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irqdomain: Allow domain lookup with DOMAIN_BUS_WIRED token
[linux/fpc-iii.git] / kernel / trace / trace_events.c
blob4f6ef6912e00173040867f6a68c52f010bbfd21d
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 = (char *)__get_free_page(GFP_TEMPORARY);
1344 if (!buf)
1345 return -ENOMEM;
1346
1347 if (copy_from_user(buf, ubuf, cnt)) {
1348 free_page((unsigned long) buf);
1349 return -EFAULT;
1350 }
1351 buf[cnt] = '\0';
1352
1353 mutex_lock(&event_mutex);
1354 file = event_file_data(filp);
1355 if (file)
1356 err = apply_event_filter(file, buf);
1357 mutex_unlock(&event_mutex);
1358
1359 free_page((unsigned long) buf);
1360 if (err < 0)
1361 return err;
1362
1363 *ppos += cnt;
1364
1365 return cnt;
1366 }
1367
1368 static LIST_HEAD(event_subsystems);
1369
1370 static int subsystem_open(struct inode *inode, struct file *filp)
1371 {
1372 struct event_subsystem *system = NULL;
1373 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1374 struct trace_array *tr;
1375 int ret;
1376
1377 if (tracing_is_disabled())
1378 return -ENODEV;
1379
1380 /* Make sure the system still exists */
1381 mutex_lock(&trace_types_lock);
1382 mutex_lock(&event_mutex);
1383 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1384 list_for_each_entry(dir, &tr->systems, list) {
1385 if (dir == inode->i_private) {
1386 /* Don't open systems with no events */
1387 if (dir->nr_events) {
1388 __get_system_dir(dir);
1389 system = dir->subsystem;
1390 }
1391 goto exit_loop;
1392 }
1393 }
1394 }
1395 exit_loop:
1396 mutex_unlock(&event_mutex);
1397 mutex_unlock(&trace_types_lock);
1398
1399 if (!system)
1400 return -ENODEV;
1401
1402 /* Some versions of gcc think dir can be uninitialized here */
1403 WARN_ON(!dir);
1404
1405 /* Still need to increment the ref count of the system */
1406 if (trace_array_get(tr) < 0) {
1407 put_system(dir);
1408 return -ENODEV;
1409 }
1410
1411 ret = tracing_open_generic(inode, filp);
1412 if (ret < 0) {
1413 trace_array_put(tr);
1414 put_system(dir);
1415 }
1416
1417 return ret;
1418 }
1419
1420 static int system_tr_open(struct inode *inode, struct file *filp)
1421 {
1422 struct trace_subsystem_dir *dir;
1423 struct trace_array *tr = inode->i_private;
1424 int ret;
1425
1426 if (tracing_is_disabled())
1427 return -ENODEV;
1428
1429 if (trace_array_get(tr) < 0)
1430 return -ENODEV;
1431
1432 /* Make a temporary dir that has no system but points to tr */
1433 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1434 if (!dir) {
1435 trace_array_put(tr);
1436 return -ENOMEM;
1437 }
1438
1439 dir->tr = tr;
1440
1441 ret = tracing_open_generic(inode, filp);
1442 if (ret < 0) {
1443 trace_array_put(tr);
1444 kfree(dir);
1445 return ret;
1446 }
1447
1448 filp->private_data = dir;
1449
1450 return 0;
1451 }
1452
1453 static int subsystem_release(struct inode *inode, struct file *file)
1454 {
1455 struct trace_subsystem_dir *dir = file->private_data;
1456
1457 trace_array_put(dir->tr);
1458
1459 /*
1460 * If dir->subsystem is NULL, then this is a temporary
1461 * descriptor that was made for a trace_array to enable
1462 * all subsystems.
1463 */
1464 if (dir->subsystem)
1465 put_system(dir);
1466 else
1467 kfree(dir);
1468
1469 return 0;
1470 }
1471
1472 static ssize_t
1473 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1474 loff_t *ppos)
1475 {
1476 struct trace_subsystem_dir *dir = filp->private_data;
1477 struct event_subsystem *system = dir->subsystem;
1478 struct trace_seq *s;
1479 int r;
1480
1481 if (*ppos)
1482 return 0;
1483
1484 s = kmalloc(sizeof(*s), GFP_KERNEL);
1485 if (!s)
1486 return -ENOMEM;
1487
1488 trace_seq_init(s);
1489
1490 print_subsystem_event_filter(system, s);
1491 r = simple_read_from_buffer(ubuf, cnt, ppos,
1492 s->buffer, trace_seq_used(s));
1493
1494 kfree(s);
1495
1496 return r;
1497 }
1498
1499 static ssize_t
1500 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1501 loff_t *ppos)
1502 {
1503 struct trace_subsystem_dir *dir = filp->private_data;
1504 char *buf;
1505 int err;
1506
1507 if (cnt >= PAGE_SIZE)
1508 return -EINVAL;
1509
1510 buf = (char *)__get_free_page(GFP_TEMPORARY);
1511 if (!buf)
1512 return -ENOMEM;
1513
1514 if (copy_from_user(buf, ubuf, cnt)) {
1515 free_page((unsigned long) buf);
1516 return -EFAULT;
1517 }
1518 buf[cnt] = '\0';
1519
1520 err = apply_subsystem_event_filter(dir, buf);
1521 free_page((unsigned long) buf);
1522 if (err < 0)
1523 return err;
1524
1525 *ppos += cnt;
1526
1527 return cnt;
1528 }
1529
1530 static ssize_t
1531 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1532 {
1533 int (*func)(struct trace_seq *s) = filp->private_data;
1534 struct trace_seq *s;
1535 int r;
1536
1537 if (*ppos)
1538 return 0;
1539
1540 s = kmalloc(sizeof(*s), GFP_KERNEL);
1541 if (!s)
1542 return -ENOMEM;
1543
1544 trace_seq_init(s);
1545
1546 func(s);
1547 r = simple_read_from_buffer(ubuf, cnt, ppos,
1548 s->buffer, trace_seq_used(s));
1549
1550 kfree(s);
1551
1552 return r;
1553 }
1554
1555 static int max_pids(struct trace_pid_list *pid_list)
1556 {
1557 return (PAGE_SIZE << pid_list->order) / sizeof(pid_t);
1558 }
1559
1560 static void ignore_task_cpu(void *data)
1561 {
1562 struct trace_array *tr = data;
1563 struct trace_pid_list *pid_list;
1564
1565 /*
1566 * This function is called by on_each_cpu() while the
1567 * event_mutex is held.
1568 */
1569 pid_list = rcu_dereference_protected(tr->filtered_pids,
1570 mutex_is_locked(&event_mutex));
1571
1572 this_cpu_write(tr->trace_buffer.data->ignore_pid,
1573 check_ignore_pid(pid_list, current));
1574 }
1575
1576 static ssize_t
1577 ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1578 size_t cnt, loff_t *ppos)
1579 {
1580 struct seq_file *m = filp->private_data;
1581 struct trace_array *tr = m->private;
1582 struct trace_pid_list *filtered_pids = NULL;
1583 struct trace_pid_list *pid_list = NULL;
1584 struct trace_event_file *file;
1585 struct trace_parser parser;
1586 unsigned long val;
1587 loff_t this_pos;
1588 ssize_t read = 0;
1589 ssize_t ret = 0;
1590 pid_t pid;
1591 int i;
1592
1593 if (!cnt)
1594 return 0;
1595
1596 ret = tracing_update_buffers();
1597 if (ret < 0)
1598 return ret;
1599
1600 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
1601 return -ENOMEM;
1602
1603 mutex_lock(&event_mutex);
1604 /*
1605 * Load as many pids into the array before doing a
1606 * swap from the tr->filtered_pids to the new list.
