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Merge tag 'trace-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt...
[people/ms/linux.git] / kernel / trace / trace_events.c
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
36 DEFINE_MUTEX(event_mutex);
37
38 LIST_HEAD(ftrace_events);
39 static LIST_HEAD(ftrace_generic_fields);
40 static LIST_HEAD(ftrace_common_fields);
41 static bool eventdir_initialized;
42
43 static LIST_HEAD(module_strings);
44
45 struct 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
53 static struct kmem_cache *field_cachep;
54 static struct kmem_cache *file_cachep;
55
56 static inline int system_refcount(struct event_subsystem *system)
57 {
58 return system->ref_count;
59 }
60
61 static int system_refcount_inc(struct event_subsystem *system)
62 {
63 return system->ref_count++;
64 }
65
66 static 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
84 static 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
97 struct ftrace_event_field *
98 trace_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
115 static 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)
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
137 list_add(&field->link, head);
138
139 return 0;
140 }
141
142 int trace_define_field(struct trace_event_call *call, const char *type,
143 const char *name, int offset, int size, int is_signed,
144 int filter_type)
145 {
146 struct list_head *head;
147
148 if (WARN_ON(!call->class))
149 return 0;
150
151 head = trace_get_fields(call);
152 return __trace_define_field(head, type, name, offset, size,
153 is_signed, filter_type);
154 }
155 EXPORT_SYMBOL_GPL(trace_define_field);
156
157 #define __generic_field(type, item, filter_type) \
158 ret = __trace_define_field(&ftrace_generic_fields, #type, \
159 #item, 0, 0, is_signed_type(type), \
160 filter_type); \
161 if (ret) \
162 return ret;
163
164 #define __common_field(type, item) \
165 ret = __trace_define_field(&ftrace_common_fields, #type, \
166 "common_" #item, \
167 offsetof(typeof(ent), item), \
168 sizeof(ent.item), \
169 is_signed_type(type), FILTER_OTHER); \
170 if (ret) \
171 return ret;
172
173 static int trace_define_generic_fields(void)
174 {
175 int ret;
176
177 __generic_field(int, CPU, FILTER_CPU);
178 __generic_field(int, cpu, FILTER_CPU);
179 __generic_field(char *, COMM, FILTER_COMM);
180 __generic_field(char *, comm, FILTER_COMM);
181
182 return ret;
183 }
184
185 static int trace_define_common_fields(void)
186 {
187 int ret;
188 struct trace_entry ent;
189
190 __common_field(unsigned short, type);
191 __common_field(unsigned char, flags);
192 /* Holds both preempt_count and migrate_disable */
193 __common_field(unsigned char, preempt_count);
194 __common_field(int, pid);
195
196 return ret;
197 }
198
199 static void trace_destroy_fields(struct trace_event_call *call)
200 {
201 struct ftrace_event_field *field, *next;
202 struct list_head *head;
203
204 head = trace_get_fields(call);
205 list_for_each_entry_safe(field, next, head, link) {
206 list_del(&field->link);
207 kmem_cache_free(field_cachep, field);
208 }
209 }
210
211 /*
212 * run-time version of trace_event_get_offsets_<call>() that returns the last
213 * accessible offset of trace fields excluding __dynamic_array bytes
214 */
215 int trace_event_get_offsets(struct trace_event_call *call)
216 {
217 struct ftrace_event_field *tail;
218 struct list_head *head;
219
220 head = trace_get_fields(call);
221 /*
222 * head->next points to the last field with the largest offset,
223 * since it was added last by trace_define_field()
224 */
225 tail = list_first_entry(head, struct ftrace_event_field, link);
226 return tail->offset + tail->size;
227 }
228
229 /*
230 * Check if the referenced field is an array and return true,
231 * as arrays are OK to dereference.
232 */
233 static bool test_field(const char *fmt, struct trace_event_call *call)
234 {
235 struct trace_event_fields *field = call->class->fields_array;
236 const char *array_descriptor;
237 const char *p = fmt;
238 int len;
239
240 if (!(len = str_has_prefix(fmt, "REC->")))
241 return false;
242 fmt += len;
243 for (p = fmt; *p; p++) {
244 if (!isalnum(*p) && *p != '_')
245 break;
246 }
247 len = p - fmt;
248
249 for (; field->type; field++) {
250 if (strncmp(field->name, fmt, len) ||
251 field->name[len])
252 continue;
253 array_descriptor = strchr(field->type, '[');
254 /* This is an array and is OK to dereference. */
255 return array_descriptor != NULL;
256 }
257 return false;
258 }
259
260 /*
261 * Examine the print fmt of the event looking for unsafe dereference
262 * pointers using %p* that could be recorded in the trace event and
263 * much later referenced after the pointer was freed. Dereferencing
264 * pointers are OK, if it is dereferenced into the event itself.
265 */
266 static void test_event_printk(struct trace_event_call *call)
267 {
268 u64 dereference_flags = 0;
269 bool first = true;
270 const char *fmt, *c, *r, *a;
271 int parens = 0;
272 char in_quote = 0;
273 int start_arg = 0;
274 int arg = 0;
275 int i;
276
277 fmt = call->print_fmt;
278
279 if (!fmt)
280 return;
281
282 for (i = 0; fmt[i]; i++) {
283 switch (fmt[i]) {
284 case '\\':
285 i++;
286 if (!fmt[i])
287 return;
288 continue;
289 case '"':
290 case '\'':
291 /*
292 * The print fmt starts with a string that
293 * is processed first to find %p* usage,
294 * then after the first string, the print fmt
295 * contains arguments that are used to check
296 * if the dereferenced %p* usage is safe.
297 */
298 if (first) {
299 if (fmt[i] == '\'')
300 continue;
301 if (in_quote) {
302 arg = 0;
303 first = false;
304 /*
305 * If there was no %p* uses
306 * the fmt is OK.
307 */
308 if (!dereference_flags)
309 return;
310 }
311 }
312 if (in_quote) {
313 if (in_quote == fmt[i])
314 in_quote = 0;
315 } else {
316 in_quote = fmt[i];
317 }
318 continue;
319 case '%':
320 if (!first || !in_quote)
321 continue;
322 i++;
323 if (!fmt[i])
324 return;
325 switch (fmt[i]) {
326 case '%':
327 continue;
328 case 'p':
329 /* Find dereferencing fields */
330 switch (fmt[i + 1]) {
331 case 'B': case 'R': case 'r':
332 case 'b': case 'M': case 'm':
333 case 'I': case 'i': case 'E':
334 case 'U': case 'V': case 'N':
335 case 'a': case 'd': case 'D':
336 case 'g': case 't': case 'C':
337 case 'O': case 'f':
338 if (WARN_ONCE(arg == 63,
339 "Too many args for event: %s",
340 trace_event_name(call)))
341 return;
342 dereference_flags |= 1ULL << arg;
343 }
344 break;
345 default:
346 {
347 bool star = false;
348 int j;
349
350 /* Increment arg if %*s exists. */
351 for (j = 0; fmt[i + j]; j++) {
352 if (isdigit(fmt[i + j]) ||
353 fmt[i + j] == '.')
354 continue;
355 if (fmt[i + j] == '*') {
356 star = true;
357 continue;
358 }
359 if ((fmt[i + j] == 's') && star)
360 arg++;
361 break;
362 }
363 break;
364 } /* default */
365
366 } /* switch */
367 arg++;
368 continue;
369 case '(':
370 if (in_quote)
371 continue;
372 parens++;
373 continue;
374 case ')':
375 if (in_quote)
376 continue;
377 parens--;
378 if (WARN_ONCE(parens < 0,
379 "Paren mismatch for event: %s\narg='%s'\n%*s",
380 trace_event_name(call),
381 fmt + start_arg,
382 (i - start_arg) + 5, "^"))
383 return;
384 continue;
385 case ',':
386 if (in_quote || parens)
387 continue;
388 i++;
389 while (isspace(fmt[i]))
390 i++;
391 start_arg = i;
392 if (!(dereference_flags & (1ULL << arg)))
393 goto next_arg;
394
395 /* Find the REC-> in the argument */
396 c = strchr(fmt + i, ',');
397 r = strstr(fmt + i, "REC->");
398 if (r && (!c || r < c)) {
399 /*
400 * Addresses of events on the buffer,
401 * or an array on the buffer is
402 * OK to dereference.
403 * There's ways to fool this, but
404 * this is to catch common mistakes,
405 * not malicious code.
406 */
407 a = strchr(fmt + i, '&');
408 if ((a && (a < r)) || test_field(r, call))
409 dereference_flags &= ~(1ULL << arg);
410 } else if ((r = strstr(fmt + i, "__get_dynamic_array(")) &&
411 (!c || r < c)) {
412 dereference_flags &= ~(1ULL << arg);
413 } else if ((r = strstr(fmt + i, "__get_sockaddr(")) &&
414 (!c || r < c)) {
415 dereference_flags &= ~(1ULL << arg);
416 }
417
418 next_arg:
419 i--;
420 arg++;
421 }
422 }
423
424 /*
425 * If you triggered the below warning, the trace event reported
426 * uses an unsafe dereference pointer %p*. As the data stored
427 * at the trace event time may no longer exist when the trace
428 * event is printed, dereferencing to the original source is
429 * unsafe. The source of the dereference must be copied into the
430 * event itself, and the dereference must access the copy instead.
431 */
432 if (WARN_ON_ONCE(dereference_flags)) {
433 arg = 1;
434 while (!(dereference_flags & 1)) {
435 dereference_flags >>= 1;
436 arg++;
437 }
438 pr_warn("event %s has unsafe dereference of argument %d\n",
439 trace_event_name(call), arg);
440 pr_warn("print_fmt: %s\n", fmt);
441 }
442 }
443
444 int trace_event_raw_init(struct trace_event_call *call)
445 {
446 int id;
447
448 id = register_trace_event(&call->event);
449 if (!id)
450 return -ENODEV;
451
452 test_event_printk(call);
453
454 return 0;
455 }
456 EXPORT_SYMBOL_GPL(trace_event_raw_init);
457
458 bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
459 {
460 struct trace_array *tr = trace_file->tr;
461 struct trace_array_cpu *data;
462 struct trace_pid_list *no_pid_list;
463 struct trace_pid_list *pid_list;
464
465 pid_list = rcu_dereference_raw(tr->filtered_pids);
466 no_pid_list = rcu_dereference_raw(tr->filtered_no_pids);
467
468 if (!pid_list && !no_pid_list)
469 return false;
470
471 data = this_cpu_ptr(tr->array_buffer.data);
472
473 return data->ignore_pid;
474 }
475 EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
476
477 void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
478 struct trace_event_file *trace_file,
479 unsigned long len)
480 {
481 struct trace_event_call *event_call = trace_file->event_call;
482
483 if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
484 trace_event_ignore_this_pid(trace_file))
485 return NULL;
486
487 /*
488 * If CONFIG_PREEMPTION is enabled, then the tracepoint itself disables
489 * preemption (adding one to the preempt_count). Since we are
490 * interested in the preempt_count at the time the tracepoint was
491 * hit, we need to subtract one to offset the increment.
492 */
493 fbuffer->trace_ctx = tracing_gen_ctx_dec();
494 fbuffer->trace_file = trace_file;
495
496 fbuffer->event =
497 trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
498 event_call->event.type, len,
499 fbuffer->trace_ctx);
500 if (!fbuffer->event)
501 return NULL;
502
503 fbuffer->regs = NULL;
504 fbuffer->entry = ring_buffer_event_data(fbuffer->event);
505 return fbuffer->entry;
506 }
507 EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
508
509 int trace_event_reg(struct trace_event_call *call,
510 enum trace_reg type, void *data)
511 {
512 struct trace_event_file *file = data;
513
514 WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
515 switch (type) {
516 case TRACE_REG_REGISTER:
517 return tracepoint_probe_register(call->tp,
518 call->class->probe,
519 file);
520 case TRACE_REG_UNREGISTER:
521 tracepoint_probe_unregister(call->tp,
522 call->class->probe,
523 file);
524 return 0;
525
526 #ifdef CONFIG_PERF_EVENTS
527 case TRACE_REG_PERF_REGISTER:
528 return tracepoint_probe_register(call->tp,
529 call->class->perf_probe,
530 call);
531 case TRACE_REG_PERF_UNREGISTER:
532 tracepoint_probe_unregister(call->tp,
533 call->class->perf_probe,
534 call);
535 return 0;
536 case TRACE_REG_PERF_OPEN:
537 case TRACE_REG_PERF_CLOSE:
538 case TRACE_REG_PERF_ADD:
539 case TRACE_REG_PERF_DEL:
540 return 0;
541 #endif
542 }
543 return 0;
544 }
545 EXPORT_SYMBOL_GPL(trace_event_reg);
546
547 void trace_event_enable_cmd_record(bool enable)
548 {
549 struct trace_event_file *file;
550 struct trace_array *tr;
551
552 lockdep_assert_held(&event_mutex);
553
554 do_for_each_event_file(tr, file) {
555
556 if (!(file->flags & EVENT_FILE_FL_ENABLED))
557 continue;
558
559 if (enable) {
560 tracing_start_cmdline_record();
561 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
562 } else {
563 tracing_stop_cmdline_record();
564 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
565 }
566 } while_for_each_event_file();
567 }
568
569 void trace_event_enable_tgid_record(bool enable)
570 {
571 struct trace_event_file *file;
572 struct trace_array *tr;
573
574 lockdep_assert_held(&event_mutex);
575
576 do_for_each_event_file(tr, file) {
577 if (!(file->flags & EVENT_FILE_FL_ENABLED))
578 continue;
579
580 if (enable) {
581 tracing_start_tgid_record();
582 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
583 } else {
584 tracing_stop_tgid_record();
585 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
586 &file->flags);
587 }
588 } while_for_each_event_file();
589 }
590
591 static int __ftrace_event_enable_disable(struct trace_event_file *file,
592 int enable, int soft_disable)
593 {
594 struct trace_event_call *call = file->event_call;
595 struct trace_array *tr = file->tr;
596 unsigned long file_flags = file->flags;
597 int ret = 0;
598 int disable;
599
600 switch (enable) {
601 case 0:
602 /*
603 * When soft_disable is set and enable is cleared, the sm_ref
604 * reference counter is decremented. If it reaches 0, we want
605 * to clear the SOFT_DISABLED flag but leave the event in the
606 * state that it was. That is, if the event was enabled and
607 * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
608 * is set we do not want the event to be enabled before we
609 * clear the bit.
