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