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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
43static LIST_HEAD(module_strings);
44
45struct module_string {
46 struct list_head next;
47 struct module *module;
48 char *str;
49};
50
51#define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
52
53static struct kmem_cache *field_cachep;
54static struct kmem_cache *file_cachep;
55
56static inline int system_refcount(struct event_subsystem *system)
57{
58 return system->ref_count;
59}
60
61static int system_refcount_inc(struct event_subsystem *system)
62{
63 return system->ref_count++;
64}
65
66static int system_refcount_dec(struct event_subsystem *system)
67{
68 return --system->ref_count;
69}
70
71/* Double loops, do not use break, only goto's work */
72#define do_for_each_event_file(tr, file) \
73 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
74 list_for_each_entry(file, &tr->events, list)
75
76#define do_for_each_event_file_safe(tr, file) \
77 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
78 struct trace_event_file *___n; \
79 list_for_each_entry_safe(file, ___n, &tr->events, list)
80
81#define while_for_each_event_file() \
82 }
83
84static struct ftrace_event_field *
85__find_event_field(struct list_head *head, char *name)
86{
87 struct ftrace_event_field *field;
88
89 list_for_each_entry(field, head, link) {
90 if (!strcmp(field->name, name))
91 return field;
92 }
93
94 return NULL;
95}
96
97struct ftrace_event_field *
98trace_find_event_field(struct trace_event_call *call, char *name)
99{
100 struct ftrace_event_field *field;
101 struct list_head *head;
102
103 head = trace_get_fields(call);
104 field = __find_event_field(head, name);
105 if (field)
106 return field;
107
108 field = __find_event_field(&ftrace_generic_fields, name);
109 if (field)
110 return field;
111
112 return __find_event_field(&ftrace_common_fields, name);
113}
114
115static int __trace_define_field(struct list_head *head, const char *type,
116 const char *name, int offset, int size,
117 int is_signed, int filter_type, int len)
118{
119 struct ftrace_event_field *field;
120
121 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
122 if (!field)
123 return -ENOMEM;
124
125 field->name = name;
126 field->type = type;
127
128 if (filter_type == FILTER_OTHER)
129 field->filter_type = filter_assign_type(type);
130 else
131 field->filter_type = filter_type;
132
133 field->offset = offset;
134 field->size = size;
135 field->is_signed = is_signed;
136 field->len = len;
137
138 list_add(&field->link, head);
139
140 return 0;
141}
142
143int trace_define_field(struct trace_event_call *call, const char *type,
144 const char *name, int offset, int size, int is_signed,
145 int filter_type)
146{
147 struct list_head *head;
148
149 if (WARN_ON(!call->class))
150 return 0;
151
152 head = trace_get_fields(call);
153 return __trace_define_field(head, type, name, offset, size,
154 is_signed, filter_type, 0);
155}
156EXPORT_SYMBOL_GPL(trace_define_field);
157
158static int trace_define_field_ext(struct trace_event_call *call, const char *type,
159 const char *name, int offset, int size, int is_signed,
160 int filter_type, int len)
161{
162 struct list_head *head;
163
164 if (WARN_ON(!call->class))
165 return 0;
166
167 head = trace_get_fields(call);
168 return __trace_define_field(head, type, name, offset, size,
169 is_signed, filter_type, len);
170}
171
172#define __generic_field(type, item, filter_type) \
173 ret = __trace_define_field(&ftrace_generic_fields, #type, \
174 #item, 0, 0, is_signed_type(type), \
175 filter_type, 0); \
176 if (ret) \
177 return ret;
178
179#define __common_field(type, item) \
180 ret = __trace_define_field(&ftrace_common_fields, #type, \
181 "common_" #item, \
182 offsetof(typeof(ent), item), \
183 sizeof(ent.item), \
184 is_signed_type(type), FILTER_OTHER, 0); \
185 if (ret) \
186 return ret;
187
188static int trace_define_generic_fields(void)
189{
190 int ret;
191
192 __generic_field(int, CPU, FILTER_CPU);
193 __generic_field(int, cpu, FILTER_CPU);
194 __generic_field(int, common_cpu, FILTER_CPU);
195 __generic_field(char *, COMM, FILTER_COMM);
196 __generic_field(char *, comm, FILTER_COMM);
197 __generic_field(char *, stacktrace, FILTER_STACKTRACE);
198 __generic_field(char *, STACKTRACE, FILTER_STACKTRACE);
199
200 return ret;
201}
202
203static int trace_define_common_fields(void)
204{
205 int ret;
206 struct trace_entry ent;
207
208 __common_field(unsigned short, type);
209 __common_field(unsigned char, flags);
210 /* Holds both preempt_count and migrate_disable */
211 __common_field(unsigned char, preempt_count);
212 __common_field(int, pid);
213
214 return ret;
215}
216
217static void trace_destroy_fields(struct trace_event_call *call)
218{
219 struct ftrace_event_field *field, *next;
220 struct list_head *head;
221
222 head = trace_get_fields(call);
223 list_for_each_entry_safe(field, next, head, link) {
224 list_del(&field->link);
225 kmem_cache_free(field_cachep, field);
226 }
227}
228
229/*
230 * run-time version of trace_event_get_offsets_<call>() that returns the last
231 * accessible offset of trace fields excluding __dynamic_array bytes
232 */
233int trace_event_get_offsets(struct trace_event_call *call)
234{
235 struct ftrace_event_field *tail;
236 struct list_head *head;
237
238 head = trace_get_fields(call);
239 /*
240 * head->next points to the last field with the largest offset,
241 * since it was added last by trace_define_field()
242 */
243 tail = list_first_entry(head, struct ftrace_event_field, link);
244 return tail->offset + tail->size;
245}
246
247/*
248 * Check if the referenced field is an array and return true,
249 * as arrays are OK to dereference.
250 */
251static bool test_field(const char *fmt, struct trace_event_call *call)
252{
253 struct trace_event_fields *field = call->class->fields_array;
254 const char *array_descriptor;
255 const char *p = fmt;
256 int len;
257
258 if (!(len = str_has_prefix(fmt, "REC->")))
259 return false;
260 fmt += len;
261 for (p = fmt; *p; p++) {
262 if (!isalnum(*p) && *p != '_')
263 break;
264 }
265 len = p - fmt;
266
267 for (; field->type; field++) {
268 if (strncmp(field->name, fmt, len) ||
269 field->name[len])
270 continue;
271 array_descriptor = strchr(field->type, '[');
272 /* This is an array and is OK to dereference. */
273 return array_descriptor != NULL;
274 }
275 return false;
276}
277
278/*
279 * Examine the print fmt of the event looking for unsafe dereference
280 * pointers using %p* that could be recorded in the trace event and
281 * much later referenced after the pointer was freed. Dereferencing
282 * pointers are OK, if it is dereferenced into the event itself.
283 */
284static void test_event_printk(struct trace_event_call *call)
285{
286 u64 dereference_flags = 0;
287 bool first = true;
288 const char *fmt, *c, *r, *a;
289 int parens = 0;
290 char in_quote = 0;
291 int start_arg = 0;
292 int arg = 0;
293 int i;
294
295 fmt = call->print_fmt;
296
297 if (!fmt)
298 return;
299
300 for (i = 0; fmt[i]; i++) {
301 switch (fmt[i]) {
302 case '\\':
303 i++;
304 if (!fmt[i])
305 return;
306 continue;
307 case '"':
308 case '\'':
309 /*
310 * The print fmt starts with a string that
311 * is processed first to find %p* usage,
312 * then after the first string, the print fmt
313 * contains arguments that are used to check
314 * if the dereferenced %p* usage is safe.
315 */
316 if (first) {
317 if (fmt[i] == '\'')
318 continue;
319 if (in_quote) {
320 arg = 0;
321 first = false;
322 /*
323 * If there was no %p* uses
324 * the fmt is OK.
325 */
326 if (!dereference_flags)
327 return;
328 }
329 }
330 if (in_quote) {
331 if (in_quote == fmt[i])
332 in_quote = 0;
333 } else {
334 in_quote = fmt[i];
335 }
336 continue;
337 case '%':
338 if (!first || !in_quote)
339 continue;
340 i++;
341 if (!fmt[i])
342 return;
343 switch (fmt[i]) {
344 case '%':
345 continue;
346 case 'p':
347 /* Find dereferencing fields */
348 switch (fmt[i + 1]) {
349 case 'B': case 'R': case 'r':
350 case 'b': case 'M': case 'm':
351 case 'I': case 'i': case 'E':
352 case 'U': case 'V': case 'N':
353 case 'a': case 'd': case 'D':
354 case 'g': case 't': case 'C':
355 case 'O': case 'f':
356 if (WARN_ONCE(arg == 63,
357 "Too many args for event: %s",
358 trace_event_name(call)))
359 return;
360 dereference_flags |= 1ULL << arg;
361 }
362 break;
363 default:
364 {
365 bool star = false;
366 int j;
367
368 /* Increment arg if %*s exists. */
369 for (j = 0; fmt[i + j]; j++) {
370 if (isdigit(fmt[i + j]) ||
371 fmt[i + j] == '.')
372 continue;
373 if (fmt[i + j] == '*') {
374 star = true;
375 continue;
376 }
377 if ((fmt[i + j] == 's') && star)
378 arg++;
379 break;
380 }
381 break;
382 } /* default */
383
384 } /* switch */
385 arg++;
386 continue;
387 case '(':
388 if (in_quote)
389 continue;
390 parens++;
391 continue;
392 case ')':
393 if (in_quote)
394 continue;
395 parens--;
396 if (WARN_ONCE(parens < 0,
397 "Paren mismatch for event: %s\narg='%s'\n%*s",
398 trace_event_name(call),
399 fmt + start_arg,
400 (i - start_arg) + 5, "^"))
401 return;
402 continue;
403 case ',':
404 if (in_quote || parens)
405 continue;
406 i++;
407 while (isspace(fmt[i]))
408 i++;
409 start_arg = i;
410 if (!(dereference_flags & (1ULL << arg)))
411 goto next_arg;
412
413 /* Find the REC-> in the argument */
414 c = strchr(fmt + i, ',');
415 r = strstr(fmt + i, "REC->");
416 if (r && (!c || r < c)) {
417 /*
418 * Addresses of events on the buffer,
419 * or an array on the buffer is
420 * OK to dereference.
421 * There's ways to fool this, but
422 * this is to catch common mistakes,
423 * not malicious code.
424 */
425 a = strchr(fmt + i, '&');
426 if ((a && (a < r)) || test_field(r, call))
427 dereference_flags &= ~(1ULL << arg);
428 } else if ((r = strstr(fmt + i, "__get_dynamic_array(")) &&
429 (!c || r < c)) {
430 dereference_flags &= ~(1ULL << arg);
431 } else if ((r = strstr(fmt + i, "__get_sockaddr(")) &&
432 (!c || r < c)) {
433 dereference_flags &= ~(1ULL << arg);
434 }
435
436 next_arg:
437 i--;
438 arg++;
439 }
440 }
441
442 /*
443 * If you triggered the below warning, the trace event reported
444 * uses an unsafe dereference pointer %p*. As the data stored
445 * at the trace event time may no longer exist when the trace
446 * event is printed, dereferencing to the original source is
447 * unsafe. The source of the dereference must be copied into the
448 * event itself, and the dereference must access the copy instead.
449 */
450 if (WARN_ON_ONCE(dereference_flags)) {
451 arg = 1;
452 while (!(dereference_flags & 1)) {
453 dereference_flags >>= 1;
454 arg++;
455 }
456 pr_warn("event %s has unsafe dereference of argument %d\n",
457 trace_event_name(call), arg);
458 pr_warn("print_fmt: %s\n", fmt);
459 }
460}
461
462int trace_event_raw_init(struct trace_event_call *call)
463{
464 int id;
465
466 id = register_trace_event(&call->event);
467 if (!id)
468 return -ENODEV;
469
470 test_event_printk(call);
471
472 return 0;
473}
474EXPORT_SYMBOL_GPL(trace_event_raw_init);
475
476bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
477{
478 struct trace_array *tr = trace_file->tr;
479 struct trace_array_cpu *data;
480 struct trace_pid_list *no_pid_list;
481 struct trace_pid_list *pid_list;
482
483 pid_list = rcu_dereference_raw(tr->filtered_pids);
484 no_pid_list = rcu_dereference_raw(tr->filtered_no_pids);
485
486 if (!pid_list && !no_pid_list)
487 return false;
488
489 data = this_cpu_ptr(tr->array_buffer.data);
490
491 return data->ignore_pid;
492}
493EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
494
495void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
496 struct trace_event_file *trace_file,
497 unsigned long len)
498{
499 struct trace_event_call *event_call = trace_file->event_call;
500
501 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
502 trace_event_ignore_this_pid(trace_file))
503 return NULL;
504
505 /*
506 * If CONFIG_PREEMPTION is enabled, then the tracepoint itself disables
507 * preemption (adding one to the preempt_count). Since we are
508 * interested in the preempt_count at the time the tracepoint was
509 * hit, we need to subtract one to offset the increment.
510 */
511 fbuffer->trace_ctx = tracing_gen_ctx_dec();
512 fbuffer->trace_file = trace_file;
513
514 fbuffer->event =
515 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
516 event_call->event.type, len,
517 fbuffer->trace_ctx);
518 if (!fbuffer->event)
519 return NULL;
520
521 fbuffer->regs = NULL;
522 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
523 return fbuffer->entry;
524}
525EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
526
527int trace_event_reg(struct trace_event_call *call,
528 enum trace_reg type, void *data)
529{
530 struct trace_event_file *file = data;
531
532 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
533 switch (type) {
534 case TRACE_REG_REGISTER:
535 return tracepoint_probe_register(call->tp,
536 call->class->probe,
537 file);
538 case TRACE_REG_UNREGISTER:
539 tracepoint_probe_unregister(call->tp,
540 call->class->probe,
541 file);
542 return 0;
543
544#ifdef CONFIG_PERF_EVENTS
545 case TRACE_REG_PERF_REGISTER:
546 return tracepoint_probe_register(call->tp,
547 call->class->perf_probe,
548 call);
549 case TRACE_REG_PERF_UNREGISTER:
550 tracepoint_probe_unregister(call->tp,
551 call->class->perf_probe,
552 call);
553 return 0;
554 case TRACE_REG_PERF_OPEN:
555 case TRACE_REG_PERF_CLOSE:
556 case TRACE_REG_PERF_ADD:
557 case TRACE_REG_PERF_DEL:
558 return 0;
559#endif
560 }
561 return 0;
562}
563EXPORT_SYMBOL_GPL(trace_event_reg);
564
565void trace_event_enable_cmd_record(bool enable)
566{
567 struct trace_event_file *file;
568 struct trace_array *tr;
569
570 lockdep_assert_held(&event_mutex);
571
572 do_for_each_event_file(tr, file) {
573
574 if (!(file->flags & EVENT_FILE_FL_ENABLED))
575 continue;
576
577 if (enable) {
578 tracing_start_cmdline_record();
579 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
580 } else {
581 tracing_stop_cmdline_record();
582 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
583 }
584 } while_for_each_event_file();
585}
586
587void trace_event_enable_tgid_record(bool enable)
588{
589 struct trace_event_file *file;
590 struct trace_array *tr;
591
592 lockdep_assert_held(&event_mutex);
593
594 do_for_each_event_file(tr, file) {
595 if (!(file->flags & EVENT_FILE_FL_ENABLED))
596 continue;
597
598 if (enable) {
599 tracing_start_tgid_record();
600 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
601 } else {
602 tracing_stop_tgid_record();
603 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
604 &file->flags);
605 }
606 } while_for_each_event_file();
607}
608
609static int __ftrace_event_enable_disable(struct trace_event_file *file,
610 int enable, int soft_disable)
611{
612 struct trace_event_call *call = file->event_call;
613 struct trace_array *tr = file->tr;
614 int ret = 0;
615 int disable;
616
617 switch (enable) {
618 case 0:
619 /*
620 * When soft_disable is set and enable is cleared, the sm_ref
621 * reference counter is decremented. If it reaches 0, we want
622 * to clear the SOFT_DISABLED flag but leave the event in the
623 * state that it was. That is, if the event was enabled and
624 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
625 * is set we do not want the event to be enabled before we
626 * clear the bit.
627 *
628 * When soft_disable is not set but the SOFT_MODE flag is,
629 * we do nothing. Do not disable the tracepoint, otherwise
630 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
631 */
632 if (soft_disable) {
633 if (atomic_dec_return(&file->sm_ref) > 0)
634 break;
635 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
636 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
637 /* Disable use of trace_buffered_event */
638 trace_buffered_event_disable();
639 } else
640 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
641
642 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
643 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
644 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
645 tracing_stop_cmdline_record();
646 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
647 }
648
649 if (file->flags & EVENT_FILE_FL_RECORDED_TGID) {
650 tracing_stop_tgid_record();
651 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
652 }
653
654 call->class->reg(call, TRACE_REG_UNREGISTER, file);
655 }
656 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
657 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
658 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
659 else
660 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
661 break;
662 case 1:
663 /*
664 * When soft_disable is set and enable is set, we want to
665 * register the tracepoint for the event, but leave the event
666 * as is. That means, if the event was already enabled, we do
667 * nothing (but set SOFT_MODE). If the event is disabled, we
668 * set SOFT_DISABLED before enabling the event tracepoint, so
669 * it still seems to be disabled.
670 */
671 if (!soft_disable)
672 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
673 else {
674 if (atomic_inc_return(&file->sm_ref) > 1)
675 break;
676 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
677 /* Enable use of trace_buffered_event */
678 trace_buffered_event_enable();
679 }
680
681 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
682 bool cmd = false, tgid = false;
683
684 /* Keep the event disabled, when going to SOFT_MODE. */
685 if (soft_disable)
686 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
687
688 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
689 cmd = true;
690 tracing_start_cmdline_record();
691 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
692 }
693
694 if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
695 tgid = true;
696 tracing_start_tgid_record();
697 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
698 }
699
700 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
701 if (ret) {
702 if (cmd)
703 tracing_stop_cmdline_record();
704 if (tgid)
705 tracing_stop_tgid_record();
706 pr_info("event trace: Could not enable event "
707 "%s\n", trace_event_name(call));
708 break;
709 }
710 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
711
712 /* WAS_ENABLED gets set but never cleared. */
713 set_bit(EVENT_FILE_FL_WAS_ENABLED_BIT, &file->flags);
714 }
715 break;
716 }
717
718 return ret;
719}
720
721int trace_event_enable_disable(struct trace_event_file *file,
722 int enable, int soft_disable)
723{
724 return __ftrace_event_enable_disable(file, enable, soft_disable);
725}
726
727static int ftrace_event_enable_disable(struct trace_event_file *file,
728 int enable)
729{
730 return __ftrace_event_enable_disable(file, enable, 0);
731}
732
733static void ftrace_clear_events(struct trace_array *tr)
734{
735 struct trace_event_file *file;
736
737 mutex_lock(&event_mutex);
738 list_for_each_entry(file, &tr->events, list) {
739 ftrace_event_enable_disable(file, 0);
740 }
741 mutex_unlock(&event_mutex);
742}
743
744static void
745event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
746{
747 struct trace_pid_list *pid_list;
748 struct trace_array *tr = data;
749
750 pid_list = rcu_dereference_raw(tr->filtered_pids);
751 trace_filter_add_remove_task(pid_list, NULL, task);
752
753 pid_list = rcu_dereference_raw(tr->filtered_no_pids);
754 trace_filter_add_remove_task(pid_list, NULL, task);
755}
756
757static void
758event_filter_pid_sched_process_fork(void *data,
759 struct task_struct *self,
760 struct task_struct *task)
761{
762 struct trace_pid_list *pid_list;
763 struct trace_array *tr = data;
764
765 pid_list = rcu_dereference_sched(tr->filtered_pids);
766 trace_filter_add_remove_task(pid_list, self, task);
767
768 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
769 trace_filter_add_remove_task(pid_list, self, task);
770}
771
772void trace_event_follow_fork(struct trace_array *tr, bool enable)
773{
774 if (enable) {
775 register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
776 tr, INT_MIN);
777 register_trace_prio_sched_process_free(event_filter_pid_sched_process_exit,
778 tr, INT_MAX);
779 } else {
780 unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
781 tr);
782 unregister_trace_sched_process_free(event_filter_pid_sched_process_exit,
783 tr);
784 }
785}
786
787static void
788event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
789 struct task_struct *prev,
790 struct task_struct *next,
791 unsigned int prev_state)
792{
793 struct trace_array *tr = data;
794 struct trace_pid_list *no_pid_list;
795 struct trace_pid_list *pid_list;
796 bool ret;
797
798 pid_list = rcu_dereference_sched(tr->filtered_pids);
799 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
800
801 /*
802 * Sched switch is funny, as we only want to ignore it
803 * in the notrace case if both prev and next should be ignored.
804 */
805 ret = trace_ignore_this_task(NULL, no_pid_list, prev) &&
806 trace_ignore_this_task(NULL, no_pid_list, next);
807
808 this_cpu_write(tr->array_buffer.data->ignore_pid, ret ||
809 (trace_ignore_this_task(pid_list, NULL, prev) &&
810 trace_ignore_this_task(pid_list, NULL, next)));
811}
812
813static void
814event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
815 struct task_struct *prev,
816 struct task_struct *next,
817 unsigned int prev_state)
818{
819 struct trace_array *tr = data;
820 struct trace_pid_list *no_pid_list;
821 struct trace_pid_list *pid_list;
822
823 pid_list = rcu_dereference_sched(tr->filtered_pids);
824 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
825
826 this_cpu_write(tr->array_buffer.data->ignore_pid,
827 trace_ignore_this_task(pid_list, no_pid_list, next));
828}
829
830static void
831event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
832{
833 struct trace_array *tr = data;
834 struct trace_pid_list *no_pid_list;
835 struct trace_pid_list *pid_list;
836
837 /* Nothing to do if we are already tracing */
838 if (!this_cpu_read(tr->array_buffer.data->ignore_pid))
839 return;
840
841 pid_list = rcu_dereference_sched(tr->filtered_pids);
842 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
843
844 this_cpu_write(tr->array_buffer.data->ignore_pid,
845 trace_ignore_this_task(pid_list, no_pid_list, task));
846}
847
848static void
849event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
850{
851 struct trace_array *tr = data;
852 struct trace_pid_list *no_pid_list;
853 struct trace_pid_list *pid_list;
854
855 /* Nothing to do if we are not tracing */
856 if (this_cpu_read(tr->array_buffer.data->ignore_pid))
857 return;
858
859 pid_list = rcu_dereference_sched(tr->filtered_pids);
860 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
861
862 /* Set tracing if current is enabled */
863 this_cpu_write(tr->array_buffer.data->ignore_pid,
864 trace_ignore_this_task(pid_list, no_pid_list, current));
865}
866
867static void unregister_pid_events(struct trace_array *tr)
868{
869 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
870 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
871
872 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
873 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
874
875 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
876 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
877
878 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
879 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
880}
881
882static void __ftrace_clear_event_pids(struct trace_array *tr, int type)
883{
884 struct trace_pid_list *pid_list;
885 struct trace_pid_list *no_pid_list;
886 struct trace_event_file *file;
887 int cpu;
888
889 pid_list = rcu_dereference_protected(tr->filtered_pids,
890 lockdep_is_held(&event_mutex));
891 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
892 lockdep_is_held(&event_mutex));
893
894 /* Make sure there's something to do */
895 if (!pid_type_enabled(type, pid_list, no_pid_list))
896 return;
897
898 if (!still_need_pid_events(type, pid_list, no_pid_list)) {
899 unregister_pid_events(tr);
900
901 list_for_each_entry(file, &tr->events, list) {
902 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
903 }
904
905 for_each_possible_cpu(cpu)
906 per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false;
907 }
908
909 if (type & TRACE_PIDS)
910 rcu_assign_pointer(tr->filtered_pids, NULL);
911
912 if (type & TRACE_NO_PIDS)
913 rcu_assign_pointer(tr->filtered_no_pids, NULL);
914
915 /* Wait till all users are no longer using pid filtering */
916 tracepoint_synchronize_unregister();
917
918 if ((type & TRACE_PIDS) && pid_list)
919 trace_pid_list_free(pid_list);
920
921 if ((type & TRACE_NO_PIDS) && no_pid_list)
922 trace_pid_list_free(no_pid_list);
923}
924
925static void ftrace_clear_event_pids(struct trace_array *tr, int type)
926{
927 mutex_lock(&event_mutex);
928 __ftrace_clear_event_pids(tr, type);
929 mutex_unlock(&event_mutex);
930}
931
932static void __put_system(struct event_subsystem *system)
933{
934 struct event_filter *filter = system->filter;
935
936 WARN_ON_ONCE(system_refcount(system) == 0);
937 if (system_refcount_dec(system))
938 return;
939
940 list_del(&system->list);
941
942 if (filter) {
943 kfree(filter->filter_string);
944 kfree(filter);
945 }
946 kfree_const(system->name);
947 kfree(system);
948}
949
950static void __get_system(struct event_subsystem *system)
951{
952 WARN_ON_ONCE(system_refcount(system) == 0);
953 system_refcount_inc(system);
954}
955
956static void __get_system_dir(struct trace_subsystem_dir *dir)
957{
958 WARN_ON_ONCE(dir->ref_count == 0);
959 dir->ref_count++;
960 __get_system(dir->subsystem);
961}
962
963static void __put_system_dir(struct trace_subsystem_dir *dir)
964{
965 WARN_ON_ONCE(dir->ref_count == 0);
966 /* If the subsystem is about to be freed, the dir must be too */
967 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
968
969 __put_system(dir->subsystem);
970 if (!--dir->ref_count)
971 kfree(dir);
972}
973
974static void put_system(struct trace_subsystem_dir *dir)
975{
976 mutex_lock(&event_mutex);
977 __put_system_dir(dir);
978 mutex_unlock(&event_mutex);
979}
980
981static void remove_subsystem(struct trace_subsystem_dir *dir)
982{
983 if (!dir)
984 return;
985
986 if (!--dir->nr_events) {
987 eventfs_remove_dir(dir->ei);
988 list_del(&dir->list);
989 __put_system_dir(dir);
990 }
991}
992
993void event_file_get(struct trace_event_file *file)
994{
995 atomic_inc(&file->ref);
996}
997
998void event_file_put(struct trace_event_file *file)
999{
1000 if (WARN_ON_ONCE(!atomic_read(&file->ref))) {
1001 if (file->flags & EVENT_FILE_FL_FREED)
1002 kmem_cache_free(file_cachep, file);
1003 return;
1004 }
1005
1006 if (atomic_dec_and_test(&file->ref)) {
1007 /* Count should only go to zero when it is freed */
1008 if (WARN_ON_ONCE(!(file->flags & EVENT_FILE_FL_FREED)))
1009 return;
1010 kmem_cache_free(file_cachep, file);
1011 }
1012}
1013
1014static void remove_event_file_dir(struct trace_event_file *file)
1015{
1016 eventfs_remove_dir(file->ei);
1017 list_del(&file->list);
1018 remove_subsystem(file->system);
1019 free_event_filter(file->filter);
1020 file->flags |= EVENT_FILE_FL_FREED;
1021 event_file_put(file);
1022}
1023
1024/*
1025 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
1026 */
1027static int
1028__ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
1029 const char *sub, const char *event, int set)
1030{
1031 struct trace_event_file *file;
1032 struct trace_event_call *call;
1033 const char *name;
1034 int ret = -EINVAL;
1035 int eret = 0;
1036
1037 list_for_each_entry(file, &tr->events, list) {
1038
1039 call = file->event_call;
1040 name = trace_event_name(call);
1041
1042 if (!name || !call->class || !call->class->reg)
1043 continue;
1044
1045 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1046 continue;
1047
1048 if (match &&
1049 strcmp(match, name) != 0 &&
1050 strcmp(match, call->class->system) != 0)
1051 continue;
1052
1053 if (sub && strcmp(sub, call->class->system) != 0)
1054 continue;
1055
1056 if (event && strcmp(event, name) != 0)
1057 continue;
1058
1059 ret = ftrace_event_enable_disable(file, set);
1060
1061 /*
1062 * Save the first error and return that. Some events
1063 * may still have been enabled, but let the user
1064 * know that something went wrong.
