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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * event tracer
4 *
5 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
6 *
7 * - Added format output of fields of the trace point.
8 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
9 *
10 */
11
12#define pr_fmt(fmt) fmt
13
14#include <linux/workqueue.h>
15#include <linux/security.h>
16#include <linux/spinlock.h>
17#include <linux/kthread.h>
18#include <linux/tracefs.h>
19#include <linux/uaccess.h>
20#include <linux/module.h>
21#include <linux/ctype.h>
22#include <linux/sort.h>
23#include <linux/slab.h>
24#include <linux/delay.h>
25
26#include <trace/events/sched.h>
27#include <trace/syscall.h>
28
29#include <asm/setup.h>
30
31#include "trace_output.h"
32
33#undef TRACE_SYSTEM
34#define TRACE_SYSTEM "TRACE_SYSTEM"
35
36DEFINE_MUTEX(event_mutex);
37
38LIST_HEAD(ftrace_events);
39static LIST_HEAD(ftrace_generic_fields);
40static LIST_HEAD(ftrace_common_fields);
41static bool eventdir_initialized;
42
43#define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
44
45static struct kmem_cache *field_cachep;
46static struct kmem_cache *file_cachep;
47
48static inline int system_refcount(struct event_subsystem *system)
49{
50 return system->ref_count;
51}
52
53static int system_refcount_inc(struct event_subsystem *system)
54{
55 return system->ref_count++;
56}
57
58static int system_refcount_dec(struct event_subsystem *system)
59{
60 return --system->ref_count;
61}
62
63/* Double loops, do not use break, only goto's work */
64#define do_for_each_event_file(tr, file) \
65 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
66 list_for_each_entry(file, &tr->events, list)
67
68#define do_for_each_event_file_safe(tr, file) \
69 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
70 struct trace_event_file *___n; \
71 list_for_each_entry_safe(file, ___n, &tr->events, list)
72
73#define while_for_each_event_file() \
74 }
75
76static struct ftrace_event_field *
77__find_event_field(struct list_head *head, char *name)
78{
79 struct ftrace_event_field *field;
80
81 list_for_each_entry(field, head, link) {
82 if (!strcmp(field->name, name))
83 return field;
84 }
85
86 return NULL;
87}
88
89struct ftrace_event_field *
90trace_find_event_field(struct trace_event_call *call, char *name)
91{
92 struct ftrace_event_field *field;
93 struct list_head *head;
94
95 head = trace_get_fields(call);
96 field = __find_event_field(head, name);
97 if (field)
98 return field;
99
100 field = __find_event_field(&ftrace_generic_fields, name);
101 if (field)
102 return field;
103
104 return __find_event_field(&ftrace_common_fields, name);
105}
106
107static int __trace_define_field(struct list_head *head, const char *type,
108 const char *name, int offset, int size,
109 int is_signed, int filter_type)
110{
111 struct ftrace_event_field *field;
112
113 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
114 if (!field)
115 return -ENOMEM;
116
117 field->name = name;
118 field->type = type;
119
120 if (filter_type == FILTER_OTHER)
121 field->filter_type = filter_assign_type(type);
122 else
123 field->filter_type = filter_type;
124
125 field->offset = offset;
126 field->size = size;
127 field->is_signed = is_signed;
128
129 list_add(&field->link, head);
130
131 return 0;
132}
133
134int trace_define_field(struct trace_event_call *call, const char *type,
135 const char *name, int offset, int size, int is_signed,
136 int filter_type)
137{
138 struct list_head *head;
139
140 if (WARN_ON(!call->class))
141 return 0;
142
143 head = trace_get_fields(call);
144 return __trace_define_field(head, type, name, offset, size,
145 is_signed, filter_type);
146}
147EXPORT_SYMBOL_GPL(trace_define_field);
148
149#define __generic_field(type, item, filter_type) \
150 ret = __trace_define_field(&ftrace_generic_fields, #type, \
151 #item, 0, 0, is_signed_type(type), \
152 filter_type); \
153 if (ret) \
154 return ret;
155
156#define __common_field(type, item) \
157 ret = __trace_define_field(&ftrace_common_fields, #type, \
158 "common_" #item, \
159 offsetof(typeof(ent), item), \
160 sizeof(ent.item), \
161 is_signed_type(type), FILTER_OTHER); \
162 if (ret) \
163 return ret;
164
165static int trace_define_generic_fields(void)
166{
167 int ret;
168
169 __generic_field(int, CPU, FILTER_CPU);
170 __generic_field(int, cpu, FILTER_CPU);
171 __generic_field(char *, COMM, FILTER_COMM);
172 __generic_field(char *, comm, FILTER_COMM);
173
174 return ret;
175}
176
177static int trace_define_common_fields(void)
178{
179 int ret;
180 struct trace_entry ent;
181
182 __common_field(unsigned short, type);
183 __common_field(unsigned char, flags);
184 __common_field(unsigned char, preempt_count);
185 __common_field(int, pid);
186
187 return ret;
188}
189
190static void trace_destroy_fields(struct trace_event_call *call)
191{
192 struct ftrace_event_field *field, *next;
193 struct list_head *head;
194
195 head = trace_get_fields(call);
196 list_for_each_entry_safe(field, next, head, link) {
197 list_del(&field->link);
198 kmem_cache_free(field_cachep, field);
199 }
200}
201
202/*
203 * run-time version of trace_event_get_offsets_<call>() that returns the last
204 * accessible offset of trace fields excluding __dynamic_array bytes
205 */
206int trace_event_get_offsets(struct trace_event_call *call)
207{
208 struct ftrace_event_field *tail;
209 struct list_head *head;
210
211 head = trace_get_fields(call);
212 /*
213 * head->next points to the last field with the largest offset,
214 * since it was added last by trace_define_field()
215 */
216 tail = list_first_entry(head, struct ftrace_event_field, link);
217 return tail->offset + tail->size;
218}
219
220/*
221 * Check if the referenced field is an array and return true,
222 * as arrays are OK to dereference.
223 */
224static bool test_field(const char *fmt, struct trace_event_call *call)
225{
226 struct trace_event_fields *field = call->class->fields_array;
227 const char *array_descriptor;
228 const char *p = fmt;
229 int len;
230
231 if (!(len = str_has_prefix(fmt, "REC->")))
232 return false;
233 fmt += len;
234 for (p = fmt; *p; p++) {
235 if (!isalnum(*p) && *p != '_')
236 break;
237 }
238 len = p - fmt;
239
240 for (; field->type; field++) {
241 if (strncmp(field->name, fmt, len) ||
242 field->name[len])
243 continue;
244 array_descriptor = strchr(field->type, '[');
245 /* This is an array and is OK to dereference. */
246 return array_descriptor != NULL;
247 }
248 return false;
249}
250
251/*
252 * Examine the print fmt of the event looking for unsafe dereference
253 * pointers using %p* that could be recorded in the trace event and
254 * much later referenced after the pointer was freed. Dereferencing
255 * pointers are OK, if it is dereferenced into the event itself.
256 */
257static void test_event_printk(struct trace_event_call *call)
258{
259 u64 dereference_flags = 0;
260 bool first = true;
261 const char *fmt, *c, *r, *a;
262 int parens = 0;
263 char in_quote = 0;
264 int start_arg = 0;
265 int arg = 0;
266 int i;
267
268 fmt = call->print_fmt;
269
270 if (!fmt)
271 return;
272
273 for (i = 0; fmt[i]; i++) {
274 switch (fmt[i]) {
275 case '\\':
276 i++;
277 if (!fmt[i])
278 return;
279 continue;
280 case '"':
281 case '\'':
282 /*
283 * The print fmt starts with a string that
284 * is processed first to find %p* usage,
285 * then after the first string, the print fmt
286 * contains arguments that are used to check
287 * if the dereferenced %p* usage is safe.
288 */
289 if (first) {
290 if (fmt[i] == '\'')
291 continue;
292 if (in_quote) {
293 arg = 0;
294 first = false;
295 /*
296 * If there was no %p* uses
297 * the fmt is OK.
298 */
299 if (!dereference_flags)
300 return;
301 }
302 }
303 if (in_quote) {
304 if (in_quote == fmt[i])
305 in_quote = 0;
306 } else {
307 in_quote = fmt[i];
308 }
309 continue;
310 case '%':
311 if (!first || !in_quote)
312 continue;
313 i++;
314 if (!fmt[i])
315 return;
316 switch (fmt[i]) {
317 case '%':
318 continue;
319 case 'p':
320 /* Find dereferencing fields */
321 switch (fmt[i + 1]) {
322 case 'B': case 'R': case 'r':
323 case 'b': case 'M': case 'm':
324 case 'I': case 'i': case 'E':
325 case 'U': case 'V': case 'N':
326 case 'a': case 'd': case 'D':
327 case 'g': case 't': case 'C':
328 case 'O': case 'f':
329 if (WARN_ONCE(arg == 63,
330 "Too many args for event: %s",
331 trace_event_name(call)))
332 return;
333 dereference_flags |= 1ULL << arg;
334 }
335 break;
336 default:
337 {
338 bool star = false;
339 int j;
340
341 /* Increment arg if %*s exists. */
342 for (j = 0; fmt[i + j]; j++) {
343 if (isdigit(fmt[i + j]) ||
344 fmt[i + j] == '.')
345 continue;
346 if (fmt[i + j] == '*') {
347 star = true;
348 continue;
349 }
350 if ((fmt[i + j] == 's') && star)
351 arg++;
352 break;
353 }
354 break;
355 } /* default */
356
357 } /* switch */
358 arg++;
359 continue;
360 case '(':
361 if (in_quote)
362 continue;
363 parens++;
364 continue;
365 case ')':
366 if (in_quote)
367 continue;
368 parens--;
369 if (WARN_ONCE(parens < 0,
370 "Paren mismatch for event: %s\narg='%s'\n%*s",
371 trace_event_name(call),
372 fmt + start_arg,
373 (i - start_arg) + 5, "^"))
374 return;
375 continue;
376 case ',':
377 if (in_quote || parens)
378 continue;
379 i++;
380 while (isspace(fmt[i]))
381 i++;
382 start_arg = i;
383 if (!(dereference_flags & (1ULL << arg)))
384 goto next_arg;
385
386 /* Find the REC-> in the argument */
387 c = strchr(fmt + i, ',');
388 r = strstr(fmt + i, "REC->");
389 if (r && (!c || r < c)) {
390 /*
391 * Addresses of events on the buffer,
392 * or an array on the buffer is
393 * OK to dereference.
394 * There's ways to fool this, but
395 * this is to catch common mistakes,
396 * not malicious code.
397 */
398 a = strchr(fmt + i, '&');
399 if ((a && (a < r)) || test_field(r, call))
400 dereference_flags &= ~(1ULL << arg);
401 }
402 next_arg:
403 i--;
404 arg++;
405 }
406 }
407
408 /*
409 * If you triggered the below warning, the trace event reported
410 * uses an unsafe dereference pointer %p*. As the data stored
411 * at the trace event time may no longer exist when the trace
412 * event is printed, dereferencing to the original source is
413 * unsafe. The source of the dereference must be copied into the
414 * event itself, and the dereference must access the copy instead.
415 */
416 if (WARN_ON_ONCE(dereference_flags)) {
417 arg = 1;
418 while (!(dereference_flags & 1)) {
419 dereference_flags >>= 1;
420 arg++;
421 }
422 pr_warn("event %s has unsafe dereference of argument %d\n",
423 trace_event_name(call), arg);
424 pr_warn("print_fmt: %s\n", fmt);
425 }
426}
427
428int trace_event_raw_init(struct trace_event_call *call)
429{
430 int id;
431
432 id = register_trace_event(&call->event);
433 if (!id)
434 return -ENODEV;
435
436 test_event_printk(call);
437
438 return 0;
439}
440EXPORT_SYMBOL_GPL(trace_event_raw_init);
441
442bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
443{
444 struct trace_array *tr = trace_file->tr;
445 struct trace_array_cpu *data;
446 struct trace_pid_list *no_pid_list;
447 struct trace_pid_list *pid_list;
448
449 pid_list = rcu_dereference_raw(tr->filtered_pids);
450 no_pid_list = rcu_dereference_raw(tr->filtered_no_pids);
451
452 if (!pid_list && !no_pid_list)
453 return false;
454
455 data = this_cpu_ptr(tr->array_buffer.data);
456
457 return data->ignore_pid;
458}
459EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
460
461void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
462 struct trace_event_file *trace_file,
463 unsigned long len)
464{
465 struct trace_event_call *event_call = trace_file->event_call;
466
467 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
468 trace_event_ignore_this_pid(trace_file))
469 return NULL;
470
471 /*
472 * If CONFIG_PREEMPTION is enabled, then the tracepoint itself disables
473 * preemption (adding one to the preempt_count). Since we are
474 * interested in the preempt_count at the time the tracepoint was
475 * hit, we need to subtract one to offset the increment.
476 */
477 fbuffer->trace_ctx = tracing_gen_ctx_dec();
478 fbuffer->trace_file = trace_file;
479
480 fbuffer->event =
481 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
482 event_call->event.type, len,
483 fbuffer->trace_ctx);
484 if (!fbuffer->event)
485 return NULL;
486
487 fbuffer->regs = NULL;
488 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
489 return fbuffer->entry;
490}
491EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
492
493int trace_event_reg(struct trace_event_call *call,
494 enum trace_reg type, void *data)
495{
496 struct trace_event_file *file = data;
497
498 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
499 switch (type) {
500 case TRACE_REG_REGISTER:
501 return tracepoint_probe_register(call->tp,
502 call->class->probe,
503 file);
504 case TRACE_REG_UNREGISTER:
505 tracepoint_probe_unregister(call->tp,
506 call->class->probe,
507 file);
508 return 0;
509
510#ifdef CONFIG_PERF_EVENTS
511 case TRACE_REG_PERF_REGISTER:
512 return tracepoint_probe_register(call->tp,
513 call->class->perf_probe,
514 call);
515 case TRACE_REG_PERF_UNREGISTER:
516 tracepoint_probe_unregister(call->tp,
517 call->class->perf_probe,
518 call);
519 return 0;
520 case TRACE_REG_PERF_OPEN:
521 case TRACE_REG_PERF_CLOSE:
522 case TRACE_REG_PERF_ADD:
523 case TRACE_REG_PERF_DEL:
524 return 0;
525#endif
526 }
527 return 0;
528}
529EXPORT_SYMBOL_GPL(trace_event_reg);
530
531void trace_event_enable_cmd_record(bool enable)
532{
533 struct trace_event_file *file;
534 struct trace_array *tr;
535
536 lockdep_assert_held(&event_mutex);
537
538 do_for_each_event_file(tr, file) {
539
540 if (!(file->flags & EVENT_FILE_FL_ENABLED))
541 continue;
542
543 if (enable) {
544 tracing_start_cmdline_record();
545 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
546 } else {
547 tracing_stop_cmdline_record();
548 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
549 }
550 } while_for_each_event_file();
551}
552
553void trace_event_enable_tgid_record(bool enable)
554{
555 struct trace_event_file *file;
556 struct trace_array *tr;
557
558 lockdep_assert_held(&event_mutex);
559
560 do_for_each_event_file(tr, file) {
561 if (!(file->flags & EVENT_FILE_FL_ENABLED))
562 continue;
563
564 if (enable) {
565 tracing_start_tgid_record();
566 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
567 } else {
568 tracing_stop_tgid_record();
569 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
570 &file->flags);
571 }
572 } while_for_each_event_file();
573}
574
575static int __ftrace_event_enable_disable(struct trace_event_file *file,
576 int enable, int soft_disable)
577{
578 struct trace_event_call *call = file->event_call;
579 struct trace_array *tr = file->tr;
580 unsigned long file_flags = file->flags;
581 int ret = 0;
582 int disable;
583
584 switch (enable) {
585 case 0:
586 /*
587 * When soft_disable is set and enable is cleared, the sm_ref
588 * reference counter is decremented. If it reaches 0, we want
589 * to clear the SOFT_DISABLED flag but leave the event in the
590 * state that it was. That is, if the event was enabled and
591 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
592 * is set we do not want the event to be enabled before we
593 * clear the bit.
594 *
595 * When soft_disable is not set but the SOFT_MODE flag is,
596 * we do nothing. Do not disable the tracepoint, otherwise
597 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
598 */
599 if (soft_disable) {
600 if (atomic_dec_return(&file->sm_ref) > 0)
601 break;
602 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
603 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
604 } else
605 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
606
607 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
608 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
609 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
610 tracing_stop_cmdline_record();
611 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
612 }
613
614 if (file->flags & EVENT_FILE_FL_RECORDED_TGID) {
615 tracing_stop_tgid_record();
616 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
617 }
618
619 call->class->reg(call, TRACE_REG_UNREGISTER, file);
620 }
621 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
622 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
623 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
624 else
625 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
626 break;
627 case 1:
628 /*
629 * When soft_disable is set and enable is set, we want to
630 * register the tracepoint for the event, but leave the event
631 * as is. That means, if the event was already enabled, we do
632 * nothing (but set SOFT_MODE). If the event is disabled, we
633 * set SOFT_DISABLED before enabling the event tracepoint, so
634 * it still seems to be disabled.
635 */
636 if (!soft_disable)
637 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
638 else {
639 if (atomic_inc_return(&file->sm_ref) > 1)
640 break;
641 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
642 }
643
644 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
645 bool cmd = false, tgid = false;
646
647 /* Keep the event disabled, when going to SOFT_MODE. */
648 if (soft_disable)
649 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
650
651 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
652 cmd = true;
653 tracing_start_cmdline_record();
654 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
655 }
656
657 if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
658 tgid = true;
659 tracing_start_tgid_record();
660 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
661 }
662
663 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
664 if (ret) {
665 if (cmd)
666 tracing_stop_cmdline_record();
667 if (tgid)
668 tracing_stop_tgid_record();
669 pr_info("event trace: Could not enable event "
670 "%s\n", trace_event_name(call));
671 break;
672 }
673 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
674
675 /* WAS_ENABLED gets set but never cleared. */
676 set_bit(EVENT_FILE_FL_WAS_ENABLED_BIT, &file->flags);
677 }
678 break;
679 }
680
681 /* Enable or disable use of trace_buffered_event */
682 if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) !=
683 (file->flags & EVENT_FILE_FL_SOFT_DISABLED)) {
684 if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
685 trace_buffered_event_enable();
686 else
687 trace_buffered_event_disable();
688 }
689
690 return ret;
691}
692
693int trace_event_enable_disable(struct trace_event_file *file,
694 int enable, int soft_disable)
695{
696 return __ftrace_event_enable_disable(file, enable, soft_disable);
697}
698
699static int ftrace_event_enable_disable(struct trace_event_file *file,
700 int enable)
701{
702 return __ftrace_event_enable_disable(file, enable, 0);
703}
704
705static void ftrace_clear_events(struct trace_array *tr)
706{
707 struct trace_event_file *file;
708
709 mutex_lock(&event_mutex);
710 list_for_each_entry(file, &tr->events, list) {
711 ftrace_event_enable_disable(file, 0);
712 }
713 mutex_unlock(&event_mutex);
714}
715
716static void
717event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
718{
719 struct trace_pid_list *pid_list;
720 struct trace_array *tr = data;
721
722 pid_list = rcu_dereference_raw(tr->filtered_pids);
723 trace_filter_add_remove_task(pid_list, NULL, task);
724
725 pid_list = rcu_dereference_raw(tr->filtered_no_pids);
726 trace_filter_add_remove_task(pid_list, NULL, task);
727}
728
729static void
730event_filter_pid_sched_process_fork(void *data,
731 struct task_struct *self,
732 struct task_struct *task)
733{
734 struct trace_pid_list *pid_list;
735 struct trace_array *tr = data;
736
737 pid_list = rcu_dereference_sched(tr->filtered_pids);
738 trace_filter_add_remove_task(pid_list, self, task);
739
740 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
741 trace_filter_add_remove_task(pid_list, self, task);
742}
743
744void trace_event_follow_fork(struct trace_array *tr, bool enable)
745{
746 if (enable) {
747 register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
748 tr, INT_MIN);
749 register_trace_prio_sched_process_free(event_filter_pid_sched_process_exit,
750 tr, INT_MAX);
751 } else {
752 unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
753 tr);
754 unregister_trace_sched_process_free(event_filter_pid_sched_process_exit,
755 tr);
756 }
757}
758
759static void
760event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
761 struct task_struct *prev, struct task_struct *next)
762{
763 struct trace_array *tr = data;
764 struct trace_pid_list *no_pid_list;
765 struct trace_pid_list *pid_list;
766 bool ret;
767
768 pid_list = rcu_dereference_sched(tr->filtered_pids);
769 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
770
771 /*
772 * Sched switch is funny, as we only want to ignore it
773 * in the notrace case if both prev and next should be ignored.
