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Staging: most: Do not print message if kzalloc() failed.
[linux/fpc-iii.git] / kernel / trace / trace_events.c
blobf333e57c4614a2a6aaac04061003f73cd3a6d844
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
34 DEFINE_MUTEX(event_mutex);
35
36 LIST_HEAD(ftrace_events);
37 static LIST_HEAD(ftrace_generic_fields);
38 static LIST_HEAD(ftrace_common_fields);
39
40 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
41
42 static struct kmem_cache *field_cachep;
43 static struct kmem_cache *file_cachep;
44
45 static inline int system_refcount(struct event_subsystem *system)
46 {
47 return system->ref_count;
48 }
49
50 static int system_refcount_inc(struct event_subsystem *system)
51 {
52 return system->ref_count++;
53 }
54
55 static int system_refcount_dec(struct event_subsystem *system)
56 {
57 return --system->ref_count;
58 }
59
60 /* Double loops, do not use break, only goto's work */
61 #define do_for_each_event_file(tr, file) \
62 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
63 list_for_each_entry(file, &tr->events, list)
64
65 #define do_for_each_event_file_safe(tr, file) \
66 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
67 struct trace_event_file *___n; \
68 list_for_each_entry_safe(file, ___n, &tr->events, list)
69
70 #define while_for_each_event_file() \
71 }
72
73 static struct list_head *
74 trace_get_fields(struct trace_event_call *event_call)
75 {
76 if (!event_call->class->get_fields)
77 return &event_call->class->fields;
78 return event_call->class->get_fields(event_call);
79 }
80
81 static struct ftrace_event_field *
82 __find_event_field(struct list_head *head, char *name)
83 {
84 struct ftrace_event_field *field;
85
86 list_for_each_entry(field, head, link) {
87 if (!strcmp(field->name, name))
88 return field;
89 }
90
91 return NULL;
92 }
93
94 struct ftrace_event_field *
95 trace_find_event_field(struct trace_event_call *call, char *name)
96 {
97 struct ftrace_event_field *field;
98 struct list_head *head;
99
100 field = __find_event_field(&ftrace_generic_fields, name);
101 if (field)
102 return field;
103
104 field = __find_event_field(&ftrace_common_fields, name);
105 if (field)
106 return field;
107
108 head = trace_get_fields(call);
109 return __find_event_field(head, name);
110 }
111
112 static int __trace_define_field(struct list_head *head, const char *type,
113 const char *name, int offset, int size,
114 int is_signed, int filter_type)
115 {
116 struct ftrace_event_field *field;
117
118 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
119 if (!field)
120 return -ENOMEM;
121
122 field->name = name;
123 field->type = type;
124
125 if (filter_type == FILTER_OTHER)
126 field->filter_type = filter_assign_type(type);
127 else
128 field->filter_type = filter_type;
129
130 field->offset = offset;
131 field->size = size;
132 field->is_signed = is_signed;
133
134 list_add(&field->link, head);
135
136 return 0;
137 }
138
139 int trace_define_field(struct trace_event_call *call, const char *type,
140 const char *name, int offset, int size, int is_signed,
141 int filter_type)
142 {
143 struct list_head *head;
144
145 if (WARN_ON(!call->class))
146 return 0;
147
148 head = trace_get_fields(call);
149 return __trace_define_field(head, type, name, offset, size,
150 is_signed, filter_type);
151 }
152 EXPORT_SYMBOL_GPL(trace_define_field);
153
154 #define __generic_field(type, item, filter_type) \
155 ret = __trace_define_field(&ftrace_generic_fields, #type, \
156 #item, 0, 0, is_signed_type(type), \
157 filter_type); \
158 if (ret) \
159 return ret;
160
161 #define __common_field(type, item) \
162 ret = __trace_define_field(&ftrace_common_fields, #type, \
163 "common_" #item, \
164 offsetof(typeof(ent), item), \
165 sizeof(ent.item), \
166 is_signed_type(type), FILTER_OTHER); \
167 if (ret) \
168 return ret;
169
170 static int trace_define_generic_fields(void)
171 {
172 int ret;
173
174 __generic_field(int, cpu, FILTER_OTHER);
175 __generic_field(char *, comm, FILTER_PTR_STRING);
176
177 return ret;
178 }
179
180 static int trace_define_common_fields(void)
181 {
182 int ret;
183 struct trace_entry ent;
184
185 __common_field(unsigned short, type);
186 __common_field(unsigned char, flags);
187 __common_field(unsigned char, preempt_count);
188 __common_field(int, pid);
189
190 return ret;
191 }
192
193 static void trace_destroy_fields(struct trace_event_call *call)
194 {
195 struct ftrace_event_field *field, *next;
196 struct list_head *head;
197
198 head = trace_get_fields(call);
199 list_for_each_entry_safe(field, next, head, link) {
200 list_del(&field->link);
201 kmem_cache_free(field_cachep, field);
202 }
203 }
204
205 int trace_event_raw_init(struct trace_event_call *call)
206 {
207 int id;
208
209 id = register_trace_event(&call->event);
210 if (!id)
211 return -ENODEV;
212
213 return 0;
214 }
215 EXPORT_SYMBOL_GPL(trace_event_raw_init);
216
217 bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
218 {
219 struct trace_array *tr = trace_file->tr;
220 struct trace_array_cpu *data;
221 struct trace_pid_list *pid_list;
222
223 pid_list = rcu_dereference_sched(tr->filtered_pids);
224 if (!pid_list)
225 return false;
226
227 data = this_cpu_ptr(tr->trace_buffer.data);
228
229 return data->ignore_pid;
230 }
231 EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
232
233 void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
234 struct trace_event_file *trace_file,
235 unsigned long len)
236 {
237 struct trace_event_call *event_call = trace_file->event_call;
238
239 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
240 trace_event_ignore_this_pid(trace_file))
241 return NULL;
242
243 local_save_flags(fbuffer->flags);
244 fbuffer->pc = preempt_count();
245 fbuffer->trace_file = trace_file;
246
247 fbuffer->event =
248 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
249 event_call->event.type, len,
250 fbuffer->flags, fbuffer->pc);
251 if (!fbuffer->event)
252 return NULL;
253
254 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
255 return fbuffer->entry;
256 }
257 EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
258
259 static DEFINE_SPINLOCK(tracepoint_iter_lock);
260
261 static void output_printk(struct trace_event_buffer *fbuffer)
262 {
263 struct trace_event_call *event_call;
264 struct trace_event *event;
265 unsigned long flags;
266 struct trace_iterator *iter = tracepoint_print_iter;
267
268 if (!iter)
269 return;
270
271 event_call = fbuffer->trace_file->event_call;
272 if (!event_call || !event_call->event.funcs ||
273 !event_call->event.funcs->trace)
274 return;
275
276 event = &fbuffer->trace_file->event_call->event;
277
278 spin_lock_irqsave(&tracepoint_iter_lock, flags);
279 trace_seq_init(&iter->seq);
280 iter->ent = fbuffer->entry;
281 event_call->event.funcs->trace(iter, 0, event);
282 trace_seq_putc(&iter->seq, 0);
283 printk("%s", iter->seq.buffer);
284
285 spin_unlock_irqrestore(&tracepoint_iter_lock, flags);
286 }
287
288 void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)
289 {
290 if (tracepoint_printk)
291 output_printk(fbuffer);
292
293 event_trigger_unlock_commit(fbuffer->trace_file, fbuffer->buffer,
294 fbuffer->event, fbuffer->entry,
295 fbuffer->flags, fbuffer->pc);
296 }
297 EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
298
299 int trace_event_reg(struct trace_event_call *call,
300 enum trace_reg type, void *data)
301 {
302 struct trace_event_file *file = data;
303
304 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
305 switch (type) {
306 case TRACE_REG_REGISTER:
307 return tracepoint_probe_register(call->tp,
308 call->class->probe,
309 file);
310 case TRACE_REG_UNREGISTER:
311 tracepoint_probe_unregister(call->tp,
312 call->class->probe,
313 file);
314 return 0;
315
316 #ifdef CONFIG_PERF_EVENTS
317 case TRACE_REG_PERF_REGISTER:
318 return tracepoint_probe_register(call->tp,
319 call->class->perf_probe,
320 call);
321 case TRACE_REG_PERF_UNREGISTER:
322 tracepoint_probe_unregister(call->tp,
323 call->class->perf_probe,
324 call);
325 return 0;
326 case TRACE_REG_PERF_OPEN:
327 case TRACE_REG_PERF_CLOSE:
328 case TRACE_REG_PERF_ADD:
329 case TRACE_REG_PERF_DEL:
330 return 0;
331 #endif
332 }
333 return 0;
334 }
335 EXPORT_SYMBOL_GPL(trace_event_reg);
336
337 void trace_event_enable_cmd_record(bool enable)
338 {
339 struct trace_event_file *file;
340 struct trace_array *tr;
341
342 mutex_lock(&event_mutex);
343 do_for_each_event_file(tr, file) {
344
345 if (!(file->flags & EVENT_FILE_FL_ENABLED))
346 continue;
347
348 if (enable) {
349 tracing_start_cmdline_record();
350 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
351 } else {
352 tracing_stop_cmdline_record();
353 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
354 }
355 } while_for_each_event_file();
356 mutex_unlock(&event_mutex);
357 }
358
359 static int __ftrace_event_enable_disable(struct trace_event_file *file,
360 int enable, int soft_disable)
361 {
362 struct trace_event_call *call = file->event_call;
363 struct trace_array *tr = file->tr;
364 int ret = 0;
365 int disable;
366
367 switch (enable) {
368 case 0:
369 /*
370 * When soft_disable is set and enable is cleared, the sm_ref
371 * reference counter is decremented. If it reaches 0, we want
372 * to clear the SOFT_DISABLED flag but leave the event in the
373 * state that it was. That is, if the event was enabled and
374 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
375 * is set we do not want the event to be enabled before we
376 * clear the bit.
377 *
378 * When soft_disable is not set but the SOFT_MODE flag is,
379 * we do nothing. Do not disable the tracepoint, otherwise
380 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
381 */
382 if (soft_disable) {
383 if (atomic_dec_return(&file->sm_ref) > 0)
384 break;
385 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
386 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
387 } else
388 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
389
390 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
391 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
392 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
393 tracing_stop_cmdline_record();
394 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
395 }
396 call->class->reg(call, TRACE_REG_UNREGISTER, file);
397 }
398 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
399 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
400 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
401 else
402 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
403 break;
404 case 1:
405 /*
406 * When soft_disable is set and enable is set, we want to
407 * register the tracepoint for the event, but leave the event
408 * as is. That means, if the event was already enabled, we do
409 * nothing (but set SOFT_MODE). If the event is disabled, we
410 * set SOFT_DISABLED before enabling the event tracepoint, so
411 * it still seems to be disabled.