1065 */
1066 if (ret && !eret)
1067 eret = ret;
1068
1069 ret = eret;
1070 }
1071
1072 return ret;
1073}
1074
1075static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
1076 const char *sub, const char *event, int set)
1077{
1078 int ret;
1079
1080 mutex_lock(&event_mutex);
1081 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
1082 mutex_unlock(&event_mutex);
1083
1084 return ret;
1085}
1086
1087int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
1088{
1089 char *event = NULL, *sub = NULL, *match;
1090 int ret;
1091
1092 if (!tr)
1093 return -ENOENT;
1094 /*
1095 * The buf format can be <subsystem>:<event-name>
1096 * *:<event-name> means any event by that name.
1097 * :<event-name> is the same.
1098 *
1099 * <subsystem>:* means all events in that subsystem
1100 * <subsystem>: means the same.
1101 *
1102 * <name> (no ':') means all events in a subsystem with
1103 * the name <name> or any event that matches <name>
1104 */
1105
1106 match = strsep(&buf, ":");
1107 if (buf) {
1108 sub = match;
1109 event = buf;
1110 match = NULL;
1111
1112 if (!strlen(sub) || strcmp(sub, "*") == 0)
1113 sub = NULL;
1114 if (!strlen(event) || strcmp(event, "*") == 0)
1115 event = NULL;
1116 }
1117
1118 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
1119
1120 /* Put back the colon to allow this to be called again */
1121 if (buf)
1122 *(buf - 1) = ':';
1123
1124 return ret;
1125}
1126
1127/**
1128 * trace_set_clr_event - enable or disable an event
1129 * @system: system name to match (NULL for any system)
1130 * @event: event name to match (NULL for all events, within system)
1131 * @set: 1 to enable, 0 to disable
1132 *
1133 * This is a way for other parts of the kernel to enable or disable
1134 * event recording.
1135 *
1136 * Returns 0 on success, -EINVAL if the parameters do not match any
1137 * registered events.
1138 */
1139int trace_set_clr_event(const char *system, const char *event, int set)
1140{
1141 struct trace_array *tr = top_trace_array();
1142
1143 if (!tr)
1144 return -ENODEV;
1145
1146 return __ftrace_set_clr_event(tr, NULL, system, event, set);
1147}
1148EXPORT_SYMBOL_GPL(trace_set_clr_event);
1149
1150/**
1151 * trace_array_set_clr_event - enable or disable an event for a trace array.
1152 * @tr: concerned trace array.
1153 * @system: system name to match (NULL for any system)
1154 * @event: event name to match (NULL for all events, within system)
1155 * @enable: true to enable, false to disable
1156 *
1157 * This is a way for other parts of the kernel to enable or disable
1158 * event recording.
1159 *
1160 * Returns 0 on success, -EINVAL if the parameters do not match any
1161 * registered events.
1162 */
1163int trace_array_set_clr_event(struct trace_array *tr, const char *system,
1164 const char *event, bool enable)
1165{
1166 int set;
1167
1168 if (!tr)
1169 return -ENOENT;
1170
1171 set = (enable == true) ? 1 : 0;
1172 return __ftrace_set_clr_event(tr, NULL, system, event, set);
1173}
1174EXPORT_SYMBOL_GPL(trace_array_set_clr_event);
1175
1176/* 128 should be much more than enough */
1177#define EVENT_BUF_SIZE 127
1178
1179static ssize_t
1180ftrace_event_write(struct file *file, const char __user *ubuf,
1181 size_t cnt, loff_t *ppos)
1182{
1183 struct trace_parser parser;
1184 struct seq_file *m = file->private_data;
1185 struct trace_array *tr = m->private;
1186 ssize_t read, ret;
1187
1188 if (!cnt)
1189 return 0;
1190
1191 ret = tracing_update_buffers(tr);
1192 if (ret < 0)
1193 return ret;
1194
1195 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
1196 return -ENOMEM;
1197
1198 read = trace_get_user(&parser, ubuf, cnt, ppos);
1199
1200 if (read >= 0 && trace_parser_loaded((&parser))) {
1201 int set = 1;
1202
1203 if (*parser.buffer == '!')
1204 set = 0;
1205
1206 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
1207 if (ret)
1208 goto out_put;
1209 }
1210
1211 ret = read;
1212
1213 out_put:
1214 trace_parser_put(&parser);
1215
1216 return ret;
1217}
1218
1219static void *
1220t_next(struct seq_file *m, void *v, loff_t *pos)
1221{
1222 struct trace_event_file *file = v;
1223 struct trace_event_call *call;
1224 struct trace_array *tr = m->private;
1225
1226 (*pos)++;
1227
1228 list_for_each_entry_continue(file, &tr->events, list) {
1229 call = file->event_call;
1230 /*
1231 * The ftrace subsystem is for showing formats only.
1232 * They can not be enabled or disabled via the event files.
1233 */
1234 if (call->class && call->class->reg &&
1235 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1236 return file;
1237 }
1238
1239 return NULL;
1240}
1241
1242static void *t_start(struct seq_file *m, loff_t *pos)
1243{
1244 struct trace_event_file *file;
1245 struct trace_array *tr = m->private;
1246 loff_t l;
1247
1248 mutex_lock(&event_mutex);
1249
1250 file = list_entry(&tr->events, struct trace_event_file, list);
1251 for (l = 0; l <= *pos; ) {
1252 file = t_next(m, file, &l);
1253 if (!file)
1254 break;
1255 }
1256 return file;
1257}
1258
1259static void *
1260s_next(struct seq_file *m, void *v, loff_t *pos)
1261{
1262 struct trace_event_file *file = v;
1263 struct trace_array *tr = m->private;
1264
1265 (*pos)++;
1266
1267 list_for_each_entry_continue(file, &tr->events, list) {
1268 if (file->flags & EVENT_FILE_FL_ENABLED)
1269 return file;
1270 }
1271
1272 return NULL;
1273}
1274
1275static void *s_start(struct seq_file *m, loff_t *pos)
1276{
1277 struct trace_event_file *file;
1278 struct trace_array *tr = m->private;
1279 loff_t l;
1280
1281 mutex_lock(&event_mutex);
1282
1283 file = list_entry(&tr->events, struct trace_event_file, list);
1284 for (l = 0; l <= *pos; ) {
1285 file = s_next(m, file, &l);
1286 if (!file)
1287 break;
1288 }
1289 return file;
1290}
1291
1292static int t_show(struct seq_file *m, void *v)
1293{
1294 struct trace_event_file *file = v;
1295 struct trace_event_call *call = file->event_call;
1296
1297 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1298 seq_printf(m, "%s:", call->class->system);
1299 seq_printf(m, "%s\n", trace_event_name(call));
1300
1301 return 0;
1302}
1303
1304static void t_stop(struct seq_file *m, void *p)
1305{
1306 mutex_unlock(&event_mutex);
1307}
1308
1309static void *
1310__next(struct seq_file *m, void *v, loff_t *pos, int type)
1311{
1312 struct trace_array *tr = m->private;
1313 struct trace_pid_list *pid_list;
1314
1315 if (type == TRACE_PIDS)
1316 pid_list = rcu_dereference_sched(tr->filtered_pids);
1317 else
1318 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1319
1320 return trace_pid_next(pid_list, v, pos);
1321}
1322
1323static void *
1324p_next(struct seq_file *m, void *v, loff_t *pos)
1325{
1326 return __next(m, v, pos, TRACE_PIDS);
1327}
1328
1329static void *
1330np_next(struct seq_file *m, void *v, loff_t *pos)
1331{
1332 return __next(m, v, pos, TRACE_NO_PIDS);
1333}
1334
1335static void *__start(struct seq_file *m, loff_t *pos, int type)
1336 __acquires(RCU)
1337{
1338 struct trace_pid_list *pid_list;
1339 struct trace_array *tr = m->private;
1340
1341 /*
1342 * Grab the mutex, to keep calls to p_next() having the same
1343 * tr->filtered_pids as p_start() has.
1344 * If we just passed the tr->filtered_pids around, then RCU would
1345 * have been enough, but doing that makes things more complex.
1346 */
1347 mutex_lock(&event_mutex);
1348 rcu_read_lock_sched();
1349
1350 if (type == TRACE_PIDS)
1351 pid_list = rcu_dereference_sched(tr->filtered_pids);
1352 else
1353 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1354
1355 if (!pid_list)
1356 return NULL;
1357
1358 return trace_pid_start(pid_list, pos);
1359}
1360
1361static void *p_start(struct seq_file *m, loff_t *pos)
1362 __acquires(RCU)
1363{
1364 return __start(m, pos, TRACE_PIDS);
1365}
1366
1367static void *np_start(struct seq_file *m, loff_t *pos)
1368 __acquires(RCU)
1369{
1370 return __start(m, pos, TRACE_NO_PIDS);
1371}
1372
1373static void p_stop(struct seq_file *m, void *p)
1374 __releases(RCU)
1375{
1376 rcu_read_unlock_sched();
1377 mutex_unlock(&event_mutex);
1378}
1379
1380static ssize_t
1381event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1382 loff_t *ppos)
1383{
1384 struct trace_event_file *file;
1385 unsigned long flags;
1386 char buf[4] = "0";
1387
1388 mutex_lock(&event_mutex);
1389 file = event_file_data(filp);
1390 if (likely(file))
1391 flags = file->flags;
1392 mutex_unlock(&event_mutex);
1393
1394 if (!file || flags & EVENT_FILE_FL_FREED)
1395 return -ENODEV;
1396
1397 if (flags & EVENT_FILE_FL_ENABLED &&
1398 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1399 strcpy(buf, "1");
1400
1401 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1402 flags & EVENT_FILE_FL_SOFT_MODE)
1403 strcat(buf, "*");
1404
1405 strcat(buf, "\n");
1406
1407 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1408}
1409
1410static ssize_t
1411event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1412 loff_t *ppos)
1413{
1414 struct trace_event_file *file;
1415 unsigned long val;
1416 int ret;
1417
1418 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1419 if (ret)
1420 return ret;
1421
1422 switch (val) {
1423 case 0:
1424 case 1:
1425 ret = -ENODEV;
1426 mutex_lock(&event_mutex);
1427 file = event_file_data(filp);
1428 if (likely(file && !(file->flags & EVENT_FILE_FL_FREED))) {
1429 ret = tracing_update_buffers(file->tr);
1430 if (ret < 0) {
1431 mutex_unlock(&event_mutex);
1432 return ret;
1433 }
1434 ret = ftrace_event_enable_disable(file, val);
1435 }
1436 mutex_unlock(&event_mutex);
1437 break;
1438
1439 default:
1440 return -EINVAL;
1441 }
1442
1443 *ppos += cnt;
1444
1445 return ret ? ret : cnt;
1446}
1447
1448static ssize_t
1449system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1450 loff_t *ppos)
1451{
1452 const char set_to_char[4] = { '?', '0', '1', 'X' };
1453 struct trace_subsystem_dir *dir = filp->private_data;
1454 struct event_subsystem *system = dir->subsystem;
1455 struct trace_event_call *call;
1456 struct trace_event_file *file;
1457 struct trace_array *tr = dir->tr;
1458 char buf[2];
1459 int set = 0;
1460 int ret;
1461
1462 mutex_lock(&event_mutex);
1463 list_for_each_entry(file, &tr->events, list) {
1464 call = file->event_call;
1465 if ((call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) ||
1466 !trace_event_name(call) || !call->class || !call->class->reg)
1467 continue;
1468
1469 if (system && strcmp(call->class->system, system->name) != 0)
1470 continue;
1471
1472 /*
1473 * We need to find out if all the events are set
1474 * or if all events or cleared, or if we have
1475 * a mixture.
1476 */
1477 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1478
1479 /*
1480 * If we have a mixture, no need to look further.
1481 */
1482 if (set == 3)
1483 break;
1484 }
1485 mutex_unlock(&event_mutex);
1486
1487 buf[0] = set_to_char[set];
1488 buf[1] = '\n';
1489
1490 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1491
1492 return ret;
1493}
1494
1495static ssize_t
1496system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1497 loff_t *ppos)
1498{
1499 struct trace_subsystem_dir *dir = filp->private_data;
1500 struct event_subsystem *system = dir->subsystem;
1501 const char *name = NULL;
1502 unsigned long val;
1503 ssize_t ret;
1504
1505 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1506 if (ret)
1507 return ret;
1508
1509 ret = tracing_update_buffers(dir->tr);
1510 if (ret < 0)
1511 return ret;
1512
1513 if (val != 0 && val != 1)
1514 return -EINVAL;
1515
1516 /*
1517 * Opening of "enable" adds a ref count to system,
1518 * so the name is safe to use.
1519 */
1520 if (system)
1521 name = system->name;
1522
1523 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1524 if (ret)
1525 goto out;
1526
1527 ret = cnt;
1528
1529out:
1530 *ppos += cnt;
1531
1532 return ret;
1533}
1534
1535enum {
1536 FORMAT_HEADER = 1,
1537 FORMAT_FIELD_SEPERATOR = 2,
1538 FORMAT_PRINTFMT = 3,
1539};
1540
1541static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1542{
1543 struct trace_event_call *call = event_file_data(m->private);
1544 struct list_head *common_head = &ftrace_common_fields;
1545 struct list_head *head = trace_get_fields(call);
1546 struct list_head *node = v;
1547
1548 (*pos)++;
1549
1550 switch ((unsigned long)v) {
1551 case FORMAT_HEADER:
1552 node = common_head;
1553 break;
1554
1555 case FORMAT_FIELD_SEPERATOR:
1556 node = head;
1557 break;
1558
1559 case FORMAT_PRINTFMT:
1560 /* all done */
1561 return NULL;
1562 }
1563
1564 node = node->prev;
1565 if (node == common_head)
1566 return (void *)FORMAT_FIELD_SEPERATOR;
1567 else if (node == head)
1568 return (void *)FORMAT_PRINTFMT;
1569 else
1570 return node;
1571}
1572
1573static int f_show(struct seq_file *m, void *v)
1574{
1575 struct trace_event_call *call = event_file_data(m->private);
1576 struct ftrace_event_field *field;
1577 const char *array_descriptor;
1578
1579 switch ((unsigned long)v) {
1580 case FORMAT_HEADER:
1581 seq_printf(m, "name: %s\n", trace_event_name(call));
1582 seq_printf(m, "ID: %d\n", call->event.type);
1583 seq_puts(m, "format:\n");
1584 return 0;
1585
1586 case FORMAT_FIELD_SEPERATOR:
1587 seq_putc(m, '\n');
1588 return 0;
1589
1590 case FORMAT_PRINTFMT:
1591 seq_printf(m, "\nprint fmt: %s\n",
1592 call->print_fmt);
1593 return 0;
1594 }
1595
1596 field = list_entry(v, struct ftrace_event_field, link);
1597 /*
1598 * Smartly shows the array type(except dynamic array).
1599 * Normal:
1600 * field:TYPE VAR
1601 * If TYPE := TYPE[LEN], it is shown:
1602 * field:TYPE VAR[LEN]
1603 */
1604 array_descriptor = strchr(field->type, '[');
1605
1606 if (str_has_prefix(field->type, "__data_loc"))
1607 array_descriptor = NULL;
1608
1609 if (!array_descriptor)
1610 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1611 field->type, field->name, field->offset,
1612 field->size, !!field->is_signed);
1613 else if (field->len)
1614 seq_printf(m, "\tfield:%.*s %s[%d];\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1615 (int)(array_descriptor - field->type),
1616 field->type, field->name,
1617 field->len, field->offset,
1618 field->size, !!field->is_signed);
1619 else
1620 seq_printf(m, "\tfield:%.*s %s[];\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1621 (int)(array_descriptor - field->type),
1622 field->type, field->name,
1623 field->offset, field->size, !!field->is_signed);
1624
1625 return 0;
1626}
1627
1628static void *f_start(struct seq_file *m, loff_t *pos)
1629{
1630 void *p = (void *)FORMAT_HEADER;
1631 loff_t l = 0;
1632
1633 /* ->stop() is called even if ->start() fails */
1634 mutex_lock(&event_mutex);
1635 if (!event_file_data(m->private))
1636 return ERR_PTR(-ENODEV);
1637
1638 while (l < *pos && p)
1639 p = f_next(m, p, &l);
1640
1641 return p;
1642}
1643
1644static void f_stop(struct seq_file *m, void *p)
1645{
1646 mutex_unlock(&event_mutex);
1647}
1648
1649static const struct seq_operations trace_format_seq_ops = {
1650 .start = f_start,
1651 .next = f_next,
1652 .stop = f_stop,
1653 .show = f_show,
1654};
1655
1656static int trace_format_open(struct inode *inode, struct file *file)
1657{
1658 struct seq_file *m;
1659 int ret;
1660
1661 /* Do we want to hide event format files on tracefs lockdown? */
1662
1663 ret = seq_open(file, &trace_format_seq_ops);
1664 if (ret < 0)
1665 return ret;
1666
1667 m = file->private_data;
1668 m->private = file;
1669
1670 return 0;
1671}
1672
1673static ssize_t
1674event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1675{
1676 int id = (long)event_file_data(filp);
1677 char buf[32];
1678 int len;
1679
1680 if (unlikely(!id))
1681 return -ENODEV;
1682
1683 len = sprintf(buf, "%d\n", id);
1684
1685 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1686}
1687
1688static ssize_t
1689event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1690 loff_t *ppos)
1691{
1692 struct trace_event_file *file;
1693 struct trace_seq *s;
1694 int r = -ENODEV;
1695
1696 if (*ppos)
1697 return 0;
1698
1699 s = kmalloc(sizeof(*s), GFP_KERNEL);
1700
1701 if (!s)
1702 return -ENOMEM;
1703
1704 trace_seq_init(s);
1705
1706 mutex_lock(&event_mutex);
1707 file = event_file_data(filp);
1708 if (file && !(file->flags & EVENT_FILE_FL_FREED))
1709 print_event_filter(file, s);
1710 mutex_unlock(&event_mutex);
1711
1712 if (file)
1713 r = simple_read_from_buffer(ubuf, cnt, ppos,
1714 s->buffer, trace_seq_used(s));
1715
1716 kfree(s);
1717
1718 return r;
1719}
1720
1721static ssize_t
1722event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1723 loff_t *ppos)
1724{
1725 struct trace_event_file *file;
1726 char *buf;
1727 int err = -ENODEV;
1728
1729 if (cnt >= PAGE_SIZE)
1730 return -EINVAL;
1731
1732 buf = memdup_user_nul(ubuf, cnt);
1733 if (IS_ERR(buf))
1734 return PTR_ERR(buf);
1735
1736 mutex_lock(&event_mutex);
1737 file = event_file_data(filp);
1738 if (file)
1739 err = apply_event_filter(file, buf);
1740 mutex_unlock(&event_mutex);
1741
1742 kfree(buf);
1743 if (err < 0)
1744 return err;
1745
1746 *ppos += cnt;
1747
1748 return cnt;
1749}
1750
1751static LIST_HEAD(event_subsystems);
1752
1753static int subsystem_open(struct inode *inode, struct file *filp)
1754{
1755 struct trace_subsystem_dir *dir = NULL, *iter_dir;
1756 struct trace_array *tr = NULL, *iter_tr;
1757 struct event_subsystem *system = NULL;
1758 int ret;
1759
1760 if (tracing_is_disabled())
1761 return -ENODEV;
1762
1763 /* Make sure the system still exists */
1764 mutex_lock(&event_mutex);
1765 mutex_lock(&trace_types_lock);
1766 list_for_each_entry(iter_tr, &ftrace_trace_arrays, list) {
1767 list_for_each_entry(iter_dir, &iter_tr->systems, list) {
1768 if (iter_dir == inode->i_private) {
1769 /* Don't open systems with no events */
1770 tr = iter_tr;
1771 dir = iter_dir;
1772 if (dir->nr_events) {
1773 __get_system_dir(dir);
1774 system = dir->subsystem;
1775 }
1776 goto exit_loop;
1777 }
1778 }
1779 }
1780 exit_loop:
1781 mutex_unlock(&trace_types_lock);
1782 mutex_unlock(&event_mutex);
1783
1784 if (!system)
1785 return -ENODEV;
1786
1787 /* Still need to increment the ref count of the system */
1788 if (trace_array_get(tr) < 0) {
1789 put_system(dir);
1790 return -ENODEV;
1791 }
1792
1793 ret = tracing_open_generic(inode, filp);
1794 if (ret < 0) {
1795 trace_array_put(tr);
1796 put_system(dir);
1797 }
1798
1799 return ret;
1800}
1801
1802static int system_tr_open(struct inode *inode, struct file *filp)
1803{
1804 struct trace_subsystem_dir *dir;
1805 struct trace_array *tr = inode->i_private;
1806 int ret;
1807
1808 /* Make a temporary dir that has no system but points to tr */
1809 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1810 if (!dir)
1811 return -ENOMEM;
1812
1813 ret = tracing_open_generic_tr(inode, filp);
1814 if (ret < 0) {
1815 kfree(dir);
1816 return ret;
1817 }
1818 dir->tr = tr;
1819 filp->private_data = dir;
1820
1821 return 0;
1822}
1823
1824static int subsystem_release(struct inode *inode, struct file *file)
1825{
1826 struct trace_subsystem_dir *dir = file->private_data;
1827
1828 trace_array_put(dir->tr);
1829
1830 /*
1831 * If dir->subsystem is NULL, then this is a temporary
1832 * descriptor that was made for a trace_array to enable
1833 * all subsystems.
1834 */
1835 if (dir->subsystem)
1836 put_system(dir);
1837 else
1838 kfree(dir);
1839
1840 return 0;
1841}
1842
1843static ssize_t
1844subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1845 loff_t *ppos)
1846{
1847 struct trace_subsystem_dir *dir = filp->private_data;
1848 struct event_subsystem *system = dir->subsystem;
1849 struct trace_seq *s;
1850 int r;
1851
1852 if (*ppos)
1853 return 0;
1854
1855 s = kmalloc(sizeof(*s), GFP_KERNEL);
1856 if (!s)
1857 return -ENOMEM;
1858
1859 trace_seq_init(s);
1860
1861 print_subsystem_event_filter(system, s);
1862 r = simple_read_from_buffer(ubuf, cnt, ppos,
1863 s->buffer, trace_seq_used(s));
1864
1865 kfree(s);
1866
1867 return r;
1868}
1869
1870static ssize_t
1871subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1872 loff_t *ppos)
1873{
1874 struct trace_subsystem_dir *dir = filp->private_data;
1875 char *buf;
1876 int err;
1877
1878 if (cnt >= PAGE_SIZE)
1879 return -EINVAL;
1880
1881 buf = memdup_user_nul(ubuf, cnt);
1882 if (IS_ERR(buf))
1883 return PTR_ERR(buf);
1884
1885 err = apply_subsystem_event_filter(dir, buf);
1886 kfree(buf);
1887 if (err < 0)
1888 return err;
1889
1890 *ppos += cnt;
1891
1892 return cnt;
1893}
1894
1895static ssize_t
1896show_header_page_file(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1897{
1898 struct trace_array *tr = filp->private_data;
1899 struct trace_seq *s;
1900 int r;
1901
1902 if (*ppos)
1903 return 0;
1904
1905 s = kmalloc(sizeof(*s), GFP_KERNEL);
1906 if (!s)
1907 return -ENOMEM;
1908
1909 trace_seq_init(s);
1910
1911 ring_buffer_print_page_header(tr->array_buffer.buffer, s);
1912 r = simple_read_from_buffer(ubuf, cnt, ppos,
1913 s->buffer, trace_seq_used(s));
1914
1915 kfree(s);
1916
1917 return r;
1918}
1919
1920static ssize_t
1921show_header_event_file(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1922{
1923 struct trace_seq *s;
1924 int r;
1925
1926 if (*ppos)
1927 return 0;
1928
1929 s = kmalloc(sizeof(*s), GFP_KERNEL);
1930 if (!s)
1931 return -ENOMEM;
1932
1933 trace_seq_init(s);
1934
1935 ring_buffer_print_entry_header(s);
1936 r = simple_read_from_buffer(ubuf, cnt, ppos,
1937 s->buffer, trace_seq_used(s));
1938
1939 kfree(s);
1940
1941 return r;
1942}
1943
1944static void ignore_task_cpu(void *data)
1945{
1946 struct trace_array *tr = data;
1947 struct trace_pid_list *pid_list;
1948 struct trace_pid_list *no_pid_list;
1949
1950 /*
1951 * This function is called by on_each_cpu() while the
1952 * event_mutex is held.
1953 */
1954 pid_list = rcu_dereference_protected(tr->filtered_pids,
1955 mutex_is_locked(&event_mutex));
1956 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
1957 mutex_is_locked(&event_mutex));
1958
1959 this_cpu_write(tr->array_buffer.data->ignore_pid,
1960 trace_ignore_this_task(pid_list, no_pid_list, current));
1961}
1962
1963static void register_pid_events(struct trace_array *tr)
1964{
1965 /*
1966 * Register a probe that is called before all other probes
1967 * to set ignore_pid if next or prev do not match.
1968 * Register a probe this is called after all other probes
1969 * to only keep ignore_pid set if next pid matches.
1970 */
1971 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1972 tr, INT_MAX);
1973 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1974 tr, 0);
1975
1976 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1977 tr, INT_MAX);
1978 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1979 tr, 0);
1980
1981 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1982 tr, INT_MAX);
1983 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1984 tr, 0);
1985
1986 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1987 tr, INT_MAX);
1988 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1989 tr, 0);
1990}
1991
1992static ssize_t
1993event_pid_write(struct file *filp, const char __user *ubuf,
1994 size_t cnt, loff_t *ppos, int type)
1995{
1996 struct seq_file *m = filp->private_data;
1997 struct trace_array *tr = m->private;
1998 struct trace_pid_list *filtered_pids = NULL;
1999 struct trace_pid_list *other_pids = NULL;
2000 struct trace_pid_list *pid_list;
2001 struct trace_event_file *file;
2002 ssize_t ret;
2003
2004 if (!cnt)
2005 return 0;
2006
2007 ret = tracing_update_buffers(tr);
2008 if (ret < 0)
2009 return ret;
2010
2011 mutex_lock(&event_mutex);
2012
2013 if (type == TRACE_PIDS) {
2014 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
2015 lockdep_is_held(&event_mutex));
2016 other_pids = rcu_dereference_protected(tr->filtered_no_pids,
2017 lockdep_is_held(&event_mutex));
2018 } else {
2019 filtered_pids = rcu_dereference_protected(tr->filtered_no_pids,
2020 lockdep_is_held(&event_mutex));
2021 other_pids = rcu_dereference_protected(tr->filtered_pids,
2022 lockdep_is_held(&event_mutex));
2023 }
2024
2025 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
2026 if (ret < 0)
2027 goto out;
2028
2029 if (type == TRACE_PIDS)
2030 rcu_assign_pointer(tr->filtered_pids, pid_list);
2031 else
2032 rcu_assign_pointer(tr->filtered_no_pids, pid_list);
2033
2034 list_for_each_entry(file, &tr->events, list) {
2035 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
2036 }
2037
2038 if (filtered_pids) {
2039 tracepoint_synchronize_unregister();
2040 trace_pid_list_free(filtered_pids);
2041 } else if (pid_list && !other_pids) {
2042 register_pid_events(tr);
2043 }
2044
2045 /*
2046 * Ignoring of pids is done at task switch. But we have to
2047 * check for those tasks that are currently running.