774 */
775 ret = trace_ignore_this_task(NULL, no_pid_list, prev) &&
776 trace_ignore_this_task(NULL, no_pid_list, next);
777
778 this_cpu_write(tr->array_buffer.data->ignore_pid, ret ||
779 (trace_ignore_this_task(pid_list, NULL, prev) &&
780 trace_ignore_this_task(pid_list, NULL, next)));
781}
782
783static void
784event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
785 struct task_struct *prev, struct task_struct *next)
786{
787 struct trace_array *tr = data;
788 struct trace_pid_list *no_pid_list;
789 struct trace_pid_list *pid_list;
790
791 pid_list = rcu_dereference_sched(tr->filtered_pids);
792 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
793
794 this_cpu_write(tr->array_buffer.data->ignore_pid,
795 trace_ignore_this_task(pid_list, no_pid_list, next));
796}
797
798static void
799event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
800{
801 struct trace_array *tr = data;
802 struct trace_pid_list *no_pid_list;
803 struct trace_pid_list *pid_list;
804
805 /* Nothing to do if we are already tracing */
806 if (!this_cpu_read(tr->array_buffer.data->ignore_pid))
807 return;
808
809 pid_list = rcu_dereference_sched(tr->filtered_pids);
810 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
811
812 this_cpu_write(tr->array_buffer.data->ignore_pid,
813 trace_ignore_this_task(pid_list, no_pid_list, task));
814}
815
816static void
817event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
818{
819 struct trace_array *tr = data;
820 struct trace_pid_list *no_pid_list;
821 struct trace_pid_list *pid_list;
822
823 /* Nothing to do if we are not tracing */
824 if (this_cpu_read(tr->array_buffer.data->ignore_pid))
825 return;
826
827 pid_list = rcu_dereference_sched(tr->filtered_pids);
828 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
829
830 /* Set tracing if current is enabled */
831 this_cpu_write(tr->array_buffer.data->ignore_pid,
832 trace_ignore_this_task(pid_list, no_pid_list, current));
833}
834
835static void unregister_pid_events(struct trace_array *tr)
836{
837 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
838 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
839
840 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
841 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
842
843 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
844 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
845
846 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
847 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
848}
849
850static void __ftrace_clear_event_pids(struct trace_array *tr, int type)
851{
852 struct trace_pid_list *pid_list;
853 struct trace_pid_list *no_pid_list;
854 struct trace_event_file *file;
855 int cpu;
856
857 pid_list = rcu_dereference_protected(tr->filtered_pids,
858 lockdep_is_held(&event_mutex));
859 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
860 lockdep_is_held(&event_mutex));
861
862 /* Make sure there's something to do */
863 if (!pid_type_enabled(type, pid_list, no_pid_list))
864 return;
865
866 if (!still_need_pid_events(type, pid_list, no_pid_list)) {
867 unregister_pid_events(tr);
868
869 list_for_each_entry(file, &tr->events, list) {
870 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
871 }
872
873 for_each_possible_cpu(cpu)
874 per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false;
875 }
876
877 if (type & TRACE_PIDS)
878 rcu_assign_pointer(tr->filtered_pids, NULL);
879
880 if (type & TRACE_NO_PIDS)
881 rcu_assign_pointer(tr->filtered_no_pids, NULL);
882
883 /* Wait till all users are no longer using pid filtering */
884 tracepoint_synchronize_unregister();
885
886 if ((type & TRACE_PIDS) && pid_list)
887 trace_free_pid_list(pid_list);
888
889 if ((type & TRACE_NO_PIDS) && no_pid_list)
890 trace_free_pid_list(no_pid_list);
891}
892
893static void ftrace_clear_event_pids(struct trace_array *tr, int type)
894{
895 mutex_lock(&event_mutex);
896 __ftrace_clear_event_pids(tr, type);
897 mutex_unlock(&event_mutex);
898}
899
900static void __put_system(struct event_subsystem *system)
901{
902 struct event_filter *filter = system->filter;
903
904 WARN_ON_ONCE(system_refcount(system) == 0);
905 if (system_refcount_dec(system))
906 return;
907
908 list_del(&system->list);
909
910 if (filter) {
911 kfree(filter->filter_string);
912 kfree(filter);
913 }
914 kfree_const(system->name);
915 kfree(system);
916}
917
918static void __get_system(struct event_subsystem *system)
919{
920 WARN_ON_ONCE(system_refcount(system) == 0);
921 system_refcount_inc(system);
922}
923
924static void __get_system_dir(struct trace_subsystem_dir *dir)
925{
926 WARN_ON_ONCE(dir->ref_count == 0);
927 dir->ref_count++;
928 __get_system(dir->subsystem);
929}
930
931static void __put_system_dir(struct trace_subsystem_dir *dir)
932{
933 WARN_ON_ONCE(dir->ref_count == 0);
934 /* If the subsystem is about to be freed, the dir must be too */
935 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
936
937 __put_system(dir->subsystem);
938 if (!--dir->ref_count)
939 kfree(dir);
940}
941
942static void put_system(struct trace_subsystem_dir *dir)
943{
944 mutex_lock(&event_mutex);
945 __put_system_dir(dir);
946 mutex_unlock(&event_mutex);
947}
948
949static void remove_subsystem(struct trace_subsystem_dir *dir)
950{
951 if (!dir)
952 return;
953
954 if (!--dir->nr_events) {
955 tracefs_remove(dir->entry);
956 list_del(&dir->list);
957 __put_system_dir(dir);
958 }
959}
960
961static void remove_event_file_dir(struct trace_event_file *file)
962{
963 struct dentry *dir = file->dir;
964 struct dentry *child;
965
966 if (dir) {
967 spin_lock(&dir->d_lock); /* probably unneeded */
968 list_for_each_entry(child, &dir->d_subdirs, d_child) {
969 if (d_really_is_positive(child)) /* probably unneeded */
970 d_inode(child)->i_private = NULL;
971 }
972 spin_unlock(&dir->d_lock);
973
974 tracefs_remove(dir);
975 }
976
977 list_del(&file->list);
978 remove_subsystem(file->system);
979 free_event_filter(file->filter);
980 kmem_cache_free(file_cachep, file);
981}
982
983/*
984 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
985 */
986static int
987__ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
988 const char *sub, const char *event, int set)
989{
990 struct trace_event_file *file;
991 struct trace_event_call *call;
992 const char *name;
993 int ret = -EINVAL;
994 int eret = 0;
995
996 list_for_each_entry(file, &tr->events, list) {
997
998 call = file->event_call;
999 name = trace_event_name(call);
1000
1001 if (!name || !call->class || !call->class->reg)
1002 continue;
1003
1004 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1005 continue;
1006
1007 if (match &&
1008 strcmp(match, name) != 0 &&
1009 strcmp(match, call->class->system) != 0)
1010 continue;
1011
1012 if (sub && strcmp(sub, call->class->system) != 0)
1013 continue;
1014
1015 if (event && strcmp(event, name) != 0)
1016 continue;
1017
1018 ret = ftrace_event_enable_disable(file, set);
1019
1020 /*
1021 * Save the first error and return that. Some events
1022 * may still have been enabled, but let the user
1023 * know that something went wrong.
1024 */
1025 if (ret && !eret)
1026 eret = ret;
1027
1028 ret = eret;
1029 }
1030
1031 return ret;
1032}
1033
1034static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
1035 const char *sub, const char *event, int set)
1036{
1037 int ret;
1038
1039 mutex_lock(&event_mutex);
1040 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
1041 mutex_unlock(&event_mutex);
1042
1043 return ret;
1044}
1045
1046int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
1047{
1048 char *event = NULL, *sub = NULL, *match;
1049 int ret;
1050
1051 if (!tr)
1052 return -ENOENT;
1053 /*
1054 * The buf format can be <subsystem>:<event-name>
1055 * *:<event-name> means any event by that name.
1056 * :<event-name> is the same.
1057 *
1058 * <subsystem>:* means all events in that subsystem
1059 * <subsystem>: means the same.
1060 *
1061 * <name> (no ':') means all events in a subsystem with
1062 * the name <name> or any event that matches <name>
1063 */
1064
1065 match = strsep(&buf, ":");
1066 if (buf) {
1067 sub = match;
1068 event = buf;
1069 match = NULL;
1070
1071 if (!strlen(sub) || strcmp(sub, "*") == 0)
1072 sub = NULL;
1073 if (!strlen(event) || strcmp(event, "*") == 0)
1074 event = NULL;
1075 }
1076
1077 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
1078
1079 /* Put back the colon to allow this to be called again */
1080 if (buf)
1081 *(buf - 1) = ':';
1082
1083 return ret;
1084}
1085
1086/**
1087 * trace_set_clr_event - enable or disable an event
1088 * @system: system name to match (NULL for any system)
1089 * @event: event name to match (NULL for all events, within system)
1090 * @set: 1 to enable, 0 to disable
1091 *
1092 * This is a way for other parts of the kernel to enable or disable
1093 * event recording.
1094 *
1095 * Returns 0 on success, -EINVAL if the parameters do not match any
1096 * registered events.
1097 */
1098int trace_set_clr_event(const char *system, const char *event, int set)
1099{
1100 struct trace_array *tr = top_trace_array();
1101
1102 if (!tr)
1103 return -ENODEV;
1104
1105 return __ftrace_set_clr_event(tr, NULL, system, event, set);
1106}
1107EXPORT_SYMBOL_GPL(trace_set_clr_event);
1108
1109/**
1110 * trace_array_set_clr_event - enable or disable an event for a trace array.
1111 * @tr: concerned trace array.
1112 * @system: system name to match (NULL for any system)
1113 * @event: event name to match (NULL for all events, within system)
1114 * @enable: true to enable, false to disable
1115 *
1116 * This is a way for other parts of the kernel to enable or disable
1117 * event recording.
1118 *
1119 * Returns 0 on success, -EINVAL if the parameters do not match any
1120 * registered events.
1121 */
1122int trace_array_set_clr_event(struct trace_array *tr, const char *system,
1123 const char *event, bool enable)
1124{
1125 int set;
1126
1127 if (!tr)
1128 return -ENOENT;
1129
1130 set = (enable == true) ? 1 : 0;
1131 return __ftrace_set_clr_event(tr, NULL, system, event, set);
1132}
1133EXPORT_SYMBOL_GPL(trace_array_set_clr_event);
1134
1135/* 128 should be much more than enough */
1136#define EVENT_BUF_SIZE 127
1137
1138static ssize_t
1139ftrace_event_write(struct file *file, const char __user *ubuf,
1140 size_t cnt, loff_t *ppos)
1141{
1142 struct trace_parser parser;
1143 struct seq_file *m = file->private_data;
1144 struct trace_array *tr = m->private;
1145 ssize_t read, ret;
1146
1147 if (!cnt)
1148 return 0;
1149
1150 ret = tracing_update_buffers();
1151 if (ret < 0)
1152 return ret;
1153
1154 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
1155 return -ENOMEM;
1156
1157 read = trace_get_user(&parser, ubuf, cnt, ppos);
1158
1159 if (read >= 0 && trace_parser_loaded((&parser))) {
1160 int set = 1;
1161
1162 if (*parser.buffer == '!')
1163 set = 0;
1164
1165 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
1166 if (ret)
1167 goto out_put;
1168 }
1169
1170 ret = read;
1171
1172 out_put:
1173 trace_parser_put(&parser);
1174
1175 return ret;
1176}
1177
1178static void *
1179t_next(struct seq_file *m, void *v, loff_t *pos)
1180{
1181 struct trace_event_file *file = v;
1182 struct trace_event_call *call;
1183 struct trace_array *tr = m->private;
1184
1185 (*pos)++;
1186
1187 list_for_each_entry_continue(file, &tr->events, list) {
1188 call = file->event_call;
1189 /*
1190 * The ftrace subsystem is for showing formats only.
1191 * They can not be enabled or disabled via the event files.
1192 */
1193 if (call->class && call->class->reg &&
1194 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1195 return file;
1196 }
1197
1198 return NULL;
1199}
1200
1201static void *t_start(struct seq_file *m, loff_t *pos)
1202{
1203 struct trace_event_file *file;
1204 struct trace_array *tr = m->private;
1205 loff_t l;
1206
1207 mutex_lock(&event_mutex);
1208
1209 file = list_entry(&tr->events, struct trace_event_file, list);
1210 for (l = 0; l <= *pos; ) {
1211 file = t_next(m, file, &l);
1212 if (!file)
1213 break;
1214 }
1215 return file;
1216}
1217
1218static void *
1219s_next(struct seq_file *m, void *v, loff_t *pos)
1220{
1221 struct trace_event_file *file = v;
1222 struct trace_array *tr = m->private;
1223
1224 (*pos)++;
1225
1226 list_for_each_entry_continue(file, &tr->events, list) {
1227 if (file->flags & EVENT_FILE_FL_ENABLED)
1228 return file;
1229 }
1230
1231 return NULL;
1232}
1233
1234static void *s_start(struct seq_file *m, loff_t *pos)
1235{
1236 struct trace_event_file *file;
1237 struct trace_array *tr = m->private;
1238 loff_t l;
1239
1240 mutex_lock(&event_mutex);
1241
1242 file = list_entry(&tr->events, struct trace_event_file, list);
1243 for (l = 0; l <= *pos; ) {
1244 file = s_next(m, file, &l);
1245 if (!file)
1246 break;
1247 }
1248 return file;
1249}
1250
1251static int t_show(struct seq_file *m, void *v)
1252{
1253 struct trace_event_file *file = v;
1254 struct trace_event_call *call = file->event_call;
1255
1256 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1257 seq_printf(m, "%s:", call->class->system);
1258 seq_printf(m, "%s\n", trace_event_name(call));
1259
1260 return 0;
1261}
1262
1263static void t_stop(struct seq_file *m, void *p)
1264{
1265 mutex_unlock(&event_mutex);
1266}
1267
1268static void *
1269__next(struct seq_file *m, void *v, loff_t *pos, int type)
1270{
1271 struct trace_array *tr = m->private;
1272 struct trace_pid_list *pid_list;
1273
1274 if (type == TRACE_PIDS)
1275 pid_list = rcu_dereference_sched(tr->filtered_pids);
1276 else
1277 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1278
1279 return trace_pid_next(pid_list, v, pos);
1280}
1281
1282static void *
1283p_next(struct seq_file *m, void *v, loff_t *pos)
1284{
1285 return __next(m, v, pos, TRACE_PIDS);
1286}
1287
1288static void *
1289np_next(struct seq_file *m, void *v, loff_t *pos)
1290{
1291 return __next(m, v, pos, TRACE_NO_PIDS);
1292}
1293
1294static void *__start(struct seq_file *m, loff_t *pos, int type)
1295 __acquires(RCU)
1296{
1297 struct trace_pid_list *pid_list;
1298 struct trace_array *tr = m->private;
1299
1300 /*
1301 * Grab the mutex, to keep calls to p_next() having the same
1302 * tr->filtered_pids as p_start() has.
1303 * If we just passed the tr->filtered_pids around, then RCU would
1304 * have been enough, but doing that makes things more complex.
1305 */
1306 mutex_lock(&event_mutex);
1307 rcu_read_lock_sched();
1308
1309 if (type == TRACE_PIDS)
1310 pid_list = rcu_dereference_sched(tr->filtered_pids);
1311 else
1312 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1313
1314 if (!pid_list)
1315 return NULL;
1316
1317 return trace_pid_start(pid_list, pos);
1318}
1319
1320static void *p_start(struct seq_file *m, loff_t *pos)
1321 __acquires(RCU)
1322{
1323 return __start(m, pos, TRACE_PIDS);
1324}
1325
1326static void *np_start(struct seq_file *m, loff_t *pos)
1327 __acquires(RCU)
1328{
1329 return __start(m, pos, TRACE_NO_PIDS);
1330}
1331
1332static void p_stop(struct seq_file *m, void *p)
1333 __releases(RCU)
1334{
1335 rcu_read_unlock_sched();
1336 mutex_unlock(&event_mutex);
1337}
1338
1339static ssize_t
1340event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1341 loff_t *ppos)
1342{
1343 struct trace_event_file *file;
1344 unsigned long flags;
1345 char buf[4] = "0";
1346
1347 mutex_lock(&event_mutex);
1348 file = event_file_data(filp);
1349 if (likely(file))
1350 flags = file->flags;
1351 mutex_unlock(&event_mutex);
1352
1353 if (!file)
1354 return -ENODEV;
1355
1356 if (flags & EVENT_FILE_FL_ENABLED &&
1357 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1358 strcpy(buf, "1");
1359
1360 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1361 flags & EVENT_FILE_FL_SOFT_MODE)
1362 strcat(buf, "*");
1363
1364 strcat(buf, "\n");
1365
1366 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1367}
1368
1369static ssize_t
1370event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1371 loff_t *ppos)
1372{
1373 struct trace_event_file *file;
1374 unsigned long val;
1375 int ret;
1376
1377 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1378 if (ret)
1379 return ret;
1380
1381 ret = tracing_update_buffers();
1382 if (ret < 0)
1383 return ret;
1384
1385 switch (val) {
1386 case 0:
1387 case 1:
1388 ret = -ENODEV;
1389 mutex_lock(&event_mutex);
1390 file = event_file_data(filp);
1391 if (likely(file))
1392 ret = ftrace_event_enable_disable(file, val);
1393 mutex_unlock(&event_mutex);
1394 break;
1395
1396 default:
1397 return -EINVAL;
1398 }
1399
1400 *ppos += cnt;
1401
1402 return ret ? ret : cnt;
1403}
1404
1405static ssize_t
1406system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1407 loff_t *ppos)
1408{
1409 const char set_to_char[4] = { '?', '0', '1', 'X' };
1410 struct trace_subsystem_dir *dir = filp->private_data;
1411 struct event_subsystem *system = dir->subsystem;
1412 struct trace_event_call *call;
1413 struct trace_event_file *file;
1414 struct trace_array *tr = dir->tr;
1415 char buf[2];
1416 int set = 0;
1417 int ret;
1418
1419 mutex_lock(&event_mutex);
1420 list_for_each_entry(file, &tr->events, list) {
1421 call = file->event_call;
1422 if ((call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) ||
1423 !trace_event_name(call) || !call->class || !call->class->reg)
1424 continue;
1425
1426 if (system && strcmp(call->class->system, system->name) != 0)
1427 continue;
1428
1429 /*
1430 * We need to find out if all the events are set
1431 * or if all events or cleared, or if we have
1432 * a mixture.
1433 */
1434 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1435
1436 /*
1437 * If we have a mixture, no need to look further.
1438 */
1439 if (set == 3)
1440 break;
1441 }
1442 mutex_unlock(&event_mutex);
1443
1444 buf[0] = set_to_char[set];
1445 buf[1] = '\n';
1446
1447 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1448
1449 return ret;
1450}
1451
1452static ssize_t
1453system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1454 loff_t *ppos)
1455{
1456 struct trace_subsystem_dir *dir = filp->private_data;
1457 struct event_subsystem *system = dir->subsystem;
1458 const char *name = NULL;
1459 unsigned long val;
1460 ssize_t ret;
1461
1462 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1463 if (ret)
1464 return ret;
1465
1466 ret = tracing_update_buffers();
1467 if (ret < 0)
1468 return ret;
1469
1470 if (val != 0 && val != 1)
1471 return -EINVAL;
1472
1473 /*
1474 * Opening of "enable" adds a ref count to system,
1475 * so the name is safe to use.
1476 */
1477 if (system)
1478 name = system->name;
1479
1480 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1481 if (ret)
1482 goto out;
1483
1484 ret = cnt;
1485
1486out:
1487 *ppos += cnt;
1488
1489 return ret;
1490}
1491
1492enum {
1493 FORMAT_HEADER = 1,
1494 FORMAT_FIELD_SEPERATOR = 2,
1495 FORMAT_PRINTFMT = 3,
1496};
1497
1498static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1499{
1500 struct trace_event_call *call = event_file_data(m->private);
1501 struct list_head *common_head = &ftrace_common_fields;
1502 struct list_head *head = trace_get_fields(call);
1503 struct list_head *node = v;
1504
1505 (*pos)++;
1506
1507 switch ((unsigned long)v) {
1508 case FORMAT_HEADER:
1509 node = common_head;
1510 break;
1511
1512 case FORMAT_FIELD_SEPERATOR:
1513 node = head;
1514 break;
1515
1516 case FORMAT_PRINTFMT:
1517 /* all done */
1518 return NULL;
1519 }
1520
1521 node = node->prev;
1522 if (node == common_head)
1523 return (void *)FORMAT_FIELD_SEPERATOR;
1524 else if (node == head)
1525 return (void *)FORMAT_PRINTFMT;
1526 else
1527 return node;
1528}
1529
1530static int f_show(struct seq_file *m, void *v)
1531{
1532 struct trace_event_call *call = event_file_data(m->private);
1533 struct ftrace_event_field *field;
1534 const char *array_descriptor;
1535
1536 switch ((unsigned long)v) {
1537 case FORMAT_HEADER:
1538 seq_printf(m, "name: %s\n", trace_event_name(call));
1539 seq_printf(m, "ID: %d\n", call->event.type);
1540 seq_puts(m, "format:\n");
1541 return 0;
1542
1543 case FORMAT_FIELD_SEPERATOR:
1544 seq_putc(m, '\n');
1545 return 0;
1546
1547 case FORMAT_PRINTFMT:
1548 seq_printf(m, "\nprint fmt: %s\n",
1549 call->print_fmt);
1550 return 0;
1551 }
1552
1553 field = list_entry(v, struct ftrace_event_field, link);
1554 /*
1555 * Smartly shows the array type(except dynamic array).
1556 * Normal:
1557 * field:TYPE VAR
1558 * If TYPE := TYPE[LEN], it is shown:
1559 * field:TYPE VAR[LEN]
1560 */
1561 array_descriptor = strchr(field->type, '[');
1562
1563 if (str_has_prefix(field->type, "__data_loc"))
1564 array_descriptor = NULL;
1565
1566 if (!array_descriptor)
1567 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1568 field->type, field->name, field->offset,
1569 field->size, !!field->is_signed);
1570 else
1571 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1572 (int)(array_descriptor - field->type),
1573 field->type, field->name,
1574 array_descriptor, field->offset,
1575 field->size, !!field->is_signed);
1576
1577 return 0;
1578}
1579
1580static void *f_start(struct seq_file *m, loff_t *pos)
1581{
1582 void *p = (void *)FORMAT_HEADER;
1583 loff_t l = 0;
1584
1585 /* ->stop() is called even if ->start() fails */
1586 mutex_lock(&event_mutex);
1587 if (!event_file_data(m->private))
1588 return ERR_PTR(-ENODEV);
1589
1590 while (l < *pos && p)
1591 p = f_next(m, p, &l);
1592
1593 return p;
1594}
1595
1596static void f_stop(struct seq_file *m, void *p)
1597{
1598 mutex_unlock(&event_mutex);
1599}
1600
1601static const struct seq_operations trace_format_seq_ops = {
1602 .start = f_start,
1603 .next = f_next,
1604 .stop = f_stop,
1605 .show = f_show,
1606};
1607
1608static int trace_format_open(struct inode *inode, struct file *file)
1609{
1610 struct seq_file *m;
1611 int ret;
1612
1613 /* Do we want to hide event format files on tracefs lockdown? */
1614
1615 ret = seq_open(file, &trace_format_seq_ops);
1616 if (ret < 0)
1617 return ret;
1618
1619 m = file->private_data;
1620 m->private = file;
1621
1622 return 0;
1623}
1624
1625static ssize_t
1626event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1627{
1628 int id = (long)event_file_data(filp);
1629 char buf[32];
1630 int len;
1631
1632 if (unlikely(!id))
1633 return -ENODEV;
1634
1635 len = sprintf(buf, "%d\n", id);
1636
1637 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1638}
1639
1640static ssize_t
1641event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1642 loff_t *ppos)
1643{
1644 struct trace_event_file *file;
1645 struct trace_seq *s;
1646 int r = -ENODEV;
1647
1648 if (*ppos)
1649 return 0;
1650
1651 s = kmalloc(sizeof(*s), GFP_KERNEL);
1652
1653 if (!s)
1654 return -ENOMEM;
1655
1656 trace_seq_init(s);
1657
1658 mutex_lock(&event_mutex);
1659 file = event_file_data(filp);
1660 if (file)
1661 print_event_filter(file, s);
1662 mutex_unlock(&event_mutex);
1663
1664 if (file)
1665 r = simple_read_from_buffer(ubuf, cnt, ppos,
1666 s->buffer, trace_seq_used(s));
1667
1668 kfree(s);
1669
1670 return r;
1671}
1672
1673static ssize_t
1674event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1675 loff_t *ppos)
1676{
1677 struct trace_event_file *file;
1678 char *buf;
1679 int err = -ENODEV;
1680
1681 if (cnt >= PAGE_SIZE)
1682 return -EINVAL;
1683
1684 buf = memdup_user_nul(ubuf, cnt);
1685 if (IS_ERR(buf))
1686 return PTR_ERR(buf);
1687
1688 mutex_lock(&event_mutex);
1689 file = event_file_data(filp);
1690 if (file)
1691 err = apply_event_filter(file, buf);
1692 mutex_unlock(&event_mutex);
1693
1694 kfree(buf);
1695 if (err < 0)
1696 return err;
1697
1698 *ppos += cnt;
1699
1700 return cnt;
1701}
1702
1703static LIST_HEAD(event_subsystems);
1704
1705static int subsystem_open(struct inode *inode, struct file *filp)
1706{
1707 struct event_subsystem *system = NULL;
1708 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1709 struct trace_array *tr;
1710 int ret;
1711
1712 if (tracing_is_disabled())
1713 return -ENODEV;
1714
1715 /* Make sure the system still exists */
1716 mutex_lock(&event_mutex);
1717 mutex_lock(&trace_types_lock);
1718 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1719 list_for_each_entry(dir, &tr->systems, list) {
1720 if (dir == inode->i_private) {
1721 /* Don't open systems with no events */
1722 if (dir->nr_events) {
1723 __get_system_dir(dir);
1724 system = dir->subsystem;
1725 }
1726 goto exit_loop;
1727 }
1728 }
1729 }
1730 exit_loop:
1731 mutex_unlock(&trace_types_lock);
1732 mutex_unlock(&event_mutex);
1733
1734 if (!system)
1735 return -ENODEV;
1736
1737 /* Some versions of gcc think dir can be uninitialized here */
1738 WARN_ON(!dir);
1739
1740 /* Still need to increment the ref count of the system */
1741 if (trace_array_get(tr) < 0) {
1742 put_system(dir);
1743 return -ENODEV;
1744 }
1745
1746 ret = tracing_open_generic(inode, filp);
1747 if (ret < 0) {
1748 trace_array_put(tr);
1749 put_system(dir);
1750 }
1751
1752 return ret;
1753}
1754
1755static int system_tr_open(struct inode *inode, struct file *filp)
1756{
1757 struct trace_subsystem_dir *dir;
1758 struct trace_array *tr = inode->i_private;
1759 int ret;
1760
1761 /* Make a temporary dir that has no system but points to tr */
1762 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1763 if (!dir)
1764 return -ENOMEM;
1765
1766 ret = tracing_open_generic_tr(inode, filp);
1767 if (ret < 0) {
1768 kfree(dir);
1769 return ret;
1770 }
1771 dir->tr = tr;
1772 filp->private_data = dir;
1773
1774 return 0;
1775}
1776
1777static int subsystem_release(struct inode *inode, struct file *file)
1778{
1779 struct trace_subsystem_dir *dir = file->private_data;
1780
1781 trace_array_put(dir->tr);
1782
1783 /*
1784 * If dir->subsystem is NULL, then this is a temporary
1785 * descriptor that was made for a trace_array to enable
1786 * all subsystems.
