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Fix: memory leaks on event destroy
[lttng-modules.git] / src / lttng-events.c
1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
2 *
3 * lttng-events.c
4 *
5 * Holds LTTng per-session event registry.
6 *
7 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 */
9
10 /*
11 * This page_alloc.h wrapper needs to be included before gfpflags.h because it
12 * overrides a function with a define.
13 */
14 #include "wrapper/page_alloc.h"
15
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/jiffies.h>
21 #include <linux/utsname.h>
22 #include <linux/err.h>
23 #include <linux/seq_file.h>
24 #include <linux/file.h>
25 #include <linux/anon_inodes.h>
26 #include <wrapper/file.h>
27 #include <linux/uaccess.h>
28 #include <linux/vmalloc.h>
29 #include <linux/dmi.h>
30
31 #include <wrapper/uuid.h>
32 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_mappings() */
33 #include <wrapper/random.h>
34 #include <wrapper/tracepoint.h>
35 #include <wrapper/list.h>
36 #include <wrapper/types.h>
37 #include <lttng/kernel-version.h>
38 #include <lttng/events.h>
39 #include <lttng/lttng-bytecode.h>
40 #include <lttng/tracer.h>
41 #include <lttng/event-notifier-notification.h>
42 #include <lttng/abi-old.h>
43 #include <lttng/endian.h>
44 #include <lttng/string-utils.h>
45 #include <lttng/utils.h>
46 #include <ringbuffer/backend.h>
47 #include <ringbuffer/frontend.h>
48 #include <wrapper/time.h>
49
50 #define METADATA_CACHE_DEFAULT_SIZE 4096
51
52 static LIST_HEAD(sessions);
53 static LIST_HEAD(event_notifier_groups);
54 static LIST_HEAD(lttng_transport_list);
55 static LIST_HEAD(lttng_counter_transport_list);
56 /*
57 * Protect the sessions and metadata caches.
58 */
59 static DEFINE_MUTEX(sessions_mutex);
60 static struct kmem_cache *event_cache;
61 static struct kmem_cache *event_notifier_cache;
62
63 static void lttng_session_lazy_sync_event_enablers(struct lttng_session *session);
64 static void lttng_session_sync_event_enablers(struct lttng_session *session);
65 static void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler);
66 static void lttng_event_notifier_enabler_destroy(struct lttng_event_notifier_enabler *event_notifier_enabler);
67 static void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group);
68
69 static void _lttng_event_destroy(struct lttng_event *event);
70 static void _lttng_event_notifier_destroy(struct lttng_event_notifier *event_notifier);
71 static void _lttng_channel_destroy(struct lttng_channel *chan);
72 static int _lttng_event_unregister(struct lttng_event *event);
73 static int _lttng_event_notifier_unregister(struct lttng_event_notifier *event_notifier);
74 static
75 int _lttng_event_metadata_statedump(struct lttng_session *session,
76 struct lttng_channel *chan,
77 struct lttng_event *event);
78 static
79 int _lttng_session_metadata_statedump(struct lttng_session *session);
80 static
81 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
82 static
83 int _lttng_type_statedump(struct lttng_session *session,
84 const struct lttng_type *type,
85 size_t nesting);
86 static
87 int _lttng_field_statedump(struct lttng_session *session,
88 const struct lttng_event_field *field,
89 size_t nesting);
90
91 void synchronize_trace(void)
92 {
93 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,1,0))
94 synchronize_rcu();
95 #else
96 synchronize_sched();
97 #endif
98
99 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0))
100 #ifdef CONFIG_PREEMPT_RT_FULL
101 synchronize_rcu();
102 #endif
103 #else /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
104 #ifdef CONFIG_PREEMPT_RT
105 synchronize_rcu();
106 #endif
107 #endif /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
108 }
109
110 void lttng_lock_sessions(void)
111 {
112 mutex_lock(&sessions_mutex);
113 }
114
115 void lttng_unlock_sessions(void)
116 {
117 mutex_unlock(&sessions_mutex);
118 }
119
120 static struct lttng_transport *lttng_transport_find(const char *name)
121 {
122 struct lttng_transport *transport;
123
124 list_for_each_entry(transport, &lttng_transport_list, node) {
125 if (!strcmp(transport->name, name))
126 return transport;
127 }
128 return NULL;
129 }
130
131 /*
132 * Called with sessions lock held.
133 */
134 int lttng_session_active(void)
135 {
136 struct lttng_session *iter;
137
138 list_for_each_entry(iter, &sessions, list) {
139 if (iter->active)
140 return 1;
141 }
142 return 0;
143 }
144
145 struct lttng_session *lttng_session_create(void)
146 {
147 struct lttng_session *session;
148 struct lttng_metadata_cache *metadata_cache;
149 int i;
150
151 mutex_lock(&sessions_mutex);
152 session = lttng_kvzalloc(sizeof(struct lttng_session), GFP_KERNEL);
153 if (!session)
154 goto err;
155 INIT_LIST_HEAD(&session->chan);
156 INIT_LIST_HEAD(&session->events);
157 lttng_guid_gen(&session->uuid);
158
159 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
160 GFP_KERNEL);
161 if (!metadata_cache)
162 goto err_free_session;
163 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
164 if (!metadata_cache->data)
165 goto err_free_cache;
166 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
167 kref_init(&metadata_cache->refcount);
168 mutex_init(&metadata_cache->lock);
169 session->metadata_cache = metadata_cache;
170 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
171 memcpy(&metadata_cache->uuid, &session->uuid,
172 sizeof(metadata_cache->uuid));
173 INIT_LIST_HEAD(&session->enablers_head);
174 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
175 INIT_HLIST_HEAD(&session->events_ht.table[i]);
176 list_add(&session->list, &sessions);
177 session->pid_tracker.session = session;
178 session->pid_tracker.tracker_type = TRACKER_PID;
179 session->vpid_tracker.session = session;
180 session->vpid_tracker.tracker_type = TRACKER_VPID;
181 session->uid_tracker.session = session;
182 session->uid_tracker.tracker_type = TRACKER_UID;
183 session->vuid_tracker.session = session;
184 session->vuid_tracker.tracker_type = TRACKER_VUID;
185 session->gid_tracker.session = session;
186 session->gid_tracker.tracker_type = TRACKER_GID;
187 session->vgid_tracker.session = session;
188 session->vgid_tracker.tracker_type = TRACKER_VGID;
189 mutex_unlock(&sessions_mutex);
190 return session;
191
192 err_free_cache:
193 kfree(metadata_cache);
194 err_free_session:
195 lttng_kvfree(session);
196 err:
197 mutex_unlock(&sessions_mutex);
198 return NULL;
199 }
200
201 static
202 struct lttng_counter_transport *lttng_counter_transport_find(const char *name)
203 {
204 struct lttng_counter_transport *transport;
205
206 list_for_each_entry(transport, &lttng_counter_transport_list, node) {
207 if (!strcmp(transport->name, name))
208 return transport;
209 }
210 return NULL;
211 }
212
213 struct lttng_counter *lttng_kernel_counter_create(
214 const char *counter_transport_name,
215 size_t number_dimensions, const size_t *dimensions_sizes)
216 {
217 struct lttng_counter *counter = NULL;
218 struct lttng_counter_transport *counter_transport = NULL;
219
220 counter_transport = lttng_counter_transport_find(counter_transport_name);
221 if (!counter_transport) {
222 printk(KERN_WARNING "LTTng: counter transport %s not found.\n",
223 counter_transport_name);
224 goto notransport;
225 }
226 if (!try_module_get(counter_transport->owner)) {
227 printk(KERN_WARNING "LTTng: Can't lock counter transport module.\n");
228 goto notransport;
229 }
230
231 counter = lttng_kvzalloc(sizeof(struct lttng_counter), GFP_KERNEL);
232 if (!counter)
233 goto nomem;
234
235 /* Create event notifier error counter. */
236 counter->ops = &counter_transport->ops;
237 counter->transport = counter_transport;
238
239 counter->counter = counter->ops->counter_create(
240 number_dimensions, dimensions_sizes, 0);
241 if (!counter->counter) {
242 goto create_error;
243 }
244
245 return counter;
246
247 create_error:
248 lttng_kvfree(counter);
249 nomem:
250 if (counter_transport)
251 module_put(counter_transport->owner);
252 notransport:
253 return NULL;
254 }
255
256 struct lttng_event_notifier_group *lttng_event_notifier_group_create(void)
257 {
258 struct lttng_transport *transport = NULL;
259 struct lttng_event_notifier_group *event_notifier_group;
260 const char *transport_name = "relay-event-notifier";
261 size_t subbuf_size = 4096; //TODO
262 size_t num_subbuf = 16; //TODO
263 unsigned int switch_timer_interval = 0;
264 unsigned int read_timer_interval = 0;
265 int i;
266
267 mutex_lock(&sessions_mutex);
268
269 transport = lttng_transport_find(transport_name);
270 if (!transport) {
271 printk(KERN_WARNING "LTTng: transport %s not found\n",
272 transport_name);
273 goto notransport;
274 }
275 if (!try_module_get(transport->owner)) {
276 printk(KERN_WARNING "LTTng: Can't lock transport %s module.\n",
277 transport_name);
278 goto notransport;
279 }
280
281 event_notifier_group = lttng_kvzalloc(sizeof(struct lttng_event_notifier_group),
282 GFP_KERNEL);
283 if (!event_notifier_group)
284 goto nomem;
285
286 /*
287 * Initialize the ring buffer used to store event notifier
288 * notifications.
289 */
290 event_notifier_group->ops = &transport->ops;
291 event_notifier_group->chan = transport->ops.channel_create(
292 transport_name, event_notifier_group, NULL,
293 subbuf_size, num_subbuf, switch_timer_interval,
294 read_timer_interval);
295 if (!event_notifier_group->chan)
296 goto create_error;
297
298 event_notifier_group->transport = transport;
299
300 INIT_LIST_HEAD(&event_notifier_group->enablers_head);
301 INIT_LIST_HEAD(&event_notifier_group->event_notifiers_head);
302 for (i = 0; i < LTTNG_EVENT_NOTIFIER_HT_SIZE; i++)
303 INIT_HLIST_HEAD(&event_notifier_group->event_notifiers_ht.table[i]);
304
305 list_add(&event_notifier_group->node, &event_notifier_groups);
306
307 mutex_unlock(&sessions_mutex);
308
309 return event_notifier_group;
310
311 create_error:
312 lttng_kvfree(event_notifier_group);
313 nomem:
314 if (transport)
315 module_put(transport->owner);
316 notransport:
317 mutex_unlock(&sessions_mutex);
318 return NULL;
319 }
320
321 void metadata_cache_destroy(struct kref *kref)
322 {
323 struct lttng_metadata_cache *cache =
324 container_of(kref, struct lttng_metadata_cache, refcount);
325 vfree(cache->data);
326 kfree(cache);
327 }
328
329 void lttng_session_destroy(struct lttng_session *session)
330 {
331 struct lttng_channel *chan, *tmpchan;
332 struct lttng_event *event, *tmpevent;
333 struct lttng_metadata_stream *metadata_stream;
334 struct lttng_event_enabler *event_enabler, *tmp_event_enabler;
335 int ret;
336
337 mutex_lock(&sessions_mutex);
338 WRITE_ONCE(session->active, 0);
339 list_for_each_entry(chan, &session->chan, list) {
340 ret = lttng_syscalls_unregister_channel(chan);
341 WARN_ON(ret);
342 }
343 list_for_each_entry(event, &session->events, list) {
344 ret = _lttng_event_unregister(event);
345 WARN_ON(ret);
346 }
347 synchronize_trace(); /* Wait for in-flight events to complete */
348 list_for_each_entry(chan, &session->chan, list) {
349 ret = lttng_syscalls_destroy_event(chan);
350 WARN_ON(ret);
351 }
352 list_for_each_entry_safe(event_enabler, tmp_event_enabler,
353 &session->enablers_head, node)
354 lttng_event_enabler_destroy(event_enabler);
355 list_for_each_entry_safe(event, tmpevent, &session->events, list)
356 _lttng_event_destroy(event);
357 list_for_each_entry_safe(chan, tmpchan, &session->chan, list) {
358 BUG_ON(chan->channel_type == METADATA_CHANNEL);
359 _lttng_channel_destroy(chan);
360 }
361 mutex_lock(&session->metadata_cache->lock);
362 list_for_each_entry(metadata_stream, &session->metadata_cache->metadata_stream, list)
363 _lttng_metadata_channel_hangup(metadata_stream);
364 mutex_unlock(&session->metadata_cache->lock);
365 lttng_id_tracker_destroy(&session->pid_tracker, false);
366 lttng_id_tracker_destroy(&session->vpid_tracker, false);
367 lttng_id_tracker_destroy(&session->uid_tracker, false);
368 lttng_id_tracker_destroy(&session->vuid_tracker, false);
369 lttng_id_tracker_destroy(&session->gid_tracker, false);
370 lttng_id_tracker_destroy(&session->vgid_tracker, false);
371 kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
372 list_del(&session->list);
373 mutex_unlock(&sessions_mutex);
374 lttng_kvfree(session);
375 }
376
377 void lttng_event_notifier_group_destroy(
378 struct lttng_event_notifier_group *event_notifier_group)
379 {
380 struct lttng_event_notifier_enabler *event_notifier_enabler, *tmp_event_notifier_enabler;
381 struct lttng_event_notifier *event_notifier, *tmpevent_notifier;
382 int ret;
383
384 if (!event_notifier_group)
385 return;
386
387 mutex_lock(&sessions_mutex);
388
389 ret = lttng_syscalls_unregister_event_notifier_group(event_notifier_group);
390 WARN_ON(ret);
391
392 list_for_each_entry_safe(event_notifier, tmpevent_notifier,
393 &event_notifier_group->event_notifiers_head, list) {
394 ret = _lttng_event_notifier_unregister(event_notifier);
395 WARN_ON(ret);
396 }
397
398 /* Wait for in-flight event notifier to complete */
399 synchronize_trace();
400
401 irq_work_sync(&event_notifier_group->wakeup_pending);
402
403 kfree(event_notifier_group->sc_filter);
404
405 list_for_each_entry_safe(event_notifier_enabler, tmp_event_notifier_enabler,
406 &event_notifier_group->enablers_head, node)
407 lttng_event_notifier_enabler_destroy(event_notifier_enabler);
408
409 list_for_each_entry_safe(event_notifier, tmpevent_notifier,
410 &event_notifier_group->event_notifiers_head, list)
411 _lttng_event_notifier_destroy(event_notifier);
412
413 if (event_notifier_group->error_counter) {
414 struct lttng_counter *error_counter = event_notifier_group->error_counter;
415
416 error_counter->ops->counter_destroy(error_counter->counter);
417 module_put(error_counter->transport->owner);
418 lttng_kvfree(error_counter);
419 event_notifier_group->error_counter = NULL;
420 }
421
422 event_notifier_group->ops->channel_destroy(event_notifier_group->chan);
423 module_put(event_notifier_group->transport->owner);
424 list_del(&event_notifier_group->node);
425
426 mutex_unlock(&sessions_mutex);
427 lttng_kvfree(event_notifier_group);
428 }
429
430 int lttng_session_statedump(struct lttng_session *session)
431 {
432 int ret;
433
434 mutex_lock(&sessions_mutex);
435 ret = lttng_statedump_start(session);
436 mutex_unlock(&sessions_mutex);
437 return ret;
438 }
439
440 int lttng_session_enable(struct lttng_session *session)
441 {
442 int ret = 0;
443 struct lttng_channel *chan;
444
445 mutex_lock(&sessions_mutex);
446 if (session->active) {
447 ret = -EBUSY;
448 goto end;
449 }
450
451 /* Set transient enabler state to "enabled" */
452 session->tstate = 1;
453
454 /* We need to sync enablers with session before activation. */
455 lttng_session_sync_event_enablers(session);
456
457 /*
458 * Snapshot the number of events per channel to know the type of header
459 * we need to use.