412 */
413 if (!soft_disable)
414 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
415 else {
416 if (atomic_inc_return(&file->sm_ref) > 1)
417 break;
418 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
419 }
420
421 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
422
423 /* Keep the event disabled, when going to SOFT_MODE. */
424 if (soft_disable)
425 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
426
427 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
428 tracing_start_cmdline_record();
429 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
430 }
431 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
432 if (ret) {
433 tracing_stop_cmdline_record();
434 pr_info("event trace: Could not enable event "
435 "%s\n", trace_event_name(call));
436 break;
437 }
438 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
439
440 /* WAS_ENABLED gets set but never cleared. */
441 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
442 }
443 break;
444 }
445
446 return ret;
447 }
448
449 int trace_event_enable_disable(struct trace_event_file *file,
450 int enable, int soft_disable)
451 {
452 return __ftrace_event_enable_disable(file, enable, soft_disable);
453 }
454
455 static int ftrace_event_enable_disable(struct trace_event_file *file,
456 int enable)
457 {
458 return __ftrace_event_enable_disable(file, enable, 0);
459 }
460
461 static void ftrace_clear_events(struct trace_array *tr)
462 {
463 struct trace_event_file *file;
464
465 mutex_lock(&event_mutex);
466 list_for_each_entry(file, &tr->events, list) {
467 ftrace_event_enable_disable(file, 0);
468 }
469 mutex_unlock(&event_mutex);
470 }
471
472 static int cmp_pid(const void *key, const void *elt)
473 {
474 const pid_t *search_pid = key;
475 const pid_t *pid = elt;
476
477 if (*search_pid == *pid)
478 return 0;
479 if (*search_pid < *pid)
480 return -1;
481 return 1;
482 }
483
484 static bool
485 check_ignore_pid(struct trace_pid_list *filtered_pids, struct task_struct *task)
486 {
487 pid_t search_pid;
488 pid_t *pid;
489
490 /*
491 * Return false, because if filtered_pids does not exist,
492 * all pids are good to trace.
493 */
494 if (!filtered_pids)
495 return false;
496
497 search_pid = task->pid;
498
499 pid = bsearch(&search_pid, filtered_pids->pids,
500 filtered_pids->nr_pids, sizeof(pid_t),
501 cmp_pid);
502 if (!pid)
503 return true;
504
505 return false;
506 }
507
508 static void
509 event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
510 struct task_struct *prev, struct task_struct *next)
511 {
512 struct trace_array *tr = data;
513 struct trace_pid_list *pid_list;
514
515 pid_list = rcu_dereference_sched(tr->filtered_pids);
516
517 this_cpu_write(tr->trace_buffer.data->ignore_pid,
518 check_ignore_pid(pid_list, prev) &&
519 check_ignore_pid(pid_list, next));
520 }
521
522 static void
523 event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
524 struct task_struct *prev, struct task_struct *next)
525 {
526 struct trace_array *tr = data;
527 struct trace_pid_list *pid_list;
528
529 pid_list = rcu_dereference_sched(tr->filtered_pids);
530
531 this_cpu_write(tr->trace_buffer.data->ignore_pid,
532 check_ignore_pid(pid_list, next));
533 }
534
535 static void
536 event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
537 {
538 struct trace_array *tr = data;
539 struct trace_pid_list *pid_list;
540
541 /* Nothing to do if we are already tracing */
542 if (!this_cpu_read(tr->trace_buffer.data->ignore_pid))
543 return;
544
545 pid_list = rcu_dereference_sched(tr->filtered_pids);
546
547 this_cpu_write(tr->trace_buffer.data->ignore_pid,
548 check_ignore_pid(pid_list, task));
549 }
550
551 static void
552 event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
553 {
554 struct trace_array *tr = data;
555 struct trace_pid_list *pid_list;
556
557 /* Nothing to do if we are not tracing */
558 if (this_cpu_read(tr->trace_buffer.data->ignore_pid))
559 return;
560
561 pid_list = rcu_dereference_sched(tr->filtered_pids);
562
563 /* Set tracing if current is enabled */
564 this_cpu_write(tr->trace_buffer.data->ignore_pid,
565 check_ignore_pid(pid_list, current));
566 }
567
568 static void __ftrace_clear_event_pids(struct trace_array *tr)
569 {
570 struct trace_pid_list *pid_list;
571 struct trace_event_file *file;
572 int cpu;
573
574 pid_list = rcu_dereference_protected(tr->filtered_pids,
575 lockdep_is_held(&event_mutex));
576 if (!pid_list)
577 return;
578
579 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
580 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
581
582 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
583 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
584
585 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
586 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
587
588 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
589 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
590
591 list_for_each_entry(file, &tr->events, list) {
592 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
593 }
594
595 for_each_possible_cpu(cpu)
596 per_cpu_ptr(tr->trace_buffer.data, cpu)->ignore_pid = false;
597
598 rcu_assign_pointer(tr->filtered_pids, NULL);
599
600 /* Wait till all users are no longer using pid filtering */
601 synchronize_sched();
602
603 free_pages((unsigned long)pid_list->pids, pid_list->order);
604 kfree(pid_list);
605 }
606
607 static void ftrace_clear_event_pids(struct trace_array *tr)
608 {
609 mutex_lock(&event_mutex);
610 __ftrace_clear_event_pids(tr);
611 mutex_unlock(&event_mutex);
612 }
613
614 static void __put_system(struct event_subsystem *system)
615 {
616 struct event_filter *filter = system->filter;
617
618 WARN_ON_ONCE(system_refcount(system) == 0);
619 if (system_refcount_dec(system))
620 return;
621
622 list_del(&system->list);
623
624 if (filter) {
625 kfree(filter->filter_string);
626 kfree(filter);
627 }
628 kfree_const(system->name);
629 kfree(system);
630 }
631
632 static void __get_system(struct event_subsystem *system)
633 {
634 WARN_ON_ONCE(system_refcount(system) == 0);
635 system_refcount_inc(system);
636 }
637
638 static void __get_system_dir(struct trace_subsystem_dir *dir)
639 {
640 WARN_ON_ONCE(dir->ref_count == 0);
641 dir->ref_count++;
642 __get_system(dir->subsystem);
643 }
644
645 static void __put_system_dir(struct trace_subsystem_dir *dir)
646 {
647 WARN_ON_ONCE(dir->ref_count == 0);
648 /* If the subsystem is about to be freed, the dir must be too */
649 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
650
651 __put_system(dir->subsystem);
652 if (!--dir->ref_count)
653 kfree(dir);
654 }
655
656 static void put_system(struct trace_subsystem_dir *dir)
657 {
658 mutex_lock(&event_mutex);
659 __put_system_dir(dir);
660 mutex_unlock(&event_mutex);
661 }
662
663 static void remove_subsystem(struct trace_subsystem_dir *dir)
664 {
665 if (!dir)
666 return;
667
668 if (!--dir->nr_events) {
669 tracefs_remove_recursive(dir->entry);
670 list_del(&dir->list);
671 __put_system_dir(dir);
672 }
673 }
674
675 static void remove_event_file_dir(struct trace_event_file *file)
676 {
677 struct dentry *dir = file->dir;
678 struct dentry *child;
679
680 if (dir) {
681 spin_lock(&dir->d_lock); /* probably unneeded */
682 list_for_each_entry(child, &dir->d_subdirs, d_child) {
683 if (d_really_is_positive(child)) /* probably unneeded */
684 d_inode(child)->i_private = NULL;
685 }
686 spin_unlock(&dir->d_lock);
687
688 tracefs_remove_recursive(dir);
689 }
690
691 list_del(&file->list);
692 remove_subsystem(file->system);
693 free_event_filter(file->filter);
694 kmem_cache_free(file_cachep, file);
695 }
696
697 /*
698 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
699 */
700 static int
701 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
702 const char *sub, const char *event, int set)
703 {
704 struct trace_event_file *file;
705 struct trace_event_call *call;
706 const char *name;
707 int ret = -EINVAL;
708
709 list_for_each_entry(file, &tr->events, list) {
710
711 call = file->event_call;
712 name = trace_event_name(call);
713
714 if (!name || !call->class || !call->class->reg)
715 continue;
716
717 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
718 continue;
719
720 if (match &&
721 strcmp(match, name) != 0 &&
722 strcmp(match, call->class->system) != 0)
723 continue;
724
725 if (sub && strcmp(sub, call->class->system) != 0)
726 continue;
727
728 if (event && strcmp(event, name) != 0)
729 continue;
730
731 ftrace_event_enable_disable(file, set);
732
733 ret = 0;
734 }
735
736 return ret;
737 }
738
739 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
740 const char *sub, const char *event, int set)
741 {
742 int ret;
743
744 mutex_lock(&event_mutex);
745 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
746 mutex_unlock(&event_mutex);
747
748 return ret;
749 }
750
751 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
752 {
753 char *event = NULL, *sub = NULL, *match;
754 int ret;
755
756 /*
757 * The buf format can be <subsystem>:<event-name>
758 * *:<event-name> means any event by that name.
759 * :<event-name> is the same.
760 *
761 * <subsystem>:* means all events in that subsystem
762 * <subsystem>: means the same.
763 *
764 * <name> (no ':') means all events in a subsystem with
765 * the name <name> or any event that matches <name>
766 */
767
768 match = strsep(&buf, ":");
769 if (buf) {
770 sub = match;
771 event = buf;
772 match = NULL;
773
774 if (!strlen(sub) || strcmp(sub, "*") == 0)
775 sub = NULL;
776 if (!strlen(event) || strcmp(event, "*") == 0)
777 event = NULL;
778 }
779
780 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
781
782 /* Put back the colon to allow this to be called again */
783 if (buf)
784 *(buf - 1) = ':';
785
786 return ret;
787 }
788
789 /**
790 * trace_set_clr_event - enable or disable an event
791 * @system: system name to match (NULL for any system)
792 * @event: event name to match (NULL for all events, within system)
793 * @set: 1 to enable, 0 to disable
794 *
795 * This is a way for other parts of the kernel to enable or disable
796 * event recording.
797 *
798 * Returns 0 on success, -EINVAL if the parameters do not match any
799 * registered events.
800 */
801 int trace_set_clr_event(const char *system, const char *event, int set)
802 {
803 struct trace_array *tr = top_trace_array();
804
805 if (!tr)
806 return -ENODEV;
807
808 return __ftrace_set_clr_event(tr, NULL, system, event, set);
809 }
810 EXPORT_SYMBOL_GPL(trace_set_clr_event);
811
812 /* 128 should be much more than enough */
813 #define EVENT_BUF_SIZE 127
814
815 static ssize_t
816 ftrace_event_write(struct file *file, const char __user *ubuf,
817 size_t cnt, loff_t *ppos)
818 {
819 struct trace_parser parser;
820 struct seq_file *m = file->private_data;
821 struct trace_array *tr = m->private;
822 ssize_t read, ret;
823
824 if (!cnt)
825 return 0;
826
827 ret = tracing_update_buffers();
828 if (ret < 0)
829 return ret;
830
831 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
832 return -ENOMEM;
833
834 read = trace_get_user(&parser, ubuf, cnt, ppos);
835
836 if (read >= 0 && trace_parser_loaded((&parser))) {
837 int set = 1;
838
839 if (*parser.buffer == '!')
840 set = 0;
841
842 parser.buffer[parser.idx] = 0;
843
844 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
845 if (ret)
846 goto out_put;
847 }
848
849 ret = read;
850
851 out_put:
852 trace_parser_put(&parser);
853
854 return ret;
855 }
856
857 static void *
858 t_next(struct seq_file *m, void *v, loff_t *pos)
859 {
860 struct trace_event_file *file = v;
861 struct trace_event_call *call;
862 struct trace_array *tr = m->private;
863
864 (*pos)++;
865
866 list_for_each_entry_continue(file, &tr->events, list) {
867 call = file->event_call;
868 /*
869 * The ftrace subsystem is for showing formats only.
870 * They can not be enabled or disabled via the event files.
