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Fix: racy notifier captures update vs traversal
[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 INIT_LIST_HEAD(&event_return->filter_bytecode_runtime_head);
953 INIT_LIST_HEAD(&event_return->enablers_ref_head);
954 /*
955 * Populate lttng_event structure before kretprobe registration.
956 */
957 smp_wmb();
958 ret = lttng_kretprobes_register(event_name,
959 event_param->u.kretprobe.symbol_name,
960 event_param->u.kretprobe.offset,
961 event_param->u.kretprobe.addr,
962 event, event_return);
963 if (ret) {
964 kmem_cache_free(event_cache, event_return);
965 ret = -EINVAL;
966 goto register_error;
967 }
968 /* Take 2 refs on the module: one per event. */
969 ret = try_module_get(event->desc->owner);
970 WARN_ON_ONCE(!ret);
971 ret = try_module_get(event->desc->owner);
972 WARN_ON_ONCE(!ret);
973 ret = _lttng_event_metadata_statedump(chan->session, chan,
974 event_return);
975 WARN_ON_ONCE(ret > 0);
976 if (ret) {
977 kmem_cache_free(event_cache, event_return);
978 module_put(event->desc->owner);
979 module_put(event->desc->owner);
980 goto statedump_error;
981 }
982 list_add(&event_return->list, &chan->session->events);
983 break;
984 }
985 case LTTNG_KERNEL_NOOP:
986 case LTTNG_KERNEL_SYSCALL:
987 /*
988 * Needs to be explicitly enabled after creation, since
989 * we may want to apply filters.
990 */
991 event->enabled = 0;
992 event->registered = 0;
993 event->desc = event_desc;
994 switch (event_param->u.syscall.entryexit) {
995 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
996 ret = -EINVAL;
997 goto register_error;
998 case LTTNG_KERNEL_SYSCALL_ENTRY:
999 event->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1000 break;
1001 case LTTNG_KERNEL_SYSCALL_EXIT:
1002 event->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1003 break;
1004 }
1005 switch (event_param->u.syscall.abi) {
1006 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
1007 ret = -EINVAL;
1008 goto register_error;
1009 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
1010 event->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1011 break;
1012 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
1013 event->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1014 break;
1015 }
1016 if (!event->desc) {
1017 ret = -EINVAL;
1018 goto register_error;
1019 }
1020 break;
1021 case LTTNG_KERNEL_UPROBE:
1022 /*
1023 * Needs to be explicitly enabled after creation, since
1024 * we may want to apply filters.
1025 */
1026 event->enabled = 0;
1027 event->registered = 1;
1028
1029 /*
1030 * Populate lttng_event structure before event
1031 * registration.
1032 */
1033 smp_wmb();
1034
1035 ret = lttng_uprobes_register_event(event_param->name,
1036 event_param->u.uprobe.fd,
1037 event);
1038 if (ret)
1039 goto register_error;
1040 ret = try_module_get(event->desc->owner);
1041 WARN_ON_ONCE(!ret);
1042 break;
1043 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1044 default:
1045 WARN_ON_ONCE(1);
1046 ret = -EINVAL;
1047 goto register_error;
1048 }
1049 ret = _lttng_event_metadata_statedump(chan->session, chan, event);
1050 WARN_ON_ONCE(ret > 0);
1051 if (ret) {
1052 goto statedump_error;
1053 }
1054 hlist_add_head(&event->hlist, head);
1055 list_add(&event->list, &chan->session->events);
1056 return event;
1057
1058 statedump_error:
1059 /* If a statedump error occurs, events will not be readable. */
1060 register_error:
1061 kmem_cache_free(event_cache, event);
1062 cache_error:
1063 exist:
1064 type_error:
1065 full:
1066 return ERR_PTR(ret);
1067 }
1068
1069 struct lttng_event_notifier *_lttng_event_notifier_create(
1070 const struct lttng_event_desc *event_desc,
1071 uint64_t token, uint64_t error_counter_index,
1072 struct lttng_event_notifier_group *event_notifier_group,
1073 struct lttng_kernel_event_notifier *event_notifier_param,
1074 void *filter, enum lttng_kernel_instrumentation itype)
1075 {
1076 struct lttng_event_notifier *event_notifier;
1077 struct lttng_counter *error_counter;
1078 const char *event_name;
1079 struct hlist_head *head;
1080 int ret;
1081
1082 switch (itype) {
1083 case LTTNG_KERNEL_TRACEPOINT:
1084 event_name = event_desc->name;
1085 break;
1086 case LTTNG_KERNEL_KPROBE:
1087 case LTTNG_KERNEL_UPROBE:
1088 case LTTNG_KERNEL_SYSCALL:
1089 event_name = event_notifier_param->event.name;
1090 break;
1091 case LTTNG_KERNEL_KRETPROBE:
1092 case LTTNG_KERNEL_FUNCTION:
1093 case LTTNG_KERNEL_NOOP:
1094 default:
1095 WARN_ON_ONCE(1);
1096 ret = -EINVAL;
1097 goto type_error;
1098 }
1099
1100 head = utils_borrow_hash_table_bucket(event_notifier_group->event_notifiers_ht.table,
1101 LTTNG_EVENT_NOTIFIER_HT_SIZE, event_name);
1102 lttng_hlist_for_each_entry(event_notifier, head, hlist) {
1103 WARN_ON_ONCE(!event_notifier->desc);
1104 if (!strncmp(event_notifier->desc->name, event_name,
1105 LTTNG_KERNEL_SYM_NAME_LEN - 1)
1106 && event_notifier_group == event_notifier->group
1107 && token == event_notifier->user_token) {
1108 ret = -EEXIST;
1109 goto exist;
1110 }
1111 }
1112
1113 event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
1114 if (!event_notifier) {
1115 ret = -ENOMEM;
1116 goto cache_error;
1117 }
1118
1119 event_notifier->group = event_notifier_group;
1120 event_notifier->user_token = token;
1121 event_notifier->error_counter_index = error_counter_index;
1122 event_notifier->num_captures = 0;
1123 event_notifier->filter = filter;
1124 event_notifier->instrumentation = itype;
1125 event_notifier->evtype = LTTNG_TYPE_EVENT;
1126 event_notifier->send_notification = lttng_event_notifier_notification_send;
1127 INIT_LIST_HEAD(&event_notifier->filter_bytecode_runtime_head);
1128 INIT_LIST_HEAD(&event_notifier->capture_bytecode_runtime_head);
1129 INIT_LIST_HEAD(&event_notifier->enablers_ref_head);
1130
1131 switch (itype) {
1132 case LTTNG_KERNEL_TRACEPOINT:
1133 /* Event will be enabled by enabler sync. */
1134 event_notifier->enabled = 0;
1135 event_notifier->registered = 0;
1136 event_notifier->desc = lttng_event_desc_get(event_name);
1137 if (!event_notifier->desc) {
1138 ret = -ENOENT;
1139 goto register_error;
1140 }
1141 /* Populate lttng_event_notifier structure before event registration. */
1142 smp_wmb();
1143 break;
1144 case LTTNG_KERNEL_KPROBE:
1145 /*
1146 * Needs to be explicitly enabled after creation, since
1147 * we may want to apply filters.
1148 */
1149 event_notifier->enabled = 0;
1150 event_notifier->registered = 1;
1151 /*
1152 * Populate lttng_event_notifier structure before event
1153 * registration.
1154 */
1155 smp_wmb();
1156 ret = lttng_kprobes_register_event_notifier(
1157 event_notifier_param->event.u.kprobe.symbol_name,
1158 event_notifier_param->event.u.kprobe.offset,
1159 event_notifier_param->event.u.kprobe.addr,
1160 event_notifier);
1161 if (ret) {
1162 ret = -EINVAL;
1163 goto register_error;
1164 }
1165 ret = try_module_get(event_notifier->desc->owner);
1166 WARN_ON_ONCE(!ret);
1167 break;
1168 case LTTNG_KERNEL_NOOP:
1169 case LTTNG_KERNEL_SYSCALL:
1170 /*
1171 * Needs to be explicitly enabled after creation, since
1172 * we may want to apply filters.
1173 */
1174 event_notifier->enabled = 0;
1175 event_notifier->registered = 0;
1176 event_notifier->desc = event_desc;
1177 switch (event_notifier_param->event.u.syscall.entryexit) {
1178 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
1179 ret = -EINVAL;
1180 goto register_error;
1181 case LTTNG_KERNEL_SYSCALL_ENTRY:
1182 event_notifier->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1183 break;
1184 case LTTNG_KERNEL_SYSCALL_EXIT:
1185 event_notifier->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1186 break;
1187 }
1188 switch (event_notifier_param->event.u.syscall.abi) {
1189 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
1190 ret = -EINVAL;
1191 goto register_error;
1192 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
1193 event_notifier->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1194 break;
1195 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
1196 event_notifier->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1197 break;
1198 }
1199
1200 if (!event_notifier->desc) {
1201 ret = -EINVAL;
1202 goto register_error;
1203 }
1204 break;
1205 case LTTNG_KERNEL_UPROBE:
1206 /*
1207 * Needs to be explicitly enabled after creation, since
1208 * we may want to apply filters.
1209 */
1210 event_notifier->enabled = 0;
1211 event_notifier->registered = 1;
1212
1213 /*
1214 * Populate lttng_event_notifier structure before
1215 * event_notifier registration.
1216 */
1217 smp_wmb();
1218
1219 ret = lttng_uprobes_register_event_notifier(
1220 event_notifier_param->event.name,
1221 event_notifier_param->event.u.uprobe.fd,
1222 event_notifier);
1223 if (ret)
1224 goto register_error;
1225 ret = try_module_get(event_notifier->desc->owner);
1226 WARN_ON_ONCE(!ret);
1227 break;
1228 case LTTNG_KERNEL_KRETPROBE:
1229 case LTTNG_KERNEL_FUNCTION:
1230 default:
1231 WARN_ON_ONCE(1);
1232 ret = -EINVAL;
1233 goto register_error;
1234 }
1235
1236 list_add(&event_notifier->list, &event_notifier_group->event_notifiers_head);
1237 hlist_add_head(&event_notifier->hlist, head);
1238
1239 /*
1240 * Clear the error counter bucket. The sessiond keeps track of which
1241 * bucket is currently in use. We trust it. The session lock
1242 * synchronizes against concurrent creation of the error
1243 * counter.
1244 */
1245 error_counter = event_notifier_group->error_counter;
1246 if (error_counter) {
1247 size_t dimension_index[1];
1248
1249 /*
1250 * Check that the index is within the boundary of the counter.
1251 */
1252 if (event_notifier->error_counter_index >= event_notifier_group->error_counter_len) {
1253 printk(KERN_INFO "LTTng: event_notifier: Error counter index out-of-bound: counter-len=%zu, index=%llu\n",
1254 event_notifier_group->error_counter_len, event_notifier->error_counter_index);
1255 ret = -EINVAL;
1256 goto register_error;
1257 }
1258
1259 dimension_index[0] = event_notifier->error_counter_index;
1260 ret = error_counter->ops->counter_clear(error_counter->counter, dimension_index);
1261 if (ret) {
1262 printk(KERN_INFO "LTTng: event_notifier: Unable to clear error counter bucket %llu\n",
1263 event_notifier->error_counter_index);
1264 goto register_error;
1265 }
1266 }
1267
1268 return event_notifier;
1269
1270 register_error:
1271 kmem_cache_free(event_notifier_cache, event_notifier);
1272 cache_error:
1273 exist:
1274 type_error:
1275 return ERR_PTR(ret);
1276 }
1277
1278 int lttng_kernel_counter_read(struct lttng_counter *counter,
1279 const size_t *dim_indexes, int32_t cpu,
1280 int64_t *val, bool *overflow, bool *underflow)
1281 {
1282 return counter->ops->counter_read(counter->counter, dim_indexes,
1283 cpu, val, overflow, underflow);
1284 }
1285
1286 int lttng_kernel_counter_aggregate(struct lttng_counter *counter,
1287 const size_t *dim_indexes, int64_t *val,
1288 bool *overflow, bool *underflow)
1289 {
1290 return counter->ops->counter_aggregate(counter->counter, dim_indexes,
1291 val, overflow, underflow);
1292 }
1293
1294 int lttng_kernel_counter_clear(struct lttng_counter *counter,
1295 const size_t *dim_indexes)
1296 {
1297 return counter->ops->counter_clear(counter->counter, dim_indexes);
1298 }
1299
1300 struct lttng_event *lttng_event_create(struct lttng_channel *chan,
1301 struct lttng_kernel_event *event_param,
1302 void *filter,
1303 const struct lttng_event_desc *event_desc,
1304 enum lttng_kernel_instrumentation itype)
1305 {
1306 struct lttng_event *event;
1307
1308 mutex_lock(&sessions_mutex);
1309 event = _lttng_event_create(chan, event_param, filter, event_desc,
1310 itype);
1311 mutex_unlock(&sessions_mutex);
1312 return event;
1313 }
1314
1315 struct lttng_event_notifier *lttng_event_notifier_create(
1316 const struct lttng_event_desc *event_desc,
1317 uint64_t id, uint64_t error_counter_index,
1318 struct lttng_event_notifier_group *event_notifier_group,
1319 struct lttng_kernel_event_notifier *event_notifier_param,
1320 void *filter, enum lttng_kernel_instrumentation itype)
1321 {
1322 struct lttng_event_notifier *event_notifier;
1323
1324 mutex_lock(&sessions_mutex);
1325 event_notifier = _lttng_event_notifier_create(event_desc, id,
1326 error_counter_index, event_notifier_group,
1327 event_notifier_param, filter, itype);
1328 mutex_unlock(&sessions_mutex);
1329 return event_notifier;
1330 }
1331
1332 /* Only used for tracepoints for now. */
1333 static
1334 void register_event(struct lttng_event *event)
1335 {
1336 const struct lttng_event_desc *desc;
1337 int ret = -EINVAL;
1338
1339 if (event->registered)
1340 return;
1341
1342 desc = event->desc;
1343 switch (event->instrumentation) {
1344 case LTTNG_KERNEL_TRACEPOINT:
1345 ret = lttng_wrapper_tracepoint_probe_register(desc->kname,
1346 desc->probe_callback,
1347 event);
1348 break;
1349 case LTTNG_KERNEL_SYSCALL:
1350 ret = lttng_syscall_filter_enable_event(event->chan, event);
1351 break;
1352 case LTTNG_KERNEL_KPROBE:
1353 case LTTNG_KERNEL_UPROBE:
1354 case LTTNG_KERNEL_KRETPROBE:
1355 case LTTNG_KERNEL_NOOP:
1356 ret = 0;
1357 break;
1358 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1359 default:
1360 WARN_ON_ONCE(1);
1361 }
1362 if (!ret)
1363 event->registered = 1;
1364 }
1365
1366 /*
1367 * Only used internally at session destruction.
