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Fix: memory leaks on event notifier destroy
[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 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1489
1490 switch (event->instrumentation) {
1491 case LTTNG_KERNEL_TRACEPOINT:
1492 lttng_event_desc_put(event->desc);
1493 break;
1494 case LTTNG_KERNEL_KPROBE:
1495 module_put(event->desc->owner);
1496 lttng_kprobes_destroy_event_private(event);
1497 break;
1498 case LTTNG_KERNEL_KRETPROBE:
1499 module_put(event->desc->owner);
1500 lttng_kretprobes_destroy_private(event);
1501 break;
1502 case LTTNG_KERNEL_NOOP:
1503 case LTTNG_KERNEL_SYSCALL:
1504 break;
1505 case LTTNG_KERNEL_UPROBE:
1506 module_put(event->desc->owner);
1507 lttng_uprobes_destroy_event_private(event);
1508 break;
1509 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1510 default:
1511 WARN_ON_ONCE(1);
1512 }
1513 list_del(&event->list);
1514 lttng_destroy_context(event->ctx);
1515 lttng_free_event_filter_runtime(event);
1516 /* Free event enabler refs */
1517 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1518 &event->enablers_ref_head, node)
1519 kfree(enabler_ref);
1520 kmem_cache_free(event_cache, event);
1521 }
1522
1523 /*
1524 * Only used internally at session destruction.
1525 */
1526 static
1527 void _lttng_event_notifier_destroy(struct lttng_event_notifier *event_notifier)
1528 {
1529 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1530
1531 switch (event_notifier->instrumentation) {
1532 case LTTNG_KERNEL_TRACEPOINT:
1533 lttng_event_desc_put(event_notifier->desc);
1534 break;
1535 case LTTNG_KERNEL_KPROBE:
1536 module_put(event_notifier->desc->owner);
1537 lttng_kprobes_destroy_event_notifier_private(event_notifier);
1538 break;
1539 case LTTNG_KERNEL_NOOP:
1540 case LTTNG_KERNEL_SYSCALL:
1541 break;
1542 case LTTNG_KERNEL_UPROBE:
1543 module_put(event_notifier->desc->owner);
1544 lttng_uprobes_destroy_event_notifier_private(event_notifier);
1545 break;
1546 case LTTNG_KERNEL_KRETPROBE:
1547 case LTTNG_KERNEL_FUNCTION:
1548 default:
1549 WARN_ON_ONCE(1);
1550 }
1551 list_del(&event_notifier->list);
1552 lttng_free_event_notifier_filter_runtime(event_notifier);
1553 /* Free event enabler refs */
1554 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1555 &event_notifier->enablers_ref_head, node)
1556 kfree(enabler_ref);
1557 kmem_cache_free(event_notifier_cache, event_notifier);
1558 }
1559
1560 struct lttng_id_tracker *get_tracker(struct lttng_session *session,
1561 enum tracker_type tracker_type)
1562 {
1563 switch (tracker_type) {
1564 case TRACKER_PID:
1565 return &session->pid_tracker;
1566 case TRACKER_VPID:
1567 return &session->vpid_tracker;
1568 case TRACKER_UID:
1569 return &session->uid_tracker;
1570 case TRACKER_VUID:
1571 return &session->vuid_tracker;
1572 case TRACKER_GID:
1573 return &session->gid_tracker;
1574 case TRACKER_VGID:
1575 return &session->vgid_tracker;
1576 default:
1577 WARN_ON_ONCE(1);
1578 return NULL;
1579 }
1580 }
1581
1582 int lttng_session_track_id(struct lttng_session *session,
1583 enum tracker_type tracker_type, int id)
1584 {
1585 struct lttng_id_tracker *tracker;
1586 int ret;
1587
1588 tracker = get_tracker(session, tracker_type);
1589 if (!tracker)
1590 return -EINVAL;
1591 if (id < -1)
1592 return -EINVAL;
1593 mutex_lock(&sessions_mutex);
1594 if (id == -1) {
1595 /* track all ids: destroy tracker. */
1596 lttng_id_tracker_destroy(tracker, true);
1597 ret = 0;
1598 } else {
1599 ret = lttng_id_tracker_add(tracker, id);
1600 }
1601 mutex_unlock(&sessions_mutex);
1602 return ret;
1603 }
1604
1605 int lttng_session_untrack_id(struct lttng_session *session,
1606 enum tracker_type tracker_type, int id)
1607 {
1608 struct lttng_id_tracker *tracker;
1609 int ret;
1610
1611 tracker = get_tracker(session, tracker_type);
1612 if (!tracker)
1613 return -EINVAL;
1614 if (id < -1)
1615 return -EINVAL;
1616 mutex_lock(&sessions_mutex);
1617 if (id == -1) {
1618 /* untrack all ids: replace by empty tracker. */
1619 ret = lttng_id_tracker_empty_set(tracker);
1620 } else {
1621 ret = lttng_id_tracker_del(tracker, id);
1622 }
1623 mutex_unlock(&sessions_mutex);
1624 return ret;
1625 }
1626
1627 static
1628 void *id_list_start(struct seq_file *m, loff_t *pos)
1629 {
1630 struct lttng_id_tracker *id_tracker = m->private;
1631 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1632 struct lttng_id_hash_node *e;
1633 int iter = 0, i;
1634
1635 mutex_lock(&sessions_mutex);
1636 if (id_tracker_p) {
1637 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1638 struct hlist_head *head = &id_tracker_p->id_hash[i];
1639
1640 lttng_hlist_for_each_entry(e, head, hlist) {
1641 if (iter++ >= *pos)
1642 return e;
1643 }
1644 }
1645 } else {
1646 /* ID tracker disabled. */
1647 if (iter >= *pos && iter == 0) {
1648 return id_tracker_p; /* empty tracker */
1649 }
1650 iter++;
1651 }
1652 /* End of list */
1653 return NULL;
1654 }
1655
1656 /* Called with sessions_mutex held. */
1657 static
1658 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1659 {
1660 struct lttng_id_tracker *id_tracker = m->private;
1661 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1662 struct lttng_id_hash_node *e;
1663 int iter = 0, i;
1664
1665 (*ppos)++;
1666 if (id_tracker_p) {
1667 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1668 struct hlist_head *head = &id_tracker_p->id_hash[i];
1669
1670 lttng_hlist_for_each_entry(e, head, hlist) {
1671 if (iter++ >= *ppos)
1672 return e;
1673 }
1674 }
1675 } else {
1676 /* ID tracker disabled. */
1677 if (iter >= *ppos && iter == 0)
1678 return p; /* empty tracker */
1679 iter++;
1680 }
1681
1682 /* End of list */
1683 return NULL;
1684 }
1685
1686 static
1687 void id_list_stop(struct seq_file *m, void *p)
1688 {
1689 mutex_unlock(&sessions_mutex);
1690 }
1691
1692 static
1693 int id_list_show(struct seq_file *m, void *p)
1694 {
1695 struct lttng_id_tracker *id_tracker = m->private;
1696 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1697 int id;
1698
1699 if (p == id_tracker_p) {
1700 /* Tracker disabled. */
1701 id = -1;
1702 } else {
1703 const struct lttng_id_hash_node *e = p;
1704
1705 id = lttng_id_tracker_get_node_id(e);
1706 }
1707 switch (id_tracker->tracker_type) {
1708 case TRACKER_PID:
1709 seq_printf(m, "process { pid = %d; };\n", id);
1710 break;
1711 case TRACKER_VPID:
1712 seq_printf(m, "process { vpid = %d; };\n", id);
1713 break;
1714 case TRACKER_UID:
1715 seq_printf(m, "user { uid = %d; };\n", id);
1716 break;
1717 case TRACKER_VUID:
1718 seq_printf(m, "user { vuid = %d; };\n", id);
1719 break;
1720 case TRACKER_GID:
1721 seq_printf(m, "group { gid = %d; };\n", id);
1722 break;
1723 case TRACKER_VGID:
1724 seq_printf(m, "group { vgid = %d; };\n", id);
1725 break;
1726 default:
1727 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1728 }
1729 return 0;
1730 }
1731
1732 static
1733 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1734 .start = id_list_start,
1735 .next = id_list_next,
1736 .stop = id_list_stop,
1737 .show = id_list_show,
1738 };
1739
1740 static
1741 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1742 {
1743 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1744 }
1745
1746 static
1747 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1748 {
1749 struct seq_file *m = file->private_data;
1750 struct lttng_id_tracker *id_tracker = m->private;
1751 int ret;
1752
1753 WARN_ON_ONCE(!id_tracker);
1754 ret = seq_release(inode, file);
1755 if (!ret)
1756 fput(id_tracker->session->file);
1757 return ret;
1758 }
1759
1760 const struct file_operations lttng_tracker_ids_list_fops = {
1761 .owner = THIS_MODULE,
1762 .open = lttng_tracker_ids_list_open,
1763 .read = seq_read,
1764 .llseek = seq_lseek,
1765 .release = lttng_tracker_ids_list_release,
1766 };
1767
1768 int lttng_session_list_tracker_ids(struct lttng_session *session,
1769 enum tracker_type tracker_type)
1770 {
1771 struct file *tracker_ids_list_file;
1772 struct seq_file *m;
1773 int file_fd, ret;
1774
1775 file_fd = lttng_get_unused_fd();
1776 if (file_fd < 0) {
1777 ret = file_fd;
1778 goto fd_error;
1779 }
1780
1781 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1782 &lttng_tracker_ids_list_fops,
1783 NULL, O_RDWR);
1784 if (IS_ERR(tracker_ids_list_file)) {
1785 ret = PTR_ERR(tracker_ids_list_file);
1786 goto file_error;
1787 }
1788 if (!atomic_long_add_unless(&session->file->f_count, 1, LONG_MAX)) {
1789 ret = -EOVERFLOW;
1790 goto refcount_error;
1791 }
1792 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1793 if (ret < 0)
1794 goto open_error;
1795 m = tracker_ids_list_file->private_data;
1796
1797 m->private = get_tracker(session, tracker_type);
1798 BUG_ON(!m->private);
1799 fd_install(file_fd, tracker_ids_list_file);
1800
1801 return file_fd;
1802
1803 open_error:
1804 atomic_long_dec(&session->file->f_count);
1805 refcount_error:
1806 fput(tracker_ids_list_file);
1807 file_error:
1808 put_unused_fd(file_fd);
1809 fd_error:
1810 return ret;
1811 }
1812
1813 /*
1814 * Enabler management.
