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mm/slab: sanity-check page type when looking up cache
[linux/fpc-iii.git] / kernel / trace / trace_events.c
blob0ce3db67f5569dda5550ce06f98a9cb0e62a96e5
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * event tracer
4 *
5 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
6 *
7 * - Added format output of fields of the trace point.
8 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
9 *
10 */
11
12 #define pr_fmt(fmt) fmt
13
14 #include <linux/workqueue.h>
15 #include <linux/spinlock.h>
16 #include <linux/kthread.h>
17 #include <linux/tracefs.h>
18 #include <linux/uaccess.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_raw(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 /*
266 * If CONFIG_PREEMPT is enabled, then the tracepoint itself disables
267 * preemption (adding one to the preempt_count). Since we are
268 * interested in the preempt_count at the time the tracepoint was
269 * hit, we need to subtract one to offset the increment.
270 */
271 if (IS_ENABLED(CONFIG_PREEMPT))
272 fbuffer->pc--;
273 fbuffer->trace_file = trace_file;
274
275 fbuffer->event =
276 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
277 event_call->event.type, len,
278 fbuffer->flags, fbuffer->pc);
279 if (!fbuffer->event)
280 return NULL;
281
282 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
283 return fbuffer->entry;
284 }
285 EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
286
287 int trace_event_reg(struct trace_event_call *call,
288 enum trace_reg type, void *data)
289 {
290 struct trace_event_file *file = data;
291
292 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
293 switch (type) {
294 case TRACE_REG_REGISTER:
295 return tracepoint_probe_register(call->tp,
296 call->class->probe,
297 file);
298 case TRACE_REG_UNREGISTER:
299 tracepoint_probe_unregister(call->tp,
300 call->class->probe,
301 file);
302 return 0;
303
304 #ifdef CONFIG_PERF_EVENTS
305 case TRACE_REG_PERF_REGISTER:
306 return tracepoint_probe_register(call->tp,
307 call->class->perf_probe,
308 call);
309 case TRACE_REG_PERF_UNREGISTER:
310 tracepoint_probe_unregister(call->tp,
311 call->class->perf_probe,
312 call);
313 return 0;
314 case TRACE_REG_PERF_OPEN:
315 case TRACE_REG_PERF_CLOSE:
316 case TRACE_REG_PERF_ADD:
317 case TRACE_REG_PERF_DEL:
318 return 0;
319 #endif
320 }
321 return 0;
322 }
323 EXPORT_SYMBOL_GPL(trace_event_reg);
324
325 void trace_event_enable_cmd_record(bool enable)
326 {
327 struct trace_event_file *file;
328 struct trace_array *tr;
329
330 mutex_lock(&event_mutex);
331 do_for_each_event_file(tr, file) {
332
333 if (!(file->flags & EVENT_FILE_FL_ENABLED))
334 continue;
335
336 if (enable) {
337 tracing_start_cmdline_record();
338 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
339 } else {
340 tracing_stop_cmdline_record();
341 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
342 }
343 } while_for_each_event_file();
344 mutex_unlock(&event_mutex);
345 }
346
347 void trace_event_enable_tgid_record(bool enable)
348 {
349 struct trace_event_file *file;
350 struct trace_array *tr;
351
352 mutex_lock(&event_mutex);
353 do_for_each_event_file(tr, file) {
354 if (!(file->flags & EVENT_FILE_FL_ENABLED))
355 continue;
356
357 if (enable) {
358 tracing_start_tgid_record();
359 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
360 } else {
361 tracing_stop_tgid_record();
362 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
363 &file->flags);
364 }
365 } while_for_each_event_file();
366 mutex_unlock(&event_mutex);
367 }
368
369 static int __ftrace_event_enable_disable(struct trace_event_file *file,
370 int enable, int soft_disable)
371 {
372 struct trace_event_call *call = file->event_call;
373 struct trace_array *tr = file->tr;
374 unsigned long file_flags = file->flags;
375 int ret = 0;
376 int disable;
377
378 switch (enable) {
379 case 0:
380 /*
381 * When soft_disable is set and enable is cleared, the sm_ref
382 * reference counter is decremented. If it reaches 0, we want
383 * to clear the SOFT_DISABLED flag but leave the event in the
384 * state that it was. That is, if the event was enabled and
385 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
386 * is set we do not want the event to be enabled before we
387 * clear the bit.
388 *
389 * When soft_disable is not set but the SOFT_MODE flag is,
390 * we do nothing. Do not disable the tracepoint, otherwise
391 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
392 */
393 if (soft_disable) {
394 if (atomic_dec_return(&file->sm_ref) > 0)
395 break;
396 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
397 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
398 } else
399 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
400
401 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
402 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
403 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
404 tracing_stop_cmdline_record();
405 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
406 }
407
408 if (file->flags & EVENT_FILE_FL_RECORDED_TGID) {
409 tracing_stop_tgid_record();
410 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
411 }
412
413 call->class->reg(call, TRACE_REG_UNREGISTER, file);
414 }
415 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
416 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
417 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
418 else
419 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
420 break;
421 case 1:
422 /*
423 * When soft_disable is set and enable is set, we want to
424 * register the tracepoint for the event, but leave the event
425 * as is. That means, if the event was already enabled, we do
426 * nothing (but set SOFT_MODE). If the event is disabled, we
427 * set SOFT_DISABLED before enabling the event tracepoint, so
428 * it still seems to be disabled.
429 */
430 if (!soft_disable)
431 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
432 else {
433 if (atomic_inc_return(&file->sm_ref) > 1)
434 break;
435 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
436 }
437
438 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
439 bool cmd = false, tgid = false;
440
441 /* Keep the event disabled, when going to SOFT_MODE. */
442 if (soft_disable)
443 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
444
445 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
446 cmd = true;
447 tracing_start_cmdline_record();
448 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
449 }
450
451 if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
452 tgid = true;
453 tracing_start_tgid_record();
454 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
455 }
456
457 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
458 if (ret) {
459 if (cmd)
460 tracing_stop_cmdline_record();
461 if (tgid)
462 tracing_stop_tgid_record();
463 pr_info("event trace: Could not enable event "
464 "%s\n", trace_event_name(call));
465 break;
466 }
467 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
468
469 /* WAS_ENABLED gets set but never cleared. */
470 set_bit(EVENT_FILE_FL_WAS_ENABLED_BIT, &file->flags);
471 }
472 break;
473 }
474
475 /* Enable or disable use of trace_buffered_event */
476 if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) !=
477 (file->flags & EVENT_FILE_FL_SOFT_DISABLED)) {
478 if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
479 trace_buffered_event_enable();
480 else
481 trace_buffered_event_disable();
482 }
483
484 return ret;
485 }
486
487 int trace_event_enable_disable(struct trace_event_file *file,
488 int enable, int soft_disable)
489 {
490 return __ftrace_event_enable_disable(file, enable, soft_disable);
491 }
492
493 static int ftrace_event_enable_disable(struct trace_event_file *file,
494 int enable)
495 {
496 return __ftrace_event_enable_disable(file, enable, 0);
497 }
498
499 static void ftrace_clear_events(struct trace_array *tr)
500 {
501 struct trace_event_file *file;
502
503 mutex_lock(&event_mutex);
504 list_for_each_entry(file, &tr->events, list) {
505 ftrace_event_enable_disable(file, 0);
506 }
507 mutex_unlock(&event_mutex);
508 }
509
510 static void
511 event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
512 {
513 struct trace_pid_list *pid_list;
514 struct trace_array *tr = data;
515
516 pid_list = rcu_dereference_raw(tr->filtered_pids);
517 trace_filter_add_remove_task(pid_list, NULL, task);
518 }
519
520 static void
521 event_filter_pid_sched_process_fork(void *data,
522 struct task_struct *self,
523 struct task_struct *task)
524 {
525 struct trace_pid_list *pid_list;
526 struct trace_array *tr = data;
527
528 pid_list = rcu_dereference_sched(tr->filtered_pids);
529 trace_filter_add_remove_task(pid_list, self, task);
530 }
531
532 void trace_event_follow_fork(struct trace_array *tr, bool enable)
533 {
534 if (enable) {
535 register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
536 tr, INT_MIN);
537 register_trace_prio_sched_process_exit(event_filter_pid_sched_process_exit,
538 tr, INT_MAX);
539 } else {
540 unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
541 tr);
542 unregister_trace_sched_process_exit(event_filter_pid_sched_process_exit,
543 tr);
544 }
545 }
546
547 static void
548 event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
549 struct task_struct *prev, struct task_struct *next)
550 {
551 struct trace_array *tr = data;
552 struct trace_pid_list *pid_list;
553
554 pid_list = rcu_dereference_sched(tr->filtered_pids);
555
556 this_cpu_write(tr->trace_buffer.data->ignore_pid,
557 trace_ignore_this_task(pid_list, prev) &&
558 trace_ignore_this_task(pid_list, next));
559 }
560
561 static void
562 event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
563 struct task_struct *prev, struct task_struct *next)
564 {
565 struct trace_array *tr = data;
566 struct trace_pid_list *pid_list;
567
568 pid_list = rcu_dereference_sched(tr->filtered_pids);
569
570 this_cpu_write(tr->trace_buffer.data->ignore_pid,
571 trace_ignore_this_task(pid_list, next));
572 }
573
574 static void
575 event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
576 {
577 struct trace_array *tr = data;
578 struct trace_pid_list *pid_list;
579
580 /* Nothing to do if we are already tracing */
581 if (!this_cpu_read(tr->trace_buffer.data->ignore_pid))
582 return;
583
584 pid_list = rcu_dereference_sched(tr->filtered_pids);
585
586 this_cpu_write(tr->trace_buffer.data->ignore_pid,
587 trace_ignore_this_task(pid_list, task));
588 }
589
590 static void
591 event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
592 {
593 struct trace_array *tr = data;
594 struct trace_pid_list *pid_list;
595
596 /* Nothing to do if we are not tracing */
597 if (this_cpu_read(tr->trace_buffer.data->ignore_pid))
598 return;
599
600 pid_list = rcu_dereference_sched(tr->filtered_pids);
601
602 /* Set tracing if current is enabled */
603 this_cpu_write(tr->trace_buffer.data->ignore_pid,
604 trace_ignore_this_task(pid_list, current));
605 }
606
607 static void __ftrace_clear_event_pids(struct trace_array *tr)
608 {
609 struct trace_pid_list *pid_list;
610 struct trace_event_file *file;
611 int cpu;
612
613 pid_list = rcu_dereference_protected(tr->filtered_pids,
614 lockdep_is_held(&event_mutex));
615 if (!pid_list)
616 return;
617
618 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
619 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
620
621 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
622 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
623
624 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
625 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
626
627 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
628 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
629
630 list_for_each_entry(file, &tr->events, list) {
631 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
632 }
633
634 for_each_possible_cpu(cpu)
635 per_cpu_ptr(tr->trace_buffer.data, cpu)->ignore_pid = false;
636
