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Merge tag 'samsung-fixes-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/krzk...
[mirror_ubuntu-bionic-kernel.git] / kernel / trace / trace_events.c
1 /*
2 * event tracer
3 *
4 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
5 *
6 * - Added format output of fields of the trace point.
7 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
8 *
9 */
10
11 #define pr_fmt(fmt) fmt
12
13 #include <linux/workqueue.h>
14 #include <linux/spinlock.h>
15 #include <linux/kthread.h>
16 #include <linux/tracefs.h>
17 #include <linux/uaccess.h>
18 #include <linux/vmalloc.h>
19 #include <linux/module.h>
20 #include <linux/ctype.h>
21 #include <linux/sort.h>
22 #include <linux/slab.h>
23 #include <linux/delay.h>
24
25 #include <trace/events/sched.h>
26
27 #include <asm/setup.h>
28
29 #include "trace_output.h"
30
31 #undef TRACE_SYSTEM
32 #define TRACE_SYSTEM "TRACE_SYSTEM"
33
34 DEFINE_MUTEX(event_mutex);
35
36 LIST_HEAD(ftrace_events);
37 static LIST_HEAD(ftrace_generic_fields);
38 static LIST_HEAD(ftrace_common_fields);
39
40 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
41
42 static struct kmem_cache *field_cachep;
43 static struct kmem_cache *file_cachep;
44
45 static inline int system_refcount(struct event_subsystem *system)
46 {
47 return system->ref_count;
48 }
49
50 static int system_refcount_inc(struct event_subsystem *system)
51 {
52 return system->ref_count++;
53 }
54
55 static int system_refcount_dec(struct event_subsystem *system)
56 {
57 return --system->ref_count;
58 }
59
60 /* Double loops, do not use break, only goto's work */
61 #define do_for_each_event_file(tr, file) \
62 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
63 list_for_each_entry(file, &tr->events, list)
64
65 #define do_for_each_event_file_safe(tr, file) \
66 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
67 struct trace_event_file *___n; \
68 list_for_each_entry_safe(file, ___n, &tr->events, list)
69
70 #define while_for_each_event_file() \
71 }
72
73 static struct list_head *
74 trace_get_fields(struct trace_event_call *event_call)
75 {
76 if (!event_call->class->get_fields)
77 return &event_call->class->fields;
78 return event_call->class->get_fields(event_call);
79 }
80
81 static struct ftrace_event_field *
82 __find_event_field(struct list_head *head, char *name)
83 {
84 struct ftrace_event_field *field;
85
86 list_for_each_entry(field, head, link) {
87 if (!strcmp(field->name, name))
88 return field;
89 }
90
91 return NULL;
92 }
93
94 struct ftrace_event_field *
95 trace_find_event_field(struct trace_event_call *call, char *name)
96 {
97 struct ftrace_event_field *field;
98 struct list_head *head;
99
100 head = trace_get_fields(call);
101 field = __find_event_field(head, name);
102 if (field)
103 return field;
104
105 field = __find_event_field(&ftrace_generic_fields, name);
106 if (field)
107 return field;
108
109 return __find_event_field(&ftrace_common_fields, name);
110 }
111
112 static int __trace_define_field(struct list_head *head, const char *type,
113 const char *name, int offset, int size,
114 int is_signed, int filter_type)
115 {
116 struct ftrace_event_field *field;
117
118 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
119 if (!field)
120 return -ENOMEM;
121
122 field->name = name;
123 field->type = type;
124
125 if (filter_type == FILTER_OTHER)
126 field->filter_type = filter_assign_type(type);
127 else
128 field->filter_type = filter_type;
129
130 field->offset = offset;
131 field->size = size;
132 field->is_signed = is_signed;
133
134 list_add(&field->link, head);
135
136 return 0;
137 }
138
139 int trace_define_field(struct trace_event_call *call, const char *type,
140 const char *name, int offset, int size, int is_signed,
141 int filter_type)
142 {
143 struct list_head *head;
144
145 if (WARN_ON(!call->class))
146 return 0;
147
148 head = trace_get_fields(call);
149 return __trace_define_field(head, type, name, offset, size,
150 is_signed, filter_type);
151 }
152 EXPORT_SYMBOL_GPL(trace_define_field);
153
154 #define __generic_field(type, item, filter_type) \
155 ret = __trace_define_field(&ftrace_generic_fields, #type, \
156 #item, 0, 0, is_signed_type(type), \
157 filter_type); \
158 if (ret) \
159 return ret;
160
161 #define __common_field(type, item) \
162 ret = __trace_define_field(&ftrace_common_fields, #type, \
163 "common_" #item, \
164 offsetof(typeof(ent), item), \
165 sizeof(ent.item), \
166 is_signed_type(type), FILTER_OTHER); \
167 if (ret) \
168 return ret;
169
170 static int trace_define_generic_fields(void)
171 {
172 int ret;
173
174 __generic_field(int, CPU, FILTER_CPU);
175 __generic_field(int, cpu, FILTER_CPU);
176 __generic_field(char *, COMM, FILTER_COMM);
177 __generic_field(char *, comm, FILTER_COMM);
178
179 return ret;
180 }
181
182 static int trace_define_common_fields(void)
183 {
184 int ret;
185 struct trace_entry ent;
186
187 __common_field(unsigned short, type);
188 __common_field(unsigned char, flags);
189 __common_field(unsigned char, preempt_count);
190 __common_field(int, pid);
191
192 return ret;
193 }
194
195 static void trace_destroy_fields(struct trace_event_call *call)
196 {
197 struct ftrace_event_field *field, *next;
198 struct list_head *head;
199
200 head = trace_get_fields(call);
201 list_for_each_entry_safe(field, next, head, link) {
202 list_del(&field->link);
203 kmem_cache_free(field_cachep, field);
204 }
205 }
206
207 /*
208 * run-time version of trace_event_get_offsets_<call>() that returns the last
209 * accessible offset of trace fields excluding __dynamic_array bytes
210 */
211 int trace_event_get_offsets(struct trace_event_call *call)
212 {
213 struct ftrace_event_field *tail;
214 struct list_head *head;
215
216 head = trace_get_fields(call);
217 /*
218 * head->next points to the last field with the largest offset,
219 * since it was added last by trace_define_field()
220 */
221 tail = list_first_entry(head, struct ftrace_event_field, link);
222 return tail->offset + tail->size;
223 }
224
225 int trace_event_raw_init(struct trace_event_call *call)
226 {
227 int id;
228
229 id = register_trace_event(&call->event);
230 if (!id)
231 return -ENODEV;
232
233 return 0;
234 }
235 EXPORT_SYMBOL_GPL(trace_event_raw_init);
236
237 bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
238 {
239 struct trace_array *tr = trace_file->tr;
240 struct trace_array_cpu *data;
241 struct trace_pid_list *pid_list;
242
243 pid_list = rcu_dereference_sched(tr->filtered_pids);
244 if (!pid_list)
245 return false;
246
247 data = this_cpu_ptr(tr->trace_buffer.data);
248
249 return data->ignore_pid;
250 }
251 EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
252
253 void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
254 struct trace_event_file *trace_file,
255 unsigned long len)
256 {
257 struct trace_event_call *event_call = trace_file->event_call;
258
259 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
260 trace_event_ignore_this_pid(trace_file))
261 return NULL;
262
263 local_save_flags(fbuffer->flags);
264 fbuffer->pc = preempt_count();
265 fbuffer->trace_file = trace_file;
266
267 fbuffer->event =
268 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
269 event_call->event.type, len,
270 fbuffer->flags, fbuffer->pc);
271 if (!fbuffer->event)
272 return NULL;
273
274 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
275 return fbuffer->entry;
276 }
277 EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
278
279 static DEFINE_SPINLOCK(tracepoint_iter_lock);
280
281 static void output_printk(struct trace_event_buffer *fbuffer)
282 {
283 struct trace_event_call *event_call;
284 struct trace_event *event;
285 unsigned long flags;
286 struct trace_iterator *iter = tracepoint_print_iter;
287
288 if (!iter)
289 return;
290
291 event_call = fbuffer->trace_file->event_call;
292 if (!event_call || !event_call->event.funcs ||
293 !event_call->event.funcs->trace)
294 return;
295
296 event = &fbuffer->trace_file->event_call->event;
297
298 spin_lock_irqsave(&tracepoint_iter_lock, flags);
299 trace_seq_init(&iter->seq);
300 iter->ent = fbuffer->entry;
301 event_call->event.funcs->trace(iter, 0, event);
302 trace_seq_putc(&iter->seq, 0);
303 printk("%s", iter->seq.buffer);
304
305 spin_unlock_irqrestore(&tracepoint_iter_lock, flags);
306 }
307
308 void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)
309 {
310 if (tracepoint_printk)
311 output_printk(fbuffer);
312
313 event_trigger_unlock_commit(fbuffer->trace_file, fbuffer->buffer,
314 fbuffer->event, fbuffer->entry,
315 fbuffer->flags, fbuffer->pc);
316 }
317 EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
318
319 int trace_event_reg(struct trace_event_call *call,
320 enum trace_reg type, void *data)
321 {
322 struct trace_event_file *file = data;
323
324 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
325 switch (type) {
326 case TRACE_REG_REGISTER:
327 return tracepoint_probe_register(call->tp,
328 call->class->probe,
329 file);
330 case TRACE_REG_UNREGISTER:
331 tracepoint_probe_unregister(call->tp,
332 call->class->probe,
333 file);
334 return 0;
335
336 #ifdef CONFIG_PERF_EVENTS
337 case TRACE_REG_PERF_REGISTER:
338 return tracepoint_probe_register(call->tp,
339 call->class->perf_probe,
340 call);
341 case TRACE_REG_PERF_UNREGISTER:
342 tracepoint_probe_unregister(call->tp,
343 call->class->perf_probe,
344 call);
345 return 0;
346 case TRACE_REG_PERF_OPEN:
347 case TRACE_REG_PERF_CLOSE:
348 case TRACE_REG_PERF_ADD:
349 case TRACE_REG_PERF_DEL:
350 return 0;
351 #endif
352 }
353 return 0;
354 }
355 EXPORT_SYMBOL_GPL(trace_event_reg);
356
357 void trace_event_enable_cmd_record(bool enable)
358 {
359 struct trace_event_file *file;
360 struct trace_array *tr;
361
362 mutex_lock(&event_mutex);
363 do_for_each_event_file(tr, file) {
364
365 if (!(file->flags & EVENT_FILE_FL_ENABLED))
366 continue;
367
368 if (enable) {
369 tracing_start_cmdline_record();
370 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
371 } else {
372 tracing_stop_cmdline_record();
373 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
374 }
375 } while_for_each_event_file();
376 mutex_unlock(&event_mutex);
377 }
378
379 static int __ftrace_event_enable_disable(struct trace_event_file *file,
380 int enable, int soft_disable)
381 {
382 struct trace_event_call *call = file->event_call;
383 struct trace_array *tr = file->tr;
384 unsigned long file_flags = file->flags;
385 int ret = 0;
386 int disable;
387
388 switch (enable) {
389 case 0:
390 /*
391 * When soft_disable is set and enable is cleared, the sm_ref
392 * reference counter is decremented. If it reaches 0, we want
393 * to clear the SOFT_DISABLED flag but leave the event in the
394 * state that it was. That is, if the event was enabled and
395 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
396 * is set we do not want the event to be enabled before we
397 * clear the bit.
398 *
399 * When soft_disable is not set but the SOFT_MODE flag is,
400 * we do nothing. Do not disable the tracepoint, otherwise
401 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
402 */
403 if (soft_disable) {
404 if (atomic_dec_return(&file->sm_ref) > 0)
405 break;
406 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
407 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
408 } else
409 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
410
411 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
412 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
413 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
414 tracing_stop_cmdline_record();
415 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
416 }
417 call->class->reg(call, TRACE_REG_UNREGISTER, file);
418 }
419 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
420 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
421 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
422 else
423 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
424 break;
425 case 1:
426 /*
427 * When soft_disable is set and enable is set, we want to
428 * register the tracepoint for the event, but leave the event
429 * as is. That means, if the event was already enabled, we do
430 * nothing (but set SOFT_MODE). If the event is disabled, we
431 * set SOFT_DISABLED before enabling the event tracepoint, so
432 * it still seems to be disabled.