1607 */
1608 while (cnt > 0) {
1609
1610 this_pos = 0;
1611
1612 ret = trace_get_user(&parser, ubuf, cnt, &this_pos);
1613 if (ret < 0 || !trace_parser_loaded(&parser))
1614 break;
1615
1616 read += ret;
1617 ubuf += ret;
1618 cnt -= ret;
1619
1620 parser.buffer[parser.idx] = 0;
1621
1622 ret = -EINVAL;
1623 if (kstrtoul(parser.buffer, 0, &val))
1624 break;
1625 if (val > INT_MAX)
1626 break;
1627
1628 pid = (pid_t)val;
1629
1630 ret = -ENOMEM;
1631 if (!pid_list) {
1632 pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL);
1633 if (!pid_list)
1634 break;
1635
1636 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1637 lockdep_is_held(&event_mutex));
1638 if (filtered_pids)
1639 pid_list->order = filtered_pids->order;
1640 else
1641 pid_list->order = 0;
1642
1643 pid_list->pids = (void *)__get_free_pages(GFP_KERNEL,
1644 pid_list->order);
1645 if (!pid_list->pids)
1646 break;
1647
1648 if (filtered_pids) {
1649 pid_list->nr_pids = filtered_pids->nr_pids;
1650 memcpy(pid_list->pids, filtered_pids->pids,
1651 pid_list->nr_pids * sizeof(pid_t));
1652 } else
1653 pid_list->nr_pids = 0;
1654 }
1655
1656 if (pid_list->nr_pids >= max_pids(pid_list)) {
1657 pid_t *pid_page;
1658
1659 pid_page = (void *)__get_free_pages(GFP_KERNEL,
1660 pid_list->order + 1);
1661 if (!pid_page)
1662 break;
1663 memcpy(pid_page, pid_list->pids,
1664 pid_list->nr_pids * sizeof(pid_t));
1665 free_pages((unsigned long)pid_list->pids, pid_list->order);
1666
1667 pid_list->order++;
1668 pid_list->pids = pid_page;
1669 }
1670
1671 pid_list->pids[pid_list->nr_pids++] = pid;
1672 trace_parser_clear(&parser);
1673 ret = 0;
1674 }
1675 trace_parser_put(&parser);
1676
1677 if (ret < 0) {
1678 if (pid_list)
1679 free_pages((unsigned long)pid_list->pids, pid_list->order);
1680 kfree(pid_list);
1681 mutex_unlock(&event_mutex);
1682 return ret;
1683 }
1684
1685 if (!pid_list) {
1686 mutex_unlock(&event_mutex);
1687 return ret;
1688 }
1689
1690 sort(pid_list->pids, pid_list->nr_pids, sizeof(pid_t), cmp_pid, NULL);
1691
1692 /* Remove duplicates */
1693 for (i = 1; i < pid_list->nr_pids; i++) {
1694 int start = i;
1695
1696 while (i < pid_list->nr_pids &&
1697 pid_list->pids[i - 1] == pid_list->pids[i])
1698 i++;
1699
1700 if (start != i) {
1701 if (i < pid_list->nr_pids) {
1702 memmove(&pid_list->pids[start], &pid_list->pids[i],
1703 (pid_list->nr_pids - i) * sizeof(pid_t));
1704 pid_list->nr_pids -= i - start;
1705 i = start;
1706 } else
1707 pid_list->nr_pids = start;
1708 }
1709 }
1710
1711 rcu_assign_pointer(tr->filtered_pids, pid_list);
1712
1713 list_for_each_entry(file, &tr->events, list) {
1714 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1715 }
1716
1717 if (filtered_pids) {
1718 synchronize_sched();
1719
1720 free_pages((unsigned long)filtered_pids->pids, filtered_pids->order);
1721 kfree(filtered_pids);
1722 } else {
1723 /*
1724 * Register a probe that is called before all other probes
1725 * to set ignore_pid if next or prev do not match.
1726 * Register a probe this is called after all other probes
1727 * to only keep ignore_pid set if next pid matches.
1728 */
1729 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1730 tr, INT_MAX);
1731 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1732 tr, 0);
1733
1734 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1735 tr, INT_MAX);
1736 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1737 tr, 0);
1738
1739 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1740 tr, INT_MAX);
1741 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1742 tr, 0);
1743
1744 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1745 tr, INT_MAX);
1746 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1747 tr, 0);
1748 }
1749
1750 /*
1751 * Ignoring of pids is done at task switch. But we have to
1752 * check for those tasks that are currently running.
1753 * Always do this in case a pid was appended or removed.
