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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// 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, const 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 int need_test)
119{
120 struct ftrace_event_field *field;
121
122 field = kmem_cache_alloc(field_cachep, GFP_TRACE);
123 if (!field)
124 return -ENOMEM;
125
126 field->name = name;
127 field->type = type;
128
129 if (filter_type == FILTER_OTHER)
130 field->filter_type = filter_assign_type(type);
131 else
132 field->filter_type = filter_type;
133
134 field->offset = offset;
135 field->size = size;
136 field->is_signed = is_signed;
137 field->needs_test = need_test;
138 field->len = len;
139
140 list_add(&field->link, head);
141
142 return 0;
143}
144
145int trace_define_field(struct trace_event_call *call, const char *type,
146 const char *name, int offset, int size, int is_signed,
147 int filter_type)
148{
149 struct list_head *head;
150
151 if (WARN_ON(!call->class))
152 return 0;
153
154 head = trace_get_fields(call);
155 return __trace_define_field(head, type, name, offset, size,
156 is_signed, filter_type, 0, 0);
157}
158EXPORT_SYMBOL_GPL(trace_define_field);
159
160static int trace_define_field_ext(struct trace_event_call *call, const char *type,
161 const char *name, int offset, int size, int is_signed,
162 int filter_type, int len, int need_test)
163{
164 struct list_head *head;
165
166 if (WARN_ON(!call->class))
167 return 0;
168
169 head = trace_get_fields(call);
170 return __trace_define_field(head, type, name, offset, size,
171 is_signed, filter_type, len, need_test);
172}
173
174#define __generic_field(type, item, filter_type) \
175 ret = __trace_define_field(&ftrace_generic_fields, #type, \
176 #item, 0, 0, is_signed_type(type), \
177 filter_type, 0, 0); \
178 if (ret) \
179 return ret;
180
181#define __common_field(type, item) \
182 ret = __trace_define_field(&ftrace_common_fields, #type, \
183 "common_" #item, \
184 offsetof(typeof(ent), item), \
185 sizeof(ent.item), \
186 is_signed_type(type), FILTER_OTHER, \
187 0, 0); \
188 if (ret) \
189 return ret;
190
191static int trace_define_generic_fields(void)
192{
193 int ret;
194
195 __generic_field(int, CPU, FILTER_CPU);
196 __generic_field(int, cpu, FILTER_CPU);
197 __generic_field(int, common_cpu, FILTER_CPU);
198 __generic_field(char *, COMM, FILTER_COMM);
199 __generic_field(char *, comm, FILTER_COMM);
200 __generic_field(char *, stacktrace, FILTER_STACKTRACE);
201 __generic_field(char *, STACKTRACE, FILTER_STACKTRACE);
202
203 return ret;
204}
205
206static int trace_define_common_fields(void)
207{
208 int ret;
209 struct trace_entry ent;
210
211 __common_field(unsigned short, type);
212 __common_field(unsigned char, flags);
213 /* Holds both preempt_count and migrate_disable */
214 __common_field(unsigned char, preempt_count);
215 __common_field(int, pid);
216
217 return ret;
218}
219
220static void trace_destroy_fields(struct trace_event_call *call)
221{
222 struct ftrace_event_field *field, *next;
223 struct list_head *head;
224
225 head = trace_get_fields(call);
226 list_for_each_entry_safe(field, next, head, link) {
227 list_del(&field->link);
228 kmem_cache_free(field_cachep, field);
229 }
230}
231
232/*
233 * run-time version of trace_event_get_offsets_<call>() that returns the last
234 * accessible offset of trace fields excluding __dynamic_array bytes
235 */
236int trace_event_get_offsets(struct trace_event_call *call)
237{
238 struct ftrace_event_field *tail;
239 struct list_head *head;
240
241 head = trace_get_fields(call);
242 /*
243 * head->next points to the last field with the largest offset,
244 * since it was added last by trace_define_field()
245 */
246 tail = list_first_entry(head, struct ftrace_event_field, link);
247 return tail->offset + tail->size;
248}
249
250
251static struct trace_event_fields *find_event_field(const char *fmt,
252 struct trace_event_call *call)
253{
254 struct trace_event_fields *field = call->class->fields_array;
255 const char *p = fmt;
256 int len;
257
258 if (!(len = str_has_prefix(fmt, "REC->")))
259 return NULL;
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) || field->name[len])
269 continue;
270
271 return field;
272 }
273 return NULL;
274}
275
276/*
277 * Check if the referenced field is an array and return true,
278 * as arrays are OK to dereference.
279 */
280static bool test_field(const char *fmt, struct trace_event_call *call)
281{
282 struct trace_event_fields *field;
283
284 field = find_event_field(fmt, call);
285 if (!field)
286 return false;
287
288 /* This is an array and is OK to dereference. */
289 return strchr(field->type, '[') != NULL;
290}
291
292/* Look for a string within an argument */
293static bool find_print_string(const char *arg, const char *str, const char *end)
294{
295 const char *r;
296
297 r = strstr(arg, str);
298 return r && r < end;
299}
300
301/* Return true if the argument pointer is safe */
302static bool process_pointer(const char *fmt, int len, struct trace_event_call *call)
303{
304 const char *r, *e, *a;
305
306 e = fmt + len;
307
308 /* Find the REC-> in the argument */
309 r = strstr(fmt, "REC->");
310 if (r && r < e) {
311 /*
312 * Addresses of events on the buffer, or an array on the buffer is
313 * OK to dereference. There's ways to fool this, but
314 * this is to catch common mistakes, not malicious code.
315 */
316 a = strchr(fmt, '&');
317 if ((a && (a < r)) || test_field(r, call))
318 return true;
319 } else if (find_print_string(fmt, "__get_dynamic_array(", e)) {
320 return true;
321 } else if (find_print_string(fmt, "__get_rel_dynamic_array(", e)) {
322 return true;
323 } else if (find_print_string(fmt, "__get_dynamic_array_len(", e)) {
324 return true;
325 } else if (find_print_string(fmt, "__get_rel_dynamic_array_len(", e)) {
326 return true;
327 } else if (find_print_string(fmt, "__get_sockaddr(", e)) {
328 return true;
329 } else if (find_print_string(fmt, "__get_rel_sockaddr(", e)) {
330 return true;
331 }
332 return false;
333}
334
335/* Return true if the string is safe */
336static bool process_string(const char *fmt, int len, struct trace_event_call *call)
337{
338 struct trace_event_fields *field;
339 const char *r, *e, *s;
340
341 e = fmt + len;
342
343 /*
344 * There are several helper functions that return strings.
345 * If the argument contains a function, then assume its field is valid.
346 * It is considered that the argument has a function if it has:
347 * alphanumeric or '_' before a parenthesis.
348 */
349 s = fmt;
350 do {
351 r = strstr(s, "(");
352 if (!r || r >= e)
353 break;
354 for (int i = 1; r - i >= s; i++) {
355 char ch = *(r - i);
356 if (isspace(ch))
357 continue;
358 if (isalnum(ch) || ch == '_')
359 return true;
360 /* Anything else, this isn't a function */
361 break;
362 }
363 /* A function could be wrapped in parethesis, try the next one */
364 s = r + 1;
365 } while (s < e);
366
367 /*
368 * Check for arrays. If the argument has: foo[REC->val]
369 * then it is very likely that foo is an array of strings
370 * that are safe to use.
371 */
372 r = strstr(s, "[");
373 if (r && r < e) {
374 r = strstr(r, "REC->");
375 if (r && r < e)
376 return true;
377 }
378
379 /*
380 * If there's any strings in the argument consider this arg OK as it
381 * could be: REC->field ? "foo" : "bar" and we don't want to get into
382 * verifying that logic here.
383 */
384 if (find_print_string(fmt, "\"", e))
385 return true;
386
387 /* Dereferenced strings are also valid like any other pointer */
388 if (process_pointer(fmt, len, call))
389 return true;
390
391 /* Make sure the field is found */
392 field = find_event_field(fmt, call);
393 if (!field)
394 return false;
395
396 /* Test this field's string before printing the event */
397 call->flags |= TRACE_EVENT_FL_TEST_STR;
398 field->needs_test = 1;
399
400 return true;
401}
402
403/*
404 * Examine the print fmt of the event looking for unsafe dereference
405 * pointers using %p* that could be recorded in the trace event and
406 * much later referenced after the pointer was freed. Dereferencing
407 * pointers are OK, if it is dereferenced into the event itself.
408 */
409static void test_event_printk(struct trace_event_call *call)
410{
411 u64 dereference_flags = 0;
412 u64 string_flags = 0;
413 bool first = true;
414 const char *fmt;
415 int parens = 0;
416 char in_quote = 0;
417 int start_arg = 0;
418 int arg = 0;
419 int i, e;
420
421 fmt = call->print_fmt;
422
423 if (!fmt)
424 return;
425
426 for (i = 0; fmt[i]; i++) {
427 switch (fmt[i]) {
428 case '\\':
429 i++;
430 if (!fmt[i])
431 return;
432 continue;
433 case '"':
434 case '\'':
435 /*
436 * The print fmt starts with a string that
437 * is processed first to find %p* usage,
438 * then after the first string, the print fmt
439 * contains arguments that are used to check
440 * if the dereferenced %p* usage is safe.
441 */
442 if (first) {
443 if (fmt[i] == '\'')
444 continue;
445 if (in_quote) {
446 arg = 0;
447 first = false;
448 /*
449 * If there was no %p* uses
450 * the fmt is OK.
451 */
452 if (!dereference_flags)
453 return;
454 }
455 }
456 if (in_quote) {
457 if (in_quote == fmt[i])
458 in_quote = 0;
459 } else {
460 in_quote = fmt[i];
461 }
462 continue;
463 case '%':
464 if (!first || !in_quote)
465 continue;
466 i++;
467 if (!fmt[i])
468 return;
469 switch (fmt[i]) {
470 case '%':
471 continue;
472 case 'p':
473 /* Find dereferencing fields */
474 switch (fmt[i + 1]) {
475 case 'B': case 'R': case 'r':
476 case 'b': case 'M': case 'm':
477 case 'I': case 'i': case 'E':
478 case 'U': case 'V': case 'N':
479 case 'a': case 'd': case 'D':
480 case 'g': case 't': case 'C':
481 case 'O': case 'f':
482 if (WARN_ONCE(arg == 63,
483 "Too many args for event: %s",
484 trace_event_name(call)))
485 return;
486 dereference_flags |= 1ULL << arg;
487 }
488 break;
489 default:
490 {
491 bool star = false;
492 int j;
493
494 /* Increment arg if %*s exists. */
495 for (j = 0; fmt[i + j]; j++) {
496 if (isdigit(fmt[i + j]) ||
497 fmt[i + j] == '.')
498 continue;
499 if (fmt[i + j] == '*') {
500 star = true;
501 continue;
502 }
503 if ((fmt[i + j] == 's')) {
504 if (star)
505 arg++;
506 if (WARN_ONCE(arg == 63,
507 "Too many args for event: %s",
508 trace_event_name(call)))
509 return;
510 dereference_flags |= 1ULL << arg;
511 string_flags |= 1ULL << arg;
512 }
513 break;
514 }
515 break;
516 } /* default */
517
518 } /* switch */
519 arg++;
520 continue;
521 case '(':
522 if (in_quote)
523 continue;
524 parens++;
525 continue;
526 case ')':
527 if (in_quote)
528 continue;
529 parens--;
530 if (WARN_ONCE(parens < 0,
531 "Paren mismatch for event: %s\narg='%s'\n%*s",
532 trace_event_name(call),
533 fmt + start_arg,
534 (i - start_arg) + 5, "^"))
535 return;
536 continue;
537 case ',':
538 if (in_quote || parens)
539 continue;
540 e = i;
541 i++;
542 while (isspace(fmt[i]))
543 i++;
544
545 /*
546 * If start_arg is zero, then this is the start of the
547 * first argument. The processing of the argument happens
548 * when the end of the argument is found, as it needs to
549 * handle paranthesis and such.
550 */
551 if (!start_arg) {
552 start_arg = i;
553 /* Balance out the i++ in the for loop */
554 i--;
555 continue;
556 }
557
558 if (dereference_flags & (1ULL << arg)) {
559 if (string_flags & (1ULL << arg)) {
560 if (process_string(fmt + start_arg, e - start_arg, call))
561 dereference_flags &= ~(1ULL << arg);
562 } else if (process_pointer(fmt + start_arg, e - start_arg, call))
563 dereference_flags &= ~(1ULL << arg);
564 }
565
566 start_arg = i;
567 arg++;
568 /* Balance out the i++ in the for loop */
569 i--;
570 }
571 }
572
573 if (dereference_flags & (1ULL << arg)) {
574 if (string_flags & (1ULL << arg)) {
575 if (process_string(fmt + start_arg, i - start_arg, call))
576 dereference_flags &= ~(1ULL << arg);
577 } else if (process_pointer(fmt + start_arg, i - start_arg, call))
578 dereference_flags &= ~(1ULL << arg);
579 }
580
581 /*
582 * If you triggered the below warning, the trace event reported
583 * uses an unsafe dereference pointer %p*. As the data stored
584 * at the trace event time may no longer exist when the trace
585 * event is printed, dereferencing to the original source is
586 * unsafe. The source of the dereference must be copied into the
587 * event itself, and the dereference must access the copy instead.
588 */
589 if (WARN_ON_ONCE(dereference_flags)) {
590 arg = 1;
591 while (!(dereference_flags & 1)) {
592 dereference_flags >>= 1;
593 arg++;
594 }
595 pr_warn("event %s has unsafe dereference of argument %d\n",
596 trace_event_name(call), arg);
597 pr_warn("print_fmt: %s\n", fmt);
598 }
599}
600
601int trace_event_raw_init(struct trace_event_call *call)
602{
603 int id;
604
605 id = register_trace_event(&call->event);
606 if (!id)
607 return -ENODEV;
608
609 test_event_printk(call);
610
611 return 0;
612}
613EXPORT_SYMBOL_GPL(trace_event_raw_init);
614
615bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
616{
617 struct trace_array *tr = trace_file->tr;
618 struct trace_array_cpu *data;
619 struct trace_pid_list *no_pid_list;
620 struct trace_pid_list *pid_list;
621
622 pid_list = rcu_dereference_raw(tr->filtered_pids);
623 no_pid_list = rcu_dereference_raw(tr->filtered_no_pids);
624
625 if (!pid_list && !no_pid_list)
626 return false;
627
628 data = this_cpu_ptr(tr->array_buffer.data);
629
630 return data->ignore_pid;
631}
632EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
633
634void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
635 struct trace_event_file *trace_file,
636 unsigned long len)
637{
638 struct trace_event_call *event_call = trace_file->event_call;
639
640 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
641 trace_event_ignore_this_pid(trace_file))
642 return NULL;
643
644 /*
645 * If CONFIG_PREEMPTION is enabled, then the tracepoint itself disables
646 * preemption (adding one to the preempt_count). Since we are
647 * interested in the preempt_count at the time the tracepoint was
648 * hit, we need to subtract one to offset the increment.