433 */
434 if (!soft_disable)
435 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
436 else {
437 if (atomic_inc_return(&file->sm_ref) > 1)
438 break;
439 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
440 }
441
442 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
443
444 /* Keep the event disabled, when going to SOFT_MODE. */
445 if (soft_disable)
446 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
447
448 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
449 tracing_start_cmdline_record();
450 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
451 }
452 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
453 if (ret) {
454 tracing_stop_cmdline_record();
455 pr_info("event trace: Could not enable event "
456 "%s\n", trace_event_name(call));
457 break;
458 }
459 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
460
461 /* WAS_ENABLED gets set but never cleared. */
462 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
463 }
464 break;
465 }
466
467 /* Enable or disable use of trace_buffered_event */
468 if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) !=
469 (file->flags & EVENT_FILE_FL_SOFT_DISABLED)) {
470 if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
471 trace_buffered_event_enable();
472 else
473 trace_buffered_event_disable();
474 }
475
476 return ret;
477 }
478
479 int trace_event_enable_disable(struct trace_event_file *file,
480 int enable, int soft_disable)
481 {
482 return __ftrace_event_enable_disable(file, enable, soft_disable);
483 }
484
485 static int ftrace_event_enable_disable(struct trace_event_file *file,
486 int enable)
487 {
488 return __ftrace_event_enable_disable(file, enable, 0);
489 }
490
491 static void ftrace_clear_events(struct trace_array *tr)
492 {
493 struct trace_event_file *file;
494
495 mutex_lock(&event_mutex);
496 list_for_each_entry(file, &tr->events, list) {
497 ftrace_event_enable_disable(file, 0);
498 }
499 mutex_unlock(&event_mutex);
500 }
501
502 /* Shouldn't this be in a header? */
503 extern int pid_max;
504
505 /* Returns true if found in filter */
506 static bool
507 find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid)
508 {
509 /*
510 * If pid_max changed after filtered_pids was created, we
511 * by default ignore all pids greater than the previous pid_max.
512 */
513 if (search_pid >= filtered_pids->pid_max)
514 return false;
515
516 return test_bit(search_pid, filtered_pids->pids);
517 }
518
519 static bool
520 ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task)
521 {
522 /*
523 * Return false, because if filtered_pids does not exist,
524 * all pids are good to trace.
525 */
526 if (!filtered_pids)
527 return false;
528
529 return !find_filtered_pid(filtered_pids, task->pid);
530 }
531
532 static void filter_add_remove_task(struct trace_pid_list *pid_list,
533 struct task_struct *self,
534 struct task_struct *task)
535 {
536 if (!pid_list)
537 return;
538
539 /* For forks, we only add if the forking task is listed */
540 if (self) {
541 if (!find_filtered_pid(pid_list, self->pid))
542 return;
543 }
544
545 /* Sorry, but we don't support pid_max changing after setting */
546 if (task->pid >= pid_list->pid_max)
547 return;
548
549 /* "self" is set for forks, and NULL for exits */
550 if (self)
551 set_bit(task->pid, pid_list->pids);
552 else
553 clear_bit(task->pid, pid_list->pids);
554 }
555
556 static void
557 event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
558 {
559 struct trace_pid_list *pid_list;
560 struct trace_array *tr = data;
561
562 pid_list = rcu_dereference_sched(tr->filtered_pids);
563 filter_add_remove_task(pid_list, NULL, task);
564 }
565
566 static void
567 event_filter_pid_sched_process_fork(void *data,
568 struct task_struct *self,
569 struct task_struct *task)
570 {
571 struct trace_pid_list *pid_list;
572 struct trace_array *tr = data;
573
574 pid_list = rcu_dereference_sched(tr->filtered_pids);
575 filter_add_remove_task(pid_list, self, task);
576 }
577
578 void trace_event_follow_fork(struct trace_array *tr, bool enable)
579 {
580 if (enable) {
581 register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
582 tr, INT_MIN);
583 register_trace_prio_sched_process_exit(event_filter_pid_sched_process_exit,
584 tr, INT_MAX);
585 } else {
586 unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
587 tr);
588 unregister_trace_sched_process_exit(event_filter_pid_sched_process_exit,
589 tr);
590 }
591 }
592
593 static void
594 event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
595 struct task_struct *prev, struct task_struct *next)
596 {
597 struct trace_array *tr = data;
598 struct trace_pid_list *pid_list;
599
600 pid_list = rcu_dereference_sched(tr->filtered_pids);
601
602 this_cpu_write(tr->trace_buffer.data->ignore_pid,
603 ignore_this_task(pid_list, prev) &&
604 ignore_this_task(pid_list, next));
605 }
606
607 static void
608 event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
609 struct task_struct *prev, struct task_struct *next)
610 {
611 struct trace_array *tr = data;
612 struct trace_pid_list *pid_list;
613
614 pid_list = rcu_dereference_sched(tr->filtered_pids);
615
616 this_cpu_write(tr->trace_buffer.data->ignore_pid,
617 ignore_this_task(pid_list, next));
618 }
619
620 static void
621 event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
622 {
623 struct trace_array *tr = data;
624 struct trace_pid_list *pid_list;
625
626 /* Nothing to do if we are already tracing */
627 if (!this_cpu_read(tr->trace_buffer.data->ignore_pid))
628 return;
629
630 pid_list = rcu_dereference_sched(tr->filtered_pids);
631
632 this_cpu_write(tr->trace_buffer.data->ignore_pid,
633 ignore_this_task(pid_list, task));
634 }
635
636 static void
637 event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
638 {
639 struct trace_array *tr = data;
640 struct trace_pid_list *pid_list;
641
642 /* Nothing to do if we are not tracing */
643 if (this_cpu_read(tr->trace_buffer.data->ignore_pid))
644 return;
645
646 pid_list = rcu_dereference_sched(tr->filtered_pids);
647
648 /* Set tracing if current is enabled */
649 this_cpu_write(tr->trace_buffer.data->ignore_pid,
650 ignore_this_task(pid_list, current));
651 }
652
653 static void __ftrace_clear_event_pids(struct trace_array *tr)
654 {
655 struct trace_pid_list *pid_list;
656 struct trace_event_file *file;
657 int cpu;
658
659 pid_list = rcu_dereference_protected(tr->filtered_pids,
660 lockdep_is_held(&event_mutex));
661 if (!pid_list)
662 return;
663
664 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
665 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
666
667 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
668 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
669
670 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
671 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
672
673 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
674 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
675
676 list_for_each_entry(file, &tr->events, list) {
677 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
678 }
679
680 for_each_possible_cpu(cpu)
681 per_cpu_ptr(tr->trace_buffer.data, cpu)->ignore_pid = false;
682
683 rcu_assign_pointer(tr->filtered_pids, NULL);
684
685 /* Wait till all users are no longer using pid filtering */
686 synchronize_sched();
687
688 vfree(pid_list->pids);
689 kfree(pid_list);
690 }
691
692 static void ftrace_clear_event_pids(struct trace_array *tr)
693 {
694 mutex_lock(&event_mutex);
695 __ftrace_clear_event_pids(tr);
696 mutex_unlock(&event_mutex);
697 }
698
699 static void __put_system(struct event_subsystem *system)
700 {
701 struct event_filter *filter = system->filter;
702
703 WARN_ON_ONCE(system_refcount(system) == 0);
704 if (system_refcount_dec(system))
705 return;
706
707 list_del(&system->list);
708
709 if (filter) {
710 kfree(filter->filter_string);
711 kfree(filter);
712 }
713 kfree_const(system->name);
714 kfree(system);
715 }
716
717 static void __get_system(struct event_subsystem *system)
718 {
719 WARN_ON_ONCE(system_refcount(system) == 0);
720 system_refcount_inc(system);
721 }
722
723 static void __get_system_dir(struct trace_subsystem_dir *dir)
724 {
725 WARN_ON_ONCE(dir->ref_count == 0);
726 dir->ref_count++;
727 __get_system(dir->subsystem);
728 }
729
730 static void __put_system_dir(struct trace_subsystem_dir *dir)
731 {
732 WARN_ON_ONCE(dir->ref_count == 0);
733 /* If the subsystem is about to be freed, the dir must be too */
734 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
735
736 __put_system(dir->subsystem);
737 if (!--dir->ref_count)
738 kfree(dir);
739 }
740
741 static void put_system(struct trace_subsystem_dir *dir)
742 {
743 mutex_lock(&event_mutex);
744 __put_system_dir(dir);
745 mutex_unlock(&event_mutex);
746 }
747
748 static void remove_subsystem(struct trace_subsystem_dir *dir)
749 {
750 if (!dir)
751 return;
752
753 if (!--dir->nr_events) {
754 tracefs_remove_recursive(dir->entry);
755 list_del(&dir->list);
756 __put_system_dir(dir);
757 }
758 }
759
760 static void remove_event_file_dir(struct trace_event_file *file)
761 {
762 struct dentry *dir = file->dir;
763 struct dentry *child;
764
765 if (dir) {
766 spin_lock(&dir->d_lock); /* probably unneeded */
767 list_for_each_entry(child, &dir->d_subdirs, d_child) {
768 if (d_really_is_positive(child)) /* probably unneeded */
769 d_inode(child)->i_private = NULL;
770 }
771 spin_unlock(&dir->d_lock);
772
773 tracefs_remove_recursive(dir);
774 }
775
776 list_del(&file->list);
777 remove_subsystem(file->system);
778 free_event_filter(file->filter);
779 kmem_cache_free(file_cachep, file);
780 }
781
782 /*
783 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
784 */
785 static int
786 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
787 const char *sub, const char *event, int set)
788 {
789 struct trace_event_file *file;
790 struct trace_event_call *call;
791 const char *name;
792 int ret = -EINVAL;
793
794 list_for_each_entry(file, &tr->events, list) {
795
796 call = file->event_call;
797 name = trace_event_name(call);
798
799 if (!name || !call->class || !call->class->reg)
800 continue;
801
802 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
803 continue;
804
805 if (match &&
806 strcmp(match, name) != 0 &&
807 strcmp(match, call->class->system) != 0)
808 continue;
809
810 if (sub && strcmp(sub, call->class->system) != 0)
811 continue;
812
813 if (event && strcmp(event, name) != 0)
814 continue;
815
816 ftrace_event_enable_disable(file, set);
817
818 ret = 0;
819 }
820
821 return ret;
822 }
823
824 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
825 const char *sub, const char *event, int set)
826 {
827 int ret;
828
829 mutex_lock(&event_mutex);
830 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
831 mutex_unlock(&event_mutex);
832
833 return ret;
834 }
835
836 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
837 {
838 char *event = NULL, *sub = NULL, *match;
839 int ret;
840
841 /*
842 * The buf format can be <subsystem>:<event-name>
843 * *:<event-name> means any event by that name.
844 * :<event-name> is the same.
845 *
846 * <subsystem>:* means all events in that subsystem
847 * <subsystem>: means the same.
848 *
849 * <name> (no ':') means all events in a subsystem with
850 * the name <name> or any event that matches <name>
851 */
852
853 match = strsep(&buf, ":");
854 if (buf) {
855 sub = match;
856 event = buf;
857 match = NULL;
858
859 if (!strlen(sub) || strcmp(sub, "*") == 0)
860 sub = NULL;
861 if (!strlen(event) || strcmp(event, "*") == 0)
862 event = NULL;
863 }
864
865 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
866
867 /* Put back the colon to allow this to be called again */
868 if (buf)
869 *(buf - 1) = ':';
870
871 return ret;
872 }
873
874 /**
875 * trace_set_clr_event - enable or disable an event
876 * @system: system name to match (NULL for any system)
877 * @event: event name to match (NULL for all events, within system)
878 * @set: 1 to enable, 0 to disable
879 *
880 * This is a way for other parts of the kernel to enable or disable
881 * event recording.
882 *
883 * Returns 0 on success, -EINVAL if the parameters do not match any
884 * registered events.
