trace_events_trigger.c 42 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * trace_events_trigger - trace event triggers
  4. *
  5. * Copyright (C) 2013 Tom Zanussi <tom.zanussi@linux.intel.com>
  6. */
  7. #include <linux/security.h>
  8. #include <linux/module.h>
  9. #include <linux/ctype.h>
  10. #include <linux/mutex.h>
  11. #include <linux/slab.h>
  12. #include <linux/rculist.h>
  13. #include "trace.h"
  14. static LIST_HEAD(trigger_commands);
  15. static DEFINE_MUTEX(trigger_cmd_mutex);
  16. void trigger_data_free(struct event_trigger_data *data)
  17. {
  18. if (data->cmd_ops->set_filter)
  19. data->cmd_ops->set_filter(NULL, data, NULL);
  20. /* make sure current triggers exit before free */
  21. tracepoint_synchronize_unregister();
  22. kfree(data);
  23. }
  24. /**
  25. * event_triggers_call - Call triggers associated with a trace event
  26. * @file: The trace_event_file associated with the event
  27. * @rec: The trace entry for the event, NULL for unconditional invocation
  28. *
  29. * For each trigger associated with an event, invoke the trigger
  30. * function registered with the associated trigger command. If rec is
  31. * non-NULL, it means that the trigger requires further processing and
  32. * shouldn't be unconditionally invoked. If rec is non-NULL and the
  33. * trigger has a filter associated with it, rec will checked against
  34. * the filter and if the record matches the trigger will be invoked.
  35. * If the trigger is a 'post_trigger', meaning it shouldn't be invoked
  36. * in any case until the current event is written, the trigger
  37. * function isn't invoked but the bit associated with the deferred
  38. * trigger is set in the return value.
  39. *
  40. * Returns an enum event_trigger_type value containing a set bit for
  41. * any trigger that should be deferred, ETT_NONE if nothing to defer.
  42. *
  43. * Called from tracepoint handlers (with rcu_read_lock_sched() held).
  44. *
  45. * Return: an enum event_trigger_type value containing a set bit for
  46. * any trigger that should be deferred, ETT_NONE if nothing to defer.
  47. */
  48. enum event_trigger_type
  49. event_triggers_call(struct trace_event_file *file, void *rec,
  50. struct ring_buffer_event *event)
  51. {
  52. struct event_trigger_data *data;
  53. enum event_trigger_type tt = ETT_NONE;
  54. struct event_filter *filter;
  55. if (list_empty(&file->triggers))
  56. return tt;
  57. list_for_each_entry_rcu(data, &file->triggers, list) {
  58. if (data->paused)
  59. continue;
  60. if (!rec) {
  61. data->ops->func(data, rec, event);
  62. continue;
  63. }
  64. filter = rcu_dereference_sched(data->filter);
  65. if (filter && !filter_match_preds(filter, rec))
  66. continue;
  67. if (event_command_post_trigger(data->cmd_ops)) {
  68. tt |= data->cmd_ops->trigger_type;
  69. continue;
  70. }
  71. data->ops->func(data, rec, event);
  72. }
  73. return tt;
  74. }
  75. EXPORT_SYMBOL_GPL(event_triggers_call);
  76. /**
  77. * event_triggers_post_call - Call 'post_triggers' for a trace event
  78. * @file: The trace_event_file associated with the event
  79. * @tt: enum event_trigger_type containing a set bit for each trigger to invoke
  80. *
  81. * For each trigger associated with an event, invoke the trigger
  82. * function registered with the associated trigger command, if the
  83. * corresponding bit is set in the tt enum passed into this function.
  84. * See @event_triggers_call for details on how those bits are set.
  85. *
  86. * Called from tracepoint handlers (with rcu_read_lock_sched() held).
  87. */
  88. void
  89. event_triggers_post_call(struct trace_event_file *file,
  90. enum event_trigger_type tt)
  91. {
  92. struct event_trigger_data *data;
  93. list_for_each_entry_rcu(data, &file->triggers, list) {
  94. if (data->paused)
  95. continue;
  96. if (data->cmd_ops->trigger_type & tt)
  97. data->ops->func(data, NULL, NULL);
  98. }
  99. }
  100. EXPORT_SYMBOL_GPL(event_triggers_post_call);
  101. #define SHOW_AVAILABLE_TRIGGERS (void *)(1UL)
  102. static void *trigger_next(struct seq_file *m, void *t, loff_t *pos)
  103. {
  104. struct trace_event_file *event_file = event_file_data(m->private);
  105. if (t == SHOW_AVAILABLE_TRIGGERS) {
  106. (*pos)++;
  107. return NULL;
  108. }
  109. return seq_list_next(t, &event_file->triggers, pos);
  110. }
  111. static void *trigger_start(struct seq_file *m, loff_t *pos)
  112. {
  113. struct trace_event_file *event_file;
  114. /* ->stop() is called even if ->start() fails */
  115. mutex_lock(&event_mutex);
  116. event_file = event_file_data(m->private);
  117. if (unlikely(!event_file))
  118. return ERR_PTR(-ENODEV);
  119. if (list_empty(&event_file->triggers))
  120. return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL;
  121. return seq_list_start(&event_file->triggers, *pos);
  122. }
  123. static void trigger_stop(struct seq_file *m, void *t)
  124. {
  125. mutex_unlock(&event_mutex);
  126. }
  127. static int trigger_show(struct seq_file *m, void *v)
  128. {
  129. struct event_trigger_data *data;
  130. struct event_command *p;
  131. if (v == SHOW_AVAILABLE_TRIGGERS) {
  132. seq_puts(m, "# Available triggers:\n");
  133. seq_putc(m, '#');
  134. mutex_lock(&trigger_cmd_mutex);
  135. list_for_each_entry_reverse(p, &trigger_commands, list)
  136. seq_printf(m, " %s", p->name);
  137. seq_putc(m, '\n');
  138. mutex_unlock(&trigger_cmd_mutex);
  139. return 0;
  140. }
  141. data = list_entry(v, struct event_trigger_data, list);
  142. data->ops->print(m, data->ops, data);
  143. return 0;
  144. }
  145. static const struct seq_operations event_triggers_seq_ops = {
  146. .start = trigger_start,
  147. .next = trigger_next,
  148. .stop = trigger_stop,
  149. .show = trigger_show,
  150. };
  151. static int event_trigger_regex_open(struct inode *inode, struct file *file)
  152. {
  153. int ret;
  154. ret = security_locked_down(LOCKDOWN_TRACEFS);
  155. if (ret)
  156. return ret;
  157. mutex_lock(&event_mutex);
  158. if (unlikely(!event_file_data(file))) {
  159. mutex_unlock(&event_mutex);
  160. return -ENODEV;
  161. }
  162. if ((file->f_mode & FMODE_WRITE) &&