637 rcu_assign_pointer(tr->filtered_pids, NULL);
638
639 /* Wait till all users are no longer using pid filtering */
640 tracepoint_synchronize_unregister();
641
642 trace_free_pid_list(pid_list);
643 }
644
645 static void ftrace_clear_event_pids(struct trace_array *tr)
646 {
647 mutex_lock(&event_mutex);
648 __ftrace_clear_event_pids(tr);
649 mutex_unlock(&event_mutex);
650 }
651
652 static void __put_system(struct event_subsystem *system)
653 {
654 struct event_filter *filter = system->filter;
655
656 WARN_ON_ONCE(system_refcount(system) == 0);
657 if (system_refcount_dec(system))
658 return;
659
660 list_del(&system->list);
661
662 if (filter) {
663 kfree(filter->filter_string);
664 kfree(filter);
665 }
666 kfree_const(system->name);
667 kfree(system);
668 }
669
670 static void __get_system(struct event_subsystem *system)
671 {
672 WARN_ON_ONCE(system_refcount(system) == 0);
673 system_refcount_inc(system);
674 }
675
676 static void __get_system_dir(struct trace_subsystem_dir *dir)
677 {
678 WARN_ON_ONCE(dir->ref_count == 0);
679 dir->ref_count++;
680 __get_system(dir->subsystem);
681 }
682
683 static void __put_system_dir(struct trace_subsystem_dir *dir)
684 {
685 WARN_ON_ONCE(dir->ref_count == 0);
686 /* If the subsystem is about to be freed, the dir must be too */
687 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
688
689 __put_system(dir->subsystem);
690 if (!--dir->ref_count)
691 kfree(dir);
692 }
693
694 static void put_system(struct trace_subsystem_dir *dir)
695 {
696 mutex_lock(&event_mutex);
697 __put_system_dir(dir);
698 mutex_unlock(&event_mutex);
699 }
700
701 static void remove_subsystem(struct trace_subsystem_dir *dir)
702 {
703 if (!dir)
704 return;
705
706 if (!--dir->nr_events) {
707 tracefs_remove_recursive(dir->entry);
708 list_del(&dir->list);
709 __put_system_dir(dir);
710 }
711 }
712
713 static void remove_event_file_dir(struct trace_event_file *file)
714 {
715 struct dentry *dir = file->dir;
716 struct dentry *child;
717
718 if (dir) {
719 spin_lock(&dir->d_lock); /* probably unneeded */
720 list_for_each_entry(child, &dir->d_subdirs, d_child) {
721 if (d_really_is_positive(child)) /* probably unneeded */
722 d_inode(child)->i_private = NULL;
723 }
724 spin_unlock(&dir->d_lock);
725
726 tracefs_remove_recursive(dir);
727 }
728
729 list_del(&file->list);
730 remove_subsystem(file->system);
731 free_event_filter(file->filter);
732 kmem_cache_free(file_cachep, file);
733 }
734
735 /*
736 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
737 */
738 static int
739 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
740 const char *sub, const char *event, int set)
741 {
742 struct trace_event_file *file;
743 struct trace_event_call *call;
744 const char *name;
745 int ret = -EINVAL;
746 int eret = 0;
747
748 list_for_each_entry(file, &tr->events, list) {
749
750 call = file->event_call;
751 name = trace_event_name(call);
752
753 if (!name || !call->class || !call->class->reg)
754 continue;
755
756 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
757 continue;
758
759 if (match &&
760 strcmp(match, name) != 0 &&
761 strcmp(match, call->class->system) != 0)
762 continue;
763
764 if (sub && strcmp(sub, call->class->system) != 0)
765 continue;
766
767 if (event && strcmp(event, name) != 0)
768 continue;
769
770 ret = ftrace_event_enable_disable(file, set);
771
772 /*
773 * Save the first error and return that. Some events
774 * may still have been enabled, but let the user
775 * know that something went wrong.
776 */
777 if (ret && !eret)
778 eret = ret;
779
780 ret = eret;
781 }
782
783 return ret;
784 }
785
786 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
787 const char *sub, const char *event, int set)
788 {
789 int ret;
790
791 mutex_lock(&event_mutex);
792 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
793 mutex_unlock(&event_mutex);
794
795 return ret;
796 }
797
798 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
799 {
800 char *event = NULL, *sub = NULL, *match;
801 int ret;
802
803 /*
804 * The buf format can be <subsystem>:<event-name>
805 * *:<event-name> means any event by that name.
806 * :<event-name> is the same.
807 *
808 * <subsystem>:* means all events in that subsystem
809 * <subsystem>: means the same.
810 *
811 * <name> (no ':') means all events in a subsystem with
812 * the name <name> or any event that matches <name>
813 */
814
815 match = strsep(&buf, ":");
816 if (buf) {
817 sub = match;
818 event = buf;
819 match = NULL;
820
821 if (!strlen(sub) || strcmp(sub, "*") == 0)
822 sub = NULL;
823 if (!strlen(event) || strcmp(event, "*") == 0)
824 event = NULL;
825 }
826
827 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
828
829 /* Put back the colon to allow this to be called again */
830 if (buf)
831 *(buf - 1) = ':';
832
833 return ret;
834 }
835 EXPORT_SYMBOL_GPL(ftrace_set_clr_event);
836
837 /**
838 * trace_set_clr_event - enable or disable an event
839 * @system: system name to match (NULL for any system)
840 * @event: event name to match (NULL for all events, within system)
841 * @set: 1 to enable, 0 to disable
842 *
843 * This is a way for other parts of the kernel to enable or disable
844 * event recording.
845 *
846 * Returns 0 on success, -EINVAL if the parameters do not match any
847 * registered events.
848 */
849 int trace_set_clr_event(const char *system, const char *event, int set)
850 {
851 struct trace_array *tr = top_trace_array();
852
853 if (!tr)
854 return -ENODEV;
855
856 return __ftrace_set_clr_event(tr, NULL, system, event, set);
857 }
858 EXPORT_SYMBOL_GPL(trace_set_clr_event);
859
860 /* 128 should be much more than enough */
861 #define EVENT_BUF_SIZE 127
862
863 static ssize_t
864 ftrace_event_write(struct file *file, const char __user *ubuf,
865 size_t cnt, loff_t *ppos)
866 {
867 struct trace_parser parser;
868 struct seq_file *m = file->private_data;
869 struct trace_array *tr = m->private;
870 ssize_t read, ret;
871
872 if (!cnt)
873 return 0;
874
875 ret = tracing_update_buffers();
876 if (ret < 0)
877 return ret;
878
879 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
880 return -ENOMEM;
881
882 read = trace_get_user(&parser, ubuf, cnt, ppos);
883
884 if (read >= 0 && trace_parser_loaded((&parser))) {
885 int set = 1;
886
887 if (*parser.buffer == '!')
888 set = 0;
889
890 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
891 if (ret)
892 goto out_put;
893 }
894
895 ret = read;
896
897 out_put:
898 trace_parser_put(&parser);
899
900 return ret;
901 }
902
903 static void *
904 t_next(struct seq_file *m, void *v, loff_t *pos)
905 {
906 struct trace_event_file *file = v;
907 struct trace_event_call *call;
908 struct trace_array *tr = m->private;
909
910 (*pos)++;
911
912 list_for_each_entry_continue(file, &tr->events, list) {
913 call = file->event_call;
914 /*
915 * The ftrace subsystem is for showing formats only.
916 * They can not be enabled or disabled via the event files.
917 */
918 if (call->class && call->class->reg &&
919 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
920 return file;
921 }
922
923 return NULL;
924 }
925
926 static void *t_start(struct seq_file *m, loff_t *pos)
927 {
928 struct trace_event_file *file;
929 struct trace_array *tr = m->private;
930 loff_t l;
931
932 mutex_lock(&event_mutex);
933
934 file = list_entry(&tr->events, struct trace_event_file, list);
935 for (l = 0; l <= *pos; ) {
936 file = t_next(m, file, &l);
937 if (!file)
938 break;
939 }
940 return file;
941 }
942
943 static void *
944 s_next(struct seq_file *m, void *v, loff_t *pos)
945 {
946 struct trace_event_file *file = v;
947 struct trace_array *tr = m->private;
948
949 (*pos)++;
950
951 list_for_each_entry_continue(file, &tr->events, list) {
952 if (file->flags & EVENT_FILE_FL_ENABLED)
953 return file;
954 }
955
956 return NULL;
957 }
958
959 static void *s_start(struct seq_file *m, loff_t *pos)
960 {
961 struct trace_event_file *file;
962 struct trace_array *tr = m->private;
963 loff_t l;
964
965 mutex_lock(&event_mutex);
966
967 file = list_entry(&tr->events, struct trace_event_file, list);
968 for (l = 0; l <= *pos; ) {
969 file = s_next(m, file, &l);
970 if (!file)
971 break;
972 }
973 return file;
974 }
975
976 static int t_show(struct seq_file *m, void *v)
977 {
978 struct trace_event_file *file = v;
979 struct trace_event_call *call = file->event_call;
980
981 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
982 seq_printf(m, "%s:", call->class->system);
983 seq_printf(m, "%s\n", trace_event_name(call));
984
985 return 0;
986 }
987
988 static void t_stop(struct seq_file *m, void *p)
989 {
990 mutex_unlock(&event_mutex);
991 }
992
993 static void *
994 p_next(struct seq_file *m, void *v, loff_t *pos)
995 {
996 struct trace_array *tr = m->private;
997 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
998
999 return trace_pid_next(pid_list, v, pos);
1000 }
1001
1002 static void *p_start(struct seq_file *m, loff_t *pos)
1003 __acquires(RCU)
1004 {
1005 struct trace_pid_list *pid_list;
1006 struct trace_array *tr = m->private;
1007
1008 /*
1009 * Grab the mutex, to keep calls to p_next() having the same
1010 * tr->filtered_pids as p_start() has.
1011 * If we just passed the tr->filtered_pids around, then RCU would
1012 * have been enough, but doing that makes things more complex.
1013 */
1014 mutex_lock(&event_mutex);
1015 rcu_read_lock_sched();
1016
1017 pid_list = rcu_dereference_sched(tr->filtered_pids);
1018
1019 if (!pid_list)
1020 return NULL;
1021
1022 return trace_pid_start(pid_list, pos);
1023 }
1024
1025 static void p_stop(struct seq_file *m, void *p)
1026 __releases(RCU)
1027 {
1028 rcu_read_unlock_sched();
1029 mutex_unlock(&event_mutex);
1030 }
1031
1032 static ssize_t
1033 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1034 loff_t *ppos)
1035 {
1036 struct trace_event_file *file;
1037 unsigned long flags;
1038 char buf[4] = "0";
1039
1040 mutex_lock(&event_mutex);
1041 file = event_file_data(filp);
1042 if (likely(file))
1043 flags = file->flags;
1044 mutex_unlock(&event_mutex);
1045
1046 if (!file)
1047 return -ENODEV;
1048
1049 if (flags & EVENT_FILE_FL_ENABLED &&
1050 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1051 strcpy(buf, "1");
1052
1053 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1054 flags & EVENT_FILE_FL_SOFT_MODE)
1055 strcat(buf, "*");
1056
1057 strcat(buf, "\n");
1058
1059 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1060 }
1061
1062 static ssize_t
1063 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1064 loff_t *ppos)
1065 {
1066 struct trace_event_file *file;
1067 unsigned long val;
1068 int ret;
1069
1070 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1071 if (ret)
1072 return ret;
1073
1074 ret = tracing_update_buffers();
1075 if (ret < 0)
1076 return ret;
1077
1078 switch (val) {
1079 case 0:
1080 case 1:
1081 ret = -ENODEV;
1082 mutex_lock(&event_mutex);
1083 file = event_file_data(filp);
1084 if (likely(file))
1085 ret = ftrace_event_enable_disable(file, val);
1086 mutex_unlock(&event_mutex);
1087 break;
1088
1089 default:
1090 return -EINVAL;
1091 }
1092
1093 *ppos += cnt;
1094
1095 return ret ? ret : cnt;
1096 }
1097
1098 static ssize_t
1099 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1100 loff_t *ppos)
1101 {
1102 const char set_to_char[4] = { '?', '0', '1', 'X' };
1103 struct trace_subsystem_dir *dir = filp->private_data;
1104 struct event_subsystem *system = dir->subsystem;
1105 struct trace_event_call *call;
1106 struct trace_event_file *file;
1107 struct trace_array *tr = dir->tr;
1108 char buf[2];
1109 int set = 0;
1110 int ret;
1111
1112 mutex_lock(&event_mutex);
1113 list_for_each_entry(file, &tr->events, list) {
1114 call = file->event_call;
1115 if (!trace_event_name(call) || !call->class || !call->class->reg)
1116 continue;
1117
1118 if (system && strcmp(call->class->system, system->name) != 0)
1119 continue;
1120
1121 /*
1122 * We need to find out if all the events are set
1123 * or if all events or cleared, or if we have
1124 * a mixture.
