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