]>
Commit | Line | Data |
---|---|---|
85f2b082 TZ |
1 | /* |
2 | * trace_events_trigger - trace event triggers | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | * | |
18 | * Copyright (C) 2013 Tom Zanussi <tom.zanussi@linux.intel.com> | |
19 | */ | |
20 | ||
21 | #include <linux/module.h> | |
22 | #include <linux/ctype.h> | |
23 | #include <linux/mutex.h> | |
24 | #include <linux/slab.h> | |
25 | ||
26 | #include "trace.h" | |
27 | ||
28 | static LIST_HEAD(trigger_commands); | |
29 | static DEFINE_MUTEX(trigger_cmd_mutex); | |
30 | ||
2a2df321 TZ |
31 | static void |
32 | trigger_data_free(struct event_trigger_data *data) | |
33 | { | |
bac5fb97 TZ |
34 | if (data->cmd_ops->set_filter) |
35 | data->cmd_ops->set_filter(NULL, data, NULL); | |
36 | ||
2a2df321 TZ |
37 | synchronize_sched(); /* make sure current triggers exit before free */ |
38 | kfree(data); | |
39 | } | |
40 | ||
85f2b082 TZ |
41 | /** |
42 | * event_triggers_call - Call triggers associated with a trace event | |
7f1d2f82 | 43 | * @file: The trace_event_file associated with the event |
bac5fb97 | 44 | * @rec: The trace entry for the event, NULL for unconditional invocation |
85f2b082 TZ |
45 | * |
46 | * For each trigger associated with an event, invoke the trigger | |
bac5fb97 TZ |
47 | * function registered with the associated trigger command. If rec is |
48 | * non-NULL, it means that the trigger requires further processing and | |
49 | * shouldn't be unconditionally invoked. If rec is non-NULL and the | |
50 | * trigger has a filter associated with it, rec will checked against | |
51 | * the filter and if the record matches the trigger will be invoked. | |
52 | * If the trigger is a 'post_trigger', meaning it shouldn't be invoked | |
53 | * in any case until the current event is written, the trigger | |
54 | * function isn't invoked but the bit associated with the deferred | |
55 | * trigger is set in the return value. | |
56 | * | |
57 | * Returns an enum event_trigger_type value containing a set bit for | |
58 | * any trigger that should be deferred, ETT_NONE if nothing to defer. | |
85f2b082 TZ |
59 | * |
60 | * Called from tracepoint handlers (with rcu_read_lock_sched() held). | |
61 | * | |
62 | * Return: an enum event_trigger_type value containing a set bit for | |
63 | * any trigger that should be deferred, ETT_NONE if nothing to defer. | |
64 | */ | |
bac5fb97 | 65 | enum event_trigger_type |
7f1d2f82 | 66 | event_triggers_call(struct trace_event_file *file, void *rec) |
85f2b082 TZ |
67 | { |
68 | struct event_trigger_data *data; | |
bac5fb97 | 69 | enum event_trigger_type tt = ETT_NONE; |
d8a30f20 | 70 | struct event_filter *filter; |
85f2b082 TZ |
71 | |
72 | if (list_empty(&file->triggers)) | |
bac5fb97 | 73 | return tt; |
85f2b082 | 74 | |
bac5fb97 TZ |
75 | list_for_each_entry_rcu(data, &file->triggers, list) { |
76 | if (!rec) { | |
77 | data->ops->func(data); | |
78 | continue; | |
79 | } | |
561a4fe8 | 80 | filter = rcu_dereference_sched(data->filter); |
d8a30f20 | 81 | if (filter && !filter_match_preds(filter, rec)) |
bac5fb97 TZ |
82 | continue; |
83 | if (data->cmd_ops->post_trigger) { | |
84 | tt |= data->cmd_ops->trigger_type; | |
85 | continue; | |
86 | } | |
85f2b082 | 87 | data->ops->func(data); |
bac5fb97 TZ |
88 | } |
89 | return tt; | |
85f2b082 TZ |
90 | } |
91 | EXPORT_SYMBOL_GPL(event_triggers_call); | |
92 | ||
bac5fb97 TZ |
93 | /** |
94 | * event_triggers_post_call - Call 'post_triggers' for a trace event | |
7f1d2f82 | 95 | * @file: The trace_event_file associated with the event |
bac5fb97 TZ |
96 | * @tt: enum event_trigger_type containing a set bit for each trigger to invoke |
97 | * | |
98 | * For each trigger associated with an event, invoke the trigger | |
99 | * function registered with the associated trigger command, if the | |
100 | * corresponding bit is set in the tt enum passed into this function. | |
101 | * See @event_triggers_call for details on how those bits are set. | |
102 | * | |
103 | * Called from tracepoint handlers (with rcu_read_lock_sched() held). | |
104 | */ | |
105 | void | |
7f1d2f82 | 106 | event_triggers_post_call(struct trace_event_file *file, |
bac5fb97 TZ |
107 | enum event_trigger_type tt) |
108 | { | |
109 | struct event_trigger_data *data; | |
110 | ||
111 | list_for_each_entry_rcu(data, &file->triggers, list) { | |
112 | if (data->cmd_ops->trigger_type & tt) | |
113 | data->ops->func(data); | |
114 | } | |
115 | } | |
116 | EXPORT_SYMBOL_GPL(event_triggers_post_call); | |
117 | ||
dd97b954 SRRH |
118 | #define SHOW_AVAILABLE_TRIGGERS (void *)(1UL) |
119 | ||
85f2b082 TZ |
120 | static void *trigger_next(struct seq_file *m, void *t, loff_t *pos) |
121 | { | |
7f1d2f82 | 122 | struct trace_event_file *event_file = event_file_data(m->private); |
85f2b082 | 123 | |
dd97b954 SRRH |
124 | if (t == SHOW_AVAILABLE_TRIGGERS) |
125 | return NULL; | |
126 | ||
85f2b082 TZ |
127 | return seq_list_next(t, &event_file->triggers, pos); |
128 | } | |
129 | ||
130 | static void *trigger_start(struct seq_file *m, loff_t *pos) | |
131 | { | |
7f1d2f82 | 132 | struct trace_event_file *event_file; |
85f2b082 TZ |
133 | |
134 | /* ->stop() is called even if ->start() fails */ | |
135 | mutex_lock(&event_mutex); | |
136 | event_file = event_file_data(m->private); | |
137 | if (unlikely(!event_file)) | |
138 | return ERR_PTR(-ENODEV); | |
139 | ||
dd97b954 SRRH |
140 | if (list_empty(&event_file->triggers)) |
141 | return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL; | |
142 | ||
85f2b082 TZ |
143 | return seq_list_start(&event_file->triggers, *pos); |
144 | } | |
145 | ||
146 | static void trigger_stop(struct seq_file *m, void *t) | |
147 | { | |
148 | mutex_unlock(&event_mutex); | |
149 | } | |
150 | ||
151 | static int trigger_show(struct seq_file *m, void *v) | |
152 | { | |
153 | struct event_trigger_data *data; | |
dd97b954 SRRH |
154 | struct event_command *p; |
155 | ||
156 | if (v == SHOW_AVAILABLE_TRIGGERS) { | |
157 | seq_puts(m, "# Available triggers:\n"); | |
158 | seq_putc(m, '#'); | |
159 | mutex_lock(&trigger_cmd_mutex); | |