1125 */
1126 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1127
1128 /*
1129 * If we have a mixture, no need to look further.
1130 */
1131 if (set == 3)
1132 break;
1133 }
1134 mutex_unlock(&event_mutex);
1135
1136 buf[0] = set_to_char[set];
1137 buf[1] = '\n';
1138
1139 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1140
1141 return ret;
1142 }
1143
1144 static ssize_t
1145 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1146 loff_t *ppos)
1147 {
1148 struct trace_subsystem_dir *dir = filp->private_data;
1149 struct event_subsystem *system = dir->subsystem;
1150 const char *name = NULL;
1151 unsigned long val;
1152 ssize_t ret;
1153
1154 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1155 if (ret)
1156 return ret;
1157
1158 ret = tracing_update_buffers();
1159 if (ret < 0)
1160 return ret;
1161
1162 if (val != 0 && val != 1)
1163 return -EINVAL;
1164
1165 /*
1166 * Opening of "enable" adds a ref count to system,
1167 * so the name is safe to use.
1168 */
1169 if (system)
1170 name = system->name;
1171
1172 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1173 if (ret)
1174 goto out;
1175
1176 ret = cnt;
1177
1178 out:
1179 *ppos += cnt;
1180
1181 return ret;
1182 }
1183
1184 enum {
1185 FORMAT_HEADER = 1,
1186 FORMAT_FIELD_SEPERATOR = 2,
1187 FORMAT_PRINTFMT = 3,
1188 };
1189
1190 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1191 {
1192 struct trace_event_call *call = event_file_data(m->private);
1193 struct list_head *common_head = &ftrace_common_fields;
1194 struct list_head *head = trace_get_fields(call);
1195 struct list_head *node = v;
1196
1197 (*pos)++;
1198
1199 switch ((unsigned long)v) {
1200 case FORMAT_HEADER:
1201 node = common_head;
1202 break;
1203
1204 case FORMAT_FIELD_SEPERATOR:
1205 node = head;
1206 break;
1207
1208 case FORMAT_PRINTFMT:
1209 /* all done */
1210 return NULL;
1211 }
1212
1213 node = node->prev;
1214 if (node == common_head)
1215 return (void *)FORMAT_FIELD_SEPERATOR;
1216 else if (node == head)
1217 return (void *)FORMAT_PRINTFMT;
1218 else
1219 return node;
1220 }
1221
1222 static int f_show(struct seq_file *m, void *v)
1223 {
1224 struct trace_event_call *call = event_file_data(m->private);
1225 struct ftrace_event_field *field;
1226 const char *array_descriptor;
1227
1228 switch ((unsigned long)v) {
1229 case FORMAT_HEADER:
1230 seq_printf(m, "name: %s\n", trace_event_name(call));
1231 seq_printf(m, "ID: %d\n", call->event.type);
1232 seq_puts(m, "format:\n");
1233 return 0;
1234
1235 case FORMAT_FIELD_SEPERATOR:
1236 seq_putc(m, '\n');
1237 return 0;
1238
1239 case FORMAT_PRINTFMT:
1240 seq_printf(m, "\nprint fmt: %s\n",
1241 call->print_fmt);
1242 return 0;
1243 }
1244
1245 field = list_entry(v, struct ftrace_event_field, link);
1246 /*
1247 * Smartly shows the array type(except dynamic array).
1248 * Normal:
1249 * field:TYPE VAR
1250 * If TYPE := TYPE[LEN], it is shown:
1251 * field:TYPE VAR[LEN]
1252 */
1253 array_descriptor = strchr(field->type, '[');
1254
1255 if (str_has_prefix(field->type, "__data_loc"))
1256 array_descriptor = NULL;
1257
1258 if (!array_descriptor)
1259 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1260 field->type, field->name, field->offset,
1261 field->size, !!field->is_signed);
1262 else
1263 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1264 (int)(array_descriptor - field->type),
1265 field->type, field->name,
1266 array_descriptor, field->offset,
1267 field->size, !!field->is_signed);
1268
1269 return 0;
1270 }
1271
1272 static void *f_start(struct seq_file *m, loff_t *pos)
1273 {
1274 void *p = (void *)FORMAT_HEADER;
1275 loff_t l = 0;
1276
1277 /* ->stop() is called even if ->start() fails */
1278 mutex_lock(&event_mutex);
1279 if (!event_file_data(m->private))
1280 return ERR_PTR(-ENODEV);
1281
1282 while (l < *pos && p)
1283 p = f_next(m, p, &l);
1284
1285 return p;
1286 }
1287
1288 static void f_stop(struct seq_file *m, void *p)
1289 {
1290 mutex_unlock(&event_mutex);
1291 }
1292
1293 static const struct seq_operations trace_format_seq_ops = {
1294 .start = f_start,
1295 .next = f_next,
1296 .stop = f_stop,
1297 .show = f_show,
1298 };
1299
1300 static int trace_format_open(struct inode *inode, struct file *file)
1301 {
1302 struct seq_file *m;
1303 int ret;
1304
1305 ret = seq_open(file, &trace_format_seq_ops);
1306 if (ret < 0)
1307 return ret;
1308
1309 m = file->private_data;
1310 m->private = file;
1311
1312 return 0;
1313 }
1314
1315 static ssize_t
1316 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1317 {
1318 int id = (long)event_file_data(filp);
1319 char buf[32];
1320 int len;
1321
1322 if (unlikely(!id))
1323 return -ENODEV;
1324
1325 len = sprintf(buf, "%d\n", id);
1326
1327 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1328 }
1329
1330 static ssize_t
1331 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1332 loff_t *ppos)
1333 {
1334 struct trace_event_file *file;
1335 struct trace_seq *s;
1336 int r = -ENODEV;
1337
1338 if (*ppos)
1339 return 0;
1340
1341 s = kmalloc(sizeof(*s), GFP_KERNEL);
1342
1343 if (!s)
1344 return -ENOMEM;
1345
1346 trace_seq_init(s);
1347
1348 mutex_lock(&event_mutex);
1349 file = event_file_data(filp);
1350 if (file)
1351 print_event_filter(file, s);
1352 mutex_unlock(&event_mutex);
1353
1354 if (file)
1355 r = simple_read_from_buffer(ubuf, cnt, ppos,
1356 s->buffer, trace_seq_used(s));
1357
1358 kfree(s);
1359
1360 return r;
1361 }
1362
1363 static ssize_t
1364 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1365 loff_t *ppos)
1366 {
1367 struct trace_event_file *file;
1368 char *buf;
1369 int err = -ENODEV;
1370
1371 if (cnt >= PAGE_SIZE)
1372 return -EINVAL;
1373
1374 buf = memdup_user_nul(ubuf, cnt);
1375 if (IS_ERR(buf))
1376 return PTR_ERR(buf);
1377
1378 mutex_lock(&event_mutex);
1379 file = event_file_data(filp);
1380 if (file)
1381 err = apply_event_filter(file, buf);
1382 mutex_unlock(&event_mutex);
1383
1384 kfree(buf);
1385 if (err < 0)
1386 return err;
1387
1388 *ppos += cnt;
1389
1390 return cnt;
1391 }
1392
1393 static LIST_HEAD(event_subsystems);
1394
1395 static int subsystem_open(struct inode *inode, struct file *filp)
1396 {
1397 struct event_subsystem *system = NULL;
1398 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1399 struct trace_array *tr;
1400 int ret;
1401
1402 if (tracing_is_disabled())
1403 return -ENODEV;
1404
1405 /* Make sure the system still exists */
1406 mutex_lock(&event_mutex);
1407 mutex_lock(&trace_types_lock);
1408 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1409 list_for_each_entry(dir, &tr->systems, list) {
1410 if (dir == inode->i_private) {
1411 /* Don't open systems with no events */
1412 if (dir->nr_events) {
1413 __get_system_dir(dir);
1414 system = dir->subsystem;
1415 }
1416 goto exit_loop;
1417 }
1418 }
1419 }
1420 exit_loop:
1421 mutex_unlock(&trace_types_lock);
1422 mutex_unlock(&event_mutex);
1423
1424 if (!system)
1425 return -ENODEV;
1426
1427 /* Some versions of gcc think dir can be uninitialized here */
1428 WARN_ON(!dir);
1429
1430 /* Still need to increment the ref count of the system */
1431 if (trace_array_get(tr) < 0) {
1432 put_system(dir);
1433 return -ENODEV;
1434 }
1435
1436 ret = tracing_open_generic(inode, filp);
1437 if (ret < 0) {
1438 trace_array_put(tr);
1439 put_system(dir);
1440 }
1441
1442 return ret;
1443 }
1444
1445 static int system_tr_open(struct inode *inode, struct file *filp)
1446 {
1447 struct trace_subsystem_dir *dir;
1448 struct trace_array *tr = inode->i_private;
1449 int ret;
1450
1451 if (tracing_is_disabled())
1452 return -ENODEV;
1453
1454 if (trace_array_get(tr) < 0)
1455 return -ENODEV;
1456
1457 /* Make a temporary dir that has no system but points to tr */
1458 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1459 if (!dir) {
1460 trace_array_put(tr);
1461 return -ENOMEM;
1462 }
1463
1464 dir->tr = tr;
1465
1466 ret = tracing_open_generic(inode, filp);
1467 if (ret < 0) {
1468 trace_array_put(tr);
1469 kfree(dir);
1470 return ret;
1471 }
1472
1473 filp->private_data = dir;
1474
1475 return 0;
1476 }
1477
1478 static int subsystem_release(struct inode *inode, struct file *file)
1479 {
1480 struct trace_subsystem_dir *dir = file->private_data;
1481
1482 trace_array_put(dir->tr);
1483
1484 /*
1485 * If dir->subsystem is NULL, then this is a temporary
1486 * descriptor that was made for a trace_array to enable
1487 * all subsystems.