2048 * Always do this in case a pid was appended or removed.
2049 */
2050 on_each_cpu(ignore_task_cpu, tr, 1);
2051
2052 out:
2053 mutex_unlock(&event_mutex);
2054
2055 if (ret > 0)
2056 *ppos += ret;
2057
2058 return ret;
2059}
2060
2061static ssize_t
2062ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
2063 size_t cnt, loff_t *ppos)
2064{
2065 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
2066}
2067
2068static ssize_t
2069ftrace_event_npid_write(struct file *filp, const char __user *ubuf,
2070 size_t cnt, loff_t *ppos)
2071{
2072 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
2073}
2074
2075static int ftrace_event_avail_open(struct inode *inode, struct file *file);
2076static int ftrace_event_set_open(struct inode *inode, struct file *file);
2077static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
2078static int ftrace_event_set_npid_open(struct inode *inode, struct file *file);
2079static int ftrace_event_release(struct inode *inode, struct file *file);
2080
2081static const struct seq_operations show_event_seq_ops = {
2082 .start = t_start,
2083 .next = t_next,
2084 .show = t_show,
2085 .stop = t_stop,
2086};
2087
2088static const struct seq_operations show_set_event_seq_ops = {
2089 .start = s_start,
2090 .next = s_next,
2091 .show = t_show,
2092 .stop = t_stop,
2093};
2094
2095static const struct seq_operations show_set_pid_seq_ops = {
2096 .start = p_start,
2097 .next = p_next,
2098 .show = trace_pid_show,
2099 .stop = p_stop,
2100};
2101
2102static const struct seq_operations show_set_no_pid_seq_ops = {
2103 .start = np_start,
2104 .next = np_next,
2105 .show = trace_pid_show,
2106 .stop = p_stop,
2107};
2108
2109static const struct file_operations ftrace_avail_fops = {
2110 .open = ftrace_event_avail_open,
2111 .read = seq_read,
2112 .llseek = seq_lseek,
2113 .release = seq_release,
2114};
2115
2116static const struct file_operations ftrace_set_event_fops = {
2117 .open = ftrace_event_set_open,
2118 .read = seq_read,
2119 .write = ftrace_event_write,
2120 .llseek = seq_lseek,
2121 .release = ftrace_event_release,
2122};
2123
2124static const struct file_operations ftrace_set_event_pid_fops = {
2125 .open = ftrace_event_set_pid_open,
2126 .read = seq_read,
2127 .write = ftrace_event_pid_write,
2128 .llseek = seq_lseek,
2129 .release = ftrace_event_release,
2130};
2131
2132static const struct file_operations ftrace_set_event_notrace_pid_fops = {
2133 .open = ftrace_event_set_npid_open,
2134 .read = seq_read,
2135 .write = ftrace_event_npid_write,
2136 .llseek = seq_lseek,
2137 .release = ftrace_event_release,
2138};
2139
2140static const struct file_operations ftrace_enable_fops = {
2141 .open = tracing_open_file_tr,
2142 .read = event_enable_read,
2143 .write = event_enable_write,
2144 .release = tracing_release_file_tr,
2145 .llseek = default_llseek,
2146};
2147
2148static const struct file_operations ftrace_event_format_fops = {
2149 .open = trace_format_open,
2150 .read = seq_read,
2151 .llseek = seq_lseek,
2152 .release = seq_release,
2153};
2154
2155static const struct file_operations ftrace_event_id_fops = {
2156 .read = event_id_read,
2157 .llseek = default_llseek,
2158};
2159
2160static const struct file_operations ftrace_event_filter_fops = {
2161 .open = tracing_open_file_tr,
2162 .read = event_filter_read,
2163 .write = event_filter_write,
2164 .release = tracing_release_file_tr,
2165 .llseek = default_llseek,
2166};
2167
2168static const struct file_operations ftrace_subsystem_filter_fops = {
2169 .open = subsystem_open,
2170 .read = subsystem_filter_read,
2171 .write = subsystem_filter_write,
2172 .llseek = default_llseek,
2173 .release = subsystem_release,
2174};
2175
2176static const struct file_operations ftrace_system_enable_fops = {
2177 .open = subsystem_open,
2178 .read = system_enable_read,
2179 .write = system_enable_write,
2180 .llseek = default_llseek,
2181 .release = subsystem_release,
2182};
2183
2184static const struct file_operations ftrace_tr_enable_fops = {
2185 .open = system_tr_open,
2186 .read = system_enable_read,
2187 .write = system_enable_write,
2188 .llseek = default_llseek,
2189 .release = subsystem_release,
2190};
2191
2192static const struct file_operations ftrace_show_header_page_fops = {
2193 .open = tracing_open_generic_tr,
2194 .read = show_header_page_file,
2195 .llseek = default_llseek,
2196 .release = tracing_release_generic_tr,
2197};
2198
2199static const struct file_operations ftrace_show_header_event_fops = {
2200 .open = tracing_open_generic_tr,
2201 .read = show_header_event_file,
2202 .llseek = default_llseek,
2203 .release = tracing_release_generic_tr,
2204};
2205
2206static int
2207ftrace_event_open(struct inode *inode, struct file *file,
2208 const struct seq_operations *seq_ops)
2209{
2210 struct seq_file *m;
2211 int ret;
2212
2213 ret = security_locked_down(LOCKDOWN_TRACEFS);
2214 if (ret)
2215 return ret;
2216
2217 ret = seq_open(file, seq_ops);
2218 if (ret < 0)
2219 return ret;
2220 m = file->private_data;
2221 /* copy tr over to seq ops */
2222 m->private = inode->i_private;
2223
2224 return ret;
2225}
2226
2227static int ftrace_event_release(struct inode *inode, struct file *file)
2228{
2229 struct trace_array *tr = inode->i_private;
2230
2231 trace_array_put(tr);
2232
2233 return seq_release(inode, file);
2234}
2235
2236static int
2237ftrace_event_avail_open(struct inode *inode, struct file *file)
2238{
2239 const struct seq_operations *seq_ops = &show_event_seq_ops;
2240
2241 /* Checks for tracefs lockdown */
2242 return ftrace_event_open(inode, file, seq_ops);
2243}
2244
2245static int
2246ftrace_event_set_open(struct inode *inode, struct file *file)
2247{
2248 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
2249 struct trace_array *tr = inode->i_private;
2250 int ret;
2251
2252 ret = tracing_check_open_get_tr(tr);
2253 if (ret)
2254 return ret;
2255
2256 if ((file->f_mode & FMODE_WRITE) &&
2257 (file->f_flags & O_TRUNC))
2258 ftrace_clear_events(tr);
2259
2260 ret = ftrace_event_open(inode, file, seq_ops);
2261 if (ret < 0)
2262 trace_array_put(tr);
2263 return ret;
2264}
2265
2266static int
2267ftrace_event_set_pid_open(struct inode *inode, struct file *file)
2268{
2269 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
2270 struct trace_array *tr = inode->i_private;
2271 int ret;
2272
2273 ret = tracing_check_open_get_tr(tr);
2274 if (ret)
2275 return ret;
2276
2277 if ((file->f_mode & FMODE_WRITE) &&
2278 (file->f_flags & O_TRUNC))
2279 ftrace_clear_event_pids(tr, TRACE_PIDS);
2280
2281 ret = ftrace_event_open(inode, file, seq_ops);
2282 if (ret < 0)
2283 trace_array_put(tr);
2284 return ret;
2285}
2286
2287static int
2288ftrace_event_set_npid_open(struct inode *inode, struct file *file)
2289{
2290 const struct seq_operations *seq_ops = &show_set_no_pid_seq_ops;
2291 struct trace_array *tr = inode->i_private;
2292 int ret;
2293
2294 ret = tracing_check_open_get_tr(tr);
2295 if (ret)
2296 return ret;
2297
2298 if ((file->f_mode & FMODE_WRITE) &&
2299 (file->f_flags & O_TRUNC))
2300 ftrace_clear_event_pids(tr, TRACE_NO_PIDS);
2301
2302 ret = ftrace_event_open(inode, file, seq_ops);
2303 if (ret < 0)
2304 trace_array_put(tr);
2305 return ret;
2306}
2307
2308static struct event_subsystem *
2309create_new_subsystem(const char *name)
2310{
2311 struct event_subsystem *system;
2312
2313 /* need to create new entry */
2314 system = kmalloc(sizeof(*system), GFP_KERNEL);
2315 if (!system)
2316 return NULL;
2317
2318 system->ref_count = 1;
2319
2320 /* Only allocate if dynamic (kprobes and modules) */
2321 system->name = kstrdup_const(name, GFP_KERNEL);
2322 if (!system->name)
2323 goto out_free;
2324
2325 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
2326 if (!system->filter)
2327 goto out_free;
2328
2329 list_add(&system->list, &event_subsystems);
2330
2331 return system;
2332
2333 out_free:
2334 kfree_const(system->name);
2335 kfree(system);
2336 return NULL;
2337}
2338
2339static int system_callback(const char *name, umode_t *mode, void **data,
2340 const struct file_operations **fops)
2341{
2342 if (strcmp(name, "filter") == 0)
2343 *fops = &ftrace_subsystem_filter_fops;
2344
2345 else if (strcmp(name, "enable") == 0)
2346 *fops = &ftrace_system_enable_fops;
2347
2348 else
2349 return 0;
2350
2351 *mode = TRACE_MODE_WRITE;
2352 return 1;
2353}
2354
2355static struct eventfs_inode *
2356event_subsystem_dir(struct trace_array *tr, const char *name,
2357 struct trace_event_file *file, struct eventfs_inode *parent)
2358{
2359 struct event_subsystem *system, *iter;
2360 struct trace_subsystem_dir *dir;
2361 struct eventfs_inode *ei;
2362 int nr_entries;
2363 static struct eventfs_entry system_entries[] = {
2364 {
2365 .name = "filter",
2366 .callback = system_callback,
2367 },
2368 {
2369 .name = "enable",
2370 .callback = system_callback,
2371 }
2372 };
2373
2374 /* First see if we did not already create this dir */
2375 list_for_each_entry(dir, &tr->systems, list) {
2376 system = dir->subsystem;
2377 if (strcmp(system->name, name) == 0) {
2378 dir->nr_events++;
2379 file->system = dir;
2380 return dir->ei;
2381 }
2382 }
2383
2384 /* Now see if the system itself exists. */
2385 system = NULL;
2386 list_for_each_entry(iter, &event_subsystems, list) {
2387 if (strcmp(iter->name, name) == 0) {
2388 system = iter;
2389 break;
2390 }
2391 }
2392
2393 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
2394 if (!dir)
2395 goto out_fail;
2396
2397 if (!system) {
2398 system = create_new_subsystem(name);
2399 if (!system)
2400 goto out_free;
2401 } else
2402 __get_system(system);
2403
2404 /* ftrace only has directories no files */
2405 if (strcmp(name, "ftrace") == 0)
2406 nr_entries = 0;
2407 else
2408 nr_entries = ARRAY_SIZE(system_entries);
2409
2410 ei = eventfs_create_dir(name, parent, system_entries, nr_entries, dir);
2411 if (IS_ERR(ei)) {
2412 pr_warn("Failed to create system directory %s\n", name);
2413 __put_system(system);
2414 goto out_free;
2415 }
2416
2417 dir->ei = ei;
2418 dir->tr = tr;
2419 dir->ref_count = 1;
2420 dir->nr_events = 1;
2421 dir->subsystem = system;
2422 file->system = dir;
2423
2424 list_add(&dir->list, &tr->systems);
2425
2426 return dir->ei;
2427
2428 out_free:
2429 kfree(dir);
2430 out_fail:
2431 /* Only print this message if failed on memory allocation */
2432 if (!dir || !system)
2433 pr_warn("No memory to create event subsystem %s\n", name);
2434 return NULL;
2435}
2436
2437static int
2438event_define_fields(struct trace_event_call *call)
2439{
2440 struct list_head *head;
2441 int ret = 0;
2442
2443 /*
2444 * Other events may have the same class. Only update
2445 * the fields if they are not already defined.
2446 */
2447 head = trace_get_fields(call);
2448 if (list_empty(head)) {
2449 struct trace_event_fields *field = call->class->fields_array;
2450 unsigned int offset = sizeof(struct trace_entry);
2451
2452 for (; field->type; field++) {
2453 if (field->type == TRACE_FUNCTION_TYPE) {
2454 field->define_fields(call);
2455 break;
2456 }
2457
2458 offset = ALIGN(offset, field->align);
2459 ret = trace_define_field_ext(call, field->type, field->name,
2460 offset, field->size,
2461 field->is_signed, field->filter_type,
2462 field->len);
2463 if (WARN_ON_ONCE(ret)) {
2464 pr_err("error code is %d\n", ret);
2465 break;
2466 }
2467
2468 offset += field->size;
2469 }
2470 }
2471
2472 return ret;
2473}
2474
2475static int event_callback(const char *name, umode_t *mode, void **data,
2476 const struct file_operations **fops)
2477{
2478 struct trace_event_file *file = *data;
2479 struct trace_event_call *call = file->event_call;
2480
2481 if (strcmp(name, "format") == 0) {
2482 *mode = TRACE_MODE_READ;
2483 *fops = &ftrace_event_format_fops;
2484 *data = call;
2485 return 1;
2486 }
2487
2488 /*
2489 * Only event directories that can be enabled should have
2490 * triggers or filters, with the exception of the "print"
2491 * event that can have a "trigger" file.
2492 */
2493 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
2494 if (call->class->reg && strcmp(name, "enable") == 0) {
2495 *mode = TRACE_MODE_WRITE;
2496 *fops = &ftrace_enable_fops;
2497 return 1;
2498 }
2499
2500 if (strcmp(name, "filter") == 0) {
2501 *mode = TRACE_MODE_WRITE;
2502 *fops = &ftrace_event_filter_fops;
2503 return 1;
2504 }
2505 }
2506
2507 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) ||
2508 strcmp(trace_event_name(call), "print") == 0) {
2509 if (strcmp(name, "trigger") == 0) {
2510 *mode = TRACE_MODE_WRITE;
2511 *fops = &event_trigger_fops;
2512 return 1;
2513 }
2514 }
2515
2516#ifdef CONFIG_PERF_EVENTS
2517 if (call->event.type && call->class->reg &&
2518 strcmp(name, "id") == 0) {
2519 *mode = TRACE_MODE_READ;
2520 *data = (void *)(long)call->event.type;
2521 *fops = &ftrace_event_id_fops;
2522 return 1;
2523 }
2524#endif
2525
2526#ifdef CONFIG_HIST_TRIGGERS
2527 if (strcmp(name, "hist") == 0) {
2528 *mode = TRACE_MODE_READ;
2529 *fops = &event_hist_fops;
2530 return 1;
2531 }
2532#endif
2533#ifdef CONFIG_HIST_TRIGGERS_DEBUG
2534 if (strcmp(name, "hist_debug") == 0) {
2535 *mode = TRACE_MODE_READ;
2536 *fops = &event_hist_debug_fops;
2537 return 1;
2538 }
2539#endif
2540#ifdef CONFIG_TRACE_EVENT_INJECT
2541 if (call->event.type && call->class->reg &&
2542 strcmp(name, "inject") == 0) {
2543 *mode = 0200;
2544 *fops = &event_inject_fops;
2545 return 1;
2546 }
2547#endif
2548 return 0;
2549}
2550
2551static int
2552event_create_dir(struct eventfs_inode *parent, struct trace_event_file *file)
2553{
2554 struct trace_event_call *call = file->event_call;
2555 struct trace_array *tr = file->tr;
2556 struct eventfs_inode *e_events;
2557 struct eventfs_inode *ei;
2558 const char *name;
2559 int nr_entries;
2560 int ret;
2561 static struct eventfs_entry event_entries[] = {
2562 {
2563 .name = "enable",
2564 .callback = event_callback,
2565 },
2566 {
2567 .name = "filter",
2568 .callback = event_callback,
2569 },
2570 {
2571 .name = "trigger",
2572 .callback = event_callback,
2573 },
2574 {
2575 .name = "format",
2576 .callback = event_callback,
2577 },
2578#ifdef CONFIG_PERF_EVENTS
2579 {
2580 .name = "id",
2581 .callback = event_callback,
2582 },
2583#endif
2584#ifdef CONFIG_HIST_TRIGGERS
2585 {
2586 .name = "hist",
2587 .callback = event_callback,
2588 },
2589#endif
2590#ifdef CONFIG_HIST_TRIGGERS_DEBUG
2591 {
2592 .name = "hist_debug",
2593 .callback = event_callback,
2594 },
2595#endif
2596#ifdef CONFIG_TRACE_EVENT_INJECT
2597 {
2598 .name = "inject",
2599 .callback = event_callback,
2600 },
2601#endif
2602 };
2603
2604 /*
2605 * If the trace point header did not define TRACE_SYSTEM
2606 * then the system would be called "TRACE_SYSTEM". This should
2607 * never happen.
2608 */
2609 if (WARN_ON_ONCE(strcmp(call->class->system, TRACE_SYSTEM) == 0))
2610 return -ENODEV;
2611
2612 e_events = event_subsystem_dir(tr, call->class->system, file, parent);
2613 if (!e_events)
2614 return -ENOMEM;
2615
2616 nr_entries = ARRAY_SIZE(event_entries);
2617
2618 name = trace_event_name(call);
2619 ei = eventfs_create_dir(name, e_events, event_entries, nr_entries, file);
2620 if (IS_ERR(ei)) {
2621 pr_warn("Could not create tracefs '%s' directory\n", name);
2622 return -1;
2623 }
2624
2625 file->ei = ei;
2626
2627 ret = event_define_fields(call);
2628 if (ret < 0) {
2629 pr_warn("Could not initialize trace point events/%s\n", name);
2630 return ret;
2631 }
2632
2633 return 0;
2634}
2635
2636static void remove_event_from_tracers(struct trace_event_call *call)
2637{
2638 struct trace_event_file *file;
2639 struct trace_array *tr;
2640
2641 do_for_each_event_file_safe(tr, file) {
2642 if (file->event_call != call)
2643 continue;
2644
2645 remove_event_file_dir(file);
2646 /*
2647 * The do_for_each_event_file_safe() is
2648 * a double loop. After finding the call for this
2649 * trace_array, we use break to jump to the next
2650 * trace_array.
2651 */
2652 break;
2653 } while_for_each_event_file();
2654}
2655
2656static void event_remove(struct trace_event_call *call)
2657{
2658 struct trace_array *tr;
2659 struct trace_event_file *file;
2660
2661 do_for_each_event_file(tr, file) {
2662 if (file->event_call != call)
2663 continue;
2664
2665 if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
2666 tr->clear_trace = true;
2667
2668 ftrace_event_enable_disable(file, 0);
2669 /*
2670 * The do_for_each_event_file() is
2671 * a double loop. After finding the call for this
2672 * trace_array, we use break to jump to the next
2673 * trace_array.
2674 */
2675 break;
2676 } while_for_each_event_file();
2677
2678 if (call->event.funcs)
2679 __unregister_trace_event(&call->event);
2680 remove_event_from_tracers(call);
2681 list_del(&call->list);
2682}
2683
2684static int event_init(struct trace_event_call *call)
2685{
2686 int ret = 0;
2687 const char *name;
2688
2689 name = trace_event_name(call);
2690 if (WARN_ON(!name))
2691 return -EINVAL;
2692
2693 if (call->class->raw_init) {
2694 ret = call->class->raw_init(call);
2695 if (ret < 0 && ret != -ENOSYS)
2696 pr_warn("Could not initialize trace events/%s\n", name);
2697 }
2698
2699 return ret;
2700}
2701
2702static int
2703__register_event(struct trace_event_call *call, struct module *mod)
2704{
2705 int ret;
2706
2707 ret = event_init(call);
2708 if (ret < 0)
2709 return ret;
2710
2711 list_add(&call->list, &ftrace_events);
2712 if (call->flags & TRACE_EVENT_FL_DYNAMIC)
2713 atomic_set(&call->refcnt, 0);
2714 else
2715 call->module = mod;
2716
2717 return 0;
2718}
2719
2720static char *eval_replace(char *ptr, struct trace_eval_map *map, int len)
2721{
2722 int rlen;
2723 int elen;
2724
2725 /* Find the length of the eval value as a string */
2726 elen = snprintf(ptr, 0, "%ld", map->eval_value);
2727 /* Make sure there's enough room to replace the string with the value */
2728 if (len < elen)
2729 return NULL;
2730
2731 snprintf(ptr, elen + 1, "%ld", map->eval_value);
2732
2733 /* Get the rest of the string of ptr */
2734 rlen = strlen(ptr + len);
2735 memmove(ptr + elen, ptr + len, rlen);
2736 /* Make sure we end the new string */
2737 ptr[elen + rlen] = 0;
2738
2739 return ptr + elen;
2740}
2741
2742static void update_event_printk(struct trace_event_call *call,
2743 struct trace_eval_map *map)
2744{
2745 char *ptr;
2746 int quote = 0;
2747 int len = strlen(map->eval_string);
2748
2749 for (ptr = call->print_fmt; *ptr; ptr++) {
2750 if (*ptr == '\\') {
2751 ptr++;
2752 /* paranoid */
2753 if (!*ptr)
2754 break;
2755 continue;
2756 }
2757 if (*ptr == '"') {
2758 quote ^= 1;
2759 continue;
2760 }
2761 if (quote)
2762 continue;
2763 if (isdigit(*ptr)) {
2764 /* skip numbers */
2765 do {
2766 ptr++;
2767 /* Check for alpha chars like ULL */
2768 } while (isalnum(*ptr));
2769 if (!*ptr)
2770 break;
2771 /*
2772 * A number must have some kind of delimiter after
2773 * it, and we can ignore that too.
2774 */
2775 continue;
2776 }
2777 if (isalpha(*ptr) || *ptr == '_') {
2778 if (strncmp(map->eval_string, ptr, len) == 0 &&
2779 !isalnum(ptr[len]) && ptr[len] != '_') {
2780 ptr = eval_replace(ptr, map, len);
2781 /* enum/sizeof string smaller than value */
2782 if (WARN_ON_ONCE(!ptr))
2783 return;
2784 /*
2785 * No need to decrement here, as eval_replace()
2786 * returns the pointer to the character passed
2787 * the eval, and two evals can not be placed
2788 * back to back without something in between.
2789 * We can skip that something in between.
2790 */
2791 continue;
2792 }
2793 skip_more:
2794 do {
2795 ptr++;
2796 } while (isalnum(*ptr) || *ptr == '_');
2797 if (!*ptr)
2798 break;
2799 /*
2800 * If what comes after this variable is a '.' or
2801 * '->' then we can continue to ignore that string.
2802 */
2803 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2804 ptr += *ptr == '.' ? 1 : 2;
2805 if (!*ptr)
2806 break;
2807 goto skip_more;
2808 }
2809 /*
2810 * Once again, we can skip the delimiter that came
2811 * after the string.
2812 */
2813 continue;
2814 }
2815 }
2816}
2817
2818static void add_str_to_module(struct module *module, char *str)
2819{
2820 struct module_string *modstr;
2821
2822 modstr = kmalloc(sizeof(*modstr), GFP_KERNEL);
2823
2824 /*
2825 * If we failed to allocate memory here, then we'll just
2826 * let the str memory leak when the module is removed.
2827 * If this fails to allocate, there's worse problems than
2828 * a leaked string on module removal.
2829 */
2830 if (WARN_ON_ONCE(!modstr))
2831 return;
2832
2833 modstr->module = module;
2834 modstr->str = str;
2835
2836 list_add(&modstr->next, &module_strings);
2837}
2838
2839static void update_event_fields(struct trace_event_call *call,
2840 struct trace_eval_map *map)
2841{
2842 struct ftrace_event_field *field;
2843 struct list_head *head;
2844 char *ptr;
2845 char *str;
2846 int len = strlen(map->eval_string);
2847
2848 /* Dynamic events should never have field maps */
2849 if (WARN_ON_ONCE(call->flags & TRACE_EVENT_FL_DYNAMIC))
2850 return;
2851
2852 head = trace_get_fields(call);
2853 list_for_each_entry(field, head, link) {
2854 ptr = strchr(field->type, '[');
2855 if (!ptr)
2856 continue;
2857 ptr++;
2858
2859 if (!isalpha(*ptr) && *ptr != '_')
2860 continue;
2861
2862 if (strncmp(map->eval_string, ptr, len) != 0)
2863 continue;
2864
2865 str = kstrdup(field->type, GFP_KERNEL);
2866 if (WARN_ON_ONCE(!str))
2867 return;
2868 ptr = str + (ptr - field->type);
2869 ptr = eval_replace(ptr, map, len);
2870 /* enum/sizeof string smaller than value */
2871 if (WARN_ON_ONCE(!ptr)) {
2872 kfree(str);
2873 continue;
2874 }
2875
2876 /*
2877 * If the event is part of a module, then we need to free the string
2878 * when the module is removed. Otherwise, it will stay allocated
2879 * until a reboot.
2880 */
2881 if (call->module)
2882 add_str_to_module(call->module, str);
2883
2884 field->type = str;
2885 }
2886}
2887
2888void trace_event_eval_update(struct trace_eval_map **map, int len)
2889{
2890 struct trace_event_call *call, *p;
2891 const char *last_system = NULL;
2892 bool first = false;
2893 int last_i;
2894 int i;
2895
2896 down_write(&trace_event_sem);
2897 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2898 /* events are usually grouped together with systems */
2899 if (!last_system || call->class->system != last_system) {
2900 first = true;
2901 last_i = 0;
2902 last_system = call->class->system;
2903 }
2904
2905 /*
2906 * Since calls are grouped by systems, the likelihood that the
2907 * next call in the iteration belongs to the same system as the
2908 * previous call is high. As an optimization, we skip searching
2909 * for a map[] that matches the call's system if the last call
2910 * was from the same system. That's what last_i is for. If the
2911 * call has the same system as the previous call, then last_i
2912 * will be the index of the first map[] that has a matching
2913 * system.