610 *
611 * When soft_disable is not set but the SOFT_MODE flag is,
612 * we do nothing. Do not disable the tracepoint, otherwise
613 * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
614 */
615 if (soft_disable) {
616 if (atomic_dec_return(&file->sm_ref) > 0)
617 break;
618 disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
619 clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
620 } else
621 disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
622
623 if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
624 clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
625 if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
626 tracing_stop_cmdline_record();
627 clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
628 }
629
630 if (file->flags & EVENT_FILE_FL_RECORDED_TGID) {
631 tracing_stop_tgid_record();
632 clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
633 }
634
635 call->class->reg(call, TRACE_REG_UNREGISTER, file);
636 }
637 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
638 if (file->flags & EVENT_FILE_FL_SOFT_MODE)
639 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
640 else
641 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
642 break;
643 case 1:
644 /*
645 * When soft_disable is set and enable is set, we want to
646 * register the tracepoint for the event, but leave the event
647 * as is. That means, if the event was already enabled, we do
648 * nothing (but set SOFT_MODE). If the event is disabled, we
649 * set SOFT_DISABLED before enabling the event tracepoint, so
650 * it still seems to be disabled.
651 */
652 if (!soft_disable)
653 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
654 else {
655 if (atomic_inc_return(&file->sm_ref) > 1)
656 break;
657 set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
658 }
659
660 if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
661 bool cmd = false, tgid = false;
662
663 /* Keep the event disabled, when going to SOFT_MODE. */
664 if (soft_disable)
665 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
666
667 if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
668 cmd = true;
669 tracing_start_cmdline_record();
670 set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
671 }
672
673 if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
674 tgid = true;
675 tracing_start_tgid_record();
676 set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
677 }
678
679 ret = call->class->reg(call, TRACE_REG_REGISTER, file);
680 if (ret) {
681 if (cmd)
682 tracing_stop_cmdline_record();
683 if (tgid)
684 tracing_stop_tgid_record();
685 pr_info("event trace: Could not enable event "
686 "%s\n", trace_event_name(call));
687 break;
688 }
689 set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
690
691 /* WAS_ENABLED gets set but never cleared. */
692 set_bit(EVENT_FILE_FL_WAS_ENABLED_BIT, &file->flags);
693 }
694 break;
695 }
696
697 /* Enable or disable use of trace_buffered_event */
698 if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) !=
699 (file->flags & EVENT_FILE_FL_SOFT_DISABLED)) {
700 if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
701 trace_buffered_event_enable();
702 else
703 trace_buffered_event_disable();
704 }
705
706 return ret;
707 }
708
709 int trace_event_enable_disable(struct trace_event_file *file,
710 int enable, int soft_disable)
711 {
712 return __ftrace_event_enable_disable(file, enable, soft_disable);
713 }
714
715 static int ftrace_event_enable_disable(struct trace_event_file *file,
716 int enable)
717 {
718 return __ftrace_event_enable_disable(file, enable, 0);
719 }
720
721 static void ftrace_clear_events(struct trace_array *tr)
722 {
723 struct trace_event_file *file;
724
725 mutex_lock(&event_mutex);
726 list_for_each_entry(file, &tr->events, list) {
727 ftrace_event_enable_disable(file, 0);
728 }
729 mutex_unlock(&event_mutex);
730 }
731
732 static void
733 event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
734 {
735 struct trace_pid_list *pid_list;
736 struct trace_array *tr = data;
737
738 pid_list = rcu_dereference_raw(tr->filtered_pids);
739 trace_filter_add_remove_task(pid_list, NULL, task);
740
741 pid_list = rcu_dereference_raw(tr->filtered_no_pids);
742 trace_filter_add_remove_task(pid_list, NULL, task);
743 }
744
745 static void
746 event_filter_pid_sched_process_fork(void *data,
747 struct task_struct *self,
748 struct task_struct *task)
749 {
750 struct trace_pid_list *pid_list;
751 struct trace_array *tr = data;
752
753 pid_list = rcu_dereference_sched(tr->filtered_pids);
754 trace_filter_add_remove_task(pid_list, self, task);
755
756 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
757 trace_filter_add_remove_task(pid_list, self, task);
758 }
759
760 void trace_event_follow_fork(struct trace_array *tr, bool enable)
761 {
762 if (enable) {
763 register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
764 tr, INT_MIN);
765 register_trace_prio_sched_process_free(event_filter_pid_sched_process_exit,
766 tr, INT_MAX);
767 } else {
768 unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
769 tr);
770 unregister_trace_sched_process_free(event_filter_pid_sched_process_exit,
771 tr);
772 }
773 }
774
775 static void
776 event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
777 struct task_struct *prev,
778 struct task_struct *next,
779 unsigned int prev_state)
780 {
781 struct trace_array *tr = data;
782 struct trace_pid_list *no_pid_list;
783 struct trace_pid_list *pid_list;
784 bool ret;
785
786 pid_list = rcu_dereference_sched(tr->filtered_pids);
787 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
788
789 /*
790 * Sched switch is funny, as we only want to ignore it
791 * in the notrace case if both prev and next should be ignored.
792 */
793 ret = trace_ignore_this_task(NULL, no_pid_list, prev) &&
794 trace_ignore_this_task(NULL, no_pid_list, next);
795
796 this_cpu_write(tr->array_buffer.data->ignore_pid, ret ||
797 (trace_ignore_this_task(pid_list, NULL, prev) &&
798 trace_ignore_this_task(pid_list, NULL, next)));
799 }
800
801 static void
802 event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
803 struct task_struct *prev,
804 struct task_struct *next,
805 unsigned int prev_state)
806 {
807 struct trace_array *tr = data;
808 struct trace_pid_list *no_pid_list;
809 struct trace_pid_list *pid_list;
810
811 pid_list = rcu_dereference_sched(tr->filtered_pids);
812 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
813
814 this_cpu_write(tr->array_buffer.data->ignore_pid,
815 trace_ignore_this_task(pid_list, no_pid_list, next));
816 }
817
818 static void
819 event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
820 {
821 struct trace_array *tr = data;
822 struct trace_pid_list *no_pid_list;
823 struct trace_pid_list *pid_list;
824
825 /* Nothing to do if we are already tracing */
826 if (!this_cpu_read(tr->array_buffer.data->ignore_pid))
827 return;
828
829 pid_list = rcu_dereference_sched(tr->filtered_pids);
830 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
831
832 this_cpu_write(tr->array_buffer.data->ignore_pid,
833 trace_ignore_this_task(pid_list, no_pid_list, task));
834 }
835
836 static void
837 event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
838 {
839 struct trace_array *tr = data;
840 struct trace_pid_list *no_pid_list;
841 struct trace_pid_list *pid_list;
842
843 /* Nothing to do if we are not tracing */
844 if (this_cpu_read(tr->array_buffer.data->ignore_pid))
845 return;
846
847 pid_list = rcu_dereference_sched(tr->filtered_pids);
848 no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
849
850 /* Set tracing if current is enabled */
851 this_cpu_write(tr->array_buffer.data->ignore_pid,
852 trace_ignore_this_task(pid_list, no_pid_list, current));
853 }
854
855 static void unregister_pid_events(struct trace_array *tr)
856 {
857 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
858 unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
859
860 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
861 unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
862
863 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
864 unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
865
866 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
867 unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
868 }
869
870 static void __ftrace_clear_event_pids(struct trace_array *tr, int type)
871 {
872 struct trace_pid_list *pid_list;
873 struct trace_pid_list *no_pid_list;
874 struct trace_event_file *file;
875 int cpu;
876
877 pid_list = rcu_dereference_protected(tr->filtered_pids,
878 lockdep_is_held(&event_mutex));
879 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
880 lockdep_is_held(&event_mutex));
881
882 /* Make sure there's something to do */
883 if (!pid_type_enabled(type, pid_list, no_pid_list))
884 return;
885
886 if (!still_need_pid_events(type, pid_list, no_pid_list)) {
887 unregister_pid_events(tr);
888
889 list_for_each_entry(file, &tr->events, list) {
890 clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
891 }
892
893 for_each_possible_cpu(cpu)
894 per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false;
895 }
896
897 if (type & TRACE_PIDS)
898 rcu_assign_pointer(tr->filtered_pids, NULL);
899
900 if (type & TRACE_NO_PIDS)
901 rcu_assign_pointer(tr->filtered_no_pids, NULL);
902
903 /* Wait till all users are no longer using pid filtering */
904 tracepoint_synchronize_unregister();
905
906 if ((type & TRACE_PIDS) && pid_list)
907 trace_pid_list_free(pid_list);
908
909 if ((type & TRACE_NO_PIDS) && no_pid_list)
910 trace_pid_list_free(no_pid_list);
911 }
912
913 static void ftrace_clear_event_pids(struct trace_array *tr, int type)
914 {
915 mutex_lock(&event_mutex);
916 __ftrace_clear_event_pids(tr, type);
917 mutex_unlock(&event_mutex);
918 }
919
920 static void __put_system(struct event_subsystem *system)
921 {
922 struct event_filter *filter = system->filter;
923
924 WARN_ON_ONCE(system_refcount(system) == 0);
925 if (system_refcount_dec(system))
926 return;
927
928 list_del(&system->list);
929
930 if (filter) {
931 kfree(filter->filter_string);
932 kfree(filter);
933 }
934 kfree_const(system->name);
935 kfree(system);
936 }
937
938 static void __get_system(struct event_subsystem *system)
939 {
940 WARN_ON_ONCE(system_refcount(system) == 0);
941 system_refcount_inc(system);
942 }
943
944 static void __get_system_dir(struct trace_subsystem_dir *dir)
945 {
946 WARN_ON_ONCE(dir->ref_count == 0);
947 dir->ref_count++;
948 __get_system(dir->subsystem);
949 }
950
951 static void __put_system_dir(struct trace_subsystem_dir *dir)
952 {
953 WARN_ON_ONCE(dir->ref_count == 0);
954 /* If the subsystem is about to be freed, the dir must be too */
955 WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
956
957 __put_system(dir->subsystem);
958 if (!--dir->ref_count)
959 kfree(dir);
960 }
961
962 static void put_system(struct trace_subsystem_dir *dir)
963 {
964 mutex_lock(&event_mutex);
965 __put_system_dir(dir);
966 mutex_unlock(&event_mutex);
967 }
968
969 static void remove_subsystem(struct trace_subsystem_dir *dir)
970 {
971 if (!dir)
972 return;
973
974 if (!--dir->nr_events) {
975 tracefs_remove(dir->entry);
976 list_del(&dir->list);
977 __put_system_dir(dir);
978 }
979 }
980
981 static void remove_event_file_dir(struct trace_event_file *file)
982 {
983 struct dentry *dir = file->dir;
984 struct dentry *child;
985
986 if (dir) {
987 spin_lock(&dir->d_lock); /* probably unneeded */
988 list_for_each_entry(child, &dir->d_subdirs, d_child) {
989 if (d_really_is_positive(child)) /* probably unneeded */
990 d_inode(child)->i_private = NULL;
991 }
992 spin_unlock(&dir->d_lock);
993
994 tracefs_remove(dir);
995 }
996
997 list_del(&file->list);
998 remove_subsystem(file->system);
999 free_event_filter(file->filter);
1000 kmem_cache_free(file_cachep, file);
1001 }
1002
1003 /*
1004 * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
1005 */
1006 static int
1007 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
1008 const char *sub, const char *event, int set)
1009 {
1010 struct trace_event_file *file;
1011 struct trace_event_call *call;
1012 const char *name;
1013 int ret = -EINVAL;
1014 int eret = 0;
1015
1016 list_for_each_entry(file, &tr->events, list) {
1017
1018 call = file->event_call;
1019 name = trace_event_name(call);
1020
1021 if (!name || !call->class || !call->class->reg)
1022 continue;
1023
1024 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1025 continue;
1026
1027 if (match &&
1028 strcmp(match, name) != 0 &&
1029 strcmp(match, call->class->system) != 0)
1030 continue;
1031
1032 if (sub && strcmp(sub, call->class->system) != 0)
1033 continue;
1034
1035 if (event && strcmp(event, name) != 0)
1036 continue;
1037
1038 ret = ftrace_event_enable_disable(file, set);
1039
1040 /*
1041 * Save the first error and return that. Some events
1042 * may still have been enabled, but let the user
1043 * know that something went wrong.
1044 */
1045 if (ret && !eret)
1046 eret = ret;
1047
1048 ret = eret;
1049 }
1050
1051 return ret;
1052 }
1053
1054 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
1055 const char *sub, const char *event, int set)
1056 {
1057 int ret;
1058
1059 mutex_lock(&event_mutex);
1060 ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
1061 mutex_unlock(&event_mutex);
1062
1063 return ret;
1064 }
1065
1066 int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
1067 {
1068 char *event = NULL, *sub = NULL, *match;
1069 int ret;
1070
1071 if (!tr)
1072 return -ENOENT;
1073 /*
1074 * The buf format can be <subsystem>:<event-name>
1075 * *:<event-name> means any event by that name.
1076 * :<event-name> is the same.
1077 *
1078 * <subsystem>:* means all events in that subsystem
1079 * <subsystem>: means the same.
1080 *
1081 * <name> (no ':') means all events in a subsystem with
1082 * the name <name> or any event that matches <name>
1083 */
1084
1085 match = strsep(&buf, ":");
1086 if (buf) {
1087 sub = match;
1088 event = buf;
1089 match = NULL;
1090
1091 if (!strlen(sub) || strcmp(sub, "*") == 0)
1092 sub = NULL;
1093 if (!strlen(event) || strcmp(event, "*") == 0)
1094 event = NULL;
1095 }
1096
1097 ret = __ftrace_set_clr_event(tr, match, sub, event, set);
1098
1099 /* Put back the colon to allow this to be called again */
1100 if (buf)
1101 *(buf - 1) = ':';
1102
1103 return ret;
1104 }
1105
1106 /**
1107 * trace_set_clr_event - enable or disable an event
1108 * @system: system name to match (NULL for any system)
1109 * @event: event name to match (NULL for all events, within system)
1110 * @set: 1 to enable, 0 to disable
1111 *
1112 * This is a way for other parts of the kernel to enable or disable
1113 * event recording.
1114 *
1115 * Returns 0 on success, -EINVAL if the parameters do not match any
1116 * registered events.
1117 */
1118 int trace_set_clr_event(const char *system, const char *event, int set)
1119 {
1120 struct trace_array *tr = top_trace_array();
1121
1122 if (!tr)
1123 return -ENODEV;
1124
1125 return __ftrace_set_clr_event(tr, NULL, system, event, set);
1126 }
1127 EXPORT_SYMBOL_GPL(trace_set_clr_event);
1128
1129 /**
1130 * trace_array_set_clr_event - enable or disable an event for a trace array.
