct trace_event_call *call)
2251 {
2252 int ret;
2253 mutex_lock(&trace_types_lock);
2254 mutex_lock(&event_mutex);
2255
2256 ret = __register_event(call, NULL);
2257 if (ret >= 0)
2258 __add_event_to_tracers(call);
2259
2260 mutex_unlock(&event_mutex);
2261 mutex_unlock(&trace_types_lock);
2262 return ret;
2263 }
2264
2265 /*
2266 * Must be called under locking of trace_types_lock, event_mutex and
2267 * trace_event_sem.
2268 */
2269 static void __trace_remove_event_call(struct trace_event_call *call)
2270 {
2271 event_remove(call);
2272 trace_destroy_fields(call);
2273 free_event_filter(call->filter);
2274 call->filter = NULL;
2275 }
2276
2277 static int probe_remove_event_call(struct trace_event_call *call)
2278 {
2279 struct trace_array *tr;
2280 struct trace_event_file *file;
2281
2282 #ifdef CONFIG_PERF_EVENTS
2283 if (call->perf_refcount)
2284 return -EBUSY;
2285 #endif
2286 do_for_each_event_file(tr, file) {
2287 if (file->event_call != call)
2288 continue;
2289 /*
2290 * We can't rely on ftrace_event_enable_disable(enable => 0)
2291 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2292 * TRACE_REG_UNREGISTER.
2293 */
2294 if (file->flags & EVENT_FILE_FL_ENABLED)
2295 return -EBUSY;
2296 /*
2297 * The do_for_each_event_file_safe() is
2298 * a double loop. After finding the call for this
2299 * trace_array, we use break to jump to the next
2300 * trace_array.
2301 */
2302 break;
2303 } while_for_each_event_file();
2304
2305 __trace_remove_event_call(call);
2306
2307 return 0;
2308 }
2309
2310 /* Remove an event_call */
2311 int trace_remove_event_call(struct trace_event_call *call)
2312 {
2313 int ret;
2314
2315 mutex_lock(&trace_types_lock);
2316 mutex_lock(&event_mutex);
2317 down_write(&trace_event_sem);
2318 ret = probe_remove_event_call(call);
2319 up_write(&trace_event_sem);
2320 mutex_unlock(&event_mutex);
2321 mutex_unlock(&trace_types_lock);
2322
2323 return ret;
2324 }
2325
2326 #define for_each_event(event, start, end) \
2327 for (event = start; \
2328 (unsigned long)event < (unsigned long)end; \
2329 event++)
2330
2331 #ifdef CONFIG_MODULES
2332
2333 static void trace_module_add_events(struct module *mod)
2334 {
2335 struct trace_event_call **call, **start, **end;
2336
2337 if (!mod->num_trace_events)
2338 return;
2339
2340 /* Don't add infrastructure for mods without tracepoints */
2341 if (trace_module_has_bad_taint(mod)) {
2342 pr_err("%s: module has bad taint, not creating trace events\n",
2343 mod->name);
2344 return;
2345 }
2346
2347 start = mod->trace_events;
2348 end = mod->trace_events + mod->num_trace_events;
2349
2350 for_each_event(call, start, end) {
2351 __register_event(*call, mod);
2352 __add_event_to_tracers(*call);
2353 }
2354 }
2355
2356 static void trace_module_remove_events(struct module *mod)
2357 {
2358 struct trace_event_call *call, *p;
2359 bool clear_trace = false;
2360
2361 down_write(&trace_event_sem);
2362 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2363 if (call->mod == mod) {
2364 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
2365 clear_trace = true;
2366 __trace_remove_event_call(call);
2367 }
2368 }
2369 up_write(&trace_event_sem);
2370
2371 /*
2372 * It is safest to reset the ring buffer if the module being unloaded
2373 * registered any events that were used. The only worry is if
2374 * a new module gets loaded, and takes on the same id as the events
2375 * of this module. When printing out the buffer, traced events left
2376 * over from this module may be passed to the new module events and
2377 * unexpected results may occur.