2914 */
2915 for (i = last_i; i < len; i++) {
2916 if (call->class->system == map[i]->system) {
2917 /* Save the first system if need be */
2918 if (first) {
2919 last_i = i;
2920 first = false;
2921 }
2922 update_event_printk(call, map[i]);
2923 update_event_fields(call, map[i]);
2924 }
2925 }
2926 cond_resched();
2927 }
2928 up_write(&trace_event_sem);
2929}
2930
2931static bool event_in_systems(struct trace_event_call *call,
2932 const char *systems)
2933{
2934 const char *system;
2935 const char *p;
2936
2937 if (!systems)
2938 return true;
2939
2940 system = call->class->system;
2941 p = strstr(systems, system);
2942 if (!p)
2943 return false;
2944
2945 if (p != systems && !isspace(*(p - 1)) && *(p - 1) != ',')
2946 return false;
2947
2948 p += strlen(system);
2949 return !*p || isspace(*p) || *p == ',';
2950}
2951
2952static struct trace_event_file *
2953trace_create_new_event(struct trace_event_call *call,
2954 struct trace_array *tr)
2955{
2956 struct trace_pid_list *no_pid_list;
2957 struct trace_pid_list *pid_list;
2958 struct trace_event_file *file;
2959 unsigned int first;
2960
2961 if (!event_in_systems(call, tr->system_names))
2962 return NULL;
2963
2964 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2965 if (!file)
2966 return ERR_PTR(-ENOMEM);
2967
2968 pid_list = rcu_dereference_protected(tr->filtered_pids,
2969 lockdep_is_held(&event_mutex));
2970 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
2971 lockdep_is_held(&event_mutex));
2972
2973 if (!trace_pid_list_first(pid_list, &first) ||
2974 !trace_pid_list_first(no_pid_list, &first))
2975 file->flags |= EVENT_FILE_FL_PID_FILTER;
2976
2977 file->event_call = call;
2978 file->tr = tr;
2979 atomic_set(&file->sm_ref, 0);
2980 atomic_set(&file->tm_ref, 0);
2981 INIT_LIST_HEAD(&file->triggers);
2982 list_add(&file->list, &tr->events);
2983 event_file_get(file);
2984
2985 return file;
2986}
2987
2988#define MAX_BOOT_TRIGGERS 32
2989
2990static struct boot_triggers {
2991 const char *event;
2992 char *trigger;
2993} bootup_triggers[MAX_BOOT_TRIGGERS];
2994
2995static char bootup_trigger_buf[COMMAND_LINE_SIZE];
2996static int nr_boot_triggers;
2997
2998static __init int setup_trace_triggers(char *str)
2999{
3000 char *trigger;
3001 char *buf;
3002 int i;
3003
3004 strscpy(bootup_trigger_buf, str, COMMAND_LINE_SIZE);
3005 trace_set_ring_buffer_expanded(NULL);
3006 disable_tracing_selftest("running event triggers");
3007
3008 buf = bootup_trigger_buf;
3009 for (i = 0; i < MAX_BOOT_TRIGGERS; i++) {
3010 trigger = strsep(&buf, ",");
3011 if (!trigger)
3012 break;
3013 bootup_triggers[i].event = strsep(&trigger, ".");
3014 bootup_triggers[i].trigger = trigger;
3015 if (!bootup_triggers[i].trigger)
3016 break;
3017 }
3018
3019 nr_boot_triggers = i;
3020 return 1;
3021}
3022__setup("trace_trigger=", setup_trace_triggers);
3023
3024/* Add an event to a trace directory */
3025static int
3026__trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
3027{
3028 struct trace_event_file *file;
3029
3030 file = trace_create_new_event(call, tr);
3031 /*
3032 * trace_create_new_event() returns ERR_PTR(-ENOMEM) if failed
3033 * allocation, or NULL if the event is not part of the tr->system_names.
3034 * When the event is not part of the tr->system_names, return zero, not
3035 * an error.
3036 */
3037 if (!file)
3038 return 0;
3039
3040 if (IS_ERR(file))
3041 return PTR_ERR(file);
3042
3043 if (eventdir_initialized)
3044 return event_create_dir(tr->event_dir, file);
3045 else
3046 return event_define_fields(call);
3047}
3048
3049static void trace_early_triggers(struct trace_event_file *file, const char *name)
3050{
3051 int ret;
3052 int i;
3053
3054 for (i = 0; i < nr_boot_triggers; i++) {
3055 if (strcmp(name, bootup_triggers[i].event))
3056 continue;
3057 mutex_lock(&event_mutex);
3058 ret = trigger_process_regex(file, bootup_triggers[i].trigger);
3059 mutex_unlock(&event_mutex);
3060 if (ret)
3061 pr_err("Failed to register trigger '%s' on event %s\n",
3062 bootup_triggers[i].trigger,
3063 bootup_triggers[i].event);
3064 }
3065}
3066
3067/*
3068 * Just create a descriptor for early init. A descriptor is required
3069 * for enabling events at boot. We want to enable events before
3070 * the filesystem is initialized.
3071 */
3072static int
3073__trace_early_add_new_event(struct trace_event_call *call,
3074 struct trace_array *tr)
3075{
3076 struct trace_event_file *file;
3077 int ret;
3078
3079 file = trace_create_new_event(call, tr);
3080 /*
3081 * trace_create_new_event() returns ERR_PTR(-ENOMEM) if failed
3082 * allocation, or NULL if the event is not part of the tr->system_names.
3083 * When the event is not part of the tr->system_names, return zero, not
3084 * an error.
3085 */
3086 if (!file)
3087 return 0;
3088
3089 if (IS_ERR(file))
3090 return PTR_ERR(file);
3091
3092 ret = event_define_fields(call);
3093 if (ret)
3094 return ret;
3095
3096 trace_early_triggers(file, trace_event_name(call));
3097
3098 return 0;
3099}
3100
3101struct ftrace_module_file_ops;
3102static void __add_event_to_tracers(struct trace_event_call *call);
3103
3104/* Add an additional event_call dynamically */
3105int trace_add_event_call(struct trace_event_call *call)
3106{
3107 int ret;
3108 lockdep_assert_held(&event_mutex);
3109
3110 mutex_lock(&trace_types_lock);
3111
3112 ret = __register_event(call, NULL);
3113 if (ret >= 0)
3114 __add_event_to_tracers(call);
3115
3116 mutex_unlock(&trace_types_lock);
3117 return ret;
3118}
3119EXPORT_SYMBOL_GPL(trace_add_event_call);
3120
3121/*
3122 * Must be called under locking of trace_types_lock, event_mutex and
3123 * trace_event_sem.
3124 */
3125static void __trace_remove_event_call(struct trace_event_call *call)
3126{
3127 event_remove(call);
3128 trace_destroy_fields(call);
3129 free_event_filter(call->filter);
3130 call->filter = NULL;
3131}
3132
3133static int probe_remove_event_call(struct trace_event_call *call)
3134{
3135 struct trace_array *tr;
3136 struct trace_event_file *file;
3137
3138#ifdef CONFIG_PERF_EVENTS
3139 if (call->perf_refcount)
3140 return -EBUSY;
3141#endif
3142 do_for_each_event_file(tr, file) {
3143 if (file->event_call != call)
3144 continue;
3145 /*
3146 * We can't rely on ftrace_event_enable_disable(enable => 0)
3147 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
3148 * TRACE_REG_UNREGISTER.
3149 */
3150 if (file->flags & EVENT_FILE_FL_ENABLED)
3151 goto busy;
3152
3153 if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
3154 tr->clear_trace = true;
3155 /*
3156 * The do_for_each_event_file_safe() is
3157 * a double loop. After finding the call for this
3158 * trace_array, we use break to jump to the next
3159 * trace_array.
3160 */
3161 break;
3162 } while_for_each_event_file();
3163
3164 __trace_remove_event_call(call);
3165
3166 return 0;
3167 busy:
3168 /* No need to clear the trace now */
3169 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
3170 tr->clear_trace = false;
3171 }
3172 return -EBUSY;
3173}
3174
3175/* Remove an event_call */
3176int trace_remove_event_call(struct trace_event_call *call)
3177{
3178 int ret;
3179
3180 lockdep_assert_held(&event_mutex);
3181
3182 mutex_lock(&trace_types_lock);
3183 down_write(&trace_event_sem);
3184 ret = probe_remove_event_call(call);
3185 up_write(&trace_event_sem);
3186 mutex_unlock(&trace_types_lock);
3187
3188 return ret;
3189}
3190EXPORT_SYMBOL_GPL(trace_remove_event_call);
3191
3192#define for_each_event(event, start, end) \
3193 for (event = start; \
3194 (unsigned long)event < (unsigned long)end; \
3195 event++)
3196
3197#ifdef CONFIG_MODULES
3198
3199static void trace_module_add_events(struct module *mod)
3200{
3201 struct trace_event_call **call, **start, **end;
3202
3203 if (!mod->num_trace_events)
3204 return;
3205
3206 /* Don't add infrastructure for mods without tracepoints */
3207 if (trace_module_has_bad_taint(mod)) {
3208 pr_err("%s: module has bad taint, not creating trace events\n",
3209 mod->name);
3210 return;
3211 }
3212
3213 start = mod->trace_events;
3214 end = mod->trace_events + mod->num_trace_events;
3215
3216 for_each_event(call, start, end) {
3217 __register_event(*call, mod);
3218 __add_event_to_tracers(*call);
3219 }
3220}
3221
3222static void trace_module_remove_events(struct module *mod)
3223{
3224 struct trace_event_call *call, *p;
3225 struct module_string *modstr, *m;
3226
3227 down_write(&trace_event_sem);
3228 list_for_each_entry_safe(call, p, &ftrace_events, list) {
3229 if ((call->flags & TRACE_EVENT_FL_DYNAMIC) || !call->module)
3230 continue;
3231 if (call->module == mod)
3232 __trace_remove_event_call(call);
3233 }
3234 /* Check for any strings allocade for this module */
3235 list_for_each_entry_safe(modstr, m, &module_strings, next) {
3236 if (modstr->module != mod)
3237 continue;
3238 list_del(&modstr->next);
3239 kfree(modstr->str);
3240 kfree(modstr);
3241 }
3242 up_write(&trace_event_sem);
3243
3244 /*
3245 * It is safest to reset the ring buffer if the module being unloaded
3246 * registered any events that were used. The only worry is if
3247 * a new module gets loaded, and takes on the same id as the events
3248 * of this module. When printing out the buffer, traced events left
3249 * over from this module may be passed to the new module events and
3250 * unexpected results may occur.
3251 */
3252 tracing_reset_all_online_cpus_unlocked();
3253}
3254
3255static int trace_module_notify(struct notifier_block *self,
3256 unsigned long val, void *data)
3257{
3258 struct module *mod = data;
3259
3260 mutex_lock(&event_mutex);
3261 mutex_lock(&trace_types_lock);
3262 switch (val) {
3263 case MODULE_STATE_COMING:
3264 trace_module_add_events(mod);
3265 break;
3266 case MODULE_STATE_GOING:
3267 trace_module_remove_events(mod);
3268 break;
3269 }
3270 mutex_unlock(&trace_types_lock);
3271 mutex_unlock(&event_mutex);
3272
3273 return NOTIFY_OK;
3274}
3275
3276static struct notifier_block trace_module_nb = {
3277 .notifier_call = trace_module_notify,
3278 .priority = 1, /* higher than trace.c module notify */
3279};
3280#endif /* CONFIG_MODULES */
3281
3282/* Create a new event directory structure for a trace directory. */
3283static void
3284__trace_add_event_dirs(struct trace_array *tr)
3285{
3286 struct trace_event_call *call;
3287 int ret;
3288
3289 list_for_each_entry(call, &ftrace_events, list) {
3290 ret = __trace_add_new_event(call, tr);
3291 if (ret < 0)
3292 pr_warn("Could not create directory for event %s\n",
3293 trace_event_name(call));
3294 }
3295}
3296
3297/* Returns any file that matches the system and event */
3298struct trace_event_file *
3299__find_event_file(struct trace_array *tr, const char *system, const char *event)
3300{
3301 struct trace_event_file *file;
3302 struct trace_event_call *call;
3303 const char *name;
3304
3305 list_for_each_entry(file, &tr->events, list) {
3306
3307 call = file->event_call;
3308 name = trace_event_name(call);
3309
3310 if (!name || !call->class)
3311 continue;
3312
3313 if (strcmp(event, name) == 0 &&
3314 strcmp(system, call->class->system) == 0)
3315 return file;
3316 }
3317 return NULL;
3318}
3319
3320/* Returns valid trace event files that match system and event */
3321struct trace_event_file *
3322find_event_file(struct trace_array *tr, const char *system, const char *event)
3323{
3324 struct trace_event_file *file;
3325
3326 file = __find_event_file(tr, system, event);
3327 if (!file || !file->event_call->class->reg ||
3328 file->event_call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
3329 return NULL;
3330
3331 return file;
3332}
3333
3334/**
3335 * trace_get_event_file - Find and return a trace event file
3336 * @instance: The name of the trace instance containing the event
3337 * @system: The name of the system containing the event
3338 * @event: The name of the event
3339 *
3340 * Return a trace event file given the trace instance name, trace
3341 * system, and trace event name. If the instance name is NULL, it
3342 * refers to the top-level trace array.
3343 *
3344 * This function will look it up and return it if found, after calling
3345 * trace_array_get() to prevent the instance from going away, and
3346 * increment the event's module refcount to prevent it from being
3347 * removed.
3348 *
3349 * To release the file, call trace_put_event_file(), which will call
3350 * trace_array_put() and decrement the event's module refcount.
3351 *
3352 * Return: The trace event on success, ERR_PTR otherwise.
3353 */
3354struct trace_event_file *trace_get_event_file(const char *instance,
3355 const char *system,
3356 const char *event)
3357{
3358 struct trace_array *tr = top_trace_array();
3359 struct trace_event_file *file = NULL;
3360 int ret = -EINVAL;
3361
3362 if (instance) {
3363 tr = trace_array_find_get(instance);
3364 if (!tr)
3365 return ERR_PTR(-ENOENT);
3366 } else {
3367 ret = trace_array_get(tr);
3368 if (ret)
3369 return ERR_PTR(ret);
3370 }
3371
3372 mutex_lock(&event_mutex);
3373
3374 file = find_event_file(tr, system, event);
3375 if (!file) {
3376 trace_array_put(tr);
3377 ret = -EINVAL;
3378 goto out;
3379 }
3380
3381 /* Don't let event modules unload while in use */
3382 ret = trace_event_try_get_ref(file->event_call);
3383 if (!ret) {
3384 trace_array_put(tr);
3385 ret = -EBUSY;
3386 goto out;
3387 }
3388
3389 ret = 0;
3390 out:
3391 mutex_unlock(&event_mutex);
3392
3393 if (ret)
3394 file = ERR_PTR(ret);
3395
3396 return file;
3397}
3398EXPORT_SYMBOL_GPL(trace_get_event_file);
3399
3400/**
3401 * trace_put_event_file - Release a file from trace_get_event_file()
3402 * @file: The trace event file
3403 *
3404 * If a file was retrieved using trace_get_event_file(), this should
3405 * be called when it's no longer needed. It will cancel the previous
3406 * trace_array_get() called by that function, and decrement the
3407 * event's module refcount.
3408 */
3409void trace_put_event_file(struct trace_event_file *file)
3410{
3411 mutex_lock(&event_mutex);
3412 trace_event_put_ref(file->event_call);
3413 mutex_unlock(&event_mutex);
3414
3415 trace_array_put(file->tr);
3416}
3417EXPORT_SYMBOL_GPL(trace_put_event_file);
3418
3419#ifdef CONFIG_DYNAMIC_FTRACE
3420
3421/* Avoid typos */
3422#define ENABLE_EVENT_STR "enable_event"
3423#define DISABLE_EVENT_STR "disable_event"
3424
3425struct event_probe_data {
3426 struct trace_event_file *file;
3427 unsigned long count;
3428 int ref;
3429 bool enable;
3430};
3431
3432static void update_event_probe(struct event_probe_data *data)
3433{
3434 if (data->enable)
3435 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
3436 else
3437 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
3438}
3439
3440static void
3441event_enable_probe(unsigned long ip, unsigned long parent_ip,
3442 struct trace_array *tr, struct ftrace_probe_ops *ops,
3443 void *data)
3444{
3445 struct ftrace_func_mapper *mapper = data;
3446 struct event_probe_data *edata;
3447 void **pdata;
3448
3449 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3450 if (!pdata || !*pdata)
3451 return;
3452
3453 edata = *pdata;
3454 update_event_probe(edata);
3455}
3456
3457static void
3458event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
3459 struct trace_array *tr, struct ftrace_probe_ops *ops,
3460 void *data)
3461{
3462 struct ftrace_func_mapper *mapper = data;
3463 struct event_probe_data *edata;
3464 void **pdata;
3465
3466 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3467 if (!pdata || !*pdata)
3468 return;
3469
3470 edata = *pdata;
3471
3472 if (!edata->count)
3473 return;
3474
3475 /* Skip if the event is in a state we want to switch to */
3476 if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
3477 return;
3478
3479 if (edata->count != -1)
3480 (edata->count)--;
3481
3482 update_event_probe(edata);
3483}
3484
3485static int
3486event_enable_print(struct seq_file *m, unsigned long ip,
3487 struct ftrace_probe_ops *ops, void *data)
3488{
3489 struct ftrace_func_mapper *mapper = data;
3490 struct event_probe_data *edata;
3491 void **pdata;
3492
3493 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3494
3495 if (WARN_ON_ONCE(!pdata || !*pdata))
3496 return 0;
3497
3498 edata = *pdata;
3499
3500 seq_printf(m, "%ps:", (void *)ip);
3501
3502 seq_printf(m, "%s:%s:%s",
3503 edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
3504 edata->file->event_call->class->system,
3505 trace_event_name(edata->file->event_call));
3506
3507 if (edata->count == -1)
3508 seq_puts(m, ":unlimited\n");
3509 else
3510 seq_printf(m, ":count=%ld\n", edata->count);
3511
3512 return 0;
3513}
3514
3515static int
3516event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
3517 unsigned long ip, void *init_data, void **data)
3518{
3519 struct ftrace_func_mapper *mapper = *data;
3520 struct event_probe_data *edata = init_data;
3521 int ret;
3522
3523 if (!mapper) {
3524 mapper = allocate_ftrace_func_mapper();
3525 if (!mapper)
3526 return -ENODEV;
3527 *data = mapper;
3528 }
3529
3530 ret = ftrace_func_mapper_add_ip(mapper, ip, edata);
3531 if (ret < 0)
3532 return ret;
3533
3534 edata->ref++;
3535
3536 return 0;
3537}
3538
3539static int free_probe_data(void *data)
3540{
3541 struct event_probe_data *edata = data;
3542
3543 edata->ref--;
3544 if (!edata->ref) {
3545 /* Remove the SOFT_MODE flag */
3546 __ftrace_event_enable_disable(edata->file, 0, 1);
3547 trace_event_put_ref(edata->file->event_call);
3548 kfree(edata);
3549 }
3550 return 0;
3551}
3552
3553static void
3554event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
3555 unsigned long ip, void *data)
3556{
3557 struct ftrace_func_mapper *mapper = data;
3558 struct event_probe_data *edata;
3559
3560 if (!ip) {
3561 if (!mapper)
3562 return;
3563 free_ftrace_func_mapper(mapper, free_probe_data);
3564 return;
3565 }
3566
3567 edata = ftrace_func_mapper_remove_ip(mapper, ip);
3568
3569 if (WARN_ON_ONCE(!edata))
3570 return;
3571
3572 if (WARN_ON_ONCE(edata->ref <= 0))
3573 return;
3574
3575 free_probe_data(edata);
3576}
3577
3578static struct ftrace_probe_ops event_enable_probe_ops = {
3579 .func = event_enable_probe,
3580 .print = event_enable_print,
3581 .init = event_enable_init,
3582 .free = event_enable_free,
3583};
3584
3585static struct ftrace_probe_ops event_enable_count_probe_ops = {
3586 .func = event_enable_count_probe,
3587 .print = event_enable_print,
3588 .init = event_enable_init,
3589 .free = event_enable_free,
3590};
3591
3592static struct ftrace_probe_ops event_disable_probe_ops = {
3593 .func = event_enable_probe,
3594 .print = event_enable_print,
3595 .init = event_enable_init,
3596 .free = event_enable_free,
3597};
3598
3599static struct ftrace_probe_ops event_disable_count_probe_ops = {
3600 .func = event_enable_count_probe,
3601 .print = event_enable_print,
3602 .init = event_enable_init,
3603 .free = event_enable_free,
3604};
3605
3606static int
3607event_enable_func(struct trace_array *tr, struct ftrace_hash *hash,
3608 char *glob, char *cmd, char *param, int enabled)
3609{
3610 struct trace_event_file *file;
3611 struct ftrace_probe_ops *ops;
3612 struct event_probe_data *data;
3613 const char *system;
3614 const char *event;
3615 char *number;
3616 bool enable;
3617 int ret;
3618
3619 if (!tr)
3620 return -ENODEV;
3621
3622 /* hash funcs only work with set_ftrace_filter */
3623 if (!enabled || !param)
3624 return -EINVAL;
3625
3626 system = strsep(¶m, ":");
3627 if (!param)
3628 return -EINVAL;
3629
3630 event = strsep(¶m, ":");
3631
3632 mutex_lock(&event_mutex);
3633
3634 ret = -EINVAL;
3635 file = find_event_file(tr, system, event);
3636 if (!file)
3637 goto out;
3638
3639 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
3640
3641 if (enable)
3642 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
3643 else
3644 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
3645
3646 if (glob[0] == '!') {
3647 ret = unregister_ftrace_function_probe_func(glob+1, tr, ops);
3648 goto out;
3649 }
3650
3651 ret = -ENOMEM;
3652
3653 data = kzalloc(sizeof(*data), GFP_KERNEL);
3654 if (!data)
3655 goto out;
3656
3657 data->enable = enable;
3658 data->count = -1;
3659 data->file = file;
3660
3661 if (!param)
3662 goto out_reg;
3663
3664 number = strsep(¶m, ":");
3665
3666 ret = -EINVAL;
3667 if (!strlen(number))
3668 goto out_free;
3669
3670 /*
3671 * We use the callback data field (which is a pointer)
3672 * as our counter.
3673 */
3674 ret = kstrtoul(number, 0, &data->count);
3675 if (ret)
3676 goto out_free;
3677
3678 out_reg:
3679 /* Don't let event modules unload while probe registered */
3680 ret = trace_event_try_get_ref(file->event_call);
3681 if (!ret) {
3682 ret = -EBUSY;
3683 goto out_free;
3684 }
3685
3686 ret = __ftrace_event_enable_disable(file, 1, 1);
3687 if (ret < 0)
3688 goto out_put;
3689
3690 ret = register_ftrace_function_probe(glob, tr, ops, data);
3691 /*
3692 * The above returns on success the # of functions enabled,
3693 * but if it didn't find any functions it returns zero.
3694 * Consider no functions a failure too.
3695 */
3696 if (!ret) {
3697 ret = -ENOENT;
3698 goto out_disable;
3699 } else if (ret < 0)
3700 goto out_disable;
3701 /* Just return zero, not the number of enabled functions */
3702 ret = 0;
3703 out:
3704 mutex_unlock(&event_mutex);
3705 return ret;
3706
3707 out_disable:
3708 __ftrace_event_enable_disable(file, 0, 1);
3709 out_put:
3710 trace_event_put_ref(file->event_call);
3711 out_free:
3712 kfree(data);
3713 goto out;
3714}
3715
3716static struct ftrace_func_command event_enable_cmd = {
3717 .name = ENABLE_EVENT_STR,
3718 .func = event_enable_func,
3719};
3720
3721static struct ftrace_func_command event_disable_cmd = {
3722 .name = DISABLE_EVENT_STR,
3723 .func = event_enable_func,
3724};
3725
3726static __init int register_event_cmds(void)
3727{
3728 int ret;
3729
3730 ret = register_ftrace_command(&event_enable_cmd);
3731 if (WARN_ON(ret < 0))
3732 return ret;
3733 ret = register_ftrace_command(&event_disable_cmd);
3734 if (WARN_ON(ret < 0))
3735 unregister_ftrace_command(&event_enable_cmd);
3736 return ret;
3737}
3738#else
3739static inline int register_event_cmds(void) { return 0; }
3740#endif /* CONFIG_DYNAMIC_FTRACE */
3741
3742/*
3743 * The top level array and trace arrays created by boot-time tracing
3744 * have already had its trace_event_file descriptors created in order
3745 * to allow for early events to be recorded.
3746 * This function is called after the tracefs has been initialized,
3747 * and we now have to create the files associated to the events.
3748 */
3749static void __trace_early_add_event_dirs(struct trace_array *tr)
3750{
3751 struct trace_event_file *file;
3752 int ret;
3753
3754
3755 list_for_each_entry(file, &tr->events, list) {
3756 ret = event_create_dir(tr->event_dir, file);
3757 if (ret < 0)
3758 pr_warn("Could not create directory for event %s\n",
3759 trace_event_name(file->event_call));
3760 }
3761}
3762
3763/*
3764 * For early boot up, the top trace array and the trace arrays created
3765 * by boot-time tracing require to have a list of events that can be
3766 * enabled. This must be done before the filesystem is set up in order
3767 * to allow events to be traced early.
3768 */
3769void __trace_early_add_events(struct trace_array *tr)
3770{
3771 struct trace_event_call *call;
3772 int ret;
3773
3774 list_for_each_entry(call, &ftrace_events, list) {
3775 /* Early boot up should not have any modules loaded */
3776 if (!(call->flags & TRACE_EVENT_FL_DYNAMIC) &&
3777 WARN_ON_ONCE(call->module))
3778 continue;
3779
3780 ret = __trace_early_add_new_event(call, tr);
3781 if (ret < 0)
3782 pr_warn("Could not create early event %s\n",
3783 trace_event_name(call));
3784 }
3785}
3786
3787/* Remove the event directory structure for a trace directory. */
3788static void
3789__trace_remove_event_dirs(struct trace_array *tr)
3790{
3791 struct trace_event_file *file, *next;
3792
3793 list_for_each_entry_safe(file, next, &tr->events, list)
3794 remove_event_file_dir(file);
3795}
3796
3797static void __add_event_to_tracers(struct trace_event_call *call)
3798{
3799 struct trace_array *tr;
3800
3801 list_for_each_entry(tr, &ftrace_trace_arrays, list)
3802 __trace_add_new_event(call, tr);
3803}
3804
3805extern struct trace_event_call *__start_ftrace_events[];
3806extern struct trace_event_call *__stop_ftrace_events[];
3807
3808static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
3809
3810static __init int setup_trace_event(char *str)
3811{
3812 strscpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
3813 trace_set_ring_buffer_expanded(NULL);
3814 disable_tracing_selftest("running event tracing");
3815
3816 return 1;
3817}
3818__setup("trace_event=", setup_trace_event);
3819
3820static int events_callback(const char *name, umode_t *mode, void **data,
3821 const struct file_operations **fops)
3822{
3823 if (strcmp(name, "enable") == 0) {
3824 *mode = TRACE_MODE_WRITE;
3825 *fops = &ftrace_tr_enable_fops;
3826 return 1;
3827 }
3828
3829 if (strcmp(name, "header_page") == 0) {
3830 *mode = TRACE_MODE_READ;
3831 *fops = &ftrace_show_header_page_fops;
3832
3833 } else if (strcmp(name, "header_event") == 0) {
3834 *mode = TRACE_MODE_READ;
3835 *fops = &ftrace_show_header_event_fops;
3836 } else
3837 return 0;
3838
3839 return 1;
3840}
3841
3842/* Expects to have event_mutex held when called */
3843static int
3844create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
3845{
3846 struct eventfs_inode *e_events;
3847 struct dentry *entry;
3848 int nr_entries;
3849 static struct eventfs_entry events_entries[] = {
3850 {
3851 .name = "enable",
3852 .callback = events_callback,
3853 },
3854 {
3855 .name = "header_page",
3856 .callback = events_callback,
3857 },
3858 {
3859 .name = "header_event",
3860 .callback = events_callback,
3861 },
3862 };
3863
3864 entry = trace_create_file("set_event", TRACE_MODE_WRITE, parent,
3865 tr, &ftrace_set_event_fops);
3866 if (!entry)
3867 return -ENOMEM;
3868
3869 nr_entries = ARRAY_SIZE(events_entries);
3870
3871 e_events = eventfs_create_events_dir("events", parent, events_entries,
3872 nr_entries, tr);
3873 if (IS_ERR(e_events)) {
3874 pr_warn("Could not create tracefs 'events' directory\n");
3875 return -ENOMEM;
3876 }
3877
3878 /* There are not as crucial, just warn if they are not created */
3879
3880 trace_create_file("set_event_pid", TRACE_MODE_WRITE, parent,
3881 tr, &ftrace_set_event_pid_fops);
3882
3883 trace_create_file("set_event_notrace_pid",
3884 TRACE_MODE_WRITE, parent, tr,
3885 &ftrace_set_event_notrace_pid_fops);
3886
3887 tr->event_dir = e_events;
3888
3889 return 0;
3890}
3891
3892/**
3893 * event_trace_add_tracer - add a instance of a trace_array to events
3894 * @parent: The parent dentry to place the files/directories for events in
3895 * @tr: The trace array associated with these events
3896 *
3897 * When a new instance is created, it needs to set up its events
3898 * directory, as well as other files associated with events. It also
3899 * creates the event hierarchy in the @parent/events directory.