649 */
650 fbuffer->trace_ctx = tracing_gen_ctx_dec();
651 fbuffer->trace_file = trace_file;
652
653 fbuffer->event =
654 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
655 event_call->event.type, len,
656 fbuffer->trace_ctx);
657 if (!fbuffer->event)
658 return NULL;
659
660 fbuffer->regs = NULL;
661 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
662 return fbuffer->entry;
663}
664EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
665
666int trace_event_reg(struct trace_event_call *call,
667 enum trace_reg type, void *data)
668{
669 struct trace_event_file *file = data;
670
671 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
672 switch (type) {
673 case TRACE_REG_REGISTER:
674 return tracepoint_probe_register(call->tp,
675 call->class->probe,
676 file);
677 case TRACE_REG_UNREGISTER:
678 tracepoint_probe_unregister(call->tp,
679 call->class->probe,
680 file);
681 return 0;
682
683#ifdef CONFIG_PERF_EVENTS
684 case TRACE_REG_PERF_REGISTER:
685 return tracepoint_probe_register(call->tp,
686 call->class->perf_probe,
687 call);
688 case TRACE_REG_PERF_UNREGISTER:
689 tracepoint_probe_unregister(call->tp,
690 call->class->perf_probe,
691 call);
692 return 0;
693 case TRACE_REG_PERF_OPEN:
694 case TRACE_REG_PERF_CLOSE:
695 case TRACE_REG_PERF_ADD:
696 case TRACE_REG_PERF_DEL:
697 return 0;
698#endif
699 }
700 return 0;
701}
702EXPORT_SYMBOL_GPL(trace_event_reg);
703
704void trace_event_enable_cmd_record(bool enable)
705{
706 struct trace_event_file *file;
707 struct trace_array *tr;
708
709 lockdep_assert_held(&event_mutex);
710
711 do_for_each_event_file(tr, file) {
712
713 if (!(file->flags & EVENT_FILE_FL_ENABLED))
714 continue;
715
716 if (enable) {
717 tracing_start_cmdline_record();
718 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
719 } else {
720 tracing_stop_cmdline_record();
721 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
722 }
723 } while_for_each_event_file();
724}
725
726void trace_event_enable_tgid_record(bool enable)
727{
728 struct trace_event_file *file;
729 struct trace_array *tr;
730
731 lockdep_assert_held(&event_mutex);
732
733 do_for_each_event_file(tr, file) {
734 if (!(file->flags & EVENT_FILE_FL_ENABLED))
735 continue;
736
737 if (enable) {
738 tracing_start_tgid_record();
739 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
740 } else {
741 tracing_stop_tgid_record();
742 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
743 &file->flags);
744 }
745 } while_for_each_event_file();
746}
747
748static int __ftrace_event_enable_disable(struct trace_event_file *file,
749 int enable, int soft_disable)
750{
751 struct trace_event_call *call = file->event_call;
752 struct trace_array *tr = file->tr;
753 int ret = 0;
754 int disable;
755
756 switch (enable) {
757 case 0:
758 /*
759 * When soft_disable is set and enable is cleared, the sm_ref
760 * reference counter is decremented. If it reaches 0, we want
761 * to clear the SOFT_DISABLED flag but leave the event in the
762 * state that it was. That is, if the event was enabled and
763 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
764 * is set we do not want the event to be enabled before we
765 * clear the bit.
766 *
767 * When soft_disable is not set but the SOFT_MODE flag is,
768 * we do nothing. Do not disable the tracepoint, otherwise
769 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
770 */
771 if (soft_disable) {
772 if (atomic_dec_return(&file->sm_ref) > 0)
773 break;
774 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
775 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
776 /* Disable use of trace_buffered_event */
777 trace_buffered_event_disable();
778 } else
779 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
780
781 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
782 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
783 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
784 tracing_stop_cmdline_record();
785 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
786 }
787
788 if (file->flags & EVENT_FILE_FL_RECORDED_TGID) {
789 tracing_stop_tgid_record();
790 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
791 }
792
793 call->class->reg(call, TRACE_REG_UNREGISTER, file);
794 }
795 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
796 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
797 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
798 else
799 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
800 break;
801 case 1:
802 /*
803 * When soft_disable is set and enable is set, we want to
804 * register the tracepoint for the event, but leave the event
805 * as is. That means, if the event was already enabled, we do
806 * nothing (but set SOFT_MODE). If the event is disabled, we
807 * set SOFT_DISABLED before enabling the event tracepoint, so
808 * it still seems to be disabled.
809 */
810 if (!soft_disable)
811 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
812 else {
813 if (atomic_inc_return(&file->sm_ref) > 1)
814 break;
815 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
816 /* Enable use of trace_buffered_event */
817 trace_buffered_event_enable();
818 }
819
820 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
821 bool cmd = false, tgid = false;
822
823 /* Keep the event disabled, when going to SOFT_MODE. */
824 if (soft_disable)
825 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
826
827 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
828 cmd = true;
829 tracing_start_cmdline_record();
830 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
831 }
832
833 if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
834 tgid = true;
835 tracing_start_tgid_record();
836 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
837 }
838
839 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
840 if (ret) {
841 if (cmd)
842 tracing_stop_cmdline_record();
843 if (tgid)
844 tracing_stop_tgid_record();
845 pr_info("event trace: Could not enable event "
846 "%s\n", trace_event_name(call));
847 break;
848 }
849 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
850
851 /* WAS_ENABLED gets set but never cleared. */
852 set_bit(EVENT_FILE_FL_WAS_ENABLED_BIT, &file->flags);
853 }
854 break;
855 }
856
857 return ret;
858}
859
860int trace_event_enable_disable(struct trace_event_file *file,
861 int enable, int soft_disable)
862{
863 return __ftrace_event_enable_disable(file, enable, soft_disable);
864}
865
866static int ftrace_event_enable_disable(struct trace_event_file *file,
867 int enable)
868{
869 return __ftrace_event_enable_disable(file, enable, 0);
870}
871
872static void ftrace_clear_events(struct trace_array *tr)
873{
874 struct trace_event_file *file;
875
876 mutex_lock(&event_mutex);
877 list_for_each_entry(file, &tr->events, list) {
878 ftrace_event_enable_disable(file, 0);
879 }
880 mutex_unlock(&event_mutex);
881}
882
883static void
884event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
885{
886 struct trace_pid_list *pid_list;
887 struct trace_array *tr = data;
888
889 pid_list = rcu_dereference_raw(tr->filtered_pids);
890 trace_filter_add_remove_task(pid_list, NULL, task);
891
892 pid_list = rcu_dereference_raw(tr->filtered_no_pids);
893 trace_filter_add_remove_task(pid_list, NULL, task);
894}
895
896static void
897event_filter_pid_sched_process_fork(void *data,
898 struct task_struct *self,
899 struct task_struct *task)
900{
901 struct trace_pid_list *pid_list;
902 struct trace_array *tr = data;
903
904 pid_list = rcu_dereference_sched(tr->filtered_pids);
905 trace_filter_add_remove_task(pid_list, self, task);
906
907 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
908 trace_filter_add_remove_task(pid_list, self, task);
909}
910
911void trace_event_follow_fork(struct trace_array *tr, bool enable)
912{
913 if (enable) {
914 register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
915 tr, INT_MIN);
916 register_trace_prio_sched_process_free(event_filter_pid_sched_process_exit,
917 tr, INT_MAX);
918 } else {
919 unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
920 tr);
921 unregister_trace_sched_process_free(event_filter_pid_sched_process_exit,
922 tr);
923 }
924}
925
926static void
927event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
928 struct task_struct *prev,
929 struct task_struct *next,
930 unsigned int prev_state)
931{
932 struct trace_array *tr = data;
933 struct trace_pid_list *no_pid_list;
934 struct trace_pid_list *pid_list;
935 bool ret;
936
937 pid_list = rcu_dereference_sched(tr->filtered_pids);
938 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
939
940 /*
941 * Sched switch is funny, as we only want to ignore it
942 * in the notrace case if both prev and next should be ignored.
943 */
944 ret = trace_ignore_this_task(NULL, no_pid_list, prev) &&
945 trace_ignore_this_task(NULL, no_pid_list, next);
946
947 this_cpu_write(tr->array_buffer.data->ignore_pid, ret ||
948 (trace_ignore_this_task(pid_list, NULL, prev) &&
949 trace_ignore_this_task(pid_list, NULL, next)));
950}
951
952static void
953event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
954 struct task_struct *prev,
955 struct task_struct *next,
956 unsigned int prev_state)
957{
958 struct trace_array *tr = data;
959 struct trace_pid_list *no_pid_list;
960 struct trace_pid_list *pid_list;
961
962 pid_list = rcu_dereference_sched(tr->filtered_pids);
963 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
964
965 this_cpu_write(tr->array_buffer.data->ignore_pid,
966 trace_ignore_this_task(pid_list, no_pid_list, next));
967}
968
969static void
970event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
971{
972 struct trace_array *tr = data;
973 struct trace_pid_list *no_pid_list;
974 struct trace_pid_list *pid_list;
975
976 /* Nothing to do if we are already tracing */
977 if (!this_cpu_read(tr->array_buffer.data->ignore_pid))
978 return;
979
980 pid_list = rcu_dereference_sched(tr->filtered_pids);
981 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
982
983 this_cpu_write(tr->array_buffer.data->ignore_pid,
984 trace_ignore_this_task(pid_list, no_pid_list, task));
985}
986
987static void
988event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
989{
990 struct trace_array *tr = data;
991 struct trace_pid_list *no_pid_list;
992 struct trace_pid_list *pid_list;
993
994 /* Nothing to do if we are not tracing */
995 if (this_cpu_read(tr->array_buffer.data->ignore_pid))
996 return;
997
998 pid_list = rcu_dereference_sched(tr->filtered_pids);
999 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1000
1001 /* Set tracing if current is enabled */
1002 this_cpu_write(tr->array_buffer.data->ignore_pid,
1003 trace_ignore_this_task(pid_list, no_pid_list, current));
1004}
1005
1006static void unregister_pid_events(struct trace_array *tr)
1007{
1008 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
1009 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
1010
1011 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
1012 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
1013
1014 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
1015 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
1016
1017 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
1018 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
1019}
1020
1021static void __ftrace_clear_event_pids(struct trace_array *tr, int type)
1022{
1023 struct trace_pid_list *pid_list;
1024 struct trace_pid_list *no_pid_list;
1025 struct trace_event_file *file;
1026 int cpu;
1027
1028 pid_list = rcu_dereference_protected(tr->filtered_pids,
1029 lockdep_is_held(&event_mutex));
1030 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
1031 lockdep_is_held(&event_mutex));
1032
1033 /* Make sure there's something to do */
1034 if (!pid_type_enabled(type, pid_list, no_pid_list))
1035 return;
1036
1037 if (!still_need_pid_events(type, pid_list, no_pid_list)) {
1038 unregister_pid_events(tr);
1039
1040 list_for_each_entry(file, &tr->events, list) {
1041 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1042 }
1043
1044 for_each_possible_cpu(cpu)
1045 per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false;
1046 }
1047
1048 if (type & TRACE_PIDS)
1049 rcu_assign_pointer(tr->filtered_pids, NULL);
1050
1051 if (type & TRACE_NO_PIDS)
1052 rcu_assign_pointer(tr->filtered_no_pids, NULL);
1053
1054 /* Wait till all users are no longer using pid filtering */
1055 tracepoint_synchronize_unregister();
1056
1057 if ((type & TRACE_PIDS) && pid_list)
1058 trace_pid_list_free(pid_list);
1059
1060 if ((type & TRACE_NO_PIDS) && no_pid_list)
1061 trace_pid_list_free(no_pid_list);
1062}
1063
1064static void ftrace_clear_event_pids(struct trace_array *tr, int type)
1065{
1066 mutex_lock(&event_mutex);
1067 __ftrace_clear_event_pids(tr, type);
1068 mutex_unlock(&event_mutex);
1069}
1070
1071static void __put_system(struct event_subsystem *system)
1072{
1073 struct event_filter *filter = system->filter;
1074
1075 WARN_ON_ONCE(system_refcount(system) == 0);
1076 if (system_refcount_dec(system))
1077 return;
1078
1079 list_del(&system->list);
1080
1081 if (filter) {
1082 kfree(filter->filter_string);
1083 kfree(filter);
1084 }
1085 kfree_const(system->name);
1086 kfree(system);
1087}
1088
1089static void __get_system(struct event_subsystem *system)
1090{
1091 WARN_ON_ONCE(system_refcount(system) == 0);
1092 system_refcount_inc(system);
1093}
1094
1095static void __get_system_dir(struct trace_subsystem_dir *dir)
1096{
1097 WARN_ON_ONCE(dir->ref_count == 0);
1098 dir->ref_count++;
1099 __get_system(dir->subsystem);
1100}
1101
1102static void __put_system_dir(struct trace_subsystem_dir *dir)
1103{
1104 WARN_ON_ONCE(dir->ref_count == 0);
1105 /* If the subsystem is about to be freed, the dir must be too */
1106 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
1107
1108 __put_system(dir->subsystem);
1109 if (!--dir->ref_count)
1110 kfree(dir);
1111}
1112
1113static void put_system(struct trace_subsystem_dir *dir)
1114{
1115 mutex_lock(&event_mutex);
1116 __put_system_dir(dir);
1117 mutex_unlock(&event_mutex);
1118}
1119
1120static void remove_subsystem(struct trace_subsystem_dir *dir)
1121{
1122 if (!dir)
1123 return;
1124
1125 if (!--dir->nr_events) {
1126 eventfs_remove_dir(dir->ei);
1127 list_del(&dir->list);
1128 __put_system_dir(dir);
1129 }
1130}
1131
1132void event_file_get(struct trace_event_file *file)
1133{
1134 refcount_inc(&file->ref);
1135}
1136
1137void event_file_put(struct trace_event_file *file)
1138{
1139 if (WARN_ON_ONCE(!refcount_read(&file->ref))) {
1140 if (file->flags & EVENT_FILE_FL_FREED)
1141 kmem_cache_free(file_cachep, file);
1142 return;
1143 }
1144
1145 if (refcount_dec_and_test(&file->ref)) {
1146 /* Count should only go to zero when it is freed */
1147 if (WARN_ON_ONCE(!(file->flags & EVENT_FILE_FL_FREED)))
1148 return;
1149 kmem_cache_free(file_cachep, file);
1150 }
1151}
1152
1153static void remove_event_file_dir(struct trace_event_file *file)
1154{
1155 eventfs_remove_dir(file->ei);
1156 list_del(&file->list);
1157 remove_subsystem(file->system);
1158 free_event_filter(file->filter);
1159 file->flags |= EVENT_FILE_FL_FREED;
1160 event_file_put(file);
1161}
1162
1163/*
1164 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
1165 */
1166static int
1167__ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
1168 const char *sub, const char *event, int set)
1169{
1170 struct trace_event_file *file;
1171 struct trace_event_call *call;
1172 const char *name;
1173 int ret = -EINVAL;
1174 int eret = 0;
1175
1176 list_for_each_entry(file, &tr->events, list) {
1177
1178 call = file->event_call;
1179 name = trace_event_name(call);
1180
1181 if (!name || !call->class || !call->class->reg)
1182 continue;
1183
1184 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1185 continue;
1186
1187 if (match &&
1188 strcmp(match, name) != 0 &&
1189 strcmp(match, call->class->system) != 0)
1190 continue;
1191
1192 if (sub && strcmp(sub, call->class->system) != 0)
1193 continue;
1194
1195 if (event && strcmp(event, name) != 0)
1196 continue;
1197
1198 ret = ftrace_event_enable_disable(file, set);
1199
1200 /*
1201 * Save the first error and return that. Some events
1202 * may still have been enabled, but let the user
1203 * know that something went wrong.
1204 */
1205 if (ret && !eret)
1206 eret = ret;
1207
1208 ret = eret;
1209 }
1210
1211 return ret;
1212}
1213
1214static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
1215 const char *sub, const char *event, int set)
1216{
1217 int ret;
1218
1219 mutex_lock(&event_mutex);
1220 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
1221 mutex_unlock(&event_mutex);
1222
1223 return ret;
1224}
1225
1226int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
1227{
1228 char *event = NULL, *sub = NULL, *match;
1229 int ret;
1230
1231 if (!tr)
1232 return -ENOENT;
1233 /*
1234 * The buf format can be <subsystem>:<event-name>
1235 * *:<event-name> means any event by that name.
1236 * :<event-name> is the same.
1237 *
1238 * <subsystem>:* means all events in that subsystem
1239 * <subsystem>: means the same.
