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8#include <linux/security.h>
9#include <linux/module.h>
10#include <linux/ctype.h>
11#include <linux/mutex.h>
12#include <linux/slab.h>
13#include <linux/rculist.h>
14
15#include "trace.h"
16
17static LIST_HEAD(trigger_commands);
18static DEFINE_MUTEX(trigger_cmd_mutex);
19
20void trigger_data_free(struct event_trigger_data *data)
21{
22 if (data->cmd_ops->set_filter)
23 data->cmd_ops->set_filter(NULL, data, NULL);
24
25
26 tracepoint_synchronize_unregister();
27
28 kfree(data);
29}
30
31
32
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53
54
55enum event_trigger_type
56event_triggers_call(struct trace_event_file *file, void *rec,
57 struct ring_buffer_event *event)
58{
59 struct event_trigger_data *data;
60 enum event_trigger_type tt = ETT_NONE;
61 struct event_filter *filter;
62
63 if (list_empty(&file->triggers))
64 return tt;
65
66 list_for_each_entry_rcu(data, &file->triggers, list) {
67 if (data->paused)
68 continue;
69 if (!rec) {
70 data->ops->func(data, rec, event);
71 continue;
72 }
73 filter = rcu_dereference_sched(data->filter);
74 if (filter && !filter_match_preds(filter, rec))
75 continue;
76 if (event_command_post_trigger(data->cmd_ops)) {
77 tt |= data->cmd_ops->trigger_type;
78 continue;
79 }
80 data->ops->func(data, rec, event);
81 }
82 return tt;
83}
84EXPORT_SYMBOL_GPL(event_triggers_call);
85
86
87
88
89
90
91
92
93
94
95
96
97
98void
99event_triggers_post_call(struct trace_event_file *file,
100 enum event_trigger_type tt)
101{
102 struct event_trigger_data *data;
103
104 list_for_each_entry_rcu(data, &file->triggers, list) {
105 if (data->paused)
106 continue;
107 if (data->cmd_ops->trigger_type & tt)
108 data->ops->func(data, NULL, NULL);
109 }
110}
111EXPORT_SYMBOL_GPL(event_triggers_post_call);
112
113#define SHOW_AVAILABLE_TRIGGERS (void *)(1UL)
114
115static void *trigger_next(struct seq_file *m, void *t, loff_t *pos)
116{
117 struct trace_event_file *event_file = event_file_data(m->private);
118
119 if (t == SHOW_AVAILABLE_TRIGGERS) {
120 (*pos)++;
121 return NULL;
122 }
123 return seq_list_next(t, &event_file->triggers, pos);
124}
125
126static void *trigger_start(struct seq_file *m, loff_t *pos)
127{
128 struct trace_event_file *event_file;
129
130
131 mutex_lock(&event_mutex);
132 event_file = event_file_data(m->private);
133 if (unlikely(!event_file))
134 return ERR_PTR(-ENODEV);
135
136 if (list_empty(&event_file->triggers))
137 return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL;
138
139 return seq_list_start(&event_file->triggers, *pos);
140}
141
142static void trigger_stop(struct seq_file *m, void *t)
143{
144 mutex_unlock(&event_mutex);
145}
146
147static int trigger_show(struct seq_file *m, void *v)
148{
149 struct event_trigger_data *data;
150 struct event_command *p;
151
152 if (v == SHOW_AVAILABLE_TRIGGERS) {
153 seq_puts(m, "# Available triggers:\n");
154 seq_putc(m, '#');
155 mutex_lock(&trigger_cmd_mutex);
156 list_for_each_entry_reverse(p, &trigger_commands, list)
157 seq_printf(m, " %s", p->name);
158 seq_putc(m, '\n');
159 mutex_unlock(&trigger_cmd_mutex);
160 return 0;
161 }
162
163 data = list_entry(v, struct event_trigger_data, list);
164 data->ops->print(m, data->ops, data);
165
166 return 0;
167}
168
169static const struct seq_operations event_triggers_seq_ops = {
170 .start = trigger_start,
171 .next = trigger_next,
172 .stop = trigger_stop,
173 .show = trigger_show,
174};
175
176static int event_trigger_regex_open(struct inode *inode, struct file *file)
177{
178 int ret;
179
180 ret = security_locked_down(LOCKDOWN_TRACEFS);
181 if (ret)
182 return ret;
183
184 mutex_lock(&event_mutex);
185
186 if (unlikely(!event_file_data(file))) {
187 mutex_unlock(&event_mutex);
188 return -ENODEV;
189 }
190
191 if ((file->f_mode & FMODE_WRITE) &&
192 (file->f_flags & O_TRUNC)) {
193 struct trace_event_file *event_file;
194 struct event_command *p;
195
196 event_file = event_file_data(file);
197
198 list_for_each_entry(p, &trigger_commands, list) {
199 if (p->unreg_all)
200 p->unreg_all(event_file);
201 }
202 }
203
204 if (file->f_mode & FMODE_READ) {
205 ret = seq_open(file, &event_triggers_seq_ops);
206 if (!ret) {
207 struct seq_file *m = file->private_data;
208 m->private = file;
209 }
210 }
211
212 mutex_unlock(&event_mutex);
213
214 return ret;
215}
216