460 */
461 list_for_each_entry(chan, &session->chan, list) {
462 if (chan->header_type)
463 continue; /* don't change it if session stop/restart */
464 if (chan->free_event_id < 31)
465 chan->header_type = 1; /* compact */
466 else
467 chan->header_type = 2; /* large */
468 }
469
470 /* Clear each stream's quiescent state. */
471 list_for_each_entry(chan, &session->chan, list) {
472 if (chan->channel_type != METADATA_CHANNEL)
473 lib_ring_buffer_clear_quiescent_channel(chan->chan);
474 }
475
476 WRITE_ONCE(session->active, 1);
477 WRITE_ONCE(session->been_active, 1);
478 ret = _lttng_session_metadata_statedump(session);
479 if (ret) {
480 WRITE_ONCE(session->active, 0);
481 goto end;
482 }
483 ret = lttng_statedump_start(session);
484 if (ret)
485 WRITE_ONCE(session->active, 0);
486 end:
487 mutex_unlock(&sessions_mutex);
488 return ret;
489 }
490
491 int lttng_session_disable(struct lttng_session *session)
492 {
493 int ret = 0;
494 struct lttng_channel *chan;
495
496 mutex_lock(&sessions_mutex);
497 if (!session->active) {
498 ret = -EBUSY;
499 goto end;
500 }
501 WRITE_ONCE(session->active, 0);
502
503 /* Set transient enabler state to "disabled" */
504 session->tstate = 0;
505 lttng_session_sync_event_enablers(session);
506
507 /* Set each stream's quiescent state. */
508 list_for_each_entry(chan, &session->chan, list) {
509 if (chan->channel_type != METADATA_CHANNEL)
510 lib_ring_buffer_set_quiescent_channel(chan->chan);
511 }
512 end:
513 mutex_unlock(&sessions_mutex);
514 return ret;
515 }
516
517 int lttng_session_metadata_regenerate(struct lttng_session *session)
518 {
519 int ret = 0;
520 struct lttng_channel *chan;
521 struct lttng_event *event;
522 struct lttng_metadata_cache *cache = session->metadata_cache;
523 struct lttng_metadata_stream *stream;
524
525 mutex_lock(&sessions_mutex);
526 if (!session->active) {
527 ret = -EBUSY;
528 goto end;
529 }
530
531 mutex_lock(&cache->lock);
532 memset(cache->data, 0, cache->cache_alloc);
533 cache->metadata_written = 0;
534 cache->version++;
535 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list) {
536 stream->metadata_out = 0;
537 stream->metadata_in = 0;
538 }
539 mutex_unlock(&cache->lock);
540
541 session->metadata_dumped = 0;
542 list_for_each_entry(chan, &session->chan, list) {
543 chan->metadata_dumped = 0;
544 }
545
546 list_for_each_entry(event, &session->events, list) {
547 event->metadata_dumped = 0;
548 }
549
550 ret = _lttng_session_metadata_statedump(session);
551
552 end:
553 mutex_unlock(&sessions_mutex);
554 return ret;
555 }
556
557 int lttng_channel_enable(struct lttng_channel *channel)
558 {
559 int ret = 0;
560
561 mutex_lock(&sessions_mutex);
562 if (channel->channel_type == METADATA_CHANNEL) {
563 ret = -EPERM;
564 goto end;
565 }
566 if (channel->enabled) {
567 ret = -EEXIST;
568 goto end;
569 }
570 /* Set transient enabler state to "enabled" */
571 channel->tstate = 1;
572 lttng_session_sync_event_enablers(channel->session);
573 /* Set atomically the state to "enabled" */
574 WRITE_ONCE(channel->enabled, 1);
575 end:
576 mutex_unlock(&sessions_mutex);
577 return ret;
578 }
579
580 int lttng_channel_disable(struct lttng_channel *channel)
581 {
582 int ret = 0;
583
584 mutex_lock(&sessions_mutex);
585 if (channel->channel_type == METADATA_CHANNEL) {
586 ret = -EPERM;
587 goto end;
588 }
589 if (!channel->enabled) {
590 ret = -EEXIST;
591 goto end;
592 }
593 /* Set atomically the state to "disabled" */
594 WRITE_ONCE(channel->enabled, 0);
595 /* Set transient enabler state to "enabled" */
596 channel->tstate = 0;
597 lttng_session_sync_event_enablers(channel->session);
598 end:
599 mutex_unlock(&sessions_mutex);
600 return ret;
601 }
602
603 int lttng_event_enable(struct lttng_event *event)
604 {
605 int ret = 0;
606
607 mutex_lock(&sessions_mutex);
608 if (event->chan->channel_type == METADATA_CHANNEL) {
609 ret = -EPERM;
610 goto end;
611 }
612 if (event->enabled) {
613 ret = -EEXIST;
614 goto end;
615 }
616 switch (event->instrumentation) {
617 case LTTNG_KERNEL_TRACEPOINT:
618 case LTTNG_KERNEL_SYSCALL:
619 ret = -EINVAL;
620 break;
621 case LTTNG_KERNEL_KPROBE:
622 case LTTNG_KERNEL_UPROBE:
623 case LTTNG_KERNEL_NOOP:
624 WRITE_ONCE(event->enabled, 1);
625 break;
626 case LTTNG_KERNEL_KRETPROBE:
627 ret = lttng_kretprobes_event_enable_state(event, 1);
628 break;
629 case LTTNG_KERNEL_FUNCTION: /* Fall-through. */
630 default:
631 WARN_ON_ONCE(1);
632 ret = -EINVAL;
633 }
634 end:
635 mutex_unlock(&sessions_mutex);
636 return ret;
637 }
638
639 int lttng_event_disable(struct lttng_event *event)
640 {
641 int ret = 0;
642
643 mutex_lock(&sessions_mutex);
644 if (event->chan->channel_type == METADATA_CHANNEL) {
645 ret = -EPERM;
646 goto end;
647 }
648 if (!event->enabled) {
649 ret = -EEXIST;
650 goto end;
651 }
652 switch (event->instrumentation) {
653 case LTTNG_KERNEL_TRACEPOINT:
654 case LTTNG_KERNEL_SYSCALL:
655 ret = -EINVAL;
656 break;
657 case LTTNG_KERNEL_KPROBE:
658 case LTTNG_KERNEL_UPROBE:
659 case LTTNG_KERNEL_NOOP:
660 WRITE_ONCE(event->enabled, 0);
661 break;
662 case LTTNG_KERNEL_KRETPROBE:
663 ret = lttng_kretprobes_event_enable_state(event, 0);
664 break;
665 case LTTNG_KERNEL_FUNCTION: /* Fall-through. */
666 default:
667 WARN_ON_ONCE(1);
668 ret = -EINVAL;
669 }
670 end:
671 mutex_unlock(&sessions_mutex);
672 return ret;
673 }
674
675 int lttng_event_notifier_enable(struct lttng_event_notifier *event_notifier)
676 {
677 int ret = 0;
678
679 mutex_lock(&sessions_mutex);
680 if (event_notifier->enabled) {
681 ret = -EEXIST;
682 goto end;
683 }
684 switch (event_notifier->instrumentation) {
685 case LTTNG_KERNEL_TRACEPOINT:
686 case LTTNG_KERNEL_SYSCALL:
687 ret = -EINVAL;
688 break;
689 case LTTNG_KERNEL_KPROBE:
690 case LTTNG_KERNEL_UPROBE:
691 WRITE_ONCE(event_notifier->enabled, 1);
692 break;
693 case LTTNG_KERNEL_FUNCTION:
694 case LTTNG_KERNEL_NOOP:
695 case LTTNG_KERNEL_KRETPROBE:
696 default:
697 WARN_ON_ONCE(1);
698 ret = -EINVAL;
699 }
700 end:
701 mutex_unlock(&sessions_mutex);
702 return ret;
703 }
704
705 int lttng_event_notifier_disable(struct lttng_event_notifier *event_notifier)
706 {
707 int ret = 0;
708
709 mutex_lock(&sessions_mutex);
710 if (!event_notifier->enabled) {
711 ret = -EEXIST;
712 goto end;
713 }
714 switch (event_notifier->instrumentation) {
715 case LTTNG_KERNEL_TRACEPOINT:
716 case LTTNG_KERNEL_SYSCALL:
717 ret = -EINVAL;
718 break;
719 case LTTNG_KERNEL_KPROBE:
720 case LTTNG_KERNEL_UPROBE:
721 WRITE_ONCE(event_notifier->enabled, 0);
722 break;
723 case LTTNG_KERNEL_FUNCTION:
724 case LTTNG_KERNEL_NOOP:
725 case LTTNG_KERNEL_KRETPROBE:
726 default:
727 WARN_ON_ONCE(1);
728 ret = -EINVAL;
729 }
730 end:
731 mutex_unlock(&sessions_mutex);
732 return ret;
733 }
734
735 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
736 const char *transport_name,
737 void *buf_addr,
738 size_t subbuf_size, size_t num_subbuf,
739 unsigned int switch_timer_interval,
740 unsigned int read_timer_interval,
741 enum channel_type channel_type)
742 {
743 struct lttng_channel *chan;
744 struct lttng_transport *transport = NULL;
745
746 mutex_lock(&sessions_mutex);
747 if (session->been_active && channel_type != METADATA_CHANNEL)
748 goto active; /* Refuse to add channel to active session */
749 transport = lttng_transport_find(transport_name);
750 if (!transport) {
751 printk(KERN_WARNING "LTTng: transport %s not found\n",
752 transport_name);
753 goto notransport;
754 }
755 if (!try_module_get(transport->owner)) {
756 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
757 goto notransport;
758 }
759 chan = kzalloc(sizeof(struct lttng_channel), GFP_KERNEL);
760 if (!chan)
761 goto nomem;
762 chan->session = session;
763 chan->id = session->free_chan_id++;
764 chan->ops = &transport->ops;
765 /*
766 * Note: the channel creation op already writes into the packet
767 * headers. Therefore the "chan" information used as input
768 * should be already accessible.
769 */
770 chan->chan = transport->ops.channel_create(transport_name,
771 chan, buf_addr, subbuf_size, num_subbuf,
772 switch_timer_interval, read_timer_interval);
773 if (!chan->chan)
774 goto create_error;
775 chan->tstate = 1;
776 chan->enabled = 1;
777 chan->transport = transport;
778 chan->channel_type = channel_type;
779 list_add(&chan->list, &session->chan);
780 mutex_unlock(&sessions_mutex);
781 return chan;
782
783 create_error:
784 kfree(chan);
785 nomem:
786 if (transport)
787 module_put(transport->owner);
788 notransport:
789 active:
790 mutex_unlock(&sessions_mutex);
791 return NULL;
792 }
793
794 /*
795 * Only used internally at session destruction for per-cpu channels, and
796 * when metadata channel is released.
797 * Needs to be called with sessions mutex held.
798 */
799 static
800 void _lttng_channel_destroy(struct lttng_channel *chan)
801 {
802 chan->ops->channel_destroy(chan->chan);
803 module_put(chan->transport->owner);
804 list_del(&chan->list);
805 lttng_destroy_context(chan->ctx);
806 kfree(chan);
807 }
808
809 void lttng_metadata_channel_destroy(struct lttng_channel *chan)
810 {
811 BUG_ON(chan->channel_type != METADATA_CHANNEL);
812
813 /* Protect the metadata cache with the sessions_mutex. */
814 mutex_lock(&sessions_mutex);
815 _lttng_channel_destroy(chan);
816 mutex_unlock(&sessions_mutex);
817 }
818 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
819
820 static
821 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
822 {
823 stream->finalized = 1;
824 wake_up_interruptible(&stream->read_wait);
825 }
826
827
828 /*
829 * Supports event creation while tracing session is active.
830 * Needs to be called with sessions mutex held.
831 */
832 struct lttng_event *_lttng_event_create(struct lttng_channel *chan,
833 struct lttng_kernel_event *event_param,
834 void *filter,
835 const struct lttng_event_desc *event_desc,
836 enum lttng_kernel_instrumentation itype)
837 {
838 struct lttng_session *session = chan->session;
839 struct lttng_event *event;
840 const char *event_name;
841 struct hlist_head *head;
842 int ret;
843
844 if (chan->free_event_id == -1U) {
845 ret = -EMFILE;
846 goto full;
847 }
848
849 switch (itype) {
850 case LTTNG_KERNEL_TRACEPOINT:
851 event_name = event_desc->name;
852 break;
853 case LTTNG_KERNEL_KPROBE:
854 case LTTNG_KERNEL_UPROBE:
855 case LTTNG_KERNEL_KRETPROBE:
856 case LTTNG_KERNEL_NOOP:
857 case LTTNG_KERNEL_SYSCALL:
858 event_name = event_param->name;
859 break;
860 case LTTNG_KERNEL_FUNCTION: /* Fall-through. */
861 default:
862 WARN_ON_ONCE(1);
863 ret = -EINVAL;
864 goto type_error;
865 }
866
867 head = utils_borrow_hash_table_bucket(session->events_ht.table,
868 LTTNG_EVENT_HT_SIZE, event_name);
869 lttng_hlist_for_each_entry(event, head, hlist) {
870 WARN_ON_ONCE(!event->desc);
871 if (!strncmp(event->desc->name, event_name,
872 LTTNG_KERNEL_SYM_NAME_LEN - 1)
873 && chan == event->chan) {
874 ret = -EEXIST;
875 goto exist;
876 }
877 }
878
879 event = kmem_cache_zalloc(event_cache, GFP_KERNEL);
880 if (!event) {
881 ret = -ENOMEM;
882 goto cache_error;
883 }
884 event->chan = chan;
885 event->filter = filter;
886 event->id = chan->free_event_id++;
887 event->instrumentation = itype;
888 event->evtype = LTTNG_TYPE_EVENT;
889 INIT_LIST_HEAD(&event->filter_bytecode_runtime_head);
890 INIT_LIST_HEAD(&event->enablers_ref_head);
891
892 switch (itype) {
893 case LTTNG_KERNEL_TRACEPOINT:
894 /* Event will be enabled by enabler sync. */
895 event->enabled = 0;
896 event->registered = 0;
897 event->desc = lttng_event_desc_get(event_name);
898 if (!event->desc) {
899 ret = -ENOENT;
900 goto register_error;
901 }
902 /* Populate lttng_event structure before event registration. */
903 smp_wmb();
904 break;
905 case LTTNG_KERNEL_KPROBE:
906 /*
907 * Needs to be explicitly enabled after creation, since
908 * we may want to apply filters.
909 */
910 event->enabled = 0;
911 event->registered = 1;
912 /*
913 * Populate lttng_event structure before event
914 * registration.
915 */
916 smp_wmb();
917 ret = lttng_kprobes_register_event(event_name,
918 event_param->u.kprobe.symbol_name,
919 event_param->u.kprobe.offset,
920 event_param->u.kprobe.addr,
921 event);
922 if (ret) {
923 ret = -EINVAL;
924 goto register_error;
925 }
926 ret = try_module_get(event->desc->owner);
927 WARN_ON_ONCE(!ret);
928 break;
929 case LTTNG_KERNEL_KRETPROBE:
930 {
931 struct lttng_event *event_return;
932
933 /* kretprobe defines 2 events */
934 /*
935 * Needs to be explicitly enabled after creation, since
936 * we may want to apply filters.
937 */
938 event->enabled = 0;
939 event->registered = 1;
940 event_return =
941 kmem_cache_zalloc(event_cache, GFP_KERNEL);
942 if (!event_return) {
943 ret = -ENOMEM;
944 goto register_error;
945 }
946 event_return->chan = chan;
947 event_return->filter = filter;
948 event_return->id = chan->free_event_id++;
949 event_return->enabled = 0;
950 event_return->registered = 1;
951 event_return->instrumentation = itype;
952 /*
953 * Populate lttng_event structure before kretprobe registration.
954 */
955 smp_wmb();
956 ret = lttng_kretprobes_register(event_name,
957 event_param->u.kretprobe.symbol_name,
958 event_param->u.kretprobe.offset,
959 event_param->u.kretprobe.addr,
960 event, event_return);
961 if (ret) {
962 kmem_cache_free(event_cache, event_return);
963 ret = -EINVAL;
964 goto register_error;
965 }
966 /* Take 2 refs on the module: one per event. */
967 ret = try_module_get(event->desc->owner);
968 WARN_ON_ONCE(!ret);
969 ret = try_module_get(event->desc->owner);
970 WARN_ON_ONCE(!ret);
971 ret = _lttng_event_metadata_statedump(chan->session, chan,
972 event_return);
973 WARN_ON_ONCE(ret > 0);
974 if (ret) {
975 kmem_cache_free(event_cache, event_return);
976 module_put(event->desc->owner);
977 module_put(event->desc->owner);
978 goto statedump_error;
979 }
980 list_add(&event_return->list, &chan->session->events);
981 break;
982 }
983 case LTTNG_KERNEL_NOOP:
984 case LTTNG_KERNEL_SYSCALL:
985 /*
986 * Needs to be explicitly enabled after creation, since
987 * we may want to apply filters.
988 */
989 event->enabled = 0;
990 event->registered = 0;
991 event->desc = event_desc;
992 switch (event_param->u.syscall.entryexit) {
993 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
994 ret = -EINVAL;
995 goto register_error;
996 case LTTNG_KERNEL_SYSCALL_ENTRY:
997 event->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
998 break;
999 case LTTNG_KERNEL_SYSCALL_EXIT:
1000 event->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1001 break;
1002 }
1003 switch (event_param->u.syscall.abi) {
1004 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
1005 ret = -EINVAL;
1006 goto register_error;
1007 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
1008 event->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1009 break;
1010 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
1011 event->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1012 break;
1013 }
1014 if (!event->desc) {
1015 ret = -EINVAL;
1016 goto register_error;
1017 }
1018 break;
1019 case LTTNG_KERNEL_UPROBE:
1020 /*
1021 * Needs to be explicitly enabled after creation, since
1022 * we may want to apply filters.
1023 */
1024 event->enabled = 0;
1025 event->registered = 1;
1026
1027 /*
1028 * Populate lttng_event structure before event
1029 * registration.