  163. (file->f_flags & O_TRUNC)) {
  164. struct trace_event_file *event_file;
  165. struct event_command *p;
  166. event_file = event_file_data(file);
  167. list_for_each_entry(p, &trigger_commands, list) {
  168. if (p->unreg_all)
  169. p->unreg_all(event_file);
  170. }
  171. }
  172. if (file->f_mode & FMODE_READ) {
  173. ret = seq_open(file, &event_triggers_seq_ops);
  174. if (!ret) {
  175. struct seq_file *m = file->private_data;
  176. m->private = file;
  177. }
  178. }
  179. mutex_unlock(&event_mutex);
  180. return ret;
  181. }
  182. int trigger_process_regex(struct trace_event_file *file, char *buff)
  183. {
  184. char *command, *next;
  185. struct event_command *p;
  186. int ret = -EINVAL;
  187. next = buff = skip_spaces(buff);
  188. command = strsep(&next, ": \t");
  189. if (next) {
  190. next = skip_spaces(next);
  191. if (!*next)
  192. next = NULL;
  193. }
  194. command = (command[0] != '!') ? command : command + 1;
  195. mutex_lock(&trigger_cmd_mutex);
  196. list_for_each_entry(p, &trigger_commands, list) {
  197. if (strcmp(p->name, command) == 0) {
  198. ret = p->func(p, file, buff, command, next);
  199. goto out_unlock;
  200. }
  201. }
  202. out_unlock:
  203. mutex_unlock(&trigger_cmd_mutex);
  204. return ret;
  205. }
  206. static ssize_t event_trigger_regex_write(struct file *file,
  207. const char __user *ubuf,
  208. size_t cnt, loff_t *ppos)
  209. {
  210. struct trace_event_file *event_file;
  211. ssize_t ret;
  212. char *buf;
  213. if (!cnt)
  214. return 0;
  215. if (cnt >= PAGE_SIZE)
  216. return -EINVAL;
  217. buf = memdup_user_nul(ubuf, cnt);
  218. if (IS_ERR(buf))
  219. return PTR_ERR(buf);
  220. strim(buf);
  221. mutex_lock(&event_mutex);
  222. event_file = event_file_data(file);
  223. if (unlikely(!event_file)) {
  224. mutex_unlock(&event_mutex);
  225. kfree(buf);
  226. return -ENODEV;
  227. }
  228. ret = trigger_process_regex(event_file, buf);
  229. mutex_unlock(&event_mutex);
  230. kfree(buf);
  231. if (ret < 0)
  232. goto out;
  233. *ppos += cnt;
  234. ret = cnt;
  235. out:
  236. return ret;
  237. }
  238. static int event_trigger_regex_release(struct inode *inode, struct file *file)
  239. {
  240. mutex_lock(&event_mutex);
  241. if (file->f_mode & FMODE_READ)
  242. seq_release(inode, file);
  243. mutex_unlock(&event_mutex);
  244. return 0;
  245. }
  246. static ssize_t
  247. event_trigger_write(struct file *filp, const char __user *ubuf,
  248. size_t cnt, loff_t *ppos)
  249. {
  250. return event_trigger_regex_write(filp, ubuf, cnt, ppos);
  251. }
  252. static int
  253. event_trigger_open(struct inode *inode, struct file *filp)
  254. {
  255. /* Checks for tracefs lockdown */
  256. return event_trigger_regex_open(inode, filp);
  257. }
  258. static int
  259. event_trigger_release(struct inode *inode, struct file *file)
  260. {
  261. return event_trigger_regex_release(inode, file);
  262. }
  263. const struct file_operations event_trigger_fops = {
  264. .open = event_trigger_open,
  265. .read = seq_read,
  266. .write = event_trigger_write,
  267. .llseek = tracing_lseek,
  268. .release = event_trigger_release,
  269. };
  270. /*
  271. * Currently we only register event commands from __init, so mark this
  272. * __init too.
  273. */
  274. __init int register_event_command(struct event_command *cmd)
  275. {
  276. struct event_command *p;
  277. int ret = 0;
  278. mutex_lock(&trigger_cmd_mutex);
  279. list_for_each_entry(p, &trigger_commands, list) {
  280. if (strcmp(cmd->name, p->name) == 0) {
  281. ret = -EBUSY;
  282. goto out_unlock;
  283. }
  284. }
  285. list_add(&cmd->list, &trigger_commands);
  286. out_unlock:
  287. mutex_unlock(&trigger_cmd_mutex);
  288. return ret;
  289. }
  290. /*
  291. * Currently we only unregister event commands from __init, so mark
  292. * this __init too.
  293. */
  294. __init int unregister_event_command(struct event_command *cmd)
  295. {
  296. struct event_command *p, *n;
  297. int ret = -ENODEV;
  298. mutex_lock(&trigger_cmd_mutex);
  299. list_for_each_entry_safe(p, n, &trigger_commands, list) {
  300. if (strcmp(cmd->name, p->name) == 0) {
  301. ret = 0;
  302. list_del_init(&p->list);
  303. goto out_unlock;
  304. }
  305. }
  306. out_unlock:
  307. mutex_unlock(&trigger_cmd_mutex);
  308. return ret;
  309. }
  310. /**
  311. * event_trigger_print - Generic event_trigger_ops @print implementation
  312. * @name: The name of the event trigger
  313. * @m: The seq_file being printed to
  314. * @data: Trigger-specific data
  315. * @filter_str: filter_str to print, if present
  316. *
  317. * Common implementation for event triggers to print themselves.
  318. *
  319. * Usually wrapped by a function that simply sets the @name of the
  320. * trigger command and then invokes this.
  321. *
  322. * Return: 0 on success, errno otherwise
  323. */
  324. static int
  325. event_trigger_print(const char *name, struct seq_file *m,
  326. void *data, char *filter_str)
  327. {
  328. long count = (long)data;
  329. seq_puts(m, name);
  330. if (count == -1)
  331. seq_puts(m, ":unlimited");
  332. else
  333. seq_printf(m, ":count=%ld", count);
  334. if (filter_str)
  335. seq_printf(m, " if %s\n", filter_str);
  336. else
  337. seq_putc(m, '\n');
  338. return 0;
  339. }
  340. /**
  341. * event_trigger_init - Generic event_trigger_ops @init implementation
  342. * @ops: The trigger ops associated with the trigger
  343. * @data: Trigger-specific data
  344. *
  345. * Common implementation of event trigger initialization.
  346. *
  347. * Usually used directly as the @init method in event trigger
  348. * implementations.
  349. *
  350. * Return: 0 on success, errno otherwise
  351. */
  352. int event_trigger_init(struct event_trigger_ops *ops,
  353. struct event_trigger_data *data)
  354. {
  355. data->ref++;
  356. return 0;
  357. }
  358. /**
  359. * event_trigger_free - Generic event_trigger_ops @free implementation
  360. * @ops: The trigger ops associated with the trigger
  361. * @data: Trigger-specific data
  362. *
  363. * Common implementation of event trigger de-initialization.