217int trigger_process_regex(struct trace_event_file *file, char *buff)
218{
219 char *command, *next;
220 struct event_command *p;
221 int ret = -EINVAL;
222
223 next = buff = skip_spaces(buff);
224 command = strsep(&next, ": \t");
225 if (next) {
226 next = skip_spaces(next);
227 if (!*next)
228 next = NULL;
229 }
230 command = (command[0] != '!') ? command : command + 1;
231
232 mutex_lock(&trigger_cmd_mutex);
233 list_for_each_entry(p, &trigger_commands, list) {
234 if (strcmp(p->name, command) == 0) {
235 ret = p->func(p, file, buff, command, next);
236 goto out_unlock;
237 }
238 }
239 out_unlock:
240 mutex_unlock(&trigger_cmd_mutex);
241
242 return ret;
243}
244
245static ssize_t event_trigger_regex_write(struct file *file,
246 const char __user *ubuf,
247 size_t cnt, loff_t *ppos)
248{
249 struct trace_event_file *event_file;
250 ssize_t ret;
251 char *buf;
252
253 if (!cnt)
254 return 0;
255
256 if (cnt >= PAGE_SIZE)
257 return -EINVAL;
258
259 buf = memdup_user_nul(ubuf, cnt);
260 if (IS_ERR(buf))
261 return PTR_ERR(buf);
262
263 strim(buf);
264
265 mutex_lock(&event_mutex);
266 event_file = event_file_data(file);
267 if (unlikely(!event_file)) {
268 mutex_unlock(&event_mutex);
269 kfree(buf);
270 return -ENODEV;
271 }
272 ret = trigger_process_regex(event_file, buf);
273 mutex_unlock(&event_mutex);
274
275 kfree(buf);
276 if (ret < 0)
277 goto out;
278
279 *ppos += cnt;
280 ret = cnt;
281 out:
282 return ret;
283}
284
285static int event_trigger_regex_release(struct inode *inode, struct file *file)
286{
287 mutex_lock(&event_mutex);
288
289 if (file->f_mode & FMODE_READ)
290 seq_release(inode, file);
291
292 mutex_unlock(&event_mutex);
293
294 return 0;
295}
296
297static ssize_t
298event_trigger_write(struct file *filp, const char __user *ubuf,
299 size_t cnt, loff_t *ppos)
300{
301 return event_trigger_regex_write(filp, ubuf, cnt, ppos);
302}
303
304static int
305event_trigger_open(struct inode *inode, struct file *filp)
306{
307
308 return event_trigger_regex_open(inode, filp);
309}
310
311static int
312event_trigger_release(struct inode *inode, struct file *file)
313{
314 return event_trigger_regex_release(inode, file);
315}
316
317const struct file_operations event_trigger_fops = {
318 .open = event_trigger_open,
319 .read = seq_read,
320 .write = event_trigger_write,
321 .llseek = tracing_lseek,
322 .release = event_trigger_release,
323};
324
325
326
327
328
329__init int register_event_command(struct event_command *cmd)
330{
331 struct event_command *p;
332 int ret = 0;
333
334 mutex_lock(&trigger_cmd_mutex);
335 list_for_each_entry(p, &trigger_commands, list) {
336 if (strcmp(cmd->name, p->name) == 0) {
337 ret = -EBUSY;
338 goto out_unlock;
339 }
340 }
341 list_add(&cmd->list, &trigger_commands);
342 out_unlock:
343 mutex_unlock(&trigger_cmd_mutex);
344
345 return ret;
346}
347
348
349
350
351
352__init int unregister_event_command(struct event_command *cmd)
353{
354 struct event_command *p, *n;
355 int ret = -ENODEV;
356
357 mutex_lock(&trigger_cmd_mutex);
358 list_for_each_entry_safe(p, n, &trigger_commands, list) {
359 if (strcmp(cmd->name, p->name) == 0) {
360 ret = 0;
361 list_del_init(&p->list);
362 goto out_unlock;
363 }
364 }
365 out_unlock:
366 mutex_unlock(&trigger_cmd_mutex);
367
368 return ret;
369}
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385static int
386event_trigger_print(const char *name, struct seq_file *m,
387 void *data, char *filter_str)
388{
389 long count = (long)data;
390
391 seq_puts(m, name);
392
393 if (count == -1)
394 seq_puts(m, ":unlimited");
395 else
396 seq_printf(m, ":count=%ld", count);
397
398 if (filter_str)
399 seq_printf(m, " if %s\n", filter_str);
400 else
401 seq_putc(m, '\n');
402
403 return 0;
404}
405
406
407
408
409
410
411
412
413
414
415
416
417
418int event_trigger_init(struct event_trigger_ops *ops,
419 struct event_trigger_data *data)
420{
421 data->ref++;
422 return 0;
423}
424
425
426
427
428
429
430
431
432
433
434
435static void
436event_trigger_free(struct event_trigger_ops *ops,
437 struct event_trigger_data *data)
438{
439 if (WARN_ON_ONCE(data->ref <= 0))
440 return;
441
442 data->ref--;
443 if (!data->ref)
444 trigger_data_free(data);
445}
446
447int trace_event_trigger_enable_disable(struct trace_event_file *file,
448 int trigger_enable)
449{
450 int ret = 0;
451
452 if (trigger_enable) {