1240 *
1241 * <name> (no ':') means all events in a subsystem with
1242 * the name <name> or any event that matches <name>
1243 */
1244
1245 match = strsep(&buf, ":");
1246 if (buf) {
1247 sub = match;
1248 event = buf;
1249 match = NULL;
1250
1251 if (!strlen(sub) || strcmp(sub, "*") == 0)
1252 sub = NULL;
1253 if (!strlen(event) || strcmp(event, "*") == 0)
1254 event = NULL;
1255 }
1256
1257 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
1258
1259 /* Put back the colon to allow this to be called again */
1260 if (buf)
1261 *(buf - 1) = ':';
1262
1263 return ret;
1264}
1265
1266/**
1267 * trace_set_clr_event - enable or disable an event
1268 * @system: system name to match (NULL for any system)
1269 * @event: event name to match (NULL for all events, within system)
1270 * @set: 1 to enable, 0 to disable
1271 *
1272 * This is a way for other parts of the kernel to enable or disable
1273 * event recording.
1274 *
1275 * Returns 0 on success, -EINVAL if the parameters do not match any
1276 * registered events.
1277 */
1278int trace_set_clr_event(const char *system, const char *event, int set)
1279{
1280 struct trace_array *tr = top_trace_array();
1281
1282 if (!tr)
1283 return -ENODEV;
1284
1285 return __ftrace_set_clr_event(tr, NULL, system, event, set);
1286}
1287EXPORT_SYMBOL_GPL(trace_set_clr_event);
1288
1289/**
1290 * trace_array_set_clr_event - enable or disable an event for a trace array.
1291 * @tr: concerned trace array.
1292 * @system: system name to match (NULL for any system)
1293 * @event: event name to match (NULL for all events, within system)
1294 * @enable: true to enable, false to disable
1295 *
1296 * This is a way for other parts of the kernel to enable or disable
1297 * event recording.
1298 *
1299 * Returns 0 on success, -EINVAL if the parameters do not match any
1300 * registered events.
1301 */
1302int trace_array_set_clr_event(struct trace_array *tr, const char *system,
1303 const char *event, bool enable)
1304{
1305 int set;
1306
1307 if (!tr)
1308 return -ENOENT;
1309
1310 set = (enable == true) ? 1 : 0;
1311 return __ftrace_set_clr_event(tr, NULL, system, event, set);
1312}
1313EXPORT_SYMBOL_GPL(trace_array_set_clr_event);
1314
1315/* 128 should be much more than enough */
1316#define EVENT_BUF_SIZE 127
1317
1318static ssize_t
1319ftrace_event_write(struct file *file, const char __user *ubuf,
1320 size_t cnt, loff_t *ppos)
1321{
1322 struct trace_parser parser;
1323 struct seq_file *m = file->private_data;
1324 struct trace_array *tr = m->private;
1325 ssize_t read, ret;
1326
1327 if (!cnt)
1328 return 0;
1329
1330 ret = tracing_update_buffers(tr);
1331 if (ret < 0)
1332 return ret;
1333
1334 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
1335 return -ENOMEM;
1336
1337 read = trace_get_user(&parser, ubuf, cnt, ppos);
1338
1339 if (read >= 0 && trace_parser_loaded((&parser))) {
1340 int set = 1;
1341
1342 if (*parser.buffer == '!')
1343 set = 0;
1344
1345 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
1346 if (ret)
1347 goto out_put;
1348 }
1349
1350 ret = read;
1351
1352 out_put:
1353 trace_parser_put(&parser);
1354
1355 return ret;
1356}
1357
1358static void *
1359t_next(struct seq_file *m, void *v, loff_t *pos)
1360{
1361 struct trace_event_file *file = v;
1362 struct trace_event_call *call;
1363 struct trace_array *tr = m->private;
1364
1365 (*pos)++;
1366
1367 list_for_each_entry_continue(file, &tr->events, list) {
1368 call = file->event_call;
1369 /*
1370 * The ftrace subsystem is for showing formats only.
1371 * They can not be enabled or disabled via the event files.
1372 */
1373 if (call->class && call->class->reg &&
1374 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1375 return file;
1376 }
1377
1378 return NULL;
1379}
1380
1381static void *t_start(struct seq_file *m, loff_t *pos)
1382{
1383 struct trace_event_file *file;
1384 struct trace_array *tr = m->private;
1385 loff_t l;
1386
1387 mutex_lock(&event_mutex);
1388
1389 file = list_entry(&tr->events, struct trace_event_file, list);
1390 for (l = 0; l <= *pos; ) {
1391 file = t_next(m, file, &l);
1392 if (!file)
1393 break;
1394 }
1395 return file;
1396}
1397
1398static void *
1399s_next(struct seq_file *m, void *v, loff_t *pos)
1400{
1401 struct trace_event_file *file = v;
1402 struct trace_array *tr = m->private;
1403
1404 (*pos)++;
1405
1406 list_for_each_entry_continue(file, &tr->events, list) {
1407 if (file->flags & EVENT_FILE_FL_ENABLED)
1408 return file;
1409 }
1410
1411 return NULL;
1412}
1413
1414static void *s_start(struct seq_file *m, loff_t *pos)
1415{
1416 struct trace_event_file *file;
1417 struct trace_array *tr = m->private;
1418 loff_t l;
1419
1420 mutex_lock(&event_mutex);
1421
1422 file = list_entry(&tr->events, struct trace_event_file, list);
1423 for (l = 0; l <= *pos; ) {
1424 file = s_next(m, file, &l);
1425 if (!file)
1426 break;
1427 }
1428 return file;
1429}
1430
1431static int t_show(struct seq_file *m, void *v)
1432{
1433 struct trace_event_file *file = v;
1434 struct trace_event_call *call = file->event_call;
1435
1436 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1437 seq_printf(m, "%s:", call->class->system);
1438 seq_printf(m, "%s\n", trace_event_name(call));
1439
1440 return 0;
1441}
1442
1443static void t_stop(struct seq_file *m, void *p)
1444{
1445 mutex_unlock(&event_mutex);
1446}
1447
1448static void *
1449__next(struct seq_file *m, void *v, loff_t *pos, int type)
1450{
1451 struct trace_array *tr = m->private;
1452 struct trace_pid_list *pid_list;
1453
1454 if (type == TRACE_PIDS)
1455 pid_list = rcu_dereference_sched(tr->filtered_pids);
1456 else
1457 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1458
1459 return trace_pid_next(pid_list, v, pos);
1460}
1461
1462static void *
1463p_next(struct seq_file *m, void *v, loff_t *pos)
1464{
1465 return __next(m, v, pos, TRACE_PIDS);
1466}
1467
1468static void *
1469np_next(struct seq_file *m, void *v, loff_t *pos)
1470{
1471 return __next(m, v, pos, TRACE_NO_PIDS);
1472}
1473
1474static void *__start(struct seq_file *m, loff_t *pos, int type)
1475 __acquires(RCU)
1476{
1477 struct trace_pid_list *pid_list;
1478 struct trace_array *tr = m->private;
1479
1480 /*
1481 * Grab the mutex, to keep calls to p_next() having the same
1482 * tr->filtered_pids as p_start() has.
1483 * If we just passed the tr->filtered_pids around, then RCU would
1484 * have been enough, but doing that makes things more complex.
1485 */
1486 mutex_lock(&event_mutex);
1487 rcu_read_lock_sched();
1488
1489 if (type == TRACE_PIDS)
1490 pid_list = rcu_dereference_sched(tr->filtered_pids);
1491 else
1492 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1493
1494 if (!pid_list)
1495 return NULL;
1496
1497 return trace_pid_start(pid_list, pos);
1498}
1499
1500static void *p_start(struct seq_file *m, loff_t *pos)
1501 __acquires(RCU)
1502{
1503 return __start(m, pos, TRACE_PIDS);
1504}
1505
1506static void *np_start(struct seq_file *m, loff_t *pos)
1507 __acquires(RCU)
1508{
1509 return __start(m, pos, TRACE_NO_PIDS);
1510}
1511
1512static void p_stop(struct seq_file *m, void *p)
1513 __releases(RCU)
1514{
1515 rcu_read_unlock_sched();
1516 mutex_unlock(&event_mutex);
1517}
1518
1519static ssize_t
1520event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1521 loff_t *ppos)
1522{
1523 struct trace_event_file *file;
1524 unsigned long flags;
1525 char buf[4] = "0";
1526
1527 mutex_lock(&event_mutex);
1528 file = event_file_file(filp);
1529 if (likely(file))
1530 flags = file->flags;
1531 mutex_unlock(&event_mutex);
1532
1533 if (!file)
1534 return -ENODEV;
1535
1536 if (flags & EVENT_FILE_FL_ENABLED &&
1537 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1538 strcpy(buf, "1");
1539
1540 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1541 flags & EVENT_FILE_FL_SOFT_MODE)
1542 strcat(buf, "*");
1543
1544 strcat(buf, "\n");
1545
1546 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1547}
1548
1549static ssize_t
1550event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1551 loff_t *ppos)
1552{
1553 struct trace_event_file *file;
1554 unsigned long val;
1555 int ret;
1556
1557 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1558 if (ret)
1559 return ret;
1560
1561 switch (val) {
1562 case 0:
1563 case 1:
1564 ret = -ENODEV;
1565 mutex_lock(&event_mutex);
1566 file = event_file_file(filp);
1567 if (likely(file)) {
1568 ret = tracing_update_buffers(file->tr);
1569 if (ret < 0) {
1570 mutex_unlock(&event_mutex);
1571 return ret;
1572 }
1573 ret = ftrace_event_enable_disable(file, val);
1574 }
1575 mutex_unlock(&event_mutex);
1576 break;
1577
1578 default:
1579 return -EINVAL;
1580 }
1581
1582 *ppos += cnt;
1583
1584 return ret ? ret : cnt;
1585}
1586
1587static ssize_t
1588system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1589 loff_t *ppos)
1590{
1591 const char set_to_char[4] = { '?', '0', '1', 'X' };
1592 struct trace_subsystem_dir *dir = filp->private_data;
1593 struct event_subsystem *system = dir->subsystem;
1594 struct trace_event_call *call;
1595 struct trace_event_file *file;
1596 struct trace_array *tr = dir->tr;
1597 char buf[2];
1598 int set = 0;
1599 int ret;
1600
1601 mutex_lock(&event_mutex);
1602 list_for_each_entry(file, &tr->events, list) {
1603 call = file->event_call;
1604 if ((call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) ||
1605 !trace_event_name(call) || !call->class || !call->class->reg)
1606 continue;
1607
1608 if (system && strcmp(call->class->system, system->name) != 0)
1609 continue;
1610
1611 /*
1612 * We need to find out if all the events are set
1613 * or if all events or cleared, or if we have
1614 * a mixture.
1615 */
1616 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1617
1618 /*
1619 * If we have a mixture, no need to look further.
1620 */
1621 if (set == 3)
1622 break;
1623 }
1624 mutex_unlock(&event_mutex);
1625
1626 buf[0] = set_to_char[set];
1627 buf[1] = '\n';
1628
1629 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1630
1631 return ret;
1632}
1633
1634static ssize_t
1635system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1636 loff_t *ppos)
1637{
1638 struct trace_subsystem_dir *dir = filp->private_data;
1639 struct event_subsystem *system = dir->subsystem;
1640 const char *name = NULL;
1641 unsigned long val;
1642 ssize_t ret;
1643
1644 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1645 if (ret)
1646 return ret;
1647
1648 ret = tracing_update_buffers(dir->tr);
1649 if (ret < 0)
1650 return ret;
1651
1652 if (val != 0 && val != 1)
1653 return -EINVAL;
1654
1655 /*
1656 * Opening of "enable" adds a ref count to system,
1657 * so the name is safe to use.
1658 */
1659 if (system)
1660 name = system->name;
1661
1662 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1663 if (ret)
1664 goto out;
1665
1666 ret = cnt;
1667
1668out:
1669 *ppos += cnt;
1670
1671 return ret;
1672}
1673
1674enum {
1675 FORMAT_HEADER = 1,
1676 FORMAT_FIELD_SEPERATOR = 2,
1677 FORMAT_PRINTFMT = 3,
1678};
1679
1680static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1681{
1682 struct trace_event_file *file = event_file_data(m->private);
1683 struct trace_event_call *call = file->event_call;
1684 struct list_head *common_head = &ftrace_common_fields;
1685 struct list_head *head = trace_get_fields(call);
1686 struct list_head *node = v;
1687
1688 (*pos)++;
1689
1690 switch ((unsigned long)v) {
1691 case FORMAT_HEADER:
1692 node = common_head;
1693 break;
1694
1695 case FORMAT_FIELD_SEPERATOR:
1696 node = head;
1697 break;
1698
1699 case FORMAT_PRINTFMT:
1700 /* all done */
1701 return NULL;
1702 }
1703
1704 node = node->prev;
1705 if (node == common_head)
1706 return (void *)FORMAT_FIELD_SEPERATOR;
1707 else if (node == head)
1708 return (void *)FORMAT_PRINTFMT;
1709 else
1710 return node;
1711}
1712
1713static int f_show(struct seq_file *m, void *v)
1714{
1715 struct trace_event_file *file = event_file_data(m->private);
1716 struct trace_event_call *call = file->event_call;
1717 struct ftrace_event_field *field;
1718 const char *array_descriptor;
1719
1720 switch ((unsigned long)v) {
1721 case FORMAT_HEADER:
1722 seq_printf(m, "name: %s\n", trace_event_name(call));
1723 seq_printf(m, "ID: %d\n", call->event.type);
1724 seq_puts(m, "format:\n");
1725 return 0;
1726
1727 case FORMAT_FIELD_SEPERATOR:
1728 seq_putc(m, '\n');
1729 return 0;
1730
1731 case FORMAT_PRINTFMT:
1732 seq_printf(m, "\nprint fmt: %s\n",
1733 call->print_fmt);
1734 return 0;
1735 }
1736
1737 field = list_entry(v, struct ftrace_event_field, link);
1738 /*
1739 * Smartly shows the array type(except dynamic array).