1754 */
1755 on_each_cpu(ignore_task_cpu, tr, 1);
1756
1757 mutex_unlock(&event_mutex);
1758
1759 ret = read;
1760 *ppos += read;
1761
1762 return ret;
1763 }
1764
1765 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1766 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1767 static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
1768 static int ftrace_event_release(struct inode *inode, struct file *file);
1769
1770 static const struct seq_operations show_event_seq_ops = {
1771 .start = t_start,
1772 .next = t_next,
1773 .show = t_show,
1774 .stop = t_stop,
1775 };
1776
1777 static const struct seq_operations show_set_event_seq_ops = {
1778 .start = s_start,
1779 .next = s_next,
1780 .show = t_show,
1781 .stop = t_stop,
1782 };
1783
1784 static const struct seq_operations show_set_pid_seq_ops = {
1785 .start = p_start,
1786 .next = p_next,
1787 .show = p_show,
1788 .stop = p_stop,
1789 };
1790
1791 static const struct file_operations ftrace_avail_fops = {
1792 .open = ftrace_event_avail_open,
1793 .read = seq_read,
1794 .llseek = seq_lseek,
1795 .release = seq_release,
1796 };
1797
1798 static const struct file_operations ftrace_set_event_fops = {
1799 .open = ftrace_event_set_open,
1800 .read = seq_read,
1801 .write = ftrace_event_write,
1802 .llseek = seq_lseek,
1803 .release = ftrace_event_release,
1804 };
1805
1806 static const struct file_operations ftrace_set_event_pid_fops = {
1807 .open = ftrace_event_set_pid_open,
1808 .read = seq_read,
1809 .write = ftrace_event_pid_write,
1810 .llseek = seq_lseek,
1811 .release = ftrace_event_release,
1812 };
1813
1814 static const struct file_operations ftrace_enable_fops = {
1815 .open = tracing_open_generic,
1816 .read = event_enable_read,
1817 .write = event_enable_write,
1818 .llseek = default_llseek,
1819 };
1820
1821 static const struct file_operations ftrace_event_format_fops = {
1822 .open = trace_format_open,
1823 .read = seq_read,
1824 .llseek = seq_lseek,
1825 .release = seq_release,
1826 };
1827
1828 static const struct file_operations ftrace_event_id_fops = {
1829 .read = event_id_read,
1830 .llseek = default_llseek,
1831 };
1832
1833 static const struct file_operations ftrace_event_filter_fops = {
1834 .open = tracing_open_generic,
1835 .read = event_filter_read,
1836 .write = event_filter_write,
1837 .llseek = default_llseek,
1838 };
1839
1840 static const struct file_operations ftrace_subsystem_filter_fops = {
1841 .open = subsystem_open,
1842 .read = subsystem_filter_read,
1843 .write = subsystem_filter_write,
1844 .llseek = default_llseek,
1845 .release = subsystem_release,
1846 };
1847
1848 static const struct file_operations ftrace_system_enable_fops = {
1849 .open = subsystem_open,
1850 .read = system_enable_read,
1851 .write = system_enable_write,
1852 .llseek = default_llseek,
1853 .release = subsystem_release,
1854 };
1855
1856 static const struct file_operations ftrace_tr_enable_fops = {
1857 .open = system_tr_open,
1858 .read = system_enable_read,
1859 .write = system_enable_write,
1860 .llseek = default_llseek,
1861 .release = subsystem_release,
1862 };
1863
1864 static const struct file_operations ftrace_show_header_fops = {
1865 .open = tracing_open_generic,
1866 .read = show_header,
1867 .llseek = default_llseek,
1868 };
1869
1870 static int
1871 ftrace_event_open(struct inode *inode, struct file *file,
1872 const struct seq_operations *seq_ops)
1873 {
1874 struct seq_file *m;
1875 int ret;
1876
1877 ret = seq_open(file, seq_ops);
1878 if (ret < 0)
1879 return ret;
1880 m = file->private_data;
1881 /* copy tr over to seq ops */
1882 m->private = inode->i_private;
1883
1884 return ret;
1885 }
1886
1887 static int ftrace_event_release(struct inode *inode, struct file *file)
1888 {
1889 struct trace_array *tr = inode->i_private;
1890
1891 trace_array_put(tr);
1892
1893 return seq_release(inode, file);
1894 }
1895
1896 static int
1897 ftrace_event_avail_open(struct inode *inode, struct file *file)
1898 {
1899 const struct seq_operations *seq_ops = &show_event_seq_ops;
1900
1901 return ftrace_event_open(inode, file, seq_ops);
1902 }
1903
1904 static int
1905 ftrace_event_set_open(struct inode *inode, struct file *file)
1906 {
1907 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1908 struct trace_array *tr = inode->i_private;
1909 int ret;
1910
1911 if (trace_array_get(tr) < 0)
1912 return -ENODEV;
1913
1914 if ((file->f_mode & FMODE_WRITE) &&
1915 (file->f_flags & O_TRUNC))
1916 ftrace_clear_events(tr);
1917
1918 ret = ftrace_event_open(inode, file, seq_ops);
1919 if (ret < 0)
1920 trace_array_put(tr);
1921 return ret;
1922 }
1923
1924 static int
1925 ftrace_event_set_pid_open(struct inode *inode, struct file *file)
1926 {
1927 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
1928 struct trace_array *tr = inode->i_private;
1929 int ret;
1930
1931 if (trace_array_get(tr) < 0)
1932 return -ENODEV;
1933
1934 if ((file->f_mode & FMODE_WRITE) &&
1935 (file->f_flags & O_TRUNC))
1936 ftrace_clear_event_pids(tr);
1937
1938 ret = ftrace_event_open(inode, file, seq_ops);
1939 if (ret < 0)
1940 trace_array_put(tr);
1941 return ret;
1942 }
1943
1944 static struct event_subsystem *
1945 create_new_subsystem(const char *name)
1946 {
1947 struct event_subsystem *system;
1948
1949 /* need to create new entry */
1950 system = kmalloc(sizeof(*system), GFP_KERNEL);
1951 if (!system)
1952 return NULL;
1953
1954 system->ref_count = 1;
1955
1956 /* Only allocate if dynamic (kprobes and modules) */
1957 system->name = kstrdup_const(name, GFP_KERNEL);
1958 if (!system->name)
1959 goto out_free;
1960
1961 system->filter = NULL;
1962
1963 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1964 if (!system->filter)
1965 goto out_free;
1966
1967 list_add(&system->list, &event_subsystems);
1968
1969 return system;
1970
1971 out_free:
1972 kfree_const(system->name);
1973 kfree(system);
1974 return NULL;
1975 }
1976
1977 static struct dentry *
1978 event_subsystem_dir(struct trace_array *tr, const char *name,
1979 struct trace_event_file *file, struct dentry *parent)
1980 {
1981 struct trace_subsystem_dir *dir;
1982 struct event_subsystem *system;
1983 struct dentry *entry;
1984
1985 /* First see if we did not already create this dir */
1986 list_for_each_entry(dir, &tr->systems, list) {
1987 system = dir->subsystem;
1988 if (strcmp(system->name, name) == 0) {
1989 dir->nr_events++;
1990 file->system = dir;
1991 return dir->entry;
1992 }
1993 }
1994
1995 /* Now see if the system itself exists. */
1996 list_for_each_entry(system, &event_subsystems, list) {
1997 if (strcmp(system->name, name) == 0)
1998 break;
1999 }
2000 /* Reset system variable when not found */
2001 if (&system->list == &event_subsystems)
2002 system = NULL;
2003
2004 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
2005 if (!dir)
2006 goto out_fail;
2007
2008 if (!system) {
2009 system = create_new_subsystem(name);
2010 if (!system)
2011 goto out_free;
2012 } else
2013 __get_system(system);
2014
2015 dir->entry = tracefs_create_dir(name, parent);
2016 if (!dir->entry) {
2017 pr_warn("Failed to create system directory %s\n", name);
2018 __put_system(system);
2019 goto out_free;
2020 }
2021
2022 dir->tr = tr;
2023 dir->ref_count = 1;
2024 dir->nr_events = 1;
2025 dir->subsystem = system;
2026 file->system = dir;
2027
2028 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
2029 &ftrace_subsystem_filter_fops);
2030 if (!entry) {
2031 kfree(system->filter);
2032 system->filter = NULL;
2033 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
2034 }
2035
2036 trace_create_file("enable", 0644, dir->entry, dir,
2037 &ftrace_system_enable_fops);
2038
2039 list_add(&dir->list, &tr->systems);
2040
2041 return dir->entry;
2042
2043 out_free:
2044 kfree(dir);
2045 out_fail:
2046 /* Only print this message if failed on memory allocation */
2047 if (!dir || !system)
2048 pr_warn("No memory to create event subsystem %s\n", name);
2049 return NULL;
2050 }
2051
2052 static int
2053 event_create_dir(struct dentry *parent, struct trace_event_file *file)
2054 {
2055 struct trace_event_call *call = file->event_call;
2056 struct trace_array *tr = file->tr;
2057 struct list_head *head;
2058 struct dentry *d_events;
2059 const char *name;
2060 int ret;
2061
2062 /*
2063 * If the trace point header did not define TRACE_SYSTEM
2064 * then the system would be called "TRACE_SYSTEM".