160 | list_for_each_entry_reverse(p, &trigger_commands, list) | |
161 | seq_printf(m, " %s", p->name); | |
162 | seq_putc(m, '\n'); | |
163 | mutex_unlock(&trigger_cmd_mutex); | |
164 | return 0; | |
165 | } | |
85f2b082 TZ |
166 | |
167 | data = list_entry(v, struct event_trigger_data, list); | |
168 | data->ops->print(m, data->ops, data); | |
169 | ||
170 | return 0; | |
171 | } | |
172 | ||
173 | static const struct seq_operations event_triggers_seq_ops = { | |
174 | .start = trigger_start, | |
175 | .next = trigger_next, | |
176 | .stop = trigger_stop, | |
177 | .show = trigger_show, | |
178 | }; | |
179 | ||
180 | static int event_trigger_regex_open(struct inode *inode, struct file *file) | |
181 | { | |
182 | int ret = 0; | |
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_READ) { | |
192 | ret = seq_open(file, &event_triggers_seq_ops); | |
193 | if (!ret) { | |
194 | struct seq_file *m = file->private_data; | |
195 | m->private = file; | |
196 | } | |
197 | } | |
198 | ||
199 | mutex_unlock(&event_mutex); | |
200 | ||
201 | return ret; | |
202 | } | |
203 | ||
7f1d2f82 | 204 | static int trigger_process_regex(struct trace_event_file *file, char *buff) |
85f2b082 TZ |
205 | { |
206 | char *command, *next = buff; | |
207 | struct event_command *p; | |
208 | int ret = -EINVAL; | |
209 | ||
210 | command = strsep(&next, ": \t"); | |
211 | command = (command[0] != '!') ? command : command + 1; | |
212 | ||
213 | mutex_lock(&trigger_cmd_mutex); | |
214 | list_for_each_entry(p, &trigger_commands, list) { | |
215 | if (strcmp(p->name, command) == 0) { | |
216 | ret = p->func(p, file, buff, command, next); | |
217 | goto out_unlock; | |
218 | } | |
219 | } | |
220 | out_unlock: | |
221 | mutex_unlock(&trigger_cmd_mutex); | |
222 | ||
223 | return ret; | |
224 | } | |
225 | ||
226 | static ssize_t event_trigger_regex_write(struct file *file, | |
227 | const char __user *ubuf, | |
228 | size_t cnt, loff_t *ppos) | |
229 | { | |
7f1d2f82 | 230 | struct trace_event_file *event_file; |
85f2b082 TZ |
231 | ssize_t ret; |
232 | char *buf; | |
233 | ||
234 | if (!cnt) | |
235 | return 0; | |
236 | ||
237 | if (cnt >= PAGE_SIZE) | |
238 | return -EINVAL; | |
239 | ||
240 | buf = (char *)__get_free_page(GFP_TEMPORARY); | |
241 | if (!buf) | |
242 | return -ENOMEM; | |
243 | ||
244 | if (copy_from_user(buf, ubuf, cnt)) { | |
245 | free_page((unsigned long)buf); | |
246 | return -EFAULT; | |
247 | } | |
248 | buf[cnt] = '\0'; | |
249 | strim(buf); | |
250 | ||
251 | mutex_lock(&event_mutex); | |
252 | event_file = event_file_data(file); | |
253 | if (unlikely(!event_file)) { | |
254 | mutex_unlock(&event_mutex); | |
255 | free_page((unsigned long)buf); | |
256 | return -ENODEV; | |
257 | } | |
258 | ret = trigger_process_regex(event_file, buf); | |
259 | mutex_unlock(&event_mutex); | |
260 | ||
261 | free_page((unsigned long)buf); | |
262 | if (ret < 0) | |
263 | goto out; | |
264 | ||
265 | *ppos += cnt; | |
266 | ret = cnt; | |
267 | out: | |
268 | return ret; | |
269 | } | |
270 | ||
271 | static int event_trigger_regex_release(struct inode *inode, struct file *file) | |
272 | { | |
273 | mutex_lock(&event_mutex); | |
274 | ||
275 | if (file->f_mode & FMODE_READ) | |
276 | seq_release(inode, file); | |
277 | ||
278 | mutex_unlock(&event_mutex); | |
279 | ||
280 | return 0; | |
281 | } | |
282 | ||
283 | static ssize_t | |
284 | event_trigger_write(struct file *filp, const char __user *ubuf, | |
285 | size_t cnt, loff_t *ppos) | |
286 | { | |
287 | return event_trigger_regex_write(filp, ubuf, cnt, ppos); | |
288 | } | |
289 | ||
290 | static int | |
291 | event_trigger_open(struct inode *inode, struct file *filp) | |
292 | { | |
293 | return event_trigger_regex_open(inode, filp); | |
294 | } | |
295 | ||
296 | static int | |
297 | event_trigger_release(struct inode *inode, struct file *file) | |
298 | { | |
299 | return event_trigger_regex_release(inode, file); | |
300 | } | |
301 | ||
302 | const struct file_operations event_trigger_fops = { | |
303 | .open = event_trigger_open, | |
304 | .read = seq_read, | |
305 | .write = event_trigger_write, | |
098c879e | 306 | .llseek = tracing_lseek, |
85f2b082 TZ |
307 | .release = event_trigger_release, |
308 | }; | |
309 | ||
2a2df321 TZ |
310 | /* |
311 | * Currently we only register event commands from __init, so mark this | |
312 | * __init too. | |
313 | */ | |
314 | static __init int register_event_command(struct event_command *cmd) | |
315 | { | |
316 | struct event_command *p; | |
317 | int ret = 0; | |
318 | ||
319 | mutex_lock(&trigger_cmd_mutex); | |
320 | list_for_each_entry(p, &trigger_commands, list) { | |
321 | if (strcmp(cmd->name, p->name) == 0) { | |
322 | ret = -EBUSY; | |
323 | goto out_unlock; | |
324 | } | |
325 | } | |
326 | list_add(&cmd->list, &trigger_commands); | |
327 | out_unlock: | |
328 | mutex_unlock(&trigger_cmd_mutex); | |
329 | ||
330 | return ret; | |
331 | } | |
332 | ||
333 | /* | |
334 | * Currently we only unregister event commands from __init, so mark | |
335 | * this __init too. | |
336 | */ | |
337 | static __init int unregister_event_command(struct event_command *cmd) | |
338 | { | |
339 | struct event_command *p, *n; | |
340 | int ret = -ENODEV; | |
341 | ||
342 | mutex_lock(&trigger_cmd_mutex); | |
343 | list_for_each_entry_safe(p, n, &trigger_commands, list) { | |
344 | if (strcmp(cmd->name, p->name) == 0) { | |
345 | ret = 0; | |
346 | list_del_init(&p->list); | |
347 | goto out_unlock; | |
348 | } | |
349 | } | |
350 | out_unlock: | |
351 | mutex_unlock(&trigger_cmd_mutex); | |
352 | ||
353 | return ret; | |
354 | } | |
355 | ||
356 | /** | |
357 | * event_trigger_print - Generic event_trigger_ops @print implementation | |
358 | * @name: The name of the event trigger | |
359 | * @m: The seq_file being printed to | |
360 | * @data: Trigger-specific data | |
361 | * @filter_str: filter_str to print, if present | |
362 | * | |
363 | * Common implementation for event triggers to print themselves. | |
364 | * | |
365 | * Usually wrapped by a function that simply sets the @name of the | |
366 | * trigger command and then invokes this. | |