1131 * @tr: concerned trace array.
1132 * @system: system name to match (NULL for any system)
1133 * @event: event name to match (NULL for all events, within system)
1134 * @enable: true to enable, false to disable
1135 *
1136 * This is a way for other parts of the kernel to enable or disable
1137 * event recording.
1138 *
1139 * Returns 0 on success, -EINVAL if the parameters do not match any
1140 * registered events.
1141 */
1142 int trace_array_set_clr_event(struct trace_array *tr, const char *system,
1143 const char *event, bool enable)
1144 {
1145 int set;
1146
1147 if (!tr)
1148 return -ENOENT;
1149
1150 set = (enable == true) ? 1 : 0;
1151 return __ftrace_set_clr_event(tr, NULL, system, event, set);
1152 }
1153 EXPORT_SYMBOL_GPL(trace_array_set_clr_event);
1154
1155 /* 128 should be much more than enough */
1156 #define EVENT_BUF_SIZE 127
1157
1158 static ssize_t
1159 ftrace_event_write(struct file *file, const char __user *ubuf,
1160 size_t cnt, loff_t *ppos)
1161 {
1162 struct trace_parser parser;
1163 struct seq_file *m = file->private_data;
1164 struct trace_array *tr = m->private;
1165 ssize_t read, ret;
1166
1167 if (!cnt)
1168 return 0;
1169
1170 ret = tracing_update_buffers();
1171 if (ret < 0)
1172 return ret;
1173
1174 if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
1175 return -ENOMEM;
1176
1177 read = trace_get_user(&parser, ubuf, cnt, ppos);
1178
1179 if (read >= 0 && trace_parser_loaded((&parser))) {
1180 int set = 1;
1181
1182 if (*parser.buffer == '!')
1183 set = 0;
1184
1185 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
1186 if (ret)
1187 goto out_put;
1188 }
1189
1190 ret = read;
1191
1192 out_put:
1193 trace_parser_put(&parser);
1194
1195 return ret;
1196 }
1197
1198 static void *
1199 t_next(struct seq_file *m, void *v, loff_t *pos)
1200 {
1201 struct trace_event_file *file = v;
1202 struct trace_event_call *call;
1203 struct trace_array *tr = m->private;
1204
1205 (*pos)++;
1206
1207 list_for_each_entry_continue(file, &tr->events, list) {
1208 call = file->event_call;
1209 /*
1210 * The ftrace subsystem is for showing formats only.
1211 * They can not be enabled or disabled via the event files.
1212 */
1213 if (call->class && call->class->reg &&
1214 !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1215 return file;
1216 }
1217
1218 return NULL;
1219 }
1220
1221 static void *t_start(struct seq_file *m, loff_t *pos)
1222 {
1223 struct trace_event_file *file;
1224 struct trace_array *tr = m->private;
1225 loff_t l;
1226
1227 mutex_lock(&event_mutex);
1228
1229 file = list_entry(&tr->events, struct trace_event_file, list);
1230 for (l = 0; l <= *pos; ) {
1231 file = t_next(m, file, &l);
1232 if (!file)
1233 break;
1234 }
1235 return file;
1236 }
1237
1238 static void *
1239 s_next(struct seq_file *m, void *v, loff_t *pos)
1240 {
1241 struct trace_event_file *file = v;
1242 struct trace_array *tr = m->private;
1243
1244 (*pos)++;
1245
1246 list_for_each_entry_continue(file, &tr->events, list) {
1247 if (file->flags & EVENT_FILE_FL_ENABLED)
1248 return file;
1249 }
1250
1251 return NULL;
1252 }
1253
1254 static void *s_start(struct seq_file *m, loff_t *pos)
1255 {
1256 struct trace_event_file *file;
1257 struct trace_array *tr = m->private;
1258 loff_t l;
1259
1260 mutex_lock(&event_mutex);
1261
1262 file = list_entry(&tr->events, struct trace_event_file, list);
1263 for (l = 0; l <= *pos; ) {
1264 file = s_next(m, file, &l);
1265 if (!file)
1266 break;
1267 }
1268 return file;
1269 }
1270
1271 static int t_show(struct seq_file *m, void *v)
1272 {
1273 struct trace_event_file *file = v;
1274 struct trace_event_call *call = file->event_call;
1275
1276 if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1277 seq_printf(m, "%s:", call->class->system);
1278 seq_printf(m, "%s\n", trace_event_name(call));
1279
1280 return 0;
1281 }
1282
1283 static void t_stop(struct seq_file *m, void *p)
1284 {
1285 mutex_unlock(&event_mutex);
1286 }
1287
1288 static void *
1289 __next(struct seq_file *m, void *v, loff_t *pos, int type)
1290 {
1291 struct trace_array *tr = m->private;
1292 struct trace_pid_list *pid_list;
1293
1294 if (type == TRACE_PIDS)
1295 pid_list = rcu_dereference_sched(tr->filtered_pids);
1296 else
1297 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1298
1299 return trace_pid_next(pid_list, v, pos);
1300 }
1301
1302 static void *
1303 p_next(struct seq_file *m, void *v, loff_t *pos)
1304 {
1305 return __next(m, v, pos, TRACE_PIDS);
1306 }
1307
1308 static void *
1309 np_next(struct seq_file *m, void *v, loff_t *pos)
1310 {
1311 return __next(m, v, pos, TRACE_NO_PIDS);
1312 }
1313
1314 static void *__start(struct seq_file *m, loff_t *pos, int type)
1315 __acquires(RCU)
1316 {
1317 struct trace_pid_list *pid_list;
1318 struct trace_array *tr = m->private;
1319
1320 /*
1321 * Grab the mutex, to keep calls to p_next() having the same
1322 * tr->filtered_pids as p_start() has.
1323 * If we just passed the tr->filtered_pids around, then RCU would
1324 * have been enough, but doing that makes things more complex.
1325 */
1326 mutex_lock(&event_mutex);
1327 rcu_read_lock_sched();
1328
1329 if (type == TRACE_PIDS)
1330 pid_list = rcu_dereference_sched(tr->filtered_pids);
1331 else
1332 pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1333
1334 if (!pid_list)
1335 return NULL;
1336
1337 return trace_pid_start(pid_list, pos);
1338 }
1339
1340 static void *p_start(struct seq_file *m, loff_t *pos)
1341 __acquires(RCU)
1342 {
1343 return __start(m, pos, TRACE_PIDS);
1344 }
1345
1346 static void *np_start(struct seq_file *m, loff_t *pos)
1347 __acquires(RCU)
1348 {
1349 return __start(m, pos, TRACE_NO_PIDS);
1350 }
1351
1352 static void p_stop(struct seq_file *m, void *p)
1353 __releases(RCU)
1354 {
1355 rcu_read_unlock_sched();
1356 mutex_unlock(&event_mutex);
1357 }
1358
1359 static ssize_t
1360 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1361 loff_t *ppos)
1362 {
1363 struct trace_event_file *file;
1364 unsigned long flags;
1365 char buf[4] = "0";
1366
1367 mutex_lock(&event_mutex);
1368 file = event_file_data(filp);
1369 if (likely(file))
1370 flags = file->flags;
1371 mutex_unlock(&event_mutex);
1372
1373 if (!file)
1374 return -ENODEV;
1375
1376 if (flags & EVENT_FILE_FL_ENABLED &&
1377 !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1378 strcpy(buf, "1");
1379
1380 if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1381 flags & EVENT_FILE_FL_SOFT_MODE)
1382 strcat(buf, "*");
1383
1384 strcat(buf, "\n");
1385
1386 return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1387 }
1388
1389 static ssize_t
1390 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1391 loff_t *ppos)
1392 {
1393 struct trace_event_file *file;
1394 unsigned long val;
1395 int ret;
1396
1397 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1398 if (ret)
1399 return ret;
1400
1401 ret = tracing_update_buffers();
1402 if (ret < 0)
1403 return ret;
1404
1405 switch (val) {
1406 case 0:
1407 case 1:
1408 ret = -ENODEV;
1409 mutex_lock(&event_mutex);
1410 file = event_file_data(filp);
1411 if (likely(file))
1412 ret = ftrace_event_enable_disable(file, val);
1413 mutex_unlock(&event_mutex);
1414 break;
1415
1416 default:
1417 return -EINVAL;
1418 }
1419
1420 *ppos += cnt;
1421
1422 return ret ? ret : cnt;
1423 }
1424
1425 static ssize_t
1426 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1427 loff_t *ppos)
1428 {
1429 const char set_to_char[4] = { '?', '0', '1', 'X' };
1430 struct trace_subsystem_dir *dir = filp->private_data;
1431 struct event_subsystem *system = dir->subsystem;
1432 struct trace_event_call *call;
1433 struct trace_event_file *file;
1434 struct trace_array *tr = dir->tr;
1435 char buf[2];
1436 int set = 0;
1437 int ret;
1438
1439 mutex_lock(&event_mutex);
1440 list_for_each_entry(file, &tr->events, list) {
1441 call = file->event_call;
1442 if ((call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) ||
1443 !trace_event_name(call) || !call->class || !call->class->reg)
1444 continue;
1445
1446 if (system && strcmp(call->class->system, system->name) != 0)
1447 continue;
1448
1449 /*
1450 * We need to find out if all the events are set
1451 * or if all events or cleared, or if we have
1452 * a mixture.
1453 */
1454 set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1455
1456 /*
1457 * If we have a mixture, no need to look further.
1458 */
1459 if (set == 3)
1460 break;
1461 }
1462 mutex_unlock(&event_mutex);
1463
1464 buf[0] = set_to_char[set];
1465 buf[1] = '\n';
1466
1467 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1468
1469 return ret;
1470 }
1471
1472 static ssize_t
1473 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1474 loff_t *ppos)
1475 {
1476 struct trace_subsystem_dir *dir = filp->private_data;
1477 struct event_subsystem *system = dir->subsystem;
1478 const char *name = NULL;
1479 unsigned long val;
1480 ssize_t ret;
1481
1482 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1483 if (ret)
1484 return ret;
1485
1486 ret = tracing_update_buffers();
1487 if (ret < 0)
1488 return ret;
1489
1490 if (val != 0 && val != 1)
1491 return -EINVAL;
1492
1493 /*
1494 * Opening of "enable" adds a ref count to system,
1495 * so the name is safe to use.
1496 */
1497 if (system)
1498 name = system->name;
1499
1500 ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1501 if (ret)
1502 goto out;
1503
1504 ret = cnt;
1505
1506 out:
1507 *ppos += cnt;
1508
1509 return ret;
1510 }
1511
1512 enum {
1513 FORMAT_HEADER = 1,
1514 FORMAT_FIELD_SEPERATOR = 2,
1515 FORMAT_PRINTFMT = 3,
1516 };
1517
1518 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1519 {
1520 struct trace_event_call *call = event_file_data(m->private);
1521 struct list_head *common_head = &ftrace_common_fields;
1522 struct list_head *head = trace_get_fields(call);
1523 struct list_head *node = v;
1524
1525 (*pos)++;
1526
1527 switch ((unsigned long)v) {
1528 case FORMAT_HEADER:
1529 node = common_head;
1530 break;
1531
1532 case FORMAT_FIELD_SEPERATOR:
1533 node = head;
1534 break;
1535
1536 case FORMAT_PRINTFMT:
1537 /* all done */
1538 return NULL;
1539 }
1540
1541 node = node->prev;
1542 if (node == common_head)
1543 return (void *)FORMAT_FIELD_SEPERATOR;
1544 else if (node == head)
1545 return (void *)FORMAT_PRINTFMT;
1546 else
1547 return node;
1548 }
1549
1550 static int f_show(struct seq_file *m, void *v)
1551 {
1552 struct trace_event_call *call = event_file_data(m->private);
1553 struct ftrace_event_field *field;
1554 const char *array_descriptor;
1555
1556 switch ((unsigned long)v) {
1557 case FORMAT_HEADER:
1558 seq_printf(m, "name: %s\n", trace_event_name(call));
1559 seq_printf(m, "ID: %d\n", call->event.type);
1560 seq_puts(m, "format:\n");
1561 return 0;
1562
1563 case FORMAT_FIELD_SEPERATOR:
1564 seq_putc(m, '\n');
1565 return 0;
1566
1567 case FORMAT_PRINTFMT:
1568 seq_printf(m, "\nprint fmt: %s\n",
1569 call->print_fmt);
1570 return 0;
1571 }
1572
1573 field = list_entry(v, struct ftrace_event_field, link);
1574 /*
1575 * Smartly shows the array type(except dynamic array).
