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[lttng-modules.git] / src / lttng-events.c
1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
2 *
3 * lttng-events.c
4 *
5 * Holds LTTng per-session event registry.
6 *
7 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 */
9
10 /*
11 * This page_alloc.h wrapper needs to be included before gfpflags.h because it
12 * overrides a function with a define.
13 */
14 #include "wrapper/page_alloc.h"
15
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/jiffies.h>
21 #include <linux/utsname.h>
22 #include <linux/err.h>
23 #include <linux/seq_file.h>
24 #include <linux/file.h>
25 #include <linux/anon_inodes.h>
26 #include <wrapper/file.h>
27 #include <linux/uaccess.h>
28 #include <linux/vmalloc.h>
29 #include <linux/dmi.h>
30
31 #include <wrapper/uuid.h>
32 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_mappings() */
33 #include <wrapper/random.h>
34 #include <wrapper/tracepoint.h>
35 #include <wrapper/list.h>
36 #include <wrapper/types.h>
37 #include <lttng/kernel-version.h>
38 #include <lttng/events.h>
39 #include <lttng/events-internal.h>
40 #include <lttng/lttng-bytecode.h>
41 #include <lttng/tracer.h>
42 #include <lttng/event-notifier-notification.h>
43 #include <lttng/abi-old.h>
44 #include <lttng/endian.h>
45 #include <lttng/string-utils.h>
46 #include <lttng/utils.h>
47 #include <ringbuffer/backend.h>
48 #include <ringbuffer/frontend.h>
49 #include <wrapper/time.h>
50
51 #define METADATA_CACHE_DEFAULT_SIZE 4096
52
53 static LIST_HEAD(sessions);
54 static LIST_HEAD(event_notifier_groups);
55 static LIST_HEAD(lttng_transport_list);
56 static LIST_HEAD(lttng_counter_transport_list);
57 /*
58 * Protect the sessions and metadata caches.
59 */
60 static DEFINE_MUTEX(sessions_mutex);
61 static struct kmem_cache *event_recorder_cache;
62 static struct kmem_cache *event_recorder_private_cache;
63 static struct kmem_cache *event_notifier_cache;
64 static struct kmem_cache *event_notifier_private_cache;
65
66 static void lttng_session_lazy_sync_event_enablers(struct lttng_session *session);
67 static void lttng_session_sync_event_enablers(struct lttng_session *session);
68 static void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler);
69 static void lttng_event_notifier_enabler_destroy(struct lttng_event_notifier_enabler *event_notifier_enabler);
70 static void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group);
71
72 static void _lttng_event_destroy(struct lttng_kernel_event_common *event);
73 static void _lttng_channel_destroy(struct lttng_channel *chan);
74 static int _lttng_event_unregister(struct lttng_kernel_event_recorder *event);
75 static int _lttng_event_notifier_unregister(struct lttng_kernel_event_notifier *event_notifier);
76 static
77 int _lttng_event_metadata_statedump(struct lttng_session *session,
78 struct lttng_channel *chan,
79 struct lttng_kernel_event_recorder *event);
80 static
81 int _lttng_session_metadata_statedump(struct lttng_session *session);
82 static
83 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
84 static
85 int _lttng_type_statedump(struct lttng_session *session,
86 const struct lttng_kernel_type_common *type,
87 enum lttng_kernel_string_encoding parent_encoding,
88 size_t nesting);
89 static
90 int _lttng_field_statedump(struct lttng_session *session,
91 const struct lttng_kernel_event_field *field,
92 size_t nesting);
93
94 void synchronize_trace(void)
95 {
96 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,1,0))
97 synchronize_rcu();
98 #else
99 synchronize_sched();
100 #endif
101
102 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0))
103 #ifdef CONFIG_PREEMPT_RT_FULL
104 synchronize_rcu();
105 #endif
106 #else /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
107 #ifdef CONFIG_PREEMPT_RT
108 synchronize_rcu();
109 #endif
110 #endif /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
111 }
112
113 void lttng_lock_sessions(void)
114 {
115 mutex_lock(&sessions_mutex);
116 }
117
118 void lttng_unlock_sessions(void)
119 {
120 mutex_unlock(&sessions_mutex);
121 }
122
123 static struct lttng_transport *lttng_transport_find(const char *name)
124 {
125 struct lttng_transport *transport;
126
127 list_for_each_entry(transport, &lttng_transport_list, node) {
128 if (!strcmp(transport->name, name))
129 return transport;
130 }
131 return NULL;
132 }
133
134 /*
135 * Called with sessions lock held.
136 */
137 int lttng_session_active(void)
138 {
139 struct lttng_session *iter;
140
141 list_for_each_entry(iter, &sessions, list) {
142 if (iter->active)
143 return 1;
144 }
145 return 0;
146 }
147
148 struct lttng_session *lttng_session_create(void)
149 {
150 struct lttng_session *session;
151 struct lttng_metadata_cache *metadata_cache;
152 int i;
153
154 mutex_lock(&sessions_mutex);
155 session = lttng_kvzalloc(sizeof(struct lttng_session), GFP_KERNEL);
156 if (!session)
157 goto err;
158 INIT_LIST_HEAD(&session->chan);
159 INIT_LIST_HEAD(&session->events);
160 lttng_guid_gen(&session->uuid);
161
162 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
163 GFP_KERNEL);
164 if (!metadata_cache)
165 goto err_free_session;
166 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
167 if (!metadata_cache->data)
168 goto err_free_cache;
169 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
170 kref_init(&metadata_cache->refcount);
171 mutex_init(&metadata_cache->lock);
172 session->metadata_cache = metadata_cache;
173 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
174 memcpy(&metadata_cache->uuid, &session->uuid,
175 sizeof(metadata_cache->uuid));
176 INIT_LIST_HEAD(&session->enablers_head);
177 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
178 INIT_HLIST_HEAD(&session->events_ht.table[i]);
179 list_add(&session->list, &sessions);
180 session->pid_tracker.session = session;
181 session->pid_tracker.tracker_type = TRACKER_PID;
182 session->vpid_tracker.session = session;
183 session->vpid_tracker.tracker_type = TRACKER_VPID;
184 session->uid_tracker.session = session;
185 session->uid_tracker.tracker_type = TRACKER_UID;
186 session->vuid_tracker.session = session;
187 session->vuid_tracker.tracker_type = TRACKER_VUID;
188 session->gid_tracker.session = session;
189 session->gid_tracker.tracker_type = TRACKER_GID;
190 session->vgid_tracker.session = session;
191 session->vgid_tracker.tracker_type = TRACKER_VGID;
192 mutex_unlock(&sessions_mutex);
193 return session;
194
195 err_free_cache:
196 kfree(metadata_cache);
197 err_free_session:
198 lttng_kvfree(session);
199 err:
200 mutex_unlock(&sessions_mutex);
201 return NULL;
202 }
203
204 static
205 struct lttng_counter_transport *lttng_counter_transport_find(const char *name)
206 {
207 struct lttng_counter_transport *transport;
208
209 list_for_each_entry(transport, &lttng_counter_transport_list, node) {
210 if (!strcmp(transport->name, name))
211 return transport;
212 }
213 return NULL;
214 }
215
216 struct lttng_counter *lttng_kernel_counter_create(
217 const char *counter_transport_name,
218 size_t number_dimensions, const size_t *dimensions_sizes)
219 {
220 struct lttng_counter *counter = NULL;
221 struct lttng_counter_transport *counter_transport = NULL;
222
223 counter_transport = lttng_counter_transport_find(counter_transport_name);
224 if (!counter_transport) {
225 printk(KERN_WARNING "LTTng: counter transport %s not found.\n",
226 counter_transport_name);
227 goto notransport;
228 }
229 if (!try_module_get(counter_transport->owner)) {
230 printk(KERN_WARNING "LTTng: Can't lock counter transport module.\n");
231 goto notransport;
232 }
233
234 counter = lttng_kvzalloc(sizeof(struct lttng_counter), GFP_KERNEL);
235 if (!counter)
236 goto nomem;
237
238 /* Create event notifier error counter. */
239 counter->ops = &counter_transport->ops;
240 counter->transport = counter_transport;
241
242 counter->counter = counter->ops->counter_create(
243 number_dimensions, dimensions_sizes, 0);
244 if (!counter->counter) {
245 goto create_error;
246 }
247
248 return counter;
249
250 create_error:
251 lttng_kvfree(counter);
252 nomem:
253 if (counter_transport)
254 module_put(counter_transport->owner);
255 notransport:
256 return NULL;
257 }
258
259 struct lttng_event_notifier_group *lttng_event_notifier_group_create(void)
260 {
261 struct lttng_transport *transport = NULL;
262 struct lttng_event_notifier_group *event_notifier_group;
263 const char *transport_name = "relay-event-notifier";
264 size_t subbuf_size = 4096; //TODO
265 size_t num_subbuf = 16; //TODO
266 unsigned int switch_timer_interval = 0;
267 unsigned int read_timer_interval = 0;
268 int i;
269
270 mutex_lock(&sessions_mutex);
271
272 transport = lttng_transport_find(transport_name);
273 if (!transport) {
274 printk(KERN_WARNING "LTTng: transport %s not found\n",
275 transport_name);
276 goto notransport;
277 }
278 if (!try_module_get(transport->owner)) {
279 printk(KERN_WARNING "LTTng: Can't lock transport %s module.\n",
280 transport_name);
281 goto notransport;
282 }
283
284 event_notifier_group = lttng_kvzalloc(sizeof(struct lttng_event_notifier_group),
285 GFP_KERNEL);
286 if (!event_notifier_group)
287 goto nomem;
288
289 /*
290 * Initialize the ring buffer used to store event notifier
291 * notifications.
292 */
293 event_notifier_group->ops = &transport->ops;
294 event_notifier_group->chan = transport->ops.channel_create(
295 transport_name, event_notifier_group, NULL,
296 subbuf_size, num_subbuf, switch_timer_interval,
297 read_timer_interval);
298 if (!event_notifier_group->chan)
299 goto create_error;
300
301 event_notifier_group->transport = transport;
302
303 INIT_LIST_HEAD(&event_notifier_group->enablers_head);
304 INIT_LIST_HEAD(&event_notifier_group->event_notifiers_head);
305 for (i = 0; i < LTTNG_EVENT_NOTIFIER_HT_SIZE; i++)
306 INIT_HLIST_HEAD(&event_notifier_group->event_notifiers_ht.table[i]);
307
308 list_add(&event_notifier_group->node, &event_notifier_groups);
309
310 mutex_unlock(&sessions_mutex);
311
312 return event_notifier_group;
313
314 create_error:
315 lttng_kvfree(event_notifier_group);
316 nomem:
317 if (transport)
318 module_put(transport->owner);
319 notransport:
320 mutex_unlock(&sessions_mutex);
321 return NULL;
322 }
323
324 void metadata_cache_destroy(struct kref *kref)
325 {
326 struct lttng_metadata_cache *cache =
327 container_of(kref, struct lttng_metadata_cache, refcount);
328 vfree(cache->data);
329 kfree(cache);
330 }
331
332 void lttng_session_destroy(struct lttng_session *session)
333 {
334 struct lttng_channel *chan, *tmpchan;
335 struct lttng_kernel_event_recorder_private *event_recorder_priv, *tmpevent_recorder_priv;
336 struct lttng_metadata_stream *metadata_stream;
337 struct lttng_event_enabler *event_enabler, *tmp_event_enabler;
338 int ret;
339
340 mutex_lock(&sessions_mutex);
341 WRITE_ONCE(session->active, 0);
342 list_for_each_entry(chan, &session->chan, list) {
343 ret = lttng_syscalls_unregister_channel(chan);
344 WARN_ON(ret);
345 }
346 list_for_each_entry(event_recorder_priv, &session->events, node) {
347 ret = _lttng_event_unregister(event_recorder_priv->pub);
348 WARN_ON(ret);
349 }
350 synchronize_trace(); /* Wait for in-flight events to complete */
351 list_for_each_entry(chan, &session->chan, list) {
352 ret = lttng_syscalls_destroy_event(chan);
353 WARN_ON(ret);
354 }
355 list_for_each_entry_safe(event_enabler, tmp_event_enabler,
356 &session->enablers_head, node)
357 lttng_event_enabler_destroy(event_enabler);
358 list_for_each_entry_safe(event_recorder_priv, tmpevent_recorder_priv, &session->events, node)
359 _lttng_event_destroy(&event_recorder_priv->pub->parent);
360 list_for_each_entry_safe(chan, tmpchan, &session->chan, list) {
361 BUG_ON(chan->channel_type == METADATA_CHANNEL);
362 _lttng_channel_destroy(chan);
363 }
364 mutex_lock(&session->metadata_cache->lock);
365 list_for_each_entry(metadata_stream, &session->metadata_cache->metadata_stream, list)
366 _lttng_metadata_channel_hangup(metadata_stream);
367 mutex_unlock(&session->metadata_cache->lock);
368 lttng_id_tracker_destroy(&session->pid_tracker, false);
369 lttng_id_tracker_destroy(&session->vpid_tracker, false);
370 lttng_id_tracker_destroy(&session->uid_tracker, false);
371 lttng_id_tracker_destroy(&session->vuid_tracker, false);
372 lttng_id_tracker_destroy(&session->gid_tracker, false);
373 lttng_id_tracker_destroy(&session->vgid_tracker, false);
374 kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
375 list_del(&session->list);
376 mutex_unlock(&sessions_mutex);
377 lttng_kvfree(session);
378 }
379
380 void lttng_event_notifier_group_destroy(
381 struct lttng_event_notifier_group *event_notifier_group)
382 {
383 struct lttng_event_notifier_enabler *event_notifier_enabler, *tmp_event_notifier_enabler;
384 struct lttng_kernel_event_notifier_private *event_notifier_priv, *tmpevent_notifier_priv;
385 int ret;
386
387 if (!event_notifier_group)
388 return;
389
390 mutex_lock(&sessions_mutex);
391
392 ret = lttng_syscalls_unregister_event_notifier_group(event_notifier_group);
393 WARN_ON(ret);
394
395 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
396 &event_notifier_group->event_notifiers_head, node) {
397 ret = _lttng_event_notifier_unregister(event_notifier_priv->pub);
398 WARN_ON(ret);
399 }
400
401 /* Wait for in-flight event notifier to complete */
402 synchronize_trace();
403
404 irq_work_sync(&event_notifier_group->wakeup_pending);
405
406 kfree(event_notifier_group->sc_filter);
407
408 list_for_each_entry_safe(event_notifier_enabler, tmp_event_notifier_enabler,
409 &event_notifier_group->enablers_head, node)
410 lttng_event_notifier_enabler_destroy(event_notifier_enabler);
411
412 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
413 &event_notifier_group->event_notifiers_head, node)
414 _lttng_event_destroy(&event_notifier_priv->pub->parent);
415
416 if (event_notifier_group->error_counter) {
417 struct lttng_counter *error_counter = event_notifier_group->error_counter;
418
419 error_counter->ops->counter_destroy(error_counter->counter);
420 module_put(error_counter->transport->owner);
421 lttng_kvfree(error_counter);
422 event_notifier_group->error_counter = NULL;
423 }
424
425 event_notifier_group->ops->channel_destroy(event_notifier_group->chan);
426 module_put(event_notifier_group->transport->owner);
427 list_del(&event_notifier_group->node);
428
429 mutex_unlock(&sessions_mutex);
430 lttng_kvfree(event_notifier_group);
431 }
432
433 int lttng_session_statedump(struct lttng_session *session)
434 {
435 int ret;
436
437 mutex_lock(&sessions_mutex);
438 ret = lttng_statedump_start(session);
439 mutex_unlock(&sessions_mutex);
440 return ret;
441 }
442
443 int lttng_session_enable(struct lttng_session *session)
444 {
445 int ret = 0;
446 struct lttng_channel *chan;
447
448 mutex_lock(&sessions_mutex);
449 if (session->active) {
450 ret = -EBUSY;
451 goto end;
452 }
453
454 /* Set transient enabler state to "enabled" */
455 session->tstate = 1;
456
457 /* We need to sync enablers with session before activation. */
458 lttng_session_sync_event_enablers(session);
459
460 /*
461 * Snapshot the number of events per channel to know the type of header
462 * we need to use.