1740 * Normal:
1741 * field:TYPE VAR
1742 * If TYPE := TYPE[LEN], it is shown:
1743 * field:TYPE VAR[LEN]
1744 */
1745 array_descriptor = strchr(field->type, '[');
1746
1747 if (str_has_prefix(field->type, "__data_loc"))
1748 array_descriptor = NULL;
1749
1750 if (!array_descriptor)
1751 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1752 field->type, field->name, field->offset,
1753 field->size, !!field->is_signed);
1754 else if (field->len)
1755 seq_printf(m, "\tfield:%.*s %s[%d];\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1756 (int)(array_descriptor - field->type),
1757 field->type, field->name,
1758 field->len, field->offset,
1759 field->size, !!field->is_signed);
1760 else
1761 seq_printf(m, "\tfield:%.*s %s[];\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1762 (int)(array_descriptor - field->type),
1763 field->type, field->name,
1764 field->offset, field->size, !!field->is_signed);
1765
1766 return 0;
1767}
1768
1769static void *f_start(struct seq_file *m, loff_t *pos)
1770{
1771 struct trace_event_file *file;
1772 void *p = (void *)FORMAT_HEADER;
1773 loff_t l = 0;
1774
1775 /* ->stop() is called even if ->start() fails */
1776 mutex_lock(&event_mutex);
1777 file = event_file_file(m->private);
1778 if (!file)
1779 return ERR_PTR(-ENODEV);
1780
1781 while (l < *pos && p)
1782 p = f_next(m, p, &l);
1783
1784 return p;
1785}
1786
1787static void f_stop(struct seq_file *m, void *p)
1788{
1789 mutex_unlock(&event_mutex);
1790}
1791
1792static const struct seq_operations trace_format_seq_ops = {
1793 .start = f_start,
1794 .next = f_next,
1795 .stop = f_stop,
1796 .show = f_show,
1797};
1798
1799static int trace_format_open(struct inode *inode, struct file *file)
1800{
1801 struct seq_file *m;
1802 int ret;
1803
1804 /* Do we want to hide event format files on tracefs lockdown? */
1805
1806 ret = seq_open(file, &trace_format_seq_ops);
1807 if (ret < 0)
1808 return ret;
1809
1810 m = file->private_data;
1811 m->private = file;
1812
1813 return 0;
1814}
1815
1816#ifdef CONFIG_PERF_EVENTS
1817static ssize_t
1818event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1819{
1820 int id = (long)event_file_data(filp);
1821 char buf[32];
1822 int len;
1823
1824 if (unlikely(!id))
1825 return -ENODEV;
1826
1827 len = sprintf(buf, "%d\n", id);
1828
1829 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1830}
1831#endif
1832
1833static ssize_t
1834event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1835 loff_t *ppos)
1836{
1837 struct trace_event_file *file;
1838 struct trace_seq *s;
1839 int r = -ENODEV;
1840
1841 if (*ppos)
1842 return 0;
1843
1844 s = kmalloc(sizeof(*s), GFP_KERNEL);
1845
1846 if (!s)
1847 return -ENOMEM;
1848
1849 trace_seq_init(s);
1850
1851 mutex_lock(&event_mutex);
1852 file = event_file_file(filp);
1853 if (file)
1854 print_event_filter(file, s);
1855 mutex_unlock(&event_mutex);
1856
1857 if (file)
1858 r = simple_read_from_buffer(ubuf, cnt, ppos,
1859 s->buffer, trace_seq_used(s));
1860
1861 kfree(s);
1862
1863 return r;
1864}
1865
1866static ssize_t
1867event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1868 loff_t *ppos)
1869{
1870 struct trace_event_file *file;
1871 char *buf;
1872 int err = -ENODEV;
1873
1874 if (cnt >= PAGE_SIZE)
1875 return -EINVAL;
1876
1877 buf = memdup_user_nul(ubuf, cnt);
1878 if (IS_ERR(buf))
1879 return PTR_ERR(buf);
1880
1881 mutex_lock(&event_mutex);
1882 file = event_file_file(filp);
1883 if (file) {
1884 if (file->flags & EVENT_FILE_FL_FREED)
1885 err = -ENODEV;
1886 else
1887 err = apply_event_filter(file, buf);
1888 }
1889 mutex_unlock(&event_mutex);
1890
1891 kfree(buf);
1892 if (err < 0)
1893 return err;
1894
1895 *ppos += cnt;
1896
1897 return cnt;
1898}
1899
1900static LIST_HEAD(event_subsystems);
1901
1902static int subsystem_open(struct inode *inode, struct file *filp)
1903{
1904 struct trace_subsystem_dir *dir = NULL, *iter_dir;
1905 struct trace_array *tr = NULL, *iter_tr;
1906 struct event_subsystem *system = NULL;
1907 int ret;
1908
1909 if (tracing_is_disabled())
1910 return -ENODEV;
1911
1912 /* Make sure the system still exists */
1913 mutex_lock(&event_mutex);
1914 mutex_lock(&trace_types_lock);
1915 list_for_each_entry(iter_tr, &ftrace_trace_arrays, list) {
1916 list_for_each_entry(iter_dir, &iter_tr->systems, list) {
1917 if (iter_dir == inode->i_private) {
1918 /* Don't open systems with no events */
1919 tr = iter_tr;
1920 dir = iter_dir;
1921 if (dir->nr_events) {
1922 __get_system_dir(dir);
1923 system = dir->subsystem;
1924 }
1925 goto exit_loop;
1926 }
1927 }
1928 }
1929 exit_loop:
1930 mutex_unlock(&trace_types_lock);
1931 mutex_unlock(&event_mutex);
1932
1933 if (!system)
1934 return -ENODEV;
1935
1936 /* Still need to increment the ref count of the system */
1937 if (trace_array_get(tr) < 0) {
1938 put_system(dir);
1939 return -ENODEV;
1940 }
1941
1942 ret = tracing_open_generic(inode, filp);
1943 if (ret < 0) {
1944 trace_array_put(tr);
1945 put_system(dir);
1946 }
1947
1948 return ret;
1949}
1950
1951static int system_tr_open(struct inode *inode, struct file *filp)
1952{
1953 struct trace_subsystem_dir *dir;
1954 struct trace_array *tr = inode->i_private;
1955 int ret;
1956
1957 /* Make a temporary dir that has no system but points to tr */
1958 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1959 if (!dir)
1960 return -ENOMEM;
1961
1962 ret = tracing_open_generic_tr(inode, filp);
1963 if (ret < 0) {
1964 kfree(dir);
1965 return ret;
1966 }
1967 dir->tr = tr;
1968 filp->private_data = dir;
1969
1970 return 0;
1971}
1972
1973static int subsystem_release(struct inode *inode, struct file *file)
1974{
1975 struct trace_subsystem_dir *dir = file->private_data;
1976
1977 trace_array_put(dir->tr);
1978
1979 /*
1980 * If dir->subsystem is NULL, then this is a temporary
1981 * descriptor that was made for a trace_array to enable
1982 * all subsystems.
1983 */
1984 if (dir->subsystem)
1985 put_system(dir);
1986 else
1987 kfree(dir);
1988
1989 return 0;
1990}
1991
1992static ssize_t
1993subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1994 loff_t *ppos)
1995{
1996 struct trace_subsystem_dir *dir = filp->private_data;
1997 struct event_subsystem *system = dir->subsystem;
1998 struct trace_seq *s;
1999 int r;
2000
2001 if (*ppos)
2002 return 0;
2003
2004 s = kmalloc(sizeof(*s), GFP_KERNEL);
2005 if (!s)
2006 return -ENOMEM;
2007
2008 trace_seq_init(s);
2009
2010 print_subsystem_event_filter(system, s);
2011 r = simple_read_from_buffer(ubuf, cnt, ppos,
2012 s->buffer, trace_seq_used(s));
2013
2014 kfree(s);
2015
2016 return r;
2017}
2018
2019static ssize_t
2020subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
2021 loff_t *ppos)
2022{
2023 struct trace_subsystem_dir *dir = filp->private_data;
2024 char *buf;
2025 int err;
2026
2027 if (cnt >= PAGE_SIZE)
2028 return -EINVAL;
2029
2030 buf = memdup_user_nul(ubuf, cnt);
2031 if (IS_ERR(buf))
2032 return PTR_ERR(buf);
2033
2034 err = apply_subsystem_event_filter(dir, buf);
2035 kfree(buf);
2036 if (err < 0)
2037 return err;
2038
2039 *ppos += cnt;
2040
2041 return cnt;
2042}
2043
2044static ssize_t
2045show_header_page_file(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
2046{
2047 struct trace_array *tr = filp->private_data;
2048 struct trace_seq *s;
2049 int r;
2050
2051 if (*ppos)
2052 return 0;
2053
2054 s = kmalloc(sizeof(*s), GFP_KERNEL);
2055 if (!s)
2056 return -ENOMEM;
2057
2058 trace_seq_init(s);
2059
2060 ring_buffer_print_page_header(tr->array_buffer.buffer, s);
2061 r = simple_read_from_buffer(ubuf, cnt, ppos,
2062 s->buffer, trace_seq_used(s));
2063
2064 kfree(s);
2065
2066 return r;
2067}
2068
2069static ssize_t
2070show_header_event_file(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
2071{
2072 struct trace_seq *s;
2073 int r;
2074
2075 if (*ppos)
2076 return 0;
2077
2078 s = kmalloc(sizeof(*s), GFP_KERNEL);
2079 if (!s)
2080 return -ENOMEM;
2081
2082 trace_seq_init(s);
2083
2084 ring_buffer_print_entry_header(s);
2085 r = simple_read_from_buffer(ubuf, cnt, ppos,
2086 s->buffer, trace_seq_used(s));
2087
2088 kfree(s);
2089
2090 return r;
2091}
2092
2093static void ignore_task_cpu(void *data)
2094{
2095 struct trace_array *tr = data;
2096 struct trace_pid_list *pid_list;
2097 struct trace_pid_list *no_pid_list;
2098
2099 /*
2100 * This function is called by on_each_cpu() while the
2101 * event_mutex is held.
2102 */
2103 pid_list = rcu_dereference_protected(tr->filtered_pids,
2104 mutex_is_locked(&event_mutex));
2105 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
2106 mutex_is_locked(&event_mutex));
2107
2108 this_cpu_write(tr->array_buffer.data->ignore_pid,
2109 trace_ignore_this_task(pid_list, no_pid_list, current));
2110}
2111
2112static void register_pid_events(struct trace_array *tr)
2113{
2114 /*
2115 * Register a probe that is called before all other probes
2116 * to set ignore_pid if next or prev do not match.
2117 * Register a probe this is called after all other probes
2118 * to only keep ignore_pid set if next pid matches.
2119 */
2120 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
2121 tr, INT_MAX);
2122 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
2123 tr, 0);
2124
2125 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
2126 tr, INT_MAX);
2127 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
2128 tr, 0);
2129
2130 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
2131 tr, INT_MAX);
2132 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
2133 tr, 0);
2134
2135 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
2136 tr, INT_MAX);
2137 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
2138 tr, 0);
2139}
2140
2141static ssize_t
2142event_pid_write(struct file *filp, const char __user *ubuf,
2143 size_t cnt, loff_t *ppos, int type)
2144{
2145 struct seq_file *m = filp->private_data;
2146 struct trace_array *tr = m->private;
2147 struct trace_pid_list *filtered_pids = NULL;
2148 struct trace_pid_list *other_pids = NULL;
2149 struct trace_pid_list *pid_list;
2150 struct trace_event_file *file;
2151 ssize_t ret;
2152
2153 if (!cnt)
2154 return 0;
2155
2156 ret = tracing_update_buffers(tr);
2157 if (ret < 0)
2158 return ret;
2159
2160 mutex_lock(&event_mutex);
2161
2162 if (type == TRACE_PIDS) {
2163 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
2164 lockdep_is_held(&event_mutex));
2165 other_pids = rcu_dereference_protected(tr->filtered_no_pids,
2166 lockdep_is_held(&event_mutex));
2167 } else {
2168 filtered_pids = rcu_dereference_protected(tr->filtered_no_pids,
2169 lockdep_is_held(&event_mutex));
2170 other_pids = rcu_dereference_protected(tr->filtered_pids,
2171 lockdep_is_held(&event_mutex));
2172 }
2173
2174 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
2175 if (ret < 0)
2176 goto out;
2177
2178 if (type == TRACE_PIDS)
2179 rcu_assign_pointer(tr->filtered_pids, pid_list);
2180 else
2181 rcu_assign_pointer(tr->filtered_no_pids, pid_list);
2182
2183 list_for_each_entry(file, &tr->events, list) {
2184 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
2185 }
2186
2187 if (filtered_pids) {
2188 tracepoint_synchronize_unregister();
2189 trace_pid_list_free(filtered_pids);
2190 } else if (pid_list && !other_pids) {
2191 register_pid_events(tr);
2192 }
2193
2194 /*
2195 * Ignoring of pids is done at task switch. But we have to
2196 * check for those tasks that are currently running.
2197 * Always do this in case a pid was appended or removed.
2198 */
2199 on_each_cpu(ignore_task_cpu, tr, 1);
2200
2201 out:
2202 mutex_unlock(&event_mutex);
2203
2204 if (ret > 0)
2205 *ppos += ret;
2206
2207 return ret;
2208}
2209
2210static ssize_t
2211ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
2212 size_t cnt, loff_t *ppos)
2213{
2214 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
2215}
2216
2217static ssize_t
2218ftrace_event_npid_write(struct file *filp, const char __user *ubuf,
2219 size_t cnt, loff_t *ppos)
2220{
2221 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
2222}
2223
2224static int ftrace_event_avail_open(struct inode *inode, struct file *file);
2225static int ftrace_event_set_open(struct inode *inode, struct file *file);
2226static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
2227static int ftrace_event_set_npid_open(struct inode *inode, struct file *file);
2228static int ftrace_event_release(struct inode *inode, struct file *file);
2229
2230static const struct seq_operations show_event_seq_ops = {
2231 .start = t_start,
2232 .next = t_next,
2233 .show = t_show,
2234 .stop = t_stop,
2235};
2236
2237static const struct seq_operations show_set_event_seq_ops = {
2238 .start = s_start,
2239 .next = s_next,
2240 .show = t_show,
2241 .stop = t_stop,
2242};
2243
2244static const struct seq_operations show_set_pid_seq_ops = {
2245 .start = p_start,
2246 .next = p_next,
2247 .show = trace_pid_show,
2248 .stop = p_stop,
2249};
2250
2251static const struct seq_operations show_set_no_pid_seq_ops = {
2252 .start = np_start,
2253 .next = np_next,
2254 .show = trace_pid_show,
2255 .stop = p_stop,
2256};
2257
2258static const struct file_operations ftrace_avail_fops = {
2259 .open = ftrace_event_avail_open,
2260 .read = seq_read,
2261 .llseek = seq_lseek,
2262 .release = seq_release,
2263};
2264
2265static const struct file_operations ftrace_set_event_fops = {
2266 .open = ftrace_event_set_open,
2267 .read = seq_read,
2268 .write = ftrace_event_write,
2269 .llseek = seq_lseek,
2270 .release = ftrace_event_release,
2271};
2272
2273static const struct file_operations ftrace_set_event_pid_fops = {
2274 .open = ftrace_event_set_pid_open,
2275 .read = seq_read,
2276 .write = ftrace_event_pid_write,
2277 .llseek = seq_lseek,
2278 .release = ftrace_event_release,
2279};
2280
2281static const struct file_operations ftrace_set_event_notrace_pid_fops = {
2282 .open = ftrace_event_set_npid_open,
2283 .read = seq_read,
2284 .write = ftrace_event_npid_write,
2285 .llseek = seq_lseek,
2286 .release = ftrace_event_release,
2287};
2288
2289static const struct file_operations ftrace_enable_fops = {
2290 .open = tracing_open_file_tr,
2291 .read = event_enable_read,
2292 .write = event_enable_write,
2293 .release = tracing_release_file_tr,
2294 .llseek = default_llseek,
2295};
2296
2297static const struct file_operations ftrace_event_format_fops = {
2298 .open = trace_format_open,
2299 .read = seq_read,
2300 .llseek = seq_lseek,
2301 .release = seq_release,
2302};
2303
2304#ifdef CONFIG_PERF_EVENTS
2305static const struct file_operations ftrace_event_id_fops = {
2306 .read = event_id_read,
2307 .llseek = default_llseek,
2308};
2309#endif
2310
2311static const struct file_operations ftrace_event_filter_fops = {
2312 .open = tracing_open_file_tr,
2313 .read = event_filter_read,
2314 .write = event_filter_write,
2315 .release = tracing_release_file_tr,
2316 .llseek = default_llseek,
2317};
2318
2319static const struct file_operations ftrace_subsystem_filter_fops = {
2320 .open = subsystem_open,
2321 .read = subsystem_filter_read,
2322 .write = subsystem_filter_write,
2323 .llseek = default_llseek,
2324 .release = subsystem_release,
2325};
2326
2327static const struct file_operations ftrace_system_enable_fops = {
2328 .open = subsystem_open,
2329 .read = system_enable_read,
2330 .write = system_enable_write,
2331 .llseek = default_llseek,