453 if (atomic_inc_return(&file->tm_ref) > 1)
454 return ret;
455 set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
456 ret = trace_event_enable_disable(file, 1, 1);
457 } else {
458 if (atomic_dec_return(&file->tm_ref) > 0)
459 return ret;
460 clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
461 ret = trace_event_enable_disable(file, 0, 1);
462 }
463
464 return ret;
465}
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480void
481clear_event_triggers(struct trace_array *tr)
482{
483 struct trace_event_file *file;
484
485 list_for_each_entry(file, &tr->events, list) {
486 struct event_trigger_data *data, *n;
487 list_for_each_entry_safe(data, n, &file->triggers, list) {
488 trace_event_trigger_enable_disable(file, 0);
489 list_del_rcu(&data->list);
490 if (data->ops->free)
491 data->ops->free(data->ops, data);
492 }
493 }
494}
495
496
497
498
499
500
501
502
503
504
505
506void update_cond_flag(struct trace_event_file *file)
507{
508 struct event_trigger_data *data;
509 bool set_cond = false;
510
511 lockdep_assert_held(&event_mutex);
512
513 list_for_each_entry(data, &file->triggers, list) {
514 if (data->filter || event_command_post_trigger(data->cmd_ops) ||
515 event_command_needs_rec(data->cmd_ops)) {
516 set_cond = true;
517 break;
518 }
519 }
520
521 if (set_cond)
522 set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
523 else
524 clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
525}
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541static int register_trigger(char *glob, struct event_trigger_ops *ops,
542 struct event_trigger_data *data,
543 struct trace_event_file *file)
544{
545 struct event_trigger_data *test;
546 int ret = 0;
547
548 lockdep_assert_held(&event_mutex);
549
550 list_for_each_entry(test, &file->triggers, list) {
551 if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) {
552 ret = -EEXIST;
553 goto out;
554 }
555 }
556
557 if (data->ops->init) {
558 ret = data->ops->init(data->ops, data);
559 if (ret < 0)
560 goto out;
561 }
562
563 list_add_rcu(&data->list, &file->triggers);
564 ret++;
565
566 update_cond_flag(file);
567 if (trace_event_trigger_enable_disable(file, 1) < 0) {
568 list_del_rcu(&data->list);
569 update_cond_flag(file);
570 ret--;
571 }
572out:
573 return ret;
574}
575
576
577
578
579
580
581
582
583
584
585
586
587
588static void unregister_trigger(char *glob, struct event_trigger_ops *ops,
589 struct event_trigger_data *test,
590 struct trace_event_file *file)
591{
592 struct event_trigger_data *data;
593 bool unregistered = false;
594
595 lockdep_assert_held(&event_mutex);
596
597 list_for_each_entry(data, &file->triggers, list) {
598 if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
599 unregistered = true;
600 list_del_rcu(&data->list);
601 trace_event_trigger_enable_disable(file, 0);
602 update_cond_flag(file);
603 break;
604 }
605 }
606
607 if (unregistered && data->ops->free)
608 data->ops->free(data->ops, data);
609}
610
611
612
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619
620
621
622
623
624
625
626
627static int
628event_trigger_callback(struct event_command *cmd_ops,
629 struct trace_event_file *file,
630 char *glob, char *cmd, char *param)
631{
632 struct event_trigger_data *trigger_data;
633 struct event_trigger_ops *trigger_ops;
634 char *trigger = NULL;
635 char *number;
636 int ret;
637
638
639 if (param && isdigit(param[0])) {
640 trigger = strsep(¶m, " \t");
641 if (param) {
642 param = skip_spaces(param);
643 if (!*param)
644 param = NULL;
645 }
646 }
647
648 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
649
650 ret = -ENOMEM;
651 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
652 if (!trigger_data)
653 goto out;
654
655 trigger_data->count = -1;
656 trigger_data->ops = trigger_ops;
657 trigger_data->cmd_ops = cmd_ops;
658 trigger_data->private_data = file;
659 INIT_LIST_HEAD(&trigger_data->list);
660 INIT_LIST_HEAD(&trigger_data->named_list);
661
662 if (glob[0] == '!') {
663 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
664 kfree(trigger_data);
665 ret = 0;
666 goto out;
667 }
668
669 if (trigger) {
670 number = strsep(&trigger, ":");
671
672 ret = -EINVAL;
673 if (!strlen(number))
674 goto out_free;
675
676
677
678
679
680 ret = kstrtoul(number, 0, &trigger_data->count);
681 if (ret)
682 goto out_free;
683 }
684
685 if (!param)