463 */
464 list_for_each_entry(chan, &session->chan, list) {
465 if (chan->header_type)
466 continue; /* don't change it if session stop/restart */
467 if (chan->free_event_id < 31)
468 chan->header_type = 1; /* compact */
469 else
470 chan->header_type = 2; /* large */
471 }
472
473 /* Clear each stream's quiescent state. */
474 list_for_each_entry(chan, &session->chan, list) {
475 if (chan->channel_type != METADATA_CHANNEL)
476 lib_ring_buffer_clear_quiescent_channel(chan->chan);
477 }
478
479 WRITE_ONCE(session->active, 1);
480 WRITE_ONCE(session->been_active, 1);
481 ret = _lttng_session_metadata_statedump(session);
482 if (ret) {
483 WRITE_ONCE(session->active, 0);
484 goto end;
485 }
486 ret = lttng_statedump_start(session);
487 if (ret)
488 WRITE_ONCE(session->active, 0);
489 end:
490 mutex_unlock(&sessions_mutex);
491 return ret;
492 }
493
494 int lttng_session_disable(struct lttng_session *session)
495 {
496 int ret = 0;
497 struct lttng_channel *chan;
498
499 mutex_lock(&sessions_mutex);
500 if (!session->active) {
501 ret = -EBUSY;
502 goto end;
503 }
504 WRITE_ONCE(session->active, 0);
505
506 /* Set transient enabler state to "disabled" */
507 session->tstate = 0;
508 lttng_session_sync_event_enablers(session);
509
510 /* Set each stream's quiescent state. */
511 list_for_each_entry(chan, &session->chan, list) {
512 if (chan->channel_type != METADATA_CHANNEL)
513 lib_ring_buffer_set_quiescent_channel(chan->chan);
514 }
515 end:
516 mutex_unlock(&sessions_mutex);
517 return ret;
518 }
519
520 int lttng_session_metadata_regenerate(struct lttng_session *session)
521 {
522 int ret = 0;
523 struct lttng_channel *chan;
524 struct lttng_kernel_event_recorder_private *event_recorder_priv;
525 struct lttng_metadata_cache *cache = session->metadata_cache;
526 struct lttng_metadata_stream *stream;
527
528 mutex_lock(&sessions_mutex);
529 if (!session->active) {
530 ret = -EBUSY;
531 goto end;
532 }
533
534 mutex_lock(&cache->lock);
535 memset(cache->data, 0, cache->cache_alloc);
536 cache->metadata_written = 0;
537 cache->version++;
538 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list) {
539 stream->metadata_out = 0;
540 stream->metadata_in = 0;
541 }
542 mutex_unlock(&cache->lock);
543
544 session->metadata_dumped = 0;
545 list_for_each_entry(chan, &session->chan, list) {
546 chan->metadata_dumped = 0;
547 }
548
549 list_for_each_entry(event_recorder_priv, &session->events, node) {
550 event_recorder_priv->metadata_dumped = 0;
551 }
552
553 ret = _lttng_session_metadata_statedump(session);
554
555 end:
556 mutex_unlock(&sessions_mutex);
557 return ret;
558 }
559
560 int lttng_channel_enable(struct lttng_channel *channel)
561 {
562 int ret = 0;
563
564 mutex_lock(&sessions_mutex);
565 if (channel->channel_type == METADATA_CHANNEL) {
566 ret = -EPERM;
567 goto end;
568 }
569 if (channel->enabled) {
570 ret = -EEXIST;
571 goto end;
572 }
573 /* Set transient enabler state to "enabled" */
574 channel->tstate = 1;
575 lttng_session_sync_event_enablers(channel->session);
576 /* Set atomically the state to "enabled" */
577 WRITE_ONCE(channel->enabled, 1);
578 end:
579 mutex_unlock(&sessions_mutex);
580 return ret;
581 }
582
583 int lttng_channel_disable(struct lttng_channel *channel)
584 {
585 int ret = 0;
586
587 mutex_lock(&sessions_mutex);
588 if (channel->channel_type == METADATA_CHANNEL) {
589 ret = -EPERM;
590 goto end;
591 }
592 if (!channel->enabled) {
593 ret = -EEXIST;
594 goto end;
595 }
596 /* Set atomically the state to "disabled" */
597 WRITE_ONCE(channel->enabled, 0);
598 /* Set transient enabler state to "enabled" */
599 channel->tstate = 0;
600 lttng_session_sync_event_enablers(channel->session);
601 end:
602 mutex_unlock(&sessions_mutex);
603 return ret;
604 }
605
606 int lttng_event_enable(struct lttng_kernel_event_common *event)
607 {
608 int ret = 0;
609
610 mutex_lock(&sessions_mutex);
611 switch (event->type) {
612 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
613 {
614 struct lttng_kernel_event_recorder *event_recorder =
615 container_of(event, struct lttng_kernel_event_recorder, parent);
616
617 if (event_recorder->chan->channel_type == METADATA_CHANNEL) {
618 ret = -EPERM;
619 goto end;
620 }
621 break;
622 }
623 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
624 switch (event->priv->instrumentation) {
625 case LTTNG_KERNEL_ABI_KRETPROBE:
626 ret = -EINVAL;
627 goto end;
628 default:
629 break;
630 }
631 break;
632 default:
633 break;
634 }
635
636 if (event->enabled) {
637 ret = -EEXIST;
638 goto end;
639 }
640 switch (event->priv->instrumentation) {
641 case LTTNG_KERNEL_ABI_TRACEPOINT: /* Fall-through */
642 case LTTNG_KERNEL_ABI_SYSCALL:
643 ret = -EINVAL;
644 break;
645
646 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
647 case LTTNG_KERNEL_ABI_UPROBE:
648 WRITE_ONCE(event->enabled, 1);
649 break;
650
651 case LTTNG_KERNEL_ABI_KRETPROBE:
652 ret = lttng_kretprobes_event_enable_state(event, 1);
653 break;
654
655 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
656 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
657 default:
658 WARN_ON_ONCE(1);
659 ret = -EINVAL;
660 }
661 end:
662 mutex_unlock(&sessions_mutex);
663 return ret;
664 }
665
666 int lttng_event_disable(struct lttng_kernel_event_common *event)
667 {
668 int ret = 0;
669
670 mutex_lock(&sessions_mutex);
671 switch (event->type) {
672 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
673 {
674 struct lttng_kernel_event_recorder *event_recorder =
675 container_of(event, struct lttng_kernel_event_recorder, parent);
676
677 if (event_recorder->chan->channel_type == METADATA_CHANNEL) {
678 ret = -EPERM;
679 goto end;
680 }
681 break;
682 }
683 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
684 switch (event->priv->instrumentation) {
685 case LTTNG_KERNEL_ABI_KRETPROBE:
686 ret = -EINVAL;
687 goto end;
688 default:
689 break;
690 }
691 break;
692 default:
693 break;
694 }
695
696 if (!event->enabled) {
697 ret = -EEXIST;
698 goto end;
699 }
700 switch (event->priv->instrumentation) {
701 case LTTNG_KERNEL_ABI_TRACEPOINT: /* Fall-through */
702 case LTTNG_KERNEL_ABI_SYSCALL:
703 ret = -EINVAL;
704 break;
705
706 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
707 case LTTNG_KERNEL_ABI_UPROBE:
708 WRITE_ONCE(event->enabled, 0);
709 break;
710
711 case LTTNG_KERNEL_ABI_KRETPROBE:
712 ret = lttng_kretprobes_event_enable_state(event, 0);
713 break;
714
715 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
716 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
717 default:
718 WARN_ON_ONCE(1);
719 ret = -EINVAL;
720 }
721 end:
722 mutex_unlock(&sessions_mutex);
723 return ret;
724 }
725
726 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
727 const char *transport_name,
728 void *buf_addr,
729 size_t subbuf_size, size_t num_subbuf,
730 unsigned int switch_timer_interval,
731 unsigned int read_timer_interval,
732 enum channel_type channel_type)
733 {
734 struct lttng_channel *chan;
735 struct lttng_transport *transport = NULL;
736
737 mutex_lock(&sessions_mutex);
738 if (session->been_active && channel_type != METADATA_CHANNEL)
739 goto active; /* Refuse to add channel to active session */
740 transport = lttng_transport_find(transport_name);
741 if (!transport) {
742 printk(KERN_WARNING "LTTng: transport %s not found\n",
743 transport_name);
744 goto notransport;
745 }
746 if (!try_module_get(transport->owner)) {
747 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
748 goto notransport;
749 }
750 chan = kzalloc(sizeof(struct lttng_channel), GFP_KERNEL);
751 if (!chan)
752 goto nomem;
753 chan->session = session;
754 chan->id = session->free_chan_id++;
755 chan->ops = &transport->ops;
756 /*
757 * Note: the channel creation op already writes into the packet
758 * headers. Therefore the "chan" information used as input
759 * should be already accessible.
760 */
761 chan->chan = transport->ops.channel_create(transport_name,
762 chan, buf_addr, subbuf_size, num_subbuf,
763 switch_timer_interval, read_timer_interval);
764 if (!chan->chan)
765 goto create_error;
766 chan->tstate = 1;
767 chan->enabled = 1;
768 chan->transport = transport;
769 chan->channel_type = channel_type;
770 list_add(&chan->list, &session->chan);
771 mutex_unlock(&sessions_mutex);
772 return chan;
773
774 create_error:
775 kfree(chan);
776 nomem:
777 if (transport)
778 module_put(transport->owner);
779 notransport:
780 active:
781 mutex_unlock(&sessions_mutex);
782 return NULL;
783 }
784
785 /*
786 * Only used internally at session destruction for per-cpu channels, and
787 * when metadata channel is released.
788 * Needs to be called with sessions mutex held.
789 */
790 static
791 void _lttng_channel_destroy(struct lttng_channel *chan)
792 {
793 chan->ops->channel_destroy(chan->chan);
794 module_put(chan->transport->owner);
795 list_del(&chan->list);
796 lttng_kernel_destroy_context(chan->ctx);
797 kfree(chan);
798 }
799
800 void lttng_metadata_channel_destroy(struct lttng_channel *chan)
801 {
802 BUG_ON(chan->channel_type != METADATA_CHANNEL);
803
804 /* Protect the metadata cache with the sessions_mutex. */
805 mutex_lock(&sessions_mutex);
806 _lttng_channel_destroy(chan);
807 mutex_unlock(&sessions_mutex);
808 }
809 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
810
811 static
812 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
813 {
814 stream->finalized = 1;
815 wake_up_interruptible(&stream->read_wait);
816 }
817
818
819 /*
820 * Supports event creation while tracing session is active.
821 * Needs to be called with sessions mutex held.
822 */
823 struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct lttng_channel *chan,
824 struct lttng_kernel_abi_event *event_param,
825 const struct lttng_kernel_event_desc *event_desc,
826 enum lttng_kernel_abi_instrumentation itype)
827 {
828 struct lttng_session *session = chan->session;
829 struct lttng_kernel_event_recorder *event_recorder;
830 struct lttng_kernel_event_recorder_private *event_recorder_priv;
831 const char *event_name;
832 struct hlist_head *head;
833 int ret;
834
835 if (chan->free_event_id == -1U) {
836 ret = -EMFILE;
837 goto full;
838 }
839
840 switch (itype) {
841 case LTTNG_KERNEL_ABI_TRACEPOINT:
842 event_name = event_desc->event_name;
843 break;
844
845 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
846 case LTTNG_KERNEL_ABI_UPROBE: /* Fall-through */
847 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
848 case LTTNG_KERNEL_ABI_SYSCALL:
849 event_name = event_param->name;
850 break;
851
852 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
853 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
854 default:
855 WARN_ON_ONCE(1);
856 ret = -EINVAL;
857 goto type_error;
858 }
859
860 head = utils_borrow_hash_table_bucket(session->events_ht.table,
861 LTTNG_EVENT_HT_SIZE, event_name);
862 lttng_hlist_for_each_entry(event_recorder_priv, head, hlist) {
863 WARN_ON_ONCE(!event_recorder_priv->parent.desc);
864 if (!strncmp(event_recorder_priv->parent.desc->event_name, event_name,
865 LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
866 && chan == event_recorder_priv->pub->chan) {
867 ret = -EEXIST;
868 goto exist;
869 }
870 }
871
872 event_recorder = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
873 if (!event_recorder) {
874 ret = -ENOMEM;
875 goto cache_error;
876 }
877 event_recorder_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
878 if (!event_recorder_priv) {
879 ret = -ENOMEM;
880 goto cache_private_error;
881 }
882 event_recorder_priv->pub = event_recorder;
883 event_recorder_priv->parent.pub = &event_recorder->parent;
884 event_recorder->priv = event_recorder_priv;
885 event_recorder->parent.priv = &event_recorder_priv->parent;
886 event_recorder->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
887
888 event_recorder->chan = chan;
889 event_recorder->priv->id = chan->free_event_id++;
890 event_recorder->priv->parent.instrumentation = itype;
891 INIT_LIST_HEAD(&event_recorder->priv->parent.filter_bytecode_runtime_head);
892 INIT_LIST_HEAD(&event_recorder->priv->parent.enablers_ref_head);
893
894 switch (itype) {
895 case LTTNG_KERNEL_ABI_TRACEPOINT:
896 /* Event will be enabled by enabler sync. */
897 event_recorder->parent.enabled = 0;
898 event_recorder->priv->parent.registered = 0;
899 event_recorder->priv->parent.desc = lttng_event_desc_get(event_name);
900 if (!event_recorder->priv->parent.desc) {
901 ret = -ENOENT;
902 goto register_error;
903 }
904 /* Populate lttng_event structure before event registration. */
905 smp_wmb();
906 break;
907
908 case LTTNG_KERNEL_ABI_KPROBE:
909 /*
910 * Needs to be explicitly enabled after creation, since
911 * we may want to apply filters.
912 */
913 event_recorder->parent.enabled = 0;
914 event_recorder->priv->parent.registered = 1;
915 /*
916 * Populate lttng_event structure before event
917 * registration.
918 */
919 smp_wmb();
920 ret = lttng_kprobes_register_event(event_name,
921 event_param->u.kprobe.symbol_name,
922 event_param->u.kprobe.offset,
923 event_param->u.kprobe.addr,
924 event_recorder);
925 if (ret) {
926 ret = -EINVAL;
927 goto register_error;
928 }
929 ret = try_module_get(event_recorder->priv->parent.desc->owner);
930 WARN_ON_ONCE(!ret);
931 break;
932
933 case LTTNG_KERNEL_ABI_KRETPROBE:
934 {
935 struct lttng_kernel_event_recorder *event_recorder_return;
936 struct lttng_kernel_event_recorder_private *event_recorder_return_priv;
937
938 /* kretprobe defines 2 events */
939 /*
940 * Needs to be explicitly enabled after creation, since
941 * we may want to apply filters.
942 */
943 event_recorder->parent.enabled = 0;
944 event_recorder->priv->parent.registered = 1;
945
946 event_recorder_return = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
947 if (!event_recorder_return) {
948 ret = -ENOMEM;
949 goto register_error;
950 }
951 event_recorder_return_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
952 if (!event_recorder_return_priv) {
953 kmem_cache_free(event_recorder_cache, event_recorder_return);
954 ret = -ENOMEM;
955 goto register_error;
956 }
957 event_recorder_return_priv->pub = event_recorder_return;
958 event_recorder_return_priv->parent.pub = &event_recorder_return->parent;
959 event_recorder_return->priv = event_recorder_return_priv;
960 event_recorder_return->parent.priv = &event_recorder_return_priv->parent;
961 event_recorder_return->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
962
963 event_recorder_return->chan = chan;
964 event_recorder_return->priv->id = chan->free_event_id++;
965 event_recorder_return->priv->parent.instrumentation = itype;
966 event_recorder_return->parent.enabled = 0;
967 event_recorder_return->priv->parent.registered = 1;
968 INIT_LIST_HEAD(&event_recorder_return->priv->parent.filter_bytecode_runtime_head);
969 INIT_LIST_HEAD(&event_recorder_return->priv->parent.enablers_ref_head);
970 /*
971 * Populate lttng_event structure before kretprobe registration.
972 */
973 smp_wmb();
974 ret = lttng_kretprobes_register(event_name,
975 event_param->u.kretprobe.symbol_name,
976 event_param->u.kretprobe.offset,
977 event_param->u.kretprobe.addr,
978 event_recorder, event_recorder_return);
979 if (ret) {
980 kmem_cache_free(event_recorder_private_cache, event_recorder_return_priv);
981 kmem_cache_free(event_recorder_cache, event_recorder_return);
982 ret = -EINVAL;
983 goto register_error;
984 }
985 /* Take 2 refs on the module: one per event. */
986 ret = try_module_get(event_recorder->priv->parent.desc->owner);
987 WARN_ON_ONCE(!ret);
988 ret = try_module_get(event_recorder_return->priv->parent.desc->owner);
989 WARN_ON_ONCE(!ret);
990 ret = _lttng_event_metadata_statedump(chan->session, chan,
991 event_recorder_return);
992 WARN_ON_ONCE(ret > 0);
993 if (ret) {
994 kmem_cache_free(event_recorder_private_cache, event_recorder_return_priv);
995 kmem_cache_free(event_recorder_cache, event_recorder_return);
996 module_put(event_recorder_return->priv->parent.desc->owner);
997 module_put(event_recorder->priv->parent.desc->owner);
998 goto statedump_error;
999 }
1000 list_add(&event_recorder_return->priv->node, &chan->session->events);
1001 break;
1002 }
1003
1004 case LTTNG_KERNEL_ABI_SYSCALL:
1005 /*
1006 * Needs to be explicitly enabled after creation, since
1007 * we may want to apply filters.
1008 */
1009 event_recorder->parent.enabled = 0;
1010 event_recorder->priv->parent.registered = 0;
1011 event_recorder->priv->parent.desc = event_desc;
1012 switch (event_param->u.syscall.entryexit) {
1013 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1014 ret = -EINVAL;
1015 goto register_error;
1016 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1017 event_recorder->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1018 break;
1019 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1020 event_recorder->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1021 break;
1022 }
1023 switch (event_param->u.syscall.abi) {
1024 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1025 ret = -EINVAL;
1026 goto register_error;
1027 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1028 event_recorder->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1029 break;
1030 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1031 event_recorder->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1032 break;
1033 }
1034 if (!event_recorder->priv->parent.desc) {
1035 ret = -EINVAL;
1036 goto register_error;
1037 }
1038 break;
1039
1040 case LTTNG_KERNEL_ABI_UPROBE:
1041 /*
1042 * Needs to be explicitly enabled after creation, since
1043 * we may want to apply filters.
1044 */
1045 event_recorder->parent.enabled = 0;
1046 event_recorder->priv->parent.registered = 1;
1047
1048 /*
1049 * Populate lttng_event structure before event
1050 * registration.