871 */
872 if (call->class && call->class->reg)
873 return file;
874 }
875
876 return NULL;
877 }
878
879 static void *t_start(struct seq_file *m, loff_t *pos)
880 {
881 struct trace_event_file *file;
882 struct trace_array *tr = m->private;
883 loff_t l;
884
885 mutex_lock(&event_mutex);
886
887 file = list_entry(&tr->events, struct trace_event_file, list);
888 for (l = 0; l <= *pos; ) {
889 file = t_next(m, file, &l);
890 if (!file)
891 break;
892 }
893 return file;
894 }
895
896 static void *
897 s_next(struct seq_file *m, void *v, loff_t *pos)
898 {
899 struct trace_event_file *file = v;
900 struct trace_array *tr = m->private;
901
902 (*pos)++;
903
904 list_for_each_entry_continue(file, &tr->events, list) {
905 if (file->flags & EVENT_FILE_FL_ENABLED)
906 return file;
907 }
908
909 return NULL;
910 }
911
912 static void *s_start(struct seq_file *m, loff_t *pos)
913 {
914 struct trace_event_file *file;
915 struct trace_array *tr = m->private;
916 loff_t l;
917
918 mutex_lock(&event_mutex);
919
920 file = list_entry(&tr->events, struct trace_event_file, list);
921 for (l = 0; l <= *pos; ) {
922 file = s_next(m, file, &l);
923 if (!file)
924 break;
925 }
926 return file;
927 }
928
929 static int t_show(struct seq_file *m, void *v)
930 {
931 struct trace_event_file *file = v;
932 struct trace_event_call *call = file->event_call;
933
934 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
935 seq_printf(m, "%s:", call->class->system);
936 seq_printf(m, "%s\n", trace_event_name(call));
937
938 return 0;
939 }
940
941 static void t_stop(struct seq_file *m, void *p)
942 {
943 mutex_unlock(&event_mutex);
944 }
945
946 static void *p_start(struct seq_file *m, loff_t *pos)
947 __acquires(RCU)
948 {
949 struct trace_pid_list *pid_list;
950 struct trace_array *tr = m->private;
951
952 /*
953 * Grab the mutex, to keep calls to p_next() having the same
954 * tr->filtered_pids as p_start() has.
955 * If we just passed the tr->filtered_pids around, then RCU would
956 * have been enough, but doing that makes things more complex.
957 */
958 mutex_lock(&event_mutex);
959 rcu_read_lock_sched();
960
961 pid_list = rcu_dereference_sched(tr->filtered_pids);
962
963 if (!pid_list || *pos >= pid_list->nr_pids)
964 return NULL;
965
966 return (void *)&pid_list->pids[*pos];
967 }
968
969 static void p_stop(struct seq_file *m, void *p)
970 __releases(RCU)
971 {
972 rcu_read_unlock_sched();
973 mutex_unlock(&event_mutex);
974 }
975
976 static void *
977 p_next(struct seq_file *m, void *v, loff_t *pos)
978 {
979 struct trace_array *tr = m->private;
980 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
981
982 (*pos)++;
983
984 if (*pos >= pid_list->nr_pids)
985 return NULL;
986
987 return (void *)&pid_list->pids[*pos];
988 }
989
990 static int p_show(struct seq_file *m, void *v)
991 {
992 pid_t *pid = v;
993
994 seq_printf(m, "%d\n", *pid);
995 return 0;
996 }
997
998 static ssize_t
999 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1000 loff_t *ppos)
1001 {
1002 struct trace_event_file *file;
1003 unsigned long flags;
1004 char buf[4] = "0";
1005
1006 mutex_lock(&event_mutex);
1007 file = event_file_data(filp);
1008 if (likely(file))
1009 flags = file->flags;
1010 mutex_unlock(&event_mutex);
1011
1012 if (!file)
1013 return -ENODEV;
1014
1015 if (flags & EVENT_FILE_FL_ENABLED &&
1016 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1017 strcpy(buf, "1");
1018
1019 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1020 flags & EVENT_FILE_FL_SOFT_MODE)
1021 strcat(buf, "*");
1022
1023 strcat(buf, "\n");
1024
1025 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1026 }
1027
1028 static ssize_t
1029 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1030 loff_t *ppos)
1031 {
1032 struct trace_event_file *file;
1033 unsigned long val;
1034 int ret;
1035
1036 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1037 if (ret)
1038 return ret;
1039
1040 ret = tracing_update_buffers();
1041 if (ret < 0)
1042 return ret;
1043
1044 switch (val) {
1045 case 0:
1046 case 1:
1047 ret = -ENODEV;
1048 mutex_lock(&event_mutex);
1049 file = event_file_data(filp);
1050 if (likely(file))
1051 ret = ftrace_event_enable_disable(file, val);
1052 mutex_unlock(&event_mutex);
1053 break;
1054
1055 default:
1056 return -EINVAL;
1057 }
1058
1059 *ppos += cnt;
1060
1061 return ret ? ret : cnt;
1062 }
1063
1064 static ssize_t
1065 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1066 loff_t *ppos)
1067 {
1068 const char set_to_char[4] = { '?', '0', '1', 'X' };
1069 struct trace_subsystem_dir *dir = filp->private_data;
1070 struct event_subsystem *system = dir->subsystem;
1071 struct trace_event_call *call;
1072 struct trace_event_file *file;
1073 struct trace_array *tr = dir->tr;
1074 char buf[2];
1075 int set = 0;
1076 int ret;
1077
1078 mutex_lock(&event_mutex);
1079 list_for_each_entry(file, &tr->events, list) {
1080 call = file->event_call;
1081 if (!trace_event_name(call) || !call->class || !call->class->reg)
1082 continue;
1083
1084 if (system && strcmp(call->class->system, system->name) != 0)
1085 continue;
1086
1087 /*
1088 * We need to find out if all the events are set
1089 * or if all events or cleared, or if we have
1090 * a mixture.
1091 */
1092 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1093
1094 /*
1095 * If we have a mixture, no need to look further.
1096 */
1097 if (set == 3)
1098 break;
1099 }
1100 mutex_unlock(&event_mutex);
1101
1102 buf[0] = set_to_char[set];
1103 buf[1] = '\n';
1104
1105 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1106
1107 return ret;
1108 }
1109
1110 static ssize_t
1111 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1112 loff_t *ppos)
1113 {
1114 struct trace_subsystem_dir *dir = filp->private_data;
1115 struct event_subsystem *system = dir->subsystem;
1116 const char *name = NULL;
1117 unsigned long val;
1118 ssize_t ret;
1119
1120 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1121 if (ret)
1122 return ret;
1123
1124 ret = tracing_update_buffers();
1125 if (ret < 0)
1126 return ret;
1127
1128 if (val != 0 && val != 1)
1129 return -EINVAL;
1130
1131 /*
1132 * Opening of "enable" adds a ref count to system,
1133 * so the name is safe to use.
1134 */
1135 if (system)
1136 name = system->name;
1137
1138 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1139 if (ret)
1140 goto out;
1141
1142 ret = cnt;
1143
1144 out:
1145 *ppos += cnt;
1146
1147 return ret;
1148 }
1149
1150 enum {
1151 FORMAT_HEADER = 1,
1152 FORMAT_FIELD_SEPERATOR = 2,
1153 FORMAT_PRINTFMT = 3,
1154 };
1155
1156 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1157 {
1158 struct trace_event_call *call = event_file_data(m->private);
1159 struct list_head *common_head = &ftrace_common_fields;
1160 struct list_head *head = trace_get_fields(call);
1161 struct list_head *node = v;
1162
1163 (*pos)++;
1164
1165 switch ((unsigned long)v) {
1166 case FORMAT_HEADER:
1167 node = common_head;
1168 break;
1169
1170 case FORMAT_FIELD_SEPERATOR:
1171 node = head;
1172 break;
1173
1174 case FORMAT_PRINTFMT:
1175 /* all done */
1176 return NULL;
1177 }
1178
1179 node = node->prev;
1180 if (node == common_head)
1181 return (void *)FORMAT_FIELD_SEPERATOR;
1182 else if (node == head)
1183 return (void *)FORMAT_PRINTFMT;
1184 else
1185 return node;
1186 }
1187
1188 static int f_show(struct seq_file *m, void *v)
1189 {
1190 struct trace_event_call *call = event_file_data(m->private);
1191 struct ftrace_event_field *field;
1192 const char *array_descriptor;
1193
1194 switch ((unsigned long)v) {
1195 case FORMAT_HEADER:
1196 seq_printf(m, "name: %s\n", trace_event_name(call));
1197 seq_printf(m, "ID: %d\n", call->event.type);
1198 seq_puts(m, "format:\n");
1199 return 0;
1200
1201 case FORMAT_FIELD_SEPERATOR:
1202 seq_putc(m, '\n');
1203 return 0;
1204
1205 case FORMAT_PRINTFMT:
1206 seq_printf(m, "\nprint fmt: %s\n",
1207 call->print_fmt);
1208 return 0;
1209 }
1210
1211 field = list_entry(v, struct ftrace_event_field, link);
1212 /*
1213 * Smartly shows the array type(except dynamic array).