686 goto out_reg;
687
688 if (!cmd_ops->set_filter)
689 goto out_reg;
690
691 ret = cmd_ops->set_filter(param, trigger_data, file);
692 if (ret < 0)
693 goto out_free;
694
695 out_reg:
696
697 event_trigger_init(trigger_ops, trigger_data);
698 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
699
700
701
702
703
704 if (!ret) {
705 cmd_ops->unreg(glob, trigger_ops, trigger_data, file);
706 ret = -ENOENT;
707 } else if (ret > 0)
708 ret = 0;
709
710
711 event_trigger_free(trigger_ops, trigger_data);
712 out:
713 return ret;
714
715 out_free:
716 if (cmd_ops->set_filter)
717 cmd_ops->set_filter(NULL, trigger_data, NULL);
718 kfree(trigger_data);
719 goto out;
720}
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738int set_trigger_filter(char *filter_str,
739 struct event_trigger_data *trigger_data,
740 struct trace_event_file *file)
741{
742 struct event_trigger_data *data = trigger_data;
743 struct event_filter *filter = NULL, *tmp;
744 int ret = -EINVAL;
745 char *s;
746
747 if (!filter_str)
748 goto assign;
749
750 s = strsep(&filter_str, " \t");
751
752 if (!strlen(s) || strcmp(s, "if") != 0)
753 goto out;
754
755 if (!filter_str)
756 goto out;
757
758
759 ret = create_event_filter(file->tr, file->event_call,
760 filter_str, false, &filter);
761
762
763
764
765 assign:
766 tmp = rcu_access_pointer(data->filter);
767
768 rcu_assign_pointer(data->filter, filter);
769
770 if (tmp) {
771
772 tracepoint_synchronize_unregister();
773 free_event_filter(tmp);
774 }
775
776 kfree(data->filter_str);
777 data->filter_str = NULL;
778
779 if (filter_str) {
780 data->filter_str = kstrdup(filter_str, GFP_KERNEL);
781 if (!data->filter_str) {
782 free_event_filter(rcu_access_pointer(data->filter));
783 data->filter = NULL;
784 ret = -ENOMEM;
785 }
786 }
787 out:
788 return ret;
789}
790
791static LIST_HEAD(named_triggers);
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807struct event_trigger_data *find_named_trigger(const char *name)
808{
809 struct event_trigger_data *data;
810
811 if (!name)
812 return NULL;
813
814 list_for_each_entry(data, &named_triggers, named_list) {
815 if (data->named_data)
816 continue;
817 if (strcmp(data->name, name) == 0)
818 return data;
819 }
820
821 return NULL;
822}
823
824
825
826
827
828
829
830bool is_named_trigger(struct event_trigger_data *test)
831{
832 struct event_trigger_data *data;
833
834 list_for_each_entry(data, &named_triggers, named_list) {
835 if (test == data)
836 return true;
837 }
838
839 return false;
840}
841
842
843
844
845
846
847
848
849int save_named_trigger(const char *name, struct event_trigger_data *data)
850{
851 data->name = kstrdup(name, GFP_KERNEL);
852 if (!data->name)
853 return -ENOMEM;
854
855 list_add(&data->named_list, &named_triggers);
856
857 return 0;
858}
859
860
861
862
863
864void del_named_trigger(struct event_trigger_data *data)
865{
866 kfree(data->name);
867 data->name = NULL;
868
869 list_del(&data->named_list);
870}
871
872static void __pause_named_trigger(struct event_trigger_data *data, bool pause)
873{
874 struct event_trigger_data *test;
875
876 list_for_each_entry(test, &named_triggers, named_list) {
877 if (strcmp(test->name, data->name) == 0) {
878 if (pause) {
879 test->paused_tmp = test->paused;
880 test->paused = true;
881 } else {
882 test->paused = test->paused_tmp;
883 }
884 }
885 }
886}
887
888
889
890
891
892
893
894
895
896
897void pause_named_trigger(struct event_trigger_data *data)
898{
899 __pause_named_trigger(data, true);
900}
901
902
903
904
905
906
907
908
909
910
911void unpause_named_trigger(struct event_trigger_data *data)
912{
913 __pause_named_trigger(data, false);
914}
915
916
917
918
919
920
921
922
923
924
925
926
927void set_named_trigger_data(struct event_trigger_data *data,
928 struct event_trigger_data *named_data)
929{
930 data->named_data = named_data;
931}
932
933struct event_trigger_data *
934get_named_trigger_data(struct event_trigger_data *data)
935{
936 return data->named_data;
937}
938
939static void
940traceon_trigger(struct event_trigger_data *data, void *rec,
941 struct ring_buffer_event *event)
942{
943 if (tracing_is_on())
944 return;
945
946 tracing_on();
947}
948
949static void
950traceon_count_trigger(struct event_trigger_data *data, void *rec,
951 struct ring_buffer_event *event)
952{
953 if (tracing_is_on())
954 return;
955