1787 */
1788 if (dir->subsystem)
1789 put_system(dir);
1790 else
1791 kfree(dir);
1792
1793 return 0;
1794}
1795
1796static ssize_t
1797subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1798 loff_t *ppos)
1799{
1800 struct trace_subsystem_dir *dir = filp->private_data;
1801 struct event_subsystem *system = dir->subsystem;
1802 struct trace_seq *s;
1803 int r;
1804
1805 if (*ppos)
1806 return 0;
1807
1808 s = kmalloc(sizeof(*s), GFP_KERNEL);
1809 if (!s)
1810 return -ENOMEM;
1811
1812 trace_seq_init(s);
1813
1814 print_subsystem_event_filter(system, s);
1815 r = simple_read_from_buffer(ubuf, cnt, ppos,
1816 s->buffer, trace_seq_used(s));
1817
1818 kfree(s);
1819
1820 return r;
1821}
1822
1823static ssize_t
1824subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1825 loff_t *ppos)
1826{
1827 struct trace_subsystem_dir *dir = filp->private_data;
1828 char *buf;
1829 int err;
1830
1831 if (cnt >= PAGE_SIZE)
1832 return -EINVAL;
1833
1834 buf = memdup_user_nul(ubuf, cnt);
1835 if (IS_ERR(buf))
1836 return PTR_ERR(buf);
1837
1838 err = apply_subsystem_event_filter(dir, buf);
1839 kfree(buf);
1840 if (err < 0)
1841 return err;
1842
1843 *ppos += cnt;
1844
1845 return cnt;
1846}
1847
1848static ssize_t
1849show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1850{
1851 int (*func)(struct trace_seq *s) = filp->private_data;
1852 struct trace_seq *s;
1853 int r;
1854
1855 if (*ppos)
1856 return 0;
1857
1858 s = kmalloc(sizeof(*s), GFP_KERNEL);
1859 if (!s)
1860 return -ENOMEM;
1861
1862 trace_seq_init(s);
1863
1864 func(s);
1865 r = simple_read_from_buffer(ubuf, cnt, ppos,
1866 s->buffer, trace_seq_used(s));
1867
1868 kfree(s);
1869
1870 return r;
1871}
1872
1873static void ignore_task_cpu(void *data)
1874{
1875 struct trace_array *tr = data;
1876 struct trace_pid_list *pid_list;
1877 struct trace_pid_list *no_pid_list;
1878
1879 /*
1880 * This function is called by on_each_cpu() while the
1881 * event_mutex is held.
1882 */
1883 pid_list = rcu_dereference_protected(tr->filtered_pids,
1884 mutex_is_locked(&event_mutex));
1885 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
1886 mutex_is_locked(&event_mutex));
1887
1888 this_cpu_write(tr->array_buffer.data->ignore_pid,
1889 trace_ignore_this_task(pid_list, no_pid_list, current));
1890}
1891
1892static void register_pid_events(struct trace_array *tr)
1893{
1894 /*
1895 * Register a probe that is called before all other probes
1896 * to set ignore_pid if next or prev do not match.
1897 * Register a probe this is called after all other probes
1898 * to only keep ignore_pid set if next pid matches.
1899 */
1900 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1901 tr, INT_MAX);
1902 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1903 tr, 0);
1904
1905 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1906 tr, INT_MAX);
1907 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1908 tr, 0);
1909
1910 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1911 tr, INT_MAX);
1912 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1913 tr, 0);
1914
1915 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1916 tr, INT_MAX);
1917 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1918 tr, 0);
1919}
1920
1921static ssize_t
1922event_pid_write(struct file *filp, const char __user *ubuf,
1923 size_t cnt, loff_t *ppos, int type)
1924{
1925 struct seq_file *m = filp->private_data;
1926 struct trace_array *tr = m->private;
1927 struct trace_pid_list *filtered_pids = NULL;
1928 struct trace_pid_list *other_pids = NULL;
1929 struct trace_pid_list *pid_list;
1930 struct trace_event_file *file;
1931 ssize_t ret;
1932
1933 if (!cnt)
1934 return 0;
1935
1936 ret = tracing_update_buffers();
1937 if (ret < 0)
1938 return ret;
1939
1940 mutex_lock(&event_mutex);
1941
1942 if (type == TRACE_PIDS) {
1943 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1944 lockdep_is_held(&event_mutex));
1945 other_pids = rcu_dereference_protected(tr->filtered_no_pids,
1946 lockdep_is_held(&event_mutex));
1947 } else {
1948 filtered_pids = rcu_dereference_protected(tr->filtered_no_pids,
1949 lockdep_is_held(&event_mutex));
1950 other_pids = rcu_dereference_protected(tr->filtered_pids,
1951 lockdep_is_held(&event_mutex));
1952 }
1953
1954 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
1955 if (ret < 0)
1956 goto out;
1957
1958 if (type == TRACE_PIDS)
1959 rcu_assign_pointer(tr->filtered_pids, pid_list);
1960 else
1961 rcu_assign_pointer(tr->filtered_no_pids, pid_list);
1962
1963 list_for_each_entry(file, &tr->events, list) {
1964 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1965 }
1966
1967 if (filtered_pids) {
1968 tracepoint_synchronize_unregister();
1969 trace_free_pid_list(filtered_pids);
1970 } else if (pid_list && !other_pids) {
1971 register_pid_events(tr);
1972 }
1973
1974 /*
1975 * Ignoring of pids is done at task switch. But we have to
1976 * check for those tasks that are currently running.
1977 * Always do this in case a pid was appended or removed.
1978 */
1979 on_each_cpu(ignore_task_cpu, tr, 1);
1980
1981 out:
1982 mutex_unlock(&event_mutex);
1983
1984 if (ret > 0)
1985 *ppos += ret;
1986
1987 return ret;
1988}
1989
1990static ssize_t
1991ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1992 size_t cnt, loff_t *ppos)
1993{
1994 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
1995}
1996
1997static ssize_t
1998ftrace_event_npid_write(struct file *filp, const char __user *ubuf,
1999 size_t cnt, loff_t *ppos)
2000{
2001 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
2002}
2003
2004static int ftrace_event_avail_open(struct inode *inode, struct file *file);
2005static int ftrace_event_set_open(struct inode *inode, struct file *file);
2006static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
2007static int ftrace_event_set_npid_open(struct inode *inode, struct file *file);
2008static int ftrace_event_release(struct inode *inode, struct file *file);
2009
2010static const struct seq_operations show_event_seq_ops = {
2011 .start = t_start,
2012 .next = t_next,
2013 .show = t_show,
2014 .stop = t_stop,
2015};
2016
2017static const struct seq_operations show_set_event_seq_ops = {
2018 .start = s_start,
2019 .next = s_next,
2020 .show = t_show,
2021 .stop = t_stop,
2022};
2023
2024static const struct seq_operations show_set_pid_seq_ops = {
2025 .start = p_start,
2026 .next = p_next,
2027 .show = trace_pid_show,
2028 .stop = p_stop,
2029};
2030
2031static const struct seq_operations show_set_no_pid_seq_ops = {
2032 .start = np_start,
2033 .next = np_next,
2034 .show = trace_pid_show,
2035 .stop = p_stop,
2036};
2037
2038static const struct file_operations ftrace_avail_fops = {
2039 .open = ftrace_event_avail_open,
2040 .read = seq_read,
2041 .llseek = seq_lseek,
2042 .release = seq_release,
2043};
2044
2045static const struct file_operations ftrace_set_event_fops = {
2046 .open = ftrace_event_set_open,
2047 .read = seq_read,
2048 .write = ftrace_event_write,
2049 .llseek = seq_lseek,
2050 .release = ftrace_event_release,
2051};
2052
2053static const struct file_operations ftrace_set_event_pid_fops = {
2054 .open = ftrace_event_set_pid_open,
2055 .read = seq_read,
2056 .write = ftrace_event_pid_write,
2057 .llseek = seq_lseek,
2058 .release = ftrace_event_release,
2059};
2060
2061static const struct file_operations ftrace_set_event_notrace_pid_fops = {
2062 .open = ftrace_event_set_npid_open,
2063 .read = seq_read,
2064 .write = ftrace_event_npid_write,
2065 .llseek = seq_lseek,
2066 .release = ftrace_event_release,
2067};
2068
2069static const struct file_operations ftrace_enable_fops = {
2070 .open = tracing_open_generic,
2071 .read = event_enable_read,
2072 .write = event_enable_write,
2073 .llseek = default_llseek,
2074};
2075
2076static const struct file_operations ftrace_event_format_fops = {
2077 .open = trace_format_open,
2078 .read = seq_read,
2079 .llseek = seq_lseek,
2080 .release = seq_release,
2081};
2082
2083static const struct file_operations ftrace_event_id_fops = {
2084 .read = event_id_read,
2085 .llseek = default_llseek,
2086};
2087
2088static const struct file_operations ftrace_event_filter_fops = {
2089 .open = tracing_open_generic,
2090 .read = event_filter_read,
2091 .write = event_filter_write,
2092 .llseek = default_llseek,
2093};
2094
2095static const struct file_operations ftrace_subsystem_filter_fops = {
2096 .open = subsystem_open,
2097 .read = subsystem_filter_read,
2098 .write = subsystem_filter_write,
2099 .llseek = default_llseek,
2100 .release = subsystem_release,
2101};
2102
2103static const struct file_operations ftrace_system_enable_fops = {
2104 .open = subsystem_open,
2105 .read = system_enable_read,
2106 .write = system_enable_write,
2107 .llseek = default_llseek,
2108 .release = subsystem_release,
2109};
2110
2111static const struct file_operations ftrace_tr_enable_fops = {
2112 .open = system_tr_open,
2113 .read = system_enable_read,
2114 .write = system_enable_write,
2115 .llseek = default_llseek,
2116 .release = subsystem_release,
2117};
2118
2119static const struct file_operations ftrace_show_header_fops = {
2120 .open = tracing_open_generic,
2121 .read = show_header,
2122 .llseek = default_llseek,
2123};
2124
2125static int
2126ftrace_event_open(struct inode *inode, struct file *file,
2127 const struct seq_operations *seq_ops)
2128{
2129 struct seq_file *m;
2130 int ret;
2131
2132 ret = security_locked_down(LOCKDOWN_TRACEFS);
2133 if (ret)
2134 return ret;
2135
2136 ret = seq_open(file, seq_ops);
2137 if (ret < 0)
2138 return ret;
2139 m = file->private_data;
2140 /* copy tr over to seq ops */
2141 m->private = inode->i_private;
2142
2143 return ret;
2144}
2145
2146static int ftrace_event_release(struct inode *inode, struct file *file)
2147{
2148 struct trace_array *tr = inode->i_private;
2149
2150 trace_array_put(tr);
2151
2152 return seq_release(inode, file);
2153}
2154
2155static int
2156ftrace_event_avail_open(struct inode *inode, struct file *file)
2157{
2158 const struct seq_operations *seq_ops = &show_event_seq_ops;
2159
2160 /* Checks for tracefs lockdown */
2161 return ftrace_event_open(inode, file, seq_ops);
2162}
2163
2164static int
2165ftrace_event_set_open(struct inode *inode, struct file *file)
2166{
2167 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
2168 struct trace_array *tr = inode->i_private;
2169 int ret;
2170
2171 ret = tracing_check_open_get_tr(tr);
2172 if (ret)
2173 return ret;
2174
2175 if ((file->f_mode & FMODE_WRITE) &&
2176 (file->f_flags & O_TRUNC))
2177 ftrace_clear_events(tr);
2178
2179 ret = ftrace_event_open(inode, file, seq_ops);
2180 if (ret < 0)
2181 trace_array_put(tr);
2182 return ret;
2183}
2184
2185static int
2186ftrace_event_set_pid_open(struct inode *inode, struct file *file)
2187{
2188 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
2189 struct trace_array *tr = inode->i_private;
2190 int ret;
2191
2192 ret = tracing_check_open_get_tr(tr);
2193 if (ret)
2194 return ret;
2195
2196 if ((file->f_mode & FMODE_WRITE) &&
2197 (file->f_flags & O_TRUNC))
2198 ftrace_clear_event_pids(tr, TRACE_PIDS);
2199
2200 ret = ftrace_event_open(inode, file, seq_ops);
2201 if (ret < 0)
2202 trace_array_put(tr);
2203 return ret;
2204}
2205
2206static int
2207ftrace_event_set_npid_open(struct inode *inode, struct file *file)
2208{
2209 const struct seq_operations *seq_ops = &show_set_no_pid_seq_ops;
2210 struct trace_array *tr = inode->i_private;
2211 int ret;
2212
2213 ret = tracing_check_open_get_tr(tr);
2214 if (ret)
2215 return ret;
2216
2217 if ((file->f_mode & FMODE_WRITE) &&
2218 (file->f_flags & O_TRUNC))
2219 ftrace_clear_event_pids(tr, TRACE_NO_PIDS);
2220
2221 ret = ftrace_event_open(inode, file, seq_ops);
2222 if (ret < 0)
2223 trace_array_put(tr);
2224 return ret;
2225}
2226
2227static struct event_subsystem *
2228create_new_subsystem(const char *name)
2229{
2230 struct event_subsystem *system;
2231
2232 /* need to create new entry */
2233 system = kmalloc(sizeof(*system), GFP_KERNEL);
2234 if (!system)
2235 return NULL;
2236
2237 system->ref_count = 1;
2238
2239 /* Only allocate if dynamic (kprobes and modules) */
2240 system->name = kstrdup_const(name, GFP_KERNEL);
2241 if (!system->name)
2242 goto out_free;
2243
2244 system->filter = NULL;
2245
2246 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
2247 if (!system->filter)
2248 goto out_free;
2249
2250 list_add(&system->list, &event_subsystems);
2251
2252 return system;
2253
2254 out_free:
2255 kfree_const(system->name);
2256 kfree(system);
2257 return NULL;
2258}
2259
2260static struct dentry *
2261event_subsystem_dir(struct trace_array *tr, const char *name,
2262 struct trace_event_file *file, struct dentry *parent)
2263{
2264 struct trace_subsystem_dir *dir;
2265 struct event_subsystem *system;
2266 struct dentry *entry;
2267
2268 /* First see if we did not already create this dir */
2269 list_for_each_entry(dir, &tr->systems, list) {
2270 system = dir->subsystem;
2271 if (strcmp(system->name, name) == 0) {
2272 dir->nr_events++;
2273 file->system = dir;
2274 return dir->entry;
2275 }
2276 }
2277
2278 /* Now see if the system itself exists. */
2279 list_for_each_entry(system, &event_subsystems, list) {
2280 if (strcmp(system->name, name) == 0)
2281 break;
2282 }
2283 /* Reset system variable when not found */
2284 if (&system->list == &event_subsystems)
2285 system = NULL;
2286
2287 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
2288 if (!dir)
2289 goto out_fail;
2290
2291 if (!system) {
2292 system = create_new_subsystem(name);
2293 if (!system)
2294 goto out_free;
2295 } else
2296 __get_system(system);
2297
2298 dir->entry = tracefs_create_dir(name, parent);
2299 if (!dir->entry) {
2300 pr_warn("Failed to create system directory %s\n", name);
2301 __put_system(system);
2302 goto out_free;
2303 }
2304
2305 dir->tr = tr;
2306 dir->ref_count = 1;
2307 dir->nr_events = 1;
2308 dir->subsystem = system;
2309 file->system = dir;
2310
2311 /* the ftrace system is special, do not create enable or filter files */
2312 if (strcmp(name, "ftrace") != 0) {
2313
2314 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
2315 &ftrace_subsystem_filter_fops);
2316 if (!entry) {
2317 kfree(system->filter);
2318 system->filter = NULL;
2319 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
2320 }
2321
2322 trace_create_file("enable", 0644, dir->entry, dir,
2323 &ftrace_system_enable_fops);
2324 }
2325
2326 list_add(&dir->list, &tr->systems);
2327
2328 return dir->entry;
2329
2330 out_free:
2331 kfree(dir);
2332 out_fail:
2333 /* Only print this message if failed on memory allocation */
2334 if (!dir || !system)
2335 pr_warn("No memory to create event subsystem %s\n", name);
2336 return NULL;
2337}
2338
2339static int
2340event_define_fields(struct trace_event_call *call)
2341{
2342 struct list_head *head;
2343 int ret = 0;
2344
2345 /*
2346 * Other events may have the same class. Only update
2347 * the fields if they are not already defined.
2348 */
2349 head = trace_get_fields(call);
2350 if (list_empty(head)) {
2351 struct trace_event_fields *field = call->class->fields_array;
2352 unsigned int offset = sizeof(struct trace_entry);
2353
2354 for (; field->type; field++) {
2355 if (field->type == TRACE_FUNCTION_TYPE) {
2356 field->define_fields(call);
2357 break;
2358 }
2359
2360 offset = ALIGN(offset, field->align);
2361 ret = trace_define_field(call, field->type, field->name,
2362 offset, field->size,
2363 field->is_signed, field->filter_type);
2364 if (WARN_ON_ONCE(ret)) {
2365 pr_err("error code is %d\n", ret);
2366 break;
2367 }
2368
2369 offset += field->size;
2370 }
2371 }
2372
2373 return ret;
2374}
2375
2376static int
2377event_create_dir(struct dentry *parent, struct trace_event_file *file)
2378{
2379 struct trace_event_call *call = file->event_call;
2380 struct trace_array *tr = file->tr;
2381 struct dentry *d_events;
2382 const char *name;
2383 int ret;
2384
2385 /*
2386 * If the trace point header did not define TRACE_SYSTEM
2387 * then the system would be called "TRACE_SYSTEM".
2388 */
2389 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
2390 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
2391 if (!d_events)
2392 return -ENOMEM;
2393 } else
2394 d_events = parent;
2395
2396 name = trace_event_name(call);
2397 file->dir = tracefs_create_dir(name, d_events);
2398 if (!file->dir) {
2399 pr_warn("Could not create tracefs '%s' directory\n", name);
2400 return -1;
2401 }
2402
2403 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2404 trace_create_file("enable", 0644, file->dir, file,
2405 &ftrace_enable_fops);
2406
2407#ifdef CONFIG_PERF_EVENTS
2408 if (call->event.type && call->class->reg)
2409 trace_create_file("id", 0444, file->dir,
2410 (void *)(long)call->event.type,
2411 &ftrace_event_id_fops);
2412#endif
2413
2414 ret = event_define_fields(call);
2415 if (ret < 0) {
2416 pr_warn("Could not initialize trace point events/%s\n", name);
2417 return ret;
2418 }
2419
2420 /*
2421 * Only event directories that can be enabled should have
2422 * triggers or filters.
2423 */
2424 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
2425 trace_create_file("filter", 0644, file->dir, file,
2426 &ftrace_event_filter_fops);
2427
2428 trace_create_file("trigger", 0644, file->dir, file,
2429 &event_trigger_fops);
2430 }
2431
2432#ifdef CONFIG_HIST_TRIGGERS
2433 trace_create_file("hist", 0444, file->dir, file,
2434 &event_hist_fops);
2435#endif
2436#ifdef CONFIG_HIST_TRIGGERS_DEBUG
2437 trace_create_file("hist_debug", 0444, file->dir, file,
2438 &event_hist_debug_fops);
2439#endif
2440 trace_create_file("format", 0444, file->dir, call,
2441 &ftrace_event_format_fops);
2442
2443#ifdef CONFIG_TRACE_EVENT_INJECT
2444 if (call->event.type && call->class->reg)
2445 trace_create_file("inject", 0200, file->dir, file,
2446 &event_inject_fops);
2447#endif
2448
2449 return 0;
2450}
2451
2452static void remove_event_from_tracers(struct trace_event_call *call)
2453{
2454 struct trace_event_file *file;
2455 struct trace_array *tr;
2456
2457 do_for_each_event_file_safe(tr, file) {
2458 if (file->event_call != call)
2459 continue;
2460
2461 remove_event_file_dir(file);
2462 /*
2463 * The do_for_each_event_file_safe() is
2464 * a double loop. After finding the call for this
2465 * trace_array, we use break to jump to the next
2466 * trace_array.
2467 */
2468 break;
2469 } while_for_each_event_file();
2470}
2471
2472static void event_remove(struct trace_event_call *call)
2473{
2474 struct trace_array *tr;
2475 struct trace_event_file *file;
2476
2477 do_for_each_event_file(tr, file) {
2478 if (file->event_call != call)
2479 continue;
2480
2481 if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
2482 tr->clear_trace = true;
2483
2484 ftrace_event_enable_disable(file, 0);
2485 /*
2486 * The do_for_each_event_file() is
2487 * a double loop. After finding the call for this
2488 * trace_array, we use break to jump to the next
2489 * trace_array.