1576 * Normal:
1577 * field:TYPE VAR
1578 * If TYPE := TYPE[LEN], it is shown:
1579 * field:TYPE VAR[LEN]
1580 */
1581 array_descriptor = strchr(field->type, '[');
1582
1583 if (str_has_prefix(field->type, "__data_loc"))
1584 array_descriptor = NULL;
1585
1586 if (!array_descriptor)
1587 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1588 field->type, field->name, field->offset,
1589 field->size, !!field->is_signed);
1590 else
1591 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1592 (int)(array_descriptor - field->type),
1593 field->type, field->name,
1594 array_descriptor, field->offset,
1595 field->size, !!field->is_signed);
1596
1597 return 0;
1598 }
1599
1600 static void *f_start(struct seq_file *m, loff_t *pos)
1601 {
1602 void *p = (void *)FORMAT_HEADER;
1603 loff_t l = 0;
1604
1605 /* ->stop() is called even if ->start() fails */
1606 mutex_lock(&event_mutex);
1607 if (!event_file_data(m->private))
1608 return ERR_PTR(-ENODEV);
1609
1610 while (l < *pos && p)
1611 p = f_next(m, p, &l);
1612
1613 return p;
1614 }
1615
1616 static void f_stop(struct seq_file *m, void *p)
1617 {
1618 mutex_unlock(&event_mutex);
1619 }
1620
1621 static const struct seq_operations trace_format_seq_ops = {
1622 .start = f_start,
1623 .next = f_next,
1624 .stop = f_stop,
1625 .show = f_show,
1626 };
1627
1628 static int trace_format_open(struct inode *inode, struct file *file)
1629 {
1630 struct seq_file *m;
1631 int ret;
1632
1633 /* Do we want to hide event format files on tracefs lockdown? */
1634
1635 ret = seq_open(file, &trace_format_seq_ops);
1636 if (ret < 0)
1637 return ret;
1638
1639 m = file->private_data;
1640 m->private = file;
1641
1642 return 0;
1643 }
1644
1645 static ssize_t
1646 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1647 {
1648 int id = (long)event_file_data(filp);
1649 char buf[32];
1650 int len;
1651
1652 if (unlikely(!id))
1653 return -ENODEV;
1654
1655 len = sprintf(buf, "%d\n", id);
1656
1657 return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1658 }
1659
1660 static ssize_t
1661 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1662 loff_t *ppos)
1663 {
1664 struct trace_event_file *file;
1665 struct trace_seq *s;
1666 int r = -ENODEV;
1667
1668 if (*ppos)
1669 return 0;
1670
1671 s = kmalloc(sizeof(*s), GFP_KERNEL);
1672
1673 if (!s)
1674 return -ENOMEM;
1675
1676 trace_seq_init(s);
1677
1678 mutex_lock(&event_mutex);
1679 file = event_file_data(filp);
1680 if (file)
1681 print_event_filter(file, s);
1682 mutex_unlock(&event_mutex);
1683
1684 if (file)
1685 r = simple_read_from_buffer(ubuf, cnt, ppos,
1686 s->buffer, trace_seq_used(s));
1687
1688 kfree(s);
1689
1690 return r;
1691 }
1692
1693 static ssize_t
1694 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1695 loff_t *ppos)
1696 {
1697 struct trace_event_file *file;
1698 char *buf;
1699 int err = -ENODEV;
1700
1701 if (cnt >= PAGE_SIZE)
1702 return -EINVAL;
1703
1704 buf = memdup_user_nul(ubuf, cnt);
1705 if (IS_ERR(buf))
1706 return PTR_ERR(buf);
1707
1708 mutex_lock(&event_mutex);
1709 file = event_file_data(filp);
1710 if (file)
1711 err = apply_event_filter(file, buf);
1712 mutex_unlock(&event_mutex);
1713
1714 kfree(buf);
1715 if (err < 0)
1716 return err;
1717
1718 *ppos += cnt;
1719
1720 return cnt;
1721 }
1722
1723 static LIST_HEAD(event_subsystems);
1724
1725 static int subsystem_open(struct inode *inode, struct file *filp)
1726 {
1727 struct trace_subsystem_dir *dir = NULL, *iter_dir;
1728 struct trace_array *tr = NULL, *iter_tr;
1729 struct event_subsystem *system = NULL;
1730 int ret;
1731
1732 if (tracing_is_disabled())
1733 return -ENODEV;
1734
1735 /* Make sure the system still exists */
1736 mutex_lock(&event_mutex);
1737 mutex_lock(&trace_types_lock);
1738 list_for_each_entry(iter_tr, &ftrace_trace_arrays, list) {
1739 list_for_each_entry(iter_dir, &iter_tr->systems, list) {
1740 if (iter_dir == inode->i_private) {
1741 /* Don't open systems with no events */
1742 tr = iter_tr;
1743 dir = iter_dir;
1744 if (dir->nr_events) {
1745 __get_system_dir(dir);
1746 system = dir->subsystem;
1747 }
1748 goto exit_loop;
1749 }
1750 }
1751 }
1752 exit_loop:
1753 mutex_unlock(&trace_types_lock);
1754 mutex_unlock(&event_mutex);
1755
1756 if (!system)
1757 return -ENODEV;
1758
1759 /* Still need to increment the ref count of the system */
1760 if (trace_array_get(tr) < 0) {
1761 put_system(dir);
1762 return -ENODEV;
1763 }
1764
1765 ret = tracing_open_generic(inode, filp);
1766 if (ret < 0) {
1767 trace_array_put(tr);
1768 put_system(dir);
1769 }
1770
1771 return ret;
1772 }
1773
1774 static int system_tr_open(struct inode *inode, struct file *filp)
1775 {
1776 struct trace_subsystem_dir *dir;
1777 struct trace_array *tr = inode->i_private;
1778 int ret;
1779
1780 /* Make a temporary dir that has no system but points to tr */
1781 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1782 if (!dir)
1783 return -ENOMEM;
1784
1785 ret = tracing_open_generic_tr(inode, filp);
1786 if (ret < 0) {
1787 kfree(dir);
1788 return ret;
1789 }
1790 dir->tr = tr;
1791 filp->private_data = dir;
1792
1793 return 0;
1794 }
1795
1796 static int subsystem_release(struct inode *inode, struct file *file)
1797 {
1798 struct trace_subsystem_dir *dir = file->private_data;
1799
1800 trace_array_put(dir->tr);
1801
1802 /*
1803 * If dir->subsystem is NULL, then this is a temporary
1804 * descriptor that was made for a trace_array to enable
1805 * all subsystems.
1806 */
1807 if (dir->subsystem)
1808 put_system(dir);
1809 else
1810 kfree(dir);
1811
1812 return 0;
1813 }
1814
1815 static ssize_t
1816 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1817 loff_t *ppos)
1818 {
1819 struct trace_subsystem_dir *dir = filp->private_data;
1820 struct event_subsystem *system = dir->subsystem;
1821 struct trace_seq *s;
1822 int r;
1823
1824 if (*ppos)
1825 return 0;
1826
1827 s = kmalloc(sizeof(*s), GFP_KERNEL);
1828 if (!s)
1829 return -ENOMEM;
1830
1831 trace_seq_init(s);
1832
1833 print_subsystem_event_filter(system, s);
1834 r = simple_read_from_buffer(ubuf, cnt, ppos,
1835 s->buffer, trace_seq_used(s));
1836
1837 kfree(s);
1838
1839 return r;
1840 }
1841
1842 static ssize_t
1843 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1844 loff_t *ppos)
1845 {
1846 struct trace_subsystem_dir *dir = filp->private_data;
1847 char *buf;
1848 int err;
1849
1850 if (cnt >= PAGE_SIZE)
1851 return -EINVAL;
1852
1853 buf = memdup_user_nul(ubuf, cnt);
1854 if (IS_ERR(buf))
1855 return PTR_ERR(buf);
1856
1857 err = apply_subsystem_event_filter(dir, buf);
1858 kfree(buf);
1859 if (err < 0)
1860 return err;
1861
1862 *ppos += cnt;
1863
1864 return cnt;
1865 }
1866
1867 static ssize_t
1868 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1869 {
1870 int (*func)(struct trace_seq *s) = filp->private_data;
1871 struct trace_seq *s;
1872 int r;
1873
1874 if (*ppos)
1875 return 0;
1876
1877 s = kmalloc(sizeof(*s), GFP_KERNEL);
1878 if (!s)
1879 return -ENOMEM;
1880
1881 trace_seq_init(s);
1882
1883 func(s);
1884 r = simple_read_from_buffer(ubuf, cnt, ppos,
1885 s->buffer, trace_seq_used(s));
1886
1887 kfree(s);
1888
1889 return r;
1890 }
1891
1892 static void ignore_task_cpu(void *data)
1893 {
1894 struct trace_array *tr = data;
1895 struct trace_pid_list *pid_list;
1896 struct trace_pid_list *no_pid_list;
1897
1898 /*
1899 * This function is called by on_each_cpu() while the
1900 * event_mutex is held.
1901 */
1902 pid_list = rcu_dereference_protected(tr->filtered_pids,
1903 mutex_is_locked(&event_mutex));
1904 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
1905 mutex_is_locked(&event_mutex));
1906
1907 this_cpu_write(tr->array_buffer.data->ignore_pid,
1908 trace_ignore_this_task(pid_list, no_pid_list, current));
1909 }
1910
1911 static void register_pid_events(struct trace_array *tr)
1912 {
1913 /*
1914 * Register a probe that is called before all other probes
1915 * to set ignore_pid if next or prev do not match.
1916 * Register a probe this is called after all other probes
1917 * to only keep ignore_pid set if next pid matches.
1918 */
1919 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1920 tr, INT_MAX);
1921 register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1922 tr, 0);
1923
1924 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1925 tr, INT_MAX);
1926 register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1927 tr, 0);
1928
1929 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1930 tr, INT_MAX);
1931 register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1932 tr, 0);
1933
1934 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1935 tr, INT_MAX);
1936 register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1937 tr, 0);
1938 }
1939
1940 static ssize_t
1941 event_pid_write(struct file *filp, const char __user *ubuf,
1942 size_t cnt, loff_t *ppos, int type)
1943 {
1944 struct seq_file *m = filp->private_data;
1945 struct trace_array *tr = m->private;
1946 struct trace_pid_list *filtered_pids = NULL;
1947 struct trace_pid_list *other_pids = NULL;
1948 struct trace_pid_list *pid_list;
1949 struct trace_event_file *file;
1950 ssize_t ret;
1951
1952 if (!cnt)
1953 return 0;
1954
1955 ret = tracing_update_buffers();
1956 if (ret < 0)
1957 return ret;
1958
1959 mutex_lock(&event_mutex);
1960
1961 if (type == TRACE_PIDS) {
1962 filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1963 lockdep_is_held(&event_mutex));
1964 other_pids = rcu_dereference_protected(tr->filtered_no_pids,
1965 lockdep_is_held(&event_mutex));
1966 } else {
1967 filtered_pids = rcu_dereference_protected(tr->filtered_no_pids,
1968 lockdep_is_held(&event_mutex));
1969 other_pids = rcu_dereference_protected(tr->filtered_pids,
1970 lockdep_is_held(&event_mutex));
1971 }
1972
1973 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
1974 if (ret < 0)
1975 goto out;
1976
1977 if (type == TRACE_PIDS)
1978 rcu_assign_pointer(tr->filtered_pids, pid_list);
1979 else
1980 rcu_assign_pointer(tr->filtered_no_pids, pid_list);
1981
1982 list_for_each_entry(file, &tr->events, list) {
1983 set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1984 }
1985
1986 if (filtered_pids) {
1987 tracepoint_synchronize_unregister();
1988 trace_pid_list_free(filtered_pids);
1989 } else if (pid_list && !other_pids) {
1990 register_pid_events(tr);
1991 }
1992
1993 /*
1994 * Ignoring of pids is done at task switch. But we have to
1995 * check for those tasks that are currently running.
1996 * Always do this in case a pid was appended or removed.
1997 */
1998 on_each_cpu(ignore_task_cpu, tr, 1);
1999
2000 out:
2001 mutex_unlock(&event_mutex);
2002
2003 if (ret > 0)
2004 *ppos += ret;
2005
2006 return ret;
2007 }
2008
2009 static ssize_t
2010 ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
2011 size_t cnt, loff_t *ppos)
2012 {
2013 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
2014 }
2015
2016 static ssize_t
2017 ftrace_event_npid_write(struct file *filp, const char __user *ubuf,
2018 size_t cnt, loff_t *ppos)
2019 {
2020 return event_pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
2021 }
2022
2023 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
2024 static int ftrace_event_set_open(struct inode *inode, struct file *file);
2025 static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
2026 static int ftrace_event_set_npid_open(struct inode *inode, struct file *file);
2027 static int ftrace_event_release(struct inode *inode, struct file *file);
2028
2029 static const struct seq_operations show_event_seq_ops = {
2030 .start = t_start,
2031 .next = t_next,
2032 .show = t_show,
2033 .stop = t_stop,
2034 };
2035
2036 static const struct seq_operations show_set_event_seq_ops = {
2037 .start = s_start,
2038 .next = s_next,
2039 .show = t_show,
2040 .stop = t_stop,
2041 };
2042
2043 static const struct seq_operations show_set_pid_seq_ops = {
2044 .start = p_start,
2045 .next = p_next,
2046 .show = trace_pid_show,
2047 .stop = p_stop,
2048 };
2049
2050 static const struct seq_operations show_set_no_pid_seq_ops = {
2051 .start = np_start,
2052 .next = np_next,
2053 .show = trace_pid_show,
2054 .stop = p_stop,
2055 };
2056
2057 static const struct file_operations ftrace_avail_fops = {
2058 .open = ftrace_event_avail_open,
2059 .read = seq_read,
2060 .llseek = seq_lseek,
2061 .release = seq_release,
2062 };
2063
2064 static const struct file_operations ftrace_set_event_fops = {
2065 .open = ftrace_event_set_open,
2066 .read = seq_read,
2067 .write = ftrace_event_write,
2068 .llseek = seq_lseek,
2069 .release = ftrace_event_release,
2070 };
2071
2072 static const struct file_operations ftrace_set_event_pid_fops = {
2073 .open = ftrace_event_set_pid_open,
2074 .read = seq_read,
2075 .write = ftrace_event_pid_write,
2076 .llseek = seq_lseek,
2077 .release = ftrace_event_release,
2078 };
2079
2080 static const struct file_operations ftrace_set_event_notrace_pid_fops = {
2081 .open = ftrace_event_set_npid_open,
2082 .read = seq_read,
2083 .write = ftrace_event_npid_write,
2084 .llseek = seq_lseek,
2085 .release = ftrace_event_release,
2086 };
2087
2088 static const struct file_operations ftrace_enable_fops = {
2089 .open = tracing_open_generic,
2090 .read = event_enable_read,
2091 .write = event_enable_write,
2092 .llseek = default_llseek,
2093 };
2094
2095 static const struct file_operations ftrace_event_format_fops = {
2096 .open = trace_format_open,
2097 .read = seq_read,
2098 .llseek = seq_lseek,
2099 .release = seq_release,
2100 };
2101