3900 *
3901 * Returns 0 on success.
3902 *
3903 * Must be called with event_mutex held.
3904 */
3905int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
3906{
3907 int ret;
3908
3909 lockdep_assert_held(&event_mutex);
3910
3911 ret = create_event_toplevel_files(parent, tr);
3912 if (ret)
3913 goto out;
3914
3915 down_write(&trace_event_sem);
3916 /* If tr already has the event list, it is initialized in early boot. */
3917 if (unlikely(!list_empty(&tr->events)))
3918 __trace_early_add_event_dirs(tr);
3919 else
3920 __trace_add_event_dirs(tr);
3921 up_write(&trace_event_sem);
3922
3923 out:
3924 return ret;
3925}
3926
3927/*
3928 * The top trace array already had its file descriptors created.
3929 * Now the files themselves need to be created.
3930 */
3931static __init int
3932early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
3933{
3934 int ret;
3935
3936 mutex_lock(&event_mutex);
3937
3938 ret = create_event_toplevel_files(parent, tr);
3939 if (ret)
3940 goto out_unlock;
3941
3942 down_write(&trace_event_sem);
3943 __trace_early_add_event_dirs(tr);
3944 up_write(&trace_event_sem);
3945
3946 out_unlock:
3947 mutex_unlock(&event_mutex);
3948
3949 return ret;
3950}
3951
3952/* Must be called with event_mutex held */
3953int event_trace_del_tracer(struct trace_array *tr)
3954{
3955 lockdep_assert_held(&event_mutex);
3956
3957 /* Disable any event triggers and associated soft-disabled events */
3958 clear_event_triggers(tr);
3959
3960 /* Clear the pid list */
3961 __ftrace_clear_event_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
3962
3963 /* Disable any running events */
3964 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3965
3966 /* Make sure no more events are being executed */
3967 tracepoint_synchronize_unregister();
3968
3969 down_write(&trace_event_sem);
3970 __trace_remove_event_dirs(tr);
3971 eventfs_remove_events_dir(tr->event_dir);
3972 up_write(&trace_event_sem);
3973
3974 tr->event_dir = NULL;
3975
3976 return 0;
3977}
3978
3979static __init int event_trace_memsetup(void)
3980{
3981 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3982 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3983 return 0;
3984}
3985
3986__init void
3987early_enable_events(struct trace_array *tr, char *buf, bool disable_first)
3988{
3989 char *token;
3990 int ret;
3991
3992 while (true) {
3993 token = strsep(&buf, ",");
3994
3995 if (!token)
3996 break;
3997
3998 if (*token) {
3999 /* Restarting syscalls requires that we stop them first */
4000 if (disable_first)
4001 ftrace_set_clr_event(tr, token, 0);
4002
4003 ret = ftrace_set_clr_event(tr, token, 1);
4004 if (ret)
4005 pr_warn("Failed to enable trace event: %s\n", token);
4006 }
4007
4008 /* Put back the comma to allow this to be called again */
4009 if (buf)
4010 *(buf - 1) = ',';
4011 }
4012}
4013
4014static __init int event_trace_enable(void)
4015{
4016 struct trace_array *tr = top_trace_array();
4017 struct trace_event_call **iter, *call;
4018 int ret;
4019
4020 if (!tr)
4021 return -ENODEV;
4022
4023 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
4024
4025 call = *iter;
4026 ret = event_init(call);
4027 if (!ret)
4028 list_add(&call->list, &ftrace_events);
4029 }
4030
4031 register_trigger_cmds();
4032
4033 /*
4034 * We need the top trace array to have a working set of trace
4035 * points at early init, before the debug files and directories
4036 * are created. Create the file entries now, and attach them
4037 * to the actual file dentries later.
4038 */
4039 __trace_early_add_events(tr);
4040
4041 early_enable_events(tr, bootup_event_buf, false);
4042
4043 trace_printk_start_comm();
4044
4045 register_event_cmds();
4046
4047
4048 return 0;
4049}
4050
4051/*
4052 * event_trace_enable() is called from trace_event_init() first to
4053 * initialize events and perhaps start any events that are on the
4054 * command line. Unfortunately, there are some events that will not
4055 * start this early, like the system call tracepoints that need
4056 * to set the %SYSCALL_WORK_SYSCALL_TRACEPOINT flag of pid 1. But
4057 * event_trace_enable() is called before pid 1 starts, and this flag
4058 * is never set, making the syscall tracepoint never get reached, but
4059 * the event is enabled regardless (and not doing anything).
4060 */
4061static __init int event_trace_enable_again(void)
4062{
4063 struct trace_array *tr;
4064
4065 tr = top_trace_array();
4066 if (!tr)
4067 return -ENODEV;
4068
4069 early_enable_events(tr, bootup_event_buf, true);
4070
4071 return 0;
4072}
4073
4074early_initcall(event_trace_enable_again);
4075
4076/* Init fields which doesn't related to the tracefs */
4077static __init int event_trace_init_fields(void)
4078{
4079 if (trace_define_generic_fields())
4080 pr_warn("tracing: Failed to allocated generic fields");
4081
4082 if (trace_define_common_fields())
4083 pr_warn("tracing: Failed to allocate common fields");
4084
4085 return 0;
4086}
4087
4088__init int event_trace_init(void)
4089{
4090 struct trace_array *tr;
4091 int ret;
4092
4093 tr = top_trace_array();
4094 if (!tr)
4095 return -ENODEV;
4096
4097 trace_create_file("available_events", TRACE_MODE_READ,
4098 NULL, tr, &ftrace_avail_fops);
4099
4100 ret = early_event_add_tracer(NULL, tr);
4101 if (ret)
4102 return ret;
4103
4104#ifdef CONFIG_MODULES
4105 ret = register_module_notifier(&trace_module_nb);
4106 if (ret)
4107 pr_warn("Failed to register trace events module notifier\n");
4108#endif
4109
4110 eventdir_initialized = true;
4111
4112 return 0;
4113}
4114
4115void __init trace_event_init(void)
4116{
4117 event_trace_memsetup();
4118 init_ftrace_syscalls();
4119 event_trace_enable();
4120 event_trace_init_fields();
4121}
4122
4123#ifdef CONFIG_EVENT_TRACE_STARTUP_TEST
4124
4125static DEFINE_SPINLOCK(test_spinlock);
4126static DEFINE_SPINLOCK(test_spinlock_irq);
4127static DEFINE_MUTEX(test_mutex);
4128
4129static __init void test_work(struct work_struct *dummy)
4130{
4131 spin_lock(&test_spinlock);
4132 spin_lock_irq(&test_spinlock_irq);
4133 udelay(1);
4134 spin_unlock_irq(&test_spinlock_irq);
4135 spin_unlock(&test_spinlock);
4136
4137 mutex_lock(&test_mutex);
4138 msleep(1);
4139 mutex_unlock(&test_mutex);
4140}
4141
4142static __init int event_test_thread(void *unused)
4143{
4144 void *test_malloc;
4145
4146 test_malloc = kmalloc(1234, GFP_KERNEL);
4147 if (!test_malloc)
4148 pr_info("failed to kmalloc\n");
4149
4150 schedule_on_each_cpu(test_work);
4151
4152 kfree(test_malloc);
4153
4154 set_current_state(TASK_INTERRUPTIBLE);
4155 while (!kthread_should_stop()) {
4156 schedule();
4157 set_current_state(TASK_INTERRUPTIBLE);
4158 }
4159 __set_current_state(TASK_RUNNING);
4160
4161 return 0;
4162}
4163
4164/*
4165 * Do various things that may trigger events.
4166 */
4167static __init void event_test_stuff(void)
4168{
4169 struct task_struct *test_thread;
4170
4171 test_thread = kthread_run(event_test_thread, NULL, "test-events");
4172 msleep(1);
4173 kthread_stop(test_thread);
4174}
4175
4176/*
4177 * For every trace event defined, we will test each trace point separately,
4178 * and then by groups, and finally all trace points.
4179 */
4180static __init void event_trace_self_tests(void)
4181{
4182 struct trace_subsystem_dir *dir;
4183 struct trace_event_file *file;
4184 struct trace_event_call *call;
4185 struct event_subsystem *system;
4186 struct trace_array *tr;
4187 int ret;
4188
4189 tr = top_trace_array();
4190 if (!tr)
4191 return;
4192
4193 pr_info("Running tests on trace events:\n");
4194
4195 list_for_each_entry(file, &tr->events, list) {
4196
4197 call = file->event_call;
4198
4199 /* Only test those that have a probe */
4200 if (!call->class || !call->class->probe)
4201 continue;
4202
4203/*
4204 * Testing syscall events here is pretty useless, but
4205 * we still do it if configured. But this is time consuming.
4206 * What we really need is a user thread to perform the
4207 * syscalls as we test.
4208 */
4209#ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
4210 if (call->class->system &&
4211 strcmp(call->class->system, "syscalls") == 0)
4212 continue;
4213#endif
4214
4215 pr_info("Testing event %s: ", trace_event_name(call));
4216
4217 /*
4218 * If an event is already enabled, someone is using
4219 * it and the self test should not be on.
4220 */
4221 if (file->flags & EVENT_FILE_FL_ENABLED) {
4222 pr_warn("Enabled event during self test!\n");
4223 WARN_ON_ONCE(1);
4224 continue;
4225 }
4226
4227 ftrace_event_enable_disable(file, 1);
4228 event_test_stuff();
4229 ftrace_event_enable_disable(file, 0);
4230
4231 pr_cont("OK\n");
4232 }
4233
4234 /* Now test at the sub system level */
4235
4236 pr_info("Running tests on trace event systems:\n");
4237
4238 list_for_each_entry(dir, &tr->systems, list) {
4239
4240 system = dir->subsystem;
4241
4242 /* the ftrace system is special, skip it */
4243 if (strcmp(system->name, "ftrace") == 0)
4244 continue;
4245
4246 pr_info("Testing event system %s: ", system->name);
4247
4248 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
4249 if (WARN_ON_ONCE(ret)) {
4250 pr_warn("error enabling system %s\n",
4251 system->name);
4252 continue;
4253 }
4254
4255 event_test_stuff();
4256
4257 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
4258 if (WARN_ON_ONCE(ret)) {
4259 pr_warn("error disabling system %s\n",
4260 system->name);
4261 continue;
4262 }
4263
4264 pr_cont("OK\n");
4265 }
4266
4267 /* Test with all events enabled */
4268
4269 pr_info("Running tests on all trace events:\n");
4270 pr_info("Testing all events: ");
4271
4272 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
4273 if (WARN_ON_ONCE(ret)) {
4274 pr_warn("error enabling all events\n");
4275 return;
4276 }
4277
4278 event_test_stuff();
4279
4280 /* reset sysname */
4281 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
4282 if (WARN_ON_ONCE(ret)) {
4283 pr_warn("error disabling all events\n");
4284 return;
4285 }
4286
4287 pr_cont("OK\n");
4288}
4289
4290#ifdef CONFIG_FUNCTION_TRACER
4291
4292static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
4293
4294static struct trace_event_file event_trace_file __initdata;
4295
4296static void __init
4297function_test_events_call(unsigned long ip, unsigned long parent_ip,
4298 struct ftrace_ops *op, struct ftrace_regs *regs)
4299{
4300 struct trace_buffer *buffer;
4301 struct ring_buffer_event *event;
4302 struct ftrace_entry *entry;
4303 unsigned int trace_ctx;
4304 long disabled;
4305 int cpu;
4306
4307 trace_ctx = tracing_gen_ctx();
4308 preempt_disable_notrace();
4309 cpu = raw_smp_processor_id();
4310 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
4311
4312 if (disabled != 1)
4313 goto out;
4314
4315 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
4316 TRACE_FN, sizeof(*entry),
4317 trace_ctx);
4318 if (!event)
4319 goto out;
4320 entry = ring_buffer_event_data(event);
4321 entry->ip = ip;
4322 entry->parent_ip = parent_ip;
4323
4324 event_trigger_unlock_commit(&event_trace_file, buffer, event,
4325 entry, trace_ctx);
4326 out:
4327 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
4328 preempt_enable_notrace();
4329}
4330
4331static struct ftrace_ops trace_ops __initdata =
4332{
4333 .func = function_test_events_call,
4334};
4335
4336static __init void event_trace_self_test_with_function(void)
4337{
4338 int ret;
4339
4340 event_trace_file.tr = top_trace_array();
4341 if (WARN_ON(!event_trace_file.tr))
4342 return;
4343
4344 ret = register_ftrace_function(&trace_ops);
4345 if (WARN_ON(ret < 0)) {
4346 pr_info("Failed to enable function tracer for event tests\n");
4347 return;
4348 }
4349 pr_info("Running tests again, along with the function tracer\n");
4350 event_trace_self_tests();
4351 unregister_ftrace_function(&trace_ops);
4352}
4353#else
4354static __init void event_trace_self_test_with_function(void)
4355{
4356}
4357#endif
4358
4359static __init int event_trace_self_tests_init(void)
4360{
4361 if (!tracing_selftest_disabled) {
4362 event_trace_self_tests();
4363 event_trace_self_test_with_function();
4364 }
4365
4366 return 0;
4367}
4368
4369late_initcall(event_trace_self_tests_init);
4370
4371#endif
1/*
2 * event tracer
3 *
4 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
5 *
6 * - Added format output of fields of the trace point.
7 * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
8 *
9 */
10
11#define pr_fmt(fmt) fmt
12
13#include <linux/workqueue.h>
14#include <linux/spinlock.h>
15#include <linux/kthread.h>
16#include <linux/tracefs.h>
17#include <linux/uaccess.h>
18#include <linux/module.h>
19#include <linux/ctype.h>
20#include <linux/sort.h>
21#include <linux/slab.h>
22#include <linux/delay.h>
23
24#include <trace/events/sched.h>
25
26#include <asm/setup.h>
27
28#include "trace_output.h"
29
30#undef TRACE_SYSTEM
31#define TRACE_SYSTEM "TRACE_SYSTEM"
32
33DEFINE_MUTEX(event_mutex);
34
35LIST_HEAD(ftrace_events);
36static LIST_HEAD(ftrace_generic_fields);
37static LIST_HEAD(ftrace_common_fields);
38
39#define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
40
41static struct kmem_cache *field_cachep;
42static struct kmem_cache *file_cachep;
43
44static inline int system_refcount(struct event_subsystem *system)
45{
46 return system->ref_count;
47}
48
49static int system_refcount_inc(struct event_subsystem *system)
50{
51 return system->ref_count++;
52}
53
54static int system_refcount_dec(struct event_subsystem *system)
55{
56 return --system->ref_count;
57}
58
59/* Double loops, do not use break, only goto's work */
60#define do_for_each_event_file(tr, file) \
61 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
62 list_for_each_entry(file, &tr->events, list)
63
64#define do_for_each_event_file_safe(tr, file) \
65 list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
66 struct trace_event_file *___n; \
67 list_for_each_entry_safe(file, ___n, &tr->events, list)
68
69#define while_for_each_event_file() \
70 }
71
72static struct list_head *
73trace_get_fields(struct trace_event_call *event_call)
74{
75 if (!event_call->class->get_fields)
76 return &event_call->class->fields;
77 return event_call->class->get_fields(event_call);
78}
79
80static struct ftrace_event_field *
81__find_event_field(struct list_head *head, char *name)
82{
83 struct ftrace_event_field *field;
84
85 list_for_each_entry(field, head, link) {
86 if (!strcmp(field->name, name))
87 return field;
88 }
89
90 return NULL;
91}
92
93struct ftrace_event_field *
94trace_find_event_field(struct trace_event_call *call, char *name)
95{
96 struct ftrace_event_field *field;
97 struct list_head *head;
98
99 head = trace_get_fields(call);
100 field = __find_event_field(head, name);
101 if (field)
102 return field;
103
104 field = __find_event_field(&ftrace_generic_fields, name);
105 if (field)
106 return field;
107
108 return __find_event_field(&ftrace_common_fields, name);
109}
110
111static int __trace_define_field(struct list_head *head, const char *type,
112 const char *name, int offset, int size,
113 int is_signed, int filter_type)
114{
115 struct ftrace_event_field *field;
116
117 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
118 if (!field)
119 return -ENOMEM;
120
121 field->name = name;
122 field->type = type;
123
124 if (filter_type == FILTER_OTHER)
125 field->filter_type = filter_assign_type(type);
126 else
127 field->filter_type = filter_type;
128
129 field->offset = offset;
130 field->size = size;
131 field->is_signed = is_signed;
132
133 list_add(&field->link, head);
134
135 return 0;
136}
137
138int trace_define_field(struct trace_event_call *call, const char *type,
139 const char *name, int offset, int size, int is_signed,
140 int filter_type)
141{
142 struct list_head *head;
143
144 if (WARN_ON(!call->class))
145 return 0;
146
147 head = trace_get_fields(call);
148 return __trace_define_field(head, type, name, offset, size,
149 is_signed, filter_type);
150}
151EXPORT_SYMBOL_GPL(trace_define_field);
152
153#define __generic_field(type, item, filter_type) \
154 ret = __trace_define_field(&ftrace_generic_fields, #type, \
155 #item, 0, 0, is_signed_type(type), \
156 filter_type); \
157 if (ret) \
158 return ret;
159
160#define __common_field(type, item) \
161 ret = __trace_define_field(&ftrace_common_fields, #type, \
162 "common_" #item, \
163 offsetof(typeof(ent), item), \
164 sizeof(ent.item), \
165 is_signed_type(type), FILTER_OTHER); \
166 if (ret) \
167 return ret;
168
169static int trace_define_generic_fields(void)
170{
171 int ret;
172
173 __generic_field(int, CPU, FILTER_CPU);
174 __generic_field(int, cpu, FILTER_CPU);
175 __generic_field(char *, COMM, FILTER_COMM);
176 __generic_field(char *, comm, FILTER_COMM);
177
178 return ret;
179}
180
181static int trace_define_common_fields(void)
182{
183 int ret;
184 struct trace_entry ent;
185
186 __common_field(unsigned short, type);
187 __common_field(unsigned char, flags);
188 __common_field(unsigned char, preempt_count);
189 __common_field(int, pid);
190
191 return ret;
192}
193
194static void trace_destroy_fields(struct trace_event_call *call)
195{
196 struct ftrace_event_field *field, *next;
197 struct list_head *head;
198
199 head = trace_get_fields(call);
200 list_for_each_entry_safe(field, next, head, link) {
201 list_del(&field->link);
202 kmem_cache_free(field_cachep, field);
203 }
204}
205
206/*
207 * run-time version of trace_event_get_offsets_<call>() that returns the last
208 * accessible offset of trace fields excluding __dynamic_array bytes
209 */
210int trace_event_get_offsets(struct trace_event_call *call)
211{
212 struct ftrace_event_field *tail;
213 struct list_head *head;
214
215 head = trace_get_fields(call);
216 /*
217 * head->next points to the last field with the largest offset,
218 * since it was added last by trace_define_field()
219 */
220 tail = list_first_entry(head, struct ftrace_event_field, link);
221 return tail->offset + tail->size;
222}
223
224int trace_event_raw_init(struct trace_event_call *call)
225{
226 int id;
227
228 id = register_trace_event(&call->event);
229 if (!id)
230 return -ENODEV;
231
232 return 0;
233}
234EXPORT_SYMBOL_GPL(trace_event_raw_init);
235
236bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
237{
238 struct trace_array *tr = trace_file->tr;
239 struct trace_array_cpu *data;
240 struct trace_pid_list *pid_list;
241
242 pid_list = rcu_dereference_sched(tr->filtered_pids);
243 if (!pid_list)
244 return false;
245
246 data = this_cpu_ptr(tr->trace_buffer.data);
247
248 return data->ignore_pid;
249}
250EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
251
252void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
253 struct trace_event_file *trace_file,
254 unsigned long len)
255{
256 struct trace_event_call *event_call = trace_file->event_call;
257
258 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
259 trace_event_ignore_this_pid(trace_file))
260 return NULL;
261
262 local_save_flags(fbuffer->flags);
263 fbuffer->pc = preempt_count();
264 /*
265 * If CONFIG_PREEMPT is enabled, then the tracepoint itself disables
266 * preemption (adding one to the preempt_count). Since we are
267 * interested in the preempt_count at the time the tracepoint was
268 * hit, we need to subtract one to offset the increment.
269 */
270 if (IS_ENABLED(CONFIG_PREEMPT))
271 fbuffer->pc--;
272 fbuffer->trace_file = trace_file;
273
274 fbuffer->event =
275 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
276 event_call->event.type, len,
277 fbuffer->flags, fbuffer->pc);
278 if (!fbuffer->event)
279 return NULL;
280
281 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
282 return fbuffer->entry;
283}
284EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
285
286int trace_event_reg(struct trace_event_call *call,
287 enum trace_reg type, void *data)
288{
289 struct trace_event_file *file = data;
290
291 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
292 switch (type) {
293 case TRACE_REG_REGISTER:
294 return tracepoint_probe_register(call->tp,
295 call->class->probe,
296 file);
297 case TRACE_REG_UNREGISTER:
298 tracepoint_probe_unregister(call->tp,
299 call->class->probe,
300 file);
301 return 0;
302
303#ifdef CONFIG_PERF_EVENTS
304 case TRACE_REG_PERF_REGISTER:
305 return tracepoint_probe_register(call->tp,
306 call->class->perf_probe,
307 call);
308 case TRACE_REG_PERF_UNREGISTER:
309 tracepoint_probe_unregister(call->tp,
310 call->class->perf_probe,
311 call);
312 return 0;
313 case TRACE_REG_PERF_OPEN:
314 case TRACE_REG_PERF_CLOSE:
315 case TRACE_REG_PERF_ADD:
316 case TRACE_REG_PERF_DEL:
317 return 0;
318#endif
319 }
320 return 0;
321}
322EXPORT_SYMBOL_GPL(trace_event_reg);
323
324void trace_event_enable_cmd_record(bool enable)
325{
326 struct trace_event_file *file;
327 struct trace_array *tr;
328
329 mutex_lock(&event_mutex);
330 do_for_each_event_file(tr, file) {
331
332 if (!(file->flags & EVENT_FILE_FL_ENABLED))
333 continue;
334
335 if (enable) {
336 tracing_start_cmdline_record();
337 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
338 } else {
339 tracing_stop_cmdline_record();
340 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
341 }
342 } while_for_each_event_file();
343 mutex_unlock(&event_mutex);
344}
345
346void trace_event_enable_tgid_record(bool enable)
347{
348 struct trace_event_file *file;
349 struct trace_array *tr;
350
351 mutex_lock(&event_mutex);
352 do_for_each_event_file(tr, file) {
353 if (!(file->flags & EVENT_FILE_FL_ENABLED))
354 continue;
355
356 if (enable) {
357 tracing_start_tgid_record();
358 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
359 } else {
360 tracing_stop_tgid_record();
361 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
362 &file->flags);
363 }
364 } while_for_each_event_file();
365 mutex_unlock(&event_mutex);
366}
367
368static int __ftrace_event_enable_disable(struct trace_event_file *file,
369 int enable, int soft_disable)
370{
371 struct trace_event_call *call = file->event_call;
372 struct trace_array *tr = file->tr;
373 unsigned long file_flags = file->flags;
374 int ret = 0;
375 int disable;
376
377 switch (enable) {
378 case 0:
379 /*
380 * When soft_disable is set and enable is cleared, the sm_ref
381 * reference counter is decremented. If it reaches 0, we want
382 * to clear the SOFT_DISABLED flag but leave the event in the
383 * state that it was. That is, if the event was enabled and
384 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
385 * is set we do not want the event to be enabled before we
386 * clear the bit.
387 *
388 * When soft_disable is not set but the SOFT_MODE flag is,
389 * we do nothing. Do not disable the tracepoint, otherwise
390 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
391 */
392 if (soft_disable) {
393 if (atomic_dec_return(&file->sm_ref) > 0)
394 break;
395 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
396 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
397 } else
398 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
399
400 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
401 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
402 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
403 tracing_stop_cmdline_record();
404 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
405 }
406
407 if (file->flags & EVENT_FILE_FL_RECORDED_TGID) {
408 tracing_stop_tgid_record();
409 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
410 }
411
412 call->class->reg(call, TRACE_REG_UNREGISTER, file);
413 }
414 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
415 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
416 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
417 else
418 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
419 break;
420 case 1:
421 /*
422 * When soft_disable is set and enable is set, we want to
423 * register the tracepoint for the event, but leave the event
424 * as is. That means, if the event was already enabled, we do
425 * nothing (but set SOFT_MODE). If the event is disabled, we
426 * set SOFT_DISABLED before enabling the event tracepoint, so
427 * it still seems to be disabled.
