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Fix: timer_expire_entry changed in 4.19.312
[lttng-modules.git] / lttng-events.c
1 /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
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/jhash.h>
28 #include <linux/uaccess.h>
29 #include <linux/vmalloc.h>
30
31 #include <wrapper/uuid.h>
32 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_all() */
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 <wrapper/vzalloc.h>
44 #include <wrapper/ringbuffer/backend.h>
45 #include <wrapper/ringbuffer/frontend.h>
46
47 #define METADATA_CACHE_DEFAULT_SIZE 4096
48
49 static LIST_HEAD(sessions);
50 static LIST_HEAD(lttng_transport_list);
51 /*
52 * Protect the sessions and metadata caches.
53 */
54 static DEFINE_MUTEX(sessions_mutex);
55 static struct kmem_cache *event_cache;
56
57 static void lttng_session_lazy_sync_enablers(struct lttng_session *session);
58 static void lttng_session_sync_enablers(struct lttng_session *session);
59 static void lttng_enabler_destroy(struct lttng_enabler *enabler);
60
61 static void _lttng_event_destroy(struct lttng_event *event);
62 static void _lttng_channel_destroy(struct lttng_channel *chan);
63 static int _lttng_event_unregister(struct lttng_event *event);
64 static
65 int _lttng_event_metadata_statedump(struct lttng_session *session,
66 struct lttng_channel *chan,
67 struct lttng_event *event);
68 static
69 int _lttng_session_metadata_statedump(struct lttng_session *session);
70 static
71 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
72 static
73 int _lttng_field_statedump(struct lttng_session *session,
74 const struct lttng_event_field *field,
75 size_t nesting);
76
77 void synchronize_trace(void)
78 {
79 synchronize_sched();
80 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0))
81 #ifdef CONFIG_PREEMPT_RT_FULL
82 synchronize_rcu();
83 #endif
84 #else /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
85 #ifdef CONFIG_PREEMPT_RT
86 synchronize_rcu();
87 #endif
88 #endif /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
89 }
90
91 void lttng_lock_sessions(void)
92 {
93 mutex_lock(&sessions_mutex);
94 }
95
96 void lttng_unlock_sessions(void)
97 {
98 mutex_unlock(&sessions_mutex);
99 }
100
101 /*
102 * Called with sessions lock held.
103 */
104 int lttng_session_active(void)
105 {
106 struct lttng_session *iter;
107
108 list_for_each_entry(iter, &sessions, list) {
109 if (iter->active)
110 return 1;
111 }
112 return 0;
113 }
114
115 struct lttng_session *lttng_session_create(void)
116 {
117 struct lttng_session *session;
118 struct lttng_metadata_cache *metadata_cache;
119 int i;
120
121 mutex_lock(&sessions_mutex);
122 session = lttng_kvzalloc(sizeof(struct lttng_session), GFP_KERNEL);
123 if (!session)
124 goto err;
125 INIT_LIST_HEAD(&session->chan);
126 INIT_LIST_HEAD(&session->events);
127 uuid_le_gen(&session->uuid);
128
129 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
130 GFP_KERNEL);
131 if (!metadata_cache)
132 goto err_free_session;
133 metadata_cache->data = lttng_vzalloc(METADATA_CACHE_DEFAULT_SIZE);
134 if (!metadata_cache->data)
135 goto err_free_cache;
136 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
137 kref_init(&metadata_cache->refcount);
138 mutex_init(&metadata_cache->lock);
139 session->metadata_cache = metadata_cache;
140 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
141 memcpy(&metadata_cache->uuid, &session->uuid,
142 sizeof(metadata_cache->uuid));
143 INIT_LIST_HEAD(&session->enablers_head);
144 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
145 INIT_HLIST_HEAD(&session->events_ht.table[i]);
146 list_add(&session->list, &sessions);
147 mutex_unlock(&sessions_mutex);
148 return session;
149
150 err_free_cache:
151 kfree(metadata_cache);
152 err_free_session:
153 lttng_kvfree(session);
154 err:
155 mutex_unlock(&sessions_mutex);
156 return NULL;
157 }
158
159 void metadata_cache_destroy(struct kref *kref)
160 {
161 struct lttng_metadata_cache *cache =
162 container_of(kref, struct lttng_metadata_cache, refcount);
163 vfree(cache->data);
164 kfree(cache);
165 }
166
167 void lttng_session_destroy(struct lttng_session *session)
168 {
169 struct lttng_channel *chan, *tmpchan;
170 struct lttng_event *event, *tmpevent;
171 struct lttng_metadata_stream *metadata_stream;
172 struct lttng_enabler *enabler, *tmpenabler;
173 int ret;
174
175 mutex_lock(&sessions_mutex);
176 WRITE_ONCE(session->active, 0);
177 list_for_each_entry(chan, &session->chan, list) {
178 ret = lttng_syscalls_unregister(chan);
179 WARN_ON(ret);
180 }
181 list_for_each_entry(event, &session->events, list) {
182 ret = _lttng_event_unregister(event);
183 WARN_ON(ret);
184 }
185 synchronize_trace(); /* Wait for in-flight events to complete */
186 list_for_each_entry_safe(enabler, tmpenabler,
187 &session->enablers_head, node)
188 lttng_enabler_destroy(enabler);
189 list_for_each_entry_safe(event, tmpevent, &session->events, list)
190 _lttng_event_destroy(event);
191 list_for_each_entry_safe(chan, tmpchan, &session->chan, list) {
192 BUG_ON(chan->channel_type == METADATA_CHANNEL);
193 _lttng_channel_destroy(chan);
194 }
195 list_for_each_entry(metadata_stream, &session->metadata_cache->metadata_stream, list)
196 _lttng_metadata_channel_hangup(metadata_stream);
197 if (session->pid_tracker)
198 lttng_pid_tracker_destroy(session->pid_tracker);
199 kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
200 list_del(&session->list);
201 mutex_unlock(&sessions_mutex);
202 lttng_kvfree(session);
203 }
204
205 int lttng_session_statedump(struct lttng_session *session)
206 {
207 int ret;
208
209 mutex_lock(&sessions_mutex);
210 ret = lttng_statedump_start(session);
211 mutex_unlock(&sessions_mutex);
212 return ret;
213 }
214
215 int lttng_session_enable(struct lttng_session *session)
216 {
217 int ret = 0;
218 struct lttng_channel *chan;
219
220 mutex_lock(&sessions_mutex);
221 if (session->active) {
222 ret = -EBUSY;
223 goto end;
224 }
225
226 /* Set transient enabler state to "enabled" */
227 session->tstate = 1;
228
229 /* We need to sync enablers with session before activation. */
230 lttng_session_sync_enablers(session);
231
232 /*
233 * Snapshot the number of events per channel to know the type of header
234 * we need to use.
235 */
236 list_for_each_entry(chan, &session->chan, list) {
237 if (chan->header_type)
238 continue; /* don't change it if session stop/restart */
239 if (chan->free_event_id < 31)
240 chan->header_type = 1; /* compact */
241 else
242 chan->header_type = 2; /* large */
243 }
244
245 /* Clear each stream's quiescent state. */
246 list_for_each_entry(chan, &session->chan, list) {
247 if (chan->channel_type != METADATA_CHANNEL)
248 lib_ring_buffer_clear_quiescent_channel(chan->chan);
249 }
250
251 WRITE_ONCE(session->active, 1);
252 WRITE_ONCE(session->been_active, 1);
253 ret = _lttng_session_metadata_statedump(session);
254 if (ret) {
255 WRITE_ONCE(session->active, 0);
256 goto end;
257 }
258 ret = lttng_statedump_start(session);
259 if (ret)
260 WRITE_ONCE(session->active, 0);
261 end:
262 mutex_unlock(&sessions_mutex);
263 return ret;
264 }
265
266 int lttng_session_disable(struct lttng_session *session)
267 {
268 int ret = 0;
269 struct lttng_channel *chan;
270
271 mutex_lock(&sessions_mutex);
272 if (!session->active) {
273 ret = -EBUSY;
274 goto end;
275 }
276 WRITE_ONCE(session->active, 0);
277
278 /* Set transient enabler state to "disabled" */
279 session->tstate = 0;
280 lttng_session_sync_enablers(session);
281
282 /* Set each stream's quiescent state. */
283 list_for_each_entry(chan, &session->chan, list) {
284 if (chan->channel_type != METADATA_CHANNEL)
285 lib_ring_buffer_set_quiescent_channel(chan->chan);
286 }
287 end:
288 mutex_unlock(&sessions_mutex);
289 return ret;
290 }
291
292 int lttng_session_metadata_regenerate(struct lttng_session *session)
293 {
294 int ret = 0;
295 struct lttng_channel *chan;
296 struct lttng_event *event;
297 struct lttng_metadata_cache *cache = session->metadata_cache;
298 struct lttng_metadata_stream *stream;
299
300 mutex_lock(&sessions_mutex);
301 if (!session->active) {
302 ret = -EBUSY;
303 goto end;
304 }
305
306 mutex_lock(&cache->lock);
307 memset(cache->data, 0, cache->cache_alloc);
308 cache->metadata_written = 0;
309 cache->version++;
310 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list) {
311 stream->metadata_out = 0;
312 stream->metadata_in = 0;
313 }
314 mutex_unlock(&cache->lock);
315
316 session->metadata_dumped = 0;
317 list_for_each_entry(chan, &session->chan, list) {
318 chan->metadata_dumped = 0;
319 }
320
321 list_for_each_entry(event, &session->events, list) {
322 event->metadata_dumped = 0;
323 }
324
325 ret = _lttng_session_metadata_statedump(session);
326
327 end:
328 mutex_unlock(&sessions_mutex);
329 return ret;
330 }
331
332 int lttng_channel_enable(struct lttng_channel *channel)
333 {
334 int ret = 0;
335
336 mutex_lock(&sessions_mutex);
337 if (channel->channel_type == METADATA_CHANNEL) {
338 ret = -EPERM;
339 goto end;
340 }
341 if (channel->enabled) {
342 ret = -EEXIST;
343 goto end;
344 }
345 /* Set transient enabler state to "enabled" */
346 channel->tstate = 1;
347 lttng_session_sync_enablers(channel->session);
348 /* Set atomically the state to "enabled" */
349 WRITE_ONCE(channel->enabled, 1);
350 end:
351 mutex_unlock(&sessions_mutex);
352 return ret;
353 }
354
355 int lttng_channel_disable(struct lttng_channel *channel)
356 {
357 int ret = 0;
358
359 mutex_lock(&sessions_mutex);
360 if (channel->channel_type == METADATA_CHANNEL) {
361 ret = -EPERM;
362 goto end;
363 }
364 if (!channel->enabled) {
365 ret = -EEXIST;
366 goto end;
367 }
368 /* Set atomically the state to "disabled" */
369 WRITE_ONCE(channel->enabled, 0);
370 /* Set transient enabler state to "enabled" */
371 channel->tstate = 0;
372 lttng_session_sync_enablers(channel->session);
373 end:
374 mutex_unlock(&sessions_mutex);
375 return ret;
376 }
377
378 int lttng_event_enable(struct lttng_event *event)
379 {
380 int ret = 0;
381
382 mutex_lock(&sessions_mutex);
383 if (event->chan->channel_type == METADATA_CHANNEL) {
384 ret = -EPERM;
385 goto end;
386 }
387 if (event->enabled) {
388 ret = -EEXIST;
389 goto end;
390 }
391 switch (event->instrumentation) {
392 case LTTNG_KERNEL_TRACEPOINT:
393 case LTTNG_KERNEL_SYSCALL:
394 ret = -EINVAL;
395 break;
396 case LTTNG_KERNEL_KPROBE:
397 case LTTNG_KERNEL_FUNCTION:
398 case LTTNG_KERNEL_UPROBE:
399 case LTTNG_KERNEL_NOOP:
400 WRITE_ONCE(event->enabled, 1);
401 break;
402 case LTTNG_KERNEL_KRETPROBE:
403 ret = lttng_kretprobes_event_enable_state(event, 1);
404 break;
405 default:
406 WARN_ON_ONCE(1);
407 ret = -EINVAL;
408 }
409 end:
410 mutex_unlock(&sessions_mutex);
411 return ret;
412 }
413
414 int lttng_event_disable(struct lttng_event *event)
415 {
416 int ret = 0;
417
418 mutex_lock(&sessions_mutex);
419 if (event->chan->channel_type == METADATA_CHANNEL) {
420 ret = -EPERM;
421 goto end;
422 }
423 if (!event->enabled) {
424 ret = -EEXIST;
425 goto end;
426 }
427 switch (event->instrumentation) {
428 case LTTNG_KERNEL_TRACEPOINT:
429 case LTTNG_KERNEL_SYSCALL:
430 ret = -EINVAL;
431 break;
432 case LTTNG_KERNEL_KPROBE:
433 case LTTNG_KERNEL_FUNCTION:
434 case LTTNG_KERNEL_UPROBE:
435 case LTTNG_KERNEL_NOOP:
436 WRITE_ONCE(event->enabled, 0);
437 break;
438 case LTTNG_KERNEL_KRETPROBE:
439 ret = lttng_kretprobes_event_enable_state(event, 0);
440 break;
441 default:
442 WARN_ON_ONCE(1);
443 ret = -EINVAL;
444 }
445 end:
446 mutex_unlock(&sessions_mutex);
447 return ret;
448 }
449
450 static struct lttng_transport *lttng_transport_find(const char *name)
451 {
452 struct lttng_transport *transport;
453
454 list_for_each_entry(transport, &lttng_transport_list, node) {
455 if (!strcmp(transport->name, name))
456 return transport;
457 }
458 return NULL;
459 }
460
461 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
462 const char *transport_name,
463 void *buf_addr,
464 size_t subbuf_size, size_t num_subbuf,
465 unsigned int switch_timer_interval,
466 unsigned int read_timer_interval,
467 enum channel_type channel_type)
468 {
469 struct lttng_channel *chan;
470 struct lttng_transport *transport = NULL;
471
472 mutex_lock(&sessions_mutex);
473 if (session->been_active && channel_type != METADATA_CHANNEL)
474 goto active; /* Refuse to add channel to active session */
475 transport = lttng_transport_find(transport_name);
476 if (!transport) {
477 printk(KERN_WARNING "LTTng transport %s not found\n",
478 transport_name);
479 goto notransport;
480 }
481 if (!try_module_get(transport->owner)) {
482 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
483 goto notransport;
484 }
485 chan = kzalloc(sizeof(struct lttng_channel), GFP_KERNEL);
486 if (!chan)
487 goto nomem;
488 chan->session = session;
489 chan->id = session->free_chan_id++;
490 chan->ops = &transport->ops;
491 /*
492 * Note: the channel creation op already writes into the packet
493 * headers. Therefore the "chan" information used as input
494 * should be already accessible.