1488 */
1489 if (dir->subsystem)
1490 put_system(dir);
1491 else
1492 kfree(dir);
1493
1494 return 0;
1495 }
1496
1497 static ssize_t
1498 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1499 loff_t *ppos)
1500 {
1501 struct trace_subsystem_dir *dir = filp->private_data;
1502 struct event_subsystem *system = dir->subsystem;
1503 struct trace_seq *s;
1504 int r;
1505
1506 if (*ppos)
1507 return 0;
1508
1509 s = kmalloc(sizeof(*s), GFP_KERNEL);
1510 if (!s)
1511 return -ENOMEM;
1512
1513 trace_seq_init(s);
1514
1515 print_subsystem_event_filter(system, s);
1516 r = simple_read_from_buffer(ubuf, cnt, ppos,
1517 s->buffer, trace_seq_used(s));
1518
1519 kfree(s);
1520
1521 return r;
1522 }
1523
1524 static ssize_t
1525 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1526 loff_t *ppos)
1527 {
1528 struct trace_subsystem_dir *dir = filp->private_data;
1529 char *buf;
1530 int err;
1531
1532 if (cnt >= PAGE_SIZE)
1533 return -EINVAL;
1534
1535 buf = memdup_user_nul(ubuf, cnt);
1536 if (IS_ERR(buf))
1537 return PTR_ERR(buf);
1538
1539 err = apply_subsystem_event_filter(dir, buf);
1540 kfree(buf);
1541 if (err < 0)
1542 return err;
1543
1544 *ppos += cnt;
1545
1546 return cnt;
1547 }
1548
1549 static ssize_t
1550 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1551 {
1552 int (*func)(struct trace_seq *s) = filp->private_data;
1553 struct trace_seq *s;
1554 int r;
1555
1556 if (*ppos)
1557 return 0;
1558
1559 s = kmalloc(sizeof(*s), GFP_KERNEL);
1560 if (!s)
1561 return -ENOMEM;
1562
1563 trace_seq_init(s);
1564
1565 func(s);
1566 r = simple_read_from_buffer(ubuf, cnt, ppos,
1567 s->buffer, trace_seq_used(s));
1568
1569 kfree(s);
1570
1571 return r;
1572 }
1573
1574 static void ignore_task_cpu(void *data)
1575 {
1576 struct trace_array *tr = data;
1577 struct trace_pid_list *pid_list;
1578
1579 /*
1580 * This function is called by on_each_cpu() while the
1581 * event_mutex is held.
1582 */
1583 pid_list = rcu_dereference_protected(tr->filtered_pids,
1584 mutex_is_locked(&event_mutex));
1585
1586 this_cpu_write(tr->trace_buffer.data->ignore_pid,
1587 trace_ignore_this_task(pid_list, current));
1588 }
1589
1590 static ssize_t
1591 ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1592 size_t cnt, loff_t *ppos)
1593 {
1594 struct seq_file *m = filp->private_data;
1595 struct trace_array *tr = m->private;
1596 struct trace_pid_list *filtered_pids = NULL;
1597 struct trace_pid_list *pid_list;
1598 struct trace_event_file *file;
1599 ssize_t ret;
1600
1601 if (!cnt)
1602 return 0;
1603
1604 ret = tracing_update_buffers();
1605 if (ret < 0)
1606 return ret;
1607
1608 mutex_lock(&event_mutex);
1609
1610 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1611 lockdep_is_held(&event_mutex));
1612
1613 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
1614 if (ret < 0)
1615 goto out;
1616
1617 rcu_assign_pointer(tr->filtered_pids, pid_list);
1618
1619 list_for_each_entry(file, &tr->events, list) {
1620 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1621 }
1622
1623 if (filtered_pids) {
1624 tracepoint_synchronize_unregister();
1625 trace_free_pid_list(filtered_pids);
1626 } else if (pid_list) {
1627 /*
1628 * Register a probe that is called before all other probes
1629 * to set ignore_pid if next or prev do not match.
1630 * Register a probe this is called after all other probes
1631 * to only keep ignore_pid set if next pid matches.
1632 */
1633 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1634 tr, INT_MAX);
1635 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1636 tr, 0);
1637
1638 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1639 tr, INT_MAX);
1640 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1641 tr, 0);
1642
1643 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1644 tr, INT_MAX);
1645 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1646 tr, 0);
1647
1648 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1649 tr, INT_MAX);
1650 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1651 tr, 0);
1652 }
1653
1654 /*
1655 * Ignoring of pids is done at task switch. But we have to
1656 * check for those tasks that are currently running.
1657 * Always do this in case a pid was appended or removed.
1658 */
1659 on_each_cpu(ignore_task_cpu, tr, 1);
1660
1661 out:
1662 mutex_unlock(&event_mutex);
1663
1664 if (ret > 0)
1665 *ppos += ret;
1666
1667 return ret;
1668 }
1669
1670 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1671 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1672 static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
1673 static int ftrace_event_release(struct inode *inode, struct file *file);
1674
1675 static const struct seq_operations show_event_seq_ops = {
1676 .start = t_start,
1677 .next = t_next,
1678 .show = t_show,
1679 .stop = t_stop,
1680 };
1681
1682 static const struct seq_operations show_set_event_seq_ops = {
1683 .start = s_start,
1684 .next = s_next,
1685 .show = t_show,
1686 .stop = t_stop,
1687 };
1688
1689 static const struct seq_operations show_set_pid_seq_ops = {
1690 .start = p_start,
1691 .next = p_next,
1692 .show = trace_pid_show,
1693 .stop = p_stop,
1694 };
1695
1696 static const struct file_operations ftrace_avail_fops = {
1697 .open = ftrace_event_avail_open,
1698 .read = seq_read,
1699 .llseek = seq_lseek,
1700 .release = seq_release,
1701 };
1702
1703 static const struct file_operations ftrace_set_event_fops = {
1704 .open = ftrace_event_set_open,
1705 .read = seq_read,
1706 .write = ftrace_event_write,
1707 .llseek = seq_lseek,
1708 .release = ftrace_event_release,
1709 };
1710
1711 static const struct file_operations ftrace_set_event_pid_fops = {
1712 .open = ftrace_event_set_pid_open,
1713 .read = seq_read,
1714 .write = ftrace_event_pid_write,
1715 .llseek = seq_lseek,
1716 .release = ftrace_event_release,
1717 };
1718
1719 static const struct file_operations ftrace_enable_fops = {
1720 .open = tracing_open_generic,
1721 .read = event_enable_read,
1722 .write = event_enable_write,
1723 .llseek = default_llseek,
1724 };
1725
1726 static const struct file_operations ftrace_event_format_fops = {
1727 .open = trace_format_open,
1728 .read = seq_read,
1729 .llseek = seq_lseek,
1730 .release = seq_release,
1731 };
1732
1733 static const struct file_operations ftrace_event_id_fops = {
1734 .read = event_id_read,
1735 .llseek = default_llseek,
1736 };
1737
1738 static const struct file_operations ftrace_event_filter_fops = {
1739 .open = tracing_open_generic,
1740 .read = event_filter_read,
1741 .write = event_filter_write,
1742 .llseek = default_llseek,
1743 };
1744
1745 static const struct file_operations ftrace_subsystem_filter_fops = {
1746 .open = subsystem_open,
1747 .read = subsystem_filter_read,
1748 .write = subsystem_filter_write,
1749 .llseek = default_llseek,
1750 .release = subsystem_release,
1751 };
1752
1753 static const struct file_operations ftrace_system_enable_fops = {
1754 .open = subsystem_open,
1755 .read = system_enable_read,
1756 .write = system_enable_write,
1757 .llseek = default_llseek,
1758 .release = subsystem_release,
1759 };
1760
1761 static const struct file_operations ftrace_tr_enable_fops = {
1762 .open = system_tr_open,
1763 .read = system_enable_read,
1764 .write = system_enable_write,
1765 .llseek = default_llseek,
1766 .release = subsystem_release,
1767 };
1768
1769 static const struct file_operations ftrace_show_header_fops = {
1770 .open = tracing_open_generic,
1771 .read = show_header,
1772 .llseek = default_llseek,
1773 };
1774
1775 static int
1776 ftrace_event_open(struct inode *inode, struct file *file,
1777 const struct seq_operations *seq_ops)
1778 {
1779 struct seq_file *m;
1780 int ret;
1781
1782 ret = seq_open(file, seq_ops);
1783 if (ret < 0)
1784 return ret;
1785 m = file->private_data;
1786 /* copy tr over to seq ops */
1787 m->private = inode->i_private;
1788
1789 return ret;
1790 }
1791
1792 static int ftrace_event_release(struct inode *inode, struct file *file)
1793 {
1794 struct trace_array *tr = inode->i_private;
1795
1796 trace_array_put(tr);
1797
1798 return seq_release(inode, file);
1799 }
1800
1801 static int
1802 ftrace_event_avail_open(struct inode *inode, struct file *file)
1803 {
1804 const struct seq_operations *seq_ops = &show_event_seq_ops;
1805
1806 return ftrace_event_open(inode, file, seq_ops);
1807 }
1808
1809 static int
1810 ftrace_event_set_open(struct inode *inode, struct file *file)
1811 {
1812 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1813 struct trace_array *tr = inode->i_private;
1814 int ret;
1815
1816 if (trace_array_get(tr) < 0)
1817 return -ENODEV;
1818
1819 if ((file->f_mode & FMODE_WRITE) &&
1820 (file->f_flags & O_TRUNC))
1821 ftrace_clear_events(tr);
1822
1823 ret = ftrace_event_open(inode, file, seq_ops);
1824 if (ret < 0)
1825 trace_array_put(tr);
1826 return ret;
1827 }
1828
1829 static int
1830 ftrace_event_set_pid_open(struct inode *inode, struct file *file)
1831 {
1832 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
1833 struct trace_array *tr = inode->i_private;
1834 int ret;
1835
1836 if (trace_array_get(tr) < 0)
1837 return -ENODEV;
1838
1839 if ((file->f_mode & FMODE_WRITE) &&
1840 (file->f_flags & O_TRUNC))
1841 ftrace_clear_event_pids(tr);
1842
1843 ret = ftrace_event_open(inode, file, seq_ops);
1844 if (ret < 0)
1845 trace_array_put(tr);
1846 return ret;
1847 }
1848
1849 static struct event_subsystem *
1850 create_new_subsystem(const char *name)
1851 {
1852 struct event_subsystem *system;
1853
1854 /* need to create new entry */
1855 system = kmalloc(sizeof(*system), GFP_KERNEL);
1856 if (!system)
1857 return NULL;
1858
1859 system->ref_count = 1;
1860
1861 /* Only allocate if dynamic (kprobes and modules) */
1862 system->name = kstrdup_const(name, GFP_KERNEL);
1863 if (!system->name)
1864 goto out_free;
1865
1866 system->filter = NULL;
1867
1868 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1869 if (!system->filter)
1870 goto out_free;
1871
1872 list_add(&system->list, &event_subsystems);
1873
1874 return system;
1875
1876 out_free:
1877 kfree_const(system->name);
1878 kfree(system);
1879 return NULL;
1880 }
1881
1882 static struct dentry *
1883 event_subsystem_dir(struct trace_array *tr, const char *name,
1884 struct trace_event_file *file, struct dentry *parent)
1885 {
1886 struct trace_subsystem_dir *dir;
1887 struct event_subsystem *system;
1888 struct dentry *entry;
1889
1890 /* First see if we did not already create this dir */
1891 list_for_each_entry(dir, &tr->systems, list) {
1892 system = dir->subsystem;
1893 if (strcmp(system->name, name) == 0) {
1894 dir->nr_events++;
1895 file->system = dir;
1896 return dir->entry;
1897 }
1898 }
1899
1900 /* Now see if the system itself exists. */
1901 list_for_each_entry(system, &event_subsystems, list) {
1902 if (strcmp(system->name, name) == 0)
1903 break;
1904 }
1905 /* Reset system variable when not found */
1906 if (&system->list == &event_subsystems)
1907 system = NULL;
1908
1909 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1910 if (!dir)
1911 goto out_fail;
1912
1913 if (!system) {
1914 system = create_new_subsystem(name);
1915 if (!system)
1916 goto out_free;
1917 } else
1918 __get_system(system);
1919
1920 dir->entry = tracefs_create_dir(name, parent);
1921 if (!dir->entry) {
1922 pr_warn("Failed to create system directory %s\n", name);
1923 __put_system(system);
1924 goto out_free;
1925 }
1926
1927 dir->tr = tr;
1928 dir->ref_count = 1;
1929 dir->nr_events = 1;
1930 dir->subsystem = system;
1931 file->system = dir;
1932
1933 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
1934 &ftrace_subsystem_filter_fops);
1935 if (!entry) {
1936 kfree(system->filter);
1937 system->filter = NULL;
1938 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
1939 }
1940
1941 trace_create_file("enable", 0644, dir->entry, dir,
1942 &ftrace_system_enable_fops);
1943
1944 list_add(&dir->list, &tr->systems);
1945
1946 return dir->entry;
1947
1948 out_free:
1949 kfree(dir);
1950 out_fail:
1951 /* Only print this message if failed on memory allocation */
1952 if (!dir || !system)
1953 pr_warn("No memory to create event subsystem %s\n", name);
1954 return NULL;
1955 }
1956
1957 static int
1958 event_create_dir(struct dentry *parent, struct trace_event_file *file)
1959 {
1960 struct trace_event_call *call = file->event_call;
1961 struct trace_array *tr = file->tr;
1962 struct list_head *head;
1963 struct dentry *d_events;
1964 const char *name;
1965 int ret;
1966
1967 /*
1968 * If the trace point header did not define TRACE_SYSTEM
1969 * then the system would be called "TRACE_SYSTEM".