1051 */
1052 smp_wmb();
1053
1054 ret = lttng_uprobes_register_event(event_param->name,
1055 event_param->u.uprobe.fd,
1056 event_recorder);
1057 if (ret)
1058 goto register_error;
1059 ret = try_module_get(event_recorder->priv->parent.desc->owner);
1060 WARN_ON_ONCE(!ret);
1061 break;
1062
1063 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1064 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1065 default:
1066 WARN_ON_ONCE(1);
1067 ret = -EINVAL;
1068 goto register_error;
1069 }
1070 ret = _lttng_event_metadata_statedump(chan->session, chan, event_recorder);
1071 WARN_ON_ONCE(ret > 0);
1072 if (ret) {
1073 goto statedump_error;
1074 }
1075 hlist_add_head(&event_recorder->priv->hlist, head);
1076 list_add(&event_recorder->priv->node, &chan->session->events);
1077 return event_recorder;
1078
1079 statedump_error:
1080 /* If a statedump error occurs, events will not be readable. */
1081 register_error:
1082 kmem_cache_free(event_recorder_private_cache, event_recorder_priv);
1083 cache_private_error:
1084 kmem_cache_free(event_recorder_cache, event_recorder);
1085 cache_error:
1086 exist:
1087 type_error:
1088 full:
1089 return ERR_PTR(ret);
1090 }
1091
1092 struct lttng_kernel_event_notifier *_lttng_event_notifier_create(
1093 const struct lttng_kernel_event_desc *event_desc,
1094 uint64_t token, uint64_t error_counter_index,
1095 struct lttng_event_notifier_group *event_notifier_group,
1096 struct lttng_kernel_abi_event_notifier *event_notifier_param,
1097 enum lttng_kernel_abi_instrumentation itype)
1098 {
1099 struct lttng_kernel_event_notifier *event_notifier;
1100 struct lttng_kernel_event_notifier_private *event_notifier_priv;
1101 struct lttng_counter *error_counter;
1102 const char *event_name;
1103 struct hlist_head *head;
1104 int ret;
1105
1106 switch (itype) {
1107 case LTTNG_KERNEL_ABI_TRACEPOINT:
1108 event_name = event_desc->event_name;
1109 break;
1110
1111 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
1112 case LTTNG_KERNEL_ABI_UPROBE: /* Fall-through */
1113 case LTTNG_KERNEL_ABI_SYSCALL:
1114 event_name = event_notifier_param->event.name;
1115 break;
1116
1117 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
1118 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1119 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1120 default:
1121 WARN_ON_ONCE(1);
1122 ret = -EINVAL;
1123 goto type_error;
1124 }
1125
1126 head = utils_borrow_hash_table_bucket(event_notifier_group->event_notifiers_ht.table,
1127 LTTNG_EVENT_NOTIFIER_HT_SIZE, event_name);
1128 lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
1129 WARN_ON_ONCE(!event_notifier_priv->parent.desc);
1130 if (!strncmp(event_notifier_priv->parent.desc->event_name, event_name,
1131 LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
1132 && event_notifier_group == event_notifier_priv->group
1133 && token == event_notifier_priv->parent.user_token) {
1134 ret = -EEXIST;
1135 goto exist;
1136 }
1137 }
1138
1139 event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
1140 if (!event_notifier) {
1141 ret = -ENOMEM;
1142 goto cache_error;
1143 }
1144 event_notifier_priv = kmem_cache_zalloc(event_notifier_private_cache, GFP_KERNEL);
1145 if (!event_notifier_priv) {
1146 ret = -ENOMEM;
1147 goto cache_private_error;
1148 }
1149 event_notifier_priv->pub = event_notifier;
1150 event_notifier_priv->parent.pub = &event_notifier->parent;
1151 event_notifier->priv = event_notifier_priv;
1152 event_notifier->parent.priv = &event_notifier_priv->parent;
1153 event_notifier->parent.type = LTTNG_KERNEL_EVENT_TYPE_NOTIFIER;
1154
1155 event_notifier->priv->group = event_notifier_group;
1156 event_notifier->priv->parent.user_token = token;
1157 event_notifier->priv->error_counter_index = error_counter_index;
1158 event_notifier->priv->num_captures = 0;
1159 event_notifier->priv->parent.instrumentation = itype;
1160 event_notifier->notification_send = lttng_event_notifier_notification_send;
1161 INIT_LIST_HEAD(&event_notifier->priv->parent.filter_bytecode_runtime_head);
1162 INIT_LIST_HEAD(&event_notifier->priv->parent.enablers_ref_head);
1163 INIT_LIST_HEAD(&event_notifier->priv->capture_bytecode_runtime_head);
1164
1165 switch (itype) {
1166 case LTTNG_KERNEL_ABI_TRACEPOINT:
1167 /* Event will be enabled by enabler sync. */
1168 event_notifier->parent.enabled = 0;
1169 event_notifier->priv->parent.registered = 0;
1170 event_notifier->priv->parent.desc = lttng_event_desc_get(event_name);
1171 if (!event_notifier->priv->parent.desc) {
1172 ret = -ENOENT;
1173 goto register_error;
1174 }
1175 /* Populate lttng_event_notifier structure before event registration. */
1176 smp_wmb();
1177 break;
1178
1179 case LTTNG_KERNEL_ABI_KPROBE:
1180 /*
1181 * Needs to be explicitly enabled after creation, since
1182 * we may want to apply filters.
1183 */
1184 event_notifier->parent.enabled = 0;
1185 event_notifier->priv->parent.registered = 1;
1186 /*
1187 * Populate lttng_event_notifier structure before event
1188 * registration.
1189 */
1190 smp_wmb();
1191 ret = lttng_kprobes_register_event_notifier(
1192 event_notifier_param->event.u.kprobe.symbol_name,
1193 event_notifier_param->event.u.kprobe.offset,
1194 event_notifier_param->event.u.kprobe.addr,
1195 event_notifier);
1196 if (ret) {
1197 ret = -EINVAL;
1198 goto register_error;
1199 }
1200 ret = try_module_get(event_notifier->priv->parent.desc->owner);
1201 WARN_ON_ONCE(!ret);
1202 break;
1203
1204 case LTTNG_KERNEL_ABI_SYSCALL:
1205 /*
1206 * Needs to be explicitly enabled after creation, since
1207 * we may want to apply filters.
1208 */
1209 event_notifier->parent.enabled = 0;
1210 event_notifier->priv->parent.registered = 0;
1211 event_notifier->priv->parent.desc = event_desc;
1212 switch (event_notifier_param->event.u.syscall.entryexit) {
1213 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1214 ret = -EINVAL;
1215 goto register_error;
1216 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1217 event_notifier->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1218 break;
1219 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1220 event_notifier->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1221 break;
1222 }
1223 switch (event_notifier_param->event.u.syscall.abi) {
1224 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1225 ret = -EINVAL;
1226 goto register_error;
1227 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1228 event_notifier->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1229 break;
1230 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1231 event_notifier->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1232 break;
1233 }
1234
1235 if (!event_notifier->priv->parent.desc) {
1236 ret = -EINVAL;
1237 goto register_error;
1238 }
1239 break;
1240
1241 case LTTNG_KERNEL_ABI_UPROBE:
1242 /*
1243 * Needs to be explicitly enabled after creation, since
1244 * we may want to apply filters.
1245 */
1246 event_notifier->parent.enabled = 0;
1247 event_notifier->priv->parent.registered = 1;
1248
1249 /*
1250 * Populate lttng_event_notifier structure before
1251 * event_notifier registration.
1252 */
1253 smp_wmb();
1254
1255 ret = lttng_uprobes_register_event_notifier(
1256 event_notifier_param->event.name,
1257 event_notifier_param->event.u.uprobe.fd,
1258 event_notifier);
1259 if (ret)
1260 goto register_error;
1261 ret = try_module_get(event_notifier->priv->parent.desc->owner);
1262 WARN_ON_ONCE(!ret);
1263 break;
1264
1265 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
1266 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1267 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1268 default:
1269 WARN_ON_ONCE(1);
1270 ret = -EINVAL;
1271 goto register_error;
1272 }
1273
1274 list_add(&event_notifier->priv->node, &event_notifier_group->event_notifiers_head);
1275 hlist_add_head(&event_notifier->priv->hlist, head);
1276
1277 /*
1278 * Clear the error counter bucket. The sessiond keeps track of which
1279 * bucket is currently in use. We trust it. The session lock
1280 * synchronizes against concurrent creation of the error
1281 * counter.
1282 */
1283 error_counter = event_notifier_group->error_counter;
1284 if (error_counter) {
1285 size_t dimension_index[1];
1286
1287 /*
1288 * Check that the index is within the boundary of the counter.
1289 */
1290 if (event_notifier->priv->error_counter_index >= event_notifier_group->error_counter_len) {
1291 printk(KERN_INFO "LTTng: event_notifier: Error counter index out-of-bound: counter-len=%zu, index=%llu\n",
1292 event_notifier_group->error_counter_len, event_notifier->priv->error_counter_index);
1293 ret = -EINVAL;
1294 goto register_error;
1295 }
1296
1297 dimension_index[0] = event_notifier->priv->error_counter_index;
1298 ret = error_counter->ops->counter_clear(error_counter->counter, dimension_index);
1299 if (ret) {
1300 printk(KERN_INFO "LTTng: event_notifier: Unable to clear error counter bucket %llu\n",
1301 event_notifier->priv->error_counter_index);
1302 goto register_error;
1303 }
1304 }
1305
1306 return event_notifier;
1307
1308 register_error:
1309 kmem_cache_free(event_notifier_private_cache, event_notifier_priv);
1310 cache_private_error:
1311 kmem_cache_free(event_notifier_cache, event_notifier);
1312 cache_error:
1313 exist:
1314 type_error:
1315 return ERR_PTR(ret);
1316 }
1317
1318 int lttng_kernel_counter_read(struct lttng_counter *counter,
1319 const size_t *dim_indexes, int32_t cpu,
1320 int64_t *val, bool *overflow, bool *underflow)
1321 {
1322 return counter->ops->counter_read(counter->counter, dim_indexes,
1323 cpu, val, overflow, underflow);
1324 }
1325
1326 int lttng_kernel_counter_aggregate(struct lttng_counter *counter,
1327 const size_t *dim_indexes, int64_t *val,
1328 bool *overflow, bool *underflow)
1329 {
1330 return counter->ops->counter_aggregate(counter->counter, dim_indexes,
1331 val, overflow, underflow);
1332 }
1333
1334 int lttng_kernel_counter_clear(struct lttng_counter *counter,
1335 const size_t *dim_indexes)
1336 {
1337 return counter->ops->counter_clear(counter->counter, dim_indexes);
1338 }
1339
1340 struct lttng_kernel_event_recorder *lttng_kernel_event_recorder_create(struct lttng_channel *chan,
1341 struct lttng_kernel_abi_event *event_param,
1342 const struct lttng_kernel_event_desc *event_desc,
1343 enum lttng_kernel_abi_instrumentation itype)
1344 {
1345 struct lttng_kernel_event_recorder *event;
1346
1347 mutex_lock(&sessions_mutex);
1348 event = _lttng_kernel_event_recorder_create(chan, event_param, event_desc, itype);
1349 mutex_unlock(&sessions_mutex);
1350 return event;
1351 }
1352
1353 struct lttng_kernel_event_notifier *lttng_event_notifier_create(
1354 const struct lttng_kernel_event_desc *event_desc,
1355 uint64_t id, uint64_t error_counter_index,
1356 struct lttng_event_notifier_group *event_notifier_group,
1357 struct lttng_kernel_abi_event_notifier *event_notifier_param,
1358 enum lttng_kernel_abi_instrumentation itype)
1359 {
1360 struct lttng_kernel_event_notifier *event_notifier;
1361
1362 mutex_lock(&sessions_mutex);
1363 event_notifier = _lttng_event_notifier_create(event_desc, id,
1364 error_counter_index, event_notifier_group,
1365 event_notifier_param, itype);
1366 mutex_unlock(&sessions_mutex);
1367 return event_notifier;
1368 }
1369
1370 /* Only used for tracepoints for now. */
1371 static
1372 void register_event(struct lttng_kernel_event_recorder *event_recorder)
1373 {
1374 const struct lttng_kernel_event_desc *desc;
1375 int ret = -EINVAL;
1376
1377 if (event_recorder->priv->parent.registered)
1378 return;
1379
1380 desc = event_recorder->priv->parent.desc;
1381 switch (event_recorder->priv->parent.instrumentation) {
1382 case LTTNG_KERNEL_ABI_TRACEPOINT:
1383 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1384 desc->probe_callback,
1385 event_recorder);
1386 break;
1387
1388 case LTTNG_KERNEL_ABI_SYSCALL:
1389 ret = lttng_syscall_filter_enable_event(event_recorder->chan, event_recorder);
1390 break;
1391
1392 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
1393 case LTTNG_KERNEL_ABI_UPROBE: /* Fall-through */
1394 case LTTNG_KERNEL_ABI_KRETPROBE:
1395 ret = 0;
1396 break;
1397
1398 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1399 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1400 default:
1401 WARN_ON_ONCE(1);
1402 }
1403 if (!ret)
1404 event_recorder->priv->parent.registered = 1;
1405 }
1406
1407 /*
1408 * Only used internally at session destruction.
1409 */
1410 int _lttng_event_unregister(struct lttng_kernel_event_recorder *event_recorder)
1411 {
1412 struct lttng_kernel_event_common_private *event_priv = &event_recorder->priv->parent;
1413 const struct lttng_kernel_event_desc *desc;
1414 int ret = -EINVAL;
1415
1416 if (!event_priv->registered)
1417 return 0;
1418
1419 desc = event_priv->desc;
1420 switch (event_priv->instrumentation) {
1421 case LTTNG_KERNEL_ABI_TRACEPOINT:
1422 ret = lttng_wrapper_tracepoint_probe_unregister(event_priv->desc->event_kname,
1423 event_priv->desc->probe_callback,
1424 event_recorder);
1425 break;
1426
1427 case LTTNG_KERNEL_ABI_KPROBE:
1428 lttng_kprobes_unregister_event(event_recorder);
1429 ret = 0;
1430 break;
1431
1432 case LTTNG_KERNEL_ABI_KRETPROBE:
1433 lttng_kretprobes_unregister(event_recorder);
1434 ret = 0;
1435 break;
1436
1437 case LTTNG_KERNEL_ABI_SYSCALL:
1438 ret = lttng_syscall_filter_disable_event(event_recorder->chan, event_recorder);
1439 break;
1440
1441 case LTTNG_KERNEL_ABI_NOOP:
1442 ret = 0;
1443 break;
1444
1445 case LTTNG_KERNEL_ABI_UPROBE:
1446 lttng_uprobes_unregister_event(event_recorder);
1447 ret = 0;
1448 break;
1449
1450 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1451 default:
1452 WARN_ON_ONCE(1);
1453 }
1454 if (!ret)
1455 event_priv->registered = 0;
1456 return ret;
1457 }
1458
1459 /* Only used for tracepoints for now. */
1460 static
1461 void register_event_notifier(struct lttng_kernel_event_notifier *event_notifier)
1462 {
1463 const struct lttng_kernel_event_desc *desc;
1464 int ret = -EINVAL;
1465
1466 if (event_notifier->priv->parent.registered)
1467 return;
1468
1469 desc = event_notifier->priv->parent.desc;
1470 switch (event_notifier->priv->parent.instrumentation) {
1471 case LTTNG_KERNEL_ABI_TRACEPOINT:
1472 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1473 desc->probe_callback,
1474 event_notifier);
1475 break;
1476
1477 case LTTNG_KERNEL_ABI_SYSCALL:
1478 ret = lttng_syscall_filter_enable_event_notifier(event_notifier);
1479 break;
1480
1481 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
1482 case LTTNG_KERNEL_ABI_UPROBE:
1483 ret = 0;
1484 break;
1485
1486 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
1487 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1488 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1489 default:
1490 WARN_ON_ONCE(1);
1491 }
1492 if (!ret)
1493 event_notifier->priv->parent.registered = 1;
1494 }
1495
1496 static
1497 int _lttng_event_notifier_unregister(
1498 struct lttng_kernel_event_notifier *event_notifier)
1499 {
1500 const struct lttng_kernel_event_desc *desc;
1501 int ret = -EINVAL;
1502
1503 if (!event_notifier->priv->parent.registered)
1504 return 0;
1505
1506 desc = event_notifier->priv->parent.desc;
1507 switch (event_notifier->priv->parent.instrumentation) {
1508 case LTTNG_KERNEL_ABI_TRACEPOINT:
1509 ret = lttng_wrapper_tracepoint_probe_unregister(event_notifier->priv->parent.desc->event_kname,
1510 event_notifier->priv->parent.desc->probe_callback,
1511 event_notifier);
1512 break;
1513
1514 case LTTNG_KERNEL_ABI_KPROBE:
1515 lttng_kprobes_unregister_event_notifier(event_notifier);
1516 ret = 0;
1517 break;
1518
1519 case LTTNG_KERNEL_ABI_UPROBE:
1520 lttng_uprobes_unregister_event_notifier(event_notifier);
1521 ret = 0;
1522 break;
1523
1524 case LTTNG_KERNEL_ABI_SYSCALL:
1525 ret = lttng_syscall_filter_disable_event_notifier(event_notifier);
1526 break;
1527
1528 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
1529 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1530 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1531 default:
1532 WARN_ON_ONCE(1);
1533 }
1534 if (!ret)
1535 event_notifier->priv->parent.registered = 0;
1536 return ret;
1537 }
1538
1539 /*
1540 * Only used internally at session destruction.