  364. *
  365. * Usually used directly as the @free method in event trigger
  366. * implementations.
  367. */
  368. static void
  369. event_trigger_free(struct event_trigger_ops *ops,
  370. struct event_trigger_data *data)
  371. {
  372. if (WARN_ON_ONCE(data->ref <= 0))
  373. return;
  374. data->ref--;
  375. if (!data->ref)
  376. trigger_data_free(data);
  377. }
  378. int trace_event_trigger_enable_disable(struct trace_event_file *file,
  379. int trigger_enable)
  380. {
  381. int ret = 0;
  382. if (trigger_enable) {
  383. if (atomic_inc_return(&file->tm_ref) > 1)
  384. return ret;
  385. set_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
  386. ret = trace_event_enable_disable(file, 1, 1);
  387. } else {
  388. if (atomic_dec_return(&file->tm_ref) > 0)
  389. return ret;
  390. clear_bit(EVENT_FILE_FL_TRIGGER_MODE_BIT, &file->flags);
  391. ret = trace_event_enable_disable(file, 0, 1);
  392. }
  393. return ret;
  394. }
  395. /**
  396. * clear_event_triggers - Clear all triggers associated with a trace array
  397. * @tr: The trace array to clear
  398. *
  399. * For each trigger, the triggering event has its tm_ref decremented
  400. * via trace_event_trigger_enable_disable(), and any associated event
  401. * (in the case of enable/disable_event triggers) will have its sm_ref
  402. * decremented via free()->trace_event_enable_disable(). That
  403. * combination effectively reverses the soft-mode/trigger state added
  404. * by trigger registration.
  405. *
  406. * Must be called with event_mutex held.
  407. */
  408. void
  409. clear_event_triggers(struct trace_array *tr)
  410. {
  411. struct trace_event_file *file;
  412. list_for_each_entry(file, &tr->events, list) {
  413. struct event_trigger_data *data, *n;
  414. list_for_each_entry_safe(data, n, &file->triggers, list) {
  415. trace_event_trigger_enable_disable(file, 0);
  416. list_del_rcu(&data->list);
  417. if (data->ops->free)
  418. data->ops->free(data->ops, data);
  419. }
  420. }
  421. }
  422. /**
  423. * update_cond_flag - Set or reset the TRIGGER_COND bit
  424. * @file: The trace_event_file associated with the event
  425. *
  426. * If an event has triggers and any of those triggers has a filter or
  427. * a post_trigger, trigger invocation needs to be deferred until after
  428. * the current event has logged its data, and the event should have
  429. * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be
  430. * cleared.
  431. */
  432. void update_cond_flag(struct trace_event_file *file)
  433. {
  434. struct event_trigger_data *data;
  435. bool set_cond = false;
  436. lockdep_assert_held(&event_mutex);
  437. list_for_each_entry(data, &file->triggers, list) {
  438. if (data->filter || event_command_post_trigger(data->cmd_ops) ||
  439. event_command_needs_rec(data->cmd_ops)) {
  440. set_cond = true;
  441. break;
  442. }
  443. }
  444. if (set_cond)
  445. set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
  446. else
  447. clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
  448. }
  449. /**
  450. * register_trigger - Generic event_command @reg implementation
  451. * @glob: The raw string used to register the trigger
  452. * @ops: The trigger ops associated with the trigger
  453. * @data: Trigger-specific data to associate with the trigger
  454. * @file: The trace_event_file associated with the event
  455. *
  456. * Common implementation for event trigger registration.
  457. *
  458. * Usually used directly as the @reg method in event command
  459. * implementations.
  460. *
  461. * Return: 0 on success, errno otherwise
  462. */
  463. static int register_trigger(char *glob, struct event_trigger_ops *ops,
  464. struct event_trigger_data *data,
  465. struct trace_event_file *file)
  466. {
  467. struct event_trigger_data *test;
  468. int ret = 0;
  469. lockdep_assert_held(&event_mutex);
  470. list_for_each_entry(test, &file->triggers, list) {
  471. if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) {
  472. ret = -EEXIST;
  473. goto out;
  474. }
  475. }
  476. if (data->ops->init) {
  477. ret = data->ops->init(data->ops, data);
  478. if (ret < 0)
  479. goto out;
  480. }
  481. list_add_rcu(&data->list, &file->triggers);
  482. ret++;
  483. update_cond_flag(file);
  484. if (trace_event_trigger_enable_disable(file, 1) < 0) {
  485. list_del_rcu(&data->list);
  486. update_cond_flag(file);
  487. ret--;
  488. }
  489. out:
  490. return ret;
  491. }
  492. /**
  493. * unregister_trigger - Generic event_command @unreg implementation
  494. * @glob: The raw string used to register the trigger
  495. * @ops: The trigger ops associated with the trigger
  496. * @test: Trigger-specific data used to find the trigger to remove
  497. * @file: The trace_event_file associated with the event
  498. *
  499. * Common implementation for event trigger unregistration.
  500. *
  501. * Usually used directly as the @unreg method in event command
  502. * implementations.
  503. */
  504. static void unregister_trigger(char *glob, struct event_trigger_ops *ops,
  505. struct event_trigger_data *test,
  506. struct trace_event_file *file)
  507. {
  508. struct event_trigger_data *data;
  509. bool unregistered = false;
  510. lockdep_assert_held(&event_mutex);
  511. list_for_each_entry(data, &file->triggers, list) {
  512. if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
  513. unregistered = true;
  514. list_del_rcu(&data->list);
  515. trace_event_trigger_enable_disable(file, 0);
  516. update_cond_flag(file);
  517. break;
  518. }
  519. }
  520. if (unregistered && data->ops->free)
  521. data->ops->free(data->ops, data);
  522. }
  523. /**
  524. * event_trigger_callback - Generic event_command @func implementation
  525. * @cmd_ops: The command ops, used for trigger registration
  526. * @file: The trace_event_file associated with the event
  527. * @glob: The raw string used to register the trigger
  528. * @cmd: The cmd portion of the string used to register the trigger
  529. * @param: The params portion of the string used to register the trigger
  530. *
  531. * Common implementation for event command parsing and trigger
  532. * instantiation.
  533. *
  534. * Usually used directly as the @func method in event command
  535. * implementations.