2378 */
2379 if (clear_trace)
2380 tracing_reset_all_online_cpus();
2381 }
2382
2383 static int trace_module_notify(struct notifier_block *self,
2384 unsigned long val, void *data)
2385 {
2386 struct module *mod = data;
2387
2388 mutex_lock(&trace_types_lock);
2389 mutex_lock(&event_mutex);
2390 switch (val) {
2391 case MODULE_STATE_COMING:
2392 trace_module_add_events(mod);
2393 break;
2394 case MODULE_STATE_GOING:
2395 trace_module_remove_events(mod);
2396 break;
2397 }
2398 mutex_unlock(&event_mutex);
2399 mutex_unlock(&trace_types_lock);
2400
2401 return 0;
2402 }
2403
2404 static struct notifier_block trace_module_nb = {
2405 .notifier_call = trace_module_notify,
2406 .priority = 1, /* higher than trace.c module notify */
2407 };
2408 #endif /* CONFIG_MODULES */
2409
2410 /* Create a new event directory structure for a trace directory. */
2411 static void
2412 __trace_add_event_dirs(struct trace_array *tr)
2413 {
2414 struct trace_event_call *call;
2415 int ret;
2416
2417 list_for_each_entry(call, &ftrace_events, list) {
2418 ret = __trace_add_new_event(call, tr);
2419 if (ret < 0)
2420 pr_warn("Could not create directory for event %s\n",
2421 trace_event_name(call));
2422 }
2423 }
2424
2425 struct trace_event_file *
2426 find_event_file(struct trace_array *tr, const char *system, const char *event)
2427 {
2428 struct trace_event_file *file;
2429 struct trace_event_call *call;
2430 const char *name;
2431
2432 list_for_each_entry(file, &tr->events, list) {
2433
2434 call = file->event_call;
2435 name = trace_event_name(call);
2436
2437 if (!name || !call->class || !call->class->reg)
2438 continue;
2439
2440 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2441 continue;
2442
2443 if (strcmp(event, name) == 0 &&
2444 strcmp(system, call->class->system) == 0)
2445 return file;
2446 }
2447 return NULL;
2448 }
2449
2450 #ifdef CONFIG_DYNAMIC_FTRACE
2451
2452 /* Avoid typos */
2453 #define ENABLE_EVENT_STR "enable_event"
2454 #define DISABLE_EVENT_STR "disable_event"
2455
2456 struct event_probe_data {
2457 struct trace_event_file *file;
2458 unsigned long count;
2459 int ref;
2460 bool enable;
2461 };
2462
2463 static void update_event_probe(struct event_probe_data *data)
2464 {
2465 if (data->enable)
2466 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2467 else
2468 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2469 }
2470
2471 static void
2472 event_enable_probe(unsigned long ip, unsigned long parent_ip,
2473 struct ftrace_probe_ops *ops, void **_data)
2474 {
2475 struct ftrace_func_mapper *mapper = ops->private_data;
2476 struct event_probe_data *data;
2477 void **pdata;
2478
2479 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2480 if (!pdata || !*pdata)
2481 return;
2482
2483 data = *pdata;
2484 update_event_probe(data);
2485 }
2486
2487 static void
2488 event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
2489 struct ftrace_probe_ops *ops, void **_data)
2490 {
2491 struct ftrace_func_mapper *mapper = ops->private_data;
2492 struct event_probe_data *data;
2493 void **pdata;
2494
2495 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2496 if (!pdata || !*pdata)
2497 return;
2498
2499 data = *pdata;
2500
2501 if (!data->count)
2502 return;
2503
2504 /* Skip if the event is in a state we want to switch to */
2505 if (data->enable == !(data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
2506 return;
2507
2508 if (data->count != -1)
2509 (data->count)--;
2510
2511 update_event_probe(data);
2512 }
2513
2514 static int
2515 event_enable_print(struct seq_file *m, unsigned long ip,
2516 struct ftrace_probe_ops *ops, void *_data)
2517 {
2518 struct ftrace_func_mapper *mapper = ops->private_data;
2519 struct event_probe_data *data;
2520 void **pdata;
2521
2522 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2523
2524 if (WARN_ON_ONCE(!pdata || !*pdata))
2525 return 0;
2526
2527 data = *pdata;
2528