495 */
496 chan->chan = transport->ops.channel_create(transport_name,
497 chan, buf_addr, subbuf_size, num_subbuf,
498 switch_timer_interval, read_timer_interval);
499 if (!chan->chan)
500 goto create_error;
501 chan->tstate = 1;
502 chan->enabled = 1;
503 chan->transport = transport;
504 chan->channel_type = channel_type;
505 list_add(&chan->list, &session->chan);
506 mutex_unlock(&sessions_mutex);
507 return chan;
508
509 create_error:
510 kfree(chan);
511 nomem:
512 if (transport)
513 module_put(transport->owner);
514 notransport:
515 active:
516 mutex_unlock(&sessions_mutex);
517 return NULL;
518 }
519
520 /*
521 * Only used internally at session destruction for per-cpu channels, and
522 * when metadata channel is released.
523 * Needs to be called with sessions mutex held.
524 */
525 static
526 void _lttng_channel_destroy(struct lttng_channel *chan)
527 {
528 chan->ops->channel_destroy(chan->chan);
529 module_put(chan->transport->owner);
530 list_del(&chan->list);
531 lttng_destroy_context(chan->ctx);
532 kfree(chan);
533 }
534
535 void lttng_metadata_channel_destroy(struct lttng_channel *chan)
536 {
537 BUG_ON(chan->channel_type != METADATA_CHANNEL);
538
539 /* Protect the metadata cache with the sessions_mutex. */
540 mutex_lock(&sessions_mutex);
541 _lttng_channel_destroy(chan);
542 mutex_unlock(&sessions_mutex);
543 }
544 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
545
546 static
547 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
548 {
549 stream->finalized = 1;
550 wake_up_interruptible(&stream->read_wait);
551 }
552
553 /*
554 * Supports event creation while tracing session is active.
555 * Needs to be called with sessions mutex held.
556 */
557 struct lttng_event *_lttng_event_create(struct lttng_channel *chan,
558 struct lttng_kernel_event *event_param,
559 void *filter,
560 const struct lttng_event_desc *event_desc,
561 enum lttng_kernel_instrumentation itype)
562 {
563 struct lttng_session *session = chan->session;
564 struct lttng_event *event;
565 const char *event_name;
566 struct hlist_head *head;
567 size_t name_len;
568 uint32_t hash;
569 int ret;
570
571 if (chan->free_event_id == -1U) {
572 ret = -EMFILE;
573 goto full;
574 }
575
576 switch (itype) {
577 case LTTNG_KERNEL_TRACEPOINT:
578 event_name = event_desc->name;
579 break;
580 case LTTNG_KERNEL_KPROBE:
581 case LTTNG_KERNEL_UPROBE:
582 case LTTNG_KERNEL_KRETPROBE:
583 case LTTNG_KERNEL_FUNCTION:
584 case LTTNG_KERNEL_NOOP:
585 case LTTNG_KERNEL_SYSCALL:
586 event_name = event_param->name;
587 break;
588 default:
589 WARN_ON_ONCE(1);
590 ret = -EINVAL;
591 goto type_error;
592 }
593 name_len = strlen(event_name);
594 hash = jhash(event_name, name_len, 0);
595 head = &session->events_ht.table[hash & (LTTNG_EVENT_HT_SIZE - 1)];
596 lttng_hlist_for_each_entry(event, head, hlist) {
597 WARN_ON_ONCE(!event->desc);
598 if (!strncmp(event->desc->name, event_name,
599 LTTNG_KERNEL_SYM_NAME_LEN - 1)
600 && chan == event->chan) {
601 ret = -EEXIST;
602 goto exist;
603 }
604 }
605
606 event = kmem_cache_zalloc(event_cache, GFP_KERNEL);
607 if (!event) {
608 ret = -ENOMEM;
609 goto cache_error;
610 }
611 event->chan = chan;
612 event->filter = filter;
613 event->id = chan->free_event_id++;
614 event->instrumentation = itype;
615 event->evtype = LTTNG_TYPE_EVENT;
616 INIT_LIST_HEAD(&event->bytecode_runtime_head);
617 INIT_LIST_HEAD(&event->enablers_ref_head);
618
619 switch (itype) {
620 case LTTNG_KERNEL_TRACEPOINT:
621 /* Event will be enabled by enabler sync. */
622 event->enabled = 0;
623 event->registered = 0;
624 event->desc = lttng_event_get(event_name);
625 if (!event->desc) {
626 ret = -ENOENT;
627 goto register_error;
628 }
629 /* Populate lttng_event structure before event registration. */
630 smp_wmb();
631 break;
632 case LTTNG_KERNEL_KPROBE:
633 /*
634 * Needs to be explicitly enabled after creation, since
635 * we may want to apply filters.
636 */
637 event->enabled = 0;
638 event->registered = 1;
639 /*
640 * Populate lttng_event structure before event
641 * registration.
642 */
643 smp_wmb();
644 ret = lttng_kprobes_register(event_name,
645 event_param->u.kprobe.symbol_name,
646 event_param->u.kprobe.offset,
647 event_param->u.kprobe.addr,
648 event);
649 if (ret) {
650 ret = -EINVAL;
651 goto register_error;
652 }
653 ret = try_module_get(event->desc->owner);
654 WARN_ON_ONCE(!ret);
655 break;
656 case LTTNG_KERNEL_KRETPROBE:
657 {
658 struct lttng_event *event_return;
659
660 /* kretprobe defines 2 events */
661 /*
662 * Needs to be explicitly enabled after creation, since
663 * we may want to apply filters.
664 */
665 event->enabled = 0;
666 event->registered = 1;
667 event_return =
668 kmem_cache_zalloc(event_cache, GFP_KERNEL);
669 if (!event_return) {
670 ret = -ENOMEM;
671 goto register_error;
672 }
673 event_return->chan = chan;
674 event_return->filter = filter;
675 event_return->id = chan->free_event_id++;
676 event_return->enabled = 0;
677 event_return->registered = 1;
678 event_return->instrumentation = itype;
679 /*
680 * Populate lttng_event structure before kretprobe registration.
681 */
682 smp_wmb();
683 ret = lttng_kretprobes_register(event_name,
684 event_param->u.kretprobe.symbol_name,
685 event_param->u.kretprobe.offset,
686 event_param->u.kretprobe.addr,
687 event, event_return);
688 if (ret) {
689 kmem_cache_free(event_cache, event_return);
690 ret = -EINVAL;
691 goto register_error;
692 }
693 /* Take 2 refs on the module: one per event. */
694 ret = try_module_get(event->desc->owner);
695 WARN_ON_ONCE(!ret);
696 ret = try_module_get(event->desc->owner);
697 WARN_ON_ONCE(!ret);
698 ret = _lttng_event_metadata_statedump(chan->session, chan,
699 event_return);
700 WARN_ON_ONCE(ret > 0);
701 if (ret) {
702 kmem_cache_free(event_cache, event_return);
703 module_put(event->desc->owner);
704 module_put(event->desc->owner);
705 goto statedump_error;
706 }
707 list_add(&event_return->list, &chan->session->events);
708 break;
709 }
710 case LTTNG_KERNEL_FUNCTION:
711 /*
712 * Needs to be explicitly enabled after creation, since
713 * we may want to apply filters.
714 */
715 event->enabled = 0;
716 event->registered = 1;
717 /*
718 * Populate lttng_event structure before event
719 * registration.
720 */
721 smp_wmb();
722 ret = lttng_ftrace_register(event_name,
723 event_param->u.ftrace.symbol_name,
724 event);
725 if (ret) {
726 goto register_error;
727 }
728 ret = try_module_get(event->desc->owner);
729 WARN_ON_ONCE(!ret);
730 break;
731 case LTTNG_KERNEL_NOOP:
732 case LTTNG_KERNEL_SYSCALL:
733 /*
734 * Needs to be explicitly enabled after creation, since
735 * we may want to apply filters.
736 */
737 event->enabled = 0;
738 event->registered = 0;
739 event->desc = event_desc;
740 if (!event->desc) {
741 ret = -EINVAL;
742 goto register_error;
743 }
744 break;
745 case LTTNG_KERNEL_UPROBE:
746 /*
747 * Needs to be explicitly enabled after creation, since
748 * we may want to apply filters.
749 */
750 event->enabled = 0;
751 event->registered = 1;
752
753 /*
754 * Populate lttng_event structure before event
755 * registration.