367 | * | |
368 | * Return: 0 on success, errno otherwise | |
369 | */ | |
370 | static int | |
371 | event_trigger_print(const char *name, struct seq_file *m, | |
372 | void *data, char *filter_str) | |
373 | { | |
374 | long count = (long)data; | |
375 | ||
fa6f0cc7 | 376 | seq_puts(m, name); |
2a2df321 TZ |
377 | |
378 | if (count == -1) | |
379 | seq_puts(m, ":unlimited"); | |
380 | else | |
381 | seq_printf(m, ":count=%ld", count); | |
382 | ||
383 | if (filter_str) | |
384 | seq_printf(m, " if %s\n", filter_str); | |
385 | else | |
1177e436 | 386 | seq_putc(m, '\n'); |
2a2df321 TZ |
387 | |
388 | return 0; | |
389 | } | |
390 | ||
391 | /** | |
392 | * event_trigger_init - Generic event_trigger_ops @init implementation | |
393 | * @ops: The trigger ops associated with the trigger | |
394 | * @data: Trigger-specific data | |
395 | * | |
396 | * Common implementation of event trigger initialization. | |
397 | * | |
398 | * Usually used directly as the @init method in event trigger | |
399 | * implementations. | |
400 | * | |
401 | * Return: 0 on success, errno otherwise | |
402 | */ | |
403 | static int | |
404 | event_trigger_init(struct event_trigger_ops *ops, | |
405 | struct event_trigger_data *data) | |
406 | { | |
407 | data->ref++; | |
408 | return 0; | |
409 | } | |
410 | ||
411 | /** | |
412 | * event_trigger_free - Generic event_trigger_ops @free implementation | |
413 | * @ops: The trigger ops associated with the trigger | |
414 | * @data: Trigger-specific data | |
415 | * | |
416 | * Common implementation of event trigger de-initialization. | |
417 | * | |
418 | * Usually used directly as the @free method in event trigger | |
419 | * implementations. | |
420 | */ | |
421 | static void | |
422 | event_trigger_free(struct event_trigger_ops *ops, | |
423 | struct event_trigger_data *data) | |
424 | { | |
425 | if (WARN_ON_ONCE(data->ref <= 0)) | |
426 | return; | |
427 | ||
428 | data->ref--; | |
429 | if (!data->ref) | |
430 | trigger_data_free(data); | |
431 | } | |
432 | ||
7f1d2f82 | 433 | static int trace_event_trigger_enable_disable(struct trace_event_file *file, |
85f2b082 TZ |
434 | int trigger_enable) |
435 | { | |
436 | int ret = 0; | |
437 | ||
438 | if (trigger_enable) { | |
439 | if (atomic_inc_return(&file->tm_ref) > 1) | |
440 | return ret; | |
5d6ad960 | 441 | set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags); |
85f2b082 TZ |
442 | ret = trace_event_enable_disable(file, 1, 1); |
443 | } else { | |
444 | if (atomic_dec_return(&file->tm_ref) > 0) | |
445 | return ret; | |
5d6ad960 | 446 | clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags); |
85f2b082 TZ |
447 | ret = trace_event_enable_disable(file, 0, 1); |
448 | } | |
449 | ||
450 | return ret; | |
451 | } | |
452 | ||
453 | /** | |
454 | * clear_event_triggers - Clear all triggers associated with a trace array | |
455 | * @tr: The trace array to clear | |
456 | * | |
457 | * For each trigger, the triggering event has its tm_ref decremented | |
458 | * via trace_event_trigger_enable_disable(), and any associated event | |
459 | * (in the case of enable/disable_event triggers) will have its sm_ref | |
460 | * decremented via free()->trace_event_enable_disable(). That | |
461 | * combination effectively reverses the soft-mode/trigger state added | |
462 | * by trigger registration. | |
463 | * | |
464 | * Must be called with event_mutex held. | |
465 | */ | |
466 | void | |
467 | clear_event_triggers(struct trace_array *tr) | |
468 | { | |
7f1d2f82 | 469 | struct trace_event_file *file; |
85f2b082 TZ |
470 | |
471 | list_for_each_entry(file, &tr->events, list) { | |
472 | struct event_trigger_data *data; | |
473 | list_for_each_entry_rcu(data, &file->triggers, list) { | |
474 | trace_event_trigger_enable_disable(file, 0); | |
475 | if (data->ops->free) | |
476 | data->ops->free(data->ops, data); | |
477 | } | |
478 | } | |
479 | } | |
480 | ||
bac5fb97 TZ |
481 | /** |
482 | * update_cond_flag - Set or reset the TRIGGER_COND bit | |
7f1d2f82 | 483 | * @file: The trace_event_file associated with the event |
bac5fb97 TZ |
484 | * |
485 | * If an event has triggers and any of those triggers has a filter or | |
486 | * a post_trigger, trigger invocation needs to be deferred until after | |
487 | * the current event has logged its data, and the event should have | |
488 | * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be | |
489 | * cleared. | |
490 | */ | |
7f1d2f82 | 491 | static void update_cond_flag(struct trace_event_file *file) |
bac5fb97 TZ |
492 | { |
493 | struct event_trigger_data *data; | |
494 | bool set_cond = false; | |
495 | ||
496 | list_for_each_entry_rcu(data, &file->triggers, list) { | |
497 | if (data->filter || data->cmd_ops->post_trigger) { | |
498 | set_cond = true; | |
499 | break; | |
500 | } | |
501 | } | |
502 | ||
503 | if (set_cond) | |
5d6ad960 | 504 | set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags); |
bac5fb97 | 505 | else |
5d6ad960 | 506 | clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags); |
bac5fb97 TZ |
507 | } |
508 | ||
2a2df321 TZ |
509 | /** |
510 | * register_trigger - Generic event_command @reg implementation | |
511 | * @glob: The raw string used to register the trigger | |
512 | * @ops: The trigger ops associated with the trigger | |
513 | * @data: Trigger-specific data to associate with the trigger | |
7f1d2f82 | 514 | * @file: The trace_event_file associated with the event |
2a2df321 TZ |
515 | * |
516 | * Common implementation for event trigger registration. | |
517 | * | |
518 | * Usually used directly as the @reg method in event command | |
519 | * implementations. | |
520 | * | |
521 | * Return: 0 on success, errno otherwise | |
522 | */ | |
523 | static int register_trigger(char *glob, struct event_trigger_ops *ops, | |
524 | struct event_trigger_data *data, | |
7f1d2f82 | 525 | struct trace_event_file *file) |
2a2df321 TZ |
526 | { |
527 | struct event_trigger_data *test; | |
528 | int ret = 0; | |
529 | ||
530 | list_for_each_entry_rcu(test, &file->triggers, list) { | |
