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Namespace kernel version macros
[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/lttng-bytecode.h>
40 #include <lttng/tracer.h>
41 #include <lttng/event-notifier-notification.h>
42 #include <lttng/abi-old.h>
43 #include <lttng/endian.h>
44 #include <lttng/string-utils.h>
45 #include <lttng/utils.h>
46 #include <ringbuffer/backend.h>
47 #include <ringbuffer/frontend.h>
48 #include <wrapper/time.h>
49
50 #define METADATA_CACHE_DEFAULT_SIZE 4096
51
52 static LIST_HEAD(sessions);
53 static LIST_HEAD(event_notifier_groups);
54 static LIST_HEAD(lttng_transport_list);
55 static LIST_HEAD(lttng_counter_transport_list);
56 /*
57 * Protect the sessions and metadata caches.
58 */
59 static DEFINE_MUTEX(sessions_mutex);
60 static struct kmem_cache *event_cache;
61 static struct kmem_cache *event_notifier_cache;
62
63 static void lttng_session_lazy_sync_event_enablers(struct lttng_session *session);
64 static void lttng_session_sync_event_enablers(struct lttng_session *session);
65 static void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler);
66 static void lttng_event_notifier_enabler_destroy(struct lttng_event_notifier_enabler *event_notifier_enabler);
67 static void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group);
68
69 static void _lttng_event_destroy(struct lttng_event *event);
70 static void _lttng_event_notifier_destroy(struct lttng_event_notifier *event_notifier);
71 static void _lttng_channel_destroy(struct lttng_channel *chan);
72 static int _lttng_event_unregister(struct lttng_event *event);
73 static int _lttng_event_notifier_unregister(struct lttng_event_notifier *event_notifier);
74 static
75 int _lttng_event_metadata_statedump(struct lttng_session *session,
76 struct lttng_channel *chan,
77 struct lttng_event *event);
78 static
79 int _lttng_session_metadata_statedump(struct lttng_session *session);
80 static
81 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
82 static
83 int _lttng_type_statedump(struct lttng_session *session,
84 const struct lttng_type *type,
85 size_t nesting);
86 static
87 int _lttng_field_statedump(struct lttng_session *session,
88 const struct lttng_event_field *field,
89 size_t nesting);
90
91 void synchronize_trace(void)
92 {
93 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,1,0))
94 synchronize_rcu();
95 #else
96 synchronize_sched();
97 #endif
98
99 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0))
100 #ifdef CONFIG_PREEMPT_RT_FULL
101 synchronize_rcu();
102 #endif
103 #else /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
104 #ifdef CONFIG_PREEMPT_RT
105 synchronize_rcu();
106 #endif
107 #endif /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
108 }
109
110 void lttng_lock_sessions(void)
111 {
112 mutex_lock(&sessions_mutex);
113 }
114
115 void lttng_unlock_sessions(void)
116 {
117 mutex_unlock(&sessions_mutex);
118 }
119
120 static struct lttng_transport *lttng_transport_find(const char *name)
121 {
122 struct lttng_transport *transport;
123
124 list_for_each_entry(transport, &lttng_transport_list, node) {
125 if (!strcmp(transport->name, name))
126 return transport;
127 }
128 return NULL;
129 }
130
131 /*
132 * Called with sessions lock held.
133 */
134 int lttng_session_active(void)
135 {
136 struct lttng_session *iter;
137
138 list_for_each_entry(iter, &sessions, list) {
139 if (iter->active)
140 return 1;
141 }
142 return 0;
143 }
144
145 struct lttng_session *lttng_session_create(void)
146 {
147 struct lttng_session *session;
148 struct lttng_metadata_cache *metadata_cache;
149 int i;
150
151 mutex_lock(&sessions_mutex);
152 session = lttng_kvzalloc(sizeof(struct lttng_session), GFP_KERNEL);
153 if (!session)
154 goto err;
155 INIT_LIST_HEAD(&session->chan);
156 INIT_LIST_HEAD(&session->events);
157 lttng_guid_gen(&session->uuid);
158
159 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
160 GFP_KERNEL);
161 if (!metadata_cache)
162 goto err_free_session;
163 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
164 if (!metadata_cache->data)
165 goto err_free_cache;
166 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
167 kref_init(&metadata_cache->refcount);
168 mutex_init(&metadata_cache->lock);
169 session->metadata_cache = metadata_cache;
170 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
171 memcpy(&metadata_cache->uuid, &session->uuid,
172 sizeof(metadata_cache->uuid));
173 INIT_LIST_HEAD(&session->enablers_head);
174 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
175 INIT_HLIST_HEAD(&session->events_ht.table[i]);
176 list_add(&session->list, &sessions);
177 session->pid_tracker.session = session;
178 session->pid_tracker.tracker_type = TRACKER_PID;
179 session->vpid_tracker.session = session;
180 session->vpid_tracker.tracker_type = TRACKER_VPID;
181 session->uid_tracker.session = session;
182 session->uid_tracker.tracker_type = TRACKER_UID;
183 session->vuid_tracker.session = session;
184 session->vuid_tracker.tracker_type = TRACKER_VUID;
185 session->gid_tracker.session = session;
186 session->gid_tracker.tracker_type = TRACKER_GID;
187 session->vgid_tracker.session = session;
188 session->vgid_tracker.tracker_type = TRACKER_VGID;
189 mutex_unlock(&sessions_mutex);
190 return session;
191
192 err_free_cache:
193 kfree(metadata_cache);
194 err_free_session:
195 lttng_kvfree(session);
196 err:
197 mutex_unlock(&sessions_mutex);
198 return NULL;
199 }
200
201 static
202 struct lttng_counter_transport *lttng_counter_transport_find(const char *name)
203 {
204 struct lttng_counter_transport *transport;
205
206 list_for_each_entry(transport, &lttng_counter_transport_list, node) {
207 if (!strcmp(transport->name, name))
208 return transport;
209 }
210 return NULL;
211 }
212
213 struct lttng_counter *lttng_kernel_counter_create(
214 const char *counter_transport_name,
215 size_t number_dimensions, const size_t *dimensions_sizes)
216 {
217 struct lttng_counter *counter = NULL;
218 struct lttng_counter_transport *counter_transport = NULL;
219
220 counter_transport = lttng_counter_transport_find(counter_transport_name);
221 if (!counter_transport) {
222 printk(KERN_WARNING "LTTng: counter transport %s not found.\n",
223 counter_transport_name);
224 goto notransport;
225 }
226 if (!try_module_get(counter_transport->owner)) {
227 printk(KERN_WARNING "LTTng: Can't lock counter transport module.\n");
228 goto notransport;
229 }
230
231 counter = lttng_kvzalloc(sizeof(struct lttng_counter), GFP_KERNEL);
232 if (!counter)
233 goto nomem;
234
235 /* Create event notifier error counter. */
236 counter->ops = &counter_transport->ops;
237 counter->transport = counter_transport;
238
239 counter->counter = counter->ops->counter_create(
240 number_dimensions, dimensions_sizes, 0);
241 if (!counter->counter) {
242 goto create_error;
243 }
244
245 return counter;
246
247 create_error:
248 lttng_kvfree(counter);
249 nomem:
250 if (counter_transport)
251 module_put(counter_transport->owner);
252 notransport:
253 return NULL;
254 }
255
256 struct lttng_event_notifier_group *lttng_event_notifier_group_create(void)
257 {
258 struct lttng_transport *transport = NULL;
259 struct lttng_event_notifier_group *event_notifier_group;
260 const char *transport_name = "relay-event-notifier";
261 size_t subbuf_size = 4096; //TODO
262 size_t num_subbuf = 16; //TODO
263 unsigned int switch_timer_interval = 0;
264 unsigned int read_timer_interval = 0;
265 int i;
266
267 mutex_lock(&sessions_mutex);
268
269 transport = lttng_transport_find(transport_name);
270 if (!transport) {
271 printk(KERN_WARNING "LTTng: transport %s not found\n",
272 transport_name);
273 goto notransport;
274 }
275 if (!try_module_get(transport->owner)) {
276 printk(KERN_WARNING "LTTng: Can't lock transport %s module.\n",
277 transport_name);
278 goto notransport;
279 }
280
281 event_notifier_group = lttng_kvzalloc(sizeof(struct lttng_event_notifier_group),
282 GFP_KERNEL);
283 if (!event_notifier_group)
284 goto nomem;
285
286 /*
287 * Initialize the ring buffer used to store event notifier
288 * notifications.
289 */
290 event_notifier_group->ops = &transport->ops;
291 event_notifier_group->chan = transport->ops.channel_create(
292 transport_name, event_notifier_group, NULL,
293 subbuf_size, num_subbuf, switch_timer_interval,
294 read_timer_interval);
295 if (!event_notifier_group->chan)
296 goto create_error;
297
298 event_notifier_group->transport = transport;
299
300 INIT_LIST_HEAD(&event_notifier_group->enablers_head);
301 INIT_LIST_HEAD(&event_notifier_group->event_notifiers_head);
302 for (i = 0; i < LTTNG_EVENT_NOTIFIER_HT_SIZE; i++)
303 INIT_HLIST_HEAD(&event_notifier_group->event_notifiers_ht.table[i]);
304
305 list_add(&event_notifier_group->node, &event_notifier_groups);
306
307 mutex_unlock(&sessions_mutex);
308
309 return event_notifier_group;
310
311 create_error:
312 lttng_kvfree(event_notifier_group);
313 nomem:
314 if (transport)
315 module_put(transport->owner);
316 notransport:
317 mutex_unlock(&sessions_mutex);
318 return NULL;
319 }
320
321 void metadata_cache_destroy(struct kref *kref)
322 {
323 struct lttng_metadata_cache *cache =
324 container_of(kref, struct lttng_metadata_cache, refcount);
325 vfree(cache->data);
326 kfree(cache);
327 }
328
329 void lttng_session_destroy(struct lttng_session *session)
330 {
331 struct lttng_channel *chan, *tmpchan;
332 struct lttng_event *event, *tmpevent;
333 struct lttng_metadata_stream *metadata_stream;
334 struct lttng_event_enabler *event_enabler, *tmp_event_enabler;
335 int ret;
336
337 mutex_lock(&sessions_mutex);
338 WRITE_ONCE(session->active, 0);
339 list_for_each_entry(chan, &session->chan, list) {
340 ret = lttng_syscalls_unregister_channel(chan);
341 WARN_ON(ret);
342 }
343 list_for_each_entry(event, &session->events, list) {
344 ret = _lttng_event_unregister(event);
345 WARN_ON(ret);
346 }
347 synchronize_trace(); /* Wait for in-flight events to complete */
348 list_for_each_entry(chan, &session->chan, list) {
349 ret = lttng_syscalls_destroy_event(chan);
350 WARN_ON(ret);
351 }
352 list_for_each_entry_safe(event_enabler, tmp_event_enabler,
353 &session->enablers_head, node)
354 lttng_event_enabler_destroy(event_enabler);
355 list_for_each_entry_safe(event, tmpevent, &session->events, list)
356 _lttng_event_destroy(event);
357 list_for_each_entry_safe(chan, tmpchan, &session->chan, list) {
358 BUG_ON(chan->channel_type == METADATA_CHANNEL);
359 _lttng_channel_destroy(chan);
360 }
361 mutex_lock(&session->metadata_cache->lock);
362 list_for_each_entry(metadata_stream, &session->metadata_cache->metadata_stream, list)
363 _lttng_metadata_channel_hangup(metadata_stream);
364 mutex_unlock(&session->metadata_cache->lock);
365 lttng_id_tracker_destroy(&session->pid_tracker, false);
366 lttng_id_tracker_destroy(&session->vpid_tracker, false);
367 lttng_id_tracker_destroy(&session->uid_tracker, false);
368 lttng_id_tracker_destroy(&session->vuid_tracker, false);
369 lttng_id_tracker_destroy(&session->gid_tracker, false);
370 lttng_id_tracker_destroy(&session->vgid_tracker, false);
371 kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
372 list_del(&session->list);
373 mutex_unlock(&sessions_mutex);
374 lttng_kvfree(session);
375 }
376
377 void lttng_event_notifier_group_destroy(
378 struct lttng_event_notifier_group *event_notifier_group)
379 {
380 struct lttng_event_notifier_enabler *event_notifier_enabler, *tmp_event_notifier_enabler;
381 struct lttng_event_notifier *event_notifier, *tmpevent_notifier;
382 int ret;
383
384 if (!event_notifier_group)
385 return;
386
387 mutex_lock(&sessions_mutex);
388
389 ret = lttng_syscalls_unregister_event_notifier_group(event_notifier_group);
390 WARN_ON(ret);
391
392 list_for_each_entry_safe(event_notifier, tmpevent_notifier,
393 &event_notifier_group->event_notifiers_head, list) {
394 ret = _lttng_event_notifier_unregister(event_notifier);
395 WARN_ON(ret);
396 }
397
398 /* Wait for in-flight event notifier to complete */
399 synchronize_trace();
400
401 irq_work_sync(&event_notifier_group->wakeup_pending);
402
403 kfree(event_notifier_group->sc_filter);
404
405 list_for_each_entry_safe(event_notifier_enabler, tmp_event_notifier_enabler,
406 &event_notifier_group->enablers_head, node)
407 lttng_event_notifier_enabler_destroy(event_notifier_enabler);
408
409 list_for_each_entry_safe(event_notifier, tmpevent_notifier,
410 &event_notifier_group->event_notifiers_head, list)
411 _lttng_event_notifier_destroy(event_notifier);
412
413 if (event_notifier_group->error_counter) {
414 struct lttng_counter *error_counter = event_notifier_group->error_counter;
415
416 error_counter->ops->counter_destroy(error_counter->counter);
417 module_put(error_counter->transport->owner);
418 lttng_kvfree(error_counter);
419 event_notifier_group->error_counter = NULL;
420 }
421
422 event_notifier_group->ops->channel_destroy(event_notifier_group->chan);
423 module_put(event_notifier_group->transport->owner);
424 list_del(&event_notifier_group->node);
425
426 mutex_unlock(&sessions_mutex);
427 lttng_kvfree(event_notifier_group);
428 }
429
430 int lttng_session_statedump(struct lttng_session *session)
431 {
432 int ret;
433
434 mutex_lock(&sessions_mutex);
435 ret = lttng_statedump_start(session);
436 mutex_unlock(&sessions_mutex);
437 return ret;
438 }
439
440 int lttng_session_enable(struct lttng_session *session)
441 {
442 int ret = 0;
443 struct lttng_channel *chan;
444
445 mutex_lock(&sessions_mutex);
446 if (session->active) {
447 ret = -EBUSY;
448 goto end;
449 }
450
451 /* Set transient enabler state to "enabled" */
452 session->tstate = 1;
453
454 /* We need to sync enablers with session before activation. */
455 lttng_session_sync_event_enablers(session);
456
457 /*
458 * Snapshot the number of events per channel to know the type of header
459 * we need to use.