2065 */
2066 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
2067 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
2068 if (!d_events)
2069 return -ENOMEM;
2070 } else
2071 d_events = parent;
2072
2073 name = trace_event_name(call);
2074 file->dir = tracefs_create_dir(name, d_events);
2075 if (!file->dir) {
2076 pr_warn("Could not create tracefs '%s' directory\n", name);
2077 return -1;
2078 }
2079
2080 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2081 trace_create_file("enable", 0644, file->dir, file,
2082 &ftrace_enable_fops);
2083
2084 #ifdef CONFIG_PERF_EVENTS
2085 if (call->event.type && call->class->reg)
2086 trace_create_file("id", 0444, file->dir,
2087 (void *)(long)call->event.type,
2088 &ftrace_event_id_fops);
2089 #endif
2090
2091 /*
2092 * Other events may have the same class. Only update
2093 * the fields if they are not already defined.
2094 */
2095 head = trace_get_fields(call);
2096 if (list_empty(head)) {
2097 ret = call->class->define_fields(call);
2098 if (ret < 0) {
2099 pr_warn("Could not initialize trace point events/%s\n",
2100 name);
2101 return -1;
2102 }
2103 }
2104 trace_create_file("filter", 0644, file->dir, file,
2105 &ftrace_event_filter_fops);
2106
2107 trace_create_file("trigger", 0644, file->dir, file,
2108 &event_trigger_fops);
2109
2110 trace_create_file("format", 0444, file->dir, call,
2111 &ftrace_event_format_fops);
2112
2113 return 0;
2114 }
2115
2116 static void remove_event_from_tracers(struct trace_event_call *call)
2117 {
2118 struct trace_event_file *file;
2119 struct trace_array *tr;
2120
2121 do_for_each_event_file_safe(tr, file) {
2122 if (file->event_call != call)
2123 continue;
2124
2125 remove_event_file_dir(file);
2126 /*
2127 * The do_for_each_event_file_safe() is
2128 * a double loop. After finding the call for this
2129 * trace_array, we use break to jump to the next
2130 * trace_array.
2131 */
2132 break;
2133 } while_for_each_event_file();
2134 }
2135
2136 static void event_remove(struct trace_event_call *call)
2137 {
2138 struct trace_array *tr;
2139 struct trace_event_file *file;
2140
2141 do_for_each_event_file(tr, file) {
2142 if (file->event_call != call)
2143 continue;
2144 ftrace_event_enable_disable(file, 0);
2145 /*
2146 * The do_for_each_event_file() is
2147 * a double loop. After finding the call for this
2148 * trace_array, we use break to jump to the next
2149 * trace_array.
2150 */
2151 break;
2152 } while_for_each_event_file();
2153
2154 if (call->event.funcs)
2155 __unregister_trace_event(&call->event);
2156 remove_event_from_tracers(call);
2157 list_del(&call->list);
2158 }
2159
2160 static int event_init(struct trace_event_call *call)
2161 {
2162 int ret = 0;
2163 const char *name;
2164
2165 name = trace_event_name(call);
2166 if (WARN_ON(!name))
2167 return -EINVAL;
2168
2169 if (call->class->raw_init) {
2170 ret = call->class->raw_init(call);
2171 if (ret < 0 && ret != -ENOSYS)
2172 pr_warn("Could not initialize trace events/%s\n", name);
2173 }
2174
2175 return ret;
2176 }
2177
2178 static int
2179 __register_event(struct trace_event_call *call, struct module *mod)
2180 {
2181 int ret;
2182
2183 ret = event_init(call);
2184 if (ret < 0)
2185 return ret;
2186
2187 list_add(&call->list, &ftrace_events);
2188 call->mod = mod;
2189
2190 return 0;
2191 }
2192
2193 static char *enum_replace(char *ptr, struct trace_enum_map *map, int len)
2194 {
2195 int rlen;
2196 int elen;
2197
2198 /* Find the length of the enum value as a string */
2199 elen = snprintf(ptr, 0, "%ld", map->enum_value);
2200 /* Make sure there's enough room to replace the string with the value */
2201 if (len < elen)
2202 return NULL;
2203
2204 snprintf(ptr, elen + 1, "%ld", map->enum_value);
2205
2206 /* Get the rest of the string of ptr */
2207 rlen = strlen(ptr + len);
2208 memmove(ptr + elen, ptr + len, rlen);
2209 /* Make sure we end the new string */
2210 ptr[elen + rlen] = 0;
2211
2212 return ptr + elen;
2213 }
2214
2215 static void update_event_printk(struct trace_event_call *call,
2216 struct trace_enum_map *map)
2217 {
2218 char *ptr;
2219 int quote = 0;
2220 int len = strlen(map->enum_string);
2221
2222 for (ptr = call->print_fmt; *ptr; ptr++) {
2223 if (*ptr == '\\') {
2224 ptr++;
2225 /* paranoid */
2226 if (!*ptr)
2227 break;
2228 continue;
2229 }
2230 if (*ptr == '"') {
2231 quote ^= 1;
2232 continue;
2233 }
2234 if (quote)
2235 continue;
2236 if (isdigit(*ptr)) {
2237 /* skip numbers */
2238 do {
2239 ptr++;
2240 /* Check for alpha chars like ULL */
2241 } while (isalnum(*ptr));
2242 if (!*ptr)
2243 break;
2244 /*
2245 * A number must have some kind of delimiter after
2246 * it, and we can ignore that too.
2247 */
2248 continue;
2249 }
2250 if (isalpha(*ptr) || *ptr == '_') {
2251 if (strncmp(map->enum_string, ptr, len) == 0 &&
2252 !isalnum(ptr[len]) && ptr[len] != '_') {
2253 ptr = enum_replace(ptr, map, len);
2254 /* Hmm, enum string smaller than value */
2255 if (WARN_ON_ONCE(!ptr))
2256 return;
2257 /*
2258 * No need to decrement here, as enum_replace()
2259 * returns the pointer to the character passed
2260 * the enum, and two enums can not be placed
2261 * back to back without something in between.
2262 * We can skip that something in between.
2263 */
2264 continue;
2265 }
2266 skip_more:
2267 do {
2268 ptr++;
2269 } while (isalnum(*ptr) || *ptr == '_');
2270 if (!*ptr)
2271 break;
2272 /*
2273 * If what comes after this variable is a '.' or
2274 * '->' then we can continue to ignore that string.
2275 */
2276 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2277 ptr += *ptr == '.' ? 1 : 2;
2278 if (!*ptr)
2279 break;
2280 goto skip_more;
2281 }
2282 /*
2283 * Once again, we can skip the delimiter that came
2284 * after the string.
