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21#include <linux/module.h>
22#include <linux/ctype.h>
23#include <linux/mutex.h>
24#include <linux/slab.h>
25#include <linux/rculist.h>
26
27#include "trace.h"
28
29static LIST_HEAD(trigger_commands);
30static DEFINE_MUTEX(trigger_cmd_mutex);
31
32void trigger_data_free(struct event_trigger_data *data)
33{
34 if (data->cmd_ops->set_filter)
35 data->cmd_ops->set_filter(NULL, data, NULL);
36
37 synchronize_sched();
38 kfree(data);
39}
40
41
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44
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63
64
65enum event_trigger_type
66event_triggers_call(struct trace_event_file *file, void *rec)
67{
68 struct event_trigger_data *data;
69 enum event_trigger_type tt = ETT_NONE;
70 struct event_filter *filter;
71
72 if (list_empty(&file->triggers))
73 return tt;
74
75 list_for_each_entry_rcu(data, &file->triggers, list) {
76 if (data->paused)
77 continue;
78 if (!rec) {
79 data->ops->func(data, rec);
80 continue;
81 }
82 filter = rcu_dereference_sched(data->filter);
83 if (filter && !filter_match_preds(filter, rec))
84 continue;
85 if (event_command_post_trigger(data->cmd_ops)) {
86 tt |= data->cmd_ops->trigger_type;
87 continue;
88 }
89 data->ops->func(data, rec);
90 }
91 return tt;
92}
93EXPORT_SYMBOL_GPL(event_triggers_call);
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108void
109event_triggers_post_call(struct trace_event_file *file,
110 enum event_trigger_type tt,
111 void *rec)
112{
113 struct event_trigger_data *data;
114
115 list_for_each_entry_rcu(data, &file->triggers, list) {
116 if (data->paused)
117 continue;
118 if (data->cmd_ops->trigger_type & tt)
119 data->ops->func(data, rec);
120 }
121}
122EXPORT_SYMBOL_GPL(event_triggers_post_call);
123
124#define SHOW_AVAILABLE_TRIGGERS (void *)(1UL)
125
126static void *trigger_next(struct seq_file *m, void *t, loff_t *pos)
127{
128 struct trace_event_file *event_file = event_file_data(m->private);
129
130 if (t == SHOW_AVAILABLE_TRIGGERS)
131 return NULL;
132
133 return seq_list_next(t, &event_file->triggers, pos);
134}
135
136static void *trigger_start(struct seq_file *m, loff_t *pos)
137{
138 struct trace_event_file *event_file;
139
140
141 mutex_lock(&event_mutex);
142 event_file = event_file_data(m->private);
143 if (unlikely(!event_file))
144 return ERR_PTR(-ENODEV);
145
146 if (list_empty(&event_file->triggers))
147 return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL;
148
149 return seq_list_start(&event_file->triggers, *pos);
150}
151
152static void trigger_stop(struct seq_file *m, void *t)
153{
154 mutex_unlock(&event_mutex);
155}
156
157static int trigger_show(struct seq_file *m, void *v)
158{
159 struct event_trigger_data *data;
160 struct event_command *p;
161
162 if (v == SHOW_AVAILABLE_TRIGGERS) {
163 seq_puts(m, "# Available triggers:\n");
164 seq_putc(m, '#');
165 mutex_lock(&trigger_cmd_mutex);
166 list_for_each_entry_reverse(p, &trigger_commands, list)
167 seq_printf(m, " %s", p->name);
168 seq_putc(m, '\n');
169 mutex_unlock(&trigger_cmd_mutex);
170 return 0;
171 }
172
173 data = list_entry(v, struct event_trigger_data, list);
174 data->ops->print(m, data->ops, data);
175
176 return 0;
177}
178
179static const struct seq_operations event_triggers_seq_ops = {
180 .start = trigger_start,
181 .next = trigger_next,
182 .stop = trigger_stop,
183 .show = trigger_show,
184};
185
186static int event_trigger_regex_open(struct inode *inode, struct file *file)
187{
188 int ret = 0;
189
190 mutex_lock(&event_mutex);
191
192 if (unlikely(!event_file_data(file))) {
193 mutex_unlock(&event_mutex);
194 return -ENODEV;
195 }
196
197 if ((file->f_mode & FMODE_WRITE) &&
198 (file->f_flags & O_TRUNC)) {
199 struct trace_event_file *event_file;
200 struct event_command *p;
201
202 event_file = event_file_data(file);
203
204 list_for_each_entry(p, &trigger_commands, list) {
205 if (p->unreg_all)
206 p->unreg_all(event_file);
207 }
208 }
209
210 if (file->f_mode & FMODE_READ) {
211 ret = seq_open(file, &event_triggers_seq_ops);
212 if (!ret) {
213 struct seq_file *m = file->private_data;