1030 */
1031 smp_wmb();
1032
1033 ret = lttng_uprobes_register_event(event_param->name,
1034 event_param->u.uprobe.fd,
1035 event);
1036 if (ret)
1037 goto register_error;
1038 ret = try_module_get(event->desc->owner);
1039 WARN_ON_ONCE(!ret);
1040 break;
1041 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1042 default:
1043 WARN_ON_ONCE(1);
1044 ret = -EINVAL;
1045 goto register_error;
1046 }
1047 ret = _lttng_event_metadata_statedump(chan->session, chan, event);
1048 WARN_ON_ONCE(ret > 0);
1049 if (ret) {
1050 goto statedump_error;
1051 }
1052 hlist_add_head(&event->hlist, head);
1053 list_add(&event->list, &chan->session->events);
1054 return event;
1055
1056 statedump_error:
1057 /* If a statedump error occurs, events will not be readable. */
1058 register_error:
1059 kmem_cache_free(event_cache, event);
1060 cache_error:
1061 exist:
1062 type_error:
1063 full:
1064 return ERR_PTR(ret);
1065 }
1066
1067 struct lttng_event_notifier *_lttng_event_notifier_create(
1068 const struct lttng_event_desc *event_desc,
1069 uint64_t token, uint64_t error_counter_index,
1070 struct lttng_event_notifier_group *event_notifier_group,
1071 struct lttng_kernel_event_notifier *event_notifier_param,
1072 void *filter, enum lttng_kernel_instrumentation itype)
1073 {
1074 struct lttng_event_notifier *event_notifier;
1075 struct lttng_counter *error_counter;
1076 const char *event_name;
1077 struct hlist_head *head;
1078 int ret;
1079
1080 switch (itype) {
1081 case LTTNG_KERNEL_TRACEPOINT:
1082 event_name = event_desc->name;
1083 break;
1084 case LTTNG_KERNEL_KPROBE:
1085 case LTTNG_KERNEL_UPROBE:
1086 case LTTNG_KERNEL_SYSCALL:
1087 event_name = event_notifier_param->event.name;
1088 break;
1089 case LTTNG_KERNEL_KRETPROBE:
1090 case LTTNG_KERNEL_FUNCTION:
1091 case LTTNG_KERNEL_NOOP:
1092 default:
1093 WARN_ON_ONCE(1);
1094 ret = -EINVAL;
1095 goto type_error;
1096 }
1097
1098 head = utils_borrow_hash_table_bucket(event_notifier_group->event_notifiers_ht.table,
1099 LTTNG_EVENT_NOTIFIER_HT_SIZE, event_name);
1100 lttng_hlist_for_each_entry(event_notifier, head, hlist) {
1101 WARN_ON_ONCE(!event_notifier->desc);
1102 if (!strncmp(event_notifier->desc->name, event_name,
1103 LTTNG_KERNEL_SYM_NAME_LEN - 1)
1104 && event_notifier_group == event_notifier->group
1105 && token == event_notifier->user_token) {
1106 ret = -EEXIST;
1107 goto exist;
1108 }
1109 }
1110
1111 event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
1112 if (!event_notifier) {
1113 ret = -ENOMEM;
1114 goto cache_error;
1115 }
1116
1117 event_notifier->group = event_notifier_group;
1118 event_notifier->user_token = token;
1119 event_notifier->error_counter_index = error_counter_index;
1120 event_notifier->num_captures = 0;
1121 event_notifier->filter = filter;
1122 event_notifier->instrumentation = itype;
1123 event_notifier->evtype = LTTNG_TYPE_EVENT;
1124 event_notifier->send_notification = lttng_event_notifier_notification_send;
1125 INIT_LIST_HEAD(&event_notifier->filter_bytecode_runtime_head);
1126 INIT_LIST_HEAD(&event_notifier->capture_bytecode_runtime_head);
1127 INIT_LIST_HEAD(&event_notifier->enablers_ref_head);
1128
1129 switch (itype) {
1130 case LTTNG_KERNEL_TRACEPOINT:
1131 /* Event will be enabled by enabler sync. */
1132 event_notifier->enabled = 0;
1133 event_notifier->registered = 0;
1134 event_notifier->desc = lttng_event_desc_get(event_name);
1135 if (!event_notifier->desc) {
1136 ret = -ENOENT;
1137 goto register_error;
1138 }
1139 /* Populate lttng_event_notifier structure before event registration. */
1140 smp_wmb();
1141 break;
1142 case LTTNG_KERNEL_KPROBE:
1143 /*
1144 * Needs to be explicitly enabled after creation, since
1145 * we may want to apply filters.
1146 */
1147 event_notifier->enabled = 0;
1148 event_notifier->registered = 1;
1149 /*
1150 * Populate lttng_event_notifier structure before event
1151 * registration.
1152 */
1153 smp_wmb();
1154 ret = lttng_kprobes_register_event_notifier(
1155 event_notifier_param->event.u.kprobe.symbol_name,
1156 event_notifier_param->event.u.kprobe.offset,
1157 event_notifier_param->event.u.kprobe.addr,
1158 event_notifier);
1159 if (ret) {
1160 ret = -EINVAL;
1161 goto register_error;
1162 }
1163 ret = try_module_get(event_notifier->desc->owner);
1164 WARN_ON_ONCE(!ret);
1165 break;
1166 case LTTNG_KERNEL_NOOP:
1167 case LTTNG_KERNEL_SYSCALL:
1168 /*
1169 * Needs to be explicitly enabled after creation, since
1170 * we may want to apply filters.
1171 */
1172 event_notifier->enabled = 0;
1173 event_notifier->registered = 0;
1174 event_notifier->desc = event_desc;
1175 switch (event_notifier_param->event.u.syscall.entryexit) {
1176 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
1177 ret = -EINVAL;
1178 goto register_error;
1179 case LTTNG_KERNEL_SYSCALL_ENTRY:
1180 event_notifier->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1181 break;
1182 case LTTNG_KERNEL_SYSCALL_EXIT:
1183 event_notifier->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1184 break;
1185 }
1186 switch (event_notifier_param->event.u.syscall.abi) {
1187 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
1188 ret = -EINVAL;
1189 goto register_error;
1190 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
1191 event_notifier->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1192 break;
1193 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
1194 event_notifier->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1195 break;
1196 }
1197
1198 if (!event_notifier->desc) {
1199 ret = -EINVAL;
1200 goto register_error;
1201 }
1202 break;
1203 case LTTNG_KERNEL_UPROBE:
1204 /*
1205 * Needs to be explicitly enabled after creation, since
1206 * we may want to apply filters.
1207 */
1208 event_notifier->enabled = 0;
1209 event_notifier->registered = 1;
1210
1211 /*
1212 * Populate lttng_event_notifier structure before
1213 * event_notifier registration.
1214 */
1215 smp_wmb();
1216
1217 ret = lttng_uprobes_register_event_notifier(
1218 event_notifier_param->event.name,
1219 event_notifier_param->event.u.uprobe.fd,
1220 event_notifier);
1221 if (ret)
1222 goto register_error;
1223 ret = try_module_get(event_notifier->desc->owner);
1224 WARN_ON_ONCE(!ret);
1225 break;
1226 case LTTNG_KERNEL_KRETPROBE:
1227 case LTTNG_KERNEL_FUNCTION:
1228 default:
1229 WARN_ON_ONCE(1);
1230 ret = -EINVAL;
1231 goto register_error;
1232 }
1233
1234 list_add(&event_notifier->list, &event_notifier_group->event_notifiers_head);
1235 hlist_add_head(&event_notifier->hlist, head);
1236
1237 /*
1238 * Clear the error counter bucket. The sessiond keeps track of which
1239 * bucket is currently in use. We trust it. The session lock
1240 * synchronizes against concurrent creation of the error
1241 * counter.
1242 */
1243 error_counter = event_notifier_group->error_counter;
1244 if (error_counter) {
1245 size_t dimension_index[1];
1246
1247 /*
1248 * Check that the index is within the boundary of the counter.
1249 */
1250 if (event_notifier->error_counter_index >= event_notifier_group->error_counter_len) {
1251 printk(KERN_INFO "LTTng: event_notifier: Error counter index out-of-bound: counter-len=%zu, index=%llu\n",
1252 event_notifier_group->error_counter_len, event_notifier->error_counter_index);
1253 ret = -EINVAL;
1254 goto register_error;
1255 }
1256
1257 dimension_index[0] = event_notifier->error_counter_index;
1258 ret = error_counter->ops->counter_clear(error_counter->counter, dimension_index);
1259 if (ret) {
1260 printk(KERN_INFO "LTTng: event_notifier: Unable to clear error counter bucket %llu\n",
1261 event_notifier->error_counter_index);
1262 goto register_error;
1263 }
1264 }
1265
1266 return event_notifier;
1267
1268 register_error:
1269 kmem_cache_free(event_notifier_cache, event_notifier);
1270 cache_error:
1271 exist:
1272 type_error:
1273 return ERR_PTR(ret);
1274 }
1275
1276 int lttng_kernel_counter_read(struct lttng_counter *counter,
1277 const size_t *dim_indexes, int32_t cpu,
1278 int64_t *val, bool *overflow, bool *underflow)
1279 {
1280 return counter->ops->counter_read(counter->counter, dim_indexes,
1281 cpu, val, overflow, underflow);
1282 }
1283
1284 int lttng_kernel_counter_aggregate(struct lttng_counter *counter,
1285 const size_t *dim_indexes, int64_t *val,
1286 bool *overflow, bool *underflow)
1287 {
1288 return counter->ops->counter_aggregate(counter->counter, dim_indexes,
1289 val, overflow, underflow);
1290 }
1291
1292 int lttng_kernel_counter_clear(struct lttng_counter *counter,
1293 const size_t *dim_indexes)
1294 {
1295 return counter->ops->counter_clear(counter->counter, dim_indexes);
1296 }
1297
1298 struct lttng_event *lttng_event_create(struct lttng_channel *chan,
1299 struct lttng_kernel_event *event_param,
1300 void *filter,
1301 const struct lttng_event_desc *event_desc,
1302 enum lttng_kernel_instrumentation itype)
1303 {
1304 struct lttng_event *event;
1305
1306 mutex_lock(&sessions_mutex);
1307 event = _lttng_event_create(chan, event_param, filter, event_desc,
1308 itype);
1309 mutex_unlock(&sessions_mutex);
1310 return event;
1311 }
1312
1313 struct lttng_event_notifier *lttng_event_notifier_create(
1314 const struct lttng_event_desc *event_desc,
1315 uint64_t id, uint64_t error_counter_index,
1316 struct lttng_event_notifier_group *event_notifier_group,
1317 struct lttng_kernel_event_notifier *event_notifier_param,
1318 void *filter, enum lttng_kernel_instrumentation itype)
1319 {
1320 struct lttng_event_notifier *event_notifier;
1321
1322 mutex_lock(&sessions_mutex);
1323 event_notifier = _lttng_event_notifier_create(event_desc, id,
1324 error_counter_index, event_notifier_group,
1325 event_notifier_param, filter, itype);
1326 mutex_unlock(&sessions_mutex);
1327 return event_notifier;
1328 }
1329
1330 /* Only used for tracepoints for now. */
1331 static
1332 void register_event(struct lttng_event *event)
1333 {
1334 const struct lttng_event_desc *desc;
1335 int ret = -EINVAL;
1336
1337 if (event->registered)
1338 return;
1339
1340 desc = event->desc;
1341 switch (event->instrumentation) {
1342 case LTTNG_KERNEL_TRACEPOINT:
1343 ret = lttng_wrapper_tracepoint_probe_register(desc->kname,
1344 desc->probe_callback,
1345 event);
1346 break;
1347 case LTTNG_KERNEL_SYSCALL:
1348 ret = lttng_syscall_filter_enable_event(event->chan, event);
1349 break;
1350 case LTTNG_KERNEL_KPROBE:
1351 case LTTNG_KERNEL_UPROBE:
1352 case LTTNG_KERNEL_KRETPROBE:
1353 case LTTNG_KERNEL_NOOP:
1354 ret = 0;
1355 break;
1356 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1357 default:
1358 WARN_ON_ONCE(1);
1359 }
1360 if (!ret)
1361 event->registered = 1;
1362 }
1363
1364 /*
1365 * Only used internally at session destruction.
1366 */
1367 int _lttng_event_unregister(struct lttng_event *event)
1368 {
1369 const struct lttng_event_desc *desc;
1370 int ret = -EINVAL;
1371
1372 if (!event->registered)
1373 return 0;
1374
1375 desc = event->desc;
1376 switch (event->instrumentation) {
1377 case LTTNG_KERNEL_TRACEPOINT:
1378 ret = lttng_wrapper_tracepoint_probe_unregister(event->desc->kname,
1379 event->desc->probe_callback,
1380 event);
1381 break;
1382 case LTTNG_KERNEL_KPROBE:
1383 lttng_kprobes_unregister_event(event);
1384 ret = 0;
1385 break;
1386 case LTTNG_KERNEL_KRETPROBE:
1387 lttng_kretprobes_unregister(event);
1388 ret = 0;
1389 break;
1390 case LTTNG_KERNEL_SYSCALL:
1391 ret = lttng_syscall_filter_disable_event(event->chan, event);
1392 break;
1393 case LTTNG_KERNEL_NOOP:
1394 ret = 0;
1395 break;
1396 case LTTNG_KERNEL_UPROBE:
1397 lttng_uprobes_unregister_event(event);
1398 ret = 0;
1399 break;
1400 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1401 default:
1402 WARN_ON_ONCE(1);
1403 }
1404 if (!ret)
1405 event->registered = 0;
1406 return ret;
1407 }
1408
1409 /* Only used for tracepoints for now. */
1410 static
1411 void register_event_notifier(struct lttng_event_notifier *event_notifier)
1412 {
1413 const struct lttng_event_desc *desc;
1414 int ret = -EINVAL;
1415
1416 if (event_notifier->registered)
1417 return;
1418
1419 desc = event_notifier->desc;
1420 switch (event_notifier->instrumentation) {
1421 case LTTNG_KERNEL_TRACEPOINT:
1422 ret = lttng_wrapper_tracepoint_probe_register(desc->kname,
1423 desc->event_notifier_callback,
1424 event_notifier);
1425 break;
1426 case LTTNG_KERNEL_SYSCALL:
1427 ret = lttng_syscall_filter_enable_event_notifier(event_notifier);
1428 break;
1429 case LTTNG_KERNEL_KPROBE:
1430 case LTTNG_KERNEL_UPROBE:
1431 ret = 0;
1432 break;
1433 case LTTNG_KERNEL_KRETPROBE:
1434 case LTTNG_KERNEL_FUNCTION:
1435 case LTTNG_KERNEL_NOOP:
1436 default:
1437 WARN_ON_ONCE(1);
1438 }
1439 if (!ret)
1440 event_notifier->registered = 1;
1441 }
1442
1443 static
1444 int _lttng_event_notifier_unregister(
1445 struct lttng_event_notifier *event_notifier)
1446 {
1447 const struct lttng_event_desc *desc;
1448 int ret = -EINVAL;
1449
1450 if (!event_notifier->registered)
1451 return 0;
1452
1453 desc = event_notifier->desc;
1454 switch (event_notifier->instrumentation) {
1455 case LTTNG_KERNEL_TRACEPOINT:
1456 ret = lttng_wrapper_tracepoint_probe_unregister(event_notifier->desc->kname,
1457 event_notifier->desc->event_notifier_callback,
1458 event_notifier);
1459 break;
1460 case LTTNG_KERNEL_KPROBE:
1461 lttng_kprobes_unregister_event_notifier(event_notifier);
1462 ret = 0;
1463 break;
1464 case LTTNG_KERNEL_UPROBE:
1465 lttng_uprobes_unregister_event_notifier(event_notifier);
1466 ret = 0;
1467 break;
1468 case LTTNG_KERNEL_SYSCALL:
1469 ret = lttng_syscall_filter_disable_event_notifier(event_notifier);
1470 break;
1471 case LTTNG_KERNEL_KRETPROBE:
1472 case LTTNG_KERNEL_FUNCTION:
1473 case LTTNG_KERNEL_NOOP:
1474 default:
1475 WARN_ON_ONCE(1);
1476 }
1477 if (!ret)
1478 event_notifier->registered = 0;
1479 return ret;
1480 }
1481
1482 /*
1483 * Only used internally at session destruction.
1484 */
1485 static
1486 void _lttng_event_destroy(struct lttng_event *event)
1487 {
1488 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1489
1490 switch (event->instrumentation) {
1491 case LTTNG_KERNEL_TRACEPOINT:
1492 lttng_event_desc_put(event->desc);
1493 break;
1494 case LTTNG_KERNEL_KPROBE:
1495 module_put(event->desc->owner);
1496 lttng_kprobes_destroy_event_private(event);
1497 break;
1498 case LTTNG_KERNEL_KRETPROBE:
1499 module_put(event->desc->owner);
1500 lttng_kretprobes_destroy_private(event);
1501 break;
1502 case LTTNG_KERNEL_NOOP:
1503 case LTTNG_KERNEL_SYSCALL:
1504 break;
1505 case LTTNG_KERNEL_UPROBE:
1506 module_put(event->desc->owner);
1507 lttng_uprobes_destroy_event_private(event);
1508 break;
1509 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1510 default:
1511 WARN_ON_ONCE(1);
1512 }
1513 list_del(&event->list);
1514 lttng_destroy_context(event->ctx);
1515 lttng_free_event_filter_runtime(event);
1516 /* Free event enabler refs */
1517 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1518 &event->enablers_ref_head, node)
1519 kfree(enabler_ref);
1520 kmem_cache_free(event_cache, event);
1521 }
1522
1523 /*
1524 * Only used internally at session destruction.