1815 */
1816 static
1817 int lttng_match_enabler_star_glob(const char *desc_name,
1818 const char *pattern)
1819 {
1820 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1821 desc_name, LTTNG_SIZE_MAX))
1822 return 0;
1823 return 1;
1824 }
1825
1826 static
1827 int lttng_match_enabler_name(const char *desc_name,
1828 const char *name)
1829 {
1830 if (strcmp(desc_name, name))
1831 return 0;
1832 return 1;
1833 }
1834
1835 int lttng_desc_match_enabler(const struct lttng_event_desc *desc,
1836 struct lttng_enabler *enabler)
1837 {
1838 const char *desc_name, *enabler_name;
1839 bool compat = false, entry = false;
1840
1841 enabler_name = enabler->event_param.name;
1842 switch (enabler->event_param.instrumentation) {
1843 case LTTNG_KERNEL_TRACEPOINT:
1844 desc_name = desc->name;
1845 switch (enabler->format_type) {
1846 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1847 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1848 case LTTNG_ENABLER_FORMAT_NAME:
1849 return lttng_match_enabler_name(desc_name, enabler_name);
1850 default:
1851 return -EINVAL;
1852 }
1853 break;
1854 case LTTNG_KERNEL_SYSCALL:
1855 desc_name = desc->name;
1856 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
1857 desc_name += strlen("compat_");
1858 compat = true;
1859 }
1860 if (!strncmp(desc_name, "syscall_exit_",
1861 strlen("syscall_exit_"))) {
1862 desc_name += strlen("syscall_exit_");
1863 } else if (!strncmp(desc_name, "syscall_entry_",
1864 strlen("syscall_entry_"))) {
1865 desc_name += strlen("syscall_entry_");
1866 entry = true;
1867 } else {
1868 WARN_ON_ONCE(1);
1869 return -EINVAL;
1870 }
1871 switch (enabler->event_param.u.syscall.entryexit) {
1872 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
1873 break;
1874 case LTTNG_KERNEL_SYSCALL_ENTRY:
1875 if (!entry)
1876 return 0;
1877 break;
1878 case LTTNG_KERNEL_SYSCALL_EXIT:
1879 if (entry)
1880 return 0;
1881 break;
1882 default:
1883 return -EINVAL;
1884 }
1885 switch (enabler->event_param.u.syscall.abi) {
1886 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
1887 break;
1888 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
1889 if (compat)
1890 return 0;
1891 break;
1892 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
1893 if (!compat)
1894 return 0;
1895 break;
1896 default:
1897 return -EINVAL;
1898 }
1899 switch (enabler->event_param.u.syscall.match) {
1900 case LTTNG_KERNEL_SYSCALL_MATCH_NAME:
1901 switch (enabler->format_type) {
1902 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1903 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1904 case LTTNG_ENABLER_FORMAT_NAME:
1905 return lttng_match_enabler_name(desc_name, enabler_name);
1906 default:
1907 return -EINVAL;
1908 }
1909 break;
1910 case LTTNG_KERNEL_SYSCALL_MATCH_NR:
1911 return -EINVAL; /* Not implemented. */
1912 default:
1913 return -EINVAL;
1914 }
1915 break;
1916 default:
1917 WARN_ON_ONCE(1);
1918 return -EINVAL;
1919 }
1920 }
1921
1922 static
1923 int lttng_event_enabler_match_event(struct lttng_event_enabler *event_enabler,
1924 struct lttng_event *event)
1925 {
1926 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(
1927 event_enabler);
1928
1929 if (base_enabler->event_param.instrumentation != event->instrumentation)
1930 return 0;
1931 if (lttng_desc_match_enabler(event->desc, base_enabler)
1932 && event->chan == event_enabler->chan)
1933 return 1;
1934 else
1935 return 0;
1936 }
1937
1938 static
1939 int lttng_event_notifier_enabler_match_event_notifier(struct lttng_event_notifier_enabler *event_notifier_enabler,
1940 struct lttng_event_notifier *event_notifier)
1941 {
1942 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(
1943 event_notifier_enabler);
1944
1945 if (base_enabler->event_param.instrumentation != event_notifier->instrumentation)
1946 return 0;
1947 if (lttng_desc_match_enabler(event_notifier->desc, base_enabler)
1948 && event_notifier->group == event_notifier_enabler->group
1949 && event_notifier->user_token == event_notifier_enabler->base.user_token)
1950 return 1;
1951 else
1952 return 0;
1953 }
1954
1955 static
1956 struct lttng_enabler_ref *lttng_enabler_ref(
1957 struct list_head *enablers_ref_list,
1958 struct lttng_enabler *enabler)
1959 {
1960 struct lttng_enabler_ref *enabler_ref;
1961
1962 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
1963 if (enabler_ref->ref == enabler)
1964 return enabler_ref;
1965 }
1966 return NULL;
1967 }
1968
1969 static
1970 void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler *event_enabler)
1971 {
1972 struct lttng_session *session = event_enabler->chan->session;
1973 struct lttng_probe_desc *probe_desc;
1974 const struct lttng_event_desc *desc;
1975 int i;
1976 struct list_head *probe_list;
1977
1978 probe_list = lttng_get_probe_list_head();
1979 /*
1980 * For each probe event, if we find that a probe event matches
1981 * our enabler, create an associated lttng_event if not
1982 * already present.
1983 */
1984 list_for_each_entry(probe_desc, probe_list, head) {
1985 for (i = 0; i < probe_desc->nr_events; i++) {
1986 int found = 0;
1987 struct hlist_head *head;
1988 struct lttng_event *event;
1989
1990 desc = probe_desc->event_desc[i];
1991 if (!lttng_desc_match_enabler(desc,
1992 lttng_event_enabler_as_enabler(event_enabler)))
1993 continue;
1994
1995 /*
1996 * Check if already created.
1997 */
1998 head = utils_borrow_hash_table_bucket(
1999 session->events_ht.table, LTTNG_EVENT_HT_SIZE,
2000 desc->name);
2001 lttng_hlist_for_each_entry(event, head, hlist) {
2002 if (event->desc == desc
2003 && event->chan == event_enabler->chan)
2004 found = 1;
2005 }
2006 if (found)
2007 continue;
2008
2009 /*
2010 * We need to create an event for this
2011 * event probe.
2012 */
2013 event = _lttng_event_create(event_enabler->chan,
2014 NULL, NULL, desc,
2015 LTTNG_KERNEL_TRACEPOINT);
2016 if (!event) {
2017 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2018 probe_desc->event_desc[i]->name);
2019 }
2020 }
2021 }
2022 }
2023
2024 static
2025 void lttng_create_tracepoint_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2026 {
2027 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2028 struct lttng_probe_desc *probe_desc;
2029 const struct lttng_event_desc *desc;
2030 int i;
2031 struct list_head *probe_list;
2032
2033 probe_list = lttng_get_probe_list_head();
2034 /*
2035 * For each probe event, if we find that a probe event matches
2036 * our enabler, create an associated lttng_event_notifier if not
2037 * already present.
2038 */
2039 list_for_each_entry(probe_desc, probe_list, head) {
2040 for (i = 0; i < probe_desc->nr_events; i++) {
2041 int found = 0;
2042 struct hlist_head *head;
2043 struct lttng_event_notifier *event_notifier;
2044
2045 desc = probe_desc->event_desc[i];
2046 if (!lttng_desc_match_enabler(desc,
2047 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)))
2048 continue;
2049
2050 /*
2051 * Check if already created.
2052 */
2053 head = utils_borrow_hash_table_bucket(
2054 event_notifier_group->event_notifiers_ht.table,
2055 LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->name);
2056 lttng_hlist_for_each_entry(event_notifier, head, hlist) {
2057 if (event_notifier->desc == desc
2058 && event_notifier->user_token == event_notifier_enabler->base.user_token)
2059 found = 1;
2060 }
2061 if (found)
2062 continue;
2063
2064 /*
2065 * We need to create a event_notifier for this event probe.
2066 */
2067 event_notifier = _lttng_event_notifier_create(desc,
2068 event_notifier_enabler->base.user_token,
2069 event_notifier_enabler->error_counter_index,
2070 event_notifier_group, NULL, NULL,
2071 LTTNG_KERNEL_TRACEPOINT);
2072 if (IS_ERR(event_notifier)) {
2073 printk(KERN_INFO "Unable to create event_notifier %s\n",
2074 probe_desc->event_desc[i]->name);
2075 }
2076 }
2077 }
2078 }
2079
2080 static
2081 void lttng_create_syscall_event_if_missing(struct lttng_event_enabler *event_enabler)
2082 {
2083 int ret;
2084
2085 ret = lttng_syscalls_register_event(event_enabler, NULL);
2086 WARN_ON_ONCE(ret);
2087 }
2088
2089 static
2090 void lttng_create_syscall_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2091 {
2092 int ret;
2093
2094 ret = lttng_syscalls_register_event_notifier(event_notifier_enabler, NULL);
2095 WARN_ON_ONCE(ret);
2096 ret = lttng_syscals_create_matching_event_notifiers(event_notifier_enabler, NULL);
2097 WARN_ON_ONCE(ret);
2098 }
2099
2100 /*
2101 * Create struct lttng_event if it is missing and present in the list of
2102 * tracepoint probes.
2103 * Should be called with sessions mutex held.
2104 */
2105 static
2106 void lttng_create_event_if_missing(struct lttng_event_enabler *event_enabler)
2107 {
2108 switch (event_enabler->base.event_param.instrumentation) {
2109 case LTTNG_KERNEL_TRACEPOINT:
2110 lttng_create_tracepoint_event_if_missing(event_enabler);
2111 break;
2112 case LTTNG_KERNEL_SYSCALL:
2113 lttng_create_syscall_event_if_missing(event_enabler);
2114 break;
2115 default:
2116 WARN_ON_ONCE(1);
2117 break;
2118 }
2119 }
2120
2121 /*
2122 * Create events associated with an event_enabler (if not already present),
2123 * and add backward reference from the event to the enabler.
2124 * Should be called with sessions mutex held.
2125 */
2126 static
2127 int lttng_event_enabler_ref_events(struct lttng_event_enabler *event_enabler)
2128 {
2129 struct lttng_channel *chan = event_enabler->chan;
2130 struct lttng_session *session = event_enabler->chan->session;
2131 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(event_enabler);
2132 struct lttng_event *event;
2133
2134 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_SYSCALL &&
2135 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_SYSCALL_ABI_ALL &&
2136 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_SYSCALL_MATCH_NAME &&
2137 !strcmp(base_enabler->event_param.name, "*")) {
2138 int enabled = base_enabler->enabled;
2139 enum lttng_kernel_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2140
2141 if (entryexit == LTTNG_KERNEL_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2142 WRITE_ONCE(chan->syscall_all_entry, enabled);
2143
2144 if (entryexit == LTTNG_KERNEL_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2145 WRITE_ONCE(chan->syscall_all_exit, enabled);
2146 }
2147
2148 /* First ensure that probe events are created for this enabler. */
2149 lttng_create_event_if_missing(event_enabler);
2150
2151 /* For each event matching event_enabler in session event list. */
2152 list_for_each_entry(event, &session->events, list) {
2153 struct lttng_enabler_ref *enabler_ref;
2154
2155 if (!lttng_event_enabler_match_event(event_enabler, event))
2156 continue;
2157 enabler_ref = lttng_enabler_ref(&event->enablers_ref_head,
2158 lttng_event_enabler_as_enabler(event_enabler));
2159 if (!enabler_ref) {
2160 /*
2161 * If no backward ref, create it.
2162 * Add backward ref from event to event_enabler.
2163 */
2164 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2165 if (!enabler_ref)
2166 return -ENOMEM;
2167 enabler_ref->ref = lttng_event_enabler_as_enabler(event_enabler);
2168 list_add(&enabler_ref->node,
2169 &event->enablers_ref_head);
2170 }
2171
2172 /*
2173 * Link filter bytecodes if not linked yet.