1214 * Normal:
1215 * field:TYPE VAR
1216 * If TYPE := TYPE[LEN], it is shown:
1217 * field:TYPE VAR[LEN]
1218 */
1219 array_descriptor = strchr(field->type, '[');
1220
1221 if (!strncmp(field->type, "__data_loc", 10))
1222 array_descriptor = NULL;
1223
1224 if (!array_descriptor)
1225 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1226 field->type, field->name, field->offset,
1227 field->size, !!field->is_signed);
1228 else
1229 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1230 (int)(array_descriptor - field->type),
1231 field->type, field->name,
1232 array_descriptor, field->offset,
1233 field->size, !!field->is_signed);
1234
1235 return 0;
1236 }
1237
1238 static void *f_start(struct seq_file *m, loff_t *pos)
1239 {
1240 void *p = (void *)FORMAT_HEADER;
1241 loff_t l = 0;
1242
1243 /* ->stop() is called even if ->start() fails */
1244 mutex_lock(&event_mutex);
1245 if (!event_file_data(m->private))
1246 return ERR_PTR(-ENODEV);
1247
1248 while (l < *pos && p)
1249 p = f_next(m, p, &l);
1250
1251 return p;
1252 }
1253
1254 static void f_stop(struct seq_file *m, void *p)
1255 {
1256 mutex_unlock(&event_mutex);
1257 }
1258
1259 static const struct seq_operations trace_format_seq_ops = {
1260 .start = f_start,
1261 .next = f_next,
1262 .stop = f_stop,
1263 .show = f_show,
1264 };
1265
1266 static int trace_format_open(struct inode *inode, struct file *file)
1267 {
1268 struct seq_file *m;
1269 int ret;
1270
1271 ret = seq_open(file, &trace_format_seq_ops);
1272 if (ret < 0)
1273 return ret;
1274
1275 m = file->private_data;
1276 m->private = file;
1277
1278 return 0;
1279 }
1280
1281 static ssize_t
1282 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1283 {
1284 int id = (long)event_file_data(filp);
1285 char buf[32];
1286 int len;
1287
1288 if (*ppos)
1289 return 0;
1290
1291 if (unlikely(!id))
1292 return -ENODEV;
1293
1294 len = sprintf(buf, "%d\n", id);
1295
1296 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1297 }
1298
1299 static ssize_t
1300 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1301 loff_t *ppos)
1302 {
1303 struct trace_event_file *file;
1304 struct trace_seq *s;
1305 int r = -ENODEV;
1306
1307 if (*ppos)
1308 return 0;
1309
1310 s = kmalloc(sizeof(*s), GFP_KERNEL);
1311
1312 if (!s)
1313 return -ENOMEM;
1314
1315 trace_seq_init(s);
1316
1317 mutex_lock(&event_mutex);
1318 file = event_file_data(filp);
1319 if (file)
1320 print_event_filter(file, s);
1321 mutex_unlock(&event_mutex);
1322
1323 if (file)
1324 r = simple_read_from_buffer(ubuf, cnt, ppos,
1325 s->buffer, trace_seq_used(s));
1326
1327 kfree(s);
1328
1329 return r;
1330 }
1331
1332 static ssize_t
1333 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1334 loff_t *ppos)
1335 {
1336 struct trace_event_file *file;
1337 char *buf;
1338 int err = -ENODEV;
1339
1340 if (cnt >= PAGE_SIZE)
1341 return -EINVAL;
1342
1343 buf = memdup_user_nul(ubuf, cnt);
1344 if (IS_ERR(buf))
1345 return PTR_ERR(buf);
1346
1347 mutex_lock(&event_mutex);
1348 file = event_file_data(filp);
1349 if (file)
1350 err = apply_event_filter(file, buf);
1351 mutex_unlock(&event_mutex);
1352
1353 kfree(buf);
1354 if (err < 0)
1355 return err;
1356
1357 *ppos += cnt;
1358
1359 return cnt;
1360 }
1361
1362 static LIST_HEAD(event_subsystems);
1363
1364 static int subsystem_open(struct inode *inode, struct file *filp)
1365 {
1366 struct event_subsystem *system = NULL;
1367 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1368 struct trace_array *tr;
1369 int ret;
1370
1371 if (tracing_is_disabled())
1372 return -ENODEV;
1373
1374 /* Make sure the system still exists */
1375 mutex_lock(&trace_types_lock);
1376 mutex_lock(&event_mutex);
1377 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1378 list_for_each_entry(dir, &tr->systems, list) {
1379 if (dir == inode->i_private) {
1380 /* Don't open systems with no events */
1381 if (dir->nr_events) {
1382 __get_system_dir(dir);
1383 system = dir->subsystem;
1384 }
1385 goto exit_loop;
1386 }
1387 }
1388 }
1389 exit_loop:
1390 mutex_unlock(&event_mutex);
1391 mutex_unlock(&trace_types_lock);
1392
1393 if (!system)
1394 return -ENODEV;
1395
1396 /* Some versions of gcc think dir can be uninitialized here */
1397 WARN_ON(!dir);
1398
1399 /* Still need to increment the ref count of the system */
1400 if (trace_array_get(tr) < 0) {
1401 put_system(dir);
1402 return -ENODEV;
1403 }
1404
1405 ret = tracing_open_generic(inode, filp);
1406 if (ret < 0) {
1407 trace_array_put(tr);
1408 put_system(dir);
1409 }
1410
1411 return ret;
1412 }
1413
1414 static int system_tr_open(struct inode *inode, struct file *filp)
1415 {
1416 struct trace_subsystem_dir *dir;
1417 struct trace_array *tr = inode->i_private;
1418 int ret;
1419
1420 if (tracing_is_disabled())
1421 return -ENODEV;
1422
1423 if (trace_array_get(tr) < 0)
1424 return -ENODEV;
1425
1426 /* Make a temporary dir that has no system but points to tr */
1427 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1428 if (!dir) {
1429 trace_array_put(tr);
1430 return -ENOMEM;
1431 }
1432
1433 dir->tr = tr;
1434
1435 ret = tracing_open_generic(inode, filp);
1436 if (ret < 0) {
1437 trace_array_put(tr);
1438 kfree(dir);
1439 return ret;
1440 }
1441
1442 filp->private_data = dir;
1443
1444 return 0;
1445 }
1446
1447 static int subsystem_release(struct inode *inode, struct file *file)
1448 {
1449 struct trace_subsystem_dir *dir = file->private_data;
1450
1451 trace_array_put(dir->tr);
1452
1453 /*
1454 * If dir->subsystem is NULL, then this is a temporary
1455 * descriptor that was made for a trace_array to enable
1456 * all subsystems.
1457 */
1458 if (dir->subsystem)
1459 put_system(dir);
1460 else
1461 kfree(dir);
1462
1463 return 0;
1464 }
1465
1466 static ssize_t
1467 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1468 loff_t *ppos)
1469 {
1470 struct trace_subsystem_dir *dir = filp->private_data;
1471 struct event_subsystem *system = dir->subsystem;
1472 struct trace_seq *s;
1473 int r;
1474
1475 if (*ppos)
1476 return 0;
1477
1478 s = kmalloc(sizeof(*s), GFP_KERNEL);
1479 if (!s)
1480 return -ENOMEM;
1481
1482 trace_seq_init(s);
1483
1484 print_subsystem_event_filter(system, s);
1485 r = simple_read_from_buffer(ubuf, cnt, ppos,
1486 s->buffer, trace_seq_used(s));
1487
1488 kfree(s);
1489
1490 return r;
1491 }
1492
1493 static ssize_t
1494 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1495 loff_t *ppos)
1496 {
1497 struct trace_subsystem_dir *dir = filp->private_data;
1498 char *buf;
1499 int err;
1500
1501 if (cnt >= PAGE_SIZE)
1502 return -EINVAL;
1503
1504 buf = memdup_user_nul(ubuf, cnt);
1505 if (IS_ERR(buf))
1506 return PTR_ERR(buf);
1507
1508 err = apply_subsystem_event_filter(dir, buf);
1509 kfree(buf);
1510 if (err < 0)
1511 return err;
1512
1513 *ppos += cnt;
1514
1515 return cnt;
1516 }
1517
1518 static ssize_t
1519 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1520 {
1521 int (*func)(struct trace_seq *s) = filp->private_data;
1522 struct trace_seq *s;
1523 int r;
1524
1525 if (*ppos)
1526 return 0;
1527
1528 s = kmalloc(sizeof(*s), GFP_KERNEL);
1529 if (!s)
1530 return -ENOMEM;
1531
1532 trace_seq_init(s);
1533
1534 func(s);
1535 r = simple_read_from_buffer(ubuf, cnt, ppos,
1536 s->buffer, trace_seq_used(s));
1537
1538 kfree(s);
1539
1540 return r;
1541 }
1542
1543 static int max_pids(struct trace_pid_list *pid_list)
1544 {
1545 return (PAGE_SIZE << pid_list->order) / sizeof(pid_t);
1546 }
1547
1548 static void ignore_task_cpu(void *data)
1549 {
1550 struct trace_array *tr = data;
1551 struct trace_pid_list *pid_list;
1552
1553 /*
1554 * This function is called by on_each_cpu() while the
1555 * event_mutex is held.
1556 */
1557 pid_list = rcu_dereference_protected(tr->filtered_pids,
1558 mutex_is_locked(&event_mutex));
1559
1560 this_cpu_write(tr->trace_buffer.data->ignore_pid,
1561 check_ignore_pid(pid_list, current));
1562 }
1563
1564 static ssize_t
1565 ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1566 size_t cnt, loff_t *ppos)
1567 {
1568 struct seq_file *m = filp->private_data;
1569 struct trace_array *tr = m->private;
1570 struct trace_pid_list *filtered_pids = NULL;
1571 struct trace_pid_list *pid_list = NULL;
1572 struct trace_event_file *file;
1573 struct trace_parser parser;
1574 unsigned long val;
1575 loff_t this_pos;
1576 ssize_t read = 0;
1577 ssize_t ret = 0;
1578 pid_t pid;
1579 int i;
1580
1581 if (!cnt)
1582 return 0;
1583
1584 ret = tracing_update_buffers();
1585 if (ret < 0)
1586 return ret;
1587
1588 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
1589 return -ENOMEM;
1590
1591 mutex_lock(&event_mutex);
1592 /*
1593 * Load as many pids into the array before doing a
1594 * swap from the tr->filtered_pids to the new list.
1595 */
1596 while (cnt > 0) {
1597
1598 this_pos = 0;
1599
1600 ret = trace_get_user(&parser, ubuf, cnt, &this_pos);
1601 if (ret < 0 || !trace_parser_loaded(&parser))
1602 break;
1603
1604 read += ret;
1605 ubuf += ret;
1606 cnt -= ret;
1607
1608 parser.buffer[parser.idx] = 0;
1609
1610 ret = -EINVAL;
1611 if (kstrtoul(parser.buffer, 0, &val))
1612 break;
1613 if (val > INT_MAX)
1614 break;
1615
1616 pid = (pid_t)val;
1617
1618 ret = -ENOMEM;
1619 if (!pid_list) {
1620 pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL);
1621 if (!pid_list)
1622 break;
1623
1624 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1625 lockdep_is_held(&event_mutex));
1626 if (filtered_pids)
1627 pid_list->order = filtered_pids->order;
1628 else
1629 pid_list->order = 0;
1630
1631 pid_list->pids = (void *)__get_free_pages(GFP_KERNEL,
1632 pid_list->order);
1633 if (!pid_list->pids)
1634 break;
1635
1636 if (filtered_pids) {
1637 pid_list->nr_pids = filtered_pids->nr_pids;
1638 memcpy(pid_list->pids, filtered_pids->pids,
1639 pid_list->nr_pids * sizeof(pid_t));
1640 } else
1641 pid_list->nr_pids = 0;
1642 }
1643
1644 if (pid_list->nr_pids >= max_pids(pid_list)) {
1645 pid_t *pid_page;
1646
1647 pid_page = (void *)__get_free_pages(GFP_KERNEL,
1648 pid_list->order + 1);
1649 if (!pid_page)
1650 break;
1651 memcpy(pid_page, pid_list->pids,
1652 pid_list->nr_pids * sizeof(pid_t));
1653 free_pages((unsigned long)pid_list->pids, pid_list->order);
1654
1655 pid_list->order++;
1656 pid_list->pids = pid_page;
1657 }
1658
1659 pid_list->pids[pid_list->nr_pids++] = pid;
1660 trace_parser_clear(&parser);
1661 ret = 0;
1662 }
1663 trace_parser_put(&parser);
1664
1665 if (ret < 0) {
1666 if (pid_list)
1667 free_pages((unsigned long)pid_list->pids, pid_list->order);
1668 kfree(pid_list);
1669 mutex_unlock(&event_mutex);
1670 return ret;
1671 }
1672
1673 if (!pid_list) {
1674 mutex_unlock(&event_mutex);
1675 return ret;
1676 }
1677
1678 sort(pid_list->pids, pid_list->nr_pids, sizeof(pid_t), cmp_pid, NULL);
1679
1680 /* Remove duplicates */
1681 for (i = 1; i < pid_list->nr_pids; i++) {
1682 int start = i;
1683
1684 while (i < pid_list->nr_pids &&
1685 pid_list->pids[i - 1] == pid_list->pids[i])
1686 i++;
1687
1688 if (start != i) {
1689 if (i < pid_list->nr_pids) {
1690 memmove(&pid_list->pids[start], &pid_list->pids[i],
1691 (pid_list->nr_pids - i) * sizeof(pid_t));
1692 pid_list->nr_pids -= i - start;
1693 i = start;
1694 } else
1695 pid_list->nr_pids = start;
1696 }
1697 }
1698
1699 rcu_assign_pointer(tr->filtered_pids, pid_list);
1700
1701 list_for_each_entry(file, &tr->events, list) {
1702 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1703 }
1704
1705 if (filtered_pids) {
1706 synchronize_sched();
1707
1708 free_pages((unsigned long)filtered_pids->pids, filtered_pids->order);
1709 kfree(filtered_pids);
1710 } else {
1711 /*
1712 * Register a probe that is called before all other probes
1713 * to set ignore_pid if next or prev do not match.
1714 * Register a probe this is called after all other probes
1715 * to only keep ignore_pid set if next pid matches.
1716 */
1717 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1718 tr, INT_MAX);
1719 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1720 tr, 0);
1721
1722 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1723 tr, INT_MAX);
1724 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1725 tr, 0);
1726
1727 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1728 tr, INT_MAX);
1729 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1730 tr, 0);
1731
1732 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1733 tr, INT_MAX);
1734 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1735 tr, 0);
1736 }
1737
1738 /*
1739 * Ignoring of pids is done at task switch. But we have to
1740 * check for those tasks that are currently running.
1741 * Always do this in case a pid was appended or removed.