1525 */
1526 static
1527 void _lttng_event_notifier_destroy(struct lttng_event_notifier *event_notifier)
1528 {
1529 switch (event_notifier->instrumentation) {
1530 case LTTNG_KERNEL_TRACEPOINT:
1531 lttng_event_desc_put(event_notifier->desc);
1532 break;
1533 case LTTNG_KERNEL_KPROBE:
1534 module_put(event_notifier->desc->owner);
1535 lttng_kprobes_destroy_event_notifier_private(event_notifier);
1536 break;
1537 case LTTNG_KERNEL_NOOP:
1538 case LTTNG_KERNEL_SYSCALL:
1539 break;
1540 case LTTNG_KERNEL_UPROBE:
1541 module_put(event_notifier->desc->owner);
1542 lttng_uprobes_destroy_event_notifier_private(event_notifier);
1543 break;
1544 case LTTNG_KERNEL_KRETPROBE:
1545 case LTTNG_KERNEL_FUNCTION:
1546 default:
1547 WARN_ON_ONCE(1);
1548 }
1549 list_del(&event_notifier->list);
1550 kmem_cache_free(event_notifier_cache, event_notifier);
1551 }
1552
1553 struct lttng_id_tracker *get_tracker(struct lttng_session *session,
1554 enum tracker_type tracker_type)
1555 {
1556 switch (tracker_type) {
1557 case TRACKER_PID:
1558 return &session->pid_tracker;
1559 case TRACKER_VPID:
1560 return &session->vpid_tracker;
1561 case TRACKER_UID:
1562 return &session->uid_tracker;
1563 case TRACKER_VUID:
1564 return &session->vuid_tracker;
1565 case TRACKER_GID:
1566 return &session->gid_tracker;
1567 case TRACKER_VGID:
1568 return &session->vgid_tracker;
1569 default:
1570 WARN_ON_ONCE(1);
1571 return NULL;
1572 }
1573 }
1574
1575 int lttng_session_track_id(struct lttng_session *session,
1576 enum tracker_type tracker_type, int id)
1577 {
1578 struct lttng_id_tracker *tracker;
1579 int ret;
1580
1581 tracker = get_tracker(session, tracker_type);
1582 if (!tracker)
1583 return -EINVAL;
1584 if (id < -1)
1585 return -EINVAL;
1586 mutex_lock(&sessions_mutex);
1587 if (id == -1) {
1588 /* track all ids: destroy tracker. */
1589 lttng_id_tracker_destroy(tracker, true);
1590 ret = 0;
1591 } else {
1592 ret = lttng_id_tracker_add(tracker, id);
1593 }
1594 mutex_unlock(&sessions_mutex);
1595 return ret;
1596 }
1597
1598 int lttng_session_untrack_id(struct lttng_session *session,
1599 enum tracker_type tracker_type, int id)
1600 {
1601 struct lttng_id_tracker *tracker;
1602 int ret;
1603
1604 tracker = get_tracker(session, tracker_type);
1605 if (!tracker)
1606 return -EINVAL;
1607 if (id < -1)
1608 return -EINVAL;
1609 mutex_lock(&sessions_mutex);
1610 if (id == -1) {
1611 /* untrack all ids: replace by empty tracker. */
1612 ret = lttng_id_tracker_empty_set(tracker);
1613 } else {
1614 ret = lttng_id_tracker_del(tracker, id);
1615 }
1616 mutex_unlock(&sessions_mutex);
1617 return ret;
1618 }
1619
1620 static
1621 void *id_list_start(struct seq_file *m, loff_t *pos)
1622 {
1623 struct lttng_id_tracker *id_tracker = m->private;
1624 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1625 struct lttng_id_hash_node *e;
1626 int iter = 0, i;
1627
1628 mutex_lock(&sessions_mutex);
1629 if (id_tracker_p) {
1630 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1631 struct hlist_head *head = &id_tracker_p->id_hash[i];
1632
1633 lttng_hlist_for_each_entry(e, head, hlist) {
1634 if (iter++ >= *pos)
1635 return e;
1636 }
1637 }
1638 } else {
1639 /* ID tracker disabled. */
1640 if (iter >= *pos && iter == 0) {
1641 return id_tracker_p; /* empty tracker */
1642 }
1643 iter++;
1644 }
1645 /* End of list */
1646 return NULL;
1647 }
1648
1649 /* Called with sessions_mutex held. */
1650 static
1651 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1652 {
1653 struct lttng_id_tracker *id_tracker = m->private;
1654 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1655 struct lttng_id_hash_node *e;
1656 int iter = 0, i;
1657
1658 (*ppos)++;
1659 if (id_tracker_p) {
1660 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1661 struct hlist_head *head = &id_tracker_p->id_hash[i];
1662
1663 lttng_hlist_for_each_entry(e, head, hlist) {
1664 if (iter++ >= *ppos)
1665 return e;
1666 }
1667 }
1668 } else {
1669 /* ID tracker disabled. */
1670 if (iter >= *ppos && iter == 0)
1671 return p; /* empty tracker */
1672 iter++;
1673 }
1674
1675 /* End of list */
1676 return NULL;
1677 }
1678
1679 static
1680 void id_list_stop(struct seq_file *m, void *p)
1681 {
1682 mutex_unlock(&sessions_mutex);
1683 }
1684
1685 static
1686 int id_list_show(struct seq_file *m, void *p)
1687 {
1688 struct lttng_id_tracker *id_tracker = m->private;
1689 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1690 int id;
1691
1692 if (p == id_tracker_p) {
1693 /* Tracker disabled. */
1694 id = -1;
1695 } else {
1696 const struct lttng_id_hash_node *e = p;
1697
1698 id = lttng_id_tracker_get_node_id(e);
1699 }
1700 switch (id_tracker->tracker_type) {
1701 case TRACKER_PID:
1702 seq_printf(m, "process { pid = %d; };\n", id);
1703 break;
1704 case TRACKER_VPID:
1705 seq_printf(m, "process { vpid = %d; };\n", id);
1706 break;
1707 case TRACKER_UID:
1708 seq_printf(m, "user { uid = %d; };\n", id);
1709 break;
1710 case TRACKER_VUID:
1711 seq_printf(m, "user { vuid = %d; };\n", id);
1712 break;
1713 case TRACKER_GID:
1714 seq_printf(m, "group { gid = %d; };\n", id);
1715 break;
1716 case TRACKER_VGID:
1717 seq_printf(m, "group { vgid = %d; };\n", id);
1718 break;
1719 default:
1720 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1721 }
1722 return 0;
1723 }
1724
1725 static
1726 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1727 .start = id_list_start,
1728 .next = id_list_next,
1729 .stop = id_list_stop,
1730 .show = id_list_show,
1731 };
1732
1733 static
1734 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1735 {
1736 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1737 }
1738
1739 static
1740 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1741 {
1742 struct seq_file *m = file->private_data;
1743 struct lttng_id_tracker *id_tracker = m->private;
1744 int ret;
1745
1746 WARN_ON_ONCE(!id_tracker);
1747 ret = seq_release(inode, file);
1748 if (!ret)
1749 fput(id_tracker->session->file);
1750 return ret;
1751 }
1752
1753 const struct file_operations lttng_tracker_ids_list_fops = {
1754 .owner = THIS_MODULE,
1755 .open = lttng_tracker_ids_list_open,
1756 .read = seq_read,
1757 .llseek = seq_lseek,
1758 .release = lttng_tracker_ids_list_release,
1759 };
1760
1761 int lttng_session_list_tracker_ids(struct lttng_session *session,
1762 enum tracker_type tracker_type)
1763 {
1764 struct file *tracker_ids_list_file;
1765 struct seq_file *m;
1766 int file_fd, ret;
1767
1768 file_fd = lttng_get_unused_fd();
1769 if (file_fd < 0) {
1770 ret = file_fd;
1771 goto fd_error;
1772 }
1773
1774 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1775 &lttng_tracker_ids_list_fops,
1776 NULL, O_RDWR);
1777 if (IS_ERR(tracker_ids_list_file)) {
1778 ret = PTR_ERR(tracker_ids_list_file);
1779 goto file_error;
1780 }
1781 if (!atomic_long_add_unless(&session->file->f_count, 1, LONG_MAX)) {
1782 ret = -EOVERFLOW;
1783 goto refcount_error;
1784 }
1785 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1786 if (ret < 0)
1787 goto open_error;
1788 m = tracker_ids_list_file->private_data;
1789
1790 m->private = get_tracker(session, tracker_type);
1791 BUG_ON(!m->private);
1792 fd_install(file_fd, tracker_ids_list_file);
1793
1794 return file_fd;
1795
1796 open_error:
1797 atomic_long_dec(&session->file->f_count);
1798 refcount_error:
1799 fput(tracker_ids_list_file);
1800 file_error:
1801 put_unused_fd(file_fd);
1802 fd_error:
1803 return ret;
1804 }
1805
1806 /*
1807 * Enabler management.
1808 */
1809 static
1810 int lttng_match_enabler_star_glob(const char *desc_name,
1811 const char *pattern)
1812 {
1813 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1814 desc_name, LTTNG_SIZE_MAX))
1815 return 0;
1816 return 1;
1817 }
1818
1819 static
1820 int lttng_match_enabler_name(const char *desc_name,
1821 const char *name)
1822 {
1823 if (strcmp(desc_name, name))
1824 return 0;
1825 return 1;
1826 }
1827
1828 int lttng_desc_match_enabler(const struct lttng_event_desc *desc,
1829 struct lttng_enabler *enabler)
1830 {
1831 const char *desc_name, *enabler_name;
1832 bool compat = false, entry = false;
1833
1834 enabler_name = enabler->event_param.name;
1835 switch (enabler->event_param.instrumentation) {
1836 case LTTNG_KERNEL_TRACEPOINT:
1837 desc_name = desc->name;
1838 switch (enabler->format_type) {
1839 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1840 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1841 case LTTNG_ENABLER_FORMAT_NAME:
1842 return lttng_match_enabler_name(desc_name, enabler_name);
1843 default:
1844 return -EINVAL;
1845 }
1846 break;
1847 case LTTNG_KERNEL_SYSCALL:
1848 desc_name = desc->name;
1849 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
1850 desc_name += strlen("compat_");
1851 compat = true;
1852 }
1853 if (!strncmp(desc_name, "syscall_exit_",
1854 strlen("syscall_exit_"))) {
1855 desc_name += strlen("syscall_exit_");
1856 } else if (!strncmp(desc_name, "syscall_entry_",
1857 strlen("syscall_entry_"))) {
1858 desc_name += strlen("syscall_entry_");
1859 entry = true;
1860 } else {
1861 WARN_ON_ONCE(1);
1862 return -EINVAL;
1863 }
1864 switch (enabler->event_param.u.syscall.entryexit) {
1865 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
1866 break;
1867 case LTTNG_KERNEL_SYSCALL_ENTRY:
1868 if (!entry)
1869 return 0;
1870 break;
1871 case LTTNG_KERNEL_SYSCALL_EXIT:
1872 if (entry)
1873 return 0;
1874 break;
1875 default:
1876 return -EINVAL;
1877 }
1878 switch (enabler->event_param.u.syscall.abi) {
1879 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
1880 break;
1881 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
1882 if (compat)
1883 return 0;
1884 break;
1885 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
1886 if (!compat)
1887 return 0;
1888 break;
1889 default:
1890 return -EINVAL;
1891 }
1892 switch (enabler->event_param.u.syscall.match) {
1893 case LTTNG_KERNEL_SYSCALL_MATCH_NAME:
1894 switch (enabler->format_type) {
1895 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1896 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1897 case LTTNG_ENABLER_FORMAT_NAME:
1898 return lttng_match_enabler_name(desc_name, enabler_name);
1899 default:
1900 return -EINVAL;
1901 }
1902 break;
1903 case LTTNG_KERNEL_SYSCALL_MATCH_NR:
1904 return -EINVAL; /* Not implemented. */
1905 default:
1906 return -EINVAL;
1907 }
1908 break;
1909 default:
1910 WARN_ON_ONCE(1);
1911 return -EINVAL;
1912 }
1913 }
1914
1915 static
1916 int lttng_event_enabler_match_event(struct lttng_event_enabler *event_enabler,
1917 struct lttng_event *event)
1918 {
1919 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(
1920 event_enabler);
1921
1922 if (base_enabler->event_param.instrumentation != event->instrumentation)
1923 return 0;
1924 if (lttng_desc_match_enabler(event->desc, base_enabler)
1925 && event->chan == event_enabler->chan)
1926 return 1;
1927 else
1928 return 0;
1929 }
1930
1931 static
1932 int lttng_event_notifier_enabler_match_event_notifier(struct lttng_event_notifier_enabler *event_notifier_enabler,
1933 struct lttng_event_notifier *event_notifier)
1934 {
1935 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(
1936 event_notifier_enabler);
1937
1938 if (base_enabler->event_param.instrumentation != event_notifier->instrumentation)
1939 return 0;
1940 if (lttng_desc_match_enabler(event_notifier->desc, base_enabler)
1941 && event_notifier->group == event_notifier_enabler->group
1942 && event_notifier->user_token == event_notifier_enabler->base.user_token)
1943 return 1;
1944 else
1945 return 0;
1946 }
1947
1948 static
1949 struct lttng_enabler_ref *lttng_enabler_ref(
1950 struct list_head *enablers_ref_list,
1951 struct lttng_enabler *enabler)
1952 {
1953 struct lttng_enabler_ref *enabler_ref;
1954
1955 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
1956 if (enabler_ref->ref == enabler)
1957 return enabler_ref;
1958 }
1959 return NULL;
1960 }
1961
1962 static
1963 void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler *event_enabler)
1964 {
1965 struct lttng_session *session = event_enabler->chan->session;
1966 struct lttng_probe_desc *probe_desc;
1967 const struct lttng_event_desc *desc;
1968 int i;
1969 struct list_head *probe_list;
1970
1971 probe_list = lttng_get_probe_list_head();
1972 /*
1973 * For each probe event, if we find that a probe event matches
1974 * our enabler, create an associated lttng_event if not
1975 * already present.
1976 */
1977 list_for_each_entry(probe_desc, probe_list, head) {
1978 for (i = 0; i < probe_desc->nr_events; i++) {
1979 int found = 0;
1980 struct hlist_head *head;
1981 struct lttng_event *event;
1982
1983 desc = probe_desc->event_desc[i];
1984 if (!lttng_desc_match_enabler(desc,
1985 lttng_event_enabler_as_enabler(event_enabler)))
1986 continue;
1987
1988 /*
1989 * Check if already created.
1990 */
1991 head = utils_borrow_hash_table_bucket(
1992 session->events_ht.table, LTTNG_EVENT_HT_SIZE,
1993 desc->name);
1994 lttng_hlist_for_each_entry(event, head, hlist) {
1995 if (event->desc == desc
1996 && event->chan == event_enabler->chan)
1997 found = 1;
1998 }
1999 if (found)
2000 continue;
2001
2002 /*
2003 * We need to create an event for this
2004 * event probe.
2005 */
2006 event = _lttng_event_create(event_enabler->chan,
2007 NULL, NULL, desc,
2008 LTTNG_KERNEL_TRACEPOINT);
2009 if (!event) {
2010 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2011 probe_desc->event_desc[i]->name);
2012 }
2013 }
2014 }
2015 }
2016
2017 static
2018 void lttng_create_tracepoint_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2019 {
2020 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2021 struct lttng_probe_desc *probe_desc;
2022 const struct lttng_event_desc *desc;
2023 int i;
2024 struct list_head *probe_list;
2025
2026 probe_list = lttng_get_probe_list_head();
2027 /*
2028 * For each probe event, if we find that a probe event matches
2029 * our enabler, create an associated lttng_event_notifier if not
2030 * already present.
2031 */
2032 list_for_each_entry(probe_desc, probe_list, head) {
2033 for (i = 0; i < probe_desc->nr_events; i++) {
2034 int found = 0;
2035 struct hlist_head *head;
2036 struct lttng_event_notifier *event_notifier;
2037
2038 desc = probe_desc->event_desc[i];
2039 if (!lttng_desc_match_enabler(desc,
2040 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)))
2041 continue;
2042
2043 /*
2044 * Check if already created.
2045 */
2046 head = utils_borrow_hash_table_bucket(
2047 event_notifier_group->event_notifiers_ht.table,
2048 LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->name);
2049 lttng_hlist_for_each_entry(event_notifier, head, hlist) {
2050 if (event_notifier->desc == desc
2051 && event_notifier->user_token == event_notifier_enabler->base.user_token)
2052 found = 1;
2053 }
2054 if (found)
2055 continue;
2056
2057 /*
2058 * We need to create a event_notifier for this event probe.
2059 */
2060 event_notifier = _lttng_event_notifier_create(desc,
2061 event_notifier_enabler->base.user_token,
2062 event_notifier_enabler->error_counter_index,
2063 event_notifier_group, NULL, NULL,
2064 LTTNG_KERNEL_TRACEPOINT);
2065 if (IS_ERR(event_notifier)) {
2066 printk(KERN_INFO "Unable to create event_notifier %s\n",
2067 probe_desc->event_desc[i]->name);
2068 }
2069 }
2070 }
2071 }
2072
2073 static
2074 void lttng_create_syscall_event_if_missing(struct lttng_event_enabler *event_enabler)
2075 {
2076 int ret;
2077
2078 ret = lttng_syscalls_register_event(event_enabler, NULL);
2079 WARN_ON_ONCE(ret);
2080 }
2081
2082 static
2083 void lttng_create_syscall_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2084 {
2085 int ret;
2086
2087 ret = lttng_syscalls_register_event_notifier(event_notifier_enabler, NULL);
2088 WARN_ON_ONCE(ret);
2089 ret = lttng_syscals_create_matching_event_notifiers(event_notifier_enabler, NULL);
2090 WARN_ON_ONCE(ret);
2091 }
2092
2093 /*
2094 * Create struct lttng_event if it is missing and present in the list of
2095 * tracepoint probes.
2096 * Should be called with sessions mutex held.