885 */
886 int trace_set_clr_event(const char *system, const char *event, int set)
887 {
888 struct trace_array *tr = top_trace_array();
889
890 if (!tr)
891 return -ENODEV;
892
893 return __ftrace_set_clr_event(tr, NULL, system, event, set);
894 }
895 EXPORT_SYMBOL_GPL(trace_set_clr_event);
896
897 /* 128 should be much more than enough */
898 #define EVENT_BUF_SIZE 127
899
900 static ssize_t
901 ftrace_event_write(struct file *file, const char __user *ubuf,
902 size_t cnt, loff_t *ppos)
903 {
904 struct trace_parser parser;
905 struct seq_file *m = file->private_data;
906 struct trace_array *tr = m->private;
907 ssize_t read, ret;
908
909 if (!cnt)
910 return 0;
911
912 ret = tracing_update_buffers();
913 if (ret < 0)
914 return ret;
915
916 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
917 return -ENOMEM;
918
919 read = trace_get_user(&parser, ubuf, cnt, ppos);
920
921 if (read >= 0 && trace_parser_loaded((&parser))) {
922 int set = 1;
923
924 if (*parser.buffer == '!')
925 set = 0;
926
927 parser.buffer[parser.idx] = 0;
928
929 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
930 if (ret)
931 goto out_put;
932 }
933
934 ret = read;
935
936 out_put:
937 trace_parser_put(&parser);
938
939 return ret;
940 }
941
942 static void *
943 t_next(struct seq_file *m, void *v, loff_t *pos)
944 {
945 struct trace_event_file *file = v;
946 struct trace_event_call *call;
947 struct trace_array *tr = m->private;
948
949 (*pos)++;
950
951 list_for_each_entry_continue(file, &tr->events, list) {
952 call = file->event_call;
953 /*
954 * The ftrace subsystem is for showing formats only.
955 * They can not be enabled or disabled via the event files.
956 */
957 if (call->class && call->class->reg &&
958 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
959 return file;
960 }
961
962 return NULL;
963 }
964
965 static void *t_start(struct seq_file *m, loff_t *pos)
966 {
967 struct trace_event_file *file;
968 struct trace_array *tr = m->private;
969 loff_t l;
970
971 mutex_lock(&event_mutex);
972
973 file = list_entry(&tr->events, struct trace_event_file, list);
974 for (l = 0; l <= *pos; ) {
975 file = t_next(m, file, &l);
976 if (!file)
977 break;
978 }
979 return file;
980 }
981
982 static void *
983 s_next(struct seq_file *m, void *v, loff_t *pos)
984 {
985 struct trace_event_file *file = v;
986 struct trace_array *tr = m->private;
987
988 (*pos)++;
989
990 list_for_each_entry_continue(file, &tr->events, list) {
991 if (file->flags & EVENT_FILE_FL_ENABLED)
992 return file;
993 }
994
995 return NULL;
996 }
997
998 static void *s_start(struct seq_file *m, loff_t *pos)
999 {
1000 struct trace_event_file *file;
1001 struct trace_array *tr = m->private;
1002 loff_t l;
1003
1004 mutex_lock(&event_mutex);
1005
1006 file = list_entry(&tr->events, struct trace_event_file, list);
1007 for (l = 0; l <= *pos; ) {
1008 file = s_next(m, file, &l);
1009 if (!file)
1010 break;
1011 }
1012 return file;
1013 }
1014
1015 static int t_show(struct seq_file *m, void *v)
1016 {
1017 struct trace_event_file *file = v;
1018 struct trace_event_call *call = file->event_call;
1019
1020 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1021 seq_printf(m, "%s:", call->class->system);
1022 seq_printf(m, "%s\n", trace_event_name(call));
1023
1024 return 0;
1025 }
1026
1027 static void t_stop(struct seq_file *m, void *p)
1028 {
1029 mutex_unlock(&event_mutex);
1030 }
1031
1032 static void *
1033 p_next(struct seq_file *m, void *v, loff_t *pos)
1034 {
1035 struct trace_array *tr = m->private;
1036 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
1037 unsigned long pid = (unsigned long)v;
1038
1039 (*pos)++;
1040
1041 /* pid already is +1 of the actual prevous bit */
1042 pid = find_next_bit(pid_list->pids, pid_list->pid_max, pid);
1043
1044 /* Return pid + 1 to allow zero to be represented */
1045 if (pid < pid_list->pid_max)
1046 return (void *)(pid + 1);
1047
1048 return NULL;
1049 }
1050
1051 static void *p_start(struct seq_file *m, loff_t *pos)
1052 __acquires(RCU)
1053 {
1054 struct trace_pid_list *pid_list;
1055 struct trace_array *tr = m->private;
1056 unsigned long pid;
1057 loff_t l = 0;
1058
1059 /*
1060 * Grab the mutex, to keep calls to p_next() having the same
1061 * tr->filtered_pids as p_start() has.
1062 * If we just passed the tr->filtered_pids around, then RCU would
1063 * have been enough, but doing that makes things more complex.
1064 */
1065 mutex_lock(&event_mutex);
1066 rcu_read_lock_sched();
1067
1068 pid_list = rcu_dereference_sched(tr->filtered_pids);
1069
1070 if (!pid_list)
1071 return NULL;
1072
1073 pid = find_first_bit(pid_list->pids, pid_list->pid_max);
1074 if (pid >= pid_list->pid_max)
1075 return NULL;
1076
1077 /* Return pid + 1 so that zero can be the exit value */
1078 for (pid++; pid && l < *pos;
1079 pid = (unsigned long)p_next(m, (void *)pid, &l))
1080 ;
1081 return (void *)pid;
1082 }
1083
1084 static void p_stop(struct seq_file *m, void *p)
1085 __releases(RCU)
1086 {
1087 rcu_read_unlock_sched();
1088 mutex_unlock(&event_mutex);
1089 }
1090
1091 static int p_show(struct seq_file *m, void *v)
1092 {
1093 unsigned long pid = (unsigned long)v - 1;
1094
1095 seq_printf(m, "%lu\n", pid);
1096 return 0;
1097 }
1098
1099 static ssize_t
1100 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1101 loff_t *ppos)
1102 {
1103 struct trace_event_file *file;
1104 unsigned long flags;
1105 char buf[4] = "0";
1106
1107 mutex_lock(&event_mutex);
1108 file = event_file_data(filp);
1109 if (likely(file))
1110 flags = file->flags;
1111 mutex_unlock(&event_mutex);
1112
1113 if (!file)
1114 return -ENODEV;
1115
1116 if (flags & EVENT_FILE_FL_ENABLED &&
1117 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1118 strcpy(buf, "1");
1119
1120 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1121 flags & EVENT_FILE_FL_SOFT_MODE)
1122 strcat(buf, "*");
1123
1124 strcat(buf, "\n");
1125
1126 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1127 }
1128
1129 static ssize_t
1130 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1131 loff_t *ppos)
1132 {
1133 struct trace_event_file *file;
1134 unsigned long val;
1135 int ret;
1136
1137 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1138 if (ret)
1139 return ret;
1140
1141 ret = tracing_update_buffers();
1142 if (ret < 0)
1143 return ret;
1144
1145 switch (val) {
1146 case 0:
1147 case 1:
1148 ret = -ENODEV;
1149 mutex_lock(&event_mutex);
1150 file = event_file_data(filp);
1151 if (likely(file))
1152 ret = ftrace_event_enable_disable(file, val);
1153 mutex_unlock(&event_mutex);
1154 break;
1155
1156 default:
1157 return -EINVAL;
1158 }
1159
1160 *ppos += cnt;
1161
1162 return ret ? ret : cnt;
1163 }
1164
1165 static ssize_t
1166 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1167 loff_t *ppos)
1168 {
1169 const char set_to_char[4] = { '?', '0', '1', 'X' };
1170 struct trace_subsystem_dir *dir = filp->private_data;
1171 struct event_subsystem *system = dir->subsystem;
1172 struct trace_event_call *call;
1173 struct trace_event_file *file;
1174 struct trace_array *tr = dir->tr;
1175 char buf[2];
1176 int set = 0;
1177 int ret;
1178
1179 mutex_lock(&event_mutex);
1180 list_for_each_entry(file, &tr->events, list) {
1181 call = file->event_call;
1182 if (!trace_event_name(call) || !call->class || !call->class->reg)
1183 continue;
1184
1185 if (system && strcmp(call->class->system, system->name) != 0)
1186 continue;
1187
1188 /*
1189 * We need to find out if all the events are set
1190 * or if all events or cleared, or if we have
1191 * a mixture.
1192 */
1193 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1194
1195 /*
1196 * If we have a mixture, no need to look further.
1197 */
1198 if (set == 3)
1199 break;
1200 }
1201 mutex_unlock(&event_mutex);
1202
1203 buf[0] = set_to_char[set];
1204 buf[1] = '\n';
1205
1206 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1207
1208 return ret;
1209 }
1210
1211 static ssize_t
1212 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1213 loff_t *ppos)
1214 {
1215 struct trace_subsystem_dir *dir = filp->private_data;
1216 struct event_subsystem *system = dir->subsystem;
1217 const char *name = NULL;
1218 unsigned long val;
1219 ssize_t ret;
1220
1221 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1222 if (ret)
1223 return ret;
1224
1225 ret = tracing_update_buffers();
1226 if (ret < 0)
1227 return ret;
1228
1229 if (val != 0 && val != 1)
1230 return -EINVAL;
1231
1232 /*
1233 * Opening of "enable" adds a ref count to system,
1234 * so the name is safe to use.
1235 */
1236 if (system)
1237 name = system->name;
1238
1239 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1240 if (ret)
1241 goto out;
1242
1243 ret = cnt;
1244
1245 out:
1246 *ppos += cnt;
1247
1248 return ret;
1249 }
1250
1251 enum {
1252 FORMAT_HEADER = 1,
1253 FORMAT_FIELD_SEPERATOR = 2,
1254 FORMAT_PRINTFMT = 3,
1255 };
1256
1257 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1258 {
1259 struct trace_event_call *call = event_file_data(m->private);
1260 struct list_head *common_head = &ftrace_common_fields;
1261 struct list_head *head = trace_get_fields(call);
1262 struct list_head *node = v;
1263
1264 (*pos)++;
1265
1266 switch ((unsigned long)v) {
1267 case FORMAT_HEADER:
1268 node = common_head;
1269 break;
1270
1271 case FORMAT_FIELD_SEPERATOR:
1272 node = head;
1273 break;
1274
1275 case FORMAT_PRINTFMT:
1276 /* all done */
1277 return NULL;
1278 }
1279
1280 node = node->prev;
1281 if (node == common_head)
1282 return (void *)FORMAT_FIELD_SEPERATOR;
1283 else if (node == head)
1284 return (void *)FORMAT_PRINTFMT;
1285 else
1286 return node;
1287 }
1288
1289 static int f_show(struct seq_file *m, void *v)
1290 {
1291 struct trace_event_call *call = event_file_data(m->private);
1292 struct ftrace_event_field *field;
1293 const char *array_descriptor;
1294
1295 switch ((unsigned long)v) {
1296 case FORMAT_HEADER:
1297 seq_printf(m, "name: %s\n", trace_event_name(call));
1298 seq_printf(m, "ID: %d\n", call->event.type);
1299 seq_puts(m, "format:\n");
1300 return 0;
1301
1302 case FORMAT_FIELD_SEPERATOR:
1303 seq_putc(m, '\n');
1304 return 0;
1305
1306 case FORMAT_PRINTFMT:
1307 seq_printf(m, "\nprint fmt: %s\n",
1308 call->print_fmt);
1309 return 0;
1310 }
1311
1312 field = list_entry(v, struct ftrace_event_field, link);
1313 /*
1314 * Smartly shows the array type(except dynamic array).