531 | if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) { | |
532 | ret = -EEXIST; | |
533 | goto out; | |
534 | } | |
535 | } | |
536 | ||
537 | if (data->ops->init) { | |
538 | ret = data->ops->init(data->ops, data); | |
539 | if (ret < 0) | |
540 | goto out; | |
541 | } | |
542 | ||
543 | list_add_rcu(&data->list, &file->triggers); | |
544 | ret++; | |
545 | ||
546 | if (trace_event_trigger_enable_disable(file, 1) < 0) { | |
547 | list_del_rcu(&data->list); | |
548 | ret--; | |
549 | } | |
bac5fb97 | 550 | update_cond_flag(file); |
2a2df321 TZ |
551 | out: |
552 | return ret; | |
553 | } | |
554 | ||
555 | /** | |
556 | * unregister_trigger - Generic event_command @unreg implementation | |
557 | * @glob: The raw string used to register the trigger | |
558 | * @ops: The trigger ops associated with the trigger | |
559 | * @test: Trigger-specific data used to find the trigger to remove | |
7f1d2f82 | 560 | * @file: The trace_event_file associated with the event |
2a2df321 TZ |
561 | * |
562 | * Common implementation for event trigger unregistration. | |
563 | * | |
564 | * Usually used directly as the @unreg method in event command | |
565 | * implementations. | |
566 | */ | |
567 | static void unregister_trigger(char *glob, struct event_trigger_ops *ops, | |
568 | struct event_trigger_data *test, | |
7f1d2f82 | 569 | struct trace_event_file *file) |
2a2df321 TZ |
570 | { |
571 | struct event_trigger_data *data; | |
572 | bool unregistered = false; | |
573 | ||
574 | list_for_each_entry_rcu(data, &file->triggers, list) { | |
575 | if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) { | |
576 | unregistered = true; | |
577 | list_del_rcu(&data->list); | |
bac5fb97 | 578 | update_cond_flag(file); |
2a2df321 TZ |
579 | trace_event_trigger_enable_disable(file, 0); |
580 | break; | |
581 | } | |
582 | } | |
583 | ||
584 | if (unregistered && data->ops->free) | |
585 | data->ops->free(data->ops, data); | |
586 | } | |
587 | ||
588 | /** | |
589 | * event_trigger_callback - Generic event_command @func implementation | |
590 | * @cmd_ops: The command ops, used for trigger registration | |
7f1d2f82 | 591 | * @file: The trace_event_file associated with the event |
2a2df321 TZ |
592 | * @glob: The raw string used to register the trigger |
593 | * @cmd: The cmd portion of the string used to register the trigger | |
594 | * @param: The params portion of the string used to register the trigger | |
595 | * | |
596 | * Common implementation for event command parsing and trigger | |
597 | * instantiation. | |
598 | * | |
599 | * Usually used directly as the @func method in event command | |
600 | * implementations. | |
601 | * | |
602 | * Return: 0 on success, errno otherwise | |
603 | */ | |
604 | static int | |
605 | event_trigger_callback(struct event_command *cmd_ops, | |
7f1d2f82 | 606 | struct trace_event_file *file, |
2a2df321 TZ |
607 | char *glob, char *cmd, char *param) |
608 | { | |
609 | struct event_trigger_data *trigger_data; | |
610 | struct event_trigger_ops *trigger_ops; | |
611 | char *trigger = NULL; | |
612 | char *number; | |
613 | int ret; | |
614 | ||
615 | /* separate the trigger from the filter (t:n [if filter]) */ | |
616 | if (param && isdigit(param[0])) | |
617 | trigger = strsep(¶m, " \t"); | |
618 | ||
619 | trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger); | |
620 | ||
621 | ret = -ENOMEM; | |
622 | trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL); | |
623 | if (!trigger_data) | |
624 | goto out; | |
625 | ||
626 | trigger_data->count = -1; | |
627 | trigger_data->ops = trigger_ops; | |
628 | trigger_data->cmd_ops = cmd_ops; | |
629 | INIT_LIST_HEAD(&trigger_data->list); | |
630 | ||
631 | if (glob[0] == '!') { | |
632 | cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); | |
633 | kfree(trigger_data); | |
634 | ret = 0; | |
635 | goto out; | |
636 | } | |
637 | ||
638 | if (trigger) { | |
639 | number = strsep(&trigger, ":"); | |
640 | ||
641 | ret = -EINVAL; | |
642 | if (!strlen(number)) | |
643 | goto out_free; | |
644 | ||
645 | /* | |
646 | * We use the callback data field (which is a pointer) | |
647 | * as our counter. | |
648 | */ | |
649 | ret = kstrtoul(number, 0, &trigger_data->count); | |
650 | if (ret) | |
651 | goto out_free; | |
652 | } | |
653 | ||
654 | if (!param) /* if param is non-empty, it's supposed to be a filter */ | |
655 | goto out_reg; | |
656 | ||
657 | if (!cmd_ops->set_filter) | |
658 | goto out_reg; | |
659 | ||
660 | ret = cmd_ops->set_filter(param, trigger_data, file); | |
661 | if (ret < 0) | |
662 | goto out_free; | |
663 | ||
664 | out_reg: | |
665 | ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); | |
666 | /* | |
667 | * The above returns on success the # of functions enabled, | |
668 | * but if it didn't find any functions it returns zero. | |
669 | * Consider no functions a failure too. | |
670 | */ | |
671 | if (!ret) { | |
672 | ret = -ENOENT; | |
673 | goto out_free; | |
674 | } else if (ret < 0) | |
675 | goto out_free; | |
676 | ret = 0; | |
677 | out: | |
678 | return ret; | |
679 | ||
680 | out_free: | |
bac5fb97 TZ |
681 | if (cmd_ops->set_filter) |
682 | cmd_ops->set_filter(NULL, trigger_data, NULL); | |
2a2df321 TZ |
683 | kfree(trigger_data); |
684 | goto out; | |
685 | } | |
686 | ||
bac5fb97 TZ |
687 | /** |
688 | * set_trigger_filter - Generic event_command @set_filter implementation | |
689 | * @filter_str: The filter string for the trigger, NULL to remove filter | |
690 | * @trigger_data: Trigger-specific data | |
7f1d2f82 | 691 | * @file: The trace_event_file associated with the event |
bac5fb97 TZ |
692 | * |
693 | * Common implementation for event command filter parsing and filter | |
694 | * instantiation. | |
695 | * | |
696 | * Usually used directly as the @set_filter method in event command | |
697 | * implementations. | |
698 | * | |
699 | * Also used to remove a filter (if filter_str = NULL). | |
700 | * | |
701 | * Return: 0 on success, errno otherwise | |
702 | */ | |
703 | static int set_trigger_filter(char *filter_str, | |
704 | struct event_trigger_data *trigger_data, | |