2332 .release = subsystem_release,
2333};
2334
2335static const struct file_operations ftrace_tr_enable_fops = {
2336 .open = system_tr_open,
2337 .read = system_enable_read,
2338 .write = system_enable_write,
2339 .llseek = default_llseek,
2340 .release = subsystem_release,
2341};
2342
2343static const struct file_operations ftrace_show_header_page_fops = {
2344 .open = tracing_open_generic_tr,
2345 .read = show_header_page_file,
2346 .llseek = default_llseek,
2347 .release = tracing_release_generic_tr,
2348};
2349
2350static const struct file_operations ftrace_show_header_event_fops = {
2351 .open = tracing_open_generic_tr,
2352 .read = show_header_event_file,
2353 .llseek = default_llseek,
2354 .release = tracing_release_generic_tr,
2355};
2356
2357static int
2358ftrace_event_open(struct inode *inode, struct file *file,
2359 const struct seq_operations *seq_ops)
2360{
2361 struct seq_file *m;
2362 int ret;
2363
2364 ret = security_locked_down(LOCKDOWN_TRACEFS);
2365 if (ret)
2366 return ret;
2367
2368 ret = seq_open(file, seq_ops);
2369 if (ret < 0)
2370 return ret;
2371 m = file->private_data;
2372 /* copy tr over to seq ops */
2373 m->private = inode->i_private;
2374
2375 return ret;
2376}
2377
2378static int ftrace_event_release(struct inode *inode, struct file *file)
2379{
2380 struct trace_array *tr = inode->i_private;
2381
2382 trace_array_put(tr);
2383
2384 return seq_release(inode, file);
2385}
2386
2387static int
2388ftrace_event_avail_open(struct inode *inode, struct file *file)
2389{
2390 const struct seq_operations *seq_ops = &show_event_seq_ops;
2391
2392 /* Checks for tracefs lockdown */
2393 return ftrace_event_open(inode, file, seq_ops);
2394}
2395
2396static int
2397ftrace_event_set_open(struct inode *inode, struct file *file)
2398{
2399 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
2400 struct trace_array *tr = inode->i_private;
2401 int ret;
2402
2403 ret = tracing_check_open_get_tr(tr);
2404 if (ret)
2405 return ret;
2406
2407 if ((file->f_mode & FMODE_WRITE) &&
2408 (file->f_flags & O_TRUNC))
2409 ftrace_clear_events(tr);
2410
2411 ret = ftrace_event_open(inode, file, seq_ops);
2412 if (ret < 0)
2413 trace_array_put(tr);
2414 return ret;
2415}
2416
2417static int
2418ftrace_event_set_pid_open(struct inode *inode, struct file *file)
2419{
2420 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
2421 struct trace_array *tr = inode->i_private;
2422 int ret;
2423
2424 ret = tracing_check_open_get_tr(tr);
2425 if (ret)
2426 return ret;
2427
2428 if ((file->f_mode & FMODE_WRITE) &&
2429 (file->f_flags & O_TRUNC))
2430 ftrace_clear_event_pids(tr, TRACE_PIDS);
2431
2432 ret = ftrace_event_open(inode, file, seq_ops);
2433 if (ret < 0)
2434 trace_array_put(tr);
2435 return ret;
2436}
2437
2438static int
2439ftrace_event_set_npid_open(struct inode *inode, struct file *file)
2440{
2441 const struct seq_operations *seq_ops = &show_set_no_pid_seq_ops;
2442 struct trace_array *tr = inode->i_private;
2443 int ret;
2444
2445 ret = tracing_check_open_get_tr(tr);
2446 if (ret)
2447 return ret;
2448
2449 if ((file->f_mode & FMODE_WRITE) &&
2450 (file->f_flags & O_TRUNC))
2451 ftrace_clear_event_pids(tr, TRACE_NO_PIDS);
2452
2453 ret = ftrace_event_open(inode, file, seq_ops);
2454 if (ret < 0)
2455 trace_array_put(tr);
2456 return ret;
2457}
2458
2459static struct event_subsystem *
2460create_new_subsystem(const char *name)
2461{
2462 struct event_subsystem *system;
2463
2464 /* need to create new entry */
2465 system = kmalloc(sizeof(*system), GFP_KERNEL);
2466 if (!system)
2467 return NULL;
2468
2469 system->ref_count = 1;
2470
2471 /* Only allocate if dynamic (kprobes and modules) */
2472 system->name = kstrdup_const(name, GFP_KERNEL);
2473 if (!system->name)
2474 goto out_free;
2475
2476 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
2477 if (!system->filter)
2478 goto out_free;
2479
2480 list_add(&system->list, &event_subsystems);
2481
2482 return system;
2483
2484 out_free:
2485 kfree_const(system->name);
2486 kfree(system);
2487 return NULL;
2488}
2489
2490static int system_callback(const char *name, umode_t *mode, void **data,
2491 const struct file_operations **fops)
2492{
2493 if (strcmp(name, "filter") == 0)
2494 *fops = &ftrace_subsystem_filter_fops;
2495
2496 else if (strcmp(name, "enable") == 0)
2497 *fops = &ftrace_system_enable_fops;
2498
2499 else
2500 return 0;
2501
2502 *mode = TRACE_MODE_WRITE;
2503 return 1;
2504}
2505
2506static struct eventfs_inode *
2507event_subsystem_dir(struct trace_array *tr, const char *name,
2508 struct trace_event_file *file, struct eventfs_inode *parent)
2509{
2510 struct event_subsystem *system, *iter;
2511 struct trace_subsystem_dir *dir;
2512 struct eventfs_inode *ei;
2513 int nr_entries;
2514 static struct eventfs_entry system_entries[] = {
2515 {
2516 .name = "filter",
2517 .callback = system_callback,
2518 },
2519 {
2520 .name = "enable",
2521 .callback = system_callback,
2522 }
2523 };
2524
2525 /* First see if we did not already create this dir */
2526 list_for_each_entry(dir, &tr->systems, list) {
2527 system = dir->subsystem;
2528 if (strcmp(system->name, name) == 0) {
2529 dir->nr_events++;
2530 file->system = dir;
2531 return dir->ei;
2532 }
2533 }
2534
2535 /* Now see if the system itself exists. */
2536 system = NULL;
2537 list_for_each_entry(iter, &event_subsystems, list) {
2538 if (strcmp(iter->name, name) == 0) {
2539 system = iter;
2540 break;
2541 }
2542 }
2543
2544 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
2545 if (!dir)
2546 goto out_fail;
2547
2548 if (!system) {
2549 system = create_new_subsystem(name);
2550 if (!system)
2551 goto out_free;
2552 } else
2553 __get_system(system);
2554
2555 /* ftrace only has directories no files */
2556 if (strcmp(name, "ftrace") == 0)
2557 nr_entries = 0;
2558 else
2559 nr_entries = ARRAY_SIZE(system_entries);
2560
2561 ei = eventfs_create_dir(name, parent, system_entries, nr_entries, dir);
2562 if (IS_ERR(ei)) {
2563 pr_warn("Failed to create system directory %s\n", name);
2564 __put_system(system);
2565 goto out_free;
2566 }
2567
2568 dir->ei = ei;
2569 dir->tr = tr;
2570 dir->ref_count = 1;
2571 dir->nr_events = 1;
2572 dir->subsystem = system;
2573 file->system = dir;
2574
2575 list_add(&dir->list, &tr->systems);
2576
2577 return dir->ei;
2578
2579 out_free:
2580 kfree(dir);
2581 out_fail:
2582 /* Only print this message if failed on memory allocation */
2583 if (!dir || !system)
2584 pr_warn("No memory to create event subsystem %s\n", name);
2585 return NULL;
2586}
2587
2588static int
2589event_define_fields(struct trace_event_call *call)
2590{
2591 struct list_head *head;
2592 int ret = 0;
2593
2594 /*
2595 * Other events may have the same class. Only update
2596 * the fields if they are not already defined.
2597 */
2598 head = trace_get_fields(call);
2599 if (list_empty(head)) {
2600 struct trace_event_fields *field = call->class->fields_array;
2601 unsigned int offset = sizeof(struct trace_entry);
2602
2603 for (; field->type; field++) {
2604 if (field->type == TRACE_FUNCTION_TYPE) {
2605 field->define_fields(call);
2606 break;
2607 }
2608
2609 offset = ALIGN(offset, field->align);
2610 ret = trace_define_field_ext(call, field->type, field->name,
2611 offset, field->size,
2612 field->is_signed, field->filter_type,
2613 field->len, field->needs_test);
2614 if (WARN_ON_ONCE(ret)) {
2615 pr_err("error code is %d\n", ret);
2616 break;
2617 }
2618
2619 offset += field->size;
2620 }
2621 }
2622
2623 return ret;
2624}
2625
2626static int event_callback(const char *name, umode_t *mode, void **data,
2627 const struct file_operations **fops)
2628{
2629 struct trace_event_file *file = *data;
2630 struct trace_event_call *call = file->event_call;
2631
2632 if (strcmp(name, "format") == 0) {
2633 *mode = TRACE_MODE_READ;
2634 *fops = &ftrace_event_format_fops;
2635 return 1;
2636 }
2637
2638 /*
2639 * Only event directories that can be enabled should have
2640 * triggers or filters, with the exception of the "print"
2641 * event that can have a "trigger" file.
2642 */
2643 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
2644 if (call->class->reg && strcmp(name, "enable") == 0) {
2645 *mode = TRACE_MODE_WRITE;
2646 *fops = &ftrace_enable_fops;
2647 return 1;
2648 }
2649
2650 if (strcmp(name, "filter") == 0) {
2651 *mode = TRACE_MODE_WRITE;
2652 *fops = &ftrace_event_filter_fops;
2653 return 1;
2654 }
2655 }
2656
2657 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) ||
2658 strcmp(trace_event_name(call), "print") == 0) {
2659 if (strcmp(name, "trigger") == 0) {
2660 *mode = TRACE_MODE_WRITE;
2661 *fops = &event_trigger_fops;
2662 return 1;
2663 }
2664 }
2665
2666#ifdef CONFIG_PERF_EVENTS
2667 if (call->event.type && call->class->reg &&
2668 strcmp(name, "id") == 0) {
2669 *mode = TRACE_MODE_READ;
2670 *data = (void *)(long)call->event.type;
2671 *fops = &ftrace_event_id_fops;
2672 return 1;
2673 }
2674#endif
2675
2676#ifdef CONFIG_HIST_TRIGGERS
2677 if (strcmp(name, "hist") == 0) {
2678 *mode = TRACE_MODE_READ;
2679 *fops = &event_hist_fops;
2680 return 1;
2681 }
2682#endif
2683#ifdef CONFIG_HIST_TRIGGERS_DEBUG
2684 if (strcmp(name, "hist_debug") == 0) {
2685 *mode = TRACE_MODE_READ;
2686 *fops = &event_hist_debug_fops;
2687 return 1;
2688 }
2689#endif
2690#ifdef CONFIG_TRACE_EVENT_INJECT
2691 if (call->event.type && call->class->reg &&
2692 strcmp(name, "inject") == 0) {
2693 *mode = 0200;
2694 *fops = &event_inject_fops;
2695 return 1;
2696 }
2697#endif
2698 return 0;
2699}
2700
2701/* The file is incremented on creation and freeing the enable file decrements it */
2702static void event_release(const char *name, void *data)
2703{
2704 struct trace_event_file *file = data;
2705
2706 event_file_put(file);
2707}
2708
2709static int
2710event_create_dir(struct eventfs_inode *parent, struct trace_event_file *file)
2711{
2712 struct trace_event_call *call = file->event_call;
2713 struct trace_array *tr = file->tr;
2714 struct eventfs_inode *e_events;
2715 struct eventfs_inode *ei;
2716 const char *name;
2717 int nr_entries;
2718 int ret;
2719 static struct eventfs_entry event_entries[] = {
2720 {
2721 .name = "enable",
2722 .callback = event_callback,
2723 .release = event_release,
2724 },
2725 {
2726 .name = "filter",
2727 .callback = event_callback,
2728 },
2729 {
2730 .name = "trigger",
2731 .callback = event_callback,
2732 },
2733 {
2734 .name = "format",
2735 .callback = event_callback,
2736 },
2737#ifdef CONFIG_PERF_EVENTS
2738 {
2739 .name = "id",
2740 .callback = event_callback,
2741 },
2742#endif
2743#ifdef CONFIG_HIST_TRIGGERS
2744 {
2745 .name = "hist",
2746 .callback = event_callback,
2747 },
2748#endif
2749#ifdef CONFIG_HIST_TRIGGERS_DEBUG
2750 {
2751 .name = "hist_debug",
2752 .callback = event_callback,
2753 },
2754#endif
2755#ifdef CONFIG_TRACE_EVENT_INJECT
2756 {
2757 .name = "inject",
2758 .callback = event_callback,
2759 },
2760#endif
2761 };
2762
2763 /*
2764 * If the trace point header did not define TRACE_SYSTEM
2765 * then the system would be called "TRACE_SYSTEM". This should
2766 * never happen.
2767 */
2768 if (WARN_ON_ONCE(strcmp(call->class->system, TRACE_SYSTEM) == 0))
2769 return -ENODEV;
2770
2771 e_events = event_subsystem_dir(tr, call->class->system, file, parent);
2772 if (!e_events)
2773 return -ENOMEM;
2774
2775 nr_entries = ARRAY_SIZE(event_entries);
2776
2777 name = trace_event_name(call);
2778 ei = eventfs_create_dir(name, e_events, event_entries, nr_entries, file);
2779 if (IS_ERR(ei)) {
2780 pr_warn("Could not create tracefs '%s' directory\n", name);
2781 return -1;
2782 }
2783
2784 file->ei = ei;
2785
2786 ret = event_define_fields(call);
2787 if (ret < 0) {
2788 pr_warn("Could not initialize trace point events/%s\n", name);
2789 return ret;
2790 }
2791
2792 /* Gets decremented on freeing of the "enable" file */
2793 event_file_get(file);
2794
2795 return 0;
2796}
2797
2798static void remove_event_from_tracers(struct trace_event_call *call)
2799{
2800 struct trace_event_file *file;
2801 struct trace_array *tr;
2802
2803 do_for_each_event_file_safe(tr, file) {
2804 if (file->event_call != call)
2805 continue;
2806
2807 remove_event_file_dir(file);
2808 /*
2809 * The do_for_each_event_file_safe() is
2810 * a double loop. After finding the call for this
2811 * trace_array, we use break to jump to the next
2812 * trace_array.
2813 */
2814 break;
2815 } while_for_each_event_file();
2816}
2817
2818static void event_remove(struct trace_event_call *call)
2819{
2820 struct trace_array *tr;
2821 struct trace_event_file *file;
2822
2823 do_for_each_event_file(tr, file) {
2824 if (file->event_call != call)
2825 continue;
2826
2827 if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
2828 tr->clear_trace = true;
2829
2830 ftrace_event_enable_disable(file, 0);
2831 /*
2832 * The do_for_each_event_file() is
2833 * a double loop. After finding the call for this
2834 * trace_array, we use break to jump to the next
2835 * trace_array.
2836 */
2837 break;
2838 } while_for_each_event_file();
2839
2840 if (call->event.funcs)
2841 __unregister_trace_event(&call->event);
2842 remove_event_from_tracers(call);
2843 list_del(&call->list);
2844}
2845
2846static int event_init(struct trace_event_call *call)
2847{
2848 int ret = 0;
2849 const char *name;
2850
2851 name = trace_event_name(call);
2852 if (WARN_ON(!name))
2853 return -EINVAL;
2854
2855 if (call->class->raw_init) {
2856 ret = call->class->raw_init(call);
2857 if (ret < 0 && ret != -ENOSYS)
2858 pr_warn("Could not initialize trace events/%s\n", name);
2859 }
2860
2861 return ret;
2862}
2863
2864static int
2865__register_event(struct trace_event_call *call, struct module *mod)
2866{
2867 int ret;
2868
2869 ret = event_init(call);
2870 if (ret < 0)
2871 return ret;
2872
2873 list_add(&call->list, &ftrace_events);
2874 if (call->flags & TRACE_EVENT_FL_DYNAMIC)
2875 atomic_set(&call->refcnt, 0);
2876 else
2877 call->module = mod;
2878
2879 return 0;
2880}
2881
2882static char *eval_replace(char *ptr, struct trace_eval_map *map, int len)
2883{
2884 int rlen;
2885 int elen;
2886
2887 /* Find the length of the eval value as a string */
2888 elen = snprintf(ptr, 0, "%ld", map->eval_value);
2889 /* Make sure there's enough room to replace the string with the value */
2890 if (len < elen)
2891 return NULL;
2892
2893 snprintf(ptr, elen + 1, "%ld", map->eval_value);
2894
2895 /* Get the rest of the string of ptr */
2896 rlen = strlen(ptr + len);
2897 memmove(ptr + elen, ptr + len, rlen);
2898 /* Make sure we end the new string */
2899 ptr[elen + rlen] = 0;
2900
2901 return ptr + elen;
2902}
2903
2904static void update_event_printk(struct trace_event_call *call,
2905 struct trace_eval_map *map)
2906{
2907 char *ptr;
2908 int quote = 0;
2909 int len = strlen(map->eval_string);
2910
2911 for (ptr = call->print_fmt; *ptr; ptr++) {
2912 if (*ptr == '\\') {
2913 ptr++;
2914 /* paranoid */
2915 if (!*ptr)
2916 break;
2917 continue;
2918 }
2919 if (*ptr == '"') {
2920 quote ^= 1;
2921 continue;
2922 }
2923 if (quote)
2924 continue;
2925 if (isdigit(*ptr)) {
2926 /* skip numbers */
2927 do {
2928 ptr++;
2929 /* Check for alpha chars like ULL */
2930 } while (isalnum(*ptr));
2931 if (!*ptr)
2932 break;
2933 /*
2934 * A number must have some kind of delimiter after
2935 * it, and we can ignore that too.