2097 */
2098 static
2099 void lttng_create_event_if_missing(struct lttng_event_enabler *event_enabler)
2100 {
2101 switch (event_enabler->base.event_param.instrumentation) {
2102 case LTTNG_KERNEL_TRACEPOINT:
2103 lttng_create_tracepoint_event_if_missing(event_enabler);
2104 break;
2105 case LTTNG_KERNEL_SYSCALL:
2106 lttng_create_syscall_event_if_missing(event_enabler);
2107 break;
2108 default:
2109 WARN_ON_ONCE(1);
2110 break;
2111 }
2112 }
2113
2114 /*
2115 * Create events associated with an event_enabler (if not already present),
2116 * and add backward reference from the event to the enabler.
2117 * Should be called with sessions mutex held.
2118 */
2119 static
2120 int lttng_event_enabler_ref_events(struct lttng_event_enabler *event_enabler)
2121 {
2122 struct lttng_channel *chan = event_enabler->chan;
2123 struct lttng_session *session = event_enabler->chan->session;
2124 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(event_enabler);
2125 struct lttng_event *event;
2126
2127 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_SYSCALL &&
2128 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_SYSCALL_ABI_ALL &&
2129 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_SYSCALL_MATCH_NAME &&
2130 !strcmp(base_enabler->event_param.name, "*")) {
2131 int enabled = base_enabler->enabled;
2132 enum lttng_kernel_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2133
2134 if (entryexit == LTTNG_KERNEL_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2135 WRITE_ONCE(chan->syscall_all_entry, enabled);
2136
2137 if (entryexit == LTTNG_KERNEL_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2138 WRITE_ONCE(chan->syscall_all_exit, enabled);
2139 }
2140
2141 /* First ensure that probe events are created for this enabler. */
2142 lttng_create_event_if_missing(event_enabler);
2143
2144 /* For each event matching event_enabler in session event list. */
2145 list_for_each_entry(event, &session->events, list) {
2146 struct lttng_enabler_ref *enabler_ref;
2147
2148 if (!lttng_event_enabler_match_event(event_enabler, event))
2149 continue;
2150 enabler_ref = lttng_enabler_ref(&event->enablers_ref_head,
2151 lttng_event_enabler_as_enabler(event_enabler));
2152 if (!enabler_ref) {
2153 /*
2154 * If no backward ref, create it.
2155 * Add backward ref from event to event_enabler.
2156 */
2157 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2158 if (!enabler_ref)
2159 return -ENOMEM;
2160 enabler_ref->ref = lttng_event_enabler_as_enabler(event_enabler);
2161 list_add(&enabler_ref->node,
2162 &event->enablers_ref_head);
2163 }
2164
2165 /*
2166 * Link filter bytecodes if not linked yet.
2167 */
2168 lttng_enabler_link_bytecode(event->desc,
2169 lttng_static_ctx,
2170 &event->filter_bytecode_runtime_head,
2171 &lttng_event_enabler_as_enabler(event_enabler)->filter_bytecode_head);
2172
2173 /* TODO: merge event context. */
2174 }
2175 return 0;
2176 }
2177
2178 /*
2179 * Create struct lttng_event_notifier if it is missing and present in the list of
2180 * tracepoint probes.
2181 * Should be called with sessions mutex held.
2182 */
2183 static
2184 void lttng_create_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2185 {
2186 switch (event_notifier_enabler->base.event_param.instrumentation) {
2187 case LTTNG_KERNEL_TRACEPOINT:
2188 lttng_create_tracepoint_event_notifier_if_missing(event_notifier_enabler);
2189 break;
2190 case LTTNG_KERNEL_SYSCALL:
2191 lttng_create_syscall_event_notifier_if_missing(event_notifier_enabler);
2192 break;
2193 default:
2194 WARN_ON_ONCE(1);
2195 break;
2196 }
2197 }
2198
2199 /*
2200 * Create event_notifiers associated with a event_notifier enabler (if not already present).
2201 */
2202 static
2203 int lttng_event_notifier_enabler_ref_event_notifiers(
2204 struct lttng_event_notifier_enabler *event_notifier_enabler)
2205 {
2206 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2207 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2208 struct lttng_event_notifier *event_notifier;
2209
2210 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_SYSCALL &&
2211 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_SYSCALL_ABI_ALL &&
2212 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_SYSCALL_MATCH_NAME &&
2213 !strcmp(base_enabler->event_param.name, "*")) {
2214
2215 int enabled = base_enabler->enabled;
2216 enum lttng_kernel_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2217
2218 if (entryexit == LTTNG_KERNEL_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2219 WRITE_ONCE(event_notifier_group->syscall_all_entry, enabled);
2220
2221 if (entryexit == LTTNG_KERNEL_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2222 WRITE_ONCE(event_notifier_group->syscall_all_exit, enabled);
2223
2224 }
2225
2226 /* First ensure that probe event_notifiers are created for this enabler. */
2227 lttng_create_event_notifier_if_missing(event_notifier_enabler);
2228
2229 /* Link the created event_notifier with its associated enabler. */
2230 list_for_each_entry(event_notifier, &event_notifier_group->event_notifiers_head, list) {
2231 struct lttng_enabler_ref *enabler_ref;
2232
2233 if (!lttng_event_notifier_enabler_match_event_notifier(event_notifier_enabler, event_notifier))
2234 continue;
2235
2236 enabler_ref = lttng_enabler_ref(&event_notifier->enablers_ref_head,
2237 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2238 if (!enabler_ref) {
2239 /*
2240 * If no backward ref, create it.
2241 * Add backward ref from event_notifier to enabler.
2242 */
2243 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2244 if (!enabler_ref)
2245 return -ENOMEM;
2246
2247 enabler_ref->ref = lttng_event_notifier_enabler_as_enabler(
2248 event_notifier_enabler);
2249 list_add(&enabler_ref->node,
2250 &event_notifier->enablers_ref_head);
2251 }
2252
2253 /*
2254 * Link filter bytecodes if not linked yet.
2255 */
2256 lttng_enabler_link_bytecode(event_notifier->desc,
2257 lttng_static_ctx, &event_notifier->filter_bytecode_runtime_head,
2258 &lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->filter_bytecode_head);
2259
2260 /* Link capture bytecodes if not linked yet. */
2261 lttng_enabler_link_bytecode(event_notifier->desc,
2262 lttng_static_ctx, &event_notifier->capture_bytecode_runtime_head,
2263 &event_notifier_enabler->capture_bytecode_head);
2264
2265 event_notifier->num_captures = event_notifier_enabler->num_captures;
2266 }
2267 return 0;
2268 }
2269
2270 /*
2271 * Called at module load: connect the probe on all enablers matching
2272 * this event.
2273 * Called with sessions lock held.
2274 */
2275 int lttng_fix_pending_events(void)
2276 {
2277 struct lttng_session *session;
2278
2279 list_for_each_entry(session, &sessions, list)
2280 lttng_session_lazy_sync_event_enablers(session);
2281 return 0;
2282 }
2283
2284 static bool lttng_event_notifier_group_has_active_event_notifiers(
2285 struct lttng_event_notifier_group *event_notifier_group)
2286 {
2287 struct lttng_event_notifier_enabler *event_notifier_enabler;
2288
2289 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head,
2290 node) {
2291 if (event_notifier_enabler->base.enabled)
2292 return true;
2293 }
2294 return false;
2295 }
2296
2297 bool lttng_event_notifier_active(void)
2298 {
2299 struct lttng_event_notifier_group *event_notifier_group;
2300
2301 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2302 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2303 return true;
2304 }
2305 return false;
2306 }
2307
2308 int lttng_fix_pending_event_notifiers(void)
2309 {
2310 struct lttng_event_notifier_group *event_notifier_group;
2311
2312 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2313 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2314 return 0;
2315 }
2316
2317 struct lttng_event_enabler *lttng_event_enabler_create(
2318 enum lttng_enabler_format_type format_type,
2319 struct lttng_kernel_event *event_param,
2320 struct lttng_channel *chan)
2321 {
2322 struct lttng_event_enabler *event_enabler;
2323
2324 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2325 if (!event_enabler)
2326 return NULL;
2327 event_enabler->base.format_type = format_type;
2328 INIT_LIST_HEAD(&event_enabler->base.filter_bytecode_head);
2329 memcpy(&event_enabler->base.event_param, event_param,
2330 sizeof(event_enabler->base.event_param));
2331 event_enabler->chan = chan;
2332 /* ctx left NULL */
2333 event_enabler->base.enabled = 0;
2334 event_enabler->base.evtype = LTTNG_TYPE_ENABLER;
2335 mutex_lock(&sessions_mutex);
2336 list_add(&event_enabler->node, &event_enabler->chan->session->enablers_head);
2337 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2338 mutex_unlock(&sessions_mutex);
2339 return event_enabler;
2340 }
2341
2342 int lttng_event_enabler_enable(struct lttng_event_enabler *event_enabler)
2343 {
2344 mutex_lock(&sessions_mutex);
2345 lttng_event_enabler_as_enabler(event_enabler)->enabled = 1;
2346 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2347 mutex_unlock(&sessions_mutex);
2348 return 0;
2349 }
2350
2351 int lttng_event_enabler_disable(struct lttng_event_enabler *event_enabler)
2352 {
2353 mutex_lock(&sessions_mutex);
2354 lttng_event_enabler_as_enabler(event_enabler)->enabled = 0;
2355 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2356 mutex_unlock(&sessions_mutex);
2357 return 0;
2358 }
2359
2360 static
2361 int lttng_enabler_attach_filter_bytecode(struct lttng_enabler *enabler,
2362 struct lttng_kernel_filter_bytecode __user *bytecode)
2363 {
2364 struct lttng_bytecode_node *bytecode_node;
2365 uint32_t bytecode_len;
2366 int ret;
2367
2368 ret = get_user(bytecode_len, &bytecode->len);
2369 if (ret)
2370 return ret;
2371 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2372 GFP_KERNEL);
2373 if (!bytecode_node)
2374 return -ENOMEM;
2375 ret = copy_from_user(&bytecode_node->bc, bytecode,
2376 sizeof(*bytecode) + bytecode_len);
2377 if (ret)
2378 goto error_free;
2379
2380 bytecode_node->type = LTTNG_BYTECODE_NODE_TYPE_FILTER;
2381 bytecode_node->enabler = enabler;
2382 /* Enforce length based on allocated size */
2383 bytecode_node->bc.len = bytecode_len;
2384 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2385
2386 return 0;
2387
2388 error_free:
2389 lttng_kvfree(bytecode_node);
2390 return ret;
2391 }
2392
2393 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler *event_enabler,
2394 struct lttng_kernel_filter_bytecode __user *bytecode)
2395 {
2396 int ret;
2397 ret = lttng_enabler_attach_filter_bytecode(
2398 lttng_event_enabler_as_enabler(event_enabler), bytecode);
2399 if (ret)
2400 goto error;
2401
2402 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2403 return 0;
2404
2405 error:
2406 return ret;
2407 }
2408
2409 int lttng_event_add_callsite(struct lttng_event *event,
2410 struct lttng_kernel_event_callsite __user *callsite)
2411 {
2412
2413 switch (event->instrumentation) {
2414 case LTTNG_KERNEL_UPROBE:
2415 return lttng_uprobes_event_add_callsite(event, callsite);
2416 default:
2417 return -EINVAL;
2418 }
2419 }
2420
2421 int lttng_event_enabler_attach_context(struct lttng_event_enabler *event_enabler,
2422 struct lttng_kernel_context *context_param)
2423 {
2424 return -ENOSYS;
2425 }
2426
2427 static
2428 void lttng_enabler_destroy(struct lttng_enabler *enabler)
2429 {
2430 struct lttng_bytecode_node *filter_node, *tmp_filter_node;
2431
2432 /* Destroy filter bytecode */
2433 list_for_each_entry_safe(filter_node, tmp_filter_node,
2434 &enabler->filter_bytecode_head, node) {
2435 lttng_kvfree(filter_node);
2436 }
2437 }
2438
2439 static
2440 void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler)
2441 {
2442 lttng_enabler_destroy(lttng_event_enabler_as_enabler(event_enabler));
2443
2444 /* Destroy contexts */
2445 lttng_destroy_context(event_enabler->ctx);
2446
2447 list_del(&event_enabler->node);
2448 kfree(event_enabler);
2449 }
2450
2451 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2452 struct lttng_event_notifier_group *event_notifier_group,
2453 enum lttng_enabler_format_type format_type,
2454 struct lttng_kernel_event_notifier *event_notifier_param)
2455 {
2456 struct lttng_event_notifier_enabler *event_notifier_enabler;
2457
2458 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2459 if (!event_notifier_enabler)
2460 return NULL;
2461
2462 event_notifier_enabler->base.format_type = format_type;
2463 INIT_LIST_HEAD(&event_notifier_enabler->base.filter_bytecode_head);
2464 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2465
2466 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2467 event_notifier_enabler->num_captures = 0;
2468
2469 memcpy(&event_notifier_enabler->base.event_param, &event_notifier_param->event,
2470 sizeof(event_notifier_enabler->base.event_param));
2471 event_notifier_enabler->base.evtype = LTTNG_TYPE_ENABLER;
2472
2473 event_notifier_enabler->base.enabled = 0;
2474 event_notifier_enabler->base.user_token = event_notifier_param->event.token;
2475 event_notifier_enabler->group = event_notifier_group;
2476
2477 mutex_lock(&sessions_mutex);
2478 list_add(&event_notifier_enabler->node, &event_notifier_enabler->group->enablers_head);
2479 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2480
2481 mutex_unlock(&sessions_mutex);
2482
2483 return event_notifier_enabler;
2484 }
2485
2486 int lttng_event_notifier_enabler_enable(
2487 struct lttng_event_notifier_enabler *event_notifier_enabler)
2488 {
2489 mutex_lock(&sessions_mutex);
2490 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2491 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2492 mutex_unlock(&sessions_mutex);
2493 return 0;
2494 }
2495
2496 int lttng_event_notifier_enabler_disable(
2497 struct lttng_event_notifier_enabler *event_notifier_enabler)
2498 {
2499 mutex_lock(&sessions_mutex);
2500 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2501 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2502 mutex_unlock(&sessions_mutex);
2503 return 0;
2504 }
2505
2506 int lttng_event_notifier_enabler_attach_filter_bytecode(
2507 struct lttng_event_notifier_enabler *event_notifier_enabler,
2508 struct lttng_kernel_filter_bytecode __user *bytecode)
2509 {
2510 int ret;
2511
2512 ret = lttng_enabler_attach_filter_bytecode(
2513 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler),
2514 bytecode);
2515 if (ret)
2516 goto error;
2517
2518 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2519 return 0;
2520
2521 error:
2522 return ret;
2523 }
2524
2525 int lttng_event_notifier_enabler_attach_capture_bytecode(
2526 struct lttng_event_notifier_enabler *event_notifier_enabler,
2527 struct lttng_kernel_capture_bytecode __user *bytecode)
2528 {
2529 struct lttng_bytecode_node *bytecode_node;
2530 struct lttng_enabler *enabler =
2531 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2532 uint32_t bytecode_len;
2533 int ret;
2534
2535 ret = get_user(bytecode_len, &bytecode->len);
2536 if (ret)
2537 return ret;
2538
2539 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2540 GFP_KERNEL);
2541 if (!bytecode_node)
2542 return -ENOMEM;
2543
2544 ret = copy_from_user(&bytecode_node->bc, bytecode,
2545 sizeof(*bytecode) + bytecode_len);
2546 if (ret)
2547 goto error_free;
2548
2549 bytecode_node->type = LTTNG_BYTECODE_NODE_TYPE_CAPTURE;
2550 bytecode_node->enabler = enabler;
2551
2552 /* Enforce length based on allocated size */
2553 bytecode_node->bc.len = bytecode_len;
2554 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2555
2556 event_notifier_enabler->num_captures++;
2557
2558 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2559 goto end;
2560
2561 error_free:
2562 lttng_kvfree(bytecode_node);
2563 end:
2564 return ret;
2565 }
2566
2567 int lttng_event_notifier_add_callsite(struct lttng_event_notifier *event_notifier,
2568 struct lttng_kernel_event_callsite __user *callsite)
2569 {
2570
2571 switch (event_notifier->instrumentation) {
2572 case LTTNG_KERNEL_UPROBE:
2573 return lttng_uprobes_event_notifier_add_callsite(event_notifier,
2574 callsite);
2575 default:
2576 return -EINVAL;
2577 }
2578 }
2579
2580 int lttng_event_notifier_enabler_attach_context(
2581 struct lttng_event_notifier_enabler *event_notifier_enabler,
2582 struct lttng_kernel_context *context_param)
2583 {
2584 return -ENOSYS;
2585 }
2586
2587 static
2588 void lttng_event_notifier_enabler_destroy(
2589 struct lttng_event_notifier_enabler *event_notifier_enabler)
2590 {
2591 if (!event_notifier_enabler) {
2592 return;
2593 }
2594
2595 list_del(&event_notifier_enabler->node);
2596
2597 lttng_enabler_destroy(lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2598 kfree(event_notifier_enabler);
2599 }
2600
2601 /*
2602 * lttng_session_sync_event_enablers should be called just before starting a
2603 * session.
2604 * Should be called with sessions mutex held.
2605 */
2606 static
2607 void lttng_session_sync_event_enablers(struct lttng_session *session)
2608 {
2609 struct lttng_event_enabler *event_enabler;
2610 struct lttng_event *event;
2611
2612 list_for_each_entry(event_enabler, &session->enablers_head, node)
2613 lttng_event_enabler_ref_events(event_enabler);
2614 /*
2615 * For each event, if at least one of its enablers is enabled,
2616 * and its channel and session transient states are enabled, we
2617 * enable the event, else we disable it.