756 */
757 smp_wmb();
758
759 ret = lttng_uprobes_register(event_param->name,
760 event_param->u.uprobe.fd,
761 event);
762 if (ret)
763 goto register_error;
764 ret = try_module_get(event->desc->owner);
765 WARN_ON_ONCE(!ret);
766 break;
767 default:
768 WARN_ON_ONCE(1);
769 ret = -EINVAL;
770 goto register_error;
771 }
772 ret = _lttng_event_metadata_statedump(chan->session, chan, event);
773 WARN_ON_ONCE(ret > 0);
774 if (ret) {
775 goto statedump_error;
776 }
777 hlist_add_head(&event->hlist, head);
778 list_add(&event->list, &chan->session->events);
779 return event;
780
781 statedump_error:
782 /* If a statedump error occurs, events will not be readable. */
783 register_error:
784 kmem_cache_free(event_cache, event);
785 cache_error:
786 exist:
787 type_error:
788 full:
789 return ERR_PTR(ret);
790 }
791
792 struct lttng_event *lttng_event_create(struct lttng_channel *chan,
793 struct lttng_kernel_event *event_param,
794 void *filter,
795 const struct lttng_event_desc *event_desc,
796 enum lttng_kernel_instrumentation itype)
797 {
798 struct lttng_event *event;
799
800 mutex_lock(&sessions_mutex);
801 event = _lttng_event_create(chan, event_param, filter, event_desc,
802 itype);
803 mutex_unlock(&sessions_mutex);
804 return event;
805 }
806
807 /* Only used for tracepoints for now. */
808 static
809 void register_event(struct lttng_event *event)
810 {
811 const struct lttng_event_desc *desc;
812 int ret = -EINVAL;
813
814 if (event->registered)
815 return;
816
817 desc = event->desc;
818 switch (event->instrumentation) {
819 case LTTNG_KERNEL_TRACEPOINT:
820 ret = lttng_wrapper_tracepoint_probe_register(desc->kname,
821 desc->probe_callback,
822 event);
823 break;
824 case LTTNG_KERNEL_SYSCALL:
825 ret = lttng_syscall_filter_enable(event->chan,
826 desc->name);
827 break;
828 case LTTNG_KERNEL_KPROBE:
829 case LTTNG_KERNEL_UPROBE:
830 case LTTNG_KERNEL_KRETPROBE:
831 case LTTNG_KERNEL_FUNCTION:
832 case LTTNG_KERNEL_NOOP:
833 ret = 0;
834 break;
835 default:
836 WARN_ON_ONCE(1);
837 }
838 if (!ret)
839 event->registered = 1;
840 }
841
842 /*
843 * Only used internally at session destruction.
844 */
845 int _lttng_event_unregister(struct lttng_event *event)
846 {
847 const struct lttng_event_desc *desc;
848 int ret = -EINVAL;
849
850 if (!event->registered)
851 return 0;
852
853 desc = event->desc;
854 switch (event->instrumentation) {
855 case LTTNG_KERNEL_TRACEPOINT:
856 ret = lttng_wrapper_tracepoint_probe_unregister(event->desc->kname,
857 event->desc->probe_callback,
858 event);
859 break;
860 case LTTNG_KERNEL_KPROBE:
861 lttng_kprobes_unregister(event);
862 ret = 0;
863 break;
864 case LTTNG_KERNEL_KRETPROBE:
865 lttng_kretprobes_unregister(event);
866 ret = 0;
867 break;
868 case LTTNG_KERNEL_FUNCTION:
869 lttng_ftrace_unregister(event);
870 ret = 0;
871 break;
872 case LTTNG_KERNEL_SYSCALL:
873 ret = lttng_syscall_filter_disable(event->chan,
874 desc->name);
875 break;
876 case LTTNG_KERNEL_NOOP:
877 ret = 0;
878 break;
879 case LTTNG_KERNEL_UPROBE:
880 lttng_uprobes_unregister(event);
881 ret = 0;
882 break;
883 default:
884 WARN_ON_ONCE(1);
885 }
886 if (!ret)
887 event->registered = 0;
888 return ret;
889 }
890
891 /*
892 * Only used internally at session destruction.
893 */
894 static
895 void _lttng_event_destroy(struct lttng_event *event)
896 {
897 switch (event->instrumentation) {
898 case LTTNG_KERNEL_TRACEPOINT:
899 lttng_event_put(event->desc);
900 break;
901 case LTTNG_KERNEL_KPROBE:
902 module_put(event->desc->owner);
903 lttng_kprobes_destroy_private(event);
904 break;
905 case LTTNG_KERNEL_KRETPROBE:
906 module_put(event->desc->owner);
907 lttng_kretprobes_destroy_private(event);
908 break;
909 case LTTNG_KERNEL_FUNCTION:
910 module_put(event->desc->owner);
911 lttng_ftrace_destroy_private(event);
912 break;
913 case LTTNG_KERNEL_NOOP:
914 case LTTNG_KERNEL_SYSCALL:
915 break;
916 case LTTNG_KERNEL_UPROBE:
917 module_put(event->desc->owner);
918 lttng_uprobes_destroy_private(event);
919 break;
920 default:
921 WARN_ON_ONCE(1);
922 }
923 list_del(&event->list);
924 lttng_destroy_context(event->ctx);
925 kmem_cache_free(event_cache, event);
926 }
927
928 int lttng_session_track_pid(struct lttng_session *session, int pid)
929 {
930 int ret;
931
932 if (pid < -1)
933 return -EINVAL;
934 mutex_lock(&sessions_mutex);
935 if (pid == -1) {
936 /* track all pids: destroy tracker. */
937 if (session->pid_tracker) {
938 struct lttng_pid_tracker *lpf;
939
940 lpf = session->pid_tracker;
941 rcu_assign_pointer(session->pid_tracker, NULL);
942 synchronize_trace();
943 lttng_pid_tracker_destroy(lpf);
944 }
945 ret = 0;
946 } else {
947 if (!session->pid_tracker) {
948 struct lttng_pid_tracker *lpf;
949
950 lpf = lttng_pid_tracker_create();
951 if (!lpf) {
952 ret = -ENOMEM;
953 goto unlock;
954 }
955 ret = lttng_pid_tracker_add(lpf, pid);
956 rcu_assign_pointer(session->pid_tracker, lpf);
957 } else {
958 ret = lttng_pid_tracker_add(session->pid_tracker, pid);
959 }
960 }
961 unlock:
962 mutex_unlock(&sessions_mutex);
963 return ret;
964 }
965
966 int lttng_session_untrack_pid(struct lttng_session *session, int pid)
967 {
968 int ret;
969
970 if (pid < -1)
971 return -EINVAL;
972 mutex_lock(&sessions_mutex);
973 if (pid == -1) {
974 /* untrack all pids: replace by empty tracker. */
975 struct lttng_pid_tracker *old_lpf = session->pid_tracker;
976 struct lttng_pid_tracker *lpf;
977
978 lpf = lttng_pid_tracker_create();
979 if (!lpf) {
980 ret = -ENOMEM;
981 goto unlock;
982 }
983 rcu_assign_pointer(session->pid_tracker, lpf);
984 synchronize_trace();
985 if (old_lpf)
986 lttng_pid_tracker_destroy(old_lpf);
987 ret = 0;
988 } else {
989 if (!session->pid_tracker) {
990 ret = -ENOENT;
991 goto unlock;
992 }
993 ret = lttng_pid_tracker_del(session->pid_tracker, pid);
994 }
995 unlock:
996 mutex_unlock(&sessions_mutex);
997 return ret;
998 }
999
1000 static
1001 void *pid_list_start(struct seq_file *m, loff_t *pos)
1002 {
1003 struct lttng_session *session = m->private;
1004 struct lttng_pid_tracker *lpf;
1005 struct lttng_pid_hash_node *e;
1006 int iter = 0, i;
1007
1008 mutex_lock(&sessions_mutex);
1009 lpf = session->pid_tracker;
1010 if (lpf) {
1011 for (i = 0; i < LTTNG_PID_TABLE_SIZE; i++) {
1012 struct hlist_head *head = &lpf->pid_hash[i];
1013
1014 lttng_hlist_for_each_entry(e, head, hlist) {
1015 if (iter++ >= *pos)
1016 return e;
1017 }
1018 }
1019 } else {
1020 /* PID tracker disabled. */
1021 if (iter >= *pos && iter == 0) {
1022 return session; /* empty tracker */
1023 }
1024 iter++;
1025 }
1026 /* End of list */
1027 return NULL;
1028 }
1029
1030 /* Called with sessions_mutex held. */
1031 static
1032 void *pid_list_next(struct seq_file *m, void *p, loff_t *ppos)
1033 {
1034 struct lttng_session *session = m->private;
1035 struct lttng_pid_tracker *lpf;
1036 struct lttng_pid_hash_node *e;
1037 int iter = 0, i;
1038
1039 (*ppos)++;
1040 lpf = session->pid_tracker;
1041 if (lpf) {
1042 for (i = 0; i < LTTNG_PID_TABLE_SIZE; i++) {
1043 struct hlist_head *head = &lpf->pid_hash[i];
1044
1045 lttng_hlist_for_each_entry(e, head, hlist) {
1046 if (iter++ >= *ppos)
1047 return e;
1048 }
1049 }
1050 } else {
1051 /* PID tracker disabled. */
1052 if (iter >= *ppos && iter == 0)
1053 return session; /* empty tracker */
1054 iter++;
1055 }
1056
1057 /* End of list */
1058 return NULL;
1059 }
1060
1061 static
1062 void pid_list_stop(struct seq_file *m, void *p)
1063 {
1064 mutex_unlock(&sessions_mutex);
1065 }
1066
1067 static
1068 int pid_list_show(struct seq_file *m, void *p)
1069 {
1070 int pid;
1071
1072 if (p == m->private) {
1073 /* Tracker disabled. */
1074 pid = -1;
1075 } else {
1076 const struct lttng_pid_hash_node *e = p;
1077
1078 pid = lttng_pid_tracker_get_node_pid(e);
1079 }
1080 seq_printf(m, "process { pid = %d; };\n", pid);
1081 return 0;
1082 }
1083
1084 static
1085 const struct seq_operations lttng_tracker_pids_list_seq_ops = {
1086 .start = pid_list_start,
1087 .next = pid_list_next,
1088 .stop = pid_list_stop,
1089 .show = pid_list_show,
1090 };
1091
1092 static
1093 int lttng_tracker_pids_list_open(struct inode *inode, struct file *file)
1094 {
1095 return seq_open(file, &lttng_tracker_pids_list_seq_ops);
1096 }
1097
1098 static
1099 int lttng_tracker_pids_list_release(struct inode *inode, struct file *file)
1100 {
1101 struct seq_file *m = file->private_data;
1102 struct lttng_session *session = m->private;
1103 int ret;
1104
1105 WARN_ON_ONCE(!session);
1106 ret = seq_release(inode, file);
1107 if (!ret && session)
1108 fput(session->file);
1109 return ret;
1110 }
1111
1112 const struct file_operations lttng_tracker_pids_list_fops = {
1113 .owner = THIS_MODULE,
1114 .open = lttng_tracker_pids_list_open,
1115 .read = seq_read,
1116 .llseek = seq_lseek,
1117 .release = lttng_tracker_pids_list_release,
1118 };
1119
1120 int lttng_session_list_tracker_pids(struct lttng_session *session)
1121 {
1122 struct file *tracker_pids_list_file;
1123 struct seq_file *m;
1124 int file_fd, ret;
1125
1126 file_fd = lttng_get_unused_fd();
1127 if (file_fd < 0) {
1128 ret = file_fd;
1129 goto fd_error;
1130 }
1131
1132 tracker_pids_list_file = anon_inode_getfile("[lttng_tracker_pids_list]",
1133 &lttng_tracker_pids_list_fops,
1134 NULL, O_RDWR);
1135 if (IS_ERR(tracker_pids_list_file)) {
1136 ret = PTR_ERR(tracker_pids_list_file);
1137 goto file_error;
1138 }
1139 if (atomic_long_add_unless(&session->file->f_count,
1140 1, INT_MAX) == INT_MAX) {
1141 goto refcount_error;
1142 }
1143 ret = lttng_tracker_pids_list_fops.open(NULL, tracker_pids_list_file);
1144 if (ret < 0)
1145 goto open_error;
1146 m = tracker_pids_list_file->private_data;
1147 m->private = session;
1148 fd_install(file_fd, tracker_pids_list_file);
1149
1150 return file_fd;
1151
1152 open_error:
1153 atomic_long_dec(&session->file->f_count);
1154 refcount_error:
1155 fput(tracker_pids_list_file);
1156 file_error:
1157 put_unused_fd(file_fd);
1158 fd_error:
1159 return ret;
1160 }
1161
1162 /*
1163 * Enabler management.