1315 * Normal:
1316 * field:TYPE VAR
1317 * If TYPE := TYPE[LEN], it is shown:
1318 * field:TYPE VAR[LEN]
1319 */
1320 array_descriptor = strchr(field->type, '[');
1321
1322 if (!strncmp(field->type, "__data_loc", 10))
1323 array_descriptor = NULL;
1324
1325 if (!array_descriptor)
1326 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1327 field->type, field->name, field->offset,
1328 field->size, !!field->is_signed);
1329 else
1330 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1331 (int)(array_descriptor - field->type),
1332 field->type, field->name,
1333 array_descriptor, field->offset,
1334 field->size, !!field->is_signed);
1335
1336 return 0;
1337 }
1338
1339 static void *f_start(struct seq_file *m, loff_t *pos)
1340 {
1341 void *p = (void *)FORMAT_HEADER;
1342 loff_t l = 0;
1343
1344 /* ->stop() is called even if ->start() fails */
1345 mutex_lock(&event_mutex);
1346 if (!event_file_data(m->private))
1347 return ERR_PTR(-ENODEV);
1348
1349 while (l < *pos && p)
1350 p = f_next(m, p, &l);
1351
1352 return p;
1353 }
1354
1355 static void f_stop(struct seq_file *m, void *p)
1356 {
1357 mutex_unlock(&event_mutex);
1358 }
1359
1360 static const struct seq_operations trace_format_seq_ops = {
1361 .start = f_start,
1362 .next = f_next,
1363 .stop = f_stop,
1364 .show = f_show,
1365 };
1366
1367 static int trace_format_open(struct inode *inode, struct file *file)
1368 {
1369 struct seq_file *m;
1370 int ret;
1371
1372 ret = seq_open(file, &trace_format_seq_ops);
1373 if (ret < 0)
1374 return ret;
1375
1376 m = file->private_data;
1377 m->private = file;
1378
1379 return 0;
1380 }
1381
1382 static ssize_t
1383 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1384 {
1385 int id = (long)event_file_data(filp);
1386 char buf[32];
1387 int len;
1388
1389 if (*ppos)
1390 return 0;
1391
1392 if (unlikely(!id))
1393 return -ENODEV;
1394
1395 len = sprintf(buf, "%d\n", id);
1396
1397 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1398 }
1399
1400 static ssize_t
1401 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1402 loff_t *ppos)
1403 {
1404 struct trace_event_file *file;
1405 struct trace_seq *s;
1406 int r = -ENODEV;
1407
1408 if (*ppos)
1409 return 0;
1410
1411 s = kmalloc(sizeof(*s), GFP_KERNEL);
1412
1413 if (!s)
1414 return -ENOMEM;
1415
1416 trace_seq_init(s);
1417
1418 mutex_lock(&event_mutex);
1419 file = event_file_data(filp);
1420 if (file)
1421 print_event_filter(file, s);
1422 mutex_unlock(&event_mutex);
1423
1424 if (file)
1425 r = simple_read_from_buffer(ubuf, cnt, ppos,
1426 s->buffer, trace_seq_used(s));
1427
1428 kfree(s);
1429
1430 return r;
1431 }
1432
1433 static ssize_t
1434 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1435 loff_t *ppos)
1436 {
1437 struct trace_event_file *file;
1438 char *buf;
1439 int err = -ENODEV;
1440
1441 if (cnt >= PAGE_SIZE)
1442 return -EINVAL;
1443
1444 buf = memdup_user_nul(ubuf, cnt);
1445 if (IS_ERR(buf))
1446 return PTR_ERR(buf);
1447
1448 mutex_lock(&event_mutex);
1449 file = event_file_data(filp);
1450 if (file)
1451 err = apply_event_filter(file, buf);
1452 mutex_unlock(&event_mutex);
1453
1454 kfree(buf);
1455 if (err < 0)
1456 return err;
1457
1458 *ppos += cnt;
1459
1460 return cnt;
1461 }
1462
1463 static LIST_HEAD(event_subsystems);
1464
1465 static int subsystem_open(struct inode *inode, struct file *filp)
1466 {
1467 struct event_subsystem *system = NULL;
1468 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1469 struct trace_array *tr;
1470 int ret;
1471
1472 if (tracing_is_disabled())
1473 return -ENODEV;
1474
1475 /* Make sure the system still exists */
1476 mutex_lock(&trace_types_lock);
1477 mutex_lock(&event_mutex);
1478 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1479 list_for_each_entry(dir, &tr->systems, list) {
1480 if (dir == inode->i_private) {
1481 /* Don't open systems with no events */
1482 if (dir->nr_events) {
1483 __get_system_dir(dir);
1484 system = dir->subsystem;
1485 }
1486 goto exit_loop;
1487 }
1488 }
1489 }
1490 exit_loop:
1491 mutex_unlock(&event_mutex);
1492 mutex_unlock(&trace_types_lock);
1493
1494 if (!system)
1495 return -ENODEV;
1496
1497 /* Some versions of gcc think dir can be uninitialized here */
1498 WARN_ON(!dir);
1499
1500 /* Still need to increment the ref count of the system */
1501 if (trace_array_get(tr) < 0) {
1502 put_system(dir);
1503 return -ENODEV;
1504 }
1505
1506 ret = tracing_open_generic(inode, filp);
1507 if (ret < 0) {
1508 trace_array_put(tr);
1509 put_system(dir);
1510 }
1511
1512 return ret;
1513 }
1514
1515 static int system_tr_open(struct inode *inode, struct file *filp)
1516 {
1517 struct trace_subsystem_dir *dir;
1518 struct trace_array *tr = inode->i_private;
1519 int ret;
1520
1521 if (tracing_is_disabled())
1522 return -ENODEV;
1523
1524 if (trace_array_get(tr) < 0)
1525 return -ENODEV;
1526
1527 /* Make a temporary dir that has no system but points to tr */
1528 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1529 if (!dir) {
1530 trace_array_put(tr);
1531 return -ENOMEM;
1532 }
1533
1534 dir->tr = tr;
1535
1536 ret = tracing_open_generic(inode, filp);
1537 if (ret < 0) {
1538 trace_array_put(tr);
1539 kfree(dir);
1540 return ret;
1541 }
1542
1543 filp->private_data = dir;
1544
1545 return 0;
1546 }
1547
1548 static int subsystem_release(struct inode *inode, struct file *file)
1549 {
1550 struct trace_subsystem_dir *dir = file->private_data;
1551
1552 trace_array_put(dir->tr);
1553
1554 /*
1555 * If dir->subsystem is NULL, then this is a temporary
1556 * descriptor that was made for a trace_array to enable
1557 * all subsystems.
1558 */
1559 if (dir->subsystem)
1560 put_system(dir);
1561 else
1562 kfree(dir);
1563
1564 return 0;
1565 }
1566
1567 static ssize_t
1568 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1569 loff_t *ppos)
1570 {
1571 struct trace_subsystem_dir *dir = filp->private_data;
1572 struct event_subsystem *system = dir->subsystem;
1573 struct trace_seq *s;
1574 int r;
1575
1576 if (*ppos)
1577 return 0;
1578
1579 s = kmalloc(sizeof(*s), GFP_KERNEL);
1580 if (!s)
1581 return -ENOMEM;
1582
1583 trace_seq_init(s);
1584
1585 print_subsystem_event_filter(system, s);
1586 r = simple_read_from_buffer(ubuf, cnt, ppos,
1587 s->buffer, trace_seq_used(s));
1588
1589 kfree(s);
1590
1591 return r;
1592 }
1593
1594 static ssize_t
1595 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1596 loff_t *ppos)
1597 {
1598 struct trace_subsystem_dir *dir = filp->private_data;
1599 char *buf;
1600 int err;
1601
1602 if (cnt >= PAGE_SIZE)
1603 return -EINVAL;
1604
1605 buf = memdup_user_nul(ubuf, cnt);
1606 if (IS_ERR(buf))
1607 return PTR_ERR(buf);
1608
1609 err = apply_subsystem_event_filter(dir, buf);
1610 kfree(buf);
1611 if (err < 0)
1612 return err;
1613
1614 *ppos += cnt;
1615
1616 return cnt;
1617 }
1618
1619 static ssize_t
1620 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1621 {
1622 int (*func)(struct trace_seq *s) = filp->private_data;
1623 struct trace_seq *s;
1624 int r;
1625
1626 if (*ppos)
1627 return 0;
1628
1629 s = kmalloc(sizeof(*s), GFP_KERNEL);
1630 if (!s)
1631 return -ENOMEM;
1632
1633 trace_seq_init(s);
1634
1635 func(s);
1636 r = simple_read_from_buffer(ubuf, cnt, ppos,
1637 s->buffer, trace_seq_used(s));
1638
1639 kfree(s);
1640
1641 return r;
1642 }
1643
1644 static void ignore_task_cpu(void *data)
1645 {
1646 struct trace_array *tr = data;
1647 struct trace_pid_list *pid_list;
1648
1649 /*
1650 * This function is called by on_each_cpu() while the
1651 * event_mutex is held.
1652 */
1653 pid_list = rcu_dereference_protected(tr->filtered_pids,
1654 mutex_is_locked(&event_mutex));
1655
1656 this_cpu_write(tr->trace_buffer.data->ignore_pid,
1657 ignore_this_task(pid_list, current));
1658 }
1659
1660 static ssize_t
1661 ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1662 size_t cnt, loff_t *ppos)
1663 {
1664 struct seq_file *m = filp->private_data;
1665 struct trace_array *tr = m->private;
1666 struct trace_pid_list *filtered_pids = NULL;
1667 struct trace_pid_list *pid_list;
1668 struct trace_event_file *file;
1669 struct trace_parser parser;
1670 unsigned long val;
1671 loff_t this_pos;
1672 ssize_t read = 0;
1673 ssize_t ret = 0;
1674 pid_t pid;
1675 int nr_pids = 0;
1676
1677 if (!cnt)
1678 return 0;
1679
1680 ret = tracing_update_buffers();
1681 if (ret < 0)
1682 return ret;
1683
1684 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
1685 return -ENOMEM;
1686
1687 mutex_lock(&event_mutex);
1688 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1689 lockdep_is_held(&event_mutex));
1690
1691 /*
1692 * Always recreate a new array. The write is an all or nothing
1693 * operation. Always create a new array when adding new pids by
1694 * the user. If the operation fails, then the current list is
1695 * not modified.
1696 */
1697 pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL);
1698 if (!pid_list) {
1699 read = -ENOMEM;
1700 goto out;
1701 }
1702 pid_list->pid_max = READ_ONCE(pid_max);
1703 /* Only truncating will shrink pid_max */
1704 if (filtered_pids && filtered_pids->pid_max > pid_list->pid_max)
1705 pid_list->pid_max = filtered_pids->pid_max;
1706 pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3);
1707 if (!pid_list->pids) {
1708 kfree(pid_list);
1709 read = -ENOMEM;
1710 goto out;
1711 }
1712 if (filtered_pids) {
1713 /* copy the current bits to the new max */
1714 pid = find_first_bit(filtered_pids->pids,
1715 filtered_pids->pid_max);
1716 while (pid < filtered_pids->pid_max) {
1717 set_bit(pid, pid_list->pids);
1718 pid = find_next_bit(filtered_pids->pids,
1719 filtered_pids->pid_max,
1720 pid + 1);
1721 nr_pids++;
1722 }
1723 }
1724
1725 while (cnt > 0) {
1726
1727 this_pos = 0;
1728
1729 ret = trace_get_user(&parser, ubuf, cnt, &this_pos);
1730 if (ret < 0 || !trace_parser_loaded(&parser))
1731 break;
1732
1733 read += ret;
1734 ubuf += ret;
1735 cnt -= ret;
1736
1737 parser.buffer[parser.idx] = 0;
1738
1739 ret = -EINVAL;
1740 if (kstrtoul(parser.buffer, 0, &val))
1741 break;
1742 if (val >= pid_list->pid_max)
1743 break;
1744
1745 pid = (pid_t)val;
1746
1747 set_bit(pid, pid_list->pids);
1748 nr_pids++;
1749
1750 trace_parser_clear(&parser);
1751 ret = 0;
1752 }
1753 trace_parser_put(&parser);
1754
1755 if (ret < 0) {
1756 vfree(pid_list->pids);
1757 kfree(pid_list);
1758 read = ret;
1759 goto out;
1760 }
1761
1762 if (!nr_pids) {
1763 /* Cleared the list of pids */
1764 vfree(pid_list->pids);
1765 kfree(pid_list);
1766 read = ret;
1767 if (!filtered_pids)
1768 goto out;
1769 pid_list = NULL;
1770 }
1771 rcu_assign_pointer(tr->filtered_pids, pid_list);
1772
1773 list_for_each_entry(file, &tr->events, list) {
1774 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1775 }
1776
1777 if (filtered_pids) {
1778 synchronize_sched();
1779
1780 vfree(filtered_pids->pids);
1781 kfree(filtered_pids);
1782 } else {
1783 /*
1784 * Register a probe that is called before all other probes
1785 * to set ignore_pid if next or prev do not match.
1786 * Register a probe this is called after all other probes
1787 * to only keep ignore_pid set if next pid matches.