  536. *
  537. * Return: 0 on success, errno otherwise
  538. */
  539. static int
  540. event_trigger_callback(struct event_command *cmd_ops,
  541. struct trace_event_file *file,
  542. char *glob, char *cmd, char *param)
  543. {
  544. struct event_trigger_data *trigger_data;
  545. struct event_trigger_ops *trigger_ops;
  546. char *trigger = NULL;
  547. char *number;
  548. int ret;
  549. /* separate the trigger from the filter (t:n [if filter]) */
  550. if (param && isdigit(param[0])) {
  551. trigger = strsep(&param, " \t");
  552. if (param) {
  553. param = skip_spaces(param);
  554. if (!*param)
  555. param = NULL;
  556. }
  557. }
  558. trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
  559. ret = -ENOMEM;
  560. trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
  561. if (!trigger_data)
  562. goto out;
  563. trigger_data->count = -1;
  564. trigger_data->ops = trigger_ops;
  565. trigger_data->cmd_ops = cmd_ops;
  566. trigger_data->private_data = file;
  567. INIT_LIST_HEAD(&trigger_data->list);
  568. INIT_LIST_HEAD(&trigger_data->named_list);
  569. if (glob[0] == '!') {
  570. cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
  571. kfree(trigger_data);
  572. ret = 0;
  573. goto out;
  574. }
  575. if (trigger) {
  576. number = strsep(&trigger, ":");
  577. ret = -EINVAL;
  578. if (!strlen(number))
  579. goto out_free;
  580. /*
  581. * We use the callback data field (which is a pointer)
  582. * as our counter.
  583. */
  584. ret = kstrtoul(number, 0, &trigger_data->count);
  585. if (ret)
  586. goto out_free;
  587. }
  588. if (!param) /* if param is non-empty, it's supposed to be a filter */
  589. goto out_reg;
  590. if (!cmd_ops->set_filter)
  591. goto out_reg;
  592. ret = cmd_ops->set_filter(param, trigger_data, file);
  593. if (ret < 0)
  594. goto out_free;
  595. out_reg:
  596. /* Up the trigger_data count to make sure reg doesn't free it on failure */
  597. event_trigger_init(trigger_ops, trigger_data);
  598. ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
  599. /*
  600. * The above returns on success the # of functions enabled,
  601. * but if it didn't find any functions it returns zero.
  602. * Consider no functions a failure too.
  603. */
  604. if (!ret) {
  605. cmd_ops->unreg(glob, trigger_ops, trigger_data, file);
  606. ret = -ENOENT;
  607. } else if (ret > 0)
  608. ret = 0;
  609. /* Down the counter of trigger_data or free it if not used anymore */
  610. event_trigger_free(trigger_ops, trigger_data);
  611. out:
  612. return ret;
  613. out_free:
  614. if (cmd_ops->set_filter)
  615. cmd_ops->set_filter(NULL, trigger_data, NULL);
  616. kfree(trigger_data);
  617. goto out;
  618. }
  619. /**
  620. * set_trigger_filter - Generic event_command @set_filter implementation
  621. * @filter_str: The filter string for the trigger, NULL to remove filter
  622. * @trigger_data: Trigger-specific data
  623. * @file: The trace_event_file associated with the event
  624. *
  625. * Common implementation for event command filter parsing and filter
  626. * instantiation.
  627. *
  628. * Usually used directly as the @set_filter method in event command
  629. * implementations.
  630. *
  631. * Also used to remove a filter (if filter_str = NULL).
  632. *
  633. * Return: 0 on success, errno otherwise
  634. */
  635. int set_trigger_filter(char *filter_str,
  636. struct event_trigger_data *trigger_data,
  637. struct trace_event_file *file)
  638. {
  639. struct event_trigger_data *data = trigger_data;
  640. struct event_filter *filter = NULL, *tmp;
  641. int ret = -EINVAL;
  642. char *s;
  643. if (!filter_str) /* clear the current filter */
  644. goto assign;
  645. s = strsep(&filter_str, " \t");
  646. if (!strlen(s) || strcmp(s, "if") != 0)
  647. goto out;
  648. if (!filter_str)
  649. goto out;
  650. /* The filter is for the 'trigger' event, not the triggered event */
  651. ret = create_event_filter(file->tr, file->event_call,
  652. filter_str, false, &filter);
  653. /*
  654. * If create_event_filter() fails, filter still needs to be freed.
  655. * Which the calling code will do with data->filter.
  656. */
  657. assign:
  658. tmp = rcu_access_pointer(data->filter);
  659. rcu_assign_pointer(data->filter, filter);
  660. if (tmp) {
  661. /* Make sure the call is done with the filter */
  662. tracepoint_synchronize_unregister();
  663. free_event_filter(tmp);
  664. }
  665. kfree(data->filter_str);
  666. data->filter_str = NULL;
  667. if (filter_str) {
  668. data->filter_str = kstrdup(filter_str, GFP_KERNEL);
  669. if (!data->filter_str) {
  670. free_event_filter(rcu_access_pointer(data->filter));
  671. data->filter = NULL;
  672. ret = -ENOMEM;
  673. }
  674. }
  675. out:
  676. return ret;
  677. }
  678. static LIST_HEAD(named_triggers);
  679. /**
  680. * find_named_trigger - Find the common named trigger associated with @name
  681. * @name: The name of the set of named triggers to find the common data for
  682. *
  683. * Named triggers are sets of triggers that share a common set of
  684. * trigger data. The first named trigger registered with a given name
  685. * owns the common trigger data that the others subsequently
  686. * registered with the same name will reference. This function
  687. * returns the common trigger data associated with that first
  688. * registered instance.
  689. *
  690. * Return: the common trigger data for the given named trigger on
  691. * success, NULL otherwise.
  692. */
  693. struct event_trigger_data *find_named_trigger(const char *name)
  694. {
  695. struct event_trigger_data *data;
  696. if (!name)
  697. return NULL;
  698. list_for_each_entry(data, &named_triggers, named_list) {
  699. if (data->named_data)
  700. continue;
  701. if (strcmp(data->name, name) == 0)
  702. return data;
  703. }
  704. return NULL;
  705. }
  706. /**
  707. * is_named_trigger - determine if a given trigger is a named trigger
  708. * @test: The trigger data to test
  709. *
  710. * Return: true if 'test' is a named trigger, false otherwise.
  711. */
  712. bool is_named_trigger(struct event_trigger_data *test)
  713. {
  714. struct event_trigger_data *data;
  715. list_for_each_entry(data, &named_triggers, named_list) {
  716. if (test == data)
  717. return true;
  718. }
  719. return false;
  720. }
  721. /**
  722. * save_named_trigger - save the trigger in the named trigger list
  723. * @name: The name of the named trigger set
  724. * @data: The trigger data to save
  725. *
  726. * Return: 0 if successful, negative error otherwise.