2618 */
2619 list_for_each_entry(event, &session->events, list) {
2620 struct lttng_enabler_ref *enabler_ref;
2621 struct lttng_bytecode_runtime *runtime;
2622 int enabled = 0, has_enablers_without_bytecode = 0;
2623
2624 switch (event->instrumentation) {
2625 case LTTNG_KERNEL_TRACEPOINT:
2626 case LTTNG_KERNEL_SYSCALL:
2627 /* Enable events */
2628 list_for_each_entry(enabler_ref,
2629 &event->enablers_ref_head, node) {
2630 if (enabler_ref->ref->enabled) {
2631 enabled = 1;
2632 break;
2633 }
2634 }
2635 break;
2636 default:
2637 /* Not handled with lazy sync. */
2638 continue;
2639 }
2640 /*
2641 * Enabled state is based on union of enablers, with
2642 * intesection of session and channel transient enable
2643 * states.
2644 */
2645 enabled = enabled && session->tstate && event->chan->tstate;
2646
2647 WRITE_ONCE(event->enabled, enabled);
2648 /*
2649 * Sync tracepoint registration with event enabled
2650 * state.
2651 */
2652 if (enabled) {
2653 register_event(event);
2654 } else {
2655 _lttng_event_unregister(event);
2656 }
2657
2658 /* Check if has enablers without bytecode enabled */
2659 list_for_each_entry(enabler_ref,
2660 &event->enablers_ref_head, node) {
2661 if (enabler_ref->ref->enabled
2662 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2663 has_enablers_without_bytecode = 1;
2664 break;
2665 }
2666 }
2667 event->has_enablers_without_bytecode =
2668 has_enablers_without_bytecode;
2669
2670 /* Enable filters */
2671 list_for_each_entry(runtime,
2672 &event->filter_bytecode_runtime_head, node)
2673 lttng_bytecode_filter_sync_state(runtime);
2674 }
2675 }
2676
2677 /*
2678 * Apply enablers to session events, adding events to session if need
2679 * be. It is required after each modification applied to an active
2680 * session, and right before session "start".
2681 * "lazy" sync means we only sync if required.
2682 * Should be called with sessions mutex held.
2683 */
2684 static
2685 void lttng_session_lazy_sync_event_enablers(struct lttng_session *session)
2686 {
2687 /* We can skip if session is not active */
2688 if (!session->active)
2689 return;
2690 lttng_session_sync_event_enablers(session);
2691 }
2692
2693 static
2694 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2695 {
2696 struct lttng_event_notifier_enabler *event_notifier_enabler;
2697 struct lttng_event_notifier *event_notifier;
2698
2699 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head, node)
2700 lttng_event_notifier_enabler_ref_event_notifiers(event_notifier_enabler);
2701
2702 /*
2703 * For each event_notifier, if at least one of its enablers is enabled,
2704 * we enable the event_notifier, else we disable it.
2705 */
2706 list_for_each_entry(event_notifier, &event_notifier_group->event_notifiers_head, list) {
2707 struct lttng_enabler_ref *enabler_ref;
2708 struct lttng_bytecode_runtime *runtime;
2709 int enabled = 0, has_enablers_without_bytecode = 0;
2710
2711 switch (event_notifier->instrumentation) {
2712 case LTTNG_KERNEL_TRACEPOINT:
2713 case LTTNG_KERNEL_SYSCALL:
2714 /* Enable event_notifiers */
2715 list_for_each_entry(enabler_ref,
2716 &event_notifier->enablers_ref_head, node) {
2717 if (enabler_ref->ref->enabled) {
2718 enabled = 1;
2719 break;
2720 }
2721 }
2722 break;
2723 default:
2724 /* Not handled with sync. */
2725 continue;
2726 }
2727
2728 WRITE_ONCE(event_notifier->enabled, enabled);
2729 /*
2730 * Sync tracepoint registration with event_notifier enabled
2731 * state.
2732 */
2733 if (enabled) {
2734 if (!event_notifier->registered)
2735 register_event_notifier(event_notifier);
2736 } else {
2737 if (event_notifier->registered)
2738 _lttng_event_notifier_unregister(event_notifier);
2739 }
2740
2741 /* Check if has enablers without bytecode enabled */
2742 list_for_each_entry(enabler_ref,
2743 &event_notifier->enablers_ref_head, node) {
2744 if (enabler_ref->ref->enabled
2745 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2746 has_enablers_without_bytecode = 1;
2747 break;
2748 }
2749 }
2750 event_notifier->has_enablers_without_bytecode =
2751 has_enablers_without_bytecode;
2752
2753 /* Enable filters */
2754 list_for_each_entry(runtime,
2755 &event_notifier->filter_bytecode_runtime_head, node)
2756 lttng_bytecode_filter_sync_state(runtime);
2757
2758 /* Enable captures */
2759 list_for_each_entry(runtime,
2760 &event_notifier->capture_bytecode_runtime_head, node)
2761 lttng_bytecode_capture_sync_state(runtime);
2762 }
2763 }
2764
2765 /*
2766 * Serialize at most one packet worth of metadata into a metadata
2767 * channel.
2768 * We grab the metadata cache mutex to get exclusive access to our metadata
2769 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2770 * allows us to do racy operations such as looking for remaining space left in
2771 * packet and write, since mutual exclusion protects us from concurrent writes.
2772 * Mutual exclusion on the metadata cache allow us to read the cache content
2773 * without racing against reallocation of the cache by updates.
2774 * Returns the number of bytes written in the channel, 0 if no data
2775 * was written and a negative value on error.
2776 */
2777 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2778 struct channel *chan, bool *coherent)
2779 {
2780 struct lib_ring_buffer_ctx ctx;
2781 int ret = 0;
2782 size_t len, reserve_len;
2783
2784 /*
2785 * Ensure we support mutiple get_next / put sequences followed by
2786 * put_next. The metadata cache lock protects reading the metadata
2787 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2788 * "flush" operations on the buffer invoked by different processes.
2789 * Moreover, since the metadata cache memory can be reallocated, we
2790 * need to have exclusive access against updates even though we only
2791 * read it.
2792 */
2793 mutex_lock(&stream->metadata_cache->lock);
2794 WARN_ON(stream->metadata_in < stream->metadata_out);
2795 if (stream->metadata_in != stream->metadata_out)
2796 goto end;
2797
2798 /* Metadata regenerated, change the version. */
2799 if (stream->metadata_cache->version != stream->version)
2800 stream->version = stream->metadata_cache->version;
2801
2802 len = stream->metadata_cache->metadata_written -
2803 stream->metadata_in;
2804 if (!len)
2805 goto end;
2806 reserve_len = min_t(size_t,
2807 stream->transport->ops.packet_avail_size(chan),
2808 len);
2809 lib_ring_buffer_ctx_init(&ctx, chan, NULL, reserve_len,
2810 sizeof(char), -1);
2811 /*
2812 * If reservation failed, return an error to the caller.
2813 */
2814 ret = stream->transport->ops.event_reserve(&ctx, 0);
2815 if (ret != 0) {
2816 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2817 stream->coherent = false;
2818 goto end;
2819 }
2820 stream->transport->ops.event_write(&ctx,
2821 stream->metadata_cache->data + stream->metadata_in,
2822 reserve_len);
2823 stream->transport->ops.event_commit(&ctx);
2824 stream->metadata_in += reserve_len;
2825 if (reserve_len < len)
2826 stream->coherent = false;
2827 else
2828 stream->coherent = true;
2829 ret = reserve_len;
2830
2831 end:
2832 if (coherent)
2833 *coherent = stream->coherent;
2834 mutex_unlock(&stream->metadata_cache->lock);
2835 return ret;
2836 }
2837
2838 static
2839 void lttng_metadata_begin(struct lttng_session *session)
2840 {
2841 if (atomic_inc_return(&session->metadata_cache->producing) == 1)
2842 mutex_lock(&session->metadata_cache->lock);
2843 }
2844
2845 static
2846 void lttng_metadata_end(struct lttng_session *session)
2847 {
2848 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
2849 if (atomic_dec_return(&session->metadata_cache->producing) == 0) {
2850 struct lttng_metadata_stream *stream;
2851
2852 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
2853 wake_up_interruptible(&stream->read_wait);
2854 mutex_unlock(&session->metadata_cache->lock);
2855 }
2856 }
2857
2858 /*
2859 * Write the metadata to the metadata cache.
2860 * Must be called with sessions_mutex held.
2861 * The metadata cache lock protects us from concurrent read access from
2862 * thread outputting metadata content to ring buffer.
2863 * The content of the printf is printed as a single atomic metadata
2864 * transaction.
2865 */
2866 int lttng_metadata_printf(struct lttng_session *session,
2867 const char *fmt, ...)
2868 {
2869 char *str;
2870 size_t len;
2871 va_list ap;
2872
2873 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
2874
2875 va_start(ap, fmt);
2876 str = kvasprintf(GFP_KERNEL, fmt, ap);
2877 va_end(ap);
2878 if (!str)
2879 return -ENOMEM;
2880
2881 len = strlen(str);
2882 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
2883 if (session->metadata_cache->metadata_written + len >
2884 session->metadata_cache->cache_alloc) {
2885 char *tmp_cache_realloc;
2886 unsigned int tmp_cache_alloc_size;
2887
2888 tmp_cache_alloc_size = max_t(unsigned int,
2889 session->metadata_cache->cache_alloc + len,
2890 session->metadata_cache->cache_alloc << 1);
2891 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
2892 if (!tmp_cache_realloc)
2893 goto err;
2894 if (session->metadata_cache->data) {
2895 memcpy(tmp_cache_realloc,
2896 session->metadata_cache->data,
2897 session->metadata_cache->cache_alloc);
2898 vfree(session->metadata_cache->data);
2899 }
2900
2901 session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
2902 session->metadata_cache->data = tmp_cache_realloc;
2903 }
2904 memcpy(session->metadata_cache->data +
2905 session->metadata_cache->metadata_written,
2906 str, len);
2907 session->metadata_cache->metadata_written += len;
2908 kfree(str);
2909
2910 return 0;
2911
2912 err:
2913 kfree(str);
2914 return -ENOMEM;
2915 }
2916
2917 static
2918 int print_tabs(struct lttng_session *session, size_t nesting)
2919 {
2920 size_t i;
2921
2922 for (i = 0; i < nesting; i++) {
2923 int ret;
2924
2925 ret = lttng_metadata_printf(session, " ");
2926 if (ret) {
2927 return ret;
2928 }
2929 }
2930 return 0;
2931 }
2932
2933 static
2934 int lttng_field_name_statedump(struct lttng_session *session,
2935 const struct lttng_event_field *field,
2936 size_t nesting)
2937 {
2938 return lttng_metadata_printf(session, " _%s;\n", field->name);
2939 }
2940
2941 static
2942 int _lttng_integer_type_statedump(struct lttng_session *session,
2943 const struct lttng_type *type,
2944 size_t nesting)
2945 {
2946 int ret;
2947
2948 WARN_ON_ONCE(type->atype != atype_integer);
2949 ret = print_tabs(session, nesting);
2950 if (ret)
2951 return ret;
2952 ret = lttng_metadata_printf(session,
2953 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
2954 type->u.integer.size,
2955 type->u.integer.alignment,
2956 type->u.integer.signedness,
2957 (type->u.integer.encoding == lttng_encode_none)
2958 ? "none"
2959 : (type->u.integer.encoding == lttng_encode_UTF8)
2960 ? "UTF8"
2961 : "ASCII",
2962 type->u.integer.base,
2963 #if __BYTE_ORDER == __BIG_ENDIAN
2964 type->u.integer.reverse_byte_order ? " byte_order = le;" : ""
2965 #else
2966 type->u.integer.reverse_byte_order ? " byte_order = be;" : ""
2967 #endif
2968 );
2969 return ret;
2970 }
2971
2972 /*
2973 * Must be called with sessions_mutex held.
2974 */
2975 static
2976 int _lttng_struct_type_statedump(struct lttng_session *session,
2977 const struct lttng_type *type,
2978 size_t nesting)
2979 {
2980 int ret;
2981 uint32_t i, nr_fields;
2982 unsigned int alignment;
2983
2984 WARN_ON_ONCE(type->atype != atype_struct_nestable);
2985
2986 ret = print_tabs(session, nesting);
2987 if (ret)
2988 return ret;
2989 ret = lttng_metadata_printf(session,
2990 "struct {\n");
2991 if (ret)
2992 return ret;
2993 nr_fields = type->u.struct_nestable.nr_fields;
2994 for (i = 0; i < nr_fields; i++) {
2995 const struct lttng_event_field *iter_field;
2996
2997 iter_field = &type->u.struct_nestable.fields[i];
2998 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
2999 if (ret)
3000 return ret;
3001 }
3002 ret = print_tabs(session, nesting);
3003 if (ret)
3004 return ret;
3005 alignment = type->u.struct_nestable.alignment;
3006 if (alignment) {
3007 ret = lttng_metadata_printf(session,
3008 "} align(%u)",
3009 alignment);
3010 } else {
3011 ret = lttng_metadata_printf(session,
3012 "}");
3013 }
3014 return ret;
3015 }
3016
3017 /*
3018 * Must be called with sessions_mutex held.
3019 */
3020 static
3021 int _lttng_struct_field_statedump(struct lttng_session *session,
3022 const struct lttng_event_field *field,
3023 size_t nesting)
3024 {
3025 int ret;
3026
3027 ret = _lttng_struct_type_statedump(session,
3028 &field->type, nesting);
3029 if (ret)
3030 return ret;
3031 return lttng_field_name_statedump(session, field, nesting);
3032 }
3033
3034 /*
3035 * Must be called with sessions_mutex held.
3036 */
3037 static
3038 int _lttng_variant_type_statedump(struct lttng_session *session,
3039 const struct lttng_type *type,
3040 size_t nesting)
3041 {
3042 int ret;
3043 uint32_t i, nr_choices;
3044
3045 WARN_ON_ONCE(type->atype != atype_variant_nestable);
3046 /*
3047 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3048 */
3049 if (type->u.variant_nestable.alignment != 0)
3050 return -EINVAL;
3051 ret = print_tabs(session, nesting);
3052 if (ret)
3053 return ret;
3054 ret = lttng_metadata_printf(session,
3055 "variant <_%s> {\n",
3056 type->u.variant_nestable.tag_name);
3057 if (ret)
3058 return ret;
3059 nr_choices = type->u.variant_nestable.nr_choices;
3060 for (i = 0; i < nr_choices; i++) {
3061 const struct lttng_event_field *iter_field;
3062
3063 iter_field = &type->u.variant_nestable.choices[i];
3064 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
3065 if (ret)
3066 return ret;
3067 }
3068 ret = print_tabs(session, nesting);
3069 if (ret)
3070 return ret;
3071 ret = lttng_metadata_printf(session,
3072 "}");
3073 return ret;
3074 }
3075
3076 /*
3077 * Must be called with sessions_mutex held.
3078 */
3079 static
3080 int _lttng_variant_field_statedump(struct lttng_session *session,
3081 const struct lttng_event_field *field,
3082 size_t nesting)
3083 {
3084 int ret;
3085
3086 ret = _lttng_variant_type_statedump(session,
3087 &field->type, nesting);
3088 if (ret)
3089 return ret;
3090 return lttng_field_name_statedump(session, field, nesting);
3091 }
3092
3093 /*
3094 * Must be called with sessions_mutex held.
3095 */
3096 static
3097 int _lttng_array_field_statedump(struct lttng_session *session,
3098 const struct lttng_event_field *field,
3099 size_t nesting)
3100 {
3101 int ret;
3102 const struct lttng_type *elem_type;
3103
3104 WARN_ON_ONCE(field->type.atype != atype_array_nestable);
3105
3106 if (field->type.u.array_nestable.alignment) {
3107 ret = print_tabs(session, nesting);
3108 if (ret)
3109 return ret;
3110 ret = lttng_metadata_printf(session,
3111 "struct { } align(%u) _%s_padding;\n",
3112 field->type.u.array_nestable.alignment * CHAR_BIT,
3113 field->name);
3114 if (ret)
3115 return ret;
3116 }
3117 /*
3118 * Nested compound types: Only array of structures and variants are
3119 * currently supported.
3120 */
3121 elem_type = field->type.u.array_nestable.elem_type;
3122 switch (elem_type->atype) {
3123 case atype_integer:
3124 case atype_struct_nestable:
3125 case atype_variant_nestable:
3126 ret = _lttng_type_statedump(session, elem_type, nesting);
3127 if (ret)
3128 return ret;
3129 break;
3130
3131 default:
3132 return -EINVAL;
3133 }
3134 ret = lttng_metadata_printf(session,
3135 " _%s[%u];\n",
3136 field->name,
3137 field->type.u.array_nestable.length);
3138 return ret;
3139 }
3140
3141 /*
3142 * Must be called with sessions_mutex held.