460 */
461 list_for_each_entry(chan, &session->chan, list) {
462 if (chan->header_type)
463 continue; /* don't change it if session stop/restart */
464 if (chan->free_event_id < 31)
465 chan->header_type = 1; /* compact */
466 else
467 chan->header_type = 2; /* large */
468 }
469
470 /* Clear each stream's quiescent state. */
471 list_for_each_entry(chan, &session->chan, list) {
472 if (chan->channel_type != METADATA_CHANNEL)
473 lib_ring_buffer_clear_quiescent_channel(chan->chan);
474 }
475
476 WRITE_ONCE(session->active, 1);
477 WRITE_ONCE(session->been_active, 1);
478 ret = _lttng_session_metadata_statedump(session);
479 if (ret) {
480 WRITE_ONCE(session->active, 0);
481 goto end;
482 }
483 ret = lttng_statedump_start(session);
484 if (ret)
485 WRITE_ONCE(session->active, 0);
486 end:
487 mutex_unlock(&sessions_mutex);
488 return ret;
489 }
490
491 int lttng_session_disable(struct lttng_session *session)
492 {
493 int ret = 0;
494 struct lttng_channel *chan;
495
496 mutex_lock(&sessions_mutex);
497 if (!session->active) {
498 ret = -EBUSY;
499 goto end;
500 }
501 WRITE_ONCE(session->active, 0);
502
503 /* Set transient enabler state to "disabled" */
504 session->tstate = 0;
505 lttng_session_sync_event_enablers(session);
506
507 /* Set each stream's quiescent state. */
508 list_for_each_entry(chan, &session->chan, list) {
509 if (chan->channel_type != METADATA_CHANNEL)
510 lib_ring_buffer_set_quiescent_channel(chan->chan);
511 }
512 end:
513 mutex_unlock(&sessions_mutex);
514 return ret;
515 }
516
517 int lttng_session_metadata_regenerate(struct lttng_session *session)
518 {
519 int ret = 0;
520 struct lttng_channel *chan;
521 struct lttng_event *event;
522 struct lttng_metadata_cache *cache = session->metadata_cache;
523 struct lttng_metadata_stream *stream;
524
525 mutex_lock(&sessions_mutex);
526 if (!session->active) {
527 ret = -EBUSY;
528 goto end;
529 }
530
531 mutex_lock(&cache->lock);
532 memset(cache->data, 0, cache->cache_alloc);
533 cache->metadata_written = 0;
534 cache->version++;
535 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list) {
536 stream->metadata_out = 0;
537 stream->metadata_in = 0;
538 }
539 mutex_unlock(&cache->lock);
540
541 session->metadata_dumped = 0;
542 list_for_each_entry(chan, &session->chan, list) {
543 chan->metadata_dumped = 0;
544 }
545
546 list_for_each_entry(event, &session->events, list) {
547 event->metadata_dumped = 0;
548 }
549
550 ret = _lttng_session_metadata_statedump(session);
551
552 end:
553 mutex_unlock(&sessions_mutex);
554 return ret;
555 }
556
557 int lttng_channel_enable(struct lttng_channel *channel)
558 {
559 int ret = 0;
560
561 mutex_lock(&sessions_mutex);
562 if (channel->channel_type == METADATA_CHANNEL) {
563 ret = -EPERM;
564 goto end;
565 }
566 if (channel->enabled) {
567 ret = -EEXIST;
568 goto end;
569 }
570 /* Set transient enabler state to "enabled" */
571 channel->tstate = 1;
572 lttng_session_sync_event_enablers(channel->session);
573 /* Set atomically the state to "enabled" */
574 WRITE_ONCE(channel->enabled, 1);
575 end:
576 mutex_unlock(&sessions_mutex);
577 return ret;
578 }
579
580 int lttng_channel_disable(struct lttng_channel *channel)
581 {
582 int ret = 0;
583
584 mutex_lock(&sessions_mutex);
585 if (channel->channel_type == METADATA_CHANNEL) {
586 ret = -EPERM;
587 goto end;
588 }
589 if (!channel->enabled) {
590 ret = -EEXIST;
591 goto end;
592 }
593 /* Set atomically the state to "disabled" */
594 WRITE_ONCE(channel->enabled, 0);
595 /* Set transient enabler state to "enabled" */
596 channel->tstate = 0;
597 lttng_session_sync_event_enablers(channel->session);
598 end:
599 mutex_unlock(&sessions_mutex);
600 return ret;
601 }
602
603 int lttng_event_enable(struct lttng_event *event)
604 {
605 int ret = 0;
606
607 mutex_lock(&sessions_mutex);
608 if (event->chan->channel_type == METADATA_CHANNEL) {
609 ret = -EPERM;
610 goto end;
611 }
612 if (event->enabled) {
613 ret = -EEXIST;
614 goto end;
615 }
616 switch (event->instrumentation) {
617 case LTTNG_KERNEL_TRACEPOINT:
618 case LTTNG_KERNEL_SYSCALL:
619 ret = -EINVAL;
620 break;
621 case LTTNG_KERNEL_KPROBE:
622 case LTTNG_KERNEL_UPROBE:
623 case LTTNG_KERNEL_NOOP:
624 WRITE_ONCE(event->enabled, 1);
625 break;
626 case LTTNG_KERNEL_KRETPROBE:
627 ret = lttng_kretprobes_event_enable_state(event, 1);
628 break;
629 case LTTNG_KERNEL_FUNCTION: /* Fall-through. */
630 default:
631 WARN_ON_ONCE(1);
632 ret = -EINVAL;
633 }
634 end:
635 mutex_unlock(&sessions_mutex);
636 return ret;
637 }
638
639 int lttng_event_disable(struct lttng_event *event)
640 {
641 int ret = 0;
642
643 mutex_lock(&sessions_mutex);
644 if (event->chan->channel_type == METADATA_CHANNEL) {
645 ret = -EPERM;
646 goto end;
647 }
648 if (!event->enabled) {
649 ret = -EEXIST;
650 goto end;
651 }
652 switch (event->instrumentation) {
653 case LTTNG_KERNEL_TRACEPOINT:
654 case LTTNG_KERNEL_SYSCALL:
655 ret = -EINVAL;
656 break;
657 case LTTNG_KERNEL_KPROBE:
658 case LTTNG_KERNEL_UPROBE:
659 case LTTNG_KERNEL_NOOP:
660 WRITE_ONCE(event->enabled, 0);
661 break;
662 case LTTNG_KERNEL_KRETPROBE:
663 ret = lttng_kretprobes_event_enable_state(event, 0);
664 break;
665 case LTTNG_KERNEL_FUNCTION: /* Fall-through. */
666 default:
667 WARN_ON_ONCE(1);
668 ret = -EINVAL;
669 }
670 end:
671 mutex_unlock(&sessions_mutex);
672 return ret;
673 }
674
675 int lttng_event_notifier_enable(struct lttng_event_notifier *event_notifier)
676 {
677 int ret = 0;
678
679 mutex_lock(&sessions_mutex);
680 if (event_notifier->enabled) {
681 ret = -EEXIST;
682 goto end;
683 }
684 switch (event_notifier->instrumentation) {
685 case LTTNG_KERNEL_TRACEPOINT:
686 case LTTNG_KERNEL_SYSCALL:
687 ret = -EINVAL;
688 break;
689 case LTTNG_KERNEL_KPROBE:
690 case LTTNG_KERNEL_UPROBE:
691 WRITE_ONCE(event_notifier->enabled, 1);
692 break;
693 case LTTNG_KERNEL_FUNCTION:
694 case LTTNG_KERNEL_NOOP:
695 case LTTNG_KERNEL_KRETPROBE:
696 default:
697 WARN_ON_ONCE(1);
698 ret = -EINVAL;
699 }
700 end:
701 mutex_unlock(&sessions_mutex);
702 return ret;
703 }
704
705 int lttng_event_notifier_disable(struct lttng_event_notifier *event_notifier)
706 {
707 int ret = 0;
708
709 mutex_lock(&sessions_mutex);
710 if (!event_notifier->enabled) {
711 ret = -EEXIST;
712 goto end;
713 }
714 switch (event_notifier->instrumentation) {
715 case LTTNG_KERNEL_TRACEPOINT:
716 case LTTNG_KERNEL_SYSCALL:
717 ret = -EINVAL;
718 break;
719 case LTTNG_KERNEL_KPROBE:
720 case LTTNG_KERNEL_UPROBE:
721 WRITE_ONCE(event_notifier->enabled, 0);
722 break;
723 case LTTNG_KERNEL_FUNCTION:
724 case LTTNG_KERNEL_NOOP:
725 case LTTNG_KERNEL_KRETPROBE:
726 default:
727 WARN_ON_ONCE(1);
728 ret = -EINVAL;
729 }
730 end:
731 mutex_unlock(&sessions_mutex);
732 return ret;
733 }
734
735 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
736 const char *transport_name,
737 void *buf_addr,
738 size_t subbuf_size, size_t num_subbuf,
739 unsigned int switch_timer_interval,
740 unsigned int read_timer_interval,
741 enum channel_type channel_type)
742 {
743 struct lttng_channel *chan;
744 struct lttng_transport *transport = NULL;
745
746 mutex_lock(&sessions_mutex);
747 if (session->been_active && channel_type != METADATA_CHANNEL)
748 goto active; /* Refuse to add channel to active session */
749 transport = lttng_transport_find(transport_name);
750 if (!transport) {
751 printk(KERN_WARNING "LTTng: transport %s not found\n",
752 transport_name);
753 goto notransport;
754 }
755 if (!try_module_get(transport->owner)) {
756 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
757 goto notransport;
758 }
759 chan = kzalloc(sizeof(struct lttng_channel), GFP_KERNEL);
760 if (!chan)
761 goto nomem;
762 chan->session = session;
763 chan->id = session->free_chan_id++;
764 chan->ops = &transport->ops;
765 /*
766 * Note: the channel creation op already writes into the packet
767 * headers. Therefore the "chan" information used as input
768 * should be already accessible.
769 */
770 chan->chan = transport->ops.channel_create(transport_name,
771 chan, buf_addr, subbuf_size, num_subbuf,
772 switch_timer_interval, read_timer_interval);
773 if (!chan->chan)
774 goto create_error;
775 chan->tstate = 1;
776 chan->enabled = 1;
777 chan->transport = transport;
778 chan->channel_type = channel_type;
779 list_add(&chan->list, &session->chan);
780 mutex_unlock(&sessions_mutex);
781 return chan;
782
783 create_error:
784 kfree(chan);
785 nomem:
786 if (transport)
787 module_put(transport->owner);
788 notransport:
789 active:
790 mutex_unlock(&sessions_mutex);
791 return NULL;
792 }
793
794 /*
795 * Only used internally at session destruction for per-cpu channels, and
796 * when metadata channel is released.
797 * Needs to be called with sessions mutex held.
798 */
799 static
800 void _lttng_channel_destroy(struct lttng_channel *chan)
801 {
802 chan->ops->channel_destroy(chan->chan);
803 module_put(chan->transport->owner);
804 list_del(&chan->list);
805 lttng_destroy_context(chan->ctx);
806 kfree(chan);
807 }
808
809 void lttng_metadata_channel_destroy(struct lttng_channel *chan)
810 {
811 BUG_ON(chan->channel_type != METADATA_CHANNEL);
812
813 /* Protect the metadata cache with the sessions_mutex. */
814 mutex_lock(&sessions_mutex);
815 _lttng_channel_destroy(chan);
816 mutex_unlock(&sessions_mutex);
817 }
818 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
819
820 static
821 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
822 {
823 stream->finalized = 1;
824 wake_up_interruptible(&stream->read_wait);
825 }
826
827
828 /*
829 * Supports event creation while tracing session is active.
830 * Needs to be called with sessions mutex held.
831 */
832 struct lttng_event *_lttng_event_create(struct lttng_channel *chan,
833 struct lttng_kernel_event *event_param,
834 void *filter,
835 const struct lttng_event_desc *event_desc,
836 enum lttng_kernel_instrumentation itype)
837 {
838 struct lttng_session *session = chan->session;
839 struct lttng_event *event;
840 const char *event_name;
841 struct hlist_head *head;
842 int ret;
843
844 if (chan->free_event_id == -1U) {
845 ret = -EMFILE;
846 goto full;
847 }
848
849 switch (itype) {
850 case LTTNG_KERNEL_TRACEPOINT:
851 event_name = event_desc->name;
852 break;
853 case LTTNG_KERNEL_KPROBE:
854 case LTTNG_KERNEL_UPROBE:
855 case LTTNG_KERNEL_KRETPROBE:
856 case LTTNG_KERNEL_NOOP:
857 case LTTNG_KERNEL_SYSCALL:
858 event_name = event_param->name;
859 break;
860 case LTTNG_KERNEL_FUNCTION: /* Fall-through. */
861 default:
862 WARN_ON_ONCE(1);
863 ret = -EINVAL;
864 goto type_error;
865 }
866
867 head = utils_borrow_hash_table_bucket(session->events_ht.table,
868 LTTNG_EVENT_HT_SIZE, event_name);
869 lttng_hlist_for_each_entry(event, head, hlist) {
870 WARN_ON_ONCE(!event->desc);
871 if (!strncmp(event->desc->name, event_name,
872 LTTNG_KERNEL_SYM_NAME_LEN - 1)
873 && chan == event->chan) {
874 ret = -EEXIST;
875 goto exist;
876 }
877 }
878
879 event = kmem_cache_zalloc(event_cache, GFP_KERNEL);
880 if (!event) {
881 ret = -ENOMEM;
882 goto cache_error;
883 }
884 event->chan = chan;
885 event->filter = filter;
886 event->id = chan->free_event_id++;
887 event->instrumentation = itype;
888 event->evtype = LTTNG_TYPE_EVENT;
889 INIT_LIST_HEAD(&event->filter_bytecode_runtime_head);
890 INIT_LIST_HEAD(&event->enablers_ref_head);
891
892 switch (itype) {
893 case LTTNG_KERNEL_TRACEPOINT:
894 /* Event will be enabled by enabler sync. */
895 event->enabled = 0;
896 event->registered = 0;
897 event->desc = lttng_event_desc_get(event_name);
898 if (!event->desc) {
899 ret = -ENOENT;
900 goto register_error;
901 }
902 /* Populate lttng_event structure before event registration. */
903 smp_wmb();
904 break;
905 case LTTNG_KERNEL_KPROBE:
906 /*
907 * Needs to be explicitly enabled after creation, since
908 * we may want to apply filters.
909 */
910 event->enabled = 0;
911 event->registered = 1;
912 /*
913 * Populate lttng_event structure before event
914 * registration.
915 */
916 smp_wmb();
917 ret = lttng_kprobes_register_event(event_name,
918 event_param->u.kprobe.symbol_name,
919 event_param->u.kprobe.offset,
920 event_param->u.kprobe.addr,
921 event);
922 if (ret) {
923 ret = -EINVAL;
924 goto register_error;
925 }
926 ret = try_module_get(event->desc->owner);
927 WARN_ON_ONCE(!ret);
928 break;
929 case LTTNG_KERNEL_KRETPROBE:
930 {
931 struct lttng_event *event_return;
932
933 /* kretprobe defines 2 events */
934 /*
935 * Needs to be explicitly enabled after creation, since
936 * we may want to apply filters.
937 */
938 event->enabled = 0;
939 event->registered = 1;
940 event_return =
941 kmem_cache_zalloc(event_cache, GFP_KERNEL);
942 if (!event_return) {
943 ret = -ENOMEM;
944 goto register_error;
945 }
946 event_return->chan = chan;
947 event_return->filter = filter;
948 event_return->id = chan->free_event_id++;
949 event_return->enabled = 0;
950 event_return->registered = 1;
951 event_return->instrumentation = itype;
952 /*
953 * Populate lttng_event structure before kretprobe registration.
954 */
955 smp_wmb();
956 ret = lttng_kretprobes_register(event_name,
957 event_param->u.kretprobe.symbol_name,
958 event_param->u.kretprobe.offset,
959 event_param->u.kretprobe.addr,
960 event, event_return);
961 if (ret) {
962 kmem_cache_free(event_cache, event_return);
963 ret = -EINVAL;
964 goto register_error;
965 }
966 /* Take 2 refs on the module: one per event. */
967 ret = try_module_get(event->desc->owner);
968 WARN_ON_ONCE(!ret);
969 ret = try_module_get(event->desc->owner);
970 WARN_ON_ONCE(!ret);
971 ret = _lttng_event_metadata_statedump(chan->session, chan,
972 event_return);
973 WARN_ON_ONCE(ret > 0);
974 if (ret) {
975 kmem_cache_free(event_cache, event_return);
976 module_put(event->desc->owner);
977 module_put(event->desc->owner);
978 goto statedump_error;
979 }
980 list_add(&event_return->list, &chan->session->events);
981 break;
982 }
983 case LTTNG_KERNEL_NOOP:
984 case LTTNG_KERNEL_SYSCALL:
985 /*
986 * Needs to be explicitly enabled after creation, since
987 * we may want to apply filters.
988 */
989 event->enabled = 0;
990 event->registered = 0;
991 event->desc = event_desc;
992 switch (event_param->u.syscall.entryexit) {
993 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
994 ret = -EINVAL;
995 goto register_error;
996 case LTTNG_KERNEL_SYSCALL_ENTRY:
997 event->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
998 break;
999 case LTTNG_KERNEL_SYSCALL_EXIT:
1000 event->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1001 break;
1002 }
1003 switch (event_param->u.syscall.abi) {
1004 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
1005 ret = -EINVAL;
1006 goto register_error;
1007 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
1008 event->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1009 break;
1010 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
1011 event->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1012 break;
1013 }
1014 if (!event->desc) {
1015 ret = -EINVAL;
1016 goto register_error;
1017 }
1018 break;
1019 case LTTNG_KERNEL_UPROBE:
1020 /*
1021 * Needs to be explicitly enabled after creation, since
1022 * we may want to apply filters.
1023 */
1024 event->enabled = 0;
1025 event->registered = 1;
1026
1027 /*
1028 * Populate lttng_event structure before event
1029 * registration.