1970 */
1971 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1972 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1973 if (!d_events)
1974 return -ENOMEM;
1975 } else
1976 d_events = parent;
1977
1978 name = trace_event_name(call);
1979 file->dir = tracefs_create_dir(name, d_events);
1980 if (!file->dir) {
1981 pr_warn("Could not create tracefs '%s' directory\n", name);
1982 return -1;
1983 }
1984
1985 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1986 trace_create_file("enable", 0644, file->dir, file,
1987 &ftrace_enable_fops);
1988
1989 #ifdef CONFIG_PERF_EVENTS
1990 if (call->event.type && call->class->reg)
1991 trace_create_file("id", 0444, file->dir,
1992 (void *)(long)call->event.type,
1993 &ftrace_event_id_fops);
1994 #endif
1995
1996 /*
1997 * Other events may have the same class. Only update
1998 * the fields if they are not already defined.
1999 */
2000 head = trace_get_fields(call);
2001 if (list_empty(head)) {
2002 ret = call->class->define_fields(call);
2003 if (ret < 0) {
2004 pr_warn("Could not initialize trace point events/%s\n",
2005 name);
2006 return -1;
2007 }
2008 }
2009
2010 /*
2011 * Only event directories that can be enabled should have
2012 * triggers or filters.
2013 */
2014 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
2015 trace_create_file("filter", 0644, file->dir, file,
2016 &ftrace_event_filter_fops);
2017
2018 trace_create_file("trigger", 0644, file->dir, file,
2019 &event_trigger_fops);
2020 }
2021
2022 #ifdef CONFIG_HIST_TRIGGERS
2023 trace_create_file("hist", 0444, file->dir, file,
2024 &event_hist_fops);
2025 #endif
2026 trace_create_file("format", 0444, file->dir, call,
2027 &ftrace_event_format_fops);
2028
2029 return 0;
2030 }
2031
2032 static void remove_event_from_tracers(struct trace_event_call *call)
2033 {
2034 struct trace_event_file *file;
2035 struct trace_array *tr;
2036
2037 do_for_each_event_file_safe(tr, file) {
2038 if (file->event_call != call)
2039 continue;
2040
2041 remove_event_file_dir(file);
2042 /*
2043 * The do_for_each_event_file_safe() is
2044 * a double loop. After finding the call for this
2045 * trace_array, we use break to jump to the next
2046 * trace_array.
2047 */
2048 break;
2049 } while_for_each_event_file();
2050 }
2051
2052 static void event_remove(struct trace_event_call *call)
2053 {
2054 struct trace_array *tr;
2055 struct trace_event_file *file;
2056
2057 do_for_each_event_file(tr, file) {
2058 if (file->event_call != call)
2059 continue;
2060
2061 if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
2062 tr->clear_trace = true;
2063
2064 ftrace_event_enable_disable(file, 0);
2065 /*
2066 * The do_for_each_event_file() is
2067 * a double loop. After finding the call for this
2068 * trace_array, we use break to jump to the next
2069 * trace_array.
2070 */
2071 break;
2072 } while_for_each_event_file();
2073
2074 if (call->event.funcs)
2075 __unregister_trace_event(&call->event);
2076 remove_event_from_tracers(call);
2077 list_del(&call->list);
2078 }
2079
2080 static int event_init(struct trace_event_call *call)
2081 {
2082 int ret = 0;
2083 const char *name;
2084
2085 name = trace_event_name(call);
2086 if (WARN_ON(!name))
2087 return -EINVAL;
2088
2089 if (call->class->raw_init) {
2090 ret = call->class->raw_init(call);
2091 if (ret < 0 && ret != -ENOSYS)
2092 pr_warn("Could not initialize trace events/%s\n", name);
2093 }
2094
2095 return ret;
2096 }
2097
2098 static int
2099 __register_event(struct trace_event_call *call, struct module *mod)
2100 {
2101 int ret;
2102
2103 ret = event_init(call);
2104 if (ret < 0)
2105 return ret;
2106
2107 list_add(&call->list, &ftrace_events);
2108 call->mod = mod;
2109
2110 return 0;
2111 }
2112
2113 static char *eval_replace(char *ptr, struct trace_eval_map *map, int len)
2114 {
2115 int rlen;
2116 int elen;
2117
2118 /* Find the length of the eval value as a string */
2119 elen = snprintf(ptr, 0, "%ld", map->eval_value);
2120 /* Make sure there's enough room to replace the string with the value */
2121 if (len < elen)
2122 return NULL;
2123
2124 snprintf(ptr, elen + 1, "%ld", map->eval_value);
2125
2126 /* Get the rest of the string of ptr */
2127 rlen = strlen(ptr + len);
2128 memmove(ptr + elen, ptr + len, rlen);
2129 /* Make sure we end the new string */
2130 ptr[elen + rlen] = 0;
2131
2132 return ptr + elen;
2133 }
2134
2135 static void update_event_printk(struct trace_event_call *call,
2136 struct trace_eval_map *map)
2137 {
2138 char *ptr;
2139 int quote = 0;
2140 int len = strlen(map->eval_string);
2141
2142 for (ptr = call->print_fmt; *ptr; ptr++) {
2143 if (*ptr == '\\') {
2144 ptr++;
2145 /* paranoid */
2146 if (!*ptr)
2147 break;
2148 continue;
2149 }
2150 if (*ptr == '"') {
2151 quote ^= 1;
2152 continue;
2153 }
2154 if (quote)
2155 continue;
2156 if (isdigit(*ptr)) {
2157 /* skip numbers */
2158 do {
2159 ptr++;
2160 /* Check for alpha chars like ULL */
2161 } while (isalnum(*ptr));
2162 if (!*ptr)
2163 break;
2164 /*
2165 * A number must have some kind of delimiter after
2166 * it, and we can ignore that too.
2167 */
2168 continue;
2169 }
2170 if (isalpha(*ptr) || *ptr == '_') {
2171 if (strncmp(map->eval_string, ptr, len) == 0 &&
2172 !isalnum(ptr[len]) && ptr[len] != '_') {
2173 ptr = eval_replace(ptr, map, len);
2174 /* enum/sizeof string smaller than value */
2175 if (WARN_ON_ONCE(!ptr))
2176 return;
2177 /*
2178 * No need to decrement here, as eval_replace()
2179 * returns the pointer to the character passed
2180 * the eval, and two evals can not be placed
2181 * back to back without something in between.
2182 * We can skip that something in between.
2183 */
2184 continue;
2185 }
2186 skip_more:
2187 do {
2188 ptr++;
2189 } while (isalnum(*ptr) || *ptr == '_');
2190 if (!*ptr)
2191 break;
2192 /*
2193 * If what comes after this variable is a '.' or
2194 * '->' then we can continue to ignore that string.
2195 */
2196 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2197 ptr += *ptr == '.' ? 1 : 2;
2198 if (!*ptr)
2199 break;
2200 goto skip_more;
2201 }
2202 /*
2203 * Once again, we can skip the delimiter that came
2204 * after the string.
2205 */
2206 continue;
2207 }
2208 }
2209 }
2210
2211 void trace_event_eval_update(struct trace_eval_map **map, int len)
2212 {
2213 struct trace_event_call *call, *p;
2214 const char *last_system = NULL;
2215 bool first = false;
2216 int last_i;
2217 int i;
2218
2219 down_write(&trace_event_sem);
2220 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2221 /* events are usually grouped together with systems */
2222 if (!last_system || call->class->system != last_system) {
2223 first = true;
2224 last_i = 0;
2225 last_system = call->class->system;
2226 }
2227
2228 /*
2229 * Since calls are grouped by systems, the likelyhood that the
2230 * next call in the iteration belongs to the same system as the
2231 * previous call is high. As an optimization, we skip seaching
2232 * for a map[] that matches the call's system if the last call
2233 * was from the same system. That's what last_i is for. If the
2234 * call has the same system as the previous call, then last_i
2235 * will be the index of the first map[] that has a matching
2236 * system.
2237 */
2238 for (i = last_i; i < len; i++) {
2239 if (call->class->system == map[i]->system) {
2240 /* Save the first system if need be */
2241 if (first) {
2242 last_i = i;
2243 first = false;
2244 }
2245 update_event_printk(call, map[i]);
2246 }
2247 }
2248 }
2249 up_write(&trace_event_sem);
2250 }
2251
2252 static struct trace_event_file *
2253 trace_create_new_event(struct trace_event_call *call,
2254 struct trace_array *tr)
2255 {
2256 struct trace_event_file *file;
2257
2258 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2259 if (!file)
2260 return NULL;
2261
2262 file->event_call = call;
2263 file->tr = tr;
2264 atomic_set(&file->sm_ref, 0);
2265 atomic_set(&file->tm_ref, 0);
2266 INIT_LIST_HEAD(&file->triggers);
2267 list_add(&file->list, &tr->events);
2268
2269 return file;
2270 }
2271
2272 /* Add an event to a trace directory */
2273 static int
2274 __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2275 {
2276 struct trace_event_file *file;
2277
2278 file = trace_create_new_event(call, tr);
2279 if (!file)
2280 return -ENOMEM;
2281
2282 return event_create_dir(tr->event_dir, file);
2283 }
2284
2285 /*
2286 * Just create a decriptor for early init. A descriptor is required
2287 * for enabling events at boot. We want to enable events before
2288 * the filesystem is initialized.