1788 */
1789 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1790 tr, INT_MAX);
1791 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1792 tr, 0);
1793
1794 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1795 tr, INT_MAX);
1796 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1797 tr, 0);
1798
1799 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1800 tr, INT_MAX);
1801 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1802 tr, 0);
1803
1804 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1805 tr, INT_MAX);
1806 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1807 tr, 0);
1808 }
1809
1810 /*
1811 * Ignoring of pids is done at task switch. But we have to
1812 * check for those tasks that are currently running.
1813 * Always do this in case a pid was appended or removed.
1814 */
1815 on_each_cpu(ignore_task_cpu, tr, 1);
1816
1817 out:
1818 mutex_unlock(&event_mutex);
1819
1820 ret = read;
1821 if (read > 0)
1822 *ppos += read;
1823
1824 return ret;
1825 }
1826
1827 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1828 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1829 static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
1830 static int ftrace_event_release(struct inode *inode, struct file *file);
1831
1832 static const struct seq_operations show_event_seq_ops = {
1833 .start = t_start,
1834 .next = t_next,
1835 .show = t_show,
1836 .stop = t_stop,
1837 };
1838
1839 static const struct seq_operations show_set_event_seq_ops = {
1840 .start = s_start,
1841 .next = s_next,
1842 .show = t_show,
1843 .stop = t_stop,
1844 };
1845
1846 static const struct seq_operations show_set_pid_seq_ops = {
1847 .start = p_start,
1848 .next = p_next,
1849 .show = p_show,
1850 .stop = p_stop,
1851 };
1852
1853 static const struct file_operations ftrace_avail_fops = {
1854 .open = ftrace_event_avail_open,
1855 .read = seq_read,
1856 .llseek = seq_lseek,
1857 .release = seq_release,
1858 };
1859
1860 static const struct file_operations ftrace_set_event_fops = {
1861 .open = ftrace_event_set_open,
1862 .read = seq_read,
1863 .write = ftrace_event_write,
1864 .llseek = seq_lseek,
1865 .release = ftrace_event_release,
1866 };
1867
1868 static const struct file_operations ftrace_set_event_pid_fops = {
1869 .open = ftrace_event_set_pid_open,
1870 .read = seq_read,
1871 .write = ftrace_event_pid_write,
1872 .llseek = seq_lseek,
1873 .release = ftrace_event_release,
1874 };
1875
1876 static const struct file_operations ftrace_enable_fops = {
1877 .open = tracing_open_generic,
1878 .read = event_enable_read,
1879 .write = event_enable_write,
1880 .llseek = default_llseek,
1881 };
1882
1883 static const struct file_operations ftrace_event_format_fops = {
1884 .open = trace_format_open,
1885 .read = seq_read,
1886 .llseek = seq_lseek,
1887 .release = seq_release,
1888 };
1889
1890 static const struct file_operations ftrace_event_id_fops = {
1891 .read = event_id_read,
1892 .llseek = default_llseek,
1893 };
1894
1895 static const struct file_operations ftrace_event_filter_fops = {
1896 .open = tracing_open_generic,
1897 .read = event_filter_read,
1898 .write = event_filter_write,
1899 .llseek = default_llseek,
1900 };
1901
1902 static const struct file_operations ftrace_subsystem_filter_fops = {
1903 .open = subsystem_open,
1904 .read = subsystem_filter_read,
1905 .write = subsystem_filter_write,
1906 .llseek = default_llseek,
1907 .release = subsystem_release,
1908 };
1909
1910 static const struct file_operations ftrace_system_enable_fops = {
1911 .open = subsystem_open,
1912 .read = system_enable_read,
1913 .write = system_enable_write,
1914 .llseek = default_llseek,
1915 .release = subsystem_release,
1916 };
1917
1918 static const struct file_operations ftrace_tr_enable_fops = {
1919 .open = system_tr_open,
1920 .read = system_enable_read,
1921 .write = system_enable_write,
1922 .llseek = default_llseek,
1923 .release = subsystem_release,
1924 };
1925
1926 static const struct file_operations ftrace_show_header_fops = {
1927 .open = tracing_open_generic,
1928 .read = show_header,
1929 .llseek = default_llseek,
1930 };
1931
1932 static int
1933 ftrace_event_open(struct inode *inode, struct file *file,
1934 const struct seq_operations *seq_ops)
1935 {
1936 struct seq_file *m;
1937 int ret;
1938
1939 ret = seq_open(file, seq_ops);
1940 if (ret < 0)
1941 return ret;
1942 m = file->private_data;
1943 /* copy tr over to seq ops */
1944 m->private = inode->i_private;
1945
1946 return ret;
1947 }
1948
1949 static int ftrace_event_release(struct inode *inode, struct file *file)
1950 {
1951 struct trace_array *tr = inode->i_private;
1952
1953 trace_array_put(tr);
1954
1955 return seq_release(inode, file);
1956 }
1957
1958 static int
1959 ftrace_event_avail_open(struct inode *inode, struct file *file)
1960 {
1961 const struct seq_operations *seq_ops = &show_event_seq_ops;
1962
1963 return ftrace_event_open(inode, file, seq_ops);
1964 }
1965
1966 static int
1967 ftrace_event_set_open(struct inode *inode, struct file *file)
1968 {
1969 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1970 struct trace_array *tr = inode->i_private;
1971 int ret;
1972
1973 if (trace_array_get(tr) < 0)
1974 return -ENODEV;
1975
1976 if ((file->f_mode & FMODE_WRITE) &&
1977 (file->f_flags & O_TRUNC))
1978 ftrace_clear_events(tr);
1979
1980 ret = ftrace_event_open(inode, file, seq_ops);
1981 if (ret < 0)
1982 trace_array_put(tr);
1983 return ret;
1984 }
1985
1986 static int
1987 ftrace_event_set_pid_open(struct inode *inode, struct file *file)
1988 {
1989 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
1990 struct trace_array *tr = inode->i_private;
1991 int ret;
1992
1993 if (trace_array_get(tr) < 0)
1994 return -ENODEV;
1995
1996 if ((file->f_mode & FMODE_WRITE) &&
1997 (file->f_flags & O_TRUNC))
1998 ftrace_clear_event_pids(tr);
1999
2000 ret = ftrace_event_open(inode, file, seq_ops);
2001 if (ret < 0)
2002 trace_array_put(tr);
2003 return ret;
2004 }
2005
2006 static struct event_subsystem *
2007 create_new_subsystem(const char *name)
2008 {
2009 struct event_subsystem *system;
2010
2011 /* need to create new entry */
2012 system = kmalloc(sizeof(*system), GFP_KERNEL);
2013 if (!system)
2014 return NULL;
2015
2016 system->ref_count = 1;
2017
2018 /* Only allocate if dynamic (kprobes and modules) */
2019 system->name = kstrdup_const(name, GFP_KERNEL);
2020 if (!system->name)
2021 goto out_free;
2022
2023 system->filter = NULL;
2024
2025 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
2026 if (!system->filter)
2027 goto out_free;
2028
2029 list_add(&system->list, &event_subsystems);
2030
2031 return system;
2032
2033 out_free:
2034 kfree_const(system->name);
2035 kfree(system);
2036 return NULL;
2037 }
2038
2039 static struct dentry *
2040 event_subsystem_dir(struct trace_array *tr, const char *name,
2041 struct trace_event_file *file, struct dentry *parent)
2042 {
2043 struct trace_subsystem_dir *dir;
2044 struct event_subsystem *system;
2045 struct dentry *entry;
2046
2047 /* First see if we did not already create this dir */
2048 list_for_each_entry(dir, &tr->systems, list) {
2049 system = dir->subsystem;
2050 if (strcmp(system->name, name) == 0) {
2051 dir->nr_events++;
2052 file->system = dir;
2053 return dir->entry;
2054 }
2055 }
2056
2057 /* Now see if the system itself exists. */
2058 list_for_each_entry(system, &event_subsystems, list) {
2059 if (strcmp(system->name, name) == 0)
2060 break;
2061 }
2062 /* Reset system variable when not found */
2063 if (&system->list == &event_subsystems)
2064 system = NULL;
2065
2066 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
2067 if (!dir)
2068 goto out_fail;
2069
2070 if (!system) {
2071 system = create_new_subsystem(name);
2072 if (!system)
2073 goto out_free;
2074 } else
2075 __get_system(system);
2076
2077 dir->entry = tracefs_create_dir(name, parent);
2078 if (!dir->entry) {
2079 pr_warn("Failed to create system directory %s\n", name);
2080 __put_system(system);
2081 goto out_free;
2082 }
2083
2084 dir->tr = tr;
2085 dir->ref_count = 1;
2086 dir->nr_events = 1;
2087 dir->subsystem = system;
2088 file->system = dir;
2089
2090 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
2091 &ftrace_subsystem_filter_fops);
2092 if (!entry) {
2093 kfree(system->filter);
2094 system->filter = NULL;
2095 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
2096 }
2097
2098 trace_create_file("enable", 0644, dir->entry, dir,
2099 &ftrace_system_enable_fops);
2100
2101 list_add(&dir->list, &tr->systems);
2102
2103 return dir->entry;
2104
2105 out_free:
2106 kfree(dir);
2107 out_fail:
2108 /* Only print this message if failed on memory allocation */
2109 if (!dir || !system)
2110 pr_warn("No memory to create event subsystem %s\n", name);
2111 return NULL;
2112 }
2113
2114 static int
2115 event_create_dir(struct dentry *parent, struct trace_event_file *file)
2116 {
2117 struct trace_event_call *call = file->event_call;
2118 struct trace_array *tr = file->tr;
2119 struct list_head *head;
2120 struct dentry *d_events;
2121 const char *name;
2122 int ret;
2123
2124 /*
2125 * If the trace point header did not define TRACE_SYSTEM
2126 * then the system would be called "TRACE_SYSTEM".
2127 */
2128 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
2129 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
2130 if (!d_events)
2131 return -ENOMEM;
2132 } else
2133 d_events = parent;
2134
2135 name = trace_event_name(call);
2136 file->dir = tracefs_create_dir(name, d_events);
2137 if (!file->dir) {
2138 pr_warn("Could not create tracefs '%s' directory\n", name);
2139 return -1;
2140 }
2141
2142 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2143 trace_create_file("enable", 0644, file->dir, file,
2144 &ftrace_enable_fops);
2145
2146 #ifdef CONFIG_PERF_EVENTS
2147 if (call->event.type && call->class->reg)
2148 trace_create_file("id", 0444, file->dir,
2149 (void *)(long)call->event.type,
2150 &ftrace_event_id_fops);
2151 #endif
2152
2153 /*
2154 * Other events may have the same class. Only update
2155 * the fields if they are not already defined.
2156 */
2157 head = trace_get_fields(call);
2158 if (list_empty(head)) {
2159 ret = call->class->define_fields(call);
2160 if (ret < 0) {
2161 pr_warn("Could not initialize trace point events/%s\n",
2162 name);
2163 return -1;
2164 }
2165 }
2166 trace_create_file("filter", 0644, file->dir, file,
2167 &ftrace_event_filter_fops);
2168
2169 /*
2170 * Only event directories that can be enabled should have
2171 * triggers.
2172 */
2173 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2174 trace_create_file("trigger", 0644, file->dir, file,
2175 &event_trigger_fops);
2176
2177 #ifdef CONFIG_HIST_TRIGGERS
2178 trace_create_file("hist", 0444, file->dir, file,
2179 &event_hist_fops);
2180 #endif
2181 trace_create_file("format", 0444, file->dir, call,
2182 &ftrace_event_format_fops);
2183
2184 return 0;
2185 }
2186
2187 static void remove_event_from_tracers(struct trace_event_call *call)
2188 {
2189 struct trace_event_file *file;
2190 struct trace_array *tr;
2191
2192 do_for_each_event_file_safe(tr, file) {
2193 if (file->event_call != call)
2194 continue;
2195
2196 remove_event_file_dir(file);
2197 /*
2198 * The do_for_each_event_file_safe() is
2199 * a double loop. After finding the call for this
2200 * trace_array, we use break to jump to the next
2201 * trace_array.
2202 */
2203 break;
2204 } while_for_each_event_file();
2205 }
2206
2207 static void event_remove(struct trace_event_call *call)
2208 {
2209 struct trace_array *tr;
2210 struct trace_event_file *file;
2211
2212 do_for_each_event_file(tr, file) {
2213 if (file->event_call != call)
2214 continue;
2215 ftrace_event_enable_disable(file, 0);
2216 /*
2217 * The do_for_each_event_file() is
2218 * a double loop. After finding the call for this
2219 * trace_array, we use break to jump to the next
2220 * trace_array.