2529 seq_printf(m, "%ps:", (void *)ip);
2530
2531 seq_printf(m, "%s:%s:%s",
2532 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2533 data->file->event_call->class->system,
2534 trace_event_name(data->file->event_call));
2535
2536 if (data->count == -1)
2537 seq_puts(m, ":unlimited\n");
2538 else
2539 seq_printf(m, ":count=%ld\n", data->count);
2540
2541 return 0;
2542 }
2543
2544 static int
2545 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
2546 void **_data)
2547 {
2548 struct ftrace_func_mapper *mapper = ops->private_data;
2549 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2550 struct event_probe_data *data = *pdata;
2551 int ret;
2552
2553 ret = ftrace_func_mapper_add_ip(mapper, ip, data);
2554 if (ret < 0)
2555 return ret;
2556
2557 data->ref++;
2558
2559 return 0;
2560 }
2561
2562 static void
2563 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
2564 void **_data)
2565 {
2566 struct ftrace_func_mapper *mapper = ops->private_data;
2567 struct event_probe_data *data;
2568
2569 data = ftrace_func_mapper_remove_ip(mapper, ip);
2570
2571 if (WARN_ON_ONCE(!data))
2572 return;
2573
2574 if (WARN_ON_ONCE(data->ref <= 0))
2575 return;
2576
2577 data->ref--;
2578 if (!data->ref) {
2579 /* Remove the SOFT_MODE flag */
2580 __ftrace_event_enable_disable(data->file, 0, 1);
2581 module_put(data->file->event_call->mod);
2582 kfree(data);
2583 }
2584 }
2585
2586 static struct ftrace_probe_ops event_enable_probe_ops = {
2587 .func = event_enable_probe,
2588 .print = event_enable_print,
2589 .init = event_enable_init,
2590 .free = event_enable_free,
2591 };
2592
2593 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2594 .func = event_enable_count_probe,
2595 .print = event_enable_print,
2596 .init = event_enable_init,
2597 .free = event_enable_free,
2598 };
2599
2600 static struct ftrace_probe_ops event_disable_probe_ops = {
2601 .func = event_enable_probe,
2602 .print = event_enable_print,
2603 .init = event_enable_init,
2604 .free = event_enable_free,
2605 };
2606
2607 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2608 .func = event_enable_count_probe,
2609 .print = event_enable_print,
2610 .init = event_enable_init,
2611 .free = event_enable_free,
2612 };
2613
2614 static int
2615 event_enable_func(struct ftrace_hash *hash,
2616 char *glob, char *cmd, char *param, int enabled)
2617 {
2618 struct trace_array *tr = top_trace_array();
2619 struct trace_event_file *file;
2620 struct ftrace_probe_ops *ops;
2621 struct event_probe_data *data;
2622 const char *system;
2623 const char *event;
2624 char *number;
2625 bool enable;
2626 int ret;
2627
2628 if (!tr)
2629 return -ENODEV;
2630
2631 /* hash funcs only work with set_ftrace_filter */
2632 if (!enabled || !param)
2633 return -EINVAL;
2634
2635 system = strsep(&param, ":");
2636 if (!param)
2637 return -EINVAL;
2638
2639 event = strsep(&param, ":");
2640
2641 mutex_lock(&event_mutex);
2642
2643 ret = -EINVAL;
2644 file = find_event_file(tr, system, event);
2645 if (!file)
2646 goto out;
2647
2648 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2649
2650 if (enable)
2651 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2652 else
2653 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2654
2655 if (glob[0] == '!') {
2656 unregister_ftrace_function_probe_func(glob+1, ops);
2657 ret = 0;
2658 goto out;
2659 }
2660
2661 ret = -ENOMEM;
2662
2663 if (!ops->private_data) {
2664 ops->private_data = allocate_ftrace_func_mapper();
2665 if (!ops->private_data)
2666 goto out;
2667 }
2668
2669 data = kzalloc(sizeof(*data), GFP_KERNEL);
2670 if (!data)
2671 goto out;
2672
2673 data->enable = enable;
2674 data->count = -1;
2675 data->file = file;
2676
2677 if (!param)
2678 goto out_reg;
2679
2680 number = strsep(&param, ":");
2681
2682 ret = -EINVAL;
2683 if (!strlen(number))
2684 goto out_free;
2685
2686 /*
2687 * We use the callback data field (which is a pointer)
2688 * as our counter.