214 m->private = file;
215 }
216 }
217
218 mutex_unlock(&event_mutex);
219
220 return ret;
221}
222
223static int trigger_process_regex(struct trace_event_file *file, char *buff)
224{
225 char *command, *next = buff;
226 struct event_command *p;
227 int ret = -EINVAL;
228
229 command = strsep(&next, ": \t");
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 return event_trigger_regex_open(inode, filp);
308}
309
310static int
311event_trigger_release(struct inode *inode, struct file *file)
312{
313 return event_trigger_regex_release(inode, file);
314}
315
316const struct file_operations event_trigger_fops = {
317 .open = event_trigger_open,
318 .read = seq_read,
319 .write = event_trigger_write,
320 .llseek = tracing_lseek,
321 .release = event_trigger_release,
322};
323
324
325
326
327
328__init int register_event_command(struct event_command *cmd)
329{
330 struct event_command *p;
331 int ret = 0;
332
333 mutex_lock(&trigger_cmd_mutex);
334 list_for_each_entry(p, &trigger_commands, list) {
335 if (strcmp(cmd->name, p->name) == 0) {
336 ret = -EBUSY;
337 goto out_unlock;
338 }
339 }
340 list_add(&cmd->list, &trigger_commands);
341 out_unlock:
342 mutex_unlock(&trigger_cmd_mutex);
343
344 return ret;
345}
346
347
348
349
350
351__init int unregister_event_command(struct event_command *cmd)
352{
353 struct event_command *p, *n;
354 int ret = -ENODEV;
355
356 mutex_lock(&trigger_cmd_mutex);
357 list_for_each_entry_safe(p, n, &trigger_commands, list) {
358 if (strcmp(cmd->name, p->name) == 0) {
359 ret = 0;
360 list_del_init(&p->list);
361 goto out_unlock;
362 }
363 }
364 out_unlock:
365 mutex_unlock(&trigger_cmd_mutex);
366
367 return ret;
368}
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384static int
385event_trigger_print(const char *name, struct seq_file *m,
386 void *data, char *filter_str)
387{
388 long count = (long)data;
389
390 seq_puts(m, name);
391
392 if (count == -1)
393 seq_puts(m, ":unlimited");
394 else
395 seq_printf(m, ":count=%ld", count);
396
397 if (filter_str)
398 seq_printf(m, " if %s\n", filter_str);
399 else
400 seq_putc(m, '\n');
401
402 return 0;
403}
404
405
406
407
408
409
410
411
412
413
414
415
416
417int event_trigger_init(struct event_trigger_ops *ops,
418 struct event_trigger_data *data)
419{
420 data->ref++;
421 return 0;
422}
423
424
425
426
427
428
429
430
431
432
433
434static void
435event_trigger_free(struct event_trigger_ops *ops,
436 struct event_trigger_data *data)
437{
438 if (WARN_ON_ONCE(data->ref <= 0))
439 return;
440
441 data->ref--;
442 if (!data->ref)
443 trigger_data_free(data);
444}
445
446int trace_event_trigger_enable_disable(struct trace_event_file *file,
447 int trigger_enable)
448{
449 int ret = 0;
450
451 if (trigger_enable) {
452 if (atomic_inc_return(&file->tm_ref) > 1)
453 return ret;
454 set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
455 ret = trace_event_enable_disable(file, 1, 1);
456 } else {
457 if (atomic_dec_return(&file->tm_ref) > 0)
458 return ret;
459 clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
460 ret = trace_event_enable_disable(file, 0, 1);
461 }
462
463 return ret;
464}
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479void
480clear_event_triggers(struct trace_array *tr)
481{
482 struct trace_event_file *file;
483
484 list_for_each_entry(file, &tr->events, list) {
485 struct event_trigger_data *data;
486 list_for_each_entry_rcu(data, &file->triggers, list) {
487 trace_event_trigger_enable_disable(file, 0);
488 if (data->ops->free)
489 data->ops->free(data->ops, data);
490 }
491 }
492}
493
494
495
496
497
498
499
500
501
502
503
504void update_cond_flag(struct trace_event_file *file)
505{
506 struct event_trigger_data *data;
507 bool set_cond = false;
508
509 list_for_each_entry_rcu(data, &file->triggers, list) {
510 if (data->filter || event_command_post_trigger(data->cmd_ops) ||
511 event_command_needs_rec(data->cmd_ops)) {
512 set_cond = true;
513 break;
514 }
515 }
516
517 if (set_cond)
518 set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
519 else
520 clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
521}
522