1030 */
1031 smp_wmb();
1032
1033 ret = lttng_uprobes_register_event(event_param->name,
1034 event_param->u.uprobe.fd,
1035 event);
1036 if (ret)
1037 goto register_error;
1038 ret = try_module_get(event->desc->owner);
1039 WARN_ON_ONCE(!ret);
1040 break;
1041 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1042 default:
1043 WARN_ON_ONCE(1);
1044 ret = -EINVAL;
1045 goto register_error;
1046 }
1047 ret = _lttng_event_metadata_statedump(chan->session, chan, event);
1048 WARN_ON_ONCE(ret > 0);
1049 if (ret) {
1050 goto statedump_error;
1051 }
1052 hlist_add_head(&event->hlist, head);
1053 list_add(&event->list, &chan->session->events);
1054 return event;
1055
1056 statedump_error:
1057 /* If a statedump error occurs, events will not be readable. */
1058 register_error:
1059 kmem_cache_free(event_cache, event);
1060 cache_error:
1061 exist:
1062 type_error:
1063 full:
1064 return ERR_PTR(ret);
1065 }
1066
1067 struct lttng_event_notifier *_lttng_event_notifier_create(
1068 const struct lttng_event_desc *event_desc,
1069 uint64_t token, uint64_t error_counter_index,
1070 struct lttng_event_notifier_group *event_notifier_group,
1071 struct lttng_kernel_event_notifier *event_notifier_param,
1072 void *filter, enum lttng_kernel_instrumentation itype)
1073 {
1074 struct lttng_event_notifier *event_notifier;
1075 struct lttng_counter *error_counter;
1076 const char *event_name;
1077 struct hlist_head *head;
1078 int ret;
1079
1080 switch (itype) {
1081 case LTTNG_KERNEL_TRACEPOINT:
1082 event_name = event_desc->name;
1083 break;
1084 case LTTNG_KERNEL_KPROBE:
1085 case LTTNG_KERNEL_UPROBE:
1086 case LTTNG_KERNEL_SYSCALL:
1087 event_name = event_notifier_param->event.name;
1088 break;
1089 case LTTNG_KERNEL_KRETPROBE:
1090 case LTTNG_KERNEL_FUNCTION:
1091 case LTTNG_KERNEL_NOOP:
1092 default:
1093 WARN_ON_ONCE(1);
1094 ret = -EINVAL;
1095 goto type_error;
1096 }
1097
1098 head = utils_borrow_hash_table_bucket(event_notifier_group->event_notifiers_ht.table,
1099 LTTNG_EVENT_NOTIFIER_HT_SIZE, event_name);
1100 lttng_hlist_for_each_entry(event_notifier, head, hlist) {
1101 WARN_ON_ONCE(!event_notifier->desc);
1102 if (!strncmp(event_notifier->desc->name, event_name,
1103 LTTNG_KERNEL_SYM_NAME_LEN - 1)
1104 && event_notifier_group == event_notifier->group
1105 && token == event_notifier->user_token) {
1106 ret = -EEXIST;
1107 goto exist;
1108 }
1109 }
1110
1111 event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
1112 if (!event_notifier) {
1113 ret = -ENOMEM;
1114 goto cache_error;
1115 }
1116
1117 event_notifier->group = event_notifier_group;
1118 event_notifier->user_token = token;
1119 event_notifier->error_counter_index = error_counter_index;
1120 event_notifier->num_captures = 0;
1121 event_notifier->filter = filter;
1122 event_notifier->instrumentation = itype;
1123 event_notifier->evtype = LTTNG_TYPE_EVENT;
1124 event_notifier->send_notification = lttng_event_notifier_notification_send;
1125 INIT_LIST_HEAD(&event_notifier->filter_bytecode_runtime_head);
1126 INIT_LIST_HEAD(&event_notifier->capture_bytecode_runtime_head);
1127 INIT_LIST_HEAD(&event_notifier->enablers_ref_head);
1128
1129 switch (itype) {
1130 case LTTNG_KERNEL_TRACEPOINT:
1131 /* Event will be enabled by enabler sync. */
1132 event_notifier->enabled = 0;
1133 event_notifier->registered = 0;
1134 event_notifier->desc = lttng_event_desc_get(event_name);
1135 if (!event_notifier->desc) {
1136 ret = -ENOENT;
1137 goto register_error;
1138 }
1139 /* Populate lttng_event_notifier structure before event registration. */
1140 smp_wmb();
1141 break;
1142 case LTTNG_KERNEL_KPROBE:
1143 /*
1144 * Needs to be explicitly enabled after creation, since
1145 * we may want to apply filters.
1146 */
1147 event_notifier->enabled = 0;
1148 event_notifier->registered = 1;
1149 /*
1150 * Populate lttng_event_notifier structure before event
1151 * registration.
1152 */
1153 smp_wmb();
1154 ret = lttng_kprobes_register_event_notifier(
1155 event_notifier_param->event.u.kprobe.symbol_name,
1156 event_notifier_param->event.u.kprobe.offset,
1157 event_notifier_param->event.u.kprobe.addr,
1158 event_notifier);
1159 if (ret) {
1160 ret = -EINVAL;
1161 goto register_error;
1162 }
1163 ret = try_module_get(event_notifier->desc->owner);
1164 WARN_ON_ONCE(!ret);
1165 break;
1166 case LTTNG_KERNEL_NOOP:
1167 case LTTNG_KERNEL_SYSCALL:
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 = 0;
1174 event_notifier->desc = event_desc;
1175 switch (event_notifier_param->event.u.syscall.entryexit) {
1176 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
1177 ret = -EINVAL;
1178 goto register_error;
1179 case LTTNG_KERNEL_SYSCALL_ENTRY:
1180 event_notifier->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1181 break;
1182 case LTTNG_KERNEL_SYSCALL_EXIT:
1183 event_notifier->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1184 break;
1185 }
1186 switch (event_notifier_param->event.u.syscall.abi) {
1187 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
1188 ret = -EINVAL;
1189 goto register_error;
1190 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
1191 event_notifier->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1192 break;
1193 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
1194 event_notifier->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1195 break;
1196 }
1197
1198 if (!event_notifier->desc) {
1199 ret = -EINVAL;
1200 goto register_error;
1201 }
1202 break;
1203 case LTTNG_KERNEL_UPROBE:
1204 /*
1205 * Needs to be explicitly enabled after creation, since
1206 * we may want to apply filters.
1207 */
1208 event_notifier->enabled = 0;
1209 event_notifier->registered = 1;
1210
1211 /*
1212 * Populate lttng_event_notifier structure before
1213 * event_notifier registration.
1214 */
1215 smp_wmb();
1216
1217 ret = lttng_uprobes_register_event_notifier(
1218 event_notifier_param->event.name,
1219 event_notifier_param->event.u.uprobe.fd,
1220 event_notifier);
1221 if (ret)
1222 goto register_error;
1223 ret = try_module_get(event_notifier->desc->owner);
1224 WARN_ON_ONCE(!ret);
1225 break;
1226 case LTTNG_KERNEL_KRETPROBE:
1227 case LTTNG_KERNEL_FUNCTION:
1228 default:
1229 WARN_ON_ONCE(1);
1230 ret = -EINVAL;
1231 goto register_error;
1232 }
1233
1234 list_add(&event_notifier->list, &event_notifier_group->event_notifiers_head);
1235 hlist_add_head(&event_notifier->hlist, head);
1236
1237 /*
1238 * Clear the error counter bucket. The sessiond keeps track of which
1239 * bucket is currently in use. We trust it. The session lock
1240 * synchronizes against concurrent creation of the error
1241 * counter.
1242 */
1243 error_counter = event_notifier_group->error_counter;
1244 if (error_counter) {
1245 size_t dimension_index[1];
1246
1247 /*
1248 * Check that the index is within the boundary of the counter.
1249 */
1250 if (event_notifier->error_counter_index >= event_notifier_group->error_counter_len) {
1251 printk(KERN_INFO "LTTng: event_notifier: Error counter index out-of-bound: counter-len=%zu, index=%llu\n",
1252 event_notifier_group->error_counter_len, event_notifier->error_counter_index);
1253 ret = -EINVAL;
1254 goto register_error;
1255 }
1256
1257 dimension_index[0] = event_notifier->error_counter_index;
1258 ret = error_counter->ops->counter_clear(error_counter->counter, dimension_index);
1259 if (ret) {
1260 printk(KERN_INFO "LTTng: event_notifier: Unable to clear error counter bucket %llu\n",
1261 event_notifier->error_counter_index);
1262 goto register_error;
1263 }
1264 }
1265
1266 return event_notifier;
1267
1268 register_error:
1269 kmem_cache_free(event_notifier_cache, event_notifier);
1270 cache_error:
1271 exist:
1272 type_error:
1273 return ERR_PTR(ret);
1274 }
1275
1276 int lttng_kernel_counter_read(struct lttng_counter *counter,
1277 const size_t *dim_indexes, int32_t cpu,
1278 int64_t *val, bool *overflow, bool *underflow)
1279 {
1280 return counter->ops->counter_read(counter->counter, dim_indexes,
1281 cpu, val, overflow, underflow);
1282 }
1283
1284 int lttng_kernel_counter_aggregate(struct lttng_counter *counter,
1285 const size_t *dim_indexes, int64_t *val,
1286 bool *overflow, bool *underflow)
1287 {
1288 return counter->ops->counter_aggregate(counter->counter, dim_indexes,
1289 val, overflow, underflow);
1290 }
1291
1292 int lttng_kernel_counter_clear(struct lttng_counter *counter,
1293 const size_t *dim_indexes)
1294 {
1295 return counter->ops->counter_clear(counter->counter, dim_indexes);
1296 }
1297
1298 struct lttng_event *lttng_event_create(struct lttng_channel *chan,
1299 struct lttng_kernel_event *event_param,
1300 void *filter,
1301 const struct lttng_event_desc *event_desc,
1302 enum lttng_kernel_instrumentation itype)
1303 {
1304 struct lttng_event *event;
1305
1306 mutex_lock(&sessions_mutex);
1307 event = _lttng_event_create(chan, event_param, filter, event_desc,
1308 itype);
1309 mutex_unlock(&sessions_mutex);
1310 return event;
1311 }
1312
1313 struct lttng_event_notifier *lttng_event_notifier_create(
1314 const struct lttng_event_desc *event_desc,
1315 uint64_t id, uint64_t error_counter_index,
1316 struct lttng_event_notifier_group *event_notifier_group,
1317 struct lttng_kernel_event_notifier *event_notifier_param,
1318 void *filter, enum lttng_kernel_instrumentation itype)
1319 {
1320 struct lttng_event_notifier *event_notifier;
1321
1322 mutex_lock(&sessions_mutex);
1323 event_notifier = _lttng_event_notifier_create(event_desc, id,
1324 error_counter_index, event_notifier_group,
1325 event_notifier_param, filter, itype);
1326 mutex_unlock(&sessions_mutex);
1327 return event_notifier;
1328 }
1329
1330 /* Only used for tracepoints for now. */
1331 static
1332 void register_event(struct lttng_event *event)
1333 {
1334 const struct lttng_event_desc *desc;
1335 int ret = -EINVAL;
1336
1337 if (event->registered)
1338 return;
1339
1340 desc = event->desc;
1341 switch (event->instrumentation) {
1342 case LTTNG_KERNEL_TRACEPOINT:
1343 ret = lttng_wrapper_tracepoint_probe_register(desc->kname,
1344 desc->probe_callback,
1345 event);
1346 break;
1347 case LTTNG_KERNEL_SYSCALL:
1348 ret = lttng_syscall_filter_enable_event(event->chan, event);
1349 break;
1350 case LTTNG_KERNEL_KPROBE:
1351 case LTTNG_KERNEL_UPROBE:
1352 case LTTNG_KERNEL_KRETPROBE:
1353 case LTTNG_KERNEL_NOOP:
1354 ret = 0;
1355 break;
1356 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1357 default:
1358 WARN_ON_ONCE(1);
1359 }
1360 if (!ret)
1361 event->registered = 1;
1362 }
1363
1364 /*
1365 * Only used internally at session destruction.
1366 */
1367 int _lttng_event_unregister(struct lttng_event *event)
1368 {
1369 const struct lttng_event_desc *desc;
1370 int ret = -EINVAL;
1371
1372 if (!event->registered)
1373 return 0;
1374
1375 desc = event->desc;
1376 switch (event->instrumentation) {
1377 case LTTNG_KERNEL_TRACEPOINT:
1378 ret = lttng_wrapper_tracepoint_probe_unregister(event->desc->kname,
1379 event->desc->probe_callback,
1380 event);
1381 break;
1382 case LTTNG_KERNEL_KPROBE:
1383 lttng_kprobes_unregister_event(event);
1384 ret = 0;
1385 break;
1386 case LTTNG_KERNEL_KRETPROBE:
1387 lttng_kretprobes_unregister(event);
1388 ret = 0;
1389 break;
1390 case LTTNG_KERNEL_SYSCALL:
1391 ret = lttng_syscall_filter_disable_event(event->chan, event);
1392 break;
1393 case LTTNG_KERNEL_NOOP:
1394 ret = 0;
1395 break;
1396 case LTTNG_KERNEL_UPROBE:
1397 lttng_uprobes_unregister_event(event);
1398 ret = 0;
1399 break;
1400 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1401 default:
1402 WARN_ON_ONCE(1);
1403 }
1404 if (!ret)
1405 event->registered = 0;
1406 return ret;
1407 }
1408
1409 /* Only used for tracepoints for now. */
1410 static
1411 void register_event_notifier(struct lttng_event_notifier *event_notifier)
1412 {
1413 const struct lttng_event_desc *desc;
1414 int ret = -EINVAL;
1415
1416 if (event_notifier->registered)
1417 return;
1418
1419 desc = event_notifier->desc;
1420 switch (event_notifier->instrumentation) {
1421 case LTTNG_KERNEL_TRACEPOINT:
1422 ret = lttng_wrapper_tracepoint_probe_register(desc->kname,
1423 desc->event_notifier_callback,
1424 event_notifier);
1425 break;
1426 case LTTNG_KERNEL_SYSCALL:
1427 ret = lttng_syscall_filter_enable_event_notifier(event_notifier);
1428 break;
1429 case LTTNG_KERNEL_KPROBE:
1430 case LTTNG_KERNEL_UPROBE:
1431 ret = 0;
1432 break;
1433 case LTTNG_KERNEL_KRETPROBE:
1434 case LTTNG_KERNEL_FUNCTION:
1435 case LTTNG_KERNEL_NOOP:
1436 default:
1437 WARN_ON_ONCE(1);
1438 }
1439 if (!ret)
1440 event_notifier->registered = 1;
1441 }
1442
1443 static
1444 int _lttng_event_notifier_unregister(
1445 struct lttng_event_notifier *event_notifier)
1446 {
1447 const struct lttng_event_desc *desc;
1448 int ret = -EINVAL;
1449
1450 if (!event_notifier->registered)
1451 return 0;
1452
1453 desc = event_notifier->desc;
1454 switch (event_notifier->instrumentation) {
1455 case LTTNG_KERNEL_TRACEPOINT:
1456 ret = lttng_wrapper_tracepoint_probe_unregister(event_notifier->desc->kname,
1457 event_notifier->desc->event_notifier_callback,
1458 event_notifier);
1459 break;
1460 case LTTNG_KERNEL_KPROBE:
1461 lttng_kprobes_unregister_event_notifier(event_notifier);
1462 ret = 0;
1463 break;
1464 case LTTNG_KERNEL_UPROBE:
1465 lttng_uprobes_unregister_event_notifier(event_notifier);
1466 ret = 0;
1467 break;
1468 case LTTNG_KERNEL_SYSCALL:
1469 ret = lttng_syscall_filter_disable_event_notifier(event_notifier);
1470 break;
1471 case LTTNG_KERNEL_KRETPROBE:
1472 case LTTNG_KERNEL_FUNCTION:
1473 case LTTNG_KERNEL_NOOP:
1474 default:
1475 WARN_ON_ONCE(1);
1476 }
1477 if (!ret)
1478 event_notifier->registered = 0;
1479 return ret;
1480 }
1481
1482 /*
1483 * Only used internally at session destruction.
1484 */
1485 static
1486 void _lttng_event_destroy(struct lttng_event *event)
1487 {
1488 switch (event->instrumentation) {
1489 case LTTNG_KERNEL_TRACEPOINT:
1490 lttng_event_desc_put(event->desc);
1491 break;
1492 case LTTNG_KERNEL_KPROBE:
1493 module_put(event->desc->owner);
1494 lttng_kprobes_destroy_event_private(event);
1495 break;
1496 case LTTNG_KERNEL_KRETPROBE:
1497 module_put(event->desc->owner);
1498 lttng_kretprobes_destroy_private(event);
1499 break;
1500 case LTTNG_KERNEL_NOOP:
1501 case LTTNG_KERNEL_SYSCALL:
1502 break;
1503 case LTTNG_KERNEL_UPROBE:
1504 module_put(event->desc->owner);
1505 lttng_uprobes_destroy_event_private(event);
1506 break;
1507 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1508 default:
1509 WARN_ON_ONCE(1);
1510 }
1511 list_del(&event->list);
1512 lttng_destroy_context(event->ctx);
1513 kmem_cache_free(event_cache, event);
1514 }
1515
1516 /*
1517 * Only used internally at session destruction.