2174 */
2175 lttng_enabler_link_bytecode(event->desc,
2176 lttng_static_ctx,
2177 &event->filter_bytecode_runtime_head,
2178 &lttng_event_enabler_as_enabler(event_enabler)->filter_bytecode_head);
2179
2180 /* TODO: merge event context. */
2181 }
2182 return 0;
2183 }
2184
2185 /*
2186 * Create struct lttng_event_notifier if it is missing and present in the list of
2187 * tracepoint probes.
2188 * Should be called with sessions mutex held.
2189 */
2190 static
2191 void lttng_create_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2192 {
2193 switch (event_notifier_enabler->base.event_param.instrumentation) {
2194 case LTTNG_KERNEL_TRACEPOINT:
2195 lttng_create_tracepoint_event_notifier_if_missing(event_notifier_enabler);
2196 break;
2197 case LTTNG_KERNEL_SYSCALL:
2198 lttng_create_syscall_event_notifier_if_missing(event_notifier_enabler);
2199 break;
2200 default:
2201 WARN_ON_ONCE(1);
2202 break;
2203 }
2204 }
2205
2206 /*
2207 * Create event_notifiers associated with a event_notifier enabler (if not already present).
2208 */
2209 static
2210 int lttng_event_notifier_enabler_ref_event_notifiers(
2211 struct lttng_event_notifier_enabler *event_notifier_enabler)
2212 {
2213 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2214 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2215 struct lttng_event_notifier *event_notifier;
2216
2217 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_SYSCALL &&
2218 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_SYSCALL_ABI_ALL &&
2219 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_SYSCALL_MATCH_NAME &&
2220 !strcmp(base_enabler->event_param.name, "*")) {
2221
2222 int enabled = base_enabler->enabled;
2223 enum lttng_kernel_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2224
2225 if (entryexit == LTTNG_KERNEL_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2226 WRITE_ONCE(event_notifier_group->syscall_all_entry, enabled);
2227
2228 if (entryexit == LTTNG_KERNEL_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2229 WRITE_ONCE(event_notifier_group->syscall_all_exit, enabled);
2230
2231 }
2232
2233 /* First ensure that probe event_notifiers are created for this enabler. */
2234 lttng_create_event_notifier_if_missing(event_notifier_enabler);
2235
2236 /* Link the created event_notifier with its associated enabler. */
2237 list_for_each_entry(event_notifier, &event_notifier_group->event_notifiers_head, list) {
2238 struct lttng_enabler_ref *enabler_ref;
2239
2240 if (!lttng_event_notifier_enabler_match_event_notifier(event_notifier_enabler, event_notifier))
2241 continue;
2242
2243 enabler_ref = lttng_enabler_ref(&event_notifier->enablers_ref_head,
2244 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2245 if (!enabler_ref) {
2246 /*
2247 * If no backward ref, create it.
2248 * Add backward ref from event_notifier to enabler.
2249 */
2250 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2251 if (!enabler_ref)
2252 return -ENOMEM;
2253
2254 enabler_ref->ref = lttng_event_notifier_enabler_as_enabler(
2255 event_notifier_enabler);
2256 list_add(&enabler_ref->node,
2257 &event_notifier->enablers_ref_head);
2258 }
2259
2260 /*
2261 * Link filter bytecodes if not linked yet.
2262 */
2263 lttng_enabler_link_bytecode(event_notifier->desc,
2264 lttng_static_ctx, &event_notifier->filter_bytecode_runtime_head,
2265 &lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->filter_bytecode_head);
2266
2267 /* Link capture bytecodes if not linked yet. */
2268 lttng_enabler_link_bytecode(event_notifier->desc,
2269 lttng_static_ctx, &event_notifier->capture_bytecode_runtime_head,
2270 &event_notifier_enabler->capture_bytecode_head);
2271
2272 event_notifier->num_captures = event_notifier_enabler->num_captures;
2273 }
2274 return 0;
2275 }
2276
2277 /*
2278 * Called at module load: connect the probe on all enablers matching
2279 * this event.
2280 * Called with sessions lock held.
2281 */
2282 int lttng_fix_pending_events(void)
2283 {
2284 struct lttng_session *session;
2285
2286 list_for_each_entry(session, &sessions, list)
2287 lttng_session_lazy_sync_event_enablers(session);
2288 return 0;
2289 }
2290
2291 static bool lttng_event_notifier_group_has_active_event_notifiers(
2292 struct lttng_event_notifier_group *event_notifier_group)
2293 {
2294 struct lttng_event_notifier_enabler *event_notifier_enabler;
2295
2296 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head,
2297 node) {
2298 if (event_notifier_enabler->base.enabled)
2299 return true;
2300 }
2301 return false;
2302 }
2303
2304 bool lttng_event_notifier_active(void)
2305 {
2306 struct lttng_event_notifier_group *event_notifier_group;
2307
2308 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2309 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2310 return true;
2311 }
2312 return false;
2313 }
2314
2315 int lttng_fix_pending_event_notifiers(void)
2316 {
2317 struct lttng_event_notifier_group *event_notifier_group;
2318
2319 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2320 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2321 return 0;
2322 }
2323
2324 struct lttng_event_enabler *lttng_event_enabler_create(
2325 enum lttng_enabler_format_type format_type,
2326 struct lttng_kernel_event *event_param,
2327 struct lttng_channel *chan)
2328 {
2329 struct lttng_event_enabler *event_enabler;
2330
2331 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2332 if (!event_enabler)
2333 return NULL;
2334 event_enabler->base.format_type = format_type;
2335 INIT_LIST_HEAD(&event_enabler->base.filter_bytecode_head);
2336 memcpy(&event_enabler->base.event_param, event_param,
2337 sizeof(event_enabler->base.event_param));
2338 event_enabler->chan = chan;
2339 /* ctx left NULL */
2340 event_enabler->base.enabled = 0;
2341 event_enabler->base.evtype = LTTNG_TYPE_ENABLER;
2342 mutex_lock(&sessions_mutex);
2343 list_add(&event_enabler->node, &event_enabler->chan->session->enablers_head);
2344 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2345 mutex_unlock(&sessions_mutex);
2346 return event_enabler;
2347 }
2348
2349 int lttng_event_enabler_enable(struct lttng_event_enabler *event_enabler)
2350 {
2351 mutex_lock(&sessions_mutex);
2352 lttng_event_enabler_as_enabler(event_enabler)->enabled = 1;
2353 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2354 mutex_unlock(&sessions_mutex);
2355 return 0;
2356 }
2357
2358 int lttng_event_enabler_disable(struct lttng_event_enabler *event_enabler)
2359 {
2360 mutex_lock(&sessions_mutex);
2361 lttng_event_enabler_as_enabler(event_enabler)->enabled = 0;
2362 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2363 mutex_unlock(&sessions_mutex);
2364 return 0;
2365 }
2366
2367 static
2368 int lttng_enabler_attach_filter_bytecode(struct lttng_enabler *enabler,
2369 struct lttng_kernel_filter_bytecode __user *bytecode)
2370 {
2371 struct lttng_bytecode_node *bytecode_node;
2372 uint32_t bytecode_len;
2373 int ret;
2374
2375 ret = get_user(bytecode_len, &bytecode->len);
2376 if (ret)
2377 return ret;
2378 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2379 GFP_KERNEL);
2380 if (!bytecode_node)
2381 return -ENOMEM;
2382 ret = copy_from_user(&bytecode_node->bc, bytecode,
2383 sizeof(*bytecode) + bytecode_len);
2384 if (ret)
2385 goto error_free;
2386
2387 bytecode_node->type = LTTNG_BYTECODE_NODE_TYPE_FILTER;
2388 bytecode_node->enabler = enabler;
2389 /* Enforce length based on allocated size */
2390 bytecode_node->bc.len = bytecode_len;
2391 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2392
2393 return 0;
2394
2395 error_free:
2396 lttng_kvfree(bytecode_node);
2397 return ret;
2398 }
2399
2400 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler *event_enabler,
2401 struct lttng_kernel_filter_bytecode __user *bytecode)
2402 {
2403 int ret;
2404 ret = lttng_enabler_attach_filter_bytecode(
2405 lttng_event_enabler_as_enabler(event_enabler), bytecode);
2406 if (ret)
2407 goto error;
2408
2409 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2410 return 0;
2411
2412 error:
2413 return ret;
2414 }
2415
2416 int lttng_event_add_callsite(struct lttng_event *event,
2417 struct lttng_kernel_event_callsite __user *callsite)
2418 {
2419
2420 switch (event->instrumentation) {
2421 case LTTNG_KERNEL_UPROBE:
2422 return lttng_uprobes_event_add_callsite(event, callsite);
2423 default:
2424 return -EINVAL;
2425 }
2426 }
2427
2428 int lttng_event_enabler_attach_context(struct lttng_event_enabler *event_enabler,
2429 struct lttng_kernel_context *context_param)
2430 {
2431 return -ENOSYS;
2432 }
2433
2434 static
2435 void lttng_enabler_destroy(struct lttng_enabler *enabler)
2436 {
2437 struct lttng_bytecode_node *filter_node, *tmp_filter_node;
2438
2439 /* Destroy filter bytecode */
2440 list_for_each_entry_safe(filter_node, tmp_filter_node,
2441 &enabler->filter_bytecode_head, node) {
2442 lttng_kvfree(filter_node);
2443 }
2444 }
2445
2446 static
2447 void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler)
2448 {
2449 lttng_enabler_destroy(lttng_event_enabler_as_enabler(event_enabler));
2450
2451 /* Destroy contexts */
2452 lttng_destroy_context(event_enabler->ctx);
2453
2454 list_del(&event_enabler->node);
2455 kfree(event_enabler);
2456 }
2457
2458 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2459 struct lttng_event_notifier_group *event_notifier_group,
2460 enum lttng_enabler_format_type format_type,
2461 struct lttng_kernel_event_notifier *event_notifier_param)
2462 {
2463 struct lttng_event_notifier_enabler *event_notifier_enabler;
2464
2465 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2466 if (!event_notifier_enabler)
2467 return NULL;
2468
2469 event_notifier_enabler->base.format_type = format_type;
2470 INIT_LIST_HEAD(&event_notifier_enabler->base.filter_bytecode_head);
2471 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2472
2473 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2474 event_notifier_enabler->num_captures = 0;
2475
2476 memcpy(&event_notifier_enabler->base.event_param, &event_notifier_param->event,
2477 sizeof(event_notifier_enabler->base.event_param));
2478 event_notifier_enabler->base.evtype = LTTNG_TYPE_ENABLER;
2479
2480 event_notifier_enabler->base.enabled = 0;
2481 event_notifier_enabler->base.user_token = event_notifier_param->event.token;
2482 event_notifier_enabler->group = event_notifier_group;
2483
2484 mutex_lock(&sessions_mutex);
2485 list_add(&event_notifier_enabler->node, &event_notifier_enabler->group->enablers_head);
2486 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2487
2488 mutex_unlock(&sessions_mutex);
2489
2490 return event_notifier_enabler;
2491 }
2492
2493 int lttng_event_notifier_enabler_enable(
2494 struct lttng_event_notifier_enabler *event_notifier_enabler)
2495 {
2496 mutex_lock(&sessions_mutex);
2497 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2498 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2499 mutex_unlock(&sessions_mutex);
2500 return 0;
2501 }
2502
2503 int lttng_event_notifier_enabler_disable(
2504 struct lttng_event_notifier_enabler *event_notifier_enabler)
2505 {
2506 mutex_lock(&sessions_mutex);
2507 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2508 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2509 mutex_unlock(&sessions_mutex);
2510 return 0;
2511 }
2512
2513 int lttng_event_notifier_enabler_attach_filter_bytecode(
2514 struct lttng_event_notifier_enabler *event_notifier_enabler,
2515 struct lttng_kernel_filter_bytecode __user *bytecode)
2516 {
2517 int ret;
2518
2519 ret = lttng_enabler_attach_filter_bytecode(
2520 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler),
2521 bytecode);
2522 if (ret)
2523 goto error;
2524
2525 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2526 return 0;
2527
2528 error:
2529 return ret;
2530 }
2531
2532 int lttng_event_notifier_enabler_attach_capture_bytecode(
2533 struct lttng_event_notifier_enabler *event_notifier_enabler,
2534 struct lttng_kernel_capture_bytecode __user *bytecode)
2535 {
2536 struct lttng_bytecode_node *bytecode_node;
2537 struct lttng_enabler *enabler =
2538 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2539 uint32_t bytecode_len;
2540 int ret;
2541
2542 ret = get_user(bytecode_len, &bytecode->len);
2543 if (ret)
2544 return ret;
2545
2546 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2547 GFP_KERNEL);
2548 if (!bytecode_node)
2549 return -ENOMEM;
2550
2551 ret = copy_from_user(&bytecode_node->bc, bytecode,
2552 sizeof(*bytecode) + bytecode_len);
2553 if (ret)
2554 goto error_free;
2555
2556 bytecode_node->type = LTTNG_BYTECODE_NODE_TYPE_CAPTURE;
2557 bytecode_node->enabler = enabler;
2558
2559 /* Enforce length based on allocated size */
2560 bytecode_node->bc.len = bytecode_len;
2561 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2562
2563 event_notifier_enabler->num_captures++;
2564
2565 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2566 goto end;
2567
2568 error_free:
2569 lttng_kvfree(bytecode_node);
2570 end:
2571 return ret;
2572 }
2573
2574 int lttng_event_notifier_add_callsite(struct lttng_event_notifier *event_notifier,
2575 struct lttng_kernel_event_callsite __user *callsite)
2576 {
2577
2578 switch (event_notifier->instrumentation) {
2579 case LTTNG_KERNEL_UPROBE:
2580 return lttng_uprobes_event_notifier_add_callsite(event_notifier,
2581 callsite);
2582 default:
2583 return -EINVAL;
2584 }
2585 }
2586
2587 int lttng_event_notifier_enabler_attach_context(
2588 struct lttng_event_notifier_enabler *event_notifier_enabler,
2589 struct lttng_kernel_context *context_param)
2590 {
2591 return -ENOSYS;
2592 }
2593
2594 static
2595 void lttng_event_notifier_enabler_destroy(
2596 struct lttng_event_notifier_enabler *event_notifier_enabler)
2597 {
2598 if (!event_notifier_enabler) {
2599 return;
2600 }
2601
2602 list_del(&event_notifier_enabler->node);
2603
2604 lttng_enabler_destroy(lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2605 kfree(event_notifier_enabler);
2606 }
2607
2608 /*
2609 * lttng_session_sync_event_enablers should be called just before starting a
2610 * session.