2936 */
2937 continue;
2938 }
2939 if (isalpha(*ptr) || *ptr == '_') {
2940 if (strncmp(map->eval_string, ptr, len) == 0 &&
2941 !isalnum(ptr[len]) && ptr[len] != '_') {
2942 ptr = eval_replace(ptr, map, len);
2943 /* enum/sizeof string smaller than value */
2944 if (WARN_ON_ONCE(!ptr))
2945 return;
2946 /*
2947 * No need to decrement here, as eval_replace()
2948 * returns the pointer to the character passed
2949 * the eval, and two evals can not be placed
2950 * back to back without something in between.
2951 * We can skip that something in between.
2952 */
2953 continue;
2954 }
2955 skip_more:
2956 do {
2957 ptr++;
2958 } while (isalnum(*ptr) || *ptr == '_');
2959 if (!*ptr)
2960 break;
2961 /*
2962 * If what comes after this variable is a '.' or
2963 * '->' then we can continue to ignore that string.
2964 */
2965 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2966 ptr += *ptr == '.' ? 1 : 2;
2967 if (!*ptr)
2968 break;
2969 goto skip_more;
2970 }
2971 /*
2972 * Once again, we can skip the delimiter that came
2973 * after the string.
2974 */
2975 continue;
2976 }
2977 }
2978}
2979
2980static void add_str_to_module(struct module *module, char *str)
2981{
2982 struct module_string *modstr;
2983
2984 modstr = kmalloc(sizeof(*modstr), GFP_KERNEL);
2985
2986 /*
2987 * If we failed to allocate memory here, then we'll just
2988 * let the str memory leak when the module is removed.
2989 * If this fails to allocate, there's worse problems than
2990 * a leaked string on module removal.
2991 */
2992 if (WARN_ON_ONCE(!modstr))
2993 return;
2994
2995 modstr->module = module;
2996 modstr->str = str;
2997
2998 list_add(&modstr->next, &module_strings);
2999}
3000
3001static void update_event_fields(struct trace_event_call *call,
3002 struct trace_eval_map *map)
3003{
3004 struct ftrace_event_field *field;
3005 struct list_head *head;
3006 char *ptr;
3007 char *str;
3008 int len = strlen(map->eval_string);
3009
3010 /* Dynamic events should never have field maps */
3011 if (WARN_ON_ONCE(call->flags & TRACE_EVENT_FL_DYNAMIC))
3012 return;
3013
3014 head = trace_get_fields(call);
3015 list_for_each_entry(field, head, link) {
3016 ptr = strchr(field->type, '[');
3017 if (!ptr)
3018 continue;
3019 ptr++;
3020
3021 if (!isalpha(*ptr) && *ptr != '_')
3022 continue;
3023
3024 if (strncmp(map->eval_string, ptr, len) != 0)
3025 continue;
3026
3027 str = kstrdup(field->type, GFP_KERNEL);
3028 if (WARN_ON_ONCE(!str))
3029 return;
3030 ptr = str + (ptr - field->type);
3031 ptr = eval_replace(ptr, map, len);
3032 /* enum/sizeof string smaller than value */
3033 if (WARN_ON_ONCE(!ptr)) {
3034 kfree(str);
3035 continue;
3036 }
3037
3038 /*
3039 * If the event is part of a module, then we need to free the string
3040 * when the module is removed. Otherwise, it will stay allocated
3041 * until a reboot.
3042 */
3043 if (call->module)
3044 add_str_to_module(call->module, str);
3045
3046 field->type = str;
3047 }
3048}
3049
3050void trace_event_eval_update(struct trace_eval_map **map, int len)
3051{
3052 struct trace_event_call *call, *p;
3053 const char *last_system = NULL;
3054 bool first = false;
3055 int last_i;
3056 int i;
3057
3058 down_write(&trace_event_sem);
3059 list_for_each_entry_safe(call, p, &ftrace_events, list) {
3060 /* events are usually grouped together with systems */
3061 if (!last_system || call->class->system != last_system) {
3062 first = true;
3063 last_i = 0;
3064 last_system = call->class->system;
3065 }
3066
3067 /*
3068 * Since calls are grouped by systems, the likelihood that the
3069 * next call in the iteration belongs to the same system as the
3070 * previous call is high. As an optimization, we skip searching
3071 * for a map[] that matches the call's system if the last call
3072 * was from the same system. That's what last_i is for. If the
3073 * call has the same system as the previous call, then last_i
3074 * will be the index of the first map[] that has a matching
3075 * system.
3076 */
3077 for (i = last_i; i < len; i++) {
3078 if (call->class->system == map[i]->system) {
3079 /* Save the first system if need be */
3080 if (first) {
3081 last_i = i;
3082 first = false;
3083 }
3084 update_event_printk(call, map[i]);
3085 update_event_fields(call, map[i]);
3086 }
3087 }
3088 cond_resched();
3089 }
3090 up_write(&trace_event_sem);
3091}
3092
3093static bool event_in_systems(struct trace_event_call *call,
3094 const char *systems)
3095{
3096 const char *system;
3097 const char *p;
3098
3099 if (!systems)
3100 return true;
3101
3102 system = call->class->system;
3103 p = strstr(systems, system);
3104 if (!p)
3105 return false;
3106
3107 if (p != systems && !isspace(*(p - 1)) && *(p - 1) != ',')
3108 return false;
3109
3110 p += strlen(system);
3111 return !*p || isspace(*p) || *p == ',';
3112}
3113
3114static struct trace_event_file *
3115trace_create_new_event(struct trace_event_call *call,
3116 struct trace_array *tr)
3117{
3118 struct trace_pid_list *no_pid_list;
3119 struct trace_pid_list *pid_list;
3120 struct trace_event_file *file;
3121 unsigned int first;
3122
3123 if (!event_in_systems(call, tr->system_names))
3124 return NULL;
3125
3126 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
3127 if (!file)
3128 return ERR_PTR(-ENOMEM);
3129
3130 pid_list = rcu_dereference_protected(tr->filtered_pids,
3131 lockdep_is_held(&event_mutex));
3132 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
3133 lockdep_is_held(&event_mutex));
3134
3135 if (!trace_pid_list_first(pid_list, &first) ||
3136 !trace_pid_list_first(no_pid_list, &first))
3137 file->flags |= EVENT_FILE_FL_PID_FILTER;
3138
3139 file->event_call = call;
3140 file->tr = tr;
3141 atomic_set(&file->sm_ref, 0);
3142 atomic_set(&file->tm_ref, 0);
3143 INIT_LIST_HEAD(&file->triggers);
3144 list_add(&file->list, &tr->events);
3145 refcount_set(&file->ref, 1);
3146
3147 return file;
3148}
3149
3150#define MAX_BOOT_TRIGGERS 32
3151
3152static struct boot_triggers {
3153 const char *event;
3154 char *trigger;
3155} bootup_triggers[MAX_BOOT_TRIGGERS];
3156
3157static char bootup_trigger_buf[COMMAND_LINE_SIZE];
3158static int nr_boot_triggers;
3159
3160static __init int setup_trace_triggers(char *str)
3161{
3162 char *trigger;
3163 char *buf;
3164 int i;
3165
3166 strscpy(bootup_trigger_buf, str, COMMAND_LINE_SIZE);
3167 trace_set_ring_buffer_expanded(NULL);
3168 disable_tracing_selftest("running event triggers");
3169
3170 buf = bootup_trigger_buf;
3171 for (i = 0; i < MAX_BOOT_TRIGGERS; i++) {
3172 trigger = strsep(&buf, ",");
3173 if (!trigger)
3174 break;
3175 bootup_triggers[i].event = strsep(&trigger, ".");
3176 bootup_triggers[i].trigger = trigger;
3177 if (!bootup_triggers[i].trigger)
3178 break;
3179 }
3180
3181 nr_boot_triggers = i;
3182 return 1;
3183}
3184__setup("trace_trigger=", setup_trace_triggers);
3185
3186/* Add an event to a trace directory */
3187static int
3188__trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
3189{
3190 struct trace_event_file *file;
3191
3192 file = trace_create_new_event(call, tr);
3193 /*
3194 * trace_create_new_event() returns ERR_PTR(-ENOMEM) if failed
3195 * allocation, or NULL if the event is not part of the tr->system_names.
3196 * When the event is not part of the tr->system_names, return zero, not
3197 * an error.
3198 */
3199 if (!file)
3200 return 0;
3201
3202 if (IS_ERR(file))
3203 return PTR_ERR(file);
3204
3205 if (eventdir_initialized)
3206 return event_create_dir(tr->event_dir, file);
3207 else
3208 return event_define_fields(call);
3209}
3210
3211static void trace_early_triggers(struct trace_event_file *file, const char *name)
3212{
3213 int ret;
3214 int i;
3215
3216 for (i = 0; i < nr_boot_triggers; i++) {
3217 if (strcmp(name, bootup_triggers[i].event))
3218 continue;
3219 mutex_lock(&event_mutex);
3220 ret = trigger_process_regex(file, bootup_triggers[i].trigger);
3221 mutex_unlock(&event_mutex);
3222 if (ret)
3223 pr_err("Failed to register trigger '%s' on event %s\n",
3224 bootup_triggers[i].trigger,
3225 bootup_triggers[i].event);
3226 }
3227}
3228
3229/*
3230 * Just create a descriptor for early init. A descriptor is required
3231 * for enabling events at boot. We want to enable events before
3232 * the filesystem is initialized.
3233 */
3234static int
3235__trace_early_add_new_event(struct trace_event_call *call,
3236 struct trace_array *tr)
3237{
3238 struct trace_event_file *file;
3239 int ret;
3240
3241 file = trace_create_new_event(call, tr);
3242 /*
3243 * trace_create_new_event() returns ERR_PTR(-ENOMEM) if failed
3244 * allocation, or NULL if the event is not part of the tr->system_names.
3245 * When the event is not part of the tr->system_names, return zero, not
3246 * an error.
3247 */
3248 if (!file)
3249 return 0;
3250
3251 if (IS_ERR(file))
3252 return PTR_ERR(file);
3253
3254 ret = event_define_fields(call);
3255 if (ret)
3256 return ret;
3257
3258 trace_early_triggers(file, trace_event_name(call));
3259
3260 return 0;
3261}
3262
3263struct ftrace_module_file_ops;
3264static void __add_event_to_tracers(struct trace_event_call *call);
3265
3266/* Add an additional event_call dynamically */
3267int trace_add_event_call(struct trace_event_call *call)
3268{
3269 int ret;
3270 lockdep_assert_held(&event_mutex);
3271
3272 mutex_lock(&trace_types_lock);
3273
3274 ret = __register_event(call, NULL);
3275 if (ret >= 0)
3276 __add_event_to_tracers(call);
3277
3278 mutex_unlock(&trace_types_lock);
3279 return ret;
3280}
3281EXPORT_SYMBOL_GPL(trace_add_event_call);
3282
3283/*
3284 * Must be called under locking of trace_types_lock, event_mutex and
3285 * trace_event_sem.
3286 */
3287static void __trace_remove_event_call(struct trace_event_call *call)
3288{
3289 event_remove(call);
3290 trace_destroy_fields(call);
3291}
3292
3293static int probe_remove_event_call(struct trace_event_call *call)
3294{
3295 struct trace_array *tr;
3296 struct trace_event_file *file;
3297
3298#ifdef CONFIG_PERF_EVENTS
3299 if (call->perf_refcount)
3300 return -EBUSY;
3301#endif
3302 do_for_each_event_file(tr, file) {
3303 if (file->event_call != call)
3304 continue;
3305 /*
3306 * We can't rely on ftrace_event_enable_disable(enable => 0)
3307 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
3308 * TRACE_REG_UNREGISTER.
3309 */
3310 if (file->flags & EVENT_FILE_FL_ENABLED)
3311 goto busy;
3312
3313 if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
3314 tr->clear_trace = true;
3315 /*
3316 * The do_for_each_event_file_safe() is
3317 * a double loop. After finding the call for this
3318 * trace_array, we use break to jump to the next
3319 * trace_array.
3320 */
3321 break;
3322 } while_for_each_event_file();
3323
3324 __trace_remove_event_call(call);
3325
3326 return 0;
3327 busy:
3328 /* No need to clear the trace now */
3329 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
3330 tr->clear_trace = false;
3331 }
3332 return -EBUSY;
3333}
3334
3335/* Remove an event_call */
3336int trace_remove_event_call(struct trace_event_call *call)
3337{
3338 int ret;
3339
3340 lockdep_assert_held(&event_mutex);
3341
3342 mutex_lock(&trace_types_lock);
3343 down_write(&trace_event_sem);
3344 ret = probe_remove_event_call(call);
3345 up_write(&trace_event_sem);
3346 mutex_unlock(&trace_types_lock);
3347
3348 return ret;
3349}
3350EXPORT_SYMBOL_GPL(trace_remove_event_call);
3351
3352#define for_each_event(event, start, end) \
3353 for (event = start; \
3354 (unsigned long)event < (unsigned long)end; \
3355 event++)
3356
3357#ifdef CONFIG_MODULES
3358
3359static void trace_module_add_events(struct module *mod)
3360{
3361 struct trace_event_call **call, **start, **end;
3362
3363 if (!mod->num_trace_events)
3364 return;
3365
3366 /* Don't add infrastructure for mods without tracepoints */
3367 if (trace_module_has_bad_taint(mod)) {
3368 pr_err("%s: module has bad taint, not creating trace events\n",
3369 mod->name);
3370 return;
3371 }
3372
3373 start = mod->trace_events;
3374 end = mod->trace_events + mod->num_trace_events;
3375
3376 for_each_event(call, start, end) {
3377 __register_event(*call, mod);
3378 __add_event_to_tracers(*call);
3379 }
3380}
3381
3382static void trace_module_remove_events(struct module *mod)
3383{
3384 struct trace_event_call *call, *p;
3385 struct module_string *modstr, *m;
3386
3387 down_write(&trace_event_sem);
3388 list_for_each_entry_safe(call, p, &ftrace_events, list) {
3389 if ((call->flags & TRACE_EVENT_FL_DYNAMIC) || !call->module)
3390 continue;
3391 if (call->module == mod)
3392 __trace_remove_event_call(call);
3393 }
3394 /* Check for any strings allocade for this module */
3395 list_for_each_entry_safe(modstr, m, &module_strings, next) {
3396 if (modstr->module != mod)
3397 continue;
3398 list_del(&modstr->next);
3399 kfree(modstr->str);
3400 kfree(modstr);
3401 }
3402 up_write(&trace_event_sem);
3403
3404 /*
3405 * It is safest to reset the ring buffer if the module being unloaded
3406 * registered any events that were used. The only worry is if
3407 * a new module gets loaded, and takes on the same id as the events
3408 * of this module. When printing out the buffer, traced events left
3409 * over from this module may be passed to the new module events and
3410 * unexpected results may occur.