956 if (!data->count)
957 return;
958
959 if (data->count != -1)
960 (data->count)--;
961
962 tracing_on();
963}
964
965static void
966traceoff_trigger(struct event_trigger_data *data, void *rec,
967 struct ring_buffer_event *event)
968{
969 if (!tracing_is_on())
970 return;
971
972 tracing_off();
973}
974
975static void
976traceoff_count_trigger(struct event_trigger_data *data, void *rec,
977 struct ring_buffer_event *event)
978{
979 if (!tracing_is_on())
980 return;
981
982 if (!data->count)
983 return;
984
985 if (data->count != -1)
986 (data->count)--;
987
988 tracing_off();
989}
990
991static int
992traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
993 struct event_trigger_data *data)
994{
995 return event_trigger_print("traceon", m, (void *)data->count,
996 data->filter_str);
997}
998
999static int
1000traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1001 struct event_trigger_data *data)
1002{
1003 return event_trigger_print("traceoff", m, (void *)data->count,
1004 data->filter_str);
1005}
1006
1007static struct event_trigger_ops traceon_trigger_ops = {
1008 .func = traceon_trigger,
1009 .print = traceon_trigger_print,
1010 .init = event_trigger_init,
1011 .free = event_trigger_free,
1012};
1013
1014static struct event_trigger_ops traceon_count_trigger_ops = {
1015 .func = traceon_count_trigger,
1016 .print = traceon_trigger_print,
1017 .init = event_trigger_init,
1018 .free = event_trigger_free,
1019};
1020
1021static struct event_trigger_ops traceoff_trigger_ops = {
1022 .func = traceoff_trigger,
1023 .print = traceoff_trigger_print,
1024 .init = event_trigger_init,
1025 .free = event_trigger_free,
1026};
1027
1028static struct event_trigger_ops traceoff_count_trigger_ops = {
1029 .func = traceoff_count_trigger,
1030 .print = traceoff_trigger_print,
1031 .init = event_trigger_init,
1032 .free = event_trigger_free,
1033};
1034
1035static struct event_trigger_ops *
1036onoff_get_trigger_ops(char *cmd, char *param)
1037{
1038 struct event_trigger_ops *ops;
1039
1040
1041 if (strcmp(cmd, "traceon") == 0)
1042 ops = param ? &traceon_count_trigger_ops :
1043 &traceon_trigger_ops;
1044 else
1045 ops = param ? &traceoff_count_trigger_ops :
1046 &traceoff_trigger_ops;
1047
1048 return ops;
1049}
1050
1051static struct event_command trigger_traceon_cmd = {
1052 .name = "traceon",
1053 .trigger_type = ETT_TRACE_ONOFF,
1054 .func = event_trigger_callback,
1055 .reg = register_trigger,
1056 .unreg = unregister_trigger,
1057 .get_trigger_ops = onoff_get_trigger_ops,
1058 .set_filter = set_trigger_filter,
1059};
1060
1061static struct event_command trigger_traceoff_cmd = {
1062 .name = "traceoff",
1063 .trigger_type = ETT_TRACE_ONOFF,
1064 .flags = EVENT_CMD_FL_POST_TRIGGER,
1065 .func = event_trigger_callback,
1066 .reg = register_trigger,
1067 .unreg = unregister_trigger,
1068 .get_trigger_ops = onoff_get_trigger_ops,
1069 .set_filter = set_trigger_filter,
1070};
1071
1072#ifdef CONFIG_TRACER_SNAPSHOT
1073static void
1074snapshot_trigger(struct event_trigger_data *data, void *rec,
1075 struct ring_buffer_event *event)
1076{
1077 struct trace_event_file *file = data->private_data;
1078
1079 if (file)
1080 tracing_snapshot_instance(file->tr);
1081 else
1082 tracing_snapshot();
1083}
1084
1085static void
1086snapshot_count_trigger(struct event_trigger_data *data, void *rec,
1087 struct ring_buffer_event *event)
1088{
1089 if (!data->count)
1090 return;
1091
1092 if (data->count != -1)
1093 (data->count)--;
1094
1095 snapshot_trigger(data, rec, event);
1096}
1097
1098static int
1099register_snapshot_trigger(char *glob, struct event_trigger_ops *ops,
1100 struct event_trigger_data *data,
1101 struct trace_event_file *file)
1102{
1103 if (tracing_alloc_snapshot_instance(file->tr) != 0)
1104 return 0;
1105
1106 return register_trigger(glob, ops, data, file);
1107}
1108
1109static int
1110snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1111 struct event_trigger_data *data)
1112{
1113 return event_trigger_print("snapshot", m, (void *)data->count,
1114 data->filter_str);
1115}
1116
1117static struct event_trigger_ops snapshot_trigger_ops = {
1118 .func = snapshot_trigger,
1119 .print = snapshot_trigger_print,
1120 .init = event_trigger_init,
1121 .free = event_trigger_free,
1122};
1123
1124static struct event_trigger_ops snapshot_count_trigger_ops = {