1164 */
1165 static
1166 int lttng_match_enabler_star_glob(const char *desc_name,
1167 const char *pattern)
1168 {
1169 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1170 desc_name, LTTNG_SIZE_MAX))
1171 return 0;
1172 return 1;
1173 }
1174
1175 static
1176 int lttng_match_enabler_name(const char *desc_name,
1177 const char *name)
1178 {
1179 if (strcmp(desc_name, name))
1180 return 0;
1181 return 1;
1182 }
1183
1184 static
1185 int lttng_desc_match_enabler(const struct lttng_event_desc *desc,
1186 struct lttng_enabler *enabler)
1187 {
1188 const char *desc_name, *enabler_name;
1189
1190 enabler_name = enabler->event_param.name;
1191 switch (enabler->event_param.instrumentation) {
1192 case LTTNG_KERNEL_TRACEPOINT:
1193 desc_name = desc->name;
1194 break;
1195 case LTTNG_KERNEL_SYSCALL:
1196 desc_name = desc->name;
1197 if (!strncmp(desc_name, "compat_", strlen("compat_")))
1198 desc_name += strlen("compat_");
1199 if (!strncmp(desc_name, "syscall_exit_",
1200 strlen("syscall_exit_"))) {
1201 desc_name += strlen("syscall_exit_");
1202 } else if (!strncmp(desc_name, "syscall_entry_",
1203 strlen("syscall_entry_"))) {
1204 desc_name += strlen("syscall_entry_");
1205 } else {
1206 WARN_ON_ONCE(1);
1207 return -EINVAL;
1208 }
1209 break;
1210 default:
1211 WARN_ON_ONCE(1);
1212 return -EINVAL;
1213 }
1214 switch (enabler->type) {
1215 case LTTNG_ENABLER_STAR_GLOB:
1216 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1217 case LTTNG_ENABLER_NAME:
1218 return lttng_match_enabler_name(desc_name, enabler_name);
1219 default:
1220 return -EINVAL;
1221 }
1222 }
1223
1224 static
1225 int lttng_event_match_enabler(struct lttng_event *event,
1226 struct lttng_enabler *enabler)
1227 {
1228 if (enabler->event_param.instrumentation != event->instrumentation)
1229 return 0;
1230 if (lttng_desc_match_enabler(event->desc, enabler)
1231 && event->chan == enabler->chan)
1232 return 1;
1233 else
1234 return 0;
1235 }
1236
1237 static
1238 struct lttng_enabler_ref *lttng_event_enabler_ref(struct lttng_event *event,
1239 struct lttng_enabler *enabler)
1240 {
1241 struct lttng_enabler_ref *enabler_ref;
1242
1243 list_for_each_entry(enabler_ref,
1244 &event->enablers_ref_head, node) {
1245 if (enabler_ref->ref == enabler)
1246 return enabler_ref;
1247 }
1248 return NULL;
1249 }
1250
1251 static
1252 void lttng_create_tracepoint_if_missing(struct lttng_enabler *enabler)
1253 {
1254 struct lttng_session *session = enabler->chan->session;
1255 struct lttng_probe_desc *probe_desc;
1256 const struct lttng_event_desc *desc;
1257 int i;
1258 struct list_head *probe_list;
1259
1260 probe_list = lttng_get_probe_list_head();
1261 /*
1262 * For each probe event, if we find that a probe event matches
1263 * our enabler, create an associated lttng_event if not
1264 * already present.
1265 */
1266 list_for_each_entry(probe_desc, probe_list, head) {
1267 for (i = 0; i < probe_desc->nr_events; i++) {
1268 int found = 0;
1269 struct hlist_head *head;
1270 const char *event_name;
1271 size_t name_len;
1272 uint32_t hash;
1273 struct lttng_event *event;
1274
1275 desc = probe_desc->event_desc[i];
1276 if (!lttng_desc_match_enabler(desc, enabler))
1277 continue;
1278 event_name = desc->name;
1279 name_len = strlen(event_name);
1280
1281 /*
1282 * Check if already created.
1283 */
1284 hash = jhash(event_name, name_len, 0);
1285 head = &session->events_ht.table[hash & (LTTNG_EVENT_HT_SIZE - 1)];
1286 lttng_hlist_for_each_entry(event, head, hlist) {
1287 if (event->desc == desc
1288 && event->chan == enabler->chan)
1289 found = 1;
1290 }
1291 if (found)
1292 continue;
1293
1294 /*
1295 * We need to create an event for this
1296 * event probe.
1297 */
1298 event = _lttng_event_create(enabler->chan,
1299 NULL, NULL, desc,
1300 LTTNG_KERNEL_TRACEPOINT);
1301 if (!event) {
1302 printk(KERN_INFO "Unable to create event %s\n",
1303 probe_desc->event_desc[i]->name);
1304 }
1305 }
1306 }
1307 }
1308
1309 static
1310 void lttng_create_syscall_if_missing(struct lttng_enabler *enabler)
1311 {
1312 int ret;
1313
1314 ret = lttng_syscalls_register(enabler->chan, NULL);
1315 WARN_ON_ONCE(ret);
1316 }
1317
1318 /*
1319 * Create struct lttng_event if it is missing and present in the list of
1320 * tracepoint probes.
1321 * Should be called with sessions mutex held.
1322 */
1323 static
1324 void lttng_create_event_if_missing(struct lttng_enabler *enabler)
1325 {
1326 switch (enabler->event_param.instrumentation) {
1327 case LTTNG_KERNEL_TRACEPOINT:
1328 lttng_create_tracepoint_if_missing(enabler);
1329 break;
1330 case LTTNG_KERNEL_SYSCALL:
1331 lttng_create_syscall_if_missing(enabler);
1332 break;
1333 default:
1334 WARN_ON_ONCE(1);
1335 break;
1336 }
1337 }
1338
1339 /*
1340 * Create events associated with an enabler (if not already present),
1341 * and add backward reference from the event to the enabler.
1342 * Should be called with sessions mutex held.
1343 */
1344 static
1345 int lttng_enabler_ref_events(struct lttng_enabler *enabler)
1346 {
1347 struct lttng_session *session = enabler->chan->session;
1348 struct lttng_event *event;
1349
1350 /* First ensure that probe events are created for this enabler. */
1351 lttng_create_event_if_missing(enabler);
1352
1353 /* For each event matching enabler in session event list. */
1354 list_for_each_entry(event, &session->events, list) {
1355 struct lttng_enabler_ref *enabler_ref;
1356
1357 if (!lttng_event_match_enabler(event, enabler))
1358 continue;
1359 enabler_ref = lttng_event_enabler_ref(event, enabler);
1360 if (!enabler_ref) {
1361 /*
1362 * If no backward ref, create it.
1363 * Add backward ref from event to enabler.
1364 */
1365 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
1366 if (!enabler_ref)
1367 return -ENOMEM;
1368 enabler_ref->ref = enabler;
1369 list_add(&enabler_ref->node,
1370 &event->enablers_ref_head);
1371 }
1372
1373 /*
1374 * Link filter bytecodes if not linked yet.
1375 */
1376 lttng_enabler_event_link_bytecode(event, enabler);
1377
1378 /* TODO: merge event context. */
1379 }
1380 return 0;
1381 }
1382
1383 /*
1384 * Called at module load: connect the probe on all enablers matching
1385 * this event.
1386 * Called with sessions lock held.
1387 */
1388 int lttng_fix_pending_events(void)
1389 {
1390 struct lttng_session *session;
1391
1392 list_for_each_entry(session, &sessions, list)
1393 lttng_session_lazy_sync_enablers(session);
1394 return 0;
1395 }
1396
1397 struct lttng_enabler *lttng_enabler_create(enum lttng_enabler_type type,
1398 struct lttng_kernel_event *event_param,
1399 struct lttng_channel *chan)
1400 {
1401 struct lttng_enabler *enabler;
1402
1403 enabler = kzalloc(sizeof(*enabler), GFP_KERNEL);
1404 if (!enabler)
1405 return NULL;
1406 enabler->type = type;
1407 INIT_LIST_HEAD(&enabler->filter_bytecode_head);
1408 memcpy(&enabler->event_param, event_param,
1409 sizeof(enabler->event_param));
1410 enabler->chan = chan;
1411 /* ctx left NULL */
1412 enabler->enabled = 0;
1413 enabler->evtype = LTTNG_TYPE_ENABLER;
1414 mutex_lock(&sessions_mutex);
1415 list_add(&enabler->node, &enabler->chan->session->enablers_head);
1416 lttng_session_lazy_sync_enablers(enabler->chan->session);
1417 mutex_unlock(&sessions_mutex);
1418 return enabler;
1419 }
1420
1421 int lttng_enabler_enable(struct lttng_enabler *enabler)
1422 {
1423 mutex_lock(&sessions_mutex);
1424 enabler->enabled = 1;
1425 lttng_session_lazy_sync_enablers(enabler->chan->session);
1426 mutex_unlock(&sessions_mutex);
1427 return 0;
1428 }
1429
1430 int lttng_enabler_disable(struct lttng_enabler *enabler)
1431 {
1432 mutex_lock(&sessions_mutex);
1433 enabler->enabled = 0;
1434 lttng_session_lazy_sync_enablers(enabler->chan->session);
1435 mutex_unlock(&sessions_mutex);
1436 return 0;
1437 }
1438
1439 int lttng_enabler_attach_bytecode(struct lttng_enabler *enabler,
1440 struct lttng_kernel_filter_bytecode __user *bytecode)
1441 {
1442 struct lttng_filter_bytecode_node *bytecode_node;
1443 uint32_t bytecode_len;
1444 int ret;
1445
1446 ret = get_user(bytecode_len, &bytecode->len);
1447 if (ret)
1448 return ret;
1449 bytecode_node = kzalloc(sizeof(*bytecode_node) + bytecode_len,
1450 GFP_KERNEL);
1451 if (!bytecode_node)
1452 return -ENOMEM;
1453 ret = copy_from_user(&bytecode_node->bc, bytecode,
1454 sizeof(*bytecode) + bytecode_len);
1455 if (ret)
1456 goto error_free;
1457 bytecode_node->enabler = enabler;
1458 /* Enforce length based on allocated size */
1459 bytecode_node->bc.len = bytecode_len;
1460 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
1461 lttng_session_lazy_sync_enablers(enabler->chan->session);
1462 return 0;
1463
1464 error_free:
1465 kfree(bytecode_node);
1466 return ret;
1467 }
1468
1469 int lttng_event_add_callsite(struct lttng_event *event,
1470 struct lttng_kernel_event_callsite __user *callsite)
1471 {
1472
1473 switch (event->instrumentation) {
1474 case LTTNG_KERNEL_UPROBE:
1475 return lttng_uprobes_add_callsite(event, callsite);
1476 default:
1477 return -EINVAL;
1478 }
1479 }
1480
1481 int lttng_enabler_attach_context(struct lttng_enabler *enabler,
1482 struct lttng_kernel_context *context_param)
1483 {
1484 return -ENOSYS;
1485 }
1486
1487 static
1488 void lttng_enabler_destroy(struct lttng_enabler *enabler)
1489 {
1490 struct lttng_filter_bytecode_node *filter_node, *tmp_filter_node;
1491
1492 /* Destroy filter bytecode */
1493 list_for_each_entry_safe(filter_node, tmp_filter_node,
1494 &enabler->filter_bytecode_head, node) {
1495 kfree(filter_node);
1496 }
1497
1498 /* Destroy contexts */
1499 lttng_destroy_context(enabler->ctx);
1500
1501 list_del(&enabler->node);
1502 kfree(enabler);
1503 }
1504
1505 /*
1506 * lttng_session_sync_enablers should be called just before starting a
1507 * session.