2102 static const struct file_operations ftrace_event_id_fops = {
2103 .read = event_id_read,
2104 .llseek = default_llseek,
2105 };
2106
2107 static const struct file_operations ftrace_event_filter_fops = {
2108 .open = tracing_open_generic,
2109 .read = event_filter_read,
2110 .write = event_filter_write,
2111 .llseek = default_llseek,
2112 };
2113
2114 static const struct file_operations ftrace_subsystem_filter_fops = {
2115 .open = subsystem_open,
2116 .read = subsystem_filter_read,
2117 .write = subsystem_filter_write,
2118 .llseek = default_llseek,
2119 .release = subsystem_release,
2120 };
2121
2122 static const struct file_operations ftrace_system_enable_fops = {
2123 .open = subsystem_open,
2124 .read = system_enable_read,
2125 .write = system_enable_write,
2126 .llseek = default_llseek,
2127 .release = subsystem_release,
2128 };
2129
2130 static const struct file_operations ftrace_tr_enable_fops = {
2131 .open = system_tr_open,
2132 .read = system_enable_read,
2133 .write = system_enable_write,
2134 .llseek = default_llseek,
2135 .release = subsystem_release,
2136 };
2137
2138 static const struct file_operations ftrace_show_header_fops = {
2139 .open = tracing_open_generic,
2140 .read = show_header,
2141 .llseek = default_llseek,
2142 };
2143
2144 static int
2145 ftrace_event_open(struct inode *inode, struct file *file,
2146 const struct seq_operations *seq_ops)
2147 {
2148 struct seq_file *m;
2149 int ret;
2150
2151 ret = security_locked_down(LOCKDOWN_TRACEFS);
2152 if (ret)
2153 return ret;
2154
2155 ret = seq_open(file, seq_ops);
2156 if (ret < 0)
2157 return ret;
2158 m = file->private_data;
2159 /* copy tr over to seq ops */
2160 m->private = inode->i_private;
2161
2162 return ret;
2163 }
2164
2165 static int ftrace_event_release(struct inode *inode, struct file *file)
2166 {
2167 struct trace_array *tr = inode->i_private;
2168
2169 trace_array_put(tr);
2170
2171 return seq_release(inode, file);
2172 }
2173
2174 static int
2175 ftrace_event_avail_open(struct inode *inode, struct file *file)
2176 {
2177 const struct seq_operations *seq_ops = &show_event_seq_ops;
2178
2179 /* Checks for tracefs lockdown */
2180 return ftrace_event_open(inode, file, seq_ops);
2181 }
2182
2183 static int
2184 ftrace_event_set_open(struct inode *inode, struct file *file)
2185 {
2186 const struct seq_operations *seq_ops = &show_set_event_seq_ops;
2187 struct trace_array *tr = inode->i_private;
2188 int ret;
2189
2190 ret = tracing_check_open_get_tr(tr);
2191 if (ret)
2192 return ret;
2193
2194 if ((file->f_mode & FMODE_WRITE) &&
2195 (file->f_flags & O_TRUNC))
2196 ftrace_clear_events(tr);
2197
2198 ret = ftrace_event_open(inode, file, seq_ops);
2199 if (ret < 0)
2200 trace_array_put(tr);
2201 return ret;
2202 }
2203
2204 static int
2205 ftrace_event_set_pid_open(struct inode *inode, struct file *file)
2206 {
2207 const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
2208 struct trace_array *tr = inode->i_private;
2209 int ret;
2210
2211 ret = tracing_check_open_get_tr(tr);
2212 if (ret)
2213 return ret;
2214
2215 if ((file->f_mode & FMODE_WRITE) &&
2216 (file->f_flags & O_TRUNC))
2217 ftrace_clear_event_pids(tr, TRACE_PIDS);
2218
2219 ret = ftrace_event_open(inode, file, seq_ops);
2220 if (ret < 0)
2221 trace_array_put(tr);
2222 return ret;
2223 }
2224
2225 static int
2226 ftrace_event_set_npid_open(struct inode *inode, struct file *file)
2227 {
2228 const struct seq_operations *seq_ops = &show_set_no_pid_seq_ops;
2229 struct trace_array *tr = inode->i_private;
2230 int ret;
2231
2232 ret = tracing_check_open_get_tr(tr);
2233 if (ret)
2234 return ret;
2235
2236 if ((file->f_mode & FMODE_WRITE) &&
2237 (file->f_flags & O_TRUNC))
2238 ftrace_clear_event_pids(tr, TRACE_NO_PIDS);
2239
2240 ret = ftrace_event_open(inode, file, seq_ops);
2241 if (ret < 0)
2242 trace_array_put(tr);
2243 return ret;
2244 }
2245
2246 static struct event_subsystem *
2247 create_new_subsystem(const char *name)
2248 {
2249 struct event_subsystem *system;
2250
2251 /* need to create new entry */
2252 system = kmalloc(sizeof(*system), GFP_KERNEL);
2253 if (!system)
2254 return NULL;
2255
2256 system->ref_count = 1;
2257
2258 /* Only allocate if dynamic (kprobes and modules) */
2259 system->name = kstrdup_const(name, GFP_KERNEL);
2260 if (!system->name)
2261 goto out_free;
2262
2263 system->filter = NULL;
2264
2265 system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
2266 if (!system->filter)
2267 goto out_free;
2268
2269 list_add(&system->list, &event_subsystems);
2270
2271 return system;
2272
2273 out_free:
2274 kfree_const(system->name);
2275 kfree(system);
2276 return NULL;
2277 }
2278
2279 static struct dentry *
2280 event_subsystem_dir(struct trace_array *tr, const char *name,
2281 struct trace_event_file *file, struct dentry *parent)
2282 {
2283 struct event_subsystem *system, *iter;
2284 struct trace_subsystem_dir *dir;
2285 struct dentry *entry;
2286
2287 /* First see if we did not already create this dir */
2288 list_for_each_entry(dir, &tr->systems, list) {
2289 system = dir->subsystem;
2290 if (strcmp(system->name, name) == 0) {
2291 dir->nr_events++;
2292 file->system = dir;
2293 return dir->entry;
2294 }
2295 }
2296
2297 /* Now see if the system itself exists. */
2298 system = NULL;
2299 list_for_each_entry(iter, &event_subsystems, list) {
2300 if (strcmp(iter->name, name) == 0) {
2301 system = iter;
2302 break;
2303 }
2304 }
2305
2306 dir = kmalloc(sizeof(*dir), GFP_KERNEL);
2307 if (!dir)
2308 goto out_fail;
2309
2310 if (!system) {
2311 system = create_new_subsystem(name);
2312 if (!system)
2313 goto out_free;
2314 } else
2315 __get_system(system);
2316
2317 dir->entry = tracefs_create_dir(name, parent);
2318 if (!dir->entry) {
2319 pr_warn("Failed to create system directory %s\n", name);
2320 __put_system(system);
2321 goto out_free;
2322 }
2323
2324 dir->tr = tr;
2325 dir->ref_count = 1;
2326 dir->nr_events = 1;
2327 dir->subsystem = system;
2328 file->system = dir;
2329
2330 /* the ftrace system is special, do not create enable or filter files */
2331 if (strcmp(name, "ftrace") != 0) {
2332
2333 entry = tracefs_create_file("filter", TRACE_MODE_WRITE,
2334 dir->entry, dir,
2335 &ftrace_subsystem_filter_fops);
2336 if (!entry) {
2337 kfree(system->filter);
2338 system->filter = NULL;
2339 pr_warn("Could not create tracefs '%s/filter' entry\n", name);
2340 }
2341
2342 trace_create_file("enable", TRACE_MODE_WRITE, dir->entry, dir,
2343 &ftrace_system_enable_fops);
2344 }
2345
2346 list_add(&dir->list, &tr->systems);
2347
2348 return dir->entry;
2349
2350 out_free:
2351 kfree(dir);
2352 out_fail:
2353 /* Only print this message if failed on memory allocation */
2354 if (!dir || !system)
2355 pr_warn("No memory to create event subsystem %s\n", name);
2356 return NULL;
2357 }
2358
2359 static int
2360 event_define_fields(struct trace_event_call *call)
2361 {
2362 struct list_head *head;
2363 int ret = 0;
2364
2365 /*
2366 * Other events may have the same class. Only update
2367 * the fields if they are not already defined.
2368 */
2369 head = trace_get_fields(call);
2370 if (list_empty(head)) {
2371 struct trace_event_fields *field = call->class->fields_array;
2372 unsigned int offset = sizeof(struct trace_entry);
2373
2374 for (; field->type; field++) {
2375 if (field->type == TRACE_FUNCTION_TYPE) {
2376 field->define_fields(call);
2377 break;
2378 }
2379
2380 offset = ALIGN(offset, field->align);
2381 ret = trace_define_field(call, field->type, field->name,
2382 offset, field->size,
2383 field->is_signed, field->filter_type);
2384 if (WARN_ON_ONCE(ret)) {
2385 pr_err("error code is %d\n", ret);
2386 break;
2387 }
2388
2389 offset += field->size;
2390 }
2391 }
2392
2393 return ret;
2394 }
2395
2396 static int
2397 event_create_dir(struct dentry *parent, struct trace_event_file *file)
2398 {
2399 struct trace_event_call *call = file->event_call;
2400 struct trace_array *tr = file->tr;
2401 struct dentry *d_events;
2402 const char *name;
2403 int ret;
2404
2405 /*
2406 * If the trace point header did not define TRACE_SYSTEM
2407 * then the system would be called "TRACE_SYSTEM".
2408 */
2409 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
2410 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
2411 if (!d_events)
2412 return -ENOMEM;
2413 } else
2414 d_events = parent;
2415
2416 name = trace_event_name(call);
2417 file->dir = tracefs_create_dir(name, d_events);
2418 if (!file->dir) {
2419 pr_warn("Could not create tracefs '%s' directory\n", name);
2420 return -1;
2421 }
2422
2423 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2424 trace_create_file("enable", TRACE_MODE_WRITE, file->dir, file,
2425 &ftrace_enable_fops);
2426
2427 #ifdef CONFIG_PERF_EVENTS
2428 if (call->event.type && call->class->reg)
2429 trace_create_file("id", TRACE_MODE_READ, file->dir,
2430 (void *)(long)call->event.type,
2431 &ftrace_event_id_fops);
2432 #endif
2433
2434 ret = event_define_fields(call);
2435 if (ret < 0) {
2436 pr_warn("Could not initialize trace point events/%s\n", name);
2437 return ret;
2438 }
2439
2440 /*
2441 * Only event directories that can be enabled should have
2442 * triggers or filters.
2443 */
2444 if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
2445 trace_create_file("filter", TRACE_MODE_WRITE, file->dir,
2446 file, &ftrace_event_filter_fops);
2447
2448 trace_create_file("trigger", TRACE_MODE_WRITE, file->dir,
2449 file, &event_trigger_fops);
2450 }
2451
2452 #ifdef CONFIG_HIST_TRIGGERS
2453 trace_create_file("hist", TRACE_MODE_READ, file->dir, file,
2454 &event_hist_fops);
2455 #endif
2456 #ifdef CONFIG_HIST_TRIGGERS_DEBUG
2457 trace_create_file("hist_debug", TRACE_MODE_READ, file->dir, file,
2458 &event_hist_debug_fops);
2459 #endif
2460 trace_create_file("format", TRACE_MODE_READ, file->dir, call,
2461 &ftrace_event_format_fops);
2462
2463 #ifdef CONFIG_TRACE_EVENT_INJECT
2464 if (call->event.type && call->class->reg)
2465 trace_create_file("inject", 0200, file->dir, file,
2466 &event_inject_fops);
2467 #endif
2468
2469 return 0;
2470 }
2471
2472 static void remove_event_from_tracers(struct trace_event_call *call)
2473 {
2474 struct trace_event_file *file;
2475 struct trace_array *tr;
2476
2477 do_for_each_event_file_safe(tr, file) {
2478 if (file->event_call != call)
2479 continue;
2480
2481 remove_event_file_dir(file);
2482 /*
2483 * The do_for_each_event_file_safe() is
2484 * a double loop. After finding the call for this
2485 * trace_array, we use break to jump to the next
2486 * trace_array.
2487 */
2488 break;
2489 } while_for_each_event_file();
2490 }
2491
2492 static void event_remove(struct trace_event_call *call)
2493 {
2494 struct trace_array *tr;
2495 struct trace_event_file *file;
2496
2497 do_for_each_event_file(tr, file) {
2498 if (file->event_call != call)
2499 continue;
2500
2501 if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
2502 tr->clear_trace = true;
2503
2504 ftrace_event_enable_disable(file, 0);
2505 /*
2506 * The do_for_each_event_file() is
2507 * a double loop. After finding the call for this
2508 * trace_array, we use break to jump to the next
2509 * trace_array.
2510 */
2511 break;
2512 } while_for_each_event_file();
2513
2514 if (call->event.funcs)
2515 __unregister_trace_event(&call->event);
2516 remove_event_from_tracers(call);
2517 list_del(&call->list);
2518 }
2519
2520 static int event_init(struct trace_event_call *call)
2521 {
2522 int ret = 0;
2523 const char *name;
2524
2525 name = trace_event_name(call);
2526 if (WARN_ON(!name))
2527 return -EINVAL;
2528
2529 if (call->class->raw_init) {
2530 ret = call->class->raw_init(call);
2531 if (ret < 0 && ret != -ENOSYS)
2532 pr_warn("Could not initialize trace events/%s\n", name);
2533 }
2534
2535 return ret;
2536 }
2537
2538 static int
2539 __register_event(struct trace_event_call *call, struct module *mod)
2540 {
2541 int ret;
2542
2543 ret = event_init(call);
2544 if (ret < 0)
2545 return ret;
2546
2547 list_add(&call->list, &ftrace_events);
2548 if (call->flags & TRACE_EVENT_FL_DYNAMIC)
2549 atomic_set(&call->refcnt, 0);
2550 else
2551 call->module = mod;
2552
2553 return 0;
2554 }
2555
2556 static char *eval_replace(char *ptr, struct trace_eval_map *map, int len)
2557 {
2558 int rlen;
2559 int elen;
2560
2561 /* Find the length of the eval value as a string */
2562 elen = snprintf(ptr, 0, "%ld", map->eval_value);
2563 /* Make sure there's enough room to replace the string with the value */
2564 if (len < elen)
2565 return NULL;
2566
2567 snprintf(ptr, elen + 1, "%ld", map->eval_value);
2568
2569 /* Get the rest of the string of ptr */
2570 rlen = strlen(ptr + len);
2571 memmove(ptr + elen, ptr + len, rlen);
2572 /* Make sure we end the new string */
2573 ptr[elen + rlen] = 0;
2574
2575 return ptr + elen;
2576 }
2577
2578 static void update_event_printk(struct trace_event_call *call,
2579 struct trace_eval_map *map)
2580 {
2581 char *ptr;
2582 int quote = 0;
2583 int len = strlen(map->eval_string);
2584
2585 for (ptr = call->print_fmt; *ptr; ptr++) {
2586 if (*ptr == '\\') {
2587 ptr++;
2588 /* paranoid */
2589 if (!*ptr)
2590 break;
2591 continue;
2592 }
2593 if (*ptr == '"') {
2594 quote ^= 1;
2595 continue;
2596 }
2597 if (quote)
2598 continue;
2599 if (isdigit(*ptr)) {
2600 /* skip numbers */
2601 do {
2602 ptr++;
2603 /* Check for alpha chars like ULL */
2604 } while (isalnum(*ptr));
2605 if (!*ptr)
2606 break;
2607 /*
2608 * A number must have some kind of delimiter after
2609 * it, and we can ignore that too.