523
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530
531
532
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534
535
536
537static int register_trigger(char *glob, struct event_trigger_ops *ops,
538 struct event_trigger_data *data,
539 struct trace_event_file *file)
540{
541 struct event_trigger_data *test;
542 int ret = 0;
543
544 list_for_each_entry_rcu(test, &file->triggers, list) {
545 if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) {
546 ret = -EEXIST;
547 goto out;
548 }
549 }
550
551 if (data->ops->init) {
552 ret = data->ops->init(data->ops, data);
553 if (ret < 0)
554 goto out;
555 }
556
557 list_add_rcu(&data->list, &file->triggers);
558 ret++;
559
560 update_cond_flag(file);
561 if (trace_event_trigger_enable_disable(file, 1) < 0) {
562 list_del_rcu(&data->list);
563 update_cond_flag(file);
564 ret--;
565 }
566out:
567 return ret;
568}
569
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579
580
581
582void unregister_trigger(char *glob, struct event_trigger_ops *ops,
583 struct event_trigger_data *test,
584 struct trace_event_file *file)
585{
586 struct event_trigger_data *data;
587 bool unregistered = false;
588
589 list_for_each_entry_rcu(data, &file->triggers, list) {
590 if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
591 unregistered = true;
592 list_del_rcu(&data->list);
593 trace_event_trigger_enable_disable(file, 0);
594 update_cond_flag(file);
595 break;
596 }
597 }
598
599 if (unregistered && data->ops->free)
600 data->ops->free(data->ops, data);
601}
602
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616
617
618
619static int
620event_trigger_callback(struct event_command *cmd_ops,
621 struct trace_event_file *file,
622 char *glob, char *cmd, char *param)
623{
624 struct event_trigger_data *trigger_data;
625 struct event_trigger_ops *trigger_ops;
626 char *trigger = NULL;
627 char *number;
628 int ret;
629
630
631 if (param && isdigit(param[0]))
632 trigger = strsep(¶m, " \t");
633
634 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
635
636 ret = -ENOMEM;
637 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
638 if (!trigger_data)
639 goto out;
640
641 trigger_data->count = -1;
642 trigger_data->ops = trigger_ops;
643 trigger_data->cmd_ops = cmd_ops;
644 INIT_LIST_HEAD(&trigger_data->list);
645 INIT_LIST_HEAD(&trigger_data->named_list);
646
647 if (glob[0] == '!') {
648 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
649 kfree(trigger_data);
650 ret = 0;
651 goto out;
652 }
653
654 if (trigger) {
655 number = strsep(&trigger, ":");
656
657 ret = -EINVAL;
658 if (!strlen(number))
659 goto out_free;
660
661
662
663
664
665 ret = kstrtoul(number, 0, &trigger_data->count);
666 if (ret)
667 goto out_free;
668 }
669
670 if (!param)
671 goto out_reg;
672
673 if (!cmd_ops->set_filter)
674 goto out_reg;
675
676 ret = cmd_ops->set_filter(param, trigger_data, file);
677 if (ret < 0)
678 goto out_free;
679
680 out_reg:
681 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
682
683
684
685
686
687 if (!ret) {
688 ret = -ENOENT;
689 goto out_free;
690 } else if (ret < 0)
691 goto out_free;
692 ret = 0;
693 out:
694 return ret;
695
696 out_free:
697 if (cmd_ops->set_filter)
698 cmd_ops->set_filter(NULL, trigger_data, NULL);
699 kfree(trigger_data);
700 goto out;
701}
702
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715
716
717
718
719int set_trigger_filter(char *filter_str,
720 struct event_trigger_data *trigger_data,
721 struct trace_event_file *file)
722{
723 struct event_trigger_data *data = trigger_data;
724 struct event_filter *filter = NULL, *tmp;
725 int ret = -EINVAL;
726 char *s;
727
728 if (!filter_str)
729 goto assign;
730
731 s = strsep(&filter_str, " \t");
732
733 if (!strlen(s) || strcmp(s, "if") != 0)
734 goto out;
735
736 if (!filter_str)
737 goto out;
738
739
740 ret = create_event_filter(file->event_call, filter_str, false, &filter);
741 if (ret)
742 goto out;
743 assign:
744 tmp = rcu_access_pointer(data->filter);
745
746 rcu_assign_pointer(data->filter, filter);
747
748 if (tmp) {
749
750 synchronize_sched();
751 free_event_filter(tmp);
752 }
753