1368 */
1369 int _lttng_event_unregister(struct lttng_event *event)
1370 {
1371 const struct lttng_event_desc *desc;
1372 int ret = -EINVAL;
1373
1374 if (!event->registered)
1375 return 0;
1376
1377 desc = event->desc;
1378 switch (event->instrumentation) {
1379 case LTTNG_KERNEL_TRACEPOINT:
1380 ret = lttng_wrapper_tracepoint_probe_unregister(event->desc->kname,
1381 event->desc->probe_callback,
1382 event);
1383 break;
1384 case LTTNG_KERNEL_KPROBE:
1385 lttng_kprobes_unregister_event(event);
1386 ret = 0;
1387 break;
1388 case LTTNG_KERNEL_KRETPROBE:
1389 lttng_kretprobes_unregister(event);
1390 ret = 0;
1391 break;
1392 case LTTNG_KERNEL_SYSCALL:
1393 ret = lttng_syscall_filter_disable_event(event->chan, event);
1394 break;
1395 case LTTNG_KERNEL_NOOP:
1396 ret = 0;
1397 break;
1398 case LTTNG_KERNEL_UPROBE:
1399 lttng_uprobes_unregister_event(event);
1400 ret = 0;
1401 break;
1402 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1403 default:
1404 WARN_ON_ONCE(1);
1405 }
1406 if (!ret)
1407 event->registered = 0;
1408 return ret;
1409 }
1410
1411 /* Only used for tracepoints for now. */
1412 static
1413 void register_event_notifier(struct lttng_event_notifier *event_notifier)
1414 {
1415 const struct lttng_event_desc *desc;
1416 int ret = -EINVAL;
1417
1418 if (event_notifier->registered)
1419 return;
1420
1421 desc = event_notifier->desc;
1422 switch (event_notifier->instrumentation) {
1423 case LTTNG_KERNEL_TRACEPOINT:
1424 ret = lttng_wrapper_tracepoint_probe_register(desc->kname,
1425 desc->event_notifier_callback,
1426 event_notifier);
1427 break;
1428 case LTTNG_KERNEL_SYSCALL:
1429 ret = lttng_syscall_filter_enable_event_notifier(event_notifier);
1430 break;
1431 case LTTNG_KERNEL_KPROBE:
1432 case LTTNG_KERNEL_UPROBE:
1433 ret = 0;
1434 break;
1435 case LTTNG_KERNEL_KRETPROBE:
1436 case LTTNG_KERNEL_FUNCTION:
1437 case LTTNG_KERNEL_NOOP:
1438 default:
1439 WARN_ON_ONCE(1);
1440 }
1441 if (!ret)
1442 event_notifier->registered = 1;
1443 }
1444
1445 static
1446 int _lttng_event_notifier_unregister(
1447 struct lttng_event_notifier *event_notifier)
1448 {
1449 const struct lttng_event_desc *desc;
1450 int ret = -EINVAL;
1451
1452 if (!event_notifier->registered)
1453 return 0;
1454
1455 desc = event_notifier->desc;
1456 switch (event_notifier->instrumentation) {
1457 case LTTNG_KERNEL_TRACEPOINT:
1458 ret = lttng_wrapper_tracepoint_probe_unregister(event_notifier->desc->kname,
1459 event_notifier->desc->event_notifier_callback,
1460 event_notifier);
1461 break;
1462 case LTTNG_KERNEL_KPROBE:
1463 lttng_kprobes_unregister_event_notifier(event_notifier);
1464 ret = 0;
1465 break;
1466 case LTTNG_KERNEL_UPROBE:
1467 lttng_uprobes_unregister_event_notifier(event_notifier);
1468 ret = 0;
1469 break;
1470 case LTTNG_KERNEL_SYSCALL:
1471 ret = lttng_syscall_filter_disable_event_notifier(event_notifier);
1472 break;
1473 case LTTNG_KERNEL_KRETPROBE:
1474 case LTTNG_KERNEL_FUNCTION:
1475 case LTTNG_KERNEL_NOOP:
1476 default:
1477 WARN_ON_ONCE(1);
1478 }
1479 if (!ret)
1480 event_notifier->registered = 0;
1481 return ret;
1482 }
1483
1484 /*
1485 * Only used internally at session destruction.
1486 */
1487 static
1488 void _lttng_event_destroy(struct lttng_event *event)
1489 {
1490 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1491
1492 switch (event->instrumentation) {
1493 case LTTNG_KERNEL_TRACEPOINT:
1494 lttng_event_desc_put(event->desc);
1495 break;
1496 case LTTNG_KERNEL_KPROBE:
1497 module_put(event->desc->owner);
1498 lttng_kprobes_destroy_event_private(event);
1499 break;
1500 case LTTNG_KERNEL_KRETPROBE:
1501 module_put(event->desc->owner);
1502 lttng_kretprobes_destroy_private(event);
1503 break;
1504 case LTTNG_KERNEL_NOOP:
1505 case LTTNG_KERNEL_SYSCALL:
1506 break;
1507 case LTTNG_KERNEL_UPROBE:
1508 module_put(event->desc->owner);
1509 lttng_uprobes_destroy_event_private(event);
1510 break;
1511 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1512 default:
1513 WARN_ON_ONCE(1);
1514 }
1515 list_del(&event->list);
1516 lttng_destroy_context(event->ctx);
1517 lttng_free_event_filter_runtime(event);
1518 /* Free event enabler refs */
1519 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1520 &event->enablers_ref_head, node)
1521 kfree(enabler_ref);
1522 kmem_cache_free(event_cache, event);
1523 }
1524
1525 /*
1526 * Only used internally at session destruction.
1527 */
1528 static
1529 void _lttng_event_notifier_destroy(struct lttng_event_notifier *event_notifier)
1530 {
1531 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1532
1533 switch (event_notifier->instrumentation) {
1534 case LTTNG_KERNEL_TRACEPOINT:
1535 lttng_event_desc_put(event_notifier->desc);
1536 break;
1537 case LTTNG_KERNEL_KPROBE:
1538 module_put(event_notifier->desc->owner);
1539 lttng_kprobes_destroy_event_notifier_private(event_notifier);
1540 break;
1541 case LTTNG_KERNEL_NOOP:
1542 case LTTNG_KERNEL_SYSCALL:
1543 break;
1544 case LTTNG_KERNEL_UPROBE:
1545 module_put(event_notifier->desc->owner);
1546 lttng_uprobes_destroy_event_notifier_private(event_notifier);
1547 break;
1548 case LTTNG_KERNEL_KRETPROBE:
1549 case LTTNG_KERNEL_FUNCTION:
1550 default:
1551 WARN_ON_ONCE(1);
1552 }
1553 list_del(&event_notifier->list);
1554 lttng_free_event_notifier_filter_runtime(event_notifier);
1555 /* Free event enabler refs */
1556 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1557 &event_notifier->enablers_ref_head, node)
1558 kfree(enabler_ref);
1559 kmem_cache_free(event_notifier_cache, event_notifier);
1560 }
1561
1562 struct lttng_id_tracker *get_tracker(struct lttng_session *session,
1563 enum tracker_type tracker_type)
1564 {
1565 switch (tracker_type) {
1566 case TRACKER_PID:
1567 return &session->pid_tracker;
1568 case TRACKER_VPID:
1569 return &session->vpid_tracker;
1570 case TRACKER_UID:
1571 return &session->uid_tracker;
1572 case TRACKER_VUID:
1573 return &session->vuid_tracker;
1574 case TRACKER_GID:
1575 return &session->gid_tracker;
1576 case TRACKER_VGID:
1577 return &session->vgid_tracker;
1578 default:
1579 WARN_ON_ONCE(1);
1580 return NULL;
1581 }
1582 }
1583
1584 int lttng_session_track_id(struct lttng_session *session,
1585 enum tracker_type tracker_type, int id)
1586 {
1587 struct lttng_id_tracker *tracker;
1588 int ret;
1589
1590 tracker = get_tracker(session, tracker_type);
1591 if (!tracker)
1592 return -EINVAL;
1593 if (id < -1)
1594 return -EINVAL;
1595 mutex_lock(&sessions_mutex);
1596 if (id == -1) {
1597 /* track all ids: destroy tracker. */
1598 lttng_id_tracker_destroy(tracker, true);
1599 ret = 0;
1600 } else {
1601 ret = lttng_id_tracker_add(tracker, id);
1602 }
1603 mutex_unlock(&sessions_mutex);
1604 return ret;
1605 }
1606
1607 int lttng_session_untrack_id(struct lttng_session *session,
1608 enum tracker_type tracker_type, int id)
1609 {
1610 struct lttng_id_tracker *tracker;
1611 int ret;
1612
1613 tracker = get_tracker(session, tracker_type);
1614 if (!tracker)
1615 return -EINVAL;
1616 if (id < -1)
1617 return -EINVAL;
1618 mutex_lock(&sessions_mutex);
1619 if (id == -1) {
1620 /* untrack all ids: replace by empty tracker. */
1621 ret = lttng_id_tracker_empty_set(tracker);
1622 } else {
1623 ret = lttng_id_tracker_del(tracker, id);
1624 }
1625 mutex_unlock(&sessions_mutex);
1626 return ret;
1627 }
1628
1629 static
1630 void *id_list_start(struct seq_file *m, loff_t *pos)
1631 {
1632 struct lttng_id_tracker *id_tracker = m->private;
1633 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1634 struct lttng_id_hash_node *e;
1635 int iter = 0, i;
1636
1637 mutex_lock(&sessions_mutex);
1638 if (id_tracker_p) {
1639 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1640 struct hlist_head *head = &id_tracker_p->id_hash[i];
1641
1642 lttng_hlist_for_each_entry(e, head, hlist) {
1643 if (iter++ >= *pos)
1644 return e;
1645 }
1646 }
1647 } else {
1648 /* ID tracker disabled. */
1649 if (iter >= *pos && iter == 0) {
1650 return id_tracker_p; /* empty tracker */
1651 }
1652 iter++;
1653 }
1654 /* End of list */
1655 return NULL;
1656 }
1657
1658 /* Called with sessions_mutex held. */
1659 static
1660 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1661 {
1662 struct lttng_id_tracker *id_tracker = m->private;
1663 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1664 struct lttng_id_hash_node *e;
1665 int iter = 0, i;
1666
1667 (*ppos)++;
1668 if (id_tracker_p) {
1669 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1670 struct hlist_head *head = &id_tracker_p->id_hash[i];
1671
1672 lttng_hlist_for_each_entry(e, head, hlist) {
1673 if (iter++ >= *ppos)
1674 return e;
1675 }
1676 }
1677 } else {
1678 /* ID tracker disabled. */
1679 if (iter >= *ppos && iter == 0)
1680 return p; /* empty tracker */
1681 iter++;
1682 }
1683
1684 /* End of list */
1685 return NULL;
1686 }
1687
1688 static
1689 void id_list_stop(struct seq_file *m, void *p)
1690 {
1691 mutex_unlock(&sessions_mutex);
1692 }
1693
1694 static
1695 int id_list_show(struct seq_file *m, void *p)
1696 {
1697 struct lttng_id_tracker *id_tracker = m->private;
1698 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1699 int id;
1700
1701 if (p == id_tracker_p) {
1702 /* Tracker disabled. */
1703 id = -1;
1704 } else {
1705 const struct lttng_id_hash_node *e = p;
1706
1707 id = lttng_id_tracker_get_node_id(e);
1708 }
1709 switch (id_tracker->tracker_type) {
1710 case TRACKER_PID:
1711 seq_printf(m, "process { pid = %d; };\n", id);
1712 break;
1713 case TRACKER_VPID:
1714 seq_printf(m, "process { vpid = %d; };\n", id);
1715 break;
1716 case TRACKER_UID:
1717 seq_printf(m, "user { uid = %d; };\n", id);
1718 break;
1719 case TRACKER_VUID:
1720 seq_printf(m, "user { vuid = %d; };\n", id);
1721 break;
1722 case TRACKER_GID:
1723 seq_printf(m, "group { gid = %d; };\n", id);
1724 break;
1725 case TRACKER_VGID:
1726 seq_printf(m, "group { vgid = %d; };\n", id);
1727 break;
1728 default:
1729 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1730 }
1731 return 0;
1732 }
1733
1734 static
1735 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1736 .start = id_list_start,
1737 .next = id_list_next,
1738 .stop = id_list_stop,
1739 .show = id_list_show,
1740 };
1741
1742 static
1743 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1744 {
1745 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1746 }
1747
1748 static
1749 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1750 {
1751 struct seq_file *m = file->private_data;
1752 struct lttng_id_tracker *id_tracker = m->private;
1753 int ret;
1754
1755 WARN_ON_ONCE(!id_tracker);
1756 ret = seq_release(inode, file);
1757 if (!ret)
1758 fput(id_tracker->session->file);
1759 return ret;
1760 }
1761
1762 const struct file_operations lttng_tracker_ids_list_fops = {
1763 .owner = THIS_MODULE,
1764 .open = lttng_tracker_ids_list_open,
1765 .read = seq_read,
1766 .llseek = seq_lseek,
1767 .release = lttng_tracker_ids_list_release,
1768 };
1769
1770 int lttng_session_list_tracker_ids(struct lttng_session *session,
1771 enum tracker_type tracker_type)
1772 {
1773 struct file *tracker_ids_list_file;
1774 struct seq_file *m;
1775 int file_fd, ret;
1776
1777 file_fd = lttng_get_unused_fd();
1778 if (file_fd < 0) {
1779 ret = file_fd;
1780 goto fd_error;
1781 }
1782
1783 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1784 &lttng_tracker_ids_list_fops,
1785 NULL, O_RDWR);
1786 if (IS_ERR(tracker_ids_list_file)) {
1787 ret = PTR_ERR(tracker_ids_list_file);
1788 goto file_error;
1789 }
1790 if (!atomic_long_add_unless(&session->file->f_count, 1, LONG_MAX)) {
1791 ret = -EOVERFLOW;
1792 goto refcount_error;
1793 }
1794 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1795 if (ret < 0)
1796 goto open_error;
1797 m = tracker_ids_list_file->private_data;
1798
1799 m->private = get_tracker(session, tracker_type);
1800 BUG_ON(!m->private);
1801 fd_install(file_fd, tracker_ids_list_file);
1802
1803 return file_fd;
1804
1805 open_error:
1806 atomic_long_dec(&session->file->f_count);
1807 refcount_error:
1808 fput(tracker_ids_list_file);
1809 file_error:
1810 put_unused_fd(file_fd);
1811 fd_error:
1812 return ret;
1813 }
1814
1815 /*
1816 * Enabler management.