  727. */
  728. int save_named_trigger(const char *name, struct event_trigger_data *data)
  729. {
  730. data->name = kstrdup(name, GFP_KERNEL);
  731. if (!data->name)
  732. return -ENOMEM;
  733. list_add(&data->named_list, &named_triggers);
  734. return 0;
  735. }
  736. /**
  737. * del_named_trigger - delete a trigger from the named trigger list
  738. * @data: The trigger data to delete
  739. */
  740. void del_named_trigger(struct event_trigger_data *data)
  741. {
  742. kfree(data->name);
  743. data->name = NULL;
  744. list_del(&data->named_list);
  745. }
  746. static void __pause_named_trigger(struct event_trigger_data *data, bool pause)
  747. {
  748. struct event_trigger_data *test;
  749. list_for_each_entry(test, &named_triggers, named_list) {
  750. if (strcmp(test->name, data->name) == 0) {
  751. if (pause) {
  752. test->paused_tmp = test->paused;
  753. test->paused = true;
  754. } else {
  755. test->paused = test->paused_tmp;
  756. }
  757. }
  758. }
  759. }
  760. /**
  761. * pause_named_trigger - Pause all named triggers with the same name
  762. * @data: The trigger data of a named trigger to pause
  763. *
  764. * Pauses a named trigger along with all other triggers having the
  765. * same name. Because named triggers share a common set of data,
  766. * pausing only one is meaningless, so pausing one named trigger needs
  767. * to pause all triggers with the same name.
  768. */
  769. void pause_named_trigger(struct event_trigger_data *data)
  770. {
  771. __pause_named_trigger(data, true);
  772. }
  773. /**
  774. * unpause_named_trigger - Un-pause all named triggers with the same name
  775. * @data: The trigger data of a named trigger to unpause
  776. *
  777. * Un-pauses a named trigger along with all other triggers having the
  778. * same name. Because named triggers share a common set of data,
  779. * unpausing only one is meaningless, so unpausing one named trigger
  780. * needs to unpause all triggers with the same name.
  781. */
  782. void unpause_named_trigger(struct event_trigger_data *data)
  783. {
  784. __pause_named_trigger(data, false);
  785. }
  786. /**
  787. * set_named_trigger_data - Associate common named trigger data
  788. * @data: The trigger data of a named trigger to unpause
  789. *
  790. * Named triggers are sets of triggers that share a common set of
  791. * trigger data. The first named trigger registered with a given name
  792. * owns the common trigger data that the others subsequently
  793. * registered with the same name will reference. This function
  794. * associates the common trigger data from the first trigger with the
  795. * given trigger.
  796. */
  797. void set_named_trigger_data(struct event_trigger_data *data,
  798. struct event_trigger_data *named_data)
  799. {
  800. data->named_data = named_data;
  801. }
  802. struct event_trigger_data *
  803. get_named_trigger_data(struct event_trigger_data *data)
  804. {
  805. return data->named_data;
  806. }
  807. static void
  808. traceon_trigger(struct event_trigger_data *data, void *rec,
  809. struct ring_buffer_event *event)
  810. {
  811. struct trace_event_file *file = data->private_data;
  812. if (file) {
  813. if (tracer_tracing_is_on(file->tr))
  814. return;
  815. tracer_tracing_on(file->tr);
  816. return;
  817. }
  818. if (tracing_is_on())
  819. return;
  820. tracing_on();
  821. }
  822. static void
  823. traceon_count_trigger(struct event_trigger_data *data, void *rec,
  824. struct ring_buffer_event *event)
  825. {
  826. struct trace_event_file *file = data->private_data;
  827. if (file) {
  828. if (tracer_tracing_is_on(file->tr))
  829. return;
  830. } else {
  831. if (tracing_is_on())
  832. return;
  833. }
  834. if (!data->count)
  835. return;
  836. if (data->count != -1)
  837. (data->count)--;
  838. if (file)
  839. tracer_tracing_on(file->tr);
  840. else
  841. tracing_on();
  842. }
  843. static void
  844. traceoff_trigger(struct event_trigger_data *data, void *rec,
  845. struct ring_buffer_event *event)
  846. {
  847. struct trace_event_file *file = data->private_data;
  848. if (file) {
  849. if (!tracer_tracing_is_on(file->tr))
  850. return;
  851. tracer_tracing_off(file->tr);
  852. return;
  853. }
  854. if (!tracing_is_on())
  855. return;
  856. tracing_off();
  857. }
  858. static void
  859. traceoff_count_trigger(struct event_trigger_data *data, void *rec,
  860. struct ring_buffer_event *event)
  861. {
  862. struct trace_event_file *file = data->private_data;
  863. if (file) {
  864. if (!tracer_tracing_is_on(file->tr))
  865. return;
  866. } else {
  867. if (!tracing_is_on())
  868. return;
  869. }
  870. if (!data->count)
  871. return;
  872. if (data->count != -1)
  873. (data->count)--;
  874. if (file)
  875. tracer_tracing_off(file->tr);
  876. else
  877. tracing_off();
  878. }
  879. static int
  880. traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
  881. struct event_trigger_data *data)
  882. {
  883. return event_trigger_print("traceon", m, (void *)data->count,
  884. data->filter_str);
  885. }
  886. static int
  887. traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
  888. struct event_trigger_data *data)
  889. {
  890. return event_trigger_print("traceoff", m, (void *)data->count,
  891. data->filter_str);
  892. }
  893. static struct event_trigger_ops traceon_trigger_ops = {
  894. .func = traceon_trigger,
  895. .print = traceon_trigger_print,
  896. .init = event_trigger_init,
  897. .free = event_trigger_free,
  898. };
  899. static struct event_trigger_ops traceon_count_trigger_ops = {
  900. .func = traceon_count_trigger,
  901. .print = traceon_trigger_print,
  902. .init = event_trigger_init,
  903. .free = event_trigger_free,
  904. };
  905. static struct event_trigger_ops traceoff_trigger_ops = {
  906. .func = traceoff_trigger,
  907. .print = traceoff_trigger_print,
  908. .init = event_trigger_init,
  909. .free = event_trigger_free,
  910. };
  911. static struct event_trigger_ops traceoff_count_trigger_ops = {
  912. .func = traceoff_count_trigger,
  913. .print = traceoff_trigger_print,
  914. .init = event_trigger_init,
  915. .free = event_trigger_free,
  916. };
  917. static struct event_trigger_ops *
  918. onoff_get_trigger_ops(char *cmd, char *param)
  919. {
  920. struct event_trigger_ops *ops;
  921. /* we register both traceon and traceoff to this callback */
  922. if (strcmp(cmd, "traceon") == 0)
  923. ops = param ? &traceon_count_trigger_ops :
  924. &traceon_trigger_ops;
  925. else
  926. ops = param ? &traceoff_count_trigger_ops :
  927. &traceoff_trigger_ops;
  928. return ops;
  929. }
  930. static struct event_command trigger_traceon_cmd = {
  931. .name = "traceon",
  932. .trigger_type = ETT_TRACE_ONOFF,
  933. .func = event_trigger_callback,
  934. .reg = register_trigger,
  935. .unreg = unregister_trigger,
  936. .get_trigger_ops = onoff_get_trigger_ops,
  937. .set_filter = set_trigger_filter,
  938. };