428 */
429 if (!soft_disable)
430 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
431 else {
432 if (atomic_inc_return(&file->sm_ref) > 1)
433 break;
434 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
435 }
436
437 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
438 bool cmd = false, tgid = false;
439
440 /* Keep the event disabled, when going to SOFT_MODE. */
441 if (soft_disable)
442 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
443
444 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
445 cmd = true;
446 tracing_start_cmdline_record();
447 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
448 }
449
450 if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
451 tgid = true;
452 tracing_start_tgid_record();
453 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
454 }
455
456 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
457 if (ret) {
458 if (cmd)
459 tracing_stop_cmdline_record();
460 if (tgid)
461 tracing_stop_tgid_record();
462 pr_info("event trace: Could not enable event "
463 "%s\n", trace_event_name(call));
464 break;
465 }
466 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
467
468 /* WAS_ENABLED gets set but never cleared. */
469 set_bit(EVENT_FILE_FL_WAS_ENABLED_BIT, &file->flags);
470 }
471 break;
472 }
473
474 /* Enable or disable use of trace_buffered_event */
475 if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) !=
476 (file->flags & EVENT_FILE_FL_SOFT_DISABLED)) {
477 if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
478 trace_buffered_event_enable();
479 else
480 trace_buffered_event_disable();
481 }
482
483 return ret;
484}
485
486int trace_event_enable_disable(struct trace_event_file *file,
487 int enable, int soft_disable)
488{
489 return __ftrace_event_enable_disable(file, enable, soft_disable);
490}
491
492static int ftrace_event_enable_disable(struct trace_event_file *file,
493 int enable)
494{
495 return __ftrace_event_enable_disable(file, enable, 0);
496}
497
498static void ftrace_clear_events(struct trace_array *tr)
499{
500 struct trace_event_file *file;
501
502 mutex_lock(&event_mutex);
503 list_for_each_entry(file, &tr->events, list) {
504 ftrace_event_enable_disable(file, 0);
505 }
506 mutex_unlock(&event_mutex);
507}
508
509static void
510event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
511{
512 struct trace_pid_list *pid_list;
513 struct trace_array *tr = data;
514
515 pid_list = rcu_dereference_sched(tr->filtered_pids);
516 trace_filter_add_remove_task(pid_list, NULL, task);
517}
518
519static void
520event_filter_pid_sched_process_fork(void *data,
521 struct task_struct *self,
522 struct task_struct *task)
523{
524 struct trace_pid_list *pid_list;
525 struct trace_array *tr = data;
526
527 pid_list = rcu_dereference_sched(tr->filtered_pids);
528 trace_filter_add_remove_task(pid_list, self, task);
529}
530
531void trace_event_follow_fork(struct trace_array *tr, bool enable)
532{
533 if (enable) {
534 register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
535 tr, INT_MIN);
536 register_trace_prio_sched_process_exit(event_filter_pid_sched_process_exit,
537 tr, INT_MAX);
538 } else {
539 unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
540 tr);
541 unregister_trace_sched_process_exit(event_filter_pid_sched_process_exit,
542 tr);
543 }
544}
545
546static void
547event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
548 struct task_struct *prev, struct task_struct *next)
549{
550 struct trace_array *tr = data;
551 struct trace_pid_list *pid_list;
552
553 pid_list = rcu_dereference_sched(tr->filtered_pids);
554
555 this_cpu_write(tr->trace_buffer.data->ignore_pid,
556 trace_ignore_this_task(pid_list, prev) &&
557 trace_ignore_this_task(pid_list, next));
558}
559
560static void
561event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
562 struct task_struct *prev, struct task_struct *next)
563{
564 struct trace_array *tr = data;
565 struct trace_pid_list *pid_list;
566
567 pid_list = rcu_dereference_sched(tr->filtered_pids);
568
569 this_cpu_write(tr->trace_buffer.data->ignore_pid,
570 trace_ignore_this_task(pid_list, next));
571}
572
573static void
574event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
575{
576 struct trace_array *tr = data;
577 struct trace_pid_list *pid_list;
578
579 /* Nothing to do if we are already tracing */
580 if (!this_cpu_read(tr->trace_buffer.data->ignore_pid))
581 return;
582
583 pid_list = rcu_dereference_sched(tr->filtered_pids);
584
585 this_cpu_write(tr->trace_buffer.data->ignore_pid,
586 trace_ignore_this_task(pid_list, task));
587}
588
589static void
590event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
591{
592 struct trace_array *tr = data;
593 struct trace_pid_list *pid_list;
594
595 /* Nothing to do if we are not tracing */
596 if (this_cpu_read(tr->trace_buffer.data->ignore_pid))
597 return;
598
599 pid_list = rcu_dereference_sched(tr->filtered_pids);
600
601 /* Set tracing if current is enabled */
602 this_cpu_write(tr->trace_buffer.data->ignore_pid,
603 trace_ignore_this_task(pid_list, current));
604}
605
606static void __ftrace_clear_event_pids(struct trace_array *tr)
607{
608 struct trace_pid_list *pid_list;
609 struct trace_event_file *file;
610 int cpu;
611
612 pid_list = rcu_dereference_protected(tr->filtered_pids,
613 lockdep_is_held(&event_mutex));
614 if (!pid_list)
615 return;
616
617 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
618 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
619
620 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
621 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
622
623 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
624 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
625
626 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
627 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
628
629 list_for_each_entry(file, &tr->events, list) {
630 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
631 }
632
633 for_each_possible_cpu(cpu)
634 per_cpu_ptr(tr->trace_buffer.data, cpu)->ignore_pid = false;
635
636 rcu_assign_pointer(tr->filtered_pids, NULL);
637
638 /* Wait till all users are no longer using pid filtering */
639 synchronize_sched();
640
641 trace_free_pid_list(pid_list);
642}
643
644static void ftrace_clear_event_pids(struct trace_array *tr)
645{
646 mutex_lock(&event_mutex);
647 __ftrace_clear_event_pids(tr);
648 mutex_unlock(&event_mutex);
649}
650
651static void __put_system(struct event_subsystem *system)
652{
653 struct event_filter *filter = system->filter;
654
655 WARN_ON_ONCE(system_refcount(system) == 0);
656 if (system_refcount_dec(system))
657 return;
658
659 list_del(&system->list);
660
661 if (filter) {
662 kfree(filter->filter_string);
663 kfree(filter);
664 }
665 kfree_const(system->name);
666 kfree(system);
667}
668
669static void __get_system(struct event_subsystem *system)
670{
671 WARN_ON_ONCE(system_refcount(system) == 0);
672 system_refcount_inc(system);
673}
674
675static void __get_system_dir(struct trace_subsystem_dir *dir)
676{
677 WARN_ON_ONCE(dir->ref_count == 0);
678 dir->ref_count++;
679 __get_system(dir->subsystem);
680}
681
682static void __put_system_dir(struct trace_subsystem_dir *dir)
683{
684 WARN_ON_ONCE(dir->ref_count == 0);
685 /* If the subsystem is about to be freed, the dir must be too */
686 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
687
688 __put_system(dir->subsystem);
689 if (!--dir->ref_count)
690 kfree(dir);
691}
692
693static void put_system(struct trace_subsystem_dir *dir)
694{
695 mutex_lock(&event_mutex);
696 __put_system_dir(dir);
697 mutex_unlock(&event_mutex);
698}
699
700static void remove_subsystem(struct trace_subsystem_dir *dir)
701{
702 if (!dir)
703 return;
704
705 if (!--dir->nr_events) {
706 tracefs_remove_recursive(dir->entry);
707 list_del(&dir->list);
708 __put_system_dir(dir);
709 }
710}
711
712static void remove_event_file_dir(struct trace_event_file *file)
713{
714 struct dentry *dir = file->dir;
715 struct dentry *child;
716
717 if (dir) {
718 spin_lock(&dir->d_lock); /* probably unneeded */
719 list_for_each_entry(child, &dir->d_subdirs, d_child) {
720 if (d_really_is_positive(child)) /* probably unneeded */
721 d_inode(child)->i_private = NULL;
722 }
723 spin_unlock(&dir->d_lock);
724
725 tracefs_remove_recursive(dir);
726 }
727
728 list_del(&file->list);
729 remove_subsystem(file->system);
730 free_event_filter(file->filter);
731 kmem_cache_free(file_cachep, file);
732}
733
734/*
735 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
736 */
737static int
738__ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
739 const char *sub, const char *event, int set)
740{
741 struct trace_event_file *file;
742 struct trace_event_call *call;
743 const char *name;
744 int ret = -EINVAL;
745 int eret = 0;
746
747 list_for_each_entry(file, &tr->events, list) {
748
749 call = file->event_call;
750 name = trace_event_name(call);
751
752 if (!name || !call->class || !call->class->reg)
753 continue;
754
755 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
756 continue;
757
758 if (match &&
759 strcmp(match, name) != 0 &&
760 strcmp(match, call->class->system) != 0)
761 continue;
762
763 if (sub && strcmp(sub, call->class->system) != 0)
764 continue;
765
766 if (event && strcmp(event, name) != 0)
767 continue;
768
769 ret = ftrace_event_enable_disable(file, set);
770
771 /*
772 * Save the first error and return that. Some events
773 * may still have been enabled, but let the user
774 * know that something went wrong.
775 */
776 if (ret && !eret)
777 eret = ret;
778
779 ret = eret;
780 }
781
782 return ret;
783}
784
785static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
786 const char *sub, const char *event, int set)
787{
788 int ret;
789
790 mutex_lock(&event_mutex);
791 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
792 mutex_unlock(&event_mutex);
793
794 return ret;
795}
796
797static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
798{
799 char *event = NULL, *sub = NULL, *match;
800 int ret;
801
802 /*
803 * The buf format can be <subsystem>:<event-name>
804 * *:<event-name> means any event by that name.
805 * :<event-name> is the same.
806 *
807 * <subsystem>:* means all events in that subsystem
808 * <subsystem>: means the same.
809 *
810 * <name> (no ':') means all events in a subsystem with
811 * the name <name> or any event that matches <name>
812 */
813
814 match = strsep(&buf, ":");
815 if (buf) {
816 sub = match;
817 event = buf;
818 match = NULL;
819
820 if (!strlen(sub) || strcmp(sub, "*") == 0)
821 sub = NULL;
822 if (!strlen(event) || strcmp(event, "*") == 0)
823 event = NULL;
824 }
825
826 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
827
828 /* Put back the colon to allow this to be called again */
829 if (buf)
830 *(buf - 1) = ':';
831
832 return ret;
833}
834
835/**
836 * trace_set_clr_event - enable or disable an event
837 * @system: system name to match (NULL for any system)
838 * @event: event name to match (NULL for all events, within system)
839 * @set: 1 to enable, 0 to disable
840 *
841 * This is a way for other parts of the kernel to enable or disable
842 * event recording.
843 *
844 * Returns 0 on success, -EINVAL if the parameters do not match any
845 * registered events.
846 */
847int trace_set_clr_event(const char *system, const char *event, int set)
848{
849 struct trace_array *tr = top_trace_array();
850
851 if (!tr)
852 return -ENODEV;
853
854 return __ftrace_set_clr_event(tr, NULL, system, event, set);
855}
856EXPORT_SYMBOL_GPL(trace_set_clr_event);
857
858/* 128 should be much more than enough */
859#define EVENT_BUF_SIZE 127
860
861static ssize_t
862ftrace_event_write(struct file *file, const char __user *ubuf,
863 size_t cnt, loff_t *ppos)
864{
865 struct trace_parser parser;
866 struct seq_file *m = file->private_data;
867 struct trace_array *tr = m->private;
868 ssize_t read, ret;
869
870 if (!cnt)
871 return 0;
872
873 ret = tracing_update_buffers();
874 if (ret < 0)
875 return ret;
876
877 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
878 return -ENOMEM;
879
880 read = trace_get_user(&parser, ubuf, cnt, ppos);
881
882 if (read >= 0 && trace_parser_loaded((&parser))) {
883 int set = 1;
884
885 if (*parser.buffer == '!')
886 set = 0;
887
888 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
889 if (ret)
890 goto out_put;
891 }
892
893 ret = read;
894
895 out_put:
896 trace_parser_put(&parser);
897
898 return ret;
899}
900
901static void *
902t_next(struct seq_file *m, void *v, loff_t *pos)
903{
904 struct trace_event_file *file = v;
905 struct trace_event_call *call;
906 struct trace_array *tr = m->private;
907
908 (*pos)++;
909
910 list_for_each_entry_continue(file, &tr->events, list) {
911 call = file->event_call;
912 /*
913 * The ftrace subsystem is for showing formats only.
914 * They can not be enabled or disabled via the event files.
915 */
916 if (call->class && call->class->reg &&
917 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
918 return file;
919 }
920
921 return NULL;
922}
923
924static void *t_start(struct seq_file *m, loff_t *pos)
925{
926 struct trace_event_file *file;
927 struct trace_array *tr = m->private;
928 loff_t l;
929
930 mutex_lock(&event_mutex);
931
932 file = list_entry(&tr->events, struct trace_event_file, list);
933 for (l = 0; l <= *pos; ) {
934 file = t_next(m, file, &l);
935 if (!file)
936 break;
937 }
938 return file;
939}
940
941static void *
942s_next(struct seq_file *m, void *v, loff_t *pos)
943{
944 struct trace_event_file *file = v;
945 struct trace_array *tr = m->private;
946
947 (*pos)++;
948
949 list_for_each_entry_continue(file, &tr->events, list) {
950 if (file->flags & EVENT_FILE_FL_ENABLED)
951 return file;
952 }
953
954 return NULL;
955}
956
957static void *s_start(struct seq_file *m, loff_t *pos)
958{
959 struct trace_event_file *file;
960 struct trace_array *tr = m->private;
961 loff_t l;
962
963 mutex_lock(&event_mutex);
964
965 file = list_entry(&tr->events, struct trace_event_file, list);
966 for (l = 0; l <= *pos; ) {
967 file = s_next(m, file, &l);
968 if (!file)
969 break;
970 }
971 return file;
972}
973
974static int t_show(struct seq_file *m, void *v)
975{
976 struct trace_event_file *file = v;
977 struct trace_event_call *call = file->event_call;
978
979 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
980 seq_printf(m, "%s:", call->class->system);
981 seq_printf(m, "%s\n", trace_event_name(call));
982
983 return 0;
984}
985
986static void t_stop(struct seq_file *m, void *p)
987{
988 mutex_unlock(&event_mutex);
989}
990
991static void *
992p_next(struct seq_file *m, void *v, loff_t *pos)
993{
994 struct trace_array *tr = m->private;
995 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
996
997 return trace_pid_next(pid_list, v, pos);
998}
999
1000static void *p_start(struct seq_file *m, loff_t *pos)
1001 __acquires(RCU)
1002{
1003 struct trace_pid_list *pid_list;
1004 struct trace_array *tr = m->private;
1005
1006 /*
1007 * Grab the mutex, to keep calls to p_next() having the same
1008 * tr->filtered_pids as p_start() has.
1009 * If we just passed the tr->filtered_pids around, then RCU would
1010 * have been enough, but doing that makes things more complex.
1011 */
1012 mutex_lock(&event_mutex);
1013 rcu_read_lock_sched();
1014
1015 pid_list = rcu_dereference_sched(tr->filtered_pids);
1016
1017 if (!pid_list)
1018 return NULL;
1019
1020 return trace_pid_start(pid_list, pos);
1021}
1022
1023static void p_stop(struct seq_file *m, void *p)
1024 __releases(RCU)
1025{
1026 rcu_read_unlock_sched();
1027 mutex_unlock(&event_mutex);
1028}
1029
1030static ssize_t
1031event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1032 loff_t *ppos)
1033{
1034 struct trace_event_file *file;
1035 unsigned long flags;
1036 char buf[4] = "0";
1037
1038 mutex_lock(&event_mutex);
1039 file = event_file_data(filp);
1040 if (likely(file))
1041 flags = file->flags;
1042 mutex_unlock(&event_mutex);
1043
1044 if (!file)
1045 return -ENODEV;
1046
1047 if (flags & EVENT_FILE_FL_ENABLED &&
1048 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1049 strcpy(buf, "1");
1050
1051 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1052 flags & EVENT_FILE_FL_SOFT_MODE)
1053 strcat(buf, "*");
1054
1055 strcat(buf, "\n");
1056
1057 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1058}
1059
1060static ssize_t
1061event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1062 loff_t *ppos)
1063{
1064 struct trace_event_file *file;
1065 unsigned long val;
1066 int ret;
1067
1068 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1069 if (ret)
1070 return ret;
1071
1072 ret = tracing_update_buffers();
1073 if (ret < 0)
1074 return ret;
1075
1076 switch (val) {
1077 case 0:
1078 case 1:
1079 ret = -ENODEV;
1080 mutex_lock(&event_mutex);
1081 file = event_file_data(filp);
1082 if (likely(file))
1083 ret = ftrace_event_enable_disable(file, val);
1084 mutex_unlock(&event_mutex);
1085 break;
1086
1087 default:
1088 return -EINVAL;
1089 }
1090
1091 *ppos += cnt;
1092
1093 return ret ? ret : cnt;
1094}
1095
1096static ssize_t
1097system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1098 loff_t *ppos)
1099{
1100 const char set_to_char[4] = { '?', '0', '1', 'X' };
1101 struct trace_subsystem_dir *dir = filp->private_data;
1102 struct event_subsystem *system = dir->subsystem;
1103 struct trace_event_call *call;
1104 struct trace_event_file *file;
1105 struct trace_array *tr = dir->tr;
1106 char buf[2];
1107 int set = 0;
1108 int ret;
1109
1110 mutex_lock(&event_mutex);
1111 list_for_each_entry(file, &tr->events, list) {
1112 call = file->event_call;
1113 if (!trace_event_name(call) || !call->class || !call->class->reg)
1114 continue;
1115
1116 if (system && strcmp(call->class->system, system->name) != 0)
1117 continue;
1118
1119 /*
1120 * We need to find out if all the events are set
1121 * or if all events or cleared, or if we have
1122 * a mixture.
1123 */
1124 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1125
1126 /*
1127 * If we have a mixture, no need to look further.
1128 */
1129 if (set == 3)
1130 break;
1131 }
1132 mutex_unlock(&event_mutex);
1133
1134 buf[0] = set_to_char[set];
1135 buf[1] = '\n';
1136
1137 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1138
1139 return ret;
1140}
1141
1142static ssize_t
1143system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1144 loff_t *ppos)
1145{
1146 struct trace_subsystem_dir *dir = filp->private_data;
1147 struct event_subsystem *system = dir->subsystem;
1148 const char *name = NULL;
1149 unsigned long val;
1150 ssize_t ret;
1151
1152 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1153 if (ret)
1154 return ret;
1155
1156 ret = tracing_update_buffers();
1157 if (ret < 0)
1158 return ret;
1159
1160 if (val != 0 && val != 1)
1161 return -EINVAL;
1162
1163 /*
1164 * Opening of "enable" adds a ref count to system,
1165 * so the name is safe to use.
1166 */
1167 if (system)
1168 name = system->name;
1169
1170 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1171 if (ret)
1172 goto out;
1173
1174 ret = cnt;
1175
1176out:
1177 *ppos += cnt;
1178
1179 return ret;
1180}
1181
1182enum {
1183 FORMAT_HEADER = 1,
1184 FORMAT_FIELD_SEPERATOR = 2,
1185 FORMAT_PRINTFMT = 3,
1186};
1187
1188static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1189{
1190 struct trace_event_call *call = event_file_data(m->private);
1191 struct list_head *common_head = &ftrace_common_fields;
1192 struct list_head *head = trace_get_fields(call);
1193 struct list_head *node = v;
1194
1195 (*pos)++;
1196
1197 switch ((unsigned long)v) {
1198 case FORMAT_HEADER:
1199 node = common_head;
1200 break;
1201
1202 case FORMAT_FIELD_SEPERATOR:
1203 node = head;
1204 break;
1205
1206 case FORMAT_PRINTFMT:
1207 /* all done */
1208 return NULL;
1209 }
1210
1211 node = node->prev;
1212 if (node == common_head)
1213 return (void *)FORMAT_FIELD_SEPERATOR;
1214 else if (node == head)
1215 return (void *)FORMAT_PRINTFMT;
1216 else
1217 return node;
1218}
1219
1220static int f_show(struct seq_file *m, void *v)
1221{
1222 struct trace_event_call *call = event_file_data(m->private);
1223 struct ftrace_event_field *field;
1224 const char *array_descriptor;
1225
1226 switch ((unsigned long)v) {
1227 case FORMAT_HEADER:
1228 seq_printf(m, "name: %s\n", trace_event_name(call));
1229 seq_printf(m, "ID: %d\n", call->event.type);
1230 seq_puts(m, "format:\n");
1231 return 0;
1232
1233 case FORMAT_FIELD_SEPERATOR:
1234 seq_putc(m, '\n');
1235 return 0;
1236
1237 case FORMAT_PRINTFMT:
1238 seq_printf(m, "\nprint fmt: %s\n",
1239 call->print_fmt);
1240 return 0;
1241 }
1242
1243 field = list_entry(v, struct ftrace_event_field, link);
1244 /*
1245 * Smartly shows the array type(except dynamic array).
1246 * Normal:
1247 * field:TYPE VAR
1248 * If TYPE := TYPE[LEN], it is shown:
1249 * field:TYPE VAR[LEN]
1250 */
1251 array_descriptor = strchr(field->type, '[');
1252
1253 if (!strncmp(field->type, "__data_loc", 10))
1254 array_descriptor = NULL;
1255
1256 if (!array_descriptor)
1257 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1258 field->type, field->name, field->offset,
1259 field->size, !!field->is_signed);
1260 else
1261 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1262 (int)(array_descriptor - field->type),
1263 field->type, field->name,
1264 array_descriptor, field->offset,
1265 field->size, !!field->is_signed);
1266
1267 return 0;
1268}
1269
1270static void *f_start(struct seq_file *m, loff_t *pos)
1271{
1272 void *p = (void *)FORMAT_HEADER;
1273 loff_t l = 0;
1274
1275 /* ->stop() is called even if ->start() fails */
1276 mutex_lock(&event_mutex);
1277 if (!event_file_data(m->private))
1278 return ERR_PTR(-ENODEV);
1279
1280 while (l < *pos && p)
1281 p = f_next(m, p, &l);
1282
1283 return p;
1284}
1285
1286static void f_stop(struct seq_file *m, void *p)
1287{
1288 mutex_unlock(&event_mutex);
1289}
1290
1291static const struct seq_operations trace_format_seq_ops = {
1292 .start = f_start,
1293 .next = f_next,
1294 .stop = f_stop,
1295 .show = f_show,
1296};
1297
1298static int trace_format_open(struct inode *inode, struct file *file)
1299{
1300 struct seq_file *m;
1301 int ret;
1302
1303 ret = seq_open(file, &trace_format_seq_ops);
1304 if (ret < 0)
1305 return ret;
1306
1307 m = file->private_data;
1308 m->private = file;
1309
1310 return 0;
1311}
1312
1313static ssize_t
1314event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1315{
1316 int id = (long)event_file_data(filp);
1317 char buf[32];
1318 int len;
1319
1320 if (*ppos)
1321 return 0;
1322
1323 if (unlikely(!id))
1324 return -ENODEV;
1325
1326 len = sprintf(buf, "%d\n", id);
1327
1328 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1329}
1330
1331static ssize_t
1332event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1333 loff_t *ppos)
1334{
1335 struct trace_event_file *file;
1336 struct trace_seq *s;
1337 int r = -ENODEV;
1338
1339 if (*ppos)
1340 return 0;
1341
1342 s = kmalloc(sizeof(*s), GFP_KERNEL);
1343
1344 if (!s)
1345 return -ENOMEM;
1346
1347 trace_seq_init(s);
1348
1349 mutex_lock(&event_mutex);
1350 file = event_file_data(filp);
1351 if (file)
1352 print_event_filter(file, s);
1353 mutex_unlock(&event_mutex);
1354
1355 if (file)
1356 r = simple_read_from_buffer(ubuf, cnt, ppos,
1357 s->buffer, trace_seq_used(s));
1358
1359 kfree(s);
1360
1361 return r;
1362}
1363
1364static ssize_t
1365event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1366 loff_t *ppos)
1367{
1368 struct trace_event_file *file;
1369 char *buf;
1370 int err = -ENODEV;
1371
1372 if (cnt >= PAGE_SIZE)
1373 return -EINVAL;
1374
1375 buf = memdup_user_nul(ubuf, cnt);
1376 if (IS_ERR(buf))
1377 return PTR_ERR(buf);
1378
1379 mutex_lock(&event_mutex);
1380 file = event_file_data(filp);
1381 if (file)
1382 err = apply_event_filter(file, buf);
1383 mutex_unlock(&event_mutex);
1384
1385 kfree(buf);
1386 if (err < 0)
1387 return err;
1388
1389 *ppos += cnt;
1390
1391 return cnt;
1392}
1393
1394static LIST_HEAD(event_subsystems);
1395
1396static int subsystem_open(struct inode *inode, struct file *filp)
1397{
1398 struct event_subsystem *system = NULL;
1399 struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1400 struct trace_array *tr;
1401 int ret;
1402
1403 if (tracing_is_disabled())
1404 return -ENODEV;
1405
1406 /* Make sure the system still exists */
1407 mutex_lock(&event_mutex);
1408 mutex_lock(&trace_types_lock);
1409 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1410 list_for_each_entry(dir, &tr->systems, list) {
1411 if (dir == inode->i_private) {
1412 /* Don't open systems with no events */
1413 if (dir->nr_events) {
1414 __get_system_dir(dir);
1415 system = dir->subsystem;
1416 }
1417 goto exit_loop;
1418 }
1419 }
1420 }
1421 exit_loop:
1422 mutex_unlock(&trace_types_lock);
1423 mutex_unlock(&event_mutex);
1424
1425 if (!system)
1426 return -ENODEV;
1427
1428 /* Some versions of gcc think dir can be uninitialized here */
1429 WARN_ON(!dir);
1430
1431 /* Still need to increment the ref count of the system */
1432 if (trace_array_get(tr) < 0) {
1433 put_system(dir);
1434 return -ENODEV;
1435 }
1436
1437 ret = tracing_open_generic(inode, filp);
1438 if (ret < 0) {
1439 trace_array_put(tr);
1440 put_system(dir);
1441 }
1442
1443 return ret;
1444}
1445
1446static int system_tr_open(struct inode *inode, struct file *filp)
1447{
1448 struct trace_subsystem_dir *dir;
1449 struct trace_array *tr = inode->i_private;
1450 int ret;
1451
1452 if (tracing_is_disabled())
1453 return -ENODEV;
1454
1455 if (trace_array_get(tr) < 0)
1456 return -ENODEV;
1457
1458 /* Make a temporary dir that has no system but points to tr */
1459 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1460 if (!dir) {
1461 trace_array_put(tr);
1462 return -ENOMEM;
1463 }
1464
1465 dir->tr = tr;
1466
1467 ret = tracing_open_generic(inode, filp);
1468 if (ret < 0) {
1469 trace_array_put(tr);
1470 kfree(dir);
1471 return ret;
1472 }
1473
1474 filp->private_data = dir;
1475
1476 return 0;
1477}
1478
1479static int subsystem_release(struct inode *inode, struct file *file)
1480{
1481 struct trace_subsystem_dir *dir = file->private_data;
1482
1483 trace_array_put(dir->tr);
1484
1485 /*
1486 * If dir->subsystem is NULL, then this is a temporary
1487 * descriptor that was made for a trace_array to enable
1488 * all subsystems.