1518 */
1519 static
1520 void _lttng_event_notifier_destroy(struct lttng_event_notifier *event_notifier)
1521 {
1522 switch (event_notifier->instrumentation) {
1523 case LTTNG_KERNEL_TRACEPOINT:
1524 lttng_event_desc_put(event_notifier->desc);
1525 break;
1526 case LTTNG_KERNEL_KPROBE:
1527 module_put(event_notifier->desc->owner);
1528 lttng_kprobes_destroy_event_notifier_private(event_notifier);
1529 break;
1530 case LTTNG_KERNEL_NOOP:
1531 case LTTNG_KERNEL_SYSCALL:
1532 break;
1533 case LTTNG_KERNEL_UPROBE:
1534 module_put(event_notifier->desc->owner);
1535 lttng_uprobes_destroy_event_notifier_private(event_notifier);
1536 break;
1537 case LTTNG_KERNEL_KRETPROBE:
1538 case LTTNG_KERNEL_FUNCTION:
1539 default:
1540 WARN_ON_ONCE(1);
1541 }
1542 list_del(&event_notifier->list);
1543 kmem_cache_free(event_notifier_cache, event_notifier);
1544 }
1545
1546 struct lttng_id_tracker *get_tracker(struct lttng_session *session,
1547 enum tracker_type tracker_type)
1548 {
1549 switch (tracker_type) {
1550 case TRACKER_PID:
1551 return &session->pid_tracker;
1552 case TRACKER_VPID:
1553 return &session->vpid_tracker;
1554 case TRACKER_UID:
1555 return &session->uid_tracker;
1556 case TRACKER_VUID:
1557 return &session->vuid_tracker;
1558 case TRACKER_GID:
1559 return &session->gid_tracker;
1560 case TRACKER_VGID:
1561 return &session->vgid_tracker;
1562 default:
1563 WARN_ON_ONCE(1);
1564 return NULL;
1565 }
1566 }
1567
1568 int lttng_session_track_id(struct lttng_session *session,
1569 enum tracker_type tracker_type, int id)
1570 {
1571 struct lttng_id_tracker *tracker;
1572 int ret;
1573
1574 tracker = get_tracker(session, tracker_type);
1575 if (!tracker)
1576 return -EINVAL;
1577 if (id < -1)
1578 return -EINVAL;
1579 mutex_lock(&sessions_mutex);
1580 if (id == -1) {
1581 /* track all ids: destroy tracker. */
1582 lttng_id_tracker_destroy(tracker, true);
1583 ret = 0;
1584 } else {
1585 ret = lttng_id_tracker_add(tracker, id);
1586 }
1587 mutex_unlock(&sessions_mutex);
1588 return ret;
1589 }
1590
1591 int lttng_session_untrack_id(struct lttng_session *session,
1592 enum tracker_type tracker_type, int id)
1593 {
1594 struct lttng_id_tracker *tracker;
1595 int ret;
1596
1597 tracker = get_tracker(session, tracker_type);
1598 if (!tracker)
1599 return -EINVAL;
1600 if (id < -1)
1601 return -EINVAL;
1602 mutex_lock(&sessions_mutex);
1603 if (id == -1) {
1604 /* untrack all ids: replace by empty tracker. */
1605 ret = lttng_id_tracker_empty_set(tracker);
1606 } else {
1607 ret = lttng_id_tracker_del(tracker, id);
1608 }
1609 mutex_unlock(&sessions_mutex);
1610 return ret;
1611 }
1612
1613 static
1614 void *id_list_start(struct seq_file *m, loff_t *pos)
1615 {
1616 struct lttng_id_tracker *id_tracker = m->private;
1617 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1618 struct lttng_id_hash_node *e;
1619 int iter = 0, i;
1620
1621 mutex_lock(&sessions_mutex);
1622 if (id_tracker_p) {
1623 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1624 struct hlist_head *head = &id_tracker_p->id_hash[i];
1625
1626 lttng_hlist_for_each_entry(e, head, hlist) {
1627 if (iter++ >= *pos)
1628 return e;
1629 }
1630 }
1631 } else {
1632 /* ID tracker disabled. */
1633 if (iter >= *pos && iter == 0) {
1634 return id_tracker_p; /* empty tracker */
1635 }
1636 iter++;
1637 }
1638 /* End of list */
1639 return NULL;
1640 }
1641
1642 /* Called with sessions_mutex held. */
1643 static
1644 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1645 {
1646 struct lttng_id_tracker *id_tracker = m->private;
1647 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1648 struct lttng_id_hash_node *e;
1649 int iter = 0, i;
1650
1651 (*ppos)++;
1652 if (id_tracker_p) {
1653 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1654 struct hlist_head *head = &id_tracker_p->id_hash[i];
1655
1656 lttng_hlist_for_each_entry(e, head, hlist) {
1657 if (iter++ >= *ppos)
1658 return e;
1659 }
1660 }
1661 } else {
1662 /* ID tracker disabled. */
1663 if (iter >= *ppos && iter == 0)
1664 return p; /* empty tracker */
1665 iter++;
1666 }
1667
1668 /* End of list */
1669 return NULL;
1670 }
1671
1672 static
1673 void id_list_stop(struct seq_file *m, void *p)
1674 {
1675 mutex_unlock(&sessions_mutex);
1676 }
1677
1678 static
1679 int id_list_show(struct seq_file *m, void *p)
1680 {
1681 struct lttng_id_tracker *id_tracker = m->private;
1682 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1683 int id;
1684
1685 if (p == id_tracker_p) {
1686 /* Tracker disabled. */
1687 id = -1;
1688 } else {
1689 const struct lttng_id_hash_node *e = p;
1690
1691 id = lttng_id_tracker_get_node_id(e);
1692 }
1693 switch (id_tracker->tracker_type) {
1694 case TRACKER_PID:
1695 seq_printf(m, "process { pid = %d; };\n", id);
1696 break;
1697 case TRACKER_VPID:
1698 seq_printf(m, "process { vpid = %d; };\n", id);
1699 break;
1700 case TRACKER_UID:
1701 seq_printf(m, "user { uid = %d; };\n", id);
1702 break;
1703 case TRACKER_VUID:
1704 seq_printf(m, "user { vuid = %d; };\n", id);
1705 break;
1706 case TRACKER_GID:
1707 seq_printf(m, "group { gid = %d; };\n", id);
1708 break;
1709 case TRACKER_VGID:
1710 seq_printf(m, "group { vgid = %d; };\n", id);
1711 break;
1712 default:
1713 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1714 }
1715 return 0;
1716 }
1717
1718 static
1719 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1720 .start = id_list_start,
1721 .next = id_list_next,
1722 .stop = id_list_stop,
1723 .show = id_list_show,
1724 };
1725
1726 static
1727 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1728 {
1729 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1730 }
1731
1732 static
1733 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1734 {
1735 struct seq_file *m = file->private_data;
1736 struct lttng_id_tracker *id_tracker = m->private;
1737 int ret;
1738
1739 WARN_ON_ONCE(!id_tracker);
1740 ret = seq_release(inode, file);
1741 if (!ret)
1742 fput(id_tracker->session->file);
1743 return ret;
1744 }
1745
1746 const struct file_operations lttng_tracker_ids_list_fops = {
1747 .owner = THIS_MODULE,
1748 .open = lttng_tracker_ids_list_open,
1749 .read = seq_read,
1750 .llseek = seq_lseek,
1751 .release = lttng_tracker_ids_list_release,
1752 };
1753
1754 int lttng_session_list_tracker_ids(struct lttng_session *session,
1755 enum tracker_type tracker_type)
1756 {
1757 struct file *tracker_ids_list_file;
1758 struct seq_file *m;
1759 int file_fd, ret;
1760
1761 file_fd = lttng_get_unused_fd();
1762 if (file_fd < 0) {
1763 ret = file_fd;
1764 goto fd_error;
1765 }
1766
1767 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1768 &lttng_tracker_ids_list_fops,
1769 NULL, O_RDWR);
1770 if (IS_ERR(tracker_ids_list_file)) {
1771 ret = PTR_ERR(tracker_ids_list_file);
1772 goto file_error;
1773 }
1774 if (!atomic_long_add_unless(&session->file->f_count, 1, LONG_MAX)) {
1775 ret = -EOVERFLOW;
1776 goto refcount_error;
1777 }
1778 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1779 if (ret < 0)
1780 goto open_error;
1781 m = tracker_ids_list_file->private_data;
1782
1783 m->private = get_tracker(session, tracker_type);
1784 BUG_ON(!m->private);
1785 fd_install(file_fd, tracker_ids_list_file);
1786
1787 return file_fd;
1788
1789 open_error:
1790 atomic_long_dec(&session->file->f_count);
1791 refcount_error:
1792 fput(tracker_ids_list_file);
1793 file_error:
1794 put_unused_fd(file_fd);
1795 fd_error:
1796 return ret;
1797 }
1798
1799 /*
1800 * Enabler management.
1801 */
1802 static
1803 int lttng_match_enabler_star_glob(const char *desc_name,
1804 const char *pattern)
1805 {
1806 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1807 desc_name, LTTNG_SIZE_MAX))
1808 return 0;
1809 return 1;
1810 }
1811
1812 static
1813 int lttng_match_enabler_name(const char *desc_name,
1814 const char *name)
1815 {
1816 if (strcmp(desc_name, name))
1817 return 0;
1818 return 1;
1819 }
1820
1821 int lttng_desc_match_enabler(const struct lttng_event_desc *desc,
1822 struct lttng_enabler *enabler)
1823 {
1824 const char *desc_name, *enabler_name;
1825 bool compat = false, entry = false;
1826
1827 enabler_name = enabler->event_param.name;
1828 switch (enabler->event_param.instrumentation) {
1829 case LTTNG_KERNEL_TRACEPOINT:
1830 desc_name = desc->name;
1831 switch (enabler->format_type) {
1832 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1833 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1834 case LTTNG_ENABLER_FORMAT_NAME:
1835 return lttng_match_enabler_name(desc_name, enabler_name);
1836 default:
1837 return -EINVAL;
1838 }
1839 break;
1840 case LTTNG_KERNEL_SYSCALL:
1841 desc_name = desc->name;
1842 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
1843 desc_name += strlen("compat_");
1844 compat = true;
1845 }
1846 if (!strncmp(desc_name, "syscall_exit_",
1847 strlen("syscall_exit_"))) {
1848 desc_name += strlen("syscall_exit_");
1849 } else if (!strncmp(desc_name, "syscall_entry_",
1850 strlen("syscall_entry_"))) {
1851 desc_name += strlen("syscall_entry_");
1852 entry = true;
1853 } else {
1854 WARN_ON_ONCE(1);
1855 return -EINVAL;
1856 }
1857 switch (enabler->event_param.u.syscall.entryexit) {
1858 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
1859 break;
1860 case LTTNG_KERNEL_SYSCALL_ENTRY:
1861 if (!entry)
1862 return 0;
1863 break;
1864 case LTTNG_KERNEL_SYSCALL_EXIT:
1865 if (entry)
1866 return 0;
1867 break;
1868 default:
1869 return -EINVAL;
1870 }
1871 switch (enabler->event_param.u.syscall.abi) {
1872 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
1873 break;
1874 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
1875 if (compat)
1876 return 0;
1877 break;
1878 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
1879 if (!compat)
1880 return 0;
1881 break;
1882 default:
1883 return -EINVAL;
1884 }
1885 switch (enabler->event_param.u.syscall.match) {
1886 case LTTNG_KERNEL_SYSCALL_MATCH_NAME:
1887 switch (enabler->format_type) {
1888 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1889 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1890 case LTTNG_ENABLER_FORMAT_NAME:
1891 return lttng_match_enabler_name(desc_name, enabler_name);
1892 default:
1893 return -EINVAL;
1894 }
1895 break;
1896 case LTTNG_KERNEL_SYSCALL_MATCH_NR:
1897 return -EINVAL; /* Not implemented. */
1898 default:
1899 return -EINVAL;
1900 }
1901 break;
1902 default:
1903 WARN_ON_ONCE(1);
1904 return -EINVAL;
1905 }
1906 }
1907
1908 static
1909 int lttng_event_enabler_match_event(struct lttng_event_enabler *event_enabler,
1910 struct lttng_event *event)
1911 {
1912 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(
1913 event_enabler);
1914
1915 if (base_enabler->event_param.instrumentation != event->instrumentation)
1916 return 0;
1917 if (lttng_desc_match_enabler(event->desc, base_enabler)
1918 && event->chan == event_enabler->chan)
1919 return 1;
1920 else
1921 return 0;
1922 }
1923
1924 static
1925 int lttng_event_notifier_enabler_match_event_notifier(struct lttng_event_notifier_enabler *event_notifier_enabler,
1926 struct lttng_event_notifier *event_notifier)
1927 {
1928 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(
1929 event_notifier_enabler);
1930
1931 if (base_enabler->event_param.instrumentation != event_notifier->instrumentation)
1932 return 0;
1933 if (lttng_desc_match_enabler(event_notifier->desc, base_enabler)
1934 && event_notifier->group == event_notifier_enabler->group
1935 && event_notifier->user_token == event_notifier_enabler->base.user_token)
1936 return 1;
1937 else
1938 return 0;
1939 }
1940
1941 static
1942 struct lttng_enabler_ref *lttng_enabler_ref(
1943 struct list_head *enablers_ref_list,
1944 struct lttng_enabler *enabler)
1945 {
1946 struct lttng_enabler_ref *enabler_ref;
1947
1948 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
1949 if (enabler_ref->ref == enabler)
1950 return enabler_ref;
1951 }
1952 return NULL;
1953 }
1954
1955 static
1956 void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler *event_enabler)
1957 {
1958 struct lttng_session *session = event_enabler->chan->session;
1959 struct lttng_probe_desc *probe_desc;
1960 const struct lttng_event_desc *desc;
1961 int i;
1962 struct list_head *probe_list;
1963
1964 probe_list = lttng_get_probe_list_head();
1965 /*
1966 * For each probe event, if we find that a probe event matches
1967 * our enabler, create an associated lttng_event if not
1968 * already present.
1969 */
1970 list_for_each_entry(probe_desc, probe_list, head) {
1971 for (i = 0; i < probe_desc->nr_events; i++) {
1972 int found = 0;
1973 struct hlist_head *head;
1974 struct lttng_event *event;
1975
1976 desc = probe_desc->event_desc[i];
1977 if (!lttng_desc_match_enabler(desc,
1978 lttng_event_enabler_as_enabler(event_enabler)))
1979 continue;
1980
1981 /*
1982 * Check if already created.
1983 */
1984 head = utils_borrow_hash_table_bucket(
1985 session->events_ht.table, LTTNG_EVENT_HT_SIZE,
1986 desc->name);
1987 lttng_hlist_for_each_entry(event, head, hlist) {
1988 if (event->desc == desc
1989 && event->chan == event_enabler->chan)
1990 found = 1;
1991 }
1992 if (found)
1993 continue;
1994
1995 /*
1996 * We need to create an event for this
1997 * event probe.
1998 */
1999 event = _lttng_event_create(event_enabler->chan,
2000 NULL, NULL, desc,
2001 LTTNG_KERNEL_TRACEPOINT);
2002 if (!event) {
2003 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2004 probe_desc->event_desc[i]->name);
2005 }
2006 }
2007 }
2008 }
2009
2010 static
2011 void lttng_create_tracepoint_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2012 {
2013 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2014 struct lttng_probe_desc *probe_desc;
2015 const struct lttng_event_desc *desc;
2016 int i;
2017 struct list_head *probe_list;
2018
2019 probe_list = lttng_get_probe_list_head();
2020 /*
2021 * For each probe event, if we find that a probe event matches
2022 * our enabler, create an associated lttng_event_notifier if not
2023 * already present.
2024 */
2025 list_for_each_entry(probe_desc, probe_list, head) {
2026 for (i = 0; i < probe_desc->nr_events; i++) {
2027 int found = 0;
2028 struct hlist_head *head;
2029 struct lttng_event_notifier *event_notifier;
2030
2031 desc = probe_desc->event_desc[i];
2032 if (!lttng_desc_match_enabler(desc,
2033 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)))
2034 continue;
2035
2036 /*
2037 * Check if already created.
2038 */
2039 head = utils_borrow_hash_table_bucket(
2040 event_notifier_group->event_notifiers_ht.table,
2041 LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->name);
2042 lttng_hlist_for_each_entry(event_notifier, head, hlist) {
2043 if (event_notifier->desc == desc
2044 && event_notifier->user_token == event_notifier_enabler->base.user_token)
2045 found = 1;
2046 }
2047 if (found)
2048 continue;
2049
2050 /*
2051 * We need to create a event_notifier for this event probe.
2052 */
2053 event_notifier = _lttng_event_notifier_create(desc,
2054 event_notifier_enabler->base.user_token,
2055 event_notifier_enabler->error_counter_index,
2056 event_notifier_group, NULL, NULL,
2057 LTTNG_KERNEL_TRACEPOINT);
2058 if (IS_ERR(event_notifier)) {
2059 printk(KERN_INFO "Unable to create event_notifier %s\n",
2060 probe_desc->event_desc[i]->name);
2061 }
2062 }
2063 }
2064 }
2065
2066 static
2067 void lttng_create_syscall_event_if_missing(struct lttng_event_enabler *event_enabler)
2068 {
2069 int ret;
2070
2071 ret = lttng_syscalls_register_event(event_enabler, NULL);
2072 WARN_ON_ONCE(ret);
2073 }
2074
2075 static
2076 void lttng_create_syscall_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2077 {
2078 int ret;
2079
2080 ret = lttng_syscalls_register_event_notifier(event_notifier_enabler, NULL);
2081 WARN_ON_ONCE(ret);
2082 ret = lttng_syscals_create_matching_event_notifiers(event_notifier_enabler, NULL);
2083 WARN_ON_ONCE(ret);
2084 }
2085
2086 /*
2087 * Create struct lttng_event if it is missing and present in the list of
2088 * tracepoint probes.
2089 * Should be called with sessions mutex held.
2090 */
2091 static
2092 void lttng_create_event_if_missing(struct lttng_event_enabler *event_enabler)
2093 {
2094 switch (event_enabler->base.event_param.instrumentation) {
2095 case LTTNG_KERNEL_TRACEPOINT:
2096 lttng_create_tracepoint_event_if_missing(event_enabler);
2097 break;
2098 case LTTNG_KERNEL_SYSCALL:
2099 lttng_create_syscall_event_if_missing(event_enabler);
2100 break;
2101 default:
2102 WARN_ON_ONCE(1);
2103 break;
2104 }
2105 }
2106
2107 /*
2108 * Create events associated with an event_enabler (if not already present),
2109 * and add backward reference from the event to the enabler.
2110 * Should be called with sessions mutex held.