  939. static struct event_command trigger_traceoff_cmd = {
  940. .name = "traceoff",
  941. .trigger_type = ETT_TRACE_ONOFF,
  942. .flags = EVENT_CMD_FL_POST_TRIGGER,
  943. .func = event_trigger_callback,
  944. .reg = register_trigger,
  945. .unreg = unregister_trigger,
  946. .get_trigger_ops = onoff_get_trigger_ops,
  947. .set_filter = set_trigger_filter,
  948. };
  949. #ifdef CONFIG_TRACER_SNAPSHOT
  950. static void
  951. snapshot_trigger(struct event_trigger_data *data, void *rec,
  952. struct ring_buffer_event *event)
  953. {
  954. struct trace_event_file *file = data->private_data;
  955. if (file)
  956. tracing_snapshot_instance(file->tr);
  957. else
  958. tracing_snapshot();
  959. }
  960. static void
  961. snapshot_count_trigger(struct event_trigger_data *data, void *rec,
  962. struct ring_buffer_event *event)
  963. {
  964. if (!data->count)
  965. return;
  966. if (data->count != -1)
  967. (data->count)--;
  968. snapshot_trigger(data, rec, event);
  969. }
  970. static int
  971. register_snapshot_trigger(char *glob, struct event_trigger_ops *ops,
  972. struct event_trigger_data *data,
  973. struct trace_event_file *file)
  974. {
  975. if (tracing_alloc_snapshot_instance(file->tr) != 0)
  976. return 0;
  977. return register_trigger(glob, ops, data, file);
  978. }
  979. static int
  980. snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
  981. struct event_trigger_data *data)
  982. {
  983. return event_trigger_print("snapshot", m, (void *)data->count,
  984. data->filter_str);
  985. }
  986. static struct event_trigger_ops snapshot_trigger_ops = {
  987. .func = snapshot_trigger,
  988. .print = snapshot_trigger_print,
  989. .init = event_trigger_init,
  990. .free = event_trigger_free,
  991. };
  992. static struct event_trigger_ops snapshot_count_trigger_ops = {
  993. .func = snapshot_count_trigger,
  994. .print = snapshot_trigger_print,
  995. .init = event_trigger_init,
  996. .free = event_trigger_free,
  997. };
  998. static struct event_trigger_ops *
  999. snapshot_get_trigger_ops(char *cmd, char *param)
  1000. {
  1001. return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
  1002. }
  1003. static struct event_command trigger_snapshot_cmd = {
  1004. .name = "snapshot",
  1005. .trigger_type = ETT_SNAPSHOT,
  1006. .func = event_trigger_callback,
  1007. .reg = register_snapshot_trigger,
  1008. .unreg = unregister_trigger,
  1009. .get_trigger_ops = snapshot_get_trigger_ops,
  1010. .set_filter = set_trigger_filter,
  1011. };
  1012. static __init int register_trigger_snapshot_cmd(void)
  1013. {
  1014. int ret;
  1015. ret = register_event_command(&trigger_snapshot_cmd);
  1016. WARN_ON(ret < 0);
  1017. return ret;
  1018. }
  1019. #else
  1020. static __init int register_trigger_snapshot_cmd(void) { return 0; }
  1021. #endif /* CONFIG_TRACER_SNAPSHOT */
  1022. #ifdef CONFIG_STACKTRACE
  1023. #ifdef CONFIG_UNWINDER_ORC
  1024. /* Skip 2:
  1025. * event_triggers_post_call()
  1026. * trace_event_raw_event_xxx()
  1027. */
  1028. # define STACK_SKIP 2
  1029. #else
  1030. /*
  1031. * Skip 4:
  1032. * stacktrace_trigger()
  1033. * event_triggers_post_call()
  1034. * trace_event_buffer_commit()
  1035. * trace_event_raw_event_xxx()
  1036. */
  1037. #define STACK_SKIP 4
  1038. #endif
  1039. static void
  1040. stacktrace_trigger(struct event_trigger_data *data, void *rec,
  1041. struct ring_buffer_event *event)
  1042. {
  1043. struct trace_event_file *file = data->private_data;
  1044. unsigned long flags;
  1045. if (file) {
  1046. local_save_flags(flags);
  1047. __trace_stack(file->tr, flags, STACK_SKIP, preempt_count());
  1048. } else
  1049. trace_dump_stack(STACK_SKIP);
  1050. }
  1051. static void
  1052. stacktrace_count_trigger(struct event_trigger_data *data, void *rec,
  1053. struct ring_buffer_event *event)
  1054. {
  1055. if (!data->count)
  1056. return;
  1057. if (data->count != -1)
  1058. (data->count)--;
  1059. stacktrace_trigger(data, rec, event);
  1060. }
  1061. static int
  1062. stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
  1063. struct event_trigger_data *data)
  1064. {
  1065. return event_trigger_print("stacktrace", m, (void *)data->count,
  1066. data->filter_str);
  1067. }
  1068. static struct event_trigger_ops stacktrace_trigger_ops = {
  1069. .func = stacktrace_trigger,
  1070. .print = stacktrace_trigger_print,
  1071. .init = event_trigger_init,
  1072. .free = event_trigger_free,
  1073. };
  1074. static struct event_trigger_ops stacktrace_count_trigger_ops = {
  1075. .func = stacktrace_count_trigger,
  1076. .print = stacktrace_trigger_print,
  1077. .init = event_trigger_init,
  1078. .free = event_trigger_free,
  1079. };
  1080. static struct event_trigger_ops *
  1081. stacktrace_get_trigger_ops(char *cmd, char *param)
  1082. {
  1083. return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
  1084. }
  1085. static struct event_command trigger_stacktrace_cmd = {
  1086. .name = "stacktrace",
  1087. .trigger_type = ETT_STACKTRACE,
  1088. .flags = EVENT_CMD_FL_POST_TRIGGER,
  1089. .func = event_trigger_callback,
  1090. .reg = register_trigger,
  1091. .unreg = unregister_trigger,
  1092. .get_trigger_ops = stacktrace_get_trigger_ops,
  1093. .set_filter = set_trigger_filter,
  1094. };
  1095. static __init int register_trigger_stacktrace_cmd(void)
  1096. {
  1097. int ret;
  1098. ret = register_event_command(&trigger_stacktrace_cmd);
  1099. WARN_ON(ret < 0);
  1100. return ret;
  1101. }
  1102. #else
  1103. static __init int register_trigger_stacktrace_cmd(void) { return 0; }
  1104. #endif /* CONFIG_STACKTRACE */
  1105. static __init void unregister_trigger_traceon_traceoff_cmds(void)
  1106. {
  1107. unregister_event_command(&trigger_traceon_cmd);
  1108. unregister_event_command(&trigger_traceoff_cmd);
  1109. }
  1110. static void
  1111. event_enable_trigger(struct event_trigger_data *data, void *rec,
  1112. struct ring_buffer_event *event)
  1113. {
  1114. struct enable_trigger_data *enable_data = data->private_data;
  1115. if (enable_data->enable)
  1116. clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
  1117. else
  1118. set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
  1119. }
  1120. static void
  1121. event_enable_count_trigger(struct event_trigger_data *data, void *rec,
  1122. struct ring_buffer_event *event)
  1123. {
  1124. struct enable_trigger_data *enable_data = data->private_data;
  1125. if (!data->count)
  1126. return;
  1127. /* Skip if the event is in a state we want to switch to */
  1128. if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
  1129. return;
  1130. if (data->count != -1)
  1131. (data->count)--;
  1132. event_enable_trigger(data, rec, event);
  1133. }
  1134. int event_enable_trigger_print(struct seq_file *m,
  1135. struct event_trigger_ops *ops,
  1136. struct event_trigger_data *data)
  1137. {
  1138. struct enable_trigger_data *enable_data = data->private_data;
  1139. seq_printf(m, "%s:%s:%s",
  1140. enable_data->hist ?