1489 */
1490 if (dir->subsystem)
1491 put_system(dir);
1492 else
1493 kfree(dir);
1494
1495 return 0;
1496}
1497
1498static ssize_t
1499subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1500 loff_t *ppos)
1501{
1502 struct trace_subsystem_dir *dir = filp->private_data;
1503 struct event_subsystem *system = dir->subsystem;
1504 struct trace_seq *s;
1505 int r;
1506
1507 if (*ppos)
1508 return 0;
1509
1510 s = kmalloc(sizeof(*s), GFP_KERNEL);
1511 if (!s)
1512 return -ENOMEM;
1513
1514 trace_seq_init(s);
1515
1516 print_subsystem_event_filter(system, s);
1517 r = simple_read_from_buffer(ubuf, cnt, ppos,
1518 s->buffer, trace_seq_used(s));
1519
1520 kfree(s);
1521
1522 return r;
1523}
1524
1525static ssize_t
1526subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1527 loff_t *ppos)
1528{
1529 struct trace_subsystem_dir *dir = filp->private_data;
1530 char *buf;
1531 int err;
1532
1533 if (cnt >= PAGE_SIZE)
1534 return -EINVAL;
1535
1536 buf = memdup_user_nul(ubuf, cnt);
1537 if (IS_ERR(buf))
1538 return PTR_ERR(buf);
1539
1540 err = apply_subsystem_event_filter(dir, buf);
1541 kfree(buf);
1542 if (err < 0)
1543 return err;
1544
1545 *ppos += cnt;
1546
1547 return cnt;
1548}
1549
1550static ssize_t
1551show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1552{
1553 int (*func)(struct trace_seq *s) = filp->private_data;
1554 struct trace_seq *s;
1555 int r;
1556
1557 if (*ppos)
1558 return 0;
1559
1560 s = kmalloc(sizeof(*s), GFP_KERNEL);
1561 if (!s)
1562 return -ENOMEM;
1563
1564 trace_seq_init(s);
1565
1566 func(s);
1567 r = simple_read_from_buffer(ubuf, cnt, ppos,
1568 s->buffer, trace_seq_used(s));
1569
1570 kfree(s);
1571
1572 return r;
1573}
1574
1575static void ignore_task_cpu(void *data)
1576{
1577 struct trace_array *tr = data;
1578 struct trace_pid_list *pid_list;
1579
1580 /*
1581 * This function is called by on_each_cpu() while the
1582 * event_mutex is held.
1583 */
1584 pid_list = rcu_dereference_protected(tr->filtered_pids,
1585 mutex_is_locked(&event_mutex));
1586
1587 this_cpu_write(tr->trace_buffer.data->ignore_pid,
1588 trace_ignore_this_task(pid_list, current));
1589}
1590
1591static ssize_t
1592ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1593 size_t cnt, loff_t *ppos)
1594{
1595 struct seq_file *m = filp->private_data;
1596 struct trace_array *tr = m->private;
1597 struct trace_pid_list *filtered_pids = NULL;
1598 struct trace_pid_list *pid_list;
1599 struct trace_event_file *file;
1600 ssize_t ret;
1601
1602 if (!cnt)
1603 return 0;
1604
1605 ret = tracing_update_buffers();
1606 if (ret < 0)
1607 return ret;
1608
1609 mutex_lock(&event_mutex);
1610
1611 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1612 lockdep_is_held(&event_mutex));
1613
1614 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
1615 if (ret < 0)
1616 goto out;
1617
1618 rcu_assign_pointer(tr->filtered_pids, pid_list);
1619
1620 list_for_each_entry(file, &tr->events, list) {
1621 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1622 }
1623
1624 if (filtered_pids) {
1625 synchronize_sched();
1626 trace_free_pid_list(filtered_pids);
1627 } else if (pid_list) {
1628 /*
1629 * Register a probe that is called before all other probes
1630 * to set ignore_pid if next or prev do not match.
1631 * Register a probe this is called after all other probes
1632 * to only keep ignore_pid set if next pid matches.
1633 */
1634 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1635 tr, INT_MAX);
1636 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1637 tr, 0);
1638
1639 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1640 tr, INT_MAX);
1641 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1642 tr, 0);
1643
1644 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1645 tr, INT_MAX);
1646 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1647 tr, 0);
1648
1649 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1650 tr, INT_MAX);
1651 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1652 tr, 0);
1653 }
1654
1655 /*
1656 * Ignoring of pids is done at task switch. But we have to
1657 * check for those tasks that are currently running.
1658 * Always do this in case a pid was appended or removed.
1659 */
1660 on_each_cpu(ignore_task_cpu, tr, 1);
1661
1662 out:
1663 mutex_unlock(&event_mutex);
1664
1665 if (ret > 0)
1666 *ppos += ret;
1667
1668 return ret;
1669}
1670
1671static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1672static int ftrace_event_set_open(struct inode *inode, struct file *file);
1673static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
1674static int ftrace_event_release(struct inode *inode, struct file *file);
1675
1676static const struct seq_operations show_event_seq_ops = {
1677 .start = t_start,
1678 .next = t_next,
1679 .show = t_show,
1680 .stop = t_stop,
1681};
1682
1683static const struct seq_operations show_set_event_seq_ops = {
1684 .start = s_start,
1685 .next = s_next,
1686 .show = t_show,
1687 .stop = t_stop,
1688};
1689
1690static const struct seq_operations show_set_pid_seq_ops = {
1691 .start = p_start,
1692 .next = p_next,
1693 .show = trace_pid_show,
1694 .stop = p_stop,
1695};
1696
1697static const struct file_operations ftrace_avail_fops = {
1698 .open = ftrace_event_avail_open,
1699 .read = seq_read,
1700 .llseek = seq_lseek,
1701 .release = seq_release,
1702};
1703
1704static const struct file_operations ftrace_set_event_fops = {
1705 .open = ftrace_event_set_open,
1706 .read = seq_read,
1707 .write = ftrace_event_write,
1708 .llseek = seq_lseek,
1709 .release = ftrace_event_release,
1710};
1711
1712static const struct file_operations ftrace_set_event_pid_fops = {
1713 .open = ftrace_event_set_pid_open,
1714 .read = seq_read,
1715 .write = ftrace_event_pid_write,
1716 .llseek = seq_lseek,
1717 .release = ftrace_event_release,
1718};
1719
1720static const struct file_operations ftrace_enable_fops = {
1721 .open = tracing_open_generic,
1722 .read = event_enable_read,
1723 .write = event_enable_write,
1724 .llseek = default_llseek,
1725};
1726
1727static const struct file_operations ftrace_event_format_fops = {
1728 .open = trace_format_open,
1729 .read = seq_read,
1730 .llseek = seq_lseek,
1731 .release = seq_release,
1732};
1733
1734static const struct file_operations ftrace_event_id_fops = {
1735 .read = event_id_read,
1736 .llseek = default_llseek,
1737};
1738
1739static const struct file_operations ftrace_event_filter_fops = {
1740 .open = tracing_open_generic,
1741 .read = event_filter_read,
1742 .write = event_filter_write,
1743 .llseek = default_llseek,
1744};
1745
1746static const struct file_operations ftrace_subsystem_filter_fops = {
1747 .open = subsystem_open,
1748 .read = subsystem_filter_read,
1749 .write = subsystem_filter_write,
1750 .llseek = default_llseek,
1751 .release = subsystem_release,
1752};
1753
1754static const struct file_operations ftrace_system_enable_fops = {
1755 .open = subsystem_open,
1756 .read = system_enable_read,
1757 .write = system_enable_write,
1758 .llseek = default_llseek,
1759 .release = subsystem_release,
1760};
1761
1762static const struct file_operations ftrace_tr_enable_fops = {
1763 .open = system_tr_open,
1764 .read = system_enable_read,
1765 .write = system_enable_write,
1766 .llseek = default_llseek,
1767 .release = subsystem_release,
1768};
1769
1770static const struct file_operations ftrace_show_header_fops = {
1771 .open = tracing_open_generic,
1772 .read = show_header,
1773 .llseek = default_llseek,
1774};
1775
1776static int
1777ftrace_event_open(struct inode *inode, struct file *file,
1778 const struct seq_operations *seq_ops)
1779{
1780 struct seq_file *m;
1781 int ret;
1782
1783 ret = seq_open(file, seq_ops);
1784 if (ret < 0)
1785 return ret;
1786 m = file->private_data;
1787 /* copy tr over to seq ops */
1788 m->private = inode->i_private;
1789
1790 return ret;
1791}
1792
1793static int ftrace_event_release(struct inode *inode, struct file *file)
1794{
1795 struct trace_array *tr = inode->i_private;
1796
1797 trace_array_put(tr);
1798
1799 return seq_release(inode, file);
1800}
1801
1802static int
1803ftrace_event_avail_open(struct inode *inode, struct file *file)
1804{
1805 const struct seq_operations *seq_ops = &show_event_seq_ops;
1806
1807 return ftrace_event_open(inode, file, seq_ops);
1808}
1809
1810static int
1811ftrace_event_set_open(struct inode *inode, struct file *file)
1812{
1813 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1814 struct trace_array *tr = inode->i_private;
1815 int ret;
1816
1817 if (trace_array_get(tr) < 0)
1818 return -ENODEV;
1819
1820 if ((file->f_mode & FMODE_WRITE) &&
1821 (file->f_flags & O_TRUNC))
1822 ftrace_clear_events(tr);
1823
1824 ret = ftrace_event_open(inode, file, seq_ops);
1825 if (ret < 0)
1826 trace_array_put(tr);
1827 return ret;
1828}
1829
1830static int
1831ftrace_event_set_pid_open(struct inode *inode, struct file *file)
1832{
1833 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
1834 struct trace_array *tr = inode->i_private;
1835 int ret;
1836
1837 if (trace_array_get(tr) < 0)
1838 return -ENODEV;
1839
1840 if ((file->f_mode & FMODE_WRITE) &&
1841 (file->f_flags & O_TRUNC))
1842 ftrace_clear_event_pids(tr);
1843
1844 ret = ftrace_event_open(inode, file, seq_ops);
1845 if (ret < 0)
1846 trace_array_put(tr);
1847 return ret;
1848}
1849
1850static struct event_subsystem *
1851create_new_subsystem(const char *name)
1852{
1853 struct event_subsystem *system;
1854
1855 /* need to create new entry */
1856 system = kmalloc(sizeof(*system), GFP_KERNEL);
1857 if (!system)
1858 return NULL;
1859
1860 system->ref_count = 1;
1861
1862 /* Only allocate if dynamic (kprobes and modules) */
1863 system->name = kstrdup_const(name, GFP_KERNEL);
1864 if (!system->name)
1865 goto out_free;
1866
1867 system->filter = NULL;
1868
1869 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1870 if (!system->filter)
1871 goto out_free;
1872
1873 list_add(&system->list, &event_subsystems);
1874
1875 return system;
1876
1877 out_free:
1878 kfree_const(system->name);
1879 kfree(system);
1880 return NULL;
1881}
1882
1883static struct dentry *
1884event_subsystem_dir(struct trace_array *tr, const char *name,
1885 struct trace_event_file *file, struct dentry *parent)
1886{
1887 struct trace_subsystem_dir *dir;
1888 struct event_subsystem *system;
1889 struct dentry *entry;
1890
1891 /* First see if we did not already create this dir */
1892 list_for_each_entry(dir, &tr->systems, list) {
1893 system = dir->subsystem;
1894 if (strcmp(system->name, name) == 0) {
1895 dir->nr_events++;
1896 file->system = dir;
1897 return dir->entry;
1898 }
1899 }
1900
1901 /* Now see if the system itself exists. */
1902 list_for_each_entry(system, &event_subsystems, list) {
1903 if (strcmp(system->name, name) == 0)
1904 break;
1905 }
1906 /* Reset system variable when not found */
1907 if (&system->list == &event_subsystems)
1908 system = NULL;
1909
1910 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1911 if (!dir)
1912 goto out_fail;
1913
1914 if (!system) {
1915 system = create_new_subsystem(name);
1916 if (!system)
1917 goto out_free;
1918 } else
1919 __get_system(system);
1920
1921 dir->entry = tracefs_create_dir(name, parent);
1922 if (!dir->entry) {
1923 pr_warn("Failed to create system directory %s\n", name);
1924 __put_system(system);
1925 goto out_free;
1926 }
1927
1928 dir->tr = tr;
1929 dir->ref_count = 1;
1930 dir->nr_events = 1;
1931 dir->subsystem = system;
1932 file->system = dir;
1933
1934 entry = tracefs_create_file("filter", 0644, dir->entry, dir,
1935 &ftrace_subsystem_filter_fops);
1936 if (!entry) {
1937 kfree(system->filter);
1938 system->filter = NULL;
1939 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
1940 }
1941
1942 trace_create_file("enable", 0644, dir->entry, dir,
1943 &ftrace_system_enable_fops);
1944
1945 list_add(&dir->list, &tr->systems);
1946
1947 return dir->entry;
1948
1949 out_free:
1950 kfree(dir);
1951 out_fail:
1952 /* Only print this message if failed on memory allocation */
1953 if (!dir || !system)
1954 pr_warn("No memory to create event subsystem %s\n", name);
1955 return NULL;
1956}
1957
1958static int
1959event_create_dir(struct dentry *parent, struct trace_event_file *file)
1960{
1961 struct trace_event_call *call = file->event_call;
1962 struct trace_array *tr = file->tr;
1963 struct list_head *head;
1964 struct dentry *d_events;
1965 const char *name;
1966 int ret;
1967
1968 /*
1969 * If the trace point header did not define TRACE_SYSTEM
1970 * then the system would be called "TRACE_SYSTEM".
1971 */
1972 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1973 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1974 if (!d_events)
1975 return -ENOMEM;
1976 } else
1977 d_events = parent;
1978
1979 name = trace_event_name(call);
1980 file->dir = tracefs_create_dir(name, d_events);
1981 if (!file->dir) {
1982 pr_warn("Could not create tracefs '%s' directory\n", name);
1983 return -1;
1984 }
1985
1986 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1987 trace_create_file("enable", 0644, file->dir, file,
1988 &ftrace_enable_fops);
1989
1990#ifdef CONFIG_PERF_EVENTS
1991 if (call->event.type && call->class->reg)
1992 trace_create_file("id", 0444, file->dir,
1993 (void *)(long)call->event.type,
1994 &ftrace_event_id_fops);
1995#endif
1996
1997 /*
1998 * Other events may have the same class. Only update
1999 * the fields if they are not already defined.
2000 */
2001 head = trace_get_fields(call);
2002 if (list_empty(head)) {
2003 ret = call->class->define_fields(call);
2004 if (ret < 0) {
2005 pr_warn("Could not initialize trace point events/%s\n",
2006 name);
2007 return -1;
2008 }
2009 }
2010 trace_create_file("filter", 0644, file->dir, file,
2011 &ftrace_event_filter_fops);
2012
2013 /*
2014 * Only event directories that can be enabled should have
2015 * triggers.
2016 */
2017 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2018 trace_create_file("trigger", 0644, file->dir, file,
2019 &event_trigger_fops);
2020
2021#ifdef CONFIG_HIST_TRIGGERS
2022 trace_create_file("hist", 0444, file->dir, file,
2023 &event_hist_fops);
2024#endif
2025 trace_create_file("format", 0444, file->dir, call,
2026 &ftrace_event_format_fops);
2027
2028 return 0;
2029}
2030
2031static void remove_event_from_tracers(struct trace_event_call *call)
2032{
2033 struct trace_event_file *file;
2034 struct trace_array *tr;
2035
2036 do_for_each_event_file_safe(tr, file) {
2037 if (file->event_call != call)
2038 continue;
2039
2040 remove_event_file_dir(file);
2041 /*
2042 * The do_for_each_event_file_safe() is
2043 * a double loop. After finding the call for this
2044 * trace_array, we use break to jump to the next
2045 * trace_array.
2046 */
2047 break;
2048 } while_for_each_event_file();
2049}
2050
2051static void event_remove(struct trace_event_call *call)
2052{
2053 struct trace_array *tr;
2054 struct trace_event_file *file;
2055
2056 do_for_each_event_file(tr, file) {
2057 if (file->event_call != call)
2058 continue;
2059
2060 if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
2061 tr->clear_trace = true;
2062
2063 ftrace_event_enable_disable(file, 0);
2064 /*
2065 * The do_for_each_event_file() is
2066 * a double loop. After finding the call for this
2067 * trace_array, we use break to jump to the next
2068 * trace_array.
2069 */
2070 break;
2071 } while_for_each_event_file();
2072
2073 if (call->event.funcs)
2074 __unregister_trace_event(&call->event);
2075 remove_event_from_tracers(call);
2076 list_del(&call->list);
2077}
2078
2079static int event_init(struct trace_event_call *call)
2080{
2081 int ret = 0;
2082 const char *name;
2083
2084 name = trace_event_name(call);
2085 if (WARN_ON(!name))
2086 return -EINVAL;
2087
2088 if (call->class->raw_init) {
2089 ret = call->class->raw_init(call);
2090 if (ret < 0 && ret != -ENOSYS)
2091 pr_warn("Could not initialize trace events/%s\n", name);
2092 }
2093
2094 return ret;
2095}
2096
2097static int
2098__register_event(struct trace_event_call *call, struct module *mod)
2099{
2100 int ret;
2101
2102 ret = event_init(call);
2103 if (ret < 0)
2104 return ret;
2105
2106 list_add(&call->list, &ftrace_events);
2107 call->mod = mod;
2108
2109 return 0;
2110}
2111
2112static char *eval_replace(char *ptr, struct trace_eval_map *map, int len)
2113{
2114 int rlen;
2115 int elen;
2116
2117 /* Find the length of the eval value as a string */
2118 elen = snprintf(ptr, 0, "%ld", map->eval_value);
2119 /* Make sure there's enough room to replace the string with the value */
2120 if (len < elen)
2121 return NULL;
2122
2123 snprintf(ptr, elen + 1, "%ld", map->eval_value);
2124
2125 /* Get the rest of the string of ptr */
2126 rlen = strlen(ptr + len);
2127 memmove(ptr + elen, ptr + len, rlen);
2128 /* Make sure we end the new string */
2129 ptr[elen + rlen] = 0;
2130
2131 return ptr + elen;
2132}
2133
2134static void update_event_printk(struct trace_event_call *call,
2135 struct trace_eval_map *map)
2136{
2137 char *ptr;
2138 int quote = 0;
2139 int len = strlen(map->eval_string);
2140
2141 for (ptr = call->print_fmt; *ptr; ptr++) {
2142 if (*ptr == '\\') {
2143 ptr++;
2144 /* paranoid */
2145 if (!*ptr)
2146 break;
2147 continue;
2148 }
2149 if (*ptr == '"') {
2150 quote ^= 1;
2151 continue;
2152 }
2153 if (quote)
2154 continue;
2155 if (isdigit(*ptr)) {
2156 /* skip numbers */
2157 do {
2158 ptr++;
2159 /* Check for alpha chars like ULL */
2160 } while (isalnum(*ptr));
2161 if (!*ptr)
2162 break;
2163 /*
2164 * A number must have some kind of delimiter after
2165 * it, and we can ignore that too.
2166 */
2167 continue;
2168 }
2169 if (isalpha(*ptr) || *ptr == '_') {
2170 if (strncmp(map->eval_string, ptr, len) == 0 &&
2171 !isalnum(ptr[len]) && ptr[len] != '_') {
2172 ptr = eval_replace(ptr, map, len);
2173 /* enum/sizeof string smaller than value */
2174 if (WARN_ON_ONCE(!ptr))
2175 return;
2176 /*
2177 * No need to decrement here, as eval_replace()
2178 * returns the pointer to the character passed
2179 * the eval, and two evals can not be placed
2180 * back to back without something in between.
2181 * We can skip that something in between.
2182 */
2183 continue;
2184 }
2185 skip_more:
2186 do {
2187 ptr++;
2188 } while (isalnum(*ptr) || *ptr == '_');
2189 if (!*ptr)
2190 break;
2191 /*
2192 * If what comes after this variable is a '.' or
2193 * '->' then we can continue to ignore that string.
2194 */
2195 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2196 ptr += *ptr == '.' ? 1 : 2;
2197 if (!*ptr)
2198 break;
2199 goto skip_more;
2200 }
2201 /*
2202 * Once again, we can skip the delimiter that came
2203 * after the string.
2204 */
2205 continue;
2206 }
2207 }
2208}
2209
2210void trace_event_eval_update(struct trace_eval_map **map, int len)
2211{
2212 struct trace_event_call *call, *p;
2213 const char *last_system = NULL;
2214 bool first = false;
2215 int last_i;
2216 int i;
2217
2218 down_write(&trace_event_sem);
2219 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2220 /* events are usually grouped together with systems */
2221 if (!last_system || call->class->system != last_system) {
2222 first = true;
2223 last_i = 0;
2224 last_system = call->class->system;
2225 }
2226
2227 /*
2228 * Since calls are grouped by systems, the likelyhood that the
2229 * next call in the iteration belongs to the same system as the
2230 * previous call is high. As an optimization, we skip seaching
2231 * for a map[] that matches the call's system if the last call
2232 * was from the same system. That's what last_i is for. If the
2233 * call has the same system as the previous call, then last_i
2234 * will be the index of the first map[] that has a matching
2235 * system.
2236 */
2237 for (i = last_i; i < len; i++) {
2238 if (call->class->system == map[i]->system) {
2239 /* Save the first system if need be */
2240 if (first) {
2241 last_i = i;
2242 first = false;
2243 }
2244 update_event_printk(call, map[i]);
2245 }
2246 }
2247 }
2248 up_write(&trace_event_sem);
2249}
2250
2251static struct trace_event_file *
2252trace_create_new_event(struct trace_event_call *call,
2253 struct trace_array *tr)
2254{
2255 struct trace_event_file *file;
2256
2257 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2258 if (!file)
2259 return NULL;
2260
2261 file->event_call = call;
2262 file->tr = tr;
2263 atomic_set(&file->sm_ref, 0);
2264 atomic_set(&file->tm_ref, 0);
2265 INIT_LIST_HEAD(&file->triggers);
2266 list_add(&file->list, &tr->events);
2267
2268 return file;
2269}
2270
2271/* Add an event to a trace directory */
2272static int
2273__trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2274{
2275 struct trace_event_file *file;
2276
2277 file = trace_create_new_event(call, tr);
2278 if (!file)
2279 return -ENOMEM;
2280
2281 return event_create_dir(tr->event_dir, file);
2282}
2283
2284/*
2285 * Just create a decriptor for early init. A descriptor is required
2286 * for enabling events at boot. We want to enable events before
2287 * the filesystem is initialized.
2288 */
2289static __init int
2290__trace_early_add_new_event(struct trace_event_call *call,
2291 struct trace_array *tr)
2292{
2293 struct trace_event_file *file;
2294
2295 file = trace_create_new_event(call, tr);
2296 if (!file)
2297 return -ENOMEM;
2298
2299 return 0;
2300}
2301
2302struct ftrace_module_file_ops;
2303static void __add_event_to_tracers(struct trace_event_call *call);
2304
2305/* Add an additional event_call dynamically */
2306int trace_add_event_call(struct trace_event_call *call)
2307{
2308 int ret;
2309 mutex_lock(&event_mutex);
2310 mutex_lock(&trace_types_lock);
2311
2312 ret = __register_event(call, NULL);
2313 if (ret >= 0)
2314 __add_event_to_tracers(call);
2315
2316 mutex_unlock(&trace_types_lock);
2317 mutex_unlock(&event_mutex);
2318 return ret;
2319}
2320
2321/*
2322 * Must be called under locking of trace_types_lock, event_mutex and
2323 * trace_event_sem.
2324 */
2325static void __trace_remove_event_call(struct trace_event_call *call)
2326{
2327 event_remove(call);
2328 trace_destroy_fields(call);
2329 free_event_filter(call->filter);
2330 call->filter = NULL;
2331}
2332
2333static int probe_remove_event_call(struct trace_event_call *call)
2334{
2335 struct trace_array *tr;
2336 struct trace_event_file *file;
2337
2338#ifdef CONFIG_PERF_EVENTS
2339 if (call->perf_refcount)
2340 return -EBUSY;
2341#endif
2342 do_for_each_event_file(tr, file) {
2343 if (file->event_call != call)
2344 continue;
2345 /*
2346 * We can't rely on ftrace_event_enable_disable(enable => 0)
2347 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2348 * TRACE_REG_UNREGISTER.
2349 */
2350 if (file->flags & EVENT_FILE_FL_ENABLED)
2351 return -EBUSY;
2352 /*
2353 * The do_for_each_event_file_safe() is
2354 * a double loop. After finding the call for this
2355 * trace_array, we use break to jump to the next
2356 * trace_array.
2357 */
2358 break;
2359 } while_for_each_event_file();
2360
2361 __trace_remove_event_call(call);
2362
2363 return 0;
2364}
2365
2366/* Remove an event_call */
2367int trace_remove_event_call(struct trace_event_call *call)
2368{
2369 int ret;
2370
2371 mutex_lock(&event_mutex);
2372 mutex_lock(&trace_types_lock);
2373 down_write(&trace_event_sem);
2374 ret = probe_remove_event_call(call);
2375 up_write(&trace_event_sem);
2376 mutex_unlock(&trace_types_lock);
2377 mutex_unlock(&event_mutex);
2378
2379 return ret;
2380}
2381
2382#define for_each_event(event, start, end) \
2383 for (event = start; \
2384 (unsigned long)event < (unsigned long)end; \
2385 event++)
2386
2387#ifdef CONFIG_MODULES
2388
2389static void trace_module_add_events(struct module *mod)
2390{
2391 struct trace_event_call **call, **start, **end;
2392
2393 if (!mod->num_trace_events)
2394 return;
2395
2396 /* Don't add infrastructure for mods without tracepoints */
2397 if (trace_module_has_bad_taint(mod)) {
2398 pr_err("%s: module has bad taint, not creating trace events\n",
2399 mod->name);
2400 return;
2401 }
2402
2403 start = mod->trace_events;
2404 end = mod->trace_events + mod->num_trace_events;
2405
2406 for_each_event(call, start, end) {
2407 __register_event(*call, mod);
2408 __add_event_to_tracers(*call);
2409 }
2410}
2411
2412static void trace_module_remove_events(struct module *mod)
2413{
2414 struct trace_event_call *call, *p;
2415
2416 down_write(&trace_event_sem);
2417 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2418 if (call->mod == mod)
2419 __trace_remove_event_call(call);
2420 }
2421 up_write(&trace_event_sem);
2422
2423 /*
2424 * It is safest to reset the ring buffer if the module being unloaded
2425 * registered any events that were used. The only worry is if
2426 * a new module gets loaded, and takes on the same id as the events
2427 * of this module. When printing out the buffer, traced events left
2428 * over from this module may be passed to the new module events and
2429 * unexpected results may occur.