1817 */
1818 static
1819 int lttng_match_enabler_star_glob(const char *desc_name,
1820 const char *pattern)
1821 {
1822 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1823 desc_name, LTTNG_SIZE_MAX))
1824 return 0;
1825 return 1;
1826 }
1827
1828 static
1829 int lttng_match_enabler_name(const char *desc_name,
1830 const char *name)
1831 {
1832 if (strcmp(desc_name, name))
1833 return 0;
1834 return 1;
1835 }
1836
1837 int lttng_desc_match_enabler(const struct lttng_event_desc *desc,
1838 struct lttng_enabler *enabler)
1839 {
1840 const char *desc_name, *enabler_name;
1841 bool compat = false, entry = false;
1842
1843 enabler_name = enabler->event_param.name;
1844 switch (enabler->event_param.instrumentation) {
1845 case LTTNG_KERNEL_TRACEPOINT:
1846 desc_name = desc->name;
1847 switch (enabler->format_type) {
1848 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1849 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1850 case LTTNG_ENABLER_FORMAT_NAME:
1851 return lttng_match_enabler_name(desc_name, enabler_name);
1852 default:
1853 return -EINVAL;
1854 }
1855 break;
1856 case LTTNG_KERNEL_SYSCALL:
1857 desc_name = desc->name;
1858 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
1859 desc_name += strlen("compat_");
1860 compat = true;
1861 }
1862 if (!strncmp(desc_name, "syscall_exit_",
1863 strlen("syscall_exit_"))) {
1864 desc_name += strlen("syscall_exit_");
1865 } else if (!strncmp(desc_name, "syscall_entry_",
1866 strlen("syscall_entry_"))) {
1867 desc_name += strlen("syscall_entry_");
1868 entry = true;
1869 } else {
1870 WARN_ON_ONCE(1);
1871 return -EINVAL;
1872 }
1873 switch (enabler->event_param.u.syscall.entryexit) {
1874 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
1875 break;
1876 case LTTNG_KERNEL_SYSCALL_ENTRY:
1877 if (!entry)
1878 return 0;
1879 break;
1880 case LTTNG_KERNEL_SYSCALL_EXIT:
1881 if (entry)
1882 return 0;
1883 break;
1884 default:
1885 return -EINVAL;
1886 }
1887 switch (enabler->event_param.u.syscall.abi) {
1888 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
1889 break;
1890 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
1891 if (compat)
1892 return 0;
1893 break;
1894 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
1895 if (!compat)
1896 return 0;
1897 break;
1898 default:
1899 return -EINVAL;
1900 }
1901 switch (enabler->event_param.u.syscall.match) {
1902 case LTTNG_KERNEL_SYSCALL_MATCH_NAME:
1903 switch (enabler->format_type) {
1904 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1905 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1906 case LTTNG_ENABLER_FORMAT_NAME:
1907 return lttng_match_enabler_name(desc_name, enabler_name);
1908 default:
1909 return -EINVAL;
1910 }
1911 break;
1912 case LTTNG_KERNEL_SYSCALL_MATCH_NR:
1913 return -EINVAL; /* Not implemented. */
1914 default:
1915 return -EINVAL;
1916 }
1917 break;
1918 default:
1919 WARN_ON_ONCE(1);
1920 return -EINVAL;
1921 }
1922 }
1923
1924 static
1925 int lttng_event_enabler_match_event(struct lttng_event_enabler *event_enabler,
1926 struct lttng_event *event)
1927 {
1928 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(
1929 event_enabler);
1930
1931 if (base_enabler->event_param.instrumentation != event->instrumentation)
1932 return 0;
1933 if (lttng_desc_match_enabler(event->desc, base_enabler)
1934 && event->chan == event_enabler->chan)
1935 return 1;
1936 else
1937 return 0;
1938 }
1939
1940 static
1941 int lttng_event_notifier_enabler_match_event_notifier(struct lttng_event_notifier_enabler *event_notifier_enabler,
1942 struct lttng_event_notifier *event_notifier)
1943 {
1944 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(
1945 event_notifier_enabler);
1946
1947 if (base_enabler->event_param.instrumentation != event_notifier->instrumentation)
1948 return 0;
1949 if (lttng_desc_match_enabler(event_notifier->desc, base_enabler)
1950 && event_notifier->group == event_notifier_enabler->group
1951 && event_notifier->user_token == event_notifier_enabler->base.user_token)
1952 return 1;
1953 else
1954 return 0;
1955 }
1956
1957 static
1958 struct lttng_enabler_ref *lttng_enabler_ref(
1959 struct list_head *enablers_ref_list,
1960 struct lttng_enabler *enabler)
1961 {
1962 struct lttng_enabler_ref *enabler_ref;
1963
1964 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
1965 if (enabler_ref->ref == enabler)
1966 return enabler_ref;
1967 }
1968 return NULL;
1969 }
1970
1971 static
1972 void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler *event_enabler)
1973 {
1974 struct lttng_session *session = event_enabler->chan->session;
1975 struct lttng_probe_desc *probe_desc;
1976 const struct lttng_event_desc *desc;
1977 int i;
1978 struct list_head *probe_list;
1979
1980 probe_list = lttng_get_probe_list_head();
1981 /*
1982 * For each probe event, if we find that a probe event matches
1983 * our enabler, create an associated lttng_event if not
1984 * already present.
1985 */
1986 list_for_each_entry(probe_desc, probe_list, head) {
1987 for (i = 0; i < probe_desc->nr_events; i++) {
1988 int found = 0;
1989 struct hlist_head *head;
1990 struct lttng_event *event;
1991
1992 desc = probe_desc->event_desc[i];
1993 if (!lttng_desc_match_enabler(desc,
1994 lttng_event_enabler_as_enabler(event_enabler)))
1995 continue;
1996
1997 /*
1998 * Check if already created.
1999 */
2000 head = utils_borrow_hash_table_bucket(
2001 session->events_ht.table, LTTNG_EVENT_HT_SIZE,
2002 desc->name);
2003 lttng_hlist_for_each_entry(event, head, hlist) {
2004 if (event->desc == desc
2005 && event->chan == event_enabler->chan)
2006 found = 1;
2007 }
2008 if (found)
2009 continue;
2010
2011 /*
2012 * We need to create an event for this
2013 * event probe.
2014 */
2015 event = _lttng_event_create(event_enabler->chan,
2016 NULL, NULL, desc,
2017 LTTNG_KERNEL_TRACEPOINT);
2018 if (!event) {
2019 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2020 probe_desc->event_desc[i]->name);
2021 }
2022 }
2023 }
2024 }
2025
2026 static
2027 void lttng_create_tracepoint_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2028 {
2029 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2030 struct lttng_probe_desc *probe_desc;
2031 const struct lttng_event_desc *desc;
2032 int i;
2033 struct list_head *probe_list;
2034
2035 probe_list = lttng_get_probe_list_head();
2036 /*
2037 * For each probe event, if we find that a probe event matches
2038 * our enabler, create an associated lttng_event_notifier if not
2039 * already present.
2040 */
2041 list_for_each_entry(probe_desc, probe_list, head) {
2042 for (i = 0; i < probe_desc->nr_events; i++) {
2043 int found = 0;
2044 struct hlist_head *head;
2045 struct lttng_event_notifier *event_notifier;
2046
2047 desc = probe_desc->event_desc[i];
2048 if (!lttng_desc_match_enabler(desc,
2049 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)))
2050 continue;
2051
2052 /*
2053 * Check if already created.
2054 */
2055 head = utils_borrow_hash_table_bucket(
2056 event_notifier_group->event_notifiers_ht.table,
2057 LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->name);
2058 lttng_hlist_for_each_entry(event_notifier, head, hlist) {
2059 if (event_notifier->desc == desc
2060 && event_notifier->user_token == event_notifier_enabler->base.user_token)
2061 found = 1;
2062 }
2063 if (found)
2064 continue;
2065
2066 /*
2067 * We need to create a event_notifier for this event probe.
2068 */
2069 event_notifier = _lttng_event_notifier_create(desc,
2070 event_notifier_enabler->base.user_token,
2071 event_notifier_enabler->error_counter_index,
2072 event_notifier_group, NULL, NULL,
2073 LTTNG_KERNEL_TRACEPOINT);
2074 if (IS_ERR(event_notifier)) {
2075 printk(KERN_INFO "Unable to create event_notifier %s\n",
2076 probe_desc->event_desc[i]->name);
2077 }
2078 }
2079 }
2080 }
2081
2082 static
2083 void lttng_create_syscall_event_if_missing(struct lttng_event_enabler *event_enabler)
2084 {
2085 int ret;
2086
2087 ret = lttng_syscalls_register_event(event_enabler, NULL);
2088 WARN_ON_ONCE(ret);
2089 }
2090
2091 static
2092 void lttng_create_syscall_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2093 {
2094 int ret;
2095
2096 ret = lttng_syscalls_register_event_notifier(event_notifier_enabler, NULL);
2097 WARN_ON_ONCE(ret);
2098 ret = lttng_syscals_create_matching_event_notifiers(event_notifier_enabler, NULL);
2099 WARN_ON_ONCE(ret);
2100 }
2101
2102 /*
2103 * Create struct lttng_event if it is missing and present in the list of
2104 * tracepoint probes.
2105 * Should be called with sessions mutex held.
2106 */
2107 static
2108 void lttng_create_event_if_missing(struct lttng_event_enabler *event_enabler)
2109 {
2110 switch (event_enabler->base.event_param.instrumentation) {
2111 case LTTNG_KERNEL_TRACEPOINT:
2112 lttng_create_tracepoint_event_if_missing(event_enabler);
2113 break;
2114 case LTTNG_KERNEL_SYSCALL:
2115 lttng_create_syscall_event_if_missing(event_enabler);
2116 break;
2117 default:
2118 WARN_ON_ONCE(1);
2119 break;
2120 }
2121 }
2122
2123 /*
2124 * Create events associated with an event_enabler (if not already present),
2125 * and add backward reference from the event to the enabler.
2126 * Should be called with sessions mutex held.
2127 */
2128 static
2129 int lttng_event_enabler_ref_events(struct lttng_event_enabler *event_enabler)
2130 {
2131 struct lttng_channel *chan = event_enabler->chan;
2132 struct lttng_session *session = event_enabler->chan->session;
2133 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(event_enabler);
2134 struct lttng_event *event;
2135
2136 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_SYSCALL &&
2137 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_SYSCALL_ABI_ALL &&
2138 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_SYSCALL_MATCH_NAME &&
2139 !strcmp(base_enabler->event_param.name, "*")) {
2140 int enabled = base_enabler->enabled;
2141 enum lttng_kernel_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2142
2143 if (entryexit == LTTNG_KERNEL_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2144 WRITE_ONCE(chan->syscall_all_entry, enabled);
2145
2146 if (entryexit == LTTNG_KERNEL_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2147 WRITE_ONCE(chan->syscall_all_exit, enabled);
2148 }
2149
2150 /* First ensure that probe events are created for this enabler. */
2151 lttng_create_event_if_missing(event_enabler);
2152
2153 /* For each event matching event_enabler in session event list. */
2154 list_for_each_entry(event, &session->events, list) {
2155 struct lttng_enabler_ref *enabler_ref;
2156
2157 if (!lttng_event_enabler_match_event(event_enabler, event))
2158 continue;
2159 enabler_ref = lttng_enabler_ref(&event->enablers_ref_head,
2160 lttng_event_enabler_as_enabler(event_enabler));
2161 if (!enabler_ref) {
2162 /*
2163 * If no backward ref, create it.