1541 */
1542 static
1543 void _lttng_event_destroy(struct lttng_kernel_event_common *event)
1544 {
1545 struct lttng_kernel_event_common_private *event_priv = event->priv;
1546 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1547
1548 lttng_free_event_filter_runtime(event);
1549 /* Free event enabler refs */
1550 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1551 &event_priv->enablers_ref_head, node)
1552 kfree(enabler_ref);
1553
1554 switch (event->type) {
1555 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1556 {
1557 struct lttng_kernel_event_recorder *event_recorder =
1558 container_of(event, struct lttng_kernel_event_recorder, parent);
1559
1560 switch (event_priv->instrumentation) {
1561 case LTTNG_KERNEL_ABI_TRACEPOINT:
1562 lttng_event_desc_put(event_priv->desc);
1563 break;
1564
1565 case LTTNG_KERNEL_ABI_KPROBE:
1566 module_put(event_priv->desc->owner);
1567 lttng_kprobes_destroy_event_private(event_recorder);
1568 break;
1569
1570 case LTTNG_KERNEL_ABI_KRETPROBE:
1571 module_put(event_priv->desc->owner);
1572 lttng_kretprobes_destroy_private(event_recorder);
1573 break;
1574
1575 case LTTNG_KERNEL_ABI_SYSCALL:
1576 break;
1577
1578 case LTTNG_KERNEL_ABI_UPROBE:
1579 module_put(event_priv->desc->owner);
1580 lttng_uprobes_destroy_event_private(event_recorder);
1581 break;
1582
1583 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1584 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1585 default:
1586 WARN_ON_ONCE(1);
1587 }
1588 list_del(&event_recorder->priv->node);
1589 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
1590 kmem_cache_free(event_recorder_cache, event_recorder);
1591 break;
1592 }
1593 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1594 {
1595 struct lttng_kernel_event_notifier *event_notifier =
1596 container_of(event, struct lttng_kernel_event_notifier, parent);
1597
1598 switch (event_notifier->priv->parent.instrumentation) {
1599 case LTTNG_KERNEL_ABI_TRACEPOINT:
1600 lttng_event_desc_put(event_notifier->priv->parent.desc);
1601 break;
1602
1603 case LTTNG_KERNEL_ABI_KPROBE:
1604 module_put(event_notifier->priv->parent.desc->owner);
1605 lttng_kprobes_destroy_event_notifier_private(event_notifier);
1606 break;
1607
1608 case LTTNG_KERNEL_ABI_SYSCALL:
1609 break;
1610
1611 case LTTNG_KERNEL_ABI_UPROBE:
1612 module_put(event_notifier->priv->parent.desc->owner);
1613 lttng_uprobes_destroy_event_notifier_private(event_notifier);
1614 break;
1615
1616 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
1617 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1618 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1619 default:
1620 WARN_ON_ONCE(1);
1621 }
1622 list_del(&event_notifier->priv->node);
1623 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
1624 kmem_cache_free(event_notifier_cache, event_notifier);
1625 break;
1626 }
1627 default:
1628 WARN_ON_ONCE(1);
1629 }
1630 }
1631
1632 struct lttng_id_tracker *get_tracker(struct lttng_session *session,
1633 enum tracker_type tracker_type)
1634 {
1635 switch (tracker_type) {
1636 case TRACKER_PID:
1637 return &session->pid_tracker;
1638 case TRACKER_VPID:
1639 return &session->vpid_tracker;
1640 case TRACKER_UID:
1641 return &session->uid_tracker;
1642 case TRACKER_VUID:
1643 return &session->vuid_tracker;
1644 case TRACKER_GID:
1645 return &session->gid_tracker;
1646 case TRACKER_VGID:
1647 return &session->vgid_tracker;
1648 default:
1649 WARN_ON_ONCE(1);
1650 return NULL;
1651 }
1652 }
1653
1654 int lttng_session_track_id(struct lttng_session *session,
1655 enum tracker_type tracker_type, int id)
1656 {
1657 struct lttng_id_tracker *tracker;
1658 int ret;
1659
1660 tracker = get_tracker(session, tracker_type);
1661 if (!tracker)
1662 return -EINVAL;
1663 if (id < -1)
1664 return -EINVAL;
1665 mutex_lock(&sessions_mutex);
1666 if (id == -1) {
1667 /* track all ids: destroy tracker. */
1668 lttng_id_tracker_destroy(tracker, true);
1669 ret = 0;
1670 } else {
1671 ret = lttng_id_tracker_add(tracker, id);
1672 }
1673 mutex_unlock(&sessions_mutex);
1674 return ret;
1675 }
1676
1677 int lttng_session_untrack_id(struct lttng_session *session,
1678 enum tracker_type tracker_type, int id)
1679 {
1680 struct lttng_id_tracker *tracker;
1681 int ret;
1682
1683 tracker = get_tracker(session, tracker_type);
1684 if (!tracker)
1685 return -EINVAL;
1686 if (id < -1)
1687 return -EINVAL;
1688 mutex_lock(&sessions_mutex);
1689 if (id == -1) {
1690 /* untrack all ids: replace by empty tracker. */
1691 ret = lttng_id_tracker_empty_set(tracker);
1692 } else {
1693 ret = lttng_id_tracker_del(tracker, id);
1694 }
1695 mutex_unlock(&sessions_mutex);
1696 return ret;
1697 }
1698
1699 static
1700 void *id_list_start(struct seq_file *m, loff_t *pos)
1701 {
1702 struct lttng_id_tracker *id_tracker = m->private;
1703 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1704 struct lttng_id_hash_node *e;
1705 int iter = 0, i;
1706
1707 mutex_lock(&sessions_mutex);
1708 if (id_tracker_p) {
1709 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1710 struct hlist_head *head = &id_tracker_p->id_hash[i];
1711
1712 lttng_hlist_for_each_entry(e, head, hlist) {
1713 if (iter++ >= *pos)
1714 return e;
1715 }
1716 }
1717 } else {
1718 /* ID tracker disabled. */
1719 if (iter >= *pos && iter == 0) {
1720 return id_tracker_p; /* empty tracker */
1721 }
1722 iter++;
1723 }
1724 /* End of list */
1725 return NULL;
1726 }
1727
1728 /* Called with sessions_mutex held. */
1729 static
1730 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1731 {
1732 struct lttng_id_tracker *id_tracker = m->private;
1733 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1734 struct lttng_id_hash_node *e;
1735 int iter = 0, i;
1736
1737 (*ppos)++;
1738 if (id_tracker_p) {
1739 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1740 struct hlist_head *head = &id_tracker_p->id_hash[i];
1741
1742 lttng_hlist_for_each_entry(e, head, hlist) {
1743 if (iter++ >= *ppos)
1744 return e;
1745 }
1746 }
1747 } else {
1748 /* ID tracker disabled. */
1749 if (iter >= *ppos && iter == 0)
1750 return p; /* empty tracker */
1751 iter++;
1752 }
1753
1754 /* End of list */
1755 return NULL;
1756 }
1757
1758 static
1759 void id_list_stop(struct seq_file *m, void *p)
1760 {
1761 mutex_unlock(&sessions_mutex);
1762 }
1763
1764 static
1765 int id_list_show(struct seq_file *m, void *p)
1766 {
1767 struct lttng_id_tracker *id_tracker = m->private;
1768 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1769 int id;
1770
1771 if (p == id_tracker_p) {
1772 /* Tracker disabled. */
1773 id = -1;
1774 } else {
1775 const struct lttng_id_hash_node *e = p;
1776
1777 id = lttng_id_tracker_get_node_id(e);
1778 }
1779 switch (id_tracker->tracker_type) {
1780 case TRACKER_PID:
1781 seq_printf(m, "process { pid = %d; };\n", id);
1782 break;
1783 case TRACKER_VPID:
1784 seq_printf(m, "process { vpid = %d; };\n", id);
1785 break;
1786 case TRACKER_UID:
1787 seq_printf(m, "user { uid = %d; };\n", id);
1788 break;
1789 case TRACKER_VUID:
1790 seq_printf(m, "user { vuid = %d; };\n", id);
1791 break;
1792 case TRACKER_GID:
1793 seq_printf(m, "group { gid = %d; };\n", id);
1794 break;
1795 case TRACKER_VGID:
1796 seq_printf(m, "group { vgid = %d; };\n", id);
1797 break;
1798 default:
1799 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1800 }
1801 return 0;
1802 }
1803
1804 static
1805 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1806 .start = id_list_start,
1807 .next = id_list_next,
1808 .stop = id_list_stop,
1809 .show = id_list_show,
1810 };
1811
1812 static
1813 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1814 {
1815 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1816 }
1817
1818 static
1819 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1820 {
1821 struct seq_file *m = file->private_data;
1822 struct lttng_id_tracker *id_tracker = m->private;
1823 int ret;
1824
1825 WARN_ON_ONCE(!id_tracker);
1826 ret = seq_release(inode, file);
1827 if (!ret)
1828 fput(id_tracker->session->file);
1829 return ret;
1830 }
1831
1832 const struct file_operations lttng_tracker_ids_list_fops = {
1833 .owner = THIS_MODULE,
1834 .open = lttng_tracker_ids_list_open,
1835 .read = seq_read,
1836 .llseek = seq_lseek,
1837 .release = lttng_tracker_ids_list_release,
1838 };
1839
1840 int lttng_session_list_tracker_ids(struct lttng_session *session,
1841 enum tracker_type tracker_type)
1842 {
1843 struct file *tracker_ids_list_file;
1844 struct seq_file *m;
1845 int file_fd, ret;
1846
1847 file_fd = lttng_get_unused_fd();
1848 if (file_fd < 0) {
1849 ret = file_fd;
1850 goto fd_error;
1851 }
1852
1853 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1854 &lttng_tracker_ids_list_fops,
1855 NULL, O_RDWR);
1856 if (IS_ERR(tracker_ids_list_file)) {
1857 ret = PTR_ERR(tracker_ids_list_file);
1858 goto file_error;
1859 }
1860 if (!atomic_long_add_unless(&session->file->f_count, 1, LONG_MAX)) {
1861 ret = -EOVERFLOW;
1862 goto refcount_error;
1863 }
1864 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1865 if (ret < 0)
1866 goto open_error;
1867 m = tracker_ids_list_file->private_data;
1868
1869 m->private = get_tracker(session, tracker_type);
1870 BUG_ON(!m->private);
1871 fd_install(file_fd, tracker_ids_list_file);
1872
1873 return file_fd;
1874
1875 open_error:
1876 atomic_long_dec(&session->file->f_count);
1877 refcount_error:
1878 fput(tracker_ids_list_file);
1879 file_error:
1880 put_unused_fd(file_fd);
1881 fd_error:
1882 return ret;
1883 }
1884
1885 /*
1886 * Enabler management.
1887 */
1888 static
1889 int lttng_match_enabler_star_glob(const char *desc_name,
1890 const char *pattern)
1891 {
1892 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1893 desc_name, LTTNG_SIZE_MAX))
1894 return 0;
1895 return 1;
1896 }
1897
1898 static
1899 int lttng_match_enabler_name(const char *desc_name,
1900 const char *name)
1901 {
1902 if (strcmp(desc_name, name))
1903 return 0;
1904 return 1;
1905 }
1906
1907 int lttng_desc_match_enabler(const struct lttng_kernel_event_desc *desc,
1908 struct lttng_enabler *enabler)
1909 {
1910 const char *desc_name, *enabler_name;
1911 bool compat = false, entry = false;
1912
1913 enabler_name = enabler->event_param.name;
1914 switch (enabler->event_param.instrumentation) {
1915 case LTTNG_KERNEL_ABI_TRACEPOINT:
1916 desc_name = desc->event_name;
1917 switch (enabler->format_type) {
1918 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1919 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1920 case LTTNG_ENABLER_FORMAT_NAME:
1921 return lttng_match_enabler_name(desc_name, enabler_name);
1922 default:
1923 return -EINVAL;
1924 }
1925 break;
1926
1927 case LTTNG_KERNEL_ABI_SYSCALL:
1928 desc_name = desc->event_name;
1929 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
1930 desc_name += strlen("compat_");
1931 compat = true;
1932 }
1933 if (!strncmp(desc_name, "syscall_exit_",
1934 strlen("syscall_exit_"))) {
1935 desc_name += strlen("syscall_exit_");
1936 } else if (!strncmp(desc_name, "syscall_entry_",
1937 strlen("syscall_entry_"))) {
1938 desc_name += strlen("syscall_entry_");
1939 entry = true;
1940 } else {
1941 WARN_ON_ONCE(1);
1942 return -EINVAL;
1943 }
1944 switch (enabler->event_param.u.syscall.entryexit) {
1945 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1946 break;
1947 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1948 if (!entry)
1949 return 0;
1950 break;
1951 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1952 if (entry)
1953 return 0;
1954 break;
1955 default:
1956 return -EINVAL;
1957 }
1958 switch (enabler->event_param.u.syscall.abi) {
1959 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1960 break;
1961 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1962 if (compat)
1963 return 0;
1964 break;
1965 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1966 if (!compat)
1967 return 0;
1968 break;
1969 default:
1970 return -EINVAL;
1971 }
1972 switch (enabler->event_param.u.syscall.match) {
1973 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME:
1974 switch (enabler->format_type) {
1975 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1976 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1977 case LTTNG_ENABLER_FORMAT_NAME:
1978 return lttng_match_enabler_name(desc_name, enabler_name);
1979 default:
1980 return -EINVAL;
1981 }
1982 break;
1983 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NR:
1984 return -EINVAL; /* Not implemented. */
1985 default:
1986 return -EINVAL;
1987 }
1988 break;
1989
1990 default:
1991 WARN_ON_ONCE(1);
1992 return -EINVAL;
1993 }
1994 }
1995
1996 static
1997 int lttng_event_enabler_match_event(struct lttng_event_enabler *event_enabler,
1998 struct lttng_kernel_event_recorder *event_recorder)
1999 {
2000 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(
2001 event_enabler);
2002
2003 if (base_enabler->event_param.instrumentation != event_recorder->priv->parent.instrumentation)
2004 return 0;
2005 if (lttng_desc_match_enabler(event_recorder->priv->parent.desc, base_enabler)
2006 && event_recorder->chan == event_enabler->chan)
2007 return 1;
2008 else
2009 return 0;
2010 }
2011
2012 static
2013 int lttng_event_notifier_enabler_match_event_notifier(struct lttng_event_notifier_enabler *event_notifier_enabler,
2014 struct lttng_kernel_event_notifier *event_notifier)
2015 {
2016 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(
2017 event_notifier_enabler);
2018
2019 if (base_enabler->event_param.instrumentation != event_notifier->priv->parent.instrumentation)
2020 return 0;
2021 if (lttng_desc_match_enabler(event_notifier->priv->parent.desc, base_enabler)
2022 && event_notifier->priv->group == event_notifier_enabler->group
2023 && event_notifier->priv->parent.user_token == event_notifier_enabler->base.user_token)
2024 return 1;
2025 else
2026 return 0;
2027 }
2028
2029 static
2030 struct lttng_enabler_ref *lttng_enabler_ref(
2031 struct list_head *enablers_ref_list,
2032 struct lttng_enabler *enabler)
2033 {
2034 struct lttng_enabler_ref *enabler_ref;
2035
2036 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
2037 if (enabler_ref->ref == enabler)
2038 return enabler_ref;
2039 }
2040 return NULL;
2041 }
2042
2043 static
2044 void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler *event_enabler)
2045 {
2046 struct lttng_session *session = event_enabler->chan->session;
2047 struct lttng_kernel_probe_desc *probe_desc;
2048 const struct lttng_kernel_event_desc *desc;
2049 int i;
2050 struct list_head *probe_list;
2051
2052 probe_list = lttng_get_probe_list_head();
2053 /*
2054 * For each probe event, if we find that a probe event matches
2055 * our enabler, create an associated lttng_event if not
2056 * already present.
2057 */
2058 list_for_each_entry(probe_desc, probe_list, head) {
2059 for (i = 0; i < probe_desc->nr_events; i++) {
2060 int found = 0;
2061 struct hlist_head *head;
2062 struct lttng_kernel_event_recorder_private *event_recorder_private;
2063 struct lttng_kernel_event_recorder *event_recorder;
2064
2065 desc = probe_desc->event_desc[i];
2066 if (!lttng_desc_match_enabler(desc,
2067 lttng_event_enabler_as_enabler(event_enabler)))
2068 continue;
2069
2070 /*
2071 * Check if already created.
2072 */
2073 head = utils_borrow_hash_table_bucket(
2074 session->events_ht.table, LTTNG_EVENT_HT_SIZE,
2075 desc->event_name);
2076 lttng_hlist_for_each_entry(event_recorder_private, head, hlist) {
2077 if (event_recorder_private->parent.desc == desc
2078 && event_recorder_private->pub->chan == event_enabler->chan)
2079 found = 1;
2080 }
2081 if (found)
2082 continue;
2083
2084 /*
2085 * We need to create an event for this
2086 * event probe.
2087 */
2088 event_recorder = _lttng_kernel_event_recorder_create(event_enabler->chan,
2089 NULL, desc, LTTNG_KERNEL_ABI_TRACEPOINT);
2090 if (!event_recorder) {
2091 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2092 probe_desc->event_desc[i]->event_name);
2093 }
2094 }
2095 }
2096 }
2097
2098 static
2099 void lttng_create_tracepoint_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2100 {
2101 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2102 struct lttng_kernel_probe_desc *probe_desc;
2103 const struct lttng_kernel_event_desc *desc;
2104 int i;
2105 struct list_head *probe_list;
2106
2107 probe_list = lttng_get_probe_list_head();
2108 /*
2109 * For each probe event, if we find that a probe event matches
2110 * our enabler, create an associated lttng_event_notifier if not
2111 * already present.
2112 */
2113 list_for_each_entry(probe_desc, probe_list, head) {
2114 for (i = 0; i < probe_desc->nr_events; i++) {
2115 int found = 0;
2116 struct hlist_head *head;
2117 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2118 struct lttng_kernel_event_notifier *event_notifier;
2119
2120 desc = probe_desc->event_desc[i];
2121 if (!lttng_desc_match_enabler(desc,
2122 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)))
2123 continue;
2124
2125 /*
2126 * Check if already created.
2127 */
2128 head = utils_borrow_hash_table_bucket(
2129 event_notifier_group->event_notifiers_ht.table,
2130 LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->event_name);
2131 lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
2132 if (event_notifier_priv->parent.desc == desc
2133 && event_notifier_priv->parent.user_token == event_notifier_enabler->base.user_token)
2134 found = 1;
2135 }
2136 if (found)
2137 continue;
2138
2139 /*
2140 * We need to create a event_notifier for this event probe.
2141 */
2142 event_notifier = _lttng_event_notifier_create(desc,
2143 event_notifier_enabler->base.user_token,
2144 event_notifier_enabler->error_counter_index,
2145 event_notifier_group, NULL,
2146 LTTNG_KERNEL_ABI_TRACEPOINT);
2147 if (IS_ERR(event_notifier)) {
2148 printk(KERN_INFO "Unable to create event_notifier %s\n",
2149 probe_desc->event_desc[i]->event_name);
2150 }
2151 }
2152 }
2153 }
2154
2155 static
2156 void lttng_create_syscall_event_if_missing(struct lttng_event_enabler *event_enabler)
2157 {
2158 int ret;
2159
2160 ret = lttng_syscalls_register_event(event_enabler);
2161 WARN_ON_ONCE(ret);
2162 }
2163
2164 static
2165 void lttng_create_syscall_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2166 {
2167 int ret;
2168
2169 ret = lttng_syscalls_register_event_notifier(event_notifier_enabler);
2170 WARN_ON_ONCE(ret);
2171 ret = lttng_syscalls_create_matching_event_notifiers(event_notifier_enabler);
2172 WARN_ON_ONCE(ret);
2173 }
2174
2175 /*
2176 * Create struct lttng_kernel_event_recorder if it is missing and present in the list of
2177 * tracepoint probes.