754 kfree(data->filter_str);
755 data->filter_str = NULL;
756
757 if (filter_str) {
758 data->filter_str = kstrdup(filter_str, GFP_KERNEL);
759 if (!data->filter_str) {
760 free_event_filter(rcu_access_pointer(data->filter));
761 data->filter = NULL;
762 ret = -ENOMEM;
763 }
764 }
765 out:
766 return ret;
767}
768
769static LIST_HEAD(named_triggers);
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785struct event_trigger_data *find_named_trigger(const char *name)
786{
787 struct event_trigger_data *data;
788
789 if (!name)
790 return NULL;
791
792 list_for_each_entry(data, &named_triggers, named_list) {
793 if (data->named_data)
794 continue;
795 if (strcmp(data->name, name) == 0)
796 return data;
797 }
798
799 return NULL;
800}
801
802
803
804
805
806
807
808bool is_named_trigger(struct event_trigger_data *test)
809{
810 struct event_trigger_data *data;
811
812 list_for_each_entry(data, &named_triggers, named_list) {
813 if (test == data)
814 return true;
815 }
816
817 return false;
818}
819
820
821
822
823
824
825
826
827int save_named_trigger(const char *name, struct event_trigger_data *data)
828{
829 data->name = kstrdup(name, GFP_KERNEL);
830 if (!data->name)
831 return -ENOMEM;
832
833 list_add(&data->named_list, &named_triggers);
834
835 return 0;
836}
837
838
839
840
841
842void del_named_trigger(struct event_trigger_data *data)
843{
844 kfree(data->name);
845 data->name = NULL;
846
847 list_del(&data->named_list);
848}
849
850static void __pause_named_trigger(struct event_trigger_data *data, bool pause)
851{
852 struct event_trigger_data *test;
853
854 list_for_each_entry(test, &named_triggers, named_list) {
855 if (strcmp(test->name, data->name) == 0) {
856 if (pause) {
857 test->paused_tmp = test->paused;
858 test->paused = true;
859 } else {
860 test->paused = test->paused_tmp;
861 }
862 }
863 }
864}
865
866
867
868
869
870
871
872
873
874
875void pause_named_trigger(struct event_trigger_data *data)
876{
877 __pause_named_trigger(data, true);
878}
879
880
881
882
883
884
885
886
887
888
889void unpause_named_trigger(struct event_trigger_data *data)
890{
891 __pause_named_trigger(data, false);
892}
893
894
895
896
897
898
899
900
901
902
903
904
905void set_named_trigger_data(struct event_trigger_data *data,
906 struct event_trigger_data *named_data)
907{
908 data->named_data = named_data;
909}
910
911static void
912traceon_trigger(struct event_trigger_data *data, void *rec)
913{
914 if (tracing_is_on())
915 return;
916
917 tracing_on();
918}
919
920static void
921traceon_count_trigger(struct event_trigger_data *data, void *rec)
922{
923 if (tracing_is_on())
924 return;
925
926 if (!data->count)
927 return;
928
929 if (data->count != -1)
930 (data->count)--;
931
932 tracing_on();
933}
934
935static void
936traceoff_trigger(struct event_trigger_data *data, void *rec)
937{
938 if (!tracing_is_on())
939 return;
940
941 tracing_off();
942}
943
944static void
945traceoff_count_trigger(struct event_trigger_data *data, void *rec)
946{
947 if (!tracing_is_on())
948 return;
949
950 if (!data->count)
951 return;
952
953 if (data->count != -1)
954 (data->count)--;
955
956 tracing_off();
957}
958
959static int
960traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
961 struct event_trigger_data *data)
962{
963 return event_trigger_print("traceon", m, (void *)data->count,
964 data->filter_str);
965}
966
967static int
968traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
969 struct event_trigger_data *data)
970{
971 return event_trigger_print("traceoff", m, (void *)data->count,
972 data->filter_str);
973}
974
975static struct event_trigger_ops traceon_trigger_ops = {
976 .func = traceon_trigger,
977 .print = traceon_trigger_print,
978 .init = event_trigger_init,
979 .free = event_trigger_free,
980};
981
982static struct event_trigger_ops traceon_count_trigger_ops = {
983 .func = traceon_count_trigger,
984 .print = traceon_trigger_print,
985 .init = event_trigger_init,
986 .free = event_trigger_free,
987};
988
989static struct event_trigger_ops traceoff_trigger_ops = {
990 .func = traceoff_trigger,
991 .print = traceoff_trigger_print,