2430 */
2431 tracing_reset_all_online_cpus();
2432}
2433
2434static int trace_module_notify(struct notifier_block *self,
2435 unsigned long val, void *data)
2436{
2437 struct module *mod = data;
2438
2439 mutex_lock(&event_mutex);
2440 mutex_lock(&trace_types_lock);
2441 switch (val) {
2442 case MODULE_STATE_COMING:
2443 trace_module_add_events(mod);
2444 break;
2445 case MODULE_STATE_GOING:
2446 trace_module_remove_events(mod);
2447 break;
2448 }
2449 mutex_unlock(&trace_types_lock);
2450 mutex_unlock(&event_mutex);
2451
2452 return 0;
2453}
2454
2455static struct notifier_block trace_module_nb = {
2456 .notifier_call = trace_module_notify,
2457 .priority = 1, /* higher than trace.c module notify */
2458};
2459#endif /* CONFIG_MODULES */
2460
2461/* Create a new event directory structure for a trace directory. */
2462static void
2463__trace_add_event_dirs(struct trace_array *tr)
2464{
2465 struct trace_event_call *call;
2466 int ret;
2467
2468 list_for_each_entry(call, &ftrace_events, list) {
2469 ret = __trace_add_new_event(call, tr);
2470 if (ret < 0)
2471 pr_warn("Could not create directory for event %s\n",
2472 trace_event_name(call));
2473 }
2474}
2475
2476struct trace_event_file *
2477find_event_file(struct trace_array *tr, const char *system, const char *event)
2478{
2479 struct trace_event_file *file;
2480 struct trace_event_call *call;
2481 const char *name;
2482
2483 list_for_each_entry(file, &tr->events, list) {
2484
2485 call = file->event_call;
2486 name = trace_event_name(call);
2487
2488 if (!name || !call->class || !call->class->reg)
2489 continue;
2490
2491 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2492 continue;
2493
2494 if (strcmp(event, name) == 0 &&
2495 strcmp(system, call->class->system) == 0)
2496 return file;
2497 }
2498 return NULL;
2499}
2500
2501#ifdef CONFIG_DYNAMIC_FTRACE
2502
2503/* Avoid typos */
2504#define ENABLE_EVENT_STR "enable_event"
2505#define DISABLE_EVENT_STR "disable_event"
2506
2507struct event_probe_data {
2508 struct trace_event_file *file;
2509 unsigned long count;
2510 int ref;
2511 bool enable;
2512};
2513
2514static void update_event_probe(struct event_probe_data *data)
2515{
2516 if (data->enable)
2517 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2518 else
2519 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2520}
2521
2522static void
2523event_enable_probe(unsigned long ip, unsigned long parent_ip,
2524 struct trace_array *tr, struct ftrace_probe_ops *ops,
2525 void *data)
2526{
2527 struct ftrace_func_mapper *mapper = data;
2528 struct event_probe_data *edata;
2529 void **pdata;
2530
2531 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2532 if (!pdata || !*pdata)
2533 return;
2534
2535 edata = *pdata;
2536 update_event_probe(edata);
2537}
2538
2539static void
2540event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
2541 struct trace_array *tr, struct ftrace_probe_ops *ops,
2542 void *data)
2543{
2544 struct ftrace_func_mapper *mapper = data;
2545 struct event_probe_data *edata;
2546 void **pdata;
2547
2548 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2549 if (!pdata || !*pdata)
2550 return;
2551
2552 edata = *pdata;
2553
2554 if (!edata->count)
2555 return;
2556
2557 /* Skip if the event is in a state we want to switch to */
2558 if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
2559 return;
2560
2561 if (edata->count != -1)
2562 (edata->count)--;
2563
2564 update_event_probe(edata);
2565}
2566
2567static int
2568event_enable_print(struct seq_file *m, unsigned long ip,
2569 struct ftrace_probe_ops *ops, void *data)
2570{
2571 struct ftrace_func_mapper *mapper = data;
2572 struct event_probe_data *edata;
2573 void **pdata;
2574
2575 pdata = ftrace_func_mapper_find_ip(mapper, ip);
2576
2577 if (WARN_ON_ONCE(!pdata || !*pdata))
2578 return 0;
2579
2580 edata = *pdata;
2581
2582 seq_printf(m, "%ps:", (void *)ip);
2583
2584 seq_printf(m, "%s:%s:%s",
2585 edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2586 edata->file->event_call->class->system,
2587 trace_event_name(edata->file->event_call));
2588
2589 if (edata->count == -1)
2590 seq_puts(m, ":unlimited\n");
2591 else
2592 seq_printf(m, ":count=%ld\n", edata->count);
2593
2594 return 0;
2595}
2596
2597static int
2598event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
2599 unsigned long ip, void *init_data, void **data)
2600{
2601 struct ftrace_func_mapper *mapper = *data;
2602 struct event_probe_data *edata = init_data;
2603 int ret;
2604
2605 if (!mapper) {
2606 mapper = allocate_ftrace_func_mapper();
2607 if (!mapper)
2608 return -ENODEV;
2609 *data = mapper;
2610 }
2611
2612 ret = ftrace_func_mapper_add_ip(mapper, ip, edata);
2613 if (ret < 0)
2614 return ret;
2615
2616 edata->ref++;
2617
2618 return 0;
2619}
2620
2621static int free_probe_data(void *data)
2622{
2623 struct event_probe_data *edata = data;
2624
2625 edata->ref--;
2626 if (!edata->ref) {
2627 /* Remove the SOFT_MODE flag */
2628 __ftrace_event_enable_disable(edata->file, 0, 1);
2629 module_put(edata->file->event_call->mod);
2630 kfree(edata);
2631 }
2632 return 0;
2633}
2634
2635static void
2636event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
2637 unsigned long ip, void *data)
2638{
2639 struct ftrace_func_mapper *mapper = data;
2640 struct event_probe_data *edata;
2641
2642 if (!ip) {
2643 if (!mapper)
2644 return;
2645 free_ftrace_func_mapper(mapper, free_probe_data);
2646 return;
2647 }
2648
2649 edata = ftrace_func_mapper_remove_ip(mapper, ip);
2650
2651 if (WARN_ON_ONCE(!edata))
2652 return;
2653
2654 if (WARN_ON_ONCE(edata->ref <= 0))
2655 return;
2656
2657 free_probe_data(edata);
2658}
2659
2660static struct ftrace_probe_ops event_enable_probe_ops = {
2661 .func = event_enable_probe,
2662 .print = event_enable_print,
2663 .init = event_enable_init,
2664 .free = event_enable_free,
2665};
2666
2667static struct ftrace_probe_ops event_enable_count_probe_ops = {
2668 .func = event_enable_count_probe,
2669 .print = event_enable_print,
2670 .init = event_enable_init,
2671 .free = event_enable_free,
2672};
2673
2674static struct ftrace_probe_ops event_disable_probe_ops = {
2675 .func = event_enable_probe,
2676 .print = event_enable_print,
2677 .init = event_enable_init,
2678 .free = event_enable_free,
2679};
2680
2681static struct ftrace_probe_ops event_disable_count_probe_ops = {
2682 .func = event_enable_count_probe,
2683 .print = event_enable_print,
2684 .init = event_enable_init,
2685 .free = event_enable_free,
2686};
2687
2688static int
2689event_enable_func(struct trace_array *tr, struct ftrace_hash *hash,
2690 char *glob, char *cmd, char *param, int enabled)
2691{
2692 struct trace_event_file *file;
2693 struct ftrace_probe_ops *ops;
2694 struct event_probe_data *data;
2695 const char *system;
2696 const char *event;
2697 char *number;
2698 bool enable;
2699 int ret;
2700
2701 if (!tr)
2702 return -ENODEV;
2703
2704 /* hash funcs only work with set_ftrace_filter */
2705 if (!enabled || !param)
2706 return -EINVAL;
2707
2708 system = strsep(¶m, ":");
2709 if (!param)
2710 return -EINVAL;
2711
2712 event = strsep(¶m, ":");
2713
2714 mutex_lock(&event_mutex);
2715
2716 ret = -EINVAL;
2717 file = find_event_file(tr, system, event);
2718 if (!file)
2719 goto out;
2720
2721 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2722
2723 if (enable)
2724 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2725 else
2726 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2727
2728 if (glob[0] == '!') {
2729 ret = unregister_ftrace_function_probe_func(glob+1, tr, ops);
2730 goto out;
2731 }
2732
2733 ret = -ENOMEM;
2734
2735 data = kzalloc(sizeof(*data), GFP_KERNEL);
2736 if (!data)
2737 goto out;
2738
2739 data->enable = enable;
2740 data->count = -1;
2741 data->file = file;
2742
2743 if (!param)
2744 goto out_reg;
2745
2746 number = strsep(¶m, ":");
2747
2748 ret = -EINVAL;
2749 if (!strlen(number))
2750 goto out_free;
2751
2752 /*
2753 * We use the callback data field (which is a pointer)
2754 * as our counter.
2755 */
2756 ret = kstrtoul(number, 0, &data->count);
2757 if (ret)
2758 goto out_free;
2759
2760 out_reg:
2761 /* Don't let event modules unload while probe registered */
2762 ret = try_module_get(file->event_call->mod);
2763 if (!ret) {
2764 ret = -EBUSY;
2765 goto out_free;
2766 }
2767
2768 ret = __ftrace_event_enable_disable(file, 1, 1);
2769 if (ret < 0)
2770 goto out_put;
2771
2772 ret = register_ftrace_function_probe(glob, tr, ops, data);
2773 /*
2774 * The above returns on success the # of functions enabled,
2775 * but if it didn't find any functions it returns zero.
2776 * Consider no functions a failure too.
2777 */
2778 if (!ret) {
2779 ret = -ENOENT;
2780 goto out_disable;
2781 } else if (ret < 0)
2782 goto out_disable;
2783 /* Just return zero, not the number of enabled functions */
2784 ret = 0;
2785 out:
2786 mutex_unlock(&event_mutex);
2787 return ret;
2788
2789 out_disable:
2790 __ftrace_event_enable_disable(file, 0, 1);
2791 out_put:
2792 module_put(file->event_call->mod);
2793 out_free:
2794 kfree(data);
2795 goto out;
2796}
2797
2798static struct ftrace_func_command event_enable_cmd = {
2799 .name = ENABLE_EVENT_STR,
2800 .func = event_enable_func,
2801};
2802
2803static struct ftrace_func_command event_disable_cmd = {
2804 .name = DISABLE_EVENT_STR,
2805 .func = event_enable_func,
2806};
2807
2808static __init int register_event_cmds(void)
2809{
2810 int ret;
2811
2812 ret = register_ftrace_command(&event_enable_cmd);
2813 if (WARN_ON(ret < 0))
2814 return ret;
2815 ret = register_ftrace_command(&event_disable_cmd);
2816 if (WARN_ON(ret < 0))
2817 unregister_ftrace_command(&event_enable_cmd);
2818 return ret;
2819}
2820#else
2821static inline int register_event_cmds(void) { return 0; }
2822#endif /* CONFIG_DYNAMIC_FTRACE */
2823
2824/*
2825 * The top level array has already had its trace_event_file
2826 * descriptors created in order to allow for early events to
2827 * be recorded. This function is called after the tracefs has been
2828 * initialized, and we now have to create the files associated
2829 * to the events.
2830 */
2831static __init void
2832__trace_early_add_event_dirs(struct trace_array *tr)
2833{
2834 struct trace_event_file *file;
2835 int ret;
2836
2837
2838 list_for_each_entry(file, &tr->events, list) {
2839 ret = event_create_dir(tr->event_dir, file);
2840 if (ret < 0)
2841 pr_warn("Could not create directory for event %s\n",
2842 trace_event_name(file->event_call));
2843 }
2844}
2845
2846/*
2847 * For early boot up, the top trace array requires to have
2848 * a list of events that can be enabled. This must be done before
2849 * the filesystem is set up in order to allow events to be traced
2850 * early.
2851 */
2852static __init void
2853__trace_early_add_events(struct trace_array *tr)
2854{
2855 struct trace_event_call *call;
2856 int ret;
2857
2858 list_for_each_entry(call, &ftrace_events, list) {
2859 /* Early boot up should not have any modules loaded */
2860 if (WARN_ON_ONCE(call->mod))
2861 continue;
2862
2863 ret = __trace_early_add_new_event(call, tr);
2864 if (ret < 0)
2865 pr_warn("Could not create early event %s\n",
2866 trace_event_name(call));
2867 }
2868}
2869
2870/* Remove the event directory structure for a trace directory. */
2871static void
2872__trace_remove_event_dirs(struct trace_array *tr)
2873{
2874 struct trace_event_file *file, *next;
2875
2876 list_for_each_entry_safe(file, next, &tr->events, list)
2877 remove_event_file_dir(file);
2878}
2879
2880static void __add_event_to_tracers(struct trace_event_call *call)
2881{
2882 struct trace_array *tr;
2883
2884 list_for_each_entry(tr, &ftrace_trace_arrays, list)
2885 __trace_add_new_event(call, tr);
2886}
2887
2888extern struct trace_event_call *__start_ftrace_events[];
2889extern struct trace_event_call *__stop_ftrace_events[];
2890
2891static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2892
2893static __init int setup_trace_event(char *str)
2894{
2895 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2896 ring_buffer_expanded = true;
2897 tracing_selftest_disabled = true;
2898
2899 return 1;
2900}
2901__setup("trace_event=", setup_trace_event);
2902
2903/* Expects to have event_mutex held when called */
2904static int
2905create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2906{
2907 struct dentry *d_events;
2908 struct dentry *entry;
2909
2910 entry = tracefs_create_file("set_event", 0644, parent,
2911 tr, &ftrace_set_event_fops);
2912 if (!entry) {
2913 pr_warn("Could not create tracefs 'set_event' entry\n");
2914 return -ENOMEM;
2915 }
2916
2917 d_events = tracefs_create_dir("events", parent);
2918 if (!d_events) {
2919 pr_warn("Could not create tracefs 'events' directory\n");
2920 return -ENOMEM;
2921 }
2922
2923 entry = trace_create_file("enable", 0644, d_events,
2924 tr, &ftrace_tr_enable_fops);
2925 if (!entry) {
2926 pr_warn("Could not create tracefs 'enable' entry\n");
2927 return -ENOMEM;
2928 }
2929
2930 /* There are not as crucial, just warn if they are not created */
2931
2932 entry = tracefs_create_file("set_event_pid", 0644, parent,
2933 tr, &ftrace_set_event_pid_fops);
2934 if (!entry)
2935 pr_warn("Could not create tracefs 'set_event_pid' entry\n");
2936
2937 /* ring buffer internal formats */
2938 entry = trace_create_file("header_page", 0444, d_events,
2939 ring_buffer_print_page_header,
2940 &ftrace_show_header_fops);
2941 if (!entry)
2942 pr_warn("Could not create tracefs 'header_page' entry\n");
2943
2944 entry = trace_create_file("header_event", 0444, d_events,
2945 ring_buffer_print_entry_header,
2946 &ftrace_show_header_fops);
2947 if (!entry)
2948 pr_warn("Could not create tracefs 'header_event' entry\n");
2949
2950 tr->event_dir = d_events;
2951
2952 return 0;
2953}
2954
2955/**
2956 * event_trace_add_tracer - add a instance of a trace_array to events
2957 * @parent: The parent dentry to place the files/directories for events in
2958 * @tr: The trace array associated with these events
2959 *
2960 * When a new instance is created, it needs to set up its events
2961 * directory, as well as other files associated with events. It also
2962 * creates the event hierachry in the @parent/events directory.
2963 *
2964 * Returns 0 on success.
2965 *
2966 * Must be called with event_mutex held.
2967 */
2968int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2969{
2970 int ret;
2971
2972 lockdep_assert_held(&event_mutex);
2973
2974 ret = create_event_toplevel_files(parent, tr);
2975 if (ret)
2976 goto out;
2977
2978 down_write(&trace_event_sem);
2979 __trace_add_event_dirs(tr);
2980 up_write(&trace_event_sem);
2981
2982 out:
2983 return ret;
2984}
2985
2986/*
2987 * The top trace array already had its file descriptors created.
2988 * Now the files themselves need to be created.
2989 */
2990static __init int
2991early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2992{
2993 int ret;
2994
2995 mutex_lock(&event_mutex);
2996
2997 ret = create_event_toplevel_files(parent, tr);
2998 if (ret)
2999 goto out_unlock;
3000
3001 down_write(&trace_event_sem);
3002 __trace_early_add_event_dirs(tr);
3003 up_write(&trace_event_sem);
3004
3005 out_unlock:
3006 mutex_unlock(&event_mutex);
3007
3008 return ret;
3009}
3010
3011/* Must be called with event_mutex held */
3012int event_trace_del_tracer(struct trace_array *tr)
3013{
3014 lockdep_assert_held(&event_mutex);
3015
3016 /* Disable any event triggers and associated soft-disabled events */
3017 clear_event_triggers(tr);
3018
3019 /* Clear the pid list */
3020 __ftrace_clear_event_pids(tr);
3021
3022 /* Disable any running events */
3023 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3024
3025 /* Access to events are within rcu_read_lock_sched() */
3026 synchronize_sched();
3027
3028 down_write(&trace_event_sem);
3029 __trace_remove_event_dirs(tr);
3030 tracefs_remove_recursive(tr->event_dir);
3031 up_write(&trace_event_sem);
3032
3033 tr->event_dir = NULL;
3034
3035 return 0;
3036}
3037
3038static __init int event_trace_memsetup(void)
3039{
3040 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3041 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3042 return 0;
3043}
3044
3045static __init void
3046early_enable_events(struct trace_array *tr, bool disable_first)
3047{
3048 char *buf = bootup_event_buf;
3049 char *token;
3050 int ret;
3051
3052 while (true) {
3053 token = strsep(&buf, ",");
3054
3055 if (!token)
3056 break;
3057
3058 if (*token) {
3059 /* Restarting syscalls requires that we stop them first */
3060 if (disable_first)
3061 ftrace_set_clr_event(tr, token, 0);
3062
3063 ret = ftrace_set_clr_event(tr, token, 1);
3064 if (ret)
3065 pr_warn("Failed to enable trace event: %s\n", token);
3066 }
3067
3068 /* Put back the comma to allow this to be called again */
3069 if (buf)
3070 *(buf - 1) = ',';
3071 }
3072}
3073
3074static __init int event_trace_enable(void)
3075{
3076 struct trace_array *tr = top_trace_array();
3077 struct trace_event_call **iter, *call;
3078 int ret;
3079
3080 if (!tr)
3081 return -ENODEV;
3082
3083 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3084
3085 call = *iter;
3086 ret = event_init(call);
3087 if (!ret)
3088 list_add(&call->list, &ftrace_events);
3089 }
3090
3091 /*
3092 * We need the top trace array to have a working set of trace
3093 * points at early init, before the debug files and directories
3094 * are created. Create the file entries now, and attach them
3095 * to the actual file dentries later.
3096 */
3097 __trace_early_add_events(tr);
3098
3099 early_enable_events(tr, false);
3100
3101 trace_printk_start_comm();
3102
3103 register_event_cmds();
3104
3105 register_trigger_cmds();
3106
3107 return 0;
3108}
3109
3110/*
3111 * event_trace_enable() is called from trace_event_init() first to
3112 * initialize events and perhaps start any events that are on the
3113 * command line. Unfortunately, there are some events that will not
3114 * start this early, like the system call tracepoints that need
3115 * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
3116 * is called before pid 1 starts, and this flag is never set, making
3117 * the syscall tracepoint never get reached, but the event is enabled
3118 * regardless (and not doing anything).
3119 */
3120static __init int event_trace_enable_again(void)
3121{
3122 struct trace_array *tr;
3123
3124 tr = top_trace_array();
3125 if (!tr)
3126 return -ENODEV;
3127
3128 early_enable_events(tr, true);
3129
3130 return 0;
3131}
3132
3133early_initcall(event_trace_enable_again);
3134
3135static __init int event_trace_init(void)
3136{
3137 struct trace_array *tr;
3138 struct dentry *d_tracer;
3139 struct dentry *entry;
3140 int ret;
3141
3142 tr = top_trace_array();
3143 if (!tr)
3144 return -ENODEV;
3145
3146 d_tracer = tracing_init_dentry();
3147 if (IS_ERR(d_tracer))
3148 return 0;
3149
3150 entry = tracefs_create_file("available_events", 0444, d_tracer,
3151 tr, &ftrace_avail_fops);
3152 if (!entry)
3153 pr_warn("Could not create tracefs 'available_events' entry\n");
3154
3155 if (trace_define_generic_fields())
3156 pr_warn("tracing: Failed to allocated generic fields");
3157
3158 if (trace_define_common_fields())
3159 pr_warn("tracing: Failed to allocate common fields");
3160
3161 ret = early_event_add_tracer(d_tracer, tr);
3162 if (ret)
3163 return ret;
3164
3165#ifdef CONFIG_MODULES
3166 ret = register_module_notifier(&trace_module_nb);
3167 if (ret)
3168 pr_warn("Failed to register trace events module notifier\n");
3169#endif
3170 return 0;
3171}
3172
3173void __init trace_event_init(void)
3174{
3175 event_trace_memsetup();
3176 init_ftrace_syscalls();
3177 event_trace_enable();
3178}
3179
3180fs_initcall(event_trace_init);
3181
3182#ifdef CONFIG_FTRACE_STARTUP_TEST
3183
3184static DEFINE_SPINLOCK(test_spinlock);
3185static DEFINE_SPINLOCK(test_spinlock_irq);
3186static DEFINE_MUTEX(test_mutex);
3187
3188static __init void test_work(struct work_struct *dummy)
3189{
3190 spin_lock(&test_spinlock);
3191 spin_lock_irq(&test_spinlock_irq);
3192 udelay(1);
3193 spin_unlock_irq(&test_spinlock_irq);
3194 spin_unlock(&test_spinlock);
3195
3196 mutex_lock(&test_mutex);
3197 msleep(1);
3198 mutex_unlock(&test_mutex);
3199}
3200
3201static __init int event_test_thread(void *unused)
3202{
3203 void *test_malloc;
3204
3205 test_malloc = kmalloc(1234, GFP_KERNEL);
3206 if (!test_malloc)
3207 pr_info("failed to kmalloc\n");
3208
3209 schedule_on_each_cpu(test_work);
3210
3211 kfree(test_malloc);
3212
3213 set_current_state(TASK_INTERRUPTIBLE);
3214 while (!kthread_should_stop()) {
3215 schedule();
3216 set_current_state(TASK_INTERRUPTIBLE);
3217 }
3218 __set_current_state(TASK_RUNNING);
3219
3220 return 0;
3221}
3222
3223/*
3224 * Do various things that may trigger events.
3225 */
3226static __init void event_test_stuff(void)
3227{
3228 struct task_struct *test_thread;
3229
3230 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3231 msleep(1);
3232 kthread_stop(test_thread);
3233}
3234
3235/*
3236 * For every trace event defined, we will test each trace point separately,
3237 * and then by groups, and finally all trace points.
3238 */
3239static __init void event_trace_self_tests(void)
3240{
3241 struct trace_subsystem_dir *dir;
3242 struct trace_event_file *file;
3243 struct trace_event_call *call;
3244 struct event_subsystem *system;
3245 struct trace_array *tr;
3246 int ret;
3247
3248 tr = top_trace_array();
3249 if (!tr)
3250 return;
3251
3252 pr_info("Running tests on trace events:\n");
3253
3254 list_for_each_entry(file, &tr->events, list) {
3255
3256 call = file->event_call;
3257
3258 /* Only test those that have a probe */
3259 if (!call->class || !call->class->probe)
3260 continue;
3261
3262/*
3263 * Testing syscall events here is pretty useless, but
3264 * we still do it if configured. But this is time consuming.
3265 * What we really need is a user thread to perform the
3266 * syscalls as we test.
3267 */
3268#ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3269 if (call->class->system &&
3270 strcmp(call->class->system, "syscalls") == 0)
3271 continue;
3272#endif
3273
3274 pr_info("Testing event %s: ", trace_event_name(call));
3275
3276 /*
3277 * If an event is already enabled, someone is using
3278 * it and the self test should not be on.
3279 */
3280 if (file->flags & EVENT_FILE_FL_ENABLED) {
3281 pr_warn("Enabled event during self test!\n");
3282 WARN_ON_ONCE(1);
3283 continue;
3284 }
3285
3286 ftrace_event_enable_disable(file, 1);
3287 event_test_stuff();
3288 ftrace_event_enable_disable(file, 0);
3289
3290 pr_cont("OK\n");
3291 }
3292
3293 /* Now test at the sub system level */
3294
3295 pr_info("Running tests on trace event systems:\n");
3296
3297 list_for_each_entry(dir, &tr->systems, list) {
3298
3299 system = dir->subsystem;
3300
3301 /* the ftrace system is special, skip it */
3302 if (strcmp(system->name, "ftrace") == 0)
3303 continue;
3304
3305 pr_info("Testing event system %s: ", system->name);
3306
3307 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3308 if (WARN_ON_ONCE(ret)) {
3309 pr_warn("error enabling system %s\n",
3310 system->name);
3311 continue;
3312 }
3313
3314 event_test_stuff();
3315
3316 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3317 if (WARN_ON_ONCE(ret)) {
3318 pr_warn("error disabling system %s\n",
3319 system->name);
3320 continue;
3321 }
3322
3323 pr_cont("OK\n");
3324 }
3325
3326 /* Test with all events enabled */
3327
3328 pr_info("Running tests on all trace events:\n");
3329 pr_info("Testing all events: ");
3330
3331 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3332 if (WARN_ON_ONCE(ret)) {
3333 pr_warn("error enabling all events\n");
3334 return;
3335 }
3336
3337 event_test_stuff();
3338
3339 /* reset sysname */
3340 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3341 if (WARN_ON_ONCE(ret)) {
3342 pr_warn("error disabling all events\n");
3343 return;
3344 }
3345
3346 pr_cont("OK\n");
3347}
3348
3349#ifdef CONFIG_FUNCTION_TRACER
3350
3351static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3352
3353static struct trace_event_file event_trace_file __initdata;
3354
3355static void __init
3356function_test_events_call(unsigned long ip, unsigned long parent_ip,
3357 struct ftrace_ops *op, struct pt_regs *pt_regs)
3358{
3359 struct ring_buffer_event *event;
3360 struct ring_buffer *buffer;
3361 struct ftrace_entry *entry;
3362 unsigned long flags;
3363 long disabled;
3364 int cpu;
3365 int pc;
3366
3367 pc = preempt_count();
3368 preempt_disable_notrace();
3369 cpu = raw_smp_processor_id();
3370 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3371
3372 if (disabled != 1)
3373 goto out;
3374
3375 local_save_flags(flags);
3376
3377 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
3378 TRACE_FN, sizeof(*entry),
3379 flags, pc);
3380 if (!event)
3381 goto out;
3382 entry = ring_buffer_event_data(event);
3383 entry->ip = ip;
3384 entry->parent_ip = parent_ip;
3385
3386 event_trigger_unlock_commit(&event_trace_file, buffer, event,
3387 entry, flags, pc);
3388 out:
3389 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3390 preempt_enable_notrace();
3391}
3392
3393static struct ftrace_ops trace_ops __initdata =
3394{
3395 .func = function_test_events_call,
3396 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
3397};
3398
3399static __init void event_trace_self_test_with_function(void)
3400{
3401 int ret;
3402
3403 event_trace_file.tr = top_trace_array();
3404 if (WARN_ON(!event_trace_file.tr))
3405 return;
3406
3407 ret = register_ftrace_function(&trace_ops);
3408 if (WARN_ON(ret < 0)) {
3409 pr_info("Failed to enable function tracer for event tests\n");
3410 return;
3411 }
3412 pr_info("Running tests again, along with the function tracer\n");
3413 event_trace_self_tests();
3414 unregister_ftrace_function(&trace_ops);
3415}
3416#else
3417static __init void event_trace_self_test_with_function(void)
3418{
3419}
3420#endif
3421
3422static __init int event_trace_self_tests_init(void)
3423{
3424 if (!tracing_selftest_disabled) {
3425 event_trace_self_tests();
3426 event_trace_self_test_with_function();
3427 }
3428
3429 return 0;
3430}
3431
3432late_initcall(event_trace_self_tests_init);
3433
3434#endif