2285 */
2286 continue;
2287 }
2288 }
2289 }
2290
2291 void trace_event_enum_update(struct trace_enum_map **map, int len)
2292 {
2293 struct trace_event_call *call, *p;
2294 const char *last_system = NULL;
2295 int last_i;
2296 int i;
2297
2298 down_write(&trace_event_sem);
2299 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2300 /* events are usually grouped together with systems */
2301 if (!last_system || call->class->system != last_system) {
2302 last_i = 0;
2303 last_system = call->class->system;
2304 }
2305
2306 for (i = last_i; i < len; i++) {
2307 if (call->class->system == map[i]->system) {
2308 /* Save the first system if need be */
2309 if (!last_i)
2310 last_i = i;
2311 update_event_printk(call, map[i]);
2312 }
2313 }
2314 }
2315 up_write(&trace_event_sem);
2316 }
2317
2318 static struct trace_event_file *
2319 trace_create_new_event(struct trace_event_call *call,
2320 struct trace_array *tr)
2321 {
2322 struct trace_event_file *file;
2323
2324 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2325 if (!file)
2326 return NULL;
2327
2328 file->event_call = call;
2329 file->tr = tr;
2330 atomic_set(&file->sm_ref, 0);
2331 atomic_set(&file->tm_ref, 0);
2332 INIT_LIST_HEAD(&file->triggers);
2333 list_add(&file->list, &tr->events);
2334
2335 return file;
2336 }
2337
2338 /* Add an event to a trace directory */
2339 static int
2340 __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2341 {
2342 struct trace_event_file *file;
2343
2344 file = trace_create_new_event(call, tr);
2345 if (!file)
2346 return -ENOMEM;
2347
2348 return event_create_dir(tr->event_dir, file);
2349 }
2350
2351 /*
2352 * Just create a decriptor for early init. A descriptor is required
2353 * for enabling events at boot. We want to enable events before
2354 * the filesystem is initialized.
2355 */
2356 static __init int
2357 __trace_early_add_new_event(struct trace_event_call *call,
2358 struct trace_array *tr)
2359 {
2360 struct trace_event_file *file;
2361
2362 file = trace_create_new_event(call, tr);
2363 if (!file)
2364 return -ENOMEM;
2365
2366 return 0;
2367 }
2368
2369 struct ftrace_module_file_ops;
2370 static void __add_event_to_tracers(struct trace_event_call *call);
2371
2372 /* Add an additional event_call dynamically */
2373 int trace_add_event_call(struct trace_event_call *call)
2374 {
2375 int ret;
2376 mutex_lock(&trace_types_lock);
2377 mutex_lock(&event_mutex);
2378
2379 ret = __register_event(call, NULL);
2380 if (ret >= 0)
2381 __add_event_to_tracers(call);
2382
2383 mutex_unlock(&event_mutex);
2384 mutex_unlock(&trace_types_lock);
2385 return ret;
2386 }
2387
2388 /*
2389 * Must be called under locking of trace_types_lock, event_mutex and
2390 * trace_event_sem.
2391 */
2392 static void __trace_remove_event_call(struct trace_event_call *call)
2393 {
2394 event_remove(call);
2395 trace_destroy_fields(call);
2396 free_event_filter(call->filter);
2397 call->filter = NULL;
2398 }
2399
2400 static int probe_remove_event_call(struct trace_event_call *call)
2401 {
2402 struct trace_array *tr;
2403 struct trace_event_file *file;
2404
2405 #ifdef CONFIG_PERF_EVENTS
2406 if (call->perf_refcount)
2407 return -EBUSY;
2408 #endif
2409 do_for_each_event_file(tr, file) {
2410 if (file->event_call != call)
2411 continue;
2412 /*
2413 * We can't rely on ftrace_event_enable_disable(enable => 0)
2414 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2415 * TRACE_REG_UNREGISTER.
2416 */
2417 if (file->flags & EVENT_FILE_FL_ENABLED)
2418 return -EBUSY;
2419 /*
2420 * The do_for_each_event_file_safe() is
2421 * a double loop. After finding the call for this
2422 * trace_array, we use break to jump to the next
2423 * trace_array.
2424 */
2425 break;
2426 } while_for_each_event_file();
2427
2428 __trace_remove_event_call(call);
2429
2430 return 0;
2431 }
2432
2433 /* Remove an event_call */
2434 int trace_remove_event_call(struct trace_event_call *call)
2435 {
2436 int ret;
2437
2438 mutex_lock(&trace_types_lock);
2439 mutex_lock(&event_mutex);
2440 down_write(&trace_event_sem);
2441 ret = probe_remove_event_call(call);
2442 up_write(&trace_event_sem);
2443 mutex_unlock(&event_mutex);
2444 mutex_unlock(&trace_types_lock);
2445
2446 return ret;
2447 }
2448
2449 #define for_each_event(event, start, end) \
2450 for (event = start; \
2451 (unsigned long)event < (unsigned long)end; \
2452 event++)
2453
2454 #ifdef CONFIG_MODULES
2455
2456 static void trace_module_add_events(struct module *mod)
2457 {
2458 struct trace_event_call **call, **start, **end;
2459
2460 if (!mod->num_trace_events)
2461 return;
2462
2463 /* Don't add infrastructure for mods without tracepoints */
2464 if (trace_module_has_bad_taint(mod)) {
2465 pr_err("%s: module has bad taint, not creating trace events\n",
2466 mod->name);
2467 return;
2468 }
2469
2470 start = mod->trace_events;
2471 end = mod->trace_events + mod->num_trace_events;
2472
2473 for_each_event(call, start, end) {
2474 __register_event(*call, mod);
2475 __add_event_to_tracers(*call);
2476 }
2477 }
2478
2479 static void trace_module_remove_events(struct module *mod)
2480 {
2481 struct trace_event_call *call, *p;
2482 bool clear_trace = false;
2483
2484 down_write(&trace_event_sem);
2485 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2486 if (call->mod == mod) {
2487 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
2488 clear_trace = true;
2489 __trace_remove_event_call(call);
2490 }
2491 }
2492 up_write(&trace_event_sem);
2493
2494 /*
2495 * It is safest to reset the ring buffer if the module being unloaded
2496 * registered any events that were used. The only worry is if
2497 * a new module gets loaded, and takes on the same id as the events
2498 * of this module. When printing out the buffer, traced events left
2499 * over from this module may be passed to the new module events and
2500 * unexpected results may occur.