2611 * Should be called with sessions mutex held.
2612 */
2613 static
2614 void lttng_session_sync_event_enablers(struct lttng_session *session)
2615 {
2616 struct lttng_event_enabler *event_enabler;
2617 struct lttng_event *event;
2618
2619 list_for_each_entry(event_enabler, &session->enablers_head, node)
2620 lttng_event_enabler_ref_events(event_enabler);
2621 /*
2622 * For each event, if at least one of its enablers is enabled,
2623 * and its channel and session transient states are enabled, we
2624 * enable the event, else we disable it.
2625 */
2626 list_for_each_entry(event, &session->events, list) {
2627 struct lttng_enabler_ref *enabler_ref;
2628 struct lttng_bytecode_runtime *runtime;
2629 int enabled = 0, has_enablers_without_bytecode = 0;
2630
2631 switch (event->instrumentation) {
2632 case LTTNG_KERNEL_TRACEPOINT:
2633 case LTTNG_KERNEL_SYSCALL:
2634 /* Enable events */
2635 list_for_each_entry(enabler_ref,
2636 &event->enablers_ref_head, node) {
2637 if (enabler_ref->ref->enabled) {
2638 enabled = 1;
2639 break;
2640 }
2641 }
2642 break;
2643 default:
2644 /* Not handled with lazy sync. */
2645 continue;
2646 }
2647 /*
2648 * Enabled state is based on union of enablers, with
2649 * intesection of session and channel transient enable
2650 * states.
2651 */
2652 enabled = enabled && session->tstate && event->chan->tstate;
2653
2654 WRITE_ONCE(event->enabled, enabled);
2655 /*
2656 * Sync tracepoint registration with event enabled
2657 * state.
2658 */
2659 if (enabled) {
2660 register_event(event);
2661 } else {
2662 _lttng_event_unregister(event);
2663 }
2664
2665 /* Check if has enablers without bytecode enabled */
2666 list_for_each_entry(enabler_ref,
2667 &event->enablers_ref_head, node) {
2668 if (enabler_ref->ref->enabled
2669 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2670 has_enablers_without_bytecode = 1;
2671 break;
2672 }
2673 }
2674 event->has_enablers_without_bytecode =
2675 has_enablers_without_bytecode;
2676
2677 /* Enable filters */
2678 list_for_each_entry(runtime,
2679 &event->filter_bytecode_runtime_head, node)
2680 lttng_bytecode_filter_sync_state(runtime);
2681 }
2682 }
2683
2684 /*
2685 * Apply enablers to session events, adding events to session if need
2686 * be. It is required after each modification applied to an active
2687 * session, and right before session "start".
2688 * "lazy" sync means we only sync if required.
2689 * Should be called with sessions mutex held.
2690 */
2691 static
2692 void lttng_session_lazy_sync_event_enablers(struct lttng_session *session)
2693 {
2694 /* We can skip if session is not active */
2695 if (!session->active)
2696 return;
2697 lttng_session_sync_event_enablers(session);
2698 }
2699
2700 static
2701 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2702 {
2703 struct lttng_event_notifier_enabler *event_notifier_enabler;
2704 struct lttng_event_notifier *event_notifier;
2705
2706 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head, node)
2707 lttng_event_notifier_enabler_ref_event_notifiers(event_notifier_enabler);
2708
2709 /*
2710 * For each event_notifier, if at least one of its enablers is enabled,
2711 * we enable the event_notifier, else we disable it.
2712 */
2713 list_for_each_entry(event_notifier, &event_notifier_group->event_notifiers_head, list) {
2714 struct lttng_enabler_ref *enabler_ref;
2715 struct lttng_bytecode_runtime *runtime;
2716 int enabled = 0, has_enablers_without_bytecode = 0;
2717
2718 switch (event_notifier->instrumentation) {
2719 case LTTNG_KERNEL_TRACEPOINT:
2720 case LTTNG_KERNEL_SYSCALL:
2721 /* Enable event_notifiers */
2722 list_for_each_entry(enabler_ref,
2723 &event_notifier->enablers_ref_head, node) {
2724 if (enabler_ref->ref->enabled) {
2725 enabled = 1;
2726 break;
2727 }
2728 }
2729 break;
2730 default:
2731 /* Not handled with sync. */
2732 continue;
2733 }
2734
2735 WRITE_ONCE(event_notifier->enabled, enabled);
2736 /*
2737 * Sync tracepoint registration with event_notifier enabled
2738 * state.
2739 */
2740 if (enabled) {
2741 if (!event_notifier->registered)
2742 register_event_notifier(event_notifier);
2743 } else {
2744 if (event_notifier->registered)
2745 _lttng_event_notifier_unregister(event_notifier);
2746 }
2747
2748 /* Check if has enablers without bytecode enabled */
2749 list_for_each_entry(enabler_ref,
2750 &event_notifier->enablers_ref_head, node) {
2751 if (enabler_ref->ref->enabled
2752 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2753 has_enablers_without_bytecode = 1;
2754 break;
2755 }
2756 }
2757 event_notifier->has_enablers_without_bytecode =
2758 has_enablers_without_bytecode;
2759
2760 /* Enable filters */
2761 list_for_each_entry(runtime,
2762 &event_notifier->filter_bytecode_runtime_head, node)
2763 lttng_bytecode_filter_sync_state(runtime);
2764
2765 /* Enable captures */
2766 list_for_each_entry(runtime,
2767 &event_notifier->capture_bytecode_runtime_head, node)
2768 lttng_bytecode_capture_sync_state(runtime);
2769 }
2770 }
2771
2772 /*
2773 * Serialize at most one packet worth of metadata into a metadata
2774 * channel.
2775 * We grab the metadata cache mutex to get exclusive access to our metadata
2776 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2777 * allows us to do racy operations such as looking for remaining space left in
2778 * packet and write, since mutual exclusion protects us from concurrent writes.
2779 * Mutual exclusion on the metadata cache allow us to read the cache content
2780 * without racing against reallocation of the cache by updates.
2781 * Returns the number of bytes written in the channel, 0 if no data
2782 * was written and a negative value on error.
2783 */
2784 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2785 struct channel *chan, bool *coherent)
2786 {
2787 struct lib_ring_buffer_ctx ctx;
2788 int ret = 0;
2789 size_t len, reserve_len;
2790
2791 /*
2792 * Ensure we support mutiple get_next / put sequences followed by
2793 * put_next. The metadata cache lock protects reading the metadata
2794 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2795 * "flush" operations on the buffer invoked by different processes.
2796 * Moreover, since the metadata cache memory can be reallocated, we
2797 * need to have exclusive access against updates even though we only
2798 * read it.
2799 */
2800 mutex_lock(&stream->metadata_cache->lock);
2801 WARN_ON(stream->metadata_in < stream->metadata_out);
2802 if (stream->metadata_in != stream->metadata_out)
2803 goto end;
2804
2805 /* Metadata regenerated, change the version. */
2806 if (stream->metadata_cache->version != stream->version)
2807 stream->version = stream->metadata_cache->version;
2808
2809 len = stream->metadata_cache->metadata_written -
2810 stream->metadata_in;
2811 if (!len)
2812 goto end;
2813 reserve_len = min_t(size_t,
2814 stream->transport->ops.packet_avail_size(chan),
2815 len);
2816 lib_ring_buffer_ctx_init(&ctx, chan, NULL, reserve_len,
2817 sizeof(char), -1);
2818 /*
2819 * If reservation failed, return an error to the caller.