2164 * Add backward ref from event to event_enabler.
2165 */
2166 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2167 if (!enabler_ref)
2168 return -ENOMEM;
2169 enabler_ref->ref = lttng_event_enabler_as_enabler(event_enabler);
2170 list_add(&enabler_ref->node,
2171 &event->enablers_ref_head);
2172 }
2173
2174 /*
2175 * Link filter bytecodes if not linked yet.
2176 */
2177 lttng_enabler_link_bytecode(event->desc,
2178 lttng_static_ctx,
2179 &event->filter_bytecode_runtime_head,
2180 &lttng_event_enabler_as_enabler(event_enabler)->filter_bytecode_head);
2181
2182 /* TODO: merge event context. */
2183 }
2184 return 0;
2185 }
2186
2187 /*
2188 * Create struct lttng_event_notifier if it is missing and present in the list of
2189 * tracepoint probes.
2190 * Should be called with sessions mutex held.
2191 */
2192 static
2193 void lttng_create_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2194 {
2195 switch (event_notifier_enabler->base.event_param.instrumentation) {
2196 case LTTNG_KERNEL_TRACEPOINT:
2197 lttng_create_tracepoint_event_notifier_if_missing(event_notifier_enabler);
2198 break;
2199 case LTTNG_KERNEL_SYSCALL:
2200 lttng_create_syscall_event_notifier_if_missing(event_notifier_enabler);
2201 break;
2202 default:
2203 WARN_ON_ONCE(1);
2204 break;
2205 }
2206 }
2207
2208 /*
2209 * Create event_notifiers associated with a event_notifier enabler (if not already present).
2210 */
2211 static
2212 int lttng_event_notifier_enabler_ref_event_notifiers(
2213 struct lttng_event_notifier_enabler *event_notifier_enabler)
2214 {
2215 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2216 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2217 struct lttng_event_notifier *event_notifier;
2218
2219 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_SYSCALL &&
2220 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_SYSCALL_ABI_ALL &&
2221 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_SYSCALL_MATCH_NAME &&
2222 !strcmp(base_enabler->event_param.name, "*")) {
2223
2224 int enabled = base_enabler->enabled;
2225 enum lttng_kernel_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2226
2227 if (entryexit == LTTNG_KERNEL_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2228 WRITE_ONCE(event_notifier_group->syscall_all_entry, enabled);
2229
2230 if (entryexit == LTTNG_KERNEL_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT)
2231 WRITE_ONCE(event_notifier_group->syscall_all_exit, enabled);
2232
2233 }
2234
2235 /* First ensure that probe event_notifiers are created for this enabler. */
2236 lttng_create_event_notifier_if_missing(event_notifier_enabler);
2237
2238 /* Link the created event_notifier with its associated enabler. */
2239 list_for_each_entry(event_notifier, &event_notifier_group->event_notifiers_head, list) {
2240 struct lttng_enabler_ref *enabler_ref;
2241
2242 if (!lttng_event_notifier_enabler_match_event_notifier(event_notifier_enabler, event_notifier))
2243 continue;
2244
2245 enabler_ref = lttng_enabler_ref(&event_notifier->enablers_ref_head,
2246 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2247 if (!enabler_ref) {
2248 /*
2249 * If no backward ref, create it.
2250 * Add backward ref from event_notifier to enabler.
2251 */
2252 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2253 if (!enabler_ref)
2254 return -ENOMEM;
2255
2256 enabler_ref->ref = lttng_event_notifier_enabler_as_enabler(
2257 event_notifier_enabler);
2258 list_add(&enabler_ref->node,
2259 &event_notifier->enablers_ref_head);
2260 }
2261
2262 /*
2263 * Link filter bytecodes if not linked yet.
2264 */
2265 lttng_enabler_link_bytecode(event_notifier->desc,
2266 lttng_static_ctx, &event_notifier->filter_bytecode_runtime_head,
2267 &lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->filter_bytecode_head);
2268
2269 /* Link capture bytecodes if not linked yet. */
2270 lttng_enabler_link_bytecode(event_notifier->desc,
2271 lttng_static_ctx, &event_notifier->capture_bytecode_runtime_head,
2272 &event_notifier_enabler->capture_bytecode_head);
2273
2274 event_notifier->num_captures = event_notifier_enabler->num_captures;
2275 }
2276 return 0;
2277 }
2278
2279 /*
2280 * Called at module load: connect the probe on all enablers matching
2281 * this event.
2282 * Called with sessions lock held.
2283 */
2284 int lttng_fix_pending_events(void)
2285 {
2286 struct lttng_session *session;
2287
2288 list_for_each_entry(session, &sessions, list)
2289 lttng_session_lazy_sync_event_enablers(session);
2290 return 0;
2291 }
2292
2293 static bool lttng_event_notifier_group_has_active_event_notifiers(
2294 struct lttng_event_notifier_group *event_notifier_group)
2295 {
2296 struct lttng_event_notifier_enabler *event_notifier_enabler;
2297
2298 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head,
2299 node) {
2300 if (event_notifier_enabler->base.enabled)
2301 return true;
2302 }
2303 return false;
2304 }
2305
2306 bool lttng_event_notifier_active(void)
2307 {
2308 struct lttng_event_notifier_group *event_notifier_group;
2309
2310 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2311 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2312 return true;
2313 }
2314 return false;
2315 }
2316
2317 int lttng_fix_pending_event_notifiers(void)
2318 {
2319 struct lttng_event_notifier_group *event_notifier_group;
2320
2321 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2322 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2323 return 0;
2324 }
2325
2326 struct lttng_event_enabler *lttng_event_enabler_create(
2327 enum lttng_enabler_format_type format_type,
2328 struct lttng_kernel_event *event_param,
2329 struct lttng_channel *chan)
2330 {
2331 struct lttng_event_enabler *event_enabler;
2332
2333 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2334 if (!event_enabler)
2335 return NULL;
2336 event_enabler->base.format_type = format_type;
2337 INIT_LIST_HEAD(&event_enabler->base.filter_bytecode_head);
2338 memcpy(&event_enabler->base.event_param, event_param,
2339 sizeof(event_enabler->base.event_param));
2340 event_enabler->chan = chan;
2341 /* ctx left NULL */
2342 event_enabler->base.enabled = 0;
2343 event_enabler->base.evtype = LTTNG_TYPE_ENABLER;
2344 mutex_lock(&sessions_mutex);
2345 list_add(&event_enabler->node, &event_enabler->chan->session->enablers_head);
2346 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2347 mutex_unlock(&sessions_mutex);
2348 return event_enabler;
2349 }
2350
2351 int lttng_event_enabler_enable(struct lttng_event_enabler *event_enabler)
2352 {
2353 mutex_lock(&sessions_mutex);
2354 lttng_event_enabler_as_enabler(event_enabler)->enabled = 1;
2355 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2356 mutex_unlock(&sessions_mutex);
2357 return 0;
2358 }
2359
2360 int lttng_event_enabler_disable(struct lttng_event_enabler *event_enabler)
2361 {
2362 mutex_lock(&sessions_mutex);
2363 lttng_event_enabler_as_enabler(event_enabler)->enabled = 0;
2364 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2365 mutex_unlock(&sessions_mutex);
2366 return 0;
2367 }
2368
2369 static
2370 int lttng_enabler_attach_filter_bytecode(struct lttng_enabler *enabler,
2371 struct lttng_kernel_filter_bytecode __user *bytecode)
2372 {
2373 struct lttng_bytecode_node *bytecode_node;
2374 uint32_t bytecode_len;
2375 int ret;
2376
2377 ret = get_user(bytecode_len, &bytecode->len);
2378 if (ret)
2379 return ret;
2380 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2381 GFP_KERNEL);
2382 if (!bytecode_node)
2383 return -ENOMEM;
2384 ret = copy_from_user(&bytecode_node->bc, bytecode,
2385 sizeof(*bytecode) + bytecode_len);
2386 if (ret)
2387 goto error_free;
2388
2389 bytecode_node->type = LTTNG_BYTECODE_NODE_TYPE_FILTER;
2390 bytecode_node->enabler = enabler;
2391 /* Enforce length based on allocated size */
2392 bytecode_node->bc.len = bytecode_len;
2393 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2394
2395 return 0;
2396
2397 error_free:
2398 lttng_kvfree(bytecode_node);
2399 return ret;
2400 }
2401
2402 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler *event_enabler,
2403 struct lttng_kernel_filter_bytecode __user *bytecode)
2404 {
2405 int ret;
2406 ret = lttng_enabler_attach_filter_bytecode(
2407 lttng_event_enabler_as_enabler(event_enabler), bytecode);
2408 if (ret)
2409 goto error;
2410
2411 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2412 return 0;
2413
2414 error:
2415 return ret;
2416 }
2417
2418 int lttng_event_add_callsite(struct lttng_event *event,
2419 struct lttng_kernel_event_callsite __user *callsite)
2420 {
2421
2422 switch (event->instrumentation) {
2423 case LTTNG_KERNEL_UPROBE:
2424 return lttng_uprobes_event_add_callsite(event, callsite);
2425 default:
2426 return -EINVAL;
2427 }
2428 }
2429
2430 int lttng_event_enabler_attach_context(struct lttng_event_enabler *event_enabler,
2431 struct lttng_kernel_context *context_param)
2432 {
2433 return -ENOSYS;
2434 }
2435
2436 static
2437 void lttng_enabler_destroy(struct lttng_enabler *enabler)
2438 {
2439 struct lttng_bytecode_node *filter_node, *tmp_filter_node;
2440
2441 /* Destroy filter bytecode */
2442 list_for_each_entry_safe(filter_node, tmp_filter_node,
2443 &enabler->filter_bytecode_head, node) {
2444 lttng_kvfree(filter_node);
2445 }
2446 }
2447
2448 static
2449 void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler)
2450 {
2451 lttng_enabler_destroy(lttng_event_enabler_as_enabler(event_enabler));
2452
2453 /* Destroy contexts */
2454 lttng_destroy_context(event_enabler->ctx);
2455
2456 list_del(&event_enabler->node);
2457 kfree(event_enabler);
2458 }
2459
2460 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2461 struct lttng_event_notifier_group *event_notifier_group,
2462 enum lttng_enabler_format_type format_type,
2463 struct lttng_kernel_event_notifier *event_notifier_param)
2464 {
2465 struct lttng_event_notifier_enabler *event_notifier_enabler;
2466
2467 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2468 if (!event_notifier_enabler)
2469 return NULL;
2470
2471 event_notifier_enabler->base.format_type = format_type;
2472 INIT_LIST_HEAD(&event_notifier_enabler->base.filter_bytecode_head);
2473 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2474
2475 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2476 event_notifier_enabler->num_captures = 0;
2477
2478 memcpy(&event_notifier_enabler->base.event_param, &event_notifier_param->event,
2479 sizeof(event_notifier_enabler->base.event_param));
2480 event_notifier_enabler->base.evtype = LTTNG_TYPE_ENABLER;
2481
2482 event_notifier_enabler->base.enabled = 0;
2483 event_notifier_enabler->base.user_token = event_notifier_param->event.token;
2484 event_notifier_enabler->group = event_notifier_group;
2485
2486 mutex_lock(&sessions_mutex);
2487 list_add(&event_notifier_enabler->node, &event_notifier_enabler->group->enablers_head);
2488 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2489
2490 mutex_unlock(&sessions_mutex);
2491
2492 return event_notifier_enabler;
2493 }
2494
2495 int lttng_event_notifier_enabler_enable(
2496 struct lttng_event_notifier_enabler *event_notifier_enabler)
2497 {
2498 mutex_lock(&sessions_mutex);
2499 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2500 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2501 mutex_unlock(&sessions_mutex);
2502 return 0;
2503 }
2504
2505 int lttng_event_notifier_enabler_disable(
2506 struct lttng_event_notifier_enabler *event_notifier_enabler)
2507 {
2508 mutex_lock(&sessions_mutex);
2509 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2510 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2511 mutex_unlock(&sessions_mutex);
2512 return 0;
2513 }
2514
2515 int lttng_event_notifier_enabler_attach_filter_bytecode(
2516 struct lttng_event_notifier_enabler *event_notifier_enabler,
2517 struct lttng_kernel_filter_bytecode __user *bytecode)
2518 {
2519 int ret;
2520
2521 ret = lttng_enabler_attach_filter_bytecode(
2522 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler),
2523 bytecode);
2524 if (ret)
2525 goto error;
2526
2527 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2528 return 0;
2529
2530 error:
2531 return ret;
2532 }
2533
2534 int lttng_event_notifier_enabler_attach_capture_bytecode(
2535 struct lttng_event_notifier_enabler *event_notifier_enabler,
2536 struct lttng_kernel_capture_bytecode __user *bytecode)
2537 {
2538 struct lttng_bytecode_node *bytecode_node;
2539 struct lttng_enabler *enabler =
2540 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2541 uint32_t bytecode_len;
2542 int ret;
2543
2544 ret = get_user(bytecode_len, &bytecode->len);
2545 if (ret)
2546 return ret;
2547
2548 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2549 GFP_KERNEL);
2550 if (!bytecode_node)
2551 return -ENOMEM;
2552
2553 ret = copy_from_user(&bytecode_node->bc, bytecode,
2554 sizeof(*bytecode) + bytecode_len);
2555 if (ret)
2556 goto error_free;
2557
2558 bytecode_node->type = LTTNG_BYTECODE_NODE_TYPE_CAPTURE;
2559 bytecode_node->enabler = enabler;
2560
2561 /* Enforce length based on allocated size */
2562 bytecode_node->bc.len = bytecode_len;
2563 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2564
2565 event_notifier_enabler->num_captures++;
2566
2567 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2568 goto end;
2569
2570 error_free:
2571 lttng_kvfree(bytecode_node);
2572 end:
2573 return ret;
2574 }
2575
2576 int lttng_event_notifier_add_callsite(struct lttng_event_notifier *event_notifier,
2577 struct lttng_kernel_event_callsite __user *callsite)
2578 {
2579
2580 switch (event_notifier->instrumentation) {
2581 case LTTNG_KERNEL_UPROBE:
2582 return lttng_uprobes_event_notifier_add_callsite(event_notifier,
2583 callsite);
2584 default:
2585 return -EINVAL;
2586 }
2587 }
2588
2589 int lttng_event_notifier_enabler_attach_context(
2590 struct lttng_event_notifier_enabler *event_notifier_enabler,
2591 struct lttng_kernel_context *context_param)
2592 {
2593 return -ENOSYS;
2594 }
2595
2596 static
2597 void lttng_event_notifier_enabler_destroy(
2598 struct lttng_event_notifier_enabler *event_notifier_enabler)
2599 {
2600 if (!event_notifier_enabler) {
2601 return;
2602 }
2603
2604 list_del(&event_notifier_enabler->node);
2605
2606 lttng_enabler_destroy(lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2607 kfree(event_notifier_enabler);
2608 }
2609
2610 /*
2611 * lttng_session_sync_event_enablers should be called just before starting a
2612 * session.