2289 */
2290 static __init int
2291 __trace_early_add_new_event(struct trace_event_call *call,
2292 struct trace_array *tr)
2293 {
2294 struct trace_event_file *file;
2295
2296 file = trace_create_new_event(call, tr);
2297 if (!file)
2298 return -ENOMEM;
2299
2300 return 0;
2301 }
2302
2303 struct ftrace_module_file_ops;
2304 static void __add_event_to_tracers(struct trace_event_call *call);
2305
2306 /* Add an additional event_call dynamically */
2307 int trace_add_event_call(struct trace_event_call *call)
2308 {
2309 int ret;
2310 lockdep_assert_held(&event_mutex);
2311
2312 mutex_lock(&trace_types_lock);
2313
2314 ret = __register_event(call, NULL);
2315 if (ret >= 0)
2316 __add_event_to_tracers(call);
2317
2318 mutex_unlock(&trace_types_lock);
2319 return ret;
2320 }
2321
2322 /*
2323 * Must be called under locking of trace_types_lock, event_mutex and
2324 * trace_event_sem.
2325 */
2326 static void __trace_remove_event_call(struct trace_event_call *call)
2327 {
2328 event_remove(call);
2329 trace_destroy_fields(call);
2330 free_event_filter(call->filter);
2331 call->filter = NULL;
2332 }
2333
2334 static int probe_remove_event_call(struct trace_event_call *call)
2335 {
2336 struct trace_array *tr;
2337 struct trace_event_file *file;
2338
2339 #ifdef CONFIG_PERF_EVENTS
2340 if (call->perf_refcount)
2341 return -EBUSY;
2342 #endif
2343 do_for_each_event_file(tr, file) {
2344 if (file->event_call != call)
2345 continue;
2346 /*
2347 * We can't rely on ftrace_event_enable_disable(enable => 0)
2348 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2349 * TRACE_REG_UNREGISTER.
2350 */
2351 if (file->flags & EVENT_FILE_FL_ENABLED)
2352 return -EBUSY;
2353 /*
2354 * The do_for_each_event_file_safe() is
2355 * a double loop. After finding the call for this
2356 * trace_array, we use break to jump to the next
2357 * trace_array.
2358 */
2359 break;
2360 } while_for_each_event_file();
2361
2362 __trace_remove_event_call(call);
2363
2364 return 0;
2365 }
2366
2367 /* Remove an event_call */
2368 int trace_remove_event_call(struct trace_event_call *call)
2369 {
2370 int ret;
2371
2372 lockdep_assert_held(&event_mutex);
2373
2374 mutex_lock(&trace_types_lock);
2375 down_write(&trace_event_sem);
2376 ret = probe_remove_event_call(call);
2377 up_write(&trace_event_sem);
2378 mutex_unlock(&trace_types_lock);
2379
2380 return ret;
2381 }
2382
2383 #define for_each_event(event, start, end) \
2384 for (event = start; \
2385 (unsigned long)event < (unsigned long)end; \
2386 event++)
2387
2388 #ifdef CONFIG_MODULES
2389
2390 static void trace_module_add_events(struct module *mod)
2391 {
2392 struct trace_event_call **call, **start, **end;
2393
2394 if (!mod->num_trace_events)
2395 return;
2396
2397 /* Don't add infrastructure for mods without tracepoints */
2398 if (trace_module_has_bad_taint(mod)) {
2399 pr_err("%s: module has bad taint, not creating trace events\n",
2400 mod->name);
2401 return;
2402 }
2403
2404 start = mod->trace_events;
2405 end = mod->trace_events + mod->num_trace_events;
2406
2407 for_each_event(call, start, end) {
2408 __register_event(*call, mod);
2409 __add_event_to_tracers(*call);
2410 }
2411 }
2412
2413 static void trace_module_remove_events(struct module *mod)
2414 {
2415 struct trace_event_call *call, *p;
2416
2417 down_write(&trace_event_sem);
2418 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2419 if (call->mod == mod)
2420 __trace_remove_event_call(call);
2421 }
2422 up_write(&trace_event_sem);
2423
2424 /*
2425 * It is safest to reset the ring buffer if the module being unloaded
2426 * registered any events that were used. The only worry is if
2427 * a new module gets loaded, and takes on the same id as the events
2428 * of this module. When printing out the buffer, traced events left
2429 * over from this module may be passed to the new module events and
2430 * unexpected results may occur.
2431 */
2432 tracing_reset_all_online_cpus();
2433 }
2434
2435 static int trace_module_notify(struct notifier_block *self,
2436 unsigned long val, void *data)
2437 {
2438 struct module *mod = data;
2439
2440 mutex_lock(&event_mutex);
2441 mutex_lock(&trace_types_lock);
2442 switch (val) {
2443 case MODULE_STATE_COMING:
2444 trace_module_add_events(mod);
2445 break;
2446 case MODULE_STATE_GOING:
2447 trace_module_remove_events(mod);
2448 break;
2449 }
2450 mutex_unlock(&trace_types_lock);
2451 mutex_unlock(&event_mutex);
2452
2453 return 0;
2454 }
2455
2456 static struct notifier_block trace_module_nb = {
2457 .notifier_call = trace_module_notify,
2458 .priority = 1, /* higher than trace.c module notify */
2459 };
2460 #endif /* CONFIG_MODULES */
2461
2462 /* Create a new event directory structure for a trace directory. */
2463 static void
2464 __trace_add_event_dirs(struct trace_array *tr)
2465 {
2466 struct trace_event_call *call;
2467 int ret;
2468
2469 list_for_each_entry(call, &ftrace_events, list) {
2470 ret = __trace_add_new_event(call, tr);
2471 if (ret < 0)
2472 pr_warn("Could not create directory for event %s\n",
2473 trace_event_name(call));
2474 }
2475 }
2476
2477 /* Returns any file that matches the system and event */
2478 struct trace_event_file *
2479 __find_event_file(struct trace_array *tr, const char *system, const char *event)
2480 {
2481 struct trace_event_file *file;
2482 struct trace_event_call *call;
2483 const char *name;
2484
2485 list_for_each_entry(file, &tr->events, list) {
2486
2487 call = file->event_call;
2488 name = trace_event_name(call);
2489
2490 if (!name || !call->class)
2491 continue;
2492
2493 if (strcmp(event, name) == 0 &&
2494 strcmp(system, call->class->system) == 0)
2495 return file;
2496 }
2497 return NULL;
2498 }
2499
2500 /* Returns valid trace event files that match system and event */
2501 struct trace_event_file *
2502 find_event_file(struct trace_array *tr, const char *system, const char *event)
2503 {
2504 struct trace_event_file *file;
2505
2506 file = __find_event_file(tr, system, event);
2507 if (!file || !file->event_call->class->reg ||
2508 file->event_call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2509 return NULL;
2510
2511 return file;
2512 }
2513
2514 #ifdef CONFIG_DYNAMIC_FTRACE
2515
2516 /* Avoid typos */
2517 #define ENABLE_EVENT_STR "enable_event"
2518 #define DISABLE_EVENT_STR "disable_event"
2519
2520 struct event_probe_data {
2521 struct trace_event_file *file;
2522 unsigned long count;
2523 int ref;
2524 bool enable;
2525 };
2526
2527 static void update_event_probe(struct event_probe_data *data)
2528 {
2529 if (data->enable)
2530 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2531 else
2532 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2533 }
2534
2535 static void
2536 event_enable_probe(unsigned long ip, unsigned long parent_ip,
2537 struct trace_array *tr, struct ftrace_probe_ops *ops,
2538 void *data)
2539 {
2540 struct ftrace_func_mapper *mapper = data;
2541 struct event_probe_data *edata;
2542 void **pdata;
2543
2544 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2545 if (!pdata || !*pdata)
2546 return;
2547
2548 edata = *pdata;
2549 update_event_probe(edata);
2550 }
2551
2552 static void
2553 event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
2554 struct trace_array *tr, struct ftrace_probe_ops *ops,
2555 void *data)
2556 {
2557 struct ftrace_func_mapper *mapper = data;
2558 struct event_probe_data *edata;
2559 void **pdata;
2560
2561 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2562 if (!pdata || !*pdata)
2563 return;
2564
2565 edata = *pdata;
2566
2567 if (!edata->count)
2568 return;
2569
2570 /* Skip if the event is in a state we want to switch to */
2571 if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
2572 return;
2573
2574 if (edata->count != -1)
2575 (edata->count)--;
2576
2577 update_event_probe(edata);
2578 }
2579
2580 static int
2581 event_enable_print(struct seq_file *m, unsigned long ip,
2582 struct ftrace_probe_ops *ops, void *data)
2583 {
2584 struct ftrace_func_mapper *mapper = data;
2585 struct event_probe_data *edata;
2586 void **pdata;
2587
2588 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2589
2590 if (WARN_ON_ONCE(!pdata || !*pdata))
2591 return 0;
2592
2593 edata = *pdata;
2594
2595 seq_printf(m, "%ps:", (void *)ip);
2596
2597 seq_printf(m, "%s:%s:%s",
2598 edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2599 edata->file->event_call->class->system,
2600 trace_event_name(edata->file->event_call));
2601
2602 if (edata->count == -1)
2603 seq_puts(m, ":unlimited\n");
2604 else
2605 seq_printf(m, ":count=%ld\n", edata->count);
2606
2607 return 0;
2608 }
2609
2610 static int
2611 event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
2612 unsigned long ip, void *init_data, void **data)
2613 {
2614 struct ftrace_func_mapper *mapper = *data;
2615 struct event_probe_data *edata = init_data;
2616 int ret;
2617
2618 if (!mapper) {
2619 mapper = allocate_ftrace_func_mapper();
2620 if (!mapper)
2621 return -ENODEV;
2622 *data = mapper;
2623 }
2624
2625 ret = ftrace_func_mapper_add_ip(mapper, ip, edata);
2626 if (ret < 0)
2627 return ret;
2628
2629 edata->ref++;
2630
2631 return 0;
2632 }
2633
2634 static int free_probe_data(void *data)
2635 {
2636 struct event_probe_data *edata = data;
2637
2638 edata->ref--;
2639 if (!edata->ref) {
2640 /* Remove the SOFT_MODE flag */
2641 __ftrace_event_enable_disable(edata->file, 0, 1);
2642 module_put(edata->file->event_call->mod);
2643 kfree(edata);
2644 }
2645 return 0;
2646 }
2647
2648 static void
2649 event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
2650 unsigned long ip, void *data)
2651 {
2652 struct ftrace_func_mapper *mapper = data;
2653 struct event_probe_data *edata;
2654
2655 if (!ip) {
2656 if (!mapper)
2657 return;
2658 free_ftrace_func_mapper(mapper, free_probe_data);
2659 return;
2660 }
2661
2662 edata = ftrace_func_mapper_remove_ip(mapper, ip);
2663
2664 if (WARN_ON_ONCE(!edata))
2665 return;
2666
2667 if (WARN_ON_ONCE(edata->ref <= 0))
2668 return;
2669
2670 free_probe_data(edata);
2671 }
2672
2673 static struct ftrace_probe_ops event_enable_probe_ops = {
2674 .func = event_enable_probe,
2675 .print = event_enable_print,
2676 .init = event_enable_init,
2677 .free = event_enable_free,
2678 };
2679
2680 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2681 .func = event_enable_count_probe,
2682 .print = event_enable_print,
2683 .init = event_enable_init,
2684 .free = event_enable_free,
2685 };
2686
2687 static struct ftrace_probe_ops event_disable_probe_ops = {
2688 .func = event_enable_probe,
2689 .print = event_enable_print,
2690 .init = event_enable_init,
2691 .free = event_enable_free,
2692 };
2693
2694 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2695 .func = event_enable_count_probe,
2696 .print = event_enable_print,
2697 .init = event_enable_init,
2698 .free = event_enable_free,
2699 };
2700
2701 static int
2702 event_enable_func(struct trace_array *tr, struct ftrace_hash *hash,
2703 char *glob, char *cmd, char *param, int enabled)
2704 {
2705 struct trace_event_file *file;
2706 struct ftrace_probe_ops *ops;
2707 struct event_probe_data *data;
2708 const char *system;
2709 const char *event;
2710 char *number;
2711 bool enable;
2712 int ret;
2713
2714 if (!tr)
2715 return -ENODEV;
2716
2717 /* hash funcs only work with set_ftrace_filter */
2718 if (!enabled || !param)
2719 return -EINVAL;
2720
2721 system = strsep(&param, ":");
2722 if (!param)
2723 return -EINVAL;
2724
2725 event = strsep(&param, ":");
2726
2727 mutex_lock(&event_mutex);
2728
2729 ret = -EINVAL;
2730 file = find_event_file(tr, system, event);
2731 if (!file)
2732 goto out;
2733
2734 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2735
2736 if (enable)
2737 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2738 else
2739 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2740
2741 if (glob[0] == '!') {
2742 ret = unregister_ftrace_function_probe_func(glob+1, tr, ops);
2743 goto out;
2744 }
2745
2746 ret = -ENOMEM;
2747
2748 data = kzalloc(sizeof(*data), GFP_KERNEL);
2749 if (!data)
2750 goto out;
2751
2752 data->enable = enable;
2753 data->count = -1;
2754 data->file = file;
2755
2756 if (!param)
2757 goto out_reg;
2758
2759 number = strsep(&param, ":");
2760
2761 ret = -EINVAL;
2762 if (!strlen(number))
2763 goto out_free;
2764
2765 /*
2766 * We use the callback data field (which is a pointer)
2767 * as our counter.