2490 */
2491 break;
2492 } while_for_each_event_file();
2493
2494 if (call->event.funcs)
2495 __unregister_trace_event(&call->event);
2496 remove_event_from_tracers(call);
2497 list_del(&call->list);
2498}
2499
2500static int event_init(struct trace_event_call *call)
2501{
2502 int ret = 0;
2503 const char *name;
2504
2505 name = trace_event_name(call);
2506 if (WARN_ON(!name))
2507 return -EINVAL;
2508
2509 if (call->class->raw_init) {
2510 ret = call->class->raw_init(call);
2511 if (ret < 0 && ret != -ENOSYS)
2512 pr_warn("Could not initialize trace events/%s\n", name);
2513 }
2514
2515 return ret;
2516}
2517
2518static int
2519__register_event(struct trace_event_call *call, struct module *mod)
2520{
2521 int ret;
2522
2523 ret = event_init(call);
2524 if (ret < 0)
2525 return ret;
2526
2527 list_add(&call->list, &ftrace_events);
2528 call->mod = mod;
2529
2530 return 0;
2531}
2532
2533static char *eval_replace(char *ptr, struct trace_eval_map *map, int len)
2534{
2535 int rlen;
2536 int elen;
2537
2538 /* Find the length of the eval value as a string */
2539 elen = snprintf(ptr, 0, "%ld", map->eval_value);
2540 /* Make sure there's enough room to replace the string with the value */
2541 if (len < elen)
2542 return NULL;
2543
2544 snprintf(ptr, elen + 1, "%ld", map->eval_value);
2545
2546 /* Get the rest of the string of ptr */
2547 rlen = strlen(ptr + len);
2548 memmove(ptr + elen, ptr + len, rlen);
2549 /* Make sure we end the new string */
2550 ptr[elen + rlen] = 0;
2551
2552 return ptr + elen;
2553}
2554
2555static void update_event_printk(struct trace_event_call *call,
2556 struct trace_eval_map *map)
2557{
2558 char *ptr;
2559 int quote = 0;
2560 int len = strlen(map->eval_string);
2561
2562 for (ptr = call->print_fmt; *ptr; ptr++) {
2563 if (*ptr == '\\') {
2564 ptr++;
2565 /* paranoid */
2566 if (!*ptr)
2567 break;
2568 continue;
2569 }
2570 if (*ptr == '"') {
2571 quote ^= 1;
2572 continue;
2573 }
2574 if (quote)
2575 continue;
2576 if (isdigit(*ptr)) {
2577 /* skip numbers */
2578 do {
2579 ptr++;
2580 /* Check for alpha chars like ULL */
2581 } while (isalnum(*ptr));
2582 if (!*ptr)
2583 break;
2584 /*
2585 * A number must have some kind of delimiter after
2586 * it, and we can ignore that too.
2587 */
2588 continue;
2589 }
2590 if (isalpha(*ptr) || *ptr == '_') {
2591 if (strncmp(map->eval_string, ptr, len) == 0 &&
2592 !isalnum(ptr[len]) && ptr[len] != '_') {
2593 ptr = eval_replace(ptr, map, len);
2594 /* enum/sizeof string smaller than value */
2595 if (WARN_ON_ONCE(!ptr))
2596 return;
2597 /*
2598 * No need to decrement here, as eval_replace()
2599 * returns the pointer to the character passed
2600 * the eval, and two evals can not be placed
2601 * back to back without something in between.
2602 * We can skip that something in between.
2603 */
2604 continue;
2605 }
2606 skip_more:
2607 do {
2608 ptr++;
2609 } while (isalnum(*ptr) || *ptr == '_');
2610 if (!*ptr)
2611 break;
2612 /*
2613 * If what comes after this variable is a '.' or
2614 * '->' then we can continue to ignore that string.
2615 */
2616 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2617 ptr += *ptr == '.' ? 1 : 2;
2618 if (!*ptr)
2619 break;
2620 goto skip_more;
2621 }
2622 /*
2623 * Once again, we can skip the delimiter that came
2624 * after the string.
2625 */
2626 continue;
2627 }
2628 }
2629}
2630
2631void trace_event_eval_update(struct trace_eval_map **map, int len)
2632{
2633 struct trace_event_call *call, *p;
2634 const char *last_system = NULL;
2635 bool first = false;
2636 int last_i;
2637 int i;
2638
2639 down_write(&trace_event_sem);
2640 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2641 /* events are usually grouped together with systems */
2642 if (!last_system || call->class->system != last_system) {
2643 first = true;
2644 last_i = 0;
2645 last_system = call->class->system;
2646 }
2647
2648 /*
2649 * Since calls are grouped by systems, the likelihood that the
2650 * next call in the iteration belongs to the same system as the
2651 * previous call is high. As an optimization, we skip searching
2652 * for a map[] that matches the call's system if the last call
2653 * was from the same system. That's what last_i is for. If the
2654 * call has the same system as the previous call, then last_i
2655 * will be the index of the first map[] that has a matching
2656 * system.
2657 */
2658 for (i = last_i; i < len; i++) {
2659 if (call->class->system == map[i]->system) {
2660 /* Save the first system if need be */
2661 if (first) {
2662 last_i = i;
2663 first = false;
2664 }
2665 update_event_printk(call, map[i]);
2666 }
2667 }
2668 }
2669 up_write(&trace_event_sem);
2670}
2671
2672static struct trace_event_file *
2673trace_create_new_event(struct trace_event_call *call,
2674 struct trace_array *tr)
2675{
2676 struct trace_event_file *file;
2677
2678 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2679 if (!file)
2680 return NULL;
2681
2682 file->event_call = call;
2683 file->tr = tr;
2684 atomic_set(&file->sm_ref, 0);
2685 atomic_set(&file->tm_ref, 0);
2686 INIT_LIST_HEAD(&file->triggers);
2687 list_add(&file->list, &tr->events);
2688
2689 return file;
2690}
2691
2692/* Add an event to a trace directory */
2693static int
2694__trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2695{
2696 struct trace_event_file *file;
2697
2698 file = trace_create_new_event(call, tr);
2699 if (!file)
2700 return -ENOMEM;
2701
2702 if (eventdir_initialized)
2703 return event_create_dir(tr->event_dir, file);
2704 else
2705 return event_define_fields(call);
2706}
2707
2708/*
2709 * Just create a descriptor for early init. A descriptor is required
2710 * for enabling events at boot. We want to enable events before
2711 * the filesystem is initialized.
2712 */
2713static int
2714__trace_early_add_new_event(struct trace_event_call *call,
2715 struct trace_array *tr)
2716{
2717 struct trace_event_file *file;
2718
2719 file = trace_create_new_event(call, tr);
2720 if (!file)
2721 return -ENOMEM;
2722
2723 return event_define_fields(call);
2724}
2725
2726struct ftrace_module_file_ops;
2727static void __add_event_to_tracers(struct trace_event_call *call);
2728
2729/* Add an additional event_call dynamically */
2730int trace_add_event_call(struct trace_event_call *call)
2731{
2732 int ret;
2733 lockdep_assert_held(&event_mutex);
2734
2735 mutex_lock(&trace_types_lock);
2736
2737 ret = __register_event(call, NULL);
2738 if (ret >= 0)
2739 __add_event_to_tracers(call);
2740
2741 mutex_unlock(&trace_types_lock);
2742 return ret;
2743}
2744
2745/*
2746 * Must be called under locking of trace_types_lock, event_mutex and
2747 * trace_event_sem.
2748 */
2749static void __trace_remove_event_call(struct trace_event_call *call)
2750{
2751 event_remove(call);
2752 trace_destroy_fields(call);
2753 free_event_filter(call->filter);
2754 call->filter = NULL;
2755}
2756
2757static int probe_remove_event_call(struct trace_event_call *call)
2758{
2759 struct trace_array *tr;
2760 struct trace_event_file *file;
2761
2762#ifdef CONFIG_PERF_EVENTS
2763 if (call->perf_refcount)
2764 return -EBUSY;
2765#endif
2766 do_for_each_event_file(tr, file) {
2767 if (file->event_call != call)
2768 continue;
2769 /*
2770 * We can't rely on ftrace_event_enable_disable(enable => 0)
2771 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2772 * TRACE_REG_UNREGISTER.
2773 */
2774 if (file->flags & EVENT_FILE_FL_ENABLED)
2775 return -EBUSY;
2776 /*
2777 * The do_for_each_event_file_safe() is
2778 * a double loop. After finding the call for this
2779 * trace_array, we use break to jump to the next
2780 * trace_array.
2781 */
2782 break;
2783 } while_for_each_event_file();
2784
2785 __trace_remove_event_call(call);
2786
2787 return 0;
2788}
2789
2790/* Remove an event_call */
2791int trace_remove_event_call(struct trace_event_call *call)
2792{
2793 int ret;
2794
2795 lockdep_assert_held(&event_mutex);
2796
2797 mutex_lock(&trace_types_lock);
2798 down_write(&trace_event_sem);
2799 ret = probe_remove_event_call(call);
2800 up_write(&trace_event_sem);
2801 mutex_unlock(&trace_types_lock);
2802
2803 return ret;
2804}
2805
2806#define for_each_event(event, start, end) \
2807 for (event = start; \
2808 (unsigned long)event < (unsigned long)end; \
2809 event++)
2810
2811#ifdef CONFIG_MODULES
2812
2813static void trace_module_add_events(struct module *mod)
2814{
2815 struct trace_event_call **call, **start, **end;
2816
2817 if (!mod->num_trace_events)
2818 return;
2819
2820 /* Don't add infrastructure for mods without tracepoints */
2821 if (trace_module_has_bad_taint(mod)) {
2822 pr_err("%s: module has bad taint, not creating trace events\n",
2823 mod->name);
2824 return;
2825 }
2826
2827 start = mod->trace_events;
2828 end = mod->trace_events + mod->num_trace_events;
2829
2830 for_each_event(call, start, end) {
2831 __register_event(*call, mod);
2832 __add_event_to_tracers(*call);
2833 }
2834}
2835
2836static void trace_module_remove_events(struct module *mod)
2837{
2838 struct trace_event_call *call, *p;
2839
2840 down_write(&trace_event_sem);
2841 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2842 if (call->mod == mod)
2843 __trace_remove_event_call(call);
2844 }
2845 up_write(&trace_event_sem);
2846
2847 /*
2848 * It is safest to reset the ring buffer if the module being unloaded
2849 * registered any events that were used. The only worry is if
2850 * a new module gets loaded, and takes on the same id as the events
2851 * of this module. When printing out the buffer, traced events left
2852 * over from this module may be passed to the new module events and
2853 * unexpected results may occur.
2854 */
2855 tracing_reset_all_online_cpus();
2856}
2857
2858static int trace_module_notify(struct notifier_block *self,
2859 unsigned long val, void *data)
2860{
2861 struct module *mod = data;
2862
2863 mutex_lock(&event_mutex);
2864 mutex_lock(&trace_types_lock);
2865 switch (val) {
2866 case MODULE_STATE_COMING:
2867 trace_module_add_events(mod);
2868 break;
2869 case MODULE_STATE_GOING:
2870 trace_module_remove_events(mod);
2871 break;
2872 }
2873 mutex_unlock(&trace_types_lock);
2874 mutex_unlock(&event_mutex);
2875
2876 return NOTIFY_OK;
2877}
2878
2879static struct notifier_block trace_module_nb = {
2880 .notifier_call = trace_module_notify,
2881 .priority = 1, /* higher than trace.c module notify */
2882};
2883#endif /* CONFIG_MODULES */
2884
2885/* Create a new event directory structure for a trace directory. */
2886static void
2887__trace_add_event_dirs(struct trace_array *tr)
2888{
2889 struct trace_event_call *call;
2890 int ret;
2891
2892 list_for_each_entry(call, &ftrace_events, list) {
2893 ret = __trace_add_new_event(call, tr);
2894 if (ret < 0)
2895 pr_warn("Could not create directory for event %s\n",
2896 trace_event_name(call));
2897 }
2898}
2899
2900/* Returns any file that matches the system and event */
2901struct trace_event_file *
2902__find_event_file(struct trace_array *tr, const char *system, const char *event)
2903{
2904 struct trace_event_file *file;
2905 struct trace_event_call *call;
2906 const char *name;
2907
2908 list_for_each_entry(file, &tr->events, list) {
2909
2910 call = file->event_call;
2911 name = trace_event_name(call);
2912
2913 if (!name || !call->class)
2914 continue;
2915
2916 if (strcmp(event, name) == 0 &&
2917 strcmp(system, call->class->system) == 0)
2918 return file;
2919 }
2920 return NULL;
2921}
2922
2923/* Returns valid trace event files that match system and event */
2924struct trace_event_file *
2925find_event_file(struct trace_array *tr, const char *system, const char *event)
2926{
2927 struct trace_event_file *file;
2928
2929 file = __find_event_file(tr, system, event);
2930 if (!file || !file->event_call->class->reg ||
2931 file->event_call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2932 return NULL;
2933
2934 return file;
2935}
2936
2937/**
2938 * trace_get_event_file - Find and return a trace event file
2939 * @instance: The name of the trace instance containing the event
2940 * @system: The name of the system containing the event
2941 * @event: The name of the event
2942 *
2943 * Return a trace event file given the trace instance name, trace
2944 * system, and trace event name. If the instance name is NULL, it
2945 * refers to the top-level trace array.
2946 *
2947 * This function will look it up and return it if found, after calling
2948 * trace_array_get() to prevent the instance from going away, and
2949 * increment the event's module refcount to prevent it from being
2950 * removed.
2951 *
2952 * To release the file, call trace_put_event_file(), which will call
2953 * trace_array_put() and decrement the event's module refcount.
2954 *
2955 * Return: The trace event on success, ERR_PTR otherwise.
2956 */
2957struct trace_event_file *trace_get_event_file(const char *instance,
2958 const char *system,
2959 const char *event)
2960{
2961 struct trace_array *tr = top_trace_array();
2962 struct trace_event_file *file = NULL;
2963 int ret = -EINVAL;
2964
2965 if (instance) {
2966 tr = trace_array_find_get(instance);
2967 if (!tr)
2968 return ERR_PTR(-ENOENT);
2969 } else {
2970 ret = trace_array_get(tr);
2971 if (ret)
2972 return ERR_PTR(ret);
2973 }
2974
2975 mutex_lock(&event_mutex);
2976
2977 file = find_event_file(tr, system, event);
2978 if (!file) {
2979 trace_array_put(tr);
2980 ret = -EINVAL;
2981 goto out;
2982 }
2983
2984 /* Don't let event modules unload while in use */
2985 ret = try_module_get(file->event_call->mod);
2986 if (!ret) {
2987 trace_array_put(tr);
2988 ret = -EBUSY;
2989 goto out;
2990 }
2991
2992 ret = 0;
2993 out:
2994 mutex_unlock(&event_mutex);
2995
2996 if (ret)
2997 file = ERR_PTR(ret);
2998
2999 return file;
3000}
3001EXPORT_SYMBOL_GPL(trace_get_event_file);
3002
3003/**
3004 * trace_put_event_file - Release a file from trace_get_event_file()
3005 * @file: The trace event file
3006 *
3007 * If a file was retrieved using trace_get_event_file(), this should
3008 * be called when it's no longer needed. It will cancel the previous
3009 * trace_array_get() called by that function, and decrement the
3010 * event's module refcount.
3011 */
3012void trace_put_event_file(struct trace_event_file *file)
3013{
3014 mutex_lock(&event_mutex);
3015 module_put(file->event_call->mod);
3016 mutex_unlock(&event_mutex);
3017
3018 trace_array_put(file->tr);
3019}
3020EXPORT_SYMBOL_GPL(trace_put_event_file);
3021
3022#ifdef CONFIG_DYNAMIC_FTRACE
3023
3024/* Avoid typos */
3025#define ENABLE_EVENT_STR "enable_event"
3026#define DISABLE_EVENT_STR "disable_event"
3027
3028struct event_probe_data {
3029 struct trace_event_file *file;
3030 unsigned long count;
3031 int ref;
3032 bool enable;
3033};
3034
3035static void update_event_probe(struct event_probe_data *data)
3036{
3037 if (data->enable)
3038 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
3039 else
3040 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
3041}
3042
3043static void
3044event_enable_probe(unsigned long ip, unsigned long parent_ip,
3045 struct trace_array *tr, struct ftrace_probe_ops *ops,
3046 void *data)
3047{
3048 struct ftrace_func_mapper *mapper = data;
3049 struct event_probe_data *edata;
3050 void **pdata;
3051
3052 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3053 if (!pdata || !*pdata)
3054 return;
3055
3056 edata = *pdata;
3057 update_event_probe(edata);
3058}
3059
3060static void
3061event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
3062 struct trace_array *tr, struct ftrace_probe_ops *ops,
3063 void *data)
3064{
3065 struct ftrace_func_mapper *mapper = data;
3066 struct event_probe_data *edata;
3067 void **pdata;
3068
3069 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3070 if (!pdata || !*pdata)
3071 return;
3072
3073 edata = *pdata;
3074
3075 if (!edata->count)
3076 return;
3077
3078 /* Skip if the event is in a state we want to switch to */
3079 if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
3080 return;
3081
3082 if (edata->count != -1)
3083 (edata->count)--;
3084
3085 update_event_probe(edata);
3086}
3087
3088static int
3089event_enable_print(struct seq_file *m, unsigned long ip,
3090 struct ftrace_probe_ops *ops, void *data)
3091{
3092 struct ftrace_func_mapper *mapper = data;
3093 struct event_probe_data *edata;
3094 void **pdata;
3095
3096 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3097
3098 if (WARN_ON_ONCE(!pdata || !*pdata))
3099 return 0;
3100
3101 edata = *pdata;
3102
3103 seq_printf(m, "%ps:", (void *)ip);
3104
3105 seq_printf(m, "%s:%s:%s",
3106 edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
3107 edata->file->event_call->class->system,
3108 trace_event_name(edata->file->event_call));
3109
3110 if (edata->count == -1)
3111 seq_puts(m, ":unlimited\n");
3112 else
3113 seq_printf(m, ":count=%ld\n", edata->count);
3114
3115 return 0;
3116}
3117
3118static int
3119event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
3120 unsigned long ip, void *init_data, void **data)
3121{
3122 struct ftrace_func_mapper *mapper = *data;
3123 struct event_probe_data *edata = init_data;
3124 int ret;
3125
3126 if (!mapper) {
3127 mapper = allocate_ftrace_func_mapper();
3128 if (!mapper)
3129 return -ENODEV;
3130 *data = mapper;
3131 }
3132
3133 ret = ftrace_func_mapper_add_ip(mapper, ip, edata);
3134 if (ret < 0)
3135 return ret;
3136
3137 edata->ref++;
3138
3139 return 0;
3140}
3141
3142static int free_probe_data(void *data)
3143{
3144 struct event_probe_data *edata = data;
3145
3146 edata->ref--;
3147 if (!edata->ref) {
3148 /* Remove the SOFT_MODE flag */
3149 __ftrace_event_enable_disable(edata->file, 0, 1);
3150 module_put(edata->file->event_call->mod);
3151 kfree(edata);
3152 }
3153 return 0;
3154}
3155
3156static void
3157event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
3158 unsigned long ip, void *data)
3159{
3160 struct ftrace_func_mapper *mapper = data;
3161 struct event_probe_data *edata;
3162
3163 if (!ip) {
3164 if (!mapper)
3165 return;
3166 free_ftrace_func_mapper(mapper, free_probe_data);
3167 return;
3168 }
3169
3170 edata = ftrace_func_mapper_remove_ip(mapper, ip);
3171
3172 if (WARN_ON_ONCE(!edata))
3173 return;
3174
3175 if (WARN_ON_ONCE(edata->ref <= 0))
3176 return;
3177
3178 free_probe_data(edata);
3179}
3180
3181static struct ftrace_probe_ops event_enable_probe_ops = {
3182 .func = event_enable_probe,
3183 .print = event_enable_print,
3184 .init = event_enable_init,
3185 .free = event_enable_free,
3186};
3187
3188static struct ftrace_probe_ops event_enable_count_probe_ops = {
3189 .func = event_enable_count_probe,
3190 .print = event_enable_print,
3191 .init = event_enable_init,
3192 .free = event_enable_free,
3193};
3194
3195static struct ftrace_probe_ops event_disable_probe_ops = {
3196 .func = event_enable_probe,
3197 .print = event_enable_print,
3198 .init = event_enable_init,
3199 .free = event_enable_free,
3200};
3201
3202static struct ftrace_probe_ops event_disable_count_probe_ops = {
3203 .func = event_enable_count_probe,
3204 .print = event_enable_print,
3205 .init = event_enable_init,
3206 .free = event_enable_free,
3207};
3208
3209static int
3210event_enable_func(struct trace_array *tr, struct ftrace_hash *hash,
3211 char *glob, char *cmd, char *param, int enabled)
3212{
3213 struct trace_event_file *file;
3214 struct ftrace_probe_ops *ops;
3215 struct event_probe_data *data;
3216 const char *system;
3217 const char *event;
3218 char *number;
3219 bool enable;
3220 int ret;
3221
3222 if (!tr)
3223 return -ENODEV;
3224
3225 /* hash funcs only work with set_ftrace_filter */
3226 if (!enabled || !param)
3227 return -EINVAL;
3228
3229 system = strsep(¶m, ":");
3230 if (!param)
3231 return -EINVAL;
3232
3233 event = strsep(¶m, ":");
3234
3235 mutex_lock(&event_mutex);
3236
3237 ret = -EINVAL;
3238 file = find_event_file(tr, system, event);
3239 if (!file)
3240 goto out;
3241
3242 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
3243
3244 if (enable)
3245 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
3246 else
3247 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
3248
3249 if (glob[0] == '!') {
3250 ret = unregister_ftrace_function_probe_func(glob+1, tr, ops);
3251 goto out;
3252 }
3253
3254 ret = -ENOMEM;
3255
3256 data = kzalloc(sizeof(*data), GFP_KERNEL);
3257 if (!data)
3258 goto out;
3259
3260 data->enable = enable;
3261 data->count = -1;
3262 data->file = file;
3263
3264 if (!param)
3265 goto out_reg;
3266
3267 number = strsep(¶m, ":");
3268
3269 ret = -EINVAL;
3270 if (!strlen(number))
3271 goto out_free;
3272
3273 /*
3274 * We use the callback data field (which is a pointer)
3275 * as our counter.
3276 */
3277 ret = kstrtoul(number, 0, &data->count);
3278 if (ret)
3279 goto out_free;
3280
3281 out_reg:
3282 /* Don't let event modules unload while probe registered */
3283 ret = try_module_get(file->event_call->mod);
3284 if (!ret) {
3285 ret = -EBUSY;
3286 goto out_free;
3287 }
3288
3289 ret = __ftrace_event_enable_disable(file, 1, 1);
3290 if (ret < 0)
3291 goto out_put;
3292
3293 ret = register_ftrace_function_probe(glob, tr, ops, data);
3294 /*
3295 * The above returns on success the # of functions enabled,
3296 * but if it didn't find any functions it returns zero.
3297 * Consider no functions a failure too.
3298 */
3299 if (!ret) {
3300 ret = -ENOENT;
3301 goto out_disable;
3302 } else if (ret < 0)
3303 goto out_disable;
3304 /* Just return zero, not the number of enabled functions */
3305 ret = 0;
3306 out:
3307 mutex_unlock(&event_mutex);
3308 return ret;
3309
3310 out_disable:
3311 __ftrace_event_enable_disable(file, 0, 1);
3312 out_put:
3313 module_put(file->event_call->mod);
3314 out_free:
3315 kfree(data);
3316 goto out;
3317}
3318
3319static struct ftrace_func_command event_enable_cmd = {
3320 .name = ENABLE_EVENT_STR,
3321 .func = event_enable_func,
3322};
3323
3324static struct ftrace_func_command event_disable_cmd = {
3325 .name = DISABLE_EVENT_STR,
3326 .func = event_enable_func,
3327};
3328
3329static __init int register_event_cmds(void)
3330{
3331 int ret;
3332
3333 ret = register_ftrace_command(&event_enable_cmd);
3334 if (WARN_ON(ret < 0))
3335 return ret;
3336 ret = register_ftrace_command(&event_disable_cmd);
3337 if (WARN_ON(ret < 0))
3338 unregister_ftrace_command(&event_enable_cmd);
3339 return ret;
3340}
3341#else
3342static inline int register_event_cmds(void) { return 0; }
3343#endif /* CONFIG_DYNAMIC_FTRACE */
3344
3345/*
3346 * The top level array and trace arrays created by boot-time tracing
3347 * have already had its trace_event_file descriptors created in order
3348 * to allow for early events to be recorded.