3143 */
3144 static
3145 int _lttng_sequence_field_statedump(struct lttng_session *session,
3146 const struct lttng_event_field *field,
3147 size_t nesting)
3148 {
3149 int ret;
3150 const char *length_name;
3151 const struct lttng_type *elem_type;
3152
3153 WARN_ON_ONCE(field->type.atype != atype_sequence_nestable);
3154
3155 length_name = field->type.u.sequence_nestable.length_name;
3156
3157 if (field->type.u.sequence_nestable.alignment) {
3158 ret = print_tabs(session, nesting);
3159 if (ret)
3160 return ret;
3161 ret = lttng_metadata_printf(session,
3162 "struct { } align(%u) _%s_padding;\n",
3163 field->type.u.sequence_nestable.alignment * CHAR_BIT,
3164 field->name);
3165 if (ret)
3166 return ret;
3167 }
3168
3169 /*
3170 * Nested compound types: Only array of structures and variants are
3171 * currently supported.
3172 */
3173 elem_type = field->type.u.sequence_nestable.elem_type;
3174 switch (elem_type->atype) {
3175 case atype_integer:
3176 case atype_struct_nestable:
3177 case atype_variant_nestable:
3178 ret = _lttng_type_statedump(session, elem_type, nesting);
3179 if (ret)
3180 return ret;
3181 break;
3182
3183 default:
3184 return -EINVAL;
3185 }
3186 ret = lttng_metadata_printf(session,
3187 " _%s[ _%s ];\n",
3188 field->name,
3189 field->type.u.sequence_nestable.length_name);
3190 return ret;
3191 }
3192
3193 /*
3194 * Must be called with sessions_mutex held.
3195 */
3196 static
3197 int _lttng_enum_type_statedump(struct lttng_session *session,
3198 const struct lttng_type *type,
3199 size_t nesting)
3200 {
3201 const struct lttng_enum_desc *enum_desc;
3202 const struct lttng_type *container_type;
3203 int ret;
3204 unsigned int i, nr_entries;
3205
3206 container_type = type->u.enum_nestable.container_type;
3207 if (container_type->atype != atype_integer) {
3208 ret = -EINVAL;
3209 goto end;
3210 }
3211 enum_desc = type->u.enum_nestable.desc;
3212 nr_entries = enum_desc->nr_entries;
3213
3214 ret = print_tabs(session, nesting);
3215 if (ret)
3216 goto end;
3217 ret = lttng_metadata_printf(session, "enum : ");
3218 if (ret)
3219 goto end;
3220 ret = _lttng_integer_type_statedump(session, container_type, 0);
3221 if (ret)
3222 goto end;
3223 ret = lttng_metadata_printf(session, " {\n");
3224 if (ret)
3225 goto end;
3226 /* Dump all entries */
3227 for (i = 0; i < nr_entries; i++) {
3228 const struct lttng_enum_entry *entry = &enum_desc->entries[i];
3229 int j, len;
3230
3231 ret = print_tabs(session, nesting + 1);
3232 if (ret)
3233 goto end;
3234 ret = lttng_metadata_printf(session,
3235 "\"");
3236 if (ret)
3237 goto end;
3238 len = strlen(entry->string);
3239 /* Escape the character '"' */
3240 for (j = 0; j < len; j++) {
3241 char c = entry->string[j];
3242
3243 switch (c) {
3244 case '"':
3245 ret = lttng_metadata_printf(session,
3246 "\\\"");
3247 break;
3248 case '\\':
3249 ret = lttng_metadata_printf(session,
3250 "\\\\");
3251 break;
3252 default:
3253 ret = lttng_metadata_printf(session,
3254 "%c", c);
3255 break;
3256 }
3257 if (ret)
3258 goto end;
3259 }
3260 ret = lttng_metadata_printf(session, "\"");
3261 if (ret)
3262 goto end;
3263
3264 if (entry->options.is_auto) {
3265 ret = lttng_metadata_printf(session, ",\n");
3266 if (ret)
3267 goto end;
3268 } else {
3269 ret = lttng_metadata_printf(session,
3270 " = ");
3271 if (ret)
3272 goto end;
3273 if (entry->start.signedness)
3274 ret = lttng_metadata_printf(session,
3275 "%lld", (long long) entry->start.value);
3276 else
3277 ret = lttng_metadata_printf(session,
3278 "%llu", entry->start.value);
3279 if (ret)
3280 goto end;
3281 if (entry->start.signedness == entry->end.signedness &&
3282 entry->start.value
3283 == entry->end.value) {
3284 ret = lttng_metadata_printf(session,
3285 ",\n");
3286 } else {
3287 if (entry->end.signedness) {
3288 ret = lttng_metadata_printf(session,
3289 " ... %lld,\n",
3290 (long long) entry->end.value);
3291 } else {
3292 ret = lttng_metadata_printf(session,
3293 " ... %llu,\n",
3294 entry->end.value);
3295 }
3296 }
3297 if (ret)
3298 goto end;
3299 }
3300 }
3301 ret = print_tabs(session, nesting);
3302 if (ret)
3303 goto end;
3304 ret = lttng_metadata_printf(session, "}");
3305 end:
3306 return ret;
3307 }
3308
3309 /*
3310 * Must be called with sessions_mutex held.
3311 */
3312 static
3313 int _lttng_enum_field_statedump(struct lttng_session *session,
3314 const struct lttng_event_field *field,
3315 size_t nesting)
3316 {
3317 int ret;
3318
3319 ret = _lttng_enum_type_statedump(session, &field->type, nesting);
3320 if (ret)
3321 return ret;
3322 return lttng_field_name_statedump(session, field, nesting);
3323 }
3324
3325 static
3326 int _lttng_integer_field_statedump(struct lttng_session *session,
3327 const struct lttng_event_field *field,
3328 size_t nesting)
3329 {
3330 int ret;
3331
3332 ret = _lttng_integer_type_statedump(session, &field->type, nesting);
3333 if (ret)
3334 return ret;
3335 return lttng_field_name_statedump(session, field, nesting);
3336 }
3337
3338 static
3339 int _lttng_string_type_statedump(struct lttng_session *session,
3340 const struct lttng_type *type,
3341 size_t nesting)
3342 {
3343 int ret;
3344
3345 WARN_ON_ONCE(type->atype != atype_string);
3346 /* Default encoding is UTF8 */
3347 ret = print_tabs(session, nesting);
3348 if (ret)
3349 return ret;
3350 ret = lttng_metadata_printf(session,
3351 "string%s",
3352 type->u.string.encoding == lttng_encode_ASCII ?
3353 " { encoding = ASCII; }" : "");
3354 return ret;
3355 }
3356
3357 static
3358 int _lttng_string_field_statedump(struct lttng_session *session,
3359 const struct lttng_event_field *field,
3360 size_t nesting)
3361 {
3362 int ret;
3363
3364 WARN_ON_ONCE(field->type.atype != atype_string);
3365 ret = _lttng_string_type_statedump(session, &field->type, nesting);
3366 if (ret)
3367 return ret;
3368 return lttng_field_name_statedump(session, field, nesting);
3369 }
3370
3371 /*
3372 * Must be called with sessions_mutex held.
3373 */
3374 static
3375 int _lttng_type_statedump(struct lttng_session *session,
3376 const struct lttng_type *type,
3377 size_t nesting)
3378 {
3379 int ret = 0;
3380
3381 switch (type->atype) {
3382 case atype_integer:
3383 ret = _lttng_integer_type_statedump(session, type, nesting);
3384 break;
3385 case atype_enum_nestable:
3386 ret = _lttng_enum_type_statedump(session, type, nesting);
3387 break;
3388 case atype_string:
3389 ret = _lttng_string_type_statedump(session, type, nesting);
3390 break;
3391 case atype_struct_nestable:
3392 ret = _lttng_struct_type_statedump(session, type, nesting);
3393 break;
3394 case atype_variant_nestable:
3395 ret = _lttng_variant_type_statedump(session, type, nesting);
3396 break;
3397
3398 /* Nested arrays and sequences are not supported yet. */
3399 case atype_array_nestable:
3400 case atype_sequence_nestable:
3401 default:
3402 WARN_ON_ONCE(1);
3403 return -EINVAL;
3404 }
3405 return ret;
3406 }
3407
3408 /*
3409 * Must be called with sessions_mutex held.
3410 */
3411 static
3412 int _lttng_field_statedump(struct lttng_session *session,
3413 const struct lttng_event_field *field,
3414 size_t nesting)
3415 {
3416 int ret = 0;
3417
3418 switch (field->type.atype) {
3419 case atype_integer:
3420 ret = _lttng_integer_field_statedump(session, field, nesting);
3421 break;
3422 case atype_enum_nestable:
3423 ret = _lttng_enum_field_statedump(session, field, nesting);
3424 break;
3425 case atype_string:
3426 ret = _lttng_string_field_statedump(session, field, nesting);
3427 break;
3428 case atype_struct_nestable:
3429 ret = _lttng_struct_field_statedump(session, field, nesting);
3430 break;
3431 case atype_array_nestable:
3432 ret = _lttng_array_field_statedump(session, field, nesting);
3433 break;
3434 case atype_sequence_nestable:
3435 ret = _lttng_sequence_field_statedump(session, field, nesting);
3436 break;
3437 case atype_variant_nestable:
3438 ret = _lttng_variant_field_statedump(session, field, nesting);
3439 break;
3440
3441 default:
3442 WARN_ON_ONCE(1);
3443 return -EINVAL;
3444 }
3445 return ret;
3446 }
3447
3448 static
3449 int _lttng_context_metadata_statedump(struct lttng_session *session,
3450 struct lttng_ctx *ctx)
3451 {
3452 int ret = 0;
3453 int i;
3454
3455 if (!ctx)
3456 return 0;
3457 for (i = 0; i < ctx->nr_fields; i++) {
3458 const struct lttng_ctx_field *field = &ctx->fields[i];
3459
3460 ret = _lttng_field_statedump(session, &field->event_field, 2);
3461 if (ret)
3462 return ret;
3463 }
3464 return ret;
3465 }
3466
3467 static
3468 int _lttng_fields_metadata_statedump(struct lttng_session *session,
3469 struct lttng_event *event)
3470 {
3471 const struct lttng_event_desc *desc = event->desc;
3472 int ret = 0;
3473 int i;
3474
3475 for (i = 0; i < desc->nr_fields; i++) {
3476 const struct lttng_event_field *field = &desc->fields[i];
3477
3478 ret = _lttng_field_statedump(session, field, 2);
3479 if (ret)
3480 return ret;
3481 }
3482 return ret;
3483 }
3484
3485 /*
3486 * Must be called with sessions_mutex held.
3487 * The entire event metadata is printed as a single atomic metadata
3488 * transaction.
3489 */
3490 static
3491 int _lttng_event_metadata_statedump(struct lttng_session *session,
3492 struct lttng_channel *chan,
3493 struct lttng_event *event)
3494 {
3495 int ret = 0;
3496
3497 if (event->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3498 return 0;
3499 if (chan->channel_type == METADATA_CHANNEL)
3500 return 0;
3501
3502 lttng_metadata_begin(session);
3503
3504 ret = lttng_metadata_printf(session,
3505 "event {\n"
3506 " name = \"%s\";\n"
3507 " id = %u;\n"
3508 " stream_id = %u;\n",
3509 event->desc->name,
3510 event->id,
3511 event->chan->id);
3512 if (ret)
3513 goto end;
3514
3515 if (event->ctx) {
3516 ret = lttng_metadata_printf(session,
3517 " context := struct {\n");
3518 if (ret)
3519 goto end;
3520 }
3521 ret = _lttng_context_metadata_statedump(session, event->ctx);
3522 if (ret)
3523 goto end;
3524 if (event->ctx) {
3525 ret = lttng_metadata_printf(session,
3526 " };\n");
3527 if (ret)
3528 goto end;
3529 }
3530
3531 ret = lttng_metadata_printf(session,
3532 " fields := struct {\n"
3533 );
3534 if (ret)
3535 goto end;
3536
3537 ret = _lttng_fields_metadata_statedump(session, event);
3538 if (ret)
3539 goto end;
3540
3541 /*
3542 * LTTng space reservation can only reserve multiples of the
3543 * byte size.
3544 */
3545 ret = lttng_metadata_printf(session,
3546 " };\n"
3547 "};\n\n");
3548 if (ret)
3549 goto end;
3550
3551 event->metadata_dumped = 1;
3552 end:
3553 lttng_metadata_end(session);
3554 return ret;
3555
3556 }
3557
3558 /*
3559 * Must be called with sessions_mutex held.
3560 * The entire channel metadata is printed as a single atomic metadata
3561 * transaction.
3562 */
3563 static
3564 int _lttng_channel_metadata_statedump(struct lttng_session *session,
3565 struct lttng_channel *chan)
3566 {
3567 int ret = 0;
3568
3569 if (chan->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3570 return 0;
3571
3572 if (chan->channel_type == METADATA_CHANNEL)
3573 return 0;
3574
3575 lttng_metadata_begin(session);
3576
3577 WARN_ON_ONCE(!chan->header_type);
3578 ret = lttng_metadata_printf(session,
3579 "stream {\n"
3580 " id = %u;\n"
3581 " event.header := %s;\n"
3582 " packet.context := struct packet_context;\n",
3583 chan->id,
3584 chan->header_type == 1 ? "struct event_header_compact" :
3585 "struct event_header_large");
3586 if (ret)
3587 goto end;
3588
3589 if (chan->ctx) {
3590 ret = lttng_metadata_printf(session,
3591 " event.context := struct {\n");
3592 if (ret)
3593 goto end;
3594 }
3595 ret = _lttng_context_metadata_statedump(session, chan->ctx);
3596 if (ret)
3597 goto end;
3598 if (chan->ctx) {
3599 ret = lttng_metadata_printf(session,
3600 " };\n");
3601 if (ret)
3602 goto end;
3603 }
3604
3605 ret = lttng_metadata_printf(session,
3606 "};\n\n");
3607
3608 chan->metadata_dumped = 1;
3609 end:
3610 lttng_metadata_end(session);
3611 return ret;
3612 }
3613
3614 /*
3615 * Must be called with sessions_mutex held.
3616 */
3617 static
3618 int _lttng_stream_packet_context_declare(struct lttng_session *session)
3619 {
3620 return lttng_metadata_printf(session,
3621 "struct packet_context {\n"
3622 " uint64_clock_monotonic_t timestamp_begin;\n"
3623 " uint64_clock_monotonic_t timestamp_end;\n"
3624 " uint64_t content_size;\n"
3625 " uint64_t packet_size;\n"
3626 " uint64_t packet_seq_num;\n"
3627 " unsigned long events_discarded;\n"
3628 " uint32_t cpu_id;\n"
3629 "};\n\n"
3630 );
3631 }
3632
3633 /*
3634 * Compact header:
3635 * id: range: 0 - 30.
3636 * id 31 is reserved to indicate an extended header.
3637 *
3638 * Large header:
3639 * id: range: 0 - 65534.
3640 * id 65535 is reserved to indicate an extended header.
3641 *
3642 * Must be called with sessions_mutex held.
3643 */
3644 static
3645 int _lttng_event_header_declare(struct lttng_session *session)
3646 {
3647 return lttng_metadata_printf(session,
3648 "struct event_header_compact {\n"
3649 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3650 " variant <id> {\n"
3651 " struct {\n"
3652 " uint27_clock_monotonic_t timestamp;\n"
3653 " } compact;\n"
3654 " struct {\n"
3655 " uint32_t id;\n"
3656 " uint64_clock_monotonic_t timestamp;\n"
3657 " } extended;\n"
3658 " } v;\n"
3659 "} align(%u);\n"
3660 "\n"
3661 "struct event_header_large {\n"
3662 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3663 " variant <id> {\n"
3664 " struct {\n"
3665 " uint32_clock_monotonic_t timestamp;\n"
3666 " } compact;\n"
3667 " struct {\n"
3668 " uint32_t id;\n"
3669 " uint64_clock_monotonic_t timestamp;\n"
3670 " } extended;\n"
3671 " } v;\n"
3672 "} align(%u);\n\n",
3673 lttng_alignof(uint32_t) * CHAR_BIT,
3674 lttng_alignof(uint16_t) * CHAR_BIT
3675 );
3676 }
3677
3678 /*
3679 * Approximation of NTP time of day to clock monotonic correlation,
3680 * taken at start of trace.
3681 * Yes, this is only an approximation. Yes, we can (and will) do better
3682 * in future versions.
3683 * This function may return a negative offset. It may happen if the
3684 * system sets the REALTIME clock to 0 after boot.
3685 *
3686 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3687 * y2038 compliant.