2501 */
2502 if (clear_trace)
2503 tracing_reset_all_online_cpus();
2504 }
2505
2506 static int trace_module_notify(struct notifier_block *self,
2507 unsigned long val, void *data)
2508 {
2509 struct module *mod = data;
2510
2511 mutex_lock(&trace_types_lock);
2512 mutex_lock(&event_mutex);
2513 switch (val) {
2514 case MODULE_STATE_COMING:
2515 trace_module_add_events(mod);
2516 break;
2517 case MODULE_STATE_GOING:
2518 trace_module_remove_events(mod);
2519 break;
2520 }
2521 mutex_unlock(&event_mutex);
2522 mutex_unlock(&trace_types_lock);
2523
2524 return 0;
2525 }
2526
2527 static struct notifier_block trace_module_nb = {
2528 .notifier_call = trace_module_notify,
2529 .priority = 1, /* higher than trace.c module notify */
2530 };
2531 #endif /* CONFIG_MODULES */
2532
2533 /* Create a new event directory structure for a trace directory. */
2534 static void
2535 __trace_add_event_dirs(struct trace_array *tr)
2536 {
2537 struct trace_event_call *call;
2538 int ret;
2539
2540 list_for_each_entry(call, &ftrace_events, list) {
2541 ret = __trace_add_new_event(call, tr);
2542 if (ret < 0)
2543 pr_warn("Could not create directory for event %s\n",
2544 trace_event_name(call));
2545 }
2546 }
2547
2548 struct trace_event_file *
2549 find_event_file(struct trace_array *tr, const char *system, const char *event)
2550 {
2551 struct trace_event_file *file;
2552 struct trace_event_call *call;
2553 const char *name;
2554
2555 list_for_each_entry(file, &tr->events, list) {
2556
2557 call = file->event_call;
2558 name = trace_event_name(call);
2559
2560 if (!name || !call->class || !call->class->reg)
2561 continue;
2562
2563 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2564 continue;
2565
2566 if (strcmp(event, name) == 0 &&
2567 strcmp(system, call->class->system) == 0)
2568 return file;
2569 }
2570 return NULL;
2571 }
2572
2573 #ifdef CONFIG_DYNAMIC_FTRACE
2574
2575 /* Avoid typos */
2576 #define ENABLE_EVENT_STR "enable_event"
2577 #define DISABLE_EVENT_STR "disable_event"
2578
2579 struct event_probe_data {
2580 struct trace_event_file *file;
2581 unsigned long count;
2582 int ref;
2583 bool enable;
2584 };
2585
2586 static void
2587 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2588 {
2589 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2590 struct event_probe_data *data = *pdata;
2591
2592 if (!data)
2593 return;
2594
2595 if (data->enable)
2596 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2597 else
2598 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2599 }
2600
2601 static void
2602 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
2603 {
2604 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2605 struct event_probe_data *data = *pdata;
2606
2607 if (!data)
2608 return;
2609
2610 if (!data->count)
2611 return;
2612
2613 /* Skip if the event is in a state we want to switch to */
2614 if (data->enable == !(data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
2615 return;
2616
2617 if (data->count != -1)
2618 (data->count)--;
2619
2620 event_enable_probe(ip, parent_ip, _data);
2621 }
2622
2623 static int
2624 event_enable_print(struct seq_file *m, unsigned long ip,
2625 struct ftrace_probe_ops *ops, void *_data)
2626 {
2627 struct event_probe_data *data = _data;
2628
2629 seq_printf(m, "%ps:", (void *)ip);
2630
2631 seq_printf(m, "%s:%s:%s",
2632 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2633 data->file->event_call->class->system,
2634 trace_event_name(data->file->event_call));
2635
2636 if (data->count == -1)
2637 seq_puts(m, ":unlimited\n");
2638 else
2639 seq_printf(m, ":count=%ld\n", data->count);
2640
2641 return 0;
2642 }
2643
2644 static int
2645 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
2646 void **_data)
2647 {
2648 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2649 struct event_probe_data *data = *pdata;
2650
2651 data->ref++;
2652 return 0;
2653 }
2654
2655 static void
2656 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
2657 void **_data)
2658 {
2659 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2660 struct event_probe_data *data = *pdata;
2661
2662 if (WARN_ON_ONCE(data->ref <= 0))
2663 return;
2664
2665 data->ref--;
2666 if (!data->ref) {
2667 /* Remove the SOFT_MODE flag */
2668 __ftrace_event_enable_disable(data->file, 0, 1);
2669 module_put(data->file->event_call->mod);
2670 kfree(data);
2671 }
2672 *pdata = NULL;
2673 }
2674
2675 static struct ftrace_probe_ops event_enable_probe_ops = {
2676 .func = event_enable_probe,
2677 .print = event_enable_print,
2678 .init = event_enable_init,
2679 .free = event_enable_free,
2680 };
2681
2682 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2683 .func = event_enable_count_probe,
2684 .print = event_enable_print,
2685 .init = event_enable_init,
2686 .free = event_enable_free,
2687 };
2688
2689 static struct ftrace_probe_ops event_disable_probe_ops = {
2690 .func = event_enable_probe,
2691 .print = event_enable_print,
2692 .init = event_enable_init,
2693 .free = event_enable_free,
2694 };
2695
2696 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2697 .func = event_enable_count_probe,
2698 .print = event_enable_print,
2699 .init = event_enable_init,
2700 .free = event_enable_free,
2701 };
2702
2703 static int
2704 event_enable_func(struct ftrace_hash *hash,
2705 char *glob, char *cmd, char *param, int enabled)
2706 {
2707 struct trace_array *tr = top_trace_array();
2708 struct trace_event_file *file;
2709 struct ftrace_probe_ops *ops;
2710 struct event_probe_data *data;
2711 const char *system;
2712 const char *event;
2713 char *number;
2714 bool enable;
2715 int ret;
2716
2717 if (!tr)
2718 return -ENODEV;
2719
2720 /* hash funcs only work with set_ftrace_filter */
2721 if (!enabled || !param)
2722 return -EINVAL;
2723
2724 system = strsep(&param, ":");
2725 if (!param)
2726 return -EINVAL;
2727
2728 event = strsep(&param, ":");
2729
2730 mutex_lock(&event_mutex);
2731
2732 ret = -EINVAL;
2733 file = find_event_file(tr, system, event);
2734 if (!file)
2735 goto out;
2736
2737 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2738
2739 if (enable)
2740 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2741 else
2742 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2743
2744 if (glob[0] == '!') {
2745 unregister_ftrace_function_probe_func(glob+1, ops);
2746 ret = 0;
2747 goto out;
2748 }
2749
2750 ret = -ENOMEM;
2751 data = kzalloc(sizeof(*data), GFP_KERNEL);
2752 if (!data)
2753 goto out;
2754
2755 data->enable = enable;
2756 data->count = -1;
2757 data->file = file;
2758
2759 if (!param)
2760 goto out_reg;
2761
2762 number = strsep(&param, ":");
2763
2764 ret = -EINVAL;
2765 if (!strlen(number))
2766 goto out_free;
2767
2768 /*
2769 * We use the callback data field (which is a pointer)
2770 * as our counter.
2771 */
2772 ret = kstrtoul(number, 0, &data->count);
2773 if (ret)
2774 goto out_free;
2775
2776 out_reg:
2777 /* Don't let event modules unload while probe registered */
2778 ret = try_module_get(file->event_call->mod);
2779 if (!ret) {
2780 ret = -EBUSY;
2781 goto out_free;
2782 }
2783
2784 ret = __ftrace_event_enable_disable(file, 1, 1);
2785 if (ret < 0)
2786 goto out_put;
2787 ret = register_ftrace_function_probe(glob, ops, data);
2788 /*
2789 * The above returns on success the # of functions enabled,
2790 * but if it didn't find any functions it returns zero.
2791 * Consider no functions a failure too.