1508 * Should be called with sessions mutex held.
1509 */
1510 static
1511 void lttng_session_sync_enablers(struct lttng_session *session)
1512 {
1513 struct lttng_enabler *enabler;
1514 struct lttng_event *event;
1515
1516 list_for_each_entry(enabler, &session->enablers_head, node)
1517 lttng_enabler_ref_events(enabler);
1518 /*
1519 * For each event, if at least one of its enablers is enabled,
1520 * and its channel and session transient states are enabled, we
1521 * enable the event, else we disable it.
1522 */
1523 list_for_each_entry(event, &session->events, list) {
1524 struct lttng_enabler_ref *enabler_ref;
1525 struct lttng_bytecode_runtime *runtime;
1526 int enabled = 0, has_enablers_without_bytecode = 0;
1527
1528 switch (event->instrumentation) {
1529 case LTTNG_KERNEL_TRACEPOINT:
1530 case LTTNG_KERNEL_SYSCALL:
1531 /* Enable events */
1532 list_for_each_entry(enabler_ref,
1533 &event->enablers_ref_head, node) {
1534 if (enabler_ref->ref->enabled) {
1535 enabled = 1;
1536 break;
1537 }
1538 }
1539 break;
1540 default:
1541 /* Not handled with lazy sync. */
1542 continue;
1543 }
1544 /*
1545 * Enabled state is based on union of enablers, with
1546 * intesection of session and channel transient enable
1547 * states.
1548 */
1549 enabled = enabled && session->tstate && event->chan->tstate;
1550
1551 WRITE_ONCE(event->enabled, enabled);
1552 /*
1553 * Sync tracepoint registration with event enabled
1554 * state.
1555 */
1556 if (enabled) {
1557 register_event(event);
1558 } else {
1559 _lttng_event_unregister(event);
1560 }
1561
1562 /* Check if has enablers without bytecode enabled */
1563 list_for_each_entry(enabler_ref,
1564 &event->enablers_ref_head, node) {
1565 if (enabler_ref->ref->enabled
1566 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
1567 has_enablers_without_bytecode = 1;
1568 break;
1569 }
1570 }
1571 event->has_enablers_without_bytecode =
1572 has_enablers_without_bytecode;
1573
1574 /* Enable filters */
1575 list_for_each_entry(runtime,
1576 &event->bytecode_runtime_head, node)
1577 lttng_filter_sync_state(runtime);
1578 }
1579 }
1580
1581 /*
1582 * Apply enablers to session events, adding events to session if need
1583 * be. It is required after each modification applied to an active
1584 * session, and right before session "start".
1585 * "lazy" sync means we only sync if required.
1586 * Should be called with sessions mutex held.
1587 */
1588 static
1589 void lttng_session_lazy_sync_enablers(struct lttng_session *session)
1590 {
1591 /* We can skip if session is not active */
1592 if (!session->active)
1593 return;
1594 lttng_session_sync_enablers(session);
1595 }
1596
1597 /*
1598 * Serialize at most one packet worth of metadata into a metadata
1599 * channel.
1600 * We grab the metadata cache mutex to get exclusive access to our metadata
1601 * buffer and to the metadata cache. Exclusive access to the metadata buffer
1602 * allows us to do racy operations such as looking for remaining space left in
1603 * packet and write, since mutual exclusion protects us from concurrent writes.
1604 * Mutual exclusion on the metadata cache allow us to read the cache content
1605 * without racing against reallocation of the cache by updates.
1606 * Returns the number of bytes written in the channel, 0 if no data
1607 * was written and a negative value on error.
1608 */
1609 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
1610 struct channel *chan)
1611 {
1612 struct lib_ring_buffer_ctx ctx;
1613 int ret = 0;
1614 size_t len, reserve_len;
1615
1616 /*
1617 * Ensure we support mutiple get_next / put sequences followed by
1618 * put_next. The metadata cache lock protects reading the metadata
1619 * cache. It can indeed be read concurrently by "get_next_subbuf" and
1620 * "flush" operations on the buffer invoked by different processes.
1621 * Moreover, since the metadata cache memory can be reallocated, we
1622 * need to have exclusive access against updates even though we only
1623 * read it.
1624 */
1625 mutex_lock(&stream->metadata_cache->lock);
1626 WARN_ON(stream->metadata_in < stream->metadata_out);
1627 if (stream->metadata_in != stream->metadata_out)
1628 goto end;
1629
1630 /* Metadata regenerated, change the version. */
1631 if (stream->metadata_cache->version != stream->version)
1632 stream->version = stream->metadata_cache->version;
1633
1634 len = stream->metadata_cache->metadata_written -
1635 stream->metadata_in;
1636 if (!len)
1637 goto end;
1638 reserve_len = min_t(size_t,
1639 stream->transport->ops.packet_avail_size(chan),
1640 len);
1641 lib_ring_buffer_ctx_init(&ctx, chan, NULL, reserve_len,
1642 sizeof(char), -1);
1643 /*
1644 * If reservation failed, return an error to the caller.
1645 */
1646 ret = stream->transport->ops.event_reserve(&ctx, 0);
1647 if (ret != 0) {
1648 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
1649 goto end;
1650 }
1651 stream->transport->ops.event_write(&ctx,
1652 stream->metadata_cache->data + stream->metadata_in,
1653 reserve_len);
1654 stream->transport->ops.event_commit(&ctx);
1655 stream->metadata_in += reserve_len;
1656 ret = reserve_len;
1657
1658 end:
1659 mutex_unlock(&stream->metadata_cache->lock);
1660 return ret;
1661 }
1662
1663 /*
1664 * Write the metadata to the metadata cache.
1665 * Must be called with sessions_mutex held.
1666 * The metadata cache lock protects us from concurrent read access from
1667 * thread outputting metadata content to ring buffer.
1668 */
1669 int lttng_metadata_printf(struct lttng_session *session,
1670 const char *fmt, ...)
1671 {
1672 char *str;
1673 size_t len;
1674 va_list ap;
1675 struct lttng_metadata_stream *stream;
1676
1677 WARN_ON_ONCE(!READ_ONCE(session->active));
1678
1679 va_start(ap, fmt);
1680 str = kvasprintf(GFP_KERNEL, fmt, ap);
1681 va_end(ap);
1682 if (!str)
1683 return -ENOMEM;
1684
1685 len = strlen(str);
1686 mutex_lock(&session->metadata_cache->lock);
1687 if (session->metadata_cache->metadata_written + len >
1688 session->metadata_cache->cache_alloc) {
1689 char *tmp_cache_realloc;
1690 unsigned int tmp_cache_alloc_size;
1691
1692 tmp_cache_alloc_size = max_t(unsigned int,
1693 session->metadata_cache->cache_alloc + len,
1694 session->metadata_cache->cache_alloc << 1);
1695 tmp_cache_realloc = lttng_vzalloc(tmp_cache_alloc_size);
1696 if (!tmp_cache_realloc)
1697 goto err;
1698 if (session->metadata_cache->data) {
1699 memcpy(tmp_cache_realloc,
1700 session->metadata_cache->data,
1701 session->metadata_cache->cache_alloc);
1702 vfree(session->metadata_cache->data);
1703 }
1704
1705 session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
1706 session->metadata_cache->data = tmp_cache_realloc;
1707 }
1708 memcpy(session->metadata_cache->data +
1709 session->metadata_cache->metadata_written,
1710 str, len);
1711 session->metadata_cache->metadata_written += len;
1712 mutex_unlock(&session->metadata_cache->lock);
1713 kfree(str);
1714
1715 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
1716 wake_up_interruptible(&stream->read_wait);
1717
1718 return 0;
1719
1720 err:
1721 mutex_unlock(&session->metadata_cache->lock);
1722 kfree(str);
1723 return -ENOMEM;
1724 }
1725
1726 static
1727 int print_tabs(struct lttng_session *session, size_t nesting)
1728 {
1729 size_t i;
1730
1731 for (i = 0; i < nesting; i++) {
1732 int ret;
1733
1734 ret = lttng_metadata_printf(session, " ");
1735 if (ret) {
1736 return ret;
1737 }
1738 }
1739 return 0;
1740 }
1741
1742 /*
1743 * Must be called with sessions_mutex held.
1744 */
1745 static
1746 int _lttng_struct_type_statedump(struct lttng_session *session,
1747 const struct lttng_type *type,
1748 size_t nesting)
1749 {
1750 int ret;
1751 uint32_t i, nr_fields;
1752
1753 ret = print_tabs(session, nesting);
1754 if (ret)
1755 return ret;
1756 ret = lttng_metadata_printf(session,
1757 "struct {\n");
1758 if (ret)
1759 return ret;
1760 nr_fields = type->u._struct.nr_fields;
1761 for (i = 0; i < nr_fields; i++) {
1762 const struct lttng_event_field *iter_field;
1763
1764 iter_field = &type->u._struct.fields[i];
1765 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
1766 if (ret)
1767 return ret;
1768 }
1769 ret = print_tabs(session, nesting);
1770 if (ret)
1771 return ret;
1772 ret = lttng_metadata_printf(session,
1773 "}");
1774 return ret;
1775 }
1776
1777 /*
1778 * Must be called with sessions_mutex held.
1779 */
1780 static
1781 int _lttng_struct_statedump(struct lttng_session *session,
1782 const struct lttng_event_field *field,
1783 size_t nesting)
1784 {
1785 int ret;
1786
1787 ret = _lttng_struct_type_statedump(session,
1788 &field->type, nesting);
1789 if (ret)
1790 return ret;
1791 ret = lttng_metadata_printf(session,
1792 "_%s;\n",
1793 field->name);
1794 return ret;
1795 }
1796
1797 /*
1798 * Must be called with sessions_mutex held.
1799 */
1800 static
1801 int _lttng_variant_type_statedump(struct lttng_session *session,
1802 const struct lttng_type *type,
1803 size_t nesting)
1804 {
1805 int ret;
1806 uint32_t i, nr_choices;
1807
1808 ret = print_tabs(session, nesting);
1809 if (ret)
1810 return ret;
1811 ret = lttng_metadata_printf(session,
1812 "variant <_%s> {\n",
1813 type->u.variant.tag_name);
1814 if (ret)
1815 return ret;
1816 nr_choices = type->u.variant.nr_choices;
1817 for (i = 0; i < nr_choices; i++) {
1818 const struct lttng_event_field *iter_field;
1819
1820 iter_field = &type->u.variant.choices[i];
1821 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
1822 if (ret)
1823 return ret;
1824 }
1825 ret = print_tabs(session, nesting);
1826 if (ret)
1827 return ret;
1828 ret = lttng_metadata_printf(session,
1829 "}");
1830 return ret;
1831 }
1832
1833 /*
1834 * Must be called with sessions_mutex held.