1742 */
1743 on_each_cpu(ignore_task_cpu, tr, 1);
1744
1745 mutex_unlock(&event_mutex);
1746
1747 ret = read;
1748 *ppos += read;
1749
1750 return ret;
1751 }
1752
1753 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1754 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1755 static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
1756 static int ftrace_event_release(struct inode *inode, struct file *file);
1757
1758 static const struct seq_operations show_event_seq_ops = {
1759 .start = t_start,
1760 .next = t_next,
1761 .show = t_show,
1762 .stop = t_stop,
1763 };
1764
1765 static const struct seq_operations show_set_event_seq_ops = {
1766 .start = s_start,
1767 .next = s_next,
1768 .show = t_show,
1769 .stop = t_stop,
1770 };
1771
1772 static const struct seq_operations show_set_pid_seq_ops = {
1773 .start = p_start,
1774 .next = p_next,
1775 .show = p_show,
1776 .stop = p_stop,
1777 };
1778
1779 static const struct file_operations ftrace_avail_fops = {
1780 .open = ftrace_event_avail_open,
1781 .read = seq_read,
1782 .llseek = seq_lseek,
1783 .release = seq_release,
1784 };
1785
1786 static const struct file_operations ftrace_set_event_fops = {
1787 .open = ftrace_event_set_open,
1788 .read = seq_read,
1789 .write = ftrace_event_write,
1790 .llseek = seq_lseek,
1791 .release = ftrace_event_release,
1792 };
1793
1794 static const struct file_operations ftrace_set_event_pid_fops = {
1795 .open = ftrace_event_set_pid_open,
1796 .read = seq_read,
1797 .write = ftrace_event_pid_write,
1798 .llseek = seq_lseek,
1799 .release = ftrace_event_release,
1800 };
1801
1802 static const struct file_operations ftrace_enable_fops = {
1803 .open = tracing_open_generic,
1804 .read = event_enable_read,
1805 .write = event_enable_write,
1806 .llseek = default_llseek,
1807 };
1808
1809 static const struct file_operations ftrace_event_format_fops = {
1810 .open = trace_format_open,
1811 .read = seq_read,
1812 .llseek = seq_lseek,
1813 .release = seq_release,
1814 };
1815
1816 static const struct file_operations ftrace_event_id_fops = {
1817 .read = event_id_read,
1818 .llseek = default_llseek,
1819 };
1820
1821 static const struct file_operations ftrace_event_filter_fops = {
1822 .open = tracing_open_generic,
1823 .read = event_filter_read,
1824 .write = event_filter_write,
1825 .llseek = default_llseek,
1826 };
1827
1828 static const struct file_operations ftrace_subsystem_filter_fops = {
1829 .open = subsystem_open,
1830 .read = subsystem_filter_read,
1831 .write = subsystem_filter_write,
1832 .llseek = default_llseek,
1833 .release = subsystem_release,
1834 };
1835
1836 static const struct file_operations ftrace_system_enable_fops = {
1837 .open = subsystem_open,
1838 .read = system_enable_read,
1839 .write = system_enable_write,
1840 .llseek = default_llseek,
1841 .release = subsystem_release,
1842 };
1843
1844 static const struct file_operations ftrace_tr_enable_fops = {
1845 .open = system_tr_open,
1846 .read = system_enable_read,
1847 .write = system_enable_write,
1848 .llseek = default_llseek,
1849 .release = subsystem_release,
1850 };
1851
1852 static const struct file_operations ftrace_show_header_fops = {
1853 .open = tracing_open_generic,
1854 .read = show_header,
1855 .llseek = default_llseek,
1856 };
1857
1858 static int
1859 ftrace_event_open(struct inode *inode, struct file *file,
1860 const struct seq_operations *seq_ops)
1861 {
1862 struct seq_file *m;
1863 int ret;
1864
1865 ret = seq_open(file, seq_ops);
1866 if (ret < 0)
1867 return ret;
1868 m = file->private_data;
1869 /* copy tr over to seq ops */
1870 m->private = inode->i_private;
1871
1872 return ret;
1873 }
1874
1875 static int ftrace_event_release(struct inode *inode, struct file *file)
1876 {
1877 struct trace_array *tr = inode->i_private;
1878
1879 trace_array_put(tr);
1880
1881 return seq_release(inode, file);
1882 }
1883
1884 static int
1885 ftrace_event_avail_open(struct inode *inode, struct file *file)
1886 {
1887 const struct seq_operations *seq_ops = &show_event_seq_ops;
1888
1889 return ftrace_event_open(inode, file, seq_ops);
1890 }
1891
1892 static int
1893 ftrace_event_set_open(struct inode *inode, struct file *file)
1894 {
1895 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1896 struct trace_array *tr = inode->i_private;
1897 int ret;
1898
1899 if (trace_array_get(tr) < 0)
1900 return -ENODEV;
1901
1902 if ((file->f_mode & FMODE_WRITE) &&
1903 (file->f_flags & O_TRUNC))
1904 ftrace_clear_events(tr);
1905
1906 ret = ftrace_event_open(inode, file, seq_ops);
1907 if (ret < 0)
1908 trace_array_put(tr);
1909 return ret;
1910 }
1911
1912 static int
1913 ftrace_event_set_pid_open(struct inode *inode, struct file *file)
1914 {
1915 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
1916 struct trace_array *tr = inode->i_private;
1917 int ret;
1918
1919 if (trace_array_get(tr) < 0)
1920 return -ENODEV;
1921
1922 if ((file->f_mode & FMODE_WRITE) &&
1923 (file->f_flags & O_TRUNC))
1924 ftrace_clear_event_pids(tr);
1925
1926 ret = ftrace_event_open(inode, file, seq_ops);
1927 if (ret < 0)
1928 trace_array_put(tr);
1929 return ret;
1930 }
1931
1932 static struct event_subsystem *
1933 create_new_subsystem(const char *name)
1934 {
1935 struct event_subsystem *system;
1936
1937 /* need to create new entry */
1938 system = kmalloc(sizeof(*system), GFP_KERNEL);
1939 if (!system)
1940 return NULL;
1941
1942 system->ref_count = 1;
1943
1944 /* Only allocate if dynamic (kprobes and modules) */
1945 system->name = kstrdup_const(name, GFP_KERNEL);
1946 if (!system->name)
1947 goto out_free;
1948
1949 system->filter = NULL;
1950
1951 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1952 if (!system->filter)
1953 goto out_free;
1954
1955 list_add(&system->list, &event_subsystems);
1956
1957 return system;
1958
1959 out_free:
1960 kfree_const(system->name);
1961 kfree(system);
1962 return NULL;
1963 }
1964
1965 static struct dentry *
1966 event_subsystem_dir(struct trace_array *tr, const char *name,
1967 struct trace_event_file *file, struct dentry *parent)
1968 {
1969 struct trace_subsystem_dir *dir;
1970 struct event_subsystem *system;
1971 struct dentry *entry;
1972
1973 /* First see if we did not already create this dir */
1974 list_for_each_entry(dir, &tr->systems, list) {
1975 system = dir->subsystem;
1976 if (strcmp(system->name, name) == 0) {
1977 dir->nr_events++;
1978 file->system = dir;
1979 return dir->entry;
1980 }
1981 }
1982
1983 /* Now see if the system itself exists. */
1984 list_for_each_entry(system, &event_subsystems, list) {
1985 if (strcmp(system->name, name) == 0)
1986 break;
1987 }
1988 /* Reset system variable when not found */
1989 if (&system->list == &event_subsystems)
1990 system = NULL;
1991
1992 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1993 if (!dir)
1994 goto out_fail;
1995
1996 if (!system) {
1997 system = create_new_subsystem(name);
1998 if (!system)
1999 goto out_free;
2000 } else
2001 __get_system(system);
2002
2003 dir->entry = tracefs_create_dir(name, parent);
2004 if (!dir->entry) {
2005 pr_warn("Failed to create system directory %s\n", name);
2006 __put_system(system);
2007 goto out_free;
2008 }
2009
2010 dir->tr = tr;
2011 dir->ref_count = 1;
2012 dir->nr_events = 1;
2013 dir->subsystem = system;
2014 file->system = dir;
2015
2016 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
2017 &ftrace_subsystem_filter_fops);
2018 if (!entry) {
2019 kfree(system->filter);
2020 system->filter = NULL;
2021 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
2022 }
2023
2024 trace_create_file("enable", 0644, dir->entry, dir,
2025 &ftrace_system_enable_fops);
2026
2027 list_add(&dir->list, &tr->systems);
2028
2029 return dir->entry;
2030
2031 out_free:
2032 kfree(dir);
2033 out_fail:
2034 /* Only print this message if failed on memory allocation */
2035 if (!dir || !system)
2036 pr_warn("No memory to create event subsystem %s\n", name);
2037 return NULL;
2038 }
2039
2040 static int
2041 event_create_dir(struct dentry *parent, struct trace_event_file *file)
2042 {
2043 struct trace_event_call *call = file->event_call;
2044 struct trace_array *tr = file->tr;
2045 struct list_head *head;
2046 struct dentry *d_events;
2047 const char *name;
2048 int ret;
2049
2050 /*
2051 * If the trace point header did not define TRACE_SYSTEM
2052 * then the system would be called "TRACE_SYSTEM".
2053 */
2054 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
2055 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
2056 if (!d_events)
2057 return -ENOMEM;
2058 } else
2059 d_events = parent;
2060
2061 name = trace_event_name(call);
2062 file->dir = tracefs_create_dir(name, d_events);
2063 if (!file->dir) {
2064 pr_warn("Could not create tracefs '%s' directory\n", name);
2065 return -1;
2066 }
2067
2068 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2069 trace_create_file("enable", 0644, file->dir, file,
2070 &ftrace_enable_fops);
2071
2072 #ifdef CONFIG_PERF_EVENTS
2073 if (call->event.type && call->class->reg)
2074 trace_create_file("id", 0444, file->dir,
2075 (void *)(long)call->event.type,
2076 &ftrace_event_id_fops);
2077 #endif
2078
2079 /*
2080 * Other events may have the same class. Only update
2081 * the fields if they are not already defined.
2082 */
2083 head = trace_get_fields(call);
2084 if (list_empty(head)) {
2085 ret = call->class->define_fields(call);
2086 if (ret < 0) {
2087 pr_warn("Could not initialize trace point events/%s\n",
2088 name);
2089 return -1;
2090 }
2091 }
2092 trace_create_file("filter", 0644, file->dir, file,
2093 &ftrace_event_filter_fops);
2094
2095 trace_create_file("trigger", 0644, file->dir, file,
2096 &event_trigger_fops);
2097
2098 trace_create_file("format", 0444, file->dir, call,
2099 &ftrace_event_format_fops);
2100
2101 return 0;
2102 }
2103
2104 static void remove_event_from_tracers(struct trace_event_call *call)
2105 {
2106 struct trace_event_file *file;
2107 struct trace_array *tr;
2108
2109 do_for_each_event_file_safe(tr, file) {
2110 if (file->event_call != call)
2111 continue;
2112
2113 remove_event_file_dir(file);
2114 /*
2115 * The do_for_each_event_file_safe() is
2116 * a double loop. After finding the call for this
2117 * trace_array, we use break to jump to the next
2118 * trace_array.
2119 */
2120 break;
2121 } while_for_each_event_file();
2122 }
2123
2124 static void event_remove(struct trace_event_call *call)
2125 {
2126 struct trace_array *tr;
2127 struct trace_event_file *file;
2128
2129 do_for_each_event_file(tr, file) {
2130 if (file->event_call != call)
2131 continue;
2132 ftrace_event_enable_disable(file, 0);
2133 /*
2134 * The do_for_each_event_file() is
2135 * a double loop. After finding the call for this
2136 * trace_array, we use break to jump to the next
2137 * trace_array.