2792 */
2793 if (!ret) {
2794 ret = -ENOENT;
2795 goto out_disable;
2796 } else if (ret < 0)
2797 goto out_disable;
2798 /* Just return zero, not the number of enabled functions */
2799 ret = 0;
2800 out:
2801 mutex_unlock(&event_mutex);
2802 return ret;
2803
2804 out_disable:
2805 __ftrace_event_enable_disable(file, 0, 1);
2806 out_put:
2807 module_put(file->event_call->mod);
2808 out_free:
2809 kfree(data);
2810 goto out;
2811 }
2812
2813 static struct ftrace_func_command event_enable_cmd = {
2814 .name = ENABLE_EVENT_STR,
2815 .func = event_enable_func,
2816 };
2817
2818 static struct ftrace_func_command event_disable_cmd = {
2819 .name = DISABLE_EVENT_STR,
2820 .func = event_enable_func,
2821 };
2822
2823 static __init int register_event_cmds(void)
2824 {
2825 int ret;
2826
2827 ret = register_ftrace_command(&event_enable_cmd);
2828 if (WARN_ON(ret < 0))
2829 return ret;
2830 ret = register_ftrace_command(&event_disable_cmd);
2831 if (WARN_ON(ret < 0))
2832 unregister_ftrace_command(&event_enable_cmd);
2833 return ret;
2834 }
2835 #else
2836 static inline int register_event_cmds(void) { return 0; }
2837 #endif /* CONFIG_DYNAMIC_FTRACE */
2838
2839 /*
2840 * The top level array has already had its trace_event_file
2841 * descriptors created in order to allow for early events to
2842 * be recorded. This function is called after the tracefs has been
2843 * initialized, and we now have to create the files associated
2844 * to the events.
2845 */
2846 static __init void
2847 __trace_early_add_event_dirs(struct trace_array *tr)
2848 {
2849 struct trace_event_file *file;
2850 int ret;
2851
2852
2853 list_for_each_entry(file, &tr->events, list) {
2854 ret = event_create_dir(tr->event_dir, file);
2855 if (ret < 0)
2856 pr_warn("Could not create directory for event %s\n",
2857 trace_event_name(file->event_call));
2858 }
2859 }
2860
2861 /*
2862 * For early boot up, the top trace array requires to have
2863 * a list of events that can be enabled. This must be done before
2864 * the filesystem is set up in order to allow events to be traced
2865 * early.
2866 */
2867 static __init void
2868 __trace_early_add_events(struct trace_array *tr)
2869 {
2870 struct trace_event_call *call;
2871 int ret;
2872
2873 list_for_each_entry(call, &ftrace_events, list) {
2874 /* Early boot up should not have any modules loaded */
2875 if (WARN_ON_ONCE(call->mod))
2876 continue;
2877
2878 ret = __trace_early_add_new_event(call, tr);
2879 if (ret < 0)
2880 pr_warn("Could not create early event %s\n",
2881 trace_event_name(call));
2882 }
2883 }
2884
2885 /* Remove the event directory structure for a trace directory. */
2886 static void
2887 __trace_remove_event_dirs(struct trace_array *tr)
2888 {
2889 struct trace_event_file *file, *next;
2890
2891 list_for_each_entry_safe(file, next, &tr->events, list)
2892 remove_event_file_dir(file);
2893 }
2894
2895 static void __add_event_to_tracers(struct trace_event_call *call)
2896 {
2897 struct trace_array *tr;
2898
2899 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2900 __trace_add_new_event(call, tr);
2901 }
2902
2903 extern struct trace_event_call *__start_ftrace_events[];
2904 extern struct trace_event_call *__stop_ftrace_events[];
2905
2906 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2907
2908 static __init int setup_trace_event(char *str)
2909 {
2910 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2911 ring_buffer_expanded = true;
2912 tracing_selftest_disabled = true;
2913
2914 return 1;
2915 }
2916 __setup("trace_event=", setup_trace_event);
2917
2918 /* Expects to have event_mutex held when called */
2919 static int
2920 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2921 {
2922 struct dentry *d_events;
2923 struct dentry *entry;
2924
2925 entry = tracefs_create_file("set_event", 0644, parent,
2926 tr, &ftrace_set_event_fops);
2927 if (!entry) {
2928 pr_warn("Could not create tracefs 'set_event' entry\n");
2929 return -ENOMEM;
2930 }
2931
2932 d_events = tracefs_create_dir("events", parent);
2933 if (!d_events) {
2934 pr_warn("Could not create tracefs 'events' directory\n");
2935 return -ENOMEM;
2936 }
2937
2938 entry = tracefs_create_file("set_event_pid", 0644, parent,
2939 tr, &ftrace_set_event_pid_fops);
2940
2941 /* ring buffer internal formats */
2942 trace_create_file("header_page", 0444, d_events,
2943 ring_buffer_print_page_header,
2944 &ftrace_show_header_fops);
2945
2946 trace_create_file("header_event", 0444, d_events,
2947 ring_buffer_print_entry_header,
2948 &ftrace_show_header_fops);
2949
2950 trace_create_file("enable", 0644, d_events,
2951 tr, &ftrace_tr_enable_fops);
2952
2953 tr->event_dir = d_events;
2954
2955 return 0;
2956 }
2957
2958 /**
2959 * event_trace_add_tracer - add a instance of a trace_array to events
2960 * @parent: The parent dentry to place the files/directories for events in
2961 * @tr: The trace array associated with these events
2962 *
2963 * When a new instance is created, it needs to set up its events
2964 * directory, as well as other files associated with events. It also
2965 * creates the event hierachry in the @parent/events directory.
2966 *
2967 * Returns 0 on success.
2968 */
2969 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2970 {
2971 int ret;
2972
2973 mutex_lock(&event_mutex);
2974
2975 ret = create_event_toplevel_files(parent, tr);
2976 if (ret)
2977 goto out_unlock;
2978
2979 down_write(&trace_event_sem);
2980 __trace_add_event_dirs(tr);
2981 up_write(&trace_event_sem);
2982
2983 out_unlock:
2984 mutex_unlock(&event_mutex);
2985
2986 return ret;
2987 }
2988
2989 /*
2990 * The top trace array already had its file descriptors created.
2991 * Now the files themselves need to be created.