2613 * Should be called with sessions mutex held.
2614 */
2615 static
2616 void lttng_session_sync_event_enablers(struct lttng_session *session)
2617 {
2618 struct lttng_event_enabler *event_enabler;
2619 struct lttng_event *event;
2620
2621 list_for_each_entry(event_enabler, &session->enablers_head, node)
2622 lttng_event_enabler_ref_events(event_enabler);
2623 /*
2624 * For each event, if at least one of its enablers is enabled,
2625 * and its channel and session transient states are enabled, we
2626 * enable the event, else we disable it.
2627 */
2628 list_for_each_entry(event, &session->events, list) {
2629 struct lttng_enabler_ref *enabler_ref;
2630 struct lttng_bytecode_runtime *runtime;
2631 int enabled = 0, has_enablers_without_bytecode = 0;
2632
2633 switch (event->instrumentation) {
2634 case LTTNG_KERNEL_TRACEPOINT:
2635 case LTTNG_KERNEL_SYSCALL:
2636 /* Enable events */
2637 list_for_each_entry(enabler_ref,
2638 &event->enablers_ref_head, node) {
2639 if (enabler_ref->ref->enabled) {
2640 enabled = 1;
2641 break;
2642 }
2643 }
2644 break;
2645 default:
2646 /* Not handled with lazy sync. */
2647 continue;
2648 }
2649 /*
2650 * Enabled state is based on union of enablers, with
2651 * intesection of session and channel transient enable
2652 * states.
2653 */
2654 enabled = enabled && session->tstate && event->chan->tstate;
2655
2656 WRITE_ONCE(event->enabled, enabled);
2657 /*
2658 * Sync tracepoint registration with event enabled
2659 * state.
2660 */
2661 if (enabled) {
2662 register_event(event);
2663 } else {
2664 _lttng_event_unregister(event);
2665 }
2666
2667 /* Check if has enablers without bytecode enabled */
2668 list_for_each_entry(enabler_ref,
2669 &event->enablers_ref_head, node) {
2670 if (enabler_ref->ref->enabled
2671 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2672 has_enablers_without_bytecode = 1;
2673 break;
2674 }
2675 }
2676 event->has_enablers_without_bytecode =
2677 has_enablers_without_bytecode;
2678
2679 /* Enable filters */
2680 list_for_each_entry(runtime,
2681 &event->filter_bytecode_runtime_head, node)
2682 lttng_bytecode_filter_sync_state(runtime);
2683 }
2684 }
2685
2686 /*
2687 * Apply enablers to session events, adding events to session if need
2688 * be. It is required after each modification applied to an active
2689 * session, and right before session "start".
2690 * "lazy" sync means we only sync if required.
2691 * Should be called with sessions mutex held.
2692 */
2693 static
2694 void lttng_session_lazy_sync_event_enablers(struct lttng_session *session)
2695 {
2696 /* We can skip if session is not active */
2697 if (!session->active)
2698 return;
2699 lttng_session_sync_event_enablers(session);
2700 }
2701
2702 static
2703 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2704 {
2705 struct lttng_event_notifier_enabler *event_notifier_enabler;
2706 struct lttng_event_notifier *event_notifier;
2707
2708 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head, node)
2709 lttng_event_notifier_enabler_ref_event_notifiers(event_notifier_enabler);
2710
2711 /*
2712 * For each event_notifier, if at least one of its enablers is enabled,
2713 * we enable the event_notifier, else we disable it.
2714 */
2715 list_for_each_entry(event_notifier, &event_notifier_group->event_notifiers_head, list) {
2716 struct lttng_enabler_ref *enabler_ref;
2717 struct lttng_bytecode_runtime *runtime;
2718 int enabled = 0, has_enablers_without_bytecode = 0;
2719
2720 switch (event_notifier->instrumentation) {
2721 case LTTNG_KERNEL_TRACEPOINT:
2722 case LTTNG_KERNEL_SYSCALL:
2723 /* Enable event_notifiers */
2724 list_for_each_entry(enabler_ref,
2725 &event_notifier->enablers_ref_head, node) {
2726 if (enabler_ref->ref->enabled) {
2727 enabled = 1;
2728 break;
2729 }
2730 }
2731 break;
2732 default:
2733 /* Not handled with sync. */
2734 continue;
2735 }
2736
2737 WRITE_ONCE(event_notifier->enabled, enabled);
2738 /*
2739 * Sync tracepoint registration with event_notifier enabled
2740 * state.
2741 */
2742 if (enabled) {
2743 if (!event_notifier->registered)
2744 register_event_notifier(event_notifier);
2745 } else {
2746 if (event_notifier->registered)
2747 _lttng_event_notifier_unregister(event_notifier);
2748 }
2749
2750 /* Check if has enablers without bytecode enabled */
2751 list_for_each_entry(enabler_ref,
2752 &event_notifier->enablers_ref_head, node) {
2753 if (enabler_ref->ref->enabled
2754 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2755 has_enablers_without_bytecode = 1;
2756 break;
2757 }
2758 }
2759 event_notifier->has_enablers_without_bytecode =
2760 has_enablers_without_bytecode;
2761
2762 /* Enable filters */
2763 list_for_each_entry(runtime,
2764 &event_notifier->filter_bytecode_runtime_head, node)
2765 lttng_bytecode_filter_sync_state(runtime);
2766
2767 /* Enable captures */
2768 list_for_each_entry(runtime,
2769 &event_notifier->capture_bytecode_runtime_head, node)
2770 lttng_bytecode_capture_sync_state(runtime);
2771
2772 WRITE_ONCE(event_notifier->eval_capture, !!event_notifier->num_captures);
2773 }
2774 }
2775
2776 /*
2777 * Serialize at most one packet worth of metadata into a metadata
2778 * channel.
2779 * We grab the metadata cache mutex to get exclusive access to our metadata
2780 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2781 * allows us to do racy operations such as looking for remaining space left in
2782 * packet and write, since mutual exclusion protects us from concurrent writes.
2783 * Mutual exclusion on the metadata cache allow us to read the cache content
2784 * without racing against reallocation of the cache by updates.
2785 * Returns the number of bytes written in the channel, 0 if no data
2786 * was written and a negative value on error.
2787 */
2788 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2789 struct channel *chan, bool *coherent)
2790 {
2791 struct lib_ring_buffer_ctx ctx;
2792 int ret = 0;
2793 size_t len, reserve_len;
2794
2795 /*
2796 * Ensure we support mutiple get_next / put sequences followed by
2797 * put_next. The metadata cache lock protects reading the metadata
2798 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2799 * "flush" operations on the buffer invoked by different processes.
2800 * Moreover, since the metadata cache memory can be reallocated, we
2801 * need to have exclusive access against updates even though we only
2802 * read it.
2803 */
2804 mutex_lock(&stream->metadata_cache->lock);
2805 WARN_ON(stream->metadata_in < stream->metadata_out);
2806 if (stream->metadata_in != stream->metadata_out)
2807 goto end;
2808
2809 /* Metadata regenerated, change the version. */
2810 if (stream->metadata_cache->version != stream->version)
2811 stream->version = stream->metadata_cache->version;
2812
2813 len = stream->metadata_cache->metadata_written -
2814 stream->metadata_in;
2815 if (!len)
2816 goto end;
2817 reserve_len = min_t(size_t,
2818 stream->transport->ops.packet_avail_size(chan),
2819 len);
2820 lib_ring_buffer_ctx_init(&ctx, chan, NULL, reserve_len,
2821 sizeof(char), -1);
2822 /*
2823 * If reservation failed, return an error to the caller.
2824 */
2825 ret = stream->transport->ops.event_reserve(&ctx, 0);
2826 if (ret != 0) {
2827 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2828 stream->coherent = false;
2829 goto end;
2830 }
2831 stream->transport->ops.event_write(&ctx,
2832 stream->metadata_cache->data + stream->metadata_in,
2833 reserve_len);
2834 stream->transport->ops.event_commit(&ctx);
2835 stream->metadata_in += reserve_len;
2836 if (reserve_len < len)
2837 stream->coherent = false;
2838 else
2839 stream->coherent = true;
2840 ret = reserve_len;
2841
2842 end:
2843 if (coherent)
2844 *coherent = stream->coherent;
2845 mutex_unlock(&stream->metadata_cache->lock);
2846 return ret;
2847 }
2848
2849 static
2850 void lttng_metadata_begin(struct lttng_session *session)
2851 {
2852 if (atomic_inc_return(&session->metadata_cache->producing) == 1)
2853 mutex_lock(&session->metadata_cache->lock);
2854 }
2855
2856 static
2857 void lttng_metadata_end(struct lttng_session *session)
2858 {
2859 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
2860 if (atomic_dec_return(&session->metadata_cache->producing) == 0) {
2861 struct lttng_metadata_stream *stream;
2862
2863 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
2864 wake_up_interruptible(&stream->read_wait);
2865 mutex_unlock(&session->metadata_cache->lock);
2866 }
2867 }
2868
2869 /*
2870 * Write the metadata to the metadata cache.
2871 * Must be called with sessions_mutex held.
2872 * The metadata cache lock protects us from concurrent read access from
2873 * thread outputting metadata content to ring buffer.
2874 * The content of the printf is printed as a single atomic metadata
2875 * transaction.
2876 */
2877 int lttng_metadata_printf(struct lttng_session *session,
2878 const char *fmt, ...)
2879 {
2880 char *str;
2881 size_t len;
2882 va_list ap;
2883
2884 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
2885
2886 va_start(ap, fmt);
2887 str = kvasprintf(GFP_KERNEL, fmt, ap);
2888 va_end(ap);
2889 if (!str)
2890 return -ENOMEM;
2891
2892 len = strlen(str);
2893 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
2894 if (session->metadata_cache->metadata_written + len >
2895 session->metadata_cache->cache_alloc) {
2896 char *tmp_cache_realloc;
2897 unsigned int tmp_cache_alloc_size;
2898
2899 tmp_cache_alloc_size = max_t(unsigned int,
2900 session->metadata_cache->cache_alloc + len,
2901 session->metadata_cache->cache_alloc << 1);
2902 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
2903 if (!tmp_cache_realloc)
2904 goto err;
2905 if (session->metadata_cache->data) {
2906 memcpy(tmp_cache_realloc,
2907 session->metadata_cache->data,
2908 session->metadata_cache->cache_alloc);
2909 vfree(session->metadata_cache->data);
2910 }
2911
2912 session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
2913 session->metadata_cache->data = tmp_cache_realloc;
2914 }
2915 memcpy(session->metadata_cache->data +
2916 session->metadata_cache->metadata_written,
2917 str, len);
2918 session->metadata_cache->metadata_written += len;
2919 kfree(str);
2920
2921 return 0;
2922
2923 err:
2924 kfree(str);
2925 return -ENOMEM;
2926 }
2927
2928 static
2929 int print_tabs(struct lttng_session *session, size_t nesting)
2930 {
2931 size_t i;
2932
2933 for (i = 0; i < nesting; i++) {
2934 int ret;
2935
2936 ret = lttng_metadata_printf(session, " ");
2937 if (ret) {
2938 return ret;
2939 }
2940 }
2941 return 0;
2942 }
2943
2944 static
2945 int lttng_field_name_statedump(struct lttng_session *session,
2946 const struct lttng_event_field *field,
2947 size_t nesting)
2948 {
2949 return lttng_metadata_printf(session, " _%s;\n", field->name);
2950 }
2951
2952 static
2953 int _lttng_integer_type_statedump(struct lttng_session *session,
2954 const struct lttng_type *type,
2955 size_t nesting)
2956 {
2957 int ret;
2958
2959 WARN_ON_ONCE(type->atype != atype_integer);
2960 ret = print_tabs(session, nesting);
2961 if (ret)
2962 return ret;
2963 ret = lttng_metadata_printf(session,
2964 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
2965 type->u.integer.size,
2966 type->u.integer.alignment,
2967 type->u.integer.signedness,
2968 (type->u.integer.encoding == lttng_encode_none)
2969 ? "none"
2970 : (type->u.integer.encoding == lttng_encode_UTF8)
2971 ? "UTF8"
2972 : "ASCII",
2973 type->u.integer.base,
2974 #if __BYTE_ORDER == __BIG_ENDIAN
2975 type->u.integer.reverse_byte_order ? " byte_order = le;" : ""
2976 #else
2977 type->u.integer.reverse_byte_order ? " byte_order = be;" : ""
2978 #endif
2979 );
2980 return ret;
2981 }
2982
2983 /*
2984 * Must be called with sessions_mutex held.