2111 */
2112 static
2113 int lttng_event_enabler_ref_events(struct lttng_event_enabler *event_enabler)
2114 {
2115 struct lttng_channel *chan = event_enabler->chan;
2116 struct lttng_session *session = event_enabler->chan->session;
2117 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(event_enabler);
2118 struct lttng_event *event;
2119
2120 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_SYSCALL &&
2121 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_SYSCALL_ABI_ALL &&
2122 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_SYSCALL_MATCH_NAME &&
2123 !strcmp(base_enabler->event_param.name, "*")) {
2124 int enabled = base_enabler->enabled;
2125 enum lttng_kernel_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2126
2127 if (entryexit == LTTNG_KERNEL_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2128 WRITE_ONCE(chan->syscall_all_entry, enabled);
2129
2130 if (entryexit == LTTNG_KERNEL_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2131 WRITE_ONCE(chan->syscall_all_exit, enabled);
2132 }
2133
2134 /* First ensure that probe events are created for this enabler. */
2135 lttng_create_event_if_missing(event_enabler);
2136
2137 /* For each event matching event_enabler in session event list. */
2138 list_for_each_entry(event, &session->events, list) {
2139 struct lttng_enabler_ref *enabler_ref;
2140
2141 if (!lttng_event_enabler_match_event(event_enabler, event))
2142 continue;
2143 enabler_ref = lttng_enabler_ref(&event->enablers_ref_head,
2144 lttng_event_enabler_as_enabler(event_enabler));
2145 if (!enabler_ref) {
2146 /*
2147 * If no backward ref, create it.
2148 * Add backward ref from event to event_enabler.
2149 */
2150 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2151 if (!enabler_ref)
2152 return -ENOMEM;
2153 enabler_ref->ref = lttng_event_enabler_as_enabler(event_enabler);
2154 list_add(&enabler_ref->node,
2155 &event->enablers_ref_head);
2156 }
2157
2158 /*
2159 * Link filter bytecodes if not linked yet.
2160 */
2161 lttng_enabler_link_bytecode(event->desc,
2162 lttng_static_ctx,
2163 &event->filter_bytecode_runtime_head,
2164 &lttng_event_enabler_as_enabler(event_enabler)->filter_bytecode_head);
2165
2166 /* TODO: merge event context. */
2167 }
2168 return 0;
2169 }
2170
2171 /*
2172 * Create struct lttng_event_notifier if it is missing and present in the list of
2173 * tracepoint probes.
2174 * Should be called with sessions mutex held.
2175 */
2176 static
2177 void lttng_create_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2178 {
2179 switch (event_notifier_enabler->base.event_param.instrumentation) {
2180 case LTTNG_KERNEL_TRACEPOINT:
2181 lttng_create_tracepoint_event_notifier_if_missing(event_notifier_enabler);
2182 break;
2183 case LTTNG_KERNEL_SYSCALL:
2184 lttng_create_syscall_event_notifier_if_missing(event_notifier_enabler);
2185 break;
2186 default:
2187 WARN_ON_ONCE(1);
2188 break;
2189 }
2190 }
2191
2192 /*
2193 * Create event_notifiers associated with a event_notifier enabler (if not already present).
2194 */
2195 static
2196 int lttng_event_notifier_enabler_ref_event_notifiers(
2197 struct lttng_event_notifier_enabler *event_notifier_enabler)
2198 {
2199 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2200 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2201 struct lttng_event_notifier *event_notifier;
2202
2203 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_SYSCALL &&
2204 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_SYSCALL_ABI_ALL &&
2205 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_SYSCALL_MATCH_NAME &&
2206 !strcmp(base_enabler->event_param.name, "*")) {
2207
2208 int enabled = base_enabler->enabled;
2209 enum lttng_kernel_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2210
2211 if (entryexit == LTTNG_KERNEL_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2212 WRITE_ONCE(event_notifier_group->syscall_all_entry, enabled);
2213
2214 if (entryexit == LTTNG_KERNEL_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2215 WRITE_ONCE(event_notifier_group->syscall_all_exit, enabled);
2216
2217 }
2218
2219 /* First ensure that probe event_notifiers are created for this enabler. */
2220 lttng_create_event_notifier_if_missing(event_notifier_enabler);
2221
2222 /* Link the created event_notifier with its associated enabler. */
2223 list_for_each_entry(event_notifier, &event_notifier_group->event_notifiers_head, list) {
2224 struct lttng_enabler_ref *enabler_ref;
2225
2226 if (!lttng_event_notifier_enabler_match_event_notifier(event_notifier_enabler, event_notifier))
2227 continue;
2228
2229 enabler_ref = lttng_enabler_ref(&event_notifier->enablers_ref_head,
2230 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2231 if (!enabler_ref) {
2232 /*
2233 * If no backward ref, create it.
2234 * Add backward ref from event_notifier to enabler.
2235 */
2236 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2237 if (!enabler_ref)
2238 return -ENOMEM;
2239
2240 enabler_ref->ref = lttng_event_notifier_enabler_as_enabler(
2241 event_notifier_enabler);
2242 list_add(&enabler_ref->node,
2243 &event_notifier->enablers_ref_head);
2244 }
2245
2246 /*
2247 * Link filter bytecodes if not linked yet.
2248 */
2249 lttng_enabler_link_bytecode(event_notifier->desc,
2250 lttng_static_ctx, &event_notifier->filter_bytecode_runtime_head,
2251 &lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->filter_bytecode_head);
2252
2253 /* Link capture bytecodes if not linked yet. */
2254 lttng_enabler_link_bytecode(event_notifier->desc,
2255 lttng_static_ctx, &event_notifier->capture_bytecode_runtime_head,
2256 &event_notifier_enabler->capture_bytecode_head);
2257
2258 event_notifier->num_captures = event_notifier_enabler->num_captures;
2259 }
2260 return 0;
2261 }
2262
2263 /*
2264 * Called at module load: connect the probe on all enablers matching
2265 * this event.
2266 * Called with sessions lock held.
2267 */
2268 int lttng_fix_pending_events(void)
2269 {
2270 struct lttng_session *session;
2271
2272 list_for_each_entry(session, &sessions, list)
2273 lttng_session_lazy_sync_event_enablers(session);
2274 return 0;
2275 }
2276
2277 static bool lttng_event_notifier_group_has_active_event_notifiers(
2278 struct lttng_event_notifier_group *event_notifier_group)
2279 {
2280 struct lttng_event_notifier_enabler *event_notifier_enabler;
2281
2282 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head,
2283 node) {
2284 if (event_notifier_enabler->base.enabled)
2285 return true;
2286 }
2287 return false;
2288 }
2289
2290 bool lttng_event_notifier_active(void)
2291 {
2292 struct lttng_event_notifier_group *event_notifier_group;
2293
2294 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2295 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2296 return true;
2297 }
2298 return false;
2299 }
2300
2301 int lttng_fix_pending_event_notifiers(void)
2302 {
2303 struct lttng_event_notifier_group *event_notifier_group;
2304
2305 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2306 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2307 return 0;
2308 }
2309
2310 struct lttng_event_enabler *lttng_event_enabler_create(
2311 enum lttng_enabler_format_type format_type,
2312 struct lttng_kernel_event *event_param,
2313 struct lttng_channel *chan)
2314 {
2315 struct lttng_event_enabler *event_enabler;
2316
2317 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2318 if (!event_enabler)
2319 return NULL;
2320 event_enabler->base.format_type = format_type;
2321 INIT_LIST_HEAD(&event_enabler->base.filter_bytecode_head);
2322 memcpy(&event_enabler->base.event_param, event_param,
2323 sizeof(event_enabler->base.event_param));
2324 event_enabler->chan = chan;
2325 /* ctx left NULL */
2326 event_enabler->base.enabled = 0;
2327 event_enabler->base.evtype = LTTNG_TYPE_ENABLER;
2328 mutex_lock(&sessions_mutex);
2329 list_add(&event_enabler->node, &event_enabler->chan->session->enablers_head);
2330 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2331 mutex_unlock(&sessions_mutex);
2332 return event_enabler;
2333 }
2334
2335 int lttng_event_enabler_enable(struct lttng_event_enabler *event_enabler)
2336 {
2337 mutex_lock(&sessions_mutex);
2338 lttng_event_enabler_as_enabler(event_enabler)->enabled = 1;
2339 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2340 mutex_unlock(&sessions_mutex);
2341 return 0;
2342 }
2343
2344 int lttng_event_enabler_disable(struct lttng_event_enabler *event_enabler)
2345 {
2346 mutex_lock(&sessions_mutex);
2347 lttng_event_enabler_as_enabler(event_enabler)->enabled = 0;
2348 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2349 mutex_unlock(&sessions_mutex);
2350 return 0;
2351 }
2352
2353 static
2354 int lttng_enabler_attach_filter_bytecode(struct lttng_enabler *enabler,
2355 struct lttng_kernel_filter_bytecode __user *bytecode)
2356 {
2357 struct lttng_bytecode_node *bytecode_node;
2358 uint32_t bytecode_len;
2359 int ret;
2360
2361 ret = get_user(bytecode_len, &bytecode->len);
2362 if (ret)
2363 return ret;
2364 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2365 GFP_KERNEL);
2366 if (!bytecode_node)
2367 return -ENOMEM;
2368 ret = copy_from_user(&bytecode_node->bc, bytecode,
2369 sizeof(*bytecode) + bytecode_len);
2370 if (ret)
2371 goto error_free;
2372
2373 bytecode_node->type = LTTNG_BYTECODE_NODE_TYPE_FILTER;
2374 bytecode_node->enabler = enabler;
2375 /* Enforce length based on allocated size */
2376 bytecode_node->bc.len = bytecode_len;
2377 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2378
2379 return 0;
2380
2381 error_free:
2382 lttng_kvfree(bytecode_node);
2383 return ret;
2384 }
2385
2386 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler *event_enabler,
2387 struct lttng_kernel_filter_bytecode __user *bytecode)
2388 {
2389 int ret;
2390 ret = lttng_enabler_attach_filter_bytecode(
2391 lttng_event_enabler_as_enabler(event_enabler), bytecode);
2392 if (ret)
2393 goto error;
2394
2395 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2396 return 0;
2397
2398 error:
2399 return ret;
2400 }
2401
2402 int lttng_event_add_callsite(struct lttng_event *event,
2403 struct lttng_kernel_event_callsite __user *callsite)
2404 {
2405
2406 switch (event->instrumentation) {
2407 case LTTNG_KERNEL_UPROBE:
2408 return lttng_uprobes_event_add_callsite(event, callsite);
2409 default:
2410 return -EINVAL;
2411 }
2412 }
2413
2414 int lttng_event_enabler_attach_context(struct lttng_event_enabler *event_enabler,
2415 struct lttng_kernel_context *context_param)
2416 {
2417 return -ENOSYS;
2418 }
2419
2420 static
2421 void lttng_enabler_destroy(struct lttng_enabler *enabler)
2422 {
2423 struct lttng_bytecode_node *filter_node, *tmp_filter_node;
2424
2425 /* Destroy filter bytecode */
2426 list_for_each_entry_safe(filter_node, tmp_filter_node,
2427 &enabler->filter_bytecode_head, node) {
2428 lttng_kvfree(filter_node);
2429 }
2430 }
2431
2432 static
2433 void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler)
2434 {
2435 lttng_enabler_destroy(lttng_event_enabler_as_enabler(event_enabler));
2436
2437 /* Destroy contexts */
2438 lttng_destroy_context(event_enabler->ctx);
2439
2440 list_del(&event_enabler->node);
2441 kfree(event_enabler);
2442 }
2443
2444 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2445 struct lttng_event_notifier_group *event_notifier_group,
2446 enum lttng_enabler_format_type format_type,
2447 struct lttng_kernel_event_notifier *event_notifier_param)
2448 {
2449 struct lttng_event_notifier_enabler *event_notifier_enabler;
2450
2451 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2452 if (!event_notifier_enabler)
2453 return NULL;
2454
2455 event_notifier_enabler->base.format_type = format_type;
2456 INIT_LIST_HEAD(&event_notifier_enabler->base.filter_bytecode_head);
2457 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2458
2459 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2460 event_notifier_enabler->num_captures = 0;
2461
2462 memcpy(&event_notifier_enabler->base.event_param, &event_notifier_param->event,
2463 sizeof(event_notifier_enabler->base.event_param));
2464 event_notifier_enabler->base.evtype = LTTNG_TYPE_ENABLER;
2465
2466 event_notifier_enabler->base.enabled = 0;
2467 event_notifier_enabler->base.user_token = event_notifier_param->event.token;
2468 event_notifier_enabler->group = event_notifier_group;
2469
2470 mutex_lock(&sessions_mutex);
2471 list_add(&event_notifier_enabler->node, &event_notifier_enabler->group->enablers_head);
2472 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2473
2474 mutex_unlock(&sessions_mutex);
2475
2476 return event_notifier_enabler;
2477 }
2478
2479 int lttng_event_notifier_enabler_enable(
2480 struct lttng_event_notifier_enabler *event_notifier_enabler)
2481 {
2482 mutex_lock(&sessions_mutex);
2483 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2484 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2485 mutex_unlock(&sessions_mutex);
2486 return 0;
2487 }
2488
2489 int lttng_event_notifier_enabler_disable(
2490 struct lttng_event_notifier_enabler *event_notifier_enabler)
2491 {
2492 mutex_lock(&sessions_mutex);
2493 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2494 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2495 mutex_unlock(&sessions_mutex);
2496 return 0;
2497 }
2498
2499 int lttng_event_notifier_enabler_attach_filter_bytecode(
2500 struct lttng_event_notifier_enabler *event_notifier_enabler,
2501 struct lttng_kernel_filter_bytecode __user *bytecode)
2502 {
2503 int ret;
2504
2505 ret = lttng_enabler_attach_filter_bytecode(
2506 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler),
2507 bytecode);
2508 if (ret)
2509 goto error;
2510
2511 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2512 return 0;
2513
2514 error:
2515 return ret;
2516 }
2517
2518 int lttng_event_notifier_enabler_attach_capture_bytecode(
2519 struct lttng_event_notifier_enabler *event_notifier_enabler,
2520 struct lttng_kernel_capture_bytecode __user *bytecode)
2521 {
2522 struct lttng_bytecode_node *bytecode_node;
2523 struct lttng_enabler *enabler =
2524 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2525 uint32_t bytecode_len;
2526 int ret;
2527
2528 ret = get_user(bytecode_len, &bytecode->len);
2529 if (ret)
2530 return ret;
2531
2532 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2533 GFP_KERNEL);
2534 if (!bytecode_node)
2535 return -ENOMEM;
2536
2537 ret = copy_from_user(&bytecode_node->bc, bytecode,
2538 sizeof(*bytecode) + bytecode_len);
2539 if (ret)
2540 goto error_free;
2541
2542 bytecode_node->type = LTTNG_BYTECODE_NODE_TYPE_CAPTURE;
2543 bytecode_node->enabler = enabler;
2544
2545 /* Enforce length based on allocated size */
2546 bytecode_node->bc.len = bytecode_len;
2547 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2548
2549 event_notifier_enabler->num_captures++;
2550
2551 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2552 goto end;
2553
2554 error_free:
2555 lttng_kvfree(bytecode_node);
2556 end:
2557 return ret;
2558 }
2559
2560 int lttng_event_notifier_add_callsite(struct lttng_event_notifier *event_notifier,
2561 struct lttng_kernel_event_callsite __user *callsite)
2562 {
2563
2564 switch (event_notifier->instrumentation) {
2565 case LTTNG_KERNEL_UPROBE:
2566 return lttng_uprobes_event_notifier_add_callsite(event_notifier,
2567 callsite);
2568 default:
2569 return -EINVAL;
2570 }
2571 }
2572
2573 int lttng_event_notifier_enabler_attach_context(
2574 struct lttng_event_notifier_enabler *event_notifier_enabler,
2575 struct lttng_kernel_context *context_param)
2576 {
2577 return -ENOSYS;
2578 }
2579
2580 static
2581 void lttng_event_notifier_enabler_destroy(
2582 struct lttng_event_notifier_enabler *event_notifier_enabler)
2583 {
2584 if (!event_notifier_enabler) {
2585 return;
2586 }
2587
2588 list_del(&event_notifier_enabler->node);
2589
2590 lttng_enabler_destroy(lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2591 kfree(event_notifier_enabler);
2592 }
2593
2594 /*
2595 * lttng_session_sync_event_enablers should be called just before starting a
2596 * session.
2597 * Should be called with sessions mutex held.
2598 */
2599 static
2600 void lttng_session_sync_event_enablers(struct lttng_session *session)
2601 {
2602 struct lttng_event_enabler *event_enabler;
2603 struct lttng_event *event;
2604
2605 list_for_each_entry(event_enabler, &session->enablers_head, node)
2606 lttng_event_enabler_ref_events(event_enabler);
2607 /*
2608 * For each event, if at least one of its enablers is enabled,
2609 * and its channel and session transient states are enabled, we
2610 * enable the event, else we disable it.
