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