1835 */
1836 static
1837 int _lttng_variant_statedump(struct lttng_session *session,
1838 const struct lttng_event_field *field,
1839 size_t nesting)
1840 {
1841 int ret;
1842
1843 ret = _lttng_variant_type_statedump(session,
1844 &field->type, nesting);
1845 if (ret)
1846 return ret;
1847 ret = lttng_metadata_printf(session,
1848 "_%s;\n",
1849 field->name);
1850 return ret;
1851 }
1852
1853 /*
1854 * Must be called with sessions_mutex held.
1855 */
1856 static
1857 int _lttng_array_compound_statedump(struct lttng_session *session,
1858 const struct lttng_event_field *field,
1859 size_t nesting)
1860 {
1861 int ret;
1862 const struct lttng_type *elem_type;
1863
1864 /* Only array of structures and variants are currently supported. */
1865 elem_type = field->type.u.array_compound.elem_type;
1866 switch (elem_type->atype) {
1867 case atype_struct:
1868 ret = _lttng_struct_type_statedump(session, elem_type, nesting);
1869 if (ret)
1870 return ret;
1871 break;
1872 case atype_variant:
1873 ret = _lttng_variant_type_statedump(session, elem_type, nesting);
1874 if (ret)
1875 return ret;
1876 break;
1877 default:
1878 return -EINVAL;
1879 }
1880 ret = lttng_metadata_printf(session,
1881 " _%s[%u];\n",
1882 field->name,
1883 field->type.u.array_compound.length);
1884 return ret;
1885 }
1886
1887 /*
1888 * Must be called with sessions_mutex held.
1889 */
1890 static
1891 int _lttng_sequence_compound_statedump(struct lttng_session *session,
1892 const struct lttng_event_field *field,
1893 size_t nesting)
1894 {
1895 int ret;
1896 const char *length_name;
1897 const struct lttng_type *elem_type;
1898
1899 length_name = field->type.u.sequence_compound.length_name;
1900
1901 /* Only array of structures and variants are currently supported. */
1902 elem_type = field->type.u.sequence_compound.elem_type;
1903 switch (elem_type->atype) {
1904 case atype_struct:
1905 ret = _lttng_struct_type_statedump(session, elem_type, nesting);
1906 if (ret)
1907 return ret;
1908 break;
1909 case atype_variant:
1910 ret = _lttng_variant_type_statedump(session, elem_type, nesting);
1911 if (ret)
1912 return ret;
1913 break;
1914 default:
1915 return -EINVAL;
1916 }
1917 ret = lttng_metadata_printf(session,
1918 " _%s[ _%s ];\n",
1919 field->name,
1920 length_name);
1921 return ret;
1922 }
1923
1924 /*
1925 * Must be called with sessions_mutex held.
1926 */
1927 static
1928 int _lttng_enum_statedump(struct lttng_session *session,
1929 const struct lttng_event_field *field,
1930 size_t nesting)
1931 {
1932 const struct lttng_enum_desc *enum_desc;
1933 const struct lttng_integer_type *container_type;
1934 int ret;
1935 unsigned int i, nr_entries;
1936
1937 enum_desc = field->type.u.basic.enumeration.desc;
1938 container_type = &field->type.u.basic.enumeration.container_type;
1939 nr_entries = enum_desc->nr_entries;
1940
1941 ret = print_tabs(session, nesting);
1942 if (ret)
1943 goto end;
1944 ret = lttng_metadata_printf(session,
1945 "enum : integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } {\n",
1946 container_type->size,
1947 container_type->alignment,
1948 container_type->signedness,
1949 (container_type->encoding == lttng_encode_none)
1950 ? "none"
1951 : (container_type->encoding == lttng_encode_UTF8)
1952 ? "UTF8"
1953 : "ASCII",
1954 container_type->base,
1955 #if __BYTE_ORDER == __BIG_ENDIAN
1956 container_type->reverse_byte_order ? " byte_order = le;" : ""
1957 #else
1958 container_type->reverse_byte_order ? " byte_order = be;" : ""
1959 #endif
1960 );
1961 if (ret)
1962 goto end;
1963 /* Dump all entries */
1964 for (i = 0; i < nr_entries; i++) {
1965 const struct lttng_enum_entry *entry = &enum_desc->entries[i];
1966 int j, len;
1967
1968 ret = print_tabs(session, nesting + 1);
1969 if (ret)
1970 goto end;
1971 ret = lttng_metadata_printf(session,
1972 "\"");
1973 if (ret)
1974 goto end;
1975 len = strlen(entry->string);
1976 /* Escape the character '"' */
1977 for (j = 0; j < len; j++) {
1978 char c = entry->string[j];
1979
1980 switch (c) {
1981 case '"':
1982 ret = lttng_metadata_printf(session,
1983 "\\\"");
1984 break;
1985 case '\\':
1986 ret = lttng_metadata_printf(session,
1987 "\\\\");
1988 break;
1989 default:
1990 ret = lttng_metadata_printf(session,
1991 "%c", c);
1992 break;
1993 }
1994 if (ret)
1995 goto end;
1996 }
1997 ret = lttng_metadata_printf(session, "\"");
1998 if (ret)
1999 goto end;
2000
2001 if (entry->options.is_auto) {
2002 ret = lttng_metadata_printf(session, ",\n");
2003 if (ret)
2004 goto end;
2005 } else {
2006 ret = lttng_metadata_printf(session,
2007 " = ");
2008 if (ret)
2009 goto end;
2010 if (entry->start.signedness)
2011 ret = lttng_metadata_printf(session,
2012 "%lld", (long long) entry->start.value);
2013 else
2014 ret = lttng_metadata_printf(session,
2015 "%llu", entry->start.value);
2016 if (ret)
2017 goto end;
2018 if (entry->start.signedness == entry->end.signedness &&
2019 entry->start.value
2020 == entry->end.value) {
2021 ret = lttng_metadata_printf(session,
2022 ",\n");
2023 } else {
2024 if (entry->end.signedness) {
2025 ret = lttng_metadata_printf(session,
2026 " ... %lld,\n",
2027 (long long) entry->end.value);
2028 } else {
2029 ret = lttng_metadata_printf(session,
2030 " ... %llu,\n",
2031 entry->end.value);
2032 }
2033 }
2034 if (ret)
2035 goto end;
2036 }
2037 }
2038 ret = print_tabs(session, nesting);
2039 if (ret)
2040 goto end;
2041 ret = lttng_metadata_printf(session, "} _%s;\n",
2042 field->name);
2043 end:
2044 return ret;
2045 }
2046
2047 /*
2048 * Must be called with sessions_mutex held.
2049 */
2050 static
2051 int _lttng_field_statedump(struct lttng_session *session,
2052 const struct lttng_event_field *field,
2053 size_t nesting)
2054 {
2055 int ret = 0;
2056
2057 switch (field->type.atype) {
2058 case atype_integer:
2059 ret = print_tabs(session, nesting);
2060 if (ret)
2061 return ret;
2062 ret = lttng_metadata_printf(session,
2063 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
2064 field->type.u.basic.integer.size,
2065 field->type.u.basic.integer.alignment,
2066 field->type.u.basic.integer.signedness,
2067 (field->type.u.basic.integer.encoding == lttng_encode_none)
2068 ? "none"
2069 : (field->type.u.basic.integer.encoding == lttng_encode_UTF8)
2070 ? "UTF8"
2071 : "ASCII",
2072 field->type.u.basic.integer.base,
2073 #if __BYTE_ORDER == __BIG_ENDIAN
2074 field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2075 #else
2076 field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2077 #endif
2078 field->name);
2079 break;
2080 case atype_enum:
2081 ret = _lttng_enum_statedump(session, field, nesting);
2082 break;
2083 case atype_array:
2084 case atype_array_bitfield:
2085 {
2086 const struct lttng_basic_type *elem_type;
2087
2088 elem_type = &field->type.u.array.elem_type;
2089 if (field->type.u.array.elem_alignment) {
2090 ret = print_tabs(session, nesting);
2091 if (ret)
2092 return ret;
2093 ret = lttng_metadata_printf(session,
2094 "struct { } align(%u) _%s_padding;\n",
2095 field->type.u.array.elem_alignment * CHAR_BIT,
2096 field->name);
2097 if (ret)
2098 return ret;
2099 }
2100 ret = print_tabs(session, nesting);
2101 if (ret)
2102 return ret;
2103 ret = lttng_metadata_printf(session,
2104 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
2105 elem_type->u.basic.integer.size,
2106 elem_type->u.basic.integer.alignment,
2107 elem_type->u.basic.integer.signedness,
2108 (elem_type->u.basic.integer.encoding == lttng_encode_none)
2109 ? "none"
2110 : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
2111 ? "UTF8"
2112 : "ASCII",
2113 elem_type->u.basic.integer.base,
2114 #if __BYTE_ORDER == __BIG_ENDIAN
2115 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2116 #else
2117 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2118 #endif
2119 field->name, field->type.u.array.length);
2120 break;
2121 }
2122 case atype_sequence:
2123 case atype_sequence_bitfield:
2124 {
2125 const struct lttng_basic_type *elem_type;
2126 const struct lttng_basic_type *length_type;
2127
2128 elem_type = &field->type.u.sequence.elem_type;
2129 length_type = &field->type.u.sequence.length_type;
2130 ret = print_tabs(session, nesting);
2131 if (ret)
2132 return ret;
2133 ret = lttng_metadata_printf(session,
2134 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
2135 length_type->u.basic.integer.size,
2136 (unsigned int) length_type->u.basic.integer.alignment,
2137 length_type->u.basic.integer.signedness,
2138 (length_type->u.basic.integer.encoding == lttng_encode_none)
2139 ? "none"
2140 : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8)
2141 ? "UTF8"
2142 : "ASCII"),
2143 length_type->u.basic.integer.base,
2144 #if __BYTE_ORDER == __BIG_ENDIAN
2145 length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2146 #else
2147 length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2148 #endif
2149 field->name);
2150 if (ret)
2151 return ret;
2152
2153 if (field->type.u.sequence.elem_alignment) {
2154 ret = print_tabs(session, nesting);
2155 if (ret)
2156 return ret;
2157 ret = lttng_metadata_printf(session,
2158 "struct { } align(%u) _%s_padding;\n",
2159 field->type.u.sequence.elem_alignment * CHAR_BIT,
2160 field->name);
2161 if (ret)
2162 return ret;
2163 }
2164 ret = print_tabs(session, nesting);
2165 if (ret)
2166 return ret;
2167 ret = lttng_metadata_printf(session,
2168 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
2169 elem_type->u.basic.integer.size,
2170 (unsigned int) elem_type->u.basic.integer.alignment,
2171 elem_type->u.basic.integer.signedness,
2172 (elem_type->u.basic.integer.encoding == lttng_encode_none)
2173 ? "none"
2174 : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
2175 ? "UTF8"
2176 : "ASCII"),
2177 elem_type->u.basic.integer.base,
2178 #if __BYTE_ORDER == __BIG_ENDIAN
2179 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2180 #else
2181 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2182 #endif
2183 field->name,
2184 field->name);
2185 break;
2186 }
2187
2188 case atype_string:
2189 /* Default encoding is UTF8 */
2190 ret = print_tabs(session, nesting);
2191 if (ret)
2192 return ret;
2193 ret = lttng_metadata_printf(session,
2194 "string%s _%s;\n",
2195 field->type.u.basic.string.encoding == lttng_encode_ASCII ?