2689 */
2690 ret = kstrtoul(number, 0, &data->count);
2691 if (ret)
2692 goto out_free;
2693
2694 out_reg:
2695 /* Don't let event modules unload while probe registered */
2696 ret = try_module_get(file->event_call->mod);
2697 if (!ret) {
2698 ret = -EBUSY;
2699 goto out_free;
2700 }
2701
2702 ret = __ftrace_event_enable_disable(file, 1, 1);
2703 if (ret < 0)
2704 goto out_put;
2705
2706 ret = register_ftrace_function_probe(glob, ops, data);
2707 /*
2708 * The above returns on success the # of functions enabled,
2709 * but if it didn't find any functions it returns zero.
2710 * Consider no functions a failure too.
2711 */
2712 if (!ret) {
2713 ret = -ENOENT;
2714 goto out_disable;
2715 } else if (ret < 0)
2716 goto out_disable;
2717 /* Just return zero, not the number of enabled functions */
2718 ret = 0;
2719 out:
2720 mutex_unlock(&event_mutex);
2721 return ret;
2722
2723 out_disable:
2724 __ftrace_event_enable_disable(file, 0, 1);
2725 out_put:
2726 module_put(file->event_call->mod);
2727 out_free:
2728 kfree(data);
2729 goto out;
2730 }
2731
2732 static struct ftrace_func_command event_enable_cmd = {
2733 .name = ENABLE_EVENT_STR,
2734 .func = event_enable_func,
2735 };
2736
2737 static struct ftrace_func_command event_disable_cmd = {
2738 .name = DISABLE_EVENT_STR,
2739 .func = event_enable_func,
2740 };
2741
2742 static __init int register_event_cmds(void)
2743 {
2744 int ret;
2745
2746 ret = register_ftrace_command(&event_enable_cmd);
2747 if (WARN_ON(ret < 0))
2748 return ret;
2749 ret = register_ftrace_command(&event_disable_cmd);
2750 if (WARN_ON(ret < 0))
2751 unregister_ftrace_command(&event_enable_cmd);
2752 return ret;
2753 }
2754 #else
2755 static inline int register_event_cmds(void) { return 0; }
2756 #endif /* CONFIG_DYNAMIC_FTRACE */
2757
2758 /*
2759 * The top level array has already had its trace_event_file
2760 * descriptors created in order to allow for early events to
2761 * be recorded. This function is called after the tracefs has been
2762 * initialized, and we now have to create the files associated
2763 * to the events.
2764 */
2765 static __init void
2766 __trace_early_add_event_dirs(struct trace_array *tr)
2767 {
2768 struct trace_event_file *file;
2769 int ret;
2770
2771
2772 list_for_each_entry(file, &tr->events, list) {
2773 ret = event_create_dir(tr->event_dir, file);
2774 if (ret < 0)
2775 pr_warn("Could not create directory for event %s\n",
2776 trace_event_name(file->event_call));
2777 }
2778 }
2779
2780 /*
2781 * For early boot up, the top trace array requires to have
2782 * a list of events that can be enabled. This must be done before
2783 * the filesystem is set up in order to allow events to be traced
2784 * early.