3349 * This function is called after the tracefs has been initialized,
3350 * and we now have to create the files associated to the events.
3351 */
3352static void __trace_early_add_event_dirs(struct trace_array *tr)
3353{
3354 struct trace_event_file *file;
3355 int ret;
3356
3357
3358 list_for_each_entry(file, &tr->events, list) {
3359 ret = event_create_dir(tr->event_dir, file);
3360 if (ret < 0)
3361 pr_warn("Could not create directory for event %s\n",
3362 trace_event_name(file->event_call));
3363 }
3364}
3365
3366/*
3367 * For early boot up, the top trace array and the trace arrays created
3368 * by boot-time tracing require to have a list of events that can be
3369 * enabled. This must be done before the filesystem is set up in order
3370 * to allow events to be traced early.
3371 */
3372void __trace_early_add_events(struct trace_array *tr)
3373{
3374 struct trace_event_call *call;
3375 int ret;
3376
3377 list_for_each_entry(call, &ftrace_events, list) {
3378 /* Early boot up should not have any modules loaded */
3379 if (WARN_ON_ONCE(call->mod))
3380 continue;
3381
3382 ret = __trace_early_add_new_event(call, tr);
3383 if (ret < 0)
3384 pr_warn("Could not create early event %s\n",
3385 trace_event_name(call));
3386 }
3387}
3388
3389/* Remove the event directory structure for a trace directory. */
3390static void
3391__trace_remove_event_dirs(struct trace_array *tr)
3392{
3393 struct trace_event_file *file, *next;
3394
3395 list_for_each_entry_safe(file, next, &tr->events, list)
3396 remove_event_file_dir(file);
3397}
3398
3399static void __add_event_to_tracers(struct trace_event_call *call)
3400{
3401 struct trace_array *tr;
3402
3403 list_for_each_entry(tr, &ftrace_trace_arrays, list)
3404 __trace_add_new_event(call, tr);
3405}
3406
3407extern struct trace_event_call *__start_ftrace_events[];
3408extern struct trace_event_call *__stop_ftrace_events[];
3409
3410static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
3411
3412static __init int setup_trace_event(char *str)
3413{
3414 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
3415 ring_buffer_expanded = true;
3416 disable_tracing_selftest("running event tracing");
3417
3418 return 1;
3419}
3420__setup("trace_event=", setup_trace_event);
3421
3422/* Expects to have event_mutex held when called */
3423static int
3424create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
3425{
3426 struct dentry *d_events;
3427 struct dentry *entry;
3428
3429 entry = tracefs_create_file("set_event", 0644, parent,
3430 tr, &ftrace_set_event_fops);
3431 if (!entry) {
3432 pr_warn("Could not create tracefs 'set_event' entry\n");
3433 return -ENOMEM;
3434 }
3435
3436 d_events = tracefs_create_dir("events", parent);
3437 if (!d_events) {
3438 pr_warn("Could not create tracefs 'events' directory\n");
3439 return -ENOMEM;
3440 }
3441
3442 entry = trace_create_file("enable", 0644, d_events,
3443 tr, &ftrace_tr_enable_fops);
3444 if (!entry) {
3445 pr_warn("Could not create tracefs 'enable' entry\n");
3446 return -ENOMEM;
3447 }
3448
3449 /* There are not as crucial, just warn if they are not created */
3450
3451 entry = tracefs_create_file("set_event_pid", 0644, parent,
3452 tr, &ftrace_set_event_pid_fops);
3453 if (!entry)
3454 pr_warn("Could not create tracefs 'set_event_pid' entry\n");
3455
3456 entry = tracefs_create_file("set_event_notrace_pid", 0644, parent,
3457 tr, &ftrace_set_event_notrace_pid_fops);
3458 if (!entry)
3459 pr_warn("Could not create tracefs 'set_event_notrace_pid' entry\n");
3460
3461 /* ring buffer internal formats */
3462 entry = trace_create_file("header_page", 0444, d_events,
3463 ring_buffer_print_page_header,
3464 &ftrace_show_header_fops);
3465 if (!entry)
3466 pr_warn("Could not create tracefs 'header_page' entry\n");
3467
3468 entry = trace_create_file("header_event", 0444, d_events,
3469 ring_buffer_print_entry_header,
3470 &ftrace_show_header_fops);
3471 if (!entry)
3472 pr_warn("Could not create tracefs 'header_event' entry\n");
3473
3474 tr->event_dir = d_events;
3475
3476 return 0;
3477}
3478
3479/**
3480 * event_trace_add_tracer - add a instance of a trace_array to events
3481 * @parent: The parent dentry to place the files/directories for events in
3482 * @tr: The trace array associated with these events
3483 *
3484 * When a new instance is created, it needs to set up its events
3485 * directory, as well as other files associated with events. It also
3486 * creates the event hierarchy in the @parent/events directory.
3487 *
3488 * Returns 0 on success.
3489 *
3490 * Must be called with event_mutex held.
3491 */
3492int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
3493{
3494 int ret;
3495
3496 lockdep_assert_held(&event_mutex);
3497
3498 ret = create_event_toplevel_files(parent, tr);
3499 if (ret)
3500 goto out;
3501
3502 down_write(&trace_event_sem);
3503 /* If tr already has the event list, it is initialized in early boot. */
3504 if (unlikely(!list_empty(&tr->events)))
3505 __trace_early_add_event_dirs(tr);
3506 else
3507 __trace_add_event_dirs(tr);
3508 up_write(&trace_event_sem);
3509
3510 out:
3511 return ret;
3512}
3513
3514/*
3515 * The top trace array already had its file descriptors created.
3516 * Now the files themselves need to be created.
3517 */
3518static __init int
3519early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
3520{
3521 int ret;
3522
3523 mutex_lock(&event_mutex);
3524
3525 ret = create_event_toplevel_files(parent, tr);
3526 if (ret)
3527 goto out_unlock;
3528
3529 down_write(&trace_event_sem);
3530 __trace_early_add_event_dirs(tr);
3531 up_write(&trace_event_sem);
3532
3533 out_unlock:
3534 mutex_unlock(&event_mutex);
3535
3536 return ret;
3537}
3538
3539/* Must be called with event_mutex held */
3540int event_trace_del_tracer(struct trace_array *tr)
3541{
3542 lockdep_assert_held(&event_mutex);
3543
3544 /* Disable any event triggers and associated soft-disabled events */
3545 clear_event_triggers(tr);
3546
3547 /* Clear the pid list */
3548 __ftrace_clear_event_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
3549
3550 /* Disable any running events */
3551 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3552
3553 /* Make sure no more events are being executed */
3554 tracepoint_synchronize_unregister();
3555
3556 down_write(&trace_event_sem);
3557 __trace_remove_event_dirs(tr);
3558 tracefs_remove(tr->event_dir);
3559 up_write(&trace_event_sem);
3560
3561 tr->event_dir = NULL;
3562
3563 return 0;
3564}
3565
3566static __init int event_trace_memsetup(void)
3567{
3568 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3569 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3570 return 0;
3571}
3572
3573static __init void
3574early_enable_events(struct trace_array *tr, bool disable_first)
3575{
3576 char *buf = bootup_event_buf;
3577 char *token;
3578 int ret;
3579
3580 while (true) {
3581 token = strsep(&buf, ",");
3582
3583 if (!token)
3584 break;
3585
3586 if (*token) {
3587 /* Restarting syscalls requires that we stop them first */
3588 if (disable_first)
3589 ftrace_set_clr_event(tr, token, 0);
3590
3591 ret = ftrace_set_clr_event(tr, token, 1);
3592 if (ret)
3593 pr_warn("Failed to enable trace event: %s\n", token);
3594 }
3595
3596 /* Put back the comma to allow this to be called again */
3597 if (buf)
3598 *(buf - 1) = ',';
3599 }
3600}
3601
3602static __init int event_trace_enable(void)
3603{
3604 struct trace_array *tr = top_trace_array();
3605 struct trace_event_call **iter, *call;
3606 int ret;
3607
3608 if (!tr)
3609 return -ENODEV;
3610
3611 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3612
3613 call = *iter;
3614 ret = event_init(call);
3615 if (!ret)
3616 list_add(&call->list, &ftrace_events);
3617 }
3618
3619 /*
3620 * We need the top trace array to have a working set of trace
3621 * points at early init, before the debug files and directories
3622 * are created. Create the file entries now, and attach them
3623 * to the actual file dentries later.
3624 */
3625 __trace_early_add_events(tr);
3626
3627 early_enable_events(tr, false);
3628
3629 trace_printk_start_comm();
3630
3631 register_event_cmds();
3632
3633 register_trigger_cmds();
3634
3635 return 0;
3636}
3637
3638/*
3639 * event_trace_enable() is called from trace_event_init() first to
3640 * initialize events and perhaps start any events that are on the
3641 * command line. Unfortunately, there are some events that will not
3642 * start this early, like the system call tracepoints that need
3643 * to set the %SYSCALL_WORK_SYSCALL_TRACEPOINT flag of pid 1. But
3644 * event_trace_enable() is called before pid 1 starts, and this flag
3645 * is never set, making the syscall tracepoint never get reached, but
3646 * the event is enabled regardless (and not doing anything).
3647 */
3648static __init int event_trace_enable_again(void)
3649{
3650 struct trace_array *tr;
3651
3652 tr = top_trace_array();
3653 if (!tr)
3654 return -ENODEV;
3655
3656 early_enable_events(tr, true);
3657
3658 return 0;
3659}
3660
3661early_initcall(event_trace_enable_again);
3662
3663/* Init fields which doesn't related to the tracefs */
3664static __init int event_trace_init_fields(void)
3665{
3666 if (trace_define_generic_fields())
3667 pr_warn("tracing: Failed to allocated generic fields");
3668
3669 if (trace_define_common_fields())
3670 pr_warn("tracing: Failed to allocate common fields");
3671
3672 return 0;
3673}
3674
3675__init int event_trace_init(void)
3676{
3677 struct trace_array *tr;
3678 struct dentry *entry;
3679 int ret;
3680
3681 tr = top_trace_array();
3682 if (!tr)
3683 return -ENODEV;
3684
3685 entry = tracefs_create_file("available_events", 0444, NULL,
3686 tr, &ftrace_avail_fops);
3687 if (!entry)
3688 pr_warn("Could not create tracefs 'available_events' entry\n");
3689
3690 ret = early_event_add_tracer(NULL, tr);
3691 if (ret)
3692 return ret;
3693
3694#ifdef CONFIG_MODULES
3695 ret = register_module_notifier(&trace_module_nb);
3696 if (ret)
3697 pr_warn("Failed to register trace events module notifier\n");
3698#endif
3699
3700 eventdir_initialized = true;
3701
3702 return 0;
3703}
3704
3705void __init trace_event_init(void)
3706{
3707 event_trace_memsetup();
3708 init_ftrace_syscalls();
3709 event_trace_enable();
3710 event_trace_init_fields();
3711}
3712
3713#ifdef CONFIG_EVENT_TRACE_STARTUP_TEST
3714
3715static DEFINE_SPINLOCK(test_spinlock);
3716static DEFINE_SPINLOCK(test_spinlock_irq);
3717static DEFINE_MUTEX(test_mutex);
3718
3719static __init void test_work(struct work_struct *dummy)
3720{
3721 spin_lock(&test_spinlock);
3722 spin_lock_irq(&test_spinlock_irq);
3723 udelay(1);
3724 spin_unlock_irq(&test_spinlock_irq);
3725 spin_unlock(&test_spinlock);
3726
3727 mutex_lock(&test_mutex);
3728 msleep(1);
3729 mutex_unlock(&test_mutex);
3730}
3731
3732static __init int event_test_thread(void *unused)
3733{
3734 void *test_malloc;
3735
3736 test_malloc = kmalloc(1234, GFP_KERNEL);
3737 if (!test_malloc)
3738 pr_info("failed to kmalloc\n");
3739
3740 schedule_on_each_cpu(test_work);
3741
3742 kfree(test_malloc);
3743
3744 set_current_state(TASK_INTERRUPTIBLE);
3745 while (!kthread_should_stop()) {
3746 schedule();
3747 set_current_state(TASK_INTERRUPTIBLE);
3748 }
3749 __set_current_state(TASK_RUNNING);
3750
3751 return 0;
3752}
3753
3754/*
3755 * Do various things that may trigger events.
3756 */
3757static __init void event_test_stuff(void)
3758{
3759 struct task_struct *test_thread;
3760
3761 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3762 msleep(1);
3763 kthread_stop(test_thread);
3764}
3765
3766/*
3767 * For every trace event defined, we will test each trace point separately,
3768 * and then by groups, and finally all trace points.
3769 */
3770static __init void event_trace_self_tests(void)
3771{
3772 struct trace_subsystem_dir *dir;
3773 struct trace_event_file *file;
3774 struct trace_event_call *call;
3775 struct event_subsystem *system;
3776 struct trace_array *tr;
3777 int ret;
3778
3779 tr = top_trace_array();
3780 if (!tr)
3781 return;
3782
3783 pr_info("Running tests on trace events:\n");
3784
3785 list_for_each_entry(file, &tr->events, list) {
3786
3787 call = file->event_call;
3788
3789 /* Only test those that have a probe */
3790 if (!call->class || !call->class->probe)
3791 continue;
3792
3793/*
3794 * Testing syscall events here is pretty useless, but
3795 * we still do it if configured. But this is time consuming.
3796 * What we really need is a user thread to perform the
3797 * syscalls as we test.
3798 */
3799#ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3800 if (call->class->system &&
3801 strcmp(call->class->system, "syscalls") == 0)
3802 continue;
3803#endif
3804
3805 pr_info("Testing event %s: ", trace_event_name(call));
3806
3807 /*
3808 * If an event is already enabled, someone is using
3809 * it and the self test should not be on.
3810 */
3811 if (file->flags & EVENT_FILE_FL_ENABLED) {
3812 pr_warn("Enabled event during self test!\n");
3813 WARN_ON_ONCE(1);
3814 continue;
3815 }
3816
3817 ftrace_event_enable_disable(file, 1);
3818 event_test_stuff();
3819 ftrace_event_enable_disable(file, 0);
3820
3821 pr_cont("OK\n");
3822 }
3823
3824 /* Now test at the sub system level */
3825
3826 pr_info("Running tests on trace event systems:\n");
3827
3828 list_for_each_entry(dir, &tr->systems, list) {
3829
3830 system = dir->subsystem;
3831
3832 /* the ftrace system is special, skip it */
3833 if (strcmp(system->name, "ftrace") == 0)
3834 continue;
3835
3836 pr_info("Testing event system %s: ", system->name);
3837
3838 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3839 if (WARN_ON_ONCE(ret)) {
3840 pr_warn("error enabling system %s\n",
3841 system->name);
3842 continue;
3843 }
3844
3845 event_test_stuff();
3846
3847 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3848 if (WARN_ON_ONCE(ret)) {
3849 pr_warn("error disabling system %s\n",
3850 system->name);
3851 continue;
3852 }
3853
3854 pr_cont("OK\n");
3855 }
3856
3857 /* Test with all events enabled */
3858
3859 pr_info("Running tests on all trace events:\n");
3860 pr_info("Testing all events: ");
3861
3862 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3863 if (WARN_ON_ONCE(ret)) {
3864 pr_warn("error enabling all events\n");
3865 return;
3866 }
3867
3868 event_test_stuff();
3869
3870 /* reset sysname */
3871 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3872 if (WARN_ON_ONCE(ret)) {
3873 pr_warn("error disabling all events\n");
3874 return;
3875 }
3876
3877 pr_cont("OK\n");
3878}
3879
3880#ifdef CONFIG_FUNCTION_TRACER
3881
3882static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3883
3884static struct trace_event_file event_trace_file __initdata;
3885
3886static void __init
3887function_test_events_call(unsigned long ip, unsigned long parent_ip,
3888 struct ftrace_ops *op, struct ftrace_regs *regs)
3889{
3890 struct trace_buffer *buffer;
3891 struct ring_buffer_event *event;
3892 struct ftrace_entry *entry;
3893 unsigned int trace_ctx;
3894 long disabled;
3895 int cpu;
3896
3897 trace_ctx = tracing_gen_ctx();
3898 preempt_disable_notrace();
3899 cpu = raw_smp_processor_id();
3900 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3901
3902 if (disabled != 1)
3903 goto out;
3904
3905 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
3906 TRACE_FN, sizeof(*entry),
3907 trace_ctx);
3908 if (!event)
3909 goto out;
3910 entry = ring_buffer_event_data(event);
3911 entry->ip = ip;
3912 entry->parent_ip = parent_ip;
3913
3914 event_trigger_unlock_commit(&event_trace_file, buffer, event,
3915 entry, trace_ctx);
3916 out:
3917 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3918 preempt_enable_notrace();
3919}
3920
3921static struct ftrace_ops trace_ops __initdata =
3922{
3923 .func = function_test_events_call,
3924};
3925
3926static __init void event_trace_self_test_with_function(void)
3927{
3928 int ret;
3929
3930 event_trace_file.tr = top_trace_array();
3931 if (WARN_ON(!event_trace_file.tr))
3932 return;
3933
3934 ret = register_ftrace_function(&trace_ops);
3935 if (WARN_ON(ret < 0)) {
3936 pr_info("Failed to enable function tracer for event tests\n");
3937 return;
3938 }
3939 pr_info("Running tests again, along with the function tracer\n");
3940 event_trace_self_tests();
3941 unregister_ftrace_function(&trace_ops);
3942}
3943#else
3944static __init void event_trace_self_test_with_function(void)
3945{
3946}
3947#endif
3948
3949static __init int event_trace_self_tests_init(void)
3950{
3951 if (!tracing_selftest_disabled) {
3952 event_trace_self_tests();
3953 event_trace_self_test_with_function();
3954 }
3955
3956 return 0;
3957}
3958
3959late_initcall(event_trace_self_tests_init);
3960
3961#endif
1/*
2 * event tracer
3 *
4 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
5 *
6 * - Added format output of fields of the trace point.
7 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
8 *
9 */
10
11#include <linux/workqueue.h>
12#include <linux/spinlock.h>
13#include <linux/kthread.h>
14#include <linux/debugfs.h>
15#include <linux/uaccess.h>
16#include <linux/module.h>
17#include <linux/ctype.h>
18#include <linux/slab.h>
19#include <linux/delay.h>
20
21#include <asm/setup.h>
22
23#include "trace_output.h"
24
25#undef TRACE_SYSTEM
26#define TRACE_SYSTEM "TRACE_SYSTEM"
27
28DEFINE_MUTEX(event_mutex);
29
30LIST_HEAD(ftrace_events);
31static LIST_HEAD(ftrace_common_fields);
32
33#define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
34
35static struct kmem_cache *field_cachep;
36static struct kmem_cache *file_cachep;
37
38#define SYSTEM_FL_FREE_NAME (1 << 31)
39
40static inline int system_refcount(struct event_subsystem *system)
41{
42 return system->ref_count & ~SYSTEM_FL_FREE_NAME;
43}
44
45static int system_refcount_inc(struct event_subsystem *system)
46{
47 return (system->ref_count++) & ~SYSTEM_FL_FREE_NAME;
48}
49
50static int system_refcount_dec(struct event_subsystem *system)
51{
52 return (--system->ref_count) & ~SYSTEM_FL_FREE_NAME;
53}
54
55/* Double loops, do not use break, only goto's work */
56#define do_for_each_event_file(tr, file) \
57 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
58 list_for_each_entry(file, &tr->events, list)
59
60#define do_for_each_event_file_safe(tr, file) \
61 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
62 struct ftrace_event_file *___n; \
63 list_for_each_entry_safe(file, ___n, &tr->events, list)
64
65#define while_for_each_event_file() \
66 }
67
68static struct list_head *
69trace_get_fields(struct ftrace_event_call *event_call)
70{
71 if (!event_call->class->get_fields)
72 return &event_call->class->fields;
73 return event_call->class->get_fields(event_call);
74}
75
76static struct ftrace_event_field *
77__find_event_field(struct list_head *head, char *name)
78{
79 struct ftrace_event_field *field;
80
81 list_for_each_entry(field, head, link) {
82 if (!strcmp(field->name, name))
83 return field;
84 }
85
86 return NULL;
87}
88
89struct ftrace_event_field *
90trace_find_event_field(struct ftrace_event_call *call, char *name)
91{
92 struct ftrace_event_field *field;
93 struct list_head *head;
94
95 field = __find_event_field(&ftrace_common_fields, name);
96 if (field)
97 return field;
98
99 head = trace_get_fields(call);
100 return __find_event_field(head, name);
101}
102
103static int __trace_define_field(struct list_head *head, const char *type,
104 const char *name, int offset, int size,
105 int is_signed, int filter_type)
106{
107 struct ftrace_event_field *field;
108
109 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
110 if (!field)
111 return -ENOMEM;
112
113 field->name = name;
114 field->type = type;
115
116 if (filter_type == FILTER_OTHER)
117 field->filter_type = filter_assign_type(type);
118 else
119 field->filter_type = filter_type;
120
121 field->offset = offset;
122 field->size = size;
123 field->is_signed = is_signed;
124
125 list_add(&field->link, head);
126
127 return 0;
128}
129
130int trace_define_field(struct ftrace_event_call *call, const char *type,
131 const char *name, int offset, int size, int is_signed,
132 int filter_type)
133{
134 struct list_head *head;
135
136 if (WARN_ON(!call->class))
137 return 0;
138
139 head = trace_get_fields(call);
140 return __trace_define_field(head, type, name, offset, size,
141 is_signed, filter_type);
142}
143EXPORT_SYMBOL_GPL(trace_define_field);
144
145#define __common_field(type, item) \
146 ret = __trace_define_field(&ftrace_common_fields, #type, \
147 "common_" #item, \
148 offsetof(typeof(ent), item), \
149 sizeof(ent.item), \
150 is_signed_type(type), FILTER_OTHER); \
151 if (ret) \
152 return ret;
153
154static int trace_define_common_fields(void)
155{
156 int ret;
157 struct trace_entry ent;
158
159 __common_field(unsigned short, type);
160 __common_field(unsigned char, flags);
161 __common_field(unsigned char, preempt_count);
162 __common_field(int, pid);
163
164 return ret;
165}
166
167static void trace_destroy_fields(struct ftrace_event_call *call)
168{
169 struct ftrace_event_field *field, *next;
170 struct list_head *head;
171
172 head = trace_get_fields(call);
173 list_for_each_entry_safe(field, next, head, link) {
174 list_del(&field->link);
175 kmem_cache_free(field_cachep, field);
176 }
177}
178
179int trace_event_raw_init(struct ftrace_event_call *call)
180{
181 int id;
182
183 id = register_ftrace_event(&call->event);
184 if (!id)
185 return -ENODEV;
186
187 return 0;
188}
189EXPORT_SYMBOL_GPL(trace_event_raw_init);
190
191void *ftrace_event_buffer_reserve(struct ftrace_event_buffer *fbuffer,
192 struct ftrace_event_file *ftrace_file,
193 unsigned long len)
194{
195 struct ftrace_event_call *event_call = ftrace_file->event_call;
196
197 local_save_flags(fbuffer->flags);
198 fbuffer->pc = preempt_count();
199 fbuffer->ftrace_file = ftrace_file;
200
201 fbuffer->event =
202 trace_event_buffer_lock_reserve(&fbuffer->buffer, ftrace_file,
203 event_call->event.type, len,
204 fbuffer->flags, fbuffer->pc);
205 if (!fbuffer->event)
206 return NULL;
207
208 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
209 return fbuffer->entry;
210}
211EXPORT_SYMBOL_GPL(ftrace_event_buffer_reserve);
212
213void ftrace_event_buffer_commit(struct ftrace_event_buffer *fbuffer)
214{
215 event_trigger_unlock_commit(fbuffer->ftrace_file, fbuffer->buffer,
216 fbuffer->event, fbuffer->entry,
217 fbuffer->flags, fbuffer->pc);
218}
219EXPORT_SYMBOL_GPL(ftrace_event_buffer_commit);
220
221int ftrace_event_reg(struct ftrace_event_call *call,
222 enum trace_reg type, void *data)
223{
224 struct ftrace_event_file *file = data;
225
226 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
227 switch (type) {
228 case TRACE_REG_REGISTER:
229 return tracepoint_probe_register(call->tp,
230 call->class->probe,
231 file);
232 case TRACE_REG_UNREGISTER:
233 tracepoint_probe_unregister(call->tp,
234 call->class->probe,
235 file);
236 return 0;
237
238#ifdef CONFIG_PERF_EVENTS
239 case TRACE_REG_PERF_REGISTER:
240 return tracepoint_probe_register(call->tp,
241 call->class->perf_probe,
242 call);
243 case TRACE_REG_PERF_UNREGISTER:
244 tracepoint_probe_unregister(call->tp,
245 call->class->perf_probe,
246 call);
247 return 0;
248 case TRACE_REG_PERF_OPEN:
249 case TRACE_REG_PERF_CLOSE:
250 case TRACE_REG_PERF_ADD:
251 case TRACE_REG_PERF_DEL:
252 return 0;
253#endif
254 }
255 return 0;
256}
257EXPORT_SYMBOL_GPL(ftrace_event_reg);
258
259void trace_event_enable_cmd_record(bool enable)
260{
261 struct ftrace_event_file *file;
262 struct trace_array *tr;
263
264 mutex_lock(&event_mutex);
265 do_for_each_event_file(tr, file) {
266
267 if (!(file->flags & FTRACE_EVENT_FL_ENABLED))
268 continue;
269
270 if (enable) {
271 tracing_start_cmdline_record();
272 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
273 } else {
274 tracing_stop_cmdline_record();
275 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
276 }
277 } while_for_each_event_file();
278 mutex_unlock(&event_mutex);
279}
280
281static int __ftrace_event_enable_disable(struct ftrace_event_file *file,
282 int enable, int soft_disable)
283{
284 struct ftrace_event_call *call = file->event_call;
285 int ret = 0;
286 int disable;
287
288 switch (enable) {
289 case 0:
290 /*
291 * When soft_disable is set and enable is cleared, the sm_ref
292 * reference counter is decremented. If it reaches 0, we want
293 * to clear the SOFT_DISABLED flag but leave the event in the
294 * state that it was. That is, if the event was enabled and
295 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
296 * is set we do not want the event to be enabled before we
297 * clear the bit.