2610 */
2611 continue;
2612 }
2613 if (isalpha(*ptr) || *ptr == '_') {
2614 if (strncmp(map->eval_string, ptr, len) == 0 &&
2615 !isalnum(ptr[len]) && ptr[len] != '_') {
2616 ptr = eval_replace(ptr, map, len);
2617 /* enum/sizeof string smaller than value */
2618 if (WARN_ON_ONCE(!ptr))
2619 return;
2620 /*
2621 * No need to decrement here, as eval_replace()
2622 * returns the pointer to the character passed
2623 * the eval, and two evals can not be placed
2624 * back to back without something in between.
2625 * We can skip that something in between.
2626 */
2627 continue;
2628 }
2629 skip_more:
2630 do {
2631 ptr++;
2632 } while (isalnum(*ptr) || *ptr == '_');
2633 if (!*ptr)
2634 break;
2635 /*
2636 * If what comes after this variable is a '.' or
2637 * '->' then we can continue to ignore that string.
2638 */
2639 if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2640 ptr += *ptr == '.' ? 1 : 2;
2641 if (!*ptr)
2642 break;
2643 goto skip_more;
2644 }
2645 /*
2646 * Once again, we can skip the delimiter that came
2647 * after the string.
2648 */
2649 continue;
2650 }
2651 }
2652 }
2653
2654 static void add_str_to_module(struct module *module, char *str)
2655 {
2656 struct module_string *modstr;
2657
2658 modstr = kmalloc(sizeof(*modstr), GFP_KERNEL);
2659
2660 /*
2661 * If we failed to allocate memory here, then we'll just
2662 * let the str memory leak when the module is removed.
2663 * If this fails to allocate, there's worse problems than
2664 * a leaked string on module removal.
2665 */
2666 if (WARN_ON_ONCE(!modstr))
2667 return;
2668
2669 modstr->module = module;
2670 modstr->str = str;
2671
2672 list_add(&modstr->next, &module_strings);
2673 }
2674
2675 static void update_event_fields(struct trace_event_call *call,
2676 struct trace_eval_map *map)
2677 {
2678 struct ftrace_event_field *field;
2679 struct list_head *head;
2680 char *ptr;
2681 char *str;
2682 int len = strlen(map->eval_string);
2683
2684 /* Dynamic events should never have field maps */
2685 if (WARN_ON_ONCE(call->flags & TRACE_EVENT_FL_DYNAMIC))
2686 return;
2687
2688 head = trace_get_fields(call);
2689 list_for_each_entry(field, head, link) {
2690 ptr = strchr(field->type, '[');
2691 if (!ptr)
2692 continue;
2693 ptr++;
2694
2695 if (!isalpha(*ptr) && *ptr != '_')
2696 continue;
2697
2698 if (strncmp(map->eval_string, ptr, len) != 0)
2699 continue;
2700
2701 str = kstrdup(field->type, GFP_KERNEL);
2702 if (WARN_ON_ONCE(!str))
2703 return;
2704 ptr = str + (ptr - field->type);
2705 ptr = eval_replace(ptr, map, len);
2706 /* enum/sizeof string smaller than value */
2707 if (WARN_ON_ONCE(!ptr)) {
2708 kfree(str);
2709 continue;
2710 }
2711
2712 /*
2713 * If the event is part of a module, then we need to free the string
2714 * when the module is removed. Otherwise, it will stay allocated
2715 * until a reboot.
2716 */
2717 if (call->module)
2718 add_str_to_module(call->module, str);
2719
2720 field->type = str;
2721 }
2722 }
2723
2724 void trace_event_eval_update(struct trace_eval_map **map, int len)
2725 {
2726 struct trace_event_call *call, *p;
2727 const char *last_system = NULL;
2728 bool first = false;
2729 int last_i;
2730 int i;
2731
2732 down_write(&trace_event_sem);
2733 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2734 /* events are usually grouped together with systems */
2735 if (!last_system || call->class->system != last_system) {
2736 first = true;
2737 last_i = 0;
2738 last_system = call->class->system;
2739 }
2740
2741 /*
2742 * Since calls are grouped by systems, the likelihood that the
2743 * next call in the iteration belongs to the same system as the
2744 * previous call is high. As an optimization, we skip searching
2745 * for a map[] that matches the call's system if the last call
2746 * was from the same system. That's what last_i is for. If the
2747 * call has the same system as the previous call, then last_i
2748 * will be the index of the first map[] that has a matching
2749 * system.
2750 */
2751 for (i = last_i; i < len; i++) {
2752 if (call->class->system == map[i]->system) {
2753 /* Save the first system if need be */
2754 if (first) {
2755 last_i = i;
2756 first = false;
2757 }
2758 update_event_printk(call, map[i]);
2759 update_event_fields(call, map[i]);
2760 }
2761 }
2762 }
2763 up_write(&trace_event_sem);
2764 }
2765
2766 static struct trace_event_file *
2767 trace_create_new_event(struct trace_event_call *call,
2768 struct trace_array *tr)
2769 {
2770 struct trace_pid_list *no_pid_list;
2771 struct trace_pid_list *pid_list;
2772 struct trace_event_file *file;
2773 unsigned int first;
2774
2775 file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2776 if (!file)
2777 return NULL;
2778
2779 pid_list = rcu_dereference_protected(tr->filtered_pids,
2780 lockdep_is_held(&event_mutex));
2781 no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
2782 lockdep_is_held(&event_mutex));
2783
2784 if (!trace_pid_list_first(pid_list, &first) ||
2785 !trace_pid_list_first(no_pid_list, &first))
2786 file->flags |= EVENT_FILE_FL_PID_FILTER;
2787
2788 file->event_call = call;
2789 file->tr = tr;
2790 atomic_set(&file->sm_ref, 0);
2791 atomic_set(&file->tm_ref, 0);
2792 INIT_LIST_HEAD(&file->triggers);
2793 list_add(&file->list, &tr->events);
2794
2795 return file;
2796 }
2797
2798 /* Add an event to a trace directory */
2799 static int
2800 __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2801 {
2802 struct trace_event_file *file;
2803
2804 file = trace_create_new_event(call, tr);
2805 if (!file)
2806 return -ENOMEM;
2807
2808 if (eventdir_initialized)
2809 return event_create_dir(tr->event_dir, file);
2810 else
2811 return event_define_fields(call);
2812 }
2813
2814 /*
2815 * Just create a descriptor for early init. A descriptor is required
2816 * for enabling events at boot. We want to enable events before
2817 * the filesystem is initialized.
2818 */
2819 static int
2820 __trace_early_add_new_event(struct trace_event_call *call,
2821 struct trace_array *tr)
2822 {
2823 struct trace_event_file *file;
2824
2825 file = trace_create_new_event(call, tr);
2826 if (!file)
2827 return -ENOMEM;
2828
2829 return event_define_fields(call);
2830 }
2831
2832 struct ftrace_module_file_ops;
2833 static void __add_event_to_tracers(struct trace_event_call *call);
2834
2835 /* Add an additional event_call dynamically */
2836 int trace_add_event_call(struct trace_event_call *call)
2837 {
2838 int ret;
2839 lockdep_assert_held(&event_mutex);
2840
2841 mutex_lock(&trace_types_lock);
2842
2843 ret = __register_event(call, NULL);
2844 if (ret >= 0)
2845 __add_event_to_tracers(call);
2846
2847 mutex_unlock(&trace_types_lock);
2848 return ret;
2849 }
2850 EXPORT_SYMBOL_GPL(trace_add_event_call);
2851
2852 /*
2853 * Must be called under locking of trace_types_lock, event_mutex and
2854 * trace_event_sem.
2855 */
2856 static void __trace_remove_event_call(struct trace_event_call *call)
2857 {
2858 event_remove(call);
2859 trace_destroy_fields(call);
2860 free_event_filter(call->filter);
2861 call->filter = NULL;
2862 }
2863
2864 static int probe_remove_event_call(struct trace_event_call *call)
2865 {
2866 struct trace_array *tr;
2867 struct trace_event_file *file;
2868
2869 #ifdef CONFIG_PERF_EVENTS
2870 if (call->perf_refcount)
2871 return -EBUSY;
2872 #endif
2873 do_for_each_event_file(tr, file) {
2874 if (file->event_call != call)
2875 continue;
2876 /*
2877 * We can't rely on ftrace_event_enable_disable(enable => 0)
2878 * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2879 * TRACE_REG_UNREGISTER.
2880 */
2881 if (file->flags & EVENT_FILE_FL_ENABLED)
2882 return -EBUSY;
2883 /*
2884 * The do_for_each_event_file_safe() is
2885 * a double loop. After finding the call for this
2886 * trace_array, we use break to jump to the next
2887 * trace_array.
2888 */
2889 break;
2890 } while_for_each_event_file();
2891
2892 __trace_remove_event_call(call);
2893
2894 return 0;
2895 }
2896
2897 /* Remove an event_call */
2898 int trace_remove_event_call(struct trace_event_call *call)
2899 {
2900 int ret;
2901
2902 lockdep_assert_held(&event_mutex);
2903
2904 mutex_lock(&trace_types_lock);
2905 down_write(&trace_event_sem);
2906 ret = probe_remove_event_call(call);
2907 up_write(&trace_event_sem);
2908 mutex_unlock(&trace_types_lock);
2909
2910 return ret;
2911 }
2912 EXPORT_SYMBOL_GPL(trace_remove_event_call);
2913
2914 #define for_each_event(event, start, end) \
2915 for (event = start; \
2916 (unsigned long)event < (unsigned long)end; \
2917 event++)
2918
2919 #ifdef CONFIG_MODULES
2920
2921 static void trace_module_add_events(struct module *mod)
2922 {
2923 struct trace_event_call **call, **start, **end;
2924
2925 if (!mod->num_trace_events)
2926 return;
2927
2928 /* Don't add infrastructure for mods without tracepoints */
2929 if (trace_module_has_bad_taint(mod)) {
2930 pr_err("%s: module has bad taint, not creating trace events\n",
2931 mod->name);
2932 return;
2933 }
2934
2935 start = mod->trace_events;
2936 end = mod->trace_events + mod->num_trace_events;
2937
2938 for_each_event(call, start, end) {
2939 __register_event(*call, mod);
2940 __add_event_to_tracers(*call);
2941 }
2942 }
2943
2944 static void trace_module_remove_events(struct module *mod)
2945 {
2946 struct trace_event_call *call, *p;
2947 struct module_string *modstr, *m;
2948
2949 down_write(&trace_event_sem);
2950 list_for_each_entry_safe(call, p, &ftrace_events, list) {
2951 if ((call->flags & TRACE_EVENT_FL_DYNAMIC) || !call->module)
2952 continue;
2953 if (call->module == mod)
2954 __trace_remove_event_call(call);
2955 }
2956 /* Check for any strings allocade for this module */
2957 list_for_each_entry_safe(modstr, m, &module_strings, next) {
2958 if (modstr->module != mod)
2959 continue;
2960 list_del(&modstr->next);
2961 kfree(modstr->str);
2962 kfree(modstr);
2963 }
2964 up_write(&trace_event_sem);
2965
2966 /*
2967 * It is safest to reset the ring buffer if the module being unloaded
2968 * registered any events that were used. The only worry is if
2969 * a new module gets loaded, and takes on the same id as the events
2970 * of this module. When printing out the buffer, traced events left
2971 * over from this module may be passed to the new module events and
2972 * unexpected results may occur.
2973 */
2974 tracing_reset_all_online_cpus();
2975 }
2976
2977 static int trace_module_notify(struct notifier_block *self,
2978 unsigned long val, void *data)
2979 {
2980 struct module *mod = data;
2981
2982 mutex_lock(&event_mutex);
2983 mutex_lock(&trace_types_lock);
2984 switch (val) {
2985 case MODULE_STATE_COMING:
2986 trace_module_add_events(mod);
2987 break;
2988 case MODULE_STATE_GOING:
2989 trace_module_remove_events(mod);
2990 break;
2991 }
2992 mutex_unlock(&trace_types_lock);
2993 mutex_unlock(&event_mutex);
2994
2995 return NOTIFY_OK;
2996 }
2997
2998 static struct notifier_block trace_module_nb = {
2999 .notifier_call = trace_module_notify,
3000 .priority = 1, /* higher than trace.c module notify */
3001 };
3002 #endif /* CONFIG_MODULES */
3003
3004 /* Create a new event directory structure for a trace directory. */
3005 static void
3006 __trace_add_event_dirs(struct trace_array *tr)
3007 {
3008 struct trace_event_call *call;
3009 int ret;
3010
3011 list_for_each_entry(call, &ftrace_events, list) {
3012 ret = __trace_add_new_event(call, tr);
3013 if (ret < 0)
3014 pr_warn("Could not create directory for event %s\n",
3015 trace_event_name(call));
3016 }
3017 }
3018
3019 /* Returns any file that matches the system and event */
3020 struct trace_event_file *
3021 __find_event_file(struct trace_array *tr, const char *system, const char *event)
3022 {
3023 struct trace_event_file *file;
3024 struct trace_event_call *call;
3025 const char *name;
3026
3027 list_for_each_entry(file, &tr->events, list) {
3028
3029 call = file->event_call;
3030 name = trace_event_name(call);
3031
3032 if (!name || !call->class)
3033 continue;
3034
3035 if (strcmp(event, name) == 0 &&
3036 strcmp(system, call->class->system) == 0)
3037 return file;
3038 }
3039 return NULL;
3040 }
3041
3042 /* Returns valid trace event files that match system and event */
3043 struct trace_event_file *
3044 find_event_file(struct trace_array *tr, const char *system, const char *event)
3045 {
3046 struct trace_event_file *file;
3047
3048 file = __find_event_file(tr, system, event);
3049 if (!file || !file->event_call->class->reg ||
3050 file->event_call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
3051 return NULL;
3052
3053 return file;
3054 }
3055
3056 /**
3057 * trace_get_event_file - Find and return a trace event file
3058 * @instance: The name of the trace instance containing the event
3059 * @system: The name of the system containing the event
3060 * @event: The name of the event
3061 *
3062 * Return a trace event file given the trace instance name, trace
3063 * system, and trace event name. If the instance name is NULL, it
3064 * refers to the top-level trace array.
3065 *
3066 * This function will look it up and return it if found, after calling
3067 * trace_array_get() to prevent the instance from going away, and
3068 * increment the event's module refcount to prevent it from being
3069 * removed.
3070 *
3071 * To release the file, call trace_put_event_file(), which will call
3072 * trace_array_put() and decrement the event's module refcount.
3073 *
3074 * Return: The trace event on success, ERR_PTR otherwise.