2221 */
2222 break;
2223 } while_for_each_event_file();
2224
2225 if (call->event.funcs)
2226 __unregister_trace_event(&call->event);
2227 remove_event_from_tracers(call);
2228 list_del(&call->list);
2229 }
2230
2231 static int event_init(struct trace_event_call *call)
2232 {
2233 int ret = 0;
2234 const char *name;
2235
2236 name = trace_event_name(call);
2237 if (WARN_ON(!name))
2238 return -EINVAL;
2239
2240 if (call->class->raw_init) {
2241 ret = call->class->raw_init(call);
2242 if (ret < 0 && ret != -ENOSYS)
2243 pr_warn("Could not initialize trace events/%s\n", name);
2244 }
2245
2246 return ret;
2247 }
2248
2249 static int
2250 __register_event(struct trace_event_call *call, struct module *mod)
2251 {
2252 int ret;
2253
2254 ret = event_init(call);
2255 if (ret < 0)
2256 return ret;
2257
2258 list_add(&call->list, &ftrace_events);
2259 call->mod = mod;
2260
2261 return 0;
2262 }
2263
2264 static char *enum_replace(char *ptr, struct trace_enum_map *map, int len)
2265 {
2266 int rlen;
2267 int elen;
2268
2269 /* Find the length of the enum value as a string */
2270 elen = snprintf(ptr, 0, "%ld", map->enum_value);
2271 /* Make sure there's enough room to replace the string with the value */
2272 if (len < elen)
2273 return NULL;
2274
2275 snprintf(ptr, elen + 1, "%ld", map->enum_value);
2276
2277 /* Get the rest of the string of ptr */
2278 rlen = strlen(ptr + len);
2279 memmove(ptr + elen, ptr + len, rlen);
2280 /* Make sure we end the new string */
2281 ptr[elen + rlen] = 0;
2282
2283 return ptr + elen;
2284 }
2285
2286 static void update_event_printk(struct trace_event_call *call,
2287 struct trace_enum_map *map)
2288 {
2289 char *ptr;
2290 int quote = 0;
2291 int len = strlen(map->enum_string);
2292
2293 for (ptr = call->print_fmt; *ptr; ptr++) {
2294 if (*ptr == '\\') {
2295 ptr++;
2296 /* paranoid */
2297 if (!*ptr)
2298 break;
2299 continue;
2300 }
2301 if (*ptr == '"') {
2302 quote ^= 1;
2303 continue;
2304 }
2305 if (quote)
2306 continue;
2307 if (isdigit(*ptr)) {
2308 /* skip numbers */
2309 do {
2310 ptr++;
2311 /* Check for alpha chars like ULL */
2312 } while (isalnum(*ptr));
2313 if (!*ptr)
2314 break;
2315 /*
2316 * A number must have some kind of delimiter after
2317 * it, and we can ignore that too.
2318 */
2319 continue;
2320 }
2321 if (isalpha(*ptr) || *ptr == '_') {
2322 if (strncmp(map->enum_string, ptr, len) == 0 &&
2323 !isalnum(ptr[len]) && ptr[len] != '_') {
2324 ptr = enum_replace(ptr, map, len);
2325 /* Hmm, enum string smaller than value */
2326 if (WARN_ON_ONCE(!ptr))
2327 return;
2328 /*
2329 * No need to decrement here, as enum_replace()
2330 * returns the pointer to the character passed
2331 * the enum, and two enums can not be placed
2332 * back to back without something in between.
2333 * We can skip that something in between.
2334 */
2335 continue;
2336 }
2337 skip_more:
2338 do {
2339 ptr++;
2340 } while (isalnum(*ptr) || *ptr == '_');
2341 if (!*ptr)
2342 break;
2343 /*
2344 * If what comes after this variable is a '.' or
2345 * '->' then we can continue to ignore that string.
2346 */
2347 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2348 ptr += *ptr == '.' ? 1 : 2;
2349 if (!*ptr)
2350 break;
2351 goto skip_more;
2352 }
2353 /*
2354 * Once again, we can skip the delimiter that came
2355 * after the string.
2356 */
2357 continue;
2358 }
2359 }
2360 }
2361
2362 void trace_event_enum_update(struct trace_enum_map **map, int len)
2363 {
2364 struct trace_event_call *call, *p;
2365 const char *last_system = NULL;
2366 int last_i;
2367 int i;
2368
2369 down_write(&trace_event_sem);
2370 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2371 /* events are usually grouped together with systems */
2372 if (!last_system || call->class->system != last_system) {
2373 last_i = 0;
2374 last_system = call->class->system;
2375 }
2376
2377 for (i = last_i; i < len; i++) {
2378 if (call->class->system == map[i]->system) {
2379 /* Save the first system if need be */
2380 if (!last_i)
2381 last_i = i;
2382 update_event_printk(call, map[i]);
2383 }
2384 }
2385 }
2386 up_write(&trace_event_sem);
2387 }
2388
2389 static struct trace_event_file *
2390 trace_create_new_event(struct trace_event_call *call,
2391 struct trace_array *tr)
2392 {
2393 struct trace_event_file *file;
2394
2395 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2396 if (!file)
2397 return NULL;
2398
2399 file->event_call = call;
2400 file->tr = tr;
2401 atomic_set(&file->sm_ref, 0);
2402 atomic_set(&file->tm_ref, 0);
2403 INIT_LIST_HEAD(&file->triggers);
2404 list_add(&file->list, &tr->events);
2405
2406 return file;
2407 }
2408
2409 /* Add an event to a trace directory */
2410 static int
2411 __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2412 {
2413 struct trace_event_file *file;
2414
2415 file = trace_create_new_event(call, tr);
2416 if (!file)
2417 return -ENOMEM;
2418
2419 return event_create_dir(tr->event_dir, file);
2420 }
2421
2422 /*
2423 * Just create a decriptor for early init. A descriptor is required
2424 * for enabling events at boot. We want to enable events before
2425 * the filesystem is initialized.
2426 */
2427 static __init int
2428 __trace_early_add_new_event(struct trace_event_call *call,
2429 struct trace_array *tr)
2430 {
2431 struct trace_event_file *file;
2432
2433 file = trace_create_new_event(call, tr);
2434 if (!file)
2435 return -ENOMEM;
2436
2437 return 0;
2438 }
2439
2440 struct ftrace_module_file_ops;
2441 static void __add_event_to_tracers(struct trace_event_call *call);
2442
2443 /* Add an additional event_call dynamically */
2444 int trace_add_event_call(struct trace_event_call *call)
2445 {
2446 int ret;
2447 mutex_lock(&trace_types_lock);
2448 mutex_lock(&event_mutex);
2449
2450 ret = __register_event(call, NULL);
2451 if (ret >= 0)
2452 __add_event_to_tracers(call);
2453
2454 mutex_unlock(&event_mutex);
2455 mutex_unlock(&trace_types_lock);
2456 return ret;
2457 }
2458
2459 /*
2460 * Must be called under locking of trace_types_lock, event_mutex and
2461 * trace_event_sem.
2462 */
2463 static void __trace_remove_event_call(struct trace_event_call *call)
2464 {
2465 event_remove(call);
2466 trace_destroy_fields(call);
2467 free_event_filter(call->filter);
2468 call->filter = NULL;
2469 }
2470
2471 static int probe_remove_event_call(struct trace_event_call *call)
2472 {
2473 struct trace_array *tr;
2474 struct trace_event_file *file;
2475
2476 #ifdef CONFIG_PERF_EVENTS
2477 if (call->perf_refcount)
2478 return -EBUSY;
2479 #endif
2480 do_for_each_event_file(tr, file) {
2481 if (file->event_call != call)
2482 continue;
2483 /*
2484 * We can't rely on ftrace_event_enable_disable(enable => 0)
2485 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2486 * TRACE_REG_UNREGISTER.
2487 */
2488 if (file->flags & EVENT_FILE_FL_ENABLED)
2489 return -EBUSY;
2490 /*
2491 * The do_for_each_event_file_safe() is
2492 * a double loop. After finding the call for this
2493 * trace_array, we use break to jump to the next
2494 * trace_array.
2495 */
2496 break;
2497 } while_for_each_event_file();
2498
2499 __trace_remove_event_call(call);
2500
2501 return 0;
2502 }
2503
2504 /* Remove an event_call */
2505 int trace_remove_event_call(struct trace_event_call *call)
2506 {
2507 int ret;
2508
2509 mutex_lock(&trace_types_lock);
2510 mutex_lock(&event_mutex);
2511 down_write(&trace_event_sem);
2512 ret = probe_remove_event_call(call);
2513 up_write(&trace_event_sem);
2514 mutex_unlock(&event_mutex);
2515 mutex_unlock(&trace_types_lock);
2516
2517 return ret;
2518 }
2519
2520 #define for_each_event(event, start, end) \
2521 for (event = start; \
2522 (unsigned long)event < (unsigned long)end; \
2523 event++)
2524
2525 #ifdef CONFIG_MODULES
2526
2527 static void trace_module_add_events(struct module *mod)
2528 {
2529 struct trace_event_call **call, **start, **end;
2530
2531 if (!mod->num_trace_events)
2532 return;
2533
2534 /* Don't add infrastructure for mods without tracepoints */
2535 if (trace_module_has_bad_taint(mod)) {
2536 pr_err("%s: module has bad taint, not creating trace events\n",
2537 mod->name);
2538 return;
2539 }
2540
2541 start = mod->trace_events;
2542 end = mod->trace_events + mod->num_trace_events;
2543
2544 for_each_event(call, start, end) {
2545 __register_event(*call, mod);
2546 __add_event_to_tracers(*call);
2547 }
2548 }
2549
2550 static void trace_module_remove_events(struct module *mod)
2551 {
2552 struct trace_event_call *call, *p;
2553 bool clear_trace = false;
2554
2555 down_write(&trace_event_sem);
2556 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2557 if (call->mod == mod) {
2558 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
2559 clear_trace = true;
2560 __trace_remove_event_call(call);
2561 }
2562 }
2563 up_write(&trace_event_sem);
2564
2565 /*
2566 * It is safest to reset the ring buffer if the module being unloaded
2567 * registered any events that were used. The only worry is if
2568 * a new module gets loaded, and takes on the same id as the events
2569 * of this module. When printing out the buffer, traced events left
2570 * over from this module may be passed to the new module events and
2571 * unexpected results may occur.