2196 " { encoding = ASCII; }" : "",
2197 field->name);
2198 break;
2199 case atype_struct:
2200 ret = _lttng_struct_statedump(session, field, nesting);
2201 break;
2202 case atype_array_compound:
2203 ret = _lttng_array_compound_statedump(session, field, nesting);
2204 break;
2205 case atype_sequence_compound:
2206 ret = _lttng_sequence_compound_statedump(session, field, nesting);
2207 break;
2208 case atype_variant:
2209 ret = _lttng_variant_statedump(session, field, nesting);
2210 break;
2211
2212 default:
2213 WARN_ON_ONCE(1);
2214 return -EINVAL;
2215 }
2216 return ret;
2217 }
2218
2219 static
2220 int _lttng_context_metadata_statedump(struct lttng_session *session,
2221 struct lttng_ctx *ctx)
2222 {
2223 int ret = 0;
2224 int i;
2225
2226 if (!ctx)
2227 return 0;
2228 for (i = 0; i < ctx->nr_fields; i++) {
2229 const struct lttng_ctx_field *field = &ctx->fields[i];
2230
2231 ret = _lttng_field_statedump(session, &field->event_field, 2);
2232 if (ret)
2233 return ret;
2234 }
2235 return ret;
2236 }
2237
2238 static
2239 int _lttng_fields_metadata_statedump(struct lttng_session *session,
2240 struct lttng_event *event)
2241 {
2242 const struct lttng_event_desc *desc = event->desc;
2243 int ret = 0;
2244 int i;
2245
2246 for (i = 0; i < desc->nr_fields; i++) {
2247 const struct lttng_event_field *field = &desc->fields[i];
2248
2249 ret = _lttng_field_statedump(session, field, 2);
2250 if (ret)
2251 return ret;
2252 }
2253 return ret;
2254 }
2255
2256 /*
2257 * Must be called with sessions_mutex held.
2258 */
2259 static
2260 int _lttng_event_metadata_statedump(struct lttng_session *session,
2261 struct lttng_channel *chan,
2262 struct lttng_event *event)
2263 {
2264 int ret = 0;
2265
2266 if (event->metadata_dumped || !READ_ONCE(session->active))
2267 return 0;
2268 if (chan->channel_type == METADATA_CHANNEL)
2269 return 0;
2270
2271 ret = lttng_metadata_printf(session,
2272 "event {\n"
2273 " name = \"%s\";\n"
2274 " id = %u;\n"
2275 " stream_id = %u;\n",
2276 event->desc->name,
2277 event->id,
2278 event->chan->id);
2279 if (ret)
2280 goto end;
2281
2282 if (event->ctx) {
2283 ret = lttng_metadata_printf(session,
2284 " context := struct {\n");
2285 if (ret)
2286 goto end;
2287 }
2288 ret = _lttng_context_metadata_statedump(session, event->ctx);
2289 if (ret)
2290 goto end;
2291 if (event->ctx) {
2292 ret = lttng_metadata_printf(session,
2293 " };\n");
2294 if (ret)
2295 goto end;
2296 }
2297
2298 ret = lttng_metadata_printf(session,
2299 " fields := struct {\n"
2300 );
2301 if (ret)
2302 goto end;
2303
2304 ret = _lttng_fields_metadata_statedump(session, event);
2305 if (ret)
2306 goto end;
2307
2308 /*
2309 * LTTng space reservation can only reserve multiples of the
2310 * byte size.
2311 */
2312 ret = lttng_metadata_printf(session,
2313 " };\n"
2314 "};\n\n");
2315 if (ret)
2316 goto end;
2317
2318 event->metadata_dumped = 1;
2319 end:
2320 return ret;
2321
2322 }
2323
2324 /*
2325 * Must be called with sessions_mutex held.
2326 */
2327 static
2328 int _lttng_channel_metadata_statedump(struct lttng_session *session,
2329 struct lttng_channel *chan)
2330 {
2331 int ret = 0;
2332
2333 if (chan->metadata_dumped || !READ_ONCE(session->active))
2334 return 0;
2335
2336 if (chan->channel_type == METADATA_CHANNEL)
2337 return 0;
2338
2339 WARN_ON_ONCE(!chan->header_type);
2340 ret = lttng_metadata_printf(session,
2341 "stream {\n"
2342 " id = %u;\n"
2343 " event.header := %s;\n"
2344 " packet.context := struct packet_context;\n",
2345 chan->id,
2346 chan->header_type == 1 ? "struct event_header_compact" :
2347 "struct event_header_large");
2348 if (ret)
2349 goto end;
2350
2351 if (chan->ctx) {
2352 ret = lttng_metadata_printf(session,
2353 " event.context := struct {\n");
2354 if (ret)
2355 goto end;
2356 }
2357 ret = _lttng_context_metadata_statedump(session, chan->ctx);
2358 if (ret)
2359 goto end;
2360 if (chan->ctx) {
2361 ret = lttng_metadata_printf(session,
2362 " };\n");
2363 if (ret)
2364 goto end;
2365 }
2366
2367 ret = lttng_metadata_printf(session,
2368 "};\n\n");
2369
2370 chan->metadata_dumped = 1;
2371 end:
2372 return ret;
2373 }
2374
2375 /*
2376 * Must be called with sessions_mutex held.
2377 */
2378 static
2379 int _lttng_stream_packet_context_declare(struct lttng_session *session)
2380 {
2381 return lttng_metadata_printf(session,
2382 "struct packet_context {\n"
2383 " uint64_clock_monotonic_t timestamp_begin;\n"
2384 " uint64_clock_monotonic_t timestamp_end;\n"
2385 " uint64_t content_size;\n"
2386 " uint64_t packet_size;\n"
2387 " uint64_t packet_seq_num;\n"
2388 " unsigned long events_discarded;\n"
2389 " uint32_t cpu_id;\n"
2390 "};\n\n"
2391 );
2392 }
2393
2394 /*
2395 * Compact header:
2396 * id: range: 0 - 30.
2397 * id 31 is reserved to indicate an extended header.
2398 *
2399 * Large header:
2400 * id: range: 0 - 65534.
2401 * id 65535 is reserved to indicate an extended header.
2402 *
2403 * Must be called with sessions_mutex held.
2404 */
2405 static
2406 int _lttng_event_header_declare(struct lttng_session *session)
2407 {
2408 return lttng_metadata_printf(session,
2409 "struct event_header_compact {\n"
2410 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
2411 " variant <id> {\n"
2412 " struct {\n"
2413 " uint27_clock_monotonic_t timestamp;\n"
2414 " } compact;\n"
2415 " struct {\n"
2416 " uint32_t id;\n"
2417 " uint64_clock_monotonic_t timestamp;\n"
2418 " } extended;\n"
2419 " } v;\n"
2420 "} align(%u);\n"
2421 "\n"
2422 "struct event_header_large {\n"
2423 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
2424 " variant <id> {\n"
2425 " struct {\n"
2426 " uint32_clock_monotonic_t timestamp;\n"
2427 " } compact;\n"
2428 " struct {\n"
2429 " uint32_t id;\n"
2430 " uint64_clock_monotonic_t timestamp;\n"
2431 " } extended;\n"
2432 " } v;\n"
2433 "} align(%u);\n\n",
2434 lttng_alignof(uint32_t) * CHAR_BIT,
2435 lttng_alignof(uint16_t) * CHAR_BIT
2436 );
2437 }
2438
2439 /*
2440 * Approximation of NTP time of day to clock monotonic correlation,
2441 * taken at start of trace.
2442 * Yes, this is only an approximation. Yes, we can (and will) do better
2443 * in future versions.
2444 * This function may return a negative offset. It may happen if the
2445 * system sets the REALTIME clock to 0 after boot.
2446 */
2447 static
2448 int64_t measure_clock_offset(void)
2449 {
2450 uint64_t monotonic_avg, monotonic[2], realtime;
2451 uint64_t tcf = trace_clock_freq();
2452 int64_t offset;
2453 struct timespec rts = { 0, 0 };
2454 unsigned long flags;
2455
2456 /* Disable interrupts to increase correlation precision. */
2457 local_irq_save(flags);
2458 monotonic[0] = trace_clock_read64();
2459 getnstimeofday(&rts);
2460 monotonic[1] = trace_clock_read64();
2461 local_irq_restore(flags);
2462
2463 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
2464 realtime = (uint64_t) rts.tv_sec * tcf;
2465 if (tcf == NSEC_PER_SEC) {
2466 realtime += rts.tv_nsec;
2467 } else {
2468 uint64_t n = rts.tv_nsec * tcf;
2469
2470 do_div(n, NSEC_PER_SEC);
2471 realtime += n;
2472 }
2473 offset = (int64_t) realtime - monotonic_avg;
2474 return offset;
2475 }
2476
2477 /*
2478 * Output metadata into this session's metadata buffers.
2479 * Must be called with sessions_mutex held.
2480 */
2481 static
2482 int _lttng_session_metadata_statedump(struct lttng_session *session)
2483 {
2484 unsigned char *uuid_c = session->uuid.b;
2485 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
2486 struct lttng_channel *chan;
2487 struct lttng_event *event;
2488 int ret = 0;
2489
2490 if (!READ_ONCE(session->active))
2491 return 0;
2492 if (session->metadata_dumped)
2493 goto skip_session;
2494
2495 snprintf(uuid_s, sizeof(uuid_s),
2496 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
2497 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
2498 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
2499 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
2500 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
2501
2502 ret = lttng_metadata_printf(session,
2503 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
2504 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
2505 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
2506 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
2507 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
2508 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
2509 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
2510 "\n"
2511 "trace {\n"
2512 " major = %u;\n"
2513 " minor = %u;\n"
2514 " uuid = \"%s\";\n"
2515 " byte_order = %s;\n"
2516 " packet.header := struct {\n"
2517 " uint32_t magic;\n"
2518 " uint8_t uuid[16];\n"
2519 " uint32_t stream_id;\n"
2520 " uint64_t stream_instance_id;\n"
2521 " };\n"
2522 "};\n\n",
2523 lttng_alignof(uint8_t) * CHAR_BIT,
2524 lttng_alignof(uint16_t) * CHAR_BIT,
2525 lttng_alignof(uint32_t) * CHAR_BIT,
2526 lttng_alignof(uint64_t) * CHAR_BIT,
2527 sizeof(unsigned long) * CHAR_BIT,
2528 lttng_alignof(unsigned long) * CHAR_BIT,
2529 CTF_SPEC_MAJOR,
2530 CTF_SPEC_MINOR,
2531 uuid_s,
2532 #if __BYTE_ORDER == __BIG_ENDIAN
2533 "be"
2534 #else
2535 "le"
2536 #endif
2537 );
2538 if (ret)
2539 goto end;
2540
2541 ret = lttng_metadata_printf(session,
2542 "env {\n"
2543 " hostname = \"%s\";\n"
2544 " domain = \"kernel\";\n"
2545 " sysname = \"%s\";\n"
2546 " kernel_release = \"%s\";\n"
2547 " kernel_version = \"%s\";\n"
2548 " tracer_name = \"lttng-modules\";\n"
2549 " tracer_major = %d;\n"
2550 " tracer_minor = %d;\n"
2551 " tracer_patchlevel = %d;\n"
2552 "};\n\n",
2553 current->nsproxy->uts_ns->name.nodename,
2554 utsname()->sysname,
2555 utsname()->release,
2556 utsname()->version,
2557 LTTNG_MODULES_MAJOR_VERSION,
2558 LTTNG_MODULES_MINOR_VERSION,
2559 LTTNG_MODULES_PATCHLEVEL_VERSION
2560 );
2561 if (ret)
2562 goto end;
2563
2564 ret = lttng_metadata_printf(session,
2565 "clock {\n"
2566 " name = \"%s\";\n",
2567 trace_clock_name()
2568 );
2569 if (ret)
2570 goto end;
2571
2572 if (!trace_clock_uuid(clock_uuid_s)) {
2573 ret = lttng_metadata_printf(session,
2574 " uuid = \"%s\";\n",
2575 clock_uuid_s
2576 );
2577 if (ret)
2578 goto end;
2579 }
2580
2581 ret = lttng_metadata_printf(session,
2582 " description = \"%s\";\n"
2583 " freq = %llu; /* Frequency, in Hz */\n"
2584 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
2585 " offset = %lld;\n"
2586 "};\n\n",
2587 trace_clock_description(),
2588 (unsigned long long) trace_clock_freq(),
2589 (long long) measure_clock_offset()
2590 );
2591 if (ret)
2592 goto end;
2593
2594 ret = lttng_metadata_printf(session,
2595 "typealias integer {\n"
2596 " size = 27; align = 1; signed = false;\n"
2597 " map = clock.%s.value;\n"
2598 "} := uint27_clock_monotonic_t;\n"
2599 "\n"
2600 "typealias integer {\n"
2601 " size = 32; align = %u; signed = false;\n"
2602 " map = clock.%s.value;\n"
2603 "} := uint32_clock_monotonic_t;\n"
2604 "\n"
2605 "typealias integer {\n"
2606 " size = 64; align = %u; signed = false;\n"
2607 " map = clock.%s.value;\n"
2608 "} := uint64_clock_monotonic_t;\n\n",
2609 trace_clock_name(),
2610 lttng_alignof(uint32_t) * CHAR_BIT,
2611 trace_clock_name(),
2612 lttng_alignof(uint64_t) * CHAR_BIT,
2613 trace_clock_name()
2614 );
2615 if (ret)
2616 goto end;
2617
2618 ret = _lttng_stream_packet_context_declare(session);
2619 if (ret)
2620 goto end;
2621
2622 ret = _lttng_event_header_declare(session);
2623 if (ret)
2624 goto end;
2625
2626 skip_session:
2627 list_for_each_entry(chan, &session->chan, list) {
2628 ret = _lttng_channel_metadata_statedump(session, chan);
2629 if (ret)
2630 goto end;
2631 }
2632
2633 list_for_each_entry(event, &session->events, list) {
2634 ret = _lttng_event_metadata_statedump(session, event->chan, event);
2635 if (ret)
2636 goto end;
2637 }
2638 session->metadata_dumped = 1;
2639 end:
2640 return ret;
2641 }
2642
2643 /**
2644 * lttng_transport_register - LTT transport registration
2645 * @transport: transport structure
2646 *
2647 * Registers a transport which can be used as output to extract the data out of
2648 * LTTng. The module calling this registration function must ensure that no
2649 * trap-inducing code will be executed by the transport functions. E.g.