2820 */
2821 ret = stream->transport->ops.event_reserve(&ctx, 0);
2822 if (ret != 0) {
2823 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2824 stream->coherent = false;
2825 goto end;
2826 }
2827 stream->transport->ops.event_write(&ctx,
2828 stream->metadata_cache->data + stream->metadata_in,
2829 reserve_len);
2830 stream->transport->ops.event_commit(&ctx);
2831 stream->metadata_in += reserve_len;
2832 if (reserve_len < len)
2833 stream->coherent = false;
2834 else
2835 stream->coherent = true;
2836 ret = reserve_len;
2837
2838 end:
2839 if (coherent)
2840 *coherent = stream->coherent;
2841 mutex_unlock(&stream->metadata_cache->lock);
2842 return ret;
2843 }
2844
2845 static
2846 void lttng_metadata_begin(struct lttng_session *session)
2847 {
2848 if (atomic_inc_return(&session->metadata_cache->producing) == 1)
2849 mutex_lock(&session->metadata_cache->lock);
2850 }
2851
2852 static
2853 void lttng_metadata_end(struct lttng_session *session)
2854 {
2855 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
2856 if (atomic_dec_return(&session->metadata_cache->producing) == 0) {
2857 struct lttng_metadata_stream *stream;
2858
2859 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
2860 wake_up_interruptible(&stream->read_wait);
2861 mutex_unlock(&session->metadata_cache->lock);
2862 }
2863 }
2864
2865 /*
2866 * Write the metadata to the metadata cache.
2867 * Must be called with sessions_mutex held.
2868 * The metadata cache lock protects us from concurrent read access from
2869 * thread outputting metadata content to ring buffer.
2870 * The content of the printf is printed as a single atomic metadata
2871 * transaction.
2872 */
2873 int lttng_metadata_printf(struct lttng_session *session,
2874 const char *fmt, ...)
2875 {
2876 char *str;
2877 size_t len;
2878 va_list ap;
2879
2880 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
2881
2882 va_start(ap, fmt);
2883 str = kvasprintf(GFP_KERNEL, fmt, ap);
2884 va_end(ap);
2885 if (!str)
2886 return -ENOMEM;
2887
2888 len = strlen(str);
2889 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
2890 if (session->metadata_cache->metadata_written + len >
2891 session->metadata_cache->cache_alloc) {
2892 char *tmp_cache_realloc;
2893 unsigned int tmp_cache_alloc_size;
2894
2895 tmp_cache_alloc_size = max_t(unsigned int,
2896 session->metadata_cache->cache_alloc + len,
2897 session->metadata_cache->cache_alloc << 1);
2898 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
2899 if (!tmp_cache_realloc)
2900 goto err;
2901 if (session->metadata_cache->data) {
2902 memcpy(tmp_cache_realloc,
2903 session->metadata_cache->data,
2904 session->metadata_cache->cache_alloc);
2905 vfree(session->metadata_cache->data);
2906 }
2907
2908 session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
2909 session->metadata_cache->data = tmp_cache_realloc;
2910 }
2911 memcpy(session->metadata_cache->data +
2912 session->metadata_cache->metadata_written,
2913 str, len);
2914 session->metadata_cache->metadata_written += len;
2915 kfree(str);
2916
2917 return 0;
2918
2919 err:
2920 kfree(str);
2921 return -ENOMEM;
2922 }
2923
2924 static
2925 int print_tabs(struct lttng_session *session, size_t nesting)
2926 {
2927 size_t i;
2928
2929 for (i = 0; i < nesting; i++) {
2930 int ret;
2931
2932 ret = lttng_metadata_printf(session, " ");
2933 if (ret) {
2934 return ret;
2935 }
2936 }
2937 return 0;
2938 }
2939
2940 static
2941 int lttng_field_name_statedump(struct lttng_session *session,
2942 const struct lttng_event_field *field,
2943 size_t nesting)
2944 {
2945 return lttng_metadata_printf(session, " _%s;\n", field->name);
2946 }
2947
2948 static
2949 int _lttng_integer_type_statedump(struct lttng_session *session,
2950 const struct lttng_type *type,
2951 size_t nesting)
2952 {
2953 int ret;
2954
2955 WARN_ON_ONCE(type->atype != atype_integer);
2956 ret = print_tabs(session, nesting);
2957 if (ret)
2958 return ret;
2959 ret = lttng_metadata_printf(session,
2960 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
2961 type->u.integer.size,
2962 type->u.integer.alignment,
2963 type->u.integer.signedness,
2964 (type->u.integer.encoding == lttng_encode_none)
2965 ? "none"
2966 : (type->u.integer.encoding == lttng_encode_UTF8)
2967 ? "UTF8"
2968 : "ASCII",
2969 type->u.integer.base,
2970 #if __BYTE_ORDER == __BIG_ENDIAN
2971 type->u.integer.reverse_byte_order ? " byte_order = le;" : ""
2972 #else
2973 type->u.integer.reverse_byte_order ? " byte_order = be;" : ""
2974 #endif
2975 );
2976 return ret;
2977 }
2978
2979 /*
2980 * Must be called with sessions_mutex held.
2981 */
2982 static
2983 int _lttng_struct_type_statedump(struct lttng_session *session,
2984 const struct lttng_type *type,
2985 size_t nesting)
2986 {
2987 int ret;
2988 uint32_t i, nr_fields;
2989 unsigned int alignment;
2990
2991 WARN_ON_ONCE(type->atype != atype_struct_nestable);
2992
2993 ret = print_tabs(session, nesting);
2994 if (ret)
2995 return ret;
2996 ret = lttng_metadata_printf(session,
2997 "struct {\n");
2998 if (ret)
2999 return ret;
3000 nr_fields = type->u.struct_nestable.nr_fields;
3001 for (i = 0; i < nr_fields; i++) {
3002 const struct lttng_event_field *iter_field;
3003
3004 iter_field = &type->u.struct_nestable.fields[i];
3005 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
3006 if (ret)
3007 return ret;
3008 }
3009 ret = print_tabs(session, nesting);
3010 if (ret)
3011 return ret;
3012 alignment = type->u.struct_nestable.alignment;
3013 if (alignment) {
3014 ret = lttng_metadata_printf(session,
3015 "} align(%u)",
3016 alignment);
3017 } else {
3018 ret = lttng_metadata_printf(session,
3019 "}");
3020 }
3021 return ret;
3022 }
3023
3024 /*
3025 * Must be called with sessions_mutex held.
3026 */
3027 static
3028 int _lttng_struct_field_statedump(struct lttng_session *session,
3029 const struct lttng_event_field *field,
3030 size_t nesting)
3031 {
3032 int ret;
3033
3034 ret = _lttng_struct_type_statedump(session,
3035 &field->type, nesting);
3036 if (ret)
3037 return ret;
3038 return lttng_field_name_statedump(session, field, nesting);
3039 }
3040
3041 /*
3042 * Must be called with sessions_mutex held.
3043 */
3044 static
3045 int _lttng_variant_type_statedump(struct lttng_session *session,
3046 const struct lttng_type *type,
3047 size_t nesting)
3048 {
3049 int ret;
3050 uint32_t i, nr_choices;
3051
3052 WARN_ON_ONCE(type->atype != atype_variant_nestable);
3053 /*
3054 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3055 */
3056 if (type->u.variant_nestable.alignment != 0)
3057 return -EINVAL;
3058 ret = print_tabs(session, nesting);
3059 if (ret)
3060 return ret;
3061 ret = lttng_metadata_printf(session,
3062 "variant <_%s> {\n",
3063 type->u.variant_nestable.tag_name);
3064 if (ret)
3065 return ret;
3066 nr_choices = type->u.variant_nestable.nr_choices;
3067 for (i = 0; i < nr_choices; i++) {
3068 const struct lttng_event_field *iter_field;
3069
3070 iter_field = &type->u.variant_nestable.choices[i];
3071 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
3072 if (ret)
3073 return ret;
3074 }
3075 ret = print_tabs(session, nesting);
3076 if (ret)
3077 return ret;
3078 ret = lttng_metadata_printf(session,
3079 "}");
3080 return ret;
3081 }
3082
3083 /*
3084 * Must be called with sessions_mutex held.
3085 */
3086 static
3087 int _lttng_variant_field_statedump(struct lttng_session *session,
3088 const struct lttng_event_field *field,
3089 size_t nesting)
3090 {
3091 int ret;
3092
3093 ret = _lttng_variant_type_statedump(session,
3094 &field->type, nesting);
3095 if (ret)
3096 return ret;
3097 return lttng_field_name_statedump(session, field, nesting);
3098 }
3099
3100 /*
3101 * Must be called with sessions_mutex held.
3102 */
3103 static
3104 int _lttng_array_field_statedump(struct lttng_session *session,
3105 const struct lttng_event_field *field,
3106 size_t nesting)
3107 {
3108 int ret;
3109 const struct lttng_type *elem_type;
3110
3111 WARN_ON_ONCE(field->type.atype != atype_array_nestable);
3112
3113 if (field->type.u.array_nestable.alignment) {
3114 ret = print_tabs(session, nesting);
3115 if (ret)
3116 return ret;
3117 ret = lttng_metadata_printf(session,
3118 "struct { } align(%u) _%s_padding;\n",
3119 field->type.u.array_nestable.alignment * CHAR_BIT,
3120 field->name);
3121 if (ret)
3122 return ret;
3123 }
3124 /*
3125 * Nested compound types: Only array of structures and variants are
3126 * currently supported.
3127 */
3128 elem_type = field->type.u.array_nestable.elem_type;
3129 switch (elem_type->atype) {
3130 case atype_integer:
3131 case atype_struct_nestable:
3132 case atype_variant_nestable:
3133 ret = _lttng_type_statedump(session, elem_type, nesting);
3134 if (ret)
3135 return ret;
3136 break;
3137
3138 default:
3139 return -EINVAL;
3140 }
3141 ret = lttng_metadata_printf(session,
3142 " _%s[%u];\n",
3143 field->name,
3144 field->type.u.array_nestable.length);
3145 return ret;
3146 }
3147
3148 /*
3149 * Must be called with sessions_mutex held.
3150 */
3151 static
3152 int _lttng_sequence_field_statedump(struct lttng_session *session,
3153 const struct lttng_event_field *field,
3154 size_t nesting)
3155 {
3156 int ret;
3157 const char *length_name;
3158 const struct lttng_type *elem_type;
3159
3160 WARN_ON_ONCE(field->type.atype != atype_sequence_nestable);
3161
3162 length_name = field->type.u.sequence_nestable.length_name;
3163
3164 if (field->type.u.sequence_nestable.alignment) {
3165 ret = print_tabs(session, nesting);
3166 if (ret)
3167 return ret;
3168 ret = lttng_metadata_printf(session,
3169 "struct { } align(%u) _%s_padding;\n",
3170 field->type.u.sequence_nestable.alignment * CHAR_BIT,
3171 field->name);
3172 if (ret)
3173 return ret;
3174 }
3175
3176 /*
3177 * Nested compound types: Only array of structures and variants are
3178 * currently supported.
3179 */
3180 elem_type = field->type.u.sequence_nestable.elem_type;
3181 switch (elem_type->atype) {
3182 case atype_integer:
3183 case atype_struct_nestable:
3184 case atype_variant_nestable:
3185 ret = _lttng_type_statedump(session, elem_type, nesting);
3186 if (ret)
3187 return ret;
3188 break;
3189
3190 default:
3191 return -EINVAL;
3192 }
3193 ret = lttng_metadata_printf(session,
3194 " _%s[ _%s ];\n",
3195 field->name,
3196 field->type.u.sequence_nestable.length_name);
3197 return ret;
3198 }
3199
3200 /*
3201 * Must be called with sessions_mutex held.