298 *
299 * When soft_disable is not set but the SOFT_MODE flag is,
300 * we do nothing. Do not disable the tracepoint, otherwise
301 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
302 */
303 if (soft_disable) {
304 if (atomic_dec_return(&file->sm_ref) > 0)
305 break;
306 disable = file->flags & FTRACE_EVENT_FL_SOFT_DISABLED;
307 clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
308 } else
309 disable = !(file->flags & FTRACE_EVENT_FL_SOFT_MODE);
310
311 if (disable && (file->flags & FTRACE_EVENT_FL_ENABLED)) {
312 clear_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
313 if (file->flags & FTRACE_EVENT_FL_RECORDED_CMD) {
314 tracing_stop_cmdline_record();
315 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
316 }
317 call->class->reg(call, TRACE_REG_UNREGISTER, file);
318 }
319 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
320 if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
321 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
322 else
323 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
324 break;
325 case 1:
326 /*
327 * When soft_disable is set and enable is set, we want to
328 * register the tracepoint for the event, but leave the event
329 * as is. That means, if the event was already enabled, we do
330 * nothing (but set SOFT_MODE). If the event is disabled, we
331 * set SOFT_DISABLED before enabling the event tracepoint, so
332 * it still seems to be disabled.
333 */
334 if (!soft_disable)
335 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
336 else {
337 if (atomic_inc_return(&file->sm_ref) > 1)
338 break;
339 set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
340 }
341
342 if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) {
343
344 /* Keep the event disabled, when going to SOFT_MODE. */
345 if (soft_disable)
346 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
347
348 if (trace_flags & TRACE_ITER_RECORD_CMD) {
349 tracing_start_cmdline_record();
350 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
351 }
352 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
353 if (ret) {
354 tracing_stop_cmdline_record();
355 pr_info("event trace: Could not enable event "
356 "%s\n", ftrace_event_name(call));
357 break;
358 }
359 set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
360
361 /* WAS_ENABLED gets set but never cleared. */
362 call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
363 }
364 break;
365 }
366
367 return ret;
368}
369
370int trace_event_enable_disable(struct ftrace_event_file *file,
371 int enable, int soft_disable)
372{
373 return __ftrace_event_enable_disable(file, enable, soft_disable);
374}
375
376static int ftrace_event_enable_disable(struct ftrace_event_file *file,
377 int enable)
378{
379 return __ftrace_event_enable_disable(file, enable, 0);
380}
381
382static void ftrace_clear_events(struct trace_array *tr)
383{
384 struct ftrace_event_file *file;
385
386 mutex_lock(&event_mutex);
387 list_for_each_entry(file, &tr->events, list) {
388 ftrace_event_enable_disable(file, 0);
389 }
390 mutex_unlock(&event_mutex);
391}
392
393static void __put_system(struct event_subsystem *system)
394{
395 struct event_filter *filter = system->filter;
396
397 WARN_ON_ONCE(system_refcount(system) == 0);
398 if (system_refcount_dec(system))
399 return;
400
401 list_del(&system->list);
402
403 if (filter) {
404 kfree(filter->filter_string);
405 kfree(filter);
406 }
407 if (system->ref_count & SYSTEM_FL_FREE_NAME)
408 kfree(system->name);
409 kfree(system);
410}
411
412static void __get_system(struct event_subsystem *system)
413{
414 WARN_ON_ONCE(system_refcount(system) == 0);
415 system_refcount_inc(system);
416}
417
418static void __get_system_dir(struct ftrace_subsystem_dir *dir)
419{
420 WARN_ON_ONCE(dir->ref_count == 0);
421 dir->ref_count++;
422 __get_system(dir->subsystem);
423}
424
425static void __put_system_dir(struct ftrace_subsystem_dir *dir)
426{
427 WARN_ON_ONCE(dir->ref_count == 0);
428 /* If the subsystem is about to be freed, the dir must be too */
429 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
430
431 __put_system(dir->subsystem);
432 if (!--dir->ref_count)
433 kfree(dir);
434}
435
436static void put_system(struct ftrace_subsystem_dir *dir)
437{
438 mutex_lock(&event_mutex);
439 __put_system_dir(dir);
440 mutex_unlock(&event_mutex);
441}
442
443static void remove_subsystem(struct ftrace_subsystem_dir *dir)
444{
445 if (!dir)
446 return;
447
448 if (!--dir->nr_events) {
449 debugfs_remove_recursive(dir->entry);
450 list_del(&dir->list);
451 __put_system_dir(dir);
452 }
453}
454
455static void remove_event_file_dir(struct ftrace_event_file *file)
456{
457 struct dentry *dir = file->dir;
458 struct dentry *child;
459
460 if (dir) {
461 spin_lock(&dir->d_lock); /* probably unneeded */
462 list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
463 if (child->d_inode) /* probably unneeded */
464 child->d_inode->i_private = NULL;
465 }
466 spin_unlock(&dir->d_lock);
467
468 debugfs_remove_recursive(dir);
469 }
470
471 list_del(&file->list);
472 remove_subsystem(file->system);
473 kmem_cache_free(file_cachep, file);
474}
475
476/*
477 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
478 */
479static int
480__ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
481 const char *sub, const char *event, int set)
482{
483 struct ftrace_event_file *file;
484 struct ftrace_event_call *call;
485 const char *name;
486 int ret = -EINVAL;
487
488 list_for_each_entry(file, &tr->events, list) {
489
490 call = file->event_call;
491 name = ftrace_event_name(call);
492
493 if (!name || !call->class || !call->class->reg)
494 continue;
495
496 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
497 continue;
498
499 if (match &&
500 strcmp(match, name) != 0 &&
501 strcmp(match, call->class->system) != 0)
502 continue;
503
504 if (sub && strcmp(sub, call->class->system) != 0)
505 continue;
506
507 if (event && strcmp(event, name) != 0)
508 continue;
509
510 ftrace_event_enable_disable(file, set);
511
512 ret = 0;
513 }
514
515 return ret;
516}
517
518static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
519 const char *sub, const char *event, int set)
520{
521 int ret;
522
523 mutex_lock(&event_mutex);
524 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
525 mutex_unlock(&event_mutex);
526
527 return ret;
528}
529
530static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
531{
532 char *event = NULL, *sub = NULL, *match;
533
534 /*
535 * The buf format can be <subsystem>:<event-name>
536 * *:<event-name> means any event by that name.
537 * :<event-name> is the same.
538 *
539 * <subsystem>:* means all events in that subsystem
540 * <subsystem>: means the same.
541 *
542 * <name> (no ':') means all events in a subsystem with
543 * the name <name> or any event that matches <name>
544 */
545
546 match = strsep(&buf, ":");
547 if (buf) {
548 sub = match;
549 event = buf;
550 match = NULL;
551
552 if (!strlen(sub) || strcmp(sub, "*") == 0)
553 sub = NULL;
554 if (!strlen(event) || strcmp(event, "*") == 0)
555 event = NULL;
556 }
557
558 return __ftrace_set_clr_event(tr, match, sub, event, set);
559}
560
561/**
562 * trace_set_clr_event - enable or disable an event
563 * @system: system name to match (NULL for any system)
564 * @event: event name to match (NULL for all events, within system)
565 * @set: 1 to enable, 0 to disable
566 *
567 * This is a way for other parts of the kernel to enable or disable
568 * event recording.
569 *
570 * Returns 0 on success, -EINVAL if the parameters do not match any
571 * registered events.
572 */
573int trace_set_clr_event(const char *system, const char *event, int set)
574{
575 struct trace_array *tr = top_trace_array();
576
577 return __ftrace_set_clr_event(tr, NULL, system, event, set);
578}
579EXPORT_SYMBOL_GPL(trace_set_clr_event);
580
581/* 128 should be much more than enough */
582#define EVENT_BUF_SIZE 127
583
584static ssize_t
585ftrace_event_write(struct file *file, const char __user *ubuf,
586 size_t cnt, loff_t *ppos)
587{
588 struct trace_parser parser;
589 struct seq_file *m = file->private_data;
590 struct trace_array *tr = m->private;
591 ssize_t read, ret;
592
593 if (!cnt)
594 return 0;
595
596 ret = tracing_update_buffers();
597 if (ret < 0)
598 return ret;
599
600 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
601 return -ENOMEM;
602
603 read = trace_get_user(&parser, ubuf, cnt, ppos);
604
605 if (read >= 0 && trace_parser_loaded((&parser))) {
606 int set = 1;
607
608 if (*parser.buffer == '!')
609 set = 0;
610
611 parser.buffer[parser.idx] = 0;
612
613 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
614 if (ret)
615 goto out_put;
616 }
617
618 ret = read;
619
620 out_put:
621 trace_parser_put(&parser);
622
623 return ret;
624}
625
626static void *
627t_next(struct seq_file *m, void *v, loff_t *pos)
628{
629 struct ftrace_event_file *file = v;
630 struct ftrace_event_call *call;
631 struct trace_array *tr = m->private;
632
633 (*pos)++;
634
635 list_for_each_entry_continue(file, &tr->events, list) {
636 call = file->event_call;
637 /*
638 * The ftrace subsystem is for showing formats only.
639 * They can not be enabled or disabled via the event files.
640 */
641 if (call->class && call->class->reg)
642 return file;
643 }
644
645 return NULL;
646}
647
648static void *t_start(struct seq_file *m, loff_t *pos)
649{
650 struct ftrace_event_file *file;
651 struct trace_array *tr = m->private;
652 loff_t l;
653
654 mutex_lock(&event_mutex);
655
656 file = list_entry(&tr->events, struct ftrace_event_file, list);
657 for (l = 0; l <= *pos; ) {
658 file = t_next(m, file, &l);
659 if (!file)
660 break;
661 }
662 return file;
663}
664
665static void *
666s_next(struct seq_file *m, void *v, loff_t *pos)
667{
668 struct ftrace_event_file *file = v;
669 struct trace_array *tr = m->private;
670
671 (*pos)++;
672
673 list_for_each_entry_continue(file, &tr->events, list) {
674 if (file->flags & FTRACE_EVENT_FL_ENABLED)
675 return file;
676 }
677
678 return NULL;
679}
680
681static void *s_start(struct seq_file *m, loff_t *pos)
682{
683 struct ftrace_event_file *file;
684 struct trace_array *tr = m->private;
685 loff_t l;
686
687 mutex_lock(&event_mutex);
688
689 file = list_entry(&tr->events, struct ftrace_event_file, list);
690 for (l = 0; l <= *pos; ) {
691 file = s_next(m, file, &l);
692 if (!file)
693 break;
694 }
695 return file;
696}
697
698static int t_show(struct seq_file *m, void *v)
699{
700 struct ftrace_event_file *file = v;
701 struct ftrace_event_call *call = file->event_call;
702
703 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
704 seq_printf(m, "%s:", call->class->system);
705 seq_printf(m, "%s\n", ftrace_event_name(call));
706
707 return 0;
708}
709
710static void t_stop(struct seq_file *m, void *p)
711{
712 mutex_unlock(&event_mutex);
713}
714
715static ssize_t
716event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
717 loff_t *ppos)
718{
719 struct ftrace_event_file *file;
720 unsigned long flags;
721 char buf[4] = "0";
722
723 mutex_lock(&event_mutex);
724 file = event_file_data(filp);
725 if (likely(file))
726 flags = file->flags;
727 mutex_unlock(&event_mutex);
728
729 if (!file)
730 return -ENODEV;
731
732 if (flags & FTRACE_EVENT_FL_ENABLED &&
733 !(flags & FTRACE_EVENT_FL_SOFT_DISABLED))
734 strcpy(buf, "1");
735
736 if (flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
737 flags & FTRACE_EVENT_FL_SOFT_MODE)
738 strcat(buf, "*");
739
740 strcat(buf, "\n");
741
742 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
743}
744
745static ssize_t
746event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
747 loff_t *ppos)
748{
749 struct ftrace_event_file *file;
750 unsigned long val;
751 int ret;
752
753 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
754 if (ret)
755 return ret;
756
757 ret = tracing_update_buffers();
758 if (ret < 0)
759 return ret;
760
761 switch (val) {
762 case 0:
763 case 1:
764 ret = -ENODEV;
765 mutex_lock(&event_mutex);
766 file = event_file_data(filp);
767 if (likely(file))
768 ret = ftrace_event_enable_disable(file, val);
769 mutex_unlock(&event_mutex);
770 break;
771
772 default:
773 return -EINVAL;
774 }
775
776 *ppos += cnt;
777
778 return ret ? ret : cnt;
779}
780
781static ssize_t
782system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
783 loff_t *ppos)
784{
785 const char set_to_char[4] = { '?', '0', '1', 'X' };
786 struct ftrace_subsystem_dir *dir = filp->private_data;
787 struct event_subsystem *system = dir->subsystem;
788 struct ftrace_event_call *call;
789 struct ftrace_event_file *file;
790 struct trace_array *tr = dir->tr;
791 char buf[2];
792 int set = 0;
793 int ret;
794
795 mutex_lock(&event_mutex);
796 list_for_each_entry(file, &tr->events, list) {
797 call = file->event_call;
798 if (!ftrace_event_name(call) || !call->class || !call->class->reg)
799 continue;
800
801 if (system && strcmp(call->class->system, system->name) != 0)
802 continue;
803
804 /*
805 * We need to find out if all the events are set
806 * or if all events or cleared, or if we have
807 * a mixture.
808 */
809 set |= (1 << !!(file->flags & FTRACE_EVENT_FL_ENABLED));
810
811 /*
812 * If we have a mixture, no need to look further.
813 */
814 if (set == 3)
815 break;
816 }
817 mutex_unlock(&event_mutex);
818
819 buf[0] = set_to_char[set];
820 buf[1] = '\n';
821
822 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
823
824 return ret;
825}
826
827static ssize_t
828system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
829 loff_t *ppos)
830{
831 struct ftrace_subsystem_dir *dir = filp->private_data;
832 struct event_subsystem *system = dir->subsystem;
833 const char *name = NULL;
834 unsigned long val;
835 ssize_t ret;
836
837 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
838 if (ret)
839 return ret;
840
841 ret = tracing_update_buffers();
842 if (ret < 0)
843 return ret;
844
845 if (val != 0 && val != 1)
846 return -EINVAL;
847
848 /*
849 * Opening of "enable" adds a ref count to system,
850 * so the name is safe to use.
851 */
852 if (system)
853 name = system->name;
854
855 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
856 if (ret)
857 goto out;
858
859 ret = cnt;
860
861out:
862 *ppos += cnt;
863
864 return ret;
865}
866
867enum {
868 FORMAT_HEADER = 1,
869 FORMAT_FIELD_SEPERATOR = 2,
870 FORMAT_PRINTFMT = 3,
871};
872
873static void *f_next(struct seq_file *m, void *v, loff_t *pos)
874{
875 struct ftrace_event_call *call = event_file_data(m->private);
876 struct list_head *common_head = &ftrace_common_fields;
877 struct list_head *head = trace_get_fields(call);
878 struct list_head *node = v;
879
880 (*pos)++;
881
882 switch ((unsigned long)v) {
883 case FORMAT_HEADER:
884 node = common_head;
885 break;
886
887 case FORMAT_FIELD_SEPERATOR:
888 node = head;
889 break;
890
891 case FORMAT_PRINTFMT:
892 /* all done */
893 return NULL;
894 }
895
896 node = node->prev;
897 if (node == common_head)
898 return (void *)FORMAT_FIELD_SEPERATOR;
899 else if (node == head)
900 return (void *)FORMAT_PRINTFMT;
901 else
902 return node;
903}
904
905static int f_show(struct seq_file *m, void *v)
906{
907 struct ftrace_event_call *call = event_file_data(m->private);
908 struct ftrace_event_field *field;
909 const char *array_descriptor;
910
911 switch ((unsigned long)v) {
912 case FORMAT_HEADER:
913 seq_printf(m, "name: %s\n", ftrace_event_name(call));
914 seq_printf(m, "ID: %d\n", call->event.type);
915 seq_printf(m, "format:\n");
916 return 0;
917
918 case FORMAT_FIELD_SEPERATOR:
919 seq_putc(m, '\n');
920 return 0;
921
922 case FORMAT_PRINTFMT:
923 seq_printf(m, "\nprint fmt: %s\n",
924 call->print_fmt);
925 return 0;
926 }
927
928 field = list_entry(v, struct ftrace_event_field, link);
929 /*
930 * Smartly shows the array type(except dynamic array).
931 * Normal:
932 * field:TYPE VAR
933 * If TYPE := TYPE[LEN], it is shown:
934 * field:TYPE VAR[LEN]
935 */
936 array_descriptor = strchr(field->type, '[');
937
938 if (!strncmp(field->type, "__data_loc", 10))
939 array_descriptor = NULL;
940
941 if (!array_descriptor)
942 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
943 field->type, field->name, field->offset,
944 field->size, !!field->is_signed);
945 else
946 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
947 (int)(array_descriptor - field->type),
948 field->type, field->name,
949 array_descriptor, field->offset,
950 field->size, !!field->is_signed);
951
952 return 0;
953}
954
955static void *f_start(struct seq_file *m, loff_t *pos)
956{
957 void *p = (void *)FORMAT_HEADER;
958 loff_t l = 0;
959
960 /* ->stop() is called even if ->start() fails */
961 mutex_lock(&event_mutex);
962 if (!event_file_data(m->private))
963 return ERR_PTR(-ENODEV);
964
965 while (l < *pos && p)
966 p = f_next(m, p, &l);
967
968 return p;
969}
970
971static void f_stop(struct seq_file *m, void *p)
972{
973 mutex_unlock(&event_mutex);
974}
975
976static const struct seq_operations trace_format_seq_ops = {
977 .start = f_start,
978 .next = f_next,
979 .stop = f_stop,
980 .show = f_show,
981};
982
983static int trace_format_open(struct inode *inode, struct file *file)
984{
985 struct seq_file *m;
986 int ret;
987
988 ret = seq_open(file, &trace_format_seq_ops);
989 if (ret < 0)
990 return ret;
991
992 m = file->private_data;
993 m->private = file;
994
995 return 0;
996}
997
998static ssize_t
999event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1000{
1001 int id = (long)event_file_data(filp);
1002 char buf[32];
1003 int len;
1004
1005 if (*ppos)
1006 return 0;
1007
1008 if (unlikely(!id))
1009 return -ENODEV;
1010
1011 len = sprintf(buf, "%d\n", id);
1012
1013 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1014}
1015
1016static ssize_t
1017event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1018 loff_t *ppos)
1019{
1020 struct ftrace_event_file *file;
1021 struct trace_seq *s;
1022 int r = -ENODEV;
1023
1024 if (*ppos)
1025 return 0;
1026
1027 s = kmalloc(sizeof(*s), GFP_KERNEL);
1028
1029 if (!s)
1030 return -ENOMEM;
1031
1032 trace_seq_init(s);
1033
1034 mutex_lock(&event_mutex);
1035 file = event_file_data(filp);
1036 if (file)
1037 print_event_filter(file, s);
1038 mutex_unlock(&event_mutex);
1039
1040 if (file)
1041 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1042
1043 kfree(s);
1044
1045 return r;
1046}
1047
1048static ssize_t
1049event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1050 loff_t *ppos)
1051{
1052 struct ftrace_event_file *file;
1053 char *buf;
1054 int err = -ENODEV;
1055
1056 if (cnt >= PAGE_SIZE)
1057 return -EINVAL;
1058
1059 buf = (char *)__get_free_page(GFP_TEMPORARY);
1060 if (!buf)
1061 return -ENOMEM;
1062
1063 if (copy_from_user(buf, ubuf, cnt)) {
1064 free_page((unsigned long) buf);
1065 return -EFAULT;
1066 }
1067 buf[cnt] = '\0';
1068
1069 mutex_lock(&event_mutex);
1070 file = event_file_data(filp);
1071 if (file)
1072 err = apply_event_filter(file, buf);
1073 mutex_unlock(&event_mutex);
1074
1075 free_page((unsigned long) buf);
1076 if (err < 0)
1077 return err;
1078
1079 *ppos += cnt;
1080
1081 return cnt;
1082}
1083
1084static LIST_HEAD(event_subsystems);
1085
1086static int subsystem_open(struct inode *inode, struct file *filp)
1087{
1088 struct event_subsystem *system = NULL;
1089 struct ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1090 struct trace_array *tr;
1091 int ret;
1092
1093 if (tracing_is_disabled())
1094 return -ENODEV;
1095
1096 /* Make sure the system still exists */
1097 mutex_lock(&trace_types_lock);
1098 mutex_lock(&event_mutex);
1099 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1100 list_for_each_entry(dir, &tr->systems, list) {
1101 if (dir == inode->i_private) {
1102 /* Don't open systems with no events */
1103 if (dir->nr_events) {
1104 __get_system_dir(dir);
1105 system = dir->subsystem;
1106 }
1107 goto exit_loop;
1108 }
1109 }
1110 }
1111 exit_loop:
1112 mutex_unlock(&event_mutex);
1113 mutex_unlock(&trace_types_lock);
1114
1115 if (!system)
1116 return -ENODEV;
1117
1118 /* Some versions of gcc think dir can be uninitialized here */
1119 WARN_ON(!dir);
1120
1121 /* Still need to increment the ref count of the system */
1122 if (trace_array_get(tr) < 0) {
1123 put_system(dir);
1124 return -ENODEV;
1125 }
1126
1127 ret = tracing_open_generic(inode, filp);
1128 if (ret < 0) {
1129 trace_array_put(tr);
1130 put_system(dir);
1131 }
1132
1133 return ret;
1134}
1135
1136static int system_tr_open(struct inode *inode, struct file *filp)
1137{
1138 struct ftrace_subsystem_dir *dir;
1139 struct trace_array *tr = inode->i_private;
1140 int ret;
1141
1142 if (tracing_is_disabled())
1143 return -ENODEV;
1144
1145 if (trace_array_get(tr) < 0)
1146 return -ENODEV;
1147
1148 /* Make a temporary dir that has no system but points to tr */
1149 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1150 if (!dir) {
1151 trace_array_put(tr);
1152 return -ENOMEM;
1153 }
1154
1155 dir->tr = tr;
1156
1157 ret = tracing_open_generic(inode, filp);
1158 if (ret < 0) {
1159 trace_array_put(tr);
1160 kfree(dir);
1161 return ret;
1162 }
1163
1164 filp->private_data = dir;
1165
1166 return 0;
1167}
1168
1169static int subsystem_release(struct inode *inode, struct file *file)
1170{
1171 struct ftrace_subsystem_dir *dir = file->private_data;
1172
1173 trace_array_put(dir->tr);
1174
1175 /*
1176 * If dir->subsystem is NULL, then this is a temporary
1177 * descriptor that was made for a trace_array to enable
1178 * all subsystems.