2785 */
2786 static __init void
2787 __trace_early_add_events(struct trace_array *tr)
2788 {
2789 struct trace_event_call *call;
2790 int ret;
2791
2792 list_for_each_entry(call, &ftrace_events, list) {
2793 /* Early boot up should not have any modules loaded */
2794 if (WARN_ON_ONCE(call->mod))
2795 continue;
2796
2797 ret = __trace_early_add_new_event(call, tr);
2798 if (ret < 0)
2799 pr_warn("Could not create early event %s\n",
2800 trace_event_name(call));
2801 }
2802 }
2803
2804 /* Remove the event directory structure for a trace directory. */
2805 static void
2806 __trace_remove_event_dirs(struct trace_array *tr)
2807 {
2808 struct trace_event_file *file, *next;
2809
2810 list_for_each_entry_safe(file, next, &tr->events, list)
2811 remove_event_file_dir(file);
2812 }
2813
2814 static void __add_event_to_tracers(struct trace_event_call *call)
2815 {
2816 struct trace_array *tr;
2817
2818 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2819 __trace_add_new_event(call, tr);
2820 }
2821
2822 extern struct trace_event_call *__start_ftrace_events[];
2823 extern struct trace_event_call *__stop_ftrace_events[];
2824
2825 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2826
2827 static __init int setup_trace_event(char *str)
2828 {
2829 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2830 ring_buffer_expanded = true;
2831 tracing_selftest_disabled = true;
2832
2833 return 1;
2834 }
2835 __setup("trace_event=", setup_trace_event);
2836
2837 /* Expects to have event_mutex held when called */
2838 static int
2839 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2840 {
2841 struct dentry *d_events;
2842 struct dentry *entry;
2843
2844 entry = tracefs_create_file("set_event", 0644, parent,
2845 tr, &ftrace_set_event_fops);
2846 if (!entry) {
2847 pr_warn("Could not create tracefs 'set_event' entry\n");
2848 return -ENOMEM;
2849 }
2850
2851 d_events = tracefs_create_dir("events", parent);
2852 if (!d_events) {
2853 pr_warn("Could not create tracefs 'events' directory\n");
2854 return -ENOMEM;
2855 }
2856
2857 entry = trace_create_file("enable", 0644, d_events,
2858 tr, &ftrace_tr_enable_fops);
2859 if (!entry) {
2860 pr_warn("Could not create tracefs 'enable' entry\n");
2861 return -ENOMEM;
2862 }
2863
2864 /* There are not as crucial, just warn if they are not created */
2865
2866 entry = tracefs_create_file("set_event_pid", 0644, parent,
2867 tr, &ftrace_set_event_pid_fops);
2868 if (!entry)
2869 pr_warn("Could not create tracefs 'set_event_pid' entry\n");
2870
2871 /* ring buffer internal formats */
2872 entry = trace_create_file("header_page", 0444, d_events,
2873 ring_buffer_print_page_header,
2874 &ftrace_show_header_fops);
2875 if (!entry)
2876 pr_warn("Could not create tracefs 'header_page' entry\n");
2877
2878 entry = trace_create_file("header_event", 0444, d_events,
2879 ring_buffer_print_entry_header,
2880 &ftrace_show_header_fops);
2881 if (!entry)
2882 pr_warn("Could not create tracefs 'header_event' entry\n");
2883
2884 tr->event_dir = d_events;
2885
2886 return 0;
2887 }
2888
2889 /**
2890 * event_trace_add_tracer - add a instance of a trace_array to events
2891 * @parent: The parent dentry to place the files/directories for events in
2892 * @tr: The trace array associated with these events
2893 *
2894 * When a new instance is created, it needs to set up its events
2895 * directory, as well as other files associated with events. It also
2896 * creates the event hierachry in the @parent/events directory.
2897 *
2898 * Returns 0 on success.
2899 */
2900 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2901 {
2902 int ret;
2903
2904 mutex_lock(&event_mutex);
2905
2906 ret = create_event_toplevel_files(parent, tr);
2907 if (ret)
2908 goto out_unlock;
2909
2910 down_write(&trace_event_sem);
2911 __trace_add_event_dirs(tr);
2912 up_write(&trace_event_sem);
2913
2914 out_unlock:
2915 mutex_unlock(&event_mutex);
2916
2917 return ret;
2918 }
2919
2920 /*
2921 * The top trace array already had its file descriptors created.
2922 * Now the files themselves need to be created.