2138 */
2139 break;
2140 } while_for_each_event_file();
2141
2142 if (call->event.funcs)
2143 __unregister_trace_event(&call->event);
2144 remove_event_from_tracers(call);
2145 list_del(&call->list);
2146 }
2147
2148 static int event_init(struct trace_event_call *call)
2149 {
2150 int ret = 0;
2151 const char *name;
2152
2153 name = trace_event_name(call);
2154 if (WARN_ON(!name))
2155 return -EINVAL;
2156
2157 if (call->class->raw_init) {
2158 ret = call->class->raw_init(call);
2159 if (ret < 0 && ret != -ENOSYS)
2160 pr_warn("Could not initialize trace events/%s\n", name);
2161 }
2162
2163 return ret;
2164 }
2165
2166 static int
2167 __register_event(struct trace_event_call *call, struct module *mod)
2168 {
2169 int ret;
2170
2171 ret = event_init(call);
2172 if (ret < 0)
2173 return ret;
2174
2175 list_add(&call->list, &ftrace_events);
2176 call->mod = mod;
2177
2178 return 0;
2179 }
2180
2181 static char *enum_replace(char *ptr, struct trace_enum_map *map, int len)
2182 {
2183 int rlen;
2184 int elen;
2185
2186 /* Find the length of the enum value as a string */
2187 elen = snprintf(ptr, 0, "%ld", map->enum_value);
2188 /* Make sure there's enough room to replace the string with the value */
2189 if (len < elen)
2190 return NULL;
2191
2192 snprintf(ptr, elen + 1, "%ld", map->enum_value);
2193
2194 /* Get the rest of the string of ptr */
2195 rlen = strlen(ptr + len);
2196 memmove(ptr + elen, ptr + len, rlen);
2197 /* Make sure we end the new string */
2198 ptr[elen + rlen] = 0;
2199
2200 return ptr + elen;
2201 }
2202
2203 static void update_event_printk(struct trace_event_call *call,
2204 struct trace_enum_map *map)
2205 {
2206 char *ptr;
2207 int quote = 0;
2208 int len = strlen(map->enum_string);
2209
2210 for (ptr = call->print_fmt; *ptr; ptr++) {
2211 if (*ptr == '\\') {
2212 ptr++;
2213 /* paranoid */
2214 if (!*ptr)
2215 break;
2216 continue;
2217 }
2218 if (*ptr == '"') {
2219 quote ^= 1;
2220 continue;
2221 }
2222 if (quote)
2223 continue;
2224 if (isdigit(*ptr)) {
2225 /* skip numbers */
2226 do {
2227 ptr++;
2228 /* Check for alpha chars like ULL */
2229 } while (isalnum(*ptr));
2230 if (!*ptr)
2231 break;
2232 /*
2233 * A number must have some kind of delimiter after
2234 * it, and we can ignore that too.
2235 */
2236 continue;
2237 }
2238 if (isalpha(*ptr) || *ptr == '_') {
2239 if (strncmp(map->enum_string, ptr, len) == 0 &&
2240 !isalnum(ptr[len]) && ptr[len] != '_') {
2241 ptr = enum_replace(ptr, map, len);
2242 /* Hmm, enum string smaller than value */
2243 if (WARN_ON_ONCE(!ptr))
2244 return;
2245 /*
2246 * No need to decrement here, as enum_replace()
2247 * returns the pointer to the character passed
2248 * the enum, and two enums can not be placed
2249 * back to back without something in between.
2250 * We can skip that something in between.
2251 */
2252 continue;
2253 }
2254 skip_more:
2255 do {
2256 ptr++;
2257 } while (isalnum(*ptr) || *ptr == '_');
2258 if (!*ptr)
2259 break;
2260 /*
2261 * If what comes after this variable is a '.' or
2262 * '->' then we can continue to ignore that string.
2263 */
2264 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2265 ptr += *ptr == '.' ? 1 : 2;
2266 if (!*ptr)
2267 break;
2268 goto skip_more;
2269 }
2270 /*
2271 * Once again, we can skip the delimiter that came
2272 * after the string.
2273 */
2274 continue;
2275 }
2276 }
2277 }
2278
2279 void trace_event_enum_update(struct trace_enum_map **map, int len)
2280 {
2281 struct trace_event_call *call, *p;
2282 const char *last_system = NULL;
2283 int last_i;
2284 int i;
2285
2286 down_write(&trace_event_sem);
2287 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2288 /* events are usually grouped together with systems */
2289 if (!last_system || call->class->system != last_system) {
2290 last_i = 0;
2291 last_system = call->class->system;
2292 }
2293
2294 for (i = last_i; i < len; i++) {
2295 if (call->class->system == map[i]->system) {
2296 /* Save the first system if need be */
2297 if (!last_i)
2298 last_i = i;
2299 update_event_printk(call, map[i]);
2300 }
2301 }
2302 }
2303 up_write(&trace_event_sem);
2304 }
2305
2306 static struct trace_event_file *
2307 trace_create_new_event(struct trace_event_call *call,
2308 struct trace_array *tr)
2309 {
2310 struct trace_event_file *file;
2311
2312 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2313 if (!file)
2314 return NULL;
2315
2316 file->event_call = call;
2317 file->tr = tr;
2318 atomic_set(&file->sm_ref, 0);
2319 atomic_set(&file->tm_ref, 0);
2320 INIT_LIST_HEAD(&file->triggers);
2321 list_add(&file->list, &tr->events);
2322
2323 return file;
2324 }
2325
2326 /* Add an event to a trace directory */
2327 static int
2328 __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2329 {
2330 struct trace_event_file *file;
2331
2332 file = trace_create_new_event(call, tr);
2333 if (!file)
2334 return -ENOMEM;
2335
2336 return event_create_dir(tr->event_dir, file);
2337 }
2338
2339 /*
2340 * Just create a decriptor for early init. A descriptor is required
2341 * for enabling events at boot. We want to enable events before
2342 * the filesystem is initialized.
2343 */
2344 static __init int
2345 __trace_early_add_new_event(struct trace_event_call *call,
2346 struct trace_array *tr)
2347 {
2348 struct trace_event_file *file;
2349
2350 file = trace_create_new_event(call, tr);
2351 if (!file)
2352 return -ENOMEM;
2353
2354 return 0;
2355 }
2356
2357 struct ftrace_module_file_ops;
2358 static void __add_event_to_tracers(struct trace_event_call *call);
2359
2360 /* Add an additional event_call dynamically */
2361 int trace_add_event_call(struct trace_event_call *call)
2362 {
2363 int ret;
2364 mutex_lock(&trace_types_lock);
2365 mutex_lock(&event_mutex);
2366
2367 ret = __register_event(call, NULL);
2368 if (ret >= 0)
2369 __add_event_to_tracers(call);
2370
2371 mutex_unlock(&event_mutex);
2372 mutex_unlock(&trace_types_lock);
2373 return ret;
2374 }
2375
2376 /*
2377 * Must be called under locking of trace_types_lock, event_mutex and
2378 * trace_event_sem.
2379 */
2380 static void __trace_remove_event_call(struct trace_event_call *call)
2381 {
2382 event_remove(call);
2383 trace_destroy_fields(call);
2384 free_event_filter(call->filter);
2385 call->filter = NULL;
2386 }
2387
2388 static int probe_remove_event_call(struct trace_event_call *call)
2389 {
2390 struct trace_array *tr;
2391 struct trace_event_file *file;
2392
2393 #ifdef CONFIG_PERF_EVENTS
2394 if (call->perf_refcount)
2395 return -EBUSY;
2396 #endif
2397 do_for_each_event_file(tr, file) {
2398 if (file->event_call != call)
2399 continue;
2400 /*
2401 * We can't rely on ftrace_event_enable_disable(enable => 0)
2402 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2403 * TRACE_REG_UNREGISTER.
2404 */
2405 if (file->flags & EVENT_FILE_FL_ENABLED)
2406 return -EBUSY;
2407 /*
2408 * The do_for_each_event_file_safe() is
2409 * a double loop. After finding the call for this
2410 * trace_array, we use break to jump to the next
2411 * trace_array.
2412 */
2413 break;
2414 } while_for_each_event_file();
2415
2416 __trace_remove_event_call(call);
2417
2418 return 0;
2419 }
2420
2421 /* Remove an event_call */
2422 int trace_remove_event_call(struct trace_event_call *call)
2423 {
2424 int ret;
2425
2426 mutex_lock(&trace_types_lock);
2427 mutex_lock(&event_mutex);
2428 down_write(&trace_event_sem);
2429 ret = probe_remove_event_call(call);
2430 up_write(&trace_event_sem);
2431 mutex_unlock(&event_mutex);
2432 mutex_unlock(&trace_types_lock);
2433
2434 return ret;
2435 }
2436
2437 #define for_each_event(event, start, end) \
2438 for (event = start; \
2439 (unsigned long)event < (unsigned long)end; \
2440 event++)
2441
2442 #ifdef CONFIG_MODULES
2443
2444 static void trace_module_add_events(struct module *mod)
2445 {
2446 struct trace_event_call **call, **start, **end;
2447
2448 if (!mod->num_trace_events)
2449 return;
2450
2451 /* Don't add infrastructure for mods without tracepoints */
2452 if (trace_module_has_bad_taint(mod)) {
2453 pr_err("%s: module has bad taint, not creating trace events\n",
2454 mod->name);
2455 return;
2456 }
2457
2458 start = mod->trace_events;
2459 end = mod->trace_events + mod->num_trace_events;
2460
2461 for_each_event(call, start, end) {
2462 __register_event(*call, mod);
2463 __add_event_to_tracers(*call);
2464 }
2465 }
2466
2467 static void trace_module_remove_events(struct module *mod)
2468 {
2469 struct trace_event_call *call, *p;
2470 bool clear_trace = false;
2471
2472 down_write(&trace_event_sem);
2473 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2474 if (call->mod == mod) {
2475 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
2476 clear_trace = true;
2477 __trace_remove_event_call(call);
2478 }
2479 }
2480 up_write(&trace_event_sem);
2481
2482 /*
2483 * It is safest to reset the ring buffer if the module being unloaded
2484 * registered any events that were used. The only worry is if
2485 * a new module gets loaded, and takes on the same id as the events
2486 * of this module. When printing out the buffer, traced events left
2487 * over from this module may be passed to the new module events and
2488 * unexpected results may occur.