2768 */
2769 ret = kstrtoul(number, 0, &data->count);
2770 if (ret)
2771 goto out_free;
2772
2773 out_reg:
2774 /* Don't let event modules unload while probe registered */
2775 ret = try_module_get(file->event_call->mod);
2776 if (!ret) {
2777 ret = -EBUSY;
2778 goto out_free;
2779 }
2780
2781 ret = __ftrace_event_enable_disable(file, 1, 1);
2782 if (ret < 0)
2783 goto out_put;
2784
2785 ret = register_ftrace_function_probe(glob, tr, ops, data);
2786 /*
2787 * The above returns on success the # of functions enabled,
2788 * but if it didn't find any functions it returns zero.
2789 * Consider no functions a failure too.
2790 */
2791 if (!ret) {
2792 ret = -ENOENT;
2793 goto out_disable;
2794 } else if (ret < 0)
2795 goto out_disable;
2796 /* Just return zero, not the number of enabled functions */
2797 ret = 0;
2798 out:
2799 mutex_unlock(&event_mutex);
2800 return ret;
2801
2802 out_disable:
2803 __ftrace_event_enable_disable(file, 0, 1);
2804 out_put:
2805 module_put(file->event_call->mod);
2806 out_free:
2807 kfree(data);
2808 goto out;
2809 }
2810
2811 static struct ftrace_func_command event_enable_cmd = {
2812 .name = ENABLE_EVENT_STR,
2813 .func = event_enable_func,
2814 };
2815
2816 static struct ftrace_func_command event_disable_cmd = {
2817 .name = DISABLE_EVENT_STR,
2818 .func = event_enable_func,
2819 };
2820
2821 static __init int register_event_cmds(void)
2822 {
2823 int ret;
2824
2825 ret = register_ftrace_command(&event_enable_cmd);
2826 if (WARN_ON(ret < 0))
2827 return ret;
2828 ret = register_ftrace_command(&event_disable_cmd);
2829 if (WARN_ON(ret < 0))
2830 unregister_ftrace_command(&event_enable_cmd);
2831 return ret;
2832 }
2833 #else
2834 static inline int register_event_cmds(void) { return 0; }
2835 #endif /* CONFIG_DYNAMIC_FTRACE */
2836
2837 /*
2838 * The top level array has already had its trace_event_file
2839 * descriptors created in order to allow for early events to
2840 * be recorded. This function is called after the tracefs has been
2841 * initialized, and we now have to create the files associated
2842 * to the events.
2843 */
2844 static __init void
2845 __trace_early_add_event_dirs(struct trace_array *tr)
2846 {
2847 struct trace_event_file *file;
2848 int ret;
2849
2850
2851 list_for_each_entry(file, &tr->events, list) {
2852 ret = event_create_dir(tr->event_dir, file);
2853 if (ret < 0)
2854 pr_warn("Could not create directory for event %s\n",
2855 trace_event_name(file->event_call));
2856 }
2857 }
2858
2859 /*
2860 * For early boot up, the top trace array requires to have
2861 * a list of events that can be enabled. This must be done before
2862 * the filesystem is set up in order to allow events to be traced
2863 * early.
2864 */
2865 static __init void
2866 __trace_early_add_events(struct trace_array *tr)
2867 {
2868 struct trace_event_call *call;
2869 int ret;
2870
2871 list_for_each_entry(call, &ftrace_events, list) {
2872 /* Early boot up should not have any modules loaded */
2873 if (WARN_ON_ONCE(call->mod))
2874 continue;
2875
2876 ret = __trace_early_add_new_event(call, tr);
2877 if (ret < 0)
2878 pr_warn("Could not create early event %s\n",
2879 trace_event_name(call));
2880 }
2881 }
2882
2883 /* Remove the event directory structure for a trace directory. */
2884 static void
2885 __trace_remove_event_dirs(struct trace_array *tr)
2886 {
2887 struct trace_event_file *file, *next;
2888
2889 list_for_each_entry_safe(file, next, &tr->events, list)
2890 remove_event_file_dir(file);
2891 }
2892
2893 static void __add_event_to_tracers(struct trace_event_call *call)
2894 {
2895 struct trace_array *tr;
2896
2897 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2898 __trace_add_new_event(call, tr);
2899 }
2900
2901 extern struct trace_event_call *__start_ftrace_events[];
2902 extern struct trace_event_call *__stop_ftrace_events[];
2903
2904 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2905
2906 static __init int setup_trace_event(char *str)
2907 {
2908 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2909 ring_buffer_expanded = true;
2910 tracing_selftest_disabled = true;
2911
2912 return 1;
2913 }
2914 __setup("trace_event=", setup_trace_event);
2915
2916 /* Expects to have event_mutex held when called */
2917 static int
2918 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2919 {
2920 struct dentry *d_events;
2921 struct dentry *entry;
2922
2923 entry = tracefs_create_file("set_event", 0644, parent,
2924 tr, &ftrace_set_event_fops);
2925 if (!entry) {
2926 pr_warn("Could not create tracefs 'set_event' entry\n");
2927 return -ENOMEM;
2928 }
2929
2930 d_events = tracefs_create_dir("events", parent);
2931 if (!d_events) {
2932 pr_warn("Could not create tracefs 'events' directory\n");
2933 return -ENOMEM;
2934 }
2935
2936 entry = trace_create_file("enable", 0644, d_events,
2937 tr, &ftrace_tr_enable_fops);
2938 if (!entry) {
2939 pr_warn("Could not create tracefs 'enable' entry\n");
2940 return -ENOMEM;
2941 }
2942
2943 /* There are not as crucial, just warn if they are not created */
2944
2945 entry = tracefs_create_file("set_event_pid", 0644, parent,
2946 tr, &ftrace_set_event_pid_fops);
2947 if (!entry)
2948 pr_warn("Could not create tracefs 'set_event_pid' entry\n");
2949
2950 /* ring buffer internal formats */
2951 entry = trace_create_file("header_page", 0444, d_events,
2952 ring_buffer_print_page_header,
2953 &ftrace_show_header_fops);
2954 if (!entry)
2955 pr_warn("Could not create tracefs 'header_page' entry\n");
2956
2957 entry = trace_create_file("header_event", 0444, d_events,
2958 ring_buffer_print_entry_header,
2959 &ftrace_show_header_fops);
2960 if (!entry)
2961 pr_warn("Could not create tracefs 'header_event' entry\n");
2962
2963 tr->event_dir = d_events;
2964
2965 return 0;
2966 }
2967
2968 /**
2969 * event_trace_add_tracer - add a instance of a trace_array to events
2970 * @parent: The parent dentry to place the files/directories for events in
2971 * @tr: The trace array associated with these events
2972 *
2973 * When a new instance is created, it needs to set up its events
2974 * directory, as well as other files associated with events. It also
2975 * creates the event hierachry in the @parent/events directory.
2976 *
2977 * Returns 0 on success.
2978 *
2979 * Must be called with event_mutex held.
2980 */
2981 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2982 {
2983 int ret;
2984
2985 lockdep_assert_held(&event_mutex);
2986
2987 ret = create_event_toplevel_files(parent, tr);
2988 if (ret)
2989 goto out;
2990
2991 down_write(&trace_event_sem);
2992 __trace_add_event_dirs(tr);
2993 up_write(&trace_event_sem);
2994
2995 out:
2996 return ret;
2997 }
2998
2999 /*
3000 * The top trace array already had its file descriptors created.
3001 * Now the files themselves need to be created.