3411 */
3412 tracing_reset_all_online_cpus_unlocked();
3413}
3414
3415static int trace_module_notify(struct notifier_block *self,
3416 unsigned long val, void *data)
3417{
3418 struct module *mod = data;
3419
3420 mutex_lock(&event_mutex);
3421 mutex_lock(&trace_types_lock);
3422 switch (val) {
3423 case MODULE_STATE_COMING:
3424 trace_module_add_events(mod);
3425 break;
3426 case MODULE_STATE_GOING:
3427 trace_module_remove_events(mod);
3428 break;
3429 }
3430 mutex_unlock(&trace_types_lock);
3431 mutex_unlock(&event_mutex);
3432
3433 return NOTIFY_OK;
3434}
3435
3436static struct notifier_block trace_module_nb = {
3437 .notifier_call = trace_module_notify,
3438 .priority = 1, /* higher than trace.c module notify */
3439};
3440#endif /* CONFIG_MODULES */
3441
3442/* Create a new event directory structure for a trace directory. */
3443static void
3444__trace_add_event_dirs(struct trace_array *tr)
3445{
3446 struct trace_event_call *call;
3447 int ret;
3448
3449 list_for_each_entry(call, &ftrace_events, list) {
3450 ret = __trace_add_new_event(call, tr);
3451 if (ret < 0)
3452 pr_warn("Could not create directory for event %s\n",
3453 trace_event_name(call));
3454 }
3455}
3456
3457/* Returns any file that matches the system and event */
3458struct trace_event_file *
3459__find_event_file(struct trace_array *tr, const char *system, const char *event)
3460{
3461 struct trace_event_file *file;
3462 struct trace_event_call *call;
3463 const char *name;
3464
3465 list_for_each_entry(file, &tr->events, list) {
3466
3467 call = file->event_call;
3468 name = trace_event_name(call);
3469
3470 if (!name || !call->class)
3471 continue;
3472
3473 if (strcmp(event, name) == 0 &&
3474 strcmp(system, call->class->system) == 0)
3475 return file;
3476 }
3477 return NULL;
3478}
3479
3480/* Returns valid trace event files that match system and event */
3481struct trace_event_file *
3482find_event_file(struct trace_array *tr, const char *system, const char *event)
3483{
3484 struct trace_event_file *file;
3485
3486 file = __find_event_file(tr, system, event);
3487 if (!file || !file->event_call->class->reg ||
3488 file->event_call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
3489 return NULL;
3490
3491 return file;
3492}
3493
3494/**
3495 * trace_get_event_file - Find and return a trace event file
3496 * @instance: The name of the trace instance containing the event
3497 * @system: The name of the system containing the event
3498 * @event: The name of the event
3499 *
3500 * Return a trace event file given the trace instance name, trace
3501 * system, and trace event name. If the instance name is NULL, it
3502 * refers to the top-level trace array.
3503 *
3504 * This function will look it up and return it if found, after calling
3505 * trace_array_get() to prevent the instance from going away, and
3506 * increment the event's module refcount to prevent it from being
3507 * removed.
3508 *
3509 * To release the file, call trace_put_event_file(), which will call
3510 * trace_array_put() and decrement the event's module refcount.
3511 *
3512 * Return: The trace event on success, ERR_PTR otherwise.
3513 */
3514struct trace_event_file *trace_get_event_file(const char *instance,
3515 const char *system,
3516 const char *event)
3517{
3518 struct trace_array *tr = top_trace_array();
3519 struct trace_event_file *file = NULL;
3520 int ret = -EINVAL;
3521
3522 if (instance) {
3523 tr = trace_array_find_get(instance);
3524 if (!tr)
3525 return ERR_PTR(-ENOENT);
3526 } else {
3527 ret = trace_array_get(tr);
3528 if (ret)
3529 return ERR_PTR(ret);
3530 }
3531
3532 mutex_lock(&event_mutex);
3533
3534 file = find_event_file(tr, system, event);
3535 if (!file) {
3536 trace_array_put(tr);
3537 ret = -EINVAL;
3538 goto out;
3539 }
3540
3541 /* Don't let event modules unload while in use */
3542 ret = trace_event_try_get_ref(file->event_call);
3543 if (!ret) {
3544 trace_array_put(tr);
3545 ret = -EBUSY;
3546 goto out;
3547 }
3548
3549 ret = 0;
3550 out:
3551 mutex_unlock(&event_mutex);
3552
3553 if (ret)
3554 file = ERR_PTR(ret);
3555
3556 return file;
3557}
3558EXPORT_SYMBOL_GPL(trace_get_event_file);
3559
3560/**
3561 * trace_put_event_file - Release a file from trace_get_event_file()
3562 * @file: The trace event file
3563 *
3564 * If a file was retrieved using trace_get_event_file(), this should
3565 * be called when it's no longer needed. It will cancel the previous
3566 * trace_array_get() called by that function, and decrement the
3567 * event's module refcount.
3568 */
3569void trace_put_event_file(struct trace_event_file *file)
3570{
3571 mutex_lock(&event_mutex);
3572 trace_event_put_ref(file->event_call);
3573 mutex_unlock(&event_mutex);
3574
3575 trace_array_put(file->tr);
3576}
3577EXPORT_SYMBOL_GPL(trace_put_event_file);
3578
3579#ifdef CONFIG_DYNAMIC_FTRACE
3580
3581/* Avoid typos */
3582#define ENABLE_EVENT_STR "enable_event"
3583#define DISABLE_EVENT_STR "disable_event"
3584
3585struct event_probe_data {
3586 struct trace_event_file *file;
3587 unsigned long count;
3588 int ref;
3589 bool enable;
3590};
3591
3592static void update_event_probe(struct event_probe_data *data)
3593{
3594 if (data->enable)
3595 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
3596 else
3597 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
3598}
3599
3600static void
3601event_enable_probe(unsigned long ip, unsigned long parent_ip,
3602 struct trace_array *tr, struct ftrace_probe_ops *ops,
3603 void *data)
3604{
3605 struct ftrace_func_mapper *mapper = data;
3606 struct event_probe_data *edata;
3607 void **pdata;
3608
3609 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3610 if (!pdata || !*pdata)
3611 return;
3612
3613 edata = *pdata;
3614 update_event_probe(edata);
3615}
3616
3617static void
3618event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
3619 struct trace_array *tr, struct ftrace_probe_ops *ops,
3620 void *data)
3621{
3622 struct ftrace_func_mapper *mapper = data;
3623 struct event_probe_data *edata;
3624 void **pdata;
3625
3626 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3627 if (!pdata || !*pdata)
3628 return;
3629
3630 edata = *pdata;
3631
3632 if (!edata->count)
3633 return;
3634
3635 /* Skip if the event is in a state we want to switch to */
3636 if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
3637 return;
3638
3639 if (edata->count != -1)
3640 (edata->count)--;
3641
3642 update_event_probe(edata);
3643}
3644
3645static int
3646event_enable_print(struct seq_file *m, unsigned long ip,
3647 struct ftrace_probe_ops *ops, void *data)
3648{
3649 struct ftrace_func_mapper *mapper = data;
3650 struct event_probe_data *edata;
3651 void **pdata;
3652
3653 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3654
3655 if (WARN_ON_ONCE(!pdata || !*pdata))
3656 return 0;
3657
3658 edata = *pdata;
3659
3660 seq_printf(m, "%ps:", (void *)ip);
3661
3662 seq_printf(m, "%s:%s:%s",
3663 edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
3664 edata->file->event_call->class->system,
3665 trace_event_name(edata->file->event_call));
3666
3667 if (edata->count == -1)
3668 seq_puts(m, ":unlimited\n");
3669 else
3670 seq_printf(m, ":count=%ld\n", edata->count);
3671
3672 return 0;
3673}
3674
3675static int
3676event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
3677 unsigned long ip, void *init_data, void **data)
3678{
3679 struct ftrace_func_mapper *mapper = *data;
3680 struct event_probe_data *edata = init_data;
3681 int ret;
3682
3683 if (!mapper) {
3684 mapper = allocate_ftrace_func_mapper();
3685 if (!mapper)
3686 return -ENODEV;
3687 *data = mapper;
3688 }
3689
3690 ret = ftrace_func_mapper_add_ip(mapper, ip, edata);
3691 if (ret < 0)
3692 return ret;
3693
3694 edata->ref++;
3695
3696 return 0;
3697}
3698
3699static int free_probe_data(void *data)
3700{
3701 struct event_probe_data *edata = data;
3702
3703 edata->ref--;
3704 if (!edata->ref) {
3705 /* Remove the SOFT_MODE flag */
3706 __ftrace_event_enable_disable(edata->file, 0, 1);
3707 trace_event_put_ref(edata->file->event_call);
3708 kfree(edata);
3709 }
3710 return 0;
3711}
3712
3713static void
3714event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
3715 unsigned long ip, void *data)
3716{
3717 struct ftrace_func_mapper *mapper = data;
3718 struct event_probe_data *edata;
3719
3720 if (!ip) {
3721 if (!mapper)
3722 return;
3723 free_ftrace_func_mapper(mapper, free_probe_data);
3724 return;
3725 }
3726
3727 edata = ftrace_func_mapper_remove_ip(mapper, ip);
3728
3729 if (WARN_ON_ONCE(!edata))
3730 return;
3731
3732 if (WARN_ON_ONCE(edata->ref <= 0))
3733 return;
3734
3735 free_probe_data(edata);
3736}
3737
3738static struct ftrace_probe_ops event_enable_probe_ops = {
3739 .func = event_enable_probe,
3740 .print = event_enable_print,
3741 .init = event_enable_init,
3742 .free = event_enable_free,
3743};
3744
3745static struct ftrace_probe_ops event_enable_count_probe_ops = {
3746 .func = event_enable_count_probe,
3747 .print = event_enable_print,
3748 .init = event_enable_init,
3749 .free = event_enable_free,
3750};
3751
3752static struct ftrace_probe_ops event_disable_probe_ops = {
3753 .func = event_enable_probe,
3754 .print = event_enable_print,
3755 .init = event_enable_init,
3756 .free = event_enable_free,
3757};
3758
3759static struct ftrace_probe_ops event_disable_count_probe_ops = {
3760 .func = event_enable_count_probe,
3761 .print = event_enable_print,
3762 .init = event_enable_init,
3763 .free = event_enable_free,
3764};
3765
3766static int
3767event_enable_func(struct trace_array *tr, struct ftrace_hash *hash,
3768 char *glob, char *cmd, char *param, int enabled)
3769{
3770 struct trace_event_file *file;
3771 struct ftrace_probe_ops *ops;
3772 struct event_probe_data *data;
3773 const char *system;
3774 const char *event;
3775 char *number;
3776 bool enable;
3777 int ret;
3778
3779 if (!tr)
3780 return -ENODEV;
3781
3782 /* hash funcs only work with set_ftrace_filter */
3783 if (!enabled || !param)
3784 return -EINVAL;
3785
3786 system = strsep(¶m, ":");
3787 if (!param)
3788 return -EINVAL;
3789
3790 event = strsep(¶m, ":");
3791
3792 mutex_lock(&event_mutex);
3793
3794 ret = -EINVAL;
3795 file = find_event_file(tr, system, event);
3796 if (!file)
3797 goto out;
3798
3799 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
3800
3801 if (enable)
3802 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
3803 else
3804 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
3805
3806 if (glob[0] == '!') {
3807 ret = unregister_ftrace_function_probe_func(glob+1, tr, ops);
3808 goto out;
3809 }
3810
3811 ret = -ENOMEM;
3812
3813 data = kzalloc(sizeof(*data), GFP_KERNEL);
3814 if (!data)
3815 goto out;
3816
3817 data->enable = enable;
3818 data->count = -1;
3819 data->file = file;
3820
3821 if (!param)
3822 goto out_reg;
3823
3824 number = strsep(¶m, ":");
3825
3826 ret = -EINVAL;
3827 if (!strlen(number))
3828 goto out_free;
3829
3830 /*
3831 * We use the callback data field (which is a pointer)
3832 * as our counter.
3833 */
3834 ret = kstrtoul(number, 0, &data->count);
3835 if (ret)
3836 goto out_free;
3837
3838 out_reg:
3839 /* Don't let event modules unload while probe registered */
3840 ret = trace_event_try_get_ref(file->event_call);
3841 if (!ret) {
3842 ret = -EBUSY;
3843 goto out_free;
3844 }
3845
3846 ret = __ftrace_event_enable_disable(file, 1, 1);
3847 if (ret < 0)
3848 goto out_put;
3849
3850 ret = register_ftrace_function_probe(glob, tr, ops, data);
3851 /*
3852 * The above returns on success the # of functions enabled,
3853 * but if it didn't find any functions it returns zero.
3854 * Consider no functions a failure too.
3855 */
3856 if (!ret) {
3857 ret = -ENOENT;
3858 goto out_disable;
3859 } else if (ret < 0)
3860 goto out_disable;
3861 /* Just return zero, not the number of enabled functions */
3862 ret = 0;
3863 out:
3864 mutex_unlock(&event_mutex);
3865 return ret;
3866
3867 out_disable:
3868 __ftrace_event_enable_disable(file, 0, 1);
3869 out_put:
3870 trace_event_put_ref(file->event_call);
3871 out_free:
3872 kfree(data);
3873 goto out;
3874}
3875
3876static struct ftrace_func_command event_enable_cmd = {
3877 .name = ENABLE_EVENT_STR,
3878 .func = event_enable_func,
3879};
3880
3881static struct ftrace_func_command event_disable_cmd = {
3882 .name = DISABLE_EVENT_STR,
3883 .func = event_enable_func,
3884};
3885
3886static __init int register_event_cmds(void)
3887{
3888 int ret;
3889
3890 ret = register_ftrace_command(&event_enable_cmd);
3891 if (WARN_ON(ret < 0))
3892 return ret;
3893 ret = register_ftrace_command(&event_disable_cmd);
3894 if (WARN_ON(ret < 0))
3895 unregister_ftrace_command(&event_enable_cmd);
3896 return ret;
3897}
3898#else
3899static inline int register_event_cmds(void) { return 0; }
3900#endif /* CONFIG_DYNAMIC_FTRACE */
3901
3902/*
3903 * The top level array and trace arrays created by boot-time tracing
3904 * have already had its trace_event_file descriptors created in order
3905 * to allow for early events to be recorded.
3906 * This function is called after the tracefs has been initialized,
3907 * and we now have to create the files associated to the events.
3908 */
3909static void __trace_early_add_event_dirs(struct trace_array *tr)
3910{
3911 struct trace_event_file *file;
3912 int ret;
3913
3914
3915 list_for_each_entry(file, &tr->events, list) {
3916 ret = event_create_dir(tr->event_dir, file);
3917 if (ret < 0)
3918 pr_warn("Could not create directory for event %s\n",
3919 trace_event_name(file->event_call));
3920 }
3921}
3922
3923/*
3924 * For early boot up, the top trace array and the trace arrays created
3925 * by boot-time tracing require to have a list of events that can be
3926 * enabled. This must be done before the filesystem is set up in order
3927 * to allow events to be traced early.