2572 */
2573 if (clear_trace)
2574 tracing_reset_all_online_cpus();
2575 }
2576
2577 static int trace_module_notify(struct notifier_block *self,
2578 unsigned long val, void *data)
2579 {
2580 struct module *mod = data;
2581
2582 mutex_lock(&trace_types_lock);
2583 mutex_lock(&event_mutex);
2584 switch (val) {
2585 case MODULE_STATE_COMING:
2586 trace_module_add_events(mod);
2587 break;
2588 case MODULE_STATE_GOING:
2589 trace_module_remove_events(mod);
2590 break;
2591 }
2592 mutex_unlock(&event_mutex);
2593 mutex_unlock(&trace_types_lock);
2594
2595 return 0;
2596 }
2597
2598 static struct notifier_block trace_module_nb = {
2599 .notifier_call = trace_module_notify,
2600 .priority = 1, /* higher than trace.c module notify */
2601 };
2602 #endif /* CONFIG_MODULES */
2603
2604 /* Create a new event directory structure for a trace directory. */
2605 static void
2606 __trace_add_event_dirs(struct trace_array *tr)
2607 {
2608 struct trace_event_call *call;
2609 int ret;
2610
2611 list_for_each_entry(call, &ftrace_events, list) {
2612 ret = __trace_add_new_event(call, tr);
2613 if (ret < 0)
2614 pr_warn("Could not create directory for event %s\n",
2615 trace_event_name(call));
2616 }
2617 }
2618
2619 struct trace_event_file *
2620 find_event_file(struct trace_array *tr, const char *system, const char *event)
2621 {
2622 struct trace_event_file *file;
2623 struct trace_event_call *call;
2624 const char *name;
2625
2626 list_for_each_entry(file, &tr->events, list) {
2627
2628 call = file->event_call;
2629 name = trace_event_name(call);
2630
2631 if (!name || !call->class || !call->class->reg)
2632 continue;
2633
2634 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2635 continue;
2636
2637 if (strcmp(event, name) == 0 &&
2638 strcmp(system, call->class->system) == 0)
2639 return file;
2640 }
2641 return NULL;
2642 }
2643
2644 #ifdef CONFIG_DYNAMIC_FTRACE
2645
2646 /* Avoid typos */
2647 #define ENABLE_EVENT_STR "enable_event"
2648 #define DISABLE_EVENT_STR "disable_event"
2649
2650 struct event_probe_data {
2651 struct trace_event_file *file;
2652 unsigned long count;
2653 int ref;
2654 bool enable;
2655 };
2656
2657 static void
2658 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2659 {
2660 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2661 struct event_probe_data *data = *pdata;
2662
2663 if (!data)
2664 return;
2665
2666 if (data->enable)
2667 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2668 else
2669 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2670 }
2671
2672 static void
2673 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2674 {
2675 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2676 struct event_probe_data *data = *pdata;
2677
2678 if (!data)
2679 return;
2680
2681 if (!data->count)
2682 return;
2683
2684 /* Skip if the event is in a state we want to switch to */
2685 if (data->enable == !(data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
2686 return;
2687
2688 if (data->count != -1)
2689 (data->count)--;
2690
2691 event_enable_probe(ip, parent_ip, _data);
2692 }
2693
2694 static int
2695 event_enable_print(struct seq_file *m, unsigned long ip,
2696 struct ftrace_probe_ops *ops, void *_data)
2697 {
2698 struct event_probe_data *data = _data;
2699
2700 seq_printf(m, "%ps:", (void *)ip);
2701
2702 seq_printf(m, "%s:%s:%s",
2703 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2704 data->file->event_call->class->system,
2705 trace_event_name(data->file->event_call));
2706
2707 if (data->count == -1)
2708 seq_puts(m, ":unlimited\n");
2709 else
2710 seq_printf(m, ":count=%ld\n", data->count);
2711
2712 return 0;
2713 }
2714
2715 static int
2716 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
2717 void **_data)
2718 {
2719 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2720 struct event_probe_data *data = *pdata;
2721
2722 data->ref++;
2723 return 0;
2724 }
2725
2726 static void
2727 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
2728 void **_data)
2729 {
2730 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2731 struct event_probe_data *data = *pdata;
2732
2733 if (WARN_ON_ONCE(data->ref <= 0))
2734 return;
2735
2736 data->ref--;
2737 if (!data->ref) {
2738 /* Remove the SOFT_MODE flag */
2739 __ftrace_event_enable_disable(data->file, 0, 1);
2740 module_put(data->file->event_call->mod);
2741 kfree(data);
2742 }
2743 *pdata = NULL;
2744 }
2745
2746 static struct ftrace_probe_ops event_enable_probe_ops = {
2747 .func = event_enable_probe,
2748 .print = event_enable_print,
2749 .init = event_enable_init,
2750 .free = event_enable_free,
2751 };
2752
2753 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2754 .func = event_enable_count_probe,
2755 .print = event_enable_print,
2756 .init = event_enable_init,
2757 .free = event_enable_free,
2758 };
2759
2760 static struct ftrace_probe_ops event_disable_probe_ops = {
2761 .func = event_enable_probe,
2762 .print = event_enable_print,
2763 .init = event_enable_init,
2764 .free = event_enable_free,
2765 };
2766
2767 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2768 .func = event_enable_count_probe,
2769 .print = event_enable_print,
2770 .init = event_enable_init,
2771 .free = event_enable_free,
2772 };
2773
2774 static int
2775 event_enable_func(struct ftrace_hash *hash,
2776 char *glob, char *cmd, char *param, int enabled)
2777 {
2778 struct trace_array *tr = top_trace_array();
2779 struct trace_event_file *file;
2780 struct ftrace_probe_ops *ops;
2781 struct event_probe_data *data;
2782 const char *system;
2783 const char *event;
2784 char *number;
2785 bool enable;
2786 int ret;
2787
2788 if (!tr)
2789 return -ENODEV;
2790
2791 /* hash funcs only work with set_ftrace_filter */
2792 if (!enabled || !param)
2793 return -EINVAL;
2794
2795 system = strsep(&param, ":");
2796 if (!param)
2797 return -EINVAL;
2798
2799 event = strsep(&param, ":");
2800
2801 mutex_lock(&event_mutex);
2802
2803 ret = -EINVAL;
2804 file = find_event_file(tr, system, event);
2805 if (!file)
2806 goto out;
2807
2808 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2809
2810 if (enable)
2811 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2812 else
2813 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2814
2815 if (glob[0] == '!') {
2816 unregister_ftrace_function_probe_func(glob+1, ops);
2817 ret = 0;
2818 goto out;
2819 }
2820
2821 ret = -ENOMEM;
2822 data = kzalloc(sizeof(*data), GFP_KERNEL);
2823 if (!data)
2824 goto out;
2825
2826 data->enable = enable;
2827 data->count = -1;
2828 data->file = file;
2829
2830 if (!param)
2831 goto out_reg;
2832
2833 number = strsep(&param, ":");
2834
2835 ret = -EINVAL;
2836 if (!strlen(number))
2837 goto out_free;
2838
2839 /*
2840 * We use the callback data field (which is a pointer)
2841 * as our counter.
2842 */
2843 ret = kstrtoul(number, 0, &data->count);
2844 if (ret)
2845 goto out_free;
2846
2847 out_reg:
2848 /* Don't let event modules unload while probe registered */
2849 ret = try_module_get(file->event_call->mod);
2850 if (!ret) {
2851 ret = -EBUSY;
2852 goto out_free;
2853 }
2854
2855 ret = __ftrace_event_enable_disable(file, 1, 1);
2856 if (ret < 0)
2857 goto out_put;
2858 ret = register_ftrace_function_probe(glob, ops, data);
2859 /*
2860 * The above returns on success the # of functions enabled,
2861 * but if it didn't find any functions it returns zero.
2862 * Consider no functions a failure too.
2863 */
2864 if (!ret) {
2865 ret = -ENOENT;
2866 goto out_disable;
2867 } else if (ret < 0)
2868 goto out_disable;
2869 /* Just return zero, not the number of enabled functions */
2870 ret = 0;
2871 out:
2872 mutex_unlock(&event_mutex);
2873 return ret;
2874
2875 out_disable:
2876 __ftrace_event_enable_disable(file, 0, 1);
2877 out_put:
2878 module_put(file->event_call->mod);
2879 out_free:
2880 kfree(data);
2881 goto out;
2882 }
2883
2884 static struct ftrace_func_command event_enable_cmd = {
2885 .name = ENABLE_EVENT_STR,
2886 .func = event_enable_func,
2887 };
2888
2889 static struct ftrace_func_command event_disable_cmd = {
2890 .name = DISABLE_EVENT_STR,
2891 .func = event_enable_func,
2892 };
2893
2894 static __init int register_event_cmds(void)
2895 {
2896 int ret;
2897
2898 ret = register_ftrace_command(&event_enable_cmd);
2899 if (WARN_ON(ret < 0))
2900 return ret;
2901 ret = register_ftrace_command(&event_disable_cmd);
2902 if (WARN_ON(ret < 0))
2903 unregister_ftrace_command(&event_enable_cmd);
2904 return ret;
2905 }
2906 #else
2907 static inline int register_event_cmds(void) { return 0; }
2908 #endif /* CONFIG_DYNAMIC_FTRACE */
2909
2910 /*
2911 * The top level array has already had its trace_event_file
2912 * descriptors created in order to allow for early events to
2913 * be recorded. This function is called after the tracefs has been
2914 * initialized, and we now have to create the files associated
2915 * to the events.
2916 */
2917 static __init void
2918 __trace_early_add_event_dirs(struct trace_array *tr)
2919 {
2920 struct trace_event_file *file;
2921 int ret;
2922
2923
2924 list_for_each_entry(file, &tr->events, list) {
2925 ret = event_create_dir(tr->event_dir, file);
2926 if (ret < 0)
2927 pr_warn("Could not create directory for event %s\n",
2928 trace_event_name(file->event_call));
2929 }
2930 }
2931
2932 /*
2933 * For early boot up, the top trace array requires to have
2934 * a list of events that can be enabled. This must be done before
2935 * the filesystem is set up in order to allow events to be traced
2936 * early.
2937 */
2938 static __init void
2939 __trace_early_add_events(struct trace_array *tr)
2940 {
2941 struct trace_event_call *call;
2942 int ret;
2943
2944 list_for_each_entry(call, &ftrace_events, list) {
2945 /* Early boot up should not have any modules loaded */
2946 if (WARN_ON_ONCE(call->mod))
2947 continue;
2948
2949 ret = __trace_early_add_new_event(call, tr);
2950 if (ret < 0)
2951 pr_warn("Could not create early event %s\n",
2952 trace_event_name(call));
2953 }
2954 }
2955
2956 /* Remove the event directory structure for a trace directory. */
2957 static void
2958 __trace_remove_event_dirs(struct trace_array *tr)
2959 {
2960 struct trace_event_file *file, *next;
2961
2962 list_for_each_entry_safe(file, next, &tr->events, list)
2963 remove_event_file_dir(file);
2964 }
2965
2966 static void __add_event_to_tracers(struct trace_event_call *call)
2967 {
2968 struct trace_array *tr;
2969
2970 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2971 __trace_add_new_event(call, tr);
2972 }
2973
2974 extern struct trace_event_call *__start_ftrace_events[];
2975 extern struct trace_event_call *__stop_ftrace_events[];
2976
2977 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2978
2979 static __init int setup_trace_event(char *str)
2980 {
2981 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2982 ring_buffer_expanded = true;
2983 tracing_selftest_disabled = true;
2984
2985 return 1;
2986 }
2987 __setup("trace_event=", setup_trace_event);
2988
2989 /* Expects to have event_mutex held when called */
2990 static int
2991 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2992 {
2993 struct dentry *d_events;
2994 struct dentry *entry;
2995
2996 entry = tracefs_create_file("set_event", 0644, parent,
2997 tr, &ftrace_set_event_fops);
2998 if (!entry) {
2999 pr_warn("Could not create tracefs 'set_event' entry\n");
3000 return -ENOMEM;
3001 }
3002
3003 d_events = tracefs_create_dir("events", parent);
3004 if (!d_events) {
3005 pr_warn("Could not create tracefs 'events' directory\n");
3006 return -ENOMEM;
3007 }
3008
3009 entry = tracefs_create_file("set_event_pid", 0644, parent,
3010 tr, &ftrace_set_event_pid_fops);
3011
3012 /* ring buffer internal formats */
3013 trace_create_file("header_page", 0444, d_events,
3014 ring_buffer_print_page_header,
3015 &ftrace_show_header_fops);
3016
3017 trace_create_file("header_event", 0444, d_events,
3018 ring_buffer_print_entry_header,
3019 &ftrace_show_header_fops);
3020
3021 trace_create_file("enable", 0644, d_events,
3022 tr, &ftrace_tr_enable_fops);
3023
3024 tr->event_dir = d_events;
3025
3026 return 0;
3027 }
3028
3029 /**
3030 * event_trace_add_tracer - add a instance of a trace_array to events
3031 * @parent: The parent dentry to place the files/directories for events in
3032 * @tr: The trace array associated with these events
3033 *
3034 * When a new instance is created, it needs to set up its events
3035 * directory, as well as other files associated with events. It also
3036 * creates the event hierachry in the @parent/events directory.
3037 *
3038 * Returns 0 on success.
3039 */
3040 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
3041 {
3042 int ret;
3043
3044 mutex_lock(&event_mutex);
3045
3046 ret = create_event_toplevel_files(parent, tr);
3047 if (ret)
3048 goto out_unlock;
3049
3050 down_write(&trace_event_sem);
3051 __trace_add_event_dirs(tr);
3052 up_write(&trace_event_sem);
3053
3054 out_unlock:
3055 mutex_unlock(&event_mutex);
3056
3057 return ret;
3058 }
3059
3060 /*
3061 * The top trace array already had its file descriptors created.
3062 * Now the files themselves need to be created.
