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