3688 */
3689 static
3690 int64_t measure_clock_offset(void)
3691 {
3692 uint64_t monotonic_avg, monotonic[2], realtime;
3693 uint64_t tcf = trace_clock_freq();
3694 int64_t offset;
3695 unsigned long flags;
3696 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3697 struct timespec64 rts = { 0, 0 };
3698 #else
3699 struct timespec rts = { 0, 0 };
3700 #endif
3701
3702 /* Disable interrupts to increase correlation precision. */
3703 local_irq_save(flags);
3704 monotonic[0] = trace_clock_read64();
3705 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3706 ktime_get_real_ts64(&rts);
3707 #else
3708 getnstimeofday(&rts);
3709 #endif
3710 monotonic[1] = trace_clock_read64();
3711 local_irq_restore(flags);
3712
3713 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3714 realtime = (uint64_t) rts.tv_sec * tcf;
3715 if (tcf == NSEC_PER_SEC) {
3716 realtime += rts.tv_nsec;
3717 } else {
3718 uint64_t n = rts.tv_nsec * tcf;
3719
3720 do_div(n, NSEC_PER_SEC);
3721 realtime += n;
3722 }
3723 offset = (int64_t) realtime - monotonic_avg;
3724 return offset;
3725 }
3726
3727 static
3728 int print_escaped_ctf_string(struct lttng_session *session, const char *string)
3729 {
3730 int ret = 0;
3731 size_t i;
3732 char cur;
3733
3734 i = 0;
3735 cur = string[i];
3736 while (cur != '\0') {
3737 switch (cur) {
3738 case '\n':
3739 ret = lttng_metadata_printf(session, "%s", "\\n");
3740 break;
3741 case '\\':
3742 case '"':
3743 ret = lttng_metadata_printf(session, "%c", '\\');
3744 if (ret)
3745 goto error;
3746 /* We still print the current char */
3747 /* Fallthrough */
3748 default:
3749 ret = lttng_metadata_printf(session, "%c", cur);
3750 break;
3751 }
3752
3753 if (ret)
3754 goto error;
3755
3756 cur = string[++i];
3757 }
3758 error:
3759 return ret;
3760 }
3761
3762 static
3763 int print_metadata_escaped_field(struct lttng_session *session, const char *field,
3764 const char *field_value)
3765 {
3766 int ret;
3767
3768 ret = lttng_metadata_printf(session, " %s = \"", field);
3769 if (ret)
3770 goto error;
3771
3772 ret = print_escaped_ctf_string(session, field_value);
3773 if (ret)
3774 goto error;
3775
3776 ret = lttng_metadata_printf(session, "\";\n");
3777
3778 error:
3779 return ret;
3780 }
3781
3782 /*
3783 * Output metadata into this session's metadata buffers.
3784 * Must be called with sessions_mutex held.
3785 */
3786 static
3787 int _lttng_session_metadata_statedump(struct lttng_session *session)
3788 {
3789 unsigned char *uuid_c = session->uuid.b;
3790 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3791 const char *product_uuid;
3792 struct lttng_channel *chan;
3793 struct lttng_event *event;
3794 int ret = 0;
3795
3796 if (!LTTNG_READ_ONCE(session->active))
3797 return 0;
3798
3799 lttng_metadata_begin(session);
3800
3801 if (session->metadata_dumped)
3802 goto skip_session;
3803
3804 snprintf(uuid_s, sizeof(uuid_s),
3805 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3806 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3807 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3808 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3809 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3810
3811 ret = lttng_metadata_printf(session,
3812 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3813 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3814 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3815 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3816 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3817 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3818 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3819 "\n"
3820 "trace {\n"
3821 " major = %u;\n"
3822 " minor = %u;\n"
3823 " uuid = \"%s\";\n"
3824 " byte_order = %s;\n"
3825 " packet.header := struct {\n"
3826 " uint32_t magic;\n"
3827 " uint8_t uuid[16];\n"
3828 " uint32_t stream_id;\n"
3829 " uint64_t stream_instance_id;\n"
3830 " };\n"
3831 "};\n\n",
3832 lttng_alignof(uint8_t) * CHAR_BIT,
3833 lttng_alignof(uint16_t) * CHAR_BIT,
3834 lttng_alignof(uint32_t) * CHAR_BIT,
3835 lttng_alignof(uint64_t) * CHAR_BIT,
3836 sizeof(unsigned long) * CHAR_BIT,
3837 lttng_alignof(unsigned long) * CHAR_BIT,
3838 CTF_SPEC_MAJOR,
3839 CTF_SPEC_MINOR,
3840 uuid_s,
3841 #if __BYTE_ORDER == __BIG_ENDIAN
3842 "be"
3843 #else
3844 "le"
3845 #endif
3846 );
3847 if (ret)
3848 goto end;
3849
3850 ret = lttng_metadata_printf(session,
3851 "env {\n"
3852 " hostname = \"%s\";\n"
3853 " domain = \"kernel\";\n"
3854 " sysname = \"%s\";\n"
3855 " kernel_release = \"%s\";\n"
3856 " kernel_version = \"%s\";\n"
3857 " tracer_name = \"lttng-modules\";\n"
3858 " tracer_major = %d;\n"
3859 " tracer_minor = %d;\n"
3860 " tracer_patchlevel = %d;\n"
3861 " trace_buffering_scheme = \"global\";\n",
3862 current->nsproxy->uts_ns->name.nodename,
3863 utsname()->sysname,
3864 utsname()->release,
3865 utsname()->version,
3866 LTTNG_MODULES_MAJOR_VERSION,
3867 LTTNG_MODULES_MINOR_VERSION,
3868 LTTNG_MODULES_PATCHLEVEL_VERSION
3869 );
3870 if (ret)
3871 goto end;
3872
3873 ret = print_metadata_escaped_field(session, "trace_name", session->name);
3874 if (ret)
3875 goto end;
3876 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
3877 session->creation_time);
3878 if (ret)
3879 goto end;
3880
3881 /* Add the product UUID to the 'env' section */
3882 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
3883 if (product_uuid) {
3884 ret = lttng_metadata_printf(session,
3885 " product_uuid = \"%s\";\n",
3886 product_uuid
3887 );
3888 if (ret)
3889 goto end;
3890 }
3891
3892 /* Close the 'env' section */
3893 ret = lttng_metadata_printf(session, "};\n\n");
3894 if (ret)
3895 goto end;
3896
3897 ret = lttng_metadata_printf(session,
3898 "clock {\n"
3899 " name = \"%s\";\n",
3900 trace_clock_name()
3901 );
3902 if (ret)
3903 goto end;
3904
3905 if (!trace_clock_uuid(clock_uuid_s)) {
3906 ret = lttng_metadata_printf(session,
3907 " uuid = \"%s\";\n",
3908 clock_uuid_s
3909 );
3910 if (ret)
3911 goto end;
3912 }
3913
3914 ret = lttng_metadata_printf(session,
3915 " description = \"%s\";\n"
3916 " freq = %llu; /* Frequency, in Hz */\n"
3917 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
3918 " offset = %lld;\n"
3919 "};\n\n",
3920 trace_clock_description(),
3921 (unsigned long long) trace_clock_freq(),
3922 (long long) measure_clock_offset()
3923 );
3924 if (ret)
3925 goto end;
3926
3927 ret = lttng_metadata_printf(session,
3928 "typealias integer {\n"
3929 " size = 27; align = 1; signed = false;\n"
3930 " map = clock.%s.value;\n"
3931 "} := uint27_clock_monotonic_t;\n"
3932 "\n"
3933 "typealias integer {\n"
3934 " size = 32; align = %u; signed = false;\n"
3935 " map = clock.%s.value;\n"
3936 "} := uint32_clock_monotonic_t;\n"
3937 "\n"
3938 "typealias integer {\n"
3939 " size = 64; align = %u; signed = false;\n"
3940 " map = clock.%s.value;\n"
3941 "} := uint64_clock_monotonic_t;\n\n",
3942 trace_clock_name(),
3943 lttng_alignof(uint32_t) * CHAR_BIT,
3944 trace_clock_name(),
3945 lttng_alignof(uint64_t) * CHAR_BIT,
3946 trace_clock_name()
3947 );
3948 if (ret)
3949 goto end;
3950
3951 ret = _lttng_stream_packet_context_declare(session);
3952 if (ret)
3953 goto end;
3954
3955 ret = _lttng_event_header_declare(session);
3956 if (ret)
3957 goto end;
3958
3959 skip_session:
3960 list_for_each_entry(chan, &session->chan, list) {
3961 ret = _lttng_channel_metadata_statedump(session, chan);
3962 if (ret)
3963 goto end;
3964 }
3965
3966 list_for_each_entry(event, &session->events, list) {
3967 ret = _lttng_event_metadata_statedump(session, event->chan, event);
3968 if (ret)
3969 goto end;
3970 }
3971 session->metadata_dumped = 1;
3972 end:
3973 lttng_metadata_end(session);
3974 return ret;
3975 }
3976
3977 /**
3978 * lttng_transport_register - LTT transport registration
3979 * @transport: transport structure
3980 *
3981 * Registers a transport which can be used as output to extract the data out of
3982 * LTTng. The module calling this registration function must ensure that no
3983 * trap-inducing code will be executed by the transport functions. E.g.
3984 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
3985 * is made visible to the transport function. This registration acts as a
3986 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
3987 * after its registration must it synchronize the TLBs.
3988 */
3989 void lttng_transport_register(struct lttng_transport *transport)
3990 {
3991 /*
3992 * Make sure no page fault can be triggered by the module about to be
3993 * registered. We deal with this here so we don't have to call
3994 * vmalloc_sync_mappings() in each module's init.
3995 */
3996 wrapper_vmalloc_sync_mappings();
3997
3998 mutex_lock(&sessions_mutex);
3999 list_add_tail(&transport->node, &lttng_transport_list);
4000 mutex_unlock(&sessions_mutex);
4001 }
4002 EXPORT_SYMBOL_GPL(lttng_transport_register);
4003
4004 /**
4005 * lttng_transport_unregister - LTT transport unregistration
4006 * @transport: transport structure
4007 */
4008 void lttng_transport_unregister(struct lttng_transport *transport)
4009 {
4010 mutex_lock(&sessions_mutex);
4011 list_del(&transport->node);
4012 mutex_unlock(&sessions_mutex);
4013 }
4014 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4015
4016 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4017 {
4018 /*
4019 * Make sure no page fault can be triggered by the module about to be
4020 * registered. We deal with this here so we don't have to call
4021 * vmalloc_sync_mappings() in each module's init.
4022 */
4023 wrapper_vmalloc_sync_mappings();
4024
4025 mutex_lock(&sessions_mutex);
4026 list_add_tail(&transport->node, &lttng_counter_transport_list);
4027 mutex_unlock(&sessions_mutex);
4028 }
4029 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4030
4031 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4032 {
4033 mutex_lock(&sessions_mutex);
4034 list_del(&transport->node);
4035 mutex_unlock(&sessions_mutex);
4036 }
4037 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4038
4039 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4040
4041 enum cpuhp_state lttng_hp_prepare;
4042 enum cpuhp_state lttng_hp_online;
4043
4044 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4045 {
4046 struct lttng_cpuhp_node *lttng_node;
4047
4048 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4049 switch (lttng_node->component) {
4050 case LTTNG_RING_BUFFER_FRONTEND:
4051 return 0;
4052 case LTTNG_RING_BUFFER_BACKEND:
4053 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4054 case LTTNG_RING_BUFFER_ITER:
4055 return 0;
4056 case LTTNG_CONTEXT_PERF_COUNTERS:
4057 return 0;
4058 default:
4059 return -EINVAL;
4060 }
4061 }
4062
4063 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4064 {
4065 struct lttng_cpuhp_node *lttng_node;
4066
4067 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4068 switch (lttng_node->component) {
4069 case LTTNG_RING_BUFFER_FRONTEND:
4070 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4071 case LTTNG_RING_BUFFER_BACKEND:
4072 return 0;
4073 case LTTNG_RING_BUFFER_ITER:
4074 return 0;
4075 case LTTNG_CONTEXT_PERF_COUNTERS:
4076 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4077 default:
4078 return -EINVAL;
4079 }
4080 }
4081
4082 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4083 {
4084 struct lttng_cpuhp_node *lttng_node;
4085
4086 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4087 switch (lttng_node->component) {
4088 case LTTNG_RING_BUFFER_FRONTEND:
4089 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4090 case LTTNG_RING_BUFFER_BACKEND:
4091 return 0;
4092 case LTTNG_RING_BUFFER_ITER:
4093 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4094 case LTTNG_CONTEXT_PERF_COUNTERS:
4095 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4096 default:
4097 return -EINVAL;
4098 }
4099 }
4100
4101 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4102 {
4103 struct lttng_cpuhp_node *lttng_node;
4104
4105 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4106 switch (lttng_node->component) {
4107 case LTTNG_RING_BUFFER_FRONTEND:
4108 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4109 case LTTNG_RING_BUFFER_BACKEND:
4110 return 0;
4111 case LTTNG_RING_BUFFER_ITER:
4112 return 0;
4113 case LTTNG_CONTEXT_PERF_COUNTERS:
4114 return 0;
4115 default:
4116 return -EINVAL;
4117 }
4118 }
4119
4120 static int __init lttng_init_cpu_hotplug(void)
4121 {
4122 int ret;
4123
4124 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4125 lttng_hotplug_prepare,
4126 lttng_hotplug_dead);
4127 if (ret < 0) {
4128 return ret;
4129 }
4130 lttng_hp_prepare = ret;
4131 lttng_rb_set_hp_prepare(ret);
4132
4133 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4134 lttng_hotplug_online,
4135 lttng_hotplug_offline);
4136 if (ret < 0) {
4137 cpuhp_remove_multi_state(lttng_hp_prepare);
4138 lttng_hp_prepare = 0;
4139 return ret;
4140 }
4141 lttng_hp_online = ret;
4142 lttng_rb_set_hp_online(ret);
4143
4144 return 0;
4145 }
4146
4147 static void __exit lttng_exit_cpu_hotplug(void)
4148 {
4149 lttng_rb_set_hp_online(0);
4150 cpuhp_remove_multi_state(lttng_hp_online);
4151 lttng_rb_set_hp_prepare(0);
4152 cpuhp_remove_multi_state(lttng_hp_prepare);
4153 }
4154
4155 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4156 static int lttng_init_cpu_hotplug(void)
4157 {
4158 return 0;
4159 }
4160 static void lttng_exit_cpu_hotplug(void)
4161 {
4162 }
4163 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4164
4165
4166 static int __init lttng_events_init(void)
4167 {
4168 int ret;
4169
4170 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4171 if (ret)
4172 return ret;
4173 ret = wrapper_get_pfnblock_flags_mask_init();
4174 if (ret)
4175 return ret;
4176 ret = wrapper_get_pageblock_flags_mask_init();
4177 if (ret)
4178 return ret;
4179 ret = lttng_probes_init();
4180 if (ret)
4181 return ret;
4182 ret = lttng_context_init();
4183 if (ret)
4184 return ret;
4185 ret = lttng_tracepoint_init();
4186 if (ret)
4187 goto error_tp;
4188 event_cache = KMEM_CACHE(lttng_event, 0);
4189 if (!event_cache) {
4190 ret = -ENOMEM;
4191 goto error_kmem_event;
4192 }
4193 event_notifier_cache = KMEM_CACHE(lttng_event_notifier, 0);
4194 if (!event_notifier_cache) {
4195 ret = -ENOMEM;
4196 goto error_kmem_event_notifier;
4197 }
4198 ret = lttng_abi_init();
4199 if (ret)
4200 goto error_abi;
4201 ret = lttng_logger_init();
4202 if (ret)
4203 goto error_logger;
4204 ret = lttng_init_cpu_hotplug();
4205 if (ret)
4206 goto error_hotplug;
4207 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4208 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4209 __stringify(LTTNG_MODULES_MINOR_VERSION),
4210 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4211 LTTNG_MODULES_EXTRAVERSION,
4212 LTTNG_VERSION_NAME,
4213 #ifdef LTTNG_EXTRA_VERSION_GIT
4214 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4215 #else
4216 "",
4217 #endif
4218 #ifdef LTTNG_EXTRA_VERSION_NAME
4219 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4220 #else
4221 "");
4222 #endif
4223 return 0;
4224
4225 error_hotplug:
4226 lttng_logger_exit();
4227 error_logger:
4228 lttng_abi_exit();
4229 error_abi:
4230 kmem_cache_destroy(event_notifier_cache);
4231 error_kmem_event_notifier:
4232 kmem_cache_destroy(event_cache);
4233 error_kmem_event:
4234 lttng_tracepoint_exit();
4235 error_tp:
4236 lttng_context_exit();
4237 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4238 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4239 __stringify(LTTNG_MODULES_MINOR_VERSION),
4240 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4241 LTTNG_MODULES_EXTRAVERSION,
4242 LTTNG_VERSION_NAME,
4243 #ifdef LTTNG_EXTRA_VERSION_GIT
4244 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4245 #else
4246 "",
4247 #endif
4248 #ifdef LTTNG_EXTRA_VERSION_NAME
4249 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4250 #else
4251 "");
4252 #endif
4253 return ret;
4254 }
4255
4256 module_init(lttng_events_init);
4257
4258 static void __exit lttng_events_exit(void)
4259 {
4260 struct lttng_session *session, *tmpsession;
4261
4262 lttng_exit_cpu_hotplug();
4263 lttng_logger_exit();
4264 lttng_abi_exit();
4265 list_for_each_entry_safe(session, tmpsession, &sessions, list)
4266 lttng_session_destroy(session);
4267 kmem_cache_destroy(event_cache);
4268 kmem_cache_destroy(event_notifier_cache);
4269 lttng_tracepoint_exit();
4270 lttng_context_exit();
4271 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4272 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4273 __stringify(LTTNG_MODULES_MINOR_VERSION),
4274 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4275 LTTNG_MODULES_EXTRAVERSION,
4276 LTTNG_VERSION_NAME,
4277 #ifdef LTTNG_EXTRA_VERSION_GIT
4278 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4279 #else
4280 "",
4281 #endif
4282 #ifdef LTTNG_EXTRA_VERSION_NAME
4283 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4284 #else
4285 "");
4286 #endif
4287 }
4288
4289 module_exit(lttng_events_exit);
4290
4291 #include <generated/patches.h>
4292 #ifdef LTTNG_EXTRA_VERSION_GIT
4293 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4294 #endif
4295 #ifdef LTTNG_EXTRA_VERSION_NAME
4296 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4297 #endif
4298 MODULE_LICENSE("GPL and additional rights");
4299 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4300 MODULE_DESCRIPTION("LTTng tracer");
4301 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4302 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4303 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4304 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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