3075 */
3076 struct trace_event_file *trace_get_event_file(const char *instance,
3077 const char *system,
3078 const char *event)
3079 {
3080 struct trace_array *tr = top_trace_array();
3081 struct trace_event_file *file = NULL;
3082 int ret = -EINVAL;
3083
3084 if (instance) {
3085 tr = trace_array_find_get(instance);
3086 if (!tr)
3087 return ERR_PTR(-ENOENT);
3088 } else {
3089 ret = trace_array_get(tr);
3090 if (ret)
3091 return ERR_PTR(ret);
3092 }
3093
3094 mutex_lock(&event_mutex);
3095
3096 file = find_event_file(tr, system, event);
3097 if (!file) {
3098 trace_array_put(tr);
3099 ret = -EINVAL;
3100 goto out;
3101 }
3102
3103 /* Don't let event modules unload while in use */
3104 ret = trace_event_try_get_ref(file->event_call);
3105 if (!ret) {
3106 trace_array_put(tr);
3107 ret = -EBUSY;
3108 goto out;
3109 }
3110
3111 ret = 0;
3112 out:
3113 mutex_unlock(&event_mutex);
3114
3115 if (ret)
3116 file = ERR_PTR(ret);
3117
3118 return file;
3119 }
3120 EXPORT_SYMBOL_GPL(trace_get_event_file);
3121
3122 /**
3123 * trace_put_event_file - Release a file from trace_get_event_file()
3124 * @file: The trace event file
3125 *
3126 * If a file was retrieved using trace_get_event_file(), this should
3127 * be called when it's no longer needed. It will cancel the previous
3128 * trace_array_get() called by that function, and decrement the
3129 * event's module refcount.
3130 */
3131 void trace_put_event_file(struct trace_event_file *file)
3132 {
3133 mutex_lock(&event_mutex);
3134 trace_event_put_ref(file->event_call);
3135 mutex_unlock(&event_mutex);
3136
3137 trace_array_put(file->tr);
3138 }
3139 EXPORT_SYMBOL_GPL(trace_put_event_file);
3140
3141 #ifdef CONFIG_DYNAMIC_FTRACE
3142
3143 /* Avoid typos */
3144 #define ENABLE_EVENT_STR "enable_event"
3145 #define DISABLE_EVENT_STR "disable_event"
3146
3147 struct event_probe_data {
3148 struct trace_event_file *file;
3149 unsigned long count;
3150 int ref;
3151 bool enable;
3152 };
3153
3154 static void update_event_probe(struct event_probe_data *data)
3155 {
3156 if (data->enable)
3157 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
3158 else
3159 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
3160 }
3161
3162 static void
3163 event_enable_probe(unsigned long ip, unsigned long parent_ip,
3164 struct trace_array *tr, struct ftrace_probe_ops *ops,
3165 void *data)
3166 {
3167 struct ftrace_func_mapper *mapper = data;
3168 struct event_probe_data *edata;
3169 void **pdata;
3170
3171 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3172 if (!pdata || !*pdata)
3173 return;
3174
3175 edata = *pdata;
3176 update_event_probe(edata);
3177 }
3178
3179 static void
3180 event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
3181 struct trace_array *tr, struct ftrace_probe_ops *ops,
3182 void *data)
3183 {
3184 struct ftrace_func_mapper *mapper = data;
3185 struct event_probe_data *edata;
3186 void **pdata;
3187
3188 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3189 if (!pdata || !*pdata)
3190 return;
3191
3192 edata = *pdata;
3193
3194 if (!edata->count)
3195 return;
3196
3197 /* Skip if the event is in a state we want to switch to */
3198 if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
3199 return;
3200
3201 if (edata->count != -1)
3202 (edata->count)--;
3203
3204 update_event_probe(edata);
3205 }
3206
3207 static int
3208 event_enable_print(struct seq_file *m, unsigned long ip,
3209 struct ftrace_probe_ops *ops, void *data)
3210 {
3211 struct ftrace_func_mapper *mapper = data;
3212 struct event_probe_data *edata;
3213 void **pdata;
3214
3215 pdata = ftrace_func_mapper_find_ip(mapper, ip);
3216
3217 if (WARN_ON_ONCE(!pdata || !*pdata))
3218 return 0;
3219
3220 edata = *pdata;
3221
3222 seq_printf(m, "%ps:", (void *)ip);
3223
3224 seq_printf(m, "%s:%s:%s",
3225 edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
3226 edata->file->event_call->class->system,
3227 trace_event_name(edata->file->event_call));
3228
3229 if (edata->count == -1)
3230 seq_puts(m, ":unlimited\n");
3231 else
3232 seq_printf(m, ":count=%ld\n", edata->count);
3233
3234 return 0;
3235 }
3236
3237 static int
3238 event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
3239 unsigned long ip, void *init_data, void **data)
3240 {
3241 struct ftrace_func_mapper *mapper = *data;
3242 struct event_probe_data *edata = init_data;
3243 int ret;
3244
3245 if (!mapper) {
3246 mapper = allocate_ftrace_func_mapper();
3247 if (!mapper)
3248 return -ENODEV;
3249 *data = mapper;
3250 }
3251
3252 ret = ftrace_func_mapper_add_ip(mapper, ip, edata);
3253 if (ret < 0)
3254 return ret;
3255
3256 edata->ref++;
3257
3258 return 0;
3259 }
3260
3261 static int free_probe_data(void *data)
3262 {
3263 struct event_probe_data *edata = data;
3264
3265 edata->ref--;
3266 if (!edata->ref) {
3267 /* Remove the SOFT_MODE flag */
3268 __ftrace_event_enable_disable(edata->file, 0, 1);
3269 trace_event_put_ref(edata->file->event_call);
3270 kfree(edata);
3271 }
3272 return 0;
3273 }
3274
3275 static void
3276 event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
3277 unsigned long ip, void *data)
3278 {
3279 struct ftrace_func_mapper *mapper = data;
3280 struct event_probe_data *edata;
3281
3282 if (!ip) {
3283 if (!mapper)
3284 return;
3285 free_ftrace_func_mapper(mapper, free_probe_data);
3286 return;
3287 }
3288
3289 edata = ftrace_func_mapper_remove_ip(mapper, ip);
3290
3291 if (WARN_ON_ONCE(!edata))
3292 return;
3293
3294 if (WARN_ON_ONCE(edata->ref <= 0))
3295 return;
3296
3297 free_probe_data(edata);
3298 }
3299
3300 static struct ftrace_probe_ops event_enable_probe_ops = {
3301 .func = event_enable_probe,
3302 .print = event_enable_print,
3303 .init = event_enable_init,
3304 .free = event_enable_free,
3305 };
3306
3307 static struct ftrace_probe_ops event_enable_count_probe_ops = {
3308 .func = event_enable_count_probe,
3309 .print = event_enable_print,
3310 .init = event_enable_init,
3311 .free = event_enable_free,
3312 };
3313
3314 static struct ftrace_probe_ops event_disable_probe_ops = {
3315 .func = event_enable_probe,
3316 .print = event_enable_print,
3317 .init = event_enable_init,
3318 .free = event_enable_free,
3319 };
3320
3321 static struct ftrace_probe_ops event_disable_count_probe_ops = {
3322 .func = event_enable_count_probe,
3323 .print = event_enable_print,
3324 .init = event_enable_init,
3325 .free = event_enable_free,
3326 };
3327
3328 static int
3329 event_enable_func(struct trace_array *tr, struct ftrace_hash *hash,
3330 char *glob, char *cmd, char *param, int enabled)
3331 {
3332 struct trace_event_file *file;
3333 struct ftrace_probe_ops *ops;
3334 struct event_probe_data *data;
3335 const char *system;
3336 const char *event;
3337 char *number;
3338 bool enable;
3339 int ret;
3340
3341 if (!tr)
3342 return -ENODEV;
3343
3344 /* hash funcs only work with set_ftrace_filter */
3345 if (!enabled || !param)
3346 return -EINVAL;
3347
3348 system = strsep(&param, ":");
3349 if (!param)
3350 return -EINVAL;
3351
3352 event = strsep(&param, ":");
3353
3354 mutex_lock(&event_mutex);
3355
3356 ret = -EINVAL;
3357 file = find_event_file(tr, system, event);
3358 if (!file)
3359 goto out;
3360
3361 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
3362
3363 if (enable)
3364 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
3365 else
3366 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
3367
3368 if (glob[0] == '!') {
3369 ret = unregister_ftrace_function_probe_func(glob+1, tr, ops);
3370 goto out;
3371 }
3372
3373 ret = -ENOMEM;
3374
3375 data = kzalloc(sizeof(*data), GFP_KERNEL);
3376 if (!data)
3377 goto out;
3378
3379 data->enable = enable;
3380 data->count = -1;
3381 data->file = file;
3382
3383 if (!param)
3384 goto out_reg;
3385
3386 number = strsep(&param, ":");
3387
3388 ret = -EINVAL;
3389 if (!strlen(number))
3390 goto out_free;
3391
3392 /*
3393 * We use the callback data field (which is a pointer)
3394 * as our counter.
3395 */
3396 ret = kstrtoul(number, 0, &data->count);
3397 if (ret)
3398 goto out_free;
3399
3400 out_reg:
3401 /* Don't let event modules unload while probe registered */
3402 ret = trace_event_try_get_ref(file->event_call);
3403 if (!ret) {
3404 ret = -EBUSY;
3405 goto out_free;
3406 }
3407
3408 ret = __ftrace_event_enable_disable(file, 1, 1);
3409 if (ret < 0)
3410 goto out_put;
3411
3412 ret = register_ftrace_function_probe(glob, tr, ops, data);
3413 /*
3414 * The above returns on success the # of functions enabled,
3415 * but if it didn't find any functions it returns zero.
3416 * Consider no functions a failure too.
3417 */
3418 if (!ret) {
3419 ret = -ENOENT;
3420 goto out_disable;
3421 } else if (ret < 0)
3422 goto out_disable;
3423 /* Just return zero, not the number of enabled functions */
3424 ret = 0;
3425 out:
3426 mutex_unlock(&event_mutex);
3427 return ret;
3428
3429 out_disable:
3430 __ftrace_event_enable_disable(file, 0, 1);
3431 out_put:
3432 trace_event_put_ref(file->event_call);
3433 out_free:
3434 kfree(data);
3435 goto out;
3436 }
3437
3438 static struct ftrace_func_command event_enable_cmd = {
3439 .name = ENABLE_EVENT_STR,
3440 .func = event_enable_func,
3441 };
3442
3443 static struct ftrace_func_command event_disable_cmd = {
3444 .name = DISABLE_EVENT_STR,
3445 .func = event_enable_func,
3446 };
3447
3448 static __init int register_event_cmds(void)
3449 {
3450 int ret;
3451
3452 ret = register_ftrace_command(&event_enable_cmd);
3453 if (WARN_ON(ret < 0))
3454 return ret;
3455 ret = register_ftrace_command(&event_disable_cmd);
3456 if (WARN_ON(ret < 0))
3457 unregister_ftrace_command(&event_enable_cmd);
3458 return ret;
3459 }
3460 #else
3461 static inline int register_event_cmds(void) { return 0; }
3462 #endif /* CONFIG_DYNAMIC_FTRACE */
3463
3464 /*
3465 * The top level array and trace arrays created by boot-time tracing
3466 * have already had its trace_event_file descriptors created in order
3467 * to allow for early events to be recorded.
3468 * This function is called after the tracefs has been initialized,
3469 * and we now have to create the files associated to the events.
3470 */
3471 static void __trace_early_add_event_dirs(struct trace_array *tr)
3472 {
3473 struct trace_event_file *file;
3474 int ret;
3475
3476
3477 list_for_each_entry(file, &tr->events, list) {
3478 ret = event_create_dir(tr->event_dir, file);
3479 if (ret < 0)
3480 pr_warn("Could not create directory for event %s\n",
3481 trace_event_name(file->event_call));
3482 }
3483 }
3484
3485 /*
3486 * For early boot up, the top trace array and the trace arrays created
3487 * by boot-time tracing require to have a list of events that can be
3488 * enabled. This must be done before the filesystem is set up in order
3489 * to allow events to be traced early.
3490 */
3491 void __trace_early_add_events(struct trace_array *tr)
3492 {
3493 struct trace_event_call *call;
3494 int ret;
3495
3496 list_for_each_entry(call, &ftrace_events, list) {
3497 /* Early boot up should not have any modules loaded */
3498 if (!(call->flags & TRACE_EVENT_FL_DYNAMIC) &&
3499 WARN_ON_ONCE(call->module))
3500 continue;
3501
3502 ret = __trace_early_add_new_event(call, tr);
3503 if (ret < 0)
3504 pr_warn("Could not create early event %s\n",
3505 trace_event_name(call));
3506 }
3507 }
3508
3509 /* Remove the event directory structure for a trace directory. */
3510 static void
3511 __trace_remove_event_dirs(struct trace_array *tr)
3512 {
3513 struct trace_event_file *file, *next;
3514
3515 list_for_each_entry_safe(file, next, &tr->events, list)
3516 remove_event_file_dir(file);
3517 }
3518
3519 static void __add_event_to_tracers(struct trace_event_call *call)
3520 {
3521 struct trace_array *tr;
3522
3523 list_for_each_entry(tr, &ftrace_trace_arrays, list)
3524 __trace_add_new_event(call, tr);
3525 }
3526
3527 extern struct trace_event_call *__start_ftrace_events[];
3528 extern struct trace_event_call *__stop_ftrace_events[];
3529
3530 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
3531
3532 static __init int setup_trace_event(char *str)
3533 {
3534 strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
3535 ring_buffer_expanded = true;
3536 disable_tracing_selftest("running event tracing");
3537
3538 return 1;
3539 }
3540 __setup("trace_event=", setup_trace_event);
3541
3542 /* Expects to have event_mutex held when called */
3543 static int
3544 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
3545 {
3546 struct dentry *d_events;
3547 struct dentry *entry;
3548
3549 entry = trace_create_file("set_event", TRACE_MODE_WRITE, parent,
3550 tr, &ftrace_set_event_fops);
3551 if (!entry)
3552 return -ENOMEM;
3553
3554 d_events = tracefs_create_dir("events", parent);
3555 if (!d_events) {
3556 pr_warn("Could not create tracefs 'events' directory\n");
3557 return -ENOMEM;
3558 }
3559
3560 entry = trace_create_file("enable", TRACE_MODE_WRITE, d_events,
3561 tr, &ftrace_tr_enable_fops);
3562 if (!entry)
3563 return -ENOMEM;
3564
3565 /* There are not as crucial, just warn if they are not created */
3566
3567 trace_create_file("set_event_pid", TRACE_MODE_WRITE, parent,
3568 tr, &ftrace_set_event_pid_fops);
3569
3570 trace_create_file("set_event_notrace_pid",
3571 TRACE_MODE_WRITE, parent, tr,
3572 &ftrace_set_event_notrace_pid_fops);
3573
3574 /* ring buffer internal formats */
3575 trace_create_file("header_page", TRACE_MODE_READ, d_events,
3576 ring_buffer_print_page_header,
3577 &ftrace_show_header_fops);
3578
3579 trace_create_file("header_event", TRACE_MODE_READ, d_events,
3580 ring_buffer_print_entry_header,
3581 &ftrace_show_header_fops);
3582
3583 tr->event_dir = d_events;
3584
3585 return 0;
3586 }
3587
3588 /**
3589 * event_trace_add_tracer - add a instance of a trace_array to events
3590 * @parent: The parent dentry to place the files/directories for events in
3591 * @tr: The trace array associated with these events
3592 *
3593 * When a new instance is created, it needs to set up its events
3594 * directory, as well as other files associated with events. It also
3595 * creates the event hierarchy in the @parent/events directory.