992 .init = event_trigger_init,
993 .free = event_trigger_free,
994};
995
996static struct event_trigger_ops traceoff_count_trigger_ops = {
997 .func = traceoff_count_trigger,
998 .print = traceoff_trigger_print,
999 .init = event_trigger_init,
1000 .free = event_trigger_free,
1001};
1002
1003static struct event_trigger_ops *
1004onoff_get_trigger_ops(char *cmd, char *param)
1005{
1006 struct event_trigger_ops *ops;
1007
1008
1009 if (strcmp(cmd, "traceon") == 0)
1010 ops = param ? &traceon_count_trigger_ops :
1011 &traceon_trigger_ops;
1012 else
1013 ops = param ? &traceoff_count_trigger_ops :
1014 &traceoff_trigger_ops;
1015
1016 return ops;
1017}
1018
1019static struct event_command trigger_traceon_cmd = {
1020 .name = "traceon",
1021 .trigger_type = ETT_TRACE_ONOFF,
1022 .func = event_trigger_callback,
1023 .reg = register_trigger,
1024 .unreg = unregister_trigger,
1025 .get_trigger_ops = onoff_get_trigger_ops,
1026 .set_filter = set_trigger_filter,
1027};
1028
1029static struct event_command trigger_traceoff_cmd = {
1030 .name = "traceoff",
1031 .trigger_type = ETT_TRACE_ONOFF,
1032 .flags = EVENT_CMD_FL_POST_TRIGGER,
1033 .func = event_trigger_callback,
1034 .reg = register_trigger,
1035 .unreg = unregister_trigger,
1036 .get_trigger_ops = onoff_get_trigger_ops,
1037 .set_filter = set_trigger_filter,
1038};
1039
1040#ifdef CONFIG_TRACER_SNAPSHOT
1041static void
1042snapshot_trigger(struct event_trigger_data *data, void *rec)
1043{
1044 tracing_snapshot();
1045}
1046
1047static void
1048snapshot_count_trigger(struct event_trigger_data *data, void *rec)
1049{
1050 if (!data->count)
1051 return;
1052
1053 if (data->count != -1)
1054 (data->count)--;
1055
1056 snapshot_trigger(data, rec);
1057}
1058
1059static int
1060register_snapshot_trigger(char *glob, struct event_trigger_ops *ops,
1061 struct event_trigger_data *data,
1062 struct trace_event_file *file)
1063{
1064 int ret = register_trigger(glob, ops, data, file);
1065
1066 if (ret > 0 && tracing_alloc_snapshot() != 0) {
1067 unregister_trigger(glob, ops, data, file);
1068 ret = 0;
1069 }
1070
1071 return ret;
1072}
1073
1074static int
1075snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1076 struct event_trigger_data *data)
1077{
1078 return event_trigger_print("snapshot", m, (void *)data->count,
1079 data->filter_str);
1080}
1081
1082static struct event_trigger_ops snapshot_trigger_ops = {
1083 .func = snapshot_trigger,
1084 .print = snapshot_trigger_print,
1085 .init = event_trigger_init,
1086 .free = event_trigger_free,
1087};
1088
1089static struct event_trigger_ops snapshot_count_trigger_ops = {
1090 .func = snapshot_count_trigger,
1091 .print = snapshot_trigger_print,
1092 .init = event_trigger_init,
1093 .free = event_trigger_free,
1094};
1095
1096static struct event_trigger_ops *
1097snapshot_get_trigger_ops(char *cmd, char *param)
1098{
1099 return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
1100}
1101
1102static struct event_command trigger_snapshot_cmd = {
1103 .name = "snapshot",
1104 .trigger_type = ETT_SNAPSHOT,
1105 .func = event_trigger_callback,
1106 .reg = register_snapshot_trigger,
1107 .unreg = unregister_trigger,
1108 .get_trigger_ops = snapshot_get_trigger_ops,
1109 .set_filter = set_trigger_filter,
1110};
1111
1112static __init int register_trigger_snapshot_cmd(void)
1113{
1114 int ret;
1115
1116 ret = register_event_command(&trigger_snapshot_cmd);
1117 WARN_ON(ret < 0);
1118
1119 return ret;
1120}
1121#else
1122static __init int register_trigger_snapshot_cmd(void) { return 0; }
1123#endif
1124
1125#ifdef CONFIG_STACKTRACE
1126
1127
1128
1129
1130
1131
1132#define STACK_SKIP 3
1133
1134static void
1135stacktrace_trigger(struct event_trigger_data *data, void *rec)
1136{
1137 trace_dump_stack(STACK_SKIP);
1138}
1139
1140static void
1141stacktrace_count_trigger(struct event_trigger_data *data, void *rec)
1142{
1143 if (!data->count)
1144 return;
1145
1146 if (data->count != -1)
1147 (data->count)--;
1148
1149 stacktrace_trigger(data, rec);
1150}
1151
1152static int
1153stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
1154 struct event_trigger_data *data)