2489 */
2490 if (clear_trace)
2491 tracing_reset_all_online_cpus();
2492 }
2493
2494 static int trace_module_notify(struct notifier_block *self,
2495 unsigned long val, void *data)
2496 {
2497 struct module *mod = data;
2498
2499 mutex_lock(&trace_types_lock);
2500 mutex_lock(&event_mutex);
2501 switch (val) {
2502 case MODULE_STATE_COMING:
2503 trace_module_add_events(mod);
2504 break;
2505 case MODULE_STATE_GOING:
2506 trace_module_remove_events(mod);
2507 break;
2508 }
2509 mutex_unlock(&event_mutex);
2510 mutex_unlock(&trace_types_lock);
2511
2512 return 0;
2513 }
2514
2515 static struct notifier_block trace_module_nb = {
2516 .notifier_call = trace_module_notify,
2517 .priority = 1, /* higher than trace.c module notify */
2518 };
2519 #endif /* CONFIG_MODULES */
2520
2521 /* Create a new event directory structure for a trace directory. */
2522 static void
2523 __trace_add_event_dirs(struct trace_array *tr)
2524 {
2525 struct trace_event_call *call;
2526 int ret;
2527
2528 list_for_each_entry(call, &ftrace_events, list) {
2529 ret = __trace_add_new_event(call, tr);
2530 if (ret < 0)
2531 pr_warn("Could not create directory for event %s\n",
2532 trace_event_name(call));
2533 }
2534 }
2535
2536 struct trace_event_file *
2537 find_event_file(struct trace_array *tr, const char *system, const char *event)
2538 {
2539 struct trace_event_file *file;
2540 struct trace_event_call *call;
2541 const char *name;
2542
2543 list_for_each_entry(file, &tr->events, list) {
2544
2545 call = file->event_call;
2546 name = trace_event_name(call);
2547
2548 if (!name || !call->class || !call->class->reg)
2549 continue;
2550
2551 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2552 continue;
2553
2554 if (strcmp(event, name) == 0 &&
2555 strcmp(system, call->class->system) == 0)
2556 return file;
2557 }
2558 return NULL;
2559 }
2560
2561 #ifdef CONFIG_DYNAMIC_FTRACE
2562
2563 /* Avoid typos */
2564 #define ENABLE_EVENT_STR "enable_event"
2565 #define DISABLE_EVENT_STR "disable_event"
2566
2567 struct event_probe_data {
2568 struct trace_event_file *file;
2569 unsigned long count;
2570 int ref;
2571 bool enable;
2572 };
2573
2574 static void
2575 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2576 {
2577 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2578 struct event_probe_data *data = *pdata;
2579
2580 if (!data)
2581 return;
2582
2583 if (data->enable)
2584 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2585 else
2586 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2587 }
2588
2589 static void
2590 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2591 {
2592 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2593 struct event_probe_data *data = *pdata;
2594
2595 if (!data)
2596 return;
2597
2598 if (!data->count)
2599 return;
2600
2601 /* Skip if the event is in a state we want to switch to */
2602 if (data->enable == !(data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
2603 return;
2604
2605 if (data->count != -1)
2606 (data->count)--;
2607
2608 event_enable_probe(ip, parent_ip, _data);
2609 }
2610
2611 static int
2612 event_enable_print(struct seq_file *m, unsigned long ip,
2613 struct ftrace_probe_ops *ops, void *_data)
2614 {
2615 struct event_probe_data *data = _data;
2616
2617 seq_printf(m, "%ps:", (void *)ip);
2618
2619 seq_printf(m, "%s:%s:%s",
2620 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2621 data->file->event_call->class->system,
2622 trace_event_name(data->file->event_call));
2623
2624 if (data->count == -1)
2625 seq_puts(m, ":unlimited\n");
2626 else
2627 seq_printf(m, ":count=%ld\n", data->count);
2628
2629 return 0;
2630 }
2631
2632 static int
2633 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
2634 void **_data)
2635 {
2636 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2637 struct event_probe_data *data = *pdata;
2638
2639 data->ref++;
2640 return 0;
2641 }
2642
2643 static void
2644 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
2645 void **_data)
2646 {
2647 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2648 struct event_probe_data *data = *pdata;
2649
2650 if (WARN_ON_ONCE(data->ref <= 0))
2651 return;
2652
2653 data->ref--;
2654 if (!data->ref) {
2655 /* Remove the SOFT_MODE flag */
2656 __ftrace_event_enable_disable(data->file, 0, 1);
2657 module_put(data->file->event_call->mod);
2658 kfree(data);
2659 }
2660 *pdata = NULL;
2661 }
2662
2663 static struct ftrace_probe_ops event_enable_probe_ops = {
2664 .func = event_enable_probe,
2665 .print = event_enable_print,
2666 .init = event_enable_init,
2667 .free = event_enable_free,
2668 };
2669
2670 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2671 .func = event_enable_count_probe,
2672 .print = event_enable_print,
2673 .init = event_enable_init,
2674 .free = event_enable_free,
2675 };
2676
2677 static struct ftrace_probe_ops event_disable_probe_ops = {
2678 .func = event_enable_probe,
2679 .print = event_enable_print,
2680 .init = event_enable_init,
2681 .free = event_enable_free,
2682 };
2683
2684 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2685 .func = event_enable_count_probe,
2686 .print = event_enable_print,
2687 .init = event_enable_init,
2688 .free = event_enable_free,
2689 };
2690
2691 static int
2692 event_enable_func(struct ftrace_hash *hash,
2693 char *glob, char *cmd, char *param, int enabled)
2694 {
2695 struct trace_array *tr = top_trace_array();
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(&param, ":");
2713 if (!param)
2714 return -EINVAL;
2715
2716 event = strsep(&param, ":");
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 unregister_ftrace_function_probe_func(glob+1, ops);
2734 ret = 0;
2735 goto out;
2736 }
2737
2738 ret = -ENOMEM;
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(&param, ":");
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 ret = register_ftrace_function_probe(glob, ops, data);
2776 /*
2777 * The above returns on success the # of functions enabled,
2778 * but if it didn't find any functions it returns zero.
2779 * Consider no functions a failure too.
2780 */
2781 if (!ret) {
2782 ret = -ENOENT;
2783 goto out_disable;
2784 } else if (ret < 0)
2785 goto out_disable;
2786 /* Just return zero, not the number of enabled functions */
2787 ret = 0;
2788 out:
2789 mutex_unlock(&event_mutex);
2790 return ret;
2791
2792 out_disable:
2793 __ftrace_event_enable_disable(file, 0, 1);
2794 out_put:
2795 module_put(file->event_call->mod);
2796 out_free:
2797 kfree(data);
2798 goto out;
2799 }
2800
2801 static struct ftrace_func_command event_enable_cmd = {
2802 .name = ENABLE_EVENT_STR,
2803 .func = event_enable_func,
2804 };
2805
2806 static struct ftrace_func_command event_disable_cmd = {
2807 .name = DISABLE_EVENT_STR,
2808 .func = event_enable_func,
2809 };
2810
2811 static __init int register_event_cmds(void)
2812 {
2813 int ret;
2814
2815 ret = register_ftrace_command(&event_enable_cmd);
2816 if (WARN_ON(ret < 0))
2817 return ret;
2818 ret = register_ftrace_command(&event_disable_cmd);
2819 if (WARN_ON(ret < 0))
2820 unregister_ftrace_command(&event_enable_cmd);
2821 return ret;
2822 }
2823 #else
2824 static inline int register_event_cmds(void) { return 0; }
2825 #endif /* CONFIG_DYNAMIC_FTRACE */
2826
2827 /*
2828 * The top level array has already had its trace_event_file
2829 * descriptors created in order to allow for early events to
2830 * be recorded. This function is called after the tracefs has been
2831 * initialized, and we now have to create the files associated
2832 * to the events.
2833 */
2834 static __init void
2835 __trace_early_add_event_dirs(struct trace_array *tr)
2836 {
2837 struct trace_event_file *file;
2838 int ret;
2839
2840
2841 list_for_each_entry(file, &tr->events, list) {
2842 ret = event_create_dir(tr->event_dir, file);
2843 if (ret < 0)
2844 pr_warn("Could not create directory for event %s\n",
2845 trace_event_name(file->event_call));
2846 }
2847 }
2848
2849 /*
2850 * For early boot up, the top trace array requires to have
2851 * a list of events that can be enabled. This must be done before
2852 * the filesystem is set up in order to allow events to be traced
2853 * early.
2854 */
2855 static __init void
2856 __trace_early_add_events(struct trace_array *tr)
2857 {
2858 struct trace_event_call *call;
2859 int ret;
2860
2861 list_for_each_entry(call, &ftrace_events, list) {
2862 /* Early boot up should not have any modules loaded */
2863 if (WARN_ON_ONCE(call->mod))
2864 continue;
2865
2866 ret = __trace_early_add_new_event(call, tr);
2867 if (ret < 0)
2868 pr_warn("Could not create early event %s\n",
2869 trace_event_name(call));
2870 }
2871 }
2872
2873 /* Remove the event directory structure for a trace directory. */
2874 static void
2875 __trace_remove_event_dirs(struct trace_array *tr)
2876 {
2877 struct trace_event_file *file, *next;
2878
2879 list_for_each_entry_safe(file, next, &tr->events, list)
2880 remove_event_file_dir(file);
2881 }
2882
2883 static void __add_event_to_tracers(struct trace_event_call *call)
2884 {
2885 struct trace_array *tr;
2886
2887 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2888 __trace_add_new_event(call, tr);
2889 }
2890
2891 extern struct trace_event_call *__start_ftrace_events[];
2892 extern struct trace_event_call *__stop_ftrace_events[];
2893
2894 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2895
2896 static __init int setup_trace_event(char *str)
2897 {
2898 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2899 ring_buffer_expanded = true;
2900 tracing_selftest_disabled = true;
2901
2902 return 1;
2903 }
2904 __setup("trace_event=", setup_trace_event);
2905
2906 /* Expects to have event_mutex held when called */
2907 static int
2908 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2909 {
2910 struct dentry *d_events;
2911 struct dentry *entry;
2912
2913 entry = tracefs_create_file("set_event", 0644, parent,
2914 tr, &ftrace_set_event_fops);
2915 if (!entry) {
2916 pr_warn("Could not create tracefs 'set_event' entry\n");
2917 return -ENOMEM;
2918 }
2919
2920 d_events = tracefs_create_dir("events", parent);
2921 if (!d_events) {
2922 pr_warn("Could not create tracefs 'events' directory\n");
2923 return -ENOMEM;
2924 }
2925
2926 entry = tracefs_create_file("set_event_pid", 0644, parent,
2927 tr, &ftrace_set_event_pid_fops);
2928
2929 /* ring buffer internal formats */
2930 trace_create_file("header_page", 0444, d_events,
2931 ring_buffer_print_page_header,
2932 &ftrace_show_header_fops);
2933
2934 trace_create_file("header_event", 0444, d_events,
2935 ring_buffer_print_entry_header,
2936 &ftrace_show_header_fops);
2937
2938 trace_create_file("enable", 0644, d_events,
2939 tr, &ftrace_tr_enable_fops);
2940
2941 tr->event_dir = d_events;
2942
2943 return 0;
2944 }
2945
2946 /**
2947 * event_trace_add_tracer - add a instance of a trace_array to events
2948 * @parent: The parent dentry to place the files/directories for events in
2949 * @tr: The trace array associated with these events
2950 *
2951 * When a new instance is created, it needs to set up its events
2952 * directory, as well as other files associated with events. It also
2953 * creates the event hierachry in the @parent/events directory.
2954 *
2955 * Returns 0 on success.
2956 */
2957 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2958 {
2959 int ret;
2960
2961 mutex_lock(&event_mutex);
2962
2963 ret = create_event_toplevel_files(parent, tr);
2964 if (ret)
2965 goto out_unlock;
2966
2967 down_write(&trace_event_sem);
2968 __trace_add_event_dirs(tr);
2969 up_write(&trace_event_sem);
2970
2971 out_unlock:
2972 mutex_unlock(&event_mutex);
2973
2974 return ret;
2975 }
2976
2977 /*
2978 * The top trace array already had its file descriptors created.
2979 * Now the files themselves need to be created.