  1141. (enable_data->enable ? ENABLE_HIST_STR : DISABLE_HIST_STR) :
  1142. (enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR),
  1143. enable_data->file->event_call->class->system,
  1144. trace_event_name(enable_data->file->event_call));
  1145. if (data->count == -1)
  1146. seq_puts(m, ":unlimited");
  1147. else
  1148. seq_printf(m, ":count=%ld", data->count);
  1149. if (data->filter_str)
  1150. seq_printf(m, " if %s\n", data->filter_str);
  1151. else
  1152. seq_putc(m, '\n');
  1153. return 0;
  1154. }
  1155. void event_enable_trigger_free(struct event_trigger_ops *ops,
  1156. struct event_trigger_data *data)
  1157. {
  1158. struct enable_trigger_data *enable_data = data->private_data;
  1159. if (WARN_ON_ONCE(data->ref <= 0))
  1160. return;
  1161. data->ref--;
  1162. if (!data->ref) {
  1163. /* Remove the SOFT_MODE flag */
  1164. trace_event_enable_disable(enable_data->file, 0, 1);
  1165. module_put(enable_data->file->event_call->mod);
  1166. trigger_data_free(data);
  1167. kfree(enable_data);
  1168. }
  1169. }
  1170. static struct event_trigger_ops event_enable_trigger_ops = {
  1171. .func = event_enable_trigger,
  1172. .print = event_enable_trigger_print,
  1173. .init = event_trigger_init,
  1174. .free = event_enable_trigger_free,
  1175. };
  1176. static struct event_trigger_ops event_enable_count_trigger_ops = {
  1177. .func = event_enable_count_trigger,
  1178. .print = event_enable_trigger_print,
  1179. .init = event_trigger_init,
  1180. .free = event_enable_trigger_free,
  1181. };
  1182. static struct event_trigger_ops event_disable_trigger_ops = {
  1183. .func = event_enable_trigger,
  1184. .print = event_enable_trigger_print,
  1185. .init = event_trigger_init,
  1186. .free = event_enable_trigger_free,
  1187. };
  1188. static struct event_trigger_ops event_disable_count_trigger_ops = {
  1189. .func = event_enable_count_trigger,
  1190. .print = event_enable_trigger_print,
  1191. .init = event_trigger_init,
  1192. .free = event_enable_trigger_free,
  1193. };
  1194. int event_enable_trigger_func(struct event_command *cmd_ops,
  1195. struct trace_event_file *file,
  1196. char *glob, char *cmd, char *param)
  1197. {
  1198. struct trace_event_file *event_enable_file;
  1199. struct enable_trigger_data *enable_data;
  1200. struct event_trigger_data *trigger_data;
  1201. struct event_trigger_ops *trigger_ops;
  1202. struct trace_array *tr = file->tr;
  1203. const char *system;
  1204. const char *event;
  1205. bool hist = false;
  1206. char *trigger;
  1207. char *number;
  1208. bool enable;
  1209. int ret;
  1210. if (!param)
  1211. return -EINVAL;
  1212. /* separate the trigger from the filter (s:e:n [if filter]) */
  1213. trigger = strsep(&param, " \t");
  1214. if (!trigger)
  1215. return -EINVAL;
  1216. if (param) {
  1217. param = skip_spaces(param);
  1218. if (!*param)
  1219. param = NULL;
  1220. }
  1221. system = strsep(&trigger, ":");
  1222. if (!trigger)
  1223. return -EINVAL;
  1224. event = strsep(&trigger, ":");
  1225. ret = -EINVAL;
  1226. event_enable_file = find_event_file(tr, system, event);
  1227. if (!event_enable_file)
  1228. goto out;
  1229. #ifdef CONFIG_HIST_TRIGGERS
  1230. hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) ||
  1231. (strcmp(cmd, DISABLE_HIST_STR) == 0));
  1232. enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
  1233. (strcmp(cmd, ENABLE_HIST_STR) == 0));
  1234. #else
  1235. enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
  1236. #endif
  1237. trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
  1238. ret = -ENOMEM;
  1239. trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
  1240. if (!trigger_data)
  1241. goto out;
  1242. enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
  1243. if (!enable_data) {
  1244. kfree(trigger_data);
  1245. goto out;
  1246. }
  1247. trigger_data->count = -1;
  1248. trigger_data->ops = trigger_ops;
  1249. trigger_data->cmd_ops = cmd_ops;
  1250. INIT_LIST_HEAD(&trigger_data->list);
  1251. RCU_INIT_POINTER(trigger_data->filter, NULL);
  1252. enable_data->hist = hist;
  1253. enable_data->enable = enable;
  1254. enable_data->file = event_enable_file;
  1255. trigger_data->private_data = enable_data;
  1256. if (glob[0] == '!') {
  1257. cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
  1258. kfree(trigger_data);
  1259. kfree(enable_data);
  1260. ret = 0;
  1261. goto out;
  1262. }
  1263. /* Up the trigger_data count to make sure nothing frees it on failure */
  1264. event_trigger_init(trigger_ops, trigger_data);
  1265. if (trigger) {
  1266. number = strsep(&trigger, ":");
  1267. ret = -EINVAL;
  1268. if (!strlen(number))
  1269. goto out_free;
  1270. /*
  1271. * We use the callback data field (which is a pointer)
  1272. * as our counter.
  1273. */
  1274. ret = kstrtoul(number, 0, &trigger_data->count);
  1275. if (ret)
  1276. goto out_free;
  1277. }
  1278. if (!param) /* if param is non-empty, it's supposed to be a filter */
  1279. goto out_reg;
  1280. if (!cmd_ops->set_filter)
  1281. goto out_reg;
  1282. ret = cmd_ops->set_filter(param, trigger_data, file);
  1283. if (ret < 0)
  1284. goto out_free;
  1285. out_reg:
  1286. /* Don't let event modules unload while probe registered */
  1287. ret = try_module_get(event_enable_file->event_call->mod);
  1288. if (!ret) {
  1289. ret = -EBUSY;
  1290. goto out_free;
  1291. }
  1292. ret = trace_event_enable_disable(event_enable_file, 1, 1);
  1293. if (ret < 0)
  1294. goto out_put;
  1295. ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
  1296. /*
  1297. * The above returns on success the # of functions enabled,
  1298. * but if it didn't find any functions it returns zero.