2611 */
2612 list_for_each_entry(event, &session->events, list) {
2613 struct lttng_enabler_ref *enabler_ref;
2614 struct lttng_bytecode_runtime *runtime;
2615 int enabled = 0, has_enablers_without_bytecode = 0;
2616
2617 switch (event->instrumentation) {
2618 case LTTNG_KERNEL_TRACEPOINT:
2619 case LTTNG_KERNEL_SYSCALL:
2620 /* Enable events */
2621 list_for_each_entry(enabler_ref,
2622 &event->enablers_ref_head, node) {
2623 if (enabler_ref->ref->enabled) {
2624 enabled = 1;
2625 break;
2626 }
2627 }
2628 break;
2629 default:
2630 /* Not handled with lazy sync. */
2631 continue;
2632 }
2633 /*
2634 * Enabled state is based on union of enablers, with
2635 * intesection of session and channel transient enable
2636 * states.
2637 */
2638 enabled = enabled && session->tstate && event->chan->tstate;
2639
2640 WRITE_ONCE(event->enabled, enabled);
2641 /*
2642 * Sync tracepoint registration with event enabled
2643 * state.
2644 */
2645 if (enabled) {
2646 register_event(event);
2647 } else {
2648 _lttng_event_unregister(event);
2649 }
2650
2651 /* Check if has enablers without bytecode enabled */
2652 list_for_each_entry(enabler_ref,
2653 &event->enablers_ref_head, node) {
2654 if (enabler_ref->ref->enabled
2655 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2656 has_enablers_without_bytecode = 1;
2657 break;
2658 }
2659 }
2660 event->has_enablers_without_bytecode =
2661 has_enablers_without_bytecode;
2662
2663 /* Enable filters */
2664 list_for_each_entry(runtime,
2665 &event->filter_bytecode_runtime_head, node)
2666 lttng_bytecode_filter_sync_state(runtime);
2667 }
2668 }
2669
2670 /*
2671 * Apply enablers to session events, adding events to session if need
2672 * be. It is required after each modification applied to an active
2673 * session, and right before session "start".
2674 * "lazy" sync means we only sync if required.
2675 * Should be called with sessions mutex held.
2676 */
2677 static
2678 void lttng_session_lazy_sync_event_enablers(struct lttng_session *session)
2679 {
2680 /* We can skip if session is not active */
2681 if (!session->active)
2682 return;
2683 lttng_session_sync_event_enablers(session);
2684 }
2685
2686 static
2687 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2688 {
2689 struct lttng_event_notifier_enabler *event_notifier_enabler;
2690 struct lttng_event_notifier *event_notifier;
2691
2692 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head, node)
2693 lttng_event_notifier_enabler_ref_event_notifiers(event_notifier_enabler);
2694
2695 /*
2696 * For each event_notifier, if at least one of its enablers is enabled,
2697 * we enable the event_notifier, else we disable it.
2698 */
2699 list_for_each_entry(event_notifier, &event_notifier_group->event_notifiers_head, list) {
2700 struct lttng_enabler_ref *enabler_ref;
2701 struct lttng_bytecode_runtime *runtime;
2702 int enabled = 0, has_enablers_without_bytecode = 0;
2703
2704 switch (event_notifier->instrumentation) {
2705 case LTTNG_KERNEL_TRACEPOINT:
2706 case LTTNG_KERNEL_SYSCALL:
2707 /* Enable event_notifiers */
2708 list_for_each_entry(enabler_ref,
2709 &event_notifier->enablers_ref_head, node) {
2710 if (enabler_ref->ref->enabled) {
2711 enabled = 1;
2712 break;
2713 }
2714 }
2715 break;
2716 default:
2717 /* Not handled with sync. */
2718 continue;
2719 }
2720
2721 WRITE_ONCE(event_notifier->enabled, enabled);
2722 /*
2723 * Sync tracepoint registration with event_notifier enabled
2724 * state.
2725 */
2726 if (enabled) {
2727 if (!event_notifier->registered)
2728 register_event_notifier(event_notifier);
2729 } else {
2730 if (event_notifier->registered)
2731 _lttng_event_notifier_unregister(event_notifier);
2732 }
2733
2734 /* Check if has enablers without bytecode enabled */
2735 list_for_each_entry(enabler_ref,
2736 &event_notifier->enablers_ref_head, node) {
2737 if (enabler_ref->ref->enabled
2738 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2739 has_enablers_without_bytecode = 1;
2740 break;
2741 }
2742 }
2743 event_notifier->has_enablers_without_bytecode =
2744 has_enablers_without_bytecode;
2745
2746 /* Enable filters */
2747 list_for_each_entry(runtime,
2748 &event_notifier->filter_bytecode_runtime_head, node)
2749 lttng_bytecode_filter_sync_state(runtime);
2750
2751 /* Enable captures */
2752 list_for_each_entry(runtime,
2753 &event_notifier->capture_bytecode_runtime_head, node)
2754 lttng_bytecode_capture_sync_state(runtime);
2755 }
2756 }
2757
2758 /*
2759 * Serialize at most one packet worth of metadata into a metadata
2760 * channel.
2761 * We grab the metadata cache mutex to get exclusive access to our metadata
2762 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2763 * allows us to do racy operations such as looking for remaining space left in
2764 * packet and write, since mutual exclusion protects us from concurrent writes.
2765 * Mutual exclusion on the metadata cache allow us to read the cache content
2766 * without racing against reallocation of the cache by updates.
2767 * Returns the number of bytes written in the channel, 0 if no data
2768 * was written and a negative value on error.
2769 */
2770 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2771 struct channel *chan, bool *coherent)
2772 {
2773 struct lib_ring_buffer_ctx ctx;
2774 int ret = 0;
2775 size_t len, reserve_len;
2776
2777 /*
2778 * Ensure we support mutiple get_next / put sequences followed by
2779 * put_next. The metadata cache lock protects reading the metadata
2780 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2781 * "flush" operations on the buffer invoked by different processes.
2782 * Moreover, since the metadata cache memory can be reallocated, we
2783 * need to have exclusive access against updates even though we only
2784 * read it.
2785 */
2786 mutex_lock(&stream->metadata_cache->lock);
2787 WARN_ON(stream->metadata_in < stream->metadata_out);
2788 if (stream->metadata_in != stream->metadata_out)
2789 goto end;
2790
2791 /* Metadata regenerated, change the version. */
2792 if (stream->metadata_cache->version != stream->version)
2793 stream->version = stream->metadata_cache->version;
2794
2795 len = stream->metadata_cache->metadata_written -
2796 stream->metadata_in;
2797 if (!len)
2798 goto end;
2799 reserve_len = min_t(size_t,
2800 stream->transport->ops.packet_avail_size(chan),
2801 len);
2802 lib_ring_buffer_ctx_init(&ctx, chan, NULL, reserve_len,
2803 sizeof(char), -1);
2804 /*
2805 * If reservation failed, return an error to the caller.
2806 */
2807 ret = stream->transport->ops.event_reserve(&ctx, 0);
2808 if (ret != 0) {
2809 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2810 stream->coherent = false;
2811 goto end;
2812 }
2813 stream->transport->ops.event_write(&ctx,
2814 stream->metadata_cache->data + stream->metadata_in,
2815 reserve_len);
2816 stream->transport->ops.event_commit(&ctx);
2817 stream->metadata_in += reserve_len;
2818 if (reserve_len < len)
2819 stream->coherent = false;
2820 else
2821 stream->coherent = true;
2822 ret = reserve_len;
2823
2824 end:
2825 if (coherent)
2826 *coherent = stream->coherent;
2827 mutex_unlock(&stream->metadata_cache->lock);
2828 return ret;
2829 }
2830
2831 static
2832 void lttng_metadata_begin(struct lttng_session *session)
2833 {
2834 if (atomic_inc_return(&session->metadata_cache->producing) == 1)
2835 mutex_lock(&session->metadata_cache->lock);
2836 }
2837
2838 static
2839 void lttng_metadata_end(struct lttng_session *session)
2840 {
2841 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
2842 if (atomic_dec_return(&session->metadata_cache->producing) == 0) {
2843 struct lttng_metadata_stream *stream;
2844
2845 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
2846 wake_up_interruptible(&stream->read_wait);
2847 mutex_unlock(&session->metadata_cache->lock);
2848 }
2849 }
2850
2851 /*
2852 * Write the metadata to the metadata cache.
2853 * Must be called with sessions_mutex held.
2854 * The metadata cache lock protects us from concurrent read access from
2855 * thread outputting metadata content to ring buffer.
2856 * The content of the printf is printed as a single atomic metadata
2857 * transaction.
2858 */
2859 int lttng_metadata_printf(struct lttng_session *session,
2860 const char *fmt, ...)
2861 {
2862 char *str;
2863 size_t len;
2864 va_list ap;
2865
2866 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
2867
2868 va_start(ap, fmt);
2869 str = kvasprintf(GFP_KERNEL, fmt, ap);
2870 va_end(ap);
2871 if (!str)
2872 return -ENOMEM;
2873
2874 len = strlen(str);
2875 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
2876 if (session->metadata_cache->metadata_written + len >
2877 session->metadata_cache->cache_alloc) {
2878 char *tmp_cache_realloc;
2879 unsigned int tmp_cache_alloc_size;
2880
2881 tmp_cache_alloc_size = max_t(unsigned int,
2882 session->metadata_cache->cache_alloc + len,
2883 session->metadata_cache->cache_alloc << 1);
2884 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
2885 if (!tmp_cache_realloc)
2886 goto err;
2887 if (session->metadata_cache->data) {
2888 memcpy(tmp_cache_realloc,
2889 session->metadata_cache->data,
2890 session->metadata_cache->cache_alloc);
2891 vfree(session->metadata_cache->data);
2892 }
2893
2894 session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
2895 session->metadata_cache->data = tmp_cache_realloc;
2896 }
2897 memcpy(session->metadata_cache->data +
2898 session->metadata_cache->metadata_written,
2899 str, len);
2900 session->metadata_cache->metadata_written += len;
2901 kfree(str);
2902
2903 return 0;
2904
2905 err:
2906 kfree(str);
2907 return -ENOMEM;
2908 }
2909
2910 static
2911 int print_tabs(struct lttng_session *session, size_t nesting)
2912 {
2913 size_t i;
2914
2915 for (i = 0; i < nesting; i++) {
2916 int ret;
2917
2918 ret = lttng_metadata_printf(session, " ");
2919 if (ret) {
2920 return ret;
2921 }
2922 }
2923 return 0;
2924 }
2925
2926 static
2927 int lttng_field_name_statedump(struct lttng_session *session,
2928 const struct lttng_event_field *field,
2929 size_t nesting)
2930 {
2931 return lttng_metadata_printf(session, " _%s;\n", field->name);
2932 }
2933
2934 static
2935 int _lttng_integer_type_statedump(struct lttng_session *session,
2936 const struct lttng_type *type,
2937 size_t nesting)
2938 {
2939 int ret;
2940
2941 WARN_ON_ONCE(type->atype != atype_integer);
2942 ret = print_tabs(session, nesting);
2943 if (ret)
2944 return ret;
2945 ret = lttng_metadata_printf(session,
2946 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
2947 type->u.integer.size,
2948 type->u.integer.alignment,
2949 type->u.integer.signedness,
2950 (type->u.integer.encoding == lttng_encode_none)
2951 ? "none"
2952 : (type->u.integer.encoding == lttng_encode_UTF8)
2953 ? "UTF8"
2954 : "ASCII",
2955 type->u.integer.base,
2956 #if __BYTE_ORDER == __BIG_ENDIAN
2957 type->u.integer.reverse_byte_order ? " byte_order = le;" : ""
2958 #else
2959 type->u.integer.reverse_byte_order ? " byte_order = be;" : ""
2960 #endif
2961 );
2962 return ret;
2963 }
2964
2965 /*
2966 * Must be called with sessions_mutex held.
2967 */
2968 static
2969 int _lttng_struct_type_statedump(struct lttng_session *session,
2970 const struct lttng_type *type,
2971 size_t nesting)
2972 {
2973 int ret;
2974 uint32_t i, nr_fields;
2975 unsigned int alignment;
2976
2977 WARN_ON_ONCE(type->atype != atype_struct_nestable);
2978
2979 ret = print_tabs(session, nesting);
2980 if (ret)
2981 return ret;
2982 ret = lttng_metadata_printf(session,
2983 "struct {\n");
2984 if (ret)
2985 return ret;
2986 nr_fields = type->u.struct_nestable.nr_fields;
2987 for (i = 0; i < nr_fields; i++) {
2988 const struct lttng_event_field *iter_field;
2989
2990 iter_field = &type->u.struct_nestable.fields[i];
2991 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
2992 if (ret)
2993 return ret;
2994 }
2995 ret = print_tabs(session, nesting);
2996 if (ret)
2997 return ret;
2998 alignment = type->u.struct_nestable.alignment;
2999 if (alignment) {
3000 ret = lttng_metadata_printf(session,
3001 "} align(%u)",
3002 alignment);
3003 } else {
3004 ret = lttng_metadata_printf(session,
3005 "}");
3006 }
3007 return ret;
3008 }
3009
3010 /*
3011 * Must be called with sessions_mutex held.
3012 */
3013 static
3014 int _lttng_struct_field_statedump(struct lttng_session *session,
3015 const struct lttng_event_field *field,
3016 size_t nesting)
3017 {
3018 int ret;
3019
3020 ret = _lttng_struct_type_statedump(session,
3021 &field->type, nesting);
3022 if (ret)
3023 return ret;
3024 return lttng_field_name_statedump(session, field, nesting);
3025 }
3026
3027 /*
3028 * Must be called with sessions_mutex held.
3029 */
3030 static
3031 int _lttng_variant_type_statedump(struct lttng_session *session,
3032 const struct lttng_type *type,
3033 size_t nesting)
3034 {
3035 int ret;
3036 uint32_t i, nr_choices;
3037
3038 WARN_ON_ONCE(type->atype != atype_variant_nestable);
3039 /*
3040 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3041 */
3042 if (type->u.variant_nestable.alignment != 0)
3043 return -EINVAL;
3044 ret = print_tabs(session, nesting);
3045 if (ret)
3046 return ret;
3047 ret = lttng_metadata_printf(session,
3048 "variant <_%s> {\n",
3049 type->u.variant_nestable.tag_name);
3050 if (ret)
3051 return ret;
3052 nr_choices = type->u.variant_nestable.nr_choices;
3053 for (i = 0; i < nr_choices; i++) {
3054 const struct lttng_event_field *iter_field;
3055
3056 iter_field = &type->u.variant_nestable.choices[i];
3057 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
3058 if (ret)
3059 return ret;
3060 }
3061 ret = print_tabs(session, nesting);
3062 if (ret)
3063 return ret;
3064 ret = lttng_metadata_printf(session,
3065 "}");
3066 return ret;
3067 }
3068
3069 /*
3070 * Must be called with sessions_mutex held.
3071 */
3072 static
3073 int _lttng_variant_field_statedump(struct lttng_session *session,
3074 const struct lttng_event_field *field,
3075 size_t nesting)
3076 {
3077 int ret;
3078
3079 ret = _lttng_variant_type_statedump(session,
3080 &field->type, nesting);
3081 if (ret)
3082 return ret;
3083 return lttng_field_name_statedump(session, field, nesting);
3084 }
3085
3086 /*
3087 * Must be called with sessions_mutex held.
3088 */
3089 static
3090 int _lttng_array_field_statedump(struct lttng_session *session,
3091 const struct lttng_event_field *field,
3092 size_t nesting)
3093 {
3094 int ret;
3095 const struct lttng_type *elem_type;
3096
3097 WARN_ON_ONCE(field->type.atype != atype_array_nestable);
3098
3099 if (field->type.u.array_nestable.alignment) {
3100 ret = print_tabs(session, nesting);
3101 if (ret)
3102 return ret;
3103 ret = lttng_metadata_printf(session,
3104 "struct { } align(%u) _%s_padding;\n",
3105 field->type.u.array_nestable.alignment * CHAR_BIT,
3106 field->name);
3107 if (ret)
3108 return ret;
3109 }
3110 /*
3111 * Nested compound types: Only array of structures and variants are
3112 * currently supported.
3113 */
3114 elem_type = field->type.u.array_nestable.elem_type;
3115 switch (elem_type->atype) {
3116 case atype_integer:
3117 case atype_struct_nestable:
3118 case atype_variant_nestable:
3119 ret = _lttng_type_statedump(session, elem_type, nesting);
3120 if (ret)
3121 return ret;
3122 break;
3123
3124 default:
3125 return -EINVAL;
3126 }
3127 ret = lttng_metadata_printf(session,
3128 " _%s[%u];\n",
3129 field->name,
3130 field->type.u.array_nestable.length);
3131 return ret;
3132 }
3133
3134 /*
3135 * Must be called with sessions_mutex held.
3136 */
3137 static
3138 int _lttng_sequence_field_statedump(struct lttng_session *session,
3139 const struct lttng_event_field *field,
3140 size_t nesting)
3141 {
3142 int ret;
3143 const char *length_name;
3144 const struct lttng_type *elem_type;
3145
3146 WARN_ON_ONCE(field->type.atype != atype_sequence_nestable);
3147
3148 length_name = field->type.u.sequence_nestable.length_name;
3149
3150 if (field->type.u.sequence_nestable.alignment) {
3151 ret = print_tabs(session, nesting);
3152 if (ret)
3153 return ret;
3154 ret = lttng_metadata_printf(session,
3155 "struct { } align(%u) _%s_padding;\n",
3156 field->type.u.sequence_nestable.alignment * CHAR_BIT,
3157 field->name);
3158 if (ret)
3159 return ret;
3160 }
3161
3162 /*
3163 * Nested compound types: Only array of structures and variants are
3164 * currently supported.