3002 */
3003 static __init int
3004 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
3005 {
3006 int ret;
3007
3008 mutex_lock(&event_mutex);
3009
3010 ret = create_event_toplevel_files(parent, tr);
3011 if (ret)
3012 goto out_unlock;
3013
3014 down_write(&trace_event_sem);
3015 __trace_early_add_event_dirs(tr);
3016 up_write(&trace_event_sem);
3017
3018 out_unlock:
3019 mutex_unlock(&event_mutex);
3020
3021 return ret;
3022 }
3023
3024 /* Must be called with event_mutex held */
3025 int event_trace_del_tracer(struct trace_array *tr)
3026 {
3027 lockdep_assert_held(&event_mutex);
3028
3029 /* Disable any event triggers and associated soft-disabled events */
3030 clear_event_triggers(tr);
3031
3032 /* Clear the pid list */
3033 __ftrace_clear_event_pids(tr);
3034
3035 /* Disable any running events */
3036 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3037
3038 /* Make sure no more events are being executed */
3039 tracepoint_synchronize_unregister();
3040
3041 down_write(&trace_event_sem);
3042 __trace_remove_event_dirs(tr);
3043 tracefs_remove_recursive(tr->event_dir);
3044 up_write(&trace_event_sem);
3045
3046 tr->event_dir = NULL;
3047
3048 return 0;
3049 }
3050
3051 static __init int event_trace_memsetup(void)
3052 {
3053 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3054 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3055 return 0;
3056 }
3057
3058 static __init void
3059 early_enable_events(struct trace_array *tr, bool disable_first)
3060 {
3061 char *buf = bootup_event_buf;
3062 char *token;
3063 int ret;
3064
3065 while (true) {
3066 token = strsep(&buf, ",");
3067
3068 if (!token)
3069 break;
3070
3071 if (*token) {
3072 /* Restarting syscalls requires that we stop them first */
3073 if (disable_first)
3074 ftrace_set_clr_event(tr, token, 0);
3075
3076 ret = ftrace_set_clr_event(tr, token, 1);
3077 if (ret)
3078 pr_warn("Failed to enable trace event: %s\n", token);
3079 }
3080
3081 /* Put back the comma to allow this to be called again */
3082 if (buf)
3083 *(buf - 1) = ',';
3084 }
3085 }
3086
3087 static __init int event_trace_enable(void)
3088 {
3089 struct trace_array *tr = top_trace_array();
3090 struct trace_event_call **iter, *call;
3091 int ret;
3092
3093 if (!tr)
3094 return -ENODEV;
3095
3096 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3097
3098 call = *iter;
3099 ret = event_init(call);
3100 if (!ret)
3101 list_add(&call->list, &ftrace_events);
3102 }
3103
3104 /*
3105 * We need the top trace array to have a working set of trace
3106 * points at early init, before the debug files and directories
3107 * are created. Create the file entries now, and attach them
3108 * to the actual file dentries later.
3109 */
3110 __trace_early_add_events(tr);
3111
3112 early_enable_events(tr, false);
3113
3114 trace_printk_start_comm();
3115
3116 register_event_cmds();
3117
3118 register_trigger_cmds();
3119
3120 return 0;
3121 }
3122
3123 /*
3124 * event_trace_enable() is called from trace_event_init() first to
3125 * initialize events and perhaps start any events that are on the
3126 * command line. Unfortunately, there are some events that will not
3127 * start this early, like the system call tracepoints that need
3128 * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
3129 * is called before pid 1 starts, and this flag is never set, making
3130 * the syscall tracepoint never get reached, but the event is enabled
3131 * regardless (and not doing anything).
3132 */
3133 static __init int event_trace_enable_again(void)
3134 {
3135 struct trace_array *tr;
3136
3137 tr = top_trace_array();
3138 if (!tr)
3139 return -ENODEV;
3140
3141 early_enable_events(tr, true);
3142
3143 return 0;
3144 }
3145
3146 early_initcall(event_trace_enable_again);
3147
3148 __init int event_trace_init(void)
3149 {
3150 struct trace_array *tr;
3151 struct dentry *d_tracer;
3152 struct dentry *entry;
3153 int ret;
3154
3155 tr = top_trace_array();
3156 if (!tr)
3157 return -ENODEV;
3158
3159 d_tracer = tracing_init_dentry();
3160 if (IS_ERR(d_tracer))
3161 return 0;
3162
3163 entry = tracefs_create_file("available_events", 0444, d_tracer,
3164 tr, &ftrace_avail_fops);
3165 if (!entry)
3166 pr_warn("Could not create tracefs 'available_events' entry\n");
3167
3168 if (trace_define_generic_fields())
3169 pr_warn("tracing: Failed to allocated generic fields");
3170
3171 if (trace_define_common_fields())
3172 pr_warn("tracing: Failed to allocate common fields");
3173
3174 ret = early_event_add_tracer(d_tracer, tr);
3175 if (ret)
3176 return ret;
3177
3178 #ifdef CONFIG_MODULES
3179 ret = register_module_notifier(&trace_module_nb);
3180 if (ret)
3181 pr_warn("Failed to register trace events module notifier\n");
3182 #endif
3183 return 0;
3184 }
3185
3186 void __init trace_event_init(void)
3187 {
3188 event_trace_memsetup();
3189 init_ftrace_syscalls();
3190 event_trace_enable();
3191 }
3192
3193 #ifdef CONFIG_FTRACE_STARTUP_TEST
3194
3195 static DEFINE_SPINLOCK(test_spinlock);
3196 static DEFINE_SPINLOCK(test_spinlock_irq);
3197 static DEFINE_MUTEX(test_mutex);
3198
3199 static __init void test_work(struct work_struct *dummy)
3200 {
3201 spin_lock(&test_spinlock);
3202 spin_lock_irq(&test_spinlock_irq);
3203 udelay(1);
3204 spin_unlock_irq(&test_spinlock_irq);
3205 spin_unlock(&test_spinlock);
3206
3207 mutex_lock(&test_mutex);
3208 msleep(1);
3209 mutex_unlock(&test_mutex);
3210 }
3211
3212 static __init int event_test_thread(void *unused)
3213 {
3214 void *test_malloc;
3215
3216 test_malloc = kmalloc(1234, GFP_KERNEL);
3217 if (!test_malloc)
3218 pr_info("failed to kmalloc\n");
3219
3220 schedule_on_each_cpu(test_work);
3221
3222 kfree(test_malloc);
3223
3224 set_current_state(TASK_INTERRUPTIBLE);
3225 while (!kthread_should_stop()) {
3226 schedule();
3227 set_current_state(TASK_INTERRUPTIBLE);
3228 }
3229 __set_current_state(TASK_RUNNING);
3230
3231 return 0;
3232 }
3233
3234 /*
3235 * Do various things that may trigger events.
3236 */
3237 static __init void event_test_stuff(void)
3238 {
3239 struct task_struct *test_thread;
3240
3241 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3242 msleep(1);
3243 kthread_stop(test_thread);
3244 }
3245
3246 /*
3247 * For every trace event defined, we will test each trace point separately,
3248 * and then by groups, and finally all trace points.
3249 */
3250 static __init void event_trace_self_tests(void)
3251 {
3252 struct trace_subsystem_dir *dir;
3253 struct trace_event_file *file;
3254 struct trace_event_call *call;
3255 struct event_subsystem *system;
3256 struct trace_array *tr;
3257 int ret;
3258
3259 tr = top_trace_array();
3260 if (!tr)
3261 return;
3262
3263 pr_info("Running tests on trace events:\n");
3264
3265 list_for_each_entry(file, &tr->events, list) {
3266
3267 call = file->event_call;
3268
3269 /* Only test those that have a probe */
3270 if (!call->class || !call->class->probe)
3271 continue;
3272
3273 /*
3274 * Testing syscall events here is pretty useless, but
3275 * we still do it if configured. But this is time consuming.
3276 * What we really need is a user thread to perform the
3277 * syscalls as we test.
3278 */
3279 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3280 if (call->class->system &&
3281 strcmp(call->class->system, "syscalls") == 0)
3282 continue;
3283 #endif
3284
3285 pr_info("Testing event %s: ", trace_event_name(call));
3286
3287 /*
3288 * If an event is already enabled, someone is using
3289 * it and the self test should not be on.
3290 */
3291 if (file->flags & EVENT_FILE_FL_ENABLED) {
3292 pr_warn("Enabled event during self test!\n");
3293 WARN_ON_ONCE(1);
3294 continue;
3295 }
3296
3297 ftrace_event_enable_disable(file, 1);
3298 event_test_stuff();
3299 ftrace_event_enable_disable(file, 0);
3300
3301 pr_cont("OK\n");
3302 }
3303
3304 /* Now test at the sub system level */
3305
3306 pr_info("Running tests on trace event systems:\n");
3307
3308 list_for_each_entry(dir, &tr->systems, list) {
3309
3310 system = dir->subsystem;
3311
3312 /* the ftrace system is special, skip it */
3313 if (strcmp(system->name, "ftrace") == 0)
3314 continue;
3315
3316 pr_info("Testing event system %s: ", system->name);
3317
3318 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3319 if (WARN_ON_ONCE(ret)) {
3320 pr_warn("error enabling system %s\n",
3321 system->name);
3322 continue;
3323 }
3324
3325 event_test_stuff();
3326
3327 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3328 if (WARN_ON_ONCE(ret)) {
3329 pr_warn("error disabling system %s\n",
3330 system->name);
3331 continue;
3332 }
3333
3334 pr_cont("OK\n");
3335 }
3336
3337 /* Test with all events enabled */
3338
3339 pr_info("Running tests on all trace events:\n");
3340 pr_info("Testing all events: ");
3341
3342 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3343 if (WARN_ON_ONCE(ret)) {
3344 pr_warn("error enabling all events\n");
3345 return;
3346 }
3347
3348 event_test_stuff();
3349
3350 /* reset sysname */
3351 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3352 if (WARN_ON_ONCE(ret)) {
3353 pr_warn("error disabling all events\n");
3354 return;
3355 }
3356
3357 pr_cont("OK\n");
3358 }
3359
3360 #ifdef CONFIG_FUNCTION_TRACER
3361
3362 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3363
3364 static struct trace_event_file event_trace_file __initdata;
3365
3366 static void __init
3367 function_test_events_call(unsigned long ip, unsigned long parent_ip,
3368 struct ftrace_ops *op, struct pt_regs *pt_regs)
3369 {
3370 struct ring_buffer_event *event;
3371 struct ring_buffer *buffer;
3372 struct ftrace_entry *entry;
3373 unsigned long flags;
3374 long disabled;
3375 int cpu;
3376 int pc;
3377
3378 pc = preempt_count();
3379 preempt_disable_notrace();
3380 cpu = raw_smp_processor_id();
3381 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3382
3383 if (disabled != 1)
3384 goto out;
3385
3386 local_save_flags(flags);
3387
3388 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
3389 TRACE_FN, sizeof(*entry),
3390 flags, pc);
3391 if (!event)
3392 goto out;
3393 entry = ring_buffer_event_data(event);
3394 entry->ip = ip;
3395 entry->parent_ip = parent_ip;
3396
3397 event_trigger_unlock_commit(&event_trace_file, buffer, event,
3398 entry, flags, pc);
3399 out:
3400 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3401 preempt_enable_notrace();
3402 }
3403
3404 static struct ftrace_ops trace_ops __initdata =
3405 {
3406 .func = function_test_events_call,
3407 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
3408 };
3409
3410 static __init void event_trace_self_test_with_function(void)
3411 {
3412 int ret;
3413
3414 event_trace_file.tr = top_trace_array();
3415 if (WARN_ON(!event_trace_file.tr))
3416 return;
3417
3418 ret = register_ftrace_function(&trace_ops);
3419 if (WARN_ON(ret < 0)) {
3420 pr_info("Failed to enable function tracer for event tests\n");
3421 return;
3422 }
3423 pr_info("Running tests again, along with the function tracer\n");
3424 event_trace_self_tests();
3425 unregister_ftrace_function(&trace_ops);
3426 }
3427 #else
3428 static __init void event_trace_self_test_with_function(void)
3429 {
3430 }
3431 #endif
3432
3433 static __init int event_trace_self_tests_init(void)
3434 {
3435 if (!tracing_selftest_disabled) {
3436 event_trace_self_tests();
3437 event_trace_self_test_with_function();
3438 }
3439
3440 return 0;
3441 }
3442
3443 late_initcall(event_trace_self_tests_init);
3444
3445 #endif
Linux with added FPC-III support