2985 */
2986 static
2987 int _lttng_struct_type_statedump(struct lttng_session *session,
2988 const struct lttng_type *type,
2989 size_t nesting)
2990 {
2991 int ret;
2992 uint32_t i, nr_fields;
2993 unsigned int alignment;
2994
2995 WARN_ON_ONCE(type->atype != atype_struct_nestable);
2996
2997 ret = print_tabs(session, nesting);
2998 if (ret)
2999 return ret;
3000 ret = lttng_metadata_printf(session,
3001 "struct {\n");
3002 if (ret)
3003 return ret;
3004 nr_fields = type->u.struct_nestable.nr_fields;
3005 for (i = 0; i < nr_fields; i++) {
3006 const struct lttng_event_field *iter_field;
3007
3008 iter_field = &type->u.struct_nestable.fields[i];
3009 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
3010 if (ret)
3011 return ret;
3012 }
3013 ret = print_tabs(session, nesting);
3014 if (ret)
3015 return ret;
3016 alignment = type->u.struct_nestable.alignment;
3017 if (alignment) {
3018 ret = lttng_metadata_printf(session,
3019 "} align(%u)",
3020 alignment);
3021 } else {
3022 ret = lttng_metadata_printf(session,
3023 "}");
3024 }
3025 return ret;
3026 }
3027
3028 /*
3029 * Must be called with sessions_mutex held.
3030 */
3031 static
3032 int _lttng_struct_field_statedump(struct lttng_session *session,
3033 const struct lttng_event_field *field,
3034 size_t nesting)
3035 {
3036 int ret;
3037
3038 ret = _lttng_struct_type_statedump(session,
3039 &field->type, nesting);
3040 if (ret)
3041 return ret;
3042 return lttng_field_name_statedump(session, field, nesting);
3043 }
3044
3045 /*
3046 * Must be called with sessions_mutex held.
3047 */
3048 static
3049 int _lttng_variant_type_statedump(struct lttng_session *session,
3050 const struct lttng_type *type,
3051 size_t nesting)
3052 {
3053 int ret;
3054 uint32_t i, nr_choices;
3055
3056 WARN_ON_ONCE(type->atype != atype_variant_nestable);
3057 /*
3058 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3059 */
3060 if (type->u.variant_nestable.alignment != 0)
3061 return -EINVAL;
3062 ret = print_tabs(session, nesting);
3063 if (ret)
3064 return ret;
3065 ret = lttng_metadata_printf(session,
3066 "variant <_%s> {\n",
3067 type->u.variant_nestable.tag_name);
3068 if (ret)
3069 return ret;
3070 nr_choices = type->u.variant_nestable.nr_choices;
3071 for (i = 0; i < nr_choices; i++) {
3072 const struct lttng_event_field *iter_field;
3073
3074 iter_field = &type->u.variant_nestable.choices[i];
3075 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
3076 if (ret)
3077 return ret;
3078 }
3079 ret = print_tabs(session, nesting);
3080 if (ret)
3081 return ret;
3082 ret = lttng_metadata_printf(session,
3083 "}");
3084 return ret;
3085 }
3086
3087 /*
3088 * Must be called with sessions_mutex held.
3089 */
3090 static
3091 int _lttng_variant_field_statedump(struct lttng_session *session,
3092 const struct lttng_event_field *field,
3093 size_t nesting)
3094 {
3095 int ret;
3096
3097 ret = _lttng_variant_type_statedump(session,
3098 &field->type, nesting);
3099 if (ret)
3100 return ret;
3101 return lttng_field_name_statedump(session, field, nesting);
3102 }
3103
3104 /*
3105 * Must be called with sessions_mutex held.
3106 */
3107 static
3108 int _lttng_array_field_statedump(struct lttng_session *session,
3109 const struct lttng_event_field *field,
3110 size_t nesting)
3111 {
3112 int ret;
3113 const struct lttng_type *elem_type;
3114
3115 WARN_ON_ONCE(field->type.atype != atype_array_nestable);
3116
3117 if (field->type.u.array_nestable.alignment) {
3118 ret = print_tabs(session, nesting);
3119 if (ret)
3120 return ret;
3121 ret = lttng_metadata_printf(session,
3122 "struct { } align(%u) _%s_padding;\n",
3123 field->type.u.array_nestable.alignment * CHAR_BIT,
3124 field->name);
3125 if (ret)
3126 return ret;
3127 }
3128 /*
3129 * Nested compound types: Only array of structures and variants are
3130 * currently supported.
3131 */
3132 elem_type = field->type.u.array_nestable.elem_type;
3133 switch (elem_type->atype) {
3134 case atype_integer:
3135 case atype_struct_nestable:
3136 case atype_variant_nestable:
3137 ret = _lttng_type_statedump(session, elem_type, nesting);
3138 if (ret)
3139 return ret;
3140 break;
3141
3142 default:
3143 return -EINVAL;
3144 }
3145 ret = lttng_metadata_printf(session,
3146 " _%s[%u];\n",
3147 field->name,
3148 field->type.u.array_nestable.length);
3149 return ret;
3150 }
3151
3152 /*
3153 * Must be called with sessions_mutex held.
3154 */
3155 static
3156 int _lttng_sequence_field_statedump(struct lttng_session *session,
3157 const struct lttng_event_field *field,
3158 size_t nesting)
3159 {
3160 int ret;
3161 const char *length_name;
3162 const struct lttng_type *elem_type;
3163
3164 WARN_ON_ONCE(field->type.atype != atype_sequence_nestable);
3165
3166 length_name = field->type.u.sequence_nestable.length_name;
3167
3168 if (field->type.u.sequence_nestable.alignment) {
3169 ret = print_tabs(session, nesting);
3170 if (ret)
3171 return ret;
3172 ret = lttng_metadata_printf(session,
3173 "struct { } align(%u) _%s_padding;\n",
3174 field->type.u.sequence_nestable.alignment * CHAR_BIT,
3175 field->name);
3176 if (ret)
3177 return ret;
3178 }
3179
3180 /*
3181 * Nested compound types: Only array of structures and variants are
3182 * currently supported.
3183 */
3184 elem_type = field->type.u.sequence_nestable.elem_type;
3185 switch (elem_type->atype) {
3186 case atype_integer:
3187 case atype_struct_nestable:
3188 case atype_variant_nestable:
3189 ret = _lttng_type_statedump(session, elem_type, nesting);
3190 if (ret)
3191 return ret;
3192 break;
3193
3194 default:
3195 return -EINVAL;
3196 }
3197 ret = lttng_metadata_printf(session,
3198 " _%s[ _%s ];\n",
3199 field->name,
3200 field->type.u.sequence_nestable.length_name);
3201 return ret;
3202 }
3203
3204 /*
3205 * Must be called with sessions_mutex held.
3206 */
3207 static
3208 int _lttng_enum_type_statedump(struct lttng_session *session,
3209 const struct lttng_type *type,
3210 size_t nesting)
3211 {
3212 const struct lttng_enum_desc *enum_desc;
3213 const struct lttng_type *container_type;
3214 int ret;
3215 unsigned int i, nr_entries;
3216
3217 container_type = type->u.enum_nestable.container_type;
3218 if (container_type->atype != atype_integer) {
3219 ret = -EINVAL;
3220 goto end;
3221 }
3222 enum_desc = type->u.enum_nestable.desc;
3223 nr_entries = enum_desc->nr_entries;
3224
3225 ret = print_tabs(session, nesting);
3226 if (ret)
3227 goto end;
3228 ret = lttng_metadata_printf(session, "enum : ");
3229 if (ret)
3230 goto end;
3231 ret = _lttng_integer_type_statedump(session, container_type, 0);
3232 if (ret)
3233 goto end;
3234 ret = lttng_metadata_printf(session, " {\n");
3235 if (ret)
3236 goto end;
3237 /* Dump all entries */
3238 for (i = 0; i < nr_entries; i++) {
3239 const struct lttng_enum_entry *entry = &enum_desc->entries[i];
3240 int j, len;
3241
3242 ret = print_tabs(session, nesting + 1);
3243 if (ret)
3244 goto end;
3245 ret = lttng_metadata_printf(session,
3246 "\"");
3247 if (ret)
3248 goto end;
3249 len = strlen(entry->string);
3250 /* Escape the character '"' */
3251 for (j = 0; j < len; j++) {
3252 char c = entry->string[j];
3253
3254 switch (c) {
3255 case '"':
3256 ret = lttng_metadata_printf(session,
3257 "\\\"");
3258 break;
3259 case '\\':
3260 ret = lttng_metadata_printf(session,
3261 "\\\\");
3262 break;
3263 default:
3264 ret = lttng_metadata_printf(session,
3265 "%c", c);
3266 break;
3267 }
3268 if (ret)
3269 goto end;
3270 }
3271 ret = lttng_metadata_printf(session, "\"");
3272 if (ret)
3273 goto end;
3274
3275 if (entry->options.is_auto) {
3276 ret = lttng_metadata_printf(session, ",\n");
3277 if (ret)
3278 goto end;
3279 } else {
3280 ret = lttng_metadata_printf(session,
3281 " = ");
3282 if (ret)
3283 goto end;
3284 if (entry->start.signedness)
3285 ret = lttng_metadata_printf(session,
3286 "%lld", (long long) entry->start.value);
3287 else
3288 ret = lttng_metadata_printf(session,
3289 "%llu", entry->start.value);
3290 if (ret)
3291 goto end;
3292 if (entry->start.signedness == entry->end.signedness &&
3293 entry->start.value
3294 == entry->end.value) {
3295 ret = lttng_metadata_printf(session,
3296 ",\n");
3297 } else {
3298 if (entry->end.signedness) {
3299 ret = lttng_metadata_printf(session,
3300 " ... %lld,\n",
3301 (long long) entry->end.value);
3302 } else {
3303 ret = lttng_metadata_printf(session,
3304 " ... %llu,\n",
3305 entry->end.value);
3306 }
3307 }
3308 if (ret)
3309 goto end;
3310 }
3311 }
3312 ret = print_tabs(session, nesting);
3313 if (ret)
3314 goto end;
3315 ret = lttng_metadata_printf(session, "}");
3316 end:
3317 return ret;
3318 }
3319
3320 /*
3321 * Must be called with sessions_mutex held.
3322 */
3323 static
3324 int _lttng_enum_field_statedump(struct lttng_session *session,
3325 const struct lttng_event_field *field,
3326 size_t nesting)
3327 {
3328 int ret;
3329
3330 ret = _lttng_enum_type_statedump(session, &field->type, nesting);
3331 if (ret)
3332 return ret;
3333 return lttng_field_name_statedump(session, field, nesting);
3334 }
3335
3336 static
3337 int _lttng_integer_field_statedump(struct lttng_session *session,
3338 const struct lttng_event_field *field,
3339 size_t nesting)
3340 {
3341 int ret;
3342
3343 ret = _lttng_integer_type_statedump(session, &field->type, nesting);
3344 if (ret)
3345 return ret;
3346 return lttng_field_name_statedump(session, field, nesting);
3347 }
3348
3349 static
3350 int _lttng_string_type_statedump(struct lttng_session *session,
3351 const struct lttng_type *type,
3352 size_t nesting)
3353 {
3354 int ret;
3355
3356 WARN_ON_ONCE(type->atype != atype_string);
3357 /* Default encoding is UTF8 */
3358 ret = print_tabs(session, nesting);
3359 if (ret)
3360 return ret;
3361 ret = lttng_metadata_printf(session,
3362 "string%s",
3363 type->u.string.encoding == lttng_encode_ASCII ?
3364 " { encoding = ASCII; }" : "");
3365 return ret;
3366 }
3367
3368 static
3369 int _lttng_string_field_statedump(struct lttng_session *session,
3370 const struct lttng_event_field *field,
3371 size_t nesting)
3372 {
3373 int ret;
3374
3375 WARN_ON_ONCE(field->type.atype != atype_string);
3376 ret = _lttng_string_type_statedump(session, &field->type, nesting);
3377 if (ret)
3378 return ret;
3379 return lttng_field_name_statedump(session, field, nesting);
3380 }
3381
3382 /*
3383 * Must be called with sessions_mutex held.
3384 */
3385 static
3386 int _lttng_type_statedump(struct lttng_session *session,
3387 const struct lttng_type *type,
3388 size_t nesting)
3389 {
3390 int ret = 0;
3391
3392 switch (type->atype) {
3393 case atype_integer:
3394 ret = _lttng_integer_type_statedump(session, type, nesting);
3395 break;
3396 case atype_enum_nestable:
3397 ret = _lttng_enum_type_statedump(session, type, nesting);
3398 break;
3399 case atype_string:
3400 ret = _lttng_string_type_statedump(session, type, nesting);
3401 break;
3402 case atype_struct_nestable:
3403 ret = _lttng_struct_type_statedump(session, type, nesting);
3404 break;
3405 case atype_variant_nestable:
3406 ret = _lttng_variant_type_statedump(session, type, nesting);
3407 break;
3408
3409 /* Nested arrays and sequences are not supported yet. */
3410 case atype_array_nestable:
3411 case atype_sequence_nestable:
3412 default:
3413 WARN_ON_ONCE(1);
3414 return -EINVAL;
3415 }
3416 return ret;
3417 }
3418
3419 /*
3420 * Must be called with sessions_mutex held.