3165 */
3166 elem_type = field->type.u.sequence_nestable.elem_type;
3167 switch (elem_type->atype) {
3168 case atype_integer:
3169 case atype_struct_nestable:
3170 case atype_variant_nestable:
3171 ret = _lttng_type_statedump(session, elem_type, nesting);
3172 if (ret)
3173 return ret;
3174 break;
3175
3176 default:
3177 return -EINVAL;
3178 }
3179 ret = lttng_metadata_printf(session,
3180 " _%s[ _%s ];\n",
3181 field->name,
3182 field->type.u.sequence_nestable.length_name);
3183 return ret;
3184 }
3185
3186 /*
3187 * Must be called with sessions_mutex held.
3188 */
3189 static
3190 int _lttng_enum_type_statedump(struct lttng_session *session,
3191 const struct lttng_type *type,
3192 size_t nesting)
3193 {
3194 const struct lttng_enum_desc *enum_desc;
3195 const struct lttng_type *container_type;
3196 int ret;
3197 unsigned int i, nr_entries;
3198
3199 container_type = type->u.enum_nestable.container_type;
3200 if (container_type->atype != atype_integer) {
3201 ret = -EINVAL;
3202 goto end;
3203 }
3204 enum_desc = type->u.enum_nestable.desc;
3205 nr_entries = enum_desc->nr_entries;
3206
3207 ret = print_tabs(session, nesting);
3208 if (ret)
3209 goto end;
3210 ret = lttng_metadata_printf(session, "enum : ");
3211 if (ret)
3212 goto end;
3213 ret = _lttng_integer_type_statedump(session, container_type, 0);
3214 if (ret)
3215 goto end;
3216 ret = lttng_metadata_printf(session, " {\n");
3217 if (ret)
3218 goto end;
3219 /* Dump all entries */
3220 for (i = 0; i < nr_entries; i++) {
3221 const struct lttng_enum_entry *entry = &enum_desc->entries[i];
3222 int j, len;
3223
3224 ret = print_tabs(session, nesting + 1);
3225 if (ret)
3226 goto end;
3227 ret = lttng_metadata_printf(session,
3228 "\"");
3229 if (ret)
3230 goto end;
3231 len = strlen(entry->string);
3232 /* Escape the character '"' */
3233 for (j = 0; j < len; j++) {
3234 char c = entry->string[j];
3235
3236 switch (c) {
3237 case '"':
3238 ret = lttng_metadata_printf(session,
3239 "\\\"");
3240 break;
3241 case '\\':
3242 ret = lttng_metadata_printf(session,
3243 "\\\\");
3244 break;
3245 default:
3246 ret = lttng_metadata_printf(session,
3247 "%c", c);
3248 break;
3249 }
3250 if (ret)
3251 goto end;
3252 }
3253 ret = lttng_metadata_printf(session, "\"");
3254 if (ret)
3255 goto end;
3256
3257 if (entry->options.is_auto) {
3258 ret = lttng_metadata_printf(session, ",\n");
3259 if (ret)
3260 goto end;
3261 } else {
3262 ret = lttng_metadata_printf(session,
3263 " = ");
3264 if (ret)
3265 goto end;
3266 if (entry->start.signedness)
3267 ret = lttng_metadata_printf(session,
3268 "%lld", (long long) entry->start.value);
3269 else
3270 ret = lttng_metadata_printf(session,
3271 "%llu", entry->start.value);
3272 if (ret)
3273 goto end;
3274 if (entry->start.signedness == entry->end.signedness &&
3275 entry->start.value
3276 == entry->end.value) {
3277 ret = lttng_metadata_printf(session,
3278 ",\n");
3279 } else {
3280 if (entry->end.signedness) {
3281 ret = lttng_metadata_printf(session,
3282 " ... %lld,\n",
3283 (long long) entry->end.value);
3284 } else {
3285 ret = lttng_metadata_printf(session,
3286 " ... %llu,\n",
3287 entry->end.value);
3288 }
3289 }
3290 if (ret)
3291 goto end;
3292 }
3293 }
3294 ret = print_tabs(session, nesting);
3295 if (ret)
3296 goto end;
3297 ret = lttng_metadata_printf(session, "}");
3298 end:
3299 return ret;
3300 }
3301
3302 /*
3303 * Must be called with sessions_mutex held.
3304 */
3305 static
3306 int _lttng_enum_field_statedump(struct lttng_session *session,
3307 const struct lttng_event_field *field,
3308 size_t nesting)
3309 {
3310 int ret;
3311
3312 ret = _lttng_enum_type_statedump(session, &field->type, nesting);
3313 if (ret)
3314 return ret;
3315 return lttng_field_name_statedump(session, field, nesting);
3316 }
3317
3318 static
3319 int _lttng_integer_field_statedump(struct lttng_session *session,
3320 const struct lttng_event_field *field,
3321 size_t nesting)
3322 {
3323 int ret;
3324
3325 ret = _lttng_integer_type_statedump(session, &field->type, nesting);
3326 if (ret)
3327 return ret;
3328 return lttng_field_name_statedump(session, field, nesting);
3329 }
3330
3331 static
3332 int _lttng_string_type_statedump(struct lttng_session *session,
3333 const struct lttng_type *type,
3334 size_t nesting)
3335 {
3336 int ret;
3337
3338 WARN_ON_ONCE(type->atype != atype_string);
3339 /* Default encoding is UTF8 */
3340 ret = print_tabs(session, nesting);
3341 if (ret)
3342 return ret;
3343 ret = lttng_metadata_printf(session,
3344 "string%s",
3345 type->u.string.encoding == lttng_encode_ASCII ?
3346 " { encoding = ASCII; }" : "");
3347 return ret;
3348 }
3349
3350 static
3351 int _lttng_string_field_statedump(struct lttng_session *session,
3352 const struct lttng_event_field *field,
3353 size_t nesting)
3354 {
3355 int ret;
3356
3357 WARN_ON_ONCE(field->type.atype != atype_string);
3358 ret = _lttng_string_type_statedump(session, &field->type, nesting);
3359 if (ret)
3360 return ret;
3361 return lttng_field_name_statedump(session, field, nesting);
3362 }
3363
3364 /*
3365 * Must be called with sessions_mutex held.
3366 */
3367 static
3368 int _lttng_type_statedump(struct lttng_session *session,
3369 const struct lttng_type *type,
3370 size_t nesting)
3371 {
3372 int ret = 0;
3373
3374 switch (type->atype) {
3375 case atype_integer:
3376 ret = _lttng_integer_type_statedump(session, type, nesting);
3377 break;
3378 case atype_enum_nestable:
3379 ret = _lttng_enum_type_statedump(session, type, nesting);
3380 break;
3381 case atype_string:
3382 ret = _lttng_string_type_statedump(session, type, nesting);
3383 break;
3384 case atype_struct_nestable:
3385 ret = _lttng_struct_type_statedump(session, type, nesting);
3386 break;
3387 case atype_variant_nestable:
3388 ret = _lttng_variant_type_statedump(session, type, nesting);
3389 break;
3390
3391 /* Nested arrays and sequences are not supported yet. */
3392 case atype_array_nestable:
3393 case atype_sequence_nestable:
3394 default:
3395 WARN_ON_ONCE(1);
3396 return -EINVAL;
3397 }
3398 return ret;
3399 }
3400
3401 /*
3402 * Must be called with sessions_mutex held.
3403 */
3404 static
3405 int _lttng_field_statedump(struct lttng_session *session,
3406 const struct lttng_event_field *field,
3407 size_t nesting)
3408 {
3409 int ret = 0;
3410
3411 switch (field->type.atype) {
3412 case atype_integer:
3413 ret = _lttng_integer_field_statedump(session, field, nesting);
3414 break;
3415 case atype_enum_nestable:
3416 ret = _lttng_enum_field_statedump(session, field, nesting);
3417 break;
3418 case atype_string:
3419 ret = _lttng_string_field_statedump(session, field, nesting);
3420 break;
3421 case atype_struct_nestable:
3422 ret = _lttng_struct_field_statedump(session, field, nesting);
3423 break;
3424 case atype_array_nestable:
3425 ret = _lttng_array_field_statedump(session, field, nesting);
3426 break;
3427 case atype_sequence_nestable:
3428 ret = _lttng_sequence_field_statedump(session, field, nesting);
3429 break;
3430 case atype_variant_nestable:
3431 ret = _lttng_variant_field_statedump(session, field, nesting);
3432 break;
3433
3434 default:
3435 WARN_ON_ONCE(1);
3436 return -EINVAL;
3437 }
3438 return ret;
3439 }
3440
3441 static
3442 int _lttng_context_metadata_statedump(struct lttng_session *session,
3443 struct lttng_ctx *ctx)
3444 {
3445 int ret = 0;
3446 int i;
3447
3448 if (!ctx)
3449 return 0;
3450 for (i = 0; i < ctx->nr_fields; i++) {
3451 const struct lttng_ctx_field *field = &ctx->fields[i];
3452
3453 ret = _lttng_field_statedump(session, &field->event_field, 2);
3454 if (ret)
3455 return ret;
3456 }
3457 return ret;
3458 }
3459
3460 static
3461 int _lttng_fields_metadata_statedump(struct lttng_session *session,
3462 struct lttng_event *event)
3463 {
3464 const struct lttng_event_desc *desc = event->desc;
3465 int ret = 0;
3466 int i;
3467
3468 for (i = 0; i < desc->nr_fields; i++) {
3469 const struct lttng_event_field *field = &desc->fields[i];
3470
3471 ret = _lttng_field_statedump(session, field, 2);
3472 if (ret)
3473 return ret;
3474 }
3475 return ret;
3476 }
3477
3478 /*
3479 * Must be called with sessions_mutex held.
3480 * The entire event metadata is printed as a single atomic metadata
3481 * transaction.
3482 */
3483 static
3484 int _lttng_event_metadata_statedump(struct lttng_session *session,
3485 struct lttng_channel *chan,
3486 struct lttng_event *event)
3487 {
3488 int ret = 0;
3489
3490 if (event->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3491 return 0;
3492 if (chan->channel_type == METADATA_CHANNEL)
3493 return 0;
3494
3495 lttng_metadata_begin(session);
3496
3497 ret = lttng_metadata_printf(session,
3498 "event {\n"
3499 " name = \"%s\";\n"
3500 " id = %u;\n"
3501 " stream_id = %u;\n",
3502 event->desc->name,
3503 event->id,
3504 event->chan->id);
3505 if (ret)
3506 goto end;
3507
3508 if (event->ctx) {
3509 ret = lttng_metadata_printf(session,
3510 " context := struct {\n");
3511 if (ret)
3512 goto end;
3513 }
3514 ret = _lttng_context_metadata_statedump(session, event->ctx);
3515 if (ret)
3516 goto end;
3517 if (event->ctx) {
3518 ret = lttng_metadata_printf(session,
3519 " };\n");
3520 if (ret)
3521 goto end;
3522 }
3523
3524 ret = lttng_metadata_printf(session,
3525 " fields := struct {\n"
3526 );
3527 if (ret)
3528 goto end;
3529
3530 ret = _lttng_fields_metadata_statedump(session, event);
3531 if (ret)
3532 goto end;
3533
3534 /*
3535 * LTTng space reservation can only reserve multiples of the
3536 * byte size.
3537 */
3538 ret = lttng_metadata_printf(session,
3539 " };\n"
3540 "};\n\n");
3541 if (ret)
3542 goto end;
3543
3544 event->metadata_dumped = 1;
3545 end:
3546 lttng_metadata_end(session);
3547 return ret;
3548
3549 }
3550
3551 /*
3552 * Must be called with sessions_mutex held.
3553 * The entire channel metadata is printed as a single atomic metadata
3554 * transaction.
3555 */
3556 static
3557 int _lttng_channel_metadata_statedump(struct lttng_session *session,
3558 struct lttng_channel *chan)
3559 {
3560 int ret = 0;
3561
3562 if (chan->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3563 return 0;
3564
3565 if (chan->channel_type == METADATA_CHANNEL)
3566 return 0;
3567
3568 lttng_metadata_begin(session);
3569
3570 WARN_ON_ONCE(!chan->header_type);
3571 ret = lttng_metadata_printf(session,
3572 "stream {\n"
3573 " id = %u;\n"
3574 " event.header := %s;\n"
3575 " packet.context := struct packet_context;\n",
3576 chan->id,
3577 chan->header_type == 1 ? "struct event_header_compact" :
3578 "struct event_header_large");
3579 if (ret)
3580 goto end;
3581
3582 if (chan->ctx) {
3583 ret = lttng_metadata_printf(session,
3584 " event.context := struct {\n");
3585 if (ret)
3586 goto end;
3587 }
3588 ret = _lttng_context_metadata_statedump(session, chan->ctx);
3589 if (ret)
3590 goto end;
3591 if (chan->ctx) {
3592 ret = lttng_metadata_printf(session,
3593 " };\n");
3594 if (ret)
3595 goto end;
3596 }
3597
3598 ret = lttng_metadata_printf(session,
3599 "};\n\n");
3600
3601 chan->metadata_dumped = 1;
3602 end:
3603 lttng_metadata_end(session);
3604 return ret;
3605 }
3606
3607 /*
3608 * Must be called with sessions_mutex held.
3609 */
3610 static
3611 int _lttng_stream_packet_context_declare(struct lttng_session *session)
3612 {
3613 return lttng_metadata_printf(session,
3614 "struct packet_context {\n"
3615 " uint64_clock_monotonic_t timestamp_begin;\n"
3616 " uint64_clock_monotonic_t timestamp_end;\n"
3617 " uint64_t content_size;\n"
3618 " uint64_t packet_size;\n"
3619 " uint64_t packet_seq_num;\n"
3620 " unsigned long events_discarded;\n"
3621 " uint32_t cpu_id;\n"
3622 "};\n\n"
3623 );
3624 }
3625
3626 /*
3627 * Compact header:
3628 * id: range: 0 - 30.
3629 * id 31 is reserved to indicate an extended header.
3630 *
3631 * Large header:
3632 * id: range: 0 - 65534.
3633 * id 65535 is reserved to indicate an extended header.
3634 *
3635 * Must be called with sessions_mutex held.
3636 */
3637 static
3638 int _lttng_event_header_declare(struct lttng_session *session)
3639 {
3640 return lttng_metadata_printf(session,
3641 "struct event_header_compact {\n"
3642 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3643 " variant <id> {\n"
3644 " struct {\n"
3645 " uint27_clock_monotonic_t timestamp;\n"
3646 " } compact;\n"
3647 " struct {\n"
3648 " uint32_t id;\n"
3649 " uint64_clock_monotonic_t timestamp;\n"
3650 " } extended;\n"
3651 " } v;\n"
3652 "} align(%u);\n"
3653 "\n"
3654 "struct event_header_large {\n"
3655 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3656 " variant <id> {\n"
3657 " struct {\n"
3658 " uint32_clock_monotonic_t timestamp;\n"
3659 " } compact;\n"
3660 " struct {\n"
3661 " uint32_t id;\n"
3662 " uint64_clock_monotonic_t timestamp;\n"
3663 " } extended;\n"
3664 " } v;\n"
3665 "} align(%u);\n\n",
3666 lttng_alignof(uint32_t) * CHAR_BIT,
3667 lttng_alignof(uint16_t) * CHAR_BIT
3668 );
3669 }
3670
3671 /*
3672 * Approximation of NTP time of day to clock monotonic correlation,
3673 * taken at start of trace.
3674 * Yes, this is only an approximation. Yes, we can (and will) do better
3675 * in future versions.
3676 * This function may return a negative offset. It may happen if the
3677 * system sets the REALTIME clock to 0 after boot.
3678 *
3679 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3680 * y2038 compliant.
3681 */
3682 static
3683 int64_t measure_clock_offset(void)
3684 {
3685 uint64_t monotonic_avg, monotonic[2], realtime;
3686 uint64_t tcf = trace_clock_freq();
3687 int64_t offset;
3688 unsigned long flags;
3689 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3690 struct timespec64 rts = { 0, 0 };
3691 #else
3692 struct timespec rts = { 0, 0 };
3693 #endif
3694
3695 /* Disable interrupts to increase correlation precision. */
3696 local_irq_save(flags);
3697 monotonic[0] = trace_clock_read64();
3698 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3699 ktime_get_real_ts64(&rts);
3700 #else
3701 getnstimeofday(&rts);
3702 #endif
3703 monotonic[1] = trace_clock_read64();
3704 local_irq_restore(flags);
3705
3706 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3707 realtime = (uint64_t) rts.tv_sec * tcf;
3708 if (tcf == NSEC_PER_SEC) {
3709 realtime += rts.tv_nsec;
3710 } else {
3711 uint64_t n = rts.tv_nsec * tcf;
3712
3713 do_div(n, NSEC_PER_SEC);
3714 realtime += n;
3715 }
3716 offset = (int64_t) realtime - monotonic_avg;
3717 return offset;
3718 }
3719
3720 static
3721 int print_escaped_ctf_string(struct lttng_session *session, const char *string)
3722 {
3723 int ret = 0;
3724 size_t i;
3725 char cur;
3726
3727 i = 0;
3728 cur = string[i];
3729 while (cur != '\0') {
3730 switch (cur) {
3731 case '\n':
3732 ret = lttng_metadata_printf(session, "%s", "\\n");
3733 break;
3734 case '\\':
3735 case '"':
3736 ret = lttng_metadata_printf(session, "%c", '\\');
3737 if (ret)
3738 goto error;
3739 /* We still print the current char */
3740 /* Fallthrough */
3741 default:
3742 ret = lttng_metadata_printf(session, "%c", cur);
3743 break;
3744 }
3745
3746 if (ret)
3747 goto error;
3748
3749 cur = string[++i];
3750 }
3751 error:
3752 return ret;
3753 }
3754
3755 static
3756 int print_metadata_escaped_field(struct lttng_session *session, const char *field,
3757 const char *field_value)
3758 {
3759 int ret;
3760
3761 ret = lttng_metadata_printf(session, " %s = \"", field);
3762 if (ret)
3763 goto error;
3764
3765 ret = print_escaped_ctf_string(session, field_value);
3766 if (ret)
3767 goto error;
3768
3769 ret = lttng_metadata_printf(session, "\";\n");
3770
3771 error:
3772 return ret;
3773 }
3774
3775 /*
3776 * Output metadata into this session's metadata buffers.