3928 */
3929void __trace_early_add_events(struct trace_array *tr)
3930{
3931 struct trace_event_call *call;
3932 int ret;
3933
3934 list_for_each_entry(call, &ftrace_events, list) {
3935 /* Early boot up should not have any modules loaded */
3936 if (!(call->flags & TRACE_EVENT_FL_DYNAMIC) &&
3937 WARN_ON_ONCE(call->module))
3938 continue;
3939
3940 ret = __trace_early_add_new_event(call, tr);
3941 if (ret < 0)
3942 pr_warn("Could not create early event %s\n",
3943 trace_event_name(call));
3944 }
3945}
3946
3947/* Remove the event directory structure for a trace directory. */
3948static void
3949__trace_remove_event_dirs(struct trace_array *tr)
3950{
3951 struct trace_event_file *file, *next;
3952
3953 list_for_each_entry_safe(file, next, &tr->events, list)
3954 remove_event_file_dir(file);
3955}
3956
3957static void __add_event_to_tracers(struct trace_event_call *call)
3958{
3959 struct trace_array *tr;
3960
3961 list_for_each_entry(tr, &ftrace_trace_arrays, list)
3962 __trace_add_new_event(call, tr);
3963}
3964
3965extern struct trace_event_call *__start_ftrace_events[];
3966extern struct trace_event_call *__stop_ftrace_events[];
3967
3968static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
3969
3970static __init int setup_trace_event(char *str)
3971{
3972 strscpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
3973 trace_set_ring_buffer_expanded(NULL);
3974 disable_tracing_selftest("running event tracing");
3975
3976 return 1;
3977}
3978__setup("trace_event=", setup_trace_event);
3979
3980static int events_callback(const char *name, umode_t *mode, void **data,
3981 const struct file_operations **fops)
3982{
3983 if (strcmp(name, "enable") == 0) {
3984 *mode = TRACE_MODE_WRITE;
3985 *fops = &ftrace_tr_enable_fops;
3986 return 1;
3987 }
3988
3989 if (strcmp(name, "header_page") == 0) {
3990 *mode = TRACE_MODE_READ;
3991 *fops = &ftrace_show_header_page_fops;
3992
3993 } else if (strcmp(name, "header_event") == 0) {
3994 *mode = TRACE_MODE_READ;
3995 *fops = &ftrace_show_header_event_fops;
3996 } else
3997 return 0;
3998
3999 return 1;
4000}
4001
4002/* Expects to have event_mutex held when called */
4003static int
4004create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
4005{
4006 struct eventfs_inode *e_events;
4007 struct dentry *entry;
4008 int nr_entries;
4009 static struct eventfs_entry events_entries[] = {
4010 {
4011 .name = "enable",
4012 .callback = events_callback,
4013 },
4014 {
4015 .name = "header_page",
4016 .callback = events_callback,
4017 },
4018 {
4019 .name = "header_event",
4020 .callback = events_callback,
4021 },
4022 };
4023
4024 entry = trace_create_file("set_event", TRACE_MODE_WRITE, parent,
4025 tr, &ftrace_set_event_fops);
4026 if (!entry)
4027 return -ENOMEM;
4028
4029 nr_entries = ARRAY_SIZE(events_entries);
4030
4031 e_events = eventfs_create_events_dir("events", parent, events_entries,
4032 nr_entries, tr);
4033 if (IS_ERR(e_events)) {
4034 pr_warn("Could not create tracefs 'events' directory\n");
4035 return -ENOMEM;
4036 }
4037
4038 /* There are not as crucial, just warn if they are not created */
4039
4040 trace_create_file("set_event_pid", TRACE_MODE_WRITE, parent,
4041 tr, &ftrace_set_event_pid_fops);
4042
4043 trace_create_file("set_event_notrace_pid",
4044 TRACE_MODE_WRITE, parent, tr,
4045 &ftrace_set_event_notrace_pid_fops);
4046
4047 tr->event_dir = e_events;
4048
4049 return 0;
4050}
4051
4052/**
4053 * event_trace_add_tracer - add a instance of a trace_array to events
4054 * @parent: The parent dentry to place the files/directories for events in
4055 * @tr: The trace array associated with these events
4056 *
4057 * When a new instance is created, it needs to set up its events
4058 * directory, as well as other files associated with events. It also
4059 * creates the event hierarchy in the @parent/events directory.
4060 *
4061 * Returns 0 on success.
4062 *
4063 * Must be called with event_mutex held.
4064 */
4065int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
4066{
4067 int ret;
4068
4069 lockdep_assert_held(&event_mutex);
4070
4071 ret = create_event_toplevel_files(parent, tr);
4072 if (ret)
4073 goto out;
4074
4075 down_write(&trace_event_sem);
4076 /* If tr already has the event list, it is initialized in early boot. */
4077 if (unlikely(!list_empty(&tr->events)))
4078 __trace_early_add_event_dirs(tr);
4079 else
4080 __trace_add_event_dirs(tr);
4081 up_write(&trace_event_sem);
4082
4083 out:
4084 return ret;
4085}
4086
4087/*
4088 * The top trace array already had its file descriptors created.
4089 * Now the files themselves need to be created.
4090 */
4091static __init int
4092early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
4093{
4094 int ret;
4095
4096 mutex_lock(&event_mutex);
4097
4098 ret = create_event_toplevel_files(parent, tr);
4099 if (ret)
4100 goto out_unlock;
4101
4102 down_write(&trace_event_sem);
4103 __trace_early_add_event_dirs(tr);
4104 up_write(&trace_event_sem);
4105
4106 out_unlock:
4107 mutex_unlock(&event_mutex);
4108
4109 return ret;
4110}
4111
4112/* Must be called with event_mutex held */
4113int event_trace_del_tracer(struct trace_array *tr)
4114{
4115 lockdep_assert_held(&event_mutex);
4116
4117 /* Disable any event triggers and associated soft-disabled events */
4118 clear_event_triggers(tr);
4119
4120 /* Clear the pid list */
4121 __ftrace_clear_event_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
4122
4123 /* Disable any running events */
4124 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
4125
4126 /* Make sure no more events are being executed */
4127 tracepoint_synchronize_unregister();
4128
4129 down_write(&trace_event_sem);
4130 __trace_remove_event_dirs(tr);
4131 eventfs_remove_events_dir(tr->event_dir);
4132 up_write(&trace_event_sem);
4133
4134 tr->event_dir = NULL;
4135
4136 return 0;
4137}
4138
4139static __init int event_trace_memsetup(void)
4140{
4141 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
4142 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
4143 return 0;
4144}
4145
4146__init void
4147early_enable_events(struct trace_array *tr, char *buf, bool disable_first)
4148{
4149 char *token;
4150 int ret;
4151
4152 while (true) {
4153 token = strsep(&buf, ",");
4154
4155 if (!token)
4156 break;
4157
4158 if (*token) {
4159 /* Restarting syscalls requires that we stop them first */
4160 if (disable_first)
4161 ftrace_set_clr_event(tr, token, 0);
4162
4163 ret = ftrace_set_clr_event(tr, token, 1);
4164 if (ret)
4165 pr_warn("Failed to enable trace event: %s\n", token);
4166 }
4167
4168 /* Put back the comma to allow this to be called again */
4169 if (buf)
4170 *(buf - 1) = ',';
4171 }
4172}
4173
4174static __init int event_trace_enable(void)
4175{
4176 struct trace_array *tr = top_trace_array();
4177 struct trace_event_call **iter, *call;
4178 int ret;
4179
4180 if (!tr)
4181 return -ENODEV;
4182
4183 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
4184
4185 call = *iter;
4186 ret = event_init(call);
4187 if (!ret)
4188 list_add(&call->list, &ftrace_events);
4189 }
4190
4191 register_trigger_cmds();
4192
4193 /*
4194 * We need the top trace array to have a working set of trace
4195 * points at early init, before the debug files and directories
4196 * are created. Create the file entries now, and attach them
4197 * to the actual file dentries later.
4198 */
4199 __trace_early_add_events(tr);
4200
4201 early_enable_events(tr, bootup_event_buf, false);
4202
4203 trace_printk_start_comm();
4204
4205 register_event_cmds();
4206
4207
4208 return 0;
4209}
4210
4211/*
4212 * event_trace_enable() is called from trace_event_init() first to
4213 * initialize events and perhaps start any events that are on the
4214 * command line. Unfortunately, there are some events that will not
4215 * start this early, like the system call tracepoints that need
4216 * to set the %SYSCALL_WORK_SYSCALL_TRACEPOINT flag of pid 1. But
4217 * event_trace_enable() is called before pid 1 starts, and this flag
4218 * is never set, making the syscall tracepoint never get reached, but
4219 * the event is enabled regardless (and not doing anything).
4220 */
4221static __init int event_trace_enable_again(void)
4222{
4223 struct trace_array *tr;
4224
4225 tr = top_trace_array();
4226 if (!tr)
4227 return -ENODEV;
4228
4229 early_enable_events(tr, bootup_event_buf, true);
4230
4231 return 0;
4232}
4233
4234early_initcall(event_trace_enable_again);
4235
4236/* Init fields which doesn't related to the tracefs */
4237static __init int event_trace_init_fields(void)
4238{
4239 if (trace_define_generic_fields())
4240 pr_warn("tracing: Failed to allocated generic fields");
4241
4242 if (trace_define_common_fields())
4243 pr_warn("tracing: Failed to allocate common fields");
4244
4245 return 0;
4246}
4247
4248__init int event_trace_init(void)
4249{
4250 struct trace_array *tr;
4251 int ret;
4252
4253 tr = top_trace_array();
4254 if (!tr)
4255 return -ENODEV;
4256
4257 trace_create_file("available_events", TRACE_MODE_READ,
4258 NULL, tr, &ftrace_avail_fops);
4259
4260 ret = early_event_add_tracer(NULL, tr);
4261 if (ret)
4262 return ret;
4263
4264#ifdef CONFIG_MODULES
4265 ret = register_module_notifier(&trace_module_nb);
4266 if (ret)
4267 pr_warn("Failed to register trace events module notifier\n");
4268#endif
4269
4270 eventdir_initialized = true;
4271
4272 return 0;
4273}
4274
4275void __init trace_event_init(void)
4276{
4277 event_trace_memsetup();
4278 init_ftrace_syscalls();
4279 event_trace_enable();
4280 event_trace_init_fields();
4281}
4282
4283#ifdef CONFIG_EVENT_TRACE_STARTUP_TEST
4284
4285static DEFINE_SPINLOCK(test_spinlock);
4286static DEFINE_SPINLOCK(test_spinlock_irq);
4287static DEFINE_MUTEX(test_mutex);
4288
4289static __init void test_work(struct work_struct *dummy)
4290{
4291 spin_lock(&test_spinlock);
4292 spin_lock_irq(&test_spinlock_irq);
4293 udelay(1);
4294 spin_unlock_irq(&test_spinlock_irq);
4295 spin_unlock(&test_spinlock);
4296
4297 mutex_lock(&test_mutex);
4298 msleep(1);
4299 mutex_unlock(&test_mutex);
4300}
4301
4302static __init int event_test_thread(void *unused)
4303{
4304 void *test_malloc;
4305
4306 test_malloc = kmalloc(1234, GFP_KERNEL);
4307 if (!test_malloc)
4308 pr_info("failed to kmalloc\n");
4309
4310 schedule_on_each_cpu(test_work);
4311
4312 kfree(test_malloc);
4313
4314 set_current_state(TASK_INTERRUPTIBLE);
4315 while (!kthread_should_stop()) {
4316 schedule();
4317 set_current_state(TASK_INTERRUPTIBLE);
4318 }
4319 __set_current_state(TASK_RUNNING);
4320
4321 return 0;
4322}
4323
4324/*
4325 * Do various things that may trigger events.
4326 */
4327static __init void event_test_stuff(void)
4328{
4329 struct task_struct *test_thread;
4330
4331 test_thread = kthread_run(event_test_thread, NULL, "test-events");
4332 msleep(1);
4333 kthread_stop(test_thread);
4334}
4335
4336/*
4337 * For every trace event defined, we will test each trace point separately,
4338 * and then by groups, and finally all trace points.
4339 */
4340static __init void event_trace_self_tests(void)
4341{
4342 struct trace_subsystem_dir *dir;
4343 struct trace_event_file *file;
4344 struct trace_event_call *call;
4345 struct event_subsystem *system;
4346 struct trace_array *tr;
4347 int ret;
4348
4349 tr = top_trace_array();
4350 if (!tr)
4351 return;
4352
4353 pr_info("Running tests on trace events:\n");
4354
4355 list_for_each_entry(file, &tr->events, list) {
4356
4357 call = file->event_call;
4358
4359 /* Only test those that have a probe */
4360 if (!call->class || !call->class->probe)
4361 continue;
4362
4363/*
4364 * Testing syscall events here is pretty useless, but
4365 * we still do it if configured. But this is time consuming.
4366 * What we really need is a user thread to perform the
4367 * syscalls as we test.
4368 */
4369#ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
4370 if (call->class->system &&
4371 strcmp(call->class->system, "syscalls") == 0)
4372 continue;
4373#endif
4374
4375 pr_info("Testing event %s: ", trace_event_name(call));
4376
4377 /*
4378 * If an event is already enabled, someone is using
4379 * it and the self test should not be on.
4380 */
4381 if (file->flags & EVENT_FILE_FL_ENABLED) {
4382 pr_warn("Enabled event during self test!\n");
4383 WARN_ON_ONCE(1);
4384 continue;
4385 }
4386
4387 ftrace_event_enable_disable(file, 1);
4388 event_test_stuff();
4389 ftrace_event_enable_disable(file, 0);
4390
4391 pr_cont("OK\n");
4392 }
4393
4394 /* Now test at the sub system level */
4395
4396 pr_info("Running tests on trace event systems:\n");
4397
4398 list_for_each_entry(dir, &tr->systems, list) {
4399
4400 system = dir->subsystem;
4401
4402 /* the ftrace system is special, skip it */
4403 if (strcmp(system->name, "ftrace") == 0)
4404 continue;
4405
4406 pr_info("Testing event system %s: ", system->name);
4407
4408 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
4409 if (WARN_ON_ONCE(ret)) {
4410 pr_warn("error enabling system %s\n",
4411 system->name);
4412 continue;
4413 }
4414
4415 event_test_stuff();
4416
4417 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
4418 if (WARN_ON_ONCE(ret)) {
4419 pr_warn("error disabling system %s\n",
4420 system->name);
4421 continue;
4422 }
4423
4424 pr_cont("OK\n");
4425 }
4426
4427 /* Test with all events enabled */
4428
4429 pr_info("Running tests on all trace events:\n");
4430 pr_info("Testing all events: ");
4431
4432 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
4433 if (WARN_ON_ONCE(ret)) {
4434 pr_warn("error enabling all events\n");
4435 return;
4436 }
4437
4438 event_test_stuff();
4439
4440 /* reset sysname */
4441 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
4442 if (WARN_ON_ONCE(ret)) {
4443 pr_warn("error disabling all events\n");
4444 return;
4445 }
4446
4447 pr_cont("OK\n");
4448}
4449
4450#ifdef CONFIG_FUNCTION_TRACER
4451
4452static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
4453
4454static struct trace_event_file event_trace_file __initdata;
4455
4456static void __init
4457function_test_events_call(unsigned long ip, unsigned long parent_ip,
4458 struct ftrace_ops *op, struct ftrace_regs *regs)
4459{
4460 struct trace_buffer *buffer;
4461 struct ring_buffer_event *event;
4462 struct ftrace_entry *entry;
4463 unsigned int trace_ctx;
4464 long disabled;
4465 int cpu;
4466
4467 trace_ctx = tracing_gen_ctx();
4468 preempt_disable_notrace();
4469 cpu = raw_smp_processor_id();
4470 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
4471
4472 if (disabled != 1)
4473 goto out;
4474
4475 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
4476 TRACE_FN, sizeof(*entry),
4477 trace_ctx);
4478 if (!event)
4479 goto out;
4480 entry = ring_buffer_event_data(event);
4481 entry->ip = ip;
4482 entry->parent_ip = parent_ip;
4483
4484 event_trigger_unlock_commit(&event_trace_file, buffer, event,
4485 entry, trace_ctx);
4486 out:
4487 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
4488 preempt_enable_notrace();
4489}
4490
4491static struct ftrace_ops trace_ops __initdata =
4492{
4493 .func = function_test_events_call,
4494};
4495
4496static __init void event_trace_self_test_with_function(void)
4497{
4498 int ret;
4499
4500 event_trace_file.tr = top_trace_array();
4501 if (WARN_ON(!event_trace_file.tr))
4502 return;
4503
4504 ret = register_ftrace_function(&trace_ops);
4505 if (WARN_ON(ret < 0)) {
4506 pr_info("Failed to enable function tracer for event tests\n");
4507 return;
4508 }
4509 pr_info("Running tests again, along with the function tracer\n");
4510 event_trace_self_tests();
4511 unregister_ftrace_function(&trace_ops);
4512}
4513#else
4514static __init void event_trace_self_test_with_function(void)
4515{
4516}
4517#endif
4518
4519static __init int event_trace_self_tests_init(void)
4520{
4521 if (!tracing_selftest_disabled) {
4522 event_trace_self_tests();
4523 event_trace_self_test_with_function();
4524 }
4525
4526 return 0;
4527}
4528
4529late_initcall(event_trace_self_tests_init);
4530
4531#endif