7f1d2f82 | 705 | struct trace_event_file *file) |
bac5fb97 TZ |
706 | { |
707 | struct event_trigger_data *data = trigger_data; | |
708 | struct event_filter *filter = NULL, *tmp; | |
709 | int ret = -EINVAL; | |
710 | char *s; | |
711 | ||
712 | if (!filter_str) /* clear the current filter */ | |
713 | goto assign; | |
714 | ||
715 | s = strsep(&filter_str, " \t"); | |
716 | ||
717 | if (!strlen(s) || strcmp(s, "if") != 0) | |
718 | goto out; | |
719 | ||
720 | if (!filter_str) | |
721 | goto out; | |
722 | ||
723 | /* The filter is for the 'trigger' event, not the triggered event */ | |
724 | ret = create_event_filter(file->event_call, filter_str, false, &filter); | |
725 | if (ret) | |
726 | goto out; | |
727 | assign: | |
d8a30f20 | 728 | tmp = rcu_access_pointer(data->filter); |
bac5fb97 TZ |
729 | |
730 | rcu_assign_pointer(data->filter, filter); | |
731 | ||
732 | if (tmp) { | |
733 | /* Make sure the call is done with the filter */ | |
734 | synchronize_sched(); | |
735 | free_event_filter(tmp); | |
736 | } | |
737 | ||
738 | kfree(data->filter_str); | |
739 | data->filter_str = NULL; | |
740 | ||
741 | if (filter_str) { | |
742 | data->filter_str = kstrdup(filter_str, GFP_KERNEL); | |
743 | if (!data->filter_str) { | |
d8a30f20 | 744 | free_event_filter(rcu_access_pointer(data->filter)); |
bac5fb97 TZ |
745 | data->filter = NULL; |
746 | ret = -ENOMEM; | |
747 | } | |
748 | } | |
749 | out: | |
750 | return ret; | |
751 | } | |
752 | ||
2a2df321 TZ |
753 | static void |
754 | traceon_trigger(struct event_trigger_data *data) | |
755 | { | |
756 | if (tracing_is_on()) | |
757 | return; | |
758 | ||
759 | tracing_on(); | |
760 | } | |
761 | ||
762 | static void | |
763 | traceon_count_trigger(struct event_trigger_data *data) | |
764 | { | |
e8dc6371 SRRH |
765 | if (tracing_is_on()) |
766 | return; | |
767 | ||
2a2df321 TZ |
768 | if (!data->count) |
769 | return; | |
770 | ||
771 | if (data->count != -1) | |
772 | (data->count)--; | |
773 | ||
e8dc6371 | 774 | tracing_on(); |
2a2df321 TZ |
775 | } |
776 | ||
777 | static void | |
778 | traceoff_trigger(struct event_trigger_data *data) | |
779 | { | |
780 | if (!tracing_is_on()) | |
781 | return; | |
782 | ||
783 | tracing_off(); | |
784 | } | |
785 | ||
786 | static void | |
787 | traceoff_count_trigger(struct event_trigger_data *data) | |
788 | { | |
e8dc6371 SRRH |
789 | if (!tracing_is_on()) |
790 | return; | |
791 | ||
2a2df321 TZ |
792 | if (!data->count) |
793 | return; | |
794 | ||
795 | if (data->count != -1) | |
796 | (data->count)--; | |
797 | ||
e8dc6371 | 798 | tracing_off(); |
2a2df321 TZ |
799 | } |
800 | ||
801 | static int | |
802 | traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, | |
803 | struct event_trigger_data *data) | |
804 | { | |
805 | return event_trigger_print("traceon", m, (void *)data->count, | |
806 | data->filter_str); | |
807 | } | |
808 | ||
809 | static int | |
810 | traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, | |
811 | struct event_trigger_data *data) | |
812 | { | |
813 | return event_trigger_print("traceoff", m, (void *)data->count, | |
814 | data->filter_str); | |
815 | } | |
816 | ||
817 | static struct event_trigger_ops traceon_trigger_ops = { | |
818 | .func = traceon_trigger, | |
819 | .print = traceon_trigger_print, | |
820 | .init = event_trigger_init, | |
821 | .free = event_trigger_free, | |
822 | }; | |
823 | ||
824 | static struct event_trigger_ops traceon_count_trigger_ops = { | |
825 | .func = traceon_count_trigger, | |
826 | .print = traceon_trigger_print, | |
827 | .init = event_trigger_init, | |
828 | .free = event_trigger_free, | |
829 | }; | |
830 | ||
831 | static struct event_trigger_ops traceoff_trigger_ops = { | |
832 | .func = traceoff_trigger, | |
833 | .print = traceoff_trigger_print, | |
834 | .init = event_trigger_init, | |
835 | .free = event_trigger_free, | |
836 | }; | |
837 | ||
838 | static struct event_trigger_ops traceoff_count_trigger_ops = { | |
839 | .func = traceoff_count_trigger, | |
840 | .print = traceoff_trigger_print, | |
841 | .init = event_trigger_init, | |
842 | .free = event_trigger_free, | |
843 | }; | |
844 | ||
845 | static struct event_trigger_ops * | |
846 | onoff_get_trigger_ops(char *cmd, char *param) | |
847 | { | |
848 | struct event_trigger_ops *ops; | |
849 | ||
850 | /* we register both traceon and traceoff to this callback */ | |
851 | if (strcmp(cmd, "traceon") == 0) | |
852 | ops = param ? &traceon_count_trigger_ops : | |
853 | &traceon_trigger_ops; | |
854 | else | |
855 | ops = param ? &traceoff_count_trigger_ops : | |
856 | &traceoff_trigger_ops; | |
857 | ||
858 | return ops; | |
859 | } | |
860 | ||
861 | static struct event_command trigger_traceon_cmd = { | |
862 | .name = "traceon", | |
863 | .trigger_type = ETT_TRACE_ONOFF, | |
864 | .func = event_trigger_callback, | |
865 | .reg = register_trigger, | |
866 | .unreg = unregister_trigger, | |
867 | .get_trigger_ops = onoff_get_trigger_ops, | |
bac5fb97 | 868 | .set_filter = set_trigger_filter, |
2a2df321 TZ |
869 | }; |
870 | ||
871 | static struct event_command trigger_traceoff_cmd = { | |
872 | .name = "traceoff", | |
873 | .trigger_type = ETT_TRACE_ONOFF, | |
874 | .func = event_trigger_callback, | |
875 | .reg = register_trigger, | |
876 | .unreg = unregister_trigger, | |
877 | .get_trigger_ops = onoff_get_trigger_ops, | |
bac5fb97 | 878 | .set_filter = set_trigger_filter, |
2a2df321 TZ |
879 | }; |
880 | ||
93e31ffb TZ |
881 | #ifdef CONFIG_TRACER_SNAPSHOT |
882 | static void | |
883 | snapshot_trigger(struct event_trigger_data *data) | |
884 | { | |
885 | tracing_snapshot(); | |
886 | } | |
887 | ||
888 | static void | |
889 | snapshot_count_trigger(struct event_trigger_data *data) | |
890 | { | |
891 | if (!data->count) | |
892 | return; | |
893 | ||
894 | if (data->count != -1) | |
895 | (data->count)--; | |
896 | ||
897 | snapshot_trigger(data); | |
898 | } | |
899 | ||
900 | static int | |
901 | register_snapshot_trigger(char *glob, struct event_trigger_ops *ops, | |
902 | struct event_trigger_data *data, | |
7f1d2f82 | 903 | struct trace_event_file *file) |
93e31ffb TZ |