2178 * Should be called with sessions mutex held.
2179 */
2180 static
2181 void lttng_create_event_if_missing(struct lttng_event_enabler *event_enabler)
2182 {
2183 switch (event_enabler->base.event_param.instrumentation) {
2184 case LTTNG_KERNEL_ABI_TRACEPOINT:
2185 lttng_create_tracepoint_event_if_missing(event_enabler);
2186 break;
2187
2188 case LTTNG_KERNEL_ABI_SYSCALL:
2189 lttng_create_syscall_event_if_missing(event_enabler);
2190 break;
2191
2192 default:
2193 WARN_ON_ONCE(1);
2194 break;
2195 }
2196 }
2197
2198 /*
2199 * Create events associated with an event_enabler (if not already present),
2200 * and add backward reference from the event to the enabler.
2201 * Should be called with sessions mutex held.
2202 */
2203 static
2204 int lttng_event_enabler_ref_events(struct lttng_event_enabler *event_enabler)
2205 {
2206 struct lttng_channel *chan = event_enabler->chan;
2207 struct lttng_session *session = event_enabler->chan->session;
2208 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(event_enabler);
2209 struct lttng_kernel_event_recorder_private *event_recorder_priv;
2210
2211 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_ABI_SYSCALL &&
2212 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL &&
2213 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME &&
2214 !strcmp(base_enabler->event_param.name, "*")) {
2215 int enabled = base_enabler->enabled;
2216 enum lttng_kernel_abi_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2217
2218 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2219 WRITE_ONCE(chan->syscall_all_entry, enabled);
2220
2221 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2222 WRITE_ONCE(chan->syscall_all_exit, enabled);
2223 }
2224
2225 /* First ensure that probe events are created for this enabler. */
2226 lttng_create_event_if_missing(event_enabler);
2227
2228 /* For each event matching event_enabler in session event list. */
2229 list_for_each_entry(event_recorder_priv, &session->events, node) {
2230 struct lttng_kernel_event_recorder *event_recorder = event_recorder_priv->pub;
2231 struct lttng_enabler_ref *enabler_ref;
2232
2233 if (!lttng_event_enabler_match_event(event_enabler, event_recorder))
2234 continue;
2235 enabler_ref = lttng_enabler_ref(&event_recorder_priv->parent.enablers_ref_head,
2236 lttng_event_enabler_as_enabler(event_enabler));
2237 if (!enabler_ref) {
2238 /*
2239 * If no backward ref, create it.
2240 * Add backward ref from event to event_enabler.
2241 */
2242 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2243 if (!enabler_ref)
2244 return -ENOMEM;
2245 enabler_ref->ref = lttng_event_enabler_as_enabler(event_enabler);
2246 list_add(&enabler_ref->node,
2247 &event_recorder_priv->parent.enablers_ref_head);
2248 }
2249
2250 /*
2251 * Link filter bytecodes if not linked yet.
2252 */
2253 lttng_enabler_link_bytecode(event_recorder_priv->parent.desc,
2254 lttng_static_ctx,
2255 &event_recorder_priv->parent.filter_bytecode_runtime_head,
2256 &lttng_event_enabler_as_enabler(event_enabler)->filter_bytecode_head);
2257 }
2258 return 0;
2259 }
2260
2261 /*
2262 * Create struct lttng_kernel_event_notifier if it is missing and present in the list of
2263 * tracepoint probes.
2264 * Should be called with sessions mutex held.
2265 */
2266 static
2267 void lttng_create_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2268 {
2269 switch (event_notifier_enabler->base.event_param.instrumentation) {
2270 case LTTNG_KERNEL_ABI_TRACEPOINT:
2271 lttng_create_tracepoint_event_notifier_if_missing(event_notifier_enabler);
2272 break;
2273
2274 case LTTNG_KERNEL_ABI_SYSCALL:
2275 lttng_create_syscall_event_notifier_if_missing(event_notifier_enabler);
2276 break;
2277
2278 default:
2279 WARN_ON_ONCE(1);
2280 break;
2281 }
2282 }
2283
2284 /*
2285 * Create event_notifiers associated with a event_notifier enabler (if not already present).
2286 */
2287 static
2288 int lttng_event_notifier_enabler_ref_event_notifiers(
2289 struct lttng_event_notifier_enabler *event_notifier_enabler)
2290 {
2291 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2292 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2293 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2294
2295 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_ABI_SYSCALL &&
2296 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL &&
2297 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME &&
2298 !strcmp(base_enabler->event_param.name, "*")) {
2299
2300 int enabled = base_enabler->enabled;
2301 enum lttng_kernel_abi_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2302
2303 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2304 WRITE_ONCE(event_notifier_group->syscall_all_entry, enabled);
2305
2306 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2307 WRITE_ONCE(event_notifier_group->syscall_all_exit, enabled);
2308
2309 }
2310
2311 /* First ensure that probe event_notifiers are created for this enabler. */
2312 lttng_create_event_notifier_if_missing(event_notifier_enabler);
2313
2314 /* Link the created event_notifier with its associated enabler. */
2315 list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, node) {
2316 struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
2317 struct lttng_enabler_ref *enabler_ref;
2318
2319 if (!lttng_event_notifier_enabler_match_event_notifier(event_notifier_enabler, event_notifier))
2320 continue;
2321
2322 enabler_ref = lttng_enabler_ref(&event_notifier_priv->parent.enablers_ref_head,
2323 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2324 if (!enabler_ref) {
2325 /*
2326 * If no backward ref, create it.
2327 * Add backward ref from event_notifier to enabler.
2328 */
2329 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2330 if (!enabler_ref)
2331 return -ENOMEM;
2332
2333 enabler_ref->ref = lttng_event_notifier_enabler_as_enabler(
2334 event_notifier_enabler);
2335 list_add(&enabler_ref->node,
2336 &event_notifier_priv->parent.enablers_ref_head);
2337 }
2338
2339 /*
2340 * Link filter bytecodes if not linked yet.
2341 */
2342 lttng_enabler_link_bytecode(event_notifier_priv->parent.desc,
2343 lttng_static_ctx, &event_notifier_priv->parent.filter_bytecode_runtime_head,
2344 &lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->filter_bytecode_head);
2345
2346 /* Link capture bytecodes if not linked yet. */
2347 lttng_enabler_link_bytecode(event_notifier_priv->parent.desc,
2348 lttng_static_ctx, &event_notifier_priv->capture_bytecode_runtime_head,
2349 &event_notifier_enabler->capture_bytecode_head);
2350
2351 event_notifier_priv->num_captures = event_notifier_enabler->num_captures;
2352 }
2353 return 0;
2354 }
2355
2356 /*
2357 * Called at module load: connect the probe on all enablers matching
2358 * this event.
2359 * Called with sessions lock held.
2360 */
2361 int lttng_fix_pending_events(void)
2362 {
2363 struct lttng_session *session;
2364
2365 list_for_each_entry(session, &sessions, list)
2366 lttng_session_lazy_sync_event_enablers(session);
2367 return 0;
2368 }
2369
2370 static bool lttng_event_notifier_group_has_active_event_notifiers(
2371 struct lttng_event_notifier_group *event_notifier_group)
2372 {
2373 struct lttng_event_notifier_enabler *event_notifier_enabler;
2374
2375 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head,
2376 node) {
2377 if (event_notifier_enabler->base.enabled)
2378 return true;
2379 }
2380 return false;
2381 }
2382
2383 bool lttng_event_notifier_active(void)
2384 {
2385 struct lttng_event_notifier_group *event_notifier_group;
2386
2387 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2388 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2389 return true;
2390 }
2391 return false;
2392 }
2393
2394 int lttng_fix_pending_event_notifiers(void)
2395 {
2396 struct lttng_event_notifier_group *event_notifier_group;
2397
2398 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2399 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2400 return 0;
2401 }
2402
2403 struct lttng_event_enabler *lttng_event_enabler_create(
2404 enum lttng_enabler_format_type format_type,
2405 struct lttng_kernel_abi_event *event_param,
2406 struct lttng_channel *chan)
2407 {
2408 struct lttng_event_enabler *event_enabler;
2409
2410 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2411 if (!event_enabler)
2412 return NULL;
2413 event_enabler->base.format_type = format_type;
2414 INIT_LIST_HEAD(&event_enabler->base.filter_bytecode_head);
2415 memcpy(&event_enabler->base.event_param, event_param,
2416 sizeof(event_enabler->base.event_param));
2417 event_enabler->chan = chan;
2418 /* ctx left NULL */
2419 event_enabler->base.enabled = 0;
2420 mutex_lock(&sessions_mutex);
2421 list_add(&event_enabler->node, &event_enabler->chan->session->enablers_head);
2422 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2423 mutex_unlock(&sessions_mutex);
2424 return event_enabler;
2425 }
2426
2427 int lttng_event_enabler_enable(struct lttng_event_enabler *event_enabler)
2428 {
2429 mutex_lock(&sessions_mutex);
2430 lttng_event_enabler_as_enabler(event_enabler)->enabled = 1;
2431 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2432 mutex_unlock(&sessions_mutex);
2433 return 0;
2434 }
2435
2436 int lttng_event_enabler_disable(struct lttng_event_enabler *event_enabler)
2437 {
2438 mutex_lock(&sessions_mutex);
2439 lttng_event_enabler_as_enabler(event_enabler)->enabled = 0;
2440 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2441 mutex_unlock(&sessions_mutex);
2442 return 0;
2443 }
2444
2445 static
2446 int lttng_enabler_attach_filter_bytecode(struct lttng_enabler *enabler,
2447 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2448 {
2449 struct lttng_bytecode_node *bytecode_node;
2450 uint32_t bytecode_len;
2451 int ret;
2452
2453 ret = get_user(bytecode_len, &bytecode->len);
2454 if (ret)
2455 return ret;
2456 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2457 GFP_KERNEL);
2458 if (!bytecode_node)
2459 return -ENOMEM;
2460 ret = copy_from_user(&bytecode_node->bc, bytecode,
2461 sizeof(*bytecode) + bytecode_len);
2462 if (ret)
2463 goto error_free;
2464
2465 bytecode_node->type = LTTNG_BYTECODE_NODE_TYPE_FILTER;
2466 bytecode_node->enabler = enabler;
2467 /* Enforce length based on allocated size */
2468 bytecode_node->bc.len = bytecode_len;
2469 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2470
2471 return 0;
2472
2473 error_free:
2474 lttng_kvfree(bytecode_node);
2475 return ret;
2476 }
2477
2478 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler *event_enabler,
2479 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2480 {
2481 int ret;
2482 ret = lttng_enabler_attach_filter_bytecode(
2483 lttng_event_enabler_as_enabler(event_enabler), bytecode);
2484 if (ret)
2485 goto error;
2486
2487 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2488 return 0;
2489
2490 error:
2491 return ret;
2492 }
2493
2494 int lttng_event_add_callsite(struct lttng_kernel_event_common *event,
2495 struct lttng_kernel_abi_event_callsite __user *callsite)
2496 {
2497
2498 switch (event->priv->instrumentation) {
2499 case LTTNG_KERNEL_ABI_UPROBE:
2500 return lttng_uprobes_event_add_callsite(event, callsite);
2501 default:
2502 return -EINVAL;
2503 }
2504 }
2505
2506 static
2507 void lttng_enabler_destroy(struct lttng_enabler *enabler)
2508 {
2509 struct lttng_bytecode_node *filter_node, *tmp_filter_node;
2510
2511 /* Destroy filter bytecode */
2512 list_for_each_entry_safe(filter_node, tmp_filter_node,
2513 &enabler->filter_bytecode_head, node) {
2514 lttng_kvfree(filter_node);
2515 }
2516 }
2517
2518 static
2519 void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler)
2520 {
2521 lttng_enabler_destroy(lttng_event_enabler_as_enabler(event_enabler));
2522
2523 list_del(&event_enabler->node);
2524 kfree(event_enabler);
2525 }
2526
2527 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2528 struct lttng_event_notifier_group *event_notifier_group,
2529 enum lttng_enabler_format_type format_type,
2530 struct lttng_kernel_abi_event_notifier *event_notifier_param)
2531 {
2532 struct lttng_event_notifier_enabler *event_notifier_enabler;
2533
2534 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2535 if (!event_notifier_enabler)
2536 return NULL;
2537
2538 event_notifier_enabler->base.format_type = format_type;
2539 INIT_LIST_HEAD(&event_notifier_enabler->base.filter_bytecode_head);
2540 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2541
2542 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2543 event_notifier_enabler->num_captures = 0;
2544
2545 memcpy(&event_notifier_enabler->base.event_param, &event_notifier_param->event,
2546 sizeof(event_notifier_enabler->base.event_param));
2547
2548 event_notifier_enabler->base.enabled = 0;
2549 event_notifier_enabler->base.user_token = event_notifier_param->event.token;
2550 event_notifier_enabler->group = event_notifier_group;
2551
2552 mutex_lock(&sessions_mutex);
2553 list_add(&event_notifier_enabler->node, &event_notifier_enabler->group->enablers_head);
2554 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2555
2556 mutex_unlock(&sessions_mutex);
2557
2558 return event_notifier_enabler;
2559 }
2560
2561 int lttng_event_notifier_enabler_enable(
2562 struct lttng_event_notifier_enabler *event_notifier_enabler)
2563 {
2564 mutex_lock(&sessions_mutex);
2565 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2566 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2567 mutex_unlock(&sessions_mutex);
2568 return 0;
2569 }
2570
2571 int lttng_event_notifier_enabler_disable(
2572 struct lttng_event_notifier_enabler *event_notifier_enabler)
2573 {
2574 mutex_lock(&sessions_mutex);
2575 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2576 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2577 mutex_unlock(&sessions_mutex);
2578 return 0;
2579 }
2580
2581 int lttng_event_notifier_enabler_attach_filter_bytecode(
2582 struct lttng_event_notifier_enabler *event_notifier_enabler,
2583 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2584 {
2585 int ret;
2586
2587 ret = lttng_enabler_attach_filter_bytecode(
2588 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler),
2589 bytecode);
2590 if (ret)
2591 goto error;
2592
2593 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2594 return 0;
2595
2596 error:
2597 return ret;
2598 }
2599
2600 int lttng_event_notifier_enabler_attach_capture_bytecode(
2601 struct lttng_event_notifier_enabler *event_notifier_enabler,
2602 struct lttng_kernel_abi_capture_bytecode __user *bytecode)
2603 {
2604 struct lttng_bytecode_node *bytecode_node;
2605 struct lttng_enabler *enabler =
2606 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2607 uint32_t bytecode_len;
2608 int ret;
2609
2610 ret = get_user(bytecode_len, &bytecode->len);
2611 if (ret)
2612 return ret;
2613
2614 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2615 GFP_KERNEL);
2616 if (!bytecode_node)
2617 return -ENOMEM;
2618
2619 ret = copy_from_user(&bytecode_node->bc, bytecode,
2620 sizeof(*bytecode) + bytecode_len);
2621 if (ret)
2622 goto error_free;
2623
2624 bytecode_node->type = LTTNG_BYTECODE_NODE_TYPE_CAPTURE;
2625 bytecode_node->enabler = enabler;
2626
2627 /* Enforce length based on allocated size */
2628 bytecode_node->bc.len = bytecode_len;
2629 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2630
2631 event_notifier_enabler->num_captures++;
2632
2633 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2634 goto end;
2635
2636 error_free:
2637 lttng_kvfree(bytecode_node);
2638 end:
2639 return ret;
2640 }
2641
2642 static
2643 void lttng_event_notifier_enabler_destroy(
2644 struct lttng_event_notifier_enabler *event_notifier_enabler)
2645 {
2646 if (!event_notifier_enabler) {
2647 return;
2648 }
2649
2650 list_del(&event_notifier_enabler->node);
2651
2652 lttng_enabler_destroy(lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2653 kfree(event_notifier_enabler);
2654 }
2655
2656 /*
2657 * lttng_session_sync_event_enablers should be called just before starting a
2658 * session.
2659 * Should be called with sessions mutex held.
2660 */
2661 static
2662 void lttng_session_sync_event_enablers(struct lttng_session *session)
2663 {
2664 struct lttng_event_enabler *event_enabler;
2665 struct lttng_kernel_event_recorder_private *event_recorder_priv;
2666
2667 list_for_each_entry(event_enabler, &session->enablers_head, node)
2668 lttng_event_enabler_ref_events(event_enabler);
2669 /*
2670 * For each event, if at least one of its enablers is enabled,
2671 * and its channel and session transient states are enabled, we
2672 * enable the event, else we disable it.
2673 */
2674 list_for_each_entry(event_recorder_priv, &session->events, node) {
2675 struct lttng_kernel_event_recorder *event_recorder = event_recorder_priv->pub;
2676 struct lttng_enabler_ref *enabler_ref;
2677 struct lttng_bytecode_runtime *runtime;
2678 int enabled = 0, has_enablers_without_filter_bytecode = 0;
2679 int nr_filters = 0;
2680
2681 switch (event_recorder_priv->parent.instrumentation) {
2682 case LTTNG_KERNEL_ABI_TRACEPOINT: /* Fall-through */
2683 case LTTNG_KERNEL_ABI_SYSCALL:
2684 /* Enable events */
2685 list_for_each_entry(enabler_ref,
2686 &event_recorder_priv->parent.enablers_ref_head, node) {
2687 if (enabler_ref->ref->enabled) {
2688 enabled = 1;
2689 break;
2690 }
2691 }
2692 break;
2693
2694 default:
2695 /* Not handled with lazy sync. */
2696 continue;
2697 }
2698 /*
2699 * Enabled state is based on union of enablers, with
2700 * intesection of session and channel transient enable
2701 * states.