1125 .func = snapshot_count_trigger,
1126 .print = snapshot_trigger_print,
1127 .init = event_trigger_init,
1128 .free = event_trigger_free,
1129};
1130
1131static struct event_trigger_ops *
1132snapshot_get_trigger_ops(char *cmd, char *param)
1133{
1134 return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
1135}
1136
1137static struct event_command trigger_snapshot_cmd = {
1138 .name = "snapshot",
1139 .trigger_type = ETT_SNAPSHOT,
1140 .func = event_trigger_callback,
1141 .reg = register_snapshot_trigger,
1142 .unreg = unregister_trigger,
1143 .get_trigger_ops = snapshot_get_trigger_ops,
1144 .set_filter = set_trigger_filter,
1145};
1146
1147static __init int register_trigger_snapshot_cmd(void)
1148{
1149 int ret;
1150
1151 ret = register_event_command(&trigger_snapshot_cmd);
1152 WARN_ON(ret < 0);
1153
1154 return ret;
1155}
1156#else
1157static __init int register_trigger_snapshot_cmd(void) { return 0; }
1158#endif
1159
1160#ifdef CONFIG_STACKTRACE
1161#ifdef CONFIG_UNWINDER_ORC
1162
1163
1164
1165
1166# define STACK_SKIP 2
1167#else
1168
1169
1170
1171
1172
1173
1174
1175#define STACK_SKIP 4
1176#endif
1177
1178static void
1179stacktrace_trigger(struct event_trigger_data *data, void *rec,
1180 struct ring_buffer_event *event)
1181{
1182 trace_dump_stack(STACK_SKIP);
1183}
1184
1185static void
1186stacktrace_count_trigger(struct event_trigger_data *data, void *rec,
1187 struct ring_buffer_event *event)
1188{
1189 if (!data->count)
1190 return;
1191
1192 if (data->count != -1)
1193 (data->count)--;
1194
1195 stacktrace_trigger(data, rec, event);
1196}
1197
1198static int
1199stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1200 struct event_trigger_data *data)
1201{
1202 return event_trigger_print("stacktrace", m, (void *)data->count,
1203 data->filter_str);
1204}
1205
1206static struct event_trigger_ops stacktrace_trigger_ops = {
1207 .func = stacktrace_trigger,
1208 .print = stacktrace_trigger_print,
1209 .init = event_trigger_init,
1210 .free = event_trigger_free,
1211};
1212
1213static struct event_trigger_ops stacktrace_count_trigger_ops = {
1214 .func = stacktrace_count_trigger,
1215 .print = stacktrace_trigger_print,
1216 .init = event_trigger_init,
1217 .free = event_trigger_free,
1218};
1219
1220static struct event_trigger_ops *
1221stacktrace_get_trigger_ops(char *cmd, char *param)
1222{
1223 return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
1224}
1225
1226static struct event_command trigger_stacktrace_cmd = {
1227 .name = "stacktrace",
1228 .trigger_type = ETT_STACKTRACE,
1229 .flags = EVENT_CMD_FL_POST_TRIGGER,
1230 .func = event_trigger_callback,
1231 .reg = register_trigger,
1232 .unreg = unregister_trigger,
1233 .get_trigger_ops = stacktrace_get_trigger_ops,
1234 .set_filter = set_trigger_filter,
1235};
1236
1237static __init int register_trigger_stacktrace_cmd(void)
1238{
1239 int ret;
1240
1241 ret = register_event_command(&trigger_stacktrace_cmd);
1242 WARN_ON(ret < 0);
1243
1244 return ret;
1245}
1246#else
1247static __init int register_trigger_stacktrace_cmd(void) { return 0; }
1248#endif
1249
1250static __init void unregister_trigger_traceon_traceoff_cmds(void)
1251{
1252 unregister_event_command(&trigger_traceon_cmd);
1253 unregister_event_command(&trigger_traceoff_cmd);
1254}
1255
1256static void
1257event_enable_trigger(struct event_trigger_data *data, void *rec,
1258 struct ring_buffer_event *event)
1259{
1260 struct enable_trigger_data *enable_data = data->private_data;
1261
1262 if (enable_data->enable)
1263 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1264 else
1265 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1266}
1267
1268static void
1269event_enable_count_trigger(struct event_trigger_data *data, void *rec,
1270 struct ring_buffer_event *event)
1271{
1272 struct enable_trigger_data *enable_data = data->private_data;
1273
1274 if (!data->count)
1275 return;
1276
1277
1278 if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
1279 return;
1280
1281 if (data->count != -1)
1282 (data->count)--;
1283
1284 event_enable_trigger(data, rec, event);
1285}
1286
1287int event_enable_trigger_print(struct seq_file *m,
1288 struct event_trigger_ops *ops,
1289 struct event_trigger_data *data)
1290{
1291 struct enable_trigger_data *enable_data = data->private_data;
1292
1293 seq_printf(m, "%s:%s:%s",
1294 enable_data->hist ?