2923 */
2924 static __init int
2925 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2926 {
2927 int ret;
2928
2929 mutex_lock(&event_mutex);
2930
2931 ret = create_event_toplevel_files(parent, tr);
2932 if (ret)
2933 goto out_unlock;
2934
2935 down_write(&trace_event_sem);
2936 __trace_early_add_event_dirs(tr);
2937 up_write(&trace_event_sem);
2938
2939 out_unlock:
2940 mutex_unlock(&event_mutex);
2941
2942 return ret;
2943 }
2944
2945 int event_trace_del_tracer(struct trace_array *tr)
2946 {
2947 mutex_lock(&event_mutex);
2948
2949 /* Disable any event triggers and associated soft-disabled events */
2950 clear_event_triggers(tr);
2951
2952 /* Clear the pid list */
2953 __ftrace_clear_event_pids(tr);
2954
2955 /* Disable any running events */
2956 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
2957
2958 /* Access to events are within rcu_read_lock_sched() */
2959 synchronize_sched();
2960
2961 down_write(&trace_event_sem);
2962 __trace_remove_event_dirs(tr);
2963 tracefs_remove_recursive(tr->event_dir);
2964 up_write(&trace_event_sem);
2965
2966 tr->event_dir = NULL;
2967
2968 mutex_unlock(&event_mutex);
2969
2970 return 0;
2971 }
2972
2973 static __init int event_trace_memsetup(void)
2974 {
2975 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
2976 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
2977 return 0;
2978 }
2979
2980 static __init void
2981 early_enable_events(struct trace_array *tr, bool disable_first)
2982 {
2983 char *buf = bootup_event_buf;
2984 char *token;
2985 int ret;
2986
2987 while (true) {
2988 token = strsep(&buf, ",");
2989
2990 if (!token)
2991 break;
2992
2993 if (*token) {
2994 /* Restarting syscalls requires that we stop them first */
2995 if (disable_first)
2996 ftrace_set_clr_event(tr, token, 0);
2997
2998 ret = ftrace_set_clr_event(tr, token, 1);
2999 if (ret)
3000 pr_warn("Failed to enable trace event: %s\n", token);
3001 }
3002
3003 /* Put back the comma to allow this to be called again */
3004 if (buf)
3005 *(buf - 1) = ',';
3006 }
3007 }
3008
3009 static __init int event_trace_enable(void)
3010 {
3011 struct trace_array *tr = top_trace_array();
3012 struct trace_event_call **iter, *call;
3013 int ret;
3014
3015 if (!tr)
3016 return -ENODEV;
3017
3018 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3019
3020 call = *iter;
3021 ret = event_init(call);
3022 if (!ret)
3023 list_add(&call->list, &ftrace_events);
3024 }
3025
3026 /*
3027 * We need the top trace array to have a working set of trace
3028 * points at early init, before the debug files and directories
3029 * are created. Create the file entries now, and attach them
3030 * to the actual file dentries later.
3031 */
3032 __trace_early_add_events(tr);
3033
3034 early_enable_events(tr, false);
3035
3036 trace_printk_start_comm();
3037
3038 register_event_cmds();
3039
3040 register_trigger_cmds();
3041
3042 return 0;
3043 }
3044
3045 /*
3046 * event_trace_enable() is called from trace_event_init() first to
3047 * initialize events and perhaps start any events that are on the
3048 * command line. Unfortunately, there are some events that will not
3049 * start this early, like the system call tracepoints that need
3050 * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
3051 * is called before pid 1 starts, and this flag is never set, making
3052 * the syscall tracepoint never get reached, but the event is enabled
3053 * regardless (and not doing anything).