2702 */
2703 enabled = enabled && session->tstate && event_recorder->chan->tstate;
2704
2705 WRITE_ONCE(event_recorder->parent.enabled, enabled);
2706 /*
2707 * Sync tracepoint registration with event enabled
2708 * state.
2709 */
2710 if (enabled) {
2711 register_event(event_recorder);
2712 } else {
2713 _lttng_event_unregister(event_recorder);
2714 }
2715
2716 /* Check if has enablers without bytecode enabled */
2717 list_for_each_entry(enabler_ref,
2718 &event_recorder_priv->parent.enablers_ref_head, node) {
2719 if (enabler_ref->ref->enabled
2720 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2721 has_enablers_without_filter_bytecode = 1;
2722 break;
2723 }
2724 }
2725 event_recorder_priv->parent.has_enablers_without_filter_bytecode =
2726 has_enablers_without_filter_bytecode;
2727
2728 /* Enable filters */
2729 list_for_each_entry(runtime,
2730 &event_recorder_priv->parent.filter_bytecode_runtime_head, node) {
2731 lttng_bytecode_filter_sync_state(runtime);
2732 nr_filters++;
2733 }
2734 WRITE_ONCE(event_recorder_priv->parent.pub->eval_filter,
2735 !(has_enablers_without_filter_bytecode || !nr_filters));
2736 }
2737 }
2738
2739 /*
2740 * Apply enablers to session events, adding events to session if need
2741 * be. It is required after each modification applied to an active
2742 * session, and right before session "start".
2743 * "lazy" sync means we only sync if required.
2744 * Should be called with sessions mutex held.
2745 */
2746 static
2747 void lttng_session_lazy_sync_event_enablers(struct lttng_session *session)
2748 {
2749 /* We can skip if session is not active */
2750 if (!session->active)
2751 return;
2752 lttng_session_sync_event_enablers(session);
2753 }
2754
2755 static
2756 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2757 {
2758 struct lttng_event_notifier_enabler *event_notifier_enabler;
2759 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2760
2761 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head, node)
2762 lttng_event_notifier_enabler_ref_event_notifiers(event_notifier_enabler);
2763
2764 /*
2765 * For each event_notifier, if at least one of its enablers is enabled,
2766 * we enable the event_notifier, else we disable it.
2767 */
2768 list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, node) {
2769 struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
2770 struct lttng_enabler_ref *enabler_ref;
2771 struct lttng_bytecode_runtime *runtime;
2772 int enabled = 0, has_enablers_without_filter_bytecode = 0;
2773 int nr_filters = 0, nr_captures = 0;
2774
2775 switch (event_notifier_priv->parent.instrumentation) {
2776 case LTTNG_KERNEL_ABI_TRACEPOINT: /* Fall-through */
2777 case LTTNG_KERNEL_ABI_SYSCALL:
2778 /* Enable event_notifiers */
2779 list_for_each_entry(enabler_ref,
2780 &event_notifier_priv->parent.enablers_ref_head, node) {
2781 if (enabler_ref->ref->enabled) {
2782 enabled = 1;
2783 break;
2784 }
2785 }
2786 break;
2787
2788 default:
2789 /* Not handled with sync. */
2790 continue;
2791 }
2792
2793 WRITE_ONCE(event_notifier->parent.enabled, enabled);
2794 /*
2795 * Sync tracepoint registration with event_notifier enabled
2796 * state.
2797 */
2798 if (enabled) {
2799 if (!event_notifier_priv->parent.registered)
2800 register_event_notifier(event_notifier);
2801 } else {
2802 if (event_notifier_priv->parent.registered)
2803 _lttng_event_notifier_unregister(event_notifier);
2804 }
2805
2806 /* Check if has enablers without bytecode enabled */
2807 list_for_each_entry(enabler_ref,
2808 &event_notifier_priv->parent.enablers_ref_head, node) {
2809 if (enabler_ref->ref->enabled
2810 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2811 has_enablers_without_filter_bytecode = 1;
2812 break;
2813 }
2814 }
2815 event_notifier_priv->parent.has_enablers_without_filter_bytecode =
2816 has_enablers_without_filter_bytecode;
2817
2818 /* Enable filters */
2819 list_for_each_entry(runtime,
2820 &event_notifier_priv->parent.filter_bytecode_runtime_head, node) {
2821 lttng_bytecode_filter_sync_state(runtime);
2822 nr_filters++;
2823 }
2824 WRITE_ONCE(event_notifier_priv->parent.pub->eval_filter,
2825 !(has_enablers_without_filter_bytecode || !nr_filters));
2826
2827 /* Enable captures */
2828 list_for_each_entry(runtime,
2829 &event_notifier_priv->capture_bytecode_runtime_head, node) {
2830 lttng_bytecode_capture_sync_state(runtime);
2831 nr_captures++;
2832 }
2833 WRITE_ONCE(event_notifier->eval_capture, !!nr_captures);
2834 }
2835 }
2836
2837 /*
2838 * Serialize at most one packet worth of metadata into a metadata
2839 * channel.
2840 * We grab the metadata cache mutex to get exclusive access to our metadata
2841 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2842 * allows us to do racy operations such as looking for remaining space left in
2843 * packet and write, since mutual exclusion protects us from concurrent writes.
2844 * Mutual exclusion on the metadata cache allow us to read the cache content
2845 * without racing against reallocation of the cache by updates.
2846 * Returns the number of bytes written in the channel, 0 if no data
2847 * was written and a negative value on error.
2848 */
2849 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2850 struct channel *chan, bool *coherent)
2851 {
2852 struct lib_ring_buffer_ctx ctx;
2853 int ret = 0;
2854 size_t len, reserve_len;
2855
2856 /*
2857 * Ensure we support mutiple get_next / put sequences followed by
2858 * put_next. The metadata cache lock protects reading the metadata
2859 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2860 * "flush" operations on the buffer invoked by different processes.
2861 * Moreover, since the metadata cache memory can be reallocated, we
2862 * need to have exclusive access against updates even though we only
2863 * read it.
2864 */
2865 mutex_lock(&stream->metadata_cache->lock);
2866 WARN_ON(stream->metadata_in < stream->metadata_out);
2867 if (stream->metadata_in != stream->metadata_out)
2868 goto end;
2869
2870 /* Metadata regenerated, change the version. */
2871 if (stream->metadata_cache->version != stream->version)
2872 stream->version = stream->metadata_cache->version;
2873
2874 len = stream->metadata_cache->metadata_written -
2875 stream->metadata_in;
2876 if (!len)
2877 goto end;
2878 reserve_len = min_t(size_t,
2879 stream->transport->ops.packet_avail_size(chan),
2880 len);
2881 lib_ring_buffer_ctx_init(&ctx, chan, NULL, reserve_len,
2882 sizeof(char), -1);
2883 /*
2884 * If reservation failed, return an error to the caller.
2885 */
2886 ret = stream->transport->ops.event_reserve(&ctx, 0);
2887 if (ret != 0) {
2888 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2889 stream->coherent = false;
2890 goto end;
2891 }
2892 stream->transport->ops.event_write(&ctx,
2893 stream->metadata_cache->data + stream->metadata_in,
2894 reserve_len);
2895 stream->transport->ops.event_commit(&ctx);
2896 stream->metadata_in += reserve_len;
2897 if (reserve_len < len)
2898 stream->coherent = false;
2899 else
2900 stream->coherent = true;
2901 ret = reserve_len;
2902
2903 end:
2904 if (coherent)
2905 *coherent = stream->coherent;
2906 mutex_unlock(&stream->metadata_cache->lock);
2907 return ret;
2908 }
2909
2910 static
2911 void lttng_metadata_begin(struct lttng_session *session)
2912 {
2913 if (atomic_inc_return(&session->metadata_cache->producing) == 1)
2914 mutex_lock(&session->metadata_cache->lock);
2915 }
2916
2917 static
2918 void lttng_metadata_end(struct lttng_session *session)
2919 {
2920 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
2921 if (atomic_dec_return(&session->metadata_cache->producing) == 0) {
2922 struct lttng_metadata_stream *stream;
2923
2924 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
2925 wake_up_interruptible(&stream->read_wait);
2926 mutex_unlock(&session->metadata_cache->lock);
2927 }
2928 }
2929
2930 /*
2931 * Write the metadata to the metadata cache.
2932 * Must be called with sessions_mutex held.
2933 * The metadata cache lock protects us from concurrent read access from
2934 * thread outputting metadata content to ring buffer.
2935 * The content of the printf is printed as a single atomic metadata
2936 * transaction.
2937 */
2938 int lttng_metadata_printf(struct lttng_session *session,
2939 const char *fmt, ...)
2940 {
2941 char *str;
2942 size_t len;
2943 va_list ap;
2944
2945 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
2946
2947 va_start(ap, fmt);
2948 str = kvasprintf(GFP_KERNEL, fmt, ap);
2949 va_end(ap);
2950 if (!str)
2951 return -ENOMEM;
2952
2953 len = strlen(str);
2954 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
2955 if (session->metadata_cache->metadata_written + len >
2956 session->metadata_cache->cache_alloc) {
2957 char *tmp_cache_realloc;
2958 unsigned int tmp_cache_alloc_size;
2959
2960 tmp_cache_alloc_size = max_t(unsigned int,
2961 session->metadata_cache->cache_alloc + len,
2962 session->metadata_cache->cache_alloc << 1);
2963 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
2964 if (!tmp_cache_realloc)
2965 goto err;
2966 if (session->metadata_cache->data) {
2967 memcpy(tmp_cache_realloc,
2968 session->metadata_cache->data,
2969 session->metadata_cache->cache_alloc);
2970 vfree(session->metadata_cache->data);
2971 }
2972
2973 session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
2974 session->metadata_cache->data = tmp_cache_realloc;
2975 }
2976 memcpy(session->metadata_cache->data +
2977 session->metadata_cache->metadata_written,
2978 str, len);
2979 session->metadata_cache->metadata_written += len;
2980 kfree(str);
2981
2982 return 0;
2983
2984 err:
2985 kfree(str);
2986 return -ENOMEM;
2987 }
2988
2989 static
2990 int print_tabs(struct lttng_session *session, size_t nesting)
2991 {
2992 size_t i;
2993
2994 for (i = 0; i < nesting; i++) {
2995 int ret;
2996
2997 ret = lttng_metadata_printf(session, " ");
2998 if (ret) {
2999 return ret;
3000 }
3001 }
3002 return 0;
3003 }
3004
3005 static
3006 int lttng_field_name_statedump(struct lttng_session *session,
3007 const struct lttng_kernel_event_field *field,
3008 size_t nesting)
3009 {
3010 return lttng_metadata_printf(session, " _%s;\n", field->name);
3011 }
3012
3013 static
3014 int _lttng_integer_type_statedump(struct lttng_session *session,
3015 const struct lttng_kernel_type_integer *type,
3016 enum lttng_kernel_string_encoding parent_encoding,
3017 size_t nesting)
3018 {
3019 int ret;
3020
3021 ret = print_tabs(session, nesting);
3022 if (ret)
3023 return ret;
3024 ret = lttng_metadata_printf(session,
3025 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
3026 type->size,
3027 type->alignment,
3028 type->signedness,
3029 (parent_encoding == lttng_kernel_string_encoding_none)
3030 ? "none"
3031 : (parent_encoding == lttng_kernel_string_encoding_UTF8)
3032 ? "UTF8"
3033 : "ASCII",
3034 type->base,
3035 #if __BYTE_ORDER == __BIG_ENDIAN
3036 type->reverse_byte_order ? " byte_order = le;" : ""
3037 #else
3038 type->reverse_byte_order ? " byte_order = be;" : ""
3039 #endif
3040 );
3041 return ret;
3042 }
3043
3044 /*
3045 * Must be called with sessions_mutex held.
3046 */
3047 static
3048 int _lttng_struct_type_statedump(struct lttng_session *session,
3049 const struct lttng_kernel_type_struct *type,
3050 size_t nesting)
3051 {
3052 int ret;
3053 uint32_t i, nr_fields;
3054 unsigned int alignment;
3055
3056 ret = print_tabs(session, nesting);
3057 if (ret)
3058 return ret;
3059 ret = lttng_metadata_printf(session,
3060 "struct {\n");
3061 if (ret)
3062 return ret;
3063 nr_fields = type->nr_fields;
3064 for (i = 0; i < nr_fields; i++) {
3065 const struct lttng_kernel_event_field *iter_field;
3066
3067 iter_field = type->fields[i];
3068 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
3069 if (ret)
3070 return ret;
3071 }
3072 ret = print_tabs(session, nesting);
3073 if (ret)
3074 return ret;
3075 alignment = type->alignment;
3076 if (alignment) {
3077 ret = lttng_metadata_printf(session,
3078 "} align(%u)",
3079 alignment);
3080 } else {
3081 ret = lttng_metadata_printf(session,
3082 "}");
3083 }
3084 return ret;
3085 }
3086
3087 /*
3088 * Must be called with sessions_mutex held.
3089 */
3090 static
3091 int _lttng_struct_field_statedump(struct lttng_session *session,
3092 const struct lttng_kernel_event_field *field,
3093 size_t nesting)
3094 {
3095 int ret;
3096
3097 ret = _lttng_struct_type_statedump(session,
3098 lttng_kernel_get_type_struct(field->type), nesting);
3099 if (ret)
3100 return ret;
3101 return lttng_field_name_statedump(session, field, nesting);
3102 }
3103
3104 /*
3105 * Must be called with sessions_mutex held.
3106 */
3107 static
3108 int _lttng_variant_type_statedump(struct lttng_session *session,
3109 const struct lttng_kernel_type_variant *type,
3110 size_t nesting)
3111 {
3112 int ret;
3113 uint32_t i, nr_choices;
3114
3115 /*
3116 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3117 */
3118 if (type->alignment != 0)
3119 return -EINVAL;
3120 ret = print_tabs(session, nesting);
3121 if (ret)
3122 return ret;
3123 ret = lttng_metadata_printf(session,
3124 "variant <_%s> {\n",
3125 type->tag_name);
3126 if (ret)
3127 return ret;
3128 nr_choices = type->nr_choices;
3129 for (i = 0; i < nr_choices; i++) {
3130 const struct lttng_kernel_event_field *iter_field;
3131
3132 iter_field = type->choices[i];
3133 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
3134 if (ret)
3135 return ret;
3136 }
3137 ret = print_tabs(session, nesting);
3138 if (ret)
3139 return ret;
3140 ret = lttng_metadata_printf(session,
3141 "}");
3142 return ret;
3143 }
3144
3145 /*
3146 * Must be called with sessions_mutex held.
3147 */
3148 static
3149 int _lttng_variant_field_statedump(struct lttng_session *session,
3150 const struct lttng_kernel_event_field *field,
3151 size_t nesting)
3152 {
3153 int ret;
3154
3155 ret = _lttng_variant_type_statedump(session,
3156 lttng_kernel_get_type_variant(field->type), nesting);
3157 if (ret)
3158 return ret;
3159 return lttng_field_name_statedump(session, field, nesting);
3160 }
3161
3162 /*
3163 * Must be called with sessions_mutex held.
3164 */
3165 static
3166 int _lttng_array_field_statedump(struct lttng_session *session,
3167 const struct lttng_kernel_event_field *field,
3168 size_t nesting)
3169 {
3170 int ret;
3171 const struct lttng_kernel_type_array *array_type;
3172 const struct lttng_kernel_type_common *elem_type;
3173
3174 array_type = lttng_kernel_get_type_array(field->type);
3175 WARN_ON_ONCE(!array_type);
3176
3177 if (array_type->alignment) {
3178 ret = print_tabs(session, nesting);
3179 if (ret)
3180 return ret;
3181 ret = lttng_metadata_printf(session,
3182 "struct { } align(%u) _%s_padding;\n",
3183 array_type->alignment * CHAR_BIT,
3184 field->name);
3185 if (ret)
3186 return ret;
3187 }
3188 /*
3189 * Nested compound types: Only array of structures and variants are
3190 * currently supported.
3191 */
3192 elem_type = array_type->elem_type;
3193 switch (elem_type->type) {
3194 case lttng_kernel_type_integer:
3195 case lttng_kernel_type_struct:
3196 case lttng_kernel_type_variant:
3197 ret = _lttng_type_statedump(session, elem_type,
3198 array_type->encoding, nesting);
3199 if (ret)
3200 return ret;
3201 break;
3202
3203 default:
3204 return -EINVAL;
3205 }
3206 ret = lttng_metadata_printf(session,
3207 " _%s[%u];\n",
3208 field->name,
3209 array_type->length);
3210 return ret;
3211 }
3212
3213 /*
3214 * Must be called with sessions_mutex held.
3215 */
3216 static
3217 int _lttng_sequence_field_statedump(struct lttng_session *session,
3218 const struct lttng_kernel_event_field *field,
3219 size_t nesting)
3220 {
3221 int ret;
3222 const char *length_name;
3223 const struct lttng_kernel_type_sequence *sequence_type;
3224 const struct lttng_kernel_type_common *elem_type;
3225
3226 sequence_type = lttng_kernel_get_type_sequence(field->type);
3227 WARN_ON_ONCE(!sequence_type);
3228
3229 length_name = sequence_type->length_name;
3230
3231 if (sequence_type->alignment) {
3232 ret = print_tabs(session, nesting);
3233 if (ret)
3234 return ret;
3235 ret = lttng_metadata_printf(session,
3236 "struct { } align(%u) _%s_padding;\n",
3237 sequence_type->alignment * CHAR_BIT,
3238 field->name);
3239 if (ret)
3240 return ret;
3241 }
3242
3243 /*
3244 * Nested compound types: Only array of structures and variants are
3245 * currently supported.