2992 */
2993 static __init int
2994 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2995 {
2996 int ret;
2997
2998 mutex_lock(&event_mutex);
2999
3000 ret = create_event_toplevel_files(parent, tr);
3001 if (ret)
3002 goto out_unlock;
3003
3004 down_write(&trace_event_sem);
3005 __trace_early_add_event_dirs(tr);
3006 up_write(&trace_event_sem);
3007
3008 out_unlock:
3009 mutex_unlock(&event_mutex);
3010
3011 return ret;
3012 }
3013
3014 int event_trace_del_tracer(struct trace_array *tr)
3015 {
3016 mutex_lock(&event_mutex);
3017
3018 /* Disable any event triggers and associated soft-disabled events */
3019 clear_event_triggers(tr);
3020
3021 /* Clear the pid list */
3022 __ftrace_clear_event_pids(tr);
3023
3024 /* Disable any running events */
3025 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3026
3027 /* Access to events are within rcu_read_lock_sched() */
3028 synchronize_sched();
3029
3030 down_write(&trace_event_sem);
3031 __trace_remove_event_dirs(tr);
3032 tracefs_remove_recursive(tr->event_dir);
3033 up_write(&trace_event_sem);
3034
3035 tr->event_dir = NULL;
3036
3037 mutex_unlock(&event_mutex);
3038
3039 return 0;
3040 }
3041
3042 static __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
3049 static __init void
3050 early_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
3078 static __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 */
3124 static __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
3137 early_initcall(event_trace_enable_again);
3138
3139 static __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
3177 void __init trace_event_init(void)
3178 {
3179 event_trace_memsetup();
3180 init_ftrace_syscalls();
3181 event_trace_enable();
3182 }
3183
3184 fs_initcall(event_trace_init);
3185
3186 #ifdef CONFIG_FTRACE_STARTUP_TEST
3187
3188 static DEFINE_SPINLOCK(test_spinlock);
3189 static DEFINE_SPINLOCK(test_spinlock_irq);
3190 static DEFINE_MUTEX(test_mutex);
3191
3192 static __init void test_work(struct work_struct *dummy)
3193 {
3194 spin_lock(&test_spinlock);
3195 spin_lock_irq(&test_spinlock_irq);
3196 udelay(1);
3197 spin_unlock_irq(&test_spinlock_irq);
3198 spin_unlock(&test_spinlock);
3199
3200 mutex_lock(&test_mutex);
3201 msleep(1);
3202 mutex_unlock(&test_mutex);
3203 }
3204
3205 static __init int event_test_thread(void *unused)
3206 {
3207 void *test_malloc;
3208
3209 test_malloc = kmalloc(1234, GFP_KERNEL);
3210 if (!test_malloc)
3211 pr_info("failed to kmalloc\n");
3212
3213 schedule_on_each_cpu(test_work);
3214
3215 kfree(test_malloc);
3216
3217 set_current_state(TASK_INTERRUPTIBLE);
3218 while (!kthread_should_stop()) {
3219 schedule();
3220 set_current_state(TASK_INTERRUPTIBLE);
3221 }
3222 __set_current_state(TASK_RUNNING);
3223
3224 return 0;
3225 }
3226
3227 /*
3228 * Do various things that may trigger events.
3229 */
3230 static __init void event_test_stuff(void)
3231 {
3232 struct task_struct *test_thread;
3233
3234 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3235 msleep(1);
3236 kthread_stop(test_thread);
3237 }
3238
3239 /*
3240 * For every trace event defined, we will test each trace point separately,
3241 * and then by groups, and finally all trace points.
3242 */
3243 static __init void event_trace_self_tests(void)
3244 {
3245 struct trace_subsystem_dir *dir;
3246 struct trace_event_file *file;
3247 struct trace_event_call *call;
3248 struct event_subsystem *system;
3249 struct trace_array *tr;
3250 int ret;
3251
3252 tr = top_trace_array();
3253 if (!tr)
3254 return;
3255
3256 pr_info("Running tests on trace events:\n");
3257
3258 list_for_each_entry(file, &tr->events, list) {
3259
3260 call = file->event_call;
3261
3262 /* Only test those that have a probe */
3263 if (!call->class || !call->class->probe)
3264 continue;
3265
3266 /*
3267 * Testing syscall events here is pretty useless, but
3268 * we still do it if configured. But this is time consuming.
3269 * What we really need is a user thread to perform the
3270 * syscalls as we test.
3271 */
3272 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3273 if (call->class->system &&
3274 strcmp(call->class->system, "syscalls") == 0)
3275 continue;
3276 #endif
3277
3278 pr_info("Testing event %s: ", trace_event_name(call));
3279
3280 /*
3281 * If an event is already enabled, someone is using
3282 * it and the self test should not be on.
3283 */
3284 if (file->flags & EVENT_FILE_FL_ENABLED) {
3285 pr_warn("Enabled event during self test!\n");
3286 WARN_ON_ONCE(1);
3287 continue;
3288 }
3289
3290 ftrace_event_enable_disable(file, 1);
3291 event_test_stuff();
3292 ftrace_event_enable_disable(file, 0);
3293
3294 pr_cont("OK\n");
3295 }
3296
3297 /* Now test at the sub system level */
3298
3299 pr_info("Running tests on trace event systems:\n");
3300
3301 list_for_each_entry(dir, &tr->systems, list) {
3302
3303 system = dir->subsystem;
3304
3305 /* the ftrace system is special, skip it */
3306 if (strcmp(system->name, "ftrace") == 0)
3307 continue;
3308
3309 pr_info("Testing event system %s: ", system->name);
3310
3311 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3312 if (WARN_ON_ONCE(ret)) {
3313 pr_warn("error enabling system %s\n",
3314 system->name);
3315 continue;
3316 }
3317
3318 event_test_stuff();
3319
3320 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3321 if (WARN_ON_ONCE(ret)) {
3322 pr_warn("error disabling system %s\n",
3323 system->name);
3324 continue;
3325 }
3326
3327 pr_cont("OK\n");
3328 }
3329
3330 /* Test with all events enabled */
3331
3332 pr_info("Running tests on all trace events:\n");
3333 pr_info("Testing all events: ");
3334
3335 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3336 if (WARN_ON_ONCE(ret)) {
3337 pr_warn("error enabling all events\n");
3338 return;
3339 }
3340
3341 event_test_stuff();
3342
3343 /* reset sysname */
3344 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3345 if (WARN_ON_ONCE(ret)) {
3346 pr_warn("error disabling all events\n");
3347 return;
3348 }
3349
3350 pr_cont("OK\n");
3351 }
3352
3353 #ifdef CONFIG_FUNCTION_TRACER
3354
3355 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3356
3357 static struct trace_array *event_tr;
3358
3359 static void __init
3360 function_test_events_call(unsigned long ip, unsigned long parent_ip,
3361 struct ftrace_ops *op, struct pt_regs *pt_regs)
3362 {
3363 struct ring_buffer_event *event;
3364 struct ring_buffer *buffer;
3365 struct ftrace_entry *entry;
3366 unsigned long flags;
3367 long disabled;
3368 int cpu;
3369 int pc;
3370
3371 pc = preempt_count();
3372 preempt_disable_notrace();
3373 cpu = raw_smp_processor_id();
3374 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3375
3376 if (disabled != 1)
3377 goto out;
3378
3379 local_save_flags(flags);
3380
3381 event = trace_current_buffer_lock_reserve(&buffer,
3382 TRACE_FN, sizeof(*entry),
3383 flags, pc);
3384 if (!event)
3385 goto out;
3386 entry = ring_buffer_event_data(event);
3387 entry->ip = ip;
3388 entry->parent_ip = parent_ip;
3389
3390 trace_buffer_unlock_commit(event_tr, buffer, event, flags, pc);
3391
3392 out:
3393 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3394 preempt_enable_notrace();
3395 }
3396
3397 static struct ftrace_ops trace_ops __initdata =
3398 {
3399 .func = function_test_events_call,
3400 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
3401 };
3402
3403 static __init void event_trace_self_test_with_function(void)
3404 {
3405 int ret;
3406 event_tr = top_trace_array();
3407 if (WARN_ON(!event_tr))
3408 return;
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
3419 static __init void event_trace_self_test_with_function(void)
3420 {
3421 }
3422 #endif
3423
3424 static __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
3434 late_initcall(event_trace_self_tests_init);
3435
3436 #endif
Linux with added FPC-III support