1179 */
1180 if (dir->subsystem)
1181 put_system(dir);
1182 else
1183 kfree(dir);
1184
1185 return 0;
1186}
1187
1188static ssize_t
1189subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1190 loff_t *ppos)
1191{
1192 struct ftrace_subsystem_dir *dir = filp->private_data;
1193 struct event_subsystem *system = dir->subsystem;
1194 struct trace_seq *s;
1195 int r;
1196
1197 if (*ppos)
1198 return 0;
1199
1200 s = kmalloc(sizeof(*s), GFP_KERNEL);
1201 if (!s)
1202 return -ENOMEM;
1203
1204 trace_seq_init(s);
1205
1206 print_subsystem_event_filter(system, s);
1207 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1208
1209 kfree(s);
1210
1211 return r;
1212}
1213
1214static ssize_t
1215subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1216 loff_t *ppos)
1217{
1218 struct ftrace_subsystem_dir *dir = filp->private_data;
1219 char *buf;
1220 int err;
1221
1222 if (cnt >= PAGE_SIZE)
1223 return -EINVAL;
1224
1225 buf = (char *)__get_free_page(GFP_TEMPORARY);
1226 if (!buf)
1227 return -ENOMEM;
1228
1229 if (copy_from_user(buf, ubuf, cnt)) {
1230 free_page((unsigned long) buf);
1231 return -EFAULT;
1232 }
1233 buf[cnt] = '\0';
1234
1235 err = apply_subsystem_event_filter(dir, buf);
1236 free_page((unsigned long) buf);
1237 if (err < 0)
1238 return err;
1239
1240 *ppos += cnt;
1241
1242 return cnt;
1243}
1244
1245static ssize_t
1246show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1247{
1248 int (*func)(struct trace_seq *s) = filp->private_data;
1249 struct trace_seq *s;
1250 int r;
1251
1252 if (*ppos)
1253 return 0;
1254
1255 s = kmalloc(sizeof(*s), GFP_KERNEL);
1256 if (!s)
1257 return -ENOMEM;
1258
1259 trace_seq_init(s);
1260
1261 func(s);
1262 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1263
1264 kfree(s);
1265
1266 return r;
1267}
1268
1269static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1270static int ftrace_event_set_open(struct inode *inode, struct file *file);
1271static int ftrace_event_release(struct inode *inode, struct file *file);
1272
1273static const struct seq_operations show_event_seq_ops = {
1274 .start = t_start,
1275 .next = t_next,
1276 .show = t_show,
1277 .stop = t_stop,
1278};
1279
1280static const struct seq_operations show_set_event_seq_ops = {
1281 .start = s_start,
1282 .next = s_next,
1283 .show = t_show,
1284 .stop = t_stop,
1285};
1286
1287static const struct file_operations ftrace_avail_fops = {
1288 .open = ftrace_event_avail_open,
1289 .read = seq_read,
1290 .llseek = seq_lseek,
1291 .release = seq_release,
1292};
1293
1294static const struct file_operations ftrace_set_event_fops = {
1295 .open = ftrace_event_set_open,
1296 .read = seq_read,
1297 .write = ftrace_event_write,
1298 .llseek = seq_lseek,
1299 .release = ftrace_event_release,
1300};
1301
1302static const struct file_operations ftrace_enable_fops = {
1303 .open = tracing_open_generic,
1304 .read = event_enable_read,
1305 .write = event_enable_write,
1306 .llseek = default_llseek,
1307};
1308
1309static const struct file_operations ftrace_event_format_fops = {
1310 .open = trace_format_open,
1311 .read = seq_read,
1312 .llseek = seq_lseek,
1313 .release = seq_release,
1314};
1315
1316static const struct file_operations ftrace_event_id_fops = {
1317 .read = event_id_read,
1318 .llseek = default_llseek,
1319};
1320
1321static const struct file_operations ftrace_event_filter_fops = {
1322 .open = tracing_open_generic,
1323 .read = event_filter_read,
1324 .write = event_filter_write,
1325 .llseek = default_llseek,
1326};
1327
1328static const struct file_operations ftrace_subsystem_filter_fops = {
1329 .open = subsystem_open,
1330 .read = subsystem_filter_read,
1331 .write = subsystem_filter_write,
1332 .llseek = default_llseek,
1333 .release = subsystem_release,
1334};
1335
1336static const struct file_operations ftrace_system_enable_fops = {
1337 .open = subsystem_open,
1338 .read = system_enable_read,
1339 .write = system_enable_write,
1340 .llseek = default_llseek,
1341 .release = subsystem_release,
1342};
1343
1344static const struct file_operations ftrace_tr_enable_fops = {
1345 .open = system_tr_open,
1346 .read = system_enable_read,
1347 .write = system_enable_write,
1348 .llseek = default_llseek,
1349 .release = subsystem_release,
1350};
1351
1352static const struct file_operations ftrace_show_header_fops = {
1353 .open = tracing_open_generic,
1354 .read = show_header,
1355 .llseek = default_llseek,
1356};
1357
1358static int
1359ftrace_event_open(struct inode *inode, struct file *file,
1360 const struct seq_operations *seq_ops)
1361{
1362 struct seq_file *m;
1363 int ret;
1364
1365 ret = seq_open(file, seq_ops);
1366 if (ret < 0)
1367 return ret;
1368 m = file->private_data;
1369 /* copy tr over to seq ops */
1370 m->private = inode->i_private;
1371
1372 return ret;
1373}
1374
1375static int ftrace_event_release(struct inode *inode, struct file *file)
1376{
1377 struct trace_array *tr = inode->i_private;
1378
1379 trace_array_put(tr);
1380
1381 return seq_release(inode, file);
1382}
1383
1384static int
1385ftrace_event_avail_open(struct inode *inode, struct file *file)
1386{
1387 const struct seq_operations *seq_ops = &show_event_seq_ops;
1388
1389 return ftrace_event_open(inode, file, seq_ops);
1390}
1391
1392static int
1393ftrace_event_set_open(struct inode *inode, struct file *file)
1394{
1395 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1396 struct trace_array *tr = inode->i_private;
1397 int ret;
1398
1399 if (trace_array_get(tr) < 0)
1400 return -ENODEV;
1401
1402 if ((file->f_mode & FMODE_WRITE) &&
1403 (file->f_flags & O_TRUNC))
1404 ftrace_clear_events(tr);
1405
1406 ret = ftrace_event_open(inode, file, seq_ops);
1407 if (ret < 0)
1408 trace_array_put(tr);
1409 return ret;
1410}
1411
1412static struct event_subsystem *
1413create_new_subsystem(const char *name)
1414{
1415 struct event_subsystem *system;
1416
1417 /* need to create new entry */
1418 system = kmalloc(sizeof(*system), GFP_KERNEL);
1419 if (!system)
1420 return NULL;
1421
1422 system->ref_count = 1;
1423
1424 /* Only allocate if dynamic (kprobes and modules) */
1425 if (!core_kernel_data((unsigned long)name)) {
1426 system->ref_count |= SYSTEM_FL_FREE_NAME;
1427 system->name = kstrdup(name, GFP_KERNEL);
1428 if (!system->name)
1429 goto out_free;
1430 } else
1431 system->name = name;
1432
1433 system->filter = NULL;
1434
1435 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1436 if (!system->filter)
1437 goto out_free;
1438
1439 list_add(&system->list, &event_subsystems);
1440
1441 return system;
1442
1443 out_free:
1444 if (system->ref_count & SYSTEM_FL_FREE_NAME)
1445 kfree(system->name);
1446 kfree(system);
1447 return NULL;
1448}
1449
1450static struct dentry *
1451event_subsystem_dir(struct trace_array *tr, const char *name,
1452 struct ftrace_event_file *file, struct dentry *parent)
1453{
1454 struct ftrace_subsystem_dir *dir;
1455 struct event_subsystem *system;
1456 struct dentry *entry;
1457
1458 /* First see if we did not already create this dir */
1459 list_for_each_entry(dir, &tr->systems, list) {
1460 system = dir->subsystem;
1461 if (strcmp(system->name, name) == 0) {
1462 dir->nr_events++;
1463 file->system = dir;
1464 return dir->entry;
1465 }
1466 }
1467
1468 /* Now see if the system itself exists. */
1469 list_for_each_entry(system, &event_subsystems, list) {
1470 if (strcmp(system->name, name) == 0)
1471 break;
1472 }
1473 /* Reset system variable when not found */
1474 if (&system->list == &event_subsystems)
1475 system = NULL;
1476
1477 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1478 if (!dir)
1479 goto out_fail;
1480
1481 if (!system) {
1482 system = create_new_subsystem(name);
1483 if (!system)
1484 goto out_free;
1485 } else
1486 __get_system(system);
1487
1488 dir->entry = debugfs_create_dir(name, parent);
1489 if (!dir->entry) {
1490 pr_warning("Failed to create system directory %s\n", name);
1491 __put_system(system);
1492 goto out_free;
1493 }
1494
1495 dir->tr = tr;
1496 dir->ref_count = 1;
1497 dir->nr_events = 1;
1498 dir->subsystem = system;
1499 file->system = dir;
1500
1501 entry = debugfs_create_file("filter", 0644, dir->entry, dir,
1502 &ftrace_subsystem_filter_fops);
1503 if (!entry) {
1504 kfree(system->filter);
1505 system->filter = NULL;
1506 pr_warning("Could not create debugfs '%s/filter' entry\n", name);
1507 }
1508
1509 trace_create_file("enable", 0644, dir->entry, dir,
1510 &ftrace_system_enable_fops);
1511
1512 list_add(&dir->list, &tr->systems);
1513
1514 return dir->entry;
1515
1516 out_free:
1517 kfree(dir);
1518 out_fail:
1519 /* Only print this message if failed on memory allocation */
1520 if (!dir || !system)
1521 pr_warning("No memory to create event subsystem %s\n",
1522 name);
1523 return NULL;
1524}
1525
1526static int
1527event_create_dir(struct dentry *parent, struct ftrace_event_file *file)
1528{
1529 struct ftrace_event_call *call = file->event_call;
1530 struct trace_array *tr = file->tr;
1531 struct list_head *head;
1532 struct dentry *d_events;
1533 const char *name;
1534 int ret;
1535
1536 /*
1537 * If the trace point header did not define TRACE_SYSTEM
1538 * then the system would be called "TRACE_SYSTEM".
1539 */
1540 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1541 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1542 if (!d_events)
1543 return -ENOMEM;
1544 } else
1545 d_events = parent;
1546
1547 name = ftrace_event_name(call);
1548 file->dir = debugfs_create_dir(name, d_events);
1549 if (!file->dir) {
1550 pr_warning("Could not create debugfs '%s' directory\n",
1551 name);
1552 return -1;
1553 }
1554
1555 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1556 trace_create_file("enable", 0644, file->dir, file,
1557 &ftrace_enable_fops);
1558
1559#ifdef CONFIG_PERF_EVENTS
1560 if (call->event.type && call->class->reg)
1561 trace_create_file("id", 0444, file->dir,
1562 (void *)(long)call->event.type,
1563 &ftrace_event_id_fops);
1564#endif
1565
1566 /*
1567 * Other events may have the same class. Only update
1568 * the fields if they are not already defined.
1569 */
1570 head = trace_get_fields(call);
1571 if (list_empty(head)) {
1572 ret = call->class->define_fields(call);
1573 if (ret < 0) {
1574 pr_warning("Could not initialize trace point"
1575 " events/%s\n", name);
1576 return -1;
1577 }
1578 }
1579 trace_create_file("filter", 0644, file->dir, file,
1580 &ftrace_event_filter_fops);
1581
1582 trace_create_file("trigger", 0644, file->dir, file,
1583 &event_trigger_fops);
1584
1585 trace_create_file("format", 0444, file->dir, call,
1586 &ftrace_event_format_fops);
1587
1588 return 0;
1589}
1590
1591static void remove_event_from_tracers(struct ftrace_event_call *call)
1592{
1593 struct ftrace_event_file *file;
1594 struct trace_array *tr;
1595
1596 do_for_each_event_file_safe(tr, file) {
1597 if (file->event_call != call)
1598 continue;
1599
1600 remove_event_file_dir(file);
1601 /*
1602 * The do_for_each_event_file_safe() is
1603 * a double loop. After finding the call for this
1604 * trace_array, we use break to jump to the next
1605 * trace_array.
1606 */
1607 break;
1608 } while_for_each_event_file();
1609}
1610
1611static void event_remove(struct ftrace_event_call *call)
1612{
1613 struct trace_array *tr;
1614 struct ftrace_event_file *file;
1615
1616 do_for_each_event_file(tr, file) {
1617 if (file->event_call != call)
1618 continue;
1619 ftrace_event_enable_disable(file, 0);
1620 destroy_preds(file);
1621 /*
1622 * The do_for_each_event_file() is
1623 * a double loop. After finding the call for this
1624 * trace_array, we use break to jump to the next
1625 * trace_array.
1626 */
1627 break;
1628 } while_for_each_event_file();
1629
1630 if (call->event.funcs)
1631 __unregister_ftrace_event(&call->event);
1632 remove_event_from_tracers(call);
1633 list_del(&call->list);
1634}
1635
1636static int event_init(struct ftrace_event_call *call)
1637{
1638 int ret = 0;
1639 const char *name;
1640
1641 name = ftrace_event_name(call);
1642 if (WARN_ON(!name))
1643 return -EINVAL;
1644
1645 if (call->class->raw_init) {
1646 ret = call->class->raw_init(call);
1647 if (ret < 0 && ret != -ENOSYS)
1648 pr_warn("Could not initialize trace events/%s\n",
1649 name);
1650 }
1651
1652 return ret;
1653}
1654
1655static int
1656__register_event(struct ftrace_event_call *call, struct module *mod)
1657{
1658 int ret;
1659
1660 ret = event_init(call);
1661 if (ret < 0)
1662 return ret;
1663
1664 list_add(&call->list, &ftrace_events);
1665 call->mod = mod;
1666
1667 return 0;
1668}
1669
1670static struct ftrace_event_file *
1671trace_create_new_event(struct ftrace_event_call *call,
1672 struct trace_array *tr)
1673{
1674 struct ftrace_event_file *file;
1675
1676 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
1677 if (!file)
1678 return NULL;
1679
1680 file->event_call = call;
1681 file->tr = tr;
1682 atomic_set(&file->sm_ref, 0);
1683 atomic_set(&file->tm_ref, 0);
1684 INIT_LIST_HEAD(&file->triggers);
1685 list_add(&file->list, &tr->events);
1686
1687 return file;
1688}
1689
1690/* Add an event to a trace directory */
1691static int
1692__trace_add_new_event(struct ftrace_event_call *call, struct trace_array *tr)
1693{
1694 struct ftrace_event_file *file;
1695
1696 file = trace_create_new_event(call, tr);
1697 if (!file)
1698 return -ENOMEM;
1699
1700 return event_create_dir(tr->event_dir, file);
1701}
1702
1703/*
1704 * Just create a decriptor for early init. A descriptor is required
1705 * for enabling events at boot. We want to enable events before
1706 * the filesystem is initialized.
1707 */
1708static __init int
1709__trace_early_add_new_event(struct ftrace_event_call *call,
1710 struct trace_array *tr)
1711{
1712 struct ftrace_event_file *file;
1713
1714 file = trace_create_new_event(call, tr);
1715 if (!file)
1716 return -ENOMEM;
1717
1718 return 0;
1719}
1720
1721struct ftrace_module_file_ops;
1722static void __add_event_to_tracers(struct ftrace_event_call *call);
1723
1724/* Add an additional event_call dynamically */
1725int trace_add_event_call(struct ftrace_event_call *call)
1726{
1727 int ret;
1728 mutex_lock(&trace_types_lock);
1729 mutex_lock(&event_mutex);
1730
1731 ret = __register_event(call, NULL);
1732 if (ret >= 0)
1733 __add_event_to_tracers(call);
1734
1735 mutex_unlock(&event_mutex);
1736 mutex_unlock(&trace_types_lock);
1737 return ret;
1738}
1739
1740/*
1741 * Must be called under locking of trace_types_lock, event_mutex and
1742 * trace_event_sem.
1743 */
1744static void __trace_remove_event_call(struct ftrace_event_call *call)
1745{
1746 event_remove(call);
1747 trace_destroy_fields(call);
1748 destroy_call_preds(call);
1749}
1750
1751static int probe_remove_event_call(struct ftrace_event_call *call)
1752{
1753 struct trace_array *tr;
1754 struct ftrace_event_file *file;
1755
1756#ifdef CONFIG_PERF_EVENTS
1757 if (call->perf_refcount)
1758 return -EBUSY;
1759#endif
1760 do_for_each_event_file(tr, file) {
1761 if (file->event_call != call)
1762 continue;
1763 /*
1764 * We can't rely on ftrace_event_enable_disable(enable => 0)
1765 * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
1766 * TRACE_REG_UNREGISTER.
1767 */
1768 if (file->flags & FTRACE_EVENT_FL_ENABLED)
1769 return -EBUSY;
1770 /*
1771 * The do_for_each_event_file_safe() is
1772 * a double loop. After finding the call for this
1773 * trace_array, we use break to jump to the next
1774 * trace_array.
1775 */
1776 break;
1777 } while_for_each_event_file();
1778
1779 __trace_remove_event_call(call);
1780
1781 return 0;
1782}
1783
1784/* Remove an event_call */
1785int trace_remove_event_call(struct ftrace_event_call *call)
1786{
1787 int ret;
1788
1789 mutex_lock(&trace_types_lock);
1790 mutex_lock(&event_mutex);
1791 down_write(&trace_event_sem);
1792 ret = probe_remove_event_call(call);
1793 up_write(&trace_event_sem);
1794 mutex_unlock(&event_mutex);
1795 mutex_unlock(&trace_types_lock);
1796
1797 return ret;
1798}
1799
1800#define for_each_event(event, start, end) \
1801 for (event = start; \
1802 (unsigned long)event < (unsigned long)end; \
1803 event++)
1804
1805#ifdef CONFIG_MODULES
1806
1807static void trace_module_add_events(struct module *mod)
1808{
1809 struct ftrace_event_call **call, **start, **end;
1810
1811 if (!mod->num_trace_events)
1812 return;
1813
1814 /* Don't add infrastructure for mods without tracepoints */
1815 if (trace_module_has_bad_taint(mod)) {
1816 pr_err("%s: module has bad taint, not creating trace events\n",
1817 mod->name);
1818 return;
1819 }
1820
1821 start = mod->trace_events;
1822 end = mod->trace_events + mod->num_trace_events;
1823
1824 for_each_event(call, start, end) {
1825 __register_event(*call, mod);
1826 __add_event_to_tracers(*call);
1827 }
1828}
1829
1830static void trace_module_remove_events(struct module *mod)
1831{
1832 struct ftrace_event_call *call, *p;
1833 bool clear_trace = false;
1834
1835 down_write(&trace_event_sem);
1836 list_for_each_entry_safe(call, p, &ftrace_events, list) {
1837 if (call->mod == mod) {
1838 if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
1839 clear_trace = true;
1840 __trace_remove_event_call(call);
1841 }
1842 }
1843 up_write(&trace_event_sem);
1844
1845 /*
1846 * It is safest to reset the ring buffer if the module being unloaded
1847 * registered any events that were used. The only worry is if
1848 * a new module gets loaded, and takes on the same id as the events
1849 * of this module. When printing out the buffer, traced events left
1850 * over from this module may be passed to the new module events and
1851 * unexpected results may occur.