3246 */
3247 elem_type = sequence_type->elem_type;
3248 switch (elem_type->type) {
3249 case lttng_kernel_type_integer:
3250 case lttng_kernel_type_struct:
3251 case lttng_kernel_type_variant:
3252 ret = _lttng_type_statedump(session, elem_type,
3253 sequence_type->encoding, nesting);
3254 if (ret)
3255 return ret;
3256 break;
3257
3258 default:
3259 return -EINVAL;
3260 }
3261 ret = lttng_metadata_printf(session,
3262 " _%s[ _%s ];\n",
3263 field->name,
3264 sequence_type->length_name);
3265 return ret;
3266 }
3267
3268 /*
3269 * Must be called with sessions_mutex held.
3270 */
3271 static
3272 int _lttng_enum_type_statedump(struct lttng_session *session,
3273 const struct lttng_kernel_type_enum *type,
3274 size_t nesting)
3275 {
3276 const struct lttng_kernel_enum_desc *enum_desc;
3277 const struct lttng_kernel_type_common *container_type;
3278 int ret;
3279 unsigned int i, nr_entries;
3280
3281 container_type = type->container_type;
3282 if (container_type->type != lttng_kernel_type_integer) {
3283 ret = -EINVAL;
3284 goto end;
3285 }
3286 enum_desc = type->desc;
3287 nr_entries = enum_desc->nr_entries;
3288
3289 ret = print_tabs(session, nesting);
3290 if (ret)
3291 goto end;
3292 ret = lttng_metadata_printf(session, "enum : ");
3293 if (ret)
3294 goto end;
3295 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(container_type),
3296 lttng_kernel_string_encoding_none, 0);
3297 if (ret)
3298 goto end;
3299 ret = lttng_metadata_printf(session, " {\n");
3300 if (ret)
3301 goto end;
3302 /* Dump all entries */
3303 for (i = 0; i < nr_entries; i++) {
3304 const struct lttng_kernel_enum_entry *entry = enum_desc->entries[i];
3305 int j, len;
3306
3307 ret = print_tabs(session, nesting + 1);
3308 if (ret)
3309 goto end;
3310 ret = lttng_metadata_printf(session,
3311 "\"");
3312 if (ret)
3313 goto end;
3314 len = strlen(entry->string);
3315 /* Escape the character '"' */
3316 for (j = 0; j < len; j++) {
3317 char c = entry->string[j];
3318
3319 switch (c) {
3320 case '"':
3321 ret = lttng_metadata_printf(session,
3322 "\\\"");
3323 break;
3324 case '\\':
3325 ret = lttng_metadata_printf(session,
3326 "\\\\");
3327 break;
3328 default:
3329 ret = lttng_metadata_printf(session,
3330 "%c", c);
3331 break;
3332 }
3333 if (ret)
3334 goto end;
3335 }
3336 ret = lttng_metadata_printf(session, "\"");
3337 if (ret)
3338 goto end;
3339
3340 if (entry->options.is_auto) {
3341 ret = lttng_metadata_printf(session, ",\n");
3342 if (ret)
3343 goto end;
3344 } else {
3345 ret = lttng_metadata_printf(session,
3346 " = ");
3347 if (ret)
3348 goto end;
3349 if (entry->start.signedness)
3350 ret = lttng_metadata_printf(session,
3351 "%lld", (long long) entry->start.value);
3352 else
3353 ret = lttng_metadata_printf(session,
3354 "%llu", entry->start.value);
3355 if (ret)
3356 goto end;
3357 if (entry->start.signedness == entry->end.signedness &&
3358 entry->start.value
3359 == entry->end.value) {
3360 ret = lttng_metadata_printf(session,
3361 ",\n");
3362 } else {
3363 if (entry->end.signedness) {
3364 ret = lttng_metadata_printf(session,
3365 " ... %lld,\n",
3366 (long long) entry->end.value);
3367 } else {
3368 ret = lttng_metadata_printf(session,
3369 " ... %llu,\n",
3370 entry->end.value);
3371 }
3372 }
3373 if (ret)
3374 goto end;
3375 }
3376 }
3377 ret = print_tabs(session, nesting);
3378 if (ret)
3379 goto end;
3380 ret = lttng_metadata_printf(session, "}");
3381 end:
3382 return ret;
3383 }
3384
3385 /*
3386 * Must be called with sessions_mutex held.
3387 */
3388 static
3389 int _lttng_enum_field_statedump(struct lttng_session *session,
3390 const struct lttng_kernel_event_field *field,
3391 size_t nesting)
3392 {
3393 int ret;
3394 const struct lttng_kernel_type_enum *enum_type;
3395
3396 enum_type = lttng_kernel_get_type_enum(field->type);
3397 WARN_ON_ONCE(!enum_type);
3398 ret = _lttng_enum_type_statedump(session, enum_type, nesting);
3399 if (ret)
3400 return ret;
3401 return lttng_field_name_statedump(session, field, nesting);
3402 }
3403
3404 static
3405 int _lttng_integer_field_statedump(struct lttng_session *session,
3406 const struct lttng_kernel_event_field *field,
3407 size_t nesting)
3408 {
3409 int ret;
3410
3411 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(field->type),
3412 lttng_kernel_string_encoding_none, nesting);
3413 if (ret)
3414 return ret;
3415 return lttng_field_name_statedump(session, field, nesting);
3416 }
3417
3418 static
3419 int _lttng_string_type_statedump(struct lttng_session *session,
3420 const struct lttng_kernel_type_string *type,
3421 size_t nesting)
3422 {
3423 int ret;
3424
3425 /* Default encoding is UTF8 */
3426 ret = print_tabs(session, nesting);
3427 if (ret)
3428 return ret;
3429 ret = lttng_metadata_printf(session,
3430 "string%s",
3431 type->encoding == lttng_kernel_string_encoding_ASCII ?
3432 " { encoding = ASCII; }" : "");
3433 return ret;
3434 }
3435
3436 static
3437 int _lttng_string_field_statedump(struct lttng_session *session,
3438 const struct lttng_kernel_event_field *field,
3439 size_t nesting)
3440 {
3441 const struct lttng_kernel_type_string *string_type;
3442 int ret;
3443
3444 string_type = lttng_kernel_get_type_string(field->type);
3445 WARN_ON_ONCE(!string_type);
3446 ret = _lttng_string_type_statedump(session, string_type, nesting);
3447 if (ret)
3448 return ret;
3449 return lttng_field_name_statedump(session, field, nesting);
3450 }
3451
3452 /*
3453 * Must be called with sessions_mutex held.
3454 */
3455 static
3456 int _lttng_type_statedump(struct lttng_session *session,
3457 const struct lttng_kernel_type_common *type,
3458 enum lttng_kernel_string_encoding parent_encoding,
3459 size_t nesting)
3460 {
3461 int ret = 0;
3462
3463 switch (type->type) {
3464 case lttng_kernel_type_integer:
3465 ret = _lttng_integer_type_statedump(session,
3466 lttng_kernel_get_type_integer(type),
3467 parent_encoding, nesting);
3468 break;
3469 case lttng_kernel_type_enum:
3470 ret = _lttng_enum_type_statedump(session,
3471 lttng_kernel_get_type_enum(type),
3472 nesting);
3473 break;
3474 case lttng_kernel_type_string:
3475 ret = _lttng_string_type_statedump(session,
3476 lttng_kernel_get_type_string(type),
3477 nesting);
3478 break;
3479 case lttng_kernel_type_struct:
3480 ret = _lttng_struct_type_statedump(session,
3481 lttng_kernel_get_type_struct(type),
3482 nesting);
3483 break;
3484 case lttng_kernel_type_variant:
3485 ret = _lttng_variant_type_statedump(session,
3486 lttng_kernel_get_type_variant(type),
3487 nesting);
3488 break;
3489
3490 /* Nested arrays and sequences are not supported yet. */
3491 case lttng_kernel_type_array:
3492 case lttng_kernel_type_sequence:
3493 default:
3494 WARN_ON_ONCE(1);
3495 return -EINVAL;
3496 }
3497 return ret;
3498 }
3499
3500 /*
3501 * Must be called with sessions_mutex held.
3502 */
3503 static
3504 int _lttng_field_statedump(struct lttng_session *session,
3505 const struct lttng_kernel_event_field *field,
3506 size_t nesting)
3507 {
3508 int ret = 0;
3509
3510 switch (field->type->type) {
3511 case lttng_kernel_type_integer:
3512 ret = _lttng_integer_field_statedump(session, field, nesting);
3513 break;
3514 case lttng_kernel_type_enum:
3515 ret = _lttng_enum_field_statedump(session, field, nesting);
3516 break;
3517 case lttng_kernel_type_string:
3518 ret = _lttng_string_field_statedump(session, field, nesting);
3519 break;
3520 case lttng_kernel_type_struct:
3521 ret = _lttng_struct_field_statedump(session, field, nesting);
3522 break;
3523 case lttng_kernel_type_array:
3524 ret = _lttng_array_field_statedump(session, field, nesting);
3525 break;
3526 case lttng_kernel_type_sequence:
3527 ret = _lttng_sequence_field_statedump(session, field, nesting);
3528 break;
3529 case lttng_kernel_type_variant:
3530 ret = _lttng_variant_field_statedump(session, field, nesting);
3531 break;
3532
3533 default:
3534 WARN_ON_ONCE(1);
3535 return -EINVAL;
3536 }
3537 return ret;
3538 }
3539
3540 static
3541 int _lttng_context_metadata_statedump(struct lttng_session *session,
3542 struct lttng_kernel_ctx *ctx)
3543 {
3544 int ret = 0;
3545 int i;
3546
3547 if (!ctx)
3548 return 0;
3549 for (i = 0; i < ctx->nr_fields; i++) {
3550 const struct lttng_kernel_ctx_field *field = &ctx->fields[i];
3551
3552 ret = _lttng_field_statedump(session, field->event_field, 2);
3553 if (ret)
3554 return ret;
3555 }
3556 return ret;
3557 }
3558
3559 static
3560 int _lttng_fields_metadata_statedump(struct lttng_session *session,
3561 struct lttng_kernel_event_recorder *event_recorder)
3562 {
3563 const struct lttng_kernel_event_desc *desc = event_recorder->priv->parent.desc;
3564 int ret = 0;
3565 int i;
3566
3567 for (i = 0; i < desc->nr_fields; i++) {
3568 const struct lttng_kernel_event_field *field = desc->fields[i];
3569
3570 ret = _lttng_field_statedump(session, field, 2);
3571 if (ret)
3572 return ret;
3573 }
3574 return ret;
3575 }
3576
3577 /*
3578 * Must be called with sessions_mutex held.
3579 * The entire event metadata is printed as a single atomic metadata
3580 * transaction.
3581 */
3582 static
3583 int _lttng_event_metadata_statedump(struct lttng_session *session,
3584 struct lttng_channel *chan,
3585 struct lttng_kernel_event_recorder *event_recorder)
3586 {
3587 int ret = 0;
3588
3589 if (event_recorder->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3590 return 0;
3591 if (chan->channel_type == METADATA_CHANNEL)
3592 return 0;
3593
3594 lttng_metadata_begin(session);
3595
3596 ret = lttng_metadata_printf(session,
3597 "event {\n"
3598 " name = \"%s\";\n"
3599 " id = %u;\n"
3600 " stream_id = %u;\n",
3601 event_recorder->priv->parent.desc->event_name,
3602 event_recorder->priv->id,
3603 event_recorder->chan->id);
3604 if (ret)
3605 goto end;
3606
3607 ret = lttng_metadata_printf(session,
3608 " fields := struct {\n"
3609 );
3610 if (ret)
3611 goto end;
3612
3613 ret = _lttng_fields_metadata_statedump(session, event_recorder);
3614 if (ret)
3615 goto end;
3616
3617 /*
3618 * LTTng space reservation can only reserve multiples of the
3619 * byte size.
3620 */
3621 ret = lttng_metadata_printf(session,
3622 " };\n"
3623 "};\n\n");
3624 if (ret)
3625 goto end;
3626
3627 event_recorder->priv->metadata_dumped = 1;
3628 end:
3629 lttng_metadata_end(session);
3630 return ret;
3631
3632 }
3633
3634 /*
3635 * Must be called with sessions_mutex held.
3636 * The entire channel metadata is printed as a single atomic metadata
3637 * transaction.
3638 */
3639 static
3640 int _lttng_channel_metadata_statedump(struct lttng_session *session,
3641 struct lttng_channel *chan)
3642 {
3643 int ret = 0;
3644
3645 if (chan->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3646 return 0;
3647
3648 if (chan->channel_type == METADATA_CHANNEL)
3649 return 0;
3650
3651 lttng_metadata_begin(session);
3652
3653 WARN_ON_ONCE(!chan->header_type);
3654 ret = lttng_metadata_printf(session,
3655 "stream {\n"
3656 " id = %u;\n"
3657 " event.header := %s;\n"
3658 " packet.context := struct packet_context;\n",
3659 chan->id,
3660 chan->header_type == 1 ? "struct event_header_compact" :
3661 "struct event_header_large");
3662 if (ret)
3663 goto end;
3664
3665 if (chan->ctx) {
3666 ret = lttng_metadata_printf(session,
3667 " event.context := struct {\n");
3668 if (ret)
3669 goto end;
3670 }
3671 ret = _lttng_context_metadata_statedump(session, chan->ctx);
3672 if (ret)
3673 goto end;
3674 if (chan->ctx) {
3675 ret = lttng_metadata_printf(session,
3676 " };\n");
3677 if (ret)
3678 goto end;
3679 }
3680
3681 ret = lttng_metadata_printf(session,
3682 "};\n\n");
3683
3684 chan->metadata_dumped = 1;
3685 end:
3686 lttng_metadata_end(session);
3687 return ret;
3688 }
3689
3690 /*
3691 * Must be called with sessions_mutex held.
3692 */
3693 static
3694 int _lttng_stream_packet_context_declare(struct lttng_session *session)
3695 {
3696 return lttng_metadata_printf(session,
3697 "struct packet_context {\n"
3698 " uint64_clock_monotonic_t timestamp_begin;\n"
3699 " uint64_clock_monotonic_t timestamp_end;\n"
3700 " uint64_t content_size;\n"
3701 " uint64_t packet_size;\n"
3702 " uint64_t packet_seq_num;\n"
3703 " unsigned long events_discarded;\n"
3704 " uint32_t cpu_id;\n"
3705 "};\n\n"
3706 );
3707 }
3708
3709 /*
3710 * Compact header:
3711 * id: range: 0 - 30.
3712 * id 31 is reserved to indicate an extended header.
3713 *
3714 * Large header:
3715 * id: range: 0 - 65534.
3716 * id 65535 is reserved to indicate an extended header.
3717 *
3718 * Must be called with sessions_mutex held.
3719 */
3720 static
3721 int _lttng_event_header_declare(struct lttng_session *session)
3722 {
3723 return lttng_metadata_printf(session,
3724 "struct event_header_compact {\n"
3725 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3726 " variant <id> {\n"
3727 " struct {\n"
3728 " uint27_clock_monotonic_t timestamp;\n"
3729 " } compact;\n"
3730 " struct {\n"
3731 " uint32_t id;\n"
3732 " uint64_clock_monotonic_t timestamp;\n"
3733 " } extended;\n"
3734 " } v;\n"
3735 "} align(%u);\n"
3736 "\n"
3737 "struct event_header_large {\n"
3738 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3739 " variant <id> {\n"
3740 " struct {\n"
3741 " uint32_clock_monotonic_t timestamp;\n"
3742 " } compact;\n"
3743 " struct {\n"
3744 " uint32_t id;\n"
3745 " uint64_clock_monotonic_t timestamp;\n"
3746 " } extended;\n"
3747 " } v;\n"
3748 "} align(%u);\n\n",
3749 lttng_alignof(uint32_t) * CHAR_BIT,
3750 lttng_alignof(uint16_t) * CHAR_BIT
3751 );
3752 }
3753
3754 /*
3755 * Approximation of NTP time of day to clock monotonic correlation,
3756 * taken at start of trace.
3757 * Yes, this is only an approximation. Yes, we can (and will) do better
3758 * in future versions.
3759 * This function may return a negative offset. It may happen if the
3760 * system sets the REALTIME clock to 0 after boot.
3761 *
3762 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3763 * y2038 compliant.
3764 */
3765 static
3766 int64_t measure_clock_offset(void)
3767 {
3768 uint64_t monotonic_avg, monotonic[2], realtime;
3769 uint64_t tcf = trace_clock_freq();
3770 int64_t offset;
3771 unsigned long flags;
3772 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3773 struct timespec64 rts = { 0, 0 };
3774 #else
3775 struct timespec rts = { 0, 0 };
3776 #endif
3777
3778 /* Disable interrupts to increase correlation precision. */
3779 local_irq_save(flags);
3780 monotonic[0] = trace_clock_read64();
3781 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3782 ktime_get_real_ts64(&rts);
3783 #else
3784 getnstimeofday(&rts);
3785 #endif
3786 monotonic[1] = trace_clock_read64();
3787 local_irq_restore(flags);
3788
3789 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3790 realtime = (uint64_t) rts.tv_sec * tcf;
3791 if (tcf == NSEC_PER_SEC) {
3792 realtime += rts.tv_nsec;
3793 } else {
3794 uint64_t n = rts.tv_nsec * tcf;
3795
3796 do_div(n, NSEC_PER_SEC);
3797 realtime += n;
3798 }
3799 offset = (int64_t) realtime - monotonic_avg;
3800 return offset;
3801 }
3802
3803 static
3804 int print_escaped_ctf_string(struct lttng_session *session, const char *string)
3805 {
3806 int ret = 0;
3807 size_t i;
3808 char cur;
3809
3810 i = 0;
3811 cur = string[i];
3812 while (cur != '\0') {
3813 switch (cur) {
3814 case '\n':
3815 ret = lttng_metadata_printf(session, "%s", "\\n");
3816 break;
3817 case '\\':
3818 case '"':
3819 ret = lttng_metadata_printf(session, "%c", '\\');
3820 if (ret)
3821 goto error;
3822 /* We still print the current char */
3823 /* Fallthrough */
3824 default:
3825 ret = lttng_metadata_printf(session, "%c", cur);
3826 break;
3827 }
3828
3829 if (ret)
3830 goto error;
3831
3832 cur = string[++i];
3833 }
3834 error:
3835 return ret;
3836 }
3837
3838 static
3839 int print_metadata_escaped_field(struct lttng_session *session, const char *field,
3840 const char *field_value)
3841 {
3842 int ret;
3843
3844 ret = lttng_metadata_printf(session, " %s = \"", field);
3845 if (ret)
3846 goto error;
3847
3848 ret = print_escaped_ctf_string(session, field_value);
3849 if (ret)
3850 goto error;
3851
3852 ret = lttng_metadata_printf(session, "\";\n");
3853
3854 error:
3855 return ret;
3856 }
3857
3858 /*
3859 * Output metadata into this session's metadata buffers.