1155{
1156 return event_trigger_print("stacktrace", m, (void *)data->count,
1157 data->filter_str);
1158}
1159
1160static struct event_trigger_ops stacktrace_trigger_ops = {
1161 .func = stacktrace_trigger,
1162 .print = stacktrace_trigger_print,
1163 .init = event_trigger_init,
1164 .free = event_trigger_free,
1165};
1166
1167static struct event_trigger_ops stacktrace_count_trigger_ops = {
1168 .func = stacktrace_count_trigger,
1169 .print = stacktrace_trigger_print,
1170 .init = event_trigger_init,
1171 .free = event_trigger_free,
1172};
1173
1174static struct event_trigger_ops *
1175stacktrace_get_trigger_ops(char *cmd, char *param)
1176{
1177 return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
1178}
1179
1180static struct event_command trigger_stacktrace_cmd = {
1181 .name = "stacktrace",
1182 .trigger_type = ETT_STACKTRACE,
1183 .flags = EVENT_CMD_FL_POST_TRIGGER,
1184 .func = event_trigger_callback,
1185 .reg = register_trigger,
1186 .unreg = unregister_trigger,
1187 .get_trigger_ops = stacktrace_get_trigger_ops,
1188 .set_filter = set_trigger_filter,
1189};
1190
1191static __init int register_trigger_stacktrace_cmd(void)
1192{
1193 int ret;
1194
1195 ret = register_event_command(&trigger_stacktrace_cmd);
1196 WARN_ON(ret < 0);
1197
1198 return ret;
1199}
1200#else
1201static __init int register_trigger_stacktrace_cmd(void) { return 0; }
1202#endif
1203
1204static __init void unregister_trigger_traceon_traceoff_cmds(void)
1205{
1206 unregister_event_command(&trigger_traceon_cmd);
1207 unregister_event_command(&trigger_traceoff_cmd);
1208}
1209
1210static void
1211event_enable_trigger(struct event_trigger_data *data, void *rec)
1212{
1213 struct enable_trigger_data *enable_data = data->private_data;
1214
1215 if (enable_data->enable)
1216 clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1217 else
1218 set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
1219}
1220
1221static void
1222event_enable_count_trigger(struct event_trigger_data *data, void *rec)
1223{
1224 struct enable_trigger_data *enable_data = data->private_data;
1225
1226 if (!data->count)
1227 return;
1228
1229
1230 if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
1231 return;
1232
1233 if (data->count != -1)
1234 (data->count)--;
1235
1236 event_enable_trigger(data, rec);
1237}
1238
1239int event_enable_trigger_print(struct seq_file *m,
1240 struct event_trigger_ops *ops,
1241 struct event_trigger_data *data)
1242{
1243 struct enable_trigger_data *enable_data = data->private_data;
1244
1245 seq_printf(m, "%s:%s:%s",
1246 enable_data->hist ?
1247 (enable_data->enable ? ENABLE_HIST_STR : DISABLE_HIST_STR) :
1248 (enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR),
1249 enable_data->file->event_call->class->system,
1250 trace_event_name(enable_data->file->event_call));
1251
1252 if (data->count == -1)
1253 seq_puts(m, ":unlimited");
1254 else
1255 seq_printf(m, ":count=%ld", data->count);
1256
1257 if (data->filter_str)
1258 seq_printf(m, " if %s\n", data->filter_str);
1259 else
1260 seq_putc(m, '\n');
1261
1262 return 0;
1263}
1264
1265void event_enable_trigger_free(struct event_trigger_ops *ops,
1266 struct event_trigger_data *data)
1267{
1268 struct enable_trigger_data *enable_data = data->private_data;
1269
1270 if (WARN_ON_ONCE(data->ref <= 0))
1271 return;
1272
1273 data->ref--;
1274 if (!data->ref) {
1275
1276 trace_event_enable_disable(enable_data->file, 0, 1);
1277 module_put(enable_data->file->event_call->mod);
1278 trigger_data_free(data);
1279 kfree(enable_data);
1280 }
1281}
1282
1283static struct event_trigger_ops event_enable_trigger_ops = {
1284 .func = event_enable_trigger,
1285 .print = event_enable_trigger_print,
1286 .init = event_trigger_init,
1287 .free = event_enable_trigger_free,
1288};
1289
1290static struct event_trigger_ops event_enable_count_trigger_ops = {
1291 .func = event_enable_count_trigger,
1292 .print = event_enable_trigger_print,
1293 .init = event_trigger_init,
1294 .free = event_enable_trigger_free,
1295};
1296
1297static struct event_trigger_ops event_disable_trigger_ops = {
1298 .func = event_enable_trigger,