3777 * Must be called with sessions_mutex held.
3778 */
3779 static
3780 int _lttng_session_metadata_statedump(struct lttng_session *session)
3781 {
3782 unsigned char *uuid_c = session->uuid.b;
3783 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3784 const char *product_uuid;
3785 struct lttng_channel *chan;
3786 struct lttng_event *event;
3787 int ret = 0;
3788
3789 if (!LTTNG_READ_ONCE(session->active))
3790 return 0;
3791
3792 lttng_metadata_begin(session);
3793
3794 if (session->metadata_dumped)
3795 goto skip_session;
3796
3797 snprintf(uuid_s, sizeof(uuid_s),
3798 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3799 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3800 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3801 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3802 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3803
3804 ret = lttng_metadata_printf(session,
3805 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3806 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3807 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3808 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3809 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3810 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3811 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3812 "\n"
3813 "trace {\n"
3814 " major = %u;\n"
3815 " minor = %u;\n"
3816 " uuid = \"%s\";\n"
3817 " byte_order = %s;\n"
3818 " packet.header := struct {\n"
3819 " uint32_t magic;\n"
3820 " uint8_t uuid[16];\n"
3821 " uint32_t stream_id;\n"
3822 " uint64_t stream_instance_id;\n"
3823 " };\n"
3824 "};\n\n",
3825 lttng_alignof(uint8_t) * CHAR_BIT,
3826 lttng_alignof(uint16_t) * CHAR_BIT,
3827 lttng_alignof(uint32_t) * CHAR_BIT,
3828 lttng_alignof(uint64_t) * CHAR_BIT,
3829 sizeof(unsigned long) * CHAR_BIT,
3830 lttng_alignof(unsigned long) * CHAR_BIT,
3831 CTF_SPEC_MAJOR,
3832 CTF_SPEC_MINOR,
3833 uuid_s,
3834 #if __BYTE_ORDER == __BIG_ENDIAN
3835 "be"
3836 #else
3837 "le"
3838 #endif
3839 );
3840 if (ret)
3841 goto end;
3842
3843 ret = lttng_metadata_printf(session,
3844 "env {\n"
3845 " hostname = \"%s\";\n"
3846 " domain = \"kernel\";\n"
3847 " sysname = \"%s\";\n"
3848 " kernel_release = \"%s\";\n"
3849 " kernel_version = \"%s\";\n"
3850 " tracer_name = \"lttng-modules\";\n"
3851 " tracer_major = %d;\n"
3852 " tracer_minor = %d;\n"
3853 " tracer_patchlevel = %d;\n"
3854 " trace_buffering_scheme = \"global\";\n",
3855 current->nsproxy->uts_ns->name.nodename,
3856 utsname()->sysname,
3857 utsname()->release,
3858 utsname()->version,
3859 LTTNG_MODULES_MAJOR_VERSION,
3860 LTTNG_MODULES_MINOR_VERSION,
3861 LTTNG_MODULES_PATCHLEVEL_VERSION
3862 );
3863 if (ret)
3864 goto end;
3865
3866 ret = print_metadata_escaped_field(session, "trace_name", session->name);
3867 if (ret)
3868 goto end;
3869 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
3870 session->creation_time);
3871 if (ret)
3872 goto end;
3873
3874 /* Add the product UUID to the 'env' section */
3875 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
3876 if (product_uuid) {
3877 ret = lttng_metadata_printf(session,
3878 " product_uuid = \"%s\";\n",
3879 product_uuid
3880 );
3881 if (ret)
3882 goto end;
3883 }
3884
3885 /* Close the 'env' section */
3886 ret = lttng_metadata_printf(session, "};\n\n");
3887 if (ret)
3888 goto end;
3889
3890 ret = lttng_metadata_printf(session,
3891 "clock {\n"
3892 " name = \"%s\";\n",
3893 trace_clock_name()
3894 );
3895 if (ret)
3896 goto end;
3897
3898 if (!trace_clock_uuid(clock_uuid_s)) {
3899 ret = lttng_metadata_printf(session,
3900 " uuid = \"%s\";\n",
3901 clock_uuid_s
3902 );
3903 if (ret)
3904 goto end;
3905 }
3906
3907 ret = lttng_metadata_printf(session,
3908 " description = \"%s\";\n"
3909 " freq = %llu; /* Frequency, in Hz */\n"
3910 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
3911 " offset = %lld;\n"
3912 "};\n\n",
3913 trace_clock_description(),
3914 (unsigned long long) trace_clock_freq(),
3915 (long long) measure_clock_offset()
3916 );
3917 if (ret)
3918 goto end;
3919
3920 ret = lttng_metadata_printf(session,
3921 "typealias integer {\n"
3922 " size = 27; align = 1; signed = false;\n"
3923 " map = clock.%s.value;\n"
3924 "} := uint27_clock_monotonic_t;\n"
3925 "\n"
3926 "typealias integer {\n"
3927 " size = 32; align = %u; signed = false;\n"
3928 " map = clock.%s.value;\n"
3929 "} := uint32_clock_monotonic_t;\n"
3930 "\n"
3931 "typealias integer {\n"
3932 " size = 64; align = %u; signed = false;\n"
3933 " map = clock.%s.value;\n"
3934 "} := uint64_clock_monotonic_t;\n\n",
3935 trace_clock_name(),
3936 lttng_alignof(uint32_t) * CHAR_BIT,
3937 trace_clock_name(),
3938 lttng_alignof(uint64_t) * CHAR_BIT,
3939 trace_clock_name()
3940 );
3941 if (ret)
3942 goto end;
3943
3944 ret = _lttng_stream_packet_context_declare(session);
3945 if (ret)
3946 goto end;
3947
3948 ret = _lttng_event_header_declare(session);
3949 if (ret)
3950 goto end;
3951
3952 skip_session:
3953 list_for_each_entry(chan, &session->chan, list) {
3954 ret = _lttng_channel_metadata_statedump(session, chan);
3955 if (ret)
3956 goto end;
3957 }
3958
3959 list_for_each_entry(event, &session->events, list) {
3960 ret = _lttng_event_metadata_statedump(session, event->chan, event);
3961 if (ret)
3962 goto end;
3963 }
3964 session->metadata_dumped = 1;
3965 end:
3966 lttng_metadata_end(session);
3967 return ret;
3968 }
3969
3970 /**
3971 * lttng_transport_register - LTT transport registration
3972 * @transport: transport structure
3973 *
3974 * Registers a transport which can be used as output to extract the data out of
3975 * LTTng. The module calling this registration function must ensure that no
3976 * trap-inducing code will be executed by the transport functions. E.g.
3977 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
3978 * is made visible to the transport function. This registration acts as a
3979 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
3980 * after its registration must it synchronize the TLBs.
3981 */
3982 void lttng_transport_register(struct lttng_transport *transport)
3983 {
3984 /*
3985 * Make sure no page fault can be triggered by the module about to be
3986 * registered. We deal with this here so we don't have to call
3987 * vmalloc_sync_mappings() in each module's init.
3988 */
3989 wrapper_vmalloc_sync_mappings();
3990
3991 mutex_lock(&sessions_mutex);
3992 list_add_tail(&transport->node, &lttng_transport_list);
3993 mutex_unlock(&sessions_mutex);
3994 }
3995 EXPORT_SYMBOL_GPL(lttng_transport_register);
3996
3997 /**
3998 * lttng_transport_unregister - LTT transport unregistration
3999 * @transport: transport structure
4000 */
4001 void lttng_transport_unregister(struct lttng_transport *transport)
4002 {
4003 mutex_lock(&sessions_mutex);
4004 list_del(&transport->node);
4005 mutex_unlock(&sessions_mutex);
4006 }
4007 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4008
4009 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4010 {
4011 /*
4012 * Make sure no page fault can be triggered by the module about to be
4013 * registered. We deal with this here so we don't have to call
4014 * vmalloc_sync_mappings() in each module's init.
4015 */
4016 wrapper_vmalloc_sync_mappings();
4017
4018 mutex_lock(&sessions_mutex);
4019 list_add_tail(&transport->node, &lttng_counter_transport_list);
4020 mutex_unlock(&sessions_mutex);
4021 }
4022 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4023
4024 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4025 {
4026 mutex_lock(&sessions_mutex);
4027 list_del(&transport->node);
4028 mutex_unlock(&sessions_mutex);
4029 }
4030 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4031
4032 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4033
4034 enum cpuhp_state lttng_hp_prepare;
4035 enum cpuhp_state lttng_hp_online;
4036
4037 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4038 {
4039 struct lttng_cpuhp_node *lttng_node;
4040
4041 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4042 switch (lttng_node->component) {
4043 case LTTNG_RING_BUFFER_FRONTEND:
4044 return 0;
4045 case LTTNG_RING_BUFFER_BACKEND:
4046 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4047 case LTTNG_RING_BUFFER_ITER:
4048 return 0;
4049 case LTTNG_CONTEXT_PERF_COUNTERS:
4050 return 0;
4051 default:
4052 return -EINVAL;
4053 }
4054 }
4055
4056 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4057 {
4058 struct lttng_cpuhp_node *lttng_node;
4059
4060 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4061 switch (lttng_node->component) {
4062 case LTTNG_RING_BUFFER_FRONTEND:
4063 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4064 case LTTNG_RING_BUFFER_BACKEND:
4065 return 0;
4066 case LTTNG_RING_BUFFER_ITER:
4067 return 0;
4068 case LTTNG_CONTEXT_PERF_COUNTERS:
4069 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4070 default:
4071 return -EINVAL;
4072 }
4073 }
4074
4075 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4076 {
4077 struct lttng_cpuhp_node *lttng_node;
4078
4079 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4080 switch (lttng_node->component) {
4081 case LTTNG_RING_BUFFER_FRONTEND:
4082 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4083 case LTTNG_RING_BUFFER_BACKEND:
4084 return 0;
4085 case LTTNG_RING_BUFFER_ITER:
4086 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4087 case LTTNG_CONTEXT_PERF_COUNTERS:
4088 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4089 default:
4090 return -EINVAL;
4091 }
4092 }
4093
4094 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4095 {
4096 struct lttng_cpuhp_node *lttng_node;
4097
4098 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4099 switch (lttng_node->component) {
4100 case LTTNG_RING_BUFFER_FRONTEND:
4101 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4102 case LTTNG_RING_BUFFER_BACKEND:
4103 return 0;
4104 case LTTNG_RING_BUFFER_ITER:
4105 return 0;
4106 case LTTNG_CONTEXT_PERF_COUNTERS:
4107 return 0;
4108 default:
4109 return -EINVAL;
4110 }
4111 }
4112
4113 static int __init lttng_init_cpu_hotplug(void)
4114 {
4115 int ret;
4116
4117 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4118 lttng_hotplug_prepare,
4119 lttng_hotplug_dead);
4120 if (ret < 0) {
4121 return ret;
4122 }
4123 lttng_hp_prepare = ret;
4124 lttng_rb_set_hp_prepare(ret);
4125
4126 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4127 lttng_hotplug_online,
4128 lttng_hotplug_offline);
4129 if (ret < 0) {
4130 cpuhp_remove_multi_state(lttng_hp_prepare);
4131 lttng_hp_prepare = 0;
4132 return ret;
4133 }
4134 lttng_hp_online = ret;
4135 lttng_rb_set_hp_online(ret);
4136
4137 return 0;
4138 }
4139
4140 static void __exit lttng_exit_cpu_hotplug(void)
4141 {
4142 lttng_rb_set_hp_online(0);
4143 cpuhp_remove_multi_state(lttng_hp_online);
4144 lttng_rb_set_hp_prepare(0);
4145 cpuhp_remove_multi_state(lttng_hp_prepare);
4146 }
4147
4148 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4149 static int lttng_init_cpu_hotplug(void)
4150 {
4151 return 0;
4152 }
4153 static void lttng_exit_cpu_hotplug(void)
4154 {
4155 }
4156 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4157
4158
4159 static int __init lttng_events_init(void)
4160 {
4161 int ret;
4162
4163 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4164 if (ret)
4165 return ret;
4166 ret = wrapper_get_pfnblock_flags_mask_init();
4167 if (ret)
4168 return ret;
4169 ret = wrapper_get_pageblock_flags_mask_init();
4170 if (ret)
4171 return ret;
4172 ret = lttng_probes_init();
4173 if (ret)
4174 return ret;
4175 ret = lttng_context_init();
4176 if (ret)
4177 return ret;
4178 ret = lttng_tracepoint_init();
4179 if (ret)
4180 goto error_tp;
4181 event_cache = KMEM_CACHE(lttng_event, 0);
4182 if (!event_cache) {
4183 ret = -ENOMEM;
4184 goto error_kmem_event;
4185 }
4186 event_notifier_cache = KMEM_CACHE(lttng_event_notifier, 0);
4187 if (!event_notifier_cache) {
4188 ret = -ENOMEM;
4189 goto error_kmem_event_notifier;
4190 }
4191 ret = lttng_abi_init();
4192 if (ret)
4193 goto error_abi;
4194 ret = lttng_logger_init();
4195 if (ret)
4196 goto error_logger;
4197 ret = lttng_init_cpu_hotplug();
4198 if (ret)
4199 goto error_hotplug;
4200 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4201 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4202 __stringify(LTTNG_MODULES_MINOR_VERSION),
4203 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4204 LTTNG_MODULES_EXTRAVERSION,
4205 LTTNG_VERSION_NAME,
4206 #ifdef LTTNG_EXTRA_VERSION_GIT
4207 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4208 #else
4209 "",
4210 #endif
4211 #ifdef LTTNG_EXTRA_VERSION_NAME
4212 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4213 #else
4214 "");
4215 #endif
4216 return 0;
4217
4218 error_hotplug:
4219 lttng_logger_exit();
4220 error_logger:
4221 lttng_abi_exit();
4222 error_abi:
4223 kmem_cache_destroy(event_notifier_cache);
4224 error_kmem_event_notifier:
4225 kmem_cache_destroy(event_cache);
4226 error_kmem_event:
4227 lttng_tracepoint_exit();
4228 error_tp:
4229 lttng_context_exit();
4230 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4231 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4232 __stringify(LTTNG_MODULES_MINOR_VERSION),
4233 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4234 LTTNG_MODULES_EXTRAVERSION,
4235 LTTNG_VERSION_NAME,
4236 #ifdef LTTNG_EXTRA_VERSION_GIT
4237 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4238 #else
4239 "",
4240 #endif
4241 #ifdef LTTNG_EXTRA_VERSION_NAME
4242 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4243 #else
4244 "");
4245 #endif
4246 return ret;
4247 }
4248
4249 module_init(lttng_events_init);
4250
4251 static void __exit lttng_events_exit(void)
4252 {
4253 struct lttng_session *session, *tmpsession;
4254
4255 lttng_exit_cpu_hotplug();
4256 lttng_logger_exit();
4257 lttng_abi_exit();
4258 list_for_each_entry_safe(session, tmpsession, &sessions, list)
4259 lttng_session_destroy(session);
4260 kmem_cache_destroy(event_cache);
4261 kmem_cache_destroy(event_notifier_cache);
4262 lttng_tracepoint_exit();
4263 lttng_context_exit();
4264 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4265 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4266 __stringify(LTTNG_MODULES_MINOR_VERSION),
4267 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4268 LTTNG_MODULES_EXTRAVERSION,
4269 LTTNG_VERSION_NAME,
4270 #ifdef LTTNG_EXTRA_VERSION_GIT
4271 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4272 #else
4273 "",
4274 #endif
4275 #ifdef LTTNG_EXTRA_VERSION_NAME
4276 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4277 #else
4278 "");
4279 #endif
4280 }
4281
4282 module_exit(lttng_events_exit);
4283
4284 #include <generated/patches.h>
4285 #ifdef LTTNG_EXTRA_VERSION_GIT
4286 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4287 #endif
4288 #ifdef LTTNG_EXTRA_VERSION_NAME
4289 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4290 #endif
4291 MODULE_LICENSE("GPL and additional rights");
4292 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4293 MODULE_DESCRIPTION("LTTng tracer");
4294 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4295 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4296 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4297 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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