1295 (enable_data->enable ? ENABLE_HIST_STR : DISABLE_HIST_STR) :
1296 (enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR),
1297 enable_data->file->event_call->class->system,
1298 trace_event_name(enable_data->file->event_call));
1299
1300 if (data->count == -1)
1301 seq_puts(m, ":unlimited");
1302 else
1303 seq_printf(m, ":count=%ld", data->count);
1304
1305 if (data->filter_str)
1306 seq_printf(m, " if %s\n", data->filter_str);
1307 else
1308 seq_putc(m, '\n');
1309
1310 return 0;
1311}
1312
1313void event_enable_trigger_free(struct event_trigger_ops *ops,
1314 struct event_trigger_data *data)
1315{
1316 struct enable_trigger_data *enable_data = data->private_data;
1317
1318 if (WARN_ON_ONCE(data->ref <= 0))
1319 return;
1320
1321 data->ref--;
1322 if (!data->ref) {
1323
1324 trace_event_enable_disable(enable_data->file, 0, 1);
1325 module_put(enable_data->file->event_call->mod);
1326 trigger_data_free(data);
1327 kfree(enable_data);
1328 }
1329}
1330
1331static struct event_trigger_ops event_enable_trigger_ops = {
1332 .func = event_enable_trigger,
1333 .print = event_enable_trigger_print,
1334 .init = event_trigger_init,
1335 .free = event_enable_trigger_free,
1336};
1337
1338static struct event_trigger_ops event_enable_count_trigger_ops = {
1339 .func = event_enable_count_trigger,
1340 .print = event_enable_trigger_print,
1341 .init = event_trigger_init,
1342 .free = event_enable_trigger_free,
1343};
1344
1345static struct event_trigger_ops event_disable_trigger_ops = {
1346 .func = event_enable_trigger,
1347 .print = event_enable_trigger_print,
1348 .init = event_trigger_init,
1349 .free = event_enable_trigger_free,
1350};
1351
1352static struct event_trigger_ops event_disable_count_trigger_ops = {
1353 .func = event_enable_count_trigger,
1354 .print = event_enable_trigger_print,
1355 .init = event_trigger_init,
1356 .free = event_enable_trigger_free,
1357};
1358
1359int event_enable_trigger_func(struct event_command *cmd_ops,
1360 struct trace_event_file *file,
1361 char *glob, char *cmd, char *param)
1362{
1363 struct trace_event_file *event_enable_file;
1364 struct enable_trigger_data *enable_data;
1365 struct event_trigger_data *trigger_data;
1366 struct event_trigger_ops *trigger_ops;
1367 struct trace_array *tr = file->tr;
1368 const char *system;
1369 const char *event;
1370 bool hist = false;
1371 char *trigger;
1372 char *number;
1373 bool enable;
1374 int ret;
1375
1376 if (!param)
1377 return -EINVAL;
1378
1379
1380 trigger = strsep(¶m, " \t");
1381 if (!trigger)
1382 return -EINVAL;
1383 if (param) {
1384 param = skip_spaces(param);
1385 if (!*param)
1386 param = NULL;
1387 }
1388
1389 system = strsep(&trigger, ":");
1390 if (!trigger)
1391 return -EINVAL;
1392
1393 event = strsep(&trigger, ":");
1394
1395 ret = -EINVAL;
1396 event_enable_file = find_event_file(tr, system, event);
1397 if (!event_enable_file)
1398 goto out;
1399
1400#ifdef CONFIG_HIST_TRIGGERS
1401 hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) ||
1402 (strcmp(cmd, DISABLE_HIST_STR) == 0));
1403
1404 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1405 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1406#else
1407 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1408#endif
1409 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
1410
1411 ret = -ENOMEM;
1412 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
1413 if (!trigger_data)
1414 goto out;
1415
1416 enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
1417 if (!enable_data) {
1418 kfree(trigger_data);
1419 goto out;
1420 }
1421
1422 trigger_data->count = -1;
1423 trigger_data->ops = trigger_ops;
1424 trigger_data->cmd_ops = cmd_ops;
1425 INIT_LIST_HEAD(&trigger_data->list);
1426 RCU_INIT_POINTER(trigger_data->filter, NULL);
1427
1428 enable_data->hist = hist;
1429 enable_data->enable = enable;
1430 enable_data->file = event_enable_file;
1431 trigger_data->private_data = enable_data;
1432
1433 if (glob[0] == '!') {
1434 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
1435 kfree(trigger_data);
1436 kfree(enable_data);
1437 ret = 0;
1438 goto out;
1439 }
1440
1441
1442 event_trigger_init(trigger_ops, trigger_data);
1443
1444 if (trigger) {
1445 number = strsep(&trigger, ":");
1446
1447 ret = -EINVAL;
1448 if (!strlen(number))
1449 goto out_free;
1450
1451
1452
1453
1454
1455 ret = kstrtoul(number, 0, &trigger_data->count);
1456 if (ret)
1457 goto out_free;
1458 }
1459
1460 if (!param)
1461 goto out_reg;
1462
1463 if (!cmd_ops->set_filter)
1464 goto out_reg;
1465
1466 ret = cmd_ops->set_filter(param, trigger_data, file);
1467 if (ret < 0)
1468 goto out_free;
1469
1470 out_reg:
1471
1472 ret = try_module_get(event_enable_file->event_call->mod);
1473 if (!ret) {
1474 ret = -EBUSY;
1475 goto out_free;
1476 }
1477
1478 ret = trace_event_enable_disable(event_enable_file, 1, 1);
1479 if (ret < 0)
1480 goto out_put;
1481 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1482
1483
1484
1485
1486
1487 if (!ret) {
1488 ret = -ENOENT;
1489 goto out_disable;
1490 } else if (ret < 0)