1299 .print = event_enable_trigger_print,
1300 .init = event_trigger_init,
1301 .free = event_enable_trigger_free,
1302};
1303
1304static struct event_trigger_ops event_disable_count_trigger_ops = {
1305 .func = event_enable_count_trigger,
1306 .print = event_enable_trigger_print,
1307 .init = event_trigger_init,
1308 .free = event_enable_trigger_free,
1309};
1310
1311int event_enable_trigger_func(struct event_command *cmd_ops,
1312 struct trace_event_file *file,
1313 char *glob, char *cmd, char *param)
1314{
1315 struct trace_event_file *event_enable_file;
1316 struct enable_trigger_data *enable_data;
1317 struct event_trigger_data *trigger_data;
1318 struct event_trigger_ops *trigger_ops;
1319 struct trace_array *tr = file->tr;
1320 const char *system;
1321 const char *event;
1322 bool hist = false;
1323 char *trigger;
1324 char *number;
1325 bool enable;
1326 int ret;
1327
1328 if (!param)
1329 return -EINVAL;
1330
1331
1332 trigger = strsep(¶m, " \t");
1333 if (!trigger)
1334 return -EINVAL;
1335
1336 system = strsep(&trigger, ":");
1337 if (!trigger)
1338 return -EINVAL;
1339
1340 event = strsep(&trigger, ":");
1341
1342 ret = -EINVAL;
1343 event_enable_file = find_event_file(tr, system, event);
1344 if (!event_enable_file)
1345 goto out;
1346
1347#ifdef CONFIG_HIST_TRIGGERS
1348 hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) ||
1349 (strcmp(cmd, DISABLE_HIST_STR) == 0));
1350
1351 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1352 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1353#else
1354 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1355#endif
1356 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
1357
1358 ret = -ENOMEM;
1359 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
1360 if (!trigger_data)
1361 goto out;
1362
1363 enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
1364 if (!enable_data) {
1365 kfree(trigger_data);
1366 goto out;
1367 }
1368
1369 trigger_data->count = -1;
1370 trigger_data->ops = trigger_ops;
1371 trigger_data->cmd_ops = cmd_ops;
1372 INIT_LIST_HEAD(&trigger_data->list);
1373 RCU_INIT_POINTER(trigger_data->filter, NULL);
1374
1375 enable_data->hist = hist;
1376 enable_data->enable = enable;
1377 enable_data->file = event_enable_file;
1378 trigger_data->private_data = enable_data;
1379
1380 if (glob[0] == '!') {
1381 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
1382 kfree(trigger_data);
1383 kfree(enable_data);
1384 ret = 0;
1385 goto out;
1386 }
1387
1388 if (trigger) {
1389 number = strsep(&trigger, ":");
1390
1391 ret = -EINVAL;
1392 if (!strlen(number))
1393 goto out_free;
1394
1395
1396
1397
1398
1399 ret = kstrtoul(number, 0, &trigger_data->count);
1400 if (ret)
1401 goto out_free;
1402 }
1403
1404 if (!param)
1405 goto out_reg;
1406
1407 if (!cmd_ops->set_filter)
1408 goto out_reg;
1409
1410 ret = cmd_ops->set_filter(param, trigger_data, file);
1411 if (ret < 0)
1412 goto out_free;
1413
1414 out_reg:
1415
1416 ret = try_module_get(event_enable_file->event_call->mod);
1417 if (!ret) {
1418 ret = -EBUSY;
1419 goto out_free;
1420 }
1421
1422 ret = trace_event_enable_disable(event_enable_file, 1, 1);
1423 if (ret < 0)
1424 goto out_put;
1425 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1426
1427
1428
1429
1430
1431 if (!ret) {
1432 ret = -ENOENT;
1433 goto out_disable;
1434 } else if (ret < 0)
1435 goto out_disable;
1436
1437 ret = 0;
1438 out:
1439 return ret;
1440
1441 out_disable:
1442 trace_event_enable_disable(event_enable_file, 0, 1);
1443 out_put:
1444 module_put(event_enable_file->event_call->mod);
1445 out_free:
1446 if (cmd_ops->set_filter)
1447 cmd_ops->set_filter(NULL, trigger_data, NULL);
1448 kfree(trigger_data);
1449 kfree(enable_data);
1450 goto out;
1451}
1452
1453int event_enable_register_trigger(char *glob,
1454 struct event_trigger_ops *ops,
1455 struct event_trigger_data *data,
1456 struct trace_event_file *file)
1457{
1458 struct enable_trigger_data *enable_data = data->private_data;
1459 struct enable_trigger_data *test_enable_data;
1460 struct event_trigger_data *test;
1461 int ret = 0;
1462