1852 */
1853 if (clear_trace)
1854 tracing_reset_all_online_cpus();
1855}
1856
1857static int trace_module_notify(struct notifier_block *self,
1858 unsigned long val, void *data)
1859{
1860 struct module *mod = data;
1861
1862 mutex_lock(&trace_types_lock);
1863 mutex_lock(&event_mutex);
1864 switch (val) {
1865 case MODULE_STATE_COMING:
1866 trace_module_add_events(mod);
1867 break;
1868 case MODULE_STATE_GOING:
1869 trace_module_remove_events(mod);
1870 break;
1871 }
1872 mutex_unlock(&event_mutex);
1873 mutex_unlock(&trace_types_lock);
1874
1875 return 0;
1876}
1877
1878static struct notifier_block trace_module_nb = {
1879 .notifier_call = trace_module_notify,
1880 .priority = 0,
1881};
1882#endif /* CONFIG_MODULES */
1883
1884/* Create a new event directory structure for a trace directory. */
1885static void
1886__trace_add_event_dirs(struct trace_array *tr)
1887{
1888 struct ftrace_event_call *call;
1889 int ret;
1890
1891 list_for_each_entry(call, &ftrace_events, list) {
1892 ret = __trace_add_new_event(call, tr);
1893 if (ret < 0)
1894 pr_warning("Could not create directory for event %s\n",
1895 ftrace_event_name(call));
1896 }
1897}
1898
1899struct ftrace_event_file *
1900find_event_file(struct trace_array *tr, const char *system, const char *event)
1901{
1902 struct ftrace_event_file *file;
1903 struct ftrace_event_call *call;
1904 const char *name;
1905
1906 list_for_each_entry(file, &tr->events, list) {
1907
1908 call = file->event_call;
1909 name = ftrace_event_name(call);
1910
1911 if (!name || !call->class || !call->class->reg)
1912 continue;
1913
1914 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1915 continue;
1916
1917 if (strcmp(event, name) == 0 &&
1918 strcmp(system, call->class->system) == 0)
1919 return file;
1920 }
1921 return NULL;
1922}
1923
1924#ifdef CONFIG_DYNAMIC_FTRACE
1925
1926/* Avoid typos */
1927#define ENABLE_EVENT_STR "enable_event"
1928#define DISABLE_EVENT_STR "disable_event"
1929
1930struct event_probe_data {
1931 struct ftrace_event_file *file;
1932 unsigned long count;
1933 int ref;
1934 bool enable;
1935};
1936
1937static void
1938event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1939{
1940 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1941 struct event_probe_data *data = *pdata;
1942
1943 if (!data)
1944 return;
1945
1946 if (data->enable)
1947 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1948 else
1949 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1950}
1951
1952static void
1953event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1954{
1955 struct event_probe_data **pdata = (struct event_probe_data **)_data;
1956 struct event_probe_data *data = *pdata;
1957
1958 if (!data)
1959 return;
1960
1961 if (!data->count)
1962 return;
1963
1964 /* Skip if the event is in a state we want to switch to */
1965 if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
1966 return;
1967
1968 if (data->count != -1)
1969 (data->count)--;
1970
1971 event_enable_probe(ip, parent_ip, _data);
1972}
1973
1974static int
1975event_enable_print(struct seq_file *m, unsigned long ip,
1976 struct ftrace_probe_ops *ops, void *_data)
1977{
1978 struct event_probe_data *data = _data;
1979
1980 seq_printf(m, "%ps:", (void *)ip);
1981
1982 seq_printf(m, "%s:%s:%s",
1983 data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
1984 data->file->event_call->class->system,
1985 ftrace_event_name(data->file->event_call));
1986
1987 if (data->count == -1)
1988 seq_printf(m, ":unlimited\n");
1989 else
1990 seq_printf(m, ":count=%ld\n", data->count);
1991
1992 return 0;
1993}
1994
1995static int
1996event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
1997 void **_data)
1998{
1999 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2000 struct event_probe_data *data = *pdata;
2001
2002 data->ref++;
2003 return 0;
2004}
2005
2006static void
2007event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
2008 void **_data)
2009{
2010 struct event_probe_data **pdata = (struct event_probe_data **)_data;
2011 struct event_probe_data *data = *pdata;
2012
2013 if (WARN_ON_ONCE(data->ref <= 0))
2014 return;
2015
2016 data->ref--;
2017 if (!data->ref) {
2018 /* Remove the SOFT_MODE flag */
2019 __ftrace_event_enable_disable(data->file, 0, 1);
2020 module_put(data->file->event_call->mod);
2021 kfree(data);
2022 }
2023 *pdata = NULL;
2024}
2025
2026static struct ftrace_probe_ops event_enable_probe_ops = {
2027 .func = event_enable_probe,
2028 .print = event_enable_print,
2029 .init = event_enable_init,
2030 .free = event_enable_free,
2031};
2032
2033static struct ftrace_probe_ops event_enable_count_probe_ops = {
2034 .func = event_enable_count_probe,
2035 .print = event_enable_print,
2036 .init = event_enable_init,
2037 .free = event_enable_free,
2038};
2039
2040static struct ftrace_probe_ops event_disable_probe_ops = {
2041 .func = event_enable_probe,
2042 .print = event_enable_print,
2043 .init = event_enable_init,
2044 .free = event_enable_free,
2045};
2046
2047static struct ftrace_probe_ops event_disable_count_probe_ops = {
2048 .func = event_enable_count_probe,
2049 .print = event_enable_print,
2050 .init = event_enable_init,
2051 .free = event_enable_free,
2052};
2053
2054static int
2055event_enable_func(struct ftrace_hash *hash,
2056 char *glob, char *cmd, char *param, int enabled)
2057{
2058 struct trace_array *tr = top_trace_array();
2059 struct ftrace_event_file *file;
2060 struct ftrace_probe_ops *ops;
2061 struct event_probe_data *data;
2062 const char *system;
2063 const char *event;
2064 char *number;
2065 bool enable;
2066 int ret;
2067
2068 /* hash funcs only work with set_ftrace_filter */
2069 if (!enabled || !param)
2070 return -EINVAL;
2071
2072 system = strsep(¶m, ":");
2073 if (!param)
2074 return -EINVAL;
2075
2076 event = strsep(¶m, ":");
2077
2078 mutex_lock(&event_mutex);
2079
2080 ret = -EINVAL;
2081 file = find_event_file(tr, system, event);
2082 if (!file)
2083 goto out;
2084
2085 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2086
2087 if (enable)
2088 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2089 else
2090 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2091
2092 if (glob[0] == '!') {
2093 unregister_ftrace_function_probe_func(glob+1, ops);
2094 ret = 0;
2095 goto out;
2096 }
2097
2098 ret = -ENOMEM;
2099 data = kzalloc(sizeof(*data), GFP_KERNEL);
2100 if (!data)
2101 goto out;
2102
2103 data->enable = enable;
2104 data->count = -1;
2105 data->file = file;
2106
2107 if (!param)
2108 goto out_reg;
2109
2110 number = strsep(¶m, ":");
2111
2112 ret = -EINVAL;
2113 if (!strlen(number))
2114 goto out_free;
2115
2116 /*
2117 * We use the callback data field (which is a pointer)
2118 * as our counter.
2119 */
2120 ret = kstrtoul(number, 0, &data->count);
2121 if (ret)
2122 goto out_free;
2123
2124 out_reg:
2125 /* Don't let event modules unload while probe registered */
2126 ret = try_module_get(file->event_call->mod);
2127 if (!ret) {
2128 ret = -EBUSY;
2129 goto out_free;
2130 }
2131
2132 ret = __ftrace_event_enable_disable(file, 1, 1);
2133 if (ret < 0)
2134 goto out_put;
2135 ret = register_ftrace_function_probe(glob, ops, data);
2136 /*
2137 * The above returns on success the # of functions enabled,
2138 * but if it didn't find any functions it returns zero.
2139 * Consider no functions a failure too.
2140 */
2141 if (!ret) {
2142 ret = -ENOENT;
2143 goto out_disable;
2144 } else if (ret < 0)
2145 goto out_disable;
2146 /* Just return zero, not the number of enabled functions */
2147 ret = 0;
2148 out:
2149 mutex_unlock(&event_mutex);
2150 return ret;
2151
2152 out_disable:
2153 __ftrace_event_enable_disable(file, 0, 1);
2154 out_put:
2155 module_put(file->event_call->mod);
2156 out_free:
2157 kfree(data);
2158 goto out;
2159}
2160
2161static struct ftrace_func_command event_enable_cmd = {
2162 .name = ENABLE_EVENT_STR,
2163 .func = event_enable_func,
2164};
2165
2166static struct ftrace_func_command event_disable_cmd = {
2167 .name = DISABLE_EVENT_STR,
2168 .func = event_enable_func,
2169};
2170
2171static __init int register_event_cmds(void)
2172{
2173 int ret;
2174
2175 ret = register_ftrace_command(&event_enable_cmd);
2176 if (WARN_ON(ret < 0))
2177 return ret;
2178 ret = register_ftrace_command(&event_disable_cmd);
2179 if (WARN_ON(ret < 0))
2180 unregister_ftrace_command(&event_enable_cmd);
2181 return ret;
2182}
2183#else
2184static inline int register_event_cmds(void) { return 0; }
2185#endif /* CONFIG_DYNAMIC_FTRACE */
2186
2187/*
2188 * The top level array has already had its ftrace_event_file
2189 * descriptors created in order to allow for early events to
2190 * be recorded. This function is called after the debugfs has been
2191 * initialized, and we now have to create the files associated
2192 * to the events.
2193 */
2194static __init void
2195__trace_early_add_event_dirs(struct trace_array *tr)
2196{
2197 struct ftrace_event_file *file;
2198 int ret;
2199
2200
2201 list_for_each_entry(file, &tr->events, list) {
2202 ret = event_create_dir(tr->event_dir, file);
2203 if (ret < 0)
2204 pr_warning("Could not create directory for event %s\n",
2205 ftrace_event_name(file->event_call));
2206 }
2207}
2208
2209/*
2210 * For early boot up, the top trace array requires to have
2211 * a list of events that can be enabled. This must be done before
2212 * the filesystem is set up in order to allow events to be traced
2213 * early.
2214 */
2215static __init void
2216__trace_early_add_events(struct trace_array *tr)
2217{
2218 struct ftrace_event_call *call;
2219 int ret;
2220
2221 list_for_each_entry(call, &ftrace_events, list) {
2222 /* Early boot up should not have any modules loaded */
2223 if (WARN_ON_ONCE(call->mod))
2224 continue;
2225
2226 ret = __trace_early_add_new_event(call, tr);
2227 if (ret < 0)
2228 pr_warning("Could not create early event %s\n",
2229 ftrace_event_name(call));
2230 }
2231}
2232
2233/* Remove the event directory structure for a trace directory. */
2234static void
2235__trace_remove_event_dirs(struct trace_array *tr)
2236{
2237 struct ftrace_event_file *file, *next;
2238
2239 list_for_each_entry_safe(file, next, &tr->events, list)
2240 remove_event_file_dir(file);
2241}
2242
2243static void __add_event_to_tracers(struct ftrace_event_call *call)
2244{
2245 struct trace_array *tr;
2246
2247 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2248 __trace_add_new_event(call, tr);
2249}
2250
2251extern struct ftrace_event_call *__start_ftrace_events[];
2252extern struct ftrace_event_call *__stop_ftrace_events[];
2253
2254static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2255
2256static __init int setup_trace_event(char *str)
2257{
2258 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2259 ring_buffer_expanded = true;
2260 tracing_selftest_disabled = true;
2261
2262 return 1;
2263}
2264__setup("trace_event=", setup_trace_event);
2265
2266/* Expects to have event_mutex held when called */
2267static int
2268create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2269{
2270 struct dentry *d_events;
2271 struct dentry *entry;
2272
2273 entry = debugfs_create_file("set_event", 0644, parent,
2274 tr, &ftrace_set_event_fops);
2275 if (!entry) {
2276 pr_warning("Could not create debugfs 'set_event' entry\n");
2277 return -ENOMEM;
2278 }
2279
2280 d_events = debugfs_create_dir("events", parent);
2281 if (!d_events) {
2282 pr_warning("Could not create debugfs 'events' directory\n");
2283 return -ENOMEM;
2284 }
2285
2286 /* ring buffer internal formats */
2287 trace_create_file("header_page", 0444, d_events,
2288 ring_buffer_print_page_header,
2289 &ftrace_show_header_fops);
2290
2291 trace_create_file("header_event", 0444, d_events,
2292 ring_buffer_print_entry_header,
2293 &ftrace_show_header_fops);
2294
2295 trace_create_file("enable", 0644, d_events,
2296 tr, &ftrace_tr_enable_fops);
2297
2298 tr->event_dir = d_events;
2299
2300 return 0;
2301}
2302
2303/**
2304 * event_trace_add_tracer - add a instance of a trace_array to events
2305 * @parent: The parent dentry to place the files/directories for events in
2306 * @tr: The trace array associated with these events
2307 *
2308 * When a new instance is created, it needs to set up its events
2309 * directory, as well as other files associated with events. It also
2310 * creates the event hierachry in the @parent/events directory.
2311 *
2312 * Returns 0 on success.
2313 */
2314int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2315{
2316 int ret;
2317
2318 mutex_lock(&event_mutex);
2319
2320 ret = create_event_toplevel_files(parent, tr);
2321 if (ret)
2322 goto out_unlock;
2323
2324 down_write(&trace_event_sem);
2325 __trace_add_event_dirs(tr);
2326 up_write(&trace_event_sem);
2327
2328 out_unlock:
2329 mutex_unlock(&event_mutex);
2330
2331 return ret;
2332}
2333
2334/*
2335 * The top trace array already had its file descriptors created.
2336 * Now the files themselves need to be created.
2337 */
2338static __init int
2339early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2340{
2341 int ret;
2342
2343 mutex_lock(&event_mutex);
2344
2345 ret = create_event_toplevel_files(parent, tr);
2346 if (ret)
2347 goto out_unlock;
2348
2349 down_write(&trace_event_sem);
2350 __trace_early_add_event_dirs(tr);
2351 up_write(&trace_event_sem);
2352
2353 out_unlock:
2354 mutex_unlock(&event_mutex);
2355
2356 return ret;
2357}
2358
2359int event_trace_del_tracer(struct trace_array *tr)
2360{
2361 mutex_lock(&event_mutex);
2362
2363 /* Disable any event triggers and associated soft-disabled events */
2364 clear_event_triggers(tr);
2365
2366 /* Disable any running events */
2367 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
2368
2369 /* Access to events are within rcu_read_lock_sched() */
2370 synchronize_sched();
2371
2372 down_write(&trace_event_sem);
2373 __trace_remove_event_dirs(tr);
2374 debugfs_remove_recursive(tr->event_dir);
2375 up_write(&trace_event_sem);
2376
2377 tr->event_dir = NULL;
2378
2379 mutex_unlock(&event_mutex);
2380
2381 return 0;
2382}
2383
2384static __init int event_trace_memsetup(void)
2385{
2386 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
2387 file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC);
2388 return 0;
2389}
2390
2391static __init int event_trace_enable(void)
2392{
2393 struct trace_array *tr = top_trace_array();
2394 struct ftrace_event_call **iter, *call;
2395 char *buf = bootup_event_buf;
2396 char *token;
2397 int ret;
2398
2399 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
2400
2401 call = *iter;
2402 ret = event_init(call);
2403 if (!ret)
2404 list_add(&call->list, &ftrace_events);
2405 }
2406
2407 /*
2408 * We need the top trace array to have a working set of trace
2409 * points at early init, before the debug files and directories
2410 * are created. Create the file entries now, and attach them
2411 * to the actual file dentries later.
2412 */
2413 __trace_early_add_events(tr);
2414
2415 while (true) {
2416 token = strsep(&buf, ",");
2417
2418 if (!token)
2419 break;
2420 if (!*token)
2421 continue;
2422
2423 ret = ftrace_set_clr_event(tr, token, 1);
2424 if (ret)
2425 pr_warn("Failed to enable trace event: %s\n", token);
2426 }
2427
2428 trace_printk_start_comm();
2429
2430 register_event_cmds();
2431
2432 register_trigger_cmds();
2433
2434 return 0;
2435}
2436
2437static __init int event_trace_init(void)
2438{
2439 struct trace_array *tr;
2440 struct dentry *d_tracer;
2441 struct dentry *entry;
2442 int ret;
2443
2444 tr = top_trace_array();
2445
2446 d_tracer = tracing_init_dentry();
2447 if (!d_tracer)
2448 return 0;
2449
2450 entry = debugfs_create_file("available_events", 0444, d_tracer,
2451 tr, &ftrace_avail_fops);
2452 if (!entry)
2453 pr_warning("Could not create debugfs "
2454 "'available_events' entry\n");
2455
2456 if (trace_define_common_fields())
2457 pr_warning("tracing: Failed to allocate common fields");
2458
2459 ret = early_event_add_tracer(d_tracer, tr);
2460 if (ret)
2461 return ret;
2462
2463#ifdef CONFIG_MODULES
2464 ret = register_module_notifier(&trace_module_nb);
2465 if (ret)
2466 pr_warning("Failed to register trace events module notifier\n");
2467#endif
2468 return 0;
2469}
2470early_initcall(event_trace_memsetup);
2471core_initcall(event_trace_enable);
2472fs_initcall(event_trace_init);
2473
2474#ifdef CONFIG_FTRACE_STARTUP_TEST
2475
2476static DEFINE_SPINLOCK(test_spinlock);
2477static DEFINE_SPINLOCK(test_spinlock_irq);
2478static DEFINE_MUTEX(test_mutex);
2479
2480static __init void test_work(struct work_struct *dummy)
2481{
2482 spin_lock(&test_spinlock);
2483 spin_lock_irq(&test_spinlock_irq);
2484 udelay(1);
2485 spin_unlock_irq(&test_spinlock_irq);
2486 spin_unlock(&test_spinlock);
2487
2488 mutex_lock(&test_mutex);
2489 msleep(1);
2490 mutex_unlock(&test_mutex);
2491}
2492
2493static __init int event_test_thread(void *unused)
2494{
2495 void *test_malloc;
2496
2497 test_malloc = kmalloc(1234, GFP_KERNEL);
2498 if (!test_malloc)
2499 pr_info("failed to kmalloc\n");
2500
2501 schedule_on_each_cpu(test_work);
2502
2503 kfree(test_malloc);
2504
2505 set_current_state(TASK_INTERRUPTIBLE);
2506 while (!kthread_should_stop())
2507 schedule();
2508
2509 return 0;
2510}
2511
2512/*
2513 * Do various things that may trigger events.
2514 */
2515static __init void event_test_stuff(void)
2516{
2517 struct task_struct *test_thread;
2518
2519 test_thread = kthread_run(event_test_thread, NULL, "test-events");
2520 msleep(1);
2521 kthread_stop(test_thread);
2522}
2523
2524/*
2525 * For every trace event defined, we will test each trace point separately,
2526 * and then by groups, and finally all trace points.
2527 */
2528static __init void event_trace_self_tests(void)
2529{
2530 struct ftrace_subsystem_dir *dir;
2531 struct ftrace_event_file *file;
2532 struct ftrace_event_call *call;
2533 struct event_subsystem *system;
2534 struct trace_array *tr;
2535 int ret;
2536
2537 tr = top_trace_array();
2538
2539 pr_info("Running tests on trace events:\n");
2540
2541 list_for_each_entry(file, &tr->events, list) {
2542
2543 call = file->event_call;
2544
2545 /* Only test those that have a probe */
2546 if (!call->class || !call->class->probe)
2547 continue;
2548
2549/*
2550 * Testing syscall events here is pretty useless, but
2551 * we still do it if configured. But this is time consuming.
2552 * What we really need is a user thread to perform the
2553 * syscalls as we test.
2554 */
2555#ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
2556 if (call->class->system &&
2557 strcmp(call->class->system, "syscalls") == 0)
2558 continue;
2559#endif
2560
2561 pr_info("Testing event %s: ", ftrace_event_name(call));
2562
2563 /*
2564 * If an event is already enabled, someone is using
2565 * it and the self test should not be on.
2566 */
2567 if (file->flags & FTRACE_EVENT_FL_ENABLED) {
2568 pr_warning("Enabled event during self test!\n");
2569 WARN_ON_ONCE(1);
2570 continue;
2571 }
2572
2573 ftrace_event_enable_disable(file, 1);
2574 event_test_stuff();
2575 ftrace_event_enable_disable(file, 0);
2576
2577 pr_cont("OK\n");
2578 }
2579
2580 /* Now test at the sub system level */
2581
2582 pr_info("Running tests on trace event systems:\n");
2583
2584 list_for_each_entry(dir, &tr->systems, list) {
2585
2586 system = dir->subsystem;
2587
2588 /* the ftrace system is special, skip it */
2589 if (strcmp(system->name, "ftrace") == 0)
2590 continue;
2591
2592 pr_info("Testing event system %s: ", system->name);
2593
2594 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
2595 if (WARN_ON_ONCE(ret)) {
2596 pr_warning("error enabling system %s\n",
2597 system->name);
2598 continue;
2599 }
2600
2601 event_test_stuff();
2602
2603 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
2604 if (WARN_ON_ONCE(ret)) {
2605 pr_warning("error disabling system %s\n",
2606 system->name);
2607 continue;
2608 }
2609
2610 pr_cont("OK\n");
2611 }
2612
2613 /* Test with all events enabled */
2614
2615 pr_info("Running tests on all trace events:\n");
2616 pr_info("Testing all events: ");
2617
2618 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
2619 if (WARN_ON_ONCE(ret)) {
2620 pr_warning("error enabling all events\n");
2621 return;
2622 }
2623
2624 event_test_stuff();
2625
2626 /* reset sysname */
2627 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
2628 if (WARN_ON_ONCE(ret)) {
2629 pr_warning("error disabling all events\n");
2630 return;
2631 }
2632
2633 pr_cont("OK\n");
2634}
2635
2636#ifdef CONFIG_FUNCTION_TRACER
2637
2638static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
2639
2640static void
2641function_test_events_call(unsigned long ip, unsigned long parent_ip,
2642 struct ftrace_ops *op, struct pt_regs *pt_regs)
2643{
2644 struct ring_buffer_event *event;
2645 struct ring_buffer *buffer;
2646 struct ftrace_entry *entry;
2647 unsigned long flags;
2648 long disabled;
2649 int cpu;
2650 int pc;
2651
2652 pc = preempt_count();
2653 preempt_disable_notrace();
2654 cpu = raw_smp_processor_id();
2655 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
2656
2657 if (disabled != 1)
2658 goto out;
2659
2660 local_save_flags(flags);
2661
2662 event = trace_current_buffer_lock_reserve(&buffer,
2663 TRACE_FN, sizeof(*entry),
2664 flags, pc);
2665 if (!event)
2666 goto out;
2667 entry = ring_buffer_event_data(event);
2668 entry->ip = ip;
2669 entry->parent_ip = parent_ip;
2670
2671 trace_buffer_unlock_commit(buffer, event, flags, pc);
2672
2673 out:
2674 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
2675 preempt_enable_notrace();
2676}
2677
2678static struct ftrace_ops trace_ops __initdata =
2679{
2680 .func = function_test_events_call,
2681 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
2682};
2683
2684static __init void event_trace_self_test_with_function(void)
2685{
2686 int ret;
2687 ret = register_ftrace_function(&trace_ops);
2688 if (WARN_ON(ret < 0)) {
2689 pr_info("Failed to enable function tracer for event tests\n");
2690 return;
2691 }
2692 pr_info("Running tests again, along with the function tracer\n");
2693 event_trace_self_tests();
2694 unregister_ftrace_function(&trace_ops);
2695}
2696#else
2697static __init void event_trace_self_test_with_function(void)
2698{
2699}
2700#endif
2701
2702static __init int event_trace_self_tests_init(void)
2703{
2704 if (!tracing_selftest_disabled) {
2705 event_trace_self_tests();
2706 event_trace_self_test_with_function();
2707 }
2708
2709 return 0;
2710}
2711
2712late_initcall(event_trace_self_tests_init);
2713
2714#endif