3202 */
3203 static
3204 int _lttng_enum_type_statedump(struct lttng_session *session,
3205 const struct lttng_type *type,
3206 size_t nesting)
3207 {
3208 const struct lttng_enum_desc *enum_desc;
3209 const struct lttng_type *container_type;
3210 int ret;
3211 unsigned int i, nr_entries;
3212
3213 container_type = type->u.enum_nestable.container_type;
3214 if (container_type->atype != atype_integer) {
3215 ret = -EINVAL;
3216 goto end;
3217 }
3218 enum_desc = type->u.enum_nestable.desc;
3219 nr_entries = enum_desc->nr_entries;
3220
3221 ret = print_tabs(session, nesting);
3222 if (ret)
3223 goto end;
3224 ret = lttng_metadata_printf(session, "enum : ");
3225 if (ret)
3226 goto end;
3227 ret = _lttng_integer_type_statedump(session, container_type, 0);
3228 if (ret)
3229 goto end;
3230 ret = lttng_metadata_printf(session, " {\n");
3231 if (ret)
3232 goto end;
3233 /* Dump all entries */
3234 for (i = 0; i < nr_entries; i++) {
3235 const struct lttng_enum_entry *entry = &enum_desc->entries[i];
3236 int j, len;
3237
3238 ret = print_tabs(session, nesting + 1);
3239 if (ret)
3240 goto end;
3241 ret = lttng_metadata_printf(session,
3242 "\"");
3243 if (ret)
3244 goto end;
3245 len = strlen(entry->string);
3246 /* Escape the character '"' */
3247 for (j = 0; j < len; j++) {
3248 char c = entry->string[j];
3249
3250 switch (c) {
3251 case '"':
3252 ret = lttng_metadata_printf(session,
3253 "\\\"");
3254 break;
3255 case '\\':
3256 ret = lttng_metadata_printf(session,
3257 "\\\\");
3258 break;
3259 default:
3260 ret = lttng_metadata_printf(session,
3261 "%c", c);
3262 break;
3263 }
3264 if (ret)
3265 goto end;
3266 }
3267 ret = lttng_metadata_printf(session, "\"");
3268 if (ret)
3269 goto end;
3270
3271 if (entry->options.is_auto) {
3272 ret = lttng_metadata_printf(session, ",\n");
3273 if (ret)
3274 goto end;
3275 } else {
3276 ret = lttng_metadata_printf(session,
3277 " = ");
3278 if (ret)
3279 goto end;
3280 if (entry->start.signedness)
3281 ret = lttng_metadata_printf(session,
3282 "%lld", (long long) entry->start.value);
3283 else
3284 ret = lttng_metadata_printf(session,
3285 "%llu", entry->start.value);
3286 if (ret)
3287 goto end;
3288 if (entry->start.signedness == entry->end.signedness &&
3289 entry->start.value
3290 == entry->end.value) {
3291 ret = lttng_metadata_printf(session,
3292 ",\n");
3293 } else {
3294 if (entry->end.signedness) {
3295 ret = lttng_metadata_printf(session,
3296 " ... %lld,\n",
3297 (long long) entry->end.value);
3298 } else {
3299 ret = lttng_metadata_printf(session,
3300 " ... %llu,\n",
3301 entry->end.value);
3302 }
3303 }
3304 if (ret)
3305 goto end;
3306 }
3307 }
3308 ret = print_tabs(session, nesting);
3309 if (ret)
3310 goto end;
3311 ret = lttng_metadata_printf(session, "}");
3312 end:
3313 return ret;
3314 }
3315
3316 /*
3317 * Must be called with sessions_mutex held.
3318 */
3319 static
3320 int _lttng_enum_field_statedump(struct lttng_session *session,
3321 const struct lttng_event_field *field,
3322 size_t nesting)
3323 {
3324 int ret;
3325
3326 ret = _lttng_enum_type_statedump(session, &field->type, nesting);
3327 if (ret)
3328 return ret;
3329 return lttng_field_name_statedump(session, field, nesting);
3330 }
3331
3332 static
3333 int _lttng_integer_field_statedump(struct lttng_session *session,
3334 const struct lttng_event_field *field,
3335 size_t nesting)
3336 {
3337 int ret;
3338
3339 ret = _lttng_integer_type_statedump(session, &field->type, nesting);
3340 if (ret)
3341 return ret;
3342 return lttng_field_name_statedump(session, field, nesting);
3343 }
3344
3345 static
3346 int _lttng_string_type_statedump(struct lttng_session *session,
3347 const struct lttng_type *type,
3348 size_t nesting)
3349 {
3350 int ret;
3351
3352 WARN_ON_ONCE(type->atype != atype_string);
3353 /* Default encoding is UTF8 */
3354 ret = print_tabs(session, nesting);
3355 if (ret)
3356 return ret;
3357 ret = lttng_metadata_printf(session,
3358 "string%s",
3359 type->u.string.encoding == lttng_encode_ASCII ?
3360 " { encoding = ASCII; }" : "");
3361 return ret;
3362 }
3363
3364 static
3365 int _lttng_string_field_statedump(struct lttng_session *session,
3366 const struct lttng_event_field *field,
3367 size_t nesting)
3368 {
3369 int ret;
3370
3371 WARN_ON_ONCE(field->type.atype != atype_string);
3372 ret = _lttng_string_type_statedump(session, &field->type, nesting);
3373 if (ret)
3374 return ret;
3375 return lttng_field_name_statedump(session, field, nesting);
3376 }
3377
3378 /*
3379 * Must be called with sessions_mutex held.
3380 */
3381 static
3382 int _lttng_type_statedump(struct lttng_session *session,
3383 const struct lttng_type *type,
3384 size_t nesting)
3385 {
3386 int ret = 0;
3387
3388 switch (type->atype) {
3389 case atype_integer:
3390 ret = _lttng_integer_type_statedump(session, type, nesting);
3391 break;
3392 case atype_enum_nestable:
3393 ret = _lttng_enum_type_statedump(session, type, nesting);
3394 break;
3395 case atype_string:
3396 ret = _lttng_string_type_statedump(session, type, nesting);
3397 break;
3398 case atype_struct_nestable:
3399 ret = _lttng_struct_type_statedump(session, type, nesting);
3400 break;
3401 case atype_variant_nestable:
3402 ret = _lttng_variant_type_statedump(session, type, nesting);
3403 break;
3404
3405 /* Nested arrays and sequences are not supported yet. */
3406 case atype_array_nestable:
3407 case atype_sequence_nestable:
3408 default:
3409 WARN_ON_ONCE(1);
3410 return -EINVAL;
3411 }
3412 return ret;
3413 }
3414
3415 /*
3416 * Must be called with sessions_mutex held.
3417 */
3418 static
3419 int _lttng_field_statedump(struct lttng_session *session,
3420 const struct lttng_event_field *field,
3421 size_t nesting)
3422 {
3423 int ret = 0;
3424
3425 switch (field->type.atype) {
3426 case atype_integer:
3427 ret = _lttng_integer_field_statedump(session, field, nesting);
3428 break;
3429 case atype_enum_nestable:
3430 ret = _lttng_enum_field_statedump(session, field, nesting);
3431 break;
3432 case atype_string:
3433 ret = _lttng_string_field_statedump(session, field, nesting);
3434 break;
3435 case atype_struct_nestable:
3436 ret = _lttng_struct_field_statedump(session, field, nesting);
3437 break;
3438 case atype_array_nestable:
3439 ret = _lttng_array_field_statedump(session, field, nesting);
3440 break;
3441 case atype_sequence_nestable:
3442 ret = _lttng_sequence_field_statedump(session, field, nesting);
3443 break;
3444 case atype_variant_nestable:
3445 ret = _lttng_variant_field_statedump(session, field, nesting);
3446 break;
3447
3448 default:
3449 WARN_ON_ONCE(1);
3450 return -EINVAL;
3451 }
3452 return ret;
3453 }
3454
3455 static
3456 int _lttng_context_metadata_statedump(struct lttng_session *session,
3457 struct lttng_ctx *ctx)
3458 {
3459 int ret = 0;
3460 int i;
3461
3462 if (!ctx)
3463 return 0;
3464 for (i = 0; i < ctx->nr_fields; i++) {
3465 const struct lttng_ctx_field *field = &ctx->fields[i];
3466
3467 ret = _lttng_field_statedump(session, &field->event_field, 2);
3468 if (ret)
3469 return ret;
3470 }
3471 return ret;
3472 }
3473
3474 static
3475 int _lttng_fields_metadata_statedump(struct lttng_session *session,
3476 struct lttng_event *event)
3477 {
3478 const struct lttng_event_desc *desc = event->desc;
3479 int ret = 0;
3480 int i;
3481
3482 for (i = 0; i < desc->nr_fields; i++) {
3483 const struct lttng_event_field *field = &desc->fields[i];
3484
3485 ret = _lttng_field_statedump(session, field, 2);
3486 if (ret)
3487 return ret;
3488 }
3489 return ret;
3490 }
3491
3492 /*
3493 * Must be called with sessions_mutex held.
3494 * The entire event metadata is printed as a single atomic metadata
3495 * transaction.
3496 */
3497 static
3498 int _lttng_event_metadata_statedump(struct lttng_session *session,
3499 struct lttng_channel *chan,
3500 struct lttng_event *event)
3501 {
3502 int ret = 0;
3503
3504 if (event->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3505 return 0;
3506 if (chan->channel_type == METADATA_CHANNEL)
3507 return 0;
3508
3509 lttng_metadata_begin(session);
3510
3511 ret = lttng_metadata_printf(session,
3512 "event {\n"
3513 " name = \"%s\";\n"
3514 " id = %u;\n"
3515 " stream_id = %u;\n",
3516 event->desc->name,
3517 event->id,
3518 event->chan->id);
3519 if (ret)
3520 goto end;
3521
3522 if (event->ctx) {
3523 ret = lttng_metadata_printf(session,
3524 " context := struct {\n");
3525 if (ret)
3526 goto end;
3527 }
3528 ret = _lttng_context_metadata_statedump(session, event->ctx);
3529 if (ret)
3530 goto end;
3531 if (event->ctx) {
3532 ret = lttng_metadata_printf(session,
3533 " };\n");
3534 if (ret)
3535 goto end;
3536 }
3537
3538 ret = lttng_metadata_printf(session,
3539 " fields := struct {\n"
3540 );
3541 if (ret)
3542 goto end;
3543
3544 ret = _lttng_fields_metadata_statedump(session, event);
3545 if (ret)
3546 goto end;
3547
3548 /*
3549 * LTTng space reservation can only reserve multiples of the
3550 * byte size.
3551 */
3552 ret = lttng_metadata_printf(session,
3553 " };\n"
3554 "};\n\n");
3555 if (ret)
3556 goto end;
3557
3558 event->metadata_dumped = 1;
3559 end:
3560 lttng_metadata_end(session);
3561 return ret;
3562
3563 }
3564
3565 /*
3566 * Must be called with sessions_mutex held.
3567 * The entire channel metadata is printed as a single atomic metadata
3568 * transaction.