  1299. * Consider no functions a failure too.
  1300. */
  1301. if (!ret) {
  1302. ret = -ENOENT;
  1303. goto out_disable;
  1304. } else if (ret < 0)
  1305. goto out_disable;
  1306. /* Just return zero, not the number of enabled functions */
  1307. ret = 0;
  1308. event_trigger_free(trigger_ops, trigger_data);
  1309. out:
  1310. return ret;
  1311. out_disable:
  1312. trace_event_enable_disable(event_enable_file, 0, 1);
  1313. out_put:
  1314. module_put(event_enable_file->event_call->mod);
  1315. out_free:
  1316. if (cmd_ops->set_filter)
  1317. cmd_ops->set_filter(NULL, trigger_data, NULL);
  1318. event_trigger_free(trigger_ops, trigger_data);
  1319. kfree(enable_data);
  1320. goto out;
  1321. }
  1322. int event_enable_register_trigger(char *glob,
  1323. struct event_trigger_ops *ops,
  1324. struct event_trigger_data *data,
  1325. struct trace_event_file *file)
  1326. {
  1327. struct enable_trigger_data *enable_data = data->private_data;
  1328. struct enable_trigger_data *test_enable_data;
  1329. struct event_trigger_data *test;
  1330. int ret = 0;
  1331. lockdep_assert_held(&event_mutex);
  1332. list_for_each_entry(test, &file->triggers, list) {
  1333. test_enable_data = test->private_data;
  1334. if (test_enable_data &&
  1335. (test->cmd_ops->trigger_type ==
  1336. data->cmd_ops->trigger_type) &&
  1337. (test_enable_data->file == enable_data->file)) {
  1338. ret = -EEXIST;
  1339. goto out;
  1340. }
  1341. }
  1342. if (data->ops->init) {
  1343. ret = data->ops->init(data->ops, data);
  1344. if (ret < 0)
  1345. goto out;
  1346. }
  1347. list_add_rcu(&data->list, &file->triggers);
  1348. ret++;
  1349. update_cond_flag(file);
  1350. if (trace_event_trigger_enable_disable(file, 1) < 0) {
  1351. list_del_rcu(&data->list);
  1352. update_cond_flag(file);
  1353. ret--;
  1354. }
  1355. out:
  1356. return ret;
  1357. }
  1358. void event_enable_unregister_trigger(char *glob,
  1359. struct event_trigger_ops *ops,
  1360. struct event_trigger_data *test,
  1361. struct trace_event_file *file)
  1362. {
  1363. struct enable_trigger_data *test_enable_data = test->private_data;
  1364. struct enable_trigger_data *enable_data;
  1365. struct event_trigger_data *data;
  1366. bool unregistered = false;
  1367. lockdep_assert_held(&event_mutex);
  1368. list_for_each_entry(data, &file->triggers, list) {
  1369. enable_data = data->private_data;
  1370. if (enable_data &&
  1371. (data->cmd_ops->trigger_type ==
  1372. test->cmd_ops->trigger_type) &&
  1373. (enable_data->file == test_enable_data->file)) {
  1374. unregistered = true;
  1375. list_del_rcu(&data->list);
  1376. trace_event_trigger_enable_disable(file, 0);
  1377. update_cond_flag(file);
  1378. break;
  1379. }
  1380. }
  1381. if (unregistered && data->ops->free)
  1382. data->ops->free(data->ops, data);
  1383. }
  1384. static struct event_trigger_ops *
  1385. event_enable_get_trigger_ops(char *cmd, char *param)
  1386. {
  1387. struct event_trigger_ops *ops;
  1388. bool enable;
  1389. #ifdef CONFIG_HIST_TRIGGERS
  1390. enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
  1391. (strcmp(cmd, ENABLE_HIST_STR) == 0));
  1392. #else
  1393. enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
  1394. #endif
  1395. if (enable)
  1396. ops = param ? &event_enable_count_trigger_ops :
  1397. &event_enable_trigger_ops;
  1398. else
  1399. ops = param ? &event_disable_count_trigger_ops :
  1400. &event_disable_trigger_ops;
  1401. return ops;
  1402. }
  1403. static struct event_command trigger_enable_cmd = {
  1404. .name = ENABLE_EVENT_STR,
  1405. .trigger_type = ETT_EVENT_ENABLE,
  1406. .func = event_enable_trigger_func,
  1407. .reg = event_enable_register_trigger,
  1408. .unreg = event_enable_unregister_trigger,
  1409. .get_trigger_ops = event_enable_get_trigger_ops,
  1410. .set_filter = set_trigger_filter,
  1411. };
  1412. static struct event_command trigger_disable_cmd = {
  1413. .name = DISABLE_EVENT_STR,
  1414. .trigger_type = ETT_EVENT_ENABLE,
  1415. .func = event_enable_trigger_func,
  1416. .reg = event_enable_register_trigger,
  1417. .unreg = event_enable_unregister_trigger,
  1418. .get_trigger_ops = event_enable_get_trigger_ops,
  1419. .set_filter = set_trigger_filter,
  1420. };
  1421. static __init void unregister_trigger_enable_disable_cmds(void)
  1422. {
  1423. unregister_event_command(&trigger_enable_cmd);
  1424. unregister_event_command(&trigger_disable_cmd);
  1425. }
  1426. static __init int register_trigger_enable_disable_cmds(void)
  1427. {
  1428. int ret;
  1429. ret = register_event_command(&trigger_enable_cmd);
  1430. if (WARN_ON(ret < 0))
  1431. return ret;
  1432. ret = register_event_command(&trigger_disable_cmd);
  1433. if (WARN_ON(ret < 0))
  1434. unregister_trigger_enable_disable_cmds();
  1435. return ret;
  1436. }
  1437. static __init int register_trigger_traceon_traceoff_cmds(void)
  1438. {
  1439. int ret;
  1440. ret = register_event_command(&trigger_traceon_cmd);
  1441. if (WARN_ON(ret < 0))
  1442. return ret;
  1443. ret = register_event_command(&trigger_traceoff_cmd);
  1444. if (WARN_ON(ret < 0))
  1445. unregister_trigger_traceon_traceoff_cmds();
  1446. return ret;
  1447. }
  1448. __init int register_trigger_cmds(void)
  1449. {
  1450. register_trigger_traceon_traceoff_cmds();
  1451. register_trigger_snapshot_cmd();
  1452. register_trigger_stacktrace_cmd();
  1453. register_trigger_enable_disable_cmds();
  1454. register_trigger_hist_enable_disable_cmds();
  1455. register_trigger_hist_cmd();
  1456. return 0;
  1457. }