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