1463 list_for_each_entry_rcu(test, &file->triggers, list) {
1464 test_enable_data = test->private_data;
1465 if (test_enable_data &&
1466 (test->cmd_ops->trigger_type ==
1467 data->cmd_ops->trigger_type) &&
1468 (test_enable_data->file == enable_data->file)) {
1469 ret = -EEXIST;
1470 goto out;
1471 }
1472 }
1473
1474 if (data->ops->init) {
1475 ret = data->ops->init(data->ops, data);
1476 if (ret < 0)
1477 goto out;
1478 }
1479
1480 list_add_rcu(&data->list, &file->triggers);
1481 ret++;
1482
1483 update_cond_flag(file);
1484 if (trace_event_trigger_enable_disable(file, 1) < 0) {
1485 list_del_rcu(&data->list);
1486 update_cond_flag(file);
1487 ret--;
1488 }
1489out:
1490 return ret;
1491}
1492
1493void event_enable_unregister_trigger(char *glob,
1494 struct event_trigger_ops *ops,
1495 struct event_trigger_data *test,
1496 struct trace_event_file *file)
1497{
1498 struct enable_trigger_data *test_enable_data = test->private_data;
1499 struct enable_trigger_data *enable_data;
1500 struct event_trigger_data *data;
1501 bool unregistered = false;
1502
1503 list_for_each_entry_rcu(data, &file->triggers, list) {
1504 enable_data = data->private_data;
1505 if (enable_data &&
1506 (data->cmd_ops->trigger_type ==
1507 test->cmd_ops->trigger_type) &&
1508 (enable_data->file == test_enable_data->file)) {
1509 unregistered = true;
1510 list_del_rcu(&data->list);
1511 trace_event_trigger_enable_disable(file, 0);
1512 update_cond_flag(file);
1513 break;
1514 }
1515 }
1516
1517 if (unregistered && data->ops->free)
1518 data->ops->free(data->ops, data);
1519}
1520
1521static struct event_trigger_ops *
1522event_enable_get_trigger_ops(char *cmd, char *param)
1523{
1524 struct event_trigger_ops *ops;
1525 bool enable;
1526
1527#ifdef CONFIG_HIST_TRIGGERS
1528 enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
1529 (strcmp(cmd, ENABLE_HIST_STR) == 0));
1530#else
1531 enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
1532#endif
1533 if (enable)
1534 ops = param ? &event_enable_count_trigger_ops :
1535 &event_enable_trigger_ops;
1536 else
1537 ops = param ? &event_disable_count_trigger_ops :
1538 &event_disable_trigger_ops;
1539
1540 return ops;
1541}
1542
1543static struct event_command trigger_enable_cmd = {
1544 .name = ENABLE_EVENT_STR,
1545 .trigger_type = ETT_EVENT_ENABLE,
1546 .func = event_enable_trigger_func,
1547 .reg = event_enable_register_trigger,
1548 .unreg = event_enable_unregister_trigger,
1549 .get_trigger_ops = event_enable_get_trigger_ops,
1550 .set_filter = set_trigger_filter,
1551};
1552
1553static struct event_command trigger_disable_cmd = {
1554 .name = DISABLE_EVENT_STR,
1555 .trigger_type = ETT_EVENT_ENABLE,
1556 .func = event_enable_trigger_func,
1557 .reg = event_enable_register_trigger,
1558 .unreg = event_enable_unregister_trigger,
1559 .get_trigger_ops = event_enable_get_trigger_ops,
1560 .set_filter = set_trigger_filter,
1561};
1562
1563static __init void unregister_trigger_enable_disable_cmds(void)
1564{
1565 unregister_event_command(&trigger_enable_cmd);
1566 unregister_event_command(&trigger_disable_cmd);
1567}
1568
1569static __init int register_trigger_enable_disable_cmds(void)
1570{
1571 int ret;
1572
1573 ret = register_event_command(&trigger_enable_cmd);
1574 if (WARN_ON(ret < 0))
1575 return ret;
1576 ret = register_event_command(&trigger_disable_cmd);
1577 if (WARN_ON(ret < 0))
1578 unregister_trigger_enable_disable_cmds();
1579
1580 return ret;
1581}
1582
1583static __init int register_trigger_traceon_traceoff_cmds(void)
1584{
1585 int ret;
1586
1587 ret = register_event_command(&trigger_traceon_cmd);
1588 if (WARN_ON(ret < 0))
1589 return ret;
1590 ret = register_event_command(&trigger_traceoff_cmd);
1591 if (WARN_ON(ret < 0))
1592 unregister_trigger_traceon_traceoff_cmds();
1593
1594 return ret;
1595}
1596
1597__init int register_trigger_cmds(void)
1598{
1599 register_trigger_traceon_traceoff_cmds();
1600 register_trigger_snapshot_cmd();
1601 register_trigger_stacktrace_cmd();
1602 register_trigger_enable_disable_cmds();
1603 register_trigger_hist_enable_disable_cmds();
1604 register_trigger_hist_cmd();
1605
1606 return 0;
1607}
1608