3421 */
3422 static
3423 int _lttng_field_statedump(struct lttng_session *session,
3424 const struct lttng_event_field *field,
3425 size_t nesting)
3426 {
3427 int ret = 0;
3428
3429 switch (field->type.atype) {
3430 case atype_integer:
3431 ret = _lttng_integer_field_statedump(session, field, nesting);
3432 break;
3433 case atype_enum_nestable:
3434 ret = _lttng_enum_field_statedump(session, field, nesting);
3435 break;
3436 case atype_string:
3437 ret = _lttng_string_field_statedump(session, field, nesting);
3438 break;
3439 case atype_struct_nestable:
3440 ret = _lttng_struct_field_statedump(session, field, nesting);
3441 break;
3442 case atype_array_nestable:
3443 ret = _lttng_array_field_statedump(session, field, nesting);
3444 break;
3445 case atype_sequence_nestable:
3446 ret = _lttng_sequence_field_statedump(session, field, nesting);
3447 break;
3448 case atype_variant_nestable:
3449 ret = _lttng_variant_field_statedump(session, field, nesting);
3450 break;
3451
3452 default:
3453 WARN_ON_ONCE(1);
3454 return -EINVAL;
3455 }
3456 return ret;
3457 }
3458
3459 static
3460 int _lttng_context_metadata_statedump(struct lttng_session *session,
3461 struct lttng_ctx *ctx)
3462 {
3463 int ret = 0;
3464 int i;
3465
3466 if (!ctx)
3467 return 0;
3468 for (i = 0; i < ctx->nr_fields; i++) {
3469 const struct lttng_ctx_field *field = &ctx->fields[i];
3470
3471 ret = _lttng_field_statedump(session, &field->event_field, 2);
3472 if (ret)
3473 return ret;
3474 }
3475 return ret;
3476 }
3477
3478 static
3479 int _lttng_fields_metadata_statedump(struct lttng_session *session,
3480 struct lttng_event *event)
3481 {
3482 const struct lttng_event_desc *desc = event->desc;
3483 int ret = 0;
3484 int i;
3485
3486 for (i = 0; i < desc->nr_fields; i++) {
3487 const struct lttng_event_field *field = &desc->fields[i];
3488
3489 ret = _lttng_field_statedump(session, field, 2);
3490 if (ret)
3491 return ret;
3492 }
3493 return ret;
3494 }
3495
3496 /*
3497 * Must be called with sessions_mutex held.
3498 * The entire event metadata is printed as a single atomic metadata
3499 * transaction.
3500 */
3501 static
3502 int _lttng_event_metadata_statedump(struct lttng_session *session,
3503 struct lttng_channel *chan,
3504 struct lttng_event *event)
3505 {
3506 int ret = 0;
3507
3508 if (event->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3509 return 0;
3510 if (chan->channel_type == METADATA_CHANNEL)
3511 return 0;
3512
3513 lttng_metadata_begin(session);
3514
3515 ret = lttng_metadata_printf(session,
3516 "event {\n"
3517 " name = \"%s\";\n"
3518 " id = %u;\n"
3519 " stream_id = %u;\n",
3520 event->desc->name,
3521 event->id,
3522 event->chan->id);
3523 if (ret)
3524 goto end;
3525
3526 if (event->ctx) {
3527 ret = lttng_metadata_printf(session,
3528 " context := struct {\n");
3529 if (ret)
3530 goto end;
3531 }
3532 ret = _lttng_context_metadata_statedump(session, event->ctx);
3533 if (ret)
3534 goto end;
3535 if (event->ctx) {
3536 ret = lttng_metadata_printf(session,
3537 " };\n");
3538 if (ret)
3539 goto end;
3540 }
3541
3542 ret = lttng_metadata_printf(session,
3543 " fields := struct {\n"
3544 );
3545 if (ret)
3546 goto end;
3547
3548 ret = _lttng_fields_metadata_statedump(session, event);
3549 if (ret)
3550 goto end;
3551
3552 /*
3553 * LTTng space reservation can only reserve multiples of the
3554 * byte size.
3555 */
3556 ret = lttng_metadata_printf(session,
3557 " };\n"
3558 "};\n\n");
3559 if (ret)
3560 goto end;
3561
3562 event->metadata_dumped = 1;
3563 end:
3564 lttng_metadata_end(session);
3565 return ret;
3566
3567 }
3568
3569 /*
3570 * Must be called with sessions_mutex held.
3571 * The entire channel metadata is printed as a single atomic metadata
3572 * transaction.
3573 */
3574 static
3575 int _lttng_channel_metadata_statedump(struct lttng_session *session,
3576 struct lttng_channel *chan)
3577 {
3578 int ret = 0;
3579
3580 if (chan->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3581 return 0;
3582
3583 if (chan->channel_type == METADATA_CHANNEL)
3584 return 0;
3585
3586 lttng_metadata_begin(session);
3587
3588 WARN_ON_ONCE(!chan->header_type);
3589 ret = lttng_metadata_printf(session,
3590 "stream {\n"
3591 " id = %u;\n"
3592 " event.header := %s;\n"
3593 " packet.context := struct packet_context;\n",
3594 chan->id,
3595 chan->header_type == 1 ? "struct event_header_compact" :
3596 "struct event_header_large");
3597 if (ret)
3598 goto end;
3599
3600 if (chan->ctx) {
3601 ret = lttng_metadata_printf(session,
3602 " event.context := struct {\n");
3603 if (ret)
3604 goto end;
3605 }
3606 ret = _lttng_context_metadata_statedump(session, chan->ctx);
3607 if (ret)
3608 goto end;
3609 if (chan->ctx) {
3610 ret = lttng_metadata_printf(session,
3611 " };\n");
3612 if (ret)
3613 goto end;
3614 }
3615
3616 ret = lttng_metadata_printf(session,
3617 "};\n\n");
3618
3619 chan->metadata_dumped = 1;
3620 end:
3621 lttng_metadata_end(session);
3622 return ret;
3623 }
3624
3625 /*
3626 * Must be called with sessions_mutex held.
3627 */
3628 static
3629 int _lttng_stream_packet_context_declare(struct lttng_session *session)
3630 {
3631 return lttng_metadata_printf(session,
3632 "struct packet_context {\n"
3633 " uint64_clock_monotonic_t timestamp_begin;\n"
3634 " uint64_clock_monotonic_t timestamp_end;\n"
3635 " uint64_t content_size;\n"
3636 " uint64_t packet_size;\n"
3637 " uint64_t packet_seq_num;\n"
3638 " unsigned long events_discarded;\n"
3639 " uint32_t cpu_id;\n"
3640 "};\n\n"
3641 );
3642 }
3643
3644 /*
3645 * Compact header:
3646 * id: range: 0 - 30.
3647 * id 31 is reserved to indicate an extended header.
3648 *
3649 * Large header:
3650 * id: range: 0 - 65534.
3651 * id 65535 is reserved to indicate an extended header.
3652 *
3653 * Must be called with sessions_mutex held.
3654 */
3655 static
3656 int _lttng_event_header_declare(struct lttng_session *session)
3657 {
3658 return lttng_metadata_printf(session,
3659 "struct event_header_compact {\n"
3660 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3661 " variant <id> {\n"
3662 " struct {\n"
3663 " uint27_clock_monotonic_t timestamp;\n"
3664 " } compact;\n"
3665 " struct {\n"
3666 " uint32_t id;\n"
3667 " uint64_clock_monotonic_t timestamp;\n"
3668 " } extended;\n"
3669 " } v;\n"
3670 "} align(%u);\n"
3671 "\n"
3672 "struct event_header_large {\n"
3673 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3674 " variant <id> {\n"
3675 " struct {\n"
3676 " uint32_clock_monotonic_t timestamp;\n"
3677 " } compact;\n"
3678 " struct {\n"
3679 " uint32_t id;\n"
3680 " uint64_clock_monotonic_t timestamp;\n"
3681 " } extended;\n"
3682 " } v;\n"
3683 "} align(%u);\n\n",
3684 lttng_alignof(uint32_t) * CHAR_BIT,
3685 lttng_alignof(uint16_t) * CHAR_BIT
3686 );
3687 }
3688
3689 /*
3690 * Approximation of NTP time of day to clock monotonic correlation,
3691 * taken at start of trace.
3692 * Yes, this is only an approximation. Yes, we can (and will) do better
3693 * in future versions.
3694 * This function may return a negative offset. It may happen if the
3695 * system sets the REALTIME clock to 0 after boot.
3696 *
3697 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3698 * y2038 compliant.
3699 */
3700 static
3701 int64_t measure_clock_offset(void)
3702 {
3703 uint64_t monotonic_avg, monotonic[2], realtime;
3704 uint64_t tcf = trace_clock_freq();
3705 int64_t offset;
3706 unsigned long flags;
3707 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3708 struct timespec64 rts = { 0, 0 };
3709 #else
3710 struct timespec rts = { 0, 0 };
3711 #endif
3712
3713 /* Disable interrupts to increase correlation precision. */
3714 local_irq_save(flags);
3715 monotonic[0] = trace_clock_read64();
3716 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3717 ktime_get_real_ts64(&rts);
3718 #else
3719 getnstimeofday(&rts);
3720 #endif
3721 monotonic[1] = trace_clock_read64();
3722 local_irq_restore(flags);
3723
3724 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3725 realtime = (uint64_t) rts.tv_sec * tcf;
3726 if (tcf == NSEC_PER_SEC) {
3727 realtime += rts.tv_nsec;
3728 } else {
3729 uint64_t n = rts.tv_nsec * tcf;
3730
3731 do_div(n, NSEC_PER_SEC);
3732 realtime += n;
3733 }
3734 offset = (int64_t) realtime - monotonic_avg;
3735 return offset;
3736 }
3737
3738 static
3739 int print_escaped_ctf_string(struct lttng_session *session, const char *string)
3740 {
3741 int ret = 0;
3742 size_t i;
3743 char cur;
3744
3745 i = 0;
3746 cur = string[i];
3747 while (cur != '\0') {
3748 switch (cur) {
3749 case '\n':
3750 ret = lttng_metadata_printf(session, "%s", "\\n");
3751 break;
3752 case '\\':
3753 case '"':
3754 ret = lttng_metadata_printf(session, "%c", '\\');
3755 if (ret)
3756 goto error;
3757 /* We still print the current char */
3758 /* Fallthrough */
3759 default:
3760 ret = lttng_metadata_printf(session, "%c", cur);
3761 break;
3762 }
3763
3764 if (ret)
3765 goto error;
3766
3767 cur = string[++i];
3768 }
3769 error:
3770 return ret;
3771 }
3772
3773 static
3774 int print_metadata_escaped_field(struct lttng_session *session, const char *field,
3775 const char *field_value)
3776 {
3777 int ret;
3778
3779 ret = lttng_metadata_printf(session, " %s = \"", field);
3780 if (ret)
3781 goto error;
3782
3783 ret = print_escaped_ctf_string(session, field_value);
3784 if (ret)
3785 goto error;
3786
3787 ret = lttng_metadata_printf(session, "\";\n");
3788
3789 error:
3790 return ret;
3791 }
3792
3793 /*
3794 * Output metadata into this session's metadata buffers.
3795 * Must be called with sessions_mutex held.