3860 * Must be called with sessions_mutex held.
3861 */
3862 static
3863 int _lttng_session_metadata_statedump(struct lttng_session *session)
3864 {
3865 unsigned char *uuid_c = session->uuid.b;
3866 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3867 const char *product_uuid;
3868 struct lttng_channel *chan;
3869 struct lttng_kernel_event_recorder_private *event_recorder_priv;
3870 int ret = 0;
3871
3872 if (!LTTNG_READ_ONCE(session->active))
3873 return 0;
3874
3875 lttng_metadata_begin(session);
3876
3877 if (session->metadata_dumped)
3878 goto skip_session;
3879
3880 snprintf(uuid_s, sizeof(uuid_s),
3881 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3882 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3883 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3884 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3885 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3886
3887 ret = lttng_metadata_printf(session,
3888 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3889 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3890 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3891 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3892 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3893 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3894 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3895 "\n"
3896 "trace {\n"
3897 " major = %u;\n"
3898 " minor = %u;\n"
3899 " uuid = \"%s\";\n"
3900 " byte_order = %s;\n"
3901 " packet.header := struct {\n"
3902 " uint32_t magic;\n"
3903 " uint8_t uuid[16];\n"
3904 " uint32_t stream_id;\n"
3905 " uint64_t stream_instance_id;\n"
3906 " };\n"
3907 "};\n\n",
3908 lttng_alignof(uint8_t) * CHAR_BIT,
3909 lttng_alignof(uint16_t) * CHAR_BIT,
3910 lttng_alignof(uint32_t) * CHAR_BIT,
3911 lttng_alignof(uint64_t) * CHAR_BIT,
3912 sizeof(unsigned long) * CHAR_BIT,
3913 lttng_alignof(unsigned long) * CHAR_BIT,
3914 CTF_SPEC_MAJOR,
3915 CTF_SPEC_MINOR,
3916 uuid_s,
3917 #if __BYTE_ORDER == __BIG_ENDIAN
3918 "be"
3919 #else
3920 "le"
3921 #endif
3922 );
3923 if (ret)
3924 goto end;
3925
3926 ret = lttng_metadata_printf(session,
3927 "env {\n"
3928 " hostname = \"%s\";\n"
3929 " domain = \"kernel\";\n"
3930 " sysname = \"%s\";\n"
3931 " kernel_release = \"%s\";\n"
3932 " kernel_version = \"%s\";\n"
3933 " tracer_name = \"lttng-modules\";\n"
3934 " tracer_major = %d;\n"
3935 " tracer_minor = %d;\n"
3936 " tracer_patchlevel = %d;\n"
3937 " trace_buffering_scheme = \"global\";\n",
3938 current->nsproxy->uts_ns->name.nodename,
3939 utsname()->sysname,
3940 utsname()->release,
3941 utsname()->version,
3942 LTTNG_MODULES_MAJOR_VERSION,
3943 LTTNG_MODULES_MINOR_VERSION,
3944 LTTNG_MODULES_PATCHLEVEL_VERSION
3945 );
3946 if (ret)
3947 goto end;
3948
3949 ret = print_metadata_escaped_field(session, "trace_name", session->name);
3950 if (ret)
3951 goto end;
3952 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
3953 session->creation_time);
3954 if (ret)
3955 goto end;
3956
3957 /* Add the product UUID to the 'env' section */
3958 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
3959 if (product_uuid) {
3960 ret = lttng_metadata_printf(session,
3961 " product_uuid = \"%s\";\n",
3962 product_uuid
3963 );
3964 if (ret)
3965 goto end;
3966 }
3967
3968 /* Close the 'env' section */
3969 ret = lttng_metadata_printf(session, "};\n\n");
3970 if (ret)
3971 goto end;
3972
3973 ret = lttng_metadata_printf(session,
3974 "clock {\n"
3975 " name = \"%s\";\n",
3976 trace_clock_name()
3977 );
3978 if (ret)
3979 goto end;
3980
3981 if (!trace_clock_uuid(clock_uuid_s)) {
3982 ret = lttng_metadata_printf(session,
3983 " uuid = \"%s\";\n",
3984 clock_uuid_s
3985 );
3986 if (ret)
3987 goto end;
3988 }
3989
3990 ret = lttng_metadata_printf(session,
3991 " description = \"%s\";\n"
3992 " freq = %llu; /* Frequency, in Hz */\n"
3993 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
3994 " offset = %lld;\n"
3995 "};\n\n",
3996 trace_clock_description(),
3997 (unsigned long long) trace_clock_freq(),
3998 (long long) measure_clock_offset()
3999 );
4000 if (ret)
4001 goto end;
4002
4003 ret = lttng_metadata_printf(session,
4004 "typealias integer {\n"
4005 " size = 27; align = 1; signed = false;\n"
4006 " map = clock.%s.value;\n"
4007 "} := uint27_clock_monotonic_t;\n"
4008 "\n"
4009 "typealias integer {\n"
4010 " size = 32; align = %u; signed = false;\n"
4011 " map = clock.%s.value;\n"
4012 "} := uint32_clock_monotonic_t;\n"
4013 "\n"
4014 "typealias integer {\n"
4015 " size = 64; align = %u; signed = false;\n"
4016 " map = clock.%s.value;\n"
4017 "} := uint64_clock_monotonic_t;\n\n",
4018 trace_clock_name(),
4019 lttng_alignof(uint32_t) * CHAR_BIT,
4020 trace_clock_name(),
4021 lttng_alignof(uint64_t) * CHAR_BIT,
4022 trace_clock_name()
4023 );
4024 if (ret)
4025 goto end;
4026
4027 ret = _lttng_stream_packet_context_declare(session);
4028 if (ret)
4029 goto end;
4030
4031 ret = _lttng_event_header_declare(session);
4032 if (ret)
4033 goto end;
4034
4035 skip_session:
4036 list_for_each_entry(chan, &session->chan, list) {
4037 ret = _lttng_channel_metadata_statedump(session, chan);
4038 if (ret)
4039 goto end;
4040 }
4041
4042 list_for_each_entry(event_recorder_priv, &session->events, node) {
4043 ret = _lttng_event_metadata_statedump(session, event_recorder_priv->pub->chan,
4044 event_recorder_priv->pub);
4045 if (ret)
4046 goto end;
4047 }
4048 session->metadata_dumped = 1;
4049 end:
4050 lttng_metadata_end(session);
4051 return ret;
4052 }
4053
4054 /**
4055 * lttng_transport_register - LTT transport registration
4056 * @transport: transport structure
4057 *
4058 * Registers a transport which can be used as output to extract the data out of
4059 * LTTng. The module calling this registration function must ensure that no
4060 * trap-inducing code will be executed by the transport functions. E.g.
4061 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
4062 * is made visible to the transport function. This registration acts as a
4063 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
4064 * after its registration must it synchronize the TLBs.
4065 */
4066 void lttng_transport_register(struct lttng_transport *transport)
4067 {
4068 /*
4069 * Make sure no page fault can be triggered by the module about to be
4070 * registered. We deal with this here so we don't have to call
4071 * vmalloc_sync_mappings() in each module's init.
4072 */
4073 wrapper_vmalloc_sync_mappings();
4074
4075 mutex_lock(&sessions_mutex);
4076 list_add_tail(&transport->node, &lttng_transport_list);
4077 mutex_unlock(&sessions_mutex);
4078 }
4079 EXPORT_SYMBOL_GPL(lttng_transport_register);
4080
4081 /**
4082 * lttng_transport_unregister - LTT transport unregistration
4083 * @transport: transport structure
4084 */
4085 void lttng_transport_unregister(struct lttng_transport *transport)
4086 {
4087 mutex_lock(&sessions_mutex);
4088 list_del(&transport->node);
4089 mutex_unlock(&sessions_mutex);
4090 }
4091 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4092
4093 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4094 {
4095 /*
4096 * Make sure no page fault can be triggered by the module about to be
4097 * registered. We deal with this here so we don't have to call
4098 * vmalloc_sync_mappings() in each module's init.
4099 */
4100 wrapper_vmalloc_sync_mappings();
4101
4102 mutex_lock(&sessions_mutex);
4103 list_add_tail(&transport->node, &lttng_counter_transport_list);
4104 mutex_unlock(&sessions_mutex);
4105 }
4106 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4107
4108 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4109 {
4110 mutex_lock(&sessions_mutex);
4111 list_del(&transport->node);
4112 mutex_unlock(&sessions_mutex);
4113 }
4114 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4115
4116 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4117
4118 enum cpuhp_state lttng_hp_prepare;
4119 enum cpuhp_state lttng_hp_online;
4120
4121 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4122 {
4123 struct lttng_cpuhp_node *lttng_node;
4124
4125 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4126 switch (lttng_node->component) {
4127 case LTTNG_RING_BUFFER_FRONTEND:
4128 return 0;
4129 case LTTNG_RING_BUFFER_BACKEND:
4130 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4131 case LTTNG_RING_BUFFER_ITER:
4132 return 0;
4133 case LTTNG_CONTEXT_PERF_COUNTERS:
4134 return 0;
4135 default:
4136 return -EINVAL;
4137 }
4138 }
4139
4140 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4141 {
4142 struct lttng_cpuhp_node *lttng_node;
4143
4144 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4145 switch (lttng_node->component) {
4146 case LTTNG_RING_BUFFER_FRONTEND:
4147 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4148 case LTTNG_RING_BUFFER_BACKEND:
4149 return 0;
4150 case LTTNG_RING_BUFFER_ITER:
4151 return 0;
4152 case LTTNG_CONTEXT_PERF_COUNTERS:
4153 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4154 default:
4155 return -EINVAL;
4156 }
4157 }
4158
4159 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4160 {
4161 struct lttng_cpuhp_node *lttng_node;
4162
4163 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4164 switch (lttng_node->component) {
4165 case LTTNG_RING_BUFFER_FRONTEND:
4166 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4167 case LTTNG_RING_BUFFER_BACKEND:
4168 return 0;
4169 case LTTNG_RING_BUFFER_ITER:
4170 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4171 case LTTNG_CONTEXT_PERF_COUNTERS:
4172 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4173 default:
4174 return -EINVAL;
4175 }
4176 }
4177
4178 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4179 {
4180 struct lttng_cpuhp_node *lttng_node;
4181
4182 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4183 switch (lttng_node->component) {
4184 case LTTNG_RING_BUFFER_FRONTEND:
4185 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4186 case LTTNG_RING_BUFFER_BACKEND:
4187 return 0;
4188 case LTTNG_RING_BUFFER_ITER:
4189 return 0;
4190 case LTTNG_CONTEXT_PERF_COUNTERS:
4191 return 0;
4192 default:
4193 return -EINVAL;
4194 }
4195 }
4196
4197 static int __init lttng_init_cpu_hotplug(void)
4198 {
4199 int ret;
4200
4201 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4202 lttng_hotplug_prepare,
4203 lttng_hotplug_dead);
4204 if (ret < 0) {
4205 return ret;
4206 }
4207 lttng_hp_prepare = ret;
4208 lttng_rb_set_hp_prepare(ret);
4209
4210 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4211 lttng_hotplug_online,
4212 lttng_hotplug_offline);
4213 if (ret < 0) {
4214 cpuhp_remove_multi_state(lttng_hp_prepare);
4215 lttng_hp_prepare = 0;
4216 return ret;
4217 }
4218 lttng_hp_online = ret;
4219 lttng_rb_set_hp_online(ret);
4220
4221 return 0;
4222 }
4223
4224 static void __exit lttng_exit_cpu_hotplug(void)
4225 {
4226 lttng_rb_set_hp_online(0);
4227 cpuhp_remove_multi_state(lttng_hp_online);
4228 lttng_rb_set_hp_prepare(0);
4229 cpuhp_remove_multi_state(lttng_hp_prepare);
4230 }
4231
4232 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4233 static int lttng_init_cpu_hotplug(void)
4234 {
4235 return 0;
4236 }
4237 static void lttng_exit_cpu_hotplug(void)
4238 {
4239 }
4240 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4241
4242
4243 static int __init lttng_events_init(void)
4244 {
4245 int ret;
4246
4247 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4248 if (ret)
4249 return ret;
4250 ret = wrapper_get_pfnblock_flags_mask_init();
4251 if (ret)
4252 return ret;
4253 ret = wrapper_get_pageblock_flags_mask_init();
4254 if (ret)
4255 return ret;
4256 ret = lttng_probes_init();
4257 if (ret)
4258 return ret;
4259 ret = lttng_context_init();
4260 if (ret)
4261 return ret;
4262 ret = lttng_tracepoint_init();
4263 if (ret)
4264 goto error_tp;
4265 event_recorder_cache = KMEM_CACHE(lttng_kernel_event_recorder, 0);
4266 if (!event_recorder_cache) {
4267 ret = -ENOMEM;
4268 goto error_kmem_event_recorder;
4269 }
4270 event_recorder_private_cache = KMEM_CACHE(lttng_kernel_event_recorder_private, 0);
4271 if (!event_recorder_private_cache) {
4272 ret = -ENOMEM;
4273 goto error_kmem_event_recorder_private;
4274 }
4275 event_notifier_cache = KMEM_CACHE(lttng_kernel_event_notifier, 0);
4276 if (!event_notifier_cache) {
4277 ret = -ENOMEM;
4278 goto error_kmem_event_notifier;
4279 }
4280 event_notifier_private_cache = KMEM_CACHE(lttng_kernel_event_notifier_private, 0);
4281 if (!event_notifier_private_cache) {
4282 ret = -ENOMEM;
4283 goto error_kmem_event_notifier_private;
4284 }
4285 ret = lttng_abi_init();
4286 if (ret)
4287 goto error_abi;
4288 ret = lttng_logger_init();
4289 if (ret)
4290 goto error_logger;
4291 ret = lttng_init_cpu_hotplug();
4292 if (ret)
4293 goto error_hotplug;
4294 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4295 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4296 __stringify(LTTNG_MODULES_MINOR_VERSION),
4297 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4298 LTTNG_MODULES_EXTRAVERSION,
4299 LTTNG_VERSION_NAME,
4300 #ifdef LTTNG_EXTRA_VERSION_GIT
4301 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4302 #else
4303 "",
4304 #endif
4305 #ifdef LTTNG_EXTRA_VERSION_NAME
4306 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4307 #else
4308 "");
4309 #endif
4310 return 0;
4311
4312 error_hotplug:
4313 lttng_logger_exit();
4314 error_logger:
4315 lttng_abi_exit();
4316 error_abi:
4317 kmem_cache_destroy(event_notifier_private_cache);
4318 error_kmem_event_notifier_private:
4319 kmem_cache_destroy(event_notifier_cache);
4320 error_kmem_event_notifier:
4321 kmem_cache_destroy(event_recorder_private_cache);
4322 error_kmem_event_recorder_private:
4323 kmem_cache_destroy(event_recorder_cache);
4324 error_kmem_event_recorder:
4325 lttng_tracepoint_exit();
4326 error_tp:
4327 lttng_context_exit();
4328 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4329 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4330 __stringify(LTTNG_MODULES_MINOR_VERSION),
4331 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4332 LTTNG_MODULES_EXTRAVERSION,
4333 LTTNG_VERSION_NAME,
4334 #ifdef LTTNG_EXTRA_VERSION_GIT
4335 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4336 #else
4337 "",
4338 #endif
4339 #ifdef LTTNG_EXTRA_VERSION_NAME
4340 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4341 #else
4342 "");
4343 #endif
4344 return ret;
4345 }
4346
4347 module_init(lttng_events_init);
4348
4349 static void __exit lttng_events_exit(void)
4350 {
4351 struct lttng_session *session, *tmpsession;
4352
4353 lttng_exit_cpu_hotplug();
4354 lttng_logger_exit();
4355 lttng_abi_exit();
4356 list_for_each_entry_safe(session, tmpsession, &sessions, list)
4357 lttng_session_destroy(session);
4358 kmem_cache_destroy(event_recorder_cache);
4359 kmem_cache_destroy(event_recorder_private_cache);
4360 kmem_cache_destroy(event_notifier_cache);
4361 kmem_cache_destroy(event_notifier_private_cache);
4362 lttng_tracepoint_exit();
4363 lttng_context_exit();
4364 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4365 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4366 __stringify(LTTNG_MODULES_MINOR_VERSION),
4367 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4368 LTTNG_MODULES_EXTRAVERSION,
4369 LTTNG_VERSION_NAME,
4370 #ifdef LTTNG_EXTRA_VERSION_GIT
4371 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4372 #else
4373 "",
4374 #endif
4375 #ifdef LTTNG_EXTRA_VERSION_NAME
4376 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4377 #else
4378 "");
4379 #endif
4380 }
4381
4382 module_exit(lttng_events_exit);
4383
4384 #include <generated/patches.h>
4385 #ifdef LTTNG_EXTRA_VERSION_GIT
4386 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4387 #endif
4388 #ifdef LTTNG_EXTRA_VERSION_NAME
4389 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4390 #endif
4391 MODULE_LICENSE("GPL and additional rights");
4392 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4393 MODULE_DESCRIPTION("LTTng tracer");
4394 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4395 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4396 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4397 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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