2650 * vmalloc_sync_all() must be called between a vmalloc and the moment the memory
2651 * is made visible to the transport function. This registration acts as a
2652 * vmalloc_sync_all. Therefore, only if the module allocates virtual memory
2653 * after its registration must it synchronize the TLBs.
2654 */
2655 void lttng_transport_register(struct lttng_transport *transport)
2656 {
2657 /*
2658 * Make sure no page fault can be triggered by the module about to be
2659 * registered. We deal with this here so we don't have to call
2660 * vmalloc_sync_all() in each module's init.
2661 */
2662 wrapper_vmalloc_sync_all();
2663
2664 mutex_lock(&sessions_mutex);
2665 list_add_tail(&transport->node, &lttng_transport_list);
2666 mutex_unlock(&sessions_mutex);
2667 }
2668 EXPORT_SYMBOL_GPL(lttng_transport_register);
2669
2670 /**
2671 * lttng_transport_unregister - LTT transport unregistration
2672 * @transport: transport structure
2673 */
2674 void lttng_transport_unregister(struct lttng_transport *transport)
2675 {
2676 mutex_lock(&sessions_mutex);
2677 list_del(&transport->node);
2678 mutex_unlock(&sessions_mutex);
2679 }
2680 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
2681
2682 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
2683
2684 enum cpuhp_state lttng_hp_prepare;
2685 enum cpuhp_state lttng_hp_online;
2686
2687 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
2688 {
2689 struct lttng_cpuhp_node *lttng_node;
2690
2691 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2692 switch (lttng_node->component) {
2693 case LTTNG_RING_BUFFER_FRONTEND:
2694 return 0;
2695 case LTTNG_RING_BUFFER_BACKEND:
2696 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
2697 case LTTNG_RING_BUFFER_ITER:
2698 return 0;
2699 case LTTNG_CONTEXT_PERF_COUNTERS:
2700 return 0;
2701 default:
2702 return -EINVAL;
2703 }
2704 }
2705
2706 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
2707 {
2708 struct lttng_cpuhp_node *lttng_node;
2709
2710 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2711 switch (lttng_node->component) {
2712 case LTTNG_RING_BUFFER_FRONTEND:
2713 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
2714 case LTTNG_RING_BUFFER_BACKEND:
2715 return 0;
2716 case LTTNG_RING_BUFFER_ITER:
2717 return 0;
2718 case LTTNG_CONTEXT_PERF_COUNTERS:
2719 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
2720 default:
2721 return -EINVAL;
2722 }
2723 }
2724
2725 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
2726 {
2727 struct lttng_cpuhp_node *lttng_node;
2728
2729 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2730 switch (lttng_node->component) {
2731 case LTTNG_RING_BUFFER_FRONTEND:
2732 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
2733 case LTTNG_RING_BUFFER_BACKEND:
2734 return 0;
2735 case LTTNG_RING_BUFFER_ITER:
2736 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
2737 case LTTNG_CONTEXT_PERF_COUNTERS:
2738 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
2739 default:
2740 return -EINVAL;
2741 }
2742 }
2743
2744 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
2745 {
2746 struct lttng_cpuhp_node *lttng_node;
2747
2748 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2749 switch (lttng_node->component) {
2750 case LTTNG_RING_BUFFER_FRONTEND:
2751 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
2752 case LTTNG_RING_BUFFER_BACKEND:
2753 return 0;
2754 case LTTNG_RING_BUFFER_ITER:
2755 return 0;
2756 case LTTNG_CONTEXT_PERF_COUNTERS:
2757 return 0;
2758 default:
2759 return -EINVAL;
2760 }
2761 }
2762
2763 static int __init lttng_init_cpu_hotplug(void)
2764 {
2765 int ret;
2766
2767 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
2768 lttng_hotplug_prepare,
2769 lttng_hotplug_dead);
2770 if (ret < 0) {
2771 return ret;
2772 }
2773 lttng_hp_prepare = ret;
2774 lttng_rb_set_hp_prepare(ret);
2775
2776 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
2777 lttng_hotplug_online,
2778 lttng_hotplug_offline);
2779 if (ret < 0) {
2780 cpuhp_remove_multi_state(lttng_hp_prepare);
2781 lttng_hp_prepare = 0;
2782 return ret;
2783 }
2784 lttng_hp_online = ret;
2785 lttng_rb_set_hp_online(ret);
2786
2787 return 0;
2788 }
2789
2790 static void __exit lttng_exit_cpu_hotplug(void)
2791 {
2792 lttng_rb_set_hp_online(0);
2793 cpuhp_remove_multi_state(lttng_hp_online);
2794 lttng_rb_set_hp_prepare(0);
2795 cpuhp_remove_multi_state(lttng_hp_prepare);
2796 }
2797
2798 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
2799 static int lttng_init_cpu_hotplug(void)
2800 {
2801 return 0;
2802 }
2803 static void lttng_exit_cpu_hotplug(void)
2804 {
2805 }
2806 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
2807
2808
2809 static int __init lttng_events_init(void)
2810 {
2811 int ret;
2812
2813 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
2814 if (ret)
2815 return ret;
2816 ret = wrapper_get_pfnblock_flags_mask_init();
2817 if (ret)
2818 return ret;
2819 ret = wrapper_get_pageblock_flags_mask_init();
2820 if (ret)
2821 return ret;
2822 ret = lttng_probes_init();
2823 if (ret)
2824 return ret;
2825 ret = lttng_context_init();
2826 if (ret)
2827 return ret;
2828 ret = lttng_tracepoint_init();
2829 if (ret)
2830 goto error_tp;
2831 event_cache = KMEM_CACHE(lttng_event, 0);
2832 if (!event_cache) {
2833 ret = -ENOMEM;
2834 goto error_kmem;
2835 }
2836 ret = lttng_abi_init();
2837 if (ret)
2838 goto error_abi;
2839 ret = lttng_logger_init();
2840 if (ret)
2841 goto error_logger;
2842 ret = lttng_init_cpu_hotplug();
2843 if (ret)
2844 goto error_hotplug;
2845 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
2846 __stringify(LTTNG_MODULES_MAJOR_VERSION),
2847 __stringify(LTTNG_MODULES_MINOR_VERSION),
2848 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
2849 LTTNG_MODULES_EXTRAVERSION,
2850 LTTNG_VERSION_NAME,
2851 #ifdef LTTNG_EXTRA_VERSION_GIT
2852 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
2853 #else
2854 "",
2855 #endif
2856 #ifdef LTTNG_EXTRA_VERSION_NAME
2857 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
2858 #else
2859 "");
2860 #endif
2861 return 0;
2862
2863 error_hotplug:
2864 lttng_logger_exit();
2865 error_logger:
2866 lttng_abi_exit();
2867 error_abi:
2868 kmem_cache_destroy(event_cache);
2869 error_kmem:
2870 lttng_tracepoint_exit();
2871 error_tp:
2872 lttng_context_exit();
2873 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
2874 __stringify(LTTNG_MODULES_MAJOR_VERSION),
2875 __stringify(LTTNG_MODULES_MINOR_VERSION),
2876 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
2877 LTTNG_MODULES_EXTRAVERSION,
2878 LTTNG_VERSION_NAME,
2879 #ifdef LTTNG_EXTRA_VERSION_GIT
2880 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
2881 #else
2882 "",
2883 #endif
2884 #ifdef LTTNG_EXTRA_VERSION_NAME
2885 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
2886 #else
2887 "");
2888 #endif
2889 return ret;
2890 }
2891
2892 module_init(lttng_events_init);
2893
2894 static void __exit lttng_events_exit(void)
2895 {
2896 struct lttng_session *session, *tmpsession;
2897
2898 lttng_exit_cpu_hotplug();
2899 lttng_logger_exit();
2900 lttng_abi_exit();
2901 list_for_each_entry_safe(session, tmpsession, &sessions, list)
2902 lttng_session_destroy(session);
2903 kmem_cache_destroy(event_cache);
2904 lttng_tracepoint_exit();
2905 lttng_context_exit();
2906 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
2907 __stringify(LTTNG_MODULES_MAJOR_VERSION),
2908 __stringify(LTTNG_MODULES_MINOR_VERSION),
2909 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
2910 LTTNG_MODULES_EXTRAVERSION,
2911 LTTNG_VERSION_NAME,
2912 #ifdef LTTNG_EXTRA_VERSION_GIT
2913 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
2914 #else
2915 "",
2916 #endif
2917 #ifdef LTTNG_EXTRA_VERSION_NAME
2918 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
2919 #else
2920 "");
2921 #endif
2922 }
2923
2924 module_exit(lttng_events_exit);
2925
2926 #include "extra_version/patches.i"
2927 #ifdef LTTNG_EXTRA_VERSION_GIT
2928 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
2929 #endif
2930 #ifdef LTTNG_EXTRA_VERSION_NAME
2931 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
2932 #endif
2933 MODULE_LICENSE("GPL and additional rights");
2934 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
2935 MODULE_DESCRIPTION("LTTng tracer");
2936 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
2937 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
2938 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
2939 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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