3054 */
3055 static __init int event_trace_enable_again(void)
3056 {
3057 struct trace_array *tr;
3058
3059 tr = top_trace_array();
3060 if (!tr)
3061 return -ENODEV;
3062
3063 early_enable_events(tr, true);
3064
3065 return 0;
3066 }
3067
3068 early_initcall(event_trace_enable_again);
3069
3070 static __init int event_trace_init(void)
3071 {
3072 struct trace_array *tr;
3073 struct dentry *d_tracer;
3074 struct dentry *entry;
3075 int ret;
3076
3077 tr = top_trace_array();
3078 if (!tr)
3079 return -ENODEV;
3080
3081 d_tracer = tracing_init_dentry();
3082 if (IS_ERR(d_tracer))
3083 return 0;
3084
3085 entry = tracefs_create_file("available_events", 0444, d_tracer,
3086 tr, &ftrace_avail_fops);
3087 if (!entry)
3088 pr_warn("Could not create tracefs 'available_events' entry\n");
3089
3090 if (trace_define_generic_fields())
3091 pr_warn("tracing: Failed to allocated generic fields");
3092
3093 if (trace_define_common_fields())
3094 pr_warn("tracing: Failed to allocate common fields");
3095
3096 ret = early_event_add_tracer(d_tracer, tr);
3097 if (ret)
3098 return ret;
3099
3100 #ifdef CONFIG_MODULES
3101 ret = register_module_notifier(&trace_module_nb);
3102 if (ret)
3103 pr_warn("Failed to register trace events module notifier\n");
3104 #endif
3105 return 0;
3106 }
3107
3108 void __init trace_event_init(void)
3109 {
3110 event_trace_memsetup();
3111 init_ftrace_syscalls();
3112 event_trace_enable();
3113 }
3114
3115 fs_initcall(event_trace_init);
3116
3117 #ifdef CONFIG_FTRACE_STARTUP_TEST
3118
3119 static DEFINE_SPINLOCK(test_spinlock);
3120 static DEFINE_SPINLOCK(test_spinlock_irq);
3121 static DEFINE_MUTEX(test_mutex);
3122
3123 static __init void test_work(struct work_struct *dummy)
3124 {
3125 spin_lock(&test_spinlock);
3126 spin_lock_irq(&test_spinlock_irq);
3127 udelay(1);
3128 spin_unlock_irq(&test_spinlock_irq);
3129 spin_unlock(&test_spinlock);
3130
3131 mutex_lock(&test_mutex);
3132 msleep(1);
3133 mutex_unlock(&test_mutex);
3134 }
3135
3136 static __init int event_test_thread(void *unused)
3137 {
3138 void *test_malloc;
3139
3140 test_malloc = kmalloc(1234, GFP_KERNEL);
3141 if (!test_malloc)
3142 pr_info("failed to kmalloc\n");
3143
3144 schedule_on_each_cpu(test_work);
3145
3146 kfree(test_malloc);
3147
3148 set_current_state(TASK_INTERRUPTIBLE);
3149 while (!kthread_should_stop()) {
3150 schedule();
3151 set_current_state(TASK_INTERRUPTIBLE);
3152 }
3153 __set_current_state(TASK_RUNNING);
3154
3155 return 0;
3156 }
3157
3158 /*
3159 * Do various things that may trigger events.
3160 */
3161 static __init void event_test_stuff(void)
3162 {
3163 struct task_struct *test_thread;
3164
3165 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3166 msleep(1);
3167 kthread_stop(test_thread);
3168 }
3169
3170 /*
3171 * For every trace event defined, we will test each trace point separately,
3172 * and then by groups, and finally all trace points.
3173 */
3174 static __init void event_trace_self_tests(void)
3175 {
3176 struct trace_subsystem_dir *dir;
3177 struct trace_event_file *file;
3178 struct trace_event_call *call;
3179 struct event_subsystem *system;
3180 struct trace_array *tr;
3181 int ret;
3182
3183 tr = top_trace_array();
3184 if (!tr)
3185 return;
3186
3187 pr_info("Running tests on trace events:\n");
3188
3189 list_for_each_entry(file, &tr->events, list) {
3190
3191 call = file->event_call;
3192
3193 /* Only test those that have a probe */
3194 if (!call->class || !call->class->probe)
3195 continue;
3196
3197 /*
3198 * Testing syscall events here is pretty useless, but
3199 * we still do it if configured. But this is time consuming.
3200 * What we really need is a user thread to perform the
3201 * syscalls as we test.
3202 */
3203 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3204 if (call->class->system &&
3205 strcmp(call->class->system, "syscalls") == 0)
3206 continue;
3207 #endif
3208
3209 pr_info("Testing event %s: ", trace_event_name(call));
3210
3211 /*
3212 * If an event is already enabled, someone is using
3213 * it and the self test should not be on.