3569 */
3570 static
3571 int _lttng_channel_metadata_statedump(struct lttng_session *session,
3572 struct lttng_channel *chan)
3573 {
3574 int ret = 0;
3575
3576 if (chan->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3577 return 0;
3578
3579 if (chan->channel_type == METADATA_CHANNEL)
3580 return 0;
3581
3582 lttng_metadata_begin(session);
3583
3584 WARN_ON_ONCE(!chan->header_type);
3585 ret = lttng_metadata_printf(session,
3586 "stream {\n"
3587 " id = %u;\n"
3588 " event.header := %s;\n"
3589 " packet.context := struct packet_context;\n",
3590 chan->id,
3591 chan->header_type == 1 ? "struct event_header_compact" :
3592 "struct event_header_large");
3593 if (ret)
3594 goto end;
3595
3596 if (chan->ctx) {
3597 ret = lttng_metadata_printf(session,
3598 " event.context := struct {\n");
3599 if (ret)
3600 goto end;
3601 }
3602 ret = _lttng_context_metadata_statedump(session, chan->ctx);
3603 if (ret)
3604 goto end;
3605 if (chan->ctx) {
3606 ret = lttng_metadata_printf(session,
3607 " };\n");
3608 if (ret)
3609 goto end;
3610 }
3611
3612 ret = lttng_metadata_printf(session,
3613 "};\n\n");
3614
3615 chan->metadata_dumped = 1;
3616 end:
3617 lttng_metadata_end(session);
3618 return ret;
3619 }
3620
3621 /*
3622 * Must be called with sessions_mutex held.
3623 */
3624 static
3625 int _lttng_stream_packet_context_declare(struct lttng_session *session)
3626 {
3627 return lttng_metadata_printf(session,
3628 "struct packet_context {\n"
3629 " uint64_clock_monotonic_t timestamp_begin;\n"
3630 " uint64_clock_monotonic_t timestamp_end;\n"
3631 " uint64_t content_size;\n"
3632 " uint64_t packet_size;\n"
3633 " uint64_t packet_seq_num;\n"
3634 " unsigned long events_discarded;\n"
3635 " uint32_t cpu_id;\n"
3636 "};\n\n"
3637 );
3638 }
3639
3640 /*
3641 * Compact header:
3642 * id: range: 0 - 30.
3643 * id 31 is reserved to indicate an extended header.
3644 *
3645 * Large header:
3646 * id: range: 0 - 65534.
3647 * id 65535 is reserved to indicate an extended header.
3648 *
3649 * Must be called with sessions_mutex held.
3650 */
3651 static
3652 int _lttng_event_header_declare(struct lttng_session *session)
3653 {
3654 return lttng_metadata_printf(session,
3655 "struct event_header_compact {\n"
3656 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3657 " variant <id> {\n"
3658 " struct {\n"
3659 " uint27_clock_monotonic_t timestamp;\n"
3660 " } compact;\n"
3661 " struct {\n"
3662 " uint32_t id;\n"
3663 " uint64_clock_monotonic_t timestamp;\n"
3664 " } extended;\n"
3665 " } v;\n"
3666 "} align(%u);\n"
3667 "\n"
3668 "struct event_header_large {\n"
3669 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3670 " variant <id> {\n"
3671 " struct {\n"
3672 " uint32_clock_monotonic_t timestamp;\n"
3673 " } compact;\n"
3674 " struct {\n"
3675 " uint32_t id;\n"
3676 " uint64_clock_monotonic_t timestamp;\n"
3677 " } extended;\n"
3678 " } v;\n"
3679 "} align(%u);\n\n",
3680 lttng_alignof(uint32_t) * CHAR_BIT,
3681 lttng_alignof(uint16_t) * CHAR_BIT
3682 );
3683 }
3684
3685 /*
3686 * Approximation of NTP time of day to clock monotonic correlation,
3687 * taken at start of trace.
3688 * Yes, this is only an approximation. Yes, we can (and will) do better
3689 * in future versions.
3690 * This function may return a negative offset. It may happen if the
3691 * system sets the REALTIME clock to 0 after boot.
3692 *
3693 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3694 * y2038 compliant.
3695 */
3696 static
3697 int64_t measure_clock_offset(void)
3698 {
3699 uint64_t monotonic_avg, monotonic[2], realtime;
3700 uint64_t tcf = trace_clock_freq();
3701 int64_t offset;
3702 unsigned long flags;
3703 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3704 struct timespec64 rts = { 0, 0 };
3705 #else
3706 struct timespec rts = { 0, 0 };
3707 #endif
3708
3709 /* Disable interrupts to increase correlation precision. */
3710 local_irq_save(flags);
3711 monotonic[0] = trace_clock_read64();
3712 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3713 ktime_get_real_ts64(&rts);
3714 #else
3715 getnstimeofday(&rts);
3716 #endif
3717 monotonic[1] = trace_clock_read64();
3718 local_irq_restore(flags);
3719
3720 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3721 realtime = (uint64_t) rts.tv_sec * tcf;
3722 if (tcf == NSEC_PER_SEC) {
3723 realtime += rts.tv_nsec;
3724 } else {
3725 uint64_t n = rts.tv_nsec * tcf;
3726
3727 do_div(n, NSEC_PER_SEC);
3728 realtime += n;
3729 }
3730 offset = (int64_t) realtime - monotonic_avg;
3731 return offset;
3732 }
3733
3734 static
3735 int print_escaped_ctf_string(struct lttng_session *session, const char *string)
3736 {
3737 int ret = 0;
3738 size_t i;
3739 char cur;
3740
3741 i = 0;
3742 cur = string[i];
3743 while (cur != '\0') {
3744 switch (cur) {
3745 case '\n':
3746 ret = lttng_metadata_printf(session, "%s", "\\n");
3747 break;
3748 case '\\':
3749 case '"':
3750 ret = lttng_metadata_printf(session, "%c", '\\');
3751 if (ret)
3752 goto error;
3753 /* We still print the current char */
3754 /* Fallthrough */
3755 default:
3756 ret = lttng_metadata_printf(session, "%c", cur);
3757 break;
3758 }
3759
3760 if (ret)
3761 goto error;
3762
3763 cur = string[++i];
3764 }
3765 error:
3766 return ret;
3767 }
3768
3769 static
3770 int print_metadata_escaped_field(struct lttng_session *session, const char *field,
3771 const char *field_value)
3772 {
3773 int ret;
3774
3775 ret = lttng_metadata_printf(session, " %s = \"", field);
3776 if (ret)
3777 goto error;
3778
3779 ret = print_escaped_ctf_string(session, field_value);
3780 if (ret)
3781 goto error;
3782
3783 ret = lttng_metadata_printf(session, "\";\n");
3784
3785 error:
3786 return ret;
3787 }
3788
3789 /*
3790 * Output metadata into this session's metadata buffers.
3791 * Must be called with sessions_mutex held.
3792 */
3793 static
3794 int _lttng_session_metadata_statedump(struct lttng_session *session)
3795 {
3796 unsigned char *uuid_c = session->uuid.b;
3797 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3798 const char *product_uuid;
3799 struct lttng_channel *chan;
3800 struct lttng_event *event;
3801 int ret = 0;
3802
3803 if (!LTTNG_READ_ONCE(session->active))
3804 return 0;
3805
3806 lttng_metadata_begin(session);
3807
3808 if (session->metadata_dumped)
3809 goto skip_session;
3810
3811 snprintf(uuid_s, sizeof(uuid_s),
3812 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3813 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3814 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3815 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3816 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3817
3818 ret = lttng_metadata_printf(session,
3819 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3820 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3821 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3822 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3823 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3824 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3825 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3826 "\n"
3827 "trace {\n"
3828 " major = %u;\n"
3829 " minor = %u;\n"
3830 " uuid = \"%s\";\n"
3831 " byte_order = %s;\n"
3832 " packet.header := struct {\n"
3833 " uint32_t magic;\n"
3834 " uint8_t uuid[16];\n"
3835 " uint32_t stream_id;\n"
3836 " uint64_t stream_instance_id;\n"
3837 " };\n"
3838 "};\n\n",
3839 lttng_alignof(uint8_t) * CHAR_BIT,
3840 lttng_alignof(uint16_t) * CHAR_BIT,
3841 lttng_alignof(uint32_t) * CHAR_BIT,
3842 lttng_alignof(uint64_t) * CHAR_BIT,
3843 sizeof(unsigned long) * CHAR_BIT,
3844 lttng_alignof(unsigned long) * CHAR_BIT,
3845 CTF_SPEC_MAJOR,
3846 CTF_SPEC_MINOR,
3847 uuid_s,
3848 #if __BYTE_ORDER == __BIG_ENDIAN
3849 "be"
3850 #else
3851 "le"
3852 #endif
3853 );
3854 if (ret)
3855 goto end;
3856
3857 ret = lttng_metadata_printf(session,
3858 "env {\n"
3859 " hostname = \"%s\";\n"
3860 " domain = \"kernel\";\n"
3861 " sysname = \"%s\";\n"
3862 " kernel_release = \"%s\";\n"
3863 " kernel_version = \"%s\";\n"
3864 " tracer_name = \"lttng-modules\";\n"
3865 " tracer_major = %d;\n"
3866 " tracer_minor = %d;\n"
3867 " tracer_patchlevel = %d;\n"
3868 " trace_buffering_scheme = \"global\";\n",
3869 current->nsproxy->uts_ns->name.nodename,
3870 utsname()->sysname,
3871 utsname()->release,
3872 utsname()->version,
3873 LTTNG_MODULES_MAJOR_VERSION,
3874 LTTNG_MODULES_MINOR_VERSION,
3875 LTTNG_MODULES_PATCHLEVEL_VERSION
3876 );
3877 if (ret)
3878 goto end;
3879
3880 ret = print_metadata_escaped_field(session, "trace_name", session->name);
3881 if (ret)
3882 goto end;
3883 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
3884 session->creation_time);
3885 if (ret)
3886 goto end;
3887
3888 /* Add the product UUID to the 'env' section */
3889 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
3890 if (product_uuid) {
3891 ret = lttng_metadata_printf(session,
3892 " product_uuid = \"%s\";\n",
3893 product_uuid
3894 );
3895 if (ret)
3896 goto end;
3897 }
3898
3899 /* Close the 'env' section */
3900 ret = lttng_metadata_printf(session, "};\n\n");
3901 if (ret)
3902 goto end;
3903
3904 ret = lttng_metadata_printf(session,
3905 "clock {\n"
3906 " name = \"%s\";\n",
3907 trace_clock_name()
3908 );
3909 if (ret)
3910 goto end;
3911
3912 if (!trace_clock_uuid(clock_uuid_s)) {
3913 ret = lttng_metadata_printf(session,
3914 " uuid = \"%s\";\n",
3915 clock_uuid_s
3916 );
3917 if (ret)
3918 goto end;
3919 }
3920
3921 ret = lttng_metadata_printf(session,
3922 " description = \"%s\";\n"
3923 " freq = %llu; /* Frequency, in Hz */\n"
3924 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
3925 " offset = %lld;\n"
3926 "};\n\n",
3927 trace_clock_description(),
3928 (unsigned long long) trace_clock_freq(),
3929 (long long) measure_clock_offset()
3930 );
3931 if (ret)
3932 goto end;
3933
3934 ret = lttng_metadata_printf(session,
3935 "typealias integer {\n"
3936 " size = 27; align = 1; signed = false;\n"
3937 " map = clock.%s.value;\n"
3938 "} := uint27_clock_monotonic_t;\n"
3939 "\n"
3940 "typealias integer {\n"
3941 " size = 32; align = %u; signed = false;\n"
3942 " map = clock.%s.value;\n"
3943 "} := uint32_clock_monotonic_t;\n"
3944 "\n"
3945 "typealias integer {\n"
3946 " size = 64; align = %u; signed = false;\n"
3947 " map = clock.%s.value;\n"
3948 "} := uint64_clock_monotonic_t;\n\n",
3949 trace_clock_name(),
3950 lttng_alignof(uint32_t) * CHAR_BIT,
3951 trace_clock_name(),
3952 lttng_alignof(uint64_t) * CHAR_BIT,
3953 trace_clock_name()
3954 );
3955 if (ret)
3956 goto end;
3957
3958 ret = _lttng_stream_packet_context_declare(session);
3959 if (ret)
3960 goto end;
3961
3962 ret = _lttng_event_header_declare(session);
3963 if (ret)
3964 goto end;
3965
3966 skip_session:
3967 list_for_each_entry(chan, &session->chan, list) {
3968 ret = _lttng_channel_metadata_statedump(session, chan);
3969 if (ret)
3970 goto end;
3971 }
3972
3973 list_for_each_entry(event, &session->events, list) {
3974 ret = _lttng_event_metadata_statedump(session, event->chan, event);
3975 if (ret)
3976 goto end;
3977 }
3978 session->metadata_dumped = 1;
3979 end:
3980 lttng_metadata_end(session);
3981 return ret;
3982 }
3983
3984 /**
3985 * lttng_transport_register - LTT transport registration
3986 * @transport: transport structure
3987 *
3988 * Registers a transport which can be used as output to extract the data out of
3989 * LTTng. The module calling this registration function must ensure that no
3990 * trap-inducing code will be executed by the transport functions. E.g.