904 | { |
905 | int ret = register_trigger(glob, ops, data, file); | |
906 | ||
907 | if (ret > 0 && tracing_alloc_snapshot() != 0) { | |
908 | unregister_trigger(glob, ops, data, file); | |
909 | ret = 0; | |
910 | } | |
911 | ||
912 | return ret; | |
913 | } | |
914 | ||
915 | static int | |
916 | snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, | |
917 | struct event_trigger_data *data) | |
918 | { | |
919 | return event_trigger_print("snapshot", m, (void *)data->count, | |
920 | data->filter_str); | |
921 | } | |
922 | ||
923 | static struct event_trigger_ops snapshot_trigger_ops = { | |
924 | .func = snapshot_trigger, | |
925 | .print = snapshot_trigger_print, | |
926 | .init = event_trigger_init, | |
927 | .free = event_trigger_free, | |
928 | }; | |
929 | ||
930 | static struct event_trigger_ops snapshot_count_trigger_ops = { | |
931 | .func = snapshot_count_trigger, | |
932 | .print = snapshot_trigger_print, | |
933 | .init = event_trigger_init, | |
934 | .free = event_trigger_free, | |
935 | }; | |
936 | ||
937 | static struct event_trigger_ops * | |
938 | snapshot_get_trigger_ops(char *cmd, char *param) | |
939 | { | |
940 | return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops; | |
941 | } | |
942 | ||
943 | static struct event_command trigger_snapshot_cmd = { | |
944 | .name = "snapshot", | |
945 | .trigger_type = ETT_SNAPSHOT, | |
946 | .func = event_trigger_callback, | |
947 | .reg = register_snapshot_trigger, | |
948 | .unreg = unregister_trigger, | |
949 | .get_trigger_ops = snapshot_get_trigger_ops, | |
bac5fb97 | 950 | .set_filter = set_trigger_filter, |
93e31ffb TZ |
951 | }; |
952 | ||
953 | static __init int register_trigger_snapshot_cmd(void) | |
954 | { | |
955 | int ret; | |
956 | ||
957 | ret = register_event_command(&trigger_snapshot_cmd); | |
958 | WARN_ON(ret < 0); | |
959 | ||
960 | return ret; | |
961 | } | |
962 | #else | |
963 | static __init int register_trigger_snapshot_cmd(void) { return 0; } | |
964 | #endif /* CONFIG_TRACER_SNAPSHOT */ | |
965 | ||
f21ecbb3 TZ |
966 | #ifdef CONFIG_STACKTRACE |
967 | /* | |
968 | * Skip 3: | |
969 | * stacktrace_trigger() | |
970 | * event_triggers_post_call() | |
a7237765 | 971 | * trace_event_raw_event_xxx() |
f21ecbb3 TZ |
972 | */ |
973 | #define STACK_SKIP 3 | |
974 | ||
975 | static void | |
976 | stacktrace_trigger(struct event_trigger_data *data) | |
977 | { | |
978 | trace_dump_stack(STACK_SKIP); | |
979 | } | |
980 | ||
981 | static void | |
982 | stacktrace_count_trigger(struct event_trigger_data *data) | |
983 | { | |
984 | if (!data->count) | |
985 | return; | |
986 | ||
987 | if (data->count != -1) | |
988 | (data->count)--; | |
989 | ||
990 | stacktrace_trigger(data); | |
991 | } | |
992 | ||
993 | static int | |
994 | stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, | |
995 | struct event_trigger_data *data) | |
996 | { | |
997 | return event_trigger_print("stacktrace", m, (void *)data->count, | |
998 | data->filter_str); | |
999 | } | |
1000 | ||
1001 | static struct event_trigger_ops stacktrace_trigger_ops = { | |
1002 | .func = stacktrace_trigger, | |
1003 | .print = stacktrace_trigger_print, | |
1004 | .init = event_trigger_init, | |
1005 | .free = event_trigger_free, | |
1006 | }; | |
1007 | ||
1008 | static struct event_trigger_ops stacktrace_count_trigger_ops = { | |
1009 | .func = stacktrace_count_trigger, | |
1010 | .print = stacktrace_trigger_print, | |
1011 | .init = event_trigger_init, | |
1012 | .free = event_trigger_free, | |
1013 | }; | |
1014 | ||
1015 | static struct event_trigger_ops * | |
1016 | stacktrace_get_trigger_ops(char *cmd, char *param) | |
1017 | { | |
1018 | return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops; | |
1019 | } | |
1020 | ||
1021 | static struct event_command trigger_stacktrace_cmd = { | |
1022 | .name = "stacktrace", | |
1023 | .trigger_type = ETT_STACKTRACE, | |
1024 | .post_trigger = true, | |
1025 | .func = event_trigger_callback, | |
1026 | .reg = register_trigger, | |
1027 | .unreg = unregister_trigger, | |
1028 | .get_trigger_ops = stacktrace_get_trigger_ops, | |
bac5fb97 | 1029 | .set_filter = set_trigger_filter, |
f21ecbb3 TZ |
1030 | }; |
1031 | ||
1032 | static __init int register_trigger_stacktrace_cmd(void) | |
1033 | { | |
1034 | int ret; | |
1035 | ||
1036 | ret = register_event_command(&trigger_stacktrace_cmd); | |
1037 | WARN_ON(ret < 0); | |
1038 | ||
1039 | return ret; | |
1040 | } | |
1041 | #else | |
1042 | static __init int register_trigger_stacktrace_cmd(void) { return 0; } | |
1043 | #endif /* CONFIG_STACKTRACE */ | |
1044 | ||
2a2df321 TZ |
1045 | static __init void unregister_trigger_traceon_traceoff_cmds(void) |
1046 | { | |
1047 | unregister_event_command(&trigger_traceon_cmd); | |
1048 | unregister_event_command(&trigger_traceoff_cmd); | |
1049 | } | |
1050 | ||
7862ad18 TZ |
1051 | /* Avoid typos */ |
1052 | #define ENABLE_EVENT_STR "enable_event" | |
1053 | #define DISABLE_EVENT_STR "disable_event" | |
1054 | ||
1055 | struct enable_trigger_data { | |
7f1d2f82 | 1056 | struct trace_event_file *file; |
7862ad18 TZ |
1057 | bool enable; |
1058 | }; | |
1059 | ||
1060 | static void | |
1061 | event_enable_trigger(struct event_trigger_data *data) | |
1062 | { | |
1063 | struct enable_trigger_data *enable_data = data->private_data; | |
1064 | ||
1065 | if (enable_data->enable) | |
5d6ad960 | 1066 | clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags); |
7862ad18 | 1067 | else |
5d6ad960 | 1068 | set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags); |
7862ad18 TZ |
1069 | } |
1070 | ||
1071 | static void | |
1072 | event_enable_count_trigger(struct event_trigger_data *data) | |
1073 | { | |
1074 | struct enable_trigger_data *enable_data = data->private_data; | |
1075 | ||
1076 | if (!data->count) | |
1077 | return; | |
1078 | ||
1079 | /* Skip if the event is in a state we want to switch to */ | |
5d6ad960 | 1080 | if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED)) |
7862ad18 TZ |
1081 | return; |
1082 | ||
1083 | if (data->count != -1) | |
1084 | (data->count)--; | |