2980 */
2981 static __init int
2982 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2983 {
2984 int ret;
2985
2986 mutex_lock(&event_mutex);
2987
2988 ret = create_event_toplevel_files(parent, tr);
2989 if (ret)
2990 goto out_unlock;
2991
2992 down_write(&trace_event_sem);
2993 __trace_early_add_event_dirs(tr);
2994 up_write(&trace_event_sem);
2995
2996 out_unlock:
2997 mutex_unlock(&event_mutex);
2998
2999 return ret;
3000 }
3001
3002 int event_trace_del_tracer(struct trace_array *tr)
3003 {
3004 mutex_lock(&event_mutex);
3005
3006 /* Disable any event triggers and associated soft-disabled events */
3007 clear_event_triggers(tr);
3008
3009 /* Clear the pid list */
3010 __ftrace_clear_event_pids(tr);
3011
3012 /* Disable any running events */
3013 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3014
3015 /* Access to events are within rcu_read_lock_sched() */
3016 synchronize_sched();
3017
3018 down_write(&trace_event_sem);
3019 __trace_remove_event_dirs(tr);
3020 tracefs_remove_recursive(tr->event_dir);
3021 up_write(&trace_event_sem);
3022
3023 tr->event_dir = NULL;
3024
3025 mutex_unlock(&event_mutex);
3026
3027 return 0;
3028 }
3029
3030 static __init int event_trace_memsetup(void)
3031 {
3032 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3033 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3034 return 0;
3035 }
3036
3037 static __init void
3038 early_enable_events(struct trace_array *tr, bool disable_first)
3039 {
3040 char *buf = bootup_event_buf;
3041 char *token;
3042 int ret;
3043
3044 while (true) {
3045 token = strsep(&buf, ",");
3046
3047 if (!token)
3048 break;
3049
3050 if (*token) {
3051 /* Restarting syscalls requires that we stop them first */
3052 if (disable_first)
3053 ftrace_set_clr_event(tr, token, 0);
3054
3055 ret = ftrace_set_clr_event(tr, token, 1);
3056 if (ret)
3057 pr_warn("Failed to enable trace event: %s\n", token);
3058 }
3059
3060 /* Put back the comma to allow this to be called again */
3061 if (buf)
3062 *(buf - 1) = ',';
3063 }
3064 }
3065
3066 static __init int event_trace_enable(void)
3067 {
3068 struct trace_array *tr = top_trace_array();
3069 struct trace_event_call **iter, *call;
3070 int ret;
3071
3072 if (!tr)
3073 return -ENODEV;
3074
3075 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3076
3077 call = *iter;
3078 ret = event_init(call);
3079 if (!ret)
3080 list_add(&call->list, &ftrace_events);
3081 }
3082
3083 /*
3084 * We need the top trace array to have a working set of trace
3085 * points at early init, before the debug files and directories
3086 * are created. Create the file entries now, and attach them
3087 * to the actual file dentries later.
3088 */
3089 __trace_early_add_events(tr);
3090
3091 early_enable_events(tr, false);
3092
3093 trace_printk_start_comm();
3094
3095 register_event_cmds();
3096
3097 register_trigger_cmds();
3098
3099 return 0;
3100 }
3101
3102 /*
3103 * event_trace_enable() is called from trace_event_init() first to
3104 * initialize events and perhaps start any events that are on the
3105 * command line. Unfortunately, there are some events that will not
3106 * start this early, like the system call tracepoints that need
3107 * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
3108 * is called before pid 1 starts, and this flag is never set, making
3109 * the syscall tracepoint never get reached, but the event is enabled
3110 * regardless (and not doing anything).
3111 */
3112 static __init int event_trace_enable_again(void)
3113 {
3114 struct trace_array *tr;
3115
3116 tr = top_trace_array();
3117 if (!tr)
3118 return -ENODEV;
3119
3120 early_enable_events(tr, true);
3121
3122 return 0;
3123 }
3124
3125 early_initcall(event_trace_enable_again);
3126
3127 static __init int event_trace_init(void)
3128 {
3129 struct trace_array *tr;
3130 struct dentry *d_tracer;
3131 struct dentry *entry;
3132 int ret;
3133
3134 tr = top_trace_array();
3135 if (!tr)
3136 return -ENODEV;
3137
3138 d_tracer = tracing_init_dentry();
3139 if (IS_ERR(d_tracer))
3140 return 0;
3141
3142 entry = tracefs_create_file("available_events", 0444, d_tracer,
3143 tr, &ftrace_avail_fops);
3144 if (!entry)
3145 pr_warn("Could not create tracefs 'available_events' entry\n");
3146
3147 if (trace_define_generic_fields())
3148 pr_warn("tracing: Failed to allocated generic fields");
3149
3150 if (trace_define_common_fields())
3151 pr_warn("tracing: Failed to allocate common fields");
3152
3153 ret = early_event_add_tracer(d_tracer, tr);
3154 if (ret)
3155 return ret;
3156
3157 #ifdef CONFIG_MODULES
3158 ret = register_module_notifier(&trace_module_nb);
3159 if (ret)
3160 pr_warn("Failed to register trace events module notifier\n");
3161 #endif
3162 return 0;
3163 }
3164
3165 void __init trace_event_init(void)
3166 {
3167 event_trace_memsetup();
3168 init_ftrace_syscalls();
3169 event_trace_enable();
3170 }
3171
3172 fs_initcall(event_trace_init);
3173
3174 #ifdef CONFIG_FTRACE_STARTUP_TEST
3175
3176 static DEFINE_SPINLOCK(test_spinlock);
3177 static DEFINE_SPINLOCK(test_spinlock_irq);
3178 static DEFINE_MUTEX(test_mutex);
3179
3180 static __init void test_work(struct work_struct *dummy)
3181 {
3182 spin_lock(&test_spinlock);
3183 spin_lock_irq(&test_spinlock_irq);
3184 udelay(1);
3185 spin_unlock_irq(&test_spinlock_irq);
3186 spin_unlock(&test_spinlock);
3187
3188 mutex_lock(&test_mutex);
3189 msleep(1);
3190 mutex_unlock(&test_mutex);
3191 }
3192
3193 static __init int event_test_thread(void *unused)
3194 {
3195 void *test_malloc;
3196
3197 test_malloc = kmalloc(1234, GFP_KERNEL);
3198 if (!test_malloc)
3199 pr_info("failed to kmalloc\n");
3200
3201 schedule_on_each_cpu(test_work);
3202
3203 kfree(test_malloc);
3204
3205 set_current_state(TASK_INTERRUPTIBLE);
3206 while (!kthread_should_stop()) {
3207 schedule();
3208 set_current_state(TASK_INTERRUPTIBLE);
3209 }
3210 __set_current_state(TASK_RUNNING);
3211
3212 return 0;
3213 }
3214
3215 /*
3216 * Do various things that may trigger events.
3217 */
3218 static __init void event_test_stuff(void)
3219 {
3220 struct task_struct *test_thread;
3221
3222 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3223 msleep(1);
3224 kthread_stop(test_thread);
3225 }
3226
3227 /*
3228 * For every trace event defined, we will test each trace point separately,
3229 * and then by groups, and finally all trace points.
3230 */
3231 static __init void event_trace_self_tests(void)
3232 {
3233 struct trace_subsystem_dir *dir;
3234 struct trace_event_file *file;
3235 struct trace_event_call *call;
3236 struct event_subsystem *system;
3237 struct trace_array *tr;
3238 int ret;
3239
3240 tr = top_trace_array();
3241 if (!tr)
3242 return;
3243
3244 pr_info("Running tests on trace events:\n");
3245
3246 list_for_each_entry(file, &tr->events, list) {
3247
3248 call = file->event_call;
3249
3250 /* Only test those that have a probe */
3251 if (!call->class || !call->class->probe)
3252 continue;
3253
3254 /*
3255 * Testing syscall events here is pretty useless, but
3256 * we still do it if configured. But this is time consuming.
3257 * What we really need is a user thread to perform the
3258 * syscalls as we test.
3259 */
3260 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3261 if (call->class->system &&
3262 strcmp(call->class->system, "syscalls") == 0)
3263 continue;
3264 #endif
3265
3266 pr_info("Testing event %s: ", trace_event_name(call));
3267
3268 /*
3269 * If an event is already enabled, someone is using
3270 * it and the self test should not be on.
3271 */
3272 if (file->flags & EVENT_FILE_FL_ENABLED) {
3273 pr_warn("Enabled event during self test!\n");
3274 WARN_ON_ONCE(1);
3275 continue;
3276 }
3277
3278 ftrace_event_enable_disable(file, 1);
3279 event_test_stuff();
3280 ftrace_event_enable_disable(file, 0);
3281
3282 pr_cont("OK\n");
3283 }
3284
3285 /* Now test at the sub system level */
3286
3287 pr_info("Running tests on trace event systems:\n");
3288
3289 list_for_each_entry(dir, &tr->systems, list) {
3290
3291 system = dir->subsystem;
3292
3293 /* the ftrace system is special, skip it */
3294 if (strcmp(system->name, "ftrace") == 0)
3295 continue;
3296
3297 pr_info("Testing event system %s: ", system->name);
3298
3299 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3300 if (WARN_ON_ONCE(ret)) {
3301 pr_warn("error enabling system %s\n",
3302 system->name);
3303 continue;
3304 }
3305
3306 event_test_stuff();
3307
3308 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3309 if (WARN_ON_ONCE(ret)) {
3310 pr_warn("error disabling system %s\n",
3311 system->name);
3312 continue;
3313 }
3314
3315 pr_cont("OK\n");
3316 }
3317
3318 /* Test with all events enabled */
3319
3320 pr_info("Running tests on all trace events:\n");
3321 pr_info("Testing all events: ");
3322
3323 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3324 if (WARN_ON_ONCE(ret)) {
3325 pr_warn("error enabling all events\n");
3326 return;
3327 }
3328
3329 event_test_stuff();
3330
3331 /* reset sysname */
3332 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3333 if (WARN_ON_ONCE(ret)) {
3334 pr_warn("error disabling all events\n");
3335 return;
3336 }
3337
3338 pr_cont("OK\n");
3339 }
3340
3341 #ifdef CONFIG_FUNCTION_TRACER
3342
3343 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3344
3345 static struct trace_array *event_tr;
3346
3347 static void __init
3348 function_test_events_call(unsigned long ip, unsigned long parent_ip,
3349 struct ftrace_ops *op, struct pt_regs *pt_regs)
3350 {
3351 struct ring_buffer_event *event;
3352 struct ring_buffer *buffer;
3353 struct ftrace_entry *entry;
3354 unsigned long flags;
3355 long disabled;
3356 int cpu;
3357 int pc;
3358
3359 pc = preempt_count();
3360 preempt_disable_notrace();
3361 cpu = raw_smp_processor_id();
3362 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3363
3364 if (disabled != 1)
3365 goto out;
3366
3367 local_save_flags(flags);
3368
3369 event = trace_current_buffer_lock_reserve(&buffer,
3370 TRACE_FN, sizeof(*entry),
3371 flags, pc);
3372 if (!event)
3373 goto out;
3374 entry = ring_buffer_event_data(event);
3375 entry->ip = ip;
3376 entry->parent_ip = parent_ip;
3377
3378 trace_buffer_unlock_commit(event_tr, buffer, event, flags, pc);
3379
3380 out:
3381 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3382 preempt_enable_notrace();
3383 }
3384
3385 static struct ftrace_ops trace_ops __initdata =
3386 {
3387 .func = function_test_events_call,
3388 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
3389 };
3390
3391 static __init void event_trace_self_test_with_function(void)
3392 {
3393 int ret;
3394 event_tr = top_trace_array();
3395 if (WARN_ON(!event_tr))
3396 return;
3397 ret = register_ftrace_function(&trace_ops);
3398 if (WARN_ON(ret < 0)) {
3399 pr_info("Failed to enable function tracer for event tests\n");
3400 return;
3401 }
3402 pr_info("Running tests again, along with the function tracer\n");
3403 event_trace_self_tests();
3404 unregister_ftrace_function(&trace_ops);
3405 }
3406 #else
3407 static __init void event_trace_self_test_with_function(void)
3408 {
3409 }
3410 #endif
3411
3412 static __init int event_trace_self_tests_init(void)
3413 {
3414 if (!tracing_selftest_disabled) {
3415 event_trace_self_tests();
3416 event_trace_self_test_with_function();
3417 }
3418
3419 return 0;
3420 }
3421
3422 late_initcall(event_trace_self_tests_init);
3423
3424 #endif
Linux with added FPC-III support