3991 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
3992 * is made visible to the transport function. This registration acts as a
3993 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
3994 * after its registration must it synchronize the TLBs.
3995 */
3996 void lttng_transport_register(struct lttng_transport *transport)
3997 {
3998 /*
3999 * Make sure no page fault can be triggered by the module about to be
4000 * registered. We deal with this here so we don't have to call
4001 * vmalloc_sync_mappings() in each module's init.
4002 */
4003 wrapper_vmalloc_sync_mappings();
4004
4005 mutex_lock(&sessions_mutex);
4006 list_add_tail(&transport->node, &lttng_transport_list);
4007 mutex_unlock(&sessions_mutex);
4008 }
4009 EXPORT_SYMBOL_GPL(lttng_transport_register);
4010
4011 /**
4012 * lttng_transport_unregister - LTT transport unregistration
4013 * @transport: transport structure
4014 */
4015 void lttng_transport_unregister(struct lttng_transport *transport)
4016 {
4017 mutex_lock(&sessions_mutex);
4018 list_del(&transport->node);
4019 mutex_unlock(&sessions_mutex);
4020 }
4021 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4022
4023 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4024 {
4025 /*
4026 * Make sure no page fault can be triggered by the module about to be
4027 * registered. We deal with this here so we don't have to call
4028 * vmalloc_sync_mappings() in each module's init.
4029 */
4030 wrapper_vmalloc_sync_mappings();
4031
4032 mutex_lock(&sessions_mutex);
4033 list_add_tail(&transport->node, &lttng_counter_transport_list);
4034 mutex_unlock(&sessions_mutex);
4035 }
4036 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4037
4038 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4039 {
4040 mutex_lock(&sessions_mutex);
4041 list_del(&transport->node);
4042 mutex_unlock(&sessions_mutex);
4043 }
4044 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4045
4046 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4047
4048 enum cpuhp_state lttng_hp_prepare;
4049 enum cpuhp_state lttng_hp_online;
4050
4051 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4052 {
4053 struct lttng_cpuhp_node *lttng_node;
4054
4055 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4056 switch (lttng_node->component) {
4057 case LTTNG_RING_BUFFER_FRONTEND:
4058 return 0;
4059 case LTTNG_RING_BUFFER_BACKEND:
4060 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4061 case LTTNG_RING_BUFFER_ITER:
4062 return 0;
4063 case LTTNG_CONTEXT_PERF_COUNTERS:
4064 return 0;
4065 default:
4066 return -EINVAL;
4067 }
4068 }
4069
4070 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4071 {
4072 struct lttng_cpuhp_node *lttng_node;
4073
4074 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4075 switch (lttng_node->component) {
4076 case LTTNG_RING_BUFFER_FRONTEND:
4077 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4078 case LTTNG_RING_BUFFER_BACKEND:
4079 return 0;
4080 case LTTNG_RING_BUFFER_ITER:
4081 return 0;
4082 case LTTNG_CONTEXT_PERF_COUNTERS:
4083 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4084 default:
4085 return -EINVAL;
4086 }
4087 }
4088
4089 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4090 {
4091 struct lttng_cpuhp_node *lttng_node;
4092
4093 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4094 switch (lttng_node->component) {
4095 case LTTNG_RING_BUFFER_FRONTEND:
4096 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4097 case LTTNG_RING_BUFFER_BACKEND:
4098 return 0;
4099 case LTTNG_RING_BUFFER_ITER:
4100 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4101 case LTTNG_CONTEXT_PERF_COUNTERS:
4102 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4103 default:
4104 return -EINVAL;
4105 }
4106 }
4107
4108 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4109 {
4110 struct lttng_cpuhp_node *lttng_node;
4111
4112 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4113 switch (lttng_node->component) {
4114 case LTTNG_RING_BUFFER_FRONTEND:
4115 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4116 case LTTNG_RING_BUFFER_BACKEND:
4117 return 0;
4118 case LTTNG_RING_BUFFER_ITER:
4119 return 0;
4120 case LTTNG_CONTEXT_PERF_COUNTERS:
4121 return 0;
4122 default:
4123 return -EINVAL;
4124 }
4125 }
4126
4127 static int __init lttng_init_cpu_hotplug(void)
4128 {
4129 int ret;
4130
4131 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4132 lttng_hotplug_prepare,
4133 lttng_hotplug_dead);
4134 if (ret < 0) {
4135 return ret;
4136 }
4137 lttng_hp_prepare = ret;
4138 lttng_rb_set_hp_prepare(ret);
4139
4140 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4141 lttng_hotplug_online,
4142 lttng_hotplug_offline);
4143 if (ret < 0) {
4144 cpuhp_remove_multi_state(lttng_hp_prepare);
4145 lttng_hp_prepare = 0;
4146 return ret;
4147 }
4148 lttng_hp_online = ret;
4149 lttng_rb_set_hp_online(ret);
4150
4151 return 0;
4152 }
4153
4154 static void __exit lttng_exit_cpu_hotplug(void)
4155 {
4156 lttng_rb_set_hp_online(0);
4157 cpuhp_remove_multi_state(lttng_hp_online);
4158 lttng_rb_set_hp_prepare(0);
4159 cpuhp_remove_multi_state(lttng_hp_prepare);
4160 }
4161
4162 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4163 static int lttng_init_cpu_hotplug(void)
4164 {
4165 return 0;
4166 }
4167 static void lttng_exit_cpu_hotplug(void)
4168 {
4169 }
4170 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4171
4172
4173 static int __init lttng_events_init(void)
4174 {
4175 int ret;
4176
4177 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4178 if (ret)
4179 return ret;
4180 ret = wrapper_get_pfnblock_flags_mask_init();
4181 if (ret)
4182 return ret;
4183 ret = wrapper_get_pageblock_flags_mask_init();
4184 if (ret)
4185 return ret;
4186 ret = lttng_probes_init();
4187 if (ret)
4188 return ret;
4189 ret = lttng_context_init();
4190 if (ret)
4191 return ret;
4192 ret = lttng_tracepoint_init();
4193 if (ret)
4194 goto error_tp;
4195 event_cache = KMEM_CACHE(lttng_event, 0);
4196 if (!event_cache) {
4197 ret = -ENOMEM;
4198 goto error_kmem_event;
4199 }
4200 event_notifier_cache = KMEM_CACHE(lttng_event_notifier, 0);
4201 if (!event_notifier_cache) {
4202 ret = -ENOMEM;
4203 goto error_kmem_event_notifier;
4204 }
4205 ret = lttng_abi_init();
4206 if (ret)
4207 goto error_abi;
4208 ret = lttng_logger_init();
4209 if (ret)
4210 goto error_logger;
4211 ret = lttng_init_cpu_hotplug();
4212 if (ret)
4213 goto error_hotplug;
4214 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4215 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4216 __stringify(LTTNG_MODULES_MINOR_VERSION),
4217 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4218 LTTNG_MODULES_EXTRAVERSION,
4219 LTTNG_VERSION_NAME,
4220 #ifdef LTTNG_EXTRA_VERSION_GIT
4221 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4222 #else
4223 "",
4224 #endif
4225 #ifdef LTTNG_EXTRA_VERSION_NAME
4226 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4227 #else
4228 "");
4229 #endif
4230 return 0;
4231
4232 error_hotplug:
4233 lttng_logger_exit();
4234 error_logger:
4235 lttng_abi_exit();
4236 error_abi:
4237 kmem_cache_destroy(event_notifier_cache);
4238 error_kmem_event_notifier:
4239 kmem_cache_destroy(event_cache);
4240 error_kmem_event:
4241 lttng_tracepoint_exit();
4242 error_tp:
4243 lttng_context_exit();
4244 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4245 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4246 __stringify(LTTNG_MODULES_MINOR_VERSION),
4247 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4248 LTTNG_MODULES_EXTRAVERSION,
4249 LTTNG_VERSION_NAME,
4250 #ifdef LTTNG_EXTRA_VERSION_GIT
4251 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4252 #else
4253 "",
4254 #endif
4255 #ifdef LTTNG_EXTRA_VERSION_NAME
4256 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4257 #else
4258 "");
4259 #endif
4260 return ret;
4261 }
4262
4263 module_init(lttng_events_init);
4264
4265 static void __exit lttng_events_exit(void)
4266 {
4267 struct lttng_session *session, *tmpsession;
4268
4269 lttng_exit_cpu_hotplug();
4270 lttng_logger_exit();
4271 lttng_abi_exit();
4272 list_for_each_entry_safe(session, tmpsession, &sessions, list)
4273 lttng_session_destroy(session);
4274 kmem_cache_destroy(event_cache);
4275 kmem_cache_destroy(event_notifier_cache);
4276 lttng_tracepoint_exit();
4277 lttng_context_exit();
4278 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4279 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4280 __stringify(LTTNG_MODULES_MINOR_VERSION),
4281 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4282 LTTNG_MODULES_EXTRAVERSION,
4283 LTTNG_VERSION_NAME,
4284 #ifdef LTTNG_EXTRA_VERSION_GIT
4285 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4286 #else
4287 "",
4288 #endif
4289 #ifdef LTTNG_EXTRA_VERSION_NAME
4290 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4291 #else
4292 "");
4293 #endif
4294 }
4295
4296 module_exit(lttng_events_exit);
4297
4298 #include <generated/patches.h>
4299 #ifdef LTTNG_EXTRA_VERSION_GIT
4300 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4301 #endif
4302 #ifdef LTTNG_EXTRA_VERSION_NAME
4303 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4304 #endif
4305 MODULE_LICENSE("GPL and additional rights");
4306 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4307 MODULE_DESCRIPTION("LTTng tracer");
4308 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4309 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4310 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4311 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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