1085 | ||
1086 | event_enable_trigger(data); | |
1087 | } | |
1088 | ||
1089 | static int | |
1090 | event_enable_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, | |
1091 | struct event_trigger_data *data) | |
1092 | { | |
1093 | struct enable_trigger_data *enable_data = data->private_data; | |
1094 | ||
1095 | seq_printf(m, "%s:%s:%s", | |
1096 | enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR, | |
1097 | enable_data->file->event_call->class->system, | |
687fcc4a | 1098 | trace_event_name(enable_data->file->event_call)); |
7862ad18 TZ |
1099 | |
1100 | if (data->count == -1) | |
1101 | seq_puts(m, ":unlimited"); | |
1102 | else | |
1103 | seq_printf(m, ":count=%ld", data->count); | |
1104 | ||
1105 | if (data->filter_str) | |
1106 | seq_printf(m, " if %s\n", data->filter_str); | |
1107 | else | |
1177e436 | 1108 | seq_putc(m, '\n'); |
7862ad18 TZ |
1109 | |
1110 | return 0; | |
1111 | } | |
1112 | ||
1113 | static void | |
1114 | event_enable_trigger_free(struct event_trigger_ops *ops, | |
1115 | struct event_trigger_data *data) | |
1116 | { | |
1117 | struct enable_trigger_data *enable_data = data->private_data; | |
1118 | ||
1119 | if (WARN_ON_ONCE(data->ref <= 0)) | |
1120 | return; | |
1121 | ||
1122 | data->ref--; | |
1123 | if (!data->ref) { | |
1124 | /* Remove the SOFT_MODE flag */ | |
1125 | trace_event_enable_disable(enable_data->file, 0, 1); | |
1126 | module_put(enable_data->file->event_call->mod); | |
1127 | trigger_data_free(data); | |
1128 | kfree(enable_data); | |
1129 | } | |
1130 | } | |
1131 | ||
1132 | static struct event_trigger_ops event_enable_trigger_ops = { | |
1133 | .func = event_enable_trigger, | |
1134 | .print = event_enable_trigger_print, | |
1135 | .init = event_trigger_init, | |
1136 | .free = event_enable_trigger_free, | |
1137 | }; | |
1138 | ||
1139 | static struct event_trigger_ops event_enable_count_trigger_ops = { | |
1140 | .func = event_enable_count_trigger, | |
1141 | .print = event_enable_trigger_print, | |
1142 | .init = event_trigger_init, | |
1143 | .free = event_enable_trigger_free, | |
1144 | }; | |
1145 | ||
1146 | static struct event_trigger_ops event_disable_trigger_ops = { | |
1147 | .func = event_enable_trigger, | |
1148 | .print = event_enable_trigger_print, | |
1149 | .init = event_trigger_init, | |
1150 | .free = event_enable_trigger_free, | |
1151 | }; | |
1152 | ||
1153 | static struct event_trigger_ops event_disable_count_trigger_ops = { | |
1154 | .func = event_enable_count_trigger, | |
1155 | .print = event_enable_trigger_print, | |
1156 | .init = event_trigger_init, | |
1157 | .free = event_enable_trigger_free, | |
1158 | }; | |
1159 | ||
1160 | static int | |
1161 | event_enable_trigger_func(struct event_command *cmd_ops, | |
7f1d2f82 | 1162 | struct trace_event_file *file, |
7862ad18 TZ |
1163 | char *glob, char *cmd, char *param) |
1164 | { | |
7f1d2f82 | 1165 | struct trace_event_file *event_enable_file; |
7862ad18 TZ |
1166 | struct enable_trigger_data *enable_data; |
1167 | struct event_trigger_data *trigger_data; | |
1168 | struct event_trigger_ops *trigger_ops; | |
1169 | struct trace_array *tr = file->tr; | |
1170 | const char *system; | |
1171 | const char *event; | |
1172 | char *trigger; | |
1173 | char *number; | |
1174 | bool enable; | |
1175 | int ret; | |
1176 | ||
1177 | if (!param) | |
1178 | return -EINVAL; | |
1179 | ||
1180 | /* separate the trigger from the filter (s:e:n [if filter]) */ | |
1181 | trigger = strsep(¶m, " \t"); | |
1182 | if (!trigger) | |
1183 | return -EINVAL; | |
1184 | ||
1185 | system = strsep(&trigger, ":"); | |
1186 | if (!trigger) | |
1187 | return -EINVAL; | |
1188 | ||
1189 | event = strsep(&trigger, ":"); | |
1190 | ||
1191 | ret = -EINVAL; | |
1192 | event_enable_file = find_event_file(tr, system, event); | |
1193 | if (!event_enable_file) | |
1194 | goto out; | |
1195 | ||
1196 | enable = strcmp(cmd, ENABLE_EVENT_STR) == 0; | |
1197 | ||
1198 | trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger); | |
1199 | ||
1200 | ret = -ENOMEM; | |
1201 | trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL); | |
1202 | if (!trigger_data) | |
1203 | goto out; | |
1204 | ||
1205 | enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL); | |
1206 | if (!enable_data) { | |
1207 | kfree(trigger_data); | |
1208 | goto out; | |
1209 | } | |
1210 | ||
1211 | trigger_data->count = -1; | |
1212 | trigger_data->ops = trigger_ops; | |
1213 | trigger_data->cmd_ops = cmd_ops; | |
1214 | INIT_LIST_HEAD(&trigger_data->list); | |
1215 | RCU_INIT_POINTER(trigger_data->filter, NULL); | |
1216 | ||
1217 | enable_data->enable = enable; | |
1218 | enable_data->file = event_enable_file; | |
1219 | trigger_data->private_data = enable_data; | |
1220 | ||
1221 | if (glob[0] == '!') { | |
1222 | cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); | |
1223 | kfree(trigger_data); | |
1224 | kfree(enable_data); | |
1225 | ret = 0; | |
1226 | goto out; | |
1227 | } | |
1228 | ||
1229 | if (trigger) { | |
1230 | number = strsep(&trigger, ":"); | |
1231 | ||
1232 | ret = -EINVAL; | |
1233 | if (!strlen(number)) | |
1234 | goto out_free; | |
1235 | ||
1236 | /* | |
1237 | * We use the callback data field (which is a pointer) | |
1238 | * as our counter. | |
1239 | */ | |
1240 | ret = kstrtoul(number, 0, &trigger_data->count); | |
1241 | if (ret) | |
1242 | goto out_free; | |
1243 | } | |
1244 | ||
1245 | if (!param) /* if param is non-empty, it's supposed to be a filter */ | |
1246 | goto out_reg; | |
1247 | ||
1248 | if (!cmd_ops->set_filter) | |
1249 | goto out_reg; | |
1250 | ||
1251 | ret = cmd_ops->set_filter(param, trigger_data, file); | |
1252 | if (ret < 0) | |
1253 | goto out_free; | |
1254 | ||
1255 | out_reg: | |
1256 | /* Don't let event modules unload while probe registered */ | |
1257 | ret = try_module_get(event_enable_file->event_call->mod); | |
1258 | if (!ret) { | |
1259 | ret = -EBUSY; | |
1260 | goto out_free; | |
1261 | } | |
1262 | ||
1263 | ret = trace_event_enable_disable(event_enable_file, 1, 1); | |
1264 | if (ret < 0) | |
1265 | goto out_put; | |