3596 *
3597 * Returns 0 on success.
3598 *
3599 * Must be called with event_mutex held.
3600 */
3601 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
3602 {
3603 int ret;
3604
3605 lockdep_assert_held(&event_mutex);
3606
3607 ret = create_event_toplevel_files(parent, tr);
3608 if (ret)
3609 goto out;
3610
3611 down_write(&trace_event_sem);
3612 /* If tr already has the event list, it is initialized in early boot. */
3613 if (unlikely(!list_empty(&tr->events)))
3614 __trace_early_add_event_dirs(tr);
3615 else
3616 __trace_add_event_dirs(tr);
3617 up_write(&trace_event_sem);
3618
3619 out:
3620 return ret;
3621 }
3622
3623 /*
3624 * The top trace array already had its file descriptors created.
3625 * Now the files themselves need to be created.
3626 */
3627 static __init int
3628 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
3629 {
3630 int ret;
3631
3632 mutex_lock(&event_mutex);
3633
3634 ret = create_event_toplevel_files(parent, tr);
3635 if (ret)
3636 goto out_unlock;
3637
3638 down_write(&trace_event_sem);
3639 __trace_early_add_event_dirs(tr);
3640 up_write(&trace_event_sem);
3641
3642 out_unlock:
3643 mutex_unlock(&event_mutex);
3644
3645 return ret;
3646 }
3647
3648 /* Must be called with event_mutex held */
3649 int event_trace_del_tracer(struct trace_array *tr)
3650 {
3651 lockdep_assert_held(&event_mutex);
3652
3653 /* Disable any event triggers and associated soft-disabled events */
3654 clear_event_triggers(tr);
3655
3656 /* Clear the pid list */
3657 __ftrace_clear_event_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
3658
3659 /* Disable any running events */
3660 __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3661
3662 /* Make sure no more events are being executed */
3663 tracepoint_synchronize_unregister();
3664
3665 down_write(&trace_event_sem);
3666 __trace_remove_event_dirs(tr);
3667 tracefs_remove(tr->event_dir);
3668 up_write(&trace_event_sem);
3669
3670 tr->event_dir = NULL;
3671
3672 return 0;
3673 }
3674
3675 static __init int event_trace_memsetup(void)
3676 {
3677 field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3678 file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3679 return 0;
3680 }
3681
3682 static __init void
3683 early_enable_events(struct trace_array *tr, bool disable_first)
3684 {
3685 char *buf = bootup_event_buf;
3686 char *token;
3687 int ret;
3688
3689 while (true) {
3690 token = strsep(&buf, ",");
3691
3692 if (!token)
3693 break;
3694
3695 if (*token) {
3696 /* Restarting syscalls requires that we stop them first */
3697 if (disable_first)
3698 ftrace_set_clr_event(tr, token, 0);
3699
3700 ret = ftrace_set_clr_event(tr, token, 1);
3701 if (ret)
3702 pr_warn("Failed to enable trace event: %s\n", token);
3703 }
3704
3705 /* Put back the comma to allow this to be called again */
3706 if (buf)
3707 *(buf - 1) = ',';
3708 }
3709 }
3710
3711 static __init int event_trace_enable(void)
3712 {
3713 struct trace_array *tr = top_trace_array();
3714 struct trace_event_call **iter, *call;
3715 int ret;
3716
3717 if (!tr)
3718 return -ENODEV;
3719
3720 for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3721
3722 call = *iter;
3723 ret = event_init(call);
3724 if (!ret)
3725 list_add(&call->list, &ftrace_events);
3726 }
3727
3728 /*
3729 * We need the top trace array to have a working set of trace
3730 * points at early init, before the debug files and directories
3731 * are created. Create the file entries now, and attach them
3732 * to the actual file dentries later.
3733 */
3734 __trace_early_add_events(tr);
3735
3736 early_enable_events(tr, false);
3737
3738 trace_printk_start_comm();
3739
3740 register_event_cmds();
3741
3742 register_trigger_cmds();
3743
3744 return 0;
3745 }
3746
3747 /*
3748 * event_trace_enable() is called from trace_event_init() first to
3749 * initialize events and perhaps start any events that are on the
3750 * command line. Unfortunately, there are some events that will not
3751 * start this early, like the system call tracepoints that need
3752 * to set the %SYSCALL_WORK_SYSCALL_TRACEPOINT flag of pid 1. But
3753 * event_trace_enable() is called before pid 1 starts, and this flag
3754 * is never set, making the syscall tracepoint never get reached, but
3755 * the event is enabled regardless (and not doing anything).
3756 */
3757 static __init int event_trace_enable_again(void)
3758 {
3759 struct trace_array *tr;
3760
3761 tr = top_trace_array();
3762 if (!tr)
3763 return -ENODEV;
3764
3765 early_enable_events(tr, true);
3766
3767 return 0;
3768 }
3769
3770 early_initcall(event_trace_enable_again);
3771
3772 /* Init fields which doesn't related to the tracefs */
3773 static __init int event_trace_init_fields(void)
3774 {
3775 if (trace_define_generic_fields())
3776 pr_warn("tracing: Failed to allocated generic fields");
3777
3778 if (trace_define_common_fields())
3779 pr_warn("tracing: Failed to allocate common fields");
3780
3781 return 0;
3782 }
3783
3784 __init int event_trace_init(void)
3785 {
3786 struct trace_array *tr;
3787 int ret;
3788
3789 tr = top_trace_array();
3790 if (!tr)
3791 return -ENODEV;
3792
3793 trace_create_file("available_events", TRACE_MODE_READ,
3794 NULL, tr, &ftrace_avail_fops);
3795
3796 ret = early_event_add_tracer(NULL, tr);
3797 if (ret)
3798 return ret;
3799
3800 #ifdef CONFIG_MODULES
3801 ret = register_module_notifier(&trace_module_nb);
3802 if (ret)
3803 pr_warn("Failed to register trace events module notifier\n");
3804 #endif
3805
3806 eventdir_initialized = true;
3807
3808 return 0;
3809 }
3810
3811 void __init trace_event_init(void)
3812 {
3813 event_trace_memsetup();
3814 init_ftrace_syscalls();
3815 event_trace_enable();
3816 event_trace_init_fields();
3817 }
3818
3819 #ifdef CONFIG_EVENT_TRACE_STARTUP_TEST
3820
3821 static DEFINE_SPINLOCK(test_spinlock);
3822 static DEFINE_SPINLOCK(test_spinlock_irq);
3823 static DEFINE_MUTEX(test_mutex);
3824
3825 static __init void test_work(struct work_struct *dummy)
3826 {
3827 spin_lock(&test_spinlock);
3828 spin_lock_irq(&test_spinlock_irq);
3829 udelay(1);
3830 spin_unlock_irq(&test_spinlock_irq);
3831 spin_unlock(&test_spinlock);
3832
3833 mutex_lock(&test_mutex);
3834 msleep(1);
3835 mutex_unlock(&test_mutex);
3836 }
3837
3838 static __init int event_test_thread(void *unused)
3839 {
3840 void *test_malloc;
3841
3842 test_malloc = kmalloc(1234, GFP_KERNEL);
3843 if (!test_malloc)
3844 pr_info("failed to kmalloc\n");
3845
3846 schedule_on_each_cpu(test_work);
3847
3848 kfree(test_malloc);
3849
3850 set_current_state(TASK_INTERRUPTIBLE);
3851 while (!kthread_should_stop()) {
3852 schedule();
3853 set_current_state(TASK_INTERRUPTIBLE);
3854 }
3855 __set_current_state(TASK_RUNNING);
3856
3857 return 0;
3858 }
3859
3860 /*
3861 * Do various things that may trigger events.
3862 */
3863 static __init void event_test_stuff(void)
3864 {
3865 struct task_struct *test_thread;
3866
3867 test_thread = kthread_run(event_test_thread, NULL, "test-events");
3868 msleep(1);
3869 kthread_stop(test_thread);
3870 }
3871
3872 /*
3873 * For every trace event defined, we will test each trace point separately,
3874 * and then by groups, and finally all trace points.
3875 */
3876 static __init void event_trace_self_tests(void)
3877 {
3878 struct trace_subsystem_dir *dir;
3879 struct trace_event_file *file;
3880 struct trace_event_call *call;
3881 struct event_subsystem *system;
3882 struct trace_array *tr;
3883 int ret;
3884
3885 tr = top_trace_array();
3886 if (!tr)
3887 return;
3888
3889 pr_info("Running tests on trace events:\n");
3890
3891 list_for_each_entry(file, &tr->events, list) {
3892
3893 call = file->event_call;
3894
3895 /* Only test those that have a probe */
3896 if (!call->class || !call->class->probe)
3897 continue;
3898
3899 /*
3900 * Testing syscall events here is pretty useless, but
3901 * we still do it if configured. But this is time consuming.
3902 * What we really need is a user thread to perform the
3903 * syscalls as we test.
3904 */
3905 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3906 if (call->class->system &&
3907 strcmp(call->class->system, "syscalls") == 0)
3908 continue;
3909 #endif
3910
3911 pr_info("Testing event %s: ", trace_event_name(call));
3912
3913 /*
3914 * If an event is already enabled, someone is using
3915 * it and the self test should not be on.
3916 */
3917 if (file->flags & EVENT_FILE_FL_ENABLED) {
3918 pr_warn("Enabled event during self test!\n");
3919 WARN_ON_ONCE(1);
3920 continue;
3921 }
3922
3923 ftrace_event_enable_disable(file, 1);
3924 event_test_stuff();
3925 ftrace_event_enable_disable(file, 0);
3926
3927 pr_cont("OK\n");
3928 }
3929
3930 /* Now test at the sub system level */
3931
3932 pr_info("Running tests on trace event systems:\n");
3933
3934 list_for_each_entry(dir, &tr->systems, list) {
3935
3936 system = dir->subsystem;
3937
3938 /* the ftrace system is special, skip it */
3939 if (strcmp(system->name, "ftrace") == 0)
3940 continue;
3941
3942 pr_info("Testing event system %s: ", system->name);
3943
3944 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3945 if (WARN_ON_ONCE(ret)) {
3946 pr_warn("error enabling system %s\n",
3947 system->name);
3948 continue;
3949 }
3950
3951 event_test_stuff();
3952
3953 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3954 if (WARN_ON_ONCE(ret)) {
3955 pr_warn("error disabling system %s\n",
3956 system->name);
3957 continue;
3958 }
3959
3960 pr_cont("OK\n");
3961 }
3962
3963 /* Test with all events enabled */
3964
3965 pr_info("Running tests on all trace events:\n");
3966 pr_info("Testing all events: ");
3967
3968 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3969 if (WARN_ON_ONCE(ret)) {
3970 pr_warn("error enabling all events\n");
3971 return;
3972 }
3973
3974 event_test_stuff();
3975
3976 /* reset sysname */
3977 ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3978 if (WARN_ON_ONCE(ret)) {
3979 pr_warn("error disabling all events\n");
3980 return;
3981 }
3982
3983 pr_cont("OK\n");
3984 }
3985
3986 #ifdef CONFIG_FUNCTION_TRACER
3987
3988 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3989
3990 static struct trace_event_file event_trace_file __initdata;
3991
3992 static void __init
3993 function_test_events_call(unsigned long ip, unsigned long parent_ip,
3994 struct ftrace_ops *op, struct ftrace_regs *regs)
3995 {
3996 struct trace_buffer *buffer;
3997 struct ring_buffer_event *event;
3998 struct ftrace_entry *entry;
3999 unsigned int trace_ctx;
4000 long disabled;
4001 int cpu;
4002
4003 trace_ctx = tracing_gen_ctx();
4004 preempt_disable_notrace();
4005 cpu = raw_smp_processor_id();
4006 disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
4007
4008 if (disabled != 1)
4009 goto out;
4010
4011 event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
4012 TRACE_FN, sizeof(*entry),
4013 trace_ctx);
4014 if (!event)
4015 goto out;
4016 entry = ring_buffer_event_data(event);
4017 entry->ip = ip;
4018 entry->parent_ip = parent_ip;
4019
4020 event_trigger_unlock_commit(&event_trace_file, buffer, event,
4021 entry, trace_ctx);
4022 out:
4023 atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
4024 preempt_enable_notrace();
4025 }
4026
4027 static struct ftrace_ops trace_ops __initdata =
4028 {
4029 .func = function_test_events_call,
4030 };
4031
4032 static __init void event_trace_self_test_with_function(void)
4033 {
4034 int ret;
4035
4036 event_trace_file.tr = top_trace_array();
4037 if (WARN_ON(!event_trace_file.tr))
4038 return;
4039
4040 ret = register_ftrace_function(&trace_ops);
4041 if (WARN_ON(ret < 0)) {
4042 pr_info("Failed to enable function tracer for event tests\n");
4043 return;
4044 }
4045 pr_info("Running tests again, along with the function tracer\n");
4046 event_trace_self_tests();
4047 unregister_ftrace_function(&trace_ops);
4048 }
4049 #else
4050 static __init void event_trace_self_test_with_function(void)
4051 {
4052 }
4053 #endif
4054
4055 static __init int event_trace_self_tests_init(void)
4056 {
4057 if (!tracing_selftest_disabled) {
4058 event_trace_self_tests();
4059 event_trace_self_test_with_function();
4060 }
4061
4062 return 0;
4063 }
4064
4065 late_initcall(event_trace_self_tests_init);
4066
4067 #endif
Michael's Linux tree.