1491 goto out_disable;
1492
1493 ret = 0;
1494 event_trigger_free(trigger_ops, trigger_data);
1495 out:
1496 return ret;
1497
1498 out_disable:
1499 trace_event_enable_disable(event_enable_file, 0, 1);
1500 out_put:
1501 module_put(event_enable_file->event_call->mod);
1502 out_free:
1503 if (cmd_ops->set_filter)
1504 cmd_ops->set_filter(NULL, trigger_data, NULL);
1505 event_trigger_free(trigger_ops, trigger_data);
1506 kfree(enable_data);
1507 goto out;
1508}
1509
1510int event_enable_register_trigger(char *glob,
1511 struct event_trigger_ops *ops,
1512 struct event_trigger_data *data,
1513 struct trace_event_file *file)
1514{
1515 struct enable_trigger_data *enable_data = data->private_data;
1516 struct enable_trigger_data *test_enable_data;
1517 struct event_trigger_data *test;
1518 int ret = 0;
1519
1520 lockdep_assert_held(&event_mutex);
1521
1522 list_for_each_entry(test, &file->triggers, list) {
1523 test_enable_data = test->private_data;
1524 if (test_enable_data &&
1525 (test->cmd_ops->trigger_type ==
1526 data->cmd_ops->trigger_type) &&
1527 (test_enable_data->file == enable_data->file)) {
1528 ret = -EEXIST;
1529 goto out;
1530 }
1531 }
1532
1533 if (data->ops->init) {
1534 ret = data->ops->init(data->ops, data);
1535 if (ret < 0)
1536 goto out;
1537 }
1538
1539 list_add_rcu(&data->list, &file->triggers);
1540 ret++;
1541
1542 update_cond_flag(file);
1543 if (trace_event_trigger_enable_disable(file, 1) < 0) {
1544 list_del_rcu(&data->list);
1545 update_cond_flag(file);
1546 ret--;
1547 }
1548out:
1549 return ret;
1550}
1551
1552void event_enable_unregister_trigger(char *glob,
1553 struct event_trigger_ops *ops,
1554 struct event_trigger_data *test,
1555 struct trace_event_file *file)
1556{
1557 struct enable_trigger_data *test_enable_data = test->private_data;
1558 struct enable_trigger_data *enable_data;
1559 struct event_trigger_data *data;
1560 bool unregistered = false;
1561
1562 lockdep_assert_held(&event_mutex);
1563
1564 list_for_each_entry(data, &file->triggers, list) {
1565 enable_data = data->private_data;
1566 if (enable_data &&
1567 (data->cmd_ops->trigger_type ==
1568 test->cmd_ops->trigger_type) &&
1569 (enable_data->file == test_enable_data->file)) {
1570 unregistered = true;
1571 list_del_rcu(&data->list);
1572 trace_event_trigger_enable_disable(file, 0);
1573 update_cond_flag(file);
1574 break;
1575 }
1576 }
1577
1578 if (unregistered && data->ops->free)
1579 data->ops->free(data->ops, data);
1580}
1581
1582static struct event_trigger_ops *
1583event_enable_get_trigger_ops(char *cmd, char *param)
1584{
1585 struct event_trigger_ops *ops;
1586 bool enable;
1587
1588#ifdef CONFIG_HIST_TRIGGERS
1589 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1590 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1591#else
1592 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1593#endif
1594 if (enable)
1595 ops = param ? &event_enable_count_trigger_ops :
1596 &event_enable_trigger_ops;
1597 else
1598 ops = param ? &event_disable_count_trigger_ops :
1599 &event_disable_trigger_ops;
1600
1601 return ops;
1602}
1603
1604static struct event_command trigger_enable_cmd = {
1605 .name = ENABLE_EVENT_STR,
1606 .trigger_type = ETT_EVENT_ENABLE,
1607 .func = event_enable_trigger_func,
1608 .reg = event_enable_register_trigger,
1609 .unreg = event_enable_unregister_trigger,
1610 .get_trigger_ops = event_enable_get_trigger_ops,
1611 .set_filter = set_trigger_filter,
1612};
1613
1614static struct event_command trigger_disable_cmd = {
1615 .name = DISABLE_EVENT_STR,
1616 .trigger_type = ETT_EVENT_ENABLE,
1617 .func = event_enable_trigger_func,
1618 .reg = event_enable_register_trigger,
1619 .unreg = event_enable_unregister_trigger,
1620 .get_trigger_ops = event_enable_get_trigger_ops,
1621 .set_filter = set_trigger_filter,
1622};
1623
1624static __init void unregister_trigger_enable_disable_cmds(void)
1625{
1626 unregister_event_command(&trigger_enable_cmd);
1627 unregister_event_command(&trigger_disable_cmd);
1628}
1629
1630static __init int register_trigger_enable_disable_cmds(void)
1631{
1632 int ret;
1633
1634 ret = register_event_command(&trigger_enable_cmd);
1635 if (WARN_ON(ret < 0))
1636 return ret;
1637 ret = register_event_command(&trigger_disable_cmd);
1638 if (WARN_ON(ret < 0))
1639 unregister_trigger_enable_disable_cmds();
1640
1641 return ret;
1642}
1643
1644static __init int register_trigger_traceon_traceoff_cmds(void)
1645{
1646 int ret;
1647
1648 ret = register_event_command(&trigger_traceon_cmd);
1649 if (WARN_ON(ret < 0))
1650 return ret;
1651 ret = register_event_command(&trigger_traceoff_cmd);
1652 if (WARN_ON(ret < 0))
1653 unregister_trigger_traceon_traceoff_cmds();
1654
1655 return ret;
1656}
1657
1658__init int register_trigger_cmds(void)
1659{
1660 register_trigger_traceon_traceoff_cmds();
1661 register_trigger_snapshot_cmd();
1662 register_trigger_stacktrace_cmd();
1663 register_trigger_enable_disable_cmds();
1664 register_trigger_hist_enable_disable_cmds();
1665 register_trigger_hist_cmd();
1666
1667 return 0;
1668}
1669