3214 */
3215 if (file->flags & EVENT_FILE_FL_ENABLED) {
3216 pr_warn("Enabled event during self test!\n");
3217 WARN_ON_ONCE(1);
3218 continue;
3219 }
3220
3221 ftrace_event_enable_disable(file, 1);
3222 event_test_stuff();
3223 ftrace_event_enable_disable(file, 0);
3224
3225 pr_cont("OK\n");
3226 }
3227
3228 /* Now test at the sub system level */
3229
3230 pr_info("Running tests on trace event systems:\n");
3231
3232 list_for_each_entry(dir, &tr->systems, list) {
3233
3234 system = dir->subsystem;
3235
3236 /* the ftrace system is special, skip it */
3237 if (strcmp(system->name, "ftrace") == 0)
3238 continue;
3239
3240 pr_info("Testing event system %s: ", system->name);
3241
3242 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3243 if (WARN_ON_ONCE(ret)) {
3244 pr_warn("error enabling system %s\n",
3245 system->name);
3246 continue;
3247 }
3248
3249 event_test_stuff();
3250
3251 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3252 if (WARN_ON_ONCE(ret)) {
3253 pr_warn("error disabling system %s\n",
3254 system->name);
3255 continue;
3256 }
3257
3258 pr_cont("OK\n");
3259 }
3260
3261 /* Test with all events enabled */
3262
3263 pr_info("Running tests on all trace events:\n");
3264 pr_info("Testing all events: ");
3265
3266 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3267 if (WARN_ON_ONCE(ret)) {
3268 pr_warn("error enabling all events\n");
3269 return;
3270 }
3271
3272 event_test_stuff();
3273
3274 /* reset sysname */
3275 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3276 if (WARN_ON_ONCE(ret)) {
3277 pr_warn("error disabling all events\n");
3278 return;
3279 }
3280
3281 pr_cont("OK\n");
3282 }
3283
3284 #ifdef CONFIG_FUNCTION_TRACER
3285
3286 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3287
3288 static struct trace_event_file event_trace_file __initdata;
3289
3290 static void __init
3291 function_test_events_call(unsigned long ip, unsigned long parent_ip,
3292 struct ftrace_ops *op, struct pt_regs *pt_regs)
3293 {
3294 struct ring_buffer_event *event;
3295 struct ring_buffer *buffer;
3296 struct ftrace_entry *entry;
3297 unsigned long flags;
3298 long disabled;
3299 int cpu;
3300 int pc;
3301
3302 pc = preempt_count();
3303 preempt_disable_notrace();
3304 cpu = raw_smp_processor_id();
3305 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3306
3307 if (disabled != 1)
3308 goto out;
3309
3310 local_save_flags(flags);
3311
3312 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
3313 TRACE_FN, sizeof(*entry),
3314 flags, pc);
3315 if (!event)
3316 goto out;
3317 entry = ring_buffer_event_data(event);
3318 entry->ip = ip;
3319 entry->parent_ip = parent_ip;
3320
3321 event_trigger_unlock_commit(&event_trace_file, buffer, event,
3322 entry, flags, pc);
3323 out:
3324 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3325 preempt_enable_notrace();
3326 }
3327
3328 static struct ftrace_ops trace_ops __initdata =
3329 {
3330 .func = function_test_events_call,
3331 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
3332 };
3333
3334 static __init void event_trace_self_test_with_function(void)
3335 {
3336 int ret;
3337
3338 event_trace_file.tr = top_trace_array();
3339 if (WARN_ON(!event_trace_file.tr))
3340 return;
3341
3342 ret = register_ftrace_function(&trace_ops);
3343 if (WARN_ON(ret < 0)) {
3344 pr_info("Failed to enable function tracer for event tests\n");
3345 return;
3346 }
3347 pr_info("Running tests again, along with the function tracer\n");
3348 event_trace_self_tests();
3349 unregister_ftrace_function(&trace_ops);
3350 }
3351 #else
3352 static __init void event_trace_self_test_with_function(void)
3353 {
3354 }
3355 #endif
3356
3357 static __init int event_trace_self_tests_init(void)
3358 {
3359 if (!tracing_selftest_disabled) {
3360 event_trace_self_tests();
3361 event_trace_self_test_with_function();
3362 }
3363
3364 return 0;
3365 }
3366
3367 late_initcall(event_trace_self_tests_init);
3368
3369 #endif
Linux with added FPC-III support