3063 */
3064 static __init int
3065 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
3066 {
3067 int ret;
3068
3069 mutex_lock(&event_mutex);
3070
3071 ret = create_event_toplevel_files(parent, tr);
3072 if (ret)
3073 goto out_unlock;
3074
3075 down_write(&trace_event_sem);
3076 __trace_early_add_event_dirs(tr);
3077 up_write(&trace_event_sem);
3078
3079 out_unlock:
3080 mutex_unlock(&event_mutex);
3081
3082 return ret;
3083 }
3084
3085 int event_trace_del_tracer(struct trace_array *tr)
3086 {
3087 mutex_lock(&event_mutex);
3088
3089 /* Disable any event triggers and associated soft-disabled events */
3090 clear_event_triggers(tr);
3091
3092 /* Clear the pid list */
3093 __ftrace_clear_event_pids(tr);
3094
3095 /* Disable any running events */
3096 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3097
3098 /* Access to events are within rcu_read_lock_sched() */
3099 synchronize_sched();
3100
3101 down_write(&trace_event_sem);
3102 __trace_remove_event_dirs(tr);
3103 tracefs_remove_recursive(tr->event_dir);
3104 up_write(&trace_event_sem);
3105
3106 tr->event_dir = NULL;
3107
3108 mutex_unlock(&event_mutex);
3109
3110 return 0;
3111 }
3112
3113 static __init int event_trace_memsetup(void)
3114 {
3115 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3116 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3117 return 0;
3118 }
3119
3120 static __init void
3121 early_enable_events(struct trace_array *tr, bool disable_first)
3122 {
3123 char *buf = bootup_event_buf;
3124 char *token;
3125 int ret;
3126
3127 while (true) {
3128 token = strsep(&buf, ",");
3129
3130 if (!token)
3131 break;
3132
3133 if (*token) {
3134 /* Restarting syscalls requires that we stop them first */
3135 if (disable_first)
3136 ftrace_set_clr_event(tr, token, 0);
3137
3138 ret = ftrace_set_clr_event(tr, token, 1);
3139 if (ret)
3140 pr_warn("Failed to enable trace event: %s\n", token);
3141 }
3142
3143 /* Put back the comma to allow this to be called again */
3144 if (buf)
3145 *(buf - 1) = ',';
3146 }
3147 }
3148
3149 static __init int event_trace_enable(void)
3150 {
3151 struct trace_array *tr = top_trace_array();
3152 struct trace_event_call **iter, *call;
3153 int ret;
3154
3155 if (!tr)
3156 return -ENODEV;
3157
3158 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3159
3160 call = *iter;
3161 ret = event_init(call);
3162 if (!ret)
3163 list_add(&call->list, &ftrace_events);
3164 }
3165
3166 /*
3167 * We need the top trace array to have a working set of trace
3168 * points at early init, before the debug files and directories
3169 * are created. Create the file entries now, and attach them
3170 * to the actual file dentries later.
3171 */
3172 __trace_early_add_events(tr);
3173
3174 early_enable_events(tr, false);
3175
3176 trace_printk_start_comm();
3177
3178 register_event_cmds();
3179
3180 register_trigger_cmds();
3181
3182 return 0;
3183 }
3184
3185 /*
3186 * event_trace_enable() is called from trace_event_init() first to
3187 * initialize events and perhaps start any events that are on the
3188 * command line. Unfortunately, there are some events that will not
3189 * start this early, like the system call tracepoints that need
3190 * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
3191 * is called before pid 1 starts, and this flag is never set, making
3192 * the syscall tracepoint never get reached, but the event is enabled
3193 * regardless (and not doing anything).
3194 */
3195 static __init int event_trace_enable_again(void)
3196 {
3197 struct trace_array *tr;
3198
3199 tr = top_trace_array();
3200 if (!tr)
3201 return -ENODEV;
3202
3203 early_enable_events(tr, true);
3204
3205 return 0;
3206 }
3207
3208 early_initcall(event_trace_enable_again);
3209
3210 static __init int event_trace_init(void)
3211 {
3212 struct trace_array *tr;
3213 struct dentry *d_tracer;
3214 struct dentry *entry;
3215 int ret;
3216
3217 tr = top_trace_array();
3218 if (!tr)
3219 return -ENODEV;
3220
3221 d_tracer = tracing_init_dentry();
3222 if (IS_ERR(d_tracer))
3223 return 0;
3224
3225 entry = tracefs_create_file("available_events", 0444, d_tracer,
3226 tr, &ftrace_avail_fops);
3227 if (!entry)
3228 pr_warn("Could not create tracefs 'available_events' entry\n");
3229
3230 if (trace_define_generic_fields())
3231 pr_warn("tracing: Failed to allocated generic fields");
3232
3233 if (trace_define_common_fields())
3234 pr_warn("tracing: Failed to allocate common fields");
3235
3236 ret = early_event_add_tracer(d_tracer, tr);
3237 if (ret)
3238 return ret;
3239
3240 #ifdef CONFIG_MODULES
3241 ret = register_module_notifier(&trace_module_nb);
3242 if (ret)
3243 pr_warn("Failed to register trace events module notifier\n");
3244 #endif
3245 return 0;
3246 }
3247
3248 void __init trace_event_init(void)
3249 {
3250 event_trace_memsetup();
3251 init_ftrace_syscalls();
3252 event_trace_enable();
3253 }
3254
3255 fs_initcall(event_trace_init);
3256
3257 #ifdef CONFIG_FTRACE_STARTUP_TEST
3258
3259 static DEFINE_SPINLOCK(test_spinlock);
3260 static DEFINE_SPINLOCK(test_spinlock_irq);
3261 static DEFINE_MUTEX(test_mutex);
3262
3263 static __init void test_work(struct work_struct *dummy)
3264 {
3265 spin_lock(&test_spinlock);
3266 spin_lock_irq(&test_spinlock_irq);
3267 udelay(1);
3268 spin_unlock_irq(&test_spinlock_irq);
3269 spin_unlock(&test_spinlock);
3270
3271 mutex_lock(&test_mutex);
3272 msleep(1);
3273 mutex_unlock(&test_mutex);
3274 }
3275
3276 static __init int event_test_thread(void *unused)
3277 {
3278 void *test_malloc;
3279
3280 test_malloc = kmalloc(1234, GFP_KERNEL);
3281 if (!test_malloc)
3282 pr_info("failed to kmalloc\n");
3283
3284 schedule_on_each_cpu(test_work);
3285
3286 kfree(test_malloc);
3287
3288 set_current_state(TASK_INTERRUPTIBLE);
3289 while (!kthread_should_stop()) {
3290 schedule();
3291 set_current_state(TASK_INTERRUPTIBLE);
3292 }
3293 __set_current_state(TASK_RUNNING);
3294
3295 return 0;
3296 }
3297
3298 /*
3299 * Do various things that may trigger events.
3300 */
3301 static __init void event_test_stuff(void)
3302 {
3303 struct task_struct *test_thread;
3304
3305 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3306 msleep(1);
3307 kthread_stop(test_thread);
3308 }
3309
3310 /*
3311 * For every trace event defined, we will test each trace point separately,
3312 * and then by groups, and finally all trace points.
3313 */
3314 static __init void event_trace_self_tests(void)
3315 {
3316 struct trace_subsystem_dir *dir;
3317 struct trace_event_file *file;
3318 struct trace_event_call *call;
3319 struct event_subsystem *system;
3320 struct trace_array *tr;
3321 int ret;
3322
3323 tr = top_trace_array();
3324 if (!tr)
3325 return;
3326
3327 pr_info("Running tests on trace events:\n");
3328
3329 list_for_each_entry(file, &tr->events, list) {
3330
3331 call = file->event_call;
3332
3333 /* Only test those that have a probe */
3334 if (!call->class || !call->class->probe)
3335 continue;
3336
3337 /*
3338 * Testing syscall events here is pretty useless, but
3339 * we still do it if configured. But this is time consuming.
3340 * What we really need is a user thread to perform the
3341 * syscalls as we test.
3342 */
3343 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3344 if (call->class->system &&
3345 strcmp(call->class->system, "syscalls") == 0)
3346 continue;
3347 #endif
3348
3349 pr_info("Testing event %s: ", trace_event_name(call));
3350
3351 /*
3352 * If an event is already enabled, someone is using
3353 * it and the self test should not be on.
3354 */
3355 if (file->flags & EVENT_FILE_FL_ENABLED) {
3356 pr_warn("Enabled event during self test!\n");
3357 WARN_ON_ONCE(1);
3358 continue;
3359 }
3360
3361 ftrace_event_enable_disable(file, 1);
3362 event_test_stuff();
3363 ftrace_event_enable_disable(file, 0);
3364
3365 pr_cont("OK\n");
3366 }
3367
3368 /* Now test at the sub system level */
3369
3370 pr_info("Running tests on trace event systems:\n");
3371
3372 list_for_each_entry(dir, &tr->systems, list) {
3373
3374 system = dir->subsystem;
3375
3376 /* the ftrace system is special, skip it */
3377 if (strcmp(system->name, "ftrace") == 0)
3378 continue;
3379
3380 pr_info("Testing event system %s: ", system->name);
3381
3382 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3383 if (WARN_ON_ONCE(ret)) {
3384 pr_warn("error enabling system %s\n",
3385 system->name);
3386 continue;
3387 }
3388
3389 event_test_stuff();
3390
3391 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3392 if (WARN_ON_ONCE(ret)) {
3393 pr_warn("error disabling system %s\n",
3394 system->name);
3395 continue;
3396 }
3397
3398 pr_cont("OK\n");
3399 }
3400
3401 /* Test with all events enabled */
3402
3403 pr_info("Running tests on all trace events:\n");
3404 pr_info("Testing all events: ");
3405
3406 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3407 if (WARN_ON_ONCE(ret)) {
3408 pr_warn("error enabling all events\n");
3409 return;
3410 }
3411
3412 event_test_stuff();
3413
3414 /* reset sysname */
3415 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3416 if (WARN_ON_ONCE(ret)) {
3417 pr_warn("error disabling all events\n");
3418 return;
3419 }
3420
3421 pr_cont("OK\n");
3422 }
3423
3424 #ifdef CONFIG_FUNCTION_TRACER
3425
3426 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3427
3428 static struct trace_event_file event_trace_file __initdata;
3429
3430 static void __init
3431 function_test_events_call(unsigned long ip, unsigned long parent_ip,
3432 struct ftrace_ops *op, struct pt_regs *pt_regs)
3433 {
3434 struct ring_buffer_event *event;
3435 struct ring_buffer *buffer;
3436 struct ftrace_entry *entry;
3437 unsigned long flags;
3438 long disabled;
3439 int cpu;
3440 int pc;
3441
3442 pc = preempt_count();
3443 preempt_disable_notrace();
3444 cpu = raw_smp_processor_id();
3445 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3446
3447 if (disabled != 1)
3448 goto out;
3449
3450 local_save_flags(flags);
3451
3452 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
3453 TRACE_FN, sizeof(*entry),
3454 flags, pc);
3455 if (!event)
3456 goto out;
3457 entry = ring_buffer_event_data(event);
3458 entry->ip = ip;
3459 entry->parent_ip = parent_ip;
3460
3461 event_trigger_unlock_commit(&event_trace_file, buffer, event,
3462 entry, flags, pc);
3463 out:
3464 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3465 preempt_enable_notrace();
3466 }
3467
3468 static struct ftrace_ops trace_ops __initdata =
3469 {
3470 .func = function_test_events_call,
3471 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
3472 };
3473
3474 static __init void event_trace_self_test_with_function(void)
3475 {
3476 int ret;
3477
3478 event_trace_file.tr = top_trace_array();
3479 if (WARN_ON(!event_trace_file.tr))
3480 return;
3481
3482 ret = register_ftrace_function(&trace_ops);
3483 if (WARN_ON(ret < 0)) {
3484 pr_info("Failed to enable function tracer for event tests\n");
3485 return;
3486 }
3487 pr_info("Running tests again, along with the function tracer\n");
3488 event_trace_self_tests();
3489 unregister_ftrace_function(&trace_ops);
3490 }
3491 #else
3492 static __init void event_trace_self_test_with_function(void)
3493 {
3494 }
3495 #endif
3496
3497 static __init int event_trace_self_tests_init(void)
3498 {
3499 if (!tracing_selftest_disabled) {
3500 event_trace_self_tests();
3501 event_trace_self_test_with_function();
3502 }
3503
3504 return 0;
3505 }
3506
3507 late_initcall(event_trace_self_tests_init);
3508
3509 #endif
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