1266 | ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); | |
1267 | /* | |
1268 | * The above returns on success the # of functions enabled, | |
1269 | * but if it didn't find any functions it returns zero. | |
1270 | * Consider no functions a failure too. | |
1271 | */ | |
1272 | if (!ret) { | |
1273 | ret = -ENOENT; | |
1274 | goto out_disable; | |
1275 | } else if (ret < 0) | |
1276 | goto out_disable; | |
1277 | /* Just return zero, not the number of enabled functions */ | |
1278 | ret = 0; | |
1279 | out: | |
1280 | return ret; | |
1281 | ||
1282 | out_disable: | |
1283 | trace_event_enable_disable(event_enable_file, 0, 1); | |
1284 | out_put: | |
1285 | module_put(event_enable_file->event_call->mod); | |
1286 | out_free: | |
bac5fb97 TZ |
1287 | if (cmd_ops->set_filter) |
1288 | cmd_ops->set_filter(NULL, trigger_data, NULL); | |
7862ad18 TZ |
1289 | kfree(trigger_data); |
1290 | kfree(enable_data); | |
1291 | goto out; | |
1292 | } | |
1293 | ||
1294 | static int event_enable_register_trigger(char *glob, | |
1295 | struct event_trigger_ops *ops, | |
1296 | struct event_trigger_data *data, | |
7f1d2f82 | 1297 | struct trace_event_file *file) |
7862ad18 TZ |
1298 | { |
1299 | struct enable_trigger_data *enable_data = data->private_data; | |
1300 | struct enable_trigger_data *test_enable_data; | |
1301 | struct event_trigger_data *test; | |
1302 | int ret = 0; | |
1303 | ||
1304 | list_for_each_entry_rcu(test, &file->triggers, list) { | |
1305 | test_enable_data = test->private_data; | |
1306 | if (test_enable_data && | |
1307 | (test_enable_data->file == enable_data->file)) { | |
1308 | ret = -EEXIST; | |
1309 | goto out; | |
1310 | } | |
1311 | } | |
1312 | ||
1313 | if (data->ops->init) { | |
1314 | ret = data->ops->init(data->ops, data); | |
1315 | if (ret < 0) | |
1316 | goto out; | |
1317 | } | |
1318 | ||
1319 | list_add_rcu(&data->list, &file->triggers); | |
1320 | ret++; | |
1321 | ||
1322 | if (trace_event_trigger_enable_disable(file, 1) < 0) { | |
1323 | list_del_rcu(&data->list); | |
1324 | ret--; | |
1325 | } | |
bac5fb97 | 1326 | update_cond_flag(file); |
7862ad18 TZ |
1327 | out: |
1328 | return ret; | |
1329 | } | |
1330 | ||
1331 | static void event_enable_unregister_trigger(char *glob, | |
1332 | struct event_trigger_ops *ops, | |
1333 | struct event_trigger_data *test, | |
7f1d2f82 | 1334 | struct trace_event_file *file) |
7862ad18 TZ |
1335 | { |
1336 | struct enable_trigger_data *test_enable_data = test->private_data; | |
1337 | struct enable_trigger_data *enable_data; | |
1338 | struct event_trigger_data *data; | |
1339 | bool unregistered = false; | |
1340 | ||
1341 | list_for_each_entry_rcu(data, &file->triggers, list) { | |
1342 | enable_data = data->private_data; | |
1343 | if (enable_data && | |
1344 | (enable_data->file == test_enable_data->file)) { | |
1345 | unregistered = true; | |
1346 | list_del_rcu(&data->list); | |
bac5fb97 | 1347 | update_cond_flag(file); |
7862ad18 TZ |
1348 | trace_event_trigger_enable_disable(file, 0); |
1349 | break; | |
1350 | } | |
1351 | } | |
1352 | ||
1353 | if (unregistered && data->ops->free) | |
1354 | data->ops->free(data->ops, data); | |
1355 | } | |
1356 | ||
1357 | static struct event_trigger_ops * | |
1358 | event_enable_get_trigger_ops(char *cmd, char *param) | |
1359 | { | |
1360 | struct event_trigger_ops *ops; | |
1361 | bool enable; | |
1362 | ||
1363 | enable = strcmp(cmd, ENABLE_EVENT_STR) == 0; | |
1364 | ||
1365 | if (enable) | |
1366 | ops = param ? &event_enable_count_trigger_ops : | |
1367 | &event_enable_trigger_ops; | |
1368 | else | |
1369 | ops = param ? &event_disable_count_trigger_ops : | |
1370 | &event_disable_trigger_ops; | |
1371 | ||
1372 | return ops; | |
1373 | } | |
1374 | ||
1375 | static struct event_command trigger_enable_cmd = { | |
1376 | .name = ENABLE_EVENT_STR, | |
1377 | .trigger_type = ETT_EVENT_ENABLE, | |
1378 | .func = event_enable_trigger_func, | |
1379 | .reg = event_enable_register_trigger, | |
1380 | .unreg = event_enable_unregister_trigger, | |
1381 | .get_trigger_ops = event_enable_get_trigger_ops, | |
bac5fb97 | 1382 | .set_filter = set_trigger_filter, |
7862ad18 TZ |
1383 | }; |
1384 | ||
1385 | static struct event_command trigger_disable_cmd = { | |
1386 | .name = DISABLE_EVENT_STR, | |
1387 | .trigger_type = ETT_EVENT_ENABLE, | |
1388 | .func = event_enable_trigger_func, | |
1389 | .reg = event_enable_register_trigger, | |
1390 | .unreg = event_enable_unregister_trigger, | |
1391 | .get_trigger_ops = event_enable_get_trigger_ops, | |
bac5fb97 | 1392 | .set_filter = set_trigger_filter, |
7862ad18 TZ |
1393 | }; |
1394 | ||
1395 | static __init void unregister_trigger_enable_disable_cmds(void) | |
1396 | { | |
1397 | unregister_event_command(&trigger_enable_cmd); | |
1398 | unregister_event_command(&trigger_disable_cmd); | |
1399 | } | |
1400 | ||
1401 | static __init int register_trigger_enable_disable_cmds(void) | |
1402 | { | |
1403 | int ret; | |
1404 | ||
1405 | ret = register_event_command(&trigger_enable_cmd); | |
1406 | if (WARN_ON(ret < 0)) | |
1407 | return ret; | |
1408 | ret = register_event_command(&trigger_disable_cmd); | |
1409 | if (WARN_ON(ret < 0)) | |
1410 | unregister_trigger_enable_disable_cmds(); | |
1411 | ||
1412 | return ret; | |
1413 | } | |
1414 | ||
2a2df321 TZ |
1415 | static __init int register_trigger_traceon_traceoff_cmds(void) |
1416 | { | |
1417 | int ret; | |
1418 | ||
1419 | ret = register_event_command(&trigger_traceon_cmd); | |
1420 | if (WARN_ON(ret < 0)) | |
1421 | return ret; | |
1422 | ret = register_event_command(&trigger_traceoff_cmd); | |
1423 | if (WARN_ON(ret < 0)) | |
1424 | unregister_trigger_traceon_traceoff_cmds(); | |
1425 | ||
1426 | return ret; | |
1427 | } | |
1428 | ||
85f2b082 TZ |
1429 | __init int register_trigger_cmds(void) |
1430 | { | |
2a2df321 | 1431 | register_trigger_traceon_traceoff_cmds(); |
93e31ffb | 1432 | register_trigger_snapshot_cmd(); |
f21ecbb3 | 1433 | register_trigger_stacktrace_cmd(); |
7862ad18 | 1434 | register_trigger_enable_disable_cmds(); |
2a2df321 | 1435 | |
85f2b082 TZ |
1436 | return 0; |
1437 | } |