3796 */
3797 static
3798 int _lttng_session_metadata_statedump(struct lttng_session *session)
3799 {
3800 unsigned char *uuid_c = session->uuid.b;
3801 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3802 const char *product_uuid;
3803 struct lttng_channel *chan;
3804 struct lttng_event *event;
3805 int ret = 0;
3806
3807 if (!LTTNG_READ_ONCE(session->active))
3808 return 0;
3809
3810 lttng_metadata_begin(session);
3811
3812 if (session->metadata_dumped)
3813 goto skip_session;
3814
3815 snprintf(uuid_s, sizeof(uuid_s),
3816 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3817 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3818 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3819 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3820 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3821
3822 ret = lttng_metadata_printf(session,
3823 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3824 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3825 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3826 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3827 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3828 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3829 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3830 "\n"
3831 "trace {\n"
3832 " major = %u;\n"
3833 " minor = %u;\n"
3834 " uuid = \"%s\";\n"
3835 " byte_order = %s;\n"
3836 " packet.header := struct {\n"
3837 " uint32_t magic;\n"
3838 " uint8_t uuid[16];\n"
3839 " uint32_t stream_id;\n"
3840 " uint64_t stream_instance_id;\n"
3841 " };\n"
3842 "};\n\n",
3843 lttng_alignof(uint8_t) * CHAR_BIT,
3844 lttng_alignof(uint16_t) * CHAR_BIT,
3845 lttng_alignof(uint32_t) * CHAR_BIT,
3846 lttng_alignof(uint64_t) * CHAR_BIT,
3847 sizeof(unsigned long) * CHAR_BIT,
3848 lttng_alignof(unsigned long) * CHAR_BIT,
3849 CTF_SPEC_MAJOR,
3850 CTF_SPEC_MINOR,
3851 uuid_s,
3852 #if __BYTE_ORDER == __BIG_ENDIAN
3853 "be"
3854 #else
3855 "le"
3856 #endif
3857 );
3858 if (ret)
3859 goto end;
3860
3861 ret = lttng_metadata_printf(session,
3862 "env {\n"
3863 " hostname = \"%s\";\n"
3864 " domain = \"kernel\";\n"
3865 " sysname = \"%s\";\n"
3866 " kernel_release = \"%s\";\n"
3867 " kernel_version = \"%s\";\n"
3868 " tracer_name = \"lttng-modules\";\n"
3869 " tracer_major = %d;\n"
3870 " tracer_minor = %d;\n"
3871 " tracer_patchlevel = %d;\n"
3872 " trace_buffering_scheme = \"global\";\n",
3873 current->nsproxy->uts_ns->name.nodename,
3874 utsname()->sysname,
3875 utsname()->release,
3876 utsname()->version,
3877 LTTNG_MODULES_MAJOR_VERSION,
3878 LTTNG_MODULES_MINOR_VERSION,
3879 LTTNG_MODULES_PATCHLEVEL_VERSION
3880 );
3881 if (ret)
3882 goto end;
3883
3884 ret = print_metadata_escaped_field(session, "trace_name", session->name);
3885 if (ret)
3886 goto end;
3887 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
3888 session->creation_time);
3889 if (ret)
3890 goto end;
3891
3892 /* Add the product UUID to the 'env' section */
3893 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
3894 if (product_uuid) {
3895 ret = lttng_metadata_printf(session,
3896 " product_uuid = \"%s\";\n",
3897 product_uuid
3898 );
3899 if (ret)
3900 goto end;
3901 }
3902
3903 /* Close the 'env' section */
3904 ret = lttng_metadata_printf(session, "};\n\n");
3905 if (ret)
3906 goto end;
3907
3908 ret = lttng_metadata_printf(session,
3909 "clock {\n"
3910 " name = \"%s\";\n",
3911 trace_clock_name()
3912 );
3913 if (ret)
3914 goto end;
3915
3916 if (!trace_clock_uuid(clock_uuid_s)) {
3917 ret = lttng_metadata_printf(session,
3918 " uuid = \"%s\";\n",
3919 clock_uuid_s
3920 );
3921 if (ret)
3922 goto end;
3923 }
3924
3925 ret = lttng_metadata_printf(session,
3926 " description = \"%s\";\n"
3927 " freq = %llu; /* Frequency, in Hz */\n"
3928 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
3929 " offset = %lld;\n"
3930 "};\n\n",
3931 trace_clock_description(),
3932 (unsigned long long) trace_clock_freq(),
3933 (long long) measure_clock_offset()
3934 );
3935 if (ret)
3936 goto end;
3937
3938 ret = lttng_metadata_printf(session,
3939 "typealias integer {\n"
3940 " size = 27; align = 1; signed = false;\n"
3941 " map = clock.%s.value;\n"
3942 "} := uint27_clock_monotonic_t;\n"
3943 "\n"
3944 "typealias integer {\n"
3945 " size = 32; align = %u; signed = false;\n"
3946 " map = clock.%s.value;\n"
3947 "} := uint32_clock_monotonic_t;\n"
3948 "\n"
3949 "typealias integer {\n"
3950 " size = 64; align = %u; signed = false;\n"
3951 " map = clock.%s.value;\n"
3952 "} := uint64_clock_monotonic_t;\n\n",
3953 trace_clock_name(),
3954 lttng_alignof(uint32_t) * CHAR_BIT,
3955 trace_clock_name(),
3956 lttng_alignof(uint64_t) * CHAR_BIT,
3957 trace_clock_name()
3958 );
3959 if (ret)
3960 goto end;
3961
3962 ret = _lttng_stream_packet_context_declare(session);
3963 if (ret)
3964 goto end;
3965
3966 ret = _lttng_event_header_declare(session);
3967 if (ret)
3968 goto end;
3969
3970 skip_session:
3971 list_for_each_entry(chan, &session->chan, list) {
3972 ret = _lttng_channel_metadata_statedump(session, chan);
3973 if (ret)
3974 goto end;
3975 }
3976
3977 list_for_each_entry(event, &session->events, list) {
3978 ret = _lttng_event_metadata_statedump(session, event->chan, event);
3979 if (ret)
3980 goto end;
3981 }
3982 session->metadata_dumped = 1;
3983 end:
3984 lttng_metadata_end(session);
3985 return ret;
3986 }
3987
3988 /**
3989 * lttng_transport_register - LTT transport registration
3990 * @transport: transport structure
3991 *
3992 * Registers a transport which can be used as output to extract the data out of
3993 * LTTng. The module calling this registration function must ensure that no
3994 * trap-inducing code will be executed by the transport functions. E.g.
3995 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
3996 * is made visible to the transport function. This registration acts as a
3997 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
3998 * after its registration must it synchronize the TLBs.
3999 */
4000 void lttng_transport_register(struct lttng_transport *transport)
4001 {
4002 /*
4003 * Make sure no page fault can be triggered by the module about to be
4004 * registered. We deal with this here so we don't have to call
4005 * vmalloc_sync_mappings() in each module's init.
4006 */
4007 wrapper_vmalloc_sync_mappings();
4008
4009 mutex_lock(&sessions_mutex);
4010 list_add_tail(&transport->node, &lttng_transport_list);
4011 mutex_unlock(&sessions_mutex);
4012 }
4013 EXPORT_SYMBOL_GPL(lttng_transport_register);
4014
4015 /**
4016 * lttng_transport_unregister - LTT transport unregistration
4017 * @transport: transport structure
4018 */
4019 void lttng_transport_unregister(struct lttng_transport *transport)
4020 {
4021 mutex_lock(&sessions_mutex);
4022 list_del(&transport->node);
4023 mutex_unlock(&sessions_mutex);
4024 }
4025 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4026
4027 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4028 {
4029 /*
4030 * Make sure no page fault can be triggered by the module about to be
4031 * registered. We deal with this here so we don't have to call
4032 * vmalloc_sync_mappings() in each module's init.
4033 */
4034 wrapper_vmalloc_sync_mappings();
4035
4036 mutex_lock(&sessions_mutex);
4037 list_add_tail(&transport->node, &lttng_counter_transport_list);
4038 mutex_unlock(&sessions_mutex);
4039 }
4040 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4041
4042 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4043 {
4044 mutex_lock(&sessions_mutex);
4045 list_del(&transport->node);
4046 mutex_unlock(&sessions_mutex);
4047 }
4048 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4049
4050 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4051
4052 enum cpuhp_state lttng_hp_prepare;
4053 enum cpuhp_state lttng_hp_online;
4054
4055 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4056 {
4057 struct lttng_cpuhp_node *lttng_node;
4058
4059 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4060 switch (lttng_node->component) {
4061 case LTTNG_RING_BUFFER_FRONTEND:
4062 return 0;
4063 case LTTNG_RING_BUFFER_BACKEND:
4064 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4065 case LTTNG_RING_BUFFER_ITER:
4066 return 0;
4067 case LTTNG_CONTEXT_PERF_COUNTERS:
4068 return 0;
4069 default:
4070 return -EINVAL;
4071 }
4072 }
4073
4074 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4075 {
4076 struct lttng_cpuhp_node *lttng_node;
4077
4078 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4079 switch (lttng_node->component) {
4080 case LTTNG_RING_BUFFER_FRONTEND:
4081 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4082 case LTTNG_RING_BUFFER_BACKEND:
4083 return 0;
4084 case LTTNG_RING_BUFFER_ITER:
4085 return 0;
4086 case LTTNG_CONTEXT_PERF_COUNTERS:
4087 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4088 default:
4089 return -EINVAL;
4090 }
4091 }
4092
4093 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4094 {
4095 struct lttng_cpuhp_node *lttng_node;
4096
4097 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4098 switch (lttng_node->component) {
4099 case LTTNG_RING_BUFFER_FRONTEND:
4100 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4101 case LTTNG_RING_BUFFER_BACKEND:
4102 return 0;
4103 case LTTNG_RING_BUFFER_ITER:
4104 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4105 case LTTNG_CONTEXT_PERF_COUNTERS:
4106 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4107 default:
4108 return -EINVAL;
4109 }
4110 }
4111
4112 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4113 {
4114 struct lttng_cpuhp_node *lttng_node;
4115
4116 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4117 switch (lttng_node->component) {
4118 case LTTNG_RING_BUFFER_FRONTEND:
4119 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4120 case LTTNG_RING_BUFFER_BACKEND:
4121 return 0;
4122 case LTTNG_RING_BUFFER_ITER:
4123 return 0;
4124 case LTTNG_CONTEXT_PERF_COUNTERS:
4125 return 0;
4126 default:
4127 return -EINVAL;
4128 }
4129 }
4130
4131 static int __init lttng_init_cpu_hotplug(void)
4132 {
4133 int ret;
4134
4135 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4136 lttng_hotplug_prepare,
4137 lttng_hotplug_dead);
4138 if (ret < 0) {
4139 return ret;
4140 }
4141 lttng_hp_prepare = ret;
4142 lttng_rb_set_hp_prepare(ret);
4143
4144 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4145 lttng_hotplug_online,
4146 lttng_hotplug_offline);
4147 if (ret < 0) {
4148 cpuhp_remove_multi_state(lttng_hp_prepare);
4149 lttng_hp_prepare = 0;
4150 return ret;
4151 }
4152 lttng_hp_online = ret;
4153 lttng_rb_set_hp_online(ret);
4154
4155 return 0;
4156 }
4157
4158 static void __exit lttng_exit_cpu_hotplug(void)
4159 {
4160 lttng_rb_set_hp_online(0);
4161 cpuhp_remove_multi_state(lttng_hp_online);
4162 lttng_rb_set_hp_prepare(0);
4163 cpuhp_remove_multi_state(lttng_hp_prepare);
4164 }
4165
4166 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4167 static int lttng_init_cpu_hotplug(void)
4168 {
4169 return 0;
4170 }
4171 static void lttng_exit_cpu_hotplug(void)
4172 {
4173 }
4174 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4175
4176
4177 static int __init lttng_events_init(void)
4178 {
4179 int ret;
4180
4181 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4182 if (ret)
4183 return ret;
4184 ret = wrapper_get_pfnblock_flags_mask_init();
4185 if (ret)
4186 return ret;
4187 ret = wrapper_get_pageblock_flags_mask_init();
4188 if (ret)
4189 return ret;
4190 ret = lttng_probes_init();
4191 if (ret)
4192 return ret;
4193 ret = lttng_context_init();
4194 if (ret)
4195 return ret;
4196 ret = lttng_tracepoint_init();
4197 if (ret)
4198 goto error_tp;
4199 event_cache = KMEM_CACHE(lttng_event, 0);
4200 if (!event_cache) {
4201 ret = -ENOMEM;
4202 goto error_kmem_event;
4203 }
4204 event_notifier_cache = KMEM_CACHE(lttng_event_notifier, 0);
4205 if (!event_notifier_cache) {
4206 ret = -ENOMEM;
4207 goto error_kmem_event_notifier;
4208 }
4209 ret = lttng_abi_init();
4210 if (ret)
4211 goto error_abi;
4212 ret = lttng_logger_init();
4213 if (ret)
4214 goto error_logger;
4215 ret = lttng_init_cpu_hotplug();
4216 if (ret)
4217 goto error_hotplug;
4218 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4219 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4220 __stringify(LTTNG_MODULES_MINOR_VERSION),
4221 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4222 LTTNG_MODULES_EXTRAVERSION,
4223 LTTNG_VERSION_NAME,
4224 #ifdef LTTNG_EXTRA_VERSION_GIT
4225 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4226 #else
4227 "",
4228 #endif
4229 #ifdef LTTNG_EXTRA_VERSION_NAME
4230 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4231 #else
4232 "");
4233 #endif
4234 return 0;
4235
4236 error_hotplug:
4237 lttng_logger_exit();
4238 error_logger:
4239 lttng_abi_exit();
4240 error_abi:
4241 kmem_cache_destroy(event_notifier_cache);
4242 error_kmem_event_notifier:
4243 kmem_cache_destroy(event_cache);
4244 error_kmem_event:
4245 lttng_tracepoint_exit();
4246 error_tp:
4247 lttng_context_exit();
4248 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4249 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4250 __stringify(LTTNG_MODULES_MINOR_VERSION),
4251 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4252 LTTNG_MODULES_EXTRAVERSION,
4253 LTTNG_VERSION_NAME,
4254 #ifdef LTTNG_EXTRA_VERSION_GIT
4255 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4256 #else
4257 "",
4258 #endif
4259 #ifdef LTTNG_EXTRA_VERSION_NAME
4260 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4261 #else
4262 "");
4263 #endif
4264 return ret;
4265 }
4266
4267 module_init(lttng_events_init);
4268
4269 static void __exit lttng_events_exit(void)
4270 {
4271 struct lttng_session *session, *tmpsession;
4272
4273 lttng_exit_cpu_hotplug();
4274 lttng_logger_exit();
4275 lttng_abi_exit();
4276 list_for_each_entry_safe(session, tmpsession, &sessions, list)
4277 lttng_session_destroy(session);
4278 kmem_cache_destroy(event_cache);
4279 kmem_cache_destroy(event_notifier_cache);
4280 lttng_tracepoint_exit();
4281 lttng_context_exit();
4282 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4283 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4284 __stringify(LTTNG_MODULES_MINOR_VERSION),
4285 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4286 LTTNG_MODULES_EXTRAVERSION,
4287 LTTNG_VERSION_NAME,
4288 #ifdef LTTNG_EXTRA_VERSION_GIT
4289 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4290 #else
4291 "",
4292 #endif
4293 #ifdef LTTNG_EXTRA_VERSION_NAME
4294 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4295 #else
4296 "");
4297 #endif
4298 }
4299
4300 module_exit(lttng_events_exit);
4301
4302 #include <generated/patches.h>
4303 #ifdef LTTNG_EXTRA_VERSION_GIT
4304 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4305 #endif
4306 #ifdef LTTNG_EXTRA_VERSION_NAME
4307 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4308 #endif
4309 MODULE_LICENSE("GPL and additional rights");
4310 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4311 MODULE_DESCRIPTION("LTTng tracer");
4312 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4313 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4314 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4315 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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